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Thursday, October 31, 2019
Carbon footprint Essay Example | Topics and Well Written Essays - 2000 words
Carbon footprint - Essay Example Other emissions from greenhouses such as Methane (CH4), Nitrous Oxide (N2O, Hydro fluorocarbons (HFCs), per fluorocarbons (PFCs), and Sulphur Hexafluoride (SF6) are all reported as carbon dioxide emissions. Reporting all the other greenhouse gas emissions (GHG) as a single value of measurement makes it easy to manage, calculate as well as reporting. While carbon dioxide emissions are primarily used as a method of calculating CO2e, there are efforts by the international coordination of standards and control to make sure that an approach that is consistent is adopted for purposes of usage as well as calculation of the value (Weidema 1995). It is worth noting that there are a set of rules referred to as GHG Protocol that are generally used as the basis of calculating carbon footprint. These protocols are in line with the propositions under the IPCC (Intergovernmental Panel on Climate Change) for national level calculation of carbon emission. Nevertheless, despite the existence of well-built international standards, there are no institutions to enforce such standards, and therefore some companies opt to design their own computation methods. The computations of carbon footprint consist of two key mechanisms which are indirect and direct emissions (McGregor & Vorley 2006). The purpose of this distinction is to enable easy calculation of a particular company or entry as well as to provide a suitable system that eliminates any possibilities of double accounting. It is worth mentioning the various reasons behind computation of carbon footprint, these reasons may include: To set up a true and fair account of carbon emission ( CO2e), the calculations also reduces and simplify the costs associated with carbon emission, in addition, it provides information that facilitates involvement in mandatory as well as voluntary carbon emission reduction programs, the calculation also helps in providing valuable information to the management that can be used to design an effective and viable approach to facilitate the implementation of a carbon management program in an organization (Brenton 2009). Discussion For purposes of computing carbon footprint, it is pertinent to ensure that there are established boundaries of computation. This is because the computation of carbon footprint can be visualized as having a number of boundaries that are different. These boundaries may include: Carbon footprint at the department level, Carbon footprint at the organizational level, Carbon footprint across the supply chain, and the LCA (full life-cycle assessment) on a service or product based model. This study will generally focus on product level carbon foot printing (Kasterine & Vanzetti 2010). As aforementioned, Product carbon foot printing approach is based on LCA (full life-cycle assessment). It is therefore pertinent to describe what is entailed under full life-cycle assessment (LCA) before attempting to understand what product carbon foot printing. LCA boundaries of evaluation broadly encompass the raw materials extraction and processing, manufacturing or production, consumer-use, as well as end-of-life scenarios; this may involve the process of material recycling (Hesselbach & Herrmann 2011). As such, the result obtained from a full life-cycle assessment can be used for purposes of identifying significant impacts on human health and environment emanating from a particular product, and such information can be used to alleviate the impact. The information gathered through LCA evaluation may also be useful in terms of designing an effective strategy that can reduce product cost while at the same time provi ding an opportunity to
Tuesday, October 29, 2019
Gay Marriages Essay Example for Free
Gay Marriages Essay When newer lifestyles creep into our society, inline with our thoughts and liberties, guardians of the older versions are likely to be taken back. These lifestyle changes happen in every sphere of life, like the way we eat or work. In getting along with it, we may have to abandon our traditional ways. Sometimes these may go unnoticed, as it may be beneficial to all, having none to worry about it. But other times the issues in question may be very important and fundamental, and there would be a social debate. Homosexuality and gay marriages is one such issue, which is still being debated widely. With homosexuality and gay marriages becoming increasingly present in our society, it is important that the subject be well debated and all issues projected so that it helps people to take appropriate decisions. The issue of homosexuality is not just relevant for the partners, but also to the families they are a part of, and to the society as a whole. It is therefore important that the society be well informed of the legal and social aspects of gay marriages, while being alive to the fact that evolving lifestyle issues could knock at anyone’s door. The media has a very important and responsible role in helping the larger part of the society to come to terms with evolving lifestyles.                This is perhaps what the film ‘The Wedding Banquet’ has attempted and succeeded. ‘The Wedding Banquet’ is a thoughtful and touching Chinese film revolving around homosexuality and family ties. The film brings into focus the perception of modern lifestyles, from the traditional point of view, and the difficulties and experiences involved in coming to terms with it (Don). The film projects homosexuality in a wider perspective. A gay relationship, in the midst of a heterosexual marriage and parenting, shows the wider realm of homosexuality and gay relationships. The film brings into focus a gay relationship between a Taiwanese expatriate Wai-Tung and his doctor boyfriend Simon. When Wai-Tung’s parents pressurize their son for his marriage, he plans to buy time by putting impossible conditions for his bride. However a dating company succeeds in finding a suitable match, when Wai-Tung strikes into a convenience marriage with his tenant Wei Wei. The marriage would help Wei Wei from being deported. It is when the parents of Wai-Tung reach America for the wedding banquet of their son, does they know of the developments in the family. The film has several turning points like when Wei Wei seduces an inebriated Wai-Tung and becomes pregnant, leading to deterioration in his relationship with Simon. Wai-Tung’s father approves of the actions of Simon, who he takes as his adopted son . His mother on the other hand is drawn affectionally to her daughter-in-law, whom his father considers as a business participant. At the end the father and mother leave for Taiwan, without any discontent. The movie definitely seems to address the issue of homosexuality in the family context. Bringing the issue of homosexuality face-to-face with traditionally heterosexual cultures, gets everyone on their toes to accept the reality. Lifestyle choices are here to stay and traditions must pave way to it and coexist. This low budget film won recognition for its director Ang Lee, who himself makes a short appearance as a banquet guest. It also won the Golden Bear award in the Berlin Film Festival of 1993 and the best film and best director awards at the 1993 Seattle International Film Festival (Berardinelli, 1993).                      The rights of homosexuals are increasingly gaining support with time. Homosexuals are being more welcome in our society and their rights are becoming more obvious. Gone are those days when homosexuality was considered a serious crime and homosexuals looked upon as people with sick minds. Although there are societies which still consider homosexuality a crime, it isn’t as dreadful as it once was. These developments indicate the growing perception that homosexuals are a part of our society and therefore should be accorded equal rights, equal protection and equal support from all welfare activities. The favorable trend towards homosexuals may be attributed to the general liberalization of policies in most parts of the world, broader thinking among people and the mixing of cultures and mingling of economics. But it is indeed sad that this never before support, is not extended to gay marriages. A major part of this support and backing, of homosexuality stops short of gay marriages. This indifference to gay marriage, particularly from among supporters of homosexuality stems from their perception of marriage and homosexuality. Gays are generally thought to have multiple partners and that therefore their relationships cannot be deep or emotional. The gays are considered as uncommitted and not being capable of forming lasting relationships. This description of gays cannot be challenged, as gays do have such relationships too. However, it should be noted here that such relationships also exist in heterosexual or straight society too, maybe to a small extent and that too mainly among the youth. What most people need to understand about gays is that, as gays grow and mature, they too like their straight counterparts begin to value and seek committed lasting relationships.                   It is important to realize the basics behind the emergence of homosexuality. Homosexuality is a naturally developing phenomenon. However, most ignorant people attribute it to a defiance of heterosexual norms and an intention to experiment. Some people feel that gays could choose being a heterosexual if they wanted, but that, only a very few consider that they have a choice. It is only like heterosexuals being asked to choose the sex they are attracted to. It should be understood that being a gay is natural and not selected. Several gay people, both men and women recall being attracted to people of their own sex from a very young age. The sexual orientation in most people emerge at a very early age like early adolescence, even prior to any sexual experience. Homosexual orientation is a complex subject and cannot be explained by any single or a simple, plain model. No consistent results have been found from research undertaken for homosexual orientation. Despite studying evolutionary and hormonal pattern in homosexuality, scientists have not yet understood the development of homosexual orientation in an individual. Therefore it is improper to assume that homosexuals have a choice, which they have chosen to bypass. Today however, most scientists agree that sexual orientation results from an influence of environment, cognitive and biological factors. Genetic and inborn hormonal traits play an important role in deciding a person’s sexual attitude. Psychologists and psychiatrists believe that homosexuality is not due to emotional or mental disorders; and it was in 1973, when the American Psychiatric Association removed homosexuality from its official list of emotional and mental disorders, after appropriate research (APA, 2008). Research based on twin studies also indicate that male homosexuality is genetically mediated. A study with about 76 gay brothers and their families in 1993 by Dean Hamer found that gay men had more gay uncles and cousins on the maternal side compared to the paternal side. One of the most reliable finding in homosexuality adoption was reported by Blanchard and Klassen in 1997, which suggested that the odds of an individual being a gay increased by 33% correpondingly for each older brother. It has been implied that the male foetus causes a maternal immune reaction which is increasingly stronger for each successive male foetus.                 Gay marriages are wrongly perceived by many people to alter family environment. The customary saying that marriage is an institution between a man and a woman holds no water, as there is no real and moral judgement behind it. Such definitions of marriages only raise questions on the eligibility and authenticity of the defining person or institution. Who should be the one to define marriage?. They feel that same-sex couples cannot provide the necessary environment for children’s normal growth. In continuation of this, many consider same-sex marriage as a deterrent to births and continuation of species. They don’t realise that marriages are not just directed to bearing children, as even infertile couples choose to marry or heterosexual couples sometimes choose against having children. Marriage is more about sharing, love and commitment and less about bearing children. It should be realized that gay couples are capable of raising children as much as any straight couple. The fact that there is no significant difference between the children of gay and straight couples, has been proved by research. Psychologists are of the opinion that the gender of the parent is not important in raising the child; it’s the love and commitment on the part of the parents that matter. As for the continuation of species, human species are in no danger of dwindling due to reproductive failure. In fact the population explosion is really disturbing and serious issues are at stake for the oncoming generations. Gay marriages can only help in slowing the rate of population increase, than adding to it. Gay marriages have seen results, since it has already been experimented. Denmark legalised gay marriages in 1989. Several Dutch cities have had same-sex marriage rights for many years. The clergy at first offered opposition to the Danish law and a survey conducted at that time indicated that about 72 percent of the clergy opposed the law. However another survey conducted in 1995 revealed that 89 percent of the clergy supported the law. Gay marriages have been experimented and proved to strengthen the institution of marriage and contribute to the society. Any doubts on the success of gay marriages are fully vacated and its positive impact on the society acknowledged.                     The interpretation of gay marriage in religion should not be ignored when considering gay marriages. Given the binding of religion and its influence on every aspect of life, people consider religious beliefs above all contemporary issues associated with gay marriages, when deciding on them. Some religions are against homosexuality and gay marriages while some do not consider it as something important to be preached upon. In the Old Testament only two passages are referred to homosexuality, among the several thousands (Piazza, 2007). Buddhism in fact attracts several homosexuals, as there isn’t any homophobia preaching in it. The Theravada Buddhism considers all relationships i.e.; gay, lesbian or straight as being personal matters bearing mutual consent (Robinson, 2008). Therefore all relationships are considered constructive and acceptable as long as both partners are happy. Many people, who believe in Christianity, oppose homosexuality and gay marriage, on the basis of the bible. It should primarily be noted here that the bible was written at a period when there was no understanding of homosexuality or psychosexual orientation. The bible therefore does not recognise people as lesbians or gays. The inference was only directed to homosexual acts committed by persons who were considered heterosexual. However, the bible has been successfully used to interpret the views of both advocates and opponents of homosexuality whenever homosexuality is deliberated. According to the Roman Catholic Church, any sex that does not lead to procreation should be avoided and thus the use of condoms and masturbation is condemned. However, it should also be noted that the church approves sex among sterile couples and sex during pregnancy, which do not lead to procreation (Corvino, 1997). An important aspect of bible interpretation is that, many Christians interpret all texts with much flexibility except when it comes to homosexuality, where  all references to homosexual acts are taken literally. The bible actually pays very little attention to this subject and most importantly Jesus speaks nothing on this topic, in the New Testament. This apart, most instructions and recommendations of the bible are of lesser relevance today, like avoiding pork. The teachings are subconsciously breached casually, as we go about our everyday lives. For instance, there was a prominent woman once spoke at length against homosexuality, in the course of which she broke several Biblical laws by Levitical standards (Piazza, 2007), namely speaking in church, she taught men and wore a cotton and polyester dress. The Bible interestingly has a few example of same sex love. David’s love for Jonathan was implied to be greater than his love for woman, Ruth’s deep love relationship with Naomi and Ruth’s words of pledge are used in most heterosexual weddings.                     Even though gay couples are now socially accepted like never before, they are far from equal civil rights. The withholding of civil rights to gay couples can sometimes be life ruining and even life threatening. The inconvenience and sufferings of gay couples as a consequence of these unequal rights can be endlessly said. In most American states, gay couples are not given the right to make medical decisions for their partners, during emergencies. State laws stipulate that the hospitals should reach out to the families of the hospitalised partner, thereby ignoring the gay partner’s concern. Very often, the families are not in good terms with the gay couple, and may even be without contact for a considerable long time. It is obvious that the decisions taken by such families would not be in the best interests of the couple. It is sad that the hostile family even have the right to exclude the partner from the treatment room. Even upon death, the will of the gay partner can be easily challenged and custody decisions overturned by the family (Bidstrup, 2004). Families have the right to deny the surviving partner, even a visit to his partner’s grave. There are several cases where gay couples had been extremely careful in drafting their will, which however were overturned, leaving the surviving partner literally penniless. Whenever arrested, gay couples are forced to provide evidence and testify against their partners. Most gay couples, particularly the older ones have numerous such stories of injustices meted out to their friends or acquaintances. The testimony of a gay partner is as irrelevant as the testimony of a complete stranger, in most courts. In case the partner is jailed, the right to visit the partner is denied in most cases. In matters of law, arrest or imprisonment, the whims of a hostile family and the cooperation of a homophobic judge can have devastating effects on the gay couple. The discrimination is pathetically extended even to the children of gay couples, as gay parents are not able to get parenting rights when children are brought into their family, either by birth or through adoption. These are some civil rights issues, which are in no way connected to the nature of marriages. State laws, which provide for the rights of legally married couples, are denied for gay couples.                   Gay couples are definitely not accorded equal rights, although the situation is improving and would one day catch up with those accorded to heterosexual couples. One must not forget that African-American marriages were not allowed, till the end of civil war. Until 1967, there were at least 15 states that prohibited interracial marriages. It required a US Supreme Court decision that year to ensure inter-racial marriages throughout the United States (Robinson). Same sex marriages are recent happenings, which were earlier not permitted anywhere in the world. The law is often the deciding factor in the fate of homosexuality like in November 2003 when the Massachusetts Supreme Judicial Court termed the ban on gay marriage as unconstitutional. Legislators have indeed played an important role in the acceptance of homosexuality and gay marriages. However there is a lot more for them to do. There are many states in the US, which have yet not legalized gay marriages. Apart from US, there are only a few countries that have recognized homosexual relationships. Social acceptance is a major struggle for homosexuality, which however can begin only after its legalization. Given the progress in acceptability of homosexuality till now, it is evident that all constitutions should and one day, would legalize homosexuality. It should be noted here that the European Union had demanded Turkey to form more liberal laws on sex, as a condition for its membership. Once homosexuality and gay marriages are legalized, the law should provide for the rights of gay couples, and for individual partners. Gay couples should be allowed to live peacefully like any other family, raise children and plan for their future. Homophobic attitudes should be better identified and punished when it attempts to hinder the rights of gay couples. Gay couples too have the responsibility to stand up against victimization rather than suffer alone in silence, fearing social stigma. It is rightly appropriate here to mention the fact that Brendan Fay had lodged a complaint against the Polish president for using his marriage images to warn his countrymen against gay marriages. Fay’s marriage to his partner Tom Moulton, and their marriage certificate was shown in his televised address to the nation. Fay said he considered it to be an insult and has complained to the Polish Consulate in New York (Salazar).                     The debate on providing equal rights to same-sex couples would go on. The public support for gay couples, would gradually translate to more support for marriage rights. However it is the law, which ultimately dictates on the right to gay marriages. The right of the individual to exercise his choice on his personal matters would ultimately be given to him, to enable him to select the gender of his partner. When South Africa’s highest court recognised same-sex marriages and decided to extend legal marital rights to gay couples, it became the first country to do so in a continent, which condemns homosexuality. It must be noteworthy to mention here that South Africa’s constitution is one of world’s most advanced and progressive constitutions. Constitutional reforms are important for any society to meet its trends and demands. Conservative societies should recognise and be willing to accept newer trends and passions. Just like racist discrimination was ruled out, a new dawn awaits the universal removal of discrimination to gay marriage; a dawn when all gay couples can live happily with all rights and liberties, without any fear or discrimination. â€Å"Although we cannot find that a fundamental right to same-sex marriage exists in this state, the unequal dispensation of rights and benefits to committed same-sex partners can no longer be tolerated under our state constitution,†said New Jersey Supreme Court Justice Barry T. Albin, while offering equal rights to same-sex couples.                  Education too has an important role to play in understanding homosexuality. Understanding the demands and options of today’s lifestyle, is very crucial for any individual, and one should have the relevant education to take appropriate decisions. Our traditional educational policies should be revamped with the realities of today. Educators must let people know to what extent the law currently permits one to select the gender of the person he or she wishes to marry. Educators must be prepared to transform individuals as responsible persons capable of loving, marrying and raising a family, irrespective of the gender of the partner he or she would be married to. Recognition of same sex relationships as being equal to traditional marriages would drastically redefine the meaning of family (Knight, 1997). Educational policy makers should realize that they hold a sacred duty of imparting education and social skills incorporating relevance to homosexual society too. As the legalization of homosexuality and gay marriages are slowly but steadily gaining ground, one thing is clear; these steps will always progress in the same direction. Therefore education must also keep up closely in the same direction for the welfare of its beneficiaries.                The legislators have a moral responsibility to provide and ensure proper implementation of the marriage rights of gay couples, as civil and partnership laws cannot provide the same benefits as that of marriage (Johnson, 2007). The educators have a responsibility of not only transforming the society to be receptive of gay marriages, but also ensuring that gay couples succeed in every aspect of life. The society as a whole should not only integrate gay couples into its fold, unconditionally, but also be fully prepared to welcome newer lifestyle changes of tomorrow.                                                  REFERENCES Don Willmott (2004) The Wedding Banquet [Electronic version]. Retrieved on March 19, 2008 from http://www.filmcritic.com/misc/emporium.nsf/reviews/The-Wedding-Banquet Berardinelli, James (1993) The Wedding Banquet [Electronic version]. Retrieved on March 19, 2008, from http://www.reelviews.net/movies/w/wedding_ban.html Salazar C. New York man files complaint against Polish president for anti-gay marriage speech. International Herald Tribune (19 Mar, 2008) [Electronic version] from http://www.iht.com/articles/ap/2008/03/19/europe/EU-GEN-Poland-Gay-Rights.php American Psychological Association. Sexuality [Electronic version]. Retrieved on March 19, 2008, from http://www.apa.org/topics/orientation.html#whatcauses  2008 Piazza M.S. Homosexuality and Christianity [Electronic version]. Retrieved on March 20, 2008, from http://www.cathedralofhope.com Robinson B.A, (2008). The Buddhist religion and homosexuality [Electronic version]. Retrieved on March 18, 2008, from http://www.religioustolerance.org/hom_budd.htm Corvino John. Why shouldn’t Tommy and Jim have sex? A defence of homosexuality. Same Sex: Debating the ethics, Science and Culture of Homosexuality, Rowman and Littlefield Publishers. (1997). Bidstrup Scott, (2004). Gay Marriage: The arguments and the motives [Electronic version]. Retrieved on March 18, 2008, from http://www.bidstrup.com/marriage.htm Knight Robert,. How domestic partnerships and Gay marriage threaten the family. Insight bulletin, Family Research Council. (1997) Johnson, Ramon. (2007) Gay marriage around the world. [Electronic version]. Retrieved on March 20, 2008, from http://gaylife.about.com/od/samesexmarriage/a/legalgaymarriag.htm
Sunday, October 27, 2019
Quantization effects in digital filters
Quantization effects in digital filters ABSTRACT: Quantization effects in digital filters can be divided into four main categories: quantization of system coefficients, errors due to A-D conversion, errors due to roundoffs in the arithmetic, and a constraint on signal level due to the requirement that overflow must be prevented in the comparison. The effects of quantization on implementations of two basic algorithms of digital filtering-the first-or second-order linear recursive difference equation, and the fast Fourier transform (FFT) are studied in some detail. For these algorithms, the differing quantization effects of fixed point, floating point, and block floating point arithmetic are examined and compared. The ideas developed in the study of simple recursive filters and the FFT are applied to analyze the effects of coefficient quantization, roundoff noise, and the overflow constraint in two more complicated types of digital filters frequency sampling and FFT filters. Realizations of the same filter design, by means of the frequency sampling and FFT methods, are compared on the basis of differing quantization effects. All the noise analyses in the report are based on simple statistical models for roundoff and A-D conversion errors. Experimental noise measurements testing the predictions of these models are reported, and the empirical results are generally in good agreement with the statistical predictions INTRODUCTION: Digital filters are widely used in modern signal-transmission systems. The first-order filters are used for extracting lower-frequency or upper-frequency signals. Quantization errors due to the finite number of binary digits in the representation of numbers are typical of digital filters. Quantization is a representation of data samples with a certain number of bits per sample after rounding to a suitable level of precision. Quantization errors in a Digital Signal Processing (DSP) system can be introduced from three sources; one source is input quantization, a second is coefficient quantization and the third is the finite precision in the arithmetic operations. The quantization error in the arithmetic operations can be controlled by carefully selecting the size of buffer registers according to the input word length. Quantization errors from input and filter samples are considered in this article. The effects of quantization errors and the tradeoffs required between precision and hardware resources are discussed in relation to the implementation of the DSP in Field Programmable Gate Array (FPGA). This article is divided into three main sections; quantization effects for upconversion, quantization noise due to rounding off arithmetic and quantization effects for digital beamforming (DBF). Fixed length samples cause reduction in the filter dynamic range and gain resolution. Quantization In digital signal processing, quantization is the process of approximating (mapping) a continuous range of values (or a very large set of possible discrete values) by a relatively small (finite) set of (values which can still take on continuous range) discrete symbols or integer values. For example, rounding a real number in the interval [0,100] to an integer 0,1,2,100. In other words, quantization can be described as a mapping that represents a finite continuous interval I = [a,b] of the range of a continuous valued signal, with a single number c, which is also on that interval. For example, rounding to the nearest integer (rounding  ½ up) replaces the interval [c .5,c + .5) with the number c, for integer c. After that quantization we produce a finite set of values which can be encoded by say binary techniques. A. QUANTIZATION EFFECTS ON UPCONVERSION: In multirate systems, upconvcersion can be achieved with oversampling and filtering techniques. For the proposed digital TIGER system, input Gaussian pulses are upsampled to produce higher order Nyquist zones. A high pass FIR filter is employed to acquire a spectral zone at the expanded band edge. In this case, higher efficiency is possible by exploiting filter symmetry. For a higher throughput rate, polyphase implementation of the FIR filters can be employed. Since signal amplification is performed in the analog domain, a high speed 14 bit DAC is used for digital to analog conversion. Finite precision causes similar effects in the input data samples and filter coefficients. Fixed word length effects on filter coefficients, filter length and dynamic range are described in the following sections. 1. Sensitivity of Filter Coefficients to Quantization Finite precision plays a significant role in the dynamic range of filter gain and DC offset. A large number of quantization levels will decrease the quantization error; on the other hand it requires larger silicon space to implement the design. The quantization affects the input Gaussian pulse and the filter coefficients. The pole and zero maps show perturbations in Figure 1 when samples are restricted to finite word length. The filter coefficients in the lower parts are constrained to 14 bit quantized samples and the length of the filter is 100 taps. This constraint arises from the fast DAC of 14 bit width used for converting a digital signal into the analog domain. Since the dynamic range of the quantizer is less than that of the filter coefficients, the quantized coefficients are disturbed from the unit circle. The gain of the quantized filter response is displayed in Figure 1 which is distinctly less than that for the infinite precision filter. For these simulations infinite prec ision representation is regarded as floating point, which provides significantly better precision than the quantization levels discussed here. The zeros around Z = -1 are responsible for passband attenuation and are less displaced. As the dynamic range of the quantizer is increased to match the filter coefficients, the signal to quantization noise ratio (SNR) improves, but at the cost of increased hardware resources. Similar results can be obtained for the input Gaussian pulse when quantized to specified fourteen bit word lengths. Finite precision is hardware efficient since the system data width is less than the infinite precision (or floating point) case. Quantization reduces a few out of 100 coefficients to zero, which will further ameliorate the memory cell and arithmetic processing requirement. Quantization also reduces the filter gain compared to infinite precision samples; however this reduction is acceptable as long as it remains within an attenuation limit. The fourteen bit quantizer provides more than 80dB attenuation which is better than the standard of 60dB used by many communication systems. 2. Quantization Effects on Filter Order For direct conversion transmission, a cascaded design performs better than a single stage. This is because quantization errors are reduced with a lower filter order. Secondly a lower order design requires less logic resources. Quantization errors vary with the length of a filter and we now study the effects of the filter order on the quantization error. A simulated result is shown in Figure 2, where quantization error is plotted against variable filter order. The quantization is performed by rounding the infinite precision samples to the closest fixed point value. The quantization error increases with increased filter order, since the highest power index in the filter polynomial is the most affected by the rounding. When the quantizer is increased with one more bit in the precision, the error is reduced by approximately 6dB as would be expected. The lower order filter provides better dynamic range than the higher order for eight and nine bit quantizers. This fact is also evident in Figure 2. At lower filter order of fifty, accumulative quantization error is around -43dB and at higher order of 200, it is -31dB. The 12dB difference is equivalent to two additional bits in quantization. Non-linear effects of the quantization can be reduced using a smaller filter order in the modulator. Since the cascaded design comprises a filter of lower order, compared with the single model, it introduces less quantization error than the single stage. 3. Quantization and Word length The dynamic range of the scaled filter depends on the number of bits assigned to the quantizer. For maximum signal power, the quantizer range should be equal to the signal magnitude. An FIR filter with filter variance 2 f s and quantization noise variance 2 n s has a signal to noise ratio of This expression can be used to estimate the appropriate word length for the FPGA implementation. A comparison of SNR versus word precision using the above expression has been calculated and is shown in Figure 3. From this graph it is evident that for each bit added to the word length, there is approximately a six decibel improvement in the SNR. For a higher precision level, a system can still be implemented, but at the cost of increased FPGA logic resources. B. QUANTIZATION NOISE DUE TO ROUNDING OF ARITHMETIC: In the poly phase filter, like in any other filter, quantization has to be performed on the result of any arithmetic operation. This is because any such operation requires more bits to represent the result than is required for each of the operands. If the Word length were always to be adjusted to store the data in full precision, this would be impractical, as there would soon be too many bits required to be stored in the available memory. Therefore, the word length of the internal data, has to be chosen, and the result of any arithmetic operation has to be constrained back to using the quantization scheme chosen from the ones shown in the previous section, as appropriate for the given application. The quantization operation may cause a disturbance to the result of the arithmetic operation. For normal filtering operations, such a quantization disturbance can usually be successfully considered as white noise and modeled as an additive noise source at the point of the arithmetic operation with the quantization step equal to the LSB of the internal data, . This certainly is not the case for zero-valued or constant input signals. However, modeling the quantization has-in most cases-the purpose of determining the maximum noise disturbance in the system. Hence, even if the additive quantization noise model gives overestimated values of the noise for very specific signals, this fact does not decrease the usefulness of the approach. After the shape of the quantization noise power spectral density (NPSD) is found, it can be used to identify regions that might cause overloading or loss of precision due to arithmetic noise shaping; also the required input signal scaling and the required internal arithmetic word length can be estimated for a given noise performance. The standard methods of estimating the maximum signal level at a given node are L1-norm (modulus of the impulse response-worst-case scenario), L2-norm (statistical mean-square), and L -norm (peak in frequency domain giving the effect of the input spectral shaping). These norms can be easily estimated for the given node from the shape of the NPSD. The quantization noise injected at each adder and multiplier, originally spectrally flat, is shaped by the noise shaping function (NSF), , calculated from the output of the filter to the input of each of the noise sources, i.e., to the output of each of the arithmetic operators. These functions were calculated for all of the all pass filter structures are shown in Fig. 2. The shapes of the nontrivial of the NFS are shown in Fig. 3. The accumulated quantization NPSD transferred to the output, , is obtained by shaping the uniform NPSD from each of the quantization noise sources by the square of the magnitude of the NFS corresponding to the given noise injection point and can be described by The results show that all structures perform in a way very distinct from the other ones. Structure (a)has the best performance at dc, half-Nyquist , and Nyquist , where the NPSD falls toward minus infinity. Its two maxima are symmetric about and independent of the coefficient value. The peaks are distant from for small coefficient values and approaches it as the coefficient increases. Structure (b) has uniform noise spectral distribution as all the arithmetic operations are either at the filter input-then noise is shaped by the allpass characteristic of the whole filter-or at its output. Structure (d) also has a minimum at v=0.25 . Its average noise power level decreases as the value of the all pass coefficient increases. Structure (c), the best from the point of view of the required guard bits, has its maximum at v=0.25 going toward infinity for coefficient values approaching one. This effect is a result of the denominator of the Nth-order all pass filter causing the poles of the filter to move toward the unit circle at normalized frequencies of v=2pik/N,k=0.N-1 for the coefficient approaching one. If there is no counter effect of the numerator, like for the case of P1(Z) for structure (c) and for structure (a), then the function goes to infinity. Even though structure (c) goes to infinity at v=0.25 for alfa=1, it has the lowest average noise power from all the structures. This structure has a big advantage in terms of the number of required guard bits and ease of cascading a number of them into higher order all pass filters. If the filter coefficients appro ach one, then the increase in quantization noise power could be countered with few additional bits. Using other structures would only replace the problem of dealing with an increase in the quantization noise with the problem of having to increase the number of guard bits required to deal with an increase of the peak gains. The NPSD of the quantization noise at the output of the poly phase structure can be calculated as the sum of the NPSD at the output of all all pass filters in the filter scaled by the 1/N factor N, being the number of paths. If the filter is cascaded with another filter, the NPSD of the first one will also be shaped by the square of the magnitude of the second filter. sources. The intention was to check the correctness of the theoretical equations by applying the white noise sources instead of quantization and by performing the quantization after addition and multiplication (rounding and truncating) to verify the shaping of the quantization noise and its level both for white input noise sources and real-life signals. The shape of the output quantization noise accumulated from all arithmetic elements for a wide-band input signal assuming, for simplicity, no correlation between the noise sources, is shown for all considered all pass structures in Fig. 4. The solid curve indicates the theoretical NSF that is very well matching the median of the quantization noise (curves lying on top of each other). The quantization noise power increase calculated for the given coefficient was 8.5 dB for structure (a), 6 dB for structure (c), 7.3 dB for structure (d), and 9 dB for structure (b). It is clear that the quantization noise differs from the assumed white n oise characteristic. However, the approximation still holds with an accuracy of around 5-10% depending on the structure of the input signal. An example of more accurate modeling of the quantization noise caused by arithmetic operations can be found in (a). The arithmetic quantization noise certainly decreases the accuracy of the filter output. The value of the arithmetic word length has to be chosen such that the quantization noise power is smaller than the stop band attenuation of the filter and the stop band ripples. In certain cases, the design requirements have to be made more stringent to allow some unavoidable distortion due to the arithmetic word length effects. For the case of decimation filters for the based A/D converters, the quantization noise adds to the one originating from the modulator. In such a case, each stage of the decimator has to be designed so that it filters out this noise as well. The verification of the peak gain analysis was performed by applying single-tone signals at the characteristic frequencies- where functions from Fig. 2 have their extremes-and by using wideband signals to make sure that the estimates are accurate. The experimental results confirmed the theoretical calculations. The results of the simulation for the white noise input signal of unity power are given in Fig. 8. The simulation was performed for a white noise input signal of unity power in order to have a uniform gain analysis across the whole range of frequencies. The theoretical shape of the gain is shown by a solid line that is very closely matching the median value of the signal at the test points. C. QUANTIZATION EFFECTS ON DIGITAL BEAMFORMING: The quantization of infinite precision samples into fixed word length degrades the phased signals. As was discussed in the previous section, the use of more levels for higher precision decreases the quantization error at the expense of larger hardware resources. For a reduced precision level, quantization error is spread to the main beams and to the grating lobes as well. In this section we present effects of quantization on beam resolution and associated grating lobes. 1. Quantization effects on Beam Pattern Phased signals have similar quantized effects on main beam resolution as the filter samples. However non-linearity arises in the sidelobes since the quantizer is not of adequate resolution to represent small changes that affect the sidelobe levels. In order to investigate the quantization effects, an example is presented with fixed word length delay samples. The coefficients of the time vector are quantized into four and ten bits; the increased number of bits will reduce the quantization effect. For an actual design the fixed bit width will depend on available hardware resources. The quantized beam in Figure 1 shows that a four bit fixed number does not adequately represent the beam pattern and thus introduces quantization noise. The ten bit numbers will also introduce quantization error, but at a lower level as shown in Figure 1(b). As can be seen from this simple example, the four bit quantization compromises the sidelobes at the 20dB level, while the ten bit quantization provides a reasonably faithful reconstruction of the theoretical sidelobes at this level. Therefore we conclude that for the 14 bit DAC of the proposed system, the sidelobe level will be essentially unaffected by the quantization at the -20dB level. 2. Sensitivity of Sidelobe Levels to Quantization Quantization causes gain errors in sidelobe levels. Higher resolution in quantization introduces lower quantization error. The graph in Figure 1 shows that the four bit samples result in a quantization error which reduces the first sidelobe gain while producing a gain error in the second sidelobe. The quantization error changes the dynamic range of the grating lobes and degrades the adjacent beam resolution for multiple beam systems. A simulated graph is displayed in Figure 2 to demonstrate non-linear behavior of the quantizer in the sidelobe resolution. For a lower order quantizer, the quantization step is not perfectly matched with the sidelobe levels. For the first sidelobe, the quantized resolution is less than the infinite precision case, although it approaches the floating point value with increasing quantized levels. Figure 2(a) shows that for a three bit quantizer, the first sidelobe resolution is at -18dB, while at ten bits it approaches the infinite precision value of -13.5dB. Unlike the first sidelobe, the second sidelobe exhibits higher resolution error at a lower precision level, since the quantizer can not represent the dynamic range adequately. Again, quantization error reduces with an increase in the number of bits. CONCLUSION: In this paper, effect of fixed word lengths on signal upconversion, quantization noise due to round of arithmetic and quantization effects on digital beam forming have been discussed. For the digital up conversion process, the quantization error can be described using pole/zero filter and frequency response plots. Filter resolution and stop band attenuation are degraded when quantization is introduced. For an increase in filter order, the quantization error increases as the highest order in filter polynomial is effected the most. To overcome this limitation, the number of precision levels of a quantizer can be increased, however this will require increased logic resources for FPGA implementation. Quantization effects in phasing are more complex than in the filter quantization since finite precision degrades the side lobe resolution. For lower precision levels, the quantization error exhibits non-linear behavior in the second side lobe. The quantization error is higher for lower precision levels. In order to overcome these non-linear effects, a precision level of more than eight bits is required. Performance of the proposed digital system will be effectively unaffected by the fixed word length limitations since a system data bus of at least 14 bits is suggested. REFERENCES: A. B. Sripad and D. L. Snyder, A Necessary and Sufficient Condition for Quantization Errors to be Uniform and White P. P. Vaidyanathan, On coefficient-quantization and computational roundoff effects in lossless multirate filter banks. 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Friday, October 25, 2019
themes in lost horizon Essay -- essays research papers
What is Paradise? Throughout history man has sought to create, find, or at least image a paradise on earth, a place where there is peace, harmony, and a surcease from the pain that plagues our lives. On the eve of World War II, James Hilton imagined such a place in his best-selling novel, Lost Horizon. The story itself begins when an evacuation of Westerners is ordered in the midst of revolution in Baksul, India. A plane containing four passengers is hi-jacked and flown far away into the Keun-Lun Mountains of Tibet. The plane crashes and the passengers are welcomed to the valley of the Blue Moon, and the lamasery of Shangri-la. Here they see an isolated monastery shrouded in mystery, which combines Christianity and Buddhism with a focus on the progression of knowledge. The four passengers who land in Shangri-la are Barnard, a boisterous American, Miss Brinklow, a Christian missionary, Mallinson, a headstrong and passionate English youth, and Conway, the main character and WWI veteran who is unattached and somewhat passionless. All of the characters except Mallinson enjoy life in Shangri-la. Conway especially finds himself at home there and eventually the High Lama of the lamasery unveils all its mysteries of to him. Conway learns that the inhabitants, thanks to the climate and a special drug, live to an extreme old age. They devote the length of their lives to the pursuits of knowledge and do everything in moderation. They believe that their hidden society will escape the...
Thursday, October 24, 2019
Notes: Meaning of Life and Distinguished Indian Writer
R. K. Narayan (1906-2001) is one of the most famous and distinguished Indian writer in English. He had a fine insight into various aspects on the lives of the poor and the middle class people, particularly in South India. He makes the dull and common place events more interesting and this essay is one such essay. In a writing career that spanned over sixty years, Narayan received many awards and honours. His writings are full of humour. In this essay he explains the advantages of headache.A blessing for Mankind: R. K. Narayan explains how headache conferred on mankind as a blessing by a benign providence and also talks about the usefulness of headache to avoid difficult situations. He later narrates an incident in his school life about the letter writing exercise, where his teacher used headache as a cause in the specimen letter. He always wondered what made his teacher to select for headache as a cause even in a specimen letter.Later he talks about the drill class during his school days and how students usually mentioned ‘headache’ as an excuse for avoiding the drill class after the school hours. One day the instructor asked all the students suffering from headache to hold their arms. For many students it raised large hope. The instructor also added that he was going to give them some special exercise to cure their splitting headache. Not even a boy raised his arms. Thus the instructor put an end to that problem. Touch of Importance:Headache gives the sufferer a touch of importance because it can be mentioned in any social gathering and is well taken. No other pain can be so openly mentioned with freedom from punishment. Other aches sound crude and bad which cannot be mentioned in publish and thus headache helps us to avoid many embarrassing situation. What is indisposition? Indisposition is a superior expression; it can be used only by eminent people. R. K. Narayan was really concerned about finding the real meaning of the word indisposition sinc e it is very vague and confusing.He feels that he was not able to understand the meaning of the word indisposition except that it sounds very well in press notes or health bulletins or in messages from eminent men to gatherings to which they have been invited. It cannot be written directly and it will sound better in the third person. A gentlemen is an eminent one, has a secretary or a deputy who can speak for him. For example a gentleman regrets his inability to attend the meeting today owing to indisposition (sickness or unwillingness).People will understand and accept the statement and will not question the concerned person. R. K. Narayan wants to know the perfect meaning of indisposition. Is the concerned person down with flu or malaria or cold or rheumatism (pain in joints and muscles)? He feels that the word indisposition could be used only at a particular level, not by all and if a school boy says â€Å"As I am indisposed, I want to be let off†, he will have his ears t wisted for his intelligence beyond his age. Headache as an excuse:If we openly say that we want to avoid the situation or an important meeting, people will get angry. No one has really got courage to tell that he/she is not willing to attend a meeting or a social gathering. The world is not yet ripe for such outspokenness and frankness. So we safely use headache as an excuse. At home, headache is used as an excuse to avoid many uncomfortable situations. The mother-in-law, who is angry with the daughter-in-law, uses it to avoid food. The son, who does not want to take his wife out, gives headache as an excuse.The boy, who has skipped his homework, claims headache in order to avoid his tutor and to send him back away. The cultured existence is not to interfere too deeply, but to accept the face value as expressed by the speaker. Conclusion: Headache has become a confirmed habit. Lots of medicines have been produced to cure headache, which people always carry with them and feels uneasy without them. Opticians give glasses to cure and relieve headache. All these things prove that mankind easily begins to believe in myths.
Wednesday, October 23, 2019
Greek Independence
For centuries the Greek population was completely under the Ottoman rule. The Greeks’ independence from the Ottoman Turks in 1830 did not come without hardship and suffering. Several other countries including Russia and France took sides with Greece during this fight as they felt close and connected with their culture. A nine year war was fought which eventually resulted in the Greeks gaining independence from the Turks. During this time, the Greeks had to maintain high morale and a strong disposition to be as successful as they were in the end. The circumstances they were under were difficult and harsh. Many people felt as though Greece deserved to break away from the Ottoman Empire, but some believed that the Turkish rule was not too oppressing. Most people believed that the people of Greece had great character and deserved to be free from the brutality of the Ottoman Turks. They were seen as having strong will to be independent and worked together as a country to achieve that goal. Their culture still to this day is being represented in different forms of art, for example architecture. It’s been studied for years because it served as a foundation for several other countries and is being kept alive, as opposed to forgotten. One poet, Alexandros Kalphoglou, described the Greeks as being enlightened, educated, well-rounded people. He went on to say that they were very open to and accepting of other cultures. It’s not surprising that Kalphoglou would’ve felt this way because he was a Greek Christian and most likely would be proud of his own history (Doc 4). Similarly, Percy Shelley was also a poet who believed Greek culture was essential for all other cultures to grow. She, however, was an English romantic poet. It’d be expected for her to praise Greece because romantic poets were all for the Greek revolution and independence (Doc 7). These two weren’t the only people who shared the same point of view on the Greek Revolt. While still under the Ottoman rule, Greek citizens were treated unfairly and poorly. Their living conditions were unstable and were constantly in upheaval due to the massive rebellion. The entire revolution was sparked by the lack of support shown by the Turkish rulers toward the Greeks. The bright, upbeat, and beautiful presence of the Greek culture was robbed by the Turks according to Savary, a French scholar of Greek. As a person who most likely spent a majority of the time studying Greek history, he would be inclined to respect their culture (Doc 3). Sneyd Davis, an English writer, spoke of Athens being deteriorated and everything beautiful that once existed there, vanishing. The events of what happened to the Greeks under the Ottomans can be easily related to this poem because their pride in their past was diminished. Davis is another romantic poet so I would expect to see him pro-Greek revolution (Doc 1). A majority of people were pleased with the fact that Greece did gain its independence from the Ottoman Turkish Empire. They believed that Greeks should have their arts, language, and other forms of culture restored fully so that they could regain pride in themselves. People also thought that Greek revolution would result in more successful nations in the future, which would be based on Greek tradition. A pamphlet called Greek exiles described the rise of Greek ancestors as heroes in history. It talks about how the Ottomans may have once been at power, but years later they didn’t stand a chance against the Greeks (Doc 6). In regards to Mavrocordato, it was a strong act of courage for the Greeks to take their independence and basically create their own government starting with nothing. Basically, he says that they wanted and made peace for themselves, but worked hard to get to that point (Doc 10). In an engraving created in 1828, called Greece Sacrificed, Regnier has depicted a scene where the Turks are attacking the Greeks, but not very successfully due to the fact that the Greeks are holding their ground. They’re standing for what they believe in as strong-minded individuals with a common goal in mind (Doc 11). Although most would agree that the Greek revolution was a positive thing, there are some people that are on the complete opposite side of things. These people think that the Turkish reign was not too overbearing, and that the Greeks could’ve easily stayed under their control. A Turkish sultan named Mustapha III, in 1765 made orders very clear to the governor of northern Greece to try and stop the revolts being made by the Greeks. He went on to describe the problems that the Greek population had been causing such as robberies. He thought that the Greek revolution had caused more problems than it solved, and that it should’ve been stopped early. Because of the fact that he was a sultan of the Ottoman Empire I find it almost obvious that he was against the Greeks in their revolts. Mustapha wanted what was best for his nation and people (Doc 2). In Vahid’s opinion, a Turkish governor, the revolution of the Greeks was driven by what he calls ‘drunkards,’ meaning that he didn’t take the rebellions seriously. Again, being of Turkish government, he would favor the Ottoman side of things (Doc 9). During the eighteenth and nineteenth centuries Greece was driven to rebel against their previous rulers the Ottoman Turks. Their culture and everything they took pride in was meaningless in the Turks’ eyes. They felt they had to start a revolution to gain back the rights they deserved. During this revolt, they living conditions were not as good as they could’ve been. In fact they were difficult to deal with, but this had only been a small hurdle for the Greek population who was determined to gain independence. Nothing could stand in their way, as they were a fearless, courageous nation. Finally, after suffering through nine years of antagonizing war and treachery, the Greeks gained their independence from the Ottoman Turks and started to create a government as a unified country.
Tuesday, October 22, 2019
George knew Lennie from his Aunt Clara Essays
George knew Lennie from his Aunt Clara Essays George knew Lennie from his Aunt Clara Paper George knew Lennie from his Aunt Clara Paper the sun behind them casting a shadow over the southern landscape. Slightly east of a ranch located in weed where their were hard labourers at work was a magical looking pool, and a king of crystal reflection, a gleaming whiteness shining on the shrubs that lay across it. There was a calming breeze against the dry old trees brushing the crisp feather like leaves flying like tumbleweed in the wind. A winding road lead of the lush colour of orchards, orange trees, vineyards, peaches and apricots. To the right of the road stood tall a giant orange tree with wild rabbits springing up and down around it, a truly beautiful sight, the vibrant colour in the distance waking you up making you want to run out and meet it. A local ranch in northern California, north of San Francisco called Weed was the next monotonous stop for George Milton and Lennie Small, these companions were very much the most unlikely pair of characters you could ever come across, George wore simple jeans a dirty old short sleeved shirt and a jacket unbuttoned as always, he was a prominent character, a strong willed and confident man who took control of any situation and never got in trouble, although his size never reflected his social ability and prowess only being a short guy, he was a strong minded individual with a positive attitude to life but was stuck at square one in life working as a ranch worker. : Lennie is the quite opposite of George , Lennie is a slow character who travelled with George and was his working buddy, he relied on George for almost everything, it takes a long time before you can get things into Lennies head, hes a large man as strong as a bull, much bigger than the average man and 5 times as strong, most of the time Lennie didnt realise how strong he really is. Lennie was as gentle as a butterfly and a kind man who never means any harm to anybody, Lennie loves animals, especially rabbits, he often asks George to tell him about his favourite dream about living off the fatta lan with Lennie tending the rabbits and making a living with their own crops and enjoying life, Lennie loved this story and saw it as his dream and George always told him it because it gave Lennie a buzz and a kick. Lennie and George were born in Auborn, George knew Lennie from his Aunt Clara, who took Lennie when he was a baby and raised him, but unfortunately she died and George took him under his wing and took him to work the ranches with him, they got used to each other and after a while they grew good friends. Lennie and George work at the desert countryside ranch of weed, working as skinners, grain bag rustlers, cultivator drivers and crop scithers. They both ended up in Weed because it was their next working stop, they had just come from the Shasta ranch which lay east about 30 miles away from Weed, they couldnt wait to get out of Shasta, they had been miserable there because the weather had been grey and dismal for their whole two week stay and people didnt find a liking to them well. Lennie and George were both eager to work at Weed because Lennie had gotten George in trouble with the boss back at Shasta for the simple reason that Lennie was too shy to talk to the man because he didnt look nice and had a mean look on his face. They arrived in Weed and they stayed in a very old ranch house filled with rugged wooden furniture and simple one cover beds. George dropped his bags down off his shoulders and turned and looked at Lennie and said, Well Lennie here we are again. Lennie glared at George, Wha what do you mean George I mean were back at another stupid ranch doing the same old stupid job. George said with a sigh. Lennie and George were arranging their things when a man walked in, he was a tall standing Negro with broad shoulders and cut arms, he came in to see the new boys, he said his name was Jackson , he was explaining the life on the ranch to Lennie and George, mostly about how unhappy life is for him at the ranch because no one speaks to him, Jackson took a liking in these two straight away, he talked to them for a while mostly bragging about how hard he works, George was quick to jump in and say, lennie sure is a hard worker too, jus give im a pack o sacks and he move them all day. Jackson looked at Lennie up and down and didnt feel intimidated, he stared at Lennie in the eyes longingly, Lennie caught contact with Jackson and immediately Lennie looked to the floor, Jackson laughed and made his way to the door, the sun pierced into the room like a red carpet, Jackson stopped holding the door open and said, There she is. Theres who?
Sunday, October 20, 2019
Thailand in the 15th-18th cent essays
Thailand in the 15th-18th cent essays Thailand has historically been a strong, proud nation. The people of Thailand have never gone hungry due to their vast food sources. Their military proved to be one of the best in the area. The country was set in a great location, allowing large ports for international trade and large agricultural areas on the interior. Thailand was a vast nation that went through rough times, but always seemed to pull themselves up. At the end of the 14th century Ayutthaya was the strongest power in South East Asia, although it lacked the manpower necessary to dominate the region. The armies repeatedly tried to sack Angkor, but were constantly extinguished. Thai was not a single state, but one made up of many Mandela communities owing allegiance to the Ayutthayan king. Often, members of the royal family, or a wealthy elder of the community itself ran these communities. In Ayutthayan society the basic home unit was composed of extended family households. The title to the land resided with the headsman, the head of the household, which held the land although it was in the communitys name. The peasant could use this land freely as long as he was cultivating it. The kings needed to be constantly aware of the princes so that they did not join up and try to usurp the throne. During the 15th centuries much of Ayutthayas power was directed toward the great port of Malacca, on the Malay Peninsula. Although they failed in making Malacca a vassal state, Ayutthaya continued to control the lucrative trade on the Isthmus. The trade then attracted Chinese traders who brought specialty goods from the Chinese markets. Thailand had a unique way of getting labor. It was known as corvee labor or the heaviest tax upon the people. Corvee labor was any free man, or all adult men who where not royalty, nobles, priests or slaves. Corvee laborers were required to give three months of free services to the government...
Saturday, October 19, 2019
Blueprint and Refined Thesis Template
Blueprint and Refined Thesis Template Time can change everything, it may even flip your world upside down in seconds.. If one makes a single wrong move, everybody tends to judge them. This can be clearly seen in Little Deaths by Emma Flint through the theme of the book. Moreover, by using makeup as a mask to hide feelings, and judging someone due to their appearance. This book portrays hardships of a single, driven mother living in a judgemental society. Body The theme of the book clearly showed how one wrong move can change one’s life completely. Helping one find the angel or devil inside them. Moreover, POINT: This quote help show the true side of Ruth, how she cared about her kids. This quote helps ignore other people’s judgemental opinions. â€Å"She stretched out a hand but Devlin was suddenly there, pulling her back. Forbidding her to touch. She opened her mouth, but the flies and the heat and the smell and the sudden awareness that this was the hair she had shampooed and combed and braided for four years made everything go dark for a moment.†COMMENT: This is a clear example that shows how kids require time and attention of parents to survive, otherwise they disappear. This quote helps understand the theme of the book. Ruth is not just a woman that cares about her looks, lovers, and drinks. She has a very soft side for her kids. POINT: This passage expresses the type of mindset Ruth had. She wasn’t very aware of where her kids were. She was also comfortable with the idea of strangers bringing her kids back home after they escape. This suggests that if anything ever went wrong with her kids, she wont know. Unless someone informs her. PROOF: Ruth knew she should be proud of these kids. She should be proud of herself, bringing them up practically alone. They had toys and books, their clothes were neat and clean, they ate vegetables for dinner every night. They were safe here. It was a friendly neighbourhood: when they climbed out of their window back in the spring, an old lady brought them home before Ruth even knew they were gone. COMMENT: Through this passage, Ruths adoration for her children is evidently portrayed. How she provided them with everything they needed and wanted. However, it also show how careless Ruth truly was, as mentioned: when they climbed out of their window back in the spring, an old lady brought them home before Ruth even knew they were gone. Shows how careless she truly was. Unfortunately, even after providing her kids with everything, she failed to take care of them. She was a mother who guaranteed to be dedicated to her youngsters, yet she worked long shifts in a shabby bar as opposed to remaining home to deal with them, and she locked them in their room for quite a long time while she dozed late. Concluding Statement (try and link points made in paragraph back to thesis) Providing kids with what they need or want isn’t enough, one must spend time with their kids. As opposed to leave them alone at house. It’s not wrong to say that Ruth’s worst move was to abandon her kids for long hours. Believing that they lived in a â€Å"friendly neighborhood†and nothing could go wrong. Which eventually led people into judging her after her kids death, and believing that she was the murderer. Topic sentence: Ruths veil of cosmetics, her eagerness on looking right, fills in as a screen on to which social dreams are anticipated. POINT: This passage portrays Ruth’s obsession with looking perfect. Doesn’t matter how critical a situation might be . Also proving that she, once again, cares more about how she looks than her dead children. Moreover, she also tends to use makeup to hide her true feeling that can evidently be felt in this passage. PROOF: ‘She knew that there would be men, strangers, looking at her, asking questions. Their eyes all over her like hands. She had to be ready for them. She had to look right.’ COMMENT: As soon as ruth realizes that cops are on their way to investigate her young childrens murder case. She doesnt hesitate even a bit to fix herself. Ruths fragile cover of cosmetics and pride that also portrays her sadness, and misfortune with an extreme delicacy that is both correct and awful. She was grieving, yet she kept on dressing provocatively and to apply her substantial cover of make-up in the days following the revelation of her kids bodies. POINT: Even during grieving for her children’s death, she couldn’t ignore the thoughts of how she expects herself to look. Again, showing her interests and first priorities. Priorities that depict the importance of her makeup mask she wears, rather than her kids. PROOF: She wiped at it savagely and thought how she must look: smudged and blotched and swollen. Drooling. And for a while she did not care. COMMENT: even during crying for her dead kids, she still hesitated to let out her feelings. Ruth always wanted to present herself elegantly in front of everyone. She cared way too much about her looks and reputation. To the point where her looks were always a bigger concern than anything else. This also hints how Ruth always kept her feelings to herself. As proven by the text: Finally she could weep. Even now she remembers the sweet relief of being able to let go in front of a woman who had seen the worst of her all her life. It was hard for her to express her feelings. Concluding Statement:It was hard for her to express her feelings without being concerned about the way she looks. These insecurities and obsession with looking good destroyed Ruth completely. As people around her judged her, she kept possessing herself over make up. Topic sentence: Society judged Ruth according to her appearance. The fact that she had lovers and drinked a lot, made her an indecent women in the eyes of her community and the police. POINT: Since everyone around Ruth blamed her for her children’s death. Ruth also started believing that it was her fault. Showing how devastated and pitiful she had become. PROOF: her leaking wet body that had betrayed her. It was her fault that someone had taken the children, her fault that Frankie was missing, that Cindy was . . . gone. COMMENT: Women in the modern world are still judged and misunderstood based on their appearance and sexuality more than anything else. People blamed Ruth for her kids death. Which lead her into believing that it was her fault only. POINT: This helps clarify the thoughts of people around Ruth. From police officer to neighbors, they all lead to the same conclusion, that Ruth was the killer. All judged by her appearance and without any evidence. PROOF: Seen through the eyes of the cops, the empty bourbon bottles and provocative clothing which litter her apartment, the piles of letters from countless men and Ruth’s little black book of phone numbers, make her a drunk, a loose woman–and therefore a bad mother. The lead detective, a strict Catholic who believes women belong in the home, leaps to the obvious conclusion: facing divorce and a custody battle, Malone took her children’s lives. (from article) COMMENT: The police just jumped to conclusions without proper investigation. Ruth was also involved with a lot of men, they also couldve been culprit. However, because of Ruths appearance, her drinking and other inappropriate habits. Sbe was automatically considered the murderer. Concluding Statement (try and link points made in paragraph back to thesis) Ruth suffered to prove herself guilty. As she feared of not looking perfect, people around her solved this puzzle, blaming Ruth for her children’s death. Without any evidence, and purely based on Ruths outer appearance. Ruth’s wrong move here was that she still cared more about her looks at such a critical time. Which lead into the whole world pointing fingers at her. CONCLUSION Children require time and consideration of guardians to survive, or else they vanish. If one makes a solitary wrong move, everyone tends to judge them. This can be unmistakably found in Little Deaths by Emma Flint through the epic theme of the book. Also by using cosmetics as a cover to shroud feelings, and passing judgment on somebody because of their appearance. People should start considering the fact that you cant judge a person through their appearance. We might not know what someone else is going through. Either way, no one should have the right to blame someone for such a tragic crime.
Friday, October 18, 2019
Human resources case study Example | Topics and Well Written Essays - 1000 words
Human resources - Case Study Example This method does not require that all these sources be included but the more they are the better. Certainly, there are no known legal limits to the sources of rating that may be invoked in the evaluation of performance. Research indicates that the multiple-input approach has more accuracy and reliability in the final information provided (Bracken et al, 15). Top generate proper feedback it is necessary to ensure that the organisations culture and mission are considered since the purpose of feedback will differ with each sources. The Centre for Persons with Disabilities has a reputation of being an objective and goal oriented institution whose mission is to improve the lives of persons with disabilities as wells the affected families. The institution invests in research, education and training, demonstration services as well as technical assistance. The information gathered from the research is used as a platform for the diagnosis accommodation correction of the various body challenges. It also allows the families to leant new methods and ways of accommodations the affected persons challenge into their daily lives. The education and training aspect ensures that the service providers and families are equipped with techniques of dealing and managing the conditions. Any employee’s evaluation will therefore have to fall in line with the mentioned objectives of the institution to pass for good performance. Julie Williams works at The Centre for Persons with Disabilities as a clerk in the Interdisciplinary Training Division, and she helps children with disabilities to improve their learning process, and will collect data by conducting over the phone surveys, mailing out surveys, possibly emailing surveys. The phone surveys will allow the evaluation to have an interpersonal perspective with the various sources. It allows the evaluation to take into consideration the feeling of
Memogate - Fact, Fiction and Political Lies Essay
Memogate - Fact, Fiction and Political Lies - Essay Example Analogous to Vietnam, the American troops and their allies dug into the urban areas using fortified structures that were seen as impenetrable for organized Taliban and Al-Qaeda troops. This had one major impact – conventional warfare was not possible in Afghanistan anymore as the Taliban and Al-Qaeda could not mount infantry or artillery attacks. Given the limited choices to act, the Taliban and Al-Qaeda turned over to guerilla tactics with special emphasis being placed on suicide bombing runs inside US bases in Afghanistan. Rising causalities inside the US bases as well as on roads throughout Afghanistan forced the US to act once more. In order to deal with the challenges at hand, the military’s top brass and the hawks in Washington decided to escalate troop levels in order to pursue a policy of â€Å"boots on the ground†. The rising troop levels and the enhanced military activity on ground meant that the Taliban and Al-Qaeda needed new places to hide. This was an obvious response from the Taliban and Al-Qaeda as they needed bases to train troops, plan and execute operations, plan for longer term strategies and the like. However, space in Afghanistan was running out for both the Taliban and Al-Qaeda who were on the run given escalated military activity. As a response to this, the Taliban and Al-Qaeda moved over into neighboring Pakistan’s tribal belt. ... The closely knitted extended family structure in the region which sponsored tribalism was also able to help the Taliban and Al-Qaeda in finding shelter. Even though it was obvious where the enemy was stationed, the US troops and their allies could not operate inside Pakistan as they had in Afghanistan. The sanctity of an international border was far too great to be desecrated along with the sensitivities of the Pakistani side. The US was quick to bring in drones to attack targets inside Pakistani territory but this had only limited effect as the results of surgical strikes are incomparable to the results of entire infantry and artillery movements. Consequently the Pakistani military and intelligence agencies were brought in to deal with the situation in the border tribal regions. The US and its allies expected compliance with their goals but the Pakistani intelligence structure had its own objectives lurking under the guise of cooperation. Continuous failure on the part of the Pakist ani military brass led the US and its allies to limit information sharing. As relations became more and more strained, the cooperation between the US and Pakistan came to an all-time low (Kronstadt). The military regime of Musharraf was replaced in time by a democratic government in 2007 that was looking for protection from the US from the very start. As the democratic government leaned towards the US and its objectives, results began to arrive. The Osama bin Laden raid in Abbottabad helped to effectively end the threat for once and for all. However such cooperation by the democratic government put it in direct opposition of the Pakistani military and intelligence agencies. Soon a new controversy in the form of the Memogate
The Visit to Kenya Essay Example | Topics and Well Written Essays - 1000 words
The Visit to Kenya - Essay Example The country had a remarkable and beautiful climate. The wide distribution of green plants all over the place shocked me. The trees and birds were beautiful against clear bright blue skies, this contrasted sharply with Saudi Arabia, and I realized that Africa is so much blessed with a remarkable natural environment. They do not require artificially controlled environments in their homes. The temperatures are exceptionally cool at all times of the day, and I appreciate my cousin for insisting that I visit him in this wonderful part of the globe. I had always been fascinated by the majestic lions since I learned about them in Pre-School and I now had an opportunity to spot one in the wild. After traveling for several hours in the Tsavo plains, our tour guide suddenly told our driver to slow down, and he pointed towards a large tree. The sight was beautiful; I saw the largest lion I have ever seen resting under the tree. We saw very many other beautiful animals in the wild. The clouds opened on our way from the recreational area. It was such a superb thing with a mixture of so many pleasant smells around me. I was taken back to reality when our vehicle skidded and came to a sudden stop, and our driver declared that we were mud stuck. We alighted from the vehicle and Mabrouk solemnly declared that only a tow truck could remove the tour van from the muddy pothole. After several minutes, a number of Africans came clad in bright red clothing and after talking with the driver, for a minute, they succeeded in removing the van from the pothole.
Thursday, October 17, 2019
Car engine danger Essay Example | Topics and Well Written Essays - 250 words
Car engine danger - Essay Example In this case a person was injured in a road accident, as he was hit by a fire engine which had ignored the red light while on duty to save lifes by reaching at the location as soon as possible so that any extra damage to the property and life could be minimized. The key issue in this case was whether there was any immunity and privilege enjoyed by fire extinguishers gave them a right to run over people while on duty and whether any exception exists in favor of emergency services on duty or the general principles of tort of negligence are applicable in these situations. The Court of appeal held in this case that "It is said that, because he was driving a fire engine, he was in a certain privileged position. That is not so. He was not in a privileged position at all. It is perfectly true that, when the bell is clanged, people generally draw aside, but, if they do not draw aside, the driver of a fire engine has no business to charge into them.
English class Essay Example | Topics and Well Written Essays - 750 words - 3
English class - Essay Example Assassinations regularly feature in the game. Fire fighting and flying helicopters are simulated. In the later releases, especially after the grand theft auto 2, players are forced to overcome extreme and unfortunate events like being left for the dead and betrayal. This becomes a motivation for advancing through the criminal ladder in the game leading to the triumph of the character by the end of the story line (Bogenn 79). The game also involves driving taxis and carjacking. The grand theft auto III makes violence to be more realistic and practical to children. The players have opportunities to pay for prostitution services with the aim of recovering health. Then the players can kill to recover the money. The game is seen to be moving from the traditional heroic roles offered by the games to illegal activities. The players are forced to commit a wide variety of crimes (Kutner and Olson 41). The grand theft auto displays a notion where the player only faces short term consequences. In the game, the players end up killing policemen and soldiers. Grand theft auto is said to have controversial content especially with regard to children. The episodes of the game are said to have a grave impact of the children’s behavior. The video game is linked to aggression and addiction to vices and violence. A study in 2001 showed that contents of grand theft auto and similar games lead to increased aggression less pro-social behavior among children (Bogenn 79). The violence practiced in the games makes children be comfortable with antisocial behavior like ignoring the rights of others. Grand theft auto is also said to have positive impacts on children. It’s been argued that it trains children to be team players, competitive and that the video characters are not reflected in the real life situation. Grand theft auto leads to both long term and short term aggressive and violent behavior (Kutner and Olson 41). The video game depicts women as sex objects
Wednesday, October 16, 2019
The Visit to Kenya Essay Example | Topics and Well Written Essays - 1000 words
The Visit to Kenya - Essay Example The country had a remarkable and beautiful climate. The wide distribution of green plants all over the place shocked me. The trees and birds were beautiful against clear bright blue skies, this contrasted sharply with Saudi Arabia, and I realized that Africa is so much blessed with a remarkable natural environment. They do not require artificially controlled environments in their homes. The temperatures are exceptionally cool at all times of the day, and I appreciate my cousin for insisting that I visit him in this wonderful part of the globe. I had always been fascinated by the majestic lions since I learned about them in Pre-School and I now had an opportunity to spot one in the wild. After traveling for several hours in the Tsavo plains, our tour guide suddenly told our driver to slow down, and he pointed towards a large tree. The sight was beautiful; I saw the largest lion I have ever seen resting under the tree. We saw very many other beautiful animals in the wild. The clouds opened on our way from the recreational area. It was such a superb thing with a mixture of so many pleasant smells around me. I was taken back to reality when our vehicle skidded and came to a sudden stop, and our driver declared that we were mud stuck. We alighted from the vehicle and Mabrouk solemnly declared that only a tow truck could remove the tour van from the muddy pothole. After several minutes, a number of Africans came clad in bright red clothing and after talking with the driver, for a minute, they succeeded in removing the van from the pothole.
Tuesday, October 15, 2019
English class Essay Example | Topics and Well Written Essays - 750 words - 3
English class - Essay Example Assassinations regularly feature in the game. Fire fighting and flying helicopters are simulated. In the later releases, especially after the grand theft auto 2, players are forced to overcome extreme and unfortunate events like being left for the dead and betrayal. This becomes a motivation for advancing through the criminal ladder in the game leading to the triumph of the character by the end of the story line (Bogenn 79). The game also involves driving taxis and carjacking. The grand theft auto III makes violence to be more realistic and practical to children. The players have opportunities to pay for prostitution services with the aim of recovering health. Then the players can kill to recover the money. The game is seen to be moving from the traditional heroic roles offered by the games to illegal activities. The players are forced to commit a wide variety of crimes (Kutner and Olson 41). The grand theft auto displays a notion where the player only faces short term consequences. In the game, the players end up killing policemen and soldiers. Grand theft auto is said to have controversial content especially with regard to children. The episodes of the game are said to have a grave impact of the children’s behavior. The video game is linked to aggression and addiction to vices and violence. A study in 2001 showed that contents of grand theft auto and similar games lead to increased aggression less pro-social behavior among children (Bogenn 79). The violence practiced in the games makes children be comfortable with antisocial behavior like ignoring the rights of others. Grand theft auto is also said to have positive impacts on children. It’s been argued that it trains children to be team players, competitive and that the video characters are not reflected in the real life situation. Grand theft auto leads to both long term and short term aggressive and violent behavior (Kutner and Olson 41). The video game depicts women as sex objects
Examples of ways to establish ground Essay Example for Free
Examples of ways to establish ground Essay Produce a briefing document for a new member of staff who will be delivering classes in your specialist area embedding functional skills. The document should demonstrate your understanding of: a) ways to establish ground rules with learners Beginners Massage Course Introductory Weekend Briefing document The aim of the Beginners Massage Course Introductory Weekend is to give people the chance to learn a few basic massage techniques and explore their interest in massage without having to commit to a full study programme. Before embarking on teaching the Intro weekend it is important to understand the need for ground rules: those already set by the organisation/ set by you, set by the learners themselves before /or during the course and rules agreed by both of you. Organisational Please read through our organisational policies procedures including Health Safety Fire policy; this enables you to understand what to do in the event of a fire and to instruct your students/learners on the evacuation procedure. the syllabus gives clear objectives; lesson plans with suggested time frames, how to assess, monitor and review the achievements of the students, different methods of teaching, resources to hand (course manuals,whiteboard etc.), progression routes from beginners, anatomy physiology through to practitioner level and also more course specific health and safety guidelines including advice on dress, jewellery, hygiene, use of equipment and the continuous observation of posture and correct stoke techniques. These provide a structure for the course for you the students to follow, supports the diversification of learning skills (demonstration, verbal, hands on, handouts etc.) and give clear guidelines on where to go next with their knowledge. There are a maximum of 10 students per class with a mix of male female of all ages though minimum age is 21. Due both to the size of the room and our past experience we have found that this is an ideal number for a learning group. Requirements sent to all students at time of booking: please arrive by 9.50am you may wish to change into loose comfortable clothing please bring 2 large bath towels leave all your valuable at home i.e. we rings, necklaces, earrings etc. as we cannot be responsible for any loss or damage to these items as they will have to be removed during the class For the comfort of the student you will be working with, please ensure your nails are short. These requirements ensure the smooth running of the course, all students having correct equipment/can learn equally and the well-being of students. Tutor set At the start of the course it is good practice to establish some basic housekeeping practices: evacuation procedures, whereabouts of toilets, suggested break/lunch times and use of mobile phones. Introduce yourself. This gives a little of your background to the students, gives them an idea of where they can go and your experience. Give a brief overview of the weekend, how it will run Review/ recap at the end of each day what they have learnt and ask if there are any questions/areas that need attention. This way give structure to the course and helps manage expectations for the students. Student led/negotiated Give students opportunity to introduce themselves Students choose to work with another student and this partner can be kept for the whole weekend or they may change. Students are more compliant when they set the rules so allow them to decide if when they are ready to move onto the next technique or wish to review and repeat what they have already done. This way gives opportunity to learn the syllabus whilst allowing some fluidity in what pace the class moves at, allows access for everyone to learn equally and working with individual learning requirements. Understanding more about each other gives a feeling of community or familiarity within the group so mutual respect empathy can take place.
Monday, October 14, 2019
Dual Band Bandpass Filter Using Meandered Ring Resonator
Dual Band Bandpass Filter Using Meandered Ring Resonator Dual band bandpass filter using Meandered ring resonator using loaded DGS Mariselvam V, Raju S Abstract Compact microstrip dual-band bandpass filter (DBBPF) with high selectivity and good suppression for wireless local area networks (WLANs) is proposed utilizing a novel embedded scheme resonator loaded ring resonator DGS. Two passbands are produced by a pair of embedded half-wavelength meandered stepped-impedance resonator (MSIR) and a quad wavelength short stub loaded stepped-impedance resonator (SIR) separately. The loaded DGS avoids the cross talk in the pass band which is useful to achieve very sharp cutoff in the pass band. The resonator is fed by folded T Shaped capacitive source-load coupling microstrip feed line, and four transmission zeros are obtained at both sides of the bands to improve selectivity and suppression. Simultaneously, the size of the filter is extremely compact because embedding half-wavelength MSIR only changes the interior configuration of quad-wavelength SIR. To validate the design method, the designed filter is fabricated and measured. Both simulated and me asured results indicate that good transmission property has been achieved. Keywords: Low-pass filter, spurious rejection, linear phase, ring resonators, microstrip filters microwave filters. 1. Introduction BPFs are important block in RF front-to-end and have drawn much attention since they can reject the useless signals. In [1–3], miniaturized BPFs with high selectivity and enhanced out-of-band performance are designed for wireless communication systems. In recent years, with the development of different wireless standards, such as global system for mobile communication (GSM), wireless local-area network (WLAN) and world interoperability for microwave access (WiMAX), designing multi-band BPFs with miniaturized size, high selectivity and controllable frequencies has become a trend. In [4–6], compact and high selectivity dual-band BPFs are designed by two sets of resonators, stepped-impedance resonators (SIR) and stub-loaded resonators, respectively. For dual-band BPF designs, various approaches have been studied. A simple effective method is to utilize two or three sets of resonators [7–10]. In [7], a high selectivity dual-band BPF is designed by using coupled stepp ed impedance resonators. Each set of resonators operates at a pass band, resulting in controllable frequencies. Unfortunately, it has large size due to the multi-sets of resonators. In this a novel Meandered stepped impedance resonator with loaded DGS is utilized to achieve the desired dual pass band and the size is reduced. The two passbands are generated through respective resonators. High selectivity is obtained by the introduction of several finite attenuation poles in stopband. Compared with the conventional dual band filter, the filter is smaller in size and better in performance. 2. Analysis of stepped impedance resonator To design a DBBPF using SIRs, the properties of SIR must be analyzed first. As shown in Fig. 1, the basic structure of half-wavelength SIR consists of two lines of different characteristic impedances Z1 and Z2 and electrical lengths ÃŽ ¸1 and ÃŽ ¸2. It can be treated as two uniform cells (cell A and cell B). The resonance conditions can be obtained from one of them since the half-wavelength SIR is symmetrical [10]. The impedance of the resonator can be calculated as expression According to the above equation, the resonance appears when Zin is infinite, namely the denominator is equal to zero. As a result, the following expression can be obtained as the resonance condition Where Rz is the impedance ratio. In expression (2), we can see that the resonance conditions are determined by ÃŽ ¸1, ÃŽ ¸2 and Rz. It can adjust these three factors to obtain the resonance that we required, and a dual mode filter can be designed by using SIR. Fig. 1.Basic structure of the half wave length SIR (3) à  ´s1 is the electrical length for the first spurious frequency fs1 .In this paper is to design a good WLAN filter, the first spurious frequency must be avoided at the designed lower passband. 3. Design of DBBPF Fig. 2 shows the transformation process to design an embedded-scheme resonator for DBBPF. In Fig.2 (a) a quad-wavelength short stub loaded SIR is shown. To reduce its size, the SIR is folded as an open-loop. Additionally, the low impedance lines of quad-wavelength short stub loaded SIR are broad enough to provide area for a small resonator, which make it possible to embed a pair of small coupling resonators. So, we replace the low impedance lines with a pair of meandered SIRs, which is shown in Fig. 2(b). To achieve a high performance dual-band filter, it is necessary to introduce transmission zeros at both sides of the bands. Due to the existence of DGS, magnetic coupling takes up dominant position on the short stub loaded SIR shown in Fig. 2(a). On the other hand, as the embedded MSIR is folded as an open-loop, it has the maximum electric field density at the side with an open gap, and the maximum magnetic field density at the opposite side. If the sides with the maximum magnetic f ield of two coupled resonators are proximately placed, the magnetic coupling can be obtained. Therefore, the coupling between the half wavelength SIR loops is also magnetic [15]. So, transmission zeros near the two pass bands can be generated by feeding microstrip feed line with capacitive source-load coupling, which because the counteraction between electric field and magnetic field. These transmission zeros have permits to improve selectivity and suppression of this filter. (b) Fig. 2.Embedded Resonator DBBPF design scheme. A filter proposed for WLAN is shown in Fig. 4.A set of parameters of it is given in Tab.1. 4. Filter Configuration Fig.3.T shaped stub loaded resonator Fig. 2 shows the configuration of the proposed micro strip dual-band BPF. It is composed of two sets of resonators. The outer resonators are stub-loaded resonators operating at the first and two pass band frequencies, i.e., 3.68 GHz and 7.01 GHz. Fig.3 illustrate the configuration of the resonator. It consists of a transmission line of length and a T-shaped stub loaded at the line centre is the overall length of the lines, namely L. L= B1+2d1+2f1+2C2+s1+2f1 Open-circuited coupled-lines with the length C2and gap C1 are employed to realize electrical coupling. Two transmission lines with the characteristic impedance of 50à ¢Ã¢â‚¬Å¾Ã‚ ¦ are connected to the outer resonators, acting as input and output ports. Embedded between the two outer resonators, the inner resonators 2 and3 are used to yield the second pass band at f2. The inner resonators are fed by the outer ones. Using this structure, multi-path coupling can be realized for the pass band, which can help generate a pair of transmission zeros. (a) (b) Fig. 4. Schematic view of the proposed filter (a) Top view (b) Bottom view 5. CSRR DGS UNIT The Ring Resonator structures are designed and produced by applying the Babinet principle to the split ring resonators (SRR). In this way structures with apertures in metal surface are obtained and these CSRRs create negative ÃŽ µ instead of negative ÃŽ ¼ in a narrow range near the resonance frequency. In microstrip technology, left handed Metamaterial structures exhibiting band stop behaviour can be implemented by etching CSRRs in the ground plane, underneath the conductor strip, and along the series capacitive gaps. The gap provides a negative value of the effective permeability up to certain frequency that depends on gap dimensions and separation. The negative ÃŽ µ structure has been obtained by loading a microstrip line with CSRR particles as shown in Fig.4. There are many different parameters that affect resonance frequency of CSRR, most dominant being the permittivity of the substrate and length of the resonator. The resonance frequency is inversely proportional to the length o f the resonator and is directly proportional to the split gap of the resonator. It is considered that the CSRR particle is etched only in the ground plane. CSRR etching depth decides the strength of the resonance increases [12]-[13] In order to improve the sharper cut-off, compact in size and harmonic suppression ability of the conventional dual band pass filter a CSRR is loaded in the bottom of the filter. The CSRR is designed at the anti-resonance frequency. Inherent nature of anti-resonance behaviour, it rejects the frequencies above cut-off frequency. In this way we achieved sharp cut-off.the dimensions of the ring resonator is given in Table.1. 6. Simulated and measured results To validate the characteristics, the proposed dual band filter is fabricated and measured in a FR4 substrate with a relative dielectric constant 4.4 a thickness of 1.6mm has been used in this paper. 50 ohms microstrip feed line with a width of 2.2mm is located at both of the input and output ports.fig 6 shows the photograph of the fabricated dual band filter. Fig.7. depicts the simulated and measured results of the proposed filter simultaneously. Here CST microwave studio is used for simulation and an Agilent network analyser N5230A is used for measurement. The simulated / measured minimum insertion losses are 0.65/0.985dB respectively at 3.684GHz band and 0.98/1.35dB respectively at 7.01 GHz. The size of the proposed layout is 14.5mmX19.9mm. (a) (b) Fig.6. Photograph of the Prototype of dual- band filter (a) top view (b) bottom view (a) (b) Fig.7. Simulated and measured (a) S11 (b) S21 of the proposed filter Tab. 1. Parameters of the proposed filter Tab. 2. Comparison of the proposed filter IL-insertion loss FBW- Fractional Band width 7. Conclusion In this paper, a dual band filter designed by embedded resonator loaded with ring resonator DGS was presented. A t-shaped embedded resonator with capacitive source –load coupling is used for feeding and multiple transmission zeros are created and DGS ring resonator is loaded to improve the performance of the filter. A good quality dual band Bandpass filter operating at 3.684 GHz and 6.83GHz for WLAN is well designed and fabricated .The size of the filter is 14.5X19.9mm which is very small. References JUN, S., K. CHANG., Compact microstrip bandpass filter using miniaturized hairpin resonator. Progress in Electromagnetics Research, PIER 2013, vol. 37, pp. 65–71. DAI, G.L., M.Y. XIA., Novel miniaturized bandpass filters using spiral-shaped resonators and window feed structures. Progress In Electromagnetics Research, PIER 2010, vol. 100, pp. 235–243. WEI. X., P. WANG, AND Y. SHI. M., Compact mixed-cross coupled bandpass filter with enhanced frequency selectivity. Progress In Electromagnetics Research, PIER 2013, vol. 37, pp. 73–82. CHAUDHARY, G., Y. JEONG, J. LIM., Dual-band bandpass filter with independently tuneable center frequencies and bandwidths IEEE Trans. Microw. Theory Tech., 2013, Vol. 61, pp. 107–116. ZHANG, R. AND L. ZHU, Design of a compact dual-band bandpass filter using coupled stepped impedance resonators. IEEE Microw. Wireless. Compon. Lett., 2014, vol. 24, No. 3, pp. 155–157. GAO, L. X. Y. ZHANG, High selectivity dual-band bandpass filter using a quad-mode resonator with source-load coupling. IEEE Microw. Wireless. Compon. Lett. 2013, vol. 23, No. 9, pp. 474–476. ZHANG, S., L. ZHU. Compact tri-band bandpass filter based on ÃŽ »/4 resonators with U-folded coupled-line. IEEE Microw. Wireless. Compon. Lett, 2013, vol. 23, No. 5, pp. 258–260. CHEN, F., C. Q. X. CHU, Design of compact tri-band bandpass filters using assembled resonators. IEEE Trans. Microw. Theory Tech., 2009, Vol. 57, pp. 165–171 XU, K., Y. ZHANG, D. LI, Y. FAN, J. L.-W. LI, W. T. JOINE, AND Q. H.LIU, Novel design of a compact triple-band bandpass filter using short stub-loaded SIRs and embedded SIRs structure. Progress In Electromagnetics Research, PIER 2013, vol. 142, pp. 309–320. PENG, Y., L. ZHANG, Y. LENG, J. GUAN, A compact tri-band pass band filter based on three embedded bending stub resonators. Progress In Electromagnetics Research, PIER 2013, vol. 37, pp. 189–197. RUNQIZHANG, LEIZHU. Y, Design of a compact dual band band pass filter using coupled stepped – impedance resonators. IEEE Micro. Wireless. Compon. Lett, 2014, vol.24, No.3 pp.155-157. RUNQIZHANG, LEIZHU, Synthesis and Design of Wideband Dual-Band Bandpass Filters With Controllable In-Band Ripple Factor and Dual Band Isolation IEEE Trans. Microw. Theory Tech., 2013, Vol. 61, pp. 1820–1828. KARUPPIAH ANNARAM, SURESH NITHYA. Investigation of Compact Low Pass Filter with Sharp Cut–Off using Metamaterial. RADIOENGINEERING, 2013, VOL. 22, NO. 3. BAENA, J. D., BONACHE, J., MARTIN, F., SILLERO, R. M. Equivalent circuit models for split ring resonators, and complementary split ring resonators coupled to planar transmission lines. IEEE Transaction on Microwave Theory and Techniques,2005, vol. 53, no. 4, p. 1451-1461. B. F. ZONG, G. M. WANG, H. Y. ZENG, Y. W. WANG. Compact and High Performance Dual-band Bandpass Filter using Resonator-embedded Scheme for WLANs. RADIOENGINEERING, 2012, VOL. 21, NO. 4.
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