Poems Coursework Example | Topics and Well Written Essays - 750 words

Poems - Coursework Example In as much the poem was almost balanced in three perspective of senses, the sense of smell was least explored. The central message and theme in this poem revolve around change. The persona is an elderly person that re-think on the gone days with nostalgia and admire the days that he was young with strength. The poet has used parallels of the age of persona and the changes in weather where the persona is think his youthful days in terms of spring, when the ice was braking of ice and the summer time when the persona was gaming in hot sun. The changes in weather and climatic condition have been mirrored in the life of the persona who think that he is re-living the gone days. To that effect, the poet wanted to give message on change, how things and event recur but the only thing that change is doing the things that one did in youthful life with the vitality and energy at the elderly age. The change in age is not limited to the setting of the poem but universal though the imagery and parallel are limited to the setting of poem. Stanza one explains the stubborn exploration of human being on earth in a cyclic manner one after the other. There is logging and deforestation that is ongoing where human being re-settle on lands that had earlier been settled on. Stanza two ostensibly explain the exploration and the rational. There is preparation for the season where ploughing is ongoing to plant new crops. The main message on this stanza is that the land was previously owned by someone who sold it. In stanza three, it shows the remnants of machines used to explore the earth that have been rendered useless. They are waiting for the reselling or auction by willing buyers. This emphasizes the cyclic nature of earth exploration. Stanza four is indicative of the claimants who once owned the land but now they are bereaved of their ownership. The â€Å"three lived and played† around the land that is under new ownership. In entirety the owners of the land

Spatial Decoupling methods for Digital Suscriber Line

Spatial Decoupling methods for Digital Suscriber Line In this paper, we present a novel method of spatial decoupling method to the pre- and post-processing of bundled digital subscriber line (DSL) systems using polynomial matrix decomposition algorithms. The proposed algorithm introduce a novel analysis and synthesis frequency splits in addition to upper frequency limits that play a major part in achieving the expected data rates. Instead of the traditional discrete multitone (DMT) architecture, sophisticated modulation structures known as filtered multitone (FMT) precoder for the downstream, and its upstream counterpart an inverse FMT equalizer are evaluated. Simulation results confirm that per-band equalization of polynomial matrices can enhance data rates by using this proposed spatial decoupling approach for DSL lines. Index Terms- Polynomial Matrix Decomposition, Filtered Multitone, DSL, DMT, WHAT IS OFDM? In this paper, we present the foundation for a future generation of spatial decoupling method to the pre- and post-processing of bundled digital subscriber lines (DSL) systems. The paper proposed a new analysis and synthesis frequency splits in addition to upper frequency limits that play a major part in achieving the expected data rates. Instead of the traditional discrete multitone (DMT) architecture, a more sophisticated filtered modulation structure known as filtered multitone (FMT) is proposed in the downstream, and its upstream counterpart an inverse FMT operation. DSL have for decades used DMT to allow the transmission of several high speed broadband signals through the twisted pair copper wire at the same time. Each broadband signal is on a separate frequency or, more specifically, assigned to independent DSL tone/ channel. For instance, what we call Channel 2 occupies 54 MHz-60 MHz. Within each channel used for NTSC analog TV transmission, one will find an amplitude modulated (more specifically, vestigial sideband amplitude modulation or VSB-AM) visual carrier located 1.25 MHz above the lower channel edge, and a frequency modulated aural carrier 4.5 MHz above the visual carrier. A color subcarrier is located in between the visual and aural carriers, approximately 3.58 MHz above the visual carrier. When the cable industry made the jump to digital transmission several years ago, the modulation of choice was QAM. Each downstream QAM signal which is really a double-sideband, suppressed-carrier analog RF signal occupies the same six megahertz of bandwidth as an analog TV signal. The current method of QAM transmission is known as single carrier QAM (SC-QAM); the latter is true even when DOCSIS 3.0 channel bonding is used. Each channel slot carries only one modulated carrier a QAM signal hence, the SC-QAM moniker. The entire data payload transmitted in the channel modulates just that one QAM signal. Now imagine transmitting a large number of individual very-narrow-bandwidth QAM signals hundreds or even thousands within a given channel. A 6-megahertz-wide channel could, for example, contain up to 480 narrow QAM signals that are spaced only 12.5 kilohertz apart. Each of these narrow QAM signals, called a subcarrier, subchannel, or carries a small percentage of the total payload at a very low data rate. The aggregate of all of the subcarriers data rates comprises the total data payload. For improved spectral efficiency, the subcarriers actually overlap one another. This sounds counterintuitive, because one would be inclined to think that, if signals overlap each other, interference will occur. With OFDM, the subcarriers are mathematically orthogonal to that is, distinguishable from one another, which takes care of the interference concern. Orthogonal in this case means the subcarriers are independent such that there is no interaction between them despite the overlap in frequency. The concept is analogous to having zero inter-symbol interference (ISI) in the time domain. Orthogonality is achieved by spacing the subcarriers at the reciprocal of the symbol period (T), also called symbol duration time. This spacing results in the sinc (sin x/x) frequency response curves of the subcarriers lining up so that the peak of one subcarriers response curve falls on the first nulls of the lower and upper adjacent subcarriers response curves. Orthogonal subcarriers each have exactly an integer number of cycles in the interval T. With OFDM, the concept of a six-megahertz-wide channel no longer is necessary. The previously mentioned NCTA paper includes an example of a downstream OFDM channels bandwidth being as wide as 192 megahertz, supporting some 15,200 subcarriers spaced 12.5 kilohertz apart. Along with the subcarriers are pilot tones for synchronization and other purposes. There are guard bands at each end of the 192- megahertz-wide channel, resulting in a useful bandwidth of 190 megahertz. The useful symbol duration time is 80 microseconds (ÂÂ µs), the reciprocal of which is the previously noted subcarrier spacing: 1/0.000080 second = 12,500 hertz. The total symbol duration time is 84.13 ÂÂ µs, which includes what are called guard interval samples and symbol shaping samples. Assuming 4096-QAM on each subcarrier, the 192- megahertz-wide channel supports 2.11 Gbps without FEC. Other example channel bandwidths discussed are 96 megahertz and 48 megahertz. All of these particular OFDM channel bandwidths are multiples of six and eight megahertz, which allows easier coexistence with todays North American and European channel plans. If the spectrum doesnt have enough room for a full OFDM channel, some of the subcarriers can be nulled, which effectively turns them off. OFDM can be used for multiple access say, as OFDMA in the upstream by assigning different subcarriers to different users. OFDM also can be used in combination with such other multiple access schemes as time division multiple access (TDMA). In this case, the full channel would be assigned to one user at a time, and the multiple access achieved via time division. When combined with TDMA, OFDM can deliver a very high peak-data rate, which may be desirable for some applications. Pros And Cons Advantages of OFDM include the ability to adapt to such degraded channel conditions as severe microreflections without the need for complex adaptive equalization algorithms. One reason for the latter is that a very narrow bandwidth subcarrier typically experiences what is known as flat fading when micro-reflections affect channel response. This is in contrast to a SC-QAM signal that occupies the full channel bandwidth and is susceptible to amplitude ripple (standing waves) across that full bandwidth. Each OFDM subcarrier sees just a tiny portion of the ripple, which for the most part affects only the amplitude of the narrow subcarrier. Compensating for what amounts to little more than an amplitude variation among subcarriers simplifie s the fix. Likewise, the composite OFDM signal is more robust than SC-QAM in the presence of interference. For example, a narrowband ingressor like a pager transmitters signal affects only a few subcarriers rather than taking out the full channel. Depending on the severity of the interference, FEC may be able to deal with it. Alternatively, the OFDM transmitter simply can disable a few subcarriers to avoid narrowband interference on problem frequencies. Inter-symbol interference is generally less of a problem with OFDM because of the low data rate per subcarrier. As discussed earlier, the overlapping nature of OFDMs subcarrier transmission provides high spectral efficiency. If information about the channels condition is sent back to the transmitter by the receiver, then adaptive modulation, FEC and power allocation can be applied to all subcarriers, blocks of subcarriers or even individual subcarriers. In other words, some subcarriers in the channel can use higher orders of modulation than other subcarriers, some subcarriers can have more aggressive FEC, and the power of individual subcarriers can be varied all on an as-conditions-warrant basis. OFDM does have a few disadvantages: It is susceptible to frequency and clock errors, although the pilot carriers that accompany the subcarriers help to mitigate this by providing the receiver a means of synchronization. OFDM has a high peak-to-average power ratio (PAPR), but a spectrum full of SC-QAM signals does, too. While PAPR-reduction techniques are available for OFDM and OFDMA, they probably wont be necessary in a typical cable network. Some of OFDMs high spectral efficiency is reduced by the use of cyclic prefixes, which help to maintain subcarrier orthogonality. Why Bother? You may be wondering why one would even consider a new PHY for a possible future version of DOCSIS. After all, SC-QAM works well, and channel bonding can be used to significantly increase data throughput. The good news is that OFDM isnt some new-fangled technology without a proved history. It is used in Wi-Fi networks, worldwide interoperability for microwave access (WiMAX), long term evolution (LTE), digital audio broadcasting (DAB), ultra-wideband (UWB) and Europes digital video broadcasting (DVB). A variation of ODFM also is used in asymmetric digital subscriber line (ADSL) and very high-speed digital subscriber line (VDSL). The previously discussed advantages bring a lot of signal transmission flexibility to the table. When OFDM is combined with more powerful FEC like LDPC, higher orders of modulation can be used within the limits of the channel conditions, of course. Toss in new frequency splits and upper frequency limits seem improving the future DSL systems, supporting far higher data rates than are possible the existing DMT-QAM.

Peyote and Native American Culture Essay example -- Botany Biology Res

Peyote and Native American Culture Peyote was originally described in 1560, however it was not until the middle of the nineteenth century that botanists were able to conduct field research and correctly classify the cactus (Anderson, 1980). Field studies have concluded that there are two distinct populations of peyote which represent two species. The first and most common, Lophophora williamsii extends from southern Texas reaching south to the Mexican state of San Luis Potosi. The second and least common of the two species is Lophophora difusa, which occurs in the dryer terrain of the Mexican state of Queretaro. This species differs from the more common species by, "being yellowish-green rather than blue green in color, by lacking any type of ribs or furrows, by having poorly developed podaria (elevated humps), and by being a softer, more succulent plant" (Anderson 1980). Native Americans use peyote in their religious practices because of its psychoactive properties, and is usually eaten as mescal buttons, the dried, brown pieces of the above part of the cactus (Lewis, 1977). The peyote religion is ancient in its origin and spread from Mexico, North in the mid 1800's at a time when Native Americans were desperately in need of spiritual strength and enlightenment, Native Americans were confined to reservations which were overseen by military authority, while many of their ritualistic practices and traditions were deemed as illegal. Origin stories regarding the practice of peyote ritual vary, however all encompass a common theme, namely that the 'Supernatural' took pity on those persecuted and communicated spiritually to the Native Americans through the journey experienced while under the chemical effects of peyote (Steltenka... ...s as an escape from the world the white man created. The impact this plant has had on civilization is that it is only way out for some, it is their vehicle of escape to drive them out of the material world and down the peyote road. Bibliography Anderson, E. 1980. Peyote, The Divine Cactus. Arizona: University of Arizona Press. Boyer, B., Boyer, R., & Basehart, H. 1973. Hallucinogens and Shamanism M. Hamer, Ed.. England: Oxford University Press. Csordas, T., Kiyaani, M. 1997, March. On the Peyote Road. Natural History, 106,48. Lewis, W. 1977, Medical Botany. New York: Wiley. Steltenkamp, M. 1982. The Sacred Vision. New Jersey: Paulist Press. Stewart, 0. 1987. Peyote Religion. Oklahoma: University of Oklahoma Press. Swan, D. 1998. Early Osage Peyotism. Plains Anthropologist, 43(163), 51-71. Unknown, The Peyote Religion. www.peyote.net. Peyote and Native American Culture Essay example -- Botany Biology Res Peyote and Native American Culture Peyote was originally described in 1560, however it was not until the middle of the nineteenth century that botanists were able to conduct field research and correctly classify the cactus (Anderson, 1980). Field studies have concluded that there are two distinct populations of peyote which represent two species. The first and most common, Lophophora williamsii extends from southern Texas reaching south to the Mexican state of San Luis Potosi. The second and least common of the two species is Lophophora difusa, which occurs in the dryer terrain of the Mexican state of Queretaro. This species differs from the more common species by, "being yellowish-green rather than blue green in color, by lacking any type of ribs or furrows, by having poorly developed podaria (elevated humps), and by being a softer, more succulent plant" (Anderson 1980). Native Americans use peyote in their religious practices because of its psychoactive properties, and is usually eaten as mescal buttons, the dried, brown pieces of the above part of the cactus (Lewis, 1977). The peyote religion is ancient in its origin and spread from Mexico, North in the mid 1800's at a time when Native Americans were desperately in need of spiritual strength and enlightenment, Native Americans were confined to reservations which were overseen by military authority, while many of their ritualistic practices and traditions were deemed as illegal. Origin stories regarding the practice of peyote ritual vary, however all encompass a common theme, namely that the 'Supernatural' took pity on those persecuted and communicated spiritually to the Native Americans through the journey experienced while under the chemical effects of peyote (Steltenka... ...s as an escape from the world the white man created. The impact this plant has had on civilization is that it is only way out for some, it is their vehicle of escape to drive them out of the material world and down the peyote road. Bibliography Anderson, E. 1980. Peyote, The Divine Cactus. Arizona: University of Arizona Press. Boyer, B., Boyer, R., & Basehart, H. 1973. Hallucinogens and Shamanism M. Hamer, Ed.. England: Oxford University Press. Csordas, T., Kiyaani, M. 1997, March. On the Peyote Road. Natural History, 106,48. Lewis, W. 1977, Medical Botany. New York: Wiley. Steltenkamp, M. 1982. The Sacred Vision. New Jersey: Paulist Press. Stewart, 0. 1987. Peyote Religion. Oklahoma: University of Oklahoma Press. Swan, D. 1998. Early Osage Peyotism. Plains Anthropologist, 43(163), 51-71. Unknown, The Peyote Religion. www.peyote.net.

American Slavery

Political Points of View: American Slavery In the autobiography, The Narrative of the Life of Frederick Douglass, writes of the Incident when he defends himself against the cruel Mr. Covey. Harriet A. Jacobs also writes in her autobiography, Incidents in the Life of a Slave Girl, of the time she decides to escape from her owners. Spirituals were extremely emotional songs that were often sung by American slaves. Harriet Tubman, a famous â€Å"conductor† or guide that helped free slaves, was interviewed and her stories were published of what she s an abolitionist went through.One similarity they all have is after being pushed too far, they resist against their suppressors. Douglas's way of resisting injustice was defending himself against Mr. Covey. Mr. Covey was a cruel man that Douglass was loan out too. â€Å"l resolved to fight. † what was Douglass determined as he equally hurt Mr. Covey who had beat him previously day after day. I believe Frederick Douglass did the r ight thing even though extremely risky. Harriet A. Jacobs also resisted injustice by escaping her owner, Mr.Flint, and oing to hide at relatives or friends houses, but close enough to keep an eye on her children. â€Å"l groped my way tothe road.. † a quote Jacobs wrote in her autobiography of when she escaped. Even though though risky, Jacobs escaped to try and keep her children safe. knowing that If she took them with her they would give them away or they wouldn't be touched by Mr. Flint since he believed she would return for them. Both went to hardships but found ways and the strength to rise up. Harriet Tubman created the underground railroad. which allowed many salves to scape to the free states.Tubman ,herself a former slave, was the most wanted fugitive of the era and although knowing the dangers still continued leading the underground railroad. Tubman tried to get her brothers to Join her to freedom but they refused. However, she didnt let that stop her. â€Å"She wa lked off alone, following the guidance of the brooks which she observed to run North. † Many American slaves were also known to sing spirituals. Spirituals tended to have codes, or expressed on how Americans slaves really felt about slavery. Spirituals were â€Å"moving and intensely emotional songs. In a sense I feel spirituals created a sad, depressing atmosphere, since many songs were sung that way. However, many were Spirituals were extremely helpful to Tubman and others to become free. Many American slaves were too afraid to rise up, but a few did.

Historical biases and how the truth was altered Essay

Taking into account the nature of historical truth, it cannot be viewed from absolutist position, but rather from relativist perspective. The values, dictated by the certain epoch, determine the purpose and the context of history, so there is a number of historical biases (again, from modern viewpoint) in the writings, describing and explaining the past experiences. The paper is designed to focus on the main historical biases and highlight the influence of modern media on the construction of new biases. Due to the fact that there is a plenty of historiographic schools, one can presume that each of them chooses specific symbol or aspect as a baseline and develops its argument through certain prism. In this sense, the book by Edwars Said, ‘Orientalism’, to great extent emphasizes the faultiness of Western historiographic approach to the diametrically opposite culture. The scholar writes: â€Å"The Orient is not only adjacent to Europe; it is also the place of Europe’s greatest and richest and oldest colonies, the source of its civilizations and languages, its cultural contestant, and one of its deepest and most recurring images of the Other† (Said, 1979, pp. 1-2). Orientalism therefore comprises the historically biased attitude towards the cultural ‘otherness’, so the author concludes that eastern studies cannot be completely independent from the polarization and confrontation between the two civilizations. Furthermore, social stratification determined the status of certain individual in society and consequently resulted in the creation of ‘middle class’ or ‘aristocratic’ approach to making historical notes, and, more importantly, religious approach had been predominant in this sense over more than a thousand years the issues related to heresy and Inquisition contributed to medieval historiography, whereas the social protest against religious dogmas was an overall Western historiographic framework in the 18th -20th centuries. Both approaches naturally distorted objective reality in an attempt to fit it into narrow Procrustean bed of sociopolitical context. Furthermore, it is important to keep in mind that the purpose of history hasn’t been static over the societal developmental course – it has altered a number of times – from the simple glorification of the certain ruler’s deeds to the formation of public consciousness and stereotypes. Historians, as the members of society, naturally shared most stereotypes and social convictions , even writing purely ‘for the sake of history’. Nowadays, historical biases are close-knit to the issues, which arise in connection with social, gender and racial equality, so the modern media are concentrating on covering these issues and determining public opinion. Information therefore is presented is extremely available manner, which allows remembering the content of the article without any ‘unnecessary’ reflections or more profound analysis. The ‘raw’ information (news, editorials) has attractive cover, so the digestion and informational metabolism have been enhanced over the last century, whereas the description of events still remains biased in terms of the author’s political and social position, or personal views. On the other hand, the freedom of printed word prohibits the misrepresentation of facts, yet the interpretation of certain data still may vary among journalists – this principle is widely used to put the most appropriate and suitable emphases, thus except the provision of recent news, media are responsible for creating images, persuading public and imposing certain moral or ethical evaluation of the event or phenomenon (for more utility and convenience, from the position of ‘right’ and ‘wrong’). To sum up, it is impossible to eradicate historical biases – historiography, like all descriptive and analytical sciences, follows relativist principles of ‘minor’ or ‘major’ truth. Nevertheless, with regard to high availability of historical writings, one has an opportunity to analyze the positions of several historiographic schools and draw more independent conclusions.