979 resultados para Drake Francis, Sir, 1540?-1596.
Resumo:
Digital image
Resumo:
In uplink OFDMA, carrier frequency offsets (CFO) and/or timing offsets (TO) of other users with respect to a desired user can cause multiuser interference (MUI). In practical uplink OFDMA systems (e.g., IEEE 802.16e standard), effect of this MUI is made acceptably small by requiring that frequency/timing alignment be achieved at the receiver with high precision (e.g., CFO must be within 1 % of the subcarrier spacing and TO must be within 1/8th of the cyclic prefix duration in IEEE 802.16e), which is realized using complex closed-loop frequency/timing correction between the transmitter and the receiver. An alternate open-loop approach to handle the MUI induced by large CFOs and TOs is to employ interference cancellation techniques at the receiver. In this paper, we first analytically characterize the degradation in the average output signal-to-interference ratio (SIR) due to the combined effect of large CFOs and TOs in uplink OFDMA. We then propose a parallel interference canceller (PIC) for the mitigation of interference due to CFOs and TOs in this system. We show that the proposed PIC effectively mitigates the performance loss due to CFO/TO induced interference in uplink OFDMA.
Resumo:
Tämän tutkimuksen tehtävänä on selvittää Francis Watsonin käsitys teologisesta hermeneutiikasta. Tutkielmassa käytetään kolmea tarkentavaa tutkimuskysymystä: Miten Watson hahmottaa tieteellisen raamatuntutkimuksen ja Raamatun teologisen tulkinnan suhteen? Miten Watson näkee raamatuntutkimuksessa historiallisen ja kirjallisen lähestymistavan suhteen toisiinsa? Miten Watson suhtautuu postmodernismiin teologisessa hermeneutiikassaan? Tutkimusmetodina on systemaattinen analyysi. Watsonin teologista hermeneutiikkaa ei ole tutkittu suomeksi ennen tätä työtä ja kansainvälistäkin tutkimusta aiheesta on hyvin vähän. Sen vuoksi tutkimuksessa on pyritty käsittelemään Watsonin teologista hermeneutiikkaa mahdollisimman kattavasti, mutta samalla on jouduttu rajaamaan työn ulkopuolelle osa Watsonin käsittelemistä teemoista, kuten Raamatun feministinen kritiikki ja VT:n ja UT:n suhde. Tutkimuksen päälähteinä ovat Watsonin kirjat Text, Church and World ja Text and Truth, joissa hän analysoi modernia historiallis-kriittistä raamatuntutkimusta, postmodernismia ja kirjallista lähestymistapaa Raamattuun. Watson kritisoi niissä näkemiään ongelmia ja kritiikkinsä pohjalta rakentaa omaa teologista hermeneutiikkaansa. Toissijaisina lähteinä tutkimuksessa on useita Watsonin artikkeleja, jotka tuovat lisävalaistusta Watsonin hermeneuttiseen ajatteluun. Päälähteiksi valitut teokset ja toissijaisiksi lähteiksi valitut artikkelit kattavat laajasti Watsonin hermeneutiikkaa käsittelevät kirjoitukset. Johdannon ja loppukatsauksen lisäksi tutkimus on jaettu neljään päälukuun. Tutkielman toisessa luvussa selvitetään Watsonin näkemys tieteellisen raamatuntutkimuksen ja Raamatun teologisen tulkinnan suhteesta ja havaitaan, että Watsonin mukaan raamatuntutkimuksen tulisi palvella teologista tulkintaa. Watson näkee ongelmallisena modernin raamatuntutkimuksen taipumuksen pitää erillään raamatuntutkimus ja -tulkinta ja luoda vastakkainasetteluja yliopiston ja kirkon, eksegetiikan ja systemaattisen teologian sekä neutraalin ja teologisen tulkinnan välille. Kolmannessa luvussa tarkastellaan Watsonin kritiikkiä historiallis-kriittistä tutkimusta kohtaan ja hänen perustelujaan päätökselle käyttää raamatuntulkinnassa ensisijaisesti tekstien lopullista, kanonista muotoa. Watson tukeutuu perusteluissaan Brevard Childsin kanoniseen lukutapaan ja tekstien yhteisölliseen käyttöön. Havaitaan, että Watson kuitenkin kritisoi kanonista lukutapaa sekä formalismista että sen teologisista sidonnaisuuksista. Watson hakee tukea myös Hans Frein narratiivisesta lähestymistavasta, jota Watson samalla kritisoi totuuskysymyksen ohittamisesta. Lopuksi käsitellään Watsonin yritystä liittää tekstin maailma ja sen taustalla oleva sosio-poliittinen todellisuus toisiinsa. Neljännessä luvussa käsitellään Watsonin yritystä yhdistää historiallinen ja kirjallisuustieteellinen lähestymistapa Raamatun teksteihin. Havaitaan, että Watsonin mielestä historiallis-kriittinen tutkimus polkee paikallaan ja siksi tarvitaan kirjallinen lähestymistapa, joka painottaa tekstin lopullista muotoa. Luvussa osoitetaan, ettei Watson kuitenkaan halua korvata puhtaasti historiallista lähestymistapaa puhtaasti kirjallisuustieteellisellä lähestymistavalla, sillä hän näkee ongelmallisena myös narratiivisen kritiikin taipumuksen käsitellä raamatunkertomuksia fiktiivisinä narratiiveina. Watson pyrkii ratkaisemaan ongelman yhdistämällä historiallisen ja kirjallisuustieteellisen lähestymistavan toisiinsa käsittelemällä evankeliumeja kerrottuna historiana. Viidennessä luvussa selvitetään miten Watson suhtautuu postmodernismiin teologisessa hermeneutiikassaan. Siinä havaitaan, että Watson näkee postmodernismin tarjoavan hyödyllisiä näkökulmia useissa hermeneuttisissa kysymyksissä. Samalla Watson vastustaa postmodernismin näkemystä, ettei teksteillä ole yhtä määrättyä merkitystä ja postmodernin teologian taipumusta viedä Raamatun kertomukselta sen universaali merkitys. Luvussa kuitenkin osoitetaan, että Watsonin antama kuva George Lindbeckin ja Stanley Hauerwasin postmodernista teologiasta on yksipuolinen ja osittain virheellinen.
Resumo:
We analyze the performance of an SIR based admission control strategy in cellular CDMA systems with both voice and data traffic. Most studies In the current literature to estimate CDMA system capacity with both voice and data traf-Bc do not take signal-tlFlnterference ratio (SIR) based admission control into account In this paper, we present an analytical approach to evaluate the outage probability for voice trafllc, the average system throughput and the mean delay for data traffic for a volce/data CDMA system which employs an SIR based admission controL We show that for a dataaniy system, an improvement of about 25% In both the Erlang capacity as well as the mean delay performance is achieved with an SIR based admission control as compared to code availability based admission control. For a mixed voice/data srtem with 10 Erlangs of voice traffic, the Lmprovement in the mean delay performance for data Is about 40%.Ah, for a mean delay of 50 ms with 10 Erlangs voice traffic, the data Erlang capacity improves by about 9%.
Resumo:
Information spreading in a population can be modeled as an epidemic. Campaigners (e.g., election campaign managers, companies marketing products or movies) are interested in spreading a message by a given deadline, using limited resources. In this paper, we formulate the above situation as an optimal control problem and the solution (using Pontryagin's Maximum Principle) prescribes an optimal resource allocation over the time of the campaign. We consider two different scenarios-in the first, the campaigner can adjust a direct control (over time) which allows her to recruit individuals from the population (at some cost) to act as spreaders for the Susceptible-Infected-Susceptible (SIS) epidemic model. In the second case, we allow the campaigner to adjust the effective spreading rate by incentivizing the infected in the Susceptible-Infected-Recovered (SIR) model, in addition to the direct recruitment. We consider time varying information spreading rate in our formulation to model the changing interest level of individuals in the campaign, as the deadline is reached. In both the cases, we show the existence of a solution and its uniqueness for sufficiently small campaign deadlines. For the fixed spreading rate, we show the effectiveness of the optimal control strategy against the constant control strategy, a heuristic control strategy and no control. We show the sensitivity of the optimal control to the spreading rate profile when it is time varying. (C) 2014 Elsevier Inc. All rights reserved.
Resumo:
Two new Ru(II)-complexes RuH(Tpms)(PPh3)(2)] 1 (Tpms - (C3H3N2)(3)CSO3, tris-(pyrazolyl) methane sulfonate) and Ru(OTf)(Tpms)(PPh3)(2)] 2 (OTf = CF3SO3) have been synthesized and characterized wherein Ru-H and Ru-OTf are the key reactive centers. Reaction of 1 with HOTf results in the Ru(eta(2)-H-2)(Tpms)(PPh3)(2)]OTf] complex 3, whereas reaction of 1 with Me3SiOTf affords the dihydrogen complex 3 and complex 1 through an unobserved sigma-silane intermediate. In addition, an attempt to characterize the sigma methane complex via reaction of complex 1 with CH3OTf yields complex 2 and free methane. On the other hand, reaction of Ru(OTf)(Tpms)(PPh3)(2)] 2 with H-2 and PhMe2SiH at low temperature resulted in sigma-H-2, 3 and a probable sigma-silane complexes, respectively. However, no sigma-methane complex was observed for the reaction of complex 2 with methane even at low temperature. (C) 2014 Elsevier B. V. All rights reserved.
Resumo:
An air filled ionization chamber has been constructed with a volume of 552 liters and a wall consisting of 12.7 mg/cm2 of plastic wrapped over a rigid, lightweight aluminum frame. A calibration in absolute units, independent of previous Caltech ion chamber calibrations, was applied to a sealed Neher electrometer for use in this chamber. The new chamber was flown along with an older, argon filled, balloon type chamber in a C-135 aircraft from 1,000 to 40,000 feet altitude, and other measurements of sea level cosmic ray ionization were made, resulting in the value of 2.60 ± .03 ion pairs/cm3 sec atm) at sea level. The calibrations of the two instruments were found to agree within 1 percent, and the airplane data were consistent with previous balloon measurements in the upper atmosphere. Ionization due to radon gas in the atmosphere was investigated. Absolute ionization data in the lower atmosphere have been compared with results of other observers, and discrepancies have been discussed.
Data from a polar orbiting ion chamber on the OGO-II, IV spacecraft have been analyzed. The problem of radioactivity produced on the spacecraft during passes through high fluxes of trapped protons has been investigated, and some corrections determined. Quiet time ionization averages over the polar regions have been plotted as function of altitude, and an analytical fit is made to the data that gives a value of 10.4 ± 2.3 percent for the fractional part of the ionization at the top of the atmosphere due to splash albedo particles, although this result is shown to depend on an assumed angular distribution for the albedo particles. Comparisons with other albedo measurements are made. The data are shown to be consistent with balloon and interplanetary ionization measurements. The position of the cosmic ray knee is found to exhibit an altitude dependence, a North-South effect, and a small local time variation.
Resumo:
William Francis Thompson (1888–1965) was a preeminent fishery scientist of the early to mid twentieth century. Educated at Stanford University in California (B.A. 1911, Ph.D. 1930), Thompson conducted pioneering research on the Pacific halibut, Hippoglossus stenolepis, from 1914 to 1917 for the British Columbia Provincial Fisheries Department. He then directed marine fisheries research for the State of California from 1917 to 1924, was Director of Investigations for the International Fisheries Commission from 1924 to 1939, and Director of the International Pacific Salmon Fisheries Commission from 1937 to 1942. He was also Director of the School of Fisheries, University of Washing-ton, Seattle, from 1930 to 1947. Thompson was the founding director in 1947 of the Fisheries Research Institute at the University of Washington and served in that capacity until his retirement in 1958. He was a dominant figure in fisheries research of the Pacific Northwest and influenced a succession of fishery scientists with his yield-based analysis of fishery stocks, as opposed to studying the fishes’environment. Will Thompson was also a major figure in education, and many of his former students attained leadership positions in fisheries research and administration.
Resumo:
William Francis Thompson (1888–1965), as a temporary employee of the British Columbia Provincial Fisheries Department, was assigned in 1914 to under-take full-time studies of the Pacific halibut, Hippoglossus stenolepis. The fishery was showing signs of depletion, so Thompson undertook the inquiry into this resource, the first intensive study on the Pacific halibut. Three years later, Thompson, working alone, had provided a basic foundation of knowledge for the subsequent management of this resource. He published seven land-mark papers on this species, and this work marked the first phase of a career in fisheries science that was to last nearly 50 years.
Resumo:
William Francis Thompson (1888–1965), an early fishery biologist, joined the California Fish and Game Commission in 1917 with a mandate to investigate the marine fisheries of the state. He initiated studies on the albacore tuna, Thunnus alalunga, and the Pacific sardine, Sardinops sagax, as well as studies on other economically important marine organisms. Thompson built up a staff of fishery scientists, many of whom later attained considerable renown in their field, and he helped develop, and then direct, the commission’s first marine fisheries laboratory. During his tenure in California, he developed a personal philosophy of research that he outlined in several publications. Thompson based his approach on the yield-based analysis of the fisheries as opposed to large-scale environmental studies. He left the state agency in 1925 to direct the newly formed International Fisheries Commission (now the International Pacific Halibut Commission). William Thompson became a major figure in fisheries research in the United States, and particularly in the Pacific Northwest and Alaska, during the first half of the 20th cent
Resumo:
William Francis Thompson (1888–1965), as a temporary employee of the British Columbia Provincial Fisheries Department, was assigned in 1914 to under-take full-time studies of the Pacific halibut, Hippoglossus stenolepis. The fishery was showing signs of depletion, so Thompson undertook the inquiry into this resource, the first intensive study on the Pacific halibut. Three years later, Thompson, working alone, had provided a basic foundation of knowledge for the subsequent management of this resource. He published seven land-mark papers on this species, and this work marked the first phase of a career in fisheries science that was to last nearly 50 years.
Resumo:
O colono português Gabriel Soares de Sousa apresentou à corte de Felipe II da Espanha, por volta de 1587, um dos mais importantes registros sobre o Brasil quinhentista, o Tratado descritivo do Brasil em 1587, e o bem menos conhecido Capítulos de Gabriel Soares de Sousa contra os padres da Companhia de Jesus no Brasil. Esta tese apresenta uma análise da história destes manuscritos quinhentistas, examinado como chegaram até os seus formatos atuais e as suas leituras através dos tempos.