5,538 research outputs found

    Do Young Neutron Stars Which Show Themselves As AXPs, SGRs and Radio Pulsars Accrete?

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    We examined the fall-back disk models, and in general accretion, proposed to explain the properties of anomalous X-ray pulsars (AXPs), soft gamma repeaters (SGRs), and radio pulsars (PSRs). We checked the possibility of some gas remaining around the neutron star after the supernova explosion. We also compared AXPs and SGRs with the X-ray pulsars in X-ray binaries. We conclude the existing models of accretion from a fall-back disk are insufficient to explain the nature of AXPs/SGRs, particularly the SGR bursts. We also discussed the proposed model of combination of magnetic dipole radiation and propeller torques in order to explain the evolution of radio pulsars on the P-\.{P} diagram. The predictions of this model contradict the observational data.Comment: 16 Pages, 1 Figur

    Search for a Standard Model Higgs Boson in CMS via Vector Boson Fusion in the HWWlvlvH \to WW \to lvlv channel and Optimization of ENergy Reconstruction in CMS using Test Beam 2006 Data

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    One of the goals of the LHC is to test the existence of the Higgs boson. This thesis presents a study of the potential to discover the Standard Model Higgs boson in the vector boson fusion *VBF) channel for the Higgs mass range 120-200 GeV/c^2. The decay of Higgs bosons into the WW* final state with both W bosons decaying leptonically is considered. The main backgrounds are ttbar+j and W+W-jj. This study, based on a full simulation of the CMS detector at the LHC, shows that a 5 sigma discovery can be done with an integrated luminosity of 12-72 fb^-1 for 130-200 GeV/c^2 Higgs bosons. Due to the uncertainties in the backgrounds, it is important to measure the backgrounds from data. This study shows that the major background can be measured directly to 7% with 30 fb^-1. After discovering the Higgs boson, it will be crucial to probe its physical properties. A method to measure the Higgs boson mass using transverse mass template distributions is investigated in the VBF channel. The performance of the combined CMS electromagnetic and hadronic calorimeters (EB+HB) was measured at the H2 test beam at the CERN SPS during 2006 with various particles in a large momentum range, 1-350 GeV/c. Another major contribution of this thesis is developing the method to optimize the energy reconstruction for the combined EB+HB system with which the corrected responses become 100% with 6% fluctuation and the stochastic resolution is improved from 111% to 94%

    Emitter Location Finding using Particle Swarm Optimization

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    Using several spatially separated receivers, nowadays positioning techniques, which are implemented to determine the location of the transmitter, are often required for several important disciplines such as military, security, medical, and commercial applications. In this study, localization is carried out by particle swarm optimization using time difference of arrival. In order to increase the positioning accuracy, time difference of arrival averaging based two new methods are proposed. Results are compared with classical algorithms and Cramer-Rao lower bound which is the theoretical limit of the estimation error

    A Linear Iterative Unfolding Method

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    A frequently faced task in experimental physics is to measure the probability distribution of some quantity. Often this quantity to be measured is smeared by a non-ideal detector response or by some physical process. The procedure of removing this smearing effect from the measured distribution is called unfolding, and is a delicate problem in signal processing, due to the well-known numerical ill behavior of this task. Various methods were invented which, given some assumptions on the initial probability distribution, try to regularize the unfolding problem. Most of these methods definitely introduce bias into the estimate of the initial probability distribution. We propose a linear iterative method, which has the advantage that no assumptions on the initial probability distribution is needed, and the only regularization parameter is the stopping order of the iteration, which can be used to choose the best compromise between the introduced bias and the propagated statistical and systematic errors. The method is consistent: "binwise" convergence to the initial probability distribution is proved in absence of measurement errors under a quite general condition on the response function. This condition holds for practical applications such as convolutions, calorimeter response functions, momentum reconstruction response functions based on tracking in magnetic field etc. In presence of measurement errors, explicit formulae for the propagation of the three important error terms is provided: bias error, statistical error, and systematic error. A trade-off between these three error terms can be used to define an optimal iteration stopping criterion, and the errors can be estimated there. We provide a numerical C library for the implementation of the method, which incorporates automatic statistical error propagation as well.Comment: Proceedings of ACAT-2011 conference (Uxbridge, United Kingdom), 9 pages, 5 figures, changes of corrigendum include

    CMF-DFE Based Adaptive Blind Equalization Using Particle Swarm Optimization

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    The channel matched filter (CMF) is the optimum receiver providing the maximum signal to noise ratio (SNR) for the frequency selective channels. The output intersymbol interference (ISI) profile of the CMF convolved by the channel can be blindly obtained by using the autocorrelation of the received signal. Therefore, the inverse of the autocorrelation function can be used to equalize the channel passed through its own CMF. The only missing part to complete the proposed blind operation is the CMF coefficients. Therefore, in this work, the best training algorithm investigation is subjected for blind estimation of the CMF coefficients. The proposed method allows using more effective training algorithms for blind equalizations. However, the expected high performance training is obtained when the swarm intelligence is used. Unlike the stochastic gradient algorithms, the particle swarm optimization (PSO) is known to have fast convergence because its performance is independent of the characteristics of the systems used. The obtained mean square error (MSE) and bit error rate (BER) performances are promising for high performance real-time systems as an alternative to non-blind equalization techniques

    Rural landscape planning in agro-tourism and agri-tourism

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    Turizm ülke ekonomisi için gelir getirici önemli bir kaynaktır. Turizm ile ülkemizin doğal ve kültürel peyzaj varlıklarının değerlendirilmesi, hizmete sunulması ve bu faaliyetlerden kazanç sağlanması temel amaçtır. Ancak plansız yada sadece otel işletmesine dayanan bu turizm şekli doğanın tahrip olmasına, doğal ve kültürel peyzaj özelliklerinin bilinçsizce kullanılmasına yada yok edilmesine sebep olmaktadır. Agroturizm ve agriturizm bu sebeplerden dolayı ortaya çıkan turizm çeşitleridir. Son yıllarda önem kazanan bu turizm çeşitleri doğayla barışık olmakla birlikte, var olan doğal ve kültürel peyzaj değerlerinin korunmasını, tanıtılmasını ve sürdürülebilirliğini amaçlamaktadır. Ülkemizin turizm ve kırsal peyzaj potansiyeli içinde agro ve agri turizmin önemi her yıl artmaktadır. Bu çalışmada kırsal peyzaj planlamada agro ve agri turizm nedir, uygulama şartları, genel özellikleri, birbirinden farkı, ülkemiz açısından turizm potansiyeline katkısı ve önemi incelenmiştirTourism is an important source of income for the country's economy. The main purposes are tourism and evaluation of assets of our country's natural and cultural landscape and earnings from these activities to ensure service delivery. However, unplanned, or only form of tourism that is based on the nature of the hotel that was destroyed, the destruction of the natural and cultural landscape features or use of the unconscious causes. Agro-tourism and Agri-tourism are the reason for a wide variety of emerging tourism. Gained prominence in recent years, although these kinds of tourism in harmony with nature, the conservation of existing natural and cultural landscape, the introduction and sustainability aims. İn our country the importance of Agri, Argo tourism in the potantial of rural landscape and tourism is increasing every year. İn this reaserch, the meaning of agri and agro tourism in landscape planning, application requirements, general characteristics, the difference between and importance of the contribution of tourism potential investigated

    Smart Textiles for Soldier of the Future

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    The textile-based materials, equipped with nanotechnology and electronics, have a majorrole in the development of high-tech milltary uniforms and materials. Active intelligent textilesystems, integrated to electronics, have the capacity of improving the combat soldiers performanceby sensing, adopting themselves and responding to a situational combat need allowing thecombat soldiers to continue their mission. Meantime, smart technologies aim to help soldiersdo everyth~ngth ey need to do with a less number of equipment and a lighter load. In this study,recent developments on smart garments, especially designed for military usage owing to theirelectronic functions, and intelligent textlle-based materials that can be used in battlefield, areintroduced

    KAYSERİ KENT BÜTÜNÜNÜN AÇIK VE YEŞİL ALANLARININ SİSTEM YAKLAŞIMI İLE DEĞERLENDİRİLMESİ

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    In urban environments green areas play an important part in forming good qualityenvironments with their ecological, economical, physical, social and aesthetic functions. Open and greenarea systems contribute the formation of urban communities by creating more livable environments. Inthis reseearch open and green areas have been searched in the frame of urban planning. New ideas on“open and green area system” have been developed. So, open and green area system is consist of threeseperate system components as “spatial, social and time”. The spatial system of open and green areas isrelated to their spatial connections. For forming a spatial system that is related to open and green areas,these areas must design as linked with each other and be costituted a spatial cotinuity. The system fromthe social point of view is related to the distribution of open and green areas according to the settlementhierarchy and social requirement. The system from the time point of view is constituted with providingthe historical continuity of open and green areas and their improvement. In Kayseri City, spatialcontinuity of open and green areas haven’t been provided. However, on the urban complex scale, thereare important potential areas for forming an open and green area system in the vicinity of the city. Butthese areas are under the threat of urban development. With an approach that is largely aboutconservation, a continuity that is related to time, can be provided. When the subject is considered fromthe social point of view, it can be seen that open and green areas are not enough in different scales in thecity. With the precautions that will be taken, an open and green area system can be provide in Kayseriurban complex. In this context, the results of the research present recommendations for an effective use of urban open and green areas of Kayseri for urban inhabitants.Kentsel ortamlarda yeşil alanlar ekolojik, ekonomik, fiziksel, toplumsal, estetik işlevleri ilekaliteli yaşam çevrelerinin oluşumunda önemli rol oynamaktadırlar. Açık ve yeşil alan sistemleri dahayaşanabilir çevreler oluşturarak “kentlileşmeye katkıda bulunmaktadırlar. Bu çalışmada açık ve yeşilalanlar kent planlama ile ilişkileri çerçevesinde ele alınmış, “açık ve yeşil alan sistemi” yaklaşımı üzerinedüşünceler geliştirilmiştir. Buna göre açık ve yeşil alan sistemi, mekansal, zamansal ve toplumsal açıdanolmak üzere üç ayrı sistemin birlikteliğinden oluşmaktadır. Açık ve yeşil alanların mekansal sistemi,onların birbirleri ile olan mekansal ilişkileriyle ilgilidir. Açık ve yeşil alanlara ilişkin mekansal bir sistemoluşumu için, bu alanlar birbirleri ile bağlantılı olarak tasarlanmalı ve mekansal bir süreklilikoluşturulmalıdır. Toplumsal açıdan sistem, açık ve yeşil alanların yerleşim yeri hiyerarşisine vetoplumsal gereksinime göre dağılımı ile ilgilidir. Zamansal açıdan sistem ise açık ve yeşil alanlarıntarihsel sürekliliğinin sağlanması ve geliştirilmesi ile oluşmaktadır. Kayseri Kenti’nde açık ve yeşilalanların mekansal sürekliliği sağlanmamıştır. Kent bütünü ölçeğinde ise kentin yakın çevresinde açıkve yeşil alan sistemi oluşumu açısından önemli alanlar mevcuttur. Fakat bu alanlar kentsel gelişimintehdidi altındadırlar. Planlama ve uygulamaya koruma ağırlıklı yaklaşım ile kentin açık ve yeşilalanlarında zamansal süreklilik sağlanabilir. Konu toplumsal açıdan ele alındığında ise kentte farklıölçeklerde gereksinim duyulan açık ve yeşil alanların yetersiz olduğu görülür. Alınacak bir dizi önlemile Kayseri kent bütününde bir açık ve yeşil alan sistemi oluşumu sağlanabilir. Bu anlayışla araştırmanınsonucunda kent halkına etkili bir kullanım sunmak üzere neler yapılabileceği konusunda önerilergeliştirilmiştir
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