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Yayın Calculating the VC-dimension of decision trees(IEEE, 2009) Aslan, Özlem; Yıldız, Olcay Taner; Alpaydın, Ahmet İbrahim EthemWe propose an exhaustive search algorithm that calculates the VC-dimension of univariate decision trees with binary features. The VC-dimension of the univariate decision tree with binary features depends on (i) the VC-dimension values of the left and right subtrees, (ii) the number of inputs, and (iii) the number of nodes in the tree. From a training set of example trees whose VC-dimensions are calculated by exhaustive search, we fit a general regressor to estimate the VC-dimension of any binary tree. These VC-dimension estimates are then used to get VC-generalization bounds for complexity control using SRM in decision trees, i.e., pruning. Our simulation results shows that SRM-pruning using the estimated VC-dimensions finds trees that are as accurate as those pruned using cross-validation.Yayın On the effect of random sampling jitter on cyclostationarity based spectrum sensing algorithms for cognitive radio(IEEE, 2009) Öner, Mustafa MengüçCognitive radio is an enabling technology, which is expected to lead to a more efficient utilization of the available spectral resources due to its flexibility and its ability to sense its spectral environment. Recently, spectrum sensing methods based on exploiting the cyclostationary characteristics of communication signals have been drawing considerable interest. Imperfections in the cognitive radio receiver that affect the cyclic statistics of a signal of interest may lead to a degradation in the performance of spectrum sensing algorithms based on cyclostationarity. One such typical source of imperfection is random timing jitter in the sampling process. In this work, we explore the effect of random sampling jitter on the second order cyclostationary statistics of wide sense cyclostationary signals. General analytical expressions are derived for the cyclic statistics of sampled signals in the presence of sampling jitter and specific results are provided for two cases of interest. Subsequently, the effect of the jitter on a spectrum sensing algorithm is investigated via simulations.Yayın CSR practices in Turkey: Examining CSR reports(Greenleaf Publishing, 2015-07) Uyan Atay, Bilge; Tuncay Çelikel, AslıThis study examines the private companies that publish CSR reports in Turkey. Turkey has a growing economy, located in an international arena with an increasing number of global brands starting to export their products from Turkey with even more multinational enterprises (MNEs) planning to locate in the country. Now, some Turkish companies and subsidiaries of MNEs have started to publish CSR reports. Our findings show that strong Turkish conglomerates are playing a constructive role in macro-level development and governance in Turkey. They are also addressing local problems such as education, human rights, environmental protection and workers' rights. Besides, subsidiaries of MNEs are also having an impact with respect to the application of their headquarters' community programs in Turkish society.Yayın Mülteci barınaklarının uydu görüntülerinden çoklu-sınıflı çizge-kesme bölütleme ve gölge bilgisi kullanılarak otomatik sezimi(IEEE, 2014-04-23) Kucur Ergünay, Şerife Seda; Kahraman, Fatih; Ateş, Hasan FehmiBu çalışmada, mülteci kamplarında bulunan yaşam alanlarının/barınakların (çadır, konteynır vb.) uydu ve hava görüntülerinden otomatik olarak sezimi ve sayımına yönelik bir yöntem tanıtılmaktadır. Mülteci kamplarındaki barınakların çok yüksek çözünürlüklü (VHR) görüntülerde dahi çok küçük boyuta sahip, belli bir alanda çok sık ve bazen karmaşık şekilde yerleştirilmiş ve arkaplan ile ayrıştırılması zor nesnelere denk geliyor olması otomatik barınak/çadır sezim ve sayımını zorlaştırmaktadır. Bahsedilen problemin çözümüne yönelik olarak çok sınıflı çizge-kesme (graph-cut) bölütlemesi ve gölge bilgisinin kullanıldığı özgün bir yöntem çalışma kapsamında önerilmektedir. Buna göre, ilk adımda çizge-kesme bölütleme yöntemi ve morfoloji işlemleri uygulanarak çadır sezimi yapılmıştır. Bu adımda sezilememiş çadırların bulunabilmesi için ikinci bir adımda çadırların gölge bilgisinden faydalanılmıştır. En son adımda gradyan-tabanlı eşikleme yöntemi ile yanlış tespitlerin elenmesi amaçlanmıştır. Önerilen yöntem, özellikle karmaşık yerleşim düzenine sahip mülteci kampları (çadırkent) üzerinde test edilmiştir. Yöntemin başarımı kesinlik (precision) ve geri getirme (recall) kriterlerine göre belirlenmiştir. Elde edilen ortalama kesinlik ve geri getirme başarımları sırasıyla %91.9 ve %90.0 olup problemin zorluğu göz önünde bulundurulduğunda umut vadedici bir sonuçtur.Yayın Phased subarray imaging for low-cost, wideband coherent array imaging(IEEE, 2003) Johnson, Jeremy A.; Oralkan, Ömer; Ergün, Arif Sanlı; Demirci, Utkan; Karaman, Mustafa; Khuri-Yakub, Butrus ThomasThe front-end hardware complexity of conventional full phased array (FPA) imaging is proportional to the number of array elements. Phased subarray (PSA) imaging has been proposed as a method of reducing the hardware complexity-and therefore system cost and size-while achieving near-FPA image quality. A new method is presented for designing the subarray-dependent interpolation filters suitable for wideband PSA imaging. The method was tested experimentally using pulse-echo data of a wire target phantom acquired using a 3.2-cm. 128-element capacitive micromachined ultrasonic transducer (CMUT) array with 85% fractional bandwidth at 3 MHz. A specific PSA configuration using seven 32-element subarrays was compared to FPA imaging, representing a 4-fold reduction in front-end hardware complexity and a 43% decrease in frame rate. For targets near the fixed transmit focal distance, the mean 6-dB lateral resolution was identical to that of FPA, the axial resolution improved by 4%, and the SNR decreased by 5 dB. Measurements were repeated for 10 different PSA configurations with subarray sizes ranging from 4 to 60. The lateral and axial resolutions did not vary significantly with subarray size; both the SNR and contrast-to-noise ratio (CNR) improved with increased subarray size.Yayın 21.yüzyıl çağdaş sanat önermesi olarak Peter Greenaway’in Last Supper dijital video enstalasyonu(Istanbul Univ, Research Inst Turkology, Dept Art History, 2018) Avcı Tuğal, Sibel20.yüzyılda ilk örnekleri görülen dijital teknoloji ve dijital görüntü uygulamaları 21.yüzyılla birlikte post-dijital döneme evrilmiştir. Hızla gelişen dijital görüntüleme teknolojisi ve buna bağlı gelişen dijital video ve dijital görüntü işleme teknolojileri farklı ve yeni anlam katmanları yaratmak üzere sanat alanında kullanılmaktadır. Simülasyonlarla çevrili bir yaşam alanı sunan 21. yüzyılda sanat yeniden varlığını sorgulamaktadır. İngiliz sinema yönetmeni, ressam Peter Greenaway sanatın, özellikle sinema sanatının yenilenmesi ve farklı açılımlar yapabilmesi için 8000 yıllık geçmişi olan resim sanatına yeniden bakılması gerektiğini düşünmektedir. Bu amaçla 2006 yılında, Batı Resim Sanatı’nda başyapıt olarak kabul edilen eserler üzerinde yeni bir görsel bir dil oluşturmak, farklı anlam katmanları yaratmak amacı ile “Nine Classic Paintings Revisited” projesine başlamıştır. Bu proje kapsamında yer alan başyapıtlardan biri Leonardo da Vinci’ye ait “Last Supper” freskidir. Greenaway’in bakışı ile “Last Supper” dijital video enstelasyonu makalede incelenmek üzere seçilmiştir.Yayın A global optimal control methodology and its application to a mobile robot model(Elsevier B.V., 2016) Dinçmen, ErkinA global optimal control algorithm is developed and applied to an omni-directional mobile robot model. The aim is to search and find the most intense signal source among other signal sources in the operation region of the robot. In other words, the control problem is to find the global extremum point when there are local extremas. The locations of the signal sources are unknown and it is assumed that the signal magnitudes are maximum at the sources and their magnitudes are decreasing away from the sources. The distribution characteristics of the signals are unknown, i.e. the gradients of the signal distribution functions are unknown. The control algorithm also doesn't need any position measurement of the robot itself. Only the signal magnitude should be measured via a sensor mounted on the robot. The simulation study shows the performance of the controller.Yayın Placing STS in and through Turkey(Soc Social Studies Science, 2023-03-02) Alkan, Aybike; Kaşdoğan, Duygu; Maral, ErolWhy and how does it matter to undertake an STS praxis in a country where the field lacks adequate institutional recognition and capacity? This article investigates this question by tracing multiple, fragmented and contingent stories of placing STS in and through Turkey. At first sight, discontinuous stories of STS programs established in universities and unrecognized nature of STS as a discipline by the Council of Higher Education draw attention to the "underdeveloped" nature of the field in this country. This article counters such a perspective by rendering visible the works that support STS ethos as well as loose institutions within which STS is expected to flourish. By following people and artifacts in institutional and more-than institutional places of STS, this article acknowledges the efforts both to translate STS into the particular places of Turkey and to use STS as an intellectual space through which technoscientific knowledge can be questioned and translated into the local contexts of the country. The analysis of these translation efforts reveals that STS can be thought of as a space that enables one to be attuned to the sensibilities and realities of the country and search for ways to democratize the processes of technoscientific knowledge production whether it be in the universities or in public spaces.Yayın A New speech coding algorithm using zero cross and phoneme based SYMPES(IEEE, 2013-07-11) Şişman, Burak; Güz, Ümit; Gürkan, Hakan; Yarman, Bekir Sıddık BinboğaIn this work, a new low bit rate hybrid speech coding approach which combines the benefits of the SYMPES (Systematic Procedure for Predefined Envelope and Signature Sequences) and zero cross and phoneme based segmentation is proposed. In the new approach, the SYMPES structure is developed in the phoneme based fashion. In order to achieve lower bit rates, some drawbacks such as computational complexity, relatively high encoding times etc. of the SYMPES are also eliminated in the new version. Experimental results show that in almost same bit rates very promising speech quality is obtained compared to the other conventional methods such as CELP (Code Excited Linear Predictive) coding algorithm.Yayın Deleuze ve Spinoza kavramları üzerinden Kardelen Fincancı, Nezaket Ekici ve Tunç Ali Çam’ın çalışmalarının değerlendirilmesi(Istanbul Kultur Univ, 2017-07) Demir, Vesime ItırBu araştırmada, Benedictus de Spinoza ve Gilles Deleuze’ün sunduğu kavramlar üzerinden performans sanatı örnekleri incelenecektir. İki düşünürün ortaya koyduğu beden odaklı düşüncelerden yola çıkılarak, performans sanatının gündelik yaşamla ilişkisi, izleyiciyle kurduğu ilişki, izleyici ile sanatçının etkileşimi ve yapılan performansın nihayetinde hedefine ulaşıp ulaşmadığı belirlenecektir. Nezaket Ekici’nin “Imagine”, Kardelen Fincancı’nın “Make Me Whole Again” ve Tunç Ali Çam’ın “Yersiz yurtsuzlaşma, Kurşun Kalemler, Karton Kutu ve Ses” adlı performansları izleyiciyle kurduğu ilişkiler ve izleyici üzerinde yarattığı etkiler üzerinden değerlendirilecektir.
