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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 Parçacık süzgeçleme ile hedef izleme uygulamasında topak çizelgeleme(IEEE, 2007) Özfidan, Özgür; Bayazıt, Uluğ; Çırpan, Hakan AliBu çalışmada, uzaklık ölçer algılayıcılarla hedef takibi uygulamasında algılayıcı çizelgeleme problemi ele alınmıştır. Çok algılayıcılı uygulamalarda algılayıcıların yönetimi ürettikleri verilerin sınıflandırılması için olduğu kadar algılayıcıların verimli kullanımı için de gereklidir. Algılayıcı yönetimindeki önemli hususlardan biri algılayıcı çizelgelemesidir. Algılayıcıları çizelgeleyerek bant genişliği, güç, ve hesaplamada ciddi ölçüde kazanımlar sağlanabilir.Yayın Optimal investment levels to eliminate inventory inaccuracy in a two-level supply chain(Istanbul Technical Univ, 2007) Uçkun, Canan; Karaesmen, Ahmet Fikri; Savaş, SelçukInventory inaccuracy is a major problem in supply chains. RFID technology is anticipated to alleviate this problem at the expense of the required hardware and software investment. For a supply chain consisting of single supplier and multiple warehouses, we investigate the optimal levels of investment in order to decrease inventory inaccuracy. The analysis yields in-sights on the relative benefits of RFID implementation depending on factors such as demand and inaccuracy variability, financial parameters and supply chain structure.Yayın Dilemma of the HR manager: An optimization for training and development budgets using integer programming a case study from an international firm(Int Inst Informatics & Systemics, 2005) Yanık, Serhat; Yazıcı, Selim; Şenel, İlhan KeremThis paper is about a dilemma of an HR manager of an international company. The major problem of HR managers is to minimize their training and development budgets. Making a training budget is not so complex; but the important, yet often neglected, part of budgeting is the costs of absence of employees. In every kind of training, whether traditional or e-learning, there is a cost for the time being spent away from work. Some of the managers think that this is an idle time for company, plus the employee is paid during this period. This paper focuses on the costs of the absence and their effect on training budgets. Some scenarios were developed with the help of an HR manager of an international firm. The feasibility of these scenarios was studied by using integer programming.Yayın Cluster based sensor scheduling in a target tracking application with particle filtering(IEEE, 2007) Özfidan, Özgür; Bayazıt, Uluğ; Çırpan, Hakan AliIn multi-sensor applications management of sensors is necessary for the classification of data they produce and for the efficient use of sensors as well. One of the important aspects in sensor management is the sensor scheduling. By scheduling the sensors, serious reductions can be achieved in the cost of bandwidth, power, and computation. In this work a simple solution for the problem of sensor scheduling in a multi-sensor target tracking application is presented. Due to non-linearity of the problem itself, proposed solution is presented in the framework of non-linear Bayesian estimation.Yayın An integrated circuit with transmit beamforming and parallel receive channels for 3D ultrasound imaging: testing and characterization(IEEE, 2007) Wygant, Ira O.; Jamal, Nafis S.; Lee, Hyunjoo J.; Nikoozadeh, Amin; Zhuang, Xuefeng; Oralkan, Ömer; Ergün, Arif Sanlı; Karaman, Mustafa; Khuri-Yakub, Butrus ThomasThe cost and complexity of medical ultrasound imaging systems can be reduced by integrating the transducer array with an integrated circuit (IC). By incorporating some of the system's front-end electronics into an IC, bulky cables and costly system electronics can be eliminated. Here we present an IC for 3D intracavital imaging that requires few electrical connections but uses a large fraction of a 16x16-element 2D transducer array to transmit focused ultrasound. To simplify the receive and data acquisition electronics, only the 32 elements along the array diagonals are used as receivers. The IC provides a preamplifier for each receiving element. Each of the 224 transmitting elements is provided an 8-bit shift register, a comparator, and a 25-V pulser. To transmit, a global counter is incremented from 1 to 224; each pulser fires when its stored register value is equal to the global count value. Electrical testing of the fabricated IC shows that it works as designed. The IC was flip-chip bonded to a two-dimensional capacitive micromachined ultrasonic transducer (CMUT) array. A two-dimensional image of a wire target phantom was acquired.Yayın A bit-serial sum of absolute difference accelerator for variable block size motion estimation of H.264(IEEE, 2009) Fatemi, Mohammad Reza Hosseiny; Ateş, Hasan Fehmi; Salleh, Rosli BinBit-serial architectures offer a number of attractive features over their bit-parallel counterparts such as smaller area cost, lower density interconnection, a reduced number of pins, higher clock frequency, simpler routing and etc. These attractive features make them suitable for using in VLSI design and reduce overall production cost. In this paper, we propose the first least significant bit (LSB) bit-serial sum of absolute difference (SAD) hardware accelerator for integer variable block size motion estimation (VBSME) of H.264. This hardware accelerator is based on a previous state-of-art bit-parallel architecture namely propagate partial SAD. In order to reduce area cost and improve throughput, pixel truncation technique is adopted. Due to the bit-serial pipeline architecture and using small processing elements, our architecture works at much higher clock frequency (at least 4 times) and reduces area cost about 32% compared with its bit-parallel counterpart. The proposed hardware accelerator can be used in different disciplines from low bit rate to high bit rate by making a tradeoff between the degree of parallelism or using fast algorithm or a combination of both.Yayın Mikro ölçekli hisselerde anormal fiyat hareketlerinin LSTM ile tahmini(Institute of Electrical and Electronics Engineers Inc., 2025-08-15) Recal, Füsun; Kayaçetin, Nuri Volkan; Kayahan, İsmailBireysel yatırımcıların karar alma süreçlerinde gözlemlenen aşırı iyimserlik, sürü psikolojisi ve yakın geçmişteki performansa aşırı tepki gibi davranışsal eğilimler dar yatırımcı tabanları ve düşük likiditeleri nedeniyle arbitraj mekanizmasının göreceli olarak zor işlediği mikro ölçekli hisselerin değerlerini makul ekonomik temellerden koparabilir. Bu çalışmada, bu tip davranışsal eğilimlerin hisse fiyatı ve işlem hacmi üzerinde belli örüntüler bırakacağı fikrinden yola çıkılarak, Borsa İstanbul’da işlem gören mikro ölçek hisselerdeki anormal fiyat ayrışmalarını, geçmiş fiyat ve hacim bazlı değişkenler yardımıyla tahmin eden bir LSTM modeli geliştirilmiştir. İncelenen hisselerin yarısından çoğunda modelden elde edilen tahminler gerçekleşen getirilerle pozitif ve istatistiksel olarak anlamlı bir ilişki içindedir. Sonuçlar, mikro ölçekli hisselerdeki fiyat ayrışmalarının geçmiş fiyat ve hacim verisiyle kısmen de olsa açıklanabildiğini göstermektedir.
