Arama Sonuçları

Listeleniyor 1 - 9 / 9
  • Yayın
    A tunable inductance topology to realize frequency tunable matching networks and amplifiers
    (IEEE, 2013) Atilla, Doğu Çağdaş; Aydın, Çağatay; Köprü, Ramazan; Nesimoğlu, Tayfun; Yarman, Bekir Sıddık Binboğa
    Coverage of commercial communication standards such as GSM, UMTS, Wi-Fi and Wi-Max within a single transceiver chip is one of the most desired properties by wireless communication manufacturers. In this regard, communication companies are keenly interested in the design of high power amplifiers for broadband cellular communications to achieve this coverage. In this work, design of broadband tunable matching networks is investigated using Real Frequency Techniques. In practical applications, tunability is needed to compensate for the load impedance variations with environmental effects. In order to be able to work on sample structures, impedance transforming filters with proper topology are chosen and a broadband tunable matching network with a tunability strategy is developed. Eventually a broadband amplifier has been designed using the tunable inductor concept.
  • Yayın
    Soft decision trees
    (IEEE, 2012) İrsoy, Ozan; Yıldız, Olcay Taner; Alpaydın, Ahmet İbrahim Ethem
    We discuss a novel decision tree architecture with soft decisions at the internal nodes where we choose both children with probabilities given by a sigmoid gating function. Our algorithm is incremental where new nodes are added when needed and parameters are learned using gradient-descent. We visualize the soft tree fit on a toy data set and then compare it with the canonical, hard decision tree over ten regression and classification data sets. Our proposed model has significantly higher accuracy using fewer nodes.
  • Yayın
    Budding trees
    (IEEE Computer Soc, 2014-08-24) İrsoy, Ozan; Yıldız, Olcay Taner; Alpaydın, Ahmet İbrahim Ethem
    We propose a new decision tree model, named the budding tree, where a node can be both a leaf and an internal decision node. Each bud node starts as a leaf node, can then grow children, but then later on, if necessary, its children can be pruned. This contrasts with traditional tree construction algorithms that only grows the tree during the training phase, and prunes it in a separate pruning phase. We use a soft tree architecture and show that the tree and its parameters can be trained using gradient-descent. Our experimental results on regression, binary classification, and multi-class classification data sets indicate that our newly proposed model has better performance than traditional trees in terms of accuracy while inducing trees of comparable size.
  • Yayın
    A new speech modeling method: SYMPES
    (IEEE, 2006) Güz, Ümit; Gürkan, Hakan; Yarman, Bekir Sıddık Binboğa
    In this paper, the new method of speech modeling which is called SYMPES is introduced and it is compared with the commercially available methods. It is shown that for the same compression ratio or better, SYMPES yields considerably better hearing quality over the coders such as G.726 at 16 Kbps and voice excited LPC-10E of 2.4Kbps.
  • Yayın
    Design of a third generation real-time cellular neural network emulator
    (IEEE, 2014) Yıldız, Nerhun; Cesur, Evren; Tavşanoğlu, Ahmet Vedat
    In this paper, the features of the next generation Real-Time Cellular Neural Network Processor (RTCNNP-v3) are discussed. The RTCNNP-v2 structure is the only CNN implementation that is reported to be capable of processing full-HD 1080p@60 (1920 x 1080 resolution at 60 Hz frame rate) video images in real-time, due to its fully-pipelined architecture, however, it has some weaknesses like the inability to divide the processing in spatial domain, record and recall intermediate results to an external memory and has some issues in its internal memory coding. Those shortcomings are to be addressed in the next design of our CNN emulator - RTCNNP-v3, which will increase the range of applications and enable the implementation to match the requirements of the cutting-edge movie production technologies like UHD (4K) and the future FUHD (8K).
  • Yayın
    Programlamaya giriş dersi öğrencilerinin öz yeterlilik algıları ve derse yönelik tutumlarının cinsiyet ve eğitim diline göre incelenmesi
    (IEEE, 2017-10-31) Deveci, Ezgi; Aydın, Damla; Benli, Kristin Surpuhi; Tek, Faik Boray
    Bu araştırmanın amacı F.M.V. Işık Üniversitesi Mühendislik Fakültesinde öğrenim gören öğrencilerin genel öz-yeterlilik algılarının ve Programlamaya Giriş(CSE101) dersine yönelik tutumlarının; cinsiyet ve eğitim aldıkları programın diline (Türkçe-İngilizce) göre incelenmesidir. Araştırmaya 40 kadın ve 74 erkek olmak üzere toplam 114 üniversite öğrencisi katılmıştır. Öğrencilerin öz yeterlilik algılarını ölçmek için Genel Öz Yeterlilik ölçeği kullanılmış, ders sonucunu (başarı ve başarısızlık) değerlendirmeleri için açık uçlu sorular sorulmuş ve yaş, cinsiyet gibi temel demografik bilgileri alınmıştır. Açık uçlu sorular niteliksel (kalitatif) analiz yöntemi ile incelenmiştir. Yapılan niceliksel analiz sonucunda öğrencilerin genel öz-yeterlilik puanları ile genel not ortalaması arasında anlamlı, CSE101 dersi dönem sonu not ortalaması arasında ise anlamsız bir ili ki olduğu bulgulanmıştır. Ayrıca öğrencilerin öz-yeterlilik puanlarının cinsiyete ve eğitim aldıkları dile göre (Türkçe-İngilizce) değişmediği görülmüştür. Öğrencilerin motivasyon puanları da eğitim aldıkları dile göre farklılaşmamaktadır. Niteliksel analiz bulgularına göre ise öğrencilerin verdiği cevapların yüzde sıklık değerlerinin cinsiyetleri açısından değiştiği görülmüştür. Bu çalışmanın sonuçları özellikle öğrencilerin derse yönelik tutumlarında cinsiyet açısından bir farklılık olduğunu göstermesi ile mühendislik programlama eğitiminde öğrenci başarısını yordayan değişkenlerin tespit edilmesi sürecine katkı sağlaması beklenmektedir.
  • Yayın
    Complex and real rays in three dimensional Minkowski space
    (IEEE, 2002) Hasanoğlu, Elman
    A new approach to the theory of complex rays is proposed. It is shown that the Minkowski space is more appropriate for describing these rays than the usual, Euclidian spaces. Some illustrative examples are represented.
  • Yayın
    A novel biometric authentication approach using electrocardiogram signals
    (IEEE, 2013) Gürkan, Hakan; Güz, Ümit; Yarman, Bekir Sıddık Binboğa
    In this work, we present a novel biometric authentication approach based on combination of AC/DCT features, MFCC features, and QRS beat information of the ECG signals. The proposed approach is tested on a subset of 30 subjects selected from the PTB database. This subset consists of 13 healthy and 17 non-healthy subjects who have two ECG records. The proposed biometric authentication approach achieves average frame recognition rate of %97.31 on the selected subset. Our experimental results imply that the frame recognition rate of the proposed authentication approach is better than that of ACDCT and MFCC based biometric authentication systems, individually.
  • Yayın
    EEG signal compression based on classified signature and envelope vector sets
    (IEEE Computer Society, 2007) Gürkan, Hakan; Güz, Ümit; Yarman, Bekir Sıddık Binboğa
    In this paper, a novel method to compress ElectroEncephaloGram (EEG) Signal is proposed. The proposed method is based on the generation Classified Signature and Envelope Vector Sets (CSEVS) by using an effective k-means clustering algorithm. In this work on a frame basis, any EEG signal is modeled by multiplying three parameters as called the Classified Signature Vector, Classified Envelope Vector, and Frame-Scaling Coefficient. In this case, EEG signal for each frame is described in terms of the two indices R and K of CSEVS and the frame-scaling coefficient. The proposed method is assessed through the use of root-mean-square error (RMSE) and visual inspection measures. The proposed method achieves good compression ratios with low level reconstruction error while preserving diagnostic information in the reconstructed EEG signal.