Arama Sonuçları

Listeleniyor 1 - 10 / 32
  • Öğe
    Determining relevant features in estimating short-term power load of a small house via feature selection by extreme learning machine
    (IEEE, 2017-11-02) Ertuğrul, Ömer Faruk; Sezgin, Necmettin; Öztekin, Abdulkerim; Tağluk, Mehmet Emin
    Estimating short-term power load is a fundamental issue in the power distribution system. Since short-term power load is related to many parameters such as weather conditions, and time. The aim of this study is to determine the relevant parameters in estimating short-term power load not only in order to decrease the computational cost, but also to achieve higher success rates. Furthermore, by using selected features the required memory, equipment and communication costs are also decreased in real time applications. Feature selection by extreme learning machine method was used in determining relevant features. The short-term power loads of two houses (one of them has a power generation capability) were used in tests and achieved results showed lower error rates were obtained by using less number of features.
  • Öğe
    Grasshopper optimization algorithm for automatic voltage regulator system
    (IEEE, 2018-06-21) Ekinci, Serdar; Hekimoğu, Baran
    A novel design method is presented to determine optimum proportional-integral-derivative (PID) controller parameters of an automatic voltage regulator (AVR) system utilizing the grasshopper optimization algorithm (GOA). The proposed approach is a simple and effective algorithm that is able to solve many optimization problems even those with unknown search spaces effectively. The simplicity of algorithm provides high quality tuning of optimal PID controller parameters. The integral of time weighted squared error (ITSE) is used as the performance index to confirm the performance of the proposed GOA-PID controller. When compared to the other PID controllers based on Ziegler- Nichols (ZN), differential evolution (DE), and artificial bee colony (ABC) tuning methods, the proposed method is found highly effective and robust to improve AVR system's transient response.
  • Öğe
    Organometalik mangan kompleks ince filminin bazı optik özellikleri ve fotovoltaik diyot uygulaması
    (Ubek Yayınevi, 2019-11) Güllü, Ömer; Özaydın, Cihat; Özaydın, Mizgin Tutşi
  • Öğe
    Salp sürüsü algoritması kullanılarak AVR sistemi için PID kontrolör ayarı
    (IEEE, 2019-01-24) Ekinci, Serdar; Hekimoğu, Baran
    Bu makalede salp sürüsü algoritması (SSA) adında yeni bir yapay zekaya dayalı optimizasyon metodu otomatik gerilim regülatörü (AVR) sisteminin en uygun oransal, integral, türevsel (PID) kontrolör parametrelerinin belirlemesi amacıyla kullanılmıştır. Algoritmanın basitliği, optimal PID kontrolör parametrelerinin yüksek kaliteli ayarını sağlar. Kontrolör parametrelerinin optimize edilmesi için zaman ağırlıklı karesel hatanın integrali (ITSE) amaç fonksiyonu olarak seçildi. Geçici hal cevap analizi, SSA metodunun Ziegler-Nichols (ZN) geleneksel ayarlama yönteminden ve yapay arı kolonisi (ABC) algoritmasından daha iyi bir ayarlama kabiliyetine sahip olduğunu ve bir AVR sisteminin basamak cevabını iyileştirmede daha verimli olduğunu ortaya koymuştur.
  • Öğe
    Dalgacık dönüşümü tabanlı parmak izi tanıma
    (IEEE, 2015-06-19) Çalışkan, Abidin; Ertuğrul, Ömer Faruk
    Bir biyometrik sistem, bir bireyin sahip olduğu karakteristik veya eşsiz özniteliğe dayalı olarak otomatik tanımlamayı sağlar. Parmak izi, günümüzde birçok alanda geniş bir kullanım alanına sahip bir biyometrik sistemdir. Özellikle insan kimliğinin doğrulanması ve tespit edilmesinde kullanılan parmak izi, erişim için geleneksel olarak kullanılan yöntemlere göre daha güvenilirdir. Bu çalışmada, Gabor dalgacık dönüşümü tabanlı parmak izi tanıma sistemi gerçekleştirilmiştir. Gri seviye parmak izi imgelerinden dalgacık öznitelikleri çıkarılmıştır. Son olarak, parmak izi imgelerinin tanınmasında k en yakın komşuluk sınıflandırıcısı kullanılmıştır. Önerilen algoritma, PolyU yüksek çözünürlüklü parmak izi veri tabanı görüntüleri üzerinde test edilmiştir. Deneysel sonuçlar, önerilen yöntemin mevcut metotların doğruluğunu arttırabildiğini göstermiştir.
  • Öğe
    Detection and recognition of Turkish license plate characters with image segmentation based correlation method
    (Batman Üniversitesi, 2018) Çalışkan, Abidin; Acar, Emrullah; Orun, Özge
  • Öğe
    I V and C V F characteristics of aniline green N type silicon diode
    (İstanbul University, 2015) Özkan, Samet; Güllü, Ömer; Arsel, İsmail; Özaydın, Cihat; Pakma, Osman; Turut, Abdülmecit
    We have studied the I-V, C-V and C-f characteristics of the Aniline Green (AG)/n-type Si structure. In organic/inorganic semiconductor contact applications, in order to keep the technological difficulties and unknowns to a minimum, silicon is generally chosen as the substrate semiconducting material. In this structure, deposition of organic materials on the inorganic semiconductor can generate large number of interface states at the semiconductor surface that strongly influence the electrical properties of the AG/n-Si structure. The values of the ideality factor, series resistance and barrier height obtained from two methods were compared, and it was seen that there was an agreement with each other. The downward concave curvature of the forward bias current-voltage characteristics at sufficiently large voltages is caused by the presence of the effect of series resistance. Thus, the concavity of the forward bias current-voltage characteristics increases with the increasing series resistance value. The high resistance values have given the high ideality factors. Also, the higher values of capacitance at low frequencies were attributed to the excess capacitance resulting from the interface states in equilibrium with the nSi that can follow the ac signal.
  • Öğe
    Electrical parameters of safranine T N silicon contacts
    (İstanbul University, 2015) Güllü, Ömer; Arsel, İsmail; Özkan, Samet; Özaydın, Cihat; Pakma, Osman; Turut, Abdülmecit
    In this work, it has been investigated current-voltage (I-V) andcapacitance-voltage-frequency (C-V-f) characteristics of the Al/SafranineT(ST)/n-Si structure. The values of the ideality factor, series resistance and barrier height calculated by using different methods were compared. It was seen that there was an agreement with each other. Also, it was seen that the barrier height value for our device was higher than one value of 0.50 eV of conventional Al/n-Si Schottky contact. The change in the barrier height value of the device was ascribed to ST thin layer modifying the effective barrier height by influencing the space charge region of the Si inorganic semiconductor. The downward concave curvature of the forward bias current-voltage characteristics at sufficiently large voltages have been attributed to the effect of series resistance. Thus, the concavity of the forward bias current-voltage characteristics increases with increasing series resistance value. It has been seen that the values of capacitance are almost independent to a certain value of frequency, after this value, the capacitance decreases with increasing frequency. The higher values of capacitance at low frequencies have been attributed to the excess capacitance resulting from the interface states in equilibrium with the n-Silicon that could follow the alternating current signal.
  • Öğe
    Multi-feature extraction and multi-classification techniques with computer aided breast cancer detection
    (Batman Üniversitesi, 2018) Çalışkan, Abidin; Acar, Emrullah; Budak, Cafer