Makale Koleksiyonu

Bu koleksiyon için kalıcı URI

https://hdl.handle.net/20.500.12587/8389

Listeleniyor 1 - 20 / 91

Optimizing Energy Hub System Operation With Electrical And Thermal Demand Response Programs
(Konya Teknik Univ, 2024) Akkaş, Özge Pınar; Yıldız, Yağmur Arıkan
Electricity consumption is increasing rapidly and many countries are looking for ways to cope with the energy crisis. Morever, the world is facing the problem of global warming caused by emissions. Therefore, it is of great importance to operate power systems efficiently. Energy Hub (EH) represents a versatile energy system capable of providing efficient and optimal solutions for the operation of power systems across multiple carriers. This paper examines the optimization of an EH encompassing renewable energy systems (RES) like wind and photovoltaic, combined heat and power (CHP), transformer, absorption chiller, energy storage system (ESS) and furnace with aiming at minimizing the cost. Demand response is an energy sector strategy that entails modifying electricity consumption patterns in reaction to fluctuations in electricity supply or pricing. The objective of demand response programs (DRP) is to curtail or shift electricity consumption during periods of elevated electricity prices. Therefore, Electrical Demand Response Program (EDRP) for electrical demand and the Thermal Demand Response Program (TDRP) for heating demand are incorporated into the EH. The optimization problem is formulated as Mixed Integer Linear Programming (MILP) and solved with CPLEX solver in GAMS. The outcomes of various case studies are compared to ascertain the model's efficiency.
Yüz ifade analizinde öznitelik seçimi ve çoklu SVM sınıflandırıcılarına etkisi
(2009) Güneş, Turan; Polat, Ediz
Yüz ifadeleri, insan ilişkilerinde anlam bütünlüğünün sağlanması için büyük rol oynayan, sözlü olmayan işaretlerdir. İnsanoğlu yüz ifadelerini kavramada herhangi bir zorluk çekmezken, bu durum makineler için geçerli olmayıp, halen güvenilir ifade tanıma sistemleri üzerinde araştırmalar yapılmaktadır. Bu çalışmada, insanın içinde bulunabileceği 7 ifade durumunun (öfke, iğrenme, korku, mutluluk, ifadesizlik, üzüntü ve şaşkınlık) analizi gerçekleştirilmiştir. Bu amaçla, her bir ifade için alınan sabit görüntülerin öznitelikleri Gabor filtreleri kullanılarak çıkartılmış ve farklı öznitelik seçme algoritmaları kullanılarak ifadeleri temsil eden en iyi öznitelik kümeleri oluşturulmuştur. Seçilen öznitelik kümelerinin çoklu SVM (Support Vector Machines-Destek Vektör Makineleri) sınıflandırıcıları üzerindeki etkileri incelenmiş ve sınıflandırma doğruluklarının kullanılan öznitelik seçme algoritmalarına göre nasıl değiştiği karşılaştırmalı olarak değerlendirilmiştir. Çoklu sınıflandırma yapılması amacıyla SVM, One-Vs-One, One-Vs-Rest ve MC-SVM olmak üzere 3 farklı yaklaşım ile birlikte kullanılmıştır. Ayrıca öznitelik seçimi yapılmadan alınan sınıflandırma başarım sonuçları da incelendiğinde, öznitelik seçiminin sınıflandırma doğruluğunun artması yönünde genel olarak büyük etkisinin olduğu görülmüştür.
A Study of Energy Efficiency in Rail Vehicles
(2020) Arıkan, Yağmur; Şen, Tolga Altuğ; Çam, Ertuğrul
Today, rail vehicles are frequently preferred both in urban and intercity transportation due to their high passenger capacity, speed and increasing environmental awareness. As in every field, energy efficiency studies have become compulsory in these vehicles. Because, they have high energy consumption even in their daily services. For energy efficiency, there are various strategies such as electrification losses reduction, utilization of regenerative braking and improvement of comfort function and efficient driving techniques have been performed in this paper. For this purpose, firstly, the driving of a rail vehicle has been modeled on Matlab considering all vehicle information, track information and operational constraints. Then, four different driving styles have been determined for the efficient use of energy and their effects on travel time and energy consumption have been examined. The study has been tested with the practical data of Ankaray metro line which has eleven stations and is 8.527 km long. According to the results of the paper, coasting control is more effective for long distances and reduction of the maximum speed is more convenient for short distances. Furthermore, it has been demonstrated that thanks to the determined strategies, the vehicle can save up to 11.54-36.37% energy compared to practical driving.
Analysis of the Studies on E-learning Acceptance of Learners in the Middle East and the Proposal of an Extended Technology Acceptance Model
(2020) Baki, Rahmi; Birgören, Burak
E-learning applications can result in various expectations, attitudes and needs based on the users’ geographical regions and cultural roots, therefore, design of e-learning systems by taking into account the individuals’ cultural and demographic attributes is crucial for an effective learning environment. This study considers 44 researches that assess users’ e-learning acceptance characteristics in 10 different Middle Eastern countries, where 45 external variables are proposed as predeterminants of Perceived Usefulness (PU) and Perceived Ease of Use (PEOU), both of which are Technology Acceptance Model’s (TAM) belief components. 75 hypotheses are tested 155 times where these external variables are presented to be the antecedents of the belief components. With the help of a region-based literature review; it is aimed to identify the factors causing users’ system acceptance in the Middle East. As a result, an extended TAM is proposed for the Middle East by incorporating the most frequently accepted hypotheses into the original TAM.
Ateş böceği algoritması kullanarak MC-CDMA sistemlerinde çevrimsel ön takı uzunluğunun belirlenmesi
(2017) Seyman, Muhammet Nuri
Çok taşıyıcılı kod bölmeli çoklu erişim gibi yüksek hızlarda veri iletimini sağlayan çok taşıyıcılı haberleşme sistemlerinde semboller arası girişim ve kanallar arası girişimi önlemek için çevrimsel ön takıdan faydalanılır. Bu yüzden çevrimsel ön takı uzunluğunun uygun bir şekilde belirlenmesi, sadece hata performansını artırmayacak aynı zamanda da sembol enerjisindeki azaltmaları da engelleyecektir. Bu çalışmada çevrimsel ön takı uzunluklarının belirlenmesi için yeni bir meta-sezgisel algoritma olan ateş böceği algoritması önerilmiştir. Önerilen bu algoritmayı kullanarak, Genetik Algoritmalar ve 1/8 oranlı çevrimsel ön takı kod uzunluklu sistemlere göre daha iyi bit hata oranları elde edilmiştir. Parametre sayısının az ve performansının Genetik Algoritmalara göre yüksek olması nedeniyle bu algoritma çok taşıyıcılı kod bölmeli çoklu erişim sistemlerinde çevrimsel ön takı boyutlarının adaptif olarak belirlenmesinde kullanılabilir
Filled fonksiyon kullanarak vana etkili ekonomik yük dağıtımı probleminin çözülmesi
(2017) Eke, İbrahim; Tezcan, Süleyman Sungur; Çelik, Coşkun
Bu makalede, ekonomik yük dağıtımı problemine filled fonksiyonu metodu uygulanmıştır. Vana etkisi gibidoğrusal olmayan durumlar içeren ekonomik yük dağıtımı probleminin çözümünde önerilen methodunbaşarısı gösterilmiştir. Eşitlik ve eşitsizlik içeren üç farklı test durumunda, önerilen metot test edilerekdoğrulanmıştır. Elde edilen benzetim sonuçlarına göre; filled fonksiyon metodu, parametrelerin ilkdeğerlerine daha az bağlıdır ve geliştirilen diğer algoritmalara göre daha verimli çalışmaktadır. Bunlara ilavaten, büyük güç sistemlerinde önerilen algoritmanın kolaylıkla uygulanabileceği öngörülmektedir.
Kalıcı mıknatıslı senkron jeneratörlü rüzgâr türbinlerinde bireysel hatve açısı kontrolü ile çıkış gücü kararlılığı ve mekanik yüklerin azaltılması
(2017) Lüy, Murat; Civelek, Zafer; Cam, Ertuğrul
Bu makalede rüzgâr türbinlerinin çıkış gücü kalitesinin arttırılması ve türbin üzerindeki mekanik yüklerin hafifletilmesi üzerine bir çalışma yapılmıştır. Nominal rüzgâr hızlarının üzerinde kanat hatve açısı ayarlanarak rüzgâr türbininin çıkış gücü nominal değerde tutulmuştur. Ayrıca bireysel hatve açısı kontrolü ile de rüzgâr türbini üzerindeki mekanik yükler azaltılmıştır. Kalıcı mıknatıslı senkron jeneratör modellenmiştir. Simülasyon sonuçları, bireysel hatve açısı kontrolü ile rüzgâr türbininin hem çıkış gücü kalitesinin sağlandığını hem de rüzgâr türbini üzerindeki dengeli periyodik yüklerin azaltıldığını göstermiştir
Rüzgar ve Güneş Enerjisi Sistemlerinin Fizibilite Analizlerinin Web Tabanında Gerçekleştirilmesi
(2017) Arıkan, Yağmur; Çam, Ertuğrul
Bu çalışmada, rüzgâr ve güneş enerji sistemlerinin potansiyel, enerji üretimi ve ekonomik analizlerini yapmak için web tabanında bir yazılım hazırlanmıştır. Programda, örnek uygulama bölgesi olarak Amasra seçilmiştir. Bölgenin saatlik rüzgâr hızı verileri, Rayleigh istatistiksel yöntemi kullanılarak detaylı olarak incelenmiştir. Potansiyelin yatırım için uygunluğu görüldükten sonra bölgeye 600 kW'lik bir rüzgâr türbini kurulduğu takdirde bölgeden üretilecek rüzgar enerji üretimi, türbinin kapasite faktörü, yatırımın geri ödeme süresi ve kar miktarı bulunmuştur. Üretilen temiz enerjinin çevreye katkıları sayısal olarak gösterilmiştir. Çalışmanın diğer kısmında, bölgenin aylık güneşlenme süreleri kullanılarak bölgeye 100 kWp kurulu güce sahip güneş paneli kurulduğu takdirde sistemden üretilecek güneş enerji üretim miktarı, yatırımın geri ödeme süresi ve kar miktarı bulunmuştur. Çalışmanın son kısmında, rüzgâr enerjisi ve güneş enerjisi verileri birleştirilerek, bölgeye hibrit enerji sistemleri kurulduğu takdirde, çeşitli senaryolar irdelenerek, üretilen enerji miktarları hesaplanmış ve yatırımın ekonomik analizi yapılmıştır. Bütün analizlerden elde edilen sonuçlara göre, hangi durumun bölge ve yatırımcı için daha kârlı olduğu araştırılmıştır
Effects of Zero Velocity Update on Total Displacement for Indoor Inertial Positioning Systems
(2017) Ulamış, Faruk; Lüy, Murat; Çam, Ertuğrul; Uzun, İbrahim
In this paper; the effects of Zero Velocity Update method, which is one of the most important components of indoor inertial positioning systems, on total displacement is studied. For this purpose, acceleration and angular velocity measurements on three-axes are obtained by a low-cost foot-mounted inertial measurement unit while walking. The obtained acceleration values are processed and velocity and total displacement are estimated by using double integration. Velocity and displacement estimations were done at the end of each step with and without ZUPT algorithm and the results have been compared. Furthermore, in order to understand ZUPT algorithm well, a rectangular shape is plotted with the system containing IMU and microprocessor by stopping at every corner. ZUPT algorithm is implemented at each stop on the corners of the rectangular shape. The results are plotted in MATLAB. Effects of the errors on total displacement are pointed out
Optimization of pilot tones using differential evolution algorithm in MIMO-OFDM systems
(2012) Seyman, Muhammet Nuri; Taşpınar, Necmi
In this paper, we propose a differential evolution (DE) algorithm for optimizing the placement and power of the pilot tones that are utilized by a least square (LS) algorithm for channel estimation in multipleinput and multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) systems. Computer simulations demonstrated that the performance of the LS algorithm was increased by optimizing the pilot tones with the DE algorithm instead of locating them orthogonally. We used the upper bound of the mean square error (MSE) as a fitness function of the DE algorithm for optimization tasks. With the use of an upper bound, it is not necessary to compute the matrix inversion that is needed in computing the MSE.
Optimal operational scheduling of a virtual power plant participating in day-ahead market with consideration of emission and battery degradation cost
(WILEY, 2020) Akkas, Ozge P.; Cam, Ertugrul
In this article, optimal operation of a virtual power plant (VPP) composed of a wind power plant, a photovoltaic power plant, a combined heat and power plant, a heat-only unit, and battery energy storage system is analyzed for day-ahead market. The aim is to adjust the entire generation system for maximum profit and minimum emissions to ensure that the future of the world is clean and investors are not harmed. For these reasons, data obtained from studies in the literature are used in a 24-hour time period. In addition to the four application cases of VPPs, which are mostly discussed in the literature, a fifth case has been proposed in order to be more realistic. All cases and models are modeled and analyzed in the General Algebraic Modeling System (GAMS) software by using the LINDO solver, which has not been used before in previous studies for this problem. Also, battery degradation cost and effects of depth of discharge and temperature are included in the objective function of the VPP model both to provide reality and observe their effects. As a result of this study, it has been shown that the profit of the VPP can be increased while the emission is reduced.
The Adaptive Chaotic Symbiotic Organisms Search Algorithm Proposal for Optimal Reactive Power Dispatch Problem in Power Systems
(Istanbul Univ-Cerrahapasa, 2019) Yalcin, Enes; Taplamacioglu, M. Cengiz; Cam, Ertuogrul
This paper presents an adaptive chaotic symbiotic organisms search algorithm (A-CSOS) for finding the solution of optimal reactive power dispatch (ORPD) problem which is one of the main issues of power system planning and operations. The most important advantage of symbiotic organisms search algorithm (SOS) is that is not need any particular algorithm parameters. However, the SOS algorithm has some features to be enhanced, like falling into local minima and sluggish convergence. A-CSOS algorithm with adding new and improved features like adaptivity and chaos to conventional SOS algorithm is proposed to solve ORPD problem. The ORPD problem is mainly focused on minimization of transmission loss (Ploss) and total voltage deviation (TVD). To determine the optimal set points of control variables including generator bus voltages, tap positions of transformers, and reactive power outputs of shunt VAR compensators is very crucial for minimization to Ploss and TVD. The proposed algorithm is implemented on IEEE 30-bus test power systems for ascertaining the performance of A-CSOS algorithm on ORPD problem. The results showed that the proposed approach is up to 10.39% better than many of which the latest algorithms in literature and encourage the researchers to implement A-CSOS algorithm to ORPD problem.
Model Parameters of Electric Motors for Desired Operating Conditions
(Univ Suceava, Fac Electrical Eng, 2019) Sevinc, Ata
Researchers dealing with electric motor control simulations need motor parameters for some desired operating conditions. Despite such an obvious need, no algorithm yielding motor parameters can be found even for the basic set of desired "voltage, output power, speed and efficiency" in the literature. A lot of electric motor design methods exist; but all give the physical design parameters for manufacturing such as numbers and dimensions of slots, magnets and turns. They are usually based on design requirements that only experienced people can understand and the mentioned basic demand set is not completely included among them. This article covers the deficiency of the algorithms giving all the model parameters required for the control simulations for dc servo, induction, and synchronous motors according to simple design requirements that an inexperienced researcher can easily understand. A transformer design algorithm is also included. The induction motor and salient-pole synchronous motor algorithms are the main contributions. The propositions can be used even if the demands are given for generator mode with some care. These algorithms may also be considered as another kind of design and they may help to reduce physical designs to lower-level steps according to simple design requirements.
A depth perception evaluation metric for immersive user experience towards 3D multimedia services
(Springer, 2019) Bayrak, Huseyin; Yilmaz, Gokce Nur
The interest of users towards three-dimensional (3D) video is gaining momentum due to the recent breakthroughs in 3D video entertainment, education, network, etc. technologies. In order to speed up the advancement of these technologies, monitoring quality of experience of the 3D video, which focuses on end user's point of view rather than service-oriented provisions, becomes a central concept among the researchers. Thanks to the stereoscopic viewing ability of human visual system (HVS), the depth perception evaluation of the 3D video can be considered as one of the most critical parts of this central concept. Due to the lack of efficiently and widely utilized objective metrics in literature, the depth perception assessment can currently only be ensured by cost and time-wise troublesome subjective measurements. Therefore, a no-reference objective metric, which is highly effective especially for on the fly depth perception assessment, is developed in this paper. Three proposed algorithms (i.e., Z direction motion, structural average depth and depth deviation) significant for the HVS to perceive the depth of the 3D video are integrated together while developing the proposed metric. Considering the outcomes of the proposed metric, it can be clearly stated that the provision of better 3D video experience to the end users can be accelerated in a timely fashion for the Future Internet multimedia services.
An Electric Taxi Charging Station Planning Scheme Based on an Improved Destination Choice Method
(Mdpi, 2019) Shi, Ruifeng; Liu, Jiahua; Liao, Zhenhong; Niu, Li; Ibrahim, Eke; Fu, Fang
The environmental crisis has prompted the development of electric vehicles as a green and environmentally friendly mode of travel. Since a reasonable layout of electric vehicle (EV) charging stations is the prerequisite for developing the EV industry, obtaining an optimal and efficient EV charging station planning scheme is a key issue. Although the Chinese government has carried out a plan to build EV charging piles in residential and working places, it cannot properly fulfill the task of matching the charging needs for public transportation vehicles such as electric taxis (ETs). How to evaluate the performance of fast charging stations (FCSs) and how to help find the optimal ET charging station planning scheme are new challenges. In this paper, an improved destination selection model is proposed to simulate the ET operation system and to help find the optimal ET charging station size with statistical analysis based on the charging need prediction. A numerical case study shows that the proposed method can address ET charging behavior well and can help to statistically determine the size of each ET charging station, which should satisfy the constraints on the preset proportion of the ET charging service requests.
A novel depth perception prediction metric for advanced multimedia applications
(Springer, 2019) Yilmaz, Gokce Nur
Ubiquitous multimedia applications diffuse our everyday life activities which appreciate their significance about improving our experiences. Therefore, proliferation of the multimedia applications enhancing these experiences needs critical attention of the researchers. Considering this motivation, to overcome the possible barrier of the proliferation of the 3D video-related multimedia applications providing enhanced quality of experience (QoE) to the end users, an objective metric is proposed in this study. The proposed metric tackles the depth perception prediction part reflecting the most important aspect of the 3D video QoE from the user point of view. Considering that the no reference metric type is the most effective one compared to its counterparts, the proposed metric is developed based on this type. In the light of the envision that human visual system-related cues have critical importance on developing accurate metrics, the focus of the proposed metric is directed on the association of the z-direction motion and stereopsis depth cues in the metric development. These cues are derived from the depth map contents having stressed significant depth levels. In addition, the analysis results of the conducted subjective experiments which are currently the "gold standards" for the reliable depth perception prediction are incorporated with the proposed metric. Considering the effective correlation coefficient and root mean square error performance assessment results taken using the proposed metric in comparison to the widely exploited quality assessment metrics in literature, it can be clearly stated that the development of the improved 3D video multimedia applications can be accelerated using it.
A Robust PID Power System Stabilizer Design of Single Machine Infinite Bus System using Firefly Algorithm
(Gazi Univ, 2018) Farhad, Zakirhussain; Eke, Ibrahim; Tezcan, Suleyman Sungur; Safi, Shah Jahan
This paper presents the design of a proportional-integral-derivative power-system-stabilizer using the firefly algorithm for tuning of stabilizer parameters and washout (reset). The proposed optimization of parameters is carried out with eigenvalue analysis based objective function for two cases (two parametric bounds) to guarantee the stability for the single-machine-infinite-bus system model for a wide range of operating conditions. The system performance with Firefly-Algorithm tuned controller is compared with Bat-Algorithm optimized Conventional-Power-System-Stabilizer controller. The power system robustness is tested on 133 operating conditions to set up the superior performance of FA-PID-PSS over the BA-CPSS. According to the eigenvalue analysis and time response parameters results, it is found that BA-CPSS and FA-PID-PSS (case-I) have the ability to stabilize the system for some operating conditions; but the FA-PID-PSS (case-II) can stabilize the system and can improve settling time and overshoot for all operating conditions.
Gravitational Search Algorithm (GSA) Based PID Controller Design for Two Area Multi-Source Power System Load Frequency Control (LFC)
(Gazi Univ, 2018) Safi, Shah Jahan; Tezcan, Suleyman Sungur; Eke, Ibrahim; Farhad, Zakirhussain
This paper presents the design and performance analysis of a meta-heuristic search technique (Gravitational-Search-algorithm) for optimal tuning of Proportional-Integral-Derivative plus Filter (PIDF) controller for automatic generation control of multi-source two area interconnected power system. Integral of absolute magnitude of square of error (IASE) is used as objective function. Excellency of the proposed approach is shown with comparison of differential evolution and particle swarm optimization algorithm. The dynamic response has been studied under variety of operating-conditions. The simulation results by MATLAB/Simulink program represent that the tuned PIDF-controllers by gravitational search algorithm supply the better damping of oscillations in power system.
New Optimization Algorithms for Application to Environmental Economic Load Dispatch in Power Systems
(Istanbul Univ, Fac Engineering, 2018) Akkas, Ozge Pinar; Cam, Ertugrul; Eke, Ibrahim; Arikan, Yagmur
The determination of the most economical generation dispatch in an electrical power system has become a very important issue globally. However, economical dispatch can no longer be considered alone because of environmental problems that are derived from emissions such as nitrogen oxide, carbon dioxide, and sulfur dioxide. In this study, the problem of environmental economic load dispatch (EELD) in a power system of six generators is addressed both by neglecting and including line transmission losses using a modified genetic algorithm and a modified artificial bee colony optimization method. The results of these modified algorithms are compared with those of the unmodified versions. The results demonstrate that the proposed new methods have better economic and environmental distribution performances. Accordingly, it can be concluded that the new methods are more effective and should be adopted.
Initial Results of Testing a Multilayer Laser Scanner in a Collision Avoidance System for Light Rail Vehicles
(Mdpi, 2018) Luy, Murat; Cam, Ertugrul; Ulamis, Faruk; Uzun, Ibrahim; Akin, Salih Ibrahim
This paper presents an application to detect and track obstacles using a multilayer laser scanner. The goal of the detection system is to develop collision avoidance for the Light Rail Vehicle (LRV). The laser scanner, which is mounted in front of the tram, collects information in a four-scan plane. The object recognition and tracking module, which is composed of a three sub-modules segmentation, classification, and Kalman Filter tracking, was carried out on the raw data. Thus, data were provided for collision avoidance module. The proposed system was applied to a tram named "Silkworm" which is manufactured by Durmazlar Machine Inc. (Bursa, Turkey) and initial experimental tests have been conducted at the facilities of Durmazlar Machine Inc. in the city of Bursa, Turkey. This study aims to illustrate parts of the possible tests that can be carried out and to share with the scientific community an important application of multilayer laser scanners, although in the initial implementation phase, in urban rail transportation.

Güncel Gönderiler