Özdemir, Serpil
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Name Variants
Özdemir, Serpil
S.,Özdemir
S. Özdemir
Serpil, Özdemir
Ozdemir, Serpil
S.,Ozdemir
S. Ozdemir
Serpil, Ozdemir
Ozdemir, Nurten Karacan
Ozdemir, Salih C.
Özdemir, Aydoğan
Özdemir, Zeynep
Ozdemir, Mehmet Akif
S.,Özdemir
S. Özdemir
Serpil, Özdemir
Ozdemir, Serpil
S.,Ozdemir
S. Ozdemir
Serpil, Ozdemir
Ozdemir, Nurten Karacan
Ozdemir, Salih C.
Özdemir, Aydoğan
Özdemir, Zeynep
Ozdemir, Mehmet Akif
Job Title
Öğr. Gör.
Email Address
Serpıl.ozdemır@khas.edu.tr
Main Affiliation
Advertising
Status
Former Staff
Website
ORCID ID
Scopus Author ID
Turkish CoHE Profile ID
Google Scholar ID
WoS Researcher ID
Scholarly Output
17
Articles
6
Citation Count
0
Supervised Theses
1
16 results
Scholarly Output Search Results
Now showing 1 - 10 of 16
Conference Object Citation - WoS: 0Citation - Scopus: 4Impacts of Load and Generation Volatilities on the Voltage Profiles Improved by Distributed Energy Resources(Institute of Electrical and Electronics Engineers Inc., 2020) Ahmedi, Bahman; Ceylan, Oğuzhan; Ceylan, Oğuzhan; Özdemir, Serpil; Özdemir, AydoğanWeather-dependent distributed renewable energy sources such as photovoltaics (PVs) and wind turbines (WT) are increasingly being connected to distribution networks (DNs). Increased penetration of these intermittent sources brought the necessity of using energy storage systems (ESSs) to achieve the intended benefits. This study presents an optimization process to determine optimal numbers, sizes, locations and distributed energy resources (DERs) as well as to determine the optimal operating strategy of ESSs in a distribution network. The objective is to improve the voltage profile and to minimize the installation costs. The proposed multi-objective formulation problem is solved by using ant lion multi-objective optimization algorithm. At the second part of the study, optimal values are tested with monthly extreme distributions and the impacts of load and distributed generation volatilies on the voltage profiles which were determined by Pareto-optimal solution candidates are analysed. Simulations were performed on 33 bus radial distribution system using Matlab. Finally the benefits obtained by the optimal solutions with less risk are compared.Article Citation - WoS: 0Citation - Scopus: 0A Qualitative Study of Unveiling School Dropout Complexity in Türkiye(Springer, 2024) Özdemir, Serpil; Kemer, Fatma Nur Aras; Arslan, Arif; Tuna, BurakThis study investigates school dropout, particularly the shift to open high schools in Turkiye during the pandemic, through a multi-stakeholder lens. Using grounded theory, data was collected via semi-structured interviews with 12 students, 15 teachers, and 20 school administrators. Results reveal a model linking themes: predictive reasons for transferring to open high school, both pandemic-related and unrelated, positive/negative consequences of the transition, pandemic's impact on formal education continuity, essential open high school skills, and strategies to reduce such preferences. Findings highlight the sway of exam-focused education on open high school interest, regardless of COVID-19, and emphasize the need for equitable education amidst Turkiye's pandemic challenges. Theoretical implications may infer the necessity of approaching school dropout as a multilayered dynamic issue within the cultural context. The implications also may convey the significance of policies and systems not only to reduce the rates of school dropout but also critically unpack underlying reasons to make improvements.Article Citation - WoS: 2Citation - Scopus: 6Branch Outage Simulation Based Contingency Screening by Gravitational Search Algorithm(Praise Worthy Prize Srl, 2012) Ceylan, Oğuzhan; Ceylan, Oğuzhan; Özdemir, Aydoğan; Dağ, Hasan; Dağ, Hasan; Özdemir, SerpilPower systems contingency analysis is an important issue for electric power system operators. This paper performs branch outage simulation based contingency screening using a bounded network approach. Local constrained optimization problem representing the branch outage phenomena is solved by the gravitational search algorithm. The proposed method is applied to IEEE 14 30 57 and 118 Bus Test systems and its performance from the point of capturing violations is evaluated. In addition false alarms and the computational accuracy of the proposed method are also analyzed by using scattering diagrams. Finally the proposed gravitational search based contingency screening is compared with full AC load flow solutions from the point of computational speed. Copyright (C) 2012 Praise Worthy Prize S.r.l. - All rights reserved.Master Thesis How Does New Media Affect the Creative Department of Advertising Agencies in Turkey?(Kadir Has Üniversitesi, 2014) Özdemir, Serpil; Özdemir, Serpil; Binay Kurultay, Ayşe; Yalkın, Çağrı; Binay Kurultay, Ayşe; Yanardağoğlu, EylemBu çalışmanın amacı, yeni birer reklam mecrası haline dönüşen dijital platformların Türk Reklam Ajanslarının kreatif departmanlarının işleyişine etkilerini araştırmaktır. Reklam sektöründe son yıllarda yaşanan dijital dönüşümün, reklamın en önemli unsuru olan yaratıcılık becerisini nasıl değiştirdiğini, yaratıcı departmanların bu değişimle birlikte nasıl bir dönüşüm yaşadığını incelemektir. Öncelikle reklam tarihinin ve yaratıcılığın tarihsel gelişiminin inceleneceği bu çalışmada yakın zamanda ortaya çıkan geleneksel ajans-dijital ajans ayırımının yaratıcı departmanlarda çalışan reklamcıların iş ve görev tanımlarına nasıl yansıdığnın incelemesi yapılacaktır. Yakın zamanda Türkiye'deki yaratıcı ajansların yapısal değişikliğine dair yapılacak bu çalışma için otuza yakın üst düzey yaratıcı-yöneticilerle derin mülakat yapılması hedeflenmektedir. Farklı ajans türlerinden- Geleneksel ajanslardan, dijital ajanslardan, sosyal medya ajanslarından, entegre ajanslardan seçilmiş yaratıcı reklamcılara üç önemli konu hakkında sorular sorulacaktır: 1. Yeni medya, reklam ajanslarının kreatif departmanlarını yapısal olarak nasıl değiştirdi? Bu deparmanlarda çalışanların iş ve görev tanımlarını değiştirdi mi? Değiştirdiyse nasıl? 2. Yeni medyanın, reklam ajanslarındaki yaratıcı departmanların fonksiyonlarına etkisi ne oldu? Yaratıcı süreci nasıl etkiledi? 3. Yeni medya, yaratıcı ajansların müşterileriyle ilişkilerini hangi yönde etkiledi? Ajanslar arası ilişkileri nasıl yapılandırdı? Bu çalışmanın sonunda hedeflenen, dijital devrimin neden olduğu yeni medyanın ihtiyaçlarına cevap verecek, aynı zamanda geleneksel mecralara etkin yaratıcı çözümler sunan en etkili yaratıcı departmanın tarifini yaparak yakın geleceğin ideal reklam ajanslarıyla ilgili öngörüler geliştirmektir.Article Citation - WoS: 2Citation - Scopus: 2Double Branch Outage Modeling and Simulation: Bounded Network Approach(Elsevier Science, 2015) Ceylan, Oğuzhan; Dağ, Hasan; Özdemir, Aydoğan; Ceylan, Oğuzhan; Dağ, Hasan; Özdemir, SerpilEnergy management system operators perform regular outage simulations in order to ensure secure operation of power systems. AC power flow based outage simulations are not preferred because of insufficient computational speed. Hence several outage models and computational methods providing acceptable accuracy have been developed. On the other hand double branch outages are critical rare events which can result in cascading outages and system collapse. This paper presents a double branch outage model and formulation of the phenomena as a constrained optimization problem. Optimization problem is then solved by using differential evolution method and particle swarm optimization algorithm. The proposed algorithm is applied to IEEE test systems. Computational accuracies of differential evolution based solutions and particle swarm optimization based solutions are discussed for IEEE 30 Bus Test System and IEEE 118 Bus Test System applications. IEEE 14 Bus Test System IEEE 30 Bus Test System IEEE 57 Bus Test System IEEE 118 Bus Test System and IEEE 300 Bus Test System simulation results are compared to AC load flows in terms of computational speed. Finally the performance of the proposed method is analyzed for different outage configurations. (C) 2015 Elsevier Ltd. All rights reserved.Book Part Citation - Scopus: 12Comparison of Post Outage Bus Voltage Magnitudes Estimated by Harmony Search and Differential Evolution Methods(2009) Ceylan, Oğuzhan; Ceylan, Oğuzhan; Özdemir, Aydoğan; Dağ, Hasan; Dağ, Hasan; Özdemir, SerpilContingency studies are indispensable tools of both the power system planning and operational studies. Real time implementation of operational problems makes necessary the use of high speed computational methods while requiring reasonable accuracies. On the other hand, accuracy of the results and the speed of calculation depend on branch outage modeling as well as solution algorithm used. This paper presents a comparison of post outage bus voltage magnitudes calculated by two meta-heuristic approaches; namely differential evolution (DE) and harmony search (HS) methods. The methods are tested on IEEE 14, IEEE 30, IEEE 57, and IEEE 118 bus test systems and the results are compared both in terms of accuracy and calculation speed.Conference Object Citation - WoS: 8Citation - Scopus: 12Voltage Profile Improving and Peak Shaving Using Multi-Type Distributed Generators and Battery Energy Storage Systems in Distribution Networks(Institute of Electrical and Electronics Engineers Inc., 2020) Ahmedi, Bahman; Ceylan, Oğuzhan; Ceylan, Oğuzhan; Özdemir, Serpil; Özdemir, AydoğanOptimal sizing and siting of distributed generation (DG) units play an important role for improving voltage profile and reducing power losses. Moreover, battery energy storage system (BESS) units may help peak shaving. This paper presents a two stage approach, first of which aims optimal DG unit allocation, and second aims to determine optimal location and operation of BESS units. The problem formulation adopted due to the regulations in Turkey that supports DG units (Photovoltaics-PVs and Wind Turbines-WTs) with maximum unit size of 1 MW. A recently developed heuristic optimization method named as Harris hawks optimization (HHO) algorithm is used for obtaining near optimal solutions. We tested the developed model by using 33 and 141 bus distribution test systems.Conference Object Citation - WoS: 4Citation - Scopus: 9Design and Practical Implementation of a Parallel-Switched Power Factor Correction Boost Converter(IEEE, 2021) Rahman, Showrov; Özdemir, Serpil; Kosesoy, Yusuf; Aydemir, Mehmet Timur; Ozdemir, Mehmet Akif; Simsek, Oguz; Aydemir, M. Timur; Chub, AndriiIn the past years, applications of Power Factor Correction (PFC) boost converter have increased significantly. One recent application field that requires an efficient PFC boost converter is the Wireless Power Transfer system (WPT). In this paper, the design of a single-phase PFC boost converter is presented. The proposed converter comprises three parallel switches to reduce the component stress and ensuring safe circuit operation. It utilizes FAN6982 Continuous Conduction Mode (CCM) controller. The design of the controller circuit and the controller parameter specifications are presented. Design guidelines for components are provided. The designed PFC boost converter is first validated in PSIM simulation software and then a 1.5 kW/ 350 V-dc prototype is implemented. The experimental results verify that the PFC boost converter achieves the power factor of 0.99 at the full load.Conference Object Citation - WoS: 1A Load Adaptive Cascade Pi Controller for Buck Converters Operating in Wide Load Range in Cathodic Protection Systems(IEEE, 2021) Ozdemir, Mehmet Akif; Aydemir, Mehmet Timur; Simsek, Oguz; Özdemir, Serpil; Aydemir, Mehmet TimurThis paper proposes a simple cascade PI controller for Buck converter to be used in impressed current cathodic protection (ICCP) systems which aim to operate in wide voltage and current ranges for any load condition. The Buck converter with cascade controller structure is a frequently used topology in ICCP systems to prevent buried steel pipelines from corrosion. Changes in the environment in which the pipe is embedded force the converter to operate at wide load and voltage ranges. However, in average current mode controllers, the gain of the current loop varies significantly with the load. At light loads, the inner current loop slows down dramatically and may stay behind the outer voltage loop. In order to solve these issues and to maintain the regulation of the pipeline voltage and the average load current, this paper presents a simple cascade PI controller whose coefficients are adapted to the changing load. The small signal analysis of the Buck converter in both continuous conduction mode (CCM) and discontinuous conduction mode (DCM) is performed and variables determining the transfer characteristics are examined. For the proposed controller, a design criteria based on circuit parameters have been established. With the parameters obtained by the proposed method, a sample cascade controller is designed and compared with classical PI controller in simulation. Also, a digitally controlled 100-W converter prototype is built to validate the performance.Conference Object Citation - WoS: 21Citation - Scopus: 34Grey Wolf Optimizer for Allocation and Sizing of Distributed Renewable Generation(Institute of Electrical and Electronics Engineers Inc., 2019) Ahmadi, Bahman; Ceylan, Oğuzhan; Ceylan, Oğuzhan; Özdemir, Serpil; Özdemir, AydoğanIncreasing penetration of distributed energy resources (DERs) have brought operational and control philosophy changes in Smart Grids (SGs). Renewable energy based technologies are becoming more important due to their economic and environmental impacts. Distributed generations (DGs) in the form of small renewable energy resources such as solar photovoltaics (PVs) and Wind Turbines (WTs) are connected in radial distribution networks near to the loads. This paper presents optimal siting and sizing of distributed renewable energy resource to maintain voltage magnitude profiles. Bus voltage magnitude differences for each hour in a day of a distribution system are formulated as an objective function. Three consecutive days are taken into account representing the three seasons of a year. A new nature inspired algorithm Grey Wolf Optimizer (GWO) is used as a solution tool. The proposed formulation is applied to 33 bus and 69 bus radial distribution networks. MATLAB simulations are performed to validate the performance of the approach. Simulation results are discussed and compared with of the several available ones'.
