13 research outputs found
A Deep Neural Network-Assisted Approach to Enhance Short-Term Optimal Operational Scheduling of a Microgrid
Economic-Environmental Analysis of Combined Heat and Power-Based Reconfigurable Microgrid Integrated with Multiple Energy Storage and Demand Response Program
Microgrids (MGs) are solutions to integrate high shares of variable renewable energy which can contribute to more economical and environmental benefits, as well as improving the energy supply efficiency. One significant potential of MGs is an expanded opportunity to use the waste heating energy from the conversion of the primary fuel (such as natural gas) to generate electricity. The use of waste heat in combined heat and power (CHP)-based MG is more efficient to meet local load and decrease the emission pollution. Hence, this paper elaborates on optimal multi-objective scheduling of CHP-based MG coupled with compressed air energy storage (CAES), renewable energy, thermal energy storage (TES), and demand response programs through shiftable loads, which considers a reconfiguration capability. The embedded CAES, in addition to the charging/discharging scheme, can operate in a simple cycling mode and serve as a generation resource to supply local load in an emergency condition. The daily reconfiguration of MG will introduce a new generation of MG named reconfigurable microgrid (RMG) that offers more flexibility and enhances system reliability. The RMG is coupled with TES to facilitate the integration of the CHP unit that enables the operator to participate in the thermal market, in addition to the power market. The main intents of the proposed multi-objective problem are to minimize the operation cost along with a reduction in carbon emission. The epsilon-constraint technique is used to solve the multi-objective problem while fuzzy decision making is implemented to select an optimal solution among all the Pareto solutions. The electricity prices and wind power generation variation are captured as random variables in the model and the scenario-based stochastic approach is used to handle them. Simulation results prove that the simultaneous integration of multiple technologies in CHP-based RMG decreases the operation cost and emission up to 3% and 10.28%, respectively
Boycott Days in Shi bu Abi Talib
dinbilArap tarihinde örneğine rastlanılmayan ilginç bir kitlesel cezalandırma yöntemi olan boykot, Müslümanlara karşı uygulanmış gibi algılanmaktadır. Oysaki boykot, sadece Hz. Peygamber’i koruyan Hâşimoğulları’nın inanan-inanmayan tüm bireylerine uygulanmıştır. Bu süre zarfında çok sayıda kişinin öldüğü ifade edilse de kaynaklarda konuyla ilgili detaylı bilgi mevcut değildir. Kabilecilik anlayışının hâkim olduğu Mekke’de haklı da olsa haksız da olsa insanların kendi kabile bireylerinin etrafında kenetlenmesini gösteren bu hadise, dolaylı olarak Hz. Peygamber’in İslam davetini de koruduğu söylenebilir. Ayrıca görünürde müşriklerin talebi Hz. Peygamber’in öldürülmesi ya da kendilerine teslim edilmesi olsa da arka planda kabile rekabeti de yatmaktadır. Müşriklerin İslam davetini durdurmak amacıyla başvurdukları bu yöntem onların beklentilerini karşılayamamış aksine yine kendi aralarında bulunan kimselerin girişimiyle boykot sona ermiştir. Mucizevi bir şekilde “güve”nin musallat olduğu sahifeyi yemesiyle boykotun son bulduğu rivayet edilse de gerçekte inisiyatif alan insaf ehli kimselerin girişimiyle son bulmuştur. Ayrıca zalime karşı mazlumun yanında yer alan Hılfu’l-Fudûl’un bu süreçte neden pasif kaldığı konusunda net bir bilgi mevcut değildir. Boykottan sonra Hz. Peygamber Mekke’den ümidini kesmiş ve yeni yurt arayışlarına başlamıştır. Boykot hadisesi kaynakların çoğunda yer almaktadır. Ancak bu süreçle ilgili kaynaklarda detaylı bilgi ve somut verilerden ziyade genel anlatım ve birtakım dramatik sahneler yer almaktadır. Çalışmada, kaynaklardaki verilerden hareketle boykotun tarihsel süreci ele alınırken öte yandan önemli değerlendirme ve tespitleri olan araştırmalardan da faydalanılmıştır. Böylelikle boykotla ilgili doğru tespitlerin ortaya konulması ve mevcut birtakım duygusal algılar yerine hadisenin olgular üzerinden değerlendirilmesi hedeflenmiştir.The boycott, which is an interesting method of mass punishment that has not been seen in Arab history, is perceived as a social isolation applied by the polytheists against Muslims. However, the boycott only it was applied to all believers and non-believers of the Hashim sons who protected the Prophet. Whereas, boycott is a social embargo imposed by the Meccan polytheists on all believers and non-believers of the Hashim sons who protected the Prophet. It is rumored that many people died in this process. However, there are no details on this subject in the literature. This event shows that in Mecca, where the understanding of tribalism is dominant, whether it is right or wrong, people come together around their own tribe members. It can be said, within the framework of this event, indirectly, that the Prophet’s invitation to Islam also was protected. In addition, although the polytheists apparently demand that the Prophet be killed or handed over to them, tribal rivalries lie in the background. This method, which the polytheists resorted in order to stop the invitation to Islam, could not meet their expectations, on the contrary, the boycott was ended with the initiative of those who were among them. Although it is rumored that the boycott ended when the "moth" miraculously ate the page, it actually came to an end with the initiative of merciful people who took the initiative. In addition, there is no clear information about why Hilf al-Fudul, which was on the side of the oppressed against the oppressor, remained passive in this process. After the boycott, the Prophet gave up hope in Mecca and started to search for a new homeland. The boycott incident takes place in most of the literature. However, sources related to this process contain general narration and some dramatic scenes rather than detailed information and concrete data. In the study, while the historical process of the boycott is discussed based on the data in the literature, on the other hand, studies with important evaluations and determinations were also used. In this way, it is aimed to reveal the correct determinations about the boycott and to evaluate the incident through facts instead of some existing emotional perceptions.101828
An Ensemble Deep-Learning-Based Model for Hour-Ahead Load Forecasting with a Feature Selection Approach: A Comparative Study with State-of-the-Art Methods
The realization of load forecasting studies within the scope of forecasting periods varies depending on the application areas and estimation purposes. It is mainly carried out at three intervals: short-term, medium-term, and long-term. Short-term load forecasting (STLF) incorporates hour-ahead load forecasting, which is critical for dynamic data-driven smart power system applications. Nevertheless, based on our knowledge, there are not enough academic studies prepared with particular emphasis on this sub-topic, and none of the related studies evaluate STLF forecasting methods in this regard. As such, machine learning (ML) and deep learning (DL) architectures and forecasters have recently been successfully applied to STLF, and are state-of-the-art techniques in the energy forecasting area. Here, hour-ahead load forecasting methods, the majority of which are frequently preferred high-performing up-to-date methods in the literature, were first examined based on different forecasting techniques using two different aggregated-level datasets and observing the effects of these methods on both. Case and comparison studies have been conducted on these high-performing methods before, but there are not many examples studied using data from two different structures. Although the data used in this study were different from each other in terms of the time step, they also had very different and varied features. In addition, feature selection was studied on both datasets and a backward-eliminated exhaustive approach based on the performance of the artificial neural network (ANN) on the validation set was proposed for the development study of the forecasting models. A new DL-based ensemble approach was proposed after examining the results obtained on two separate datasets by applying the feature selection approach to the working forecasting methods, and the numerical results illustrate that it can significantly improve the forecasting performance compared with these up-to-date methods
Öğrenme nesneleri tasarımının öğretmen adaylarının eleştirel, yaratıcı düşünme ve bilimsel süreç becerilerine etkisi
ÖZET Bu araştırmada, öğrenme nesneleri tasarımının matematik öğretmen adaylarının eleştirel, yaratıcı düşünme ve bilim süreç becerilerine etkisinin incelenmesini amaçlanmıştır. Araştırmanın çalışma grubunu; Marmara Üniversitesi, Atatürk Eğitim Fakültesi, İlköğretim Bölümü, İlköğretim Matematik Öğretmenliği üçüncü sınıfta okumakta ve Web Destekli Matematik Öğretimi dersini almakta olan birinci ve ikinci öğretim toplam 48 öğretmen adayı öğrenci oluşturmaktadır. Bu çalışmada, öğrenme nesneleri tasarımının matematik öğretmen adaylarının eleştirel, yaratıcı düşünme ve bilimsel süreç becerilerine etkisini araştırmak amacıyla ön test - son test kontrol gruplu yarı deneysel yöntem (quasi-experimental design) kullanılmıştır. Ön test - son test kontrol gruplu desen çerçevesinde, bağımlı değişkenler öğretmen adaylarının eleştirel düşünme, yaratıcı düşünme ve bilimsel süreç becerileridir. Bu bağımlı değişkenler üzerinde etkisi incelenen bağımsız değişken ise öğrenme nesne tasarımı merkezli yaklaşımdır. Çalışmada bağımsız değişkenin bağımlı değişken üzerindeki etkisini incelemek amacıyla kontrol ve deney grupları oluşturulmuştur. Kontrol grubunda müfredatta belirtilen ders içeriğine uygun ve öğretmen merkezli klasik bir yaklaşım izlenirken, deney grubunda öğrenme nesne tasarımı merkezli yaklaşım izlenmiştir. Araştırmanın verilerinin toplanabilmesi için “Öğretmen Adayı Kişisel Bilgi Formu”, “Eleştirel Düşünme Eğilimi Ölçeği”, “Yaratıcı Düşünme Ölçeği” ve “Bilimsel Süreç Becerileri Testi” araçlarından yararlanılmıştır. Araştırma modeline uygun olarak yapılan ölçümler sonunda, elde edilen verilen çözümlenmesi ve analizinde bir istatistik paket programı kullanılmıştır. Her bir grup için örneklem genişliği 30’dan küçük (N=24) olduğu ve veriler normal dağılım göstermediği için parametrik özellikte olmayan Mann-Whitney U Testi (gruplar arası karşılaştırmalarda) ve Wilcoxon İşaretli Sıralar Testi (grup içi karşılaştırmalarda) kullanılmıştır. Tüm analizler %95 güven aralığında yapılmış ve p,05) son test puanları arasında istatistiksel olarak anlamlı bir fark bulunmamıştır.Öğrenme nesne tasarımı ile ilgili eğitim alanındaki birkaç tez çalışmasından biri olması, alan yazına yaptığı katkı ve elde edilen bulguları itibariyle araştırmanın önemli olduğu düşünülmektedir.Anahtar Kelimeler: Öğrenme Nesnesi, Eleştirel Düşünme, Yaratıcı Düşünme, Bilimsel Süreç Becerileri, Matematik EğitimiABSTRACT This study aims to investigate the effects of design practices in learning objects upon the critical and creative thinking capacities; as well as the science process skills of prospective mathematics teachers. The study group of the research is comprised of 48 prospective mathematics teachers in their 3rd year of education, who are enrolled in the day-time and evening educational programs of Marmara University Atatürk Education Faculty Department of Primary Education Division of Primary School Mathematics Education and who have been receiving the Web-Based Mathematics Education subject throughout the research period. This study employs a quasi-experimental, pre-test post-test control group research design in order to investigate the effects of design practices in learning objects upon the critical and creative thinking capacities; as well as the science process skills of prospective mathematics teachers.As per the pre-test post-test control group research pattern, the dependent variables have been designated as the critical thinking capacities, creative thinking capacities and science process skills of prospective mathematics teachers. The independent variable, whose effect upon these dependent variables has been investigated, is the learning-object design centered educational approach. In order to observe the effects of the independent variable upon the dependent variables, experimental and control groups have been established during the study. Whereas a classic, teacher-based approach based on the existing curriculum has been employed in the control group, the experimental group has been subject to a learning-object design centered approach. Several data collection instruments have been used throughout the study, namely the “Prospective Teacher Personal Data Form”, the “Critical Thinking Tendency Scale”, “Creative Thinking Tendency Scale” and “Science Process Skills Test”. An statistical analysis software package has been used to analyze data gathered as a result of measurements conducted in accordance with the research pattern. Due to the facts that for each group, the sample sizes were smaller than 30 (N=24) and that, the data did not follow a normal distribution pattern; Mann-Whitney U Test and Wilcoxon Signed Rank Tests have been used for intergroup and intragroup comparisons, respectively. All analyses have been carried out in the 95% confidence interval and p,05). The significance of the research is believed to be based on the fact that it is one of the few thesis studies regarding learning objects design in the field of pedagogy, and the findings that it contributes to the existing literature.Keywords: Learning Objects, Critical Thinking, Creative Thinking, Science Process Skills, Mathematics Educatio
Öğrenim yönetim sistemlerine ve öğrenim içerik yönetim sistemlerine tasarım ve geliştirme modellerinin uygulanması
ÖZETBu tez çalışmasında, uzaktan eğitim ortamların etkin yönetimi için kullanılan Öğrenim Yönetim Sistemleri (ÖYS) ve Öğrenim İçerik Yönetim Sistemlerine (ÖİYS), tasarım ve geliştirme modellerinin nasıl uygulanabileceği araştırılmıştır. Literatür bilgileri ışığında, ÖYS olarak Kavrakoğlu Danışmanlık Şirketi’nin geliştirdiği The MBA Club ürünü, ÖİYS olarak ise mevcut ürünün içerikle beraber güncelleme alt yapısı baz olarak alınmış, analiz edilmiştir.Çalışmanın literatür bölümünde gerek yerli ve gerekse yabancı kaynaklardaki sınırlı sayıdaki bilgi ve belge, tez konusu çerçevesinde sunulmuştur. Bulgu ve Yorumlar bölümünde ise literatürün pratikteki uygulaması yapılmış ve değerlendirilmiştir. Bu bağlamda tasarım modeli olarak, bilişim sistemlerinin tasarımında kullanılmakta olan Şelale Modeli seçilmiştir. İçerik geliştirme aşamasında ise kapsamlı ve anlaşılır bir yapıdaki Seels & Glasgow Öğretim Tasarım Modeli tercih edilmiştir. Bir tasarım modeli olan Şelale Modeli, The MBA Club ÖYS yapısında; içerik geliştirme ve öğretim tasarım modeli olan Seels & Glasgow Öğretim Tasarım Modeli ise The MBA Club ÖİYS yapısında incelenmiştir. Şelale Modeli’nin arayüz tasarlaması basamağı, ÖYS ana ders ekranı ve “Satış ve Kanal Yönetimi” dersinde uygulanmıştır. Benzer şekilde Seels & Glasgow Öğretim Tasarım Modeli’nin Problem Analizi ve Görev - Öğretim Analizi Basamakları ise ÖİYS “Değer Yaratma İşlevi” dersi içeriğinde denenmiştir.Kavrakoğlu Şirketi’nin geliştirdiği The MBA Club ürünü, piyasada tanınmış firmalar tarafından tercih edilen ve rakiplerine kıyasla çok üst sıralarda yer alan bir ÖYS - ÖİYS olmasına karşın, temel düzeyde tezde belirtilen eksiklikleri içermesinden ötürü bilimsel altyapı eksikliği taşımaktadır. Bu eksiklik; mevcut ürünün yeniden gözden geçirilerek revizyonların yapılması, tüm ders ekranlarında ortak modelleme çizgisinin yakalanması ve içeriğin öğretimsel açıdan tekrar düzenlenmesiyle anlamlı bir şekilde geliştirilmiştir. ABSTRACTIn this thesis study, it has been researched how design and development models will be practised on Learning Management Systems (LMS) and Learning Content Management Systems (LCMS) which are used for the active management of distant learning media. In the light of the literature information, the product named The MBA Club developed by Kavrakoğlu Consultancy Company has been analyzed as for LMS, and for LCMS, the content and updating substructure of the current product have been analyzed.In the literature chapter of the research, the limited information and documents in both domestic and foreign sources have been presented in the framework of the thesis. In the chapter of Findings and Comments, the practice of the literature has been performed and assessed. In this context, The Waterfall Model utilized in the design of informatics systems has been chosen as the design model. In the phase of content development, Seels & Glasgow Instructional Design Model of a comprehensive and understandable nature has been preferred. Waterfall model, the design model, has been examined in the LMS of The MBA Club, whereas Seels & Glasgow Instructional Design Model has been examined in the LCMS of The MBA Club. The interface designing step of the Waterfall Model has been practised in the main course screen and in the course of “Sales and Channel Management”. Similarly, the steps of Problem Analysis (Needs Assessment) and Task- Instructional Analysis of Seels & Glasgow Instructional Design Model have been tested in the course of “Value Creation Function” of LCMS.Despite the fact that The MBA Club developed by Kavrakoğlu Company is a LMS- LCMS which is preferred by well-known firms and which is at the top places when compared to its rivals, it has a scientific infrastructure lack that is stated basically in the thesis. This lack; has been developed in a meaningful way with the revisions of the current product after being reviewed, with the efforts for achieving common modeling line and with the rearrangement of the content in terms of instruction
A Multivariate Time Series Analysis of Electrical Load Forecasting Based on a Hybrid Feature Selection Approach and Explainable Deep Learning
In the smart grid paradigm, precise electrical load forecasting (ELF) offers significant advantages for enhancing grid reliability and informing energy planning decisions. Specifically, mid-term ELF is a key priority for power system planning and operation. Although statistical methods were primarily used because ELF is a time series problem, deep learning (DL)-based forecasting approaches are more commonly employed and successful in achieving precise predictions. However, these DL-based techniques, known as black box models, lack interpretability. When interpreting the DL model, employing explainable artificial intelligence (XAI) yields significant advantages by extracting meaningful information from the DL model outputs and the causal relationships among various factors. On the contrary, precise load forecasting necessitates employing feature engineering to identify pertinent input features and determine optimal time lags. This research study strives to accomplish a mid-term forecast of ELF study load utilizing aggregated electrical load consumption data, while considering the aforementioned critical aspects. A hybrid framework for feature selection and extraction is proposed for electric load forecasting. Technical term abbreviations are explained upon first use. The feature selection phase employs a combination of filter, Pearson correlation (PC), embedded random forest regressor (RFR) and decision tree regressor (DTR) methods to determine the correlation and significance of each feature. In the feature extraction phase, we utilized a wrapper-based technique called recursive feature elimination cross-validation (RFECV) to eliminate redundant features. Multi-step-ahead time series forecasting is conducted utilizing three distinct long-short term memory (LSTM) models: basic LSTM, bi-directional LSTM (Bi-LSTM) and attention-based LSTM models to accurately predict electrical load consumption thirty days in advance. Through numerous studies, a reduction in forecasting errors of nearly 50% has been attained. Additionally, the local interpretable model-agnostic explanations (LIME) methodology, which is an explainable artificial intelligence (XAI) technique, is utilized for explaining the mid-term ELF model. As far as the authors are aware, XAI has not yet been implemented in mid-term aggregated energy forecasting studies utilizing the ELF method. Quantitative and detailed evaluations have been conducted, with the experimental results indicating that this comprehensive approach is entirely successful in forecasting multivariate mid-term loads
Investigation of Power Quality in a System Based on Renewable Energy Sources
In the power systems, non-linear electrical loads connected to the grid in practice pose significant power quality problems on power electronics circuit elements. Due to the increasing energy demand and the increase in the production rate of renewable energy in installed power, these effects are becoming more and more serious day by day. With this in-depth study of energy quality, studies in general emphasized that monitoring energy quality in theory and practice is of great importance. This study aims to shed light on the investments and technological developments that can be made for the development of the network infrastructure by providing an overview of these dynamic new situations changes in classical and smart networks, stabilizers,
relay design, control technologies, power quality analysis and monitoring. It also focuses on topologies and control methods for energy quality regulators in power systems, especially applicable control technologies in distributed power plants according to the new features of power quality. Finally, the trends and expectations of power quality monitoring technology, which are important for reliable and efficient operation in smart grids, are presented
USING THE RELATIONSHIP BETWEEN PERIODIC CONTINUED FRACTION AND QUADRATIC IRRATIONALS: ASAB - II CIPHER
Bir periyodik sürekli kesir belli noktadan itibaren tekrar devam eden bir kısımdır. Tüm aşikar olmayan periyodik sürekli kesirler, irrasyonel sayılar olarak gösterilebilir. Genel olarak, sonsuz bir basit kesir (veya başka şekilde periyodik) ve tek bir irrasyonel sayı gösterir ve her irrasyonel sayı tek bir sonsuz sürekli kesire sahiptir.
Bir kuadratik irrasyonel sayı tam katsayılı ikinci dereceden bir denklemin bir köküdür. Kuadratik irrasyonel sayılar sonsuz periyodik sürekli kesir açılımları olan reel sayılardır. Matematikte, bir kuadratik, irrasyonel sayı bir kuadratik irrasyonel veya ikinci dereceden irrasyonel olarak da bilinen irrasyonel sayılar, rasyonel katsayılı bazı ikinci dereceden denklemin çözüm dür.
Bu çalışmanın amacı, periyodik sürekli kesir ve ikinci dereceden irrasyonel arasındaki ilişki kullanılarak, "ASAB-II" şifrelme (yazarların adlan ilk) adı verilen yeni bir tekniği geliştirmektir. Ayrıca, algoritma ASAB -I yapışım daha güçlü kılan bir algoritma yı elde etmeyi ümit ederiz
Optimal Operational Scheduling of Reconfigurable Microgrids in Presence of Renewable Energy Sources
Passive distribution networks are being converted into active ones by incorporating distributed means of energy generation, consumption, and storage, and the formation of so-called microgrids (MGs). As the next generation of MGs, reconfigurable microgrids (RMGs) are still in early phase studies, and require further research. RMGs facilitate the integration of distributed generators (DGs) into distribution systems and enable a reconfigurable network topology by the help of remote-controlled switches (RCSs). This paper proposes a day-ahead operational scheduling framework for RMGs by simultaneously making an optimal reconfiguration plan and dispatching controllable distributed generation units (DGUs) considering power loss minimization as an objective. A hybrid approach combining conventional particle swarm optimization (PSO) and selective PSO (SPSO) methods (PSO&SPSO) is suggested for solving this combinatorial, non-linear, and NP-hard complex optimization problem. PSO-based methods are primarily considered here for our optimization problem, since they are efficient for power system optimization problems, easy to code, have a faster convergence rate, and have a substructure that is suitable for parallel calculation rather than other optimization methods. In order to evaluate the suggested method’s performance, it is applied to an IEEE 33-bus radial distribution system that is considered as an RMG. One-hour resolution of the simultaneous network reconfiguration (NR) and the optimal dispatch (OD) of distributed DGs are carried out prior to this main study in order to validate the effectiveness and superiority of the proposed approach by comparing relevant recent studies in the literature