Bilgisayar Mühendisliği Bölümü Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.11779/1940
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Master Thesis EAFT: Evolutionary algorithms for GCC flag tuning(MEF Üniversitesi, 2023) Çakar, Tuna; Çakar, Tuna; 02.02. Department of Computer Engineering; 02. Faculty of Engineering; 01. MEF UniversityThe runtime of written codes is a matter of great importance, especially for code that is compiled once and executed multiple times. It is very important for developers to ensure that the resources required by a code are used as efficiently as possible, and that the runtime is as low as possible. Developers who use compilers such as GCC or LLVM to compile and run code written in C or C++ can optimize their code manually and, with certain optimization pointers, are able to make it run faster. This will provide the shorter runtime, but completıng this manual optimization is within the abilities of every developer since determining the right combination from more than 200 flags requires significant expertise. Many studies have tackled this issue. In this study, Evolutionary Algorithms for GCC Flag Tuning (EAFT) have been developed as a solution to this problem. This Autotuner, which is completely open-source, runs the code provided by the end user according to the specifications also selected by the end user, and searches for the most suitable optimization markers. For the code to be given In line with this study, which specifically addresses the end user, the user can input the code path directly from the Terminal, as well as specify the selection method and the crossover to be used. These choices can be made without the need to alter the code. The genetic algorithm and particle swarm optimization to be used is also presented to the user in EAFT, and unlike in other studies, genetic algorithm contain not one but several models.Research Project İmece-depo: İşbirlikçi Hücresel Ağlarda Veri Önbellekleme için Cihazdan Cihaza Iletişim ile Dağıtık Depolama, Optimale Yakın Kodlama ve Protokol Tasarımı.(2023) Haytaoğlu, Elif; Pourmandı, Massoud; Kaya, Erdi; Arslan, Şefik Şuayb; 02.02. Department of Computer Engineering; 02. Faculty of Engineering; 01. MEF UniversityHücresel ağlarda popüler dosyaların cihazlarda önbelleklenmesi ile, cihazlar arası etkileşim baz istasyonu (Bİ) üzerine düşen iletişim yükünü oldukça azaltmaktadır. Dağıtık veri önbellekleme işlemi popüler bir dosyanın parçalarının kodlanmamış orijinal haliyle ya da herhangi bir silinti kodu kullanılarak kodlanmış halinin mobil cihazlar içerisinde dağıtık bir şekilde depolanması yardımıyla gerçekleştirilir. Dosyanın herhangi bir parçası, komşu mobil cihazlardan ya da mümkün değilse, doğrudan Bİ?lerden, yüksek bir iletişim maliyeti pahasına indirilebilir. Bir hücresel ağda, rastgele zamanlarda bazı düğümlerin hücreye katıldığı ve bazılarının ayrıldığı göz önüne alındığında, performans için Bİ ile iletişimin minimum düzeyde olmasını sağlayacak akıllı veri onarım yöntemlerine ihtiyaç duyulacaktır. Tek bir veya birden fazla Bİ?nin sisteme katılımı, önceki onarım paradigmalarına, özellikle de işbirlikçi düğüm onarım süreçlerine farklı bir boyut eklemektedir. Bunun nedeni, çalışma protokolü kurallarının yanı sıra iletişim kısıtlamalarının da değişmesidir. Literatür, bu durum için temel bant genişliği/depolama ödünleşim uzayını inceleyen bir çalışma içermemektedir. Yeni hücre mimarileri buna göre, yeni silinti kod yapılarını, verimli protokol tasarımlarını, veri erişim gecikmesi, gerçekçi kuyruk modelleri ve gerçekçi benzetim platformları dahil ancak bunlarla sınırlı olmamak üzere farklı tasarım değerlendirmelerini gerektirmektedir. Bu projede ilk olarak, daha önceki hiçbir çalışmada düşünülmemiş işbirliği yapan Bİ?lerin cihaz ayrılışlarında yaşanan kayıp verinin onarımı için bant genişliği ve depolama kapasitesinin iyileştirilmiş teorik sınırlarının veri akış diyagramları kullanılarak elde edilmesi amaçlanmıştır. Bununla beraber, bant genişliği ve depolama alanını en iyi kullanan kod yapılarından esinlenerek, veri önbellekleme işlemini optimale yakın bir maliyetle gerçekleştirecek tamamen özgün çizge tabanlı kod yapıları ve bu yeni kodlar için daha önce düğüm onarım problemine uygulanmamış genetik algoritma, optimize edilmiş artık veri dağıtımı gibi yeni yaklaşımlar kullanılarak önceden düşünülmemiş düğüm onarım algoritmaları önerilecektir. Ayrıca, düğümlerin hücreye katılma ve ayrılma süreçleri için, bant genişliği ve veri depolaması gereksinimlerini en aza indirmeye yardımcı olacak enerji tüketimi odaklı son derece özgün protokoller önerilecektir. Bu protokoller, düğümlerin bir hücreden diğerine geçiş yapabileceği ve hücre içi kaynakların etkin kullanılmasına yardımcı olmak için Bİ?lerin işbirliği yapmasını sağlayan geçiş senaryoları ile güçlendirilecektir. Bu durum, iki onarım işlemi arasındaki sürenin ayarlanması, veri erişim maliyetlerinin azaltılması, hücreye katılan düğüm içeriğinin kullanımı, artık veri kullanımı v.s. gibi yenilikleri içerecektir. Son olarak, önerilen kod yapıları ve protokol mimarisinin performansını analitik olarak türetmek için bilinen çeşitli ve daha gerçekçi kuyruklama modelleri değerlendirilecektir. Analitik sonuçlarımızı doğrulamak için daha sonra hücresel ağ tabanlı büyük ölçekli benzetimler yapılıp sayısal yöntemler ile toplam iletişim ve dosya onarım işlemlerinin maliyet hesaplamaları ve karşılaştırmaları yapılacaktır. MEF Üniversitesi öğretim üyesi Dr. Şuayb Arslan?ın yürütücüsü olduğu ve 36 ay sürecek projede, Pamukkale üniversitesi Bilgisayar Mühendisliği Bölümü öğretim üyesi Dr. Elif Haytaoğlu araştırmacı olarak görev alacaktır. Projede, iki doktora, iki yüksek lisans ve son iki senemizde iki lisans öğrencisi bursiyer olarak görev alacaktır.Article Citation - Scopus: 5Investigation of the Motion of a Spherical Object Located at Soft Elastic and Viscoelastic Material Interface for Identification of Material Properties(Academic Enhancement Department, King Mongkut's University of Technology North Bangkok, 2023) Körük, Hasan; Körük, Hasan; 02.03. Department of Mechanical Engineering; 02. Faculty of Engineering; 01. MEF UniversityMeasuring the properties of soft viscoelastic materials is challenging. Here, the motion of a spherical object located at the soft elastic and viscoelastic material interface for the identification of material properties is thoroughly investigated. Formulations for different loading cases were derived. First, the theoretical models for a spherical object located at an elastic medium interface were derived, ignoring the medium viscosity. After summarizing the model for the force reducing to zero following the initial loading, we developed mathematical models for the force reducing to a lower non-zero value or increasing to a higher non-zero value, following the initial loading. Second, a similar derivation process was followed to evaluate the response of a spherical object located at a viscoelastic medium interface. Third, by performing systematic analyses, the theoretical models obtained via different approaches were compared and evaluated. Fourth, the measured and predicted responses of a spherical object located at a gelatin phantom interface were compared and the viscoelastic material properties were identified. It was seen that the frequency of oscillations of a spherical object located at the sample interface during loading was 10–15% different from that during unloading in the experimental studies here. The results showed that different loading cases have immense practical value and the formulations for different loading cases can provide an accurate determination of material properties in a multitude of biomedical and industrial applications. © 2023 King Mongkut’s University of Technology North Bangkok. All Rights Reserved.Article Citation - WoS: 15Citation - Scopus: 15Enhanced Primordial Gravitational Waves From a Stiff Postinflationary Era Due To an Oscillating Inflaton(Amer Physical Soc, 2024) Chen, Chao; Dimopoulos, Konstantinos; Eroncel, Cem; Ghoshal, Anish; 01. MEF UniversityWe investigate two classes of inflationary models, which lead to a stiff period after inflation that boosts the signal of primordial gravitational waves (GWs). In both families of models studied, we consider an oscillating scalar condensate, which when far away from the minimum is overdamped by a warped kinetic term, a la alpha-attractors. This leads to successful inflation. The oscillating condensate is in danger of becoming fragmented by resonant effects when nonlinearities take over. Consequently, the stiff phase cannot be prolonged enough to enhance primordial GWs at frequencies observable in the near future for low orders of the envisaged scalar potential. However, this is not the case for a higher-order scalar potential. Indeed, we show that this case results in a boosted GW spectrum that overlaps with future observations without generating too much GW radiation to destabilize big bang nucleosynthesis. For example, taking alpha=O(1), we find that the GW signal can be safely enhanced up to Omega(GW) (f)similar to 10(-11) at frequency f similar to 10(2) Hz, which will be observable by the Einstein Telescope. Our mechanism ends up with a characteristic GW spectrum, which if observed, can lead to the determination of the inflation energy scale, the reheating temperature, and the shape (steepness) of the scalar potential around the minimum.Article Citation - WoS: 6Citation - Scopus: 8Designing restorative landscapes for students: A Kansei engineering approach enhanced by VR and EEG technologies(Elsevier, 2024) Karaca, Elif; Çakar, Tuna; Karaca, Mehmet; Gul, Hasan Huseyin Mirac; Hüseyin Miraç Gül, Hasan; 02.02. Department of Computer Engineering; 02. Faculty of Engineering; 01. MEF UniversityThis study explores the alignment of specific landscape features within school environments with the core elements of Attention Restoration Theory (ART) that includes Coherence, Fascination, Compatibility, and Being Away. Utilizing Kansei Engineering, this research integrates emotional analysis into landscape design by employing Virtual Reality (VR) and Electroencephalogram (EEG) technologies to record students' responses to different landscape simulations. Analytical techniques, including the Taguchi Method and Analysis of Variance (ANOVA), were applied to evaluate the data. The findings have revealed that students associate a sense of enclosure with a coherent landscape and openness with a fascinating landscape, the lawn's significance was also highlighted for coherent landscape. However, limited insights were gained regarding Compatibility and Being Away. The study advocates for diverse cognitive zones within school landscapes to promote mental restoration, emphasizing the need for varied design elements that cater to the elevated experience of students.Article Citation - WoS: 1Citation - Scopus: 1Understanding the Psychological and Financial Correlates for Consumer Credit Use;(Sosyoekonomi Society, 2024) Ertuğrul, Seyit; Sayar, Alperen; Çakar, Tuna; Çakar,Tuna; Ertuğru, Seyit; 02.02. Department of Computer Engineering; 02. Faculty of Engineering; 01. MEF UniversityThis study investigated the behavioural and cognitive predictors of consumer credit usage to develop a behavioural credit risk assessment procedure for a factoring company. Participants completed surveys measuring personality traits, self-esteem, material and monetary values, compulsive and impulsive buying tendencies, self-control, and impulsiveness. Financial surveys also assessed financial literacy and knowledge of financial concepts. The results indicated that extraversion, conscientiousness, emotional stability, and experiential self-control were significant predictors of consumer credit usage. These findings suggest that a finance company can use these personality traits and financial characteristics to develop a more accurate and effective credit risk assessment procedure, such as psychometric tests. © 2024, Sosyoekonomi Society. All rights reserved.Article Ön Eğitimli Dil Modelleriyle Duygu Analizi(İstanbul Sabahattin Zaim Üniversitesi Fen Bilimleri Enstitüsü, 2023) Demir, Şeniz; Demir, Şeniz; 02.02. Department of Computer Engineering; 02. Faculty of Engineering; 01. MEF UniversityDuygu analizi, çeşitli platformlarda bir konu hakkında düşünce, duygu ya da tutumu irdelemek, analiz etmek ve yorumlamak amacıyla kullanılan yöntemlerden biridir. Farklı konulardaki metinlerin öznel içeriklerine göre sınıflandırılabildiği duygu analizinde makine öğrenmesi ve derin öğrenme modellerinden sıklıkla faydalanılmaktadır.Bu çalışmada, önceden eğitilmiş dil modellerinden yararlanılarak Covid-19 tweet metinleri üzerinde duygu analizi yapılmıştır. Naive Bayes sınıflandırıcıya ek olarak BERT, RoBERTa ve BERTweet dil modelleri kullanılarak farklı sınıflandırıcılar eğitilmiş ve tweet veri kümesi üzerinde elde edilen sonuçlar kıyaslanmıştır. Bildiride aktarılan çalışmanın ileride bu alanda yürütülecek araştırmalara bir zemin oluşturacağı öngörülmektedir.Article Performing Disc Personal Inventory Analysis in Job Postings Using Artificial Intelligence Methods(Data science and applications, 2023) Sayar, Alperen; Çakar, Tuna; Çakar, Tuna; Şengüloğlu, Dilara; Ertuğrul, Seyit; 02.02. Department of Computer Engineering; 02. Faculty of Engineering; 01. MEF UniversityOne of the application fields of DISC selfevaluation analysis was introduced to predict people's performance and orientation in their working life. Each letter in the word DISC represents an essential personal characteristic, dividing the profiles of people in business life into four essential parts. In the current study, DISC analysis is conducted on job postings to match the person with the job posting. The current study was based on the analysis of 3 different datasets with job postings in English, Turkish and Romanian prepared by using web scraping methods and then labeled in accordance with DISC criteria. Several different machine learning algorithms have been performed on the DISC analysis outputs, and they reached the best results with accuracy values of around over 96% on the English dataset, around over 95% on the Turkish dataset, and around over 96% on the Romanian dataset, for both D, I, S, C models.Article Citation - WoS: 4Citation - Scopus: 8Unraveling Neural Pathways of Political Engagement: Bridging Neuromarketing and Political Science for Understanding Voter Behavior and Political Leader Perception(Frontiers Media SA, 2023) Çakar, Tuna; Filiz, Gözde; Çakar, Tuna; 02.02. Department of Computer Engineering; 02. Faculty of Engineering; 01. MEF UniversityPolitical neuromarketing is an interdisciplinary field that combines marketing, neuroscience, and psychology to understand voter behavior and political leader perception. This interdisciplinary field offers novel techniques to understand complex phenomena such as voter engagement, political leadership, and party branding. This study aims to understand the neural activation patterns of voters when they are exposed to political leaders using functional near-infrared spectroscopy (fNIRS) and machine learning methods. We recruited participants and recorded their brain activity using fNIRS when they were exposed to images of different political leaders. This neuroimaging method (fNIRS) reveals brain regions central to brand perception, including the dorsolateral prefrontal cortex (dlPFC), the dorsomedial prefrontal cortex (dmPFC), and the ventromedial prefrontal cortex (vmPFC). Machine learning methods were used to predict the participants' perceptions of leaders based on their brain activity. The study has identified the brain regions that are involved in processing political stimuli and making judgments about political leaders. Within this study, the best-performing machine learning model, LightGBM, achieved a highest accuracy score of 0.78, underscoring its efficacy in predicting voters' perceptions of political leaders based on the brain activity of the former. The findings from this study provide new insights into the neural basis of political decision-making and the development of effective political marketing campaigns while bridging neuromarketing, political science and machine learning, in turn enabling predictive insights into voter preferences and behaviorPatent Artificial Intelligence Augmented Iterative Product Decoding(2023) Arslan , Şuayb Şefik; Göker, TurguyA method for product decoding within a data storage system includes receiving data to be decoded within a first decoder; performing a plurality of decoding iterations to decode the data utilizing a first decoder and a second decoder; and outputting fully decoded data based on the performance of the plurality of decoding iterations. Each of the plurality of decoding iterations includes (i) decoding the data with the first decoder operating at a first decoder operational mode to generate once decoded data; (ii) sending the once decoded data from the first decoder to the second decoder; (iii) receiving error information from the first decoder with an artificial intelligence system; (iv) selecting a second decoder operational mode based at least in part on the error information that is received by the artificial intelligence system; and (v) decoding the once decoded data with the second decoder operating at the second decoder operational mode to generate twice decoded data; and outputting fully decoded data based on the performance of the plurality of decoding iterations.