Bilgisayar Mühendisliği Bölümü Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.11779/1940
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Article Effect of Belief in Free Will on the Intensity of Third-Party Punishment(Istanbul University Press, 2025) Çakar, Tuna; Erözden, Ozan; Akyürek, Güçlü; Özen, Zeynep; Şahin, Türkay; Keskin, İrem Nur; Ünlü, Meryem; 02.02. Department of Computer Engineering; 02. Faculty of Engineering; 05. Faculty of Law; 01. MEF UniversityThe institutionalized criminal justice mechanisms are built on two psychological and social traits: third-party punishment (TPP) and belief in free will (BFW). TPP is the administration of a sanction to a transgressor by an individual not affected by the transgression. BFW posits that humans are in control of their actions. Previous studies have indicated that BFW influences TPP. The aim of this study is to investigate whether the level of BFW has an impact on the magnitude of punishment in TPP tasks. Furthermore, it questions whether the degree of affective arousal of the punisher creates an additional effect on the magnitude of the punishment. Our basic hypothesis is that the BFW and punishment magnitude are positively correlated. We also hypothesize that the expected positive correlation between BFW and punishment magnitude will be more manifest in low-affect scenarios than in high-affect ones. Participants (N = 726) were given 49 hypothetical crime scenarios categorized as low- and high-affect cases. Upon reading each scenario, the participants were tasked to attribute a penalty between the two given options. Our results showed that the level of BFW was positively correlated with the degree of punishment administered in the hypothetical crime scenarios and that the average punishment magnitude for participants with a low level of BFW increased in the high-affect crime scenarios. We assume that our results would shed light on the underlying causes of public reactions to criminal sentencing policies, thus helping lawmakers in enacting better regulations in this respect. 2025. Çakar, T., Akyürek, G., Erözden, O., Şahin, T., Keskin, İ. N., Ünlü, M., Özen, D. H. & Özen, Z.Conference Object Citation - WoS: 1Neural Language Generation for a Turkish Task-Oriented Dialogue System(PROCEEDINGS OF THE WORKSHOP ON INTELLIGENT INFORMATION PROCESSING AND NATURAL LANGUAGE GENERATION, 2020) Çakar, Tuna; Demir, Şeniz; Bilgin, Batuhan; Çakar, Tuna; Demir, Şeniz; 02.02. Department of Computer Engineering; 02. Faculty of Engineering; 01. MEF UniversityRapidly growing language and speech-enabled technologies contribute to the development of task-oriented dialogue systems. The demand for better user engagement has been increasing at an accelerating pace and this brings new remarkable challenges including the generation of informative and natural system utterances. In this work, our ultimate goal is to develop a Turkish task-oriented dialogue system that enables users to navigate over a map in order to get informed about dining venues that best match their preferences and make reservations based on received recommendations. This paper presents the pipeline architecture of our dialogue system with a particular focus on the language generator. We utilize an open source framework for building the components of our system and develop a sequence-to-sequence (Seq2Seq) neural model for language generation. This pioneering work is the first that proposes the use of a neural generation model in a Turkish conversational system. Our evaluations suggest that Turkish neural generation from meaning representations given in the form of dialogue acts is effective, but still in need of further improvements.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.Conference Object Rag Based Interactive Chatbot for Video Streaming Services(Institute of Electrical and Electronics Engineers Inc., 2025) Çakar, Tuna; Özlem, Şirin; Kara E.; Yildiz A.; Köseoǧlu O.; Makaroǧlu D.; Çakar T.; Gözükara, Hamza; Patel, Jay; Makaroǧlu, Didem; Kara, Erkan; Yildiz, Ayşenur; Çakar, Tuna; Köseoǧlu, Ozan; 02.01. Department of Industrial Engineering; 02.02. Department of Computer Engineering; 02. Faculty of Engineering; 01. MEF UniversityThe proliferation of content within video streaming services presents a significant challenge for users seeking personalized recommendations and specific information. This research addresses this challenge by developing a Retrieval-Augmented Generation (RAG) chatbotn designed to enhance user experience through conversational AI. The primary contribution of this work is a novel Retrieval-Augmented Generation (RAG) architecture featuring a dual-retrieval system that combines semantic search for descriptive requests and structured queries for fact based inquiries. This approach grounds the Large Language Model (LLM) in a factual knowledge base, mitigating the risk of hallucinations. The system is engineered to handle empty data retrieval scenarios by dynamically relaxing search filters, ensuring a robust user experience. The effectiveness of this RAG approach was validated through a comprehensive set of automated evaluations. The system demonstrates high precision in ranked list retrieval with questions like "Recommend me the top 5 action movies with highest IMDb scores", achieving an average NDCG@k of 0.837. While the chatbot shows strong semantic understanding by achieving 91% accuracy with contextual clues such as "Which Batman movies are directed by Christopher Nolan?", its performance with more ambiguous, plot-only queries (59.5% accuracy) indicates clear opportunities for future refinement. These results confirm that the dual-tool architecture successfully combines the flexibility of semantic search with the precision of structured queries, paving the way for more intuitive and efficient content discovery on streaming platforms. © 2025 IEEE.Conference Object Combining Similar Trajectories and XGBoost via Residual Learning for Traffic Flow Forecasting(Institute of Electrical and Electronics Engineers Inc., 2025) Çakar, Tuna; Yilmaz E.; Arslan I.; Çakar T.; Çakar, Tuna; Işlak, Ümit; Yilmaz, Elif; Arslan, Ilker; 02.02. Department of Computer Engineering; 02. Faculty of Engineering; 01. MEF UniversityIn this study, we propose novel hybrid forecasting models that integrate the method of similar trajectories with machine learning techniques, particularly the XGBoost algorithm, for traffic flow prediction. Traditional statistical models, such as ARIMA, often struggle to accurately capture the complex, non-linear patterns characteristic of traffic flow data. To address these limitations, we develop an additive hybrid forecasting framework that combines the strengths of linear models (similar trajectories method) and non-linear models (XGBoost). Our proposed methods are evaluated on two different stations from the California PEMS dataset. Experimental results demonstrate that the proposed hybrid models consistently outperform individual benchmark models, including ARIMA, standalone similar trajectories, and XGBoost. The superiority of the hybrid approach, particularly the XGBST model, is further validated through the Diebold-Mariano statistical test, confirming significant predictive improvements at various significance levels. Additionally, using weighted Euclidean distance within the similar trajectories method further enhanced forecasting accuracy. The interpretability and flexibility of our hybrid framework make it especially suitable for practical implementation in traffic management systems. These findings underline the effectiveness of hybrid modeling strategies in traffic flow forecasting and suggest future research directions, such as comprehensive hyperparameter optimization and broader validation across diverse datasets. © 2025 IEEE.Conference Object Citation - Scopus: 1The Application of Two Bayesian Personalized Ranking Approaches Based on Item Recommendation From Implicit Feedback(Ieee, 2024) Tagtekin, Burak; Sahin, Zeynep; Çakar, Tuna; Drias, Yassine; 02.02. Department of Computer Engineering; 02. Faculty of Engineering; 01. MEF UniversityThe present study has aimed to provide a different ranking approach that will be used actively in a sector-specific application regarding the optimization of item ranking presented to the users. The current online approach in several different applications still holds a manual ranking algorithm whose parameters are determined by the data specialists with adequate domain-knowledge. The obtained findings from the present study indicate that the optimized Bayesian Personalized Ranking models will be used for providing a suitable, data-driven input for the ranking system that would serve to be personalized. The outcomes of the present study also demonstrate that the model using LearnBPR optimized with a stochastic gradient descent algorithm outperform the other similar methods. The sample model outputs were also investigated by a user sample to ensure that the algorithm was working correctly. The next potential step is to provide a normalization process to include the extracted information to the current ranking system and observe the performance of this new algorithm with the A/B tests conducted.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.Conference Object Analyzing Customer Churn: a Comparative Study of Machine Learning Models on Pay-Tv Subscribers in Turkey(IEEE, 2023) Obalı, Emir; Çakar, Tuna; Karani Yılmaz, Veysel; Kara, Erkan; Meşe, Yasemin Kürtcü; Çakar, Tuna; Yıldız, Ayşenur; Hataş, Tuğce Aydın; 02.02. Department of Computer Engineering; 02. Faculty of Engineering; 01. MEF UniversityUnderstanding the reasons for customer churn provides added value in terms of retaining existing customers, as customer attrition leads to revenue loss for companies and incurs marketing costs for acquiring new customers. In this study, the 6-month historical data of a Pay-TV company operating in Turkey was used, and due to the imbalanced nature of the dataset on a label basis, the oversampling method was applied. During the model development phase, various artificial learning algorithms (Random Forest, Logistic Regression, KNearest Neighbors, Decision Tree, AdaBoost, XGBoost, Extra Tree Classifier) were utilized, and their performances were compared. Based on the evaluation of success criteria for each model, it was observed that the tree-based Random Forest, Extra Tree Classifier and XGBoost achieved the highest performance for this dataset.Conference Object Optimizing Collective Building Management Through a Machine Learning-Based Decision Support System(IEEE, 2023) Güvençli, Mert; Çakar, Tuna; Doğan, Erkan; Çakar, Tuna; Özyürüyen, Burcu; Kiran, Halil; 02.02. Department of Computer Engineering; 02. Faculty of Engineering; 01. MEF UniversityThis study presents the design, implementation, and evaluation of a Decision Support System (DSS) developed for Collective Building Management. Given the potential advantages of machine learning techniques in this domain, the research explores how these techniques can be used to improve collective building management. The dataset consists of 824,932 records and 15 attributes, after preprocessing the data to fill in missing values with the median. The random forest algorithm was chosen for model training and achieved a performance rate of 71.2%. This model can be used to optimize decision processes in collective building management. The proposed prototype is notable for its ability to automatically generate operational plans. In conclusion, machine learning-based DSSs are effective tools for collective building management.Conference Object Fault Detection Model Using Measurement Data in Fiber Optic Internet Lines(IEEE, 2023) Çakar, Tuna; Çakar, Tuna; Battal, Eray; Özkan, Gözde; 02.02. Department of Computer Engineering; 02. Faculty of Engineering; 01. MEF UniversityIn this study, a model has been developed to predict potential faults in advance based on performance metrics of various fiber-optic internet lines, as well as alarm (fault data) and performance measurement values from the 5 hours prior to the occurrence of the alarm. Performance metrics that vary over time have been analyzed in a time-series format based on alarm numbers, and anomaly detection methods have been used to label the data for any potential patterns that may occur in the performance metrics specific to the alarm. The labeled data was then fed into a classification model to create a model that enables to detect possible patterns in the relevant performance values for the specific fault type. The best performing model was Random Forest Classifier with accuracy and F1 scores of 0.89 and 0.84 respectively.