Endüstri Mühendisliği Bölümü Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.11779/1942

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Qubo Formulations and Characterization of Penalty Parameters for the Multi-Knapsack Problem
(IEEE-Inst Electrical Electronics Engineers Inc, 2025) Guney, Evren; Ehrenthal, Joachim; Hanne, Thomas
The Multi-Knapsack Problem (MKP) is a fundamental challenge in operations research and combinatorial optimization. Quantum computing introduces new possibilities for solving MKP using Quadratic Unconstrained Binary Optimization (QUBO) models. However, a key challenge in QUBO formulations is the selection of penalty parameters, which directly influence solution feasibility and algorithm performance. In this work, we develop QUBO formulations for two MKP variants-the Multidimensional Knapsack Problem (MDKP) and the Multiple Knapsack Problem (MUKP)-and provide an algebraic characterization of their penalty parameters. We systematically evaluate their impact through quantum simulation experiments and compare the performance of the two leading quantum optimization approaches: Quantum Approximate Optimization Algorithm (QAOA) and quantum annealing, alongside a state-of-the-art classical solver. Our results indicate that while classical solvers remain superior, careful tuning of penalty parameters has a strong impact on quantum optimization outcomes. QAOA is highly sensitive to parameter choices, whereas quantum annealing produces more stable results on small to mid-sized instances. Further, our results reveal that MDKP instances can maintain feasibility at penalty values below theoretical bounds, while MUKP instances show greater sensitivity to penalty reductions. Finally, we outline directions for future research in solving MKP, including adaptive penalty parameter tuning, hybrid quantum-classical approaches, and practical optimization strategies for QAOA, as well as real-hardware evaluations.
Citation - WoS: 1
Facial Emotion Recognition Using Residual Neural Networks
(2024) Kırbız, Serap
Facial emotion recognition (FER) has been an emerging research topic in recent years. Recent automatic FER systems generally apply deep learning methods and focus on two important issues: lack of sufficient labeled training data and variations in images such as illumination, pose, or expression-related variations among different cultures. Although Convolutional Neural Networks (CNNs) are widely used in automatic FER, they cannot be used when the number of layers is large. Therefore, a residual technique is applied to CNNs and this architecture is named residual neural network. In this paper, an automatic facial emotion recognition method using residual networks with random data augmentation is proposed on a merged FER dataset consisting of 41,598 facial images of size 48 × 48 pixels from seven basic emotion classes. Experimental results show that ResNet34 with data augmentation performs better than CNN with a classification accuracy of 81%.
Citation - Scopus: 1
Interval Valued Intuitionistic Fuzzy Z Extensions of Ahp&codas: Comparison of Energy Storage Alternatives
(Springer, 2023) Sergi, Duygu; Sarı, İrem Uçal
Energy storage technologies are receiving increasing attention due to the trend toward renewable energy sources. Energy storage systems are a promising technology as they provide the low carbon emissions needed in the future, contribute to renewable energy production, and offer an alternative to petroleum-derived fuels. It is not possible to say precisely how the energy will be stored, and often more than one method must be used together. In this study, battery technologies from electrochemical energy storage systems are discussed. This chapter proposes a multi-criteria decision-making (MCDM) model combining fuzzy IVIF-Z-AHP and fuzzy IVIF-Z-CODAS methods to choose the optimal battery ESS. The priority weights of 4 main and 11 sub-criteria related to energy storage efficiency are determined using the IVIF-Z-AHP method. After that, 5 different batteries are evaluated using the IVIF-Z-CODAS method, and the most appropriate battery ESS is selected by doing a performance evaluation regarding the storage of energy at maximum efficiency.
Citation - WoS: 1
Citation - Scopus: 1
Evaluation of Learning Management Systems Using Interval Valued Intuitionistic Fuzzy-Z Numbers
(Anadolu Üniversitesi, 2023) Ucal Sarı, İrem; Sergi, Duygu
The use of online education tools has increased rapidly with the transition to distance education caused by the pandemic. The obligation to carry out all activities of face-to-face education online made it very important for the tools used in distance education to meet the increasing needs. In line with these needs, radical changes have occurred in the learning management systems used in distance education. Therefore, in this study, it is aimed to determine the features that the systems used in distance education should have and to compare the existing systems according to these features. For this purpose, a novel fuzzy extension, interval valued intuitionistic fuzzy Z-numbers, is defined for modeling uncertainty, and AHP and WASPAS methods using proposed fuzzy numbers are developed to determine the importance of decision criteria and compare alternatives.
Dialogue Enhancement Using Kernel Additive Modelling
(Institute of Electrical and Electronics Engineers Inc., 2015) Liutkus, A.; Kırbız, Serap; Cemgil, A. Taylan
It is a major problem for the sound engineers to find the right balance between the dialogue signals and the ambient sources. This problem also makes one of the main causes of the audience concerns. The audience wants to arrange the sound balance based on their personal preferences, listening environment and their hearing. In this work, a method is proposed for enhancing the dialogue signals in stereo recordings that consist of more than one source. The kernel additive modelling that has been used successfully in sound source separation is used to extract the dialogues and the ambient sources from the movie sounds. The separated dialogue and ambient sources can later be upmixed by the user to make a personal mix. The separation performance of the proposed method is evaluated on the sounds generated by mixing the sources which were taken from the only dialogue and only music parts of the movies. It has been shown that the Kernel Additive Modelling (KAM) based method can be successfully used for dialogue enhancement. © 2015 IEEE.
Citation - WoS: 1
Citation - Scopus: 1
A Decomposition Algorithm for Single and Multiobjective Integrated Market Selection and Production Planning
(Informs, 2023) van den Heuvel, Wilco; Ağralı, Semra; Taşkın, Z. Caner
We study an integrated market selection and production planning problem. There is a set of markets with deterministic demand, and each market has a certain revenue that is obtained if the market's demand is satisfied throughout a planning horizon. The demand is satisfied with a production scheme that has a lot-sizing structure. The problem is to decide on which markets' demand to satisfy and plan the production simultaneously. We consider both single and multiobjective settings. The single objective problem maximizes the profit, whereas the multiobjective problem includes the maximization of the revenue and the minimization of the production cost objectives. We develop a decomposition-based exact solution algorithm for the single objective setting and show how it can be used in a proposed three-phase algorithm for the multiobjective setting. The master problem chooses a subset of markets, and the subproblem calculates an optimal production plan to satisfy the selected markets' demand. We investigate the subproblem from a cooperative game theory perspective to devise cuts and strengthen them based on lifting. We also propose a set of valid inequalities and preprocessing rules to improve the proposed algorithm. We test the efficacy of our solution method over a suite of problem instances and show that our algorithm substantially decreases solution times for all problem instances.
Citation - WoS: 6
Citation - Scopus: 11
Mixcycle: Unsupervised Speech Separation Via Cyclic Mixture Permutation Invariant Training
(IEEE, 2022) Karamatlı, Ertuğ; Kırbız, Serap
We introduce two unsupervised source separation methods, which involve self-supervised training from single-channel two-source speech mixtures. Our first method, mixture permutation invariant training (MixPIT), enables learning a neural network model which separates the underlying sources via a challenging proxy task without supervision from the reference sources. Our second method, cyclic mixture permutation invariant training (MixCycle), uses MixPIT as a building block in a cyclic fashion for continuous learning. MixCycle gradually converts the problem from separating mixtures of mixtures into separating single mixtures. We compare our methods to common supervised and unsupervised baselines: permutation invariant training with dynamic mixing (PIT-DM) and mixture invariant training (MixIT). We show that MixCycle outperforms MixIT and reaches a performance level very close to the supervised baseline (PIT-DM) while circumventing the over-separation issue of MixIT. Also, we propose a self-evaluation technique inspired by MixCycle that estimates model performance without utilizing any reference sources. We show that it yields results consistent with an evaluation on reference sources (LibriMix) and also with an informal listening test conducted on a real-life mixtures dataset (REAL-M).
Citation - WoS: 5
Citation - Scopus: 9
Predicting Cash Holdings Using Supervised Machine Learning Algorithms
(Springer, 2022) Özlem, Şirin; Tan, Ömer Faruk
This study predicts the cash holdings policy of Turkish firms, given the 20 selected features with machine learning algorithm methods. 211 listed firms in the Borsa Istanbul are analyzed over the period between 2006 and 2019. Multiple linear regression (MLR), k-nearest neighbors (KNN), support vector regression (SVR), decision trees (DT), extreme gradient boosting algorithm (XGBoost) and multi-layer neural networks (MLNN) are used for prediction. Results reveal that MLR, KNN, and SVR provide high root mean square error (RMSE) and low R2 values. Meanwhile, more complex algorithms, such as DT and especially XGBoost, derive higher accuracy with a 0.73 R2 value. Therefore, using advanced machine learning algorithms, we may predict cash holdings considerably.
Citation - WoS: 49
Citation - Scopus: 52
Extension of Capital Budgeting Techniques Using Interval-Valued Fermatean Fuzzy Sets
(IOS Press, 2022) Sergi, Duygu; Sarı, İrem Uçal; Senapati, Tapan
Capital budgeting requires dealing with high uncertainty from the unknown characteristics of cash flow, interest rate, and study period forecasts for future periods. Many fuzzy extensions of capital budgeting techniques have been proposed and used in a wide range of applications to deal with uncertainty. In this paper, a new fuzzy extension of the most used capital budgeting techniques is proposed. In this content, first interval-valued Fermatean fuzzy sets (IVFFS s) are defined, and the algebraic and aggregation operations are determined for interval-valued Fermatean fuzzy (IVFF) numbers. The formulations of IVFF net present value, IVFF equivalent uniform annual value, and IVFF benefit-cost ratio (B/C) methods are generated. To validate the proposed methods, proposed formulations are illustrated with a hypothetical example, and the results are compared with classical fuzzy capital budgeting techniques.
A Lot-Sizing Problem in Deliberated and Controlled Co-Production Systems
(Taylor and Francis, 2021) Kabakulak, Banu; Ağralı, Semra; Taşkın, Z. Caner; Pamuk, Bahadır
We consider an uncapacitated lot sizing problem in co-production systems, in which it is possible to produce multiple items simultaneously in a single production run. Each product has a deterministic demand to be satisfied on time. The decision is to choose which items to co-produce and the amount of production throughout a predetermined planning horizon. We show that the lot sizing problem with co-production is strongly NP-Hard. Then, we develop various mixed-integer linear programming (MILP) formulation of the problem and show that LP relaxations of all MILPs are equal. We develop a separation algorithm based on a set of valid inequalities, lower bounds based on a dynamic lot-sizing relaxation of our problem and a constructive heuristic that is used to obtain an initial solution for the solver, which form the basis of our proposed Branch & Cut algorithm for the problem. We test our models and algorithms on different data sets and provide the results.
Customer Segmentation Using Rfm Analysis: Real Case Application on a Fuel Company
(Emerald Publishing Limited., 2020) Ucal Sarı, İrem; Sergi, Duygu; Ozkan, Burcu
Customer segmentation is an important research area that helps organizations to improve their services according to customer needs. With the increased information that shows customer attitudes, it is much easier and also more necessary than before to analyze customer responses on different campaigns. Recency, frequency, and monetary (RFM) analysis allows us to segment customers according to their common features. In this chapter, customer segmentation and RFM analysis are explained first, then a real case application of RFM analysis on customer segmentation for a Fuel company is presented. At the end of the application part, possible strategies for the company are generated.
Citation - Scopus: 8
Analysis of Intelligent Software Implementations in Air Cargo Using Fermatean Fuzzy Codas Method
(Springer, 2022) Sergi, Duygu; Sarı, İrem Ucal; Kuchta, Dorota
The chapter focuses on the problem of analyzing and selecting intelligent software in Air Cargo in the concept of Aviation 4.0. First, the notions, problems and challenges linked to air cargo are discussed. Recent developments, ongoing innovative projects and unfilled gaps in the area of intelligent air cargo software are presented. Next, the proposed method to analyze a select software to be used by air cargo companies is described. It is a modified version of one of the recent multi-criteria decision-making methods, called CODAS. Its original, crisp version and its existing fuzzy extensions are first presented. Next, an original extension of the method, using Fermatean fuzzy sets, is proposed. In the application section a logistics company is considered, which is facing the problem of selecting software supporting the air cargo process. The criteria are selected by experts holding various positions in the company, and three alternatives of air cargo software provider are determined. Then, the proposed method is applied to solve the intelligent software selection problem. Finally, conclusion and future research perspectives are given.
Müşteri Hizmetleri Bölümünde Süreç Analizi ve Stratejik Planlama- Lastik Sektöründe Bir Uygulama
(Eskişehir Teknik Üniversitesi, 2020) Özuduruk, Semih Faruk; Sergi, Duygu; Sarı, İrem Ucal
Bu çalışma kapsamında, bir işletmenin süreç analizinin yapılması ve sonrasında işletme stratejisinin oluşturulması için gerekli analiz ve stratejik yönetim modelleri incelenmiştir. Daha sonra, işletme geneli için incelenen bu yöntemler, bir işletme özelinde müşteri hizmetleri bölümüne uygulanmıştır. Çalışma kapsamında, öncelikle SWOT analizi ile iş biriminin içinde bulunduğu mevcut durumun özellikleri belirlenmiş, sonrasında oluşturulan Genişletilmiş SWOT matrisi ile ortaya çıkan faktörlere uygun stratejiler belirlenmiştir. Stratejiler belirlendikten sonra İç Faktör Değerlendirme ve Dış Faktör Değerlendirme matrisleri ile SWOT analizinde ortaya konan faktörler ağırlıklandırılarak puanlanmıştır. Oluşturulan puanlar, İç-Dış Faktörler matrisine yerleştirilerek işletmenin bulunduğu stratejik konum tayin edilmiştir. Son aşamada ise, seçilen stratejiye ulaşmak amacı ile Kurumsal Karne (Balanced Scorecard-BSC) yönteminden faydalanılarak oluşturulan stratejik harita üzerinde faktörler arası ilişkiler gösterilmiş ve alt stratejiler belirlenmiştir.
Citation - Scopus: 3
Selection of the Best Face Recognition System for Check in and Boarding Services
(Springer, 2022) Ucal Sarı, İrem; Sergi, Duygu; Kuchta, Dorota
Check-in and boarding services are one of the most human oriented pre-flight services in aviation industry. The process of using face recognition systems increase with the aviation 4.0 concept, decreases need for manpower and increases the efficiency of the processes. Therefore, problems, developments and challenges of face recognition in terms of aviation 4.0 are discussed in this chapter to determine the best face recognition system for check in and boarding systems. Analytic hierarchy process and grey relational analysis are used to analyze current system providers. To handle the ambiguity in the linguistic evaluations, fuzzy Z- numbers are used. 10 face recognition system providers are evaluated according to five criteria with the proposed methodology and the results are discussed. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.
Citation - WoS: 44
Citation - Scopus: 40
Branch-And Methods for the Electric Vehicle Routing Problem With Time Windows
(Taylor and Francis, 2021) Çatay, Bülent; Duman, Ece Naz; Taş, Duygu
In this paper, we address the electric vehicle routing problem with time windows and propose two branch-and-price-and-cut methods based on a column generation algorithm. One is an exact algorithm whereas the other is a heuristic method. The pricing sub-problem of the column generation method is solved using a label correcting algorithm. The algorithms are strengthened with the state-of-the-art acceleration techniques and a set of valid inequalities. The acceleration techniques include: (i) an intermediate column pool to prevent solving the pricing sub-problem at each iteration, (ii) a label correcting method employing the ng-route algorithm adopted to our problem, (iii) a bidirectional search mechanism in which both forward and backward labels are created, (iv) a procedure for dynamically eliminating arcs that connect customers to remote stations from the network during the path generation, (v) a bounding procedure providing early elimination of sub-optimal routes, and (vi) an integer programming model that generates upper bounds. Numerical experiments are conducted using a benchmark data set to compare the performances of the algorithms. The results favour the heuristic algorithm in terms of both the computational time and the number of instances solved. Moreover, the heuristic algorithm is shown to be specifically effective for larger instances. Both algorithms introduce a number of new solutions to the literature.
Citation - Scopus: 1
Determining and Evaluating New Store Locations Using Remote Sensing and Machine Learning
(Tübitak, 2021) Ünsalan, Cem; Turgay, Zeynep Zerrin; Küçükaydın, Hande; Höke, Berkan
Decision making for store locations is crucial for retail companies as the profit depends on the location. The key point for correct store location is profit approximation, which is highly dependent on population of the corresponding region, and hence, the volume of the residential area. Thus, estimating building volumes provides insight about the revenue if a new store is about to be opened there. Remote sensing through stereo/tri-stereo satellite images provides wide area coverage as well as adequate resolution for three dimensional reconstruction for volume estimation. We reconstruct 3D map of corresponding region with the help of semiglobal matching and mask R-CNN algorithms for this purpose. Using the existing store data, we construct models for estimating the revenue based on surrounding building volumes. In order to choose the right location, the suitable utility model, which calculates store revenues, shouldbe rigorously determined. Moreover, model parameters should be assessed as correctly as possible. Instead of using randomly generated parameters, we employ remote sensing, computer vision, and machine learning techniques, which provide a novel way for evaluating new store locations.
Citation - WoS: 30
Citation - Scopus: 36
Prioritization of Public Services for Digitalization Using Fuzzy Z-Ahp and Fuzzy Z-Waspas
(Springer, 2021) Ucal Sarı, İrem; Sergi, Duygu
In this paper, public services are analyzed for implementations of Industry 4.0 tools to satisfy citizen expectations. To be able to prioritize public services for digitalization, fuzzy Z-AHP and fuzzy Z-WASPAS are used in the analysis. The decision criteria are determined as reduced cost, fast response, ease of accessibility, reduced service times, increase in the available information and increased quality. After obtaining criteria weights using fuzzy Z-AHP, health care services, waste disposal department, public transportation, information services, social care services, and citizen complaints resolution centers are compared using fuzzy Z-WASPAS that is proposed for the first time in this paper. Results show that health care services have dominant importance for the digitalization among public services.
Analysis of a New Business Model To Fundraise Non-Governmental Organizations Using Fuzzy Cognitive Maps
(IOS Press, 2020) Aytore, Can; Sergi, Duygu; Ucal Sari, Irema
Fundraising is one of the most critical issues for non-governmental organizations (NGOs) to carry out their projects. In this paper, a search engine project which aims to find additional financial sources and increase donations for NGOs is proposed. The proposed search engine project is analyzed using fuzzy cognitive maps (FCMs) to define and manage factor influences on the success of the project. FCMs are useful tools to define long term effects of important factors for a system. First casual relations of the factors are determined and then using sigmoid function for learning algorithm, the equilibrium state for the system is obtained. It is found that the factors generating monetary values are the most important ones for the project to be successful in long term.
Büyük Ölçekli Etki Enbüyükleme Problemi için Lagrange Gevşetmesi Tabanlı Etkin Bir Çözüm Yöntemi
(AKÜ FEMÜBİD, 2020) Güney, Evren
Etki Enbüyükleme Problemi (EEP) büyük bir sosyal ağ içindeki en etkin K tane kişiyi seçen zor bir stokastik kombinatoryal eniyileme problemidir. Son yıllarda pek çok araştırmacının ilgisini çeken bu problem için çok sayıda etkin yöntem geliştirilmiştir. Sosyal ağdaki bilginin / etkinin yayılımı çeşitli ağ akış modelleri ile tasarlandığında, elde edilen problemin amaç fonksiyonunun alt-birimsel olduğu gözlemlenmiştir. Bu sebeple basit bir açgözlü algoritma ile (1-1/e) en kötü performans garantisine erişilmiştir. Ancak, aç gözlü algoritmanın büyük boyutlu problemlerde çok uzun çözüm süreleri gerektirmesi alternatif yöntem arayışlarına neden olmuştur. Son yıllarda geliştirilen yeni yöntemler genelde büyük boyutlu ağlarda kısa sürede iyi çözümler elde ederken (1-1/e) performans garantisini de korumaktadır. Ancak pek az sayıda çalışma problemin sadece en-iyi çözümüne odaklanmıştır. Bu çalışmada Lagrange gevşetmesi tabanlı ve EEP’yi eniyi / eniyiye yakın çözen ve ölçeklenebilen bir yöntem geliştirilmiştir. Bu çerçevede, öncelikle Örneklem Ortalama Yakınsaması ile özgün probleme yakınsayan belirgin bir matematiksel model kurulmuştur. Daha sonra bu model üzerinde düğüm tabanlı Lagrange gevşetmesi tekniği uygulanmıştır. İlgili yöntem bağımsız çağlayan ve doğrusal eşik bilgi yayılım modelleri varsayımı altında çeşitli boyutlardaki sosyal ağ veri setleri (Facebook, Enron, Gnutella, arXiv) üzerinde test edilmiştir. Bütün senaryolarda eniyi / eniyiye yakın çözümlere ulaşılırken yazındaki mevcut yöntemlere göre on kata kadar hızlanma sağlanmıştır.
Citation - Scopus: 27
Fuzzy Capital Budgeting Using Fermatean Fuzzy Sets
(Springer, 2021) Sergi, Duygu; Sarı, İrem Ucal
Investment projects are mostly evaluated by capital budgeting techniques to measure their profitability. The parameters used in capital budgeting such as future cash flows, interest rate and useful life involves high uncertainty due to the lack of information for the future environment. Since the uncertainty involved in forecasting the parameters is mostly in high levels, fuzzy set theory could be used in the determination of capital budgeting parameters to handle uncertain information in the analyses. Fermatean fuzzy sets are one of the most recent extensions of fuzzy set theory which are capable to handle higher levels of uncertainties by assigning fuzzy parameters from a larger domain. In this paper, fuzzy capital budgeting techniques that are fuzzy net present worth, fuzzy net future worth and fuzzy net annual worth are extended using fermatean fuzzy sets. An illustration for the calculations is also presented.

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