1,720,962 research outputs found
A Two-Phase Pattern Generation and Production Planning Procedure for the Stochastic Skiving Process
No full textAltay, Ayca/0000-0001-6066-5336; Samanlioglu, Funda/0000-0003-3838-8824The stochastic skiving stock problem (SSP), a relatively new combinatorial optimization problem, is considered in this paper. The conventional SSP seeks to determine the optimum structure that skives small pieces of different sizes side by side to form as many large items (products) as possible that meet a desired width. This study studies a multiproduct case for the SSP under uncertain demand and waste rate, including products of different widths. This stochastic version of the SSP considers a random demand for each product and a random waste rate during production. A two-stage stochastic programming approach with a recourse action is implemented to study this stochastic NP-hard problem on a large scale. Furthermore, the problem is solved in two phases. In the first phase, the dragonfly algorithm constructs minimal patterns that serve as an input for the next phase. The second phase performs sample-average approximation, solving the stochastic production problem. Results indicate that the two-phase heuristic approach is highly efficient regarding computational run time and provides robust solutions with an optimality gap of 0.3% for the worst-case scenario. In addition, we also compare the performance of the dragonfly algorithm (DA) to the particle swarm optimization (PSO) for pattern generation. Benchmarks indicate that the DA produces more robust minimal pattern sets as the tightness of the problem increases
A Bicriteria Model to Determine Pareto Optimal Pulse Vaccination Strategies
No full textKARACA, TOLGA KUDRET/0000-0001-5562-6367; Samanlioglu, Funda/0000-0003-3838-8824The aim of this paper is to determine approximate Pareto optimal (efficient) pulse vaccination strategies for epidemics modeled by the susceptible-infected-removed (SIR) without population dynamics, characterized by a single epidemic wave. Pulse vaccination is the application of the vaccination campaign over a limited time interval, by vaccinating susceptible individuals at a constant vaccination rate. A pulse vaccination strategy includes the determination of the beginning date and duration of the campaign and the vaccination rate. SIR with vaccination (SIRV) epidemic model is applied during pulse vaccination campaign, resulting in final proportions of removed (Rf) and vaccinated (Vf) individuals at the end of the epidemic. The burden of the epidemic is estimated in terms of Rf and Vf; two criteria are simultaneously minimized: vaccination cost and treatment cost of infected individuals and other economic losses due to sickness that are assumed to be proportional to Vf and Rf, respectively. To find approximate efficient solutions to this bicriteria problem, ODE and genetic algorithm toolboxes of MATLAB are integrated (GA-ODE). In GA-ODE, an augmented weighted Tchebycheff program is used as the evaluation function, calculated by solving the SIRV model and obtaining Rf and Vf values. Sample approximate efficient vaccination strategies are determined for diseases with a basic reproduction number (R0) 1.2 to 2.0. Consequently, obtained strategies are characterized as short-period campaigns that start as early as possible, i.e., as soon as vaccines are available and the vaccination rate increases with the severity of the disease (R0) and the importance weight given to minimization of Rf.Kadir Has University [2017-BAP-16]; Kadir Has University, Istanbul, TurkeyThis research was supported by Kadir Has University, Istanbul, Turkey [2017-BAP-16].Emerging Sources Citation Inde
A Hybrid Interactive Random-Key Genetic Algorithm for a Symmetric Multi-objective Traveling Salesman Problem
No full textPredicting and Optimizing the Fair Allocation of Donations in Hunger Relief Supply Chains
No full textSamanlioglu, Funda/0000-0003-3838-8824Non-profit hunger relief organizations primarily depend on donors' benevolence to help alleviate hunger in their communities. However, the quantity and frequency of donations they receive may vary over time, thus making fair distribution of donated supplies challenging. This paper presents a hierarchical forecasting methodology to determine the quantity of food donations received per month in a multi-warehouse food aid network. We further link the forecasts to an optimization model to identify the fair allocation of donations, considering the network distribution capacity in terms of supply chain coordination and flexibility. The results indicate which locations within the network are under-served and how donated supplies can be allocated to minimize the deviation between overserved and underserved counties. (c) 2024 International Institute of Forecasters. Published by Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.National Science Foundation, NSF, (CNS 2100855, TI-2234598)NSF EiR: Human Centered Visual Analytics for Evidence Based Decision Making in Humanitarian Relief [CNS 2100855]; NSF Partnerships for Innovation: A Smart Food Distribution System for Allocating Scarce Resources Under Extreme Events [TI-2234598]We would like to thank the anonymous referees whose helpful comments greatly improved the presentation of this manuscript. This research is partially funded by NSF EiR: Human Centered Visual Analytics for Evidence Based Decision Making in Humanitarian Relief (Award No.: CNS 2100855) and NSF Partnerships for Innovation: A Smart Food Distribution System for Allocating Scarce Resources Under Extreme Events (Award No. TI-2234598).Social Science Citation Inde
Development of a Transportation Scheduling Algorithm for the Reallocation of Parts Prompted by Schedule Changes
No full textA Multi-Criteria Decision Making Approach to Feedstock Selection
Full text linkSelection of the appropriate feedstock for biodiesel production, taking into consideration several potentially conflicting quantitative and qualitative criteria, is a complex multiple-criteria decision making (MCDM) problem that requires an extensive evaluation process of a group of decision makers (DMs). In this paper, as the MCDM method, fuzzy Analytic Hierarchy Process (F-AHP) and fuzzy Technique for Order Preference by Similarity to Ideal Solution (F-TOPSIS) methods are integrated to evaluate plant based feedstock alternatives for biodiesel production in Turkey. The F-AHP method is used to determine the importance weights of criteria, and the F-TOPSIS method is implemented to evaluate and rank feedstock alternatives with respect to a set of qualitative and quantitative benefit criteria. More specifically, in this paper, plant based feedstocks in Turkey: Sunflower, peanut, cottonseed, canola, safflower, soybean, and poppy seed are evaluated and ranked by decision makers (DMs) with respect to several benefit criteria: Price adequacy, suitability of the plant to the climate and environment, benefits of the plant after processing (the sediment), suitability of the feedstock for technological processing, and yield efficiency, implementing the integrated fuzzy AHP-TOPSIS method
Ranking Willingness To Reuse Water in Cotton Irrigation With Hybrid Mcdm Methods: Soke Plain Case Study
No full textSamanlioglu, Funda/0000-0003-3838-8824Soke Plain, located within the B & uuml;y & uuml;k Menderes River Basin is one of the highest producers of cotton in T & uuml;rkiye. The overall irrigation water supply is based on scarce conventional water resources that are being depleted at an increasing pace due to climate change impacts in B. Menderes. The inclusive objective of this research is to pave the way for a "water efficiency action plan" incorporating non-conventional (alternative) water resources for irrigation in Soke Plain to address adaptive management. Integrated Water Resources Management (IWRM) principles help decision makers (DMs) to identify and apply the most adequate alternatives among other possible ones in resource planning processes. Therefore, the preference ranking of DMs among possible water resource alternatives for irrigation is vital for implementation. This paper marks the first instance of using a multi-criteria decision-making (MCDM) method to evaluate both conventional and non-conventional water resource alternatives for cotton irrigation. The evaluation and ranking of water resource alternatives is processed using the hybrid MCDM method, integration of "Hesitant Fuzzy-Analytic Hierarchy Process" (HF-AHP) and "Hesitant Fuzzy Evaluation based on Distance from Average Solution" (HF-EDAS), namely HF-AHP-EDAS. This procedure implies several possibly contradictory qualitative and quantitative criteria, incorporates ambiguity, vagueness, and hesitancy in decision-makers' decisions, and achieves a consistent, dependable ranking of alternatives. Eight different water resources for irrigation are evaluated by 5 experts, for 15 assessment criteria, in Soke Plain. Conventional water resources blended with drainage water is concluded to be the best irrigation water resource alternative, with HF-AHP-EDAS and also with HF-AHP-PROMETHEE II (Preference Ranking Organization Method for Enriching Evaluations II), that is used for comparison analysis. This choice aligns well with the outlined arguments, culminating in an overall result deemed compliant with the field survey.German Federal Ministry of Education and Research [FKZ02WGR1422E]; Istanbul University Technology Transfer Application and Research Centre, Turkey; Istanbul University's Coordination Unit of Scientific Research ProjectsThis work is a follow-up of the InoCottonGROW-Soke project (project number FKZ02WGR1422E) which was supported by the German Federal Ministry of Education and Research, with the contribution of Istanbul University Technology Transfer Application and Research Centre, Turkey as a project partner.The authors wish to thank the Istanbul University's Coordination Unit of Scientific Research Projects for its financial support to the article processing charge. The authors also wish to thank the anonymous reviewers for their constructive comments, suggestions and positive feedback.Science Citation Index Expande
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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