• Industrial Engineering and Management Systems
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• v.13 no.3
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• pp.319-329
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• 2014

Supply chain management is a subject that has an increasing importance due to the developments in the global markets and technology. In this paper, a fuzzy multi-objective linear programming model is developed for the supply chain of a company dealing with procurement, storage, filling, and distribution of liquefied petroleum gas (LPG) in Turkey. The model intends to determine the quantities of LPG to be procured, stored, filled to cylinders, and transported between the plants and demand centers for six planning periods. In this model, which aims to minimize both total costs (sum of procurement, storage, filling, and transportation costs) and total transportation distances, demand quantities of the main demand centers and decision maker's aspiration levels about objective functions are fuzzy. After comparing the results obtained from the model with those obtained by using different methods, it is concluded that the proposed method can be applied to real world problems practically and it may be used in this type of problems in order to generate an efficient solution.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1993.04a
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• pp.36-45
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• 1993

This paper presents a model and a heuristic procedure to design production planning and transportation scheduling systems of critical items, components and products on the basis of material requirement planning concept and transportation planning model. These systems are stemmed from a multi-site multi-product production company in a international economic zone. An example is provided to validate the heuristic procedure developed.

• Proceedings of the KIPE Conference
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• 2019.07a
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• pp.317-319
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• 2019

In this paper, a three level duty cycle controlled half bridge LLC converter for EV charger application is presented. The topology and operating regions of the converter are discussed. The equations of the converter are derived in time domain. A small signal model of the converter is developed by perturbation and linearization of the steady state model about their operating point using Extended Describing function.

• Journal of Korean Port Research
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• v.12 no.1
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• pp.47-53
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• 1998

Presently, it was faced with serious social problems as traffic accident, parking violation & traffic congestion due to change of industrial structure, expansion of economic volume, elevation of national life level and rapid motorization. Accordingly, the study is research to improve immidiate transportation problems which could be establish the rating model about consideration degree of evaluation factor based on MDPREF's method in connection with Intelligent Transportation System(ITS)

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.922-925
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• 2008

Many highway projects are under way in Korea. However, owners frequently find that the project cost exceeds the budget and they are unable to identify the underlining reasons. The main purpose of this research is to develop cost models for transportation projects in Korea using the multiple linear regression (MLR). The data consist of 27 completed transportation projects, built from 1991 to 2001, The technique of multiple regression analysis is used to develop the parametric cost estimating model for total budget cost per highway square meter (TBC/$m^2$). Findings of the study indicated that MLR car be applied to highway projects in Korea. There are twf) major contributions of this research. (1) the identification of transportation parameters as a significant cost driver for transportation costs and (2) the successful development of the parametric cost estimating models for transportation projects in Korea.

• IE interfaces
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• v.20 no.4
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• pp.525-538
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• 2007

The importance of efficient container transportation becomes more significant each year due to the constant growth of the global marketplace, and studies focusing on shipping efficiency are becoming increasingly important. In this paper, we propose an approach for vehicle scheduling that decreases the number of vehicles required for freight commerce by analyzing and scheduling optimal routes. Container transportation can be classified into round and single-trip transportation, and each vehicle can be linked in a specific order based on the vehicle state after completing an order. We develop a mathematical model to determine the required number of vehicles with optimal routing, and a heuristic algorithm to perform vehicle scheduling for many orders in a significantly shorter duration. Finally, we tested some numerical examples and compared the developed model and the heuristic algorithm. We also developed a decision support system that can schedule vehicles based on the heuristic algorithm.

• Steel and Composite Structures
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• v.45 no.1
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• pp.133-145
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• 2022

Steel fiber composite bar (SFCB) is a novel type of reinforcement, which has good ductility and durability performance. Due to the unique pseudo strain hardening tensile behavior of SFCB, different flexural behavior is expected of SFCB reinforced concrete (SFCB-RC) beams from traditional steel bar reinforced concrete (S-RC) beams and FRP bar reinforced concrete (F-RC) beams. To investigate the flexural behavior of SFCB-RC beam, four points bending tests were carried out and different flexural behaviors between S/F/SFCB-RC beams were discussed. An flexural analytical model of SFCB-RC beams is proposed and proved by the current and existing experimental results. Based on the proposed model, the influence of the fiber volume ratio R of the SFCB on the flexural behavior of SFCB-RC beams is discussed. The results show that the proposed model is effective for all S/F/SFCB-RC flexural members. Fiber volume ratio R is a key parameter affecting the flexural behavior of SFCB-RC. By controlling the fiber volume ratio of SFCB reinforcements, the flexural behavior of the SFCB-RC flexural members such as bearing capacity, bending stiffness, ductility and repairability of SFCB-RC structures can be designed.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.11
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• pp.166-174
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• 2016

In this paper, we developed a mixed-integer linear programming model for transportation planning of athletes in sports events. The transportation planning of athletes involves finding the lowest-cost and fastest-time plan for distributing athletes from multiple accommodation to stadium. The decision variables associate with the number of driving events, and the total transportation cost is the objective function that needs to be minimized. The proposed method uses mixed integer linear programming to solve transportation problem, thus the global optimality is guaranteed. In order to verify the effectiveness of proposed method, we performed simulation and built the sports event management service platform (SEMSP) for transportation planning.

• Journal of Korean Society of Transportation
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• v.35 no.6
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• pp.481-498
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• 2017

Travel time reduction benefit is the most important benefit item in the feasibility study of transportation infrastructure investment projects and calculated by using the value of travel time. The current feasibility study guideline (5th edition) calculate the value of non-business ravel time in a metropolitan area, using the ratio of the value of non-business travel time to business travel time calculated based on the nationwide inter-regional traffic survey data of 1999. The characteristics of metropolitan trips are different from those of nationwide regional trips. Metropolitan trips have frequent transfers between multiple public transits and long-time commuter trips. Therefore, this research aims to calculate the value of travel time reflecting traffic characteristics in a metropolitan area by improving the limitation of current calculation methods. To reflect these characteristics, this research extracts commuter trips from non-business trips and calculates the value of travel time for commuter trips. The results of the likelihood ratio test for the commuter trip model and the non-business trip model are found to be statistically significant. An integrated public transportation model was also estimated in this study to reflect the trip conditions of the Seoul metropolitan area integrated fare system. The results of comparing coefficients between bus and subway in the integrated public transit model indicated that there were no statistically significant differences between the two modes.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2018.05a
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• pp.45-46
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• 2018