• Title/Summary/Keyword: Depot

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Application of Genetic Algorithms to Optimize the Storage Location of Products in Military Logistics (군(軍) 물류창고 내(內) 물품 저장위치 최적화를 위한 유전알고리즘 적용 방안)

  • Ha, Won Yong;Cho, Ki-yang;Han, Chung Sik
    • Journal of the Korea Institute of Military Science and Technology
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    • v.25 no.1
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    • pp.108-116
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    • 2022
  • Supply in military operations has a significant impact on overall combat capability and efficiency. Therefore, modernization of military logistics is underway to ensure rapid and accurate distribution. And, effective warehouse management is paramount. This paper proposes a new product allocation model that uses a genetic algorithm. The model considers order frequency and mass of products because the military equipment is usually heavier than available products. A computer simulation shows that products are assigned to optimal locations and reduce the consumed energy for forklifts by more than 25 % with similar travel time. Also, we show the superiority of genetic algorithm by comparing them with other algorithms.

A Study of Solving the Generalized Vehicle Routing Problem Using Reinforcement Learning (강화학습 기반의 차량 경로 문제 일반화 방안 연구)

  • Jung, Chul-Hwan;Kim, Kwang-Su;Kim, Han-Sol
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2022.07a
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    • pp.705-707
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    • 2022
  • 본 연구에서는 기존 차량 경로 문제(Vehicle Routing Problem)의 범위를 확장시켜 일반화된 차량 경로문제(Generalized Vehicle Routing Problem)를 제시하고, 이 문제를 해결하기 위한 강화학습 모델을 제안한다. 기존의 차량 경로 문제는 depot에서 각 node(또는 각 node에서 depot)의 단방향만 존재해 제한된 문제만을 해결할 수 있었다. 이 한계점을 극복하기 위해 depot을 제외한 모든 node가 서로 연결된 형태의 일반화된 차량 경로 문제를 정의하고 이를 해결하고자 한다. 차량 경로 문제는 NP-hard 문제로 최근에는 강화학습을 이용해 이를 해결하고자 하는 모델이 연구되고 있다. 본 연구에서는 새로 정의한 일반화된 차량 경로 문제를 해결하기 위한 강화학습 모델을 제안한다.

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Repair methods for aging aircraft and application of composite patch repair (노후항공기의 보수 방법 및 복합재 패치보수의 응용)

  • 김위대;김종진
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2002.05a
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    • pp.167-172
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    • 2002
  • During the operation of military aircraft, maintenance is divided into organizational, intermediate and depot maintenance. In the depot maintenance, after removal of major parts and removable doors, damage assessment is performed. Locating damage, charactering the damage and determining its extent, zoning the damage on the part being repaired and re-evaluation of the damaged area after damage removal. Repair joints are classified by bonded joints and bolted joints, depending on joining material. In this paper, repair method in aging aircraft is investigated and the possibility of application of copmposite patch is surveyed.

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An Optimal Algorithm for Repairable-Item Inventory System with Depot Spares (중앙창 재고가 있는 수리가능시스템을 위한 해법)

  • 김종수;신규철
    • Journal of the Korean Operations Research and Management Science Society
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    • v.24 no.3
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    • pp.1-11
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    • 1999
  • We consider the problem of determining the spare inventory level for a multiechelon repairable-item inventory system. Our model extends the previous results to the system which has an inventory at the central depot as well as bases. We develop an optimal algorithm to find spare inventory leveis, which minimize the total expected cost and simultaneously satisfy a specified minimum service rate. The algorithm is tested using problems of various sizes to verify the efficiency and accuracy.

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Greedy Heuristic Algorithm for a Multidepot Aircraft Scheduling and Crew Scheduling Problem (복수모기지의 항공기 운항계획및 승무계획 문제의 발견적 기법)

  • Jang, Byeong-Man;Park, Sun-Dal
    • Journal of Korean Institute of Industrial Engineers
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    • v.11 no.2
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    • pp.155-163
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    • 1985
  • This paper presents a heuristic algorithm for a multidepot aircraft scheduling and crew scheduling with deal-head flights. This algorithm is extended from a Greedy heuristic algorithm for a multi-depot multi-salesman traveling salesman problem. We first transform a given flight schedule into a multi-depot multi-traveling salesman problem, considering aircraft flight policies and crew management constraints. Then we solve this problem by applying a modified Greedy heuristic algorithm.

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A Three-Echelon Inventory Model for Repairable Items with Capacity Constraint (수리용량의 제한이 있는 수리가능한 부품의 3단계 재고시스템에 관한 연구)

  • 김지승
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.20 no.43
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    • pp.99-107
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    • 1997
  • We consider a multiechelon repairable-item inventory system where several bases are supported by a central depot and the external repair facilities. Unlike METRIC- based models, there are only a finite number of repair channels at each base, central depot and the external repair facilities. It is desired to find repair capacities and spares level which together guarantee a specified service level at minimum cost. Closed queueing network theory is used to model the stochastic process. The purpose of this paper is to derive the steady-state distributions of this system.

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Study for Optimized Depot System of Train Monitoring System (철도차량 모니터 장치의 지상장치 최적화 기법에 관한 연구)

  • 주해진;한정수;박성호;홍구선
    • Proceedings of the KSR Conference
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    • 2002.10a
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    • pp.497-502
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    • 2002
  • TGIS(Train General Information System) is monitoring Train status and analyzing fault happened. TGIS informed a lot of Passenger data, Driving data, Status data and Fault data to 'Depot'. For dealing them more properly, TGIS need specified data and specialized data handling method. This paper suggest Optimize data of Train Monitoring System and Apply that to Main Line Car.

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Investigation of Soil Pollution Status for Railroad Depot (철도 차량기지의 토양오염 실태 조사)

  • Oa, Seong-Wook;Lee, Tae-Gyu
    • Journal of the Korean Society for Railway
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    • v.12 no.5
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    • pp.788-792
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    • 2009
  • Railroad is well known for eco-friendly transportation system. But, for past few decades, there might be happened many contamination acts in railway facility sites. Industrial and municipal solid wastes produced to maintain and fix trains were dumped to underground of railroad depot area. To develop and reconstruct this area, we should remediate the contaminated soil and ground water. This study was conducted to evaluate the soil pollution status of railroad depot and propose the optimum remediation processes. Our investigation showed that main pollutants sources were TPH and some heavy metals from the dump site. The surveying results for the soil under rail track and crossing nose areas showed TPH contamination from crossing nose area causing lubricant agent. It could be use and rehabilitate the railroad facility areas to an intended purpose with an application of well designed in-situ and ex-situ remediation processes.

Research on RAM-C-based Cost Estimation Methods for the Supply of Military Depot Maintenance PBL Project (군직 창정비 수리부속 보급 PBL 사업을 위한 RAM-C 기반 비용 예측 방안 연구)

  • Junho Park;Chie Hoon Song
    • Journal of the Korean Society of Industry Convergence
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    • v.26 no.5
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    • pp.855-866
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    • 2023
  • With the rapid advancement and sophistication of defense weapon systems, the government, military, and the defense industry have conducted various innovative attempts to improve the efficiency of post-logistics support(PLS). The Ministry of Defense has mandated RAM-C(Reliability, Availability, and Maintainability-Cost) analysis as a requirement according to revised Total Life Cycle System Management Code of Practice in May 2022. Especially, for the project budget forecast of new PBL(Performance Based Logistics) business contacts, RAM-C is recognized as an obligatory factor. However, relevant entities have not officially provided guidelines or manuals for RAM-C analysis, and each defense contractor conducts RAM-C analysis with different standards and methods to win PBL-related business contract. Hence, this study aims to contribute to the generalization of the analysis procedure by presenting a cost analysis case based on RAM-C for the supply of military depot maintenance PBL project. This study presents formulas and procedures to determine requirements of military depot maintenance PBL project for repair parts supply. Moreover, a sensitivity analysis was conducted to find the optimal cost/utilization ratio. During the process, a correlation was found between supply delay and total cost of ownership as well as between cost variability and utilization rate. The analysis results are expected to provide an important basis for the conceptualization of the cost analysis for the supply of military depot maintenance PBL project and are capable of proposing the optimal utilization rate in relation to cost.

Vibration Reduction for a Railway Depot Building (II): Design Parameters (철도인공대지에 건설된 아파트의 방진대책(II): 설계변수)

  • Kim, Jeung Tae
    • Journal of the Korean Society for Railway
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    • v.16 no.5
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    • pp.358-364
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    • 2013
  • In the second part of the paper, a design strategy for an apartment complex constructed at a railway depot is proposed for vibration reduction purposes. Various design parameters such as the vehicle operating speeds, artificial land behavior, housing support structure, and apartment sub-structures are individually examined to reduce the transmission of vibrations through building structures. Building construction on an artificial land should be subjected to regulations that require the application of a vibration reduction scheme based on the mechanics that govern the vibration transmission phenomena. The implementation of these parameters at an early design stage will provide a quiet living environment for residents who may be exposed to excessive noise and vibration.