• Title/Summary/Keyword: Safety Stock

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A study on the functional transition of Korean rolling stock's window pane. (한국 철도차량 창호유리의 기능적 변천에 대한 고찰)

  • Lee, Heung-Jae;Chang, Dae-Sung
    • Proceedings of the KSR Conference
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    • 2009.05b
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    • pp.323-337
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    • 2009
  • This paper researched the adiabatic characteristic, safety and sound insulation characteristic of rolling stock window pane type and transition process of korean train vehicle window glass, and also including investigating a hereafter course of development. The window pane have provided the romantic feeling and the external scenery of train travel to the passenger in period of korea 110 year railway history. From the adiabatic viewpoint, this paper reviewed heat conductivity(U-value) and solar factor according to window pane type, including the safety and sound transmission loss of window pane.

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Rolling Stock Passenger Compartment Fire Safety Surveillance System (철도차량 객실화재 안전감시 시스템)

  • Son Young-Jin;Lee Kang-won;Bang yeon-goon
    • Proceedings of the KSR Conference
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    • 2005.05a
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    • pp.58-63
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    • 2005
  • It is an emergency which is in the process of existing using of passenger compartment equipment of the rolling stock to sprout and interphone wiring and by the fire sensor which perceives the smoke in the use passenger car ceiling the receiver which is to driver's cabin it leads and the fire occurrence alarm voice sprouts carried on shoulder but, by no. of the car indication ramp it divides the corresponding vehicle and from inside the passenger compartment of the rolling stock from fire occurrence hour driver's cabin corresponding passenger no. of the car. It is accurate and in order it will be able to perceive. It will be able to confront initially quickly with the technique which it composes. It is regarding the fire safety surveillance system it will be able to embody at the expense which is cheap in order to use existing wiring.

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Inventory Policies for Multi-echelon Serial Supply Chains with Normally Distributed Demands (정규분포를 따르는 다단계 시리얼 공급사슬에서의 재고 정책)

  • Kwon, Ick-Hyun;Kim, Sung-Shick
    • Journal of the Korea Safety Management & Science
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    • v.8 no.3
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    • pp.115-123
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    • 2006
  • The main focus of this study is to investigate the performance of a clark-scarf type multi-echelon serial supply chain operating with a base-stock policy and to optimize the inventory levels in the supply chains so as to minimize the systemwide total inventory cost, comprising holding and backorder costs as all the nodes in the supply chain. The source of supply of raw materials to the most upstream node, namely supplier, is assumed to have an infinite raw material availability. Retailer faces random customer demand, which is assumed to be stationary and normally distributed. If the demand exceeds on-hand inventory, the excess demand is backlogged. Using the echelon stock and demand quantile concepts and an efficient simulation technique, we derive near optimal inventory policy. Additionally we discuss the derived results through the extensive experiments for different supply chain settings.

A study on the axial force and displacement characteristics of turnout on a bridge (분기기와 교량의 상호작용 특성에 관한 연구)

  • Yang, Shin-Chu;Kim, In-Jae;Kim, Eun
    • Proceedings of the KSR Conference
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    • 2006.11b
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    • pp.1306-1311
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    • 2006
  • Most of design parameters of Railway Structures are determined by the serviceability requirements, rather than the structural safety requirements. The serviceability requirements come from Ensuring of Running Safety and Ride Comfort of Train, Reduction of Track Maintenance Work Track-Bridge Interaction should be considered in the design of railway structures. In this study, a numerical method which precisely evaluate an axial force in rail and a rail expansion and contraction when turnout exist in succession on a CWR on a ballasted or on a ballastless track of bridge is developed. From the parameter studies using the developed method, additional stress of stock rail almost 25% is generated due to stock and lead rail interaction, even embankment not bridge. In case of ballasted track, additional stress of stock rail on bridge is very greater than on embankment, and therefore require detailed review in bridge design with turnout. Stresses of turnout rails on bridge are very sensitive according to the installed positions. In case of ballastless track, Stresses of turnout rails are similar as those of normal track

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A Study on Developing an Integrated Model of Facility Location Problems and Safety Stock Optimization Problems in Supply Chain Management (공급사슬관리에서 생산입지선정 문제와 안전재고 최적화 문제의 통합모형 개발에 관한 연구)

  • Cho Geon
    • Journal of the Korean Operations Research and Management Science Society
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    • v.31 no.1
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    • pp.91-103
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    • 2006
  • Given a bill of materials (BOM) tree T labeled by the breadth first search (BFS) order from node 0 to node n and a general network ${\Im}=(V,A)$, where V={1,2,...,m} is the set of production facilities and A is the set of arcs representing transportation links between any of two facilities, we assume that each node of T stands for not only a component. but also a production stage which is a possible stocking point and operates under a periodic review base-stock policy, We also assume that the random demand which can be achieved by a suitable service level only occurs at the root node 0 of T and has a normal distribution $N({\mu},{\sigma}^2)$. Then our integrated model of facility location problems and safety stock optimization problem (FLP&SSOP) is to identify both the facility locations at which partitioned subtrees of T are produced and the optimal assignment of safety stocks so that the sum of production cost, inventory holding cost, and transportation cost is minimized while meeting the pre-specified service level for the final product. In this paper, we first formulate (FLP&SSOP) as a nonlinear integer programming model and show that it can be reformulated as a 0-1 linear integer programming model with an exponential number of decision variables. We then show that the linear programming relaxation of the reformulated model has an integrality property which guarantees that it can be optimally solved by a column generation method.

Development of Multi-Attribute Decision Making System for Conceptual Design of Light-Weight Rolling Stock (철도차량 경량화 개념설계를 위한 다속성 의사결정 시스템 설계)

  • Kim, Hee-Wook;Kim, Jong-Woon;Shin, Sung-Ryoung;Jeong, Hyeon-Seung
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.2973-2978
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    • 2011
  • In this paper, a system is developed to support multi-attribute decision making for designing light-weight of rolling stock. Conceptual design of light-weight of rolling stock does not only mean reducing weight. It should be considered about some attributes like safety and environment, technology, etc. So technical attributes and needs of customers, manufacturers and management companies, passengers, should be reflected and qualitative evaluation methods are required. AHP(Analytical Hierarchy Process) and QFD(Quality Function Deployment) are used to decide weighted values of technical attributes and needs from customers. Finally, Alternatives for light-weight of rolling stock that are composed of alternatives of equipment are evaluated by TOPSIS(Technique for Order Preference by Similarity to Ideal Solution). A series of this process are made as a S/W. It could suggest a near-optimal alternative for light-weight of rolling stock.

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Crash Simulation on the Front End Structure of Korean Tilting Train eXpress(TTX) (한국형 고속틸팅열차의 전두부 충돌특성 시뮬레이션)

  • Kim S.R.;Kwon T.S.;Jung H.S.;You W.H.;Koo J.S.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.322-325
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    • 2005
  • TTX(Tilting Train eXpress) is being designed for improving the speed of conventional railway. The purpose of this study is to evaluate energy absorbing capacity and driver's survivability for a design candidate of the front end structure of TTX. A FE model with honeycomb block, under frame, and body frame is generated for crash simulation. Based on a level-crossing accident scenario, numerical simulation is performed using LS-DYNA. The results of crash analysis show that strength improvement of the current front end structure design candidate is needed to ensure driver safety.

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A study on Characteristics of Disc Brake of & Technology of Brake Control System in High Speed Railway (고속차량용 디스크 제동 특성 및 제동제어 방법기술에 대한 연구)

  • Shin Y.J;Choi K.J.;Gwak J.H.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.393-397
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    • 2005
  • Since the braking system of rolling stock is directly linked to it's safety, ensuring reliability of braking system and evaluation of performance of it are very important. To develope the performance of braking system, it is required advanced technology and gradually various factors in the field test result. This study is designed to analyze the air pressure control about braking force in rolling stock, also, by comparing braking force of high speed railway with that of high speed train. This paper suggests to establish a method of computation of braking force form the air pressure control. And The high speed train researches into patterns of braking system such as the train of speed up and introduction of electric and pneumatic braking system.

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A study on the parameters to ensure safety against derailment (탈선 안전성능 향상을 위한 매개변수에 관한 연구)

  • Hwang, Jeong-Taek;Lee, Hi-Sung;Mok, Jin-Yong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.05a
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    • pp.297-303
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    • 2007
  • Derailment is likely to have a direct connection with human life and must be eliminated. A traveling safety evaluation method based mainly on derailment coefficient has already established. But this method is very difficult because Derailment is caused by multiple factors. To evaluate the derailment factor of running train that runs on the curved track, we make use of mechanism that wheel loads and lateral forces were affected by track and rolling stock parameter. In this paper, deal with a search on the parameter and derailment factor. According to results of computer simulation value of Q/P, running safety is connected with operation velocity, curve radius, cant, track irregularity, suspension stiffness and static wheel load ratio, SMRT train Line No. 5 Bogie is selected to do numerical study considering rolling stock and track condition.

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Crashworthiness Analysis of the Urban Maglev Vehicle according to Korean Railway Safety Law and Urban Transit Safety Law (철도안전법과 도시철도안전법을 적용한 도시형 자기부상열차의 충돌안전도 해석)

  • Lee, Hyun-Cheol;Koo, Jeong-Seo
    • Transactions of the Korean Society of Automotive Engineers
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    • v.17 no.5
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    • pp.115-126
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    • 2009
  • This paper studied on the application of the crashworthiness regulations of Korean Railway Safety Law and Urban Transit Safety Law to the urban Maglev vehicle of KIMM. The Urban Maglev vehicle has to comply with the crashworthiness regulations for urban transit vehicles. The collision load cases have been simulated by using explicit finite element analysis. From the numerical results, the crashworthiness regulations of the Urban Transit Safety Law were completely satisfied, but maximum crash pulse requirement in 25 km/h crash event and no plastic deformation requirement in 10 km/h crash event in the Korean Railway Safety Law were not. If a commercial urban Maglev vehicle is developed in the near future, it is necessary that some soft buffing and energy absorbing devices are adopted in its front end so as to satisfy the crashworthiness regulations of the Korean Railway Safety Law.