• 제목/요약/키워드: Safety stock

검색결과 330건 처리시간 0.029초

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

  • 이흥재;장대성
    • 한국철도학회:학술대회논문집
    • /
    • 한국철도학회 2009년도 춘계학술대회 논문집 특별세미나,특별/일반세션
    • /
    • pp.323-337
    • /
    • 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.

  • PDF

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

  • 손영진;이강원;방연근
    • 한국철도학회:학술대회논문집
    • /
    • 한국철도학회 2005년도 춘계학술대회 논문집
    • /
    • pp.58-63
    • /
    • 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.

  • PDF

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

  • 권익현;김성식
    • 대한안전경영과학회지
    • /
    • 제8권3호
    • /
    • pp.115-123
    • /
    • 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.

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

  • 양신추;김인재;김은
    • 한국철도학회:학술대회논문집
    • /
    • 한국철도학회 2006년도 추계학술대회 논문집
    • /
    • pp.1306-1311
    • /
    • 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

  • PDF

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

  • 조건
    • 한국경영과학회지
    • /
    • 제31권1호
    • /
    • pp.91-103
    • /
    • 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.

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

  • 김희욱;김종운;신성룡;정현승
    • 한국철도학회:학술대회논문집
    • /
    • 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
    • /
    • pp.2973-2978
    • /
    • 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.

  • PDF

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

  • 김승록;권태수;정현승;유원희;구정서
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 2005년도 춘계학술대회 논문집
    • /
    • pp.322-325
    • /
    • 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.

  • PDF

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

  • 신유정;최경진;곽재호
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 2005년도 춘계학술대회 논문집
    • /
    • pp.393-397
    • /
    • 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.

  • PDF

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

  • 황정택;이희성;목진용
    • 한국소음진동공학회:학술대회논문집
    • /
    • 한국소음진동공학회 2007년도 춘계학술대회논문집
    • /
    • pp.297-303
    • /
    • 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.

  • PDF

철도차량용 축전지 적용 사례 (Cases of applying battery to rolling stock)

  • 김상웅;김신국;안홍관;김재기
    • 한국철도학회:학술대회논문집
    • /
    • 한국철도학회 2011년도 춘계학술대회 논문집
    • /
    • pp.413-422
    • /
    • 2011
  • 축전지는 차량을 기동할 때나 비상시의 제어전원으로서 철도차량의 구성품 중 매우 중요한 부분이다. 현재 널리 사용되고 있는 축전지로는 연축전지와 니켈카드뮴축전지 등이 있으며 점차 소형화 경량화 되어 가고 있는 추세이다. 또한 철도차량의 전자제어기술의 발달로 인하여 필요로 하는 전기용량이 늘어나고 있다. 따라서 다양한 종류의 고효율 축전지들이 신규 노선의 차량에 검토되고 있지만 철도차량용 축전지는 안전상으로 충분히 검증이 되어야 하며 또한 관리 측면에서도 어려움이 없어야 하는 요구조건으로 인하여 실제 적용하는 데에는 많은 어려움이 있다. 본 논문에서는 현재 철도차량에 적용된 축전지 사례를 조사하고 적용을 시도 중인 축전지들의 특성을 확인하여 안전 및 성능, 관리적인 측면에서 어떠한 문제가 있는지 검토하여 향후 축전지 발전 동향에 대하여 논하고자 한다.

  • PDF