• 제목/요약/키워드: Industrial equipment

검색결과 2,212건 처리시간 0.036초

전투준비태세 및 유사장비 운용자료를 활용한 RAM 목표 값 설정방법에 관한 연구 (Establishing Method of RAM Objective Considering Combat Readiness and Field Data of Similarity Equipment)

  • 김경용;배석주
    • 산업경영시스템학회지
    • /
    • 제32권3호
    • /
    • pp.127-134
    • /
    • 2009
  • RAM(Reliability, Availability, Maintainability) is important performance factor to keep combat readiness and optimize operational and maintenance cost of weapon systems. This paper discusses the method to establish RAM for combat readiness by using field failure data from similarity equipments. Operational availability is estimated from a binomial distribution function of user's operational conditions such as combat readiness preservation probability, operational rate, operational availability and total number of equipment. Reliability and maintainability is estimated from field failure data from similarity equipment to accomplish operational availability. The effectiveness of established RAM is verified through analysis of combat readiness preservation probability and mission reliability. A case study of weapon system illustrates the process of the proposed method.

A simplified directly determination of soil-water retention curve variables

  • Niu, Geng;Shao, Longtan;Guo, Xiaoxia
    • Geomechanics and Engineering
    • /
    • 제23권5호
    • /
    • pp.431-439
    • /
    • 2020
  • Soil-water retention curve (SWRC) contains key information for the application of unsaturated soil mechanics principles to engineering practice. The SWRC variables are commonly used to describe the hydro-mechanics of soils. Generally, these parameters are determined using the graphical method which can be time consuming. The SWRC is highly dependent on the pore size distribution (PSD). Theoretically, the PSD obtained by mercury intrusion porosimetry test can be used to determine some SWRC variables. Moreover, the relationship between SWRC and shrinkage curve has been investigated. A new method to determine total SWRC variables directly without curve-fitting procedure is proposed. Substituting the variables into linear SWRC equations construct SWRC. A good agreement was obtained between predicted and measured SWRCs, indicating the validity of the proposed method for unimodal SWRC.

수송 네트워크에서 빈 장비 흐름의 계산법 (Calculating Empty Moves in Transportation Networks)

  • 김갑환
    • 대한산업공학회지
    • /
    • 제31권3호
    • /
    • pp.201-209
    • /
    • 2005
  • Empty moves are necessary when there are imbalances among transportation demands from source locations to destination locations and the transportation demands require empty equipment that must be supplied to source locations. When the amount of the inflow exceeds that of the outflow or the amount of the outflow exceeds that of the inflow, repositioning empty equipment is necessary. Examples of the empty equipment are containers, chassis, and pallets. This paper addresses how to estimate the empty moves on several typical transportation networks. Types of transportation networks considered are chain, tree, cycle, tree of cycles, and hybrid networks. Simple procedures are suggested for determining the optimal empty flows. Numerical examples are provided to illustrate procedures in this paper.

아크회전과 열팽창 방식을 적용한 소호부에 대한 아크유동 해석 (The development of computational fluid dynamics tools for thermal expansion type interrupter with the arc rotary)

  • ;이방욱;서정민
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2000년도 하계학술대회 논문집 B
    • /
    • pp.813-815
    • /
    • 2000
  • This paper is concerned with the development of PC based computer simulation and design tools for auto-expansion SF6 circuit breaker with the arc rotary. The simulation model takes into account radiation transport, turbulence enhanced momentum. energy transport. The conversation gas dynamic equation together with Maxwells equations are solved. For the arc simulation the straightforward procedure has been used. The temperature, gas density and velocity space distributions within the circuit breaker are simulated in details. The presented results show that the computer simulation of gas flow in SF6 interrupter is a subject of much interest for design and optimization of contacts. The presented results show that the shape and sizes of contacts are chosen by this tool from judiciously compromise between electrical breakdown strength and interruption ability that are functions of gas flow parameters.

  • PDF

IEC60947-2에 따른 누전차단기의 순시단락시험 과도현상에 대한 연구 (The Transient Analysis of Instant Short-Circuit Test Equipment For Earth Leakage Circuit Breaker)

  • 류행수;김명석;한규환
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2003년도 하계학술대회 논문집 A
    • /
    • pp.357-359
    • /
    • 2003
  • This paper is for the transient analysis of instant short-circuit test equipment according to the test of tripping limits and characteristics under IEC 60947-2. The in-rush current is harmful to almost equipments and the exact testing is not made because of it. LGIS has a instant short-circuit test equipment, but it is not suitable for carrying out instant short-circuit test on ELB(Earth Leakage Circuit breaker) by reason of that. Now, I am going to show a solution for that problem. After applying this method, manufacturer is going to acquire the exact testing result according to the IEC standard. Moreover, Testing laboratory will be trusted by clients.

  • PDF

Fatigue performance assessment of welded joints using the infrared thermography

  • Fan, J.L.;Guo, X.L.;Wu, C.W.
    • Structural Engineering and Mechanics
    • /
    • 제44권4호
    • /
    • pp.417-429
    • /
    • 2012
  • Taking the superficial temperature increment as the major fatigue damage indicator, the infrared thermography was used to predict fatigue parameters (fatigue strength and S-N curve) of welded joints subjected to fatigue loading with a high mean stress, showing good predictions. The fatigue damage status, related to safety evaluation, was tightly correlated with the temperature field evolution of the hot-spot zone on the specimen surface. An energetic damage model, based on the energy accumulation, was developed to evaluate the residual fatigue life of the welded specimens undergoing cyclic loading, and a good agreement was presented. It is concluded that the infrared thermography can not only well predict the fatigue behavior of welded joints, but also can play an important role in health detection of structures subjected to mechanical loading.

2계층 분배시스템에서 혼합재고정책을 이용한 적정재고수준 결정에 관한 연구 (Determining the Proper Level of Spare Parts using the CSP and (r,Q) Policies in a Two-Echelon Distribution System)

  • 정석재;이정학;김경섭
    • 대한안전경영과학회지
    • /
    • 제9권4호
    • /
    • pp.121-127
    • /
    • 2007
  • CSP(Concurrent Spare Parts) is supplied with the procurement of new equipment or weapon system and is used to sustain the equipment without resupply during the initial coverage period. This study is concerned with a problem of determining the near optimal inventory level of the spare parts, especially Concurrent Spare Parts. For this, we utilize the mixed periodic and continuous review polices considering the CSP and (r,Q) Policies concurrently in a two-echelon distribution system. We propose the mathematical model to minimize the total cost which is composed with ordering cost, purchasing cost, holding cost, and stickout cost. If the mixed policy is compared to other policies(CSP, (r,Q)), the proposed methodology performs well and is best policy in the equipment maintenance expenses.

컨테이너 터미날에서의 유전자 해법을 이용한 적하계획법 (Load Scheduling Using a Genetic Algorithm in Port Container Terminals)

  • 김갑환;김기영;고창성
    • 대한산업공학회지
    • /
    • 제23권4호
    • /
    • pp.645-660
    • /
    • 1997
  • An application of the genetic algorithm(GA) to the loading sequencing problem in port container terminals is presented in this paper. The efficiency of loading operations in port container terminals is highly dependent on the loading sequence of export containers. In order to sequence the loading operation, we hove to determine the route of each container handling equipment (transfer crane or straddle carried in the yard during the loading operation. The route of a container handling equipment is determined in a way of minimizing the total container handling time. An encoding method is developed which keeps intermediate solutions feasible and speeds up the evolution process. We determine the sequence of each individual container which the container handling equipment picks up at each yard-bay as well as the visiting sequence of yard-bays of the equipment during the loading operation. A numerical experiment is carried out to evaluate the performance of the algorithm developed.

  • PDF

장비 가용도를 고려한 최적 수리부품 재고수준 결정 (Determining the Optimal Spare Parts Level Considering Equipment Availability)

  • 우제웅;강맹규
    • 산업경영시스템학회지
    • /
    • 제21권47호
    • /
    • pp.87-99
    • /
    • 1998
  • This study is concerned with a problem of determining the optimal requirements level of the spare parts, especially Concurrent Spare Parts(CSP). CSP is supplied with the procurement of new equipment system, and is used to sustain the equipment without resupply during the initial coverage period. We consider this situation as a multiechelon inventory model with several bases and one depot. And we assume a equipment system which consists of many types of parts would grounded if one of the parts fail. Also this multiechelon CSP problem is considering a time-varing (dynamic) environment. We develop a computational procedure to find the optimal number of spare parts minimizing the total expected cost, while achieving the required system availability. Finally we present a simple example of suggested method.

  • PDF

건설기계 유압밸브 생산을 위한 일정계획 시스템 개발 (Development of Scheduling System for Production of the Hydraulic Control Valve of Construction Equipment)

  • 김기동;이보헌
    • 산업기술연구
    • /
    • 제27권A호
    • /
    • pp.61-67
    • /
    • 2007
  • The construction machine is the composite machine assembled by about 30,000 parts. Excavator, one kind of a construction machine, plays the leading role for export of construction equipment. It is generally impossible to produce all of the items within one company. Especially the supply of hydraulic control valves, one of the core part of the construction equipment, depends on the import heavily. So it is important to make an efficient production plan of hydraulic control valves in the company. The most important thing for the production scheduling of a hydraulic control valve is to make production schedule keeping the start date for assembly line for an excavator and to make minimization of the stock level. The production plan of hydraulic control valve includes the decision of the quantity supplied by subcontractor. This paper presents a scheme for a scheduling system of the hydraulic control valve considering the schedule of the assembly line for excavator production. This paper provides a methodology, which can make a plan of supply and production and generate a detailed schedule for daily production.

  • PDF