• Title/Summary/Keyword: science simulation

Search Result 11,068, Processing Time 0.04 seconds

Effect Analysis of Factors for Improving Accuracy of RAM Simulation in Weapon System (무기체계 RAM 시뮬레이션의 정확도 향상을 위한 요소별 영향 분석)

  • Chung, Il-Han;Park, Sam-Joon
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.11 no.6
    • /
    • pp.102-116
    • /
    • 2008
  • In the development stage of weapon system, it is important to analyze RAM(Reliability, Availability and Maintainability) characteristics. RAM simulation is one of the advanced techniques for analyzing RAM to overpass the limit of mathematical techniques. However, it is necessary to obtain correct input data for reliability and maintainability about target and support system to get highly accurate results through RAM simulation. In this study, we propose the technical method to improve the results by defining input data of simulation more correctly based on analyzing effects of RAM characteristics by major factors.

A Study on the Development of Simulation Model for Inchon Port (인천내항을 위한 시뮬레이션 모델 개발)

  • 김동희;김봉선;이창호
    • Proceedings of the Safety Management and Science Conference
    • /
    • 2000.05a
    • /
    • pp.339-349
    • /
    • 2000
  • Inchon Port is the second largest import-export port of Korea, and has the point at issue such as the excessive logistics cost because of the limits of handling capacity and the chronic demurrage. There are few research activities on the analysis and improvement of the whole port operation, because Inchon Port not only has the dual dock system and various facilities but also handles a various kind of cargo. The purpose of this paper is to develop the simulation program as a long-term strategic support tool, considering the dual dock system and the TU(Terminal Operation Company) system executed since March, 1997 in Inchon Port. The basic input parameters such as arrival intervals, cargo tons, service rates are analyzed and the probability density functions for these parameters are estimated. The main mechanism of simulation model is the discrete event-driven simulation and the next-event time advancing. The program is executed based on the knowledge base and database. From the simulation model, it is possible to estimate the demurrage status through analyzing various scenarios and to establish the long-term port strategic plan.

  • PDF

A Study on Internal Moisture Gradients of Wood (목재(木材) 건조중(乾燥中) 내부수분경사(內部水分傾斜)에 관(關)한 연구(硏究))

  • Kang, Ho-Yang
    • Journal of the Korean Wood Science and Technology
    • /
    • v.19 no.2
    • /
    • pp.30-39
    • /
    • 1991
  • Internal moisture gradients of 3cm-thick radiata pine (Pinus radiata) sapwood and meranti(Shorea spp.) heartwood were determined by using slicing method during drying and were predicted by Hart's Sorption Simulation. The shapes of internal moisture gradients. moisture contents and drying rates, which were obtained by the slicing method. were compared with those predicted by Sorption Simulation. After the 2nd fitting attempts. the differences between the gravimetric drying rates and the drying rates predicted by Sorption Simulation were less than 0.021%/hr for radiata pine and 0.043%/hr for meranti. The shapes of the internal moisture gradients predicted by Sorption Simulation were in good agreement with those obtained by the slicing method. It could be concluded that Sorption Simulation be an excellent tool to predict internal moisture gradients of wood.

  • PDF

A Study on the HWIL Simulation System of the Flight Object including Inertial Navigation System (관성항법장치가 포함된 비행체의 HWIL 시뮬레이션 시스템 개발 연구)

  • Lee, Ayeong
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.21 no.3
    • /
    • pp.349-360
    • /
    • 2018
  • This paper proposes various methods for constructing a HWIL simulation system including Inertial Navigation System(INS) and Guidance Control Unit(GCU) under the assumption that the INS identifies the initial attitude of an aviation body through its own alignment and that it is a package consisting of an inertial sensor and a navigation computation module. This paper also presents a real-time computing technology and a way to calculate the command of the Flight Motion System(FMS) analogous to the acutal flight environment. The proposed HWIL simulation system is constructed by applying the above-mentioned methods and the results of running a series of simulations confirm high effectiveness and usefulness of the system. Finally, minor error factors that could be acquired only in HWIL simulation Environment are analyzed.

Electric Ballast Analysis by Piezoelectric Transformer and CCFL Modeling (압전변압기와 CCFL 모델링에 의한 전자식 안정기 해석)

  • Hwang L. H.;Jang E. S.;Shin Y. H.;Cho S. R.;Cho M. T.;Ahn I. S.
    • Proceedings of the KIPE Conference
    • /
    • 2002.07a
    • /
    • pp.237-240
    • /
    • 2002
  • A CCFL model for high frequency dimming electronic ballast simulation is presented in this paper. The model can be utilized for an electronic ballast simulation with continuous dimming and transient mode simulation such as step dimming. The piezoelectric transformer Is evaluated using an AC analysis. The electronic ballast composed of piezoelectric transformers and ZVS inverter was implemented. It enables a fluorescent lamp to be fumed on stably. Simulation of a high frequency electronic ballast which operates a fluorescent Imp at high frequency is proposed. Simulation is carried out using PSPICE program to illustrate the performance of the circuit

  • PDF

A Simulation Study Based on the Continuous Berth Utilization in Inchon Port (선석의 연속접안을 고려한 인천항의 시뮬레이션 연구)

  • 최현규;이창호
    • Proceedings of the Safety Management and Science Conference
    • /
    • 2000.11a
    • /
    • pp.95-99
    • /
    • 2000
  • The domestic ports become less competitive for the out of dated equipments and inefficient information system. Specially, Inchon Port, which is the second largest port of Korea, has the point at issue such as the excessive logistics cost because of the limit of handling capacity and the chronic demurrage. In this paper to develope the simulation programs the basic input parameters such as arrival intervals, cargo tons, service rates are analyzed and the probability density functions for there variable are estimated. Also to perform the conception of continuous berth utilization, the berth and cargo classification is reconstructed. And the more actual simulation is realized by using more detailed depth representation of water The simulation model is executed based on the knowledge base and database, and is constructed using Visual Basic and Access database. Simulation results reveal that this study suitably reflect the real berth operation and waiting time of ships is shortened.

  • PDF

A Design Procedure for Safety Simulation System Using Virtual Reality

  • Ki, Jae-Seug
    • Journal of the Korea Safety Management & Science
    • /
    • v.1 no.1
    • /
    • pp.69-77
    • /
    • 1999
  • One of the objectives of any task design is to provide a safe and helpful workplace for the employees. The safety and health module may include means for confronting the design with safety and health regulations and standards as well as tools for obstacles and collisions detection (such as error models and simulators), Virtual Reality is a leading edge technology which has only very recently become available on platforms and at prices accessible to the majority of simulation engineers. The design of an automated manufacturing system is a complicated, multidisciplinary task that requires involvement of several specialists. In this paper, a design procedure that facilitates the safety and ergonomic considerations of an automated manufacturing system are described. The procedure consists of the following major steps. Data collection and analysis of the data, creation of a three-dimensional simulation model of the work environment, simulation for safety analysis and risk assessment, development of safety solutions, selection of the preferred solutions, implementation of the selected solutions, reporting, and training. When improving the safety of an existing system the three-dimensional simulation model helps the designer to perceive the work from operators point of view objectively and safely without the exposure to hazards of the actual system.

  • PDF

A Study for dispersion evacuation by behavioral characteristics based on human cognitive abilities (인간의 인지능력 기반의 행동특성이 반영된 분산대피에 관한 연구)

  • Jang, Jae-Soon;Rie, Dong-Ho
    • Journal of the Korea Safety Management & Science
    • /
    • v.14 no.3
    • /
    • pp.159-166
    • /
    • 2012
  • A*algorithm is highly useful to search the shortest route to the destination in the evacuation simulation. For this reason, A*algorithm is used to evaluate the evacuation experiment by the computer simulation. However there are some problems to analyze the outcome in relation to the reality. Because all the people in the building are not well-informed of the shortest route to the exit. And they will not move to the disaster spot though it is shortest route to the exit. Therefore, evacuation simulation program based on A*algorithm raise a problem of bottleneck phenomenon and dangerous result by damage surrounding the disaster spot. The purpose of this research is to prove the necessity for dispersion evacuation simulation by Multi agent system to solve the problems of the existing evacuation simulation program based on A*algorithm.

A Study of the Effects of Agent Activeness on Team Performance (행위자의 능동성이 팀 성과에 미치는 영향에 관한 연구)

  • 강민철
    • Journal of the Korean Operations Research and Management Science Society
    • /
    • v.25 no.1
    • /
    • pp.93-104
    • /
    • 2000
  • Passive agents participate in team activities passively, that is, only upon requst, whereas active agents involve themselves voluntarily. Teams composed of active agents are generally believed to perform better than those with passive agents. In this paper, by using a computational simulation model we examine the effect of agent activeness on the efficiency of decision-making teams that access different amout of information. "Team-Soar" is a computational fraemwork that consists of a group of interconnected individual Al agents (i.e., Soar). A simulation experiment using Tearm-Soar was performed. Results of the simulation provide valuable insights on the roles of agent activeness. For example, the impact of having more active agents becomes more sigfniciant as the amout of information to process increases and when the team decision efficiency is important. Some of the results are counter-intultive and therefore provides an opportunity to understand the roles of the agnet activeness more deeply. For instance, the simulation results reveal that having more active agents did not always enhance team efficiency. Conclusively, the simulation experiment demonstrates how computational models contribute to the research of agents social characteristics.teristics.

  • PDF

Analysis of the effects of information-sharing on supply chain management using simulation (시뮬레이션을 이용한 공급사슬관리에서의 정보공유 방식에 따른 효과분석)

  • Li, Guang-Zhu;Lee, Chang-Ho
    • Journal of the Korea Safety Management & Science
    • /
    • v.12 no.4
    • /
    • pp.153-160
    • /
    • 2010
  • In this paper, effects of information sharing in multi-level supply chain management have been studied through simulation. The simulation model consists of a manufacturing company as a center, three suppliers, two logistic centers, and three different retail supply lines of each logistics centers. The mathematical model and the simulation were developed when real-time information sharing occurs and does not occur in supply chain under the assumption that each company applies (s, S) inventory policies. In addition, this paper analyzed the effects of the change of variables related to total costs, which compose of total ordering cost, total transportation cost, total carrying cost and shortage cost that are caused by the change of demand of three different patterns with the way of information sharing.