• KIEAE Journal
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• 제15권4호
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• pp.5-11
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• 2015

Purpose: Recently, renewable energy system has been widely used to reduce the energy consumption and CO2 emission of building. A photovoltaic/thermal(PVT) system is a kind of efficient energy uses, which is combined with photovoltaic module and solar thermal collector. PVT system removes heat from PV module by through thermal fluid to raise the performance efficiency of the PV system. However, though PVT system has the merit of the improved efficiency in theoretical approach, there have been few performance analysis for PVT system using the dynamic energy simulation. In this study, in order to establish the optimum design method of this system, simulation was conducted by using individual system modules. Method: For the dynamic simulation, TRNSYS17 was used and local weather data was utilized. Furthermore, the system performance in various installation condition was calculated by case studies. Result: As a result, the amount of electric generation and heat production in each case was found by the simulation. The gap of system performance was also evident according to the installation condition.

• 한국시뮬레이션학회논문지
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• 제21권4호
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• pp.81-90
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• 2012

본 논문은 지상무기체계 교전을 모의하기 위한 시뮬레이션 시스템 구축에 관한 연구이다. 본 논문에서는 에이전트 시뮬레이션 설계 방법론에 기반하여 시뮬레이션 시스템 아키텍처를 제안한다. 제안된 아키텍처의 각 개체는 에이전트 기반으로 모듈화된 컴포넌트들을 조합하여 구성된다. 이와 같은 개체 구성 방법은 개체의 재사용성과 조합성을 향상시키고, 결과적으로 시뮬레이션 시스템의 개발에 투입되는 시간, 비용, 및 노력을 감소시킨다. 지상무기체계 교전의 모의는 환경의 영향을 반영하는 것이 매우 중요하다. 제안된 아키텍처의 합성전장환경은 전장의 환경 데이터를 가지며 시뮬레이션 시스템의 전투개체와 계속적으로 상호작용한다. 이러한 아키텍처를 기반으로 구축된 시뮬레이션 시스템은 목적에 따라 다양한 지상무기체계 교전 시나리오의 신속한 모의가 가능하고, 개체들의 행위 수행에 환경 영향이 반영되어 신뢰성 있는 시뮬레이션 결과를 도출할 수 있다. 본 논문은 제안된 아키텍처를 기반으로 예제 시스템을 구축하여 그 효용성을 증명하였다.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.1359-1363
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• 2009

The object of this research is to develop a simulation system for earthmoving operations in consideration of the impact of congestion in-between equipment and existing traffic flow around the site. The congestion in-between equipment and traffic flow affect work productivity. The conventional discrete event simulation, however, has limitations in simulating the flow of construction equipment. To consider the impact of congestion in-between equipment and existing traffic flow, in this paper, a multi-agent based simulation model that can realize characteristics of truck behavior more accurately to consider the impact of congestion was proposed. In this simulation model, multiple agents can identify environmental changes and adapt themselves to the new environment. This modeling approach is a better choice for this problem since it describes behavioral characteristics of each agent by sensing changes in dynamic surroundings. This study suggests a detailed system design of the multi-agent based simulation system.

• 한국시뮬레이션학회논문지
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• 제12권4호
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• pp.103-111
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• 2003

A distributed sewer cluster system is a cost-effective system to provide a service application for clients with reliable, scalable, available, and fault-tolerant features. In order to provide high quality services, it is necessary to evaluate service performances, tune the server system, and analyze performances. In this paper, we propose a simulator to generate workloads based on statistic configuration according to estimated application traffics, apply workload scheduling algorithms, and evaluate the simulation results. We introduce the simulator design modelling and architecture. By using flexible parameters, the simulator is able to generate various patterns of workloads with different statistics, and configure system environments such as the number of server nodes, system resources considered, and their capacities. With this simulator, we introduce two scenarios: one is to find appropriate thresholds for the best performance of cluster system, and the other is to find the suitable scheduling algorithm for workload characteristics of service applications.

• 한국시뮬레이션학회논문지
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• 제10권3호
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• pp.1-14
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• 2001

A hybrid system is defined as a mixture of continuous systems and discrete event systems. This paper first proposes a framework for hybrid systems modeling, called Hybrid Discrete Event System Specification (HDEVS) formalism. It then presents a method for simulators interoperation in which a continuous system simulator and a discrete event simulator are executed together in a cooperative manner. The formalism can specify a hybrid system in a way that a continuos system and a discrete event system are separately modeled by their own specification formalisms with a support of well-defined interface. We call such interface an A/E converter for analog-to- event conversion and an E/A converter for event-to-analog conversion. Simulators interoperation is based on the concept of pre-simulation in which simulation time for a continuous simulator is advanced in accordance with a discrete event simulator.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2003년도 추계학술대회 및 정기총회
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• pp.27-34
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• 2003

A distributed server cluster system is a cost-effective system to provide a service application for clients with reliable, scalable, available, and fault-tolerant features. In order to provide high quality services, it is necessary to evaluate service performances, tune the server system, and analyze performances. In this paper, we propose a simulator to generate workloads based on statistic configuration according to estimated application traffics, apply workload scheduling algorithms, and evaluate the simulation results. We introduce the simulator design modelling and architecture. By using flexible parameters, the simulator is able to generate various patterns of workloads with different statistics, and configure system environments such as the number of server nodes, system resources considered, and their capacities. With this simulator, we introduce two scenarios: one is to find appropriate thresholds for the best performance of cluster system, and the other is to find the suitable scheduling algorithm for workload characteristics of service applications.

• 한국군사과학기술학회지
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• 제9권3호
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• pp.25-32
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• 2006

Weapon systems composed of several subsystems execute various engagement missions in distributed combat environments in cooperation with a large number of subordinate/adjacent weapon systems as well as higher echelons through tactical data links. Such distributed weapon systems require distributed real-time simulation test beds to integrate and test their operational software, analyze their performance and effects of cooperated engagement, and validate their requirement specifications. These demands present significant challenges in terms of real-time constraints, time synchronization, complexity and development cost of an engagement simulation test bed, thus necessitate the use of high-performance distributed real-time simulation architectures, and modeling and simulation techniques. In this paper, in order to meet these demands, we presented a distributed real-time simulation system based on High Level Architecture(HLA) and Discrete Event System Specification(DEVS). We validated its performance by using it as a test bed for developing the Engagement Control System(ECS) of a surface-to-air missile system. The proposed technique can be employed to design a prototype or model of engagement-level distributed real-time simulation systems.

• 한국자동차공학회논문집
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• 제9권6호
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• pp.143-151
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• 2001

During the past several years, the major interests of car manufacturers in development of automatic transmission were in durability and shift quality. However, a large number of researches for improving shift quality that are based on dynamic characteristics of shifting mechanism have been rarely adopted in the developing process because it is quite difficult to predict the shifting performance from the dynamics simulation. One of the important reasons for the difference between simulation results and experiments arises from the automatic transmission hydraulic system that consists of many valves with high order model and shows a lot different dynamics to temperature variation. In this work, hardware-in-the-loop simulation system for automatic transmission was developed f3r improving the accuracy of simulated result by combining the real-time simulation model with the real hydraulic system. The real-time simulation for automatic transmission model excluding hydraulic system is executed with TI's TMS320C31 DSP and the interfacing board which includes 12bit A/D, PWM signal generator and driver, serial driver ,etc is designed for acquiring the simulation data and signal interface with hydraulic system. We verified the proper operation and correctness of shifting result by comparing the off-line simulation result with that of HILS and experimental result which was performed on transmission dynamometer driven by electric motor.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.1036-1041
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• 2008

Double facade systems are often paid attention of as an effective energy saving measure for curtain wall buildings. However, it is not easy to install the system in existing buildings and requires substantial investment. An innovative double window system is proposed in this study which can be installed with exiting window systems in a cost effective way. the proposed system is connected to existing return ducts to make airflow between the existing window and the newly installed window. To ensure the best performance of the proposed system, simulation-based analysis was implemented in which airflow characteristics of inside double window were examined according to air pressures of return duct and window material by using computer simulation ESP-r. the overview of the proposed system and the results of the simulation-based analysis are presented in this paper.

• 산업공학
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• 제20권4호
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• pp.438-447
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• 2007

This paper presents an aspect-oriented approach to simulation design and analysis in system design phase for integrated logistics system simulation. The integrated logistics system composed of AS/RS (Automated Storages and Retrieval System), AGVs (Automated Guided Vehicle System), STVs (Sorting Transfer Vehicle System) and Conveyor System is designed by using the aspect-oriented approach and UML (Unified Modeling Language). The multi-factorial design of experiments and regression analysis are used for design parameters of the system and Evolution Strategies is used to verify each parameter. Aspect-oriented approach for the integrated logistics system simulation shows the advantages of code reusability, extendible, modulation, easy improvement and a better design technique.