• Journal of Astronomy and Space Sciences
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• v.27 no.4
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• pp.377-382
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• 2010

In lunar explorer development program, computer simulator is necessary to provide virtual environments that vehicle confronts in lunar transfer, orbit, and landing missions, and to analyze dynamic behavior of the spacecraft under these environments. Objective of simulation differs depending on its application in spacecraft development cycle. Scope of use cases considered in this paper includes simulation of software based, processor and/or hardware in the loop, and support of ground-based flight test of developed vehicle. These use cases represent early phase in development cycle but reusability of modeling results in the next design phase is considered in defining requirements. A simulator architecture in which simulator platform is located in the middle and modules for modeling, analyzing, and three dimensional visualizing are connected to that platform is suggested. Baseline concepts and requirements for simulator development are described. Result of trade study for selecting simulation platform and approaches of defining other simulator components are summarized. Finally, characters of lunar elevation map data which is necessary for lunar terrain generation is described.

• Journal of Navigation and Port Research
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• v.35 no.6
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• pp.489-494
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• 2011

Present study introduces an implementation of product data management (PDM) that can be applied to the design of ship propulsion system. The PDM system is developed based on both object oriented software development environment and Open Scene Graph (OSG) library while the system architecture is modeled by the unified modeling language (UML). Suggested PDM system also integrates the modeling & simulation components required to estimate the performance of ship propulsion system as the product information is represented based on the 3-dimensional digital mock-up (DMU). Finally, functions of the implemented PDM system that is integrated with the M&S softwares are illustrated in order to suggest a practical guidance for the efficient design of ship propulsion system.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.34 no.6
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• pp.416-425
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• 2021

In the 4^th industrial age, electronic devices are becoming smaller and lighter with a low power consumption to overcome spatial limitation. The piezoelectric energy harvesters can convert mechanical kinetic energy into electric energy; thus, enabling the operation of small electronic devices. Recently, various piezoelectric harvesters have been reported and the electric output from these harvesters could be anticipated by theoretical analysis methods. For example, COMSOL Multiphysics software provides a theoretical simulation of piezoelectric effect with a combination of mechanical and electrical phenomena in the piezoelectric materials. This article introduces a brief modeling of piezoelectric harvester to investigate mechanical stress and electrical output of harvesting devices by the COMSOL Multiphysics software.

• Transactions of The Korea Fluid Power Systems Society
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• v.4 no.4
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• pp.21-27
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• 2007

A hydraulic breaker for construction machinery generally used for the destroying and disassembling of buildings, crashing road pavement, breaking rocks at quarry and so on. So the measurement of the impact energy of a hydraulic breaker is very important thing to prove its capability to manufacturers and customers. Therefore the prediction of impact energy in design process is very helpful to the most of breaker manufacturers. In this study, we carried on modeling and simulation of a hydraulic breaker to predict impact energy via commercial CAE software. The modeling and simulation of a hydraulic breaker was achieved with two parts. One is a hydraulic circuit analysis part via AMESim and the other is impact strain analysis part via ANSYS.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1998.10a
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• pp.99-105
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• 1998

Simulation modeling has become an extremely important approach to analyzing complex system. In recent years the number of people using simulation as problem-solving aid has increased. In this Paper, we developed a simulation model for analyzing the physical distribution system in ports. we used Arena 2.2 which is a kind of simulation software based common simulation language, SIMAN V. And then, we applied this model to kwangyang port(partially) and analyzed the effect of it upon port system in according to change of the quantity of goods transported.

• Journal of the Korea Society for Simulation
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• v.7 no.1
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• pp.15-26
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• 1998

In building a shell-based FMS, which is known as one of the top-down approaches in the field of factory automation, we may take a hybrid simulation into consideration. The modeling of a hybrid simulation consists of real physical entities, virtual simulation, and central clock algorithm, etc. to carry out the whole system operation. In this paper, we sow a way to construct a hybrid simulation software system in manufacturing environments. We bring in the object-oriented methodology in system design and it can contribute in dealing with a wide variety of production types and configurations. Some classes such as project, product, process, order, schedule, stage are defined. These are used and tested by implementing a specific LSI circuit assembly line process.

• Journal of the Korea Society for Simulation
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• v.13 no.1
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• pp.51-63
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• 2004

Current distributed systems are attacked from the outside as well as in which new intrusions are occurred. In particular there is a growing but largely unnoticed intrusion threat due to the emerging middleware technologies such as CORBA, WAP, XML support, and enterprise application integrators. In order to cope with these attacks, intrusion tolerance technology is introduced. Intrusion tolerance technology means that it can provide services normally although attacks are occurred into system. There are intrusion tolerance architectures such as ITUA, HACQIT, SITAR, and so on as a part of DARPA project. In this paper, we analyze and discuss existing intrusion tolerance architectures with respect to intrusion tolerance technology. Also, we extract intrusion tolerant requirements, which are required to develop ,intrusion tolerant system. We propose UML-IT(Intrusion Tolerance) profiles and specify intrusion tolerant software by applying UML-IT profiles.

• Journal of Digital Convergence
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• v.10 no.4
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• pp.287-295
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• 2012

This study aims to develop the methods for effective patient flow in the medical center through simulation modeling. To achieve this, we developed three simulation scenarios based on max/min processing time and addition of X-ray by 15 patient tracks from real hospital data. The simulation software used in this study is Flexsim HC 2.7. According to the scenario 1 on 15 patient tracks' LOS by max processing time, there is a great difference between average length of stay(LOS) and max LOS. And average LOS increases greatly depending on the number of patients by the hours. There is no need to add extra X-ray because the addition of X-ray has not much influence in average LOS. It is possible to make good decisions on patient flow management and medical equipment purchasing through simulation modeling. The concrete simulation scenario as a tool for decision support will contribute to efficiency in hospital management.

• Journal of the Korean Solar Energy Society
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• v.23 no.1
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• pp.48-56
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• 2003

Three of the leading computer daylighting simulation programs are compared with physical modeling techniques as a means of predicting daylighting performance of interior spaces. Lumen-Micro, Adeline and Lightscape are compared with physical model experiments under clear sky conditions. The comparative evaluations are conducted on analysis of daylight illuminance ratio(%) depending on model types. The estimated average errors are analyzed on 9.4% in Lumen-Micro, 6.3% in Adeline and 3.4% in Lightscape. Therefore, it is proved that three programs are useful for evaluating daylighting performance in our clear sky condition.

• Journal of the Korean Society of Safety
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• v.22 no.1 s.79
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• pp.30-35
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• 2007

With the rapid industrialization and civilization development, noise has become a major problem in cities and is a very serious issue for the environment. Noise induced in a factory has a bad influenced on operation efficiency, accuracy and detail of work. The purpose of this paper is to develop a new noise evaluation software for predicting acoustic condition including noise properties during the design of a factory. Majority of commercial softwares for this purpose have been developed in foreign countries and they are quite expensive and hard to use. A new home-made software tool has been developed in the present work, which aimed at providing a more user-friendly environment. The tool developed in this work consists of four major part; the prediction and evaluation of noise in system design, database design, noise analysis development and 3D graphic modeling. The outcome of present work is expected to provide domestic users with a more user-friendly and economic acoustic design tool.