• 전기학회논문지P
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• 제62권3호
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• pp.151-158
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• 2013

Large generator of power plant is very important. In order to protect large generator from faults, digital protective relay or IED is required. However, all protective relays for generators of the domestic power plant are operated by foreign products. And now, for technological independence from foreign and improvement of import substitution effect, IEDs using domestic technology are being developed. To evaluate performance of developing next-generation power devices, the study of the dynamic characteristics of the power plant, generator system modeling, fault simulation and analysis, should be considered. Specially, To obtain IEEE Standards COMTRADE format for relay operation test, generator system modeling and fault simulation using PSCAD/EMTDC tools must be preceded. Until now, a complete modeling of generator internal windings and fault simulation techniques dose not exist. In this paper, for evaluation performance of relay elements of developing IED, the generator system modeling and various faults simulation using PSCAD/EMTDC tools were performed. And then, the various transient phenomena through obtained relaying signal of developed modeling were analyzed.

• 한국정밀공학회지
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• 제12권8호
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• pp.122-130
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• 1995

To reduce the shock in shifting, the clutches and the brakes in automatic transmission have to be connected smoothly and disconnected rapidly. It is PCSV(Pressure Control Solenoid Valve) that paly this role of automatic transmission. In this paper, there were two steps in the analysis of the PCSV. The first step was modeling the elctromagnet by the permeance method. The second step was modeling the hydraulic circuit by the pressure differential equa- tion. In addition to this modeling, a experiment was performed and the commercial package program was used in order to justify modeling. The result of modeling coincide with the result of experiment and commercial package program. As a result, this modeling is usable in analysis of dynamic characteristics of the PCSV.

• Spatial Information Research
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• 제9권2호
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• pp.185-206
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• 2001

셀룰라 오토마타(CA)는 복합체(complex system)의 특성과 행태를 분석하거나 시뮬레이션 하기 위해서 고안된 이론적 체계로 자연과학 및 공학의 여러 분야에서 연구되어왔다. 최근 GIS 분야에서는 CA가 가지고 있는 시공간적 동적 모델 구현의 개념적 우수성과 래스터 GIS와의 유사성에 근거하여 CA와 GIS를 이용한 다양한 모델링 연구가 발표되고 있다. 그러나 대부분의 연구에서 개발된 CA모델들은 GIS의 제한된 기능을 바탕으로 구현되어 CA가 가지고 있는 장점들을 충분히 활용하고 있지 못하며 실제적인 모델링 연구에 활용될 수 있는 통합시스템이 개발되어 있지 않다. 본 연구에서는 CA를 GIS의 모델링 엔진으로 결합하여 동적 공간 모델링 혹은 시뮬레이션을 수행할 수 있는 범용의 CA-GIS 통합시스템을 개발하였다. 이러한 CA-GIS 통합시스템을 개발하였다. 이러한 CA-GIS 통합시스템은 GIS의 동적 공간 모델링 기능을 대폭 보완할 수 있을 것으로 기대되며 도시성장 예측모델 개발과 같은 실제적인 모델링 연구 수행에 효과적인 도구로 활용될 수 있을 것으로 판단된다.

• Journal of Advanced Marine Engineering and Technology
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• 제27권4호
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• pp.520-525
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• 2003

This article provides a dynamic modeling methodology of engines to be accurate with a small number of degrees of freedom for an active vibration control using a top bracing. First. a finite element (FE) model for the engine structure is constructed so that the size of model is as small as possible where the dynamic characteristics of engine are ensured. Second. a technique is studied to obtain the exact mass and stiffness matrices of the FE model. The size of matrices from the FE model is still too large to apply. Finally, a model reduction is. therefore. conducted to make an appropriate dynamic model for designing and simulating a top bracing. In this article, a dynamic model of a large 9 cylinder engine is constructed and reviewed by comparing its natural frequencies and steady state reponses with those of experimental data provided by manufacturer.

• Industrial Engineering and Management Systems
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• 제6권1호
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• pp.72-82
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• 2007

Business Rules are formal statements about the data and processes of an enterprise. They present projections of the organization's constraints and ways of working on their supporting information systems. Therefore, their collection, structuring and organization should be central activities within information systems. In an enterprise, business rules are used to represent certain aspects of a business domain (static rules) or business policy (dynamic rules). Hence, regarding problem domains in the organization, business rules are classified into two groups: static and dynamic business rules. The paper introduces a new concept of business rules, Extended Dynamic Business Rule (EDBR) which contains the results of the occurrence of business rule's action. The focus of this paper is in the organizing, defining and modeling of such business rules using Mineau's approach. Mineau's approach is an extension of Sowa's Conceptual Graph theory.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.119.5-119
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• 2002

$\textbullet$ Lack of exact dynamic modeling of omni-directional mobile robots $\textbullet$ The exact dynamic model of the mobile robots including the wheel dynamics $\textbullet$ The joint-space and operational-space dynamic model of the mobile are dervied as anaytical forms $\textbullet$ Comparison between the discrepancy of the incomplete dynamic and the exact dynamic $\textbullet$ Useful aspect of redundant actuation

• 소음진동
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• 제9권5호
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• pp.966-974
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• 1999

This paper introduces modeling and its modal analysis procedure for exact and closed form solution of in-plane vibrations of general Timoshenko frame structures using exact dynamic element method(EDEM). The derivation procedure of the exact system dynamic matrices for Timoshenko beam frames is described. A new modal analysis procedure is also proposed since the conventional modal analysis schemes are not adequate for the proposed, exact system dynamic matrix. The proposed method provides exact modal parameters as well as all kinds of closed form solutions for general frame structures. Two numerical examples are presented for validating and illustrating the proposed method. The numerical study proves that the proposed method is useful for dynamic analysis of frame structures.

• KIEE International Transactions on Power Engineering
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• 제4A권2호
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• pp.51-57
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• 2004

This paper describes the dynamic performance of a variable speed wind turbine system responding to a wide variety of wind variations. Modeling of the wind generation using power electronics interface is proposed for dynamic simulation analysis. Component models and equations are addressed and their incorporations into a transient analysis program, PSCAD/EMTDC are provided. A wind model of four components is described, which enables observing dynamic behaviors of the wind turbine resulting from wind variations. Controllable power inverter strategies are intended for capturing the maximum power under variable speed operation and maintaining reactive power generation at a pre-determined level for constant power factor control or voltage regulation control. The components and control schemes are modeled by user-defined functions. Simulation case studies provide variable speed wind generator dynamic performance for changes in wind speed

• 한국정밀공학회지
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• 제29권10호
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• pp.1062-1069
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• 2012

This paper suggests a computational modeling to reflect static/dynamic characteristics of LM bearings. A theoretical study for modeling LM bearings is elucidated by using the Hertz contact theory, the Lagrange's equation of motion, normal mode analysis and a calculation of equivalent moment center. The complex geometry of LM bearings is replaced by a simplified model with eight springs only. The suggested model reflects static and dynamic characteristics of LM bearings without any consideration for the shape of the bed or stages on the LM bearings. The modal experimental results are compared to the simulation results with the suggested computational modeling. The difference between the experiments and simulation is calculated less than 8%.

• International Journal of Naval Architecture and Ocean Engineering
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• 제10권3호
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• pp.318-328
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• 2018

Disk type underwater gliders are a new type of underwater gliders and they could glide in various directions by adjusting the internal structures, making a turnaround like conventional gliders unnecessary. This characteristic of disk type underwater gliders makes them have great potential application in virtual mooring. Considering dynamic models of conventional underwater gliders could not adequately satisfy the motion characteristic of disk type underwater gliders, a nonlinear dynamic model for the motion simulation of disk type underwater glider is developed in this paper. In the model, the effect of internal masses movement is taken into consideration and a viscous hydrodynamic calculation method satisfying the motion characteristic of disk type underwater gliders is proposed. Through simulating typical motions of a disk type underwater glider, the feasibility of the dynamic model is validated and the disk type underwater glider shows good maneuverability.