• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.140-145
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• 2005

The dynamic performances of railway vehicles, such as ride comfort, stability and safety, have the opposite characteristics of response each other according to design changes of suspensions. For this reasons, it is necessary that multidisciplinary engineers join in design processes of the suspensions so as to satisfy the requirements of dynamic performance with design constraints. Sometimes iterative dynamic analyses are required so many times during the design processes. In this paper, the development of integrated process environments and the dynamic analyses of railway vehicles based on the environments are presented. Using agent and wrapping technologies, process managements about the work process and design parameters were set up under the distributed computing environments. Also, dynamic analyses on the sample railway vehicle were carried out and the efficiency and improvement in future work were discussed as results.

• 정보화연구
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• 제10권3호
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• pp.295-303
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• 2013

This paper presents a new approach to managing dynamic business process changes based on business process change patterns. We identify and categorize business process change patterns that occur recurrently in a dynamic business environment. Several issues regarding management of process versions are discussed, and a pattern-based version management method for handling process changes more flexibly is explained in detail. We propose a mechanism for abstract process execution with runtime encapsulation of a business process, which can maximize the flexibility of process execution using multiple process versions. In addition, we propose a concept of process promotion and demotion that can dynamically choose an actual version of the process at run-time. With our pattern-based process change management and versioning approach, it is expected that the flexibility and efficiency of BPM systems can be enhanced significantly.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.315-320
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• 1992

This paper presents the simulation architecture and strategy for dynamic simulation of chemical process and describes key features of developed dynamic simulation system, MOSA(Multi-Objective Simulation Architecture). A plant structure may be partioned into several strong coupling units, called cluster. If this cluster is solved simultaneously, it is possible to simulate whole plant without introducing convergence problem of tear streams. In this study, a flexible modular approach based on clusters was proposed as a promising architecture for dynamic chemical process simulator.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.1028-1031
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• 1996

Dynamic scheduling is very important in constructing CIM and improving productivity of chemical processing systems. Computation at the scheduling level requires mostly a long time to generate an optimal schedule, so it is difficult to immediately respond to actual process events in real-time. To solve these problems, we developed dynamic scheduling algorithms such as DSMM(Dynamic Shift Modification Method), PUOM(Parallel Unit Operation Method) and UVVM(Unit Validity Verification Method). Their main functions are to minimize the effects of unexpected disturbances such as process time variations and unit failure, to predict a makespan of the updated dynamic schedule and to modify schedule desirably in real-time responding to process time variations. As a result, the algorithms generate a new pertinent schedule in real-time which is close to the original schedule but provides an efficient way of responding to the variation of process environment. Examples in a shampoo production batch process illustrate the efficiency of the algorithms.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.432-435
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• 1996

The performance of one-column isothermal PSA process is assessed by dynamic simulator, gPROMS. The four-step and five-step processes are compared. A five-step process is employed in order to show the effect of the addtional cocurrent depressurization step on the four-step PSA process. Two processes parameters, purity and recovery of SO$_{2}$ are used for the performance comparison. The results of dynamic simulation show that four-step process is superior to five-step process in recovery, but not in purity.

• Nuclear Engineering and Technology
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• 제41권6호
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• pp.831-840
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• 2009

In order to evaluate the start-up behavior and to identify, through abnormal operation occurrences, the transient behaviors of the Sulfur Iodine(SI) process, which is a nuclear hydrogen process that is coupled to a Very High Temperature Gas Cooled Reactor (VHTR) through an Intermediate Heat Exchanger (IHX), a dynamic simulation of the process is necessary. Perturbation of the flow rate or temperature in the inlet streams may result in various transient states. An understanding of the dynamic behavior due to these factors is able to support the conceptual design of the secondary helium loop system associated with a hydrogen production plant. Based on the mass and energy balance sheets of an electrodialysis-embedded SI process equivalent to a 200 $MW_{th}$ VHTR and a considerable thermal pathway between the SI process and the VHTR system, a dynamic simulation of the SI process was carried out for a sulfuric acid decomposition process (Second Section) that is composed of a sulfuric acid vaporizer, a sulfuric acid decomposer, and a sulfur trioxide decomposer. The dynamic behaviors of these integrated reactors according to several anticipated scenarios are evaluated and the dominant and mild factors are observed. As for the results of the simulation, all the reactors in the sulfuric acid decomposition process approach a steady state at the same time. Temperature control of the inlet helium is strictly required rather than the flow rate control of the inlet helium to keep the steady state condition in the Second Section. On the other hand, it was revealed that the changes of the inlet helium operation conditions make a great impact on the performances of $SO_3$ and $H_2SO_4$ decomposers, but no effect on the performance of the $H_2SO_4$ vaporizer.

• 대한기계학회논문집
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• 제19권3호
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• pp.697-704
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• 1995

The dynamic characteristics of a system can be critically influenced by system uncertainty, so the dynamic system must be analyzed stochastically in consideration of system uncertainty. This study presents the stochastic model of a nonlinear dynamic system with uncertain parameters under nonstationary stochastic inputs. And this stochastic system is analyzed by a new stochastic process closure method and moment equation method. The first moment equation is numerically evaluated by Runge-Kutta method and the second moment equation is numerically evaluated by stochastic process closure method, 4th cumulant neglect closure method and Runge-Kutta method. But the first and the second moment equations are coupled each other, so this equations are approximately evaluated by a iterative method. Finally the accuracy of the present method is verified by Monte Carlo simulation.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.968-973
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• 2003

Dynamic L/UL system has many merits, but it can develop an undesirable collision during dynamic loading process. In this paper, the dynamics of negative pressure pico slider during the loading process was investigated by numerical simulation. A simplified L/UL model for the suspension system was presented, and a simulation code was built to analyze the motion of the slider. A slider deigns have been simulated at various disk rotating speeds, skew angles of slider. By selection an optimal RPM and pre-skew angle, we can decrease the amount of collision and smoothen the loading process for a given slider-suspension design.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 16-17 Oct. 1987
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• pp.652-657
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• 1987

The Dynamic Matrix Control(DMC) technique was applied to nonlinear and nonminimum phase system. System model was identified by using Least Square method. Desired output trajectory was prespecified and input suppression parameter was also introduced. It was shown that DMC technique worked with great success in solving both nonminimum phase system and nonlinear system.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1998년도 봄 학술발표회 논문집
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• pp.390-397
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• 1998

An approach to identifying input forces is proposed using measured structural dynamic responses and its analytical model. The identification of input forces is a reverse process and ill-conditioned problem. Its solution is unstable and generally case dependent. In this paper, the ill-condition is described considering characteristic matrix which is defined by reduced dynamic stiffness matrix. Special attention is focused on the condition number of a characteristic matrix used in the solution algorithm of this reverse process. Simple example is presented in support of the ill-condition of a reverse process.