• 전기의세계
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• 제23권1호
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• pp.73-78
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• 1974

Digital simulation algorithms and program for multimachine dynamic stability have been developed which represent the effects of machines much more complety than have been available previously. Emphasis is given to the savings of the memory spaces required, thus making it possible to use a small computer with limited capacity of core storage (without auxiliary storage). Both d- and q- aris quantities are fully represented, and the speed-governing and voltage-regulating system available are ertensive, thus allowing a very close approximation to any physical system. Facilities for dynamic and nonlinear loads are also included. The computational algorithms and program developed have been shown to be extensive and complete, and are very desirable features minimizing memory spaces for stability calculations. The capabilities have been demonstrated by several case studies for an actual power system of 44 generators, 22 loads and 33 buses. About 13-K words of memory spaces have been required for the case studies on the basis of two words per real variable and a word per integer variable.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.556-562
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• 2000

This paper presents new sensitivity analysis algorithm for the dynamic response of three dimensional rectilinear type structure. This method is derived from a combination of the transfer stiffness coefficient method(TSCM) and the Newmark method. We developed dynamic response analysis algorithm by TSCM. This method has more safe computational precision and time than transfer matrix method(TMM). We defined new design variable and object function, and computated simple three dimensional computation model by TSCM. The presented analysis algorithm was validated by results of changing design variable.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.688-693
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• 2002

Identification method is formulated to evaluate the dynamic characteristics of air bearings under NFR(Near Field Recording) sliders. Impulse responses and frequency response functions of NFR sliders are obtained on numerical non-linear models including rigid motion of slider and fluid motion of air bearing under the slider. Modal parameters and system parameters are identified by modal analysis method and instrumental variable method. The parameters of sliders are utilized to evaluate the dynamic characteristics of air bearings. Also, this study shows the difference between the dynamic characteristics of NFR and HDD slides, and squeeze effect of air bearings.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.104-108
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• 2002

In this study, the dynamic absorbing system for the shoulder-fired system with high-level-impact force has been investigated. for this purpose, firstly, mathematical model based on the short recoil system has been constructed. In order to design the dynamic absorbing system, parameter sensitivity analysis and parameter optimization process have been performed under constraints of moving displacement and transmitted force. In order to enhance the efficiency of energy dissipation, the stroke-dependent variable damping system has been analyzed. finally, the performance of the designed dynamic absorbing system has been evaluated by simulation with respect to the benchmark system.

• 한국시스템다이내믹스연구
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• 제4권1호
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• pp.5-31
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• 2003

Customer satisfaction is generally assumed to be a significant determinant of repeat sales, positive word-of-mouth, and customer loyalty. Therefore most companies in telecommunication industry have tried to satisfy customers with high quality at low price in Korea. Even though these efforts have been tried by companies, customers are not satisfied with discrepancy between their expectation and perceived quality. Moreover, the expectation has dynamic and variable characteristics in results from various effects such n technical progress, improved quality and promotions by companies, word-of-mouth, and so on, Therefore, there are not political leverages in assessing the quality and surveying customer satisfaction index in a point of time. As an initial attempt to tackle the questions listed above, this paper puts an effort to make a dynamic customer satisfaction model to understand customer satisfaction in variable situations by introducing 'systems thinking'.

• 전기의세계
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• 제28권1호
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• pp.59-66
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• 1979

The linearized models on per for mance dynamics of the pulse motor have been already proposed by many others. These models exhibit certain advantages of their own because of their simple formulation, but in many cases the models are proved to be inadequate for further accurate analysis of the motor dynamics, owing to impractical and rather rough assumptions in the derivation. In this study a dynamic state transition model is induced, using the equivalent circuit obtained from the operating principle of the variable reluctance pulse motor which turns out to be nonlinear equation. This nonlinear dynamic state equation is numerically analysed by the use of UNIVAC System/3(OS/3) digital computer at hand. In the course of the dynamic analysis of the performance characteristics of a testing motor, dependance of the inertia of rotor and load, the coefficient of viscous friction between rotor and housing, and the winding resistance of the stator is discussed and a comparative study of the machine constants is carried on as related to the design problem of the motor.

• Communications for Statistical Applications and Methods
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• 제9권3호
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• pp.787-797
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• 2002

Partial residual plots, augmented partial residual plots and CERES plots are basic diagnostic tools for dealing with curvature as a function of specific predictors in regression problem. However, it is known that these plots can miss a curve or show a false curve in some cases such as predictors are related each other. Dynamic display of these plots is developed and applied. Examples demonstrate that dynamic plots are useful for obtaining additional Information on the curvature.

• 전기의세계
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• 제29권1호
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• pp.58-64
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• 1980

In this paper, this objective is to obtain the mathematical model which describes the dynamic characteristics of variable reluctance(VR) step motor, the most important and most widely used motor in practice. In the development of the mathematical model for VR step motor, first the general nonlinear dynamic equations which describe the N-phase VR step motor are derived. These general equations are then applied to the multiple-step type of VR step motor in case, for simplicity, maynetic saturation and core lossess in the iron are neglected. These nonlinear dynamic equations are numerically analysed by the computer simulation, through which the performance characteristics of a step motor undertest are investigated under the various operating conditions.

• 대한산업공학회지
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• 제31권3호
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• pp.194-200
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• 2005

A stochastic dynamic lot sizing problem for multi-item is suggested in the case that the distribution of the cumulative demand is known over finite planning horizons and all unsatisfied demand is fully backlogged. Each item is produced simultaneously at a variable ratio of input resources employed whenever setup is incurred. A dynamic programming algorithm is proposed to find the optimal production policy, which resembles the Wagner-Whitin algorithm for the deterministic case problem but with some additional feasibility constraints.

• 한국통계학회:학술대회논문집
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• 한국통계학회 2005년도 추계 학술발표회 논문집
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• pp.167-173
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• 2005

This paper presents an autocorrelation test that is applicable to dynamic panel data models with serially correlated errors. The residual-based GMM t-test is a significance test that is applied after estimating a dynamic model by using the instrumental variable(IV) method and is directly applicable to any other consistently estimated residuals. Monte Carlo simulations show that the t-test has considerably more power than the $m_2$ test or the Sargan test under both forms of serial correlation (i.e., AR(1) and MA(1)).