• 한국수학교육학회지시리즈D:수학교육연구
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• 제8권3호
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• pp.145-155
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• 2004

Mathematics, by its nature, is a creative activity. Creativity can be developed either through considering its intrinsic beauty or by examining the role that it plays in applications to real world problems. Many of the great mathematicians have been vitally interested in applications and gained inspiration in developing new mathematics from the mathematical descriptions of physical phenomena. In this paper we will examine the processes of applying mathematics by looking at how mathematical models are formed and used. Applications from sport, the environment and populations are used as illustrations.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.61.6-61
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• 2002

In these days, Block Pulse functions are used in a variety of fields such as the analysis and controller design of the systems. In applying the Block Pulse function technique to control and systems science, the integral operation of the Block Pulse series plays important roles. This is because differential equations are always involved in the representations of continuous-time models of dynamic systems, and differential operations are always approximated by the corresponding Block Pulse series through integration operational matrices. In order to apply the Block Pulse function technique to the problems of continuous-time dynamic systems more efficiently, it is necessary to find th...

• 한국정보시스템학회지:정보시스템연구
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• 제4권
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• pp.181-209
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• 1995

As the effective use of information has gained greater attention over the decade, various conventional AI techniques have been applied to develop expert systems for business applications. Case-based reasoning (CBR) makes data more accessible by organizing it as a set of examples from past experience that can be generalized and applied to current problems. This paper illustrates basic concepts of CBR and addresses the system discussed in this paper can provide a basis for building more flexible and adaptable expert systems for business applications.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.239-240
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• 2007

In this paper, a robust adaptive backstepping controller will be proposed for the speed control of permanent magnet synchronous motors in using electrical vehicles. Stator resistance, damping coefficient, load torque are considered as uncertainties and noise generated at applying load torque to motor is also considered. It shows that the backstepping algorithm can be used to solve the problems of nonlinear system very well and robust controller can be designed without the variation of adaptive law. Simulation results are provided to demonstrate the effectiveness of the Proposed controller.

• 시스템엔지니어링학술지
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• 제2권2호
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• pp.21-26
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• 2006

In modern systems technology, increasingly more systems are anticipated to operate in real-time environment. These systems are usually complex to implement since it is not easy to satisfy the real-time requirement for both hardware and software components simultaneously. In this paper, we first review an object-oriented development process that was proposed earlier for software-intensive real-time system using the Unified Modeling Language (UML). We then study how to improve the problems that the UML approach might have. Applying the systems engineering(SE) process yields useful results which include : 1) an improved requirements management over the whole system life-cycle ; 2) a detailed scenario on how to carry out the SE process ; and 3) a conversion process from the text-based requirements to the UML-based graphic ones.

• 전기의세계
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• 제18권3호
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• pp.7-14
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• 1969

According to the construction of Seoul Thermal #5 (250MW) unit, there will be prospected several new problems on the power system operation. This paper describes the characteristic of system frequency decay during severe emergencies which result in sudden outage of such large generator unit. It also studies the factors involved in applying under frequency relays to maintan an allowable frequency level and to prevent total area collapse by automatic load shedding program.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.46.4-46
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• 2002

This study was motivated how it might be possible to validate structured sampling with orthogonal array for optimal design of a pin. The Taguchi method by orthogonal array, one of the structured sampling methods, has much advantage that is row cost and time saving for experiments. But this method has been applied in limited areas especially for mechanical problems. In this study, we experimented whether the structured sampling is useful for applying optimal design of mechanical elements. For the experiment, we first set up a mechanical problem which was related to determining optimal parameters associated a pin's crack occurred inside a hole. We, then, calculated combination of...

• 산업경영시스템학회지
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• 제18권36호
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• pp.219-232
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• 1995

Even though Just-In-Time Production System is introduced to industry in order to strengthen competition, applying this production system to field is hard and some problems are occurred. On this study, the algorithm which become smoothed production, one of the prerequisite condition for implementing Just-In-Time, are developed. On the other word. it is possible to become smoothed production based on keeping Lot Production System. The possibility of establishing more stable smoothed production scheduling are proved on this study by comparing with previous researches.

• 대한물리치료과학회지
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• 제31권1호
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• pp.53-69
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• 2024

Background: This study aims to examine the multiple-parallel mediation effects of depression, anxiety, and anger in the relationship between anger-out and interpersonal problems in men. In addition, the purpose of this study was provide a basis for supporting psychological services alongside therapeutic services as a way to increase the overall interpersonal relationship of men. Design: Survey. Methods: This study targeted 208 adult men aged 20 to 59 years. Participants were recruited through online cafe postings, and data were collected by running an online survey link. Based on the collected data, correlations between variables were investigated, and multiple parallel mediation analysis was performed using the model (Model 4) presented by SPSS PROCESS Macro. In addition, the significance of statistics was confirmed by applying the bootstrapping method, and the significance of the indirect effect was confirmed by the Sobel Z test. Results: First, Anger-out in men is related to interpersonal problems(β=.614, P<.001). Second, it can see that anger-out not only increases depression·anxiety, but also increases anger. Third, Anger-out has been shown to increase depression, anxiety, and anger, leading to increasing interpersonal problems. Anger-out had a significant effect on depression, anxiety(β=.324 P<.001), and anger(β=.551, P<.001), and depression, anxiety(β=.239, P<.001), and anger (β=.318, P<.01) had a significant effect on interpersonal relationship problems. Lastly, it can be seen that men's anger-out is experienced more as anger than depression or anxiety. Conclusion: When providing medical services to men, I believe that if externally expressed anger is addressed along with therapeutic treatment, invisible depression can also be intervened and a more positive prognosis can be expected

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집B
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• pp.709-714
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• 2000

A splitting method for the direct numerical simulation of solid-liquid mixtures is presented, where a symmetric pressure equation is newly proposed. Through numerical experiment, it is found that the newly proposed splitting method works well with a matrix-free formulation fer some bench mark problems avoiding an erroneous pressure field which appears when using the conventional pressure equation of a splitting method. When deriving a typical pressure equation of a splitting method, the motion of a solid particle has to be approximated by the 'intermediate velocity' instead of treating it as unknowns since it is necessary as a boundary condition. Therefore, the motion of a solid particle is treated in such an explicit way that a particle moves by the known form drag (pressure drag) that is calculated from the pressure equation in the previous step. From the numerical experiment, it was shown that this method gives an erroneous pressure field even for the very small time step size as a particle velocity increases. In this paper, coupling the unknowns of particle velocities in the pressure equation is proposed, where the resulting matrix is reduced to the symmetric one by applying the projector of the combined formulation. It has been tested over some bench mark problems and gives reasonable pressure fields.