• Journal of applied mathematics & informatics
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• 제32권5_6호
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• pp.609-619
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• 2014

Nonsmooth equations with finitely many maximum functions is often used in the study of complementarity problems, variational inequalities and many problems in engineering and mechanics. In this paper, we consider the global convergence methods for nonsmooth equations with finitely many maximum functions. The steepest decent method and the smoothing gradient method are used to solve the nonsmooth equations with finitely many maximum functions. In addition, the convergence analysis and the applications are also given. The numerical results for the smoothing gradient method indicate that the method works quite well in practice.

• Journal of Mechanical Science and Technology
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• 제14권9호
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• pp.1005-1012
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• 2000

Numerical optimization techniques combined with a three-dimensional thin-layer Navier-Stokes solver are presented to find an optimum shape of a stator blade in an axial compressor through calculations of single stage rotor-stator flow. Governing differential equations are discretized using an explicit finite difference method and solved by a multi-stage Runge-Kutta scheme. Baldwin-Lomax model is chosen to describe turbulence. A spatially-varying time-step and an implicit residual smoothing are used to accelerate convergence. A steady mixing approach is used to pass information between stator and rotor blades. For numerical optimization, searching direction is found by the steepest decent and conjugate direction methods, and the golden section method is used to determine optimum moving distance along the searching direction. The object of present optimization is to maximize efficiency. An optimum stacking line is found to design a custom-tailored 3-dimensional blade for maximum efficiency with the other parameters fixed.

• 대한한의학회지
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• 제30권3호
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• pp.111-118
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• 2009

Hysterectomy can lead to various symptoms threatening decent quality of life. As the frequency of hysterectomy increases, there are many patients who want to take oriental medicine treatments for complications. Several clinical studies have reported the effectiveness of oriental medicine treatment for post-hysterectomy complications. Out of these symptoms, postoperative nausea and vomiting (PONV, hereafter) are indicated at about 20-40% of frequency within patients with general anesthesia, and they may occur not only during recovery from operation, but also after discharge. Although the incidence of PONV has decreased now thanks to the usage of antiemetics, PONV still causes some difficulties for patients returning to daily life. This study reports two cases of post-hysterectomy complications such as nausea, dizziness, vomiting, general weakness, and coldness of the limbs, which had good responses to herbal medication and acupuncture.

• 경영과학
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• 제17권2호
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• pp.21-37
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• 2000

This study proposes a Web Decision Support System (DSS) as a new approach to resolving conflicts arising at the interface of production and marketing which have traditionally been in conflict with each other. Many researchers studied on the types and resolution mechanisms of conflicts among various organizations and organizational units. However, as global and distributed operations of firms based on the Internet become a commonplace business landscape, these conflict resolution mechanisms are found very difficult to be directly applied. From this perspective, the Web DSS proposed in this study can be claimed to be appropriate for the Internet-based distributed business operations. The current related literature on the production-marketing interface shows that the possible use of the Web DSS approaches has little been studied in spite of the decent amount of research conducted on the coordination of decision making between the two functions. This paper develops the architecture of the Web DSS and demonstrates its effectiveness based on the implementation results.

• 산업공학
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• 제11권3호
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• pp.15-22
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• 1998

A new improved algorithm in edge location to subpixel accuracy using decent-based weight to spatial information is proposed in this paper and applied to automated visual inspection(AVI) system. An application of the new edge operator as an edge detector is also provided and compared with Tabatabai and Lyvers edge detectors. The existing algorithms located edger to subpixel accuracy using least-square or moment-based methods. The algorithms also use only spatial information or grey-level values to locate edges. However, the proposed algorithm consider the weighted sum of grey-levels values of each edge pattern. The results show that the proposed algorithm is relatively less biased and has smaller standard deviation than the edge operations developed by Tabatabai and Lyvers in the presence of noise.

• 한국조명전기설비학회지:조명전기설비
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• 제9권6호
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• pp.71-77
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• 1995

This paper deals with design method of learning fuzzy controller for control of an unknown nonlinear plant using the self-tuning algorithm of fuzzy inference rules. In this method the fuzzy identification model obtained that the joined identification model of nonlinear part and linear identification model of linear part by fuzzy inference systems. This fuzzy identification model ordered self-tuning by Decent method so as to be servile to nonlinear plant. A the end, designed learning fuzzy controller of fuzzy identification model have learning structure to model reference adaptive system. The simulation results show that th suggested identification and learning control schemes are practically feasible and effective.

• 조명전기설비학회논문지
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• 제27권7호
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• pp.17-23
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• 2013

The regulation of currents in a three-phase load is an important issue for electric power systems. The most popular conventional method is a decoupling controller that compensates the coupling terms arising from DQ rotating frame transformation. Although the decoupling controller achieves decent performance in the absence of load parameter uncertainties, the variation of parameters causes performance to degrade intolerably. In this paper, we propose to use disturbance observer based controller to improve the control performance in spite of the parameter uncertainties. The computer simulation study validates the effectiveness of the proposed method.

• 시스템엔지니어링학술지
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• 제12권2호
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• pp.115-125
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• 2016

An improved RRS (Reactor Regulating System) logic is implemented in this work using systems engineering approach along with GA (Genetic Algorithm) deemed as providing an optimal solution to a given system. The current system works desirably and has been contributed to the safe and stable NPP operation. However, during the ascent and decent section of the reactor power, the RRS output reveals a relatively high steady state error and the output also carries a considerable level of overshoot. In an attempt to consolidate conservatism and minimize the error, this research proposes applying genetic algorithm to RRS and suggests reconfiguring the system. Prior to the use of GA, reverse-engineering is implemented to build a Simulink-based RRS model and re-engineering is followed to apply the GA and to produce a newly-configured RRS generating an output that has a reduced steady state error and diminished overshoot level.

• International Journal of Contents
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• 제9권1호
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• pp.11-17
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• 2013

Recently, online real-time web accessible mobile devices such as smartphones, tablet PCs and application services have been developing rapidly. Hospitals also need to adopt an efficient information system that can provide decent medical services under mobile computing environments to complete future medical services. This study proposes a system in which a doctor can examine a patient and make out a prescription in a ward on a real-time based on the current Order Communication Systems (OCSs) through mobile interfaces. The proposed system implements mobile web pages using HTML5, instead of a mobile app. Web processing speed can be enhanced using the web socket and web storage functions of HTML5.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2011년도 추계학술논문집 2부
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• pp.385-388
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• 2011

This study is about development of remote controlled bollard using the BLDC motor mechatronics theory. A bollard is composed of the sensor part and the control part. The sensor part is consisted of sensors that detect the locations of a bollard. The role of the control part are adjusting motor speed and power through variable resistance. In order to confirm required performance, The speed of decent and ascent of the bollard, the time and the RPM of BLDC motor were tested according to the variable resistance and the load.