• JSTS:Journal of Semiconductor Technology and Science
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• 제9권4호
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• pp.209-215
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• 2009

Reconfigurable array architecture is recently attracting much attention. It is a flexible hardware architecture, which can dynamically change its configuration to execute various functions while maintainning high performance. However, pursuing flexibility and performance at the same time leads to complexity, thereby makes the mapping of applications a difficult process. There have been attempts to use compiler or high level synthesis techniques to solve the problem. In this paper, we propose yet another method, which uses libraries for the mapping to provide an abstracttion of the internal structure and at the same time to reduce the development time and efforts through the automated process. We have selected a JPEG decoder as an example to apply the proposed method. As a result, we obtained about 20% less performance compared to manual mapping but development time is dramatically reduced to less than 1%.

• 대한기계학회논문집A
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• 제24권2호
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• pp.319-328
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• 2000

This paper presents a new design method of the 1 generation wheel bearing unit using a numerical optimization technique in order to increase bearing fatigue life. For calculating the fatigue life, a method of load analysis is studied on the automotive wheel bearing system. The design variables selected are ball size, initial contact angle, number of balls, pitch diameter, pre-load, and distance between ball centers. The method of feasible directions in ADS (Automated Design Synthesis) is utilized to automatically find the optimum design variables. To validate the design method, a computer program is developed and applied to a practical passenger car model. The optimum design results demonstrated the effectiveness of the proposed design method showing that the system life of the optimally designed wheel bearing unit is enhanced in comparison with that of the initial ones within the given available design space.

• 한국경영과학회지
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• 제13권1호
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• pp.51-64
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• 1988

A new approach to the logical design of 4NF database shceme, which can be easily automated, is proposed. The main features of the approach are : introduction of a single attribute right hand side, extension of the concept of independent relations, semantic analysis, and adaoption of dependency matrix. The underlying viewpoints of functional relationships of the approach are different from Fagin's in that we distinguish functional and multivalued dependency in terms of cardinality. An algorithm for automatic generation of fourth normal form is presented and implemented.

• 한국해양공학회지
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• 제17권6호
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• pp.16-22
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• 2003

In this paper, the method of determining the economically-optimal design section of rubble mound breakwater, using ADS program, was studied to supplement the deterministic approach. First of all, the design waves are computed, according to the return periods, using the Weibull distribution from the data of waves at the location of the breakwater. In order to take an optimal section, according to the return periods, the ADS program was used. The restriction conditions and objective functions are decided from the references of the specifications and standard manuals for Coastal and Harbor Construction Work. Results from this study support the ADS program as an appropriate method for determining the economically-optimal section of rubble mound breakwater, comparing the construction costs and the initial and damage repair costs for its life time.

• 한국산학기술학회논문지
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• 제4권3호
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• pp.159-163
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• 2003

본 논문에서는 복합적층 평패널의 최소중량화설계를 수행하기 위하여 길이방향 보강재로 보강된 평패널에 축압축 하중이 작용할 경우 좌굴하중을 구한다. 또한 좌굴에 대한 최소중량화설계를 유한차분에너지법을 이용한 선형좌굴이론과 비선형좌굴이론에 의해서 구하고 비선형 탐색 최적설계기법 ADS를 활용하여 해석한다. 복합적층 평패널의 종횡비는 1, 3, 7에 대하여 고려하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.330-335
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• 1993

This paper presents an efficient solution for a class of forbidden state problems by introducing a cyclic timed controlled marked graphs (TCMG's), a special class of timed controlled Petri nets (TCPN's) as a model of a class of discrete event systems (DES's). The state feedback control is synthesized, which is maximally permissive while guaranteeing the forbidden states will be avoided. The practical applications or tire theoretical results for an automated guided vehicle (ACV) coordination problem in a flexible manufacturing facility is illustrated.

• Journal of information and communication convergence engineering
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• 제6권1호
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• pp.59-63
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• 2008

The methods or algorithms which can accelerate simulation speed became of great importance, as the modeling and simulation methodology for discrete event systems is used in many areas such as model validation/verification and performance evaluation. This paper proposes a tool named, DEVSIF composer. The tool is made of an automated compiled simulation technology and it builds a new composed model which can be executed much fast by composing the component models together. Models are described by our new specification language DEVSIF, which is compatible with object-oriented language and supports representation of a hierarchical model structure. Experimental results demonstrates that DEVSIF composer enhances the simulation speed of a transformed DEVS model 5 times faster than that of the original ones in average.

• 제어로봇시스템학회논문지
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• 제8권5호
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• pp.401-406
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• 2002

As product lifecycles become shorter, factories are pushed to develop small batches of many different products. The highly flexible control systems has become a necessity. The majority of existing automated industrial systems are controlled by programmable logic controllers(PLCs). In most cases, the control programs for PLCs are developed based on ladder diagrams(LDs). However, it is difficult to debug and maintain those LDs because the synthesis of LD itself mainly depends on the experience of the industrial engineer via trial-and-error methods. Hence, in this paper, we propose a discrete event model conversion algorithm for systematic analysis of LDs. The proposed discrete event model conversion algorithm is illustrated by an example of a conveyor system.

• 한국공작기계학회논문집
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• 제12권6호
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• pp.71-76
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• 2003

Optimal design of panel with trapezoidal type stiffeners was studied using linear and nonlinear deformation theories. Also analysis method was using closed-form analysis and finite difference energy methods, respectively. Various bucking load factors are obatined for stiffened laminated composite panel with trapezoidal type stiffeners and various aspect ratios, which are made from Carbon/Epoxy USN 125 prepreg and are simply-supported on four edges under uniaxial compression. Optimal design analyses are carried out by the nonlinear search optimizer, ADS.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1999년도 가을 학술발표회 논문집
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• pp.143-150
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• 1999

The LRFD Specification defines two sets of limiting width-to-thickness ratios. On the basis of these limiting values, steel sections we subdivided into three categories: compact, noncompact, and slender sections. A compact section is capable of developing a fully plastic stress distribution (plastic moment), and can sustain rotations approximately three times beyond the yield before the possibility of local buckling arises. Noncompact sections can develop the yield stress before local buckling occurs. They may not, however, resist local buckling at the strain levels required to develop the fully plastic stress distribution. In this paper, 1-Type girders of a 2 span continuous steel bridge are divided into compact and non-compact sections and analyzed. In the design process, an optimization skill was adopted and ADS, a Fortran program for Automated Design Synthesis, was used.