• 대한기계학회논문집A
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• 제25권12호
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• pp.1926-1932
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• 2001

In this second part of the paper, the automatic mesh generation and remeshing algorithm using bubble packing method is applied to the nonlinear problem. The remeshing/refinement procedure is necessary in the large deformation process especially because the mesh distortion deteriorates the convergence and accuracy. To perform the nonliear analysis, the transfer of state variables such as displacement and strain is added to the algorithm of Part 1. The equilibrium equation based on total Lagrangian formulation and elasto-viscoplastic model is used. For the numerical experiment, the upsetting process including the contact constraint condition is analyzed by two refinement criteria. And from the result, it is addressed that the present algorithm can generate the refined meshes easily at the largely deformed area with high error.

• Journal of Mechanical Science and Technology
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• 제19권spc1호
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• pp.364-370
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• 2005

A stable walking pattern generation method for a biped robot is presented in this paper. In general, the ZMP (zero moment point) equations, which are expressed as differential equations, are solved to obtain a stable walking pattern. However, the number of differential equations is less than that of unknown coordinates in the ZMP equations. It is impossible to integrate the ZMP equations directly since one or more constraint equations are involved in the ZMP equations. To overcome this difficulty, DAE (differential and algebraic equation) solution method is employed. The proposed method has enough flexibility for various kinematic structures. Walking simulation for a virtual biped robot is performed to demonstrate the effectiveness and validity of the proposed method. The method can be applied to the biped robot for stable walking pattern generation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 D
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• pp.1060-1063
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• 1997

A new generation planning algorithm considering environmental constraint by using fuzzy technique is developed. This algorithm has a new formula which can consider environmental constraints and an effective solving method which has newly developed fuzzy dual procedure. By using this algorithm, economic generation planning considering environmental constraints can be scheduled. The usefulness of this method is verified by applying it to the test system.

• 대한전기학회논문지
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• 제41권8호
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• pp.831-840
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• 1992

This paper presents an efficient short-term generation scheduling method using a rule-based expert/consulting system approach to assist electric energy system operators and planners. The expert system approach is applied to improve the Dynamic Programming(DP) based generation scheduling algorithm. In the selection procedure of the feasible combinations of generating units at each stage, automatic consulting on the manipulation of several constraints such as the minimum up time, the minimum down time and the maximum running time constraints of generating units will be performed by the expert/consulting system. In order to maximize the solution feasibility, the aforementioned constraints are controlled by a rule-based expert system, that is, instead of imposing penalty cost to those constraint violated combinations, which sometimes may become the very reason of no existing solution, several constraints will be manipulated within their flexibilities using the rules and facts that are established by domain experts. In this paper, for the purpose of implementing the consulting of several constraints during the dynamic process of generation scheduling, an expert system named STGSCS is developed. As a building tool of the expert system, C Language Integrated Production System(CLIPS) is used. The effectiveness of the proposed algorithm has been demonstrated by applying it to a model electric energy system.

• 공학논문집
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• 제6권1호
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• pp.5-14
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• 2004

제약조건을 만족시키기 위한 문제에서 해를 얻는 일은 그 문제의 조건들을 만족시키기 위한 변수들의 값을 선정하는 것이다. 이것은 주어진 영역내의 다수의 불확정적인 변수들의 논리적 관계를 탐색하여 조건을 만족하는 최적의 해를 얻는 것이다. 그러나, 이러한 문제들의 해를 구하는 과정에는 두 가지 큰 문제를 내포한다. 즉, 다양한 형태와 다수의 속성을 지닌 제약 조건들을 시스템내부에 효율적으로 표현하는 방법이 어렵고, 탐색과정에서 기하급수적으로 발생하는 공간문제와 처리시간을 최소화 하기가 힘들다. 그 이유는, 적절한 제약 조건의 표현방법과 효율적인 알고리즘에 의해 스케줄링을 한다 해도 모든 조건들을 항상 다 만족시킬 수는 없기 때문이다. 즉, 제약 조건 내에 충돌의 요소가 있을 수도 있기 때문이다. 따라서 이 논문에서는, 스케줄링을 진행하는 과정에서 이러한 제약 조건위반(충돌)에 대한 정보 및 차선의 조건을 사용자에게 제시하여 사용자로 하여금 조건의 재조정이 가능하도록 하는 대화형 스케줄링시스템의 모델을 제시한다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.361-364
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• 1997

The re-enty guidance design involves trajectory optimization, generation of a reference drag acceleration profile with the satisfaction of trajectory constraints. This reference drag acceleration profile can be considered as the reference trajectory. This paper proposes the atmospheric re-entry system which is composed of longitudinal, later and range control. This paper shows the a performance of a re-entry guidance and control system using feedback linearization control and predictive control.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1993년도 Fifth International Fuzzy Systems Association World Congress 93
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• pp.861-864
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• 1993

This research provides the results of a trial to generate the chaos by using nonlinear function constructed by fuzzy inference rules. The chaos generation function or chaotic behavior can be obtained by using Takagi-Sugeno fuzzy model with some constraint of the relationship of its parameters. Two examples are shown in this research. The first is simple example that construct of logistic image by fuzzy model. The second is more complicated one that provide the chaotic time series by non-linear autoregression based on fuzzy model. Simulated results are shown in these examples.

• Journal of information and communication convergence engineering
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• 제8권2호
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• pp.191-196
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• 2010

This paper presents automatic generation of robot motion using posture template in physical training system. In this system, we define a human-like generic template with two angles, then, we generate robot motion that has used angle data of the created template. The angle data is transformed automatically to the most similar motion. This is achieved by suitable expressions for robot specification. The expressions intend to differences of angle measurement on X,Y,Z planes and DOF constraint. We choose several postures and create generic templates for chosen postures. Robot motions are also generated from generic templates by expressions.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.274-276
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• 2005

Stability is an important constraint in powr system operation. A new methodology that reduces the need for repeated simulation to determine a transiently secure operating point is presented. at cntingency, critical generator is limited generation to prevent rotor accelation until system is secured. when energh margin is zero, generation is degermined Implementation issues and simulation results are discussed in th context of a 10-bus system.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2007년도 춘계학술발표대회
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• pp.31-33
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• 2007

Devising an efficient one-pass frequent pattern mining algorithm has been an issue in data mining research in recent past. Pattern growth algorithms like FP-Growth which are found more efficient than candidate generation and test algorithms still require two database scans. Moreover, FP-growth approach requires rebuilding the base-tree while mining with different support counts. In this paper we propose an item-based tree, called I-Tree that not only efficiently mines frequent patterns with single database scan but also provides multiple mining scopes with multiple support thresholds. The 'build-once-mine-many' property of I-Tree allows it to construct the tree only once and perform mining operation several times with the variation of support count values.