• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.117-119
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• 2005

For large structural eigen-analysis, the whole structure is divided into some partitioned structures and through synthesis of partitioned structural model the eigen-data of structure can be obtained. In that case, eigenvalue problem consists of semidefinite mass matrix form because of displacement constraint condition. In this work the eigenvalue problem is considered by means of several method, determinant search and null space reduction method.

• 한국컴퓨터정보학회논문지
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• 제21권4호
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• pp.25-30
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• 2016

We consider energy efficient transmit and receive strategy for a delay sensitive data. More specifically, we investigate an energy optimum scheduling characteristics for the 2 user interference channel where each user interferes to each other. First, we determine the optimum transmission rate region each individual user may have for optimum transmission. Next, we consider the optimum transmission region of two users together. Shortest path algorithm can be used for further reduction of search space. Eventually, we can reduce computational complexity. We then examine the performance of the optimum transmission strategy for various system environments.

• 한국데이터정보과학회:학술대회논문집
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• 한국데이터정보과학회 2004년도 추계학술대회
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• pp.63-75
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• 2004

The decision tree approach is most useful in classification problems and to divide the search space into rectangular regions. Decision tree algorithms are used extensively for data mining in many domains such as retail target marketing, fraud dection, data reduction and variable screening, category merging, etc. We analyze Gyeongnam social indicator survey data using decision tree techniques for environmental information. We can use these decision tree outputs for environmental preservation and improvement.

• Journal of the Korean Data and Information Science Society
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• 제15권4호
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• pp.759-771
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• 2004

The decision tree approach is most useful in classification problems and to divide the search space into rectangular regions. Decision tree algorithms are used extensively for data mining in many domains such as retail target marketing, fraud dection, data reduction and variable screening, category merging, etc. We analyze Gyeongnam social indicator survey data using decision tree techniques for environmental information. We can use these decision tree outputs for environmental preservation and improvement.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2003년도 춘계 학술대회 학술발표 논문집
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• pp.63-66
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• 2003

본 논문에서는 다면체의 인식을 위하여 사용되는 여러-방향-보기 방법 (multiple-view approach)에서 모델베이스의 탐색공간 크기를 줄이기 위한 방법을 제시한다. 이 방법에서 모델베이스는 물체를 둘러싸고 있는 보기 구 (view sphere)의 미리 정해진 보는 곳(viewpoint)에서 보여지는 2차원 투영체들로 구성된다. 물체를 인식하기 위하여 개략-상세 전략을 채택하되, 본 논문에서는 모델베이스의 개략 탐색을 위하여 ART-1을 이용하는 방법은 제시한다.

• Nuclear Engineering and Technology
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• 제25권2호
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• pp.193-203
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• 1993

재장전노심의 핵연료 장전모형 설계를 위한 기존의 알고리즘 탐색방법의 단점을 보완하기 위한 새로운 경험적 탐색방법을 개발하였다. 노심의 핵연료 장전모형으로 고려될 수 있는 수없이 많은 경우의 수를 줄이기 위하여 일반적 핵연료 배치규칙, 영역별 배치방법 그리고 장전모형의 집단화 방법을 이용하였다. 비슷한 장전모형을 모아서 집단화시키는 기준으로 엔트로피 이론을 이용하였다. 또한 PROLOG언어를 이용하여 주어진 배치규칙에 따라 장전모형을 탐색하는 프로그램을 만들었다. 장전모형들의 노심내 출력분포 해석에는 2군 nodal코드인 MEDIUM-2D를 사용하였다. 이와같은 방법을 사용한 결과 수백개 정도의 장전모형 집단을 찾아낼 수 있었고, 여기에 가연성 독봉 배치규칙에 따라 가연성 독봉을 배치한 결과 장전모형 집단의 수를 수십개까지로 감소시킬 수 있었다. 이러한 장전모형 집단들로부터 실제로 이용 가능한 장전모형을 찾아내기 위하여, 주기길이 최대화방법과 첨두 출력 최소화방법을 사용하였다. 그 결과 고리 3호기 제10주기의 예상 재장전모형보다 주기길이는 길고 첨두출력은 낮은 장전모형을 찾아낼 수 있었다.

• Steel and Composite Structures
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• 제25권4호
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• pp.485-496
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• 2017

In this paper, damage detection has been introduced as an optimization problem and a two-step method has been proposed that can detect the location and severity of damage in truss structures precisely and reduce the volume of computations considerably. In the first step, using the residual force vector concept, the suspected damaged members are detected which will result in a reduction in the number of variables and hence a decrease in the search space dimensions. In the second step, the precise location and severity of damage in the members are identified using the genetic algorithm and the results of the first step. Considering the reduced search space, the algorithm can find the optimal points (i.e. the solution for the damage detection problem) with less computation cost. In this step, the Efficient Correlation Based Index (ECBI), that considers the structure's first few frequencies in both damaged and healthy states, is used as the objective function and some examples have been provided to check the efficiency of the proposed method; results have shown that the method is innovatively capable of detecting damage in truss structures.

• Smart Structures and Systems
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• 제25권3호
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• pp.345-368
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• 2020

The present work proposes a self-controlled multi-stage optimization method for damage identification of structures utilizing standard particle swarm optimization (PSO) algorithm. Damage identification problem is formulated as an inverse optimization problem where damage severity in each element of the structure is considered as optimization variables. An efficient objective function is formed using the first few frequencies and mode shapes of the structure. This objective function is minimized by a self-controlled multi-stage strategy to identify and quantify the damage extent of the structural members. In the first stage, standard PSO is utilized to get an initial solution to the problem. Subsequently, the algorithm identifies the most damage-prone elements of the structure using an adaptable threshold value of damage severity. These identified elements are included in the search space of the standard PSO at the next stage. Thus, the algorithm reduces the dimension of the search space and subsequently increases the accuracy of damage prediction with a considerable reduction in computational cost. The efficiency of the proposed method is investigated and compared with available results through three numerical examples considering both with and without noise. The obtained results demonstrate the accuracy of the present method can accurately estimate the location and severity of multi-damage cases in the structural systems with less computational cost.

• 실천공학교육논문지
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• 제15권2호
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• pp.321-330
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• 2023

본 논문에서는 특정 도메인의 온톨로지 구성에 필요한 용어 간의 다양한 관계를 추출하여 자동으로 온톨로지를 생성하는 방법을 제안하고자 한다. 추출된 관계를 온톨로지의 구조에 공리 집합으로 인코딩하여 온톨로지로 구성한다. 효율적으로 해결하기 위해 집합의 검색 공간을 정수 프로그래밍 문제로 표현하며, 최적화를 위해 별로 도움이 되지 않는 규칙은 제거하는 단순한 축소를 사용하여 행렬을 감소시킨다. 결론적으로 본 논문에서는 주어진 데이터를 이용하여 패턴을 일반화하고, 유용한 패턴을 유지하면서 검색 공간을 줄이는 방법을 제시하며, 구조화된 온톨로지로 구성하는 알고리즘을 적용하여 추출된 관계를 이용해 자동으로 효율적인 온톨로지로 생성하는 방법을 제안한다.

• 한국기계가공학회지
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• 제9권6호
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• pp.21-28
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• 2010

This study shows an optimization procedure for an automatic determination on the gate position to ensure the fill-uniformity within a part cavity by using the injection molding simulation. For an optimization, the maximum pressure-difference within a part cavity induced at the stage of filling is used to evaluate degree of fill-uniformity. In addition, a direct search scheme based on the reduction of design space is developed and applied in the optimization problem. This corresponding proposed methodology was applied in the optimization on the gate location for a CD-tray molding, as a result, showed the improvement of the fill-uniformity within the cavity.