• 전자공학회논문지A
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• 제31A권3호
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• pp.68-76
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• 1994

In the automatic transistor sizing with computer for optimizing delay and the chip area of CMOS digital circuits, conventionally either a mathematical method or a heuristic method has been used. In this paper, we present a new method of transistor sizing, a sort of combination of the above two methods, in which the mathematical method is used for sizing of critical paths and the heuristic method is used for desizing of non-critical paths. In order to reduce the overall problem dimension, a basic block called an extended stage is introduced which includes a basic stage, parallel transistors and complementary part. Optimization for multiple critical paths is formulated as a problem of area minimization subject to delay constraints and is solved by the augmented Lagrange multiplier method. The transistor sizes along non-critical paths are decreased successively without affecting the critical path delay times. The proposed scheme was successfully applied to several test circuits.

• 대한의용생체공학회:의공학회지
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• 제44권6호
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• pp.428-442
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• 2023

In this study, we have a goal to develop usability evaluation guidelines for heuristic-based artificial intelligence-based Software as a Medical Device (SaMD) in the medical field. We conducted a gap analysis between medical hardware (H/W) and non-medical software (S/W) based on ten heuristic principles. Through severity assessments, we identified 69 evaluation domains and 112 evaluation criteria aligned with the ten heuristic principles. Subsequently, we categorized each evaluation domain into five types, including user safety, data integrity, regulatory compliance, patient therapeutic effectiveness, and user convenience. We proposed usability evaluation guidelines that apply the newly derived heuristic-based Software as a Medical Device (SaMD) evaluation factors to the risk management process. In the discussion, we also have proposed the potential applications of the research findings and directions for future research. We have emphasized the importance of the judicious application of AI technology in the medical field and the evaluation of usability evaluation and offered valuable guidelines for various stakeholders, including medical device manufacturers, healthcare professionals, and regulatory authorities.

• 산업경영시스템학회지
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• 제40권1호
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• pp.11-21
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• 2017

Artillery fire power due to effectiveness which is hard to predict well-planned and surprising attack can give a fear and shock to the personnel and is a very core weapon system and takes a critical role in wartime. Therefore in order to maximize operational effectiveness, Army required protecting artillery and takes a quick attack action through rapid construction of artillery's positions. The artillery use artillery's position to prevent exposure by moving to other position frequently. They have to move and construct at new artillery's positions quickly against exposing existed place by foe's recognition. These positions should be built by not manpower but engineering construction equipment. Because artillery positions have to protect human and artillery equipment well and build quickly. Military engineering battalion have lots of construction equipment which include excavator, loader, dozer, combat multi-purposed excavator, armored combat earthmover dump truck and so on. So they have to decide to optimal number of Team combining these equipments and determine construction sequence of artillery's position in operational plan. In this research, we propose to decide number of Team efficiently and allocate required construction's positions for each Team under constraints of limited equipments and time. To do so, we develop efficient heuristic method which can give near optimal solution and be applied to various situation including commander's intention, artillery position's priority or grouping etc. This heuristic can support quick and flexible construction plan of artillery positions not only for using various composition's equipment to organize Teams but also for changing quantity of positions.

• 한국융합학회논문지
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• 제8권10호
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• pp.19-28
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• 2017

최근 컨테이너 항만에서는 점점 컨테이너선의 대형화에 따라 증가하는 물동량을 처리하기 위해, 하역장비들의 효율적인 배차 계획과 대기시간 최소화를 통해 작업 생산성을 높이는 다양한 방법들을 적용하고 있다. 본 연구에서는 생산성을 높이는 방법으로 기존 휴리스틱 방법론을 개선한 최적화 모형인 솔버(Solvers)를 적용하였다. 실험 계획은 6개의 샘플 문제를 통해 두 가지 목적함수인 공차주행시간 최소화와 지연시간 최소화의 수행 결과를 기존의 휴리스틱 방법론의 결과와 비교하는 것이다. 실험 결과 두 가지 목적함수 모두 6개의 샘플 문제 중에서 4개의 샘플 문제에서 최적화 모형이 휴리스틱 방법론보다 평균 5.3% 향상된 결과를 도출하였다.

• 한국지능시스템학회논문지
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• 제19권4호
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• pp.525-531
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• 2009

데이터 마이닝(Data Mining)은 수집된 데이터로 부터 감춰진 패턴을 찾는 작업이다. 여기에서 수집된 데이터는 예측 및 추천을 위한 기반 정보로 중요한 역할을 하며, 분석 결과의 성능을 향상시키기 위해 잘못된(Missing value) 데이터를 선별하는 과정을 필요로 한다. 수집한 데이터에서 의도하지 못한 데이터를 선별하기 위한 기존의 방법은 주로 통계적이거나 단순 거리(Distance)에 기반을 둔 방법을 이용하였다. 하지만 환경 및 데이터의 특성을 고려하지 못하여, 의미 있는 데이터도 함께 분석에서 제외 될 수 있는 문제점을 가지고 있다. 본 논문은 인간의 경험적 지식을 수집된 데이터와 비교하여 가중치로 변환하고, 의사결정트리(Decision Tree)의 생성에 이용한다. 생성된 트리는 인간의 지식이 반영되어 기존의 분석 방법보다 신뢰성이 높다고 할 수 있으며, 실험을 통하여 제안하는 방법의 유효성을 확인하였다.

• 품질경영학회지
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• 제50권2호
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• pp.265-286
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• 2022

Purpose: The time and cost of a project activity exists in a selected mode and there is a quality level for the selected mode, and the time and cost of the current activity is determined by the quality level of the preceding activity. When an activity is a predecessor activity of an activity, it is characterized as a trade-off problem in which the time and cost of the activity are determined according to the quality level of the activity. Methods: A neighbor search heuristic algorithm obtains a solution by (1) randomly determining the mode, quality level, and assignment order for each activity. (2) get a solution by improving the solution by changing the possible modes and quality levels; (3) to find a solution by improving the solution from the point where it is feasible to advance the start time. Here, Case[1] is a method to find the optimal solution value after repeating (1). Case [2] is a method for finding a solution including (1) and (2). Case [3] refers to a method for finding solutions including (1), (2), and (3). Results: It can be seen that the value of the objective function presented by the algorithm changes depending on how the model of the heuristic algorithm is designed and applied. In other words, it suggests the importance of algorithm design and proves the importance of the quality problem of activities in the project schedule. Conclusion: A study significance of the optimization algorithm and the heuristic algorithm was applied to the effect of the quality of the preceding activity on the duration and cost of itself and the succeeding activity, which was not addressed in the project schedule problem.

• 품질경영학회지
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• 제23권3호
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• pp.156-166
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• 1995

Job shop scheduling problem is a complex system and an NP-hard problem. Thus it is natural to look for heuristic method. We consider the multi-part production scheduling problem for quality level in a job shop scheduling under the existence of alternative routings. The problem is more complex if the processing time is imprecision. It requires suitable method to deal with imprecision. Fuzzy set theory can be useful in modeling and solving scheduling problems with uncertain processing times. Li-Lee fuzzy number comparison method will be used to compare processing times that evaluated under fuzziness. This study presents heuristic method for quality level in bottleneck-based job shop scheduling under fuzzy environment. On the basis of the proposed method, an example is presented.

• 전기학회논문지P
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• 제67권3호
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• pp.131-136
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• 2018

Harmony search (HS) is a relatively recently developed meta-heuristic optimization method imitating the music improvisation process where musicians improvise their instruments' pitches searching for a perfect state of harmony. In the conventional HS algorithm, it is necessary to determine the maximum number of iterations with some algorithm parameters. However, there is no criterion for determining the number of iterations, which is a very difficult problem. To solve this problem, a new method is proposed to perform the algorithm without setting the maximum number of iterations in this paper. The new method allows the algorithm to be performed until the desired tuning is achieved. To do this, a new variable bandwidth is introduced. In addition, the types and probability of harmonies composed of variables is analyzed to help to decide the value of HMCR. The performance of the proposed method is investigated and compared with classical HS. The experiments conducted show that the new method generally outperformed conventional HS when applied to seven benchmark problems.

• 전자공학회논문지
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• 제51권5호
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• pp.76-87
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• 2014

오늘날 ICT 네트워크에서 에너지 소모는 전체 에너지 소모의 10% 내외로, 가까운 미래에 에너지가 현저하게 증가 할 것으로 예측되고 있다. 본 논문에서는 네트워크 품질을 보장하면서 에너지 절감이 가능한 방법을 검토한다. IP 네트워크에서 처리하는 총 트래픽 량이 일정 값 이하가 될 때, 네트워크 내의 특정 링크를 sleep 상태로 하여, 링크 양단의 NIC(Network Interface Card)에서 소모되는 에너지를 절감시키는 방안이다. 본 논문에서는 sleep 상태로 둘 링크를 최대한 도출하고, 이로 인한 노드의 경로(SPT: Shortest Path Tree)변경이 최소화되도록 한다. 우선 target 링크를 선정하고, 선정된 target 링크가 sleep 상태로 두는 것이 가능한지를 위임/수탁 라우터 기반의 heuristic 라우팅 방안에 의해 결정하는 방법을 제안한다. 위임/수탁 라우터 기반의 heuristic 라우팅 방안에서, 시뮬레이션을 통해 min_used traffic 및 min_path의 입력 유형의 특성을 평가한다. Min_used traffic 입력을 이용한 heuristic 방식이 min_path 입력 방식에 비해 링크 절약 효율은 대체적으로 5% 정도 우수하지만, 각 노드의 SPT의 길이는 반대로 평균 약 0.2홉 정도 증가하고 있다. 그러나 이 두 방식은 random 입력 방식에 비해 링크 절약 효율과 SPT 경로 감소 면에서 상당히 우수하다. 또한 본 알고리즘 수행 중 링크 freezing 방법에 따라 링크 절약 효율이 최대 80% 정도 향상되므로 에너지 절감 효과가 크다. 따라서 본 논문에서 위임/수탁 라우터 기반의 heuristic 라우팅 방안을 적용하여 네트워크 품질 유지하면서 에너지를 절약 할 수 있음을 확인 한다.

• 정보기술과데이타베이스저널
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• 제6권2호
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• pp.71-86
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• 1999

The performance of relational database is measured by the number of disk accesses necessary to transfer data from disk to main memory. The paper proposes to vertically partition relations into fragments and to allow attribute replication to reduce the number of disk accesses. To reduce the computational time, heuristic search method using genetic algorithm is used. Genetic algorithm used employs a rank-based-sharing fitness function and elitism. Desirable parameters of genetic algorithm are obtained through experiments and used to find the solutions. Solutions of attribute replication and attribute non-replication problems are compared. Optimal solutions obtained by branch and bound method and by heuristic solutions(genetic algorithm) are also discussed. The solution method proposed is able to solve large-sized problems within acceptable time limit and shows solutions near the optimal value.