• 한국인터넷방송통신학회논문지
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• 제22권2호
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• pp.151-157
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• 2022

본 논문에서는 NFT 거래 시 거래비용과 처리시간의 증가 및 스마트 계약 실행 시 발생하는 거래 안정성 요구을 높이기 위한 방법으로 다양한 블록체인 합의알고리즘의 성능을 비교 분석하였다. 성능 비교를 위한 평가항목으로 네트워크 신뢰성, TPS, 합의알고리즘의 안정성의 세 가지 평가항목에 대하여 제시하였다. 각 평가항목에 대한 정형화된 식을 수립하기 위하여 연산식에 노드의 신뢰도와 스마트 계약 성공률 등을 변수로 고려하였으며 동일 조건하에 PoW와 Raft, PBFT 세 개 그룹의 합의알고리즘에 대하여 성능을 비교하고 분석하였다. 성능평가 결과 네트워크 신뢰도는 세 그룹의 성능이 유사하였으며 나머지 두 개의 평가항목의 경우 다른 합의알고리즘 대비 PBFT 합의알고리즘이 우수한 것으로 분석되었다. 본 연구의 성능평가 연산식과 결과를 통하여 PBFT 합의시 본 연구에서 제안한 처리 과정을 합의 과정에 반영하여 처리할 경우 네트워크 신뢰성을 보장하고 합의 알고리즘의 안정성과 경제적 효율성을 높일 수 있는 것으로 분석되었다.

• Journal of Electrical Engineering and Technology
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• 제10권3호
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• pp.1356-1362
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• 2015

The location of PV systems in distribution system has been increased as one of countermeasure for global environmental issues. As the operation efficiency of PV systems is getting decreased year by year due to the aging phenomenon and maintenance problems, the optimal algorithm for state diagnosis in PV systems is required in order to improve operation performance in PV systems. The existing output prediction algorithms considering various parameters and conditions of PV modules could have complicated calculation process and then their results may have a possibility of significant prediction error. To solve these problems, this paper proposes an optimal prediction algorithm of PV system by using least square methods of linear regression analysis. And also, this paper presents a performance evaluation algorithm in PV modules based on the proposed optimal prediction algorithm of PV system. The simulation results show that the proposed algorithm is a practical tool of the state diagnosis for performance improvement in PV systems.

• 대한산업공학회지
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• 제12권1호
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• pp.133-138
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• 1986

In this paper, we are modeling the problem of the reliability evaluation in the network with delay. The triconnected decomposition and factoring algorithm for the network reliability, known as the most efficient algorithm, does not work in this constrained problem. So, we propose some ideas that reduce the above constrained problem to the general network reliability problem. We also present an algorithm for the reliability evaluation in the network with delay based on these ideas.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2002년도 추계학술대회 논문집
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• pp.40-44
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• 2002

선박 설계시 최적화에 있어 종래에는 Random search Parametric study, Hook&Jeeves Method등이 사용되어져 왔으나 1960년대 Genetic algorithm이 소개되고 꾸준히 발전함과 함께 선박 설계에서도 Genetic algorithm이 사용되기 시작하였다. 본 논문에서는 이러한 Genetic algorithm 중 Simple Genetic algorithm(SGA), Micro Genetic algorithm(MGA), Threshold Genetic algorithm(TGA), Hybrid Genetic algorithm(HGA)을 선박 설계에 적용하여 그 성능을 비교 검토해 보았다. MGA는 계산 부담을 줄이기 위해 작은 개체로 효율적인 탐색을 하며, TGA는 local optimum에서 쉽게 벗어나게 할 수 있는 특징이 있다. HGA는 Hook&Jeeves Method를 Genetic algorithm과 병합되어 있다. 이를 바탕으로 본 논문에서 망간단괴 수송선의 경제성을 평가한다. 평가 방법은 연간 300만톤을 생산한다고 가정하여 연간 운송 용적을 동호제약으로 해서 최적화를 한 뒤, 이를 이용하여 몇가지 Case로 나누어서 초기 자본, 연간 비용, 20년간 총 비용을 계산하여 가장 경제적인 선박을 선택한다.

• 융합경영연구
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• 제10권5호
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• pp.1-6
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• 2022

Purpose: To overcome the question that depends too much on expert's subjective judgment in traditional risk identification, this paper structure the multilevel generalized fuzzy comprehensive evaluation mathematics model of the risk identification of project, to research the risk identification of the project. Research design, data and methodology: This paper constructs the multilevel generalized fuzzy comprehensive evaluation mathematics model. Through iterative algorithm of AHP analysis, make sure the important degree of the sub project in risk analysis, then combine expert's subjective judgment with objective quantitative analysis, and distinguish the risk through identification models. Meanwhile, the concrete method of multilevel generalized fuzzy comprehensive evaluation is probed. Using the index weights to analyse project risks is discussed in detail. Results: The improved fuzzy comprehensive evaluation algorithm is proposed in the paper, at first the method of fuzzy sets core is used to optimize the fuzzy relation matrix. It improves the capability of the algorithm. Then, the method of entropy weight is used to establish weight vectors. This makes the computation process fair and open. And thereby, the uncertainty of the evaluation result brought by the subjectivity can be avoided effectively and the evaluation result becomes more objective and more reasonable. Conclusions: In this paper, we use an improved fuzzy comprehensive evaluation method to evaluate a railroad engineering project risk. It can give a more reliable result for a reference of decision making.

• 한국멀티미디어학회논문지
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• 제7권2호
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• pp.156-163
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• 2004

본 논문에서는 적응적 얼굴영역 검출과 얼굴 특징자 평가함수를 사용한 실시간 얼굴인식 알고리즘을 제안하였다. 제안한 알고리즘은 명암도 정보와 타원마스킹 기법뿐만 아니라 인종별 얼굴피부색을 사용하여 정확한 얼굴영역을 적응적으로 검출 가능하다. 또한 제안한 알고리즘은 얼굴 특징자 및 얼굴특징자간 기하학적 평가함수를 사용하여 얼굴 인식 효율을 개선하였다. 제안한 알고리즘은 생체인증 및 보안 시스템 분야에 사용 가능하다. 실험에서는 제안한 방법의 우수성을 입증하기 위해 실 영상을 사용하였으며 실험 결과 기존의 방법보다 얼굴 영역 검출뿐만 아니라 얼굴인식 성능을 개선하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 D
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• pp.3037-3039
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• 2005

The AIS(Automatic Identification System) transmits the position of ships and other information to prevent accidents which could occur in the sea. It has to be developed SOTDMA(Self-Organized Time Division Multiple Access) Algorithm which is important on wireless communication method for the AIS because It is based on ITU(International Telecommunication Union) M.1371-1 of the international standard therefore, we need to develop a performance evaluation simulator efficiently to develop and analyze SOTDMA Algorithm. this paper shows the method of designing it. Real ships access The VHF maritime mobile band but in this performance evaluation simulator several ship objects access the shared memory. Real ships are designed as the object and the wireless communication channel is designed as the shared memory. The ships apply for real virtual data which got from assistance hardware and The SOTDMA Algorithm driving state verifies the performance evaluation simulator by IEC(International Electrotechnical commission) 61993-2. After verifying results the performance evaluation simulator is correctly satisfied with IEC 61993-2. So we expect that it helps not only the AIS technology developed but also verify new SOTDMA Algorithm

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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• pp.478-480
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• 2005

The AIS(Automatic Identification System) transmits the position of ships and other information to prevent accidents which could occur in the sea. It has to be developed SOTDMA(Self-Organized Time Division Multiple Access) Algorithm which is important on wireless communication method for the AIS because It is based on ITU(International Telecommunication Union) M.1371-1 of the international standard therefore, we need to develop a performance evaluation simulator efficiently to develop and analyze SOTDMA Algorithm. This paper shows the method of designing it. Real ships access The VHF maritime mobile band but in this performance evaluation simulator several ship objects access the shared memory. Real ships are designed as the object and the wireless communication channel is designed as the shared memory. The ships apply for real virtual data which got from assistance hardware and The SOTDMA Algorithm driving state verifies the performance evaluation simulator by IEC(International Electrotechnical commission) 61993-2. After verifying results the performance evaluation simulator is correctly satisfied with IEC 61993-2. So we expect that it helps not only the AIS technology developed but also verify new SOTDMA Algorithm.

• International journal of advanced smart convergence
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• 제8권3호
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• pp.46-53
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• 2019

When a partitioned structure is derived from a data set using a clustering algorithm, it is not unusual to have a different set of outcomes when it runs with a different order of data. This problem is known as the order bias problem. Many algorithms in machine learning fields try to achieve optimized result from available training and test data. Optimization is determined by an evaluation function which has also a tendency toward a certain goal. It is inevitable to have a tendency in the evaluation function both for efficiency and for consistency in the result. But its preference for a specific goal in the evaluation function may sometimes lead to unfavorable consequences in the final result of the clustering. To overcome this bias problems, the first clustering process proceeds to construct an initial partition. The initial partition is expected to imply the possible range in the number of final clusters. We apply the data centric sorting to the data objects in the clusters of the partition to rearrange them in a new order. The same clustering procedure is reapplied to the newly arranged data set to build a new partition. We have developed an algorithm that reduces bias effect resulting from how data is fed into the algorithm. Experiment results have been presented to show that the algorithm helps minimize the order bias effects. We have also shown that the current evaluation measure used for the clustering algorithm is biased toward favoring a smaller number of clusters and a larger size of clusters as a result.

• 한국응용과학기술학회지
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• 제37권6호
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• pp.1507-1516
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• 2020

본 연구는 도로 노면결빙 판정 알고리즘을 적용하여 도로결빙 구간에 대한 시나리오를 분석하였다. 도로결빙 알고리즘 적용을 위해서, 도로 결빙에 대한 영향인자를 검토하고, 분석을 위해서 목감IC, 정릉터널, 성산대교, 염창교 등 4지점의 관측자료를 활용하였다. 관측소는 모두 고속화도로에 설치되어 있으며, 도로 결빙 특성 분석을 위하여 분류하였다. 도로 결빙 판정 알고리즘의 노면온도-노점온도 차가 3℃ 이하일 때 도로결빙 발생 구간을 확인하고 결빙 구간의 노면상태와 수막두께 변화를 통해 도로 결빙 판정을 도출하였다.