• 한국국방경영분석학회지
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• 제6권1호
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• pp.119-124
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• 1980

An efficient algorithm which can be employed in obtaining the minimal cut sets of a fault tree containing repeated events is introduced. A sample fault tree illustrates this algorithm. Efficiency of an algorithm is defined as the ratio of the number of minimal cut sets to the number of cut sets determined by the algorithm. An efficiency of the proposed algorithm is compared with those of two existing algorithms : Fussell and Vesely's algorithm and Bengiamin et al. 's algorithm. The proposed algorithm is shown to be more efficient than the existing two algorithms.

• 대한산업공학회지
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• 제20권3호
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• pp.3-14
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• 1994

In this study, two reliability computational algorithms which respectively utilize a factoring method are proposed for a system represented by reliability block diagram. First, vertex factoring algorithm is proposed. In this algorithm, a reliability block diagram is considered as a network graph with vertex reliabilities. Second algorithm is mainly concerned with conversion of a reliabilities block diagram into a network graph with edge reliabilities. In this algorithm, the independence of edges is preserved by eliminating replicated edges, and in computing the reliability of a converted network graph, existing edge factoring algorithm is applied. The efficiency of two algorithms are compared for example systems with respect to computing times. The results shows that the second algorithm is shown to be more efficient than the first algorithm.

• 품질경영학회지
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• 제30권4호
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• pp.68-77
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• 2002

EM algorithm has good convergence rate for numerical procedures which converges on very small step. In the case of proportion estimation in a mixed distribution which has very big incomplete data or of update of new data continuously, however, EM algorithm highly depends on a initial value with slow convergence ratio. There have been many studies to improve the convergence rate of EM algorithm in estimating the proportion parameter of a mixed data. Among them, dynamic EM algorithm by Hurray Jorgensen and Titterington algorithm by D. M. Titterington are proven to have better convergence rate than the standard EM algorithm, when a new data is continuously updated. In this paper we suggest dynamic EM algorithm and Titterington algorithm for the estimation of a mixed Poisson distribution and compare them in terms of convergence rate by using a simulation method.

• 한국항행학회논문지
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• 제19권2호
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• pp.116-122
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• 2015

지속적으로 증가하고 있는 항공수요에 따라, 공항운영 측면에서 이동지역 내 항공기 이동에 대한 효율성을 증대할 수 있는 방안의 중요성이 대두되고 있다. 본 논문은 공항 이동지역을 운항하는 항공기에게 최단경로를 적시에 제공하여 공항운영의 효율성을 증대시키기 위한 경로 탐색 알고리즘을 제시하고자 한다. 기존 문헌들에서 여러 알고리즘이 개발되었는데, 대표적으로 Dijkstra 알고리즘 $A^*$ 알고리즘이 있다. Dijkstra 알고리즘은 상대적으로 느린 연산속도로 인해 공항구조가 복합해질 경우 최단경로를 적시에 제공하기 어려울 수 있다는 단점이 있으며, $A^*$ 알고리즘은 최적성을 보장하지 못한다는 단점이 있다. 본 논문에서는 두 알고리즘을 병합하여, 각 알고리즘의 단점을 보완한 새로운 Hybrid $A^*$ 알고리즘을 제시하였다. 성능분석 결과, Hybrid $A^*$ 알고리즘은 경로탐색에 있어 빠른 연산속도와 최적성이 개선됨을 확인하였다.

• 한국정보과학회논문지:소프트웨어및응용
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• 제32권7호
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• pp.674-682
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• 2005

본 논문에서는 다중분광 영상의 분류를 위하여 퍼지 G-K(Gustafson- Kessel) 알고리즘과 PCM 알고리즘을 융합한 분류방법을 제안하였다. 제안된 방법은 학습데이타를 이용하여 퍼지 G-K 알고리즘을 수행한 후 그 결과를 이용하여 PCM 알고리즘을 수행한다 PCM 알고리즘과 퍼지 G-K 알고리즘 분류결과를 비교하여 그 결과가 일치하면 해당 항목으로 분류항목을 결정한다. 일치하지 않는 화소는 PCM 알고리즘의 평균내부거리 안쪽에 있는 화소들을 새로운 학습데이타로 하여 베이시안 최대우도 분류를 수행하여 분류항목을 결정한다. 평균내부거리 안쪽에 있는 화소 데이타는 정규분포형태를 보여준다. 다차원 다중분광 영상인 IKONOS와 LANDSAT TM 위성영상을 이용하여 제안된 알고리즘의 효율성을 검증한 결과 퍼지 G-K 알고리즘과 PCM 알고리즘 그리고 전통적인 분류 방법인 최대우도 분류 알고리즘보다 전체 정확도가 더 높은 결과를 얻을 수 있었다

• Journal of Communications and Networks
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• 제8권1호
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• pp.59-69
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• 2006

Bluetooth is reputed as a wireless networking technology supplying ad-hoc networks between digital devices. In particular, Bluetooth scatternet is an essential part of dynamic ad-hoc networks. Yet, there have not been sufficient researches performed on scatternet environment. This paper proposes a scatternet reformation algorithm for ad-hoc networks for instances where some nodes enter or leave the scatternet. The proposed algorithm is a general algorithm that can be applied to many types of Bluetooth scatternet regardless of the topology. The proposed algorithm is made for two reformation cases, i.e., nodes leaving and nodes entering. For the reformation when nodes leave a scatternet, the recovery node vector (RNV) algorithm is proposed. It has short reformation setup delay because the process involves a single page process (not including inquiry process). For the reformation when nodes enter a scatternet, the entry node algorithm is proposed. This is a simple and easily implementable algorithm. In this paper, real hardware experiments are carried out to evaluate the algorithm's performance where the reformation setup delay, the reformation setup probability and the data transfer rate are measured. The proposed algorithm has shown improvement in the reformation setup delay and probability.

• 중환자간호학회지
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• 제7권1호
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• pp.1-10
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• 2014

Purpose: The purpose of this study was developing a nasogastric tube feeding algorithm to prevent aspiration pneumonia. Methods: The algorithm was developed through a methodological design. First, a pilot study was performed to determine the incidence of pneumonia. The second step was development of a preliminary algorithm through a literature review and collection of nurse opinions. The third step was to establish content validity using a panel of 12 experts. The fourth step was revision of the algorithm. Next, 20 intensive care unit nurses applied the revised algorithm for six months to their actual treatment, and the practical feasibility was verified after that. Results: In the patients for whom this algorithm was applied, no cases of pneumonia occurred. The algorithm that was developed by the present author was suitable for clinical application. Conclusion: The effect and practical feasibility of the algorithm was tested with a few patients in this study. The effect of this algorithm should be examined by applying it to more patients on an ongoing basis.

• 제어로봇시스템학회논문지
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• 제17권8호
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• pp.843-850
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• 2011

In this paper, an effective path generation algorithm for obstacle avoidance producing small amount of steering action as possible is proposed. The proposed path generation algorithm can reduce unnecessary steering because of the small lateral changes in generated waypoints when UGV (Unmanned Ground Vehicle) encounters obstacles during its waypoint navigation. To verify this, the proposed algorithm and $A^*$ algorithm are analyzed through the simulation. The proposed algorithm shows good performance in terms of lateral changes in the generated waypoint, steering changes of the vehicle while driving and execution speed of the algorithm. Especially, due to the fast execution speed of the algorithm, the obstacles that encounter suddenly in front of the vehicle within short range can be avoided. This algorithm consider the waypoint navigation only. Therefore, in certain situations, the algorithm may generate the wrong path. In this case, a general path generation algorithm like $A^*$ is used instead. However, these special cases happen very rare during the vehicle waypoint navigation, so the proposed algorithm can be applied to most of the waypoint navigation for the unmanned ground vehicle.

• 한국전자파학회논문지
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• 제13권2호
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• pp.130-135
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• 2002

이 논문에서 는 부호 알고리듬(Sign Algorithm)의 수렴성능을 향상시킨 새로운 Equalizer 알고리듬을 소개하였다. 이것은 입력 데이터를 재활용하여 필터계수를 다중 갱신하는 Data-Recycling 방식을 곱셈 계산이 적은 Sign 알고리듬에 적용하였다. Sign 알고리듬은 계산량이 적고 구현이 간단한 장점을 가지나 느린 수렴속도의 한계를 가지고 있다. 제안한 알고리듬은 Sign 알고리듬의 계산량이 적은 장점과 Data-Recycling LMS 알고리듬의 단순성과 빠른 수렴속도를 가지는 장점을 결합한 구조의 알고리듬이다. 컴퓨터 시뮬레이션에서 제안된 적응 등화 알고리듬은 LMS 알고리듬보다 2배 빠른 수렴 속도를 나타내었으며, 근사한 수렴성능에 조건에서 Data-Recycling LMS와 비교할 때 반으로 줄어든 곱셈 계산량을 보였다.

• 대한전기학회논문지:전력기술부문A
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• 제49권9호
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• pp.446-450
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• 2000

A conventional variable percentage current differential relaying algorithm for bus protection may misoperate for external faults with severe CT saturation and internal faults with high impedance. This paper proposes a percentage differential current relaying algorithm for bus protection combined with a compensating algorithm of secondary currents of CTs. Even though CTs are saturated and their secondary currents are severely distorted, the proposed relaying algorithm does not only misoperate for external faults with CT saturation but also detects the internal faults with high fault impedance. Thus, the method improves the sensitivity of the relays and does not require any counterplan for CT saturation.