• 동의생리병리학회지
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• 제23권4호
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• pp.745-750
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• 2009

The goal of this study is to examine on reasoning and search for construction of diagnosis ontology as a knowledge base of diagnosis expert system in oriental medicine. Expert system is a field of artificial intelligence. It is a system to acquire information with diverse reasoning methods after putting expert's knowledge in computer systematically. A typical model of expert system consists of knowledge base and reasoning & explanatory structure offering conclusion with the knowledge. To apply ontology as knowledge base to expert system practically, consideration on reasoning and search should be together. Therefore, this study compared and examined reasoning, search with diagnosis process in oriental medicine. Reasoning is divided into Rule-based reasoning and Case-based reasoning. The former is divided into Forward chaining and Backward chaining. Because of characteristics of diagnosis, sometimes Forward chaining or backward chaining are required. Therefore, there are a lot of cases that Hybrid chaining is effective. Case-based reasoning is a method to settle a problem in the present by comparing with the past cases. Therefore, it is suitable to diagnosis fields with abundant cases. Search is sorted into Breadth-first search, Depth-first search and Best-first search, which have respectively merits and demerits. To construct diagnosis ontology to be applied to practical expert system, reasoning and search to reflect diagnosis process and characteristics should be considered.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2009년도 IWAIT
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• pp.460-465
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• 2009

This paper presents a new algorithm that includes a mechanism to avoid local solutions in a motion vector detection method that uses the steepest descent method. Two different implementations of the algorithm are demonstrated using two major search methods for tree structures, depth first search and breadth first search. Furthermore, it is shown that by avoiding local solutions, both of these implementations are able to obtain smaller prediction errors compared to conventional motion vector detection methods using the steepest descent method, and are able to perform motion vector detection within an arbitrary upper limit on the number of computations. The effects that differences in the search order have on the effectiveness of avoiding local solutions are also presented.

• 동아시아경상학회지
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• 제6권4호
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• pp.13-24
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• 2018

Purpose - This study investigates the moderation effect of internal factor, a firms size, on the external knowledge sourcing strategy and its effectiveness in generating radical innovation. We incorporate concepts of breadth and depth as two measures to gauge the degree of openness in firms external search Research design and methodology - The dependent variable in the regression model is the percentage of innovative sales and therefore, Tobit regression is employed for estimating significant factors affecting on the ratio of first-to-market by breadth and depth in external knowledge, internationalization, and size. Results - The results show that the external knowledge, in terms of both breadth and depth, has a positive relationship with radical innovation. However internationalization as external knowledge resources is not statistically accepted. Firm size has moderating effect on innovation negatively only in case of using external knowledge resources to a high degree. Conclusions - Firms obtain external information mostly from customers, competitors, and suppliers etc. empirical knowledge in terms of scope and intensity is an important contributor to innovation. And intensity use of external knowledge and information resources can work in favor of smaller firms rather than larger ones. Internationalization seems to have little effect on innovation but it requires further researches with clear criteria and more data.

• 한국컴퓨터산업학회논문지
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• 제4권12호
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• pp.1093-1102
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• 2003

The dynamic nature of the World Wide Web challenges Search engines to find relevant and recent pages. Obtaining important pages rapidly can be very useful when a crawler cannot visit the entire Web in a reasonable amount of time. In this paper we study way spiders that should visit the URLs in order to obtain more “important” pages first. We define and apply several metrics, ranking formula for improving crawling results. The comparison between our result and Breadth-first Search (BFS) method shows the efficiency of our experiment system.

• 한국컴퓨터정보학회논문지
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• 제9권3호
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• pp.71-77
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• 2004

게임을 하다보면 유닛들이 목표를 찾아 가야하는데 알고리즘에 따라 시간과 거리가 많이 차이 나게 된다. 본 논문에서는 깊이 우선 탐색과 너비 우선 탐색 그리고 거리 값을 주어 개선된 알고리즘과 A* 알고리즘의 각각을 비교하며 특징들을 기술하고 알고리즘을 논하였다. 또한 A* 알고리즘에서 실제로 추정값을 구하여 가장 개선된 값을 찾는다. 마지막으로 A* 알고리즘과 다른 알고리즘의 비교를 통하여 A* 알고리즘을 우수성을 입증하고 A* 알고리즘을 이용한 간단한 길찾기를 제안하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권4호
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• pp.1845-1865
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• 2019

Current Internet is designed by lots of service providers with different objects and policies which make the direct deployment of radically new architecture and protocols on Internet nearly impossible without reaching a consensus among almost all of them. Network virtualization is proposed to fend off this ossification of Internet architecture and add diversity to the future Internet. As an important part of network virtualization, virtual network embedding (VNE) problem has received more and more attention. In order to solve the problems of large embedding cost, low acceptance ratio (AR) and environmental adaptability in VNE algorithms, cognitive method is introduced to improve the adaptability to the changing environment and a cognitive virtual network embedding algorithm based on weighted relative entropy (WRE-CVNE) is proposed in this paper. At first, the weighted relative entropy (WRE) method is proposed to select the suitable substrate nodes and paths in VNE. In WRE method, the ranking indicators and their weighting coefficients are selected to calculate the node importance and path importance. It is the basic of the WRE-CVNE. In virtual node embedding stage, the WRE method and breadth first search (BFS) algorithm are both used, and the node proximity is introduced into substrate node ranking to achieve the joint topology awareness. Finally, in virtual link embedding stage, the CPU resource balance degree, bandwidth resource balance degree and path hop counts are taken into account. The path importance is calculated based on the WRE method and the suitable substrate path is selected to reduce the resource fragmentation. Simulation results show that the proposed algorithm can significantly improve AR and the long-term average revenue to cost ratio (LTAR/CR) by adjusting the weighting coefficients in VNE stage according to the network environment. We also analyze the impact of weighting coefficient on the performance of the WRE-CVNE. In addition, the adaptability of the WRE-CVNE is researched in three different scenarios and the effectiveness and efficiency of the WRE-CVNE are demonstrated.

• 한국컴퓨터정보학회논문지
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• 제22권6호
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• pp.49-55
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• 2017

Robots, games and life applications have been developed while computer areas are developed. Moreover, various applications have been utilized for various users including the early childhood. Recently, smart phones have been dramatically used by various users including early childhood. Many applications need to find a path from a starting point to destinations. For example, without using real maps, users can find the direct paths for the destinations in realtime. Specifically, path exploration in game programs is so important to have accurate results. Nowadays, with these techniques, diverse applications for educations of early childhood have been developed. To deal with the functions, necessity of efficient path search programs with high accuracy becomes much higher. In this paper, we design and develop a friendly maze program for early childhood based on a path searching algorithm. Basically, the path of lineal distance from a starting location to destination is considered. Moreover, weight values are calculated by considering heuristic weighted h(x). In our approach, A* algorithm searches the path considering weight values. Moreover, we utilize depth first search approach instead of breadth first search in order to reduce the search space. so it is proper to use A* algorithm in finding efficient paths although it is not optimized paths.

• 대한전기학회논문지
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• 제38권9호
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• pp.684-692
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• 1989

An expert system which is a part of artificial intelligence is developed for controlling violated voltages. Control equipments such as shunt capacitors, inductors, transformer tap changers and generator voltages are utilized. A breadth-first search method is used. A sensitivity tree is suggested to minimize the number of control devices. If the voltage condition program should be utilized to efficiently solve the problem. The expert system uses PROLOG and for the sub-program C language is used. This expert system, when applied to an 8 bus power system, shows satisfactory results.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2003년도 가을 학술발표논문집 Vol.30 No.2 (1)
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• pp.58-60
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• 2003

원숭이와 바나나 문제는 논리적 추론에 의한 문제 해결 과정을 설명하기 위해 사용되는 대표적 예제이다. 본 논문에서는 전통적인 접근 방식과는 달리, 이 문제를 그래프 탈색의 그것으로 이해한 후 DNA 컴퓨팅에 근거한 너비 우선 탐색(breadth-first search, BFS)을 통해 해들을 발견하고자 한다. 그 결과, 최적해 (optimal solution)를 포함한 최소 4개 이상의 다양한 해들이 실제 DNA 생화학 실험을 통해 확인되었다.

• 한국정보과학회논문지:데이타베이스
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• 제34권2호
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• pp.119-132
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• 2007

유사 서브 시퀀스 검색은 분자 생물학 분야에서 사용되는 매우 중요한 연산이다. 본 논문에서는 대규모 DNA 시퀀스 데이타베이스를 처리 대상으로 하여 효율성과 정확도를 보장하는 실용적인 유사 서브 시퀀스 검색 기법을 제안한다. 제안된 기법은 이진 트라이를 인덱스 구조로 채택하여 DNA 시퀀스로부터 추출한 일정 길이의 윈도우 서브 시퀀스를 인덱싱 대상으로 한다. 유사 서브 시퀀스 검색 알고리즘은 기본적으로 다이나믹 프로그래밍 기법에 근거하여 이진 트라이를 루트로부터 너비 우선(breadth-first)방식으로 운행하며, 경로 상에 존재하는 모든 유사 서브 시퀀스를 검색해 낸다. 그러나 질의 길이가 윈도우의 크기보다 큰 일반적인 경우에는 질의를 일정 길이의 서브 시퀀스로 분해하여 각 서브 시퀀스에 대하여 유사 서브 시퀀스 검색을 수행한 후, 후처리 과정에 의하여 정확도에 손상 없이 이들 결과를 결합하는 분할 질의 처리 방식을 채택한다. 제안된 기법의 우수성을 검증하기 위하여, 실험을 통한 성능 평가를 수행한다. 실험 결과에 의하면 제안된 인덱스 기법은 접미어 트리에 비하여 약 40%의 작은 저장 공간을 가지고도 약 4-17배의 검색 성능의 개선 효과를 나타낸다. 또한 분할 질의 처리 방식에 의한 유사 서브 시퀀스 검색 알고리즘은 질의 길이가 긴 경우에도 효율적으로 동작하여 Suffix와 Smith-Waterman 알고리즘에 비하여 각각 수배에서 수십배의 검색 성능의 개선 효과를 나타낸다.