• 한국공작기계학회논문집
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• 제16권6호
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• pp.181-186
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• 2007

UBM (Under Bump Metallurgy) of flip chip assemblies consists of several layers such as the solder wetting, the diffusion barrier, and the adhesion layers. In addition, IMC layers are formed between the solder wetting layers (e.g. Cu, Ni) and the solder. The primary failure mechanism of the solder joints in flip chips is widely known as the fatigue failure caused by thermal fatigues or electromigration damages. Sometimes, the premature brittle failure occurs in the IMC layers. However, these phenomena have thus far been viewed from only experimental investigations. In this sense, this paper presents a method for solid modeling of IMC layers in flip chip assemblies, thus providing a pre-processing tool for finite element analysis to simulate the IMC failure mechanism. The proposed modeling method is CSG-based and can also be applied to the modeling of UBM structure in flip chip assemblies. This is done by performing Boolean operations according to the actual sequences of fabrication processes

• 한국신뢰성학회지:신뢰성응용연구
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• 제6권2호
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• pp.187-194
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• 2006

In this paper, We presented the algorithm for estimating a reliability between nodes in wireless communication network such as RBN and MANET To estimate the reliability between nodes, we first modeled RNB and MANET as probability graph. Branches of the graph are always reliable and the probability of node failure is independent. After all possible simple path which can be established between two nodes are examined, we perform sharp arithmetic to remove repetition event between two nodes. Using probability for each variable of the minimized Boolean equation, we present the reliability formula.

• 한국신뢰성학회지:신뢰성응용연구
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• 제6권4호
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• pp.297-306
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• 2006

In this paper, We presented the algorithm for estimating a reliability between nodes in wireless distributed sensor networks (DSN). To estimate the reliability between nodes, we first modeled DSN as probability graph. Links of the graph are always reliable and the probability of node failure is independent. After all possible simple path which can be established between two nodes are examined, we perform sharp operation to remove repetition event between two nodes. Using probability for each variable of the minimized Boolean equation, we present the reliability formula.

• 한국신뢰성학회지:신뢰성응용연구
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• 제8권4호
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• pp.181-192
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• 2008

In this paper, we proposed effective algorithm that do Availability of communication network account using total probability formula. Use path tracing method about PSTN linked with MSC in WCDMA considering occasion that do not consider mobility of terminal and Availability did account. First, express minimum path series gathering by structure function after network that do modeling by stochastic graph for communication network saves all minimal path sets between particular two abutments and we gain Availability value in angular variable after express structure function by Boolean operation form and Availability between two abutments did account.

• 한국컴퓨터정보학회논문지
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• 제20권11호
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• pp.25-30
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• 2015

The enormous increase of data with the development of the information technology make internet users to be hard to find suitable information tailored to their needs. In the face of changing environment, the information filtering method, which provide sorted-out information to users, is becoming important. The data on the internet exists as various type. However, similarity calculation algorithm frequently used in existing collaborative filtering method is tend to be suitable to the numeric data. In addition, in the case of the categorical data, it shows the extreme similarity like Boolean Algebra. In this paper, We get the similarity in SNS user's information which consist of the mixed data using the Gower's similarity coefficient. And we suggest a method that is softer than radical expression such as 0 or 1 in categorical data. The clustering method using this algorithm can be utilized in SNS or various recommendation system.

• 한국컴퓨터그래픽스학회논문지
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• 제3권2호
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• pp.77-84
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• 1997

3차원 물체를 표현하는 솔리드 모델링 기법으로 Constructive Solid Geometry(CSG)와 경계표현 (Boundary Representation: BRep)이 널리 쓰이고 있다. 현대의 솔리드 모델링 시스템들은 대개 이 두 기법을 모두 지원하고 있으며, CSG와 BRep간 상호 변환은 매우 중요한 문제이다. 하지만, BRep에서 CSG로의 변환은 아직 완전히 해결되지 않은 과제이다. 이 논문은 BRep을 CSG의 특수한 형태인 Destructive Solid Geometry(DSG)로 변환하는 3차원 기하 추론 알고리즘을 소개한다. BRep에서 DSG를 만들어내는 알고리즘은 CAD와 CAM을 통합시키는 특정 형상 인식 분야에 직접 응용될 수 있다.

• 한국문헌정보학회지
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• 제17권
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• pp.299-337
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• 1989

In this study, an Intermediary System for Searches has been designed and implemented. This System has some key functions as follows: First, in each stage of a search process, the information related to a definite term could be provided. Second, through displaying semantic categories for terms this system 'helps a searcher in modifying search terms when he fails to retrieve. Third, being consulted, this system could assist a searcher in making a Boolean search statement in terms of search specificity Fourth, to make a final search statement, a searcher could have several rounds of search cycles through displaying related terms, semantic categories, and frames.

• 한국문헌정보학회지
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• 제21권
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• pp.225-248
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• 1991

The paper suggests newly conceptualized information retrieval system on the notion of citation analysis. The paper also criticizes the traditional information retrieval techniques using Boolean logic. The underlying assumption of this paper is that any pair of papers cited by one paper could be strongly related each other in meaning (Co-citation Analysis). And also any two papers to share same references could be similar each other (Bibliographic Coupling), By using graph algorithm, the networks of two kinds of the papers (the citing group, the cited group) is made in the fields of the genetics and the information and library science. The results say that the maps or networks for cited and citing groups can be useful when applied to the paper set made by the broad searching by subjects or keywords.

• 한국정보통신학회논문지
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• 제7권7호
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• pp.1556-1562
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• 2003

본 연구에서는 SA 여파기로 불리는 ETBF의 새로운 다진 영역 표현을 제시하고 이 표현이 ETBF의 모든 영역을 포함한다는 사실을 밝혔다. SA여파기는 다단 여파기의 구조를 가진다. 첫째단(first stage)은 최대, 최소, exclusive-OR와 같은 비선형 연산으로 이루어지며 두 번째 단은 첫째단 출력들의 가중 평균으로 주어진다. 이 구조는 SAM 여파기와 같이 첫째단 여파기 윈도우의 최대수를 제한하는 방식이 가능하여 매우 유연한 구조를 갖지만, SAM 여파기와는 달리 ETBF의 부분군만을 표현하지 않고 ETBF의 전 영역을 표현할 수 있는 장점이 있다.

• Journal of information and communication convergence engineering
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• 제5권1호
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• pp.59-63
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• 2007

In this paper, a CLB-based CPLD low-power technology mapping algorithm considered a Trade-off is proposed. To perform low-power technology mapping for CPLDs, a given Boolean network has to be represented in a DAG. The proposed algorithm consists of three steps. In the first step, TD(Transition Density) calculation has to be performed. Total power consumption is obtained by calculating the switching activity of each node in a DAG. In the second step, the feasible clusters are generated by considering the following conditions: the number of inputs and outputs, the number of OR terms for CLB within a CPLD. The common node cluster merging method, the node separation method, and the node duplication method are used to produce the feasible clusters. In the final step, low-power technology mapping based on the CLBs packs the feasible clusters. The proposed algorithm is examined using SIS benchmarks. When the number of OR terms is five, the experiment results show that power consumption is reduced by 30.73% compared with TEMPLA, and by 17.11 % compared with PLA mapping.