• 대한전기학회논문지
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• 제39권12호
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• pp.1288-1295
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• 1990

In this paper, we propose a parallel processing model for the efficient selection of Prime Implicants of Logic Functions. This model consists of simple parallel processing nodes, connections between them, Max Net (a part of Hamming Net) and quasi essential Prime Implicant selection standard in simplified cost form. Through these, this model selects essential Prime Implicants in a certain period of time regardless of the number of given Prime Implicants and minterms and also selects quasi essential Prime Implicants in short time.

• 전기의세계
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• 제29권10호
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• pp.678-688
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• 1980

This paper is concerned with the computer design of the multiple-output switching functions by using the improved MASK method in order to obtain the paramount prime implicants (prime implicants of the multiple-output switching function) and new algorithm to design the optimal logic network. All the given minterms for each function are considered as minterms of one switching function to simplify the desigh procedures. And then the improved MASK method whose memory requirement and time consuming are much less than any existing known method is applied to identify the paramount prime implicants. In selecting the irredundant paramount prime implicants, new cost criteria are generated. This design technuque is suitable both for solving a problem by hand or programming it on a digital computer.

• 대한전자공학회논문지
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• 제5권4호
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• pp.1-8
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• 1968

TANT회로라함은 진입력만을 NAND게이트만으로 구성되는 3단회로를 말한다. 본논문에서는 임의의 Boole함수에 대한 최소수게이트의 TANT회로를 발견하는 방법을 제시한 것이다. 합성절차의 첫 단계는 Quine-McCluskey의 절차 또는 기타방법에 의하여 essential prime implicants(EPI)를 정하고 채　두년산법을 적용하여 EPI와 동일한 두부를 갖는 prime implicants(PI)를 유도하는 것이다. 두째 단계로 동일한 두부를 갖는 EPI 및 PI를 통합하고 유용한 미부요소를 발생시키는 것이다. 그 다음에 이들 미부요소중에서 공통요소를 선정하는데 이 단계는 C-C표를 이용하는 것과 상통한 점이 있다. 마지막 단계로 용장한 PI를 삭제함으로써 입력수를 줄이는 것이다. 이 방법에 의하면 입력수가 5 및 6의 경우에는 수동적으로 용이하게 해를 얻을 수 있다.

• 한국컴퓨터정보학회논문지
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• 제20권4호
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• pp.95-102
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• 2015

본 논문은 회로 최소화 문제를 간단하게 풀 수 있는 알고리즘을 제안하였다. 회로 최소화 문제는 수기식 방법인 카르노 맵과 전산화가 가능한 휴리스틱 방법인 Quine-McCluskey 알고리즘이 있다. 그러나 Quine-McCluskey 알고리즘은 변수 개수 n이 증가하면 $3^n/n$의 메모리와 수행횟수가 요구되는 단점을 갖고 있다. 제안된 방법은 빈도수에 기반하여 내포 항 표를 이용하여 주어진 부울 함수의 최소 항을 포함하는 주 내포 항을 빠르게 추출하는 방법을 적용하였다. 추출된 주 내포 항들 중에서 중복 선택된 여분의 주 내포 항을 빈도수를 적용하여 제거하는 방법을 제안하였다. 제안된 알고리즘은 비록 변수 개수 n이 증가하여도 다항시간으로 회로를 최소화시킬 수 있는 해를 구할수 있는 장점을 갖고 있다. 제안된 알고리즘을 3-변수와 4-변수의 다양한 사례들에 적용한 결과 해를 빠르고 정확하게 구할 수 있었다.

• 대한전자공학회논문지
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• 제4권4호
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• pp.19-21
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• 1967

Cyclic prime implicant table에서 basis row를 선정하는 방법을 제시하였다. 이 방법은 존래의 시행착오법에 비하면 훨씬 통계적이고 유효하고 또한 이 방법에 의한 결과는 Gimpel이나 Luccio의 방법에 의한 결과와 잘 부합한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 하계학술대회 논문집
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• pp.341-344
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• 1991

Rules in expert system have meaning of assigning never-happen-minterms. Overall logical relations of variables can be achived by making all prime implicants of never-happen-minterms. From prime implicants, two tables, which are necessary in the process of inference, are constructed. There are two inferencing modes. One excutes inference only one variable which the user is interested in, and the other excutes inference all variables simultaneously. Outputs of inference have not only 'true' or 'false' but also 'unknown' which is different from conventional expert system. In this paper, an efficient approach is presented, which can check logical inconsistency in knowledge base and contradiction between input facts and rules. The methods in the paper may be available in the field of diagnosis and alarm processing.

• 전기의세계
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• 제30권2호
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• pp.101-111
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• 1981

This paper describes two methods which generate all the prime implicants (PI's) quickly by using the directions of adjacency tavle (DA-table) that gives the knowledge of adjacency relations among the given minterms. One is a graphical method that enables us to generate PI's by hand, the other is a checking method that determines the existance of PI's quickly when it is programmed on a digital computer. And a fast minimization algorithm will be shown in this paper that can be implemented with reduced computational effort by selecting essential prime implicants (EPI's) first of all and using the concept of the integration of the PI identification and selection procedure. The procedure, proposed in this paper, has all the advantage of Karnaugh mapping, so the procedure is simple and easy.

• Nuclear Engineering and Technology
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• 제56권6호
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• pp.2092-2098
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• 2024

Probabilistic safety assessment (PSA) plays a critical role in ensuring the safe operation of nuclear power plants. In PSA, event trees are developed to identify accident sequences that could lead to core damage. These event trees are then transformed into a core-damage fault tree, wherein the accident sequences are represented by usual and complemented logic gates representing failed and successful operations of safety systems, respectively. The core damage frequency (CDF) is estimated by calculating the minimal cut sets (MCSs) of the core-damage fault tree. Delete-term approximation (DTA) is commonly employed to approximately solve MCSs representing accident sequence logics from noncoherent core-damage fault trees. However, DTA can lead to an overestimation of CDF, particularly when fault trees contain many nonrare events. To address this issue, the present study introduces a new zero-suppressed ternary decision diagram (ZTDD) algorithm that averts the CDF overestimation caused by DTA. This ZTDD algorithm can optionally calculate MCSs with DTA or prime implicants (PIs) without any approximation from the core-damage fault tree. By calculating PIs, accurate CDF can be calculated. The present study provides a comprehensive explanation of the ZTDD structure, formula of the ZTDD algorithm, ZTDD minimization, probability calculation from ZTDD, strength of the ZTDD algorithm, and ZTDD application results. Results reveal that the ZTDD algorithm is a powerful tool that can quickly and accurately calculate CDF and drastically improve the safety of nuclear power plants.

• 한국컴퓨터정보학회논문지
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• 제19권3호
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• pp.109-117
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• 2014

본 논문은 회로 최소화 문제에 대한 Quine-McCluskey 법을 개선한 알고리즘을 제안하였다. Quine-McCluskey 법은 주 내포 항을 반복적인 방법으로 찾고, 회로 최소화 방법으로 시행착오법, 분기한정법 또는 Petrick 법을 적용한다. 반면에 제안된 알고리즘은 사전에 항표를 생성하여 주 내포 항을 간단히 찾는 방법을 제안하였으며, 집합피복을 결정하는 방법을 적용하여 1차와 2차 필수 주 내포 항을 간단히 찾는 방법을 제안하였다. 3-변수와 4-변수 실험 데이터에 적용한 결과 제안된 알고리즘이 Quine-McCluskey 법에 비해 보다 간단하면서도 정확히 해를 구할 수 있었다.

• 전기의세계
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• 제28권11호
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• pp.37-44
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• 1979

This paper deals with the computer program of finding the minimal sum-of-products for a switching function by using the MASK method derived from the characteristics of the Boolean algebra. The approach differs from the previous procedures in that all the prime implicants are determined only by the bit operation and the minimal sum-of-products are obtained by the modified Petrick method in this work. The important features are the relatively small amount of the run time and the less memory capacity to solve a problem, as compared to the previous computer programs.