• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.12
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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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• v.29 no.10
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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.

• Journal of the Korean Institute of Telematics and Electronics
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• v.5 no.4
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• pp.1-8
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• 1968

A TANT network is a three-level network composed solely of NAND gates having only true(i.e. uncomplemented) inputs. The paper presents a technique for finding for any given Boolean function a least-cost TANT network. The first step of the technique is to determine essential prime implicants(EPI) by Quine-McCluskey procedure or other methods and generate prime implicants(PI) hving the same head as any one of EPI by consensus operation. The second step is to select common factors among the usable tail factors. The selcetion phase is analogous to the use of C-C table. The last step is to minimize inputs by deleting the redundant PI. the technique permits hand solution of typical five-and six-variable problems.

• Journal of the Korea Society of Computer and Information
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• v.20 no.4
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• pp.95-102
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• 2015

This paper proposes a simple algorithm for circuit minimization. There are currently two effective heuristics for circuit minimization, namely manual Karnaugh maps and computable Quine-McCluskey algorithm. The latter, however, has a major defect: the runtime and memory required grow $3^n/n$ times for every increase in the number of variables n. The proposed algorithm, however, extracts the prime implicants (PI) that cover minterms of a given Boolean function by deriving an implicants table based on frequency. From a set of the extracted prime implicants, the algorithm then eliminates redundant PIs again based on frequency. The proposed algorithm is therefore capable of minimizing circuits polynomial time when faced with an increase in n. When applied to various 3-variable and 4-variable cases, it has proved to swiftly and accurately obtain the optimal solutions.

• Journal of the Korean Institute of Telematics and Electronics
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• v.4 no.4
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• pp.19-21
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• 1967

A technique is illustrated for the selection of basis rows from a cyclic prime implicant table. This technique is more systematic and effective than a trial and process, and the results of this technique agree well with the ones solved by Gimpel's Luccio's reduction technique.

• Proceedings of the KIEE Conference
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• 1991.07a
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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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• v.30 no.2
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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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• v.56 no.6
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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.

• Journal of the Korea Society of Computer and Information
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• v.19 no.3
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• pp.109-117
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• 2014

This paper revises the Quine-McCluskey Algorithm to circuit minimization problems. Quine-McCluskey method repeatedly finds the prime implicant and employs additional procedures such as trial-and-error, branch-and-bound, and Petrick's method as a means of circuit minimization. The proposed algorithm, on the contrary, produces an implicant chart beforehand to simplify the search for the prime implicant. In addition, it determines a set cover to streamline the search for $1^{st}$ and $2^{nd}$ essential prime implicants. When applied to 3-variable and 4-variable experimental data, the proposed algorithm has indeed proved to obtain the optimal solutions much more simply and accurately than the Quine-McCluskey method.

• 전기의세계
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• v.28 no.11
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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.