• Journal of the Korean Institute of Telematics and Electronics B
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• v.32B no.6
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• pp.862-867
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• 1995

In this paper a method to perform Exclusive-OR operation between two tabular type Boolean expressions is presented. The proposed method allows to solve the switching equations and the simultaneous equations in a rather direct manner, compared with Unger's method.

• Journal of the Korean Society for information Management
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• v.13 no.1
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• pp.173-185
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• 1996

In this paper, we propose four optimizing methods for effectively processing queries in the Booleam information retrieval system ; (i) the short-circuit evaluation scheme used for optimizing logical expressions in programming lan-guages is applied to Boolean queries.(II) use the difference of the number of index word frequencies appearing in the related documents. (IIi) reduce the number of operators in the queries by applying the distribution law in the set theory. (iv) evaluate only once for the repeated expressions in the query. These methods have been implemented and tested in KRISTAL-II system on the UNIX workstation environment.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.3
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• pp.137-144
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• 1990

We describe how single layer perceptrons and new nonsymmetry feedback type neural networks can be implemented by VLSI CMOS technology. The network described provides a flexible tool for evaluation of boolean expressions and arithmetic equations. About 50 CMOS VLSI chips with an architecture based on two neural networks have been designed and me being fabricated by 2-micrometer double metal design rules. These chips have been developed to study the potential of neural network models for the use in character recognition and for a neural compute.

• Journal of Korea Society of Industrial Information Systems
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• v.18 no.1
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• pp.25-35
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• 2013

Automatically deriving only individual don't-care minterms that can effectively reduce a Boolean logic expressions are being investigated. Don't-care conditions play an important role in optimizing logic design. The type of unknown don't-care minterms that can always reduce the number of product terms in Boolean expression are referred as single hypothetical don't-care (S-HDC) minterms. This paper describes the Quasi Quine-McCluskey method that systematically derives S-HDC minterms. For the most part, this method is similar to the original Quine-McCluskey method in deriving the prime implicants. However, the Quasi Quine-McCluskey method further derives S-HDC minterms by applying so-called a combinatorial comparison operation. Upon completion of the procedure, the designer can review generated S-HDC minterms to test its appropriateness for a particular application.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.8
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• pp.361-366
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• 2017

For two given logical expressions and, when expression contains the same part of the logical expression as expression, substituting for that part of expression is called a substituted logic expression. If a substituted relation is established between the logical expressions, there is an advantage in that the number of literals used in the whole logical expression can be greatly reduced. However, if the substituted relation is not established, there is no simplification effect obtained from the substituted expression. Previous methods proposed a way to find substituted relations between logical expressions for the given logical expressions themselves, and to calculate substituted expressions if only substitution is possible. In this paper, a new method for performing substitution with addition and revision of logic terms is proposed in order to perform substitution, even though there is no substituted relation between two logic expressions. The proposed method is efficiently implemented using a matrix that finds terms to be added. Then, by covering the matrix that has added terms, substituted logic expressions are found. Experiment results show that the proposed method for several benchmark circuits can reduce the number of literals, compared to existing synthesis tools.

• The Journal of Korean Association of Computer Education
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• v.20 no.4
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• pp.77-84
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• 2017

This paper proposes a tool that can be used as a logical expression simplification tool that can be used for deepening learning of logic circuits and further utilized as a design automation tool for optimizing semiconductor parts. The simplification method of logical expressions proposed in this paper is to find common subexpressions existing in various logical expressions and reduce the repetitive use. Finally, the goal is to minimize the number of literals used in all logical expressions. These previous studies failed to produce a common subexpression embedded in the logical expressions because they only use division principle. The proposed method uses cubes with a Hamming distance of 3 to find the common subexpression embedded between logical expressions. Experiments using benchmark circuits show that the proposed method reduces the number of literals by as much as 47% when comparing simplifications with other methods.

• Journal of the Korean Institute of Telematics and Electronics
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• v.15 no.6
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• pp.43-47
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• 1978

This paper presents a technique for symbolic reliability analysis of a general communication network. All simple paths are determined, then they are easily modified to be mutually disjoint by the specific Boolean expressions. A computer program for Binding all of the simple paths between two terminals is also developed. The examples are given to illustrate the technique.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2000.04a
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• pp.385-388
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• 2000

The computation of a terminal-pair reliability is started with a Boolean sum of products expression corresponding to simple paths of the pair of nodes. This expression is then transformed into another equivalent expression to be a Sum of Disjoint Products form. The terminal reliability can then be obtained in a straightforward manner from the Sum of Disjoint Products form. In this paper, we proposed an efficient method to obtain reliability expressions for calculating multiple K terminal-pairs reliability between terminal-pairs of nodes of computers of complex networks. Actual programming results show that the new method is superior with regard to computational efficiency, especially for computing the reliability of multiple terminals.

• Journal of the Korean Society for information Management
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• v.21 no.2
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• pp.235-248
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• 2004

For the users of information retrieval systems, natural language query is the more ideal interface, compared with keyword and boolean expressions. This paper proposes a retrieval technique with expanded keyword from syntactically-analyzed structures of natural language query as user input. Through the steps combining or splitting the compound nouns based on syntactic tree traversal of the query, and expanding the other-formed or shorten-formed into multiple keyword, it can enhance the precision and correctness of the retrieval system.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.2
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• pp.216-221
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• 2004

This paper describes an optimal synthesis method of binary neural network for pattern recognition. Our objective is to minimize the number of connections and the number of neurons in hidden layer by using a Newly Expanded and Truncated Learning Algorithm (NETLA) for the multilayered neural networks. The synthesis method in NETLA uses the Expanded Sum of Product (ESP) of the boolean expressions and is based on the multilayer perceptron. It has an ability to optimize a given binary neural network in the binary space without any iterative learning as the conventional Error Back Propagation (EBP) algorithm. Furthermore, NETLA can reduce the number of the required neurons in hidden layer and the number of connections. Therefore, this learning algorithm can speed up training for the pattern recognition problems. The superiority of NETLA to other learning algorithms is demonstrated by an practical application to the approximation problem of a circular region.