• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.6
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• pp.910-920
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• 1990

This paper presents a method of constructing an Arithmetic Operation Unit Systems (A.O.U.S.) over Galois Field GF(2**m) for the purpose of the four arithmetical operation(addition, subtraction, multiplication and division between two elements in GF(2**mm). The proposed A.O.U.S. is constructed by following procedure. First of all, we obtained each four arithmetical operation algorithms for performing the four arithmetical operations using by mathematical properties over GF(2**m). Next, for the purpose of realizing the four arithmetical unit module (adder module, subtracter module, multiplier module and divider module), we constructed basic cells using the four arithmetical operation algorithms. Then, we realized the four Arithmetical Operation Unit Modules(A.O.U.M.) using basic cells and we constructd distributor modules for the purpose of merging A.O.U.M. with distributor modules. Finally, we constructed the A.O.U.S. over GF(2**m) by synthesizing A.O.U.M. with distributor modules. We prospect that we are able to construct an Arithmetic & Logical Operation Unit Systems (A.L.O.U.S.) if we will merge the proposed A.O.U.S. in this paper with Logical Operation Unit Systems (L.O.U.S.).

• Journal of the Korea Furniture Society
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• v.24 no.4
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• pp.379-388
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• 2013

In this study, the effect of various glass fiber (GF) contents in a shell layer and shell thickness changes on the flexural property of coextruded wood plastic composites (WPCs) in combination with three core systems (weak, moderate, and strong) was investigated. GF behaved as an effective reinforcement for the whole coextruded WPCs and GF alignments in the shell layer played an important role in determining the flexural property of the coextruded WPCs. At a given shell thickness, the flexural property of the whole coextruded WPCs was improved with the increase of GF content in shell. For core quality, when the core is weak, increase of GF content in shell led to improved flexural property of the whole composites and increase of shell thickness helped it. On the other hand, when the core is strong, the flexural property of the whole composites showed reduced features at low GF content in shell and increase of shell thickness aggravated it. This approach provides a method for optimizing performance of the coextruded WPCs with various combinations of core-shell structure and properties.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.1
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• pp.159-164
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• 1992

The present study was done to examine whether inoculated and established bacteria in the digestive tract of germ-free (GF) chickens affect growth performance, energy availability, nitrogen utilization and neutral detergent fibre (NDF) digestibility of the host bird fed a high-fibre diet. Gnotobiotic (GB) chicks were made from GF birds by co-inoculating with Ruminococcus albus, and Staphylococcus warneri, only the latter of which was established in the chicken gut. No difference was detected among conventional (CV), GF and GB birds in body weight gain, food intake or food efficiency from 7 to 21 d of age. The amount of nitrogen retained was larger in CV than in GF and GB chicks. DE and ME values of the diet and NDF digestibility were higher in CV birds than in GF and GB counterparts. It was concluded, therefore, that the established bacterium S. warneri did not give any beneficial effects on the host bird as judged by growth performance, energy availability, nitrogen utilization, and NDF digestibility.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.11C
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• pp.892-897
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• 2008

In this paper, a new architecture for digit-parallel/bit-serial GF$(2^m)$ multiplier with low latency is proposed. The proposed multiplier operates in polynomial basis of GF$(2^m)$ and produces multiplication results at a rate of one per D clock cycles, where D is the selected digit size. The digit-parallel/bit-serial multiplier is faster than bit-serial ones but with lower area complexity than bit-parallel ones. The most significant feature of the proposed architecture is that a trade-off between hardware complexity and delay time can be achieved.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.2A
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• pp.102-109
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• 2003

In this paper, the new multiplicative algorithm using standard basis over GF(2m) is proposed. The multiplicative process is simplified by data select method in proposed algorithm. After multiplicative operation, the terms of degree greater than m can be expressed as a polynomial of standard basis with degree less than m by irreducible polynomial. For circuit implementation of proposed algorithm, we design the circuit using multiplexer and show the example over GF(24). The proposed architectures are regular and simple extension for m. Also, the comparison result show that the proposed architecture is more simple than privious multipliers. Therefore, it well suited for VLSI realization and application other operation circuits.

• Journal of the Korea Society of Computer and Information
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• v.20 no.2
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• pp.1-10
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• 2015

In this paper, we propose a new multiplication algorithm for primitive polynomial with all 1 of coefficient in case that m is odd and even on finite fields $GF(3^m)$, and design the multiplier with parallel input-output module structure using the presented multiplication algorithm. The proposed multiplier is designed $(m+1)^2$ same basic cells. Since the basic cells have no a latch circuit, the multiplicative circuit is very simple and is short the delay time $T_A+T_X$ per cell unit. The proposed multiplier is easy to extend the circuit with large m having regularity and modularity by cell array, and is suitable to the implementation of VLSI circuit.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.14 no.3
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• pp.235-239
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• 1989

A multiplier is proposed for computing multiplication of two arbitrary elements in the finite fields GF($2^m$), and the operation process is described step by step. The modified type of the circuit which is constructed with m-stage feedgack shift register, m-1 flip-flop, m AND gate, and m-input XOR gate is presented by referring to the conventional shift-register multiplier. At the end of mth shift, the shift-register multiplier stores the product of two elements of GF($2^m$); however the proposed circuit in this paper requires m-1 clock times from first input to first output. This circuit is simpler than cellulra-array or systolic multiplier and moreover it is faster than systolic multiplier.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.1C
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• pp.21-27
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• 2009

We present an efficient exponentiation algorithm for a finite field $GF(2^n)$ determined by an optimal normal basis of type II using signed digit representation of the exponents. Our signed digit representation uses a non-adjacent form (NAF) for $GF(2^n)$. It is generally believed that a signed digit representation is hard to use when a normal basis is given because the inversion of a normal element requires quite a computational delay. However our result shows that a special normal basis, called an optimal normal basis (ONB) of type II, has a nice property which admits an effective exponentiation using signed digit representations of the exponents.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.8
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• pp.1774-1779
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• 2005

This paper propose the design method of the constructing the digital logic systems over galois fields using by the galois field decision diagram(GFDD) that is based on the graph theory. The proposed design method is as following. First of all, we discuss the mathematical properties of the galois fields and the basic properties of the graph theory. After we discuss the operational domain and the functional domain, we obtain the transformation matrixes, $\psi$GF(P)(1) and $\xi$GF(P)(1), in the case of one variable, that easily manipulate the relationship between two domains. And we extend above transformation matrixes to n-variable case, we obtain $\psi$GF(P)(1) and $\xi$GF(P)(1). We discuss the Reed-Muller expansion in order to obtain the digital switching functions of the P-valued single variable. And for the purpose of the extend above Reed-Muller expansion to more two variables, we describe the Kronecker product arithmetic operation.

• Journal of Communications and Networks
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• v.13 no.5
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• pp.494-498
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• 2011

Satellite digital multimedia broadcasting (S-DMB) systems use gap fillers (GFs) to provide wireless multimedia services to non-line-of-sight locations. GFs act as repeaters, and S-DMB systems require GF networks in order to guarantee mobile reception. Each GF covers a cell or sector. In order to provide contiguous coverage of an area comprising two or more cells or sectors, multiple GFs are needed. However, when multiple GFs are situated close to each other, interference is likely to occur. As a result, in this study, we have investigated system-level environments for planning the design of interference-free GF networks in S-DMB systems. Our investigations revealed that S-DMB services are unavailable because of quality deterioration caused by interference when the delay attributable to a GF and the satellite signals exceeds ${\pm}$256 chips and the distance between the GF and its reception terminal is greater than 4.6 km. On the basis of this analysis, we conducted a field test that confirmed that the above-mentioned time delay can be controlled in such a way as to ensure high quality S-DMB services.