• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.3
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• pp.627-633
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• 2013

An important problem in the transmission performance and efficiency is to find the values and the number of the cross-correlation function between two different maximal sequences. In this paper, we present the new maximal sequences which are obtained by the new decimations $d=\frac{2^{m-st-1}}{2^s-1}(2^n+2^{st+s+1}-2^{m+st+1}-1)$ from some maximal sequences. We will also find the values and the number of occurrences of each value of the cross-correlation function from the proposed decimations.

• Journal of the Korean Institute of Intelligent Systems
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• v.18 no.2
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• pp.272-277
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• 2008

Symmerge is a stable minimum storage merging algorithm that needs $O(m{\log}{\frac{n}{m}})$ element comparisons, where in and n are the sizes of the input sequences with $m{\leq}n$. Hence, according to the lower bound for merging, the algorithm is asymptotically optimal regarding the number of comparisons. The Symmerge algorithm is based on the standard recursive technique of "divide and conquer". The objective of this paper is to consider the relationship between m and n for the degenerated case where the recursion depth reaches m-1.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.1C
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• pp.9-14
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• 2009

In this paper, using the binary (N,M,L,1) low correlation zone(LCZ) sequence set with specific property, we propose the construction method of a quaternary LCZ sequence set with parameters (2N,2M,L,2). The binary LCZ sequence using this method must have period $N{\equiv}3$ mod 4, balance property, and specific correlation property. The proposed method is modified from the construction method of binary LCZ sequence set by using binary LCZ sequence with specific condition proposed by Kim, Jang, No, and Chung[4].

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.8C
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• pp.735-741
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• 2005

In this paper, we derived the autocorrelation distributions, i.e., the values and the number of occurrences of each value of the autocorrelation function of Sidel'nikov sequences. The frequency of each autocorrelation value of an M-ary Sidel'nikov sequence is expressed in terms of the cyclotomic numbers of order M. It is also pointed out that the total number of distinct autocorrelation values is dependent not oかy on M but also on the sequence, but always less than or equal to ($\frac{M}{2}$)+1.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.15 no.4
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• pp.145-151
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• 2005

Color enhancement of African rubies with dark red was carried out by the heat treatment and the hydrothermal treatment method respectively. The heat treatment method brought about an adverse effect causing the color to be deteriorated. However, the hydrothermal treatment method enhanced its color and clarity. The hydrothermal treatment conditions for color enhancement of them were as follows: solvent: 0.9M $Na_2CO_3-1M\;K_2CO_3$, temperature: $450^{\circ}C$, duration: 48 hrs, filling: $30\%$, pressure: 375 atm. As the results of characteristics for African rubies obtained under these conditions, it was known that the amount of $Cr^{3+},\;Fe^{3+},\;Ti^{4+}$ was reduced after the hydrothermal treatment from the ICP/MS and XRF analyses. Also, it was found that the red color from the colorimeter analyses was getting lighter. These results were consistent with the PL analysis showing that the intensity of the luminescence peak generated by the electron transition of $Cr^{3+}$ ion became lower after the hydrothermal treatment compared with the non-treated rubies.

• Journal of the Korean Ceramic Society
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• v.38 no.7
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• pp.648-653
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• 2001

구연산이 첨가된 0.01 M의 $\beta$-인산칼슘 용액을 수열처리 하여 휘스커 상 수산화아파타이트를 합성할 때 수열처리 온도 및 시간이 휘스커의 생성에 미치는 영향을 관찰하였다. 용액을 30$0^{\circ}C$에서 5시간 수열처리 할 때 c축으로 약 60-80$\mu\textrm{m}$까지 성장하고 비교적 순수한 휘스커를 얻을 수 있었으며 이렇게 합성된 수산화아파타이트 휘스커를 수산화아파타이트 시멘트에 1-2 wt% 첨가하였을 때 그 경화체의 직경인장강도는 약 4-6배까지 증가하였다.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.4
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• pp.821-826
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• 2012

p-ary sequences of period $N=2^k-1$ are widely used in many areas of engineering and sciences. Some well-known applications include coding theory, code-division multiple-access (CDMA) communications, and stream cipher systems. The analysis of cross-correlations of these sequences is a very important problem in p-ary sequences research. In this paper, we analyze cross-correlations of p-ary sequences which is associated with the equation $(x+1)^d=x^d+1$ over finite fields.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.2C
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• pp.153-157
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• 2009

In this paper, for even integer N, we propose a new construction method of quaternary low correlation zone(LCZ) sequence set from a binary LCZ sequence set with parameters (N,M,L,$\varepsilon$). Proposed method applies the inverse gray mapping from Krone and Sarwate to binary LCZ sequences and their phase shifts. The only needed condition of binary LCZ sequence set used in this construction is even period.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.16 no.6
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• pp.240-243
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• 2006

The significant color enhancement in low quality Australian natural sapphire has been achieved by a hydrothermal method. The optimal conditions for the color enhancement of Australian natural sapphire were as follows; hydrothermal reaction temperature: $320{\sim}350^{\circ}C$, duration : 3 days, hydrothermal solvent: 2 M NaOH solution. After the hydrothermal treatment, Australian natural sapphires of transparent colors were obtained, and their grades were found to be improved from commercial to middle/top grade by value chart analysis.

• The KIPS Transactions:PartC
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• v.10C no.7
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• pp.851-856
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• 2003

The LM generator is an improved summation generator with maximum period, near maximum linear complexity and maximum order of correlation immunity, and it has a property with the input-output correlation immunity In this paper, we propose the high-speed m-parallel LM-BSG and 8-parallel LM-BSG for detail as a design example. When compared with a conventional stream cipher, the properties of the proposed cipher exhibited the same crypto-degree (security) with a rt times faster processing.