• Proceedings of the Korean Information Science Society Conference
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• 2006.06c
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• pp.133-135
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• 2006

실시간 프로그램은 다양한 분야에서 사용되고 있으며, 그 개발자는 논리적, 시간적 정확성을 고려해야 한다. 시간적 정확성은 실시간 프로그램에서 가장 중요한 부분이며, 이를 위한 데드라인은 개발자에 의해 정의된다. 따라서 개발자는 데드라인의 정의를 위하여 기준점을 제시할 수 있는 정적 실행시간 분석이 필요하다. 정적 실행시간 분석에서 프로그램의 반복횟수 분석은 큰 비중을 차지한다. 현재 이러한 반복횟수 분석을 자동화하는 연구가 진행 중이다. 하지만 반복횟수 분석은 반복횟수에 영향을 주는 제어변수의 결정정책에 따라 결과가 달라지고, 자동화를 위한 반복횟수 계산 수식의 적용 범위가 제한되어 있다. 본 논문에서는 이러한 제어변수를 결정 및 탐색하고, 수집된 정보를 개선된 수식을 사용하여 반복횟수 분석을 수행할 수 있도록 PS-Block 구조를 기반으로 반복횟수 분석기를 설계 및 구현하였다. 반복횟수 분석기는 제어변수의 탐색 및 결정 분석 과정을 자동화하고, 수식의 개선으로 자동화 범위를 확대하며, 개별 반복 문 단위의 정밀한 반복횟수 분석을 통해 정확도를 높이고, 신뢰성을 향상시킬 수 있다.

• Korean Journal of Microbiology
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• v.47 no.4
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• pp.302-307
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• 2011

Native chitin deacetylase of Aspergillus nidulans was purified to apparent homogeneity by a combination of phenyl-Sepharose and Q-Sepharose column chromatography. In order to analyze the amino acid residues involved in the enzyme activity, the enzyme was chemically modified with chemical agent, which selectively reacted with the specific amino acid residue on the protein. When the enzyme was chemically modified with diethylpyrocarbonate, which specifically reacted with histidine residues on the protein, the activity was eliminated. The chitin deacetylase, chemically modified with 100 ${\mu}M$ modifier at the residue of arginine or tyrosine, has shown to have decreased activities. It was shown that the modification at aspartic acid or glutamic acid did not affect the enzyme activity to a greater extent, which would not implicate that acid amino residues were directly involved in catalytic reaction and would affect on the global structures of the proteins. This results demonstrated that histidine and tyrosine residues of enzyme would participate in an important function of the chitin deacetylase activity.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.3A
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• pp.259-266
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• 2009

This study is to develop equations that consider the elastic modulus ratio of FRP bar and steel reinforcement, shear span to depth ratio, and flexural reinforcement ratio of FRP bar, to determine concrete shear strength of FRP reinforced concrete beams without shear reinforcement. As experimental parameters, 2 types of FRP bar, 3 types of shear span to depth ratio, and 3 types of flexural reinforcement were used. Experimental results for two of shear span to depth ratio were quoted from previous study to evaluate effect of shear span to depth ratio in more detail. Shear strength correction factors needed for evaluating concrete shear strength were proposed from regression analysis using above experimental results. Equations suggested from this study and other codes were examined and compared with 31 experimental results available in the literature. From this comparison, it could be known that the equation suggested from this study gives the most approaching result to experimental results.

• Journal of Digital Contents Society
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• v.16 no.2
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• pp.317-324
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• 2015

In this paper, we analyze the optimum moving speed of taxi for maximum revenue. In the analysis, we vary taxi speed from 5km/h through 80km/h to see how revenue of a taxi varies applying the practical gas mileage of LPG taxi and taxi fare system in Korea. From the results of the analysis, we see that the probability that a taxi meets passengers goes high as taxi speed gets fast, however the fuel cost also goes up. We also obtain the optimum speed for the maximum revenue according to passenger distribution while varing moving speed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.8C
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• pp.697-708
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• 2010

In this paper, we compare the timing synchronization performance of the adaptive filter to that of the correlator in direct sequence spread spectrum (DS/SS) systems. The test variables used in the code synchronization are statistically analyzed for both schemes, and then the obtained results are used in calculating the detection and false alarm probabilities. Based on the derived probabilities, the synchronization performance is compared and the simulation is followed. Analysis and simulation results show that the correlator outperforms the adaptive filter under most synchronization environments.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.8C
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• pp.754-761
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• 2005

We derive and analyze a bit error rate(BER) expression of a Gray coded rectangular QAM(R-QAM) signal with maximal ratio combining diversity(MRC) reception over Nakagami-n(Rician) fading channels. The derived result is provided in terms of the Whittaker function and the confluent hypergeometric function. In addition, by performance comparison with M-PSK, we see the Nakagami-n fading channel characteristics. Because the derived expression is general, it can readily allow numerical e·valuation for various cases of practical interest such as line-of-sight (LOS) or satellite communication channel analysis.

• Analytical Science and Technology
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• v.20 no.3
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• pp.213-218
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• 2007

Copper(II) ion was measured with the use of a perfluorinated sulfonated polymer-ethylenediamine (nafion-en) modified glassy carbon electrode. The electrode mechanism was based on the chemical reactivity of an immobilized layer (nafion-en) to yield complex $[Cu(en)_2]^{+2}$. The reduction potential peak by differential pulse voltammetry(DPV) was observed at -0.4402V(${\pm}0.0050V$) (vs. Ag/AgCl). The linear calibration curve was obtained from $1.0{\times}10^{-6}$ to $1.0{\times}10^{-4}M$ copper(II) ion concentration, and the detection limit(3s) was $1.96{\times}10^{-6}M$.

• Journal of the Korea Computer Industry Society
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• v.5 no.5
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• pp.711-720
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• 2004

There are conversion of expression motion and assignment motion inclusive espression motion in techniques that optimized program computationally and livelly. In this paper, I suggest that an algorithms of reconstruct unnecessary code motion which is improves Knoop's algorithms that have ambiguous. It is occurred by mixing the node level analysis and the instruction level analysis. This algorithm improves runtime and efficiency of a program by avoiding the unnecessary recalculations and reexecutions of expressions and assignment statements.

• Journal of Korea Multimedia Society
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• v.15 no.7
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• pp.951-961
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• 2012

E-books produced in the country provide limited audio service for reading disables. The reason is that those books cannot translate the mathematical expressions and symbols in the context. In this paper, the 'Math Expression Reader' was implemented that can translate the expressions and symbols in the document into Korean speech for those who have reading disabilities. The math to speech generated by this program has been tested to both the public and reading disables and the results of this test has been compared whether they can exactly understand the speech and evaluated the reading rules.

• Journal of the Korean School Mathematics Society
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• v.20 no.2
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• pp.141-161
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• 2017

As it's important to understand the order of operation in the mixed calculation of natural number and perform it, mathematics curriculums and textbooks focused that students can calculate with understanding the order of operation and its principles. For attaining the implications of teaching about the mixed calculations, this study analyzed the problem solving abilities and error types of 67 elementary students and 57 pre-service teachers using questionnaire which was developed in this study and composed of numeric expressions and word problems. The conclusions drawn from this study were as follows: Students were revealed the correct rates(86.2% and 73.5%) in numeric expressions and word problems, but they were showed the paradigmatic error types-the errors of the order of operation and the composition of numeric expression from word problems. Even though the correct rates of the preservice teachers were extremely high, the result of problem solving processes required that it's needed to be interested in teaching the principles of the order of operation in the mixed calculations. In addition, subjects were revealed the problems about using parentheses and equal sign.