• 한국구조물진단유지관리공학회 논문집
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• 제3권3호
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• pp.203-211
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• 1999

This study is to examine the feasibility of carbon fiber sheet(CFS), a kind of fiber reinforced plastic(FRP), for a repair and reinforcement of R/C beams. The flexural strength of R/C beams, that were preloaded and then the cracks were repaired, maintains that of the uncracked R/C beams. The flexural strength of R/C beams increases with the reinforcement of CFS. In order to practically apply the repair and reinforcement method, further research is needed for the distribution, amount, and bond of CFS. In this study, an experiment was conducted for R/C beams reinforced with CFS, for various wrapping method and amounts of CFS. Experimental results showed the wrapping method increasing the bond area and amount of CFS layer caused the increase in the strength of the beams. It is found that the strength of CFS should be used as 70% of the maximum strength in retrofitting reinforced concrete beams in evaluating flexural capacity on the basis of ultimate strength design method.

• ETRI Journal
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• 제39권3호
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• pp.364-372
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• 2017

For the reliability of controllers in a software defined network (SDN), a dynamic and self-learning schedule method (DSL) is proposed. This method is original and easy to deploy, and optimizes the combination of multiple controllers. First, we summarize multiple controllers' combinations and schedule problems in an SDN and analyze its reliability. Then, we introduce the architecture of the schedule method and evaluate multi-controller reliability, the DSL method, and its optimized solution. By continually and statistically learning the information about controller reliability, this method treats it as a metric to schedule controllers. Finally, we compare and test the method using a given testing scenario based on an SDN network simulator. The experiment results show that the DSL method can significantly improve the total reliability of an SDN compared with a random schedule, and the proposed optimization algorithm has higher efficiency than an exhaustive search.

• 대한산업공학회지
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• 제1권1호
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• pp.57-65
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• 1975

A perfect evaluation for scientists and engineers is impossible unless the R&D process is fully explored. But the study in this area is being intencified, and consequently progress is being made. In this paper an evaluation method for scientists and engineers in project-oriented R&D organizations is developed. That is, a method that the evaluation for the job performance directly influences personnel management such as promotion, and the evaluation for their potential, characteristics influences indirectly. Further systematization of evaluation process, which is no less importatant than evaluation itself, is attempted.

• 한국약용작물학회지
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• 제24권4호
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• pp.271-276
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• 2016

Background: In the present study, we established an HPLC (high performance liquid chromatography)-analysis method for the determination of marker compounds as a part of the material standardization for the development of health-functional foods from Salvia plebeia R. Br. extract. Methods and Results: The quantitative determination method of hispidulin as a marker compound was optimized by HPLC analysis using a YMC hydrosphere C18 column with a gradient elution system. This method was validated using specificity, linearity, accuracy, and precision tests. It showed a high linearity in the calibration curve with a coefficient of correlation ($r^2$) of 0.999995. The method was fully validated, and was sensitive, with the limit of detection (LOD) at $0.09{\mu}g{\cdot}m{\ell}^{-1}$ and limit of quantification (LOQ) at $0.27{\mu}g{\cdot}m{\ell}^{-1}$. The relative standard deviation (RSD) values of the data from intra- and inter-day precision were 0.05 - 0.22% and 0.32 - 0.42%, respectively, and the intra- and inter-day accuracy of hispidulin were 99.5 - 102.3% and 98.8 - 101.5%, respectively. The average content of hispidulin in Salvia plebeia R. Br. extract was $3.945mg{\cdot}g^{-1}$ (0.39%). Conclusions: These results suggest that the developed HPLC method is very efficient, and that it could contribute to the quality control of Salvia plebeia R. Br. extracts as a functional ingredient in health functional foods.

• 한국컴퓨터정보학회논문지
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• 제16권8호
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• pp.103-108
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• 2011

대표적인 소수판별법으로 밀러-라빈방법이 적용되고 있다. 밀러-라빈판별법은 m=[2, n-1]에서 m을 k개 선택하여 n-1=$2^sd$, $0\;{\leq}\;r\;{\leq}\;s-1$ 에 대해 $m^d\;{\equiv}\;1(mod\;n)$ 또는 $m^{2^rd}\;{\equiv}\;-1(mod n)$로 소수를 판별하여 $k{\times}r$회를 수행한다. 본 논문은 c=$p^{\frac{n-1}{2}}(mod\;n)$을 계산하여 c=-1이면 소수로 판별하여 k회 수행하였다. 제안된 판별법은 밀러-라빈 판별법의 $k{\times}r$회를 k회로 감소시켰다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.783-787
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• 2007

Nowadays, vehicle becoming necessity is increasing gradually and is main cause of environmental problem. The current automobile noise measurement test method such as ISO 362 which have been used many countries contribute seriously to enforce the regulation of the noise rigidly and actively study vehicle's noise, using that method. However, the amendment of ISO 362 was completed under the international agreement due to the changes in vehicle's techniques and road conditions. In this study, the difference between the current ISO 362(or ECE R51) and new ISO 362(or new ECE R51) is estimated by the test using the practical car producing domestically because the Korean manufacturer have to be interested in new test method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.396-398
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• 2005

IEC 60287-3-2 standards suggests the selection method of economic conductor size for power cables. This method deals solely with the economic choice of conductor size based on joule losses. This paper introduces the method and example study which is proposed by IEC standards.

• 한국해양공학회지
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• 제7권2호
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• pp.91-102
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• 1993

The elastic-plastic fracture thoughness J sub(IC) of Nuclear Reactor Vessel Steel(SA 508-3) which has high toughness was discussed at temperatures RT, $-20^{\circ}C$, $200^{\circ}C$ and 1/2/CT specimen was used for this study. Especially the two methods recommended in ASTM and JSME were compared. It was difficult to find J sub(IC) by ASTM R-curve method with the specimen used for this research, while JSME R-curve method yielded good result. The stretched zone width menthod gave slightly larger J sub(IC) values than those by the R-curve method for SA 508-3 steel.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.97-103
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• 2006

A modified one-sided measurement technique is proposed for Rayleigh wave (R-wave) velocity measurement in concrete. The scattering from heterogeneity may affect the waveforms of R-waves in concrete, which may make the R-waves dispersive. Conventional one-sided techniques do not consider the scattering dispersion of R-waves in concrete. In this study, the maximum energy arrival concept is adopted to determine the wave velocity by employing its continuous wavelet transform. Experimental study was performed to show the effectiveness of the proposed method. The present method is applied to monitor the strength development of early-age concrete. A series of experiments were performed on early-age concrete specimens with various curing conditions. Results reveal that the proposed method can be effectively used to measure the R-wave velocity in concrete structures and to monitor the strength development of early-age concrete.

• 생약학회지
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• 제38권1호
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• pp.19-21
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• 2007

Myristica fragrans has been used for the treatment of stomachache in East Asia. It is very important to determine the amount of myristicin in Myristica fragrans, because excess myristicin causes side effects. In this study, we developed and validated the method for determination contents of myristicin in Myristica fragrans which was purchased from various regions of Korea. The average content of myristicin in Myristica fragrans was 2.10% with the validated HPLC analysis method.