• Architectural research
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• 제19권3호
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• pp.71-77
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• 2017

Dynamic pricing refers to a system in which a tariff varies, according to a level of charging and applied time depending on time change. The power billing system used in the Korean Electric Power Corporation (KEPCO) is based on time of use (TOU) pricing, which is one of the dynamic pricing systems. This paper aimed to determine the operational results of a variable refrigerant flow system, to which a new control algorithm was applied, in order to respond to dynamic pricing, in summer and the utility of the new control. To do this, real measured data was acquired from a VRF system installed in a building for educational purposes, where dynamic pricing was applied for about 100 days during summer time. At the maximum load operation time period in TOU, the new control minimized operation within the indoor comfort range, an increase in refrigerant evaporation temperature in the indoor unit and the number of revolutions in a compressor in the outdoor unit was limited. As a result, power usage was decreased by 11%, and the operational cost by 14.6%. Furthermore, measurement results using the Predicted Mean Vote (PMV) model, that represented satisfaction of thermal environment, showed that 82.8% to 90.4% of the occupants of the building were satisfied during operation when the new control was applied.

• 센서학회지
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• 제31권5호
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• pp.353-359
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• 2022

This study investigated via computational analysis the application utility of series-cascaded ring resonators based on silicon-on-insulator (SOI) slot optical waveguides in integrated optical biochemical sensors. The radii of the two rings in the series-cascaded ring resonators were 59.4 ㎛ and 77.6 ㎛ respectively, and the coupling distance was 0.5 ㎛. The series-cascaded ring resonators were computationally analyzed using FIMMProp and PICWave numerical software. The free spectral range (FSR), full width at half maximum (FWHM), sensitivity, and quality-factor (Q-factor) of the series-cascaded ring resonators were 12.2 nm, 0.134 nm, 4100 nm/RIU, and 11580, respectively, and the measurement range was calculated to be slightly smaller than 3×10^-3 RIU. Although the measurement range was smaller than that of the single ring resonator, upon considering other characteristic parameters, the series-cascaded ring resonators are found to be more effective as integrated sensors than single ring resonators.

• 전기학회논문지P
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• 제64권4호
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• pp.286-290
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• 2015

Power system is composed of a number of power devices and equipment. This factor affects the power quality is also displayed very complicated and varied. The accurate measurement and analysis of the causes of power quality problems is difficult. In preparing for these issues, there are many difficulties. In this study, Power quality of A public establishment of Chungbuk province were measured and analyzed. Measurement results of the fifth harmonic current was very large. Accordingly, the harmonic reduction will be needed. This research will be utilized as fundamental data to improve power quality for power utility and customer.

• 대한치과교정학회지
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• 제29권4호
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• pp.411-424
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• 1999

Utility arch wire를 이용한 상악 4절치 압하시 중절치와 측절치의 초기 응력 분포를 알아보기 위하여 컴퓨터 단층 촬영된 정상 교합자의 치아 사진으로부터 유한요소 모델을 만든 후 beam요소로 만든 utility arch wire의 구치부에 $45^{\circ}$ tipback을 부여하고 전치부에 $5^{\circ},\;10^{\circ},\;15^{\circ}$ crown lingual torque를 부여하여 activation한 후 치아와 치근막 유한요소 모델에 적용하여 해를 구한 다음 중절치와 측절치의 치경부, 치근 중간부, 치근첨부의 세 부분에서 초기 응력분포를 조사하여 다음과 같은 결론을 얻었다. 1. 중절치는 $5^{\circ},\;10^{\circ},\;15^{\circ}$ activation 했을 때 치경부의 원심 구개측과 치근첨의 근심 순측에서는 압축이, 치경부의 근심순측과 치근첨의 원심 구개측에서 약한 인장이 나타나는 양상이 각각의 경우에 거의 비슷하게 나타났다. 주응력의 크기 또한 거의 비슷하였다. 그러나 $10^{\circ}$ activation 했을 때 그 양상이 가장 강하였다. 2. 측절치는 $5^{\circ},\;10^{\circ},\;15^{\circ}$ activation했을 때 치경부의 순측과 치근 첨부의 구개측에서 압축이 치경부의 구개측과 치근첨부의 순측에서 인장이 나타나는 양상이 각각의 경우에 거의 비슷하게 나타났다. 그러나 $10^{\circ}$ activation했을 때 그 양상이 가장 강하였다.

• 전자공학회논문지SC
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• 제45권6호
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• pp.141-148
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• 2008

신재생 에너지 분야에서 각광받고 있는 계통 연계형 태양광 인버터에서는 계통과의 연계를 위해서 반드시 계통의 위상 정보가 필요하다. 본 논문에서는 계통 연계형 태양광 발전 시스템에서의 위상 동기화 방법으로 원하는 기준 신호의 주파수를 구하여 동기신호로 사용하고, DFT(Discrete Fourier Transform) 알고리즘을 이용하여 기준 신호와의 위상차를 구하여 위상차만큼 보상하는 PLL(Phase Locked Loop)의 순시 추종방법을 제안하였다. 또한 DFT 연산에 사용되는 한주기 값들을 샘플링 할때마다 보정 위상 값을 구하는 방법과 특정 주파수의 기준신호에 대한 주파수 및 위상 추종뿐만 아니라 다양한 주파수 신호에 대한 주파수 및 위상을 추종하는 방법을 적용하여 시뮬레이션과 실험을 통해 본 논문의 타당성을 검증하여 유효성을 보이고자 한다.

• 동아시아식생활학회지
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• 제16권3호
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• pp.242-250
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• 2006

The purpose of this study was to identify tourist product factor combinations which confer the highest utility to tourists and to establish the relative importance of factors in terms of their contribution to total utility across gender. Among 250 questionnaires, 230 questionnaires were utilized for the analysis. $X^2$ analysis, Conjoint model, Max. Utility model, BTL model, Logit model, K-means cluster analysis, and one-way anova analysis were used for this study. The findings from this study were as follows. First, the Pearson's R and Kendall's tau statistics showed that the model fitted the data well across gender. Second, it was found that total respondents and three clusters regarded taste price as the very important factor across gender. Third, it was found that the male and female tourists most preferred product with light red color, shaped package, and highly pungent taste sold at a cheap price in factory. Fourth, it was found that the male tourists most preferred simulation product with light red color, shaped package, and highly pungent taste sold at a cheap price in factory. The female tourists most preferred simulation product with light red color, shaped package, and mild taste sold at a cheap price in factory. Finally, the results of the study provide some insights into the types of effective product designs that can be successfully developed by marketers.

• 기술경영경제학회:학술대회논문집
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• 기술경영경제학회 1999년도 제15회 하계 학술발표회 논문집
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• pp.245-265
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• 1999

MAUT and AHP are widely used for quantification of subjective judgements in various fields of decision making. This study focuses on the introduction and application of MAUT/AHP method which is a hybrid of MAUT and AHP techniques in R&D project priority setting. This hybrid model can clarify each factors' contribution using MAUT method and can reduce the number of pairwise comparisons of AHP method. This study applies AMUT/AHP method to the evaluation of R&D projects in a Government - funded research institute. To evaluate R&D projects, six evaluation factors are derived. SMART(Simple MultiAttribute Rating Technique) and DVM(Difference Value Measurement ) out of many MAUT methods are used to design the utility function ad AHP is used to allocate the weights among evaluation factors. The major findings of this study can be summarized as follows. First, the SMART/AHP and the DVM/AHP have the same results with the SMART and the DVM, and they are different results with AHP. It is very hard to decide which one is better. Second, MAUT/AHP's strength is analyzed. MAUT reflects utility values of evaluators to alternatives and AHP results objective and consistent weights of factors through pariwise comparisons. Third, its possible application fields are proposed. It is applicable to subjective decision making problems with high complexity and inter-independent factors.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.826-831
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• 2002

In order to investigate the dynamic characteristics of real structure, many dynamic engineer had been interested in modal test however it is not easy to perform dynamic test of large structure because of many difficulties such as unsatisfied excitation force in global mode frequency range, measurement of dynamic force and so on. Therefore. new type vibration exciter with variable stiffness support system and dynamic force was developed to provide a improved experimental environment for a large and complex structure. The developed exciter improved from two viewpoint, dynamic performance and utility convenience. its characteristics was shown in this paper.

• 한국자동차공학회논문집
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• 제10권5호
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• pp.129-137
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• 2002

Elastomers, which are used engine mounts and body mount rubbers, are traditionally designed for NVH use in vehicles, and for vibration isolation in specific frequency range. According to the measurement of the characteristics of the SUV's engine mounts, there are variability in same engine mount properties. Static and dynamic stiffness of the SUV's engine mounts are changed due to the driving miles accumulated. The pre-load of body mount rubbers are changed due to the empty vehicle weight, passenger's weight and gross vehicle weight. And the dynamic stiffness of body mount rubbers are changed very hard above 150Hz frequency range.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2007년도 춘계학술대회 논문집
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• pp.203-205
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• 2007

A method is proposed in this paper to determine the harmonic contributions of a customer at the point of common coupling. The method can quantify customer and utility responsibilities for limit violations caused by either harmonic source changes or harmonic impedance changes. It can be implemented in current power quality monitors and digital revenue meters. The method is comparison of measurement phase angles between harmonic voltage and current. The proposed method has been applied to the test system. The study results have indicated the accuracy of harmonic injection and emission for customer and utility.