• 대한전자공학회논문지TC
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• 제38권2호
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• pp.6-12
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• 2001

CBR 소스 트래픽에 대한 ATM 교환기와 광대역 망종단장치의 셀전달지연을 측정하여 국내영역에서의 셀전달지연을 추정하였다. 추정결과 I.356의 할당원칙에 의한 국내영역의 셀전달지연 목표치를 만족하였다. Chernoff 누적방법에 기초한 peak to peak CDV 할당방법을 제안하고 국내영역의 노트들에 적용하였다. 수치해석 결과 전송경로상에 놓인 노드수와 각 노드에서의 CDV가 증가하는 경우에 제안된 할당방법이기존의 균등할당 방법에 비해 정확도가 개선되었다.

• 전기학회논문지
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• 제67권11호
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• pp.1415-1422
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• 2018

In Korea, prior to 2011, the electric reserve margin followed the probabilistic reliability view and the planning reserve margin had been operated at about 15% based on the assumption that power outage was permitted within 0.5 days a year. However, after experiencing the shortage of the electric generation capacity in Sept. 15, 2011, the planning reserve margin was selected as 22% to improve the reliability of the electric supply. In this paper, using panel data of 28 OECD countries over the period 2000-2014 we attempted to empirically examine the linkage between reserve margin, electricity tariffs, renewable energy share, GDP per capita, and summer / winter peak-to-peak ratios. As a result, all four independent variables have been significant for the electric reserve margin, and in particular, we found that countries with similar peaks in winter and summer have operated 4.3% higher reserve margin than countries experiencing only summer peak.

• Journal of the Optical Society of Korea
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• 제20권1호
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• pp.150-155
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• 2016

To evaluate the autofocusing performance of recent mobile phone cameras, it is necessary to determine the peak position of the center field MTF (Modulation Transfer Function), -known as the through focus MTF- of the module. However, the MTF peak position found by conventional methods deviates from the ideal position due to the focus scanning resolution of mobile phone cameras. This inaccurate peak position results in false judgements of the optical performance, leading to yield losses or customer complaints. An increase in the focus scanning resolution can address this problem, but the manufacturing UPH (Unit per Hour) level will also unfortunately increase as well, resulting in a loss of manufacturing capabilities. In this paper, several fitting models are studied to find an accurate MTF peak position within a short period of time. With an analysis of a large amount of manufacturing data, it is demonstrated that the fitting methods can reduce false judgements and simultaneously increase the capabilities of the manufacturing system.

• 전자공학회논문지A
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• 제32A권7호
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• pp.51-57
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• 1995

The theoretical analysis for AlInAs/GaInAs resonant tunneling diodes (RTDs), which have shown the improved negative differential resistance (NDR) characteristics, has scarcely been made in comparison with AlGaAS/GaAs RTDs. In this paper, the static current-voltage relation of Al$_{0.48}In_{0.52}As/Ga_{0.47}In_{0.53}$As RTDs were numerically estimated by using a self-consistent method. Assuming a simplified RTD with single quantum well structure and spacer layers, the peak current density (J$_{P}$) and the peak-to-valley current ratio (PVCR) were analysed as the function of the thickness of the well, the barrier and the spacer layer, and temperature. As the results, the peak current density and the peak-to-valley current ratio indicated a reciprocal relation roughly in respect to the thicknesses of the well and the barrier, and it was theoretically predicted that it be not attainable to provide a high peak current desity (J$_{P}$) over 1${\times}10^{5}A/cm^{2}$ as well as the large peak-to-valley current ratio (PVCR) over 10 that were the the critical conditions for the practical use.

• 물과 미래
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• 제29권3호
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• pp.153-161
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• 1996

최근에 도시화 된 산본천 유역을 대상으로 한 유출 해석이다. 실측한 각종 자료를 유출해석 모형인 ILLUDAS를 이용하여 도시화에 따른 첨두유량과 총유출량의 연구를 분석하였다. 도시하천에서 첨두유량의 증가는 도시화에 따른 하정비가 가장 큰 영향이 있는 것으로 판단된다. 첨두유량은 강우 지속시간이나 재현기간에 따라 조도계수 n=0,04일 경우에 최대 10%까지, n=0.015일 경우는 7~16%이었으며, 또한 자연하도(n=0.04)에서 계획하도(n=0.015)로 변화하면 첨두유량은 51~158%까지 큰 폭의 증가를 보였다. 일반적으로 호우시 홍수첨두유량은 증가하지만 도시유역의 경우는 배수계통의 정비로 유속이 증가하면서 하천 수위는 오히려 감소하는 것으로 나타났다.

• Journal of Astronomy and Space Sciences
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• 제33권4호
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• pp.247-256
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• 2016

An analysis of light curves and spectra of observed gamma-ray bursts in gamma-ray ranges is frequently demanded because the prompt emission contains immediate details regarding the central engine of gamma-ray bursts (GRBs). We have revisited the relationship between the collimation-corrected peak luminosity and the spectral lag, investigating the lag-luminosity relationships in great detail by focusing on spectral lags resulting from all possible combinations of channels. Firstly, we compiled the opening angle data and demonstrated that the distribution of opening angles of 205 long GRBs is represented by a double Gaussian function having maxima at ~ 0.1 and ~ 0.3 radians. We confirmed that the peak luminosity and the spectral lag are anti-correlated, both in the observer frame and in the source frame. We found that, in agreement with our previous conclusion, the correlation coefficient improves significantly in the source frame. It should be noted that spectral lags involving channel 2 (25-50 keV) yield high correlation coefficients, where Swift/Burst Alert Telescope (BAT) has four energy channels (channel 1: 15-25 keV, channel 2: 25-50 keV, channel 3: 50-100 keV, channel 4: 100-200 keV). We also found that peak luminosity is positively correlated with peak energy.

• 전기학회논문지
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• 제63권1호
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• pp.27-34
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• 2014

The paper proposed a sizing method of an energy storage system(ESS) for peak shaving of high-speed railway substations based on load profile patterns of substations. A lithium based battery ESS was selected since it can produce high-power at high speed that peak shaving requires, and also takes up a relatively smaller space for installation. Adequate size of the ESS, minimum capacity which can technically meet a peak shaving target, was determined by collectively considering load patterns of a target substation, characteristics of the ESS to be installed, and optimal scheduling of the ESS. In case study, a local substation was considered to demonstrate the proposed sizing method. Also economic analysis with the determined size of ESS was performed to calculate electricity cost savings of the peak shaving ESS, and to offer pay-back period and return on investment.

• 전기학회논문지
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• 제67권9호
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• pp.1152-1158
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• 2018

In this paper, Optimal operation plan through load analysis of industrial end-user is suggested. It calculated economic feasibility of ESS with detailed power lad analysis and conditions. Generally, if the latest maximum power is less than 30% of contracted power, it can not be peak shaving operation plan. and if the peak load level stays stead for 24 hours, it is difficult peak shaving for ESS. In addition to, When the peak load is occurred in summer or winter, a hybrid operation method combining the peak shaving plan and the time shift method is proposed. Therefore, When ESS is installed in industrial electrical customer, it is achieved best effect through the optimal operation plan.

• 한국전문물리치료학회지
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• 제22권2호
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• pp.41-51
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• 2015

The purposes of this study were 1) to determine the effects of low-dye taping on peak plantar pressure following treadmill walking exercise, 2) to determine whether the biomechanical effectiveness of low-dye taping in peak plantar pressure was still maintained following removal of the tape during treadmill walking, and 3) to determine the trend towards a medial-to-lateral shift in peak plantar pressure in the midfoot region before and after application of low-dye taping. Twenty subjects with flexible flatfoot were recruited using a navicular drop test. The peak plantar pressure data were recorded during five treadmill walking sessions: (1) un-taped, (2) baseline-taped, (3) after a 10-minute treadmill walking exercise, (4) after a 20-minute treadmill walking exercise, and (5) after removal of the taping. The foot was divided into six parts during the data analysis. One-way repeated measures analysis of variance was performed to investigate peak plantar pressure variations in the six foot parts in the five sessions. This study resulted in significantly increased medial forefoot peak plantar pressure compared to the un-taped condition (p=.017, post 10-minute treadmill walking exercise) and (p=.021, post 20-minute treadmill walking exercise). The peak plantar pressure in the lateral forefoot showed that there was a significant decrease after sessions of baseline-taped (p=.006) and 10-minute of treadmill walking exercise (p=.46) compared to the un-taped condition. The tape removal values were similar to the un-taped values in the five sessions. Thus, the findings of the current study may be helpful when researchers and clinicians estimate single taping effects or consider how frequently taping should be replaced for therapeutic purposes. Further studies are required to investigate the evidence in support of biomechanical effectiveness of low-dye taping in the midfoot region.

• 대한인간공학회지
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• 제25권3호
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• pp.17-24
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• 2006

In this paper, we propose a stress analysis on foot by lifting task attitudes. Maximum force and peak pressure were measured on 8 body regions by Pedar system in order to analysis the stress which is affected by task style and angle on foot when Manual Materials Handling task. As for the peak pressure of the whole foot as to the task height during the lifting task, the height from Knuckle to Shoulder was the least in the peak pressure. Also, as for the maximum force and the peak pressure of the whole foot as to the task angle during the lifting task, it could be seen that the more an angle increases, the stress influencing on a foot jumps. As for the maximum force and the peak pressure by foot region as to the task height in case of the lifting task, the height from Knuckle to Shoulder is indicated the smallest value in the maximum force and the peak pressure, thus there is necessary to attain the work design that considered this. Also, as for the maximum force by foot region as to the task angle in case of the lifting task, 0° tasking is indicated to be least, thus there is necessity to be attained the tasking design in a bid to prevent the existence of an angle. The results of this paper are thought to be helpful to the suitable work design, to the prevention of musculoskeletal disorders related to the lower limbs, and to the design of ergonomic safety shoes.