• International Journal of Fuzzy Logic and Intelligent Systems
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• 제14권4호
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• pp.305-312
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• 2014

This paper discusses real-time peak shaving algorithms for a large-scale battery energy storage system (BESS). Although several transmission and distribution functions could be implemented for diverse purposes in BESS applications, this paper focuses on a real-time peak shaving algorithm for an energy time shift, considering wind power generation. In a high wind penetration environment, the effective load levels obtained by subtracting the wind generation from the load time series at each long-term cycle time unit are needed for efficient peak shaving. However, errors can exist in the forecast load and wind generation levels, and the real-time peak shaving operation might require a method for wind generation that includes comparatively large forecasting errors. To effectively deal with the errors of wind generation forecasting, this paper proposes a real-time peak shaving algorithm for threshold value-based peak shaving that considers fuzzy wind power generation.

• 대한교통학회지
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• 제21권6호
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• pp.27-42
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• 2003

공항개발 사업을 계획하는 데 있어서 가장 기본이 되는 요소는 항공수요 중에서도 첨두시의 수요이다. 통상 첨두시 수요를 근거로 공항시설의 소요규모를 정하는 것이 일반적이며 시설용량의 포화 정도를 가늠할 때도 첨두시 수요를 기준으로 한다. 첨두운항의 형태는 해당 공항을 이용하는 항공 노선의 특성, 공항의 지리적 위치, 공항을 이용하는 여객 및 화물의 특성 등에 따라서 다르게 나타나며, 첨두수요는 첨두시간계수에 의해 산출된다. 지금까지 국내의 공항건설계획에서 채택해온 첨두특성과 첨두시간계수는 외국의 연구결과에 따른 것이었다. 그러나 이들 기존의 연구결과가 제시하는 다양한 첨ㄷ특성이나 첨두시간계수가 국내 실정에 적합한 지의 여부는 아직 공식적으로 확인된 적이 없다. 본 논문에서는 최근 10년간의 국내 공항별 항공운송 실적통계와 5년간의 공항별 운항스케줄을 이용하여 시간대별 운항패턴과 첨두특성을 분석하였다. 그리고 공항별 첨두시간계수를 산출하고 기존의 연구결과와 비교분석하였으며, 국내공항의 사업계획을 위한 연간운항회수별 첨두시간계수를 제시하였다. 또한 공항별로 시간대별 주기장 소요를 분석함으로써 운항특성에 따라 주기장 소요가 어떤 양상을 보이는지 연구하였다.

• 한국콘텐츠학회논문지
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• 제19권1호
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• pp.174-186
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• 2019

본 연구는 고령인력 증가가 다른 영역보다 빨리 진행되며, 인적자원관리가 쉽지 않은 공기업 임금피크 근로자의 인구 경제 조직적 특성과 임금피크제 및 퇴직 간 관계에 대해 살펴보고자 하였다. 연구대상은 임금피크제 실시 공기업 19개사에 종사하는 임금피크 근로자 211명이었다. 연구결과에 따르면 인구 경제적 특성에 있어서, 교육수준, 가계총수입, 퇴직 후 생활비, 퇴직대비저축과 투자금액은 임금피크만족도, 임금피크수용도, 퇴직준비와 퇴직태도에 영향을 미치는 것으로 나타났다. 조직적 특성에서는 직급과 직군, 근무기간과 정년퇴직잔여기간, 퇴직준비프로그램 참여 그리고 임금피크 적용 여부에 따라 각각 차이가 나타났다. 연구 결과를 바탕으로 고령사회를 위한 실효성 있는 임금피크제 시행을 위해서는 복지지원, 교육훈련, 전직지원과 같은 고령친화인사제도의 직군, 직급, 경제수준 및 교육수준 별 시행의 필요성을 시사함과 동시에 후속 연구를 위한 제언을 논의하였다.

• 한국결정학회지
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• 제11권3호
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• pp.137-146
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• 2000

The stoichiometric mix of evaporating materials for he CuInS₂ single crystal thin films was prepared. To obtain the single crystal thin films, CuINS₂ mixed crystal was deposited on etched semi-insulator GaAs(100) substrate by the hot wall epitaxy(HWE) system. The source and substrate temperature were 640℃ and 430℃, respectively and the thickness of the single crystal thin films was 2 ㎛. The crystalline structure of single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction(DCXD). The carrier density and mobility deduced from Hall data are 9.64x10/sup 22//㎥ and 2.95x10/sup -2/ ㎡/V·s, respectively at 293 K. he optical energy gap was found to be 1.53 eV at room temperature. From the photocurrent spectrum obtained by illuminating perpendicular light on the c-axis of the thin film, we have found that the values of spin orbit coupling splitting ΔSo and the crystal field splitting ΔCr were 0.0211 eV and 0.0045 eV at 10K, respectively. From PL peaks measured at 10K, were can assign the 807.7 nm (1.5350 eV) peak to E/sub x/ peak of the free exciton emission, the 810.3 nm(1.5301 eV) peak to I₂ peak of donar-bound exciton emission and the 815.6 nm(1.5201 eV) peak to I₁ peak of acceptor-bound excition emission. In addition, the peak observed at 862.0 nm(1.4383 eV) was analyzed to be PL peak due to donor-acceptor pair(DAP).

• Journal of Pharmaceutical Investigation
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• 제40권3호
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• pp.193-200
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• 2010

The objective of this study was to investigate the effects of sample preparation, HPLC conditions and peak measurement methods upon determining progesterone content of poly-d,l-lactide-co-glycolide microspheres. A series of the microspheres with different formulations was first prepared. To determine their actual drug contents, the microspheres were dissolved in tetrahydrofuran and diluted with various amounts of methanol to precipitate the polymer. After removal of polymeric precipitates, the filtrates were subject to HPLC analysis under versatile experimental conditions. Interestingly, the composition of a sample solution (e.g., the ratio of methanol to tetrahydrofuran) affected the magnitudes of both peak fronting and peak broadening of progesterone. Its peak became broader and more asymmetrical at lower methanol:tetrahydrofuran ratios. Furthermore, its peak height was influenced by the proportion of tetrahydrofuran in a sample solution. Such problems encountered with tetrahydrofuran were exacerbated when a larger volume of the sample solution was injected onto an analytical column. Under our experimental conditions a peak area measurement provided more accurate and reliable determination of progesterone content in various microspheres than a peak height determination. Optimizing the composition of a sample solution, HPLC chromatographic conditions and peak analysis methods was a prerequisite to an accurate determination of progesterone encapsulated within microspheres.

• 한국광학회지
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• 제5권1호
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• pp.37-44
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• 1994

유도 브릴루앙 반사광을 고출력 레이저에 응용할 때 요구되는 반사광 특성이 실험적으로 조사되었다. 집속 렌즈의 초점거리에 따른 유도 브릴루앙 반사광의 peak power 반사율과 위상공액도가 측정되었다. 또한 반사광 가운데 펄스압축된 부분만의 위상공액도가 측정되었다. 초점거리가 긴 경우(f=100cm) 반사광의 peak power가 입사광의 약 2배에 이르렀다. 이때 반사광 중에서 압축된 선두펄스만의 위상공액도는 약 90%로 다른 시간의 펄스보다 위상공액도가 우수했다. 공간적으로는 유도 브릴루앙 이득이 가장 큰 광축부분의 바사관이 최대의 펄스압축, peak power 반사율, 위상공액도를 보여서 유도 브릴루앙 산란을 응용할 때 가장 유용한 부분으로 확인되었다.

• 한국전문물리치료학회지
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• 제13권3호
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• pp.75-83
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• 2006

The purpose of this study was to examine the isokinetic moment of quadriceps and hamstring strength ratio among women of different ages. The study population consisted of 1,184 women referred to the Health Promotion Center at the S district. All subjects were aged 20 to 69 years old and divided into 5 groups; 20s (n=248), 30s (n=255), 40s (n=248), 50s (n=228), and 60s (n=205). The strength of the knee extensor and flexor, quadriceps, and hamstring of all the participants were assessed at 60 degrees/second with an isokinetic machine. We calculated the peak torque, peak torque %BW (%Body Weight), deficit of peak torque and hamstring/quadriceps ratio of the knee. The data were analyzed by one way ANOVA to investigate statistical differences in strength variation between different age groups and were computed by ${\Delta}%$ difference from women in their 20's. The results were obtained as follows: 1. Peak torque of the knee extensor, quadriceps, were significantly reduced in women older than 30, but peak torque of the knee flexor, hamstring, were significantly reduced in women older than 50 compared to women in their 20's. (p<.05). 2. Peak torque %BW of the knee extensor, quadriceps, were significantly reduced in women older than 20, but peak torque %BW of knee flexor, hamstring, were significantly reduced in women older than 40 compared to women in their 30's (p<.05). 3. Compared to the women in their 20's, there was no significant difference among any of the age groups in the deficit of peak torque of the knee extensor and flexor, but the deficit of peak torque of knee extensor among women between 30 and 50showed significant difference within the normal range of deficit. 4. Compared to the women in their 20's, there was no significant difference among any of the age groups in the hamstring/quadriceps ratio These results showed that peak torque, peak torque %BW, deficit of peak torque, and hamstring/quadriceps ratio of the knee were reduced in each age group, but especially among the women over 50. Further longitudinal study may be needed to see if volume of muscle mass and intervention of exercise affect knee strength in spite of aging.

• 한국도로학회논문집
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• 제20권3호
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• pp.85-92
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• 2018

PURPOSES : In this study, analyze the characteristics of IOC indicator 'threshold' which is needed when evaluating the traffic signal operation status with ESPRESSO in various grade road traffic environment of Seoul metropolitan city and derive suggested value to use in field practice. METHODS : Using the computerized database program (Postgresql), we extracted data with regional characteristics (Arterial, Collector road) and temporal characteristics (peak hour, non-peak hour). Analysis of variance and Duncan's validation were performed using statistical analysis program (SPSS) to confirm whether the extracted data contains statistical significance. RESULTS : The analysis period of the main and secondary arterial roads was confirmed to be suitable from 14 days to 60 days. For the arterial, it is suggested to use 20 km/h as the critical speed for PM peak hour and weekly non peak hour. It is suggested to use 25 km/h as the critical speed for AM peak hour and night non peak hour. As for the collector road, it is suggested to use 20 km/h as the critical speed for PM peak hour and weekly non peak hour. It is suggested to use 30 km/h as the critical speed for AM peak hour and night non peak hour. CONCLUSIONS : It is meaningful from a methodological point of view that it is possible to make a reasonable comparative analysis on the signal intersection pre-post analysis when the signal operation DB is renewed by breaking the existing traffic signal operation evaluation method.

• Journal of Mechanical Science and Technology
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• 제15권7호
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• pp.1002-1012
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• 2001

The work reported here is an extensive study of tendon response to multiple cyclic tests including 3% constant peak strain level test (A-type test), 3% constant peak strain level test with two rest periods (B-type test), and 3∼4% different peak strain level test (C-type test). A sufficient number of specimens were tested at each type of the test to statistically evaluate many changes in response during testing and differences in response between each type of the test. In cyclic tests, there were decreses (relaxations) in the peak stresses and hysteresis, increases in the slack strains, and during lower peak strain level (3%) cyclic block after higher peak strain level (4%) cyclic block in the C-type tests. Considering the results of this study and those of the other study of multiple cyclic tests with rest periods by Hubbard and Chun, 1985, recovery phenomena during the rest periods occurred predominantly at the beginning of the rest periods. Consistently in both studies, the effects of rest periods were small and transient compared to the effects of the cyclic extensions. The recovery with cycles at lower peak strain level (3%) after higher peak strain level (4%) in the C-type test has not been previously documented. This recovery seems to be a natural phenomena in tissue behavior so that collagenous structures recover during periods of decreased demand.

• 전기학회논문지
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• 제56권2호
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• pp.436-441
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• 2007

Background: As patients are positioned at insulated bed and practitioner are positioned at insulated floor or shoes, it could be a cause of lessening effect in acupuncture practice. We investigated how Ground connection could influence on the electrical meridian potential between practitioner and patient during acupuncture practice. Method: We treated 30 normal healthy subjects with acupuncture and measured changes in the electrical potential between the stomach meridian points ST-39 and ST-37 in response to light touch after insertion of a needle at ST-36. At first, we stimulated needle and measured electrical potentials for non ground, patient ground only, practitioner ground only, all ground, respectively. Result: All ground subject elicited positive mean potential $44.6{\pm}19.2{\mu}V$ and showed $181.4{\pm}59.7{\mu}V$ peak to peak potential. practitioner ground only showed negative mean potential $-51.5{\pm}9.3{\mu}V\;and\;367.4{\pm}27.8{\mu}V$ of peak to peak potential. Patient ground only revealed no mean potential as $2.9{\pm}1.3{\mu}V,\;16.4{\pm}11.9{\mu}V$ of peak to peak potential. All ground showed no mean potential as $1.6{\pm}0.7{\mu}V,\;3.3{\pm}1.9{\mu}V$ of peak to peak potential. respectively.