• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제3권9호
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• pp.273-278
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• 2014

최근 전력의 수요공급 불균형으로 전력사용 피크시간대의 전력사용 강제 제한이 불가피하다. 따라서, 본 논문에서는, 피크전력이 발생하지 않는 시간대의 전기를 저장하고 전력부족이 예상되는 피크전력 시간대에는 저장전력을 공급하는 병렬운전 기기의 회로를 설계하는데 있다. 이 회로설계를 통하여, PRS의 핵심기능인 상용전원과 인버터 발생전원의 병렬연결 운용으로, 상용전원의 피크치 전력을 조절할 수 있었다. 또한 효율을 높이기 위하여 Transless Power Circuit DC-AC 인버터를 개발하였다. 더 나아가, 가변임피던스 제어를 적용하여 무정전 전원장치의 저장전력을 상용전원과 연계함으로써, 기존의 무정전 전원장치에서 구현을 못하고 있는 저장전력 사용시간을 획기적으로 늘릴 수 있는 기술구현 가능성을 입증하였다.

• Journal of Electrical Engineering and Technology
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• 제12권2호
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• pp.981-987
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• 2017

In this paper, we estimate the economic benefits of Energy Storage Systems (ESSs) for peak load shaving in an urban railway substation using the annual cost. The annual investment cost of ESSs is estimated using Net Present Value (NPV) and compared with the cost reduction of electricity by the ESS. The optimal capacities of the battery and Power Converting System (PCS) are determined for peak load shaving. The optimal capacity of the ESS and the peak load shaving is determined to maximize the profit by the ESS. The proposed method was applied to real load data in an urban railway substation, and the results show that electric power costs can be reduced. Other aspects of the ESS, such as the lifetime and unit price of the battery, are also investigated economically.

• 물과 미래
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• 제26권2호
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• pp.59-65
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• 1993

본 연구에서는 한강유역의 7개 수위관측소 지점에 기록된 총 198개의 홍수사상예 대한 일평균유량자료와 참두홍수량 자료를 Fuller방법 및 Sangal방법과 유사한 방법으로 상관시켜, 홍수기간별 일평규유량 자료로부터 그 기간동안의 참두홍수량을 산정할 수 있는 방법을 연구 분석하였다. Sangal 방법에 의한 참두홍수량의 산정결과는 실측치와 상당히 높은 상관성을 보였으며, 한강유역 전반에 걸쳐 제안된 지역화 기법은 유역내 수위관측소 지점의 홍수사상별 일평균유량으로부터 참두홍수량을 산정하는데 효과적으로 사용될 수 있을 것이다.

• 생명과학회지
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• 제8권4호
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• pp.373-380
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• 1998

A considerable change observed in X-ray diffraction during the muscle contraction was that the movement of myosin head and conformational change of contractile monecules were occurred in the muscle contraction. Time slice requires tension peak after the onset of stimulation and the height of tension peak depends on the number of twitch cycle. The intensity of I$_{11}$, I$_{10}$, 143${\AA}$ reflection is measured with 5ms time resolution and is recorded in isometric tension. The peak height of I$_{11}$ and 143${\AA}$ intensity is changed after the onset of a stimulation I$_{i}$, and the length of twitch is shortened by successive twitches in the case of stimulation TI$_{i}$. On the other hand, the peak height of I$_{11}$ and 215${\AA}$ intensity starts to decrease at the 1st twitch and remains constant at low peak hight without appreciable recovery during the contraction term. In the case of uccessive twitch stimulation, the myosin heads of muscle are once moved from their resting position and never returned to their initial position.

• 한국재료학회지
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• 제12권8호
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• pp.613-616
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• 2002

The polarization properties of $BaTiO_3$ were investigated by using thermally stimulated depolarization current (TSDC) technique. Two peaks were observed at about 400 K (peak A) and 435 K (peak B) from TSDC spectra obtained from the temperature range of 280-500 K. Peak A shows a sharp decrease of TSDC due to extinction of spontaneous polarization above the phase transition temperature of $BaTiO_3$. The values of activation energy of peak A and peak B were calculated to be 0.70 eV and 0.87 eV respectively. From the results of TSDC measurement with a variation of polarizing electric field strength, we found that saturation of total current of TSDC was started from 3kV/cm. However, the amount of total current of TSDC was not affected by the variation of polarizing time.

• Nuclear Engineering and Technology
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• 제52권7호
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• pp.1486-1494
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• 2020

To evaluate transport-induced cladding embrittlement after interim-dry storage, ring compression tests were carried out at room temperature(RT) and 135 ℃. The ring compression test specimens were prepared by simulating the interim-dry storage conditions that include four peak cladding temperatures of 250, 300, 350 and 400 ℃, two tensile hoop stresses of 80 and 100 MPa, two hydrogen contents of 250 and 500 wt.ppm-H and a cooling rate of 0.3 ℃/min. Radial hydride fractions of the ring specimens vary depending on those interim-dry storage conditions. The RT compression tests generated lower offset strains than the 135 ℃ ones. In addition, the RT and 135 ℃ compression tests indicate that a higher peak cladding temperature, a higher tensile hoop stress and the lower hydrogen content generated a lower offset strain. Based on the embrittlement criterion of 2.0% offset strain, an allowable peak temperature during the interim-dry storage may be proposed to be less than 350 ℃ under the tensile hoop stress of 80 MPa at the terminal cool-down temperature of 135 ℃.

• 전기학회논문지
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• 제63권12호
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• pp.1752-1758
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• 2014

This paper evaluates economic benefits of ESS (Energy Storage System) for peak load shaving in the substation of urban railway. For this purpose, the method to determine capacities of ESS and PCS (Power Conditioning System) for peak load shaving is proposed. Then the economic benefits of those devices are evaluated using net present value method. The proposed methods are applied to actual measurements of loads in the substation of urban railway. The results show that electric power costs can be reduced and the economic benefits of ESS for peak load shaving mainly depends on the price of battery.

• Mass Spectrometry Letters
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• 제11권1호
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• pp.6-9
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• 2020

Matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) analysis of ionic liquid matrices (ILMs) prepared using pyridine and dihydroxybenzoic acid (DHB), such as 2,3-DHB and 2,5-DHB, displayed an unconventional peak at m/z 232.0, which was regarded as [DHB+pyridine-H]⁺. The peak at m/z 232.0 was not observed from other ILMs prepared using other DHB isomers, such as 2,4-DHB, 2,6-DHB, 3,4-DHB, and 3,5-DHB. Two requirements to observe the peak at m/z 232.0 in a DHB/pyridine ILM are suggested. First, carboxyl and hydroxyl groups must be located ortho to each other. Second, the secondary hydroxyl group must be located at a carbon with a high electron density. Based on these two requirements, a potential mechanism for the generation of the peak at m/z 232.0 is suggested.

• 한국연초학회지
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• 제5권1호
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• pp.11-17
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• 1983

The tobacco moth, Ephestia elutella Hubner (Lepidoptera: Pyralididae), was first reported one of the serious of stored tobacco in Korea in 1939 (8). In recent years, tobacco moth lavae were observed infesting in all of the tobacco storage warehouses in this Country. Adults of the tobacco moth for the seasonal occurrence were studied in the three and four regions in 1981 and 1982, respectively. This species was caught from early May to late October in all regions for both years. In 1981, the first emergence peak was in late May to late at Andong, early June at Suweon and the second one in middle August in both regions. In 1982, on the other hand, there were three peak times, late May and July, and middle September. But the relate size of the peaks was different in two years; the second peak showed about 66% of the total number of tobacco moths captured in the whole year in 1981 at Suweon and 59% of those at Andong, while the first peak had 32% at Suweon and 57% at Shintanjin in 1982. This difference in relative peak sizes was discussed.

• ETRI Journal
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• 제34권2호
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• pp.268-271
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• 2012

The high peak-to-average power is one of the main drawbacks in OFDM systems. This letter proposes a partial shift mapping (PSM) method for peak power reduction in OFDM systems. By utilizing the properties of the discrete Fourier transform, the proposed method generates a set of candidate signals without additional complex multiplication and selects the one with minimum peak power for transmission. Analyses and simulations confirm that the PSM method achieves satisfactory peak power reduction performance and low complexity compared with other kindred methods, for example, selected mapping and partial transmit sequences.