• 한국해양학회지
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• 제19권2호
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• pp.210-216
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• 1984

5년간의 시간별 풍속 자료를 이용하여 연안 표층풍의 일변화가 분석되었다. 특히 내륙으로 부는 바람 (onshore flow)이 지배적인 계절에는 야간 최대풍의 최대 출현 빈도가 자정에 나타났다. 연평균 남풍 계열을 갖는 야간 최대풍은 북풍 계열 보다 약 3배이상의 출현을 보여준다. 중림의 대기 안정도가 연안에 지배적이므로 바람이 해양에서 내륙으로 불 경우는 (offshore flow) 상승된 전선역전층과 지표역전층에 의해 형성된 전단력(shear flow)이 연안경계층으로 전이되어 야간 연안 최대표층풍이 형성된다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2002년도 전력전자학술대회 논문집
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• pp.719-722
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• 2002

기저부하조성 및 부하율 향상을 위한 심야전력요금제도의 정착으로 최근 심야전력축열기기의 보급이 활성화되고 있다. 그러나 모든 심야전력축열기기들이 심야요금개시시간대인 2f시경에 동시에 가동됨에 따라 23시경에 심야전력 부하가 최대에 이르러 전력피크가 발생하여 한전의 수요관리에 큰 어려움을 주고 있다 따라서 이 피크 부하를 심야전력 공급시간대의 저 부하시간대로 분산시킬 수 있는 심야전력기기 공급시간을 제어하는 통전제어장치가 필요하게 되었으며, 이미 축열식전기보일러와 축열식전기온수기에는 개발 보급되고 있는 실정이다. 이 논문에서는 다른 심야전력축열기기와는 달리 자연방열의 바닥축열난방방식인 축열식전기온돌의 통전제어장치 알고리즘을 실증실험을 통해서 검증하였다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 추계학술대회 논문집
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• pp.349-352
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• 2008

The most concerning issue in these days is the energy crisis by increasing threat of global warming and depletion of natural resources. In the situations, the Plug-in Hybrid Electric Vehicle (PHEV) is drawing attention from many countries for the next generation's car which has higher fuel efficiency and lower environmental impact. This paper presents simulation results about the limit capacity of central power-grid which doesn't have enough surplus electric power for charging PHEVs. Therefore, this paper also presents a smart charging system that can charge the PHEVs with a function of distributing demands of charging. The smart charging system is an agent facility between the government and consumer, which can recommend the best time to charge the battery of PHEVs by the lowest energy cost. This function of choosing time-slots is the technical system for the government which wants to control the consumption rate of electric power for PHEVs. Finally, this paper presents the economic feasibility of PHEVs from the two kinds of price system, midnight electric price and home electric price.

• 한국태양에너지학회 논문집
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• 제28권1호
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• pp.65-74
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• 2008

In this study, dynamic characteristics analysis of AC system is investigated using a cool thermal storage system. A analysing program for cool thermal storage AC system is developed. The performances are studied by several variables and dynamic characteristics. Comparing the result at conventional operation condition with that at the condition using ice storage system, this study showed the effects of the sub cooled degree, superheated degree, efficiency of compressor and evaporating temperature. At the condition using thermal storage system, the thermal storage process was operated during midnight being not needed the cooling of the AC unit through the continuous running of the condenser. The refrigerant was sub-cooled using stored energy after being discharged from the air source condenser during the daytime. The COP was increased owing to the sub-cooling of refrigerant during daytime, thus the power consumption was effectively decreased.

• 천문학회지
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• 제22권2호
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• pp.141-160
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• 1989

In order to derive time dependence of the atmospheric diffuse light, which consists of the airglow continuum emission and diffusely scattered radiations of the intergrated starlight, the diffuse Galactic light, and the zodiacal light, we have analyzed the meridian scan observations of the sky brightness at $5,080\;{\AA}$ and $5,300\;{\AA}$. Amplitude of the time-variation becomes larger for lower elevation, and maximum amplitude is found to be about $50\;S_{10}(V)_{G2V}$ at elevation $10^{\circ}$. The atmospheric diffuse radiation attains maximum brightness at around midnight, and afterward it decreases slowly with time. The time-variations for the two wavelengths are similar to each other. The observed brightness distribution of the diffuse light along the zenith distance is fitted to an empirical relation of two parameters. By making the two parameters time-dependent, we describe the spatial and time variations of the atmospheric diffuse light. This enables us to make time dependent correction for the atmospheric diffuse component in the reduction of zodiacal light brightness.

• 천문학논총
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• 제11권1호
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• pp.197-220
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• 1996

The climatological characteristics at the Choejung-san site were statistically analyzed using monthly normals for the various meteorological elements at Taegu meteorological station for 30 years from January 1960 to December 1990. Various synoptic weather conditions were classified by the estimated geostrophic wind speeds and direction determined using the 850 hPa geopotential height field for 10 years from December 1980 to November 1989. Also the analysis of number of clear days were monthly and seasonally performed using the satellite infrared image data which were obtained from GMS 5 for 5 years from December 1990 to November 1995. The results reveal that the meteorological environments of astronomical observation at Choejung-san site were very good conditions during three hours after midnight except for summer season.

• 한국환경과학회지
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• 제2권2호
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• pp.103-113
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• 1993

The land and sea breeze over the Pusan coastal area is studied by three dimensional mesoscale numerical model. According to the results of the simulation experiments, both Pusan areas and Kimhae areas, the sea breeze began at 0800LST and the strongest at 1500LST and then at 1800LST. After midnight, the sea breeze changed about the land breeze and become weaker than that of the sea breeze in the daytime. Comparisons between calculations and observations showed that the characteristics of diurnal variation and v-component of the wind velocity relatively is similar to the Pusan areas. On the Kimhae areas, however, observations showed time lag which compared to the results of simulation experiments in the velocity of sea breeze and diurnal variation. From the above results, comparisons between calculations and observations is much more similar to the coastal areas than on the inland area.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1985년도 하계학술회의논문집
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• pp.144-147
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• 1985

In electricity industry, the improvement of load factor by flattening of load has been considered to be more important than any other tasks and has received wide concern and interest. Especially while annual peak load had occured early evening in winter during past decades, but we found the trend has changed so that annual peak load occured during the daytime in summer since1981 The useful practicing methods of this load management ale as follows; 1. Inducing of midnight load by thermal storage water heating 2. Seasonal differential rates. 3. Revising the peak load priceing (Time-of -use) It seems hard to expect that load research can be carried out in a short time, and we all have to exert outselves continuously to provide efficient load management method without wasting resources.

• 한국항해학회지
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• 제23권4호
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• pp.89-96
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• 1999

This paper is concerned with the experimental analysis of EOW(End-of-Week) rollover. The GPS EOW Rollover happens every 20 years. Because GPS time, counted in weeks, started counting Jan. 6, 1980, the GPS week will rollover from week 1023 to 0000 at midnight between Aug. 21 and 22. This is significant because it is the first EOW rollover since the GPS constellation was established and it could be interpreted as an invalid date in receivers that were not designed to meet GPS specification. We analyzed GPS data of the noncompliant receivers and the compliant receiver. It was concluded that all receivers had not serious problems during or after the rollover.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2010년도 한국우주과학회보 제19권1호
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• pp.41.1-41.1
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• 2010

A bipolar magnetic field perturbation in the meridional plane was observed when the Polar spacecraft crossed the plasmapause near the midnight, which was identified by a clear jump in density and temperature, from the plasmasheet to the plasmasphere. The bipolar variation shows a negative-then-positive polarity. To examine the bipolar magnetic field perturbation at the plasmapause, we assume one-dimensional model with physical quantities varying along a direction normal to the plasmapause and employ two-fluid approach for the tangential plasmapause. That is, the magnetic fields on both sides are parallel. Considering Ampere's law and pressure balance relation, we have a perturbed magnetic field, which is consistent with the observation at the plasmapause.