• 설비공학논문집
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• 제22권10호
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• pp.719-726
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• 2010

In this paper, the appropriate thermal storage time of an air-conditioning system with slab thermal storage was considered by use of summer measurement values. Two standards of heat extraction rate and criterion function were established as the standard that evaluates appropriateness. When heat extraction rate was a standard, zero hour and seven hours were obtained as appropriate thermal storage time, in the case of evaluation by energy consumption and running cost individually. Also, when criterion function was a standard, the difference between energy consumption and running cost was small, it was because the weight function to room air temperature deviation was much bigger than heat extraction rate.

• 농업과학연구
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• 제45권3호
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• pp.355-363
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• 2018

This study was conducted to investigate suitable rice cultivars for various rice based cropping systems in a paddy field in the Yeongnam plain area. Thirteen rice cultivars (5 early, 3 medium and 5 mid-late maturing cultivars) and three transplanting dates (June 5, June 25 and July 5) were evaluated in this study. The mid-late and early maturing cultivars for the July 5 and June 25 transplanting headed before August 30 which is the safe heading date in the Yeongnam plain area, ranging from Aug. 26 - 28 and Aug. 18 - 23, respectively. The safe harvest time of rice for double and triple cropping systems should be before the middle of October for the cultivation of the succeeding winter crops. The rice yield was the highest for the June 5 transplanting regardless of the rice cultivars, and it gradually decreased as the transplanting date was delayed from June 5 to July 5 due to a decrease in the spikelet numbers per panicle number and in the ripened grain rate. In contrast, the other yield parameters that include the panicle number per $m^2$, the 1,000-brown rice weight, and the ripened grain ratio were not significantly affected. The result indicates that based on the milled rice, heading time and harvest time, a medium maturing cultivar (Haiami and Samdeog) would be applicable to a winter barley/wheat, garlic/onion-summer rice double cropping, while a mid-late cultivar (Saeilmi, Saenuri and Hyunpoom) would be suitable for a spring potato/waxy corn-summer rice double cropping in the Yeongnam plain area. On the other hand, an early maturing cultivar (Unkwang, Jokwang and Haedamssal) would be preferable for a triple cropping because of the short growth period of rice.

• Asian-Australasian Journal of Animal Sciences
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• 제22권6호
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• pp.774-780
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• 2009

The objectives of this study were to test the efficacy of induction of estrus and determine the timing of ovulation in relation to preovulatory LH and estrogen surges in cycling Murrah buffaloes subjected to Heatsynch protocol (GnRH-$PGF_2{\alpha}$-Estradiol benzoate). In experiment 1, the buffaloes (n = 10) were treated with Heatsynch protocol and observed for estrus and ovulation. In experiment 2 and 3, 30 cycling Murrah buffaloes were used to investigate the efficacy of Heatsynch protocol in terms of conception rates in summer (experiment 2) and winter (experiment 3) seasons. Fixed time A.I. was performed in all the buffaloes at 48 and 60 h post-estradiol benzoate (EB) injection. All buffaloes responded to the Heatsynch protocol with expression of estrus for which ovulations were induced in 8 buffaloes (80%). Mean time interval from the EB injection to ovulation was 50.0${\pm}$2.0 h (range 44.0 to 60.0 h). The interval from the end of LH surge to ovulation was 18.5${\pm}$2.47 h (range 8 to 26 h). The interval from end of estrogen surge to ovulation was 26.75 ${\pm}$2.07 h (range 22 to 36 h). Mean LH peak after EB injection occurred at 20.81${\pm}$1.61 h (range 14 to 28 h) and mean estrogen peak after EB injection occurred at 9.62${\pm}$1.03 h (range 7 to 16 h). Hence, the mean estrogen peak preceded the mean LH peak by 11 h. It was observed that the percentage of conceptions to total number of estruses for control buffaloes was 18 and 30 in summer and winter, respectively, whereas it increased to 26 and 40 in Heatsynch treated buffaloes in respective seasons. The results suggest the possibility of using Heatsynch treatment followed by fixed time A.I. in buffaloes for fertility improvement, especially since the incidence of silent heat in buffaloes is very high.

• 원예과학기술지
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• 제35권4호
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• pp.418-430
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• 2017

The objective of this study was to understand the combined effect of shading treatment and harvest time on pungency, ascorbic acid content, market-quality pepper yield, and photosynthetic activity in a yellow 'Star Flame' and 'Fire Flame' F1 hybrid pepper cultivar (Capsicum annuum). Plants were cultivated in a greenhouse under white, red, and green shading nets and compared to those grown under unshaded control conditions. The ascorbic acid and pungency parameters were analyzed by high-performance liquid chromatographic methods. Ascorbic acid, a compound of high nutritive value in pepper, was highest in fruits gathered during the first summer harvest in both hybrids. The ascorbic acid content was found to be further increased in fruits from plants grown under white net shading in both 'Star Flame' and 'Fire Flame'. Total capsaicinoid contents in 'Star Flame' were influenced by the interaction of shading treatment and harvest time (p = 0.004), with the lowest amounts ($241.2-251.5mg{\cdot}kg^{-1}$ fresh weight) resulting from white and red shading treatments at the early autumn harvest. In 'Fire Flame', both shading treatment (p = 0.009) and harvest time (p < 0.001) affected total capsaicinoid contents. We observed significantly higher total capsaicinoid contents in control fruits compared to that resulting from red and green shading treatments at the second harvest, and that resulting from red shading treatment at the third harvest. Analysis of photosynthetic activity revealed a significant and negative correlation between Fv/Fm values and total capsaicinoid contents in both hybrids (p < 0.001). Based on the obtained results, the harvest of peppers during summer should be promoted to produce fruits with high pungency.

• 한국산학기술학회논문지
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• 제10권2호
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• pp.230-236
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• 2009

본 논문에서는 신재생 에너지 활용을 위한 그늘막 형태의 연계 계통형 태양광 발전 시스템을 제안한다. 제안하는 발전 시스템은 성하기에 해수욕장을 찾는 피서객들에게 상용전원과 연계 계통하여 최대 전력 수요를 충족시킬 뿐 만 아니라 그늘막으로서의 기능을 갖도록 설계하였다. 태양전지에서 생성된 전기를 낮 시간 동안 축전지에 충전하면 이를 야간에 전등이나 선풍기등에 이용할 수 있다. 축전지를 충전할 때 축전지의 성능을 유지하려면 충방전컨트롤러가 필요하다. 제안하는 축전지 충방전 컨트롤러는 고성능 마이크로프로세서를 사용하여 정확하고 안정된 동작을 하도록 설계하였고 사용자의 편의를 위해 디지털 표시기 및 축전지 교체시기 경보장치등을 갖추고 있다. 제안하는 발전 시스템을 영동 지역 해수욕장에 설치하고 실험을 통하여 전력 생산능력과 발전 성능을 확인하였다.

• 한국의류학회지
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• 제33권12호
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• pp.1941-1955
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• 2009

이 연구의 주요 목적은 한국과 일본의 스트리트패션을 비교하고, 상대국 패션에 대한 영향을 살펴보고자 하였다. 각국의 두 패션잡지에서 2003년 춘하 시즌부터 2007/08 추동시즌까지의 여성 스트리트패션 자료를 수집하였다. 최종 2211 사진이 분석에 사용되었다. 양국 스트리트패션의 종단적 변화는 풀코디네이션 경향, 다양한 색상과 문양 사용의 증가, 세계적인 트렌드 영향과 같은 공통점을 보여주었다. 의복 아이템의 수용에서는 한국과 일본의 시간차이가 나타나서 일본 스트리트패션이 한국 스트리트패션에 영향을 끼쳤음을 시사하였다. 그러나 의복 수용의 시간차는 2006년 이후로 나타나지 않았으며, 양국의 스트리트패션은 동시에 변화하고 있었다. 추동시즌보다 춘하시즌에서 더 많은 유사성이 발견되었다. 또한, 액세서리에서도 의복 아이템에서보다 더 많은 유사성이 나타났으며, 액세서리 수용에서는 시간차이는 발견되지 않았다.

• 자원ㆍ환경경제연구
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• 제17권2호
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• pp.213-233
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• 2008

현재 한국전력이 시행하고 있는 하절기 부하관리 프로그램의 성과를 평가함에 있어, 해당 프로그램이 시행되지 않은 상태의 수요가 확인되지 않은 상태에서 단순 합산한 것임에도 불구하고 이 크기의 전체를 수요관리 효과로 집계하고 있다. 본 연구는 이러한 문제에 대해, 이들 프로그램 중에서 가장 비중이 큰 두 가지 프로그램-휴가보수기간 조정제도와 자율절전제도-이 하절기 피크 시간대인 오후 2시~4시 사이의 전력수요에 얼마나 큰 영향을 미치는지를 계량적으로 분석한다. 연구 결과에 의하면 이들 두 제도의 효과를 따로 분석할 경우에는 휴가보수기간 조정제도는 보된 실적치 1kW당 실제로 피크 시간대 전력수요가 시간당 0.53kW만큼 감소하였으며, 자율절전의 경우 실적치 1kW당 피크 시간대 전력수요는 시간당 0.57kwh만큼 감소하였다. 이들 결과는 이들 수요관리 프로그램들이 실제로 피크부하를 감소시키는 데에 상당한 효과가 있음을 보여 준다. 그러나 이 두 제도의 효과를 한꺼번에 분석하는 경우에는 각각의 효과가 크게 약해짐을 볼 수 있었다.

• 한국물환경학회지
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• 제33권6호
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• pp.650-660
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• 2017

In this study, pollutant emission characteristics by water damage period analyzed 11 items (water temperature, pH, DO, EC, BOD, COD, TOC, SS, T-N, T-P and flow) with load duration curve, time series load curve and factor analysis for three years (2014-2016). Load duration curve is applied to judge the level of impaired waterbody and estimate impaired level by pollutants such as BOD and T-P in this study depending on variation of stream flow. Water quality standard exceeded the flow of mid-range and low-range by flow condition evaluation using load duration curve. This watershed was influenced by point source more than non-point source. Cumulative excess rate of BOD and T-P kept water quality standard for all seasons (spring, summer, autumn and winter) except BOD 59% in spring. Water quality changes were influenced by pollutants of basic environmental treatment facilities and agricultural areas during spring and summer. Results of factor analysis were classified commonly first factor (BOD, COD, and TOC) and second factor (flow, water temperature and SS). Therefore, effects of artificial pollutants and maintenance water must be controlled seasonally and reduced relative to water damage caused by point pollution sources with effluent standard strengthened in the target watershed.

• 수산해양기술연구
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• 제27권3호
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• pp.170-177
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• 1991

수영만으로 유입되는 수영강수에 의한 하구의 물리적인 특성을 밝히기 위하여 1989년 5월부터 1990년 4월까지 월별로 관측된 염분 자료와 Officer(1977)가 제안한 식을 이용하여 담수량 및 그 체류 시간을 계산하였다. 그 결과, 수평적으로는 수영만의 동백섬을 기준으로 수영강과 접하고 있는 만 안쪽으로 저염화가 강하게 나타나고 연직적으로는 강 혼합과 부분 혼합의 특징이 나타났다. 그리고 수영강을 중심으로 광안리 쪽이 해운대쪽보다 높은 담수율을 나타내었다. 그리고 거리에 따른 담수율의 분포 특성을 알아보기 위하여 수영강에서 외해쪽으로 6개 정점에서 각각 계산한 담수율을 각각의 최대치로 나누어 계절별로 정규화한 결과 담수율이 지수함수적으로 감소하였다. 추계에는 정점C3를 기준으로 감소율이 다른 계절에 비해 현저히 떨어졌는데, 이것은 성층에 기인한 것으로 보인다. 그리고 앞에서 구한 담수율을 이용하여 수영강에서 유입되는 담수의 체류시간을 계산한 결과, 약 1.3일인 하계를 제외하고 나머지 계절은 약 10~15일 정도임이 밝혀져 하계가 다른 계절이 비하여 담수의 순환이 빠름을 알 수 있었다.

• 천문학논총
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• 제38권1호
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• pp.1-12
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• 2023

Numerous Sundials were fabricated during the reign of King Sejong of the Joseon Dynasty. One among them is Jeongnam-Ilgu (the Fixing-South Sundial), where the time can be measured after setting up the suitable meridian line without a compass. We reconstructed the new Jeongnam-Ilgu model based on the records of 'Description of Making the Royal Observatory Ganui (簡儀臺記)' in the Veritable Record of King Sejong. Jeongnam-Ilgu has a summer solstice half-ring under a horizontal ring which is fixed to two pillars in the north and south, and in which a declination ring rotates around the polar axis. In our model, the polar axis matches the altitude of Hanyang (that is Seoul). There are two merits if the model is designed to install the polar axis in the way that enters both the north and south poles and rotates in them: One is that it is possible to fix the polar axis to the declination ring together with the cross-strut. The other is that a twig for hanging weights can be protruded on the North Pole. The declination ring is supposed to be 178 mm in diameter and is carved on the scale of the celestial-circumference degrees on the ring's surface, where a degree scale can be divided into four equal parts through the diagonal lines. In addition, the time's graduation that is drawn on the summer solstice half-ring makes it possible to measure the daytime throughout the year. An observational property of Jeongnam-Ilgu is that a solar image can be obtained using a pin-hole. The position cast by the solar image between hour circles makes a time measurement. We hope our study will contribute to the restoration of Jeongnam-Ilgu.