• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.10
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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.

• Korean Journal of Agricultural Science
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• v.45 no.3
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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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• v.22 no.6
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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.

• Horticultural Science & Technology
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• v.35 no.4
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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.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.2
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• pp.230-236
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• 2009

In this paper, in order to utilize new and renewable energy a grid-connected parasol-type solar power generation system is presented. The proposed power system combining with commercial electric power system is designed to meet the need fur maximum power consumption and parasols for the people staying at beach during hot summer. Solar electric power can be charged in rechargeable batteries during day time and used to provide charged electric power to loads like lamps and fans during night time, A battery charge-discharge controller is required for the good performance of batteries to be charged. The presented battery controller is designed based on high performance microprocessor for precise charge-discharge operations. An alarm circuit to give notice of battery exchange time and other convenient functions are installed in the system. We implemented the proposed solar power generation system at East Sea beach during peak summer season to verify its productivity and performance by experiments.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.12
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• pp.1941-1955
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• 2009

This study compares street fashions in Korea and Japan to investigate possible interactive influences. Women's street fashion data were obtained from two magazines in each country from the 2003 spring/summer season to the 2007/08 fall/winter season. A total of 2211 pictures were used in the final analysis. The longitudinal changes in street fashion showed a similar trend toward full coordination, the increased use of colors and prints, and the influences of global fashion trends in both countries. The results showed a time lag between the two countries in the adoption of some clothing items that suggest the influence of Japanese street fashion in Korea. The time lag has diminished and since 2006, street fashion has simultaneously progressed under the mutual and common influences of global trends. There are more fashion similarities in the spring/summer than in fall/winter. The adoption of fashion accessories did not show any sign of a time lag and many accessories became popular during the same season.

• Environmental and Resource Economics Review
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• v.17 no.2
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• pp.213-233
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• 2008

In this paper, we estimate the effects of the two most important means of summer time demand side management in Korean power market: adjustment of vacation or repair timing and the voluntary saving program. We use regression analyses to estimate how effective these two programs are in reducing the peak time demand during the summer. Our results show that adjustment of vacation or repair timing actually reduces the daily peak demand by 0.53 kWh per one kWh reported reduction calculated from the agreements between Kepco and the users. The voluntary saving program reduces the daily peak by 0.57 kWh per one kWh reported reduction calculated from the agreements between Kepco and the users. However, when we include these two effects in the same regression model, their respective estimated effects become much weaker.

• Journal of Korean Society on Water Environment
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• v.33 no.6
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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.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.27 no.3
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• pp.170-177
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• 1991

This paper presents the seasonal variation of distribution and flushing time of the fresh water in Suyoung Bay based on the monthly observation from May 1989 through April 1990 and Pusan City Report of Suyoung Bay. Most of Suyoung river water was trapped inside of the bay west of the Dong-Baek Island located. Low salinity water lies dominantly on the right hand side of the Suyong river. Salinity structure of the bay is the well mixed type in summer and the partially mixed type in other season. The fresh water fraction varied in an exponetial manner from unity at the head of bay toward a value of zero at the its mouth. The calculated average flushing time during a year was about 10-15days. About 1.5 days was in summer because the strong fresh water discharge from the river was dominated in the bay.

• Publications of The Korean Astronomical Society
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• v.38 no.1
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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.