• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.1
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• pp.263-270
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• 2011

In this study, the performance of Poly-Naphthalene Sulfonate (PNS) type-admixture used widely in South Korea and Polycarboxilic type-admixture(i.e., WF2000) developed in the J company of the domestic, for precast concrete products produced in the factories, was evaluated. With the 20% reduced usage of WF2000 compared to PNS type-admixture, workability was considerably improved due to high water-reducing ratio, accelerating effect of concrete setting and accelerant dispersant action, which the product has, under the high temperature. In addition, the development of initial and long-term strengths of PHC plies was predominant. For WF2000, it is also possible to correspond with the change of original materials and environmental conditions since the control of water-reducing and supporting forces is feasible. Accordingly, it was noted that WF2000 is superior for deterioration of production & workability and bad casting problems in summer and the solution of initial strength reduction problem due to the delay of setting in winter.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.1
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• pp.57-66
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• 2013

The purpose of this study was to investigate the effects of shifts in sowing time on the ecological responses, growth and yields of major soybean cultivars in a southern region of South Korea. Experiments were carried out in Naju, Jeonnam Province (latitude $35^{\circ}$ 04'N, longitude $126^{\circ}$ 54'E) for three years from 2008 to 2010. The test cultivars included Saeol-kong and Tawon-kong of the summer type, Taekwang-kong and Pungsannamul-kong, and Cheongja3 of the autumn type. Sowing took place on May 15 and 30, June 15 and 30, and July 15 of each year. Of the summer type soybean cultivars, Saeol-kong showed a smaller curtailment in days from sowing to flowering, days from flowering to maturity, and days from sowing to maturity according to sowing time postponement than Tawon-kong. Of the autumn type soybean cultivars, Taekwang-kong exhibited a lower photoperiodic response in reproductive growth period than Pungsannamul-kong and Cheongja3, both of which recorded higher level photoperiodic responses in vegetative growth stages and reproductive growth periods than other test cultivars, with the former exhibiting higher levels than the latter. Most of the test cultivars tended to decrease in stem length, node numbers of the main stem, and stem diameter according to postponed sowing time, but there were no significant differences in stem length and node numbers of the main stem of the Saeol-kong cultivar. Differences in sowing times did not affect the first setting pod node order of Saeol-kong and Tawon-kong summer type cultivars of internode lengths of all of the test cultivars. All of the test cultivars tended to show decreases in pod number per plant due to postponement of sowing time except for the Saeol-kong cultivar. The variation was more prominent in small grain cultivars such as Tawon-kong and Pungsannamul-kong with the latter autumn type cultivar showing especially large variation. Yields were the greatest for the Tawon-kong, Taekwang-kong, and Pungsannamul-kong cultivars sown on May 30 and Cheongja3 sown on May 30 and June 15. There were no significant differences in the yields of Saeol-kong for different sowing times from May 30 to July 15, with the yields lowest for the batch sown on May 15.

• Horticultural Science & Technology
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• v.31 no.3
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• pp.388-392
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• 2013

A spray chrysanthemum cultivar 'Green Candy' was released by National Institute of Horticultural & Herbal Science, Rural Development Administration, in 2009. The cross between 'Yoko Ono', a spray chrysanthemum cultivar with light yellowish-green double type, and 'Green Bird', a spray chrysanthemum cultivar with vigorous and green double type, was made in Suwon in 2006. After the evaluation of the characteristics under shade culture in summer and retarding culture in spring and consecutive selection from 2007 to 2009, 'Green Candy' was selected finality. The natural flowering time of 'Green Candy' is October 28th, and it is possible to flower all year-round by shade and light culture. It has double flower type with green petals. The growth of plant is very vigorous and the color of the petals is stable when the variety is cultivated under high temperature conditions in summer season. The diameter of flower is 4.1 cm. The numbers of flower per stem and petals per flower are 12 and 217, respectively. The days for flowering under the short day treatment are about 58 and its vase life is 18.1 days in autumn season. 'Green Candy' was applied as No. 2010-212 on March 5, 2010 for variety protection and the plant variety protection rights have been registered as No. 3633 on August 2, 2011 at the Korea Seed and Variety Service.

• Horticultural Science & Technology
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• v.30 no.2
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• pp.220-223
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• 2012

A new cultivar $Dendranthema$ $grandiflourm$ 'Dream Water' was developed at Gyeonggi-do Agricultural Research & Extension Services, Korea in 2009. The cultivar 'Dream Water' was initially derived from the cross in 2005 between 'Patra', a spray chrysanthemum cultivar with yellow single type, and 'Ruces', a spray chrysanthemum cultivar with white single type. The cultivar has single type with ivory petals. Trial evaluation was conducted from 2006 to 2009 for selection of this variety, including a shading culture in spring and a retarding culture in summer. The flowering time of 'Dream Water' was October 24th, and year-round flowering is possible by shading or lighting treatment. The diameter of the flower is 56.0 mm. Number of flowers per stem and petals per flower are 11.1 and 26.8, respectively. Its leaf color was green (Green Group 147A) and plant height was 89.7 cm. Days to flowering under the short day treatment is about 54 in spring, and diameter of flower center was 1.4 cm in the summer. The vase life was 16.7 days in autumn and consumer's preference of new spray chrysanthemum is high level than control.

• Horticultural Science & Technology
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• v.31 no.4
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• pp.517-521
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• 2013

A new cultivar Dendranthema grandiflourm 'Dream Round' was developed at Gyeonggi-do Agricultural Research & Extension Services (GARES), Korea in 2010. The variety 'Dream Round' was initially derived from a cross in 2006 between 'Hebo' a seed parent, a spray chrysanthemum cultivar with white anemone type, and 'Samos' as a pollen parent, a spray chrysanthemum variety with white anemone type. The cultivar has anemone type with white petals. Trial evaluation was conducted from 2008 to 2010 for the selection of that cultivar, including a shading culture in spring and a retarding culture in summer. The flowering time of 'Dream Round' was October 24th, and year-round flowering was possible by shading or lighting treatment. The diameter of flower of 'Dream Round' was 34.1 mm. Numbers of flowers per stem and petals per flower of 'Dream Round' were 12.8 and 26.1, respectively. Its leaf color was green (Green Group 147A) and plant height was 92.4 cm. Days to flowering of 'Dream Round' under the short day treatment was about 54 in spring, and diameter of flower of 'Dream Round' was 34.2 mm in the summer. The vase life of 'Dream Round' was 21.7 days in autumn.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.3
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• pp.191-200
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• 2016

The ventilation effect of a ventilation system, which is classified as the forced ventilation and natural ventilation, is predominantly dependent on the combination of air supply and discharge. Perhaps the simplest ventilation is merely supplying the air as it is. However, to improve the indoor working environment during the summer, an air supply that is cooled to some extent has been widely adopted. Recently, a cooling method utilizing the vaporization of water was introduced. In this study, the performance of an evaporation-type air supply unit that was produced by Japan K-company and was installed in a shoe-manufacturing plant in Busan was investigated. The purpose of the experiment was to measure how much the supplied air could be cooled. From this experimental study, we confirmed that the evaporation-type air supply system is efficient, capable of improving the working environment during the summer while minimizing the energy cost.

• Journal of Environmental Science International
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• v.15 no.7
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• pp.643-651
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• 2006

This study investigated the distributive property of micropollutants in sediment around Gwang-yang bay using simultaneous analytical method of 310 chemicals. In the results, the major micropollutants detected were CH type chemicals such as aliphatic, polycyclic compounds, benzenes, and CHN(O) type chemicals aromatic amines, and pesticides. Insecticides of pesticide type were frequently detected at all sampling site. The total concentration of micropollutants were higher in summer than in winter and measured within the range of $ND{\sim}36.50{\mu}g/L$. Also, because of effect of seomjin river, GY6 of all sampling site detected by the highest concentration, GY10 and 11 located in Gwang-yang outside bay were not detected the micropollutants. From the result of this study, we should estimated that the industrial complex located in Gwang-yang inside bay and an inflow of fresh water through the Seomjin river are major pollution sources of Gwang-yang bay.

• Journal of Korean Society for Atmospheric Environment
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• v.8 no.1
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• pp.1-6
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• 1992

Using data measured in 1989, a study on variations of visibility and air pollution observed in Seoul, Chongju and Choopoongryong is carried out. Analysis includes on low visibility (< 10km) and smog occurring in the Metropolitan Seoul. It was observed that number of days of visibility less than 10km during 1989 was 56.7% (207 days) for Seoul, 45.7%(167 days) for Chongju and 5.8% (21 days) for Choopoongryong. Chongju is a medium size city (population : a half million) and Choopoongryong is a rural site. In the urban are as, however, the number of low visibility days was relatively large during the winter but with little seasonal variations. In each month these cities recorded more than 10 days of low visibility. The visibility reduction due to mist, fog and haze been occurred with air pollution. In particular, the reduction in a cold season related with an increase in high concentrations of $SO_x$ and aerosols. This type of low visibility occurring in Seoul is a similar type that is occurring in London, U.K. On the other hand, the visibility reduction during in a warm season is related with high concentrations of NOx and other photochemical precursors. The visibility reduction in Seoul during summer is the same type occurring in Los Angeles, U.S.A.

• Journal of Korean Society of Rural Planning
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• v.1 no.2
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• pp.67-76
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• 1995

The actual condition of farmstead, mainly livestock facility, was surveyed in ChungChongBukDo in order to find out factors and problems of farmstead planning design. From the data collected, a type, plot, size and scope of farmstead, relationship of house and farmstead, topography, climate, proprietor's opinion on them were analyzed or obtained as the basic design criteria for planning: designs. The best type of farmsteads was individual farm having livestock facilities. They were mostly breeding a kind of livestock without their plan and Bone planning at residing area. The south aspect of the facility was extremely much and slope of the land was mostly 15。 below. Wind blows from East-South in summer and winter wind are West-North extremely much. Sun heat was mostly above 6 hours. In the case of collective and composite farmstead, proprietors wanted that a head of cow has 1,000-3,000 pyeong, the area of facility has 1,500-2,000 pyeong, total area of farmstead has 45,000-400,000 pyeong and an estimated expense is 0.2 - 1.5 billion won. Farmstead planning design was proposed through field survey results and contents of'references. Examples of farmstead planning design were composite and concentrated type and existed according to the situation of road(North, South, East, and West).

• Journal of the Korean Solar Energy Society
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• v.31 no.3
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• pp.80-88
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• 2011

Heliostat in the tower type solar thermal power plant is a sun tracking mirror system to reflect the solar energy to the receiver and the optical performance of it affects to the efficiency of whole power plant most significantly. Thus a solid understanding of heliostat's energy concentration characteristics is the most important step in designing of the heliostat field and the whole power plant. The work presented here is the analysis of energy concentration characteristics of heliostat used in 200kW solar thermal power plant, where the receiver located at 43m high in tower has $2{\times}2$m rectangular shape. The heliostat reflective surface is formed by 4 of $1{\times}1$m flat plate mirror facet and the mirror facet is mounted on the spherical frame. The direct normal incident radiation models in vernal equinox, summer solstice, autumnal equinox and winter solstice are first derived from the actually measured data. Then the intercept ratio, heat flux distribution and total energy collected at the receiver for the heliostats located in the various places of the heliostat field are investigated. Finally the effect of mirror facet installation error on the optical performance of the heliostat is analyzed.