• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.6
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• pp.21-33
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• 2015

Recently, the Korean government announced a new development plan for a large-scale greenhouse complex in reclaimed lands. Wind environments of reclaimed land are entirely different from those of inland. Many standard books for ventilation design didn't include qualitative standard for natural ventilation. In this study, natural ventilation rates were analyzed to suggest standard for ventilation design of venlo type greenhouse built on reclaimed land. CFD (Computational Fluid Dynamics) simulation models were designed according to the number of spans, wind conditions and vent openings. The wind profile at a reclaimed land was designed using ESDU (Engineering Sciences Data Unit) code. Using the designed CFD simulation model, ventilation rates were computed using mass flow rate and tracer gas decay method. Additionally computed natural ventilation rates were evaluated by comparing with ventilation requirements. As a result of this study, ventilation rates were decreased with increasing of the number of spans. Ventilation rates were linearly increased with increasing of wind speed. When the wind speed was $1.0\;m{\cdot}s^{-1}$, only side vent was open and wind direction was $45^{\circ}$, homogeneity of ventilation rate at 0~1 m height is the worst. Finally, chart for computing natural ventilation rate was suggested. The chart was expected to be used for establishing standard of ventilation design.

• The Journal of the Petrological Society of Korea
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• v.11 no.2
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• pp.74-89
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• 2002

Rock units, relating with the Guamsan caldera, are composed of Guamsan Tuff and rhyolitic intrusions. The Guamsan Tuff consists almost entirely of ash-flow tuffs with some volcanic breccias and fallout tuffs. The volcanic breccia comprises block and ash-flow breccias of near-vent facies and caldera-collapse breccia near the ring fracture. The lower ash-flow tuffs are of an expanded pyroclastic flow phase from the pyroclastic flow-forming eruption with an ash-cloud fall phase of the fallout tuffs on the flow units, but the upper ones are of a non-expanded ash-flow phase from the boiling-over eruption. The rhyolitic intrusions are divided into intracaldera intrusions and ring dikes that are subdivided into inner, intermediate and outer dikes. We compile the volcanic processes along a single cycle of cadela development from the eruptive phases in the Guamsan area. The explosive eruptions began with block and ash-flow phases from collapse of glowing lava dome caused by Pelean eruption, progressed through expanded pyroclastic flow phases and ash-cloud fallout phases during high column collapse of pyroclastic flow-forming eruption from a single central vent. This was followed by non-expanded ash-flow phases due to boiling-over eruption from multiple ring fissure vents. The caldera collapse induced the translation into ring-fissure vents from a single central vent in the earlier eruption. After the boiling-over eruption, there followed an effusive phase in which rhyolitic magma was injected and erupted to be progressively emplaced as small plugs/dikes and ring dikes with many lava domes on the surface. Finally rhyodacitic magma was on emplaced as a series of dikes along the junction of both outer and intermediate dikes on the southwestern side of the caldela.

• Nuclear Engineering and Technology
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• v.41 no.5
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• pp.691-708
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• 2009

In order to analyze thermal hydraulic phenomena during a DVI (Direct Vessel Injection) line break LOCA (Loss-of-Coolant Accident) in the APR1400 (Advanced Power Reactor 1400 MWe), we performed experimental studies with the SNUF (Seoul National University Facility), a reduced-height and reduce-pressure integral test loop with a scaled down APR1400. We performed experiments dealing with eight test cases under varied tests. As a result of the experiment, the primary system pressure, the coolant temperature, and the occurrence time of the downcomer seal clearing were affected significantly by the thermal power in the core and the SI flow rate. The break area played a dominant role in the vent of the steam. For our analytical investigation, we used the MARS code for simulation of the experiments to validate the calculation capability of the code. The results of the analysis showed good and sufficient agreement with the results of the experiment. However, the analysis revealed a weak capability in predicting the bypass flow of the SI water toward the broken DVI line, and it was insufficient to simulate the streamline contraction in the broken side. We, hence, need to improve the MARS code.

• Journal of the Korean Society of Costume
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• v.63 no.8
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• pp.76-89
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• 2013

This study is about 'asymmetry triangle-Mu' Jeoksam and Hansam in the early days of Joseon Dynasty. A study was done regarding the records of Jeoksam and Hansam in literature, the present state of the excavated 'asymmetry triangle-Mu' clothing Jeoksam and Hansam, and finally a deduction of the reason for the appearance of the 'asymmetry triangle-Mu' clothing Jeoksam and Hansam. The width of front length of 'asymmetry triangle-Mu' clothing in the early days of Joseon Dynasty is 29.5~35 cm and the width of one breath of the sleeve is 29.5~35 cm. The width of 'asymmetry triangle-Mu' is 9.5~16 cm and it is relatively big. Comparing to the width of one breath of the sleeve, it is almost 1:2.2~3.6 ratio. Therefore, when the sleeve was cut, the Mu was linked in order to save fabric the gusset of sleeve had to be folded and turned, and finally it became asymmetric. As a result of the above consideration, since the width of upper garments of $16{\sim}17^{th}$ century was big, the wearing of short tops of Jeoksam or Hansam without side vent as a small 'triangle-Mu' was uncomfortable. Because of this reason, the size had no option but to become bigger. So, during the $16^{th}$ and $17^{th}$ century, a period where mass production of fabric was difficult, the 'asymmetry triangle-Mu' type was considered to be a reasonable cutting method. After the middle of $17^{th}$ century, it can be estimated that 'asymmetry triangle-Mu' clothing disappeared according to the narrow aspect of clothing type.

• Plant Journal
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• v.15 no.4
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• pp.36-42
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• 2019

In recent, according to the tightening of environment regulation policy, the height of the site of the power plant is increased and the length of the cooling water pipe is increased. This has a serious impact on the stability of the plant. This study analyzes the transient phenomenon using LIQT 7.2, an unsteady state one-dimensional analysis software, to secure the stability of 1,000 MW high-capacity coal-fired power plant cooling water system with high head. To prevent water hammer, The effects on performance characteristics were predicted by individual and combination application. The surge pressure of the cooling water which occurs when the pump was stopped without installing the anti-surge devices was the largest at the pump outlet side. The most effective and simple way to reduce surge pressure in these cooling water systems is to combine a vacuum breaker with a hydraulic non-return valve, which is an essential device for pump protection.

• Journal of Fashion Business
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• v.20 no.3
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• pp.43-53
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• 2016

As the quality of life has improved with development of science and technology, desire for better quality of life of disable people has also increased. Currently, prejudiced views of disabled people in South Korea are changing, but sports for all disabled people is not revitalized and social support is also inadequate. In developed countries, administration and systems for sports among people with disabilities are provided at the consumer level, and many companies willingly provide support to disabled athletes. However, in South Korea, low awareness of sports for disabled people is companied by minimal support companies. In order for South Korea to advance, support for the disable sports players is needed, especially sports-wear that fits their body conditions and differences game playing from ordinary sports players. This study specifically focused on the ice sledge hockey players, taking into account the complaints on their jersey and their special conditions through motion analysis while sleds. For the easy use of the hockey, armhole depth and sleeve breadth was reduced and sleeve hem was designed for flexibility of sleeve such that it does not slide down. Also, because only the front of the Jersey is tucked in the pants, the side vent was designed to be deep such that the back hem is prevented from being pulled. Sportswear pattern making for the players with disabilities required to account for distinct body characteristics, as compared to the ordinary players. Thus, studies that develops sports-wear design for those with disabilities contributes to the qualitative development of sports for people with disabilities.

• The Journal of the Petrological Society of Korea
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• v.7 no.3
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• pp.147-160
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• 1998

The Samrangjin Caldera, a trapdoor-type, formed by the voluminous eruption of the silicic ash-flows of the Samrangjin Tuff which is above 630m thick at the northern inside of the caldera and thinnerly 80m at the southern inside. The caldera volcanism eviscerated the magma chamber by a series of explosive eruptions during which silicic magma was ejected to form the Samrangjin Tuff. The explosive eruptions began with phreatoplinian eruption, progressed through small plinian eruption and transmitted with ash-flow eruption. During the ash-flow eruption, contemporaneous collapse of the roof of the chamber resulted in the formation of the Samrangjin caldera, a subcircular depression subsiding above 550m deep. During postcaldera volcanism after the collapse, flow-banded rhyolite was emplaced as cental plug along the central vent and ring dikes along the caldera margins. Subsequently rhyodacite porphyry and dacite porphyry were emplaced along the inner side of the ring dike. After their emplacement, residual magma was emplaced as a hornblende biotite granite stock into the southwestern caldera margin. In the northeastern part, the eastern dikes were cut final intrusions of granodioritic to granitic composition along the fault zone of $^{\circ}$W trend.

• Journal of Bio-Environment Control
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• v.11 no.1
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• pp.5-11
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• 2002

In this study, new development of natural ventilation window was accomplished to control environment of greenhouse with no use of farced ventilation during hot season. The ventilation effect of developed ventilation window was investigated in experimental greenhouse which was designed using side wall panel and folding type panel fur natural ventilation. Folding panel type ventilation window was designed to open upper part of the side wall and top of the roof using two hinges which are located bottom of the side wall and the roof panel to grab one side of each panels and guide the other side along with the guidance rail. Developed ventilation window has top ventilation part with maximum moving distance X=ι (1-cos$\theta$)=848.5 mm and side ventilation part with maximum moving distance Y=ι/2 $\times$sin$\theta$=1,184.4 mm at 45$^{\circ}$ of theoretical opening angle. It took 4.5 minutes to open roof vent fully and temperature at 1.2 and 0.8 m height decreased after 1 minute from starting opening and became equilibrium state maintaining 3-4$^{\circ}C$ difference after 2 minutes from complete opening. Air exchange rate was 15.2~39.3 h$^{-1}$ which was more than 10~15 h$^{-1}$ of continuous type and Venlo type greenhouse. The descent effect of temperature by ventilation windows was two times higher than Venlo type greenhouse.

• Journal of the Korean Wood Science and Technology
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• v.2 no.2
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• pp.32-34
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• 1974

The important results which have been obtained in the investigation can be recapitulated as follows. 1. As demonstrated by the experimental results and analyses concerning their effects in the on-ground type mushroom house, the constructions in relation to the side wall and ceiling of the experimental house showed a sufficient heat insulation on effect to protect insides of the house from outside climatic conditions. 2. As the effect on the solar type experimental mushroom house which was constructed in a half basement has been shown by the experimental results and analyses, it has been proved to be effective for making use of solar heat. However there were found two problems to be improved for putting solar house to practical use in the farm mushroom growing: (1) the construction of the roof and ceiling should be the same as for the on ground type house, and (2) the solar heat generating system should be reconstructed properly. 3. Among several ventilation systems which have been studied in the experiments, the underground earthen pipe and ceiling ventilation, and vertical side wall and ceiling ventilation systems have been proved to be most effective for natural ventilation. 4. The experimental results have shown that ventilation systems such as the vertical side wall and underground ventilation systems are suitable to put to practical use as natural ventilation systems for farm mushroom house. These ventilation systems can remarkably improve the temperature of fresh air which is introduced into the house by heat transfers within the ventilation passages, so as to approach to the desired temperature of the house without any cooling or heating operation. For example, if it is assuming that X is the outside temperature and Y is the amount of temperature adjustment made by the influence of the ventilation system, the relationships that exist between X and Y can be expressed by the following regression lines. Underground iron pipe ventilation system. Y=0.9X-12.8 Underground earthen pipe ventilation system. Y=0.96X-15.11 Vertical side wall ventilation system. Y=0.94X-17.57 5. The experimental results have 8hown that the relationships existing between the admitted and expelled air and the $CO_2$ concentration can be described with experimental regression lines or an exponent equation as follows: 5.1 If it is assumed that X is an air speed cm/sec. and Y is an expelled air speed in cm/sec. in a natural ventilation system, since the Y is a function of the X, the relationships that exist between X and Y can be expressed by the regression lines shown below: 5.2 If it IS assumed that X is an admitted volume of air in $m^3$/hr. and Y is an expelled volume of air in $m^3$/hr. in a natural ventilation system, since the Y is a function of the X, the relationships that exist between X and Y can be expressed by the regression lines shown below. 5.3 If it is assumed that expelled air speed in emisec. and replacement air speed in cm/sec. at the bed surface in a natural ventilation system are shown as X and Y. respectively, since the Y is a function of the X. the relationships that exist between X and Y can be expressed by the following regression line: GE(100%)-CV (50%) ventilation system. Y=-0.54X+0.84 5.4 If it is assumed that the replacement air speed in cm/sec. at the bed surface is shown as X, and $CO_2$ concentration which is expressed by multiplying 1000 times the actual value of $CO_2$ % is shown as Y, in a natural ventilation system, since the Y is a function of the X, the relationships that exist between X and Y can be expressed by the following regression line: GE(100%)-CV(50%) ventilation system. Y=114.53-6.42X 5.5 If it is assumed that the expelled volume of air is shown as X and the $CO_2$ concencration which is expressed by multiplying 1000 times the actual of $CO_2$% is shown as Y in a natural ventilation system, since the Y is a function of the X, the relationships that exist between X and Y can be expressed by the following exponent equation: GE(100%)-CV(50%) ventilation system. Y=$127.18{\times}1.0093^{-x}$ 5.6 The experimental results have shown that the ratios of the cross sectional area of the GE and CV vent to the total cubic capacity of the house, required for providing an adequate amount of air in a natural ventilation system, can be estimated as follows: GE(admitting vent of the underground ventilation) 0.3-0.5% (controllable) CV(expelling vent of the ceiling ventilation) 0.8-1.0% (controllable) 6. Among several heating devices which were studied in the experiments, the hot-water boilor which wasmodified to be fitted both as hot-water boiler and as a pressureless steam-water was found most suitable for farm mushroom growing.

• Journal of Fashion Business
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• v.11 no.5
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• pp.35-50
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• 2007

The purpose of this study was to investigate the result of a market research on men's jacket in their age of 25 to 35, who wear fitted jackets most, and to examine the comparative analysis of pattern and the wearing evaluation between classic jacket and fitted jacket. The results are as follows; Firstly, according to the results of a market research, 32.0% of the target owned fitted jackets, and 28.7% expressed their desire to buy only fitted jackets. This means their concern and preference for fitted jacket with which they could show up young, fresh and slim look are as high as those for classic jacket. Secondly, classic jacket showed the higher value than fitted jacket in such items as chest girth, waist girth, hip girth, sleeve's hem girth, jacket length, shoulder length, side seam length, and across shoulder point length. On the other hand, fitted jacket showed the higher value than classic jacket in back armhole length, front length, collar point length and sleeve's vent length. Thirdly, classic jacket was larger than fitted jacket in 1/2 chest girth(1.0cm), 1/2 waist girth(2.0cm), 1/2 hip girth(1.0cm), back width(0.5cm), front width(0.5cm) and side width(1.0cm). However, fitted jacket was higher than classic jacket in the armhole depth(0.5). Fourthly, the results of appearance evaluation revealed that there was a significant difference in 6 items. In other words, classic jacket was evaluated more appropriate than fitted jacket in such items as back width, back length, back neck depth, chest girth, waist girth and hip girth. And the fitted jacket had a higher value than the classic jacket in shoulder angle item. Fifthly, In the functional evaluation, fitted jacket was evaluated more uncomfortable than classic jacket. And this means that fitted jacket doesn't have a proper ease amount in each part and it has a high armhole depth compared to classic jacket. Therefore, for more comfortable patternmaking of fitted jackets, it would be required a pattern design which reflect men's own shoulder lines and women designers' flexibility that will satisfy both appearance and function.