• Journal of the Society of Naval Architects of Korea
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• v.50 no.3
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• pp.167-174
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• 2013

Model ice forming process in ice tank needs several steps of seeding, freezing, tempering. In those process, one of the most important factors to affect the accuracy of experiment is the homogeneity of the ice thickness and the temperature. This paper investigated a computational and statistical method to assess the uniformity of the model ice. In addition, the different configurations of freezing systems were considered to improve the uniformity. Qualitative assessment using streamlines from the cooling units was carried out by computational fluid dynamics (CFD) and the quantitative evaluations of the homogeneity were compared using the temperature distribution on the ice surface. In addition, multi species transport analysis is introduced to understand the circulation efficiency of cold air from the cooling units. As the results, optimized configurations were determined by adjusting the angles of vane in the cooling units.

• Journal of Korean Medical classics
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• v.35 no.1
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• pp.155-172
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• 2022

Objectives : Contents on the 64 trigrams in major medical texts from early to late Joseon such as the Uibangyuchwi(醫方類聚), Donguibogam(東醫寶鑑), Somundaeyo(素問大要), Gyeokchigo(格致藁) were analyzed to examine their characteristics and historical context. Methods : Related contents in each medical texts were collected, sorted and analyzed for thorough examination. Results : The study of Changes which was widely applied in the field of medicine throughout the Joseon period focused more heavily on each of the trigram patterns, especially in regards to the qi interaction between the upper and lower axis of the body, rather than the various meanings of the ten wings[十翼]. This is a result of the Jing-Qi-Shen perspective of the body and the universe that transcends the Daoist inner cultivation method[內丹術], under which concepts related to qi circulation such as the opening and closing[闔闢] of the Heaven[乾] and the Earth[坤], the interaction between Water[水] and Fire[火] were considered more important. Conclusions : The historical context of the study of medicine and Changes[易] of Korea could be grasped through analysing the 64 trigrams in medical texts of each period in Joseon. Further research with the field of History of Changes studies is much anticipated.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.11a
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• pp.211-216
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• 1996

Since the middle of the eighties of this century a research program both for heating reactor and investigation of heating reactor thermal-hydraulics has been carried out in Institute of Nuclear Energy Technology(INET) of Tsinghua university in China. This kind of heating reactor is a light water cooled and integrated natural circulation reactor with low system pressure and low quality at the exit of core. Because of relatively long riser and low system pressure. a little change of the quality at the exit of the core will result in a relatively large variation of void fraction in the riser. Two full scale test loops. HRTL-5 and HRTL-200 simulating the HR-5 and HR-200 heating reactors in geometry and operation parameters respectively, and some test results from the HRTL-200 test facility are shown in this paper. The range of studied system pressure is from 1.0MPa to 4.0MPa, the largest heat flux is about 50 W/cm2, and the quality at the exit of test section is less than 5%.

• Journal of Ocean Engineering and Technology
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• v.24 no.4
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• pp.8-12
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• 2010

The use of a tidal-current power system is one source of renewable energy that can minimize the environmental impact of power production and offer many other advantages compared to conventional energy sources. Unlike other energy production approaches, rate of energy production can be precisely predicted and the operational rate is very high. The performance of the rotor, which has a vital role in energy production using tidal currents, is determined by various design factors, and it should be optimized for the specific ocean environment in the field. The horizontal-axis turbine is very sensitive to the direction of flow, and flow direction changes due to rise and fall of the tides. To investigate the performance of the rotor considering the interaction problems with incidence angle of flow, a series of experiments were conducted, and a 3D CFD model was designed and analyzed by ANSYS CFX. The results and findings are summarized in the paper.

• Advances in nano research
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• v.15 no.4
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• pp.329-337
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• 2023

Wearing the right sportswear is one of the essential points in exercising, which is mainly neglected. Sportswear should be suitable for the ambient temperature and not cause more heat or cold in the athlete's body. On the other hand, increased sweating and blood circulation during exercise should not cause fatigue or heatstroke in the athlete. Nanotechnology has grown significantly in the field of producing more efficient equipment in the field of sports. The increase in demand in sports for complete sports equipment has revealed the necessity of using the highest quality materials in this sector. In the world of championship sports, a minor change in equipment can lead to significant changes in causing failure and victory. Since the sole is the most critical part of sports shoes, with the introduction of nanotechnology and nanocomposites, it is possible to help athletes rush and increase their sense of calm and satisfaction. Using nanocomposites in the soles of shoes can improve some of their characteristics, prevent the smell and sweat of shoes, and induce water repellency in these shoes. In this research, titanium dioxide (TiO₂) nanocomposite, along with cellulose, has been used to create antibacterial and hydrophobic properties in the soles of sports shoes. The synthesized nanocomposite has been synthesized using the least amount of chemicals, which shows this method's easy and cost-effective synthesis.

• The Journal of Korean Medicine
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• v.25 no.4
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• pp.26-35
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• 2004

Drynariae Rhizoma (DR), an herbal medicine known to clean blood and improve its circulation, frequently appears as the main ingredient in the prescriptions for bone injuries. Currently, it is unclear how contributes pharmacologically to the reformation of bone. Therefore, we have done this study. Systematic administrations of TGFβ1 and water extract of DR diminished the polyarthritis development in rats. TGFβ administration (0.1-2 ㎍/animal) and DR (10-100 ㎍/animal), initiated 1 day before an arthritogenic dose of streptococcal cell wall fragments, virtually eliminated the joint swelling and distortion observed during the acute phase and the chronic phase of the disease. The TGFβ and DR synergistically suppressed the arthritis when the administration was begun after the acute phase of arthritis. Also, the synergistic activity between TGFβ and DR was confirmed in their suppression of arthritis in rats. Consistent with the inhibition of inflammatory cell recruitment into the synovium, TGFβ1 and DR reversed the leukocytosis associated with the chronic phase of the arthritis.

• Journal of the Korean Institute of Landscape Architecture
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• v.34 no.4 s.117
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• pp.116-128
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• 2006

This study focuses on hydrological changes caused by developments in the 13th, 14th (Motjarigol) district in Eun Pyoung New Town, Seoul on the basis of the Land Use Planning of development plan. Through analyses from the hydrological experiments about rainfall outflow using universal equation and amounts of infiltration through soils, the changes in amounts of overflows were estimated and the results were discussed from a urban ecological point of view. As a result, it has been predicted that the amount of rainfall outflow at post-development was dramatically increased, compared to pre-development. Installing of Derbris Dams and infiltration facilities were suggested as alternative plan to meditigate these changes. If we apply these alternatives, the rainfall outflow would be reduced up to 30% compared to the development plan without BMPs (Best Management Practice). In conclusion, it is proposed that once the ecological principles were considered during development planning process, we can minimize the adverse effects of developments to our environments.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.5
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• pp.312-317
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• 2017

In this paper, the effects of environmental variables on the output of the floating photovoltaic water systems, which were installed at the Hapcheon dam in South Korea, were investigated, and the correlations between them were analyzed. The system output was linearly proportional to the solar radiation or irradiance. The output was large in spring and autumn because of high irradiance, but low in the summer when the solar module temperature was high. The influence of the module temperature on the system output was limited in the summer, during which the module temperature change affected the system output more than the change of the irradiance did. In addition, in winter and summer, the module temperature tended to decrease with increasing windspeed, but windspeed did not affect module temperature significantly in the spring and autumn. On the other hand, in winter and spring, the irradiance decreased as the windspeed increased because of movement (or circulation) of the photovoltaic modules.

• Journal of the Korean Solar Energy Society
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• v.33 no.1
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• pp.57-65
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• 2013

The temperatures with the ground depth, the positions of circulation water in ground heat exchanger were measured and thermal diffusion characteristics with the distances of the direction normal to the borehole was analysed. The deeper the depth of ground, the less the influences of outdoor temperature, but below 10m of ground, there was no influences of ground temperature. When the depth of trench pipe was below the depth of 2m, there was no influence. In the ground of 10m when the distances between the pipe and the other places were above 0.5m, the variations of temperature were less than $1.6^{\circ}C$ and above 2.5m they were less than $0.1^{\circ}C$. When the distances of bore hole were above 5m, there were no. influences of the nearest ground heat exchanger.

• 대한상한금궤의학회지
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• v.12 no.1
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• pp.61-70
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• 2020

Objective: The aim of this study was to analyze the origin and characteristics of Allii Macrostemi Bulbus. Methods: Bibliographies on Allii Macrostemi Bulbus that focused on the origin of the material were examined. Based on this analysis, an inventory was prepared and the characteristics of the original material are presented. Results: Korean and foreign literature were reviewed to prepare an inventory, and Based on these results, the state of plants either currently cultivated or distributed as medicines, , and are summarized. 1. The origin of Allii Macrostemi Bulbusis the scaly stem of Allii macrozoon Bunge or Allii bakeri Regel. 2. The current white water mark in circulation is the scaly stem of the sandalae Allii macromoleon Bunge. 3. Scilla sinensis(Lour.) Merr. is. 4. The properties of Scilla sinensis(Lour.) Merr. are cool and bitter, healing the forests, mowing the ointment, stopping the oxen, and curing the absence of distractions and stuffy symptoms and removal of the placenta after childbirth. Conclusions: The origin of Allii Macrostemi Bulbusis the scaly stem of Allii macrozoon Bunge or Allii bakeri Regel.