• Journal of Power Electronics
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• v.5 no.4
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• pp.257-263
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• 2005

This paper describes the development and testing results of a high density High Voltage Power Supply (HVPS) that drives microwave Traveling Wave Tubes (TWTs) of phased array transmitters for airborne EW systems. The HVPS is designed to consist of a number of modules connected in series. Among them, especially, the high-density pulse transformer module including the resonant circuit is newly designed to make the HVPS much more reliable. In addition, this paper describes the development of high voltage solid-state modulation using fast switching devices (FETs) and also represents the test results of a modulator module.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2009.11a
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• pp.132-137
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• 2009

The purpose of this study was to suggest urban regeneration methods for deteriorated downtown residential area, considering the development condition of urban blocks. Through the research that are based on literature, field survey, urban planning map and local experts consulting, it found out suitable sites for development such as a deteriorated residential zone or a unused site and it was deduced eight development types from analyzing the characters of developable sites. And then it is suggested various housing forms which were applied to eight development types of developable sites. The consequences of this research are summarized as follows. There are various housing forms by eight development types; block housing, low rise-high density court housing, medium low rise-high density housing, urban housing for low-income groups belong to T1-development of urban strategic position; block housing, housing on hilly site, semi-detached house, lodging house, urban housing for low-income groups, elderly housing belong to T2-development for living benefit; block housing, low rise-high density court housing, housing on hilly site, low rise housing, lodging housing, urban housing for low-income groups, elderly housing belong to T3-development of a small-scale rental housing; block housing, low rise-high density court housing, medium low rise-high density housing, terrace-house, housing on hilly site, low rise housing, block-typed detached house, semi-detached house, cluster-typed low rise housing, town house, urban housing for low-income groups belong to T4-residential environment renewal development; terrace-house, housing on hilly site, low rise housing, block housing, semi-detached house belong to T5-development of a small-scale housing; terrace-house, housing on hilly site, low rise housing, cluster-typed low rise housing belong to T6-development to adapt natural environment; block housing, low rise-high density court housing, low rise housing, block-typed detached house, town house belong to T7-development for community; block housing, low rise-high density court housing block housing, medium low rise-high density housing, terrace-house, housing on hilly site, low rise housing, elderly housing belong to T8-development of environment-friendly.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.5B no.1
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• pp.1-5
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• 2005

The vector magnetic property is defined as the relationship between the magnetic field strength vector H and the magnetic flux density vector B. It is very important for the development of high efficiency and the high-density electric machines. The electrical steel sheet for the machine core shows the remarkable vector behavior by the high magnetic flux density level. In this paper, the magnetic characteristic analysis using E&S2 model is introduced as the useful technology for the design and development.

• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.256-259
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• 2003

In this paper describes the development testing results of high density High Voltage Power Supply(HVPS) that employ microwave TWTs. The HVPS consist of number of modules connected in series. A new design that adapt resonant circuit and high density pulse transformer to the high voltage modules makes the HVPS much more reliable. Also High voltage Solid-State modulation using fast switching devices(FET's) and the test results of modulator modules development are represented.

• KIEAE Journal
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• v.9 no.2
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• pp.17-26
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• 2009

High-rise and high-density apartment complexes have been built and supplied on a large scale in the 1st period New Town of metropolitan areas since the late 1980s. Recently it has become necessary to improve those apartment complexes which have blight problems for aging more than about 20 years accompanying simultaneity and a large scale. The purpose of this study is to analyze actual conditions of high-rise and high-density apartments in a view of sustainable regeneration. The contents and methods of this study are as follows. First, the concept of high-rise and high-density in domestic apartment developments were identified through review of literature and the law. Second, development conditions of Bundang new town and 1st period new town were studied. Third, the evelopment conditions of high-rise and high-density apartments in cases of 6 apartment complexes were analyzed from points of view of sustainable development by literature review and a field study. The results of this study are as follows. First, high-density range in domestic apartments can be conceptualized as 600 persons/ha. High-rise range in domestic apartments can be onceptualized as more than 11 stories under 30 stories. Second, characteristics and subjects based on actual conditions analysis could suggest on physio-environmental aspect and socio-economic aspect. Major characteristics and subjects of the physio-environmental aspect were 1.satisfaction of convenient facilities and public transportation service, 2.shortage of parking space, 3.uniform & blight of community facilities, 4.uniformed building layout, and 5.uniform pattern of unit plan and low flexibility by the bearing wall structure. And those of the socio-economical aspect were 1.satisfaction of current community, 2.increase and diversity of needs of the elderly by socio-demography change, 3.improvement of size and method of apartment complex development and 4.raising of economic-sufficiency.

• Korean Journal of Agricultural Science
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• v.50 no.4
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• pp.841-860
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• 2023

The present study was conducted to evaluate the effects of dietary mangosteen peel extract (MPE) on growth performance, serum biochemistry, jejunum morphology, and cytokine levels in growing pigs raised at a high stocking density. A total of 120 male growing pigs (43.68 ± 0.48 kg) were randomly arranged in a 2 × 2 factorial design with stocking density (high; HD, 0.55 m²/pig and normal; ND, 0.82 m²/pig) and dietary MPE (0 or 5 g/kg) as factors. Each treatment had six replicates with four or six pigs per treatment. Feed and water were provided ad libitum for 6 weeks. The HD group exhibited lower final body weight, average daily gain, and average daily feed than the ND group (p < 0.05). None of the factors affected villus height to crypt depth ratio. Dietary MPE, but not stocking density, increased IL-10 levels in the serum com-pared to the non-supplemented control diet (p < 0.05). In the microbiome analysis, alpha diversity analysis showed significant reductions in the MPE-treated group only under normal density conditions. High density stress induced gut microbiome changes and these response was differ between normal and MPE diet fed pigs. Overall, each group exhibited different major microbial composition in the gut. In conclusion, there were significant changes in the major microbial composition in response to high-density stress, and this variation was influenced by dietary treatment.

• The Transactions of the Korean Institute of Power Electronics
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• v.26 no.2
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• pp.112-119
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• 2021

This study proposes a design method of high-power-density and high-efficiency low-voltage DC-DC converters using SiC MOSFET and the optimized planar transformer design procedure based on the figure-of-merit. The secondary rectifying circuit of the phase-shifted full-bridge converter is compared to achieve high power density and high efficiency, and the phase-shifted full bridge converter with a current-doubler rectifier is selected. The planar transformer is designed by the proposed optimized design procedure and verified by FEA simulation. To validate the proposed design method, experimental results from a 3 kW prototype are provided. The prototype achieved 95.28% maximum efficiency and a power density of 2.98 kW/L.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.10a
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• pp.231-234
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• 2002

This thesis is to introduce development process and application for domestic production of Automation System for High Density and Perpendicular Storage used in the industrial field. Most of the traditional Automation Systems for High Density and Perpendicular Storage are imported and using in the industrial field. As a result of this condition, foreign competitive power is decreased cause increasing of production cost. In spite of economical burden to protect a loss with management in the case of the industrial field dealing with various products, imported Automation System for High Density and Perpendicular Storage is used. On this developed Automation System for High Density and Perpendicular Storage solved these problems. Developed system uses managing computer, it is easy to manipulate input and output of production and inventory management. Moreover, Developed system accomplished shortened driving time and mechanical safety.

• Journal of the Korean housing association
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• v.22 no.3
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• pp.101-111
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• 2011

This study was conducted to investigate the indiscriminate development occuring as a result of high-density land use per lot in residential areas of Seoul, which mainly consist of detached houses. The primary goals of this study were: (1) to suggest a block unit development method as an alternative architectural method of the current uniform development, in which high-rise and high-density apartments are usually built; and (2) to check the feasibility of the suggested method. Based on the analyses of the existing block composition types of residential areas, the prerequisite planning indices for applying a collective housing model were investigated. Subsequent to applying a collective housing type within each unit block, the collective housing model was analyzed. The results of the analyses showed that indiscriminate development was rampant in detached urban houses areas, and more than 70% of the buildings constructed before the 1980s needed re-development. The feasibility of the models was investigated depending on the models of low-rise and high-density collective housing, which utilize various block arrangements such as the court type, linear type, villa type, and composite type. The results of this study showed that the newly applied low-rise and highdensity multiple dwelling housing model in urban individual residential area significantly contributed to creating a good living environment in terms of both physical and psychological aspects.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.10a
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• pp.79-80
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• 2016

In this study, we measured the relative density and the compressive strength in order to select the appropriate W/ B for the ultra-high strength concrete development. If W/B is lowered than the W/B of highest relative density, it was confirmed that the strength is lowered. However, if water is increased than the W/B of highest relative density, the relative density is decreased compressive strength was similar. The selection of the W/B of the lower than the highest relative density is not appropriate. Appropriate W/B is selected to be more than the maximum relative density of W/B.