• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• 제21권12호
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• pp.1380-1393
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• 2010

This paper presents a design, fabrication and the test results of planar active electronically scanned array(AESA) radar prototype for airborne fighter applications using transmit/receive(T/R) module hybrid technology. LIG Nex1 developed a AESA radar prototype to obtain key technologies for airborne fighter's radar. The AESA radar prototype consists of a radiating array, T/R modules, a RF manifold, distributed power supplies, beam controllers, compact receivers with ADC(Analog-to-Digital Converter), a liquid-cooling unit, and an appropriate structure. The AESA antenna has a 590 mm-diameter, active-element area capable of containing 536 T/R modules. Each module is located to provide a triangle grid with $14.7\;mm{\times}19.5\;mm$ spacing among T/R modules. The array dissipates 1,554 watts, with a DC input of 2,310 watts when operated at the maximum transmit duty factor. The AESA radar prototype was tested on near-field chamber and the results become equal in expected beam pattern, providing the accurate and flexible control of antenna beam steering and beam shaping.

• Journal of the Computational Structural Engineering Institute of Korea
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• 제23권1호
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• pp.1-8
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• 2010

The Fourier series uses a vibrating wave that possesses an amplitude that is like the one of the sine curve. Therefore, the functions used in the Fourier series do not change due to the value of the frequency and that set a limit to express irregular signals with rapid oscillations or with discontinuities in localized regions. However, the wavelet series analysis(WSA) method supplements these limits of the Fourier series by a linear combination of a suitable number of wavelets. By using the wavelet that is focused on time, it is able to give changes to the range in the cycle. Also, this enables to express a signal more efficiently that has singular configuration and that is flowing. The main objective of this study is to propose a scheme called wavelet series analysis for the application of wavelet theory to one-dimensional problems represented by the second-order elliptic equation and to evaluate theperformance of proposed scheme comparing with the finite element analysis. After a through evaluation of different types of wavelets, the HAT wavelet system is chosen as a wavelet function as well as a scaling function. It can be stated that the WSA method is as efficient as the FEA method in the case of axial bars with distributed loads, but the WSA method is more accurate than the FEA method at the singular points and its computation time is less.

• Journal of the Korean Magnetics Society
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• 제22권2호
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• pp.58-65
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• 2012

Since Nd-Fe-B magnet was first synthesized in 1983, many new applications have emerged in the past two decades. With regard to motor market, it will expand because of strong energy saving requirements from the automobile and electric application markets. Especially, permanent magnet motors for hybrid and electric vehicles are drawing great attention and the usage of Nd-Fe-B magnets will increase all the more hereafter. There is, however, a serious problem as motors in such eco-friendly cars are said to operate in high temperatures of about $200^{\circ}C$. Nd-Fe-B magnet has a drawback of dramatically decreasing coercive force with the rise of temperature. In order to improve this aspect. the best way is to add dysprosium (Dy) into the magnet. So, Dy has become an essential element for Nd-Fe-B high-performance magnet as it helps to maintain coercive force even at high temperatures. On the other hand, the rare earth resources in the earth crust are eccentrically-located and its majority is produced in China. There is a need to reduce its usage as, especially compared to light rare earth elements as neodymium (Nd) and samarium (Sm), heavy rare earth elements including Dy are unevenly distributed to a dramatic degree, their output low, and their prices are about 10 times that of Nd. The present article includes a summary of the trend in research and development of motors and permanent magnets to solve rare-earth resources problem.

• Journal of the Korean earth science society
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• 제29권3호
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• pp.221-245
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• 2008

The precambrian granitic gneiss and porphyroblastic gneiss are widely distributed in the Gwangyang-Hadong area of Korea. This study focuses on the geochemical properties and metamorphic P-T conditions of these gneisses. These gneisses are plotted according to granodiorite domain on an IUGS silica-alkali diagram. Geochemical properties of major elements suggest that these rocks are of the sub-alkalic rock series, and were farmed from S-type magmas which were generated in a syn-collision tectonic environment. The amounts of trace elements (Zn, Sc, Sr, V, etc.) decreased as $SiO_2$ concentrations increased. Almandine and spessartine mol%'s and XFe are higher in garnet rims, while pyrope mol%'s are higher in the garnet cores. This seems to be the result of garnet growth and retrogressive metamorphism. Metamorphic zones are divided into sillimanite-cordierite, sillimanite, garnet, and biotite zones. Metamorphic P-T conditions estimated from the gneisses indicate high temperature and low to medium pressure metamorphism (689-757$^{\circ}C$, 5.0-5.6 kbar), followed by medium temperature, low pressure retrorade metamorphism (579-628$^{\circ}C$, 3.1-4.5 kbar), and overprinted retrogade metamorphism (502-558$^{\circ}C$, 1.6-2.3 kbar).

• Journal of Bio-Environment Control
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• 제21권4호
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• pp.327-335
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• 2012

Nutrient uptake of each part of grapevine in the new grapevine cultivars (Jinok, Hongisul) was analyzed for making standard of annual fertilizations at four years. One year grown diploid cultivar 'Jinok' was showed more vigorous growth of root than other cultivar. Annually total nutrient of grapevine was absorbed with the same ratio of three major nutrients (Nitrogen, Phosphate, and Potassium). However about 30% of total absorbed nutrient of 3~4 year grown grapevine was distributed bunches. Potassium was measured as major nutrient in the bunch, accumulated in the peel and flesh (about 1% of D.W.). Magnesium was mainly accumulated in the petiole (about 1% of D.W.). Calcium has accumulated in the leaf (about 0.95% of D.W.), that concentration in this part was similar concentration of nitrogen (about 1.25% of D.W.). Nutrient requirement of four year grown 'Jinok' (N; 55.5 g, P; 7.7 g, K; 42.0 g, Ca; 34.6 g, Mg; 11.1 g) required less fertilizers than 'Campbell Early' (N; 57.4 g, P; 7.9 g, K; 44.4 g, Ca; 37.3 g, Mg; 12.2 g) needed. 'Hongisul' required less fertilizers compared to other grapevine cultivars, but cultural practice system for production of grape should be develop to improve their poor bud burst and fruit set.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• 제28권3호
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• pp.105-113
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• 2010

This study is for the preservation plan of the tradition space which is performed by the damage status analysis through performing the value assessment. Especially, it is an experimental study for finding the process and methods by analyzing the major element for the value assessment of the selected object's damage status through the expert group who are systematized in their interest to conserve the traditional structure in traditional space. For that purpose, this study should be performed by the fundamental understanding of the physical property of the Supyo-bridge and the condition of the selected site's environment. Meanwhile, this study has been done that 'map of the damage status distribution' for making records of damage status of the Supyo-bridge on the property utilized field measurement adapted by photogrammetry and assessment guidelines, which are for investigation on damage status of objects that are standardized 'Raccomandazioni Normal' which could be said construction culture assets management guidelines of Italian government. As the result of investigation, damage status of each part in the Supyo-bridge was mostly composed of damage by sediment and corrosion and in case of 9 damage types including corrosion, in consideration of physical and chemical properties and distribution status of those elements, it is made an judgement that is not working as a threatened factor regarding security of the Supyo-bridge. On the contrary, for the improvement landscape, in case of 'Thermoclastism' phenomenon observed in 'upper floor', 'Myungae stone' and 'bridge pier' is that when taking it into consideration that is widely distributed concentrated on the bridge pier, surface reinforcement job along with elimination of damage part will be judged to be requested for earliest treatment.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제15권10호
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• pp.6344-6353
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• 2014

According to the changes in society, the knowledge industrial center, which is a factory related to the manufacturing industry, is now including various programs, such as information and communication knowledge. This study defined the knowledge industrial center related law into three periods: deduct layout planning type and outside space composition elements by previous research; case analysis; and suggestions of the direction of layout planning and outside space plan. As a result of the analysis, first, before 1999, the layout of the building is made mainly with a car, but depending on the form of the site, it is configured as a centered, side layout. Second, in the case of distribution, the support facility on the lower part is integrated and the factory on the higher part is distributed, so it is partly integrated and the building is unified. Third, beginning with the activation of privately owned public space in a semi-industrial district according to architecture regulations in 1999, the outside space is wider but the construction area is reduced, so the outside space composition has been changing in a similar manner to the planning methods of business facilities, such as office buildings.

• Korean Journal of Medicinal Crop Science
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• 제28권4호
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• pp.276-286
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• 2020

Background: Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease associated with multiple metabolic disorders. The medicinal plant Curcuma longa L. is widely distributed in Asia and has been used to treat a spectrum diseases in clinical practice. To date, there are inadequate reports of the effects of C. longa 50% EtOH extract (CE) on NAFLD. Therefore, in this study, we evaluate the CE on an NAFLD animal and elucidate the mechanism of action. Methods and Results: C57BL/6J mice fed a methionine-choline deficient diet (MCD) were treated with CE or milk thistle, and changes in inflammation and stetosis were assessed. Experimental animals were divided into six group (n = 10); Normal, MCD, MCD + CE 50 mg/kg/day (CE 50), MCD + CE 100 mg/kg/day (CE 100), MCD + CE 150 mg/kg/day (CE 150), and the Control, MCD + Milk thistle 150 mg/kg/day (MT 150). Body weight, liver weight, liver function, and histological changes were assessed in experimental animals. Quantitative real-time polymerase chain reaction and western blot analyses were performed on samples collected after 4 weeks of treatment. We observed that CE administration improved MCD-diet-induced lipid accumulation, and triglyceride (TG) and total cholesterol (TC) levels in serum. Treatment with CE also decreased hepatic lipogenesis through modulation of the sterol regulatory element binding protein-1 (SREBP-1), CCAAT-enhancer binding protein α (C/EBPα), fatty acid synthase (FAS), and peroxisome proliferator-activated receptor γ (PPARγ) expresion. In addition, the use of CE increased adenosine monophosphate-activated protein kinase (AMPK) phosphorylation and inhibited the up-regulation of toll-like receptor (TLR)-2 and TLR-4 signaling and the production of inflammatory mediators. Conclusions: In this report, we observed that CE regulated lipid accumulation in an MCD dietinduced NAFLD model by decreasing lipogenesis. These data suggeste that CE could effectively protect mice against MCD-induced NAFLD, by inhibiting the TLR-2 and TLR-4 signaling cascades.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제20권1호
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• pp.208-216
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• 2019

Rural houses are losing their original shape as they mimic the spatial composition of urban houses. Therefore, the purpose of this study was to extract the design elements needed for rural housing by applying Christopher Alexander's "A PATTERN LANGUAGE" to Standard Rural-House Design (SRHD). The scope and method of research was to compare and analyze the standard designs (SD) produced and distributed by the 'Korea Rural Community Corporation' from 2009 to 2014. The research result is summarized as follows. 1) The housing layout in the SD ignored the site conditions of various rural areas. 2) Most of the houses were not actively planned, considering that they contain various activities of rural life. 3) There was no room for children and the kitchen was planned to integrate the interior into a flexible space in the form of L.D.K. 4) There was no space plan that could be used as both a leasable annex and office space for the farming community. 5) Many small area plans were made because of the SD plan for couples only in 2014. Although the rural environment and living patterns were ignored in the SD, the diverse pattern language provided by the pattern language was developed as a SD element for rural houses, which is the most suitable housing plan for the farmers' livelihood pattern.

• Journal of Life Science
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• 제29권10호
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• pp.1144-1151
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• 2019

Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease associated with various metabolic syndromes, such as obesity, dyslipidemia, hypertension, and diabetes. Cudrania tricuspidata is a medicinal plant distributed widely in Asia and has been used in clinical practice to treat various diseases. The aim of this study is to determine the lipid-lowering effects of C. tricuspidata fruit extract (CTE) using a cell model induced by free fatty acids (FFAs). HepG2 cells were exposed to 1mM FFAs (palmitic acid:oleic acid = 2:1) for 24 hr to simulate the conditions of NAFLD in vitro. CTE attenuated the increases of lipid accumulation, intracellular triglyceride, and cholesterol content and inhibited 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoA reductase) activity in the HepG2 cells in a dose-dependent manner. Also, CTE inhibited the protein expression of lipogenesis-related genes, such as sterol regulatory element-binding protein-1/-2 (SREBP-1/-2), fatty acid synthase (FAS), and stearoyl CoA desaturase-1 (SCD-1) in FFAs-induced lipid accumulation in HepG2 cells. In addition, CTE-induced adenosine monophosphate-activated protein kinase (AMPK) phosphorylation in HepG2 cells. These results suggest that CTE attenuates hepatic lipid accumulation by inhibiting lipogenesis through the modulation of the AMPK signaling pathway on FFAs-induced lipogenesis in HepG2 cells and may potentially prevent NAFLD.