• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.8
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• pp.767-773
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• 2010

This paper describes development of a non-explosive separation device which can be equipped on small satellites. The spur geared micro DC motor, which has high reliability and advantage of price, is adopted as an actuator. The proposed separation device has resettability and it does not need extra jig to reload. In addition, the simple structure makes it easy to fabricate and assemble. To verify the performance of the proposed device, the response time tests, maximum preload tests and maximum shock level tests were performed. Also, through the vibration tests and thermal vacuum tests, feasibility of the proposed separation device was shown in launching and space environments. Therefore, we expect that the proposed separation device can replace the imported separation devices in near future.

• Journal of Families and Better Life
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• v.26 no.3
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• pp.169-189
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• 2008

There are few studies on the characteristics of defaulters, though research in this field is needed. The purpose of this study was to find out social, economic and psychological characteristics of defaulters who are married and in their thirties. For this study, an in-depth interview was used. The major findings were as follows. The focus of this study is defaulters who are married, in their thirties, have managed small businesses by themselves or with their spouses and have experienced job fluctuation. There were a lot of reasons for their becoming defaulters. Most of all, a slump in business with the occurrence of individual events caused them to be enrolled as defaulters. The monthly mean income of defaulters was $1,800,000{\sim}5,000,000$ won, yet it was irregular. Moreover, they were dependent upon labor income or business income. The monthly mean expenditure of defaulters was $1,000,000{\sim}2,300,000$ won, which constituted about $26%{\sim}57.5%$ of their monthly mean income. The defaulters needed to budget a number of expenditures such as food and private education. Defaulters had $25,000,000{\sim}128,000,000$ won in debts and $300,000{\sim}3,000,000$ won per month in debt payments. Most of them didn't have any emergency funds, monetary assets or fixed assets. Interestingly, they showed high tendency to use debt and low skill for their money management. Defaulters had short time horizons and were likely to buy something on the spur of the moment.

• Journal of the Society of Naval Architects of Korea
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• v.53 no.5
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• pp.410-419
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• 2016

With the aim of reducing greenhouse gas emissions by 20 percent by 2020 and by 50 percent by 2050 from their 2005 level, International Maritime Organization (IMO) regulated the emissions of SOx and NOx by setting the emission control area in 2012. Since these environmental regulations have been reinforced, demands for the LNG fuel ships are expected to increase dramatically. Accordingly, the worldwide shipbuilding companies spur the development of the LNG fueled ships. Therefore, it is essential to carry out the research on the development of LNG fuel tank, which is one of the important components of the LNG fuel supply system. In this study, the deliberate finite element analysis of type-B LNG fuel tank for 10,000 TEU containership was carried out to evaluate structural safety and provide the process for analyzing stress levels and evaluating fatigue life of target structural. In particular, thermo-structural analysis and fatigue analysis were carried out using the databases on materials and structures of LNG fuel tank.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.6
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• pp.1259-1273
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• 2012

As a society of knowledge and information has been developed rapidly, because of changing from web environment to ubiquitous environment, a lot of countries across the world as well as S. Korea for national information with electronic Government have a variety of changes with big data. So this study is about development for national information and e-government of S. Korea with public data as big data analysed by the application of scenario planning. And then this research focused on the strategy consulting of national information with e-Government of S. Korea for utilization of public data as big data analysed by the application of 'scenario planning' as a foresight method. As a result, the future policy for utilization of public data as big data for national information with electronic government of S. Korea is to further spur the development of technology for linked data with semantic web for 'understanding of machine' than 'understanding of man'.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.11
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• pp.1297-1306
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• 2012

This work presents a 77 GHz radar transmitter for the automotive radar system. An integrated 13 GHz frequency synthesizer fabricated using 130 nm RF CMOS process drives a commercial W-band compound semiconductor monolithic multifunction amplifier(MPA), which includes a frequency multiplier by six to generate 77 GHz transmitting signal. The 13 GHz frequency synthesizer includes a high efficiency injection buffer of 4 dBm output power to drive the MPA. The output power of 77 GHz radar transmitter is higher than 13.99 dBm and the magnitude of the reference spur relative to the carrier is -36.45 dBc. The phase noise is -81 dBc/Hz at 1 MHz offset frequency from the carrier.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.6
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• pp.1245-1258
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• 2012

This study is about development of technology for electronic government of S. Korea with cloud computing analysed by the application of scenario planning. As a society of knowledge and information has been developed rapidly, because of changing from web environment to ubiquitous environment, a lot of countries across the world as well as S. Korea for e-Government have a variety of changes with cloud computing service. So this research focused on the strategy consulting of e-Government of S. Korea with development of cloud computing technology analysed by the application of 'scenario planning' as a foresight method. As a result, the future policy for development of cloud computing technology for electronic government of S. Korea is to further spur the development of technology for hard ware and internet data center as SLA(Service Level Agreement) and service provisioning, more improvement of level of technology with soft ware solution as resource virtualization, open API(Application Programming Interface).

• Korean Journal of Construction Engineering and Management
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• v.10 no.5
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• pp.104-112
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• 2009

After the middle of 90's, the eco rivers maintenance enterprise was propelled about city rivers. The environmental function is more emphasized because of revising the rivers law enforced at 2008.4. Also, the field of application is being magnified. It is difficult to apply that the conceptual public work expense estimating model of the rivers which adjusts a focus at open channel rivers excepts the small-scale rivers maintenance public work. The research presents a eco rivers public work conceptual public work expense estimating model frame work. It suits the change of the rivers environmental renewal construction paradigm. It develops the conceptual public work expense estimating plan of the rivers at the planning phase using the collection and analysis of the data. As a result, riffle, spur dyke, stepping stones, fish way and etc are added. Consequently, it brings the hydrophilic function is considered seriously conceptual public work expense estimating model of the eco rivers.

• BMB Reports
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• v.54 no.10
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• pp.534-539
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• 2021

IL-10⁺ regulatory B (Breg) cells play a vital role in regulating the immune responses in experimental autoimmune encephalomyelitis, colitis, and contact hypersensitivity (CHS). Several stimulants such as lipopolysaccharide (LPS), CD40 ligand, and IL-21 spur the activation and maturation of IL-10⁺ Breg cells, while the epigenetic mechanism for the IL-10 expression remains largely unknown. It is well accepted that the histone acetylation/deacetylation is an important mechanism that regulates the expression of IL-10. We found that entinostat, an HDAC inhibitor, stimulated the induction of IL-10⁺ Breg cells by LPS in vitro and the formation of IL-10⁺ Breg cells to suppress CHS in vivo. We further demonstrated that entinostat inhibited HDAC1 from binding to the proximal region of the IL-10 expression promoter in splenic B cells, followed by an increase in the binding of NF-κB p65, eventually enhancing the expression of IL-10 in Breg cells.

• Journal of Korean Society of Forest Science
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• v.108 no.1
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• pp.59-66
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• 2019

This study was conducted to evaluate the effect of the synthetic forest road network by calculating the optimal road density and layout of the forest road network in order to construct the systematic road network in the forested area. For this, five comparative routes were additionally planed and compared through evaluation indicators. As a result, the optimum road density of the study site was estimated to be 18.4 m/ha, and the synthetic forest road network was the best in the four indicators such as average skidding distance, standard deviation of skidding distance, development index, and circuity factor. In addition, the synthetic forest road network was comparable to the main road network by about 4 %p in the timber volume available and potential area size for logging, but the construction cost of the road was about 20 %p lower. It showed a synthetic forest road network was better in terms of economy.

• Journal of the Korean Society of Industry Convergence
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• v.22 no.1
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• pp.1-9
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• 2019

In electric agricultural machine the gearbox is used to increase torque and lower the output speed of the motor shaft. The gearbox consists of several shafts, helical gears and spur gears works in series. Optimization plays an important role in gear design as reducing the weight or volume of a gear set will increase its service life and improve the bearing capacity. In this paper the basic design parameters for gear like shaft diameter and face width are considered as the input variables. The bending stress and material volume is considered as the objective function. ANSYS was used to investigate the bending stress when the variable was changed. Artificial Neural Network (ANN) was used to obtain the mathematical model of the system based on the bending stress behaviour. The ANN was used since the output system is nonlinear. The Genetic Algorithm (GA)　technique of optimization is used to obtain the optimized values of shaft diameter and face width on the pinion based on the ANN mathematical model and the results are compared as that obtained using the traditional method. The ANN and GA were performed using MATLAB. The simulation results were shown that the proposed algorithm was successfully calculated the value of shaft diameter and face width to obtain the minimal bending stress and material volume of the gearbox.