• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.222-223
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• 2018

Recent government policies are increasing interest in zero-energy housing, a building that minimizes energy consumption (90% reduction). As the importance of building passive performance is emphasized, the role of insulation is increasing as a way to reduce indoor heat loss in order to minimize the use of cooling and heating energy. There are two main types of insulation. Organic insulation is widely used for various construction structures such as construction and industrial due to some merits such as the convenience of construction and construction cost. However, it has been pointed out as a main cause every time a fire accident occurs, Jecheon Sports Center', the fire damage of buildings caused by the use of organic insulation materials is expanding to social problems, so it is urgent to research on nonflammable inorganic insulation materials.

• Journal of The Korean Digital Architecture Interior Association
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• v.12 no.3
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• pp.27-38
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• 2012

The purpose of this study is to analysis the concept of location efficiency, a base for the qualitative evaluation of TOD, and to propose the method of urban design for the improvement of location efficiency. Because of the environmental crisis by urbanization, sprawl and global warming, the importance of the solution through TOD has been increasing. For the future development of TOD, it becomes important to evaluate TOD qualitatively. From the study, it is grasped that location efficiency contains the concepts of value recapture, QoL and choice, financial return, and efficient regional land use and patterns. And the method of urban design for location efficiency is proposed as the followings: Form Based Zoning as land use plan, TOD and TOC model as node function, and street systems, mixed-use development, characteristic housing with various types, and networking of neighborhood facilities as place function.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.11
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• pp.1001-1007
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• 2003

The silicone fluids have been generally used as processing agent in silicone rubber(SIR) compounding. The addition of hydroxy silicone (HS) fluids to SIR for insulator housing material is required to meet the good electrical performance and the good processability. In this study, SIR with HS fluids was evaluated to investigate how the kinds of them affect insulation properties. The contact angle of the virgin sample of 40-HS SIR was low and its recovery rate was also slow. The recovery rate of 50-HS SIR was the highest being decreased with the viscosity increase of HS fluids. The tracking resistances and the corona aging resistance of 70-HS SIR and 1,040-HS SIR were excellent Tracking resistance depended largely on heat resistance of silicone fluids. But arc resistance didn't depend merely on the kind of silicone fluids.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.8
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• pp.691-696
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• 2007

In this study accelerated aging test equipment was developed to simulate domestic weather condition for accelerated aging test of polymer housed distribution surge arresters. Polymer arresters were aged for 3,000 hours by this test equipment and chemical and electrical characteristics analysis of surge arresters were conducted after aging test. In addition, performance assessment of outdoor installed arresters for 3 years was conducted to compare aging effect between accelerated aging test and natural aging. Through this experiment it is verified that the capability of the proposed aging test for simulating natural aging and the housing material and disconnector of domestic polymer arresters can be deteriorated by the long time field operation.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.11
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• pp.799-805
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• 2012

In this study, structural thermal analyses for steam trap valve considering contact boundary condition have been conducted for high temperature and pressure conditions using nonlinear finite element method. Full steam trap model also including regulator and housing structures is considered in order to accurately simulate the complex valve mechanism and investigate thermal stress levels, and structural behaviors of core structural parts. It is typically shown that the present computational approach can give very useful results for design engineers so that the operating performance and structural safety of the steam trap valve can be verified in the design process.

• Communications for Statistical Applications and Methods
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• v.24 no.6
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• pp.651-662
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• 2017

We propose an alternative procedure to select penalty parameter in $L_1$ penalized robust regression. This procedure is based on marginalization of prior distribution over the penalty parameter. Thus, resulting objective function does not include the penalty parameter due to marginalizing it out. In addition, its estimating algorithm automatically chooses a penalty parameter using the previous estimate of regression coefficients. The proposed approach bypasses cross validation as well as saves computing time. Variable-wise penalization also performs best in prediction and variable selection perspectives. Numerical studies using simulation data demonstrate the performance of our proposals. The proposed methods are applied to Boston housing data. Through simulation study and real data application we demonstrate that our proposals are competitive to or much better than cross-validation in prediction, variable selection, and computing time perspectives.

• Proceedings of the KIEE Conference
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• 1997.07a
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• pp.303-305
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• 1997

The advantage of application polymer instead of conventional porcelain as the housing material for arrester is that light weight, shorter section length of arrester would be possible due to the use of an insulated hanger (mold compound). also, polymer arrester has very good characteristics in design versatility as well as excellent resistance to moist ingress and pollution performance. The finite element method is widely used to calculate for electromagnetic devices. In this paper, we perform the each conditional analysis of PC with an advanced graphical user interface(GUI) using the vector fields simulator. And we try to analyze electromagnetic fields through the conventional two dimensional analysis in case of high voltage contamination on the electrode of a arrester.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.214-217
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• 1999

Polymeric composite insulators have been in use for outdoor insulation. However, our knowledge about their long-term performance in a outdoor environment is still very limited. Especially, these insulator are subjected to the environmental stress such as ultraviolet radiation. Hence, in this paper. the influence of UV radiation on the aging of the shed materials was evaluated. For the aging evaluation, these insulators studied by experiment methods such as contact angle measurement. oxidation induced time. SEM/EDX, FTRI-ATR, tracking test for the different insulator samples. With the increased UV exposure time, samples are shown to exhibit degradation comparable to those of new ones

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.11a
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• pp.224-225
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• 2014

In recent years, the domestic construction business is continuously stagnated caused by housing depression, global financial crisis etc. To overcome these difficulties, the construction companies should reinforce the internal marketing like the service business. However, it is not easy to conduct active internal marketing reinforcement since the companies do not directly receive customers under special situation like construction. Therefore, it is necessary to resolve the urgent issue by selecting order of priority among internal marketing factors. To address this issue, the objective of this study is to analysis the internal marking factors by using Analytic Hierarchy Process.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.5
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• pp.53-59
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• 2001

A screw driver is widely used in assembling machine parts or electronic products such as the printed circuit board with a housing. As the parts to be assembled becomes small and precise, the higher precision of the controlling screw driver torque is required. However, because the operator controls the fastening torque based on experience, it must be inexact and the setting procedure will be time consuming job. Thus the screw driver which can exactly control the fastening torque is developed utilizing a bellows in this paper. The bellows is expanded by the inner air pressure and contracted by the spring operation. The bellows type driver is composed of a clutch mechanism with two solenoid valves and a pressure sensor. Those valves are controlled using the detected bellows pressure by the sensor. When the pressure reaches the setting value, the exit solenoid valve is opened to release the air pressure from the bellows so as not to deliver further torque. Through a series of experiments, the performance is examined and verified.