• Elastomers and Composites
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• v.37 no.2
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• pp.107-114
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• 2002

This paper discusses the accelerated heat aging tests were carried out to predict the useful life of EPDM isolating rubber components of ventilation fan motor for clean room. 20% compression set results changes as the threshold are used for assessment of the useful life and the time to threshold value were plotted against reciprocal of absolute temperature to give the Arrhenius plot. The useful life at variable temperatures and activation energy are obtained from the Arrhenius relationship. An accelerated test program to assess useful life can be represented an appreciable investment in time was designed. We also considered the effect of antioxidant agents.

• Food Science and Industry
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• v.52 no.1
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• pp.20-31
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• 2019

Sensory perception of food/beverage products is one of the most important quality factors to determine consumer acceptability and thus sensory discrimination methodology has been a vital tool for quality management. Signal detection theory(SDT) and Thurstonian modeling provide the most advanced psychometric approach to modeling various discrimination methods. In these theories, perceptual and cognitive decisional factors are considered so that, a fundamental measure of sensory difference (d') can be computed, independent of test methods used. In this paper, sensory discrimination analysis based on SDT and Thurstonian modeling is introduced for more accurate and systematic applications of sensory and hedonic quality management in industry. Ways to realize the statistical power and relative sensitivity of sensory discrimination methods theorized in SDT and Thurstonian modeling in practice, are also discussed by using a case study of the Nongshim quality management program for drinking water in which SDT A-Not A test methodology was further optimized.

• Progress in Superconductivity and Cryogenics
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• v.11 no.3
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• pp.46-49
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• 2009

A 3-phase 100m long, 22.9kV class HTS power transmission cable system was developed by Korea Electrotechnology Research Institute (KERI) and LS cable Ltd. those are participated in the 21st Century Frontier project R&D Program of Korea. It is important to test the DC critical current related with its power capacity before applying to the real power grid. In 1995, several international standards organizations including International Electrotechnical Commission (IEC), decided to unify the use of statistical terms related with 'accuracy' or 'precision' in their standards. It was decided to use the word 'uncertainty' for all quantitative (associated with a number) statistical expressions. In this paper, we measured DC critical current of 22.9kV/50MVA superconducting power cable with several voltage tap and analyzed the uncertainty with these results.

• Journal of the Korean Solar Energy Society
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• v.26 no.4
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• pp.25-30
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• 2006

10kW wind turbine has been successfully commissioned at the King Sejong station in April, 2006. The wind turbine installed is a part of the R&D program for developing a solid wind/diesel hybrid power control system for a remote area such as Antarctica. At the same time, the current research aims to develop an anti-icing and de-icing technologies for a small wind turbine rated under 50kW. Since its commissioning, the turbine has generated about 500kWh for 47days without any system faults. Although sufficient data have not been obtained yet, any trouble has not occurred in the wind/diesel hybrid system based on the current analysis. Concerning on the environmental impact by the wind turbine operation, the turbine is installed within the station boundary in order to meet the Madrid protocol. Therefore, wind turbine operation meets the international requirements for preservation of antarctic ecosystem.

• Journal of the Korean Graphic Arts Communication Society
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• v.18 no.1
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• pp.1-11
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• 2000

The influence of the first coating layer on the properties of the second coating layer is reported. For various model coating composition, ratios of first and second coating weights are used to generate coating layers. The void volume, pore size distribution and light scatter coefficient of the coatings are measured. In some cases, the fine material from the second layer seems to penetrate the first layer to reduce the void fraction of the total system. Rapid setting coating, for example thin layers on porous first layer tends to generate porous coating layers.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1772-1774
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• 2004

Because the physics occurring during an interruption process is not well known, it is not easy to analyze the characteristics of a self-blast circuit breaker neither theoretically nor experimentally. Fortunately the available computational power and the numerical method improved recently make it possible to predict an interruption process as precisely and fast as possible. Therefore many researches using computational methods have been done for the interruption process of interrupters and applied to extend the information such as thermal and dielectric reignition. In this paper, we have simulated the interruption process of SF6 self-blast circuit breakers with the arc plasma during the fault interruption of a 10 kA current. The CFD program used here is coupled with the electromagnetic field analysis, the radiation model and the effects of turbulence. Through this work, we have get further information about the thermal performance as well as the behavior of the arc. The results have been compared with the measured arc voltage.

• Earthquakes and Structures
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• v.4 no.1
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• pp.41-62
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• 2013

A comprehensive experimental program of cyclic tests on 1:3-scale models of bridge piers is going to be carried out at the Laboratory of Structures and Materials of the University of Basilicata. The testing models include eight RC single shaft piers with hollow circular cross section. Four piers have been realised using corroded steel rebars. In this paper, the results of preliminary numerical simulation analyses of the cyclic behaviour of the piers, carried out with Opensees using fiber-based models, are presented. Pull-out and lap-splice effects of steel rebars have been taken into account in the numerical analyses. First, the experimental specimens and the test set up are presented. Next, the results of the numerical analyses are discussed. In the numerical analyses, different configurations and levels of corrosion have been considered. The effective stiffness and equivalent damping of the piers is reported as a function of pier ductility and pier drift.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.2
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• pp.157-162
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• 2014

The international COSPAS-SARSAT program is a satellite-based search and rescue distress alert detection and information distribution system and best known as the system that detects and locates emergency beacons activated by aircraft, ships and so on. However, the current message format of the system is not encrypted so that, if the rescue signal can be intercepted by the unintended receivers, the subsequent rescue activities can be handled in a hostile environment. So, this article concerns how to deal with the rescue signals in a secure way and proposes some adequate encryption methods and the corresponding key management.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.2
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• pp.157-163
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• 1997

This paper analyses a number of important areas relating to methane production in ruminants, consequent hazards and different methods of reducing this gas. Clearly methane not only affects on the environment but also on the economy of animal production. Several factors including feed, species, microbes, rumen environment, etc. are responsible for methane production in animals. Although methane production can be reduced by chemical manipulation, defaunation and strategic feeding, the latter was found to be effective because the method is easier to follow than the others. Furthermore, feeding technology could play an important role in reducing methane production particularly in developing countries because of its relative cost effectiveness. however, it needs to compare to what extent it could reduce methane production as well as cost of animal production. Therefore, research program needs to be concentrated on the appropriate feeding system to reduce methane production, consequently pollution and cost of production particularly in developing countries.

• Electronics and Telecommunications Trends
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• v.12 no.6 s.48
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• pp.110-121
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• 1997

정보통신연구개발사업은 정부연구개발사업 전체에서 차지하는 비중이 작지 않음에도 불구하고, 이에 대한 연구는 매우 미흡하여 사업의 변천과정이나 추진현황과 같은 기본적인 사항조차도 부정확하게 알려져 있는 실정이다. 이에 따라 본 연구는 1977년 이래에 수행된 정보통신 분야의 연구개발사업의 변천과정을 시대별과 재원별로 구분하여 분석하고, "정보통신연구개발사업"으로 통합된 1993년 이후에는 공공출연 연구개발사업과 정보화촉진기금 융자 연구개발사업의 2개 사업으로 분류하여 추진현황을 분석하였다. 이러한 분석결과를 통해 본 연구는 정보통신연구개발사업에 대한 기존 연구의 일부 오류를 시정함은 물론 관련 정책결정자나 사업관리자들에게 유용한 기초자료를 제공할 수 있을 것으로 기대된다.