• Journal of the Korean Electrochemical Society
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• v.11 no.1
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• pp.22-32
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• 2008

Because of an emerging importance of clean energy, fuel cells are attract more attention due to their ability to produce high efficient power without any harmful emission. Fuel cells are energy conversion device with directly convert chemical energy into electrical energy by the chemical reactions, which have potential applications in automobile, spacecraft, stationary, industrial and home appliances. Recently there are gaining demand to develop an intermediate temperature fuel cell and available proton conductors at $200{\sim}500^{\circ}C$, which promising operating temperatures range for both material science and energy conversion processes. In this paper, we have reviewed electrochemical properties and current technology of solid state proton conductors. In addition, development of intermediate temperature fuel cell using the perovskite-type solid protonic conductor is also discussed.

• Archives of design research
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• v.15 no.1
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• pp.407-414
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• 2002

Human does information processing more efficiently using mental model at his understanding process. if We know what mental model is, we will know how to percept that. Similarly is it used visual mental model to percept visual object\ulcorner If it is true, we will analysis how man to understand. In this research, we have one experimentation to timid out that is true. So we did experimentation to know how man to understand new products by visual mental model. So we use 2700cc car's side view as stimuli. To A Subjects, we give them to see re\ulcorner size view before 120% ratio. To B Subject, we give them to see 120% ratio. After a experimentation, It is true that we make hypothesis that A Subjects percept this stimuli too long then B Subjects. Accordingly it proves human to use visual mental model to percept visual object. The result of experimentation, a testee use preliminary stimulus as basis of evaluation. It means that he use mental model as basis of evaluation of main stimulus. Accordingly development of new design can afford more strategic approach. Industrial designer who want to strategic approach can forced on high-weighted form attribute as consumer gives.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.2
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• pp.42-48
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• 2005

A DC-DC converter is being widely used for various household appliances and for industry applications. The DC-CC converter is powered from single battery, and the voltage is varied according to the purpose. In the vehicle, various accessories whose electric power is different are being un4 Thus, plural number of DC-DC converter should be provided, so these situations bring complicated circuits, and accordingly, higher cost. Under such backgrounds, in this paper, we propose a novel buck-boost chopper circuit with simply configuration which can supply to two or more different output loads. The propose chewer circuit can control output voltages by controlling duty ratio by using typically two switching devices, which is composed by single boost-switch and single buck-switch. The output voltage can be controlled widely. A few modified circuits developed from the fundamental circuit are represented including the general multi-load circuit. And all this merits and appropriateness was proved by computer simulation and experience.

• Journal of the Korean Regional Science Association
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• v.32 no.3
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• pp.45-62
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• 2016

The main purpose of this study is to investigate whether the gap of fiscal self-sufficiency rates of 16 provincial governments in Korea has been narrowed and to suggest some remedies based on the empirical results. The panel data set from 1998 to 2013 is used and pooled OLS and system GMM regression techniques are employed. The fiscal self-sufficiency rates show downward trend and ${\beta}-convergence$ exists in absolute and conditional convergence analysis. The speed of conditional convergence anlysis is proved to be faster than that of absolute analysis. Both metropolitan cities and prefectures show convergence of fiscal self-sufficiency rates. We have found out that in the case of metropolitan cities, the proportion of workers in the tertiary industry has positive effect on fiscal self-sufficiency rates and in the case of prefectures number of cars per capita has positive effect. And in both cases increase in old population has negative effect.

• Korean Business Review
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• v.14
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• pp.169-187
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• 2001

In the recent efficiency study became accomplished generally a listed company, the efficiency study of small manufacturing industry is deficient. The purpose of this study analysis efficiency of small manufacturing industry by using the DEA model. DEA model is non-financial approach method to measure relative efficiency by input factors and output. The panel data from 1996 to 1999 are used for the analysis. The relative mean-efficiency can be summarized as follows. The wholesale trade and commission trade manufacturing industry 68.99%, communication equipment manufacturing industry 60.58%, food products and beverages manufacturing industry 91.05%, motor vehicles, trailers and semitrailers manufacturing industry 85.80%, basic metals manufacturing industry 88.96%, pulp, paper and paper products manufacturing industry 96.53%, chemical and chemical products manufacturing industry appeared with 78.67%. The results is expected to provide the empirical evidence useful to enhancing the competitiveness of manufacturing industry in korea.

• Elastomers and Composites
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• v.46 no.1
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• pp.29-36
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• 2011

The term 'thermal insulating materials' describes a class of materials which can improve the thermal efficiency by reducing the thermal conduction, convention and radiation between the inside and outside of the system. As a thermal insulating material, numerous industrial applications are possible including the automobile, aerospace, aviation, and petrochemical. Especially, the silica aerogel, with their superior thermal insulating behavior, has been widely used as thermal insulating materials. Because the mechanical properties of the silica aerogel cannot meet the industrial demand, use of the silica aerogel is limited. This article aims to review the thermal insulating materials and silica aerogel, and to introduce the silica aerogel/polymer composites.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.3
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• pp.687-704
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• 2017

As Korea's industrial competitiveness and technological prowess increase, collaboration and technical exchanges with contracting companies are increasing. In an environment where cooperation with the contracting company is unavoidable ordering companies are also striving to prevent leakage of technologies through various security systems, policy-making and security checks. However, although the contracting companies were assessed to have a high level of security management the leakage of technical datas are steadily increasing. Issues are being raised about the effectiveness of the security management assessment and the actual security management levels. Therefore, this study suggested a security management system model to improve security management efficiency in the general contract structure. To prove this, analyze the efficiency of 36 contractor companies for the technical datas security management system using the DEA model. The results of the analysis are reflected in the assessment results. Lastly, suggestions for improving the effectiveness of the technical datas security system are proposed.

• Smart Media Journal
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• v.6 no.3
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• pp.15-20
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• 2017

Recently, the automotive industry has been studied about driver assistance systems for helping drivers to drive their cars easily by integrating them with the IT technology. This study suggests a method of detecting lanes, robust to road condition changes and applicable to lane departure warning and autonomous vehicles mode. The proposed method uses the method of detecting candidate areas by using the Gaussian filter and by determining the Otsu threshold value and edge. Moreover, the proposed method uses lane gradient and width information through the Hough transform to detect lanes. The method uses road lane information detected before to detect dashed lines as well as solid lines, calculates routes in which the lanes will be located in the next frame to draw virtual lanes. The proposed algorithm was identified to be able to detect lanes in both dashed- and solid-line situations, and implement real-time processing where applied to Raspberry Pi 2 which is open source hardware.

• Resources Recycling
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• v.23 no.4
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• pp.30-36
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• 2014

300,000 tons of waste tires are annually being produced with development of the automotive industry in Korea. Landfill and incineration treatment system are causing the economic problem through secondary environmental pollution and waste. Therefore, as one of the ways to take advantage of this, Thermo-Plastic Vulcanized (TPV) composite was prepared by the ground waste tire and plastic powders. The waste tire powder was gained by mechanical fracturing through crushers. The waste tire powder was ground by a shear crushing method and a 2-stage disk mill method instead of cutting crushing one. The waste tire powder of 50 mesh was mixed with Polypropylene(PP) in various proportions. TPVs were prepared by an extrusion, and tensile and impact tests were performed. In addition, the same experiments were repeated in 40, 80, 140 mesh conditions in order to observe size effect of waste tire powders.

• Composites Research
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• v.34 no.5
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• pp.269-276
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• 2021

PCM (Prepreg Compression Molding) process is a high-speed molding technology that can manufacture high-quality CFRP (Carbon Fiber Reinforced Plastic) parts. Compared to the autoclave process, it generates less waste and can significantly reduce cycle time, so various studies are being conducted in the aerospace and automobile industries. In this study, in order to improve the quality of the PCM process, a molding method was developed to increase the compression pressure of the press step by step according to the curing behavior of the prepreg. It was confirmed that this multi-stage compression molding technology is a good means to produce high-quality CFRP products and shorten cycle times. And, the laminated prepreg at room temperature was immediately put into the mold and preheated and molded at the same time, so that it could be molded without a separate preheating process. In addition, as a result of applying the same process conditions optimized for flat plate molding to three-dimensional shapes, a product similar to a flat plate in appearance could be made without the process of establishing process conditions.