• Carbon letters
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• v.14 no.2
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• pp.117-120
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• 2013

In this study, an electro-catalyst of Pt nanoparticles supported by polypyrrole-functionalized graphene (Pt/PPy-reduced graphene oxide [RGO]) is reported. The Pt nanoparticles are deposited on the PPy-RGO composite by chemical reduction of H2PtCl6 using NaBH4. The presence of graphene (RGO) caused higher activity. This might have been due to increased electro-chemically accessible surface areas, increased electronic conductivity, and easier charge-transfer at polymer-electrolyte interfaces, allowing higher dispersion and utilization of the deposited Pt nano-particles. Microstructure, morphology and crystallinity of the synthesized materials were investigated using X-ray diffraction and transmission electron microscopy. The results showed successful deposition of Pt nano-particles, with crystallite size of about 2.7 nm, on the PPy-RGO support film. Catalytic activity for methanol electro-oxidation in fuel cells was investigated using cyclic voltammetry. The fundamental electrochemical test results indicated that the electro-catalytic activity, for methanol oxidation, of the Pt/PPy-RGO combination was much better than for commercial catalyst.

• Proceedings of the Korea Concrete Institute Conference
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• 1995.04a
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• pp.189-194
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• 1995

This paper presents the material properties and production of 500 and 700 kg/$\textrm{cm}^2$ high strength concrete for the practical utilization. A series of Lab. tests were conducted to optimize the material mixture of high strength concrete and then mock-up tests were performed through the Remicon Batch Plant. This paper stresses the material conditions for the final stage of production of 500 and 700 kg/$\textrm{cm}^2$ high strength concrete, just prior to the practical use on 28-story Samsung Shin-Daebang Housing-Commercial Combined Building with 8-story basements.

• Proceedings of the Korea Concrete Institute Conference
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• 1995.04a
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• pp.195-200
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• 1995

This paper presents the practical use of high strength concrete on 28-story Samsung Shin-dacbang Housing-Commercial Combined Building with 8-story basements located in Seoul. 700 Kg/$\textrm{cm}^2$ compressive Strength concrete was placed for basement core-walls and 500 kg/$\textrm{cm}^2$ concrete was used for structural frames up to 10th floor. The thermal sensors were installed prior to concrete casting into the core walls to measure the heat of hydration during hardening process. The correlation of core strength to the standard cylinder test strength was also discussed. The successful utilization of 500 and 700 kg/$\textrm{cm}^2$ concrete shows that the practical application of high strength concrete has a great potential to the high-rise R.C building construction.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.9
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• pp.47-56
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• 2007

This paper presents novel topologies implementation for Switched Reluctance Motor(SRM) drive used in commercial applications. For effective utilization of the developed system, a novel direct current controlled PWM scheme is designed and implemented to produce the desired dynamic speed characteristic. In comparison to conventional asymmetric converter topology, it can minimize entire system costs by reducing numbers of power semiconductors. Therefore, it may open up investigation of a new way for SRM to compete with other ac motors such as induction motors, brushless dc motors, etc. The validity of the proposed method is verified through theoretical explanation and experimental results.

• Journal of the Korean housing association
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• v.12 no.4
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• pp.105-113
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• 2001

This research indicates to controversial point that store equipments were not applying correct development factor in the each apartment house by that change rate by scale and uniformity of form and inefficiency, effect of discount store is increasing in apartment house and progressed research. The result are as follows; First, interior main point of store of that influence greatly to change rate number of store be. Second, being lot area in jar in outside factor of store. Third, discount store separation appeared by leading person who influence greatly to change rate in middle who is contiguity market singleness residential quarter and contiguity existence of commercial district and nonexistence and discount store separation of only outside right near at hand. Construction of commerce equipment may have to consist in practical apartment house after examine various kinds factor such as store indoor, store outside and only outside while plan practical use of systematic and efficient commerce equipment focusing more in efficient utilization of commerce institution that consist after plan that is not planed commerce equipment focusing in development in plan of commerce equipment in apartment house hereafter accordingly.

• The Transactions of the Korea Information Processing Society
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• v.6 no.11S
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• pp.3278-3288
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• 1999

This paper proposes a security platform, called SCAP(Security platform for CORBA based APplication), to cope with potential threats in a distributed object system. SCAP supports CORBA security specification announced by OMG. SCAP is comprised of four functional blocks, which co-work with ORB to provide security services: Authentication Block, Association Block, Access Control Block, and Security Information Management Block. It is designed to support Common Secure Interoperability Functionality Level 2, which is useful for large-scale intra-, or inter-network based applications. Actual security services, which are dependent on supporting security technology, will be provided as external security service for replace ability. Implementation issues such as how to simulate an interceptor mechanism using a commercial ORB product without source code, and how to extend Current object required for security services are also described. At the end of the paper, the SCAP applied to the web environment is described to show its practical utilization.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.3
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• pp.303-309
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• 2009

Switched Reluctance Motor(SRM) has become popular for industrial application, particularly for low medium drives due to the advantages of SRM over the other ac motors: SRM can be manufactured with low cost because it has a simple structure. But, asymmetric bridge converter that generally is used for driving requires two discrete switching devices and freewheeling diodes per phase, and cause the SRM drives to be complicated and to increase the cost of overall system. Therefore, this paper suggests a new type of 4-switch converter for SRM. 4-switch converter topology is studied to provide a possibility for the realization of low cost 3-phase SRM drive system. For effective utilization of the developed system, a new current control algorithm is designed and implemented to produce the desired dynamic performance. With the developed power conversion circuit and control scheme, it is expected that the proposed system can be widely used in commercial applications with reduced system cost.

• Explosives and Blasting
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• v.16 no.3
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• pp.35-48
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• 1998

An overview of the plasma rock fragmentation system, the first commercial application of plasma blasting, is presented. Plasma blasting is based on the fast delivery of stored electrical energy to fracture the rock. The capacitor bank, switching device, cable and blasting electrode employed in the system are described. Utilization of the chemical energy delivered from the electrolyte and the development of a large charge transfer switch using pseudospark enabled the commerciailzaion. The vibration and noise level of the blasting is acceptable in the most ground breaking.

• IE interfaces
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• v.1 no.1
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• pp.63-72
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• 1988

Since many small and medium sized enterprises in Korea have lack of funds to install a commercial computer packages for work standards and work scheduling. This study has been attempted to develop the computer-generated package to ease those problems. The system consisted of three major parts. The first part is a work measurement program applying W.F.(work factor) predetermined time standards for work standards. The second part is a work scheduling program which calculates each operator's machine and job allocation. The last part is a control program for the production outputs and the machine utilization monitoring. The system is programmed by dBASE III for the IBM-PC compatibles for the sake of user's conveniences.

• 한국연소학회:학술대회논문집
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• 1999.10a
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• pp.165-172
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• 1999

Landfill gas has merely half heating value compared with liquified natural gas but can be greatly utilized as a commercial fuel. The authors have examined emission characteristics as well as measured burning velocity of LFG mixed gas which contains plenty of $CO_{2}$. With the viewpoint of fuel utilization, flame stability could be one of important characteristics of LFG. In this study, the comparison experiments are conducted between $CH_{4}$ and LFG for searching the region of flame stabilization based upon the flame blowout at maximum fuel stream velocity. As a result, it is found that stabilization region of LFG is not improved with that of $CH_{4}$ in non-swirl/or weak swirl jet diffusion flame. However, it is also known that flame stability is hardly affected by inert gas in the strong swirl with considering widened flame stabilization region of LFG rather than LNG.