• Journal of the Korean Society of Safety
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• v.16 no.2
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• pp.63-68
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• 2001

In this study the main elements which can be commonly adopted to every kind of business are selected through the research, case-study, benchmarking common items of a direct or indirect loss cost. As a result of the development of a program for evaluating loss cost a case or accumulated data can be easily managed through estimating the direct and indirect loss cost as tell as the ratio between directs and indirect cost. The program is fit to case-study and we are compared direct cost with indirect cost. Automatically, this program showed ratio between directs and indirect cost for style, scale of accident The person in charge of safety and hygiene can have better chances to get into management also the owner or the CEO can recognize the importance of management of safety and hygiene. So this can guide the company to invest in a prevention of disaster and to adopt a safety and hygiene management promote the prevention activity of a company, and finally decrease the accident rate in the country.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.7
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• pp.550-554
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• 2013

Carbon nanotubes (CNT) / polyvinylidene fluoride (PVDF) piezoelectric composite films for nanogenerator devices were fabricated by spray coating method. When the CNT/PVDF mixture solution passes through the spray nozzle with small diameter by the compressed nitrogen gas, electric charges are generated in the liquid by a triboelectric effect. Then randomly distributed ${\beta}$ phase PVDF film could be re-oriented by the electric field resulting from the accumulated electrical charges, and might be resulted in extremely one-directionally aligned ${\beta}$ phase PVDF film without additional electric field for poling. X-ray diffraction patterns were used to investigate crystal structure of the CNT/PVDF composite films. It was confirmed that they revealed extremely large portion of the ${\beta}$ phase PVDF crystalline in the film. Therefore we could obtain the poled CNT/PVDF piezoelectric composite films by the spray coating method without additional poling process.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.601-604
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• 1993

The effect of an insulator inserted along the axis of a red-to-plane gap on an ion flow field in $SF_6$ gas is investigated experimentally in the pressure region where a proceeding corona discharge exists. Without the insulator, the calculated electric field on the plane electrode agrees fairly well with the measured one. With the insulator, the ion flow field characteirstics may be attributed to the change in the electric field distribution by the accumulated charge, the increase in the ratio of the dielectric strength in gas gap to that along the insulator surface with the gas pressure, and the thermal diffusion of ions near the insulator.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.405-408
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• 2004

In this work, Analytical model for voltage and current characteristics of NPT(Non-PunchThrough) IGBT(Insulated Gate Bipolar Transistor) was represented. voltage and current characteristics models were based on prediction on power loss of NPT IGBT during transient condition. For Analytical current model, excess carrier concentration and accumulated charge in active base width was analyzed with time variance. Analytical models were simulated by varying lifetime of excess minority carrier.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.4
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• pp.477-483
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• 2007

A coagulation process for RO (reverse osmosis) membrane pretreatment system was an effective technology to remove colloidal and particulate matters. However, coagulant residuals from the pretreatment process may negatively affect RO membrane performance. The bench-scale coagulant exposure study was performed to investigate the effect of their residual on adsorbed mass which related to the membrane performance. Coagulant addition in this study ranged from 0 to 5mg/L ferric chloride, alum, and 2mg/L cationic polymer(poly-di-methyldiallyl ammonium chloride) as coagulant aids. This results showed that adsorbed mass is not significantly increased during short-time period, however, accumulated mass of coagulants on the membrane surface is significantly increased during long-time experimental period. The effect of pH on coagulants adsorption characteristics was significantly differed due to the electrostatic repulsive interactions between soluble coagulants and membrane surface charge. This data suggest that the RO membrane performance of drinking water treatment plant could be decreased by adsorption of residual coagulants when applied for the coagulant pretreatment process.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.17 no.1
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• pp.30-34
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• 2007

[ $TiO_2/PVP$ ] nanofibers were electrospun by varying the collector grounding design to improve the axial alignment of fibers. The collectors are composed of two pieces of conductive substrates separated by a gap f3r the uniaxial alignment of fibers (X design). The collectors consisting of two sets of substrates placed by $90^{\circ}$ (XY design) equipped with a timer are also prepared for biaxial alignment of fibers. Both collectors show that the charged nanofibers are stretched to span across the gap between the electrodes. Experimental results reveal that the latter collector is more effective on the directionality of electrospun $TiO_2/PVP$ nanofibers due to the dissipation of accumulated electric charge between the collectors.

• The Journal of the Korea Contents Association
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• v.9 no.7
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• pp.121-129
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• 2009

Inspection of an Electrical Meter is an action of measuring power usage to charge electricity rates and Electricity AMR(Automatic Meter Reading) is a system to automatize the action. AMR has been highlighted because it can reduce metering cost by substituting an automatic system for personnel and strengthen customer service. In this paper, we proposed and developed a smart card based AMR framework SCEMS as an alternative to other current AMR Models. This proposed SCEMS uses a java card based multi-application smart card and supports customer service such as various meter rates according to electricity consumption pattern data per household and transaction data that are accumulated in a smart card. This research can be a solution to the problems such as diversity, heterogeneity, and complexity that environmental changes will cause soon to the power supply industry.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.756-760
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• 2005

By development of a robot technology, personal robot is being developed very actively. Various infra-technologies are accumulated in hardware and software how by internal a lot of research and development efforts, and it is circumstance that actual commodity is announced. But, personal robot is applied to be acting near human, and takes charge of safety and connected directly a lot of works of home security, gas-leakage, fire-warning facilities, or/and etc. So personal robot must do safe and stable action even if any unexpected accidents are happened, important functions are always operated. In this paper, we are wished to show design structures for supporting fault-tolerant operation from our real-time robot middleware viewpoint. Personal robot, in being developed, was designed by module structure to do to interconnect and to interoperate among each module that is mutually implemented by each research facilities or company. Also, each modules can use appreciate network system that is fit for handling and communicating its data. To guarantee this, we have being developed a real-time network middleware, for especially personal robot. Recent our working is to add and to adjust some functions like connection management, distributed routing mechanism, remote object management, and making platform independent robot application execution environment with self-moving of robot application, for fault-tolerant personal robot.

• Spatial Information Research
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• v.12 no.1
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• pp.1-12
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• 2004

The 3-dimensional GIS data provider system manages and retrieves 2, 3-dimensional spatial and time data. This system provides the standard interfaces which help developers to omit additional works to do modify or convert a format of 2 or 3-dimensional spatial data, which has been already accumulated, into that dependent on a specified system. This system consists of a data provider and data access component. The former deals with the connections with some databases and manages the meta data, so that the various GIS or software can access to 3-dimensional spatial and time data via the same method, and the latter takes charge of index management and spatial operations on GIS data for consumers. The system offers the diverse spatial operations and analysis functions for 3-dimensional GIS.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.263-269
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• 2012

Condition-based maintenance (CBM) has been used as a useful concept for optimizing maintenance plan and decreasing maintenance cost in several kinds of plant sites. This study introduced an example that developed an integrated management system for maintenance parameters and hydraulic turbine of hydro-power plant in order to improve its maintenance system as applying CBM techinique. The integrated management system consists of three parts. One is a hardware part including PDA inspection system and several kind of precision measuring instruments. Another is a vibration monitoring system on hydraulic turbine. The other is a software part that takes charge of making hierarchy tree of maintenance parameters and their inspection route, managing accumulated database, assessing health condition of components, and supporting interface with other enterprise management system. The system has been installed at Chuncheon Hydro-power plant for test and demonstration. It is expected that the system can contribute database construction for diagnostics and prognostics on facility health condition and systematic accumulation of know-how on operation and maintenance of plant.