• MALSORI
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• no.47
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• pp.141-151
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• 2003

The speech intelligibility of congenitally deafened children shows the change after cochlear implantation. The predicting factors of change in speech intelligibility are the age of implantation, the duration of implant use, and communication mode etc.. Among these factors, the age of implantation seems to be one of the most important predictors. But those factors including age of implantation can explain only some parts of the variance. Therefore, the further study to find the factors which affect the speech intelligibility should be done.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.18 no.35
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• pp.115-122
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• 1995

This paper is developed with software system for the construction of periodic maintenance. The system includes records of equipment, maintenance work, failure mode analysis and work standards of maintenability, inspection & repair to establish periodic maintenance system. And the software program is designed with user-oriented to analyze maintenance data and maintenance system of periodic interval times. Also machine operator can easily apply maintenance management system in production & manufacturing field. Visual Basic in the environment of Window system is used as computer program language for graphics and data base management in IBM PC.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.945-949
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• 2003

LIGA(Lithographie Galvanoformung Abformung), a fabrication method for the production of microstructrues with a high aspect ratio, is now playing an important role in a fabrication of polymeric optical waveguide device as the replication processes have been developed such as hot embossing and injection molding. The present report deals with the fabrication of Ni master used for the replication of multi-mode polymeric optical waveguide. With the basic technological features in the sequence of the LIGA technique, we fabricated Ni master with 12 channel microstructures of $100\;{\times}\;100{\mu}m\;^2{\times}\;60mm$, and achieved an accuracy of ${\pm}1\;{\mu}m$. Manufactured polymeric optical wavegude with the same using hot embossing process has also the same accuracy and approved its mass production capability.

• Journal of Korean Institute of Industrial Engineers
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• v.33 no.1
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• pp.164-165
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• 2007

• Journal of Theoretical and Applied Mechanics
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• v.3 no.1
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• pp.34-44
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• 2002

Theoretical analysis Is carried out to identify the modal coupling effect between some particular acoustic modes of a vehicle compartment cavity and vibration modes of body panels like side doors, roof or floor. A simplified panel-cavity coupled model is investigated on the coupled resonance frequencies, modes and frequency response characteristics. Through parametric study, It Is possible to explain how the acoustic response of a coupled system will be determined by the vibration and acoustic property of the individual panel and cavity system. Full coupled system shows some interesting features different from those of the semi-coupled system In frequency, mode and acoustic response.

• Proceedings of the Membrane Society of Korea Conference
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• 1994.03a
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• pp.1-21
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• 1994

There are growing needs to produce relatively high purity (99.0% or higher) oxygen at low cost. For small scale production, both pressure swing adsorption (PSA) and membrane process are competitve and less expensive or more convient than well known crygenic fractionation technology. A continuous membrane colume (CMC) combined with a PSA oxygen generator can be employed to produce high purity oxygen continuosly. The oxygen-enriched gas generated by a PSA unit, with a concentration of 93-94%, is fed to the CMC that consists of three modules of poly(imide) hollow fibers. Several experiments were conducted by varying parameters, such feed flow rate, transmenbrane pressure drop, stage cut, and feed location in order to obtain a high oxygen concentration above 99.0%. A two-series unit mode was also employed with CMC operation to optimize the given membrane area.

• Membrane Journal
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• v.4 no.1
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• pp.1-8
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• 1994

There are growing needs to produce relatively high purity(99.0% or higher) oxygen at low cost. For small scale production, both pressure swing adsorption(PSA) and membrane process are competitive and less expensive or more convenient than well known cryogenic fractionation technology. A continuous membrane column(CMC) combined with a PSA oxygen generator can be employed to produce high purity oxygen continuously. The oxygen enriched gas generated by a PSA unit, with a concentration of 93~94%, is fed to the CMC that consism of three modules of poly(imide) hollow fibers. Several experiments were conducted by varying parameters, such as feed flow rate, transmembrane pressure drop, stage cut, and feed location in order to obtain a high oxygen concentration above 99.0%. A two-series unit mode was also employed with CMC operation to optimize the given membrane area.

• Korean Journal of Environmental Agriculture
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• v.27 no.2
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• pp.145-149
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• 2008

Anaerobic co-digestion of swine manure and food waste for biogas production was performed in serum bottles at various volatile solids(VS) contents and mixing ratios of two substrates(swine manure:food waste=$100:0{\sim}0:100$). Through kinetic mode of surface methodology, the methane production was fitted to a Gompertz equation. The ultimate methane production potential of swine manure alone was lower than that of food waste regardless of VS contents. However, it was appeared that maximum methane production potentials in 80 : 20 of the mixing rate at VS 3% was enhanced at 144.7%, compared to its only swine manure. The potential increased up to 815.71 ml/g VS fed as VS concentration and food composition increased up to 3.0% and 20%, respectively. The ultimate amount of methane produced had significantly a positive relationship with that of methane yield rate. Overall, it would be strongly recommended that feeding stocks use 20% of mixing ratio of food waste based on VS 3% contents when operating the anaerobic reactor on site at $35^{\circ}C$ if not have treatment of its anaerobic waste water.

• Journal of Microbiology and Biotechnology
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• v.11 no.2
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• pp.229-233
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• 2001

Trichoderma reesei Rut C-30 produced high levels of ${\beta}$-glucosidase, endo-${\beta}$-glucosidase, endo-${\beta}$-1,4-glucanase, and exo-${\beta}$-1,4-glucanase. In pilot-scale production (50-1 fermentor), productivity and yield of CMCase (carborymethyl cellulose) and FPase (filter paper activity) were 273 U/ml and 35 U/ml, and 162 FPU/l.h and 437 FPU/g, respectively. The fed-batch techniques were used to improve enzyme activities with constant cell concentration. The acidity was an important parameter and controlled at pH 3.9 and 5.0 by automatic addition of ammonium hydroxide. Cellulase powder was prepared by ammonium sulfate precipitation and its CMCase and FPase activities were 3,631 U/g and 407 U/g, respectively.

• Journal of the Korea Safety Management & Science
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• v.7 no.1
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• pp.87-100
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• 2005

This paper studies on the quality problem for the Reley using the 6 sigma process. The application of 6 sigma process suggested reliable and valuable statistical data for the quality of the Relay at the production line. In the measurement step in 6 sigma process, the FMEA(filure mode effect analysis) were used for the detection of problem source. The application of 6 sigma process gave the improving method for the quality of the Relay. Consequently the 6 sigma process was proved very effective for the quality problem reducing at the production line.