• Speech Sciences
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• v.14 no.2
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• pp.65-71
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• 2007

The severe-profound hearing impaired children have various disorders in everday communication due to the lack of hearing feedback. Especially, their speech produced unstable voice, omission and distortion of articulation, pitch break, cul-de-sac voice, and so on so that they were difficult to accurately deliver an intended message. This study attempts to analyze the acoustic characteristics of 4 vowel sounds produced by 35 severe-profound hearing impaired children using CSL(Computerized Speech Lab, Model 4300b). The formant data were obtained from the spectrogram and analyzed data by 12 formant filter and auto-correlation among the formants. Results showed that the hearing impaired children's formant values came out very high. They produced the vowels at the mode of hypertension with unstable voice. In order to improve their speech, they would need some adequate auditory feedback.

• Journal of the Korea Safety Management & Science
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• v.4 no.3
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• pp.67-78
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• 2002

Automated manufacturing systems are applied to shop floors as tools for increase of productivity and quality and the decrease of manufacturing lead times and industry accidents. One of the most important issue of the present day is the application of Internet. The development of Internet technologies makes manufacturing enterprises break spacial barriers between users and shop floors, and collect various field data in remote sites. In this research, an Internet-based remote control system for a small-sized automated storage and retrieval system is developed for the purpose of real-time monitoring and control of automatic production equipment. The developed system has a client-server architecture and sends real-time images of the automated storage and retrieval system to clients by an CCD camera connected to a server.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.238-244
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• 2006

The Light Collision Safety Device is used to protect the important part of trains and passengers at the low velocity accidents. The Light Collision Safety Device comprises mainly tension bolts, shear bolts and an energy absorber. The work mechanism of this device is that first, the tension bolts break at designed collapse load and second, the energy absorber absorb rest collision energy. In this paper, the tension bolt characteristics were validated by the simple tension test using the FEM(Finite Element Method) and the characteristic of the two types of energy absorber were compared by using the load-displacement curves and absorbed energy. Last, in order to determine integrated load-displacement curve of tension bolts and the energy absorber, the unified analysis was conducted by using the FEM.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.7
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• pp.268-277
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• 1999

In order to make an advanced dry-friction engineering material, wax-impregnated nylons were synthesized by anionic polymerization of $\varepsilon$-caprolactam in the presence of apraffin wax. DNX-125S, which has lowest melting point among four different kinds of waxs investigated, showed excellent miscibiility with $\varepsilon$-carprolactam and no effect on the polymerization reaction. Five different kinds of wax-impregnated nylons from of DNW-125S content 0% to 8% were synthesized and tested. Among the samples, wax-free nylon has the highest yield and tensile strength and hardness, while the specimen with2% wax has the largest elongationi and energy absorption to break. The wax-impregnated nylon with a wax content 6% showdd the smallest friction coefficient under slow sliding speed and low load. Bus as the sliding speeds were increased to high, thespcieimen with 8% wax has better friction property.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2002.11a
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• pp.197-201
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• 2002

The purpose of this study is to provide the information of street planning for revitalization oft the community in urban detached housing area. This study was accomplished by observations and actual survey, and suggested several street planning methods; exclusion of the passing through car and control of the resident's car by one-way passage, protection of the parking area to inside individual lot by the ‘Break down Fence’ campaign in Daegu, and provide the common space for social contact and community According to this program, the public street space cant be changed into the semi-private space and the semi-public space as common territory.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2005.11a
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• pp.295-300
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• 2005

This Study intends to find out the subjective symptom of Construction Business Worker caused by chemical material exposure, also willing to research how much they are exposed to VOCs(Volatile Organic Compounds) and under how much harmful circumstance they are working. As the results, the job group among construction business workers which is most highly dangerous degree to be taken ill of Multiple Chemical Sensitivity is Interior Worker, next following by order of Clerical Worker, Exterior Worker. According to this result, the continuous exposure in high density must be prevented by the measures for Interior Worker also to be bestowed a compulsory break during working hour for regular exposure to the open air,

• Journal of Ocean Engineering and Technology
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• v.14 no.2
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• pp.44-52
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• 2000

The dispersion of surface oil is generally described as a break-up of oil slick into small oil droplets. These small droplets are subjected to turbulence and vertical circulation so that it can be entrained into subsurface. Sometimes they tend to be submerged into sea bottom permanently. The diameter of oil droplets is a critical parameter to determine their behavioral characteristics under water surface. At the same time the variations of droplet stability depends on the weathering of it. That is why the weathered oil has different mechanism from the unweathered one. The variability of physical properties of oil including viscosity and density contribute to interfere with effective separation of oil and emulsion droplets in water. Also in the presence of interactions among the droplets there are coalescing or coagulating effects on the dispersion process of droplets.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.1275-1277
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• 1996

The Sequence Of Event (SOE) system used in nuclear power plants is a part of the Plant Data Acquisition System (PDAS). The SOE system of the existing nuclear power plant share the computer H/W and S/W, and required more complicated structure to provide the events or trip signals. Moreover, there are high potential of collision between synchronization signals and data transmitted to the Plant Computer System(PCS) when the synchronization signals are sent from PCS to the three SOE processors. When this collision happens the SOE system will break down, thus it is not possible to analyze the trend of events or trips. This paper issued the limitation items of the existing SOE system and proposed the revised SOE system.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.11
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• pp.938-942
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• 2000

Radiation effects on dielectric properties of low density polyethylene(LDPE) were investigated using the various measurements of FT-IR, gel content and elongation at break. FT-IR spectra showed that polar groups were comprised in LDPE due to radiation treatment. It was also confirmed that the formation of polar groups on LDPE caused the increased dielectric properties such as permittivity and tan $\delta$. However, in this study, any evidence of decreasing permittivity was not found although the morphological change of LDPE could be identified from the increasing gel content and the decreasing elongation.

• Industrial Engineering and Management Systems
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• v.11 no.1
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• pp.11-17
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• 2012

Along with the recent trend toward increasing variety and shorter life of products in the market, evaluation of risk for economic investment alternatives is of practical importance in manufacturing companies. This paper assumes that each alternative is composed of demand volume and unit sales price as income factors, and unit variable cost and fixed cost as expense factors. The paper assumes that these four factors move worse from the originally expected values, toward the direction of decreasing profit. Values of these four factors are also assumed to fluctuate from year to year over the entire multi-period. By applying the analysis of the breakeven points to each of the four factors, safer area against these changes is represented on the two dimensional domain called normalized total-cost unit-cost domain. A practical numerical example is analyzed to verify the validity of the proposed method.