• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.79-82
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• 1997

In this paper, a body-worn type digital hearing aid (DHA) based on a dedicated DSP chip is developed. A fitting software running on a PC supported by the Win95 OS is also developed. The fitting protocol is based on the NAL-R procedure applied to eight frequency bands, but it is designed to support a curvilinear fitting to cope with the nonlinear perception of hearing-impaired listeners. Preliminary subjective tests regarding the speech intelligibility and perceived quality revealed that the new DHA could be of benefit to hearing aid users.

• The Journal of Internal Korean Medicine
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• v.20 no.1
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• pp.153-166
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• 1999

SAENGMAEGSAN(SMS) has been used in oriental medicine for many years as a therapeutic agent for cerebral disease. The effect of SMS on the vascular system is not known. The purpose of this study was to determine the effect of SMS on blood pressure, regio-nal cerebral blood flow(rCBF). 1. Blood pressure did not change by SMS in rats. 2. rCBF was increased by SMS in a dose-dependent manner. 3. Pretreatment with propranolol. methylene blue and indomethacin significantly inhibited SMS induced increase in rCBF. These results suggest that SMS causes a diverse response of blood pressure, regional cerebral blood flow (rCBF) and pial arterial diameter. The increase in rCBF is also mediated by prostaglandins. cyclic GMP and adrenergic ${\beta}$receptor.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.492-494
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• 2002

The fundamental principles of the operation of microwave discharges that are used to convert microwave energy to broad spectrum visual light are known. In this paper, emission dependance of microwave discharges in mixture content of sulfur with noble gases was studied. It is shown that the excitation of this gaseous mixture is carried out in two phases: (1) ionization of noble gas atoms by a microwave field and (2) the consequent maintenance of slightly ionized nonequilibrium plasma by the field. These two processes have essentially various thresholds for the microwave pump. The purpose of this work is to investigate spectral properties of the high frequency discharges in a mixture sulfur vapors with noble gases.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1394-1396
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• 1994

Polyimide thin films were fabricated an using vapor deposition polymerization apportus, and their FT-IR and TGA characteristics were investigated. The peaks of $720cm^{-1}$ and $1380cm^{-1}$ show C=O stretch mode and C-N stretch mode, and that of the cured polyimide at $350^{\circ}C$ were sturated. $T_d$(Depolymerization temperature) was showed at $405^{\circ}C$ from research of thermal resistivity characteristics by TGA It was possible to fabrication of polyimide thin film by VDPM.

• Journal of the Korean housing association
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• v.11 no.1
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• pp.103-113
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• 2000

The main purpose of this paper is to provide useful infonnation for residential site design in Korea by analyzing Japanese case. The important characteristics of Japanese design techniques are follows. First, the characteristics of residential site development can be expressed as "eco-friendly" and "public order". The patterns of spatial use also focuses on living environment improvement. Second, variety replaces unity in internal mobility plans. For example the width of street, size of park are not same in a site boundary. Third, to avoid street parking and commodity exhibition, commercial buildings are set-back and public parking lot is constructed. Fourth, fences of private house are made of trees rather than bricks. It connects green environment between internal and external space of houses.nal space of houses.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.763-767
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• 2004

A possible and practical engine system research method is proposed. Varieties of objectives of the engine component and system technology developments are fulfilled by the small scale rig and engine demonstration. Some research applications of small jet engines in National Aerospace Laboratory of Japan (NAL) are presented together with historical overview.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3126-3128
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• 1999

In 22.9kV-Y overhead lines, if there is an earth fault, high fault current causes surge type over-voltages around this place. There are generally two types of earth faults. One is an earth fault which occurs when a voltage line falls to earth line. The other occurs when a voltage line directly falls to the earth. This study presents an analysis method on the earth fault.

• Journal of the Korean Society for information Management
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• v.15 no.2
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• pp.7-28
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• 1998

The purpose of this study is to overview and analyze the commercial document delivery systems. to this end, the study first compared the current systems under three headings, that is, non-collection-based systems(Infotrieve, OCLC, UnCover, BIDS, Swets & Zeitlinger, Kyobobook), collection-based systems(EBSCO, ISI, UMI, BLDSC, CISTI, INIST, NCSI, JICST, KINITI), and specialized collection-based systems(Engineering Information Inc., IEEE/IEE, BIOSIS, CAS, NAL, RSC, TWI, ADONIS). Next, the study analyzeed the advantages and disadvantages of each system, based on the four performance criteria : scope of inventory/journal coverage, turnaround time, delivery ost and payment options, reliability and satisfaction rate.

• Bulletin of the Korean Chemical Society
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• v.20 no.5
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• pp.587-591
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• 1999

A molecular dynamics simulation study on the structure and dynamics of Na+ ions in non-rigid dehydrated Na12-A zeolite framework at 298.15 K was conducted using the same method reported in previous studies on rigid and non-rigid Na12-A zeolite frameworks. The agreement between the experimental and calculated results for the zeolite-A framework atoms of structural parameters for non-rigid dehydrated Na12-A zeolite is generally quite good, and for the adsorbed Na+ions the agreement is acceptable. The calculated bond lengths are generally in good agreement with the experimental results and other theoretical data. The calculated IR spectrum by Fourier transform of the total dipole moment autocorrelation function shows two major peaks around 2700 cm-1 and 7000 cm-1. The former appeared in the calculated IR spectra of non-rigid zeolite-A framework only system and the latter remains unexplained except, perhaps, indicating a new formation of a vibrational mode of the framework due to the adsorption of Na+ ions. The peaks above 6200-6800 cm-1 in non-rigid dehydrated Nal2-A zeolite are much larger than those in non-rigid dehydrated H12-A zeolite.

• Structural Engineering and Mechanics
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• v.35 no.3
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• pp.349-364
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• 2010

The impact behaviour and the impact-induced damage in laminated composite cylindrical shell subjected to transverse impact by a foreign object are studied using three-dimensional non-linear transient dynamic finite element formulation. A layered version of 20 noded hexahedral element incorporating geometrical non-linearity is developed based on total Langragian approach. Non-linear system of equations resulting from non-linear strain displacement relation and non-linear contact loading are solved using Newton-Raphson incremental-iterative method. Some example problems of graphite/epoxy cylindrical shell panels are considered with variation of impactor and laminate parameters and influence of geometrical non-linear effect on the impact response and the resulting damage is investigated.