• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.479-483
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• 2012

This paper describes the development status of rocket engine test facility for the performance evaluation of liquid rocket engine of KSLV-II 1st stage. Design specification and composition of rocket engine test facility are suggested based on the design requirements. The results of the basic design of rocket engine test facility will be used as base data for the detail design and construction of rocket engine ground test facility of KSLV-II 75tonf liquid rocket engine.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.1
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• pp.72.2-72.2
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• 2013

An off-axis telescope has several advantages in optical performance comparing with a conventional on-axis telescope. However, in general, an off-axis telescope has a narrow field of view due to the linear astigmatism caused by the asymmetric structure. It was shown in the previous work that the linear astigmatism can be eliminated by properly configuring parameters in a confocal off-axis reflector system. Furthermore, the third order aberrations of a confocal off-axis telescope can be minimized by optimizing the shape of the mirrors. Despite many advantages, the confocal off-axis telescopes have been evaded because of difficulties of off-axis mirror fabrication, alignment process and unaccustomed off-axis baffle design. The baffle for the off-axis telescope should be designed considering that the effects of stray lights are different because of the asymmetry of off-axis system. In this poster, the design, manufacturing, and test for the baffle and housing of an off-axis telescope are presented.

• The Journal of the Acoustical Society of Korea
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• v.13 no.5
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• pp.59-68
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• 1994

This paper describes the performance assessment test and analysis of test results on a Korean speech recognizer which recognizes Lombard effect received speech in noisy environment, as a basic performance assessment research. In the assessement test, standard speech data were first manipulated close to speech uttered in a noisy environment, and then performance assessment tests were carried out along with the assessment items (the type of noise, SNR) in two ways-one with Lombard effect received speech(LES), the other with not received(NLES). As a result, when 90% of recognition rate is set to be a recognition limit, it was achieved at 10dB SNR point with LES, while at 30dB with NLES. This 20dB of SNR difference indicates Lombard effect should be considered in real world assessment test. The type of noises didn't affect performance of recognizers in out tests. ANOVA analysis, in evaluating several kinds of recognizers, showed every assessment item affecting the recognition performance could be quantified.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.4
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• pp.94-102
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• 2011

Sub-system requirements of a pressure-fed hot-firing test facility for performance assessment of a Liquid Rocket Engine(LRE) thrust chamber using Liquid oxygen and kerosene were described. These requirements were based on the experience of construction and operation of the ground hot-firing test facility which was used for the development of the KSR-III and a 30 tonf-class LRE thrust chamber. So it is expected that this paper is used as a basic material and an itemized previous review statement for the design and construction of a large hot-firing test facility.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.63-71
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• 2010

Sub-system requirements of a pressure-fed hot-firing test facility for performance assessment of a Liquid Rocket Engine(LRE) thrust chamber using Liquid oxygen and kerosene were described. These requirements were based on the experience of construction and operation of the ground hot-firing test facility which was used for the development of the KSR-III and a 30 $ton_f$-class LRE thrust chamber. So it is expected that this paper is used as a basic material and an itemized previous review statement for the design and construction of a large hot-firing test facility.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.12
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• pp.2446-2452
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• 2009

A Ceramic Metal-halide lamp is achieved by adding multiple metals to a basic mercury discharge. Because the vapor pressure of most metals is very much lower than mercury itself, metal-halide salts of the desired metals, having higher vapor pressures, are used to introduce the material into the basic discharge. The metal compounds are usually polyatomic iodides, which vaporize and subsequently dissociate as they diffuse into the bulk plasma. Metals with multiple visible transitions are necessary to achieve high photometric efficiency and good color. Compounds of Sc, Dy, Ho, Tm, Ce, Pr, Yb and Nd are commonly used. The maximum visible efficacy of a Ceramic Metal Halide lamp, under the constant of a white light source, is predicted to be about 450lm/W. This is controlled principally by the chemical fill chosen for a particular lamp. Current these lamps achieve 130lm/W and these life time are the maximum 16,000[hr]. So factors of performance lower are necessary to improve lamp performance. In this paper, we analyzed factors of performance lower by accelerated deterioration test. The lamp was operated with short duration turn-on/turn-off procedure to enhance the effect due to electrode sputtering during lamp ignition. The tested lamp that was operated with a longer turn-on/off(20/20 minutes) showed blackening, changed distance between electrodes and lowered color rendering & color temperature by losses of Dy at 421.18nm, I at 511nm, T1 at 535nm and Na at 588nm compared with the new lamp.

• Fire Science and Engineering
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• v.27 no.6
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• pp.26-31
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• 2013

This study, to evaluate the technology of the fire resistance design of Reinforced Concrete columns based on fire resistance performance design, was suppose to use as basic data for performance design through a measure of temperature and deformation using heat transfer analysis and Heat-load test of the Reinforced Concrete columns as parameter is the axial load ratio. In accordance with axial load without eccentricity, the load ratio of 0.30, 0.35, 0.40 and 0.47 were imposed on columns. As a result of this study, 0.40 or more of axial load ratio can be ensured that the fire resistance performance was considered satisfactory.

• Journal of Korean Clinical Health Science
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• v.6 no.2
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• pp.1189-1198
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• 2018

Purpose. The study was basic materials are provided to identify differences in the knowledge, attitude and performance of cardiopulmonary resuscitation(CPR) depending on the characteristics of child care teachers, and to develop an education program that will enable you to improve your future CPR performance. Methods. This study was conducted on 147 child care teachers. The questionnaire of the previous study was corrected and 48 total questions were used. Using spss 22.0 frequency analysis, T-test, ANOVA and Duncan-test were performed. Results. The knowledge level of 50s was higher those in their 20s. The higher the satisfaction level with education, the more positive was about CPR(p<.001). The more CPR training, the higher the performance(p<.01). The was a positive correlation between CPR attitude and performance ability(r=.355, p<.001). Conclusion. In order to have a positive influence on the CPR of child care teachers, the number of education should be increased and the level of education satisfaction should be managed to increase.

• Journal of Biosystems Engineering
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• v.12 no.3
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• pp.7-16
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• 1987

This study was carried out to develop a microcomputer-based data acquisition and control system which was able to collect the data of engine performance test automatically and control the speed and load of the engine. The results of the study are summarized as follows: 1. The signal processing devices, which were able to measure cylinder pressure, coolant temperature, compositions of exhaust gas, fuel consumption, engine rpm and torque etc., were developed. The results of calibration showed that all of devices had high accuracy ranging from 0.3% to 0.69% respectively. 2. The PIA (peripheral interface adapter) for interfacing digital signal and PTM (programmable timer module) for displaying real time every 0.0408 sec were designed and developed. 3. An engine-speed control system using a stepping motor and driver was developed. The control system had the stability, and faster settling time than the manual control system. 4. The automatic control system of electrical dynamometer, which was able to control the speed and load of dynamometer, was developed with a SSD (shackleton system driver) and D/A converter. 5. The computer programs, which were able to collect and process the data of engine tests, were developed using both the machine language and BASIC.

• Journal of the Society of Disaster Information
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• v.8 no.2
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• pp.197-203
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• 2012

In these days, the design of a structure for reducing or eliminating noise and vibration is getting more important, as the social demands for reducing environmental pollution rise. In this paper, the basic concept and performance verification test results of the recently developed vertical vibration isolator are presented. The isolator attenuates vibration using the damping action from the friction plane made of PTFE and provides the restoring force from the polyurethane springs arranged in vertical and horizontal directions. The performance verification tests consist of a test for identifying performance change during load rate variation and a test for confirming the force-displacement relationship assumption in vibration force range.