• Journal of the Korean Society of Propulsion Engineers
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• v.3 no.4
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• pp.1-11
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• 1999

Thermal behavior of spacecraft propulsion system utilizing monopropellant hydrazine ($N_2$$H_4$) is addressed in this paper. Thermal control performance to prevent propellant freezing in spacecraft-operational orbit was test-verified under simulated on-orbit environment. The on-orbit environment was thermally achieved in space-simulation chamber and by the absorbed-heat flux method that implements an artificial heating through to the spacecraft bus panels enclosing the propulsion system. Test results obtained in terms of temperature history of propulsion components are presented and reduced into duty cycles of the avionics heaters which are dedicated to thermal control of those components. The duty cycles are subsequently converted into the electrical power required in the operational orbit. Additionally, cyclic temperature of each component, which was made under thermal-balanced condition of spacecraft, is compared to the acceptable design range and justified from the viewpoint of system verification.

• The Journal of the Acoustical Society of Korea
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• v.16 no.3
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• pp.64-72
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• 1997

In this paper, study and experiments are performed for finding recognition unit fit which can be used in large vocabulary recognition system. Specifically, a phoneme that is currently used as recognition unit and a syllable in which Korean is well characterized are selected. From comparisons of recognition experiments, the study is performed whether a syllable can be considered as recognition unit of Korean recognition system. For report of an objective result of the comparison experiment, we collected speech data of a male speaker and processed them by hand-segmentation for phoneme boundary and labeling to construct speech database. And for training and recognition based on HMM, we used HTK (HMM Tool Kit) 2.0 of commercial tool from Entropic Co. to experiment in same condition. We applied two HMM model topologies, 3 emitting state of 5 state and 6 emitting state of 8 state, in Continuous HMM on training of each recognition unit. We also used 3 sets of PBW (Phonetically Balanced Words) and 1 set of POW(Phonetically Optimized Words) for training and another 1 set of PBW for recognition, that is "Speaker Dependent Medium Vocabulary Size Recognition." Experiments result reports that recognition rate is 95.65% in phoneme unit, 94.41% in syllable unit and decoding time of recognition in syllable unit is faster by 25% than in phoneme.

• Journal of Korean Society for Geospatial Information Science
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• v.2 no.2 s.4
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• pp.67-79
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• 1994

Recently, the rapid economic growth has caused urban problems due to the increase of urban population and the rapid expansion as a result of exodus phenomenon in rural territories. In order to solve the problems, we need to perform rational and effective plans for national land development. Generally, we need speedy and accurate topographical information of the object area to go ahead with balanced national land development. Acquisition method for topographical data include utilization of existing geographic information such as national base maps and related thematic maps and grasping of accurate present condition of object area using aerial photographies or satellite images. When the object area is small, existing methods for acquiring topographical information reveals imitations in accuracy, speed and economic aspect. Therefore, development of a new method is in order. As a result of this study, we recogized that Photo Balloon System to be manufactured and digital ortho-map to be generated could be used to obtain a topographical information for small areas.

• Journal of Microbiology and Biotechnology
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• v.24 no.10
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• pp.1427-1437
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• 2014

Enzymatic hydrolysis of lignocellulosic biomass into fermentable sugars is a key step in the conversion of agricultural by-products to biofuels and value-added chemicals. Utilization of a robust microorganism for on-site production of biomass-degrading enzymes has gained increasing interest as an economical approach for supplying enzymes to biorefinery processes. In this study, production of multi-polysaccharide-degrading enzymes from Aspergillus aculeatus BCC199 by solid-state fermentation was improved through the statistical design approach. Among the operational parameters, yeast extract and soybean meal as well as the nonionic surfactant Tween 20 and initial pH were found as key parameters for maximizing production of cellulolytic and hemicellulolytic enzymes. Under the optimized condition, the production of FPase, endoglucanase, ${\beta}$-glucosidase, xylanase, and ${\beta}$-xylosidase was achieved at 23, 663, 88, 1,633, and 90 units/g of dry substrate, respectively. The multi-enzyme extract was highly efficient in the saccharification of alkaline-pretreated rice straw, corn cob, and corn stover. In comparison with commercial cellulase preparations, the BCC199 enzyme mixture was able to produce remarkable yields of glucose and xylose, as it contained higher relative activities of ${\beta}$-glucosidase and core hemicellulases (xylanase and ${\beta}$-xylosidase). These results suggested that the crude enzyme extract from A. aculeatus BCC199 possesses balanced cellulolytic and xylanolytic activities required for the efficient saccharification of lignocellulosic biomass feedstocks, and supplementation of external ${\beta}$-glucosidase or xylanase was dispensable. The work thus demonstrates the high potential of A. aculeatus BCC199 as a promising producer of lignocellulose-degrading enzymes for the biomass conversion industry.

• Journal of Korean Society of Transportation
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• v.26 no.5
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• pp.195-204
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• 2008

When the drivers try to read an information on road signs, they can reach their destinations successfully. In this situation, human factors, road signs and geometric condition regarded as the most important factors for a safe driving should be a well-balanced relationship mutually. This research aims to prove the factors obstructing a safe driving, while drivers try to read an information on road signs for the next destination. For this sake, driving simulator was used and human factors, road signs etc. were considered in this experiment. The statistical analysis indicated what factors disturb a safe driving. The probability function using a Logistic Model was presented in this study. This result and experience will be used as a basic data in designing better road signs.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.4 no.2
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• pp.217-228
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• 1997

According to industralization the percentage of working women with children is on the continuous increase. There has been a growing concern over important health problems of middle-aged women, especially with working women. But we didn't know how to care of themselves yet even if it was importment to fint out that. So this reseach was an attempt to identify the nature of experience of their health management so that it is to be contributed to be knowledge development of women' health management strategy. The phenomenological approach in qualitative studies was used to serve this purpose. Subjects were 10 middle-aged working women having children in well-being state. The result of this study was as follows : 'Diet pattern' was to unbalanced and irregular but they tried to correct balanced and harmony dietary life. 'Exercise' was very simple and irregular. They have closed-minded of kinds of exercise. 'Controlling the environment and their minds' was to obtain emotional stability and be free from stress. They put emphasis on refraining from being overtiring and watching their condition carefully. They always tried to keep the peaceful mind. 'Reducing fatigue' was to be bathing, hot streamed-bath, finger pressure therapy, massage, singing, communication with others and maintenance of personal relationships. 'Identification of self-esteem' was very key point to maintain their health. Working regulary gave them to please and value of the life. 'Work oriented life pattern' was to be harm their health state so that it need to be available clinics to check up their health state after work. The rest of this study showed that it need to be social support for working women to work with comfort. Further study regarding working women engaging in the lower level is nesessary.

• Journal of the Korea Society for Simulation
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• v.23 no.4
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• pp.1-8
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• 2014

Cloud computing helps big data processing to make various information using IT resources. The government has to start the RPS(Renewable Portfolio Standard) and induce the production of electricity using renewable energy equipment. And the government manages system to gather big data that is distributed geographically. The companies can purchase the REC(Renewable Energy Certificate) to other electricity generation companies to fill shortage among their duty from the system. Because of the RPS use voluntary competitive market in REC trade and the prices have the large variation, RPS is necessary to predict the equitable REC price using RPS big data. This paper proposed REC price prediction method base on fuzzy logic using the price trend and trading condition infra in REC market, that is modeled in cloud computing environment. Cloud computing helps to analyze correlation and variables that act on REC price within RPS big data and the analysis can be predict REC price by simulation. Fuzzy logic presents balanced REC average trading prices using the trading quantity and price. The model presents REC average trading price using the trading quantity and price and the method helps induce well-converged price in the long run in cloud computing environment.

• Journal of the Korean Society of Clothing and Textiles
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• v.39 no.4
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• pp.517-528
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• 2015

This study investigates actual wearing conditions and satisfaction based on qualitative research for rifle shooting clothing. The survey was conducted in two ways: in-depth interviews of 4 rifle shooting experts and subjective questionnaires for 18 active rifle shooters. They agreed on the importance of rifle shooting wear to minimize body sway and contribute to a balanced body posture. Most rifle shooters purchase made-to-measure rifle shooting clothing at a domestic store, but the clothing often needs extra adjustments due to an uncomfortable fit. Current fabric for rifle shooting clothing consists of a cotton canvas with a polyester mix; however, rifle shooters are unsatisfied with its stiffness in hot and wet conditions. Due to the specific fabric features, rifle shooting clothing should not be washed despite year-round use that represents another point of dissatisfaction. Rifle shooters always wear specially designed underclothes to improve shooting skills and comfort sensation. In conclusion, it is necessary to develop well fitted and comfort rifle shooting clothing that could improve shooters skills based upon this study.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.12
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• pp.22-29
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• 2009

In this paper, we developed the 200-Watts SSPA(Solid State Power Amplifier) for the X-band pulse compression solid state radar. The developed X-band SSPA is consists of 3-stage CSA(Corporate Structured Amplifier) modules in pre-amplifier stage, driver-amplifier stage and main-power amplifier stage. The main-power amplifier stage of SSPA designed by balanced type using GaN HEMT with enough power and gain to generate power more than 200-Watts in X-band. The developed SSPA has performance with more than total gain 59dB and output power 200-Watts in condition of frequency range 9.2-9.6GHz, pulse period 1msec, pulse width 100usec and duty cycle 10%. The developed SSPA in this paper can apply to high quality solid state radar system with pulse compression technique.

• The Journal of the Korea institute of electronic communication sciences
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• v.3 no.4
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• pp.304-312
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• 2008

In this study, the performance analysis was divided into the public sector and private business sector. The four perspectives of the BSC performance analysis for the private business sector can be applied to all of the enterprises as there are Logical Linkages between the four Perspectives. However, these can not be applied in the same way to the public sector. There is no Logical Linkage between public sector and private sectors. Therefore, since there is no Logical Linkage, the KIX project of the public sector has a constrained condition. With the internal and external perspective views, the BSC of the KIX identifies the quality(operation) factor, user(customer) satisfaction factor, and economic costs effects(finance) factor. Based on the linkage model in both the internal and external perspective views and the BSC performance analysis of these views, a performance analysis model was developed and then performance results were analyzed of the whole KIX project.