• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.35-38
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• 2005

In this study, S-Band receiver for low orbit satellite is implemented. The developed receiver is double super-heterodyne type and STDN compatible. Input/output frequency of receiver is 2034.747MHz and 18.414MHz used for KOMPSAT 2 satellite. Overall gain(@AGC=0V) and image rejection were 92.4dB and 50.2dB respectively. It was verified that receiver has stable performance to the temperature limit, power supply voltage variation and input signal level range.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.685-688
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• 2008

Mini-LVDS has been widely used for high speed data transmission because it provides low EMI and high bandwidth for display driver. In this paper, a Mini-LVDS output buffer with LTPS TFT process is presented which provides sufficient performance in the presence of large variation in the threshold voltage and mobility and kink effect.

• Proceedings of the Optical Society of Korea Conference
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• 2004.02a
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• pp.288-289
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• 2004

The performance of the InGaAs/InP avalanche photodidodes operated in Geiger-mode was investigated for 1550nm wavelengths at room temperature. We find the optimal operating points where the high quantum detection efficiency and low dark current are achieved. For the optical pulse detection, the gated-mode is used to reduce the dark current.

• Journal of Biosystems Engineering
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• v.39 no.3
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• pp.194-204
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• 2014

Purpose: The aim of this study was to develop long-term storage technology for Chinese cabbage in order to extend the period of availability of freshly harvested products. The scope of the paper deals with the use of a cooler with a remote monitoring and control interface in conjunction with use of packaging film. Methods: A cooler with a real time monitoring system was designed as a low-temperature storage facility to control temperature and relative humidity (RH). The effects of storage in high-density polyethylene (HDPE) plastic boxes, 3% chitosan dipping solution, polypropylene film (PEF) with perforations, and mesh packaging bags on physiological responses were investigated. The optimal storage temperature and humidity for 120 days were below $0.5^{\circ}C$ and 90%, respectively. Physiological and biochemical features of cabbage quality were also analyzed: weight loss, texture, and sugar salinity, chlorophyll, reducing sugar, and vitamin C contents. Results: The cooler with a remote monitoring and control interface could be operated by an HMI program. A $0.5^{\circ}C$ temperature and 90% humidity could be remotely controlled within the cooler for 120 days. Postharvest freshness of Chinese cabbages could be maintained up to 120 days depending on the packaging method and operation of the remote monitoring system. In particular, wrapping the cabbages in PEF with perforations resulted in a less than a 5% deterioration in quality. This study provides evidence for efficient performance of plastic films in minimizing post-harvest deterioration and maintaining overall quality of cabbages stored under precise low-temperature conditions with remote monitoring and a control interface. Conclusions: Packaging with a modified plastic film and storage in a precisely controlled cooler with a remote monitoring and control interface could slow down the physiological factors that cause adverse quality changes and thereby increase the shelf life of Chinese cabbage.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.5
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• pp.363-363
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• 2001

• Proceedings of the SAREK Conference
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• 2003.07a
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• pp.153-153
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• 2003

• Proceedings of the SAREK Conference
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• 2005.06a
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• pp.34-34
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• 2005

• Culinary science and hospitality research
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• v.19 no.4
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• pp.211-230
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• 2013

The purpose of this study was to investigate importance and performance about the quality attributes of bean coffee and instant coffee for the Koreans and the Mongolians. The survey was conducted in Seoul and Gyeonggi Province, Korea and in Ulaanbaatar, Mongolia from April to May, 2012. The questionnaire was distributed to 380 Koreans and 380 Mongolians, and 253 and 250 copies were collected from the Koreans and the Mongolians, respectively, for statistical analyses. For the importance-performance analysis(IPA), 14 quality attributes of bean coffee and instant coffee were investigated. The main results of this study were as follows. In the importance and performance comparison about the bean coffee quality, taste, aroma, quantity, price, hygiene, freshness and shelf life were more important to the Koreans than to the Mongolians. On the other hand, nutrition and ingredient were regarded as more important attributes for the Mongolians. Also, price, nutrition, temperature and ingredient were better performance to the Mongolians than to the Koreans. In the importance and performance comparison about the instant coffee quality, quantity and price were more important to the Koreans than to the Mongolians. However, nutrition and temperature were more important to the Mongolians. Moreover, nutrition, temperature, variety and freshness were better performance to the Mongolians than to the Koreans. According to the IPA results of 14 quality attributes of bean coffee, the selection attributes with high importance but low performance were price and shelf life for the Koreans, while nutrition, hygiene and ingredient for the Mongolians. For instant coffee, the selection attributes with high importance but low performance were hygiene and concentration for the Koreans, while concentration and ingredient for the Mongolians.

• Journal of the Korean Solar Energy Society
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• v.30 no.6
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• pp.28-33
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• 2010

Solar collectors to be applied are mainly flat-plate or vacuum tube collector which is used for hot water supply of house because of low heat value and low temperature. There are a necessity to expand applicable scope of solar collector into the industrial process heat source and air conditioner for coping with renewable energy policy of government and industrial trend. This study is to analysis the performance of PTC solar collector of concentrating type and flat-plate of non-concentrating. For this, temperature difference and heating value as insolation of air outside is measured from these two collectors mounted on 2-axial solar tracking system. It is investigated that temperature profile obtained from PTC solar collector is uniform and collecting heat per unit area is 6.8kcal/$m^2$ min which is about 3 times with compare to flat-plate collector of 2kcal/$m^2$min. Also the amount of heat to be produced from PTC solar collector is 3 Mcal/$m^2$ which is about 2 times with compare to flat-plate collector of 1.5Mcal/$m^2$ as a result of operating these two collectors during one month. Therefore, it is obtained that heat collecting performance of PTC solar collector is superior to flat-plate.

• Korean Journal of Community Nutrition
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• v.5 no.1
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• pp.100-108
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• 2000

Seven constructs of sanitary management :time temperature, storage, cross-contamination, personal hygiene, equipment facility and documentation management were evaluated to investigate the perceived performance of sanitary management for school food service managers, Using a four-part questionnaire containing the seven constructs of sanitary management HACCP program, demographic information and characteristics of food service facilities participants rated their self-perceptions regarding sanitary management. Of the 550 possible respondents, 248(45.1%) completed the study. For the perceived sanitary manage-ment variables, the participants rated them between 2.66 and 4.16(5-point Likert scale). Temperature management presented the lowest performances while storage management showed the highest. The number of years of work experience of the food service managers and the serving location correlated significantly to sanitary management variables. Documentation management was also highly correlated to the other sanitary management constructs. The respondents ranked the managers leadership and professional knowledge regrading HACCP as most important, followed by the facilitys supporting equipment and human resources second, to successfully implement the HACCP system at the school food service facilites, Awareness of this study indicating low performance on temperature management suggests an active training program is needed for sanitary management of school food service.