• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2006.11a
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• pp.161-164
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• 2006

이 논문에서는 AT-DMB (advanced terrestrial digital multimedia broadcasting) 시스템에서 채널정보를 이용하여 Viterbi 복호기의 성능을 향상시키는 방법을 제시하고 그 성능을 살펴보았다. 채널정보는 부반송파를 16-QAM 계층변조한 수신신호로부터 자력적으로 추정한다. 모의실험을 통해 채널정보를 이용한 Viterbi 복호기가 채널정보를 이용하지 않는 복호기에 비해 약 1 dB의 성능향상을 나타냄을 알 수 있었다.

• International Journal of Aeronautical and Space Sciences
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• v.16 no.4
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• pp.529-536
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• 2015

Various R&D programs for rocket-based combined cycle (RBCC) engines have progressed worldwide for the space development and the defense applications. As a way toward indigenous domestic RBCC program, a preliminary design of flight test conditions was studied in this study for a sub-scale RBCC engine using a sounding rocket. Launch and flight profiles were calculated for several booster options and compared with that of HyShot II program. The result shows that the Korea Sounding Rocket-II (KSR-II) is a proper candidate to perform the flight test available in Korea. The recommend flight test conditions with KSR-II are Mach 6.0 with a test vehicle of 230 kg and Mach 7.4 with 50 kg. Present study will soon be followed by a design of sub-scale RBCC for a flight test using a sounding rocket.

• Journal of Food Hygiene and Safety
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• v.27 no.3
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• pp.306-311
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• 2012

Stevioside, a natural sweeteners presently used in various kinds of food and food products in Korea, was evaluated for its toxicity potential in the 14 day feeding study using B6C3F1 mice. Stevioside was added to the diet at different concentrations of 0.31, 0.62, 1.25, 2.5 and 5%, and was administered for 14 consecutive days. An increase of liver organ weight in male mice was observed. No diet-related differences were noted in clinical signs, food consumption, and gross and histopatholgical evaluation. Based on these results, we concluded that the concentration of 5% in the diet was a suitable maximum tolerable dose of stevioside for a 90 day study in mice.

• Food Science and Biotechnology
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• v.14 no.1
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• pp.102-107
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• 2005

In this study, the ameliorating effect of soybean embryos on the impact of alcohol consumption was investigated on rat hepatocytes and in reducing total serum cholesterol levels and total serum lipid levels. Liver histology and two clinically important enzyme markers, aspartate aminotransferase (AST) and alanine aminotransferase (ALT), of rats administered with both alcohol and soybean embryo were compared with a control group. The treatment regimen of soybean embryo significantly reduced the serum ALT and AST levels of the subjects, demonstrating the hepato-protective effects of soybean embryo. Electron microscopy indicated that the administration of soybean embryo preserved the important hepatocyte structures and prevented the presence of lipid droplets and secondary lysosomes. Furthermore, total cholesterol and total lipid levels were significantly reduced. These results indicate that treatment with soybean embryo can positively mediate the effects of alcohol on hepatocytes and general liver functions.

• Fisheries and Aquatic Sciences
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• v.10 no.1
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• pp.24-29
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• 2007

Our objective was to clarify the cytogenetic characteristics, including karyotypes, cellular DNA content, and nuclear size of erythrocytes, of black plaice Pleuronectes obscurus, dotted gizzard shad Konosirus punctatus, and perch sculpin Pseudoblennius percoides, collected from the coastal areas of Jo Island, Busan, Korea. Karyotypes of P. obscurus and K. punctatus both had a diploid number of 48 and a fundamental number (FN) of 48, with a chromosome formula of 48T. The karyotype of p. percoides had a diploid number of 46 and FN of 56, with a chromosome formula of 10SM +36T. No sex-associated heteromorphic pairs were detected for any species. The variation in DNA values (P. obscurus=1.15 pg/nucleus, K. punctatus=1.56pg/nucleus, P. percoides=1.11 pg/nucleus) was positively related to variation in chromosome FN.

• Journal of Hydrogen and New Energy
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• v.18 no.1
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• pp.95-108
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• 2007

There are several methods for the hydrogen production such as steam reforming of natural gas, photocatalytic method, biological method, electrolysis and thermochemical method, etc. These days it has been widely studying for the hydrogen production method having low hydrogen production cost and high efficiency. In this paper, patents in the hydrogen production by water electrolysis were gathered and analyzed. The search range was limited in the open patents of USA(US), European Union(EP), Japan(JP), and Korea(KR) from 1996 to 2005. Patents were gathered by using key-words searching and filtered by filtering criteria. The trends of the patents was analyzed by the years, countries, companies, and technologies.

• Journal of Hydrogen and New Energy
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• v.18 no.2
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• pp.197-206
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• 2007

There are several methods for the hydrogen production such as steam reforming of natural gas, photochemical method, biological method, electrolysis and thermochemical method, etc. Many researches have been widely performed for the hydrogen production method having low production cost and high efficiency. In this paper, the patents concerning the photochemical hydrogen production method were gathered and analyzed. The search range was limited in the open patents of USA(US), European Union(EP), Japan(JP), and Korea(KR) from 1996 to 2005. Patents were gathered by using key-words searching and filtered by filtering criteria. The patent application trend was analyzed by the years, countries, companies, and technologies.

• Journal of the Korean Home Economics Association
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• v.43 no.6 s.208
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• pp.171-182
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• 2005

This study discusses the environmental awareness and the second-hand clothing usage of those consumers who actively purchase used clothing through a clothing swap at a used clothing market. The study used the questionnaire method, weか the subjects being those with experience of buying second-hand clothing. The findings were as follows. 1. The group of higher environmental awareness differed from the group with low environmental awareness in terms of donating or swapping clothing at a green store or in terms of discontinuing the wearing of used clothing bought from a green store. 2. The higher environmental awareness group valued fashion, status symbols and the alignment with others while the group with low environmental awareness valued comfort and economy more than those with the higher environmental awareness. 3. It was discovered that environmental awareness, education and income levels were interrelated.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.1165-1166
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• 2006

This paper presents performance monitoring results of large scale photovoltaic (PV) system supported by general dissemination & regional energy program in korea government polices for new and renewable energy resources. 80kW PV system and monitoring system is constructed and monitored PV system performance to observe the overall effect of environmental conditions on their operation characteristics. The PV system performance has been evaluated and analyzed for component perspective (PV array and power conditioning unit) and global perspective (system efficiency, capacity factor, and electrical power energy and power quality etc.) for six month monitoring periods.

• 한국항공운항학회:학술대회논문집
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• 2015.11a
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• pp.35-38
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• 2015

본 연구에서는 스포츠급 경항공기 모형의 공력 특성을 공군사관학교 아음속 풍동에서 측정하였다. 풍동시험은 유속 40m/s에서 이전 모델과 최근 공력성능 향상을 위해 보완된 모델에 대해 비교 실험 수행하였으며, 정확한 데이터를 얻기 위하여 흐름각 효과, 벽면효과, 지지대 간섭효과를 보정하여 공력계수를 산출하였다. 실험 결과, 두 모델의 항력계수와 양력계수가 전체적으로 유사한 경향성을 보이나 고받음각에서의 양력특성의 차이가 발생하였다. 또한 실제 비행 시의 레이놀즈 수 유동을 모사하기 위하여 Trip strip의 영향에 대하여 실험하였다. 그 결과 Trip strip을 부착하였을 경우 항력계수가 증가하고 최소항력받음각이 낮아지는 결과를 획득하였다.