• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.7
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• pp.575-582
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• 2018

The spaceborne cooler is applied to cool down of the focal plane of the infrared detector of the observation satellite. However, this cooler induces unnecessary micro-jitter which can degrade the image quality of the high-resolution observation satellite. In this study, we proposed a multi-layered blade type vibration isolator to attenuate micro-vibration generated from a spaceborne cooler, while assuring structural safety of the cooler under severe launch loads without an additional launch-lock device. The blade of the isolator is formed with multi-layers in order to obtain durability against fatigue failure and an adhesive is applied between each layers for granting high damping capability under launch vibration environment. In this study, the basic characteristics of the isolator were measured using the free-vibration test. The effectiveness of the isolator design was demonstrated by launch vibration test at qualification level.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.10
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• pp.1471-1478
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• 2010

Microforming processes have recently attracted considerable attention from industry and academia since they enable the production of microscale parts using various materials at a high production rate, minimize material loss, and provide parts with excellent mechanical properties. However, for successful development and applications of the microforming process it is critical to take the tribological size effect into consideration because previous studies have shown that traditional friction models for macroscale forming generate significantly erroneous results in the case of microforming. In this paper, we performed scaled ring compression experiments to investigate the tribological size effect of aluminum and brass materials in microforming. The sensitivity of the interfacial friction to the deformation characteristics of the ring was quantitatively analyzed by the finite element analysis. In addition, a friction model based on slip line field and upper boundary techniques was used to theoretically explain the friction mechanism in microforming.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2002.10a
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• pp.73-76
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• 2002

The temperature and humidity of dirt-walled storehouse are observed in order to verify the traditional storehouse (main material : soil) during 7days (4th. $Sep{\sim}10th$. Sep). Because the width of the daily variation of temperature is small as $2.5^{\circ}C{\sim}5^{\circ}C$, the reduction of energy supply for low temperature is expected. Because the relative humidity is high and it's variation is small ($4%{\sim}9%$), the inner humidity of dirt-walled storehouse is easily maintained above 80% is expected.

• Korean Journal of Environmental Biology
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• v.21 no.1
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• pp.31-35
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• 2003

The effects of different extraction methods on quality of citron juices were investigated in terms of chemical composition and sensory evaluation. Extraction methods employed were press-filtration with 400 mesh sieve, centrifugation, and enzyme pretreatment using pectinase. Enzyme pretreatment method showed the highest yield of juice with 68%, while press-filtration method, the lowest yield of juice with 26.3%. The pH of the juices was relatively similar at 3.29～3.34. Filter-pressed juice showed the highest concentration of soluble solid at 6.0$^{\circ}$Brix, while the juice produced using centrifugation showed the lowest concentration at 4.5$^{\circ}$Brix. In all the juices, fructose was the main soluble sugar. Concentration of organic acid was the highest with the juice produced with centrifugation so that supplementation with higher amount with sugar was needed for overall acceptability.

• Proceedings of the Korea Technology Innovation Society Conference
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• 1998.05a
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• pp.24-24
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• 1998

국내 소프트웨어산업은 산업특성상 우리 나라에 적합한 산업이며 국내시장 규모도 급증하고 있으나 선진국에 비해 낙후되어 있는 형편이다. 따라서 최근 각광 받고 있는 소프트웨어 창업기업들을 대상으로 실사 및 설문지 조사를 통해 소프트웨어산업에 있어서의 성공요인들을 알아보고 이를 바탕으로 국내 소프트웨어산업의 국제경쟁력 제고를 위한 방안을 모색하는 것이 무엇보다도 필요한 시점이다. 이러한 본 연구의 목적을 달성하기 위해 조사대상 기업체를 기존 연구들처럼 소프트웨어산업에 종사하고 있는 기업들을 임의적으로 추출하여 자료를 수집하는 대신 성장 가능성이 있다고 판단되어 선정된 유‘망 중소정보통신 소프트웨어 기업’들과 현재까지 선정되지 못한 기업의 두 그룹으로 나누어 자료를 수집하였다. 수집된 자료를 바탕으로 두 그룹간의 창업배경 및 성장과정별로 비교분석을 통해 차이점을 밝히고자 하였으며 창업이후 성공적 운영에 필수적인 우위요인에 관해서도 살펴보았다. 이러한 비교분석결과에 근거하여 국내 소프트웨어산업의 성공요인 및 국제경쟁력 제고를 위한 방향을 제시하고자 하였다. 선정기업과 비선정기업간의 비교를 통한 성공요인 분석결과를 요약하여 살펴보면 다음과 같다. 첫째, 창업자의 일반적 특성과 창업배경 및 창업동기를 볼 때, 창업배경 또한 연구개발직 경험을 바탕으로 창업한 경우가 가장 많았으며, 주된 창업동기는 기술력에 바탕을 둔 사업화/동업화였다. 둘째, 창업자의 경영의지를 보면 창업 이전 준비 및 계획에 철저했으며, 각종 지원제도를 적극적으로 활용했을 뿐만 아니라 비혜택 제도도 적극적 활용(예; 공고생 현장실습제도 활용정도, 기술지도 및 연수사업 활용정도 등)하였으며, 특히 창업자가 미래에 대한 확신과 긍정적 사고, 및 성공에 대한 의지가 높았다. 셋째, 기술력을 보면 자체연구소 보유비율이 월등히 높으면, 보유기술도 국내에서 가장 먼저 개발하는 단계였거나 독자적인 기술보유가 많았고, 기술력 유지를 위한 신기술 연구개발투자의 강화, 신제품개발 및 품질향상을 지속화, 및 이를 뒷받침하기 위한 전문기술인력의 확보에 주력하였다. 끝으로 마케팅 능력면에서도 개발된 신제품에 대해 자체상표를 부착하는 비율(84.6% 대 64.5%)이 높고 다양한 판매경로를 통해 제품을 판매하였으며, 기업 및 제품이미지 제고를 위한 고객에 대한 서비스도 강화하고 있었다.

• Korean Journal of Food Science and Technology
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• v.20 no.5
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• pp.683-690
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• 1988

This study was conducted to determine the organoleptic and physical properties and carotenoid of commercial canned, frozen and freshly-made carrot juice. Samples were evaluated by sensory panel and measured for viscosity and acidity. For carotene analysis, HPLC of alpha- and beta-carotene, and spectrophotometry of total carotenoid content were used. Sensory evaluation indicated that the canned sample was less acceptable, especially for flavor and texture, than other juices, while forzen juice was considered as acceptable as freshly-made carrot juice. The canned product showed about 10 times higher viscosity and lower acidity than others. Between two kinds of frozen samples, one sample was the same as freshly-made sample for all parameters while the other showed less alpha-carotene content which was 2 times higher than that of canned one. Canned sample contained 70-77% of freshly-made or frozen samples in total carotenoid and beta-carotene content and 24% of freshly-made one in alpha-carotene. These results suggest that freezing process is a good preservation method for carrot juice with respect to sensory evaluation, physical property and carotenoid content.

• Journal of Biosystems Engineering
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• v.2 no.2
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• pp.1-14
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• 1977

현재 선진국에서 널리 이용되고있는 곡물의 화력건조는 곡물의 품질을 손상시킬 뿐만 아니라 손실을 증가시키고 있다. 화력에 의한 건조는 또한 연료의 절약면에서 볼 때 역시 문제점을 내포하고있다.l 이러한 문제점들을 해결하기 위하여 근래에는 실리카 젤과 같은 흡습성의 건조제를 사용한 곡물의 건조 실험이 진행 중에 있으며 좋은 결과를 보여주고 있다. 실리카겔은 그 자체무게의 40% 까지 동적 및 정적하에서 수분을 흡수하는 성질을 가지고 있으며 일단 포화상태가 되면 수천번 재생이 가능하다. 본 연구에서는 이와같은 실리카텍의 재생실험을 일차적으로 실내에서 공기의 온도를 일정하게 한 상태에서 실시하였으며 일반적으로 실리카 젤은 $300^{\circ}F$에서 완전재생이 가능하나 본 실험에서 사용된 재생온도는 평면식 태양열 집열기로부터 얻을 수 있는 $150^{\circ}F$ 내외에서 시도하였다. 본실험과 병행하여 건조중 공기와 실리카 젤의 에너지 및 질량변화에 따른 이론식을 만들어 주어진 여러 가지 조건에 대하여 4개의 미분방정식을 컴퓨터에 의하여 해결하였으며 건조(재생) 시간에 따른 공기의 온도와 흡습 및 실리카 젤의 함수량을 구하였다. 위의 이론적인 분석결과는 후에 태양열집열기를 이용한 재생실험을 분석하는데 적용될 것이다. 본 연구결과를 요약하면 다음과 같다. 1. 본 연구에서 유도한 이론식은 실리카 젤의 재생온도를 만족스럽게 표시하였으며 재생시간에 따른 공기의 온도와 흡습 및 실리카 젤의 함수량변화의 이론치는 실험치와 근사하였다. 2. 이론치와 실험치를 일치시키기위하여 흡착온도에서 산출된 열 및 질량 전달계수를 1/5로 조정 사용하였다. 3. 실리카 젤은 $120^{\circ}F$에서 9 %, $180^{\circ}F$에서 1% 내외로 재생이 가능하였다. 4. 본 연구에서 유도된 이론적 분석방법은 다른 여러 가지 형태의 물질 및 건조 또는 냉각 과정을 분석하는데 사용될 수 있다.

• Journal of Bio-Environment Control
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• v.6 no.4
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• pp.292-298
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• 1997

These studies were conducted to verify the effect of the supplementary lighting by reflective film mulching and its establishment in the north side of greenhouse on the utility of light at tomato by means of investigating changes of leaf temperatures, stomatal features, transpiration rates and photosynthetic rates. Stomatal density of leaves were high in the reflective film mulching but sizes of stomata were not different. As the osmotic potential in rooting zone was low, the stomatal resistance was high, transpiration rate was low, and leaf temperature was increased by 40.62$^{\circ}C$. And also in the block of reflective film mulching photosynthetic rates were decreased hut chlorophyll contents were not different. Especially, there is an effect of controlling greenhouse whiteflies by treatment of reflective film mulching. It is thought that the reason of high quality or increasing yield at several crops by supplementary lighting, such as reflective film mulching, would be caused by influences of absorption and distribution of nutrients through high transpiration rate and photosynthesis which resulted from increase of stomata.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.12
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• pp.899-912
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• 2009

With greater utilization of web application and growth of its market, the function of such application is being expanded With today's increasing demand for high quality software, we see a sharp rise in the interest for web application test. The current trend is that web applications are being developed based on a framework of developmental environment. Hence, as the scope of that framework expands, each module of the entire web application is being configured by the combination of heterogeneous files. The distinctive characteristics of a web application are based on the fact that the framework that is provided in partially completed form controls the structure of all objects of development. The present study defines the web business logic as a minimal unit which has meaning as a unit of application for the web application. In this paper, we define web business logic as a least meaningful execution unit of web applications, propose how to generate automatically the BizUnit test code for it, and analyze the effectiveness of testing of the web application via the BizUnit test codes.

• The Journal of the Korea Contents Association
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• v.14 no.12
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• pp.706-722
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• 2014

This paper investigates audience perception on news content through comparison analysis on Comprehensive Programming Channels, TV chosun, JTBC, Channel A, and Terrestrial Broadcasting 'KBS'. How sensationalism created by video news affect audiences' credibility on news and media. The results shows that Comprehensive programming channels are assessed more sensational than terrestrial broadcasters by audience. Additionally, Comprehensive programming channels are assessed to get a lower credibility than terrestrial broadcasters by audience in the analysis of news and media credibility, comprehensive programming channels and terrestrial broadcasters. As a result, comprehensive programming channels showed lower news credibility and media credibility compared to that of the terrestrial broadcasters. This means that comprehensive programming channels must do the best not only recovering credibility from audiences but also constructing position as national broadcasting media.