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        검색결과 99

        21.
        2017.04 구독 인증기관·개인회원 무료
        The effects of high hydrostatic pressure (HHP) or concentration treatment or sodium hydrogen carbonate addition on microbial and quality properties of cold drip liquid coffee were investigated during storage at room temperature. Cold drip liquid coffee was determined to pH, acidity, general bacteria, and Y&M (Yeast and Molds) according to HHP treatment or adding 0.2% sodium hydrogen carbonate for 40 days storage at 20°C. Also, an equivalent mixture of concentrated coffee and cold drip liquid coffee or liquid coffee with 0.2% sodium hydrogen carbonate was used for determining the sensory evaluation, due-trio and preference test. The cold drip liquid coffee with 0.2% sodium hydrogen carbonate had higher pH and lower titratable acidity than the control during 40 days storage at 20°C. Total viable cell and Y&M counts of cold drip liquid coffee added with 0.2% sodium hydrogen carbonate or treated by HHP at 300 MPa for 25 min were lower than the control during storage at 20°C. The result of the due-trio and preference tests shows that there was no significant difference between cold drip liquid coffee added to 0.2% sodium hydrogen carbonate and the control or between the equivalent mixture of concentrated coffee with cold drip liquid coffee and the control. As a results, Cold drip liquid coffee treated by HHP, concentrated by evaporation, and added to sodium hydrogen carbonate has a potential to extend a shelf life at ambient temperature storage.
        22.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이 연구에서는 RTK-GPS 장비를 사용하여 상시바람하중 및 가진 진동 실험시 계측된 변위 응답을 이용하여 실물크기 5층 철골 프레임에 대한 시스템식별 실험을 수행하였으며, 그 결과를 가속도 응답을 사용하여 얻은 결과와 비교하였다. RTK-GPS는 10Hz의 비교적 낮은 샘플링 속도를 가지고 있어 현장상황을 고려하여 적절한 측정안정도를 확보하는 것이 중요하였다. 변위자료를 사용하여 식별된 모드특성은 가속도 자료를 사용하여 얻은 것과 동일하였으며, 가속도계를 사용하여 측정할 수 없는 변위응답의 평균성분을 관측할 수 있었다.
        4,000원
        23.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Changes in land use and increase in urban energy consumption influence urban life. This study analyzed the characteristics and patterns of urban heat and presents management schemes to generate a comfortable and sustainable urban environment. The study aimed to demonstrate the positive effects of artificial ground greening on improving the microclimate through evapotranspiration using perennial herbs. We have designed a chamber that could control constant temperature and humidity, measure temperature reductions in each plant and changes in sensible heat and latent heat. This study identified Sedum kamtschaticum as the most effective plant in controlling temperature. At 22℃, 3.2℃ temperature reduction was observed, whereas four other plants showed a 1.5℃ reduction. At 25℃, 2.0℃ temperature reduction was observed. On the other hand, the use of Sedum sarmentosum resulted in the lowest effect. Zoysia japonica is the most commonly used ground covering plant, although the temperature reduction of Lysimachia nummularia was more effective at high temperature conditions. Sensible heat and latent heat were calculated to evaluate the thermal performance of energy. At a temperature >30℃, L. nummularia and S. sarmentosum emitted high latent heat. In this study, we analyzed the thermal performance of green roof perennial plants; in particular, we analyzed the evapotranspiration and temperature reduction of each plant. Since the substrate depth and types, plant species, and seasonal change may influence temperature reduction and latent heat of green roofs, further studies are necessary.
        4,000원
        24.
        2016.02 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to evaluate the performance of a tube and badge type NO2 passive air sampler. The principle of the method is a colorimetric reaction of NO2 with N-1-naphthylethylendiamine under acidic conditions. The sampling rates for the tube and badge type passive air samplers was determined 12.3 ± 4.4 mL/min and 27.3 ± 4.9 mL/min, respectively, as obtained from the slope of the linear correlation between the NO2 mass collected by the passive air sampler and the NO2 concentration with the NO2 analyzer. The tube and badge type passive air sampler were moderately correlated with a correlation coefficient of 0.9112. The measurement for the precision and accuracy of the passive air sampling was carried out with duplicate measurement of passive air samplers. The passive air sampler had good precision and accuracy for measuring NO2 in atmosphere. A good correlation was observed between the passive air sampler and the NO2 analyzer with a coefficient of determination of 0.9153 (tube type) and 0.9514 (badge type). This passive air sampler would be suitable for the NO2 concentration monitoring in atmosphere.
        4,000원
        25.
        2015.09 구독 인증기관 무료, 개인회원 유료
        디스플레이 주변의 조도 환경 변화에 따라 인지되는 영상의 시인성이 달라지게 된다. 특히, 높은 조도 환경 에서는 영상의 인지 contrast가 저하되고, 어두운 영역의 detail이 손실되는 문제가 발생한다. 본 논문에서는 높은 조 도에서 인지되는 영상의 시인성을 향상시키기 위해 어두운 영역의 detail 보상을 고려한 contrast 개선 알고리즘을 제 안한다. 영상의 contrast 개선을 위해 TMF(Tone Mapping Function)를 사용하며, TMF는 영상 특성 및 주변 조도에 따라 적응적으로 도출된다. 제안하는 contrast 개선 방법의 성능을 평가하기 위해 원본, 제안하는 방법과 기존 방법의 결과들을 대상으로 성능 비교를 위한 시각 실험을 수행한다. 실험 결과 제안하는 방법을 적용한 영상의 시인성이 원 본 및 기존 방법에 비해 향상된 것을 확인하였다.
        4,300원
        26.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The cases of conducting the vibration measurement using the mobile phone with regard to the building's horizontal vibration are very rare in Korea and foreign countries. Therefore, this study analyzed the horizontal vibration nature of the building using the mobile phone targeting 5 tall buildings, and reviewed about the applicability of the mobile phone vibration measuring instrument through the comparison/verification with the data of the existing vibration measuring instrument. The peak of the measured time series waveform was measured clearly and it showed a similar value to the existing natural frequency.
        4,000원
        27.
        2015.07 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        For rear metallization with Al paste, Al back contacts require good passivation, high reflectance, and a processing temperature window compatible with the front metal. In this paper, the effect of the firing ambient during the metallization process on the formation of Al rear metal was investigated. We chose three different gases as ambient gases during the firing process. Using SEM, we observed the formation of a back surface field in N2, O2, and Air ambients. To determine the effect of the ambient on Voc, the suns-Voc tool was used. In this study, we described the mechanism of burn-out of organic materials in Al paste during the firing process. The oxygen ambient plays an important role in the burn-out process. We calculated the efficiency with obtained the back surface recombination velocities using PC1D simulation. It was found that the presence of oxygen during the firing process influenced the uniform back surface field because the organic materials in the Al paste were efficiently burned out during heating. The optimized temperature with oxygen flow shows an absolute efficiency of 19.1% at PC1D simulation.
        4,000원
        28.
        2015.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        There is no doubt that global warming and climate change affect animal production and sustainability of livestock systems. High ambient temperature and humidity have detrimental effects on the performance of laying hens. The aim of this study was to evaluate the influence of cyclic temperatures on the performance and egg quality of laying hens during the summer in Korea. A total of 1028 Hy-Line Brown layers were reared in the open floor house and exposed to a 24 hr linear temperature cycle ranging from 21.7 to 33.0℃. Feed intake significantly decreased and cracked eggs increased under high ambient temperature or high THI (Temperature Humidity Index). Egg production was decreased gradually from 21 to 29℃ or from 21 to 26 THI. On the other hens, it was increased above 30℃ or 27 THI rather than decreased. High ambient temperature has no important impact on dirty eggs and mortality in this study. We believe that present data contribute to predict the effect of thermal conditions on the performance of laying hens by using ambient temperature or THI
        4,000원
        29.
        2015.04 구독 인증기관·개인회원 무료
        The clamping of torque shear high strength bolt is induced when the pin-tail is broken. Sometimes the clamping forces on slip critical connections do not meet the required tension due to torque coefficient dependent on conditions such as outdoor temperature, moisture and dust. From this study, the clamping forces of torque shear bolts at indoor conditions were compared with actual data investigated from 24 construction sites last five years. Similarly to foreign literature results, torque shear bolts showed that torque coefficients were fluctuated greatly by temperature conditions. The range of torque coefficient at indoor conditions was analyzed from 0.126 to 0.158 while tensions were indicated from 179 to 192 Nㆍm. Instead, the range of torque coefficient at site conditions was analyzed from 0.118 to 0.152. Based on this test, the variable trends of torque coefficient subjected temperature can be traced via statistic regressive analysis. In case of indoor conditions, it was showed that the variable of torque coefficient was 0.13% per 1℃, while the variable at actual site conditions reached 2.73% per 1℃.
        30.
        2015.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 고온 환경에서 Yorkshire 품종의 혈액 내 전해질과 혈액학적 성분의 변화를 조사하기 위하여 실시하였다. 73 일령(BW 40.6±1.4 kg)의 Yorkshire종 10두를 공시하여 개별 pen에 1두씩 배치하였다. 시험기간은 한국에서 폭염이 시작되는 2013년 7월 24일부터 동년 9월 4일까지 6주간 실시하였다. 시험기간 중 평균온도가 가장 높은 시기는 시험 3주차(28.6℃)였으며, 최고온도는 시험 4주(32.1℃)에 관찰되었다. 일당증체량은 온도가 가장 높았던 시험 3주차부터 감소하는 경향으로 나타났다. 혈청 내 pH와 삼투압은 시험기간 동안 유의적인 변화가 관찰되지 않았다. 나트륨이온 (P<0.01)과 염소이온(P<0.05)의 농도는 시험 6주에 유의적으로 증가하였다. 일반혈액검사 분석 결과에서 혈액 내 호중구(P<0.05)와 단핵구(P=0.057)의 수준은 시험 6주에 증가하고, 헤모글로빈과 평균 적혈구 혈색소 농도는 시험 4주와 6주에 감소하는 것으로 관찰되었다(P<0.05). 혈액생화학 분석에서는 총 콜레스테롤(P<0.01), 총 단백질(P<0.001)과 혈중 요소태 질소(P<0.01)의 농도가 4주와 6주에 높아지는 것으로 관찰되었으며, glucose 농도는 6주에 유의적으로 낮아졌다(P<0.05). 본 연구의 결과는 한국의 여름철 폭염기간 동안 돼지의 체내에서 생리생화학적, 혈액학적 변화가 어떻게 변하는지에 대한 기초정보를 제시하며, 이러한 정보는 혹서기 고온 스트레스로 인한 돼지 생산성저하 방지 기술을 개발하는 데에 기초자료로 활용될 수 있을 것으로 사료된다.
        4,200원
        31.
        2012.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        구조물의 특성치를 결정하기 위하여 18층 규모의 사무용 건물 3동에 대하여 자연진동 조건하에서 동적계측실험을 수행하였다. 대상건물은 기본적으로 보-기둥 골조시스템에 횡하중을 보다 효율적으로 지지하기 위하여 추가적으로 코아가 배치된 혼합 구조형식을 나타낸다. 매층 마다 측정한 일련의 진동기록으로부터 고유진동수, 모드형태 및 감쇠율 등과 같은 모달계수를 추출하기 위하여 최신주파수- 및 시간영역-기반 응답의존 시스템판별법인 FDD, pLSCF 및 SSI를 적용하였다. 3방법에 의하여 추출한 결과는 대체로 일치하였으나, 초기 FE 해석결과와 비교하여 저차 3개 고유진동수는 대략 1.2~1.7배나 되는 단단한 거동을 나타냈다. 진동응답으로부터 추출된값, 기준에서 제시하는 약산식 및 FE해석에 의하여 산정된 고유주기를 비교하여 보면, FE결과가 가장 유연한 거동을 예측하였으며, 높이를 변수로 하는 약산식이 추출된 값에 가장 근접한 결과를 나타냈다. 이러한 차이는 현재의 실험 추출치에는 콘크리트 균열 등과 같은강성저감 요인을 포함하고 있지 않으며, 또한 FE 해석치는 비구조체 및 사용된 재료의 실제성능 등과 관련된 강성증가 요소를 포함하고있지 않기 때문이다.
        4,200원
        32.
        2012.02 구독 인증기관 무료, 개인회원 유료
        It was investigated the state information for the atmospheric conditions around Dang-jin industrial complex in Chungnam area may be polluted by the constructing steel industrial complex. It is aimed at characterization of the fine particulate matter and other air pollutants involved in it. Samples were collected two sites for monitoring point representing steel industrial complex and one site which is placed a remote and secluded from this industrial complex, and the concentration of PM10, heavy metals, and ion components were analyzed. As a results, PM10 average concentration was 64.6㎍/㎥ for the adjacent site before Hyundai Steel Company, 70.5㎍/㎥ in Bugok immigration settlement complex, and 56.5㎍/㎥ for Jeonggok-ri contrastive point. The distribution of heavy metals was detected as very low level for all sampling points. According to the result of statistical evaluation for the heavy metal analysis, variation range of Cu, Mn, Ca, Fe, and Mg were significant higher than others. Also, the seasonal concentration change trend of heavy metals was remarkable strong in spring and low in summer because of instable meteorological phenomena such as yellow dust happened in spring. Monthly changing pattern of a sulphate ion has kept unusually high level for summer period different other components. Relationship among PM10, heavy metal, and ion component were analyzed that high positive correlation coefficient for PM10 between Fe, Mn, Pb, Ca, Mg, Cd, Al in order and PM10 between NO3-, Cl- successively. Accordingly, it is suggested that a present atmospheric conditions of the surrounding area of Dang-jin steel industrial complex is considered to be good level. Although air pollutants in emissions from their complex were below the existing emission limit, it is regarded that the systematic and continuous research is needed to preserve clean air through atmospheric monitoring, source tracing research, and citizen's surveillance for the fine particulate matter.
        4,300원
        33.
        2011.09 구독 인증기관 무료, 개인회원 유료
        Heunginjimun as treasure No.1 is wooden structure of 2 story. This stucly presents an investigation on vibration characteristics of Heunginjimun in Seoul through ambient vibration test. The research team studied structural characteristics unlike general building and performed the test. Natural or environmental excitation as ambient vibration source is always present and hence the test implies a minimum interference with normal use of the structure. Natural frequencies, damping ratio and modes are identified and compared using two strategies, Frequency Domain Decomposition, Stochastic Subspace Identification techniques. The result shows that behavior and dynamic property of Heuninjimun.
        4,000원
        34.
        2011.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The synthesis behavior of nanoporous silica aerogel in the macroporous ceramic structure was observed using TEOS as a source material and glycerol as a dry control chemical additive (DCCA). Silica aerogel in the macroporous ceramic structure was synthesized via sono-gel process using hexamethyldiazane (HMDS) as a modification agent and n-hexane as a main solvent. The wet gel with a modified surface was dried at under ambient pressure. The addition of glycerol appears to give the wet gel a more homogeneous microstructure. However, glycerol also retarded the rate of surface modification and solvent exchange. Silica aerogel completely filled the macroporous ceramic structure without defect in the condition of surface modification (20% HMDS/nhexane at 36hr).
        4,000원
        35.
        2011.05 구독 인증기관·개인회원 무료
        Temperature and nutrition are the two most important environmental factors influencing growth and survival in immature insects. There is ample evidence of interactions between these two factors but still little is known how changes in thermal environment affect feeding and nutrient utilization insect ectotherms. The aim of this study is to investigate the potential effects of ambient temperature on food selection and post-ingestive nutritional physiology in a generalist-feeding caterpillar of Spodorptera litura. Two separate experiments were performed. The first was a food choice experiment in which caterpillars were maintained through their final larval stadium under one of three constant temperatures(20,25,30°) and given a choice between two nutritionally unbalanced diets that differed in protein(p) and carbohydrate(c) content (p42:c0 vs p7:c35 and p35:c7 vs p7:c35). In the second experiment, caterpillars were kept at the same thermal conditions as the first experiment but received a single diet from three no-choice feeding treatments(p35:c7,p21:c21and p7:c35). When raised at the highest temperature (30C), caterpillars from the choice experiment selected significantly more carbohydrate than those on lower temperatures whereas protein intake did not differ significantly between caterpillars across three test temperatures. Results from the no-choice experiment showed that lipid storage efficiency was reduced when caterpillars were maintained at the highest temperature(30C). In both experiments, growth rate increased progressively with rising temperature. However, there was a significant temperature-by-diet interaction, with growth rates increasing more rapidly on p21:c21 diet than on the other diets(p35:c7 and p7:c35). Our results demonstrate that caterpillars adjust their nutrient preference to meet the increased energetic demand at high ambient temperature.
        37.
        2007.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        4,000원
        38.
        2007.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
          Glass melting process is influenced by both control and observation factors, where control factors include quantity and mixing ratio of raw material, the amount of fuel and air in-take. Further observation factors include temperature and pressure at eac
        4,000원
        39.
        2007.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The present paper deals with gaseous carbon dioxide separation by a commercial adsorbent: X-type zeolite. Experimental work was carried out at an ambient condition focusing on how well meeting to the national guideline. A few types of reactor and material were examined, and practical capability was found in a granular bed type reactor with the flow of 2.5 CMM. An optimum design of reactor and adsorbent could provide the required concentration, less than 2500 ppm, for the continuous operation up to 10 hours. More work including automatic regeneration is now underworking.
        4,000원
        40.
        2006.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper is concerned with the natural periods of ambient vibration and eigenvalue analysis. Ambient vibration tests were conducted to four bearing-wall reinforced concrete buildings ranging from twelve to nineteen stories. The performance of modeling in eigenvalue analysis was investigated using consideration of rigidity out of the plane in the slab and the non-structural bearing wall. Measured natural period was also compared with the value by the KBC2005. Natural period of the short direction in eigenvalue analysis is well fitted with the measured one. In the other hand, Natural period of the long direction in eigenvalue analysis is slightly more overestimated than the measured one. Natural period of the long direction in eigenvalue analysis was found to be enhanced by considering the effect of the stiffness out of the plane of the slab and non-structural wall in the structural modeling.
        4,000원
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