• Journal of Advanced Marine Engineering and Technology
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• 제29권4호
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• pp.391-398
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• 2005

In this investigation, turbulent premixed combustion and flame front propagation in a gas turbine combustion chamber is studied. Direct numerical simulation of turbulent reacting flows demands extremely high computational resources, especially in more complicated geometry. The alternative choice may be left for Large Eddy Simulation (LES) by which only large scales are solved directly. In combustion problems, capturing the large scales' behavior without solving the details of small scales is a difficult task. Using a transport equation for description of the flame front propagation and therefore avoiding the calculation of inner flame structure is the basic idea of this study. For this purpose. the so-called G-equation has been used by which any iso-level of the G variable provides the flame location. A comparison with the experiment indicates that the present method can predict a turbulent velocity field and also capture a instantaneous 3-dimensional flame structure.

• 대한원격탐사학회지
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• 제24권5호
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• pp.389-396
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• 2008

In these days, various kinds of web applications based on web 2.0 paradigm have been developed. In web 2.0 paradigm pursuing participation, sharing, and openness on the web-as-platform, web mapping or web GIS application are regarded as top most applications, so that web applications, handling geo-spatial contents, with user-interaction interface and search engine of high performance have been provided for both public users and expert users in the special domains. Public and industrial needs for web mapping mashup application by open API, linked with the practical web computing technologies, are gradually increasing. In this study, a user interface in mashup for geo-spatial feature generation was implemented by using mainly Google maps API. Spatial database resources in this implementation are those of Google mapping server. As the results, public users on web client can create their own geo-spatial data sets in web vector formats, without the help of any GIS tools or access to proprietary databases. It is concluded that web-based mashup application in client-side using open API can be used as an alternative for geo-browsing system or portable feature generation system.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.596-601
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• 2006

Because of insufficiency of energy resources and pollution of environment, it is necessary to develop alternative energy sources. Nuclear fission energy is used widely for source of electric Power but being restricted due to radioactivity problem. Nuclear fission is highlighted as the new generation of nuclear energy and researched worldwide because of low risk of radiation effect. The representatives of fusion research is China's EAST, KSTAR of Korea and ITER of world. Korea Superconducting Tokamak Advanced Research(KSTAR) project is on progress for the completion in August, 2007. In this study, the research of utility system for KSTAR be carried out. The utility system of KSTAR is consist of water cooling & heating system, $N_2$ gas system, DI water system, service water system and instrument air & auto control system. The progress of KSTAR utility system is under commissioning state after construction completion. The optimal operation scenario will be verified during commissioning and adopted to the KSTAR operation.

• 한국정보시스템학회지:정보시스템연구
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• 제30권2호
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• pp.1-27
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• 2021

Purpose Even if many startups firms have developed innovative items and a potential for success, they often have a limited financial resources, which makes them difficult to do business. To overcome this financial difficulty, startups have used one of fintech services, called crowdfunding that can be a good alternative to solving the difficulty of financing. The purpose of this study is to empirically validate the proposed research model that investigates the reasons of trusting crowdfunding platform, which positively leads to two outcomes - intention to participate and word-of-mouth for reward-based crowdfunding project. Design/methodology/approach We proposed several factors categorized as trust, information quality, and platform traits that have a positive impact on trust of crowdfunding platform, which positively leads to intention to participate and word-of-mouth of crowdfunding. The collected(n=285) from individuals who have participated in crowdfunding project was analyzed with SmartPLS 3.0 to test proposed hypotheses. Findings The results showed that all proposed variables (website reputation, crowdfunding familiarity, digital storytelling, information quality, and interaction) had a significant impact on crowfunding platform trust with exception of product differentiation. In addition, crowfunding platform trust was positively associated with participating intention and word-of-mouth. Based on findings, we discussed the research results and implication alone with a direction for future studies.

• 생명과학회지
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• 제34권2호
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• pp.113-121
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• 2024

ER (Endoplasmic reticulume) 스트레스반응은 difenoconazole 등과 같은 다양한 독성물질에 의한 독성반응 동안에 유도되지만, 농업 및 산업에서 전반적으로 사용되는 화학물질로 간독성(Hepatotoxicity)을 유도하는 1,2,3-Trichloropropane (TCP)와의 연관성은 연구된 바 없다. 따라서, 본 연구에서는 TCP처리로 유발된 간독성(Hepatotoxicity) 유발과정 동안에 ER스트레스의 유발기전에 대해 연구하기 위하여, TCP로 처리된 SD(Sprague Dawley)랫드에서 간독성, apoptosis 그리고 ER스트레스에 대한 지표들의 변화를 분석하였다. 그 결과, TCP 처리그룹은 Vehicle 처리그룹에 비하여 체중과 식이 섭취량이 감소하였고, 간 조직에서 괴사(Necrosis)와 공포화(Vaculation) 등이 유의적으로 증가하였다. 또한, apoptosis 관련 인자인 Bax/Bcl-2와 Cleaved Caspase-3(Cas-3)/Cas-3의 발현은 Vehicle 처리그룹보다 TCP 처리그룹에서 유의적으로 증가하였다. ER스트레스 반응지표 분석에서, C/EBP homologous protein (CHOP), p-eukaryotic translation initiation factor 2 alpha subunit (eIF2α), p-iniositor-requiring enzyme 1α (IRE1α)의 발현은 TCP100 처리그룹에서만 증가하였다. 하지만 Growth arrest and DNA damage-34 (GADD34)와 X-box binding protein-1 (XBP1)의 전사는 TCP200 처리그룹에서 유의적으로 변화되었다. 따라서, 이러한 결과는 ER스트레스반응은 TCP 처리에 의해 유도된 간독성과정 동안에 unfolded protein response (UPR) pathway의 조절을 통해 성공적으로 유도됨을 제시하고 있다.

• 한국축산식품학회지
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• 제34권5호
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• pp.614-621
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• 2014

This study was conducted to isolate and characterize bacteriocin-producing bacteria against Clostridium perfringens (C. perfringens) from domestic animals to determine their usefulness as probiotics. Bacteriocin-producing bacteria were isolated from pig feces by the spot-on-lawn method. A total of 1,370 bacterial stains were isolated, and six were tentatively selected after identifying the inhibitory activity against the pathogenic indicator C. perfringens KCTC 3269 and KCTC 5100. The selected strains were identified as Enterococcus faecalis (E. faecalis) by 16s rRNA sequencing. Most of the isolated bacterial strains were resistant to 0.5% bile salts for 48 h and remained viable after 2 h at pH 3.0. Some E. faecalis also showed strong inhibitory activity against Listeria monocytogenes KCTC 3569, KCTC 3586 and KCTC 3710. In the present study, we finally selected E. faecalis AP 216 and AP 45 strain based on probiotic selection criteria such as antimicrobial activity against C. perfringens and tolerance to acid and bile salts. The bacteriocins of E. faecalis AP 216 and AP 45 strains were highly thermostable, showing anticlostridial activities even after incubation at $121^{\circ}C$ for 15 min. These bacteriocin-producing bacteria and/or bacteriocins could be used in feed manufacturing as probiotics as an alternative to antibiotics in the livestock industry.

• 한국축산식품학회지
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• 제37권5호
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• pp.646-653
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• 2017

Alcalase hydrolysis of liquid egg white was used to produce 5-hydroxytryptophan (HTP) under various conditions and investigate the sleep-potentiating activity of liquid egg white hydrolysate (LEH) on pentobarbital-induced sleep. Alcalase hydrolysis yielded the highest content of 5-HTP ($13.50{\mu}g/mL$), while neutrase hydrolysis showed the lowest 5-HTP content ($5.23{\mu}g/mL$). The liquid egg white to water ratio (1:1) was optimal for the production of 5-HTP with high amino-nitrogen (A-N) content and degree of hydrolysis. The 5-HTP, amino-nitrogen, and degree of hydrolysis increased until 24 h of hydrolysis and slightly increased thereafter during hydrolysis with 2% and 5% enzyme addition. 5-HTP administration at doses of 6 and 9 mg/kg significantly increased sleep duration and decreased sleep latency time compared to that in the control (p<0.05). LEH (150 mg/mouse), which was equivalent to 5-HTP at 6 mg/kg, significantly decreased sleep latency time and increased sleep duration time compared to that in the control (p<0.05). Oral administration of LEH showed sleep-potentiating effects because of 5-HTP. The sleep-potentiating activity of LEH may have occurred through 5-HTP in our pentobarbital-induced sleep model. LEH may be a valuable alternative to sleep enhancement and may be used as a sleep-potentiating agent.

• 한국융합학회논문지
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• 제8권2호
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• pp.291-297
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• 2017

본 연구는 혈관 활성에 도움이 되는 한방차를 개발하고, 섭취효능에 대한 동 서 융합적인 접근 필요성에 대한 기초자료로 사용하고자 하였다. 이에 따라 기미론에 따라 혈관 활성을 가질 수 있는 포공영(Taraxaci Herba), 치자(Gardeniae Fructus), 감국(Chrysanthemum indicum) 및 금은화(Lonicerae Flos)를 선정하여 조성물을 만들고 각각 재료와 조성물의 영양성분, 조성물이 세포활성에 미치는 영향 및 수축혈관에 대한 이완정도를 분석하였다. 기미론적 원리에 따른 한방차 조성물은 체내 열을 제거하고 혈액순환을 촉진할 수 있는 효능을 가지고 있음을 알 수 있었다. 네 가지를 재료를 배합한 조성물은 세포활성에 유익한 영향을 미치고 있음을 확인하였다. 또한 조성물은 수축혈관에 대해 이완효과를 가지고 있었고 조성물의 농도가 높을수록 수축된 혈관의 이완효과가 큰 것으로 관찰되어 이 조성물이 혈관 활성에 긍정적 영향을 주고 있음을 확인하였다. 본 연구는 한방차 조성물의 기미 특성과 현대 영양학의 특성이 융합된 섭취효능을 제시하였다고 사료된다.

• 한국수자원학회논문집
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• 제32권1호
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• pp.3-13
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• 1999

본 연구에서는 공간 분포의 해석을 위하여 일반적으로 사용되어 오던 Thiessen 또는 Kriging 법들을 대체할 수 있는 새로운 모형인 SANN(Spatial-Analysis Neural-Network)을 소개한다. 이 모델은 신경망 기법을 이용한 비매개 변수법의 일종으로 미측정 기점의 평균값 뿐만 아니라 분산, 왜도 등의 고차 통계치를 제공하여 준다. 또한 어떤 기점에서의 공간변수의 값이 그 심각도에 따른 미리 지정된 여러 분류들 중 각각의 분류에 속할 확률값과 전체 공간을 각 분류에 따라 가장 최적하게 분류경제(class boundary)를 선정하여줄 수 있는 Bayesian 계급분류기(Classifier)를 제공하는 의사결정(decision-making) 역할도 수행할 수 있다. 본 연구에서는 제안된 SANN모형의 외삽기(interpolator)를 사용하여 관측 기점의 연평균 강우량을 대상 유역 전체의 공간적으로 분포시키고 또한 각 지점의 예측 오류를 산정하며, Bayesian 분류기를 사용하여 대상유역을 가장 적절하게 건조, 보통, 습윤 지역으로 분류하는 방법을 제시하여 본다. 본 연구에서는 39개 강우 계측 지점을 이용하여 우리나라의 연평균 강우의 공간 해석에 응용하여 본다. 결과적으로 연평균 강우량의 공간 분포, 표준편차, 그리고 확률도를 얻었다. 더불어 우리나라 전역을 건조, 보통, 습윤 지역으로 분류하여 보았다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회 논문집
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• pp.1199-1203
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• 2005

Combined sewer overflows(CSOs) are themselves a significant source of water pollution. Therefore, the control of urban drainage for CSOs reduction and receiving water quality protection is needed. Examples in combined sewer systems include downstream storage facilities that detain runoff during periods of high flow and allow the detained water to be conveyed by an interceptor sewer to a centralized treatment plant during periods of low flow. The design of such facilities as stormwater detention storage is highly dependant on the temporal variability of storage capacity available(which is influenced by the duration of interevent dry periods) as well as the infiltration capacity of soil and recovery of depression storage. As a result, a contiunous approach is required to adequately size such facilities. This study for the continuous long-term analysis of urban dranage system used analytical Probabilistic model based on derived probability distribution theory. As an alternative to the modeling of urban drainage system for planning or screening level analysis of runoff control alternatives, this model have evolved that offer much ease and flexibility in terms of computation while considering long-term meteorology. This study presented rainfall and runoff characteristics or the subject area using analytical Probabilistic model. Runoff characteristics manifasted the unique characteristics of the subject area with the infiltration capacity of soil and recovery of depression storage and was examined appropriately by sensitivity analysis. This study presented the average annual COSs and number of COSs when the interceptor capacity is in the range 3xDWF(dry weather flow). Also, calculated the average annual mass of pollutant lost in CSOs using Event Mean Concentration. Finally, this study presented a dicision of storage volume for CSOs reduction and water quality protection.