• Journal of Advanced Marine Engineering and Technology
• /
• v.29 no.4
• /
• pp.391-398
• /
• 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.

• Korean Journal of Remote Sensing
• /
• v.24 no.5
• /
• pp.389-396
• /
• 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.

• Proceedings of the SAREK Conference
• /
• 2006.06a
• /
• pp.596-601
• /
• 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.

• The Journal of Information Systems
• /
• v.30 no.2
• /
• pp.1-27
• /
• 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.

• Journal of Life Science
• /
• v.34 no.2
• /
• pp.113-121
• /
• 2024

Endoplasmic reticulum (ER) stress responses are markedly induced during toxic responses caused by various chemical substances, including difenoconazole, but no research has been conducted on 1,2,3-trichloropropane (TCP), a chemical that is generally used in agriculture and industry, which induces hepatotoxicity. Therefore, in this study, the changes in indicators for hepatotoxicity, apoptosis, and ER stress were analyzed in TCP-treated Sprague Dawley (SD) rats to study the regulatory mechanism of ER stress during the hepatotoxicity. The TCP-treated group decreased in body weight and dietary intake compared to the vehicle-treated group, and necrosis and vacuolation increased significantly in liver histology. In addition, the expression of apoptosis-related factors, including Bax/Bcl-2 and cleaved caspase (Cas)-3/Cas-3 increased significantly in the TCP-treated group compared to the vehicle-treated group. In the analysis of ER stress response indicators, the expression of C/EBP homologous protein (CHOP), phospho-eukaryotic translation initiation factor 2 alpha subunit (eIF2α), and phospho-inositol-requiring enzyme 1α (IRE1α) increased only in the TCP100-treated group and decreased in the TCP200-treated group. However, the transcriptions of growth arrest and DNA damage-34 (GADD34) increased in the TCP200-treated group, while Spliced X-box binding protein-1 (XBP1s) and unspliced XBP1(XBP1u) decreased in the same group. These results suggest that the ER stress response is successfully triggered during the hepatotoxicity induced by TCP treatment through the alternative regulation of the unfolded-protein response (UPR) pathway.

• Food Science of Animal Resources
• /
• v.34 no.5
• /
• pp.614-621
• /
• 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.

• Food Science of Animal Resources
• /
• v.37 no.5
• /
• pp.646-653
• /
• 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.

• Journal of the Korea Convergence Society
• /
• v.8 no.2
• /
• pp.291-297
• /
• 2017

This study was aimed to secure the basis for developing the hangbang-tea may help promote healthy blood vessels by natural herbal ingredients formulated in accordance with the basic principles of oriental medicinal theory. We investigated the vessels contracted by concentrations and safety assessment carried out by the cell viability of Taraxaci Herba, Gardeniae Fructus, Chrysanthemum indicum and Lonicerae Flos composition and concentration. We found cell survival were higher than the control group show a beneficial trend in the growth of normal liver and kidney cells. As a results of this study will be the basis to develop the hangbang-tea differentiated in the future oriental medicine resources. Medicinal resources will be hangbang-tea based on clinical trials utilizing herbal western and oriental medicine convergence principle and vascular relaxation mechanism.

• Journal of Korea Water Resources Association
• /
• v.32 no.1
• /
• pp.3-13
• /
• 1999

In this study, an alternative spatial analysis method against conventional methods such as Thiessen method, Inverse Distance method, and Kriging method, named Spatial-Analysis Neural-Network (SANN) is presented. It is based on neural network modeling and provides a nonparametric mean estimator and also estimators of high order statistics such as standard deviation and skewness. In addition, it provides a decision-making tool including an estimator of posterior probability that a spatial variable at a given point will belong to various classes representing the severity of the problem of interest and a Bayesian classifier to define the boundaries of subregions belonging to the classes. In this paper, the SANN is implemented to be used for analyzing a mean annual precipitation filed and classifying the field into dry, normal, and wet subregions. For an example, the whole area of South Korea with 39 precipitation sites is applied. Then, several useful results related with the spatial variability of mean annual precipitation on South Korea were obtained such as interpolated field, standard deviation field, and probability maps. In addition, the whole South Korea was classified with dry, normal, and wet regions.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2005.05b
• /
• pp.1199-1203
• /
• 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.