• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.1
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• pp.1-11
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• 2010

Generation and transportation of runoff and pollutant loads within watershed generated eutrophication at Daecheong reservoir. To improve water quality at Daecheong reservoir, the best management practices should be developed and applied at upper watersheds for water quality improvement at downstream areas. In this study, two small watersheds of upper Daecheong reservoir were selected. The Long-Term Hydrologic Impact Assessment (L-THIA) model has been widely used for the estimation of the direct runoff worldwide. To apply the L-THIA ArcView GIS model was evaluated for direct runoff and water quality estimation at small watershed. And the Web-based Hydrograph Analysis Tool (WHAT) was used for direct runoff separating from total flow. As a result, the $R^2$ (Coefficient of determination) value and Nash-Sutcliffe coefficient value for direct runoff comparison at An-nae watershed were 0.81 and 0.71, respectively. And the $R^2$ value and Nash-Sutcliffe coefficient value at Wol-oe were 0.95 and 0.93. The $R^2$ value of BOD, TOC, T-N and T-P at An-nae watershed were BOD 0.94, TOC 0.81, T-N 0.94 and T-P 0.89. And the $R^2$ value of BOD, TOC, T-N and T-P at Wol-oe watershed were BOD 0.80, TOC 0.93, T-N 0.86 and T-P 0.65. The result that estimated pollutant loadings using the L-THIA ArcView GIS model reflected well the measured pollutant loadings except for T-P in Wol-oe watershed. With L-THIA ArcView GIS model, the direct runoff and non-point pollutant (NPS) loadings in the watershed could be analyzed through simple input data such as daily rainfall, land uses, and hydrologic soil group.

• Publications of The Korean Astronomical Society
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• v.32 no.1
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• pp.287-291
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• 2017

We present the results of our mid-infrared (MIR) observations of distant clusters of galaxies with AKARI. The wide-field of view of IRC/AKARI ($10^{\prime}{\times}10^{\prime}$) is ideally suited for studying dust-obscured star-formation (SF) activity of galaxies along the cosmic web in the distant universe. We performed a deep and wide-field $15{\mu}m$ (rest-frame ${\approx}8{\mu}m$) imaging observation of the RXJ1716+6708 cluster (z = 0.81) with IRC. We find that $15{\mu}m$-detected cluster member galaxies (with total infrared luminosities of $L_{IR}{\geq}10^{11}L_{\odot}$) are most preferentially located in the cluster outskirt regions, whilst such IR-luminous galaxies avoid the cluster centre. Our $H{\alpha}$ follow-up study of this field confirmed that a significant fraction of $15{\mu}m$-detected cluster galaxies are heavily obscured by dust (with $AH{\alpha}$>3 mag in extreme cases). The environment of such dusty star-burst galaxies coincides with the place where we see a sharp "break" of the colour-density relation, suggesting an important link between dust-obscured SF activity and environmental quenching. We also report the discovery of a new cluster candidate around a radio galaxy at z = 1.52 (4C 65.22), where we obtained one of the deepest IRC imaging datasets with all the nine filters at $2-24{\mu}m$. This field will provide us with the final, excellent laboratory for studying the dust-enshrouded SF activity in galaxies along the cosmic web at the critical epoch of cluster galaxy evolution with AKARI.

• Journal of Korean Academy of Nursing Administration
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• v.19 no.1
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• pp.87-94
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• 2013

Purpose: The purpose of this study was to provide a basis for non-humidified low flow oxygen by nasal cannula and to provide a guide for consistent care in nursing practice. Methods: A methodological study on the development of guidelines with experts' opinions on collected items, framing PICO questions, evaluating and synthesizing texts which were searched with the key words (low flow oxygen, nasal cannula, humidification of oxygen, guideline) from web search engines. Results: Of the 45 researched texts on the web, 9 texts relevant to the theme were synthesized and evaluated. All patients with humidified or non-humidified oxygen therapy reported that they had no discomfort. Conclusion: The results indicate that there are no tangible grounds for patients' perceived differences between the humidified and non-humidified oxygen under 4L/min supplied by nasal cannula. with oxygen. Therefore, non-humidification oxygen therapy is strongly advised when suppling under 4L/min oxygen by nasal cannula (recommended grade A).

• Applied Chemistry for Engineering
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• v.17 no.3
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• pp.255-259
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• 2006

Ultrafine fibers having approximately 800 nm diameter were prepared by an electrospinning method from cellulose acetate. Cellulose acetate dissolved in acetone solutions were electrospun at various conditions. The cellulose polymer solutions of various concentrations were applied under different voltages, flow rates, and tip-to-collector distances (TCD). The diameter of fibers depended on the electrospinning parameters such as its viscosity. The fibers were not formed from the polymer solutions less than 12.0 cP viscosity. The minimum diameter was 800 nm at 12.5 wt% of polymer concentration, 12 kV of voltage, $100{\mu}L/min$ of flow rate, and 7.5 cm TCD.

• Journal of Information Processing Systems
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• v.4 no.4
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• pp.159-168
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• 2008

Human-Robot Interaction (HRI), based on already well-researched Human-Computer Interaction (HCI), has been under vigorous scrutiny since recent developments in robot technology. Robots may be more successful in establishing common ground in project-based education or foreign language learning for children than in traditional media. Backed by its strong IT environment and advances in robot technology, Korea has developed the world's first available e-Learning home robot. This has demonstrated the potential for robots to be used as a new educational media - robot-learning, referred to as 'r-Learning'. Robot technology is expected to become more interactive and user-friendly than computers. Also, robots can exhibit various forms of communication such as gestures, motions and facial expressions. This study compared the effects of non-computer based (NCB) media (using a book with audiotape) and Web-Based Instruction (WBI), with the effects of Home Robot-Assisted Learning (HRL) for children. The robot gestured and spoke in English, and children could touch its monitor if it did not recognize their voice command. Compared to other learning programs, the HRL was superior in promoting and improving children's concentration, interest, and academic achievement. In addition, the children felt that a home robot was friendlier than other types of instructional media. The HRL group had longer concentration spans than the other groups, and the p-value demonstrated a significant difference in concentration among the groups. In regard to the children's interest in learning, the HRL group showed the highest level of interest, the NCB group and the WBI group came next in order. Also, academic achievement was the highest in the HRL group, followed by the WBI group and the NCB group respectively. However, a significant difference was also found in the children's academic achievement among the groups. These results suggest that home robots are more effective as regards children's learning concentration, learning interest and academic achievement than other types of instructional media (such as: books with audiotape and WBI) for English as a foreign language.

• Journal of Ecology and Environment
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• v.37 no.4
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• pp.225-229
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• 2014

Feeding behavior of Temora turbinata was investigated through laboratory experiments with special emphasis on its food preference and consequent clearance rate on diatom and microbial components given as common natural food assemblage of coastal area (Uchiumi, Uwa Sea, Japan). Among available prey items, T. turbinata showed the highest clearance rate for Thalassiosira spp. ($0.23{\pm}0.08L\;Temora^{-1}day^{-1}$) followed by Chaetoceros spp. ($0.11{\pm}0.03L\;Temora^{-1}day^{-1}$), but clearance rates for other diatom, Nitzschia spp. was lower (0.03 to $0.07L\;Temora^{-1}day^{-1}$). Bacterial abundances showed no response against 24-h feeding of T. turbinata. Feeding of T. turbinata on heterotrophic nanoflagellates (HNF) was apparent when clearance rates of T. turbinata on diatoms were relatively low, but T. turbinata did not consume HNF as well as ciliates with Thalassiosira spp. of which clearance rate was highest. The results suggest that HNF and ciliates are possible supplementary prey item for T. turbinata, but their contribution as food sources can be limited by the presence of other prey items such as preferable diatom species.

• Journal of computational fluids engineering
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• v.18 no.3
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• pp.42-50
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• 2013

The supersonic airplane with flapped biplane, Busemann biplane equipped flap, is superior to drag and noise reduction due to wave cancelation effect between upper and lower airfoils. In this study, it is numerically calculated and analyzed the lift, drag and lift to drag ratio of flapped biplane with respect to various the length and angle of the flap. Euler solver of EDISON CFD, web based computational fluid dynamic solver for the purpose of education, is employed. Depending on the length of the flap, lift and drag increase linearly, and there exists the optimum flap angle which maximize the lift-to-drag ratio at the freestream mach 2.0 on-design condition. The predictable relational expression is driven as liner equation. As a results of comparison with drag of flapped biplane, Busemann biplane, and diamond airfoil with the same lift, the drag of flapped biplane is 88.76% lower than that of the Busemann biplane and 70.67% lower than that of the diamond airfoil. In addition, the change of pressure is compared to confirm the noise reduction effect of flapped biplane at h/c=5 of lower airfoil. The shock strength of flapped biplane is smaller than that of other airfoils.

• Journal of Digital Convergence
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• v.7 no.4
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• pp.127-140
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• 2009

This dissertation aims to empirically analyze the factors that determine the market competitiveness that would enable SaaS enterprises to survive. The contents of this dissertation includes; (l)analysis of factors that determine market competitiveness of domestic SaaS enterprises, (2)structural analysis of factors that determine the market competitiveness of SaaS enterprises on the their performance. Results of analysis of this dissertation are as follows. First, the factors that determine market competitiveness of SaaS enterprises were found to include (l)enterprise management competence, (2)competence for technological possession, (3)reliability and safety, (4)customer management competence, and (S)competence to cope with external environment of the enterprise. Second, the outcome of structural analysis of factors that determine the market competitiveness of SaaS enterprises on the their performance illustrated that (l)enterprise management competence and (2)competence for technological possession has structural relationship of imparting influence on the (6)enterprise performance by the full medium of (3)reliability and safety, (4)customer management competence, and (5)competence to cope with external environment of enterprise.

• Educational Technology International
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• v.18 no.2
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• pp.193-213
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• 2017

This study aimed to explore online learning profiles of in-service teachers in South Korea, focusing on video lecture and discussion activities. A total of 269 teachers took an online professional development course for 14 days, using an online learning platform from which web log data were collected. The data showed the frequency of participation and the initial participation time, which was closely related to procrastinating behaviors. A cluster analysis revealed three online learning profiles of in-service teachers: procrastinating (n=42), passive interaction (n=136), and active learning (n=91) clusters. The active learning cluster showed high-level participation in both video lecture and discussion activities from the beginning of the online course, whereas the procrastinating cluster was seldom engaged in learning activities for the first half of the learning period. The passive interaction cluster was actively engaged in watching video lectures from the beginning of the online course but passively participated in discussion activities. As a result, the active learning cluster outperformed the passive interaction cluster in learning achievements. The findings were discussed in regard to how to improve online learning environments through considering online learning profiles of in-service teachers.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.1
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• pp.96-103
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• 2009

This paper presents a L3 mobile terminal platform of the mobile terminal system which is a subsystem of HMm(Hig-speed Mobile Multimedia) system, which layer 3 control protocols such as RC(Radio Control), SC(Session Control), MC(Mobility Control) and application services such as VOD, FTP, VoIP for a multimedia mobile terminal are implemented on. The hardware platform is based on PXA255 and supports various interfaces and multimedia devices, and under the platform, an embedded Linux generated by the self-maden cross-toolchain, L3 control protocols and application programs were installed. The operation of HMm system under the HMm testbed has shown that this platform successfully supported SIP services, web browsing services, streaming services and etc as well as call processing. It could be the reference of the upcoming Fourth-Generation mobile terminal which the multimedia functionality will be enforced.