• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.3
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• pp.51-64
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• 2015

Climate change will make significant impact on species distribution in forest. Pinus koraiensis which is commonly called as Korean Pine is normally distributed in frigid zones. Climate change which causes severe heat could affect distribution of Korean pine. Therefore, this study predicted the distribution of Korean Pine and the suitable habitat area with consideration on uncertainty by applying climate change scenarios on an ensemble model. First of all, a site index was considered when selecting present and absent points and a stratified method was used to select the points. Secondly, environmental and climate variables were chosen by literature review and then confirmed with experts. Those variables were used as input data of BIOMOD2. Thirdly, the present distribution model was made. The result was validated with ROC. Lastly, RCP scenarios were applied on the models to create the future distribution model. As a results, each individual model shows quite big differences in the results but generally most models and ensemble models estimated that the suitable habitat area would be decreased in midterm future(40s) as well as long term future(90s).

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.9
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• pp.623-629
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• 2017

Flow structure and mixing characteristics in a micro combustor with a multi-hole baffle were numerically studied using the Reynolds stress model. The multi-hole baffle has geometrical features to produce multiple three-dimensional vortices inside combustion chamber. When the thickness of the baffle's geometrical factors changes, variations of vortical structures occur variously. Among these vortices, the vortex generated from the fuel stream exerts a critical influence on the mixing enhancement. The three-dimensional vortical structure, in its development state, was strongly dependent on the baffle thickness. In particular, as the baffle thickness decreases to values less than the diameter of the fuel hole, the jet stream in baffle holes changes from the parabolic to saddleback profile type. The sizes of recirculation zones inside combustion chamber and the mixing state were closely affected by the structure of the jet streams.

• Journal of Ocean Engineering and Technology
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• v.22 no.3
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• pp.8-17
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• 2008

Wrenching climatic changes due to ecocide and global wanning are producing a natural disaster. Coastal zones have been damaged by typhoons and accompanying storm surges. Severe waves, and destruction of the environment are adding to the severity of coastal disasters. There has been an increased interest in these coastal zone problems, and associated social confusion, after the loss of life and terrible property damage caused by typhoon Maemi. Especially if storm surges coincide with high ticks, the loss of life and property damage due to high waters are even worse. Therefore, it is desirable to accurately forecast not only the timing of storm surges but also the amount water level increase. Such forecasts are very important from the view point of coastal defense. In this study, using a numerical model, storm surge was simulated to examine its fluctuation characteristics for the coastal area behind Masan Bay, Korea. In the numerical model, a moving boundary condition was incorporated to explain wave run-up. Numerically predicted inundation regimes and depths were compared with measurements from a field survey. Comparisons of the numerical results and measured data show a very good correlation. The numerical model adapted in this study is expected to be a useful tool for analysis of storm surges, and for predicting inundation regimes due to coastal flooding by severe water waves.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.11
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• pp.1011-1022
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• 2014

Currently, the wireless network environment of air node is constructed mainly of ground relay station. However, as the Korean Peninsula is composed of 70% mountainous region, there are multiple shadow zones. This is calling for effective measures to prevent aircraft from losing communication link during low-mid altitude missions. In this article we propose the utilization of Bezier Curve for estimation of aircraft flight path and control method for entering shadow zone. This method successfully estimated aircraft track, and analyzed the existence, disseminated the warning, and took measures to avoid the shadow zone before entering. This article, suggested after simulated experiments, proves that the method enables seamless communication during air operations.

• Journal of Korea Game Society
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• v.13 no.2
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• pp.39-48
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• 2013

In MMORPGs(Massively Multi-player Online Role-Playing Games) a large number of players actively interact with one another in a virtual world. Therefore MMORGs must be able to quickly process real-time access requests and process requests from numerous gaming users. A key challenge is that the workload of the game server increases as the number of gaming users increases. To address this workload problem, many developers apply with distributed server architectures which use dynamic map partitioning and load balancing according to the server function. Therefore most MMORPG servers partition a virtual world into zones and each zone runs on multiple game servers. These methods cause of players frequently move between game servers, which imposes high overhead for data updates. In this paper, we propose a new architecture that apply with an arithmetic server dedicated to data operation. This architecture enables the existing game servers to process more access and job requests by reducing the load. Through mathematical modeling and experimental results, we show that our scheme yields higher efficiency than the existing ones.

• Archives of Plastic Surgery
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• v.38 no.5
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• pp.590-593
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• 2011

Purpose: Surgical site infections (SSIs) are the third most frequently reported nosocomial infection. Of these SSIs, mostly were confined to the incision associated with underlying disease as diabetes, cigarette smoking, systemic steroid use, obesity, operating room environment, suture and surgical technique. This study has been planned to reduce the SSIs by using Vicryl $plus^{(R)}$ (Ethicon, USA) which contains triclosan, a broad-spectrum antibacterial agent, into the infected wound to evaluate whether or not Vicryl $plus^{(R)}$ (Ethicon, USA) is effective to nosocomial bacteria using a zone of inhibition assay. Methods: We did a comparison of Vicryl $plus^{(R)}$ suture (with triclosan) size 2-0, 5-0 with $Vicryl^{(R)}$ suture (without triclosan) size 4-0 each as treatment and control group, applied in Mueller-Hinton agar infected by following mircroorganisms: Methicillin-sensitive $Staphylococcus$ $aureus$ (MSSA), Methicillin-resistant $Staphylococcus$ $aureus$ (MRSA), Acinetobacter baumanii, $Escherichia$ $coli$, Enterobacter faecalis, Pseudomonas aeruginosa, Candida albicans. Cultures were made of the selected mircroorganisms, seeding the study strain in agar plates for 24 and 48-hour period in an oven at $37^{\circ}C$ followed by zone of inhibition assay. Results: Vicryl $plus^{(R)}$ group has demonstrated to create a zone of inhibition against MRSA, MSSA and $A.$ $baumanii$, but no effect on $E.$ $faecalis$, $P.$ $aeruginosa$, $C.$ $albicans$. Vicryl $plus^{(R)}$ suture size 2-0 also had antibactericidal effect while Vicryl $plus^{(R)}$ suture size 5-0 did not. $Vicryl^{(R)}$ group had no zones of inhibition showing colonization at all mircroorganisms. Conclusion: Our results seem to warrant the use of Vicryl $plus^{(R)}$ as absorbable buried suture when concerning SSIs as a prophylaxis against surgical nosocomial infection.

• Journal of Korean Society of Transportation
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• v.26 no.3
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• pp.109-117
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• 2008

The first phase of School Zone Improvement Project introduced to enhance the safety of school-routes were completed by 2007 and the second phase of the project will be continued from 2008 to 2012. Since a huge budget is required for the project, there is a need to evaluate how many child-related crashes were reduced through the project, prior to the implementation of the second phase. Therefore, this study aims to analyze the influence of the School Zone Improvement Project on reduction in child-related crashes with data collected from the database of the National Police Agency. This study employed a Before-and-After study with comparison group to assess how many crashes were reduced. The results showed that the number of child-related crashes were decreased by 10, which is about 39% reduction in crash frequencies. With respect to the land use characteristics of school zones, the number of reduced crashes in residential zone, commercial zone, and mixed zone were 2.41, 3.8, and 0.5, respectively. The results may provide a significant implication for the second phase of the project that there is a need to establish different plans for improvement project with respect to land use characteristics.

• The Journal of the Convergence on Culture Technology
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• v.6 no.4
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• pp.139-147
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• 2020

The number of deaths from child traffic accidents in Korea is currently higher than the average figure of OECD members, and attention needs to be paid to reduce the school zone accident rate. According to the TAAS statistics of the Traffic Accident Analysis System, the number of deaths from traffic accidents in children (under 12 years of age) in Korea has been steadily decreasing recently, but the number of accidents and injuries has been continuously increasing and decreasing. With the number of accidents and injuries of children in Korea continuing to increase and decrease, the number of traffic accidents, deaths, and injuries of children in the school zone (under 12 years of age) has also been on the rise since 2019. Therefore, we were different from the preceding study (Study on Improvement through School Zone Accident Risk Survey, Study on Improvement of Children's Traffic Safety Facilities through Simulation Program). In order to prevent traffic accidents among school zones, which have the highest accident rate among children, a survey was conducted on traffic safety facilities and safety awareness of drivers. After that, we will analyze the problems and present measures for improving traffic safety in the school zone and improving drivers' safety awareness.

• The Korea Journal of Herbology
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• v.28 no.6
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• pp.119-127
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• 2013

Objectives : ${\beta}$-Asarone (BAS) is an active ingredient in Acori Rhizoma. This study investigated anti-neuroinflammatory and memory ameliorating effects of BAS in systemic lipopolysaccharide (LPS)-treated C57BL/6 mice. Methods : BAS was administered orally at doses of 7.5, 15, and 30 mg/kg for 3 days prior to LPS (3 mg/kg, intraperitoneal) injection. Pro-inflammatory cytokine mRNA, including tumor necrosis factor-${\alpha}$ (TNF-ㅍ), interleukin (IL)-$1{\beta}$ and IL-6, was measured in hippocampus tissue using real-time polymerase chain reaction at 4 h after the LPS injection. An ameliorating effect of 30 mg/kg BAS on learning and memory impairment in the LPS-treated mice was verified using the Morris water maze test. Results : BAS significantly attenuated up-regulation of TNF-${\alpha}$, IL-$1{\beta}$, and IL-6 mRNA in hippocampus tissue of the LPS-treated mice. In acquisition training test, BAS improved learning performance of the LPS-treated mice with a significant decrease of escape latency to the platform. In memory retention test, BAS also ameliorated memory impairment of the LPS-treated mice with a significant increase of swimming time in zones neighboring to the platform, number of target heading, and memory score. Conclusion : The results suggest that inhibition of pro-inflammatory cytokines and neuroinflammation in the hippocampus by BAS could be one of the mechanisms for BAS-mediated ameliorating effect on learning and memory impairment in LPS-treated mice.

• Dementia and Neurocognitive Disorders
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• v.22 no.1
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• pp.28-42
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• 2023

Background and Purpose: We investigated the correlation between the deep distribution of white matter hyperintensity (WMH) (dWMH: WMH in deep and corticomedullary areas, with minimal periventricular WMH) and a positive agitated saline contrast echocardiography result. Methods: We retrospectively recruited participants with comprehensive dementia evaluations, an agitated saline study, and brain imaging. The participants were classified into two groups according to WMH-distributions: dWMH and dpWMH (mainly periventricular WMH with or without deep WMH.) We hypothesized that dWMH is more likely associated with embolism, whereas dpWMH is associated with small-vessel diseases. We compared the clinical characteristics, WMH-distributions, and positive rate of agitated saline studies between the two groups. Results: Among 90 participants, 27 and 12 met the dWMH and dpWMH criteria, respectively. The dWMH-group was younger (62.2±7.5 vs. 78.9±7.3, p<0.001) and had a lower prevalence of hypertension (29.6% vs. 75%, p=0.008), diabetes mellitus (3.7% vs. 25%, p=0.043), and hyperlipidemia (33.3% vs. 83.3%, p=0.043) than the dpWMH-group. Regarding deep white matter lesions, the number of small lesions (<3 mm) was higher in the dWMH-group(10.9±9.7) than in the dpWMH-group (3.1±6.4) (p=0.008), and WMH was predominantly distributed in the border-zones and corticomedullary areas. Most importantly, the positive agitated saline study rate was higher in the dWMH-group than in the dpWMH-group (81.5% vs. 33.3%, p=0.003). Conclusions: The dWMH-group with younger participants had fewer cardiovascular risk factors, showed more border-zone-distributions, and had a higher agitated saline test positivity rate than the dpWMH-group, indicating that corticomedullary or deep WMH-distribution with minimal periventricular WMH suggests embolic etiologies.