• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권5호
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• pp.1976-1997
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• 2016

This paper investigates the problem of co-tier interference mitigation for dynamic small- cell networks, in which the load of each small-cell varies with the number of active associated small-cell users (SUs). Due to the fact that most small-cell base stations (SBSs) are deployed in an ad-hoc manner, the problem of reducing co-tier interference caused by dynamic loads in a distributed fashion is quite challenging. First, we propose a new distributed channel allocation method for small-cells with dynamic loads and define a dynamic interference graph. Based on this approach, we formulate the problem as a dynamic interference graph game and prove that the game is a potential game and has at least one pure strategy Nash equilibrium (NE) point. Moreover, we show that the best pure strategy NE point minimizes the expectation of the aggregate dynamic co-tier interference in the small-cell network. A distributed dynamic learning algorithm is then designed to achieve NE of the game, in which each SBS is unaware of the probability distributions of its own and other SBSs' dynamic loads. Simulation results show that the proposed approach can mitigate dynamic co-tier interference effectively and significantly outperform random channel selection.

• 교육녹색환경연구
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• 제3권1호
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• pp.35-45
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• 2003

This study purpose is the consideration of the processing evolution historic of the Educational Facilities 20s century at the grand view in the region Ile-de-France. Specially, by thepart of Educational Politic, Urban Geographic and the Urban Planning. This study purpose is to take a data base and study direction on 'A study of the role educational facility in the urban development'. So I was arrived these conclusions, First, the educational politic of the france was aimed for the democratization of the education and the popularization. After execution of the decentralization in the 1986, high school facilities was more popularized. Second, in the view point of the urban geographic, before 1975 years, high school facilities in the region ile-de-france was unbalanced in the situation regional and in the division social on the urban space. But after law of the Decentralization(1986) in the France, by effort of the regional conseil has take the regional balance. Third, high school facility has a potential force as a center of the development of the city. Forth, the facility has a possibility potential for a working of the important role in the urbanization. specially, the movement of population, the augment prix of the terrain, appartement and the division social in the urban space. as element that important relation with a development of the city.

• Corrosion Science and Technology
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• 제9권6호
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• pp.294-299
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• 2010

Two types of welding methods were performed on austenitic 304 stainless steel: laser welding and TIG welding. The differences of the corrosion characteristics of the welded zones from the two welding methods were investigated with electrochemical methods, such as measurement of the corrosion potential, polarization curves, cyclic voltammogram, etc. The vickers hardness of all laser-welded zones (WM:Weld Metal, HAZ:Heat Affected Zone, BM:Base Metal) was relatively higher while their corrosion current densities exhibited a comparatively lower value than those which were TIG welded. In particular, the corrosion current density of the TIG-welded HAZ had the highest value among all other welding zones, which suggests that chromium depletion due to the formation of chromium carbide occurs in the HAZ, which is in the sensitization temperature range, thus it can easily be corroded with an active anode. Intergrenular corrosion was also observed at the TIG-welded HAZ and WM zones. Consequently, we can see that corrosion resistance of all austenitic 304 stainless steel welding zones can be improved via the use of laser welding.

• Membrane and Water Treatment
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• 제7권1호
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• pp.39-53
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• 2016

In this study, polysufone (PSf) was used as a base polymer to synthesize sulfonated polysulfone (SPSf) and aminated polysulfone (APSf) as cation and anion exchange polymers, respectively. Then the ion exchange polymers were coated onto the surface of commercial carbon electrodes. To compare the capacitive deionization (CDI) and membrane capacitive deionization (MCDI) processes, the pristine carbon electrodes and ionic polymer coated electrodes were tested under various operating conditions such as feed flow rate, adsorption time at fixed desorption time, and feed concentration, etc., in terms of effluent concentration and salt removal efficiency. The MCDI was confirmed to be superior to the CDI process. The performance of MCDI was 2-3 times higher than that of CDI. In particular, the reverse desorption potential was a lot better than zero potential. Typically, the salt removal efficiency 100% for 100 mg/L NaCl was obtained for MCDI at feed flow rate of 15 ml/min and adsorption/desorption time of 3 min/1 min and applied voltages 1.0 V for adsorption and -0.3 V for desorption process, and for 500 mg/L, the salt removal efficiency 91% was observed.

• 기술혁신학회지
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• 제7권1호
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• pp.130-158
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• 2004

This paper aims at renewing the regional innovation system being embossed increasingly as a new paradigm to develop the regional area, using the innovational cluster based on the industrial properties and innovative base in Chungbuk province. As shown in the results of many researches, Chungbuk province is evaluated highly in regional innovation capability and is satisfied with the level of speciality in technical industry so that it has a potential capability to build the regional innovation system. However the clustering competition is growing in intensity between regional groups and there is a possible situation centralized by the high-tech industry into the metropolitan, so building the specialized innovation cluster requires advanced policy decisions and efforts in our won way. Ultimately, for the purpose of structuring the regional innovation system, the specialized innovation cluster reflected in regional industry and capability would be essential. It is time for Chungbuk province to prepare policies in order to make the Chungbuk-type innovation cluster which is neither uniform nor omnipresent.

• 한국농공학회논문집
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• 제52권6호
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• pp.27-37
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• 2010

The effect of potential future climate change on the storage rate of paddy field during storm periods (June - September) was assessed using the daily paddy water balance model. The CCCma CGCM2 data by SRES (special report on emissions scenarios) A2 and B2 scenarios of the IPCC (intergovernmental panel on climate change) was used to assess the future potential climate change. The future weather data for the year 2020s, 2050s and 2080s was downscaled by Change Factor method through bias-correction using 30 years weather data. The future (2020s, 2050s and 2080s) rainfall, storage and irrigation of paddy field, runoff in paddy levee and ponding depth were analyzed for the A2 and B2 climate change scenarios based on a base year (2005). The future irrigation change of paddy field was projected to increase by decrease in rainfall. So, runoff change in paddy levee was decrease slightly, future storage change of paddy was projected to increase.

• 대한조선학회지
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• 제24권2호
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• pp.29-35
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• 1987

As offshore activities move into deeper ocean, conventional fixed-base platforms drastically increase in size and cost, One of alternatives available is a guyed tower, in which environmental loads are supported by guylines instead of structural members. The guying system of the guyed tower is designed on one hand to be stiff enough to limit the structural displacement in normal operations, but on the other hand to be soft enough to permit large slow sways during the presence of design-level storms. This compliancy provides an efficient means of withstanding harsh environment so that the disproportionate increase in size of deep water platforms can be kept to a rational limit. Novel configurations contain always some degrees of potential risks mainly due to the lack of experience. The most critical hazard inherent to a guyed tower may be the pullout of anchor piles. Once it happens, the guyline fails to function and it may eventually lead to the total collapse of the system. It is the aim of this paper to discuss and quantify the anchor-pullout risk of a guyed tower. A stochastic analysis is made for evaluating the first-upcrossing probability of the tension acting on anchor piles over the uplift capacity. Nonlinearities involved in the mooring stiffness and hydrodynamics are taken into account by using time-domain analysis. A simplified two dimensional dynamic model is developed to exemplify the underlying concept. Real hurricane data in the Gulf of Mexico spanning over 70 years are incorporated in a numerical example of which result clearly indicates highly potential risk of anchor pullout.

• 대한원격탐사학회지
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• 제35권1호
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• pp.93-115
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• 2019

The availability of high-resolution laser scanning data and advanced machine learning algorithms has enabled an accurate potential rockfall source identification. However, the presence of other mass movements, such as landslides within the same region of interest, poses additional challenges to this task. Thus, this research presents a method based on an integration of Gaussian mixture model (GMM) and ensemble artificial neural network (bagging ANN [BANN]) for automatic detection of potential rockfall sources at Kinta Valley area, Malaysia. The GMM was utilised to determine slope angle thresholds of various geomorphological units. Different algorithms(ANN, support vector machine [SVM] and k nearest neighbour [kNN]) were individually tested with various ensemble models (bagging, voting and boosting). Grid search method was adopted to optimise the hyperparameters of the investigated base models. The proposed model achieves excellent results with success and prediction accuracies at 95% and 94%, respectively. In addition, this technique has achieved excellent accuracies (ROC = 95%) over other methods used. Moreover, the proposed model has achieved the optimal prediction accuracies (92%) on the basis of testing data, thereby indicating that the model can be generalised and replicated in different regions, and the proposed method can be applied to various landslide studies.

• Journal of Trauma and Injury
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• 제34권4호
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• pp.242-247
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• 2021

Purpose: Blunt cardiac injuries (BCI) have a wide clinical spectrum, ranging from asymptomatic myocardial contusion to cardiac rupture and death. BCIs rarely require surgical intervention, but can be rapidly fatal, requiring prompt evaluation and surgical treatment in some cases. The aim of this study was to identify potential factors associated with in-hospital mortality after surgery in patients with BCI. Methods: The medical records of 15 patients who had undergone emergency cardiac surgery for BCI between January 2014 and August 2020 were retrospectively reviewed. We included trauma patients older than 18 years admitted to Regional Trauma Center, Gachon University Gil Medical Center during the study period. Clinical and laboratory variables were compared between survivors and non-survivors. Results: Non-survivors showed a significantly higher Injury Severity Score (p=0.001) and Abbreviated Injury Scale in the chest region (p=0.001) than survivors. American Association for the Surgery of Trauma-Organ Injury Scale Grade V injuries were significantly more common in non-survivors than in survivors (p=0.031). Non-survivors had significantly more preoperative packed red blood cell (PRBC) transfusions (p=0.019) and were significantly more likely to experience preoperative cardiac arrest (p=0.001) than survivors. Initial pH (p=0.010), lactate (p=0.026), and base excess (BE; p=0.026) levels showed significant differences between the two groups. Conclusions: Initial pH, lactate, BE, ventricular injury, the amount of preoperative PRBC transfusions, and preoperative cardiac arrest were potential predictors of in-hospital mortality.

• 대한물리의학회지
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• 제18권3호
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• pp.11-19
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• 2023

PURPOSE: This study evaluated the incidence of sarcopenic obesity (SO) and examined the specific risk factors in a community-dwelling middle-aged population of women. METHODS: The present study involved analyzing data from a cross-sectional study that included 1,693 community-dwelling women aged between 40 and 49 years. Various risk factors were investigated, including age, height, weight, body mass index, waist circumference, skeletal muscle mass index, smoking and drinking behaviors, systolic and diastolic blood pressure, fasting glucose levels, as well as triglyceride and cholesterol levels. To ensure the accuracy and validity of the results, a complex sampling technique was employed for data analysis. Each sample weight was calculated through a three-step process by estimating base weight, adjusting it for non-response, and modulating it for post-stratification. RESULTS: The incidence of SO was 4.26% (95% CI: 3.20-5.67%). The clinical risk factors for SO were age, height, weight, body mass index, waist circumference, skeletal muscle mass index, systolic blood pressure, diastolic blood pressure, and levels of fasting glucose, triglycerides, and total cholesterol (p < .05). CONCLUSION: This study explores the prevalence and risk factors of SO among community-dwelling women. It adds to the existing literature on SO and identifies potential risk factors in middle-aged women.