• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.521-524
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• 2001

In this letter. we report on the investigation of Ti. Pt/Si/Ti Ohmic contacts to p-type 4H-SiC. The contacts were formed by a 2-step vacuum annealing at $500^{\circ}C$ for 1h. $950^{\circ}C$ for 10 min respectively. The contact resistances were measured using the transmission line model method. which resulted in specific contact resistivities in the $3.5{\times}10^{-3}$ and $6.2{\times}10^{-4}ohm/cm^{2}$, and the physical properties of the contacts were examined using x-ray diffraction. microscopy. AES(auger electron spectroscopy). AES analysis has shown that, at this anneal temperature, there was a intermixing of the Ti and Si. migration of into SiC. Overlayer of Pt had the effect of decreasing the specific contact resistivity and improving the surface morphology of the annealed contact.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.17 no.3
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• pp.197-207
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• 2013

The Cahn-Hilliard equation was proposed as a phenomenological model for describing the process of phase separation of a binary alloy. The equation has been applied to many physical applications such as amorphological instability caused by elastic non-equilibrium, image inpainting, two- and three-phase fluid flow, phase separation, flow visualization and the formation of the quantum dots. To solve the Cahn-Hillard equation, many numerical methods have been proposed such as the explicit Euler's, the implicit Euler's, the Crank-Nicolson, the semi-implicit Euler's, the linearly stabilized splitting and the non-linearly stabilized splitting schemes. In this paper, we investigate each scheme in finite-difference schemes by comparing their performances, especially stability and efficiency. Except the explicit Euler's method, we use the fast solver which is called a multigrid method. Our numerical investigation shows that the linearly stabilized stabilized splitting scheme is not unconditionally gradient stable in time unlike the known result. And the Crank-Nicolson scheme is accurate but unstable in time, whereas the non-linearly stabilized splitting scheme has advantage over other schemes on the time step restriction.

• International Journal of Naval Architecture and Ocean Engineering
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• v.5 no.2
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• pp.277-286
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• 2013

Cross-shore sediment transport is very important factor in the design of coastal structures, and the beach profile is mainly affected by a number of parameters, such as wave height and period, beach slope, and the material properties of the bed. In this study cross-shore sediment movement was investigated using a physical model and various offshore bar geometric parameters were determined by the resultant erosion profile. The experiments on cross- shore sediment transport carried out in a laboratory wave channel for initial base slopes of 1/8, 1/10 and 1/15. Using the regular waves with different deep-water wave steepness generated by a pedal-type wave generator, the geometrical of sediment transport rate and considerable characteristics of beach profiles under storm conditions and bar parameters affecting on-off shore sediment transport are investigated for the beach materials with the medium diameter of $d_{50}$=0.25, 0.32, 0.45, 0.62 and 0.80 mm. Non-dimensional equations were obtained by using linear and non-linear regression methods through the experimental data and were compared with previously developed equations in the literature. The results have shown that the experimental data fitted well to the proposed equations with respect to the previously developed equations.

• Journal of the Korean housing association
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• v.18 no.6
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• pp.35-44
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• 2007

The purpose of this paper is to find out the factors affecting the apartment price given three sets of variables such as characteristics of apartment building, apartment site, and location. Data of 1,579 housing units in 224 apartment complex sites in Ilsan city were selected from the housing information of four public and private housing sources in 2006. The first set of variables for physical features include housing size (pyoung), preferring-floor, building orientation, heating system and structure of entrance. The second set of variables for building were number of housing units, built year and rank of construction company. The third set of variables for location were distance from number of school, the subway station, distance of department store and park. For the analysis, the hedonic price model, which was one of the methods to estimate social convenience, was used along with the SPSS statistical program and regression analysis. The results are as follows, Firstly, in the structural characteristic variables, it was analyzed that all of the variables except facing affected the apartment price. Secondly, In the site characteristic variables, unusually all of the variables were not affected the apartment price in Ilsan city. Finally, the locational characteristic variables number of school, the subway station, distance of department store and park affected the apartment price. In case of Ilsan city, educational facilities was likely to positively contribute to the price of apartment.

• Industrial Engineering and Management Systems
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• v.15 no.4
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• pp.290-297
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• 2016

The successful transfer of technology, needs to recognize the industrial purposes, resources, technology, innovation and the mode of transmission, methods of transmission, influential factors, it's how to recruit and how to develop, and each of these cognitive relies on special expertise. One of the important technologies is automotive technology, and s technology is important for the transition and its development in recent years. Hence, in this paper, after studying Iran and the world's automotive and emerging technologies situation, the status of commercial vehicles and s technology model are studied based on external models, technical specifications, and cost. In this way, we examine the incidence and the applicability of the technology used in the production of heavy-duty vehicles, in recent years, with the passage of time, and we examine the technology lifecycle, from the perspective of physical characteristics and technical features. The results show that the technology of the studied heavy-duty vehicles (Titan) is close to the time of his fall, because spending puberty, so, according to the investigation of new technologies, we should strive to create changes in vehicle technology.

• Journal of Korean Clinical Nursing Research
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• v.23 no.2
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• pp.202-210
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• 2017

Purpose: In this study an investigation was done of injuries from inpatient falls and diagnostic tests and treatment after falls to identify what factors affect the occurrence of injury from inpatient falls in a tertiary hospital. Methods: Data for this cross-sectional study were retrieved for 428 fall events from data reported between January 1 and December 31, 2015 and were retrieved from the patient-safety reporting system in the hospital's electronic health records. A multivariate logistic regression model was developed with STATA 13.0. Results: Of the patients, 197 (46.0%) had physical injuries due to falls, 119 (27.8%) were given further diagnostic tests, and 358 (83.6%) received treatment including close observation after inpatient falls. Logistic-regression results identified that age, department, and risk factors had significant impact on injuries from falls. Conclusion: Findings indicate that to reduce the severity of injury after inpatient falls, each hospital should regularly evaluate identified factors, design fall-prevention practices specialized for elders and vulnerable patients, and initiate environmental and equipment innovations.

• KIEAE Journal
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• v.9 no.1
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• pp.31-38
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• 2009

The purpose of this study is to present direction in outdoors space planning and design after direction through user characteristic analysis through spectacle component establishment of culture art center outdoors space through on-the-site analysis and literature investigation to culture art center of Seoul city and capital region 17 places in this research. The data was collected from classification and bisection kind, subdivision kind, and great classification composed to 17 items. User satisfaction side and Variable that is looked below satisfaction than average appeared to bench, pergola, sculpture facilities, pavement facilities, border facilities. And these facilities were analyzed dissatisfaction. When see satisfaction model, when make up culture art center or similar facilities in local government hereafter because parking facilities and rest area cause big effect in satisfaction, is judged that is item to consider most preferentially. In most case, parking lot security from outdoors space, resting place security, security of field performance facilities etc. taking a serious view because tendency that users see performance or use most vehicles except neighborhood walking area for a rest, a walk etc.. is trend. But, is judged that physical side so that can feel satisfaction as space security of quantitative side is important but users utilize substantially and side that is the program are more important in hereafter.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.521-524
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• 2001

In this letter, we report on the investigation of Ti, Pt/Si/Ti Ohmic contacts to p-type 4H-SiC. The contacts were formed by a 2-step vacuum annealing at 500$^{\circ}C$ for 1h, 950$^{\circ}C$ for 10 min respectively. The contact resistances were measured using the transmission line model method, which resulted in specific contact resistivities in the 3.5x10$\^$-3/ and 6.2x10$\^$-4/ ohm/$\textrm{cm}^2$, and the physical properties of the contacts were examined using x-ray diffraction, microscopy, AES(auger electron spectroscopy). AES analysis has shown that, at this anneal temperature, there was a intermixing of the Ti and Si, migration of into SiC. Overlayer of Pt had the effect of decreasing the specific contact resistivity and improving the surface morphology of the annealed contact.

• Korean Institute of Interior Design Journal
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• v.15 no.1 s.54
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• pp.121-130
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• 2006

The key role of performance facilities is to provide the stage shape and stage system suitable for the purpose and the property of public performance. The purpose of this study is to draw comparison analysis about the stage construction and stage machine system of the specialty theater or the multiple purpose performance facilities. The progress of the research is as followings. 1. Investigation into literature and catching on physical composition in the performing facilities, 2. Analysis of the stage organization, items of performance, construction form of stage machine systems, conversion system of the analysis samples, 3. A suggestion of the standard model of stage by each scales, through the such continuous analysis. And it was founded that the relation of stage composition, production type, stage system and distribution, and also the basic data between each elements. On the basis of the results, this study proposes the data and the application methods in domestic performance space when we are setting up the plan of performance facilities.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.11
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• pp.937-944
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• 2015

Recently, the change of mechanical properties and microstructural evolution during severe plastic deformation (SPD), such as Equal Channel Angular Extrusion (ECAE), has been the subject of intensive investigation because of the unique physical and mechanical properties of severely deformed materials. In this study, two types of ECAE processes were considered, dies with intersection angles ${\Phi}$ of $90^{\circ}$ and $120^{\circ}$, using experiments and simulations. The decoupled method, in which the rigid-plastic finite element method is incorporated with the rate-independent crystal plasticity model, was applied to predict the texture evolution in commercially pure aluminum during the ECAE processes with $120^{\circ}$ and $90^{\circ}$ dies. The simulated textures were compared with a measured texture via an EBSD OIM analysis. The comparison showed that the simulated textures generally were in good agreement with the experimentally measured texture.