• Health Policy and Management
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• v.30 no.2
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• pp.199-210
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• 2020

Background: Based on the importance of ceasing smoking programs to control the regional disparity of smoking behavior in Korea, this study aims to reveal the variation of smoke rate and determinants of it for 229 provinces. An evaluation of the relative efficiency of the cease smoking program under the consideration of regional characteristics was followed. Methods: The main sources of data are the Korean Statistical Information Service and a national survey on the expenditure of public health centers. Multivariate regression is performed to figure the determinants of regional variation of smoking rate. Based on the result of the regression model, clustering analysis was conducted to group 229 regions by their characteristics. Three clusters were generated. Using data envelopment analysis (DEA), relative efficiency scores are calculated. Results from the pooled model which put 229 provinces in one model to score relative efficiency were compared with the cluster-separated model of each cluster. Results: First, the maximum variation of the smoking rate was 16.9%p. Second, sex ration, the proportion of the elder, and high risk drinking alcohol behavior have a significant role in the regional variation of smoking. Third, the population and proportion of the elder are the main variables for clustering. Fourth, dissimilarity on the results of relative efficiency was found between the pooled model and cluster-separated model, especially for cluster 2. Conclusion: This study figured regional variation of smoking rate and its determinants on the regional level. Unconformity of the DEA results between different models implies the issues on regional features when the regional evaluation performed especially on the programs of public health centers.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.5
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• pp.162-170
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• 2004

In these days, a vehicle simulator is developed by using a VR(Virtual Reality) system. A VR system must provide a vehicle simulator with a natural interaction, a sufficient immersion and realistic images. To achieve this, it is important to provide a fast and uniform rendering performance regardless of the complexity of virtual worlds or the level of simulation. In this paper, modeling methods which offer an improved rendering performance for complex VR applications as 3D road model have been implemented and verified. The key idea of the methods is to reduce a load of VR system by means of LOD(Level of Detail), alpha blending texture mapping, texture mip-mapping and bilboard. Hence, in 3D road model where a simulation is complex or a scene is very large, the methods can provide uniform and acceptable frame rates. The VR system which is constructed with the methods has been experimented under the various application environments. It is confirmed that the proposed methods are effective and adequate to the VR system which associates with a vehicle simulator.

• Journal of Technologic Dentistry
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• v.40 no.2
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• pp.63-69
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• 2018

Purpose: The purpose of this study is to investigate the non-precious metal core materials used in the dental laboratory to fabricate the implant superstructure by CAD / CAM method. And to observe and compare the morphology and distribution of the osteoblasts in relation to implant osseointegration. Methods: In this study, the mandibular right first molar tooth model was selected as an international standard to produce a single core. Using this model, the impression was made with the silicone rubber, the tooth model was scanned, and a single core was designed and 5-axis milling was performed. The materials used were Cobalt-Chromium and Nickel-Chromium, and the cores for dental implant top structures were fabricated according to the procedures of the dental labs. After the fabrication, the marginal area of the core was separated and cell culture experiment was performed. The osteoblast cells used MC3T3-E1, which is currently widely used. For morphological analysis of osteoblasts, cells were posttreated and observed using CLSM (Confocal Laser Scanning Microscope) and compared. Results: The cell adhesion behavior of the specimen surface measured by CLSM was uniformly distributed in specimen A (Cobalt-Chromium) than in specimen B (Nickel-Chromium). The distribution and changes of the cells were different in the two specimens. Conclusion : It is possible to confirm that specimen A (Cobalt-Chromium) is suitable for the living body through adhesion and proliferation of osteoblasts related to implant osseointegration in the non-precious metal superstructure used after implantation. It is considered that it is preferable to use Co-Cr when fabricating the superstructure.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.10
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• pp.857-864
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• 2016

In this study, we proposed a novel concept of electric sun visor comprising a dark, see-through sun shade material that ensures unimpaired driver's vision with continuous control of the shade position. The shade extending from the windshield base along its surface may be subjected to severe vibration during driving unless the design parameters are carefully selected. A prototype was tested to collect acceleration data during driving. Based on the test data, an ADAMS dynamics model was validated. The mechanism of sun visor was optimized to minimize vibration based on the dynamics model, experimental design, and response surface method.

• Journal of the Korean Society for Precision Engineering
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• v.34 no.4
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• pp.253-258
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• 2017

This paper presents a numerical study on the thermal characteristics of a milling process of titanium alloy with nanofluid minimum-quantity lubrication (MQL). The computational fluid dynamics (CFD) approach is introduced for establishing the numerical model for the nanofluid MQL milling process, and estimated temperatures for pure MQL and for nanofluid MQL using both hexagonal boron nitride (hBN) and nanodiamond particles are compared with the temperatures measured by thermocouples in the titanium alloy workpiece. The estimated workpiece temperatures are similar to experimental ones, and the model is validated.

• Journal of Korea Multimedia Society
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• v.24 no.2
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• pp.186-198
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• 2021

Security control using surveillance cameras is established when people observe all surveillance videos directly. However, this task is labor-intensive and it is difficult to detect all abnormal situations. In this paper, we propose a deep neural network model, called AT-Net, that automatically detects abnormal situations in the surveillance video, and introduces an automatic video surveillance system developed based on this network model. In particular, AT-Net alleviates the ambiguity of existing abnormal situation detection methods by mapping features representing relationships between people and objects in surveillance video to the new tensor structure based on sparse coding. Through experiments on actual surveillance videos, AT-Net achieved an F1-score of about 89%, and improved abnormal situation detection performance by more than 25% compared to existing methods.

• Journal of Korean Society of Rural Planning
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• v.9 no.2 s.19
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• pp.29-37
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• 2003

The objectives of this study are to develop an agricultural drought evaluation model based on administrative boundaries and to assist the effective drought-related decision-making of local governments. The model which was named ADEM(Administrative Drought Evaluation Model for Paddies) is designed to simulate daily water balance between available water quantities from various agricultural water facilities such as reservoirs, wells, pump stations, etc. and water requirements in paddies. And in order to numerically describe the agricultural drought severity, two indices were defined; One is ADFP(Agricultural Drought Frequency for Paddies) which is calculated with a frequency analysis of monthly water deficit, and the other is ADIP(Agricultural Drought Index for Paddies) with a scale of $-4.2{\sim}+4.2$. The developed model was applied to Yeoju district and showed good correspondence with the historical records of drought.

• The KSFM Journal of Fluid Machinery
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• v.18 no.4
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• pp.49-55
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• 2015

The pumped storage plant operates with quick change of the discharge as well as quick changes between pump mode and turbine mode. This study focuses on the cavitation analysis of a pump-turbine model because in turbo-machinery, cavitation can reduce the performance and shorten service life. The pump-turbine model system consists of 7 blades, 20 stay vanes (including tongue) and 20 guide vanes. This study adopts the Rayleigh-Plesset model as a cavitation model, which illustrates cavitation by using the air volume fraction method. The pump mode and turbine mode at the operating condition of partial loading, normal and excessive loading are analyzed to investigate the cavitation performance of the pump-turbine. It was observed that this pump-turbine design showed very good cavitation characteristics with no cavitation bubbles in all operating conditions. Overall value of air volume fraction of both mode at different operating condition are lower than 1, which confirms low possibility of cavitation occurrence at current situation.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.606-611
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• 2009

This paper describes a method for achieving a novel design within a class of 3D objects that would create a preferred impression on users. Physical parameters of the 3D objects that might strongly contribute to their visual impressions are sought through computational investigation of the impression ratings obtained for learning samples. "Car body" was selected as the class of 3D objects to be investigated. A morphable 3D model of car bodies that describes the variations in appearance using a smaller number of parameters was obtained. Based on each car body's rating for the impression of speediness obtained by paired comparison, the visual impression was transformed by manipulating the parameters defined in the morphable 3D model. The validity of the proposed method was confirmed by psychological experiments. A new scheme is also proposed to properly re-sample a novel object of a peculiar shape so that such an object could also be represented by the morphable 3D model.

• Journal of the Korea Society of Computer and Information
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• v.24 no.4
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• pp.35-43
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• 2019

The purposes of this study is to derive the influence factors of Virtual Reality(VR) technologies acceptance based on the study of unified theory of acceptance and use of technology and value-based acceptance model to test the use and acceptance of VR devices. The survey methods were used for this study, and the data from a total of 400 consumers were used for the analysis. And the structural equation model was used to analyze the data. The results of the study are as follows: First, benefit components perceived enjoyment(EN) and sacrifice components personal innovative(PI) of VR devices were positively related to perceived values and use intention of VR devices, although the benefit components performance expectancy(PE) was positively related to perceived values(PV) but was not positively related to the use intention of VR devices. Second, sacrifice components perceived cost(PC) and anxiety(ANX) of VR devices were negatively related to perceived value(PV), but were not negatively related to the use intention of VR devices. Third, perceived values was not obvious related to the use intention(UI) of VR devices. The results of this study contribute to the literature as a new attempt to examining the effect on consumer use intention in VR technology areas.