• Proceedings of the KIEE Conference
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• 2008.09a
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• pp.140-143
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• 2008

In this study, it was studied about the improved road light design for drivers and pedestrians using ray- or reverse ray-tracing method. Many of conventional road lights are not suitable for drivers and pedestrians because it has some serious problems such as glare effect or randomicity of illuminated areas. It was oriented from customary design method which was pointed at simple target such as luminance or electrical power. But it was not truth any more that the high luminance or electrical power consumption mean more bright and good mad light. We studied ray-tracing method for road light reflector design to get the several goals. It means that good road light has easy for drivers and Pedestrians eyes and illuminating objects on the road clearly. So, we set the design targets such as uniformity on the road area per one road light, shading angles and continuous luminance uniformity on the long distance road. We designed ideal road light conditions using ray-tracing method. We set the height of drivers and pedestrians eyes and calculated design guideline to make above design targets. Then we designed road light reflector using reverse ray-tracing method. And we achieved same luminance on the road almost half power consumption because we reduced loss of light. We achieved ideal design guide as 75 degrees of shading angles and 0.5 of luminance uniformity on the road area. Finally, we suggested reflector design for 250 watts power consumption CDM light source.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.3
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• pp.347-350
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• 2009

In this study, it was studied about the improved road light design for drivers and pedestrians using forward or reverse ray-tracing method. Many of conventional road lights are not suitable for drivers and pedestrians because it has some serious problems such as glare effect or randomicity of illuminated areas. It was oriented from customary design method which was pointed at simple target such as luminance or electrical power. But it was not truth any more that the high luminance or electrical power consumption mean more bright and good road light. We studied ray-tracing method for road light reflector design to get the several goals. It means that good road light has easy for drivers and pedestrians eyes and illuminating objects on the road clearly. So, we set the design targets such as uniformity on the road area per one road light, shading angles and continuous luminance uniformity on the long distance road. We designed ideal road light conditions using ray-tracing method. We set the height of drivers and pedestrians eyes and calculated design guideline to make above design targets. Then we designed road light reflector using reverse ray-tracing method. And we achieved same luminance on the road almost half power consumption because we reduced loss of light. We achieved ideal design guide as 75 degrees of shading angles and 0.5 of luminance uniformity on the road area. It is superior than conventional road light ability such as 0.35 of luminance uniformity of 400 watts power consumption lamp. Finally, we suggested reflector design for 250 watts power consumption CDM Iight source.

• Korean Journal of Community Nutrition
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• v.7 no.3
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• pp.316-326
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• 2002

This study was carried out on 178 bus drivers in the Masan area to investigate their health and nutritional status. THe nutritional status of the subjects was surveyed using a self-administered questionnaire, and blood analyses were conducted through annual health examinations in June, 1999. The results were as fellows: About 51% were classified as normal, 33% as health-concerned, and 17% as disease-suspected. The levels of total seam cholesterol were significantly higher in the over 20 year group (194.64 $\pm$ 41.42 mg/dl) than in the under 10 year group (175,00 $\pm$ 31.33 mg/dl) with respect to the length of their driving careers. Systolic blood pressure (SBP) was significantly higher in the 51 to 60 age group than in the other groups (p < 0.05) . The total seam cholesterol increased with increasing age (p < 0.001), and SBP increased with increasing Body Mass Index (BMI) (p < 0.001). Diastolic blood pressure (DBP), total cholesterol (p < 0.01), hemoglobin (p < 0.05) and glutamate-pyruvate-aminotransferase (GPT) (p < 0.05) were significantly higher in the BMI of over 20, than in the BMI under 20. The GPT was significantly higher in the BMI over 25 than in the BMI under 25. In The mean daily energy intake was 1912.7 kcal (76.5% of the RDA) ultra the protein intake was 74.3 g (106.2% or the RDA). Compared with the recommended allowance, the energy, calcium, thiamin, and riboflavin intakes were below, and the Fe, vitamin A, vitamin C intakes were above the Korean RDA. The average carbohydrate, protein, fat ratio of energy intake was 66 : 15 : 19, respectively. The length of their driving careers had a positive correlation with their ages and total serum cholesterol levels, and their ages had a positive correlation with their blood pressures, total seam cholesterol and hemoglobin levels and BMI. Their BMI had a positive correlation with their ages, blood pressures, total serum cholesterol, hemoglobin, GPT and GOT levels. The results of this study indicate that bus drivers needed regular exercise, and control of their body weights to prevent chronic diseases, and that their health status should be monitored as the length of their driving careers and ages increase.

• Korean Journal of Adult Nursing
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• v.23 no.4
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• pp.321-331
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• 2011

Purpose: This study was designed to identify the incidence risk of cardicerebrovascular disease (CVD) among male bus drivers, and to examine and compare the predictors of their health behavior according to the level of CVD incidence risk. Methods: The convenience sample of 222 male bus drivers were recruited from a bus company located in Jeonnam province. Data were collected from self-reported questionnaires and annual medical examination records from 2010. The CVD incidence risk was calculated based on the risk criteria for industrial workers. Results: The 26.6% and 26.1% of the participants were in the moderate and high risk group, respectively. The 72% of the participants were in the precontemplation stage and reported no intention to change their unhealthy lifestyles. Stepwise multiple regression analyses showed that current smoking, excessive alcohol drinking, physical inactivity and lack of knowledge were negative predictors of good health behavior in the normal/low risk group (Adj $R^2$=.443). Heavy alcohol drinking, current smoking, physical inactivity and dyslipidemia were reported by the moderate/high risk group (Adj $R^2$=.427). Conclusion: This study suggested that targeted education and counseling are needed to modify unhealthy lifestyles such as alcohol consumption, smoking and exercise among middle aged male drivers. Especially, dyslipidemia should be managed among those who are at risk for CVD.

• Journal of Korean Society of Transportation
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• v.25 no.3
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• pp.99-109
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• 2007

Variable message signs (VMS), which are used for providing real-time information on traffic conditions and accident occurrences, are one of the important components of intelligent transportation systems VMS messages need to meet human factor requirements: messages should be readable and understandable while driving. Lab-controlled experiments on VMS messages were conducted to obtain useful data for analyzing drivers' responsive characteristics for VMS messages. Binary logistic regression (BLR) modeling techniques were applied to explore the relationships among drivers' message perceptions, message reading time, and amount of VMS messages. Probabilistic outcomes of the proposed BLR-based perception model could be greatly utilized to design VMS messages considering drivers' legibility performance. The major contribution of this study is to develop invaluable statistical models that can be used in designing VMS messages more effectively from the human factor point of view. The results could be further applied to establish the scheme of VMS message phase and duration.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.327-328
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• 2008

In this study, it was studied about the improved road light design for drivers and pedestrians using ray- or reverse ray-tracing method. Many of conventional road lights are not suitable for drivers and pedestrians because it has some serious problems such as glare effect or randomicity of illuminated areas. It was oriented from customary design method which was pointed at simple target such as luminance or electrical power. But it was not truth any more that the high luminance or electrical power consumption mean more bright and good road light. We studied ray-tracing method for road light reflector design to get the several goals. It means that good road light has easy for drivers and pedestrians eyes and illuminating objects on the road clearly. So, we set the design targets such as uniformity on the road area per one road light, shading angles and continuous luminance uniformity on the long distance road. We designed ideal road light conditions using ray-tracing method. We set the height of drivers and pedestrians eyes and calculated design guideline to make above design targets. Then we designed road light reflector using reverse ray-tracing method. And we achieved same luminance on the road almost half power consumption because we reduced loss of light. We achieved ideal design guide as 75 degrees of shading angles and 0.5 of luminance uniformity on the road area. Finally, we suggested reflector design for 250 watts power consumption CDM light source.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.32 no.1
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• pp.26-33
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• 2009

The directions of the road are divided into two, the right-hand side and left-hand side of the road, by the convention and specific native method in the world. This paper deals with the characteristics and behaviors of drivers who are accustomed to driving on right-hand side of the road, drive with a handle on the left-hand side, and comparing with left-hand side drivers. The driver's eye movements were measured by eye camera and questionnaires were used for measuring subjective evaluation such as driving mental workload. The experimental results indicated even if the experts who had much experience on right-hand side driving, they had lower driving skill than novice driver, accustomed to driving on left-hand side. In terms of mental workload, MCH rating scale and MNASA-TLX, the right-hand side drivers were in lower stress condition than the left-hand side drivers because of having much driving experience. However, they conducted a few mistakes by confusing the position of turn signal and windshield wiper because of their driving habit or traits and it lead to operation mistakes. These results can be applied effectively to develop the driving support information with changed environments.

• Journal of Korean Society of Transportation
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• v.29 no.2
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• pp.71-80
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• 2011

Almost all Drivers who are not familiar with local areas usually rely on road signs equipped along the roadways. The road signs in Korea present the name of the city along the driver’s direction. The consistency of guided name on the road-signs is important for drivers. The discordances among road signs frustrate drivers particularly when the drivers are confused with whether or not they are in the right direction. There are several studies focusing on the continuity of information on the road signs. Most of the researches, however, do not suggest the objective way but diagnose present problem. Applying the Analytic Hierarchy Process (AHP), we evaluate the impact of information on road signs and select the candidate information considering the score and limited number of information. We also suggest the reasonable spatial influence area of road sign information using geo-spatial analysis. From this study, we expect that the director in charge of selecting information can make decision reasonably without difficulties of choosing information.

• Korean Journal of Adult Nursing
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• v.28 no.2
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• pp.180-190
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• 2016

Purpose: This study examined the influence of occupational type and lifestyle habits on the prevalence of metabolic syndrome (MetS) among Korean male workers. Methods: Through secondary analysis of their four-year health examination data, 3,892 subjects were divided into four subgroups according to the presence of MetS now and four years ago. Results: Nineteen percent (n=739) suffered from MetS and these 739 subjects were classified into following occupations: 7.1% were office workers, 17.6% were non-office workers, and 42.2% were drivers. Multiple logistic regression analyses showed that when the data adjusted for age, the predicting factors on the prevalence of MetS were heavy drinking (OR 1.34, 95% CI 1.09~1.64) and the occupation of non-office workers (OR 2.99, 95% CI 2.13~4.18) and drivers (OR 7.97, 95% CI 4.89~10.83) among workers without MetS four years ago. Among workers already with a history of MetS, the predicting factors were less exercise (OR 1.55, 95% CI 1.02~2.35) and drivers (OR 2.21, 95% CI 1.03~2.94). Conclusion: Heavy drinking and less exercise and drivers were reported as influencing factors on the prevalence of MetS by this sample. The findings suggest that employers need to provide their employees with screening and management program for those at risk of MetS.

• The Journal of the Korea Contents Association
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• v.11 no.10
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• pp.457-466
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• 2011

In general, drivers need a self-interest information to decide their routes. So, non-governmental sectors, such as Internet Portal Company, make and provide user-oriented contents for drivers in a hurry. But, VMS which is the typical public media always provides traffic-information for drivers without weighting personal characteristics and considering transportation conditions. So in this research, we searched importance and preference of traffic-information contents as IPA(Importance-Performance Analysis)result. We can draw the conclusion that the improvement of traffic-information contents focused on users(drivers) is needed. Specially, we proposed the strategy of VMS according to traffic conditions.