• Journal of agricultural medicine and community health
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• v.49 no.1
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• pp.50-58
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• 2024

Objective: The purpose of this study is to examine the factors influencing the health status of first-year high school students leisure activity time, considering of the city size. Methods: This study utilized the first cohort survey of the Korean Children and Youth Panel Survey. The analysis was used data from survey targeting first-year high school students of 2021. The city size was divided into large cities and medium and small-sized cities, and T-test was conducted to examine differences in factors by city size, and multiple regression analysis was conducted to identify factors influencing health status according to leisure activity time on weekdays and weekends by city size. Results: In large cities, exercise and physical activity time and other than that, Time to play with friends had a positive effect(+), Time to play with a smartphone had a negative effect(-) on both weekdays and weekends. In medium and small-sized cities, Exercise and physical activity time and Time to play while watching TV had a positive influence(+) on both weekdays and weekends, while Time to play with a smartphone had a negative influence(-). Conclusion: There were the same questions for factors influencing health status, but other questions also appeared. Leisure activities that have a positive(+) impact on health status by city size are supported so that leisure activities can be actively carried out, while leisure activities that have a negative(-) impact are participate in other leisure activities together to improve health. It is believed that this plan should be considered.

• Journal of the Korean Professional Engineers Association
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• v.37 no.5
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• pp.47-50
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• 2004

Diesel engines are the major sources of pollutants in the cities and each country is trying to enforce their emission regulations to reduce the diesel emissions. Expecially Commercial diesel engines have large displacement and they are the major sources of diesel emissions in the cities. This paper introduces the major countries' Diesel Engine Regulations and explains the emission reduction technologies that are currently applied and will be applied in the future.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.390-400
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• 2011

Light rail are being constructed in cities have populations of mare than 700 thousand in the country as well as many cities in the world as an environmental and a low caron public transit. This paper reviews the capacity selections of electric power system about Light rail transit according to rail, vehicles, operation conditions.

• Proceedings of the Acoustical Society of Korea Conference
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• 1998.06c
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• pp.343-346
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• 1998

This paper present an access scenario to the Korean standard time service systems and those of world major cities was designed in the research for development of the time-announcing service systems. Elements of the system structure as well as statistics and user management were proposed as the main topics for the research. As a result of the research, a system was realized for world time announcing service by dialing 116.

• Journal of Korean Library and Information Science Society
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• v.30 no.4
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• pp.207-228
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• 1999

This study is to evaluate the economies of scale of the public libraries in metropolitan cities. The results of the regression analysis confirm that for all samples of libraries there is diseconomies of scale in library operations (${\Sigma}b_{n}$≒6.14∼10.91). Therefore, all the types of public libraries should be improve productivity by user-based collection development, increasing circulation turnover rate, activation of in-library use, strengthening mobile library services, rational planning of services area, development of reading programs connected with the curriculum, a new branch library plans, etc.

• KIEE International Transactions on Power Engineering
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• v.4A no.1
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• pp.6-10
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• 2004

This paper presents an assessment of the customer interruption costs using a macro economic methodology of Korean customers by cities and provinces. The customer interruption cost is considered a very useful index in quantifying reliability worth from a customer point of view. This paper reviews the methodology to evaluate the customer interruption costs and ratio to the average revenues per electric energy sold for public, service agriculture, fishery, mining, manufacturing and residential sectors by cities and provinces in Korea.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2009.04a
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• pp.275-276
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• 2009

공간 변화의 동적과정을 시뮬레이션 하기 위한 이론과 모델들은 대, 중, 소규모에 따라 system of cities, city system, cities 로 나눌 수 있으며, 지난 40년 동안 이 각각의 규모에 초점을 맞춘 연구들이 진행되어 왔다. 하지만, 각 규모를 통합하여 도시를 설명하는 이론은 없는 상황이다. 이에 본 연구는 거듭제곱 법칙을 기반으로 한 행위자기반모형을 이용하여 모든 규모에서 설명이 가능한 모형을 제시하고, 이러한 거듭제곱 법칙이 공간패턴 형성에 어떠한 영향을 미치는지 분석하였다.

• Journal of East-Asian Urban History
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• v.1
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• pp.81-96
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• 2019

This paper attempts to rethink the ancient Emperor's Capital transition process from the viewpoint of territorial history. Emperor Tenmu, who planned first capital as Fujiwara-kyo in Asuka region, had a grand plan to put multiple cities in Japan. At that time the important cities were situated along east-west axis. However, since relocation of the capital from Fujiwara-kyo to Heijyo-kyo, the axis had turned towards north-south direction. The last ancient capital Heian-kyo was clearly organized utilizing north-south water systems in territorial sense.

• Electronics and Telecommunications Trends
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• v.33 no.2
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• pp.86-90
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• 2018

ISO, IEC, ISO/IEC JTC 1 and ITU-T have been preparing for smart city standardization since 2013, and as a result of related activities, four international standardization groups, namely, ITU-T SG20, IEC Systems Committee on Smart Cities, ISO TC268, and ISO/IEC JTC 1/WG 11, have been established, and the development of related international standards is progressing. In this paper, the status of the standardization activities of ITU-T SG20, the IEC Systems Committee on Smart Cities, ISO TC268, and ISO/IEC JTC 1/WG 11 are reviewed.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.500-509
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• 2005

Light-rail transit system has many characteristics of better accessibility. frequency service, low construction cost, reduced air pollution and medium-capacity public transport etc. Light rail transit system as a urban transportation system has been growing worldwide since the late 20th century. More than 300 cities around the world have light railway systems. Many medium-size cities in domestic site is planning the construction of light railway. This paper describes the development strategies for the light rail transit industry.