• Title/Summary/Keyword: cities

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Optimal Solution of a Large-scale Travelling Salesman Problem applying DNN and k-opt (DNN과 k-opt를 적용한 대규모 외판원 문제의 최적 해법)

  • Lee, Sang-Un
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.15 no.4
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    • pp.249-257
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    • 2015
  • This paper introduces a heuristic algorithm to NP-hard travelling salesman problem. The proposed algorithm, in its bid to determine initial path, applies SW-DNN, DW-DNN, and DC-DNN, which are modified forms of the prevalent Double-sided Nearest Neighbor Search and searches the minimum value. As a part of its optimization process on the initial solution, it employs 2, 2.5, 3-opt of a local search k-opt on candidate delete edges and 4-opt on undeleted ones among them. When tested on TSP-1 of 26 European cities and TSP-2 of 49 U.S. cities, the proposed algorithm has successfully obtained optimal results in both, disproving the prevalent disbelief in the attainability of the optimal solution and making itself available as a general algorithm for the travelling salesman problem.

An Impact of Gas Prices on Transit Demand Using a Time-series Analysis and a Regression Analysis (시계열 및 회귀분석을 활용한 휘발유가격의 광역권별·수단별 대중교통수요 영향력 비교분석)

  • Lee, Kwang Sub;Eom, Jin Ki;Moon, Dae Seop;Yang, Keun Yul;Lee, Jun
    • Journal of Korean Society of Transportation
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    • v.32 no.1
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    • pp.13-26
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    • 2014
  • Depending most of its energy sources on foreign countries, Korea efforts to reduce energy consumption in transportation. While studies on the relationship between gas price and transportation demand are many in number, most previous studies have focused on automobile and Seoul. This study analyzes the impact of gas price on transit (bus and subway) demand using monthly data and for various metropolitan areas (Seoul, Busan, Daejeon, Daegu and Gwangju). The research utilizes a time-series model and a multiple regression model, and calculates modal demand elasticities of gas price. The result shows that elasticities of subway demand with respect to gas price is higher than those of bus demand. In addition, elasticities of predominantly automobile cities are more likely to be more sensitive to gas price than those of cities with well-structured transit system.

Institutional Arrangement and Policy Context Underlying Sustainability Actions in the U.S.: Lessons for Asian Regions

  • Hwang, Joungyoon;Song, Minsun;Cho, Seong
    • Journal of Contemporary Eastern Asia
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    • v.19 no.1
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    • pp.59-83
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    • 2020
  • This paper examines the actions and the factors driving those actions to reduce energy consumption and enhance energy efficiency taken by United States cities. While not much empirical evidence is available on why governments pursue practical sustainability actions, we attempt to shed more light on this important topic by empirically identifying factors that contribute to concrete actions toward sustainability policies. We adopt political market theory as a basic theoretical framework with policy-making applied to city energy consumption. Using the 2010 ICMA (local government sustainability policies and program) data, this study expands the focus of analyses to evaluate the effect of the form of government on energy consumption and energy efficiency by using multiple regression analysis. The findings show that at the city level, the mayor-council form of government are negatively associated with governments' efforts to reduce energy consumption. However, cities with at-large elections and municipal ownership are more likely to adopt sustainability actions. We also find that a large-scale economy has significant effects on the effort to reduce city energy consumption and improve energy efficiency. This shows that environmental policies are directly connected to locally relevant affairs, including housing, energy use, green transportation, and water. Thus, local level administrators could take an executive role to protect the environment, encourage the development of alternative energy, and reduce the use of fossil fuel and coal energy. These efforts can lead to important environmental ramifications and relevant actions by municipal governments.

Distribution Characteristics of Volatile Organic Compounds (VOCs) in an Industrial Complex and in Affected Areas in Siheung and Ansan (시흥·안산 산단 및 영향지역의 휘발성유기화합물질(VOCs) 분포 특성)

  • Kim, Dong-Gi;Woo, Jung-Sik;Han, Hyun-Su;Kim, Yong-Jun;Kim, Woong-Soo;Hong, Soon-Mo;Kim, Jong-Soo;Yoon, Mi-Hye
    • Journal of Environmental Health Sciences
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    • v.46 no.3
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    • pp.256-266
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    • 2020
  • Objectives: The concentrations and distribution characteristics of volatile organic compounds (VOCs) in an industrial complex and surrouding affected residential areas were investigated in an effort to support the efficient management of VOCs. Methods: The atmospheric concentrations of VOCs were analyzed at sites around the Sihwa-Banwol complex located in the cities of Siheung and Ansan and in the surrounding affected residential areas. The appearance of VOCs and the characteristics of their temporal and spatial distribution were evaluated. Results: The total VOC concentrations in the industrial complex were detected at 1.9-2.3 times higher than in the affected areas, but the daily VOCs distributions showed similar patterns in both sites. In particular, it was confirmed that the composition ratio of the VOCs and concentration fluctuations over time in the affected areas are similar to those in the adjacent industrial complex. VOC levels in the affected areas were higher than in residential areas in cities without an industrial complex. Conclusions: VOCs in residential areas near an industrial complex were highly distributed due to the influence of continuous pollutant emissions from the industrial complex. Therefore, the management of VOCs in the atmosphere of the affected area is important for identifying and managing the sources of VOCs detected in high concentrations in the industrial complex.

A Study on Characteristics of Rural Planning in North Korea - Focused on the Urban-Rural Integration Strategy in Kim Il-Sung Era - (북한의 농촌 공간계획의 특징에 관한 연구 - 김일성 시기 도농연계이론을 바탕으로 -)

  • Kim, Mina
    • Journal of the Korean Institute of Rural Architecture
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    • v.21 no.4
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    • pp.9-16
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    • 2019
  • This study aims to identify the rural spatial structure and to establish the planning characteristics based on urban-rural connections strategy of North Korea. For this purpose, they were collected such as documents and drawings including primary data related to rural planning in North Korea, and the rural space were classified into three elements in order to analyze them by the rural planning's point of the view. Unlike generalized capitalist cities, socialist North Korean cities are characterized by the coexistence of urban and rural areas. This distinct feature of the city is also reflected in creating rural space in North Korea. Thus, The urban-rural integration in spatial planning is a key factor in understanding the spatial structure of North Korea. This study firstly examines the characteristics of the county(gun), the administrative and economic unit established in the post-war period, secondly, examines the planning method of town(eup) which can be called the urban center in rural areas, and lastly grasps the planning method of rural village focusing on collectivization and identifies how they are connected to the town for the shake of urban-rural integration. As a result, the characteristics of rural planning in North Korea has revealed that it has a comprehensive rural planning established with the goal of strengthening the self-sufficiency of the rural area by the means of the create of rural spatial hierarchy in the whole country.

Severity of Atopic Dermatitis and Associated Factors in Korean Adolescents by Sex (성별에 따른 한국 청소년의 아토피 피부염 심각성과 영향요인)

  • Yi, Yunjeong;Hyun, Sook Jung;Lee, Jinhwa;An, Ji Yeon
    • Journal of the Korean Society of School Health
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    • v.30 no.2
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    • pp.164-173
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    • 2017
  • Purpose: Despite the high incidence, the incidence of atopic dermatitis among adolescents has been continuously increasing. The study was conducted to examine the severity of atopic dermatitis among middle school students and to identify the factors affecting the severity. Methods: The data used in the analysis are from 2015 Youth Health Behavior Online Survey. Complex sample analysis was conducted to analyze the severity of atopic dermatitis which was defined by the treatment experience of atopic dermatitis and the number of absent days due to the disease as its criteria. Binary logistic regression of the factors affecting the severity of atopic dermatitis by gender was done. Results: The severity of atopic dermatitis was high in male students who were in a lower grade (freshmen), who smoked, or who consumed soft drinks at least once a week, while in female students who were in a lower grade (freshmen, sophomore), who consumed alcohol, who consumed highly caffeinated drinks at least once a week or who consumed sweet drinks at least once a week. The severity of atopic dermatitis was lower in female students who lived in big cities or medium/small sized cities or engaged in physical activities less than three times a week. Conclusion: For atopic dermatitis among middle school students, the importance of dietary management should be considered. This indicates that families, schools, and communities have their own responsibilities and efforts to relieve the symptoms of the atopic dermatitis.

Development and Assessment of Environmental Water Seasonal Outlook Method for the Urban Area (도시지역에 대한 환경용수의 계절전망 기법 개발 및 평가)

  • So, Jae-Min;Kim, Jeong-Bae;Bae, Deg-Hyo
    • Journal of Korean Society on Water Environment
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    • v.34 no.1
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    • pp.67-76
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    • 2018
  • There are 34 mega-cities with a population of more than 10 million in the world. One of the highly populated cities in the world is Seoul in South Korea. Seoul receives $1,140million\;m^3/year$ for domestic water, $2million\;m^3/year$ for agricultural water and $6million\;m^3/year$ for industrial water from multi-purpose dams. The maintenance water used for water conservation, ecosystem protection and landscape preservation is $158million\;m^3/year$, which is supplied from natural precipitation. Recently, the use of the other water for preservation of water quality and ecosystem protection in urban areas is increasing. The objectives of this study is to develop the seasonal forecast method of environmental water in urban areas (Seoul, Daejeon, Gwangju, Busan) and to evaluate its predictability. In order to estimate the seasonal outlook information of environmental water from Land Surface Model (LSM), we used the observation weather data of Automated Synoptic Observing System (ASOS) sites, forecast and hind cast data of GloSea5. In the past 30 years (1985 ~ 2014), precipitation, natural runoff and Urban Environmental Water Index (UEI) were analyzed in the 4 urban areas. We calculated the seasonal outlook values of the UEI based on GloSea5 for 2015 year and compared it to UEI based on observed data. The seasonal outlook of UEI in urban areas presented high predictability in the spring, autumn and winter. Studies have depicted that the proposed UEI will be useful for evaluating urban environmental water and the predictability of UEI using GloSea5 forecast data is likely to be high in the order of autumn, winter, spring and summer.

Natural Environment Protection and Restoration of Historic Landscaping Works For Preserving The Ancient City of Gyeongju

  • Hong, Kwang-Pyo;Lim, Hyo-Sun
    • Journal of the Korean Institute of Landscape Architecture
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    • v.38 no.5_2
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    • pp.206-213
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    • 2010
  • This paper looks into how to preserve Gyeongju's natural environment and to restore its historic landscaping works, one of the greate factor that compose ancient city as a way of wisely preserving Gyeongju, one of the oldest cities of Korea. Gyeongju, a city based in its natural environment, is formated inside of a basin of mountains and streams. Mountains and streams are the major two factors when on thinks of preserving the ancient city of Gyeongju. Four mountains surrounding the city play a direct role in marking coordinates of major city landmarks, while streams influence the structure and formation of the city in a great deal. More precisely, mountains should be able to be seen from the center of the city and streams should be restored in a way that they can serve as scenic identities of their time. Efforts should also be put into restoring such elements as ancient gardens, royal forests and water ways. The research team believes that such efforts themselves will be a great methods in reclaiming historic values and significance of places of Gyeongju. Restoring an ancient city is not limited merely restoring a city in an artificial concept, it reaches to preserving natural environment as a backdrop of the city and traces of landscaping works. When it comes to restoring an ancient city, one must understand that preserving natural environment and historic landscaping works are as valuable as restoring city structure or constructional elements. We believe that defining subjects of ancient city restoration must be more precise, clear and detail down the road.

A Study on Lives of the Young Elderly in Low Cost Small Housing Communities in America and Canada : Focused on Suburban Areas of Small Cities along Rural Counties (미국과 캐나다 연소노년층의 저비용 소형 주거단지 생활에 관한 연구 : 농촌지역 소도시 외곽을 중심으로)

  • Lee, In-Soo
    • Journal of Families and Better Life
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    • v.27 no.4
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    • pp.1-18
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    • 2009
  • This study has been performed to explore process of forming low cost small site housing communities and residential lives of the young elderly around small cities along rural counties of America and Canada, and suggest future implications for Korea. In this study, five low cost small housing zones such as cottage and mobile home parks in non-metropolitan counties of California and Ontario State such as Weed, Paradise, Sun City,, Wellington on the Lake, and Trenton were visited and the elderly residents and service experts were interviewed. The senior concentrating housing clusters were formed primarily from influx of both metropolitan and rural residents for the purpose of seeking warmful localities, traffic connections, and business purposes in theme focused production areas. On the other hand, residential lives in the zones are occasionally negatively influenced by unbalanced concentrations of elderly facilities such as nursing stations and funeral homes. For the future of Korean rural elderly policies, suggestions are made as follows: first, integrated forms of urban and rural township need to be settled as attracting places for early retiring people who seek low cost pastoral oriented but culturally activated environment. Second, a model town of mobile housing structures needs to be initiated as a measure of evaluating adaptation process of those movers. Third, a cooperation system among governmental ministries needs to be formed in order to integrate a long term master plan of establishing traditional rural town of independent housing districts. fourth, productive and active lifestyles need to be maintained for government lead retirement rural villages by limiting expansion of nursing related facilities around the independent areas. Fifth, visiting welfare service programs and volunteer groups need to be further developed for the housing area especially in winter time, when social integration and emotional comforts are extremely limited.

A Comparative Study on the Apartment Unit Plans According to the Living Environment Elements of Housing in Korea and China - Focused on Apartment cases in Seoul and Shanghai - (한.중 공동주택의 생활환경요인을 통한 단위평면 비교 연구 - 서울과 상하이 전통, 근대, 현대 공동주택 사례를 중심으로 -)

  • Liang, Fei;Yoon, Hea-Kyung;Park, Hyeon-Soo
    • Korean Institute of Interior Design Journal
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    • v.19 no.2
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    • pp.136-143
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    • 2010
  • This study aims to seek a direction of development in apartment interior planning method, considering residential condition and historical planning schemes in South Korea and China. In this study, South Korea and China's traditional housing and modern apartment unit was studied to identify environmental attributes of residence. For Korea, Banga, where upper class residents lived, and modern urban Hanok were chosen to be analyzed. For China, two types of housing wear studied: Sahapwon, original form of China housing, and Yinong house which is a typical Sanghai house. First, the elements of living environment in two major cities; Seoul and Sanghai was defined to analyze factors of traditional houses in both cities. Depending on those factors, relationship among traditional and modern housing types were compared and analyzed, focusing on unit plan case studies for a better understanding of living environment in South Korea and China. From this study, similarities and differences between apartment plans in Seoul and Shanghai was examined according to their residential style, surrounding natural environment and lifestyle factors. In Seoul's apartment, spacial composition and movement lines were mainly formed around the public space in Seoul, while public space of living and dining room was located at housing entrance area in the Shanghai's residential system, configuring narrow form of housing unit. In respect of the natural environment, the unit plan of rectangular form in Seoul was more efficient in day lighting and wind circulation than the unit plan of narrow form in Shanghai. It was also found that cultural differences of stand-up and seat life style influenced on the composition of unit plans in Seoul and Shanghai.n Apartment cases in Seoul and Shanghai.