• Title/Summary/Keyword: The City Structures

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A Study on the Application of Soil Washing Technology for HOCs-Contaminated Soil Using Mixed Surfactants (소수성 유기오염물질로 오염된 토양에 대한 혼합 계면활성제를 이용한 토양세척기법의 적용성 연구)

  • Choi, Sang-Il;Lee, Jai-Young;Jang, Min
    • Journal of the Korean Society of Groundwater Environment
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    • v.4 no.2
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    • pp.103-108
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    • 1997
  • A series of batch tests were conducted to evaluate the design parameters for the application of soil washing techniques to the hydrophobic organic compounds (HOCs)-contaminated soil using mixed surfactants. Because the mixed surfactants form different structures of molecular aggregates from single surfactant, they were applied to improve the washing efficiency. Kinds of surfactants added, mixing ratio, and total concentration of mixed surfactants were evaluated. The uncontaminated soil was obtained from a country hill near Nock-Chun Station in Seoul. The portion of soil passing #4 (4.75 mm) sieve was used. The pH, organic contents and cation exchange capacity were 4.4, 1.6% and 4.08 meq/100 g, respectively The soil was artificially contaminated by n-dodecane. The 5% solution of OA-5 and OA-14 (1:1) showed 86% washing efficency. The 4% solution of SDS and OA-5 (1:1) showed 95% washing efficiency.

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Governance of a Growing Creative Industry Cluster: A Case Study on Brooklyn in the US (창조산업 클러스터의 형성과 발전의 거버넌스에 관한 연구: 미국 뉴욕 브루클린의 문화예술 산업클러스터를 사례로)

  • Shin, Dong-Ho
    • Journal of the Economic Geographical Society of Korea
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    • v.14 no.1
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    • pp.71-85
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    • 2011
  • Many of the old industrial cities in advanced economies have experienced deindustrialization since the 1960s. While some of them have been transforming their economic structures with new economies, such as arts and cultural industries, others have been seriously suffering from economic and social problems. Brooklyn Borough of New York City is one of the best examples which have gone trough rapid de-industrialization; but have been reasonably successful in recovering its economy with arts and cultural industries. This paper introduces the process of developing creative industry clusters, articulates major actors, and find out the governance of the clusters, using three Brooklyn's arts clusters, such as DUMBO, BAM and Williamsburg. Based on the case studies, the paper draws theoretical and policy implications applicable to the Korean circumstance.

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Efficiency of the Hierarchical Structure for a Bus Network (시내버스 노선망 위계구조의 효율성 분석 (대전시 사례분석을 중심으로))

  • Lee, Beom-Gyu;Jang, Hyeon-Bong
    • Journal of Korean Society of Transportation
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    • v.27 no.3
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    • pp.49-58
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    • 2009
  • Four alternative plans for the bus network in Daejeon metropolitan city, which have different hierarchical structure, were proposed : Alternative 1 represents a bus network without hierarchical structure, and Alternative 2, 3, and 4 represent bus networks with primary, intermediate, and advanced hierarchical structures, respectively. Efficiency of the alternative plans were evaluated based on the evaluation index including travel time cost, waiting time cost, and transition penalty cost. The travel time cost was decreased as the level of hierarchical structure gets higher until it reaches the extremely high level. As the level of hierarchical structure get higher, the waiting time cost significantly decreased while the transition penalty cost increased. Collectively, a bus network with hierarchical structure was shown to be more efficient than without it in the light of total travel cost. For the bus network with hierarchical structure, total travel cost shows a concave curve, which implies that there exists an optimal level of hierarchical structure in a bus network.

Improved Estimation of Leak Location of Pipelines Using Frequency Band Variation (주파수 대역 변화를 이용한 배관의 누수지점 추정 개선 연구)

  • Lee, Young-Sup;Yoon, Dong-Jin
    • Journal of the Korean Society for Nondestructive Testing
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    • v.34 no.1
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    • pp.44-52
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    • 2014
  • Leakage is an important factor to be considered for the management of underground water supply pipelines in a smart water grid system, especially if the pipelines are aged and buried under the pavement or various structures of a highly populated city. Because the exact detection of the location of such leaks in pipelines is essential for their efficient operation, a new methodology for leak location detection based on frequency band variation, windowing filters, and probability is proposed in this paper. Because the exact detection of the leak location depends on the precision of estimation of time delay between sensor signals due to leak noise, some window functions that offer weightings at significant frequencies are applied for calculating the improved cross-correlation function. Experimental results obtained by applying this methodology to an actual buried water supply pipeline, ~ 253.9 m long and made of cast iron, revealed that the approach of frequency band variation with those windows and probability offers better performance for leak location detection.

Research on the Safety Inspection Plan of Outdoor Advertising Safety Using Drone (드론을 활용한 옥외광고물 안전도 검사 방안에 관한 연구)

  • Jeong, Hee-Jeong;Lee, Suk-Hyung;Chang, Hye-Jung
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.13 no.6
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    • pp.530-538
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    • 2020
  • Safety inspections of outdoor advertisements are conducted to determine the aging status, specifications, and compliance with design documents. Regular inspections are conducted on outdoor advertisements from a safety perspective, as they not only undermine the aesthetic elements of the city but also could cause falls on roads or pedestrian paths. However, the current safety inspection methods are at risk of various accidents during the inspection advertisements on the outer wall of the building. And it is difficult to conduct in-depth inspections on them if they are fixed to the elevation of the building. Furthermore, there also is a risk of safety accidents, such as advertising structures falling onto a pedestrian path. Therefore, this paper aims to enhance the safety inspection system of outdoor advertisements using drones. This paper also intends to propose measures for facility inspection history management such as safety inspection cycle, maintenance, and removal of signboards.

Characterization of Hibiscus Chlorotic Ringspot Virus-Derived vsiRNAs from Infected Hibiscus rosa-sinensis in China

  • Han-hong Lan;Luan-mei Lu
    • The Plant Pathology Journal
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    • v.40 no.5
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    • pp.415-424
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    • 2024
  • Lots of progress have been made about pathogen system of Hibiscus rosa-sinensis and hibiscus chlorotic ringspot virus (HCRSV), however, interactions between H. rosa-sinensis and HCRSV remain largely unknown. Hereon, firstly, HCRSV infection in H. rosa-sinensis from Zhangzhou city of China was confirmed by traditional electron microscopy, modern reverse transcription polymerase chain reaction and RNA-seq methods. Secondly, sequence feature analysis showed the full-length sequence of HCRSV-ZZ was 3,909 nucleotides (nt) in length and had a similar genomic structure with other carmovirus. It contains a 5' untranslated region (UTR), followed by seven open reading frames encoding for P28, P23, P81, P8, P9, P38, and P25, and the last a 3-terminal UTR. Thirdly, HCRSV-ZZ-derived vsiRNAs were identified and characterized for the first time from disease H. rosa-sinensis through sRNA-seq to reveal interactions between pathogen ant plant host. It was shown that the majority of HCRSV-ZZ-derived vsiRNAs were 21 nt, 22 nt, and 20 nt, with 21 nt being most abundant. The 5'-terminal nucleotide of HCRSV-ZZ vsiRNAs preferred U and C. HCRSV-ZZ vsiRNAs derived predominantly (72%) from the viral genome positive-strand RNA. The distribution of HCRSV-ZZ vsiRNAs along the viral genome is generally even, with some hot spots and cold spots forming in local regions. These hot spots and cold spots could be corresponded to the regions of stem loop secondary structures forming in HCRSV-ZZ genome by nucleotide paring. Taken together, our findings certify HCRSV infection in H. rosa-sinensis and provide an insight into interaction between HCRSV and H. rosa-sinensis and contribute to the prevention and treatment of this virus.

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.

Fire-countermeasures of Majority-used Buildings -Centering around Busan Metropolitan City- (다중이용업소의 소방안전관리방안 -부산광역시(사상구, 사하구, 북구)를 중심으로-)

  • Lee, Soon-Goo;Kong, Ha-Sung;Han, Sang-Yong
    • Fire Science and Engineering
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    • v.22 no.1
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    • pp.54-60
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    • 2008
  • The occurrence of fires in heavily populated multiplex buildings is a serious concern. It causes a great threat to many people and a serious social problem. Whenever this kind of fire happens, the authorities are busy preparing partial countermeasures to control the crisis situations. Luckily, the government has enforced a special law regarding safety supervision of majority-used buildings to prepare the basic countermeasures for the buildings' safety. Recently, the multiplex buildings which have multi type compounds have increased in size by getting bigger and bigger. As there are many people who would need to escape and the complicated structures like mazes in buildings of this type, it is not only difficult to prevent a fire but also easy to cause a large loss of lives. For a better fire safety supervision of the buildings, there needs to be passers and owners' good sense of safety, fire proof of the buildings and education of the fire authorities.

Study for the Method to Secure the Safety of Fire-fighters in the Building Damaged by a Fire by Using Fire-resistant Design Theories - Mainly about Suggesting the Process and the Method for a Real-time Safety Evaluation by a Fire-fighter - (화재손상 건축 구조물에서 내화설계 이론을 활용한 소방관 안전확보 방안에 관한 연구 - 소방관에 의한 실시간 안전성평가 절차 및 방법의 제안을 중심으로 -)

  • Kwon, Yeongbae;Kwon, In-Kyu
    • Fire Science and Engineering
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    • v.30 no.1
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    • pp.86-95
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    • 2016
  • Weight-bearing building materials are substantially weakened under high temperatures, and this is evident through the collapse of structures once engulfed by fire. Currently, there is no scientific or technological process of evaluating the real-time structural stability of a building whcih is engulfed by flame. There are many building design specifications which aim to reduce the risk of fire, but little consideration given to fire officer safety while operating in a dangerous building. This paper aims to provide direction within building policy in order to ensure the safe evacuation of fire-fighters in case of an impending building collapse. This paper suggests evaluation criteria for buildings which are damaged due to fire, autilizing current information on fire-resistant building design and a fire-resistant capacity.

The evaluation of LNG Cryogenic Secondary pump vibration (LNG 초저온 2차 펌프의 진동 원인 분석)

  • Koh J. P.;Kim J. H.;Hong S. K.
    • Journal of the Korean Institute of Gas
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    • v.8 no.2 s.23
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    • pp.48-53
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    • 2004
  • Korea Gas Corporation(KOGAS) is a Liquified Natural Gas(LNG) supplier through out the Korea. LNG, which is imported wholly from foreign countries, is compressed 1/600 for easy transportation and is stored in a liquid state in the storage tanks at Incheon, Pyeongtaek and Tongyeong. At LNG receiving terminals, LNG is vaporized to natural gas before supplying to City Gas Consumer or Power Plant. The secondary pump is a equipment which compress LNG from $10 kgf/cm^2$ to $70 kgf/cm^2$. The secondary pump at Tongyeong LNG receiving terminal is consisted of two pumps in one underground PIT, and is connected to supporting structures. It is therefore expected that there is a vibration problem with the pump and was found that high level vibration was occurred in a low frequency band(5${\~}$10Hz). In this paper, the vibration of secondary pump was analyzed, and the main cause of vibration was found out.

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