• Title/Summary/Keyword: region-expansion

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Study of Base DRAG Prediction With Chamber Pressure at Super-Sonic Flow (초음속 유동에서 챔버 압력에 따른 기저항력 변화 예측)

  • Kim, Duk-Min;Nam, Junyeop;Lee, Hyoung Jin;Noh, Kyung-Ho;Lee, Daeyeon;Kang, Dong-Gi
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.48 no.11
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    • pp.849-859
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    • 2020
  • The semi-empirical equation and commercial computational tool were used to predict the base drag of a guided missile with free-stream Mach numbers and chamber pressures, and the results were generally agree each other. Differences in flow characteristics and base drags were observed with over/under expansion conditions by the nozzle. Under the over-expansion condition, the base pressure decreased as the expansion fan was generated at upper region of the base, and base pressure decreased further with increasing free-stream Mach number as the expansion becomes strong. Under the under-expansion conditions, a shock wave was generated around the base by the influence of the nozzle flow, which increased the base pressure, and the effect increased as the chamber pressure increased. Under the same chamber pressure condition, as the free-stream Mach number increases, the characteristic that the base pressure decreases as the shock wave generated at the base moves downstream was observed.

Science, Commerce, and Imperial Expansion in British Travel Literature: Hugh Clifford's and Joseph Conrad's Malay Fiction

  • Kil, Hye Ryoung
    • Journal of English Language & Literature
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    • v.57 no.6
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    • pp.1151-1171
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    • 2011
  • Conrad's novels, specifically the Lingard Trilogy-Almayer's Folly, An Outcast of the Islands, and The Rescue-and Lord Jim, set in the Southeast Asian or Malay Archipelago can be considered travel literature that played a significant role in British imperial expansion. Conrad's Malay novels were based not only on his experience in the region during his commercial journey but also on information from earlier travel writings about the Malays and their customs, including James Brooke's journals. The English traders in Conrad's novels, namely Lingard and Jim, were partly modeled on Brooke, the White Rajah, who founded and ruled the English colony on the northwest of Borneo in the 1840s. The white traders in Conrad's novels, who act as enlightened rulers, represent the British commercial expansionism, which was obscured by the phenomenon of the civilizing mission in the late nineteenth century. On the other hand, the colonial official Clifford's tales and novels about British Malaya demonstrate the typical travel accounts of the late nineteenth century that stress the civilizing mission over commercial exploitation. The concept of the enlightening mission was rooted in evolutionary anthropological thinking, which developed as part of the natural history in the early nineteenth century. In fact, the development of natural history, stimulating British expansion in search of commercially exploitable resources and lands, enabled travel writing as the collection of natural knowledge to become a profitable business. In Conrad, the white characters are mainly traders acting as colonial rulers, while in Clifford, they are scientific rulers with their commercial interests rarely apparent. In sum, Conrad's novels reveal that the new imperialism of the civilizing mission is still a commercial one, which disturbs rather than contributes to the imperial expansion-in contrast to other travel literature such as Clifford's.

An Experimental Study of the Turbulent Swirling Flow and Heat Transfer Downstream of an Abrupt Expansion in a Circulat Pipe with Uniform Heat Flux (급확대관내에서 류유선회유동의 열전달에 관한 연구)

  • 권기린;허종철
    • Journal of Ocean Engineering and Technology
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    • v.10 no.3
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    • pp.138-152
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    • 1996
  • Many studies of heat transfer on the swirling flow or unswirled flow in a abrupt pipe expansion are widely carried out. The mechanism is not fully found evidently due to the instabilities of flow in a sudden change of the shape and appearance of turbulent shear layers in a recirculation region and secondary vortex near the corner. The purpose of this study is to obtain data through an experimental study of the swirling flow and heat transfer downstream of an abrupt expansion in a circular pipe with uniform heat flux. Experiments were carried out for the turbulent flow nd heat transfer downstream of an abrupt circular pipe expansion. The uniform heat flux condition was imposed to the downstream of the abrupt expansion by using an electrically heated pipe. Experimental data are presented for local heat transfer rates and local axial velocities in the tube downstream of an abrupt 3:1 & 2:1 expansion. Air was used as the working fluid in the upstream tube, the Reynolds number was varied from 60, 00 to 120, 000 and the swirl number range (based on the swirl chamber geometry, i.e. L/d ratio) in which the experiments were conducted were L/d=0, 8 and 16. Axial velocity increased rapidly at r/R=0.35 in the abrupt concentric expansion turbulent flow through the test tube in unswirled flow. It showed that with increasing axial distance the highest axial velocities move toward the tube wall in the case of the swirling flow abrupt expansion. A uniform wall heat flux boundary condition was employed, which resulted in wall-to-bulk temperatures ranging from 24.deg. C to 71.deg. C. In swirling flow, the wall temperature showed a greater increase at L/d=16 than any other L/d. The bulk temperature showed a minimum value at the pipe inlet, it also exhibited a linear increase with axial distance along the pipe. As swirl intensity increased, the location of peak Nu numbers was observed to shift from 4 to 1 step heights downstream of the expansion. This upstream movement of the maximum Nusselt number was accompanied by an increase in its magnitude from 2.2 to 8.8 times larger than fully developed tube flow values.

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Clinical Feasibility of Postural Alignment Exercise on Decreased Chest Function Secondary to Thoracic Kyphosis: A Single-Subject Study Design

  • Jang, Hyun-Jung;Kim, Suhn-Yeop;Oh, Duck-Won
    • The Journal of Korean Physical Therapy
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    • v.26 no.3
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    • pp.169-174
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    • 2014
  • Purpose: This study demonstrated a postural alignment exercise as conservative management strategy for a woman with excessive thoracic kyphosis presenting decreased chest function, and reports its results. Methods: A 21-year-old woman with thoracic kyphosis presenting limited chest function. The exercise program underwent for 30 min in the intervention phase, which consisted of exercises to improve the strength of back extensor and to stretch anterior chest region. Outcome measures comprised the severity of thoracic kyphosis and chest function (vital capacity [VC], forced expiratory volume in a second [FEV1], and chest expansion length). Results: The thoracic kyphotic angle decreased by 23.6% ($9.38^{\circ}$) and 25.4% ($10.58^{\circ}$) in the intervention and follow-up phases respectively. Also, chest function was improved in the intervention (VC: 3.7% [$0.10{\ell}$], FEV1: 17.1% [$0.39{\ell}$], and chest expansion length: 17.1% [0.96 cm]), and the improvement was maintained during the follow-up phase (VC: 4.8% [$0.13{\ell}$], FEV1: 17.1% [$0.39{\ell}$], and chest expansion length: 64.3% [1.81 cm]). Conclusion: These findings suggest that the postural alignment exercise was favorable for improving chest function of a woman with thoracic kyphosis.

A Study on the Influences of Urban Area Expansion by Developing a Large Scale Residential District on Changes of Urban Spatial Structure - In the Daejeon Metropolitan City - (대규모 택지개발에 의한 도시확장이 도시 공간구조변화에 미치는 영향분석 - 대전광역시를 대상으로 -)

  • Jeong, Young-Hwan;Kang, In-Ho
    • Journal of the Korean housing association
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    • v.17 no.5
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    • pp.137-146
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    • 2006
  • This study was aimed to analyze the influences of urban expansion by developing a new large scale residential district on changes of whole urban spatial structure. For the analysis, time serial analysis was conducted on the Daejeon Metropolitan City by using the space syntax method. The results of the study are as follows ; First, an expansion of urban area led to lower both of the local and global integration levels, second, the spatial occupation ratio of upper 10% in the whole integration showed that old city center was separated, and moved to the Dunsan District, third, the results also showed that an integration of the old city center region maintained a high level in spite of a movement of city center and its local integration still had highest level so that the old city center will take one of the two city center roles together with Dunsan District.

IPR Issues in World contents Industry - Japanese countermeasures and Its Lessons to Korea - (세계 컨텐츠산업의 지적재산권 문제 - 일본의 대책과 한국에의 시사점 -)

  • Chung, Su-Won
    • Journal of Arbitration Studies
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    • v.19 no.2
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    • pp.229-243
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    • 2009
  • The content industries environment has been undergoing significant changes due to rapid technological innovation and content market expansion. Interest in the industry is growing fast both in Asia and Europe. However, in Japan content industries are showing almost zero growth with no increase in overseas expansion. Until now, Japanese content industries have been able to grow based on domestic demands. Many different factors contributed to today's zero growth in Japanese content industries. Two main reasons are: 1) Their lack of interest in overseas expansion and 2) Insufficient investment in domestic human resources development. Considerable amounts of Japanese contents including films, music, games, and animations have been distributed in many Asian countries and today piracy problems in the region are at a serious level. According to 2004 records pirated editions accounted for 85%, 16%, 19%, and 36% in China, Korea, Hong Kong, and Taiwan respectively. Pirated editions bring economic losses to Japanese copyright profits. Making it worse, they weaken the motivation to create content and make it hard to activate cultural exchanges. Losses from copyright violations in Japanese content industries are expected to keep increasing in the future. In order to make Japan competitive and grow it is crucial to take proper measures to protect copyright infringements. This study considers the current situation of the Japanese content market, infringement issues in content which is causing many problems in Asian countries, including China, and facts about losses caused by this problem.

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The Development of China′a Marin Fisheries and Reorganization of Region Fisheries in the East China Sea (동중국해에서 중국 해면어로어업의 전개와 지역어업의 재편)

  • 김대영
    • The Journal of Fisheries Business Administration
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    • v.31 no.2
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    • pp.27-45
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    • 2000
  • This study discusses the development structure of China's Marine Fisheries in the East China Sea. China's marine fisheries have developed since the 1980s along with it's economic expansion. The total catch in the East China Sea has increased especially during the 1990s. The Chinese fishery has developed remarkably through individual management, expansion of their fishing grounds from inshore to off-shore, and increase of the catch in both pelagic and bottom species. In other words, the trawl fishery in China has led to higher production. We can say that the progress in Chinese fisheries is the result of their expansion policy. Their boats have been coming closer and closer to the Japanese and Korea fishing grounds during the 1990s. Chinese fisheries is exploiting the low cost and thus strengthening its quantity. Based on rising fish price, expanding domestic fish markets as well as expels, China is enjoying the high income. However, in trawl fishery, productivity is stagnant and profit is going down due to the rising cost. In accordance with the new 200 mile EEZ system in the East China Sea, China's fisheries will be restricted mostly by the new regulation which requires the reduction of fishing efforts and the application of resource management.

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A study on the establishment and regional strunture of Seoul metropolitan region (서울대도시권역의 설정과 지역구조에 관한 연구)

  • ;;Lee, Hee-Yeon;Song, Jong-Hong
    • Journal of the Korean Geographical Society
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    • v.30 no.1
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    • pp.35-56
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    • 1995
  • During the last two decades, Korea has achieved remarkable economic growth. In this process the nation has become urbanized and industrialized. But we have also encountered widening regional disparity, housing shortage of larger cities, transportation congestion, environmental pollution and many other problems. Rapid increasing urbanization and continuous migration toward Seoul since the late 1960s have been one of the major concerns of government. Government has sought ways to moderate the population increase in Seoul. The regulation which include new town development near Seoul and dispersion strategies of higher education and other administration and living facilities outside of Seoul havemade a great expansion of the spatial influence of Seoul city. Seoul metropolitan reaion has evolved as the most powerful center of political and economical spaces. Generally within a metropolitan region, there exists a growing mutual interdependence economically, as well as socially between a central city and its surrounding area. Seoul metropolitan region manifests itself not only as a coherent system of urbanized regions, but also as an integral part of the daily urban system. The surrounding Gyunggi province and Seoul city become closely linked both economically and functionally, constituting true functlonai urban system. This study is primarily undertaken with the purpose of delineation of the sphere of influence of Seoul city in 1990. At the time of 1985, Seoul metropolitan region was delineated according to the result of the study which was performed by Korea Research Institute for Human Settlements. Afterward, the rapid speed of metropolitanization process with dramatic increase in mobility through the provision of wider transportation system across the Capital region have evolved, resulting in the great expansion of the spatial influence of Seoul city. So this study examines the expanded area of Seoul metropolitan regin during the period of 1985-90. In order to delineate Seoul metropolitan region, the indices of urbanization and functional linkage are selected. Variables included in the measurement of the urbanization level are agricultural structure, population characteristics, manufacturing and service industries, and cultural aspects such as newspaper circulation, the ratio of car ownership and piped water supply. Variables included in the measurement of functional linkage are commuting, shopping pattern, centralized service such as medical facilities and trade of agricultural products. The standardization method and factor analysis are employed in making the delineation of Seoul metropolitan region. According to the result of this study, 2 cities, 8 Eups and 46 Myuns are included Seoul metropolitan region in 1990. If we compare this delineated area in 1990 to that of 1985, we can find the distinctive pattern of expanded axes according to the main transportation routes such as Seoul-Suweon, Seoul-Gwangju, Seoul-Incheon. In 199O, all the Gyunggi province, except a few Myuns located at the north and northwest part of Gyunggi province, are included in Seoul metropolitan region. Furthermore, this study attempts to the analysis of regional structure of Seoul metropolitan region according to the functional characteristics of each city and Gun. Variables included in this analysis are the new residential function, manufacturing function, service function, education and infermation function, public facility function and agricultural function. Factor analysis and cluster analysis are employed in making regionalization. Seoul metropolitan reaion is subdivided into four subregions which reflect different functional specialization. The first group is the specialized region of newly formed residential function. The second group is the specialized reaion of manufacturing function. The third group is the specialized region of service function. And the fourth group has little specialized in terms of manufacturing, service, and residential function. But this region has some potentiality of development when Seoul metropolitan region grow continuously. Seoul metropolitan region accounted for 43% of national population, despite 11.8% of national land size in 1990. Although Seoul metropolitan region enjoys important agglomeration economies, it also has huge social cost in the form of transportation congestion, housing shortage, rapid increase of land value, environment pollution, and etc. Efficient metropolitan plan making is a vital element in promoting Seoul's economic development and providing high quality living environment at low cost. In the light of the result of this study, the outer ring of Seoul metropolitan region, especially northeastern part, are underdeveloped compared to overdeveloped southwestern area. It is needed to develop the guidelines for the implement of the growth control and management plan, inducing more balanced development for whole Seoul metropolitan reaion.

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A Critical Review on the Government-led Region-based Business-University-Research Institute Collaboration Policy in Korea (한국의 정부주도형 지역 산학연 협력 정책에 대한 비판적 고찰)

  • Jung, Sung-Hoon
    • Journal of the Korean association of regional geographers
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    • v.21 no.4
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    • pp.631-638
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    • 2015
  • The aim of this article is to analyze problems of the government-led region-based business-university-research institute collaborations(BURIC) in Korea and to present main issues for solving and improving the current 'cul-de-sac' of these collaborations. The main problem of such collaborations is the wider divergence of opinions by actors who implement projects of the BURIC funded by the central and local government. Due to this problem, each region, mainly the non-Seoul metropolitan region, in Korea has problems of the system and people for BURIC. Within this context, main issues of the government-led and region-based BURIC is focused upon BURIC for the start-up of self-employment and the expansion of companies' lifespan. Since 2000, experts and policy-makers have emphasized business- (or company-) centered BURIC rather than University-focused one. This point of view should be improved or corrected. That is to say, policies of BURIC are in need of focusing upon the start-up for self-employment and the expansion of companies' lifespan.

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A study on expansion of lean burn limit with direct injection of the heavy-duty CNG engine (대형 CNG기관의 직접분사화에 의한 희박한계확장)

  • Park, Jung-Il;Chung, Chan-Moon;Noh, Ki-Chul;Lee, Jong-Tai
    • Proceedings of the KSME Conference
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    • 2007.05b
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    • pp.3282-3287
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    • 2007
  • Lean combustion is one of the most promising method for increasing engine efficiency and reducing the exhaust emission from SI gas engines. Due to the possibility of partial burn and misfire, however, under lean burn operation, stable flame kernel formation and fast burn rate are needed to guarantee a successful subsequent combustion. Experiment data were obtained on a single-cylinder CNG fueled SI engine to investigate the effect of direct injection, spark timing and variation of injection timing. Experimental results show that lean burn limit is ${\lambda}$=1.3 with port injection, and expansion of lean burn limit ${\lambda}$=1.4 with direct injection method, due to increase of turbulence intensity in cylinder and stratified charge. Combustion duration in lean region is improved by using the variation of injection timing.

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