• Title/Summary/Keyword: Air transport

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Spatial distribution and Short-range transport of ozone in coastal urban environment (연안도시지역 오존의 수평분포와 단거리수송)

  • 김유근;이화운;오인보
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2001.11a
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    • pp.73-74
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    • 2001
  • 도시지역의 오존농도는 배출원 환경 및 지형과 국지 기상조건에 의해 크게 영향을 받게 된다. 일반적으로 도시내 공단과 교통량이 많은 지역에서는 다량의 NO 배출에 의한 오존의 감소가 일어나는 반면 도시플륨의 풍하측의 지역에서는 오존의 축적과 함께 고농가 발생하게 된다 (Wang et al., 2001; Bower et al., 1994; Mckendry). 특히 연안도시의 경우 여름철 주로 발생하는 국지순환인 해풍에 의한 고농도를 경험하게 되는데, 이는 수면의 낮은 오존침적으로 인해 소멸의 영향이 적고 (Entwistle, 1997), 해풍역전으로 인한 연직혼합의 제한으로 인해 발생한다고 볼 수 있다 (Lu and Turco, 1994). (중략)

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Polychlorinated Biphenyls (PCBs) in the Bio-geochemistry of Oceans

  • Kannan, Narayanan
    • Journal of Marine Bioscience and Biotechnology
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    • v.2 no.4
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    • pp.201-208
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    • 2007
  • Polychlorinated biphenyls (PCBs) are anthropogenic contaminants found globally in water, ice, soil, air and sediment. Modern analytical techniques allow us to determine these chemicals in environmental matrices at parts per trillion levels or lower. Environmental forensic on PCBs opens up new avenues of investigation such as transport and fate of water masses in oceans, sedimentation, onset of primary production, migration of marine mammals, their population distribution and pharmacokinetics of drugs inside organisms. By virtue of persistence, bioaccumulation, bioconcentration and structure-activity relationship PCBs emerge as unconventional chemical tracers of new sort.

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A Study on the Development Strategies for the Light Rail Transit Industry (경전철 산업 발전방안 연구)

  • Chung Kyung-Ryul;Yoon Se-Kyun;Choi Yong-Hoon
    • 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.

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Environmental Development of Domestic Railroad (국내철도의 친환경적 발전방안)

  • 장세기;신민호
    • Proceedings of the KSR Conference
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    • 2002.05a
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    • pp.543-548
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    • 2002
  • Railroad has been one of major public transportations with the advantages of safety and schedule accuracy. However, the sustainable development will be the first principle in order to save the earth environment in the future, and the only transportation that satisfies it can continuously survive. Transportation has caused air pollution severely. Thus, the most environment-friendly means of transport should be chosen to maintain clean environment in the 21st century. Railroad is currently the best choice to fulfill the mission. But, the overall railroad technologies should be developed in consideration of clean environment to be a future leading transportation.

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Some Issues on China General Aviation Legislation (中國通用航空立法若干問題研究)

  • Shuang, Luan
    • The Korean Journal of Air & Space Law and Policy
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    • v.31 no.2
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    • pp.99-143
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    • 2016
  • General aviation and air transport are two wings of the civil aviation industry. Chinese air transport is developing rapidly, and has become the world second air transport system only second to US since 2005. However, Chinese civil aviation is far behind the world average level, and cannot meet requirements of economic construction and social development. The transition and structural adjustment of Chinese economy provide the general aviation with a unprecedented broad market. The prospect of general aviation is promising and anticipated. The development of general aviation industry needs the legislative supports, and the current legislative conditions of Chinese general aviation are undoubtedly far behind the realistic requirements. Accelerating the legislation in Chinese general aviation industry requires scientific legislation concept. First, Legislation must promote development of general aviation industry. The general aviation will serves as a Chinese emerging industry that boosts domestic demand, promotes employment and expedite domestic economic development. We should, based on both the concept of promoting the industrial development of general aviation and national industrial planning, enact and rectify relative laws and regulations. And we should also straighten out the relationship between aviation security and industrial development and promote the revolution of low-altitude airspace management in an all-round way, in order to improve the utilization rate of airspace resources, classify and establish airspace, simplify examination and approval procedure and intensify operation management. In addition, what we should do is to expedite the infrastructure layout construction, guide the differentiated but coordinated development of general aviation industries in various areas, establish a united supervision mechanism of general aviation, redistrict the responsibilities of Chinese Air Control Agency and set up legislation, law enforcement and judicial systems with clarified institutions, clear positioning and classified responsibilities, so as to usher in a new era of the legislative management of Chinese general aviation industry. Second, shift the focus from regulations to both regulations and services. Considering the particularity of the general aviation, we should use American practices for reference and take into account both regulation and service functions when enacting general aviation laws. For example, we should reduce administrative licensing and market supervision, and adopt "criteria" and "approval" management systems for non-commercial and commercial aviation. Furthermore, pay attention to social benefits. Complete social rescuing mechanism through legislation. It should be clarified in legislation that general aviation operators should take the responsibilities of, and ensure to realize social benefits of environmental protection and ecological balance .Finally, rise in line with international standards. Modify Chinese regulations which is inconsistent with international ones to remove barriers to international cooperation. Specify basic legislative principles. One is the principle of coordination. Realize coordination between the civil aviation and general aviation, between military aviation and civil aviation, and among departments. Two is the principle of pertinence. The general aviation has its own rules and specialties, needing to be standardized using specialized laws and regulations. Three is the principle of efficiency. To realize time and space values of general aviation, we should complete rules in aerospace openness, general aviation airport construction, general aviation operations, and regulation enforcement. Four is the principle of security. Balance the maximum use of resources of Chinese airspace and the according potential threats to Chinese national interests and social security, and establish a complete insurance system which functions as security defense and indemnificatory measure. Establish a unified legal system. Currently, the system of Chinese general aviation laws consists of national legislation, administrative laws and regulations and civil aviation regulations (CAR). Some problems exist in three components of the system, including too general content, unclear guarantee measures, incomplete implementation details, and lacking corresponding pertinence and flexibility required by general aviation regulations, stringency of operation management and standards, and uniformity of standards. A law and regulation system, centered on laws and consisting of administrative laws regulations, industrial regulations, implementation details, industrial policies and local laws and regulations, should be established. It is suggested to modify the Civil Aviation Law to make general aviation laws complete, enact the Regulations of General Aviation Development, and accelerate the establishment, modification and abolition of Chinese general aviation laws to intensify the coordination and uniformity of regulations.

A Proposal on the Improvement of Obstacle Limitation Surface and Aeronautical Study Method (장애물 제한표면과 항공학적 검토방법의 제도 개선에 관한 제언)

  • Kim, Hui-Yang;Jeon, Jong-Jin;Yu, Gwang-Eui
    • The Korean Journal of Air & Space Law and Policy
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    • v.34 no.1
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    • pp.159-201
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    • 2019
  • Along with Annex 14 Volume I establishment in 1951 and the set-up of restriction surface around the runway, aeronautical technique and navigation performance achieved dazzling growth, and the safety and precision of navigation greatly improved. However, restrictions on surrounding obstacles are still valid for safe operation of an aircraft. Standards and criteria for securing safety of aircraft operating around and on airport is stated in Annex 11 Air Traffic Services and Annex 14 Aerodrome etc. In particular, Annex 14 Volume I presents the criteria for limiting obstacles around an airport, such as natural obstacles such as trees, mountains and hills to prevent collisions between aircraft and ground obstacles, and artificial obstacles such as buildings and structures. On the other hand, Annex 14 Volume I, in the application of the obstacles limitation surfaces, apply the exception criteria, as it may not be possible to remove obstacles that violate the criteria if the aeronautical study determines that they do not impair the safety and regularity of aircraft operation. Aeronautical study has been applied and implemented in various countries including United States, Canada and Europe etc. accordingly, Korea established and amended some provisions of the Enforcement rules of the Aviation Act and established the Aeronautical study guidelines to approve exceptions. However, because ICAO does not provide specific guidelines on procedures and methods of Aeronautical study, countries conducting aeronautical study have established and applied their own procedures and methods. Reflecting this realistic situation, at the 12th World Navigation Conference and at the 38th General Assembly, the contracting States demanded a reexamination of the criteria for current obstacle limitation surfaces and methods of aeronautical study, and the ICAO dedicated a team of experts to prepare new standard. This study, in line with the movement of international change in obstacle limitation surface and aeronautical study, aims to compare and analyze current domestic and external standards on obstacle limitation and height limits, while looking at methods, procedure and systems for aeronautical study. In addition, expecting that aeronautical study will be used realistically and universally in assessing the impact of obstacles, we would recommend the institutional improvement of the aeronautical study along with the development of quantitative analysis methods using the navigation data in the current aeronautical study.

Effects of Working Fluid Filling Ration and Heat Flux on Correlations of Heat Transfer Coefficient in Loop Thermosyphon

  • Chang, Ki-Chang;Lee, Young-Soo
    • International Journal of Air-Conditioning and Refrigeration
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    • v.10 no.3
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    • pp.153-161
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    • 2002
  • Due to the coupling between momentum and energy transport theoretical analysis of the loop performance is very complicate, therefore it is necessary that these problems be solved by experimental investigation before applying the loop thermosyphon to heat exchanger de-sign. The evaporator and condenser of the loop thermosyphon were made of carbon-steel, and distilled water was used as working fluid in the experiments. From the experimental data correlations of heat transfer coefficient for evaporator and condenser sections were obtained. For heat fluxes in the range of 13000~78000 W/$m^2$, the correlation equations of heat transfer coefficients in evaporator and condenser predict the experimental behavior to within $\pm$5% and $\pm$20% respectively.