• Title/Summary/Keyword: Air transport

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Numerical Studies of Transient Opposed-Flow Flames using Adaptive Time Integration

  • Im, Hong-Geun
    • Journal of Mechanical Science and Technology
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    • v.14 no.1
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    • pp.103-112
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    • 2000
  • Numerical simulations of unsteady opposed-flow flames are performed using an adaptive time integration method designed for differential-algebraic systems. The compressibility effect is considered in deriving the system of equations, such that the numerical difficulties associated with a high-index system are alleviated. The numerical method is implemented for systems with detailed chemical mechanisms and transport properties by utilizing the Chemkin software. Two test simulations are performeds hydrogen/air diffusion flames with an oscillatory strain rate and transient ignition of methane against heated air. Both results show that the rapid transient behavior is successfully captured by the numerical method.

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A Study for Long-Range Transport of Air Pollutants Related to the Local Circulation (국지순환과 대기오염물질의 장거리 수송에 관한 연구)

  • 이화운;김유근;정우식
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2000.04a
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    • pp.187-190
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    • 2000
  • 대기오염물질의 장거리 수송과 관련해서는 다음의 두 가지 과정이 지배적으로 나타난다. 하나는 종관바람장에 의해 먼 거리를 이동하는 과정을 들 수가 있고(Cox et at. 1975, Apling et al. 1977) 다른 한가지는 열적으로 형성된 국지순환계에 의해 수송되는 과정을 들 수 있다. (Kurita and Ueda 1990) 이러한 과정 중에서 대기오염물의 고농도에 의한 피해가 부각되는 것은 후자라고 할 수 있다 이는 고농도의 대기오염문제는 종관장의 영향이 적어서 오염물의 확산이 부진한 날에 나타나기 때문이다. (중략)

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항공사 시장성과의 결정요인 분석

  • Kim, Gyeong-Suk
    • The Journal of Aerospace Industry
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    • s.66
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    • pp.45-56
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    • 2003
  • Airlines service is very important so as to overcome the rapid environmental changes of the air transportation market at home and abroad. Author investigates the impact of Determinants on the performance of airlines in all the world. Three variables of performance measurement were used : revenue, net profit, and passengers. Data analyses were based on service ranking, financial and passenger information of the world's top 50 Airlines collected from Business Traveller, World Air Transport Statistics and Airline Business. The findings of this study could be summarized as follows : Service ranking was not related to the airlines performances such as revenue, net profit, passengers and so fourth. But airlines size(employees, fleet size) was related to the airlines performances such as passengers and revenue passenger.

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Evidences of Short-range and Long-range transport of Gas Phase PCBs in Rural Air (교외지역에서 대기 중 가스상 PCBs의 발생원 파악을 위한 연구)

  • 여현구;최민규;천만영;선우영
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2002.11a
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    • pp.139-140
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    • 2002
  • 반 휘발성 유기화합물(Semivolatile organic compounds; 이하 SOCs)은 높은 중기압과 낮은 반응성 때문에 지구 전역에 폭넓게 존재하고 있다. SOCs중 Polychlorinatd Biphenyls(이하 PCBs)는 난분해성 및 친지질성에 특성으로 환경중에서 순환하기 때문에 최근 들어 맡은 관심의 대상이 되고 있다. 이들 대부분은 태초의 환경과 모든 matrix(예, 토양, 식물, 대기, 수계 등)에서 발견되어 지고 있다 이처럼 PCBs는 독성 유발물질로 관리되고 있으며 먹이연쇄를 통해 생농축성(bioaccumulation)을 야기 시킬 수 있다. (중략)

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Study on Evaluation Criteria for Multimodal Transport Routing Selection (복합운송경로 선정을 위한 평가기준에 관한 연구)

  • Kim So-Yeon;Choi Hyung-Rim;Kim Hyun-Soo;Park Nam-Kyu;Cho Jae-Hyung;Park Yong-Sung;Cho Min-Je
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2006.06b
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    • pp.265-271
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    • 2006
  • According to globalization of world economy by extension of production, sales and distribution all around the world and international transportation system changed into a transport system that puts great importance on speediness and value-added services, international transport system is changing into a Multimodal Transport Routing centered system that systematically connects marine, air and rail transports. Due to such changes production, sales and distribution must be provided in time and Multimodal Transport Routing, which can provide multi-dimensional logistics services to customers of global network, is needed but information connection for international transport and connection system between transport modes are insufficient and can not be activated. Especially in Korea, selection standard of 3rd party logistics companies and transport companies is presented, but logistics exclusive companies, which plan and execute the transportation, can't present a systematic evaluation standard for international Multimodal Transport Routing, selection. Thus, this research surveys important previous studies about Multimodal Transport Routing, selection, derives an evaluation standard for Multimodal Transport Routing, selection through interview with company officials, and presents a theoretical basis for Multimodal Transport Routing, selection through systematic analysis of Multimodal Transport Routing, selection using Analytical Hierarchy Process (AHP).

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An Experimental study on heat transfer of a falling liquid film in air channel flow (채널내 공기유동이 있는 유하액막의 열전달특성에 관한 실험적 연구)

  • Oh, Dong-Eun;Kang, Byung-Ha;Kim, Suk-Hyun
    • Proceedings of the KSME Conference
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    • 2007.05b
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    • pp.2291-2296
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    • 2007
  • Thermal transport from vertical heated surface to falling liquid film in a channel has been investigated experimentally. Air-flow is introduced into channel to make a counter flow against falling liquid film. This problem is of particular interest in the design of direct contact heat exchange system, such as cooling tower, evaporative cooling system, absorption cooling system, and distillation system. The effects of channel width and air flow rate on the heat transfer to falling liquid film are studied in detail. The results obtained indicate that heat transfer rate is gradually decreased with an increase in the channel width without air flow as well as with air flow in a channel. It is also found that heat transfer rate of air-flow is increased while heat transfer rate of falling liquid film is decreased with an increase in the air flow rate at a given channel width. However, total heat transfer rate form the heated surface is increased as the air flow rate is increased.

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A Study on Air Logistics Process Simplification based on RFID(1) (RFID를 적용한 항공물류 프로세스 간소화에 관한 연구(1))

  • Lee, Tae-Yun;Lee, Doo-Yong;Li, Zhong-Shi;Na, Hyeong-Seok;Lee, Chang-Ho
    • Journal of the Korea Safety Management & Science
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    • v.10 no.2
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    • pp.163-168
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    • 2008
  • These days, international air-logistics demand is getting bigger and bigger by increasing in trading volumes of export and import of Asia. It makes the air logistics of stakeholder to invest in air logistics facilities and information systems for meeting the growth of air transportation. However there are some problems that the efficiency of investment is not good by duplicately investing in information systems and moreover not compatible with each other because the stakeholder is investing in individual information system and air logistics facilities instead of constructing the integrated infrastructure. In this paper, we investigated the export, import, and transshipment process of air logistics to simplify air logistics process through the RFID(Radio Frequency Identification) application and the 4PL system.

Development of Air Cleaning System for Railroad Vehicles (차세대 객차용 청정시스템 개발)

  • Park, Duck-Shin;Cho, Young-Min;Kwon, Soon-Bark;Park, Eun-Young;Kim, Se-Young;Jung, Mi-Young
    • Proceedings of the KSR Conference
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    • 2008.06a
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    • pp.2109-2113
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    • 2008
  • As the standard of living is higher, the passengers using public transportations desire better qualities of environment as well as more comfortable indoor environment. In case of train, the passengers' comfort in passenger cabin is one of the most important elements to be competitive with other transport systems. The indoor air quality of the cabin should be managed properly, because many passengers travel for a long time in the small space of $144\;m^3$. For proper management of the air quality, the heating, ventilation and air conditioning (HVAC) system is required for the ventilation of the compartment. To maintain comfortable environment in the compartment, the automatic ventilation system is needed to exchange the indoor air with fresh air or clean indoor air. In this study, we investigated the indoor air quality (PM-10, $CO_2$, and VOCs) in the compartment of train. In addition, type and pattern of PM-10 has been analyzed through the clustering analysis. Based on the analysis, we could found that the fine particulate matters in the compartment can be a serious hazard to human. To control the concentration of PM-10 and $CO_2$ air cleaners were developed. Through this study, it is expected that people who take a train will be in a more comfortable environment.

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An Experimental Study on Heat Transfer of a Falling Liquid Film in Air Channel Flow (채널내 공기유동이 있는 유하액막의 열전달특성에 관한 실험적 연구)

  • Oh, Dong-Eun;Kang, Byung-Ha;Kim, Suk-Hyun;Lee, Dae-Young
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.32 no.5
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    • pp.335-341
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    • 2008
  • Thermal transport from vertical heated surface to falling liquid film in a channel has been investigated experimentally. Air-flow is introduced into channel to make a counter flow against falling liquid film. This problem is of particular interest in the design of direct contact heat exchange system, such as cooling tower, evaporative cooling system, absorption cooling system, and distillation system. The effects of channel width and air flow rate on the heat transfer to falling liquid film are studied in detail. The results obtained indicate that heat transfer rate is gradually decreased with an increase in the channel width without air flow as well as with air flow in a channel. It is also found that heat transfer rate of air-flow is increased while heat transfer rate of falling liquid film is decreased with an increase in the air flow rate at a given channel width. However, total heat transfer rate from the heated surface is increased as the air flow rate is increased.

A Study on $CO_2$ Emission Estimation linked Port Action (항만 연계활동에 기초한 이산화탄소 배출량 추정)

  • Kim, Hwan-Seong;Jo, Min-Ji
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2010.04a
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    • pp.173-174
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    • 2010
  • As the quantity of goods transported, port industry and inland transport industry have developing to transport 630million ton goods annually. And the inland transport industry consists of ground transport for almost 80% of total transported goods. But, ground transport causes some serious problems especially the emission of greenhouse gases from trucks. According to issue "global warming", many regulations and agreements with countries in the world are becoming necessary and it is being fulfilled now. It is sure that Korea will have duty to reduce CO2 emission from 2013. Thus inland transport must cut off CO2 emission level. Therefore this paper will address that the calculation of CO2 emission under route of transportation container from six major container ports in Korea. And then, it will predict CO2 emission of inland transport industry according to increasing container traffic rate at ports.

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