• Title/Summary/Keyword: Air Transport Pattern

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A Study on Factors Affecting Korea's Air Freight Trade Field (우리나라 항공화물 무역 분야에 영향을 미치는 요인 연구)

  • Lim, Jae-Hwan;Kim, Young-Rok;Choi, Yun-Chul
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.28 no.4
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    • pp.117-124
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    • 2020
  • This study empirically analyzed air transport trade patterns using data for 30 years between Korea and its trading partners in order to identify specific factors that determine the size of Korea's air transport trade. Independent variables were GDP per capita, capital distance between countries, country area data and number of airports. In addition, it reflected whether it is a landlocked country and whether it has joined the OECD, APEC and ASEAN+3. According to the results of the analysis, it was found that the air cargo trade pattern in Korea is proportional to GDP per capita, and the scale increases as the distance is closer. In addition, the national area and the airport capital acted as a factor in increasing air transport trade. However, whether a country is a landlocked country did not show significant results in terms of trade, exports, and imports. The OECD, APEC, and ASEAN+3 variables were found to generally increase air transport trade.

Numerical Analysis of Wintertime Air Pollution in East Asia Region Using Long-Range Transport Model

  • Jang, Eun-Suk
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • v.4 no.2
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    • pp.103-110
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    • 2000
  • In order to understand the wintertime intermittent characteristics of the trans-boundary air pollutant transport observed in East Asia, a numerical simulation of the long-range transport of pollutants was applied using an atmospheric transport model(STEM-II). The numerical simulation was carried out for the entire month of January 1997 and specific atmospheric aerosol (including sulfate, nitrate, and other ion compounds0 observation data were compared from four observation sites(Cheju Island, Kanghwa Island, Dazaifu, and Fukue Island). The observation data revealed that concentration peaks were intermittently observed at 3 to 4-day intervals plus the four observation sites exhibited a very similar spatial variation. The horizontal and spatial scale of the heavily polluted air masses was analyzed based on numerical results. The mechanism of the intermittent transport of air pollutants was clearly explained by a comparison of the observed data with the numerical output. It was found that the wind pattern variations associated with the synoptic scale pressure system changes play an extremely important role in the transport of pollutants in this region.

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An Application of K-$\varepsilon$ Turbulence Model for Predicting Effect of a Rectanguler Obstacle with Heat Flux in a Solt-Ventilated Enclosure on Air Flow

  • 최홍림;김현태;김우중
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.34 no.E
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    • pp.30-44
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    • 1992
  • A modification of the TEACH-like computer program based on the k-$\varepsilon$ turbulence transport was applied for predicting air mixing patterns and temperature distributions in a rectangular, slot-ventilated enclosure having obstructions ; a rectangular obstacle with heat flux, solid walls separates the passage and the pig pens, and purlins beneath the ceiling. Air flow patterns were calculated for the cases with and without the purlin, extending 300mm beneath the ceiling. Comparisons of prediction data of Randall & Battams(1976) showed air flow pattern predicted well for the case without the purlin. Heat was accumulated at the corner of the left side of the solid wall and the right-upper region of the simulated pigs. However the air distribution pattern was completely different from data for the case with the purlin. The deviation from the observation may be attributed to the difference of the geometric configuation. Exploring the cause of the deviation should be conducted in a further study. Temperature stratification was also observed due to incomplete mixing. The obstruction in the route of the inlet air jet at inlet should be avoided since most of kinetic energy dissipates at the abstacle duet to impingement.

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A Study on the Long-Range Transport of Air Pollutans in the North East Asia (동북아시아 대기오염물질의 장거리 이동에 관한 연구)

  • 강동근;김선태;김정욱
    • Journal of Korean Society for Atmospheric Environment
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    • v.9 no.4
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    • pp.329-339
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    • 1993
  • Due to the global-convection currents, transboundary transport of air pollutants is widely observed in many regions of the world. This study was carried out to investigate the pattern of long-range transport of air pollutants in North East Asia, especially the impact of air pollutants originated in China and Japan on the air quality in Korea. From the meteorological data at the 850 mb surface from May 1986 through April 1987 at 54 obsevation stations in the North East Asia region, the backward and forward trajectories were calculated using interpolation method. And the contributions of pollution sources in neighbor countries to the air quality in Korea were analyzed. It was concluded that air pollution in China had a great influence on the air quality in Korea throughout the year : it could be transported to Korea just within 2 or 3 days most of the time. The trajectory analysis showed that pollution sources in Beijing. Liaoning Province, and Shandong Province, the most heavily industrialized areas in China., were the most influential for the air quality in Korea except for summer season. Durnig summer season, the air pollution in Shanhai and Japan could have moer influence on Korea. Such transboundary transport of air pollutants necessitate international cowork and cooperation in the region of North East Asia.

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Characteristics of Long-Range Transport of Air Pollutants due to Different Transport Patterns over Northeast Asia (동북아시아 대기오염물질의 이동 패턴에 따른 장거리 수송 특성 연구)

  • Park, Sin-Young;Kim, Yun-Jong;Kim, Cheol-Hee
    • Journal of Korean Society for Atmospheric Environment
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    • v.28 no.2
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    • pp.142-158
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    • 2012
  • This paper investigates the physical and chemical characteristics of long-range transport (LRT) process of air pollutants by employing the MM5-CMAQ and its comparison with local emission dominant (LED) case over northeast Asia. We first classified high air pollution days into LRT and LED cases based on the synoptic meteorological variables of vorticity and geostrophic wind speed/direction at a geopotential level of over 850hPa. LRT cases are further categorized into three types of transport patterns (LRT-I-III) according to the air mass pathways from source regions. LRT-I-III are originated from northern, central, and southern China, respectively, identified by back trajectory analysis. Three LRT-I-III groups have different and unique locations of high pressure and transport pathways. The chemical characteristics showed that the simulated spatial distributions varied in terms of locations of maximum concentrations and the temporal variation of surface concentrations. The primary air pollutants such as $NO_x$, $PM_{10}$ and $SO_2$ of all of three LRT cases are well transported into Korea peninsula with different concentration levels. Of LRT cases, LRT-II has the greatest effect on air quality of Korea peninsula, followed by LRT-I and LRT-III. In comparison with LRT, the LED case shows relatively higher air pollution concentrations in general, but showed a variety of different air quality levels following the emission strength pattern. These widely varying patterns are impling the case dependent multi-directional approach for the development of indicators of long-range transport process over northeast Asia.

Study on UAV Flight Patterns and Simulation Modelling for UTM (저고도 무인기 교통관리 체계에서 무인기 비행패턴 분류 및 시뮬레이션 모형 개발)

  • Jung, Kyu-sur;Kim, Se-Yeon;Lee, Keum-Jin
    • Journal of Advanced Navigation Technology
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    • v.22 no.1
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    • pp.13-19
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    • 2018
  • In this paper, we classified a flight pattern of unmanned aerial vehicle(UAV) which will be operating in UTM system and analyzed its flight pattern by purpose of use. Flight patterns of UAV are sorted into three patterns which are circling, monitoring and delivery. We considered four cases of industry areas using UAV which are agriculture, infrastructure monitoring, public safety & security(p.s.s) and delivery. It is necessary to build a simulation model as a verification tool for applying the flight pattern according to the use of UAV to the real UTM system. Therefore, we propose the simulation model of UAV with updating states over time. We applied simulation to UAV monitoring flight pattern, and confirmed that the flight was done by the given input data. The simulation model will be used in the future to verify that the UAV has various flight patterns and can operate safely and efficiently for the intended use.

New pattern of air market according to liberalization air transport between Korea and China (${\cdot}$ 중 항공자유화에 따른 항공시장의 변화와 대응)

  • Moon, Woo-Choon;Lee, Sang-Wook;Choi, Youn-Chul
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.15 no.2
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    • pp.32-39
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    • 2007
  • Air Transportation industry becomes more competitive that the restriction on new access to market were eased and relaxed. Liberalization of international air transport will continue, via bilateral and multilateral process. Korea, Japan, and China have expanded enormously the economic trade and cultural exchange bilaterally in the Northeast Asia, they are acknowledging the importance and necessity of improved connection, it order to face effectively other regional blocks of US-Canada, NAFTA, ASEAN, CLMV. In particular, nobody denies that it is urgent to liberalize bilaterally the air transport in Northeast Asia for promoting reciprocal benefits and prosperity. Recently while open skies bilateral agreements was signed between Korea-China in June, 2006. The agreements processes are too heavily influenced by flag carriers; leading to capacity/market sharing between the bilateral carriers in most markets, against the interest of consumers and overall economic interest of the nation. For successful operation of Northeast Air Market, it is need to set up development strategy paradigm by creating cross-border sub-regional (Northeast Asian) open skies bloc as well as preparing and creating of LCCs operations.

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Demand Pattern of the Global Passengers: Sea and Air Transport (글로벌 여객의 해상과 항공운송에 대한 수요패턴)

  • Mo, Soo-Won
    • Journal of Korea Port Economic Association
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    • v.27 no.1
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    • pp.1-11
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    • 2011
  • The main purpose of this paper is to estimate the impact of exchange rate and economic business activity on the passengers' demand for international transportation. The demand pattern depends upon the transport vehicles that the global passengers take. The global passengers' demand for transportation is modelled as exchange rate, industrial production and seasonal dummy variables. The seasonality is found in both water and air, but the former is far greater than the latter. All series span the period January 1990 to December 2008. The empirical results of this paper reveal that the income elasticity of sea transport is greater than that of air one, all of which are positive. The study also shows that the exchange rate has an significant impact on the demand for air transport, whereas it is insignificant in water transport. The impulse response function indicates that passengers increase steadily before peaking seven to eight months after the shocks to economic business activity and decline very slowly to its pre-shock level. The air passengers also respond negatively to the shocks in exchange rate and the impacts of exchange rate shock seem to decrease relatively slowly, while the water passengers respond positively after six months. The industrial production shocks remain above equilibrium for more than twenty four months, while the exchange rate shocks remain below equilibrium for more than twenty four months. Boosted by improved economic conditions worldwide, international tourism has recovered faster than expected from the impacts of the global financial crisis and economic recession of late 2008 and 2009. These facts suggest that the demand of global water transport has the high possibility of growing steadily and continuously.

The Vertical Distribution Patterns of Long Range Transported SO2 in Korea Peninsula (한반도 서해상으로 장거리 이동하는 SO2의 농도 및 연직분포 특징)

  • Han, J.S.;Ahn, J.Y.;Hong, Y.D.;Kong, B.J.;Lee, S.J.;Sunwoo, Y.
    • Journal of Korean Society for Atmospheric Environment
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    • v.20 no.5
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    • pp.671-683
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    • 2004
  • This study was carried out to understand long-range transport of $SO_2$ using aircraft measurements for the identification of it's horizontal and vertical concentration and distribution pattern. Thirteen missions of aircraft measurements have been done around 37$^{\circ}$00'/124$^{\circ}$30' from October 1997 to November 2001. Concentrations of $SO_2$ was 1.5~2.0 ppb in the below mixing layer, 0.6~1.1 ppb in the above mixing layer. $SO_2$ was found to be relatively higher than marine background level, 0.08~0.2ppb, indicating the western coast being influenced by long-range transport except for the summer season. The vertical distribution of $SO_2$ was classified into 3 groups using its vertical sounding and meteorology pattern; the first is linear decay pattern, the second is exponential decay pattern, and the last is gaussian distribution pattern in the below mixing layer, 2 patterns of linear decay and gaussian distribution patterns in the upper layer. It is founded that vertical distribution pattern is strongly dependent on meteorological condition, for example atmospheric stability and predominant air flow.

A Modeling Study on the Transport of Acid Pollutant by Regional Acid Deposition Model -Spacial Pattern and Variation of Air Pollutants on Eastern Asia and Central Part of Korea- (산성우모델에 의한 산성강하물의 수송에 관한 연구 - 동아시아 및 우리나라 중부지방의 대기오염물질 시공간분포 -)

  • Lee, Chong Bum;Cho, Chang Rae;Byun, Dae Won
    • Journal of Environmental Impact Assessment
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    • v.8 no.1
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    • pp.1-16
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    • 1999
  • The acid deposition and photochemical modeling study was performed on the Eastern Asia using Regional Acid Deposition Model(RADM). The results of this study show that horizontal distribution of $SO_2$, concentration and dry deposition flux was higher in Beking, Shanghai and central part of Korea. However distribution pattern of sulfate and $O_3$ concentration calculated by RADM were not similar to emission pattern. In daytime, $SO_2$, sulfate and $O_3$ were mixed to whole PBL but in nighttime because of inversion layer these pollutants were suppressed to lower level.

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