• Title/Summary/Keyword: Local transport

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Influences of Air Trajectories on the Variations of Carbon Monoxide in Major Cities in Korea for the Year of 1999 (1999년 기류의 이동궤적에 따른 우리나라 주요 도시의 일산화탄소 농도 변화)

  • 김영성;김영주;김진영
    • Journal of Korean Society for Atmospheric Environment
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    • v.17 no.6
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    • pp.451-461
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    • 2001
  • Backward trajectories were calculated from five urban areas in Korea in 1999 in order to assess the effects of long-range transport on the air quality variations on an annual basis. The five areas selected were Seoul, Mokpo, Cheju, Pohang, and Kangnung, which are evenly distributed along the shoreline in Korea. Meteorological fields used in the work were prepared by the Korea Meteorological Administration using the RDAPS(Regional Data Assimilation and Prediction System) with grid spacing of 40 km and 12-h intervals(0000 and 1200 UTC). Upwind regions around the Korean Peninsula were divided into five sectors including the region to the northeast(I), northern China (II), southern China(III), the northwestern Pacific(IV), and Japan(V). The influence of air flow from these sectors on the variations of carbon monoxide concentrations in the selected areas was investigated. The results showed that the influences of Sectors II and III were persistent although some influences of adjacent sectors were observed according to the location of the areas. In general, the concentration of carbon monoxide tended to go up under the influence of Sectors II and III but tended to go down under the influence of Sector I. However, the influences of other sectors were rather mixed. The importance of the long-range transport was examined when the whole country was uniformly influenced by Sectors II and III with strong synoptic winds. The effects of long-range transport were large in Mokpo and Cheju, close to Sectors II and III, where the local emissions were considered small. The effects of local emissions were significant in Pohang and Seoul; such effect was more distinct in Pohang located farther from Sectors II and III.

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A Study on System Engineering of Light Rail Transit Private Investment Projects (경량전철 민간투자사업의 시스템엔지니어링 연구)

  • Cha, Gi-Ho;Park, Jin-Jae;Lee, Jae-Hyeong;Chu, Dong-Su
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.517-544
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    • 2011
  • Promote competition in local government and the construction of a subway construction in the vicious cycle of debt due to the operating deficit as a greater burden on local finances was leave. This government policy of public transport in the center of the metro construction costs affordable and to respond appropriately to public transport demand new transit LRT(Light rail Transit) by introducing the current Busan was the opening of Line 4, yongin line, Busan - Gimhae line, parliamentary and barge construction or ready for the opening. What is light rail, compared to the existing subway and cheaper construction cost, the existing road or bridge that runs along the track is installed, etc. Manless system construction cost and operating expenses as a possible new railway transportation has been a leading state-of-the-art mad. However, the domestic business system engineering of light rail-related companies in the developed countries are doing to advance to the national to the local engineering skills of the self-free, hurry will have to be secured. Therefore, this paper applies local light rail project on the status of the systems engineering analysis and based on this source of the latest engineering technology-intensive systems engineering to provide direction to the development of technology.

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A case study on road traffic accident prevention and opportunity costs by means of local accident investigation (지역 교통사고 원인조사를 통한 사고예방과 기회비용 연구)

  • Jung, Yong-Ki;Choe, Byong-Ho
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.9 no.2
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    • pp.75-86
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    • 2010
  • The objective of this study is to suggest the process and method of local accident investigation for local authorities with a view to efficient and effective managing traffic accidents. With a project city selected accident-type maps, accident lists, accident diagrams, priority of black-spots/-lengths, site visits, remedial measures, opportunity costs, monitoring etc. are taken into consideration, by using accident data in the last 3 years. Analyzed are accident savings to be expected when applying technical, organizational, and administrative processes attached to local accident investigation.

Synergy study on charge transport dynamics in hybrid organic solar cell: Photocurrent mapping and performance analysis under local spectrum

  • Hong, Kai Jeat;Tan, Sin Tee;Chong, Kok-Keong;Lee, Hock Beng;Ginting, Riski Titian;Lim, Fang Sheng;Yap, Chi Chin;Tan, Chun Hui;Chang, Wei Sea;Jumali, Mohammad Hafizuddin Hj
    • Current Applied Physics
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    • v.18 no.12
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    • pp.1564-1570
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    • 2018
  • Charge transport dynamics in ZnO based inverted organic solar cell (IOSC) has been characterized with transient photocurrent spectroscopy and localised photocurrent mapping-atomic force microscopy. The value of maximum exciton generation rate was found to vary from $2.6{\times}10^{27}m^{-3}s^{-1}$ ($J_{sat}=79.7A\;m^{-2}$) to $2.9{\times}10^{27}m^{-3}s^{-1}$ ($J_{sat}=90.8A\;m^{-2}$) for devices with power conversion efficiency ranging from 2.03 to 2.51%. These results suggest that nanorods served as an excellent electron transporting layer that provides efficient charge transport and enhances IOSC device performance. The photovoltaic performance of OSCs with various growth times of ZnO nanorods have been analysed for a comparison between AM1.5G spectrum and local solar spectrum. The simulated PCE of all devices operating under local spectrum exhibited extensive improvement with the gain of 13.3-3.7% in which the ZnO nanorods grown at 15 min possess the highest PCE under local solar with the value of 2.82%.

Role of Ripples, Edges and Defects in Graphene's Transport: a Scanning Gate Microscopy Study

  • Baek, H.W.;Chae, J.S.;Jung, S.Y.;Woo, S.J.;Ha, J.H.;Song, Y.J.;Son, Y.W.;Zhitenev, N.B.;Stroscio, J.A.;Kuk, Y.
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.404-404
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    • 2010
  • Despite much works have been done on the geometric structures of ripples, defects and edge atoms in a graphene device, there has been no report showing the direct correlation between the structures and the transport property. Unlike scanning tunneling microscopy or other electron microscopes, Scanning Gate Microscope (SGM) is a unique microscopic tool with which the local electronic structure and the transport property of a device can be measured simultaneously. We have performed a transport measurement in nanometer scale using a scanning gate microscope (SGM). We have found the nanoscopic pictures of electron and hole puddles and the role of graphene- device edges in the transport measurements. These experimental findings were successfully explained with a theoretical model.

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Assessing the Impact of Locally Produced Aerosol on the Rainwater Composition at the Gosan Background Site in East Asia

  • Han, Yeongcheol;Huh, Youngsook
    • Asian Journal of Atmospheric Environment
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    • v.8 no.2
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    • pp.69-80
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    • 2014
  • It is often assumed that atmospheric observations at remote sites represent long-range transport of airborne material, and local influences are overlooked. We evaluated the impact of local input on the rainwater composition at Gosan Station, a strategic site for monitoring the continental outflow from Asia. We analyzed a 14-year record of rainwater chemical composition archived by the Korea Meteorological Administration and detected local terrestrial contribution for nitrate, sulfate and ammonium. We also measured the chemical composition of rainwater sampled simultaneously at multiple locations within the premises of the Gosan Station, from which local influence with meter-scale spatial heterogeneity could be discerned. We estimate that the local input accounted for at least ~10% of the wet deposition of nitrogen and ~12% of the wet deposition of sulfur during the 14 years. This highlights the significance of the local influence, which should be carefully assessed when interpreting atmospheric observations at this site.

Local Current Distribution in a Ferromagnetic Tunnel Junction Fabricated Using Microwave Excited Plasma Method (마이크로파 여기 프라즈마법으로 제조한 강자성 터널링 접합의 국소전도특성)

  • Yoon, Tae-Sick;Kim, Cheol-Gi;Kim, Chong-Oh;Masakiyo Tsunoda;Migaku Takahashi;Ying Li
    • Journal of the Korean Magnetics Society
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    • v.13 no.2
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    • pp.47-52
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    • 2003
  • Ferromagnetic tunnel junctions were fabricated by dc magnetron sputtering and plasma oxidation process. The local transport properties of the ferromagnetic tunnel junctions were studied using contact-mode Atomic Force Microscopy (AFM) and the local current-voltage analysis. Tunnel junctions with the structure of sub./Ta/Cu/Ta/NiFe/Cu/Mn$\_$75/Ir$\_$25//Co$\_$70/Fe$\_$30//Al-oxide were prepared on thermally oxidized Si wafers. Al-oxide layers were formed with microwave excited plasma using radial line slot antenna (RLSA) for 5 and 7 sec. Kr gas was used as the inert gas mixed with $O_2$ gas for the plasma oxidization. No correlation between topography and current image was observed while they were measured simultaneously. The local current distribution was well identified with the distribution of local barrier height. Assuming the gaussian distribution of the local barrier height, the ferromagnetic tunnel junction with longer oxidation time was well fitted with the experimental results. As contrast, in the case of the shorter time oxidation junction, the current mainly flow through the low barrier height area for its insufficient oxygen. Such leakage current might result in the decrease of tunnel magnetoresistance (TMR) ratio.

A Study on Transport Characteristics of Fe in Soil (토양 내 철의 이동특성에 관한 연구)

  • Cho, Ki-Chul;Lee, Kyeong-Ho;Choung, Young-Heon;Cho, Sang-Won;Oh, Kwang-Joong
    • Journal of Korean Society of Environmental Engineers
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    • v.27 no.10
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    • pp.1043-1051
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    • 2005
  • In this stduy, adsorption and transport characteristics of Fe in the soil were investigated using convection-dispersion local equilibrium sorption model and two-site non-equilibrium sorption model. In batch experiments with different Fe concentration, characteristics of Fe adsorption was investigated using Freundlich and linear isotherm. Column experiments with different flow rate, organic matter content md Fe concentration were also carried out. We measured Fe concentrations in injection-liquid and in effluent, and then applied them to CXTFIT program. As a result of column experiments, some parameters(D, R, ${\beta}$, ${\omega}$) used in two-site non-equilibrium adsorption model were obtained. Characteristics of Fe transport were analyzed using the parameters(D, R, ${\beta}$, ${\omega}$) obtained from the CXTFIT program, Consequently, characteristics of Fe transport in the soil were predicted through two-site non-equilibrium adsorption model.

Some Consideration on the Study of ICAO for the Rome Convention Amendment and the Necessity of Domestic Legislation (로마조약의 개정과 국내입법의 필요성에 관한 소고)

  • Kim, Sun-Ihee;Kwon, Min-Hee
    • The Korean Journal of Air & Space Law and Policy
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    • v.23 no.1
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    • pp.3-32
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    • 2008
  • In proportion to recent developments in aviation technology and growth of the air transport market, the risk of damages to third parties caused by aircrafts and the likelihood of unlawful interference on an aircraft in flight has grown larger. The war risk insurance market was paralyzed by the 9/11 terror event. And if another event on the scale of 9/11 occurs, compensations for third party damages will be impossible. Recognizing the need to modernize the existing legal framework and the absence of a globally accepted authority that deals with third party liability and compensation for catastrophic damage caused by acts of unlawful interference, the ICAO and various countries have discussed a liability and compensation system that can protect both third party victims and the aviation industry for the 7 years. In conclusion, in order to provide adequate protection for victims and the appropriate protection for air transport systems including air carriers, work on modernizing the Rome Convention should be continued and the new Convention should be finalized in the near future. Korea has not ratified the relevant international treaties, i.e. Rome Convention 1933, 1952 and 1978, and has no local laws which regulate the damage caused by aircraft to third parties on land. Consequently, it has to depend on the domestic civil tort laws. Most of the advanced countries in aviation such as the United States, England, Germany, France and even China, have incorporated the International Conventions to their national air law and governed carriers third party liability within their jurisdiction. The Ministry of Justice organized the Special Enactment Committee for Air Transport chapter under Commercial Law. The Air Transport chapter, which currently includes third party liability, is in the process of instituting new legislation. In conclusion, to settle such problems through local law, it is necessary to enact as soon as possible domestic legislation on the civil liability of the air carrier which has been connected with third party liability and aviation insurance.

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Estimation of Freight Trip Generation Rates based on Commodity Flow Survey in Korea

  • Park, Minchoul;Sung, Hongmo;Chung, Sungbong
    • International Journal of Railway
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    • v.5 no.4
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    • pp.139-143
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    • 2012
  • In Korea, almost 700 industrial parks are under operation. Generally, industrial parks consist of national industrial parks and local industrial parks which are managed by a central government and by local governments respectively. The developing countries such as Korea, China and Vietnam etc. have constructed many industrial parks, which result in the change of land use pattern and also affect future trip demands. Therefore, in estimating traffic demands, it is very important to consider the industrial park development. This study aims to improve the methodology in estimating a freight trip generation rate with the data based on a nationwide commodity freight survey. The result showed that it is desirable to apply freight trip generation rate by the industry sector in estimating freight trip generations and using the production area of firm as an indicator. Specially, the reliability of the rates through a survey could be made sure because a sample rate based on firms in industrial parks was over 25% and the response rate was over 67%. The sample rate and response rate are very superior as compared to surveys conducted in many other countries. Because industrial parks have significant effects on forecasting transportation demand in pre-feasibility studies of transport and logistics projects, it is expected that the accuracy of freight trip demands would be improved through the results of this study.