• 제목/요약/키워드: Transport Management

검색결과 1,495건 처리시간 0.027초

Planning and decommissioning of a disused Theratron- 780 teletherapy machine and the dose assessment methodology for normal and radiological emergency conditions

  • Mohamed M.Elsayed Breky ;Muhammad S. Mansy;A.A. El-Sadek ;Yousif M. Mousa ;Yasser T. Mohamed
    • Nuclear Engineering and Technology
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    • 제55권1호
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    • pp.238-247
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    • 2023
  • The present work represents a technical guideline for decommissioning a disused teletherapy machine model Theratron-780 and contains category one 60Co radioactive source. The first section predicts the dose rate from the source in case of normal and radiological emergency situations via FLUKA-MC simulation code. Moreover, the dose assessment for the occupational during the whole process is calculated and compared to the measured values. A suggested cordoned area for safety and security in a radiological emergency is simulated. The second section lists the whole process's technical procedures, including (preview, dismantle, securing, transport and storage) of the disused teletherapy machine. Results show that the maximum obtained accumulated dose for occupational were found to be 24.5 ± 4.9 μSv in the dismantle and securing process in addition to 3.5 ± 1.8 μSv during loading on the transport vehicle and unloading at the storage facility. It was found that the measured accumulated dose for workers is in good agreement with the estimated one by uncertainty not exceeding 5% in normal operating conditions.

수도권 도시철도 경계역을 반영한 교통카드 기반 수입금 배분모형 (Transport Card Based Revenue Allocation Model Considering Boundary Stations in Seoul Metropolitan Urban Railroad Network)

  • 신성일;김희천;남두희
    • 한국ITS학회 논문지
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    • 제22권2호
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    • pp.15-28
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    • 2023
  • 경계역은 수도권 도시철도 연락운임정산에서 반영되지 못한 평가지표이다. 경계역은 동일한 노선을 공유하는 2개 운송기관의 경계 지점에 있는 역사로서 선로 운영방식은 영업관리와 유지관리로 구분된다. 지금까지 연락운임정산은 경계역을 영업관리의 관점으로 평가하였다. 한편 수도권 통합대중교통 요금체계는 발전적 차원에서 경계역을 유지관리의 관점으로 해석할 필요성을 요구하고 있다. 본 연구는 유지관리 방식이 도입되는 상황을 염두에 두고 수입금 변화를 정량적으로 분석하는 방안을 마련하였다. 서울교통공사와 KORAIL의 4개 구간의 경계역을 대상으로하여 1일 교통카드자료를 기반으로 운송기관의 수입금 변화를 평가하였다. 본 연구는 향후 수도권 도시철도의 운송수입금 변화를 평가하고 배분하는 분석적 판단을 위한 기초연구로써 의의가 있다고 할 수 있다.

국내 유해화학물질 운송차량사고 특성분석 (Analysis on the Characteristics of Hazardous Chemical Transport Vehicle Accidents in Korea)

  • 정재욱;이상재
    • 한국재난정보학회 논문집
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    • 제16권2호
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    • pp.310-317
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    • 2020
  • 연구목적: 본 연구에서는 2014년부터 2019년까지 최근 6년간 발생한 화학사고 중 유해화학물질 운송차량사고의 특성을 분석하여, 운송과정에서 발생하는 화학사고를 예방하고자 하였다. 연구방법: 환경부 화학물질종합정보시스템의 통계자료를 활용하여, 운송차량에 의한 화학사고 사고유형, 사고원인, 차량종류로 나누어 조사하였다. 연구결과: 총 506건의 화학사고 중 운송차량에 의한 사고는 105건으로 조사되었으며, 전체 사고의 20% 이상 상회하는 수치를 보였다. 사고유형은 유·누출에 의한 사고가 대부분이었으며, 사고 주요 원인으로는 교통사고와 차량관리소홀이 각각 49건, 29건으로 전체 운송차량사고의 74%이상으로 나타났다. 차량유형별로는 탱크로리(57건, 54%)에서 가장 많이 발생하였으며, 화물트럭(39건, 37%), 트레일러(9건, 9%) 순으로 빈번하게 발생하였다. 결론: 운송차량 사고의 예방을 위해서는 운송차량의 철저한 점검 및 운전자의 안전운행이 요구된다. 또한 정부는 운송차량의 실시간 모니터링을 확대하고, 소관 부처별로 상이한 제도를 통합적으로 관리할 필요성이 있다.

후포해빈에서 해안선의 장기변화 및 전연안표사량의 추정 (Long-Term Shoreline Change and Evaluation of Total Longshore Sediment Transport Rate on Hupo Beach)

  • 박일흠;이영권
    • 한국해양공학회지
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    • 제21권4호
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    • pp.15-20
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    • 2007
  • The harbor siltation by longshore sediment transports has become a serious problem on the East Coast of Korea. A reasonable prediction of the longshore sediment rate is important to approach the siltation problem effectively. In the recently developed 1-line model, the empirical constants of the sediment transport formula, which include the absolute quantity of sediment transport rate and the spatial distribution of breaking wave height by wave deformation, are treated as calibration parameters. Since these constants should be determined by the very long-term shoreline data, the longshore sediment rates are much more reasonable values. The method was applied to Hupo Beach, which has experienced heavy siltation. The authors also discuss long-term shoreline change using aerial photos and the observed wave-induced current patterns. According to the result, the SW-direction sediment transport rate was $146,892m^3/year$, and the NE direction was $2,694,450m^3/year$ at Hupo Beach for the last 11 years. The siltation in Hupo Harbor might be affected by the NE-direction sediment transport from Hupo Beach.

Factors Affecting Financial Risk: Evidence from Listed Enterprises in Vietnam

  • DANG, Hang Thu;PHAN, Duong Thuy;NGUYEN, Ha Thi;HOANG, Le Hong Thi
    • The Journal of Asian Finance, Economics and Business
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    • 제7권9호
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    • pp.11-18
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    • 2020
  • This paper analyzes factors affecting enterprise's financial risk listed on the Vietnam stock market. The panel data of research sample includes 524 non-financial listed enterprises on the Vietnam stock market for a period of eleven years, from 2009 to 2019. The Generalized Least Square (GLS) is employed to address econometric issues and to improve the accuracy of the regression coefficients. In this research, financial risk is measured by the Alexander Bathory model. Debt structure, Solvency, Profitability, Operational ability, Capital structure are independent variables in the study. Firm Size, firm age, growth rate are control variables. The model results show that in order to prevent and limit financial risk for enterprises listed on the Vietnam Stock Market, attention should be paid to variables reflecting Liability structure ratio, Quick Ratio, Return on Assets, Total asset turnover, Accounts receivable turnover, Net assets ratio and Fixed assets ratio. The empirical results show that there are differences in the impact of these factors on the financial risk in state-owned enterprises and non-state enterprises listed on the Vietnam stock market. The findings of this article are useful for business administrators, helping business managers make the right financial decisions to improve the efficiency of financial risk management in enterprises.

세계 LCC 비즈니스 모델의 전략적 변화 연구 및 국내 LCC 산업 관련 시사점 도출(세계 주요 LCC 사례를 중심으로) (Study on the strategic changes of the world LCC business models and their implications to Korean LCC industry(A Case Study of the world's major LCCs))

  • 김상도;김기웅;최건희
    • 한국항공운항학회지
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    • 제21권3호
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    • pp.55-64
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    • 2013
  • As the price competition between airlines became increasingly intensified, due to increased participation of low-cost carriers in the air transport industry and the continued deregulation of international air transport, each airline has introduced various management techniques for securing international competitiveness and operational efficiency in order to cope with the uncertainty in air transport industry. The world leading LCCs, such as Ryan air, easyJet and Southwest, have changed their traditional business models by increasing operation to primary airports, diversifying operating routes, making strategic alliances with FSCs or other LCCs, increasing the operations on the mid or long distance routes, expanding ancillary revenues, etc. As Korea's air transport industry is confronting with intense competition, our LCCs are requested to adjust to this new challenging situation. As the world leading LCCs did, Korean LCCs are recommended to adopt new business models such as restructuring of the air transport industry through M&A, operating more flexibly in terms of frequency or route, launching of services to primary airports, making strategic alliances with foreign FSCs, developing of 4th or 6th traffic demands, etc.

한국의 자동차 해체·재활용 제도 개선 연구 (A Study for Improving the Vehicle Dismantling and Recycling System of Korea)

  • 류병운
    • 자동차안전학회지
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    • 제8권4호
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    • pp.24-30
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    • 2016
  • In Korea, the Vehicle Dismantler and Recycler industry is supervised by the Ministry of Land, Infrastructure and Transport under the Automobile Management Act. Also, Korean Automotive recycling businesses are supervised by the Minister of Environment under the Resource Recirculation Act. The main concern of the Minister of Environment is how the wastes from Dismantled vehicles will be environmentally removed, stored, treated, recycled or disposed. In 2000, the European Union (EU) adopted the End-of-Life Vehicles Directive (2000/53/EC) which required Members to ensure the collection, treatment and recovery of end-of-life vehicles (ELVs). The Directive, the most tightly regulated and precautionary legal systems, required that the last owner of a vehicle could drop off the ELV at an authorized treatment facility and that the producers of the ELV should pay the cost of the program. The adoption of the ELVs directive has led the development of Automotive Dismantler and Recycler networks to reuse, refurbish, remanufacture, recycle and recover parts and materials embedded in ELVs. Also, the ELVs directive which has had an insignificant impact on Korean manufacturers has strong presence in the European market and has been successfully externalized on them. The Korean manufacturers not only achieve the 85% recycling target set by the ELVs directive but also meet the Extended Producer Responsibility (EPR) which requires manufacturers to contribute dismantling process. In order to improve the Korean vehicle dismantling and recycling system, the Automobile Management Act and the Resource Recirculation Act should be harmonized. Particularly the roles of the Ministry of Land, Infrastructure and Transport and the Minister of Environment should be sharply divided. Like Japan, the ELV management needs to be highly centralized, regulated, and controlled by the ministry specialized in Vehicle, namely the Ministry of Land, Infrastructure and Transport and the sub organizations. Like EU Members, recovery, reuse, and recycling must be distinguished. Recovery is defined as the final productive use of the parts and materials embedded in ELVs, which includes reuse and remanufacture of parts and recycling of the other materials. Dismantling process and reuse and remanufacture of parts must be governed by the Ministry of Land, Infrastructure and Transport. For environmental recycling or disposal of waste materials, such as CFCs, glass and plastic material, and toxic substances, governmental financial support system should be in place.