• Title/Summary/Keyword: transport operator

Search Result 111, Processing Time 0.035 seconds

Importance-Performance Analysis for Improving Demand Response Transport(DRT) System (수요응답형교통(DRT)의 활성화를 위한 중요도-실행도 분석)

  • Jang, Tae Youn;Kim, Jun Sung
    • The Journal of The Korea Institute of Intelligent Transport Systems
    • /
    • v.17 no.3
    • /
    • pp.46-58
    • /
    • 2018
  • DRT should have higher positive benefits to become the public transit than the current backcountry buses having demand deficiency and operation problems. The study examines the factors for activating DRT through importance and performance analysis(IPA) and applies the IPA gap theory to find relationship between the current buses and DRT in the mixed operation area. As a result, the operation area is the urgent improving factor and the next ones are transfer related factors, on-time arrival, safe driving, operation time and vehicles. According to the gap theory to activate DRT and reduce the current bus system, in the case that performance is smaller than importance, the performance of transfer, operating time and area, and vehicles should be up. In the case that performance is higher than importance, the performance of luggage space, vehicle clean, safe driving, operator kindness, transfer, operating elements, and fare should keep going.

Quantum transport of doped rough-edged graphene nanoribbons FET based on TB-NEGF method

  • K.L. Wong;M.W. Chuan;A. Hamzah;S. Rusli;N.E. Alias;S.M. Sultan;C.S. Lim;M.L.P. Tan
    • Advances in nano research
    • /
    • v.17 no.2
    • /
    • pp.137-147
    • /
    • 2024
  • Graphene nanoribbons (GNRs) are considered a promising alternative to graphene for future nanoelectronic applications. However, GNRs-based device modeling is still at an early stage. This research models the electronic properties of n-doped rough-edged 13-armchair graphene nanoribbons (13-AGNRs) and quantum transport properties of n-doped rough-edged 13-armchair graphene nanoribbon field-effect transistors (13-AGNRFETs) at different doping concentrations. Step-up and edge doping are used to incorporate doping within the nanostructure. The numerical real-space nearest-neighbour tight-binding (NNTB) method constructs the Hamiltonian operator matrix, which computes electronic properties, including the sub-band structure and bandgap. Quantum transport properties are subsequently computed using the self-consistent solution of the two-dimensional Poisson and Schrödinger equations within the non-equilibrium Green's function method. The finite difference method solves the Poisson equation, while the successive over-relaxation method speeds up the convergence process. Performance metrics of the device are then computed. The results show that highly doped, rough-edged 13-AGNRs exhibit a lower bandgap. Moreover, n-doped rough-edged 13-AGNRFETs with a channel of higher doping concentration have better gate control and are less affected by leakage current because they demonstrate a higher current ratio and lower off-current. Furthermore, highly n-doped rough-edged 13-AGNRFETs have better channel control and are less affected by the short channel effect due to the lower value of subthreshold swing and drain-induced barrier lowering. The inclusion of dopants enhances the on-current by introducing more charge carriers in the highly n-doped, rough-edged channel. This research highlights the importance of optimizing doping concentrations for enhancing GNRFET-based device performance, making them viable for applications in nanoelectronics.

A Study for Revising Compensation Criteria of Public Service Rail Transport (철도 공익서비스비용 보상기준 개선방안 연구)

  • Lee, Jang-Ho;Lee, Sang-Hoon;Kang, Wook
    • Journal of Korean Society of Transportation
    • /
    • v.26 no.1
    • /
    • pp.65-78
    • /
    • 2008
  • After the railway reform in 2004, Korea National Railroad was divided into two separate organizations. The Korea Railway Network Authority is responsible for the construction of new line. Korea Railroad corporation is a public-owned railway operator. The compensation for the loss of rail operator from the Public Service Obligation(PSO) observance is specified in the Law of Rail Industry Development No.32, No.33. However, it is necessary to revise the compensation criteria of PSO after the actual enforcement of the law for more efficient rail operation. This study aims for revising compensation criteria of PSO. In this study, we suggested a revised compensation criteria. The scope of compensation for the loss of regional line operation was adjusted by new criteria considering the characteristics and the business results of the line. The compensation rate is linked with the actual business results of the line for giving motivation to the rail operator.

The Liability of the Operator for Damage to Third Parties on the Surface Caused by Aircraft (항공기에 의하여 발생된 지상 제3자의 손해에 대한 운항자의 책임)

  • Lee, Kang-Bin
    • The Korean Journal of Air & Space Law and Policy
    • /
    • v.21 no.1
    • /
    • pp.65-95
    • /
    • 2006
  • It is essential that the liability for damage on the surface caused by aircraft be regulated at international level. However, the Rome Convention on Damage Caused by Foreign Aircraft to Third Parties on the Surface of 1952 and the Montreal Protocol of 1978 did not have significant worldwide repercussions since few countries have ratified them. So the Secretariat ofthe ICAO has produced the draft Convention for the modernization of the Rome Convention in 2002 and the Special group has considered the text of the draft Convention so far. The draft Convention contains main issues with regard to the liability system of the operator and the insurability of the risks for damage to third parties on the ground. In order to protect the air transport sector of a country as well as to facilitate speedy recoveries by victims, Work on modernizing the Rome Convention should be continued and the new Convention should be finalized in the near future.

  • PDF

Development of a Self-Travelling Sprayer for a Greenhouse (I) - Self-travelling - (시설원예용 파이프 유도식 무인방제기 개발 (I) - 무인 주행시스템 -)

  • 김태한;장익주;강춘태
    • Journal of Biosystems Engineering
    • /
    • v.24 no.3
    • /
    • pp.209-216
    • /
    • 1999
  • A self-travelling sprayer was developed to avoid the exposure of an operator to agricultural chemicals and exhaust gas, to improve safety and to increase working efficiency during the application and transport work in the greenhouses. This system consists of self-travelling system and the control system for application and safety device. The auto-spray car is equipped with a liquid chemical tank of 80l capacity. The travelling system adopted mechanical steering system which link mechanism of front wheel is guided by guide rollers. The sprayer travels along the guiding pipe which is set on the furrow in the greenhouses. The sprayer stops automatically applying and traveling when the liquid chemical tank becomes empty or when the sprayer reach the turning point. The spray booms swings in a vertical plane. The control system of safety devices controls the automatic stop of the sprayer when there is an obstacle on the traveling path, or when the battery becomes discharged. The auto-spray car traveled smoothly and steadily along the guide pipe during traveling straightly and turning on the ground.

  • PDF

Study of International trend for AUGT(Automated Urban Guided Transport) safe requirements (AUGT 안전요구사항의 국제적 동향 연구)

  • Lee, Hoon-Goo;Choi, Kwon-Hee;Jo, Yong-Gyun;Lee, Young-Ho;Hwang, Hyeon-Chyeol
    • Proceedings of the KIEE Conference
    • /
    • 2009.04a
    • /
    • pp.195-197
    • /
    • 2009
  • It is a proven fact with the opening of the Seoul metro line number 1 in 1974 traffic congestion on the roads has decreased and the efficiency of people transportation in general has greatly been enhanced in the downtown and surrounding areas of Seoul. Even today construction of new subway lines are under way and many more are being planned due to the easy access to stations, short waiting and average travel times, compared with personal vehicles, contributing to the efficiency of the public transportation systems that are linking the downtown areas and also the intercity systems in moving passengers during rush hour and times of special event. Since the labour costs of the train operator in any large city based subway system accounts for a major part of the operating costs per kilometer and to ensure cost efficient operations, especially during non-peak hours, it is necessary to implement an unmanned(auto-driven) subway system. In order to implement such a system it is imperative that the on-board and wayside signalling control systems be fully automated as well. Only through proper examination of safety procedures not only by the AUGT(Automated Urban Guided Transport)system but also by ail the international standards organizations involved can safely and stability be ensured.

  • PDF

Link Budget of WAVE Communication System for a Reliable ITS Service under Highway Environments (고속도로 환경에서 안정적인 ITS서비스를 위한 WAVE 통신 시스템 link budget 분석)

  • Song, Yoo-seung;Yun, Hyun-jeong
    • The Journal of The Korea Institute of Intelligent Transport Systems
    • /
    • v.14 no.4
    • /
    • pp.80-85
    • /
    • 2015
  • The era of intelligent transportation system(ITS) has been arrived by applying information and communication technology(ICT) to the traffic. One of these technological advances is a wireless communication technology for a high speed vehicle to be connected to an infrastructure(V2I). A variety of road traffic safety services and operator comfort services are being developed by means of WAVE(Wireless Access in a Vehicular Environment) based on IEEE802.11p Standard. In this paper, the link budget is analyzed to provide a reliable quality of these ITS services. Log-distance model and two-ray model is employed for the wave propagation path loss model which is adequate for a highway environment. Reliable cell coverage is suggested for ITS services from the link budget.

Study on the separation of large ionic-molecules by electrofiltration (전기여과에 의한 거대이온성 분자체 분리현상연구)

  • Park Young-Gyu
    • Journal of the Korean Electrochemical Society
    • /
    • v.1 no.1
    • /
    • pp.18-23
    • /
    • 1998
  • Theoretical model has been derived in the electrophoretic separation system where an electric potential is applied to the system in the axial direction. The effect of electrophoretic convection in the polymeric media is significantly contributed to separate large ionic-molecules because the conformation of large ionic-molecule quickly orients in the field direction. The dependence of the transport in the polymeric media upon field intensity and molecular size aids in understanding the transport of large ionic-molecule in the system, since the convective velocity of large ionic-molecule is accelerated inside a porous material. The separation of two different large ionic-molecules is predicted with a value of $(Pe_t/Pe_g)$ of individual large ionic-molecule using an operator and the reptation theories.

A Study on the Estimation and Verification of the Availability of the Unmanned Light Railway (무인 경량전철 가용도 산정 및 검증에 관한 연구)

  • Kwon, Sang Don;Song, Bo Young;Lee, Hi Sung
    • Journal of the Korean Society of Safety
    • /
    • v.34 no.1
    • /
    • pp.108-114
    • /
    • 2019
  • Unattended Train operation(UTO) requires higher safety target than other systems, since all train operations are automatic. The system provider to deliver without accident or failure, and the operator to transport passengers without accident by putting all trains supplied, including them, into service. Safety rates without such failures can be represented as indicators of RAMS, among which availability is continuously controllable to achieve the target, with a clear target. Availability is often required by the licensee from the initial stage of the project to demonstrate that the request for proposal (RFP) is usually specified and to maintain separate availability targets at the operational stage. In particular, unlike unmanned operation light rail in complex systems, simple formulas are often presented to facilitate verification at each stage. This paper presents this method of usability calculation in an integrated manner at all levels and analyzes the existing usability values to ensure reliability of the availability formula for integrated use in unmanned light rail systems.

The legal responsibility of the unmanned aircraft operators and insurance (무인항공기 운영자의 법적책임과 보험)

  • Kim, Jong-Bok
    • The Korean Journal of Air & Space Law and Policy
    • /
    • v.33 no.2
    • /
    • pp.367-418
    • /
    • 2018
  • Just as safety is the most important thing in aviation, safety is the most important in the operation of unmanned aircraft (RPA), and safety operation is the most important in the legal responsibility of the operator of the unmanned aircraft. In this thesis, the legal responsibility of the operator of the unmanned aircraft, focusing on the responsibility of the operator of the unmanned aircraft, was discussed in depth with the issue of insurance, which compensates for damages in the event of an accident First of all, the legal responsibility of the operator of the unmanned aircraft was reviewed for the most basic : definition, scope and qualification of the operator of the unmanned aircraft, and the liability of the operator of the Convention On International Civil Aviation, the ICAO Annex, the RPAS Manual, the Rome Convention, other major international treaties and Domestic law such as the Aviation Safety Act. The ICAO requires that unmanned aircraft be operated in such a manner as to minimize hazards to persons, property or other aircraft as a major principle of the operation of unmanned aircraft, which is ultimately equivalent to manned aircraft Considering that most accidents involving unmanned aircrafts fall to the ground, causing damage to third parties' lives or property, this thesis focused on the responsibility of operators under the international treaty, and the responsibility of third parties for air transport by Domestic Commercial Act, as well as the liability for compensation. In relation to the Rome Convention, the Rome Convention 1952 detailed the responsibilities of the operator. Although it has yet to come into effect regarding liability, some EU countries are following the limit of responsibility under the Rome Convention 2009. Korea has yet to sign any Rome Convention, but Commercial Act Part VI Carriage by Air is modeled on the Rome Convention 1978 in terms of compensation. This thesis also looked at security-related responsibilities and the responsibility for privacy infringement. which are most problematic due to the legal responsibilities of operating unmanned aircraft. Concerning insurance, this thesis looked at the trends of mandatory aviation insurance coverage around the world and the corresponding regulatory status of major countries to see the applicability of unmanned aircraft. It also looked at the current clauses of the Domestic Aviation Business Act that make insurance mandatory, and the ultra-light flight equipment insurance policy and problems. In sum, the operator of an unmanned aircraft will be legally responsible for operating the unmanned aircraft safely so that it does not pose a risk to people, property or other aircraft, and there will be adequate compensation in the event of an accident, and legal systems such as insurance systems should be prepared to do so.