• Journal of Korean Society of Transportation
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• v.36 no.1
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• pp.13-22
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• 2018

Buses, one of the representative public transportation modes, are divided into a vareity of service types according to the purpose of operation, operating distance, and management agencies. Although bus-involved crashes may cause large amount of damage due to the higher number of passengers boarded on a bus, prior research has little focused on crash severity according to bus service types. This study aims to investigate factors influencing crash severity in bus-involved crashes and to present policy implications to reduce crash severity by bus service type. To do this, bus-involved crash data from the Traffic Accident Analysis System (TAAS) during five-year period are used. Ordered probit models for three types of bus service, i.e., city bus, suburban and express buses, and charter buses, are estimated to analyze the factors of accident severity. The results show that there are significant differences of factors affecting crash severity among the types of bus services while speed and road surface influence all the types of buses. In case of local buses, time of day, roadway alignment, and installation of a traffic signal are found to be statistically significant factors. Seat belt and road class have significant effects on injury severity of the intercity and express buses. Chartered buses have time of day, driving experience, seatbelt, traffic signal, and day of week as the significant factors. The results of this study are expected to contribute to the reduction of the crash severity by each bus service type.

• Journal of Auto-vehicle Safety Association
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• v.12 no.1
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• pp.39-45
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• 2020

The express/intercity bus models have been developing for wheelchair users to provide the preferable long-distance travels by the Korean government research. In the previous studies, evaluation method was set up for the wheelchair users' safety and the study for wheelchair occupants' safety was performed under various crash loadings mimic to real accidents, frontal crash, side impact and rollover, etc. This study was focused on the evaluation of occupant behaviors and injuries (head and chest) during vehicle impact loading cases in order to ensure the safety of wheelchair passengers in the bus. The occupant response and belt loading data during the sled FE simulation were compared with those of the sled test. The simulation results showed overall safety tolerances of wheelchair occupants under the severe frontal deceleration, side impact loading based on the FMVSS 214 configuration and bus rollover loading.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.11 no.7
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• pp.267-274
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• 2001

This paper introduces experimental results related to the vibration ride conditions that a korean male subject experienced in the nationwide railway trains and the express bus. Two types of railway train's Saemaulho and Mugunghwaho. and the express bus were chosen to measure how much the whole-body vibrations on the contact area of the back , hip and feet are exposed to the subject. Measured vibration signals were analysed to assess the rife conditions quantitatively and qualitatively. Analysed results are illustrated to unveil how much typical public transportation system in Korea expose whole-body vibration to passengers. Futhermore, the performance evaluation of their seats were carried out to examine their effectiveness in reducing vibration exposure to passengers.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.1100-1104
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• 2001

This paper introduces experimental results related to the vibration ride conditions that a korean male subject experienced in the railway trains and the express bus. Two types of railway train's, Samaulho and Mugunghwaho, and the express bus were chosen to measure how much the whole-body vibrations of the back, hip and feet are exposes to the subject. Measured vibration signals were analysed to assess the ride conditions quantitatively and qualitatively. Analysed results are illustrated to see how much typical public transportation systems in korea expose vibration to passengers.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1735-1740
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• 2007

Communication network in KTX (Korea Train eXpress), the express train system, has to transmit status variables periodically within tens of seconds and real-time control informations which has short reply like status transition or alarm. KTX uses $Tornad^*$ (TOken Ring Network Alsthom Device) network for this purpose. This network can send and receive messages which enable express train applications embedded in intelligence boards to communicate by itself. Layer 1, 2 of $Tornad^*$ is implemented with differential manchester encoding and IEEE 802.4 standard(token bus standard) respectively. To implement layer 1 and 2, we implemented twisted pair modem using FPGA for layer 1 and used MC68824 from Motorola for layer 2. MC68824 bus arbitration and memory controller is implemented using CPLD.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.5
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• pp.181-185
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• 2006

A study to get better vehicle fuel economy is described based on an express bus. The approach is based on using a commercial software vehicle simulation to identify the relative efficiency of each of the vehicle systems, such as the engine hardware, engine software calibration, transmission, cooling system and ancillary drives. The simulation-based approach offers a detailed understanding of which vehicle systems are underperforming and by how much the vehicle fuel economy can be improved if those systems are brought up to best-in-class performance. In this way, the optimum vehicle fuel economy can be provided to the vehicle customer. A further benefit is that the simulation requires only a minimum of vehicle testing for initial validation, with all subsequent field test cycles performed in software, thereby reducing development time and cost for the manufacturer.

• Journal of Korean Society for Quality Management
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• v.33 no.3
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• pp.71-90
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• 2005

New high-speed rail service, the Korea Train Express(KTX), has been beginning service in Korea. We measured the service quality of the Korea Train Express and comparatively analyzed the service quality of domestic flight and express buses which are means of long distance transportation. Furthermore, by using the Kano model, the perception level of the service of customers is not only segmented in groups but also switching barriers are derived. As a result, the customers by group have a difference in the level of their perception. While in both high-speed bullet train service and flights dimensions significantly affect the customer satisfaction and retention excluding a responsiveness dimension, in the Train Express four dimensions(Reliability, Responsiveness, Assurance, Tangibles) with the exception of Empathy which significantly affect the customer satisfaction and retention.

• Proceedings of the IEEK Conference
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• 2003.07b
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• pp.811-814
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• 2003

Today's and tomorrow's processors and I/O devices are demanding much higher I/O bandwidth than PCI 2.3 or PCI-X can deliver and it is time to engineer a new generation of PCI to serve as a standard I/O bus for future generation platforms. According to this demand the PCI SIG proposed PCI Express. This paper describes about the design of PCI Express Behavioral Model. A Behavioral Model enables the designers to test whether the design specifications are met by performing computer simulations rather than experiments on the physical prototype. In the proposed Model, we can verify whether our design concept satisfies the PCI Express functional protocol.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.04a
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• pp.51-54
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• 2016

NTB는 transparent bridge와 공통적으로 독립적인 PCI bus(PCI 또는 PCI Express bus)에 대해서 데이터 전송 경로(path)를 제공한다는 점에서 기능적으로 유사하다. 그러나, NTB와 transparent bridge 간의 가장 큰 차이점은 NTB가 사용될 경우에 bridge의 하향부분(downstream side)에 위치한 장치들은 상향부분(upstream side)에서는 보이지 않는다는 점이다. 이는 bridge의 하향부분(downstream side)에 위치한 인텔리전트(intelligent)한 제어기(예를들면 CPU를 포함하는 컴퓨터)가 자신의 downstream side에 위치하는 서브시스템 내 각종 장치들을 독립적으로 관리할 수 있다는 점이다. NTB는 또한 첫 번째 호스트(primary host)의 PCI bus로 구성된 서브시스템(subsystem) 계층구조(hierarchy)에 두 번째 호스트(secondary host)를 연결하는 데 사용될 수 있다. 이는 두 시스템간 통신을 가능하도록 하는 반면, 두 시스템을 서로 격리시키는 효과도 발생한다. 즉, NTB는 일반적으로 도어벨(doorbell)을 통해서 bridge의 다른 편에 위치한 장치에 대해서 인터럽트를 보낼 수 있으며, 또한, scratchpad 레지스터를 보유하고 있어 bridge의 양측에서 데이터를 상호 공유함으로써 interprocessor communication 할 수 있다.

• Transportation Technology and Policy
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• v.7 no.2
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• pp.85-94
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• 2010