• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.6
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• pp.24-35
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• 2016

This paper developed social equity indicators for evaluation of bus networks. This paper divided the social equity is into 4 categories such as horizontal equity, horizontal accessibility, vertical equity, and vertical accessibility and social equity was defined as integrated concept of these individual indicators. A simulation was performed by using the newly developed indicators to the toy network. On the basis of the simulation result, the social equity indicators are significant to the relative comparison for each zone. And, it was proved that optimal bus network alternative could be different depending on inclusion of the social equity indicators. Thus, it enabled to evaluate the bus network, as a public resource, considering not only the economic efficiency but also social equity. This paper suggested evaluation method for bus network considering social equity using indicators newly developed.

• Journal of Korean Society of Transportation
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• v.21 no.4
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• pp.29-44
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• 2003

A balanced evaluation system for a bus route network was proposed for a mid-sized suburban city. The evaluation system consists of 7 criteria-accessibility, riding comfort. transfer rate, directness of route, productivity of operation, regional equity, and minimum requirement of bus fleet - and quantitative indicators representing each of the criteria. The proposed system was applied in Siheung, a suburban city in Seoul Metropolitan Area. Four alternative scenarios of bus route network including the existing one were evaluated. The results showed that the suggested criteria and indicators are acceptable for the evaluation of a bus route network. In order to enhance the proposed evaluation procedure, further studies on the normalization of produced values and weights for each of the indicators are needed.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.407-410
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• 1997

This paper analytically derives the variance of service time of a station in the symmetric IEEE 802.4 token bus network with single access class and finite buffer capacity. This performance measure is represented in terms of the total number of stations, the token hold time, the arrival rate of frames, the service rate, and other parameters. Using computer simulations, presented performance measure is validated.

• Journal of the Korean Society for Precision Engineering
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• v.11 no.4
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• pp.126-137
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• 1994

Performance management of computer networks is intended to improve a given network performance in order for more efficient information exchange between subsystems of an integrated large-scale system. Importance of perfomance management is growing as many functions of the large- scale system depend on the quality of communication services provided by the network. The role of performance management is to manipulate the adjustable protocol parameters on line so that the network can adapt itself to a dynamic environment. This can be divided into two subtasks : performance evaluation to find how changes in protocol parameters affect the network performance and decision making to determine the magnitude and direction of parameter adjustment. This paper is the first part of the two papers focusing on conceptual design, development, and evaluation of performance management for token bus networks. This paper specifically deals with the task of performance evaluation which utilizes the principle of perturbation analysis of discrete event dynamic systems. The developed algorithm can estimate the network performance under a perturbed protocol parameter setting from observations of the network operations under a nominal parameter setting.

• Journal of the Korean Society for Precision Engineering
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• v.11 no.4
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• pp.138-147
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• 1994

Performance management of computer networks is intended to improve a given network performance in order for more efficient information exchange between subsystems of an integrated large-scale system. Improtance of performance management is growing as many function of the large- scale system depend on the quality of communication services provided by the network. The role of performance management is to manipulate the adjustable protocol parameters on line so that the network can adapt itself to a dynamic environment. This can be divided into two subtasks : performance evaluation to find how changes in protocol parameters affect the network performance and decision making to detemine the magnitude and direction of parameter adjustment. This paper is the second part of the two papers focusing on conceptual design, development, and evaluation of performance management for token bus networks. This paper specifically deals with the task of decision making which utilizes the principles of stochastic optimization and learning automata. The developed algorithm can adjuxt four timer settings of a token bus protocol based on the result of performance evaluation. The overall performance management has been evaluated for its efficacy on a network testbed.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.2
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• pp.205-212
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• 2011

The high performance intelligent robots have become to use a lot of sensors, actuators and controllers which are connected via bus-type networks while the point to point connection was widely used in-robot networks of existing robots. The bus topology makes the robot system share data internally and it can also reduce the weight of the robot because of smaller wiring harness. The CAN is one of serial bus communication protocols typically used for in-vehicle networks and now it can also be used for in-robot networks because of its low cost and reliability. A performance evaluation system for this type of networked system is developed to analyze the real-time operation and the reliability of a serial-bus network, and the usefulness of the developed evaluation system is shown by some experiments for a network of many CAN nodes.

• Journal of Navigation and Port Research
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• v.27 no.4
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• pp.479-484
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• 2003

In the case of the feeder bus route choice, it is more desirable to choose the route by treating as a single route linked from origin to destination than the whole network. This study is to establish a concept that frames the feeder bus route choice technique for the change of the existing single bus route or the creation of the new feeder bus route. The concept of the feeder bus route choice technique in this study is not to frame the whole bus network but to frame a single route to a unit O-D pair. So, this study has the assumption that does not consider the waiting and transfer time at the bus stop. This system technique consists of the following phases: I) limitation of the road network examined for the study, ii) enumeration of the appropriate candidate routes by the permissive route length, and iii) determination of the optimum bus route by the route evaluation value.

• Journal of Korean Society of Transportation
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• v.27 no.3
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• pp.49-58
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• 2009

Four alternative plans for the bus network in Daejeon metropolitan city, which have different hierarchical structure, were proposed : Alternative 1 represents a bus network without hierarchical structure, and Alternative 2, 3, and 4 represent bus networks with primary, intermediate, and advanced hierarchical structures, respectively. Efficiency of the alternative plans were evaluated based on the evaluation index including travel time cost, waiting time cost, and transition penalty cost. The travel time cost was decreased as the level of hierarchical structure gets higher until it reaches the extremely high level. As the level of hierarchical structure get higher, the waiting time cost significantly decreased while the transition penalty cost increased. Collectively, a bus network with hierarchical structure was shown to be more efficient than without it in the light of total travel cost. For the bus network with hierarchical structure, total travel cost shows a concave curve, which implies that there exists an optimal level of hierarchical structure in a bus network.

• Journal of Korean Society of Transportation
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• v.23 no.2
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• pp.161-172
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• 2005

This study is to develop Bus Transit Route Analysis and Evaluation Model that can product the quantitative performance measures for Bus Transit Route Network Design. So far, in Korea, there are no so many models that evaluate a variety of other performance measures or service quality that are of concern to both the transit users and operator because of lower-level bus database system and transit route network analysis algorithm's limit. The BTRAEM in this research differ from the previous approach in that the BTRAEM employs a multiple path transit trip assignment model that explicitly considers the transfer and different travel time after boarding. And we develop input-output data structure and quantitative performance measure for the BTRAEM. In the numerical experimental applying BTRAEM to Mandl transit network, We got the meaningful results on performance measure of bus transit route network. In the future, we expect BTRAEM to give a good solution in real transit network.

• Journal of Information Processing Systems
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• v.14 no.1
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• pp.270-279
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• 2018

PCI Express (PCIe) bus, which was only used as an internal I/O bus of a computer system, has expanded its function to outside of a system, with progress of PCIe switching processor. In particular, advanced features of PCIe switching processor enable PCIe bus to serve as an interconnection network as well as connecting external devices. As PCIe switching processors more advanced, it is required to consider the different adapter card architecture. This study developed multipurpose adapter cards by applying an on-board optical module, a latest optical communications element, in order to improve transfer distance and utilization. The performance evaluation confirmed that the new adapter cards with long cable can provide the same bandwidth as that of the existing adapter cards with short copper cable.