• Journal of Korea Multimedia Society
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• v.21 no.10
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• pp.1203-1210
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• 2018

As the use of public transportation is increasing, a service considering the convenience of passengers is being launched utilizing the Internet (IoT) data collected through the bus information system. However, the bus information system only provides limited information such as the current location of the bus (GPS) and the expected arrival time at the stop. Additional IoT sensor information is needed to provide various services for the safety and convenience of passengers. In this paper, to improve the safety and convenience of passengers, we have added the boarding doors imaging sensor, temperature and humidity sensors, and sensor for measuring the number of passengers. The proposed IoT bus system can attach various sensors to buses to provide high-quality safety services to passengers.

• Journal of the Korea Society for Simulation
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• v.2 no.1
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• pp.13-22
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• 1993

In a multiple-bus multiprocessor system in which processors and memory modulus are interconnected through system buses, time delay due to bus contention degrades system performance. In order to reduce such a problem , and optimal bus arbitration scheme and its hardware are neccessary. In this study, performaces of four arbitration schemes are analyzed and compared : fixed-priority, equal-priority, rotating-priority and round-robin priority schemes. For the study, the software simulator of a multiple-bus multiprocessor system is developed by using SLAM II. Simulation results show that, when memory sccesses are evenly distributed to all memory modulus, round-robin priority scheme provides the best performance. But when a hot spot exists, the use of the fixed priority scheme results in the shortest access time.

• Journal of Korea Society of Industrial Information Systems
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• v.24 no.4
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• pp.21-28
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• 2019

As ICT technology develops, researches on the construction of communication system for the rapid processing using ICT technology in case of traffic accidents are actively under way. e-Call (Emergency call) is a vehicle ICT-based emergency rescue system that recognizes and reports traffic accidents. On the other hand, the existing bus information system collects the positioning data through the position tracking system mounted on the bus and transmits it to the center, and then provides various services based on the bus information of the collected buses. In this paper, we designed and implemented an emergency rescue system that using the existing bus information system in order to deal with accidents, failures, and emergency situations on public buses quickly.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.2
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• pp.38-44
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• 2009

Bus system consists of several masters, slaves, arbiter and decoder in a bus. Master means the processor that performs data command like CPU, DMA, DSP and slave means the memory that responds the data command like SRAM, SDRAM and register. Furthermore, as multiple masters can't use a bus concurrently, arbiter plays an role in bus arbitration. In compliance with the selection of arbitration method bus system performance can be charged definitely. Fixed priority and round-robin are used in general arbitration method and TDMA and Lottery bus methods are proposed currently as the improved arbitration schemes. In this stuff, we proposed the score arbitration method and composed TLM algorithm. Also we analyze the performance compared with general arbitration methods through simulation. In the future, bus arbitration policy will be developed with the basis of the score arbitration method and improve the performance of bus system.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.9
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• pp.96-102
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• 2008

The SoC bus topology is classified to single and multiple bus systems due to bus number. In single bus system, the selected only one master among the masters that try to initiate the bus transaction can execute its data transaction. On the other hand, in multiple bus system, as several buses that can be operated independently are connected with bridge, multiple data can be transferred parallel in each bus. However, In the case of data communication from one bus system to the other, data latency has remarkably increased in multiple bus. Furthermore, the performance of multiple bus can be easily different from master number, slave type and so on. In this paper, the performance of single and multiple bus architecture is compared and quantitatively analysed with the variation of master number and slave type especially a tying SDRAM, SRAM and register with TLM simulation method.

• Journal of Korean Society of Transportation
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• v.20 no.5
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• pp.175-181
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• 2002

BIS(Bus arrival Information System) is a system that informs Passengers waiting at bus stops of the bus arrival time of next buses. However, when operating this system, it is not exactly known what type of bus arrival information should be provided. The purpose of this paper is to develop a model of the optimal bus arrival time to be informed for BIS. Analyzing Efficiency in the Seoul's Urban Bus Industry Using Data Envelopment Analysis. Two basic types of bus arrival information can be considered. One is Bus Locations : Where next buses are located and under what situation they are, such as the next bus departed from the previous stop, The other is Expected Arrival Time. Time to the arrivals of next buses. Characteristics of these two types of bus arrival time information provided for passengers waiting at bus stops for BIS are examined. The waiting time of passengers at bus stops is derived as a function of the bus arrival time to be informed. Some basic principles about the optimal bus arrival time to be informed are found. Finally, a case study assuming several simplifications is performed. One of the key findings is that there exists optimal arrival time to be informed other than the average arrival time. The optimal arrival time to be informed should be closer to the average arrival time for small and very large standard deviations and be earlier for certain amounts of standard deviations.

• Journal of Korean Society of Transportation
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• v.23 no.2
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• pp.131-142
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• 2005

Punctuality of bus operation can be defined as "timely operation of buses according to their operation schedules." It tis often considered as one of the important measures of bus operation reliability in evaluating bus operation performance from the viewpoint of bus users. Passenger waiting times are severely influenced by the punctuality of bus operations. However, there exist many situations that predetermined schedules cannot be met. In these cases, other definitions of punctuality should be given. This paper is to develop punctuality indexes of bus operation based on various bus operating situations. Bus operation data sampled from Seoul bus system were analyzed to calculate punctuality indexes for a number of bus routes. Then, bus operation punctuality was characterized by various operating conditions. Several interesting results were obtained and explained.

• Proceedings of the Korea Society of Design Studies Conference
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• 2005.10a
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• pp.82-83
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• 2005

• Journal of Korean Society of Transportation
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• v.23 no.7 s.85
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• pp.63-74
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• 2005

When we introduce the BRT systems, it is very important to decide the operating factors, such as bus-stop locations or headway. If the factors are inappropriate, unessential expenses for the operator and users of the bus line may be caused, and it leads increase of social total cost. So, it is necessary that we consider users' origin and destination of each bus line when we set location of bus-stops and the optimal headway. Meanwhile, Smart Card System was introduced of fare collection for the Public Transportation Reform in Seoul last year. This new card system makes it possible to store up the information about bus operating and passenger's trip link. With these substantial information. we can estimate bus-stop-based O-D table. So, in this thesis, it was studied a systematic methodology to find the optimal location and headway for skip-stop bus system (as a type of first step for BRT). The proposed methodology in this thesis is expected to be useful to effect analysis or setting operating factors for skip-stop bus system in each bus line.

• Archives of design research
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• v.19 no.4 s.66
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• pp.61-70
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• 2006

The functions and roles in the various fields of modern society are changing into the unified and multiplex structure, which is simultaneous and virtual communication environments beyond physical space and time, by the digital IT technology. The urban traffic system is also being intellectualized in order to solve urban traffic problems and convenient services by using digital IT technology. The bus, which is the one of the most common public transportation, are suffering in the decrease of bus service quality and the bus passengers rate because of the development of other public transportation systems such as the subway and electric railway and by rapidly increasing private cars. By recognizing these problems, many domestic and overseas cities are promoting to introduce the Bus Information System (BIS) to improve service quality of buses through the intelligent traffic system. According to the construction of this new information system called the Bus Information System (BIS), the new bus stop configuration system and design plans are being required to solve the existing bus stop information system. Therefore, this research was conducted to suggest an effective BIS configuration system plan and synthetic design goals based on the investigation the problems of the information system and the BIS configuration system for Busan city. Also, this research are conducted the below actions as follows: First, the literature survey was conducted, such as theoretical documents on the bus stop and the Bus Information System(BIS), Also, the design trend of the BIS was examined through domestic and overseas BIS cases studies. Scondly, the problems related to the information system in Busan city bus stops were investigated to investigate the present state and problems of the Bus Information System (BIS). Finally, as a result of this research, the effective BIS configuration system plan and design approach methods of bus stops were proposed for by Busan city based on the above investigation results.