• 한국ITS학회:학술대회논문집
• /
• 한국ITS학회 2005년도 제4회 추계학술대회 및 정기총회
• /
• pp.83-88
• /
• 2005

A transportation problem in Korea is a serious issue that has to be solved urgently in the motor era of 15 million vehicles. Recently ITS has been introduced to improve efficiency of the current roads because an excessive budget and a long term construction are needed to build new roads. Therefore the government enacted the law as of ITS and the in architecture. However, these ITS information services were oriented to mainly vehicles and drivers, not public entities such as bus driver, passengers and so on. Nowadays lots of local autonomous city introduced a public transportation information system (PTIS), and providing useful information for the public. For this PTIS, important design issues are to be focused on detecting and tracking technology of moving bus, and a wireless communication link to transmit the location information. This paper presents design models using several wireless communication methods, and an implementation case using a Wireless packet Data communication Network (WDN) to transmit bus location information at Seoul, Korea.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• 제13권8호
• /
• pp.1653-1658
• /
• 2009

SoC(System on a Chip) has several masters, slaves, arbiter and decoder in bus architecture. Master initiates the data transactions like CPU, DMA and DSP and slave responses the data transactions 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, SoC performance can be changed definitely. In this study, we compare the characteristics of various arbitration policies using TLM(Transaction Level Model) method. Fixed priority, round-robin, TDMA and Lottery bus policies are used in general arbitration method. We analyze the merit and demerit of these arbitration policies.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• 제36권12B호
• /
• pp.1548-1555
• /
• 2011

In ultra-deep submicron technology, minimization of propagation delay and power consumption on buses is one of the most important design objectives in system-on-chip (SOC) design. Crosstalk between adjacent wires on the bus may create a significant portion of propagation delay. Elimination or minimization of such faults is crucial to the performance and reliability of SOC designs. Most of the previous works on bus encoding are targeted either to minimize the bus switching or minimize the crosstalk delay, but not both. This paper proposes a new bus encoding scheme which can adaptively select one of functions "invert" and "logic-convert" according the number of bus switching on an encoded 4-bit cluster. This scheme leads to minimization of both crosstalk and bus switching. In experiment result, our proposed encoding technique consumes about 25% less power over the previous, while completely eliminating the crosstalk delay.

• Journal of Korean Society of Transportation
• /
• 제23권8호
• /
• pp.129-138
• /
• 2005

Since Successive introduction of BMS(Bus Management System) into the local governments has been able to collect each bus data on the road and valuate the bus operation by the quantitative index not qualitative index. we need a study on punctuality index for evaluation of service level for bus operation using bus location information. We propose punctuality index for bus operation using time-space diagram and valuate the index by application to real bus data.

• The Journal of the Korea Contents Association
• /
• 제13권8호
• /
• pp.458-465
• /
• 2013

The purpose of this research is possible to reduce cost of management and maintenance to realization of smartphone and using data server network technology instead of GPS. Former wireless bus information system was focused on supply side management structure and national spread thus it needs to establish GPS terminal, Windows CE, Window XP embedded and LCD panels which provide only one way communication of information of public traffic information. Therefore, former system management and maintenance cost are very expansive. This research is not use GPS terminal and other hardware equipment but design and realization using smartphone and data network server. This system also provides low cost of management and maintenance. It is not only service downtown area but also out of town and small and medium-sized cities. This system functionally gets a satisfying result user convenience and satisfaction using function of set-up route map, real-time display, and running statically analysis.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• 제42권12호
• /
• pp.35-44
• /
• 2005

SoC(systnn-on-a-chip) requires high bandwidth system bus for performing multiple functions. Performance of the system is affected by bandwidth of the system bus. In this paper, for efficient management of the bus resource on a SoC platform, we present a latency model of the shared bus organized by multiple layers. Using the latency model, we can analyze latencies of the shared bus on a SoC. Moreover we evaluate a throughput of the bus and compare with needed throughput of the SoC platform including IPs such as MPEG or USB 2.0. And we can use the results as a criteria to find out an optimal bus architecture for the specific SoC design. For verifying accuracy of the proposed model, we compared the latencies with the simulation result from MaxSim tools. As the result of simulation, the accuracy of the IS model for a single layer and multiple layer are over $96\%\;and\;85\%$ respectively.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• 제22권6호
• /
• pp.196-207
• /
• 2023

As part of measures to address the climate crisis, buses are also being converted to electric and hydrogen buses. Local authorities need to prioritize carbon emissions when allocating newly introduced and converted electric and hydrogen buses, and as a method, consider the introduction of Low Emission Bus Zones (LEBZ) to propose the reduction of pollution from specific links. To introduce LEBZ, it is necessary to compare the carbon emissions before and after its implementation, yet there is a shortage of studies that focus solely on buses or analyze the effects of introducing LEBZ to specific links. In this paper, we utilized bus information system data to calculate and compare the effects of introducing LEBZ to bus priority lanes in Jeju. We categorized scenarios into five groups, with scenarios 1 through 4 involving the introduction of LEBZ, and scenario 5 designating cases where LEBZ was not introduced. Comparative results confirmed that in scenarios with LEBZ introduction, the reduction per km reached a maximum of 0.097t per km, whereas in cases without LEBZ, it amounted to 0.022t per km, demonstrating higher efficiency. It underscores the significance of conducting carbon emission calculations and comparing the effects of LEBZ introduction using bus information system data, which can be directly applied by local authorities to make informed and rational decisions.

• Journal of Korean Society of Transportation
• /
• 제28권1호
• /
• pp.125-134
• /
• 2010

It is occurred bus arrival time errors when a bus arrives at a bus stop because of a variety of traffic condition such as traffic signal cycle, the time to get on and off a bus, a bus-only lane and so on. In this paper, bus delay time which is occurred as the result of traffic condition was estimated with Markov Chain process and bus arrival time at each bus stop was predicted with it. As the result of the study, it is confirmed to improve accuracy than the method of bus arrival time prediction with existing method (weighed moving average method) in case predicting bus arrival time using 7 by 7 and 9 by 9 matrixes.

• 한국ITS학회:학술대회논문집
• /
• 한국ITS학회 2006년도 제5회 추계학술대회 및 정기총회
• /
• pp.166-170
• /
• 2006

• Journal of the Korea Institute of Information and Communication Engineering
• /
• 제16권10호
• /
• pp.2261-2266
• /
• 2012

The general bus system architecture consists of masters, slaves, arbiter, decoder and so on in shared bus. As several masters can't use a bus concurrently, arbiter plays an role in bus arbitration. In compliance with the selection of arbitration method, The efficiency of bus usage can be determined. Fixed Priority, Round-Robin, TDMA, Lottery arbitration are studied in conventional arbitration method. In this paper, we draw the performance analysis of Fixed Priority, Round Robin, TDMA and Lottery bus arbitration policies due to the data traffic concentration and propose the methods of performance improvement.