• The Transactions of the Korean Institute of Electrical Engineers D
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• v.49 no.12
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• pp.675-682
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• 2000

When a system is composed of multi-boards, an efficient bus arbitration method for the data transfer bus must be provided for guaranteeing proper operations. In this paper, a new test methodology is developed which is used for testing on-line bus arbitration. In the new test methodology, events that are occurred during bus arbitration are defined, and expected signals during fault-free bus arbitration are compared with the signals captured during on-line bus arbitration using boundary-scan cells. For this, a new test architecture is proposed which is efficient for the maintenance and the repair of multi-board systems. In addition, the new methodology can be used with off-line interconnect test using boundary-scan.

• Journal of radiological science and technology
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• v.7 no.1
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• pp.13-21
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• 1984

Subtraction is an essential technic to improve imaging quality in various radiological procedures. The limitations of subtraction, however, are well known. Blurred under-subtraction (BUS) method has been suggested to overcome and compensate these limitations. Ten cases of angiography were subtracted by conventional subtraction and BUS technic. Results of this study revealed that BUS method is simple to perform and imaging quality obtained by BUS is excellent. Comparing to conventional subtraction, BUS method has advantages. For example, BUS need no mask film or no immobilization of patient during examination. Improvement of imaging Qualify is achieved by edge enhancement, homogeneous blurring of background density and increasing contrast. With emphasis of its simplicity in technic, we would report that BUS method is a useful adjunct imaging technic in various radiological procedures.

• Journal of Auto-vehicle Safety Association
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• v.12 no.4
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• pp.54-60
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• 2020

In a previous study, an investigation of occupant behaviors and injuries (to the head and chest) was performed during vehicle impact loading cases in order to ensure the safety of wheelchair passengers on a bus. The computational results showed overall safety tolerances of wheelchair occupants under different accident configurations. The bus crashworthiness is described as the capability of a bus to protect occupants during rollover loadings. The residual space containing occupants should be undamaged without any intrusions. However it is necessary to evaluate the residual space according to the bus occupant kinematic analysis under the rollover crash simulation. This study focuses on the evaluation of occupant behaviors during rollover loading cases in order to ensure the safety of bus passengers sitting in general seats and wheelchairs and evaluates the residual space of the bus by analyzing the bus occupant kinematics.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.2
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• pp.1-9
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• 2012

This study proposed a method to determine the number and location of bus information terminals (BIT), which is a device to provide passengers with bus arrival time at bus stops in a Bus Information System (BIS). In low-density area, it is not efficient to survey bus demands such as the number of passengers at all bus stops due to time and cost. This kind of a survey would, however, competently cover all bus stops if performed inside the bus. The number of riding-on and -off passengers is observed for every bus stop, and this data collection is repeated over all day. Data obtained from the survey are aggregated each bus stop. This study defines Utility Index (UI), an aggregate each bus stop. Bus stops are ranked according to UI and determined for a BIT within budget limitation. As a case study, a bus line in Jeju island, Korea, was dealt with. This case showed that the more aggregate the better data quality. This study is expected to contribute to solving a location problem of BITs in a BIS.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.1D
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• pp.1-9
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• 2009

Bus information system(BIS), as a part of the intelligent transportation system(ITS), is one of the most advanced public transportation systems which provide the real-time bus traffic information for the users waiting the buses at the bus stop. However, correct bus information data, such as the present bus location, the user waiting time, the bus arrival time, etc. are not provided for the bus users because the proper bus arrival time predictive models are not used yet in most of the cities operating the bus information system, including the metropolitan City of Ulsan. Thus, the purpose in this study is to investigate real-time bus traffic characteristic data for identifying the bus operation characteristics on the arterial under the study in the metropolitan City of Ulsan, analyze real-time bus traffic characteristic data on the ID locations of the arterial under the study, construct the optimal unit segment models for the unit segments which are the bus stop, node and travel section using the exponential smoothing, weighted smoothing and Kalman Filter methods, respectively, and finally suggest the optimal integrated model for predicting the real-time bus arrival time at the bus stop of the arterial under the study.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.2D
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• pp.217-225
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• 2008

Bus stop is necessary to improve user-focused environment to offer convenient service because of the large number of passengers. This study is to analyze user's evaluation and establishment model of the service levels at bus stop using GAP analysis, IPA and Structural equation model and suggests improvement direction of bus stop. In the GAP analysis, on thirty-one service items of bus stop, the difference appeared highly from the items such as obstacle's facility and the information related to the using bus. In the current IPA service bus operation information, cadence facility and obstacle support facility need to be improved. And in service expectation bus operation information and th exchange facility, the obstacle support facility need to be improved continuously. The evaluation model of bus stop service due to a structure equation's was fitted well by structure equation. In overall satisfaction on bus stop, the waiting satisfaction is more affect the satisfaction of bus use facility. Satisfaction in bus use facility, the related information of bus operation, cadence facility, bus operation information and trans facility, obstacle support facility is more affect compare to other items. The lower overall satisfaction in bus stop is the higher the expectation of overall satisfaction is. Therefore, the information of bus operation and the support facility for the handicapped needs an active improvement plan than ever.

• Journal of Korean Society of Transportation
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• v.23 no.8 s.86
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• pp.129-138
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• 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.

• Journal of Korean Society of Transportation
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• v.28 no.6
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• pp.85-97
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• 2010

The present study aims at estimating the model of bus bunching duration along with its influential determinants in an attempt to understand the status of bus bunching being created by buses from various routes converging into one bus stop. To do so, the duration analysis, a well-known survival analysis, was adopted in order to capture the distribution of duration time as for 8 base lines, accordingly developing the model best fit for weibull distribution. Key attention to draw out the duration time model for bus bunching phenomena was laid, by analyzing 18 impact factors, on such criterion variables as number of berth, number of bus line in each berth and maximum capacity of on-and-off passengers in each line. Comparison in two typical types of bus lane was made between bus-only center lane(Dobong Mia-ro) and normal street-side lane(Tongil Euiju-ro). In this regard, the study, based on the model as above, suggested appropriate alternatives to improve the bus operation by effectively controlling bus bunching.

• 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.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.9
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• pp.50-57
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• 2011

Conventional bus system architectures are composed of several components such as master, arbiter, decoder and slave modules. The arbiter plays a role in bus arbitration according to the selected arbitration method, since several masters cannot use the bus concurrently. Typical priority strategies used in high performance arbiters include static priority, round robin, TDMA and lottery. Typical arbitration algorithms always consider the bus priority primarily, while the bus utilization is always ignored. In this paper, we propose an arbitration method using bus utilization for the operating block of each master. We verify the performance compared with the other arbitration methods through the TLM(Transaction Level Model). Based on the performance verification, the conventional fixed priority and round-robin arbitration methods cannot set the bus utilization. Whereas, in the case of the conventional TDMA and lottery arbitration methods, more than 100,000 cycles of bus utilization can be set by the user, exhibiting differences of actual bus utilization up to 50% and 70%, respectively. On the other hand, we confirm that for the proposed arbitration method, the matched bus utilization set by the user was above 99% using approximately 1,000 cycles.