• Journal of Auto-vehicle Safety Association
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• v.13 no.1
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• pp.51-56
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• 2021

As hydrogen is classified as an eco-friendly fuel, vehicles using hydrogen fuel are being developed worldwide. Vehicle fuel hydrogen is stored in cylinders at 70 MPa, so there is a high risk of explosion. Therefore, it is important to inspect hydrogen cylinders in used-vehicles. This study was conducted to improve the inspection method of the cylinders currently mounted on used-hydrogen buses. The inspection method is an image analysis method using a camera. Calcaulation algorithm was developed to quantitatively chech the amount of hydrogen leakage by the image method. As a result of adding a contact angle element to the calculation algorithm suggested by the GTR regulation and comparing it with the experimental data of the GTR regulation, the algorithm reliability was 94%, which secured similarity.

• Journal of the Korean Society of Safety
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• v.14 no.3
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• pp.54-62
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• 1999

This paper presents a study on the safety assessment of human body for electromagnetic field at unbalanced power system. The 3-phase load flow algorithm uses Newton-Raphson method based on Taylor series expansion of power flow equations in rectangular coordinates. The use of such a method can result in a solution with good convergence characteristics. In the safety assessment of human body, the approach based on fuzzy linguistic variable is employed to overcome the shortcomings resulting from a crisp set concept. The suggested scheme is applied to a 24bus system to validate the usefulness. The results for an unbalanced power system are compared with the results for a balanced power system.

• International Journal of Reliability and Applications
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• v.15 no.2
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• pp.151-161
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• 2014

Recently, the automotive industry has been introduced to ISO 26262 in November 2011 to address the necessity of safety risk from sensor to actuator by providing guidance in the form of requirements and processes. The malfunctioning behaviour of these systems could have significant impact on the safety of humans and/or the environment. Most of the modern automobiles are equipped with embedded electronic systems which include lots of Electronic Controller Units (ECUs), electronic sensors, signals, bus systems and coding. Due to the complex application in electrical, electronics and programmable electronics, the need to carry out detailed safety analyses which focuses on the potential risk of malfunction is crucial for automotive systems. In this paper, the international trends on pre and post introduction of ISO 26262 through publications will be analyzed as well as to take a glimpse in the activities for implementing this standard by the automotive manufacturers. The issues and challenges which have been occurring from implementing this standard also will be highlighted.

• Journal of the Korean Society of Safety
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• v.12 no.2
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• pp.70-79
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• 1997

This paper presents a study on the fuzzy linguistic variable based approach for safety assessment of human body in ELF electromagnetic field considering power system states. To cope with the demand in modern industry, the power system becomes larger in scale, higher in voltage. The advent of high voltage system has increased the relative importance of field effects. The analysis of ELF electromagnetic field based on Quasi-Static Method is introduced while the power system is included to model the expected and/or unexpected uncertainty caused by the load fluctuation and parameter changes. In order to analyze the power system, Monte Carlo simulation method and contingency analysis method are adopted in normal state and alert state, respectively. In the safety assessment of human body, the approach based on fuzzy linguistic variable is employed to overcome the shortcomings resulting from a crisp set concept. The suggested scheme is applied to a sample system(modified IEEE 14 bus system) to validate the usefulness.

• Journal of Auto-vehicle Safety Association
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• v.13 no.2
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• pp.42-49
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• 2021

In this paper, we proposes a study on the derivation of inspection factors for the periodic inspection of large buses equipped with AEBS and LDWS. we investigate the safety evaluation (NCAP) of domestic and foreign vehicles and safety standards for the two functions currently in operation and analyze the evaluation factors, measurement methods and evaluation scenarios and so on. In addition, the test scenario was derived by analyzing the vehicle safety evaluation data already held, Therefore, we use an real large bus and the inspection elements for the periodic inspection were derived.

• Journal of Auto-vehicle Safety Association
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• v.13 no.3
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• pp.78-85
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• 2021

Recently a traffic accident of heavy duty vehicles under the mandatory installation of ADAS (Advanced Driver Assistance System) is often reported in the media. Heavy duty vehicle accidents are normally occurring a high number of passenger's injury. According to report of Insurance Institute for Highway Safety, FCW (Forward Collision Warning) and AEB (Automatic Emergency Braking) were associated with a statistically significant 12% reduction in the rate of police-reportable crashes per vehicle miles traveled, and a significant 41% reduction in the rear-end crash rate of large trucks. Also many countries around the world, including Korea, are studying the effects of ADAS installation on accident reduction. Traffic accident statistics of passenger vehicle for business purpose in TMACS (Traffic safety information Management Complex System in Korea) tends to remarkably reduce the number of deaths due to the accident (2017(211), 2018(170), 2019(139)), but the number of traffic accidents (2017(8,939), 2018(9,181), 2019(10,095)) increases. In this paper, it is introduced a traffic accident case that could lead to high injury traffic accidents by being equipped with AEB in a bus. AEB reduces accidents and damage in general but malfunction of AEB could occur severe accident. Therefore, proper education is required to use AEB system, simply instead of focusing on developing and installing AEB to prevent traffic accidents. Traffic accident of AEB equipped vehicle may arise a new dispute between a driver's fault and vehicle defect. It is highly recommended to regulate an advanced event data recorder system.

• Journal of Korean Society of Transportation
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• v.31 no.4
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• pp.32-46
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• 2013

Because of short length between interchanges, traffic congestion has been caused by a lot of short trip traffic in the urban section of interregional expressway. Also, in case of expressway with Bus Only Lane, bus causes dangerous situation by conflicting between vehicles and buses in order to access from Bus Only Lane to IC. Therefore, this study aims to propose Express Lane applied by Bus Only Lane as a new lane operation in order to efficiently operate and to analyze the effectiveness on constructing Express Lane to the Pangyo-Hannam section in Gyeongbu Expressway. The study analyzes effectiveness by scenario using the micro traffic simulation tool, VISSIM 5.4. For this, the indicators which evaluate construction effect of Express Lane, are used by average delay time, average speed and total travel time. The results of the study showed the best effectiveness when Express Lane installed one, and it represented an ideal traffic condition when long distance trip traffic of the whole traffic is 25% in the study section. Therefore, the construction of Express Lane using Bus Only Lane achieves positive effectiveness on safety and expense aspect as well as uncongested flow.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.3D
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• pp.223-229
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• 2010

The bus transfer system has been extended from Seoul to Gyonggi province to provide better Seoul metropolitan area transit service in September, 2008. Moreover, the curved bus routes, except existing rapid bus routes, which cause longer travel time have been straightened out. Also, the Skip Stop operation suggested by passengers has been introduced to main stops in the newly added express bus lines. This study surveyed passengers service satisfaction for the recent adopted bus policies such as the transfer discount system and the express bus system in Seoul Metropolitan area. The survey results may be important foundation for future strategies for improvement. The survey included questionnaires about the importance and the satisfaction level on both quantitative and qualitative factors. The results were statistically analyzed by the modified IPA (Importance-Performance Analysis). As the result of the survey, the newly adopted services such as fare system, fare discount on transferring, travel time savings and increased number of stops are economically feasible and satisfactory, whereas the accessibility to stops, ventilation and air quality in vehicles are the priorities to be improved. Also, the safety and the information system is in need of improvement.

• IEMEK Journal of Embedded Systems and Applications
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• v.8 no.2
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• pp.69-78
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• 2013

As vehicles become more intelligent for safety and convenience of drivers, in-vehicle networking systems such as controller are network (CAN) have been widely used due to increasing number of electronic control unit (ECU). Recently, FlexRay was developed to replace CAN protocol in chassis networking systems, to remedy the shortage of transmission capacity and unsatisfactory real-time transmission delay of conventional CAN. However, it is difficult for vehicle network designers to calculate platform configuration registers (PCR) and determine a base cycle or slot length of FlexRay. To assist vehicle network designers for designing FlexRay cluster, this paper presents automatic field bus exchange format (FIBEX) generation algorithm from CANdb information, which is de-facto standard database format for CAN. To design this program, structures of FIBEX, CANdb and relationship among PCR variables are analyzed.

• The Journal of Sustainable Design and Educational Environment Research
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• v.12 no.3
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• pp.36-49
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• 2013

Unplanned growth of the city was established, despite many elementary, School facilities outside the city is still lacking. Basically should be able to walk to school through elementary school in the case of excessive distance, issues such as unsafe in the school environment and the school, overcrowding, excessive relieve classroom learning environment, with the improvement of the overall situation is necessary. In this study, the status for local public elementary school environment, research and analysis, case studies, research, and through community and resolve problems derived as a school bus for the introduction of alternative feasibility analysis.