• Journal of the Korean Society for Nondestructive Testing
• /
• v.31 no.2
• /
• pp.111-117
• /
• 2011

Vibration monitoring is required for reliable thermosonic testing to decide whether sufficient vibration is achieved in each test for the detection of cracks. From a practical point of view, a cheaper and convenient monitoring method is better for the application to real tests. Therefore, the performance of different sensors for vibration monitoring was investigated and compared in this study to find a convenient and acceptable measurement method for thermosonics. Velocity measured by a laser vibrometer and strain provide an equivalent HI when measured at the same position. The microphone can provide a cheaper vibration monitoring device than the laser and the heating index calculated by a microphone signal shows similar characteristics to that calculated from velocity measured by the laser vibrometer. The microphone frequency response shows that it underestimates high frequency components but it is applicable to practical tests because it gives a conservative value of HI.

• Proceedings of the KIEE Conference
• /
• 2008.09a
• /
• pp.261-262
• /
• 2008

Damaged glass insulator that is utilized the high-speed railroad in domestic try to find the cause. This paper is investigated on the characteristics of alumina cement as the binder of class insulator. The components of glass insulator ore stub(tin), rod(tin), shed(tempered glass), and alumina cement. If composition of alumina cement is not unified, crack of alumina cement generated. As these results, cracked marks of cement is appeared and composition of alumina cement is not unified. Therefore, it is estimated that main element of long-term degradation is a alumina cement.

• Proceedings of the KSR Conference
• /
• 2003.10b
• /
• pp.191-196
• /
• 2003

A wheel chair lift can be useful to make a social integration by expanding the economical and cultural activities through enhancing the mobile areas for the mobility handicapped. This research is about the guide when designing a wheel chair lift which extracted demands of wheel chair riders by the new paradigm of the high-speed railroad and social integration by securing the mobile areas and analysis on the user. Also the basic size was extracted to be applied to the design through analysis on the outer size of wheel chairs and researches on their mobility. The wheel chair lift design guideline was offered by reviewing the current law on wheel chair lifts.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.1347-1350
• /
• 2005

Recently, as the road capacity reaches a limit and environmental problems become serious, there exists a gradual increasing need for railway vehicles that are environment-friendly, punctual, reliable and safe. Accordingly, in addition to conventional railroad vehicles, lots of vehicles are being newly developed. Using the developed installed measurement system, the performance characteristics of railway vehicle could be monitored precisely. After recording the input real time data of each signal from railway vehicle to the network line, we could acquire the needed information through post processing program. We could verify the running performances of railway vehicle using this system. As a result, many latent defects have been found and corrected in the prototype train. The measurement systems have contributed to dramatic reduction of the developing period.

• International Journal of Internet, Broadcasting and Communication
• /
• v.8 no.4
• /
• pp.48-53
• /
• 2016

Noise and vibration pollution is emerging to people in high speed trains. And it is difficult to realization of eco-friendly railway system at noise problem. The railway internal noise is 73dB on average and over 80dB in the loudest section. In order to reduce noise, there are passive methods that are far from noise sources and theother active noise reducion method. In this paper, we propose a method of reduce noise by measure and estimate the noise condition of train environment using Bone-Conduction device. We use an anti-phase waveform for canceling of noise characteristic. With this new system, the noise from surrounding environments can be reduced.

• Proceedings of the KSR Conference
• /
• 2005.05a
• /
• pp.516-521
• /
• 2005

Recently the railway becomes principal transportation on account of the important role in mass transit and commute in urban area. However, rail noise and vibration raise a major problem for the residents living nearby railway track. At that point of view, the effective counterplan for the soundproofing and protection of vibration has to be considered in the process of railway design. Therefore, the reliable computation of load caused by running train on rail is very important to estimate vibration of structure adjacent to railway. In this study, Input identification is used for the calculation of load and vibration, induced by high speed train on rail. The influence of railroad noise and vibration on structure is evaluated using the 3-D Finite element method and the reliability of the evaluation is discussed comparing with the results of the field measurements.

• Proceedings of the KSR Conference
• /
• 2005.05a
• /
• pp.1033-1040
• /
• 2005

There have been significant changes in the Korean railway environment in recent years. First, as the railway restructuring plan, Korea Rail Network Authority and KORAIL were established and commenced their works. Secondly, the opening of the high speed railway has provided a chance of reorganization in the whole operation system of the Korean railway network. These new changed environments require an alternative plan to examine the management system of deficit lines and their stations. This paper is intended to approach to clearly define the concept of deficit rail stations and lines in order to make a contribution to establish a comprehensive rationalization plan in the management environment of railroad. The study proposes some method to categorize their deficit stations and lines by three ways.

• Journal of the Korean Society for Railway
• /
• v.9 no.3 s.34
• /
• pp.298-304
• /
• 2006

An active application of concrete track is being expected for the future constructions of Korean railroad. For the successful concrete track construction and design in earthwork areas, the roadbed behavior should be reasonably estimated using the proper analysis method. In this paper, behaviors of concrete track on the reinforced roadbed constructed with the standard stiffness and depth were estimated thorough numerical analyses and field measurements. A three dimensional finite difference method was employed to model the concrete tracks and subground. The settlement and vertical pressures caused by train load were estimated by the numerical method and compared with the field measurement results. The bearing characteristics of roadbed were presented and the proper method for the analysis of concrete track was proposed.

• Proceedings of the KSR Conference
• /
• 2003.10a
• /
• pp.138-143
• /
• 2003

KHST(Korean High-Speed Train, 350km/h), composed of 7 cars that are 2 power cars, 2 motorized car and 3 trailer cars, has been developed and is under on-line test. To verify hte design requirements about the functions and traction performances of this train, KRRI(Korea Railroad Research Institute) decided to evaluate traction performances of the train during on-line test. For this purpose, such as torque, velocity, voltage and current, must be measured. BRRI has developed the measurement system that can be measured vast and various signals effectively. In this paper, we introduce traction performances of KHST. The traction measurement items are focused on the verification of motor block performances.

• Proceedings of the KSR Conference
• /
• 2007.05a
• /
• pp.369-374
• /
• 2007

An active application of concrete track is being expected for the future construction of Korean railroad. For the successful concrete track construction and design in earthwork areas, the residual settlement should be reasonably estimated using the proper method. The concrete track is extremely vulnerable to the damage of residual settlement. However, at the transition areas such as bridge approach, differential settlement will likely occur due to difference of stiffness, poor drainage and poor ground treatment. The maintenance is very difficult for excessive settlement on existing line, it is need to constrain the residual settlement in step of design. In this paper, it is performed the analysis of the residual settlement measured data, test results and reference to understand the residual settlement behavior of concrete track roadbed