• Journal of the Korean Society for Railway
• /
• v.12 no.3
• /
• pp.329-334
• /
• 2009

Subway is used as a useful transportation method to solve the metropolitan traffic problem for its advantages of being not only accurate, safe and massive, but also of not producing any exhaustion gas in compare with the other ground transportation systems. However, noise inside the car due to concrete based rail track and tunnel structure has become a social problem. So, an analysis on the noise characteristics according to their routes and locations was made on the basis of the actually measured results from the trial run. To reduce the interior noise of subway train, the side part of rolling stock should have a noise blocking system fur low band frequency noise, the floor of it should have that for medium range frequency noise and the side part as well as lower part of it should have good noise reduction and absorption function.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.19 no.10
• /
• pp.1083-1091
• /
• 2009

Modern military equipments are tend to be mounted on a movable truck for their survivability and operation performance. Special units and electronic equipments installed on the truck experience the vibration caused by road roughness during their transport. The level of the transportation vibration is affected by both road conditions and vehicle speeds. In this paper, various experiments on the vibration characteristics of the equipment are carried out via road tests. Transportation vibration is also investigated by numerical analysis using FEM, and natural frequencies and random responses of the launcher are obtained. The PSD and RMS values of acceleration of the equipment are predicted and compared with test results.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2002.11a
• /
• pp.330.2-330
• /
• 2002

It is conducted to analyze vibration loads on KSR-III and its major segments during their ground transportation and various handling process. These loads may be different from the real flight environment. Inadequate assessment of these loads can cause not only local damages on the rocket system but also the critical problem like flight mission failure. Therefore, transportation and handling loads must be considered during design and attenuated to ensure that the rocket structural damage does not occur. (omitted)

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.11 no.3
• /
• pp.116-121
• /
• 2012

In recent years, world is faced with a transportation energy dilemma, and the transportation is dependent on a single fuel - petroleum. However, Hybrid Electric Vehicle(HEV) technology holds more advantages to reduce the demand for petroleum in the transportation by efficiency improvements of petroleum consumption. Therefore, there is a trend that lower gear noise levels are demanded in HEV for drivers to avoid annoyance and fatigue during operation. And meshing transmission error(T.E.) is the excitation that leads to the tonal noise known as gear whine, and radiated gear whine is also the dominant source of noise in the whole gearbox. This paper presents a method for the analysis of gear tooth profile and lead modification, and the predictions of transmission error and load distribution are shown under one loaded torque for the 1st gear pair of HEV gearbox. The test is also obtained before tooth micro-modification under the torque. At last, the appropriate tooth modification is used to minimize the transmission error and load distribution under the loaded torque. It is a good approach which the simulated result is used to improve the design in order to minimize the radiation gear whine noise.

• Transportation Technology and Policy
• /
• v.13 no.3
• /
• pp.51-55
• /
• 2016

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.20 no.5
• /
• pp.130-145
• /
• 2021

As part of the Smart Seoul policy, the importance of using big urban data is being highlighted. Furthermore interest in the impact of transportation-related urban environmental factors such as PM10 and noise on citizen's quality of life is steadily increasing. This study established the integrated DB by matching IoT big data with transportation data, including traffic volume and speed in the microscopic Spatio-temporal scope. This data analyzed the impact of a spatial unit in the road-effect zone on environmental risk level. In addition, spatial units with similar characteristics of road traffic and environmental factors were clustered. The results of this study can provide the basis for systematically establishing environmental risk management of urban spatial units such as PM10 or PM2.5 hot-spot and noise hot-spot.

• Proceedings of the KOR-KST Conference
• /
• 2007.02a
• /
• pp.259-266
• /
• 2007

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2000.06a
• /
• pp.1018-1024
• /
• 2000

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2012.04a
• /
• pp.801-802
• /
• 2012

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2012.04a
• /
• pp.408-409
• /
• 2012