• Proceedings of the KSR Conference
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• 2003.10b
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• pp.52-57
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• 2003

This study suggests several ways to improve the railroad facilities in the urban areas so as to maintain the urban railroad facilities and minimize their adverse impact on the roads around the facilities. Environmental problems such as noise and vibration can be minimized by constructing soundproofing walls and improving railway and train systems. To reduce the traffic congestion at the railroad crossings, current at-grade crossings should be changed to separated crossings. Moreover, the criteria by where railroad crossings are located should be revised. In the long term, the land use development for the railroad station and the surrounding areas needs to be changed. Several case studies of Japan's and France's major cities show the potential of successfully integrating the development of railroad facilities and their surrounding areas. In addition, there is a need to .consider institutional aspects, to improve the railroad facilities in the urban areas and to allow the integrated development of the railroad facilities and the surrounding areas.

• Journal of Environmental Science International
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• v.21 no.9
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• pp.1053-1058
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• 2012

In this study, soundscape was analyzed through physical measurement and social surveys. The results showed that, soundscape components were related to functional partitions and tourist activities, at the same time influenced by ambient noise. The sound pressure levels showed daily regular changes. Semantic differential analysis showed that the evaluation of the soundscape in urban park was rather complicated. It was still possible to identify major factors including relaxation, spatiality and environment. The results provided theoretical basis for improving urban park soundscape, and called attention to this problem.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2003.10a
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• pp.18-23
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• 2003

The Objective of this research is to find the optimal design of the Noise Reduction Interference Model (NRIM) which is recently invented. Without optimization, the NRIM has been successful to reduce the urban noise induced by trains and automobiles. While it is used with the barrier on the road, there is a strong desire to reduce noise more. Yet the only remedy is to make the barrier higher with cost increase. Therefore, the optimal design is necessary to reduce noise while maintaining the barrier height. More efficient Genetic Algorithm is used to find the optimal shape of NRIM with the reduction of noise lever up to 15 dB. also BEM is used to verify the optimal design results.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.647-650
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• 2001

The traffic noise from automobiles have been causing so serious problems in urban areas that the study and solutions to reduce noise and air pollution have been required. In general, Portland cement concrete(PCC) pavements have the advantage of durability and superior surface friction when compared to most dense-graded asphalt. However, data collected to date generally show PCC pavements to create more noise than asphaltic surfaces. Therefore, recent research has shown some new concrete pavement textures to be worth further examination. Exposed Aggregate Pavements have also been evaluated for noise impacts. This PCC surface is accomplished by brushing the surface of the plastic concrete to expose the aggregate, increasing the macro texture. In this study, in order to manufacture Aggregate Exposed Concrete for low noise pavements, we considered the effects of retarder agents according to dosage and curing conditions. So we tried to find out relationship between textures of surface and effects of retarder.

• The Journal of the Acoustical Society of Korea
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• v.13 no.1
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• pp.57-62
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• 1994

In order to establish a prediction method for road traffic noise generated from actual traffic flow, a new approach is proposed for practical use. One block in urban road is regarded as one box in this study. This prediction method is able to treat any kind of road traffic noise generated from one block. The validity of the proposed prediction method has been experimentally confirmed by applying it to actually observed road traffic noise data. The correlation between observed and predicted noise level is good.

• Smart Structures and Systems
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• v.23 no.4
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• pp.347-357
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• 2019

A new methodology for mitigation of the wheel squealing is proposed and investigated based on the dithering control. The idea can be applied in railway lines particularly in urban areas. The idea is clearly presented, and applied to a validated model. A full-scale model including the vehicle, curved track and wheel/rail contact is developed in the time domain to analyze the possibility and level of wheel squeal noise. Comparing the numerical results with a field test, the model is validated in different levels namely i) occurrence, ii) squealing frequency and iii) noise level. Two different approaches are proposed a) dithering of the wheel with piezoelectric patches and b) dithering of the rail with piezoelectric stacks. The noise level as well as the wheel responses is compared after applying the control strategy. A parametric study is carried out and effect of the dithering voltage and frequency on the squealing noise is investigated. It is found that both the strategies perform quite effectively within the saturating threshold of piezoelectric actuators.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.6
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• pp.103-108
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• 2016

The size of urban areas is currently growing and the functions of cities are becoming increasingly complicated. Furthermore, more people are living in cities. The life of urban is getting closer and linked with neighboring people in many parts. In particular, people are making artificial noise, even though it might not consciously be noticed, in their daily live. Seoul is the most crowded place in Korea and the noise levels are 73dB or higher. People living in cities are exposed to noise pollution. In particular, loudspeakers used during demonstrations or to generate publicity, cause considerable noise, which in turn can be related to stress. Moreover, the noise restrictions defined by law are not adhered to. If enhanced noise regulations, no matter how residents are not forced to be a great stress field close to the noise and reduces the loudness -5dB do not feel well if the difference. Limiting the duration of noise rather than reducing the volume thus is a much more plausible way of reducing the damage caused by noise pollution. If the stress caused by the noise, you will see people or vehicles holding a megaphone at the roadside is not good for health if it may be a wise way to live that is getting rid of the noise pollution so quickly out of the area.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.263-265
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• 2006

The pure electric braking system need to be developed to stop the electric train to zero speed by electricity. This system has advantages like reduction of weight, maintenance cost, noise, and dust generated by disk friction. Therefore, we will study this system for Korean urban transit system.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.6
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• pp.1103-1111
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• 2000

With the rapid industrial development, a railway has become a main traffic means. But, rail traffic noise and vibration have become a major problem in urban area as well as a very serious issue in the living environment. Especially, noise and vibration induced by the rail operation have influenced on the residents' living nearby railway tracks. Nevertheless, adequate guidelines for the railway vibration are not yet established because of the lack of basic data and insufficient research works. In this point, the present study attempt to survey the effect and subjective response of railway vibration in urban area using questionnaire. This study also presents a basic data in establishing effective vibration plans for railway vibration in the future.

• Wind and Structures
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• v.31 no.3
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• pp.185-196
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• 2020

A method to reduce the wind pressure at the leading edge of a noise barrier was investigated by gradually lowering the height of a member added to the end of the noise barrier. The shape of the lowered height of the added member was defined by its length and slope, and the optimal variable was determined in wind tunnel testing via the boundary-layer wind profile. The goal of the optimal shape was to reduce the wind pressure at the leading edge of the noise barrier to the level suggested in the Eurocode and to maintain the base-bending moment of the added member at the same level as the noise-barrier section. Using parametric wind tunnel investigation, an added member with a slope of 1:2 that protruded 1.2 times the height of the noise barrier was proposed. This added member is expected to simplify, or at least minimize, the types of column members required to equidistantly support both added members and noise barriers, which should thereby improve the safety and construction convenience of noise-barrier structures.