• International journal of advanced smart convergence
• /
• v.8 no.2
• /
• pp.199-203
• /
• 2019

In this paper, we propose the efficient impulsive noise mitigation scheme for power line communication (PLC) systems in smart grid applications. The proposed scheme estimates the channel impulsive noise information of receiver by applying machine learning. Then, the estimated impulsive noise is updated in data base. In the modulator, the impulsive noise which reduces the PLC performance is effectively mitigated through proposed technique. As an impulsive noise model, Middleton Class A interference model was employed. The performance is evaluated in terms of bit error rate (BER). From the simulation results, it is confirmed that the proposed scheme has better BER performance compared to the conventional model. As a result, the proposed noise mitigation improves the signal quality of PLC systems by effectively removing the channel noise. The results of the paper can be applied to PLC systems for smart grid.

• Wind and Structures
• /
• v.17 no.3
• /
• pp.299-315
• /
• 2013

Numerical research on four typical configurations of noise mitigation structures and their characteristics of wind loads are reported in this paper. The turbulence model as well the model parameters, the modeling of the equilibrium atmospheric boundary layer, the mesh discretization etc., were carefully considered in the numerical model to improve the numerical accuracy. Also a numerical validation of one configuration with the wind tunnel test data was made. Through detailed analyses of the wind load characteristics with the inclined part and the wind incidence angle, it was found that the addition of an inclined part to a noise mitigation structure at-grade would affect the mean nett pressure coefficients on the vertical part, and that the extent of this effect depends on the length of the inclined part itself. The magnitudes of the mean nett pressure coefficients for both the vertical part and the inclined part of noise mitigation structure at-grade tended to increase with length of inclined part. Finally, a comparison with the wind load code British/European Standard BS EN 1991-1-4:2005 was made and the envelope of the mean nett pressure coefficients of the noise mitigation structures was given for design purposes. The current research should be helpful to improve current wind codes by providing more reasonable wind pressure coefficients for different configurations of noise mitigation structures.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.25 no.1
• /
• pp.58-64
• /
• 2015

There are a lot of different types of noise from construction site and it depends on construction stage, equipment type and number of operating equipments. The problem is that the almost noise from construction site is high level and some kinds of noise levels are over 100 dB. In addition, if construction site is located in downtown, there are a few options to reduce noise level. Therefore several site mitigation plans were developed to reduce different types of construction noises such as breaker work, gang form and asphalt saw. They were applied in site and evaluated noise reduction performance. The test result of site insertion loss was between 4~8 dB depends on the equipment and type of work.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2014.10a
• /
• pp.490-494
• /
• 2014

There are a lot of different types of noise from construction site and it depends on construction stage, equipment type and number of operating equipments. The problem is almost noise from construction site is high level and some kinds of noise levels are over 100dB. In addition, if construction site is located in downtown, there are a few options to reduce noise level. Therefore several site mitigation plans are developed to reduce different types of construction noises and it is applied in site and evaluated noise reduction performance in this study.

• Journal of the Optical Society of Korea
• /
• v.17 no.6
• /
• pp.467-470
• /
• 2013

We propose a blind feedforward phase noise mitigation method in the time-domain for a coherent optical orthogonal frequency division multiplexing (CO-OFDM) systems. By exploiting the redundancy of the cyclic prefix (CP), the proposed scheme acquires the overall phase noise difference information during an OFDM block and attempts to mitigate the phase noise in the time domain using a linear approximation. The proposed algorithm mitigates common phase error (CPE) and inter-carrier-interference (ICI) due to phase noise simultaneously, improving the system performance, especially when decision-directed equalizers are used. The simulation results demonstrate the effectiveness of the proposed feedforward phase noise mitigation approach in time domain.

• Structural Engineering and Mechanics
• /
• v.72 no.4
• /
• pp.421-432
• /
• 2019

In high-speed railway (HSR) system, the structure-borne noise inside viaduct at low frequency has been extensively investigated for its mitigation as a research hotspot owing to its harm to the nearby residents. This study proposed a novel acoustic optimization method for declining the structure-borne noise in viaduct-like structures by separating the acoustic contribution of each structural component in the measured acoustic field. The structural vibration and related acoustic sourcing, propagation, and radiation characteristics for the viaduct box girder under passing vehicle loading are studied by incorporating Finite Element Method (FEM) with Modal Acoustic Vector (MAV) analysis. Based on the Modal Acoustic Transfer Vector (MATV), the structural vibration mode that contributes maximum to the structure-borne noise shall be hereinafter filtered for the acoustic radiation. With vibration mode shapes, the locations of maximum amplitudes for being ribbed to mitigate the structure-borne noise are then obtained, and the structure-borne noise mitigation performance shall be eventually analyzed regarding to the ribbing conduction. The results demonstrate that the structural vibration and structure-borne noise of the viaduct box girder mainly occupy both in the range within 100 Hz, and the dominant frequency bands both are [31.5, 80] Hz. The peak frequency for the structure-borne noise of the viaduct box girder is mainly caused by $16^{th}$ and $62^{th}$ vibration modes; these two mode shapes mainly reflect the local vibration of the wing plate and top plate. By introducing web plate at the maximum amplitude of main mode shapes that contribute most to the acoustic modal contribution factors, the acoustic pressure peaks at the field-testing points are hereinafter obviously declined, this implies that the structure-borne noise mitigation performance is relatively promising for the viaduct.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.7 no.5
• /
• pp.1166-1179
• /
• 2013

In wireless sensor network (WSN) environments, environmental noises are generated by, for example, small passing animals, crickets chirping or foliage blowing and will interfere target detection if the noises are higher than the sensor threshold value. For accurate tracking by acoustic WSNs, these environmental noises should be filtered out before initiating track. This paper presents the effect of environmental noises on target tracking and proposes a new algorithm for the noise mitigation in acoustic WSNs. We find that our noise mitigation algorithm works well even for targets with sensing range shorter than the sensor separation as well as with longer sensing ranges. It is also found that noise duration at each sensor affects the performance of the algorithm. A detection algorithm is also presented to account for the Doppler effect which is an important consideration for tracking higher-speed ground targets. For tracking, we use the weighted sensor position centroid to represent the target position measurement and use the Kalman filter (KF) for tracking.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2006.05a
• /
• pp.89-101
• /
• 2006

This study is a part of ???A study of the community noise:new guideline and policy' which have three main topics and ten sub-topics. Accordingly this part deals with a transpotation noise specifying road traffic ,railroad and aircraft noise, respectively. At first, the ,roadside traffic noise of whole country in 2004 ,22 major cities of total 29 was exceeded the envionmetal noise standards, 55dB(A) at night time ,therefore 24 milion people ,52.4% of korean, who reside at roadside estimates to be exposured the basic problems of this serious noise polluation comes from:: i)It's very limited noise mitigation measures against to continuously increase the number of automobile yearly. ii) and at beginning of road design, It has been neglect to introduce the anti-noise design and layout of road structural scheme as gadient,cutting and viaduct,embankment and zonning of roadside land-buffer area and also re-designation of noise sensitive areas,etc. Secondly ,concerned with the railroad trafffic noise, a inhabitants who are over the envionmetal noise limits,70dB(A), 65 dB(A) in day and night for 34 locations of mayor cities was exposured of 167,000 and 329,000 respectively. With the development of noise mitigation schemes in line with this study it is likely that noise monitoring system needs new installation as well as common use of noise assessment index with $L_{MAX}\;and\;L_{EQ}$. Lastly,noise complaints of millitary aircraft has been rapidly increasing ,so 2.9%(1.4 minion) person demands a compansation of \2,133 billion complying with their requirements we suggest to minimise the airport noise that is to develop of noise abatement procedure ,to make new noise index, to increase budget for house insulations and also to more increase of those the noise monitoring system and to unify the management etc.

• Journal of Satellite, Information and Communications
• /
• v.11 no.1
• /
• pp.26-31
• /
• 2016

In this paper, we proposed a scheme to mitigate noises based on the EMD scheme for heterogeneous communication systems. Noise-corrupted data can be decomposed into a finite number of IMF components. Using the EMD method, we can mitigate noise with eliminate noise-corrupted IMF components. We proposed iteration stop rule for reduce EMD computation time. Simulation results show that proposed EMD scheme based on proposed algorithm for iteration stop rule efficiently mitigates 3 types of noise and reduces its computational time.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2014.10a
• /
• pp.699-700
• /
• 2014

고속도로에 아스팔트 저소음포장이 시공된 현장의 소음조사를 통하여 저소음 아스팔트 포장의 소음저감효과를 분석하였다. 교통량 및 시공시기에 차이가 있는 세 현장에 대하여 측정 시기를 달리하여 저소음포장의 사용 기간에 따른 소음저감효과의 변화를 분석하였으며, 공동주택의 소음대책을 위해 시공된 현장에서는 세대내에서 실질적인 저감효과에 대해 분석하였다. 이 결과를 토대로 저소음포장을 도로소음 대책수단으로 적용을 검토할 경우 설계자가 고려해야할 사항을 제시하고자 하였다.