• Journal of Korea Multimedia Society
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• v.13 no.10
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• pp.1494-1505
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• 2010

A variety of sounds take place in medium and small-sized manufactories producing many kinds of parts in a small quantity with one press. We developed the identification system for the quality of parts using HTM(Hierarchical Temporal Memory)-based sound recognition. HTM is the theory that the operation principle of human brain's neocortex is applied to computer, suggested by Jeff Hopkins. This theory memorizes temporal and spatial patterns hierarchically about the real world, which is known for its cognitive power superior to the previous recognition technologies in many cases. By applying the HTM model to the sound recognition, we developed the identification system for the quality of molding parts. In order to verify its performance we recorded the various sounds at the moment of producing parts in the real factory, constructed the HTM network of sound, and then identified the quality of parts by repeating learning and training. It reveals that this system gets an excellent and accurate results at the noisy factory.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.12
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• pp.1139-1146
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• 2010

The indoor noise of the naval vessel is very important related to the optimum environmental conditions for crews as well as the ability of fighting power of antisubmarine. Especially, sonar equipment room is one of the rooms where require to be silent because the informations of the underwater noise are collected and analyzed in there. In this paper, the sound reduction of the TASS console, one of the main noise sources in a sonar equipment room for a typical naval vessel, is described. The noise source of this TASS console is the flowing noise of cooling fan. In order to reduce this kind of noise, the plenum chamber and acoustic elbow were developed. Related to the development of the plenum chamber, the area of the air-outlet and sound absorption of the inner lining were investigated experimentally with the evaluation system of the sound insertion loss. Acoustic elbow was also manufactured and evaluated with the evaluation system of the sound insertion loss. Finally, in order to evaluated the ability of noise reduction of the plenum chamber and acoustic elbow, the indoor noise of the sonar equipment was measured when they were appled to TASS console.

• The Journal of the Acoustical Society of Korea
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• v.28 no.7
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• pp.653-660
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• 2009

This paper proposes a robust audio watermarking algorithm for copyright protection and improvement of sound quality after embedding a watermark into an original sound. The proposed method computes the FFT (fast Fourier transform) of the original sound signal and divides the spectrum into a subbands. Then, it is necessary to calculate the energy of each subband and sort n subbands in descending order corresponding to its power. After calculating the energy we choose k subbands in sorted order and find p peaks in each selected subbands, and then embed a length m watermark around the p peaks. When the listeners hear the watermarked sound, they do not recognize any distortions. Furthermore, the proposed method is robust as much as Cox's method to MP3 compression, cropping, FFT echo attacks. In addition to this, the experimental results show that the proposed method is generally 10 dB higher than Cox's method in SNR (signal-to-noise ratio) aspect.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.827-828
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• 2012

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.248-249
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• 2012

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.05a
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• pp.240-241
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• 2010

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.63-64
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• 2011

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.606-607
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• 2011

• The Journal of the Korea Contents Association
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• v.8 no.6
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• pp.1-7
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• 2008

The paper is to solve the problem of existing sound system, which has difficulties of system organization and the increase of additional install cost and unfriendly interior. To solve the existing system, we drew the new sound system based on PLC and studied it. A transmitter and a receiver were designed using the PLC chip INT5500CS. Sound system was configured with a CD player that sound signals are sent from the transmitter and a speaker connected to the receiver. For analysis of characteristics of this system, a USBPre external sound card and Smaart Live 5 which is a PC-based sound measuring program were added. As a result of our experiment, the measured signal level is $2{\sim}3$[dB] lower than reference signal, latency is 16.69[ms] and the specific character of coherency is bad in high frequency band. Otherwise, this system transmits and receives signals over 90[%] in good condition as a result of measuring pink noise, frequency(1kHz), and phase, magnitude. In view of the result so far achieved, the system designed our team has excellent performance, it resolves defect of existing audio signal transmition system.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.2
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• pp.106-113
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• 2012

Recently laws have been enacted to build and promote the use of smart grid. There are also increasing demands for the compliance with international trade agreements and the related international standards. Due to these rapid changes in electric power industry and the market expansion, importances of new technologies and processes have been being increased. To reflect these international trends, the government have carried out the designation of new technology for electric power industry to promote domestic industries and national competitiveness by inspiring technology developments in individual or private industry sectors. In this paper analysis of the current status of the designation of the new technology of electric power has been presented including its problem and effect on the related industries. The analysis is expected to be utilized to enhance sound development and to vitalize the electrical new technology regulation.