• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.25-28
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• 1988

A speech that play a part of important mediation in the man's conversation is the sound of representation to man's emotion and thought, then voice sound could be verified and identified a speaker's speech by individual property. This study indicates as distribution of pitch in searching for sample number of each pitch with eye in the sound waveform of speaker. We propose the algorithm that judge speaker's emotion state, personality, regional group, age, sex distinction, e.t.c., according to the deviation degree.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2000.11a
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• pp.191-194
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• 2000

In this study, experimental verification of performance of flat speaker has been conducted. The piezofilm (PVDF) actuator has been designed to prevent the distortion of sound and make the frequency response of radiated sound flat. The electrode pattern of piezofilm actuator is optimized to satisfy the design objective. The formulation of design method is based on the coupled finite element and boundary element method and electrode pattern is optimized by genetic algorithm. The flat speaker with optimized piezofilm actuator has been manufactured. The sound pressure level at the distance of 50cm is measured using microphone and compared with the result of numerical simulation.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.13 no.1
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• pp.1-7
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• 2020

Directivity control technology of sound system is a key technology for improving sound quality. Providing a line source rather than a point source in an acoustic system can reduce the effects of attenuation interference at long distances, thereby providing high quality sound. In particular, A line-array speaker system can be used to provide coherent, high-quality sound over long distances. However, high frequencies have shorter wavelengths, so the distance between the speakers of a line array system must be shorter, but there are physical limitations. In this paper, we designed a wave guide and installed it in the speaker's compression driver to solve this problem. We measured and tested various acoustic characteristics to verify the performance of the speaker. As a result, when the line array sound system is constructed using the developed speakers, it is possible to provide a line source in all areas including the treble range, thereby achieving the same effect as a single extended source and providing high quality sound up to far distances.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.3
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• pp.485-492
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• 2017

GMM has been one of the most popular methods for scream sound detection. In the conventional GMM, the whole training data is divided into scream sound and non-scream sound, and the GMM is trained for each of them in the training process. Motivated by the idea that the process of scream sound detection is very similar to that of speaker recognition, the UBM which has been used quite successfully in speaker recognition, is proposed for use in scream sound detection in this study. We could find that UBM shows better performance than the traditional GMM from the experimental results.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.31 no.3
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• pp.220-227
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• 1995

An underwater speaker was designed and used as sound source for thronging shoal of squid in squid angling gear operation. The frequency characteristics of the designed speaker was analyzed experimentally and the thronging response of shoals of squid which may be a key parameter for a new sound catching method, was characterized in audible frequency. The field experiment was carried out in the coast of Cheju Island. The results of this study are summarized as follows; 1. Amplitude response of the speaker shows a maximum in their the frequency of 500Hz. 2. The output waveform distortion is not measured in the frequency range of 250~600Hz. 3. A underwater noise of shoals of squid which were thronged by fish lamp in night appeared the center frequency of 300~400Hz. 4. The shoals of squid shows a thronging response, when a manufactured underwater speaker transmits a intermittent audible sound of 300~400Hz in 10m depth of water.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.909-917
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• 2007

Recently the trend of automobile industry is that IQS evaluation index against a sensitivity quality is increasing. To reduce rattle noise due to speaker sound at low frequencies, it is required the advanced investigation of a package tray panel and a door module panel. This paper optimized the design parameters of package tray panel according to the theoretical background about robust design and suggested the design guideline for resonance avoidance and the reduction of vibrational sensitivity considering the excitation frequency of woofer speaker. In addition, it is suggested the design guideline of a door module panel through the sensitivity analysis in case of the speaker excitation. Finally, the design factor analysis of the quality deviation of a mother-car will make it possible to guarantee the stable characteristics of vehicle vibration in the early stage of vehicle development. These improvements can lead to shortening the time needed to develop better vehicles.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.8
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• pp.673-682
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• 2007

Recently the trend of automobile industry is that IQS evaluation index against a sensitivity quality is increasing. To reduce rattle noise due to speaker sound at low frequencies, it is required the advanced technology analysis process of body structure. This paper optimized the design parameters of package tray panel according to the theoretical background about robust design and suggested the design guideline for resonance avoidance and the reduction of vibrational sensitivity considering the excitation frequency of woofer speaker. And this paper described the design process of a door module panel through the sensitivity analysis in case of the door speaker excitation. Finally, the analysis of the quality deviation using mother car is suggested to guarantee the stable characteristics of vehicle vibration in the early stage of vehicle development. These improvements can lead to shortening the time needed to develop better vehicles.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.4 s.304
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• pp.159-166
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• 2005

This thesis deals with a method to deliver more realistic sound by cancelling the cross-talk which is inherent to the 5.1 channel speaker system. First, the cross-talk cancellation method that eliminates cross-talks on the path from left speaker to right ear and from right speaker to left ear is explained. Then the application and replaying method using the cross-talk cancellation explained here is introduced. The acoustical model for cross-talk cancellation is the free field model This model minimizes distortion of sound. Many experts also make studies on this model. I used the bark scale sound quality compensation based on psycho-acoustic. For the surround channels, band-limited sound quality compensation is performed in the frequency domain.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.33 no.4
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• pp.285-289
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• 1997

A Held experiment was carried out to confirm the effect of underwater sound on the luring of fish school of rudder fish in a set net at the coast of Cheju Island. The effects of the acoustic emission on the luring of fish school were observed at a cage around a set net fishing ground using a manufactured underwater speaker. Underwater sounds that were emitted for the luring of fish school were the pure sounds of which frequency were 300Hz and 400Hz, engine noise and swimming sound. The results of the observation are as follows : 1. The input and output wave forms of a manufactured underwater speaker in water tank were similar to those in measurement frequencies. The result of the observation indicated that it could be used for the purpose of the sound emission in measurement frequencies. 2. The effect of the emitted pure sound of 300Hz, 400Hz was remarkable for the luring of fish school in 2 minutes after the sound emission. The reaction of fish school was more sensitive to the pure sound of 400Hz than 300Hz. 3. The effect of the emitted engine noise was more remarkable than that of the pure sound for 3 minute continuously. On the feeding sound, fish formed a shoal and swimmed, but didn't gather around the underwater speaker. 4. The feeding and swimming sound spectra on rudder Hsh showed similar sound pressure distribution each other, they appeared low sound pressure in frequencies of 200-600Hz.

• Journal of Satellite, Information and Communications
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• v.8 no.4
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• pp.43-46
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• 2013

Active use of images in the same place as the religion according to the height of the screen is determined by the height of the main speakers. This causes the 'sound image mismatch' and 'bass boost' sound like a failure occurs. Front seats are good seats in visual acoustics is a bad place. To minimize these obstacles acoustical speakers to actively apply the front fill needed. Higher sound pressure difference between the main speaker and the distance must be determined in accordance with the appropriate capacity. Actively using the front speakers to the sound image field by implementing the agreement to increase the concentration of sound. The relatively high inflow enhance alto lacking the front seat can be implemented evenly in the frequency response. Column in front of the main seat of the main speakers to supplement the deficiencies can be implemented more comfortable acoustic environment. Front fill speaker needs to be actively introduced, thereby presenting a detailed estimate, is needed.