• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.2101-2102
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• 2006

In this paper, a new digital audio watermarking algorithm is presented. The proposed algorithm embeds watermark into audio signal based on human auditory system (HAS). This algorithm is a blind audio watermarking method, which does not require any prior information during watermark extraction process. This algorithm finds watermarking position using time-domain masking effect. First we insert the watermark into wavelet domain, and then we use a back-propagation neural network (BPN) to learn the characteristics of relationship between the watermark and the watermarked audio. Due to the teaming and adaptive capabilities of the BPN, the false recovery of the watermark can be greatly reduced by the trained BPN. Experimental results show that the proposed method has good inaudibility and high robustness to common audio processing attacks.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.4
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• pp.385-391
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• 2007

A class D digital audio amplifier with small size, low cost, and high quality is positively necessary in the multimedia era. Since the digital audio amplifier is based on the PWM signal processing, it is improper to analyze the principle of signal generation using linear system theories. In this paper, a class D digital audio amplifier based ADSM (Advanced Delta-Sigma Modulation) is considered. We first model the digital audio amplifier and then explain the operation principle using variable structure control algorithm. Moreover, the ripple signal generated by the hysteresis in the comparator has a significant effect on the system performance. Thus, we present a method to find the magnitude and the frequency of the ripple signal using describing function. Finally, simulations and experiments are provided to show the validity of the proposed methods.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.6C
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• pp.770-776
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• 2004

The goal of perceptual audio coder is to reduce redundancy and irrelevancy of audio signal based on the concept of masking. Several studies on masking effect reveal that the masking threshold varies as a function of the noise-like or tone-like nature of audio signals. Therefore, tonality of audio signal influences significantly the quality and efficiency of perceptual audio coder In this paper, we propose a new effective algorithm for tonality measure using spectrum energy. Since the proposed algorithm consists of a few transcendental functions and simple operations, it has lower complexity than MPEG psychoacoustic model-II. The proposed algorithm was tested with some audio signals, and DSP implementation showed that the proposed algorithm could be implemented with 3 MIPS. These results illustrate the efficiency of proposed algorithm in both performance and complexity.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.12
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• pp.224-231
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• 2013

Defining the concept of prominent audio content as the most informative audio content from the users' perspective within a given unstructured audio segment, we propose a simple but robust intensity-based attack/release pattern features to detect the prominent audio content. We also propose a web-based annotation procedure to retrieve users' subjective perception and annotated 18 hours of video clips across various genres, such as cartoon, movie, news, etc. The experiments with a linear classification method whose models are trained for speech, music, and sound effect demonstrate promising - but varying across the genres of programs - results (e.g., 86.7% weighted accuracy for speech-oriented talk shows and 49.3% weighted accuracy for {action movies}).

• The Journal of the Acoustical Society of Korea
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• v.15 no.2
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• pp.55-60
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• 1996

This paper describes the subjective assessment of the multi-channel audio quality according to the bitrate changing and evaluates the predistortion effect to avoid the unmasked noise after matrixing/dematrxing process in transmission and regeneration of the multi-channel audio. The simulation is processed by the perceptual coding that is MPEG-2 Audio layer II algorithm. We evaluate the quality improvement about predistortion using or not by 384, 320, 256, 128kbps. As the result of the double blind subjective assessment, 5 Grade-Impairment Scale is scored under minus one to 320kbps and so audio quality is evaluated to be perceptible, but not annoying in 3/2 channel. The effect of the predistortion is improved one level in 128kbps and especially speech test material I better improved than music test materials.

• Journal of Korean Academy of Nursing
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• v.30 no.1
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• pp.98-109
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• 2000

The purpose of this study was to identify the effect on improvement of the Activity of Daily Living (ADL) and decrease the cognitive function and agitation behaviors by reminiscence with audio-visual stimulation for senile dementia. The quasi-experimental design was used in this study. Subjects were 26 with mild senile dementia who were cared for at a Day Care Center for Dementia in Seoul. The data were collected from March to July, 1999. Subjects were divided into three groups : Control Igroup with 10 subjects, reminiscence group(Control II group with 8 subjects), and reminiscence with audio-visual stimulation group(experimental group with 8 subjects). The Control I group got routine care as usual. Control II group participated in reminiscence sessions for one hour a day, five times a week , for a period of 4 weeks. The experimental group participated in reminiscence with audio-visual stimulation sessions for one hour a day, five times a week, for a period of 4 weeks. Instruments of this study were color photography with sound that was developed through an open questionnaire about events, objects, humans in action and animals that 100 Korean elderly over 60 would like to memorize. This was referred from the Sensory Stimuli Package by Namazi and Haynes(1994). The effects of treatment was evaluated through MMSE-K by Kwon & Park(1989). Also the Brief Cognitive Rating Scale(BCRS) by Reisberg et al(1983) for the cognitive function, through Agitation Inventory by Cohen- Mansfield and Colleague(1989) for behavioral response and through the Rapid Disability Rating Scale-2(RDRS-2) by Linn & Linn(1982) for the activity of daily living respectively. Data analysis was done using SPSS for $\chi$2- test, ANOVA, repeated measures ANOVA. The results were as follows : 1. Reminiscence with audio-visual stimulation did not improve cognitive function for senile dementia, but significantly improved verbal expression, the subscale of cognitive function. 2. Reminiscence with audio-visual stimulation reduced agitation behavior of experimental group significantly, but there was no significant difference between groups. 3. Reminiscence with audio-visual stimulation did not significantly effect the activity of daily living after treatment. In conclusion, it was shown that the reminiscence with audio-visual stimulation was an effective therapy to improve verbal expression and to reduce agitation behaviors of senile dementia. Further research with more indepth approach is needed, considering characteristic and level individualized for each senile dementia.

• Journal of Broadcast Engineering
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• v.21 no.6
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• pp.977-985
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• 2016

In this paper, we propose a new method for on-line genre classification using spectrogram and deep neural network. For on-line processing, the proposed method inputs an audio signal for a time period of 1sec and classifies its genre among 3 genres of speech, music, and effect. In order to provide the generality of processing, it uses the spectrogram as a feature vector, instead of MFCC which has been widely used for audio analysis. We measure the performance of genre classification using real TV audio signals, and confirm that the proposed method has better performance than the conventional method for all genres. In particular, it decreases the rate of classification error between music and effect, which often occurs in the conventional method.

• Journal of Korea Multimedia Society
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• v.21 no.9
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• pp.1068-1075
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• 2018

We propose a method for driving loudspeakers from class D audio power amplifiers in current mode, instead of in conventional voltage mode, which was impossible with the feedback circuitry. Unlike analog audio amplifiers, Class D audio power amplifiers have signal delay between the input and output signals, which makes it difficult to apply the feedback circuitry for current-mode driving. The idea of the pre-distortion scheme used for the compensation of the non-linearity of RF power amplifiers is adapted to remedy the impedance variation effect of the loudspeakers for current driving. The method uses the speaker model for the pre-distorter to compensate for the speaker impedance variation with frequency. The simulation and test results confirms the validity of the proposed method.

• Korean Journal of Agricultural Science
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• v.38 no.4
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• pp.731-737
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• 2011

In the modern society, GIS-based decision support system has been used in evaluating environmental issues and changes due to spatial and temporal analysis capabilities of the GIS. However without proper manual of these systems, its desired goals could not be achieved. In this study, audio-visual SWAT tutorial system was developed to evaluate its effectives in learning the SWAT model. Learning effects was analyzed after in-class demonstration and survey. The survey was conducted for $3^{rd}$ grade students with/without audio-visual materials using 30 questionnaires, composed of 3 items for trend of respondent, 5 items for effects of audio-visual materials, and 12 items for effects of with/without manual in learning the model. For group without audio-visual manual, 2.98 out of 5 was obtained and 4.05 out of 5 was obtained for group with audio-visual manual, indicating higher content delivery with audio-visual learning effects. As shown in this study, the audio-visual learning material should be developed and used in various computer-based modeling system.

• Journal of Dental Anesthesia and Pain Medicine
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• v.23 no.6
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• pp.327-335
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• 2023

Background: Pain control is a crucial aspect of pediatric dentistry for patient management. Thermo-mechanical devices (Buzzy^TM Pain Care Labs, USA) work on the concept of vibration and cooling and have shown promising results in pain control during local anesthesia in pediatric dentistry. On the other hand, audio distraction has also been used for pain management. The amount of pain endured is determined by the patient's perception and attentiveness. Thus, if audio function is added to the thermomechanical device it might increase its efficiency. Hence, the present study aimed to compare pain on injection using a thermo-mechanical device with and without audio during inferior alveolar nerve block (IANB) injection in children aged 5-10 years old. Methods: Twenty-eight children aged between 5 and 10 indicated for IANB were included in this randomized study. Children who were undergoing the dental procedure were divided into 2 groups, with 14 children in each group. The study group was the thermo-mechanical device with audio distraction; the control group was the thermo-mechanical device without audio distraction. IANB was administered. Subjective pain evaluation was performed using the Wong-Baker Faces Pain Rating Scale (WBFPR) and objective pain evaluation was done using the Faces, Leg, Activity, Consolability, Cry (FLACC) scale. Results: The outcome depicted a significant reduction in pain on injection for both objective and subjective evaluations in the thermo-mechanical device with an audio distraction group. Conclusions: Less pain on injection was observed, when a thermo-mechanical device was used with audio distraction for IANB procedures.