• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.4A
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• pp.310-315
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• 2002

The Bark Coherence Function (BCF) defies a coherence function within perceptual domain as a new cognition module, robust to linear distortions due to the analog interface of digital mobile system. Our previous experiments have shown the superiority of BCF over current measures. In this paper, a new BCF suitable for VoIP is developed. The unproved BCF is based on the wavelet series expansion that provides good frequency resolution while keeping good time locality. The proposed Wavelet based Bark Coherence function (WBCF) is robust to variable delay often observed in packet-based telephony such as Voice over Internet Protocol (VoIP). We also show that the refinement of time synchronization after signal decomposition can improve the performance of the WBCF. The regression analysis was performed with VoIP speech data. The correlation coefficients and the standard error of estimates computed using the WBCF showed noticeable improvement over the Perceptual Speech Quality Measure (PSQM) that is recommended by ITU-T.

• Speech Sciences
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• v.10 no.4
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• pp.201-219
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• 2003

Background: The perceptual assessment is generally performed by the voice specialist. The objective evaluation is performed in a voice laboratory. Research in voice laboratories has generated a variety of different objective tests and parameters. The perceptual evaluation is one of the most controversial topics in voice research. Review of literature reveals a wide variety of rating scales and reliability data fluctuating from study to study. Unfortunately, there is no widely accepted valid method for classifying voice disorders and assessing outcome after voice treatment. Objectives: The goals of this research were to identify important objective acoustic parameters of vocal quality, and to establish an objective and quantitative correlate of the perceived vocal quality. Materials and Methods : We evaluated the voice analyzed data from 122 dysphonic patients and 20 normal volunteers. A computerized speech lab. 4300B(CSL) was used to carry out the analysis of each voice sample. Results: Three dysphonia severity indices(DSI) were created using discriminant analysis. DSI is based on the weighted combination of the following selected set of acoustic parameters: absolute jitter(Jita in us), smoothed pitch period perturbation (sPPQ in %), amplitude perturbation quotient(APQ in %), soft phonation index(SPI), average fundamental frequency(Fo in Hz), lowest fundamental frequency(Flo in Hz), and smoothed amplitude perturbation quotient(sAPQ in %). The DSI, being the discriminating rule calculated by the logistic regression, consists of three equation based on statistically significant acoustic parameters. Three DSI were created to reflects best the degree of hoarseness as expressed by G from the GRBAS scale. The more positive this DSI is for a patient, the worse the vocal quality. The more it is negative, the better it is. The effect of sex is included implicitly in the DSI-1 and DSI-2, so that a separate DSI-1 and DSI-2 for males and females need not be used. The DSI is objective because no perceptual input is required for its calculation. Conculsion : This research demonstrates that the voice function values calculated from three different multivariate objective dysphonia severity indices are significantly associated with subjective voice assessments. These multivariate objective dysphonia severity indices may be appropriate for use in clinical trials and outcomes research on treatment effectiveness for voice disorders.

• Journal of the Institute of Convergence Signal Processing
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• v.15 no.3
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• pp.91-96
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• 2014

For Sound source direction and separation method, Frequency Domain Binaural Model(FDBM) shows low computational cost and high performance for sound source separation. This method performs sound source orientation and separation by obtaining the Interaural Phase Difference(IPD) and Interaural Level Difference(ILD) in frequency domain. But the problem of reflection occurs in practical environment. To reduce this reflection, a method to simulate the sound localization of a direct sound, to detect the initial arriving sound, to check the direction of the sound, and to separate the sound is presented. Simulation results show that the direction is estimated to lie close within 10% from the sound source and, in the presence of the reflection, the level of the separation of the sound source is improved by higher Coherence and PESQ(Perceptual Evaluation of Speech Quality) and by lower directional damping than those of the existing FDBM. In case of no reflection, the degree of separation was low.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.235-244
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• 2016

Automotive symbols are more widely needed for new, convenient driving devices in automobiles. Good automotive symbols should be detectable, identifiable at first glance, easily learned, recognizable, and produce quick responses after practice. In this paper, a methodology for developing and evaluating automotive symbols is suggested. It includes multiple tests, such as comprehension, perceptual quality, appropriateness, and integrated evaluation. 28 symbols were tested and evaluated by the suggested methodology for convenient driving systems, such as a lane departure warning system (LDWS), cruise control (CCS), and a collision warning system (CWS). Most of the KS R ISO 2575 symbols had higher scores of comprehension, perceptual quality, and appropriateness, but the sunroof and camera symbols had lower scores. Standard symbols with several new functions should be developed. This methodology could be useful for developing and evaluating automotive symbols.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.16 no.1
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• pp.45-53
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• 2006

In this paper, we propose a method for enlarging quantization steps of a QIM watermarking scheme which determines the perceptual quality and robustness of the watermarked images. In general, increasing the quantization steps leads to good robustness but poor perceptual quality of watermarked images and vice versa. However, if we choose the quantization steps considering the expected quantization results as well as the original images, we can increase both robustness and perceptual quality of the watermarked images.

• Journal of Sasang Constitutional Medicine
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• v.4 no.1
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• pp.81-106
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• 1992

The purpose of this study was to find out the causal relationship between perceptual level of stress and health state according to Korean constitutions and to analyze that effect on the Korean constitution's health state. Subjects of this study were 87 out patient department of constitution at Kyung-Hee Oriental Medicine Hospital. Data were collected by using interview with Questionaire during 6 months from Feb. 2 to June 31, 1991. The Measurement tools used by this researcher were Go's The Questionaire of Identify about constitution, Lee's stress scale and Go's modified Cornell Medical Index which were approved it's reliability and validity. All of the questionaires of were used after pre- test. For the purposes of the study, the collected data were analyzed by frequency, t-test, ANOVA and Pearson correlation. And then this research's issue was tested by SAS program's ANCOVA. The findings of this study was summarized as follow. 1. There was significantly differences in stress perceptual level in Korean constitution. (F=9.68, P=.000). The So Em In (小陰人) were higher than the other constitution on stress perceptional level. 2. In health state, there was significantly difference among Korean constitution. (F=6.654, P=.002). Also the So Em In (小陰人) was lower than the other constitution at health state. Therefore, it was considerate that So Em In (小陰人) was higher perceptual level of stress than the other constitution and the resulting poor health state. 3. Stressful perception was effected on the health state, as a result inverted correlation was constructed between stress perception and health state. (r=-.6034, P=.0001) 4. After exclusion of stress perceptual level, each of the Korean Constitution's health state was not difference (F=1.01, P=.37). It was mean that differences of the Korean Constitution's perceptual level of stress effected on the health state. Bacause So Em In (小陰人) had higher perceptual level of stress than other constitution (F=9.687, P=.000), in proportion to that one's health state was poor. From the results of this study, it could be concluded that the higher stress perceptual level according to Korean constitution, the poorer health state. Further study in this area needs to be consideration that in order to coping with stress, researcher grope for quality nursing intervention with more accurative assessment about Korean constitution.

• Journal of the Korean Society of Clothing and Textiles
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• v.16 no.2
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• pp.263-275
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• 1992

This study intends to provide strategic positioning of brand image analysed from the view point of perceptual dimensions of clothing consumers. Consumers are segmented on the basis of the attributes of brand image, and in each segment, perceptual map is composed according to multidimensional scaling. The results are as follows; 1. According to the Benefit Segmentation, it is statistically significant that the consumers are divided into 'product-factor oriented group 'and' image-factor oriented group'. 2. From the analysis of perceptual map upon the 'similarity of brand image,'image-factor oriented group 'perceives more differently than 'product-factor oriented group' 3. From the analysis of perceptual map with the evaluation of attributes of brand image, price, promotion and design are significant determinants in 'total consumer group'. In addition, store image is significant determinant in' image-factor oriented group' and quality is significant determinant in' product-factor oriented group'. According to the evaluation of consumers on 8 brands with determining attribute-vector, ranks of brands in each segment are similar in the vector of price and promotion but different in the vector of design between segment groups. 4. From the analysis of perceptual map upon the preference of brand image, the distribution of preference and position of ideal point are different between segment groups. 5. With evaluation of purchase habit, statistically significant differences are found between groups segmented in the degree of importance of attributes, purchasing motive, purchasing time, sources of information and expenses for clothes.

• Fashion & Textile Research Journal
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• v.8 no.1
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• pp.55-63
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• 2006

The purpose of this study examines difference of cunsumer satisfaction by expected selection attribute of wedding dress and bride make-up. It is looking into influencing variables in consumer satisfaction, and is supplying real information to wedding market. The subjects of this study were 241 women getting married within one year of Daegu. The data were analyzed by using frequency, mean, the standard deviation, ANOVA, duncan test, correlation analysis, cross-analysis. Conclusion obtained from the results and discussions of the research are as follows: 1) In the attribution of expected selection according to occupation, blue-collar women are concerned about cost factor but they are low content with the perceptual satisfaction factor. 2) When selecting places for wedding dresses and wedding make-up, in the attribute of expected selection about the number of visiting the shop for wedding dresses and make-up, people who visit over 7 dress shops are highly interested in the appearance fancy degree, advertisements effect factors. But they are concerned with advertisements effect factor, cost factor in the perceptual satisfaction factor about wedding dress. Besides, the more they get chances to visit many dress shops, they are concerned with advertisements, cost factors, and satisfied with both the effect of advertisements and appearance factor degree in the attribution of expected selection about wedding make-up. 3) In the attribution of expected selection about the cost of wedding dresses and make-up, the lower the cost paid, people are interested in price factor. Furthermore, in the attribution of expected selection about the wedding dress and make-up cost, those who spent over 150 million Won are interested in quality, others influence factor, and the case of less than 120~150 million Won, people are highly interested in the appearance fancy degree, advertisements effect factor, and the women are satisfied with the advertisement effect factor in the perceptual satisfaction factor of wedding make-up.

• Journal of Broadcast Engineering
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• v.13 no.5
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• pp.744-751
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• 2008

In this paper, we investigate methods to enhance the perceptual quality of MP3-coded audios. Based on the high frequency reconstruction method by Liu, in the proposed method, we determine adaptively the starting point of high frequency reconstruction. We also present an improved linear estimation method. For high frequency component generation, we compare two methods. One is a replication of low-frequency components and the other is an insertion of additive white Gaussian noise signals. Through subjective tests, we shall show that the proposed method can improve the perceptual quality of MP3-coded audio.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.5
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• pp.80-90
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• 2009

This paper presents objective methods which predict perceptual noise levels caused by refrigerators. Eight home refrigerators are chosen and their noises are recorded in an anechoic-chamber and a real-life apartment. In order to obtain perceptual noise levels of the refrigerators, subjective quality assessment tests were performed by 100 evaluators Then, we compute 5 sound quality metrics (SQM) which reflect psychoacoustics characteristics. Finally, objective assessment model for refrigerator noises is developed by linear combination of SQMs.