• The Journal of Korean Institute of Communications and Information Sciences
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• v.12 no.2
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• pp.148-159
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• 1987

This paper proposes CSMA/CD-TDM/SD(carrier sense multiple access/collision detection-time division multiplexing/silence detection) control scheme in bus type integrated data/voice local area networks. Simulation results show that this control scheme satisfies the lossless real-time constraints of the voice traffic and improves the data throughput-delay characteristics as compared to those of the CSMA/CD/MPD and the CSMA/CD-TDMA.

• Speech Sciences
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• v.14 no.2
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• pp.65-71
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• 2007

The severe-profound hearing impaired children have various disorders in everday communication due to the lack of hearing feedback. Especially, their speech produced unstable voice, omission and distortion of articulation, pitch break, cul-de-sac voice, and so on so that they were difficult to accurately deliver an intended message. This study attempts to analyze the acoustic characteristics of 4 vowel sounds produced by 35 severe-profound hearing impaired children using CSL(Computerized Speech Lab, Model 4300b). The formant data were obtained from the spectrogram and analyzed data by 12 formant filter and auto-correlation among the formants. Results showed that the hearing impaired children's formant values came out very high. They produced the vowels at the mode of hypertension with unstable voice. In order to improve their speech, they would need some adequate auditory feedback.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.11
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• pp.5541-5554
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• 2018

A voice is one of the most significant non-verbal elements for communication. Disorders in vocal organs, or habitual muscular setting for articulatory cause vocal disorders. Therefore, by analyzing the vocal disorders, it is possible to predicate vocal diseases. In this paper, a method of predicting vocal disorders using the jitter, shimmer, and harmonics-to-noise ratio (HNR) extracted from vocal records is proposed. In order to extract jitter, shimmer, and HNR, one-second's voice signals are recorded in 44.1khz. In an experiment, 151 voice records are collected. The collected data set is clustered using cobweb clustering method. 21 classes with 12 leaves are resulted from the data set. According to the semantics of jitter, shimmer, and HNR, the class whose centroid has lowest jitter and shimmer, and highest HNR becomes the normal vocal group. The risk of vocal disorders can be predicted by measuring the distance and direction between the centroids.

• The Journal of the Acoustical Society of Korea
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• v.34 no.1
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• pp.82-91
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• 2015

In this paper, a novel codebook design method for data modem over voice channel is presented. Proposed method searches the symbols which have the maximum probability distribution overlap in the symbol space and minimizes the overlap to improve the symbol error rate via minimax optimization. We present numerical simulations and an example implementation. We also give the results of the experiment tests.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.11 no.4
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• pp.227-236
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• 1986

In this paper, an integrated voice/data packet network with window flow control is modeled by a colsed multichain queueing system, and its performance is analyzed by the mean value analysis method. Particularly, for the analysis of a packet network having various kinds of messages with different priority classes, we introduce an approach based on the mean value analysis and the concept of effective capacity. By the mathematical analysis and computer simulation, we obtain the following network statistics in the steady state: Mean buffer occupancy at each node, utilization of link throughput of a virtual channel, and mean delay time of each message. Our iterative analysis method can predict the link data status in most cases within about 10 percent of accurady, and the statistics of voice messages and external data within 5 percent as compared to simulation results.

• Phonetics and Speech Sciences
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• v.6 no.3
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• pp.41-48
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• 2014

This study investigated the differences between emotional parameters BDI, VHI, STAI-X-I and STAI-X-II according to the menstrual cycles of the female and the relation between changes of the depression index and voice characteristics (jitter, shimmer, CPP, HNR, $pF0{\cdot}F1{\cdot}F2{\cdot}F3$, sF0, sF4, sB1, $H1_{c/u}$, $A1_u$, $A3_c$, $H1A3_{c/u}$, $H1A1_u$). Twenty three females ($30{\pm}4.4$ years old) living in Seoul and Gyeonggi Province were participated in this study to answer the questionnaires and record their voice. The participants prolonged /a/ vowel for 5 seconds in a natural condition for their voice recording. Voice data were analyzed using the Matlab and Praat program. A t-test and a correlation analysis were conducted by using SPSS for the statistical analysis. The results are as follows. First, the BDI is significantly higher in group I (lurear phase contrast the menstrual period) and group II (follicular phase against the menstrual period) than group III (luteal phase for follicular phase) (p<.05). Second, shimmer, CPP, pF0 showed a statistically high correlation regarding the BDI in group I (lurear phase contrast the menstrual period). Voice parameters may be useful as supplement in evaluating the emotional change in the phase of menstrual cycle.

• The Journal of the Korea Contents Association
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• v.12 no.7
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• pp.176-182
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• 2012

Voice Phishing finds out personal information illegally using electrification and it is confidence game that withdraw deposit on the basis of this. It appeared by new social problem as damage instances increase rapidly. Target of the damage is invading indiscriminately to good civilian and is crime that commit by foreigners such as a most Chinese, Formosan. Voice Phishing can be crime type of new form in terms of criminal practice is achieved in the foreign countries. Therefore, this study wishes to analyze present occurrence actual conditions and example, and search effective confrontation plan regarding Voice Phishing. Voice Phishing criminal offense is growing as crime is not eradicated in spite of continuous public relations and control, and technique is diversified and specializes preferably. Hereafter, confrontation plan about problem may have to be readied in banking communication investigation to eradicate Voice Phishing. Also, polices control activity may have to be reinforce through quick investigation's practice and development of investigation technique, and relevant government ministry and international mutual assistance cooperation such as the Interpol should be reinforced because is shown international crime personality.

• Phonetics and Speech Sciences
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• v.2 no.2
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• pp.101-108
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• 2010

An inhaled salbutamol and salmeterol for chronic obstructive pulmonary disease(COPD) and asthma have been used worldwidely. But there has been few study about the voice change evoked from the post-medicine effect. To evaluate the voice influenced of short-acting and long-acting ${\beta}_2$-agonists, two experiments were carried out: one was salbutamol experiment 1 with eight patients, the other was salmeterol experiment 2 with six patients. Experiment 1 was made of two stages: premedication & postmedication. Experiment 2 was four stages: stageI was premedication, stageII was postmedication & pregaggling, stageIII was postmedication & postgaggling(100 ml with water), and stageIV was postmedication & 30 minutes later. Measured parameters were F0, F0_SD, Jitter_rap, Shimmer_apq11, HNR, BW(1, 2, 3), Intensity, and H1-H2. The mean data collected from 3 repetitions each was statistically analyzed by Wilcoxon signed rank test for experiment 1 and repeated measures ANOVA for experiment 2. In experiment 1, significant differences were found in the Jitter_rap(Z= -2.10, p=0.036). The findings indicated that the postmedicated voice was worse than premedicated voice. In experiment 2, there wasn't significant difference, but values of parameters related to voice quality(Jitter_rap, Shimmer_apq11, HNR, and H1-H2) showed changes toward stageⅣ, that is, the voice quality was worse under medication.

• The Journal of Information Systems
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• v.32 no.4
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• pp.1-28
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• 2023

Purpose Recently, organizations have been allocating significant financial resources toward the implementation of new technologies and stringent information security (IS) policies in order to enhance IS. However, the potential for IS threats from internal sources within organizations remains high. This study proposes a mechanism whereby the organization's IS environment (organizational justice) enhances employees' perception of IS value congruence and encourages their voice behavior. Furthermore, this study validates that an individual's susceptibility to interpersonal influence can reinforce the relationship between the aforementioned factors and voice behavior. Design/methodology/approach We utilized AMOS 22.0 and Process 3.1 to validate the research model and hypotheses. The data was gathered from 435 employees employed in South Korean firms that implemented IS policies in their work. Structural equation modeling was employed to examine the relationship between organizational justice, value congruence, and voice behavior, and the interaction effect was confirmed by incorporating model 1 of Process 3.1 for the hypothesis pertaining to susceptibility to interpersonal influence. Findings The findings of this study indicate that organizational justice has a positive impact on voice behavior, which is further enhanced by value congruence. Furthermore, the influence of organizational justice and value congruence on voice behavior is moderated by susceptibility to information influence, while susceptibility to normative influence only moderates the effect of organizational justice. These results provide valuable insights for organizations in developing customized information systems strategies that effectively promote employees' voice behaviors.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1413-1415
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• 2004

This paper proposes a SVM(Support Vector Machine) training algorithm to control a service robot with voice command. The service robot with a stereo vision system and dual manipulators of four degrees of freedom implements a User-Dependent Voice Control System. The training of SVM algorithm that is one of the statistical learning theories leads to a QP(quadratic programming) problem. In this paper, we present an efficient SVM speech recognition scheme especially based on less learning data comparing with conventional approaches. SVM discriminator decides rejection or acceptance of user's extracted voice features by the MFCC(Mel Frequency Cepstrum Coefficient). Among several SVM kernels, the exponential RBF function gives the best classification and the accurate user recognition. The numerical simulation and the experiment verified the usefulness of the proposed algorithm.