• Journal of Oral Medicine and Pain
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• 제30권1호
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• pp.69-77
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• 2005

The purposes of this study were to develop and introduce a novel intraoral appliance for bruxism composed of power switch and biofeedback device and further to examine inter- and intra-reliability of the appliance prior to clinical tests. The newly-developed appliance consisted of detection sensors, a central processing unit (CPU), a reactor and a storage unit and a displayer. Compact-sized, waterproof switches were selected as bruxism detection sensor and any sensor activation by clenching or grinding event was processed at the CPU and transmitted, by radio wave, to the reactor and storage unit and triggered auditory or vibratory signal, subsequently producing biofeedback to the patient with bruxism. The data on bruxing event in the storage unit can be displayed on the computer, making it possible analyzing frequency, duration and nature of bruxism. Cast models were obtained from ten volunteers with normal occlusion to evaluate reliability of the appliances. For inter-operator reliability on the intraoral appliances, each operator of the two fabricated the appliance for the same subject and compared the minimal contact forces provoking auditory biofeedback reaction in vertical, lateral and central directions. Intra-operator reliability was also investigated on the appliances made by a single operator at two separate times with an interval of two days. Conclusively, the newly-developed appliance is compact and safe to use in oral circumstance and easy to make. Furthermore, it had to be proven reliability excellent enough to apply in clinical settings. Thus, it is assumed that this appliance with the processor and the storage of data and auditory or vibratory biofeedback function is available and useful to analyze and control bruxism.

• Journal of the Korea Institute of Information and Communication Engineering
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• 제21권6호
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• pp.1149-1154
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• 2017

To obtain good recognition performance of speech recognition system under background noise, it is very important to select appropriate feature parameters of speech. The feature parameter used in this paper is Mel frequency cepstral coefficient (MFCC) with the human auditory characteristics applied to Wiener filter method. That is, the feature parameter proposed in this paper is a new method to extract the parameter of clean speech signal after removing background noise. The proposed method implements the speaker recognition by inputting the proposed modified MFCC feature parameter into a multi-layer perceptron network. In this experiments, the speaker independent recognition experiments were performed using the MFCC feature parameter of the 14th order. The average recognition rates of the speaker independent in the case of the noisy speech added white noise are 94.48%, which is an effective result. Comparing the proposed method with the existing methods, the performance of the proposed speaker recognition is improved by using the modified MFCC feature parameter.

• Journal of Korean Society of Transportation
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• 제28권3호
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• pp.39-49
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• 2010

Provision of in-vehicle warning information is of keen interest since it can be effectively used to prevent traffic accident on the road. This study evaluates the effectiveness of information provision modalities based on kansei engineering. Various warning information scenarios using different modalities are devised for the evaluation. Statistical data analysis techniques including factor analysis, correlation analysis, and the general linear model are used to assess the user's affect for information modalities. The evaluation result shows that the provision of visual information consisted of 'text and pictogram' leads to higher understandability. The combination of beep sound and voice message' was identified as a more effective modality for auditory warning. In addition, the red color for the blinking warning signal was preferred by users.

• The Journal of the Acoustical Society of Korea
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• 제14권1호
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• pp.65-72
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• 1995

An auditory experiments for the phonetic value of the last consonants when its signal is transmitted through the amplifier from the last to the first, shortly speaking, time reversed waveform, were done for the 14 Korean consonants. Then the last consonant becomes to the first consonant in the time reversed waveform. The listeners who heard the 14 reversed consonants have recorded the phonetic value being heard. We analyzed these results by the method of articulation and the position of articulation. By the results, the phonetic value of the last consonants /n/, /l/ and /m/ is the same as the first consonants. Last consonant /d/ is heard like first consonant /n/. Last consonant /ng/ is heard like first consonant /m/. Last consonants /k/ and /b/ don't have any particular phonetic values. These results were tested by the experiments and were analyzed by the principle of articulation.

• The Journal of the Korea institute of electronic communication sciences
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• 제5권6호
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• pp.581-587
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• 2010

In this study, we investigated the effect of the simplification for low frequency region in Head-Related Transfer Function(HRTF) on the sound localization. For this purpose, HRTF was measured and analyzed. The result in the standard deviation of HRTF showed that the directional dependence of low frequency was smaller than that of high frequency region, which means the possibility of simplification in the low frequency region. Simplification was performed by flattening of the low frequency amplitude characteristics with the insertion of the high-pass filter, whose cutoff frequency is given by boundary frequency. Auditory experiments were performed to evaluate the simplified HRTF. The result showed that direction perception was not influenced by the simplification of the frequency characteristics of HRTF for the error of sound localization. The rate of confusion for the front and back was not affected by the simplification of the frequency characteristics within 1kHz of HRTF. Finally, we made it clear that the sound localization was not affected by the simplification of frequency characteristics of HRTF within 1kHz. The result is expected to be utilized to reduce the size of speech information with no deterioration of the directional characteristics of the speech signal.

• Proceedings of the KOSOMBE Conference
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• 대한의용생체공학회 1997년도 추계학술대회
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• pp.63-66
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• 1997

With the advent of high speed digital signal processing chips, new digital techniques have been introduced to the hearing instrument. This advanced hearing instrument circuitry has led to the need or and the development of new fitting approach. A number of different fitting approaches have been developed over the past few years, yet there has been little agreement on which approach is the "best" or most appropriate to use. However, when we develop not only new hearing aid, but also its fitting method, the intensive subject-based clinical tests are necessarily accompanied. In this paper, we present an objective method to evaluate and predict the performance of hearing aids without the help of such subject-based tests. In the hearing impairment simulation (HIS) algorithm, a sensorineural hearing impairment model is established from auditory test data of the impaired subject being simulated. Also, in the hearing impairment simulation system the abnormal loudness relationships created by recruitment was transposed to the normal dynamic span of hearing. The nonlinear behavior of the loudness recruitment is defined using hearing loss unctions generated from the measurements. The recruitment simulation is validated by an experiment with two impaired listeners, who compared processed speech in the normal ear with unprocessed speech in the impaired ear. To assess the performance, the HIS algorithm was implemented in real-time using a floating-point DSP.

• Journal of the Korean Society of Clothing and Textiles
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• 제41권6호
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• pp.1022-1038
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• 2017

Wearable smart products contributed to expand the concept of modern clothing in terms of closer communication between wearers and the surrounding environment. This study investigated the concept of wearable smart actuators and characteristics of actuating feedback. The representative product development trends over the past 10 years are examined based on the method of actuating feedback. A first keyword search from Naver and Google reused to select the final 58 products based on the second key keyword actuating feedback. The wearable smart actuator system works in a similar way to a human body system such as those of the information processing process. Actuating feedback is delivered directly to the user as the last signal of the system, which has visual, auditory and tactile feedback. It works in complex at the device to be delivered to the user. Actuator feedback is divided into three types of active and passive, depending on the user situation, the overall purpose of the product, the collected information, and the device dependency. Active actuating feedback determines and actuates the situation on behalf of the user when the user is in an emergency or a disability situation. Passive actuating feedback plays a role in environmental monitoring to help in a healthy daily life.

• Journal of the Korea Society for Simulation
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• 제21권3호
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• pp.1-9
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• 2012

This paper proposes automatic precision approach radar (PAR) control system using digital signal to increase the safety of aircraft, and discrete event systems specification (DEVS) methodology is utilized to verify the proposed system. Traditionally, a landing aircraft is controlled by the human voice of a final approach controller. However, the voice information can be missed during transmission, and pilots may also act improperly because of incorrectness of auditory signals. The proposed system enables the stable operation of the aircraft, regardless of the pilot's capability. Communicating DEVS (C-DEVS) is used to analyze and verify the behavior of the proposed system. A composed C-DEVS atomic model has overall composed discrete state sets of models, and the state sequence acquired through full state search is utilized to verify the safeness and the liveness of a system behavior. The C-DEVS model of the proposed system shows the same behavior with the traditional PAR control system.

• The Journal of the Convergence on Culture Technology
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• 제4권4호
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• pp.349-354
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• 2018

Human beings have made remarkable advances in medical technology as well as technological advances. However, as was the case in the past, incurable diseases still exist: temporo-mandibular joint (TMJ). The diagnosis of the Korean medical staff, currently called a "medical advance," is adhering to the outdated patient's comments, diagnosis using a doctor's auditory diagnosis and a ruler, and diagnosis of X-ray imaging. Therefore, it is important to have accurate patient symptoms, to have a doctor's own diagnosis and experience, to increase the number of diagnoses due to the severity of the symptoms, and to cover the costs of medical care. To solve this problem, the core conductive signal generated from the bridge was quantified through %MVC. Quantified EMG will be assessed and compared with Cortex to establish a jaw joint condition evaluation criterion.

• Korean Journal of Audiology
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• 제25권2호
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• pp.72-79
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• 2021

Background and Objectives: The speech-in-noise test is typically performed using an audiometer. The results of the digit-in-noise recognition (DIN) test may be influenced by the flat frequency response of free-field audiometry and frequency of the hearing aid fit based on fitting rationale. This study aims to investigate the DIN test in unaided and aided conditions. Subjects and Methods: Thirty four adults with moderate and severe sensorineural hearing loss (SNHL) participated in the study. The signal-to-noise ratio (SNR) for 50% of the DIN test was obtained in the following two conditions: 1) the unaided condition, performed using an audiometer in a free field; and 2) aided condition, performed using a hearing aid with an unvented individual earmold that was fitted based on NAL-NL2. Results: There was a statistically significant elevation in the mean SNR for the severe SNHL group in both test conditions when compared with that of the moderate SNHL group. In both groups, the SNR for the aided condition was significantly lower than that of the unaided condition. Conclusions: Speech recognition in hearing-impaired patients can be realized by fitting hearing aids based on evidence-based fitting rationale rather than by measuring it using free-field audiometry measurement that is utilized in a routine clinic setup.