• The Journal of the Acoustical Society of Korea
• /
• v.33 no.1
• /
• pp.75-80
• /
• 2014

The quality of real-time Voice over Internet Protocol (VoIP) network is affected by network impariments such as delays, jitters, and packet loss. This paper proposes a packet loss concealment algorithm based on voice classification for enhancing VoIP speech quality. In the proposed method, arriving packets are classified by an adaptive thresholding approach based on the analysis of multiple features of short signal segments. The excellent classification results are used in the packet loss concealment. Additionally, linear prediction-based packet loss concealment delivers high voice quality by alleviating the metallic artifacts due to concealing consecutive packet loss or recovering lost packet.

• Journal of the Korean Society of Industry Convergence
• /
• v.17 no.2
• /
• pp.42-53
• /
• 2014

Robust voice recognition (RVR) is essential for a robot to communicate with people. One of the main problems with RVR for robots is that robots inevitably real environment noises. The noise is captured with strong power by the microphones, because the noise sources are closed to the microphones. The signal-to-noise ratio of input voice becomes quite low. However, it is possible to estimate the noise by using information on the robot's own motions and postures, because a type of motion/gesture produces almost the same pattern of noise every time it is performed. In this paper, we propose an RVR system which can robustly recognize voice by adults and children in noisy environments. We evaluate the RVR system in a communication robot placed in a real noisy environment. Voice is captured using a wireless microphone. Navigation Strategy is shown Obstacle detection and local map, Design of Goal-seeking Behavior and Avoidance Behavior, Fuzzy Decision Maker and Lower level controller. The final hypothesis is selected based on posterior probability. We then select the task in the motion task library. In the motion control, we also integrate the obstacle avoidance control using ultrasonic sensors. Those are powerful for detecting obstacle with simple algorithm.

• Journal of IKEEE
• /
• v.13 no.3
• /
• pp.62-71
• /
• 2009

In this study, we developed a wireless CROS(contralateral routing of signal) hearing aid for unilateral impaired people. CROS hearing aid takes sound from an ear with poorer hearing and transmit to another ear with better hearing. Generally, the self-voice delivered through the receiver of CROS hearing aid can be very loud. It is hard to perceive target speech because of loud self-voice. To compensate it, a self-voice suppression algorithm has been developed. we performed SDT(speech discrimination test) for evaluation of the self-voice suppression algorithm. One-syllable words was used as test speech and recorded with self-voice at a 1m distance. As the results, SDT score was improved about 11% when the self-voice suppression algorithm was processed. It is verified that the self-voice suppression algorithm helps speech perception at a time to communicate with others.

• The Journal of the Acoustical Society of Korea
• /
• v.31 no.6
• /
• pp.359-366
• /
• 2012

Today, people are exposed to the various noisy environments, such as in the buses, subway and supermarkets where there are a lot of people. The noise issue is getting more serious as people want to use portable sound equipment and mobile phones even under this noisy condition. People want to use the portable equipment to exchange the information freely and they set the volume as 15dB higher than the noise around them, which almost reach at 110 dB. That amount of sound can cause noise induced deafness to the users and another issue to the others as additional noise source. A Bone-conduction system can be a solution to reduce noise and enhance voice signal of mobile phone. In this paper, we propose the way of cancelling noise and enhancing speech signal of mobile phones, by installing bone-conduction feedback system with ordinary mobile phones. With this system, we can reduce the environment noise and enhance the voice quality of mobile phones. Using this method, we can enhance the signal by around 17 dB.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.37A no.9
• /
• pp.792-798
• /
• 2012

Network Quotient, an important figure in modern society, the intelligibility of speech as a conversation partner to maximize pulling up feeling of liking it as much as possible has become an important issue. The humidity of air in the intelligibility of speech have many influences. Therefore, in this paper, we carried out experiment to apply voice signal analysis techniques which to analyze influenced vocal cords in 30%, 50% and 80%, maintaining a constant humidity of the environment. With this in mind, we carried out experiments on intensity and pitch of voice signal on twenty male 20s in maintaining a constant humidity 30%, 50% and 80% of humidity. Finally, we carried out study to draw a significance through statistical analysis measuring characteristic parameter of vocal cord function to change of humidity.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2018.05a
• /
• pp.533-535
• /
• 2018

In the 21st century, in which the accident rate is rapidly increasing in proportion to the development of automobiles, In order to reduce the number of accidents, this paper was written for the convenience of the elderly people with disabilities and the handicapped. When a driver's safety accidents and various signals are transmitted through a smart phone by voice, the voice signal is processed as a video signal through the rear LED pannel of the vehicle, so that an urgent situation or a current state can be clarified It is also possible to use the local area network as a billboard and I would like to propose a study to show the advertising effect and current traffic situation.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.17 no.6
• /
• pp.1181-1186
• /
• 2022

In this study, we have researched for a high-efficiency display with low power, less complicated configuration, and more attractive features than using conventional displays (CRT, LCD, LED, etc.) by manufacturing a propeller display using the POV(Persistence of Vision) phenomenon. After setting the reference point using the Hall sensor, the channel recognition signal and voice recognition signal are transmitted to the display using Bluetooth through the mobile phone application created based on the App program, and the display performs different operations according to the commanded Bluetooth signal. Finally, it was confirmed that the desired information is expressed on the display screen at a motor speed of 1,030 rpm.

• The KIPS Transactions:PartB
• /
• v.19B no.2
• /
• pp.77-82
• /
• 2012

We carried out study to prove effectiveness as stimulating corresponding points to lung in hand to experiment applied analysis parameters for image and audio signals in this paper. To this end we collected facial image and voice before and after stimulating corresponding points to lung in hand to a male 20s 25 people. In addition, we analyzed change color, voice energy and speaking rate of right cheek area corresponding points to lung to suggest the theory of the Oriental medicine diagnosis based on data collected. As a result, after performing hand acupuncture, L value of right cheek area decreased average 2.33 and a value b value increased 0.76, 0.97 on average. In addition, size of voice energy increased average 0.42, speaking rate decreased average 0.07. In other words, effect of lung function was improved using hand acupuncture corresponding points to lung.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.40 no.5
• /
• pp.924-930
• /
• 2015

In this paper, we propose a novel approach of low computational complexity to improve the speech quality of the small acoustic equipment in noisy environment. The conventional gain control algorithm suppresses the noise of input signal, and then the part of wide dynamic range compression (WDRC) amplifies the undesired signal. The proposed algorithm controls the gain of hearing aids according to speech present probability by using the output of a voice activity detection (VAD). The performance of the proposed scheme is evaluated under various noise conditions by using objective measurement and yields superior results compared with the conventional algorithm.

• Journal of the Korean Society for Precision Engineering
• /
• v.18 no.12
• /
• pp.152-158
• /
• 2001

In this paper, we have developed an electro discharge machine for micro drilling driven by a voice coil actuator. Because the voltage signal of the electro-discharging circuit shows a lot of peaks and valleys, the active type low-pass filtering technique is adopted to get the average of the signal. Since the motion of the voice coil is precisely controlled by the error value between the object voltage value and the measured one, it is possible to prevent the mechanical contact between the rotating electrode and the workpiece and to maintain the appropriate machining conditions during the process. The electro-chemical machining technology was also adopted to make small diameter electrodes. Pure water is used as a dielectric. The machining procedure is performed to verify the feasibility of the developed system. It takes about 10 seconds to drill the ${\phi}m$100${\mu}m$ hole to the 100${\mu}m$ thickness stainless steel plate. The machining time depends on the values of the resister and the capacitor. There may exist the optimal values of time constant and the tendency is displayed In the appendix.