• The Korean Journal of Emergency Medical Services
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• v.17 no.2
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• pp.21-28
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• 2013

Purpose : The aim of the study is to compare the effect of cardiopulmonary resuscitation (CPR) with voice and CPR without voice by one rescuer. Methods : Subjects were 26 students in C University who had basic life support certificate for Healthcare Provider. They performed 30:2 CPR for 6 minutes by two groups of CPR with voice and CPR without voice by one rescuer from August 14 to 16, 2012. They performed CPR with Resusci Anne SkillReporter$^{TM}$ and Laerdal PC SkillReporting System Ver. 2.4.1(Laerdal Medical, Norway and recored voice using TES-1350A(TES Electrical Electronic Corp, Taiwan). Between each experiment, 1 day of rest was given, providing enough time to recover from the fatigue of CPR. Results : The depth, rate of chest compression, and ventilation volume were not affected by a voice (p >.05), and the ratio of chest compression to ventilation kept 30:2, when the subject made a sound (p <.05). Conclusion : Making voice during CPR was associated with an accurate ratio of 30:2 and the reduction in hands off time.

• The Journal of the Acoustical Society of Korea
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• v.16 no.1E
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• pp.35-40
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• 1997

The LZW algorithm has some redundancies for voice traffic. Thus, the V-LZW(Voice LZW) algorithm that decreases the redundancies of the LZW algorithm is suggested for efficent compression of voice. The V-LZW algorithm uses the differential method that reduces the codeword size as well as the length of repeated string. According to the simulation results, it could be seen teat the performance of V-LZW algorithm is better by 35% to 44% in voice compression ratio than that of the conventional modified LZW algorithm. Compared with conventional 32 kbps ADPCM coding with 26 dB SNR, V-LZW has 21 kbps transmission rate, no additional quantization error and simple hardware complexity.

• The Korean Journal of Emergency Medical Services
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• v.16 no.2
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• pp.31-41
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• 2012

Purpose : The purpose of the present study is to analyze the accuracy and fatigue felt by lay persons receiving CPR training when they perform hands only CPR (HOCPR) and traditional CPR (TCPR). The performance of CPR data will provide the criteria of dispatcher guidelines for the general public. Methods : For 2 minutes duration, HOCPR was conducted by 51 subjects and TCPR was conducted by 48 subjects. The accuracy measurement of chest compressions was based on the 2010 AHA guideline; the subjective fatigue level in before and after experiment was measured by a self-administered questionnaire. Results : There were no significant differences between the average depth, chest compression depth and chest compression location in terms of chest compression accuracy. However, there were significant differences between the two experimental groups in the accuracies for average speed and chest compression speed. The subjective fatigue level showed no significant difference. Conclusion : The experimental group performing HOCPR showed more accurate compression speed and lower fatigue level. These results suggested that HOCPR would be more effective in training the lay persons in accordance with the voice-instructed CPR.

• Journal of Broadcast Engineering
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• v.13 no.5
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• pp.612-621
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• 2008

Due to the various constraints such as feasible size of data payload and low transmission power, no technical specifications on the voice communication are included in the Zigbee standard. In this paper, a voice coding technique for application to the IEEE 802.15.4 standard, which is the basis of Zigbee communication, is presented. Here, both high compression and good waveform recovery are essential. To meet those requirements, a multi-stage discrete wavelet transform (DWT) block and a binary coding block consisting of two different pulse-code modulations are exploited. Theoretical analysis and simulation results in an indoor wireless channel show that the voice coder with 2-stage DWT is most appropriate from the viewpoint of compression and waveform recovery. When the line-of-sight component is dominant, the voice coding scheme has good recovery capability even in the moderate signal-to-noise power ratios. Hence, it is considered that the presented scheme will be a technical reference for the future recommendation of voice communication exploiting Zigbee.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.8 no.1
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• pp.65-68
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• 1997

The mutational falsetto is failure to change from the higher pitched voice of preadolescence to the lower pitched voice of adolescence and adulthood. The one of characteristic findings is contraction of suprahyoid muscles. The large majority of young men with inappropriately high voice have excellent voice therapy prognosis. We have experienced one case of mutational falsetto treated with botulinum toxin injection on suprahyoid muscles. His suprahyoid muscles are contracted markedly simultaneously with each phonation. fundamental frequency$(F_0)$ of his vowel phonation was 332Hz. Extensive voice therapy including manual compression of thyroid notch was ineffective. Forty units of Botox$^{\circledR}$ was injected under the EMG-guidance(20U bilaterally). At seven days post-injection, his voice changed lower than before and at 40 days after procedure, his $F_0$ was 126Hz.

• Proceedings of the IEEK Conference
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• 2000.11c
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• pp.161-164
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• 2000

This paper presents an implementation of internet gateway system, named AX-2000 and call simulator. AX-2000 plays a important role in internet telephony technology and is composed of various board such as MPU, AVU. DVU, AMU. FXS, FXO, EM. Also AX-2000 supports G.729.a, G.723.1 for voice compression, G3 FAX Relay(T.38) and H.323. A capability of AX-2000 is 8 analog voice channel or 30 digital voice channel. For functional verification of AX-2000 voice interface, call simulator is designed. The call simulator makes actual call path between SUT(system under test) and reference AX-2000 system, then through call path examines functions of voice interface.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.490-492
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• 2018

This paper presents an analysis of the AMR speech data as a basic work to study the technique of inputting and transmitting AMR voice data which is widely used in the public cell phone. AMR consists of HEADER and Speech Data, and it is transmitted in bit format and has 8 bit-rate modes in total. HEADER contains mode information of Speech Data, and the length of Speech Data differs depending on the mode. We chose the best mode which is best to input into QR code and analyzed that mode. It is a goal to show a higher compression ratio for voice data by the analysis and experiments. This analysis shows improvement in that it can transmit voice data more effectively.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.6
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• pp.55-61
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• 2013

In this paper, we describe design and implementation of audio encoder/decoder for voice synthesis. It uses the encoding of difference value of successive samples instead of the original sample value. and has the compression ratio of 4. The function is verified by using FPGA and the performance is measured by the fabricated chip using $0.35{\mu}m$ standard CMOS process. The system clock is 16.384MHz. The measured THD+n is from -40dB to -80dB with frequency variation and the power consumption is about 80mW. It is suited for the mobile application of high audio quality and low power consumption.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.4
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• pp.577-585
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• 2010

The Military Tactical Communication technology for effective network-centric warfare is developing. Targeting broadband wireless transmission, core technology for connection, and Transmission technology that secure survivability under High-speed Movement environment. On the one hand, Tactical data communication system that reflects military characteristic is developing on the base of Legacy communication equipment which is used in the field. Because almost every military units in the field have used voice to communicate which lower efficiency of operation, they have made effort to Substitute voice communication which delays military Operation Tempo to digital communication. The Communications environment of troops in Forward edge of battle field area is very poor. Especially in terms of limited frequency allocation and bandwidth. Therefore, improving the efficiency of frequency is essential for Military Tactical Communication. This paper is about The Data Compression Method for increase of Efficiency in Tactical Data Communication over Legacy Radios which are UHF, VHF, HF Radio. I proposed and proved the most efficient Data Compression Method that reflects military characteristic, after analyzing the experimentation, which simulate CAS(Close Air Support mission) data transmission between Pilot and TACP.

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