• Proceedings of the IEEK Conference
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• 2000.06a
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• pp.77-80
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• 2000

In this paper, we implemented the voice modem using the multicarrier DS-CDMA in powerline channels. Both TMS320C5402 of Texas Instrument and FPGA FLEX 10K EPF10K100ARC240 of ALTERA are used to realize the proposed system. For robustness in the powerline channel, we used multicarrier DS-CDMA modulation, convolutional encoding/Viterbi decoding, and interleaving. Finally, we showed satisfactory performance in the laboratory experiment.

• Proceedings of the IEEK Conference
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• 2000.11d
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• pp.187-190
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• 2000

In this paper, implementation of speech Recognizer system, Separated from Personal computer. By using DSP, this intends to extend the voice recognizing, limited into PC because of amount of data and calculations. For this performance The thesis uses the real time End point detector and organizes no additional device between human and the system, characteristic vector are that detects End point and voice from absolute energy and ZCR, that uses 12 difference Cepstrum from LPC, that uses the method to compensate the process of pattern separating and pre-calculated standard pattern limitation.

• Journal of Advanced Navigation Technology
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• v.21 no.1
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• pp.113-118
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• 2017

As interest in mobile devices and networks has increased recently, voice over internet protocol (VoIP) service, which is a technology for transmitting voice data using an existing internet protocol (IP) network, has rapidly spread, Cheap voice call service has become possible. As the digital broadcasting service becomes popular, hybrid fiber coaxial (HFC) network technology, which uses broadband cable network through fusion of broadcasting and communication, utilizes existing communication system and network equipment to provide various new services such as interactive broadcasting service. Therefore, if UGS-AD is applied to VoCM and RTPS is applied to MTA in order to guarantee the quality of voice data in actual HFC Internet service network, it is possible to smoothly perform voice data transmission in narrow upstream band which is a problem in actual commercial HFC network We also proposed a method to improve VoIP service by improving QoS of voice data in HFC Internet service network.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.12
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• pp.4849-4865
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• 2020

The traditional roles of leaders are to influence members and motivate them to achieve shared goals in organizations. However, leaders such as top managers and chief executive officers, in practice, do not always directly meet or influence other company members. In fact, they tend to have the greatest impact on their members through formal speeches, company procedures, and the like. As such, official speech is directly related to the motivation of company employees. In an official speech, not only the contents of the speech, but also the voice characteristics of the speaker have an important influence on listeners, as the different vocal characteristics of a person can have different effects on the listener. Therefore, according to the voice characteristics of a leader, the cognition of the members may change, and, the degree to which the members are influenced and motivated will be different. This study identifies how members may perceive a speech differently according to the different voice characteristics of leaders in formal speeches. Further, different perceptions about voices will influence members' cognition of the leader, for example, in how trustworthy they appear. The study analyzed recorded speeches of leaders, and extracted features of their speaking style through digital speech signal analysis. Then, parameters were extracted and analyzed by the time domain, frequency domain, and spectrogram domain methods. We also analyzed the parameters for use in Natural Language Processing. We investigated which leader's voice characteristics had more influence on members or were more effective on them. A person's voice characteristics can be changed. Therefore, leaders who seek to influence members in formal speeches should have effective voice characteristics to motivate followers.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.1
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• pp.57-65
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• 2012

People leave voicemails or record phone conversations in their daily cell phone use. Sometimes important voice data is deleted by the user accidently, or purposely to cover up criminal activity. In these cases, deleted voice data must be able to be recovered for forensics, since the voice data can be used as evidence in a criminal case. Because cell phones store data that is easily fragmented in flash memory, voice data recovery is very difficult. However, if there are identifiable patterns for the deleted voice data, we can recover a significant amount of it by researching images of it. There are several types of voice data, such as QCP, AMR, MP4, etc.. This study researches the data recovery solutions for EVRC codec and AMR codec in QCP file, Qualcumm's voice data format in cell phone.

• Smart Media Journal
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• v.9 no.3
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• pp.116-121
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• 2020

Digital Information Display and KIOSK have a problem that initial introduction cost and maintenance cost due to the development cost of dedicated contents and installation cost are high due to the characteristics of the product. In order to solve these problems, We designed and implemented of voice transmission system using Open Source Hardware and Event based Non-Blocking I/O Algorithm.

• Journal of Korea Society of Digital Industry and Information Management
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• v.7 no.2
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• pp.39-46
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• 2011

Privacy IP hacking problems such as invasion of privacy, password cracking, voice wiretapping and internet over charged occurred, because VoIP internet voice phone service gradually spread. This thesis attempted to attack the VoIP service network by application. First use application to spoof IP address then attempted wiretap the VoIP service and sends a lot of messages to disturb service movement. At this point, we connected VoIP soft terminal, so we can operate real-time filtering operator to block the SIP Flooding offence by monitor the traffic and detect the location where it got attacked. This thesis used experiment to prove it is possible to detect the offence and defend from SIP Flooding offence.

• Proceedings of the Korean Society of Computer Information Conference
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• 2012.07a
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• pp.269-270
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• 2012

본 논문에서는 키패드로만 동작하는 디지털 도어락에 보안을 강화하기 위해 음성 인식 장치를 추가한 음성 인식 디지털 도어락을 설계하고 구현하였다. 비밀번호로만 동작하는 도어락은 비밀번호의 분실 가능성이 있기 때문에 보안을 위해서는 화자의 특징을 인식할 수 있는 화자 종속 방식의 음성인식이 효율적이다. 본 논문에서 제안하는 방식은 가정집뿐만이 아니라 회사에서 보다 높은 수준의 보안이 필요한 곳에서 사용이 가능하다. 또한 구현한 시스템은 장애인을 위해 음성만으로 동작하는 시스템 등으로 쉽게 변경이 가능하다. 제안한 시스템은 ATmega128을 기반으로 키패드, 텍스트 LCD, 음성인식 모듈을 결합하여 구성하였다.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1987.04a
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• pp.82-85
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• 1987

This paper describes the technology for the improvement of subxdriber loop utilization. Nearly all customer loops are now carried at voice frequency on individual wire pairs. Reenct digital technology improvements together with the increasing cost of wire, have resulted in some penetration of carrier systems into the loop plant. Moreover the increasing use of local digital switching systems should permit digital carrier systems to become an important factor in the loop plant in the future.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.98.2-98
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• 2001

It is necessary to have enough transmission capacity for advanced internet techniques and various digital home appliances networking. Home appliances interface IEEE1394 technique has much wealthy transmission skill. IEEE1394 is using home appliances through various information form image and voice change data real time print out. In this paper, AVC CTS technology and IEEE1394 technology are introduced. Digital Video Camera includes compression format using DV. System composition control is consisted of protocols like IEC-61883 and AV/C command set standard.