• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1983.10a
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• pp.124-126
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• 1983

This paper presents automated system for trunk test in a telephone network. Test results anlysis were executed by the controller using a microprocessor. Transmission measurements for loss, error are made by the automated measuring enipment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.4
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• pp.821-835
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• 1998

The Digital Audio-Visual Council(DAVIC) that was established to develop useful multimedia communication services has completed the specifications for providing on-demand services such as Movie on Demand(MoD), Teleshopping and accepting Internet service. And then they are proceeding the works to suport converstional communcation services like Plain Old Telecphone Service(POTS), Video telephone, Video teleconferencing. In this paper, we prpose an efficient terminal architecture which can provide conversational multimedia communication services on DAVIC Set-Top Box (STB) environments. To apply the implemented conversational terminal to the multipoint communication environment, we considered the factors of Qurlity of Services(QoS) that determine grade of conversational communication service. We also present the inter-working scheme and that system structure to satisfy QoS by using new MPEG video bridge which gurantees end to end delay requirements as major element of QoS for achieving the real time communication and does not accompany visual quality degradation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.249-252
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• 2011

National Information and Communication Services of Public Administration and Security organized by the 'A' group (Line service network), 'B' group (IP service network), 'C'Group (Voice over Internet protocol(VoIP) service, IP application services) are provided by constructing the infrastructure. National Information and Communications Services 'C' group, providers are providing VoIP services. In this paper, national information and communications service 'C' group, providers of domestic calls, international calls, including calls to move we will study the basic telephone service. And text messaging, video telephony, IP-Centrex services, etc. we will study the seven value-added services. In addition, national information and communication service providers on the status of the project based on the analysis of national information and communication Internet telephone network using Internet telephony is the type of analysis. In this study, national information and communications services industry, will serve as the basis for the development.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2000.11a
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• pp.471-475
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• 2000

Voice and data are transmitted over a single packetized data communications network which is designed for data communications. The public switched telephone network for voice and the packet data network for data are merging into a single data network to get efficiency and to reduce operational cost. However, integrating voice and data transmission over a single data network is not easy because voice should be transmitted without delay but data should be transmitted without error. Advances in technology begin to overcome basic differences. Several integration methods in voice and data will be examined and reviewed here. Moreover, trends and problems on integration will be also discussed.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.2
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• pp.73-80
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• 2009

Although it is relatively difficult to eavesdrop the commonly used PSTN in that it is connected with direct circuit, it is difficult to ensure the secret of call on Internet because many users can connect to the Internet at the same time. However, it is needed to ensure secret of voice call in a special situation. Due to the fact that many users can connect to the internet at the same time, VoIP can always be in a defenseless state by hackers. Therefore, in this paper, we have developed the increased voice security internet telephone terminal and measured conversation quality by adopting VPN PPTP based on SIP and using tunnel method in transmitting voice data to prevent eavesdrop of internet telephone.

• Journal of Digital Contents Society
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• v.19 no.4
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• pp.661-671
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• 2018

The avoidance tendency of voice call in younger generation facilitates the growth of mobile O2O service that utilizes Messaging. This study adopted and elaborated original concepts of telephone apprehension to apply phone anxiety to O2O. We examined previous researches related to the ubiquity of service quality, communication ability and anxiety, and then conducted a survey to understand the consciousness of mobile O2O service users. The results show that users with high message intimacy and users with poor logicality are afraid of voice calls. The mobile O2O service is considered useful as a means to replace an unstable situation. In this study, we considered individual characteristics of acceptance factor of O2O mobile service technology, and it was a new attempt to expand telephone apprehension characteristic reflecting current situation. In addition, the different results of this research from prior studies that examined the relationships among apprehension, usefulness, and continuous use intentions might be helpful to expand and sophisticate the research area.

• Journal of Digital Convergence
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• v.9 no.5
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• pp.225-233
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• 2011

Internet telephony is an Internet service which supports voice telephone using VoIP technology on the IP-based Internet. It has some advantages in that voice telephone services can be accompanied with multimedia services such as video communication and messaging services. Recently, the introduction of smart phones has led to a growth in social networking services and thus, the research and development of Internet telephony has been actively progressed and has the potential to become a replacement for the telephone service that is currently being used. In this paper we designed and implemented a recording system which records voice data of SIP-based Internet telephone's voice calls. It is developed on the linux system and has some features such as audio mixing of two in/out voice channels, live packet sniffing, and the ability to transfer mixed audio files to the log file server. These functions are implemented using various open source softwares. Afterwards, this VoIP recording system will be applied as a base technology to advanced services like a VoIP-based call center system.

• International journal of advanced smart convergence
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• v.8 no.3
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• pp.69-77
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• 2019

Today, most of elevators have an emergency call facility for emergency situations. However, if the network installed in the elevator is also out of power, it cannot be used for the elevator remote monitoring and management. So, we develop an integrated and unified emergency call system, which can transmit not only telephone call but also data signals using PSTN(Public Switched Telephone Network) in order to remote monitoring and management of elevators, even though a power outage occurs. The proposed integrated emergency call system to process multiple data such as voice and operational information is a multi-channel board system which is composed of an emergency phone signal processing module and an operational information processing module in the control box of elevator. In addition, the RMS(remote management server) systems based on the Web consist of a dial-up server and a remote monitoring server where manages the elevator's operating information, status records, and operational faults received via the proposed integrated and unified emergency call system in real time. So even if there's a catastrophic emergency, the proposed RMS systems shall ensure and maintain the safety of passengers inside the elevator. Also, remote control of the elevator by this system should be more efficient and secure. In near future, all elevator emergency call system need to support multifunctional capabilities to transmit operational data as well as phone calls for the safety of passengers. In addition, for safer elevators, it is necessary to improve them more efficiently by combining them with high-tech technologies such as the Internet of Things and artificial intelligence.

• Journal of Families and Better Life
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• v.24 no.5 s.83
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• pp.101-112
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• 2006

This study examined factors related to the motivation for the uses of cellular phones and the relationship between motivation for cellular phone use and parent-child communication among middle school students. A total of 223 questionnaires were submitted and analyzed. The characteristics of motive structure of the middle school students were found as recreation, time management, information-seeking, reassurance and fashion/showing off. Among those motivations, these middle school students examined here were found to use cellular phones in similar ways to how conventional telephone is used such as work/instrumental reasons and socializing/entertaining. The motivations showed a significant association with the level of parent-child communication. Information-seeking and time management motivation were positively related with an open communication level while fashion/showing off and recreation were negatively related with an open communication level.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.180-183
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• 1997

In this paper, we present the Tele-consulting system of radiology, which uses the communication network as asymetric satellite data communication system. The asymetric satellite data communication system uses receive-only satellite links or data delivery and PSTN(Public Switched Telephone Network) modem or N-ISDN(Integrate Services Digital Network) for communication. The satellite communication linking shows the very high-speed performance than 28.8kbps modem linking. The satellite linking is 5 - 10 times aster than the modem linking. Consequently, we get the conclusion that our system is suitable or tele-radiology and telemedicine.