• The KIPS Transactions:PartC
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• v.10C no.5
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• pp.641-646
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• 2003

Packet processing speed of routers as well as transmission speed of physical links gives a great effect on IP packet transfer rate in Internet. The router forwards a packet after determining the next hop to the packet's destination. IP address lookup is a main design issue for high performance routers. In this paper, we propose a partitioned compressed-trie for speeding-up IP address lookup algorithms based on tie data structure by exploiting path compression. In the ,proposed scheme, IP prefixes are divided into several compressed-tries and lookup is performed on only one partitioned compressed-trie. Memory access time for IP address lookup is lessen due to compression technique and memory required for maintaining partition does not increased.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.584-588
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• 2007

A comparative Life Cycle Assessment(LCA) among three types of Electric Motor Unit(EMU) Interior Panel(IP) was conducted. A functional unit for comparative LCA is a weight of IP for 1 EMU. It assumed that Manufacturing stage and its upstream processes, Use stage and End of Life(EoL) stage are included in the boundary of product system. For Use stage, the weight of IP causes electricity consumption. It is assumed that aluminum IP is recycled and the other IPs are incinerated at the EoL stage. As comparison results, aluminum IP has much larger environmental impact(5.162pt) than others(FRP IP; 4.069pt, Phenol IP; 4.053pt) even though recycling consideration is included. The manufacturing stage of aluminum has relative big envrionmental impact(1.824pt) and this point make the most important difference from other IPs(FRP IP; 0.1617pt, Phenol IP; 0.4534pt)). Despite of large weight difference between FRP IP(888.56Kg) and phenol IP(315Kg), the final environmental impact result has only little difference(0.016pt, 0.39%). With this result, the EMU designer can choose IP with a consideration of the environmental performance of IP.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.5
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• pp.857-864
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• 2020

The multi-functional VoIP phone supports the Ethernet protocol in the TIPS(: Tactical IP Switch), which is one of the sub-systems of the tactical information and communication system (TICN). It provides secured voice / video calls in conjunction with VoIP exchanges and supports differential services such as multi-party calls and command functions. In this paper, improving methods have been proposed to reduce power supply defects in the field of multi-functional VoIP phones. The power supply part was improved by applying TVS of the output voltage inlet of the dedicated adapter of the multi-functional VoIP phone, TVS of the PoE module input, adding blocking diodes, and adding DC / DC converters behind the poly-switch. Also, functional and environmental tests were performed to verify the validity of the proposed methods.

• The KIPS Transactions:PartA
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• v.14A no.1 s.105
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• pp.1-14
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• 2007

MPICH-G2 is an MPI implementation to solve complex computational problems by utilizing geographically dispersed computing resources in grid environments. However, the computation nodes in MPICH-G2 are exposed to the external network due to the lack of supporting the private IP clusters, which raises the possibility of malicious security attacks. In order to address this problem, we propose MPICH-GP with a new relay scheme combining NAT(Network Address Translation) service and an user-level proxy. The proxy running on the front-end system of private IP clusters forwards the incoming connection requests to the systems inside the clusters. The outgoing connection requests out of the cluster are forwarded through the NAT service on the front-end system. Through the connection path between the pair of processes, the requested MPI jobs can be successfully executed in grid environments with various clusters including private IP clusters. By simulations, we show that the performance of MPICH-GP reaches over 80% of the performance of MPICH-G2, and over 95% in ease of using RANK management method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.1
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• pp.127-133
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• 2009

It has been 10 years long since the emergence of Dialpad, the first commercial VoIP service from Saerome Technology launched on 1999. In spite of so many research papers and implementations of the VoIP and commercial services with hundreds of VoIP-related products vendors and tens of VoIP service providers during the last decade, the resulting market share of the VoIP callings at the year 2007 in Korea is just about 0.3%, which is extraordinary lower one than expected. There have been proposed several facts for the reason including the QoS issue and the incomplete governing system. In this paper we suggest that the reason is based on the sociocultural issue and further we assert and verify that it can never replace the existing legacy telephone system for the current VoIP service model, as long as the telecommunication companies continue the legacy telephone service. We also suggest the another choice, to upgrade the concept of the current VoIP service to a new paradigm based on SIP and presence service, while letting the legacy telephone system be as it is.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.5
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• pp.1131-1136
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• 2015

VoIP and IP Telephony telephony technology development is a growing by easy to using IP-PBX by using phone from using existing lines rather than the internet. IP-PBX do not use the phone line from phone work for many companies and institutions of management costs reduce as provides similar to regular phone line quality. But IP-PBX to introduce for need to be the initial cost on is should buy for expensive hardware equipment or commercial software. In this paper, suggest way to introduce IP-PBX do not buy expensive hardware equipment or commercial software. Suggest IP-PBX on designed and implement for IP-PBX server using Raspberry Pi and Asterisk. And verification treatise on the suitability of conducted by voice calls based on IP-PBX between PC and a Smartphone

• IE interfaces
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• v.11 no.3
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• pp.77-87
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• 1998

Intelligent Peripheral(IP) system is to provide specialized resource functions (SRF) such as playing announcement, collecting user information, and receiving messages in the Advanced Intelligent Network (AIN). We analyze the call processing capacity of an AIN IP system being developed in ETRI through an extensive simulation using SLAM II under a variety of AIN service scenarios. We consider televoting (VOT) and universal personal telecommunication (UPT) services which are to be provided at the fit implementation of the AIN in Korea. As the performance criteria to determine the call processing capacity, processor utilization, delay and call loss probability are considered. It turns out that the major processor called SAMP is the bottleneck processor, the service response delay dominates the delay performance, and the call loss probability becomes the primary criterion in determining the call processing capacity of the AIN IP system. It is also shown that the call processing capacity of the AIN IP system is determined by the utilization of the processor and the delay performance when the VOT ratio is below 70 percent but it is determined by the call loss probability due to the lack of service channels for providing the SRF operations.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.6
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• pp.143-150
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• 2011

In this paper, we intend to implement system of the automation of foul/waste water disposal plant by using processed sensor data. We designed the model of communication system based on wireless indoor environment, implemented monitoring and control system based on IP. In the implemented monitoring system, it is possible to control and monitor through not only PC but also smart device(tablet PC, smart phone) anywhere, if WEB is connected.

• Journal of Digital Convergence
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• v.10 no.6
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• pp.259-267
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• 2012

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 an Internet telephony network system which is developed by using Asterisk and open source softwares. It is developed on the linux system and has some features such as VoIP telephony service between SIP phones, voice mail, and call recording. It also supports web-based functions such as SIP users and server system management that is implemented by Apache web server and PHP programs. Afterwards, this system will be applied as VoIP network base technology for small sized companies and organizations. It will paly a role for encouraging companies to use open source softwares.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.05a
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• pp.1235-1238
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• 2006

VoIP(Voice over IP)는 IP를 이용하여 음성과 데이터를 패킷 형태로 통합하여 실시간으로 전송하는 기술이다[1]. 본 논문에서는 VoIP망에서 리눅스 기반 IP 녹취 시스템을 설계 및 구현한다. 녹취 시스템은 고객과 상담원의 통화 내용을 자동으로 녹음하여 보관함으로써 고객의 요구 사항을 명확히 파악할 수 있다. 녹취 시스템으로 모든 네트워크 환경에서 사용할 수 있으며 CTI와 연동하여 효율적이고 체계적인 녹취 시스템 구축이 가능하다.