• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.1
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• pp.67-74
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• 2009

Information Effluence leaks are caused by the wide use of the P2P program in Japan and Korea lead by the increase of internet use and network infrastructure expansion. This research confirms the seriousness of the data collected from the P2P leaks of the two countries and furthers its study by researching how countermeasures are applied. The effectiveness is verified by collecting data according to countermeasure applied periods. Both countries had information leaks, but in the case of Japan, not only personal information leaks but corporation, administrative agency, military, and others in a wide range as well. As a countermeasure against information effluence, Korea is enforcing counter plans mainly against the P2P service businesses and for Japan, various plans are taken such as business guides for each agency, organization management, SW development and supply, HW supply, and ect. The leaks in Japan were more severe than the ones in Korea but they had well planned countermeasures that were applied. Therefore if the Japanese countermeasure on information effluence of P2P programs is taken as a lesson, Korea can prevent the problem of leaks beforehand.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.3
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• pp.161-168
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• 2011

This paper provides the performance measurement and analysis of Wireless LAN IEEE 802.11 in a mobile environment. The performances of IEEE802.11b/g and IEEE802.11p designed for Vehicle-to-Vehicle(V2V) communication are measured and analyzed. Diameter of communication and link access time are compared under variation of speed of the vehicle.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.11C
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• pp.955-962
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• 2008

Multicast Strategy is one of the cost-saving methods in the large scale VOD environment. However, it does involve complicated problems to implement VCR-like interactions for user's convenience in the multicast streaming system under considering the limited-server and the network's bandwidth in the multicast-transmission system. Therefore, the proper solution of settling such a problem is necessary. Thus, this paper which revised P2Patching[l] proposes LGST(Level Group Streaming Technique) which supports the VCR's function through cooperation among peers with heterogeneous bandwidth under the environment of P2P. This strategy can reduce latency by improving the acceptance of server and using the bandwidth of network efficiently. And for evaluate the proposed scheme's performance, I simulated the performance of streaming delivery topology and streaming quality in comparison with P2Patching. In evaluation to service request refusal ratio and service quality according to bandwidth decrement, the result of simulation shows that proposed LGST improves about $11{\sim}18%$ of performance than P2Patching. In the test of latency recovery according to fault probability and influence of VCR function operation duration, it shows similar performance.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.1091-1094
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• 2009

In order to find the characteristics of selected powerful Pseudomoanas sp. KU171(pKU19) degrading MCPA, many physiological and genetic tests were accomplished. By the curing and transformation experiment, it was found that the genes of Pseudomonas sp.KU171(pKU19) for MCPA-degrading were located on a plasmid pKU19. Also the plasmid had degradative gens for 2,A-D, 3CB, and DCP. Molecular size of pKU19 was measured to be 31.2Kb.

• ETRI Journal
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• v.34 no.4
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• pp.591-601
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• 2012

Unstructured peer-to-peer (p2p) networks usually employ flooding search algorithms to locate resources. However, these algorithms often require a large storage overhead or generate massive network traffic. To address this issue, previous researchers explored the possibility of building efficient p2p networks by clustering peers into communities based on their social relationships, creating social-like p2p networks. This study proposes a social relationship p2p network that uses a measure based on Hebbian theory to create a social relation weight. The contribution of the study is twofold. First, using the social relation weight, the query peer stores and searches for the appropriate response peers in social-like p2p networks. Second, this study designs a novel knowledge index mechanism that dynamically adapts social relationship p2p networks. The results show that the proposed social relationship p2p network improves search performance significantly, compared with existing approaches.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.6
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• pp.269-273
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• 2010

Massively Multiplayer Online Game (MMOG) is one of diverse applications where more than hundreds of users enjoy experiencing virtual worlds. Voronoi-based Overlay Network (VON) is proposed to reduce a bandwidth consumption in P2P MMOGs and Vorocast also is made using message forwarding in VON. We propose a dynamic area of interest (AOI) management method that solves problems such as less consistency and high latency due to sending position updates to more neighbor nodes from the message originator in forwarding scheme. Our scheme provides the higher consistency and reduces latency by combining direct connection scheme and Vorocast scheme compared to existing schemes. The proposed model is evaluated through simulations.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.10 no.4
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• pp.121-127
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• 2011

Many peer-to-peer (p2p) systems have been studied in distributed, ubiquitous computing environments. Distributed hash table (DHT)-based p2p systems can improve load-balancing even though locality utilization and user mobility are not guaranteed. We propose a mobile locality-based hierarchical p2p overlay network (MLH-Net) to address locality problems without any other services. MLH-Net utilizes mobility features in a mobile environment. MLH-Net is constructed as two layers, an upper layer formed with super-nodes and a lower layer formed with normal-nodes. Because super-nodes can share advertisements, we can guarantee physical locality utilization between a requestor and a target during any discovery process. To overcome a node failure, we propose a simple recovery mechanism. The simulation results demonstrate that MLH-Net can decrease discovery routing hops by 15% compared with JXTA and 66% compared with Chord.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.588-591
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• 2002

P2P(Peer-to-Peer) can compose free network and take away center server function or problem about authentication is risen between each User because is opening network that can participate between each User weakening. We desire to authenticate request about service to user who is admited between each user to limit connection. Wish to admit Kerberos authentication mechanism to mechanism that can do information sharing safety in P2P environment to solve this in this treatise and design authentication mechanism.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.3
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• pp.575-580
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• 2008

Lately, the use of the NAT has become unavoidable with the increase of P2P traffic along with the exhaustion of IPv4 IP address. Due to NAT properties, NAT's internal host can only be connected through a relay method using the outside server. Accordingly, there is a lot of resource exhaustion of the relay server on the NAT exterior and network traffic increases. This essay proposes a topology that can form sessions to the NAT interior from the NAT exterior and that will decrease network traffic by placing NAT exterior relay servers in the NAT interior.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.2
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• pp.23-29
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• 2015

The baby-step giant-step algorithm seeks b in a discrete logarithm problem when a,c,p of $a^b{\equiv}c$(mod p) are already given. It does so by dividing p by m block of $m={\lceil}{\sqrt{p}}{\rceil}$ length and letting one giant walk straight toward $a^0$ with constant m strides in search for b. In this paper, I basically reduce $m={\lceil}{\sqrt{p}}{\rceil}$ to p/l, $a^l$ > p and replace a giant with an adult who is designed to walk straight with constant l strides. I also extend the algorithm to allow $2^k$ adults to walk simultaneously. As a consequence, the proposed algorithm quarters the execution time of the basic adult-walk method when applied to $2^k$, (k=2) in the range of $1{\leq}b{\leq}p-1$. In conclusion, the proposed algorithm greatly shorten the step number of baby-step giant-step.