• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.2
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• pp.370-376
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• 2009

Recently, Study for routing protocol is gone vigorously in the Ubiquitous Sensor Network. A hierarchical routing protocol is being practical and received interest among them. Therefore we analyze a weak point of HEED. And I suggest the new protocol that solved a weak point of HEED. The new protocol that we propose puts weight in the energy remainder amount than HEED and elect CH. And elected CH is designed to change by new node when quantity of energy leftover becomes less than 50%. Therefore all nodes come to use energy fairly. The protocol that we proposed can prove the cluster survival rate about 30%. And CH is more effective because when elect CH replace, response time selects small node.

• Journal of the Korean Institute of Intelligent Systems
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• v.27 no.1
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• pp.1-6
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• 2017

Recent researches on radio frequency energy harvesting networks(RF-EHNs) with limited energy resource like battery have been focusing on the development of a new scheme that can effectively extend the whole lifetime of a network to semipermanent. In order for considerable increase both in the amount of energy obtained from radio frequency energy harvesting and its charging effectiveness, it is very important to design a network that supports energy harvesting and data transfer simultaneously with the full consideration of various characteristics affecting the performance of a RF-EHN. In this paper, we proposes an interference-based charging aware routing protocol(ICARP) that utilizes interference information and charging time to maximize the amount of energy harvesting and to minimize the end-to-end delay from a source to the given destination node. To accomplish the research objectives, this paper gives a design of ICARP adopting new network metrics such as interference information and charging time to minimize end-to-end delay in energy harvesting wireless networks. The proposed method enables a RF-EHN to reduce the number of packet losses and retransmissions significantly for better energy consumption. Finally, simulation results show that the network performance in the aspects of packet transmission rate and end-to-end delay has enhanced with the comparison of existing routing protocols.

• The KIPS Transactions:PartC
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• v.12C no.5 s.101
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• pp.623-632
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• 2005

In ad-hoc network, there is no fixed infrastructure such as base stations or mobile switching centers. The security of ad-hoc network is more vulnerable than traditional networks because of the basic characteristics of ad-hoc network, and current muting protocols for ad-hoc networks allow many different types of attacks by malicious nodes. Malicious nodes can disrupt the correct functioning of a routing protocol by modifying routing information, by fabricating false routing information and by impersonating other nodes. We propose a routing suity mechanism based on one-time digital signature. In our proposal, we use one-time digital signatures based on one-way hash functions in order to limit or prevent attacks of malicious nodes. For the purpose of generating and keeping a large number of public key sets, we derive multiple sets of the keys from hash chains by repeated hashing of the public key elements in the first set. After that, each node publishes its own public keys, broadcasts routing message including one-time digital signature during route discovery and route setup. This mechanism provides authentication and message integrity and prevents attacks from malicious nodes. Simulation results indicate that our mechanism increases the routing overhead in a highly mobile environment, but provides great security in the route discovery process and increases the network efficiency.

• Journal of Digital Convergence
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• v.10 no.9
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• pp.325-332
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• 2012

VANET(Vehicular Ad-hoc Network), which is a technology to create a network among vehicles, decides the route to the destination using information of neighbors within the transmission range as transmission nodes. The existing routing protocol which uses geographical information can cause delay and disconnection of the network when the density of nodes is not high enough to communicate because it only considers the distance of the relay nodes or destination nodes from the source nodes. To solve the problem, this dissertation suggests a routing algorithm based on zones for stable communications among vehicles in the environment of VANET. I minimize the packet loss rate by dividing the city environment into zones and taking into account not only the distance of the destination but also the density of vehicles to choose the best communications environment. This results in a better performance than the established research when the performance evaluation is implemented.

• Electronics and Telecommunications Trends
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• v.14 no.2 s.56
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• pp.69-82
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• 1999

본 고에서는 ATM 기반망의 PNNI 규격인 B-ISUP과 PNNI 규격의 특성을 비교, 분석하고 국내 초고속정보통신망에의 적용성을 분석하였다. 지금까지 WAN을 비롯한 대부분의 ATM 망은 PVC 기반으로 동작하도록 구축, 운용되고 있으나, 한편으로는 사용자가 요구한 다양한 호, 연결의 설정과 해제를 on-demand로 지원할 수 있는 SVC 능력이 요구되고 있는 실정이다. ATM 망에서 SVC 기반 서비스를 제공하기 위해서는 on-demand 호/연결 제어를 위한 UNI와 NNI 신호능력이 제공되어야 한다. ATM 망의 NNI 규격으로는 ITU-T의 B-ISUP 규격과 ATM Forum에서 정의한 PNNI 규격이 고려될 수 있다. B-ISUP과 PNNI 규격은 각기 공중망과 사설망에의 적용을 목표로 만들어졌으므로 두 규격간에는 여러 가지 면에서 서로 상이한 점이 많다. B-ISUP 프로토콜은 동적 라우팅보다는 망운용자의 제어에 의한 계획된 라우팅이 요구되는 망에 적합하며 상대적으로 신뢰성이 우수하고 구조가 단순하다. 이에 비해 PNNI는 토폴로지나 주소체계 등이 자주 바뀌는 경우 자동적 업데이트가 지원되며 QoS 지원이 가능한 동적 라우팅 능력을 갖는 대신에, 상대적으로 복잡하고, 신뢰성 있는 연결 제어가 미흡하다. 본 고에서 분석한 내용은 우리나라 초고속정보통신망의 NNI 규격 적용의 기준 정립을 위한 참고자료로 활용될 수 있다.

• Proceedings of the Korean Information Science Society Conference
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• 2010.06d
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• pp.375-379
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• 2010

Delay-Disruption Tolerant Network(DTN)는 stored-and-forward를 통한 비대칭 통신을 하며 이러한 통신에 적합한 라우팅을 고려하기 위한 연구가 지속적으로 진행 되고 있다. 이러한 라우팅은 Bundle layer에 스토리지를 두어 종 단간 연결이 끊어지더라도 메시지를 보존 할 수 있으며, 현재 이러한 DTN의 특징을 Mobile Ad-hoc Network(MANET)에 적용하여 노드의 이동성을 보다 다이나믹하게 유지 할 수 있도록 하는 연구가 진행되고 있다. 본 논문에서는 이동성이 잦은 지역에서 메시지를 효과적으로 전송하기 위하여 MANET과 DTN 의 특징이 적용된 네트워크 환경에서 AODV 라우팅 테이블 안에 Score를 두어 경로 재탐색이나 메시지 전송이 반복될 경우 Score 값을 기준으로 보다 우월한 노드를 찾을 수 있게 하였다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.1112-1114
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• 2017

The liquid rocket engine determines the routing of the component placement and layout by adapted the cycle method, the hardware configuration, the gimbal type on the functional implementation, and so on. In this paper, the conceptual routing of major pneumatic lines such as helium (He) supply pneumatic line for driving, many purge pneumatic line and main ignition line based on the main components installed in the liquid rocket engine was performed.

• The KIPS Transactions:PartC
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• v.14C no.5
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• pp.403-410
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• 2007

For reliable sensor network communication, secure data transmission mechanisms are necessary. In our work, for secure communication, we cluster the network field in hexagonal shape and deploy nodes according to Gaussian distribution. After node deployment, clusterheads and gateway nodes in each cluster play the role of aggregating and delivering the sensed data with suity information all the way to the base station. Our mechanism decreases the overhead and provides food performance. It also has resilience against various routing attacks.

• The Transactions of the Korea Information Processing Society
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• v.5 no.3
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• pp.763-773
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• 1998

본논문은 TCP/IP를 사용하는 기존의 LAN상에 이동 호스트들이 셀의 형태로 덧붙여진 환경에서 이동 호스트와 고정 호스트간의 지속적인 세션을 지원하는 개선된 IP 체계인 SIMIP을 제안하였다. 이동형 프로토콜 설계시 라우팅 최적화가 매우 중요한 항목이고 이는 이동 호스트의 위치정보 관리방법과 직접적인 관계가 있다. 기존의 아이비엠과 마쓰시다 제안은 이를 집중화하였으며 콜롬비아와 소니제안은 이를 분산화하였다. MH 위치정보를 집중화하면 트라이앵글 문제로 인해 최적의 라우팅 경로를 지원할 수 없으며 집중화된 라우터의 실패 발생시는 위험도가 매우 크다. 반면에 분산화하면 위의 문제들은 해결되지만 캡슐화되는 주소를 찾기위해 CACH 또는 AMT와 같은 복잡한 기법이 요구된다. SIMIP은 MH위치정보를 DMR에 집중화하였으나 DMR 실패 발생시는 복수의 GMR중에서 하나가 자동적으로 DMR로 대체되어 위험도를 최소화시켰고, 'DMR 경로변경'에 의해 최적의 라우팅 경로를 지원하였다는 점에서 다른 제안들과 차이가 있다. 이동에 따른 주소변경을 해결하기 위해 가상네트워크 기법을 적용하였고, 이동 호스트로의 데이터 송신시 디폴트 라우팅 개념을 이용하였고, 이동라우터간 터널링에 IPIP 캡슐화를 사용하였다. SIMIP은 다른 제안에 비해 실용성있고, 신뢰성이 강하며, 구현이 용이하므로 산업계에서 활용가치가 있으리라본다.

• The KIPS Transactions:PartC
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• v.12C no.4 s.100
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• pp.535-542
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• 2005

This paper proposes an on-demand ad hoc routing protocol, Node Density Based Routing (NDBR), which enhances the routing performance applying a new method to establish alternate patlis. It is important to reserve alternate paths for the route from source to destination in mobile ad hoc networks that are susceptible to failure due to the movement or the power exhaustion of mobile nodes. NDBR aims to establish a route that contains more alternate paths toward the destination by involving intermediate nodes with relatively more adjacent nodes in a possible route, and introduces a new routing criterion called 'node density.' This approach can localize the effects of route failures, and reduce control traffic overhead and route reconfiguration time by enhancing the reachability to the destination node without source-initiated route re-discoveries at route failures. This paper describes the route setup procedure using node density and the route re-configuration procedures employing alternate path information at the intermediate nodes. We show the performance of our routing schemes through a series of simulations using the Network Simulator 2 (ns-2).