• Journal of the Korea Society of Computer and Information
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• v.16 no.10
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• pp.165-173
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• 2011

In Mobile Ad-hoc Network(MANET), mobile nodes are operated by limited batteries. Therefore, it is very important to consume the battery power efficiently to prevent termination of the network. In this paper, we propose Energy-aware Dynamic Source Routing(EDSR) which is based on the Dynamic Source Routing(DSR) to increase the packet transmission and lifetime of the network. If the battery power of a node reaches threshold level, then the node gives up the function of relaying to save battery power except as a source and a destination node. While the conventional DSR doesn't consider the battery consumptions of the nodes, EDSR blocks the nodes from relaying whose battery powers are below the threshold level. Simulation results show the proposed EDSR is more efficient in packet transmission and network lifetime through the balanced battery consumption of the mobile nodes.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.11A
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• pp.1064-1072
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• 2005

For the efficient operation of sensor networks, it is very important to design sensor networks for sensors to utilize their energies in very effective ways. Cluster-based routing schemes such as LEACH can achieve their energy efficiencies by delivering data between cluster heads and sensor nodes. In those cluster-based schemes, cluster reconfiguration algorithm is one of the most critical issues to achieve longer operation lifetime of sensor networks. In this paper, we propose a new energy efficient cluster reconfiguration algorithm. Proposed method does not require any location or energy information of sensors, and can configure clusters with fair cluster regions such that all the sensors in a sensor network can utilize their energies equally. The performances of the proposed scheme have been compared with LEACH and LEACH-C.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.8B
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• pp.637-646
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• 2012

Recently, Wireless Sensor Networks (WSNs) are used in many applications. When sensor nodes are deployed on special areas, where humans have any difficulties to get in, the nodes form network topology themselves. By using the sensor nodes, users are able to obtain environmental information. Due to the lack of the battery capability, sensor nodes should be efficiently managed with energy consumption in WSNs. In specific applications (e.g. in intrusion detections), intruders tend to occur unexpectedly. For the energy efficiency in the applications, an appropriate algorithm is strongly required. In this paper, we propose tree-based routing algorithm for the specific applications, which based on the intrusion detection. In addition, In order to decrease traffic density, the proposed algorithm provides enhanced method considering link cost and load balance, and it establishes efficient links amongst the sensor nodes. Simultaneously, by using the proposed scheme, parent and child nodes are (re-)defined. Furthermore, efficient routing table management facilitates to improve energy efficiency especially in the limited power source. In order to apply a realistic military environment, in this paper, we design three scenarios according to an intruder's moving direction; (1) the intruder is passing along a path where sensor nodes have been already deployed. (2) the intruders are crossing the path. (3) the intruders, who are moving as (1)'s scenario, are certainly deviating from the middle of the path. In conclusion, through the simulation results, we obtain the performance results in terms of latency and energy consumption, and analyze them. Finally, we validate our algorithm is highly able to adapt on such the application environments.

• Journal of the Korea Society of Computer and Information
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• v.17 no.1
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• pp.61-69
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• 2012

Smart Grid is the next-generation intelligent power grid that maximizes energy efficiency with the convergence of IT technologies and the existing power grid. Smart Grid is created solution for standardization and interoperability. Smart Grid industry enables consumers to check power rates in real time for active power consumption. It also enables suppliers to measure their expected power generation load, which stabilizes the operation of the power system. Smart industy was ecolved actively cause Wireless communication is being considered for AMI system and wireless communication using ZigBee sensor has been applied in various industly. In this paper, we proposed efficient addressing scheme for improving the performance of the routing algorithm using ZigBee in Smart Grid environment. A distributed address allocation scheme used an existing algorithm has wasted address space. Therefore proposing x, y coordinate axes from divide address space of 16 bit to solve this problem. Each node was reduced not only bitwise but also multi hop using the coordinate axes while routing than Cskip algorithm. I compared the performance between the standard and the proposed mechanism through the numerical analysis. Simulation verify performance about decrease averaging multi hop count that compare proposing algorithm and another. The numerical analysis results show that proposed algorithm reduce multi hop than ZigBee distributed address assignment and another.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.5B
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• pp.247-256
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• 2007

In this paper, we propose Geographical Back-off Routing (Geo-Back Routing) protocol for wireless sensor networks. Geo-Back uses the positions of nodes, a packet's destination and a optimal back-off time to make the packet forwarding decisions using only source and destination's location information without information about neighbor nodes' location or the number of one hop neighbor nodes. Under the frequent topology changes in WSNs, the proposed protocol can find optimal next hop location quickly without broadcast algorithm for update. In our analysis, Geo-Back's scalability and better performance is demonstrated on densely deployed wireless sensor networks.

• Journal of Internet Computing and Services
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• v.9 no.4
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• pp.43-50
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• 2008

Various studies are being conducted to achieve efficient routing and reduce energy consumption in wireless sensor networks where energy replacement is difficult. Among routing mechanisms, the clustering technique has been known to be most efficient. The clustering technique consists of the elements of cluster construction and data transmission. The elements that construct a cluster are repeated in regular intervals in order to equalize energy consumption among sensor nodes in the cluster. The algorithms for selecting a cluster head node and arranging cluster member nodes optimized for the cluster head node are complex and requires high energy consumption. Furthermore, energy consumption for the data transmission elements is proportional to $d^2$ and $d^4$ around the crossover region. This paper proposes a means of reducing energy consumption by increasing the efficiency of the cluster construction elements that are regularly repeated in the cluster technique. The proposed approach maintains the number of sensor nodes in a cluster at a constant level by equally partitioning the region where nodes with density considerations will be allocated in cluster construction, and reduces energy consumption by selecting head nodes near the center of the cluster. It was confirmed through simulation experiments that the proposed approach consumes less energy than the LEACH algorithm.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.377-380
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• 2010

MANET(Mobile Ad-hoc Network) has been proposed as a infrastructure-less network using distributed algorithm for remote environment monitoring and control. The mobility of MANET would make the topology change frequently compared with a static network and a node is resource-constrained. Hence, to improve the routing protocol in MANET, energy efficient routing protocol is required as well as considering the mobility would be needed. In this paper, we extend RODMRP(Resilient Ontology-based Dynamic Multicast Routing Protocol) structure by a modifying the level of cluster. We call this network protocol CACH-RODMRP. Our contribution consists estimating the optimal level of clustering depth with considering node position and reducing the network residual energy. The simulation results of proposal algorithm show that the energy is significantly reduced compared with the previous clustering based routing algorithm for the MANET.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06a
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• pp.355-358
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• 2011

무선 센서 네트워크의 효율적인 에너지 사용은 무선 센서 네트워크의 수명과 관련된 중요한 요소이다. 무선센서 네트워크의 역동적인 환경에서는 전력량, 간섭 요소를 고려한 신호의 세기, 노드간의 거리 등의 특성을 고려하여 최적의 경로를 선택하는 것은 에너지 사용량에 많은 영향을 준다. TORA(Temporally-Ordered Routing Algorithm)는 이동성이 심한 무선 네트워크 환경에 적합하게 설계되어 있고 다중경로를 이용하여 링크 단절 시 빠른 복구가 가능한 장점이 있지만, 네트워크 생존의 측면에서 전력 사용의 효율성을 개선 및 보완할 필요가 있다. 본 논문에서는 TORA의 다중 경로 중에서 최적의 경로를 선택하는 방법에 대해서 논하고자 한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.11A
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• pp.1120-1129
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• 2006

It is very important to maximize the battery durability of mobile host in wireless ad-hoc network environments, because it extends the durability and Performance of the system. Since mobile hosts play a routing role, the network structure and the location of mobile hosts create a difference of energy consumption of mobile hosts. In this paper, each mobile host maintains energy tree and evaluates the amount of the energy of the neighboring mobile hosts by using message tree packet by periods. When mobile host sets up a routing path to send a packet, it selects the most proper path in order to consume energy effectively by using energy tree and breadth first search. In this paper, we suggest that, in wireless ad-hoc network environments, if each mobile host consumes balanced energy, mobile hosts of which energy capacity is limited can work as long as it can. Therefore, the durability and performance of the system can be extended.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.306-309
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• 2009

MANET(Mobile Ad-hoc Network)은 기간망에 의존하지 않는 이동 노드들로 구성된 자율망 또는 추론망 토폴로지에 의한 멀티홉 무선 네트워크이다. MANET을 구성하는 각 노드의 이동성, 속도 그리고 에너지와 같은 다양한 속성정보는 망의 특징과 운영을 결정하는 요인이다. 특히 망의 운영상, 전송 대역폭과 에너지 사용에 따른 제약을 가지며 이러한 특징을 고려한 라우팅 프로토콜의 설계 및 하드웨어 개발이 중요하게 요구된다. 본 논문에서는 계층적 클러스터 구조의 MANET 환경에서 노드의 에너지 속성과 네트워크의 트래픽 상태를 고려한 적응적 시간차 노드관리 기법인 ATICC(Adaptive Time Interval Clustering Control)을 제안한다. 제안된 ATICC은 시간차 노드 관리기법인 TICC(Time Interval Clustering Control)[1]에 기반하며 노드에 최적화된 Active/Sleep, Idle Listening 상태를 적응적으로 설정한 후 패킷을 전송함으로서 계층적 클러스터 내의 각 노드의 균형적인 에너지 소모를 이루는 에너지 효율적인 방식이다. 제안한 노드관리 방법은 기존의 LEACH, TICC과 비교 실험하고 그 성능을 검증하였다. 실험 결과, 제안한 노드관리 방법이 노드별 에너지 소모량을 줄였으며 전체 네트워크의 생존시간을 연장함으로서 기존의 방법 보다 우수함을 확인하였다.