• Journal of Internet Computing and Services
• /
• v.10 no.3
• /
• pp.51-60
• /
• 2009

This paper proposes a reliable 2-mode authentication framework for probabilistic key pre-distribution in Wireless Sensor Network (WSN) that guarantees the safe defense against different kinds of attacks: Hello flood attacks, Wormhole attacks, Sinkhole attack, location deployment attacks, and Man in the middle attack. The mechanism storing the trust neighbor IDs reduces the dependence on the cluster head and as the result; it saves the power energy for the authentication process as well as provides peer-to-peer communication.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.10 no.9
• /
• pp.4272-4286
• /
• 2016

In resource constrained sensor networks, usage of efficient routing protocols can have significant impact on energy dissipation. To save energy, we propose an energy efficient routing protocol. In our approach, which integrates clustering and routing in sensor networks, we perform network coding during data routing in order to achieve additional power savings in the cluster head nodes. Efficacy of the proposed method in terms of the throughput and end-to-end delay is demonstrated through simulation results. Significant network lifetime is also achieved as compared with other techniques.

• Proceedings of the KAIS Fall Conference
• /
• 2009.12a
• /
• pp.287-289
• /
• 2009

무선 메쉬 네트워크(WMN, Wireless Mesh Network)에서의 전체적인 성능은 채널의 간섭을 최소화함으로써 개선될 수 있다. 본 논문은 3개의 멀티 채널을 지원하는 IEEE 802.11b/g 기반 WMNs를 위해 제안된 클러스터 기반 채널 할당 기법인 CB-CA(Cluster-Based Channel Assignment)[3] 알고리즘을 멀티 라디오 멀티 채널 WMN 환경에 적합하게 개선시키고자 한다. CB-CA 알고리즘에서는 메쉬 라우터들중에 선택된 클러스터 헤드(CH, Cluster Head) 노드들과 클러스터들 간의 에지 게이트웨이(EG, Edge Gateway) 노드들 간에는 모두 동일 채널을 사용함으로써 채널 스캐닝과 채널 스위칭을 수행하지 않는다. 그러나 이러한 모든 CH들과 EG들 간의 동일 채널의 사용은 많은 노드들에서 채널 간섭을 발생 시키는 문제점이 발생한다. 본 논문에서는 이를 해결하기 위하여 송수신 인터페이스를 구분하고 각 인터페이스에서의 채널을 랜덤하게 설정하고 이를 통신 범위 내에 인접한 이웃 클러스터들에게 알림으로써 서로 간섭이 발생하지 않는 채널들이 설정되도록 한다. 이로써 각 클러스터 간의 채널 간섭을 최소화 할 수 있음과 동시에 다중 인터페이스와 다중 채널을 모두 활용할 수 있어서 QoS를 향상시킬 수있다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.22 no.2
• /
• pp.142-147
• /
• 2008

In wireless sensor networks, one of the most important issue is improvement of network lifetime with an efficient energy consumption. we repose effective multi-hop routing algorithm which increases the number of nodes alive at any time. In our algorithm we use the dynamic selection of cluster head and short distance transmission method. We simulated the proposed algorithm by using Network Simulator 2 and compared its performance with LEACH. The experimental result shows that the number of the nodes alive is increased up to 39.71[%] during the simulation time.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2013.07a
• /
• pp.55-56
• /
• 2013

본 논문에서는 센서 클러스터에서 액터를 재배치하기 위하여 센서신호 공통 중첩영역을 추출하는 기법을 분석한다. 기존의 액터 재배치 알고리즘은 CH (Cluster Head)와 동일하게 센서들과 연결을 설정하고자 하는 액터를 CH가 있는 위치로 이동시킨다. 이러한 액터의 이동방법은 액터와 CH를 단순하게 결합하여 액터를 재배치하는 것이며, 액터와 CH가 서로 중첩되거나 충돌하는 문제점을 가지고 있다. 본 논문에서는 센서 클러스터에서 CH와 중첩 또는 충돌 없이 액터를 재배치하기 위해 센서신호 공통 중첩영역을 추출하는 기법을 제시한다.

• Journal of The Korean Astronomical Society
• /
• v.24 no.1
• /
• pp.95-105
• /
• 1991

In the presence of synchrotron losses, diffusion of an ensembel of relativistic particles in an intraculster medium is investigated. The diffusion coefficient in the medium is found to be constrained by $28.8\;{\pm}\;0.4\;{\leq}\;Log\;D\;{\leq}\;30.5\;{\pm}\;0.4\;cm^2s^{-1}$ with the energy dependency of $D_0{\varepsilon}^{\mu}$ of ${\mu}=0.4{\pm}0.2$ as the previous observations suggested. As an important implication of the result, the brightest head-tail radio source NGC 4869, whose radio tail structure is indicative for its orbit within the cluster core, is considered to be the major contributor of particles for the formation of the Coma radio halo.

• Journal of the Korean Society of Costume
• /
• v.49
• /
• pp.65-72
• /
• 1999

The purpose of this study was to investigate the relationships between body-calthexis and clothing image preferences in male college students. The sample included 28 male college students and an instrument was developed based on the previous studies. The statistical analyses used for this study were factor analysis cluster analysis and t-test. The result of factor analysis showed that body-cathexis consisted of four areas of body parts: face/head upper body middle body and lower/total body. Clothing image preferences consisted of 'strong vs weak' 'soft vs hard' 'young vs mature' 'mannis vs feminine' and 'distinguished vs undistinguished' images. Cluster analysis revealed that male college students are segmented into two groups. and the two groups differed in regard to clothing image preferences such as 'strong vs weak' 'young vs mature' and 'mannish vs feminine' images. In addition the two consumer segments were different concerning body-cathexis for middle body and all body areas combined. The consumers who preferred feminine weak and mature clothing images were more satisfied with their middle area of the bodies and all body areas combined.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.8 no.4
• /
• pp.143-149
• /
• 2012

MANET is a network that is a very useful application to build network environment in difficult situation to build network infrastructure. But, nodes that configures MANET have difficulties in data retrieval owing to resources which aren't enough and mobility. Therefore, caching scheme is required to improve accessibility and availability for frequently accessed data. In this paper, we proposed a technique that utilize mobility prediction of nodes to retrieve quickly desired information and improve data availability. Mobility prediction of modes is performed through distance calculation using location information. We used technique which global cluster table and local member table is managed by cluster head to reduce data consistency and query latency time. We compared COCA and CacheData and experimented to confirm performance of proposed scheme in this paper and efficiency of the proposed technique through experience was confirmed.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.7 no.4
• /
• pp.31-37
• /
• 2011

Recently, MANET(Mobile Ad-hoc Network) is developing increasingly in the wireless network. MANET has weakness because phases change frequently and MANET doesn't have middle management system. Every node which consists of MANET has to perform data forwarding, but traceback is not reliable if these nodes do malicious action owing to attack. It also is not easy to find location of attacker when it is attacked as moving of nodes. In this paper, we propose a hierarchical-based traceback method that reduce waste of memory and can manage path information efficiently. In order to manage trace path information and reduce using resource in the cluster head after network is formed to cluster, method which recomposes the path efficiently is proposed. Proposed method in this paper can reduce path trace failure rate remarkably due to moving of nodes. It can also reduce the cost for traceback and time it takes to collect information.

• International Journal of Internet, Broadcasting and Communication
• /
• v.10 no.2
• /
• pp.68-73
• /
• 2018

In recent years, the utilization of the WSN have been rapid. Energy consumption of these networks must be as low as possible. LEACH algorithm is one of the clustering technique. We modify the traditional LEACH algorithm in such way that it will be capable to self-organize large number of nodes and for saving communication resources such as processing time and initiation time. The efficiency of the network highly depends on how the algorithm divides cluster area and selects cluster head. The proposed algorithm can be evaluated through the extensive simulation the result we obtained shows that the life time of a network is increased when energy load is distributed equally among the sensor.