• 디지털융복합연구
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• 제10권1호
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• pp.371-378
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• 2012

센서 네트워크에서는 센서 노드를 통해 개체에 대한 행위, 조건, 위치에 관한 정보를 원격으로 얻을 수가 있다. 일반적으로 센서 노드는 배터리를 이용한 전원 공급이 이루어지므로 매우 제한적이다. 따라서 센서 데이터를 수집하기 위한 효율적인 에너지 관리는 전체 네트워크의 생존기간을 연장하기 위해 필요하다. 본 논문에서는 분산된 센서 노드를 클러스터단위로 자가구성하여 에너지 효율성을 높이는 방법을 제안한다. 제안된 방법은 ANTCLUST를 기반으로 두 개체간의 유사도를 측정한 후 해당 클러스터를 알아내어 자신의 클러스터를 결정하는 방법이다. 제안된 방법은 개미의 colonial closure 모델을 적용한다. 실험결과 기존의 클러스터링 방법보다 27%의 생존 노드 수의 증가를 보였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권4호
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• pp.1437-1459
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• 2020

Wireless Sensor Networks (WSN) is a distributed Sensor network whose terminals are sensors that can sense and check the environment. Sensors are typically battery-powered and deployed in where the batteries are difficult to replace. Therefore, maximize the consumption of node energy and extend the network's life cycle are the problems that must to face. Low-energy adaptive clustering hierarchy (LEACH) protocol is an adaptive clustering topology algorithm, which can make the nodes in the network consume energy in a relatively balanced way and prolong the network lifetime. In this paper, the novel multi-objective LEACH protocol is proposed, in order to solve the proposed protocol, we design a multi-objective coupling algorithm based on bat algorithm (BA), glowworm swarm optimization algorithm (GSO) and bacterial foraging optimization algorithm (BFO). The advantages of BA, GSO and BFO are inherited in the multi-objective coupling algorithm (MBGF), which is tested on ZDT and SCH benchmarks, the results are shown the MBGF is superior. Then the multi-objective coupling algorithm is applied in the multi-objective LEACH protocol, experimental results show that the multi-objective LEACH protocol can greatly reduce the energy consumption of the node and prolong the network life cycle.

• 식물분류학회지
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• 제48권3호
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• pp.153-162
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• 2018

Lespedeza maximowiczii C. K. Schneid. (Fabaceae) is a deciduous shrub which is known to be distributed in the temperate forests of China, Korea and on Tsushima Island of Japan. Due to severe morphological variations within species, numerous examinations have been conducted for Korean L. maximowiczii. However, the morphology of Chinese plants has not been studied as thoroughly, despite doubts about their taxonomy. To clarify this taxonomic issue, we investigated morphological characters and undertook a Bayesian clustering analysis with microsatellite markers. The morphological and genetic traits of Chinese individuals varied considerably from those of typical L. maximowiczii growing in Korea. For example, petals of the former had a different shape and bore long claws, while the calyx lobes were diverged above the middle and the upper surface of the leaflet was pubescent. Their terete buds and spirally arranged bud scales were distinct from those within the series/section Heterolespedeza, which includes L. maximowiczii. Our Bayesian clustering analysis additionally included L. buergeri as an outgroup. Those results indicated that the Chinese samples clustered into a lineage separated from L. maximowiczii (optimum cluster, K = 2), despite the fact that the latter is grouped into the same lineage with L. buergeri. Therefore, we treat those Chinese plants as a new species with the name L. pseudomaximowiczii.

• 한국멀티미디어학회논문지
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• 제10권6호
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• pp.760-769
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• 2007

In this paper, we consider a group mobility model to formulate a clustering mechanism called Dual Coalescent Energy-Efficient Algorithm (DCEE) which is scalable, distributed and energy-efficient for wireless mesh network. The differences of the network nodes will be distinguished to exploit heterogeneity of the network. Furthermore, a topology control, that is, adjusting the transmission range to further reduce power consumption will be integrated with the cluster formation to improve network lifetime and connectivity. Along with network lifetime and power consumption, clusterhead changes will be measured as a performance metric to evaluate the. effectiveness and robustness of the algorithm.

• 전자공학회논문지C
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• 제34C권7호
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• pp.51-60
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• 1997

Prototype based methods are commonly used in cluster analysis and the results may be highly dependent on the prototype used. In this paper, we propose a fuzzy clustering method that involves adaptively expanding convex polytopes. Thus, the dependency on the use of prototypes can be eliminated. The proposed method makes it possible to effectively represent an arbitrarily distributed data set without a priori knowledge of the number of clusters in the data set. Specifically, nonlinear membership functions are utilized to determine whether a new cluster is created or which vertex of the cluster should be expanded. For this, the membership function of a new vertex is assigned according to not only a distance measure between an incoming pattern vector and a current vertex, but also the amount how much the current vertex has been modified. Therefore, cluster expansion can be only allowed for one cluster per incoming pattern. Several experimental results are given to show the validity of our mehtod.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 컴퓨터소사이어티 추계학술대회논문집
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• pp.45-48
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• 2003

We can easily buy network system for high performance micro-processor, progress computer architecture is caused of high bandwidth and low delay time. Coupling PC-based commodity technology with distributed computing methodologies provides an important advance in the development of single-user dedicated systems. Lately Network is joined PC or workstation by computers of high performance and low cost. Than it make intensive that Cluster system is resembled supercomputer. Unix, Linux, BSD, NT(Windows series) can use Cluster system OS(operating system). I'm chosen linux gain low cost, high performance and open technical documentation. This paper is benchmark performance of Beowulf clustering by UltraSPARC-1K(64bit-RISC processor). Benchmark tools use MPI(Message Passing Interface) and NetPIPE. Beowulf is a class of experimental parallel workstations developed to evaluate and characterize the design space of this new operating point in price-performance.

• 산업공학
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• 제21권2호
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• pp.237-246
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• 2008

In today's competitive global environment, technological innovation is an important issue. Many countries are devising national level strategies to further strengthen industrial capacity in support of innovative companies. South Korea is no exception, and multiple strategies are in place to aid innovative development in the private sector. This study postulates that such national level strategies are applied differently depending on the innovation goal pursued by the service sector in Korea. We use data mining methods to test such research hypothesis. Factor analysis is used for clustering of various service companies, while association rule is used in finding the relationship per each cluster. The results show that national level strategies are underutilized and unequally distributed. This may be attributed to the disparity between the demand and needs of the private sector and the opinion of the government, which lead to underutilized and indistinguishable strategies.

• International Journal of Internet, Broadcasting and Communication
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• 제7권1호
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• pp.23-29
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• 2015

Energy constraints of wireless sensor networks are an important challenge. Data Transmission requires energy. Distance between origin and destination has an important role in energy consumption. In addition, the location of base station has a large impact on energy consumption and a specific method not proposed for it. In addition, a obtain model for location of base station proposed. Also a model for distributed clustering is presented by cluster heads. Eventually, a combination of discussed ideas is proposed to improve the energy consumption. The proposed ideas have been implemented over the LEACH-C protocol. Evaluation results show that the proposed methods have a better performance in energy consumption and lifetime of the network in comparison with similar methods.

• 인터넷정보학회논문지
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• 제5권5호
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• pp.69-77
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• 2004

인터넷이 널리 보급되면서 지능형 검색 에이전트들이 사용자의 요구를 만족시키기 위해 일반화되어 사용되고 있다. 그러나 이러한 지능형 멀티에이전트들은 서로 독립적으로 사용되어 멀티에이전트들 간의 분산된 정보를 원활하고 효율적으로 처리하기 위한 상호 협력 작용이 부족해 정보의 신뢰성이 낮고 동적으로 변화하는 분산 환경에 대처하기가 어렵다. 이런 문제를 해결하기 위해 본 논문에서는 멀티에이전트간의 효율적인 상호 협력과 빠른 정보처리를 위해 브로커 에이전트에 에이전시를 생성하고 신경망을 이용해 멀티에이전트들의 에이전시들을 분류하여 더욱 신속·정확한 정보를 사용자에게 제공하도록 한다. 또한 정보의 신뢰성을 위해서 에이전트 관리기법을 제안하여 기존의 검색 시스템이 가지고 있는 정보갱신문제를 향상시키고, 시뮬레이션을 통해 본 연구의 성능을 평가한다.

• 한국정보처리학회논문지
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• 제3권6호
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• pp.1433-1442
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• 1996

자료 분산은 SPMD(Single Program Multiple Data)형태의 병렬성을 제공하는 HPF (High Performance Fortran)의 주기능으로 구현 방법에 따라 컴파일러 성능을 좌우한 다. 본 논문에서는 SPAX(Scalable Parallel Architecture computer based on X-bar network)상에 자료 분산 기능을 제공하기 위한 설계 주안점과 효율적인 모델에 관하 여 기술하였다. SPAX는 분산공유 메모리 (DSM:distributed shared memory)를 사용한 계층적 클러스터링 구조를 가진다. 이러한 메모리 구조에서는 분산 메모리 자료 분산 (DMDD:Distributed Memory Data Distribution)이나 공유 메모리 자료 분산(SMDD: Shared Memory Data Distribution)방법으로는 시스템 가용성을 만족할 수 없다. 그래 서 계층적 마스터-슬래브 형태의 분산공유 메모리 자료분산(DSMDD:Distributed Shared Memory Data Distribution)모델을 설계하였다. 이 모델은 각 노드에 원격 마 스터와 슬래브들을 할당하고 노드내에서는 공유 메모리를 그리고 노드간에는 메세지 전달 인터페이스를 사용한다. 시뮬레이션을 수행한 결과, 시스템 성능 저하를 최소화 하는 노드 크기로 DSMDD를 수행하였을 때 SMDD나 DMDD보다 훨씬 더 효율적이였다. 특 히, 논리적 프로세서 갯수가 많을수록, 분산된 자료들 간의 자료 종속성이 적을수록 성능이 우수하였다.