• Agribusiness and Information Management
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• 제7권1호
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• pp.21-36
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• 2015

This study aims to analyze the differences of ginseng product consumers and segment Korean fresh ginseng and red ginseng root markets based on attributes for the purchase. As a result of analyzing survey data, the red ginseng root consumers had different aspects from fresh ginseng consumers. According to the result of cluster analysis, the fresh ginseng consumers were subdivided into three segments (safety-oriented consumption cluster, label centered consumption cluster, and high involvement consumption cluster), while the red ginseng root consumers were subdivided into four segments (convenience-oriented consumption cluster, high involvement consumption cluster, raw material's safety-oriented cluster, and raw material's information importance cluster). ANOVA and Crosstab were conducted to investigate characteristics of each cluster.

• 천문학회보
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• 제41권2호
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• pp.60.3-61
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• 2016

Galaxy morphology involves complex effects from both secular and non-secular evolution of galaxies. Although it is a final product of galaxy evolution, it gives a clue to the processes that the a galaxy has gone through. Galaxy clusters are the sites where the most massive galaxies are found, and thus the most dramatic merger histories are embedded. Our deep imaging program (${\mu}{\sim}28\;mag\;arcsec^{-2}$), KASI-Yonsei Deep Imaging Survey for Clusters (KYDISC), targets 14 Abell clusters at z = 0.016 - 0.14 using IMACS/Magellan telescope and MegaCam/CFHT to investigate cluster galaxies especially on low surface brightness features related to galaxy interactions. We visually classify galaxy morphology based on criteria related to secular or merger related evolution and find that the morphological mixture of galaxies varies considerably from cluster to cluster. Moreover it depends on the characteristics (e.g. cluster mass) of cluster itself which implies that environmental effects in cluster scale is also an important factor to the evolution of galaxies together with intrinsic (secular) and galaxy merger. Our deep imaging survey for morphological inspection of cluster galaxies with low surface brightness is expected to be a useful basis to understand the nature of cluster galaxies and their internal/external evolutionary path.

• 한국컴퓨터정보학회논문지
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• 제24권1호
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• pp.1-7
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• 2019

In this paper, we implemented a Wi-Fi based cluster system using raspberry pi for multidisciplinary education. The cluster implementation on the desktop was more difficult to maintain the complexity, big size, high price, power consumption as the number of nodes increased. In this paper, we implemented a cluster using Raspberry Pi, which is developed for educational purposes, to reduce the cost of connecting nodes. In addition, the complexity of system construction is reduced by replacing the connection between each node with Wi-Fi. Also, the inconvenience of configuration due to node increase was reduced. It is expected that the implementation of the cluster will be a good alternative in the educational environment where distributed processing and parallel processing are performed in the embedded environment. Also, it is confirmed that it can be applied to the multidisciplinary education.

• Journal of Veterinary Science
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• 제22권6호
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• pp.88.1-88.6
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• 2021

Toxoplasma gondii consists of three genotypes, namely genotype I, II and III. Based on its virulence, T. gondii can be divided into virulent and avirulent strains. This study intends to evaluate an alternative method for predicting T. gondii virulence using hierarchical cluster analysis based on complete coding sequences (CDS) of sag1, gra7 and rop18 genes. Dendrogram was constructed using UPGMA with a Kimura 80 nucleotide distance measurement. The results showed that the prediction errors of T. gondii virulence using sag1, gra7 and rop18 were 7.41%, 6.89% and 9.1%, respectively. Analysis based on CDS of gra7 and rop18 was able to differentiate avirulent strains into genotypes II and III, whereas sag1 failed to differentiate.

• 전자공학회논문지CI
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• 제45권6호
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• pp.77-86
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• 2008

기존의 클러스터 라우팅 방식은 클러스터 헤드를 선출하여 클러스터 내의 멤버 노드들로부터 정보를 수집하고 압축하여 기지국에 전송함으로써 에너지 효율을 높일 수 있는 대표적인 방식이다. 그러나 클러스터 형성 단계 중 매 라운드마다 셋업 단계에서 선출된 클러스터 헤드와 클러스터 내의 멤버 노드들 간의 빈번한 정보 교환으로 인해 발생하는 불필요한 에너지 소모는 클러스터 라우팅 방식이 해결해야 하는 과제이다. 본 논문에서는 셋업 단계에서의 선출된 클러스터 헤드와 기존의 클러스터 헤드 사이에 변경되지 않는 중첩된 영역에 속한 멤버 노드들을 계산함으로써, 중첩된 멤버 노드들의 셋업 단계에서의 불필요한 송수신 횟수를 줄여 정보 교환을 최소화하였다. 또한 최적의 클러스터 구성을 위해 상위 클러스터 헤드의 방향성을 고려하였다. 따라서 셋업 단계에서의 소모되는 에너지를 절약하여 안정 단계에서 효율적으로 사용함으로써, 에너지의 효율적인 사용과 전체적인 네트워크의 생존시간을 증가시키고자 하며, 전체 네트워크내의 멤버들에게 클러스터 헤드가 될 수 있는 균등한 기회를 주고자 하는 클러스터 헤드 선출 기법을 제안한다.

• 천문학회보
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• 제38권2호
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• pp.48.1-48.1
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• 2013

We present galaxy luminosity functions (LFs) of subgroups in the Ursa Major cluster. The membership of galaxies is determined by radial velocities which are compiled from the SDSS and NED. We found that the faint end slope (${\alpha}$) of the LF of all sample galaxies in Ursa Major is ${\alpha}=-1.13$. This is consistent with previous result, but shallower than that of the Virgo cluster. Interestingly, the subgroups in Ursa Major show different slopes in their LFs. The NGC 3992 and NGC 4111, the massive subgroups in the Ursa Major cluster, exhibit steep slopes of their LFs comparable to that of the Virgo cluster. On the other hand, less massive group (NGC 3877) shows a very shallow slope of -0.84. Based on the results, we discuss the evolution of galaxies and the assembly history of the Ursa Major cluster.

• Journal of Communications and Networks
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• 제14권4호
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• pp.443-450
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• 2012

As for cluster-based wireless sensor networks (WSNs), cluster lifetime is one of the most important subjects in recent researches. Besides reducing the energy consumptions of the clusters, it is necessary to make the clusters achieve equal lifetimes so that the whole network can survive longer. In this paper, we focus on the cluster lifetimes in multi-hop WSNs with cooperative multi-input single-output scheme. With a simplified model of multi-hop WSNs, we change the transmission schemes, the sizes and transmission distances of clusters to investigate their effects on the cluster lifetimes. Furthermore, linear and uniform data aggregations are considered in our model. As a result, we analyze the cluster lifetimes in different situations and discuss the requirements on the sizes and transmission distances of clusters for equal lifetimes.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권7호
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• pp.1293-1310
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• 2011

A simple modification of well known Low Energy Adaptive Clustering Hierarchy (LEACH) protocol is proposed to exploit cooperative diversity. Instead of selecting a single cluster-head, we propose M cluster-heads in each cluster to obtain a diversity of order M. The cluster-heads gather data from all the sensor nodes within the cluster using same technique as LEACH. Cluster-heads transmit gathered data cooperatively towards the destination or higher order cluster-head. We propose a code combining based cooperative diversity protocol which is similar to coded cooperation that maximizes the performance of the proposed cooperative LEACH protocol. The implementation of the proposed cooperative strategy is analyzed. We develop the upper bounds on bit error rate (BER) and frame error rate (FER) for our proposal. Space time block codes (STBC) are also a suitable candidate for our proposal. In this paper, we argue that the STBC performs worse than the code combining cooperation.

• World Technopolis Review
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• 제4권2호
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• pp.87-103
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• 2015

This paper aims to explore how firms develop and grow in regional clusters based in a developing country. The argument is that start-ups / small and large firms are able to grow by developing linkages or networks for resources within clusters - and this tenet is based on studies of firms that are based from such clusters as Silicon Valley in the US, Cambridge in UK and other clusters from which have evolved over long periods of time. Most of the time we hear narratives from the developed world where there are brownfield cluster development efforts. In developing countries governments are making efforts to develop clusters from scratch - which in this paper we term as greenfield cluster versus a brownfield development, which is where the cluster is developed based on existing and new organisations in a region. In this paper, we believe the context of clusters can be important in determining the way firms develop linkages for their growth - and we look at two contexts in Malaysia ie. A greenfield cluster and a brownfield cluster. The paper presents findings from case studies of firms in a greenfield cluster (Cyberjaya) and a brown field cluster (Penang) in Malaysia. The cases reveal fairly different approaches to development of linkages or networks, which we hope will provides insights to cluster development officials and policy makers and implications to researchers for developing studies of clusters and innovation systems.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권2호
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• pp.680-699
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• 2015

The use of web service has been increased rapidly, with an increase in the number of available services, finding the exact service is the challenging task. Service discovery is the most significant job to complete the service discoverers needs. In order to achieve the efficient service discovery, we focus on designing a cluster based service discovery model for service registering and service provisioning among all mobile nodes in a mobile ad hoc network (MANETs). A dynamic backbone of nodes (i.e. cluster heads) that forms a service repository to which MANET nodes can publish their services and/or send their service queries. The designed model is based on storing services with their service description on cluster head nodes that are found in accordance with the proposed cluster head election model. In addition to identifying and analyzing the system parameters for finding the effectiveness of our model, this paper studies the stability analysis of the network, overhead of the cluster, and bandwidth utilization and network traffic is evaluated using analytic derivations and experimental evaluation has been done.