• Journal of Information Processing Systems
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• v.14 no.5
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• pp.1167-1175
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• 2018

Microarray data plays an essential role in diagnosing and detecting cancer. Microarray analysis allows the examination of levels of gene expression in specific cell samples, where thousands of genes can be analyzed simultaneously. However, microarray data have very little sample data and high data dimensionality. Therefore, to classify microarray data, a dimensional reduction process is required. Dimensional reduction can eliminate redundancy of data; thus, features used in classification are features that only have a high correlation with their class. There are two types of dimensional reduction, namely feature selection and feature extraction. In this paper, we used k-means algorithm as the clustering approach for feature selection. The proposed approach can be used to categorize features that have the same characteristics in one cluster, so that redundancy in microarray data is removed. The result of clustering is ranked using the Relief algorithm such that the best scoring element for each cluster is obtained. All best elements of each cluster are selected and used as features in the classification process. Next, the Random Forest algorithm is used. Based on the simulation, the accuracy of the proposed approach for each dataset, namely Colon, Lung Cancer, and Prostate Tumor, achieved 85.87%, 98.9%, and 89% accuracy, respectively. The accuracy of the proposed approach is therefore higher than the approach using Random Forest without clustering.

• Journal of the Korean Geographical Society
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• v.44 no.5
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• pp.634-646
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• 2009

This paper critically examines cluster dynamics and development in a multi-scalar approach, criticizing both the argument overemphasizing local networks and endogenous development for regional development and the contention highlighting global networks and the role of global players. We argue that state policies, exogenous and direct, play a significant part in cluster dynamics and development especially in the case of Korea where the state government's strong policies have led to rapid industrialization. We analyze multi-scalar factors, especially the government policies at a national level, in the development paths of the three cases including Ulsan automobile cluster, Daedeok research cluster, and Dongdaemun fashion cluster.

• International journal of advanced smart convergence
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• v.7 no.2
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• pp.22-32
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• 2018

In VANET, frequent movement of nodes causes dynamic changes of the network topology. Therefore the routing protocol, which is stable to effectively respond the changes of the network topology, is required. Moreover, the existing cluster-based routing protocol, that is the hybrid approach, has routing delay due to the frequent re-electing of the cluster header. In addition, the routing table of CBRP has only one hop distant neighbor nodes. PCBRP (Paired CBRP), proposed in this paper, ties two clusters in one pair of clusters to make longer radius. Then the pair of the cluster headers manages and operates corresponding member nodes. In the current CBRP, when the cluster header leaves the cluster the delay, due to the re-electing a header, should be occurred. However, in PCBRP, another cluster header of the paired cluster takes the role instead of the left cluster header. This means that this method reduces the routing delay. Concurrently, PCBRP reduces the delay when routing nodes in the paired cluster internally. Therefore PCBRP shows improved total delay of the network and improved performance due to the reduced routing overhead.

• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.638-642
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• 1994

The objectives of this work are to present the dynamic simulation strategy based on cluster-modular approach and to develop a prototype simulator. In addition, methods for the improvement of computational efficiency and applicability are studied. A process can be decomposed into several clusters which consist of strongly coupled units depending upon the process dynamics or topology. The combined approach of simultaneous and sequential simulation based on the cluster structure is implemented within the developed dynamic process simulator, MOSA(Multi Objective Simulation Architecture). Dynamic simulation for a utility plant is presented as a case study in order to prove the efficiency and flexibility of MOSA.

• Journal of the Korean Data Analysis Society
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• v.20 no.6
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• pp.3049-3067
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• 2018

Although there is a growing body of research on organizational commitment profiles based on a person-centered approach, it is not widely applied to the commitment research conducted by Korean organizational scholars yet. Therefore, in this paper, we introduced the concept and analytical methods, such as cluster analysis and latent profile analysis (LPA), of the person-centered approach. In addition, we also performed both cluster analysis and LPA to identify types of organizational commitment profiles of Korean employees based on the combination of affective, continuance and normative commitment on the sample from a range of different fields in South Korea (n = 349). Both analyses extracted two comparable sets of 6 commitment profiles. These six profiles were then contrasted with employee turnover intention. Finally, implications for commitment theory, practices and future research issues were discussed.

• Journal of Communications and Networks
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• v.8 no.3
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• pp.330-338
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• 2006

Many web cache systems and policies concerning them have been proposed. These studies, however, consider large objects less useful than small objects in terms of performance, and evict them as soon as possible. Even if this approach increases the hit rate, the byte hit rate decreases and the connections occurring over congested links to outside networks waste more bandwidth in obtaining large objects. This paper puts forth a client-cluster approach for improving the web cache system. The client-cluster is composed of the residual resources of clients and utilizes them as exclusive storage for large objects. This proposed system achieves not only a high hit rate but also a high byte hit rate, while reducing outgoing traffic. The distributed hash table (DHT) based peer-to-peer lookup protocol is utilized to manage the client-cluster. With the natural characteristics of this protocol, the proposed system with the client-cluster is self-organizing, fault-tolerant, well-balanced, and scalable. Additionally, the large objects are managed with an index based allocation method, which balances the loads of all clients well. The performance of the cache system is examined via a trace driven simulation and an effective enhancement of the proxy cache performance is demonstrated.

• Journal of Information Processing Systems
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• v.14 no.4
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• pp.926-940
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• 2018

In clustering-based approaches, cluster heads closer to the sink are usually burdened with much more relay traffic and thus, tend to die early. To address this problem, distance-aware clustering approaches, such as energy-efficient unequal clustering (EEUC), that adjust the cluster size according to the distance between the sink and each cluster head have been proposed. However, the network lifetime of such approaches is highly dependent on the distribution of the sensor nodes, because, in randomly distributed sensor networks, the approaches do not guarantee that the cluster energy consumption will be proportional to the cluster size. To address this problem, we propose a novel approach called CACD (Clustering Algorithm Considering node Distribution), which is not only distance-aware but also node density-aware approach. In CACD, clusters are allowed to have limited member nodes, which are determined by the distance between the sink and the cluster head. Simulation results show that CACD is 20%-50% more energy-efficient than previous work under various operational conditions considering the network lifetime.

• Journal of Technology Innovation
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• v.14 no.2
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• pp.1-27
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• 2006

This paper rejuvenates the existing discussion on the importance of cluster approach to industry development strategies. Current evidences suggest that the shape of economic policy and practice is changing significantly around the world. Governments continually search for new tools and policy formulas to improve economic performance and create economic prosperity for all citizens. In this context a more proactive and strategic role for government in support of the cluster-based economic development model has emerged. This paper uses Singapore's petrochemical industry as an example to study the cluster approach to industry development. In doing so, there is much optimism to the importance of state and its institutions to play a significant role on industry development. Nevertheless, the study also raises doubts on whether the cluster-based strategy is due to the concept itself or due to other important factors.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.5
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• pp.799-818
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• 2010

In traditional unstructured P2P file sharing network, each peer establishes connections with a certain number of randomly chosen other peers. This would lead to redundant traffic and P2P network partition in mobile ad hoc network (MANET). We propose an approach to construct an efficient unstructured P2P overlay over MANET using underlying cluster-based routing (CBRP). One of the peers in the P2P network is used as a root-peer to connect all peers. Each peer maintains connection with physically closer peers such that it can reach the root-peer. The peer constructs a minimum-spanning tree consisting of itself, its directly connected neighbor peers and 2-hop away neighbor peers to remove far away redundant links and to build an overlay closer to the physical network. Due to on-demand nature of inter-cluster routing of CBRP, the positioning algorithm for MANET is used to retrieve the file by a peer from the source peer via shorter path in the physical network. We can show by simulation that our approach performs better in comparison with the existing approach.

• The Journal of Asian Finance, Economics and Business
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• v.1 no.2
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• pp.15-24
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• 2014

This research investigates the characteristics, principles, advantages, factors and problems of cluster development in Kazakhstan, and identifies the prerequisites, conditions and stages of organizing clusters on the framework of special economic zones. In this research, we used methods, which will allow analyzing of the organization industrial clusters in special economic zones in Kazakhstan. The author studied international experience of cluster development and the efficiency of the use of the model of the "rhombus effect" with account the specific features of interaction between the participants of the cluster, analysis of the legal framework for the formation and development of clusters. These have been identified as the more important or strategically necessary clusters in Kazakhstan: innovation-technological cluster, innovation-education cluster, innovation-petrochemical cluster, innovative-metallurgical cluster, transport and logistics cluster, textile industry cluster, tourism cluster, agro cluster, construction cluster, medical and pharmaceutical cluster. Firstly, the results suggest that the interaction of science, education, business and government in the development and implementation of innovation policy is not sufficiently structured to provide a balanced representation of the interests of the range of various innovative enterprises in Kazakhstan. Secondly, the legal basis of cluster development in Kazakhstan is determined. Need to develop mechanisms for the implementation of promising direction. Thirdly, the clusters can be formed in the existing special economic zones, allowing them to get right to the mass production of high-tech products that are developed.