• International Journal of Computer Science & Network Security
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• v.23 no.9
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• pp.134-140
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• 2023

The distributed system is playing a vital role in storing and processing big data and data generation is speedily increasing from various sources every second. Hadoop has a scalable, and efficient distributed system supporting commodity hardware by combining different networks in the topographical locality. Node support in the Hadoop cluster is rapidly increasing in different versions which are facing difficulty to manage clusters. Hadoop does not provide Node management, adding and deletion node futures. Node identification in a cluster completely depends on DHCP servers which managing IP addresses, hostname based on the physical address (MAC) address of each Node. There is a scope to the hacker to theft the data using IP or Hostname and creating a disturbance in a distributed system by adding a malicious node, assigning duplicate IP. This paper proposing novel node management for the distributed system using DNA hiding and generating a unique key using a unique physical address (MAC) of each node and hostname. The proposed mechanism is providing better node management for the Hadoop cluster providing adding and deletion node mechanism by using limited computations and providing better node security from hackers. The main target of this paper is to propose an algorithm to implement Node information hiding in DNA sequences to increase and provide security to the node from hackers.

• Journal of KIISE:Computer Systems and Theory
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• v.30 no.10
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• pp.533-543
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• 2003

With the increase of interests in cluster, there have been a number of research efforts to address the high availability issues on cluster. However, there are no kernel-level group communication systems to support the development of kernel-level application programs and it is not easy to use traditional user-level group communication systems for the kernel-level applications. This paper presents the design and implementation issues of KCGCS(Kernel-level Cluster Group Communication System), which is a kernel-level group communication module for linux cluster. Unlike traditional user-level group communication systems, the KCGCS uses light-weight heartbeat messages and a ring-based heartbeat mechanism, which allows users to implement scalable failure detection mechanisms. Moreover, the KCGCS improves the reliability by using distributed coordinators to maintain membership information.

• Journal of KIISE:Computer Systems and Theory
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• v.29 no.10
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• pp.539-549
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• 2002

PC cluster-based Information Retrieval (IR) systems improve their performances by parallel processing of query terms using cluster nodes. However TCP/IP based communication used to exchange data between cluster nodes prevents the performance from being improved further. The user-level communication mechanisms solve the problem by eliminating the time-consuming kernel access in exchanging data between cluster nodes. The Virtual Interface Architecture (VIA) is one of the representative user-level communication mechanisms which provide low latency and high bandwidth. In this paper, we propose a VIA-based parallel IR system on a PC cluster. The IR system is implemented using the following three communication methods: Sealable Coherent Interface (SCI) based VIA, MPI on SCI based VIA, MPI on Fast Ethernet based VIA. Through experiments, the performances of the three methods are analyzed in various aspects.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.37 no.6
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• pp.445-452
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• 2019

In this study, parallel processing codes of k-means clustering algorithm were developed and implemented in a PC-cluster for unsupervised classification of large satellite images. We implemented intra-node code using multicores of CPU (Central Processing Unit) based on OpenMP (Open Multi-Processing), inter-nodes code using a PC-cluster based on message passing interface, and hybrid code using both. The PC-cluster consists of one master node and eight slave nodes, and each node is equipped with eight multicores. Two operating systems, Microsoft Windows and Canonical Ubuntu, were installed in the PC-cluster in turn and tested to compare parallel processing performance. Two multispectral satellite images were tested, which are a medium-capacity LANDSAT 8 OLI (Operational Land Imager) image and a high-capacity Sentinel 2A image. To evaluate the performance of parallel processing, speedup and efficiency were measured. Overall, the speedup was over N / 2 and the efficiency was over 0.5. From the comparison of the two operating systems, the Ubuntu system showed two to three times faster performance. To confirm that the results of the sequential and parallel processing coincide with the other, the center value of each band and the number of classified pixels were compared, and result images were examined by pixel to pixel comparison. It was found that care should be taken to avoid false sharing of OpenMP in intra-node implementation. To process large satellite images in a PC-cluster, code and hardware should be designed to reduce performance degradation caused by file I / O. Also, it was found that performance can differ depending on the operating system installed in a PC-cluster.

• Journal of Korea Spatial Information System Society
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• v.6 no.1 s.11
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• pp.3-17
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• 2004

With the rapid growth of the Internet geographic information services through the WWW such as a location-based service and so on. Web GISs (Geographic Information Systems) have also come to be a cluster-based architecture like most other information systems. That is, in order to guarntee high quality of geographic information service without regard to the rapid growth of the number of users, web GISs need cluster-based architecture that will be cost-effective and have high availability and scalability. This paper proposes the design of the cluster-based web GIS with high availability and scalability. For this, each node within a cluster-based web GIS consists of main memory spatial databases which accomplish role of caching by using data declustering and the locality of spatial query. Not only simple region queries but also the proposed system processed spatial join queries effectively. Compare to the existing method. Parallel R-tree spatial join for a shared-Nothing architecture, the result of simulation experiments represents that the proposed spatial join method achieves improvement of performance respectively 23% and 30% as data quantity and nodes of cluster become large.

• Korean Journal of Computational Design and Engineering
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• v.15 no.3
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• pp.167-177
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• 2010

In recent years, the use of high-resolution tiled display system which does not have restrictions on the size of the screen and implements various layout of tile is increasing in order to evaluate the digital mock-up in physical scale or explore large engineering data set in detail. In this study, we developed multi-channel distributed visualization system which provides a virtual reality-based visual contents using 3D open-source graphics engine. Efficient data structures and exchange methods were proposed as a scene synchronization technology in PC cluster environments. DLP-Cube based tiled visualization system which provides $5{\times}2$ layout of display wall was developed and we validated our approach using this system. In addition, we introduced integrated control program that administrates PC cluster environment in remote and controls the layout of display channels.

• Journal of the Korean Data and Information Science Society
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• v.18 no.1
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• pp.161-174
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• 2007

In this paper, we propose a high performance database cluster system called HyperDB to process OLAP queries efficiently. HyperDB is a virtual database system running on top of internet-connected PCs; the PCs are used for their own purpose at ordinary times, but they are able to participate in the database cluster system at non-office hours. We propose fully logical replication technique and optimal parallel intra-query routing technique for extensibility and performance. Experiment for TPC-R benchmark shows significant performance upgrade compared with conventional approaches.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.3
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• pp.453-460
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• 2010

For high quality image acquisition, compensating air-vehicle motion is essential for airborne SAR system. This paper describes a timing control based motion compensation method for airborne SAR system. Efficient timing control is critical for SAR system since it maintains many timing signals and timing setting for the signals should be updated frequently. This paper proposes Timing Cluster method as an efficient means for timing control of SAR system. Moreover, this paper suggests a simple and efficient method to compensate air-vehicle motion based on the Timing Cluster method. Timing Cluster method enables SAR system to control the timing in a timing noncritical way just maintaining little amount of information.

• The Journal of Fisheries Business Administration
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• v.40 no.3
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• pp.1-28
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• 2009

In recent, the Korean fisheries industry face an overall crisis. Annual fish catch is continuously decreasing for last two decades even though various programs to improve fish population. Moreover, domestic fish market is more and more occupied by imported cheap fish products from abroad due to the consequence of open economic policy, FTA and WTO/DDA entente. Under the circumstances, this study aims to examine the potential for building fisheries cluster as a policy tool to promote fisheries and fisheries-associated industries in Korea. To achieve this goal, the authors firstly reviewed the theoretical concept of Industrial Cluster in the evolutionary economics point of view, secondly, analyzed the main components of Porterian Cluster(or innovation cluster), thirdly, derived the key reasons to induce the improvement of productivity within the cluster network system and lastly evaluated fisheries capability and industrial infrastructures of each province as a basic condition to build a fisheries cluster. The result of the study demonstrates the voluntary accumulation of fish products and processing techniques in Korea, however, it is not enough to make up a Porterian innovation. Therefore, the present is most opportune for applying fisheries cluster as a strategic policy tool. Government supports to establish innovation cluster for fisheries may contribute both fisheries industry and local economy by developing the latent capacity of fisheries and helping concentrate innovation capabilities.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.571-571
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• 2012

We discovered the formation of C60 aggregates in solution by means of photoluminescence spectroscopic study on C60 in solutions. From the in-depth investigation of temperature dependence of the luminescence of C60 in toluene, benzene and CS2 solutions, we reported that the C60 aggregates are formed during cooling at the freezing temperature of these solvents. Furthermore, the C60 aggregates can be changed to stable structures by irradiating with UV pulse-laser (Nd:YAG laser, 355nm). As a consequence, we could obtain nano-scale photo-polymerized C60 clusters, which appear as round-shaped nano- scale particles in high resolution transmission electron-microscopy (HRTEM) images. However, the yield of the nano-scale C60 clusters obtained by this method is too small. So we designed and developed a system to obtain C60 cluster of macroscopic quantity by using ultrasonic nebulizer. In this system, C60 solution was vaporized to several micro-sized droplets in vacuum, resulting in the formation of C60 aggregates by evaporating solvent (toluene). The system was invented to produce nano-scale carbon clusters by the irradiation of UV light upon C60 aggregates in vacuum. We have characterized the products, C60 cluster, obtained from the system by using UV absorption spectra and HPLC spectra. Although the products have a possibility of inclusion various forms of C60 cluster, results support that the product formed from the system by using vaporizer method establishes a new method to obtain C60 cluster in macroscopic quantity. In the presentation, the details of the system and the results of characterization are reported.