• Journal of KIISE:Information Networking
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• v.32 no.4
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• pp.471-482
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• 2005

The high-speed network permits Grid computing to handle large problem of management areas and share various computational resources. As there are many resources and changes of them in Grid computing, the resources should be detected effectively and matched correctly with tasks to provide high performance. In this paper, we propose a mechanism that maximizes the performance of Grid computing systems. According to a priority, grade and site of heterogeneous resources, we assign tasks to those resources. Initially, a volunteer's priority and ranking are determined by static information like as CPU speed, RAM size, storage size and network bandwidth. And then, the rank of resources is decided by considering dynamic information such as correctness, response time, and error rate. We find that overall Grid system performance is improved and high correctness using resource reallocation mechanism is achieved.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.10
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• pp.43-51
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• 2009

In this paper, we present an integrated management system for WSNs (Wireless Sensor Networks). Each sink node of heterogeneous sensor networks is connected with a gateway. By supporting various hardware platforms and networking models, the gateway is able to collect management information from one or more WSNs and store it in a MIB (Management Information Base). The management system obtains management information from the MIB of the gateway by SNMP (Simple Network Management Protocol) and analyzes it. A manager can have access to the management system through the Web wherever the Internet is available and manage WSNs as well as sensor nodes. We implemented the proposed management system and our findings revealed the practicality of this system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.4
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• pp.395-403
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• 2016

This paper introduces a multi-cell search method for heterogeneous networks (HetNet), in which user equipments need to search multiple cells in its vicinity simultaneously. Due to the difficulty of acquiring channel informations for multiple cells, a non-coherent approach is preferred. In this paper, a non-coherent single-cell search scheme using a weighted vector is proposed, and the successive interference cancellation based multi-cell search algorithm is devised. In order to improve cell search performance, the weighted vector is designed in a way to exploit the general characteristic of wireless channel. Based on the fact that the performance of the proposed single-cell search scheme deviates slowly from the one using the optimal weighted vector, a universal weighted vector is also proposed, which shows the performance close to the optimal ones for various channel environments and signal-to-noise ratio regimes. Simulation results confirm that the proposed multi-cell search algorithm is capable of identifying cells more accurately with the help of the proposed single-cell search scheme, and can detect the remaining cells more effectively by removing the signals of the identified cells from the received signal.

• Language and Information
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• v.14 no.1
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• pp.165-196
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• 2010

The primary goal of this paper is to propose methods of enriching two heterogeneous ontologies: Sejong Semantic Classes (SJSC) and KorLexNoun 1.5 (KLN). In order to achieve this goal, this study introduces the pros and cons of two ontologies, and analyzes the error patterns found during the fine-grained manual mapping processes between them. Error patterns can be classified into four types: (1) structural defectives involved in node branching, (2) errors in assigning the semantic classes, (3) deficiency in providing linguistic information, and (4) lack of the lexical units representing specific concepts. According to these error patterns, we propose different solutions in order to correct the node branching defectives and the semantic class assignment, to complement the deficiency of linguistic information, and to increase the number of lexical units suitably allotted to their corresponding concepts. Using the results of this study, we can obtain more enriched ontologies by correcting the defects and errors in each ontology, which will lead to the enhancement of practicality for syntactic and semantic analysis.

• The Transactions of the Korea Information Processing Society
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• v.4 no.11
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• pp.2671-2678
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• 1997

The MHEG-5 standard defines representation of multimedia and hypermedia information. The MHEG-5 can make it possible to interchange and present information between heterogeneous networked environment. Also, it can provide real-time user interaction. MHEG-5 object generating is the essential requirements for the MHEG-5 applications, In this paper, we designed encoding/decoding class library for the MHEG-5 objects. We can use it for the interchange on the network. The designed class library can provide base technology for the MHEG-5 based distributed multimedia and hypermedia services on the networked environment.

• The KIPS Transactions:PartC
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• v.15C no.5
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• pp.367-374
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• 2008

To realize the voice privacy between CDMA mobile phone and PSTN terminal, the voice frames shall be transmitted transparently between the heterogeneous networks. For satisfying this requirement, we propose the method which transmits voice frames using the CDMA circuit data channel in real time. In this paper we analyze the causes of voice delay which occurs during voice transmission using circuit data channel. And in order to overcome this kind of delay, the technique controlling the TCP control flag and the variable audio block construction algorithm according to the vocoder output rate are proposed. As a result of experimenting by applying the proposed method, we confirmed that the transit delay was improved with about average 70%.

• Proceedings of the Korea Information Assurance Society Conference
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• 2004.05a
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• pp.199-204
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• 2004

Operating systems and application programs have security vulnerabilities derived from the software development process. Recently, incident cases related with the abuses of these vulnerabilities are increasing and the damages caused by them are becoming very important security issues all over the nations. Patch management is one of the most important processes to fix vulnerabilities of softwares and to ensure a security of systems. Since an institute or a company has distributed hierarchical and heterogeneous systems, it is not easy to update patches promptly. In this paper, we propose patch management framework to safely distribute and install the patches on Windows, Linux, and Solaris client systems. Besides, we censidered extensibility and hierarchical structure for our patch management framework to support large scaled network environment.

• Proceedings of the IEEK Conference
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• 2009.05a
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• pp.290-292
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• 2009

With advance in technologies for wireless sensor networks(WSNs), 2.4 GHz band has become gradually attractive due to increase in low-power wireless communication devices. Especially ZigBee(IEEE 802.15.4-based) technology whose frequency band includes the 2.4GHz industrial, scientific and medical band providing nearly worldwide availability has been universally applicable to a various remote monitoring system and applications related home network system. However network throughput of these systems is significantly deteriorated due to this ISM band is a license-exemption used in a variety of low-power wireless communication devices. For instance, other IEEE 802 wireless standards such as Bluetooth, WLAN, Wi-Fi and others cause radio interference to ZigBee. The experiments was carried out to analyze radio frequency interference between heterogeneous devices using ISM bands to improve the limited frequency utility factor. Finally this paper suggests a frequency hopping-based adaptive multi-channel methods to decrease interference with empirical results.

• Journal of the Korea Computer Industry Society
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• v.5 no.2
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• pp.251-260
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• 2004

As the importance and the need for network security is increased, many organization uses the various security systems. They enable to construct the consistent integrated security environment by sharing the vulnerable information among firewall, intrusion detection system, and vulnerable scanner. We construct the integrated security simulation environment that can be used by some security system model. In this paper, we have designed and constructed the general simulation environment of network security model composed of multiple IDSs agent and a firewall agent which coordinate by CNP (Contract Net Protocol). The CNP, the methodology for efficient integration of computer systems on heterogeneous environment such as distributed systems, is essentially a collection of agents, which cooperate to resolve a problem. We compare the selection algorithm in the CPN with the Fuzzy Controller for the effective method to select the agents.

• Journal of Communications and Networks
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• v.4 no.4
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• pp.336-343
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• 2002

A major challenge for next generation mobile communication is capturing the system architecture’s complexity with all its internal and external dependencies. Seamless integration of heterogeneous environments in all system parts is a key requirement. Moreover, future systems have to consider the different evolution cycles of individual system parts. Among those, services are expected to change the fastest. With respect to these considerations, we propose an overall architecture for next generation mobile communication systems. It covers all system parts from wireless transmission to applications including network and middleware platform. Our approach focuses on adaptability in terms of recon- figurability and programmability to support unanticipated system evolution. Therefore, we consider abstraction layers which consist of adaptable cooperating components grouped by open platforms rather than rigid system layers. In addition to that, we introduce cross-layer cooperation allowing an efficient use of the available resources. Specific scenarios illustrate the feasibility of our approach.