• Convergence Security Journal
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• v.13 no.3
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• pp.17-23
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• 2013

Clustering is required to configure clustering interdependent structural technology. Clustering handles variable workloads or impede continuity of service to continue operating in the event of a failure. Long as high-availability clustering feature focuses on server operating systems. Active-standby state of two systems when the active server fails, all services are running on the standby server, it takes the service. This function switching or switchover is called failover. Long as high-availability clustering feature focuses on server operating systems. The cluster node that is running on multiple systems and services have to duplicate each other so you can keep track of. In the event of a node failure within a few seconds the second node, the node shall perform the duties broken. Structure for high-availability clustering efficiency should be measured. System performance of infrastructure systems performance, latency, response time, CPU load factor(CPU utilization), CPU processes on the system (system process) channels are represented.

• The KIPS Transactions:PartC
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• v.11C no.7 s.96
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• pp.923-930
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• 2004

Wireless sensor networks is a core technology of ubiquitous computing which enables the network to aware the different kind of context by integrating exiting wired/wireless infranet with various sensor devices and connecting collected environmental data with applications. However it needs an energy-efficient approach in network layer to maintain the dynamic ad hoc network and to maximize the network lifetime by using energy constrained node. Cluster-based data aggregation and routing are energy-efficient solution judging from architecture of sensor networks and characteristics of data. In this paper. we propose a new distributed clustering algorithm in using distance from the sink. This algorithm shows that it can balance energy dissipation among nodes while minimizing the overhead. We verify that our clustering is more en-ergy-efficient and thus prolongs the network lifetime in comparing our proposed clustering to existing probabilistic clustering for sensor network via simulation.

• Journal of KIISE:Computing Practices and Letters
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• v.13 no.1
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• pp.1-10
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• 2007

An advantage of the mobile ad hoc network (MANET) is that mobile nodes can self-organize the network topology without the help of network infrastructure. However, for the perfect self-organization of the MANET, each mobile node needs to self-configure its address. Even though a mobile node configures a unique address during the booting time, its address may conflict with nodes in other MANETs since MANETs containing the same address can be merged. The address autoconfiguration protocol implemented in this work consists of the strong DAD (Duplicate Address Detection) and the weak DAD. A unique address of a node is assigned by the strong DAD during the booting time and the weak DAD is used to detect address conflict and resolve address conflict during the ad hoc routing. In this work, we have implemented address autoconfiguration in the IPv6-based MANET using AODV as the routing protocol. We describe how the IPv6 address autoconfiguration is implemented and verify our implementation by showing the test scenarios on our testbed.

• Journal of Internet Computing and Services
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• v.17 no.2
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• pp.1-9
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• 2016

Users are provided infrastructure such as CPU, memory, network, and storage as IaaS (Infrastructure as a Service) service on cloud computing environments. However storage instances cannot support the maximum storage capacity that SQL servers can use, because the capacity of instances provided by service providers is usually limited. In this paper, we propose a method of securing mass storage capacity for SQL servers by sharing network disks with limited storage capacity. We confirmed through experiments that it is possible to secure mass storage capacity, which exceeds the maximum storage capacity provided by an instance with Amazon EBS on Amazon EC2 Windows environments, and it is possible to improve the overall performance of the SQL servers by increasing the disk capacity and performance.

• Convergence Security Journal
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• v.7 no.2
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• pp.101-106
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• 2007

Recently, Ubiquitous innovation is being promoted so that they can support the uHealthcare provide management to human's health. It is thus necessary to conduct such research on the medical care environment where there is a high demand for utilization of status information. In the current situation, there is a lack of research on measures of security processing and monitoring patient status information produced from rapid growth of infra within Medical environment. This study suggests a solution of using RFID to gather patient information such as inpatient information, location of treatment room, progress of patient, humidity, temperature, and diagnostic status, after which the information are protect and processed using security level method.

• KIISE Transactions on Computing Practices
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• v.21 no.3
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• pp.239-246
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• 2015

QR(Quick Response) Code has been developed to provide greater storage capacity and more functionality compared to 1D bar codes. With the emergence of increasingly mobile devices equipped with cameras such as smart-phones and tablets, QR codes have become very popular and more important in mobile businesses. Typically, most QR codes are used as a URL link for redirecting users to webpages. However, the URL based QR codes are required to be connected over the internet and to be run a server. This can incur unnecessary traffics in the Internet. Furthermore, it is not suitable for the country lagging behind others in its network infrastructure. In this paper, we propose a server-less ${\mu}$-webpage to provide mobile web services and be optimized for the capabilities and limitations of QR Code. We have implemented the ${\mu}$-webpage in Android, and the results showed that the proposed mechanism can provide web-services without requiring extra servers or incurring mobile traffic data compared to the URL-based QR Codes.

• The Journal of the Korea Contents Association
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• v.8 no.9
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• pp.19-26
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• 2008

With the development of ubiquitous computing and the construction of infrastructure for one-to-one personalized services, the importance of context-aware services based on user's situation and environment is being spotlighted. The smart home technology connects real space and virtual space, and converts situations in reality into information in a virtual space, and provides user-oriented intelligent services using this information. In this paper, we proposed the discovery of the behavior sequence pattern using the mining in the smart home. We discovered the behavior sequence pattern by using mining to add time variation to the association rule between locations that occur in location transactions. We can predict the path or behavior of user according to the recognized time sequence and provide services accordingly. To evaluate the performance of behavior consequence pattern using mining, we conducted sample t-tests so as to verify usefulness. This evaluation found that the difference of satisfaction by service was statistically meaningful, and showed high satisfaction.

• Spatial Information Research
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• v.16 no.1
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• pp.51-64
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• 2008

Recently, development and research of u-City established the ubiquitous environment which can be anytime, anywhere computing or network, has been much highlighted. Thus, current urban facilities should be managed by ubiquitous concept, and monitored location and status information in a real-time manner, and controled if necessary. In order to be establish in the purpose of management, indirect mapping through id-tag is better than facility management directly. For instance, RFID, UCODE, UFID. In this paper, we propose that represent facility object through UOID(Unique Object IDentification). UOID comprises three parts; 1) sensing object, 2) facility object, 3) cell object consists of facilities. and Life cycle management system in UOID, and network system connected with internet is proposed. We wish that proposed UOID and network system mange u-City facilities effectively, and also provide ubiquitous service to the citizen, one of the integrate service of u-City platform.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.3
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• pp.215-221
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• 2007

In Ubiquitous computing, RFID has been become a key technology to provide the real-time location information of users. For this purpose, many recent researches have been conducted regarding RTLS based on the RFID system. In this study, we evaluated the efficiency and feasibility of the velocity gauging system using RTLS based on the RFID system. By using this system, the velocity of mobile units were measured and the accuracy was evaluated with data obtained from DGPS. The results demonstrated that RTLS based on the RFID system would be suitable to measure with relatively low velocity information of mobile units. When RFID infrastructures are being constructed, the developed system will be a better position to increase popularity of velocity information service.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.799-801
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• 2011

Computational science is a field of study concerned with constructing mathematical models and quantitative analysis techniques and using large computing resources to solve the problems which are difficult to approach in a physical experimentally. Recently, a new web-based simulation environment for computational science is becoming more and more popular for supporting multi-user access without restriction of space or time, however, to develop web-based simulation applications, the researchers performed their works too much difficulty. In this paper, we present automated web interface generation tool that allows applied researchers to concentrate on advanced research in their scientific disciplines such as Chemistry, Physics, Structural Dynamics.