• The Journal of Korean Institute of Communications and Information Sciences
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• v.12 no.5
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• pp.439-450
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• 1987

Data, distributed and/or duplicated among multiple computers interconnected by a LAN, need to be managed consistently and accessed transparently by users. A command/file server, named UTP, which meets the preceding needs was developed for supermini-computers which are interconnected by an Ethernet-based LAN and run under UNIX OS.

• The Journal of the Korea Contents Association
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• v.5 no.2
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• pp.79-85
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• 2005

In order to handle client's requests while multiple servers seamlessly work in the web server cluster environment, it is vital to implement a router that execute a routing using TCP information and requested target content. The implemented package software measured packet volume that was generated from data generator, virtual server, and server 1, 2, 3, and could find out traffic distribution toward Server 1, 2, 3. As the result of the study shows, Round Robin Algorithm ensured definite traffic distribution, unless incoming data loads differ much. Although error levels were high in some partial cases, they were eventually alleviated by repeated tests for a longer time.

• KIISE Transactions on Computing Practices
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• v.22 no.1
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• pp.26-31
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• 2016

Migrim(Migration enhanced Grid Middleware) is a communication middleware between embedded devices and multiple servers. In traditional client-server communication, users' requests are sent to and processed by a designated server even though the server may suffer from a heavy load. In addition, the designated server may not have proper information to process the user's request correctly. Proposed connection migration mechanism and transaction migration mechanism are designed to improve the performance and accuracy of request processing. The connection migration is a procedure for delegating a connection to another server, which results in a well-distributed balancing of load among the servers. The transaction migration is a procedure for delegating a transaction to another server, and improves the accuracy of response.

• Journal of the Korea Society of Computer and Information
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• v.19 no.2
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• pp.11-19
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• 2014

In this paper, we build server consolidate virtualization focusing on NT server dilapidated and through analysis of the effect of this, has been presented the following results. First, it was possible to obtain an increase in the constant temperature constant humidity chamber efficiency by securing the upper surface space for computing data center mounted virtualization integration server servers multiple physical. Second, by the deployment of virtualization of a large server dilapidated, the introduction of new resources and the cost of maintaining computerized data center and reduce power consumption, the reduction of hardware introduction of additional due to the new server deployment it was possible to derive a cost reduction effect. We obtain the reduction of 89% and 79% compared with conventional consumption of cooling and power savings of the top surface, respectively. Integration of NT servers are virtualized can be expected to change in the Green-IT to contribute to providing the maintenance costs of computing centers in the future as well as current. Building a virtualization server integration applied in this paper can be similarly applied to the UNIX system and to integrate the server group other.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.3
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• pp.921-940
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• 2015

In this paper, we investigate the multi-resource allocation problem, a unique feature of which is that the multiple resources can compensate each other while achieving the desired system performance. In particular, power and time allocations are jointly optimized with the target of energy efficiency under the resource-limited constraints. Different from previous studies on the power-time tradeoff, we consider a multi-server case where the concurrent serving users are quantitatively restricted. Therefore user selection is investigated accompanying the resource allocation, making the power-time tradeoff occur not only between the users in the same server but also in different servers. The complex multivariate optimization problem can be modeled as a variant of 2-Dimension Bin Packing Problem (V2D-BPP), which is a joint non-linear and integer programming problem. Though we use state decomposition model to transform it into a convex optimization problem, the variables are still coupled. Therefore, we propose an Iterative Dual Optimization (IDO) algorithm to obtain its optimal solution. Simulations show that the joint multi-resource allocation algorithm outperforms two existing non-joint algorithms from the perspective of energy efficiency.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.4B
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• pp.424-434
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• 2004

Ubiquitous network consists of various devices using several heterogeneous protocols and requires seamless communication between devices. This paper proposes a new hierarchical event service and multiple event server architecture to implement the service under ubiquitous environment. The proposed event service classifies devices by logical and physical location to abstract the idiosyncrasy of used protocols, and reduces network load. Due to the design consideration, the proposed architecture removes transfer of duplicated event data effectively. As a result, we can guarantee the reliable event delivery. The prototype multiple event server architecture was implemented according to the proposed idea and evaluated its performance under a home network test bed.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.44 no.1
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• pp.1-9
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• 2007

In this paper, we propose a new 3D modeling and rendering system using multiple stereo cameras. When target objects are captured by cameras, each capturing PC segments the objects and estimates disparity fields, then they transmit the segmented masks, disparity fields, and color textures of objects to a 3D modeling server. The modeling server generates 3D models of the objects from the gathered masks and disparity fields. Finally, the server generates a video at the designated point of view with the 3D model and texture information from cameras.

• The KIPS Transactions:PartA
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• v.11A no.6
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• pp.451-458
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• 2004

The previous studies focussed on the security problem and the fast re-authentication mechanism during handoffs in a single wireless LAN system. When the multiple wireless LAN systems share their network infrastructure one another, we propose an authentication mechanism allowing the subscriber to Perform the authentication procedure with the authentication server of its own wireless LAN system even in areas of other wireless LAN systems as well as in areas of its own wireless LAN system. In the proposed mechanism, the access point or the authentication server of other wireless LAN systems plays a role of the authentication agent between the subscriber and the authentication server of the subscriber's wireless LAN system. The proposed authentication mechanism is designed on the basis of the 802.1X and EAP-MD5 protocols.

• Journal of applied mathematics & informatics
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• v.26 no.1_2
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• pp.389-393
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• 2008

This paper describes a single-server queue where the server is unavailable during some intervals of time, which is referred to as vacations. The major contribution of this work is to derive general formulas for the additional delay in the vacation models of the single vacations, head of line priority queues with non-preemptive service, and multiple vacations and idle time.

• Proceedings of the Korean Statistical Society Conference
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• 2003.10a
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• pp.1-8
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• 2003

The traffic patterns of today's IP networks exhibit two important properties: self-similarity and long-range dependence. The fractional Brownian motion is widely used for representing the traffic model with the properties. We consider a single server fluid queueing system with input process of a fractional Brownian motion type. Formulas for effective bandwidth are derived in a single source and multiple source cases.