• Journal of Korea Multimedia Society
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• v.15 no.12
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• pp.1499-1505
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• 2012

Recently, the distributed processing system for big data has been actively investigated owing to the development of high speed network and storage technologies. In addition, virtual system that can provide efficient use of system resources through the consolidation of servers has been increasingly recognized. But, when we configure distributed processing system for big data in virtual machine environments, many problems occur. In this paper, we did an experiment on the optimization of I/O bandwidth according to the creation and placement of VMs and tasks with composing Hadoop cluster in virtual environments and evaluated the results of an experiment. These results conducted by this paper will be used in the study on the development of Hadoop Scheduler supporting I/O bandwidth balancing in virtual environments.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1714-1717
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• 1997

A human operator is able to perform some tasks smoothly with force feedvack for the teleoperation or a virtual device in a the virtual environments. This paper describes a virtual force generation method with which operator can feel the interactive force between virtula robot and artificial environments. A virtual force generation algortihm is applied to generate the contact force at the arbitrary point of virtual robot, and the virtual force is displayed to the human operator via a tendon master arm consisted with 3 motors. Some experiments has beencarried out to verify the effectiveness of the force generation algorithm and usefulness of the developed backdrivable master arm.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2007.04a
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• pp.397-400
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• 2007

In this paper, we discuss the user-customized interaction for intelligent home environments. The interactive system is based upon the integrated techniques using both speech and face recognition. For essential modules, the speech recognition and synthesis were basically used for a virtual interaction between user and proposed system. In experiments, particularly, the real-time speech recognizer based on the HM-Net(Hidden Markov Network) was incorporated into the integrated system. Besides, the face identification was adopted to customize home environments for a specific user. In evaluation, the results showed that the proposed system was easy to use for intelligent home environments, even though the performance of the speech recognizer did not show a satisfactory results owing to the noisy environments.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.58-61
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• 2003

This paper proposes e-Learning environments far digital circuit experiment. The e-Learning environments are implemented as a WBT system that includes the circuits monitoring system and the students management system. In the WBT client-server system, the instructor represents the server and students represent clients. The client computers are equipped with a digital circuit training board and connected to the server on the World Wide Web. The training board consists of a Programmable Logic Device (PLD) and measuring instruments. The instructor can reconfigure the PLD with various circuit designs from the server so that students can investigate signals from the training board. The instructor can monitor the progress of the students using Joint Test Action Grouo(JTAG) technology. We implement the WBT system and a courseware fo digital circuits and evaluation the environments.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2006.06a
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• pp.329-333
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• 2006

New computing paradigm in ubiquitous computing environments is revolutionizing the way people interact with computers, services and the surrounding physical spaces. In order to provide stronger authentication, MIST proposed an authentication framework for ubiquitous computing environments and assigned confidence values to some authentication methods to facility the combining. However, the assigned confidence values lack sufficient evidence. In this paper reliable confidence values for each authentication method used in MIST is proposed. These confidence values can combine multiple confidence values in some manner, producing a more accurate net confidence value. Authentication entities with confidence values allows the authentication framework to blond nicely into ubiquitous computing environments.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.11
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• pp.79-90
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• 2003

In this paper, we propose a multisensor-based navigation algorithm for a mobile robot, which is intelligently searching the goal location in unknown dynamic environments using multi-ultrasonic sensor. Instead of using “sensor fusion” method which generates the trajectory of a robot based upon the environment model and sensory data, “command fusion” method by fuzzy inference is used to govern the robot motions. The major factors for robot navigation are represented as a cost function. Using the data of the robot states and the environment, the weight value of each factor using fuzzy inference is determined for an optimal trajectory in dynamic environments. For the evaluation of the proposed algorithm, we performed simulations in PC as well as experiments with IRL-2002. The results show that the proposed algorithm is apt to identify obstacles in unknown environments to guide the robot to the goal location safely.

• Environmental Engineering Research
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• v.20 no.3
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• pp.237-245
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• 2015

Particulate matter in indoor environments has caused public concerns in recent years. The objective of this research is to explore the influence of radiators on particle size distributions and concentrations. The particle size distributions as well as concentrations above radiators and in the adjacent indoor air are monitored in forty-two indoor environments in Xi'an, China. The temperatures, relative humidity and air velocities are also measured. The particle size distributions above radiators at ten locations are analyzed. The results show that the functional difference of indoor environments has little impact on the particle size distributions above radiators. Then the effects of the environmental parameters (particle concentrations in the adjacent indoor air, temperatures, relative humidities and air velocities) on particle concentrations above radiators are assessed by applying multiple linear regression analysis. Three multiple linear regression models are established to predict the concentrations of $PM_{10}$, $PM_{2.5}$ and $PM_1$ above radiators.

• Computers and Concrete
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• v.6 no.5
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• pp.421-435
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• 2009

Chloride induced corrosion is a concern that governs the durability of concrete structures in marine environments, especially in tidal environments. During the service lives of concrete structures, internal cracks in the concrete cover may appear due to imposed loads, accelerating chloride penetration because of the simultaneous action of environmental and service structural loads. This paper investigated the effects of cyclic flexural loads on chloride diffusion characteristics of plain concretes, and proposed a model to predict the chloride penetration into plain concretes subjected to both tidal environments and different cyclic flexural load levels. Further, a new experiment was performed to verify the model. Results of the model using Finite Difference Method (FDM) showed that the durability of concretes in tidal environments was reduced as cyclic flexural load levels, SR, increased, and the modeling results fitted well with the experimental results.

• International Journal of Contents
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• v.10 no.3
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• pp.64-72
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• 2014

This study explored the elements that affect team achievements in virtual environments. In this study, consideration was given to the role of group dynamics in facilitating productive interaction. We aspired to reveal the mechanisms of group dynamics and examined how group dynamics affected team achievements in virtual environments. The empirical study was performed with undergraduate students enrolled in an e-learning course. In collaboration with other majors, students executed team projects and managed project issues in forums or chat rooms. The results of the empirical study indicated that leadership, creative friction, and group cohesion (components of group dynamics) had positive relationships with team achievements. The findings confirmed that addressing creative conflict is a method to improve team performance and that leadership is a key factor in project teams.

• Journal of Korea Multimedia Society
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• v.17 no.3
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• pp.353-363
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• 2014

Cloud computing is an internet-based technology, providing services to the virtualized IT environment, and allowing users to add or remove resources of hardware or software at their discretion. Since Cloud computing can construct virtually integrated environments out of multiple local computing environments, various information services can be provided by it. In addition, state organizations also strive to build the cloud computing environments due to the benefits of reduced costs to introduce the system and of reduced time to build and provide the IT services. This study suggests a web-based cloud computing system for the computing environments, to be applied for the Korean National Health and Nutrition Examination Survey (KNHANES) by the Ministry of Health and Welfare, Republic of Korea.