• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.4
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• pp.209-215
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• 2006

Recently Permanent Magnet Linear Synchronous Motors(PMLSMs) are widely used for many linear transportation applications. The PMLSM has many advantages such as simple structure, high speed and thrust. However, especially in short primary type PMLSM, there exists very large detent force, which makes the thrust force ripple, undesired vibration and noise. The detent force is composed of the Cogging force and the End force. The Cogging force comes from the interaction between the permanent magnets and interior teeth of the stator. And the End force acts on the exterior teeth of the stator by the permanent magnets. Usually End force is larger than Cogging force, so the detent force is drasically reduced only by reducing the End force. This paper shows the End force is minimized by optimizing the stator length and chamfering the shape of the exterior teeth of the stator.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.780-781
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• 2008

This paper deals with optimum design criteria for maximum torque density & minimum torque ripple of Synchronous Reluctance Motor (SynRM) according to the rated wattage using response surface methodology (RSM). The RSM has been achieved to use the experimental design method in combination with Finite Element Method and well adapted to make analytical model for a complex problem considering a lot of interaction of design variables. The proposed procedure allows to define the rotor optimum shape for maximum torque density & minimum torque ripple starting from an existing motor or a preliminary design.

• Proceedings of the Korean Society for Cognitive Science Conference
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• 2010.05a
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• pp.55-59
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• 2010

To examine iterocular interactions in normal subjects, we recorded EEG activity from channel O1 and O2 on 14 healthy subjects while checkerboard pattern reversals were presented to each eye with different interstimulus intervals (ISIs) ranging from 0 to 218 ms. When pattern reversals were presented asynchronously to each eye, P-1 activity evoked by each reversal was significantly suppressed compared to the activation evoked by synchronous reversals. Furthermore, when there was time delay between pattern reversals to each eye, theta (4-10 Hz) band power was also significantly decreased, whereas beta (10-30 Hz) band power was relatively preserved. Our results suggest that neural activity evoked by sustained but not yet reversed checkerboard from one eye might inhibit upcoming neural response evoked by reversed checkerboard from the other eye. Decreased P-1 activity might reflect such inhibitory interaction between two eyes. Also, decreased theta and preserved beta band power might reflect engagement of different neural circuit for binocular / monocular vision.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.12
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• pp.623-627
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• 2006

This paper deals with the optimum rotor design solution on torque ripple reduction for a SynRM with concentrated winding using response surface methodology (RSM). The RSM has been achieved to use the experimental design method in combination with finite element method (FEM)and well adapted to make analytical model for a complex problem considering a lot of interaction of design variables. Comparisons are given with characteristics of a SynRM according to flux barrier number, flux barrier width variation, respectively.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2002.05a
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• pp.221-228
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• 2002

The NAVER is based on a cluster of low-cost personal computers. The goal of NAVER is to provide flexible, extensible, scalable and re-configurable framework for the diverse virtual environments especially for Gamsung research experiments. Personal computers are divided into three servers are according to their specific functions: Render Server, Device Server and Control Server. While Device Server contains external modules requiring event-based communication for the integration, Control Server contains external modules requiring synchronous communication every frame. And, the Render Server consists of 5 managers: Scenario Manager, Event Manger, Command Manager, Interaction Manager and Sync Manager. In this paper, we discuss NAVER as effective distributed system and its application to Gamsung experiment.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.669-670
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• 2006

This paper deals with the optimum rotor design solution on torque ripple reduction for a SynRM with concentrated winding using response surface methodology (RSM). The RSM has been achieved to use the experimental design method in combination with finite element method (FEM)and well adapted to make analytical model for a complex problem considering a lot of interaction of design variables. Comparisons are given with characteristics of a SynRM according to flux barrier number, flux barrier width variation, respectively.

• Journal of Music and Human Behavior
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• v.17 no.1
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• pp.97-125
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• 2020

This case study examined the effects of synchronization-based group music therapy for improving peer interaction of children with autism spectrum disorder (ASD). The participants were five children between the ages of 6 and 10 with ASD. A total of eight 30-minute music therapy sessions were conducted two times a week. During sessions, target behaviors (i.e., engagement in joint action, synchronized movements, eye contact, and initiation of social interaction) were observed and analyzed. Also, the PIPPS-P was completed by parents to identify behavioral changes in real-life environments from pretest to posttest. Following the intervention, all of the participants showed increases in synchronized movements with peers and attempts to initiate social interaction. In addition, parents rated their children's play behavior as being improved in their everyday living environment. These results support that synchronous movements between children with ASD, which were facilitated with rhythmic cueing, led to enhanced engagement in joint action. Considering that those movements are the basis for further social skills (e.g., play behavior), this study also indicates that synchronization-based group music therapy could be an effective therapeutic approach for improving the peer interaction of this population.

• Journal of Digital Convergence
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• v.16 no.10
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• pp.1-9
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• 2018

The purpose of this study is to examine the concepts and types of cross-cultural collaborative online learning that enhance the utilization of advanced ICT in education and contribute to the promotion of educational exchanges between countries, and suggest exchange learning design models necessary for the active introduction. For this study, previous studies related to cross-cultural collaborative online learning were examined. As a result, cross-cultural collaborative online learning is an educational method based on constructivism that explore and construct knowledge by interacting and collaborating with students, teachers, and field experts who are linguistically and culturally heterogeneous based on advanced ICT. The type of cross-cultural collaborative online learning could be divided into synchronous exchange learning centered on remote video classes and asynchronous exchange learning centered on website based tasks. A PPIE learning design model considering the characteristics of each type is presented.

• Journal of the Korean Magnetics Society
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• v.26 no.1
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• pp.31-37
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• 2016

This study considered the reduction of the detent force of a permanent magnet linear synchronous generator (PMLSG). The PMLSG has a relatively large magnetic air gap. Thus, a slotted type of stator structure is generally employed. Furthermore, the detent force, which is caused by energy imbalances owing to the interaction between tooth-slot structures and the permanent magnets (PMs), must be minimized for start-up operation. Therefore, in this paper, the methods of auxiliary teeth and a notch in the teeth are applied to reduce the detent force.

• Journal of The Korean Association of Information Education
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• v.26 no.3
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• pp.175-186
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• 2022

This study has explored the facilitating factors affecting the learning persistence of university students and divided Emergency Remote Teaching(ERT) into two types based on its policies. The conclusions are as follows: First, perceived usefulness was the facilitating factor affecting learning persistence in Synchronous ERT. Therefore, learning persistence would improve by establishing various strategies such as exploring appropriate teaching strategies and building a stable infrastructure. Second, it was perceived usefulness, social presence, and system quality that were the facilitating factors affecting learning persistence in Asynchronous ERT. Thus, learning persistence would increase accompanied by immediate feedback, more active interaction, and so on.