• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.401-404
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• 1996

A new method for the electrostatic suspension of disk-shaped objects is proposed which is based on a switched-voltage control scheme. It operates according to a relay feedback control and deploys only a single high-voltage power supply capable of delivering a dc voltage of positive and/or negative polarity. In addition to the unique feature that no high-voltage amplifiers are needed, this method provides a remarkable system simplification relative to conventional methods. It is shown that despite the inherent limit cycle property of relay feedback based control, an excellent performance in vibration suppression is attained due to the presence of a relatively large squeeze film damping. In this paper, the functional principle of the switched voltage control scheme, numerical analysis, stator electrode design, and a nonlinear dynamic model of the suspension system are described. Experimental results will be presented for a 4-inch silicon wafer that clearly reveal the capability of the proposed control structure to suspend the wafer stably at an airgap length of 50 .mu.m.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2008.04a
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• pp.184-189
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• 2008

In this study, an artificial wheel load generation method is proposed to assist practical engineers performing dynamic analysis with simple procedure. To generate an artificial wheel loads from running vehicle, PSD(Power Spectrum Density) profiles of actual wheel load were sampled in terms of various road roughnesses. A detailed truck and bridge models were used for sampling actual wheel load to represent the real motion of moving vehicle. These wheel load profiles were simplified for the artificial wheel load. The simplification of actual wheel load profiles was performed by regression analysis. The result showed that the artificial wheel load well represents the real profiles of wheel load.

• Proceedings of the IEEK Conference
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• 2001.06d
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• pp.37-40
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• 2001

The most important issues in gesture recognition are the simplification of algorithm and the reduction of processing time. The mathematical morphology based on geometrical set theory is best used to perform the real-time processing. A key idea of the algorithm proposed in this paper is to apply morphological shape decomposition. The primitive elements extracted from a hand gesture have very important information including the directivity of the hand gestures. Based on this algorithm, we proposed the morphological hand-gesture recognition algorithm using feature vectors extracted from lines connecting the center points of a main-primitive element and sub-primitive elements. Through the experiments, we applied to the video contents browsing system with natural interactions and demonstrated the efficiency of this algorithm.

• Proceedings of the IEEK Conference
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• 2001.06c
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• pp.59-62
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• 2001

This paper discusses a data mining technique for time series analysis of traffic data, which provides useful knowledge for network configuration management. Commonly, a network designer must employ a combination of heuristic algorithms and analysis in an interactive manner until satisfactory solutions are obtained. The problem of heuristic algorithms is that it is difficult to deal with large networks and simplification or assumptions have to be made to make them solvable. Various data mining techniques are studied to gain valuable knowledge in large and complex telecommunication networks. In this paper, we propose a traffic pattern association technique among network nodes, which produces association rules of traffic fluctuation patterns among network nodes. Discovered rules can be utilized for improving network topologies and dynamic routing performance.

• Journal of the Korean Institute of Telematics and Electronics
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• v.21 no.3
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• pp.1-5
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• 1984

It is investigated that Mahalanobis distances are invariant under a proper transformation and interest MDs are distributed as non-central chi-square while it is well known that intraset MDs are distributed as central chi-square. And their moments have been expressed as simple polynomials whose coefficients satisfy straightforward recursive relations.

• Journal of the Korea Society of Computer and Information
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• v.22 no.4
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• pp.107-113
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• 2017

The results showed that the male teachers' have higher expectations of the free learning semester compared to the female teachers'. Furthermore, the teachers who had experienced the free learning semester felt less job burdens than the teachers who did not. In addition, the subject teachers showed higher expectations of the free learning semester than the general teachers or the homeroom teachers. Therefore, in order to establish a stable system of free learning semester, it should be preceded by development of differentiated program of special education, free learning semester, strengthening of advance training, establishment of the system for participating in the whole school and the simplification of administration.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1996.06a
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• pp.195-198
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• 1996

In this paper, we introduce the notion of the smoothly perfect 8-connected (SP8C) contour and propose a coding technique for the SP8C contours. Based on the contour simplification using the majority filter proposed by Gu[6], SP8C contours are extracted on the contour lattice from the segmented image. By noting that, unlike the perfect 8-connected contours, the SP8C contours are restricted to travel in only 3 different directions along the contours, we also propose two techniques for encoding the SP8C contours. The one is the modified version of the neighbouring direction segment coding by Kandeko[2], while the other is to employ the notion of the entropy coding. From the comparison in terms of the entropy, it is shown that the proposed SP8C contours require les bits in encoding the diagonal contours than the 4-connected contours employed by Gu. And computer simulations reveal that the contours can be efficiently encoded by the proposed technique.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2019.11a
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• pp.22-23
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• 2019

The emerging Versatile Video Coding (VVC) standard introduces Bi-prediction with CU-level Weights (BCW) to enhance the bi-predictive prediction. The syntax element of BCW index is adaptively coded according to the value of NoBackwardPredFlag which indicates if there is no future picture in the display order among the reference pictures, and it can violate the flexibility of codec and cause the dependency issue. This paper proposes BCW clean-up design that allows all weights can be parsed without any condition. The experimental results show negligible BD-rate losses while resolving the issues.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.12
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• pp.1514-1519
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• 1999

This paper presents two flexible alternatives to the decoupled load flow(DCL) method. The proposed load flow methods can improve the convergence profiles of the DCL by reflecting in part the effects of the off-diagonal terms in the Jacobian at minimal costs. They can improve the convergence characteristics especially when the power system operating states deviate from the conditions required for stable convergence of the DCL and the P-Q coupling becomes significant. Two algorithms are obtained from the expression of the full Newton-Raphson load flow (NRL) method by successively diminishing the effects of the off-diagonal submatrices in the Jacobian. In the process of simplification, the Neuman series expansion is utilized. Test results show promising performances of the proposed algorithms in their convergence characteristics both in number of iterations and overall convergence speeds. Proposed algorithms are expected to provide flexible alternatives to the NRL when the DCL experiences convergence problems.

• Journal of the Korean Home Economics Association
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• v.41 no.10 s.188
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• pp.85-100
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• 2003

The purpose of this study is to analyze the aesthetic characteristics of grotesque images in fashion specially focused on the postmodern grotesque with the relationship between body and fashion. The results are as follows: The postmodern grotesque fashion images in the years of 1990-2000 can be analyzed as trans-stylistic, trans-boundaries which have been set by the modem western white elite men group. The postmodern grotesque fashion images in the years of 1990-2000 can be categorized as 1) unclear boundaries between genders: body and dress; human being and non-human being; life and death; wholeness and fragmentation; clear body and abject body. 2) violence to the body: body mutation by simplification, exaggeration; body injury.