• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2001.06a
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• pp.25-28
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• 2001

A new decision-feedback equalization technique for a filter bank-based orthogonal frequency division multiplexing (OFDM) data transmission system operating in a frequency selective multipath fading channel is presented in this paper. At the cost of relatively increased computational complexity in comparison to the conventional OFDM systems, the proposed system achieves a better performance in terms of bit error rates. The simulation results confirm the superiority and robustness of our method, particularly, in the low SNR channel environment.

• Proceedings of the ESK Conference
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• 1997.10a
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• pp.359-365
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• 1997

When grasping a movable object or making an object move, humans feel kinesthetic sense. Kinesthetic sense is the human sense that the human feels in response to the motion acted on the human. The objecive of the paper is tranforming the kinesthetic sense to quantitized data that is useful from the viewpoint of engineering. To provide various motion patterns, 2-dimensional motion generator was built using 2-axis linear motors. Active stiffness and active damping were implemented by means of current control and force feedback techniques. Based on Taguchi method, the most dominant factors to affect kinesthetic sense were investigated. Also, some functions adequate to quantize the kinesthetic sense were found.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.143-144
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• 2006

This paper presents an adaptive OFDM system with multistep predictor to effectively compensate multiple feedback delays. The proposed scheme adaptively changes the modulation order per subcarrier based on the predicted CSI to improve data capacity and system performance.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.29B no.1
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• pp.26-33
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• 1992

This paper presents lattice structure of bilinear filter and the conversion equations from lattice parameters to direct-form parameters. Billnear models are attractive for adaptive filtering applications because they can approximate a large class of nonlinear systems adequately, and usually with considerable parsimony in the number of coefficients required. The lattice filter formulation transforms the nonlinear filtering problem into an equivalent multichannel linear filtering problem and then uses multichannel lattice filtering algorithms to solve the nonlinear filtering problem. The lattice filters perform a Gram-Schmidt orthogonalization of the input data and have very good easily extended to more general nonlinear output feedback structures.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1993.06a
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• pp.1078-1081
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• 1993

The Objective of this paper is to provide fuzzy control designers with a design tool for stable fuzzy logic controllers. Given multiple sets of data disturbed by vagueness uncertainty, we generate the implicative rules that guarantee stability and robustness of closed-loop fuzzy dynamic systems. We propose the cell-state transition method which utilizes Hsu's cell-to-cell mapping concept [1]. As a result, a generic and implementable design methodology for obtaining a fuzzy feedback gain K, a fuzzy hypercube [2], is provided and illustrated with simple examples.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2003.06a
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• pp.238-241
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• 2003

This paper presents a nonlinear least squares decision feedback equalizer Bilinear systems are attractive because of the ability to approximate a large class of nonlinear systems efficiently. The nonlinearity of channel is modeled using a bilinear system. The algorithms are derived by using the QR decomposition for minimization covariance matrix of prediction error by applying Givens rotation to the bilinear model. Result of computer simulation experiments that compare the performance of the bilinear DFE to two other DFE's in eliminating the intersymbol interference caused by a nonlinear channel are presented In the paper.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2193-2195
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• 2001

This paper proposes test strategy detecting the faulted digital device or the faulted digital circuit on the digital circuit board using signature analysis technique based on the polynoimal division theory. SSA(serial Signature Analysis) identifies the faults by comparing the reminder from good device and reminder from the tested device, which reminder is obtained by enforcing the data stream outputed from output pins of tested device on LFSR(Linear Feedback Shift Resister) representing the characteristic equation.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.11a
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• pp.966-969
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• 2007

In this paper, we propose a novel probing mechanism for adaptive transmission of video data based on congestion control and client state. The proposed mechanism is friendly to the network dominant transport protocols (TCP) and can reduce fluctuations compared to the previous works.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.6_2
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• pp.585-592
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• 2013

CBIR is an effective tool to search and extract image contents in a large remote sensing image database queried by an operator or end user. However, as imaging principles are different by sensors, their visual representation thus varies among image modality type. Considering images of various modalities archived in the database, image modality difference has to be tackled for the successful CBIR implementation. However, this topic has been seldom dealt with and thus still poses a practical challenge. This study suggests a cross modality CBIR (termed as the CM-CBIR) method that transforms given query feature vector by a supervised procedure in order to link between modalities. This procedure leverages the skill of analyst in training steps after which the transformed query vector is created for the use of searching in target images with different modalities. Current initial results show the potential of the proposed CM-CBIR method by delivering the image content of interest from different modality images. Despite its retrieval capability is outperformed by that of same modality CBIR (abbreviated as the SM-CBIR), the lack of retrieval performance can be compensated by employing the user's relevancy feedback, a conventional technique for retrieval enhancement.

• English Language & Literature Teaching
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• v.17 no.3
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• pp.119-139
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• 2011

Free-talking in Korea has recently been emphasized as a way of improving students' speaking ability outside of the classroom. The purpose of this study is to examine perceptions of free-talking, to understand what type of roles were played by or allotted between Korean students and international professors (IPs) and to look for effective speaking strategies for utilizing free-talking. Participants of this study were 68 university students and 23 IPs. The data collected through a survey type of questionnaire were analyzed by this researcher and the main findings indicate that students and IPs have somewhat different viewpoints about their concepts of free-talking. Students expressed varying viewpoints depending on their experience and class (year). In terms of the benefits, usefulness, and satisfaction of free-talking, students and IPs seem to be in more agreement with each other although the two groups have conflicting perceptions in the particular operation of free-talking, especially in terms of preparation and feedback. Students stated that they feel anxious, nervous, and that they struggle with peer pressure while free-talking. However, they feel that through free-talking they build up confidence and increase their speaking ability. Regarding roles, most professors play a helpful role as a guide or facilitator while students want professors to provide more suitable materials and to tutor them by means of appropriate feedback and strategies as well-prepared teachers like a prompter, participant or tutor in the timely manner. Finally, this paper proffers a few practical suggestions for activating free-talking and a discussion of the pedagogical implications.