• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.588-590
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• 2006

Recently, many on-line approaches to instrument channel surveillance (drift monitoring and fault detection) have been reported worldwide. On-line monitoring (OLM) method evaluates instrument channel performance by assessing its consistency with other plant indications through parametric or non-parametric models. The heart of an OLM system is the model giving an estimate of the true process parameter value against individual measurements. This model gives process parameter estimate calculated as a function of other plant measurements which can be used to identify small sensor drifts that would require the sensor to be manually calibrated or replaced. This paper describes an improvement of auto-associative kernel regression by introducing a correlation coefficient weighting on kernel distances. The prediction performance of the developed method is compared with conventional auto-associative kernel regression.

• Journal of information and communication convergence engineering
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• v.16 no.1
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• pp.38-42
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• 2018

In this paper, we consider measurement allocation problem in a spatially correlated sensor field. Our goal is to determine the probability of each sensor's being measured based on its contribution to the estimation reliability; it is desirable that a sensor improving the estimation reliability is measured more frequently. We consider a spatial correlation model of a sensor field reflecting transmission power limit, noise in measurement and transmission channel, and channel attenuation. Then the estimation reliability is defined distortion error between event source and its estimation at sink. Motivated by the correlation nature, we model the measurement allocation problem into a cooperative game, and then quantify each sensor's contribution using Shapley value. Against the intractability in the computation of exact Shapley value, we deploy a randomized method that enables to compute the approximate Shapley value within a reasonable time. Besides, we envisage a measurement scheduling achieving the balance between network lifetime and estimation reliability.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2815-2817
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• 2001

This study describes the emotion classification using two different feature extraction methods for four-channel EEG signals. One of the methods is linear prediction analysis based on AR model. Another method is cross-correlation coefficients on frequencies of ${\theta}$, ${\alpha}$, ${\beta}$ bands. Using the linear predictor coefficients and the cross-correlation coefficients of frequencies, the emotion classification test for four emotions, such as anger, sad, joy, and relaxation is performed with a neural network. Comparing the results of two methods, it seems that the linear predictor coefficients produce the better results than the cross-correlation coefficients of frequencies for-emotion classification.

• Korean Journal of Remote Sensing
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• v.17 no.4
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• pp.335-344
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• 2001

Texture is extensively studied in a variety of image processing applications such as image segmentation and classification because it is an important property to perceive regions and surfaces. This paper focused on the analysis and synthesis of textured single and multiband images using Markov Random Field model considering the existent spatial correlation. Especially, for multiband images, the cross-channel correlation existing between bands as well as the spatial correlation within band should be considered in the model. Although a local interaction is assumed between the specified neighboring pixels in MRF models, during the maximization process, short-term correlations among neighboring pixels develop into long-term correlations. This result in exhibiting phase transition. In this research, the role of temperature to obtain the most probable state during the sampling procedure in discrete Markov Random Fields and the stopping rule were also studied.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.9C
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• pp.887-895
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• 2009

This paper proposes a cooperative power allocation with the use of partial channel information (e.g., the average signal-to-noise ratio (SNR) and transmit correlation) in multi-cell dual-hop multi-input single-output (MISO) relay systems. In a dual-hop MISO relay channel, it is desirable to allocate the transmit power between dual-hop links to maximize the end-to-end capacity. We consider the maximization of the end-to-end capacity of a dual-hop MISO relay channel under sum-power constraint. The proposed scheme adaptively allocates the transmit power considering the average channel gain of the target relay and the transmit correlation of the desired and inter-relay interference channel from adjacent relays. It is shown by means of upper-bound analysis that the end-to-end capacity can be maximized by making the angle difference of the principal eigenvectors of the desired and inter-relay interference channel orthogonal in highly-correlated channel environments. Finally, the performance of the proposed scheme is verified by computer simulation.

• The Journal of the Acoustical Society of Korea
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• v.32 no.1
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• pp.79-85
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• 2013

Feature extraction of CASA system uses time continuity and channel similarity and makes correlogram of auditory elements for the use. In case of using feature extraction with cross correlation coefficient for channel similarity, it has much computational complexity in order to display correlation quantitatively. Therefore, this paper suggests feature extraction method using non-parametric correlation coefficient in order to reduce computational complexity when extracting the feature and tests to segregate target speech by CASA system. As a result of measuring SNR (Signal to Noise Ratio) for the performance evaluation of target speech segregation, the proposed method shows a slight improvement of 0.14 dB on average over the conventional method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.8A
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• pp.733-738
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• 2002

Zero Cross-correlation Zone (ZCZ) code has a good performance in Multi-user CDMA system to get low correlation zone and reject co-channel interference. In this paper, we do analysis of spreading code design to obtain this kind of property of correlations with a complex spreading scheme and denote their effective performance for mobile communication system. In addition, a Jacket polyphase sequence is an example to show the improved performance and regular properties effective performance for mobile communication system. In addition, a Jacket polyphase sequence is as an example to show the improved performance and regular properties.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.291-292
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• 2008

In orthogonal frequency division multiplexing based wireless system, a pilot signal is often employed to estimate channel state information (CSI). However, the received pilot signal is interfered by other cell interference in multi-cell environments. We consider the estimation of CSI by utilizing orthogonal preambles and channel correlation.

• Proceedings of the IEEK Conference
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• 2001.06a
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• pp.117-120
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• 2001

In this paper, we propose a robust trellis coded modulation for a correlated Rayleigh fading channel. This method use only one transmit antenna, which can achieve superior performance compared to Space-Time Trellis Coded Modulation (STTC) over a wide channel correlation range among transmit antennas. The code is designed to have the largest Euclidean distance between faded signals at the receiver. Computer simulations are performed to evaluate the frame error rate (FER) performance and to compare the proposed code with the conventional one.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.8
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• pp.608-614
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• 2018

This paper describes the synthesis method for an adaptive SLB channel, which is robust to interference in the ULA radar system. The SLB channel based on the spatial DLC can be synthesized simply and is effective in blanking the signal coming from the sidelobe. We combined it with adaptive beamforming, which removes the strong interference using its correlation matrix. The adaptive SLB channel would suppress the interference below the noise, so it has good performance in an interference environment. This research will be applicable to planar array systems.