Yong-June Shin

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Real time network monitoring for intrusions is offered by various host and network based intrusion detection systems. These systems largely use signature or pattern matching techniques at the core and thus are ineffective in detecting unknown anomalous activities. In this paper, we apply signal processing techniques in intrusion detection systems, and(More)
Per-flow congestion control helps endpoints fairly and efficiently share network resources. Better utilization of network resources can be achieved, however, if congestion management algorithms can determine when two different flows share a congested link. Such knowledge can be used to implement cooperative congestion control or improve the overlay topology(More)
In this paper, we introduce a new high-resolution reflectometry technique that operates simultaneously in both the time and frequency domains. The approach rests upon timefrequency signal analysis and utilizes a chirp signal multiplied by a Gaussian time envelope. The Gaussian envelope provides time localization, while the chirp allows one to excite the(More)
For reasonable power quality assessment of transient disturbances in electric power systems, new transient power quality indices are developed based on a signal processing technique, time-frequency analysis. Based on the time-frequency distribution of a transient disturbance, a set of time-frequency based power quality indices are developed. In this paper,(More)
The present paper addresses systematic approach to Condition-Based Maintenance, and research results at the University of South Carolina Condition-Based Maintenance Research Center, directly related to U.S. Army rotorcraft Vibration Management Enhancement Program. The paper gives an analysis of the CBM concept and its functional layers, such as condition(More)
Defective cables in the electric power systems of nuclear power plants can cause a component to fail, resulting in potential safety concerns. Due to this problem, a non-destructive, non-intrusive condition assessment technique is highly desirable. Joint time-frequency domain reflectometry (JTFDR) is proposed and verified to be effective for cross-linked(More)
The classical time-frequency distributions represent timeand frequency-localized energy. However, it is not an easy task to analyze multiple signals that have been simultaneously collected. In this paper, a new concept of non-parametric detection and classification of the signals is proposed using the mutual information measures in the time-frequency(More)
Internet paths sharing the same bottleneck can be identified using several shared congestion detection techniques. However, all of these techniques have been designed to detect shared congestion between a pair of paths. To cluster N paths by shared congestion, a straightforward approach of using pairwise tests would require O(N) time complexity. In this(More)
A new concept of nonparametric signal detection and classification technique is proposed using mutual information measures in the time–frequency domain. The time– frequency-based self-information and mutual information are defined in terms of the cross time–frequency distribution. Based on time–frequency mutual information theory, this paper presents(More)