Woohyun Choi

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In this paper, a method for abnormal acoustic event recognition in an audio surveillance system is presented. We propose a recognition scheme based on a hierarchical structure using a feature combination of Mel-Frequency Cepstral Coefficient (MFCC), timbre, and spectral statistics. A selective background adaptation is proposed for robust abnormal acoustic(More)
This paper proposes a novel filter bank composed of dominant Spectral Basis Vectors (SBVs) in a spectrogram. Spectral envelopes represented by the SBVs have shown to be excellent characteristic features for discriminating different acoustic events in noisy environment. Non-negative Matrix Factorization (NMF) and non-negative K-SVD (NKSVD) for part-based and(More)
Android application is an important class on today's Internet. While understanding app-specific behavior is important for network operation and management, it is often difficult because it requires an in-depth application-layer protocol analysis due to the common use of HTTP(S) and standard data representations (e.g., JSON). This paper presents Extractocol,(More)
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