Recognizing human activities in a sequence is a challenging area of research in ubiquitous computing. Most approaches use a fixed size sliding window over consecutive samples to extract features— either handcrafted or learned features—and predict a single label for all samples in the window. Two key problems emanate from this approach: i) the samples in one window may not always share the same ...

We consider optimal control problems for a class of hybrid systems with switches dependent on an external event process. In the case where all event times in this process are fully known, the solution to such problems was obtained in prior work. When event times are uncertain or unknown, we have proposed a Receding Horizon (RH) control scheme in which only some future event information is avail...

This paper considers the proposed algorithm submitted to theMusic Information Retrieval Evaluation eXchange(MIREX) 2011 “AudioMelody Extraction” task. The proposed melody pitch extraction algorithm can be divided into three steps: (1) a spectral analysis using variable length window, (2) a pitch candidate estimation, and (3) a pitch sequence identification. In the first step, the short-time Fou...

This paper extends results concerning efficient exponentiation in groups where inversion is easy (e.g. in elliptic curve cryptography). It examines the right-to-left and left-to-right signed fractional window (RL-SFW and LR-SFW) techniques and shows that both RL-SFW and LR-SFW representations have minimal weight among all signed-digit representations with digit set {±1,±3, . . .,±m, 0}. (Fracti...

In this paper, the performance of the carrier sense multiple access with collision avoidance (CSMA/CA) protocol at MAC layer with sensing errors at physical layer is investigated. Here the sensing errors are captured by modifying the Markov chain model widely used for the CSMA/CA analysis called Bianchi’s model. We investigate the throughput as a function of carrier sensing error probabilities:...

In this article, a comprehensive study on uncertainty principle of the local polynomial Fourier transform (LPFT) is presented. It shows that the uncertainty product of the LPFT of an arbitrary order is related to the parameters of the signal and the window function, in addition to the errors of estimating the polynomial coefficients. Important factors that affect resolutions of signal represent...

A family of comparison-based exact pattern matching algorithms is described. They utilize multi-dimensional arrays in order to process more than one adjacent text window in each iteration of the search cycle. This approach leads to a lower average time complexity by the cost of space. The algorithms of this family perform well for short patterns and middle size alphabets. In such case the shift...

We consider optimal control problems for a class of hybrid systems with switches dependent on an external event process. In the case where all event times in this process are fully known, the solution to such problems was obtained in prior work. When event times are uncertain or unknown, we propose a Receding Horizon (RH) control scheme in which only some future event information is available w...

A weighted median filter is a nonlinear digital filter consisting of a window of length 2N + 1 and a weight vector W -(W-N . . . . . Wo . . . . . WN). A root signal of a median type filter is a signal that is invariant to the filter. However, not all weighted median filters possess the convergence property. In this paper, we shall study the root structures and the convergence behavior of a subc...

We consider optimal control problems for a class of hybrid systems with switches dependent on an external event process. In the case where all event times in this process are fully known, the solution to such problems was obtained in prior work. When event times are uncertain or unknown, we have proposed in prior work a Receding Horizon (RH) control scheme in which only some future event inform...