We introduce the Rank M-type L (RM L) -filter to remove impulsive and speckle noise from corrupted images by means of use of DSP TMS320C6701.

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Recently, a data-selective method has been proposed to achieve low misalignment in affine projection algorithm (APA) by keeping the condition number of an input data matrix small. We present an improved method, and a complexity reduction algorithm for the APA with the data-selective method. Experimental results show that the proposed algorithm has lower misalignment and a lower condition number for an input data matrix than both the conventional APA and the APA with the previous data-selective method.

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A novel algorithm for source location by utilizing the time-difference-of-arrival (TDOA) of a signal received at spatially separated sensors is proposed. The algorithm is based on the constrained total least-squares (CTLS) technique and gives an explicit solution. Simulation results demonstrate that the proposed algorithm has high location accuracy and its performance is close to the Cramer-Rao lower bound (CRLB).

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An anonymous identity based encryption (anonymous IBE) scheme requires that an adversary can not determine the identity of the recipient from a ciphertext encrypted by the corresponding public key. The anonymity was formalized in previous works [1], [13], and this can be considered under chosen plaintext attack and adaptive chosen ciphertext attack, yielding two notions of security, ID-II-CPA and ID-II-CCA, where II denotes “indistinguishability of identities.” However, how to obtain an ID-II-CCA secure anonymous IBE in the random oracle model is still a challenging problem. We firstly propose a new notion of plaintext awareness in the two identities setting, called PATI. Secondly, we prove that the IBE scheme is ID-II-CCA secure if it is PATI secure. Finally, we propose the first generic conversion for anonymous IBE from ID-II-CPA to ID-II-CCA in the random oracle model.

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This letter proposes an identity-based authenticated key agreement protocol. Different from available comparable ones, the new protocol realizes implicit authentication without bilinear pairings which makes it more efficient. The security of proposed protocol can be reduced to the standard Computational Diffie-Hellman problem. Two variants of the protocol are also given, with one achieving the security-efficiency trade-off and the other providing authenticated key agreement between users of different domains.

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Abdalla et al. proposed a gateway-oriented password-based authenticated key exchange (GPAKE) protocol among a client, a gateway, and an authentication server, where a password is only shared between the client and the authentication server. The goal of their scheme is to securely establish a session key between the client and the gateway by the help of the authentication server without revealing any information on the password to the gateway. Recently, Byun et al. showed that Abdalla et al.'s GPAKE is insecure against undetectable on-line password guessing attacks. They also proposed a modified version to overcome the attacks. In this letter, we point out that Byun et al.'s modified GPAKE protocol is still insecure against the same attacks. We then make a suggestion for improvement.

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In this letter, we suggest a simple way of implementing a post-FFT pilot-assisted sampling frequency offset and residual frequency offset estimator with reduced complexity in an orthogonal frequency division multiplexing (OFDM) system. In order to devise the low-complexity post-FFT frequency estimator, some modifications on the conventional estimator are highlighted with an emphasis on the selection of pilot subset.

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An extension of the traditional color-based visual tracker, i.e., the continuously adaptive mean shift tracker, is given for improving the convenience and generality of the color-based tracker. This is achieved by introducing a probability density function for pixels based on the hue histogram of object. As its merits, the direction and size of the tracked object are easily derived by the principle component analysis (PCA), and its extension to three-dimensional case becomes straightforward.

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Efficient use of information technology (IT) is considered a major determinant of an end-user's business performance and an enterprise's competitiveness. A 16-item tool that can efficiently measure end-user information competency is presented with the measures. The validity and reliability of the tool is confirmed, and the tool's theoretical and practical applications are discussed.

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