The Experts below are selected from a list of 1947 Experts worldwide ranked by ideXlab platform
Gui Weihua - One of the best experts on this subject based on the ideXlab platform.
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research on optimal Fractional Bit minwise hashing
Computer Science, 2012Co-Authors: Yuan Xinpan, Long Jun, Zhang Zuping, Luo Yueyi, Gui WeihuaAbstract:In information retrieval,minwise hashing algorithm is often used to estimate similarities among documents,and b-Bit minwise hashing is capable of gaining substantial advantages in terms of computational efficiency and storage space by only storing the lowest b Bits of each(minwise) hashed value(e.g.,b=1 or 2).Fractional Bit minwise hashing has a wider range of selectivity for accuracy and storage space requirements.For the fixed fraction f,there are so many combinations of f.We theoretically analyzed limited combinations of Fractional Bit.The optimal Fractional Bit was found.Experimental results demonstrate the effectiveness of this method.
Yuan Xinpan - One of the best experts on this subject based on the ideXlab platform.
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research on optimal Fractional Bit minwise hashing
Computer Science, 2012Co-Authors: Yuan Xinpan, Long Jun, Zhang Zuping, Luo Yueyi, Gui WeihuaAbstract:In information retrieval,minwise hashing algorithm is often used to estimate similarities among documents,and b-Bit minwise hashing is capable of gaining substantial advantages in terms of computational efficiency and storage space by only storing the lowest b Bits of each(minwise) hashed value(e.g.,b=1 or 2).Fractional Bit minwise hashing has a wider range of selectivity for accuracy and storage space requirements.For the fixed fraction f,there are so many combinations of f.We theoretically analyzed limited combinations of Fractional Bit.The optimal Fractional Bit was found.Experimental results demonstrate the effectiveness of this method.
E Bonek - One of the best experts on this subject based on the ideXlab platform.
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suppression of the irreducible errors in a frequency selective fading channel by Fractional Bit differential detection
IEEE Transactions on Vehicular Technology, 1994Co-Authors: I Crohn, E BonekAbstract:The irreducible errors in digital mobile communications with high data rate in low-delay-spread channels are mainly caused by time dispersion (frequency selectivity) of the channel. The errors originate in the transition regions between adjacent symbols when deep fades occur. We show that Fractional-Bit differential detection with proper timing avoids these transition regions and decreases the irreducible errors. Assuming an MSK modulation format and slow Rayleigh fading, we derive a formula for calculation of the error probability in which we apply an "effective delay spread." A procedure to predict the effective delay spread is proposed. We verify the calculated error probability by a Monte Carlo software simulation for three different delay power profiles. The approach increases the tolerable delay spread in an unequalized receiver by a factor of 2 to 5 depending on the details of the delay power profile. Filtering the MSK signal tends to smear the transition region over the entire symbol duration, reducing the effectiveness of Fractional-Bit detection. This explains qualitatively the mismatch between theory and experiment in previously published results. We discuss the conditions of filtering and of finite signal-to-noise ratio (SNR) under which Fractional-Bit detection is effective. For instance, for a delay spread around one-tenth of the symbol length, improvement is gained if the SNR is above 15 dB. >
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Fractional Bit detection with advanced sampling to combat multipath induced error floor
Vehicular Technology Conference, 1993Co-Authors: I Crohn, G Schultes, J Fuhl, E BonekAbstract:In digital mobile communications, the error floor caused by time dispersion of the channel limits data rate even in low delay spread situations. The errors originate in the transition regions between adjacent symbols when deep fades occur. A detection method to reduce these errors, i.e., Fractional Bit differential detection with sample timing which is advanced from the average mean excess delay, avoiding the transition regions, is analyzed. Assuming a minimum shift keying (MSK) modulation format, the error probability is calculated and verified by a Monte Carlo software simulation. The approach increases the tolerable delay spread in an unequalized receiver, depending on the details of the delay power profile. These are accounted for by introducing an effective delay spread. Limiting the bandwidth tends to smear the transition regions over the entire Bit duration, thus offsetting part of the method's benefit.
Luo Yueyi - One of the best experts on this subject based on the ideXlab platform.
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research on optimal Fractional Bit minwise hashing
Computer Science, 2012Co-Authors: Yuan Xinpan, Long Jun, Zhang Zuping, Luo Yueyi, Gui WeihuaAbstract:In information retrieval,minwise hashing algorithm is often used to estimate similarities among documents,and b-Bit minwise hashing is capable of gaining substantial advantages in terms of computational efficiency and storage space by only storing the lowest b Bits of each(minwise) hashed value(e.g.,b=1 or 2).Fractional Bit minwise hashing has a wider range of selectivity for accuracy and storage space requirements.For the fixed fraction f,there are so many combinations of f.We theoretically analyzed limited combinations of Fractional Bit.The optimal Fractional Bit was found.Experimental results demonstrate the effectiveness of this method.
Zhang Zuping - One of the best experts on this subject based on the ideXlab platform.
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research on optimal Fractional Bit minwise hashing
Computer Science, 2012Co-Authors: Yuan Xinpan, Long Jun, Zhang Zuping, Luo Yueyi, Gui WeihuaAbstract:In information retrieval,minwise hashing algorithm is often used to estimate similarities among documents,and b-Bit minwise hashing is capable of gaining substantial advantages in terms of computational efficiency and storage space by only storing the lowest b Bits of each(minwise) hashed value(e.g.,b=1 or 2).Fractional Bit minwise hashing has a wider range of selectivity for accuracy and storage space requirements.For the fixed fraction f,there are so many combinations of f.We theoretically analyzed limited combinations of Fractional Bit.The optimal Fractional Bit was found.Experimental results demonstrate the effectiveness of this method.
