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EFFECTS OF CYCLIC-NUCLEOTIDES AND CALCIUM ON TRANSDUCTION AND encoding processES IN FROG-MUSCLE SPINDLE

BRAIN RESEARCH 1988年第1-2期443卷 254-260页

作者： SOKABE, M FUJITSUKA, N KORI, AA ITO, F NAGOYA UNIV SCH MED DEPT PHYSIOL NAGOYA AICHI 466 JAPAN

In decapsulated muscle spindles, application of dibutyryl cyclic AMP (d-cAMP, 0.1-10 mM) and forskolin (10-100 .mu.M) increased the rate of spntaneous discharges and decreased the responsiveness to stretch. Addition of 2-5 mM CaCl2 or 0.5-2 mM BaCl2 to the above drugs prevented the deterioration of the responsiveness to stretch and the increase in the rate of spontaneous discharges. Similar changes in the afferent discharges were observed with application of isobutylmethyl-xanthine (IBMX 0.5-2 mM) or carbonyl cyanide chlorophenylhydrazone (CCCP, 1-10 .mu.M). Application of 0.1-1 mM quercetin resulted in a prolonged increase in the discharge rate, lasting 15-20 s after the result of stretch. These results suggest that cAMP is involved in the regulation of the sensory processes through a modification of intracellular calcium activity.

关键词： Frog muscle spindle Cyclic adenosine monophosphate (cAMP) Intracellular Ca 2+ Decapsulation encoding process Quercetin

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Scheme for variable-frequency digital circuit with data compression based on block-match process

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IET CIRCUITS DEVICES & SYSTEMS 2018年第3期12卷 295-300页

作者： Jin, Rencheng Zhao, Jipeng Ma, Yuan Zhou, Feng Dalian Univ Technol Res Ctr Microsyst Technol Dalian 116024 Peoples R China

In order to find a way to solve the contradiction among storage space, transmission capacity and the data volume in the embedded systems, a data compression scheme based on block matching with an identifier is presented by using the technology of digital integrated circuit. The scheme can achieve lossless real-time data compression and reduce the volume of the data. Through statistical analysis on the data source, the authors can obtain that such a scheme has many advantages in real-time performance, a complication of implement, efficiency and practicability. So the digital circuit is considered as a method which can present the encoding process. With the help of QUARTUS II, they combine Verilog and schematic to finish the design hierarchically and code the decompression program by using C language for comparison. The accuracy and efficiency of the circuit are verified with simulation and relevant experiments. The average compression rate is 52.3% with 12MHz clock frequency and the compression speed on average is 352% faster than the one by using block-match software algorithm. The scheme would have good performance in many embedded systems.

关键词： Verilog block-match software algorithm transmission capacity data compression variable-frequency digital circuit decompression program digital integrated circuits QUARTUS II data compression scheme block-match process encoding process embedded systems statistical analysis encoding digital integrated circuittechnology storage space C language data source frequency 12 MHz data volume reduction

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Dynamic threshold-based keyframe detection and its application in rate control

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IET IMAGE processING 2012年第7期6卷 986-995页

作者： Yao, W. Li, Z. Rahardja, S. Inst Infocomm Res Signal Proc Dept Singapore Singapore

This study proposes a new dynamic threshold model to detect keyframes for the coding of a video sequence. The proposed detection threshold is content adaptive which dynamically updates its value at each frame by taking into consideration both the statistical properties of the video sequence and the resolution as well as the quantisation parameters. The content variation metric used in the proposed detection method utilises the information that is already generated by the encoder during the encoding process and thus it makes the detection process fast. By applying the proposed scheme to rate control, the sizes of group of pictures are now adapted to the video content and it removes the temporal redundancy among different frames better, which transforms to the improvements on coding efficiency. The experimental results have shown that the proposed method achieves peak signal-to-noise ratio (PSNR) improvement.

关键词： image resolution statistical analysis temporal redundancy encoding process dynamic threshold model dynamic threshold-based keyframe detection coding efficiency Image and video coding rate control quantisation parameters quantisation (signal) encoder video coding image sequences peak signal-to-noise video resolution Video signal processing detection process content variation metric statistical properties video sequence coding PSNR Other topics in statistics

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Encryption scheme against eavesdropper collusion in wireless multi-user network

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IET COMMUNICATIONS 2020年第14期14卷 2387-2394页

作者： Huang, Ying Lei, Jing Li, Wei Natl Univ Def Technol Coll Elect Sci & Technol Changsha Hunan Peoples R China

In order to resist eavesdropper collusion attack in wireless multi-user network, the authors propose a distributed physical layer encryption (DPLE) scheme with energy-efficient design. The encryption is embedded into rateless coding at both user nodes and relay node. Meanwhile, data frame permutation is added at the relay for increasing randomness. It is noteworthy that the secret key is used as the seed of random number generator, which controls the encoding process and permutation. At receiver, the decryption is united with decoding process without any extra cost, which makes DPLE special in the field of lightweight security. There are two cases considered in security analysis for resisting collusion attack: without error and with error. Typical results are time complexity and attack success probability, respectively. Furthermore, the evaluation for algorithm implementation is investigated. The theoretic result and simulation show that the proposed scheme can combat colluding eavesdroppers by high complexity and very low attack success probability. Moreover, lower computation cost is achieved.

关键词： cryptography probability radio networks random number generation telecommunication security computational complexity wireless multiuser network eavesdropper collusion attack distributed physical layer encryption scheme energy-efficient design user nodes relay node data frame permutation increasing randomness random number generator encoding process DPLE special time complexity colluding eavesdroppers low attack success probability

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Fast fractal image compression algorithm using specific update search

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IET IMAGE processING 2020年第9期14卷 1733-1739页

作者： Zheng, Yunping Li, Xiangpeng Sarem, Mudar South China Univ Technol Sch Comp Sci & Engn Guangzhou Peoples R China Huazhong Univ Sci & Technol Sch Software Engn Wuhan Peoples R China Gen Org Remote Sensing Damascus Syria

The fractal image compression (FIC) algorithm is difficult to be widely used in real-time applications due to the huge consumption of its encoding time. Inspired by the fact that in the decoding process, for any original image, a fixed point is generated by the iterations of the fractal codes, the authors propose a specific update search FIC (SUSFIC) algorithm, which uses a scale number to control the update times of the fractal codes and to find acceptable matching domain blocks rather than the best ones in the selected domain blocks pool. To further reduce the computation time, in their proposed algorithm, the image blocks created by the equidistant sampling in the range of the original blocks are used to replace themselves when calculating the correlation coefficients as the distances between the adjacent domain blocks. The experimental results presented show that their proposed SUSFIC algorithm has a significant improvement in encoding time under the premise of setting an appropriate search update threshold and maintaining image quality when compared with the state-of-the-art FIC algorithms. Therefore, it is a better FIC algorithm.

关键词： fractals image coding image reconstruction data compression adjacent domain blocks SUSFIC algorithm encoding time appropriate search update threshold maintaining image quality state-of-the-art FIC algorithms fast fractal image compression algorithm real-time applications encoding process reconstructed image decoding process fractal codes specific update search FIC algorithm update times acceptable matching domain blocks selected domain blocks pool computation time image blocks original blocks

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General generative model-based image compression method using an optimisation encoder

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IET IMAGE processING 2020年第9期14卷 1750-1758页

作者： Wu, Mengtian He, Zaixing Zhao, Xinyue Zhang, Shuyou Zhejiang Univ Sch Mech Engn State Key Lab Fluid Power & Mechatron Syst Hangzhou Peoples R China

Image compression is an intensively studied subject in computer vision. The deep generative model, especially generative adversarial networks (GANs), is a popular new direction for this subject. In this study, the authors propose a new compression method based on a generative model and focus on its application by GANs. The decoder in the proposed method is modified from the GAN generator model, which can produce visually real-like synthetic images. It is one of the two models in GANs, which is trained through a two-players' contest game. The encoder is an optimisation algorithm called backpropagation-to-the-input, which derives from an image inpainting algorithm based on generative models. In the proposed method, the authors turn the encoding process into an optimisation task to search for optimal encoded representations. Compared with traditional methods, the proposed method can compress images from certain domains into extremely small and shape-fixed encoded space but still retain better visual representations. It is easy and convenient to apply without any retraining or additional modification to the generative models.

关键词： backpropagation image restoration encoding optimisation image coding data compression computer vision general generative model-based image compression method optimisation encoder intensively studied subject deep generative model generative adversarial networks GANs GAN generator model synthetic images optimisation algorithm image inpainting algorithm generative models encoding process optimisation task optimal encoded representations extremely small shape-fixed encoded space

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Acceleration of fractal image compression using fuzzy clustering and discrete-cosine-transform-based metric

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IET IMAGE processING 2012年第7期6卷 1024-1030页

作者： Jaferzadeh, K. Kiani, K. Mozaffari, S. Semnan Univ Elect & Comp Dept Semnan Iran

The encoding step in a fractal image compression is very time consuming, because a large numbers of sequential search through a list of domains are needed to find the best match for a given range block. Adaptive domain clustering is one solution to overcome this computational burden. The use of a new metric with fewer operations for domain-range blocks comparison is fruitful. In this study, range and domain blocks are categorised by fuzzy c-mean-clustering approach and compared with the use of new metric based on discrete cosine transform coefficient. Experimental results show that by clustering image pixels into five clusters, the encoding step was 8.88 times faster than the full-search method (no clustering) at the expense of some reduction in the decoded image's quality. But the proposed method with the same number of clusters speeds up the encoding process by 45 with lower PSNR decay.

关键词： adaptive domain clustering discrete cosine transforms domain-range blocks comparison fractal image compression acceleration sequential search image quality decoding encoding process Computer vision and image processing techniques Image and video coding image coding fuzzy set theory Integral transforms pattern clustering discrete-cosine-transform-based metric fuzzy clustering decoding image pixels clustering encoding step Combinatorial mathematics fuzzy c-mean-clustering approach domain blocks fractals

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Design of expanding window fountain codes with unequal power allocation over BIAWGN channels

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IET COMMUNICATIONS 2016年第14期10卷 1786-1794页

作者： Yuan, Lei Li, Juan Wan, Yi Lanzhou Univ Sch Informat Sci & Engn Lanzhou 730000 Peoples R China

In this study, the authors propose an improved design of expanding window fountain (EWF) codes over the binary input additive white Gaussian noise channels. The encoding process is modified to get almost regular variable-node degree distributions. Compared with the conventional EWF codes, their proposed scheme can lower the error floor. Furthermore, they combine the EWF encoding process with unequal power allocation to improve unequal error protection (UEP) performance, and construct pre-coded EWF codes by concatenating their proposed EWF codes with high-rate low-density parity-check codes. Both asymptotic analysis and simulation results show that, compared with the conventional scheme, their proposed scheme can get better UEP performance and design flexibility.

关键词： AWGN channels parity check codes expanding window fountain codes unequal power allocation BIAWGN channels binary input additive white Gaussian noise channels encoding process almost regular variable-node degree distributions unequal error protection performance UEP performance precoded EWF codes high-rate low-density parity-check codes asymptotic analysis design flexibility

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Partial distortion search algorithm based on two-step d_min updating

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ELECTRONICS LETTERS 2011年第19期47卷 1076-1077页

作者： Pan, Z. B. Wu, X. P. Li, Y. Gao, F. Xi An Jiao Tong Univ Sch Elect & Informat Engn Xian 710049 Peoples R China

The encoding process of vector quantisation is computationally very expensive. To reduce distortion computation between the input vector and candidate codewords, the well-known partial distortion search (PDS) algorithm has been proposed. To reduce further its computational cost, a new PDS algorithm is proposed by making current d(min) decrease as quickly as possible. Experimental results have demonstrated the effectiveness of the proposed PDS algorithm in terms of both the computing dimensions and arithmetical operations per input vector.

关键词： encoding process arithmetical operation vector quantisation Codes partial distortion search algorithm codewords

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A modification of the Hartley information measure as applied to the problems of measurement techniques

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MEASUREMENT TECHNIQUES 2003年第8期46卷 748-750页

作者： Asadov, KG

A modification is proposed of the Hartley information measure which makes it possible to take into account the level of noise present in a signal. It is shown that the proposed modification is of a probabilistic natur... 详细信息

关键词： information measure noise level accompanying signal encoding process measuring system

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