查看更多>>摘要：In this paper our objective is to explore approaches of secure group-oriented communication with designation and revocation mechanisms simultaneously. We present a new scheme of Revocation-based broadcast encryption (RBBE) which is designed on Dan Boneh et al.'s scheme with the designation mechanism proposed in 2005. We combine two above-mentioned schemes into a new cryptosystem, called Dual-mode broadcast encryption (DMBE). Based on these work, we reach the following conclusions. We use the DMBE scheme as an example to show that it is feasible to construct a broadcast en-cryption scheme that supports designation and revocation mechanisms simultaneously. The cryptosystem with dual modes is more efficient than that with single mode over computational costs, and the performance is improved to at most O((「)N/2(」)), where N is the total number of users in the system. We prove completely that both the RBBE scheme and the DMBE scheme are semantically secure against chosen plaintext attack with full collusion under the decisional bilinear Diffle-Hellman exponent assumption.
查看更多>>摘要：Linear codes have been an interesting topic in both theory and practice for many years. Based on the theory of defining set, a class of three-weight and five-weight linear codes over prime field Fp are constructed, which is an extension of Wang et al.'s construction. Our construction include some optimal codes and almost optimal codes with respect to the Singleton bounds. We employ exponential sums to investigate the weight distributions of these linear codes. The results show that these codes can be used to construct secret sharing schemes.
查看更多>>摘要：In this paper, we consider the depth distribution of constacyclic codes over Z4 with length even prime power. The depth distribution of negacyclic codes over Z4 of length 2e is completely determined. Furthermore, we determine the depth spectrum of cycilc codes over Z4 of length 2e, and the depth distribution of some cyclic codes over Z4 of length 2e is also given.
查看更多>>摘要：Emotions often facilitate interactions among human beings, but the big variation of human emotional states make a negative effect on the reliable emotion recognition. We propose a novel algorithm to extract common features for each type of emotional states which can reliably present human emotions. To uncover the common features from uncertain emotional states, the backward cloud generator is used to discover {Ex, En, He} by integrating randomness and fuzziness. Finally, the proposed method for emotion recognition is verified on the common facial expression datasets, the Extended Cohn-Kanade (CK+) dataset and the Japanese female facial expression (JAFFE). The results are satisfactory, which shows cloud model is potentially useful in pattern recognition and machines learning.
查看更多>>摘要：As a complex system, the topology of human's brain network can be analyzed by graph theory for the further study of brain's structural and functional mechanism. In order to construct and analyze the graph-based network efficiently and intuitively, it is necessary to develop flexible and independent visualization software. For this purpose, we developed an innovative software called VisConnectome. It runs on Windows system and does not rely on Matlab. It provides a friendly Graphical user interface (GUI) including the tool bar, the tool window, double slider, filter double slider, etc. It allows visualizing the brain network with the ball-and-stick geometric model, modifying its properties such as size and color, filtering nodes and connection as a simplification, blending with the brain surface as a context, etc. By experiments and comparison, we conclude that the VisConnectome is a flexible and independent visualization system with high speed and high quality.
查看更多>>摘要：Khudra is a lightweight block cipher proposed in SPACE 2014. The cipher is designed for Field programmable gate array (FPGA) based platforms. In this paper, we introduce the first biclique attack on full Khudra in the single key setting, with time complexity of 278.3 encryptions. The time complexity can be further reduced if the post-whitening key is omitted. Furthermore, based on the bicliques constructed, Meet-in-the-middle(MITM) attack is applied to 15-round Khudra, and the best result of Khudra in terms of attacked rounds against MITM attack is achieved.
查看更多>>摘要：The prevalence of deep learning has inspired innovations in numerous research fields including community detection, a cornerstone in the advancement of complex networks. We propose a novel community detection algorithm called the Deep auto-encoded cluster-ing algorithm (DAC), in which unsupervised and sparse single autoencoders are trained and piled up one after another to embed key community information in a lower-dimensional representation, such that it can be handled easier by clustering strategies. Extensive comparison tests undertaken on synthetic and real world networks reveal two advantages of the proposed algorithm: on the one hand, DAC shows higher precision than the k-means community detection method benefiting from the integration of sparsity constraints. On the other hand, DAC runs much faster than the spectral community detection algorithm based on the circumvention of the time-consuming eigenvalue decomposition procedure.
查看更多>>摘要：A new parameter extraction method for Schottky barrier diodes is provided in this paper. Since the current model of Schottky barrier diodes is a nonlinear self-consistent equation, the nonlinear inconsistent equations set is composed of nonlinear model equations under different biases. The problem of solving nonlinear inconsistent equations set is transformed into an optimization problem. The global optimal solution of the parameters is obtained by genetic algorithm. Comparing with experimental data, the results indicate that the error of the method proposed by this paper is lower than that of Cheung method.
查看更多>>摘要：Variation in on-chip power supply continues to be a major challenge to limit circuit performance. To mitigate the impact of high-frequency voltage droop, a novel all-digital adaptive clock system is proposed. The adaptive clock system is composed of a droop detector and an adaptive clock generator, which directly stretch the clock period when the circuit suffers from the supply voltage droop. The droop detector circuit detects the VDD droop and the digital adaptive clock generator circuit selects the stretched clock to prevent timing-margin failures. The response time for droop detection and clock stretch can be as fast as one cycle. The whole scheme is used on a test circuit under SMIC 40nm CMOS process with a layout area of 900um*1100um. Post-layout simulation results demonstrate power reductions are 7％ at 1.1V and 15％ at 0.7V for a 10％ VDD droop, respectively.
查看更多>>摘要：The existing construction methods of Quantum Boolean functions (QBFs) are extended and simplified. All QBFs with one qubit and all local QBFs with any qubits are constructed. And we propose the concept of Generalized quantum Boolean functions (GQBFs). We find all GQBFs with one qutrit and all kinds of local GQBFs with any qutrits. The number of each of the four kinds of functions above is uncountably infinitely many. By using diagonal matrices, we obtain uncountably infinitely many non-local QBFs with any qubits and GQBFs with any qutrits. Infinitely many families of GQBFs with any qudits are obtained from the properties of projection matrices of known saturated orthogonal arrays.
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