摘要：化学取代是有效调节分子电导,产生多通道输运、量子干涉效应和其他机制的关键方法.但分子骨架和侧基之间存在复杂的相互作用,目前仍未被研究清楚.在本工作中,我们结合扫描隧道显微镜裂结实验技术和第一性原理计算方法,深入研究了具有不同σ和π侧基的分子电导.实验结果及理论分析表明,σ侧基的加入引起了分子前线轨道的对称性破缺并加剧了分子内散射,从而导致电导的降低.相反,π侧基引入了额外的电荷传输通道,实现了电荷传输的多通道效应,增加了分子的电导.这些发现为未来分子功能化和分子电子器件的设计提供了坚实的基础.

摘要：Traditional honeypot is in fact a "passive proactive" defense mechanism because it may lose the value entirely once the adversary has detected the existence of the static trap and bypassed *** work focuses on a Self-Election dynamic honeypot framework which aims to bewilder attackers by coordinating and switching roles periodically to form a huge dynamic *** this paper,we discuss the UDP Spokesman synchronization scheme and the Self-Election coordination method,perform the framework simulation of the dynamic array honeypot with NS2,carry out the prototype implementation by Java,and then validate the effectiveness and feasibility on the simulation and prototype *** promising results of applying this framework to mitigate the effects of attacks are shown and *** work demonstrates that the Self-Election dynamic array honeypot system is feasible and effective for proactive network confrontation.

摘要：Most of the existing image encryption schemes with the substitutlon-chltuslon structure are not secure and efficient. In this letter, a chaos-based pseudo-random bit generator with good statistical properties is proposed, where a simple post-processing by compressing is employed. A new adaptive image encryption scheme with the substitution-diffusion architecture is designed using the new pseu- do-random bit generator. In the scheme, the session key for the pseudo-random bit generator is dependent on the content of the image which ensures that the scheme can effectively resist knownplaintext and chosen-plaintext attacks. Theoretical analysis and computer simulation indicate that the proposed algorithm is efficient and highly secure.

摘要：There are a lot of security issues in block cipher *** analysis and enhanced design of a dynamic block cipher was ***,the safety of ciphertext was enhanced based on confusion substitution of S-box,thus disordering the internal structure of data blocks by four steps of matrix ***,the diffusivity of ciphertext was obtained by cyclic displacement of bytes using column ambiguity *** dynamic key was finally generated by using LFSR,which improved the stochastic characters of secret key in each of round of *** safety performance of proposed algorithm was analyzed by simulation *** results showed the proposed algorithm has a little effect on the speed of encryption and decryption while enhancing the ***,the proposed algorithm has highly scalability,the dimension of S-box and the number of register can be dynamically extended according to the security requirement.

摘要：As a joint-optimization problem which simultaneously fulfills two different but correlated embedding tasks （i.e., entity embedding and relation embedding）, knowledge embedding problem is solved in a joint embedding scheme. In this embedding scheme, we design a joint compatibility scoring function to quantitatively evaluate the relational facts with respect to entities and relations, and further incorporate the scoring function into the maxmargin structure learning process that explicitly learns the embedding vectors of entities and relations using the context information of the knowledge base. By optimizing the joint problem, our design is capable of effectively capturing the intrinsic topological structures in the learned embedding spaces. Experimental results demonstrate the effectiveness of our embedding scheme in characterizing the semantic correlations among different relation units, and in relation prediction for knowledge inference.

摘要：We introduce a novel strategy of designing a chaotic coverage path planner for the mobile robot based on the Che- byshev map for achieving special missions. The designed chaotic path planner consists of a two-dimensional Chebyshev map which is constructed by two one-dimensional Chebyshev maps. The performance of the time sequences which are generated by the planner is improved by arcsine transformation to enhance the chaotic characteristics and uniform distribution. Then the coverage rate and randomness for achieving the special missions of the robot are enhanced. The chaotic Chebyshev system is mapped into the feasible region of the robot workplace by affine transformation. Then a universal algorithm of coverage path planning is designed for environments with obstacles. Simulation results show that the constructed chaotic path planner can avoid detection of the obstacles and the workplace boundaries, and runs safely in the feasible areas. The designed strategy is able to satisfy the requirements of randomness, coverage, and high efficiency for special missions.

摘要：Head pose estimation has been considered an important and challenging task in computer vision. In this paper we propose a novel method to estimate head pose based on a deep convolutional neural network （DCNN） for 2D face images. We design an effective and simple method to roughly crop the face from the input image, maintaining the individual-relative facial features ratio. The method can be used in various poses. Then two convolutional neural networks are set up to train the head pose classifier and then compared with each other. The simpler one has six layers. It performs well on seven yaw poses but is somewhat unsatisfactory when mixed in two pitch poses. The other has eight layers and more pixels in input layers. It has better performance on more poses and more training samples. Before training the network, two reasonable strategies including shift and zoom are executed to prepare training samples. Finally, feature extraction filters are optimized together with the weight of the classification component through training, to minimize the classification error. Our method has been evaluated on the CAS-PEAL-R1, CMU PIE, and CUBIC FacePix databases. It has better performance than state-of-the-art methods for head pose estimation.

摘要：The standard software development life cycle heavily depends on requirements elicited from stakeholders. Based on those requirements, software development is planned and managed from its inception phase to closure. Due to time and resource constraints, it is imperative to identify the high-priority requirements that need to be considered first during the software development process. Moreover, existing prioritization frameworks lack a store of historical data useful for selecting the most suitable prioritization technique of any similar project domain. In this paper, we propose a framework for prioritization of software requirements, called Re Pizer, to be used in conjunction with a selected prioritization technique to rank software requirements based on defined criteria such as implementation cost. ReP izer assists requirements engineers in a decision-making process by retrieving historical data from a requirements repository. Re Pizer also provides a panoramic view of the entire project to ensure the judicious use of software development resources. We compared the performance of Re Pizer in terms of expected accuracy and ease of use while separately adopting two different prioritization techniques, planning game（PG） and analytical hierarchy process（AHP）. The results showed that Re Pizer performed better when used in conjunction with the PG technique.

摘要：A laterally diffused metal-oxide-semiconductor （LDMOS） device design with an enhanced p-well and double p-epitaxial structure is investigated for device ruggedness improvement while keeping its high device per- formance under high frequency. Based upon the device design, radio-frequency （RF） LDMOS transistors for GSM （global system for mobile communication） application have been fabricated by using 0.35/zm CMOS technolo- gies. Experimental data show that the proposed device achieves a breakdown voltage of 70 V, output power of 180 W. The RF linear gain is over 20 dB and the power added efficiency （PAE） is over 70% with the frequency of 920 MHz. In particular, it can pass the 20 ： 1 voltage standing wave ratio （VSWR） load mismatch biased at drain DC supply voltage of 32 V and output power at 10-dB gain compression point （P10dB）. The device ruggedness has been remarkably improved by using the proposed device structure.

摘要：The relay node with linear relaying transmits the linear combination of its past received *** optimization of two-hop relay channel with linear relaying is discussed in this *** capacity for the two-hop Gaussian relay channel with linear relaying is derived,which can be formulated as an optimization problem over the relaying matrix and the covariance matrix of the signals transmitted at the *** is proved that the solution to this optimization problem is equivalent to a "single-letter" optimization *** also show that the solution to this "single-letter" optimization problem has the same form as the expression of the rate achieved by Time-Sharing Amplify and Forward(TSAF).In order to solve this equivalent problem,we proposed an iterative *** results show that if channel gain of one hop is relatively smaller,the achievable rate with TSAF is closer to the max-flow min-cut capacity bound,but at a lower complexity.