基于改进残差特征蒸馏的轻量级超分辨率网络

基于深度学习的图像超分辨率算法通常采用递归的方式或参数共享的策略来减少网络参数，这将增加网络的深度，使得运行网络花费大量的时间，从而很难将模型部署到现实生活中。为了解决上述问题，本文设计一种轻量级超分辨率网络，对中间特征的关联性及重要性进行学习，且在重建部分结合高分辨率图像的特征信息。首先，引入层间注意力模块，通过考虑层与层之间的相关性，自适应地分配重要层次特征的权重。其次，使用增强重建模块提取高分辨率图像中更精细的特征信息，以此得到更加清晰的重建图片。通过大量的对比实验表明，本文设计的网络与其他轻量级模型相比，有更小的网络参数量，并且在重建精度和视觉效果上都有一定的提升。     

Low area field-programmable gate array implementation of PRESENT image encryption with key rotation and substitution

Lightweight ciphers are increasingly employed in cryptography because of the high demand for secure data transmission in wireless sensor network, embedded devices, and Internet of Things. The PRESENT algorithm as an ultra-lightweight block cipher provides better solution for secure hardware cryptography with low power consumption and minimum resource. This study generates the key using key rotation and substitution method, which contains key rotation, key switching, and binary-coded decimal-based key generation used in image encryption. The key rotation and substitution-based PRESENT architecture is proposed to increase security level for data stream and randomness in cipher through providing high resistance to attacks. Lookup table is used to design the key scheduling module, thus reducing the area of architecture. Field-programmable gate array (FPGA) performances are evaluated for the proposed and conventional methods. In Virtex 6 device, the proposed key rotation and substitution PRESENT architecture occupied 72 lookup tables, 65 flip flops, and 35 slices which are comparably less to the existing architecture.     

Using deep learning to combine static and dynamic power analyses of cryptographic circuits

Side-channel attacks have shown to be efficient tools in breaking cryptographic hardware. Many conventional algorithms have been proposed to perform side-channel attacks exploiting the dynamic power leakage. In recent years, with the development of processing technology, static power has emerged as a new potential source for side-channel leakage. Both types of power leakage have their advantages and disadvantages. In this work, we propose to use the deep neural network technique to combine the benefits of both static and dynamic power. This approach replaces the classifier in template attacks with our proposed long short-term memory network schemes. Hence, instead of deriving a specific probability density model for one particular type of power leakage, we gain the ability of combining different leakage sources using a structural algorithm. In this paper, we propose three schemes to combine the static and dynamic power leakage. The performance of these schemes is compared using simulated test circuits designed with a 45-nm library.     

Environmental impact estimation of ceramic lightweight aggregates production starting from residues

Within a circular economy approach, this study investigates the environmental impact of lightweight aggregates (LWAs) produced starting from different mixes of different clays with brewery sludge and cattle bone flour ash (CBA), used as poring and fertilizing agents, respectively. The environmental impact was evaluated by means of release tests, insulation capacity, carbon footprint (CFP), and particulate matter emission during pellet firing. Release tests representative of LWAs realistic application showed very high release of phosphate and satisfactory release of potassium. The thermal insulation of the LWAs was tested by thermal imaging camera and resulted highly variable depending on the composition, with the mix containing CBA performing best. This latter composition leads also to the smallest CO₂ equivalent emission, due to the calorific power of CBA, allowing lower consumption of fossil fuels during the LWA production. Finally, total particulate emissions during the thermal treatment resulted similar in terms of mass for all mixes, while differences in terms of particle morphology and composition occurred. Samples containing residue resulted with a quite good release behavior, CFP, and insulation properties, but higher emission of particles, particularly when glass is added.     

Lightweight,Elastomeric, and Flame‐Retardant Foams from Expanded Chlorinated Polymers

Intrinsically flame‐retardant polymers based on lightweight and elastomeric microcellular foams are successfully prepared from flexible chlorinated polyethylene (CPE)/chlorinated polyvinylchloride (CPVC) compounds through compression molding foaming technology. The incorporation of CPVC to CPE at once improves the foam characteristics, and enhances the mechanical and fire performances. Due to the plausible intermolecular and intramolecular crosslinking among the polymer chains, the dense network structure of CPE/CPVC with enhanced strength results in increased cell size, reduced cell density, and improved dimensional stability of CPE/CPVC foams (CCFs). These improvements are noticed to be enhanced with increasing CPVC content in the CCF. Also, the flame‐retardant properties of the foams (i.e., limiting oxygen index and cone calorimeter combustion) are found to be increased with the increase of CPVC content. For instance, a highly flame‐retardant CCF at CPE/CPVC ratio of 60/40 shows a shorter combustion period, as derived from the respective heat release rate vs time curve. Corresponding peaks of heat release rate, total heat release rate, peak of mass loss rate, total smoke release, and char residue are recorded to be 8.4%, 5.8%, 3.0%, 6.6%, and 1000.1% of those recorded for the pristine CPE foam.     

机床结构轻量化设计研究进展

对机床进行优化的结构构型设计,使得材料在机床结构空间内更加合理地分布和有效地利用,一直都是机床设计工作者追求探索的目标。论述机床构型和结构件轻量化设计的研究历程和技术发展,对机床结构轻量化设计中常用的现代设计方法:参数优化、结构拓扑优化、多方法综合结构设计、仿生优化设计方法进行具体技术介绍和综合评述,并对近年兴起的仿生优化设计方法进行从方法、实现手段和轻量化效果等方面重点分析和评述,对机床构型和结构件轻量化设计研究的未来发展提出展望。     

Low-cost and two-cycle hardware structures of PRINCE lightweight block cipher

In this paper, low-cost and two-cycle hardware structures of the PRINCE lightweight block cipher are presented. In the first structure, we proposed an area-constrained structure, and in the second structure, a high-speed implementation of the PRINCE cipher is presented. The substitution box (S-box) and the inverse of S-box (S-box⁻¹) blocks are the most complex blocks in the PRINCE cipher. These blocks are designed by an efficient structure with low critical path delay. In the low-cost structure, the S-boxes and S-boxes⁻¹ are shared between the round computations and the intermediate step of PRINCE cipher. Therefore, the proposed architecture is implemented based on the lowest number of computation resources. The two-cycle implementation of PRINCE cipher is designed by a processing element (PE), which is a general and reconfigurable element. This structure has a regular form with the minimum number of the control signal. Implementation results of the proposed structures in 180-nm CMOS technology and Virtex-4 and Virtex-6 FPGA families are achieved. The proposed structures, based on the results, have better critical path delay and throughput compared with other's related works.     

轻量化12R22.5无内胎全钢载重子午线轮胎的设计

介绍轻量化12R22. 5无内胎全钢载重子午线轮胎的设计。结构设计:外直径1 073 mm,断面宽295 mm,行驶面宽度218 mm,行驶面弧度高4. 5 mm,胎圈着合直径568. 5 mm,胎圈着合宽度248 mm,断面水平轴位置(H1/H2) 1. 13,胎面采用3条折线形主花纹沟和局部小刀槽花纹,花纹深度16. 5 mm,花纹饱和度71%,花纹周节数66。施工设计:采用双复合挤出胎面,采用4层带束层结构,1~#带束层采用0. 37+6×0. 32ST钢丝帘线,2~#和3~#带束层采用3×0. 20+6×0. 35HT钢丝帘线,4~#带束层采用5×0. 35HI钢丝帘线,胎体采用3×0. 24/9×0. 225CCST钢丝帘线,采用一次法成型机成型、双模硫化机硫化。成品性能试验结果表明,轮胎的充气外缘尺寸、强度性能、耐久性能和胎圈耐久性能等达到相应设计和标准要求。     

高效可撤销的身份基在线离线加密方案

身份基加密（IBE）需要提供一种有效的成员撤销机制，然而，现有可撤销成员的IBE方案存在密钥更新和加密运算量过大的问题，可能使执行该操作的设备成为系统的瓶颈。将完全子树方法和在线离线技术相结合，通过修改指数逆类型IBE的密钥生成和加密算法，提出了一种高效可撤销的身份基在线离线加密方案。方案利用完全子树方法生成更新钥，使得撤销用户无法获得更新钥，进而失去解密能力；利用在线离线技术，将大部分加密运算在离线阶段进行预处理，使得在线阶段仅执行少量简单计算即可生成密文。与相关知名方案相比，该方案不仅提高密钥生成中心的密钥更新的效率，而且极大减少了轻量级设备的在线加密工作量，适合于轻量级设备保护用户隐私信息。