A parallel architecture for efficient hardware implementation of Rivest Shamir Adleman (RSA) cryptography is proposed. Residue number system (RNS) is introduced to realize high parallelism, thus all the elements under the same base are independent of each other and can be computed in parallel. Moreover, a simple and fast base transformation is used to achieve RNS Montgomery modular multiplication algorithm, which facilitates hardware implementation. Based on transport triggered architecture (TTA), the proposed architecture is designed to evaluate the performance and feasibility of the algorithm. With these optimizations, a decryption rate of 106 kbps can be achieved for 1 024-b RSA at the frequency of 100 MHz.

With an improved Rayleigh fading model and a zero-mean stochastic sinusoid as the scattering and specular components respectively, a stochastic simulation model is proposed for the generation of Rayleigh and Rician fading waveforms. Compared with the existing stochastic models, the proposed simulator needs only one trial to obtain the desired statistical properties even if the number of samples is not large enough. Moreover, the proposed simulation model can directly generate multiple uncorrelated waveforms for different fading scenarios, such as single-input single-output frequency selective channels and multiple-input multiple-output channels. The performance evaluation and comparison show that the proposed simulator is efficient and accurate.

This paper proposes a compact polarization microstrip antenna based on double-layer structure. The bandwidth of the whole antenna is widened by expanding the top and bottom layers respectively. After the design of antenna structure and adjustment of size, the proposed antenna can achieve both the left- and right-hand circular polarizations in 2.33 GHz–2.97 GHz. Measurement results indicate that the effective bandwidth is 640 MHz in S-band and the relative bandwidth can achieve 24% with S ₁₁ less than −15 dB.

In order to improve the transmission accuracy and efficiency of sensing and actuating signals in Internet of Things (IoT) and ensure the system stability, an adaptive resource allocation algorithm is proposed, which dynamically assigns the network bandwidth and priority among components according to their signals’ frequency domain characteristics. A remote sensed and controlled unmanned ground vehicle (UGV) path tracking test-bed was developed and multiple UGV’s tracking error signals were measured in the simulation for performance evaluation. Results show that with the same network bandwidth constraints, the proposed algorithm can reduce the accumulated and maximum errors of UGV path tracking by over 60% compared with the conventional static algorithm.

An improved linear-time retiming algorithm is proposed to incrementally optimize the clock period, especially considering the influence of the in-out degree of the critical combinational elements. Firstly, the critical elements are selected from all the critical combinational elements to retime. Secondly, for the nodes that cannot be performed with such retiming, register sharing is implemented while the path delay is kept unchanged. The incremental algorithm can be applied with the technology mapping to minimize the critical path delay and obtain fewer registers in the retimed circuit with the near-optimal clock period. Compared with Singh’s incremental algorithm, experiments show that the proposed algorithm can reduce the flip-flop count by 11% and look-up table(LUT) count by 5% while improving the minimum clock period by 6%. The runtime is also reduced by 9% of the design flow.

An image fusion method combining complex contourlet transform (CCT) with nonnegative matrix factorization (NMF) is proposed in this paper. After two images are decomposed by CCT, NMF is applied to their highand low-frequency components, respectively, and finally an image is synthesized. Subjective-visual-quality of the image fusion result is compared with those of the image fusion methods based on NMF and the combination of wavelet /contourlet /nonsubsampled contourlet with NMF. The experimental results are evaluated quantitatively, and the running time is also contrasted. It is shown that the proposed image fusion method can gain larger information entropy, standard deviation and mean gradient, which means that it can better integrate featured information from all source images, avoid background noise and promote space clearness in the fusion image effectively.

An improved automatic voltage coordination control strategy (AVCCS) based on automatic voltage control (AVC) and battery energy storage control (BESC) is proposed for photovoltaic grid-connected system (PVGS) to mitigate the voltage fluctuations caused by environmental disturbances. Only AVC is used when small environmental disturbances happen, while BESC is incorporated with AVC to restrain the voltage fluctuations when large disturbances happen. An adjustable parameter determining the allowed amplitudes of voltage fluctuations is introduced to realize the above switching process. A benchmark low voltage distribution system including PVGS is established by using the commercial software DIg SILENT. Simulation results show that the voltage under AVCCS satisfies the IEEE Standard 1547, and the installed battery capacity is also reduced. Meanwhile, the battery’s service life is extended by avoiding frequent charges/discharges in the control process.

Microcystis aeruginosa FACHB 905 was used as a model organism to study the effects of small water clusters (SWCs) on the growth and microcystin (MC) production of toxic cyanobacteria. The results showed that SWCs were able to stimulate the growth of Microcystis aeruginosa, which resulted in increased cell numbers and higher specific growth rates after a 30-d treatment. The cell morphology indicated that Microcystis aeruginosa was in a better state of growth, and it was more prone to divide in SWCs than in normal water clusters. The SWCs treatment up-regulated MC synthesis and exudation in 10 d in Microcystis aeruginosa, and the intra-cellular MC content decreased after the 20th day subsequently. Moreover, the cellular photosynthetic pigment contents were temporarily stimulated by SWCs. A possible reason is that SWCs stimulated the growth by promoting photosynthesis, whereas the increased MC production was relevant to pigment contents.

An analytical model for predicting the corrosion-induced cracking of concrete cover of reinforced concrete (RC) structures was developed. The effects of influence factors such as practical initial defects, corrosion rate, strength and elastic modulus of concrete on the corrosion-induced cracking of concrete cover were investigated. It was found that the size of practical initial defects was the most effective factor. Therefore, improving the compactness of concrete is an effective way to improve the durability of RC structures. It was also demonstrated that the accelerated corrosion tests may be unfavorable in the study of the relationship between cracking time and crack width.

The orientation strategy of side pipe and the heat transfer performance of six ground heat exchangers (GHEs) were optimized by numerical simulation, with soil being treated as a porous medium. An experiment on the heat transfer of four GHEs was carried out in 2010. Results indicate that the velocity field is disturbed by GHEs. The optimal orientation strategy of side pipe is that the upward pipe is located upstream and the downward pipe downstream. The space between GHEs should be appropriately adjusted, depending on the direction and flow velocity. Groups of GHEs should be installed perpendicular to the mainstream in a single row, but if the acreage does not meet the requirements, GHEs should be installed in staggered multiple rows. Fewer GHEs parallel to the mainstream strengthen the heat transfer. Moreover, numerical results agree well with the test data, with the maximum relative error being less than 7.7%.

In autonomous underwater vehicles (AUVs) the onboard power used to complete missions is limited. To solve this problem, a landing AUV has been designed, which conserves energy by sitting on the seafloor while monitoring the ocean. In order to study the dynamic behaviors for better control of the AUV, the dynamic analysis of the landing AUV is presented in this paper. Based on the momentum theorem and the angular momentum theorem, the dynamic model of the landing AUV is derived. The simulations of rectilinear motion, rotary motion and helix motion indicate the dynamic behaviors of the AUV. The ocean experiments validate the dynamic model presented in this paper. The experiments also verify that the landing AUV can work for a longer time than common AUVs.

The expression of residual is obtained according to its dynamic response to mean shift, then the distribution of T ² statistic applied to the residual is derived, thus the probability of the T ² statistic lying outside the control limit is calculated. The above-mentioned results are substituted into the infinite definition expression of the average run length (ARL), and then the final finite ARL expression is obtained. An example is used to demonstrate the procedures of the proposed method. In the comparative study, eight autocorrelated processes and four different mean shifts are performed, and the ARL values of the proposed method are compared with those obtained by simulation method with 50,000 replications. The accuracy of the proposed method can be illustrated through the comparative results.

The current cost-plus natural gas pricing mechanism makes the gas price too low, resulting in a lot of consumer-side subsidies and over-consumed natural gas. This paper applies the price-gap approach and input-output analysis technology to quantitatively analyze both the direct and indirect effects on urban residents under the condition that natural gas subsidies are cancelled in China in 2007. It is shown that the gas price will increase by 33.3%–41.6%, and the residential consumption expenditure by 0.26%–0.33%. The low-income groups are mostly affected, so different subsidies should be implemented to make subsidies more efficient.