基于LDO限流技术的辐射闩锁防护技术

讨论了CMOS器件受辐射感生的闩锁与电气感生的闩锁的异同点，研究并提出了一种基于限流型低压降线性调整器的闩锁防护方法，给出了卫星用线性调整器电路的地面总剂量摸底试验数据及空间飞行试验验证结果和解决星载计算机的闩锁防护与恢复问题的有效方法．     

Turbo码删截序列全相关特性的进一步研究

在统计的基础上用全相关的概念对相关序列的全相关持性进行了深入的分析和研究，证明了有关全相关的几个定理和性质，给出了具体的例子，并推导出了计算相关序列之间相同组合数的简化算法，对Turbo码的删截序列进行了分析和计算，对几个不同的交织器求出了不同的删截矩阵所对应的删截序列之间的全相关函数值，通过模拟仿真显示删截序列之间的全相关特性也是影响Turbo码误码特性的一个重要因素，从而为交织器的设计，删截矩阵的选取又提供了一个理论上的依据。     

Circuit of time-domain quality factor measurement in 0.35μm CMOS process

Based on the time-domain quality factor (Q-factor) measurement principle, an architecture which not only achieves an accurate Q-factor at the specific frequency but also covers a range of frequencies without any loss in Q-factor measurement accuracy is proposed. Based on a reconfigurable structure, an improved peak detector compensation method is presented. To guide the design of such an architecture, a theoretical analysis for reaching the required accuracy and expanding the input frequency range has been first developed in this paper. Besides, the system power dissipation can be reduced by 7.5％ thanks to the improved digital control logic. In this paper, circuit is realized in a 0.35μm CMOS process for the first time. With the 5V supply voltage and 1MHz input frequency, the post-layout simulation result have demonstrated that an accuracy of the Q-factor measurement is within 0.2％. Furthermore, the input frequency range that can be measured by this circuit is extended from 100kHz to 1.5MHz with the same accuracy.     

A web based DSS for the management of floods and wildfires (FLIRE) in urban and periurban areas

The FLIRE DSS is a web-based Decision Support System for the combined forest and flood risk management and planning. State of the art tools and models have been used in order to enable Civil Protection agencies and local stakeholders to take advantage of web based DSS with no need of local complex infrastructure and maintenance. Civil protection agencies can predict the behavior of a fire event using real time data and in that way to plan its efficient elimination. Also, they can implement “what-if” scenarios for areas prone to fire and thus develop plans for forest fire management. Flood services include flood maps and flood-related warnings; these become available to relevant authorities for visualization and further analysis on a daily basis. Real time weather data from ground stations provide the necessary inputs for the calculation of the fire model in real time and a high resolution weather forecast grid support flood modeling and “what-if” scenarios for the fire modeling. The innovations of the FLIRE DSS are the use of common Earth Observation (EO) data as the backbone of the system to produce data for the support of fire and flood models, the common use of weather related information, the distributed architecture of the system and the web-based access of it with no need for installation of dedicated software. All these can be accessed by all means of computer sources like PC, laptop, Smartphone and tablet either by normal network connection or by using 3G and 4G cellular network. The latter is important for the accessibility of the FLIRE DSS during firefighting or rescue operations during flood events. FLIRE DSS can be easily transferred to other areas with similar characteristics due to its robust architecture and its flexibility.     

An energy-aware self-adaptive System-on-Chip architecture for real-time Harris corner detection with multi-resolution support

The proliferation of embedded vision in today’s life has necessitated the development of System-on-Chips to perform utmost processing in a single chip rather than discrete components. Embedded vision is bounded by stringent requirements, namely real-time performance, limited energy, and adaptivity to cope with the standards evolution. In this article, an energy-aware self-adaptive System-on-Chip for real-time corner detection is realized on Zynq All Programmable System-on-Chip using Dynamic Partial Reconfiguration. A careful analysis of algorithm and efficient utilization of Zynq resources results in highly parallelized and pipelined architecture outperforms the state-of-the-art. A context-aware configuration scheduler application is developed to adhere to operating context and trades off between video resolution and energy consumption to sustain the uttermost operation time for battery-powered devices while delivering real-time performance. The experiments show that the self-adaptive method achieves 1.77 times longer operation time than a parametrized IP core, with negligible reconfiguration energy overhead. A marginal effect of partial reconfiguration overhead on performance is observed, for instance, only two video frames are dropped for HD1080p60 during the reconfiguration time.     

Kinetic Monte Carlo simulation of GaN epitaxy

A chemical reaction mode about GaN epitaxy in MOCVD is presented. We simulate the growth process of GaN in the vertical-spray MOCVD system on this mode using the KMC mothod. The result shows that adductive reaction mostly occurs at a lower temperature and pyrolytic reaction mostly occurs at a high temperature. And the growth rate increases with increasing temperature. This feature determines the surface morphology of the material. We also include the diffusion and desorption process of the reaction particle by the KMC method. These processes depend mostly on temperature and ultimately affect the surface morphology of the GaN material.     

Higherorder singular value decomposition- and total variation- regularized multiplicative noise removal model

Smoothness, sparsity and self-similarity are the priors widely used in image denoising due to their importance in representing natural images. Motivated by the collaborative roles of higher order singular value decomposition and total variation regularization, a new approach that can simultaneously capture the above priors is proposed in this paper for removing the multiplicative noises. By taking advantages of local adaptiveness, sparsity and self-similarity realized by higher order singular value decomposition, the proposed approach starts with similar-patch-group-wise adaptive denoising on the log-transformed image, followed by the iterative optimization implemented by the total variation constraint which considers the prior of smoothness. Experiments demonstrate the advantages of the proposed approach in removing multiplicative noise and preserving the details near the edges and in the texture area.     

Wideband Fabry-Perot cavity antenna

In order to improve the radiation bandwidth of the Fabry-Perot Cavity (FPC) antenna, a new approach has been proposed, namely employing a tapered corrugation structure on the ground plane. To verify the proposed method, a wideband high-gain FPC antenna is designed. By introducing the corrugation structure, the height of the cavity can be gradually reduced. In this way, the phase of the radiation field can be compensated, which leads to a well-distributed radiation aperture. Therefore, the 3dB gain bandwidth can be enhanced. This structure is calculated by the CST Microwave Studio. The results validate the proposed approach, which helps 3dB gain bandwidth improvement from 17％ to 24％. Moreover, the 10dB impedance bandwidth and the maximum realized gain remain unchanged, that is, 35.7％ and 14.7dBi, respectively. This design can be widely used in many applications, such as wireless communication, due to its relatively wide bandwidth.     

Highly efficient VLSI architecture for DWT with low-storage implementation

With the gradual increase in image resolution of the spacecraft camera, it is highly required to figure out the problem how to process a huge amount of image data on board at a high speed. As a solution, the CCSDS proposes a space-oriented image-coding standard. For the sake of high image-coding performance, it adopts wavelet transformation as a method of image data transformation. However, wavelet transformation contains multi-level data processing, which causes more computational time consumption and more memory utilization. In order to solve this problem, we propose a highly efficient VLSI architecture for DWT with low-storage. By revising the traditional lifting structure and employing time-multiplex data processing strategy to perform the second and third level of wavelet transformation by the same logic module, the usage of logic resource is reduced with no sacrifice on speed.Using a small amount of on-chip memory instead of off-chip memory to save certain parts of DWT coefficients and sending the coefficients in a specific sequence to entropy coder timely, the off-chip memory for storage of DWT coefficients is no longer required. The proposed VLSI architecture of DWT is already implemented on the Xilinx FPGA XC4VSX55, which can achieve a high performance, in terms of data throughput, reaching 95.91MPixels/s.     

Support driven recovery algorithm for non-convex compressed sensing

A novel method is presented for the purpose of recovering sparse high dimensional signals from few linear measurements, especially in the noisy case. The proposed method works in the following two steps: ①The support of signal is approximately identified via Thresholded Basis Pursuit(TBP), the weighting matrix and parameters needed for the next step are also computed; ②The Iteratively Reweighted Lp Minimization(IRLp) procedure is used to solve the non-convex objective function. As theoretic interpretation and simulation results show, lower computational complexity is required for the proposed Support Driven IRLp(SD_IRLp) algorithm for high probability recovery, in comparison to 7 analogous methods(including an oracle estimator).