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More and more hybrid brain-computer interfaces (BCI) supplement traditional single-modality BCI in practical applications. Combinations based on steady-state visual evoked potential (SSVEP) and electromyography (EMG) are the widely used hybrid BCIs. The EMG of jaw clench is commonly used together with SSVEP. This article explored the interference with SSVEP from occipital electrodes by the jaw clench-related EMG so that SSVEP with specific frequency can be identified even during occlusal movements. The experiment was divided into three sets base on the jaw clench patterns (no clenches, chew, and long clench). In each set, the subjects used the same visual stimuli, which were realized by the three flashing targets at different frequencies (6.2Hz, 9.8Hz, and 14.6Hz). After collecting the SSVEP at 4 sites in the occipital region, the SSVEP response spectrum of each stimulus was observed under the three jaw clench patterns. Then, the SSVEP signal was identified by the canonical correlation analysis method for accuracy statistics. Spectrum responses showed that the interference of the jaw clench EMG on SSVEP could be avoided when the stimulation frequency is lower than 20Hz. SSVEP could be identified based on the frequency domain characteristics of these signals. During steady-state visual stimulation with jaw clenches, the recognition rate of SSVEP was still high (no clenches: 100.0%, chew: 94.7%, and long clench: 100.0%). Through reasonable frequency selecting and signal processing, the influence of the jaw clench movement on the SSVEP could be reduced and a high recognition accuracy could be achieved, even the jaw clench actions and the SSVEP stimulation occur simultaneously.

To overcome the disadvantages of complex control, poor robustness and unstable output voltage of traditional doubly-fed induction generator grid-side converter, a double closed-loop control system of DC bus voltage outer loop based on active disturbance rejection control (ADRC) and current inner loop based on PID is designed. By controlling the output current of the converter, the purpose of maintaining the constant DC bus voltage of the PWM converter on the grid-side and keeping the output unit power factor of the stator side is achieved. Not only can good control effect be achieved, but also the hardware complexity of the system can be reduced and the utilization efficiency of the doubly-fed induction generator can be improved. The simulation results show that the double closed-loop control strategy can effectively maintain the DC bus voltage stability of the grid-side converter, ensure that the DC voltage fluctuation is small, reduce the voltage distortion rate, and have a strong anti-interference ability.

The prevalence and large-scale uptake of the Internet of Things (IoT) have led to a growing trend of Identification Exploding, namely heterogeneous entities respectively identified to provide convenient intelligent services. To address challenges under Identification Exploding, unified modeling has become a promising approach to generalizing identification for heterogeneous entities in IoT. This paper surveys and discusses Identification Exploding's background to explore the possibility of unified modeling as one of the solutions. Meanwhile, challenges of realizing unified modeling are discussed. After that, comprehensive reviews on the latest modeling approaches and methods covering various IoT entities are carried out, including sensed entities and sensing devices. Special attention has been paid to modeling under resource-constrained IoT environments and relevant modeling-based industry solutions with critical analysis. It is proved that unified modeling is extremely significant under Identification Exploding Tendency in the IoT era.

Combinations of steady-state visual evoked potential (SSVEP) and electromyography (EMG) are one of the most widely used hybrid brain-computer interfaces (BCI). For users who are suffering from severe motor impairments and could only control muscles above their necks, the EMG of jaw clench is commonly used together with SSVEP. Traditional asynchronous signal collecting and serial processing method is time-consuming. This study explored the simultaneous classification of SSVEP and jaw clench-related EMG from the same occipital electrodes. A convolutional neural network (CNN) model was adopted to classify the fusion signal after extracting different time and frequency domain features. Synchronous 12-class identification from 3 jaw clench patterns and 4 stimulate frequencies was tested on ten subjects. The 10-folder cross-validation results showed that using only 4 occipital electrodes, the CNN model with continuous wavelet transform feature achieved the overall best $89.3\pm4.0\%$ accuracy for sync 12-class. Besides, the parallel acquiring and analyzing method has the lowest consuming time. The proposed method could reduce the signal channels and shorten the collect-process time of the SSVEP-EMG hybrid BCI.

Space unmanned systems with modular and reconfigurable characteristics show a distributed spatial information processing scenario, which needs a new intelligent information processing architecture and task scheduling method, so as to make better use of on orbit resources, adapt to reconfigurable spatial computing and provide spatial reliability computing. we propose a dynamic computing resource and task allocation algorithm for modular reconfigurable space systems, by introducing Docker container technology to minimize completion time cost of a task for given resource constraints considering network traffic and variable workloads in a unified framework. The algorithm first answers the problem of how multiple modules perform cooperative and reliable computing in modular reconfigurable space systems, and gives a method to jointly optimize task allocating strategy and computing resource scheduling through online prediction and linear regression optimization in distributed environment. We design and implement the algorithm architecture on the Linux based platform, and perform series of tests on the simulated distributed network environment. The experiment results show that the algorithm has resource utilization and task response gain in various situations (different cluster node capabilities, different task response demands), obtain the cluster resource allocation balance, and minimize the total completion time of tasks.

The condition assessment and lifetime estimation methods of rubber O-ring seal used in gas-insulated metal-enclosed switchgear (GIS) has prospective significance. Previous research had built nonlinear models for the degradation of mechanical properties for O-rings, but this conflicted to the common-known linearity of oxygen consumption rate (OCR) which characterized the chemical aging rate. Perhaps this might be explained by the gradually losing of compressive stress, and the effort of this paper was to verify this explanation. In this paper, the thermal-compressive two-factor accelerated aging were conducted on GIS O-ring seals of two EPDM formulations. Determination methods of compression set (CS) and residual compression ratio (RCR) were proposed for GIS O-rings. The compression set at unit residual compression ratio (CSU) and its derivation (ARU) was derived. The results showed that CSU had good linearity with aging time and the trends of ARU was consistent with OCR, which verified the explanation.

The properties of the rubber seal ring determine the gas-tightness of the GIS. Previous research used the compression set as an important mechanical property to evaluate the aging of vulcanized rubber, but it is hard to be applied on retired seal ring sample due to its inaccessible initial data and non-standard shape. This paper proposed a test method for retired seal ring based on a new index, deformation recovery rate (DRR). Twenty-nine retired neoprene GIS seal ring samples including 4 from a faulty GIS, which have been in operation for $8 \tilde 30$ years were obtained and tested. Five new samples were also tested as a control. The results showed an exponential plot between DRR and operating time. Then, the ATR-FTIR was applied to identify the main chemical change during the aging process. The results showed a decrease of -CH3 and an increase of C=O, illustrating the chain scission and the oxidation of the rubber. The relation between carbonyl index and operating time was exponential function, too. Besides, EPDM rubber show stronger deformation recovery ability and antioxidant ability than CR. Faultage appeared on the surface and the increase of oxygen atom were detected, which demonstrated that oxidation and chain scission happened during the aging process. Compared the SF6 side to the air side of the seal ring, less protrusions and pits were observed on the surface, and significantly less C, more Si, F, and a small amount of Al, Fe, Zn were detected. The findings demonstrated that the seal ring may react with the flange, SFi gas or its decomposition gas.

The rise of cloud computing and cloud storage brings huge benefits to the information industry, but at the same time, related applications also face greater information security challenges. Therefore, this paper proposes a risk assessment method of cloud system information security based on risk contagion, which mainly evaluates the risk value of the whole system caused by a module being attacked as a risk source. In this method, the calculation of asset value is improved, and the permissions relationship is introduced into the calculation of risk contagion coefficient.

Nonlinear frequency modulation (NLFM) waveforms have been investigated in recent years. The main advantages of the waveform include fine resolution, good signal-to-noise ratio, and good interference mitigation. However, for synthetic aperture radar (SAR), there are hitherto no real applications of NLFM. It is known that Doppler intolerance is the drawback of NLFM waveform. Therefore, in this paper, the two-dimensional NLFM SAR signal model with Doppler shift is formulated and the influences of Doppler shift on airborne SAR imaging are analysed in detail. Furthermore, the first experimental result of airborne NLFM SAR is demonstrated.

With the growing cost of powering and cooling, the Dynamic Voltage Frequency Scaling (DVFS) technique has been adopted in many mobiles and embedded devices nowadays. However, attackers are capable of maliciously manipulating the DVFS to threaten application programs including the security related ones. This paper first proposes a test method to test the vulnerabilities of CPU instructions under the DVFS attack. The test program feature, the testability of CPU instructions, and the Test Program Generation Algorithm (TPGA) are proposed. It is applied to an arm CPU in a mobile phone. Typical instructions are tested, and some are found vulnerable. Then, based on the test result, a method for code optimization by instruction substitution is proposed. The application program using vulnerable instructions are then attacked and optimized to prove the effectiveness of the proposed methods.

With the growing cost of powering and cooling, the Dynamic Voltage Frequency Scaling (DVFS) technique has been adopted in many mobiles and embedded devices nowadays. However, attackers are capable of maliciously manipulating the DVFS to threaten application programs including the security related ones. This paper proposes an instruction-level Automatic Test Program Generation (iATPG) framework, which generates test programs to test the vulnerabilities of CPU instructions under the DVFS attack. The conditions that the test program needs to meet, the testability of CPU instructions, and the iATPG algorithm are proposed. It is applied to an arm CPU in a mobile phone. Typical instructions are tested, and some are found vulnerable. The application programs using these instructions are then attacked to prove the effectiveness of the proposed framework.

Logic design of a 16-bit bit-slice shifter for 64-bit superconducting rapid single-flux-quantum (RSFQ) microprocessors is proposed. The shifter supports three types of shift operations including logic shift, arithmetic shift and rotating shift. Each of 64-bit shift input operands is divided into four slices of 16-bit each. In order to simulate the digital function and timing of the proposed 16-bit bit-slice shifter, we design a logic-level simulation model based on the Open Dataset of CONNECT Cell Library for AIST ADP2. As the results of simulation, the information of RSFQ circuits, such as the number of Josephson junctions, area and latency of the 16-bit bit slice shifter can be obtained. The simulation results show that the proposed 16-bit bit-slice shifter can work correctly.

Domain-specific accelerators for graph analytics leverage a large on-chip memory in order to tackle the intensive random memory accesses, offering higher performance and energy efficiency than conventional architectures. However, limited by the inefficient usage of on-chip memory, current accelerators suffer from energy and performance bottlenecks due to the large amount of off-chip memory accesses. In this work, we introduce an online preprocessing step for the vertex-centric programming model based on our observation of imbalanced memory bandwidth utilization between two execution phases. Our scheme improves energy efficiency and performance by significantly reducing off-chip accesses in two ways. First, we sequence random off-chip memory accesses to balance memory bandwidth demands and improve the utilization of on-chip memory. Second, we prune active leaf vertices to avoid redundant memory accesses. We evaluate our method on a state-of-the-art graph analytics accelerator and achieve 1.6× speedup while reducing energy consumption by 42% on average.

Multichannel in azimuth synthetic aperture radar (SAR) operating in sliding spotlight imaging mode serves as an promising tool to achieve very-high resolution and wide-swath imaging of the earth surface. This paper investigates the aspect of phase mismatch calibration for multichannel sliding spotlight SAR imaging, and an extended azimuth cross correlation method is proposed to deel with the influence of beam rotation in azimuth. Processing with experimental data obtained by a C-band dual-channel sliding spotlight airborne SAR shows the effectiveness of channel phase mismatch cancellation.

An 8-bit bit-parallel RSFQ microprocessor, named HUTU, is proposed. It can execute 28 different instructions. Each instruction consists of eight bits. Harvard-type architecture is adopted for parallel processing between the control unit and the datapath. The control unit uses an asynchronous timing method to avoid pipeline flushing and to reduce the area. Concurrent-flow clocking is adopted in the datapath for high performance. The simulation result shows that the elements of HUTU run correctly.

An 8-bit bit-slice TEA-cryptographic accelerator for 64-bit RSFQ secure coprocessors is proposed. The accelerator is based on Tiny Encryption Algorithm (TEA) and mainly consists of bit-slice adders and bit-slice shifters. Synchronous concurrent-flow clocking is used to design a fully pipelined RSFQ logic design. For verifying the algorithm and the logic design, the RSFQ logic circuits of the proposed accelerator have been simulated with a target operating frequency of 50 GHz. It consists of 21 stages. The throughput is 7.672 × 107 64-bit TEA encryptions per second.

Rapid single-flux-quantum (RSFQ) is expected to be the next generation integrated circuit technology because of its ultra-high-speed with ultra-low-power consumption. We propose datapath circuits for an 8-bit bit-parallel RSFQ microprocessor. The proposed datapath circuits process 8-bit data each clock cycle. Seven instructions are executed in the datapath, including ADD, ADDI, IN, OUT, LOADI, SRL and MOV. The datapath circuits consist of eight input ports, eight output ports, five multiplexers (MUXs), two 8-bit data registers and one 8-bit bit-parallel arithmetic logic unit (ALU). The datapath circuits contain 12 pipeline stages and 2993 JJs based on the Open Dataset of CONNECT Cell Library for AIST ADP2 without considering wiring cells. We perform digital simulation of the proposed datapath circuits. The simulation results show correct operation with the assumed frequency of 20 GHz.

Gas-insulated substation (GIS) is rapidly popularized in the construction of large hydropower projects and urban highvoltage power grids. Pressured insulating gas sulfur hexafluoride (SF6) in the GIS is sealed by the rubber O-rings, namely GIS seal ring, and the lifetime prediction method for GIS seal ring has attracted attention of experts and scholars. Compression set of O-ring is one of the most important indices to determine the lifetime while the key is to accurately measure the cross-section diameter. In this paper, compression set for standard cylindrical specimen was reviewed, which was proposed for testing the vulcanized rubber material. The rubber thickness gauge was an instrument specially invented for testing dimension of rubber specimens. Then the characteristic of the cross-section of used GIS seal ring was analyzed. The cross-section has good axis symmetry, but the inclination of the axis challenges the measurement. To solve the problem, test method of determining compression set for O-rings based on the directional section diameter (DSD) was proposed. Given a direction k, the k-DSD is defined by the thickness of specimen measured in direction k, denotes $\boldsymbol{d}_{\mathbf{k}}$ . The $\boldsymbol{d}_{\mathbf{v}}$ and $\boldsymbol{d}_{\mathbf{p}}$ are two typical DSDs, that $\boldsymbol{d}_{\mathbf{v}}$ described thickness in vertical direction when placing the O-ring specimens on a flat plate in natural state, while $\boldsymbol{d}_{\mathbf{p}}$ is the shortest DSD. Finally, this paper conducted experiments on measuring $\boldsymbol{d}_{2}, \boldsymbol{d}_{\mathbf{v}}, \boldsymbol{d}_{\mathbf{p}}$ of new and used 252kV GIS seal ring samples by rubber thickness gauge and Vernier caliper. Statistical analysis of the data implies better precision and accuracy when measuring $\boldsymbol{d}_{\mathbf{p}}$ by a rubber thickness gauge. This paper provides reference for the lifetime prediction method for GIS seal ring.

Traditional TMR (Three Mode Redundancy) method based on homogeneous multicore has been used in solving the transient fault of microprocessor and improving reliability, but it is characterized by low performance and high power consumption. This paper proposes an improved TMR method to improve the performance of fault-tolerant scheduling for heterogeneous system (HEFT-ITMR). The tasks are divided into two groups with/without fault-tolerant requirements, which are scheduled by traditional TMR method and by competitive mechanism, respectively. The tasks without fault-tolerant requirements will be re-executed in traditional TMR method if the task reliability fail to meet the requirements. The experimental results demonstrate that the proposed method can achieve a 18.1% improvement in average efficiency over traditional TMR method when running three types of benchmark without injecting errors and yield an average speedup of 15.3% and the power consumption can also be decreased by 20.5% over TMR when 200 errors are injected. In addition, a parallel optimization method P-HEFT-ITMR is proposed to further improve system performance and reduce system power consumption while ensuring system reliability.

The explosion of data volume in big data era drives architecture designers to find more efficient processor architectures. Different from the conventional scientific computing, big data applications are usually simple computing patterns with massive input data, which makes current general-purpose processors suffer poor performance and huge energy consumption. Among various computing patterns in big data applications, string operations are common but very important parts of data processing. Dealing with simple and fixed computing patterns with high-performance processors is wasteful. In this paper, we propose WEAVER, a high-efficiency, general-purpose acceleration architecture for string operations, which can be integrated into current processors and work beside on-chip memory controller. The WEAVER can both reduce the latency of data transfer between memory and processing cores and accelerate the string processing by using customized architecture. The experimental results show WEAVER gains an average speedup of 3.2x over a general-purpose Intel processor, and reduces the energy consumption by 3.79x on average, with tiny hardware overhead.

The problem of SF 6 leakage in gas-insulated metal-enclosed switchgear (GIS) due to the aging failure of seal ring has been addressed by previous reports. Earlier efforts, however, do not reflect the particularity of GIS. In particular, the aging factors are not studied in-depth about their affecting mechanism, level, combination and circulation mode. This article gives comprehensive review on the study of GIS sealing principle, test methods and standards, and the lifetime prediction of GIS seal rings. In addition, a survey on mechanical property test method among seven major GIS manufacturers in China is done. This article aims to provide a research direction for the test methods and lifetime prediction of GIS seal rings.

The aim is to study the radar target tracking system for multi-sensor data fusion. Multi-sensor data fusion is important for achieving information complementarity, improving target tracking accuracy and recognition capabilities, and enhancing the system's anti-jamming. Aiming at the architecture of radar and infrared tracking, an information fusion algorithm based on radar and infrared sensor optimal data compression is proposed for single target tracking. Then, the algorithm of track correlation and track fusion in multi-target tracking is simulated and analyzed. The results show that the optimized algorithm improves the correct correlation rate of the track. The multi-sensor target fusion tracking can avoid the limitations of a single sensor, and improve the accuracy of target tracking. Therefore, it can be concluded that the designed radar infrared netted data fusion system has excellent anti-jamming performance. It greatly improves the target tracking accuracy.

Microstrip antenna array often use one point two power splitters cascading as feed network, at lower frequency such as C or S wave band, the insertion loss of network is weak, which made the performance of antenna array stable and efficient. At higher frequency as Ka wave band, however, the insertion loss cannot be ignored, because the electrical properties as gain of array will be deterioration obviously. Meanwhile, the element space is small at higher wave band, so the routing of feed lines became hard. For the large insertion and complex wiring shortcomings, this paper proposed a novel feed network for the microstrip antenna array, which avoids the traditional scheme of the ‘right-angle bend’ and ‘cutaway’. By comparing these two simulations feed network insertion loss and antenna array pattern, verified the new form has improved the antenna array gain and aperture efficiency significantly.

Since the echo characteristics of moving targets are different from the stationary scene, the traditional reconstruction algorithm, i.e., the reconstruction filter algorithm, is not applicable. In this paper, a novel reconstruction approach of the moving target for a multichannel in azimuth high-resolution wide-swath (HRWS) synthetic aperture radar (SAR) system, modified from the traditional reconstruction filter algorithm, is proposed. The core of this method is to solve the problem of reconstruction filter mismatch by adapting the motion parameters of the moving target. Compared with the reconstruction filter algorithm, this method can not only achieve the accurate reconstruction of the stationary scene, but also reconstruct the spectrum of the moving target with nice performance. The simulated results of point targets are shown to confirm the effectiveness of the proposed method.

According to the characteristics of different airborne synthetic aperture radar (SAR) imaging modes, a generalized sub-aperture autofocus scheme based on Doppler rate (DR) estimation is presented, which can well integrate into the existing multi-mode SAR imaging processor. In this scheme, suitable strategies for sub-aperture segmentation and Doppler rate errors (DREs) estimation are generated. Its effectiveness is validated by three airborne real data sets with different imaging modes, collected by the same C-band experimental system.

In this article, first the structure and performance of single carrier frequency domain equalization (SC-FDE) system are analyzed, and the minimum mean square error (MMSE) equalization algorithm is discussed for frequency selective fading channel. Next, the application of spatial modulation (SM) technology is introduced in SC-FDE system, and simulations are made to compare the bit error rate (BER) performance of SC-FDE systems with Alamouti space time coding, V-BLAST and SM, respectively. Finally, Trellis Coded Modulation (TCM) is considered to use in SM-SC-FDE system to suppress the influence of channel correlation on the system and improve the system performance.

Generalized Frequency Division Multiplexing (GFD-M) is a promising candidate waveform for the air interface of the fifth generation (5G) communication networks. The combination of GFDM and time-reversal space-time coding (TR-STC) can improve the bit error rate (BER) performance. In this paper, we employ Walsh-Hadamard Transform (WHT) in TR-STC-GFDM systems to further enhance the system performance over frequency-selective time-variant channels. Simulation results show that with slight increase in complexity, WHT can substantially reduce the BER of the STC-GFDM systems. Meanwhile, the peak-to-average power ratio (PAPR) of the system is also reduced.

According to the characteristics of the Doppler history in ScanSAR mode, a novel ship detector is presented based on the raw echo data. The proposed approach is very efficient, since it does not need the computational imaging process. Its effectiveness is validated by an airborne ScanSAR real data set, collected by a C-band experimental system.

In recent years, many studies on optimization of energy consumption have focused on heterogeneous processor architectures. Heterogeneous computing model composed of CPU and GPU has developed from co-processing between the chips to CPU and GPU integration on the same die. On the one hand, because GPU can work under low voltage and ultra-low frequency, heterogeneous multi-core processors exhibit better energy efficiency compared to traditional CPU; On the other hand, because GPU usually has little or no shared cache, its memory bandwidth demand will be several times more than that of CPU for the same performance. Considering the constraints of power consumption and memory bandwidth, the contention problems of power and bandwidth among CPU and GPU in heterogeneous processor will inevitably occur. In this paper, energy-efficient bandwidth allocation method for heterogeneous processors allocates bandwidth to CPU and GPU and increases the overall throughput of CPU and GPU. Meanwhile the efficiency of energy consumption of heterogeneous processors is improved. The queuing delay is introduced to build a performance-energy model for heterogeneous processors. According to experience parameters, we analyze how the memory bandwidth allocation of off-chip affects the total throughput and energy efficiency. This paper also explores the change of performance-energy gains with the cache miss ratio of processors and the degree of scarce of available peak bandwidth. Based on the above research, the analytical solution of energy-efficient bandwidth allocation for optimal performance is obtained, and the solution can get more performance-energy gains compared with natural bandwidth allocation.

The high parallelism feature of scientific applications makes SIMD very suitable for streaming dataflow architectures. However, the splitting of SIMD memory requests increases the messages in on-chip networks and decreases the efficiency of streaming dataflow architectures. To process SIMD memory requests without splitting, a memory partition mechanism is proposed for SIMD in streaming dataflow architectures. The mechanism partitions input data of scientific applications into N (SIMD width) independent sub-spaces equally and groups operations on different data with same locations in N sub-spaces into SIMD operation. Moreover, the mechanism merges data with the same location in different sub-spaces to SIMD data and stores SIMD data in same SPMs to process SIMD memory requests as a whole. Simulation experimental results show that the proposed mechanism improves the performance per watt of streaming dataflow architectures by 2.5× on average on typical scientific applications.

Elliptic Curve Cryptography (ECC) is becoming widely deployed in embedded cryptographic devices because of the reduced number of key bits. However, the side-channel attacks especially simple side-channel analysis (SPA) can obtain secret keys by measuring power consumption. To resist this attack there appear a number of countermeasures such as Montgomery ladder and double-and-add-always algorithm. This paper proposes a new simple power analysis attack to these countermeasures by distinguishing the conditional subtraction of Montgomery modular multiplication (MMM). Experimental results on smart cards demonstrate that this attack method can retrieve secret keys easily in several seconds using one power trace. Several countermeasures that can resist this kind of SPA attack are also demonstrated in this paper.

For optical flow algorithm complexity,computationally intensive, poor real-time drawbacks ,thispaper proposes a moving detection algorithm that combinewith optical flow method and three frame difference methodwhich be used OTSU to process. Choose the typical Harriscorner of extracting area to calculate, it can effectively reducethe complexity of the algorithm. Since moving target areadetection was not complete, the three-frame difference imagewhich be processed by OTSU binary image was introduced asa supplement of simplify the optical flow method. Through theexperiment, this method make the optical flow method satisfiedthe real-time request . Detect more complete area of themoving object.