Search

Cross-range scaling plays an important role in the inverse synthetic aperture radar (ISAR) imaging. Many of the published cross-range scaling algorithms are based on the fast Fourier transformation (FFT). However, the FFT technique is resolution limited, so that the FFT-based algorithms will fail in the rotation velocity (RV) estimation of the slow rotation target. In this paper, we propose an accurate cross-range scaling algorithm based on the multiple signal classification (MUSIC) method. We first select some range bins with the mono-component linear frequency modulated (LFM) signal model. Then, we dechirp the signal of each selected range bin into the form of sinusoidal signal, and utilize the super-resolution MUSIC technique to accurately estimate the frequency. After processing all the range bins, a linear relationship related to the RV can be obtained. Eventually, the ISAR image can be scaled. The proposal can precisely estimate the small RV of the slow rotation target with low computational complexity. Furthermore, the proposal can also be used in the case of cross-range scaling for the sparse aperture data. Experimental results with the simulated and raw data validate the superiority of the novel method.

An improved model for device proton SEU cross section simulation is established totally based on heavy ion test data. The model is deduced from the assumption that an injecting heavy ion with a certain LET value will just generate a SEU cross section value corresponding to the LET value at the heavy ion test data. Based on the assumption, the model has special sub-volume collection efficiency, which makes the SEU cross section simulation result through the model independent of critical charge (Qcrit). The modeling method is verified by heavy ion and proton test data of Xilinx XC2V1000 and XC4VSX55 FPGA. The difference of proton SEU cross section between simulation result and test data is less than 69% above 40 MeV of proton.

Background: Airway inflammation plays a pivotal role in cold asthma. Winyanghuayin decoction and Xiaoqinglong decoction can significantly improve airway inflammation. The aim of the present study was to explore the therapeutic effect and mechanism of Winyanghuayin decoction and Xiaoqinglong decoction on OVA-induced cold asthma in rat and compare the effects of Winyanghuayin decoction and Xiaoqinglong decoction for treatment of cold asthma ratsMethods: The cold asthma rat model was induced by OVA and ice water swim stress, treated with Winyanghuayin decoction and Xiaoqinglong decoction respectively. The pulmonary function of asthmatic rats was detected by MIR Spirolab; The pathological changes of lung tissue were observed by HE staining; The autophagy in the lung of rats were observed by transmission electron microscopy; The eosinophils, lymphocytes, macrophages and total cells in bronchoalveolar lavage fluid (BALF) were counted under light microscope. The expression of IL-10\IL-13\TNF-α and TGF-β1 in serum were measured by enzyme-linked immunosorbent assay (ELISA); The protein level of LC3-II\I, ATG, PI3K and mTOR expression in lung tissues were detected by Western blot; Real-time polymerase chain reaction (RT-PCR) detected the expression of autophagy gene ATG3\ATG5\ATG7 and ATG12.Results: Winyanghuayin decoction and Xiaoqinglong decoction can alleviate airway inflammation and improve airway hyper-responsiveness, significantly increased the level of autophagy in lung tissue and decreased the protein level of PI3K and mTOR in lung tissue of cold asthma rats. Winyanghuayin decoction have better regulation ability on autophagy and PI3K-mTOR signaling pathway.Conclusion: Winyanghuayin decoction and Xiaoqinglong decoction may alleviate the airway inflammation symptoms by enhancing autophagy in lung tissue dependent on the PI3K-mTOR signaling pathway. Winyanghuayin decoction was more effective than Xiaoqinglong decoction for treatment of cold asthma.

The interaction mechanism of three types of vena cava filters (VCFs) with blood vessels and their influence on the bloodstream during the process of implantation are investigated by finite element method and computational fluid dynamics. The VCF models are set up with Solidworks software. Using ABAQUS software, we simulate the working conditions of the VCFs in the vessel to analyze the stress distribution and radial support stiffness of the vessel wall and the filter surface. Using FLUENT software, we simulate and analyze the velocity, pressure and shear stress distributions of blood flow when the VCFs are at their working conditions. For the retrievable VCF (R-VCF), the peak stress at the working conditions of the VCF is the highest, the peak stress toward the vessel wall is the lowest, and the support stiffness is the lowest. For the permanent VCF (P-VCF), the peak stress at the working conditions of the VCF is the highest, the peak stress toward the vessel wall is the lowest, and the support stiffness is the highest. Because of the structure of scaffolding support units and the tendency to form intimal hyperplasia on their support units, both the convertible VCF (C-VCF) and the P-VCF can embed their support units in the hyperplasia skin. This effectively prevents them from harming blood veins through filter damage at the pulse load conditions. As the biomechanical property of the C-VCF is between those of the R-VCF and the P-VCF, it has smaller obstacle to blood flow after conversion and has some fragmentation effects on the thrombus. The results show that different types of VCFs differ in their biomechanical and hemodynamic properties after implantation. Therefore, the simulative analysis can provide a reference basis for filter design and clinical decision making.

Because of the high integration, low cost and high performance, SRAM FPGAs are becoming increasingly attractive in space missions. However SRAM FPGAs are vulnerable to SEU , so SEU protective measures must be taken and the fault-tolerant capability of FPGA application should be evaluated before it was deployed on obit. In this paper, the relationship between the number of SEU and error probability of SRAM FPGAs was studied by a model, and this relationship was validated by both fault injection and heavy ion irradiation experiment. Then on the base of it, a quick method to evaluate the upper bounder of the error probability for the FPGA application was proposed, and by this method, the error probability of the FPGA’s application can be achieve by fewer fault injection campaigns.

Some key parameters of model used in proton SEU cross section simulation are not easy to get. By setting sub-volume collecting efficiency and dimension from heavy ion test data, a model totally based on heavy ion test data is established, which is independent of critical charge. The modeling method is verified by heavy ion and proton test data of Xilinx XC2V1000 and XC4VSX55 FPGA. The difference of proton SEU cross section between simulation result with the established model and test data is less than 41% above 40MeV of proton.

we present a model for analyzing the mitigation improvement of single event upset (SEU) for triple modular redundant (TMR)-Field Programmable Gate Arrays (FPGAs) to energetic protons. Based on the cross section versus proton energy curve by Weibull fit, system failure rates of Non-TMR and TMR designs for Xilinx Virtex-4 FPGA were calculated as an example to explain this model. Energetic proton test data was shown to fit the model. Analysis result showed that TMR and scrubbing mitigation could decrease the system failure rate to 18.5 times compared with Non-TMR, and the test result was 14.8 times. The deviation between the analysis and test was about 20%.

The project presents the design of a low supply voltage detection circuit, working under 1 V of power supply. There are mainly three parts in this project of low supply voltage detector. These three parts are design of voltage reference, design of class AB amplifier and system design of low supply voltage detector. Master of Science (Integrated Circuit Design)

This paper describes an overview of a high-speed parallel signal processor that has been developed for a PRC phase-coded CW radar. It is a MIMD machine that consists of three subprocessors. Each subprocessor performs the beam signal processing tasks, and the architecture of the subprocessor is a static multi-function macropipeline. The processing speed of the signal processor is 2400 million operations per second (MOPS). The subclutter visibility (SCV) reaches 114 dB.

Objectives gastric mucosal lesion induced by dual antiplatelet (aspirin combined with clopidogrel) is an universal concern of the first and second prevention of Coronary heart disease. This study is to observe the repair effect of panax quinquefolius saponin on gastric mucosal lesion induced by dual antiplatelet drug. Methods 36 SD rats, ligate left anterior descending coronary artery as experimental Acute Myocardial Infarction (Acute Myocardial Infarction, AMI) model. The successful operation of rats were randomly and equally divided into AMI model group (distilled water 2 ml/kg/d by gavage, 12 rats), dual antiplatelet group (aspirin 9 mg/kg/d and clopidogrel 6.75 mg/kg/d by gavage, 12 rats), dual antiplatelet and PQS group (dual antiplatelet and PQS 162 mg/kg/d by gavage, 12 rats), The other 12 rats were regarded as Sham-operated group (Only puncture not ligation of coronary artery, distilled water 2 ml/kg/d by gavage,12 rats) After duplicating the mould 2nd days, distinguish to infuse by corresponding the soup feeding 28 days. Then under 4% chloral hydrate anaesthesia, Blood plasma were collected by abdominal aortic method, To measure serum gastrin (GAS), nitric oxide (NO), interleukin (IL) 1 β (IL- 1 beta), tumour necrosis factor alpha (TNF alpha) and plasma motilin (MTL), endothelin (ET 1) content, and the changes of histology and ultrastructure of gastric mucosa were observed. Results Gastric mucosa damage index (Guth score) and pathological grading index of Sham-operated group (Whittle score) and AMI group were zero, Compared with the AMI group, the gastric mucosa Guth score and Whittle score of dual antiplatelet group were significantly increased ( P ). Compared with the dual antiplatelet group, dual antiplatelet and PQS group gastric mucosa congestion reduced, inflammatory cell infiltration reduced, stomach surface cells were relatively complete. The Guth score and Whittle score were significantly decreased ( P ). Compared with the AMI group, dual antiplatelet group rats plasma ET- 1, MTL, serum IL- 1 β, TNF alpha content elevated significantly (P Conclusions PQS has a certain effect for repairing gastric mucosa damage induced by dual antiplatelet. The mechanism may be related to promoting GAS, NO protection factor formation, reducing inflammatory factor IL- 1 β, TNF alpha secretion, reducing ET- 1, MTL damage factor formation.