Evaluate the Gray Code in Distributed Fields for Tracking

Xianyun Wu,Kai Liu,Jinyan Cao,Yunsong Li,Li Wang 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.11

Distribution Fields (DFs) for tracking achieved a better performance than traditional algorithms due to its special representation that allows smoothing the objective function without destroying information about pixel values. DFs descriptor can satisfy both the specificity and smooth landscape requirements of a good tracking algorithm. In this paper, we evaluate the Gray code in original DFs algorithm by replacing the pixel values using Gray code instead of original binary code. Experimental results show that the Gray code can improve the tracking efficiency in certain way.

Novel driver circuit for switching performance improvements in SiC MOSFETs

Li, Xianyun,Lu, Yi,Ni, Xijun,Wang, Shuzheng,Zhang, Yu,Tang, Xinjie The Korean Institute of Power Electronics 2020 JOURNAL OF POWER ELECTRONICS Vol.20 No.6

Silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (MOSFETs) are expected to be an attractive replacement for Si MOSFETs in high power applications due to their high blocking voltage, high switching speed, and low switching losses. However, a high switching speed can lead to voltage and current overshoot as well as oscillation during the switching process, which results in additional losses and severe electromagnetic interference. It can also exceed the limit of the SiC MOSFET and cause irreversible damage to the device. Based on an analysis of the SiC MOSFET switching process voltage and current overshoot and oscillation generation mechanism, a voltage-injected active gate driver (AGD) was proposed. The proposed AGD can suppress the voltage and current overshoot and oscillation by injecting voltage into the gate of the SiC MOSFET during specific switching stages. Experimental results show that when compared with the conventional gate driver (CGD), the proposed AGD can suppress the voltage and current overshoot peaks by 16% and 12%, while reducing voltage and current oscillation times by 58% and 31%, respectively.

Role of soy lecithin combined with soy isoflavone on cerebral blood flow in rats of cognitive impairment and the primary screening of its optimum combination

Li Hongrui,Wang Xianyun,Li Xiaoying,Zhou Xueyang,Wang Xuan,Li Tiantian,Xiao Rong,Xi Yuandi 한국영양학회 2023 Nutrition Research and Practice Vol.17 No.2

BACKGROUND/OBJECTIVES: Soy isoflavone (SIF) and soy lecithin (SL) have beneficial effects on many chronic diseases, including neurodegenerative diseases. Regretfully, there is little evidence to show the combined effects of these soy extractives on the impairment of cognition and abnormal cerebral blood flow (CBF). This study examined the optimal combination dose of SIF + SL to provide evidence for improving CBF and protecting cerebrovascular endothelial cells. MATERIALS/METHODS: In vivo study, SIF50 + SL40, SIF50 + SL80 and SIF50 + SL160 groups were obtained. Morris water maze, laser speckle contrast imaging (LSCI), and hematoxylineosin staining were used to detect learning and memory impairment, CBF, and damage to the cerebrovascular tissue in rat. The 8-hydroxy-2′-deoxyguanosine (8-OHdG) and the oxidized glutathione (GSSG) were detected. The anti-oxidative damage index of superoxide dismutase (SOD) and glutathione (GSH) in the serum of an animal model was also tested. In vitro study, an immortalized mouse brain endothelial cell line (bEND.3 cells) was used to confirm the cerebrovascular endothelial cell protection of SIF + SL. In this study, 50 μM of Gen were used, while the 25, 50, or 100 μM of SL for different incubation times were selected first. The intracellular levels of 8-OHdG, SOD, GSH, and GSSG were also detected in the cells. RESULTS: In vivo study, SIF + SL could increase the target crossing times significantly and shorten the total swimming distance of rats. The CBF in the rats of the SIF50 + SL40 group and SIF50 + SL160 group was enhanced. Pathological changes, such as attenuation of the endothelium in cerebral vessels were much less in the SIF50 + SL40 group and SIF50 + SL160 group. The 8-OHdG was reduced in the SIF50 + SL40 group. The GSSG showed a significant decrease in all SIF + SL pretreatment groups, but the GSH showed an opposite result. SOD was upregulated by SIF + SL pretreatment. Different combinations of Genistein (Gen)+SL, the secondary proof of health benefits found in vivo study, showed they have effective antioxidation and less side reaction on protecting cerebrovascular endothelial cell. SIF50 + SL40 in rats experiment and Gen50 + SL25 in cell test were the optimum joint doses on alleviating cognitive impairment and regulating CBF through protecting cerebrovascular tissue by its antioxidant activity. CONCLUSIONS: SIF+SL could significantly prevent cognitive defect induced by β-Amyloid through regulating CBF. This kind of effect might be attributed to its antioxidant activity on protecting cerebral vessels.

Radionuclide identification method for NaI low-count gamma-ray spectra using artificial neural network

Sheng Qi,Shanqiang Wang,Ye Chen,Kun Zhang,Xianyun Ai,Jinglun Li,Haijun Fan,Hui Zhao 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.1

An artificial neural network (ANN) that identifies radionuclides from low-count gamma spectra of a NaIscintillator is proposed. The ANN was trained and tested using simulated spectra. 14 target nuclides wereconsidered corresponding to the requisite radionuclide library of a radionuclide identification devicementioned in IEC 62327-2017. The network shows an average identification accuracy of 98.63% on thevalidation dataset, with the gross counts in each spectrum Nc ¼ 100~10000 and the signal to noise ratioSNR ¼ 0.05e1. Most of the false predictions come from nuclides with low branching ratio and/or similardecay energies. If the Nc>1000 and SNR>0.3, which is defined as the minimum identifiable condition, theaveraged identification accuracy is 99.87%. Even when the source and the detector are covered with leadbricks and the response function of the detector thus varies, the ANN which was trained using nonshieldingspectra still shows high accuracy as long as the minimum identifiable condition is satisfied. Among all the considered nuclides, only the identification accuracy of 235U is seriously affected by theshielding. Identification of other nuclides shows high accuracy even the shielding condition is changed,which indicates that the ANN has good generalization performance.

Diffusion-Weighted MRI for the Initial Viability Evaluation of Parasites in Hepatic Alveolar Echinococcosis: Comparison with Positron Emission Tomography

Jianjun Zheng,Jing Wang,Jianqing Zhao,Xianyun Meng 대한영상의학회 2018 Korean Journal of Radiology Vol.19 No.1

Objective: More than 70% of hepatic alveolar echinococcosis (HAE) are inoperable. Thus, long-term, or even life-long, pharmacological treatment with benzimidazoles is necessary. For effective treatment, it is of great importance to employ imaging techniques to detect and monitor the non-resectable parasitic viability. Therefore, this study aimed to evaluate diffusion-weighted imaging (DWI) in assessing the viability of HAE in comparison to 18-fluoro-deoxyglucose (18F-FDG) positron emission tomography, combined with computed tomography (PET/CT). Materials and Methods: Positron emission tomography, computed tomography and DWI (b-values: 0, 800 s/mm2) were retrospectively analysed in eight patients with clinically-verified HAE to, generate the apparent diffusion coefficient (ADC) map. The activity of HAE lesions in both techniques were determined independently by two radiologists according to the following standard: (+), marked focally or perilesionally increased FDG uptake/high signal intensity; (−), a hepatic defect without FDG uptake/no high signal intensity. Every lesion’s maximum standardized uptake value (SUVmax) on the PET/CT images and mean ADC values on the parametric ADC maps were measured respectively. Results of PET/CT and DWI were compared on a per-lesion-basis. Pearson’s correlation coefficient was assessed for statistical analysis. Results: A total of 14 HAE lesions were detected. Eight lesions (diameter 3−15 cm) showed perilesional hyper-signal intensity on DWI. This was visualised on PET/CT as increased FDG uptake. They mainly existed in the lesion’s border with normal liver parenchyma. Five lesions (diameter < 2 cm) were detected as nodular hyperintensity on DWI and a ‘hot spot’ on PET/CT in the same distribution. One patient, who had received oral drug therapy for three years showed significantly decreased perilesional hyperintensity on the DWI and a hepatic defect without any FDG uptake on PET/CT. Pearson’s correlation coefficient indicated a significant inverse correlation of the ADC and the SUVmax (r = -0.67, p < 0.001). Conclusion: Diffusion-weighted imaging is capable of offering information on visually detecting the HAE lesions’ viability and may be useful for routine application in the initial diagnosis of HAE.

A Two-Step Noise Estimation Algorithm for Noisy Speech Enhancement

Shifeng Ou,Chao Geng,Xianyun Wang,Ying Gao 보안공학연구지원센터(IJSIP) 2013 International Journal of Signal Processing, Image Vol.6 No.5

Ethanol dry reforming over ordered mesoporous Co-Zn composite oxide for syngas production

Feifei Li,Jiale Dong,Mingyue Wang,Xingtao Lin,Weijie Cai,Xianyun Liu 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.7

This work is mainly concerned with the synthesis of Co-Zn nanocomposites by employing MCM-41 silicaas hard template (CoZnO-HT) and its catalytic behavior toward to CO2 reforming with ethanol. The physicochemicalfeatures of the as-prepared catalysts were probed through various characterization techniques, including XRD, TEM,BET, H2-TPR, and XPS. Indeed, CoZnO-HT catalyst possessed a highly ordered mesostructure with similarity toMCM-41 template and a higher specific surface area (304m2/g) compared to the reference CoZnO-C sample (4.75m2/g) prepared by the conventional impregnation method. Consequently, CoZnO-HT exhibited good performance at lowtemperature, and full ethanol conversion could be achieved at 550 oC as well as the negligible formation of byproductacetone. In addition, this catalyst depicted good stability and no obvious deactivation was observed after 40 h time onstream tests under the stoichiometric feed ratio. Indeed, superior specific surface area and efficient mass transportwithin the mesopores might be critical factors assigned to better activity and stability for CoZnO-HT.