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Remote detection of alpha radiation source by optical method

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光电子快报:英文版 2023年第7期19卷 405-409页

作者： LI Ningning ZHANG Nan Institute of Modern Optics Nankai UniversityTianjin 300350China

To solve the problem that the conventional detection technique of alpha radiation sources is unable to achieve Remote detection and not suitable for detecting alpha radiation sources with complex morphology,Remote detection of alpha radiation sources by measuring the fluorescence induced by the interaction between alpha particles and nitrogen molecules is investigated in this paper.In dark conditions,nitrogen fluorescence is collected by the optical system with an aperture of 50 mm and detected by a photomultiplier tube working in the photon counting mode.The alpha radiation source with total activity of 7.3 k Bq and unit area activity of 49 Bq/cm^(2) can be detected within 30 s at a distance of 0.6 m.The detection limit of the alpha radiation source detection system proposed in this paper ranks among the top in the related research fields.

关键词： Remote source system

Multi-Attention Fusion and Fine-Grained Alignment for Bidirectional Image-Sentence Retrieval in Remote Sensing

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IEEE/CAA Journal of Automatica Sinica 2022年第8期9卷 1532-1535页

作者： Qimin Cheng Yuzhuo Zhou Haiyan Huang Zhongyuan Wang School of Electronic Information and Communications Huazhong University of Science and TechnologyWuhan 430074China State Key Laboratory of Information Engineering in Surveying Mapping and Remote SensingWuhan UniversityWuhan 430079China School of Computer Science Wuhan UniversityWuhan 430079China

Dear editor,Cross-modal retrieval in Remote sensing(RS) data has inspired increasing enthusiasm due to its merit in flexible input and efficient query. In this letter, we address to establish semantic relationship bet... 详细信息

关键词： editor Remote Image

Remote ischaemic conditioning for stroke: unanswered questions and future directions

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Stroke & Vascular Neurology 2021年第2期6卷 298-309页

作者： Sheharyar Baig Bethany Moyle Krishnan Padmakumari Sivaraman Nair Jessica Redgrave Arshad Majid Ali Ali Cerebrovascular Medicine The University of Sheffield Institute for Translational NeuroscienceSheffieldUK Neurosciences Sheffield Teaching Hospitals NHS Foundation TrustSheffieldUK Faculty of Medicine and Dentistry University of SheffieldSheffieldUK Geriatrics and Stroke Medicine Sheffield Teaching Hospitals NHS Foundation TrustSheffieldUK Sheffield NIHR Biomedical Research Centre The University of SheffieldSheffieldUK

Remote ischaemic conditioning(RIC)refers to a process whereby periods of intermittent ischaemia,typically via the cyclical application of a blood pressure cuff to a limb at above systolic pressure,confers systemic protection against ischaemia in spatially distinct vascular territories.The mechanisms underlying this have not been characterised fully but have been shown to involve neural,hormonal and systemic inflammatory signalling cascades.Preclinical and early clinical studies have been promising and suggest beneficial effects of RIC in acute ischaemic stroke,symptomatic intracranial stenosis and vascular cognitive impairment.Through systematic searches of several clinical trials databases we identified 48 active clinical trials of RIC in ischaemic stroke,intracerebral haemorrhage and subarachnoid haemorrhage.We summarise the different RIC protocols and outcome measures studied in ongoing clinical trials and highlight which studies are most likely to elucidate the underlying biological mechanisms of RIC and characterise its efficacy in the near future.We discuss the uncertainties of RIC including the optimal frequency and duration of therapy,target patient groups,cost-effectiveness,the confounding impact of medications and the absence of a clinically meaningful biomarker of the conditioning response.With several large clinical trials of RIC expected to report their outcomes within the next 2 years,this review aims to highlight the most important studies and unanswered questions that will need to be addressed before this potentially widely accessible and low-cost intervention can be used in clinical practice.

关键词： Remote directions founding

A low-pass filter of 300 Hz improved the detection of pacemaker spike on Remote and bedside electrocardiogram

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Chinese Medical Journal 2019年第5期132卷 534-541页

作者： Jian Sun Qiu-Feng Lu Yan Zhao Peng-Pai Zhang Jun Wang Qun-Shan Wang Xiao-Hong Liu Yi-Gang Li Department of Cardiology Xinhua Hospital Shanghai Jiao Tong University School of Medicine Shanghai 200092 China

Background: The current upper-frequency cutoff of 150Hz sometimes causes loss of pacemaker spike and misdiagnosis, hypothesized that low-pass filter (LPF) other than 150Hz could improve the detection of pacemaker spike. This study aimed to examine the effect of different LPF on pacemaker spike detection in Remote and bedside electrocardiogram (ECG). Methods: Patients with permanent pacemaker implantation were included during routine follow-up. Standard 12-lead ECGs at 6 different upper-frequency cutoff (40,100,150,200, 300, and 400 Hz) were collected. All ECGs were then transmitted to the Remote clinic center. Ventricular and atrial pacing were analyzed by 2 independent medical practitioners. Results: A total of 88 patients5 ECGs were analyzed (mean age 73.8±10.2 years and 85 with dual-chamber pacemakers). About 75.3%(64/85) of patients were diagnosed as atrial pacing by pacemaker programming. Among 6 different upper-frequency cutoff, the 300 Hz turned out to perform best in detecting atrial-paced spike (area under the curve [AUC]=0.73, 95% confidence interval [CI]:0.61-0.84 vs.0.56, 95% CI: 0.61-0.84 at 150 Hz;P=0.002) on bedside ECGs. Using programming as the golden standard, the 300 Hz LPF has a sensitivity of 59.4%, specificity of 85.7%, positive predictive value of 92.7% and negative predictive value of 40.9% on bedside ECGs. As for the ventricular pacing, the 300Hz LPF also had a higher accuracy (AUC=0.93;95% CI = 0.84-1.00) than that at 150Hz (AUC = 0.86;95% CI:0.77-0.94;PRemote ECGs were similar with bedside ECGs. Conclusions: A filter of 300 Hz cutoff may be recommended for ECG spike detection. With the recommended parameter, Remote ECG can perform as well as bedside ECG.

关键词： Digital electrocardiogram Pacemaker spike Upper-frequency cutoff Remote electrocardiogram

Advances in urban information extraction from high-resolution Remote sensing imagery

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Science China Earth Sciences 2020年第4期63卷 463-475页

作者： Jianya GONG Chun LIU Xin HUANG School of Remote Sensing and Information Engineering Wuhan UniversityWuhan 430079China State Key Laboratory of Information Engineering in Surveying Mapping and Remote SensingWuhan UniversityWuhan 430079China

The study of urban area is one of the hottest research topics in the field of Remote sensing. With the accumulation of high-resolution(HR) Remote sensing data and emerging of new satellite sensors, HR observation of urban areas has become increasingly possible, which provides us with more elaborate urban information. However, the strong heterogeneity in the spectral and spatial domain of HR imagery brings great challenges to urban Remote sensing. In recent years, numerous approaches were proposed to deal with HR image interpretation over complex urban scenes, including a series of features from low level to high level, as well as state-of-the-art methods depicting not only the urban extent, but also the intra-urban variations. In this paper, we aim to summarize the major advances in HR urban Remote sensing from the aspects of feature representation and information extraction. Moreover, the future trends are discussed from the perspectives of methodology, urban structure and pattern characterization, big data challenge, and global mapping.

关键词： High-resolution Urban Remote sensing Feature extraction Land use/land cover classification Change detection

Gottfried Konecny:our best friend in photogrammetry and Remote sensing of China

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Geo-Spatial Information Science 2021年第1期24卷 5-7,I0002页

作者： Deren Li Yixuan Zhu Lite Shi State Key Laboratory of Information Engineering in Surveying Mapping and Remote SensingWuhan UniversityWuhanChina

Preface Lebenslauf Prof.Dr.-Ing.mult Gottfried Konecny is one of the most respected names in photogrammetry.He is an Honorary Member of International Society for Photogrammetry and Remote Sensing(ISPRS),Honorary Profe... 详细信息

关键词： gramme ISPRS Remote

Digital Watermarking Secure Scheme for Remote Sensing Image Protection

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China Communications 2020年第4期17卷 88-98页

作者： Guanghui Yuan Qi Hao Space star technology co. LTDBeijing 100086China

As a means of copyright protection for multimedia data, digital watermarking technology has attracted more and more attention in various research fields. Researchers have begun to explore the feasibility of applying it to Remote sensing data recently. Because of the particularity of Remote sensing image, higher requirements are put forward for its security and management, especially for the copyright protection, illegal use and authenticity identification of Remote sensing image data. Therefore, this paper proposes to use image watermarking technology to achieve comprehensive security protection of Remote sensing image data, while the use of cryptography technology increases the applicability and security of watermarking technology. The experimental results show that the scheme of Remote sensing image digital watermarking technology has good performance in the imperceptibility and robustness of watermarking.

关键词： data security watermark Remote sensing image protection

Using multi-satellite microwave Remote sensing observations for retrieval of daily surface soil moisture across China

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Water Science and Engineering 2019年第2期12卷 85-97页

作者： Ke Zhang Li-jun Chao Qing-qing Wang Ying-chun Huang Rong-hua Liu Yang Hong Yong Tu Wei Qu Jin-yin Ye State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai UniversityNanjing 210098China College of Hydrology and Water Resources Hohai UniversityNanjing 210098China China Institute of Water Resources and Hydropower Research Beijing 100038China Research Center on Flood&Drought Disaster Reduction of the Ministry of Water Resources Beijing 100038China School of Civil Engineering Tsinghua UniversityBeijing 100084China Anhui Branch of China Meteorological Administration Training Centre Hefei 230031China

The objective of this study was to retrieve daily composite soil moisture by jointly using brightness temperature observations from multiple operating satellites for near real-time application with better coverage and higher accuracy.Our approach was to first apply the single-channel brightness radiometric algorithm to estimate soil moisture from the respective brightness temperature observations of the SMAP,SMOS,AMSR2,FY3B,and FY3C satellites on the same day and then produce a daily composite dataset by averaging the individual satellite-retrieved soil moisture.We further evaluated our product,the official soil moisture products of the five satellites,and the ensemble mean (i.e.,arithmetic mean) of the five official satellite soil moisture products against ground observations from two networks in Central Tibet and Anhui Province,China.The results show that our product outperforms the individual released products of the five satellites and their ensemble means in the two validation areas.The root mean square error (RMSE ) values of our product were 0.06 and 0.09 m3/m3 in Central Tibet and Anhui Province,respectively.Relative to the ensemble mean of the five satellite products,our product improves the accuracy by 9.1% and 57.7% in Central Tibet and Anhui Province,respectively.This demonstrates that jointly using brightness temperature observations from multiple satellites to retrieve soil moisture not only improves the spatial coverage of daily observations but also produces better daily composite products.

关键词： Soil moisture retrieval Passive microwave Remote sensing Multiple satellites Surface hydrology SMAP SMOS AMSR2 FY3B FY3C

Effective distributed convolutional neural network architecture for Remote sensing images target classification with a pre-training approach

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Journal of Systems Engineering and Electronics 2019年第2期30卷 238-244页

作者： LI Binquan HU Xiaohui School of Automation Science and Electrical Engineering Beihang University Institute of Software Chinese Academy of Sciences

How to recognize targets with similar appearances from Remote sensing images(RSIs) effectively and efficiently has become a big challenge. Recently, convolutional neural network(CNN) is preferred in the target classification due to the powerful feature representation ability and better performance. However,the training and testing of CNN mainly rely on single machine.Single machine has its natural limitation and bottleneck in processing RSIs due to limited hardware resources and huge time consuming. Besides, overfitting is a challenge for the CNN model due to the unbalance between RSIs data and the model structure.When a model is complex or the training data is relatively small,overfitting occurs and leads to a poor predictive performance. To address these problems, a distributed CNN architecture for RSIs target classification is proposed, which dramatically increases the training speed of CNN and system scalability. It improves the storage ability and processing efficiency of RSIs. Furthermore,Bayesian regularization approach is utilized in order to initialize the weights of the CNN extractor, which increases the robustness and flexibility of the CNN model. It helps prevent the overfitting and avoid the local optima caused by limited RSI training images or the inappropriate CNN structure. In addition, considering the efficiency of the Na¨?ve Bayes classifier, a distributed Na¨?ve Bayes classifier is designed to reduce the training cost. Compared with other algorithms, the proposed system and method perform the best and increase the recognition accuracy. The results show that the distributed system framework and the proposed algorithms are suitable for RSIs target classification tasks.

关键词： convolutional neural network (CNN) distributed architecture Remote sensing images (RSIs) target classification pre-training