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Missing Value Imputation for Radar-Derived Time-Series Tracks of Aerial Targets Based on Improved Self-Attention-Based Network

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Computers, Materials & Continua 2024年第3期78卷 3349-3376页

作者： Zihao Song Yan Zhou Wei Cheng Futai Liang chenhao zhang Department of Early Warning Intelligence Early Warning AcademyWuhan430019China

The frequent missing values in radar-derived time-series tracks of aerial targets(RTT-AT)lead to significant challenges in subsequent data-driven ***,the majority of imputation research focuses on random missing(RM)that differs significantly from common missing patterns of *** method for solving the RM may experience performance degradation or failure when applied to RTT-AT *** autoregressive deep learning methods are prone to error accumulation and long-term dependency *** this paper,a non-autoregressive imputation model that addresses the issue of missing value imputation for two common missing patterns in RTT-AT is *** model consists of two probabilistic sparse diagonal masking self-attention(PSDMSA)units and a weight fusion *** learns missing values by combining the representations outputted by the two units,aiming to minimize the difference between the missing values and their actual *** PSDMSA units effectively capture temporal dependencies and attribute correlations between time steps,improving imputation *** weight fusion unit automatically updates the weights of the output representations from the two units to obtain a more accurate final *** experimental results indicate that,despite varying missing rates in the two missing patterns,our model consistently outperforms other methods in imputation performance and exhibits a low frequency of deviations in estimates for specific missing *** to the state-of-the-art autoregressive deep learning imputation model Bidirectional Recurrent Imputation for Time Series(BRITS),our proposed model reduces mean absolute error(MAE)by 31%~50%.Additionally,the model attains a training speed that is 4 to 8 times faster when compared to both BRITS and a standard Transformer model when trained on the same ***,the findings from the ablation experiments demonstrate that the PSDMSA,the weight fusion unit,cascade network design

关键词： Missing value imputation time-series tracks probabilistic sparsity diagonal masking self-attention weight fusion

GCSS:a global collaborative scheduling strategy for wide-area high-performance computing

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Frontiers of Computer Science 2022年第5期16卷 1-15页

作者： Yao SONG Limin XIAO Liang WANG Guangjun QIN Bing WEI Baicheng YAN chenhao zhang State Key Laboratory of Software Development Environment Beihang UniversityBeijing 100191China School of Computer Science and Engineering Beihang UniversityBeijing 100191China Smart City College Beijing Union UniversityBeijing 100101China

Wide-area high-performance computing is widely used for large-scale parallel computing applications owing to its high computing and storage ***,the geographical distribution of computing and storage resources makes efficient task distribution and data placement more *** achieve a higher system performance,this study proposes a two-level global collaborative scheduling strategy for wide-area high-performance computing *** collaborative scheduling strategy integrates lightweight solution selection,redundant data placement and task stealing mechanisms,optimizing task distribution and data placement to achieve efficient computing in wide-area *** experimental results indicate that compared with the state-of-the-art collaborative scheduling algorithm HPS+,the proposed scheduling strategy reduces the makespan by 23.24%,improves computing and storage resource utilization by 8.28%and 21.73%respectively,and achieves similar global data migration costs.

关键词： high-performance computing scheduling strategy task scheduling data placement

Underground space use of urban built-up areas in the central city of Nanjing:Insight based on a dynamic population distribution

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Underground Space 2022年第5期7卷 748-766页

作者： Yulu Chen Zhilong Chen Dongjun Guo Ziwei Zhao Tong Lin chenhao zhang Army Engineering University of PLA NanjingJiangsu Province 210007PR China Nanjing Academy of Urban Planning and Design Co. LtdNanjingJiangsu Province 210000PR China

With the expansion of cities and the emergence of various urban problems,urban underground space has been developed as a *** China’s urban transition context,there is a need for the development of underground space in urban built-up *** this casestudy of the central city of Nanjing,we used spatial analysis and statistical methods to characterize the underground space use of urban built-up areas from a dynamic spatiotemporal *** first analyzed the relationship between the population distribution and the underground space use of the central city of Nanjing based on a Baidu heat map,which can reflect the real-time population distribution,and then,we explored the spatiotemporal characteristics and spatial structure of the underground space use in urban built-up *** analysis results provide a reference for planning to improve and optimize the layout of underground space in the central city of Nanjing and,more generally,for the stock-type planning of underground space in urban built-up areas.

关键词： Underground space use Dynamic population distribution Urban built-up area Spatiotemporal characteristics

Minimizing the cost of periodically replicated systems via model and quantitative analysis

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Frontiers of Computer Science 2024年第5期18卷 11-24页

作者： chenhao zhang Liang WANG Limin XIAO Shixuan JIANG Meng HAN Jinquan WANG Bing WEI Guangjun QIN State Key Laboratory of Software Development Environment Beihang UniversityBeijing 100191China School of Computer Science and Engineering Beihang UniversityBeijing 100191China School of Cyberspace Security Hainan UniversityHaikou 570228China Smart City College Beijing Union UniversityBeijing 100101China

Geographically replicating objects across multiple data centers improves the performance and reliability of cloud storage *** consistent replicas comes with high synchronization costs,as it faces more expensive WAN transport prices and increased *** replication is the widely used technique to reduce the synchronization *** replication strategies in existing cloud storage systems are too static to handle traffic changes,which indicates that they are inflexible in the face of unforeseen loads,resulting in additional synchronization *** propose quantitative analysis models to quantify consistency and synchronization cost for periodically replicated systems,and derive the optimal synchronization period to achieve the best tradeoff between consistency and synchronization *** on this,we propose a dynamic periodic synchronization method,Sync-Opt,which allows systems to set the optimal synchronization period according to the variable load in clouds to minimize the synchronization *** results demonstrate the effectiveness of our *** with the policies widely used in modern cloud storage systems,the Sync-Opt strategy significantly reduces the synchronization cost.

关键词： periodic replication consistency maintenance synchronization cost synchronization strategy

Trip Purposes of Automobile Users Inference Using Multi-day Traffic Monitoring Data

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Journal of Harbin Institute of Technology(New Series) 2023年第5期30卷 1-11页

作者： Wen Zheng Wenquan Li Qian Chen Yan Zheng chenhao zhang School of Transportation Southeast UniversityNanjing211189China

Determining trip purpose is an important link to explore travel rules. In this paper,we takea utomobile users in urban areas as the research object,combine unsupervised learning and supervised learningm ethods to analyze their travel characteristics,and focus on the classification and prediction of automobileu sers’trip purposes. However,previous studies on trip purposes mainly focused on questionnaires and GPSd ata,which cannot well reflect the characteristics of automobile travel. In order to avoid the multi-dayb ehavior variability and unobservable heterogeneity of individual characteristics ignored in traditional traffic questionnaires,traffic monitoring data from the Northern District of Qingdao are used,and the K-meansc lustering method is applied to estimate the trip purposes of automobile users. Then,Adaptive Boosting(AdaBoost)and Random Forest(RF)methods are used to classify and predict trip purposes. Finally,ther esult shows:(1)the purpose of automobile users can be mainly divided into four clusters,which includeC ommuting trips,Flexible life demand travel in daytime,Evening entertainment and leisure shopping,andT axi-based trips for the first three types of purposes,respectively;(2)the Random Forest method performss ignificantly better than AdaBoost in trip purpose prediction for higher accuracy;(3)the average predictiona ccuracy of Random Forest under hyper-parameters optimization reaches96.25%,which proves the feasibilitya nd rationality of the above clustering results.

关键词： trip purpose automobile users traffic monitoring data K-means clustering AdaBoost random forest

Dissecting anxiety-related QTLs in mice by univariate and multivariate mapping

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Chinese Science Bulletin 2012年第21期57卷 2727-2732页

作者： ZHU ZhiHong zhang chenhao WANG XuSheng COOK Melloni N WILLIAMS Robert LU Lu ZHU Jun ZJU-IBM Biocomputation Laboratory College of Agriculture and BiotechnologyZhejiang UniversityHangzhou 310058China Jiangsu Key Laboratory of Neuroregeneration Nantong UniversityNantong 226001China Department of Anatomy and Neurobiology University of Tennessee Healthy Science CenterMemphisTN 38163USA Department of Psychology University of MemphisMemphisTN 38152USA

To detect genes underlying anxiety-related traits in mice,we performed univariate and multivariate QTL mapping analyses of phenotypes obtained from 71 mice of the BXD recombinant inbred (RI) strains (n=528 mice) and their parental strains (C57BL/6J and DBA/2J).Separate and joint mapping analyses were carried out using a linkage map composed of 506 simple sequence repeats (SSRs).The main QTL effects,interactions between pairs of QTLs (epistasis),and their environmental interactions were *** results showed that anxiety-related traits were influenced by multiple QTLs (five main effect QTLs and three epistatic QTLs).Ten potential anxiety-related candidate genes within the QTL intervals on chromosomes 5,13 and 15 were *** of these genes have been reported previously to be associated with the anxiety *** on our results,it is suggested that the multivariate QTL mapping approach improves the statistical power for detecting QTL and the precision of parameter ***,multivariate mapping can also detect pleiotropic QTL effects.

关键词： QTL定位映射分析焦虑小鼠多变量单变量 QTL效应解剖

An epidermal electrode based triboelectric walking energy harvester for wearable wireless sensing applications

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Science China(Technological Sciences) 2024年第3期67卷 949-957页

作者： CHANG ShiYuan LIU FuHai CHEN JinKai XIA LianBin ZHOU Hao JIANG JingYang DONG Kang zhang chenhao WU Yun CHEN Jin XUAN Weipeng SUN LingLing JIN Hao DONG ShuRong LUO JiKui Ministry of Education Key Laboratory of RF Circuits and Systems Hangzhou Dianzi UniversityHangzhou 310018China Special Equipment College Hangzhou Vocational&Technical CollegeHangzhou 310018China College of Information Science and Electronic Engineering Zhejiang UniversityHangzhou 330027China ZJU-Hangzhou Global Scientific and Technological Innovation Center Zhejiang UniversityHangzhou 311200China

Harvesting bio-kinetic energy using a triboelectric nanogenerator(TENG) is one of the promising routes to solve the sustainable energy supply problem for wearable electronics. However, additional materials, complex fabricating processes or specific mechanical structures are needed for existing TENGs to harvest bio-kinetic energy. Besides, they need to be tightly attached to the human body, which may result in detachment and malfunction under tense human motion. Herein, an intrinsic epidermal electrode-based TENG(E-TENG) is proposed to harvest human walking energy. The wearing shoes and ground are used as tribo-materials, and the human epidermis is used as the back electrode of the E-TENG. Compared with the traditional TENGs,the E-TENG does not need any additional tribo-materials and complex mechanical structures. Under optimal conditions, the voltage output of E-TENG can reach 914 V. E-TENG has been used as a self-powered warning sensor and pedometer sensor for demonstration. Furthermore, E-TENG based self-powered wireless sensor system has been developed using a newly designed micro energy electronic switch(MEES). Ambient ultraviolet intensity, temperature and humidity information can be monitored and then transmitted to mobile phone every 3.5 min, demonstrating great potential for widespread wearable applications.

关键词： triboelectric nanogenerator wearable wireless sensing self-powered

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二维PT对称晶格势中的多极光孤子

光学学报 2016年第2期36卷 155-162页

作者：章臣浩徐四六湖北科技学院电子与信息工程学院湖北咸宁437100

基于改进的平方算符方法和傅里叶配点法,研究了二维宇称-时间(PT)对称的三角-高斯晶格势中二极、三极和四极光孤子的传输特性。结果表明:三极孤子的光场分布随参数变化而变化,不存在稳定的三极孤子;二极、四极孤子的功率随传播常数的增... 详细信息

基于改进的平方算符方法和傅里叶配点法,研究了二维宇称-时间(PT)对称的三角-高斯晶格势中二极、三极和四极光孤子的传输特性。结果表明:三极孤子的光场分布随参数变化而变化,不存在稳定的三极孤子;二极、四极孤子的功率随传播常数的增大而增大,随调制深度的增大而减小;孤子稳定性决定于晶格的调制深度和传播系数,对于给定的调制深度,孤子存在一个稳定性范围;当调制深度增加时,二极孤子的稳定性范围先减小后增大,而四极孤子则先呈波浪式增大后减小。

关键词：非线性光学多极光孤子改进的平方算符法宇称-时间对称晶格势

The influence of ^(18)F-fluorodeoxyglucose positron emission tomography/computed tomography on the N-and M-staging and subsequent clinical management of intrahepatic cholangiocarcinoma

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Hepatobiliary Surgery and Nutrition 2022年第5期11卷 684-695,I0002-I0007页

作者： Youpei Lin Huanhuan Chong Guohe Song chenhao zhang Liangqing Dong Ling Aye Fei Liang Shuaixi Yang Mengsu Zeng Guangyu Ding Shu zhang Jieyi Shi Aiwu Ke Xiaoying Wang Jian Zhou Jia Fan Qiang Gao Department of Liver Surgery and Transplantation Liver Cancer InstituteZhongshan Hospitaland Key Laboratory of Carcinogenesis and Cancer Invasion(Ministry of Education)Fudan UniversityShanghaiChina Department of Radiology Zhongshan HospitalFudan UniversityShanghaiChina Department of Biostatistics Zhongshan HospitalFudan UniversityShanghaiChina Key Laboratory of Medical Epigenetics and Metabolism Institutes of Biomedical SciencesFudan UniversityShanghaiChina

Background:Intrahepatic cholangiocarcinoma(ICC)is a highly metastatic cancer.^(18)F-fluorodeoxyglucose positron emission tomography/computed tomography(^(18)F-FDG PET/CT)enables sensitive tumor and metastasis *** aim is to evaluate the influence of pre-treatment PET/CT on the N-and M-staging and subsequent clinical management in ICC ***:Between August 2010 and August 2018,660 consecutive ICC patients,without prior anti-tumor treatments nor other malignancies,were *** diagnostic performance of PET/CT on the N-and M-staging was compared with conventional imaging,and the preoperative staging accuracy and treatment re-allocation by PET/CT were retrospectively *** difference was compared between patients receiving PET/CT or not after propensity score ***:Patients were divided into group A(n=291)and group B(n=369)according to whether PET/CT was *** 291 patients with both PET/CT and conventional imaging for staging in group A,PET/CT showed significantly higher sensitivity(83.0%vs.70.5%,P=0.001),specificity(88.3%vs.74.9%,P<0.001)and accuracy(86.3%vs.73.2%,P<0.001)than conventional imaging in diagnosing regional lymph node metastasis,as well as higher sensitivity(87.8%vs.67.6%,P<0.001)and accuracy(93.5%vs.89.3%,P=0.023)in diagnosing distant ***,PET/CT improved the accuracy of preoperative staging from 60.1%to 71.8%(P<0.001),and modified clinical treatment strategy in 5.8%(17/291)of ICC patients,with unique roles in different tumor-node-metastasis(TNM)*** tumor-to-non-tumor ratio(TNR)predicted poor overall survival[hazard ratio(HR)=2.17;95%confidence interval(CI):1.49-3.15;P<0.001].Furthermore,patients performing PET/CT had longer overall survival compared with those without PET/CT(HR=0.74;95%CI:0.58-0.93;P=0.011)after propensity score ***:PET/CT was valuable for diagnosing regional lymph node metastasis and distant metastasis in ICC patients,and facilitated accura

关键词： Intrahepatic cholangiocarcinoma(ICC) staging positron emission tomography/computed tomography(PET/CT) clinical management