检索结果-南通市图书馆

A time and charge measurement board for muon tomography of high-Z materials

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2017年第3期28卷 104-108页

作者： Shi-tao xiang Hao Liang State Key Laboratory of Particle Detection and Electronics University of Science and Technology of ChinaHefei 230026 China Department of Modern Physics University of Science and Technology of China Hefei 230026 China

In this paper, a versatile time and charge measurement(MQT) board for muon tomography is described in detail. For time measurement, the general-purpose timeto-digital converter(TDC) chip TDC-GP2 is employed,while for charge measurement, digitization plus numerical integration in field programmable gate array is *** tests demonstrate that the total 32 channels of two MQT boards have a time resolution of superior than100 ps, with excellent linearity for time and charge measurement.

关键词： Time and charge measurement Generalpurpose time-to-digital converter (TDC-GP2) Muon tomography

Timed RR-interval Scatter Plots and Reverse Technology

在线全文

学校读者我要写书评

暂无评论

Current Medical Science 2020年第6期40卷 1191-1202页

作者： Jin-tao xiang Department of Cardiology Remin HospitalWuhan UniversityWuhan 430060China

Lorenz-RR scatter plot has an obvious shortcoming in that it does not indicate the time when the scatter point *** the Lorenz RR scatter plot,one cannot know the time during which the cardiac rhythms take *** occurrence of cardiac rhythms is time-related,time should be introduced to such *** this study,time was used as abscissa and RR interval(the time interval between the previous RR wave and the R wave)as the ordinate and time was compressed into a visually observable length,and thereby a timed RR-interval scatter plot,or t-RR scatter plot,for short,was *** t-RR scatter plot,the patterns were band-shaped or were of linear *** the t-RR plot,the sinus rhythm presented bands of various widths,with the spiculate or burred upper and lower boundaries,having diurnal *** beats showed separate layers(“stratification”),the layer number corresponding the number of *** simple premature beats,the layers were clearly *** parasystole rhythm,the upper and lower bands or layers might become *** arial premature beats,the space or distance between layers *** premature beats presented equal space or distance between *** tachycardia,the lower layer became a“solid”*** atrial fibration,the“stratification”disappeared,presenting thicker or widened layers or bands,with neat lower *** atrial flutter,the layers went parallel,with the layers being evenly separated or some distances being exact multiples of *** second degree atrioventricular block displayed two layers,the lower and upper bands being equally away from the X-axis,presenting a straight line(pacing at a fixed rate)or a thicker or wider bands,with a neat upper boundary(the lowest pacing rate).When the scatter plot presented uncharacteristic patterns or had some scattered points,which rendered diagnosis difficult,a reverse technology could be ***,upon selection of scattered points,they were subje

关键词： electrocardiogram dynamic electrocardiogram review timed RR-interval scatter plot methodology

Boundedness of multilinear operators on generalized Morrey spaces

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 2014年第2期29卷 127-138页

作者： YU Xiao tao xiang-xing Department of Mathematics Shangrao Normal University Department of Mathematics Zhejiang University of Science and Technology

In this paper, the authors prove the boundedness of the multilinear maximal func- tions, multilinear singular integrals and multilinear Riesz potential on the product generalized Rn Rn Morrey spaces Mp1,ωw1 （Rn）... 详细信息

关键词： multilinear singular integral multilinear Riesz potential generalized Morrey space multilinearmaximal function.

Modeling epidemic spread in transportation networks:A review

在线全文

学校读者我要写书评

暂无评论

Journal of Traffic and Transportation Engineering(English Edition) 2021年第2期8卷 139-152页

作者： Jian Li tao xiang Linghui He Key Laboratory of Road and Traffic Engineering of Ministry of Education Tongji UniversityShanghai 201804China College of Transportation Engineering Tongji UniversityShanghai 201804China Institute for Urban Risk Management Tongji UniversityShanghai 201804China

The emergence of novel infectious diseases has become a serious global *** transportation networks lead to rapid mobilization in the context of globalization,which is an important factor underlying the rapid spread of infectious *** systems can cause the transmission of viruses during the epidemic period,but they also support the reopening of economies after the *** the mechanism of the impact of mobility on the spread of infectious diseases is thus important,as is establishing the risk model of the spread of infectious diseases in transportation *** this study,the basic structure and application of various epidemic spread models are reviewed,including mathematical models,statistical models,network-based models,and simulation *** advantages and limitations of model applications within transportation systems are analyzed,including dynamic characteristics of epidemic transmission and decision supports for management and ***,research trends and prospects are *** is suggested that there is a need for more in-depth research to examine the mutual feedback mechanism of epidemics and individual behavior,as well as the proposal and evaluation of intervention *** findings in this study can help evaluate disease intervention strategies,provide decision supports for transport policy during the epidemic period,and ameliorate the deficiencies of the existing system.

关键词： Traffic engineering Infectious disease control Epidemic spread models Human mobility Transportation networks

同方期刊数据库

3-restricted connectivity of graphs with given girth

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 2008年第3期23卷 351-358页

作者： GUO Li-tao MENG Ji-xiang College of Math. and Sys. Sci. Xinjiang Univ. Xinjiang 830046 China

Let G = （V, E） be a connected graph. X belong to V（G） is a vertex set. X is a 3-restricted cut of G, if G- X is not connected and every component of G- X has at least three vertices. The 3-restricted connectivity κ3（G）（in short κ3） of G is the cardinality of a minimum 3-restricted cut of G. X is called κ3-cut, if ｜X｜ = κ3. A graph G is κ3-connected, if a 3-restricted cut exists. Let G be a graph girth g ≥ 4, κ3（G） is min{d（x）＋ d（y）＋ d（z） - 4 ： xyz is a 2-path of G}. It will be shown that κ3（G） = ξ3（G） under the condition of girth.

关键词： 3-restricted cut 3-restricted connectivity girth

Android Malware Detection Method Based on Permission Complement and API Calls

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2022年第4期31卷 773-785页

作者： YANG Jiyun TANG Jiang YAN Ran xiang tao College of Computer Science Chongqing University

The dynamic code loading mechanism of the Android system allows an application to load executable files externally at runtime. This mechanism makes the development of applications more convenient, but it also brings security issues. Applications that hide malicious behavior in the external file by dynamic code loading are becoming a new challenge for Android malware detection. To overcome this challenge, based on dynamic code loading mechanisms, three types of threat models,i.e. Model I, Model II, and Model III are defined. For the Model I type malware, its malicious behavior occurs in Dex Code, so the application programming interface(API)classes were used to characterize the behavior of the DexCode file. For the Model II type and Model III type malwares whose malicious behaviors occur in an external file,the permission complement is defined to characterize the behaviors of the external file. Based on permission complement and API calls, an Android malicious application detection method is proposed, of which feature sets are constructed by improving a feature selection method. Five datasets containing 15,581 samples are used to evaluate the performance of the proposed method. The experimental results show that our detection method achieves accuracy of 99.885% on general dataset, and performes the best on all evaluation metrics on all datasets in all comparison methods.

关键词： Android malicious application detection method threat models API calls Data security malicious behavior Android malware detection method Operating systems DexCode file executable files application programming interface classes Android (operating system) Ubiquitous and pervasive computing permission complement invasive software external file dynamic code loading mechanism application program interfaces feature selection method feature selection

Practical cloud storage auditing using serverless computing

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第3期67卷 33-47页

作者： Fei CHEN Jianquan CAI tao xiang Xiaofeng LIAO College of Computer Science and Software Engineering Shenzhen University College of Computer Science Chongqing University

Cloud storage auditing research is dedicated to solving the data integrity problem of outsourced storage on the cloud. In recent years, researchers have proposed various cloud storage auditing schemes using different techniques. While these studies are elegant in theory, they assume an ideal cloud storage model;that is, they assume that the cloud provides the storage and compute interfaces as required by the proposed schemes. However, this does not hold for mainstream cloud storage systems because these systems only provide read and write interfaces but not the compute interface. To bridge this gap, this work proposes a serverless computing-based cloud storage auditing system for existing mainstream cloud object storage. The proposed system leverages existing cloud storage auditing schemes as a basic building block and makes two adaptations. One is that we use the read interface of cloud object storage to support block data requests in a traditional cloud storage auditing scheme. Another is that we employ the serverless computing paradigm to support block data computation as traditionally required. Leveraging the characteristics of serverless computing, the proposed system realizes economical, pay-as-you-go cloud storage auditing. The proposed system also supports mainstream cloud storage upper layer applications(e.g., file preview) by not modifying the data formats when embedding authentication tags for later auditing. We prototyped and open-sourced the proposed system to a mainstream cloud service, i.e., Tencent Cloud. Experimental results show that the proposed system is efficient and promising for practical use. For 40 GB of data, auditing takes approximately 98 s using serverless computation. The economic cost is 120.48 CNY per year, of which serverless computing only accounts for 46%. In contrast, no existing studies reported cloud storage auditing results for real-world cloud services.

关键词： cloud storage auditing serverless computing object storage usability

Boundedness for multilinear fractional integral operators on Herz type spaces

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 2008年第4期23卷 437-446页

作者： SHI Yan-long tao xiang-xing Dept. of Math. Faculty of Science Ningbo Univ. Ningbo 315211 China

In this paper the boundedness for the multilinear fractional integral operator Iα^（m） on the product of Herz spaces and Herz-Morrey spaces are founded, which improves the Hardy- Littlewood-Sobolev inequality for classical fractional integral Iα. The method given in the note is useful for more general multilinear integral operators.

关键词： multilinear fractional integral Herz space homogeneous Herz-Morrey space product space

Inter-valley spiral order in the Mott insulating state of a heterostructure of trilayer graphene-boron nitride

在线全文

学校读者我要写书评

暂无评论

Science Bulletin 2018年第17期63卷 1087-1091页

作者： Guo-Yi Zhu tao xiang Guang-Ming Zhang State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics. Tsinghua University Beijing 100084 China Institute of Physics. Chinese Academy of Sciences Beijing 100190 China Collaborative Innovation Center of Quantum Matter Beijing 100084 China

Recent experiment has shown that the ABC-stacked trilayer graphene-boron nitride Moire super-lattice at half-filling is a Mort insulator. Based on symmetry analysis and effective band structure calculation, we propose a valley-contrasting chiral tight-binding model with local Coulomb interaction to describe this Moire super-lattice system. By matching the positions of van Hove points in the low-energy effective bands, the valley-contrasting staggered flux per triangle is determined around π/2. When the valence band is half-filled, the Fermi surfaces are found to be perfectly nested between the two valleys. Such an effect can induce an inter-valley spiral order with a gap in the charge excitations, indicating that the Mott insulating behavior observed in the trilayer graphene-boron nitride Moire super-lattice results predominantly from the inter-valley scattering,

关键词： Moire superlattice Mott phase Valley Fermi surface nesting Multilayer graphene