期刊文献+
共找到243篇文章
< 1 2 13 >
每页显示 20 50 100
Ensuring Secure Platooning of Constrained Intelligent and Connected Vehicles Against Byzantine Attacks:A Distributed MPC Framework
1
作者 Henglai Wei Hui Zhang +1 位作者 Kamal AI-Haddad Yang Shi 《Engineering》 SCIE EI CAS CSCD 2024年第2期35-46,共12页
This study investigates resilient platoon control for constrained intelligent and connected vehicles(ICVs)against F-local Byzantine attacks.We introduce a resilient distributed model-predictive platooning control fram... This study investigates resilient platoon control for constrained intelligent and connected vehicles(ICVs)against F-local Byzantine attacks.We introduce a resilient distributed model-predictive platooning control framework for such ICVs.This framework seamlessly integrates the predesigned optimal control with distributed model predictive control(DMPC)optimization and introduces a unique distributed attack detector to ensure the reliability of the transmitted information among vehicles.Notably,our strategy uses previously broadcasted information and a specialized convex set,termed the“resilience set”,to identify unreliable data.This approach significantly eases graph robustness prerequisites,requiring only an(F+1)-robust graph,in contrast to the established mean sequence reduced algorithms,which require a minimum(2F+1)-robust graph.Additionally,we introduce a verification algorithm to restore trust in vehicles under minor attacks,further reducing communication network robustness.Our analysis demonstrates the recursive feasibility of the DMPC optimization.Furthermore,the proposed method achieves exceptional control performance by minimizing the discrepancies between the DMPC control inputs and predesigned platoon control inputs,while ensuring constraint compliance and cybersecurity.Simulation results verify the effectiveness of our theoretical findings. 展开更多
关键词 Model predictive control Resilient control Platoon control Intelligent and connected vehicle Byzantine attacks
下载PDF
Posture Detection of Heart Disease Using Multi-Head Attention Vision Hybrid(MHAVH)Model
2
作者 Hina Naz Zuping Zhang +3 位作者 Mohammed Al-Habib Fuad A.Awwad Emad A.A.Ismail Zaid Ali Khan 《Computers, Materials & Continua》 SCIE EI 2024年第5期2673-2696,共24页
Cardiovascular disease is the leading cause of death globally.This disease causes loss of heart muscles and is also responsible for the death of heart cells,sometimes damaging their functionality.A person’s life may ... Cardiovascular disease is the leading cause of death globally.This disease causes loss of heart muscles and is also responsible for the death of heart cells,sometimes damaging their functionality.A person’s life may depend on receiving timely assistance as soon as possible.Thus,minimizing the death ratio can be achieved by early detection of heart attack(HA)symptoms.In the United States alone,an estimated 610,000 people die fromheart attacks each year,accounting for one in every four fatalities.However,by identifying and reporting heart attack symptoms early on,it is possible to reduce damage and save many lives significantly.Our objective is to devise an algorithm aimed at helping individuals,particularly elderly individuals living independently,to safeguard their lives.To address these challenges,we employ deep learning techniques.We have utilized a vision transformer(ViT)to address this problem.However,it has a significant overhead cost due to its memory consumption and computational complexity because of scaling dot-product attention.Also,since transformer performance typically relies on large-scale or adequate data,adapting ViT for smaller datasets is more challenging.In response,we propose a three-in-one steam model,theMulti-Head Attention Vision Hybrid(MHAVH).Thismodel integrates a real-time posture recognition framework to identify chest pain postures indicative of heart attacks using transfer learning techniques,such as ResNet-50 and VGG-16,renowned for their robust feature extraction capabilities.By incorporatingmultiple heads into the vision transformer to generate additional metrics and enhance heart-detection capabilities,we leverage a 2019 posture-based dataset comprising RGB images,a novel creation by the author that marks the first dataset tailored for posture-based heart attack detection.Given the limited online data availability,we segmented this dataset into gender categories(male and female)and conducted testing on both segmented and original datasets.The training accuracy of our model reached an impressive 99.77%.Upon testing,the accuracy for male and female datasets was recorded at 92.87%and 75.47%,respectively.The combined dataset accuracy is 93.96%,showcasing a commendable performance overall.Our proposed approach demonstrates versatility in accommodating small and large datasets,offering promising prospects for real-world applications. 展开更多
关键词 Image analysis posture of heart attack(PHA)detection hybrid features VGG-16 ResNet-50 vision transformer advance multi-head attention layer
下载PDF
Integral Event-Triggered Attack-Resilient Control of Aircraft-on-Ground Synergistic Turning System With Uncertain Tire Cornering Stiffness 被引量:2
3
作者 Chenglong Du Fanbiao Li +2 位作者 Yang Shi Chunhua Yang Weihua Gui 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2023年第5期1276-1287,共12页
This article proposes an integral-based event-triggered attack-resilient control method for the aircraft-on-ground(AoG) synergistic turning system with uncertain tire cornering stiffness under stochastic deception att... This article proposes an integral-based event-triggered attack-resilient control method for the aircraft-on-ground(AoG) synergistic turning system with uncertain tire cornering stiffness under stochastic deception attacks. First, a novel AoG synergistic turning model is established with synergistic reverse steering of the front and main wheels to decrease the steering angle of the AoG fuselage, thus reducing the steady-state error when it follows a path with some large curvature. Considering that the tire cornering stiffness of the front and main wheels vary during steering, a dynamical observer is designed to adaptively identify them and estimate the system state at the same time.Then, an integral-based event-triggered mechanism(I-ETM) is synthesized to reduce the transmission frequency at the observerto-controller end, where stochastic deception attacks may occur at any time with a stochastic probability. Moreover, an attackresilient controller is designed to guarantee that the closed-loop system is robust L2-stable under stochastic attacks and external disturbances. A co-design method is provided to get feasible solutions for the observer, controller, and I-ETM simultaneously. An optimization program is further presented to make a tradeoff between the robustness of the control scheme and the saving of communication resources. Finally, the low-and high-probability stochastic deception attacks are considered in the simulations. The results have illustrated that the AoG synergistic turning system with the proposed control method follows a path with some large curvature well under stochastic deception attacks. Furthermore,compared with the static event-triggered mechanisms, the proposed I-ETM has demonstrated its superiority in saving communication resources. 展开更多
关键词 Adaptive observer aircraft-on-ground(AoG)synergistic turning attack-resilient controller integral-based event-triggered mechanism L_2-stability
下载PDF
BANACH SPACES AND INEQUALITIES ASSOCIATED WITH NEW GENERALIZATION OF CESàRO MATRIX
4
作者 Feyzi BASAR Hadi ROOPAEI 《Acta Mathematica Scientia》 SCIE CSCD 2023年第4期1518-1536,共19页
Let the triangle matrix A^(ru)be a generalization of the Cesàro matrix and U∈{c_(0),c,l_(∞)}.In this study,we essentially deal with the space U(A^(ru))defined by the domain of A^(ru)in the space U and give the ... Let the triangle matrix A^(ru)be a generalization of the Cesàro matrix and U∈{c_(0),c,l_(∞)}.In this study,we essentially deal with the space U(A^(ru))defined by the domain of A^(ru)in the space U and give the bases,and determine the Kothe-Toeplitz,generalized K?theToeplitz and bounded-duals of the space U(A^(ru)).We characterize the classes(l_(∞)(A^(ru)):l_(∞)),(l_(∞)(A^(ru)):c),(c(A^(ru)):c),and(U:V(A^(ru)))of infinite matrices,where V denotes any given sequence space.Additionally,we also present a Steinhaus type theorem.As an another result of this study,we investigate the l_(p)-norm of the matrix A^(ru)and as a result obtaining a generalized version of Hardy's inequality,and some inclusion relations.Moreover,we compute the norm of well-known operators on the matrix domain l_(p)(A^(ru)). 展开更多
关键词 matrix domain normed sequence space duals and matrix transformations
下载PDF
Error reachable set based stabilization of switched linear systems with bounded peak disturbances
5
作者 Xinxin Shang Songlin Zhuang +1 位作者 Tianyu Tan Yang Shi 《Journal of Automation and Intelligence》 2023年第2期87-98,共12页
This paper investigates the error reachable set based stabilization problem for a class of discrete-time switched linear systems with bounded peak disturbances under persistent dwell-time(PDT)constraint.A double-clock... This paper investigates the error reachable set based stabilization problem for a class of discrete-time switched linear systems with bounded peak disturbances under persistent dwell-time(PDT)constraint.A double-clockdependent control scheme is presented that can split the disturbed switched system into a nominal system and an error system,and assign to each system a controller scheduled by a clock.A necessary and sufficient convex stability criterion is presented for the nominal system,and is further extended to the stabilization controller design with a nominal clock.In the presence of bounded peak disturbances,another stabilization controller with an error clock is developed for the error system,with the purpose of‘‘minimizing’’the reachable set of the error system by the ellipsoidal techniques.It is demonstrated that the disturbed system is also globally exponentially stable in the sense of converging to an over approximation of the reachable set of the error system,i.e.,a union of a family of bounding ellipsoids,that can also be regarded as the cross section of a tube containing the trajectories of the disturbed system.Two numerical examples are provided to verify the effectiveness of the developed results. 展开更多
关键词 Bounded peak disturbances Persistent dwell-time Reachable set minimization Stability and stabilization Switched systems
下载PDF
Complexity of Injective Homomorphisms to Small Tournaments, and of Injective Oriented Colourings
6
作者 Russell J. Campbell Nancy E. Clarke Gary MacGillivray 《Open Journal of Discrete Mathematics》 2023年第1期1-15,共15页
Several possible definitions of local injectivity for a homomorphism of an oriented graph G to an oriented graph H are considered. In each case, we determine the complexity of deciding whether there exists such a homo... Several possible definitions of local injectivity for a homomorphism of an oriented graph G to an oriented graph H are considered. In each case, we determine the complexity of deciding whether there exists such a homomorphism when G is given and H is a fixed tournament on three or fewer vertices. Each possible definition leads to a locally-injective oriented colouring problem. A dichotomy theorem is proved in each case. 展开更多
关键词 Injective Graph Homomorphism Oriented Colouring COMPLEXITY
下载PDF
Effects of cumulative COVID-19 cases on mental health:Evidence from multi-country survey
7
作者 Shanaya Rathod Saseendran Pallikadavath +14 位作者 Elizabeth Graves Mohammad M Rahman Ashlea Brooks Pranay Rathod Rachna Bhargava Muhammad Irfan Reham Aly Haifa Mohammad Saleh Al Gahtani Zahwa Salam Steven Wai Ho Chau Theone S E Paterson Brianna Turner Viktoria Gorbunova Vitaly Klymchuk Peter Phiri 《World Journal of Psychiatry》 SCIE 2023年第7期461-477,共17页
BACKGROUND Depression and anxiety were both ranked among the top 25 leading causes of global burden of diseases in 2019 prior to the coronavirus disease 2019(COVID-19)pandemic.The pandemic affected,and in many cases t... BACKGROUND Depression and anxiety were both ranked among the top 25 leading causes of global burden of diseases in 2019 prior to the coronavirus disease 2019(COVID-19)pandemic.The pandemic affected,and in many cases threatened,the health and lives of millions of people across the globe and within the first year,global prevalence of anxiety and depression increased by 25%with the greatest influx in places highly affected by COVID-19.AIM To explore the psychological impact of the pandemic and resultant restrictions in different countries using an opportunistic sample and online questionnaire in different phases of the pandemic.METHODS A repeated,cross-sectional online international survey of adults,16 years and above,was carried out in 10 countries(United Kingdom,India,Canada,Bangladesh,Ukraine,Hong Kong,Pakistan,Egypt,Bahrain,Saudi Arabia).The online questionnaire was based on published approaches to understand the psychological impact of COVID-19 and the resultant restrictions.Five standardised measures were included to explore levels of depression[patient health questionnaire(PHQ-9)],anxiety[generalized anxiety disorder(GAD)assessment],impact of trauma[the impact of events scale-revised(IES-R)],loneliness(a brief loneliness scale),and social support(The Multidimensional Scale of Perceived Social support).RESULTS There were two rounds of the online survey in 10 countries with 42866 participants in Round 1 and 92260 in Round 2.The largest number of participants recruited from the United Kingdom(112985 overall).The majority of participants reported receiving no support from mental health services throughout the pandemic.This study found that the daily cumulative COVID-19 cases had a statistically significant effect on PHQ-9,GAD-7,and IES-R scores.These scores significantly increased in the second round of surveys with the ordinary least squares regression results with regression discontinuity design specification(to control lockdown effects)confirming these results.The study findings imply that participants’mental health worsened with high cumulative COVID-19 cases.CONCLUSION Whist we are still living through the impact of COVID-19,this paper focuses on its impact on mental health,discusses the possible consequences and future implications.This study revealed that daily cumulative COVID-19 cases have a significant impact on depression,anxiety,and trauma.Increasing cumulative cases influenced and impacted education,employment,socialization and finances,to name but a few.Building a database of global evidence will allow for future planning of pandemics,particularly the impact on mental health of populations considering the cultural differences. 展开更多
关键词 COVID-19 Mental health Global research International PANDEMIC Impact
下载PDF
Asynchronous Learning-Based Output Feedback Sliding Mode Control for Semi-Markov Jump Systems: A Descriptor Approach
8
作者 Zheng Wu Yiyun Zhao +3 位作者 Fanbiao Li Tao Yang Yang Shi Weihua Gui 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第6期1358-1369,共12页
This paper presents an asynchronous output-feed-back control strategy of semi-Markovian systems via sliding mode-based learning technique.Compared with most literature results that require exact prior knowledge of sys... This paper presents an asynchronous output-feed-back control strategy of semi-Markovian systems via sliding mode-based learning technique.Compared with most literature results that require exact prior knowledge of system state and mode information,an asynchronous output-feedback sliding sur-face is adopted in the case of incompletely available state and non-synchronization phenomenon.The holonomic dynamics of the sliding mode are characterized by a descriptor system in which the switching surface is regarded as the fast subsystem and the system dynamics are viewed as the slow subsystem.Based upon the co-occurrence of two subsystems,the sufficient stochastic admissibility criterion of the holonomic dynamics is derived by utilizing the characteristics of cumulative distribution functions.Furthermore,a recursive learning controller is formulated to guarantee the reachability of the sliding manifold and realize the chattering reduction of the asynchronous switching and sliding motion.Finally,the proposed theoretical method is substantia-ted through two numerical simulations with the practical contin-uous stirred tank reactor and F-404 aircraft engine model,respectively. 展开更多
关键词 Asynchronous switching learning-based control output feedback semi-Markovian jump systems sliding mode con-trol(SMC).
下载PDF
Physical Safety and Cyber Security Analysis of Multi-Agent Systems:A Survey of Recent Advances 被引量:18
9
作者 Dan Zhang Gang Feng +1 位作者 Yang Shi Dipti Srinivasan 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2021年第2期319-333,共15页
Multi-agent systems(MASs)are typically composed of multiple smart entities with independent sensing,communication,computing,and decision-making capabilities.Nowadays,MASs have a wide range of applications in smart gri... Multi-agent systems(MASs)are typically composed of multiple smart entities with independent sensing,communication,computing,and decision-making capabilities.Nowadays,MASs have a wide range of applications in smart grids,smart manufacturing,sensor networks,and intelligent transportation systems.Control of the MASs are often coordinated through information interaction among agents,which is one of the most important factors affecting coordination and cooperation performance.However,unexpected physical faults and cyber attacks on a single agent may spread to other agents via information interaction very quickly,and thus could lead to severe degradation of the whole system performance and even destruction of MASs.This paper is concerned with the safety/security analysis and synthesis of MASs arising from physical faults and cyber attacks,and our goal is to present a comprehensive survey on recent results on fault estimation,detection,diagnosis and fault-tolerant control of MASs,and cyber attack detection and secure control of MASs subject to two typical cyber attacks.Finally,the paper concludes with some potential future research topics on the security issues of MASs. 展开更多
关键词 CONSENSUS deception attack deny-of-service(DoS)attack fault detection fault estimation fault tolerant control multiagent systems
下载PDF
Vehicular Beacon Broadcast Scheduling Based on Age of Information(AoI) 被引量:5
10
作者 Yuanzhi Ni Lin Cai Yuming Bo 《China Communications》 SCIE CSCD 2018年第7期67-76,共10页
Vehicular beaconing plays an important role to facilitate various applications in the paradigm of Internet of Vehicles(IoV). Due to high dynamic and resource limitation in IoV, how to schedule the vehicular beacon bro... Vehicular beaconing plays an important role to facilitate various applications in the paradigm of Internet of Vehicles(IoV). Due to high dynamic and resource limitation in IoV, how to schedule the vehicular beacon broadcast is challenging, especially in dense scenarios. In this paper, we investigate the beacon broadcast scheduling problem considering the Age of Information(AoI). We first propose an algorithm minimizing the expected sum of AoI considering the limited communication resource and vehicle mobility. Then the performance of the proposed algorithm is analyzed. With the proposed algorithm, the optimal solution can be obtained under certain conditions. Extensive simulations are conducted to verify the efficiency, effectiveness and fairness of the proposed solution. 展开更多
关键词 车辆 广播 信息 年龄 资源限制 应用程序 因特网 挑战性
下载PDF
Mass transport deposits and processes in the north slope of the Xisha Trough,northern South China Sea 被引量:4
11
作者 QIN Zhiliang WU Shiguo +4 位作者 WANG Dawei LI Wei GONG Shaojun MI Lijun SPENCE George 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2015年第9期117-125,共9页
Triple mass-transport deposits (MTDs) with areas of 625, 494 and 902 km^2, respectively, have been identified on the north slope of the Xisha Trough, northern South China Sea margin. Based on high-resolution seismic... Triple mass-transport deposits (MTDs) with areas of 625, 494 and 902 km^2, respectively, have been identified on the north slope of the Xisha Trough, northern South China Sea margin. Based on high-resolution seismic reflection data and multi-beam bathymetric data, the Quaternary MTDs are characterized by typical geometric shapes and internal structures. Results of slope analysis showed that they are developed in a steep slope ranging from 5° to 35°. The head wall scarps of the MTDs arrived to 50 km in length (from headwall to termination). Their inner structures include well developed basal shear surface, growth faults, stepping lateral scarps, erosion grooves, and frontal thrust deformation. From seismic images, the central deepwater channel system of the Xisha Trough has been filled by interbedded channel-levee deposits and thick MTDs. Therefore, we inferred that the MTDs in the deepwater channel system could be dominated by far-travelled slope failure deposits even though there are local collapses of the trough walls. And then, we drew the two-dimensional process model and three- dimensional structure model diagram af the MTDs. Combined with the regional geological setting and previous studies, we discussed the trigger mechanisms of the triple MTDs. 展开更多
关键词 South China Sea mass transport deposits submarine slides gravity flow deepwater channel system
下载PDF
DC performance and AC loss of cable-in-conduit conductors for International Thermonuclear Experimental Reactor 被引量:2
12
作者 Wei Zhou Xin-Yu Fang +1 位作者 Jin Fang Bo Liu 《Nuclear Science and Techniques》 SCIE CAS CSCD 2016年第3期176-185,共10页
A reliable prediction of AC loss is essential for the application of International Thermonuclear Experimental Reactor(ITER) cable-in-conduit conductors(CICCs);however,the calculation of AC loss of ITER CICCs is a cumb... A reliable prediction of AC loss is essential for the application of International Thermonuclear Experimental Reactor(ITER) cable-in-conduit conductors(CICCs);however,the calculation of AC loss of ITER CICCs is a cumbersome task due to the complicated geometry of the multistage cables and the extreme operating conditions in ITER.In this paper,we described the models developed for hysteresis and coupling loss calculation,which can be suitable for the construction of ITER magnetic system.Meanwhile,we compared the results of theoretical analysis with the SULTAN test result to evaluate the numerical model we used.In addition,we introduced the n-value and AC loss with transport current for CICCs based on the DC measurement results at SULTAN,which lays the foundation for the further study. 展开更多
关键词 国际热核聚变实验堆 交流损耗 电缆导体 电缆导管 直流测量 ITER计划 国际热核实验反应堆 性能
下载PDF
A comparative study of semi-active control strategies for base isolated buildings 被引量:4
13
作者 Oliveira F. Morais P. Suleman A. 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2015年第3期487-502,共16页
A comparative analytical study of several control strategies for semi-active(SA) devices installed in baseisolated buildings aiming to reduce earthquake induced vibrations is presented.Three force tracking schemes com... A comparative analytical study of several control strategies for semi-active(SA) devices installed in baseisolated buildings aiming to reduce earthquake induced vibrations is presented.Three force tracking schemes comprising a linear controller plus a 'clipped' algorithm and a nonlinear output feedback controller(NOFC) are considered to tackle this problem.Linear controllers include the integral controller(I),the linear quadratic regulator(LQR) and the model predictive controller(MPC).A single degree-of-freedom system subjected to input accelerograms representative of the Portuguese seismic actions are first used to validate and evaluate the feasibility of these strategies.The obtained results show that structural systems using SA devices can in general outperform those equipped with passive devices for lower fundamental frequency structural systems,namely base-isolated buildings.The effectiveness of the proposed strategies is also evaluated on a 10 storey base-isolated dual frame-wall building.The force tracking scheme with an integral controller outperforms the other three as well as the original structure and the structure equipped with passive devices. 展开更多
关键词 semi-active control integral controller linear qua
下载PDF
INITIAL COEFFICIENT ESTIMATES FOR SOME SUBCLASSES OF M-FOLD SYMMETRIC BI-UNIVALENT FUNCTIONS 被引量:2
14
作者 H.M.SRIVASTAVA S.GABOURY F.GHANIM 《Acta Mathematica Scientia》 SCIE CSCD 2016年第3期863-871,共9页
In the present investigation, we consider two new general subclasses B∑m(T, λ; α)and B^∑m (τ λ;β) of Em consisting of analytic and m-fold symmetric bi-univalent functions in the open unit disk U. For functi... In the present investigation, we consider two new general subclasses B∑m(T, λ; α)and B^∑m (τ λ;β) of Em consisting of analytic and m-fold symmetric bi-univalent functions in the open unit disk U. For functions belonging to the two classes introduced here, we derive non-sharp estimates on the initial coefficients [a-~+ll and │a2+1│. Several connections to some of the earlier known results are also pointed out. 展开更多
关键词 analytic functions bi-univalent functions m-Fold symmetric functions m-Fold symmetric bi-univalent functions
下载PDF
Perspectives on the role of Pannexin 1 in neural precursor cell biology 被引量:1
15
作者 Juan C.Sanchez-Arias Leigh E.Wicki-Stordeur Leigh Anne Swayne 《Neural Regeneration Research》 SCIE CAS CSCD 2016年第10期1540-1544,共5页
We recently reported that targeted deletion of Pannexin 1 in neural precursor cells of the ventricular zone impairs the maintenance of these cells in healthy and stroke-injured brain. Here we frame this exciting new f... We recently reported that targeted deletion of Pannexin 1 in neural precursor cells of the ventricular zone impairs the maintenance of these cells in healthy and stroke-injured brain. Here we frame this exciting new finding in the context of our previous studies on Pannexin 1 in neural precursors as well as the close rela- tionship between Pannexin 1 and purinergic receptors established by other groups. Moreover, we identify important gaps in our understanding of Pannexin 1 in neural precursor cell biology in terms of the under- lying molecular mechanisms and functional/behavioural outcomes. 展开更多
关键词 neural precursor ventricular zone PANNEXIN ATP CYTOSKELETON PROLIFERATION phagoptosis
下载PDF
Numerical and experimental analysis of AC loss for CFETR CS model coil 被引量:1
16
作者 Wei Zhou Xin-Yu Fang +2 位作者 Jin Fang Yan-Chao Liu Bo Liu 《Nuclear Science and Techniques》 SCIE CAS CSCD 2017年第10期79-86,共8页
The central solenoid(CS) is an important component of China Fusion Engineering Test Reactor, for producing, forming and stabilizing plasma in the superconducting tokamak. It is a complicated work to design and manufac... The central solenoid(CS) is an important component of China Fusion Engineering Test Reactor, for producing, forming and stabilizing plasma in the superconducting tokamak. It is a complicated work to design and manufacture the large superconducting CS magnet, so it is meaningful to design a central solenoid model coil(CSMC) and analyze its electromagnetic properties in advance. In this paper, the structure, design parameters and magnetic field distribution of the CS model coil are discussed. The peak power of radial and axial turn conductors and time bucket loss are analyzed by using piecewise-linear method. The CSMC AC loss with different Nb3 Sn CICCs and AC loss of ITER CS coil are compared. The special electrometric method to measure AC loss of the CS model coil for future reference is presented. 展开更多
关键词 CS模型线圈 交流损耗 实验堆 数值分析 托卡马克等离子体 磁铁设计 NB3SN 聚变工程
下载PDF
Determining the mechanism behind yoga’s effects on preventing the symptoms of Alzheimer’s disease 被引量:1
17
作者 Adithy Hassan Meghan Robinson Stephanie M. Willerth 《Neural Regeneration Research》 SCIE CAS CSCD 2020年第2期261-262,共2页
Background on the relationship between meditation/yoga practice and its effect on Alzheimer's disease (AD): Dementia refers to a variety of conditions that affect the normal function of the brain, leading to sympt... Background on the relationship between meditation/yoga practice and its effect on Alzheimer's disease (AD): Dementia refers to a variety of conditions that affect the normal function of the brain, leading to symptoms like memory loss, issues with problem solving, difficulty in processing thoughts and disordered language (McKhann et al., 2011). 展开更多
关键词 EFFECTS YOGA Alzheimer's disease
下载PDF
Comparison of carbon-stock changes, eddycovariance carbon fluxes and model estimates in coastal Douglas-fir stands in British Columbia 被引量:1
18
作者 Colin J Ferster JA (Tony) Trofymow +2 位作者 Nicholas C Coops Baozhang Chen Thomas Andrew Black 《Forest Ecosystems》 SCIE CAS CSCD 2015年第2期104-122,共19页
Background: The global network of eddy-covariance (EC) flux-towers has improved the understanding of the terrestrial carbon (C) cycle, however, the network has a relatively limited spatial extent compared to fore... Background: The global network of eddy-covariance (EC) flux-towers has improved the understanding of the terrestrial carbon (C) cycle, however, the network has a relatively limited spatial extent compared to forest inventory data and plots. Developing methods to use inventory-based and EC flux measurements together with modeling approaches is necessary evaluate forest C dynamics across broad spatial extents. Methods: Changes in C stock change (AC) were computed based on repeated measurements of forest inventory plots and compared with separate measurements of cumulative net ecosystem productivity (~NEP) over four years (2003 - 2006) for Douglas-fir (Pseudotsuga menzies# var menziesil} dominated regeneration (HDF00), juvenile (HDF88 and HDF90) and near-rotation (DF49) aged stands (6, 18, 20, 57 years old in 2006, respectively) in coastal British Columbia. AC was determined from forest inventory plot data alone, and in a hybrid approach using inventory data along with litter fall data and published decay equations to determine the change in detrital pools. These AC-based estimates were then compared with Y_NEP measured at an eddy-covariance flux-tower (EC-flux) and modelled by the Carbon Budget Model - Canadian Forest Sector (CBM-CFS3) using historic forest inventory and forest disturbance data. Footprint analysis was used with remote sensing, soils and topography data to evaluate how well the inventory plots represented the range of stand conditions within the area of the flux-tower footprint and to spatially scale the plot data to the area of the EC-flux and model based estimates, Results: The closest convergence among methods was for the juvenile stands while the largest divergences were for the regenerating clearcut, followed by the near-rotation stand. At the regenerating clearcut, footprint weighting of CBM-CFS3 TNEP increased convergence with EC flux Z_NEP, but not for AC. While spatial scaling and footprint weighting did not increase convergence for AC, they did provide confidence that the sample plots represented site conditions as measured by the EC tower. Conclusions: Methods to use inventory and EC flux measurements together with modeling approaches are necessary to understand forest C dynamics across broad spatial extents. Each approach has advantages and limitations that need to be considered for investigations at varying spatial and temporal scales. 展开更多
关键词 Forest carbon MICROMETEOROLOGY Blometry Remote sensing Geographic information systems
下载PDF
APPLICATIONS OF HYPERGEOMETRIC SUMMATION THEOREMS OF KUMMER AND DIXON INVOLVING DOUBLE SERIES 被引量:1
19
作者 H.M.SRIVASTAVA M.I.QURESHI +1 位作者 Kaleem A.QURAISHI Ashish ARORA 《Acta Mathematica Scientia》 SCIE CSCD 2014年第3期619-628,共10页
Using series iteration techniques identities and apply each of these identities in we derive a number of general double series order to deduce several hypergeometric reduction formulas involving the Srivastava-Daoust ... Using series iteration techniques identities and apply each of these identities in we derive a number of general double series order to deduce several hypergeometric reduction formulas involving the Srivastava-Daoust double hypergeometric function. The results presented in this article are based essentially upon the hypergeometric summation theorems of Kummer and Dixon. 展开更多
关键词 Pochhammer's symbol Gamma function series identities hypergeometric re-duction formulas Srivastava-Daoust double and multiple hypergeometric func-tions Legendre's duplication formula Gauss-Legendre multiplication formula Kummer's theorem Dixon's theorem
下载PDF
Impacts of Land Use, Fertilizer and Manure Application on the Stream Nutrient Loadings in the Salmon River Watershed, South-Central British Columbia, Canada 被引量:2
20
作者 Zhanxue Zhu Klaas Broersma Asit Mazumder 《Journal of Environmental Protection》 2012年第8期809-822,共14页
Manure and fertilizer applications can increase soil productivity and land economic values, but the controversial result can be a decline of water quality due to the increased nutrient exports from soils to the stream... Manure and fertilizer applications can increase soil productivity and land economic values, but the controversial result can be a decline of water quality due to the increased nutrient exports from soils to the streams. The impacts of landuse, manure and fertilizer application on nutrient exports from soils to the streams were analyzed using the SWAT (Soil Water Assessment Tool) model for the Salmon River watershed in south-central British Columbia, Canada. The results showed that the animal farms had the highest rates of nutrient exports from soils to the streams and the natural forested lands had the lowest. It was estimated that the whole Salmon River watershed would export approximately 11.52 t·yr-1 of organic nitrogen (ON), 8.05 t·yr-1 of nitrate nitrogen (NO3-N), 2.30 t·yr-1 of organic phosphorus (OP) and 1.36 t·yr-1 of soluble reactive phosphorus (SRP) if the whole watershed was covered by natural vegetation without human disturbance. Current landuse changes, by converting natural vegetation lands to agriculture and animal farms and associated manure and fertilizer applications, have in-creased approximately 53.30 t·yr-1 of ON, 9.68 t·yr-1 of NO3-N, 22.69 t·y-1 of OP and 6.23 t·y-1 of SRP exports to the streams in the whole watershed. The SWAT model predicted that a daily 100 kg·ha-1 of fresh manure deposit from grazing cows during grazing season from later spring to later fall could increase 2.57 kg·ha-1·yr-1 of ON, 0.39 kg·ha-1·yr-1 of NO3-N, 2.35 kg·ha-1·yr-1 of OP and 0.48 kg·ha-1·yr-1 of SRP export to the streams. Fertilization could increase 1.57 kg ha-1 yr-1 of ON and 4.02 kg·ha-1·yr-1 of NO3-N export to the streams if 100 kg·ha-1·yr-1 of nitrogen (NH4NO3) fertilizer was applied in spring. Also fertilization could increase 1.18 kg·ha-1·yr-1 of OP and 0.20 kg·ha-1·yr-1 of SRP export to the streams if 100 kg·ha-1 phosphorus (P2O5) fertilizer was applied in spring. 展开更多
关键词 Model LANDUSE Nitrogen Phosphorus FERTILIZER MANURE
下载PDF
上一页 1 2 13 下一页 到第
使用帮助 返回顶部