期刊文献+
共找到1,373篇文章
< 1 2 69 >
每页显示 20 50 100
DNBP-CCA:A Novel Approach to Enhancing Heterogeneous Data Traffic and Reliable Data Transmission for Body Area Network
1
作者 Abdulwadood Alawadhi Mohd.Hasbullah Omar +3 位作者 Abdullah Almogahed Noradila Nordin Salman A.Alqahtani Atif M.Alamri 《Computers, Materials & Continua》 SCIE EI 2024年第5期2851-2878,共28页
The increased adoption of Internet of Medical Things (IoMT) technologies has resulted in the widespread use ofBody Area Networks (BANs) in medical and non-medical domains. However, the performance of IEEE 802.15.4-bas... The increased adoption of Internet of Medical Things (IoMT) technologies has resulted in the widespread use ofBody Area Networks (BANs) in medical and non-medical domains. However, the performance of IEEE 802.15.4-based BANs is impacted by challenges related to heterogeneous data traffic requirements among nodes, includingcontention during finite backoff periods, association delays, and traffic channel access through clear channelassessment (CCA) algorithms. These challenges lead to increased packet collisions, queuing delays, retransmissions,and the neglect of critical traffic, thereby hindering performance indicators such as throughput, packet deliveryratio, packet drop rate, and packet delay. Therefore, we propose Dynamic Next Backoff Period and Clear ChannelAssessment (DNBP-CCA) schemes to address these issues. The DNBP-CCA schemes leverage a combination ofthe Dynamic Next Backoff Period (DNBP) scheme and the Dynamic Next Clear Channel Assessment (DNCCA)scheme. The DNBP scheme employs a fuzzy Takagi, Sugeno, and Kang (TSK) model’s inference system toquantitatively analyze backoff exponent, channel clearance, collision ratio, and data rate as input parameters. Onthe other hand, the DNCCA scheme dynamically adapts the CCA process based on requested data transmission tothe coordinator, considering input parameters such as buffer status ratio and acknowledgement ratio. As a result,simulations demonstrate that our proposed schemes are better than some existing representative approaches andenhance data transmission, reduce node collisions, improve average throughput, and packet delivery ratio, anddecrease average packet drop rate and packet delay. 展开更多
关键词 Internet of Medical Things body area networks backoff period tsk fuzzy model clear channel assessment media access control
下载PDF
Reliability Analysis of Controller Area Network Based Systems—A Review 被引量:2
2
作者 Gerardine Immaculate Mary Zachariah C. Alex Lawrence Jenkins 《International Journal of Communications, Network and System Sciences》 2013年第4期155-166,共12页
This paper reviews the research work done on the Reliability Analysis of Controller Area Network (CAN) based systems. During the last couple of decades, real-time researchers have extended schedulability analysis to a... This paper reviews the research work done on the Reliability Analysis of Controller Area Network (CAN) based systems. During the last couple of decades, real-time researchers have extended schedulability analysis to a mature technique which for nontrivial systems can be used to determine whether a set of tasks executing on a single CPU or in a distributed system will meet their deadlines or not [1-3]. The main focus of the real-time research community is on hard real-time systems, and the essence of analyzing such systems is to investigate if deadlines are met in a worst case scenario. Whether this worst case actually will occur during execution, or if it is likely to occur, is not normally considered. Reliability modeling, on the other hand, involves study of fault models, characterization of distribution functions of faults and development of methods and tools for composing these distributions and models in estimating an overall reliability figure for the system [4]. This paper presents the research work done on reliability analysis developed with a focus on Controller-Area-Network-based automotive systems. 展开更多
关键词 Reliability Analysis of controlLER area network BASED SYSTEMS FAULT-TOLERANT CAN BASED SYSTEMS
下载PDF
Fuzzy Control Based on Neural Networks for Armored Vehicle Electric Drive System 被引量:1
3
作者 马晓军 李华 +1 位作者 张剑 张豫南 《Defence Technology(防务技术)》 SCIE EI CAS 2006年第3期169-172,共4页
关键词 装甲车 电力驱动 模糊控制 神经网络 鲁棒性
下载PDF
M/S Controller Area Network(CAN) System Using Shared-Clock Scheduler
4
作者 LIU Jianxin1,TAN Ping2,LIU Yu1 (1.School of Mechanical Engineering & Automation,Xihua University,Chengdu 610039,China 2.School of Mathematical & Computer Science,Xihua University,ChengDu 610039,China) 《武汉理工大学学报》 CAS CSCD 北大核心 2006年第S1期284-288,共5页
The Controller Area Network (CAN) is a well established control network for automotive and automation control applications. Time-Triggered Controller Area Network (TTCAN) is a recent development which introduces a ses... The Controller Area Network (CAN) is a well established control network for automotive and automation control applications. Time-Triggered Controller Area Network (TTCAN) is a recent development which introduces a session layer,for message scheduling,to the existing CAN standard,which is a two layer standard comprising of a physical layer and a data link layer. TTCAN facilitates network communication in a time-triggered fashion,by introducing a Time Division Multiple Access style communication scheme. This allows deterministic network behavior,where maximum message latency times can be quantified and guaranteed. In order to solve the problem of determinate time latency and synchronization among several districted units in one auto panel CAN systems,this paper proposed a prototype design implementation for a shared-clock scheduler based on PIC18F458 MCU. This leads to improved CAN system performance and avoid the latency jitters and guarantee a deterministic communication pattern on the bus. The real runtime performance is satisfied. 展开更多
关键词 TIME-TRIGGERED controller area network auto PANEL shared-clock SCHEDULER embedded SYSTEM
下载PDF
Error Control Strategy in Ultrasonic Body Area Networks
5
作者 Wenbin Liu Yongjian Yang +1 位作者 Fan Wang En Wang 《China Communications》 SCIE CSCD 2016年第11期244-259,共16页
Recently,ultrasonic waves had been introduced as the transmission medium in Body Area Networks(BANs) to reduce the incalculable damage caused by radio waves. However,the communications based on ultrasonic waves suffer... Recently,ultrasonic waves had been introduced as the transmission medium in Body Area Networks(BANs) to reduce the incalculable damage caused by radio waves. However,the communications based on ultrasonic waves suffer from poor propagation of signals in air and consume too much energy. To address these limitations,firstly,we make the theoretical analysis to ensure ultrasonic waves could be used in BANs(UBANs). Then,we propose an error control strategy in UBANs to dynamically adjust the error control scheme and the Max-Retries based on the current channel state,which is called UECS. The UECS is based on IEEE 802.15.6 standards and considering the characteristics of ultrasonic waves in BANs. Simulation results show that UECS achieves better performance in terms of packet delivery ratio and energy consumption compared with the traditional strategies. 展开更多
关键词 body area networks ULTRASONIC error control ultrasonic transducer
下载PDF
Single Phase Induction Motor Drive with Restrained Speed and Torque Ripples Using Neural Network Predictive Controller
6
作者 S. Saravanan K. Geetha 《Circuits and Systems》 2016年第11期3670-3684,共15页
In industrial drives, electric motors are extensively utilized to impart motion control and induction motors are the most familiar drive at present due to its extensive performance characteristic similar with that of ... In industrial drives, electric motors are extensively utilized to impart motion control and induction motors are the most familiar drive at present due to its extensive performance characteristic similar with that of DC drives. Precise control of drives is the main attribute in industries to optimize the performance and to increase its production rate. In motion control, the major considerations are the torque and speed ripples. Design of controllers has become increasingly complex to such systems for better management of energy and raw materials to attain optimal performance. Meager parameter appraisal results are unsuitable, leading to unstable operation. The rapid intensification of digital computer revolutionizes to practice precise control and allows implementation of advanced control strategy to extremely multifaceted systems. To solve complex control problems, model predictive control is an authoritative scheme, which exploits an explicit model of the process to be controlled. This paper presents a predictive control strategy by a neural network predictive controller based single phase induction motor drive to minimize the speed and torque ripples. The proposed method exhibits better performance than the conventional controller and validity of the proposed method is verified by the simulation results using MATLAB software. 展开更多
关键词 Dynamic Model Low Torque Ripples Neural Model Neural network Predictive controller Unstable Operation Single Phase Induction Motor Variable Speed drives
下载PDF
Availability evaluation of controller area networks under the influence of intermittent connection faults
7
作者 Longkai WANG Leiming ZHANG Yong LEI 《Frontiers of Information Technology & Electronic Engineering》 SCIE EI CSCD 2024年第4期555-568,共14页
Controller area networks(CANs),as one of the widely used fieldbuses in the industry,have been extended to the automation field with strict standards for safety and reliability.In practice,factors such as fatigue and i... Controller area networks(CANs),as one of the widely used fieldbuses in the industry,have been extended to the automation field with strict standards for safety and reliability.In practice,factors such as fatigue and insulation wear of the cables can cause intermittent connection(IC)faults to occur frequently in the CAN,which will affect the dynamic behavior and the safety of the system.Hence,quantitatively evaluating the performance of the CAN under the influence of IC faults is crucial to real-time health monitoring of the system.In this paper,a novel methodology is proposed for real-time quantitative evaluation of CAN availability when considering IC faults,with the system availability parameter being calculated based on the network state transition model.First,the causal relationship between IC fault and network error response is constructed,based on which the IC fault arrival rate is estimated.Second,the states of the network considering IC faults are analyzed,and the deterministic and stochastic Petri net(DSPN)model is applied to describe the transition relationship of the states.Then,the parameters of the DSPN model are determined and the availability of the system is calculated based on the probability distribution and physical meaning of markings in the DSPN model.A testbed is constructed and case studies are conducted to verify the proposed methodology under various experimental setups.Experimental results show that the estimation results obtained using the proposed method agree well with the actual values. 展开更多
关键词 controller area network Intermittent connection fault Arrival rate Deterministic and stochastic Petri net Availability evaluation
原文传递
Uniformed model of networked control systems with long time delay 被引量:4
8
作者 Zhu Qixin Liu Hongli Hu Shousong 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2008年第2期385-390,共6页
Feedback control systems wherein the control loops are closed through a real-time network are called networked control systems (NCS). The defining feature of an NCS is that information is exchanged using a network a... Feedback control systems wherein the control loops are closed through a real-time network are called networked control systems (NCS). The defining feature of an NCS is that information is exchanged using a network among control system components. Two new concepts including long time delay and short time delay are proposed. The sensor is almost always clock driven. The controller or the actuator is either clock driven or event driven. Four possible driving modes of networked control systems are presented. The open loop mathematic models of networked control systems with long time delay are developed when the system is driven by anyone of the four different modes. The uniformed modeling method of networked control systems with long time delay is proposed. The simulation results are given in the end. 展开更多
关键词 networked control systems time delay MODEL driving mode.
下载PDF
A Game Theoretic Approach for Inter-Network Interference Mitigation in Wireless Body Area Networks 被引量:1
9
作者 Du Dakun Hu Fengye +3 位作者 Wang Feng Wang Zhijun Du Yu Wang Lu 《China Communications》 SCIE CSCD 2015年第9期150-161,共12页
Wireless Body Area Network(WBAN) is an emerging technology to provide real-time health monitoring and ubiquitous healthcare services. In many applications, multiple wireless body area networks have to coexist in a sma... Wireless Body Area Network(WBAN) is an emerging technology to provide real-time health monitoring and ubiquitous healthcare services. In many applications, multiple wireless body area networks have to coexist in a small area, resulting in serious inter-network interference. This not only reduces network reliability that is especially important in emergency medical applications, but also consumes more power of WBANs. In this paper, an inter-network interference mitigation approach based on a power control algorithm is proposed. Power control is modeled as a non-cooperative game, in which both inter-network interference and energy efficiency of WBANs are considered. The existence and uniqueness of Nash Equilibrium in the game are proved, and an optimal scheme based on best response is proposed to find its Nash Equilibrium. By coordinating the transmission power levels among networks under interference environment, the total system throughput can be increased with minimum power consumed. The effectiveness of the proposed method has been illustrated by simulation results, where the performance of the proposed approach is evaluated in terms of overall utility and power efficiency and convergence speed. 展开更多
关键词 wireless body area network power control inter-network interference game theory
下载PDF
A novel strategy of smart manipulation by micro-scale oscillatory networks of the reactionary zones for enhanced extreme thrust control of the next-generation solid propulsion systems
10
作者 Alexander N.Lukin 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2018年第5期635-642,共8页
The main aim of this research is to get a better knowledge and understanding of the micro-scale oscillatory networks behavior in the solid propellants reactionary zones. Fundamental understanding of the micro-and nano... The main aim of this research is to get a better knowledge and understanding of the micro-scale oscillatory networks behavior in the solid propellants reactionary zones. Fundamental understanding of the micro-and nano-scale combustion mechanisms is essential to the development and further improvement of the next-generation technologies for extreme control of the solid propellant thrust. Both experiments and theory confirm that the micro-and nano-scale oscillatory networks excitation in the solid propellants reactionary zones is a rather universal phenomenon. In accordance with our concept,the micro-and nano-scale structures form both the fractal and self-organized wave patterns in the solid propellants reactionary zones. Control by the shape, the sizes and spacial orientation of the wave patterns allows manipulate by the energy exchange and release in the reactionary zones. A novel strategy for enhanced extreme thrust control in solid propulsion systems are based on manipulation by selforganization of the micro-and nano-scale oscillatory networks and self-organized patterns formation in the reactionary zones with use of the system of acoustic waves and electro-magnetic fields, generated by special kind of ring-shaped electric discharges along with resonance laser radiation. Application of special kind of the ring-shaped electric discharges demands the minimum expenses of energy and opens prospects for almost inertia-free control by combustion processes. Nano-sized additives will enhance self-organizing and self-synchronization of the micro-and nano-scale oscillatory networks on the nanometer scale. Suggested novel strategy opens the door for completely new ways for enhanced extreme thrust control of the solid propulsion systems. 展开更多
关键词 Solid propulsion systems EXTREME thrust control Reactionary ZONES MICRO-SCALE OSCILLATORY networkS Self-organized wave patterns Energy-releasing areas
下载PDF
A novel intrusion detection model for the CAN bus packet of in-vehicle network based on attention mechanism and autoencoder 被引量:1
11
作者 Pengcheng Wei Bo Wang +2 位作者 Xiaojun Dai Li Li Fangcheng He 《Digital Communications and Networks》 SCIE CSCD 2023年第1期14-21,共8页
The attacks on in-vehicle Controller Area Network(CAN)bus messages severely disrupt normal communication between vehicles.Therefore,researches on intrusion detection models for CAN have positive business value for veh... The attacks on in-vehicle Controller Area Network(CAN)bus messages severely disrupt normal communication between vehicles.Therefore,researches on intrusion detection models for CAN have positive business value for vehicle security,and the intrusion detection technology for CAN bus messages can effectively protect the invehicle network from unlawful attacks.Previous machine learning-based models are unable to effectively identify intrusive abnormal messages due to their inherent shortcomings.Hence,to address the shortcomings of the previous machine learning-based intrusion detection technique,we propose a novel method using Attention Mechanism and AutoEncoder for Intrusion Detection(AMAEID).The AMAEID model first converts the raw hexadecimal message data into binary format to obtain better input.Then the AMAEID model encodes and decodes the binary message data using a multi-layer denoising autoencoder model to obtain a hidden feature representation that can represent the potential features behind the message data at a deeper level.Finally,the AMAEID model uses the attention mechanism and the fully connected layer network to infer whether the message is an abnormal message or not.The experimental results with three evaluation metrics on a real in-vehicle CAN bus message dataset outperform some traditional machine learning algorithms,demonstrating the effectiveness of the AMAEID model. 展开更多
关键词 controller area network bus packet In-vehicle network Attention mechanism Autoencoder
下载PDF
Energy-Efficieng MAC Protocols for Wireless Body Area Networks: A Survey
12
作者 Sai Anand Gopalan Jong-Tae Park 《China Communications》 SCIE CSCD 2011年第5期1-10,共10页
In this paper, we provide a comprehensive survey of key energy-efficient Medium Access Control (MAC) protocols for Wireless Body Area Networks (WBANs). At the outset, we outline the crucial attributes of a good MAC pr... In this paper, we provide a comprehensive survey of key energy-efficient Medium Access Control (MAC) protocols for Wireless Body Area Networks (WBANs). At the outset, we outline the crucial attributes of a good MAC protocol for WBAN. Several sources that contribute to the energy inefficiency of WBAN are identified, and features of the various MAC protocols qualitatively compared. Then, we further investigate some representative TDMA-based energy-efficient MAC protocols for WBAN by emphasizing their strengths and weaknesses. Finally, we conclude with a number of open research issues with regard to WBAN MAC layer. 展开更多
关键词 Medium Access control (MAC) Wireless Body area networks (WBANs) ENERGY-EFFICIENCY
下载PDF
Simulation of Optical Packet-Switched Metropolitan Area Network
13
作者 朱炳春 贾潞华 +2 位作者 王春华 黄肇明 阎晓光 《Journal of Shanghai University(English Edition)》 CAS 2002年第2期154-157,共4页
This paper introduces architectures of two types optical packet switched metropolitan area networks and their media access control protocols. We have designed related network simulation systems. With these simulation... This paper introduces architectures of two types optical packet switched metropolitan area networks and their media access control protocols. We have designed related network simulation systems. With these simulation systems, the characteristics and performance of the two MANs can be achieved. 展开更多
关键词 optical packet switching media access control (MAC) wavelength division multiplexing (WDM) metropolitan area network (MAN) IP over WDM.
下载PDF
MAC Layer Resource Allocation for Wireless Body Area Networks
14
作者 Qinghua Shen Xuemin (Sherman) Shen +1 位作者 Tom H.Luan Jing Liu 《ZTE Communications》 2014年第3期13-21,共9页
Wireless body area networks (WBANs) can provide low-cost, timely healthcare services and are expected to be widely used for e-healthcare in hospitals. In a hospital, space is often limited and multiple WBANs have to... Wireless body area networks (WBANs) can provide low-cost, timely healthcare services and are expected to be widely used for e-healthcare in hospitals. In a hospital, space is often limited and multiple WBANs have to coexist in an area and share the same channel in order to provide healthcare services to different patients. This causes severe interference between WBANs that could significantly reduce the network throughput and increase the amount of power consumed by sensors placed on the body. There-fore, an efficient channel-resource allocation scheme in the medium access control (MAC) layer is crucial. In this paper, we devel-op a centralized MAC layer resource allocation scheme for a WBAN. We focus on mitigating the interference between WBANs and reducing the power consumed by sensors. Channel and buffer state are reported by smartphones deployed in each WBAN, and channel access allocation is performed by a central controller to maximize network throughput. Sensors have strict limitations in terms of energy consumption and computing capability and cannot provide all the necessary information for channel allocation in a timely manner. This deteriorates network performance. We exploit the temporal correlation of the body area channel in order to minimize the number of channel state reports necessary. We view the network design as a partly observable optimization prob-lem and develop a myopic policy, which we then simulate in Matlab. 展开更多
关键词 medium access control (MAC) wireless body area networks (WBANs) resource allocation interference mitigation partially observable optimization
下载PDF
Implementation of Adaptive Neuro Fuzzy Inference System in Speed Control of Induction Motor Drives
15
作者 K. Naga Sujatha K. Vaisakh 《Journal of Intelligent Learning Systems and Applications》 2010年第2期110-118,共9页
A new speed control approach based on the Adaptive Neuro-Fuzzy Inference System (ANFIS) to a closed-loop, variable speed induction motor (IM) drive is proposed in this paper. ANFIS provides a nonlinear modeling of mot... A new speed control approach based on the Adaptive Neuro-Fuzzy Inference System (ANFIS) to a closed-loop, variable speed induction motor (IM) drive is proposed in this paper. ANFIS provides a nonlinear modeling of motor drive system and the motor speed can accurately track the reference signal. ANFIS has the advantages of employing expert knowledge from the fuzzy inference system and the learning capability of neural networks. The various functional blocks of the system which govern the system behavior for small variations about the operating point are derived, and the transient responses are presented. The proposed (ANFIS) controller is compared with PI controller by computer simulation through the MATLAB/SIMULINK software. The obtained results demonstrate the effectiveness of the proposed control scheme. 展开更多
关键词 ANFIS controlLER PI controlLER Fuzzy LOGIC controlLER Artificial NEURAL network controlLER INDUCTION MOTOR drive
下载PDF
A Realistic ICT Network Design and Implementation in the Neighbourhood Area of the Smart Grid
16
作者 Zoya Pourmirza John M. Brooke 《Smart Grid and Renewable Energy》 2013年第6期436-448,共13页
The Smart Grid has three main characteristics, which are to some degree antagonistic. These characteristics are: provision of good power quality, energy cost reduction and improvement in the reliability of the grid. T... The Smart Grid has three main characteristics, which are to some degree antagonistic. These characteristics are: provision of good power quality, energy cost reduction and improvement in the reliability of the grid. The need to ensure that they can be accomplished together demands a much richer ICT monitoring and control network than the current system. In this paper we particularly investigate the design and deployment of the ICT system in the urban environment, specifically in a university campus that is embedded in a city, thus it represents the Neighbourhood Area Network (NAN) level of the Smart Grid. In order to design an ICT infrastructure, we have introduced two related architectures: namely communications network architecture and a software architecture. Having access to the characteristics of a real NAN guides us to choose appropriate communication technologies and identify the actual requirements of the system. To implement these architectures at this level we need to gather and process information from environmental sensors (monitoring e.g. temperature, movement of people and vehicles) that can provide useful information about changes in the loading of the NAN, with information from instrumentation of the Power Grid itself. Energy constraints are one of the major limitations of the communication network in the Smart Grid, especially where wireless networking is proposed. Thus we analyse the most energy efficient method of collecting and sending data. The main contribution of this research is that we propose and implement an energy efficient ICT network and describe our software architecture at the NAN level, currently very underdeveloped. We also discuss our experimental results. To our knowledge, no such architectures have yet been implemented for collecting data which can provide the basis of Decision Support Tools (DSTs). 展开更多
关键词 SMART GRID ICT network Neighbourhood area network Communication ARCHITECTURE Monitoring and control Software ARCHITECTURE
下载PDF
Resource Exhaustion Attack Detection Scheme for WLAN Using Artificial Neural Network
17
作者 Abdallah Elhigazi Abdallah Mosab Hamdan +6 位作者 Shukor Abd Razak Fuad A.Ghalib Muzaffar Hamzah Suleman Khan Siddiq Ahmed Babikir Ali Mutaz H.H.Khairi Sayeed Salih 《Computers, Materials & Continua》 SCIE EI 2023年第3期5607-5623,共17页
IEEE 802.11 Wi-Fi networks are prone to many denial of service(DoS)attacks due to vulnerabilities at the media access control(MAC)layer of the 802.11 protocol.Due to the data transmission nature of the wireless local ... IEEE 802.11 Wi-Fi networks are prone to many denial of service(DoS)attacks due to vulnerabilities at the media access control(MAC)layer of the 802.11 protocol.Due to the data transmission nature of the wireless local area network(WLAN)through radio waves,its communication is exposed to the possibility of being attacked by illegitimate users.Moreover,the security design of the wireless structure is vulnerable to versatile attacks.For example,the attacker can imitate genuine features,rendering classificationbased methods inaccurate in differentiating between real and false messages.Althoughmany security standards have been proposed over the last decades to overcome many wireless network attacks,effectively detecting such attacks is crucial in today’s real-world applications.This paper presents a novel resource exhaustion attack detection scheme(READS)to detect resource exhaustion attacks effectively.The proposed scheme can differentiate between the genuine and fake management frames in the early stages of the attack such that access points can effectively mitigate the consequences of the attack.The scheme is built through learning from clustered samples using artificial neural networks to identify the genuine and rogue resource exhaustion management frames effectively and efficiently in theWLAN.The proposed scheme consists of four modules whichmake it capable to alleviates the attack impact more effectively than the related work.The experimental results show the effectiveness of the proposed technique by gaining an 89.11%improvement compared to the existing works in terms of detection. 展开更多
关键词 802.11 media access control(MAC) wireless local area network(WLAN) artificial neural network denial-of-service(DoS)
下载PDF
Adaptive Generalized Synchronization of Drive-Response Neural Networks with Time-Varying Delay
18
作者 Lirong Zhu 《Applied Mathematics》 2022年第1期19-26,共8页
This paper studies the generalized synchronization of a class of drive-response neural networks with time-varying delay. When the topological structures of the drive-response neural networks are known, by designing an... This paper studies the generalized synchronization of a class of drive-response neural networks with time-varying delay. When the topological structures of the drive-response neural networks are known, by designing an appropriate nonlinear adaptive controller, the generalized synchronization of these two networks is obtained based on Lyapunov stability theory and LaSalle’s invariance principle. 展开更多
关键词 Generalized Synchronization drive-Response Neural network Time-Varying Delay Adaptive controller
下载PDF
苏南水网地区水域景观破碎化时空演变特征及驱动因子研究——以吴江区为例 被引量:3
19
作者 丁金华 许艳秋 钱晶 《西北林学院学报》 CSCD 北大核心 2024年第1期247-255,共9页
以苏州吴江区为对象,选取1990、2000、2010、2020年土地利用数据,利用Fragstats4.2对1990-2020年水域景观破碎化演化特征进行定量分析,并借助地理探测器模型探讨水域景观破碎化时空特征的驱动因子。结果表明:(1)从景观水平破碎化特征分... 以苏州吴江区为对象,选取1990、2000、2010、2020年土地利用数据,利用Fragstats4.2对1990-2020年水域景观破碎化演化特征进行定量分析,并借助地理探测器模型探讨水域景观破碎化时空特征的驱动因子。结果表明:(1)从景观水平破碎化特征分析来看,研究期内吴江区水域景观破碎化程度先增大后减缓:1990-2000年水域景观受到人工建设干扰,空间分布离散;2000-2020年水域景观破碎化程度降低、整体空间格局趋向整合。从类型水平破碎化特征分析,河流、湖泊及内陆滩涂在1990-2000年破碎化程度日益加剧,斑块空间分布离散,2000-2020年水域斑块连接性逐渐增强;水库坑塘斑块类型分布在1990-2010年破碎程度降低,2010年后破碎化程度上升。(2)吴江区水域景观破碎化受到自然、社会等多元因素影响,各因子对水域景观破碎化时空分异的影响明显不同,且各驱动因子间存在显著交互增强效应,其中人类活动强度因子影响最为显著。研究结果可为探明水域景观破碎化形成机理提供思路,对苏南水网地区生态环境保护和可持续发展具有参考意义。 展开更多
关键词 水网地区 景观破碎化 时空演变 驱动因子
下载PDF
基于CNN-OBIA的黄河源区水体提取及时空变化
20
作者 陈伟 张秀霞 +3 位作者 党星海 樊新成 李旺平 徐俊伟 《人民长江》 北大核心 2024年第4期133-141,共9页
准确识别水体信息是分析地表水时空动态变化的重要技术手段。针对目前各种长时序水体信息提取方法精度低的问题,基于Landsat遥感影像,选用1986~2022年5484景黄河源区遥感影像,分别运用卷积神经网络结合面向对象(CNN-OBIA)和多指数水体... 准确识别水体信息是分析地表水时空动态变化的重要技术手段。针对目前各种长时序水体信息提取方法精度低的问题,基于Landsat遥感影像,选用1986~2022年5484景黄河源区遥感影像,分别运用卷积神经网络结合面向对象(CNN-OBIA)和多指数水体检测规则(MIWDR)两种方法提取了黄河源区的地表水体,并对两种方法的提取精度进行了对比分析。在此基础上,探究了1986~2022年黄河源区水体信息的时空变化特征,并对其主要气候因素进行相关分析。结果表明:①CNN-OBIA的总体精度和Kappa系数分别为96.78%和0.93,MIWDR的总体精度和Kappa系数分别为94.28%和0.88,总体而言,CNN-OBIA的提取精度高于MIWDR方法。CNN-OBIA的提取结果可以很好地保持水体边界完整性和有效去除山体阴影,可以较好地对细小河流进行提取。②研究区水体总面积呈现出先减少(1986~2001年)后增加(2001~2022年)的变化趋势。③相关性分析表明,降水和气温与水体面积的变化均表现出显著正相关。 展开更多
关键词 水体面积提取 卷积神经网络 面向对象 驱动力分析 黄河源区
下载PDF
上一页 1 2 69 下一页 到第
使用帮助 返回顶部