期刊文献+
共找到1,204篇文章
< 1 2 61 >
每页显示 20 50 100
Attractor-Based Simultaneous Design of the Minimum Set of Control Nodes and Controllers in Boolean Networks
1
作者 Koichi Kobayashi 《Applied Mathematics》 2016年第14期1510-1520,共11页
Design of control strategies for gene regulatory networks is a challenging and important topic in systems biology. In this paper, the problem of finding both a minimum set of control nodes (control inputs) and a contr... Design of control strategies for gene regulatory networks is a challenging and important topic in systems biology. In this paper, the problem of finding both a minimum set of control nodes (control inputs) and a controller is studied. A control node corresponds to a gene that expression can be controlled. Here, a Boolean network is used as a model of gene regulatory networks, and control specifications on attractors, which represent cell types or states of cells, are imposed. It is important to design a gene regulatory network that has desired attractors and has no undesired attractors. Using a matrix-based representation of BNs, this problem can be rewritten as an integer linear programming problem. Finally, the proposed method is demonstrated by a numerical example on a WNT5A network, which is related to melanoma. 展开更多
关键词 Boolean Networks Integer Linear Programming Minimum Set of control nodes Singleton Attractors
下载PDF
Deducing Complete Selection Rule Set for Driver Nodes to Guarantee Network’s Structural Controllability 被引量:4
2
作者 Xichen Wang Yugeng Xi +1 位作者 Wenzhen Huang Shuai Jia 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2019年第5期1152-1165,共14页
Structural controllability is critical for operating and controlling large-scale complex networks. In real applications, for a given network, it is always desirable to have more selections for driver nodes which make ... Structural controllability is critical for operating and controlling large-scale complex networks. In real applications, for a given network, it is always desirable to have more selections for driver nodes which make the network structurally controllable. Different from the works in complex network field where structural controllability is often used to explore the emergence properties of complex networks at a macro level,in this paper, we investigate it for control design purpose at the application level and focus on describing and obtaining the solution space for all selections of driver nodes to guarantee structural controllability. In accord with practical applications,we define the complete selection rule set as the solution space which is composed of a series of selection rules expressed by intuitive algebraic forms. It explicitly indicates which nodes must be controlled and how many nodes need to be controlled in a node set and thus is particularly helpful for freely selecting driver nodes. Based on two algebraic criteria of structural controllability, we separately develop an input-connectivity algorithm and a relevancy algorithm to deduce selection rules for driver nodes. In order to reduce the computational complexity,we propose a pretreatment algorithm to reduce the scale of network's structural matrix efficiently, and a rearrangement algorithm to partition the matrix into several smaller ones. A general procedure is proposed to get the complete selection rule set for driver nodes which guarantee network's structural controllability. Simulation tests with efficiency analysis of the proposed algorithms are given and the result of applying the proposed procedure to some real networks is also shown, and these all indicate the validity of the proposed procedure. 展开更多
关键词 ALGEBRAIC criteria COMPLETE SELECTION rule set structural controlLABILITY DRIVER nodeS
下载PDF
Shift control method for the local time at descendi ngnode based on sun-synchronous orbit satellite 被引量:5
3
作者 Yang Yong'an Feng Zuren +1 位作者 Sun Linyan Tan Wei 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第1期141-145,共5页
This article analyzes the shift factors of the descending node local time for sun-synchronous satellites and proposes a shift control method to keep the local time shift within an allowance range. It is found that the... This article analyzes the shift factors of the descending node local time for sun-synchronous satellites and proposes a shift control method to keep the local time shift within an allowance range. It is found that the satellite orbit design and the orbit injection deviation are the causes for the initial shift velocity, whereas the atmospheric drag and the sun gravitational perturbation produce the shift acceleration. To deal with these shift factors, a shift control method is put forward, through such methods as orbit variation design, orbit altitude, and inclination keeping control. The simulation experiment and practical application have proved the effectiveness of this control method. 展开更多
关键词 space engineering sun-synchronous orbit satellite local time of descending node drift control method.
下载PDF
Receiver-Controlled Multi-Node Cooperation
4
作者 Liang Ye Yue Li +1 位作者 Xue-Jun Sha Esko Alasaarela 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2014年第2期6-12,共7页
Since wireless links in Ad hoc networks are more fragile than those in traditional wireless networks due to route flapping,multi-node cooperation plays an important role in ensuring the quality of service( QoS). Based... Since wireless links in Ad hoc networks are more fragile than those in traditional wireless networks due to route flapping,multi-node cooperation plays an important role in ensuring the quality of service( QoS). Based on the authors' previous work,this paper proposes a receiver-controlled multi-node cooperation routing protocol,known as AODV-RCC. In this protocol,nodes form a cooperation group based on signal power. In a cooperation group,signal power between a partner and a transmitter,as well as signal power between the partner and the receiver,must be larger than the signal power between the transmitter and the receiver. Otherwise,the transmission will not benefit from cooperation. To avoid collision or congestion,each cooperation group only contains one partner. This partner offers both data and ACK cooperative retransmission. Its retransmission time should be shorter than the internal retry time of the transmitter's MAC layer,because it is better for the partner to retransmit firstly,as it offers a more reliable cooperative link. In AODV-RCC,it is the receiver that chooses the partner,because the link between the partner and the receiver is the most important. According to our simulation results,AODV-RCC shortens the end-to-end delay and increases the packet delivery ratio. 展开更多
关键词 multi-node cooperation receiver-controlled routing protocol Ad hoc network
下载PDF
基于NodeMCU的智能浇灌系统设计
5
作者 刘睿 张秀再 许芝也 《信息技术》 2024年第6期29-35,共7页
当前,智能化技术不断发展,为了提升现代农田的智能化管理水平,设计以NodeMCU(节点微控制单元)作为中央控制器的智能浇灌系统,实现农田灌溉智能化。YL-69土壤湿度传感器用于检测土壤含水量,DHT11温湿度传感器用于检测环境温度和湿度,中... 当前,智能化技术不断发展,为了提升现代农田的智能化管理水平,设计以NodeMCU(节点微控制单元)作为中央控制器的智能浇灌系统,实现农田灌溉智能化。YL-69土壤湿度传感器用于检测土壤含水量,DHT11温湿度传感器用于检测环境温度和湿度,中央控制器负责数据的采集与处理,通过内置的ESP8266芯片连接Wi-Fi将数据无线传输至网页端进行实时监测与控制,并对比系统设置的阈值指标,反馈至微控制器,微控制器通过控制继电器打开水泵对土地浇灌,并且搭建数据库进行数据记录与分析。该系统结构简单,可靠性较高,可实现浇灌的无人化管理,具有重要的现实意义。 展开更多
关键词 节点微控制单元 智能浇灌 YL-69土壤湿度传感器 DHT11温湿度传感器 无线传输
下载PDF
基于Node-red的云端智能生产线控制系统设计与实现
6
作者 陈玄烨 张鑫 +2 位作者 张景翔 文世华 李红利 《山东工业技术》 2024年第3期58-62,共5页
针对传统生产线在刚性生产过程中面临的成本过高、远程实施难、兼容性低等关键问题,基于目前中小企业的技术基础相对薄弱,无法将云计算平台、数据存储和处理等设备及技术运用到实际生产中的现状,本文利用西门子S7-1200 PLC作为核心控制... 针对传统生产线在刚性生产过程中面临的成本过高、远程实施难、兼容性低等关键问题,基于目前中小企业的技术基础相对薄弱,无法将云计算平台、数据存储和处理等设备及技术运用到实际生产中的现状,本文利用西门子S7-1200 PLC作为核心控制器,基于Node-red平台设计了成本低、兼容性高的云端智能生产线监控系统,便于实现对于生产线的监视和控制,提高生产效率与产品质量。现场运行表明,该系统运行稳定,满足智能生产线的设计要求,同时具备部署成本低、兼容性高的突出优势。 展开更多
关键词 工业物联网 node-red 智能生产线 云端控制系统
下载PDF
IEEE 802.11e Medium Access Control层QoS机制的改进研究
7
作者 周立衡 邱恭安 章国安 《南通大学学报(自然科学版)》 CAS 2009年第3期6-9,共4页
针对IEEE802.11e Medium Access Control层的QoS机制高负载时存在远端节点冲突和低优先级业务资源被耗尽的问题,提出在牺牲较小带宽的基础上增加一条忙音信道,取代CTS帧在数据信道上的广播,减少远端节点的冲突.仿真结果表明,该方案具有... 针对IEEE802.11e Medium Access Control层的QoS机制高负载时存在远端节点冲突和低优先级业务资源被耗尽的问题,提出在牺牲较小带宽的基础上增加一条忙音信道,取代CTS帧在数据信道上的广播,减少远端节点的冲突.仿真结果表明,该方案具有较小的冲突概率,有效地减少了远端节点冲突.同时提出一个解决公平性问题的新思路:在避退时间发送忙音抢占信道,以期提高低优先级业务的接入概率. 展开更多
关键词 IEEE 802.11e MEDIUM ACCESS control QOS机制 远端节点冲突 改进方案
下载PDF
Input Structure Design for Structural Controllability of Complex Networks 被引量:1
8
作者 Lifu Wang Zhaofei Li +2 位作者 Guotao Zhao Ge Guo Zhi Kong 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2023年第7期1571-1581,共11页
This paper addresses the problem of the input design of large-scale complex networks.Two types of network components,redundant inaccessible strongly connected component(RISCC)and intermittent inaccessible strongly con... This paper addresses the problem of the input design of large-scale complex networks.Two types of network components,redundant inaccessible strongly connected component(RISCC)and intermittent inaccessible strongly connected component(IISCC)are defined,and a subnetwork called a driver network is developed.Based on these,an efficient method is proposed to find the minimum number of controlled nodes to achieve structural complete controllability of a network,in the case that each input can act on multiple state nodes.The range of the number of input nodes to achieve minimal control,and the configuration method(the connection between the input nodes and the controlled nodes)are presented.All possible input solutions can be obtained by this method.Moreover,we give an example and some experiments on real-world networks to illustrate the effectiveness of the method. 展开更多
关键词 Complex network input configuration minimum controlled node set structural controllability
下载PDF
基于NodeMCU的智能玻璃百叶窗控制系统的设计 被引量:1
9
作者 林朋右 王佳豪 蔡益富 《黑龙江科学》 2023年第16期130-133,共4页
基于Node MCU设计了智能玻璃百叶窗控制系统,使用PWM控制信号控制数字舵机的旋转角度,根据传感器反馈信号自动对百叶窗进行开合调整,使用PID控制算法提高了控制精度及稳定性。通过传感器实时监测室内外光线及温度等环境参数,以优化室内... 基于Node MCU设计了智能玻璃百叶窗控制系统,使用PWM控制信号控制数字舵机的旋转角度,根据传感器反馈信号自动对百叶窗进行开合调整,使用PID控制算法提高了控制精度及稳定性。通过传感器实时监测室内外光线及温度等环境参数,以优化室内光线及温度,提高舒适度与能源利用率。该系统通过WiFi连接实现与手机端的通信,支持手动控制与远程控制,便于用户随时随地对百叶窗进行调节,可广泛应用于住宅、办公室、商业建筑等场所,具有较高的实用价值及市场潜力,为智能家居的发展提供了新思路。 展开更多
关键词 自动调节 百叶窗 node MCU 智能控制
下载PDF
A New Storage Strategy for Hypertext Based Version Control
10
作者 王岩 郭福顺 +1 位作者 李莲治 魏玲 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 1996年第3期14-19,共6页
Version control is an urgent problem to be solved at present for data management. Based on the authors' hypertext data model with version control,some details about the storage strategy are discussed. A new strate... Version control is an urgent problem to be solved at present for data management. Based on the authors' hypertext data model with version control,some details about the storage strategy are discussed. A new strategy to define some key nodes within the version derivation graph is presented and some implementation details are described. At last, the performance of different strategies are compared with each other. 展开更多
关键词 ss: HYPERTEXT VERSION control VERSION node key node VERSION DERIVATION GRAPH
下载PDF
Do you want to participate in a clinical study as a healthy control?-Risk or benefit? 被引量:2
11
作者 Hanna Giessen Christian A Nebiker +3 位作者 Matthias Bruehlmeier Stefan Spreitzer Beat Mueller Philipp Schuetz 《World Journal of Clinical Cases》 SCIE 2017年第12期437-439,共3页
A healthy woman volunteered to participate as "healthy control" in a study.An increased level of procalcitonin(PCT) was detected and remained elevated on follow-up measurements.As calcitonin levels were elev... A healthy woman volunteered to participate as "healthy control" in a study.An increased level of procalcitonin(PCT) was detected and remained elevated on follow-up measurements.As calcitonin levels were elevated as well,thyroid ultrasound was performed which revealed nodes in both thyroid lobes,one of them showing metabolic activity in positron emission tomography-computed tomography scan.To exclude a malignant thyroid cancer despite the negative findings in a fine needle aspiration the patient underwent thyroidectomy and a medullary thyroid carcinoma(MTC) was detected in the right lobe.MTC is a rare endocrine tumor with a poor prognosis once having spread,therefore early detection remains a priority for the outcome.Screening parameter is serum calcitonin,in absence of infection the pro-hormone PCT can be used as a screening parameter as well with high sensitivity. 展开更多
关键词 MEDULLARY THYROID cancer PROCALCITONIN THYROID nodes ENDOCRINOLOGY Public health HEALTHY control
下载PDF
基于虚拟领导节点改进的孤岛微电网完全分布式二次调频策略 被引量:1
12
作者 李志军 苗庆玉 张家安 《太阳能学报》 EI CAS CSCD 北大核心 2024年第5期333-342,共10页
传统分布式二次调频策略在虚拟领导节点频率信息出现故障时会导致微电网系统频率无法恢复,针对该问题提出并设计一种完全分布式二次调频策略。首先分析传统分布式二次调频策略虚拟领导节点故障对二次调频过程产生的影响;然后,结合一致... 传统分布式二次调频策略在虚拟领导节点频率信息出现故障时会导致微电网系统频率无法恢复,针对该问题提出并设计一种完全分布式二次调频策略。首先分析传统分布式二次调频策略虚拟领导节点故障对二次调频过程产生的影响;然后,结合一致性算法对传统分布式二次调频控制器加以改进,通过将调频补偿量与频率偏差的对消作为“频率引导项”加入各分布式控制器中,使得各分布式发电单元完全对等,以保证虚拟领导节点去除后频率的正常恢复,实现完全分布式控制;最后,通过仿真验证所提方法在保证频率恢复方面的有效性与优越性。 展开更多
关键词 微电网 调频 多智能体系统 完全分布式控制 虚拟领导节点
下载PDF
A Study of Model for Distributed Measurement and Control System 被引量:2
13
作者 张劲 钟毅芳 《微计算机信息》 2003年第9期17-20,共4页
This paper is concerned with a method for forming distributed measurement and control system.A three-layer structure model based on network,physical node layer and func-tion node layer is discussed.It is designed on o... This paper is concerned with a method for forming distributed measurement and control system.A three-layer structure model based on network,physical node layer and func-tion node layer is discussed.It is designed on object-oriented software method.The model has a fine application prospect. 展开更多
关键词 分布式测控系统 面向对象 框架模型 软件方法 网络协议
下载PDF
Network security protection technology for a cloud energy storage network controller
14
作者 Tao Yan Jialiang Liu +3 位作者 Qianqian Niu Jizhong Chen Shaohua Xu Meng Niu 《Global Energy Interconnection》 2020年第1期86-98,共13页
As part of the ongoing information revolution,smart power grid technology has become a key focus area for research into power systems.Intelligent electrical appliances are now an important component of power systems,p... As part of the ongoing information revolution,smart power grid technology has become a key focus area for research into power systems.Intelligent electrical appliances are now an important component of power systems,providing a smart power grid with increased control,stability,and safety.Based on the secure communication requirements of cloud energy storage systems,this paper presents the design and development of a node controller for a cloud energy storage network.The function division and system deployment processes were carried out to ensure the security of the communication network used for the cloud energy storage system.Safety protection measures were proposed according to the demands of the communication network,allowing the system to run safely and stably.Finally,the effectiveness of the system was verified through a client-side distributed energy storage demonstration project in Suzhou,China.The system was observed to operate safely and stably,demonstrating good peak-clipping and valley filling effects,and improving the system load characteristics. 展开更多
关键词 CLOUD ENERGY STORAGE system node controlLER Network security Smart grid Distributed ENERGY STORAGE
下载PDF
Energy Efficient Direction-Based Topology Control Algorithm for WSN
15
作者 Muhammad Asghar Khan Sadam Hussain 《Wireless Sensor Network》 2020年第3期37-47,共11页
A wireless sensor network consists of hundreds or thousands of small nodes which could either have a static or dynamic position. These nodes are deployed through normal or random distribution to report events of a par... A wireless sensor network consists of hundreds or thousands of small nodes which could either have a static or dynamic position. These nodes are deployed through normal or random distribution to report events of a particular area to the base station through sink nodes. Having limited onboard energy of sensor nodes, conservation of energy in wireless sensor network is necessary. For this purpose, a new algorithm is proposed titled Energy-Efficient-Direction-Based-Topology-Control-Algorithm (EEDBTC). In proposed algorithm<span>,</span><span><span> direction is the main concern whenever an event occurs the node will send data in the direction of base station so that less energy is consumed. The </span><span>results of the same were compared with customary dense wireless sensor</span><span> network, color based WSNs and it was observed that this algorithm is much better than previous topology control algorithms used.</span></span> 展开更多
关键词 Sensor nodes Topology control Energy Conservation Energy Efficiency
下载PDF
Issues and Challenges in Node Connectivity in Mobile Ad Hoc Networks: A Holistic Review 被引量:2
16
作者 Mohit Jain Satish Chand 《Wireless Engineering and Technology》 2016年第1期24-35,共12页
One of the fundamental properties of an ad hoc network is its connectivity. Maintaining connectivity in wireless networks is extremely difficult due to dynamic changing topology of MANETs. There are several techniques... One of the fundamental properties of an ad hoc network is its connectivity. Maintaining connectivity in wireless networks is extremely difficult due to dynamic changing topology of MANETs. There are several techniques to understand the connectivity level for a given network topology. In this paper, we examine the existing methods and discuss the issues and challenges that are still insurmountable in order to enhance the connectivity properties of wireless multi hop networks. 展开更多
关键词 Ad Hoc Networks CONNECTIVITY Topology control Critical Transmitting Range node Density Energy Consumpution Routing Critical Points k-Connectivity
下载PDF
Hardware/Compiler Memory Protection in Sensor Nodes
17
作者 Lanfranco LOPRIORE 《International Journal of Communications, Network and System Sciences》 2008年第3期235-240,共6页
With reference to sensor node architectures, we consider the problem of supporting forms of memory protection through a hardware/compiler approach that takes advantage of a low-cost protection circuitry inside the mic... With reference to sensor node architectures, we consider the problem of supporting forms of memory protection through a hardware/compiler approach that takes advantage of a low-cost protection circuitry inside the microcontroller, interposed between the processor and the storage devices. Our design effort complies with the stringent limitations existing in these architectures in terms of hardware complexity, available storage and energy consumption. Rather that precluding deliberately harmful programs from producing their effects, our solution is aimed at limiting the spread of programming errors outside the memory scope of the running program. The discussion evaluates the resulting protection environment from a number of salient viewpoints that include the implementation of common protection paradigms, efficiency in the distribution and revocation of access privileges, and the lack of a privileged (kernel) mode. 展开更多
关键词 ACCESS control PROTECTION DOMAIN PROTECTION System Sensor node
下载PDF
无线传感网络拥塞控制中节点选择强制博弈方法 被引量:1
18
作者 陈红 郭海涛 《传感技术学报》 CAS CSCD 北大核心 2024年第1期142-146,共5页
无线传感网络中节点数据流量较大,分布范围较广,节点选择寻优计算复杂,导致浪费大量算力在节点选择上,拥塞控制效果不佳。提出一种无线传感网络拥塞控制中节点选择强制博弈方法,计算单条网络链路传输成本,依据传输数据耗费能量,计算传... 无线传感网络中节点数据流量较大,分布范围较广,节点选择寻优计算复杂,导致浪费大量算力在节点选择上,拥塞控制效果不佳。提出一种无线传感网络拥塞控制中节点选择强制博弈方法,计算单条网络链路传输成本,依据传输数据耗费能量,计算传输节点可用能量比值,在传输变量权重值基础上,求得传输节点实际拥堵指数,完成节点选择。计算网络连接层的数据包丢弃概率,确定网络拥塞程度,汇聚节点数据流建立节点选择强制博弈模型,明确传感网络稳态传输条件,利用流量正态分布算法,在节点选择博弈中做出强制选择。经仿真分析证明:所提方法分组递交率保持在83%以上,丢包数量保持在100 pkt/s之内,网络传输节点端到端的延迟在0.3 s以内。 展开更多
关键词 无线传感网络 网络拥塞控制 强制博弈 网络节点选择 变量权重
下载PDF
Research on the Controllability of Software Networks Based on the Source-Driven Model
19
作者 He Tian Xianwei Meng +2 位作者 Nan Hu Yanchao Wang Tianyi Yang 《Journal of Computer and Communications》 2022年第8期26-40,共15页
The complexity of software system has been increasing with software evolution, which affects the stability of software structure. Most of the existing measurement methods focus on the analysis of the macro-characteris... The complexity of software system has been increasing with software evolution, which affects the stability of software structure. Most of the existing measurement methods focus on the analysis of the macro-characteristics of the network topology, but lacked a certain depth and expansion to explore the nature of the complexity of the software structure, for this purpose, the complex network control theory was applied to the study of software network controllability. Firstly, the Source-Driver (SD) model was established based on the system control theory, the driver node sets were obtained by the minimum input theorem in the control process of software network topology;Then the relationship between the degree and center degree, the relationship between the in-degree and the out-degree of the software network topology were further analyzed owing to the non-uniqueness of the driver node sets;Finally, the values of the four indicators in the software system were compared. Experimental results show that the driver node sets in the software networks are mainly composed of nodes with low degree values, but it does not mean that the nodes whose in-degree values and out-degree values are also low;The action on control nodes and driver nodes are not random, the controllability of the driver nodes is closely related to the in-degree, when selecting the driver node sets, the network topology characteristics should be considered comprehensively, and the nodes with high degree and center degree are the first choice. The results have important guiding significance for the control, maintenance and redesign of software architecture. 展开更多
关键词 Complex Networks Software Networks Driver node Sets Network control
下载PDF
基于NURBS曲面的小麦叶片三维重建
20
作者 徐苗 马娜 《中国农学通报》 2024年第25期140-146,共7页
针对小麦叶片三维可视化不易实现的问题,通过NURBS曲面算法对小麦叶片进行三维重建。实测小麦叶片长度、叶片宽度、茎叶夹角、叶鞘长度、叶鞘直径等具体数据,通过主脉控制点算法计算叶片和叶鞘的主脉控制点信息,根据叶片宽度、叶鞘直径... 针对小麦叶片三维可视化不易实现的问题,通过NURBS曲面算法对小麦叶片进行三维重建。实测小麦叶片长度、叶片宽度、茎叶夹角、叶鞘长度、叶鞘直径等具体数据,通过主脉控制点算法计算叶片和叶鞘的主脉控制点信息,根据叶片宽度、叶鞘直径等信息计算出全部控制点信息,在visual studio中使用OpenGL构建小麦叶片三维模型。本研究算法得出的小麦叶片模型与真实小麦叶片有较高的相似度,较好地体现了叶片的弯曲度,真实地反映了作物叶片的形态信息。基于NURBS曲面的三维重建控制灵活、使用方便、计算简单,在作物的三维建模方面有较好的应用和参考价值。 展开更多
关键词 NURBS曲面算法 小麦叶片 实测数据 控制点计算 节点矢量 三维重建 OPENGL 形态特征
下载PDF
上一页 1 2 61 下一页 到第
使用帮助 返回顶部