Real-time Synchronization Method Based on Dual Ring Fieldbus in CNC System

As the popularization of dual ring fieldbus, the optimized dual ring synchronization methods are still in short. The current synchronization methods are generally established in traditional industrial fieldbus, in which transmission is commonly considered in single track, the two-way transmitting cannot take full effect, and would result in unwanted idle load on equipment lines. In stamp-transferring part, the synchronizing algorithm is not properly processed to diminish the latency, so the real-time performance of entire system cannot be ensured. To support the synchronization control of stations in the CNC system, a real-time time synchronization method for dual ring fieldbus in the CNC system is designed in this paper. In this method a synchronizing message transmission scheme based on dual ring architecture and the synchronization algorithm between master and secondary stations are integrated. In the scheme, the clock models of both master and secondary stations are optimized with corresponding modules and the stamp data transmission based on the dual ring fieldbus is devised exclusively, so the transmitting efficiency improves with less idle work. In the algorithm, all the secondary stations can accomplish the consistent state with master station by updating clock discrepancy information in one communication cycle, and it takes the advantage of two-way transmitting and makes the best use of dual ring structure, so the real-time performance of the system can be promoted while retaining the precision of synchronization. To evaluate the performance, the costs of the method and errors during synchronizing are noted and analyzed based on the actual running environment in the industrial fieldbus. The results show that it reduces communication cost and ensures the smoothness of the system with low lag effects under heavy load. The proposed time synchronization method optimizes the architecture of sync message transmission in dual ring fieldbus, and improves the efficiency of time synchronization in the stations of CNC system.

SET-MRTS:An Empirical Experiment Tool for Real-Time Scheduling and Synchronization

In the real-time scheduling theory,schedulability and synchronization analyses are used to evaluate scheduling algorithms and real-time locking protocols,respectively,and the empirical synthesis experiment is one of the major methods to compare the performance of such analyses.However,since many sophisticated techniques have been adopted to improve the analytical accuracy,the implementation of such analyses and experiments is often time-consuming.This paper proposes a schedulability experiment toolkit for multiprocessor real-time systems(SET-MRTS),which provides a framework with infrastructures to implement the schedulability and synchronization analyses and the deployment of empirical synthesis experiments.Besides,with well-designed peripheral components for the input and output,experiments can be conducted easily and flexibly on SET-MRTS.This demonstration further proves the effectiveness of SET-MRTS in both functionality and availability.

Encoding-decoding message for secure communication based on adaptive chaos synchronization

In this paper, based on an adaptive chaos synchronization scheme, two methods of encoding-decoding message for secure communication are proposed. With the first method, message is directly added to the chaotic signal with parameter uncertainty. In the second method, multi-parameter modulation is used to simultaneously transmit more than one digital message （i.e., the multichannel digital communication） through just a single signal, which switches among various chaotic attractors that differ only subtly. In theory, such a treatment increases the difficulty for the intruder to directly intercept the information, and meanwhile the implementation cost decreases significantly. In addition, numerical results show the methods are robust against weak noise, which implies their practicability.

Synchronous Detection of DNA/RNA of Four Shrimp Viruses by Real-time Fluorescence Quantitative RT-PCR

[ Objective] This study aimed to establish a simultaneous detection method of shrimp viruses by real-time fluorescence quantitative RT-PCR, to improve the efficiency of inspection and quarantine. [ Method] A novel real-time fluorescence quantitative RT-PCR assay was established and optimized for simultaneously detecting DNA/RNA of four shrimp viruses （WSSV, IHHNV, TSV and YHV ）. [ Result] The optimized real-time fluorescence quantitative RT-PCR system gener- ated typical amplification curves with high amplification efficiencies （E = 1.06, 1.07, 0.92 and 0.92, respectively）, good hnear relationship （ r = 1 ）, uniform repeatability （ standard deviation = 0.05 - 0.46 ; variation coefficient = 0.26% - 1.62% ） and high sensitivity, exhibiting no significant differences compared with re- al-time fluorescence quantitative PCR （average error of Ct value = 0.04 -0.40; T = 0.53 -2.50; P 〉 0.05 ）. The total detection time was about 1 h. [ Conclusion] The optimized real-time fluorescence quantitative RT-PCR system can be used for rapid detection of WSSV, IHHNV, TSV and YHV.

Half Vector Message Pipelining Optimization of Barrier Synchronization Problems

Communication optimization is very important for imporoving performance of parallel programs A communication optimization method called HVMP(Half Vector Message Ripelining) is presented. In comparison with the widelyused vector message pipelining, HVMP can get better tradeoff between reducing and hiding communication overhead,and eliminate the communication barrier of barrier synchronization problems[1]. For parallel Systems with low bandwidth such as cluster of workstations and barrier synchronization problems with large amount of communication, HVMPmethod can get good performance.

THE DLSTRIBOTED MCU MODEL FOR SYNCHRONOUS REAL-TIME TELETEACHING

Aiming at issues on multimedia communication in synchronous real-time teleteaching (SRT) systems over IP network, a 4-tuple structural mode of multimedia communication is proposed in the paper, and an SRT-oriented distributed MCU model is built according to the mode. Moreover, the mechanism of multicast communication across subnets is discussed. The distributed MCU model has been applied successfully in our interactive synchronous real-time telesteaching system RealClass and has shown good extendibility in operation.

Improvement Design for Distributed Real-Time Stream Processing Systems

In the era of Big Data, typical architecture of distributed real-time stream processing systems is the combination of Flume, Kafka, and Storm. As a kind of distributed message system, Kafka has the characteristics of horizontal scalability and high throughput, which is manly deployed in many areas in order to address the problem of speed mismatch between message producers and consumers. When using Kafka, we need to quickly receive data sent by producers. In addition, we need to send data to consumers quickly. Therefore, the performance of Kafka is of critical importance to the performance of the whole stream processing system. In this paper, we propose the improved design of real-time stream processing systems, and focus on improving the Kafka's data loading process.We use Kafka cat to transfer data from the source to Kafka topic directly, which can reduce the network transmission. We also utilize the memory file system to accelerate the process of data loading, which can address the bottleneck and performance problems caused by disk I/O. Extensive experiments are conducted to evaluate the performance, which show the superiority of our improved design.

Digital communication of two-dimensional messages in a chaotic optical system

The digital communication of two-dimensional messages is investigated when two solid state multi-mode chaotic lasers are employed in a master-slave configuration. By introducing the time derivative of intensity difference between the receiver （carrier） and the transmittal （carrier plus signal）, several signals can be encoded into a single pulse. If one signal contains several binary bits, two-dimensional messages in the form of a matrix can be encoded and transmitted on a single pulse. With these improvements in secure communications using chaotic multi-mode lasers, not only the transmission rate can be increased but also the privacy can be enhanced greatly.

IPC Mechanisms in Satellite Real-Time Microkernel Operating System

One of the most important features of modem minor satellites is to realize autonomous moving. The perfomance of the satellite autonomous computer operating system acting as the control center is of utrnost importance. The recent trend in operating system development is adopting microkernel architecture that holds such advantages as microminiaturization, modularity, portability and extendibility. IPC is the key of microkernel design. Message-based IPC mechanism is generally used in existing microkernel Operating system. It is of consistency, safety and reliability.However, it can not provide efficient support for real-time applications in satellite systems and it only applies to loose coupling multi-processor architecture. In this paper, an improvement solution for existing message-based IPC is proposed at first to obtain real-time performance. Then a new IPC mechanism is designed. It particulary applies to shared memory tight coupling multi-processor architecture.

An On-Line Scheduler over Hard Real-Time Communication System

By thorough research on the prominent periodic and aperiodic scheduling algorithms,anon-line hard real-time scheduler is presented,which is applicable to the scheduling of packets over a link.This scheduler,based on both Rate Monotonic,pinwheel scheduling algorithm Sr and Polling Serverscheduling algorithms,can rapidly judge the schedulability and then automatically generate a bus tablefor the scheduling algorithm to schedule the packets as the periodic packets.The implementation of thescheduler is simple and easy to use,and it is effective for the utilization of bus link.The orderly executionof the bus table can not only guarantee the performance of the hard real time but also avoid the blockageand interruption of the message transmission.So the scheduler perfectly meets the demand of hard real-time communication system on the field bus domain.

Comprehensive and personalized approach is a critical area for developing remote cardiac rehabilitation programs

In the evolving landscape of cardiac rehabilitation(CR),adopting digital technologies,including synchronous/real-time digital interventions and smart applications,has emerged as a transformative approach.These technologies offer realtime health data access,continuous vital sign monitoring,and personalized educational enhanced patient self-management and engagement.Despite their potential benefits,challenges and limitations exist,necessitating careful consideration.Synchronous/real-time digital CR involves remote,two-way audiovisual communication,addressing issues of accessibility and promoting home-based interventions.Smart applications extend beyond traditional healthcare,providing real-time health data and fostering patient empowerment.Wearable devices and mobile apps enable continuous monitoring,tracking of rehabilitation outcomes,and facilitate lifestyle modifications crucial for cardiac health maintenance.As digital CR progresses,ensuring patient access,equitable implementation,and addressing the digital divide becomes paramount.Artificial intelligence holds promise in the early detection of cardiac events and tailoring patient-specific CR programs.However,challenges such as digital literacy,data privacy,and security must be addressed to ensure inclusive implementation.Moreover,the shift toward digital CR raises concerns about cost,safety,and potential depersonalization of therapeutic relationships.A transformative shift towards technologically enabled CR necessitates further research,focusing not only on technological advancements but also on customization to meet diverse patient needs.Overcoming challenges related to cost,safety,data security,and potential depersonalization is crucial for the widespread adoption of digital CR.Future studies should explore integrating moral values into digital therapeutic relationships and ensure that digital CR is accessible,equitable,and seamlessly integrated into routine cardiac care.Theoretical frameworks that accommodate the dynamic quality of real-time monitoring and feedback feature of digital CR interventions should be considered to guide intervention development.

基于气象大数据云平台的政务区数据同步技术研究

随着气象大数据的快速发展和山东数字强省建设的深入推进,气象数据在地方政府的发展和决策制定中发挥着越来越重要的作用。为了满足政府数据应用的需求,提出一种基于气象大数据云平台的高效、安全、可靠的数据同步方案,以实现政务区的数据同步,提升气象数据服务能力和信息化水平。依据气象数据的类型和特点,将其划分为一般结构化数据、特色结构化数据和非结构化数据三类,针对每类数据提出了相应的同步技术方案,构建了针对政务区数据同步的综合解决方案,并以山东省气象数据为例进行了实验分析。结果表明,所提方案具备高度可行性、有效性和安全性,可为政府决策提供强有力的数据支撑。

Joint Algorithm of Message Fragmentation and No-Wait Scheduling for Time-Sensitive Networks

Time-sensitive networks(TSNs)support not only traditional best-effort communications but also deterministic communications,which send each packet at a deterministic time so that the data transmissions of networked control systems can be precisely scheduled to guarantee hard real-time constraints.No-wait scheduling is suitable for such TSNs and generates the schedules of deterministic communications with the minimal network resources so that all of the remaining resources can be used to improve the throughput of best-effort communications.However,due to inappropriate message fragmentation,the realtime performance of no-wait scheduling algorithms is reduced.Therefore,in this paper,joint algorithms of message fragmentation and no-wait scheduling are proposed.First,a specification for the joint problem based on optimization modulo theories is proposed so that off-the-shelf solvers can be used to find optimal solutions.Second,to improve the scalability of our algorithm,the worst-case delay of messages is analyzed,and then,based on the analysis,a heuristic algorithm is proposed to construct low-delay schedules.Finally,we conduct extensive test cases to evaluate our proposed algorithms.The evaluation results indicate that,compared to existing algorithms,the proposed joint algorithm improves schedulability by up to 50%.

Research on message resource optimization in computer supported collaborative design

An adaptive mechanism is presented to reduce bandwidth usage and to optimize the use of computing resources of heterogeneous computer mixes utilized in CSCD to reach the goal of collaborative design in distributed-synchronous mode. The mechanism is realized on a C/S architecture based on operation information sharing. Firstly, messages are aggregated into packets on the client. Secondly, an outgoing-message weight priority queue with traffic adjusting technique is cached on the server. Thirdly, an incoming-message queue is cached on the client. At last, the results of implementing the proposed scheme in a simple collaborative design environment are presented.

Confidentiality-aware message scheduling for security-critical wireless networks

Without considering security, existing message scheduling mechanisms may expose critical messages to malicious threats like confidentiality attacks. Incorporating confidentiality improvement into message scheduling, this paper investigates the problem of scheduling aperiodc messages with time-critical and security-critical requirements. A risk-based security profit model is built to quantify the security quality of messages; and a dynamic programming based approximation algorithm is proposed to schedule aperiodic messages with guaranteed security performance. Experimental results illustrate the efficiency and effectiveness of the proposed algorithm.

移动警务跨域消息提醒服务系统的设计与实现

对移动警务平台双域终端消息无法互达的问题进行了研究,提出了移动警务平台侧跨域互通的即时消息提醒服务系统的设计方案;基于MQTT技术实现移动端消息推送,基于AMQP等移动警务平台跨域边界消息队列同步服务实现平台侧消息跨域同步,基于restful规范设计移动警务平台内面向业务应用的跨域终端消息推送服务接口,为移动警务平台内业务应用统一提供跨域终端消息推送服务;整个系统由消息接口模块、终端档案管理模块、跨区域同步模块、消息匹配审计模块和消息推送模块构成,可实现业务系统不同重要等级消息即时高效、安全合规的跨域终端推送。系统关键性能指标消息丢失率≤0.1‰,接口处理能力(TPS)≥20000。

北斗在电信领域应用的发展思考

北斗卫星导航系统广泛地应用于通信领域的时间同步、融合定位及应急通信等方面,对构建天地一体化的定位、导航、授时及通信(Positioning,Navigation,Timing and Communication,PNTC)服务能力具有重要意义。近年来围绕北斗和新通信技术,兴起了通导融合、北斗+5G及星地一体化相关技术研究。然而,当前研究主要聚焦于融合定位及北斗授时等某个方面,关于北斗在电信领域的系统化研究较少。针对此,文章梳理北斗在电信领域的产品研发、基础设施建设及标准化研究等方面的进展,研究北斗定位、授时及短报文服务在电信行业的应用场景,探讨北斗在电信领域应用的挑战和问题,最后对未来北斗与通信网络的深度融合进行展望。

全国不动产登记数据库同步技术研究

目前,全国不动产登记数据库采用存量数据汇交、增量数据接入、一致性比对等方式,与全国各级不动产登记数据库实现数据同步。为解决存量数据汇交不及时、增量数据接入不规范、一致性比对差异数据补报周期长等难点问题,在深入研究与分析比对报文接入和数据库同步2种技术的基础上,本文探索建立全国不动产登记数据库与地方不动产登记数据库之间的数据库同步技术方法,提出了实时数据同步的设计方案和技术流程,探讨研究了涉及的关键技术,为全国各级不动产登记机构开展的地方不动产登记数据库与全国不动产登记数据库同步工作提供参考借鉴。

The History, Trend, Types, and Mitigation of Distributed Denial of Service Attacks

Over time, the world has transformed digitally and there is total dependence on the internet. Many more gadgets are continuously interconnected in the internet ecosystem. This fact has made the Internet a global information source for every being. Despite all this, attacker knowledge by cybercriminals has advanced and resulted in different attack methodologies on the internet and its data stores. This paper will discuss the origin and significance of Denial of Service (DoS) and Distributed Denial of Service (DDoS). These kinds of attacks remain the most effective methods used by the bad guys to cause substantial damage in terms of operational, reputational, and financial damage to organizations globally. These kinds of attacks have hindered network performance and availability. The victim’s network is flooded with massive illegal traffic hence, denying genuine traffic from passing through for authorized users. The paper will explore detection mechanisms, and mitigation techniques for this network threat.

基于Kafka的跨节点消息队列容灾实践应用

基于高并发、稳定性、生态良好考虑,中移互联网有限公司部门项目引入成熟工具实现Kafka消息的异地节点同步,并采用一种基于滑动时间窗口的同步延迟检测算法实现Kafka消息同步进度的检测,从而很好地实现跨节点同步过程中,消息队列同步延迟的检测。