Scheduling transactions in mobile distributed real-time database systems

A DMVOCC-MVDA （distributed multiversion optimistic concurrency control with multiversion dynamic adjustment） protocol was presented to process mobile distributed real-time transaction in mobile broadcast environments. At the mobile hosts, all transactions perform local pre-validation. The local pre-validation process is carried out against the committed transactions at the server in the last broadcast cycle. Transactions that survive in local pre-validation must be submitted to the server for local final validation. The new protocol eliminates conflicts between mobile read-only and mobile update transactions, and resolves data conflicts flexibly by using multiversion dynamic adjustment of serialization order to avoid unnecessary restarts of transactions. Mobile read-only transactions can be committed with no-blocking, and respond time of mobile read-only transactions is greatly shortened. The tolerance of mobile transactions of disconnections from the broadcast channel is increased. In global validation mobile distributed transactions have to do check to ensure distributed serializability in all participants. The simulation results show that the new concurrency control protocol proposed offers better performance than other protocols in terms of miss rate, restart rate, commit rate. Under high work load （think time is ls） the miss rate of DMVOCC-MVDA is only 14.6%, is significantly lower than that of other protocols. The restart rate of DMVOCC-MVDA is only 32.3%, showing that DMVOCC-MVDA can effectively reduce the restart rate of mobile transactions. And the commit rate of DMVOCC-MVDA is up to 61.2%, which is obviously higher than that of other protocols.

Statecharts for Distributed Product Data Management System Modelling

Product data management (PDM) has been accepted as an important tool for the manufacturing industries. In recent years, more and mor e researches have been conducted in the development of PDM. Their research area s include system design, integration of object-oriented technology, data distri bution, collaborative and distributed manufacturing working environment, secur ity, and web-based integration. However, there are limitations on their rese arches. In particular, they cannot cater for PDM in distributed manufacturing e nvironment. This is especially true in South China, where many Hong Kong (HK) ma nufacturers have moved their production plants to different locations in Pearl R iver Delta for cost reduction. However, they retain their main offices in HK. Development of PDM system is inherently complex. Product related data cover prod uct name, product part number (product identification), drawings, material speci fications, dimension requirement, quality specification, test result, log size, production schedules, product data version and date of release, special tooling (e.g. jig and fixture), mould design, project engineering in charge, cost spread sheets, while process data includes engineering release, engineering change info rmation management, and other workflow related to the process information. Accor ding to Cornelissen et al., the contemporary PDM system should contains manageme nt functions in structure, retrieval, release, change, and workflow. In system design, development and implementation, a formal specification is nece ssary. However, there is no formal representation model for PDM system. Theref ore a graphical representation model is constructed to express the various scena rios of interactions between users and the PDM system. Statechart is then used to model the operations of PDM system, Fig.1. Statechart model bridges the curr ent gap between requirements, scenarios, and the initial design specifications o f PDM system. After properly analyzing the PDM system, a new distributed PDM (DPDM) system is proposed. Both graphical representation and statechart models are constructed f or the new DPDM system, Fig.2. New product data of DPDM and new system function s are then investigated to support product information flow in the new distribut ed environment. It is found that statecharts allow formal representations to capture the informa tion and control flows of both PDM and DPDM. In particular, statechart offers a dditional expressive power, when compared to conventional state transition diagr am, in terms of hierarchy, concurrency, history, and timing for DPDM behavioral modeling.

A multi-sensor-based distributed real-time measurement system for glacier deformation

Glacier disasters occur frequently in alpine regions around the world,but the current conventional geological disaster measurement technology cannot be directly used for glacier disaster measurement.Hence,in this study,a distributed multi-sensor measurement system for glacier deformation was established by integrating piezoelectric sensing,coded sensing,attitude sensing technology and wireless communication technology.The traditional Modbus protocol was optimized to solve the problem of data identification confusion of different acquisition nodes.Through indoor wireless transmission,adaptive performance analysis,error measurement experiment and landslide simulation experiment,the performance of the measurement system was analyzed and evaluated.Using unmanned aerial vehicle technology,the reliability and effectiveness of the measurement system were verified on the site of Galongla glacier in southeastern Tibet,China.The results show that the mean absolute percentage errors were only 1.13%and 2.09%for the displacement and temperature,respectively.The distributed glacier deformation real-time measurement system provides a new means for the assessment of the development process of glacier disasters and disaster prevention and mitigation.

Congestion Management Strategies of Real-Time Market

The high penetration of distributed energy resources (DERs) will significantly challenge the power system operation and control due to their stochastic, intermittent, and fluctuation characteristics. This enhances the difficulty of congestion management of power systems in cross-border electricity market among different regions. For handling this, the Real-Time Market is proposed for balancing capacity trading against congestions. Several strategies for Real-Time Market dealing with congestions are proposed. The strategy of two-stage crossborder markets in Day-ahead, Intra-day and Real Time Market are introduced with the congestion constraints complied. Pre-Contingency strategy is proposed as the advance preparation for the future congestion, and In-Day redispatch is used for regulation. Accordingly, the requirements on facilities considering telemetry and remote control in a fast manner are discussed at last.

Design and development of real-time query platform for big data based on hadoop

This paper designs and develops a framework on a distributed computing platform for massive multi-source spatial data using a column-oriented database(HBase).This platform consists of four layers including ETL(extraction transformation loading) tier,data processing tier,data storage tier and data display tier,achieving long-term store,real-time analysis and inquiry for massive data.Finally,a real dataset cluster is simulated,which are made up of 39 nodes including 2 master nodes and 37 data nodes,and performing function tests of data importing module and real-time query module,and performance tests of HDFS's I/O,the MapReduce cluster,batch-loading and real-time query of massive data.The test results indicate that this platform achieves high performance in terms of response time and linear scalability.

IoT-Enabled RFID in Supply Chain Management: A Comprehensive Survey and Future Directions

Radio frequency identification (RFID) has emerged as a pivotal technology in supply chain management (SCM), significantly enhancing its efficiency and effectiveness. When integrated with the internet of things (IoT) to form RFID-IoT, this technology brings transformative advancements to SCM, enabling automated sensing, pervasive computing, and ubiquitous data access across the entire supply chain, from manufacturers and distributors to retailers and consumers. This integration facilitates real-time identification and monitoring of products, enhances various processes, improves logistic tracking, and ensures better product quality management. Despite its promising benefits, the adoption of RFID-IoT in SCM faces several challenges, including technical complexities, data security concerns, and high implementation costs. However, the future potential of RFID-IoT technology remains substantial. It is anticipated that further integration with other emerging technologies, such as block chain and artificial intelligence, will lead to more comprehensive and robust SCM solutions, offering unprecedented levels of transparency, efficiency, and automation in supply chain operations.

Cyber Resilience through Real-Time Threat Analysis in Information Security

This paper examines how cybersecurity is developing and how it relates to more conventional information security. Although information security and cyber security are sometimes used synonymously, this study contends that they are not the same. The concept of cyber security is explored, which goes beyond protecting information resources to include a wider variety of assets, including people [1]. Protecting information assets is the main goal of traditional information security, with consideration to the human element and how people fit into the security process. On the other hand, cyber security adds a new level of complexity, as people might unintentionally contribute to or become targets of cyberattacks. This aspect presents moral questions since it is becoming more widely accepted that society has a duty to protect weaker members of society, including children [1]. The study emphasizes how important cyber security is on a larger scale, with many countries creating plans and laws to counteract cyberattacks. Nevertheless, a lot of these sources frequently neglect to define the differences or the relationship between information security and cyber security [1]. The paper focus on differentiating between cybersecurity and information security on a larger scale. The study also highlights other areas of cybersecurity which includes defending people, social norms, and vital infrastructure from threats that arise from online in addition to information and technology protection. It contends that ethical issues and the human factor are becoming more and more important in protecting assets in the digital age, and that cyber security is a paradigm shift in this regard [1].

Research and Application of Distributed Data Mining Method for Improving Rural Power Grid Enterprises in Production and Operation Status Evaluation

With the reform of rural network enterprise system,the speed of transfer property rights in rural power enterprises is accelerated.The evaluation of the operation and development status of rural power enterprises is directly related to the future development and investment direction of rural power enterprises.At present,the evaluation of the production and operation of rural network enterprises and the development status of power network only relies on the experience of the evaluation personnel,sets the reference index,and forms the evaluation results through artificial scoring.Due to the strong subjective consciousness of the evaluation results,the practical guiding significance is weak.Therefore,distributed data mining method in rural power enterprises status evaluation was proposed which had been applied in many fields,such as food science,economy or chemical industry.The distributed mathematical model was established by using principal component analysis(PCA)and regression analysis.By screening various technical indicators and determining their relevance,the reference value of evaluation results was improved.Combined with statistical program for social sciences(SPSS)data analysis software,the operation status of rural network enterprises was evaluated,and the rationality,effectiveness and economy of the evaluation was verified through comparison with current evaluation results and calculation examples of actual grid operation data.

Reliability Management for Information System

An integrated intelligent management is presented to help organizations manage many heterogeneous resources in their information system. A general architecture of management for information system reliability is proposed, and the architecture from two aspects, process model and hierarchical model, described. Data mining techniques are used in data analysis. A data analysis system applicable to real-time data analysis is developed by improved data mining on the critical processes. The framework of the integrated management for information system reliability based on real-time data mining is illustrated, and the development of integrated and intelligent management of information system discussed.

Study on the Prediction System of Shrimp Field Distribution in the East China Sea Based on Big Data Analysis of Fishing Trajectories

In recent years,China has paid more and more attention to the development of marine economy and the management and protection of fishery resources.The management departments at all levels regulate and manage the fishing behavior of fishing vessels through the data of fishing trajectories.In this paper,the distribution of shrimp farms in the East China Sea is predicted by studying the trajectories and behavior patterns of shrimp boats in the system of fishing trajectories.At the same time,a set of shrimp farm distribution management system based on Back Propagation algorithm is established.It can monitor the trajectories of fishing boats and the distribution of shrimp groups in real time,which effectively improves the work efficiency and management mode of the management department.It also plays a positive role in regulating the behavior of fishing boats at sea.

面向分布式图计算的图划分技术综述

图结构作为表达事物之间复杂关联的数据结构,被广泛使用在多种应用场景中.随着互联网应用的不断发展,数据规模的不断增加,分布式的图计算系统相较于传统单机系统从运算时间、资源调度等各个方面显现出优越的性能.近年来,基于大规模图数据的分布式图计算系统使用需求快速增加,图数据划分技术受到了学术界的广泛关注.通过对分布式图计算系统中的图划分技术的研究,首先介绍了面向分布式图计算的图划分的技术背景,给出当前分布式图计算系统中的图划分相关概念的定义以及相关计算模型的分类体系,报告了分布式图计算模型的发展现状.接着对不同的图划分策略中的具体技术进行介绍,通过在不同策略之间进行分析与比较,总结其在各类分布式图计算系统中的优势与不足.最后就分布式图计算系统中图划分技术的发展现状,讨论了其当前存在的挑战与未来的研究方向.

大数据背景下的高校数字图书馆建设与研究

在当今信息技术飞速发展的背景下,高校数字图书馆正面临着转型的重大机遇与挑战。文章探讨Hadoop在高校数字图书馆中的应用,包括其在数据存储、数据处理和系统可扩展性方面的优势。同时,文章也讨论了通过技术应用与创新、人才培养和跨学科合作来优化图书馆服务的策略。最终,文章旨在为高校数字图书馆如何利用Hadoop技术来提升服务质量和操作效率提供策略建议,帮助图书馆更好地适应数字化时代的需求。

考虑算力需求的港口综合能源系统分布式能源管理

为应对港口数字化、绿色化转型带来的算力需求急剧增长及新能源发电不确定性挑战,提出了一种考虑算力需求的港口综合能源系统分布式能源管理方法,旨在通过能源调度与协同利用,实现港口区域内电力、热能及算力的综合优化,以最大化经济效益。考虑到港口不同数据负荷下的时间延迟约束及余热回收潜力,建立港口数据中心耗能计算模型;以港口微电网运行成本、数据中心运行成本和热力系统运行成本最小化为目标,考虑港口电力、热能等多种能源形式的交互耦合机制与多样负荷需求约束,构建港口综合能源系统能源管理模型;利用基于对偶分解混合整数线性规划的分布式算法进行求解,以获得综合能源系统的最优能源管理方案,协同推进航运业及道路运输业脱碳行动。仿真分析表明,该方法可以提高港口综合能源系统的运行效率,有效应对算力需求的挑战。

Variation of spatio-temporal distribution of on-road vehicle emissions based on real-time RFID data

High-resolution vehicular emissions inventories are important for managing vehicular pollution and improving urban air quality. This study developed a vehicular emission inventory with high spatio-temporal resolution in the main urban area of Chongqing, based on realtime traffic data from 820 RFID detectors covering 454 roads, and the differences in spatiotemporal emission characteristics between inner and outer districts were analysed. The result showed that the daily vehicular emission intensities of CO, hydrocarbons, PM2.5, PM10,and NO_(x) were 30.24, 3.83, 0.18, 0.20, and 8.65 kg/km per day, respectively, in the study area during 2018. The pollutants emission intensities in inner district were higher than those in outer district. Light passenger cars(LPCs) were the main contributors of all-day CO emissions in the inner and outer districts, from which the contributors of NO_(x) emissions were different. Diesel and natural gas buses were major contributors of daytime NO_(x) emissions in inner districts, accounting for 40.40%, but buses and heavy duty trucks(HDTs) were major contributors in outer districts. At nighttime, due to the lifting of truck restrictions and suspension of buses, HDTs become the main NO_(x) contributor in both inner and outer districts,and its three NO_(x) emission peak hours were found, which are different to the peak hours of total NO_(x) emission by all vehicles. Unlike most other cities, bridges and connecting channels are always emission hotspots due to long-time traffic congestion. This knowledge will help fully understand vehicular emissions characteristics and is useful for policymakers to design precise prevention and control measures.

A parallel matching algorithm based on order relation for HLA data distribution management

In distribution simulation based on High-level architecture(HLA),data distribution management(DDM)is one of HLA services for the purpose of filtering the unnecessary data transferring over the network.DDM admits the sending federates and the receiving federates to express their interest using update regions and subscription regions in a multidimensional routing space.There are several matching algorithms to obtain overlap information between the update regions and subscription regions.When the number of regions increase sharply,the matching process is time consuming.However,the existing algorithms is hard to be parallelized to take advantage of the computing capabilities of multi-core processors.To reduce the computational overhead of region matching,we propose a parallel algorithm based on order relation to accelerate the matching process.The new matching algorithm adopts divide-and-conquer approach to divide the regions into multiple region bound sublists,each of which comprises parts of region bounds.To calculate the intersection inside and amongst the region bound sublists,two matching rules are presented.This approach has good performance since it performs region matching on the sublists parallel and does not require unnecessary comparisons within regions in different sublists.Theoretical analysis has been carried out for the proposed algorithm and experimental result shows that the proposed algorithm has better performance than major existing DDM matching algorithms.

Statistically Dual Distributions and Estimation

The reconstruction of a parameter by the measurement of a random variable depending on the parameter is one of the main tasks in statistics. In statistical inference, the concept of a confidence distribution and, correspondingly, confidence density has often been loosely referred to as a distribution function on the parameter space that can represent confidence intervals of all levels for a parameter of interest. In this short note, the notion of statistically dual distributions is discussed. Based on properties of statistically dual distributions, a method for reconstructing the confidence density of a parameter is proposed.

基于边端协作的分布式数据分级管理技术

随着智能应用在嵌入式装备系统中的不断普及与发展,对大数据的有效利用和深度融合提出了更高的要求。然而,嵌入式装备类型多样、大数据多源异构,由于缺乏统一的组织管理,业务应用间存在数据壁垒,并出现了数据孤岛现象,导致大数据利用与开发困难。因此,在嵌入式装备系统中,如何有效组织管理数据是亟待解决的难点。为此,以嵌入式装备系统的数据统一管理和共享利用为导向,基于边侧与端侧协作技术,从数据管理架构、数据分级协同管理方案、数据请求调度策略三个方面,探讨了嵌入式装备系统中分布式数据协作管理技术的可行性,以促进数据到信息、信息到知识、知识到决策的快速转化,同时,通过管与用的紧密结合,推动嵌入式装备系统中数据应用的开发。

融合群体智慧的分布式智能电网高效发展管理策略

针对不同资源禀赋下分布式智能电网建设策略难以精准投资的问题,提出了一种融合群体智慧的分布式智能电网高效发展管理策略。首先,依托海量分布式智能电网发展规划数据,利用Ward凝层聚类,从运行、规划及发展3个方面构建分布式智能电网发展最优指标集;其次,结合指标类型拟合其概率分布函数,确定各指标阈值区间,实现指标的客观打分;然后,构建基于群体智慧的分布式智能电网发展精准投资评估体系,利用指标横纵差异度驱动群体智慧重新赋权,实现分布式智能电网建设策略的合理评估;最后,通过计算发展规划投入产出比形成闭环反馈,实现分布式智能电网高效发展管理。通过对某省10 000组发展规划数据的分析评估,验证了所建体系的合理性。

联合冷却系统的分布式绿色数据中心能量管理

为响应可持续发展的号召,建设绿色数据中心并降低其电力消耗和二氧化碳排放成为亟需解决的问题。建立考虑冷却系统的数据中心模型,将描述数据中心电力成本、带宽成本、碳排放成本和冷却成本的成本函数转化为成本最小化问题,通过有效的工作负载调度和合理启停服务器数量降低数据中心运营成本。由于电力价格和碳排放率随时间变化,难以准确预测,利用李雅普诺夫优化框架的特点提出一种在线控制策略,该策略的优点是仅需知道系统的当前信息。提出一种交替方向乘子法(ADMM),使控制中心可以协调各数据中心之间的工作负载分配(数据中心之间只需交换工作负载决策),可有效降低计算复杂度并保护用户隐私。基于真实数据的仿真计算结果表明,提出的算法可有效降低数据中心的运营成本。

基于Rucio的高能物理网格数据管理的研究和应用

【目的】近年来,高能物理网格数据规模和用户需求产生重大变革,需要研究和应用新兴网格数据管理技术以应对需求变化。【方法】基于新型网格数据管理系统Rucio,利用其高伸缩性、模块化和可扩展性的软件特点,发挥其分布式数据恢复、自适应的数据复制的功能特性,为多个国内主导的国际合作实验设计了面向实验需求的网格数据管理解决方案。【结果】实现了分布式数据统一命名、数据增删改查等基础管理功能、多站点数据副本管理、原始数据分发管理、实验软件数据管理接口嵌入等多种功能,并先后进入了测试应用阶段。【结论】本研究为未来国内主导的国际合作的高能物理实验网格数据管理方案的设计和开发进行了探索和尝试,希望进一步在网格架构上开展深入研究,实现国内实验通用标准的网格数据管理方案。