Privacy Protection Based Access Control Scheme in Cloud-Based Services

With the rapid development of computer technology, cloud-based services have become a hot topic. They not only provide users with convenience, but also bring many security issues, such as data sharing and privacy issue. In this paper, we present an access control system with privilege separation based on privacy protection(PS-ACS). In the PS-ACS scheme, we divide users into private domain(PRD) and public domain(PUD) logically. In PRD, to achieve read access permission and write access permission, we adopt the Key-Aggregate Encryption(KAE) and the Improved Attribute-based Signature(IABS) respectively. In PUD, we construct a new multi-authority ciphertext policy attribute-based encryption(CP-ABE) scheme with efficient decryption to avoid the issues of single point of failure and complicated key distribution, and design an efficient attribute revocation method for it. The analysis and simulation result show that our scheme is feasible and superior to protect users' privacy in cloud-based services.

基于Web Services的可复用数据访问层的设计与实现

在Web Services的体系结构和关键技术基础上,提出了一个基于Web Services的数据访问服务的数据访问层的架构,并对架构进行了可复用的研究与实现.该架构可以方便地复用于各种已有的系统以及新开发的信息系统.

基于XML Web Service的分布式异构数据透明转换机制

利用 .NET Web Service构建分布式异构应用平台是当今软件设计的一个热点。文章介绍了 .NET框架中基于 Web Service的分布式异构应用平台体系结构及主要的后台工作协议 XML (e Xtensible Markup L anguage,可扩展标识语言 ) ,阐述了利用 XML作为异构数据转换的中介 ,Web Service作为分布式应用的平台来实现分布式异构数据透明转换的机制。

基于Web Services的在线投稿系统的研究与实现

从分布式多层应用系统的设计入手,分析研究了Web Services原理和XML、SOAP、WSDL、ADO.NET等关键技术,从服务器和客户端两方面考虑,设计了在线投稿系统.本系统结构分为数据层、中间层和客户层3层.中间层利用ADO.NET数据访问技术设计实现了Web Services应用层服务器.Web Services的应用解决了系统集成受地域和操作平台限制的问题,提高了系统的模块化和可扩展性.

基于Web Services的数据管理中心设计和实现

目前,在一个系统内,各个基层部门在Internet上已经建立了大量的数据库,但是这些数据库缺乏相互之间的信息共享,形成信息孤岛。提出了一个实现信息共享的方案,不仅可以保证各个数据库之间的数据一致性,而且,引入Web服务中信息资源的发现和查找的概念,使得在建立一个新的数据库时,很方便地就可以利用现有数据库的信息。

基于Web Services的OPC XML-DA客户端的开发

介绍了WebServices和OPCXML-DA技术，提出了基于WebServices技术的OPCXML—DA系统架构，通过示例说明了OPCXML—DA客户端的开发方法并给出了结果演示。

Ensuring Security, Confidentiality and Fine-Grained Data Access Control of Cloud Data Storage Implementation Environment

With the development of cloud computing, the mutual understandability among distributed data access control has become an important issue in the security field of cloud computing. To ensure security, confidentiality and fine-grained data access control of Cloud Data Storage (CDS) environment, we proposed Multi-Agent System (MAS) architecture. This architecture consists of two agents: Cloud Service Provider Agent (CSPA) and Cloud Data Confidentiality Agent (CDConA). CSPA provides a graphical interface to the cloud user that facilitates the access to the services offered by the system. CDConA provides each cloud user by definition and enforcement expressive and flexible access structure as a logic formula over cloud data file attributes. This new access control is named as Formula-Based Cloud Data Access Control (FCDAC). Our proposed FCDAC based on MAS architecture consists of four layers: interface layer, existing access control layer, proposed FCDAC layer and CDS layer as well as four types of entities of Cloud Service Provider (CSP), cloud users, knowledge base and confidentiality policy roles. FCDAC, it’s an access policy determined by our MAS architecture, not by the CSPs. A prototype of our proposed FCDAC scheme is implemented using the Java Agent Development Framework Security (JADE-S). Our results in the practical scenario defined formally in this paper, show the Round Trip Time (RTT) for an agent to travel in our system and measured by the times required for an agent to travel around different number of cloud users before and after implementing FCDAC.

济钢基于Web Services技术的冷轧物流管理系统

随着MES系统(生产执行系统)在济钢冷轧厂的成功上线,对于生产和物流环节的信息及时准确采集提出了更高的要求。相对于传统的手工收集数据,基于Web Services技术无线数据采集系统可以及时准确的采集信息数据,将此系统应用在天车作业、成品交接、仓库盘点中,提高了企业仓库的利用率,减少了企业的资金占用,保证了仓库对进货和库存以及发货等环节的精确控制,降低了管理费用。

A web product data management system based on Simple Object Access Protocol

A new web product data management architecture is presented. The three-tier web architecture and Simple Object Access Protocol (SOAP) are combined to build the web-based product data management (PDM) system which includes three tiers: the user services tier, the business services tier, and the data services tier. The client service component uses the server-side technology, and Extensible Markup Language (XML) web service which uses SOAP as the communication protocol is chosen as the business service component. To illustrate how to build a web-based PDM system using the proposed architecture, a case PDM system which included three logical tires was built. To use the security and central management features of the database, a stored procedure was recommended in the data services tier. The business object was implemented as an XML web service so that client could use standard internet protocols to communicate with the business object from any platform. In order to satisfy users using all sorts of browser, the server-side technology and Microsoft ASP.NET was used to create the dynamic user interface.

无人机自组网中基于优先级和发送概率的低时延MAC协议设计

媒体接入控制(MAC)协议是满足数据传输质量服务需求的一项关键技术,其性能的优劣直接决定了网络的整体运行效率。相较于其他经典MAC协议,基于统计优先级的多址接入(SPMA)协议采用了多优先级接入、信道检测和流量控制等机制,因此它能更好地满足无人机自组网的低时延、区分服务、大规模组网等重要需求。其中,不同优先级阈值是影响该协议性能的关键指标之一,而现有研究中的阈值设置策略会导致无人机自组网吞吐量波动较大的问题。除此之外,在大规模节点组网的情况下,由于特殊的发送机制,该协议面临数据包冲突加剧的问题。针对以上问题,本文提出了一种新的阈值设置方法和低优先级数据概率性接入信道的方法。在大规模节点网络高业务量的情况下,该改进策略根据新的阈值和周期性负载统计的比较结果决定是否延迟或者拒绝相关数据的接入。与此同时,将SPMA协议的多优先级接入机制和排队论基本原理相结合,通过计算设定发送概率对不同低优先级数据进行接入控制。仿真结果表明,所提方法能够使得无人机自组网的吞吐量保持稳定,并为不同类型业务的差异性服务质量(QoS)需求提供良好支持,提高不同优先级数据的首发传输成功率的同时不会带来较大的额外时延损耗,性能优于现有的SPMA协议。

基于Tuscany Das的数据网格访问模型

为给数据网格中分布、异构的数据源提供一个统一的访问服务,提出一种基于开源项目Tuscany Das的编程模型,为客户端提供的主要功能包括数据库的CRUD操作(增加、查询、更新和删除)、调用数据库的存储过程操作和记录集的分页。通过中国地震减灾网格试验床数据网格平台GIS应用验证了该模型的有效性。

虚拟天文台数据访问系统(VO-DAS)任务调度设计与实现

为解决异地、异构、海量天文数据无缝透明地统一访问,中国虚拟天文台(China-VO)研究小组自主设计并开发了一套解决方案——虚拟天文台数据访问系统(VO-DAS)。着重从执行流程、设计模式、Session机制、生命周期、资源销毁、异常处理等模块详细阐述了该系统的任务调度设计。为了验证该系统的可行性和性能,最后描述了多个天文科学范例。

Enhanced Trust Based Access Control for Multi-Cloud Environment

Security is an essential part of the cloud environment.For ensuring the security of the data being communicated to and from the cloud server,a significant parameter called trust was introduced.Trust-based security played a vital role in ensuring that the communication between cloud users and service providers remained unadulterated and authentic.In most cloud-based data distribution environments,emphasis is placed on accepting trusted client users’requests,but the cloud servers’integrity is seldom verified.This paper designs a trust-based access control model based on user and server characteristics in a multi-cloud environment to address this issue.The proposed methodology consists of data encryption using Cyclic Shift Transposition Algorithm and trust-based access control method.In this trust-based access control mechanism framework,trust values are assigned to cloud users using direct trust degrees.The direct trust degree is estimated based on the following metrics:success and failure rate of interactions,service satisfaction index,and dishonesty level.In addition to this,trust values are assigned to cloud servers based on the metrics:server load,service rejection rate,and service access delay.The role-Based Access control policy of each user is modified based on his trust level.If the server fails to meet the minimum trust level,then another suitable server will be selected.The proposed system is found to outperform other existing systems in a multi-cloud environment.

Evaluating spatial accessibility to healthcare services from the lens of emergency hospital visits based on floating car data

Public medical facilities that are closely related to the health of residents have been recognised as one of the most crucial elements in sustainable urban planning.For the sake of social equality of medical services(especially for emergency medical conditions),the spatial distributions of medical resources need to be accurately measured and continuously optimized.This study presents an effective method to examine night emergency hospital visit and analyse its spatiotemporal characteristics using float car data(FCD).By extracting the hospital service areas,the two-step floating catchment area(2SFCA)methodology was improved to calculate hospital accessibility.Then,the balance between hospital accessibility and population density was analysed.In addition,we investigated the relationship between individual hospital choice preferences and hospital level and analysed several factors that affect individual choices.These results help us understand the special requirements and need of emergency hospital travel in cities and identify areas where medical resources are scarce.They can be used as guidance for urban hospital planning and construction.And the approach of hospital access behaviour investigation and the improved 2SFCA method can also provide insights for other activity-based travel behaviour research.

Data management services in the transition of research model: An approach of implementing open access, open data and open science

With the development and popularization of information technology,the global academic exchange model has generally developed towards open access.Scientific activity in the information age requires more data to be opened and shared.From open access to open data and to open science.

打造数据业务链,迎接Mobile Data 2.0时代

在介绍移动数据业务链发展趋势的基础上,从无线接入、分组核心、计费系统、增值应用和服务保障等5个方面着重阐述了移动数据业务链中的5个重要环节。

The Study of MSADQ/CDMA Protocol in Voice/Data Integration Packet Networks

A new packet medium access protocol, namely, minislot signaling access based on distributed queues(MSADQ/CDMA), is proposed in voice and data intergration CDMA networks. The MSADQ protocol is based on distributed queues and collision resolution algorithm. Through proper management of the PN codes, the number of random competition collision reduces greatly, the multiple access interference (MAI) decreases. It has several special access signaling channels to carry the voice and data access request. Each slot is devided into several control minislots (CMSs), in which the Data Terminals (DT) or Voice Terminals (VT) transmit their request. According to the voice and data traffic character, the signaling access structure is proposed. The code assign rules and queue managing rules are also proposed to ensure the QoS requirement of each traffic. Comparisions with other three protocol are developed by simulation, which shows that MSADQ/CDMA protocol occupies less PN codes, but still has very good performance.

工业云服务知识库接入与管理要求标准解读

为解决知识库接入工业云服务的要求与管理规范缺乏统一性的问题,研制GB/T 42406—2023《工业云服务知识库接入与管理要求》国家标准。对标准要点进行解读,介绍了知识库接入流程及资源认证、数据交换、接入测试3方面的接入要求,阐述了知识库检索、调用、维护、统计等管理规范,并对该标准的推广应用作了分析,助力工业云服务建设及产业生态发展。

基于属性加密的DDS访问控制方案

数据分发服务(Data distribution service,DDS)是一种可靠的实时数据通信中间件标准,它是面向基于发布/订阅模型的分布式环境,在各个领域得到了广泛应用,但现有研究涉及DDS安全技术的成果较少,而在实际应用中发布订阅系统存在多种安全威胁。为了建立灵活可靠的安全机制来确保发布订阅信息的安全性,提出一种以数据为中心的访问控制方案。在属性加密的基础上,对访问树结构进行优化处理,结合发布订阅环境增加属性信任机制。之后采用制定属性连接式与授权策略的方式对发布订阅信息进行加密匹配,并建立DDS访问控制模型来控制发布订阅系统内信息的交互,实现数据的安全分发。经过实验验证,该方案既能够应对DDS存在的几种安全威胁,保障发布订阅信息的机密性,也能够实现系统对特定信息的访问控制,并且发布者订阅者不需要共享密钥,减少了密钥管理的开销。

考虑出行起讫点的公交服务可达性评价

考虑公交乘客出行的直观感受,提出基于乘客感知的公交服务可达性评价方法,分析出行起讫点(origin destination,OD)间的公交可达性.基于网格划分采集出行强度、提取出行热点OD,并调用公交路径规划应用程序编程接口(application programming interface,API)获取热点OD的公交出行数据.从乘客感知角度出发,基于理想出行轨迹与实际出行轨迹的时空差异性,构建OD间公交服务可达性评价模型;将公交服务可达性作为公交供给指标,构建公交供需耦合协调性评价模型.以中国兰州市为例进行分析,结果表明,兰州市热点OD的公交服务可达性均值为0.89,属于较高等级;兰州市公交服务可达性空间分布特征受行政区资源集中程度、地形特征、路网密度及天然屏障阻隔等因素影响,在行政区及横纵方向分布不均衡.兰州市热点OD的公交供需协调度均值为0.62,处于初级协调水平;失调OD以轻度失调为主,其空间分布没有明显的空间异质性.研究结果能较全面反映出行OD的公交服务可达性水平及供需耦合协调度水平,识别供需失调OD,并提取失调OD的公交线路,明确公交线网优化方向.