基于区块链的医疗数据流共享

为解决医疗数据流场景存在的数据共享不灵活和医患关系泄漏问题，提出一种基于区块链的医疗数据流共享方案。提出基于密钥生成树的密钥管理策略和密钥搜索策略，用户可根据自身需求使用密钥流加密医疗数据且灵活地共享数据。此外，基于密码学原语提出有效的协议保护区块链上医生和患者的身份信息，实现医患关系隐私保护。安全分析和实验结果分析表明，所提方案可以实现医疗数据流安全和灵活的共享，以及医患关系的隐私保护。     

属性基加密和区块链结合的可信数据访问控制方案

传统的数据存储方式往往采用集中式架构,这种集中式存储架构容易产生信任和安全问题。文章提出一种属性基加密和区块链结合的可信数据访问控制方案,将对称加密算法和属性基加密算法结合,实现了数据所有者对数据的细粒度访问控制,保障了数据所有者的隐私保护权利。同时,文章将区块链技术和分布式存储相结合,区块链上仅存储数据及密文位置的哈希值和访问控制策略等信息,解决了区块链系统的存储瓶颈。实验表明,该方案能有效保护数据所有者的安全和隐私,实现数据的安全共享。     

基于双区块链的医疗记录安全存储与共享方案

在当前的医疗信息化建设中,电子医疗记录的存储与共享给病人带来了隐私泄露的风险,从而造成名誉损害和财产损失。现有的多数保护隐私的医疗记录存储与共享方案使用了中心化的管理节点,容易遭受集中攻击导致单点失效和恶意篡改的威胁。针对这些问题,设计了一个双区块链结构的医疗记录安全存储与共享方案 EMRSBC,其中使用2条联盟链分别用于医疗记录存储与共享。该方案解决了传统单链应用中拓展性差、吞吐量低的问题,将医疗记录的共享与存储分开,利用区块链的去中心化特性以及智能合约的链上代码实现在不可信环境中的访问控制,有效地保护了病人的隐私数据在存储与共享过程中的安全性。     

高效安全的可审计盲混币服务方案

混币服务能够为区块链隐私泄露问题提供解决方案,但仍然面临效率瓶颈和安全风险,为进一步提升混币服务的效率和安全防护能力,提出一种高效安全的可审计盲混币服务方案。该方案首先增加了审计措施,在传统的混币模型基础上,增加审计区块链,以记录用户和混币器行为,实现可追溯和可问责;然后利用椭圆曲线算法构造盲签名,替代现有研究中基于双线性对或RSA的盲签名算法;最后基于可审计的混币模型和新构造的盲签名算法,提出可审计的盲混币服务协议。仿真分析表明,所提方案在提供隐私保护的同时,具有可审计性、抗盗窃攻击等6种安全特性;在同等安全强度下,较对比方案,所提方法能够有效降低计算开销和存储开销。     

基于区块链技术的物联网信息共享安全机制

针对物联网（IoT）信息共享中存在的源数据易被篡改、缺乏信用保障机制以及信息孤岛问题，提出一种基于区块链技术的轻量级物联网信息共享安全框架。该框架采用数据区块链和交易区块链相结合的双链模式:在数据区块链中实现数据的分布式存储和防篡改，并通过改进的实用拜占庭容错（PBFT）机制共识算法，提升数据登记效率；在交易区块链中实现资源和数据交易，并通过基于部分盲签名算法的改进算法，提升交易效率、实现隐私保护。仿真实验部分分别针对抗攻击能力、双链的处理能力和时延进行了验证分析，结果表明该框架具有安全性、有效性和可行性，可应对现实物联网中的大部分场景。     

基于CP-ABE算法的区块链数据访问控制方案

与公有链不同,联盟区块链超级账本Fabric额外集成了成员管理服务机制,能够提供基于通道层面的数据隔离保护。但这种数据隔离保护机制在通道内同步的仍是明文数据,因此存在一定程度的数据泄露风险。另外,基于通道的数据访问控制在一些细粒度隐私保护场景下也不适用。为了解决上述提及的联盟链超级账本中存在的数据隐私安全问题,提出了一种基于CP-ABE算法的区块链数据访问控制方案。结合超级账本中原有的Fabric-CA模块,提出的方案在实现用户级细粒度安全访问控制区块链数据的同时,还能够实现对CP-ABE方案中用户属性密钥的安全分发。对该方案进行的安全分析表明,该方案实现了ABE用户属性私钥安全分发和数据隐私性保护的安全性目标,性能分析部分也说明了所提方案具有良好的可用性。     

基于多层次区块链的医疗数据共享模型

基于区块链的医疗数据共享能够有效地提升医疗数据的可信性,但是面临着链上存储容量有限、缺乏数据隐私保护等问题。针对这些问题,提出一个基于多层次区块链的医疗数据共享模型。对个人医疗数据进行加密后上传到链下的分布式存储中,并将数据索引信息上传到链上,利用多层次区块链协同技术和链上链下混合存储方式提高存储效率;引入差分隐私保护联邦学习中模型参数,提升数据的隐私安全。实验结果表明,相对于以太坊而言,该方案机构存储开销平均下降了60%左右,用户存储开销平均下降30%左右。     

基于区块链的电子病历数据共享方案

以区块链为数据存储平台的电子病历系统是当下研究的热点. 存储在区块链上的数据是不可变的, 这加强了数据的安全性. 提出了一个基于区块链的电子病历数据共享方案, 实现了患者和第三方数据用户在不侵犯患者隐私的前提下共享患者电子病历. 使用私有链与联盟链构造方案的系统模型, 医院服务器上存储患者的电子病历密文, 私有链上存储患者病历密文的哈希值和关键字索引, 联盟链上存储由关键字索引构成的安全索引. 同时利用可搜索加密技术实现了联盟链上对关键字的安全搜索, 运用代理重加密算法实现了第三方数据用户对患者电子病历的共享. 通过数值实验对方案进行了性能评估.     

基于区块链的高速联网收费数据传输应用研究

自高速公路取消省界收费后,跨省车辆通行的数据在多个省份之间存在的分散存储、数据共享流程繁琐和隐私泄露等问题日益凸显。为解决上述问题,该文提出一种基于区块链的高速公路联网收费数据共享方案,基于区块链链接省部两级联网中心,使其共同维护同一个账本。并采取对称加密和非对称加密相结合的方式对链上数据进行处理,以实现数据的安全存储和用户的隐私保护。同时利用智能合约实现跨省结算和数据的实时共享。为提高链上数据的检索效率,基于数据表加密技术实现链上链下数据的安全同步存储和访问。实验结果表明,该方案不仅能够满足高速公路车辆通行数据共享的一致性、安全性、可信性要求,而且其区块链存储和查询TPS完全满足安徽省高速公路联网收费场景下的实际需求。未来随着通行数据不断增长的情况,可采用增加节点的方式提升业务处理能力,性能和功能优势更加突出。     

区块链中可监管的身份隐私保护方案

在账本公开、多方共识情况下确保交易身份的隐私保护是区块链技术面临的主要挑战之一.目前公有链中基于匿名认证和交易混淆的身份隐私保护方案由于缺乏监管又难于在行业应用中推广.借鉴门罗币中的身份隐私保护方案,引入监管方的角色,基于一次性地址加密和零知识证明设计了可监管的交易接收方身份隐私保护方案;结合可链接环签名和可撤销环签名设计了可链接可撤销环签名方案,以实现基于自主混淆的可监管交易发送方身份隐私保护方案.基于上述方案,系统在保护交易方身份隐私的同时,还支持监管方可离线恢复交易参与方的真实身份,从而达到“可控匿名”的监管目的.分析和测试结果表明,方案设计的算法运算时间均为毫秒级,可满足区块链非高频交易场景下的性能需求.     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。