两方参与的隐私保护协同过滤推荐研究

 隐私保护的协同过滤推荐研究致力于在确保高质、高效地产生推荐的同时有效地保护参与方的隐私.在数据分布存储,参与方大于2的情形,已有研究针对其核心任务——对指定项进行评分预测,以可交换的密码系统为主要技术,设计了一个隐私保护计算协议.但该协议不适用于参与方是2的情形.以安全比较计算和安全点积计算为基础安全设施,设计了一个协议,解决参与方是2的情况下对指定项进行评分预测的隐私保护问题,从而解决了隐私保护的两方协同计算问题.预测准确度与数据集中存放一样,证明了协议的正确性,并基于安全多方计算理论和模拟范例,证明其安全性,分析了时间复杂度和通信耗费.     

边缘计算下的联邦学习挑战及进展

<正>近年来，边缘计算和联邦学习技术受到了学术界和工业界的广泛关注。边缘计算充分利用位于边缘设备、边缘节点及边缘服务器上的计算和存储资源，减少对通信资源的消耗，提供了分布式计算和数据处理的能力。联邦学习作为一种分布式的机器学习方法，通过在本地进行模型训练，以达到保护数据隐私安全的目的。边缘计算和联邦学习这两项技术的结合，不仅可以实现边缘端的智能决策，还能减少通信开销，保护用户数据隐私安全。     

AccFed:物联网中基于模型分割的联邦学习加速

随着物联网(IoT)的快速发展,人工智能(AI)与边缘计算(EC)的深度融合形成了边缘智能(Edge AI)。但由于IoT设备计算与通信资源有限,并且这些设备通常具有隐私保护的需求,那么在保护隐私的同时,如何加速Edge AI仍然是一个挑战。联邦学习(FL)作为一种新兴的分布式学习范式,在隐私保护和提升模型性能等方面,具有巨大的潜力,但是通信及本地训练效率低。为了解决上述难题,该文提出一种FL加速框架AccFed。首先,根据网络状态的不同,提出一种基于模型分割的端边云协同训练算法,加速FL本地训练;然后,设计一种多轮迭代再聚合的模型聚合算法,加速FL聚合;最后实验结果表明,AccFed在训练精度、收敛速度、训练时间等方面均优于对照组。     

边缘算法的隐私保护在配网故障诊断系统的应用研究

信息的隐私保护应用随着创新、知识型和智力资源交互业务的展开越发重要,电力物联网平台、配网故障诊断系统的隐私保护,以及海量电力系统隐私数据的领域也面临着攻击和渗透风险、网络知识产权保护和数据隐私保护的问题。本文深入研究了边缘计算算法的隐私保护技术在基于人工智能与边缘计算的配网故障诊断系统的应用,探索配网故障诊断系统的隐私数据信息保护的研究方向。     

基于安全多方计算的两方推理

数字基础设施的发展加速了个人隐私数据在机器学习中的应用。随着机器学习即服务的市场规模逐步扩大，服务提供商和用户在双向获利的同时也面临着严重的隐私泄露风险。因此，安全推理作为隐私保护机器学习的一个分支，成为科学界和工业界的研究热点。安全多方计算是安全推理最重要的密码学工具。从机器学习推理中潜在的隐私问题出发，引入安全多方计算技术，进一步对基于安全多方计算实现的安全推理框架进行分析研究，重点分析和评估了业界先进且实用的技术框架。最后进行了总结与展望，给出了隐私保护机器学习及安全推理的未来发展的思考与建议。     

基于同态加密的高效安全联邦学习聚合框架

为了解决联邦学习数据安全以及加密后通信开销大等问题，提出了一种基于同态加密的高效安全联邦聚合框架。在联邦学习过程中，用户数据的隐私安全问题亟须解决，然而在训练过程中采用加密方案带来的计算和通信开销又会影响训练效率。在既要保护数据安全又要保证训练效率的情况下，首先，采用Top-K梯度选择方法对模型梯度进行筛选，减少了需要上传的梯度数量，提出适合多边缘节点的候选量化协议和安全候选索引合并算法，进一步降低通信开销、加速同态加密计算。其次，由于神经网络每层模型参数具有高斯分布的特性，对选择的模型梯度进行裁剪量化，并采用梯度无符号量化协议以加速同态加密计算。最后，实验结果表明，在联邦学习的场景下，所提框架既保证了数据隐私安全，又具有较高的准确率和高效的性能。     

工信部:加快推动边缘计算等产业热点发展

<正>近日,2017边缘计算产业峰会在北京召开。工业和信息化部信息化和软件服务业司司长谢少锋出席会议并致辞。边缘计算是工业互联网的重要技术支撑。作为新型的数据计算架构和组织形态,边缘计算扩展了网络计算的范畴,将计算从云中心扩展到了网络边缘,为用户就近提供智能服务。在制造业数字化、网络化、智能化转型过程中,边缘计算可以满足用户在敏捷连接、实时计算、数据反馈、应用智能、安全与隐私保护等方面的关键     

基于边缘计算的物联网数据安全处理模型

为提升现有物联网数据处理的安全性,设计基于边缘计算的物联网数据安全处理模型.构建基于边缘计算的物联网应用模型,在此模型中先后采用物联网数据消冗方法和差分隐私保护算法,去除重复的数据获取质量较好的数据后,对物联网数据进行隐私保护,实现基于边缘计算的物联网数据安全处理.经过测试,所构建模型的隐私保护预算值为0.6、决策树深...     

云、边缘和雾计算安全性研究综述

随着云计算技术在学术界与工业界的快速发展和广泛应用，云计算领域中的信息安全和隐私问题成为当前研究的热点。从云计算到边缘计算再到雾计算，不同的计算范式形成各自独特的计算生态系统，这些系统具有不同体系结构、信息存储和处理能力。由于不同的计算生态系统具有一定的异质性，使得多样性计算在信息安全和隐私保护方面仍面临着诸多挑战性的问题。介绍了云、边缘和雾计算3种范式的背景知识以及它们之间的相似性与差异性，3种范式各自在信息安全和隐私保护方面的相关技术及其特征；综述了3种范式在信息安全以及隐私威胁方面所面临的挑战，总结了不同的安全部署与隐私机制以解决此类挑战。确定了信息安全与隐私机制的部署缺陷是由多样性计算的异质性所导致，融合不同的信息安全部署技术可以进一步加强信息的安全性与隐私性。     

算力时代融合边缘云建设思路探讨

随着算力网络的发展,融合边缘云需求进一步加强,建设强大的融合边缘云服务,不仅可以满足各类客户需求,还可以增强边缘云市场竞争力,实现云网融合和云边协同发展,落实国家数字经济战略。本文通过分析融合边缘云的需求,提出将计算、存储、CDN、安全和AI等能力融合到边缘云的思路,通过复用现有资源池带宽和基础设施资源,根据实际需求和应用场景分级分类规划布局,统一架构并按需进行模块化建设等方案举措,满足客户敏捷连接、实时业务、数据优化、应用智能、安全和隐私保护等多种关键需求。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.