基于动态策略的移动警务终端安全管控系统的设计与实现

对移动警务安全接入平台中的终端设备的安全防护问题进行了研究,提出并研制了一种基于动态策略的移动警务终端安全管控系统,整个系统由客户端、前置服务端和内网服务端组成,前置服务端和内网服务端分别部署在前置区和公安内网,客户端部署在移动终端设备上,确保在移动接入区和公安内网区有效进行物理隔离的前提下,将系统制定的各种安全策略规则下发到客户端执行,规范用户对移动终端的本地软硬件资源和网络资源的使用,实现安全威胁检测、防护及预警,对移动终端用户的违规访问、操作行为进行全面监测和上报,实现终端设备安全和行为的统一管理.     

基于加密SD卡的内网移动终端可信接入方案

为了解决因不可信移动终端非法接入内网导致的信息安全问题,设计了一种基于加密SD卡的内网移动终端可信接入方案。通过可信计算技术,以加密SD卡作为可信硬件设备实现了移动终端设备的可信启动、完整性验证与内网可信接入,并对接入后移动终端与内网的数据交互过程提供了一种加密通信安全存储机制。实验结果表明,该方案在不改变移动终端基本架构的前提下,较为高效地对移动终端进行安全性认证,并在一定程度上保护内网环境的安全。     

一种解决移动终端漫游通信的方法

部署在有线网络环境下的通信处理软件~([1]),与部署在4G和Wifi无线局域网络环境下的移动终端[2]设备相互通信时,存在移动终端设备在重新接入局域网络或发生移动漫游时,移动终端设备的IP地址与通讯录的配置项不一致,导致信息无法互通的问题。本文提出了一种基于网关代理服务的方法,该方法将网关接入代理接入到无线局域网络的各个终端,使终端与外界隔离,有效解决了移动终端设备漫游通信存在的问题。     

一种基于IKE协议的移动VPN安全通信方案

实现移动终端的安全接入、移动通信的安全传输是智能移动终端普及和移动业务扩展的重要环节。以保证移动数据安全交换为目的,针对移动终端接入企业内网所面临的安全问题,提出了一种移动VPN(Virtual PrivateNetwork)通信方案。方案对IPSec VPN的IKE(Internet Key Exchange)协商流程进行了改进,能支持多因子认证和基于角色的访问控制。分析和实验测试证明了方案的安全性和可行性。     

基于改进机器学习算法的物联网终端安全接入方法

为了解决物联网终端接入设备较多时,接入结果可靠性较低的问题,提出基于改进机器学习算法的物联网终端安全接入方法。依据物联网终端设备的标识性和可采集性原则,使用SDK接口提取物联网设备信息;依据该信息对相对应的物联网终端设备流量进行编码和特征提取,生成设备指纹信息;构建物联网终端设备指纹信息库,将物联网终端设备指纹作为输入,使用改进朴素贝叶斯算法优化匹配设备指纹信息库,若匹配成功则允许其接入,反之则拒绝其接入。实验结果表明,该方法P-R曲线的平衡点对应数值分别在0.88和0.83左右,接入结果可靠性较高,可有效实现物联网终端设备负样本匹配,保障设备的安全接入。     

一种基于证书的统一身份管理技术研究

文章提出了一种移动安全接入方案,并针对移动安全接入方案中存在终端登陆、无线VPDN接入、IPSecVPN接入和应用访问等多类用户认证过程,采用基于数字证书的统一身份管理,对用户和智能手机终端进行用户信息标识,可提高移动终端安全接入系统的可管理性和安全性,     

基于802.1x的NAC模型的设计与实现

对目前流行的安全接入控制系统进行分析,发现这些系统仅能解决接入用户身份的问题,并未考虑到用户所使用的终端设备是否符合安全策略要求,存在终端安全方面的安全隐患。为此,提出一个基于802.1x的安全接入控制系统模型,通过添加扩展信息的认证,限制不安全终端的接入,加强安全策略控制,保证大多数终端的安全。     

802.1x协议在桌面安全管理系统中的应用

为了解决各种终端安全以及非法接入等安全问题,桌面安全管理技术应用而生,介绍了802．1x协议及其在桌面安全管理系统终端设备非法接入控制模块中的实现原理,并给出了具体的应用实例。     

华三小贝系列让商业用户“贝”感轻松

无线网络已经成为现代企业必备的IT资源之一,越来越多的企业选择在办公环境中搭建无线设备以方便移动办公设备接入,更多的商贸场所也为消费者提供免费WIFI,但是这带来方便的同时也给CIO们带来更多网络管理的难题。员工是否在办公时间用办公网娱乐聊天?是否有莫名黑客侵入网络?不同部门之间是否能轻易看到彼此的业务机密?怎样才能既保障无线网络的使用便捷性又能使得每个接入终端都可管可控?     

边缘计算场景下的异构终端安全接入技术研究

边缘计算能够对海量终端设备的请求进行实时性处理,但是边缘计算的分布性和实时性等特点也为信息安全的防护带来了更多的局限,身份认证和隐私保护是边缘计算的应用和数据的安全防护需要面临的挑战问题。阐述了当前边缘计算终端安全接入时的信息安全需求,分析了其可能面临的信息安全威胁,提出了一种边缘计算场景下“云-边-端”三层体系的异构终端接入认证机制,方案能够支持海量终端的接入认证请求,并且通过匿名身份的方式保障了终端设备的隐私性。     

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。     

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。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.     

Editorial: Special issue on recent advances in hybrid control theory and applications

正The demands of a rapidly advancing technology for faster and more accurate controllers have always had a strong influence on the progress of automatic control theory.In recent years control problems have been arising with increasing frequency in widely different areas,which cannot be addressed using conventional control techniques.The principal reason for this is the fact that a highly competitive economy is forcing systems to operate in regimes where     

Information for Authors

正Aim The Journals of Zhejiang University-SCIENCE(A/B/C)areedited by the international board of distinguished Chinese andforeign scientists,and are aimed to present the latest devel-opments and achievements in scientific research in China andoverseas to the world’s scientific circles,especially to stimulateand promote academic exchange between Chinese and for-eign scientists everywhere.     

Enhancing a leaf radiative transfer model to estimate concentrations and in vivo specific absorption coefficients of total carotenoids and chlorophylls a and b from single-needle reflectance and transmittance

The relative concentrations of different pigments within a leaf have significant physiological and spectral consequences. Photosynthesis, light use efficiency, mass and energy exchange, and stress response are dependent on relationships among an ensemble of pigments. This ensemble also determines the visible characteristics of a leaf, which can be measured remotely and used to quantify leaf biochemistry and structure. But current remote sensing approaches are limited in their ability to resolve individual pigments. This paper focuses on the incorporation of three pigments—chlorophyll a, chlorophyll b, and total carotenoids—into the LIBERTY leaf radiative transfer model to better understand relationships between leaf biochemical, biophysical, and spectral properties.Pinus ponderosa and Pinus jeffreyi needles were collected from three sites in the California Sierra Nevada. Hemispheric single-leaf visible reflectance and transmittance and concentrations of chlorophylls a and b and total carotenoids of fresh needles were measured. These data were input to the enhanced LIBERTY model to estimate optical and biochemical properties of pine needles. The enhanced model successfully estimated reflectance (RMSE = 0.0255, BIAS = 0.00477, RMS%E = 16.7%), had variable success estimating transmittance (RMSE = 0.0442, BIAS = 0.0294, RMS%E = 181%), and generated very good estimates of carotenoid concentrations (RMSE = 2.48 µg/cm², BIAS = 0.143 µg/cm², RMS%E = 20.4%), good estimates of chlorophyll a concentrations (RMSE = 10.7 µg/cm², BIAS = − 0.992 µg/cm², RMS%E = 21.1%), and fair estimates of chlorophyll b concentrations (RMSE = 7.49 µg/cm², BIAS = − 2.12 µg/cm², RMS%E = 43.7%). Overall root mean squared errors of reflectance, transmittance, and pigment concentration estimates were lower for the three-pigment model than for the single-pigment model. The algorithm to estimate three in vivo specific absorption coefficients is robust, although estimated values are distorted by inconsistencies in model biophysics. The capacity to invert the model from single-leaf reflectance and transmittance was added to the model so it could be coupled with vegetation canopy models to estimate canopy biochemistry from remotely sensed data.     

Mr. Twinn’s bombes

This article discusses the history and design of the special versions of the bombe key-finding machines used by Britain’s Government Code & Cypher School (GC&CS) during World War II to attack the Enigma traffic of the Abwehr (the German military intelligence service). These special bombes were based on the design of their more numerous counterparts used against the traffic of the German armed services, but differed from them in important ways that highlight the adaptability of the British bombe design, and the power and flexibility of the diagonal board. Also discussed are the changes in the Abwehr indicating system that drove the development of these machines, the ingenious ways in which they were used, and some related developments involving the bombes used by the U.S. Navy’s cryptanalytic unit (OP-20-G).