基于ASP的用户身份鉴别

身份鉴别是维护网络安全的首要元素,本文讨论ASP环境下的用户身份鉴别问题,提出基于用户的密码、特征值和物理位置的身份鉴别方法并给出了实现过程。     

基于掌纹的身份鉴别

总结了近年来提出的基于掌纹进行身份鉴别的多种方法.针对身份鉴别中所涉及的几个关键问题,分别介绍了各种方法的核心思想、实现步骤和特点.最后,对基于掌纹的身份鉴别的发展前景进行了展望和分析.     

基于电子钥匙的远程访问VPN身份鉴别方案

文章阐述了远程访问VPN应用中进行身份鉴别的目的.提出了一种基于电子钥匙的应用于远程访问VPN的身份鉴别方案.该方案采用电子钥匙承栽远程访问客户端的鉴别信息,是一种双因素的、双向的身份鉴别方案.该方案能有效对抗拒绝服务攻击,并能在鉴别不同步的情况下,实现鉴别再同步.     

动态交叉认证技术在身份鉴别中的实现

保障信息安全的措施多种多样．身份鉴别技术是重要手段。如何在内部网络中实现严密而灵活的身份鉴别机制．是实现保障整个计算机资源和机构内部网络的信息安全的基础。     

基于Plugin的WWW身份鉴别系统的研究

在B/S体系结构中采用插件(Plugin)技术可以有效地增强浏览器功能.从基于Web 的安全认证出发,研究了浏览器中Plugin 程序的设计方法,提出了在浏览器中采用Plugin技术实现基于USBKey的身份鉴别方案,并结合PKI体系,实现了具有较高安全性的身份鉴别系统.     

一种新的可信网络接入架构ETNA

提出一种基于嵌入式可信终端的可信网络接入架构,为网络安全接入提供新的思路和手段.该架构能够通过嵌入式系统为接入终端构建可信计算平台,通过双向身份鉴别协议实现接入双方的身份鉴别,通过双向非对等评估协议实现双方计算平台环境鉴别与评估.和现有网络接入架构相比,增强了接入的安全性,部署灵活,实用性强.     

基于一次性口令的电子政务系统设计

口令鉴别是一种根据已知事物验证身份的方法,因为价格低廉、容易实现、方便使用等特点而被广泛的采用。但是这种鉴别方式同时也是用户鉴别机制中最容易攻破的形式。而OTP(One Time Password,即一次性口令)系统就是设计用来应付这种被动攻击形式的。本文开发的是一个采用了SSL单向鉴别、多因素身份鉴别技术的基于一次性口令技术的电子政务应用系统。     

做好网络“安检”——深思洛克推出基于USB技术的电子密钥Mikey

网络安全问题,尤其是网络信息交互时出现的身份鉴别、电子签名、数据加密等,已经成为电子商务发展的一个焦点,而我国于今年1月1日开始施行的计算机安全等级制度也将“网络身份鉴别与控制”排在了最高位置。北京深思洛克数据保护中心利用国际最新的 USB 串行通讯技术推出网络身份鉴别、控制产品——Mikey,走在了实现网络信息交互安全保障的前列。     

基于签名鉴别的网络身份认证模型

计算机网络安全问题已经越来越受到人们的重视,而整个网络安全体系又是以有效的身份认证为基础。分析了传统的身份认证技术的缺点,对签名鉴别进行了概述,详细阐述了基于签名鉴别的身份认证技术的基本原理和基本流程,并根据签名鉴别的基本原理,把签名鉴别技术应用到网络身份认证领域,并详细介绍了基于签名鉴别的网络身份认证系统的体系结构和认证原理。     

面向HTTP身份鉴别协议的单点登录透明集成技术研究

针对单点登录技术实施过程中, 采用HTTP身份鉴别协议的已有Web应用系统不能修改、改变的技术难题, 提出了一种无须修改Web应用程序和Web服务器的身份鉴别方式即可实现单点登录的单点登录透明集成技术。该技术通过插入到Web服务器的HTTP请求、响应处理通道中的一个插件, 自动处理与Web服务器交互的HTTP身份鉴别协议数据, 从而在对Web服务器不作改变、对Web应用程序不作修改的情况下, 实现单点登录功能。实际应用和测试结果表明, 该方案实现了预定的功能, 达到了预期的效果。所提方案对单点登录的应用实施非常有帮助。     

Iterative inflow-implicit outflow-explicit finite volume scheme for level-set equations on polyhedron meshes

In this paper, we propose a cell-centered finite volume method for advective and normal flows on polyhedron meshes which is second-order accurate in space and time for smooth solutions. In order to overcome a time restriction caused by CFL condition, an implicit time discretization of inflow fluxes and an explicit time discretization of outflow fluxes are used in an iterative procedure. For an efficient computation, an 1-ring face neighborhood structure is introduced. Since it is limited to access unknown variables in an 1-ring face neighborhood structure, an iterative procedure is proposed to resolve the limitation of assembled linear system. Two types of gradient approximations, an inflow-based gradient and an average-based gradient, are studied and compared from the point of numerical accuracy. Numerical schemes are tested for an advective and a normal flow of level-set functions illustrating a behavior of the proposed method for an implicit tracking of a smooth and a piecewise smooth interface.     

Engineering Methods from Method Requirements Specifications

By analogy with a Software Requirements Specification (SRS), it is argued that a Method Requirements Specification (MRS) should be introduced in method engineering. It shares with the SRS the property of implementation-independence. This means that an MRS must be an instance of an abstract metamodel and not of a technical metamodel like GOPRR (Graph, Object, Property, Relationship, and Role). The MRS is then translated to be an instantiation of a technical metamodel. We develop a representation system for an MRS and describe an automated process for instantiating a technical metamodel with an MRS. This instantiation is used to produce the actual method which is then given to a metaCASE to produce a CASE tool. Thus, we propose a method engineering approach rooted in the MRS.     

A new approach for component’s port modeling in software architecture

The component’s interaction points with the external world play a fundamental role in the specification of an application’s architecture. Current software architecture approaches consider an interaction point as an atomic element in the specification of interconnections, despite the complexity of its structure and the attached behavior. It is not possible in current component models to deal separately with an element of an interaction point when such an element is needed alone for specifying a specific logic. To support such logic and the specification of a wide range of early ideas in the process of elaborating a software system, the Integrated Approach to Software Architecture (IASA) uses an interaction point model which provides facilities to manipulate any structural or behavioral element defining an interaction point. In addition, such facilities represent the fundamental foundation of the native support by IASA of Aspect Oriented Software Architectures (AOSA) specifications.     

Bio-informatic activity modeling for human-artifacts symbiosis under resource boundedness

We investigate a biologically inspired design of an interface agent that is embedded inside human-artifact interactions rather than as an external observer, and has to work as an intelligent associate for a human user/operator in a time-critical situation like in an emergency. First, recent paradigmatic shifts of artifact design principles are discussed from an interdisciplinary viewpoint. Then, after the idea of Clancey’s activity modeling, we discuss the design principles of a situated interface agent. That is, different from the conventional supervisory agent’s task of seeking to optimize an isolated control task, such an agent has to be able to maintain its identity as an organism living within multiple contexts and looking inwards to consider the the nature of memory and perception, and looking outwards to consider the nature of social action with a human operator. Initially, our prior work using such a design principle is presented, and then decision-theoretic formulations of an interface agent’s activities are provided. This work was presented, in part, at the Third International Symposium on Artificial Life and Robotics, Oita, Japan, January 19–21, 1998     

Interactive genetic algorithms with individual’s fuzzy fitness

Interactive genetic algorithms are effective methods to solve an optimization problem with implicit or fuzzy indices, and have been successfully applied to many real-world optimization problems in recent years. In traditional interactive genetic algorithms, many researchers adopt an accurate number to express an individual’s fitness assigned by a user. But it is difficult for this expression to reasonably reflect a user’s fuzzy and gradual cognitive to an individual. We present an interactive genetic algorithm with an individual’s fuzzy fitness in this paper. Firstly, we adopt a fuzzy number described with a Gaussian membership function to express an individual’s fitness. Then, in order to compare different individuals, we generate a fitness interval based on α-cut set, and obtain the probability of individual dominance by use of the probability of interval dominance. Finally, we determine the superior individual in tournament selection with size two based on the probability of individual dominance, and perform the subsequent evolutions. We apply the proposed algorithm to a fashion evolutionary design system, a typical optimization problem with an implicit index, and compare it with two interactive genetic algorithms, i.e., an interactive genetic algorithm with an individual’s accurate fitness and an interactive genetic algorithm with an individual’s interval fitness. The experimental results show that the proposed algorithm is advantageous in alleviating user fatigue and looking for user’s satisfactory individuals.     

Efficient execution of composite Web services exchanging intensional data

Web service technologies provide a standard means of integrating heterogeneous applications distributed over the Internet. Successive compositions of new Web services using pre-existing ones usually create a hierarchical structure of invocations among a large number of Web services. For the efficient execution of these composite Web services, we propose an approach which exploits intensional XML data, i.e. an XML document that contains special elements representing the calls to Web services, in order to delegate the invocations of the external Web services to some relevant nodes. We formalize an invocation plan for composite Web services in which intensional data is used as their parameters and results, and define a cost-based optimization problem to obtain an efficient invocation plan for them. We provide an A∗ heuristic search algorithm to find an optimal invocation plan for a given set of Web services and also present a greedy method of generating an efficient solution in a short time. The experimental results show that the proposed greedy method can find a close-to-optimal solution efficiently and has good scalability for a complex call hierarchy of Web services.     

面向图像集复合质量的压缩采样分配算法

对于一个航拍图像集的压缩感知编码,现有方案只能采用固定的测量分配机制对其中每幅图像进行压缩采样,未考虑图像之间的差异性以及图像集的整体重构质量,因此难以充分利用有限的采样资源。在总的采样资源约束下,如何为航拍图像集中不同图像分配合理的采样率是一个需要解决的问题。首先,根据航拍图像集的通用需求提出了图像集复合质量的评价指标,用以计算图像集的整体重构质量;随后,根据图像集中不同图像的相对复杂度建立了一个图像方差模型,并基于该模型提出了一种图像集的压缩采样分配算法。实验结果表明相比于现有方案,在相同的采样资源约束下,所提算法有效地提升了航拍图像集的整体重构质量。     

Positioning device for outdoor mobile robots using optical sensors and lasers

We propose a novel method for positioning a mobile robot in an outdoor environment using lasers and optical sensors. Position estimation via a noncontact optical method is useful because the information from the wheel odometer and the global positioning system in a mobile robot is unreliable in some situations. Contact optical sensors such as computer mouse are designed to be in contact with a surface and do not function well in strong ambient light conditions. To mitigate the challenges of an outdoor environment, we developed an optical device with a bandpass filter and a pipe to restrict solar light and to detect translation. The use of two devices enables sensing of the mobile robot’s position, including posture. Furthermore, employing a collimated laser beam allows measurements against a surface to be invariable with the distance to the surface. In this paper, we describe motion estimation, device configurations, and several tests for performance evaluation. We also present the experimental positioning results from a vehicle equipped with our optical device on an outdoor path. Finally, we discuss an improvement in postural accuracy by combining an optical device with precise gyroscopes.     

Scale-aware navigation of a low-cost quadrocopter with a monocular camera

We present a complete solution for the visual navigation of a small-scale, low-cost quadrocopter in unknown environments. Our approach relies solely on a monocular camera as the main sensor, and therefore does not need external tracking aids such as GPS or visual markers. Costly computations are carried out on an external laptop that communicates over wireless LAN with the quadrocopter. Our approach consists of three components: a monocular SLAM system, an extended Kalman filter for data fusion, and a PID controller. In this paper, we (1) propose a simple, yet effective method to compensate for large delays in the control loop using an accurate model of the quadrocopter’s flight dynamics, and (2) present a novel, closed-form method to estimate the scale of a monocular SLAM system from additional metric sensors. We extensively evaluated our system in terms of pose estimation accuracy, flight accuracy, and flight agility using an external motion capture system. Furthermore, we compared the convergence and accuracy of our scale estimation method for an ultrasound altimeter and an air pressure sensor with filtering-based approaches. The complete system is available as open-source in ROS. This software can be used directly with a low-cost, off-the-shelf Parrot AR.Drone quadrocopter, and hence serves as an ideal basis for follow-up research projects.     

TGMS: An object-oriented system for programming geometry

TGMS (tiered geometric modelling system) is an experimental system intended to reduce the difficulty and cost of developing new solid modelling applications while preserving investment in an existing, time-tested, solid modeller. The application developer writes programs in the TGMS language, which consists of a base language augmented by data types (classes) for geometry. The base programming language is AML/X, an object-oriented language intended for use in design and manufacturing applications. Solid modelling is done using an interface to GDP (geometric design processor), an existing, production-quality solid modelling system. TGMS shows how a system written in a non-object-oriented language can be used as a base for an object-oriented application programming environment. This paper presents the design of TGMS and discusses important aspects of its implementation. The TGMS language defines classes and methods that provide an interface to functions and data represented in a non-object-oriented language. To implement TGMS, issues related to communication, storage management and consistency were addressed. These, and other, implementation issues are discussed. The paper includes sample programs and a summary of feedback from TGMS users. It concludes that the use of object-oriented programming for geometry has many benefits, and that an object-oriented system can be built on top of a non-object-oriented system at less cost than building the equivalent object-oriented system from scratch.