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1.
We discuss a “binary” algorithm for solving systems of linear equations with integer coefficients. So-called “binary” algorithms differ from ordinary ones in that there is no roundoff error, but only overflow, and the underlying analysis is p-adic analysis rather than conventional real analysis. The advantages of this algorithm are especially apparent when extremely large numbers are involved and no roundoff error can be tolerated.

VLSI implementation of this and other “binary” algorithms is very appealing because of the extreme regularity of the circuits involved.  相似文献   


2.
生物特征识别具有稳定、可靠、不易伪造等优点,已广泛应用于个人身份识别中,随着对家畜疾病防疫和可追溯的需求,利用生物特征识别技术对家畜个体进行识别已成为一种趋势。综述了目前主流的几种生物特征识别技术,比较了不同技术的优缺点,分析了鼻纹识别、视网膜识别、虹膜识别三种技术在大型家畜个体识别中的应用,总结了生物特征识别技术在大型家畜个体识别中应用的趋势。  相似文献   

3.
Boundaries of coexisting attractor basins are a common source of fractal structures in discrete maps. Chaotic attractors in continuous systems of ordinary differentiable equations also have a fractal microstructure. A generation mechanism for self-similar fractal boundaries is proposed, which gives a closer connection between “chaos” and “fractals.” We discuss the role of analyticity, critical points, chaotic forcing, and bistability as some of the elements needed to answer the major, still unresolved question of whether nature is fractal because, or in spite of, the existence of differentiable systems.  相似文献   

4.
In this article, we postulate the possibility of building a four-brain like expert system. For this purpose we have taken ideas from Minsky’s “Society of Mind” some concepts from Brooks and Stein’s “Brains for Bodies” project, and some mechanisms from neurophysiology. In our search for conceptualization of a minimum multi-brain like system oriented to expert systems, we found that: (a) expert systems with blackboard architecture can be seen as primitive topological approaches to multi-brain systems, (b)in our multi-brain like expert systems conception, as in many other expert systems, we feel that we have to impose our external language as their internal language and our external symbols as their internal symbols. These are the kind of entities discussed by philosophers as “What is it like to be a Bat?”. In this context our conception is still a “Batman”. True-cognitive expert systems might be produced in the future if the matters are self constructed internal languages, and its post-hoc knowledge, and (c) in the scope of multi-brain systems, expert systems are not an engineering subject of artificial intelligence (AI) but a substantive subject that goes from philosophical to neurophysiological aspects.  相似文献   

5.
There are two distinct types of MIMD (Multiple Instruction, Multiple Data) computers: the shared memory machine, e.g. Butterfly, and the distributed memory machine, e.g. Hypercubes, Transputer arrays. Typically these utilize different programming models: the shared memory machine has monitors, semaphores and fetch-and-add; whereas the distributed memory machine uses message passing. Moreover there are two popular types of operating systems: a multi-tasking, asynchronous operating system and a crystalline, loosely synchronous operating system.

In this paper I firstly describe the Butterfly, Hypercube and Transputer array MIMD computers, and review monitors, semaphores, fetch-and-add and message passing; then I explain the two types of operating systems and give examples of how they are implemented on these MIMD computers. Next I discuss the advantages and disadvantages of shared memory machines with monitors, semaphores and fetch-and-add, compared to distributed memory machines using message passing, answering questions such as “is one model ‘easier’ to program than the other?” and “which is ‘more efficient‘?”. One may think that a shared memory machine with monitors, semaphores and fetch-and-add is simpler to program and runs faster than a distributed memory machine using message passing but we shall see that this is not necessarily the case. Finally I briefly discuss which type of operating system to use and on which type of computer. This of course depends on the algorithm one wishes to compute.  相似文献   


6.
Biometrics: a tool for information security   总被引:4,自引:0,他引:4  
Establishing identity is becoming critical in our vastly interconnected society. Questions such as "Is she really who she claims to be?," "Is this person authorized to use this facility?," or "Is he in the watchlist posted by the government?" are routinely being posed in a variety of scenarios ranging from issuing a driver's license to gaining entry into a country. The need for reliable user authentication techniques has increased in the wake of heightened concerns about security and rapid advancements in networking, communication, and mobility. Biometrics, described as the science of recognizing an individual based on his or her physical or behavioral traits, is beginning to gain acceptance as a legitimate method for determining an individual's identity. Biometric systems have now been deployed in various commercial, civilian, and forensic applications as a means of establishing identity. In this paper, we provide an overview of biometrics and discuss some of the salient research issues that need to be addressed for making biometric technology an effective tool for providing information security. The primary contribution of this overview includes: 1) examining applications where biometric scan solve issues pertaining to information security; 2) enumerating the fundamental challenges encountered by biometric systems in real-world applications; and 3) discussing solutions to address the problems of scalability and security in large-scale authentication systems.  相似文献   

7.
Biometrics has become an important alternative in user authentication to a system. The Brunei Government has embarked on various e-government projects. Some of these projects embed biometric mechanism for authentication. The acceptance of biometric security services appears to be affected by several factors, some of which may be the personal attitude of the users, influences of normality and context in which it is used. The study focuses on 155 executives from the 10 ministries of Brunei Darussalam to explore the behavioural intent of the executives towards biometrics through their attitudes. The theory of planned behaviour (TPB) was used as a reference framework, to understand the intention of using biometrics. The data analyses through Smart-PLS suggest that government officers’ attitudes towards biometrics is a predictor of behavioural intention, whereas, subjective norms is a predictor of attitude, perceived behavioural control, behavioural intention and behaviour, i.e. the use of the biometric technology. The implications of these findings are discussed and some conclusions are drawn.  相似文献   

8.
Johnson  M.L. 《Computer》2004,37(4):90-92
Biometrics refers to the automatic identification or verification of living persons using their enduring physical or behavioral characteristics. Biometric systems fall into two categories: authentication and identification, with authentication systems being far more common. We discuss about the Biometric system and its use in authentication and identification. We also discuss about the face recognition system and the threat caused on the civil liberties due to illegal modification of the databases in the biometric system.  相似文献   

9.
G-networks with resets   总被引:2,自引:0,他引:2  
Erol  Jean-Michel   《Performance Evaluation》2002,49(1-4):179-191
Gelenbe networks (G-networks) are product form queuing networks which, in addition to ordinary customers, contain unusual entities such as “negative customers” which eliminate normal customers and “triggers” which move other customers from some queue to another. These models have generated much interest in the literature since the early 1990s. The present paper discusses a novel model for a reliable system composed of N unreliable systems, which can hinder or enhance each other’s reliability. Each of the N systems also tests other systems at random; it is able to reset another system if it is itself in working condition and discovers that the other system has failed, so that the global reliability of the system is enhanced. This paper shows how an extension of G-networks that includes novel “reset” customers can be used to model this behavior. We then show that a general G-network model with resets has product form, and prove existence and uniqueness of its solution.  相似文献   

10.
Biometrics is one of the ways for human authentication. Fabrication of biometrics by intruders, limits the accuracy of authentication. The user-specific keys (ie,) pseudo-random numbers give more security for biometric template protection and increase the accuracy of authentication also. The user-specific token or keys can also be fabricated by intruders by any of the prediction methods. To avoid the creation of fake biometric and fake user-specific keys, a device-specific Physical Unclonable Function (PUF) is proposed. In this article, iris authentication is provided by unclonable PUF-based true random numbers to enhance the unique authentication. Nonreversible Message Authentication Codes (MAC) are developed using PUF and Discrete Wavelet Transform features of iris biometrics. Systematically, MAC codes also created with, encryption algorithm. Encryption is additionally providing confidentiality in the individual iris. Experiments are done with CUHK Iris Image Dataset. Proposed Bio-PUF system has significant functional advantages in point of view of the unclonable pseudo-random number from PUF. Experimentally, Avalanche effect, entropy, NCPR, and UACI parameters are analyzed with PUF-based crypt functions. For 75% of matching with the Bio-PUF-MAC codes with enrolment, the accuracy for correct identification is 77.73%.  相似文献   

11.
The operator “min” is one of the most frequently used aggregation operators in fuzzy decision. However, this operator is the softest operator and no allowance is made for any compensation. The “product” and other operators, some of them may be compensatory, are seldom used because of the nonlinearity of the resulting problem. In this paper, an exponential, instead of linear membership function is proposed. The advantages of using exponential membership are two fold. First, the resulting problems can be transformed to linear ones when the “product” and several other nonlinear aggregate operators are used. Secondly, exponential representation is more realistic than the linear ones usually used for some practical applications.  相似文献   

12.
This article first identifies and exactly defines “cookies” and “Web bugs.” the contents (code) of cookies and Web bugs are next examined through several examples. the useful business value of cookies and Web bugs is examined, followed by a discussion of the threats, invasion of privacy, and other issues. Finally, the powerful possibilities through the synchronization of Web bugs and cookies working together (even in Word documents) are examined.  相似文献   

13.
General structure and characteristics of quick response production system   总被引:2,自引:0,他引:2  
The diversification and shorter production cycles urge manufacturers to shift their production systems from “make to stock” to “make to order” or an intermediate production system between them. The present paper deals with a production system developed by some manufacturers to meet requirements in the last decade. The system, which we call “Quick response to orders production system” or in brief “quick response production system (QRPS)”, is characterized by two key factors, i.e., “acceptable response time” and “semifinished product.” An acceptable response time is decided through the explicit or implicit approval of customers beforehand and manufacturers guarantee to ship products within an acceptable response time in a stochastic sense by processing the semifinished product according to customer order. As a result, manufacturers are able to reduce the inventory of finished products, while customers are able to enjoy the diversification of products and a stable supply from manufacturers. The general structure and characteristics of QRPS are discussed primarily from a quantitative point of view and a numerical example is shown to assist in understanding the design and operation of QRPS.  相似文献   

14.
Current approaches to personal identity authentication using a single biometric technology are limited, principally because no single biometric is generally considered both sufficiently accurate and user-acceptable for universal application. Multimodal biometrics can provide a more adaptable solution to the security and convenience requirements of many applications. However, such an approach can also lead to additional complexity in the design and management of authentication systems. Additionally, complex hierarchies of security levels and interacting user/provider requirements demand that authentication systems are adaptive and flexible in configuration. In this paper we consider the integration of multimodal biometrics using intelligent agents to address issues of complexity management. The work reported here is part of a major project designated IAMBIC (Intelligent Agents for Multimodal Biometric Identification and Control), aimed at exploring the application of the intelligent agent metaphor to the field of biometric authentication. The paper provides an introduction to a first-level architecture for such a system, and demonstrates how this architecture can provide a framework for the effective control and management of access to data and systems where issues of privacy, confidentiality and trust are of primary concern. Novel approaches to software agent design and agent implementation strategies required for this architecture are also highlighted. The paper further shows how such a structure can define a fundamental paradigm to support the realisation of universal access in situations where data integrity and confidentiality must be robustly and reliably protected .  相似文献   

15.
为了增强用户身份认证机制的安全性,在传统的口令认证方式的基础上,提出了一种基于模糊逻辑的击键特征用户认证方法。该方法利用模糊逻辑对用户输入口令的键盘特征进行分析鉴别,并结合用户口令进行用户身份认证。该方法有效弥补了传统的口令机制易被攻击的缺点,有一定的实用性。  相似文献   

16.
In a large class of multi-loop control systems, many feedback loops are “closed” through a time-shared digital computer, by means of algorithms which require information from sources which are sampled at a rate which is not synchronized with the sampling of the individual “plants”. This mis-synchronization, coupled with variations in the computer's task load caused by “interrupts”, results in a randomly time-varying delay in the closing of the various feedback loops. Consequently, the dynamics of each controlled “plant” in such a system may be modeled by means of a stochastic delay-differential equation. This paper presents some new research results concerning the sample stability, as opposed to statistical, or ensemble stability, of linear stochastic delay-differential equations.  相似文献   

17.
Biometrics is the measurement of person’s physiological or behavioral characteristics. It enables authentication of a person’s identity using such measurements. Biometric-based authentication is thus becoming increasingly important in computer-based applications because the amount of sensitive data stored in such systems is growing. Particularly challenging is the implementation of biometric-based authentication in embedded computer system applications, because the resources of such systems are scarce. Reliability and performance are two primary requirements to be satisfied in embedded system applications. Single-mode and hard-feature-based biometrics do not offer enough reliability and performance to satisfy such requirements. Multimode biometrics is a primary level of improvement. Soft-biometric features can thus be considered along with hard-biometric features to further improve performance. A combination of soft-computing methods and soft-biometric data can yield more improvements in authentication performance by limiting requirements for memory and processing power. The multi-biometric approach also increases system reliability, since most embedded systems can capture more than one physiological or behavioral characteristic. A multi-biometric platform that combines voiceprint and fingerprint authentication was developed as a reference model to demonstrate the potential of soft-computing methods and soft-biometric data. Hard-computing pattern-matching algorithms were applied to match hard-biometric features. Artificial neural network (ANN) processing was applied to match soft-biometric features. Both hard-computing and soft-computing matching results are inferred by a fuzzy logic engine to perform smart authentication using a decision-fusion paradigm. The embedded implementation was based on a single-chip, floating-point, digital signal processor (DSP) to demonstrate the practical embeddability of such an approach and the improved performance that can be attained despite limited system resources.  相似文献   

18.
AI adoption of the game-theoretic paradigm although motivated and productive, suffers from basic limits for modelling autonomous agents and MA systems. First, we briefly restate game-theory's role for DAI and MAS: the introduction of formal prototypical social situations (“games”); the use of formal and sound notions, a self-interested view of autonomous agents, etc. Then, a number of criticisms, that have an impact on modelling intelligent social/individual action, are examined: the economicist interpretation of rationality; its instrumentalist conception, which leaves implicit the ends of agents' choices; the consequent multiple equilibria allowed by the theory; the context-unboundedness of rationality. Some contributions for a more heterarchic, context-bounded, architecture of rational agent are given, and a goal-based strategy, as distinct from a strictly utilitarian principle of decision-making, is proposed. Troubles of game-theory with multi-agent systems and in particular with modelling “cooperation” are outlined. Finally, some limits inherent in the notion of “incentive engineering” are pointed out.  相似文献   

19.
20.
个体的生物特征的唯一性和“不可伪造性”使得它很适合于身份认证。生物信息本来是不保密的,所以不能象使用口令一样来使用它,否则将不能提高反而会降低系统的安全性。公钥机制(PKI)也被广泛应用于用户身份认证中,但它是基于私钥的安全性的,不可避免地存在冒用私钥的威胁。论文提出一个结合生物技术与PKI技术的认证方式的设计,具体描述了它在Secure-OSCAR中的实现。  相似文献   

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