共查询到20条相似文献,搜索用时 17 毫秒
1.
Cyberattacks are deliberate actions to alter, disrupt, deceive, degrade, or destroy computer systems or networks or the information and/or programs resident in or transiting these systems or networks. The use of cyberattack as an instrument of US policy is rarely discussed but is an important topic to the nation. 相似文献
2.
Gordon Lyon 《Software》1985,15(1):105-117
Although substantial variety exists among small programming environments, common points-of-choice in their design suggest the following structural characterization: real or virtual hardware; message-passing or procedure-calling; static or dynamic binding; horizontal or vertical organization; abstract or concrete structures; fixed or extensible language. Often these dimensions must support a very focused programming idiom, which combined with other requirements such as portability or performance, establishes structural dependencies, precludes features and forces exceptions. The characterization provides a rough framework that is useful in evaluating programming environments. 相似文献
3.
Liu Y. Huang T.S. Faugeras O.D. 《IEEE transactions on pattern analysis and machine intelligence》1990,12(1):28-37
A method for the determination of camera location from two-dimensional (2-D) to three-dimensional (3-D) straight line or point correspondences is presented. With this method, the computations of the rotation matrix and the translation vector of the camera are separable. First, the rotation matrix is found by a linear algorithm using eight or more line correspondences, or by a nonlinear algorithm using three or more line correspondences, where the line correspondences are either given or derived from point correspondences. Then, the translation vector is obtained by solving a set of linear equations based on three or more line correspondences, or two or more point correspondences. Eight 2-D to 3-D line correspondences or six 2-D to 3-D point correspondences are needed for the linear approach; three 2-D to 3-D line or point correspondences for the nonlinear approach. Good results can be obtained in the presence of noise if more than the minimum required number of correspondences are used 相似文献
4.
MengChu Zhou DiCesare F. 《IEEE transactions on systems, man, and cybernetics. Part B, Cybernetics》1996,26(1):157-164
This paper presents Petri net models of buffers and a methodology by which buffers can be included in a system without introducing deadlocks or overflows. The context is automated manufacturing. The buffers and models are classified as random order or order preserved (first-in-first-out or last-in-first-out), single-input-single-output or multiple-input-multiple-output, part type and/or space distinguishable or indistinguishable, and bounded or safe. Theoretical results for the development of Petri net models which include buffer modules are developed. This theory provides the conditions under which the system properties of boundedness, liveness, and reversibility are preserved. The results are illustrated through two manufacturing system examples: a multiple machine and multiple buffer production line and an automatic storage and retrieval system in the context of flexible manufacturing. 相似文献
5.
A series of digital computer programs which facilitate the production and control of acoustic stimuli for hearing assessment and research are described. The package, which is available for PDP 11 computers under RT-11, allows sounds to be digitized, adjusted for amplitude and/or dc offset, edited while in digital form, and output to file or tape. The waveform editor package includes facilities to edit sounds in time--with some sections removed or added with temporal precision of 0.1 msec or better. Two or more sounds may also be combined for stereo or monaural (sound-on-sound) output, or two may be concatenated. Together, the programs permit a wide range of manipulations useful in preparing sound stimuli for use in hearing experiments or in clinical audiometry. 相似文献
6.
大数据时代的到来催生了一门新的学科——数据科学。首先,探讨了数据科学的内涵、发展简史、学科地位及知识体系等基本问题,并提出了专业数据科学与专业中的数据科学之间的区别与联系。其次,分析现阶段数据科学的研究特点,并分别提出了专业数据科学、专业中的数据科学及大数据生态系统中的相对热门话题。接着,探讨了数据科学研究中的10个争议及挑战:思维模式的转变(知识范式还是数据范式)、对数据的认识(主动属性还是被动属性)、对智能的认识(更好的算法还是更多的数据)、主要瓶颈(数据密集型还是计算密集型)、数据准备(数据预处理还是数据加工)、服务质量(精准度还是用户体验)、数据分析(解释性分析还是预测性分析)、算法评价(复杂度还是扩展性)、研究范式(第三范式还是第四范式)、人才培养(数据工程师还是数据科学家)。然后,提出了数据科学研究的10个发展趋势:预测模型及相关分析的重视,模型集成及元分析的兴起,数据在先、模式在后或无模式的出现,数据一致性及现实主义的回归,多副本技术及靠近数据原则的广泛应用,多样化技术及一体化应用并存,简单计算及实用主义占据主导地位,数据产品开发及数据科学的嵌入式应用,专家余及公众数据科学的兴起,数据科学家与人才培养的探讨。最后,结合文中工作,对数据科学研究者给出了几点建议和注意事项。 相似文献
7.
H. Baier 《Structural and Multidisciplinary Optimization》1994,7(3):184-190
Structural optimization problems may be ill-posed or weakly conditioned. Different causes of such ill-conditioning are investigated, which can arise, for example, from the problem statement itself and its probable strong nonconvexity, or the interaction of the optimization algorithm with the discretized physical model. These effects could cause undesirable or incorrect solutions or no meaningful solutions at all. Thus ill-posed or ill-conditioned problems must be treated and assessed carefully. Some approaches to dealing with such problems and possible consequences for the optimal designs are discussed. 相似文献
8.
Bhargava B. Lilien L. Rosenthal A. Winslett M. Sloman M. Dillon T.S. Chang E. Hussain F.K. Nejdl W. Olmedilla D. Kashyap V. 《Intelligent Systems, IEEE》2004,19(5):74-88
Trust - "reliance on the integrity, ability, or character of a person or thing" - is pervasive in social systems. We constantly apply it in interactions between people, organizations, animals, and even artifacts. We use it instinctively and implicitly in closed and static systems, or consciously and explicitly in open or dynamic systems. An epitome for the former case is a small village, where everybody knows everybody, and the villagers instinctively use their knowledge or stereotypes to trust or distrust their neighbors. A big city exemplifies the latter case, where people use explicit rules of behavior in diverse trust relationships. We already use trust in computing systems extensively, although usually subconsciously. The challenge for exploiting trust in computing lies in extending the use of trust-based solutions, first to artificial entities such as software agents or subsystems, then to human users' subconscious choices. 相似文献
9.
研究了外力矩作用下刚体转动动力学系统存在的混沌吸引子类型、数量和特性,分析了5个平衡点的属性。系统状态在5个平衡点邻域沿某方向的收敛和沿某方向的发散,可以形成各种各样的周期吸引子,单核、双核、三核、连体四核、单体四核混沌吸引子。该系统中包含的各类混沌运动形式复杂,吸引子种类繁多。 相似文献
10.
Detecting windows or intervals of when a continuous process is operating in a state of steadiness is useful especially when steady-state models are being used to optimize the process or plant on-line or in real-time. The term steady-state implies that the process is operating around some stable point or within some stationary region where it must be assumed that the accumulation or rate-of-change of material, energy and momentum is statistically insignificant or negligible. This new approach is to assume the null-hypothesis that the process is stationary about its mean subject to independent and identically distributed random error or shocks (white-noise) with the alternative-hypothesis that it is non-stationary with a detectable and deterministic slope, trend, bias or drift. The drift profile would be typical of a time-varying inventory or holdup of material with imbalanced flows or even an unexpected leak indicating that the process signal is not steady. A probability of being steady or at least stationary over the window is computed by performing a residual Student t test using the estimated mean of the process signal without any drift and the estimated standard-deviation of the underlying white-noise driving force. There are essentially two settings or options for the method which are the window-length and the Student t critical value and can be easily tuned for each process signal that are included in the multivariate detection strategy. 相似文献
11.
影响轮胎充放气的因素比较复杂,为了简便、准确地对轮胎进行预设定值充放气,提出一种基于模糊与遗传逼近策略的轮胎预设定值充放气控制方法。该方法把整个充放气过程分成两步:首先根据预设定值和当前胎压与预设定值的差,模糊推理出充放气的时间进行预充放;然后依次遗传前面的充放气速率逐步逼近至预设定值。实验结果表明,在不同的充放气条件下利用该方法均能简便、准确地充放气到预设定值,精度可达±0.04bar,适用于各种自动轮胎充放气设备,且简便、高效、实用。 相似文献
12.
本文提出了模M多维差分变换的图象表示和压缩方法.变换是在对N维图象数组的2~N元分割所产生的2~N元树上进行,其效果是利用了图象的N维数据相关性,使得图象灰度值分布得到了显著的改善,它既适合于二值图象,也适合于多值图象,对于线图、文本以及具有块状或体状的图象或数组尤为有效,变换算法的复杂度非常简单,并且是递归可执行的。 相似文献
13.
Emily S. Patterson David D. Woods Richard I. Cook Marta L. Render 《Cognition, Technology & Work》2007,9(3):155-162
Resilience, the ability to adapt or absorb disturbance, disruption, and change, may be increased by team processes in a complex,
socio-technical system. In particular, collaborative cross-checking is a strategy where at least two individuals or groups
with different perspectives examine the others’ assumptions and/or actions to assess validity or accuracy. With this strategy,
erroneous assessments or actions can be detected quickly enough to mitigate or eliminate negative consequences. In this paper,
we seek to add to the understanding of the elements that are needed in effective cross-checking and the limitations of the
strategy. We define collaborative cross-checking, describe in detail three healthcare incidents where collaborative cross-checks
played a key role, and discuss the implications of emerging patterns. 相似文献
14.
漏洞是在硬件、软件、协议的具体实现或系统安全策略上存在的弱点或缺陷,从而可以让攻击者能够在未授权的情况下访问或破坏系统.为了数据或者应用系统的安全,需要解决操作系统因漏洞可能引起的被攻击问题.解决漏洞安全问题最直接的方式就是给系统或者软件打上补丁,但是打补丁很有可能引起操作系统的故障甚至崩溃.本文阐述了打系统补丁引起的... 相似文献
15.
TMLNN: triple-valued or multiple-valued logic neural network 总被引:2,自引:0,他引:2
Guoyin Wang Hongbao Shi 《Neural Networks, IEEE Transactions on》1998,9(6):1099-1117
We discuss the problem of representing and processing triple-valued or multiple-valued logic knowledge using neural network. A novel neuron model, triple-valued or multiple-valued logic neuron (TMLN), is presented. Each TMLN can represent a triple-valued or multiple-valued logic rule by itself. We will show that there are two TMLNs: TMLN-AND (triple-valued or multiple-valued "logic AND") neuron and TMLN-OR (triple-valued or multiple-valued "logic OR") neuron. Two simplified TMLN models are also presented, and show that a multilayer neural network made up of triple-valued or multiple-valued logic neurons (TMLNN) can implement a triple-valued or multiple-valued logic inference system. The training algorithm for TMLNN is presented and can be shown to converge. In our model, triple-valued or multiple-valued logic rules can be extracted from TMLNN with ease. TMLNN can thus form a base for representing logic knowledge using neural network. 相似文献
16.
创建一个公共类,实现信息系统用户对重要业务数据操作动态的处理,用户修改或删除业务数据时自动保存操作动态,并把修改或删除的数据保存到数据库中,以便恢复或查询历史动态,解决误操作或人为因素导致信息丢失的问题。 相似文献
17.
Copyright protection exists in original works of authorship fixed in any tangible medium of expression. Copyright, however, does not extend to any idea, procedure, process, system, method of operation, concept, principle or discovery, regardless of the form in which it is described, explained, illustrated or embodied. The copyright owner has the exclusive right to do or authorize any of the following: reproduce the copyrighted work; prepare derivative works based on the copyrighted work; distribute copies of the copyrighted work to the public by sale or other transfer of ownership, rental, lease or lending; and perform or display the copyrighted work publicly. A few exceptions or limitations challenge an author's exclusive rights to a work of authorship. The most notable is the “fair use” exception. In addition, copyright laws let libraries or archives reproduce no more than one copy of a work and distribute such a copy only under certain conditions 相似文献
18.
对如何提高交流电流和交流电压变送器的响应速度进行了研究.提出一种基于瞬时值采样原理组成交流电流和交流电压变送器的设计方案.方法是对交流电流变换器或交流电压变换器二次电压的每个周期定点采样保持,然后对采样保持的电压进行比例运算,获得与交流电流变换器一次电流或交流电压变换器一次电压有效值成比例的直流电流或直流电压输出.文中论述了其基本原理,介绍了其电路组成,讨论了其参数设计,并且通过仿真结果证明了其可行性.按该原理组成的交流电流或交流电压变送器不仅可有效地提高响应速度,缩短响应时间,而且结构简单,成本低,精度高,在自动控制和电力系统继电保护中均有一定的实用价值. 相似文献
19.
Synthetic emotion 总被引:6,自引:0,他引:6
《Computer Graphics and Applications, IEEE》2000,20(1):52-53
New research in affective computing-computing that relates to, arises from, or deliberately influences emotion-aims to give computers skills of emotional intelligence. These skills are crucial for learning and for savvy social interaction. For example, recognizing someone's emotional response is key to sensing if what you have just done or said met with approval or disapproval, interest or boredom, confusion or understanding. Computers are increasingly verbal and have formidable computational abilities, but still they cannot see if the graphics they are displaying delight or bore the viewer. The author considers how computers might get better at recognizing emotion 相似文献
20.
Roman S. Ingarden 《Open Systems & Information Dynamics》2001,8(1):55-62
A physical and philosophical discussion of quantum phenomena of coherence, teleportation and open systems is given. We attempt to show that modern physics can give some impulses for new solutions or new tendencies in philosophy. One of the questions is the problem of what is basic in quantum physics: "substances" or "situations", the problem of an observer or two observers at least, of a whole and a part, or distributive or collective sets, of particle-wave complementarity, and of modalities such as possibility, necessity, probability, potentiality, etc. 相似文献