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1.
The seriousness of computer hacking is not exaggerated, it is far worse than that. The computer hacker has attained the status of myth; society associates all computer crime with a mythical perpetrator that bears no resemblance to reality. This paper will argue that in the early stages of the myth the computer hacker was regarded as a highly skilled but mentally disturbed youth who has an unhealthy association with computers. The new reality of electronic commerce resulted in pressures that culminated in the computer hacker becoming regarded as a dangerous criminal. A thorough analysis of the statistics will demonstrate that the majority of computer intruders are neither dangerous nor highly skilled, and thus nothing like the mythical hacker.  相似文献   
2.
计算机辅助教学是传统教学模式的一个根本性变革 ,在高等教育中发挥的作用越来越明显。探讨了在进行计算机辅助教学课件 (CAI)的开发过程中 ,当前普遍存在的问题及其产生的原因 ,同时 ,初步提出了解决这些问题的方法 ,指出 CAI课件应向网络化、智能化方向发展  相似文献   
3.
通过分析交际教学法和语法教学法自身的特点和各自在英语教学中的优势与局限 ,指出将两者结合应用应是现阶段大学英语教学最理想的教学模式 ,并从教学目的、教学对象和教师自身角度说明了这种结合应用的必要性。在此基础上 ,总结了目前在结合应用实践中发现的问题 ,并提出了相应的解决办法。  相似文献   
4.
Quantifying uncertainty in the biospheric carbon flux for England and Wales   总被引:1,自引:0,他引:1  
Summary.  A crucial issue in the current global warming debate is the effect of vegetation and soils on carbon dioxide (CO2) concentrations in the atmosphere. Vegetation can extract CO2 through photosynthesis, but respiration, decay of soil organic matter and disturbance effects such as fire return it to the atmosphere. The balance of these processes is the net carbon flux. To estimate the biospheric carbon flux for England and Wales, we address the statistical problem of inference for the sum of multiple outputs from a complex deterministic computer code whose input parameters are uncertain. The code is a process model which simulates the carbon dynamics of vegetation and soils, including the amount of carbon that is stored as a result of photosynthesis and the amount that is returned to the atmosphere through respiration. The aggregation of outputs corresponding to multiple sites and types of vegetation in a region gives an estimate of the total carbon flux for that region over a period of time. Expert prior opinions are elicited for marginal uncertainty about the relevant input parameters and for correlations of inputs between sites. A Gaussian process model is used to build emulators of the multiple code outputs and Bayesian uncertainty analysis is then used to propagate uncertainty in the input parameters through to uncertainty on the aggregated output. Numerical results are presented for England and Wales in the year 2000. It is estimated that vegetation and soils in England and Wales constituted a net sink of 7.55 Mt C (1 Mt C = 1012 g of carbon) in 2000, with standard deviation 0.56 Mt C resulting from the sources of uncertainty that are considered.  相似文献   
5.
本文介绍了杭州汽轮机厂计算机集成制造系统HTW-CIMS的总体方案以及开发和应用该系统时遵循的技术路线。  相似文献   
6.
继承了我国传统的直音、反切等方法以及西方学者的拉丁字母式拼音方法,《汉语拼音方案》作为新中国文字改革的一大成果诞生了。从制定到推行与传播,《汉语拼音方案》在具体应用过程中产生了一些问题需要尽快得到解决,以便《汉语拼音方案》能够为构建和谐语言生活发挥更大的促进作用。  相似文献   
7.
高校扩招下工程图学的教学实践与探讨   总被引:1,自引:1,他引:0  
文章分析了高校扩招给工程图学教学带来的困难 ,并实践和探讨了一种在保证教学质量的前提下提高教学效率的现代教学模式  相似文献   
8.
设Z_P={1,2,…,P-1,0},在模P的加法运算下,Z_P是一个群。Z_P上定义n维广义正方体,其顶点集为{(x_1,x_2,…,x_n):x_i∈Z_P.i=1,2,…,n},两个顶点x和y之间有一条棱,当且仅当sum from i=1 to n丨x_i-y_i丨=1 mod(P)。在这个定义下,本文证明了对任意P≥2和n≥2,Z_P中n维广义正方体上存在一个经过所有顶点的哈密顿回路。文中给出了一些例子作为应用。  相似文献   
9.
In electrical engineering, circuit designs are now often optimized via circuit simulation computer models. Typically, many response variables characterize the circuit's performance. Each response is a function of many input variables, including factors that can be set in the engineering design and noise factors representing manufacturing conditions. We describe a modelling approach which is appropriate for the simulator's deterministic input–output relationships. Non-linearities and interactions are identified without explicit assumptions about the functional form. These models lead to predictors to guide the reduction of the ranges of the designable factors in a sequence of experiments. Ultimately, the predictors are used to optimize the engineering design. We also show how a visualization of the fitted relationships facilitates an understanding of the engineering trade-offs between responses. The example used to demonstrate these methods, the design of a buffer circuit, has multiple targets for the responses, representing different trade-offs between the key performance measures.  相似文献   
10.
Identical numerical integration experiments are performed on a CYBER 205 and an IBM 3081 in order to gauge the relative performance of several methods of integration. The methods employed are the general methods of Gauss-Legendre, iterated Gauss-Legendre, Newton-Cotes, Romberg and Monte Carlo as well as three methods, due to Owen, Dutt, and Clark respectively, for integrating the normal density. The bi- and trivariate normal densities and four other functions are integrated; the latter four have integrals expressible in closed form and some of them can be parameterized to exhibit singularities or highly periodic behavior. The various Gauss-Legendre methods tend to be most accurate (when applied to the normal density they are even more accurate than the special purpose methods designed for the normal) and while they are not the fastest, they are at least competitive. In scalar mode the CYBER is about 2-6 times faster than the IBM 3081 and the speed advantage of vectorised to scalar mode ranges from 6 to 15. Large scale econometric problems of the probit type should now be routinely soluble.  相似文献   
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