循环冗余校验码的单片机及CPLD实现

循环冗余码校验(CRC)是一种可靠性很高的串行数据校验方法.介绍循环冗余码校验的基本原理,并分别用单片机和CPLD作了循环冗余码校验的软件实现和硬件实现.包括汇编语言和VHDL语言源程序.     

圆周率的计算及仿真测试探索

结合圆周率(π)的几种近似运算原理和公式,分析计算机程序设计中的几种常用设计思想,结合算法编写源程序,并进行程序测试比较,以探讨圆周率的多种运算可行性及启发、训练编程思维的方法.     

CRC校验中信息段超长软处理解决方案

该文针对通讯用CRC校验中信息段情况提出一种程序处理办法,根据数学理论证明其方法的正确性,最后给出了实际采用的源程序代码。     

基于SATA接口的并行CRC32算法研究

在CRC校验基本原理及传统串行运算的基础上,介绍了一种快速并行CRC32算法,该算法运算简单、易于硬件实现。与SATA协议结合,设计了基于SATA接口的CRC32数据校验处理模块,该模块处理速度快、输出延时小,能够达到SATA接口实时处理的要求。最后,通过Quartus II开发平台及VHDL硬件描述语言,对SATA协议中帧结构传出的数据进行了仿真,验证了此算法的正确性及优越性。     

异或和取模运算的负载均衡算法

引入信息熵对哈希函数的输入值进行随机度测试,实验证明增加异或字段数并划分字段后进行异或运算能提高运算结果的随机测度值.标识字段有很高的位熵值,函数输入值中加入此值能减少负载迁移次数而运算效率与CRC16接近.采用源IP、目的IP、源端口、目的端口、标识字段作为输入值,并划分为8位的比特串进行异或运算,然后再进行取模运算的双哈希算法运算效率较高而且均衡性好,适合于高速网络环境下的入侵检测.     

CRC-16算法及其单片机实现

提出了一种基于单片机实现的CRC并行算法。该算法仅占用系统少量的存储空间,易于实现。CRC校检码通过一系列异或运算获得,算法采用汇编语言编程后由8051 IP核调用,通过Synplify软件对IP核进行综合,最后导入Quartus II软件进行功能仿真。仿真结果表明所提出的CRC算法在特定的时钟频率下可以有效地运行。     

在FPGA中实现高精度快速除法

介绍FPGA中高精度除法运算的实现方法,给出实现高精度除法运算的VHDL源程序;实现了除数为任意八位二进制的除法,其精度可达到小数点后16位.     

CRC校验码软件生成技术原理分析

循环冗余校验(Cyclic Redundancy Check, CRC)具有检错能力强,运算简单,易于直接用硬件数字电路实现的特点。在完善CRC校验码生成原理模型的基础上,研究了信息系统传输带CRC校验码数据包的一般过程,提出了三种计算数据包CRC校验码的技术方法,在ADI公司DSP软件集成开发仿真测试环境中,设计了一组嵌入式程序,生成了符合ITU组织CRC16 ITU-T V.41标准的CRC校验码码表,分析并总结了CRC校验码码表元素的工程含义和应用方法,研究了两种计算数据包CRC校验码工程实现方法的技术特点,并验证了它们的正确性、一致性和有效性。     

Cortex-M3内核浮点型运算的研究与实现

通过分析Cortex-M3内核的结构与浮点型格式,充分利用Cortex-M3内核中的分支预测、单周期乘法、硬件除法等众多功能强大的特性,使用Thumb-2指令集实现了单精度浮点型的加、减、乘、除与比较运算,并给出了加减法运算的流程图和除法运算的源程序.     

循环冗余校验码的单片机及CPLD实现

循环冗余码校验(CRC)是一种可靠性很高的串行数据校验方法。介绍循环冗余码校验的基本原理,并分别用单片机和CPLD作了循环冗余码校验的软件实现和硬件实现。包括汇编语言和VHDL语言源程序。     

Know how,knowledge that and the requirement of conscious intent

The distinction between know how and knowledge that is one that has failed to draw much attention in philosophy, despite its importance in other fields. This distinction is explored and neuropsychological studies are presented that support this distinction. In particular, the dorsal and ventral visual processing streams are examined and shown to process information individually despite lesions to the other processing stream. Studies are also presented that further highlight the idea that the distinction between know how and knowledge that take place in decision-making and in judgements of how to act. These studies also contradict Carr's assessment that a necessary aspect of connecting know how with ability is conscious intent. The idea of a more general functional connection between know how and ability is explored and it is emphasized that this functional connection should include very basic neurobiological functions.     

Explanation in Scientists and Children

In this paper we provide a psychological account of the nature and development of explanation. We propose that an explanation is an account that provides a conceptual framework for a phenomenon that leads to a feeling of understanding in the reader/hearer. The explanatory conceptual framework goes beyond the original phenomenon, integrates diverse aspects of the world, and shows how the original phenomenon follows from the framework. We propose that explanations in everyday life are judged on the criteria of empirical accuracy, scope, consistency, simplicity, and plausibility. We conclude that explanations in science are evaluated by the same criteria, plus those of precision, formalisms, and fruitfulness. We discuss several types of explanation that are used in everyday life – causal/mechanical, functional, and intentional. We present evidence to show that young children produce explanations (often with different content from those of adults) that have the same essential form as those used by adults. We also provide evidence that children use the same evaluation criteria as adults, but may not apply those additional criteria for the evaluation of explanations that are used by scientists.     

Towards a framework for online game adoption

Drawing on Uses and Gratifications theory, this paper proposes and empirically tests an integrated model that depicts the factors that have the potential to impact the behavioral intention to adopt online games. The model is tested with data collected from 308 students in an American university. Overall, the results revealed that the effect of enjoyment was very crucial, and those of social interaction and achievement are moderate, but that of flow of experience did not influence behavioral intention. Results also indicated that visual appeal and escapism are important factors that affect and precede enjoyment.     

On Kronecker products,tensor products and matrix differential calculus

The algebra of the Kronecker products of matrices is recapitulated using a notation that reveals the tensor structures of the matrices. It is claimed that many of the difficulties that are encountered in working with the algebra can be alleviated by paying close attention to the indices that are concealed beneath the conventional matrix notation. The vectorization operations and the commutation transformations that are common in multivariate statistical analysis alter the positional relationship of the matrix elements. These elements correspond to numbers that are liable to be stored in contiguous memory cells of a computer, which should remain undisturbed. It is suggested that, in the absence of an adequate index notation that enables the manipulations to be performed without disturbing the data, even the most clear-headed of computer programmers is liable to perform wholly unnecessary and time-wasting operations that shift data between memory cells.     

Two Projects for Understanding the Mind: A Response to Morris and Richardson

We respond to Morris and Richardson's (1995) claim that Pickering and Chater's (1995) arguments about the lack of a relation between cognitive science and folk psychology are flawed. We note that possible controversies about the appropriate uses for the two terms do not affect our arguments. We then address their claim that computational explanation of knowledge-rich processes has proved possible in the domains of problem solving, scientific discovery, and reasoning. We argue that, in all cases, computational explanation is only possible for aspects of those processes that do not make reference to general knowledge. We conclude that consideration of the issues raised by Morris and Richardson reinforces our original claim that there are two fundamentally distinct projects for understanding the mind, one based on justification, and the other on computational explanation, and that these apply to non-overlapping aspects of mental life.     

Tone mapping to minimize visual sensation distortion considering brightness and local band‐limited contrast

We propose a tone‐mapping algorithm that minimizes the function that represents the visual sensation distortion that occurs after tone mapping. For the function, we consider both brightness and local band‐limited contrast to reduce darkening of images that have high dynamic range when they are displayed with conventional contrast‐based tone mapping using histogram on devices that have low dynamic range. By exploiting human visual characteristics, we simplify the problem and find a closed‐form solution that minimizes the function that represents distortion of visual sensation. In both subjective and objective evaluations, the proposed algorithm achieves a processed image that is most similar to the original image and has the best subjective image quality.     

Assessment of workload and arm position during different work sequences: a study with portable devices on construction workers

It is recognised that work related shoulder pain is overrepresented among construction workers compared to other occupations. Studies have shown that working with hands above shoulder level increases the shoulder load. Most studies have been confined to the laboratory. The present project was carried out to map the muscular engagement and postures of construction workers undertaking ceiling fitting, and to compare the results to those of the laboratory studies. Two ambulatory devices were used, one allowing recording of electromyographic (EMG) signals bilaterally from the trapezius muscle, and the other to record the position of both arms and back by means of measuring the angles between the vertical line and the back and both upper arms. These recordings were performed during 1.5–2 h work sequences. The results show that the work was mostly performed in an upright position, that both arms were used to a similar amount and that the workers for a large proportion of their working time had their upper arms at levels that are considered harmful in view of shoulder load. The EMG data showed that nearly 50% of the work was spent with trapezius activity that exceeded that of the reference contraction used (about 15% of maximal voluntary contraction) and that the time spent in muscular relaxation was 10%. It was concluded that the exposure of construction workers undertaking ceiling fitting meets the criteria formulated on the basis of laboratory experiments with respect to a high risk of acquiring chronic shoulder pain, due to rotator cuff tendinitis.     

Information Security management: A human challenge?

This paper considers to what extent the management of Information Security is a human challenge. It suggests that the human challenge lies in accepting that individuals in the organisation have not only an identity conferred by their role but also a personal and social identity that they bring with them to work. The challenge that faces organisations is to manage this while trying to achieve the optimum configuration of resources in order to meet business objectives. The paper considers the challenges for Information Security from an organisational perspective and develops an argument that builds on research from the fields of management and organisational behaviour. It concludes that the human challenge of Information Security management has largely been neglected and suggests that to address the issue we need to look at the skills needed to change organisational culture, the identity of the Information Security Manager and effective communication between Information Security Managers, end users and Senior Managers.     

Symmetry between the intentionality of minds and machines? The biological plausibility of Dennett’s account

One of the most influential arguments against the claim that computers can think is that while our intentionality is intrinsic, that of computers is derived: it is parasitic on the intentionality of the programmer who designed the computer-program. Daniel Dennett chose a surprising strategy for arguing against this asymmetry: instead of denying that the intentionality of computers is derived, he endeavours to argue that human intentionality is derived too. I intend to examine that biological plausibility of Dennett’s suggestion and show that Dennett’s argument for the claim that human intentionality is derived because it was designed by natural selection is based on the misunderstanding of how natural selection works.