Matlab语言中两个相位解卷绕命令的分析与改进——使用Matlab语言

首先对Matlab语言中能够保持复向量相位连续性的两个解卷绕命令unwrap和phase的使用方法进行比较,指出它们之间的不同之处。然后对其源文件进行深入解读,并举例说明同一信号在这两个命令的作用下所得结果不相符的原因。最后通过修改phase命令的M文件或改变unwrap命令的输入参数使二者的输出达到一致,从而扩大了这两个命令的适用范围。     

DOS命令中*与?的使用

用DOS命令来处理文件时,*与?往往能给我们带来许多方便之处。但是我们只有对它们清楚地了解,才能达到事半功倍的效果。否则,却只能是事与愿违。 *与?是两个特殊的字符,统称“DOS通配符”。其中:*代表任意一个字符串,?代表任意一个字符。这也是这两个通配符之间的主要区别。 *与?能适用于许多DOS命令,如:查询命令DIR、拷贝命令COPY、删除命令DEL等等。下面,我们就以查询命令DIR为例来谈一谈*与?的使用方法:     

DOS下“FOR”命令的妙用

在DOS下查看文本文件时,我们一般使用TYPE或EDIT命令,但要查看多个文件时,这两个命令就不太合适了。这是因为TYPE命令不支持通配符,一次只能查看一个文件;而EDIT虽可带通配符(指     

AutoCAD 2006中的CAL命令

AutoCAD 2006中提供了CAL和QUICKCALC两个计算命令。对利用CAL命令进行计算及绘制图形的方法与技巧进行了深入浅出的详细介绍。     

电路仿真软件Multisim2001（EWB6.0）应用入门（五）

Multisim 2001的仿真功能十分强大,不但能用系统自带的仪器进行仿真,而且还能直接通过菜单命令进行仿真。本文首先通过几个实例介绍一下用菜单命令进行仿真的基本操作方法,最后介绍两个实用电路的仿真实例。一、通过菜单命令对电路进行仿真执行菜单命令Simulate/Analvsis或点击快捷工具栏上的按扭?,会出现包括DC Operating Point、AC     

基于终端行为特征的IRC僵尸网络检测

目前已有的IRC僵尸网络检测算法存在两个问题:需要先验知识以获取匹配模式,无法满足实时处理需求.为解决这两个问题,文中提出了基于昵称和命令序列这两个终端行为特征的IRC僵尸网络检测算法.文中提出三种属性分别从内容、组成和结构三方面互补的刻画两个昵称的相似性,给出两个昵称相似性的量化因子,根据这量化因子生成弹性TRW算法以进行IRC僵尸网络实时检测.文中还在分析僵尸终端登录服务器的行为的基础上,提出了基于命令序列相似性的检测算法.算法评估实验证明两个算法行之有效.最后将这两个算法用于大规模网络环境中实时检测IRC僵尸网络,在两周内检测到162个僵尸频道.     

AutoCAD 2006中的CAL命令

AutoCAD 2006中提供了CAL和QUICKCALC两个计算命令。对利用CAL命令进行计算及绘制图形的方法与技巧进行了深入浅出的详细介绍．     

精通Visual Foxpro6.0中的指针

Visual Foxpro的教学中记录指针位置的移动是一个重点，也是个难点。笔者从记录定位命令和非记录定位命令引起记录指针位置移动这两个方面探讨了记录指针移动教学的策略，并对其作了规律性的总结。     

系统配置的方法与技巧

为了在启动计算机时,使操作系统、计算机硬件以及应用程序按照用户规定的方式进行工作,就必须对计算机进行系统配置.大多数系统配置信息存储在启动盘根目录下的CONFIG.SYS和ⅡUTOEXEC.BAT两个文件中,如果启动盘根目录下没有这两个文件,则计算机将按照操作系统默认的配置运行.MS—DOS启动时,它首先执行CONFIG.SYS文件中的命令.AUTOEXEC.BAT文件是执行CONFIG.SYS文件中的命令之后MS—DOS立刻运行的批处理程序.AUTOEXEC.BAT文件可以含有任何想在系统启动时执行的命令.     

长城0520CH图象的磁盘存取方法及其应用

<正> 一、前言目前,长城0520CH 提供的虚拟图形设备(GRP)是一种功能很强的绘图工具。它提供了两组图象磁盘存取命令,即GET,PUT 与BLOAD,BSAVE,但是这两组命令在进行磁盘存取时,都要在磁盘上建立三个不同的文件,这无疑给磁盘文件管理带来了不便,     

A distributed command governor based on graph colorability theory

In this paper, a distributed command governor (CG) strategy is introduced that, by the use of graph colorability theory, improves the scalability property and the performance of recently introduced distributed noncooperative sequential CG strategies. The latter are characterized by the fact that only 1 agent at a decision time is allowed to update its command, whereas all the others keep applying their previously computed commands. The scalability of these early CG distributed schemes and their performance are limited because the structure of the constraints is not taken into account in their implementation. Here, by exploiting the idea that agents that are not directly coupled by the constraints can simultaneously update their control actions, the agents in the network are grouped into particular subsets (turns). At each time instant, on the basis of a round‐robin policy, all agents belonging to a turn are allowed to update simultaneously their commands, whereas agents in other turns keep applying their previous commands. Then, a turn‐based distributed CG strategy is proposed and its main properties are analyzed. Graph colorability theory is used to determine the minimal number of turns and to distribute each agent in at least a turn. A novel graph colorability problem that allows one to maximize the frequency at which agents can update their commands is proposed and discussed. A final example is presented to illustrate the effectiveness of the proposed strategy.     

Modeling the effects of emphasis and question on fundamental frequency contours of Cantonese utterances

Emphasis and question are two factors that have significant effects on F/sub 0/ contours for various languages, among which tone languages require more careful study because their F/sub 0/ contours show complex interaction between lexical tones and sentence intonation. This paper employs the command-response model for the process of F/sub 0/ contour generation to investigate the effects of these two factors for Cantonese, a typical tone language with nine tones. Analysis shows that the major effect of emphasis is on phrase commands, whereas the polarity and the amplitude of the tone commands in the emphasized part are hardly affected so that the inherent tone command patterns are maintained. In the intonation question, the inherent tone command in the later part of the sentence-final syllable is always substituted by a positive tone command. The particle question, on the other hand, maintains the inherent tone command for the question particle. In both types of questions, a sentence-final phrase command is added or enhanced, and a particular ending tone command is attached, the amplitude of which can indicate the degree of inquisitive intention. By comparison, the effect of emphasis starts from the target part for emphasis but is not confined to it, whereas the effect of question is localized in the sentence-final part and especially concentrated within the ending syllable. Nevertheless, both of them can be represented in the framework of the command-response model, by which F/sub 0/ contours for expressive speech can be generated efficiently.     

A Maple package for improved global mapping forecast

We present a Maple implementation of the well known global approach to time series analysis and some further developments designed to improve the computational efficiency of the forecasting capabilities of the approach. This global approach can be summarized as being a reconstruction of the phase space, based on a time ordered series of data obtained from the system. After that, using the reconstructed vectors, a portion of this space is used to produce a mapping, a polynomial fitting, through a minimization procedure, that represents the system and can be employed to forecast further entries for the series. In the present implementation, we introduce a set of commands, tools, in order to perform all these tasks. For example, the command VecTS deals mainly with the reconstruction of the vector in the phase space. The command GfiTS deals with producing the minimization and the fitting. ForecasTS uses all these and produces the prediction of the next entries. For the non-standard algorithms, we here present two commands: IforecasTS and NiforecasTS that, respectively deal with the one-step and the N$N$-step forecasting. Finally, we introduce two further tools to aid the forecasting. The commands GfiTS and AnalysTS, basically, perform an analysis of the behavior of each portion of a series regarding the settings used on the commands just mentioned above.     

Botnet command and control based on Short Message Service and human mobility

Many serious threats for PCs are spreading to the mobile environment. A mobile botnet, which is a collection of hijacked smartphones under the control of hackers, is one of them. With the quick development of the computing and communication abilities of smartphones, many command and control (C&C) techniques in PC botnets can be easily reused in mobile botnets. However, some particular functions and characteristics of smartphones may provide botmasters with additional means to control their mobile botnets. This paper presents two special C&C mechanisms that leverage Short Message Service and human mobility, respectively. The first one designs a SMS-based flooding algorithm to propagate commands. We theoretically prove that the uniform random graph is the optimal topology for this botnet, and demonstrate its high efficiency and stealth with various simulations. The second one utilizes Bluetooth to transmit botnet commands when hijacked smartphones encounter each other while in motion. We study its performance in a 100 m × 100 m square area with NS-2 simulations, and show that human-mobility characteristics facilitate the command propagation. Even if the infection rate is low, the command can still be effectively propagated provided that the mobility of devices is high. In the end, we propose effective defense strategies against these two special C&C mechanisms.     

Design and stability discussion of an hybrid intelligent controller for an unordinary system

In this paper, the pitch angle control of a lab model helicopter is discussed. This problem has some specific features. As a major unusual feature, it is observed that the steady state control command is completely dependent on the setpoint, and for different setpoints, different steady state control commands are needed to keep the error around zero. Moreover, the system is one with highly oscillating dynamics. In order to solve this control problem, two controllers are designed: an artificial neural network (ANN), whose input is the setpoint, is used to provide steady state control command, and a fuzzy inference system (FIS), whose input is error, is used to provide transient control command. The total control command is the sum of the two aforementioned control commands. It is proven that both ANN and FIS are boundary‐input boundary‐output (BIBO) systems. Using this fact and considering two experimental assumptions, the closed‐loop stability is also proven. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society     

基于NXP5209的AT指令分析与扩展

分析了3GPP定义的AT指令规范,它是由终端发出的被用来控制和执行无线通信模块功能的指令。主CPU使用AT命令驱动通信模块工作。介绍了多路终端适配器的结构,ATCUST模块管理所有具有客户特征的AT指令和URC命令,通过对其中的ATCUST模块的修改实现AT指令的规范化和功能的扩展。     

ARINC661显控指令快速验证方法

针对ARINC661座舱显示系统中显示控制单元在开发阶段验证指令困难的问题,设计了一种解决方法.该方法不需要搭建联试环境,仅在控制指令开发的计算机上即可完成验证.该设计充分利用ARINC661通用内核进行扩展,在通用内核DF加载、指令解析、人机交互、画面渲染等基本功能的基础上,增加显示设备、虚拟UA的管理功能,既保证了辅助组件与实际显示画面的一致性,又能方便地模拟各种机载显示设备.该设计用直观的显示结果来验证控制指令的正确性,使设计人员能够方便快速地测试已开发指令的正确性,从而缩短试验周期,具有良好的适用性、扩展性和可靠性.     

Design and implementation of a linear jerk filter for a computerized numerical controller

The proposed filter is placed in front a buffered digital differential analyzer, and is formed by combining three modified moving average filters. It can export the position commands to ensure smooth and accurate motion of a tool with a linear jerk change. These output commands can guarantee contour accuracy despite the error in the chord height. The acceleration and jerk can be designed simply by specifying the number of registers. The filter can be implemented using three circular buffers to simplify the arithmetic and reduce the computation time. The high precision motion commands are confirmed by installing the filtering algorithm in a digital signal processor of a computerized numerical controller. The radius of the command trajectory does not become distorted at high speed 30 m/min. The commands filtered by the linear jerk filter stabilize the beginning and end of the actual motion of the machine table.     

Event,State, And Process In Arrow Logic

Artificial agents, which are embedded in a virtual world, need to interpret a sequence of commands given to them adequately, considering the temporal structure for each command. In this paper, we start with the semantics of natural language and classify the temporal structures of various eventualities into such aspectual classes as action, process, and event. In order to formalize these temporal structures, we adopt Arrow Logic. This logic specifies the domain for the valuation of a sentence as an arrow. We can connect, or give order to, arrows by defining inter-arrow operations, and can give different views for sentences. Thereafter we formalize the rules of aspectual shifts in situated inference, in the style of a logic programming language. Thus, we not only describe the static representation of temporal features, but also show the dynamic process to deduce how each eventuality is viewed. The rules are applied to the information flow through the sequence of commands; therefore, we consider how the temporal structure of a command affects the succeeding commands.