CSMA/CD and Ethernet Two way cable wsws Ws W CSMA with Collision Detection(CD)capability Nodes able to detect collisions Upon detection of a collision nodes stop transmission Reduce the amount of time wasted on collisions Protocol

Sampling Given a continuous time waveform, can we represent it using discrete samples? How often should we sample? Can we reproduce the original waveform?

第一节概述 6.1 Induction This chapter deals with the magnitude and distribution of lateral pressure between a soil mass and an adjoining earth- retaining structure(挡土结构物,俗称 罐麟的结构型式

McGraw-Hill Higher Education A Division of The McGraup-Hill Companies MODERN ANALYTICAL CHEMISTRY Copyright e 2000 by The McGraw-Hill Companies, Inc. All rights reserved. Printed in the United States of America. Except as permitted under the United States Copyright Act of 976, no part of this publicatio

函数f(x)的单调性与极值是函数的重要性态如图: 曲线弧AB是单增的曲线但从A到C的曲线是向下弯 (或凸)的;从C到B的曲线是向上弯(或凹)的.显然,曲线 的弯曲方向和弯曲方向的转变点对我们研究函数的性 态是十分重要的.这就是下面讨论的凹性与拐点

连续函数是非常重要的一类函数也是函数的一种 重要的性态然界中的许多变量都是连续变化着的,即 在很短的时间内,们的变化都是很微小的这种现象反 映在函数关系上,就是函数的连续性;对函数曲线来说 就是从起点开始到终点都不间断 函数增量(改变量) 设函数y=f(x,当x从x变到x1时,自变量的改变 量(在x处的增量)记为A=xrx2.相应的函数从x 变到(x)时,其函数值之差

试题一及答案 Part I Listening Comprehension (20 minutes) Section A Directions: In this section, you will hear 10 short conversations. At the end of each conversation, question will be asked about what was said. Both the conversation and the question

Directions: In this section, you will hear 10 short conversations. At the end of each conversation, a question will be asked about what was said Both the conversation and the question will be spoken only once. After each question there will be pause. During the pause, you must read the four choices marked), B), C)and D),and

Directions: In this section, you will hear ten short conversations. At the end of each conversation, a question will be asked about what was said. both the conversation

Part IListening Comprehension (20 minutes) Directions: In this section, you will hear ten short conversations. At the end of each conversation, a question will be asked about what was said. Both the conversation