要做好市场调查这项系统工程，首 先必须搞好规划。在整体规划中，市 场调查方案的设计是一个非常重要和 必须的工作。本章主要介绍了用户市 场信息需求分析、调查课题的确定、 调查方案的内容等问题，提供了市场 调查方案的撰写方法和可行性研究方 法

Routing Must choose routes for various origin destination pairs o/d pairs) or for various sessions Datagram routing: route chosen on a packet by packet basis Using datagram routing is an easy way to split paths Virtual circuit routing: route chosen a session by session basis Static routing: route chosen in a prearranged way based on O/D pairs Eytan Modiano

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

第一节科学研究的一般程序 科学研究是一项系统工程,可划分为三个阶段: 准备阶段:文献检索、选择究课题、制订试验方案、 拟定试验计划书等。 实施阶段:试验方案的实施、试验地的管理、试验数据 的收集、试验数据的统计分析等。 总结阶段:试验资料的整理、文献检索、论文撰写、写 总结报告、研究工作的验收、鉴定及推广应用等

这是本课程的第六单元,按照第一、二节和第三、四节课分别设计。 一、学习目标 1、识记概念:课程改革、突变式课程改革和渐变式式课程改革、课程变迁、课程创新和课程运动、课程范式 2、比较详细地了解我国新课改的背景与特点。 3、掌握“课程改革是一项系统工程”的内涵

第一节科学研究的一般程序 科学研究是一项系统工程,可划分为三个阶段: 准备阶段:文献检索、选择研究课题、制订试验方案 、拟定试验计划书等。 实施阶段:试验方案的实施、试验地的管理、试验数 据的收集、试验数据的统计分析等。 总结阶段:试验资料的整理、文献检索、论文撰写、 写总结报告、研究工作的验收、鉴定及推广应用等

Used for analyzing network performance In packet networks, events are random Random packet arrivals Random packet lengths While at the physical layer we were concerned with bit-error-rate, at the network layer we care about delays How long does a packet spend waiting in buffers?

Cyclic Codes a cyclic code is a linear block code where if c is a codeword, so are all cyclic shifts of c E.g., 1000, 110, 101,011 is a cyclic code Cyclic codes can be dealt with in the very same way as all other lbc s Generator and parity check matrix can be found a cyclic code can be completely described by a generator string G All codewords are multiples of the generator string In practice, cyclic codes are often used for error detection(CRc) Used for packet networks When an error is detected by the received, it requests retransmission

accelerations account for non-central forces(drag, thrust, etc. X-axis in zenith, y-axis in frames velocity, and z-axis in transverse directions 8 Free orbit solution where 'A and 'B' are lengths and'a andB are phase angles

Modulation Representing digital signals as analog waveforms Baseband signals Signals whose frequency components are concentrated around zero Passband signals Signals whose frequency components are centered at some frequency fc away from zero Baseband signals can be converted to passband signals through modulation Multiplication by a sinusoid with frequency fc Eytan Modiano