一、设计应掌握的基础资料 进行活性污泥系统的工艺计算和设计时，首先应比较充分地掌握与废水、污泥有关的原始资料并确定 设计的基础数据，主要有： ①废水的水量、水质及其变化规律； ②对处理后出水的水质要求； ③对处理中产生的污泥的处理要求； ⎯⎯以上属于设计所需要的原始资料

Outline Network Layer and Internetworking The TCP/IP protocol suit ATM MPLS

Optimal Routing View routing as a “global” optimization problem Assumptions: – The cost of using a link is a function of the flow on that link

FLOW CONTROL QuickTime™ and a GIF decompressor are needed to see this picture. QuickTime™ and a Photo - JPEG decompressor are needed to see this picture. LIDS Flow control: end-to-end mechanism for regulating traffic between source and destination

Service times M/G/1 General independent Poisson arrivals at rate λ Service time has arbitrary distribution with given E[X] and E[X2] – Service times are independent and identically

Carrier Sense Multiple Access (CSMA) In certain situations nodes can hear each other by listening to the channel “Carrier Sensing” CSMA: Polite version of Aloha

An interesting property of an M/M/1 queue, which greatly simplifies combining these queues into a network, is the surprising fact that the output of an M/M/1 queue with arrival rate λ is a Poisson process of rate

When the receiver detects errors in a packet, how does it let the transmitter know to re-send the corresponding packet? Systems which automatically request the retransmission of missing

Queueing Systems Used for analyzing network performance In packet networks, events are random Random packet arrivals

施工测量也以地面控制点为基础，根据图纸上的建筑物的设计 尺寸，计算出各部分的特征点与控制点之间的距离、角度（或方位 角）、高差等数据，将建筑物的特征点在实地标定出来，以便施工 ，这项工作又称“放样”