J.Ysanne's blog

引言 Internet-connected “things”: laptops, tablets, smartphones → game consoles, surveillance systems, watches, eye glasses, thermostats, cars… What you will learn ? —— a broad overview of computer networking and the Internet. Introducing some basic terminology and concepts. Examining the basic hardware and software components. The network’s edge(网络边缘): end systems(端系统) and network applications(网络应用). The core of a computer network(网络核心): links(链路) and switches(交换机) —— transport...

Review Questions What is the difference between a host and an end system? List several different types of end systems. Is a Web server an end system? There is no difference. Throughout this text, the words “host” and “end system” are used interchangeably. End systems include PCs, workstations, Web servers, mail servers, PDAs(Personal Digital Assistants), Internet-connected game consoles, etc. Yes. The word protocol is often used to describe diplomatic relations. How does Wikipedia...

现代优化算法是 20世纪 80年代初兴起的启发式算法，包括禁忌搜索（Tabu Search）、模拟退火（Simuated Annealing）、遗传算法（Cenetic Algorithnas）、人工神经网络（Neural Networks）。 它们主要用于解决那些传统优化方法（如梯度下降法、牛顿法、单纯形法等）难以处理或效率低下的复杂问题。这些问题通常具有高维度、非线性、非凸性、多峰性、不连续性、存在大量局部最优解，或者目标函数难以求导等特点。 12.1 模拟退火算法 模拟退火 (Simulated Annealing)。它来源于冶金学中对金属进行“退火”处理的过程。 加热 (High Temperature)：将金属加热到很高的温度，此时金属内部的粒子（原子）能量非常高，可以自由、无序地运动。 缓慢冷却 (Slow Cooling)：然后，非常缓慢地降低温度。在这个过程中，粒子能量逐渐降低，它们会自发地寻找能量最低、最稳定的位置，最终形成规整、坚固的晶体结构。 结果 (Low Energy...

1 在你的计算机上安装 GNU/Linux CS144 的作业需要 GNU/Linux 操作系统和一个支持 C++ 2023 标准的最新 C++ 编译器。请选择以下三个选项之一： 推荐：安装 CS144 VirtualBox 虚拟机镜像（说明在 https://stanford.edu/class/cs144/vm_howto/vm-howto-image.html）。 使用我们课程的优惠券代码，使用 Google Cloud 虚拟机（说明在 https://stanford.edu/class/cs144/vm_howto）。 运行 Ubuntu 24.04 版本，然后安装所需的软件包：12sudo apt update && sudo apt install git cmake gdb build-essential clang \clang-tidy clang-format gcc-doc pkg-config glibc-doc tcpdump tshark “风险自负”地使用其他 GNU/Linux...

In this chapter, we study the conceptual and implementation aspects of network applications. We begin by defining key application-layer concepts, including network services required by applications, clients and servers, processes, and transport-layer interfaces. We examine several network applications in detail, including the Web, e-mail, DNS, peer-to-peer (P2P) file distribution, and video streaming. We then cover network application development, over both TCP and UDP. In particular, we...

Transport layer provides communication services directly to the application processes running on different hosts. 3.1 Introduction and Transport-Layer Services logical communication A transport-layer protocol provides for logical communication between application processes running on different hosts. Application processes use the logical communication provided by the transport layer to send messages to each other, free from the worry of the details of the physical infrastructure used to...

The network layer can be decomposed into two interacting parts: the data plane The data plane functions of the network layer—the per-router functions in the network layer that determine how a datagram (that is, a network-layer packet) arriving on one of a router’s input links is forwarded to one of that router’s output links. the control plane The control plane functions of the network layer—the network-wide logic that controls how a datagram is routed among routers along an end-to-end path...

Two fundamentally different types of link-layer channels: broadcast channel It connect multiple hosts in wireless LANs, in satellite networks, and in hybrid fiber-coaxial cable (HFC) access networks. It needs medium access protocol to coordinate frame transmission. point-to-point communication link Coordinating access to a point-to-point link is simpler. It is used in settings ranging from dial-up service over a telephone line to high-speed point-to-point frame transport over fiber-optic...

配图分类： 数据图 体现模型的过程数据或结果数据，重点在于“展现模型效果” 根据图形分类：线图、饼图、柱状图、雷达图、地图、三维图、热⼒图等等 根据数据分类：⽐较类、分布类、流程类、地图类、趋势类、占⽐类 框架图 描述模型的流程结构或系统组成，重点在于“解释模型本身” ⼀般分类：思维导图、模型架构图、模型⽰意图、模型流程图等等