Database needs to be designed, and database design is reflected in two aspects:Database logic design: Design the logical structure of the database, which has nothing to do with the specific DBMS, and...

Brief introduction There are many ways to outline design. In the early days, there were modular methods and functional decomposition methods; in the late 1960s, data flow-oriented and data structure-...

Editor's recommendation Examples Several simple examples that help make the concept clear and easy to understand are closely run through each chapter. The Karnaugh map can be used flexibly to help st...

About the author Randy H.Kata, Professor of Electrical Engineering and Computer Science at the University of California, Berkeley, and Dean of the Department of Electrical Engineering and Computer Sc...

Overview of Local Area Network (LAN) Definition of Local Area NetworkThe definition and characteristics of LAN: small coverage area; low cost; high transmission rate; low bit error rate, reliable H...

Introduction The local area network is naturally a regional network formed in a local area. It is characterized by a limited distribution area, which can be large or small, as large as between a bui...

Introduction In 1999, IEEE promulgated the 802.1Q protocol standard draft for standardized VLAN implementation. The emergence of VLAN technology allows administrators to logically divide different u...

Basic Concepts All sites in a switched LAN are connected to a switching hub or LAN switch. Switching hubs or LAN switches have switching functions. Their characteristics are: all ports are not connec...

Introduction In the telecommunications industry, a Network-to-Network Interface (Network-to-Network Interface, referred to as: NNI) is a specific designation of two networks The interface between si...

Application introduction Publishing on QQ space is actually expressing your mood at that time. What is your mood? It is also a good way to communicate with others by talking. The QQ space I collected...

Yellow Diamond Permission Yellow Diamond Classification and Function Comparison Table Level System In 2007, Qzone launched a new yellow diamond noble Hierarchy system. According to the record of cont...

How to authenticate Authentication conditions1: Qzone users (if not users of Qzone, please register and activate Qzone first) 2: Original users, the space has published at least 20 logs, and can kee...

Reasons for failure Driver problemsThis is also an important cause of screen glitches. It usually occurs after changing the graphics card driver version, or it may be caused by damaged driver files...

Introduction The QQ space code is used to decorate the QQ space. Some people’s spaces are very beautiful because they decorate them with codes. QQ space is decorated with navigation, opening animatio...

Concept Scientific notation is a method of counting numbers. Express a number in the form of multiplying a and 10 to the nth power (1≤|a|<10, a is not a fraction, n is an integer), this...