MIT OCW DATA COMMUNICATION CONTENTS Lectures 2 The Data Link Layer: Framing and Error Detection Lectures 3 4 The Data link layer: arQ Protocols Lectures 5 6 Introduction to Queueing Theory Lectures 8&9 M/G/I Queues

CHAPTER 3Lists S1 Abstract Data Type (ADT) Definition Data Type Objects Operations Example】int={0,±1,±2,…,IT_MAX,IT_MIN} +,-,×,÷,%,…} 【 Definition】 An Abstract Data Type(adt) is data type that is organized in such a way that the specification on the objects and specification of the

1 Risks of data loss and corruption 2 Data consistency Checksums Block checksums 3 Data safety Redundancy Parity Erasure coding 4 Conclusion

1 Data format Row vs Column 2 Compressing data Compression algorithms Efficiency and use cases 3 Data addressing Hierarchical namespaces Limitations Flat namespaces 4 Stateful interfaces POSIX Limitations Stateless interfaces 5 Conclusion

3.1 Definition of data structure 3.2 Stacks 3.3 Queues 3.4 Linked lists 3.5 Trees 3.6 Postfix expression 3.7 Infix to postfix conversion

Sorting: There is a series of data in random order, we sort them depending a certain key word Datalist: an finity set of data waiting to be sorted Key: data object has many attribute areas, namely there are many data element, one of all these elements can be used to distinguish object, we use it as sorting key. we also call it sorting code

• Analysis of Algorithms – worst case time and space complexity • Data Structures – stack, queue, linked list, tree, priority queue, heap, hash, and graph, • Searching algorithms – binary and AVL search trees; • Sorting algorithms – merge sort, quick sort, bucket sort and radix sort; (Reduce some contents) • Graph – data structure, depth first search and breadth first search. (add some interesting contents). • shortest path

l Chapter 2-Learning objectives Convert raw data into a data array Construct a frequency distribution a relative frequency distribution a cumulative relative frequency distribution Construct a stem-and-leaf diagram Visually represent data by using graphs and charts

A True panel vs a Pooled cross section Often loosely use the term panel data to refer to any data set that has both a cross sectional dimension and a time-series dimension More precisely it's only data following the same cross-section units over time Otherwise it's a pooled cross-section Economics 20- Prof anderson

2.1 Understand the nature of data as it relates to business intelligence (BI) and analytics 2.2 Learn the methods used to make real-world data analytics ready 2.3 Describe statistical modeling and its relationship to business analytics 2.4 Learn about descriptive and inferential statistics 2.5 Define business reporting, and understand its historical evolution