chapter 3  querying entity data models

... recursion Programming Higher−order programming Control abstractions Abstract data types Secure abstract data types Procedural Data The real world A bstraction Figure 3.2: Structure of the chapter If ... space efficiency Nondeclarative needs Limitations and extensions Relation to other declarative models What is declarativeness? Iterative and recursive computation Programming with lists and trees ... written in the declarative model are easier to reason about than programs written in more expressive models. Since declarative programs compute only values, simple algebraic and logical reasoning techniques

Ngày tải lên: 14/08/2014, 10:22

... Data Structure and Algorithms [CO2003] Chapter - Recursion Lecturer: Duc Dung Nguyen, PhD Contact: ... actorial(n − 1) if n = if n > base case general case Recursion Figure Factorial (3) Recursively (source: Data Structure - A pseudocode Approach with C++) Recursion Factorial: Iterative Solution Algorithm

Ngày tải lên: 29/03/2017, 18:21

... Superclasses  In many cases an entity type has numerous subgroupings of its entities that are meaningful and need to be represented explicitly because of their significance to the database application ... Subclasses, Superclasses  We call each of these subgroupings a subclass of the EMPLOYEE entity type, and the EMPLOYEE entity type is called the superclass for each of these subclasses  These are called ... SECRETARY IS-A EMPLOYEE, TECHNICIAN IS-A EMPLOYEE, … Subclasses, Superclasses  An Entity CANNOT exist in the database merely by being a member of a subclass; it must also be a member of the superclass

Ngày tải lên: 15/05/2017, 10:33

... reserved 3.1 Data Categorization 3- • Two broad categories of data are numeric and string – Numeric data must contain only numbers – String data can contain any symbol – Numeric data is used ... and string data • Determine whether a data item should be a constant or variable • Code constants and variables in event procedures • Describe the characteristics and uses of standard data types ... CHAPTER THREE Representing Data: Constants and Variables Chapter Introduction 3- • Compose event procedures that perform more sophisticated tasks • Focus specifically on data items • Continue work

Ngày tải lên: 16/05/2017, 14:40

... analysis Distributed data ✘ Centralized database ✘ Pro: No duplication of data ✘ Con: Contention for access ✘ Replicated database ✘ Pro: No contention ✘ Con: High storage and data reorg/update costs ... Chapter : Distributed Data Processing Business Data Communications, 4e Centralized Data Processing ✘ Centralized computers, processing, data, control, support ✘ What are the advantages? ... Dramatically reduced workstation costs ✘ Improved user interfaces and desktop power ✘ Ability to share data across multiple servers DDP Pros & Cons ✘ There are no “one-size-fits-all” solutions ✘ Key

Ngày tải lên: 12/12/2017, 08:17

... Nature of Secondary Data To understand how firms create an internal database Creating An Internal Database An Internal Database is a collection of related information developed from data already within ... management systems The Nature of Secondary Data Learning Objectives To understand the advantages and disadvantages of secondary data Secondary Data: Data that have previously been gathered and ... Secondary Data & Databases Copyright © 2004 John Wiley & Sons, Inc Learning Objectives Learning Objectives To understand how firms create an internal database To learn about building a database

Ngày tải lên: 18/01/2020, 20:43

...                             of  of                               Grouped Data Grouped Data The mean of a sample of data organized  The mean of a sample of data organized  in a frequency distribution is  in a frequency distribution is  ... Finding the Median of  Grouped Data Grouped Data 3 ­ 49 To determine the median class for Grouped Data: 1.  Construct a cumulative frequency distribution 2.   Divide the total number of data values by 2 3.   Determine which class will contain this value ... …Every set of interval­level and ratio­ level data has a mean … All the values are included in  computing the mean …A set of data has a unique mean …The mean is affected by unusually  large or small data values …The arithmetic mean is the                                   

Ngày tải lên: 03/02/2020, 17:43

... Data Security and Encryption (CSE348) Lecture # 3 Review • Security concepts: – confidentiality, integrity, availability • • • • Security attacks, services, mechanisms Models for network ... time is required to conduct a bruteforce attack, for various common key sizes Brute Force Search • Data Encryption Standard(DES) is 56 • Advanced Encryption Standard (AES) is 128 • Triple-DES is ... English or whatever) • Usually easy for humans, hard for computers • Though if using say compressed data could be much harder 30 Cryptanalysis of Caesar Cipher • Example "GCUA VQ DTGCM" when broken

Ngày tải lên: 20/09/2020, 13:57

... DIGITAL Data can be  analog  or  digital. The term  analog data  refers  to  information  that  is  continuous;  digital  data  refers  to  information  that  has  discrete  states.  Analog  data  ... continuous values. Digital data take on discrete values Topics discussed in this section: Analog and Digital Data Analog and Digital Signals Periodic and Nonperiodic Signals 3.3 Note Data can be analog ... Chapter Data and Signals 3.1 Copyright © The McGraw­Hill Companies, Inc. Permission required for reproduction or display Note To be transmitted, data must be transformed to

Ngày tải lên: 23/09/2020, 13:32

... memory” of an object e Each field has a data type (int, double, String, Color, Location, etc.) Trang 20 You name it! Fields (cont'd) \ private [static] [final] datatype name; Usually - private ... how to call their methods Learn a little about inheritance in OOP Trang 3 OOP e An OO program models the application as a world of interacting objects e An object can create other objects e ... object can call another object’s (and Its own) methods (that Is, “send messages’) e An object has data fields, which hold values that can change while the program Is running Trang 4 Objects

Ngày tải lên: 04/11/2020, 23:13

... different concepts Keywords: big data, big educational data, analytics, health education, quality improvement 1 Introduction (2)2 Big data and education 2.1 BIG DATA Big data is extensively used as ... make sense of the data by processing them in a high analytical level to enable data-driven improvement of processes and procedures [3] Big data and analytics have added value to data possessed in ... data-driven activities concerning quality improvement in education 2.2 BIG EDUCATIONAL DATA (3)data [6] Such techniques can be derived and adapted from other domains characterized by big data

Ngày tải lên: 08/02/2021, 07:45

... Theory, Concepts and Models Bob McKercher and Bruce Prideaux Tourism Theories, Concepts and Models by McKercher and Chapter 3: The Structure of Tourism Tourism Concepts, Theories and Models © Bob McKercher ... Learning Objectives • • • • • Describe the key elements of systems models Compare and contrast different open and closed ended models of tourism Demonstrate how each of us operates within our own ... Discuss how space change can lead to adverse impacts of tourism Tourism Theories, Concepts and Models by McKercher and Tourism as a system • • • A system is defined as a set of elements standing

Ngày tải lên: 21/10/2022, 18:41

... False] } # Create DataFrame dataframe = pd.DataFrame(dictionary) # Show DataFrame dataframe Name Ag Driv e er Jacky Jackson 38 True Steven 25 False Stevenson Chúng ta dễ dàng thêm cột Dataframe: # ... có trùng số index number Tạo Dataframe Tạo Dataframe từ Python dictionary pandas có nhiều phương thức để tạo đối tượng DataFrame Một phương pháp dễ dàng khởi tạo DataFrame dictionary Python Trong ... color dataframe["Eyes"] = ["Brown", "Blue"] # Show DataFrame dataframe Name Jacky Jackson Ag Driv e er 38 True Eyes Brow n Steven 25 False Blue Stevenson pandas cung cấp vô số cách để tạo DataFrame

Ngày tải lên: 18/10/2023, 20:54

... and display of data. The view is a flexible feature of the tree that can handle everything from simple data in a content view to more dynamic data from a custom view or an RDF datasource (builder ... data is expected to be high. The tree widget has a simpler, more lightweight layout, but it is more difficult to use, requiring the addition of special "views" in order to display data. ... categories of datasource, speed, and type of usage. Table 3-2. Tree views Content view Builder view Custom view Rows are built from a content model. Rows are built from an RDF datasource. Consumer

Ngày tải lên: 17/10/2013, 19:15

... special information about the requested URL  Entity headers describe the document format of the data being sent between client and server Although Entity headers are most commonly used by the ... the entity Content-Language Content-Length Content-Location Content-MD5 Specifies the language used in the document being returned Specifies the length of the entity Contains the URL for the entity, ... media type of the entity Etag Gives an entity tag for the document Expires Gives a date and time that the contents may change Last-Modified Gives the date and time that the entity last changed

Ngày tải lên: 17/10/2013, 19:15

... Kumar Introduction to Data Mining 35 OLAP Operations: Data Cube The key operation of a OLAP is the formation of a data cube A data cube is a multidimensional representation of data, together with ... Introduction to Data Mining Visualization Visualization is the conversion of data into a visual or tabular format so that the characteristics of the data and the relationships among data items or ... Introduction to Data Mining separate face becomes a Star Plots for Iris Data Setosa Versicolour Virginica © Tan,Steinbach, Kumar Introduction to Data Mining 29 Chernoff Faces for Iris Data Setosa...

Ngày tải lên: 15/03/2014, 09:20

... components Data and Signals Usually use digital signals for digital data and analog signals for analog data Can use analog signal to carry digital data Modem Can use digital signal to carry analog data ... DC Component Data Rate and Bandwidth Any transmission system has a limited band of frequencies This limits the data rate that can be carried Analog and Digital Data Transmission Data Entities ... Signals Electric or electromagnetic representations of data Transmission Communication of data by propagation and processing of signals Data Analog Continuous values within some interval e.g...

Ngày tải lên: 16/02/2014, 08:20

... Algorithm (cont.) Push (val DataIn ) Pushes new data into the stack Pre DataIn contains data to be pushed Post If stack is not full, DataIn has been pushed in; otherwise, ... (cont.) Top (ref DataOut ) Retrieves data on the top of the stack without changing the stack Pre none Post if the stack is not empty, DataOut receives data on its top The stack ... Specifications for Stack ADT Create() Push (val DataIn ) Pop () Top (ref DataOut ) isEmpty () isFull () ...

Ngày tải lên: 06/03/2014, 17:20

... Input is one start cell Ouput is any solution or all solutions if exists • What kind of data, and which data need to be push into the stack? 30 Knight’s tour Problem The knight is placed on the ... size of chess board) Ouput may be any solution or all solutions, if exists 8 What kind of data, and which data need to be push into the stack? 32 Queens problem Determine how to place the Queens ... solution or all solutions, if exists Two of 92 solutions of Eight Queens Problem What kind of data, and which data need to be push into the stack? 36 We will see a lot of interesting problems involved...

Ngày tải lên: 06/03/2014, 17:20