Common accessibility features

Although some accessibility features require special software downloads, many are built into the operating system of your computer or mobile device. Here are just a few types of accessibility features you may already have on your device.

• Features for blind or low-vision computer users: Features such as text-to-speech allow users to hear what's on the screen instead of reading it. Other features, like high-contrast themes and enlarged cursors, make it easier for users with limited vision to see the screen.

• Features for deaf or low-hearing computer users: Closed-captioning helps toconvey audio information to deaf users in visual form. Mono audio systems transmit right and left audio signals through both earbuds and headphones so users with limited hearing in one ear will not miss part of what they are listening to.

• Features for limited-mobility computer users: Keyboard shortcuts are convenient for many people, but they are especially helpful to those with difficulty physically manipulating a mouse. For users who have difficulty pressing several keys at once, sticky keys allows them to press keys one at a time to activate a shortcut.

Using accessibility features

Most computers and mobile devices come with built-in accessibility features, although they'll usually need to be turned on before you can use them. Let's take a look at how to locate these features for your device.

• In Windows, open the Settings app (or Control Panel in Windows 8 and earlier), then click Ease of Access.

• In OSX, open System Preferences, then click Accessibility (or Universal Access in older versions).

• On mobile devices that use Android or iOS, open the Settings app, then locate the Accessibility section. On iOS devices, you'll find it within theGeneral settings category.

Web accessibility

Most web browsers also offer their own built-in accessibility features. You'll usually find these options in your browser's settings.

Before you adjust these settings, you may want to try zooming instead. Zooming is an easy way to make web pages easier to read, and it works the same way in most browsers. If you're using a browser in Windows, you can zoom in or out by pressing Ctrl+ or Ctrl- (hold down the Ctrl key and press the + or - key). If you're using a Mac, you'll press Command+ or Command-.

To return to the default zoom level, press Ctrl+0 (hold down the Ctrl key and press thezero key). If you're using a Mac, press Command+0.

Accessibility features in specific software

There are many more accessibility features you can use, depending on the type of computer you have and the software you use. The resources below will direct you to accessibility features for some of the most commonly used applications.

• Microsoft Accessibility: Here, you'll find news on Microsoft's accessibility projects, as well as help pages on accessibility features in the Windows operating system and in the Microsoft Office suite.

• Apple Accessibility: This is Apple's overview site for accessibility features on Macs, iPods, iPhones, and iPads. From here, you can navigate to help documents for specific features.

• Google Accessibility: This is Google's help site for accessibility features on Android phones and tablets and in Chrome.

• Accessibility Features in Firefox: This is Mozilla's official help site for Firefox's accessibility features.

• AppleVis: This community-based website offers tips, tutorials, and product reviews for blind and low-vision users of Apple products.

Assistive technology devices

As you've already seen, software can do a lot to make computers more accessible for disabled users. However, some accessibility features require extra hardware, or assistive technology. Most assistive-technology devices are similar to keyboards and speakers—they are peripherals that can be plugged into the main computer. Here are some common types of assistive technology you may encounter.

• Screen magnifiers: Screen magnifiers can be placed over your computer's monitor to ensure the content on the screen always appears magnified. Today, most people use the magnifier or zoom features on their operating systems to view content, but external magnifiers are still available as well.

• Alternative keyboards: For people who have difficulty using standard keyboards, there are a range of alternative options. For example, users can purchase keyboards with larger keys that are easier to see or press. They can also buy keyboards with alternative key arrangements, including arrangements for people who can only type with one hand or with a limited number of fingers.

• Switch-adapted peripherals: Switch devices allow people with limited mobility to control technology with very small motions, such as a puff of breath or a head movement. Switch-adapted mice and keyboards make it possible for disabled users to interact with computers even if they are unable to operate peripherals with their hands.

Where to buy assistive technology devices

• Ablenet: Computer Access: Here, you can purchase a wide range of assistive-technology devices. You'll also find information on what types of devices are useful for specific disabilities.

• Compusult: Computer Access for Physical Disabilities: Compusult offers assistive and other types of technology to individuals and businesses. Italsoprovidestrainingcoursesonassistivetechnology.

• Inclusive Technology: Here, you'll find assistive-technology products, as well as educational software designed for K-12 students with disabilities.

More resources

• Alliance for Access to Computing Careers: This website offers information on accommodations and accessible design that can be useful for teachers and students in technology fields.

• My Web My Way: This site was created by the BBC. Here, you can find detailed guides on how to change a variety of settings to make your computer more accessible and easier to use.

• National Center for Learning Disabilities: Here, you'll find useful information on learning disabilities, assistive technology, and appropriate accommodations for work and school.

• Tech-Ease 4 All: This site has resources for teachers and parents who want to use technology and computers with disabled students.

Bringing your files with you

When you're working on a document or other computer file, you can always save it to your computer's hard drive. But sometimes you may want to bring your file with youand open it on a different computer. In this lesson, we'll talk about two ways to save your files so you can access them from almost anywhere.

• Flash drive: Flash drives are small removable hard drives that plug into theUSB ports on your computer. They are relatively inexpensive (usually less than $20) and can be purchased at any store with an electronics section.

• Cloud storage: Cloud storage means you save your files on servers on the Internet using an account with a cloud service. With cloud storage, you can access your files from any computer with Internet access without having to keep track of a physical device.

Flash drives and the cloud can also be used to back up your files. To learn more, check out our lesson on Backing Up Your Files.

Using a flash drive

Flash drives make it easy to carry your important files and documents with you in a portable form. You should always back up the files on your flash drive elsewhere, however, just in case it gets lost or breaks.

To connect a flash drive:

1. Insert the flash drive into a USB port on your computer. You should find a USB port on the front, back, or side of your computer (the location may vary depending on whether you have a desktop or laptop).

2. If you're using Windows, a dialog box may appear. If it does, select Open folder to view files. On a Mac, a flash drive icon will usually appear on the desktop.

3. If a dialog box does not appear, open Windows Explorer—or Finder if you're using a Mac—and select the flash drive on the left side of the window. Note that the name of the flash drive may vary.

To work with a flash drive:

Once you've connected a flash drive, you can work with it just like any other folder on your computer, including moving and deleting files.

1. If you want to copy a file from your computer to the flash drive, click and drag the file from your computer to this window.

2. The file will be duplicated, and this new version will be saved to the flash drive. The original version of the file will still be saved to your computer.

3. If you want to copy a file from your flash drive to your computer, click and drag the file from this window to your computer.

4. If you want to remove a file from your flash drive, click and drag the file to the Recycle Bin on a PC or the Trash can on a Mac. A dialog box may appear appear. If it does, click Yes to confirm that you want to permanently delete the file.

If a dialog box does not appear, you may need to empty the Trash can to permanently delete the file.

To safely remove a flash drive:

When you're done using a flash drive, don't remove it from the USB port just yet. You'll need to make sure to disconnect it properly to avoid damaging files on the drive.

1. Right-click the flash drive and select Disconnect (or Eject).

2. You can now safely remove the flash drive from the USB port.

If you're using a Mac, you can also click the Eject button next to the flash drive inFinder to eject it.

Saving files to the cloud

There are many services that allow you to create a free account and save documents, images, and other files to the cloud. Some of the most popular are Google Drive,OneDrive, and Dropbox. The free storage space that comes with these accounts (usually around 15GB) should be plenty if you're using your account for regular personal, work, or school purposes. If you own a business and want to keep all of your documents in the cloud, you may want to pay your cloud service for more storage.

Unlike physical media, the cloud can't break or get lost, so you don't necessarily need to back up the files you keep on it. Files in the cloud are also easier to share so you can collaborate with friends and coworkers. However, when you save something online, there's always a risk that unauthorized users will try to gain access to your personal information. To protect your files, create a strong password and pay attention to the privacy settings and policies of the cloud service you're using.

To learn more about services that allow you to store your files in the cloud, check out our tutorials on Google Drive and OneDrive and Office Online.

Free software

There are free programs available for almost any purpose you can imagine. If you're looking for free software for a specific task or want to find a free alternative to an expensive commercial program, it's probably somewhere on the Internet. Often, the most difficult part is finding the safest, most reliable free programs among the thousands of other free programs.

Usually, the best way to find free software for Windows is to do an Internet search. On Android and iOS devices, the best way to find free software is to search in the Play Store or App Store for apps that are listed as free. For Mac OS, both the App Store and Internet searches are effective methods for finding free software.

When there is no fee to use software, it is sometimes called software gratis or freeware.

Safely searching for free software

When searching for free software, distinguishing good software from bad or dangerous software is crucial. These steps will help you find a program that is safe, reliable, and performs the functions you need.

• Identify your needs and the tasks you are trying to accomplish. Do you need a simple tool or something very powerful? Are you trying to perform a specialized task, or are you looking for something generally useful? Areyoujustlookingtosavemoney?

• Search for information on a program before downloading it. Determine if the publisher is reliable and well-liked, and if the program is safe and stable and has the features you want.

• Read reviews on neutral third-party sites; a publisher may remove negative reviews from its own site.

• Don't click misleading advertisements designed to look like download links or error messages. Carefully examine download links before clicking, or installanadblocker.

• Avoid malware included in installers. If an installer has options for custom search bars or other programs that seem unrelated, tell it not to install these.

• Download directly from the developer's website rather than from a third-party site. Many—but not all—third-party file hosting sites include malware with their installers.

• Scan for viruses and malware immediately after installing a new program. It's better to avoid installing malware, but scans will probably catch anything you missed.

In the image above, the download button at the bottom-left is the real download link, while the other two are misleading ads.

Keep in mind that these safety tips are good practices whether you're downloading free software or paying for software. There's nothing stopping a distributor from bundling malware with a program and still charging you a fee for it, and plenty of commercial software is unstable or ineffective. Be aware at all times of common unscrupulous practices so you can avoid them and choose the best software for your needs.

Examples of free software

One of the biggest advantages of free software is determining your specific needs and searching for the program that's right for you, but sometimes it's helpful to see what software other people are using. Here's a list of some of our favorite free software for common tasks.

Securityandsystemoptimization

• CCleaner: Optimizationandstoragemanagement

• Avast!: Antivirussoftware

• Malwarebytes: Anti-malwaresoftware

Productivity

• LibreOffice: A full-featured office suite

• Thunderbird: Emailmanagementsoftware

• Keynote: Note-taking and organizational software

• Metapad: Anadvancedtexteditor

• FoxitReader: A PDF viewer

• CutePDF: A PDF writer that works like a virtual printer

Media

• Paint.NET: A simple image editor

• GIMP: A complex and powerful image editor

• VLC media player: A cross-platform multimedia player

• K-Lite Codec Pack Standard: A multimedia player package

• Dropbox: Cloud storage, file synchronization, and file hosting

Why is some software free?

There are many reasons a developer may not be charging a fee for its software. In most cases, developers are still earning money through other means. Here are some of the common ways free software still makes money.

• Donations: The software is free, but users can donate money to support the developer.

• Advertisements: The developer is paid by other companies to place advertisements in the software or on its website.

• Data mining: The software collects information about users and sells this to advertisers or marketing researchers. Thisisoftenusedincombinationwithadvertisements.

• Bundling other software: Other software distributors pay the developer to bundle other programs with its software. Thisoftenincludesmalware.

• In-app purchases: The base software is free, but users can pay fees to unlock additional features.

• Premium products or subscriptions: The software itself is free, but the developer sells more advanced versions of the program or other programs.

Not all free software developers earn money from software. They may have full-time jobs and make software in their free time as a hobby, they may be working under a license that prohibits earning profit from the software, or they might just enjoy participating in free software communities on the Internet.

Some software is freely available because the developers adhere to certain social and ethical guidelines. This software is sometimes called software libre, although it's also sometimes called free software, using the definition of free that means liberty, not free of charge. You can read more about this type of free software at the Mozilla Foundationor the Free Software Foundation.

Support free software developers

After using free software for a while, if you are happy with the programs consider supporting their developers. Visit their websites, and look for ways you can help. They may have links for you to donate money, contribute your talents to their projects, or promote their software on social media. But remember, your support is a choice, not an obligation. Free software communities thrive on individual choice and mutual assistance.

№5 LECTURE

• Database systems.

• Basics of database systems: concept, characteristic architecture.

• Data models.

• Normalization.

• Restricting data integrity.

• Query optimization and processing.

• Fundamentals SQL.

• The parallel data processing and recovery.

• Design and develop databases.

• ORM software technology.

• Distributed parallel and heterogeneous database.

Alternatively referred to as a databank or a datastore, and sometimes abbreviated as a DB, a database is a large quantity of indexed digital information. It can be searched, referenced, compared, changed or otherwise manipulated with optimal speed and minimal processing expense.

DBMS

Short for DataBase Management System, DBMS is a software program that allows the user to create, manipulate, retrieve and store information in a database. They come in many forms, ranging from hotel reservation systems to automated teller machines.

DATABASE SYSTEMS

1. Data vs. Information

2. Basics of database systems: concept, characteristic architecture.

3. Data models.

4. Types of databases

In general, data is any set of characters that has been gathered and translated for some purpose, usually analysis. It can be any character, including text and numbers, pictures, sound, or video. If data is not put into context, it doesn't do anything to a human or computer.

Data vs. Information

• Data:

  • Raw facts; building blocks of information

  • Unprocessed information

Information:

• Data processed to reveal meaning

• Accurate, relevant, and timely information is key to good decision making

• Good decision making is the key to survival in a global environment

• Database—shared, integrated computer structure that stores:

  • End user data (raw facts)

  • Metadata (data about data)

What is a Database?

• “A set of information held in a computer”

Oxford English Dictionary

• “One or more large structured sets of persistent data, usually associated with software to update and query the data”

Free On-Line Dictionary of Computing

• “A collection of data arranged for ease and speed of search and retrieval”

Dictionary.com

Introducing the Database and the DBMS (continued)

• DBMS (database management system):

  • Collection of programs that manages database structure and controls access to data

  • Possible to share data among multiple applications or users

  • Makes data management more efficient and effective

Role and Advantages of the DBMS (continued)

• End users have better access to more and better-managed data

  • Promotes integrated view of organization’s operations

  • Probability of data inconsistency is greatly reduced

  • Possible to produce quick answers to ad hoc queries

What is a database ?

• A collection of files storing related data

Give examples of databases

• Accounts database; payroll database; UW’s students database; Amazon’s products database; airline reservation database

What the Database Systems Does

1. Create/store large datasets

2. Search/query/update

3. Change the structure

4. Concurrent access to many user

5. Recover from crashes

6. Security

• Database Management Systems

• A database is a collection of information

• A database management system (DBMS) is the software than controls that information

• Examples:

  • Oracle

  • DB2 (IBM)

  • MS SQL Server

  • MS Access

  • Ingres

  • PostgreSQL

  • MySQL

Files and Databases

• File: A collection of records or documents dealing with one organization, person, area or subject. (Rowley)

  • Manual (paper) files

  • Computer files

• Database: A collection of similar records with relationships between the records. (Rowley)

  • bibliographic, statistical, business data, images, etc.

• Database Management System -- DBMS

  • Software system used to define, create, maintain and provide controlled access to the database and repository

Terms and Concepts

• Database Management System -- DBMS

  • Software system used to define, create, maintain and provide controlled access to the database and repository

Why DBMS?

• History

  • 50’s and 60’s all applications were custom built for particular needs

  • File based

  • Many similar/duplicative applications dealing with collections of business data

  • Early DBMS were extensions of programming languages

  • 1970 - E.F. Codd and the Relational Model

  • 1979 - Ashton-Tate & first Microcomputer DBMS

Role and Advantages of the DBMS (continued)

Terms and Concepts

• Database activities:

- Create

• Add new data to the database

- Read

• Read current data from the database

- Update

• Update or modify current database data

-Delete

• Remove current data from the database

• Enterprise

  • Organization

• Entity

  • Person, Place, Thing, Event, Concept...

• Attributes

  • Data elements (facts) about some entity

  • Also sometimes called fields or items or domains

• Data values

  • instances of a particular attribute for a particular entity

• Records

  • The set of values for all attributes of a particular entity

  • AKA “tuples” or “rows” in relational DBMS

• File

  • Collection of records

  • AKA “Relation” or “Table” in relational DBMS

• Key

  • an attribute or set of attributes used to identify or locate records in a file

• Primary Key

  • an attribute or set of attributes that uniquely identifies each record in a file

• DA

  • Data adminstrator - person responsible for the Data Administration function in an organization

  • Sometimes may be the CIO -- Chief Information Officer

• DBA

  • Database Administrator - person responsible for the Database Administration Function

• Data Administration

  • Responsibility for the overall management of data resources within an organization

• Database Administration

  • Responsibility for physical database design and technical issues in database management

• Data Steward

  • Responsibility for some subset of the organization’s data, and all of the interactions (applications, user access, etc.) for that data

• Models

  • (1) Levels or views of the Database

    • Conceptual, logical, physical

  • (2) DBMS types

    • Relational, Hierarchic, Network, Object-Oriented, Object-Relational

Types of databases

1. A document-oriented database is a computer program designed for storing, retrieving, and managing document-oriented, or semi structured data, information

2. Embedded database. These databases consist of data developed by individual end-users. Examples of these are collections of documents, spreadsheets, presentations, multimedia and other files.

1. Graph database is a kind of No SQL database that uses graph structures with nodes, edges, and properties to represent and store information

2. 

4. Hypertext databases are particularly useful for organizing large amounts of disparate information. For example they are useful for maintaining online encyclopedias.

3. A distributed database is a database in which storage devices are not all attached to a common processing unit such as the CPU. It may be stored in multiple computers located in the same physical location, or may be dispersed over a network of interconnected computers.

A database management system (DBMS) is system software for creating and managing databases. The DBMS provides users and programmers with a systematic way to create, retrieve, update and manage data.

DBMS makes it possible for end users to create, read, update and delete data in a database. The DBMS essentially serves as an interface between the database and end users or application programs, ensuring that data is consistently organized and remains easily accessible.

The DBMS manages three important things: the data, the database engine that allows data to be accessed, locked and modified -- and the database schema, which defines the database’s logical structure. These three foundational elements help provideconcurrency, security, data integrity and uniform administration procedures. Typical database administration tasks supported by the DBMS include change management, performance monitoring/tuning and backup and recovery. Many database management systems are also responsible for automated rollbacks, restarts and recovery as well as the logging and auditing of activity.

The DBMS is perhaps most useful for providing a centralized view of data that can be accessed by multiple users, from multiple locations, in a controlled manner. A DBMS can limit what data the end user sees, as well as how that end user can view the data, providing many views of a single database schema. End users and software programs are free from having to understand where the data is physically located or on what type of storage media it resides because the DBMS handles all requests.

The DBMS can offer both logical and physical data independence. That means it can protect users and applications from needing to know where data is stored or having to be concerned about changes to the physical structure of data (storage and hardware). As long as programs use the application programming interface (API) for the database that is provided by the DBMS, developers won't have to modify programs just because changes have been made to the database.

With relational DBMSs (RDBMSs), this API is SQL, a standard programming language for defining, protecting and accessing data in a RDBMS.

Popular types of DBMSes

Popular database models and their management systems include:

Relational database management system (RDMS)  - adaptable to most use cases, but RDBMS Tier-1 products can be quite expensive.

NoSQL DBMS - well-suited for loosely defined data structures that may evolve over time. 

In-memory database management system (IMDBMS) - provides faster response times and better performance.

Columnar database management system (CDBMS) - well-suited for data warehousesthat have a large number of similar data items.

Cloud-based data management system - the cloud service provider is responsible for providing and maintaining the DBMS.