Mouse

Mouse (computing)

In computing, a mouse is a pointing device that detects two-dimensional motion relative to a surface. This motion is typically translated into the motion of a pointer on a display, which allows for fine control of a graphical user interface.

Physically, a mouse consists of an object held in one's hand, with one or more buttons. Mice often also feature other elements, such as touch surfaces and "wheels", which enable additional control and dimensional input.

The device was patented in 1947, but only a prototype using a metal ball rolling on two rubber-coated wheels was ever built and the device was kept as a military secret.

Another early trackball was built by British electrical engineer Kenyon Taylor in collaboration with Tom Cranston and Fred Longstaff. Taylor was part of the original Ferranti Canada, working on the Royal Canadian Navy's DATAR (Digital Automated Tracking and Resolving) system in 1952.

DATAR was similar in concept to Benjamin's display. The trackball used four disks to pick up motion, two each for the X and Y directions. Several rollers provided mechanical support. When the ball was rolled, the pickup discs spun and contacts on their outer rim made periodic contact with wires, producing pulses of output with each movement of the ball. By counting the pulses, the physical movement of the ball could be determined. A digital computer calculated the tracks, and sent the resulting data to other ships in a task force using pulse-code modulation radio signals. This trackball used a standard Canadian five-pin bowling ball. It was not patented, as it was a secret military project as well.

Early mouse patents. From left to right: Opposing track wheels by Engelbart, Nov. 1970, U.S. Patent 3,541,541. Ball and wheel by Rider, Sept. 1974, U.S. Patent 3,835,464. Ball and two rollers with spring by Opocensky, Oct. 1976, U.S. Patent 3,987,685

Independently, Douglas Engelbart at the Stanford Research Institute (now SRI International) invented his first mouse prototype in the 1960s with the assistance of his lead engineer Bill English. They christened the device the mouse as early models had a cord attached to the rear part of the device looking like a tail and generally resembling the common mouse. Engelbart never received any royalties for it, as his employer SRI held the patent, which ran out before it became widely used in personal computers. The invention of the mouse was just a small part of Engelbart's much larger project, aimed at augmenting human intellect via the Augmentation Research Center.

Inventor Douglas Engelbart's computer mouse, showing the wheels that make contact with the working surface.

Several other experimental pointing-devices developed for Engelbart's oN-Line System (NLS) exploited different body movements – for example, head-mounted devices attached to the chin or nose – but ultimately the mouse won out because of its speed and convenience. The first mouse, a bulky device (pictured) used two wheels perpendicular to each other: the rotation of each wheel translated into motion along one axis. At the time of the "Mother of All Demos", Englebart's group had been using their second generation, 3-button mouse for about a year. See the image of that mouse at Picture showing 2nd G mouse (A public domain version of this image would be nice.)

Camera

Camera

A camera is an optical instrument for recording images, which may be stored locally, transmitted to another location, or both. The images may be individual still photographs or sequences of images constituting videos or movies. The word camera comes from camera obscura, which means "dark chamber" and is the Latin name of the original device for projecting an image of external reality onto a flat surface. The modern photographic camera evolved from the camera obscura. The functioning of the camera is very similar to the functioning of the human eye.

Functional description

Basic elements of a modern still camera

A camera may work with the light of the visible spectrum or with other portions of the electromagnetic spectrum. A still camera is an optical device which creates a single image of an object or scene, and records it on an electronic sensor or photographic film. All cameras use the same basic design: light enters an enclosed box through a converging lens and an image is recorded on a light-sensitive medium. A shutter mechanism controls the length of time that light can enter the camera. Most photographic cameras have functions that allow a person to view the scene to be recorded, allow for a desired part of the scene to be in focus, and to control the exposure so that it is not too bright or too dim. A display, often a liquid crystal display (LCD), permits the user to view scene to be recorded and settings such as ISO speed, exposure, and shutter speed.

A movie camera or a video camera operates similarly to a still camera, except it records a series of static images in rapid succession, commonly at a rate of 24 frames per second. When the images are combined and displayed in order, the illusion of motion is achieved.

Laptop or Notebook

Laptop or Notebook

A laptop or a notebook is a portable personal computer with a clamshell form factor, suitable for mobile use. There was a difference between laptops and notebooks in the past, but nowadays it has gradually died away. Laptops are commonly used in a variety of settings, including at work, in education, and for personal multimedia.

A laptop combines the components and inputs of a desktop computer, including display, speakers, keyboard and pointing device (such as a touchpad or a trackpad) into a single device. Most modern-day laptops also have an integrated webcam and a microphone. A laptop can be powered either from a rechargeable battery, or by mains electricity via an AC adapter. Laptop is a diverse category of devices and other more specific terms, such as rugged notebook or convertible, refer to specialist types of laptops, which have been optimized for specific uses. Hardware specifications change significantly between different types, makes and models of laptops.

Portable computers, which later developed into modern laptops, were originally considered to be a small niche market, mostly for specialized field applications, such as the military, accountancy, for sales representatives etc. As portable computers developed and became more like modern laptops, becoming smaller, lighter, cheaper, and more powerful, they became very widely used for a variety of purposes.

Harddisk Drive

A hard disk drive (HDD), hard disk, hard drive or fixed disk is a data storage device used for storing and retrieving digital information using one or more rigid ("hard") rapidly rotating disks (platters) coated with magnetic material. The platters are paired with magnetic heads arranged on a moving actuator arm, which read and write data to the platter surfaces. Data is accessed in a random-access manner, meaning that individual blocks of data can be stored or retrieved in any order rather than sequentially. An HDD retains its data even when powered off.

Introduced by IBM in 1956, HDDs became the dominant secondary storage device for general-purpose computers by the early 1960s. Continuously improved, HDDs have maintained this position into the modern era of servers and personal computers. More than 200 companies have produced HDD units, though most current units are manufactured by Seagate, Toshiba and Western Digital. Worldwide disk storage revenues were US $32 billion in 2013, down 3% from 2012.

The primary characteristics of an HDD are its capacity and performance. Capacity is specified in unit prefixes corresponding to powers of 1000: a 1-terabyte (TB) drive has a capacity of 1,000 gigabytes (GB; where 1 gigabyte = 1 billion bytes). Typically, some of an HDD's capacity is unavailable to the user because it is used by the file system and the computer operating system, and possibly inbuilt redundancy for error correction and recovery. Performance is specified by the time required to move the heads to a track or cylinder (average access time) plus the time it takes for the desired sector to move under the head (average latency, which is a function of the physical rotational speed in revolutions per minute), and finally the speed at which the data is transmitted (data rate).

The two most common form factors for modern HDDs are 3.5-inch, for desktop computers, and 2.5-inch, primarily for laptops. HDDs are connected to systems by standard interface cables such as SATA (Serial ATA), USB or SAS (Serial attached SCSI) cables.

As of 2015, the primary competing technology for secondary storage is flash memory in the form of solid-state drives (SSDs), but HDDs remain the dominant medium for secondary storage due to advantages in price per unit of storage and recording capacity. However, SSDs are replacing HDDs where speed, power consumption and durability are more important considerations.

What is Android?

What is Android?

Android is a mobile operating system (OS) based on the Linux kernel and currently developed by Google. With a user interface based on direct manipulation, Android is designed primarily for touchscreen mobile devices such as smartphones and tablet computers, with specialized user interfaces for televisions (Android TV), cars (Android Auto), and wrist watches (Android Wear). The OS uses touch inputs that loosely correspond to real-world actions, like swiping, tapping, pinching, and reverse pinching to manipulate on-screen objects, and a virtual keyboard. Despite being primarily designed for touchscreen input, it also has been used in game consoles, digital cameras, regular PCs (e.g. the HP Slate 21) and other electronics.

As of July 2013 the Google Play store has had over one million Android applications ("apps") published, and over 50 billion applications downloaded. A developer survey conducted in April–May 2013 found that 71% of mobile developers develop for Android. At Google I/O 2014, the company revealed that there were over one billion active monthly Android users, up from 538 million in June 2013. As of 2015, Android has the largest installed base of all general-purpose operating systems.

Android's source code is released by Google under open source licenses, although most Android devices ultimately ship with a combination of open source and proprietary software, including proprietary software developed and licensed by Google. Initially developed by Android, Inc., which Google backed financially and later bought in 2005, Android was unveiled in 2007 along with the founding of the Open Handset Alliance—​a consortium of hardware, software, and telecommunication companies devoted to advancing open standards for mobile devices.

Android is popular with technology companies which require a ready-made, low-cost and customizable operating system for high-tech devices. Android's open nature has encouraged a large community of developers and enthusiasts to use the open-source code as a foundation for community-driven projects, which add new features for advanced users or bring Android to devices which were officially released running other operating systems. The operating system's success has made it a target for patent litigation as part of the so-called "smartphone wars" between technology companies.

What is Smartphone?

A smartphone (or smart phone) is a mobile phone with an advanced operating system.Smartphones typically include the features of a phone with those of other popular mobile devices, such as personal digital assistant, media player and GPS navigation unit. Most have a touchscreen interface and can run third-party apps, and are camera phones. Later smartphones add broadband internet web browsing, Wi-Fi, motion sensors and mobile payment mechanisms.

In February 2014, 93% of mobile developers were targeting smartphones first for app development.In 2014, sales of smartphones worldwide topped 1.2 billion, which is up 28% from 2013.

Early years

The first caller identification receiver

Devices that combined telephony and computing were first conceptualized by Theodore G. Paraskevakos in 1971 and patented in 1974, and were offered for sale beginning in 1993. He was the first to introduce the concepts of intelligence, data processing and visual display screens into telephones which gave rise to the "smartphone." In 1971, Paraskevakos, working with Boeing in Huntsville, Alabama, demonstrated a transmitter and receiver that provided additional ways to communicate with remote equipment, however it did not yet have general purpose PDA applications in a wireless device typical of smartphones. They were installed at Peoples' Telephone Company in Leesburg, Alabama and were demonstrated to several telephone companies. The original and historic working models are still in the possession of Paraskevakos.

Forerunners

IBM Simon and charging base (1993))

The first mobile phone to incorporate PDA features was an IBM prototype developed in 1992 and demonstrated that year at the COMDEX computer industry trade show. A refined version of the product was marketed to consumers in 1994 by BellSouth under the name Simon Personal Communicator. The Simon was the first cellular device that can be properly referred to as a "smartphone", although it wasn't called a smartphone in 1994. In addition to its ability to make and receive cellular phone calls, Simon was also able to send and receive faxes and e-mails and included several other apps like address book, calendar, appointment scheduler, calculator, world time clock, and note pad through its touch screen display. Simon is the first smartphone to be incorporated with the features of a PDA

The term "smart phone" appeared in print in 1995, for describing AT&T's "PhoneWriter(TM) Communicator" as a "smart phone".

iPhone & Android

In 2007, Apple Inc. introduced the iPhone, one of the first mobile phones to use a multi-touch interface. The iPhone was notable for its use of a large touchscreen for direct finger input as its main means of interaction, instead of a stylus, keyboard, or keypad typical for smartphones at the time. 2008 saw the release of the first phone to use Android called the HTC Dream (also known as the T-Mobile G1).Android is an open-source platform founded by Andy Rubin and now owned by Google.Although Android's adoption was relatively slow at first, it started to gain widespread popularity in 2010, and now dominates the market.

These new platforms led to the decline of earlier ones. When Microsoft, for instance, started a new OS from scratch, in the form of Windows Phone, Nokia abandoned Symbian and partnered with MS to use Windows Phone on its smartphones. Windows Phone then became the third-most-popular OS. Palm was bought by Hewlett-Packard, turned into webOS which became Open webOS and later sold to LG Electronics. Research in Motion also made a new system from scratch, BlackBerry 10.

The capacitive touchscreen also had a knock-on effect on smartphone form factors. Before 2007 it was common for devices to have a physical numeric keypad or physical QWERTY keyboard in either a candybar or sliding form factor. However, by 2010, there were no top-tier smartphones with physical numeric keypads.

The future

In 2013, the Fairphone company launched its first "socially ethical" smartphone at the London Design Festival to address concerns regarding the sourcing of materials in the manufacturing.

In late 2013, QSAlpha commenced production of a smartphone designed entirely around security, encryption and identity protection

In December 2013, the world's first curved-OLED technology smartphones were introduced to the retail market with the sale of the Samsung Galaxy Round and LG G Flex models. Samsung phones with more bends and folds in the screens are expected this year.

Foldable OLED smartphones could be as much as a decade away because of the cost of producing them. There is a relatively high failure rate when producing these screens. As little as a speck of dust can ruin a screen during production. Creating a battery that can be folded is another hurdle.

A clear thin layer of crystal glass can be added to small screens like watches and smartphones that make them solar powered. Smartphones could gain 15% more battery life during a typical day. The first smartphones using this technology should arrive in 2015. This screen can also work to receive Li-Fi signals and so can the smartphone camera. The cost of these screens per smartphone is between $2 and $3, much cheaper than most new technology.

Near future smartphones might not have a traditional battery as their sole source of power. Instead, they may pull energy from radio, television, cellular or Wi-Fi signals.

In early 2014, smartphones are beginning to use Quad HD (2K) 2560x1440 on 5.5" screens with up to 534 ppi on devices such as the LG G3 which is a significant improvement over Apple's retina display. Quad HD is used in advanced televisions and computer monitors, but with 110 ppi or less on such larger displays.

As of 2014, Wi-Fi networks are much used for smartphones. As Wi-Fi becomes more prevalent and easier to connect to, Wi-Fi phones service will start to take off.

Since 2013, water and dustproofing have made their way into mainstream high end smartphones instead of specialist models with the Sony Xperia Z continuing through the Sony Xperia Z3 and also from other manufacturers with the Samsung Galaxy S5.

One problem with smartphone cameras is still the focus, but LG G3 Beat with Laser Focus has 8 points of focus. To focus what appears in the LCD, touch the object on screen to focus on it and the other positions will be 'bokeh'.

Some smartphones can be categorized as high-end point-and-shoot cameras with large sensor up to 1" with 20 Megapixels and 4K video. Some can store their pictures in proprietary raw image format, but the Android (operating system) 5.0 lollipop serves open source RAW images.

Modular smartphones are projected, in which users can remove and replace parts.

Air conditioning

Air conditioning

Air conditioning (often referred to as A/C, AC or aircon) is the process of altering the properties of air (primarily temperature and humidity) to more comfortable conditions, typically with the aim of distributing the conditioned air to an occupied space to improve thermal comfort and indoor air quality.

In common use, an air conditioner is a device that lowers the air temperature. The cooling is typically achieved through a refrigeration cycle, but sometimes evaporation or free cooling is used. Air conditioning systems can also be made based on desiccants.

In the most general sense, air conditioning can refer to any form of technology that modifies the condition of air (heating, cooling, (de-)humidification, cleaning, ventilation, or air movement). However, in construction, such a complete system of heating, ventilation, and air conditioning is referred to as HVAC (as opposed to AC).

The basic concept behind air conditioning is said to have been applied in ancient Egypt, where reeds were hung in windows and were moistened with trickling water. The evaporation of water cooled the air blowing through the window. This process also made the air more humid, which can be beneficial in a dry desert climate. In Ancient Rome, water from aqueducts was circulated through the walls of certain houses to cool them. Other techniques in medieval Persia involved the use of cisterns and wind towers to cool buildings during the hot season.

Modern air conditioning emerged from advances in chemistry during the 19th century, and the first large-scale electrical air conditioning was invented and used in 1902 by American inventor Willis Carrier. The introduction of residential air conditioning in the 1920s helped enable the great migration to the Sun Belt in the United States.