Kĩ thuật lập trình - Personal technology

1Personal Technology7.1 Convergence, Portability, & Personalization7.2 MP3 Players7.3 High-Tech Radio7.4 Digital Cameras: Changing Photography7.5 Personal Digital Assistants & Tablet PCs7.6 The New Television7.7 Smartphones: More than Talk7.8 Videogame SystemsChapter7McGraw-Hill/Irwin© 2007 The McGraw-Hill Companies, Inc. All rights reserved.Convergence, Portability, & PersonalizationDigital Convergence Describes the combining of several industries – computers, communications, consumer electronics, entertainment, and mass media – through various devices that exchange data in digital formPros:Multiple use machines such as Xbox that can play games, display DVD movies, and play music CDsCellphones with enhancing features such as address books and digital cameras that also shoot videosCons:Multiple features that compromise the primary feature, such as an internet refrigerator3Convergence, Portability, & PersonalizationPortabilityProsDevices that enable phone and email access from anywhere, portable digital music, and convenient cheap digital photos allow people to remain connected even while on the moveConsYour boss may expect you to answer e-mail and voicemail evenings and weekendsPeople whom you never meet in person may misrepresent themselves, and/or misunderstand you, since they don’t see your body languageDiscussion Question: Have you experienced any of these problems? How did you handle it?4Convergence, Portability, & PersonalizationPersonalizationTree-and-branch telecommunications model A centralized information provider sends out messages through many channels to thousands of consumersUsed by AM/FM radio and by TV broadcastersHard to personalizeSwitched-network communications modelA common carrier provides circuit switching that creates a temporary two-way connection between one public user and anotherIn a telephone network, the connection is made by dialingPersonalized by default5Convergence, Portability, & PersonalizationChoice OverloadDescribed by Barry Schwartz, author of The Paradox of Choice: Why More is LessPeople are unhappy when they have too many choicesRegret: People are more likely to regret their decisionsInaction: People can’t decide now because they might later regret their decisionsExcessive Expectations: Reality has a hard time meeting the expectations when there are so many choicesSelf-blame: People blame themselves for making the wrong decisionDiscussion Question: How many of you have put off buying a computer or other item because the price might come down or a better one might come out?6Convergence, Portability, & PersonalizationPopular personal technologiesMP3 audio playersSatellite, high-definition, and internet radiosDigital camerasPersonal digital assistants and tablet PCsSmartphonesHigh-definition TVVideogame systems7MP3 PlayersMP3 is a format that allows audio files to be compressed so they are small enough to be sent over the internet or stored as digital filesMP3 players are portable devices that play MP3 filesVendors includeApple iPod (market leader)Archos, Creative, Dell, iRiver, Panasonic, RCA, Samsung, Sandisk, Sony, Virgin ElectronicsStorage methodsHard drive storage (holds more, costs more)Flash storage (holds less, costs less)8MP3 PlayersTechnology ConsiderationsStorage capacitySampling rateTransferring filesBattery lifeColor screens and photo viewingOther features such as FM radio receptionMusic recording using extra microphoneCar stereo adapter to connect player to your car’s speakers9MP3 PlayersSocietal EffectsOne in ten American adults owns an MP3 playerOne in five American adults under 30 owns oneOffer convenience and portability to music listenersWarning! Over 85 decibels can cause hearing loss!85 decibels is as loud as a vacuum cleaner or a crowded restaurant – not that loud!For more information, see lhh stands for the “League for the Hard of Hearing”So turn them DOWN!10High-Tech RadioSatellite radioDigital radio signals are sent from satellites in orbit around the earth to subscribers that have special radiosCD-quality sound is better than normal radioMore channels than regular radioSDARS providers areXM satellite radioSirius satellite radioCommercial-free11High-Tech RadioHigh-Definition RadioProvides CD-quality soundStandard allows two digital and one analog station on the same radio frequencyAnalog main channel plus two digital sidebandsBroadcasting’s answer to competition from satellite radioRequires an HD-compatible radioL.A. and Chicago now have 10 high-definition stations each12High-Tech RadioInternet RadioInternet users can listen to radio from their PCsThere are some services such as Yahoo’s Musicmath that require users to subscribeOther internet radio may be free, such as WMNR, a Fine Arts radio station that also broadcasts from Monroe CT at 88.1 FM www.wmnr.orgTo see a list of free internet radio stations, visit www.live365.com 13High-Tech RadioPodcastingInvolves the recording of internet radio or similar internet programsRequires no studio or broadcast tower and is not regulated by the FCC (Federal Communications Commission)Allows amateur deejays and hobbyists to create their own radio shows14Digital CamerasCameras that take photographs but do not require filmVery competitive field with many new product releasesTypes to considerPoint-and-shoot digital cameraAutomatically adjusts settings such as exposure and focusEasy to use, but manual controls can allow you to tweak the settings to get better photos ($197 - 600)Single-lens reflex (SLR) digital cameraUses a reflecting mirror to reflect the incoming light so the viewfinder shows what the lens is framing ($789 - $1,148)15Digital CamerasResolutionMeasured in megapixels, or millions of picture elementsMeasure the maximum resolution of an image taken by the cameraImportant if you plan to enlarge your photos – more is betterLensesDigital zoomMeans the image is cropped in the cameraCan produce a grainy photoOptical zoomEnlarges the subject without you needing to move closerLens extends to focus on distant objectsStorageUses flash memory cards128 megabyte card holds 80 images from a 3 megapixel camera, while 1 gigabyte holds about 600 still images16Digital CamerasSelecting which photos to take and keepOptical viewfinders let you see the image to be photographed before you snap the pictureLCD screens let you review the photos you takeStart-up timeDigital cameras require time to start upLook for one that has a short start-up timeAlso, the shutter can lag and delay the time between when you press the button and the shutter clicksLook for a camera that allows “burst” or “continuous “ mode17Digital CamerasBattery lifeThe camera requires a battery to functionSome rechargeable batteries are available with many modelsSome recharge in the camera, while others require a separate charging standVideo clipsMost digital cameras can shoot movies, too1-gigabyte memory cards can shoot as many as 44 minutes of video at 30 frames per second18Digital CamerasPrinciple methods for transferring imagesUse a direct connection between your camera and your PC. Requires you to install software on the PCInsert the memory card into your PC’s USB portPut your camera into a cradle attached to the PCUse a photo printer with a built-in card slotUse a portable CD burnerUse an MP3 playerUse a photo-printing kioskUse a photo labBring along your own card reader and use others’ computers19PDAs and Tablet PCsThese are both small computersPDAsHave touch-sensitive screens so you can enter data with a stylus by tapping or writing on screenStore data in RAM that stays on even when the unit is off by using the PDA’s batteryCan be augmented by flash memoryCommonly use lithium ion batteriesTransfer files to your PC in one of three waysPull out the PDAs flash card and insert it into the PC’s card reader using a USB portPut your PDA into a special cradle plugged into a USB portTransfer data wirelessly20PDAs and Tablet PCsMany cellphones are usurping features from PDAsTo compete, PDAs must develop new featuresExamples of possible PDA evolutionDisplay television and photosHandheld weather metersGPS locators21PDAs and Tablet PCsTablet PCsA special notebook computer with a digitizer tablet and a stylus so the user can handwrite input from the screenRecently only about 1% of laptops being soldUsed in niche markets such as schools22The New TelevisionNew uses for TVInteractive TVPersonalized TVInternet TVSmart TVEntertainment PCs23The New TelevisionThree kinds of TVDigital televisionFCC has mandated that all TV stations be capable of digital broadcasting by 2006Currently most digital systems convert analog broadcast signals into digital with some loss of detailHigh-Definition television (HDTV)Works with digital broadcasting signalsHas broader screen and 10 times the pixels as standard TVHas 16 to 9 aspect ratio and 1,080 lines on a screen; crisper details than SDTVStandard-Definition television (SDTV)Has aspect ration of 4 to 3 and 480 vertical lines on a screenRequires less bandwidth to transmit than HDTV24The New TelevisionSocietal EffectsVideo on DemandTechnologies allow viewers to select videos or programs from a central server to watch when they wishTiVoPC-like system that allows users to record and play back TV programs laterUsers can program recording based on TV program title or subject matter without knowing specific stations or timesTiVos are plugged in to phone lines when they are installed so they can automatically update their softwareTiVos also gather information on subscribers’ viewing habits that are used to rate popularity of TV shows25SmartphonesCellular telephones with microprocessor, memory, display screen, and built-in modemOffer the following featuresText messagingCamerasMusic playersVideogames that can be downloaded and self-installedE-mail accessDigital TV viewingSearch toolsGPS locators26SmartphonesBasic elements of a mobile phoneStorageData is stored in ROMData does not disappear when phone is turned offInputHave a keypad for storing numbersMicrophone for picking up your voiceMay have a touch-sensitive screen that uses a stylusOutputSpeaker to hear voice callsDisplay ranging from LCD to full-color high-resolution plasmaMay also use Wi-Fi or Bluetooth27SmartphonesServices continuedText messagingCan send text to other phones and to email accountsCreating messages is slower than traditional Morse Code used by Ham Radio operators as demonstrated on the Tonight Show with Jay Leno on May 13, 2005 Downloaded ringtonesRingtone: the audible sound a phone makes to announce an incoming callMay be free or cost $1.25 to $4.00 per tune28Videogame SystemsThese may be the “ultimate convergence machine”People buy them to play games, but they do a lot moreXbox 360Sony PlayStation 3Nintendo Revolution29Videogame SystemsDifferent childhoods for generations in the USG.I. Generation (World War II)No computers, no TVs. Saw newsreels in the moviesBaby Boomers (post-World War II)No computers, black and white TVs, TV newsGeneration X (post-hippies, born post-1965)Some computers, color TVsGeneration Y (born in late 1970s to 1990s)Home computers, color TVsAlways On GenerationComputers everywhere, video games everywhere, always connected, internet newsDiscussion Question: Which generation are you? What is gained/lost?30