Integ Prog

• Mobile Computing


  Technology that allows transmission of data, voice and video via a computer or any other wireless enabled device without having to be connected to a fixed physical link
• Main concepts of Mobile Computing

  • Mobile communication
  • Mobile hardware
  • Mobile software
• Mobile communication


  • Refers to the infrastructure put in place to ensure seamless and reliable communication, including devices such as protocols, services, bandwidth, and portals
  • Data format is defined to ensure no collision with other existing systems
• Mobile hardware


  • Mobile devices or device components that receive or access the service of mobility, such as portable laptops, smartphones, tablet PCs, PDAs
  • Devices are configured to operate in full-duplex, capable of sending and receiving signals at the same time
  • Devices use a wireless network to operate
• Mobile software


  • The actual program that runs on the mobile hardware, dealing with the characteristics and requirements of mobile applications
  • The operating system of the mobile device, the essential component that operates it
• Portability is the main factor of mobile computing, allowing users to operate from anywhere
• Android


  A mobile operating system based on a modified version of Linux, originally developed by a startup called Android, Inc. and later purchased by Google
• Google wanted Android to be open and free, so most of the Android code was released under the open-source Apache License
• Vendors can add their own proprietary extensions to Android and customize it to differentiate their products
• The main advantage of adopting Android is that it offers a unified approach to application development, allowing developers to create apps that can run on numerous Android-powered devices
• Android versions and codenames

  • 1.1
  • 1.5 (Cupcake)
  • 1.6 (Donut)
  • 2.0/2.1 (Éclair)
  • 2.2 (Froyo)
  • 2.3 (Gingerbread)
  • 3.0 (Honeycomb)
• Android features


  • Storage (SQLite)
  • Connectivity (GSM/EDGE, IDEN, CDMA, EV-DO, UMTS, Bluetooth, WiFi, LTE, WiMAX)
  • Messaging (SMS, MMS)
  • Web browser (WebKit, Chrome's V8 JavaScript engine)
  • Media support (H.263, H.264, MPEG-4, AMR, AAC, MP3, MIDI, Ogg Vorbis, WAV, JPEG, PNG, GIF, BMP)
  • Hardware support (accelerometer, camera, compass, proximity sensor, GPS)
  • Multi-touch
  • Multi-tasking
  • Flash support (Android 2.3)
• Android applications


  • Browser
  • Phone
  • Contacts
  • Home
• Android supports tethering, allowing sharing of Internet connections as a wired/wireless hotspot
• Android OS architecture


  • Linux kernel (low-level device drivers)
  • Libraries (provide main OS features)
  • Android runtime (Dalvik virtual machine, core libraries)
  • Application framework (exposes OS capabilities to developers)
  • Applications (pre-installed and user-installed)
• Android device types


  • Smartphones
  • Tablets
  • E-readers
  • Netbooks
  • MP4 players
  • Internet TVs
• The Android Market is an online application store for Android devices, allowing users to download both paid and free third-party applications
• Availability of paid applications on the Android Market is dependent on legal and regional restrictions
• Voice user interaction (VUI)


  A unique challenge for mobile developers, as it departs from traditional keyboard and touchscreen interfaces
• Challenges of VUI design

  • Understanding user expectations, as human communication has inherent context that computers struggle to compensate for
  • Explicitly communicating the capabilities and limitations of the voice recognition system
  • Providing clear visual feedback to indicate the system is listening
• Integrating VUI apps with conversational APIs like api.ai or Amazon's Alexa Skills Kit API is crucial for best performance
• Practices to avoid in Building VUI design

  • Not asking the user a question when the app expects a response
  • Not being clear about the user's options
  • Giving the user too many choices or being too verbose
  • Confirming the user's query too often
• Being clear about the user's options

  For example, "Which sport do you want scores for, football or basketball?" is a better question than "Do you want scores for football or basketball?", since the user might simply respond "Yes."
• Giving the user too many choices or being too verbose (for example, "Say 'football' for football. Say 'basketball' for basketball…") is not recommended
• Confirming the user's query too often is not recommended. Confirmations should be reserved for important actions such as sending a message or making a purchase
• Siri is one of the most successful examples of VUI (Voice User Interface) design, according to the above principles
• Siri virtual assistant


  • When users start Siri, they're presented with a list of ideas such as "Call Hannah" and "Play some rock music"
  • Siri provides both visual feedback (in the form of a glowing white line) and tactile feedback to let users know when it's listening
• Millions of Moms across the world have been called a little more often thanks to Siri's help
• Designing great VUIs isn't easy, but there's little doubt that voice interaction is the way of the future. As more and more users use voice-controlled virtual assistants and apps on their mobile devices, getting your VUI right will be ever more important
• Text-to-speech (TTS) synthesis


  The artificial generation of human voice – either in the form of speech or in other forms such as a song
• Speech synthesizer


  The computer system used for speech synthesis
• Types of speech synthesizers


  • Hardware based
  • Software based
• TTS (Text to Speech) system


  Converts normal language text into human speech
• Text-to-speech synthesis procedure

  1. Text analysis

  2. Generation of speech waveforms
• Quality of a speech synthesizer


  • Similarity to normal human speech (naturalness)
  • Intelligibility (ease of understanding by the listener)
• Front end


  Responsible for text normalization (the pre‐processing part) and text to phoneme conversion
• Back end


  Converts the symbolic linguistic representation of the text into sound
• Formant synthesis is based on the source-filter-model of speech
• Formant synthesis provides an infinite number of sounds which makes it more flexible than concatenation methods
• The PARCAS model uses a total of 16 control parameters