Comp 595MC/L: Mobile Computing CSUN Computer Science Department Fall 2013 Midterm

Transcription

1 Comp 595MC/L: Mobile Computing CSUN Computer Science Department Fall 2013 Midterm Time: 50 minutes Good news: You can use ONE sheet of notes. Bad news: Closed book, no electronic computing or communications devices. Name: Student ID: Question Points Grades Total 100 Computing is not about computers any more. It is about living. - Nicholas Negroponte

2 Question 1: Multiple Choice Circle the best option for each question below. a) Which is the correct way to create and display a Toast? A) Toast.makeText(this, Hello, Toast.LENGTH_SHORT); B) Toast t = new Toast( Hello ); C) Toast.makeText(this, Hello,Toast.LENGTH_SHORT).show(); D) Toast.create(this, Correct Answer, Toast.LENGTH_LONG).display(); b) How you get access to a TextView, named tview, in your XML file? A) TextView t = (TextView) getviewbyid(tview); B) TextView t = (TextView) findviewbyid(r.id.tview); C) TextView t = findviewbyid(r.id.tview); D) TextView t = getviewbyid(tview); c) Which is the function that will be called when your resulting activity catches an Intent? A) onreceive(context context, Intent intent) B) oncreate(bundle b) C) onresume() D) onstart(context context, Intent intent) d) Which called is used to get a handle on the GSP provider? A) Context.getSystemService(Context.LOCATION_SERVICE); B) Context.getLocationService(); C) Context.getSystemService(GPS_PROVIDER); D) Context.getGpsService(); e) Which activity lifecycle method will be called before Activity2 starts, assuming an app is already running an Activity called Activity1 and Activity1 starts another Activity called Activity2. A) oncreate B) onstart C) onresume D) onpause E) onstop F) Both D and E 2

3 Question 2: Very Short Answer Questions Give very brief (mostly one or two word answers) to each of these very short questions. a) A device that measures a physical quantity and converts it into a signal. b) Name the XML schema designed to serve as a common GPS data format that we worked with in lab. c) What types of radiation did MIT s Cricket system use for localization? d) Name two types of Views in Android. e) A Monte Carlo method for representing position probability distributions with a collection of individual samples f) In what unit is the light value reported? g) In what unit is the accelerometer value reported? h) If your signal strength is 100 and you are 1 meter from the base station, what is your signal strength when you are 2 meters from the base station? Recall that signal attenuation is proportional to 1/distance 2. i) Name two different map APIs. j) A device that accepts energy and produces movement or some action. 3

4 Question 3: Short Answer Questions a) What is the difference between a raw sensor and a composite sensor? Name an example of each on your mobile device. b) Recall the upgrade from 0G mobile phone technology to 1G. What improvements did 1G have over 0G. Name a disadvantage of 1G over 0G. c) Electromyography (EMG) involves electrical activity produced by skeletal muscles EMG data are below 500 Hz, Explain the sample rate you would choose and why. 4

5 Question 4: Sketch Given the following outline of a XML layout file, sketch what the layout generated from this code would look like.... <LinearLayout... > <Button android:text="button1" android:layout_height="wrap_content" android:layout_gravity="center" android:layout_width="wrap_content"...> <LinearLayout android:layout_height="wrap_content" android:layout_width="match_parent"... > <Button android:text="button2" android:layout_height="wrap_content" android:layout_gravity="center" android:layout_weight="1" android:layout_width="0dp"... > <Button android:text="button3" android:layout_height="wrap_content" android:layout_gravity="center" android:layout_weight="1" android:layout_width="0dp"...> </LinearLayout> <Button android:text="button4" android:layout_height="wrap_content" android:layout_gravity="center" android:layout_width="fill_parent"...> </LinearLayout> 5

6 Question 5: Localization You are given a mobile phone with the following sensors: (1) camera, (2) accelerometer, (3) GPS, (4) microphone. You are allowed to use only two of the above four sensors. Design a localization technique that uses the above two sensors and derives the absolute location (i.e. latitude, longitude) indoors and outdoors. 6