Electrical Engineering homework help

Electrical Engineering homework help. EE502 HW # 5 -COMPUTER INTERFACES AND COMMUNICATION AIDS
(This is a major HW assignment that will 8% toward the course grade. Due 04/13/2020)
Part I – Textbook & Reader Questions: From the Cook & Polgar text, answer questions – Chapter 11 # 3, 13, 23; From the
EE502 Course Reader B – Chapter 5 (“Rehabilitation Engineering & Assistive Technology”), answer questions # 6 & 12 on pp.
36-37 of the Course Reader.
Part II – Supplemental questions:
1. (10 pts.) AAC devices offer visual and/or auditory outputs. List the advantages and disadvantages associated with
these two modalities for interpersonal conversation. Assume that the visual output produces alphanumeric characters
(not icons) that are printed on paper or shown in a visual display.
2. (15 pts.) The DynaWrite, DynaVox Maestro, NOVA Chat 7 from Saltillo, and the TechSpeak 32 (all available at the
UCP AT Lab) represent dedicated communication aids designed to meet different disabilities and needs. Compare in
a table the key features of these devices: display type & size, motoric and sensory capabilities required, cognitive
abilities (read, write, spell, or word recognition?) needed, device’s weight & physical dimensions, customization
options, available input options (switch, joystick, keyboard, head pointer), available output options (visual or auditory?
synthesized or recorded speech?) , message acceleration features, range and resolution of motion required of the user,
and the ability to interface with other AT or computing devices. Be as specific and complete as possible. Hint: This
information is readily available from the website of their manufacturers.
3. (10 pts.) List and give examples of THREE encoding methods used in AAC devices to increase the communication
rate. Give advantages and disadvantages of each. What are the major approaches used to increase conversational rate
when the scanning is used? (Hints: See pp. 230-232 Course Textbook by Cook et al. This question is similar
questions 18 & 22 on p. 404 of Cook et al.)
4. The major difficulty with scanning aids is the speed of communication. It is possible to increase speed through careful
placement of letters in an array. You are to design and analyze a general purpose communication device that does
row-column scanning as follows: two switch activations are needed to select a particular item in the array; the dwell
time at each row or column is 1.5 sec; and the scan automatically resumes at the top row after each selection.
a) (12 pts.) Draw the array for two possible 8 X 8 arrangements of letters — the alphabetical and the frequency of
occurrence (as per Fig. 1 & 2). Fill-in all remaining spaces AFTER the single letters with punctuation marks,
numbers, letter groups and/or frequently used words (as per Fig. 3). Assume that numbers, periods, & commas each
have a usage weighting factor of Wi = 0.001 (or 0.1%). Be sure to give your rationale for your choice & placement of
words, letter combinations, or numbers. Include ‘SPACE’ in your array and assume a usage factor of Wi
= 0.15 (15%)
for it. Use only Fig. 3’s letters groups or words.
b) (12 pts.) For both arrangements of your 8 X 8 array scanned in a row-column manner, calculate the total time using
single letters (i.e., sum of scanning steps needed to reach the letters/spaces in a message times the dwell time) needed
to generate the phrase: I want to go to Sea World
c) (16 pts.) For both 8 X 8 layouts, calculate the average selection time (Tave) using the
following equation where n equals the total number of cells in the layout, Wi is the
frequency of usage weighting factor (see data tables on backside) of the i
th vocabulary
element, Si
equals the number of scanning steps needed to reach the i
th vocabulary
element (and thus layout dependent), and to
is the presentation or dwell time (1.5 sec) for each vocabulary element.
For both layouts, calculate the final results for Tave (by hand or using Excel).
5. (CANCELLED) UCP LAB EXERCISE: do a quantitative comparison of the relative speed of various input options
‚ DynaVox-V or Vmax using a head pointer (illustrating random access) with and without word prediction.
‚ DynaVox-V or Vmax using single switch input (illustrating automatic row-column scanning) with & without word
prediction.
‚ DynaVox-V or Vmax using a joystick (illustrating 2-D directed input) with and without word prediction.
‚
Use these different input methods to generate the following phrase – “the quick grey fox jumped over the lazy brown
dog.” Compare the time needed to produce an errorless voice output (include the time needed for error correcting) when using
the same AAC device. Note how many and the types of errors made with each type of inputs method. It’s most efficient to do
this exercise by working in pairs and timing each other. These AAC devices are available at the UCP’s Assistive Technology
Lab (8665 Gibbs Drive, Suite 100, San Diego, CA 92123). The UCP AT Center Director has kindly offered to make other
times available for this lab activity, but please call the AT Center at 858-278-5420 x 121 to make an appointment.
Figure 1. Frequencies of English character double letter combinations from 10,000 letters in a literary text. The first
letter of the double letter is given in rows and the second letter is given in columns. The weighting factor of each
vocabulary element can be found by dividing by 10,000.
Figure 2. Frequency of single
English letter usage from 10,000
letters. Weighting factors can be
calculated by dividing the
frequencies by 10,000.
Figure 3. Frequency of English letter combinations
from 25,000 letters of a literary text. The weighting
factors for the letters and words can be calculated by
dividing the frequencies by 25,000 and 242,432,
respectively

Electrical Engineering homework help