# Week 8 Questions and Answers

“10.14 A 1600-pixel by 900-pixel display is generated on a 14-inch (diagonal) monitor.

a.    How many dots per inch are displayed on this monitor?
b.    What is the size of an individual pixel? Would a 0.26mm pixel resolution
monitor be sufficient for this display?
c.    Repeat (a) and (b) for a 1280 × 720 display.”
(Englander 331)

How many dots per inch are displayed on this monitor

1600 by 900pixels with a 14inch Diagonal Monitor

D=Diagonal pixels ; horizontal =x; Vertical =y

D2= x2+y2

D= ( x2+y2)

= (1600*1600)+ (900*900)

D= 2560000+810000= 3370000 = 1835.8

D=1835.8pixels

Therefore the Dots per inch would be 1835.8/14=131.13dpi

What is the size of an individual pixel? Would a 0.26mm pixel resolution
monitor be sufficient for this display?

25.4mm is equal to an inch.

Size of Individual Pixel = 25.4/131.13=0.1937pixels per mm

No as the pixels are bigger and would require 25.4/.26=97.69dpi

If 1600*900pixels gives a diagonal of 1835.8pixels

Therefore the diagonal would be for 0.26mm pixel= 1835/97.60=18.8 inch= 19inch monitor

Repeat (a) and (b) for a 1280 × 720 display.”

D2= x2+y2

D= ( x2+y2)

= (1280*1280)+ (720*720)

D= 1638400+518400= 2156800 = 1468.6

D=1468.6pixels

Therefore the Dots per inch would be 1468.6/14=104.9dpi

Size of individual pixel = 25.4/104.9=0.2421mm pixels. Therefore a 0.26 mm pixel monitor would not fit so No

3.

Please respond to the topic by searching the web for a description of a biometric security peripheral. Comment on your perception of the device’s ability to accurately identify the user.

The Biometric security peripheral even though a new technology for the measurement of biological identity of a person based on their face, fingerprint, hand geometry, retina, iris, voice, signature and vein! It is remarkable on how a simple device has helped Nigeria in the last elections eliminate multiple and false recording of voters. Even though it was not used fo the voting directly (legal implications), but to validate registered voters, it drastically reduced lots of voting fraud, Though it was not so effective in determining under aged voters, it sure helped to present a more credible result for the electorate.

http://www.punchng.com/politics/2015-elections-an-x-ray-of-inec/

The demise of magnetic tape as a storage medium has been predicted many times.  Use the Web to find the state-of-the-art in tape system capacity and speed.  Why are people still buying these tape drives?

Magnetic tape is relatively very secure and reliable. Has large storage capacity as well with significantly lower costing. The investment is significant and works primary in government agency with strong policies of maintaining the “order” rather than any significant good. Secondly, several applications running on large mainframes with significant budgets could not be written off unless they have been fully depreciated based on valuation principles earlier established. Example In 2014 Sony and IBM announced that they had been able to record 148 gigabits per square inch with magnetic tape media developed using a new vacuum thin-film forming technology able to form extremely fine crystal particles, allowing true tape capacity of 185 TB.

https://en.wikipedia.org/wiki/Magnetic_tape