Daily Archives: February 6, 2021

Describe the researcher’s original results in terms of bias, precision, and accuracy.

11-2. A medical researcher carefully measures the length of the fetal

humerus in 50 ultrasound studies by using electronically generated

distance-measuring “calipers” on the display. The researcher

obtains a mean value of 5.5 cm with a standard deviation of 2 mm.

After the measurements have been obtained, the researcher discovers

through studies of excised bone that the electronically

generated caliper measurements are consistently 2% larger than

the true length.

a. Describe the researcher’s original results in terms of bias, precision,

and accuracy.

b. How can the mean and standard deviation of the original data

be corrected?

Compute the percent uptake of 131I in the thyroid gland.

 

11-5. A series of radioactive sample of short half-life will be counted

one per day over a period of several days. Explain how variations

in the observed counts caused by fluctuations in the sensitivity

of the counting system can be compensated.

12-1. The uptake of 131I was measured for a patient treated for hyperthyroidism

with the same radioactive nuclide 2 months previously.

The count rates were as follows:

For a 131I standard on day 0                                   13,260 cpm

For a 131I standard 24 hour later                            12,150 cpm

For the patient on day 0 before 131I                                    6,140 cpm

administered

For the patient 24 hours later                                12,840 cpm

Compute the percent uptake of 131I in the thyroid gland. Ignore

the contribution of background radiation to the count rates, but

include….

Describe a method with a radioactive nuclide to determine the volume of a large container

12-3. Describe a method with a radioactive nuclide to determine the

volume of a large container.

12-4. The following count rates were recorded 24 hours after administration

of 0.4 MBq of 131I to the patient:

For the patient’s thyroid 1831 cpm

For the patient’s thyroid shielded by a lead block 246 cpm

For a standard source in a thyroid phantom 3942 cpm

For a standard shielded by a lead block 214 cpm

What is the percent uptake?

 

What is the composite MTF of the system?

 

 

17-2. In a radiographic unit, would the cutoff frequency be higher or

lower on the anode side versus the cathode side of the x-ray

beam? Why?

17-3. A fluoroscopic imaging system has the following component

MTFs at 3 line pairs per millimeter: focal spot, 0.9; motion, 0.7;

input screen, 0.9; intensifier electronics, 1.0; output screen, 0.9;

optics, 0.9; and television system, 0.9. What is the composite

MTF of the system?

Create sample image maps of imperfect terrain; NASA will send you detailed VERMIN maps once your firm has demonstrated the capabilities of its CATs.

NASA has given you the task of writing a really fast image-recognition program, fast enough that a Venusian CAT (Commercial Access Transport) is able to capture touchdown sites from topographic images made by the VERMIN satellite (VEnusian Radar Imaging and Networking satellite) while passing over the mapped area at a speed of 1000 km/hour. The VERMIN image maps are of a 5 km × 5 km area and have 0.5 m resolution both horizontally and in altitude. Appropriate landing sites are areas in which there is a 1.5 m maximum altitude variation within a 25 m circle. (Fairly large and relatively flat areas are needed for the CAT to land gracefully.) Create sample image maps of imperfect terrain; NASA will send you detailed VERMIN maps once your firm….

write a parallel program using realistic test images. For interest, read Mandeville (1985).

A manufacturer of printed circuit cards is having significant problems with broken printed circuit tracks on its boards and has commissioned you, as an independent programmer, to find a way to inspect images of the boards automatically as they leave the manufacturing line and recognize broken tracks. You know that all the tracks are straight in one direction or can turn 90 degrees to that direction. Develop a strategy for recognizing the break in the tracks and write a parallel program using realistic test images. For interest, read Mandeville (1985).

explain the role each plays.

Tom’s favorite activity is putting together 1,000-piece puzzles (odd, but uniquely shaped cardboard pieces that are die-cut from a single complete scene). Using shape and coloration as cues, Tom picks up two pieces and tries to fit them together, possibly rotating one or the other. Sometimes Tom misjudges, and the two pieces don’t fit together properly; he then has to put the two pieces back on the board and try again. When they do fit together, Tom places them on the board, where they are then considered to be a single piece. Tom then repeats the process. Since developing an interest in computer science in general, and parallel programming in particular, Tom has rigged up a video camera over a small table on which he has spread all….

Write a parallel program to solve the 8-queens problem; that is, find all the positions of eight queens on an 8 × 8 chessboard such that no two queens can attack each other (not on the same column or diagonal).

Write a parallel program to solve the 8-queens problem; that is, find all the positions of eight queens on an 8 × 8 chessboard such that no two queens can attack each other (not on the same column or diagonal). Since each queen must be placed on a different row of the chessboard, each solution can be represented by the column position of each queen; that is, an 8-tuple (x1, x2,… , xi , …, x8), where xi is the column position of queen i. The constraint of xi is1 ≤ xi ≤ 8. Also note that two queens at positions (a, b) and (c, d) cannot be on the same diagonal if a − b = c − d or a + b = c + d.

write a parallel program to position the rectangles in a large rectangle, subject to the conditions that 1.

Given a set of rectangles in which the area of the ith one is given by Ai , write a parallel program to position the rectangles in a large rectangle, subject to the conditions that 1. The individual rectangles must not overlap, 2. All n smaller rectangles must be included in the large one, and 3. The area of the larger one is to be a minimum. (Note: This is a simplified version of the problem of laying out an integrated circuit. The more complex layout problem has more conditions related to relationships between the smaller rectangles.)

. Write the program, developing suitable input data and constraints. One constraint is the number of hubs.

Nat-Ex, a nationwide parcel delivery company, is reassessing the placement of its hubs that collect and distribute parcels. Ideally, the hubs should be situated at strategic places across the country to minimize costs and delivery times. You have been commissioned to make a study of possible alternative sites for the hubs and decide to write a parallel program based upon genetic algorithms. You assume that the number of parcels being received is directly proportional to the population, and for a first approximation only the major cities are considered. Write the program, developing suitable input data and constraints. One constraint is the number of hubs.