Final 2018 PDF

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Summary

Exam Question PaperCollege/ Institute College of Engineering, Design and Physical SciencesDepartment Mechanical and Aerospace EngineeringExam Author(s) Dr Gera TroisiModule Code ME 3601Module Title Professional Engineering PracticeMonth May Year 2018Paper Type FULLDuration 2 HoursQuestion Instructio...

Description

Exam Question Paper College/ Institute Department

College of Engineering, Design and Physical Sciences Mechanical and Aerospace Engineering

Exam Author(s)

Dr Gera Troisi

Module Code

ME3601

Module Title

Professional Engineering Practice

Month Paper Type Duration

Question Instructions

Are Calculators Permitted?

May

Year

2018

FULL 2 Hours

Answer ALL questions

Yes

Permitted Reference Materials

None

Required Stationery

Use a separate answer book for each Section

SECTION A

Question 1.

(a) Use a well-annotated flow diagram to describe the process involved in Risk Management, describing briefly what each step involves, citing the relevant international standards (ISOs). [35%]

(b) Use a well-annotated flow diagram to describe the process for executing a life cycle assessment (LCA), describing briefly what each step involves, citing the relevant international standards (ISOs). [35%]

(c) Propose a “best practice” approach to managing environmental, quality, health and safety risks in the manufacturing sector and recommend tools you would deploy to assess these risks. Where applicable cite relevant guidance and ISO standards. [30%]

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Question 2. (a) Using the fault tree (FTA) in Figure 1, answer the questions that follow. Show your calculations: (i) List all the minimum cut sets for the FTA and their probabilities of occurring? [40%] (ii) What is the probability of the top event occurring? [5%] (iii) Name relevant risk management principles that could be applied to decide appropriate mitigation action without compromising on profitability? On this basis, which cut set(s) would be prioritised? [5%] (b) Figure 2 shows an incomplete event tree (ETA) analysis of safety features to mitigate dangerous build-up of pressurised methane resulting from a pipe blockage. Complete the ETA to answer the questions that follow. Show your calculations: (i) What are the possible consequences and how likely are each of these to occur per year? [45%] (ii) What is the total annual occurrence of system failure and total annual occurrence for system success, respectively? [5%]

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Figure 1. Fault Tree for methane loading line pressured by 2 pumps

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Safety Components Failure probability:

Pressure Sensor

Back-up Pressure Sensor

Relief Valve Relay

Relief Valve

0.01

0.01

0.001

0.003

Initiating Event 15 blockages/year

Figure 2. ETA to mitigate pipe blockages in a methane delivery system. -4-

Consequences

SECTION B All questions in Section B carry equal marks with a maximum score of 28 marks [100%]. **For all questions assume a 0.05 significance level** Question 1 The maximum speed of a vehicle is an example of: a) a nominal categorical variable b) an ordinal categorical variable c) an interval continuous variable d) a ratio continuous variable Question 2 The region of manufacture of a vehicle is an example of: a) a nominal categorical variable b) an ordinal categorical variable c) an interval continuous variable d) a ratio continuous variable Question 3 When investigating the relationship between the weight of a car and its acceleration: a) the weight is the dependent variable and acceleration is the independent variable b) the weight is the independent variable and acceleration is the dependent variable c) both the weight and acceleration are independent variables d) both the weight and acceleration are dependent variables Question 4 Given a statistical test and a p-value of 0.36, we would: a) reject the null hypothesis b) accept the null hypothesis c) fail to reject the null hypothesis d) accept the alternate hypothesis Question 5 Given a statistical test and a p-value of 0.04, we would: a) reject the null hypothesis b) accept the null hypothesis c) fail to reject the null hypothesis d) reject the alternate hypothesis

Questions 6 to 8 relate to the data in Figure 3. Question 6 Which of the following statements is accurate? a) We are 95% sure that the true mean of the sample is between 17.4 and 19.72 b) We are 5% sure that the true mean of the sample is between 17.4 and 19.72 c) We are 95% sure that the true mean of the population is between 17.4 and 19.72 d) We are 5% sure that the true mean of the population is between 17.4 and 19.72 -5-

Question 7 Which of the following is true? (a) We have 100 cases in our sample, 5 of which are missing information regarding mpg (b) We have 100 cases in our sample, all of which are missing information regarding mpg (c) We have 100 cases in our sample, none of which are missing information regarding mpg (d) We have 80 cases in our sample, none of which are missing information regarding mpg Question 8 Which of the following statements, regarding mpg data, is not true? a) Case number 28 is an outlier b) The data is negatively skewed c) The difference between the 75th percentile and 25th percentile is 8 d) The mean is greater than the median

Questions 9 to 16 relate to the data in Figure 4.

Question 9 In this sample: a) there were more cars produced in U.S., and they had a higher standard deviation b) there were more cars produced in U.S., and they had a lower standard deviation c) there were fewer cars produced in U.S., and they had a higher standard deviation d) there were fewer cars produced in U.S., and they had a lower standard deviation Question 10 Based on the t-test we can state that: a) There is no statistically significant difference in mpg between cars produced in the U.S. and those not produced in the U.S. b) There is a statistically significant difference in mpg between cars produced in the U.S. and those not produced in the U.S., and the mpg was lower for U.S. manufactured cars c) There is a statistically significant difference in mpg between cars produced in the U.S. and those not produced in the U.S., and the mpg was lower for non-U.S. manufactured cars d) There is zero chance that there is a difference between U.S. and non-U.S. cars Question 11 Which of the following is true? a) The 5% confidence interval of the difference does not contain the value of zero, this shows that there is a statistically significant difference between the means of mpg. b) The 95% confidence interval of the difference does not contain the value of zero, this shows that there is a statistically significant difference between the means of mpg. c) The 95% confidence interval of the difference does contain the value of zero, this shows that there is a statistically significant difference between the means of mpg. d) The 95% confidence interval of the difference does not contain the value of zero, this shows that there is not a statistically significant difference between the means of mpg.

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Question 12 Based on the data in Figure 4, how many pairs of variables have statistically significant correlations? a) 1 b) 3 c) 6 d) 9 Question 13 The significance level shown for the correlation between weight and horsepower: a) = 0 b) = 1 c) < 0.01 d) > 0.01 Question 14 Which of the following describes the relationship between weight and horsepower? a) There is a statistically significant, strong, positive association b) There is a statistically significant, weak, positive association c) There is a statistically significant, strong, negative association d) There is a statistically significant, weak, negative association Question 15 Which of the following describes the relationship between weight and mpg? a) There is a statistically significant, strong, positive association b) There is a statistically significant, weak, positive association c) There is a statistically significant, strong, negative association d) There is a statistically significant, weak, negative association Question 16 The correlation coefficient between horsepower and mpg is -0.808, based on this we can state: a) Higher horsepower causes lower mpg b) Higher horsepower causes higher mpg c) Higher mpg causes lower horsepower d) There is a negative association between horsepower and mpg Questions 17 to 20 relate to the data in figure 5. Question 17 The model in figure 5 explains: a) 90.4% of the variance in mpg b) 0.904% of the variance in mpg c) 81.7% of the variance in mpg d) 0.817% of the variance in mpg

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Question 18 The model in figure 5 shows: a) horsepower is a statistically significant predictor of mpg, whereas weight is not b) weight is a statistically significant predictor of mpg, whereas horsepower is not c) Both weight and horsepower are statistically significant predictors of mpg d) Neither weight nor horsepower are statistically significant predictors of mpg Question 19 From the model in figure 5, the value of ‘a’ in the linear regression model Y = a + bX, is: a) 36.634 b) 0.930 c) 39.393 d) 2.544 Question 20 The model in figure 5 “proves” that more horsepower makes engines have lower mpg. a) True b) False c) This cannot be determined given the information provided d) None of the above

Questions 21 to 24 relate to the data in Figure 6. Question 21 Which of the following statements regarding model in figure 6 is NOT true? a) It explains less of the variance in mpg than model 1 b) It models the effect of weight on mpg c) The lower R square means it is a worse model than model 1 d) It explains more than 80% of the variance in mpg Question 22 Based on the model in figure 6, the value of ‘b’ in the linear regression model Y = a + bX, is: a) 36.737 b) 0.907 c) -0.012 d) 0.001 Question 23 Based on the Model in figure 6, which of the following is true? a) that heavier cars will achieve lower mpg b) that heavier cars will achieve lower mpg c) that heavier cars will achieve higher mpg d) that heavier cars will achieve higher mpg

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Question 24 Model 2 indicates that: a) Increased weight is associated with lower mpg b) Increased weight is associated with higher mpg c) Increased weight is associated with no significant difference in mpg d) Increased weight is the only variable that affects mpg

Questions 25 to 27 relate to data in Figure 7. Question 25 Model 3 indicates that: a) there is a statistically significant relationship between a car being U.S. made and mpg, and that U.S. cars achieve lower mpg b) there is a statistically significant relationship between a car being U.S. made and mpg, and that U.S. cars achieve higher mpg c) there is a statistically significant relationship between a car being U.S. made and mpg, and that non-U.S. cars achieve lower mpg d) there is not a statistically significant relationship between a car being U.S. made and mpg Question 26 Based on model 3, predicted mpg for an U.S. manufactured car weighing 1,000kg is: a) 23.2 mpg b) 33.2 mpg c) 35.8 mpg d) 43.2 mpg Question 27 Based on the model in figure 7, predicted mpg for a non-U.S. manufactured car weighing 800kg is: a) 25.2 mpg b) 27.8 mpg c) 35.8 mpg d) 43.8 mpg Question 28 Which of the following is a consideration when modelling relationship using regression analysis? a) Substantive reasons for the inclusion of variables b) Possible inter-correlation of independent variables c) Possible interactions between independent variables d) All of the above

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Figure 3. Univariate analysis of fuel efficiency (miles per gallon or mpg) of cars manufactured between 1970 and 1974.

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Figure 4. Results of a Bivariate analysis of fuel efficiency (mpg) of cars manufactured between 1970 and 1974

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Figure 5. Multivariate analysis (model 1) of fuel efficiency (mpg) of cars manufactured between 1970 and 1974.

Figure 6. Multivariate analysis (model 2) of fuel efficiency (mpg) of cars manufactured between 1970 and 1974. -12-

Figure 7. Multivariate analysis model (model 3) of fuel efficiency (mpg) of cars manufactured between 1970 and 1974.

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