Readings

Chapter 3: Design & Teamwork

Design:

• Design is a creative process produced to show the look and function of each part of the object. 

ABET Design Approach:

• Accreditation Board for Engineering and Technology
• Established in 1932 as the Engineers Council for Professional Development.
• Currently ABET accredits some 2700 programs at more than 550 colleges and universities nationwide. 
• assurance that a college or university program meets the quality standards established by the profession for which it prepares its students. 

Stakeholders:

• Problems and needs are best identified and defined with their help

Defining The Problem:

• In engineering, a problem or need may be provided by a client or by an employer, where certain basic decisions about the design pathway have been made before the engineer makes any decisions.
• Example: If an engineer was asked to design a process by which the asbestos in a school boiler room can be removed. the engineer could choose from multiple ways to define the problem-removing the asbestos , containing it, increasing airflow and filtration to ensure that any loose particulate is swept away and captured. 
• Must: something that should not be missed or overlooked
• Should: something that is expected

Brainstorming Section 3.4:

• More is better
• Variety is better
• Do not criticize
• Where ideas are generated
• LEED: Leadership in Energy and Environmental Design

Making Decisions:

• Each proposed solution must be evaluated against those criteria. 
• Eliminate any solutions that do not meet the minimum  requirements
• Voting is a quick way to reduce a large number of choices to a smaller number of choices
• Pairwise comparisons use a table for each criterion to summarize how each of the solutions compares with others 
• Refer to table 3-1 pg 65

Prototyping and Testing:

• A prototype is a sample, scale model. 
• The purpose of a prototype is to find out if it will perform the way we want it to.
• Includes 3D printing, digital fabricatioin
• Testing may include the introduction of the design into a pilot installation or a test market which yields information on both performance  and marketability.

Working in Teams:

• Individuals cooperating to accomplish a common goal
• The most critical task for a team is to establish its purpose or way of doing things. 
• There are 7 topics regarding team behavior.
  -Ground Rules
  -Decision Making
  -Communication
  -Roles
  -Participation
  -Values
  -Outcomes
• Peer evaluations are a useful way for team members to communicate to one another and to their professor about how the members are performing. 
• CATME: Comprehensive Assessment of Team-member Effectiveness
• CATME measures five different types of contributions to a team using such a behaviorally anchored rating scale. 

Project Timeline:

• Step 1: Create a project timeline
  -All tasks needed to complete the project
  -Decisions that need to be made at various times
  -Any supplies or equipment that will need to be obtained
• Step 2: Create a responsibility matrix
  - List tasks and subtasks one by one
  -Create columns beneath each team members names
  -Put a check mark in the column beneath the name of the member who agrees to perform each task.
• Step 3: Consider team dynamics
  - Communication
  -Trust and Respect
  -Nothing is carved in stone

Chapter 5: Estimation

1. Sample Fermi Problems

·         Enrico Fermi taught at the University of Chicago after the war. Here, he was noted for giving his students problems in which so much information was missing that a solution seemed impossible. In general, they require the person considering them to determine an answer with far less information than would really be necessary to calculate an accurate value. Fermi problems are used to estimate reasonable answers. An example of a Fermi problem would be: Estimate the number of piano turners in New York City.

2. General Hints for Estimation

·         Determine the accuracy needed

·         Orders of magnitude is often used when comparing things of very different scales (small rock, and a planet)

·         Ballpark value is usually good enough

·         Always ask yourself if it is better to err on the high side or the low side.

·         Do not worry about minor effects.

3. Estimation by Analogy

·         Analogies are based on comparison measures.

·         Example: Estimate the size of a laptop using analogy: The size of my laptop is the same as a notebook.

4. Estimation by Aggregation

·         Aggregation is based on quantity measures by adding up an estimate of its parts.

·         Aggregation may involve adding together parts that are estimated by separate methods.

·         Example: Estimate by aggregation the amount of money students at your school spend on pizza each year. In order to solve, ask students around you how often they purchase a pizza and how much it costs. Convert the estimate into a cost per week. Multiply your estimate by the number of weeks in an academic year. Multiply that result by the number of students at your school.  

5. Estimation by Upper & Lower Bounds

·         An important part of estimating is keeping track of whether your estimate is high or low.

·         Engineers frequently make conservative estimates, which consider the worst case scenario.

·         Example: You are going out to dinner with a few friends and you will be paying for the whole meal. Estimate the average price for each person and bring that amount of money.

6. Estimation by Modeling

·         Used to calculate mathematical methods and statistics.

·         Example: A large sample of sunflower seeds is collected and their lengths are measured. Using that information, estimate the length of the longest sunflower seed you are likely to find if you measure one billion seeds. So, given a large sample, its average and standard deviation can be calculated. Assuming that the length of sunflower seeds is normally distributed, the one in a billion largest sunflower seed would be expected to be six standard deviations greater than the sample average.

7. Significant Figures

·         AKA Sig Figs

·         They are the digits considered reliable as a result of measurement or calculation.

·         It appears between two nonzero numbers.

·         It is a terminal zero in a number with a decimal point

·         Example: 376 has 3 sig figs and 0 decimal places

·         Example: 0.37600 has 5 decimal places and 5 sigfigs

8. Reasonableness

·         There are two types of reasonableness; physically reasonable and reasonable precision.

·         Physically reasonable says does the answer make sense in light of our understanding of the physical situation being explored or the estimates that we can make.

·         Reasonable precision is the number of digits in the answer commensurate with the level of accuracy and precision available to us in the parameters of the problem.

·         First ask yourself if the answer makes sense in the physical world.

·         If the final answer is in units for which you do not have an intuitive feel, convert to units for which you feel comfortable.

·         If your solution is a mathematical model, consider the behavior of the model at very large and very small values.

9. Precision vs. Accuracy

·         Precision is a combination of accuracy and repeatability, and is reflected in the number of sig figs used to report a value.

·         Accuracy is a measure of how close a calculation or measurement is to the actual value.

10. Engineering Notation vs. Scientific Notation

·         Scientific notation is typically expressed in the form #.### X 10^N, where the digit to the left of the decimal point is the most significant nonzero digit of the value being represented.

·         Engineering notation is expressed in the form ###.### X 10^M, where M is an interger multiple of 3 and the number of digits to the left of the decimal point is either 1, 2, or 3 as needed to yield a power of 10 that is indeed a multiple of 3.

·         The number of digits to the right of the decimal is usually 2-4.

·         Example: standard- 43,480,000. Scientific- 4.348 X 10^7. Engineering- 43.48 X 10^6

11. Calculator E-Notation

·         Use exponential notation when the magnitude greater than 10000 or less than .0001.

·         Never use a lowercase e for transcribing these values from the calculator such as 3.707e^-5. When you do use a capital E do not superscript the number following the E. Example; 3.707 E^-5.
      Means 'times 10 raised to the __' 

12. Fractions vs. Constants

·         Fractions are enemies to engineers.

·         Fractions are often difficult to glance at with instant comprehension of the actual value.

·         Seldom do engineers needs a precision of more than three or four digits; thus there is no need to try to represent values exactly by using the harder to read fractions.

A decimal is more useful to engineers.