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Introduction to engineering

Introduction to engineering. Dr. Yan Liu Department of Biomedical, Industrial and Human Factors Engineering Wright State University. Engineering Versus Science. Scientists Understand why our world behaves the way it does (“laws of nature”) Study the world as it is Thinkers Engineers

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Introduction to engineering

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  1. Introduction to engineering Dr. Yan Liu Department of Biomedical, Industrial and Human Factors Engineering Wright State University

  2. Engineering Versus Science • Scientists • Understand why our world behaves the way it does (“laws of nature”) • Study the world as it is • Thinkers • Engineers • Apply established scientific theories and principles to develop cost-effective solutions to practical problems • Cost effective • Consideration of design trade-offs (esp. resource usage) • Minimize negative impacts (e.g. environmental and social cost) • Practical problems • Problems that matter to people • Change the world • Doers

  3. ABET’s Definition of Engineering • ABET (The Accreditation Board for Engineering and Technology ) • Recognized in the United States as the sole agency responsible for accreditation of educational programs leading to degrees in engineering • “Engineering is the profession in which a knowledge of the mathematical and natural sciences, gained by study, experience, and practice, is applied with judgment to develop ways to utilize, economically, the materials and forces of nature for the benefit of [hu]mankind”

  4. Engineering Disciplines • Major Disciplines • Mechanical engineering • Electrical engineering • Civil engineering • Chemical engineering • Industrial engineering • Computer engineering • A subspecialty within electrical engineering at many institutions • Specialized, Non-Traditional Fields • Aerospace engineering • Materials engineering • Biomedical engineering • Nuclear engineering • etc.

  5. Electrical/Computer Engineering (ECE) • Largest of All Engineering Disciplines • About 353,000 or 26% (out of 1.4 million engineers) were electrical and computer engineers (U.S. Department of Labor Statistics in 2005) • Concerned with electrical devices and systems and with the use of electrical energy • Specialties • Electronics • Design of circuits and electric devices to produce, process, and detect electrical signals • Communications • A broad spectrum of applications from consumer entertainment to military radar

  6. Electrical/Computer Engineering (ECE) • Specialties (Cont.) • Power • Generation, transmission, and distribution of electric power • Conventional generation systems (e.g. hydroelectric, steam, and nuclear) • Alternative generation systems (e.g. solar, wind, fuel cells) • Controls • Design of systems that control automated operations and processes • Instrumentation • Use of electronic devices to measure parameters (e.g. pressure, temperature, flow rate, speed, etc) • Processing, storing, and transmitting the collected data

  7. Mechanical Engineering • Second Largest Engineering Discipline • About 221,000 or 16% (out of 1.4 million engineers) were mechanical engineers (U.S. Department of Labor Statistics in 2005) • Concerned with designing tools, engines, machines, and other mechanical equipment • Areas • Energy • Production and transfer of energy and conversion of energy from one form to another • Structures and motion in mechanical systems • Design of transportation vehicles, manufacturing machines, office machines, etc. • Manufacturing • Design and build requisite equipment and tools to convert raw materials into final products

  8. Industrial Engineering • “Industrial Engineering is concerned with the design, improvement, and installation of integrated systems of people, material, information, equipment, and energy. It draws upon specialized knowledge and skill in the mathematical, physical, and social sciences together with the principles and methods of engineering analysis and design to specify, predict, and evaluate the results to be obtained from such systems (IIE (Institution of Industrial Engineering), 1985) • Also known as systems engineering, production engineering, operations management • Fields • Operations research • Human factors • Quality control • etc.

  9. Industrial Engineering • Operations Research • Uses methods like mathematical modeling, statistics, and algorithms to arrive at optimal or good decisions in complex problems • Human Factors (or Ergonomics) • Application of scientific information concerning humans to the design of objects, systems and environment for human use (IEA (International Ergonomics Association), 2007) • Physical human factors • Deals with the human body's responses to physical and physiological stress • Cognitive human factors • Mental processes (e.g. perception, attention, cognition, motor control, and memory storage and retrieval) as they affect interactions among humans and other elements of a system • Organizational human factors (macroergonomics) • The optimization of socio-technical systems, including their organizational structures, policies, and processes

  10. Industrial Engineering • Quality Control • Ensure products or services are designed and produced to meet or exceed customer requirements • Similarity to Other Engineering Disciplines • Trained in the same basic ways as other engineers • Take foundation courses in mathematics, physics, chemistry, humanities, and social sciences • Difference from Other Engineering Disciplines • Emphasis on both people and technology • Focuses on how people interact with a system • Concern for the human element leads to system designs that enhance the quality of life for all people

  11. Design • Wikipedia Definition • Process of originating and developing a plan for a product, structure, system, or component • Achieve Goals with Constraints • Goals • The purposes of the design • What is for? Who is it for? Why do they want it? • Constraints • Material, cost, time, regulation, etc. • Trade-off • Which goals or constraints can be relaxed so that others can be met • Understand the Material

  12. A chair with a steel frame and a chair with a wooden frame are quite different. Often the steel frames are tabular or thin L or H section steel, whereas wooden chairs have thick solid legs. Why? What would happen if a wooden chair were made using the design for a metal one and vice versa?

  13. To design a system that involves humans, we have to understand humans, their physiological, psychological and social aspects and how they interact with the other components of the system

  14. Bad Design (1) What’s wrong with the design of this knife? Although you can tell which end is the handle and which end is the blade, it isn't clear which side of the blade cuts

  15. Bad Design (2) What’s wrong with the design of this stove? It is difficult to tell which control goes with which burner Good design Arrange the controls in the same configuration as the burners. It is quite easy to tell which burner goes with which control

  16. Bad Design (3) What’s wrong with the design of this Boombox? People generally expect the controls for a device to be on or close to the device. In this example, the CD buttons should be put next to the CD player and the tape buttons should be put next to the tape player.

  17. Good Design (1) Fun, educational, self-explanatory LeapFrog's "Twist and shout multiplication"

  18. Good Design (2) Simple, elegant, easy to use, easy to clean

  19. How to Make Good Design • Recognize that systems are built for users and thus must be designed for the users • Recognize individual differences • Recognize that the design of things and procedures can influence human behavior and well-being • Emphasize empirical data & evaluation • Rely on scientific method • Recognize that things, procedures, environments, and people do not exist in isolation

  20. What Is NOT Good Design • NOT just applying checklists and guidelines • These can help, but user-centered design (UCD) is a design philosophy and process • NOT using oneself as the model user • Know your real users; recognize variation in humans • NOT just common sense • e.g. “a picture is worth a thousand words” does not always hold

  21. QWERTY Keyboard • Layout • QWERTY are first six letters at the top row of alphabetical keys • The layout of the digits and letters is generally fixed except a few variations in some nations’ keyboards • e.g. French keyboards interchange both "Q" and "W" with "A" and "Z", and move "M" to the right of "L" • Non-alphanumeric keys vary • e.g. There is a difference between key assignments on British and American keyboards • Above 2 and 3 on the UK keyboard are the <“> and <£>, respectively, whereas <@> and <#> are on the USA keyboard • The placement of brackets, backslashes and such like vary • Not optimal for typing

  22. French keyboard US keyboard UK keyboard

  23. Dvorak Keyboard • An alternative standard keyboard layout to QWERTY, patented in 1936 by August Dvorak and William Dealey • Designed to address the problems of inefficiency and fatigue that characterized the QWERTY keyboard layout • Speed improvement of 10% ~ 15% • Reduction in user fatigue due to the increased ergonomic layout of the keyboard • Has failed to replace QWERTY standard • Currently, all major operating systems (e.g. Apple OS X, Microsoft Windows, GNU/Linux) can ship the Dvorak keyboard layout in addition to the QWERTY layout

  24. Dvorak Keyboard • Ergonomics Principles of the Design • It is easier to type letters alternating between hands • For maximum speed and efficiency, the most common letters should be the easiest to type. This means that they should be on the home row, the center row of alphabetical letters on a keyboard, which is where the fingers rest and under the strongest fingers • The least common letters should be on the bottom row, which is the hardest row to reach • The right hand should do more of the typing, because most people are right-handed • Stroking should generally move from the edges of the board to the middle. An observation of this principle is that, for many people, when tapping fingers on a table, it is easier going from little finger to index than vice versa

  25. Dvorak Keyboard Layout

  26. Chord Keyboard • Only a few keys are used • Allow users to enter characters or commands formed by pressing several keys together, like playing a chord on a piano (illustration) • Advantages • Extremely compact and thus can be built into a device (e.g. a pocket-sized computer) that is too small to contain a normal sized keyboard • A large number of combinations available from a small number of keys allows text or commands to be entered with one hand, leaving the other hand free to do something else • Disadvantages • Lack of familiarity • Cannot be used by a "hunt and peck" method, so their use is restricted to applications where additional training can be justified • Hunt and peck typing (or two-fingered typing) is a common form of typing, in which the typist must find and press each key individually

  27. 12 keys, so more than 4000 combinations are potentially possible • User can set up key combinations as macros for longer strings of text Twiddler2 Developed by Handykey Corp.

  28. Usability • Concerned with making systems easy to learn and use • A Usable System is • Easy to learn • Easy to remember how to use • Effective to use • Efficient to use • Safe to use • Enjoyable to use • Why is Usability Important • Many everyday systems and products seem to be designed with little regard to usability, which leads to frustration, wasted time and errors Examples of interactive products: mobile phone, computer, personal organizer, remote control, soft drink machine, coffee machine, ATM, ticket machine, library information system, the web, photocopier, watch, printer, stereo, calculator, videogame etc….

  29. The photocopier in our college has buttons like these on its control panels Imagine that you just put your document into the photocopier and set the photocopier to make 10 copies, sorted and stapled. Then you push the big button with the "C" to start making your copies. What do you think will happen? (a) The photocopier makes the copies correctly. (b) The photocopier settings are cleared and no copies are made If you selected (b) you are right! The "C" stands for clear, not copy. The copy button is actually the button on the left with the "line in a diamond" symbol. This symbol is widely used on photocopiers, but is of little help to someone who is unfamiliar with this.

  30. Usability • Important Design Principles of Usability (Norman, 1990) • Visibility • All necessary controls should be visible for the user whenever he/she is supposed to be able to use them • The design should provide visibility to all the set of possible actions • One control for each action that the user can take • Only the necessary parts should be made visible, depending upon the actions available to the user • Much visibility is harmful since it makes the system look complicated to use • Affordance • The affordanceof an object refers to the sort of operations and manipulations that can be done to the object • There should be a natural mapping between the parts that are made visible and the actions that they support • e.g. A button, by being slightly raised above an otherwise flat surface, suggests the idea of pushing it

  31. Usability • Important Design Principles of Usability (Norman, 1990) • Feedback • Sending back to the user information about what action has actually been done and what results have been accomplished • Feedback should be provided in a form that is easy to understand and interpret • Accommodation of errors • Minimize the chance of the error in the first place or its effects once it occurs • Make sure that the users have the right conceptual model of the system • Make it hard for users to commit a mistake • Forcing functions can be introduced to prevent errors from occurring by providing strong constraints on the system a) Interlock that maintains a task sequence b) Lockin that prevents premature termination of a task sequence c) Lockout that prevents starting a faulty operation • Allow the users toreverse the results of an error or to recover the state of the system

  32. User-Centered Design (UCD) • What is UCD • UCD a design philosophy and a process in which the needs, wants, and limitations of the end user of a product are given extensive attention at each stage of the design process • A multi-stage problem solving process which requires designers to not only analyze and foresee how users are likely to use a product but also test the validity of their assumptions with regards to user behavior in real world tests with actual users

  33. Identify need for human-centered design Specify context of use System satisfies specified requirements Specify requirements Evaluation design Produce design solutions User-Centered Design (UCD) The UCD Cycle in ISO13407 (Four activities interlock and form the basis for an iterative approach to the requirements-design-test cycle; the cycle is completed when the evaluation of a product shows that it meets the specified requirements)

  34. User-Centered Design (UCD) • Eight Steps in UCD • Step 1: Define the context • Step 2: Describe the user • Step 3: Task analysis • Step 4: Function allocation • Step 5: Basic design • Step 6: Mockups & prototypes • Step 7: Usability testing • Step 8: Iterative test & redesign

  35. User-Centered Design (UCD) • Define the Context • Identifying the type of applications or the usage of the system • e.g. Develop a kiosk for a zoo to provide practical information (e.g. how to get from location A to location B) as well as content to enrich the experience • Market • Whether this is a need for the system to justify its development • Describe the User • The important characteristics of the users of the system • Physical attributes (e.g. age, gender, size, reach, etc.) • Perceptual abilities (e.g. vision, hearing, touch, etc.) • Cognitive abilities (e.g. memory span, reading level, expertise level, etc.) • Personal traits (e.g. likes/dislikes, extrovert/introvert, patience, etc.) • Cultural and international diversity (e.g. languages, culture, ethics, etc.) • Special population (e.g. disabilities, elders, minors, etc.)

  36. User-Centered Design (UCD) • Task Analysis • Analyzing the way users perform the tasks when using the system • Talk to and observe users doing what they do • List each task • Break tasks down into steps • Function Allocation • Decide who or what is best suited to perform each task (or each step) • e.g. Machine remembers login Id and reminds the user, but the user remembers the password • Base this on knowledge of system hardware, software, users’ abilities, culture, communications protocols, privacy, cost, etc.

  37. User-Centered Design (UCD) • Basic Design • Summary of the components and their basic design (be creative!) • Brainstorming • Cross-check with design requirements, human factors references, hardware specifications, budgets, laws/regulations, etc. • Ensure that the design will support the requirements and comply with the constraints (verification and validation in software engineering) • Mockups & Prototypes • Rapidly mock up the system for testing with potential users • Pen and paper or whiteboard to start • Iterate, iterate, iterate!! • Increasingly functional and veridical • Implement a detailed prototype of the system • Prototyping is the process of quickly putting together a working model of the system in order to test various aspects of its design • Various prototyping tools are available • Visual Basic/Visual Basic.NET, Flash, Dreamweaver, Caretta, Synopsis, etc.

  38. User-Centered Design (UCD) • Usability Testing • Get real (or representative) users to perform tasks, using the prototype • Both objective and subjective (e.g. satisfaction) measures • Sometimes users “want” features that actually yield poor performance • Testing results are used to guide the iterative evaluation and redesign of the system • Iterative test & redesign • Repeat cycles of testing and reworking the system, subject to cost/time constraints • Focus on Functionality First !

  39. Brainstorming • An effective technique for generating a large number of ideas in a group setting • At least 2 people, but no more than 10 people • Facilitator • Guide the session, encourage participation, write down ideas, etc. • Facilities • A brainstorming space • Something to write down ideas (e.g. paper, white-board, etc.) • Four Rules • Rule out criticism • Welcome freewheeling • Seek large quantities of ideas • Encourage combination and improvement of ideas

  40. Brainstorming • Types of Brainstorming • Free-form (unstructured) brainstorming • Participants simply contribute ideas as they come to mind • Pros • Participants can build on each other’s ideas • Relaxed atmosphere • Cons: the less assertive or low-ranking participants may not contribute • Structured brainstorming • Solicit one idea from each person in sequence • Pros • Each person has an equal chance to participate, regardless of rank or personality • Cons • Lack of spontaneity • Rigid environment • Combination of free-form and structured brainstorming

  41. Provide general information about the zoo (e.g. zoo hours, exhibits, shows, etc.) • Provide information about each animal • Provide and print zoo map • Create and print a personalized itinerary • Weather reporting • Enhance visitor’s experience (having fun as well as being educated) • Can rapidly update information (general, animals, etc.) • Reduce cost (fewer employee are needed) Design Touch Screen Zoo Information Kiosk • 1. Define the Context • Identifying the type of applications or the usage of the system • Benefits to justify its development

  42. Design Touch Screen Zoo Information Kiosk • 2. Describe the User • The important characteristics of the users of the system • Physical attributes • Age: a wide range (16 – 70) • Size and reach: 5th percentile – 95th percentile of American population in the age of 16 to 70 • Perceptual attributes • Vision: normal • Touch: normal • Cognitive attributes • Reading level: Understanding of English at a high enough level to recognize and follow on-screen commands • Culture and international diversity • Language: English

  43. Design Touch Screen Zoo Information Kiosk 3. Task Analysis

  44. Design Touch Screen Zoo Information Kiosk 4. Function Allocation • User makes selections on the touch screen, and the machine processes the commands 5. Design Main Screen Idle Screen

  45. Design Touch Screen Zoo Information Kiosk 5. Design (Cont.) Animal Info Screen Zoo Information Screen 6. Mockup & Prototype

  46. Design Touch Screen Zoo Information Kiosk 7. Usability Evaluation • Thirteen people who have been to zoos participated in the usability evaluation experiment • Each participant performed a set of tasks (predetermined by the experimenters) on the prototyped design, and their task performance, including the number of clicks and number of errors, was recorded • After the tasks, each participant filled out a subjective questionnaire to rate his/her satisfaction with different features of the design • Evaluation data was analyzed 8. Iterative Test & Redesign • Based on the evaluation outcome, plans to improve the design were made

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