Introduction to engineering

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Introduction to engineering

• Dr. Yan Liu
• Department of Biomedical, Industrial and Human
  Factors Engineering
• Wright State University

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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

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ABETs 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 humankind

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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.

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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

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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

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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

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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.

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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

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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

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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

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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?
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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
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Bad Design (1)
Whats 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
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Bad Design (2)
Whats 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
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Bad Design (3)
Whats 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.
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Good Design (1)
Fun, educational, self-explanatory
LeapFrog's "Twist and shout multiplication"
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Good Design (2)
Simple, elegant, easy to use, easy to clean
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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

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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

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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 ltgt and
  ltgt, respectively, whereas lt_at_gt and ltgt are on the
  USA keyboard
• The placement of brackets, backslashes and such
  like vary
• Not optimal for typing

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French keyboard
US keyboard
UK keyboard
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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

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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

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Dvorak Keyboard Layout
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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

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• 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.
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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.
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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.
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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 affordance of 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

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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 to reverse the results of an
  error or to recover the state of the system

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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

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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)
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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

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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.)

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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.

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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.

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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 !

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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

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Brainstorming

• Types of Brainstorming
• Free-form (unstructured) brainstorming
• Participants simply contribute ideas as they come
  to mind
• Pros
• Participants can build on each others 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

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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

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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

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Design Touch Screen Zoo Information Kiosk
3. Task Analysis
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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
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Design Touch Screen Zoo Information Kiosk
5. Design (Cont.)
Animal Info Screen
Zoo Information Screen
6. Mockup Prototype
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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