Mikial Nijjar-PROBLEM SOLVING & SYSTEMS

1. PROBLEM SOLVING & SYSTEMS Mikial Nijjar

2. Problem Solving – Humans have always needed food, clothing, shelter and healthcare. – Early humans lived in caves and ate fruits and seeds of plants ▪ Problems of Society – Disposal of wastes – Production of enough energy – Continuous supply of clean and safe water ▪ Problems of Individuals – Skills in programming – Impaired vision – Sound quality of recording systems – Communication between drivers

3. Good Design in Problem Solving – Low-cost and easy to use – Benefits outweigh the problems ▪ Examples – Telephones, internet, suspension bridges etc ▪ Superconductors – Energy is lost in resistance as electricity flows – Superconductors could only be made at around –432oF – Liquid helium was used but was too costly – Some materials work in liquid nitrogen that could go up to - 234oF – Materials are brittle and hard to make into wire with such temperatures

4. Method of Problem Solving – Seven steps in problem solving ▪ Describe the Problem – A statement describing the problem gives a way of thinking about the problem, like ‘people working for long hours get a back pain’. – This description decides whether the problem is interesting, important ---- example on page 50 ▪ Describe the Results – Goals of solving the problem should be defined – Design criteria --- list of specifications that includes all the requirements of the problem – The specifications should also include the limitations of the problem

5. Method of Problem Solving ▪ Gather Information – Gathering information to solve a problem is called research – Basic research --- nature of different materials and processes – Market research --- determine if customers will like the new product ▪ Think of Alternative Solutions – Past experience of others – Brainstorming in a group for some creative ideas – Develop alternatives by trial and error – Insight --- an idea may just pop up into your head – Some of the most important discoveries, like penicillin, have been discovered by accident

6. Method of Problem Solving ▪ Choose the Best Solution – Each alternative must be examined for design criterion and constraints – Optimization --- changing or combining alternatives to improve them – Tradeoff --- selecting the best overall solution, , e.g. cost and strength of a metal ▪ Implement the Solutions – Prototype or model of the solution is made to check for cost, risks, e.g. model of an airplane in a wind tunnel ▪ Evaluate the Solution – Observation may suggest some improvement in design or construction of the solution --- feedback – Once satisfied, we can build the full-scale structure, or start mass- producing the product

7. Modeling Design Solutions – Charts and Graphs --- describe how an alternative solution might work – Mathematical Models --- use of mathematical equation to predict performance – Sketches, Illustrations, and Technical Drawings --- show ideas in picture form – Working Models --- can be partly or fully functional. Its material and size may and may not be the same as that to be used – Computer Simulation --- displays a picture of the idea on screen. It is most useful when a large number of calculations must be carried out

8. Real World Problems – Technological decisions must take both human needs and the protection of the environment into consideration ▪ Social/Environmental Concerns – An airport or a nuclear plant cannot be built near a residential area – Needs of the society or the community must be considered ▪ Politics – Groups of people have different interests, e.g. in case of a nuclear power plant – Risks of a new development should be traded for its benefits ▪ Risk/Benefit Trade-Offs – Use of satellites, cars etc

9. Real World Problems ▪ Continued Monitoring – All the effects of a technological solution may not be known until long after the solution is implemented – Some drugs may have harmful side effects ▪ Values – Products’ advertisements have certain limitations – Some people prefer a sports car or a luxury car while others go for a basic car

10. Systems – A system is a means of getting a desired result, e.g. space shuttle, calculator, car etc ▪ System Model – The input is the command we give a system or it’s the desired result – The process is the action part of a system --- it combines the resources – The output is what is produced or it’s the actual result – Feedback is information about the output that can be used to change it --- monitor --- system diagrams on page 65 and 67 – Systems with feedback are called control systems or feedback control systems or closed loop systems – Systems without feedback are called open loop systems

11. Thank You

12. Systems – Even our own bodies contain systems – The body has many control systems like sugar level, heartbeat, oxygen collection etc. ▪ Multiple Outputs – A system may produce several outputs – The outputs from a coal-burning power plant may by • Expected & Desirable ~ power • Expected & Undesirable ~ noise and smoke • Unexpected & Desirable ~ tropical fish is flourished in the warm water • Unexpected & Undesirable ~ acid rain due to the pollution ▪ Subsystems – Many smaller systems in a large system are its subsystems