3.8 Computer Models and Simulations

Exercise 2.2: Computer Specifications

The Top500 site lists details of the most powerful supercomputers in the world, and is updated on a regular basis. Other supercomputer brands students might want to investigate include Cray and IBM.

The types of computer links further down this page may also be useful for this task.

Types of computer

Supercomputing Super Powers (BBC) provides a graphical breakdown of the fastest supercomputers by speed, country, and operating system, while the TOP500 Supercomputing Sites is a regularly updated list of world's fastest supercomputers. The Green500 list is a similar concept, but instead of measuring raw performance, measures performance per Watt.

Cray - The Supercomputer Company have many examples of specifications and applications of supercomputers - the site is an essential read for this topic. Titan supercomputer is the world's most powerful (Telegraph) discusses the Titan supercomputer, while Building Titan: The 'world's fastest' supercomputer is a more in-depth analysis of it, including examples of how it will be used. In June 2013 this record was re-taken by China's Tianhe-2 supercomputer. What Is A Supercomputer? and The supercomputer behind the US nuclear arsenal give a good overview of supercomputers and the kinds of specifications we can expect them to have as of 2019.

For smaller devices, Pocket marvels: 40 years of handheld computers (ComputerWorld) has an interesting slideshow showing the developments in processing power, storage capacities, screen sizes, and input devices over the past 40 years.

Disease spread models

These interactive activities model the spread of various diseases. They are great resources for exercises 8.1 and 8.2 in the textbook, and for understanding more about how computer models work and their potential limitations.

• NetLogo Models Library: HIV / AIDS model
• Disease spread model
• Spread of Disease computer model
• Epidemic Modelling
• Measles epidemic simulator

Climate and weather models

Background

Models 'key to climate forecasts' (BBC) underlines the importance of climate models to modern science, while Supercomputing the Climate (video) that is a good introduction to the weather models and climate models. Hurricane Forecast Computer Models is another useful resource for understanding why models have inaccuracies.

How climate models work

Two articles by National Earth Science Teachers Association and How do climate models work? all explain how computer climate models work, with clear text and diagrams.

Development of climate models

In Pictures: Climate Models (BBC) shows graphically how climate models have developed over the past five decades, from relatively basic models of a spherical Earth to modern advanced models with many more variables and processes. New Supercomputer Enhances Reliability of Weather Predictions (PhysOrg) describes how new technological developments are driving better models.

Problems with climate models

Despite these advances in model development, the ARS Technica article Climate Models get Smarter, but uncertainly won't go away explains why model's results will always differ from reality.

Example models

The Greenhouse Effect model and Carbon cycle model from Gizmos are great examples to use in lessons. NetLogo Models Library: Climate Change is another useful example.

Ecosystem and Environmental models

The following models cover ecosystems and environments.

• Forest Ecosystem model
• Food Chain
• Rabbit population model

Gizmos models are all very modern, up to date, and beautifully presented. Making a (free) account removes the 5 minute time limit.

Other environmental models include:

• The Habitable Planet: Ecology Lab

Car crash models

Car crash models can be used to test the strength of different car designs, the effects of different safety measures, and the potential injuries to passengers and pedestrians. Car crash simulation is a comprehensive article that covers many aspects of car crash models and simulations. The following new articles and videos cover car crash models from standard road cars to racing cars:

• Car crash tests (video) shows how real (physical) car crash tests are conducted. It is good as an introduction to help students understand the level that computer models need to match.
• Simulating Safety is a good overview of how car crash models are created.
• Simulated Car Crashes Involving Pregnant Women (science Daily)
• Crashing Cars When They're Still a Gleam in the Designer's Eye (NYTimes)
• Car-crash Testing: Is It Accurate? (Desktop Engineering)
• Crashteams 'Crash reconstruction experts'
• FIAT Bravo Animation-front crash test (video)
• Toyota High-Tech Simulator Helps Racecar Safety
• Car crash simulator is a basic model of the forces at work during a car accident.
• Car crash software is a short video that discusses how computer models are validated.

Economic models

Economics models really jumped into the media spotlight after the global economic recession of 2008-2009. Models were (and are) widely used in the finance industrial - even to the extent that transactions can be made automatically without human intervention. The articles below discuss the social and ethical issues related to these models:

• Why Economic Models Are Always Wrong (Scientific American)
• After the Crash: How Software Models Doomed the Markets (Scientific American)
• Recipe for Disaster: The Formula That Killed Wall Street (Wired)

Various models

• Predicting earthquakes: Titan takes on the big one discusses the latest developments in earthquake prediction technology and the problems that still exist. A good example of why even supercomputing power cannot solve some problems.
• Alaskan Way Viaduct - Earthquake Visualisation (video) is a frighteningly realistic visualisation of the effect of a large earthquake in a downtown area.
• F1 Car - Engine and Radiator Flow (video) demonstrates Computational Fluid Dynamics (CFD) which are used by designers of many cars, aircraft, and space craft.
• Computer models predicts path of lost hikers (PhysOrg)
• Destroying drug cartels, the mathematical way (New Scientist) talks about a rather  unusual type of computer model.
• Microsimulation of Road Traffic Flow
• The Habitable Planet: Demographics Lab
• Orbital Motion - Kepler's Laws

Driving simulators

Along with flight simulators, driving simulators are the canonical example of simulator software. They range from quite basic software driving simulators (video) that run on most modern computers, to full-blown simulators with dedicated full motion hardware. Racing teams also make extensive use of simulators, as demonstrated by the Red Bull F1 Simulator with Mark Webber, On Board with Lewis Hamilton in the F1 Simulator, and Trying out Fernando Alonso's Ferrari F1 simulator (video).

Flight simulators

Military and civilian pilots alike make extensive use of flight simulators to hone their skills in safety. The following resources provide an insight into just what a fully-equipped simulator is like.

• Boeing flight simulator (video)
• RAF Valley Hawk simulator (video)
• Pilots train without taking off (BBC)
• Flight simulator pictures
• Video: Airbus simulator during a bird strike and engine fire.

Help for practical spreadsheet projects

Basic computer models can be constructed relatively easily in class using a  spreadsheet. GCFLearnFree and its YouTube channel have excellent video lessons for Excel and a range of other office-style software. Motion Training's video tutorials for Excel are also very good. Dummies.com has text based tutorials on several specific aspects of Excel that often cause problems.

Lesson resources: Keyword Bingo

Keyword bingo makes a great lesson starter or revision activity. Give students one or two cards containing ITGS database key words, then read out the definitions. Students need to match one of their keywords (not all cards contain all key words). The first student to get all key words wins. This set of cards covers only key terms related to the Hardware and Software chapters of the book. Download: Student cards, teacher clues.

Lesson resources: Revision Flashcards

Models and simulations revision flashcards to test students on the key terms. The 'Learn' and 'Test' modes of Quizlet work best.

Patient simulators and training tools

Patient simulators are computerised mannequins used to train medical staff. Unlike traditional first aid mannequins, patient simulators use computer technology to provide outputs (such as 'heart beats') and realistic responses to treatment. Patient simulators are available in several versions, including male, female, child, and baby.

The CAE Healthcare home page has extensive information about patient simulators, including high quality images, video examples and use cases for nurses, EMS, and the military. Robot patients help doctors polish their skills (BBC video) also shows these patient simulators in use.

Virtual patients: hi-tech training for the operating theatre explains how Anatomage, a new touch-screen virtual operating table, works. The system features a complete digital 'patient', and is being used to train staff at Saint Mary's hospital in London.

Computer models for health care

Various computer models are used to help design new drugs and administer existing drugs and treatments more effectively:

• Predicting adverse drug reactions with higher confidence
• Design Help for Drug Cocktails for HIV Patients: Mathematical Model Helps Design Efficient Multi-Drug Therapies (Science Daily)
• Computer Model Could Help Tailor Chemotherapy Treatments (Science Daily)
• Computer Model for Testing Heart-Disease Drugs (ScienceDaily)
• Computer Model Against Unnecessary Use Of Antibiotics (ScienceDaily)

Other health models are used to improve our understanding of the human body:

• A Computational Model of the Human Heart
• Heartworks 3D Virtual Heart (MedGadget)
• Researchers use computer model to probe mysteries of human immune system (Virginia Tech)

Finally, computer models may be used to predict the spread of a certain virus or bacteria, with a view to preventing it:

• AIDS spread model (interactive model)
• Computers to help superbug fight (BBC)
• Computer model reveals deadly route of Ebola outbreak
• How modelers took on the Ebola outbreak (IEEE Spectrum)
• Measles epidemic simulator (interactive model)
• Computer models to predict the spread of Zika

Distributed Computing

Distributed Computing, sometimes called Grid Computing, uses the combined processing power of many individual, geographically separate computers to solve large computing problems. Here are three examples of community distributed computing projects.

Folding@Home is a great example of using distributed computing techniques. In order to design better treatments for many common cancers and diseases such as Alzheimer's and Parkinson's, Stanford scientists are studying how proteins 'fold' and 'misfold'. Unfortunately these biological simulations take a lot of computing power - more than is available to the scientists. To solve this problem they started the Folding@Home project - by downloading a small program you can have your computer perform calculations on one of these folding projects using 'spare' processor time. So far over 150,000 computers are involved in the project, bringing much more computational power than would be available in one location. Rosetta@Home is a similar project that aims to determine the 3D shapes of proteins.

Another example of a distributed computing project is SETI@Home. The Search for Extraterrestrial Intelligence collects huge amounts of data from radio telescopes scanning the skies, and uses distributed computing power to look for patterns in that data which may indicate signals generated by an intelligent species.

Finally, ClimatePrediction.net bills itself as the 'world's largest climate modelling experiment'. Users running the climateprediction.net software help compute climate predictions for the next century, including temperature and rainfall data.

Heat transfer model

Energy 2D is an interactive heat transfer model. Students can create structures made from different materials and test their thermal characteristics. There are versions for Windows, Mac OS, and Linux, so it should be accessible to all students.

You can read more about how I use it in ITGS.

Fire spread models

Computer models can be used to predict the chances of wildfires breaking out, and the path they may take if they do. Wilder wildfires? Computing helps predict their path and fury gives a good overview of these models. Burning Question (The Atlantic) discusses why computer models of wild fires are becoming less accurate.

There are also several interactive computer models that students can use. Fire! is the most basic model, really little more than a visualisation of probabilities. However, it is useful for discussions on the accuracy of models. A Better Fire is a more advanced version that includes wind direction and strength, as well as forest density.