Archive for August, 2009

Download the isee NetSim Template Model

August 21st, 2009 3 comments

A few months ago, we designed an interface template for our isee NetSim sample models.  The template is an iThink/STELLA model in which the interface layer is designed to look like a website:

  • Navigation buttons are styled to look like hyperlinks instead of push buttons.
  • Push buttons are used to perform actions, such as running the simulation.
  • Tabs along the top of each page let the viewer know which section they are in, as well as providing a way to quickly jump to any section.

An example of the interface template applied to a model published online

You can download the template model and use it as a starting point for creating interfaces to models you want to publish online.

Download the template for STELLA

Download the template for iThink

How to use the template

The template model consists of four interface pages: Home, Background, Explore Model and Simulate.  Navigation buttons to and from each page are already setup within the interface.  You can customize each section by replacing the placeholder text.  The pages are a starting point that establishes a website-like look and feel.

The easiest way to apply the template model’s interface to your own model is to simply copy and paste the pages.

  1. Open your own model and switch to the Interface layer.  Choose ‘Interface Prefs’ from the Interface menu and make sure the ‘Show Pages’ option is selected.  Set Page Size to 800×600.  This will allow you to see the page boundaries as you apply the template.
  2. Open the template model and from the Interface layer choose the Edit menu –> Select All, then Edit menu –> Copy to copy all of the pages to the clipboard.
  3. Go back to the interface layer of your model and choose Edit menu –> Paste.

When you have pasted the pages into your model, they will probably not be lined up correctly within the page boundaries.  The dashed lines show the boundaries of each page.  Using these dashed lines as a guide, use the arrow keys on your keyboard to make the pasted pages line up properly.

Now you can customize the title and text in each page.  Add a picture to the home page and build a control panel.  If you want, you can use the hyperlink button on the ‘Background’ page to link to online information, (PDFs, other models, Wikipedia, etc.).  Consider building a storytelling sequence on the ‘Explore Model’ page to unfurl the model a chunk at a time.  These are just a few customizations you can make.  Take a look at some of our sample models published online with isee NetSim for ideas.

If you publish some models online that use the template, we’d love to see them!  Leave a link in the comments so we can check them out!

Categories: Modeling Tips Tags: , ,

Rethinking ‘Cash for Clunkers’

August 11th, 2009 2 comments

C.A.R.SThere is no doubt that the Car Allowance Rebate System, or “Cash for Clunkers” program has proved to be popular with American car buyers.  So popular in fact, that it ran out of cash within the first six days of processing claims.  This news got me thinking about the program in a more systemic way.

Whether you think of the program as a stimulus for the economy or the environment, it cannot continue to operate without funds.  Congress had to quickly approve another $2 billion for the program when the initial $1 billion appropriation was exhausted in less than a week.  The rebate fund lacks an inflow of cash to offset the outflow of payments.

I wrote about a STELLA model of a self-financing program to promote cleaner vehicle sales in May.  The “Feebates” model uses fees charged on sales of vehicles that have high pollution rates to finance rebates for cleaner vehicles.  I asked the Feebates model author, Andrew Ford what he thought about “Cash for Clunkers”.  He sent me an article he co-authored with Todd BenDor titled “Simulating a combination of feebates and scrappage incentives to reduce automobile emissions”.  Basically, the article describes a feebates model with a “cash for clunkers” type of rebate added to promote scrapping older vehicles.  The article was published in the journal Energy, 31(2006), 1197-1214.

3808715790_393164d861Mr. BenDor was kind enough to send me the STELLA model so we could publish it to the web with isee Netsim.  We thought this would be a great way to start some discussion around the Clunkers program, public policy and using simulations to facilitate decision making.

Click here to run the simulation online.

  • Can you design a policy that stimulates the economy and reduces emissions?
  • This simulation uses fees to fund the program instead of deficit spending.  What other sources of revenue could we consider?
  • Many states levy a “sin tax” on tobacco and alcohol.  How would the public react to fees on high-pollution vehicles?

Post your answers in the comment section below.

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2009 Barry Richmond Scholarship Award

August 5th, 2009 No comments
Marcus Robinson and James Ranney accept 2009 Barry Richmond Scholarship Award

Marcus Robinson & James Ranney accept 2009 Barry Richmond Scholarship Award

The Barry Richmond Scholarship Award was established in 2007 by isee systems to honor and continue the legacy of our founder, Barry Richmond.  Barry was devoted to helping others become better “Systems Citizens”.  It was his mission to make Systems Thinking and System Dynamics accessible to people of all ages and in all fields.

The award is presented annually at the International System Dynamics Conference to an individual whose work demonstrates a desire to expand the field or to apply it to current social issues.

Barry had a particular passion for expanding the field into K-12 education.  He worked closely with teachers and young people at all levels to incorporate Systems Thinking tools and methodologies into the classroom.  With this in mind, it was a great pleasure to present this year’s award to Marcus Robinson and James Ranney, two students from Wilson High School in Portland, Oregon.

Marcus Robinson presents at SD Conference

Marcus Robinson presents at SD Conference

The scholarship committee was very impressed by the quality of the models and technical papers that these students submitted.   Both high school seniors were enrolled in Diana Fisher’s modeling class this past year.  For their final project assignment, they were asked to explore a topic of their own choosing.

Inspired by a video of the PBS NOVA program “Dimming the Sun”, Marcus chose to create a model that would help to answer the question “How Much do Carbon Emissions Need to be Reduced in Order to Stop Global Warming?” To download Marcus’ paper, click here.

After a run-in with a large frog at his summer camp, James was interested in answering “What is the Impact of Introducing an Invasive Species into an Ecosystem?” – in this case, the bullfrog into the Pacific Northwest. To download James’ paper, click here.

James Ranney presents during K-12 poster session

James Ranney presents during K-12 poster session

Both students presented their work at a parallel session during the conference and again at a special K-12 poster session.  What a delight it was to see how empowering modeling real-world issues is for young people and the enthusiasm they share for their work.

Thank you to the society for making a special effort to serve the K-12 community and provide opportunities for partnership.  Congratulations Marcus and James, Barry would be very proud!

Applications for the 2010 Barry Richmond Scholarship Award will be available on the isee systems and System Dynamics Society web sites. Check those sites for more information.