Numeric Models

Find an academic article that uses a numeric model and is interesting to you. (Hint: use the search term “System Dynamics”.) The model should fit the criteria of a scientific model.

Upload a pdf of the article or provide a citation (Title, Author, Journal, etc.). Then critique the article, answering the following questions:

1. How would you describe the model? What were the box variables (or levels or stocks)? What were the rate variables? Other parameters?
2. What research question(s) did the authors investigate? 
3. What did the researchers learn by using this model? What were their results?
4. How did the researchers make sure their model is credible? Do you think it is trustworthy enough to investigate their research question(s)? 
5. Explain how the model fits the criteria of a scientific model. Please address all four criteria outlined in the Scientific Model Criteria document.
6. Include a link or full citation for your source material.

Reply posts: Next, write substantive, thoughtful replies to at least two of your peers’ posts. Reply posts should address the following prompts:

• Do you agree with the assessment in the original post? If you do agree, indicate what convinced you. If you don’t agree, explain why. 
• What other research questions might be addressed by the model? 
• What other types of models might address the research aims?
• You may also share any prior knowledge or personal experience you have with the topic to enrich the discussion. 

Post 1 to reply:

1. How would you describe the model? What were the box variables (or levels or stocks)? What were the rate variables? Other parameters?

The model looks at waste management in Latvia (although could be applied anywhere) and uses mathematics to find the best way to decrease waste and increase waste recycling. The model variables include waste, incentives to recycle, taxes for packaging materials, waste recycle rates, landfill fractions, recovery rates, and more.

1. What research question(s) did the authors investigate? 

What are the most effective ways to reduce waste and increase recycling and re-using of waste products and materials. Is there a way to reduce waste and what are the most effective combinations of variables to make this happen?

1. What did the researchers learn by using this model? What were their results?

Packaging tax will be a very important part and effective way to reduce materials used in packaging.

1. How did the researchers make sure their model is credible? Do you think it is trustworthy enough to investigate their research question(s)? 

Researchers accounted for a lot of real life variables that add to the verification of the design of the model. The validation is not necessarily included in the article, however the real life data would be produced afterward to validate the model since the model was used to produce new policies on waste management in Latvia.

1. Explain how the model fits the criteria of a scientific model. Please address all four criteria outlined in the Scientific Model Criteria document.

It simplifies the real world functions of waste management systems significantly and accounts for as many variables as realistically possible. It generates information about how the system operates and which factors of waste management are most influential on recycling, etc. It is used in a real experiment where policy is developed for Latvia and ultimately the study can be validated with the real world data gathered from Latvia’s new policies.

1. Include a link or full citation for your source material.

https://www.sciencedirect.com/science/article/abs/pii/S0921344914000901

Post 2 to reply:

I chose a model where they compared models for computing underwater radiances and irradiances (light fields). They used seven models and used numerical solution of the radiative transfer to compare. They applied these models to several problems drawn from optical oceanography. In the end, the found that based on their graphs and the information they gathered, each of the numerical models they discussed and went through seemed to show correct mathematical views of radiative processes and the effects of the air-water boundary. They also went on to state that these models provided accurate numerical solutions of associated equations. They were able to use seven models to test. The use of using multiple models and being able to replicate and get similar results makes their model more credible. However, I think it would’ve been more credible if they could’ve used more. This did fit a scientific model. The models used were a simplification of the target system (light fields in the ocean), it was used to find information on radiances and irradiances, it produced new synthetic data, and was used in an numerical model experiment environment.

https://www-osapublishing-org.proxy.lib.pdx.edu/view_article.cfm?gotourl=https%3A%2F%2Fwww%2Eosapublishing%2Eorg%2FDirectPDFAccess%2FE2A79D5D%2DE43C%2D8D8E%2D5A52AD5C4E69B67D%5F72379%2Fao%2D32%2D36%2D7484%2Epdf%3Fda%3D1%26id%3D72379%26seq%3D0%26mobile%3Dno&org=Portland%20State%20University%2C%20Branford%20Price%20Millar%20Library