# Blog Archives

## How to send bulk email to your students using R

December 1, 2016
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In this post I write about a technique I use to send personalized bulk emails to my students at the open and distance education university where I teach (the Universidad Nacional Abierta in Venezuela, or UNA, for short). Being able to mass-email students with personalized messages is should be an important issue in any distance education setup. However, as...

## R Puzzle No. 2 – Where’s the zebra?

October 5, 2016
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For the second R puzzle, we will tackle the famous Zebra Puzzle, sometimes known as Einstein's Puzzle or Einstein's Riddle. There are various implementations of solutions to the puzzle in different programming languages1, but here we will be using R and an R package called lpSolve, which is intended to solve linear programming problems. I had a lot...

## Population Growth Models using R/simecol, Part 1 : The world population

September 22, 2016
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In this entry, as part of the series on dynamic systems modeling with R and simecol, we'll take a look at population growth models, our main focus being on human population growth models and how they tie into other theoretical frameworks such as demographic transition theory and carrying capacity. These different models are then fitted to data on world...

## R Puzzle No. 1 – Five Sailors, a Monkey and some Coconuts

September 6, 2016
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In a brief diversion from the simecol dynamic system models, which I promise to resume in the future, I'll start another series of entertaining posts about solving mathematical/logic puzzles using R, of which this post you're reading is the first. This time around, we'll take a crack at the Problem of the Five Sailors, One Monkey and a...

## Simulation models of epidemics using R and simecol

August 31, 2016
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In this post we'll dip our toes into the waters of epidemological dynamics models, using R and simecol, as we have done in the previous two posts of this series. These models of epidemics are interesting in that they introduce us to a more general class of models called compartment models, commonly used in the study of biological systems....

## How to simulate a bouncing ball in R – more on simecol events and external inputs

August 14, 2016
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In this post I'll clarify the incorporation of external inputs in the dynamic model specification using simecol, again reviewing the relevant parts of the simecol simulation model for the Battle of Iwo Jima that I presented in the last post. I will also give an alternate specification for this model and compare both ways of specifying external inputs...

## R/simecol Simulation Model for the Battle of Iwo Jima

August 8, 2016
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It was about 71 years ago today that the Second World War on the Asian front ended. After the tragic Little Boy and Fat Man detonations over Hiroshima and Nagasaki on the 6th and 9th of August 1945, respectively, the Japanese surrendered in August 14th.When I taught the Simulation and Modeling course for the Systems Engineering department...