Juan Pablo Vielma, Ph.D. student in the Stewart School of Industrial and Systems Engineering, stands poised to earn his doctorate degree this summer. Over the past few years at Georgia Tech, Vielma has studied operations research at the graduate level, has taught undergraduate optimization courses, and has conducted research with faculty advisors Dr. Shabbir Ahmed and Dr. George Nemhauser. Recently, Vielma was awarded the 2009 Herman Goldstine Postdoctoral Fellowship in Mathematical Sciences for his research, lauded by Dr. Ahmed as "significant contributions to problems that lie in the intersection of two difficult areas **" discrete and nonlinear optimization." Vielma holds a Bachelor in Mathematical Engineering from the University of Chile.

On May 1, 2009, Joshua Wilkinson, ISyE undergraduate, interviewed Vielma on his life at Georgia Tech.

What motivated you to come to Georgia Tech from Chile?
I knew of the school's rankings, and I also knew some friends who were studying here. They told me what it was like here, and I liked it. I already had an idea of what the classes were going to be, what kind of research is done here, and who the professors are.

How have your Ph.D. studies differed from your undergraduate experience?
The main difference is that courses are not the central part of the program; I haven't actually taken a course in a couple years. After the first year, it's mostly about what research you do. You have a lot of freedom, but you have to figure out what it is that you want to do. There is more of a creative aspect at the graduate level.

On what topic is your research most focused?
It's mostly focused in the theoretical aspects of integer programming. In integer programming, you have requirements on the variables to be integers. For example, you might have to route cars, and they are not something you can divide infinitely, like water. That's actually what makes the problems difficult.

Is your research motivated more by a love of mathematics or a desire to apply your understanding to real-world problems?
I would say the interaction between them. I like the math, but I find that most interesting math problems come from applications, and it's also fun to use math to solve real-world problems. I've looked at applications involving transportation logistics, natural resource management, and chemical process engineering.

Finish the sentence: Few people know that...
...integer programming is not solvable by simply throwing it into a computer program. It requires a certain human understanding of the problem, the inputs, and the model. Knowing about the problem and changing it a little bit might make it much easier to solve, and giving the model to the computer in the correct way is important, too.

How does receiving the Goldstine Fellowship affect your future plans?
It postpones my appointment as an Assistant Professor with the University of Pittsburgh for one year so that I can attend the Fellowship. I will be located in the IBM Watson Research Center in Yorktown Heights, New York, and I will have the opportunity to work with very smart people and to apply what I know to different research areas.

When do you hope to complete your Ph.D. at the Stewart School of ISyE?
I have to graduate by July of this year, so I'm defending my dissertation entitled "Mixed Integer Programming Techniques for Solving Non-Linear and Stochastic Problems" on July 2nd.

Is teaching a long-term career goal of yours?
I consider research dear to my heart, but I also like university life. Teaching actually helps you to understand problems much better. Oftentimes, students will raise questions that you haven't thought about, and that will definitely deepen your understanding. It's also nice to pass the knowledge to people who will continue to perform research.

What hobbies are you passionate about in your free time?
I enjoy scuba diving in Florida, but I haven't had a chance to do it much lately. I like rock climbing, and I also used to like photography. But in the last couple of years, I find that my interests have shifted. I find research fun, so I dedicate more time to it. I consider maybe half of my research to be work, and the other half to be hobby.

What advice do you have for students of ISyE?
When you're approaching a problem, don't try to do it mechanically. If you do it mechanically, then you only learn to solve that problem. Try to develop the ability to understand and to solve problems rather than memorizing formulas for solving very specific sets of problems. Then, you should be able to solve problems that weren't expected, and those are the interesting problems that you're likely to face in the real world. They're not going to be the problems from the book; they're going to be problems you've never seen before, and you're going to have to look in your toolbox and to adapt your knowledge.