“I was captivated by the beauty of math”

Operations research – a systemic representation of systems in the real world in the form of mathematical models and their solutions – is a field of study that developed during WWII, in two places at once. In Britain, heads of the British Army worked on systematically improving data utilization by using mathematical tools in order to be more effective in combat. Across the pond, the teams working on the monumental Manhattan Project also encountered issues pertaining to operations research, including project management, prioritization, creating procedural work models, and allocation of resources – all while rushing to beat Germany on the race to develop an atomic bomb. To counter the excess of tasks, mathematician Richard Bellman who was working on the Manhattan Project developed the dynamic programming technique: solving a large, complex problem by breaking it down into sub-problems which in turn are broken down into additional sub-problems, and so on until one is left with problems that can be solved directly. Meet Dr. Nir Halman, a faculty member at the Faculty of Engineering’s Industrial Engineering and Information Systems track, and this is precisely his field of expertise.

Operations research, explains Dr. Halman, is divided into theory and practice: “Operations research theory revolves around developing new mathematical models and/or methods for fast, efficient solving of existing models. The practical aspect considers some problem in the real or engineering world, characterizes it using mathematical tools, and searches for the mathematical model that offers the fastest and best solution. In the Manhattan Project, for instance, the need was to develop an atomic bomb in record time, under various constraints.”

Dr. Halman is married and has 4 children. He began his career at Tel Aviv University where he acquired his BSc, MSc, and PhD in mathematics. He also obtained a second BSc in biology. “My two greatest passions in high school were math and biology. When I had to choose a track in high school, I took advanced math and physics, but I was always intrigued by biology. While I was getting my bachelor’s I also took some biology courses, just for fun, including advanced botanical studies and invertebrates. When I started my masters I realized I didn’t need much to complete a bachelor’s in biology, so I just did it while getting my masters in math. But it’s something I did for fun. As a profession, I chose math. I was captivated by the beauty of math where the deeper you go, the greater the beauty you discover.”

Clearly, Halman enjoys what he does. During his master’s studies, for example, he chose to study a problem that’s been plaguing the Israeli diamond industry. “I approached the engineer at the Israeli Diamond Institute and asked him if they had any problems I could help with,” he recounts. “He told me what courses to take and gave me some books and eventually I discovered a real-world problem, at the marking stage – the part where you have to plan what to do with the raw material, how to cut it and shape it, with the goal of achieving the one that would yield the most profit – that is, little to no flaws, optimal clarity, and color, as many carats as possible. It’s a classic optimization problem, and I found an approximate solution by using mathematical tools and computational geometry. Once I completed my thesis, I started doing R&D at an Israeli diamond company, Sarine, which would eventually become the first Israeli company listed in the Singapore stock exchange. I worked there for over a year, and came to the conclusion that I’m more fascinated by academic research.”

“I went back to get my PhD. I figured operations research practice is nice and all, but I wanted to take on a bigger challenge. So I moved on to operations research theory. In my doctoral thesis, I defined a new mathematical model that combines linear and integer programming. Some problems have to have an integer solution – a number of employees needed per shift at a café – and they’re considered complex problems for which there are no efficient algorithms. In my thesis, I characterized a subset of integer programming problems for which I provided a solution that runs in time linear in the number of the problem’s constraints. It was fascinating and I published some good papers, but it was a bit too removed from real-world application. It was hard to find real-world problems to fit the model – it’s too narrow and theoretic.”

“So for my post-doctoral research, which I did at MIT and at the Institute for Advanced Study, I transitioned to stochastic dynamic programming. It’s a useful, robust model that can be used to present plenty of real-world problems. Over the course of 4 years, I defined a subset of stochastic dynamic programming problems for which I could provide very efficient approximation algorithms, both in terms of run time and approximation ratio. It was really nice, very interesting and highly applicable in the real world in a variety of fields such as economics, engineering, business administration, and government and civil services.”

Halman returned to Israel in 2009 and joined the Jerusalem School of Business Administration at the Hebrew University (“an operations researcher can fit in anywhere from business administration, economics, engineering, to computer science and, of course, mathematics”). “When Bar Ilan opened the new industrial engineering and information systems track, it caught my eye for several reasons: not only was it the first program in Israel to combine industrial engineering and information systems, it was also the first industrial engineering program to launch in Israel in 20 years. I liked that it was new, meaning that I could have a great impact on the engineers of the future. I also liked the fact that this was going on at the Faculty of Engineering, a more exact science than business administration but just as applicative. What’s more, it’s a relatively young faculty, so there’s a lot of attention and support to young researchers. I was really happy to discover how wonderful the people are here – not just the faculty, but the students too. The atmosphere is pleasant, the team is very supportive, they help each other and share. It’s far from obvious.”

In January 2021 Halman joined the Faculty of Engineering. This year he’ll be teaching two courses: deterministic models in operations research during the first semester, a course for master’s students that starting next year will also be available to bachelor’s students; and stochastic optimization in operations management during the second semester, also for master’s students. He is currently forming his research group and looking for partners. “Because my field of mathematical optimization and its practical impact has the potential to make a very big impact, I managed to get some very competitive grants from the EU, the Israel Science Foundation, and the United States – Israel Binational Science Foundation,” he says. “I have research students from outside the university, and I’m calling all students with a passion for mathematics and algorithms seeking a very lucrative field in academia and beyond, to mail me their CVs at nir.halman@biu.ac.il. Generous grants await.”

Want to hear more about operations research? Come to the open department colloquium on operations research on November 24, 2021, at 4 PM in room 329. Dr. Halman will be there to talk about the field and how his research fits in with engineering. You are all invited...