Complex Issues + Computer Simulation = Better Performance

In many cases, details most people never think about can be vital to efficient operation. Take the size of components in electronic circuits, for instance. If these components, such as transistors or capacitors, aren’t precisely the right size, laptops or other devices can overheat, run too slowly or break down.

In a research paper, Eunji Lim, PhD, and two co-authors outlined a new method to quickly and reliably determine the optimal sizes of analog circuits found in many electronic devices. Her method uses a mathematical algorithm in combination with a commercially available circuit-simulation computer program.

This new computer simulation method results in an exact fit for optimal performance.

“There are many electronic components inside a single circuit, such as transistors and capacitors, and their physical dimension is so small, they’re not even visible. The performance of the circuit depends on the physical sizes of the electronic components inside it. We wanted to determine the optimal sizes of these components to maximize the output performance of the circuit,” said Dr. Lim, an assistant professor of decision sciences and marketing.

Optimization and Simulation

“We focused on finding an optimization method that can fully take advantage of the unique structure of analog circuits. Most previous studies used trial and error or ad hoc approaches without rigorous theoretical foundations. We wanted to find a better solution,” she explained.

For major semiconductor manufacturers, such as Samsung or Intel, determining the optimal circuit size prior to mass production is crucial and would result in devices with improved performance. For consumers, it would mean higher-quality, more reliable products.

The research paper, “A Theoretically Sound Approach to Sizing Analog Circuits,” by Dr. Lim and her co-authors, is available online from the Journal of Semiconductor Technology and Science.

Another paper by Dr. Lim, recently submitted for publication, used computer simulation to address a problem in supply chain management involving moving goods from one location to another with precise timing. A major automobile manufacturer was having difficulties ensuring that enough shipping containers were in the right place at the right time to transport parts. Container shortages could shut a plant down until more containers arrived, potentially causing delays at every subsequent step, including for dealers and consumers.

“It was a complex supply chain system. The company received parts from many suppliers for assembly at manufacturing plants and used shipping containers to transport these parts from plant to plant as needed. Sometimes they were short of containers when they needed to ship,” said Dr. Lim.

“We designed a simulation including all the plants and suppliers to predict shortages of containers, so shortages could be prevented before they happened,” she said.

Dr. Lim is an authority on supply chain management and operations management, particularly on applying computer simulations and data analytics to supply chain systems. She holds a PhD in management science and engineering from Stanford University.

She has been at Adelphi since 2018. “Adelphi offers a great balance between teaching and research,” she said. “By conducting research, faculty members stay relevant in their fields and that benefits our students, who want to learn from engaged experts.”