IDeA Labs Members Participate in the 27th Annual Student Research Conference
March 9, 2013
IDeA Labs Members Vasu Chetty, Philip Pare, Nicholai Christensen, Daniel Fullmer, Gustavo Rodriguez, and Nathan Woodbury presented their research at the 27th Annual Student Research Conference hosted by the Brigham Young University College of Physical and Mathematical Sciences on March 9, 2013. Copies of their presentations are included below.
Vasu Chetty
Dynamical Structure Function Identifiability Conditions Enabling Signal Structure Reconstruction
Abstract – Networks of controlled dynamical systems exhibit a variety of interconnection patterns that could be interpreted as the structure of the system. One such interpretation of system structure is a system’s signal structure, characterized as causal dependencies among manifest variables and represented by its dynamical structure function. Although this notion of structure is among the weakest available, previous work has shown that if no a priori structural information is known about the system, not even the Boolean structure of the dynamical structure function is identifiable. This work demonstrates precisely the a priori structural information that is both necessary and sufficient to reconstruct the network from input-output data.
Philip Pare
The Information Cost of State Realization
Abstract – Realization theory explains the relationship between input-output, or “black box”, descriptions of systems and corresponding state machines. The state-space model of a system describes details about how the system computes its response to various stimuli that the black-box description does not reveal. As a result, there are generally infinitely many state realizations of a given black-box model. This work explores the information cost of discovering a system’s true state realization given a block box description of its input-output behavior.
Nicholai Christensen
Exploring the Inherent Memory Interval of Tetris-like Systems
Abstract – Tetris is a game where blocks of different shapes pile on top of each other. Given a particular portfolio of block shapes, however, it is not clear how many blocks need to stack before the top contour no longer depends on the shape of the blocks that precede the stack. This research explores the length of this inherent memory interval for a particular class of Tetris-like systems.
Daniel Fullmer
Press Sheet Optimization for Open Loop Control of Industrial Scale Gang-Run Printing
Abstract – We consider a problem in the printing industry for gang-run printing of paper products over multiple days. The competitive and high-volume nature of the industry mean that small gains in efficiency translate to significant cost savings and ultimately lower prices. For each day, the problem is to choose which orders to print and the press sheets to print them on that would minimize the total cost of production. We formulate this problem as an integer linear program and find feasible solutions using traditional solvers. This method was compared with optimization by hand in a real factory and significant cost savings were found.
Gustavo Rodriguez
Characterizing the Structure of Oscillating Systems
Download (PDF) Abstract – A key part of studying dynamical systems is understanding the notion of structure for the system. Dynamical structure functions represent the structure and dynamics of a linear time-invariant system at a resolution consistent with the number of measured states in the system. Dynamical structure functions have typically been applied to nonlinear systems by first linearizing the system about an equilibrium point and then studying the structure close to the equilibrium. This work seeks to extend previous results by determining the notion of structure for a nonlinear system around a limit cycle rather than a single point using a technique known as decoupled sampling developed by us. We will use the system described by an electronic oscillator as an example to study the structure of the system.
Nathan Woodbury
Vulnerability Analysis of Feedback Systems
Received the “Best Session Presentation” award
Abstract – We explore the vulnerability of a system during a destabilization attack in which an attacker acts on a single link within the system’s logical interconnection structure. Previous work has shown that vulnerability on a link results from the link being involved in a feedback loop. In extension to this previous work, we explore the case where feedback in the system is necessary. Intuitively, vulnerability should be reduced by reducing the number of links that are in feedback. However, we provide a counter-example which shows that this intuition is wrong and that it is possible to “fight fire with fire” by adding links in feedback to reduce the vulnerability of the system. In addition, we explore how a controller might be designed in order to reduce the vulnerability of a system in which it is connected in feedback.