1st Iowa Computer Science Graduate Research Symposium (2015)

Welcome to the 1st Iowa Computer Science Graduate Research Symposium (2015). Senior CS PhD students presented talks on their latest research, showcasing a variety of CS research areas including algorithms, mobile computing, networks, programming languages, and virtual reality. Talks were intended for a wide audience with interest in CS, including CS juniors and seniors.

The Computer Science (CS) department also hosted a Prospective Student Visit Day for individuals from around the country at the Graduate Research Symposium. We are looking for strong students to join our MCS and PhD programs. A wide variety of research areas are represented by our world-class faculty including algorithms, computational epidemiology, distributed computing, human-computer interaction, machine learning, massive data algorithms and technology, mobile computing, networks, programming languages, text mining, and virtual reality. The talks presented by current CS graduate students at the Symposium are excellent examples of the exciting research taking place here in Iowa City!


Friday, Nov 6, 2015

Morning Sessions (in MacLean Hall) For Visiting/Prospective Students


Visiting students will meet with Computer Science faculty members


Visiting students will meet and have lunch with Computer Science Graduate Students

Graduate Student Research Symposium (in W401 Pappajohn Business Building)


Session One


Ryan McCleeary

Exact Real Arithmetic with Floating Point Computations


Vivek Sardeshmukh

Distributed Graph Algorithms on the Congested Clique


Yuanyuan Jiang

Using Virtual Environments to Study Pedestrian Road Crossing




Session Two


Farley Lai

High Performance Stream Processing for Mobile Sensing Applications


Sikder Huq

Self-Adjusting Real-World Networked Caches


Santanu Bhowmick

On the Approximability of Orthogonal Order Preserving Layout Adjustment

3:45-4:00pm Break

Keynote Speaker Zubair Shafiq

Tracking, Surveillance, and Fraud in the Online Advertising Ecosystem




Ryan McCleary - UI CS PhD CandidateRyan McCleeary

Talk: Exact Real Arithmetic with Floating Point Computations

In this talk, we will be covering arbitrarily precise computer arithmetic. We will do this by examining two particular systems; an arbitrarily precise floating point system, and an exact real arithmetic system using a co-inductive approach to real numbers. We then propose some preliminary results of a lazy exact real arithmetic system using floating point computations that uses ideas from both of the surveyed systems.

Bio: Ryan McCleeary received his Bachelor's degree in Mathematics and Computer Science from Coe College in Cedar Rapids. He is currently in his 4th year PhD candidate of Computer Science at the University of Iowa. His research interests include, computational logic, programming language theory, lazy computation, and exact real arithmetic.

Sikder Huq - UI CS PhD CandidateSikder Huq

Talk: Self-Adjusting Real-World Networked Caches

Large content providers like Facebook, Google, and Netflix extensively rely on a globally distributed network of cache servers. Consistent hashing is typically used to distribute objects across servers. Real-world content access patterns are skewed and subject to dynamic changes, as some objects become extremely popular at times. Since consistent hashing does not take the dynamics of access patterns into account, it exhibits poor load balancing for skewed access patterns. Using logs from a large-scale commercial content delivery network, we demonstrate the limitations of consistent hashing. We further evaluate a series of improvements for consistent hashing and highlight their limitations. Finally, we present an online distributed self-adjusting protocol to address these limitations.

Bio: Sikder Huq is a fourth year Computer Science PhD student at The University of Iowa. His research interests cover Distributed Systems, Distributed Algorithms and Computer Networks with a focus in Self-Adjustment and Self-Stabilization. Before joining the PhD program, Sikder worked as a lecturer of the Computer Science department at Stamford University Bangladesh.

Santanu Bhowmick - UI CS PhD CandidateSantanu Bhowmick

Talk: On the Approximability of Orthogonal Order Preserving Layout Adjustment

Given an initial placement of a set of rectangles in the plane, we consider the problem of finding a disjoint placement of the rectangles that minimizes the area of the bounding box and preserves the orthogonal order i.e., maintains the sorted ordering of the rectangle centers along both x-axis and y-axis with respect to the initial placement. This problem is known as Layout Adjustment for Disjoint Rectangles (LADR). It was known that LADR is NP-hard, but only heuristics were known for it. We show that a certain decision version of LADR is APX-hard, and give a constant factor approximation for LADR.

Bio: Santanu Bhowmick is a fourth year doctoral candidate in the Computer Science department at University of Iowa (UI). He is a Presidential Graduate Research Fellow, and he is currently working on Geometric Approximation Algorithms with his advisor, Prof. Kasturi Varadarajan. 

Farley Lai - UI CS PhD candidateFarley Lai

Talk: High Performance Stream Processing for Mobile Sensing Applications

Mobile sensing applications (MSAs) are an emerging class of mobile applications that take advantage of the increasing sensing, computational, storage, and networking capabilities of mobile devices. MSAs have broad application to domains such as intelligent transportation, environmental monitoring, and social networking. A key challenge for this class of applications is to process high-rate data streams in an energy-efficient manner. In this talk, I will present Efficient Static Memory management for Streaming (ESMS) – a novel approach to optimize the memory behavior of stream programs. The foundation of our approach is a static analysis technique capable of performing the whole program behavior to identify data sharing opportunities allowing to eliminate unnecessary memory operations and improve memory layout. Experimental results show up to 8.7X performance improvement and at most 96% reduction on memory usage compared to when programs were compiled using StreamIt.

Bio: Farley Lai is a Ph.D. candidate in Computer Science at the University of Iowa. He received the M.S. degree in Computer Science and Information Engineering in 2004 from the National Central University in Taiwan. Before coming to the University of Iowa, he had been working in the surveillance industry and led a project of developing video management software. His current research focuses on improving the performance and resource efficiency of mobile sensing applications through program analysis.

Yuanyuan Jiang - UI CS PhD CandidateYuanyuan Jiang

Talk: Using Virtual Environments to Study Pedestrian Road Crossing

Pedestrian injuries and deaths are a major public health concern. In 2014 alone, 4,743 pedestrians were killed and 76,000 were injured in the US.
Virtual environments provide a safe and controllable way to study road crossing. This talk will give a general introduction to the architecture of the Clara pedestrian VE simulator, and some of the recent experiments conducted in this simulator, including the influence of stereoscopic display, joint action, and texting alerts on road crossing behavior.

Bio: I am a 4th year Ph.D. student under the guidance of Prof. Joe Kearney, working with the pedestrian and bicycling simulator in the Hank Virtual Environment Lab. My research interest is in the exciting interdisciplinary area between computer science and cognitive psychology, especially the avatar fidelity and joint action in virtual environments.

Vivek Sardeshmukh - UI CS PhD candidateVivek Sardeshmukh

Talk: Distributed Graph Algorithms on the Congested Clique

Fundamental graph-theoretic problems such as computing a Minimum Spanning Tree (MST) frequently arise in science and engineering domains. In today’s era of Big Data, even problems such as MST which have efficient sequential algorithms are time consuming to solve due to the sheer scale of the graphs. One way around this problem is by means of distributed processing of the graphs. The goal is to design a distributed algorithm which solves the problem with minimum communication among the machines. Generally, we use two metrics to compare different algorithms for a problem: a) message complexity, and b) time complexity. In this talk, I will give an overview of special model of distributed computing called the Congested Clique. This model provides an abstraction of real-life computing frameworks such as cloud computing or MapReduce. I’ll end this talk by giving some insights on some recent results in this model and techniques used which might be of independent interest.

Bio: Vivek Sardeshmukh is a 5th year PhD Candidate and is working with Prof. Sriram Pemmaraju on distributed graph algorithms on the Congested Clique model. During his PhD, besides his research towards thesis he worked on large-scale processing for geospatial data, social network data, and molecular dynamics data with various research groups. Before joining the PhD program, he received his Master of Technology degree in 2011 from Indian Institute of Technology, Kharagpur. 

Zubair Shafiq - UI CS Assistant ProfessorKeynote Speaker Zubair Shafiq

Talk: Tracking, Surveillance, and Fraud in the Online Advertising Ecosystem

A large fraction of services on the Internet are supported using online ads. Service providers, such as Google and Facebook, rely on online advertising to support free services such as search, email, social networking, video, cloud storage, etc. In this talk, I plan to highlight two tussles in the online advertising ecosystem.

  1. Service providers track user activities, e.g., using cookies, to target customized ads. The ad ecosystem has come under fire recently. For example, Edward Snowden’s leaks revealed large-scale surveillance programs by government spy agencies that use cookies to profile individuals. Moreover, most ads degrade user experience and some even spread malware. The rise of ad blocking tools has created a tussle between end-users and content publishers.
  2. Online advertising ecosystem is also hampered by fraud. Click fraud is rampant in online display advertising. Many underground traffic exchanges provide fraudulent human traffic. Online social networks were supposed to solve this problem due to their trusted social nature. But online social networks are marred by fake accounts used for reputation manipulation. The prevalence of fake accounts has created a tussle between brands/advertisers and social network operators.


Bio: Zubair Shafiq is an assistant professor of computer science at the University of Iowa. He is part of the Iowa Informatics Initiative. He received Ph.D. in Computer Science from Michigan State University in 2014. His research interests are in the broad areas of networking and security, with a focus on large scale measurement and performance evaluation of mobile networks, content delivery networks, and online social networks. He received the 2012 IEEE International Conference on Network Protocols (ICNP) Best Paper Award. He also received the 2013 Fitch-Beach Outstanding Graduate Research Award at Michigan State University.



 MacLean Hall and Pappajohn Business Building



Getting to the Conference

Iowa City lies just off of Interstate 80 in Eastern Iowa. Regardless of whether you are coming from the West or the East, you will want to take exit 244 off of I-80 following Dubuque Street until you intersect with Church Street. Follow Church Street as it turns into Clinton Street and continue straight until you reach the downtown area and the Pentacrest (you will see the Old Capitol to the West), which is the heart of the University of Iowa's campus. All of the symposium will take place in that general vicinity in the Pappajohn Business Building and MacLean Hall. For a visual representation, see the map.