Department of Computer Science and Electrical Engineering

Dr. Rick Forno, CSEE’s Cybersecurity Graduate Program Director, was a presenter at the inaugural BSides Charm City technical security conference held at Howard County Community College in Columbia, MD over the weekend of 11-12 April 2015. His talk described what is needed to develop and operate viable high school and college student cyber-competition teams and framed around what he called the ‘POTS process’ — People, Organization, Technology, and Sustainability.

Several lessons learned from his four years overseeing the Maryland Cyber Challenge (MDC3) served as the basis for his presentation remarks, including the need to foster greater diversity and acceptance within cyber-competition teams — and by extension, the cybersecurity industry itself.

Baltimore City Teaching Residency – Final Deadline Extended to April 13

Baltimore City Teaching Residency trains UMBC graduates from a wide variety of majors and backgrounds to become exceptional, certified teachers for Baltimore City students in high-need communities.  It’s an honor and a tremendous responsibility, which is why we hold the highest standards of effectiveness of any teacher preparation program in America. 

Our 1-year program provides teacher training and certification while you work as a fulltime teacher, thus earning full salary and benefits.

Do you have what it takes to join this elite group of educators?

Click here – our final application deadline is Monday, April 13.  Have questions? Email anhthi.mouradov at tntp.org.

Our training program includes:

• 6-week pre-service training (Summer 2015, 5 days per week, fulltime hours)
• Weekly TNTP Academy training seminars (throughout the 2015-16 school year)
• Expert coaching to ensure your success throughout your first year teaching
• Extensive help and resources to secure your fulltime teaching position for the 2015-16 school year and beyond

UMBC's Professor Tim Oates has a column on the online TechCrunch site describing why we should Stop Fearing Artificial Intelligence. Professor Oates has 20 years of experience working with a wide range of AI technologies, including machine learning, robotics and natural language processing. In the piece, Dr. Oates explains that

"As yet another tech pioneer with no connection to artificial intelligence steps out to voice his fears about AI being catastrophic for the human race, I feel the need respond. … Conflating facts of technology's rapid progress with a Hollywood understanding of intelligent machines is provocative (honestly, it's a favorite in my most-loved science fiction books and movies), but this technology doesn't live in a Hollywood movie, it isn't HAL or Skynet, and it deserves a grounded, rational look.

and discusses some of the limitations of current intelligent systems like IBM's Watson. Like most AI researchers, he's a believer in Strong AI — the idea that there is no theoretical reason why a machine can not exhibit behavior as skillful and flexible as humans — but doubts the such machines will be neccessarily dangerous.

"But let's suppose, for a second, that an AI does learn to think intelligently outside its programming and that it’s become discontent. Would this superhuman intelligence inherently go nuclear, or would it likely just slack off a little at work or, in extreme cases, compose rap music in Latin? In a world filled with a nearly infinite number of things a thinking entity can do to placate itself, it's unlikely "destruction of humanity" will top any AI's list."

Stop Fearing Artificial Intelligence is a well written and thought provoking article.

Team HueBotics, a video-game development team at UMBC, is among the final four student teams competing to represent the U.S. in the Games division of the 2015 Microsoft Imagine World Cup competition. The teammates are (l. to r.) Jasmin Martin, Erika Shumacher, Tad Cordle, and Michael Leung. Source: Nicolas Deroin

UMBC President Freeman Hrabowski has a commentary article on CNBC, Video games in the classroom? Welcome to the future of learning, that talks about new ways to engage students in learning.

“Our university is headed to the “final four” — in game design. Next month, a team from the University of Maryland, Baltimore County (UMBC) will travel to San Francisco to compete against three other teams in the games category of the final U.S. round of the Microsoft Imagine Cup, a global student technology competition. The team will pitch its project to a panel of judges composed of Silicon Valley technology leaders and entrepreneurs. As the students vie for the honor of representing the U.S. internationally, they’re also showing us the future of teaching, learning, and careers.”

Dr. Hrabowski makes an important observations on collaborations between STEM the arts and STEM disciplines, the need for diversity and how to excite and inspire today’s students.

“The UMBC team reflects the American workplace of the near future, bringing together two men and two women from diverse racial and ethnic backgrounds. The team also illustrates the potential of “STEAM” collaborations, where science, technology, engineering, and math (STEM) are combined with art and design. Two members of the team are studying the computer sciences and two the visual arts, focusing on interactive media. … Moreover, Team Huebotics provides clues about how to improve education for students of all backgrounds. Too many young people today are bored at every level of education. And yet our student game developers voluntarily put in hundreds of hours on their winning creation. American education, from pre-K to college, must find ways to inspire similar dedication and to bring content to life. Digital environments are second nature to today’s young people. Playing well-designed games, as well as creating them, can pack an educational punch.”

Dr. Hrabowski also mentions the game Bandit (though not by name), in which you play a fox sneaking around civil war Baltimore in the time leading up to the Pratt Street Riot. This game, designed to teach about an important episode of civil war history, is being developed by a team of computer science and visual arts students in collaboration with students in history and music under the faculty guidance of professors Anne Rubin and Marc Olano, the director of UMBC’s Computer Science Game Development Track.

You can read Dr. Hrabowski’s full commentary piece online here.

PhD Dissertation Defense

Physical- and MAC-Layer Mechanisms for Increasing
Base-Station Anonymity in Wireless Ad-hoc Networks

John Ward

10:00am Monday, 13 April 2015, ITE 325b, UMBC

Wireless ad hoc networks have become valuable assets to both the commercial and military communities with applications ranging from industrial control on a factory floor to reconnaissance of a hostile border. In most applications, data sources forward information over multi-hop paths to a base station (BS). The BS not only serves as the data sink, but also provides other basic control and management features such as protocol synchronization, a gateway to other networks, and operator failure notifications, without which the network becomes dysfunctional. The critical role of the BS makes it a natural target for an adversary that desires to achieve the most impactful attack on the network. Even if an ad-hoc network employs conventional security mechanisms such as encryption and authentication, an adversary may apply traffic analysis techniques to identify the BS. This motivates a significant need for achieving improved BS anonymity to conceal its identity, role, and location. Traffic analysis countermeasures found in the literature have focused on the link and network layers and little attention has been given to the physical-layer (PHY) approaches.

In this dissertation, we address the challenges of BS anonymity by developing PHY and Medium Access Control (MAC) traffic analysis countermeasures. We first consider the limitations associated with evidence theory, the adversary’s primary traffic analysis attack model. We analyze the susceptibility of evidence theory to imperfect received signal strength (RSS) measurements. Next we extend the standard evidence theory approach to consider the contribution of acknowledgements to BS anonymity. We call this approach Acknowledgement Aware Evidence Theory (AAET) and describe the adversary’s initial survey phase which is based on a novel message correlation approach. Accurate synchronization is required by an ad-hoc network to employ PHY countermeasures; however, synchronization represents a fundamental design tradeoff, since the low-cost nodes and conservation of energy limit the achievable accuracy of synchronization within the network. We consider the impact of two popular synchronization protocols, Reference Broadcast Synchronization (RBS) and Timing-Synch Protocol for Sensor Networks (TPSN) on BS anonymity.

We develop a novel PHY BS anonymity-boosting approach based on distributed beamforming, which we call Distributed Beamforming protocol for increased BS ANonymity (DiBAN). DiBAN is a protocol that includes a cross-layer relay selection algorithm that a node employs to determine the most appropriate number of helper relays to participate in distributed beamforming at each hop. While effective at increasing BS anonymity, the overhead associated with DiBAN is in addition to any overhead already associated with existing ad hoc network protocols. We refine DiBAN using cross-layer design methodology to create an integrated distributed beamforming protocol called Link and Physical Cross-layer design for increased Anonymity (LiPCA) that increases BS anonymity with minor additional overhead by taking advantage of the underlying services that the MAC already provides. We use simulation to demonstrate the anonymity performance and energy-efficiency of our approaches and use the popular Sensor MAC (S-MAC) protocol as an exemplar MAC protocol. Results show that the cross-layer design of our LiPCA protocol achieves equivalent anonymity performance to DiBAN, but with an energy savings of approximately 35 percent.

Committee: Drs. Mohamed Younis (Chair), Charles Nicholas, Richard Forno, Ryan Robucci and Pedro Rodriguez (JHU/APL)

Ph.D. Dissertation Defense
Electrical Engineering

Simultaneous Polarization-Insensitive Phase-space
Trans-multiplexingand Wavelength Multicasting via
Cross-phase Modulation in a Photonic Crystal Fiber at 10 GBd

Brice Cannon

2:00pm Monday, 6 April 2015, ITE325b, UMBC

This thesis investigates the all-optical combination of amplitude and phase modulated signals into one unified multi-level phase modulated signal, utilizing the Kerr nonlinearity of cross-phase modulation (XPM). Predominantly, the first experimental demonstration of simultaneous polarization-insensitive phase-transmultiplexing and multicasting (PI-PTMM) will be discussed. The PI-PTMM operation combines the data of a single 10-Gbaud carrier-suppressed return-to-zero (CSRZ) on-off keyed (OOK) pump signal and 4×10-Gbaud return-to-zero (RZ) binary phase-shift keyed (BPSK) probe signals to generate 4×10-GBd RZ-quadrature phase-shift keyed (QPSK) signals utilizing a highly nonlinear, birefringent photonic crystal fiber (PCF). Since XPM is a highly polarization dependent nonlinearity, a polarization sensitivity reduction technique was used to alleviate the fluctuations due to the remotely generated signals’ unpredictable states of polarization (SOP). The measured amplified spontaneous emission (ASE) limited receiver sensitivity optical signal-to-noise ratio (OSNR) penalty of the PI-PTMM signal relative to the field-programmable gate array (FPGA) pre-coded RZ-DQPSK baseline at a forward-error correction (FEC) limit of 10-3 BER was ≈ 0.3 dB. In addition, the OSNR of the remotely generated CSRZ-OOK signal could be degraded to ≈ 29 dB/0.1nm, before the bit error rate (BER) performance of the PI-PTMM operation began to exponentially degrade. A 138-km dispersion-managed recirculating loop system with a 100-GHz, 13-channel mixed-format dense-wavelength-division multiplexed (DWDM) transmitter was constructed to investigate the effect of metro/long-haul transmission impairments. The PI-PTMM DQPSK and the FPGA pre-coded RZ-DQPSK baseline signals were transmitted 1,900 km and 2,400 km in the nonlinearity-limited transmission regime before reaching the 10-3 BER FEC limit. The relative reduction in transmission distance for the PI-PTMM signal was due to the additional transmitter impairments in the PCF that interact negatively with the transmission fiber.

Committee: Drs. Professor Gary M. Carter (Chair), William Astar, Anthony M. Johnson, Tinoosh Mohsenin, Thomas E. Murphy, Terrance L. Worchesky

Ph.D. Dissertation Defense
Computer Engineering

PSANDE: A Framework for Accurate Dynamic
Power Supply Analysis and Delay Estimation

Sushmita K. Rao

11:30am Friday, 3 April 2015, ITE 325b, UMBC

Power-supply noise is a major contributing factor for yield loss in sub-micron designs. Excessive switching in test mode causes supply voltage to droop more than in functional mode, leading to failures in delay tests that would not occur otherwise under normal operation. There exists a need to accurately estimate on-chip supply noise early in the design phase to meet power requirements in normal mode and during test to prevent over-stimulation during testing and avoid false failures. Simultaneous switching activity (SSA) of several logic components is one of the main sources of power-supply noise (PSN) which results in reduction of supply voltages at the power-supplies of the logic gates. Current research concentrates on static IR-drop, which accounts for only part of the total voltage drop on the power grid and therefore is insufficient for nanometer designs. Inductive drop is not included in current noise analysis techniques for simplification.

The power delivery networks in today’s very deep-submicron chips are susceptible to slight variations and cause sudden large current spikes leading to higher Ldi/dt drop than resistive drop, necessitating the need to be accounted. Especially of concern is simultaneous switching in localized areas in a chip because it concentrates current drawn on a particular power bump further reducing supply voltage. Thus, there arises a growing need to accurately characterize the resistive and inductive voltage drop caused by simultaneous switching of multiple paths. Power-supply noise also impacts circuit operation, causing a significant increase in path delays. It is critical to account for this increase in delay during the ATPG process otherwise it can lead to overkill during transition and delay testing. However, it is infeasible to carry out full-chip SPICE-level simulations on a design to validate the large number of ATPG generated test patterns. Accurate and efficient techniques are required to quantify supply noise and its impact on path delays to ensure reliable operation in both mission mode and during test.

A scalable current-based dynamic method is presented to estimate both IR and Ldi/dt drop caused by simultaneous switching activity. Also presented is a technique to predict the increase in path delays caused by supply noise. The noise and delay estimation techniques use simulations of individual extracted switching logic in comparison to time-consuming full-chip simulations and thus it can be integrated with existing ATPG tools. A design partitioning technique is also presented that makes the framework feasible for larger designs. Supply noise estimation error is less than 12% of SPICE level full-chip results across all test cases in the combinational and sequential benchmark circuits. The effect of power supply noise on path delays is modeled effectively. Results from multiple designs show that using the convolution-based technique the increase in path delay can be accurately predicted with a worst case error of 4% as compared to full-chip simulation results demonstrating the effectiveness of the technique.

Committee: Drs. Chintan Patel (Chair), Dhananjay Phatak, Ryan Robucci, Nilanjan Banerjee and Ismed Hartanto (Xilinx)

ENEE MS Thesis Defense

Graph-Theoretical Analysis using Data-Driven Features:
Application to Rehabilitation After Stroke

Jonathan Laney

1:30pm Friday, 3 April 2015, ITE 346, UMBC

The assessment of neuroplasticity after stroke through functional magnetic resonance imaging (fMRI) analysis is a developing field where the objective is to better understand the neural process of recovery and to better target rehabilitation interventions. In this study, the connectivity structure of the stroke-affected brain is analyzed before and after a rehabilitation intervention. The challenge associated with our fMRI data stems from the large amount of individual spatial variability exhibited by the dataset and the need to summarize entire brain maps by generating simple, yet discriminating features, to highlight differences in patients’ functional connectivity. The comparison of algorithms in terms of their ability to capture spatial variability for each subject is not straightforward due to the lack of a ground truth for real fMRI data.

We provide a graph-theoretical (GT) framework to effectively make such a comparison for real data. We investigate and discuss the important role of order selection for data that exhibits large amounts of subject variability. Furthermore, we demonstrate that Independent vector analysis (IVA) provides superior performance in preserving subject variability when compared with widely used methods such as group independent component analysis. We pair IVA with GT analysis to produce discriminative features, which highlight neuroplastic changes between the groups before and after intervention. Resulting GT features are shown to capture connectivity changes that are not evident through direct comparison of the group t-maps, i.e., brain maps obtained by a t-test taken across subjects’ spatial brain maps. Additionally, we compare the responders to the intervention with the non-responders and demonstrate that their relative improvements, as shown through our fMRI analysis, correspond to clinical findings. In this study, increased small worldness across components and greater centrality in key motor networks are demonstrated as a result of the intervention, suggesting improved efficiency in neural communication. Clinically, these results bring forth new possibilities as a means to observe the neural processes underlying improvements in motor function.

Committee: Drs. Tulay Adali (Chair), Joel Morris, Chuck LaBerge, Kelly Westlake and Charles Cavalcante

Ph.D. Dissertation Defense

Rayleigh-Scattering-Induced Noise in Analog RF-Photonic Links

James Cahill

3:00pm Tuesday, 7 April 2015, ITE 325b

Analog RF-photonic links hold the potential to increase the precision of time and frequency synchronization in commercial applications by orders of magnitude. However, current RF-photonic links that are used for synchronization must suppress optical-fiber-induced noise by using active feedback schemes that are incompatible with most existing fiber-optic networks. Unless this noise can be suppressed using different methods, RF-photonic time and frequency synchronization will remain accessible only to the research community. As a first step towards identifying alternate means of suppressing the optical-fiber-induced noise, this thesis presents an extensive experimental characterization and limited theoretical discussion of the dominant optical-intensity and RF-phase noise source in a laboratory setting, where environmental fluctuations are small. The experimental results indicate that the optical-fiber-induced RF-phase noise and optical-intensity noise are caused by the same physical mechanism. The experimental results demonstrate that this mechanism is related to the laser phase noise but not the laser intensity noise. The bandwidth of the optical-fiber-induced noise depends on the optical fiber length for lasers with low phase noise, while for lasers with high phase noise, the bandwidth is constant. I demonstrate that the optical-intensity and RF-phase noise can be mitigated without active feedback by dithering the laser frequency. Based on these results, I hypothesize that interference from Rayleigh scattering is the underlying mechanism of the optical-intensity and RF-phase noise. The literature predicts that the noise induced by this process will have a bandwidth that is proportional to the laser linewidth and constant with respect to the optical fiber length, for lasers with high-phase noise, which is consistent with the experimental results. I derive a simplified model that is valid for low-phase-noise lasers. I compare this model with the experimental results and find that it matches the optical-fiber-length-dependent bandwidth measured for low-phase-noise lasers.

Committee: Drs. Gary Carter (Chair), Curtis Menyuk, Fow-sen Choa, Olukayode Okusaga, Weimin Zhou

The UMBC ACM Student Chapter invites you to Hi Tea this week. Mingle, network, discuss research and ideas, explore opportunities to collaborate and treat yourself to a snack while you’re at it. Faculty, staff and students across the computer science, electrical engineering, computer engineering and cybersecurity programs are encouraged to participate.  Friends of the department are also welcome.

Date: Friday, April 3, 2015
Time: 3:00 p.m.- 4:00 p.m.
Location: CSEE hallway outside ITE 325
Hosted by: Chi Zhang

If you or your lab are interested in volunteering for or hosting Hi Tea, please contact Genaro Hernandez Jr. at genaroh1 @ umbc.edu. We need volunteers for 4/17/15 and 4/24/15.