CSEE Ph.D. student Kavita Krishnaswamy will give a talk entitled Robotics for Independence sponsored by Refresh Baltimore on May 20 at 7:00pm. The talk will be given at Betamore, 1111 Light Street in Baltimore. Refreshments at 6:30, RSVP online.

Robotics for Independence

Kavita Krishnaswamy

7:00pm Wednesday, 20 May 2015
Betamore, 1111 Light St., Baltimore

The future is here! In this talk, Kavita will discuss the development of robotic systems and how they provide assistance and increase independence for people with disabilities. Kavita will introduce several prototype robotic systems that support transferring, repositioning, and personal care, and focus on accessible user interfaces for control that are feasible for persons with severe disabilities.

Kavita Krishnaswamy is a Ph.D. candidate in Computer Science at the University of Maryland, Baltimore County working with Dr. Tim Oates. As a professional researcher with a physical disability, Kavita is motivated by a powerful, innate force: autonomy is the soul of independent daily living that is achieved with the advancement of technology. She is both a Ford Foundation Predoctoral and National Science Foundation Graduate Research Fellow. Kavita has worked at the National Science Foundation's Engineering Research Center – Quality of Life Technology Center (QoLT) in Carnegie Mellon and University of Pittsburgh and IBM Business consulting services.

Refresh Baltimore describes itself as "a community made up of sharp design and development professionals, creative minds and Baltimore technologists looking to learn from one another and apply critical thinking to the industry."

The UMBC Cybersecurity Graduate Program will hold a virtual information session at 6:00pm on June 16. Participate to learn about the  program options and find out how a master’s degree or graduate certificate can help you advance in the cybersecurity industry. During the online information session, graduate program director Richard Forno will discuss courses, credit requirements and prerequisites, and admissions processes.

The session will cover cybersecurity programs at both UMBC's Main Campus and UMBC-Shady Grove in Rockville, MD. It will provide an overview of our innovative curriculum, practice-oriented instruction and flexible class schedules, which are designed for working professionals.  You will also learn about admissions, curriculum, class format and the cybersecurity career outlook.

If you would like to participate in the information session, please RSVP online.

Mobile Computing and Smart Home
Automation Systems Demonstrations

UMBC Students in CMSC 628 and 691

12:00-1:30pm Tuesday, 12 May 2015
Third floor main corridor, ITE Building

The students in UMBC's graduate Introduction to Mobile Computing class and Systems for Smart Home Automation course will showcase their cutting-edge projects and application that use mobile phones, tablets, cloudservices and smarthome sensors.

Come and enjoy the demonstrations that range from cool smartphone games to smartphone-based educational tools to location‐based mobile phone services to voice and mind controlled home appliances.

For more information, contact Prof. Nilanjan Banerjee at .

Ph.D. Dissertation Defense

A Semantic Resolution Framework for Integrating
Manufacturing Service Capability Data

Yan Kang

10:00am Monday 27 April 2015, ITE 217b

Building flexible manufacturing supply chains requires availability of interoperable and accurate manufacturing service capability (MSC) information of all supply chain participants. Today, MSC information, which is typically published either on the supplier’s web site or registered at an e-marketplace portal, has been shown to fall short of interoperability and accuracy requirements. The issue of interoperability can be addressed by annotating the MSC information using shared ontologies. However, this ontology-based approach faces three main challenges: (1) lack of an effective way to automatically extract a large volume of MSC instance data hidden in the web sites of manufacturers that need to be annotated; (2) difficulties in accurately identifying semantics of these extracted data and resolving semantic heterogeneities among individual sources of these data while integrating them under shared formal ontologies; (3) difficulties in the adoption of ontology-based approaches by the supply chain managers and users because of their unfamiliarity with the syntax and semantics of formal ontology languages such as the web ontology language (OWL).

The objective of our research is to address the main challenges of ontology-based approaches by developing an innovative approach that is able to extract MSC instances from a broad range of manufacturing web sites that may present MSC instances in various ways, accurately annotate MSC instances with formal defined semantics on a large scale, and integrate these annotated MSC instances into formal manufacturing domain ontologies to facilitate the formation of supply chains of manufacturers. To achieve this objective, we propose a semantic resolution framework (SRF) that consists of three main components: a MSC instance extractor, a MSC Instance annotator and a semantic resolution knowledge base. The instance extractor builds a local semantic model that we call instance description model (IDM) for each target manufacturer web site. The innovative aspect of the IDM is that it captures the intended structure of the target web site and associates each extracted MSC instance with a context that describes possible semantics of that instance. The instance annotator starts the semantic resolution by identifying the most appropriate class from a (or a set of) manufacturing domain ontology (or ontologies) (MDO) to annotate each instance based on the mappings established between the context of that instance and the vocabularies (i.e., classes and properties) defined in the MDO. The primary goal of the semantic resolution knowledge base (SR-KB) is to resolve semantic heterogeneity that may occur in the instance annotation process and thus improve the accuracy of the annotated MSC instances. The experimental results demonstrate that the instance extractor and the instance annotator can effectively discover and annotate MSC instances while the SR-KB is able to improve both precision and recall of annotated instances and reducing human involvement along with the evolution of the knowledge base.

Committee: Drs. Yun Peng (Chair), Tim Finin, Yaacov Yesha, Matthew Schmill and Boonserm Kulvatunyou

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.