Scholarly Works, Electrical and Computer Engineering
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Browsing Scholarly Works, Electrical and Computer Engineering by Content Type "Conference proceeding"
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- Adversarial Unlearning of Backdoors via Implicit HypergradientZeng, Yi; Chen, Si; Park, Won; Mao, Morley; Jin, Ming; Jia, Ruoxi (2022)We propose a minimax formulation for removing backdoors from a given poisoned model based on a small set of clean data. This formulation encompasses much of prior work on backdoor removal. We propose the Implicit Bacdoor Adversarial Unlearning (I-BAU) algorithm to solve the minimax. Unlike previous work, which breaks down the minimax into separate inner and outer problems, our algorithm utilizes the implicit hypergradient to account for the interdependence between inner and outer optimization. We theoretically analyze its convergence and the generalizability of the robustness gained by solving minimax on clean data to unseen test data. In our evaluation, we compare I-BAU with six stateof- art backdoor defenses on seven backdoor attacks over two datasets and various attack settings, including the common setting where the attacker targets one class as well as important but underexplored settings where multiple classes are targeted. I-BAU’s performance is comparable to and most often significantly better than the best baseline. Particularly, its performance is more robust to the variation on triggers, attack settings, poison ratio, and clean data size. Moreover, I-BAU requires less computation to take effect; particularly, it is more than 13X faster than the most efficient baseline in the single-target attack setting. Furthermore, it can remain effective in the extreme case where the defender can only access 100 clean samples—a setting where all the baselines fail to produce acceptable results.
- AI-Powered Real-Time Channel Awareness and 5G NR Radio Access Network Scheduling OptimizationWang, Ying; Gorski, Adam; DaSilva, Luiz A. (IEEE, 2021-04-19)As with any other wireless technology, 5G is not immune to jamming. To achieve consistent performance, network resource scheduling must be optimized in a way that reacts to jamming in the NR channel environment. This paper presents a cognitive system for real-time Channel Awareness and Radio Access Network (RAN) Scheduling (CARS) optimization based on multi-dimensional temporal machine learning models. Our system automatically detects and classifies jamming in the channel environment and optimizes scheduling based on classification results and collected link parameters. Based on over-the-air (OTA) experiments, detection and classification time is less than 0.8 seconds, which enables real-time optimization. The system is evaluated and verified for OTA experimentation through integration to our end-to-end NR system. An Automated Jamming Module (AJM) is designed and implemented. Connecting the AJM to our NR system enables a comprehensive evaluation environment for our Jamming Detection and Classification Model (JDCM) and Modulation and Coding Scheme optimization model. The improvement in connection resiliency against Control Resource Set jamming is proof of the CARS concept for real-time channel awareness and scheduling optimization. Depending on channel conditions, CARS achieves a 30% or higher improvement in NR system throughput.
- An Architecture for Electronic TextilesJones, Mark T.; Martin, Thomas L.; Sawyer, Braden (ICST, 2008)This paper makes a case for a communication architecture for electronic textiles (e-textiles). The properties and re- quirements of e-textile garments are described and analyzed. Based on these properties, the authors make a case for em- ploying wired, digital communication as the primary on- garment communication network. The implications of this design choice for the hardware architecture for e-textiles are discussed.
- Autofocusing in optical scanning holographyKim, Taegeun; Poon, Ting-Chung (Optical Society of America, 2009-12-01)We present autofocusing in optical scanning holography (OSH) with experimental results. We first record the complex hologram of an object using OSH and then create the Fresnel zone plate (FZP) that codes the object constant within the depth range of the object using Gaussian low-pass filtering. We subsequently synthesize a real-only spectrum hologram in which its phase term contains information about a distance parameter. Finally, we extract the distance parameter from the real-only spectrum hologram using fringe-adjusted filtering and the Wigner distribution. Using the extracted distance parameter, we reconstruct a three-dimensional image of the object from the complex hologram using digital convolution, which bypasses the conventional blind convolution to reconstruct a hologram. To the best of our knowledge, this is the first report with experimental results that autofocusing in OSH is possible without any searching algorithm or tracking process. (C) 2009 Optical Society of America
- Beyond Finding Change: multitemporal Landsat for forest monitoring and managementWynne, Randolph H.; Thomas, Valerie A.; Brooks, Evan B.; Coulston, J. O.; Derwin, Jill M.; Liknes, Greg C.; Yang, Z.; Fox, Thomas R.; Ghannam, S.; Abbott, A. Lynn; House, M. N.; Saxena, R.; Watson, Layne T.; Gopalakrishnan, Ranjith (2017-07)Take homes
- Tobler’s Law still in effect with time series – spatial autocorrelation in temporal coherence can help in both preprocessing and estimation
- Continual process improvement in extant algorithms needed
- Need additional means by which variations within (parameterization) and across algorithms addressed (the Reverend…)
- Time series improving higher order products (example with NLCD TCC) enabling near continuous monitoring
- Blockchain-Enabled Next Generation Access ControlDong, Yibin; Mun, Seong K.; Wang, Yue (Springer, 2022-01-01)In the past two decades, longitudinal personal health record (LPHR) adoption rate has been low in the United States. Patients’ privacy and security concerns was the primary negative factor impacting LPHR adoption. Patients desire to control the privacy of their own LPHR in multiple information systems at various facilities. However, little is known how to model and construct a scalable and interoperable LPHR with patient-controlled privacy and confidentiality that preserves patients’ health information integrity and availability. Understanding this problem and proposing a practical solution are considered important to increase LPHR adoption rate and improve the efficiency as well as the quality of care. Even though having the state-of-the-art encryption methodologies being applied to patients’ data, without a set of secure access control policies being implemented, LPHR patient data privacy is not guaranteed due to insider threats. We proposed a definition of “secure LPHR” and argued LPHR is secure when the security and privacy requirements are fulfilled through adopting an access control security model. In searching for an access control model, we enhanced the National Institute of Standards and Technology (NIST) next generation access control (NGAC) model by replacing the centralized access control policy database with a permissioned blockchain peer-to-peer database, which not only eases the race condition in NGAC, but also provides patient-managed access control policy update capability. We proposed a novel blockchain-enabled next generation access control (BeNGAC) model to protect security and privacy of LPHR. We sketched BeNGAC and LPHR architectures and identified limitations of the design.
- Brief announcement: Crystalline: Fast and memory efficient wait-free reclamationNikolaev, Ruslan; Ravindran, Binoy (2021-10-01)We present a new wait-free memory reclamation scheme, Crystalline, that simultaneously addresses the challenges of high performance, high memory efficiency, and wait-freedom. Crystalline guarantees complete wait-freedom even when threads are dynamically recycled, asynchronously reclaims memory in the sense that any thread can reclaim memory retired by any other thread, and ensures (an almost) balanced reclamation workload across all threads. The latter two properties result in Crystalline’s high performance and high memory efficiency, a difficult trade-off for most existing schemes. Our evaluations show that Crystalline exhibits outstanding scalability and memory efficiency, and achieves superior throughput than state-of-the-art reclamation schemes as the number of threads grows.
- Building a Statewide Experiential Learning Portfolio in CybersecurityDaSilva, Luiz A.; Durant, Liza Wilson; Mason, Jordan; Hayes, Sarah (2023-06-25)The growing workforce gap in cybersecurity, with an estimated 770 thousand job openings across the country, poses economic and national security risks. Meanwhile, women, African Americans, Native Americans, and Latinos are significantly underrepresented in the cyber workforce. With these two challenges in mind, and informed by research findings that experiential learning opportunities correlate with multiple positive job outcomes, we have built a statewide experiential learning portfolio open to students in more than 40 two-year and four-year colleges and universities across Virginia. Programs in our experiential learning portfolio generally fall under one of five categories: transdisciplinary experiential learning; internships; traineeships; cybersecurity competitions; and intensive training coupled with professional development activities. In this paper, we describe the structure of these programs and associated metrics. Early results indicate very high interest by students and employers, high retention rates in cybersecurity careers, and gains in participation by underrepresented groups.
- Cascode GaN HEMT Gate Driving AnalysisHeumesser, V.; Lai, J. S.; Hsieh, H. C.; Hsu, J.; Yang, C. Y.; Chang, E. Y.; Liu, C. Y.; Chieng, W. H.; Hsieh, Y. T. (IEEE, 2023-01-01)The aim of this paper is to analyze the conventional cascode gate driving to understand the switching transition and to provide a design guide for the GaN HEMT and its associated packaging. A double-pulse tester has been designed and fabricated with minimum parasitic inductance to avoid unnecessary parasitic ringing. The switching behaviors in both turn-on and -off are analyzed through topological study and explained through SPICE simulation. Two different cascode devices were tested to show the impact of threshold voltage and low-voltage Si MOSFET selection.
- CCI xG Testbed: Enabling End-to-End ORAN and CBRS ExperimentationDaSilva, Luiz A. (2023-11-14)
- Collaborative Multi-Robot Multi-Human Teams in Search and RescueWilliams, Ryan K.; Abaid, Nicole; McClure, James; Lau, Nathan; Heintzman, Larkin; Hashimoto, Amanda; Wang, Tianzi; Patnayak, Chinmaya; Kumar, Akshay (2022-04-30)Robots such as unmanned aerial vehicles (UAVs) deployed for search and rescue (SAR) can explore areas where human searchers cannot easily go and gather information on scales that can transform SAR strategy. Multi-UAV teams therefore have the potential to transform SAR by augmenting the capabilities of human teams and providing information that would otherwise be inaccessible. Our research aims to develop new theory and technologies for field deploying autonomous UAVs and managing multi-UAV teams working in concert with multi-human teams for SAR. Specifically, in this paper we summarize our work in progress towards these goals, including: (1) a multi-UAV search path planner that adapts to human behavior; (2) an in-field distributed computing prototype that supports multi-UAV computation and communication; (3) behavioral modeling that yields spatially localized predictions of lost person location; and (4) an interface between human searchers and UAVs that facilitates human-UAV interaction over a wide range of autonomy.
- Color Invariant Skin SegmentationXu, Han; Sarkar, Abhijit; Abbott, A. Lynn (IEEE, 2022-06)This paper addresses the problem of automatically detecting human skin in images without reliance on color information. A primary motivation of the work has been to achieve results that are consistent across the full range of skin tones, even while using a training dataset that is significantly biased toward lighter skin tones. Previous skin-detection methods have used color cues almost exclusively, and we present a new approach that performs well in the absence of such information. A key aspect of the work is dataset repair through augmentation that is applied strategically during training, with the goal of color invariant feature learning to enhance generalization. We have demonstrated the concept using two architectures, and experimental results show improvements in both precision and recall for most Fitzpatrick skin tones in the benchmark ECU dataset. We further tested the system with the RFW dataset to show that the proposed method performs much more consistently across different ethnicities, thereby reducing the chance of bias based on skin color. To demonstrate the effectiveness of our work, extensive experiments were performed on grayscale images as well as images obtained under unconstrained illumination and with artificial filters. Source code: https://github.com/HanXuMartin/Color-Invariant-Skin-Segmentation
- Communications in Electronic Textile SystemsNakad, Z.; Jones, M.; Martin, T. (2003)Electronic textiles (e-textiles) are emerging as a novel method for constructing electronic systems in wearable and large area applications. This new type of processing system merges textile and electronic technologies. This paper studies the communication requirements between the computing and sensing elements of an e-textile. This communication is studied through the construction of a prototype as well as through modeling and simulation. A new algorithm based on token grid schemes is presented that takes advantage of the e-textile physical configuration.
- Comparative Dimensions of Disciplinary CultureMartin, Thomas L.; McNair, Lisa D.; Paretti, Marie C. (ASEE, 2015)Despite calls to promote creativity as “an indispensable quality for engineering” [1], the U.S. engineering educational system has been slow to develop pedagogies that successfully promote innovative behaviors. Engineers need more creativity and interdisciplinary fluency, but engineering instructors often struggle to provide such skills without sacrificing discipline-specific problem-solving skills. At the same time, engineering programs continue to struggle with attracting and retaining members of underrepresented populations—populations whose diversity could greatly contribute to innovation. Interestingly, the lack of diversity in engineering is often attributed to cultural traits of the field, which is often characterized as masculine, individualistic, and function-oriented. To address these issues, we have undertaken a 3-year study to investigate patterns of cultural traits in students across disciplines, and to build an actionable theory of engineering culture that can support pedagogies of inclusive and collaborative innovation as well as strategies for recruiting and retention efforts. In this paper, we present preliminary results from our survey in order to define how Hofstede’s dimensions of national culture map to 14 majors in a research university. Specifically, we are applying Hofstede’s original four dimensions of national business cultures (power distance, uncertainty avoidance, individualism, masculinity) [2] to academic disciplines to explain how students develop skills to operate within and across disciplinary boundaries. To do so, we are addressing the following research questions: 1. How do Hofstede’s dimensions of national cultures map to academic disciplines? 2. Do different majors have different disciplinary cultures according to Hofstede’s dimensions? This research purpose is to understand how students in different disciplines behave and perceive their majors. The information presented builds up on a pilot study where we applied Hofstede’s instrument with no major findings. However, we improved the survey based on the responses and expanded it outside engineering majors.
- Covert and Quantum-Safe Tunneling of Multi-Band Military-RF Communication Waveforms Through Non-Cooperative 5G NetworksAlwan, Elias; Volakis, John; Islam, Md Khadimul; De Silva, Udara; Madanayake, Arjuna; Sanchez, Jose Angel; Sklivanitis, George; Pados, Dimitris A.; Beckwith, Luke; Azarderakhsh, Reza; Muralkrishan, Madhuvanti; Rastogi, Rishabh; Hore, Aniruddha; Burger, Eric W. (IEEE, 2023)We have built a prototype universal radio adapter which furnishes seamless and secure wireless communication through non-cooperative indigenous 5G networks for military and government users. The adapter consists of a waveform-agnostic hardware add-on that tunnels DoD terrestrial and satellite data. The adapter uses secure protocols for cross-connecting military-grade wireless RF communications equipment using spectrum in the range from UHF to Ka-band. A 5G data transport channel replaces the captured spectrum for transporting information at the IQ-sample level. In a sense, we replace the antenna-air interface and wireless channel with a transparent 5G data network. A plurarity of legacy military systems can operate through modern 5G networks in a seamless way without any knowledge of the characteristics of military waveforms. The adapter incorporates AI/ML based methods for smart spectrum sensing and autonomous radio reconfiguration. This enables intelligent interconnection of a number of military radios through non-cooperative (potentially adversarial) 5G commercial cellular networks. The adapter is built on four technical pillars: 1) ultra-wideband apertures for multi-functional and flexible software-defined radios (SDRs) with agile, wideband, and dual-band tunable RF transceivers for FR1/FR2 bands; 2) physical layer operation that involve device authentication via deep-learning based RF fingerprinting and compression of acquired IQ data; 3) secure and reconfigurable cryptographic co-processors employing the new quantum-safe algorithms selected by NIST to achieve authentication, key exchange, and encryption with focus on resource-constrained low size, weight, power, and cost (SWaP-C) devices; and 4) generative artificial intelligence and spread-spectrum steganography to hide DoD traffic passed through 5G networks and improve resiliency against real-time traffic analysis by nation-state carriers and intelligence agencies.
- D-Mode GaN HEMT with Direct DriveHeumesser, V.; Lai, J. S.; Hsieh, H. C.; Hsu, J.; Yang, C. Y.; Chang, E. Y.; Ko, H. K.; Liu, W. H.; Lin, Y. M. (IEEE, 2023-01-01)A direct-driven gate driver circuit has been developed for the depletion-mode gallium nitride (d-mode GaN) high electron mobility transistor (HEMT), which is a'normally on'' device and is typically connected in series with a low-voltage power MOSFET to prevent shoot-through faults. The switching of such a''cascode'' device is substantially delayed due to a large MOSFET input capacitance. This paper introduces a charge-pump based direct-driven approach to provide a negative voltage in the gate drive loop so that the device becomes 'normally off The switching characteristics of the direct-driven HEMT is analyzed through computer simulation and hardware testing. Results indicate that the switching delays due to MOSFET gating is eliminated, and the voltage slew rate can be directly controlled by the gate resistance.
- A Derivative-Free Observability Analysis Method of Stochastic Power SystemsZheng, Zongsheng; Xu, Yijun; Mili, Lamine M.; Liu, Zhigang; Korkali, Mert; Wang, Yuhong (IEEE, 2021)The observability analysis of a time-varying nonlinear dynamic model has recently attracted the attention of power engineers due to its vital role in power system dynamic state estimation. Generally speaking, due to the nonlinearity of the power system dynamic model, the traditional derivative-based observability analysis approaches either rely on the linear approximation to simplify the problem or require a complicated derivation procedure that ignores the uncertainties of the dynamic system model and of the observations represented by stochastic noises. Facing this challenge, we propose a novel polynomial-chaos-based derivative-free observability analysis approach that not only brings a low complexity, but also enables us to quantify the degree of observability by considering the stochastic nature of the dynamic systems. The excellent performances of the proposed method is demonstrated using simulations of a decentralized dynamic state estimation performed on a power system using a synchronous generator model with IEEE-DC1A exciter and a TGOV1 turbine-governor.
- Distributed Storage Systems with Secure and Exact Repair - New ResultsTandon, Ravi; Amuru, SaiDhiraj; Clancy, Thomas Charles III; Buehrer, R. Michael (IEEE, 2014-02)Distributed storage systems (DSS) in the presence of a passive eavesdropper are considered in this paper. A typical DSS is characterized by 3 parameters (n, k, d) where, a file is stored in a distributed manner across n nodes such that it can be recovered entirely from any k out of n nodes. Whenever a node fails, d ∈ [k, n) nodes participate in the repair process. In this paper, we study the exact repair capabilities of a DSS, where a failed node is replaced with its exact replica. Securing this DSS from a passive eavesdropper capable of wiretapping the repair process of any l < k nodes, is the main focus of this paper. Specifically, we characterize the optimal secure storagevs- exact-repair-bandwidth tradeoff region for the (4, 2, 3) DSS when l = 1 and the (n, n − 1, n − 1) DSS when l = n − 2.
- Dynamics of mid-latitude sporadic-E and its impact on HF propagation in the North American sectorKunduri, Bharat Simha Reddy; Erickson, Philip; Baker, Joseph; Ruohoniemi, John (American Geophysical Union, 2023-09-16)Sporadic-E (Es) are thin layers of enhanced ionization observed in the E-region, typically between 95 and 120 km altitude. Es plays an important role in controlling the dynamics of the upper atmosphere and it is necessary to understand the geophysical factors influencing Es from both the scientific and operational perspectives. While the wind-shear theory is widely accepted as an important mechanism responsible for the generation of Es, there are still gaps in the current state of our knowledge. For example, we are yet to determine precisely how changes in the dynamics of horizontal winds impact the formation, altitude, and destruction of Es layers. In this study, we report results from a coordinated experimental campaign between the Millstone Hill Incoherent Scatter Radar, the SuperDARN radar at Blackstone, and the Millstone Hill Digisonde to monitor the dynamics of mid-latitude Es layers. We report observations during a 15-hr window between 13 UT on 3 June 2022 and 4 UT on 4 June 2022, which was marked by the presence of a strong Es layer. We find that the height of the Es layer is collocated with strong vertical shears in atmospheric tides and that the zonal wind shears play a more important role than meridional wind shears in generating Es, especially at lower altitudes. Finally, we show that in the presence of Es, SuperDARN ground backscatter moves to closer ranges, and the height and critical frequency of the Es layer have a significant impact on the location and intensity of HF ground scatter.
- e-TAGs: e-Textile Attached GadgetsLehn, David I.; Neely, Craig W.; Schoonover, Kevin; Martin, Thomas L.; Jones, Mark T. (Society for Computer Simulation, 2004)The integration of wires and electronics into textiles (e-textiles) has many potential applications for wearable and pervasive computing. Textiles are an integral part of everyday life, from clothing we wear to the carpet we walk upon. Being able to combine electronics with textiles would enable pervasive computing to blend into the background so that the user can go about a normal routine. One of the challenges in e-textile implementation is connecting the electronic components to the fabric cheaply and reliably. This paper describes the design and implementation issues of e-Textile Attached Gadgets (e-TAGs). E-TAGs can use a variety of methods to connect to wires in an etextile. This design allows for e-textile electronics modules that are easily attachable, removable, replaceable, and interchangeable. This paper presents the system architecture, connection techniques, communication alternatives, and experiences from the construction of a prototype wearable e-textile with multiple e-TAGs.