Aerial robotics have become ubiquitous, but (like most robots) they still struggle to operate at high speed in unstructured, cramped environments. By considering a vehicle's mechanical design simultaneously with the design of controls and automation algorithms, we have more degrees of freedoms to find creative solutions to problems. In this talk I will present some […]
Climate change is a societal and political problem whose impact could be mitigated by technology. Underlying many of its technical challenges is a surprisingly simple yet challenging problem; modeling the interaction of atoms. In this talk, we motivate the problem and provide insights into how this opens up new intriguing directions for machine learning and […]
ABSTRACT: “Does generative AI infringe copyright?” is an urgent question. It is also a difficult question, for two reasons. First, “generative AI” is not just one product from one company. It is a catch-all name for a massive ecosystem of loosely related technologies. These systems behave differently and raise different legal issues. Second, copyright law […]
This is a hybrid event with in-person attendance in Levine 307 and virtual attendance on Zoom. ABSTRACT Countless science fiction works have set our expectations for small, mobile, autonomous robots for use in a broad range of applications. The ability to move through highly dynamic and complex environments can expand capabilities in search and rescue […]
The ability to modulate pathogenic proteins represents a powerful treatment strategy for diseases. Unfortunately, many proteins are considered "undruggable" by small molecules, and are often intrinsically disordered, precluding the usage of structure-based tools for binder design. To address these challenges, we have developed a suite of algorithms that enable the design of target-specific peptides via […]
In this talk we will discuss how to engineer the dispersion relation of photonic platforms to provide robust propagation of classical and quantum states of light. In the first part of this talk, we will unveil how to leverage the interaction of nonlinearity with higher orders of dispersion to create novel types of solitons, wave […]
This is a HYRBID event with a VIRTUAL SPEAKER. The GRASP on Robotics Seminar will be streamed for in-person attendees in Wu and Chen and virtual attendees may join the talk via Zoom. ABSTRACT Every team has top performers -- people who excel at working in a team to find the right solutions in complex, difficult […]
Many microorganisms and cells function in complex (non-Newtonian) fluids, which are mixtures of different materials that exhibit both viscous and elastic stresses. For example, mammalian sperm swim through cervical mucus on their journey through the female reproductive tract, and they must penetrate the viscoelastic gel outside the ovum to fertilize. In micro-scale swimming the dynamics […]
Recent years have witnessed tremendous growth in the capabilities of legged robots, with quadrupeds and humanoids demonstrating athletic behaviors that even five years ago were out of reach. Likewise, actively powered lower-limb assistive devices have made great strides in their maturity, with hardware such as the Open-Source Leg broadening access for future breakthroughs. Despite this […]
The Department of Bioengineering at the University of Pennsylvania and Dr. Dennis Discher are pleased to announce the Doctoral Dissertation Defense of Michael Tobin. Title: Physiologically Induced High Gaussian Curvature Drives Nuclear Lamina Rupture and Cytoskeletal Displacement—Contributing to Downstream Dysfunction Date: Tuesday, November 7, 2023 Time: 10AM Location: Glandt Forum at the Singh Center. There […]
The Department of Bioengineering at the University of Pennsylvania and Dr. Max Kelz are pleased to announce the Doctoral Dissertation Defense of Andrzej Wasilczuk Reversing Engineering the Anesthetic State: Insights from Behavior and CNS Circuit Cracking November 7th, 1:30-2:30pm Jordan Medical Education Center, Room 505EW 3400 Civic Center Blvd Philadelphia, PA 19104 A hybrid option […]
ABSTRACT: Algorithm audits are powerful tools for studying black-box systems without direct knowledge of those systems’ inner workings. While they have been effectively deployed to identify harms and biases in algorithmic content, algorithm audits’ narrow focus on technical components stop short of considering users themselves as integral and dynamic parts of the system, to be […]
This is a hybrid event with in-person attendance in Levine 307 and virtual attendance on Zoom. ABSTRACT Soft and continuum robots have immense potential to assist humans with tasks that require navigation and manipulation in unstructured environments. In this talk, I present my group's research on the design, modeling, and control of a variety of […]
In this talk, we explain different roles that symmetries and approximate symmetries can play in machine learning models. We define approximately equivariant graph neural networks and we show a bias-variance tradeoff when selecting the symmetries to enforce. We explain how to see equivariant functions as gradients of invariant functions, and we show how to use […]
The Department of Bioengineering at the University of Pennsylvania and Dr. Arjun Raj are pleased to announce the Doctoral Dissertation Defense of Sam Reffsin. Title: Mapping variable host gene expression states to viral infection Date: November 9, 2023 Time: 2:30pm-4:30pm Location: Smilow 11-146AB The public is welcome to attend.
Intrinsic images are maps of surface properties. A classical problem is to recover an intrinsic image, typically a map of surface lightness, from an image. The topic has mostly dropped from view, likely for three reasons: training data is mostly synthetic; evaluation is somewhat uncertain; and clear applications for the resulting albedo are missing. […]
For safety, AI systems in health undergo thorough evaluations before deployment, validating their predictions against a ground truth that is assumed certain. However, this is actually not the case and the ground truth may be uncertain. Unfortunately, this is largely ignored in standard evaluation of AI models but can have severe consequences such as overestimating […]
This is a hybrid event with in-person attendance in Wu and Chen and virtual attendance on Zoom. ABSTRACT Neural disorders, old age, and traumatic injuries limit the ability of humans to perform activities of daily living. Robotics can be used to characterize and retrain human neuromuscular responses. Columbia University Robotics and Rehabilitation (ROAR) Laboratory designs […]
Upcoming exascale architectures require rethinking of the numerical algorithms used in large-scale PDE-based applications. These architectures favor algorithms, such as high-order finite elements, that expose fine-grain parallelism and maximize the ratio of floating point operations to energy intensive data movement. In this talk we present an overview of MFEM , a scalable library for high-order […]
Abstract Recent advances in digital health technologies are enabling biomedical researchers to reframe health optimization and disease treatment in a patient-specific, personalized manner. This talk will focus on my group’s research in two areas of relevance to digital health: (1) cardiogenic vibration sensing and analytics; and (2) musculoskeletal sensing with joint acoustic emissions and bioimpedance. […]
Magnetic nanoparticles that are responsive to clinically safe magnetic fields offer multi-modal nanomedicine capabilities. To succeed, complexities of physics and engineering must be addressed to match physical and magnetic properties of magnetic nanoparticles with devices used to activate them. This requires thoughtful design and fabrication of both nanoparticles and devices, with appropriate testing in relevant […]
Online bipartite matching is one of the most fundamental problems in the online algorithms literature. Karp, Vazirani, and Vazirani (STOC 1990) gave an elegant algorithm for unweighted bipartite matching that achieves an optimal competitive ratio 1-1/e. Aggarwal et al. (SODA 2011) later generalized their algorithm and analysis to the vertex-weighted case. Little is known, however, […]
*This seminar will be held in-person ONLY in Levine 307. The seminar will NOT be recorded. ABSTRACT The talk aims to present the Czech Technical University in Prague as a polytechnic school with a rich history and a lively present. The main milestones of its development, current faculties and institutes, human and financial resources, study […]
ABSTRACT: Shapley values and similar methods are widely used to explain the importance of features in model predictions. Clarity in the semantics of these feature importances is subtle, but crucial: What do these explanations actually mean? And how are they useful? We illustrate using explanations of predictions in three domains: (a) medical outcomes, (b) image […]
This is a hybrid event with in-person attendance in Levine 307 and virtual attendance on Zoom. ABSTRACT I’ll discuss reinforcement learning in two-player zero-sum games. Historically, this area has lacked algorithms that perform well in large settings with imperfect information. I’ll describe a resolution for making self-play RL performant.
Silicon has been the dominant material for electronic computing for decades and very likely will stay dominant for the foreseeable future. However, it is well-known that Moore’s law that propelled Silicon into this dominant position is long dead. Therefore, a fervent search for (i) new semiconductors that could directly replace silicon or (ii) new architectures […]
Despite considerable advancements in recent years, legged robots still fall short in terms of agility when compared to their animal counterparts. This thesis takes a two pronged approach to creating more agile behaviors by pursuing the intuition that agile legged machines should use much of their available power during agile behaviors. The first approach leverages […]
Molecular heterogeneity is emerging as a critical feature of multicellular life. While single-cell analyses have revealed the existence of cell-to-cell variation in the levels and activities of the molecules responsible for gene regulation, the source of such variation is still poorly understood. The Downing Lab studies how genome replication contributes to epigenetic heterogeneity across stem cell populations. We recently developed a new sequencing method (Repli-Bisulfite Sequencing) that enables analysis of DNA methylation within newly replicated strands of DNA […]
Abstract Remarkable advances in imaging, computation, and technology are rapidly moving us into an era where biomedical knowledge discovery is increasingly limited only by creativity. This has resulted in unprecedented opportunities to improve the diagnosis and treatment of disease. The vision field has been at the forefront of these advances in AI for healthcare because of the easy accessibility […]
This is a hybrid event with in-person attendance in Wu and Chen and virtual attendance on Zoom. ABSTRACT Data-driven machine learning methods are making advances in many long-standing problems in robotics, including grasping, legged locomotion, perception, and more. There are, however, robotics applications for which data-driven methods are less effective, and sometime inappropriate. Data acquisition […]
Stochastic geometry is a branch of probability theory that deals with the study of random spatial patterns. Random point patterns, termed point processes, are the most basic such objects that appear in numerous applications. After presenting a brief introduction to point processes, we will present our work on the stochastic modeling and analysis of wireless […]
This thesis explores advancements in three distinct domains: communications, privacy, and machine learning. Within the realm of communication, a comprehensive study is conducted on channel coding at low capacity, a critical aspect of Internet of Things (IoT) technology requiring reliable transmission over channels with minimal capacity. Despite existing finite-length analyses yielding inaccurate predictions and current […]
Structural design optimization has long played a crucial role in engineering, often with the goal of creating stiff and lightweight structures for aerospace and other applications. However, optimizing structures against failure is also crucial and has been less explored. Failure at interfaces is particularly challenging in design optimization as they involve high local stress concentrations […]
Bioadhesive technologies are important in a wide range of applications, spanning from wound management to wearable technologies. Forming and controlling tough adhesion on biological tissues has been a long-lasting challenge, necessitating transdisciplinary approaches. In my talk, I will share our recent progress in the design, mechanics, and applications of tough bioadhesives. I will first discuss […]
Computer security is traditionally about the protection of technology, whereas trust and safety efforts focus on preventing technology abuse from harming people. In this talk, I'll explore the interplay between security and tech abuse, and make the case that trust and safety represents an important frontier for computer security researchers. To do so, I'll draw […]
ABSTRACT: As deep learning systems improve, their applicability to critical domains is hampered because of a lack of transparency. Post-hoc explanations attempt to address this concern but they provide no guarantee of faithfulness to the model’s computations. Inherently interpretable models are an alternative but such models are often considered to be too simple to perform […]
PSOC@Penn Seminar, Wednesday Nov 29th ** New Location ** DRL 2N3 2N3 conference/seminar room is in DRL 2nd floor towards end of hallway that parallels Walnut St -Noon - 1.00pm : PSOC talk Speaker: Denise Montell, PhD Duggan Professor and Distinguished Professor, Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara https://www.mcdb.ucsb.edu/people/faculty/denise-montell https://denisemontell.mcdb.ucsb.edu/ Talk : “TBA” […]
Abstract: Modeling thrombus growth in pathological flows allows evaluation of risk under patient-specific pharmacological, hematological, and hemodynamical conditions. To this end, we have developed a 3D multiscale framework for the prediction of thrombus growth under flow on a spatially resolved surface presenting collagen and tissue factor (TF). The multiscale framework is composed of four coupled […]
Aluminum Nitride (AlN) is a well-established thin film piezoelectric material. AlN bulk acoustic wave (BAW) radio frequency (RF) filters were one of the key innovations that enabled the 3G and 4G smart phone revolution. Recently, the substitutional doping of scandium (Sc) for aluminum (Al) to form aluminum scandium nitride (AlScN) has been studied to significantly […]
Power electronics is an essential enabler for efficient energy utilization across many different applications as well for renewable electricity generation. Advances in power semiconductor materials and devices are improving power electronics capabilities, but power electronics also relies heavily on passive electromagnetic components---inductors, transformers, and capacitors. The capabilities of these components are increasingly the bottlenecks limiting […]
The Department of Bioengineering at the University of Pennsylvania and Dr. Christopher Fang-Yen are pleased to announce the Doctoral Dissertation Defense of John Zihao Li. Title: A robotic system for automated genetics of Caenorhabditis elegans. Date: Thursday, November 30, 2023 Time: 2:00pm Location: Greenberg Lounge, 114 Skirkanich Hall Zoom Option: https://upenn.zoom.us/j/5692069917?pwd=M2tmSnV5QnZxakx5QVhLd0VDR2YzQT09 Meeting ID: 569 206 9917 Passcode: […]
Abstract: Understanding and controlling polymer-solid interactions is critical for optimizing the catalytic processes involved in polymer upcycling. In this Ph.D. thesis, I explored the intricacies of polymer behavior in nanoporous materials by monitoring the capillary infiltration dynamics of polystyrene (PS) and polyethylene (PE) into random packings of silica nanoparticles. To test the effect of surface […]
Medical devices, healthcare delivery, and other cyber-physical systems depend on sensors to make safety-critical, automated decisions. My research lab investigates the problem of how to protect cyber-physical systems from adversaries who can maliciously control sensor output by subverting its semiconductor physics. Finding principled, systematic solutions is extremely important to give consumers confidence in innovative medical […]
This is a hybrid event with in-person attendance in Wu and Chen and virtual attendance on Zoom. ABSTRACT Task and motion planning has application in robotics, animation, virtual prototyping and training, and even for seemingly unrelated tasks such as evaluating architectural plans or simulating protein motions. Surprisingly, sampling-based methods have proven effective on problems from all […]