Tue 18 Feb 16:00: The S Algebra in Self-Dual Yang-Mills: Twistorial and Spacetime Perspectives
Abstract not available
- Speaker: Adam Kmec (Oxford)
- Tuesday 18 February 2025, 16:00-17:00
- Venue: CMS, MR11.
- Series: Mathematical Physics Seminar; organiser: Professor Maciej Dunajski.
Tue 11 Feb 16:00: Spacetime extensions in low regularity
Abstract not available
- Speaker: Peter Cameron (Imperial)
- Tuesday 11 February 2025, 16:00-17:00
- Venue: CMS, MR11.
- Series: Mathematical Physics Seminar; organiser: Professor Maciej Dunajski.
Tue 04 Mar 16:00: TBA
Abstract not available
- Speaker: Nick Manton (DAMTP)
- Tuesday 04 March 2025, 16:00-17:00
- Venue: CMS, MR11.
- Series: Mathematical Physics Seminar; organiser: Professor Maciej Dunajski.
Tue 25 Feb 16:00: On kink clusters for scalar fields in dimension 1+1.
Abstract not available
- Speaker: Jacek Jendrej (Sorbonne)
- Tuesday 25 February 2025, 16:00-17:00
- Venue: CMS, MR11.
- Series: Mathematical Physics Seminar; organiser: Professor Maciej Dunajski.
Tue 18 Feb 16:00: The S Algebra in Self-Dual Yang-Mills: Twistorial and Spacetime Perspectives
Abstract not available
- Speaker: Adam Kmec (Oxford).
- Tuesday 18 February 2025, 16:00-17:00
- Venue: CMS, MR11.
- Series: Mathematical Physics Seminar; organiser: Professor Maciej Dunajski.
Tue 18 Feb 16:00: The S Algebra in Self-Dual Yang-Mills: Twistorial and Spacetime Perspectives
Abstract not available
- Speaker: Adam Kmec (Oxford).
- Tuesday 18 February 2025, 16:00-17:00
- Venue: CMS, MR11.
- Series: Mathematical Physics Seminar; organiser: Professor Maciej Dunajski.
Tue 11 Feb 16:00: Spacetime extensions in low regularity
Abstract not available
- Speaker: Peter Cameron (Imperial).
- Tuesday 11 February 2025, 16:00-17:00
- Venue: CMS, MR11.
- Series: Mathematical Physics Seminar; organiser: Professor Maciej Dunajski.
Tue 11 Feb 16:00: Spacetime extensions in low regularity
Abstract not available
- Speaker: Peter Cameron (Imperial).
- Tuesday 11 February 2025, 16:00-17:00
- Venue: CMS, MR11.
- Series: Mathematical Physics Seminar; organiser: Professor Maciej Dunajski.
Tue 04 Feb 13:00: Text-and-audio methods
This talk supports the R255 Advanced Topics in Machine Learning module on Multimodal Learning and provides a bird’s eye view of the rapidly evolving text-audio landscape, with a focus on music as a primary example of audio data. I will first present types of tasks that exist in this space, then discuss data curation challenges and follow with an overview of some existing retrieval and generation methods, including a quick primer on diffusion models. Finally, I will describe current evaluation metrics and their limitations.
- Speaker: Cătălina Cangea, ex-Google DeepMind
- Tuesday 04 February 2025, 13:00-14:00
- Venue: Lecture Theatre 2, Computer Laboratory, William Gates Building.
- Series: Artificial Intelligence Research Group Talks (Computer Laboratory); organiser: Mateja Jamnik.
Tue 28 Jan 13:00: SynFlowNet: Design of Synthesisable Molecules with GFlowNets
Generative models see increasing use in computer-aided drug design. However, while performing well at capturing distributions of molecular motifs, they often produce synthetically inaccessible molecules. To address this, we introduce SynFlowNet, a GFlowNet model whose action space uses chemical reactions and buyable reactants to sequentially build new molecules. By incorporating forward synthesis as an explicit constraint of the generative mechanism, we aim at bridging the gap between in silico molecular generation and real world synthesis capabilities. We evaluate our approach using synthetic accessibility scores and an independent retrosynthesis tool to assess the synthesizability of our compounds, and motivate the choice of GFlowNets through considerable improvement in sample diversity compared to baselines. Additionally, we identify challenges with reaction encodings that can complicate traversal of the MDP in the backward direction. To address this, we introduce various strategies for learning the GFlowNet backward policy and thus demonstrate how additional constraints can be integrated into the GFlowNet MDP framework.
- Speaker: Miruna Cretu (University of Cambridge)
- Tuesday 28 January 2025, 13:00-14:00
- Venue: Lecture Theatre 2, Computer Laboratory, William Gates Building.
- Series: Artificial Intelligence Research Group Talks (Computer Laboratory); organiser: Mateja Jamnik.
Wed 05 Feb 14:00: Generalization and Informativeness of Conformal Prediction
A popular technique for uncertainty quantification is conformal prediction, which converts point predictions into set predictions that are guaranteed to contain the true label of a test input with a user-defined probability. However, the size of the predicted set—-and thus the informativeness of the prediction—-is not controlled. In this talk, we present a theoretical connection between the informativeness of conformal prediction sets and generalization properties of the underlying model. Furthermore, we extend this analysis to conformal risk control and covariate shifts. The results provide insight into the effect of task-specific quantities and algorithmic hyperparameters, which we also illustrate via experiments.
- Speaker: Dr Fredrik Hellstrom, UCL
- Wednesday 05 February 2025, 14:00-15:00
- Venue: MR5, CMS Pavilion A.
- Series: Information Theory Seminar; organiser: Prof. Ramji Venkataramanan.
Tue 18 Mar 14:00: Title to be confirmed
Abstract not available
- Speaker: Alice Hutchings (University of Cambridge)
- Tuesday 18 March 2025, 14:00-15:00
- Venue: Webinar & LT2, Computer Laboratory, William Gates Building..
- Series: Computer Laboratory Security Seminar; organiser: Anna Talas.
Fri 14 Feb 16:00: Do we really need more data?
Engineers love to measure stuff. Knowing the correct answer is a simple joy. But ultimately what matters is not the data but what we can do with it.
Uncertainties exist in all Engineering systems and decisions such as design, control, and maintenance need to be made accounting for the statistics of the system.
By gathering data through measurement we can reduce these uncertainties and improve our decision making ability. But gathering data is often costly.
So is gathering more data about our system actually worth the cost? How strong is our existing statistical understanding of the system we’re studying? Is it good enough for the decisions we need to make? Do we have enough data already?
This talk will explore a method for quantifying whether data collection is worthwhile for supporting decision making (called Value of Information analysis), and what it can tell us about how we should use data to support the design of energy systems.
- Speaker: Max Langtry, PhD student, CUED
- Friday 14 February 2025, 16:00-17:00
- Venue: JDB Seminar Room, CUED.
- Series: Engineering - Dynamics and Vibration Tea Time Talks; organiser: div-c.
Fri 31 Jan 14:00: Police responses to young people’s experiences of cyberstalking
In our digitally interconnected world, cyberstalking has become a significant concern for online users worldwide. Young people have embraced new technologies for communication, making social media apps such as Facebook, X, Instagram, Snapchat and other platforms an integral part of their lives for communicating with each other. Young people utilise digital spaces to create new connections and even initiate, sustain, and carry out part of their intimate relationships online. Consequently, technology has provided opportunities to facilitate online monitoring of others due to the proficiency and ease with which information can be obtained.
The rise of digital technologies has given perpetrators new avenues and opportunities to target victims resulting in a rise of cyberstalking. However, little work to date has explored young people’s perceptions and experiences of cyberstalking. With research consistently revealing very few cyberstalking victims choose to report their experiences to the police. There is notable research gap regarding young people’s reasons not to report cyberstalking incidents.
Guided by the power differentials between police officers and young people. This research examines police officers use of authority to regulate and influence behaviour of young people. This paper will explore some of the key issues identified in the literature review, including prevalence and variations of cyberstalking among young people, experiences and barriers to reporting to the police and other agencies. It draws on insights from interviews with young cyberstalking victims and frontline response police officers. Preliminary findings from the voices of young people indicate age bias among police officers, resulting in misguided advise on cyberstalking incidents, leading to escalated risk and lack of support. The perspectives and experiences of young people emphasise the importance of lasting changes in attitudes, policies and practices. By tackling these, the research aims to contribute to improved victims support, inform policy and refine practices within the cyberstalking sector.
- Speaker: Tahreem Tahir, University of Central Lancashire
- Friday 31 January 2025, 14:00-15:00
- Venue: Webinar & FW11, Computer Laboratory, William Gates Building..
- Series: Computer Laboratory Security Seminar; organiser: Tina Marjanov.
Mon 10 Mar 13:00: Ice Shelves: Antarctica’s Gatekeepers
Abstract not available
- Speaker: Becky Dell (Geography)
- Monday 10 March 2025, 13:00-14:00
- Venue: MR3, CMS.
- Series: Quantitative Climate and Environmental Science Seminars; organiser: Dr Kasia Warburton.
Mon 27 Jan 14:00: The Demikernel Datapath Architecture for Microsecond-scale Datacenter Systems
Datacenter systems and I/O devices now run at single-digit microsecond latencies, requiring nanosecond-scale operating systems. Traditional kernel-based operating systems impose an unaffordable overhead, so recent kernel-bypass OSes (e.g., Arrakis, Ix) and libraries (e.g., Caladan, eRPC) eliminate the OS kernel from the I/O datapath. However, these systems do not offer a general-purpose datapath OS replacement that meet the needs of microsecond-scale systems. As a result, while kernel-bypass hardware is widely available in the datacenter, it is not widely used.
This talk summarizes Demikernel, a flexible datapath OS and architecture designed for heterogenous kernel-bypass devices and microsecond-scale datacenter systems. Demikernel supports a variety of kernel-bypass hardware, including DPDK , RDMA, as well as software bypass solutions like io_uring. To support microsecond-scale operation, Demikernel includes a new nanosecond-scale TCP stack, written in Rust and proposes new memory management, CPU scheduling and network abstractions. Demikernel is currently used by Bing and will go into production with Azure services later this year.
Bio: Irene Zhang is a Principal Researcher at Microsoft Research. Her work focuses on datacenter operating systems and distributed systems, especially making new datacenter hardware technologies more widely usable by highly-demanding datacenter applications. Irene completed her PhD in 2017 at the University of Washington, where her PhD thesis focused on distributed systems that span mobile devices and cloud servers. Her thesis work received the ACM SIGOPS Dennis Ritchie doctoral dissertation award and the UW Allen School William Chan Memorial dissertation award. Before her PhD, Irene was a member of the virtual machine monitor group at VMware, where she worked on memory resource management and virtual machine checkpointing.
- Speaker: Irene Zhang, Principal Researcher, Microsoft Research
- Monday 27 January 2025, 14:00-15:00
- Venue: Computer Lab, FW11.
- Series: Computer Laboratory Systems Research Group Seminar; organiser: Richard Mortier.
Tue 25 Feb 14:00: Zero-Knowledge in Streaming Interactive Proofs
In a recent work, Cormode, Dall’Agnol, Gur and Hickey (CCC, 2024) introduced the model of Zero-Knowledge Streaming Interactive Proofs (zkSIPs). Loosely speaking, such proof-systems enable a prover to convince a streaming verifier that the input x, to which it has read-once streaming access, satisfies some property, in such a way that nothing beyond the correctness of the claim is revealed. Cormode et al. also gave constructions of zkSIPs to some specific and notable problems of interest. In this work, we advance the study of zero-knowledge proofs in the streaming model, by presenting protocols that are significantly more general and more secure. We use a definition of zero-knowledge that is a variation of that used by Cormode et al., which we find more appealing but is technically incomparable. Our main result is a zkSIP for any NP relation, that can be decided by low-depth polynomial-size circuits. We emphasize that this is the first general purpose protocol in this model, which captures, as a special case, the problems considered by the prior work. We also construct a specialized protocol for the ``polynomial evaluation’’ problem considered in that work, with improved parameters. The protocols constructed by Cormode et al. have an inverse polylogarithmic simulation error (i.e., a gap with which a bounded-space distingiusher can distinguish the simulation from a real execution). This means that their protocols are entirely insecure if run multiple times (say on different inputs). In contrast, our protocols achieve a negligible zero-knowledge error, a stronger and far more robust security guarantee.
- Speaker: Tomer Gewirtzman (Technion)
- Tuesday 25 February 2025, 14:00-15:00
- Venue: Computer Laboratory, William Gates Building, Room SS03.
- Series: Algorithms and Complexity Seminar; organiser: Tom Gur.
Fri 16 May 15:00: tbc
Abstract not available
- Speaker: Professor Anna Wredenberg, Karolinska Institute, Finland
- Friday 16 May 2025, 15:00-16:00
- Venue: MRC MBU, Level 7 Lecture Theatre, The Keith Peters Building, CB2 0XY.
- Series: MRC Mitochondrial Biology Unit Seminars; organiser: Lisa Arnold.
Fri 14 Feb 14:00: Theoretical and Experimental Studies on Deformation and Fracture of Metallic Glasses.
Metallic glasses possess outstanding mechanical properties, including high yield strength, large elastic limits, and excellent fracture toughness, positioning them as promising materials for applications in load-bearing structures, sports equipment, and beyond. However, their brittle fracture behavior, characterized by localized shear band instability, remains a critical challenge. The lack of crystalline structures and well-defined defects in metallic glasses complicates the understanding of the underlying mechanisms responsible for such behavior. This talk presents a comprehensive investigation into the deformation mechanisms of metallic glasses. A thermodynamically consistent continuum model is developed to capture viscoplastic deformation and the evolution of spatial heterogeneity. The model, which correlates local viscoplastic strain rates with the atomic flux gradient tensor, is implemented in the open-source finite element platform FEniCS. It successfully reproduces key deformation phenomena, including shear band localization, creep, and cavitation under diverse loading conditions. Additionally, laser shock experiments were performed to examine the fracture behavior of metallic glasses under ultrahigh strain rates (>10⁷ s⁻¹). Cu₅₀Zr₅₀ metallic glass ribbons demonstrated near-ideal fracture strengths, surpassing those of crystalline metals under similar conditions. The talk will also discuss void growth kinetics during tension, shedding light on the fracture processes of metallic glasses at extreme strain rates.
- Speaker: Dr Wenqing Zhu, CUED
- Friday 14 February 2025, 14:00-14:30
- Venue: Oatley 1 Meeting Room, Department of Engineering.
- Series: Engineering - Mechanics and Materials Seminar Series; organiser: div-c.
Wed 12 Mar 16:00: Title to be confirmed
Abstract not available
- Speaker: Jonny Evans (Lancaster)
- Wednesday 12 March 2025, 16:00-17:00
- Venue: MR13.
- Series: Differential Geometry and Topology Seminar; organiser: Ailsa Keating.