VLDB 2026 Research / reviewers in the wild / expert
Joshua Fixelle
dblp:322/4210
· DBLP profile ↗
4ranked-venue papers
1as first author
4since 2021 · last 2025
0000-0002-1737-0425ORCID · corroborated
Domains — the database's venue-derived domains; a paper can count in several
Software engineering, systems software and programming languages · 2 · 2 since 2021Artificial intelligence and machine learning · 1 · 1 first-author · 1 since 2021Systems, architecture and hardware · 1 · 1 since 2021Graphics, computer vision, multimedia, augmented reality and games · 1 · 1 first-author · 1 since 2021
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2025 | Hypergraph Vision Transformers: Images are More than Nodes, More than EdgesabstractRecent advancements in computer vision have highlighted the scalability of Vision Transformers (ViTs) across various tasks, yet challenges remain in balancing adaptability, computational efficiency, and the ability to model higher-order relationships. Vision Graph Neural Networks (ViGs) offer an alternative by leveraging graph-based methodologies but are hindered by the computational bottlenecks of clustering algorithms used for edge generation. To address these issues, we propose the Hypergraph Vision Transformer (HgVT), which incorporates a hierarchical bipartite hypergraph structure into the vision transformer framework to capture higher-order semantic relationships while maintaining computational efficiency. HgVT leverages population and diversity regularization for dynamic hypergraph construction without clustering, and expert edge pooling to enhance semantic extraction and facilitate graph-based image retrieval. Empirical results demonstrate that HgVT achieves strong performance on image classification and retrieval, positioning it as an efficient framework for semantic-based vision tasks. Joshua Fixelle |
CVPR | 1 |
| 2023 | FreezeTime: Towards System Emulation through Architectural VirtualizationabstractHigh-end FPGAs enable architecture modeling through emulation with high speed and fidelity. However, the available reconfigurable logic and memory resources limit the size, complexity, and speed of the emulated target designs. The challenge is to map and model large and fast memory hierarchies, such as large caches and mixed main memory, various heterogeneous computation instances, such as CPUs, GPUs, AI/ML processing units and accelerator cores, and communication infrastructure, such as buses and networks. In addition to the spatial dimension, this work uses the temporal dimension, implemented with architectural multiplexing coupled with block-level synchronization, to model a complete system-on-chip architecture. Our approach presents mechanisms to abstract instance plurality while preserving timing in sync. With only a subset of the architecture on the FPGA, we freeze a whole emulated module's activity and state during the additional time intervals necessary for the action on the virtualized modules to elapse. We demonstrate this technique by emulating a hypothetical system consisting of a processor and an SRAM memory too large to map on the FPGA. For this, we modify a LiteX-generated SoC consisting of a VexRISC-V processor and DDR memory, with the memory controller issuing stall signals that freeze the processor, effectively ''hiding'' the memory latency. For Linux boot, we measure significant emulation vs. simulation speedup while matching RTL simulation accuracy. The work is open-sourced. Sergiu Mosanu, Joshua Fixelle, Kevin Skadron, Mircea R. Stan |
FPGA | 2 |
| 2023 | ISVABI: In-Storage Video Analytics Engine with Block InterfaceabstractThe wide use of cameras in the past decade has increased the need to process video data significantly. Due to the large volume of video data, analyzing videos to extract useful information has become a critical challenge. Several prior works have tried to accelerate video analytics workloads by offloading some operations to embedded processors within storage devices. Joshua Fixelle, Pingyi Huo, Mircea R. Stan, Michael P. Mesnier, Narayanan Vijaykrishnan |
LCTES | 2 |
| 2022 | ISKEVA: in-SSD key-value database engine for video analytics applicationsabstractKey-value databases are widely used to store the features or metadata generated from the neural network based video processing platforms. Due to the large volumes of video data, these databases use solid state drives (SSDs) as the primary data storage platform, and user query-based filtering, and retrieval operations on data incur large volume of data movement between the SSD and the host processor. In this paper, we present an in-SSD key-value database which uses the embedded CPU core, and DRAM memory on the SSD to support various queries with predicates and reduce the data movement between SSD and host processor significantly. We augment the SSD flash translation layer with key-value database functions and auxiliary data structures to support the user queries using the embedded core and DRAM memory on SSD. The proposed key-value store prototype on the Cosmos plus OpenSSD board reduces data movement between host processor and SSD by 14.57x, achieves an application-level speedup by 1.16x, and reduced energy consumption by 56% across different types of user queries. Joshua Fixelle, Nagadastagiri Challapalle, Pingyi Huo, Zhaoyan Shen, Zili Shao, Mircea R. Stan, Narayanan Vijaykrishnan |
LCTES | 2 |