arXiv subjects

Qihang Wu

Publications and source records attributed to Qihang Wu.

6 recordsLinked to original sources

arXiv2026

VPR-Evolve: Multi-Agent-Driven Algorithm Evolution for FPGA Place and Route

CAD tools typically apply the same fixed, hand-designed algorithms across circuits with widely different structural and timing characteristics. A common way to specialize these one-size-fits-all flows to a target design is to tune the CAD tool's hyperparameters. However, hyperparameter tuning can only select among behaviors already implemented by the fixed algorithm, limiting the achievable quality of results while requiring many expensive place-and-route evaluations. We present VPR-Evolve, a multi-agent framework that specializes Versatile Place and Route (VPR), the open-source FPGA pack-place-and-route engine in the Verilog-to-Routing (VTR) flow, by evolving its source code for each design. VPR-Evolve uses LLM agents to propose, implement, and evaluate code-level modifications, while a shared memory records prior outcomes and guides subsequent evolution. Every candidate is evaluated through a complete VPR build and run, directly optimizing a composite score measured as a weighted function of critical-path delay (CPD), routed wirelength (WL), and tool runtime (RT). Across five VTR-9 benchmark circuits, VPR-Evolve improves the composite score by up to 2.7% over stock VPR in VTR-9. Relative to stock VPR, it reduces CPD by up to 9.8%, routed WL by up to 18.1%, and tool RT by up to 79.3%. VPR-Evolve reduces CPD by up to 6.0%, routed WL by up to 2.2%, and tool RT by up to 7.8% compared with a hyperparameter-tuning baseline.

cs.AR↗

arXiv2026

Revisiting Hardware Priority Queue Architectures

Priority queues - data structures that serve elements based on priority rather than insertion order - are fundamental in a wide range of applications, including operating systems, graph algorithms, and data compression. Software implementations, typically based on binary heaps with O(log N) complexity, are sufficient for many scenarios; however they can become performance bottlenecks in latency-sensitive domains such as networking and robotics. Hardware-based priority queues exploit parallelism to significantly reduce operation latency, delivering critical performance improvements in latency-sensitive applications. Despite the breadth of prior work on hardware priority queues, two major challenges remain. First, many foundational architectures were proposed and studied years ago, calling into question their relevance given modern hardware advancements. Second, comprehensive comparisons across different architectures are lacking, making it difficult to evaluate trade-offs in performance, resource utilization, and scalability. This paper addresses both gaps by implementing and evaluating several representative hardware priority queue architectures on modern FPGA platforms and providing a quantitative analysis to guide future design choices. All implementations, tests, and analyses are available through our open-source library at https://github.com/realise-lab/hwpq.

cs.AR↗

arXiv2026

CHICO-Agent: An LLM Agent for the Cross-layer Optimization of 2.5D and 3D Chiplet-based Systems

The rapid growth of large language models (LLMs) and AI workloads has pushed monolithic silicon to its reticle and economic limits, accelerating the adoption of 2.5D/3D chiplet systems. However, these systems increase design complexity by requiring co-design across multiple levels of the computing stack, including application, architecture, chip, and package. The resulting design space is highly combinatorial, with trade-offs among latency, energy, area, and cost. To address this challenge, we propose CHICO-Agent, an LLM-driven optimization framework for 2.5D/3D chiplet-based systems. CHICO-Agent maintains a persistent knowledge base to capture parameter-outcome trends and coordinates exploration through an admin-field multi-agent workflow. Compared with a simulated-annealing baseline, CHICO-Agent finds lower-cost configurations and provides an interpretable audit trail for designers.

cs.AR↗

arXiv2026

Ontological Trajectory Forecasting via Finite Semigroup Iteration and Lie Algebra Approximation in Geopolitical Knowledge Graphs

We present EL-DRUIN, an ontological reasoning system for geopolitical intelligence analysis that combines formal ontology, finite semigroup algebra, and Lie algebra approximation to forecast long-run relationship trajectories. Current LLM-based political analysis systems operate as summarisation engines, producing outputs bounded by textual pattern matching. EL-DRUIN departs from this paradigm by modelling geopolitical relationships as states in a finite set of named Dynamic Patterns, composing patterns via a semigroup operation whose structure constants are defined by an explicit composition table, and embedding each pattern as a vector in an 8-dimensional semantic Lie algebra space. Forward simulation iterates this semigroup operation, yielding reachable pattern sets at each discrete timestep; convergence to idempotent absorbing states (fixed points of the composition) constitutes the predicted long-run attractor. Bayesian posterior weights combine ontology-derived confidence priors with a Lie similarity term measuring the cosine similarity between the vector sum of composing patterns and the target pattern vector, providing interpretable, calibrated probabilities that are not self-reported by a language model. Bifurcation points -- steps at which two candidate attractors have near-equal posterior mass -- are detected and exposed to downstream analysis. We demonstrate the framework on six geopolitical scenarios including US-China technology decoupling and the Taiwan Strait military coercion trajectory. The architecture is publicly available as an open-source system with a Streamlit frontend exposing full computation traces, Bayesian posterior breakdowns, and 8D ontological state vectors.

cs.AI↗

arXiv2025

External Reliable Information-enhanced Multimodal Contrastive Learning for Fake News Detection

With the rapid development of the Internet, the information dissemination paradigm has changed and the efficiency has been improved greatly. While this also brings the quick spread of fake news and leads to negative impacts on cyberspace. Currently, the information presentation formats have evolved gradually, with the news formats shifting from texts to multimodal contents. As a result, detecting multimodal fake news has become one of the research hotspots. However, multimodal fake news detection research field still faces two main challenges: the inability to fully and effectively utilize multimodal information for detection, and the low credibility or static nature of the introduced external information, which limits dynamic updates. To bridge the gaps, we propose ERIC-FND, an external reliable information-enhanced multimodal contrastive learning framework for fake news detection. ERIC-FND strengthens the representation of news contents by entity-enriched external information enhancement method. It also enriches the multimodal news information via multimodal semantic interaction method where the multimodal constrative learning is employed to make different modality representations learn from each other. Moreover, an adaptive fusion method is taken to integrate the news representations from different dimensions for the eventual classification. Experiments are done on two commonly used datasets in different languages, X (Twitter) and Weibo. Experiment results demonstrate that our proposed model ERIC-FND outperforms existing state-of-the-art fake news detection methods under the same settings.

cs.CL↗

arXiv2024

Extended GeV $\gamma$-ray emission around the star forming region of the W3 complex

We analyze the GeV $\gamma$-ray emission from the W3 complex using about 14 years of Pass 8 data recorded by the $\it Fermi$ Large Area Telescope (\textit{Fermi}-LAT). We resolve the $\gamma$-ray emissions around W3 into two components: an elliptical Gaussian overlapping with the molecular gas and a point-like source near the cluster W3 Main. The pion-bump feature of SED for the elliptical Gaussian together with the better fitting result of pion decay model favor the hadronic origin. We further argue that the cosmic rays (CRs) could originate from the interactions between cluster winds and the shock produced by the SNR HB3. The point-like source positionally coincident with the star cluster W3 Main indicates it may be directly powered by near clusters, while its fainter $\gamma$-ray emissions below 10 GeV is possibly due to the shelter from dense gas making the low-energy CRs incapable of penetrating the dense materials. Meanwhile, we cannot rule out that the $\gamma$-ray emissions originate from the interaction of accelerated protons in SNR with the ambient gas.

astro-ph.HE↗