Abstract Rust has gained popularity as a safer alternative to C/C++ for low-level programming due to its memory-safety features and minimal runtime overhead. However, the use of the “unsafe” keyword allows developers to bypass safety guarantees, posing memory-safety risks. Bounded Model Checking (BMC) is commonly used to detect memory-safety problems, but it has limitations for large-scale programs, as it can only detect bugs within a bounded number of executions. In this paper, we introduce UnsafeCop that utilizes and enhances BMC for analyzing memory safety in real-world unsafe Rust code. Our methodology incorporates harness design, loop bound inference, and both loop and function stubbing for comprehensive analysis. We optimize verification efficiency through a strategic function verification order, leveraging both types of stubbing. We conducted a case study on TECC (Trusted-Environment-based Cryptographic Computing), a proprietary framework consisting of 30,174 lines of Rust code, including 3,019 lines of unsafe Rust code, developed by Ant Group. Experimental results demonstrate that UnsafeCop effectively detects and verifies dozens of memory safety issues, reducing verification time by 73.71% compared to the traditional non-stubbing approach, highlighting its practical effectiveness.

Accurately localizing 1D signal patterns, such as Gamma-ray well-log depth matching, is crucial in the oilfield service industry as it directly affects the quality of oil and gas exploration. However, traditional methods such as well-log curve analysis and pattern hand-picking matching are labor-intensive and heavily rely on human expertise, leading to inconsistent results. Although attempts have been made to automate this process, challenges such as low computational performance, non-robustness, and non-generalization remain unsolved. To address these challenges, we have developed a data-driven AI system that learns an active signal pattern localization strategy inspired by human attention. Our artificial intelligence system uses an offline reinforcement learning (RL) framework as its central component, which solves a highly abstracted Markov decision process problem via offline training on human-labeled historical data. The RL agent uses top-down reasoning to determine the location of target signal fragments by deforming a bounding window using simple transformation actions. To overcome distribution shifts between logged data and real and ensure generalization, we propose a discrete distributionally robust soft actor-critic RL framework (DRSAC-Discrete) to solve the Markov decision process problem under uncertainty. By exploring unfamiliar environments in a restrictive manner, the DRSAC-Discrete algorithm provides a safe solution that can be used when data is limited during the early stage of this industrial application. We evaluated the reinforcement learning-based localization system on augmented field Gamma-ray well-log datasets, and the results showed promising localization capability. Furthermore, the DRSAC-Discrete algorithm demonstrated relatively robust performance guarantees when facing data shortage.

Full-waveform inversion (FWI) plays a significant role in producing high-resolution subsurface imaging in seismic prospecting and ground penetrating radar (GPR). However, FWI faces various challenges in practice. For example, the lack of low-frequency information due to acquisition limitations will make the FWI prone to falling to the local minimum. In this project, a deep learning-based approach is proposed to extrapolate the low-frequency data. Specifically, we propose a robust progressive learning (RPL) algorithm that combines physics-guided FWI and data-driven deep learning technology. The proposed method is robust against the choice of the initial model. Experimental results show that our method can achieve high efficiency and accuracy by using a limited amount of training data. The subsurface structures are successfully reconstructed with our extrapolated low-frequency data.

The low-frequency seismic data provide crucial information for guiding the full-waveform inversion (FWI), especially when strong reflectors exist in the velocity model. However, hardware limitations make it difficult to acquire low-frequency data. To overcome the nonlinearity and ill-posedness caused by the absence of the low-frequency data, we develop an efficient progressive transfer learning algorithm for low-frequency extrapolation. The proposed method combines the FWI, the sparsity-promoted bandwidth-extension (BWE) algorithm, and the physics-guided data-driven deep learning approach. Compared with pure data-driven learning-based methods and the original progressive transfer learning method without BWE, our proposed algorithm shows better generalization ability. By integrating the physics constraints and the BWE algorithm, the performance of our method is less dependent on the quality of the initial training velocity model and the corresponding training set. We propose a logarithmic transformation to rebalance the loss function to overcome the challenge of predicting the weak reflection low-frequency data. To accelerate the algorithm, we propose a learning-based BWE method for initializing the training set and a truncated FWI method to reduce the iterative workflow’s computational cost. Experimental results show that our method achieves both high efficiency and high accuracy. The subsurface structures below the strong reflectors are successfully reconstructed with our extrapolated low-frequency data.

Video visual relation detection is a meaningful research problem, which aims to build a bridge between dynamic vision and language. In this paper, we propose a novel video visual relation detection method with multi-model feature fusion. First, we detect objects on each frame densely with the state-of-the-art video object detection model, flow-guided feature aggregation (FGFA), and generate object trajectories by linking the temporally independent objects with Seq-NMS and KCF tracker. Next, we break the relation candidates, i.e., co-occurrent object trajectory pairs, into short-term segments and predict relations with spatial-temporal feature and language context feature. Finally, we greedily associate the short-term relation segments into complete relation instances. The experiment results show that our proposed method outperforms other methods by a large margin, which also earned us the first place in visual relation detection task of Video Relation Understanding Challenge (VRU), ACMMM 2019.

Acting as a bridge between vision and language, visual relationship detection (VRD) aims to represent objects and their interactions in an image with several relationship triplets. Nevertheless, the conventional VRD task shows little consideration for the penalization of incorrect relationship predictions, which in turn undermines its support for image understanding applications. In this paper, we propose a novel VRD task named hierarchical visual relationship detection (HVRD), which encourages predictions with abstract yet compatible relationship triplets when the confidence level of the specific image content is relatively low. Meanwhile, HVRD can handle the inevitable ambiguity of groundtruth annotation in VRD. Based on this, we propose a HVRD method, consisting of hierarchical object detection and hierarchical predicate detection. It can effectively detect the hierarchical visual relationships by exploiting both object concept hierarchy and predicate concept hierarchy with order embedding. We also propose the first datasets for HVRD evaluation, H-VRD and H-VG, by expanding the relationship category spaces of VRD and VG datasets to hierarchical ones respectively. The experimental results show that our method is superior to the state-of-the-art baselines.