Rejoining fragment images of precious artifacts is a meaningful task because complete artifacts could provide valuable clues for the research of human civilization. However, existing rejoining methods face several challenges including time-consuming manual annotation, insufficient rejoining accuracy, and prohibitive computation cost. For rejoining fragment images of bone sticks (a precious artifact), we propose a lightweight vision graph neural network called RejoinViG to address these challenges. First, our method avoids time-consuming manual annotation of ballast contour data by experts. Specifically, our method directly takes a pair of fragment images as input and then determines whether the image pair is rejoinable. Second, our method improves rejoining accuracy by contour, script, and texture through dynamically constructing local and global graphs. Third, our method improves rejoining accuracy while reducing computation cost by introducing a new attention mechanism named node self-attention. Extensive experiments demonstrate that our method outperforms the state-of-the-art methods significantly. For example, the Top-1 accuracy of our method is 3.9 times that of SFF-Siam. Surprisingly, our method successfully rejoins a pair of previously unknown but rejoinable fragment images of bone sticks in a real-world scenario.

With the popularity of federated learning, federated domain generalization (FedDG) has attracted more and more attention. Existing works of federated learning indicate that the generalization performance of the global model can be improved when the global model is obtained by aggregating local models according to suitable weights. However, existing methods to calculate weights do not fully utilize the data influences on the global model update, which gives us an opportunity to improve the generalization performance of the global model further. In this paper, we propose the method DI (data influences), which utilizes data influences on the global model update to calculate dynamical weights of local model in each round of training. Specifically, the first component data influence calculator (DIC) of DI calculates local weights of local model from the influences of data on the global model update and we introduce the influence function to complete the calculation process. The second component data influence adjuster (DIA) of DI calculates global weights (which are used in the aggregation process of the global model) from local weights. Extensive experiments indicate that our method improves the generalization performance of models significantly. In particular, our method improves model accuracy on benchmark datasets PACS, OfficeHome, and Office-31 by 1.79%, 1.61%, and 2.39% on average, respectively. Source code is publicly available at github-https://github.com/zikunZHOUHH/Fed-DI.

Skin diseases are one of the most common diseases worldwide, and the mismatch between skin disease patients and dermatologists leads to a huge waste of healthcare resources. Accurately matching skin disease patients to appropriate dermatologists by an image-based method of skin disease recognition can reduce the waste of healthcare resources. However, existing image-based methods of skin disease recognition do not fully utilize multi-source and multi-scale features, which leaves us the chance to improve skin disease recognition further. In this paper, we propose a fusion method of multi-source image features and multi-scale image features to improve skin disease recognition. First, we design a fusion module of multi-source image features to integrate multi-source image information. By dual Convolutional Block Attention Module (CBAM) blocks, the fusion module of multi-source image features enhances the feature representation of key regions and then obtains a comprehensive representation of skin diseases. Second, we propose a fusion module of multi-scale image features. By two parallel backbone networks, the fusion module of multi-scale image features can extract deep feature representations from different scales and exploit their complementarity. To validate the effectiveness of our method, we conduct extensive experiments. The experiment results demonstrate that our method outperforms the state-of-the-art method, achieving improvements of 6.30%, 12.52%, 10.85%, 12.16%, and 5.06% in accuracy, precision, recall, F1-score, and AUC, respectively.

With the popularity of federated learning, federated domain generalization (FedDG) has attracted more and more attentions. Existing works of federated learning indicate that the generalization performance of the global model can be improved when the global model is obtained by aggregating local models according to a suitable weights. However, the existing methods to calculate weights do not fully utilize the data influences on the global model update, which gives us an opportunity to improve the generalization performance of the global model further. In this paper, we propose the method DI (data influences), which utilizes the data influences on the global model update to calculate dynamical weights of local model in each round of training. Specifically, the first component data influences calculator (DIC) of DI calculates the local weights of local model from the influences of each data on the global model update and we introduce the influences function to complete the calculation process. The second component data influences adjuster (DIA) of DI calculates the global weights (which are used in the aggregation process of the global model) from local weights. Extensive experiments indicate that our method improves the generalization performance of models significantly. In particular, our method improves model accuracy on benchmark datasets PACS, OfficeHome, and Office-31 by 1.79%, 1.61%, and 2.39% on average, respectively. Source code is publicly available at github.

The capability of GenAI-based chatbots, such as ChatGPT and Gemini, has expanded quickly in recent years, turning them into GenAI Chatbot Ecosystems. Yet, users’ understanding of how such ecosystems work remains unknown. In this paper, we investigate users’ mental models of how GenAI Chatbot Ecosystems work. This is an important question because users’ mental models guide their behaviors, including making decisions that impact their privacy. Through 21 semi-structured interviews, we uncovered users’ four mental models towards first-party (e.g., Google Gemini) and third-party (e.g., ChatGPT) GenAI Chatbot Ecosystems. These mental models centered around the role of the chatbot in the entire ecosystem.We further found that participants held a more consistent and simpler mental model towards third-party ecosystems than the first-party ones, resulting in higher trust and fewer concerns towards the thirdparty ecosystems. We discuss the design and policy implications based on our results.

DRAM failures are one of the major hardware threats to the reliability of large-scale data centers since the uncorrectable errors in DRAMs may cause servers to shut down. Existing works try to solve this problem by predicting DRAM failures in advance with Machine Learning models. In these works, correctable errors (CEs) are generally deemed as the most important feature. The major reason behind CEs' emergence is the accumulated stress caused by intensive workloads. Moreover, defective DRAMs will not manifest themselves as system errors until the defective cells are accessed by some specific workloads. Therefore, the running workloads on a server are also important for DRAM failure prediction. In this paper, we focus on the impact of workloads on DRAM failures. We design the workload features from both macroscopical and microscopical aspects, i.e. node-level performance metrics and cell-level DRAM access pattern, respectively. Furthermore, we propose Hierarchical DRAM Error Code (HiDEC) to represent the DRAM access pattern. We leverage several Decision Tree-based models for DRAM failure prediction to highlight the generality of our designed features. Experiments are carried out based on the dataset collected from a real-world commercial data center. The results show that both macroscopic and microscopic features can bring significant improvements to the prediction performance.

This paper develops a novel maximum power point tracking (MPPT) control strategy for nonlinear photovoltaic (PV) systems. The MPPT control problem of the considered PV systems is first formulated in the framework of fuzzy descriptor systems. Then, based on the new formulation, a fuzzy sliding mode control (FSMC) law is constructed to drive the state trajectories into a desired sliding surface within the finite-time T* with T* <; T. Moreover, sufficient conditions are derived to ensure the reachable set boundings of the closed-loop PV control systems in the finite-time intervals [0,T*] and [T*,T]. A simulation example is given to show the effectiveness of the proposed design method.

Intermittent faults are a critical reliability threat in deep submicron VLSI circuits. These faults occur non-deterministically due to unstable hardware and unpredictable operating conditions; they are activated/deactivated with changes in the runtime environment. Online fault prediction models are commonly used to predict soft errors and aging effects. A small set of flip-flops, whose states constitute the signature, conveys information about the fine-grained behavior of the circuit, and serves as the input to a machine-learning (ML) model. The nondeterministic failure mechanisms of intermittent faults, however, result in temporally- and spatially-correlated signatures (TSC-signatures). Moreover, the high-dimensional time-series features impede the use of traditional ML models for intermittent-fault detection. To cope with this challenge, we adapt the TSC-signatures to existing ML detection models. Moreover, we propose a novel detection model based on Recurrent Neural Network with Long Short-Term Memory (LSTM) that is inherently suitable for this problem. Simulation results for the ITC99 benchmark circuits highlight the effectiveness of the proposed model.

This study focuses on estimation and compensation on the unknown measurement noises of large-scale systems subject to nonlinear dynamics and interconnections. Interval type-2 T-S fuzzy model is used to describe each nonlinear subsystem. For the sake of attenuating adverse impacts from the unknown measurement noises, a combined method of reachable set bounding and estimation-compensation control is proposed. First, we introduce an augmented fuzzy observer that fulfills a simultaneous estimation for the system states and unknown measurement noises, which guarantees that the estimation error is bounded within the ellipsoidal boundary. Then, a fuzzy compensation controller is used to attenuate the impacts from the unknown measurement noises. Finally, simulation results show the effectiveness of our method against the unknown measurement noises.