This paper addresses the design problem of observer-structured controller, which has been recently proposed as an extension of Luenberger observer-based controllers to the case of controlling Linear Parameter-Varying (LPV) systems, and demonstrates its effectiveness in three practical design examples. The first one is model-based visual feedback controller design for a cart-driven inverted pendulum, the second one is data-based flight controller design, and the last one is model-data-concurrent-based flight controller design. Observer-structured controller has been proposed to embed plant state estimation ability to a priori designed Linear-Time-Invariant (LTI) or LPV controllers, similarly to existing methods in literature to embed plant state estimation ability to a priori designed LTI controllers which are designed for controlling LTI plant systems. However, the demonstrations of its applicability and usefulness have not been sufficiently illustrated. This paper therefore shows them directly by designing observer-structured controllers for model-based design problem, in which only mathematical plant models and a priori designed controller state-space matrices are available, for data-based design problem, in which only operational data and a priori designed controller state space matrices are available, and for model-data-concurrent-based design problem, in which operational data as well as mathematical plant models and a priori designed controller state-space matrices are available. In particular, the controller designed in the first formulation demonstrates the practical state estimation performance by lab-level experiments, and the controller in the second formulation demonstrates the usefulness of operational data to improve plant state estimation ability but simultaneously illustrates the lack of theoretical performance guarantee, and the controller in the last formulation well demonstrates the effectiveness of operational data to improve plant state estimation performance while rigorous estimation performance is guaranteed by using models.
Wafer acceptance testing (WAT) is a process that is used to assess the quality and reliability of manufactured wafers. This technique for the early detection and screening of chips allows for improvements in their reliability and performance during the manufacture of semiconductor devices. The automatic test equipment (ATE) used for processing millions of wafers is susceptible to a number of issues, including the absence of data values, the presence of redundant parameters, and categorical imbalance. These issues increase the cost of data processing, and impede an investigation into the relationship between WAT and feature diagnostics. In this study, we propose a method with a low test escape rate based on a multi-objective optimization algorithm to reduce the cost of testing and minimize the number of defective dice that go undetected. The proposed method retains outliers, dynamically selects the range of the neighborhood to reduce the cost of testing, and uses Shapley values to analyze a WAT dataset to determine the importance of features of the data. The multi-objective optimization algorithm ranks features by their importance, and applies an adaptive method to eliminate features with a low overall correlation, thereby reducing the risk that defective dice are undetected.
Deep learning methods have been extensively applied in brain-computer interface (BCI) systems based on motor imagery (MI) for decoding electroencephalogram (EEG) signals. However, most existing hybrid architectures often struggle to effectively eliminate redundant noise in multi-channel signals and lack adaptability to the inherent non-stationarity and distribution drift of EEG signals. This work proposes a novel end-to-end hybrid attention Transformer network (HATNet) for EEG classification. HATNet first employs a convolutional neural network to extract local spatio-temporal features. To overcome the limitations of existing models, it fuses a Collaborative Attention Mechanism for Lightweight Channels, which dynamically recalibrates feature channels through multidimensional pooling strategies, including entropy pooling, to achieve precise spatial noise suppression. Addressing the non-stationary nature of EEG signals, an innovative Dynamic Hyperbolic Tangent module drives the Transformer encoding layer, adapting in real-time to data distribution drifts and significantly enhancing the model's ability to capture individual variations. Furthermore, cross-layer residual fusion pathways deeply integrate global contextual features with raw local spatio-temporal features. To ensure clear scope definition, experiments explicitly distinguish between primary MI tasks and auxiliary motor execution (ME) tasks. HATNet's performance was evaluated on three primary MI benchmark datasets, namely BCIC-IV-2a, BCIC-IV-2b, and the large-scale OpenBMI, as well as one auxiliary ME dataset, HGD. Experimental results demonstrate that HATNet achieves state-of-the-art performance across all analyses. In subject-dependent evaluations, average accuracy rates reached 81.25%, 86.65%, and 69.57% on the three primary MI datasets respectively, and 96.20% on the auxiliary ME dataset. Furthermore, in subject-independent evaluations, it achieved 60.88%, 80.79%, and 76.28% on the MI datasets respectively, alongside 73.95% on the ME dataset. Through multidimensional feature selection and dynamic adaptive modeling, HATNet exhibits superiority and robustness in enhancing both MI and ME decoding performance.
Consider that there are $k\le n$ agents in a simple, connected, and undirected graph $G=(V,E)$ with $n$ nodes and $m$ edges. The goal of the dispersion problem is to move these $k$ agents to mutually distinct nodes. Agents can communicate only when they are at the same node, and no other communication means, such as whiteboards, are available. We assume that the agents operate synchronously. We consider two scenarios: when all agents are initially located at a single node (rooted setting) and when they are initially distributed over one or more nodes (general setting). Kshemkalyani and Sharma presented a dispersion algorithm for the general setting, which uses $O(m_k)$ time and $\log(k + \Delta)$ bits of memory per agent [OPODIS 2021], where $m_k$ is the maximum number of edges in any induced subgraph of $G$ with $k$ nodes, and $\Delta$ is the maximum degree of $G$. This algorithm is currently the fastest in the literature, as no $o(m_k)$-time algorithm has been discovered, even for the rooted setting. In this paper, we present significantly faster algorithms for both the rooted and the general settings. First, we present an algorithm for the rooted setting that solves the dispersion problem in $O(k\log \min(k,\Delta))=O(k\log k)$ time using $O(\log (k+\Delta))$ bits of memory per agent. Next, we propose an algorithm for the general setting that achieves dispersion in $O(k \log k \cdot \log \min(k,\Delta))=O(k \log^2 k)$ time using $O(\log (k+\Delta))$ bits. Finally, for the rooted setting, we give a time-optimal (i.e.,~$O(k)$-time) algorithm with $O(\Delta+\log k)$ bits of space per agent. All algorithms presented in this paper work only in the synchronous setting, while several algorithms in the literature, including the one given by Kshemkalyani and Sharma at OPODIS 2021, work in the asynchronous setting.
