Given a set of points, clustering consists of finding a partition of a point set into k clusters such that the center to which a point is assigned is as close as possible. Most commonly, centers are points themselves,...
Given a set of points, clustering consists of finding a partition of a point set into k clusters such that the center to which a point is assigned is as close as possible. Most commonly, centers are points themselves, which leads to the famous k-median and k-means objectives. One may also choose centers to be j dimensional subspaces, which gives rise to subspace clustering. In this paper, we consider learning bounds for these problems. That is, given a set of n samples P drawn independently from some unknown, but fixed distribution Ɗ, how quickly does a solution computed on P converge to the optimal clustering of Ɗ? We give several near optimal results. In particular,1. For center-based objectives, we show a convergence rate of Õ(√k/n). This matches the known optimal bounds of [Fefferman, Mitter, and Narayanan, Journal of the Mathematical Society 2016] and [Bartlett, Linder, and Lugosi, IEEE Trans. Inf. Theory 1998] for k-means and extends it to other important objectives such as k-median.2. For subspace clustering with j -dimensional subspaces, we show a convergence rate of Õ(√kj2/n). These are the first provable bounds for most of these problems. For the specific case of projective clustering, which generalizes k-means, we show a convergence rate of Ω(√kj/n) is necessary, thereby proving that the bounds from [Fefferman, Mitter, and Narayanan, Journal of the Mathematical Society 2016] are essentially optimal.
The maximum absolute correlation between regressors, which is called mutual coherence, plays an essential role in sparse estimation. A regressor matrix whose columns are highly correlated may result from optimal input...
详细信息
In the past three years, global COVID-19 pandemic not only impacted people’s physical health but also significantly affected their mental health, which resulting in rapid increase of psychological problems. Emotions ...
In the past three years, global COVID-19 pandemic not only impacted people’s physical health but also significantly affected their mental health, which resulting in rapid increase of psychological problems. Emotions are a common manifestation of psychological changes, and some services (such as music, video, or psychological counseling services) can help users to adjust their emotions in a timely manner, thus to avoid bringing extreme events (e.g., running away from home or committing suicide). Therefore, how to perceive users’ real-time emotions and then recommend the most appropriate services to users has become a challenge. To address this issue, this work proposes an approach for proactive services recommendation driven-by multimodal emotion recognition (named as PSRMER). Specifically, PSRMER first actively identifies a user’s emotion with a multimodal emotion recognition model based on BiGRU and Transformer; Then, considering the user’s emotion and preferences, PSRMER selects the optimal services based on an index-graph linking different emotions and various services; Finally, PSRMER proactively recommends the selected optimal service to the user. Extensive experiments have been conducted and the effectiveness of our proposed method have been proved. Moreover, the proposed method can also be used in smart education, smart transportation, smart elderly care and other modern industry fields.
Given a set of points, clustering consists of finding a partition of a point set into k clusters such that the center to which a point is assigned is as close as possible. Most commonly, centers are points themselves,...
详细信息
Although the relationship between anesthesia and consciousness has been investigated for decades, our understanding of the underlying neural mechanisms of anesthesia and consciousness remains rudimentary, which limits...
详细信息
Although the relationship between anesthesia and consciousness has been investigated for decades, our understanding of the underlying neural mechanisms of anesthesia and consciousness remains rudimentary, which limits the development of systems for anesthesia monitoring and consciousness evaluation. Moreover, the current practices for anesthesia monitoring are mainly based on methods that do not provide adequate information and may present obstacles to the precise application of anesthesia. Most recently, there has been a growing trend to utilize brain network analysis to reveal the mechanisms of anesthesia, with the aim of providing novel insights to promote practical application. This review summarizes recent research on brain network studies of anesthesia, and compares the underlying neural mechanisms of consciousness and anesthesia along with the neural signs and measures of the distinct aspects of neural activity. Using the theory of cortical fragmentation as a starting point, we introduce important methods and research involving connectivity and network analysis. We demonstrate that whole-brain multimodal network data can provide important supplementary clinical information. More importantly, this review posits that brain network methods, if simplified, will likely play an important role in improving the current clinical anesthesia monitoring systems.
Leveraging a number of inner capacitors/inductors, hybrid-clamped multilevel converters (MLCs) normally face great challenges among good performance (proper charge/discharge of these devices), high efficiency (maintai...
Leveraging a number of inner capacitors/inductors, hybrid-clamped multilevel converters (MLCs) normally face great challenges among good performance (proper charge/discharge of these devices), high efficiency (maintaining low losses) and high power density (compact profile). On the other hand, these multiple-device energy-processing requirements have been addressed well in some promising multi-port converters (MPCs), and, therefore, inspire us to implement well-developed compact MPCs to facilitate the voltage/current level generation process in hybrid-clamped MLCs. Though recently, some researchers started to integrate active cells into hybrid-clamped MLCs and improve capacitor voltage control and generate extra output levels, the systematic synthesis method is still unclear and rarely discussed in the literature. To address this gap, we propose a systematic synthesis method for those hybrid clamped MLCs that can benefit from embedding well-developed MPCs. The approach can be applied for both voltage-source and current-source hybrid-clamped MLCs, covering emerging MLCs. In particular, we also derived and verified a new mixed hybrid MLC family through an emerging current-fed dual-input isolated multi-port converter. This topology features both current-source and voltage-source benefits and is ideal for future renewable generation integration.
This paper studies the formation of final opinions for the Friedkin-Johnsen (FJ) model with a community of partially stubborn agents. The underlying network of the FJ model is symmetric and generated from a random gra...
A distributed Nash equilibrium (NE) seeking algorithm is proposed for multi-agent systems under non-cooperative game settings, where players are subject to hybrid attacks composed of Denial-of-service (DoS) and false ...
详细信息
ISBN:
(数字)9798331508661
ISBN:
(纸本)9798331508678
A distributed Nash equilibrium (NE) seeking algorithm is proposed for multi-agent systems under non-cooperative game settings, where players are subject to hybrid attacks composed of Denial-of-service (DoS) and false data injection (FDI) attacks. The unknown dead-zone inputs are also taken into account for each agent. An event-triggered strategy is employed to enhance communication efficiency. With a topology reconstruction scheme, the impacts of hybrid attacks are mitigated. With the proposed event-triggered NE-seeking algorithm, the convergence of the distributed NE-seeking algorithm is analyzed, and an upper bound for the DoS attack time ratio is provided. Finally, the effectiveness of the algorithm is validated through numerical simulations.
Software-Based Self-Tests (SBST) allow at-speed, native online-testing of processors by running software programs on the processor core, requiring no Design for Testability (DfT) infrastructure. The creation of such S...
Software-Based Self-Tests (SBST) allow at-speed, native online-testing of processors by running software programs on the processor core, requiring no Design for Testability (DfT) infrastructure. The creation of such SBST programs often requires time-consuming manual labour that is expensive and requires in-depth knowledge of the processor’s architecture to target hard-to-test faults. In contrast, encoding the SBST generation task as a Bounded Model Checking (BMC) problem allows using sophisticated, state-of-the-art BMC solvers to automatically generate an SBST. Constraints for the BMC problem are encoded in a circuit called Validity Checker Module (VCM) and applied during SBST *** this paper, we focus on presenting a VCM architecture and a constraint set that allows building SBSTs that make minimal assumptions about the firmware, targeting hard-to-test faults in the ALU and register file of multiple scalar, in-order RISC-V processor families. The VCM architecture consists of a processor-specific mapping layer and a generic constraint set connected via a well-defined interface. The generic constraint set enforces the desired SBST behaviour, including controlling the processor’s pipeline state, memory accesses, and with that executed instructions, register state, and fault propagations. Using a generic constraint set allows for rapid SBST generation targeting new RISC-V processor families while keeping the generic constraints untouched. Lastly, we evaluate this approach on two RISC-V processor families, namely the DarkRISCV and a proprietary, industrial core showing the portability and strength of the approach, allowing for rapidly targeting new processors.
During the COVID-19 pandemic, the use of a people tracking system could have been crucial, particularly in sensitive environments, such as hospitals. DPPL Hallway Tracker is a framework that uses security camera foota...
详细信息
暂无评论