Due to hysteresis nonlinearity and load variation-induced low-damping resonance drift, the piezo-positioning stages struggle to achieve high-precision and high-speed tracking control. To address this issue, this paper proposes a less conservativeH∞loop-shaping controller design method based on the ν-gap metric. Resonance drift caused by load variations is modeled as coprime factor uncertainty, and the uncertainty boundaries are quantified by computing the ν-gap between the nominal model and frequency responses under varying load conditions. A parameter selection range is established based on the relationship between the robust stability margin and the ν-gap to guide the design of the weighting function, enhancing control performance while ensuring robust stability under varying load conditions. TheH∞LS controller is implemented using normalized coprime factor decomposition, which eliminates resonance peaks and reduces step response overshoot while preserving disturbance rejection capability. Experimental results under both no-load and 300 g load conditions show that, compared to the traditionalH∞LS, the proposed method reduces overshoot by 9.4% and 14.6%, and shortens settling time by 46.4% and 25.4%. Compared to the μ-synthesis method, the proposed method increases bandwidth by 68.4 Hz and 144.1 Hz, and decreases the maximum relative tracking error by 40.6% and 42.5%. These results validate the superiority of the proposed method.

In supervised learning, obtaining a large set of fully-labeled training data is expensive. We show that we do not always need full label information on every single training example to train a competent classifier. Specifically, inspired by the principle of sufficiency in statistics, we present a statistic (a summary) of the fully-labeled training set that captures almost all the relevant information for classification but at the same time is easier to obtain directly. We call this statistic "sufficiently-labeled data" and prove its sufficiency and efficiency for finding the optimal hidden representations, on which competent classifier heads can be trained using as few as a single randomly-chosen fully-labeled example per class. Sufficiently-labeled data can be obtained from annotators directly without collecting the fully-labeled data first. And we prove that it is easier to directly obtain sufficiently-labeled data than obtaining fully-labeled data. Furthermore, sufficiently-labeled data is naturally more secure since it stores relative, instead of absolute, information. Extensive experimental results are provided to support our theory.

While humans can effortlessly transform complex visual scenes into simple words and the other way around by leveraging their high-level understanding of the content, conventional or the more recent learned image compression codecs do not seem to utilize the semantic meanings of visual content to their full potential. Moreover, they focus mostly on rate-distortion and tend to underperform in perception quality especially in low bitrate regime, and often disregard the performance of downstream computer vision algorithms, which is a fast-growing consumer group of compressed images in addition to human viewers. In this paper, we (1) present a generic framework that can enable any image codec to leverage high-level semantics and (2) study the joint optimization of perception quality and distortion. Our idea is that given any codec, we utilize high-level semantics to augment the low-level visual features extracted by it and produce essentially a new, semantic-aware codec. We propose a three-phase training scheme that teaches semantic-aware codecs to leverage the power of semantic to jointly optimize rate-perception-distortion (R-PD) performance. As an additional benefit, semantic-aware codecs also boost the performance of downstream computer vision algorithms. To validate our claim, we perform extensive empirical evaluations and provide both quantitative and qualitative results.

By redefining the conventional notions of layers, we present an alternative view on finitely wide, fully trainable deep neural networks as stacked linear models in feature spaces, leading to a kernel machine interpretation. Based on this construction, we then propose a provably optimal modular learning framework for classification that does not require between-module backpropagation. This modular approach brings new insights into the label requirement of deep learning (DL). It leverages only implicit pairwise labels (weak supervision) when learning the hidden modules. When training the output module, on the other hand, it requires full supervision but achieves high label efficiency, needing as few as ten randomly selected labeled examples (one from each class) to achieve 94.88% accuracy on CIFAR-10 using a ResNet-18 backbone. Moreover, modular training enables fully modularized DL workflows, which then simplify the design and implementation of pipelines and improve the maintainability and reusability of models. To showcase the advantages of such a modularized workflow, we describe a simple yet reliable method for estimating reusability of pretrained modules as well as task transferability in a transfer learning setting. At practically no computation overhead, it precisely described the task space structure of 15 binary classification tasks from CIFAR-10.

We propose a novel family of connectionist models based on kernel machines and consider the problem of learning layer by layer a compositional hypothesis class (i.e., a feedforward, multilayer architecture) in a supervised setting. In terms of the models, we present a principled method to “kernelize” (partly or completely) any neural network (NN). With this method, we obtain a counterpart of any given NN that is powered by kernel machines instead of neurons. In terms of learning, when learning a feedforward deep architecture in a supervised setting, one needs to train all the components simultaneously using backpropagation (BP) since there are no explicit targets for the hidden layers (Rumelhart, Hinton, & Williams, 1986 ). We consider without loss of generality the two-layer case and present a general framework that explicitly characterizes a target for the hidden layer that is optimal for minimizing the objective function of the network. This characterization then makes possible a purely greedy training scheme that learns one layer at a time, starting from the input layer. We provide instantiations of the abstract framework under certain architectures and objective functions. Based on these instantiations, we present a layer-wise training algorithm for an [Formula: see text]-layer feedforward network for classification, where [Formula: see text] can be arbitrary. This algorithm can be given an intuitive geometric interpretation that makes the learning dynamics transparent. Empirical results are provided to complement our theory. We show that the kernelized networks, trained layer-wise, compare favorably with classical kernel machines as well as other connectionist models trained by BP. We also visualize the inner workings of the greedy kernelized models to validate our claim on the transparency of the layer-wise algorithm.

As the study for the modernization of Traditional Chinese Medicine (TCM) is moving continuously forward, a growing bond exists between TCM and modern information processing technology. The determination of syndrome and the study for the compatibility of medicines in TCM are main parts of it. In this paper, we clustered syndromes of lung cancer patients according to the clinical based cases by adopting Clustering Algorithm Based On Sparse Feature Vector algorithm (CABOSFV) algorithm and concluded three TCM classifications for lung cancer. Moreover, by the further study of the compatibility of medicines, numerous matches for critical medicines were proposed, and the results are correspond to clinical data.