Phase unwrapping (PU) is a technique to reconstruct original phase images from their noisy wrapped counterparts, finding many applications in scientific imaging. Although supervised learning has shown promise in PU, its utility is limited in ground-truth (GT) scarce scenarios. This paper presents an unsupervised learning approach that eliminates the need for GTs during end-to-end training. Our approach leverages the insight that both the gradients and wrapped gradients of wrapped phases serve as noisy labels for GT phase gradients, along with sparse outliers induced by the wrapping operation. A recorruption-based self-reconstruction loss in the gradient domain is proposed to mitigate the adverse effects of label noise, complemented with a self-distillation loss for improved generalization. Additionally, by unfolding a variational model of PU that utilizes wrapped gradients of wrapped phases for its data-fitting term, we develop a deep unrolling network that encodes physics of phase wrapping and incorporates special treatments on outliers. In the experiments on three types of phase data, our approach outperforms existing GT-free methods and competes well against the supervised ones.

Texture representation is a challenging problem due to the complex underlying physics of texture as well as the variations caused by changes in viewpoint. Recent progress in texture analysis has been made by the power of convolutional neural networks (CNNs) in feature learning . However, most current methods aggregate the features from the last convolutional layer of the CNN to obtain a global feature vector, which fails to leverage shallow low-level visual cues and cross-layer feature patterns, limiting their performance. In this paper, we propose to trace the features generated along the convolutional layers via a histogram of local 3D invariant binary patterns, called deep tracing patterns. This leads to a highly discriminative yet robust global feature representation module. Building such a module into a CNN backbone, we develop an effective approach for texture recognition. Extensive experiments on six benchmark datasets show that the proposed approach provides a discriminative and robust texture descriptor , with state-of-the-art performance achieved.

Phase retrieval (PR) is a challenging nonlinear inverse problem in scientific imaging that involves reconstructing the phase of a signal from its intensity measurements. Recently, there has been an increasing interest in deep learning-based PR. Motivated by the challenge of collecting ground-truth (GT) images in many domains, this paper proposes a fully-unsupervised learning approach for PR, which trains an end-to-end deep model via a GT-free teacher-student online distillation framework. Specifically, a teacher model is trained using a self-expressive loss with noise resistance, while a student model is trained with a consistency loss on augmented data to exploit the teacher's dark knowledge. Additionally, we develop an enhanced unfolding network for both the teacher and student models. Extensive experiments show that our proposed approach outperforms existing unsupervised PR methods with higher computational efficiency and performs competitively against supervised methods.

To effectively boost computer usage, machine learning models are used in several phishing detection systems to classify enormous phishing datasets. Based on phishing patterns, researchers prefer to extract a considerable number of features to improve phishing detection performance. However, redundant and useless features in the feature set degrade the performance of the underlying classification models. In addition, several existing phishing detection models mainly focus on detection accuracy and overlook recall rates. However, in phishing detection, it is more harmful to falsely detect a phishing website as a legitimate website than it is to detect a legitimate website as a phishing website. This study proposes a novel phishing detection model, multi-objective evolution/random forest (MOE/RF), which is based on the revised multi-objective evolution optimization algorithm (MOE) and random forest (RF). The MOE/RF model uses accuracy as the detection target and minimizes the probability of false detection of phishing sites. In addition, two new strategies, the symmetric uncertainty-based population initialization and the population state-based adaptive environmental selection, are proposed to improve the performance of the MOE. Experimental results on testing five different phishing datasets demonstrated that the MOE/RF performs superior to several existing methods.

In recent years, convolutional neural networks (CNNs) have become a prominent tool for texture recognition. The key of existing CNN-based approaches is aggregating the convolutional features into a robust yet discriminative description. This paper presents a novel feature aggregation module called CLASS (Cross-Layer Aggregation of Statistical Self-similarity) for texture recognition. We model the CNN feature maps across different layers, as a dynamic process which carries the statistical self-similarity (SSS), one well-known property of texture, from input image along the network depth dimension. The CLASS module characterizes the cross-layer SSS using a soft histogram of local differential box-counting dimensions of cross-layer features. The resulting descriptor encodes both cross-layer dynamics and local SSS of input image, providing additional discrimination over the often-used global average pooling. Integrating CLASS into a ResNet backbone, we develop CLASSNet, an effective deep model for texture recognition, which shows state-of-the-art performance in the experiments.

Existing convolutional neural networks (CNNs) often use global average pooling (GAP) to aggregate feature maps into a single representation. However, GAP cannot well characterize complex distributive patterns of spatial features while such patterns play an important role in texture-oriented applications, e.g., material recognition and ground terrain classification. In the context of texture representation, this paper addressed the issue by proposing Fractal Encoding (FE), a feature encoding module grounded by multi-fractal geometry. Considering a CNN feature map as a union of level sets of points lying in the 2D space, FE characterizes their spatial layout via a local-global hierarchical fractal analysis which examines the multi-scale power behavior on each level set. This enables a CNN to encode the regularity on the spatial arrangement of image features, leading to a robust yet discriminative spectrum descriptor. In addition, FE has trainable parameters for data adaptivity and can be easily incorporated into existing CNNs for end-to-end training. We applied FE to ResNet-based texture classification and retrieval, and demonstrated its effectiveness on several benchmark datasets.

This paper presents a novel low cost and double node upset (DNU) online self-recoverable latch design using radiation hardening by design (RHBD) technology. The latch mainly consists of 8 interlocked input-split inverters. Since all internal nodes are interlocked, if any of the possible node pairs occurs a DNU, the latch can restore back. Simulation results have demonstrated the DNU online self-recoverability and also demonstrated that the proposed latch design saves 71.68% transmission delay, 72.92% power dissipation and 93.69% comprehensive delay-power-area product (DPAP) on average, compared with the up-to-date DNU online self-recoverable latch designs.

This paper presents a novel double-node upset (DNU) tolerant latch through radiation-hardening-by-design combined with layout technique. The latch mainly comprises 6 interlocked cross-coupled input-split inverters. Due to the special feedback rules for the internal nodes, many interlocked feedback loops are constructed in the latch and the following robustness is achieved: 1) In the case of 0 being held, the latch can self-recover from any single node upset (SNU), any DNU including double-adjacent-node upset (DANU) and double-separated-node upset (DSNU); 2) In the case of 1 being held, the latch can self-recover from any SNU, any DANU and partial DSNU. However, using layout technique, as for any DSNU-sensitive node-pair, the nodes are separated, thus the latch can avoid any DSNU. Simulation results demonstrate the robustness of the proposed latch. Besides, compared with typical existing DNU hardened latch designs, the proposed latch approximately saves 80.25% area-power-delay product on average.