Unsupervised Domain Adaptive Detection with Network Stability Analysis

Domain adaptive detection aims to improve the generality of a detector, learned from the labeled source domain, on the unlabeled target domain. In this work, drawing inspiration from the concept of stability from the control theory that a robust system requires to remain consistent both externally and internally regardless of disturbances, we propose a novel framework that achieves unsupervised domain adaptive detection through stability analysis. In specific, we treat discrepancies between images and regions from different domains as disturbances, and introduce a novel simple but effective Network Stability Analysis (NSA) framework that considers various disturbances for domain adaptation. Particularly, we explore three types of perturbations including heavy and light image-level disturbances and instancelevel disturbance. For each type, NSA performs external consistency analysis on the outputs from raw and perturbed images and/or internal consistency analysis on their features, using teacher-student models. By integrating NSA into Faster R-CNN, we immediately achieve state-of-the-art results. In particular, we set a new record of 52.7% mAP on Cityscapes-to-FoggyCityscapes, showing the potential of NSA for domain adaptive detection. It is worth noticing, our NSA is designed for general purpose, and thus applicable to one-stage detection model (e.g., FCOS) besides the adopted one, as shown by experiments. https://github.com/tiankongzhang/NSA

Aperture Sharing Metasurface-Based Wide-Beam Antenna for Energy Harvesting

Since the available ambient power level is usually quite low for radio frequency energy harvesting, it is very desirable for an antenna to have both a high gain and a wide beamwidth. Usually, they cannot be achieved simultaneously. In order to overcome this limitation, a multi-port antenna using a nonuniform metasurface (MTS) is presented. In this MTS-based antenna, three modes with complementary radiation patterns are excited through one middle and two side aperture-coupled feeding ports. The first mode is the fundamental TM10 mode with in-phase current distributions on the MTS. It has a broadside directional radiation pattern with a high gain. The second and third modes are symmetrical to each other at a high mode. They have opposite current distributions on two sides of the MTS. These two modes have a directional radiation pattern with a tilted angle. These three modes share the same aperture but are excited by three different feeds. Each feed is connected to a rectifier. By combining direct current (DC) output to a single load, an antenna with a wide beam and a high gain can be effectively achieved, although each mode has the usual limitation of gain and beamwidth. The key advantage of this proposed rectenna is that the unit cells on the MTS layer can be reused to excite different MTS modes with different radiation patterns simultaneously. Thus, a wide beamwidth can be achieved. Three realized beams are oriented at −35°, 0°, and + 35° respectively. By combining the DC output from the three modes, the proposed rectenna has effectively achieved a beamwidth of 114° with a gain ranging from 8 to 9.8 dBi. The RF-to-DC conversion efficiency of the rectifiers is 3%-67% at 2.45 GHz when the input power ranges from −35 to 0 dBm. The proposed MTS antenna with an overall size of λ0 × λ0 × 0.03 λ0 can achieve 12% fractional bandwidth

Structural basis of PROTAC cooperative recognition for selective protein degradation

Inducing macromolecular interactions with small molecules to activate cellular signaling is a challenging goal. PROTACs (proteolysis-targeting chimeras) are bifunctional molecules that recruit a target protein in proximity to an E3 ubiquitin ligase to trigger protein degradation. Structural elucidation of the key ternary ligase-PROTAC-target species and its impact on target degradation selectivity remain elusive. We solved the crystal structure of Brd4 degrader MZ1 in complex with human VHL and the Brd4 bromodomain (Brd4BD2). The ligand folds into itself to allow formation of specific intermolecular interactions in the ternary complex. Isothermal titration calorimetry studies, supported by surface mutagenesis and proximity assays, are consistent with pronounced cooperative formation of ternary complexes with Brd4BD2. Structure-based-designed compound AT1 exhibits highly selective depletion of Brd4 in cells. Our results elucidate how PROTAC-induced de novo contacts dictate preferential recruitment of a target protein into a stable and cooperative complex with an E3 ligase for selective degradation

Sparse Haar-Like Feature and Image Similarity-Based Detection Algorithm for Circular Hole of Engine Cylinder Head

If the circular holes of an engine cylinder head are distorted, cracked, defective, etc., the normal running of the equipment will be affected. For detecting these faults with high accuracy, this paper proposes a detection method based on feature point matching, which can reduce the detection error caused by distortion and light interference. First, the effective and robust feature vectors of pixels are extracted based on improved sparse Haar-like features. Then we calculate the similarity and find the most similar matching point from the image. In order to improve the robustness to the illumination, this paper uses the method based on image similarity to map the original image, so that the same region under different illumination conditions has similar spatial distribution. The experiments show that the algorithm not only has high matching accuracy, but also has good robustness to the illumination

When Religious Folk Practice Meet Karl Marx: Courts’ Response to Ghost Marriage in Modern China

As religious folk practice is regarded as a radical departure from Marxist atheism, the abnormal existence of ghost marriages under the Chinese socialist regime has attracted wide scholarly attention in anthropology and sociology. However, few scholars have focused on how Chinese courts treat religious folk practices, such as ghost marriages, despite the official socialist ideology. Based on the typological analysis and case study involving 260 ghost marriage cases, the authors argue about the judicial activism of Chinese courts towards atheist ideology in religious folk practices. The findings of this study are twofold. First, the Chinese courts’ attitudes toward ghost marriage cases are pluralistic, reflecting the Chinese legal system’s selective obedience to the socialist ideology. Through the application of different legal interpretations of relevant laws, Chinese courts have shown three attitudes towards ghost marriages: encouragement, tolerance, and suppression. The first two attitudes can be regarded as supportive supervision of religious folk practice. Three factors tended to affect the courts’ attitudes towards ghost marriages: courts’ hierarchical level, parties’ claims, and whether ghost marriage rituals are performed. Second, further analysis suggests that RPC’s guerrilla-style governance strategy in the Chinese legal system allows it to deal with ghost marriage with more flexibility, even overriding its fundamentalist ideology. The guerrilla-style tactic is often used by the Chinese courts to handle matters of religious folk practices in a pluralistic manner. Overall, the courts’ pluralistic attitudes towards ghost marriage is that of modest tolerance and cooperation of religious folk practices based on the RPC’s model of governance

Sparse Haar-Like Feature and Image Similarity-Based Detection Algorithm for Circular Hole of Engine Cylinder Head

If the circular holes of an engine cylinder head are distorted, cracked, defective, etc., the normal running of the equipment will be affected. For detecting these faults with high accuracy, this paper proposes a detection method based on feature point matching, which can reduce the detection error caused by distortion and light interference. First, the effective and robust feature vectors of pixels are extracted based on improved sparse Haar-like features. Then we calculate the similarity and find the most similar matching point from the image. In order to improve the robustness to the illumination, this paper uses the method based on image similarity to map the original image, so that the same region under different illumination conditions has similar spatial distribution. The experiments show that the algorithm not only has high matching accuracy, but also has good robustness to the illumination