GeoLayoutLM: Geometric Pre-training for Visual Information Extraction

Visual information extraction (VIE) plays an important role in Document Intelligence. Generally, it is divided into two tasks: semantic entity recognition (SER) and relation extraction (RE). Recently, pre-trained models for documents have achieved substantial progress in VIE, particularly in SER. However, most of the existing models learn the geometric representation in an implicit way, which has been found insufficient for the RE task since geometric information is especially crucial for RE. Moreover, we reveal another factor that limits the performance of RE lies in the objective gap between the pre-training phase and the fine-tuning phase for RE. To tackle these issues, we propose in this paper a multi-modal framework, named GeoLayoutLM, for VIE. GeoLayoutLM explicitly models the geometric relations in pre-training, which we call geometric pre-training. Geometric pre-training is achieved by three specially designed geometry-related pre-training tasks. Additionally, novel relation heads, which are pre-trained by the geometric pre-training tasks and fine-tuned for RE, are elaborately designed to enrich and enhance the feature representation. According to extensive experiments on standard VIE benchmarks, GeoLayoutLM achieves highly competitive scores in the SER task and significantly outperforms the previous state-of-the-arts for RE (\eg, the F1 score of RE on FUNSD is boosted from 80.35\% to 89.45\%). The code and models are publicly available at https://github.com/AlibabaResearch/AdvancedLiterateMachinery/tree/main/DocumentUnderstanding/GeoLayoutLMComment: CVPR 2023 Highligh

Tailoring MoS2 Valley-Polarized Photoluminescence with Super Chiral Near-Field

Transition metal dichalcogenides with intrinsic spin–valley degrees of freedom hold great potentials for applications in spintronic and valleytronic devices. MoS2 monolayer possesses two inequivalent valleys in the Brillouin zone, with each valley coupling selectively with circularly polarized photons. The degree of valley polarization (DVP) is a parameter to characterize the purity of valley-polarized photoluminescence (PL) of MoS2 monolayer. Usually, the detected values of DVP in MoS2 monolayer show achiral property under optical excitation of opposite helicities due to reciprocal phonon-assisted intervalley scattering process. Here, it is reported that valley-polarized PL of MoS2 can be tailored through near-field interaction with plasmonic chiral metasurface. The resonant field of the chiral metasurface couples with valley-polarized excitons, and tailors the measured PL spectra in the far-field, resulting in observation of chiral DVP of MoS2-metasurface under opposite helicities excitations. Valley-contrast PL in the chiral heterostructure is also observed when illuminated by linearly polarized light. The manipulation of valley-polarized PL in 2D materials using chiral metasurface represents a viable route toward valley-polaritonic devices

Metal contact and carrier transport in single crystalline CH3NH3PbBr3 perovskite

Organic-inorganic perovskites have arrived at the forefront of solar technology due to their impressive carrier lifetimes and superior optoelectronic properties. By having the cm-sized perovskite single crystal and employing device patterning techniques, and the transfer length method (TLM), we are able to get the insight into the metal contact and carrier transport behaviors, which is necessary for maximizing device performance and efficiency. In addition to the metal work function, we found that the image force and interface charge pinning effects also affect the metal contact, and the studied single crystal CH3NH3PbBr3 features Schottky barriers of 0.17 eV, 0.38 eV, and 0.47 eV for Au, Pt, and Ti electrodes, respectively. Furthermore, the surface charges lead to the thermally activated transport from 207 K to 300 K near the perovskite surface. In contrast, from 120 K to 207 K, the material exhibited three-dimensional (3D) variable range hopping (VRH) carrier transport behavior. Understanding these fundamental contact and transport properties of perovskite will enable future electronic and optoelectronic applications

Photonic Weyl points due to broken time-reversal symmetry in magnetized semiconductor

Weyl points are discrete locations in the three-dimensional momentum space where two bands cross linearly with each other. They serve as the monopoles of Berry curvature in the momentum space, and their existence requires breaking of either time-reversal or inversion symmetry. Although various non-centrosymmetric Weyl systems have been reported, demonstration of Weyl degeneracies due to breaking of the time-reversal symmetry remains scarce and is limited to electronic systems. Here, we report the experimental observation of photonic Weyl degeneracies in a magnetized semiconductor—InSb, which behaves as a magnetized plasma19 for electromagnetic waves at the terahertz band. By varying the magnetic field strength, Weyl points and the corresponding photonic Fermi arcs have been demonstrated. Our observation establishes magnetized semiconductors as a reconfigurable terahertz Weyl system, which may prompt research on novel magnetic topological phenomena such as chiral Majorana-type edge states and zero modes in classic systems

Improved link analysis method for user interface design - modified link table and optimisation-based algorithm

Link analysis (LA) is one of most widely used methods in user interface design to arrange control elements on user interfaces. However, traditional LA method is insufficient for evaluating transitional cost associated with accessibility (the easiness for the operator to reach certain control element on the interface) and the link table commonly used contains no directional information for assessing difficulty. To address these two problems, an improved LA method based on a modified link table and a branch-and-bound algorithm is proposed in this study. A case study on a simplified control interface of a boiling water reactor (BWR) in a real-world nuclear control system was exemplified to elucidate the improved method and an experiment was conducted to validate the effectiveness of the method in improving users' performance time. The results showed that the total completion time (CT) and the completion time of accessibility-associated operations were significantly shorter on the interface modified by the improved method than by the traditional LA method, while the difference of the completion time of proximity-associated operations between the two interfaces was non-significant. Therefore, although the traditional LA method can significantly ameliorate the random interface by optimising the proximity between control elements, the improved method can further improve the CT by optimally trading off the accessibility and proximity. The method can be applied to the interface which requires physical movements between the user and the interface and within the interface, especially touch screen and control panels

Improved Link Analysis Method for User Interface Design---Modified Link Table and Optimization-based Algorithm

Link analysis is one of most wildly used methods in user interface design to arrange control elements on user interfaces. However, traditional link analysis method is insufficient for evaluating transitional cost associated with accessibility (the easiness for the operator to reach certain control element on the interface) and the link table commonly used contains no directional information for assessing difficulty. To address these two problems, an improved link analysis method based on a modified link table and a branch-and-bound algorithm is proposed in this study. A case study on a simplified control interface of a boiling water reactor (BWR) in a real-world nuclear control system was exemplified to elucidate the improved method and an experiment was conducted to validate the effectiveness of the method in improving users’ performance time. The results showed that the total completion time and the completion time of accessibility-associated operations were significantly shorter on the interface modified by the improved method than by the traditional link analysis method,while the difference of the completion time of proximity-associated operations between the two interfaces was non-significant. Therefore, although the traditional link analysis method cansignificantly ameliorate the random interface by optimizing the proximity between control elements, the improved method can further improve the total completion time by optimally trading-off the accessibility and proximity. The method can be applied to the interface which requires physical movements between the user and the interface and within the interface, especially touch screen and control panels

Improved Link Analysis Method for User Interface Design---Modified Link Table and Optimization-based Algorithm

Link analysis is one of most wildly used methods in user interface design to arrange control elements on user interfaces. However, traditional link analysis method is insufficient for evaluating transitional cost associated with accessibility (the easiness for the operator to reach certain control element on the interface) and the link table commonly used contains no directional information for assessing difficulty. To address these two problems, an improved link analysis method based on a modified link table and a branch-and-bound algorithm is proposed in this study. A case study on a simplified control interface of a boiling water reactor (BWR) in a real-world nuclear control system was exemplified to elucidate the improved method and an experiment was conducted to validate the effectiveness of the method in improving users’ performance time. The results showed that the total completion time and the completion time of accessibility-associated operations were significantly shorter on the interface modified by the improved method than by the traditional link analysis method,while the difference of the completion time of proximity-associated operations between the two interfaces was non-significant. Therefore, although the traditional link analysis method cansignificantly ameliorate the random interface by optimizing the proximity between control elements, the improved method can further improve the total completion time by optimally trading-off the accessibility and proximity. The method can be applied to the interface which requires physical movements between the user and the interface and within the interface, especially touch screen and control panels

Perspectives on tissue-like bioelectronics for neural modulation

Summary: Advances in bioelectronic implants have been offering valuable chances to interface and modulate neural systems. Potential mismatches between bioelectronics and targeted neural tissues require devices to exhibit “tissue-like” properties for better implant-bio integration. In particular, mechanical mismatches pose a significant challenge. In the past years, efforts were made in both materials synthesis and device design to achieve bioelectronics mechanically and biochemically mimicking biological tissues. In this perspective, we mainly summarized recent progress of developing “tissue-like” bioelectronics and categorized them into different strategies. We also discussed how these “tissue-like” bioelectronics were utilized for modulating in vivo nervous systems and neural organoids. We concluded the perspective by proposing further directions including personalized bioelectronics, novel materials design and the involvement of artificial intelligence and robotic techniques