6,090 research outputs found
Bi-collinear antiferromagnetic order in the tetragonal -FeTe
By the first-principles electronic structure calculations, we find that the
ground state of PbO-type tetragonal -FeTe is in a bi-collinear
antiferromagnetic state, in which the Fe local moments () are
ordered ferromagnetically along a diagonal direction and antiferromagnetically
along the other diagonal direction on the Fe square lattice. This bi-collinear
order results from the interplay among the nearest, next nearest, and next next
nearest neighbor superexchange interactions , , and , mediated
by Te -band. In contrast, the ground state of -FeSe is in the
collinear antiferromagnetic order, similar as in LaFeAsO and BaFeAs.Comment: 5 pages and 5 figure
Sliding Mode Control of Cable-Driven Redundancy Parallel Robot with 6 DOF Based on Cable-Length Sensor Feedback
The sliding mode control of the cable-driven redundancy parallel robot with six degrees of freedom is studied based on the cable-length sensor feedback. Under the control scheme of task space coordinates, the cable length obtained by the cable-length sensor is used to solve the forward kinematics of the cable-driven redundancy parallel robot in real-time, which is treated as the feedback for the control system. First, the method of forward kinematics of the cable-driven redundancy parallel robot is proposed based on the tetrahedron method and Levenberg-Marquardt method. Then, an iterative initial value estimation method for the Levenberg-Marquardt method is proposed. Second, the sliding mode control method based on the exponential approach law is used to control the effector of the robot, and the influence of the sliding mode parameters on control performance is simulated. Finally, a six-degree-of-freedom position tracking experiment is carried out on the principle prototype of the cable-driven redundancy parallel robot. The experimental results show that the robot can accurately track the desired position in six directions, which indicates that the control method based on the cable-length sensor feedback for the cable-driven redundancy parallel robot is effective and feasible
Polytypism and Unexpected Strong Interlayer Coupling of two-Dimensional Layered ReS2
The anisotropic two-dimensional (2D) van der Waals (vdW) layered materials,
with both scientific interest and potential application, have one more
dimension to tune the properties than the isotropic 2D materials. The
interlayer vdW coupling determines the properties of 2D multi-layer materials
by varying stacking orders. As an important representative anisotropic 2D
materials, multilayer rhenium disulfide (ReS2) was expected to be random
stacking and lack of interlayer coupling. Here, we demonstrate two stable
stacking orders (aa and a-b) of N layer (NL, N>1) ReS2 from ultralow-frequency
and high-frequency Raman spectroscopy, photoluminescence spectroscopy and
first-principles density functional theory calculation. Two interlayer shear
modes are observed in aa-stacked NL-ReS2 while only one interlayer shear mode
appears in a-b-stacked NL-ReS2, suggesting anisotropic-like and isotropic-like
stacking orders in aa- and a-b-stacked NL-ReS2, respectively. The frequency of
the interlayer shear and breathing modes reveals unexpected strong interlayer
coupling in aa- and a-b-NL-ReS2, the force constants of which are 55-90% to
those of multilayer MoS2. The observation of strong interlayer coupling and
polytypism in multi-layer ReS2 stimulate future studies on the structure,
electronic and optical properties of other 2D anisotropic materials
BuildMapper: A Fully Learnable Framework for Vectorized Building Contour Extraction
Deep learning based methods have significantly boosted the study of automatic
building extraction from remote sensing images. However, delineating vectorized
and regular building contours like a human does remains very challenging, due
to the difficulty of the methodology, the diversity of building structures, and
the imperfect imaging conditions. In this paper, we propose the first
end-to-end learnable building contour extraction framework, named BuildMapper,
which can directly and efficiently delineate building polygons just as a human
does. BuildMapper consists of two main components: 1) a contour initialization
module that generates initial building contours; and 2) a contour evolution
module that performs both contour vertex deformation and reduction, which
removes the need for complex empirical post-processing used in existing
methods. In both components, we provide new ideas, including a learnable
contour initialization method to replace the empirical methods, dynamic
predicted and ground truth vertex pairing for the static vertex correspondence
problem, and a lightweight encoder for vertex information extraction and
aggregation, which benefit a general contour-based method; and a well-designed
vertex classification head for building corner vertices detection, which casts
light on direct structured building contour extraction. We also built a
suitable large-scale building dataset, the WHU-Mix (vector) building dataset,
to benefit the study of contour-based building extraction methods. The
extensive experiments conducted on the WHU-Mix (vector) dataset, the WHU
dataset, and the CrowdAI dataset verified that BuildMapper can achieve a
state-of-the-art performance, with a higher mask average precision (AP) and
boundary AP than both segmentation-based and contour-based methods
A Novel Image Classification Approach for Maize Diseases Recognition
Background: The spot, streak and rust are the most common diseases in maize, all of which require effective methods to recognize, diagnose and handle. This paper presents a novel image classification approach to the high accuracy recognition of these maize diseases.
Methods: Firstly, the k-means clustering algorithm is deployed in LAB color space to reduce the influence of image noise and irrelevant background, so that the area of maize diseases could be effectively extracted. Then the statistic pattern recognition method and gray level co-occurrence matrix (GLCM) method are jointly used to segment the maize disease leaf images for accurately obtaining their texture, shape and color features. Finally, Support Vector Machine (SVM) classification method is used to identify three diseases.
Results: Numerical results clearly demonstrate the feasibility and effectiveness of the proposed method.
Conclusion: Our future work will focus on the investigation of how to use the new classification methods in dimensional and large scale data to improve the recognizing performance and how to use other supervised feature selection methods to improve the accuracy further
Unleashing Cognitive Synergy in Large Language Models: A Task-Solving Agent through Multi-Persona Self-Collaboration
Human intelligence thrives on the concept of cognitive synergy, where
collaboration and information integration among different cognitive processes
yield superior outcomes compared to individual cognitive processes in
isolation. Although Large Language Models (LLMs) have demonstrated promising
performance as general task-solving agents, they still struggle with tasks that
require intensive domain knowledge and complex reasoning. In this work, we
propose Solo Performance Prompting (SPP), which transforms a single LLM into a
cognitive synergist by engaging in multi-turn self-collaboration with multiple
personas. A cognitive synergist refers to an intelligent agent that
collaborates with multiple minds, combining their individual strengths and
knowledge, to enhance problem-solving and overall performance in complex tasks.
By dynamically identifying and simulating different personas based on task
inputs, SPP unleashes the potential of cognitive synergy in LLMs. We have
discovered that assigning multiple, fine-grained personas in LLMs elicits
better problem-solving abilities compared to using a single or fixed number of
personas. We evaluate SPP on three challenging tasks: Trivia Creative Writing,
Codenames Collaborative, and Logic Grid Puzzle, encompassing both
knowledge-intensive and reasoning-intensive types. Unlike previous works, such
as Chain-of-Thought, that solely enhance the reasoning abilities in LLMs, SPP
effectively elicits internal knowledge acquisition abilities, reduces
hallucination, and maintains strong reasoning capabilities. Code, data, and
prompts can be found at:
https://github.com/MikeWangWZHL/Solo-Performance-Prompting.git.Comment: work in progres
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