1,780 research outputs found
A new error correction method for the stationary Navier-Stokes equations based on two local Gauss integrations
summary:A new error correction method for the stationary Navier-Stokes equations based on two local Gauss integrations is presented. Applying the orthogonal projection technique, we introduce two local Gauss integrations as a stabilizing term in the error correction method, and derive a new error correction method. In both the coarse solution computation step and the error computation step, a locally stabilizing term based on two local Gauss integrations is introduced. The stability and convergence of the new error correction algorithm are established. Numerical examples are also presented to verify the theoretical analysis and demonstrate the efficiency of the proposed method
Blow up solutions to a viscoelastic fluid system and a coupled Navier-Stokes/Phase-Field system in R^2
We find explicit solutions to both the Oldroyd-B model with infinite
Weissenberg number and the coupled Navier-Stokes/Phase-Field system. The
solutions blow up in finite time.Comment: 5 page
Research and Application of Access Control Technique in 3D Virtual Reality System OpenSim
Access control in 3-D virtual reality systems is a wide and still growing topic. A good access control model is a premise for data security, and makes the whole system play its functions reliably. We compare access control techniques in 3D system OpenSim with that of other virtual reality systems. By using a general extended scheme, we analyze the model and the rule of access control in OpenSim. In this scheme, we provide a method of expanding network services for special proposes. Meanwhile, it verifies the feasibility of developing OpenSim's services on the basis of data security
Model-Free 3D Shape Control of Deformable Objects Using Novel Features Based on Modal Analysis
Shape control of deformable objects is a challenging and important robotic
problem. This paper proposes a model-free controller using novel 3D global
deformation features based on modal analysis. Unlike most existing controllers
using geometric features, our controller employs a physically-based deformation
feature by decoupling 3D global deformation into low-frequency mode shapes.
Although modal analysis is widely adopted in computer vision and simulation, it
has not been used in robotic deformation control. We develop a new model-free
framework for modal-based deformation control under robot manipulation.
Physical interpretation of mode shapes enables us to formulate an analytical
deformation Jacobian matrix mapping the robot manipulation onto changes of the
modal features. In the Jacobian matrix, unknown geometry and physical
properties of the object are treated as low-dimensional modal parameters which
can be used to linearly parameterize the closed-loop system. Thus, an adaptive
controller with proven stability can be designed to deform the object while
online estimating the modal parameters. Simulations and experiments are
conducted using linear, planar, and solid objects under different settings. The
results not only confirm the superior performance of our controller but also
demonstrate its advantages over the baseline method.Comment: Accepted by the IEEE Transactions on Robotics. The paper will appear
in the IEEE Transactions on Robotics. IEEE copyrigh
Thermodynamics of the Reissner-Nordstr\"om-de Sitter Spacetime with Quintessence
For Anti-de Sitte (AdS) black holes, the isochoric heat capacity of system is
vanished, while the isobaric heat capacity is not. However, this situation does
not hold on for de Sitter (dS) black holes. In this work, by introducing the
interaction between the black hole horizon and the cosmological horizon of the
Reissner-Nordstr\"om-de Sitter (RNdS) spacetime with quintessence, we discuss
the phase transition of this system. The results show that the spacetime not
only has the similar phase transition behavior to that of Van der Waals (VdW)
system, and the non-vanishing isochoric heat capacity fulfills the whole
thermodynamics system. Through the discussion of the entropic force between two
horizons, we find out the role of entropic force in the evolution of spacetime.
In addition, we also study the influence of various parameters on the phase
transition and entropic force, which will provide a new method for exploring
the interaction among black hole molecules from a micro perspective
AutoML-GPT: Large Language Model for AutoML
With the emerging trend of GPT models, we have established a framework called
AutoML-GPT that integrates a comprehensive set of tools and libraries. This
framework grants users access to a wide range of data preprocessing techniques,
feature engineering methods, and model selection algorithms. Through a
conversational interface, users can specify their requirements, constraints,
and evaluation metrics. Throughout the process, AutoML-GPT employs advanced
techniques for hyperparameter optimization and model selection, ensuring that
the resulting model achieves optimal performance. The system effectively
manages the complexity of the machine learning pipeline, guiding users towards
the best choices without requiring deep domain knowledge. Through our
experimental results on diverse datasets, we have demonstrated that AutoML-GPT
significantly reduces the time and effort required for machine learning tasks.
Its ability to leverage the vast knowledge encoded in large language models
enables it to provide valuable insights, identify potential pitfalls, and
suggest effective solutions to common challenges faced during model training
- …