Extending high value components performances with Additive Manufacturing: application to naval applications
本文探讨了使用线弧增材制造(WAAM)技术来提高高价值组件性能,特别是通过制造1.5米高的空心螺旋桨叶片示范件在海军应用中的潜力。
本文探讨了使用线弧增材制造(WAAM)技术来提高高价值组件性能,特别是通过制造1.5米高的空心螺旋桨叶片示范件在海军应用中的潜力。
本文提出了一种准静态分析方法,用于评估欠驱动多指手的被动稳定性,并通过一种新的集成了差动弹簧滑块机制的三指手架构,研究了不同物体尺寸下的稳定抓取配置。
This work addresses the challenges of kinematic redundancy and task-space decoupling in serial manipulators performing low-degree-of-freedom tasks. To overcome these issues, the authors propose a geometrically defined screw projector that directly decomposes the end-effector twist into task-relevant and redundant components, thereby establishing a compact inverse kinematics framework. Unlike conventional approaches relying on Jacobian null-space projection, this method leverages geometric screw decomposition to intuitively separate motions inside and outside the task space, offering a unified treatment of both kinematic and task redundancy. Experimental results demonstrate that the proposed approach enables efficient, intuitive, and natural motion control while effectively managing redundancy.
This work addresses the susceptibility of Transformer-based models to historical trajectory interference in backtracking search tasks, which undermines their ability to make consistent decisions based solely on the current state. To mitigate this issue, the authors propose Selective State Attention (SSA), a novel mechanism that employs structured attention masks and trace-level localization to constrain decoder-style Transformers to reason exclusively from the current search state—without requiring modifications to training data or objectives. Evaluated across diverse domains including 3-SAT, graph coloring, Blocks World, and backtracking parsing, SSA consistently produces identical outputs for identical states despite varying histories, significantly outperforming baseline models and demonstrating its efficacy in enhancing state-dependent decision-making capabilities.
This work addresses the challenge of optimizing complex loss functions—such as Kullback–Leibler divergence or PDE residuals—over nonlinear manifolds like neural or tensor networks, where conventional and natural gradient descent often converge to suboptimal local minima with inefficient update directions. The paper introduces, for the first time, a momentum-augmented variant of natural gradient descent that integrates Heavy-Ball and Nesterov-type inertial mechanisms into a manifold-aware optimization framework. By leveraging tangent-space projections and Gram matrix preconditioning, the method achieves momentum-driven, locally optimal updates directly in function space. Empirical results demonstrate substantial improvements in convergence behavior for tasks including density estimation and physics-informed learning, effectively mitigating poor local minima and enhancing the quality of optimization trajectories.
本文探讨了使用线弧增材制造(WAAM)技术来提高高价值组件性能,特别是通过制造1.5米高的空心螺旋桨叶片示范件在海军应用中的潜力。
本文提出了一种准静态分析方法,用于评估欠驱动多指手的被动稳定性,并通过一种新的集成了差动弹簧滑块机制的三指手架构,研究了不同物体尺寸下的稳定抓取配置。
This work addresses the challenges of kinematic redundancy and task-space decoupling in serial manipulators performing low-degree-of-freedom tasks. To overcome these issues, the authors propose a geometrically defined screw projector that directly decomposes the end-effector twist into task-relevant and redundant components, thereby establishing a compact inverse kinematics framework. Unlike conventional approaches relying on Jacobian null-space projection, this method leverages geometric screw decomposition to intuitively separate motions inside and outside the task space, offering a unified treatment of both kinematic and task redundancy. Experimental results demonstrate that the proposed approach enables efficient, intuitive, and natural motion control while effectively managing redundancy.
This work addresses the susceptibility of Transformer-based models to historical trajectory interference in backtracking search tasks, which undermines their ability to make consistent decisions based solely on the current state. To mitigate this issue, the authors propose Selective State Attention (SSA), a novel mechanism that employs structured attention masks and trace-level localization to constrain decoder-style Transformers to reason exclusively from the current search state—without requiring modifications to training data or objectives. Evaluated across diverse domains including 3-SAT, graph coloring, Blocks World, and backtracking parsing, SSA consistently produces identical outputs for identical states despite varying histories, significantly outperforming baseline models and demonstrating its efficacy in enhancing state-dependent decision-making capabilities.
This work addresses the challenge of optimizing complex loss functions—such as Kullback–Leibler divergence or PDE residuals—over nonlinear manifolds like neural or tensor networks, where conventional and natural gradient descent often converge to suboptimal local minima with inefficient update directions. The paper introduces, for the first time, a momentum-augmented variant of natural gradient descent that integrates Heavy-Ball and Nesterov-type inertial mechanisms into a manifold-aware optimization framework. By leveraging tangent-space projections and Gram matrix preconditioning, the method achieves momentum-driven, locally optimal updates directly in function space. Empirical results demonstrate substantial improvements in convergence behavior for tasks including density estimation and physics-informed learning, effectively mitigating poor local minima and enhancing the quality of optimization trajectories.