Woven curvature

It started with reading water, I analog the water movement with water painting.(wet stripes on tracing paper) The wet strips attached on the tracing paper grow longer and shorter, Because of this surface tension, the surface creates certain wrinkle patterns(Wrinkle_from PIE root *wer” to turn, bend.”), which I call ‘breathing surface’ for its sense of life. It expresses the strength, durability, and continuity of water. As I zoomed into the surface tension phenomenon, I started to think about a type of architectural experience which is a gradual change rather than dramatic. Through floor to floor, wall to wall, beginning to the end. The elements constantly change their angle and width,---(they merge or embed one another) and things get more ambiguous as the body travels through space. Cone&Cylinder, as 2 basic developable surface geometry, can be unfolded without distortion. conversely, it is a surface which can be made by transforming a plane(folding, bending, rolling, cutting and gluing).They provide a wide range of possibilities for spatial continuity. The thesis will continue to focus on the study of breathing surface through reading water along with geometry study of developable surface, to transfer the geometrical information into spatial continuity and other architectural conditions. summary: explore how the surface reacts to the material’s behavior. -\u3e find order of geometry & developable surface caused by the surface tension phenomenon -\u3e transfer this information into architectural experience through spatial continuity

Large deviations and fluctuation theorems for cycle currents defined in the loop-erased and spanning tree manners: a comparative study

The cycle current is a crucial quantity in stochastic thermodynamics. The absolute and net cycle currents of a Markovian system can be defined in the loop-erased (LE) or the spanning tree (ST) manner. Here we make a comparative study between the large deviations and fluctuation theorems for the LE and ST currents, i.e. cycle currents defined in the LE and ST manners. First, we derive the exact joint distribution and the large deviation rate function for the LE currents of a system with a cyclic topology and also obtain the rate function for the ST currents of a general system. The relationship between the rate functions for the LE and ST currents is clarified. Furthermore, we examine various types of fluctuation theorems satisfied by the LE and ST currents and clarify their ranges of applicability. We show that both the absolute and net LE currents satisfy the strong form of all types of fluctuation theorems. In contrast, the absolute ST currents do not satisfy fluctuation theorems, while the net ST currents only satisfy the weak form of fluctuation theorems under the periodic boundary condition

Tunable Dynamic Walking via Soft Twisted Beam Vibration

We propose a novel mechanism that propagates vibration through soft twisted beams, taking advantage of dynamically-coupled anisotropic stiffness to simplify the actuation of walking robots. Using dynamic simulation and experimental approaches, we show that the coupled stiffness of twisted beams with terrain contact can be controlled to generate a variety of complex trajectories by changing the frequency of the input signal. This work reveals how ground contact influences the system's dynamic behavior, supporting the design of walking robots inspired by this phenomenon. We also show that the proposed twisted beam produces a tunable walking gait from a single vibrational input.Comment: 8 pages, 5 figure, this paper has been submitted to IEEE Robotics and Automation Letters, copyright may be transferred without notice, after which this version may no longer be accessible, the supplemental video is available at: https://youtu.be/HpvOvaIC1Z

Data-driven intelligent computational design for products: Method, techniques, and applications

Data-driven intelligent computational design (DICD) is a research hotspot emerged under the context of fast-developing artificial intelligence. It emphasizes on utilizing deep learning algorithms to extract and represent the design features hidden in historical or fabricated design process data, and then learn the combination and mapping patterns of these design features for the purposes of design solution retrieval, generation, optimization, evaluation, etc. Due to its capability of automatically and efficiently generating design solutions and thus supporting human-in-the-loop intelligent and innovative design activities, DICD has drawn the attentions from both academic and industrial fields. However, as an emerging research subject, there are still many unexplored issues that limit the development and application of DICD, such as specific dataset building, engineering design related feature engineering, systematic methods and techniques for DICD implementation in the entire product design process, etc. In this regard, a systematic and operable road map for DICD implementation from full-process perspective is established, including a general workflow for DICD project planning, an overall framework for DICD project implementation, the computing mechanisms for DICD implementation, key enabling technologies for detailed DICD implementation, and three application scenarios of DICD. The road map reveals the common mechanisms and calculation principles of existing DICD researches, and thus it can provide systematic guidance for the possible DICD applications that have not been explored

Optimization of Spiral MRI Using a Perceptual Difference Model

We systematically evaluated a variety of MR spiral imaging acquisition and reconstruction schemes using a computational perceptual difference model (PDM) that models the ability of humans to perceive a visual difference between a degraded “fast” MRI image with subsampling of k-space and a “gold standard” image mimicking full acquisition. Human subject experiments performed using a modified double-stimulus continuous-quality scale (DSCQS) correlated well with PDM, over a variety of images. In a smaller set of conditions, PDM scores agreed very well with human detectability measurements of image quality. Having validated the technique, PDM was used to systematically evaluate 2016 spiral image conditions (six interleave patterns, seven sampling densities, three density compensation schemes, four reconstruction methods, and four noise levels). Voronoi (VOR) with conventional regridding gave the best reconstructions. At a fixed sampling density, more interleaves gave better results. With noise present more interleaves and samples were desirable. With PDM, conditions were determined where equivalent image quality was obtained with 50% sampling in noise-free conditions. We conclude that PDM scoring provides an objective, useful tool for the assessment of fast MR image quality that can greatly aid the design of MR acquisition and signal processing strategies

General theory of Josephson Diodes

Motivated by recent progress in the superconductivity nonreciprocal phenomena, we study the general theory of Josephson diodes. The central ingredient for Josephson diodes is the asymmetric proximity process inside the tunneling barrier. From the symmetry breaking point of view, there are two types of Josephson diodes, inversion breaking and time-reversal breaking. For the inversion breaking case, applying voltage bias could effectively tune the proximity process like the voltage-dependent Rashba coupling or electric polarization giving rise to $I_c(V)\neq I_c(-V)$ and $I_{r+}\neq I_{r-}$. For the time-reversal breaking case, the current flow could adjust the internal time-reversal breaking field like magnetism or time-reversal breaking electron-electron pairing, which leads to $I_{c+}\neq I_{c-}$. All these results provide a complete understanding and the general principles of realizing Josephson diodes, especially the recently found NbSe$_2$/Nb$_3$Br$_8$/NbSe$_2$ Josephson diodes.Comment: 10 pages, 7 figures in main text with supplemental material, accepted in PR