Realizing the Nishimori transition across the error threshold for constant-depth quantum circuits

Preparing quantum states across many qubits is necessary to unlock the full potential of quantum computers. However, a key challenge is to realize efficient preparation protocols which are stable to noise and gate imperfections. Here, using a measurement-based protocol on a 127 superconducting qubit device, we study the generation of the simplest long-range order -- Ising order, familiar from Greenberger-Horne-Zeilinger (GHZ) states and the repetition code -- on 54 system qubits. Our efficient implementation of the constant-depth protocol and classical decoder shows higher fidelities for GHZ states compared to size-dependent, unitary protocols. By experimentally tuning coherent and incoherent error rates, we demonstrate stability of this decoded long-range order in two spatial dimensions, up to a critical point which corresponds to a transition belonging to the unusual Nishimori universality class. Although in classical systems Nishimori physics requires fine-tuning multiple parameters, here it arises as a direct result of the Born rule for measurement probabilities -- locking the effective temperature and disorder driving this transition. Our study exemplifies how measurement-based state preparation can be meaningfully explored on quantum processors beyond a hundred qubits.Comment: 16 pages, 18 figure

Implantable and Biodegradable Macroporous Iron Oxide Frameworks for Efficient Regeneration and Repair of Infracted Heart

The construction, characterization and surgical application of a multilayered iron oxide-based macroporous composite framework were reported in this study. The framework consisted of a highly porous iron oxide core, a gelatin-based hydrogel intermediary layer and a matrigel outer cover, which conferred a multitude of desirable properties including excellent biocompatibility, improved mechanical strength and controlled biodegradability. The large pore sizes and high extent of pore interconnectivity of the framework stimulated robust neovascularization and resulted in substantially better cell viability and proliferation as a result of improved transport efficiency for oxygen and nutrients. In addition, rat models with myocardial infraction showed sustained heart tissue regeneration over the infract region and significant improvement of cardiac functions following the surgical implantation of the framework. These results demonstrated that the current framework might hold great potential for cardiac repair in patients with myocardial infraction

Proceedings of the 29th EG-ICE International Workshop on Intelligent Computing in Engineering

This publication is the Proceedings of the 29th EG-ICE International Workshop on Intelligent Computing in Engineering from July 6-8, 2022. The EG-ICE International Workshop on Intelligent Computing in Engineering brings together international experts working on the interface between advanced computing and modern engineering challenges. Many engineering tasks require open-world resolution of challenges such as supporting multi-actor collaboration, coping with approximate models, providing effective engineer-computer interaction, search in multi-dimensional solution spaces, accommodating uncertainty, including specialist domain knowledge, performing sensor-data interpretation and dealing with incomplete knowledge. While results from computer science provide much initial support for resolution, adaptation is unavoidable and most importantly, feedback from addressing engineering challenges drives fundamental computer-science research. Competence and knowledge transfer goes both ways. &nbsp

Proceedings of the 29th EG-ICE International Workshop on Intelligent Computing in Engineering

This publication is the Proceedings of the 29th EG-ICE International Workshop on Intelligent Computing in Engineering from July 6-8, 2022. The EG-ICE International Workshop on Intelligent Computing in Engineering brings together international experts working on the interface between advanced computing and modern engineering challenges. Many engineering tasks require open-world resolution of challenges such as supporting multi-actor collaboration, coping with approximate models, providing effective engineer-computer interaction, search in multi-dimensional solution spaces, accommodating uncertainty, including specialist domain knowledge, performing sensor-data interpretation and dealing with incomplete knowledge. While results from computer science provide much initial support for resolution, adaptation is unavoidable and most importantly, feedback from addressing engineering challenges drives fundamental computer-science research. Competence and knowledge transfer goes both ways. &nbsp

A front-tracking solidification model and its application in modelling alloy solidification

A front-tracking solidification model has been developed to simulate the dendritic structure evolution during alloy solidification. In the model the growth of dendrites is governed by heat and mass transport and a finite difference technique is employed to solve heat and solute diffusion during solidification. The model incorporates front-tracking technique to calculate and track the exact position of the Solid/Liquid (S/L) interface as a part of solution process and a new capture rule was designed and implemented in the model to efficiently track the growing S/L interface. The model has been evaluated and verified using simulated data from Al-Cu 4 wt. % alloy solidification. The effect of curvature undercooling on crystal growth was investigated. The simulated results reveal that solute redistribution, curvature of the S/L interface and anisotropy of interface tension are important factors in determining the dendritic morphology. The calculation of the S/L interface curvature and anisotropy of surface tension was found to be particularly important in determining the dendritic growth direction. Based on the above observations and simulated data, the parameters in the developed model have been optimised for predicting the solidification structure in binary alloys. Simulations of Al-Cu alloy solidification were then performed using the optimised model for single-grain and multi-grain solidification. The simulated results of single-grain growth were compared with the results from the Lipton-Glicksman-Kurz (LGK) model (Lipton et al. 1984). Solute profile ahead of the S/L interface was examined using different techniques for approximating solute profile in the growing cell. The solidification segregation in the multi-grain growth was investigated; and the dendritic evolution and solute interaction during multi-grain growth were investigated

High-Quality, Real-Time HD Video Stereo Matching on FPGA -- Circuits and Systems

info:eu-repo/semantics/nonPublishe

On the Aging Behavior of Ti-1.0 wt pct Fe Alloy With an Equiaxed α + β Initial Microstructure

The aging behavior (300 °C to 700 °C) of Ti-1.0 wt pct Fe alloy was investigated in this study, by means of various microstructural characterization techniques and micromechanical testing methods. The initial microstructure consisted of equiaxed α and β grains as well as athermal ω precipitates (ωath) with several tens of nanometers inside β grains. During the aging process, significant microstructural modifications took place within the β grains. At relatively lower aging temperatures (300 °C to 500 °C), the volume fraction of ωath gradually decreased with increasing aging temperature, until they were totally replaced by secondary α precipitates (αs) at 500 °C. With further increase of the aging temperature (500 °C ~ 700 °C), the size of αs precipitates substantially increased while the volume fraction gradually decreased, indicating a partial α to β reverse phase transformation. At aging temperatures higher than 600 °C, the re-precipitation of ωath from reverse-transformed β phase during water quench was identified. Due to an extremely high Fe concentration of these ωath that inherited from reverse-transformed β phase, their lattice constants were much smaller than those in the initial microstructure. The existence of ωath inside β phase promoted a homogeneous precipitation behavior of αs precipitates during aging, by providing much more potential intragranular nucleation sites. This led to the formation of plate-shaped αs precipitates with multiple crystallographic variants, in sharp contrast to the conventional α lamellar/colony structure with limited crystallographic variants obtained by thermomechanical processing in which αs precipitates directly transformed from β phase. Moreover, it was also revealed that the transformation of nano-sized ωath into αs precipitates as well as their subsequent coarsening led to a continuous decrease of the nano-hardness of prior β areas

Vision-based adaptive neural positioning control of quadrotor aerial robot

In this paper, a new vision-based adaptive control algorithm is proposed for the positioning of a quadrotor aerial robot (QAR) with an onboard pin-hole camera. First, the transformation between the position tracking error and image projection error is constructed through the spherical projection method, and then the regulation of the position error is achieved indirectly by stabilizing the image projection error. To overcome the challenge that the dynamics of QAR is physically underactuated, a backstepping-based approach that synthesizes the Lipschitz condition and natural saturation of the inverse tangent function is proposed. In the proposed adaptive controller, an optimized adaptive neural network (NN) means is designed, where only the square of the NN weight matrix's maximum singular value, not the weight matrix itself, is estimated. Moreover, to facilitate practical application, a novel inertial matrix estimator is introduced in the tuning laws, so that the accurate QAR rotation inertial information is not required. By Lyapunov theory, it is proved that the image projection error converges to an adjustable region of zero asymptotically. The effectiveness of the proposed algorithm has been confirmed by the experimental results.Published versio

Design and Kinematic Analysis of a Novel Planar Parallel Robot With Pure Translations

The structural synthesis of a group of parallel mechanisms can be established by an exhaustive enumeration of all feasible kinematic chains based on the screw theory. However, reliable kinematic limbs can provide mobility constraints for some unqualified supporting legs to guarantee the degrees-of-freedom feasibility of the parallel robots. A systematic design approach is presented for a family of planar single-loop parallel mechanisms with the consideration of infeasible kinematic chains. Different from the other design approaches for single-loop linkages, the fixed and moving platforms are predefined in this research to distinguish different kinematic limbs. The special parallelogram linkage mechanism is incorporated due to its equivalent translation capacity. Three categories of singularity configurations are investigated based on the detailed kinematic models. The reachable workspace is obtained through the spatial search methodology. Several novel kinematic error model associated performance indices are proposed in this work and examined on a translational parallel manipulator. Experiments are carried out and compared to testify the effectiveness of the kinematic analysis and proposed position-based controller

Effect of Recycled Shell Waste as a Modifier on the High- and Low-Temperature Rheological Properties of Asphalt

The deteriorating ecological environment and the concept of sustainable development have highlighted the importance of waste reuse. This article investigates the performance changes resulting from the incorporation of shellac into asphalt binders. Seashell powder-modified asphalt was prepared with 5%, 10%, and 15% admixture using the high-speed shear method. The microstructure of the seashell powder was observed by scanning electron microscope test (SEM); the physical-phase analysis of the seashell powder was carried out using an X-ray diffraction (XRD) test; the surface characteristics and pore structure of shellac were analyzed by the specific surface area Brunauer-Emmett-Teller (BET) test; and Fourier infrared spectroscopy (FTIR) qualitatively analyzed the composition and changes of functional groups of seashell powder-modified asphalt. The conventional performance index of seashell powder asphalt was analyzed by penetration, softening point, and ductility (5 °C) tests; the effect of seashell powder on asphalt binder was studied using a dynamic shear rheometer (DSR) and bending beam rheometer (BBR) at high and low temperatures, respectively. The results indicate the following: seashell powder is a coarse, porous, and angular CaCO3 bio-material; seashell powder and the asphalt binder represent a stable physical mixture of modified properties; seashell powder improves the consistency, hardness, and high-temperature performance of the asphalt binder but weakens the low-temperature performance of it; seashell powder enhances the elasticity, recovery performance, and permanent deformation resistance of asphalt binders and improves high-temperature rheological properties; finally, seashell powder has a minimal effect on the crack resistance of asphalt binders at very low temperatures. In summary, the use of waste seashells for recycling as bio-modifiers for asphalt binders is a practical approach