In microscopic image processing for analyzing biological objects, structural characters of objects such as symmetry and orientation can be used as a prior knowledge to improve the results. In this study, we incorporated filamentous local structures of neurons into a statistical model of image patches and then devised an image processing method based on tensor factorization with image patch rotation. Tensor factorization enabled us to incorporate correlation structure between neighboring pixels, and patch rotation helped us obtain image bases that well reproduce filamentous structures of neurons. We applied the proposed model to a microscopic image and found significant improvement in image restoration performance over existing methods, even with smaller number of bases. 相似文献
Abstract— In order to improve the reflective contrast ratio of transflective IPS‐LCDs, a novel pixel design for a normally white reflective IPS has been proposed. In this design, the large‐inter‐electrode‐spacing layout using a novel driving method and a double‐layered electrode have effectively reduced the light leakage. By applying these two technologies, a transflective IPS‐LCD has been successfully demonstrated with a high contrast ratio (15:1) in the reflective mode and a wide‐viewing‐angle characteristic in the transmissive mode. 相似文献
A tripod parallel mechanism consists of three links of fixed length and a rigid platform, and these are connected by revolute
joints. The platform can achieve sixdegrees-of-freedom (6-DOF) motion by the coordinated movement of the bottom ends of the
three links on a horizontal plane. This mechanism has advantages over the more common six extendible parallel manipulators.
It has a much larger work space and a simple structure. In this article, we show that the vector analysis for this tripod
parallel mechanism and the derivation of the positions of the three bottom ends of the links in an arbitrary attitude of platform
can be found by inverse kinematics and the conditions of geometrical constraint. Then, by a numerical simulation, the trajectories
of the bottom ends of the three links are shown. 相似文献
Epilepsy is a neurological disorder that may affect the autonomic nervous system (ANS) from 15 to 20 min before seizure onset, and disturbances of ANS affect R–R intervals (RRI) on an electrocardiogram (ECG). This study aims to develop a machine learning algorithm for predicting focal epileptic seizures by monitoring R–R interval (RRI) data in real time. The developed algorithm adopts a self-attentive autoencoder (SA-AE), which is a neural network for time-series data.
The results of applying the developed seizure prediction algorithm to clinical data demonstrated that it functioned well in most patients; however, false positives (FPs) occurred in specific participants. In a future work, we will investigate the causes of FPs and optimize the developing seizure prediction algorithm to further improve performance using newly added clinical data.
Nanocellulose is a sustainable and eco-friendly nanomaterial derived from renewable biomass.In this study,we utilized the structural advantages of two types of nanocellulose and fabricated freestanding carbonized hybrid nanocellulose films as electrode materials for supercapacitors.The long cellulose nanofibrils (CNFs) formed a macroporous framework,and the short cellulose nanocrystals were assembled around the CNF framework and generated micro/mesopores.This two-level hierarchical porous structure was successfully preserved during carbonization because of a thin atomic layer deposited (ALD) Al2O3 conformal coating,which effectively prevented the aggregation of nanocellulose.These carbonized,partially graphitized nanocellulose fibers were interconnected,forming an integrated and highly conductive network with a large specific surface area of 1,244 m2·g-1.The two-level hierarchical porous structure facilitated fast ion transport in the film.When tested as an electrode material with a high mass loading of 4 mg·cm-2 for supercapacitors,the hierarchical porous carbon film derived from hybrid nanocellulose exhibited a specific capacitance of 170 F.g-1and extraordinary performance at high current densities.Even at a very high current of 50 A·g-1,it retained 65% of its original specific capacitance,which makes it a promising electrode material for high-power applications. 相似文献
A solid-state drawing and winding process was done to create thin aligned carbon nanotube (CNT) sheets from CNT arrays. However, waviness and poor packing of CNTs in the sheets are two main weaknesses restricting their reinforcing efficiency in composites. This report proposes a simple press-drawing technique to reduce wavy CNTs and to enhance dense packing of CNTs in the sheets. Non-pressed and pressed CNT/epoxy composites were developed using prepreg processing with a vacuum-assisted system. Effects of pressing on the mechanical properties of the aligned CNT sheets and CNT/epoxy composites were examined. Pressing with distributed loads of 147, 221, and 294 N/m showed a substantial increase in the tensile strength and the elastic modulus of the aligned CNT sheets and their composites. The CNT sheets under a press load of 221 N/m exhibited the best mechanical properties found in this study. With a press load of 221 N/m, the pressed CNT sheet and its composite, respectively, enhanced the tensile strength by 139.1 and 141.9%, and the elastic modulus by 489 and 77.6% when compared with non-pressed ones. The pressed CNT/epoxy composites achieved high tensile strength (526.2 MPa) and elastic modulus (100.2 GPa). Results show that press-drawing is an important step to produce superior CNT sheets for development of high-performance CNT composites. 相似文献
Contact dynamics (CD) is a powerful method to solve the dynamics of large systems of colliding rigid bodies. CD can be computationally more efficient than classical penalty-based discrete element methods (DEM) for simulating contact between stiff materials such as rock, glass, or engineering metals. However, by idealizing bodies as perfectly rigid, contact forces computed by CD can be non-unique due to indeterminacy in the contact network, which is a common occurence in dense granular flows. We propose a frictionless CD method that is designed to identify only the unique set of contact forces that would be predicted by a soft particle method, such as DEM, in the limit of large stiffness. The method involves applying an elastic compatibility condition to the contact forces, which maintains no-penetration constraints but filters out force distributions that could not have arisen from stiff elastic contacts. The method can be used as a post-processing step that could be integrated into existing CD codes with minimal effort. We demonstrate its efficacy in a variety of indeterminate problems, including some involving multiple materials, non-spherical shapes, and nonlinear contact constitutive laws. 相似文献
Magnesium alloys are biodegradable metals receiving increasing attention, but the clinical applications of these materials are delayed by concerns over the rapid corrosion rate and gas formation. Unlike corrosion, which weakens mechanical properties, the gas formation issue has received little attention. Therefore, we evaluated the gas formation and biological effects for Mg implants through preclinical (immersed in Earle’s balanced salt solution and in vivo) and clinical studies. The immersion test examined the gas volume and composition. The in vivo study also examined gas volume and histological analysis. The clinical study examined the gas volume and safety after Mg screw metatarsal fixation. Gas was mainly composed of H2, CO and CO2. Maximum volumes of gas formed after 5 days for in vivo and 7 days in clinical study. Within the clinical examination, two superficial wound complications healed with local wound care. Osteolytic lesions in the surrounding metaphysis of the Mg screw insertion developed in all cases and union occurred at 3 months. Mg implants released gas with variable volumes and composition (H2, CO, and CO2), with no long-term toxic effects on the surrounding tissue. The implants enabled bone healing, although complications of wound breakdown and osteolytic lesions developed. 相似文献