221 research outputs found
Saliency difference based objective evaluation method for a superimposed screen of the HUD with various background
The head-up display (HUD) is an emerging device which can project information
on a transparent screen. The HUD has been used in airplanes and vehicles, and
it is usually placed in front of the operator's view. In the case of the
vehicle, the driver can see not only various information on the HUD but also
the backgrounds (driving environment) through the HUD. However, the projected
information on the HUD may interfere with the colors in the background because
the HUD is transparent. For example, a red message on the HUD will be less
noticeable when there is an overlap between it and the red brake light from the
front vehicle. As the first step to solve this issue, how to evaluate the
mutual interference between the information on the HUD and backgrounds is
important. Therefore, this paper proposes a method to evaluate the mutual
interference based on saliency. It can be evaluated by comparing the HUD part
cut from a saliency map of a measured image with the HUD image.Comment: 10 pages, 5 fighres, 1 table, accepted by IFAC-HMS 201
Development of a Nongenetic Mouse Model of Type 2 Diabetes
Insulin resistance and loss of β-cell mass cause Type 2 diabetes (T2D). The objective of this study was to generate a nongenetic mouse model of T2D. Ninety-six 6-month-old C57BL/6N males were assigned to 1 of 12 groups including (1) low-fat diet (LFD; low-fat control; LFC), (2) LFD with 1 i.p. 40 mg/kg BW streptozotocin (STZ) injection, (3), (4), (5), (6) LFD with 2, 3, 4, or 5 STZ injections on consecutive days, respectively, (7) high-fat diet (HFD), (8) HFD with 1 STZ injection, (9), (10), (11), (12) HFD with 2, 3, 4, or 5 STZ injections on consecutive days, respectively. After 4 weeks, serum insulin levels were reduced in HFD mice administered at least 2 STZ injections as compared with HFC. Glucose tolerance was impaired in mice that consumed HFD and received 2, 3, or 4 injections of STZ. Insulin sensitivity in HFD mice was lower than that of LFD mice, regardless of STZ treatment. Islet mass was not affected by diet but was reduced by 50% in mice that received 3 STZ injections. The combination of HFD and three 40 mg/kg STZ injections induced a model with metabolic characteristics of T2D, including peripheral insulin resistance and reduced β-cell mass
Photoconductivity of Single-crystalline Selenium Nanotubes
Photoconductivity of single-crystalline selenium nanotubes (SCSNT) under a
range of illumination intensities of a 633nm laser is carried out with a novel
two terminal device arrangement at room temperature. It's found that SCSNT
forms Schottky barriers with the W and Au contacts, and the barrier height is a
function of the light intensities. In low illumination regime below 1.46x10E-4
muWmum-2, the Au-Se-W hybrid structure exhibits sharp switch on/off behavior,
and the turn-on voltages decrease with increasing illuminating intensities. In
the high illumination regime above 7x10E-4 muWmum-2, the device exhibits ohmic
conductance with a photoconductivity as high as 0.59Ohmcm-1, significantly
higher that reported values for carbon and GaN nanotubes. This finding suggests
that SCSNT is potentially a good photo-sensor material as well we a very
effective solar cell material.Comment: 12pages including 5 figures, submitted to Nanotechnolog
Concurrent optimisation of structural topology and fibre paths for 3D printing of continuous fibre composites based on chain primitive projection
This study proposes a novel topology optimisation method based on the Geometry Projection Topology Optimisation method (GPTO) with the consideration of manufacturing constraints for the 3D printing of continuous fibre reinforced polymer composite structures. The proposed method uses connecting bars in chains to represent the continuous fibre filaments in the composite structure, as opposed to the use of separate bars as primitives. Thus, the method is termed as Chain Projection Topology Optimisation (CPTO), in which the chain-like primitives are equivalent to clusters of real printing paths. The 3D printing paths can be acquired by splitting the primitives evenly, which simplified the printing path design procedure to a great extent. In addition, manufacturing constraints can be easily imposed on the primitives, making it superior to density-based topology optimisation methods. An MBB beam, a cantilever beam, and a bridge case are optimised to demonstrate the CPTO’s efficiency. It was found that the designs by CPTO possess comparable mechanical properties when compared to those by the Solid Orthotropic Material Penalization (SOMP) method while guaranteeing the composite structures are suitable for 3D printing and contain less microscopic defects in the printed fibre filaments
Dietary Anti-Aging Polyphenols and Potential Mechanisms
For years, the consumption of a diet rich in fruits and vegetables has been considered healthy, increasing longevity, and decreasing morbidities. With the assistance of basic research investigating the potential mechanisms, it has become clear that the beneficial effects of plant-based foods are mainly due to the large amount of bioactive phenolic compounds contained. Indeed, substantial dietary intervention studies in humans have supported that the supplementation of polyphenols have various health-promoting effects, especially in the elderly population. In vitro examinations on the anti-aging mechanisms of polyphenols have been widely performed, using different types of natural and synthetic phenolic compounds. The aim of this review is to critically evaluate the experimental evidence demonstrating the beneficial effects of polyphenols on aging-related diseases. We highlight the potential anti-aging mechanisms of polyphenols, including antioxidant signaling, preventing cellular senescence, targeting microRNA, influencing NO bioavailability, and promoting mitochondrial function. While the trends on utilizing polyphenols in preventing aging-related disorders are getting growing attention, we suggest the exploration of the beneficial effects of the combination of multiple polyphenols or polyphenol-rich foods, as this would be more physiologically relevant to daily lif
Electron Density Dependence of in-plane Spin Relaxation Anisotropy in GaAs/AlGaAs Two-Dimensional Electron Gas
We investigated the spin dynamics of two-dimensional electrons in (001)
GaAs/AlGaAs heterostructure using the time resolved Kerr rotation technique
under a transverse magnetic field. The in-plane spin lifetime is found to be
anisotropic below 150k due to the interference of Rashba and Dresselhaus
spin-orbit coupling and D'yakonov-Perel' spin relaxation. The ratio of in-plane
spin lifetimes is measured directly as a function of temperature and pump
power, showing that the electron density in 2DEG channel strongly affects the
Rashba spin-orbit coupling.Comment: 3 pages, 2 figure
Age-induced oxidative stress: how does it influence skeletal muscle quantity and quality?
With advancing age, skeletal muscle function declines as a result of strength loss. These strength deficits are largely due to reductions in muscle size (i.e., quantity) and its intrinsic force-producing capacity (i.e., quality). Age-induced reductions in skeletal muscle quantity and quality can be the consequence of several factors, including accumulation of reactive oxygen and nitrogen species (ROS/RNS), also known as oxidative stress. Therefore, the purpose of this mini-review is to highlight the published literature that has demonstrated links between aging, oxidative stress, and skeletal muscle quantity or quality. In particular, we focused on how oxidative stress has the potential to reduce muscle quantity by shifting protein balance in a deficit, and muscle quality by impairing activation at the neuromuscular junction, excitation-contraction (EC) coupling at the ryanodine receptor (RyR), and cross-bridge cycling within the myofibrillar apparatus. Of these, muscle weakness due to EC coupling failure mediated by RyR dysfunction via oxidation and/or nitrosylation appears to be the strongest candidate based on the publications reviewed. However, it is clear that age-associated oxidative stress has the ability to alter strength through several mechanisms and at various locations of the muscle fiber.T32 AG029796 - NIA NIH HHSPublished versio
A modified equally-spaced method (MEQS) for fibre placement in additive manufacturing of topology-optimised continuous carbon fibre-reinforced polymer composite structures
This study proposes a modified equally-spaced (MEQS) method for the path design of continuous fibres in additive manufacturing (AM) of topologically optimised composite structures. The MEQS method addresses the low fibre infill rate issue of the traditional Equally-Spaced (EQS) method by utilising the Offset method to generate looped printing paths around the internal cavities and gaps between continuous fibre paths. The developed MEQS method was first illustrated against EQS and Offset methods using an open-hole composite plate in which topology and material orientation were simultaneously optimised using the discrete–continuous parameterisation (DCP) method. Actual printing path-based finite element modelling showed that the MEQS method achieves a 25.32% increase in stiffness compared to the Offset method. Experimental testing of the additively manufactured open-hole composite plates showed that the MEQS method improves the stiffness and strength by 15.52% and 27.38%, respectively, compared to the Offset method. The proposed MEQS was further demonstrated through two other case studies by finite element modelling, showing that the stiffness of MEQS has increased by an average of 66.71% and 14.95% compared to EQS and Offset, respectively
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