196 research outputs found
AST-GIN: Attribute-Augmented Spatial-Temporal Graph Informer Network for Electric Vehicle Charging Station Availability Forecasting
Electric Vehicle (EV) charging demand and charging station availability
forecasting is one of the challenges in the intelligent transportation system.
With the accurate EV station situation prediction, suitable charging behaviors
could be scheduled in advance to relieve range anxiety. Many existing deep
learning methods are proposed to address this issue, however, due to the
complex road network structure and comprehensive external factors, such as
point of interests (POIs) and weather effects, many commonly used algorithms
could just extract the historical usage information without considering
comprehensive influence of external factors. To enhance the prediction accuracy
and interpretability, the Attribute-Augmented Spatial-Temporal Graph Informer
(AST-GIN) structure is proposed in this study by combining the Graph
Convolutional Network (GCN) layer and the Informer layer to extract both
external and internal spatial-temporal dependence of relevant transportation
data. And the external factors are modeled as dynamic attributes by the
attribute-augmented encoder for training. AST-GIN model is tested on the data
collected in Dundee City and experimental results show the effectiveness of our
model considering external factors influence over various horizon settings
compared with other baselines.Comment: 10 pages; 17 figures; Under review for IEEE Transaction on Vehicular
Technolog
Optimal frequency for vibrational optical coherence elastography (OCE) on tissue mechanical properties characterization
Profound Presentation of Retinopathy in a Patient with Sickle Cell trait and Diabetes Mellitus
This is a Photo Essay and does not have an abstract
Visualizing choriocapillaris using swept source optical coherence tomography angiography with various probe beam sizes
Imaging choriocapillaris (CC) is a long-term challenge for commercial OCT angiography (OCTA) systems due to limited transverse resolution. Effects of transverse resolution on the visualization of a CC microvascular network are explored and demonstrated in this paper. We use three probe beams with sizes of ~1.12 mm, ~2.51 mm and ~3.50 mm at the pupil plane, which deliver an estimated transverse resolution at the retina of 17.5 µm, 8.8 µm and 7.0 µm, respectively, to investigate the ability of OCTA to resolve the CC capillary vessels. The complex optical microangiography algorithm is applied to extract blood flow in the CC slab. Mean retinal pigment epithelium (RPE) to CC (RPE-CC) distance, mean CC inter-vascular spacing and the magnitude in the radially-averaged power spectrum are quantified. We demonstrate that a clearer CC lobular capillary network is resolved in the angiograms provided by a larger beam size. The image contrast of the CC angiogram with a large beam size of 3.50 mm is 114% higher than that with a small beam size of 1.12 mm. While the measurements of the mean RPE-CC distance and CC inter-vascular spacing are almost consistent regardless of the beam sizes, they are more reliable and stable with the larger beam size of 3.50 mm. We conclude that the beam size is a key parameter for CC angiography if the purpose of the investigation is to visualize the individual CC capillaries.</p
Розробка модуля Ethernet контролю для дистанційного керування електроживильною установкою
Sound processing in the inner ear involves separation of the constituent frequencies along the length of the cochlea. Frequencies relevant to human speech (100 to 500 Hz) are processed in the apex region. Among mammals, the guinea pig cochlear apex processes similar frequencies and is thus relevant for the study of speech processing in the cochlea. However, the requirement for extensive surgery has challenged the optical accessibility of this area to investigate cochlear processing of signals without significant intrusion. A simple method is developed to provide optical access to the guinea pig cochlear apex in two directions with minimal surgery. Furthermore, all prior vibration measurements in the guinea pig apex involved opening an observation hole in the otic capsule, which has been questioned on the basis of the resulting changes to cochlear hydrodynamics. Here, this limitation is overcome by measuring the vibrations through the unopened otic capsule using phase-sensitive Fourier domain optical coherence tomography. The optically and surgically advanced method described here lays the foundation to perform minimally invasive investigation of speech-related signal processing in the cochlea. (C) The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License.Funding Agencies|NIH NIDCD [R01DC000141]; NIH [R01DC004554, R01DC010201, R01DC011796]; Swedish Research Council [K2014-63X-14061-14-5]; Torsten Soderberg Foundation</p
High-Power AlGaInAs/InP DFB Lasers with Low Divergence Angle
High-power semiconductor DFB lasers with low divergence angle fundamental transverse mode operating at wavelengths near 1.31 μm have many applications such as analog and digital fiber communication, WDM pump sources, spectroscopy, remote sensing, free-space communication, laser-based radar, and wavelength conversion in nonlinear materials [1]. These devices can potentially reduce system costs by simplifying optical alignment and package processes [2]. Devices with narrow far-field patterns (FFPs) are highly desirable for simple, high-yield optical alignment, as a low divergence angle improves the coupling efficiency and imposes less stringent tolerances in the alignment between the device and the single-mode fiber (SMF). Until now most of the high-power low divergence angle 1.31 μm DFB laser is based on InGaAsP/InP material system which has lower characteristic temperature value T 0 [3]. Here we first demonstrate the high-power fundamental transverse mode 1.31 μm AlGaInAs/InP DFB laser with low divergence angle, enabling uncooled continuous-wave (CW) operation at high ambient temperatures
Regrowth-free AlGaInAs MQW polarization controller integrated with sidewall grating DFB laser
We report an AlGaInAs multiple quantum well integrated source of polarization
controlled light consisting of a polarization mode converter PMC, differential
phase shifter(DPS), and a side wall grating distributed-feedback DFB laser. We
demonstrate an asymmetrical stepped-height ridge waveguide PMC to realize TE to
TM polarization conversion and a symmetrical straight waveguide DPS to enable
polarization rotation from approximately counterclockwise circular polarization
to linear polarization. Based on the identical epitaxial layer scheme, all of
the PMC, DPS, and DFB laser can be integrated monolithically using only a
single step of metalorganic vapor phase epitaxy and two steps of III V material
dry etching. For the DFB-PMC device, a high TE to TM polarization conversion
efficiency 98% over a wide range of DFB injection currents is reported at 1555
nm wavelength. For the DFB-PMC-DPS device, a 60 degree rotation of the Stokes
vector was obtained on the Poincar\'e sphere with a range of bias voltage from
0 V to -4.0 V at IDFB is 170 mA.Comment: arXiv admin note: text overlap with arXiv:2210.1051
Stepped-height ridge waveguide MQW polarization mode converter monolithically integrated with sidewall grating DFB laser
We report the first demonstration of a 1555 nm stepped-height ridge waveguide
polarization mode converter monolithically integrated with a side wall grating
distributed-feedback (DFB) laser using the identical epitaxial layer scheme.
The device shows stable single longitudinal mode (SLM) operation with the
output light converted from TE to TM polarization with an efficiency of >94%
over a wide range of DFB injection currents (IDFB) from 140 mA to 190 mA. The
highest TM mode purity of 98.2% was obtained at IDFB=180 mA. A particular
advantage of this device is that only a single step of metalorganic vapor-phase
epitaxy and two steps of III-V material dry etching are required for the whole
integrated device fabrication, significantly reducing complexity and cost
Longitudinal correlation of 3d OCT to detect early stage erosion in bovine enamel
Biotechnology and Biological Sciences Research Council (BBSRC) (BB/K501190/1)
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