63 research outputs found
POLAR3D: Augmenting NASA's POLAR Dataset for Data-Driven Lunar Perception and Rover Simulation
We report on an effort that led to POLAR3D, a set of digital assets that
enhance the POLAR dataset of stereo images generated by NASA to mimic lunar
lighting conditions. Our contributions are twofold. First, we have annotated
each photo in the POLAR dataset, providing approximately 23 000 labels for
rocks and their shadows. Second, we digitized several lunar terrain scenarios
available in the POLAR dataset. Specifically, by utilizing both the lunar
photos and the POLAR's LiDAR point clouds, we constructed detailed obj files
for all identifiable assets. POLAR3D is the set of digital assets comprising of
rock/shadow labels and obj files associated with the digital twins of lunar
terrain scenarios. This new dataset can be used for training perception
algorithms for lunar exploration and synthesizing photorealistic images beyond
the original POLAR collection. Likewise, the obj assets can be integrated into
simulation environments to facilitate realistic rover operations in a digital
twin of a POLAR scenario. POLAR3D is publicly available to aid perception
algorithm development, camera simulation efforts, and lunar simulation
exercises.POLAR3D is publicly available at
https://github.com/uwsbel/POLAR-digital.Comment: 7 pages, 4 figures; this work has been submitted to the 2024 IEEE
Conference on Robotics and Automation (ICRA) under revie
Analysis of carrier injection under high temperature AC operation in top gate IGZO TFTs
Abstractâ With the development of high-quality displays, metal oxides gradually become a popular active layer in TFTs [1]. In this work, InGaZnO thin film transistors with double-layer oxide are investigated. The oxide layer is divided into top and bottom layers. We improve the characteristics and reliability of the device through the design of double-layer oxide stack structure. The bottom oxide layer is deposited with a lower SiH4 flow rate, and the top oxide layer is deposited with a higher SiH4 flow rate. By increasing the SiH4 flow rate of the top oxide layer, two effects can be achieved. Firstly, it is beneficial for speeding up the film deposition process. Furthermore, the hydrogen residue passivates the dangling bonds in the oxide layer and increases the bonding amount of silanol groups, SiO-H, and achieve hydrogen channel doping [2]. By modulating the SiH4 flow rate of the top oxide layer, the basic characteristics of the devices and the reliability under alternating current (AC) operation are improved. In this work, we use three waveform types of switch process to analyze the degradation under AC stress, and the physic mechanism is proposed subsequently [3-4]. After AC stress, the top oxide layer with higher SiH4 flow rate has a smaller threshold voltage right shift, and the reliability is significantly improved.
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Edge-Termination and Core-Modification Effects of Hexagonal Nanosheet Graphene
[[abstract]]Optimized geometries and electronic structures of two different hexagonal grapheme nanosheets (HGNSs), with armchair (n-A-HGNS, n = 3â11) and zigzag (n-Z-HGNS, n = 1â8) edges have been calculated by using the GGA/PBE method implemented in the SIESTA package, with the DZP basis set, where n represents the number of peripheral rings. The computed HOMO-LUMO energy gap (Eg = ELUMO â EHOMO) decreases for fully H-terminated A- and Z-HGNSs with increasing n, i.e., with increasing nanosheet size and pÏ-orbitals being widely delocalized over the sheet surface. The full terminations, calculated with various functional groups, including the electron-withdrawing (F-, Cl-, and CN-) and -donating (OH-, and SH-) substitutions, were addressed. Significant lowering of EHOMO and ELUMO was obtained for CN-terminated HGNS as compared to those for H-terminated ones due to the mesomeric effect. The calculated Eg value decreases with increasing n for all terminations, whereby for the SH-termination in HGNS, the termination effect becomes less significant with increasing n. Further, the calculation results for stabilities of HGNS oxides support the tendency toward the oxidative reactivity at the edge site of the sheet, which shows most pronounced C-C bond length alternation, by chemical modification. Physical properties of HGNSs with various numbers of the core-defects, which can be obtained by strong oxidation, were also investigated. Their structures can change drastically from planar to saddle-like shapes. These conformations could be used as stationary phases with controlled interaction in the separation methods such as HPLC and the other chemical analysis techniques.[[notice]]èŁæŁćźçą[[incitationindex]]SCI[[booktype]]é»ć
Invited; Developing low-temperature defect passivation technology with supercritical fluid technology
Current technology nodes in the process of semiconductor manufacturing have faced many bottlenecks. Therefore, a disruptive-innovative semiconductor processing technology is crucially needed to make a significant breakthrough. Our research team has developed a low temperature (RT~250°C), defect passivation technology based on the supercritical fluid (SCF) technology applied in the nano-scale device processing to overcome the key issues. The SCF technology was originally applied in the field of the extraction and the cleaning of biotechnologies. However, our research team firstly applies this technology in the optoelectronic device. Compared to current high pressure annealing (HPA) and rapid thermal annealing (RTA) methods, the SCF-based defect passivation technology features low temperature, and can be applied for various materials and devices including photoelectric device, advanced nano-device, memory device, and wide bandgap device. Currently, the prototype of the 12â supercritical fluid processing equipment has already been built, and related recipes including nitridation, oxidation, hydrogenation, and sulfurization are also implemented for various devices and applications. In this talk, we will introduce related SCF defect passivation technology and future developments for the SCF applications
Reliability of flexible low temperature poly-silicon thin film transistor
This work reports the effect of mechanical stress-induced degradation in flexible low-temperature polycrystalline-silicon thin-film transistors. After 100,000 iterations of channel-width-direction mechanical compression at R=2mm, a significant shift of extracted threshold voltage and an abnormal hump at the subthreshold region were found. Simulation reveals that both the strongest mechanical stress and electrical field takes place at both sides of the channel edge, between the polycrystalline silicon and gate insulator. The gate insulator suffered from a serious mechanical stress and result in a defect generation in the gate insulator. The degradation of the threshold voltage shift and the abnormal hump can be ascribed to the electron trapping in these defects. In addition, this work introduced three methods to reduce the degradation cause by the mechanical stress, including the quality improvement of the gate insulator, organic trench structure and active layer with a wing structure.
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Modification of thermally activated delayed fluorescence emitters comprising acridanâ pyrimidine moieties for efficient sky-blue to greenish-blue OLEDs
Thermally activated delayed fluorescence (TADF) is a promising approach to harvest triplet excitons and achieve high-performance organic light-emitting diodes (OLEDs) for displays. In this study, we synthesized two new TADF emitters, 4Ac25CzPy and 4Ac35CzPy, featuring acridanâpyrimidineâcarbazole moieties. Remarkably, a slight modification in the carbazole group position enables precise control of luminous color, resulting in emissions at 483 nm and 494 nm for 4Ac25CzPy and 4Ac35CzPy, respectively, in the electroluminescent device. Both compounds exhibit small energy difference between their singlet and triplet states (DEST) of 0.14 eV and 0.15 eV, confirming their TADF characteristics. Notably, OLEDs utilizing 4Ac35CzPy achieve outstanding performance with the maximum external quantum efficiency (ZEQE) of 21.2% and a photoluminescence quantum yield of 65.1%. This high efficiency is attributed to efficient energy transfer from the host to the emitter. Moreover, the 4Ac35CzPy device exhibits a high light outcoupling efficiency of 0.3, further enhancing its remarkable performance
The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the extended Baryon Oscillation Spectroscopic Survey and from the second phase of the Apache Point Observatory Galactic Evolution Experiment
The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in
operation since July 2014. This paper describes the second data release from
this phase, and the fourteenth from SDSS overall (making this, Data Release
Fourteen or DR14). This release makes public data taken by SDSS-IV in its first
two years of operation (July 2014-2016). Like all previous SDSS releases, DR14
is cumulative, including the most recent reductions and calibrations of all
data taken by SDSS since the first phase began operations in 2000. New in DR14
is the first public release of data from the extended Baryon Oscillation
Spectroscopic Survey (eBOSS); the first data from the second phase of the
Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2),
including stellar parameter estimates from an innovative data driven machine
learning algorithm known as "The Cannon"; and almost twice as many data cubes
from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous
release (N = 2812 in total). This paper describes the location and format of
the publicly available data from SDSS-IV surveys. We provide references to the
important technical papers describing how these data have been taken (both
targeting and observation details) and processed for scientific use. The SDSS
website (www.sdss.org) has been updated for this release, and provides links to
data downloads, as well as tutorials and examples of data use. SDSS-IV is
planning to continue to collect astronomical data until 2020, and will be
followed by SDSS-V.Comment: SDSS-IV collaboration alphabetical author data release paper. DR14
happened on 31st July 2017. 19 pages, 5 figures. Accepted by ApJS on 28th Nov
2017 (this is the "post-print" and "post-proofs" version; minor corrections
only from v1, and most of errors found in proofs corrected
The 13th Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-IV Survey Mapping Nearby Galaxies at Apache Point Observatory
The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) began observations in July 2014. It pursues three core programs: APOGEE-2,MaNGA, and eBOSS. In addition, eBOSS contains two major subprograms: TDSS and SPIDERS. This paper describes the first data release from SDSS-IV, Data Release 13 (DR13), which contains new data, reanalysis of existing data sets and, like all SDSS data releases, is inclusive of previously released data. DR13 makes publicly available 1390 spatially resolved integral field unit observations of nearby galaxies from MaNGA,the first data released from this survey. It includes new observations from eBOSS, completing SEQUELS. In addition to targeting galaxies and quasars, SEQUELS also targeted variability-selected objects from TDSS and X-ray selected objects from SPIDERS. DR13 includes new reductions ofthe SDSS-III BOSS data, improving the spectrophotometric calibration and redshift classification. DR13 releases new reductions of the APOGEE-1data from SDSS-III, with abundances of elements not previously included and improved stellar parameters for dwarf stars and cooler stars. For the SDSS imaging data, DR13 provides new, more robust and precise photometric calibrations. Several value-added catalogs are being released in tandem with DR13, in particular target catalogs relevant for eBOSS, TDSS, and SPIDERS, and an updated red-clump catalog for APOGEE.This paper describes the location and format of the data now publicly available, as well as providing references to the important technical papers that describe the targeting, observing, and data reduction. The SDSS website, http://www.sdss.org, provides links to the data, tutorials and examples of data access, and extensive documentation of the reduction and analysis procedures. DR13 is the first of a scheduled set that will contain new data and analyses from the planned ~6-year operations of SDSS-IV.PostprintPeer reviewe
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