AADS: Augmented autonomous driving simulation using data-driven algorithms.

Simulation systems have become essential to the development and validation of autonomous driving (AD) technologies. The prevailing state-of-the-art approach for simulation uses game engines or high-fidelity computer graphics (CG) models to create driving scenarios. However, creating CG models and vehicle movements (the assets for simulation) remain manual tasks that can be costly and time consuming. In addition, CG images still lack the richness and authenticity of real-world images, and using CG images for training leads to degraded performance. Here, we present our augmented autonomous driving simulation (AADS). Our formulation augmented real-world pictures with a simulated traffic flow to create photorealistic simulation images and renderings. More specifically, we used LiDAR and cameras to scan street scenes. From the acquired trajectory data, we generated plausible traffic flows for cars and pedestrians and composed them into the background. The composite images could be resynthesized with different viewpoints and sensor models (camera or LiDAR). The resulting images are photorealistic, fully annotated, and ready for training and testing of AD systems from perception to planning. We explain our system design and validate our algorithms with a number of AD tasks from detection to segmentation and predictions. Compared with traditional approaches, our method offers scalability and realism. Scalability is particularly important for AD simulations, and we believe that real-world complexity and diversity cannot be realistically captured in a virtual environment. Our augmented approach combines the flexibility of a virtual environment (e.g., vehicle movements) with the richness of the real world to allow effective simulation.

Large-scale continuous-variable dual-rail cluster entangled state based on spatial mode comb.

In recent continuous-variable (CV) multipartite entanglement researches, the number of fully inseparable light modes has been increased dramatically by the introduction of a multiplexing scheme in either the time domain or the frequency domain. In this paper, we propose a scheme that a large-scale (≥ 20) CV dual-rail cluster entangled state is established based on a spatial mode comb in a self-imaging optical parametric oscillator, which is pumped by two spatial Laguerre-Gaussian modes with different polarization and identical frequency. A sufficient condition of full inseparability for a CV dual-rail cluster entangled state is used to evaluate the degree of quantum entanglement. It is shown that entanglement exists over a wide range of analyzing frequency and pump parameter. We have found a new scheme that uses the optical parametric cavity to generate a large-scale entanglement based on optical spatial mode comb. The presented system will be hopefully as a practical entangled source for quantum information.

Scheme for efficient extraction of low-frequency signal beyond the quantum limit by frequency-shift detection.

Low-frequency (Hz~kHz) squeezing is very important in many schemes of quantum precision measurement. But it is more difficult than that at megahertz-frequency because of the introduction of laser low-frequency technical noise. In this paper, we propose a scheme to obtain a low-frequency signal beyond the quantum limit from the frequency comb in a non-degenerate frequency and degenerate polarization optical parametric amplifier (NOPA) operating below threshold with type I phase matching by frequency-shift detection. Low-frequency squeezing immune to laser technical noise is obtained by a detection system with a local beam of two-frequency intense laser. Furthermore, the low-frequency squeezing can be used for phase measurement in Mach-Zehnder interferometer, and the signal-to-noise ratio (SNR) can be enhanced greatly.

Gate dependent photo-responses of carbon nanotube field effect phototransistors.

Gate dependent photoconductivity of carbon nanotube (CNT) field effect phototransistors (FEPs) was systematically investigated in this study. The photo-response comparisons of CNT FEPs with symmetric and asymmetric metal structures connecting to the same CNT revealed that the gate effect contributed to a sensitivity improvement with a lower dark current, a higher photocurrent, and an enhanced photovoltage. A functionalized asymmetric FEP, fabricated by partially doping the CNT utilizing a polyethylene imine (PEI) polymer, verified that FEPs delivered a better performance by using asymmetric structures. A multi-gate FEP, with three pairs of side-gates that can electrostatically dope different sections of a CNT independently, was fabricated to examine the gate structure dependent photo-responses. Experimental measurements showed an unconventional photocurrent improvement that was weakly dependent on the gate location, which was attributed to the unique charge distribution of one-dimensional semiconductors.

Taxonomic study of the genus Eucriotettix hebard (Orthoptera: Tetrigidea) from China.

The genus Eucriotettix Hebard from China was reviewed and 13 were species recorded, including two new species: Eucriotettix nigripennis Deng & Zheng n. sp. and Eucriotettix strictivertex Deng & Zheng n. sp. A key to the species of Eucriotettix from China is provided. Type specimens were deposited in the Institute of Zoology, Shaanxi Normal University.

Al2O3 and TiO2 atomic layer deposition on copper for water corrosion resistance.

Al(2)O(3) and TiO(2) atomic layer deposition (ALD) were employed to develop an ultrathin barrier film on copper to prevent water corrosion. The strategy was to utilize Al(2)O(3) ALD as a pinhole-free barrier and to protect the Al(2)O(3) ALD using TiO(2) ALD. An initial set of experiments was performed at 177 °C to establish that Al(2)O(3) ALD could nucleate on copper and produce a high-quality Al(2)O(3) film. In situ quartz crystal microbalance (QCM) measurements verified that Al(2)O(3) ALD nucleated and grew efficiently on copper-plated quartz crystals at 177 °C using trimethylaluminum (TMA) and water as the reactants. An electroplating technique also established that the Al(2)O(3) ALD films had a low defect density. A second set of experiments was performed for ALD at 120 °C to study the ability of ALD films to prevent copper corrosion. These experiments revealed that an Al(2)O(3) ALD film alone was insufficient to prevent copper corrosion because of the dissolution of the Al(2)O(3) film in water. Subsequently, TiO(2) ALD was explored on copper at 120 °C using TiCl(4) and water as the reactants. The resulting TiO(2) films also did not prevent the water corrosion of copper. Fortunately, Al(2)O(3) films with a TiO(2) capping layer were much more resilient to dissolution in water and prevented the water corrosion of copper. Optical microscopy images revealed that TiO(2) capping layers as thin as 200 Å on Al(2)O(3) adhesion layers could prevent copper corrosion in water at 90 °C for ~80 days. In contrast, the copper corroded almost immediately in water at 90 °C for Al(2)O(3) and ZnO films by themselves on copper. Ellipsometer measurements revealed that Al(2)O(3) films with a thickness of ~200 Å and ZnO films with a thickness of ~250 Å dissolved in water at 90 °C in ~10 days. In contrast, the ellipsometer measurements confirmed that the TiO(2) capping layers with thicknesses of ~200 Å on the Al(2)O(3) adhesion layers protected the copper for ~80 days in water at 90 °C. The TiO(2) ALD coatings were also hydrophilic and facilitated H(2)O wetting to copper wire mesh substrates.

[The compensatory changes of unstriped muscles of portal vein and superior mesenteric artery in rabbits infected with schistosomiasis].

We observed the changes of unstriped muscle of portal vein and superior mesenteric artery in rabbits infected with schistosomiasis in different stages with Masson trichrome stain. The results showed compensatory hypertrophy and hyperplasia of unstriped muscle of internal and medial layer of portal vein and superior mesenteric artery. It is concluded that the portal system is volume vessel as well as resistance vessel, which can counteract the intrahepatic resistance, maintaining the liver blood flow supply. The hyperdynamic circulation of viscera contributes to elevation of constrict power of the superior mesenteric artery, resulting in compensatory hypertrophy and hyperplasia of the unstriped muscle.