3,118 research outputs found

    1-(4-Methyl­benzyl­ideneamino)pyridinium iodide

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    The title compound, C13H13N2 +·I−, is a derivative of 1-amino­pyridinium iodide. The pyridine and benzene rings are oriented at a dihedral angle of 45.78 (3)°. In the crystal structure, weak inter­molecular C—H⋯I hydrogen bonds link the mol­ecules

    Ansor : Generating High-Performance Tensor Programs for Deep Learning

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    High-performance tensor programs are crucial to guarantee efficient execution of deep neural networks. However, obtaining performant tensor programs for different operators on various hardware platforms is notoriously challenging. Currently, deep learning systems rely on vendor-provided kernel libraries or various search strategies to get performant tensor programs. These approaches either require significant engineering effort to develop platform-specific optimization code or fall short of finding high-performance programs due to restricted search space and ineffective exploration strategy. We present Ansor, a tensor program generation framework for deep learning applications. Compared with existing search strategies, Ansor explores many more optimization combinations by sampling programs from a hierarchical representation of the search space. Ansor then fine-tunes the sampled programs with evolutionary search and a learned cost model to identify the best programs. Ansor can find high-performance programs that are outside the search space of existing state-of-the-art approaches. In addition, Ansor utilizes a task scheduler to simultaneously optimize multiple subgraphs in deep neural networks. We show that Ansor improves the execution performance of deep neural networks relative to the state-of-the-art on the Intel CPU, ARM CPU, and NVIDIA GPU by up to 3.8×3.8\times, 2.6×2.6\times, and 1.7×1.7\times, respectively.Comment: Published in OSDI 202

    Urban traffic density estimation based on ultrahigh-resolution UAV video and deep neural network

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    This paper presents an advanced urban traffic density estimation solution using the latest deep learning techniques to intelligently process ultrahigh-resolution traffic videos taken from an unmanned aerial vehicle (UAV). We first capture nearly an hour-long ultrahigh-resolution traffic video at five busy road intersections of a modern megacity by flying a UAV during the rush hours. We then randomly sampled over 17 K 512×512 pixel image patches from the video frames and manually annotated over 64 K vehicles to form a dataset for this paper, which will also be made available to the research community for research purposes. Our innovative urban traffics analysis solution consists of an advanced deep neural network (DNN) based vehicle detection and localization, type (car, bus, and truck) recognition, tracking, and vehicle counting over time. We will present extensive experimental results to demonstrate the effectiveness of our solution. We will show that our enhanced single shot multibox detector (Enhanced-SSD) outperforms other DNN-based techniques and that deep learning techniques are more effective than traditional computer vision techniques in traffic video analysis. We will also show that ultrahigh-resolution video provides more information that enables more accurate vehicle detection and recognition than lower resolution contents. This paper not only demonstrates the advantages of using the latest technological advancements (ultrahigh-resolution video and UAV), but also provides an advanced DNN-based solution for exploiting these technological advancements for urban traffic density estimation

    Treatment of hepatic venous system hemorrhage and carbon dioxide gas embolization during laparoscopic hepatectomy via hepatic vein approach

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    With the improvement of laparoscopic surgery, the feasibility and safety of laparoscopic hepatectomy have been affirmed, but intraoperative hepatic venous system hemorrhage and carbon dioxide gas embolism are the difficulties in laparoscopic hepatectomy. The incidence of preoperative hemorrhage and carbon dioxide gas embolism could be reduced through preoperative imaging evaluation, reasonable liver blood flow blocking method, appropriate liver-breaking device, controlled low-center venous pressure technology, and fine-precision precision operation. In the case of blood vessel rupture bleeding in the liver vein system, after controlling and reducing bleeding, confirm the type and severity of vascular damage in the liver and venous system, take appropriate measures to stop the bleeding quickly and effectively, and, if necessary, transfer the abdominal treatment in time. In addition, to strengthen the understanding, prevention and emergency treatment of severe CO2 gas embolism in laparoscopic hepatectomy is also the key to the success of surgery. This study aims to investigate the methods to deal with hepatic venous system hemorrhage and carbon dioxide gas embolization based on author’s institutional experience and relevant literature. We retrospectively analyzed the data of 60 patients who received laparoscopic anatomical hepatectomy of hepatic vein approach for HCC. For patients with intraoperative complications, corresponding treatments were given to cope with different complications. After the operation, combined with clinical experience and literature, we summarized and discussed the good treatment methods in the face of such situations so that minimize the harm to patients as much as possible

    The RN/CFT Correspondence Revisited

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    We reconsidered the quantum gravity description of the near horizon extremal Reissner-Nordstr{\o}m black hole in the viewpoint of the AdS2_2/CFT1_1 correspondence. We found that, for pure electric case, the right moving central charge of dual 1D CFT is 6Q26 Q^2 which is different from the previous result 6Q36 Q^3 of left moving sector obtained by warped AdS3_3/CFT2_2 description. We discussed the discrepancy in these two approaches and examined novel properties of our result.Comment: revtex4, 16 pages, sign mistakes corrected, references include

    ZIF-8-Based Quasi-Solid-State Electrolyte for Lithium Batteries.

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    The quasi-solid-state electrolytes (QSSEs) with an inorganic skeleton, a solid-liquid composite material combining their respective merits, exhibit high ionic conductivity and mechanical strength. However, most quasi-solid electrolytes prepared by immobilizing ionic liquid (IL) or organic liquid electrolyte in inorganic scaffold generally have poor interface compatibility and low lithium ion migration number, which limits its application. Herein, we design and prepare a ZIF-8-based QSSE (ZIF-8 QSSE) in which the ZIF-8 has a special cage structure and interaction with the guest electrolyte to form a composite electrolyte with good ionic conductivity about 1.05 × 10-4 S cm-1 and a higher lithium-ion transference number of about 0.52. With the ZIF-8 QSSE, a protype lithium battery coupled with LiCoO2 cathode shows good electrochemical performances with an initial discharge capacity of 135 mAh g-1 at 50 mA g-1 and a remaining capacity of 119 mAh g-1 after 100 cycles, only 0.119% capacity degradation per cycle. It is worth noting that the ZIF-8-based QSSEs have good thermal stability up to 350 °C that does not show thermal runaway, which is significantly higher than that of a conventional organic liquid battery system
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