684 research outputs found

    Cache-based Query Processing for the Boolean Retrieval Model

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    We propose a new method of processing general Boolean queries utilizing previous query results stored in a result cache in a mediator architecture. A simple but noble normalization form is developed to describe keyword-based Boolean queries and the content of the result cache. We propose Boolean query processing algorithms based on this form of presentation that utilizes the result cache. We show that the proposed method theoretically guarantees improved performance over the conventional query processing method without using a cache

    One-step fabrication of surface-decorated inorganic nanowires via single-nozzle electrospinning

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    This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2017R1A6A3A03004416) and (NRF-2015M1A2A2056833).One-dimensional heterostructured nanomaterials represent key building blocks for nanotechnologies due to a large number of applications such as electronics, catalysis, drug delivery, and energy storage and conversion devices. Electrospinning has been considered a straightforward and versatile method to prepare inorganic nanowires, but the heterostructured nanowires have been only fabricated by using dual-nozzle or by introducing additional encapsulating step. Here we report one-step fabrication of surface-decorated inorganic nanowires via single-nozzle electrospinning. Although the electrospinning precursor uses one mixed solution containing nickel salt, ceria nanoparticles, and polyvinylpyrrolidine (PVP), the nanowires show a core/shell-like shape. The surface-decorated nanowires consist of nickel shell and ceria core, which exhibits 95.52% of methane conversion at 600 °C whereas conventional particle-type catalysts have only 60% at the same temperature in steam reforming.PostprintPeer reviewe

    Effects of Thermal and Humidity Aging on the Interfacial Adhesion of Polyketone Fiber Reinforced Natural Rubber Composites

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    Polyketone fiber is considered as a reinforcement of the mechanical rubber goods (MRG) such as tires, automobile hoses, and belts because of its high strength and modulus. In order to apply it to those purposes, the high adhesion of fiber/rubber interface and good sustainability to aging conditions are very important. In this study, polyketone fiber reinforced natural rubber composites were prepared and they were subjected to thermal and humidity aging, to assess the changes of the interfacial adhesion and material properties. Also, the effect of adhesive primer treatment, based on the resorcinol formaldehyde resin and latex (RFL), of polyketone fiber for high interfacial adhesion was evaluated. Morphological and property changes of the rubber composites were analyzed by using various instrumental analyses. As a result, the rubber composite was aged largely by thermal aging at high temperature rather than humidity aging condition. Interfacial adhesion of the polyketone/NR composites was improved by the primer treatment and its effect was maintained in aging conditions

    Pulmonary subsolid nodules: what radiologists need to know about the imaging features and management strategy

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    Pulmonary subsolid nodules (SSNs) refer to pulmonary nodules with pure ground-glass nodules and part-solid ground-glass nodules. SSNs are frequently encountered in the clinical setting, such as screening chest computed tomography (CT). The main concern regarding pulmonary SSNs, particularly when they are persistent, has been lung adenocarcinoma and its precursors. The CT manifestations of SSNs help radiologists and clinicians manage these lesions. However, the management plan for SSNs has not previously been standardized. Recently, the Fleischner Society published recommendations for the management of incidentally detected SSNs. The guidelines reflect the new lung adenocarcinoma classification system proposed by the International Association for the Study of Lung Cancer, American Thoracic Society, and European Respiratory Society (IASLC/ATS/ERS) and include six specific recommendations according to the nodule size, solid portion and multiplicity. This review aims to increase the understanding of SSNs and the imaging features of SSNs according to their histology, natural course, possible radiologic interventions, such as biopsy, localization prior to surgery, and current management
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