Clue-based Spatio-textual Query

Along with the proliferation of online digital map and location-based service, very large POI (point of interest) databases have been constructed where a record corresponds to a POI with information including name, category, address, geographical location and other features. A basic spatial query in POI database is POI retrieval. In many scenarios, a user cannot provide enough information to pinpoint the POI except some clue. For example, a user wants to identify a caf é in a city visited many years ago. SHe cannot remember the name and address but she still recalls that "the caf é is about 200 meters away from a restaurant; and turning left at the restaurant there is a bakery 500 meters away, etc.". Intuitively, the clue, even partial and approximate, describes the spatio-textual context around the targeted POI. Motivated by this observation, this work investigates clue-based spatio-textual query which allows user providing clue, i.e., some nearby POIs and the spatial relationships between them, in POI retrieval. The objective is to retrieve k POIs from a POI database with the highest spatio-textual context similarities against the clue. This work has deliberately designed data-quality-tolerant spatio-textual context similarity metric to cope with various data quality problems in both the clue and the POI database. Through crossing valuation, the query accuracy is further enhanced by ensemble method. Also, this work has developed an index called roll-out-star R-tree (RSR-tree) to dramatically improve the query processing efficiency. The extensive tests on data sets from the real world have verified the superiority of our methods in all aspects. </jats:p

Imaging features of neonatal systemic juvenile xanthogranuloma: A case report and review of the literature

Juvenile xanthogranuloma (JXG) is the most common non-Langerhans cell histiocytic disorder in children. This report describes the case of a 28-day-old boy that presented with multiple subcutaneous nodular lesions on the trunk and extremities, and multiple red nodular lesions on the scrotum. Magnetic resonance imaging (MRI) of the brain showed a well-demarcated extra-axial dura-based mass that appeared isointense or slightly hyperintense on T1-weighted images, hypointense on T2-weighted images and had intense enhancement on gadolinium-enhanced T1-weighted images. Computed tomography (CT) or MRI scans of the chest and abdomen revealed multiple scattered nodular or patchy lesions of varying sizes in the lungs, liver and left kidney. Histological analysis of a subcutaneous mass suggested JXG. The patient was diagnosed with neonatal systemic JXG with involvement of the central nervous system, lungs, liver, kidneys, subcutaneous soft tissue and skin. CT and MRI after 3 months of treatment with methylprednisolone sodium succinate demonstrated that the lesions were obviously diminished. This report discusses the imaging findings in this current case of multi-organ JXG and reviews the imaging literature on this condition to improve awareness of the lesions in order to help radiologists establish an accurate differential diagnosis when confronted with similar cases

Experimental Progress on Layered Topological Semimetals

We review recent experimental progresses on layered topological materials, mainly focusing on transitional metal dichalcogenides with various lattice types including 1T, Td and 1T' structural phases. Their electronic quantum states are interestingly rich, and many appear to be topological nontrivial, such as Dirac/Weyl semimetallic phase in multilayers and quantum spin hall insulator phase in monolayers. The content covers recent major advances from material synthesis, basic characterizations, angle-resolved photoemission spectroscopy measurements, transport and optical responses. Following those, we outlook the exciting future possibilities enabled by the marriage of topological physics and two dimensional van der Waals layered heterostructures.Comment: 2D Materials (2019

Evidence for quasi-one-dimensional charge density wave in CuTe by angle-resolved photoemission spectroscopy

We report the electronic structure of CuTe with a high charge density wave (CDW) transition temperature Tc = 335 K by angle-resolved photoemission spectroscopy (ARPES). An anisotropic charge density wave gap with a maximum value of 190 meV is observed in the quasi-one-dimensional band formed by Te px orbitals. The CDW gap can be filled by increasing temperature or electron doping through in situ potassium deposition. Combining the experimental results with calculated electron scattering susceptibility and phonon dispersion, we suggest that both Fermi surface nesting and electron-phonon coupling play important roles in the emergence of the CDW