Geo-Skip List Data Structure ? Implementation and Solving Spatial Queries

A major portion of the queries fired on the internet have spatial keywords in them, the storage and retrieval of spatial data has become an important task in today?s era. Given a geographic query that is composed of query keywords and a location, a geographic search engine retrieves documents that are the most textually and spatially relevant to the query keywords and the location, respectively, and ranks the retrieved documents according to their joint textual and spatial relevance to the query. The lack of an efficient index that can simultaneously handle both the textual and spatial aspects of the documents makes existing geographic search engines inefficient in answering geographic queries. There are data structures which facilitate storage and retrieval of geographical data like R-trees, R* trees, KD trees etc. We propose Geo-Skip list data structure which is also one such data structure which is inspired from the skip list data structure. It is simple, dynamic, partly deterministic and partly randomized data structure. This structure brings out the hierarchy of administrative divisions of a region very well. Also it shows an improvement in the search efficiency as compared with R-trees. In this paper, we propose algorithms for the implementation of basic spatial queries with the help of Geo-Skip List data structure ? namely, point query, range query, finding the nearest neighbour query and kth nearest neighbour query

On Simultaneous Information and Energy Transmission through Quantum Channels

The optimal rate at which information can be sent through a quantum channel when the transmitted signal must simultaneously carry some minimum amount of energy is characterized. To do so, we introduce the quantum-classical analogue of the capacity-power function and generalize results in classical information theory for transmitting classical information through noisy channels. We show that the capacity-power function for a quantum channel, for both unassisted and private protocol, is concave and also prove additivity for unentangled and uncorrelated ensembles of input signals. This implies we do not need regularized formulas for calculation. We numerically demonstrate these properties for some standard channel models. We obtain analytical expressions for the capacity-power function for the case of noiseless channels using properties of random quantum states and concentration phenomenon in large Hilbert spaces.Comment: 13 pages, 16 figure

Pancreatic Incidentalomas: Review and Current Management Recommendations

AbstractThere has been significant increase in the detection of incidental pancreatic lesions due to widespread use of cross-sectional imaging like computed tomography and magnetic resonance imaging supplemented with improvements in imaging resolution. Hence, accurate diagnosis (benign, borderline, or malignant lesion) and adequate follow-up is advised for these incidentally detected pancreatic lesions. In this article, we would review the various pancreatic parenchymal (cystic or solid) and ductal lesions (congenital or pathological), discuss the algorithmic approach in management of incidental pancreatic lesions, and highlight the key imaging features for accurate diagnosis.</jats:p