scholarly journals Efficient Processing of Top-k Frequent Spatial Keyword Queries

2021 ◽  
Author(s):  
Tao Xu ◽  
Aopeng Xu ◽  
Joseph Mango ◽  
Pengfei Liu ◽  
Xiaqing Ma ◽  
...  
Keyword(s):  
High Speed ◽  
Concept Lattice ◽  
Mobile Network ◽  
Index Structure ◽  
Hybrid Index ◽  
Multiple Sources ◽  
Keyword Query ◽  
Spatial Keyword Query ◽  
Performance Results ◽  
Mobile Communication Technology

Abstract The rapid popularization of high-speed mobile communication technology and the continuous development of mobile network devices have given spatial textual big data (STBD) new dimensions due to their ability to record geographical objects from multiple sources and with complex attributes. Data mining from spatial textual datasets has become a meaningful study. As a popular topic for STBD, the top-k spatial keyword query has been developed in various forms to deal with different retrievals requirements. However, previous research focused mainly on indexing locational attributes and retrievals of few target attributes, and these correlations between large numbers of the textual attributes have not been fully studied and demonstrated. To further explore interrelated-knowledge in the textual attributes, this paper defines the top-k frequent spatial keyword query (tfSKQ) and proposes a novel hybrid index structure, named RCL-tree, based on the concept lattice theory. We also develop the tfSKQ algorithms to retrieve the most frequent and nearest spatial objects in STBD. One existing method and two baseline algorithms are implemented, and a series of experiments are carried out using real datasets to evaluate its performance. Results demonstrated the effectiveness and efficiency of the proposed RCL-tree in tfSKQ with the complex spatial multi keyword query conditions.

scholarly journals Design and Analysis of Spatial Skyline Queries Indexing

2020 ◽  
Vol 9 (4S2) ◽  
pp. 23-29
Keyword(s):  
Current Practice ◽  
Dimensional Space ◽  
Information Age ◽  
Secondary Memory ◽  
Skyline Query ◽  
Skyline Queries ◽  
Keyword Query ◽  
Spatial Keyword Query ◽  
Nearest Points ◽  
The Ideal

Dwelling in the information age permits nearly everybody needs to recover countless information and choices to gather from to fulfill their necessities. In distinctive cases, the quantity of information accessible and the speed of change may cover the ideal and required explanation. Spatial-textual queries provide the most acclaimed nearest points concerning a conveyed site and a keyword set. Current practice regularly thought on the most capable technique to expertly get the top-k resultset reestablished a spatial-scholarly query. A capable Spatial Range Skyline Query (SRSQ) algorithm is proposed which initially performsa spatial keyword query (SKQ) that relies upon an IRtree that documents the information. Skyline centers picked are not simply established on their partitions to a lot of inquiries and more subject to their significance to a social occasion of query keywords. Additionally, besides proposed range skyline (RS) methods based on R-tree multi-dimensional space including secondary- memory pruning tools for operating field skyline queries is accomplished. The advanced scheme is dynamic and I/O optimum. Ultimately, methodology presents a modern assessment that demonstrates the proficiency.

scholarly journals Study and Investigation on 5G Technology: A Systematic Review

Sensors ◽  
2021 ◽  
Vol 22 (1) ◽  
pp. 26
Author(s):  
Ramraj Dangi ◽  
Praveen Lalwani ◽  
Gaurav Choudhary ◽  
Ilsun You ◽  
Giovanni Pau
Keyword(s):  
Mobile Networks ◽  
High Speed ◽  
Future Research ◽  
Mobile System ◽  
Fifth Generation ◽  
Research Article ◽  
Next Generation Mobile Networks ◽  
Multiple Input ◽  
Multiple Challenges ◽  
Mobile Communication Technology

In wireless communication, Fifth Generation (5G) Technology is a recent generation of mobile networks. In this paper, evaluations in the field of mobile communication technology are presented. In each evolution, multiple challenges were faced that were captured with the help of next-generation mobile networks. Among all the previously existing mobile networks, 5G provides a high-speed internet facility, anytime, anywhere, for everyone. 5G is slightly different due to its novel features such as interconnecting people, controlling devices, objects, and machines. 5G mobile system will bring diverse levels of performance and capability, which will serve as new user experiences and connect new enterprises. Therefore, it is essential to know where the enterprise can utilize the benefits of 5G. In this research article, it was observed that extensive research and analysis unfolds different aspects, namely, millimeter wave (mmWave), massive multiple-input and multiple-output (Massive-MIMO), small cell, mobile edge computing (MEC), beamforming, different antenna technology, etc. This article’s main aim is to highlight some of the most recent enhancements made towards the 5G mobile system and discuss its future research objectives.

scholarly journals Efficient Geo-Textual Hybrid Indexing Techniques for Moving Objects and Queries

2020 ◽  
Vol 8 (6) ◽  
pp. 4419-4428
Keyword(s):  
Moving Objects ◽  
Traffic Monitoring ◽  
Spatial Index ◽  
Index Structure ◽  
Maintenance Cost ◽  
Hybrid Index ◽  
Indexing Techniques ◽  
Inverted List ◽  
Textual Data ◽  
Future Position

Advancements of various Geographic Information Technologies have resulted in huge growth in Geo-Textual data. Many Indexing and searching algorithms are developed to handle this Geo-Textual data which contains spatial, textual and temporal information. In past, Indexing and searching algorithms are developed for the applications in which the object trajectory or velocity vector is known in advance and hence we can predict the future position of the objects. There are real time applications like emergency management systems, traffic monitoring, where the objects movements are unpredictable and hence future position of the objects cannot be predicted. Techniques are required to answer the geo-textual kNN query where the velocity vectors or trajectories of moving and moving queries are not known. In case of moving objects, capturing current position of the object and maintaining spatial index optimally is very much essential. The hybrid indexing techniques used earlier are based on R-tree spatial index. The nodes of the R-tree index structure are split or merged to maintain the locations of continuously moving objects, increasing the maintenance cost as compared to the grid index. In this paper a solution is proposed for creating and maintaining hybrid index for moving objects and queries based on grid and inverted list hybrid indexing techniques. The method is also proposed for finding Geo-Textual nearest neighbours for static and moving queries using hybrid index and conceptual partitioning of the grid. The overall gain reported by the experimental work using hybrid index over the non- hybrid index is 30 to 40 percent depending on the grid size chosen for mapping the data space and on the parameters of queries.

IOT-5G-Exploring next-generation media consumption in the area of Journalism

2021 ◽  
Vol 9 (9) ◽  
pp. 1448-1451
Author(s):  
Sree Naga Raja Sekhar Mallela
Keyword(s):  
Internet Of Things ◽  
Mass Communication ◽  
High Speed ◽  
Data Transfer ◽  
Network Connectivity ◽  
Mobile Network ◽  
The Internet ◽  
4G Networks ◽  
Communication Devices ◽  
The Internet Of Things

Abstract: The most common buzzwords in the world is “The Internet of things” (IoT) and IOT describes the network of physical objects, so known as, "things" those are rooted with sensors in the devices, application software, technologies that is used for the resolution of connecting one end to another end and exchanging information with other devices and systems over the Internet. The IoT 5G technologies can also be used in journalism and the primary focus is to increase M2M interaction of mass communication devices. One way it is “ubiquitous computing” can occur using any device, in any location, and in any format. The Internet of Things (IoT) is all about small cost sensors grabbing data to communicate with one device to another device using cloud solutions. Coming to the 5th generation mobile network. We have already started using 4G networks and as we know that, start with 1G, 2G, 3G, and 4G networks. The 5th generation network is going to enable an upcoming new network that will associate virtually every person globally connected and everything organized including IoT devices, objects and machines. Central communication and Journalism is the activity of gathering right information, evaluating, generating, and presenting broadcast information. It is high time to start using IOT Technology using 5th generation high-speed network connectivity devices to communicate or data transfer in the area of journalism. Keywords: IOT – Internet Of Things, 5G- Fifth Generation in data network, JMC – Journalism and Mass Communications, M2M – Machine to Machine, Cloud , Artificial intelligence and Machine Learning.

Refined Performance Results on a Slowed Mach-Scaled Rotor at High Advance Ratios

2020 ◽  
Vol 65 (1) ◽  
pp. 1-13
Author(s):  
Xing Wang ◽  
Lauren Trollinger ◽  
Inderjit Chopra
Keyword(s):  
Wind Tunnel ◽  
High Speed ◽  
Reverse Flow ◽  
Flow Region ◽  
Comprehensive Analysis ◽  
Compressibility Effect ◽  
Inflow Condition ◽  
Advance Ratio ◽  
Slowed Rotor ◽  
Performance Results

Owing to its ability to alleviate the compressibility effect on the advancing side, the slowed rotor operating at high advance ratios is a key feature in high-speed compound rotorcraft. A series of wind tunnel tests were conducted in the Glenn L. Martin Wind Tunnel with a four-bladed Mach-scaled articulated rotor. The objective of the tests was to gain a basic understanding of unique features of high-advance-ratio aerodynamic phenomena, such as thrust reversal and dynamic stall in the reverse flow region. In this study, high-advance-ratio tests were carried out with highly similar, noninstrumented blades and on-hub control angle measurements, to minimize possible error due to blade structural dissimilarity and pitch angle discrepancy. The tests were conducted at 900 and 1200 RPM, advance ratios of 0.3–0.9, and a shaft tilt study was conducted at±4°. Pitch and flap motion at the blade roots, rotor performance, and vibratory hub loads were investigated during the test. The test data were then compared with those of previous tests and with predictions from comprehensive analysis. The airload results were investigated using comprehensive analysis to gain insights into the influences of advance ratio and shaft tilt angle on rotor performance and hub vibratory loads. Results indicate that the thrust benefit from backward shaft tilt is dependent on the change in the inflow condition and the induced angle of attack increment, and the reverse flow region at high advance ratios is the major contributor to changes in shaft torque and horizontal force.

Corrosion behavior of rare earth modified WC-12Co coating

2015 ◽  
Vol 29 (10n11) ◽  
pp. 1540029 ◽  
Author(s):  
Yan Liu ◽  
Hui Chen ◽  
Shengbo Ceng ◽  
Guoqing Gou ◽  
Mingjing Tu
Keyword(s):  
Corrosion Resistance ◽  
Rare Earth ◽  
High Speed ◽  
Interfacial Strength ◽  
Binder Phase ◽  
Hvof Spraying ◽  
Electrochemical Tests ◽  
Corrosion Mechanisms ◽  
Performance Results ◽  
Surface Morphologies

Rare earth has been widely used in materials manufacturing to improve hardness and toughness. In this paper, conventional, nano-modified and CeO 2 modified WC-12Co coatings are produced by using high speed oxygen flaming (HVOF) spraying technology. Long-term immersion and electrochemical tests of these coatings in 3.5 wt.% NaCl solution are conducted. The surface morphologies were observed to investigate the corrosion mechanisms. The results show CeO 2 modified WC-12Co coatings to possess the best corrosion resistance but the nano-modified WC-12Co coating has the worst performance. Results suggest that the improvement of corrosion resistance for CeO 2 modified WC-12Co coating can be attributed to the enhancement of interfacial strength between Co binder phase and WC particles.

The Design of High-Speed Synchronization Data Collection Node Machine for Multi-Chip CCD Measurement

2013 ◽  
Vol 427-429 ◽  
pp. 702-707
Author(s):  
Li Li ◽  
Guo Fu Yin
Keyword(s):  
High Speed ◽  
Image Data ◽  
Large Field ◽  
Protocol Stack ◽  
Visual Technology ◽  
Field Of Vision ◽  
Communication Module ◽  
Drive Pulse ◽  
Performance Results ◽  
Ccd Image

The high-speed synchronous node machine is developed for collecting high-precision and synchronous data from multi-chip CCD to measure the dynamic object with large field coverage by Visual technology. Node machine contains core, A/D converter module and Ethernet communication module. The FPGA of 600,000 gates which have a built-in FLASH chip is used as the core, which provides work-frequency of 10MHz and drive pulse for multi-chip CCD. A/D converter module configures the differential amplifier and builds 3-way 30MHz 16-bit A / D converter. 10/100M Ethernet protocol stack controller and RJ45 interface are internally installed in Ethernet module. This module also uses CC2430 chip to perform fast wireless synchronization control. Paper emphasizes how to implement the key technologies of multi-chip CCD for synchronous and precision measurement, and test the node machine by 5-chip CCD image data synchronous collecting with large field of vision. The node machine runs smoothly and reliably .The performance results of test show that the speed of image data collecting reaches up to 1800 frames/s, the speed of data processing reaches up to 150M Bytes/s and the transporting speed reaches up to 50M Bytes/s. The time of synchronous control is within 2 us.

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