A New Quadtree-Based Skyline Query Algorithm

2014 ◽  
Vol 981 ◽  
pp. 175-178
Author(s):  
Run Tao Liu ◽  
Yuan Jing Chen ◽  
Da Yong Cao ◽  
De Yu Liu
Keyword(s):  
Detailed Analysis ◽  
Spatial Data ◽  
Index Structure ◽  
Skyline Query ◽  
Set Up ◽  
Query Algorithm

In this paper, the index structure, PR-quadtree for spatial data, is used to store data for a database. The properties of the quadtree are studied. With the properties prunning rules are set up for searching the Skyline set of the data stored in the quadtree. Through detailed analysis for the tree the method of finding some approximate skyline points is designed, by which a new skyline searching algorithm is given. The new algorithm is more effective.

User Preference Based Spatial Skyline Query Method

2014 ◽  
Vol 530-531 ◽  
pp. 832-838
Author(s):  
Yong Gui Zou ◽  
Zhi Wang
Keyword(s):  
Spatial Data ◽  
Road Network ◽  
User Preference ◽  
Skyline Query ◽  
Data Set ◽  
Second Stage ◽  
Processing Data ◽  
Data Volume ◽  
Definition Of ◽  
Query Algorithm

With the increasing of data volume and data dimensions in road network query, the response gets slow in searching services, which cannot satisfy users demand for preference-based searching. This paper proposes a user preference-based Skyline query algorithm. At the first stage, this method is based on the fact that the static property of data does not change during the query processes. Therefore, Skyline starts its calculation in the non-spatial data set to have the candidate results and dominance relation. Then it calculates the total costs of routine by defining user preference function. At the second stage, compare the data connections with the total costs of preference to minimize time for processing data and searching. The experiment result shows that the definition of user preference meets the users demand, and Skyline query algorithm benefits to have quick response.

Accuracy assessment of a mobile terrestrial laser scanner for tree crops

2017 ◽  
Vol 8 (2) ◽  
pp. 178-182 ◽  
Author(s):  
F. H. S. Karp ◽  
A. F. Colaço ◽  
R. G. Trevisan ◽  
J. P. Molin
Keyword(s):  
Data Acquisition ◽  
Spatial Data ◽  
Accuracy Assessment ◽  
Laser Scanner ◽  
Terrestrial Laser Scanner ◽  
Tree Crops ◽  
Area Estimation ◽  
Gnss Receiver ◽  
Truncated Cone ◽  
Set Up

LiDAR technology is one option to collect spatial data about canopy geometry in many crops. However, the method of data acquisition includes many errors related to the LiDAR sensor, the GNSS receiver and the data acquisition set up. Therefore, the objective of this study was to evaluate the errors involved in the data acquisition from a mobile terrestrial laser scanner (MTLS). Regular shaped objects were scanned with a developed MTLS in two different tests: i) with the system mounted on a vehicle and ii) with the system mounted on a platform running over a rail. The errors of area estimation varied between 0.001 and 0.071 m2 for the circle, square and triangle objects. The errors on volume estimations were between 0.0003 and 0.0017 m3, for cylinders and truncated cone.

scholarly journals Precision geoinformatical system of the pear gene-collection orchard

2012 ◽  
Vol 18 (1) ◽  
Author(s):  
J. Tamás ◽  
A. Nagy ◽  
T. Fórián ◽  
J. Nyéki ◽  
T. Szabó ◽  
...  
Keyword(s):  
Data Base ◽  
Spatial Data ◽  
Single Species ◽  
Field Work ◽  
Stress Sensitivity ◽  
Hyperspectral Data ◽  
Data Cube ◽  
The Sustainable Development ◽  
Fruit Species ◽  
Set Up

The principle task of the sustainable development is the preservation of the genetic variety, which is similar challenge in the horticulture regarding the sublimation of fruit species. The breeders of the traditional fruit strains give stock to the sustenance diversity of the agro-environment on the species and landscape level. In 2009, hyperspectral images have been taken by AISA Dual sensors from the pear gene pool in Újfehértó, Hungary. The hyperspectral data cube (in the wavelength range of 400-2500 nm, with 1.5 m ground resolution) ensured possibility to make the spectral library of pear species. In the course of the simultaneously field work the spatial position and individual extent of all pear trees was defined to set up a detailed GIS data base. The water stress sensitivity of single species and the descriptive spectral curves were determined with common evaluation of the spectral and spatial data. Based on the unique methodology processing and the hyperspectral data base suitable strains can be chosen for agro-environment and let take adaptive stocks regarding climate change into the genetic grafting work. Furthermore we could determine and map the sparsely species in the region with the help of the hyperspectral data.

Efficient Indexing RDF Query Algorithm for Big Data

2013 ◽  
Vol 441 ◽  
pp. 691-694
Author(s):  
Yi Qun Zeng ◽  
Jing Bin Wang
Keyword(s):  
Large Scale ◽  
Rapid Development ◽  
Large Data ◽  
Index Structure ◽  
Data Query ◽  
Large Scale Data ◽  
Tree Index ◽  
Rdf Data ◽  
Query Algorithm ◽  
Scale Data

With the rapid development of information technology, data grows explosionly, how to deal with the large scale data become more and more important. Based on the characteristics of RDF data, we propose to compress RDF data. We construct an index structure called PAR-Tree Index, then base on the MapReduce parallel computing framework and the PAR-Tree Index to execute the query. Experimental results show that the algorithm can improve the efficiency of large data query.

k-dominant Skyline query algorithm for dynamic datasets

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Zhiyun Zheng ◽  
Ke Ruan ◽  
Mengyao Yu ◽  
Xingjin Zhang ◽  
Ning Wang ◽  
...  
Keyword(s):  
Skyline Query ◽  
Query Algorithm

A Spatial Resource Top-K Query Algorithm in Cyber Physical System

2013 ◽  
Vol 774-776 ◽  
pp. 1725-1728
Author(s):  
Wu Bin Ma ◽  
Ming Xing Liu ◽  
Su Deng ◽  
Hong Bin Huang
Keyword(s):  
Physical System ◽  
Empirical Studies ◽  
Index Structure ◽  
Cyber Physical System ◽  
Resource Network ◽  
Spatial Environment ◽  
Uncertain Factor ◽  
Retrieving Algorithm ◽  
Physical Elements ◽  
Query Algorithm

Cyber physical system (CPS) mainly means that the conjoining of information and physical resources. The physical elements, which could be treated as spatial resources, need be queried through information field. The key problem is how to construct spatial resource index structure and accordingly retrieving algorithm. The spatial retrieving algorithm is widely used in the Internet and moving object. The traditional spatial resource retrieving algorithms ignore the uncertain factor of the spatial resource, which is the important feature of the military resource network. This paper use an index structure named BIR-tree, based on the belief of resource, we also propose corresponding efficient and accurate top-k retrieving algorithm. On the base of traditional IR-tree, we define the resource and regional belief aiming at special spatial environment. The results of our empirical studies with an implementation of the proposed algorithm show it is capable of excellent performance.

scholarly journals A Power Grid Fault Diagnosis Method in the Case of Alarm Information Loss Based on the Top-k Skyline Query Algorithm

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6223
Author(s):  
Lei Jin ◽  
Qing Chen ◽  
Jinjie Ji ◽  
Xiaotong Zhou
Keyword(s):  
Fault Diagnosis ◽  
Power Grid ◽  
Circuit Breaker ◽  
Information Loss ◽  
Uncertain Information ◽  
Skyline Query ◽  
Data Set ◽  
Information Set ◽  
Diagnosis Method ◽  
Query Algorithm

After the failure of the power system, a large amount of alarm information will flood into the dispatching terminal instantly. At the same time, there are inevitable problems, such as the abnormal operation of the protection and the circuit breaker, the lack of alarm information, and so on. This kind of uncertainty problem brings great trouble to the fault diagnosis algorithm. As a data processing algorithm for an uncertain information set, Top-k Skyline query algorithm can eliminate the data points that do not meet the requirements in the information set, and then output the final K results in order. Based on this background, this paper proposes a power grid fault diagnosis method based on the Top-k Skyline query algorithm considering alarm information loss. Firstly, the fault area is determined by using the information of the electrical quantity and switching value. Then, backward reasoning Petri nets are established for the nodes in the fault area to form the data set of fault hypotheses. Then, the Top-k Skyline query algorithm is used to sort the hypotheses and choose the hypothesis with higher reliability. Finally, an IEEE 39-bus system example is given to verify the reliability of the proposed method.

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