A Query Optimization Technology Based on Data Partition

2014 ◽  
Vol 536-537 ◽  
pp. 512-515
Author(s):  
Jian Qiang Dai
Keyword(s):  
Mobile Phone ◽  
Query Optimization ◽  
Data Access ◽  
Data Partitioning ◽  
Data Partition ◽  
Application System ◽  
3G Networks ◽  
Access Problems ◽  
Database Size ◽  
Low Efficiency

With the promotion of 3G networks and upcoming 4G network, mobile phone users in constant rise. The volume of data they produce will soar every day. A variety of data appear results in the database have rapid increasing. Some application system in access to these heterogeneous, huge databases is bound to access difficulties, the problem of low efficiency of access. Query optimization technology is proposed in this paper, based on data partitioning, by reducing the database size to solve the problem of memory and huge amounts of data access problems. From the experiment test, the method can effectively improve the efficiency of huge amounts of data access, can get satisfactory results.

scholarly journals A Strategy of Efficient and Accurate Cardinality Estimation Based on Query Result

2018 ◽  
Vol 36 (4) ◽  
pp. 768-777
Author(s):  
Jintao Gao ◽  
Zhanhuai Li ◽  
Wenjie Liu
Keyword(s):  
Big Data ◽  
Query Optimization ◽  
Cardinality Estimation ◽  
Estimation Strategy ◽  
Query Result ◽  
Original Table ◽  
Data Statistics ◽  
Low Efficiency

Cardinality estimation is an important component of query optimization. Its accuracy and efficiency directly decide effect of query optimization. Traditional cardinality estimation strategy is based on original table or sample to collect statistics, then inferring cardinality by collected statistics. It will be low-efficiency when handling big data; Statistics exist update latency and are gotten by inferring, which can not guarantee correctness; Some strategies can get the actual cardinality by executing some subqueries, but they do not keep the result, leading to low efficiency of fetching statistics. Against these problems, this paper proposes a novel cardinality estimation strategy, called cardinality estimation based on query result(CEQR). For keeping correctness of cardinality, CEQR directly gets statistics from query results, which is not related with data size; we build a cardinality table to store the statistics of basic tables and middle results under specific predicates. Cardinality table can provide cardinality services for subsequent queries, and we build a suit of rules to maintain cardinality table; To improve the efficiency of fetching statistics, we introduce the source aware strategy, which hashes cardinality item to appropriate cache. This paper gives the adaptability and deviation analytic of CEQR, and proves that CEQR is more efficient than traditional cardinality estimation strategy by experiments.

scholarly journals Multistage Dynamic Packet Access Mechanism of Internet of Things

2018 ◽  
Vol 2018 ◽  
pp. 1-16
Author(s):  
Yi Meng ◽  
Chen QingKui ◽  
Zhang Gang
Keyword(s):  
Internet Of Things ◽  
Resource Competition ◽  
Data Access ◽  
The Internet ◽  
Network Access ◽  
Feature Maps ◽  
Control Command ◽  
Packet Access ◽  
Low Efficiency ◽  
The Internet Of Things

In the scenario of mass control commands requesting for network access, confined by the best-effort network service mode, it is easy to bring about resource competition and thus a phenomenon of access failure on major and urgent service request at the data access center for the Internet of Things. In this event, the dynamic diversification of control command is unable to access the necessary resources on a comparatively fair basis, causing low efficiency in heterogeneous resource utilization at the access center. This paper defines the problem of group request dynamic resource allocation and further converts it into the problem of 0-1 integer and linear programming and proposes a multistage dynamic packet access strategy. This strategy works first on dynamic group division on the users’ mass control requests using the high ability of self-organizing feature maps and then searches for the optimized matching resources based on the frog-leaping algorithm which has a better capacity for global searching for the best resources. This paper analyzes the feasibility of this strategy and its astringency. The experimental results demonstrate that the strategy can effectively improve the success rate of access to the data center for the Internet of Things and reduce network blockage and response delay.

scholarly journals Coordinate Transformation between Global and Local Datums Based on Artificial Neural Network with K-Fold Cross-Validation: A Case Study, Ghana

2019 ◽  
Vol 23 (1) ◽  
pp. 67-77 ◽  
Author(s):  
Yao Yevenyo Ziggah ◽  
Hu Youjian ◽  
Alfonso Rodrigo Tierra ◽  
Prosper Basommi Laari
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Coordinate Transformation ◽  
Cross Validation ◽  
Data Partitioning ◽  
Transformation Model ◽  
Data Partition ◽  
Data Set ◽  
Artificial Neural ◽  
Fold Cross Validation

The popularity of Artificial Neural Network (ANN) methodology has been growing in a wide variety of areas in geodesy and geospatial sciences. Its ability to perform coordinate transformation between different datums has been well documented in literature. In the application of the ANN methods for the coordinate transformation, only the train-test (hold-out cross-validation) approach has usually been used to evaluate their performance. Here, the data set is divided into two disjoint subsets thus, training (model building) and testing (model validation) respectively. However, one major drawback in the hold-out cross-validation procedure is inappropriate data partitioning. Improper split of the data could lead to a high variance and bias in the results generated. Besides, in a sparse dataset situation, the hold-out cross-validation is not suitable. For these reasons, the K-fold cross-validation approach has been recommended. Consequently, this study, for the first time, explored the potential of using K-fold cross-validation method in the performance assessment of radial basis function neural network and Bursa-Wolf model under data-insufficient situation in Ghana geodetic reference network. The statistical analysis of the results revealed that incorrect data partition could lead to a false reportage on the predictive performance of the transformation model. The findings revealed that the RBFNN and Bursa-Wolf model produced a transformation accuracy of 0.229 m and 0.469 m, respectively. It was also realised that a maximum horizontal error of 0.881 m and 2.131 m was given by the RBFNN and Bursa-Wolf. The obtained results per the cadastral surveying and plan production requirement set by the Ghana Survey and Mapping Division are applicable. This study will contribute to the usage of K-fold cross-validation approach in developing countries having the same sparse dataset situation like Ghana as well as in the geodetic sciences where ANN users seldom apply the statistical resampling technique.

scholarly journals PERANCANGAN DAN IMPLEMENTASI SISTEM INFORMASI PENCARIAN ALAMAT PENTING DI KOTA PADANG MENGGUNAKAN APLIKASI MOBILE

2018 ◽  
Vol 2 (2) ◽  
Author(s):  
Ayu Fatimah ◽  
Titi Sriwahyuni ◽  
Nurindah Dwiyani
Keyword(s):  
Information System ◽  
Mobile Phone ◽  
Public Transport ◽  
Mobile Application ◽  
The Internet ◽  
Application System ◽  
Internet Service ◽  
Phone Book ◽  
Java Language ◽  
Text Display

This projects aims to provide an information system to search for the important address in Padang. The important address in Padang still use the phone book (yellow  pages),  but  not  everyone can  use and  have it.  In  the  search  for  the important address in Padang, not everyone has a mobile phone that can access the internet and if using a mobile phone, it will need the charge. As well as in the search for important addresses in Padang, not everyone can call the operator, and call the operator also takes the charge. Because of that problem, this application created with no internet service, so it does not cost money. This mobile application system can provide information such as text display with detailed  address  and  phone  numbers  and  addresses  an  important  route  in Padang. The starting address point is from Padang’s Market because a lot of public transport with the important addresses major roads in Padang is passing along this way. The mobile application comes with a list of important address like Mosques, Hospitals, Hotels, Universities and Government Offices which contain such as info address, phone number and the address route to search the important address for the application’s user. This is an implementation on mobile phone based on java language programming with jar extension file.   Keywords : Information Systems, Mobile Application, Addresses, Java .

Towards High Maturity in SaaS Applications Based on Virtualization

2013 ◽  
pp. 223-236
Author(s):  
Shijun Liu ◽  
Yong Zhang ◽  
Xiangxu Meng
Keyword(s):  
Automobile Industry ◽  
Data Access ◽  
Maturity Model ◽  
Hardware Virtualization ◽  
On Demand ◽  
Access Problems ◽  
High Maturity ◽  
Application Deployment ◽  
High Level

This paper proposes a high level maturity in SaaS applications based on virtualization technologies, in which the hardware virtualization focuses on providing the flexible on-demand hosting environment, the application virtualization used to meet the scalable application deployment requirements and data virtualization solves data integration and unified data access problems to ensure multi-tenant efficiency. In order to realize the configurability, a method based on metadata and JMX is used to manage the metadata so that changed metadata can be hot deployed immediately during runtime. A case study of a SaaS application for supply business in automobile industry is introduced with the discussion of approaches to higher level maturity model.

Technology of Mobile Phone 3D Model Reconstruction Based on the Geomagic Studio

2014 ◽  
Vol 971-973 ◽  
pp. 1357-1360
Author(s):  
Hong Mei Yu ◽  
Zi Qi Wang
Keyword(s):  
Mobile Phone ◽  
Point Cloud ◽  
3D Model ◽  
Data Access ◽  
Cad Model ◽  
Point Cloud Data ◽  
Model Reconstruction ◽  
Cloud Data ◽  
3D Model Reconstruction ◽  
Modeling Strategy

Studied the modeling strategy and application features of rapid surfacing reconstruction system. The 3D digital model reconstruction of real mobile phone as an example, using non-contact optical 3D scanning point cloud data access to mobile phone, get the mobile phone CAD model through data processing by point stage, polygon stage and shape stage, and the various stages of the process and the target are discussed in this paper.

Fuzzy rules based efficient event-driven simulation of blockchain-based applications

2021 ◽  
pp. 1-7
Author(s):  
Wei Zhou
Keyword(s):  
High Performance ◽  
Large Scale ◽  
Fuzzy Rule ◽  
Data Access ◽  
Simulation Method ◽  
Actual System ◽  
Internet Service ◽  
Event Driven ◽  
Block Chain ◽  
Low Efficiency

Decentralized application (DAPP), replacing traditional business logic and data access layer with block chain, is a new form of Internet service. Testing DAPP requires large-scale distributed systems. Performing experiments in a real system is costly and difficult. This article carefully analyses the process of block generation and synchronization and explains the reasons for the low efficiency of block chain system simulation. We incorporate fuzzy rule based model for enhancing the logging system in blockchain. Rules based on fuzzy are utilized inside system of fuzzy logic to obtain outcome on basis of input variables. The data of Ethereum and Bitcoin proves that the block generation interval conforms to the exponential distribution, and the real PoW calculation can be replaced with random numbers. Both block verification and network propagation processes have latency, which can be simulated with asynchronous messaging. Based on the above analysis, this article proposes a high-performance simulation method based on event-driven model, which is suitable for describing the communication and synchronization behave our of block chain networks. The method can effectively describe the block generation, the synchronization process between nodes, and supports different equity proof forms. Using this method, the performance of the PoW systemis tested. Under the ecs.c6.xlargeinstance,the simulation running speed reaches 782 times of actual system. Further experiments show that this method can be efficiently used in larger-scale networks and is an effective tool for DAPP developing and testing.

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