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Online since: July 2012
Authors: Tai Xuan Jia, Su Ling Gao, Chuang Lu
When it arrives the maximum power point or so, the least square method is evaluated basing on the experimental data, then calculated the point.
Finally the maximum relative error is given between the evaluatal value and experimental data.
Although the size of the generator has been reduced, the speed increasing boxes the loss, weight, noise and require regular maintenance which leads to the increase of operating costs and reduction of reliability [4].
The establishment of Grey GM (1,1) model and curve fitting of least squares GM (1, 1) model is the basic model of gray system theory. it is done through the accumulation of raw sequence, to get the new more regular sequence, and then using the differential curve fitting to accurately approach the development trend of the data sequence.
Table 1 The predictive and actual values of GM(1,1) at 8 m/s wind speed one-step predictive two-step predictive three-step predictive four-step predictive five-step predictive GM(1,1) predictive power /W 931 1084 1255 1409 1572 Actual power /W 855 1029 1186 1355 1504 The relative error /(%) 8.89 5.34 5.82 3.99 4.52 Conclusions This paper analyzes the characteristic of ,maximum power curve of wind driven generator .Through gray predictive model with the features of less needed data , high predictive precision and without priori information, this paper puts forward a new method to track maximum power point in direct-drive wind power generation system.
Online since: April 2012
Authors: Hui Chang, Hong Chao Kou, Jin Shan Li, Bin Tang, Liang Cheng
The comparison result suggests a very good correlation between experimental and predicted data.
It can learn the variety between the input and output viable, and then get the target data by memorization, association and extrapolation for its good nonlinear mapping ability.
ANN requires that the range of both input data and output data should be 0-1.
The method used in this study is: (5) where X is the original data, Xmin and Xmax is the minimum and maximum value of X, Xi is the normalized data.
Fig. 5 gives the comparison between predicted curves (include the data for training) and measured curves.
Online since: June 2021
Authors: Jia Yu Wang, Tao Zhang, Ke Meng, Ruo Xiu Xiao, Li Qun Cao, He Ren
Experiments and Discussion We selected a set of cardiac CT data from the clinical data of the Chinese PLA General Hospital to verify the interactive system of the proposed medical 3D model.
First, we used VTK to perform pseudo-color processing on cardiac data.
Leap Motion could provide considerable data of fingers, palms, wrists, and elbows.
Data sampling was performed in a circle of 1s by analyzing the results.
Rotation The judgment criteria of rotation were the absolute difference between two adjacent roll data.
Online since: June 2013
Authors: Ge Zhu, Yong Zheng, Yan Chen
The two digital signals can be processed by data sampling module of FPGA to obtain the necessary data, then the data is sent into Nios II CPU.
The Nios II CPU receives the instructions of the computer by USB data transmission module, then according to the instructions to control the data sampling module and send the data to computer by USB.
Data Acquisition Circuit design of Detection System The main hardware circuit of system is FPGA embedded data acquisition module and Nios II CPU, which are used for data collection, read and transmission.
In order to improve the efficiency of data transmission, the data transmission line and control line is separately designed, the USB data transmission module control the CPU module of NIOS II by serial port.
When the data on the USB bus deformed, the USB agreement can check the data transmission error and automatically require retransmission, therefore, the data accuracy in transmission process can be guaranteed.
Online since: September 2013
Authors: Man Yin Hu, Rui Ming Tong, Meng Jie Shi, Kun Shi, Gao Jie Xu
Thus, energy conservation and emission reduction has been promoted to a major strategic task of economic and social development in China.
Derivation of Comprehensive Evaluation Results Correlation coefficient only indicates the degree of correlation between data at one moment.
Contrastive analysis was carried out on daily operating data.
Daily Running Data of a Pumping Station and Its Analysis In this paper, daily running data of a pump station was processed.
In accordance with the calculation steps of energy consumption, the preliminary analysis was conducted on the energy consumption of the raw data.
Online since: October 2014
Authors: Wei Lai, Qi Wang
Through webpage data analysis we obtain the economic benefits detection data.
Fig. 5 HTML Webpage link operation In order to realize the continuous and real-time of economic detection data, we need to establsih connection between new projects and internet HTML data [9, 10].
Through the data interface it can realize data obtaining automatically and do economical detection.
We use J2EE detection system to detect total economic trade in one region, and obtain the total trade demand and exports under new protectionism, which provide reference data for the study of national foreign trade.
Computable general equilibrium analysis of import tariff reduction from ASEAN agricultural products on China macroeconomic and industry [J].
Online since: October 2014
Authors: Yu Ze Zhang, Wen Ying Liu, Wei Zhou Wang, Jing Jing Zheng
This text figured out the major factors influencing the fluctuation of the line loss rate, quantitatively analyzing three factors’ effects on line loss rate, which respectively are non-correspondence electric quantity for supplying and selling, the dedicated line which large consumer load transfers and the change of electric quantity which is nondestructive for sale, thus facilitating the grid enterprises dynamically analyzing the line loss in time, providing authentic line loss data for electric power departments at all levels, electricity board, power supply station, improving the accuracy of line loss analysis, dismissing the human factors during the fluctuation of line loss.
Fig.1 Monthly statistical value of comprehensive line loss rate The data in Fig.1 indicates that, monthly statistical value of the electric power company’s comprehensive line loss rate shows up apparent fluctuation.
The statistics of power sale quantity is relatively disperse, and because the number of the gauge tables is big(reach up to thousands or tens of thousands of meters), meter reading is impossible to be finished on the last day of every month, and meanwhile, we need to calculate and charge the data collected from meter reading, thus determining that power sale quantity scale meter and power supply quantity scale meter must be reading separated by turns, therefore, there exists a non-corresponding in time between the power sale quantity scale meter reading and the power supply quantity scale meter reading, causing a situation in which non-corresponding electric power quantity occurs[9].
In order to make grid’s statistics of line loss approach real line loss as possible, manipulative factor, that is power quantity of sale and supply, must be eliminated, only by enacting relative control measures, reducing line loss rate fluctuation component caused by subject factors can improve the accuracy of analysis about line loss and provide object basis for loss reduction.
[5] Zhang Lisheng, “The Technology of Management and Reduction Loss in Electric Power Energy”, China Electric Power Press, 2005 (in Chinese)
Online since: September 2024
Authors: Saloua El Euch Khay, Jamel Neji, Ines Boussetta
The reduction amounted to approximately 60% in compressive strength and 50% in flexural strength.
However, data on this property for RCC incorporating RAP remains scarce.
The extent of strength reduction depends on the replacement levels and the type of RAP utilized.
Additionally, a 100% RAP mixture was included to provide more data for developing later empirical relationships linking RCC characteristics and RAP percentage and to facilitate SEM observations of the interfacial transition zone (ITZ) between RAP particles and the cement paste.
In summary, this study offers engineers valuable experimental data for the practical application of RCC containing RAP in road construction.
Online since: March 2017
Authors: Virgil Gabriel Teodor, Nicuşor Baroiu, Florin Iftode
The paper describes the method that can be used to monitoring of a water feeding system of a civil building and its subsystems, using a graphic interface of a soft-ware pack – SCADA (Supervisory Control and data Acquisition), WinCC Flexible.
In the paper, also is analysed the situation in which three centrifugal pumps are utilized as execution elements, a pressure sensor – to measure the pressure of the water feeding system of the consumer, three sensors that detect the presence of water in each well and a Siemens programmable automaton, from the SIMATIC S7-300 series, which controls the process and a PC for the acquisition of data and for monitoring.
It has been used a pressure sensor for pressure measurement to consumer, 3 water sensors presence in each well, three centrifugal pumps as actuators, PLC Siemens S7-300 series for process management and a PC for data acquisition and monitoring.
The value 2 bars controls the reduction of the rotational speed of pump 3 from 652,44 rpm, to 326,37 rpm representing 33% of the capacity and the rest of the pumps work at 100 % of their capacity.
Pump 3 - shut down Conclusions By automating and monitoring such a pumping system, substantial reductions of costs can be obtained for the following: spare parts – reduced wear – the working tension does not run unless it is necessary; electric power – depending on the water consumption, one, two or all three pumps work; the consumption of water is rationalized; the work conditions of the staff that operates the pumps are improved.
Online since: July 2008
Authors: Giangiacomo Minak, Piero Morelli
Statistical data analysis.
(3) The values of the parameters β, γ1 and γ2 can be determined by a MLE performed on the experimental data.
For each data set, black filled markers have been used for the case of failed specimens, while empty markers have been employed for run out specimens.
Compressive loads lead to a considerably reduction on fatigue life.
Rossetto: Comparison of fatigue data using the maximum likelihood method.
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