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Online since: March 2013
Authors: Bogdan Sapiński, Maciej Rosół, Mateusz Knapik
The performance of the system was verified through experiments where it acted as a component of a vibration reduction system.
The damper and the generator are the key components of a developed vibration reduction system with energy harvesting.
Description of the system Underlying the prototype of the conditioning system are the research data summarised in [1].
The microcontroller block, incorporating a PIC16LF1827 chip, generates steering signals to analogue relays: q (AS_C), qGB (AS_GB) and qBC (AS_BC) and transmits the measurement data to the computer via a RS232 interface.
Summary The paper briefly outlines the operating principles of the system for conditioning signals from an electromagnetic generator that are used to power supply an MR damper and summarises the laboratory test data.
The damper and the generator are the key components of a developed vibration reduction system with energy harvesting.
Description of the system Underlying the prototype of the conditioning system are the research data summarised in [1].
The microcontroller block, incorporating a PIC16LF1827 chip, generates steering signals to analogue relays: q (AS_C), qGB (AS_GB) and qBC (AS_BC) and transmits the measurement data to the computer via a RS232 interface.
Summary The paper briefly outlines the operating principles of the system for conditioning signals from an electromagnetic generator that are used to power supply an MR damper and summarises the laboratory test data.
Online since: December 2014
Authors: Ming Xiao, Hui Bo Liu, Zhi Guo Zhang, Chan Ge Liu
Saiang’s group has gotten valuable monitoring data by microseimic tests and conducted study on mechanical response of EDZ around shallow tunnel in brittle rock by assuming deformation modulus distributes linearly along radius from excavation surface, as shown in Fig.3.
Fig. 1 Regular partition and uniform reduction method Fig. 2 Regular partition and linear reduction method Irregular partition and uniform reduction method.
Irregular partition and uniform reduction method is to determine EDZ’s zones by numerical calculation or curve-fitting based on field tests data, such as deformation, acoustic velocity, and then, in every zone the parameters are uniformly reduced, as shown in Fig.4.
Whatever regular or irregular partition, mechanical parameter reduction is determined according to engineering analogy or limited local monitoring data, which is experience dependent and of uncertainty due to researcher’s engineering experience and knowledge.
Thus, monitoring data needs to be effectively and generally used and analyzed to find certain macro relationship between outer characteristics and inner mechanism of excavation response, and then establish a model to connect determinations of scope and parameter reduction of EDZ.
Fig. 1 Regular partition and uniform reduction method Fig. 2 Regular partition and linear reduction method Irregular partition and uniform reduction method.
Irregular partition and uniform reduction method is to determine EDZ’s zones by numerical calculation or curve-fitting based on field tests data, such as deformation, acoustic velocity, and then, in every zone the parameters are uniformly reduced, as shown in Fig.4.
Whatever regular or irregular partition, mechanical parameter reduction is determined according to engineering analogy or limited local monitoring data, which is experience dependent and of uncertainty due to researcher’s engineering experience and knowledge.
Thus, monitoring data needs to be effectively and generally used and analyzed to find certain macro relationship between outer characteristics and inner mechanism of excavation response, and then establish a model to connect determinations of scope and parameter reduction of EDZ.
The Application of Improved Fuzzy Analytic Hierarchy Process (FAHP) in the Condenser Fault Diagnosis
Online since: November 2013
Authors: Jian Meng Yang, Ya Qing Jia, Feng Ying Liang
Since the influential factors of vacuum reduction of condenser are fuzzy and uncertain, the improved FAHP is used.
We can build a condenser vacuum reduction factors set and fault symptoms set [4].
So can establish a condenser vacuum reduction factors hierarchical analysis system.
The following is the test data: unit loads 600 MW, the exhaust steam temperature of low back pressure condenser dropping from 44℃ to 37℃, the vacuum degree rising from 93kPa to 95.6kPa, the coal consumption dropping from 240 t/h to 231 t/h.
For the failure instance in paper, the final result is "the reduction or interruption of the water pump seal water".
We can build a condenser vacuum reduction factors set and fault symptoms set [4].
So can establish a condenser vacuum reduction factors hierarchical analysis system.
The following is the test data: unit loads 600 MW, the exhaust steam temperature of low back pressure condenser dropping from 44℃ to 37℃, the vacuum degree rising from 93kPa to 95.6kPa, the coal consumption dropping from 240 t/h to 231 t/h.
For the failure instance in paper, the final result is "the reduction or interruption of the water pump seal water".
Online since: May 2011
Authors: Yan Su, Yue Ting Du, Jia Zhong Wu
Sand levee stability is influenced by the strength reduction degree of liquefaction soil layer, so this paper makes a further analysis and calculation about slide safety factor and risk probability under different reduction factors, as shown in fig3~ fig 4.
From the figure 3, we can find that safety factor reduced with decrease of soil strength reduction factor.
It is more sensitive when reduction factor is less than 0.6.
The probability of landslide changes with liquefaction soil strength reduction factor in Figure 4 demonstrates that when reduction factor decreases in range 1~5, landslide probability will have a large rangeability; When strength reduction factor is less than 0.5, failure probability almost tend to 100%.
Taking a segment levee of Minjiang (Fuzhou) downstream for a case study, the analysis data indicate the earthquake landslide risk of which is below 7 degrees.
From the figure 3, we can find that safety factor reduced with decrease of soil strength reduction factor.
It is more sensitive when reduction factor is less than 0.6.
The probability of landslide changes with liquefaction soil strength reduction factor in Figure 4 demonstrates that when reduction factor decreases in range 1~5, landslide probability will have a large rangeability; When strength reduction factor is less than 0.5, failure probability almost tend to 100%.
Taking a segment levee of Minjiang (Fuzhou) downstream for a case study, the analysis data indicate the earthquake landslide risk of which is below 7 degrees.
Online since: June 2010
Authors: Ming Jen Tan, Jing Tao Wang, Xin Ping Zhang, Ting Hui Yang
In
each case, the specimens were compressed to half their original height and the load-displacement data was recorded.
Plates will separate along the bonding face at reduction ratios of 2%, 4%, 6%, 8% and 10%, as shown in Fig.5 b).
Though it is noted that dissimilar metals and alloys can be joined by hot rolling at a large reduction ratio, the reduction ratios in the experiments were too small to create a strong bonding between the Al alloy plate and the Mg alloy plate.
Fig. 5 Separation of laminated composites at different reduction ratio: a) 1% and b) 2%.
The maximum strain at different positions increases with the reduction ration, λ.
Plates will separate along the bonding face at reduction ratios of 2%, 4%, 6%, 8% and 10%, as shown in Fig.5 b).
Though it is noted that dissimilar metals and alloys can be joined by hot rolling at a large reduction ratio, the reduction ratios in the experiments were too small to create a strong bonding between the Al alloy plate and the Mg alloy plate.
Fig. 5 Separation of laminated composites at different reduction ratio: a) 1% and b) 2%.
The maximum strain at different positions increases with the reduction ration, λ.
Online since: October 2012
Authors: Khairiah K. Turahim, Syazwani A. Rahim, Asan G.A. Muthalif
It involves transmission of data from a transmitter to a receiver.
In order to achieve successful data transmission, a continuous alignment between the transmitter and receiver telescope is needed.
Introduction Free-space optics (FSO) communication is a technology that uses light to transmit data through free space.
For an FSO link to successfully transmit data, it requires a continuous alignment between the transmitter and receiver [1].
Then the data are passed to controller which calculates the required external forces or displacement and send signals to control the actuators.
In order to achieve successful data transmission, a continuous alignment between the transmitter and receiver telescope is needed.
Introduction Free-space optics (FSO) communication is a technology that uses light to transmit data through free space.
For an FSO link to successfully transmit data, it requires a continuous alignment between the transmitter and receiver [1].
Then the data are passed to controller which calculates the required external forces or displacement and send signals to control the actuators.
Online since: August 2013
Authors: Lei Zhong, Xin Hao, Hui Zou
From 2001 to 2010, there was no significant difference of CH4 emissions per unit area between the cities, all CH4 emissions reduction was mainly due to a reduction of rice growing area.
After searching and screening, get in line with the requirements of the research on data integration [3-11], which contained the CH4 emission data of 51, distributed in 7 test points.
Experimental treatment of CH4 emission from rice data including: water management style, applied or not applied straw, the test set of different water management measures.
In this study, the rice average CH4 emissions and per unit area of the foundation data were calculated for the study area CH4 fluxes.
In 2001-2010, there are rice planting area and area reduction ratio in south Jiangsu area ( Tab. 1 ).
After searching and screening, get in line with the requirements of the research on data integration [3-11], which contained the CH4 emission data of 51, distributed in 7 test points.
Experimental treatment of CH4 emission from rice data including: water management style, applied or not applied straw, the test set of different water management measures.
In this study, the rice average CH4 emissions and per unit area of the foundation data were calculated for the study area CH4 fluxes.
In 2001-2010, there are rice planting area and area reduction ratio in south Jiangsu area ( Tab. 1 ).
Online since: July 2011
Authors: Yang Yang
The basic idea behind this sort of approaches is to approximate the matrix derived from the noisy data, with another matrix of lower rank from which the reconstructed signal is derived.
Equation (6) can be rewritten as (7) Comparing (3) and (7) yields (8) and (9) Since the matrices and are respectively the approximation of the initial clean data matrix and the noise matrix, we can reduce the effect of additive noise from the original signal via removing or decreasing the subspace and utilizing the matrix in reconstruction of the enhanced data matrix.
In this method a polynomial is fit to a number of consecutive data points from the time-series.
They include the number of rows in the Hankel data matrix “1”, the optimum threshold point needed for space subdivision “”, the degree of polynomial , “”and the window size of the Savitzky-Golay filter “” used for filtering the singular vectors.
In the traditional SVD and GSVD approaches, the singular values of the data matrix are filtered for speech enhancement, while the singular vectors of the noisy data matrix are not enhanced.
Equation (6) can be rewritten as (7) Comparing (3) and (7) yields (8) and (9) Since the matrices and are respectively the approximation of the initial clean data matrix and the noise matrix, we can reduce the effect of additive noise from the original signal via removing or decreasing the subspace and utilizing the matrix in reconstruction of the enhanced data matrix.
In this method a polynomial is fit to a number of consecutive data points from the time-series.
They include the number of rows in the Hankel data matrix “1”, the optimum threshold point needed for space subdivision “”, the degree of polynomial , “”and the window size of the Savitzky-Golay filter “” used for filtering the singular vectors.
In the traditional SVD and GSVD approaches, the singular values of the data matrix are filtered for speech enhancement, while the singular vectors of the noisy data matrix are not enhanced.
Online since: December 2014
Authors: Wei Wei Zhu
The simplified Bishop method uses GeoSLP1 software to calculate, and the strength reduction finite element method uses ABAQUS 6.10 software to calculate.
When using strength reduction finite element method, elastic modulus of soil is valued as 200MPa, Poisson's ratio is valued as 0.3.
The calculated stability factors using formula (1), formula (2), simplified Bishop method and strength reduction finite element method were recorded as F1, F2, F3 and F4.
(2) Simplified Bishop method and strength reduction finite element method can be checked each other because stability factors obtained by the two methods.
The former is easy to grasp for the first-line technical staff as its principle is intuitively clear, the latter can obtain the potential sliding surface, the stress, strain and displacement data of slope automatically but the calculation process is complex
When using strength reduction finite element method, elastic modulus of soil is valued as 200MPa, Poisson's ratio is valued as 0.3.
The calculated stability factors using formula (1), formula (2), simplified Bishop method and strength reduction finite element method were recorded as F1, F2, F3 and F4.
(2) Simplified Bishop method and strength reduction finite element method can be checked each other because stability factors obtained by the two methods.
The former is easy to grasp for the first-line technical staff as its principle is intuitively clear, the latter can obtain the potential sliding surface, the stress, strain and displacement data of slope automatically but the calculation process is complex
Online since: February 2016
Authors: Martin Doškář, Jan Stránský
We
demonstrate significant reduction in periodicity achieved with Wang tiling (compared to the periodic
synthesis) in both the microstructures and results of numerical simulations.
As a results, a significant reduction in spurious periodic artefacts in reconstructed microstructure realizations is achieved, compared to the PUC based reconstruction [1, 2].
Spatial statistics In order to validate the hypothesis of reduction of periodicity in the system and the related DEM calculations, we employ the following spatial descriptors chosen with emphasis on their sensitivity to intrinsic correlations.
In order to exploit FFT efficiency, the values are attributed to the nearest point in the regular grid and the convolution of data is calculated.
The only difference to S2 is that the data are not of boolean type.
As a results, a significant reduction in spurious periodic artefacts in reconstructed microstructure realizations is achieved, compared to the PUC based reconstruction [1, 2].
Spatial statistics In order to validate the hypothesis of reduction of periodicity in the system and the related DEM calculations, we employ the following spatial descriptors chosen with emphasis on their sensitivity to intrinsic correlations.
In order to exploit FFT efficiency, the values are attributed to the nearest point in the regular grid and the convolution of data is calculated.
The only difference to S2 is that the data are not of boolean type.