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Online since: December 2012
Authors: Shuang Shuang Yin, Zhong Xun Wang
The primary goal of quantization for hardware implementation is to find a fixed-point model that has all bits-widths as small as possible under the condition of an acceptable degradation of the coding performance[2].In hardware implementation, the reduction of data-path bit-widths ,control complexity and memory size lead to reduction of area and power consumption and an increase of speed.
The input data quantization as well as the inner data quantization have major influence on the control complexity and directly determine the bit-widths of data-path and memory size.
Influence of the input data quantization Fig. 6.
The optimization of memory size is focus on the storage of input data and the inner data.
We can know that the judgmental data has two kinds of sources, which are the input data and the received data sended by the check nodes(inner data can reuse the storage area).
The input data quantization as well as the inner data quantization have major influence on the control complexity and directly determine the bit-widths of data-path and memory size.
Influence of the input data quantization Fig. 6.
The optimization of memory size is focus on the storage of input data and the inner data.
We can know that the judgmental data has two kinds of sources, which are the input data and the received data sended by the check nodes(inner data can reuse the storage area).
Online since: July 2013
Authors: Jian Chun Gong, Yu Rong Zhou, Da Xing Chen, Deng Rong Zhou
The artribary waveform data can be downloaded and updated from a communication interface.
When each clock pulse fs comes, the adder adds the frequency control word k and accumulative phase data outputted by accumulator register, and the result is sent to the data input terminal in accumulator register.
It receives and stores the frequency and phase control word data sent by MCU.
The input data in register will control the frequency and phase sent by MCU when the next clock comes.
Arbitrary waveform data register RWREG receives the arbitrary waveform data sent by upper computer, and output selector MUX can realize the swift of arbitrary waveform and phase switching sine wave.
When each clock pulse fs comes, the adder adds the frequency control word k and accumulative phase data outputted by accumulator register, and the result is sent to the data input terminal in accumulator register.
It receives and stores the frequency and phase control word data sent by MCU.
The input data in register will control the frequency and phase sent by MCU when the next clock comes.
Arbitrary waveform data register RWREG receives the arbitrary waveform data sent by upper computer, and output selector MUX can realize the swift of arbitrary waveform and phase switching sine wave.
Online since: December 2014
Authors: Nikoleta Husáková
A suitable approach to eco-logistics implementation creates conditions for logistics costs reduction and also for natural resources and environment saving.
The basic measurements of eco-logistics in the sense of aforesaid knowledge are possible to categorize as follows [14]: 1. assessment of impacts on the environment; 2. integrated prevention, control of pollution; 3. controlling of raw materials, energy produced by the process of production; 4. determination of conditions for realization of activities in operational conditions; 5. realization of monitoring for all potential and existing (known) sources of emissions; 6. determination of the best available technique; 7. realization of control activities in operations, measurement of pollutants escape; 8. effective information system for collection, processing and evaluation of data; 9. effective system for waste management; 10. publicization of influences on the environment.
By comparison of principles of sustainable development and modified principles of eco-logistics it is possible to monitor reduction of some principles of sustainable development, namely Principle of intra-generation, intergeneration, global equality of rights of people on Earth, Principle of cultural and social integrity, Principle of nonviolence, Principle of emancipation and participation, Principle of solidarity.
Table 1 Basic difference between the bolier PK4 and PK4n Boiler PK4 - melting Boiler PK4n - granulating High temperature of combustion Regulated band process of combustion Decreasing of boiler effectiveness Higher boiler effectiveness Rotary air heater with difficult maintainance Use of multiple air heater with more simply maintainance High content of volatile combustible Low content of volatile combustible Continuous operation of gas rings Does not require continuous operation of gas rings Inactiveness of secondary measure to reduction of emission of NOx Use of secondary measure to reduction of emission of NOx In the next step it was defined these five criteria for more precisely comparison of variants: thermal efficiency of coal, heating capacity of coal, coal consumption, fulfilling of emission limit and emissions.
It is possible to apply band process of combustion and also a primary method of reduction of emission NOx.
The basic measurements of eco-logistics in the sense of aforesaid knowledge are possible to categorize as follows [14]: 1. assessment of impacts on the environment; 2. integrated prevention, control of pollution; 3. controlling of raw materials, energy produced by the process of production; 4. determination of conditions for realization of activities in operational conditions; 5. realization of monitoring for all potential and existing (known) sources of emissions; 6. determination of the best available technique; 7. realization of control activities in operations, measurement of pollutants escape; 8. effective information system for collection, processing and evaluation of data; 9. effective system for waste management; 10. publicization of influences on the environment.
By comparison of principles of sustainable development and modified principles of eco-logistics it is possible to monitor reduction of some principles of sustainable development, namely Principle of intra-generation, intergeneration, global equality of rights of people on Earth, Principle of cultural and social integrity, Principle of nonviolence, Principle of emancipation and participation, Principle of solidarity.
Table 1 Basic difference between the bolier PK4 and PK4n Boiler PK4 - melting Boiler PK4n - granulating High temperature of combustion Regulated band process of combustion Decreasing of boiler effectiveness Higher boiler effectiveness Rotary air heater with difficult maintainance Use of multiple air heater with more simply maintainance High content of volatile combustible Low content of volatile combustible Continuous operation of gas rings Does not require continuous operation of gas rings Inactiveness of secondary measure to reduction of emission of NOx Use of secondary measure to reduction of emission of NOx In the next step it was defined these five criteria for more precisely comparison of variants: thermal efficiency of coal, heating capacity of coal, coal consumption, fulfilling of emission limit and emissions.
It is possible to apply band process of combustion and also a primary method of reduction of emission NOx.
Online since: September 2014
Authors: Hyun Bum Park
The size and shape of damage zone greatly affects the reduction of the compressive strength.
This KC-100 aircraft adopted the whole composite structure concept for environmental friendly through low fuel consumption due to structure weight reduction as well as for a competitive aircraft market.
Fig. 2 Impact test machine and residual compression test after impact damage To obtain reliable test data, many specimens for each fabric and UD laminate are used.
Conclusions This work is to investigate impact damage behavior and the residual compressive strength after impact damage of carbon/epoxy fabric and UD laminates which will be used for certification data base for the development of KC-100 small scale aircraft.
This KC-100 aircraft adopted the whole composite structure concept for environmental friendly through low fuel consumption due to structure weight reduction as well as for a competitive aircraft market.
Fig. 2 Impact test machine and residual compression test after impact damage To obtain reliable test data, many specimens for each fabric and UD laminate are used.
Conclusions This work is to investigate impact damage behavior and the residual compressive strength after impact damage of carbon/epoxy fabric and UD laminates which will be used for certification data base for the development of KC-100 small scale aircraft.
Online since: March 2014
Authors: Bao Dong Chen, Feng Guo, Jing Wen
In order to improve the understanding deformation behaviors of thermal compressive of ZK30 magnesium alloy, carried out a series of thermal compressive tests with height reduction 60% of specimens were performed at deformation temperature range of 523-673 K, and strain rates range of 0.001-1 s−1 on Gleeble-1500 thermo-mechanical simulator.
The reduction in height is 60% at the end of the thermal compression test.
Comparing these flow curves with one another, thus it can be seen that flow stress decreases markedly with increases in deformation temperature for a particular strain rate, over 62% reduction.
Based on the experimental data, the main points resulted from the present work are presented as follows: (1) At constant strain rate, the deformation behavior of ZK30 magnesium alloy is characterized by the typical dynamic recrystallization and recovery softening mechanisms occur simultaneously.
(2) The parameters of constitutive model in the whole range of deformation conditions were determined by linear fitting test data, such as the apparent activation energy (Q) was estimated to be on average 144.072 KJmol−1, the stress exponents (n) were measured to be 5.386.
The reduction in height is 60% at the end of the thermal compression test.
Comparing these flow curves with one another, thus it can be seen that flow stress decreases markedly with increases in deformation temperature for a particular strain rate, over 62% reduction.
Based on the experimental data, the main points resulted from the present work are presented as follows: (1) At constant strain rate, the deformation behavior of ZK30 magnesium alloy is characterized by the typical dynamic recrystallization and recovery softening mechanisms occur simultaneously.
(2) The parameters of constitutive model in the whole range of deformation conditions were determined by linear fitting test data, such as the apparent activation energy (Q) was estimated to be on average 144.072 KJmol−1, the stress exponents (n) were measured to be 5.386.
Online since: January 2011
Authors: Ashish D. Diwan, Philip Boughton, Tamer S. Sabet, Ronald Ho, Jonathan Choi
Data Analysis.
Data was analysed using the SPSS software package (version 13.0).
Data is represented as mean percentage difference with 95% Confidence Bars.
Data is represented as mean percentage difference with 95% Confidence Bars.
Data is represented as mean percentage difference with 95% Confidence Bars.
Data was analysed using the SPSS software package (version 13.0).
Data is represented as mean percentage difference with 95% Confidence Bars.
Data is represented as mean percentage difference with 95% Confidence Bars.
Data is represented as mean percentage difference with 95% Confidence Bars.
Online since: February 2011
Authors: Jian Feng Chen
In order to study the load-bearing properties of butt-welded connection of steel structure post fire, the strength design value of weld connection post-fire is proposed based on the experimental data and theoretical analysis.
Strength degradation regularity of the weld connection post fire is tested by the author and reduction coefficient for tensile strength of butt-welded connection is given in the reference [3,4].
When the reduction coefficient is used to check the strength of the weld connection post fire, the strength design value of weld connection and calculation method for strength of weld after high temperature are needed to be studied further more.
(10) Where, N ——The axial tensile or compressive force; lw ——Length of the weld; t ——The smaller thickness of connectors in butt-welded joint; The thickness of web in T-shaped joint; ——Reduction coefficient for tensile strength of butt-welded joint after high temperature cooling; ,——Design value of tensile, compressive strength of butt-welded connection before fire.
Strength degradation regularity of the weld connection post fire is tested by the author and reduction coefficient for tensile strength of butt-welded connection is given in the reference [3,4].
When the reduction coefficient is used to check the strength of the weld connection post fire, the strength design value of weld connection and calculation method for strength of weld after high temperature are needed to be studied further more.
(10) Where, N ——The axial tensile or compressive force; lw ——Length of the weld; t ——The smaller thickness of connectors in butt-welded joint; The thickness of web in T-shaped joint; ——Reduction coefficient for tensile strength of butt-welded joint after high temperature cooling; ,——Design value of tensile, compressive strength of butt-welded connection before fire.
Online since: September 2014
Authors: Shi Gang Wang, Feng Juan Wang, Bo Yu Zhao
The simulation data and conclusion supply the basis for the actual processing.
The core head Ball Drawing Connecting rod Winding core heard Steel ring turning Core head turning Sizing die Steel ring The outer membrane Fig. 1 The principle of ball spinning forming Before forming the pipe blank, for the annealed light tube, first of all, through the floating mandrel diameter reduction of drawing, but traveling core head due to the axial force and different from the usual thinning, reducing floating mandrel drawing, the drawing force requirements as small as possible.
Ball feed 3 mm/r, reduction of 0.16 mm.
Table 3 Simulation parameters Spinning speed (r/min) Ball diameter (mm) Drawing speed (m/min) The number of ball Load (mm/r) Reduction (mm) 8000, 12000 18000, 24000 8 80 6 3 0.16 Fig. 3 Equivalent stress and strain (8000 r/min) Fig. 4 Equivalent stress and strain (12000 r/min) Fig. 5 Equivalent stress and strain (18000 r/min) Fig. 6 Equivalent stress and strain (24000 r/min) Through Fig. 3 to Fig.6 different spinning speed to form the inner straight groove tube stress, strain distribution were analyzed, effects of different spinning speed can be obtained in the straight groove tube high-speed ball spinning.
The core head Ball Drawing Connecting rod Winding core heard Steel ring turning Core head turning Sizing die Steel ring The outer membrane Fig. 1 The principle of ball spinning forming Before forming the pipe blank, for the annealed light tube, first of all, through the floating mandrel diameter reduction of drawing, but traveling core head due to the axial force and different from the usual thinning, reducing floating mandrel drawing, the drawing force requirements as small as possible.
Ball feed 3 mm/r, reduction of 0.16 mm.
Table 3 Simulation parameters Spinning speed (r/min) Ball diameter (mm) Drawing speed (m/min) The number of ball Load (mm/r) Reduction (mm) 8000, 12000 18000, 24000 8 80 6 3 0.16 Fig. 3 Equivalent stress and strain (8000 r/min) Fig. 4 Equivalent stress and strain (12000 r/min) Fig. 5 Equivalent stress and strain (18000 r/min) Fig. 6 Equivalent stress and strain (24000 r/min) Through Fig. 3 to Fig.6 different spinning speed to form the inner straight groove tube stress, strain distribution were analyzed, effects of different spinning speed can be obtained in the straight groove tube high-speed ball spinning.
Online since: January 2013
Authors: Zhao Lv
Second, in the stage of moderate earthquake, the data is calculated by adjusting the corresponding parameter values.
The structural computation model shown in Figure 1. 1.2 Calculation Parameters floors 5 Wind load the basic wind pressure In 50 years Earthquake Unidirectiona earthquake and accidental eccentricity (± 5%) Earthquake computing CQC, Elastic time-history analysis, Static elastoplastic analysis Earthquake direction x .y.z Live Load Reduction According to the standard Weight adjustment 1 Floor assumption Rigid floor Cycle reduction 0.9 Damping ratio 0.04 Stiffness enlarge 2 1.3 The Analysis of main calculation results The calculation results show that in the calculation of the 50 formation were not mainly to reverse the cycle of vibration, which can be judged the original main concrete structure due to increase steel reasons, the overall structure has enough torsional rigidity.
Specific parameter adjustment: the largest earthquake influence coefficient а take 0.46 earthquake amplification factor of 1; cycle take 1 reduction factor; the seismic level defined as the four; adopt the role of partial factor, material partial safety factor and the seismic capacity adjustment factor The strength of the material used the design value.The definition of other design parameters are the same as in the design of small earthquakes. 2.2The Analysis of main calculation results In earthquakes, structure in the X direction, the first floor shear 95451KN, is about a small earthquake of 2.3 times,In the Y direction first floor shear 76323KN, and is a small earthquake of 2.1 times.
The structural computation model shown in Figure 1. 1.2 Calculation Parameters floors 5 Wind load the basic wind pressure In 50 years Earthquake Unidirectiona earthquake and accidental eccentricity (± 5%) Earthquake computing CQC, Elastic time-history analysis, Static elastoplastic analysis Earthquake direction x .y.z Live Load Reduction According to the standard Weight adjustment 1 Floor assumption Rigid floor Cycle reduction 0.9 Damping ratio 0.04 Stiffness enlarge 2 1.3 The Analysis of main calculation results The calculation results show that in the calculation of the 50 formation were not mainly to reverse the cycle of vibration, which can be judged the original main concrete structure due to increase steel reasons, the overall structure has enough torsional rigidity.
Specific parameter adjustment: the largest earthquake influence coefficient а take 0.46 earthquake amplification factor of 1; cycle take 1 reduction factor; the seismic level defined as the four; adopt the role of partial factor, material partial safety factor and the seismic capacity adjustment factor The strength of the material used the design value.The definition of other design parameters are the same as in the design of small earthquakes. 2.2The Analysis of main calculation results In earthquakes, structure in the X direction, the first floor shear 95451KN, is about a small earthquake of 2.3 times,In the Y direction first floor shear 76323KN, and is a small earthquake of 2.1 times.
Online since: October 2012
Authors: Hao Wu, Xu Jian Fang, Wan Jun Zhang, Hai Tao Xu
At first, by passing over the two week’s real data, a rent-return database is initialed.
Clustering analysis of data set aims at discovering smaller, more homogeneous groups from a large heterogeneous collection of data points and it is an important unsupervised classification technique used in identifying some inherent structure present in a set of objects.
The idea comes from partition technology according to data distribution.
The algorithm partition data points into K initial cluster, and calculate the initial cluster centers.
Krzanowski: Computational Statistics & Data Analysis(2005), series 49(4), 969–973
Clustering analysis of data set aims at discovering smaller, more homogeneous groups from a large heterogeneous collection of data points and it is an important unsupervised classification technique used in identifying some inherent structure present in a set of objects.
The idea comes from partition technology according to data distribution.
The algorithm partition data points into K initial cluster, and calculate the initial cluster centers.
Krzanowski: Computational Statistics & Data Analysis(2005), series 49(4), 969–973