scholarly journals NUMERICAL COMPARISON OF WAVE SYNTHESIS METHODS

1988 ◽  
Vol 1 (21) ◽  
pp. 6
Author(s):  
M.D. Miles ◽  
E.R. Funke
Keyword(s):  
Statistical Analysis ◽  
Time Domain ◽  
Synthesis Methods ◽  
Numerical Comparison ◽  
Comparison Study ◽  
Order Group ◽  
Wave Parameters ◽  
Long Wave ◽  
Standard Wave ◽  
Wave Synthesis

A numerical comparison study is carried out on a variety of methods for synthesizing pseudo-random Gaussian wave records for laboratory wave generation. Three nonharmonic superposition methods and three time domain filtering procedures are compared to a harmonic FFT technique. The synthesis methods are evaluated on the basis of a statistical analysis of 16 standard wave parameters obtained from a set of 200 wave records. Second order group-bounded long wave components are also investigated.

Amorphous track models: A numerical comparison study

2010 ◽  
Vol 45 (10) ◽  
pp. 1406-1409 ◽  
Author(s):  
S. Greilich ◽  
L. Grzanka ◽  
N. Bassler ◽  
C.E. Andersen ◽  
O. Jäkel
Keyword(s):  
Numerical Comparison ◽  
Comparison Study

scholarly journals COMPUTER VISION SYSTEM FOR COLOR MEASUREMENTS OF MEAT AND MEAT PRODUCTS: A REVIEW

2018 ◽  
Vol 3 (4) ◽  
pp. 4-15
Author(s):  
Igor B. Tomasevic
Keyword(s):  
Computer Vision ◽  
Statistical Analysis ◽  
Traditional Method ◽  
Vision System ◽  
Meat Products ◽  
Three Dimensions ◽  
Comparison Study ◽  
Computer Vision System ◽  
Color Measurements ◽  
Instrumental Values

Meat and meat products color evaluation ability of a computer vision system (CVS) is investigated by a comparison study with color measurements from a traditional colorimeter. A statistical analysis revealed significant differences between the instrumental values in all three dimensions (L*, a*, b*) between the CVS and colorimeter. The CVS-generated colors were more similar to the sample of the meat products visualized on the monitor, compared to colorimeter-generated colors in all (100 %) individual trials performed. The use of CVS should be considered a superior alternative to the traditional method for measuring color of meat and meat products.

Statistical analysis of inertial gravity wave parameters in the lower stratosphere over Northern China

2018 ◽  
Vol 52 (1-2) ◽  
pp. 563-575 ◽  
Author(s):  
Lei Chen ◽  
Jianchun Bian ◽  
Yi Liu ◽  
Zhixuan Bai ◽  
Shuai Qiao
Keyword(s):  
Statistical Analysis ◽  
Gravity Wave ◽  
Lower Stratosphere ◽  
Northern China ◽  
Wave Parameters

Diagnosis of the Tapping Process by Information Measure and Probability Voting Approach

1990 ◽  
Vol 112 (4) ◽  
pp. 319-325 ◽  
Author(s):  
Y. B. Chen ◽  
J. L. Sha ◽  
S. M. Wu
Keyword(s):  
Statistical Analysis ◽  
Success Rate ◽  
Conditional Probability ◽  
Time Domain ◽  
Information Gain ◽  
Weighting Function ◽  
Information Measure ◽  
Voting Scheme ◽  
The Time Domain ◽  
Efficiency And Reliability

A new method for the diagnosis of the tapping process using the information measure and multiple probability voting scheme is proposed. Considering the features of short cutting-duration and the large uncertainties existing in a tapping process, a set of indices based on the time-domain statistical analysis has been formed. These indices have then been evaluated and ranked using an algorithm that calculates the information gain of each index about the tapping process. The final classification decision can be made by a voting scheme based on the conditional probability functions for multiple indices. Furthermore, the information gains estimated in the index evolution process can be used as a weighting function during voting to improve efficiency and reliability. From a tapping test, which includes five different tapping conditions, a success rate of 95 percent has been achieved.

Large Containerships’ Fatigue Analysis due to Springing and Whipping

2016 ◽  
Author(s):  
Huilong Ren ◽  
Kaihong Zhang ◽  
Hui Li ◽  
Di Wang
Keyword(s):  
Statistical Analysis ◽  
Fatigue Damage ◽  
Time Domain ◽  
High Frequency ◽  
Influence Factor ◽  
Irregular Waves ◽  
Wave Loads ◽  
Analysis Method ◽  
Load Case ◽  
Factor Modification

As the sea transport demand increases constantly, marine corporations around the world are pursuing solutions with large scale and low cost, which makes ultra large containerships’ construction consequentially. Ultra large containerships are more flexible relatively, and the 2-node natural frequency can easily fall into the encountered spectrum frequency range of normal sea state. Meanwhile, as the speed of containerships is high and its large bow flare, when sailing with high speed, the bow structures may suffer severe slamming forces which can increase the design wave loads’ level and the fatigue damage. The importance of hydroelastic analysis of large and flexible containerships of today has been pointed out for structure design. Rules of Many Classification Society have made changes on design wave loads’ value and fatigue influence factor modification. The paper firstly introduced 3-D linear hydroelasticity theory to calculate the Response Amplitude Operator (RAO) in frequency domain, and then described 3-D nonlinear hydroelasticity theory to obtain the nonlinear wave loads time history in irregular waves in time domain, considering large amplitude motion and slamming force due to severe relative motion between ship hull and wave. Based on the theories, computer programs are made to conduct the calculations under specified load case, and some calculation and statistical results are compared with experimental results to verify the accuracy and stability of the programs secondly. The paper focused on the influence of springing and whipping on fatigue damages of 8500TEU and 10000TEU containerships in different loading cases, using spectrum analysis method and time domain statistical analysis method. The spectrum analysis method can calculate fatigue damage due to low-frequency wave loads and high-frequency springing separately, while the time domain statistical analysis can calculate fatigue damage due to the high-frequency damping whipping additionally, based on 3-D time domain nonlinear hydroelasticity wave loads’ time series simulation in irregular waves and rain flow counting method. Finally, discussions on influence factor of springing and whipping with different loading cases are made. Based on these two containerships in example, the fatigue damage due to whipping can be the same as the fatigue damage due to springing and even sometimes can be larger than the springing damage. According to the wave loads influence factor, the fatigue assessment of different position on midship section is done on the basis of nominal stress. Besides, some suggestions on calculating load case selection are made to minimize the quantity of work in frequency and time domain. Thus the tools for fatigue influence factor modification are provided to meet the demand of IACS’ UR[1].

scholarly journals STATISTICAL ANALYSIS OF ACOUSTIC WAVE PARAMETERS NEAR SOLAR ACTIVE REGIONS

2016 ◽  
Vol 827 (2) ◽  
pp. 140 ◽  
Author(s):  
M. Cristina Rabello-Soares ◽  
Richard S. Bogart ◽  
Philip H. Scherrer
Keyword(s):  
Statistical Analysis ◽  
Acoustic Wave ◽  
Active Regions ◽  
Wave Parameters ◽  
Solar Active Regions

Selecting the Performance Weights for the μ and H∞ Synthesis Methods for SISO Regulating Systems

1996 ◽  
Vol 118 (1) ◽  
pp. 126-131 ◽  
Author(s):  
M. A. Franchek
Keyword(s):  
Time Domain ◽  
Synthesis Methods ◽  
Single Input Single Output ◽  
Hard Time ◽  
Single Output ◽  
Single Input ◽  
Performance Problem ◽  
Plant Uncertainty ◽  
Step Disturbance ◽  
Domain Constraints

Presented in this paper is a method in which the performance weights W1(s) and W2(s) of the robust performance problem and the H∞ optimization problem can be chosen to directly enforce hard time domain constraints. The class of systems addressed are single-input-single-output (SISO) regulating systems required to maintain the output within a prespecified time domain tolerance despite (i) plant uncertainty, (ii) an external step disturbance, and (iii) actuator output saturation. The performance weights are extracted from the feedback configuration and facilitate performance maximization.

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