scholarly journals Analysis of Phase Evaluation Algorithms in an Interferometric Method for Static Deformation Measurement

10.14311/372 ◽  
2002 ◽  
Vol 42 (4) ◽  
Author(s):  
J. Novák
Keyword(s):  
Measurement Errors ◽  
Complex Analysis ◽  
Phase Measurement ◽  
Evaluation Process ◽  
Surface Shape ◽  
Interferometric Method ◽  
Phase Calculation ◽  
Calculation Algorithms ◽  
Negative Effect ◽  
Measurement And Evaluation

This article describes and analyses an interferometric method for measuring displacements and deformation. The method can be used for a very accurate evaluation of the change in the surface shape of structures used in industry. The paper proposes several multistep phase calculation algorithms and describes an automatic evaluation process using the measurement technique. A complex analysis is also performed of various factors that can have a negative effect on the practical measurement and evaluation process. An analysis is made of the proposed multistep phase calculation algorithms using the proposed error model. It is shown that the resulting phase measurement errors can be effectively reduced by using suitable phase calculation algorithms. The analysis can be applied for a complex comparison of the accuracy and stability of such algorithms.

scholarly journals New Phase Shifting Algorithms Insensitive to Linear Phase Shift Errors

10.14311/376 ◽  
2002 ◽  
Vol 42 (4) ◽  
Author(s):  
J. Novák
Keyword(s):  
Phase Shift ◽  
Evaluation Process ◽  
Phase Shifting ◽  
Linear Phase ◽  
Phase Errors ◽  
Arbitrary Phase ◽  
Phase Calculation ◽  
Calculation Algorithms ◽  
Phase Evaluation ◽  
New Phase

This article describes and analyses multistep algorithms for evaluating of the wave field phase in interferometric measurements using the phase shifting technique. New phase shifting algorithms are proposed, with a constant but arbitrary phase shift between captured frames of the intensity of the interference field. The phase evaluation process then does not depend on linear phase shift errors. A big advantage of the described algorithms is their ability to determine the phase shift value at every point of the detector plane. A detailed analysis of these algorithms with respect to main factors that affect interferometric measurements is then carried out. The dependency of these algorithms on phase shift values is also studied several phase calculation algorithms are proposed. These are compared with respect to the resulting phase errors.

Implementing TQM practices in Pakistani Higher Education Institutions

2016 ◽  
Vol 2 (1) ◽  
Author(s):  
Rizwan Ahmed ◽  
Syed Iftikhar Ali
Keyword(s):  
Higher Education ◽  
Process Control ◽  
Business Schools ◽  
Higher Education Institutions ◽  
Evaluation Process ◽  
Theoretical Framework ◽  
Educational Institutions ◽  
Higher Educational Institutions ◽  
Main Factors ◽  
Measurement And Evaluation

<span>Implementing TQM practices at the Higher Educational Institutions of Pakistan,<span> especially at the business schools, is relatively a new concept and it is in its initial stages.<span> The theoretical framework of this study is based upon the instrument that measures the<span> extent of TQM implementation in Higher Education Institutions. Based upon literature<span> review, the framework having 14 dimensions is used in this study. Exploratory Factor<span> Analysis (EFA) extracted 13 factors as the determinants of TQM Implementation in<span> business schools of Pakistan such as Stakeholders’ Focus, Recognition and Reward,<span> Measurement and Evaluation, Process Control and Improvement, Resources, Leadership,<span> Empowerment are some of the main factors as each of these factors are explaining more<span> than 5% of the variation in the data<br /><br class="Apple-interchange-newline" /></span></span></span></span></span></span></span></span></span></span>

scholarly journals Experimental investigation and numerical modelling of 3D radial compressor stage and influence of the technological holes on the working characteristics

2018 ◽  
Vol 180 ◽  
pp. 02060 ◽  
Author(s):  
Richard Matas ◽  
Tomáš Syka ◽  
Lukáš Hurda
Keyword(s):  
Experimental Investigation ◽  
Numerical Modelling ◽  
Research And Development ◽  
Evaluation Process ◽  
Rotor Blades ◽  
Compressor Stage ◽  
Experimental Facility ◽  
Radial Compressor ◽  
Measurement And Evaluation

The article deals with a description of results from research and development of a radial compressor stage with 3D rotor blades. The experimental facility and the measurement and evaluation process is described briefly in the first part. The comparison of measured and computed characteristics can be found in the second part. The last part of this contribution is the evaluation of the rotor blades technological holes influence on the compressor stage characteristics.

Combined effect of autocorrelation and measurement errors on the adaptive X¯ monitoring schemes

2020 ◽  
pp. 014233122093529 ◽  
Author(s):  
Sandile Charles Shongwe ◽  
Jean-Claude Malela-Majika
Keyword(s):  
Measurement Errors ◽  
Length Distribution ◽  
Real Life ◽  
Adaptive Designs ◽  
Combined Effect ◽  
Sampling Strategies ◽  
Run Length ◽  
Variable Sampling ◽  
Negative Effect ◽  
Run Length Distribution

For independent and identically distributed observations, and those with measurement errors only, the adaptive designs (i.e. variable sampling sizes (VSS), variable sampling intervals (VSI) and the latter two combined to form VSSI) have been thoroughly discussed. However, no research exists for processes under the combined effect of autocorrelation and measurement errors; thus, such adaptive Shewhart [Formula: see text] schemes are proposed. The Markov chain approach for adaptive designs are used to evaluate the run-length distribution properties with two special sampling strategies (i.e. s-skip and multiple measurements) incorporated to reduce the combined negative effect of autocorrelation and measurement inaccuracy. Using numerous run-length metrics, it is shown that the combination of the two sampling strategies with the VSSI design reduces this negative effect considerably and improves the detection ability of the [Formula: see text] scheme by a significant margin as compared with using the fixed sample size and sampling interval (FSSI), VSS and VSI designs. Autocorrelation level has a higher negative effect as compared with the measurement inaccuracy level. For high levels of autocorrelation ([Formula: see text]0.8), the s-skip strategy has little influence in reducing the negative effect; but the VSSI design maintains better performance than the other designs. Finally, a real-life example is used to illustrate its implementation.

Research on the Online Test Principle and Error Analysis of Aspherical Optical Surfaces

2013 ◽  
Vol 552 ◽  
pp. 434-439
Author(s):  
Da Mu ◽  
Quan Yong Li ◽  
Bo Qi Wu ◽  
Yu Nan Du
Keyword(s):  
High Precision ◽  
Precision Measurement ◽  
Measurement Errors ◽  
Surface Shape ◽  
High Precision Measurement ◽  
Aspherical Surface ◽  
Optical Surfaces ◽  
Advantages And Disadvantages ◽  
Swing Arm ◽  
Key Factor

For tFor t For tFor the imaging advantages of aspheric optical component, it has been widely used in the aviation, aerospace, defense and civilian high-technology. Aspherical surface shape test is a key factor restricted aspheric processing and a complex sophisticated testing techniques. The well known measurement methods are faulty. Each method has advantages and disadvantages; many methods cannot be used for online testing. In this paper，the geometric principle of a swing-arm profilometer as a novel method to measure aspherics is introduced．The deviation between the actual and the ideal of aspherical surface shape is confirmed by the high-precision measurement for the vertical height with a specific path on the aspherical optical surfaces. By adjusting the location of measuring devices to maintain the distance of rotation center to the center of workpiece equal to the length of swing-arm,we can achieve the measurement for the workpiece of different machining tool. The measurement system mainly consists of the lifting and landing system of the high-precision axis,the high-precision level turntable rotary table, the high rigidity measuring arm and the high precision measurement sensors. And the follow-up data processing puts forward a number of error correction models at the same time. The advantages of the measurement method are that the measurement sports is only a simple turning motion .It will be helpful to reduce measurement errors and improve the efficiency of measurement.

Interferometry-based measurements of oil-film thickness

2001 ◽  
Vol 215 (3) ◽  
pp. 243-259 ◽  
Author(s):  
O Marklund ◽  
L Gustafsson
Keyword(s):  
Film Thickness ◽  
Measurement Errors ◽  
Phase Measurement ◽  
Elastohydrodynamic Lubrication ◽  
Oil Film ◽  
Interferometric Phase ◽  
Experimental Apparatus ◽  
Colour Parameters ◽  
Computer Based ◽  
The Absolute

Measurement of the thickness of thin lubricant films separating rotating surfaces in elastohydrodynamic experiments presents some challenging problems. The nature of the experimental apparatus inhibits the use of most commonly applied interferometric phase measurement methods. Also the absolute thickness of the separating film must be determined, as opposed to relative distances that would be sufficient in most other measurement scenarios where interferometry methods are used. In this paper, computer-based analysis of interferograms recorded using an elastohydrodynamic lubrication Fitzeu interferometer (a so-called ball-and-disc apparatus) is discussed, the main objective being to extract the absolute oil-film thickness. Intensity based methods (most importantly, calibration look-up procedures where colour parameters from recorded dynamic interferograms are compared with table values corresponding to known film thicknesses, but also a phase measurement approach based on multi-channel interferometry using trichromatic light) are described. A discussion regarding compensation for measurement errors due to the pressure dependence of the refractive index of the lubricant is also included.

METHOD OF COMPREHENSIVE DATA ANALYSIS IN DIAGNOSTICS OF COMPLEX POWER EQUIPMENT

2021 ◽  
pp. 27-35
Author(s):  
Е.А. Абидова ◽  
А.Д. Данилов ◽  
А.Е. Дембицкий ◽  
А.В. Чернов
Keyword(s):  
Diesel Engine ◽  
Measurement Errors ◽  
Complex Analysis ◽  
Principal Component ◽  
Physical Nature ◽  
Technical Condition ◽  
Processing Scheme ◽  
Complete Control ◽  
Diagnostic Parameters ◽  
Initial Space

Предложен подход к диагностике сложного и габаритного оборудования на примере определения технического состояния дизельного двигателя. Отличительной особенностью дизельного двигателя является сложность конструкции, требующая применения комплекса методов для обеспечения полноты контроля и чувствительности при выявлении дефектов на ранних стадиях развития. Описана схема обработки данных, позволяющая повысить чувствительность при диагностике за счет комплексного анализа данных различной физической природы с использованием анализа сингулярного спектра. Повышение чувствительности обосновывается путем численного моделирования и обработки результатов измерения диагностических параметров в реальных производственных условиях. В качестве показателей чувствительности рассматриваются расстояния между координатами центров кластеров параметров исправного и неисправного состояния в исходном пространстве и в пространстве главных компонент. Продемонстрировано, что предлагаемый подход обеспечивает повышение чувствительности в условиях, когда влияние дефекта на диагностические параметры сопоставимо с действием случайных факторов в объекте диагностирования. Указанное повышение качества диагностирования достигается благодаря корреляции между параметрами за счет их представления в виде траекторных матриц. Помимо повышения чувствительности при выявлении дефектов также достигается и существенное сжатие информации, которая используется для определения состояния. Преимуществом предлагаемого подхода также является наглядная визуализация результатов The article suggests an approach to the diagnosis of complex and oversized equipment by the example of determining the technical condition of a diesel engine. A distinctive feature of the diesel engine is the complexity of the design, which requires the use of a set of methods to ensure complete control and sensitivity when detecting defects at early stages of development. We describe the data processing scheme, which allows you to increase the sensitivity in diagnostics due to the complex analysis of data of various physical nature using the principal component method. The increase in sensitivity is justified by numerical modeling and processing the results of measuring diagnostic parameters in real production conditions. Distances between coordinates of centers of clusters of parameters of serviceable and faulty state in initial space and in space of principal components are considered as indicators of sensitivity. We demonstrated that the proposed approach provides increased sensitivity in conditions where the effect of a defect on diagnostic parameters is comparable to measurement errors. The indicated improvement in the quality of diagnostics is achieved due to the correlation between the parameters due to their representation in the form of trajectory matrices. In addition to increasing sensitivity when detecting defects, significant compression of information that is used to determine the state is also achieved. The advantage of the proposed approach is also the vivid visualization of the results

Mapping the 2020 Slovak Parliamentary Election. Analysis of Spatial Support and Voter Transition

2020 ◽  
Vol 27 (3) ◽  
pp. 278-302 ◽  
Author(s):  
Jakub Lysek ◽  
Ľubomír Zvada ◽  
Michal Škop
Keyword(s):  
Complex Analysis ◽  
Geographic Area ◽  
Hierarchical Regression ◽  
Parliamentary Election ◽  
Left Wing ◽  
Ecological Inference ◽  
Electoral Support ◽  
Voter Transition ◽  
Negative Effect ◽  
Spatial Support

This contribution is a complex analysis of the geographic voting patterns in the 2020 Slovak parliamentary election using methods such as Geographically Weighted Regression, Hierarchical Regression Models, and Ecological Inference. It is focused on the winner of the 2020 parliamentary election, the populist OĽaNO, and on the loser, the traditional left-wing SMER-SD – within the context of electoral support and voter transition in comparison to the 2016 parliamentary election, and in part to the 2019 presidential election. The article contributes to the underdeveloped discourse relating to the spatial support of political parties in Slovakia and finds how the selected socio-economic indicators explain the varying voting patterns. The main finding is that Slovakia is an internally heterogeneous country. The socio-demographic factors have a differentiated (either positive or negative) effect on the electoral support for Slovakian parties. As a result, voting patterns differ not only between the western and eastern parts of the country but also between districts within a common geographic area or region. This reveals the complex set of dividing lines in the country and indicates future trends in Slovakian politics.

Application of an Optical Pyrometer to Newly Developed Industrial Gas Turbine

2012 ◽  
Author(s):  
Tomoki Taniguchi ◽  
Ryozo Tanaka ◽  
Yuji Shinoda ◽  
Masanori Ryu ◽  
Norbert Moritz ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Evaluation Process ◽  
Optical Pyrometer ◽  
Blade Surface ◽  
High Pressure Turbine ◽  
Low Pressure Turbine ◽  
Lower Temperature ◽  
Measurement And Evaluation ◽  
Industrial Gas Turbine ◽  
Engine Condition

Kawasaki Heavy Industries, Ltd (KHI) have developed a new industrial gas turbine, L30A. The turbine section composed of two-stage high pressure turbine and three-stage low pressure turbine. In the development period, a commercial pyrometer system was employed to measure blade temperatures under real engine condition. The pyrometer was equipped with an updated detector module and could measure lower temperature compared to the conventional one. Thus it could be used to measure all stages of blades with one pyrometer. The validity of the result was demonstrated by comparing the result with data obtained with other conventional techniques. With the pyrometer system the temperature distribution on the blade surface was easily available and cooling capabilities of blades were evaluated without taking much time. This paper describes the detail of measurement and evaluation process.

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