Complete analysis of photoelastic fringe patterns using two wavelengths

2002 ◽  
Author(s):  
Terry Y. Chen ◽  
S. H. Tsao ◽  
H. L. Lee
Keyword(s):  
Complete Analysis ◽  
Fringe Patterns

Rapid Reflective Facet Characterization Using Fringe Reflection Techniques

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Charles E. Andraka ◽  
Scott Sadlon ◽  
Brian Myer ◽  
Kirill Trapeznikov ◽  
Christina Liebner
Keyword(s):  
Automotive Industry ◽  
Target Location ◽  
Complete Analysis ◽  
Surface Slope ◽  
Fringe Analysis ◽  
Reflective Mirror ◽  
Facet Analysis ◽  
Shape Determination ◽  
Fringe Patterns ◽  
Rapid Characterization

Reflective mirror facets for concentrating solar power (CSP) systems have stringent requirements on the surface slope accuracy in order to provide adequate system performance. This paper presents a tool that can fully characterize facets quickly enough for 100% inspection on a production line. A facet for a CSP system, specifically a dish concentrator has a parabolic design shape. This shape will concentrate near-parallel rays from the sun to a point (or a line for trough systems). Deviations of surface slope from the design shape impact the performance of the system, either losing power that misses the target or increasing peak fluxes to undesirable levels. During development or production, accurate knowledge of facet defects can lead to improvements to lower cost or improve performance. The reported characterization system, SOFAST (Sandia Optical Fringe Analysis Slope Tool), has a computer-connected camera that images the reflective surface, which is positioned so that it reflects an active target, such as an LCD screen, to the camera. A series of fringe patterns are displayed on the screen while images are captured. Using the captured information, the reflected target location of each pixel of mirror viewed can be determined, and thus through a mathematical transformation, a surface normal map can be developed. This is then fitted to the selected model equation, and the errors from design are characterized. While similar approaches have been explored, several key developments are presented here. The combination of the display, capture, and data reduction in one system allows rapid characterization. An “electronic boresight” approach is utilized to accommodate physical equipment positioning deviations, making the system insensitive to setup errors. Up to 1.5 × 106 points are characterized on each facet. Finally, while prior automotive industry commercial systems resolve the data to shape determination, SOFAST concentrates on slope characterization and reporting, which is tailored to solar applications. SOFAST can be used for facet analysis during development. However, the real payoff is in production, where complete analysis is performed in about 10 s. With optimized coding, this could be further reduced.

TOURIST BUSINESS DEVELOPMENT IN UKRAINE

2019 ◽  
pp. 39-46
Author(s):  
Stefania Mosiuk ◽  
Igor Mosiuk ◽  
Vladimir Mosiuk
Keyword(s):  
National Economy ◽  
Methodological Approach ◽  
Business Development ◽  
Tourism Industry ◽  
The State ◽  
Complete Analysis ◽  
Resource Potential ◽  
The World ◽  
Potential Resource ◽  
Favorable Conditions

The purpose of the article is to analyze and substantiate the development of tourism business in Ukraine as a priority component of the national economy. The methodology of this study is to use analytical, spatial, geographical, cultural and other methods. This methodological approach provided an opportunity to carry out a complete analysis of the state of the tourism industry of the state and to draw some conclusions.The scientific novelty lies in the coverage of the real and potential resource potential for the development of the recreational and tourism sphere in Ukraine, detailing the measures for the country ‘s entry into the world tourist market. Conclusions. Analyzing the state and prospects of tourism business development in Ukraine, it should be noted that this industry is one of the priority areas for improving the economy of the country. Historical, cultural – ethnographic, gastronomic, sanatorium and resort potentials of the country will lead the country into world leaders of the tourism industry when creating favorable conditions for investment and proper marketing.

Dosimetry and optimization in digital radiography based on the contrast-detail resolution

2018 ◽  
Vol 6 (3) ◽  
Author(s):  
Wilson Otto Gomes Batista ◽  
Alexandre Gomes De Carvalho
Keyword(s):  
Image Quality ◽  
Inverse Image ◽  
Point Of View ◽  
Complete Analysis ◽  
Portable Devices ◽  
Evaluation Tool ◽  
Air Kerma ◽  
Direct Radiography ◽  
Definition Of ◽  
Entrance Surface Air Kerma

Contrast-detail (C-D) curves are useful in evaluating the radiographic image quality in a global way. The objective of the present study was to obtain the C-D curves and the inverse image quality figure. Both of these parameters were used as an evaluation tool for abdominal and chest imaging protocols. The C-D curves were obtained with the phantom CDRAD 2.0 in computerized radiography and the direct radiography systems (including portable devices). The protocols were 90 and 102 kV in the range of 2 to 20 mAs for the chest and 80 kV in the range of 10 to 80 mAs for the abdomen. The incident air kerma values were evaluated with a solid state sensor. The analysis of these C-D curves help to identify which technique would allow a lower value of the entrance surface air kerma, Ke, while maintaining the image quality from the point of view of C-D detectability. The results showed that the inverse image quality figure, IQFinv, varied little throughout the range of mAs, while the value of Ke varied linearly directly with the mAs values. Also, the complete analysis of the curves indicated that there was an increase in the definition of the details with increasing mAs. It can be concluded that, in the transition phase for the use of the new receptors, it is necessary to evaluate and adjust the practised protocols to ensure, at a minimum, the same levels of the image quality, taking into account the aspects of the radiation protection of the patient.

Stress Analysis of Tire Sections

1996 ◽  
Vol 24 (4) ◽  
pp. 349-366 ◽  
Author(s):  
T-M. Wang ◽  
I. M. Daniel ◽  
K. Huang
Keyword(s):  
Finite Element ◽  
Internal Pressure ◽  
Stress Analysis ◽  
Strain Analysis ◽  
Experimental Stress ◽  
Inflation Pressure ◽  
Substantial Agreement ◽  
Finite Element Stress Analysis ◽  
Strain Components ◽  
Fringe Patterns

Abstract An experimental stress-strain analysis by means of the Moiré method was conducted in the area of the tread and belt regions of tire sections. A special loading fixture was designed to support the tire section and load it in a manner simulating service loading and allowing for Moiré measurements. The specimen was loaded by imposing a uniform fixed deflection on the tread surface and increasing the internal pressure in steps. Moiré fringe patterns were recorded and analyzed to obtain strain components at various locations of interest. Maximum strains in the range of 1–7% were determined for an effective inflation pressure of 690 kPa (100 psi). These results were in substantial agreement with results obtained by a finite element stress analysis.

Degenerate Diffusion Operators Arising in Population Biology (AM-185)

2017 ◽  
Author(s):  
Charles L. Epstein ◽  
Rafe Mazzeo
Keyword(s):  
Adjoint Operator ◽  
Integral Kernel ◽  
Mathematical Finance ◽  
Elliptic Operators ◽  
Complete Analysis ◽  
Time Behavior ◽  
Degenerate Elliptic Operators ◽  
Regularity Properties ◽  
Degenerate Elliptic ◽  
Mathematical Foundations

This book provides the mathematical foundations for the analysis of a class of degenerate elliptic operators defined on manifolds with corners, which arise in a variety of applications such as population genetics, mathematical finance, and economics. The results discussed in this book prove the uniqueness of the solution to the martingale problem and therefore the existence of the associated Markov process. The book uses an “integral kernel method” to develop mathematical foundations for the study of such degenerate elliptic operators and the stochastic processes they define. The precise nature of the degeneracies of the principal symbol for these operators leads to solutions of the parabolic and elliptic problems that display novel regularity properties. Dually, the adjoint operator allows for rather dramatic singularities, such as measures supported on high codimensional strata of the boundary. The book establishes the uniqueness, existence, and sharp regularity properties for solutions to the homogeneous and inhomogeneous heat equations, as well as a complete analysis of the resolvent operator acting on Hölder spaces. It shows that the semigroups defined by these operators have holomorphic extensions to the right half plane. The book also demonstrates precise asymptotic results for the long-time behavior of solutions to both the forward and backward Kolmogorov equations.

Analysis of Delta Iddq Soft Fails on Pass Chips

2006 ◽  
Author(s):  
I. Österreicher ◽  
S. Eckl ◽  
B. Tippelt ◽  
S. Döring ◽  
R. Prang ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Failure Mode ◽  
Photon Emission ◽  
Complete Analysis ◽  
Functional Tests ◽  
Analysis Techniques ◽  
Atomic Force ◽  
Current Consumption ◽  
Emission Microscopy ◽  
Failure Localization

Abstract Depending on the field of application the ICs have to meet requirements that differ strongly from product to product, although they may be manufactured with similar technologies. In this paper a study of a failure mode is presented that occurs on chips which have passed all functional tests. Small differences in current consumption depending on the state of an applied pattern (delta Iddq measurement) are analyzed, although these differences are clearly within the usual specs. The challenge to apply the existing failure analysis techniques to these new fail modes is explained. The complete analysis flow from electrical test and Global Failure Localization to visualization is shown. The failure is localized by means of photon emission microscopy, further analyzed by Atomic Force Probing, and then visualized by SEM and TEM imaging.

Failure Analysis of Vertical Cavity Surface Emission Laser Diodes

2003 ◽  
Author(s):  
F. Siegelin ◽  
C. Brillert
Keyword(s):  
Failure Analysis ◽  
Complete Analysis ◽  
Cavity Surface ◽  
Dislocation Network ◽  
Plan View ◽  
Surface Emission ◽  
Optical Output ◽  
Vertical Cavity Surface ◽  
Vcsel Arrays ◽  
Vertical Cavity

Abstract A failure analysis case study for oxide confined vertical cavity surface emitting laser (VCSEL) arrays will be presented. The focus of this work is on devices failing with a reduced optical output due to a rapid degradation of the laser diode. The complete analysis flow will be shown, including electrical and optical characterization as well as detailed investigations on a nanometer scale. It is known that these fails are caused by dislocations. An advanced FIB preparation method enabled cross-section and plan view TEM to successfully visualize the complete extent of a dislocation network.

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