The role of stray light modeling and analysis in telescope system engineering, performance assessment, and risk abatement

2010 ◽  
Author(s):  
Richard N. Pfisterer ◽  
K. Scott Ellis ◽  
Stephen M. Pompea
Keyword(s):  
Performance Assessment ◽  
System Engineering ◽  
Stray Light ◽  
Modeling And Analysis ◽  
Telescope System ◽  
Light Modeling

scholarly journals Probabilistic Performance Assessment vs. the Safety Case Approach

MRS Advances ◽  
2019 ◽  
Vol 4 (17-18) ◽  
pp. 987-992
Author(s):  
François Diaz-Maurin ◽  
Rodney C. Ewing
Keyword(s):  
Performance Assessment ◽  
Uncertainty Quantification ◽  
International Community ◽  
Regulatory Framework ◽  
Geologic Repository ◽  
Large Uncertainty ◽  
Safety Case ◽  
The Face ◽  
The U.S

ABSTRACTThe “safety case” approach has been developed to address the issue of evaluating the performance of a geologic repository in the face of the large uncertainty that results for evaluations that extend over hundreds of thousands of years. This paper reviews the concept of the safety case as it has been defined by the international community. We contrast the safety case approach with that presently used in the U.S. repository program. Especially, we focus on the role of uncertainty quantification. There are inconsistencies between the initial proposal to dealing with uncertainties in a safety case and current U.S. practice. The paper seeks to better define the safety case concept so that it can be usefully applied to the regulatory framework of the U.S. repository program.

scholarly journals Iridescent structural colour production in male blue-black grassquit feather barbules: the role of keratin and melanin

2009 ◽  
Vol 6 (suppl_2) ◽  
Author(s):  
Rafael Maia ◽  
João Victor O Caetano ◽  
Sônia N Báo ◽  
Regina H Macedo
Keyword(s):  
Thin Film ◽  
Natural Variation ◽  
Single Layer ◽  
Coherent Scattering ◽  
Interspecific Variation ◽  
Stray Light ◽  
Main Role ◽  
Minimum Number ◽  
Keratin Layer

Iridescent coloration plays an important role in the visual communication system of many animal taxa. It is known that iridescent structural colours result from layers of materials with different refractive indexes, which in feathers usually are keratin, melanin and air. However, the role of these materials in the production of structural iridescent coloration is still poorly documented. Despite the great interspecific variation in the organization of such structures in bird plumage, melanin layers are usually considered too opaque, suggesting its main role is to delineate the outermost keratin layer and absorb incoherently scattered stray light. We combined spectrometry, electron microscopy and thin-film optical modelling to describe the UV-reflecting iridescent colour of feather barbules of male blue-black grassquits ( Volatinia jacarina ), characterized by a keratin layer overlying a single melanin layer. Our models indicate that both the keratin and the melanin layers are essential for production of the observed colour, influencing the coherent scattering of light. The melanin layer in some barbules may be thin enough to allow interaction with the underlying keratin; however, individuals usually have, on an average, the minimum number of granules that optimizes absorbance by this layer. Also, we show that altering optical properties of the materials resulted in better-fitting models relative to the empirically measured spectra. These results add to previous findings concerning the influence of melanin in single-layer iridescence, and stress the importance of considering natural variation when characterizing such photonic structures.

Effects of Data Envelopment Analysis on Performance Assessment

2018 ◽  
pp. 557-581
Author(s):  
Heinz Ahn ◽  
Nadia Vazquez Novoa
Keyword(s):  
Data Envelopment Analysis ◽  
Financial Performance ◽  
Performance Assessment ◽  
Performance Appraisal ◽  
Efficiency Score ◽  
Data Envelopment ◽  
Financial Assessment ◽  
Dea Efficiency ◽  
Controlling Processes

This paper examines the Data Envelopment Analysis (DEA) methodology from a cognitive perspective. Specifically, it analyzes (a) the role of DEA scores as an overall efficiency measure and (b) to what extent the presence of DEA scores for a non-financial performance appraisal influences a posterior financial performance assessment. The study confirms that the efficiency score acts as a strong performance marker when deciding on which decision making units (DMUs) should be awarded for their non-financial performance. Furthermore, it shows that the results of the non-financial performance evaluation may act as an anchor which significantly influences a posterior financial assessment. These insights have practical consequences for planning, reporting, and controlling processes that incorporate DEA efficiency scores.

Performance Evaluation Methods for Microgrippers

2014 ◽  
Author(s):  
Serena Ruggeri ◽  
Gianmauro Fontana ◽  
Irene Fassi ◽  
Giovanni Legnani
Keyword(s):  
Performance Evaluation ◽  
Performance Assessment ◽  
Evaluation Methods ◽  
Preliminary Survey ◽  
Quantitative Methodology ◽  
Performance Indices ◽  
Task Requirements ◽  
Different Types ◽  
Definition Of

In precise manipulation and assembly of components with sub-millimetric dimensions, the role of the gripping tools is fundamental. In the literature, many different types of the so-called microgrippers have been presented, based on different working principles, to cope with the issues related to the gripping, the handling and the release of different micro-components. Depending on the component properties, the task requirements and the system constraints, a microgripper could be more suitable than another and allow the achievement of higher performance. However, the performance assessment of the microgrippers lacks of a standardized and quantitative methodology. Many authors declare the good capabilities of their tools in a qualitative way or according to the results obtained executing specific and different tasks. For this reason, it is often difficult to compare different microgrippers and estimate the actual results that can be obtained e.g. in the gripping or the release of a component. In this context, after a preliminary survey of the adopted approaches in literature and of their meaning, this paper investigates the conception and formalization of methods and procedures to evaluate the performance of a generic microgripper and the definition of standard performance indices to support the presentation of the microgripper characteristics.

The Role of Laboratory Experiments in Engineering Education

2008 ◽  
Author(s):  
Alon Gany
Keyword(s):  
Engineering Education ◽  
Laboratory Experiments ◽  
Design Problems ◽  
Modeling And Analysis ◽  
Professional Career ◽  
Engineering Design Problems ◽  
Course Material ◽  
Advanced Stages ◽  
Research Students

The role of students experience in laboratory tests as a part of their engineering education is discussed. Nowadays, when computer simulations become an important tool in engineering design, problems solution, and research, students may loose the touch of real-world hardware and challenges. Hence, exposure to experimental work is very significant. It is proposed that at the advanced stages of the first degree studies, experiments related to specific courses will be incorporated as a part of the course material. It is also believed that in studies towards higher degrees, the combination of experimental research with theoretical modeling and analysis is an excellent introduction for the future professional career.

Stray Light Analysis of Solar Photoelectric Detection System on Space Target

2012 ◽  
Vol 466-467 ◽  
pp. 196-200
Author(s):  
Ling Yin Li ◽  
Yi Fan Wang ◽  
Xiao Gang San
Keyword(s):  
Mechanical Model ◽  
Detection System ◽  
Stray Light ◽  
Coating Technology ◽  
Detection Systems ◽  
Geometry Model ◽  
Photoelectric Detection ◽  
System Requirements ◽  
System Geometry ◽  
Telescope System

Most conventional spacious solar photoelectric detection systems suffer from unexpected stray light. This paper demonstrates the effects on photoelectric detection system bring out by stray light. On this foundation, build up evaluation index of stray light system, to search the reasonable programme to eliminating stray light. A detailed telescope system geometry model was created, and scatter models were create for telescope and enclosure components. By the means of designing the structure of main baffle, baffle vane and the coating technology. In order to verify the prosperity of structure that designed, we utilizes software to analysis opto-mechanical model. we utilizes software to analysis opto-mechanical model. The simulations show that point source transmittance of the system is thus reduced by up to two orders of magnitude between 10-8 and 10-10. Meanwhile, the experiment obtains clean detection data which satisfies the system requirements. Stray light has been suppressed effectually, and so measurement precision was improved from detection graphics.

The role of telescopic stray light in limb-darkening scans obtained in April 1981 (and later)

Solar Physics ◽  
1990 ◽  
Vol 126 (1) ◽  
pp. 47-52 ◽  
Author(s):  
Heinz Neckel ◽  
Dietrich Labs
Keyword(s):  
Stray Light ◽  
Limb Darkening

Ghosting and stray-light performance assessment of the Landsat Data Continuity Mission's (LDCM) Operational Land Imager (OLI)

2013 ◽  
Author(s):  
Philip W. Dabney ◽  
Raviv Levy ◽  
Lawrence Ong ◽  
Eugene Waluschka ◽  
Frank Grochocki
Keyword(s):  
Performance Assessment ◽  
Stray Light ◽  
Landsat Data ◽  
Data Continuity

Conclusions from an Nea Workshop: The Role of Phenomenological Sorption Modelling in Performance Assessment of RadioactiveWaste Disposal Systems

1983 ◽  
Vol 26 ◽  
Author(s):  
A.B. Muller ◽  
D. Langmuir ◽  
I. Neretnieks
Keyword(s):  
Performance Analysis ◽  
Performance Assessment ◽  
Systems Design ◽  
Sorption Process ◽  
Surface Ionization ◽  
Natural Environments ◽  
Far Field ◽  
Degree Of Confidence ◽  
Site Characterisation

ABSTRACTTo give due credit to the barrier of the far field geologic environment in many host media it is necessary to account for sorption processes. The ultimate impact of sorption modelling will be in helping to define the degree of confidence that may be placed on geochemical retardation occurring in this barrier. For those involved in site characterisation, systems' design, design implementation and regulation, this confidence is best derived from a combination of a fundamental phenomenological understanding of the sorption process with empirical observations of sorption in natural environments. Neither alone is adequate. By performing a few additional measurements during classical Ko experiments, the data necessary for the more fundamental models, such as that of double-layer or surface ionization and complexation, may also be provided. The basis of these models and their integration into broader performance analysis are outlined in the context of how this maximises confidence in the geologic barrier of critically concerned groups.

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