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This model makes it possible to retain the basic TWI analysis methods without restricting the interferometer model to the black-box model. While, for the black-box model approaches, the above-mentioned approximation method used to determine the OPDs is applied, the method designed at PTB allows raytracing and rayaiming methods to be used throughout the complete physical model. As a result, the implementation of the TWI model employed at PTB depends on adaptable physical parameters of the optical system rather than on a black-box model. This procedure facilitates the establishment of traceability and provides a physical understanding of the measurement system, as the ray paths can be visualized within the complete physical interferometer model. Furthermore, mechanical and other physical influence parameters can very efficiently be integrated into a simulation of the measurement system to allow their influence on the reconstruction result to be investigated.
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As it might be expected, most European initiatives within the study were initially formed among NMIs and DIs in those European countries with significant interest in specific topics driven by national industrial needs. The participating countries are typically only European countries except for the JCTLM, which has become a global network. Successful initiatives can be considered those that have sustained activity with an impact lasting well beyond the original projects. One example is the European Society for Precision Engineering and Nanotechnology (euspen) [33]. Initially funded by the EC’s Coordination and Support Actions programme [34], euspen was founded as a limited company and incorporated as a Charity under UK law in 1999, currently having 750 members representing 30 countries from all over the world. Common factors in initiatives that lasted well in excess of a typical 3 year formative project were observed.
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Each nation has a robust national measurement system (NMS),comprising of a network of laboratories, calibration facilities and standardsand accreditation and standardization bodies as a part of nationalquality infrastructure. The NMS can be described as the technical and organizational infrastructure which ensures a consistent and internationally recognized basis for traceable measurements to the SI units. CSIR-National Physical Laboratory (CSIR-NPL), the National Metrology Institute of India is the custodian of national measurement standards in India; Legal Metrology Department formulates the rules and regulations and enforces the metrology for trade and commerce, the Bureau of Indian Standards (BIS) normally deals with documentary standards of products and services while accreditation body, National Accreditation Board of Testing and Calibration Laboratories (NABL) as part of Quality Council of India (QCI) grants the accreditation certications to testing and calibration laboratories in the country.
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….During the design phase, the spherical roof and the radial grids were parametrically controlled and carefully considered to arrive at the final desired shape and layout of the terminal. The use of the Rhino 3D modeling platform and associated Grasshopper visual programming plug-in — both developed by Robert McNeel & Associates, of Seattle — enabled the Walter P Moore team to examine various options simultaneously to ensure synergy between the architectural intent and the structural design.
One of the greatest design challenges was realizing the architect’s vision of sweeping open spaces within the geometry of the structure while staying within the budget. As a result, multiple rounds of value engineering led to numerous design changes throughout the project. The parametric model was an invaluable tool in avoiding delays. For example, the roof geometry of the terminal building and the transition to the roof of the concourses were parametrically modeled and adjusted as the architect developed the preferred form.….