Model validation and model structure determination

This paper gives a tutorial overview of basic approaches for model validation and model structure determination.Work partially supported by the Swedish Research Council for Engineering Sciences under contract 98-654.     

Higher Order Barycentric Coordinates

In recent years, a wide range of generalized barycentric coordinates has been suggested. However, all of them lack control over derivatives. We show how the notion of barycentric coordinates can be extended to specify derivatives at control points. This is also known as Hermite interpolation. We introduce a method to modify existing barycentric coordinates to higher order barycentric coordinates and demonstrate, using higher order mean value coordinates, that our method, although conceptually simple and easy to implement, can be used to give easy and intuitive control at interactive frame rates over local space deformations such as rotations.     

Issues in nonlinear stochastic grey box identification

Grey box identification refers to the practice of identifying dynamical systems in model structures exploiting partial prior information. This contribution reviews a method for stochastic grey box identification and surveys experiences and lessons of applying it to a number of industrial processes. Issues to be addressed include advantages and costs of introducing stochastics into the model, the question of what contribution must be expected from the model designer as opposed to what can be formalized in computer algorithms, and an outlook on future plans to resolve present shortcomings.     

Efficient reconstruction from non-uniform point sets

We propose a method for non-uniform reconstruction of 3D scalar data. Typically, radial basis functions, trigonometric polynomials or shift-invariant functions are used in the functional approximation of 3D data. We adopt a variational approach for the reconstruction and rendering of 3D data. The principle idea is based on data fitting via thin-plate splines. An approximation by B-splines offers more compact support for fast reconstruction. We adopt this method for large datasets by introducing a block-based reconstruction approach. This makes the method practical for large datasets. Our reconstruction will be smooth across blocks. We give reconstruction measurements as error estimations based on different parameter settings and also an insight on the computational effort. We show that the block size used in reconstruction has a negligible effect on the reconstruction error. Finally we show rendering results to emphasize the quality of this 3D reconstruction technique.     

A GRL-compliant iStar extension for collaborative cyber-physical systems

Requirements Engineering - Collaborative cyber-physical systems are capable of forming networks at runtime to achieve goals that are unachievable for individual systems. They do so by connecting to...     

Comparison of different methods to determine the spreadability and firmness of processed cheese

Summary Current texture-measuring instruments and a recently developed measuring method (two-dimensional measuring of the force necessary to spread a sample) were compared in measuring the spreadability of processed cheese. How far subjective assessment by a qualified panel correlates with the instrumental results in determining spreadability and firmness was also investigated. Samples of processed cheese with various consistencies were measured by an Universal testing machine, a buttermeasuring instrument (DIN 10331), a rotational-type rheometer (oscillation mode) and a two-dimensional force measuring instrument. The evaluation of the results shows that an oscillating rheometer is most suitable to measure the spreadability of processed cheese; the correlation coefficient (r) between the dynamic Weissenberg number, calculated from parameters of the rheometer, and the subjective judgement by the panel wasr=0.91. For the determination of firmness the two-dimensional force measuring instrument is most suitable. The correlation coefficient between the parameter tangential energy (S _t) and the sensorially evaluated firmness wasr=0.95.

---

Vergleich verschiedener Bestimmungsmethoden für die Streichfähigkeit und Festigkeit von Schmelzkäse

Zusammenfassung Verschiedene gebräuchliche Meßinstrumente und ein neu entwickeltes Gerät zur zweidimensionalen Messung der Kräfte, die zum Ausstreichen einer Probe erforderlich sind, wurden vergleichend zur Charakterisierung der Streichfähigkeit von Schmelzkäse erprobt. Dabei wurde auch geprüft, inwieweit die subjektiven Beurteilungen eines qualifizierten Prüferpanels mit den Meßwerten für Streichfähigkeit und Festigkeit korrelierten. Gemessen wurde mit einer Universalprüfmaschine, dem Butterprüfgerät (DIN 10331), einem Rotationsrheometer und mit dem zweidimensional registrierenden Kraftmeßgerät. Dabei zeigte sich, daß das Rheometer im oscillierenden Modus die Streichfähigkeit am besten zu charakterisieren vermag. Die Korrelation zwischen den Rheometerwerten, berechnet als dynamische Weissenbergzahl, und den sensorisch ermittelten Werten für die Streichfähigkeit betrugr=0,91. Zur Bestimmung der Festigkeit ist das zweidimensional registrierende Kraftmeßgerät am besten geeignet, was sich in einem Korrelationskoeffizienten vonr=0,95 zwischen dem ParameterS _t und den im Sensoriktest ermittelten Werten für dieFestigkeit ausdrückt.

     

Overview of Tiber-II—Evolution toward an Engineering Test Reactor

TIBER II is designed to be a minimum size and cost candidate for an international Engineering Test Reactor. High-current density Nb₃Sn superconducting magnets with radiation-tolerant polymide insulation is combined with a minimum thickness tungsten inbored shield and a common, external vacuum boundary to minimize the inner radial build of the tokamak core. This results in a major radius of 3 m, compared to 5 m for previous ETR designs such as INTOR, with correspondingly lower costs expected. Cyclic stress fatigue limits the number of pulses so that steady-state current drive, based on a combination of neutral beams, lower hybrid and ECH, is designed to achieve reactor-relevant nuclear testing conditions (Fluence 3MW yr/m², rwall > 1 MW/m² in steady state).This report is abstracted from a more complete information document UCID-20863 with numerous authors. See Ref. l for complete credits.