Quantification of banding on printed corrugated board using spatial frequency analysis

The human visual system has an exceptional ability to detect systematic print mottle. One type of systematic print mottle is banding on printed corrugated board, resulting in a disturbing print defect. A new method that quantifies banding on printed corrugated board is proposed. The method is based on spatial frequency analysis, and the degree of banding is determined using a band‐pass filter range adapted to fit the flute wavelength and orientation of the acquired image of the printed board. The results for B‐flute corrugated board gave a correlation coefficient of 0.98 between the technical measurements and the subjective ratings. Methods of quantifying the banding on the different types of corrugated board available on the market are discussed. Copyright © 2005 John Wiley & Sons, Ltd.     

Semantic-based framework for personalised ambient media

The paper proposes a semantic-based metadata framework for personalised interaction with TV media in a connected home context. Our approach allows the current home media centres to go beyond the simple concept of electronic programme guides and to offer the users a personalised media experience in an ambient home environment. The user’s characteristics, preferences and context are used to personalise the user’s experience of viewing and interacting with multimedia content on different heterogeneous devices. The TV-Anytime specification provides the basis for the metadata framework for handling content from IP, digital broadcast, and Blu-ray disc sources.     

Development of a PM 10/PM 2.5 Cascade Impactor and In-Stack Measurements

Combustion and industrial processes are an important source of particles. Due to the new PM 10 and PM 2.5 standards for ambient air quality, a sampling system for PM 10/PM 2.5 in-stack measurements was designed and calibrated. In this new system, the exhaust gas is isokinetically sucked into a two stage impactor through the inlet of a plane filter device and the aerosol is fractionated in the particle size classes >10 w m, 10-2.5 w m, and <2.5 w m. Due to a relatively high volume flow (ca. 3.2 m 3 /h, depending on exhaust gas conditions), sampling times are kept short, e.g., 30 min for dust concentrations of 10 mg/m 3 . The impactor was calibrated in the laboratory and then operated at various industrial plants. Parallel measurements with identical devices showed average standard deviations of 3.1% (PM 10) and 3.4% (PM 2.5). Measurements of the cascade impactor together with the plane filter device gave plausible results and average PMx/TSP ratios of 0.49 (PM 2.5/TSP) and 0.78 (PM 10/TSP), showing a large variability for different processes. Elemental analysis using total-reflection X-ray fluorescence spectrometry, together with the size-fractionated sampling, proved to give characteristic patterns of the emitted aerosols, which can be used for a subsequent fingerprint modelling for source apportionment of ambient air pollution.     

Crack Patterns in Thin Polymer Layers

Summary: During the solidification of thin polymer layers different crack patterns can occur. There are several mechanisms of the development of regular crack defects and layer fractures. In case of self‐organization caused by Marangoni instability at the fluid layer surface the substrate can be periodically uncovered by spreading motions when dewetting hinders a back flow from the higher spots of the layer. Another type of crack patterns is generated from shrinkage processes and stress differences in the drying layer. Mostly these patterns are characterized by intersecting straight cracks. In this paper some examples of unusual shrinkage‐crack patterns in polymer layers are presented. Their propagation is independent on surface flow and surface deformations caused by the Marangoni effect, although the strength of polymer layers is impaired by the interfacial instability. Especially at layer edges or spots with thickness differences one can observe periodic wavy or circularly bend shrinkage‐crack structures. As a third type ramified surface defects are studied in thin layers. Often they only propagate at the layer surface.

Wavy shrinkage‐cracks in a PMMA layer with longish surface elevations.     

On the relationship between workflow models and document types

The best practice in information system development is to model the business processes that have to be supported and the database of the information system separately. This is inefficient because they are closely related. Therefore we present a framework in which it is possible to derive one from the other. To this end we introduce a special class of Petri nets, called Jackson nets, to model the business processes, and a document type, called Jackson types, to model the database. We show that there is a one-to-one correspondence between Jackson nets and Jackson types. We illustrate the use of the framework by an example.     

Rechtliche und gesellschaftliche Empfehlungen zur Gestaltung biometrischer Systeme

Zusammenfassung  Nach langj?hrigen Bemühungen in der biometrischen Standardisierung konnte nun — neben etlichen bereits ver?ffentlichten technischen Normen — auch der erste Teil des technischen Berichts zu rechtlichen und gesellschaftlichen Empfehlungen fertig gestellt werden. Er beinhaltet sowohl rechtliche als auch gesellschaftliche/soziale und verbraucherbezogene Aspekte für einen vertr?glichen Einsatz biometrischer Systeme in einem Sinne, dass Rechte und Pflichten der Beteiligten m?glichst ausgewogen berücksichtigt werden. Das Grundkonzept und wesentliche Gesichtspunkte daraus werden hier vorgestellt. Der zweite Teil, der zur Zeit entsteht, wird sich mit anwendungsspezifischen Empfehlungen befassen und auch konkrete biometrische Technologien betrachten. Dr. Astrid Schumacher befasst sich beim BSI mit technischrechtlichen Fragestellungen der Kommunikationssicherheit in Gesch?ftsprozessen und dem elektronischen Rechtsverkehr. Kristina Unverricht arbeitet für den Verbraucherrat des DIN Deutsches Institut für Normung e.V. und vertritt Endverbraucherinteressen in der Normung von Informations- und Kommunikationstechnologie und von Dienstleistungen.     

Local and global error estimations in linear structural dynamics

The study discusses the concept of error estimation in linear elastodynamics. Two different types of error estimators are presented. First ‘classical’ methods based on post-processing techniques are discussed starting from a semidiscrete formulation. The temporal error due to the finite difference discretization is measured independently of the spatial error of the finite element discretization. The temporal error estimators are applied within one time step and the spatial error estimators at a time point. The error is measured in the global energy norm. The temporal evolution of the error cannot be reflected. Furthermore the estimators can only evaluate the mean error of the whole spatial domain. As the second scheme local error estimators are presented. These estimators are designed to evaluate the error of local variables in a certain region by applying duality techniques. Local estimators are known from linear elastostatics and have later on been extended to nonlinear problems. The corresponding dual problem represents the influence of the local variable on the initial problem and may be related to the reciprocal theorem of Betti–Maxwell. In the present study this concept is transferred to linear structural dynamics. Because the dual problem is established over the total space–time domain, the spatial and temporal error of all time steps can be accumulated within one procedure. In this study the space–time finite element method is introduced as a single field formulation.     

The critical resolved shear stress of a superalloy as a combination of those of its γ matrix and γ′ precipitates

The critical resolved shear stress (CRSS), τ ₀, of peak-aged single crystals of the γ′-hardened commercial nickel-base superalloy NIMONIC 105 has been measured as a function of temperature T and orientation [hkl] of the compression axis. The same measurements have been carried out for the two constituent phases of NIMONIC 105: for the single-phase γ matrix and for the single-phase L1₂-long-range ordered γ′ phase. The value of T ranged from 283 to 1150 K, and the following orientations were studied: [001], [011], , and . The specimens were compression tested. The τ ₀ values of NIMONIC 105 and of the γ′ phase are anisotropic; the anisotropy of NIMONIC 105 is similar to that of the γ′ phase, but less pronounced. The τ ₀ of the γ phase is isotropic. The τ ₀ values of the γ and of the γ′ phase vary with T, whereas the τ ₀ of NIMONIC 105 is nearly independent of T for 400 K≤T≤1000 K. A model is presented that relates the function τ ₀ ([h, k, l], T) of NIMONIC 105 to the analogous functions of its constituent γ and γ′ phase.