Model-driven migration of supervisory machine control architectures

Supervisory machine control is the high-level control in advanced manufacturing machines that is responsible for the coordination of manufacturing activities. Traditionally, the design of such control systems is based on finite state machines. An alternative, more flexible approach is based on task-resource models. This paper describes an approach for the migration of supervisory machine control architectures towards this alternative approach. We propose a generic migration approach based on model transformations that includes normalisation of legacy architectures before their actual transformation. To this end, we identify a number of key concerns for supervisory machine control and a corresponding normalised design idiom. As such, our migration approach constitutes a series of model transformations, for which we define transformation rules. We illustrate the applicability of this model-driven approach by migrating (part of) the supervisory control architecture of an advanced manufacturing machine: a wafer scanner developed by ASML. This migration, towards a product-line architecture, includes a change in architectural paradigm from finite state machines to task-resource systems.     

Exploring the relation between visualizer-verbalizer cognitive styles and performance with visual or verbal learning material

A student might find a certain representational format (e.g., diagram, text) more attractive than other formats for learning. Computer technology offers opportunities to adjust the formats used in learning environments to the preferences of individual learners. The question addressed in the current study was: does the match between a student’s preference regarding the format of learning materials have any relation with performance when learning with a specific format? For example, do learners with a preference for visual materials indeed perform better with visual learning materials? In a study with a pre-test post-test design, 48 participants were randomly assigned to one of two conditions. Both conditions completed a mathematical learning task about combinatorics and probability theory. In one condition learning materials were mainly diagram-based in the other condition they were mainly text-based. Afterward, the relations between cognitive style (visualizers-verbalizers), cognitive abilities (e.g., spatial and verbal ability), and learning performance were examined. The findings showed that cognitive style and learning outcomes were unrelated, for example, learners with a preference for visual materials do not necessarily perform better with visual learning materials. Learning results seem to be influenced by cognitive ability (in particular spatial visualization) and the extent to which a format affords cognitive processing, rather than a match between used and preferred format. It is argued that students should not choose on the basis of their preference, because it might lead them to selecting a format that is less effective for learning.     

The role of scaffolding and motivation in CSCL

Recent findings from research into Computer-Supported Collaborative Learning (CSCL) have indicated that not all learners are able to successfully learn in online collaborative settings. Given that most online settings are characterised by minimal guidance, which require learners to be more autonomous and self-directed, CSCL may provide conditions more conducive to learners comfortable with greater autonomy. Using quasi-experimental research, this paper examines the impact of a redesign of an authentic CSCL environment, based upon principles of Problem-Based Learning, which aimed to provide a more explicit scaffolding of the learning phases for students. It was hypothesised that learners in a redesigned ‘Optima’ environment would reach higher levels of knowledge construction due to clearer scaffolding. Furthermore, it was expected that the redesign would produce a more equal spread in contributions to discourse for learners with different motivational profiles.     

Surrogate relaxation of a fuzzy multidimensional 0–1 knapsack model by surrogate constraint normalization rules and a methodology for multi-attribute project portfolio selection

In this paper, a multidimensional 0–1 knapsack model with fuzzy parameters is defuzzified using triangular norm (t-norm) and t-conorm fuzzy relations. In the first part of the paper, the surrogate relaxation models of the defuzzified models are developed, and the use of surrogate constraint normalization rules is proposed as the surrogate multipliers. A methodology is proposed to evaluate some surrogate constraint normalization rules proposed in the literature as well as one rule proposed in this paper. Three distance metrics are used to find the distance of fuzzy objective function from the surrogate models to the distance of fuzzy objective function from the original models. A numerical experiment shows that the rule proposed in this paper dominates the other rules considered in this paper for three distance metrics given the whole assumptions. In the second part of the paper, a methodology is proposed for multi-attribute project portfolio selection, and optimal solutions from the original defuzzified models as well as near-optimal solutions from their surrogate relaxation models are considered as alternatives. The aggregation of evaluation results is managed using a simple yet effective method so-called fuzzy Simple Additive Weighting (SAW) method. Then, the methodology is applied to a hypothetical construction project portfolio selection problem with multiple attributes.     

The glucosinolates sinigrin and progoitrin are important determinants for taste preference and bitterness of Brussels sprouts

The glucosinolates, sinigrin and progoitrin, are related to the bitterness observed in Brussels sprouts. The role of these glucosinolates in taste preference for Brussels sprouts (Brassica oleracea var gemmifera) was studied with two different consumer taste panels and an analytical panel. Four different taste trials were conducted between 1989 and 1995 to study the role of sinigrin and progoitrin on taste preference and bitterness of sprouts. Sinigrin and progoitrin correlated negatively with taste preference of sprouts when their combined content was higher than 2·2 g kg⁻¹. Under these conditions the overall preference for different Brussels sprouts cultivars, in two different trial designs, was accounted for, respectively, 64 (Novartis Seeds BV) and 86% (TNO) by the contents of the glucosinolates sinigrin and progoitrin. In two additional trials, in which the combined content of sinigrin and progoitrin of all cultivars was below 2·2 g kg⁻¹, no relationship between taste preference and the content of both glucosinolates was observed. In the latter trials the content of sinigrin and progoitrin was found to be correlated with bitterness (r²_multiple = 0·67 and 0·93, respectively) as assessed by an analytical panel. The results of the taste trials show that both bitterness and taste preference for sprouts are correlated with the content of sinigrin and progoitrin. Taste preference for sprouts is only correlated with sinigrin and progoitrin when their combined content exceeds 2·2 g kg⁻¹, while bitterness is correlated with both glucosinolates for the whole studied content range. © 1998 Society of Chemical Industry.     

Changes in lipid content,fatty acid composition and lipoprotein lipase activity in dry goat omental adipose tissue according to tissue site

Water and lipid contents, fatty acid distribution, and lipoprotein lipase activity were determined in 11 samples taken from theOmentum Majus of five dry Alpine goats. Samples were chosen to standardize sampling sites using geometric guide marks representative of different adipose tissue sites. Sample location explained between 20% and 30% of the total variance in water and lipid contents and in lipoprotein lipase activity, and from 5.5% to 45.4% of the total variance in fatty acid distribution. Increased sample thickness was associated with an increase in lipid content and in saturated fatty acid percentages. Samples taken in proximity of the omentum tissue attached to the rumen and abomasum had the highest content. We furthermore found that the levels of 18∶2n−6, 18∶1n−7, and of branched chain fatty acids were high close to a pila of the rumen which also corresponded to high lipoprotein lipase activity. Concomitant high levels of 16∶1n−7, 17∶1n−8, and 18∶1n−9 may reflect high levels of Δ9 desaturase activity.     

Effect of fermented feed on the susceptibility for Campylobacter jejuni colonisation in broiler chickens with and without concurrent inoculation of Salmonella enteritidis

Fermented liquid feed (FLF) protects broiler chickens against colonisation with Salmonella. While Campylobacter causes more disease cases in humans than Salmonella, the effect of FLF on Campylobacter was assessed. The fermented liquid feed is a moistened feed with a high number of lactobacilli, a high concentration of lactic acid, and a pH of 4. In three experiments Campylobacter was orally applied to individually housed 9-day-old broiler chickens. A significant reduction of susceptibility, as determined by cloacal swabs, was observed. At any moment where an animal has not started to shed Campylobacter yet, the probability to start shedding Campylobacter in a subsequent small time interval was nine times as high for the control chickens than for the animals that were fed FLF. FLF did not consistently change the Campylobacter colonisation level in the caeca. It was concluded that FLF could reduce the probability of introduction of Campylobacter in broiler flocks. In an experiment where some chickens were simultaneously inoculated with Salmonella enteritidis and Campylobacter, no interaction on susceptibility or caecal colonisation level was observed.     

Sur les coefficients de Hall et l'aimantation spontanée des films minces de nickel déposés et étudiés sous ultra-vide

A phenomonological theory of the Hall effect in ferromagnetics shows that, in contrast to the usual interpretation, the study of the experimental curve which represents the Hall resistivity versus the applied field does not permit the Hall coefficients R₀ and R₁ to be determined unless the exact value of the spontaneous magnetization M_s is known.

This theory is shown to fit qualitatively very well with the experimental results and assuming that M_s has the same value as in bulk nickel, the calculated values of R₀ and R₁ for thick films are in good agreement with the tabulated ones for bulk nickel.     

A Fast and Accurate UPLC Method for Analysis of Proteinogenic Amino Acids

A reliable and inexpensive method for the measurement of proteinogenic amino acids was developed. It allows the screening of large sample volumes that is important for current food and feed applications, but also for future biobased applications. The method is based on acid hydrolysis and automated pre-column derivatision in the injection needle of the autosampler using o-phthalaldehyde/ethanethiol reagent in combination with 9-fluorenylmethyl chloroformate. The calculated mean limit of detection and limit of quantification of pure amino acids were 2.3 and 4.6 μM, respectively. With this method, it was possible to accurately analyse the amino acid composition of bovine serum albumin, soy meal, Jatropha press cake, and cyanophycin. Mean reproducibility of all amino acids from bovine serum albumin was 6.8 %, with a mean recovery of 95 %. The sample run time is 16 min with a total cycle time from injection to injection of an acid hydrolyzed sample of 22 min, resulting in a greener method due to a reduction in solvent consumption.     

Role of oxygen during CdTe growth for CdTe photovoltaic devices

Polycrystalline CdTe thin films for CdTe solar cell devices are typically grown using physical vapor techniques such as close‐spaced sublimation or vapor transport deposition with, in some cases, a small amount of oxygen in the process gas. In this report, we discuss the results of growing CdTe films in an environment of pure oxygen using close‐space sublimation. The results show that oxygen has a positive impact on CdTe film quality as it increases charge carrier mobility and lifetime in the absorber layer of CdTe‐based devices. This has resulted in a 10–20 mV improvement in open‐circuit voltages when growing the CdTe in pure oxygen. Copyright © 2014 John Wiley & Sons, Ltd.