403 research outputs found
REACH implementation costs in the Belgian food industry:a semi-qualitative study
In this paper we discuss how companies in the Belgian food industry are affected by the REACH legislation and whether their competitiveness is weakened as a result. The study has been carried out through an extensive literature study, an electronic survey, in-depth interviews and a case-study. No indication is observed of REACH compliance significantly hampering the competitive position of Belgian food industry. The overall cost burden seems to be relatively low. In contrast with the chemical industry, large food companies bear the highest costs, whereas the financial impact on small and medium-sized food companies remains limited.<br
A Combined Geometric Morphometric and Discrete Element Modeling Approach for Hip Cartilage Contact Mechanics.
Finite element analysis (FEA) provides the current reference standard for numerical simulation of hip cartilage contact mechanics. Unfortunately, the development of subject-specific FEA models is a laborious process. Owed to its simplicity, Discrete Element Analysis (DEA) provides an attractive alternative to FEA. Advancements in computational morphometrics, specifically statistical shape modeling (SSM), provide the opportunity to predict cartilage anatomy without image segmentation, which could be integrated with DEA to provide an efficient platform to predict cartilage contact stresses in large populations. The objective of this study was, first, to validate linear and non-linear DEA against a previously validated FEA model and, second, to present and evaluate the applicability of a novel population-averaged cartilage geometry prediction method against previously used methods to estimate cartilage anatomy. The population-averaged method is based on average cartilage thickness maps and therefore allows for a more accurate and individualized cartilage geometry estimation when combined with SSM. The root mean squared error of the population-averaged cartilage geometry predicted by SSM as compared to the manually segmented cartilage geometry was 0.31 ± 0.08 mm. Identical boundary and loading conditions were applied to the DEA and FEA models. Predicted DEA stress distribution patterns and magnitude of peak stresses were in better agreement with FEA for the novel cartilage anatomy prediction method as compared to commonly used parametric methods based on the estimation of acetabular and femoral head radius. Still, contact stress was overestimated and contact area was underestimated for all cartilage anatomy prediction methods. Linear and non-linear DEA methods differed mainly in peak stress results with the non-linear definition being more sensitive to detection of high peak stresses. In conclusion, DEA in combination with the novel population-averaged cartilage anatomy prediction method provided accurate predictions while offering an efficient platform to conduct population-wide analyses of hip contact mechanics
Quantum benchmark for storage and transmission of coherent states
We consider the storage and transmission of a Gaussian distributed set of
coherent states of continuous variable systems. We prove a limit on the average
fidelity achievable when the states are transmitted or stored by a classical
channel, i.e., a measure and repreparation scheme which sends or stores
classical information only. The obtained bound is tight and serves as a
benchmark which has to be surpassed by quantum channels in order to outperform
any classical strategy. The success in experimental demonstrations of quantum
memories as well as quantum teleportation has to be judged on this footing.Comment: 4 pages, references added, minor change
Editorial: Statistical model-based computational biomechanics: applications in joints and internal organs
Quantum skew divergence
In this paper we study the quantum generalisation of the skew divergence,
which is a dissimilarity measure between distributions introduced by L. Lee in
the context of natural language processing. We provide an in-depth study of the
quantum skew divergence, including its relation to other state
distinguishability measures. Finally, we present a number of important
applications: new continuity inequalities for the quantum Jensen-Shannon
divergence and the Holevo information, and a new and short proof of Bravyi's
Small Incremental Mixing conjecture.Comment: Supersedes 1102:3041, as it contains many new results and
applications. v2: minor modifications, including a streamlining of the
proofs. 32 1/4 page
On Random Unitary Channels
In this article we provide necessary and sufficient conditions for a
completely positive trace-preserving (CPT) map to be decomposable into a convex
combination of unitary maps. Additionally, we set out to define a proper
distance measure between a given CPT map and the set of random unitary maps,
and methods for calculating it. In this way one could determine whether
non-classical error mechanisms such as spontaneous decay or photon loss
dominate over classical uncertainties, for example in a phase parameter. The
present paper is a step towards achieving this goal.Comment: 11 pages, typeset using RevTeX
When Do Adolescents Accept or Defy to Maternal Prohibitions? The Role of Social Domain and Communication Style.
Drawing upon both Social-Cognitive Domain Theory and Self-Determination Theory, the goal of the present multi-informant study was to test whether the correlates of maternal prohibitions depend on what is prohibited (i.e., the content of the social domain involved), thereby contrasting moral with friendship prohibitions, as well on how the prohibition is communicated, thereby contrasting an autonomy-supportive with a controlling communication style. In a sample of adolescents (N = 196; mean age = 13.9 years; 63 % female) and their mothers (N = 185; mean age = 44 years), we first examined mean-level differences between the two domains in terms of mothers' degree and style of prohibition, as well as on a number of developmental outcomes (i.e., adolescents' legitimacy perceptions, internalization, and oppositional defiance). Both adolescents and mothers reported more maternal involvement in the moral domain (e.g., higher scores for degree of prohibition and controlling communication style). In addition, adolescents reported greater perceived legitimacy and less oppositional defiance in the moral domain (as compared to the friendships domain). Second, we tested whether associations between degree and style of prohibition and the developmental outcomes were moderated by social domain. Whereas associations between degree of prohibition and developmental outcomes either were non-significant or moderated by domain, the associations with communication style were more domain-invariant, with an autonomy-supportive style generally yielding an adaptive pattern of correlates and with a controlling style relating to maladaptive outcomes. The discussion focuses on similarities and differences in the characteristics and correlates of both types of prohibitions
Maximally entangled mixed states of two qubits
We consider mixed states of two qubits and show under which global unitary
operations their entanglement is maximized. This leads to a class of states
that is a generalization of the Bell states. Three measures of entanglement are
considered: entanglement of formation, negativity and relative entropy of
entanglement. Surprisingly all states that maximize one measure also maximize
the others. We will give a complete characterization of these generalized Bell
states and prove that these states for fixed eigenvalues are all equivalent
under local unitary transformations. We will furthermore characterize all
nearly entangled states closest to the maximally mixed state and derive a new
lower bound on the volume of separable mixed states
Universal quantum Controlled-NOT gate
An investigation of an optimal universal unitary Controlled-NOT gate that
performs a specific operation on two unknown states of qubits taken from a
great circle of the Bloch sphere is presented. The deep analogy between the
optimal universal C-NOT gate and the `equatorial' quantum cloning machine (QCM)
is shown. In addition, possible applications of the universal C-NOT gate are
briefly discussed.Comment: 18 reference
BRDF characterization of Al-coated thermoplastic polymer surfaces
In this paper, we present a combined morphological and optical characterization of aluminum-coated thermoplastic polymer surfaces. Flat plastic substrates, obtained by means of an injection molding process starting from plastic granules, were coated with ultra-thin aluminum films evaporated in vacuo, on top of which a silicon-based protective layer was plasma deposited in order to prevent oxidation of the metal reflective surface. Different sample treatments were studied to unravel the influence of substrate chemistry, substrate thickness, aluminum and protective layer thickness, and surface roughness on the actual optical reflectance properties. Bidirectional reflectance distribution function measurements, corroborated by surface morphological information obtained by means of atomic force microscopy, correlate reflectance characteristics with the root-mean-square surface roughness, providing evidence for\ua0the role of the substrate and the thin films\u2019 morphology. The results unravel information of interest within many applicative fields involving metal coating processes of plastic substrates as an example in the case of automotive lighting
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