兔子横纹肌的连续模型的参数估计

论述了兔子横纹肌动力特性的连续模型的建模问题.其方法在于用辅助变量法估计连续模型的参数.它的优点是即使在有色噪声条件下也能保证连续模型参数估计的无偏性.其次,用随机过程仿真验证了这个方法的有效性.最后,把这个方法用于兔子横纹肌的动力特性的辨识.     

Influence of powder characteristics on the behaviour of PIM feedstock

This work aims to analyse the impact of powders which are not conventionally intended for powder injection moulding (PIM) and how their characteristics influence the behaviour of the feedstock during mixing. Tests were performed with different alumina powders using the same binder system. The results show that mixing has a strong impact on the packing density of powders inside the feedstock, while the deagglomeration of powders makes it possible to achieve high critical powder volume concentrations (CPVCs) equal to or greater than 58 vol%. The CPVC depends on the deagglomeration efficiency. The agglomeration state – especially cohesion of the agglomerates – has an influence on the CPVC. The comparative study of mixing torques shows that the grain size and surface area of powders have a major impact on the mixing behaviour of the feedstock. During the implementation of powders, variabilities in the homogenisation of the powder/binder system and in deagglomeration are achieved as a result of powder agglomeration. It was demonstrated that the powders in this study perfectly satisfy the criteria imposed by the mixing process although they are not intended for PIM.     

Electroinduction of Peculiar Space-Charge Regions in Fully-Glassy Lead Oxyfluoroborate Materials Discerned from Impedance Spectroscopy

Lead oxyfluoroborate (BO_1.5–PbO–PbF₂) glasses were prepared and studied in this work in terms of dielectric response. By applying impedance spectroscopy, this study shows that electric field-induced peculiar space-charge regions form in these glasses, in the bulk adjacent to the glass–electrode interfaces. In addition, submission of these glasses to the action of a long-term electric field results in development of surface crystallization, even below the glass transition temperature. Evidence has been given in the literature that such a phenomenon involves electric field-induced redox-type electrochemical reactions that develop, simultaneously, at both glass–electrode interfaces, promoting β-PbF₂ crystallites nucleation toward the cathode side. Accordingly, it is here concluded that the above mentioned space-charge regions should incorporate those electroactive species that look forward to participate in the redox reactions that subsequently promote incidence of this non-spontaneous crystallization phenomenon.     

Qualitative behavioral reasoning from components’ interfaces to components’ functions for DMU adaption to FE analyses

A digital mock-up (DMU), with its B-Rep model of product components, is a standard industrial representation that lacks geometric information about interfaces between components. Component shapes reflect common engineering practices that influence component interfaces with interferences and not only contacts.The proposed approach builds upon relationships between function, behavior, and shape to derive functional information from the geometry of component interfaces. Among these concepts, the concept of behavior is more difficult to set up and connect to the geometry of interfaces and functions. Indeed, states and design rules are introduced to express the behavior of components through a qualitative reasoning process. This reasoning process, in turn, takes advantage of domain knowledge rules and facts, checking the validity of certain hypotheses that must hold true all along a specific state of the product’s lifecycle, such as operational, stand-by or relaxed states. Eliminating configurations that contradict one or more of those hypotheses in their corresponding reference state reduces ambiguity, subsequently producing functional information in a bottom-up manner.This bottom-up process starts with the generation of a conventional interfaces graph (CIG) with components as nodes, and conventional interfaces (CIs) as arcs. A CI is initially defined by a geometric interaction that can be a contact or an interference between two components. CIs are then populated with functional interpretations (FIs) according to their geometric properties, producing potentially many combinations. A first step of the reasoning process, the validation against reference states, reduces the number of FIs per CI.Domain knowledge rules are then applied again to group semantics of component interfaces into one functional designation per component to connect together geometric entities of its boundary with its function.     

Computing the Hausdorff distance between two B-spline curves

This paper presents a geometric pruning method for computing the Hausdorff distance between two B-spline curves. It presents a heuristic method for obtaining the one-sided Hausdorff distance in some interval as a lower bound of the Hausdorff distance, which is also possibly the exact Hausdorff distance. Then, an estimation of the upper bound of the Hausdorff distance in an sub-interval is given, which is used to eliminate the sub-intervals whose upper bounds are smaller than the present lower bound. The conditions whether the Hausdorff distance occurs at an end point of the two curves are also provided. These conditions are used to turn the Hausdorff distance computation problem between two curves into a minimum or maximum distance computation problem between a point and a curve, which can be solved well. A pruning technique based on several other elimination criteria is utilized to improve the efficiency of the new method. Numerical examples illustrate the efficiency and the robustness of the new method.     

A model-driven traceability framework for software product lines

Software product line (SPL) engineering is a recent approach to software development where a set of software products are derived for a well defined target application domain, from a common set of core assets using analogous means of production (for instance, through Model Driven Engineering). Therefore, such family of products are built from reuse, instead of developed individually from scratch. SPL promise to lower the costs of development, increase the quality of software, give clients more flexibility and reduce time to market. These benefits come with a set of new problems and turn some older problems possibly more complex. One of these problems is traceability management. In the European AMPLE project we are creating a common traceability framework across the various activities of the SPL development. We identified four orthogonal traceability dimensions in SPL development, one of which is an extension of what is often considered as “traceability of variability”. This constitutes one of the two contributions of this paper. The second contribution is the specification of a metamodel for a repository of traceability links in the context of SPL and the implementation of a respective traceability framework. This framework enables fundamental traceability management operations, such as trace import and export, modification, query and visualization. The power of our framework is highlighted with an example scenario.     

Author Index,Volume 10 (2003)

Authors Index

Author Index, Volume 10 (2003)     

Manifold-ranking based retrieval using k-regular nearest neighbor graph

Manifold-ranking is a powerful method in semi-supervised learning, and its performance heavily depends on the quality of the constructed graph. In this paper, we propose a novel graph structure named k-regular nearest neighbor (k-RNN) graph as well as its constructing algorithm, and apply the new graph structure in the framework of manifold-ranking based retrieval. We show that the manifold-ranking algorithm based on our proposed graph structure performs better than that of the existing graph structures such as k-nearest neighbor (k-NN) graph and connected graph in image retrieval, 2D data clustering as well as 3D model retrieval. In addition, the automatic sample reweighting and graph updating algorithms are presented for the relevance feedback of our algorithm. Experiments demonstrate that the proposed algorithm outperforms the state-of-the-art algorithms.     

Synthesis and characterization of polymer-coated quantum dots with integrated acceptor dyes as FRET-based nanoprobes

A fluorescence resonance energy transfer pair consisting of a colloidal quantum dot donor and multiple organic fluorophores as acceptors is reported and the photophysics of the system is characterized. Most nanoparticle-based biosensors reported so far use the detection of specific changes of the donor/acceptor distance under the influence of analyte binding. Our nanoparticle design on the other hand leads to sensors that detect spectral changes of the acceptor (under the influence of analyte binding) at fixed donor/acceptor distance by the introduction of the acceptor into the polymer coating. This approach allows for short acceptor-donor separation and thus for high-energy transfer efficiencies. Advantageously, the binding properties of the hydrophilic polymer coating further allows for addition of poly(ethylene glycol) shells for improved colloidal stability.     

Numerical study of the spectral 3-D green's function singularities for piezoelectric SAW components

This article deals with the numerical study of the singularities appearing in the spectral 3-D Green's function associated with the piezoelectric surface acoustic wave components (so-called SAW components). These electrical units are currently used today in several devices produced by the telecommunications industry (radio, TV, radar, and digital telecommunication systems). The need to improve their performance has motivated engineers and researchers to use mathematical modeling intensively, in particular the integral equations technique here used, which requires the computing of the associated Green's function and the study of its properties.