A powerful finite element for plate bending

A powerful finite element formulation for plate bending has been developed using a modified version of the variational method of Trefftz. The notion of a boundary has been generalized to include the interelement boundary. All boundary conditions and the interelement continuity requirements (displacements, slopes, internal forces) have been obtained as natural conditions on the generalized boundary. Coordinate functions have been constructed to satisfy the nonhomogeneous Lagrange equation locally within the elements. Singularities due to isolated loads have been properly taken into account. For practical use a general quadrilateral element has been developed and its accuracy illustrated on several numerical examples. Work is in progress to extend the formulation to anisotropic and moderately thick plates and to vibration analysis.     

DIABCARD CCMIS--a portable and scalable CPR for diabetes care

The aim of this paper is to introduce the main software module of the DIABCARD Chip Card Medical Information System (DIABCARD CCMIS) that provides an online, portable diabetes medical record information system based on a high performance object-oriented rapid application development language such as Borland Delphi. A chip card based medical information system was developed as a good possibility to create a portable electronic patient record. In particular the patient data card makes the up-to-date patient's record available whenever needed. The developed DIABCARD Core System, described in this paper, includes a patient record management system that has the ability to handle topics such as administrative and medical data, medical anamnesis, and physical examination data. Issues tackled were simplicity, data security and reporting, customization, and internationalization. Especially for the two last issues (customization and internationalization) a novel approach based on using native initialization table files is presented. Proper care has been addressed during the development of the software modules for matters of security, data integrity and confidentiality.     

Epistemological and methodological issues for the conceptualization,development, and assessment of ICT–TPCK: Advances in technological pedagogical content knowledge (TPCK)

In this paper, several issues regarding the epistemology of technological pedagogical content knowledge (TPCK) are first raised for the purpose of clarifying the construct. Specifically, the transformative and integrative views are juxtaposed for exploring the epistemology of TPCK, and, at the end, the transformative view is adopted concluding that TPCK is a unique body of knowledge that is constructed from the interaction of its individual contributing knowledge bases. Then, ICT–TPCK is introduced as a strand of TPCK, and is described as the ways knowledge about tools and their affordances, pedagogy, content, learners, and context are synthesized into an understanding of how particular topics that are difficult to be understood by learners or difficult to be represented by teachers can be transformed and taught more effectively with technology in ways that signify its added value. One model for the development and another for the assessment of ICT–TPCK are then discussed. Technology Mapping is proposed as a situative methodology for the development of ICT–TPCK, and three forms of assessment, namely, expert assessment, peer assessment, and self-assessment are proposed for assessing teachers’ competencies to teach with technology. The paper also reports on the empirical findings of a study that was undertaken to investigate the impact of the proposed models on student learning within the context of two design tasks in a pre-service primary teacher education course. Repeated measures within-subject effects were tested and the results indicated that ICT–TPCK competency significantly improved over the course of a semester. The results of this study clearly show that the theoretical models proposed herein can positively impact the development of ICT–TPCK. Lastly, these results can be used as baseline data in future studies that may be conducted to further validate or improve the proposed models in different contexts.     

Hyperspectral imaging and spectral classification for pigment identification and mapping in paintings by El Greco and his workshop

Multimedia Tools and Applications - The identification of painting materials is of essential importance for artistic and scientific analysis of objects of artistic and historic value. In this paper...     

Bayesian learning of Bayesian networks with informative priors

This paper presents and evaluates an approach to Bayesian model averaging where the models are Bayesian nets (BNs). A comprehensive study of the literature on structural priors for BNs is conducted. A number of prior distributions are defined using stochastic logic programs and the MCMC Metropolis-Hastings algorithm is used to (approximately) sample from the posterior. We use proposals which are tightly coupled to the priors which give rise to cheaply computable acceptance probabilities. Experiments using data generated from known BNs have been conducted to evaluate the method. The experiments used 6 different BNs and varied: the structural prior, the parameter prior, the Metropolis-Hasting proposal and the data size. Each experiment was repeated three times with different random seeds to test the robustness of the MCMC-produced results. Our results show that with effective priors (i) robust results are produced and (ii) informative priors improve results significantly.     

Learning and teaching about scientific models with a computer-modeling tool

The study presents efforts to support pre-service primary school teachers in learning and teaching about scientific models, and discusses the impact of these efforts on their understandings. We provided pre-service primary school teachers with a module on computer modeling and studied the effects of this experience on their abilities to construct viable scientific models with a computer-modeling tool, namely, Model-It [Metcalf, J. S., Krajcik, J., & Soloway, E. (2000). MODEL-IT: A Design Retrospective. In M. J. Jacobson & R. B. Kozma (Eds.), Innovations in Science and Mathematics Education (pp. 77–115). Mahwah, NJ: Lawrence Erlbaum Associates], in order to teach a sixth-grade science lesson. The results of the study showed that Model-It, through its scaffolds (i.e., Plan, Build, and Test), enabled the majority of pre-service teachers to build models that were structurally correct, but simplistic. The participants showed a tendency to teach science using more often the explorative modeling method than the expressive method, and only few of them employed both methods in their lessons. In essence, Model-It effectively scaffolded pre-service teachers’ first modeling experiences and enabled them to quickly build and test their models as well as reflect on the viability of their models. However, according to the results, teachers need extensive learning experiences in order to achieve a comprehensive understanding of the process of scientific modeling in science.     

Simulation of Sheared Suspensions With a Parallel Implementation of QDPD

A parallel quaternion-based dissipative particle dynamics (QDPD) program has been developed in Fortran to study the flow properties of complex fluids subject to shear. The parallelization allows for simulations of greater size and complexity and is accomplished with a parallel link-cell spatial (domain) decomposition using MPI. The technique has novel features arising from the DPD formalism, the use of rigid body inclusions spread across processors, and a sheared boundary condition. A detailed discussion of our implementation is presented, along with results on two distributed memory architectures. A parallel speedup of 24.19 was obtained for a benchmark calculation on 27 processors of a distributed memory cluster.     

均衡点火延迟对模型燃料混合物的燃烧和烟尘排放特性的影响

本文研究了均衡点火延迟在压缩点火发动机中的作用.进行了两组实验,一组在10°曲柄角度(CAD)上止点前(BTDC)开始对燃油喷射进行恒定喷射定时测试,另一组则为持续点火定时测试,同时保持10°CAD BTDC喷射,并在燃油混合物中添加点火改良剂(2-乙基己基硝酸盐,2-EHN).使用DMS-500仪器表征烟尘颗粒的质量...