Teaching Construction in the Virtual University: the WINDS project

This paper introduces some of the Information Technology solutions adopted in Web based INtelligent Design Support (WINDS) to support education in A/E/C design. The WINDS project WINDS is an EC-funded project in the 5th Framework, Information Society Technologies programme, Flexible University key action. WINDS is divided into two actions: ·The research technology action is going to implement a learning environment integrating an intelligent tutoring system, a computer instruction management system and a set of co-operative supporting tools. ·The development action is going to build a large knowledge base supporting Architecture and Civil Engineering Design Courses and to experiment a comprehensive Virtual School of Architecture and Engineering Design. During the third year of the project, more than 400 students all over Europe will attend the Virtual School. During the next three years the WINDS project will span a total effort of about 150 man-years from 28 partners of 10 European countries. The missions of the WINDS project are: Advanced Methodologies in Design Education. WINDS drives a breakdown with conventional models in design education, i.e. classroom or distance education. WINDS implements a problem oriented knowledge transfer methodology following Roger Schank's Goal Based Scenario (GBS) pedagogical methodology. GBS encourages the learning of both skills and cases, and fosters creative problem solving. Multidisciplinary Design Education. Design requires creative synthesis and open-end problem definition at the intersection of several disciplines. WINDS experiments a valuable integration of multidisciplinary design knowledge and expertise to produce a high level standard of education. Innovative Representation, Delivery and Access to Construction Education. WINDS delivers individual education customisation by allowing the learner access through the Internet to a wide range of on-line courses and structured learning objects by means of personally tailored learning strategies. WINDS promotes the 3W paradigm: learn What you need, Where you want, When you require. Construction Practice. Construction industry is a repository of ""best practices"" and knowledge that the WINDS will profit. WINDS system benefits the ISO10303 and IFC standards to acquire knowledge of the construction process directly in digital format. On the other hand, WINDS reengineers the knowledge in up-to-date courses, educational services, which the industries can use to provide just-in-time rather than in-advance learning. WINDS IT Solutions The missions of the WINDS project state many challenging requirements both in knowledge and system architecture. Many of the solutions adopted in these fields are innovative; others are evolution of existing technologies. This paper focuses on the integration of this set of state-of-the-art technologies in an advanced and functionally sound Computer Aided Instruction system for A/E/C Design. In particular the paper deals with the following aspects: Standard Learning Technology Architecture The WINDS system relies on the in progress IEEE 1484.1 Learning Technology Standard Architecture. According to this standard the system consists of two data stores, the Knowledge Library and the Record Database, and four process: System Coach, Delivery, Evaluation and the Learner. WINDS implements the Knowledge Library into a three-tier architecture: 1.Learning Objects: ·Learning Units are collections of text and multimedia data. ·Models are represented in either IFC or STEP formats. ·Cases are sets of Learning Units and Models. Cases are noteworthy stories, which describes solutions, integrate technical detail, contain relevant design failures etc. 2.Indexes refer to the process in which the identification of relevant topics in design cases and learning units takes place. Indexing process creates structures of Learning Objects for course management, profile planning procedures and reasoning processes. 3.Courses are taxonomies of either Learning Units or a design task and Course Units. Knowledge Representation WINDS demonstrates that it is possible and valuable to integrate a widespread design expertise so that it can be effectively used to produce a high level standard of education. To this aim WINDS gathers area knowledge, design skills and expertise under the umbrellas of common knowledge representation structures and unambiguous semantics. Cases are one of the most valuable means for the representation of design expertise. A Case is a set of Learning Units and Product Models. Cases are noteworthy stories, which describe solutions, integrate technical details, contain relevant design failures, etc. Knowledge Integration Indexes are a medium among different kind of knowledge: they implement networks for navigation and access to disparate documents: HTML, video, images, CAD and product models (STEP or IFC). Concept indexes link learning topics to learning objects and group them into competencies. Index relationships are the base of the WINDS reasoning processes, and provide the foundation for system coaching functions, which proactively suggest strategies, solutions, examples and avoids students' design deadlock. Knowledge Distribution To support the data stores and the process among the partners in 10 countries efficiently, WINDS implements an object oriented client/server as COM objects. Behind the DCOM components there is the Dynamic Kernel, which dynamically embodies and maintains data stores and process. Components of the Knowledge Library can reside on several servers across the Internet. This provides for distributed transactions, e.g. a change in one Learning Object affects the Knowledge Library spread across several servers in different countries. Learning objects implemented as COM objects can wrap ownership data. Clear and univocal definition of ownerships rights enables Universities, in collaboration with telecommunication and publisher companies, to act as "education brokers". Brokerage in education and training is an innovative paradigm to provide just-in-time and personally customised value added learning knowledg

A mathematical model for controlled drug delivery in swelling polymers

We propose a one-dimensional model to describe the sorption of a solvent by a polymeric membrane, followed by polymer swelling and drug release. We assume that the solvent diffuses into the membrane and induces a stress driven diffusion, that causes a non-Fickian mass flux. We assume that the drug is present in two states (dissolved and undissolved) and that its transport occurs by Fickian diffusion and non-linear dissolution. Polymer swelling is tracked with a volume conservation equation. The system of partial differential equations that define the model is numerically solved. A qualitative analysis of the dependence of the solutions on the parameters of the model shows a complete agreement with the expected physical behavior

A new look to non-Fickian diffusion

In this paper a non linear mathematical model to describe absorption phenomena in polymers is proposed. The model is established assuming that the diffusing penetrant causes a deformation which induces a viscoelastic stress responsible for a convective field. This convective field is defined to represent an opposition of the polymer to the Fickian diffusion. Several numerical examples show the effectiveness of the model

Design and first development of an automated real‐time safety management system for construction sites

This paper reports a feasibility study which addressed the development of a new, advanced system mainly devoted to automatic real‐time health and safety management on construction sites. The preliminary analyses and experiments described in this paper concern two of the most important functionalities which must be included in the system's final release. The first functionality consists in real‐time position‐tracking of workers involved on construction sites and the second ‐ in a software tool for the prevention of non‐authorized access to dangerous zones. This research step is part of a vaster, ongoing research project, addressing the development of a new generation of advanced construction management systems which allow real‐time monitoring and coordination of tasks, automatic health and safety management, on‐site delivery of technical information and the capture of "as‐built" documentation. This paper focuses mainly on the development of a reliable methodology for real‐time monitoring of the position of both workers and equipment in outdoor construction sites by applying Ultra Wide Band (UWB) based technologies. This positioning system was then interfaced with a software tool which performs virtual fencing of pre‐selected, dangerous areas. Guidelines for the design of the receivers' topology will be addressed and the results of measurements recorded on a typical medium‐sized block of flats, during different phases of the construction progress will be summed up. Finally, the preliminary experimental results obtained by the virtual fencing application tool will be presented and used to plan future research objectives. Santrauka Straipsnyje aptartos naujos automatinės darbo ir saugos valdymo sistemos statybos aikštelėje kūrimo galimybės. Aprašytos preliminarios analizės ir eksperimentai – du pagrindiniai veiksniai, kurie turi būti įtraukti į galutinį sistemos variantą. Pirmasis veiksnys susijęs su statybos aikštelės darbininkų padėties realiu laiku nustatymu. Kompiuterine programa ribojamas jų patekimas į pavojingas neleistinas zonas. Šie tyrimai yra didelio besitęsiančio projekto dalis. Projektas susijęs su naujos kartos statybos valdymo sistemos kūrimu. Sistema leis kontroliuoti statybos eigą realiu laiku, užtikrinti automatinį darbų saugos valdymą, techninės informacijos ir dokumentacijos gavimą. Straipsnyje pagrindinis dėmesys sukoncentruotas į patikimos metodikos kūrimą. Taikant šią metodiką ir ultraplačiajuosčio bevielio ryšio (angl. Ultra Wide Band (UWB)) technologiją, galima bus nustatyti darbininkų ir įrangos padėtį atvirose statybos aikštelėse realiu laiku. Ši nustatymo sistema per grafinę terpę yra sujungta su programine įranga, kuri sukuria virtualų aptvarą iš anksto nurodytoms pavojingoms zonoms. Pateiktos imtuvo topologijos projektavimo rekomendacijos. Įvertinti tipinių vidutinio dydžio butų blokų užfiksuotų matavimų rezultatai skirtingais statybos etapais. Pateikti preliminarūs eksperimentiniai rezultatai, gauti įvedus virtualaus aptvėrimo koncepciją. Šie rezultatai bus panaudoti planuojant būsimų tyrimų tikslus

Three-dimensional (3D) Printed Model to Plan the Endoscopic Treatment of Upper Airway Stenosis

Background: Endoscopic management of tracheal stenosis may be challenging, especially in the case of complex stenosis placed near the vocal folds, and needing stent placement. Herein, we evaluated the utility of the three-dimensional (3D) airway model for procedural planning in a consecutive series of patients with complex airway stenosis and scheduled for endoscopic treatment. Methods: This strategy was applied to 7 consecutive patients with tracheal stenosis unfit for surgery. The model was printed in a rubber-like material, and almost 7 hours were needed to create it. All patients presented respiratory failure with a mean value of 3.4±0.4 Medical Research Council (MRC) dyspnea scale, 47±3.9 forced expiratory volume in 1 second (FEV1%), and an impairment in the 6-minute walking test (6MWT) (mean value, 175±53 m). The mean length of the stenosis was 19±3.4 mm; 3 of the 7 (43%) patients presented a subglottic stenosis. In 4/7 (57%) patients the stenosis was >5 mm, but its treatment required the placement of a stent because of the presence of tracheal cartilage injury. Results: The mean operation time was 22.7±6.6 minutes. No complications were observed during and after the procedure. A significant increase of MRC (3.4±0.4 vs. 1.6±0.5; P=0.003), of FEV1% (47±3.9 vs. 77±9.7; P=0.001), and of 6MWT (175±53 vs. 423±101; P=0.0002) was observed after the procedure (mean follow-up, 11.1±8.8 mo). Conclusion: Our 3D airway model in the management of airway stenosis is useful for procedural planning, rehearsal, and education. The fidelity level of the 3D model remains the main concern for its wider use in patient care. Thus, our impressions should be confirmed by future prospective studies

Histology and ultrastructure of a tissue-engineered collagen meniscus before and after implantation

The collagen meniscus implant (CMI) is a tissue-engineering technique designed to stimulate regeneration of meniscus-like tissue in cases of irreparable tears or previous meniscectomy. CMI morphology was investigated before and after implantation by light microscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). In a case series biopsy specimens were harvested from four patients who underwent a second arthroscopic look 6 months after placement of the CMI. CMI sections appeared composed of parallel connective laminae of 10-30 mu m, connected by smaller bundles (5-10 mu m). This connective network formed lacunae with diameters between 40 and 60 mu m. At greater magnification, the walls of the lacunae demonstrated tightly packed and randomly distributed collagen fibrils, with diameters ranging from 73 to 439 nm. In the biopsy specimens, the lacunae were filled with connective tissue that contained newly formed vessels and fibroblast-like cells, presenting an abundant rough endoplasmic reticulum and several mitochondria. In the extracellular matrix, the collagen fibrils showed uniform diameters (126 nm +/- 32 nm). The original structure of CMI was still recognizable, and no inflammatory cells were detected within the implant. The morphological findings of this case series demonstrate that CMI provides a three-dimensional scaffold suitable for colonization by precursor cells and vessels and leading to the formation of a fully functional tissue

Chirality Effects on Peptide Self-Assembly Unraveled from Molecules to Materials

Self-assembling short peptides are attractive minimal systems for mimicking the constituents of living systems and building (bio)materials. The combination of both D- and L-amino acids into heterochiral sequences is a versatile strategy for building durable supramolecular architectures, especially when their homochiral analogs do not self-assemble. The reasons for this divergent behavior have remained obscure until now. Here, we elucidate how and why homochiral and heterochiral peptides behave differently. We identify a key spectroscopy signature and its corresponding molecular conformation, whereby an amphiphilic structure is uniquely enabled by the peptide stereochemistry. Importantly, we unravel the self-assembly process as a continuum from the conformation of single molecules to their organization into nano- and microstructures and through to macroscopic hydrogels, which are probed for cytotoxicity in fibroblast cell culture. In this way, (bio)material properties at the macro-scale can be linked to the chemical structure of their building blocks at the angstrom scale. Nature makes pervasive use of homochirality (e.g., D-sugars and L-peptides) to assemble biomolecules, whose interactions determine life processes. D-amino acids rarely occur, and their effects are not yet completely understood. For a long time, structural complexity (e.g., polypeptides and constrained molecules) was considered a requirement for achieving defined conformations that ultimately allow biomolecule recognition and function. Here, we detail how minimalist building blocks can adopt conformations with a characteristic spectroscopic signature, whereby substitution of just one L-amino acid for its D mirror image leads to a divergent path for assembly in water. Subtle molecular variations are amplified through increasing size scale all the way to macroscopic differences that are visible to the eye. Ultimately, the design of heterochiral (bio)molecules thus provides an alternative approach to shed new light on the supramolecular interactions that define life as we know it. This work explains why and how heterochiral and homochiral tripeptides differ in their assembly in water. A characteristic spectroscopic signature is assigned to molecular conformation. We monitor the process as a continuum from the molecular scale to the macroscopic biomaterials so that the final properties are linked to chemical structure of the building blocks. This work lays the foundation for the design of supramolecular hydrogel biomaterials based on short sequences of hydrophobic D- and L-amino acids

Divergência genética entre linhagens de milho utilizando microssatélites e correlação com desempenho de híbridos simples

O sucesso nos programas de melhoramento genético de milho depende da identificação de genitores com boa capacidade de combinação para a produção de híbridos e na conservação da variabilidade genética do germoplasma. O emprego de marcadores moleculares pode auxiliar na avaliação da diversidade genética e na predição de híbridos, por meio da estimativa da distância genética. Com esse objetivo foram genotipadas, por marcadores microssatélites, 40 linhagens oriundas dos compostos Dentado e Flintisa e investigada a correlação do desempenho dos híbridos simples interpopulacionais com as distâncias genéticas entre suas linhagens. Verificou-se diversidade genética nos dois grupos de linhagens, permitindo a separação em grupos heteróticos distintos, mas sem concordância total com os dados de genealogia. As correlações entre performance dos híbridos e distância genética das linhagens foram baixas, indicando que altos níveis de distância genética entre linhagens é condição necessária, mas não suficiente para que seus híbridos exibam as melhores performances

Education modulates brain maintenance in presymptomatic frontotemporal dementia

Objective Cognitively engaging lifestyles have been associated with reduced risk of conversion to dementia. Multiple mechanisms have been advocated, including increased brain volumes (ie, brain reserve) and reduced disease progression (ie, brain maintenance). In cross-sectional studies of presymptomatic frontotemporal dementia (FTD), higher education has been related to increased grey matter volume. Here, we examine the effect of education on grey matter loss over time. Methods Two-hundred twenty-nine subjects at-risk of carrying a pathogenic mutation leading to FTD underwent longitudinal cognitive assessment and T1-weighted MRI at baseline and at 1 year follow-up. The first principal component score of the graph-Laplacian Principal Component Analysis on 112 grey matter region-of-interest volumes was used to summarise the grey matter volume (GMV). The effects of education on cognitive performances and GMV at baseline and on the change between 1 year follow-up and baseline (slope) were tested by Structural Equation Modelling. Results Highly educated at-risk subjects had better cognition and higher grey matter volume at baseline;moreover, higher educational attainment was associated with slower loss of grey matter over time in mutation carriers. Conclusions This longitudinal study demonstrates that even in presence of ongoing pathological processes, education may facilitate both brain reserve and brain maintenance in the presymptomatic phase of genetic FTD