The Environmental Contribution to Wayfinding in Museums: Enhancement and Usage by Controlling Flows and Paths

The field of research in which wayfinding is situated refers to the way people move in reaction to environmental stimulation. It therefore fully concerns not just signage but also space designing, its geometric configuration, technical solutions and their material characterization. The focus is consequently on environmental factors that facilitate wayfinding in a museum (accessibility, visibility, etc.) and on other elements such as spatial configuration, architectural features and functional aspects. These factors influence relational phenomena and therefore visitors’ satisfaction. Methods and tools for designing and managing spaces have been studied in the research. The configurational analysis method of space has been used to objectify syntactic features of space. In particular, the outcomes of an experimental project, which have been analyzed in a master’s thesis on the re-functionalization of the museum of Palazzo dei Diamanti in Ferrara, are presented. Permeability, proximity, connections of spaces, namely meaningful features to ensure wayfinding have been examined. Space parameters resulting from the geometry of the layout, from the visual connections and from the changes of direction were then evaluated. The outcomes have been used as inputs for designing a unitary tour route circuit, that also reconnects the museum’s second floor, and for planning three independent alternative routes for a differentiated use of the museum

CVT-based 2D motion planning with maximal clearance

Maximal clearance is an important property that is highly desirable in multi-agent motion planning. However, it is also inherently difficult to attain. We propose a novel approach to achieve maximal clearance by exploiting the ability of evenly distributing a set of points by a centroidal Voronoi tessellation (CVT). We adapt the CVT framework to multi-agent motion planning by adding an extra time dimension and optimize the trajectories of the agents in the augmented domain. As an optimization framework, our method can work naturally on complex regions. We demonstrate the effectiveness of our algorithm in achieving maximal clearance in motion planning with some examples.published_or_final_versionThe 2011 IEEE International Conference on Robotics and Automation (ICRA), Shanghai, China, 9-13 May 2011. In Proceedings of the IEEE-ICRA, 2011, p. 2281-228

Rod-like trabeculae extraction from cancellous bone microstructure using topological analysis

The study of the microstructure in cancellous bone is important in osteoporosis research. In this paper, we focus in the extraction of rod-like trabeculae in cancellous hone, whose topological and geometrical properties are known to be strongly related to bone strength. Three dimensional (3D) cancellous bone volume data obtained from micro Computed Tomography (micro-CT) scans is used in our analysis. Because of the complexity of the cancellous bone microstructure, the mere use of existing 3D digital topology method's is unable to yield satisfactory results for trabeculae extraction. We devise several enhancements which are specific to the identification of rod-like trabeculae. Experimental results show that the accuracy of trabeculae extraction is greatly improved. This application study may help clinicians to solve problems in future. © 2005 IEEE.published_or_final_versio

Visibility-based coverage of mobile sensors in non-convex domains

The area coverage problem of mobile sensor networks has attracted much attention recently, as mobile sensors find many important applications in remote and hostile environments. However, the deployment of mobile sensors in a non-convex domain is nontrivial due to the more general shape of the domain and the attenuation of sensing capabilities caused by the boundary walls or obstacles. We consider the problem of exploration and coverage by mobile sensors in an unknown non-convex domain. We propose the definition of 'visibility-based Voronoi diagram' and extend the continuous-time Lloyd's method, which only works for convex domains, to deploy the mobile sensors in the unknown environments in a distributed manner. Our simulations show the effectiveness of the proposed algorithms. © 2011 IEEE.published_or_final_versionThe 8th International Symposium on Voronoi Diagrams in Science and Engineering (ISVD2011), Qingdao, China, 28-30 June 2011. In Proceedings of the 8th ISVD, 2011, p. 105-11

Continuous collision detection for ellipsoids

We present an accurate and efficient algorithm for continuous collision detection between two moving ellipsoids. We start with a highly optimized implementation of interference testing between two stationary ellipsoids based on an algebraic condition described in terms of the signs of roots of the characteristic equation of two ellipsoids. Then we derive a time-dependent characteristic equation for two moving ellipsoids, which enables us to develop a real-time algorithm for computing the time intervals in which two moving ellipsoids collide. The effectiveness of our approach is demonstrated with several practical examples. © 2006 IEEE.published_or_final_versio

Planar hexagonal meshing for architecture

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VIABILITY, FATTY ACID COMPOSITION, AND STRUCTURE OF THE CORALLINE ALGA CORALLINA PILULIFERA

The decrease in the seaweed flora in some rocky areas, known as algal whitening or barren ground, is associated with some species of coralline algae. To determine the biological characteristics of a representative species of branched coralline alga, the number of medullary tiers was counted and ranged from 12 to 16. The 18S rDNA, psbA, and rbcL genes were used to confirm the identification of Corallina pilulifera. Measuring viability using triphenyl tetrazolium chloride showed highly viability from December to January. Cultural conditions of 16 C, 16 h light:8 h dark cycle, and 40 mu E m(-2) s(-1) light intensity were optimal for maintaining the viability of the coralline alga for up to three days. The fatty acids included 31.4% omega-3 eicosapentaenoic acid. Scanning electron microscopy of the surface structure revealed unique round wells about 7.9 +/- 1.3 mu m in diameter. The coralline alga, preventing fleshy seaweeds, may be used as a potential template for the creation of new environmentally friendly biomimetic antifouling material against the attachment of soft foulants, especially micro- and macroalgae.X111Ysciescopu

Extracellular Vesicles Derived from Gram-Negative Bacteria, such as Escherichia coli, Induce Emphysema Mainly via IL-17A-Mediated Neutrophilic Inflammation

Recent evidence indicates that Gram-negative bacteria-derived extracellular vesicles (EVs) in indoor dust can evoke neutrophilic pulmonary inflammation, which is a key pathology of chronic obstructive pulmonary disease (COPD). Escherichia coli is a ubiquitous bacterium present in indoor dust and secretes nanometer-sized vesicles into the extracellular milieu. In the current study, we evaluated the role of E. coli-derived EVs on the development of COPD, such as emphysema. E. coli EVs were prepared by sequential ultrafiltration and ultracentrifugation. COPD phenotypes and immune responses were evaluated in C57BL/6 wild-type (WT), IFN-gamma-deficient, or IL-17A-deficient mice after airway exposure to E. coli EVs. The present study showed that indoor dust from a bed mattress harbors E. coli EVs. Airway exposure to E. coli EVs increased the production of proinflammatory cytokines, such as TNF-alpha and IL-6. In addition, the repeated inhalation of E. coli EVs for 4 wk induced neutrophilic inflammation and emphysema, which are associated with enhanced elastase activity. Emphysema and elastase activity enhanced by E. coli EVs were reversed by the absence of IFN-gamma or IL-17A genes. In addition, during the early period, lung inflammation is dependent on IL-17A and TNF-alpha, but not on IFN-gamma, and also on TLR4. Moreover, the production of IFN-gamma is eliminated by the absence of IL-17A, whereas IL-17A production is not abolished by IFN-gamma absence. Taken together, the present data suggest that E. coli-derived EVs induce IL-17A-dependent neutrophilic inflammation and thereby emphysema, possibly via upregulation of elastase activity.X111613Ysciescopu

VISJET & VISFLOOD: Software for environment hydraulic modeling & visualization

We present two general interactive PC-based modeling and visualization software systems developed for the study of two types of environmental water flows: buoyant jet mixing and urban drainage problems. VISJET (http://www.aoe-water.hku.hk/visjet) is arguably the most robust software with advanced graphics for the prediction of mixing and transport of effluent discharges into a stratified crossflow. The prediction engine is a Lagrangian model for buoyant jets with three-dimensional trajectories, and is based on extensive basic experiments and turbulence model calculations. It can be used in outfall design and environmental impact assessment, and as an educational or training tool. VISFLOOD (http://www.aoe-water.hku.hk/visflood) is based on the numerical solution of the Saint-Venant equations, and caters for the simulation of unsteady flood propagation in urban drainage systems. Both software systems are fully interactive with data interrogation; the 3D visualization is fully integrated with the model engine, and enables the user to appreciate the context of the problem in a most effective way. Both models have been well-validated against laboratory and field data, and have been applied to many actual engineering projects. This software product is an outcome of a grant by the Hong Kong Innovation and Technology Fund (ITF).published_or_final_versio

Implementation of secondary stroke prevention protocol for ischaemic stroke patients in primary care

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