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51.
Anthropomorphizing graphical elements in multimedia learning materials improves learning outcomes. The reasons for enhanced learning are unclear. We extended a seminal anthropomorphism study in order to examine whether the effect of anthropomorphisms on learning outcomes, both immediate and delayed, is caused by the anthropomorphized elements' effects on attention distribution or by elevated positive affective–motivational states. The study had a partial 3 × 2 design (the materials' graphics: schematic vs. black‐and‐white anthropomorphisms vs. colourful anthropomorphisms × eye tracker: present vs. absent). The participants were university students (N = 181). Unexpectedly, we found no significant effect of anthropomorphisms on learning outcomes. Anthropomorphisms significantly affected attention distribution during initial fixations but not overall. Modest effect on enjoyment was found, but no such effect was detected as concerns flow and generalized positive affect. We also found that the eye tracker's mere presence had slight adverse effects on learners, but these effects did not compromise learning.  相似文献   
52.
Many software systems fail to address their intended purpose because of a lack of user involvement and requirements deficiencies. This paper discusses the elaboration of a requirements-analysis process that integrates a critical-parameter-based approach to task modeling within a user-centric design framework. On one hand, adapting task models to capture requirements bridges the gap between scenarios and critical parameters which benefits design from the standpoint of user involvement and accurate requirements. On the other hand, using task models as a reusable component leverages requirements reuse which benefits design by increasing quality while simultaneously reducing development costs and time-to-market. First, we present the establishment of both a user-centric and reuse-centric requirements process along with its implementation within an integrated design tool suite. Secondly, we report the design, procedures, and findings of two user studies aimed at assessing the feasibility for novice designers to conduct the process as well as evaluating the resulting benefits upon requirements-analysis deliverables, requirements quality, and requirements reuse.  相似文献   
53.
We introduce a compact hierarchical procedural model that combines feature‐based primitives to describe complex terrains with varying level of detail. Our model is inspired by skeletal implicit surfaces and defines the terrain elevation function by using a construction tree. Leaves represent terrain features and they are generic parametrized skeletal primitives, such as mountains, ridges, valleys, rivers, lakes or roads. Inner nodes combine the leaves and subtrees by carving, blending or warping operators. The elevation of the terrain at a given point is evaluated by traversing the tree and by combining the contributions of the primitives. The definition of the tree leaves and operators guarantees that the resulting elevation function is Lipschitz, which speeds up the sphere tracing used to render the terrain. Our model is compact and allows for the creation of large terrains with a high level o detail using a reduced set of primitives. We show the creation of different kinds of landscapes and demonstrate that our model allows to efficiently control the shape and distribution of landform features.  相似文献   
54.
Neural Computing and Applications - Social networks are known to be assortative with respect to many attributes, such as age, weight, wealth, level of education, ethnicity and gender: Similar...  相似文献   
55.
Systems-on-chip (SoCs) and SoC architectures provide a collection of challenging problems related to specification, modelling techniques, security issues and structuring questions. We describe a design methodology integrating the event B method and characterized by the incremental and proof-controlled construction of SoC models. The essence of the methodology is the refinement of models, starting from system requirements and producing event B models for characterizing the system under development. The refinement is a unifying concept that ensures the consistency of the different models produced and our contribution is an illustration through a case study, namely a system for measuring the parameters of audio/video quality in the digital video broadcasting (DVB) set of digital TV standards. The first part is the derivation of an architecture of parameters from the document ETSI TR 101 290 and the validation of the architecture using invariants of B models. The second part is the proposal of B models of the SystemC scheduler and an instantiation of these abstract models of the simulation semantics by parameters of the SystemC codes automatically translated from the B models of the DVB system. Finally, the third part relies upon a proof-based methodology for deriving an operational semantics of a given system that is expressed by an event B model including invariant properties.  相似文献   
56.
While nephrologists wait for the ideal, non invasive, inexpensive, precise, and reproducible tool to evaluate extracellular volume (ECV), they need to exert their clinical acumen in the quest of that holy grail, dry weight (DW). Estimation of DW using a clinical approach based on blood pressure (BP) and ECV is feasible and reliable as shown by successful experiences in various dialysis modes over more than three decades. But a need still exists to resolve difficulties associated with accurate assessment of BP (methods and circumstances of measurement, and the confounding effects of antihypertensive drugs) and ECV (evaluation of weight changes unrelated to ECV, lack of specificity and sensitivity of clinical symptoms, lag time, confusion in terminology). An essential point in clinical assessment of DW is that a normal BP is at the same time the target and the crucial index of DW achievement. For this reason, a trialand‐error “probe” process has to be used at intervals to make sure that the dry weight target point is correctly estimated. The various “non clinical” methods proposed for dry weight assessment increase the complexity and the cost of hemodialysis. They are, in the present state of things, more clinical research than practice tools. They do not replace clinical judgment.  相似文献   
57.
58.
The entire history of materials is examined with emphasis upon the structural differences at stages of discovery, development and mature adjustment in analogy with the S-curve of a phase change. The earliest discovery of almost all useful materials or techniques occurred in making decorative objects. Alloying, shaping and welding techniques began in jewelry and sculpture; crystallization, spinodal transformation, and interface energy equilibrium were sensitively used in ceramic glazes; oriental lacquer and celluloid trinkets are precursors of the plastic industry. Far from being an applied science, practice in materials was far in advance of physical and chemical theory until less than a century ago, and even today intuitive understanding cannot be disregarded. The alchemists built their mystic concepts upon the coloring techniques of ancient artisans. Chemistry came from dying, pot making and particularly the quantitative separatory reactions of the assayer. But, once developed, science became highly effective in controlling and improving industrial practice. The discovery of electricity gave a new type of property to be studied, and the richness of today’s approach to materials came from the subsequent joining of the physicist’s approach with the other threads that had been maturing through the ages. Technological change alters the patterns of human interaction and it underlies most social upheavals. Technology is a rich part of the human experience and it deserves far more attention than it has hitherto received by historians.  相似文献   
59.
A computer algorithm for the rapid solution of Laue back reflection patterns of sapphire crystals is described, (although other hexagonal systems could be indexed with minor changes). Reflections of planes having indices (3, 3, 3) and lower are indexed without using Wulff nets, Greninger charts, and so forth. Any film to specimen distance may be used and the systematic errors associated with this measurement are minimized to determine its best value. The computational scheme compares the angles associated with the reflections from the X-ray patterns and the true interplanar angles which are calculated from the computer program.  相似文献   
60.
The Scandinavian region is home to a unique biome with endemic plant species. The aim of this study was to explore this natural diversity and identify plant extracts providing positive skin barrier effects. Six plant extracts were identified as starting material. Following biochemical screening, two candidates outperformed the rest: Betula alba (BA) and Empetrum nigrum (EN). Quantitative PCR analysis showed that BA and EN upregulated barrier genes, when used individually and in combination. Betula alba increased AQP3 and OCLN protein expression, something niacinamide was incapable of. Additionally, the skin barrier was strengthened, evidenced by inhibition of KLK5 and hyaluronidase and showed strong antioxidant and anti-inflammatory activity through DPPH and COX2 inhibition, respectively. A first split-face clinical study was conducted using the combination of extracts versus placebo. There was a significantly better skin restructuring effect and corneocyte cohesion on the side treated with combined extracts. A second split-face clinical study assessed the combined extracts versus 3% niacinamide. Significant variations in skin hydration and TEWL were observed in favor of the extract treated side. In conclusion, we identified a natural alternative to niacinamide for improving skin barrier health, in Scandinavian plant extracts, which yield strong performance, but at a lower concentration.  相似文献   
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