Intelligent computational sketching support for conceptual design

Sketches, with their flexibility and suggestiveness, are in many ways ideal for expressing emerging design concepts. This can be seen from the fact that the process of representing early designs by free-hand drawings was used as far back as in the early 15th century [1]. On the other hand, CAD systems have become widely accepted as an essential design tool in recent years, not least because they provide a base on which design analysis can be carried out. Efficient transfer of sketches into a CAD representation, therefore, is a powerful addition to the designers' armoury.It has been pointed out by many that a pen-on-paper system is the best tool for sketching. One of the crucial requirements of a computer aided sketching system is its ability to recognise and interpret the elements of sketches. 'Sketch recognition', as it has come to be known, has been widely studied by people working in such fields: as artificial intelligence to human-computer interaction and robotic vision. Despite the continuing efforts to solve the problem of appropriate conceptual design modelling, it is difficult to achieve completely accurate recognition of sketches because usually sketches implicate vague information, and the idiosyncratic expression and understanding differ from each designer

Shape matching and clustering

Generalising knowledge and matching patterns is a basic human trait in re-using past experiences. We often cluster (group) knowledge of similar attributes as a process of learning and or aid to manage the complexity and re-use of experiential knowledge [1, 2]. In conceptual design, an ill-defined shape may be recognised as more than one type. Resulting in shapes possibly being classified differently when different criteria are applied. This paper outlines the work being carried out to develop a new technique for shape clustering. It highlights the current methods for analysing shapes found in computer aided sketching systems, before a method is proposed that addresses shape clustering and pattern matching. Clustering for vague geometric models and multiple viewpoint support are explored

Shape matching and clustering in design

Generalising knowledge and matching patterns is a basic human trait in re-using past experiences. We often cluster (group) knowledge of similar attributes as a process of learning and or aid to manage the complexity and re-use of experiential knowledge [1, 2]. In conceptual design, an ill-defined shape may be recognised as more than one type. Resulting in shapes possibly being classified differently when different criteria are applied. This paper outlines the work being carried out to develop a new technique for shape clustering. It highlights the current methods for analysing shapes found in computer aided sketching systems, before a method is proposed that addresses shape clustering and pattern matching. Clustering for vague geometric models and multiple viewpoint support are explored

Soft Capping of Archaeological Masonry Walls: Far View House, Mesa Verde National Park

The control of moisture and temperature fluctuations within masonry walls is critical for conservation of architectural heritage and especially for fragmentary walls within archaeological sites. Exposed compound walls traditionally have been protected by hard cappings of lime, cement, and modified soil mortars. However, hard capping has been found to be inadequate in addressing the long-term management of moisture ingress and thermal movement that will continue to stress and damage the wall. Instead of protecting the wall as initially designed, hard capping can actually accelerate deterioration over time. In order to counter such problems posed by hard capping, a procedure called \u27soft capping\u27 has been introduced in recent years at several archaeological sites in England, Turkey and elsewhere. Soft capping replaces hard caps with vegetation planted on top of layers of soil, gravel, and geosynthetics. The idea is to prevent water penetration and to reduce thermal fluctuations by taking advantage of plants\u27 abilities to utilize the water and provide a protective barrier on the wall top. The concept is very similar to green roof technology that has gained increased popularity in recent years. This paper will present laboratory and field-based research conducted on the performance characteristics of soft capping for the exposed masonry walls at Mesa Verde National Park, Colorado. Wall movement, moisture and temperature as well as environmental conditions were monitored to evaluate the effects of hard and soft capping on the test walls

Spatial cognitive implications of user interfaces in virtual reality and route guidance

The relationship between spatial learning and technology is becoming more intimately intertwined. This dissertation explores that relationship with multiple technologies and multiple types of spatial knowledge. With virtual reality, teleporting is commonly used to explore large-scale virtual environments when users are limited by the tracked physical space. Past work has shown that locomotion interfaces such as teleporting have spatial cognitive costs associated with the lack of accompanying self-motion cues for small-to-medium scale movement in virtual environments, but less is known about whether the spatial cognitive costs extend to learning a large-scale virtual environment. Experiment 1 (Chapter 2) evaluates whether rotational self-motion cues teleporting interfaces impact spatial learning for large-scale virtual environments. using two measures of survey learning (an object-to-object pointing task and map drawing task). Results indicate that access to rotational self-motion cues when teleporting led to more accurate survey representations of large-scale virtual environments. Therefore, virtual reality developers should strongly consider the benefits of rotational self-motion cues when creating locomotion interfaces. For Experiments 2 and 3 (Chapter 3), previous work has demonstrated that repeatedly using GPS route guidance reliably diminishes route learning. Memory research has shown that recalling information (i.e., testing) significantly improves retention of that information when compared to restudying the same information. Similarly, memory retrieval of routes during learning may be advantageous for long-term retention compared to following route guidance using a GPS. However, whether such a benefit would occur for route learning is not clear because the benefits of testing have primarily been explored with verbal materials. Experiments 2 and 3 explore whether retrieving routes from memory during learning enhance route knowledge of a large-scale virtual city using a driving simulator compared to learning a route by repeatedly following GPS route guidance. Results from both experiments demonstrated that there was no difference in performance between testing and repeatedly following route guidance at final test, but further analysis revealed that in the testing condition, a large proportion of errors produced during learning was also repeated at final test. The experiments described here not only expand the current knowledge regarding the intersection of technology and spatial learning, but also underscore the importance of evaluating applications of spatial cognitive theory across a range of applied domains

Common CHD8 Genomic Targets Contrast With Model-Specific Transcriptional Impacts of CHD8 Haploinsufficiency.

The packaging of DNA into chromatin determines the transcriptional potential of cells and is central to eukaryotic gene regulation. Case sequencing studies have revealed mutations to proteins that regulate chromatin state, known as chromatin remodeling factors, with causal roles in neurodevelopmental disorders. Chromodomain helicase DNA binding protein 8 (CHD8) encodes a chromatin remodeling factor with among the highest de novo loss-of-function mutation rates in patients with autism spectrum disorder (ASD). However, mechanisms associated with CHD8 pathology have yet to be elucidated. We analyzed published transcriptomic data across CHD8 in vitro and in vivo knockdown and knockout models and CHD8 binding across published ChIP-seq datasets to identify convergent mechanisms of gene regulation by CHD8. Differentially expressed genes (DEGs) across models varied, but overlap was observed between downregulated genes involved in neuronal development and function, cell cycle, chromatin dynamics, and RNA processing, and between upregulated genes involved in metabolism and immune response. Considering the variability in transcriptional changes and the cells and tissues represented across ChIP-seq analysis, we found a surprisingly consistent set of high-affinity CHD8 genomic interactions. CHD8 was enriched near promoters of genes involved in basic cell functions and gene regulation. Overlap between high-affinity CHD8 targets and DEGs shows that reduced dosage of CHD8 directly relates to decreased expression of cell cycle, chromatin organization, and RNA processing genes, but only in a subset of studies. This meta-analysis verifies CHD8 as a master regulator of gene expression and reveals a consistent set of high-affinity CHD8 targets across human, mouse, and rat in vivo and in vitro studies. These conserved regulatory targets include many genes that are also implicated in ASD. Our findings suggest a model where perturbation to dosage-sensitive CHD8 genomic interactions with a highly-conserved set of regulatory targets leads to model-specific downstream transcriptional impacts

Thermal Analysis of Two and Three-Gate Sand Casting Mould

A study of thermal characteristics of the molten metal in sand casting process had been carried out. This comprises of experimental work and modeling of casting process. Two sand molds are fabricated using the carbon dioxide-silicate method. One of them has 2 gates and the other one has 3 gates. Data of temperature distribution can be obtained by detecting the temperature changes at thermocouples from various predetermined location of the sand mold. Presence of molten metal can be known by observing the drastic changes of temperature at a particular point and therefore the flow characteristics was studied. The data is presented in a graphical format and is compared with the calculated result produced from modeling program called Thermnet. The Thermnet program is a simulation program for thermal analysis. This simulation program is Network technique based. Comparison of modeling and experimental results are also presented. Finally, base on these data, weak point of the sand mold design is being pointed out and proposal for a better design is made

Carbon Doped Silicon Dioxide Low K Dielectric Material.[QC585.75.S55 L732 2004 f rb][Microfiche 7649]

Objektif kajian ini adalah untuk mengkaji keberkesanan mendopkan sebatian karbon keatas SiO2 untuk menghasilkan bahan dielektrik k rendah. The semiconductor industry is entering a new millennium where scientists and engineers are continuing to search for the ideal dielectric material for future chip fabrication

INVESTIGATING THE RELATIONSHIP BETWEEN JOINT COUPLING COORDINATION AND MUSCLE ACTIVITY DURING WALKING

The study aimed to investigate the relationship between joint coupling coordination and muscle activity of the lower limb during normal gait in shod and barefoot walking. Ten healthy participants served in this study. We assessed joint coordination and muscle activity while the participants walked on a treadmill at their self-selected speed in shod and barefoot conditions. T-tests were used to determine the differences between walking conditions in the early, mid and late phases of support. A cross-correlation analysis was used to determine the similarity between the coordination angle and EMG profiles in the three phases of support. The study suggested no differences between shod and barefoot coordination. The correlation coefficients were moderately high (r=0.6) for both shod and barefoot. It was concluded that the rearfoot/tibia coordination may be under passive rather than active control