The Role of Geospatial Thinking and Geographic Skills in Effective Problem Solving with GIS: K-16 Education

Effective use of a Geographic Information System (GIS) is hampered by the limited geospatial reasoning abilities of students. The ability to reason with spatial relations, more specifically apply geospatial concepts, including the identification of spatial patterns and spatial associations, is important to geographic problem solving in a GIS context. This dissertation examines the broad influence of three factors on GIS problem solving: 1) affection towards computers, geography, and mathematics, 2) geospatial thinking, as well as 3) geographic skills. The research was conducted with 104 students in Waterloo, Ontario, Canada. Students were drawn from four educational levels: grade 9 students, 13 to 14 years of age; 1st year undergraduate university students, 3rd and 4th year undergraduate geography majors; and geography students at the graduate level ranging from 22 to 32 years of age. The level of affection is measured with modified scales borrowed from psychology. Results show that students in general exhibit positive sentiments toward computers and geography but less so towards mathematics. Spatial thinking and knowledge of geospatial concepts are measured by a 30-item scale differentiating among spatial thinkers along a novice-expert continuum. Scores on the scale showed an increase in spatial reasoning ability with age, grade, and level of education, such that grade 9 students averaged 7.5 out of 30 while the mean score of graduate students was 20.6. The final exercise assessed pertinent skills to geography namely inquiry, data collection, and analysis. In general, there was a positive correlation in the scores such that the skill proficiency increased with grade. Related analysis found three factors that affect problem-solving performance with a GIS. These include age, geographic skills (inquiry and analysis), and geospatial thinking (subscales analysis, representation, comprehension, and application). As well, the relationship(s) between performance on the geospatial scale and the observed problem-solving sequences and strategies applied on a GIS was examined. In general, students with lower scores were more apt to use basic visualization (zoom/measure tools) or buffer operations, while those with higher scores used a combination of buffers, intersection, and spatial queries. There were, however, exceptions as some advanced students used strategies that overly complicated the problem while others used visualization tools alone. The study concludes with a discussion on future research directions, followed by a series of pencil and paper games aimed to develop spatial thinking within a geographic setting

Using a computerized data collection method to explore sketch map drawing sequence

Cognitive mapping has attracted immense interest from many fields, creating collaborative and cross-disciplinary research. The study of cognitive maps enjoyed almost two decades of growth, until its decline in the early 1980s. By the 1990s, the new cross-disciplinary exchange with computer science and information technology has renewed interest in the field, which may be the next wave of cognitive mapping research explosion. This study will, through the development of an innovative tool and an in depth analysis of cognitive maps, namely, sequence, search for links between sequence and other variables, namely sketch map type classification, sketch map drawing processes and differences between female and male sketch maps. The methodological tool, namely MMAPIT, was a different approach from past studies to collect sketch maps. MMAPIT was a combination of hardware (Tablet PC) and software that allowed subjects to draw their sketch map directly on the tablet and recorded the drawing process in audio and video format. The drawing process was transcribed producing the sequence or order each element was drawn. The sequence data not only generated new ways of examining sketch maps, they also produced results worthy of note of new methodology used and the pairing of unlikely results. There were four major findings from this study, namely the fish tail graphical pattern, six ways to draw sketch maps, division of the landmark element into subgroups, and differences found between female and male produced sketch maps. The fish tail is a pattern resulting from the graphical presentation of the proportion of elements drawn at each sequence. This pattern showed the increase of landmarks and the decrease of paths throughout the graph. A second use of sequence was a method to classify sketch maps into map types including sequential, spatial and hybrid maps. Sequences were also input into a software, namely ClustalW, to cluster groups of subjects with similar sequence strings. This method not only classified map types but also revealed that sketch maps can be drawn through recalling elements in six different ways. These six drawing methods all started with paths, suggesting their importance as a framework for sketch map building. The recall order of elements is part of a larger study in psychology termed sequential spatial memory. In addition, this study also found gender differences; females drew more landmarks while males drew more paths. This study has only uncovered the beginning of the sequence puzzle. A larger sample population, cross-disciplinary work and investigation on links between sketch map sequence and memory are required to further our understanding of peoples’ perception of the environment and how that is reflected in the multilayered sketch maps. This understanding can lead to modelling peoples’ sketch maps followed by predicting travel behaviours

A Deep Learning Model for Splicing Image Detection

With the advancement of digital technology, manipulating images has become relatively easy through many photo editing techniques. One of the techniques is the splicing image method, which crops parts of images and puts them into another image creating a new composite image. The image splicing detection system is soon regarded as an exciting topic for many researchers to solve the problems of forgery images on the Internet, especially in social networks. ResNet-50 and VGG-16 are powerful architectures of convolutional neural networks, but they reveal many weaknesses when operating on low-end computers. The ultimate goal of this research is to create a model for image splicing detection working well in limited memory machines. The study proposes the model, which is the improvement of VGG-16 applying residual network (ResNet). As a result, the proposed model achieves a test accuracy of 92.5% while the ResNet-50 gives an accuracy of 85.6% after 20 epochs of training 9,319 images from the CASIA v2.0 dataset, which are used for forgery classification. The result proves the efficiency of the proposed model for image splicing detection, especially when working on low-end computers

Palmitoyl-acyl Carrier Protein Thioesterase in Cotton (Gossypium hirsutum L.): Biochemical and Molecular Characterization of a Major Mechanism for the Regulation of Palmitic Acid Content

The relatively high level of palmitic acid (22 mol%) in cottonseeds may be due in part to the activity of a palmitoyl-acyl carrier protein (ACP) thioesterase (PATE). In embryo extracts, PATE activity was highest at the maximum rate of reserve accumulation (oil and protein). The cotton FatB mRNA transcript abundance also peaked during this developmental stage, paralleling the profiles of PATE enzyme activity and seed oil accumulation. A cotton FatB cDNA clone was isolated by screening a cDNA library with a heterologous Arabidopsis FatB probe (Pirtle et al., 1999, Plant and Cell Physiology 40: 155-163). The predicted amino acid sequence of the cotton PATE preprotein had 63% identity to the Arabidopsis FatB thioesterase sequence, suggesting that the cotton cDNA clone probably encoded a FatB-type thioesterase. When acyl-CoA synthetase-minus E. coli mutants expressed the cotton cDNA, an increase in 16:0 free fatty acid content was measured in the culture medium. In addition, acyl-ACP thioesterase activity assays in E. coli lysates revealed that there was a preference for palmitoyl-ACP over oleoyl-ACP in vitro, indicating that the cotton putative FatB cDNA encoded a functional thioesterase with a preference for saturated acyl-ACPs over unsaturated acyl-ACPs (FatA). Overexpression of the FatB cDNA in transgenic cotton resulted in elevated levels of palmitic acid in transgenic somatic embryos compared to control embryos. Expression of the anti-sense FatB cDNA in transgenic cotton plants produced some plants with a dwarf phenotype. These plants had significantly smaller mature leaves, all with smaller cells, suggesting that these plants may have less palmitic acid available for incorporation into extraplastidial membrane lipids during cell expansion. Thus manipulation of FatB expression in cotton directly influenced palmitic acid levels. Collectively, data presented in this dissertation support the hypothesis that there indeed is a palmitoyl-ACP thioesterase in cotton, encoded by the isolated FatB cDNA, which plays a major role in regulating palmitic acid content of extraplastidial complex glycerolipids. This work forms the basis for future studies of the influence of palmitic acid content on plant membrane function and provides a key target for the metabolic engineering of palmitic acid levels in storage oils of developing cottonseeds

STRUCTURE, MICROSTRUCTURE, AND PIEZOELECTRIC PROPERTIES OF KNLNS-BNKZ LEAD-FREE CERAMICS UNDER THE EFFECT OF DIFFERENT SINTERING TEMPERATURES

Samples of 0.96(K0.48Na0.48Li0.04)(Nb0.95Sb0.05)O3-0.04Bi0.5(Na0.82K0.18)0.5ZrO3 piezoelectric ceramic were fabricated with conventional ceramic techniques and sintered at different temperatures. The effect of sintering temperature (TS) on the structure, microstructure, and piezoelectric properties of the ceramics was studied in detail. The experimental results showed that with an increase of the TS temperature, the structure of the ceramics transformed from an orthorhombic-tetragonal mixed phase (O-T) at TS £ 1100 °C into a rhombohedral-tetragonal (R-T) mixed phase with a dense microstructure of uniform grain size at TS = 1110 °C. When TS was further increased (TS ³ 1120 °C), the ceramics showed only a rhombohedral phase (R). The ceramics showed the best electrical properties for TS = 1110 °C at which the rhombohedral and tetragonal (R-T) phases coexist. Specifically, the ceramic density reached its highest value (4.22 g/cm3), the electromechanical coupling coefficients kp and kt were 0.46 and 0.50, respectively, and the piezoelectric coefficient d33 was 245 pC/N.Samples of 0.96(K0.48Na0.48Li0.04)(Nb0.95Sb0.05)O3-0.04Bi0.5(Na0.82K0.18)0.5ZrO3 piezoelectric ceramic were fabricated with conventional ceramic techniques and sintered at different temperatures. The effect of sintering temperature (TS) on the structure, microstructure, and piezoelectric properties of the ceramics was studied in detail. The experimental results showed that with an increase of the TS temperature, the structure of the ceramics transformed from an orthorhombic-tetragonal mixed phase (O-T) at TS £ 1100 °C into a rhombohedral-tetragonal (R-T) mixed phase with a dense microstructure of uniform grain size at TS = 1110 °C. When TS was further increased (TS ³ 1120 °C), the ceramics showed only a rhombohedral phase (R). The ceramics showed the best electrical properties for TS = 1110 °C at which the rhombohedral and tetragonal (R-T) phases coexist. Specifically, the ceramic density reached its highest value (4.22 g/cm3), the electromechanical coupling coefficients kp and kt were 0.46 and 0.50, respectively, and the piezoelectric coefficient d33 was 245 pC/N

CHARACTERIZATION OF CARBONATED STEELMAKING SLAG AND ITS POTENTIAL APPLICATION IN CONSTRUCTION

In the current context of Vietnam, the solid waste of steel slag occupy ground for dumping and lead to severe environmental issue due to their high content of heavy metal and fine dust. For the purpose of large-scale recycling steel slag, up to now one of the most relevant solutions is to use as aggregate for asphaltic and/or cement concrete. In this paper, we aim to analyze the influence of the accelerated carbonation condition in the laboratory on the physio-chemical properties of carbonated steel slag. Materials composition were characterized by using different analysis techniques of XRD, SEM, TG and others measurement of the physio-properties (density, L.O.I..) were also realized with regards to the requirement of the national standard for concrete aggregate. In conclusion, we will discuss the effect of reaction condition and on the feasibility of implementing this specific treatment method on a larger scale.Keywords: steelmaking slag, solid waste, CO2 sequestration, accelerated carbonation, concrete aggregate