14 research outputs found

    Highly efficient computer oriented octree data structure and neighbours search in 3D GIS

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    Three-dimensional (3D) visualization has given a new perspective in various fields such as urban planning, hydrology, infrastructure modelling and geology. This is due to its capability of handling real world object in more realistic manners, rather than the two-dimensional (2D) approach. However, implementation of 3D spatial analysis in the real world situations has proven to be difficult to comprehend due to the complexity of the algorithm, computational process and time consuming. The existing Geographical Information Systems (GIS) enable 2D and two-and-a-half-dimensional (2.5D) spatial datasets, but less capable of supporting 3D data structures. Recent development in Octree showed that more effort was given to improve the weakness of Octree in finding neighbouring nodes by using various address encoding scheme with specific rule like matrix, lookup table and arithmetic to eliminate the need of tree traversal. Therefore, the purpose of this paper is to propose a new method to speed up the neighbouring search by eliminating the needs of complex operation to extract spatial information from Octree by preserving 3D spatial information directly from the Octree data structure. This new method will be able to achieve O(1) complexity and utilizing Bit Manipulation Instruction 2 (BMI2) to speed up address encoding, extraction and voxel search 1000x compared to generic implementation

    The hierarchical three-dimensional (3D) dynamic water infiltration on multi-layers of soil according to Voronoi sequence nodes based on the three-dimensional triangular irregular network (3D TIN)

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    Understanding soil water infiltration movement has been birthed from extensive interest and concern in the last few decades. The arrangement of particles (i.e. structures and sizes) and the interaction between both the soil and soil water have a profound effect on the soil water infiltration. The challenging task in the soil fluid modelling is the indeterminate spatial extent that has no specific boundaries and the fact that it is difficult to sense. Plenty of investigations and studies have been conducted to measure the water movement. However, less focus has been given on the movement of the dynamic soil water infiltration. This paper will focus on modelling the three-dimensional (3D) soil water infiltrations that flow downward due to the gravitational factor and gradient pressure. The 3D hierarchical soil water infiltration model proposes the integration of techniques which includes the Tree-map to isolate the depth of the soil that acts as a route of the soil water flow from the surface of the terrain to the subsurface flow. Moreover, the 3D Gosper curve is used to represent the soil water flow pattern that is based on the law of gravity and Horton equation, which control the flow of the soil water in the model. The curves that consist of a series of nodes adopt the Three-Dimensional Triangular Irregular Network (3D TIN) which creates a network of flow direction that allows the water to pass through the nodes according to a predetermined sequence. The study area has an average of 8.5 mm total rain and −5 m water level. The soil is divided into a few layers to represent the flow of the soil water according to the sequence of nodes. The soil depth (40, 80, 120, 160 and 200 cm) isolation in the form of Voronoi-shaped polygon nodes allows the soil water to flow down where the depth is chosen based on the soil wetting range of the subsurface soil

    An educationist’s view of blended learning-cognitive apprenticeship complementarity: a Shakespearean classroom experience

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    Blended learning is becoming increasingly popular at higher education due to its adaptability features. One of the notable critiques is that blended learning researchers seem to focus more on classroom delivery while neglecting to understand the underpinning educational theories. In addressing the gap between pedagogical and theoretical considerations, this report which is based on an exploratory case study attempts to examine the linkage between blended learning and cognitive apprenticeship instructional approaches in a literature classroom. In the present study, it is construed that blended learning and cognitive apprenticeship principles are complementary. The fundamentals facilitating teaching and learning in blended face-to-face and online method as outlined by Staker and Horn and Vygotsky’s Zone of Proximal Development (ZPD) have been utilised to structure the process of analysing the complementarity of blended learning and cognitive apprenticeship in literature classroom instruction. The findings revealed that blended learning classroom instructional approaches complement the Method domain of cognitive apprenticeship which consists of modelling, scaffolding, fading, coaching, articulation, reflection and exploration. The study concludes that the role of educational theory underpinned is to enrich the educational experience through collaboration with peers and instructor in any blended learning models

    Is receptive vocabulary knowledge a predictor for english as a second language learners’ level of speaking performance?

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    Research studies from a few decades ago have explored relationship between learners’ vocabulary knowledge and language skills namely speaking, writing, listening and reading. However, there is hardly any study which examines the link between receptive vocabulary knowledge and speaking proficiency of Malaysian learners of English as a second language (ESL). This paper therefore aims to present a study which was conducted to systematically investigate how well receptive vocabulary knowledge predicts the speaking performance of ESL students studying at pre-university level. Seventy Malaysian ESL pre-university students participated in the study. In order to collect the data, the Vocabulary Levels Test (VLT) and a MUET-like speaking assessment were administered. The result reveals that there is no statistically significant correlation between the students’ receptive vocabulary knowledge level and their speaking performance. This study thus concludes that receptive vocabulary knowledge is not a significant predictor of speaking performance of ESL pre-university students
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