Enhanced spatial pyramid matching using log-polar-based image subdivision and representation

This paper presents a new model for capturing spatial information for object categorization with bag-of-words (BOW). BOW models have recently become popular for the task of object recognition, owing to their good performance and simplicity. Much work has been proposed over the years to improve the BOW model, where the Spatial Pyramid Matching (SPM) technique is the most notable. We propose a new method to exploit spatial relationships between image features, based on binned log-polar grids. Our model works by partitioning the image into grids of different scales and orientations and computing histogram of local features within each grid. Experimental results show that our approach improves the results on three diverse datasets over the SPM technique

3D face recognition using multiview keypoint matching

A novel algorithm for 3D face recognition based point cloud rotations, multiple projections, and voted keypoint matching is proposed and evaluated. The basic idea is to rotate each 3D point cloud representing an individual’s face around the x, y or z axes, iteratively projecting the 3D points onto multiple 2.5D images at each step of the rotation. Labelled keypoints are then extracted from the resulting collection of 2.5D images, and this much smaller set of keypoints replaces the original face scan and its projections in the face database. Unknown test faces are recognised firstly by performing the same multiview keypoint extraction technique, and secondly, the application of a new weighted keypoint matching algorithm. In an extensive evaluation using the GavabDB 3D face recognition dataset (61 subjects, 9 scans per subject), our method achieves up to 95% recognition accuracy for faces with neutral expressions only, and over 90% accuracy for face recognition where expressions (such as a smile or a strong laugh) and random faceoccluding gestures are permitted

Improving face gender classification by adding deliberately misaligned faces to the training data

A novel method of face gender classifier construction is proposed and evaluated. Previously, researchers have assumed that a computationally expensive face alignment step (in which the face image is transformed so that facial landmarks such as the eyes, nose, chin, etc, are in uniform locations in the image) is required in order to maximize the accuracy of predictions on new face images. We, however, argue that this step is not necessary, and that machine learning classifiers can be made robust to face misalignments by automatically expanding the training data with examples of faces that have been deliberately misaligned (for example, translated or rotated). To test our hypothesis, we evaluate this automatic training dataset expansion method with two types of image classifier, the first based on weak features such as Local Binary Pattern histograms, and the second based on SIFT keypoints. Using a benchmark face gender classification dataset recently proposed in the literature, we obtain a state-of-the-art accuracy of 92.5%, thus validating our approach

Improving Bag-of-Words model with spatial information

Bag-of-Words (BOW) models have recently become popular for the task of object recognition, owing to their good performance and simplicity. Much work has been proposed over the years to improve the BOW model, where the Spatial Pyramid Matching technique is the most notable. In this work, we propose three novel techniques to capture more re_ned spatial information between image features than that provided by the Spatial Pyramids. Our techniques demonstrate a performance gain over the Spatial Pyramid representation of the BOW model

SIFTing the relevant from the irrelevant: Automatically detecting objects in training images

Many state-of-the-art object recognition systems rely on identifying the location of objects in images, in order to better learn its visual attributes. In this paper, we propose four simple yet powerful hybrid ROI detection methods (combining both local and global features), based on frequently occurring keypoints. We show that our methods demonstrate competitive performance in two different types of datasets, the Caltech101 dataset and the GRAZ-02 dataset, where the pairs of keypoint bounding box method achieved the best accuracies overall

Development of a music organizer for children

Software development for children is challenging; children have their own needs, which often are not met by ‘grown up’ software. We focus on software for playing songs and managing a music collection—tasks that children take great interest in, but for which they have few or inappropriate tools. We address this situation with the design of a new music management system, created with children as design partners: the Kids Music Box

Climate Change, WTO Law, and China

Combating climate change is one of the most important areas for international cooperation and negotiation. The urgency of the climate crisis requires countries, especially large carbon emitters such as China, to be more active in taking climate actions. This Note mainly focuses on the two most important trade-related climate policies for reducing carbon emissions: border carbon adjustment and low-carbon subsidies. Both policies have or would likely raise legal challenges under the existing WTO legal framework. This Note introduces the two policies, analyzes why they are disputed among WTO Members, discusses China’s viewpoints, and suggests the possible actions that China can take in helping to mitigate trade policy conflicts over carbon emissions under the current WTO trade system

Studies on the Total Synthesis of Some Biologically Active Natural Products: Neocosmosin A and the Discoipyrroles

The body of this thesis is comprised of four scientific journal articles and a patent. It is preceded by an overview that contextualizes all of this submitted/published work. The first major part of this thesis is comprised of Publication 1. This is a review concerned with the chemical syntheses of the cochliomycins, including congener A, and certain related resorcylic acid lactones (RALs). pecifically, Publication 1 reviews the recently published literature on the cochliomycins and related, co-occurring RALs and is accompanied by a brief commentary on the source organisms and certain of their biological properties. It serves to contextualize some of the author’s other published research incorporated in the thesis. The second major part of this thesis is comprised of Publication 2. This details work concerned with establishing the true structure of the marine-derived RAL neocosmosin A. Specifically, the structure, A, originally assigned to neocosmosin A was synthesized with the key steps involving olefin-cross metathesis, ring-closing metathesis, palladium- catalyzed Meinwald rearrangement and Mitsunobu esterification reactions. A late-stage and simple modification to the reaction sequence also provided the enantiomer B that, in fact, represents the true structure of the natural product. The third major part of this thesis is comprised of Publication 3. This details the development of modular total syntheses of the marine-derived alkaloids discoipyrroles A and B. Specifically, the intermediates C and D (see below) were prepared from (parent) pyrrole using Ullmann-Goldberg and Suzuki-Miyaura cross-coupling, Vilsmeier-Haack formylation, electrophilic bromination, and Wittig olefination reactions as key steps. A late stage MoOPH-mediated oxidative cyclization reaction was then employed to assemble the novel heterobicyclic core of the target discoipyrroles. The fourth major part of this thesis is comprised of Publication 4. This details the first total synthesis of the most structurally complex member of the small family of marine- derived discoipyrroles, namely congener D. This synthesis, which used methodology developed during the course of the aforementioned syntheses of the discoipyrroles A and B, involved, as key steps, the MoOPH-mediated oxidative cyclization of precursor E and this was followed by conjugate addition and redox processes. The fifth and final part of this thesis is comprised of Publication 5. This patent details inventions related to methods for preparing a variety of discoipyrrole-like compounds and novel analogues, as well as pharmaceutical compositions comprising these compounds and their possible use in therapeutic settings. For example, compound F, which incorporates a discoipyrrole-like core structure, was synthesized in four steps from indole and involving the aforementioned MoOPH-mediated oxidative cyclization as one of the key processes. The Appendices to the thesis are comprised of a series of reports arising from single- crystal X-ray analyses of certain key compounds synthesized by the author. Drs Jas Ward, Paul Carr or Anthony Willis, members of the Research School of Chemistry’s Crystallographic Analysis Unit, conducted these analyses