title: Improving Bags-of-Words model for object categorization

authors: Zhang, Edmond Yiwen

abstract: In the past decade, Bags-of-Words (BOW) models have become popular for the task of object recognition, owing to their good performance and simplicity. Some of the most effective recent methods for computer-based object recognition work by detecting and extracting local image features, before quantizing them according to a codebook rule such as k-means clustering, and classifying these with conventional classifiers such as Support Vector Machines and Naive Bayes.

In this thesis, a Spatial Object Recognition Framework is presented that consists of the four main contributions of the research. 

The first contribution, frequent keypoint pattern discovery, works by combining pairs and triplets of frequent keypoints in order to discover intermediate representations for object classes. Based on the same frequent keypoints principle, algorithms for locating the region-of-interest in training images is then discussed. 
Extensions to the successful Spatial Pyramid Matching scheme, in order to better capture spatial relationships, are then proposed. The pairs frequency histogram and shapes frequency histogram work by capturing more redefined spatial information between local image features.
Finally, alternative techniques to Spatial Pyramid Matching for capturing spatial information are presented. The proposed techniques, variations of binned log-polar histograms, divides the image into grids of different scale and different orientation. Thus captures the distribution of image features both in distance and orientation explicitly.

Evaluations on the framework are focused on several recent and popular datasets, including image retrieval, object recognition, and object categorization. Overall, while the effectiveness of the framework is limited in some of the datasets, the proposed contributions are nevertheless powerful improvements of the BOW model.

text: Improving Bags-of-Words model for object categorization In the past decade, Bags-of-Words (BOW) models have become popular for the task of object recognition, owing to their good performance and simplicity. Some of the most effective recent methods for computer-based object recognition work by detecting and extracting local image features, before quantizing them according to a codebook rule such as k-means clustering, and classifying these with conventional classifiers such as Support Vector Machines and Naive Bayes.

In this thesis, a Spatial Object Recognition Framework is presented that consists of the four main contributions of the research. 

The first contribution, frequent keypoint pattern discovery, works by combining pairs and triplets of frequent keypoints in order to discover intermediate representations for object classes. Based on the same frequent keypoints principle, algorithms for locating the region-of-interest in training images is then discussed. 
Extensions to the successful Spatial Pyramid Matching scheme, in order to better capture spatial relationships, are then proposed. The pairs frequency histogram and shapes frequency histogram work by capturing more redefined spatial information between local image features.
Finally, alternative techniques to Spatial Pyramid Matching for capturing spatial information are presented. The proposed techniques, variations of binned log-polar histograms, divides the image into grids of different scale and different orientation. Thus captures the distribution of image features both in distance and orientation explicitly.

Evaluations on the framework are focused on several recent and popular datasets, including image retrieval, object recognition, and object categorization. Overall, while the effectiveness of the framework is limited in some of the datasets, the proposed contributions are nevertheless powerful improvements of the BOW model.

year: 2013

title: Effects on adhesion molecule expression and lymphocytes in the bovine mammary gland following intra-mammary immunisation

authors: Hodgkinson, A.J.

subjects: bovine

abstract: Changes to adhesion molecule expression and lymphocyte populations were evaluated in alveolar mammary tissue collected from cows following an immunisation protocol that involved intra-mammary inoculation to induce an IgA response in mammary secretions. The right quarters of the udder were immunised; the left side acted as a control. Antibody titres in secretions showed that at least two animals responded with antigen-specific IgA. Numbers of T-lymphocytes were 4-fold higher in immunised glands compared with controls (P < 0.05). IgA-, IgM- and IgG-positive cell numbers were significantly higher (P < 0.01) in immunised glands compared with controls in three of the four cows. No mucosal addressin molecule-1 (MAdCAM-1), vascular cell-adhesion molecule-1 (VCAM-1) or peripheral node addressin (PNAd) protein expression was detected on smaller venules that stained positively for von Willebrand factor in alveolar mammary tissues, from either immunised or control glands. Both VCAM-1 and PNAd were detected on smaller venules in supramammary lymph nodes, however, there was no significant difference between immunised and control glands. Quantification of MAdCAM-1 mRNA showed very low expression in both immunised and control alveolar tissue compared with Peyer's patch positive-control tissue. These findings suggest that the bovine mammary gland is capable of a mucosal antibody response; however, MAdCAM-1 is not involved with lymphocyte homing to the mammary gland in this species.

text: Effects on adhesion molecule expression and lymphocytes in the bovine mammary gland following intra-mammary immunisation Changes to adhesion molecule expression and lymphocyte populations were evaluated in alveolar mammary tissue collected from cows following an immunisation protocol that involved intra-mammary inoculation to induce an IgA response in mammary secretions. The right quarters of the udder were immunised; the left side acted as a control. Antibody titres in secretions showed that at least two animals responded with antigen-specific IgA. Numbers of T-lymphocytes were 4-fold higher in immunised glands compared with controls (P < 0.05). IgA-, IgM- and IgG-positive cell numbers were significantly higher (P < 0.01) in immunised glands compared with controls in three of the four cows. No mucosal addressin molecule-1 (MAdCAM-1), vascular cell-adhesion molecule-1 (VCAM-1) or peripheral node addressin (PNAd) protein expression was detected on smaller venules that stained positively for von Willebrand factor in alveolar mammary tissues, from either immunised or control glands. Both VCAM-1 and PNAd were detected on smaller venules in supramammary lymph nodes, however, there was no significant difference between immunised and control glands. Quantification of MAdCAM-1 mRNA showed very low expression in both immunised and control alveolar tissue compared with Peyer's patch positive-control tissue. These findings suggest that the bovine mammary gland is capable of a mucosal antibody response; however, MAdCAM-1 is not involved with lymphocyte homing to the mammary gland in this species.

year: 2009

title: A cultural encounter through volunteer tourism: Towards the ideals of sustainable tourism?

authors: McIntosh, Alison J.

subjects: cultural tourism

abstract: International volunteering is increasingly recognised as a form of alternative tourism. However, the nature of the ‘alternative’ experience gained, and the ensuing narrative between host and volunteer, remains under-explored in published research, especially in volunteer tourism research within a cultural context in a developed nation. This paper examines the nexus between volunteer tourism and cultural tourism in the search for alternative and sustainable experiences through tourism. Qualitative research using in-depth interviews, diaries and participant observation was conducted to examine the pre-, during and post-trip experiences of 12 Australian visitors undertaking organised volunteer activities in an indigenous Maori community in the North Island of New Zealand during January 2005. Members of the indigenous Maori community were also interviewed to provide an important host perspective. Findings suggest that the nature of the interaction and cultural experiences gained were perceived as mutually beneficial and seemingly different from those gained from traditional cultural products. In particular, the volunteers experienced an alternative Maori cultural product and engaged in a different narrative with their Maori hosts through their volunteer work, one rich in authentic cultural content, genuine and reflective of modern Maori life in New Zealand society.

text: A cultural encounter through volunteer tourism: Towards the ideals of sustainable tourism? International volunteering is increasingly recognised as a form of alternative tourism. However, the nature of the ‘alternative’ experience gained, and the ensuing narrative between host and volunteer, remains under-explored in published research, especially in volunteer tourism research within a cultural context in a developed nation. This paper examines the nexus between volunteer tourism and cultural tourism in the search for alternative and sustainable experiences through tourism. Qualitative research using in-depth interviews, diaries and participant observation was conducted to examine the pre-, during and post-trip experiences of 12 Australian visitors undertaking organised volunteer activities in an indigenous Maori community in the North Island of New Zealand during January 2005. Members of the indigenous Maori community were also interviewed to provide an important host perspective. Findings suggest that the nature of the interaction and cultural experiences gained were perceived as mutually beneficial and seemingly different from those gained from traditional cultural products. In particular, the volunteers experienced an alternative Maori cultural product and engaged in a different narrative with their Maori hosts through their volunteer work, one rich in authentic cultural content, genuine and reflective of modern Maori life in New Zealand society.

year: 2007