Automatic Alignment of 3D Multi-Sensor Point Clouds

Automatic 3D point cloud alignment is a major research topic in photogrammetry, computer vision and computer graphics. In this research, two keypoint feature matching approaches have been developed and proposed for the automatic alignment of 3D point clouds, which have been acquired from different sensor platforms and are in different 3D conformal coordinate systems. The first proposed approach is based on 3D keypoint feature matching. First, surface curvature information is utilized for scale-invariant 3D keypoint extraction. Adaptive non-maxima suppression (ANMS) is then applied to retain the most distinct and well-distributed set of keypoints. Afterwards, every keypoint is characterized by a scale, rotation and translation invariant 3D surface descriptor, called the radial geodesic distance-slope histogram. Similar keypoints descriptors on the source and target datasets are then matched using bipartite graph matching, followed by a modified-RANSAC for outlier removal. The second proposed method is based on 2D keypoint matching performed on height map images of the 3D point clouds. Height map images are generated by projecting the 3D point clouds onto a planimetric plane. Afterwards, a multi-scale wavelet 2D keypoint detector with ANMS is proposed to extract keypoints on the height maps. Then, a scale, rotation and translation-invariant 2D descriptor referred to as the Gabor, Log-Polar-Rapid Transform descriptor is computed for all keypoints. Finally, source and target height map keypoint correspondences are determined using a bi-directional nearest neighbour matching, together with the modified-RANSAC for outlier removal. Each method is assessed on multi-sensor, urban and non-urban 3D point cloud datasets. Results show that unlike the 3D-based method, the height map-based approach is able to align source and target datasets with differences in point density, point distribution and missing point data. Findings also show that the 3D-based method obtained lower transformation errors and a greater number of correspondences when the source and target have similar point characteristics. The 3D-based approach attained absolute mean alignment differences in the range of 0.23m to 2.81m, whereas the height map approach had a range from 0.17m to 1.21m. These differences meet the proximity requirements of the data characteristics and the further application of fine co-registration approaches

Optimum Organization of Gins and Warehouses for Marketing Cotton in the Oklahoma -Texas Plains

Agricultural Economic

The political role of religious pacifism during the inter-war years

The purpose of this paper is to attempt to make a judgment concerning the effectiveness of the selected political actions of certain religious peace groups during the inter-war years. Information was obtained from the Portland State University Library, the Multnomah County Library, the Methodist Episcopal Church of Oregon office, the national offices of the American Friends Service Committee, the National Council of Churches, and the Fellowship of Reconciliation. Conversations with people who had been involved with the peace movement included Roland Bainton, Jerome Davis, G. Bernhard Fedde, Carlin Kapper-Johnson, and Mark Chamberlin. Periodicals that provided much of the information about events and opinion during the twenties and thirties were: the New York Times, The New Republic, The Nation, Harper’s Magazine, and The World Tomorrow. A number of books concerning the peace movement were especially useful; those books were: Boeckel’s Turn Toward Peace, Bowman’s The Church of the Brethren and War, 1708-1941, Curti’s Peace or War, Pickett’s For More Than Bread, and Vining’s Friend of Life. Information from those sources showed that the religious pacifists were able to influence the course of events relating to the Mexican Crisis of 1927, the Washington Disarmament Conference, the Peace Pact to Outlaw War, the Russian famine relief effort, and the status of conscientious objectors. In some way the final outcome of each of these issues was affected by the actions of religious pacifists: a possible war with Mexico was avoided, disarmament was attempted, war was outlawed, many lives were saved in Russia, and conscientious objectors were given a legal status that was better than what they had had during the First World War

Investigation of Selected Personality Need-Structure, Value and Attitude Characteristics of Student and Cooperating Teachers in Elementary Education at Oklahoma State University

Educational Administratio

Enabling factors in the open labour market and strategies used by individuals with rheumatoid arthritis to maintain their employment

Bibliography: leaves 124-131.The objective of this research was to determine the enabling factors that employed individuals with rheumatoid arthritis encounter in the open labour market, and strategies they use to keep their jobs. One hundred individuals with rheumatoid arthritis between the ages of 18 and 65 years and employed in the South African open labour market participated in the study. Participants were recruited from two tertiary hospitals and two private practices in the Western Cape. Participants completed a questionnaire and afterwards six volunteers were selected for a one-hour semi-structured interview