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Full-Text Articles in Physical Sciences and Mathematics
Late Palaeolithic Core Reduction Strategies In Dhofar, Oman, Yamandu Hilbert, Jeffrey Rose, Richard Roberts
Late Palaeolithic Core Reduction Strategies In Dhofar, Oman, Yamandu Hilbert, Jeffrey Rose, Richard Roberts
Richard G Roberts
Systematic surveys conducted in the Dhofar Governorate of Oman have produced over 300 surface sites, as well as excavation of in situ archaeological deposits. A number of these assemblages have been classified as part of the Nejd Leptolithic Tradition (NLT).This study describes a selection of these assemblages from sites distributed across the southern and central Najd plateau in Dhofar,including both surface scatters and stratified rock shelters. The NLT is broadly characterized by the reduction of blades struck from single-platform cores with flat flaking surfaces, in conjunction with the faconnage manufacture of bifacial implements. Based on technological analysis and artefact conjoins, …
A Pipeline For Structured Light Bathymetric Mapping, Gabrielle Inglis, Clara Smart, J. Vaughn, Chris Roman
A Pipeline For Structured Light Bathymetric Mapping, Gabrielle Inglis, Clara Smart, J. Vaughn, Chris Roman
Christopher N. Roman
This paper details a methodology for using structured light laser imaging to create high resolution bathymetric maps of the sea floor. The system includes a pair of stereo cameras and an inclined 532nm sheet laser mounted to a remotely operated vehicle (ROV). While a structured light system generally requires a single camera, a stereo vision set up is used here for in-situ calibration of the laser system geometry by triangulating points on the laser line. This allows for quick calibration at the survey site and does not require precise jigs or a controlled environment. A batch procedure to extract the …
Index Factorised Image Adaptive Vector Quantisation, Jamshid Shanbehzadeh, Philip Ogunbona
Index Factorised Image Adaptive Vector Quantisation, Jamshid Shanbehzadeh, Philip Ogunbona
Professor Philip Ogunbona
No abstract provided.
Face To Face Communications In Multiplayer Online Games: A Real-Time System, Ce Zhan, Wanqing Li, Farzad Safaei, Philip Ogunbona
Face To Face Communications In Multiplayer Online Games: A Real-Time System, Ce Zhan, Wanqing Li, Farzad Safaei, Philip Ogunbona
Professor Philip Ogunbona
Multiplayer online games (MOG) bring HCI into a new era of human-human interactions in computer world. Although current MOG provide more interactivity and social interaction in the virtual world, natural facial expression as a key factor in emulating face to face communications has been neglected by game designers. In this work, we propose a real-time automatic system to recognize players’ facial expressions, so that the recognition results can be used to drive the MOG’s “facial expression engine” instead of “text commands”. Our major contributions are the evaluation, improvement and efficient implementation of existing algorithms to build a real-time system that …
Human Detection With Contour-Based Local Motion Binary Patterns, Duc Thanh Nguyen, Philip Ogunbona, Wanqing Li
Human Detection With Contour-Based Local Motion Binary Patterns, Duc Thanh Nguyen, Philip Ogunbona, Wanqing Li
Professor Philip Ogunbona
This paper presents a human detection method using contour- based local motion features. The local motion is encoded using a variant of the popular Local Binary Pattern (LBP) called Non-Redundant Local Binary Pattern (NRLBP) descriptor computed on the difference image of two consecutive frames. In addition, the local motion features are extracted along the human's boundary contour. Localising features on the contours has the advantage of utilizing a precise human shape description. A motivation of the proposed method is that most of informative movements are performed on boundary contours of the body parts, e.g. legs of pedestrians. Evaluation of the …
Texture Analysis Using Gabor Wavelets, Golshah Naghdy, Jianli Wang, Philip Ogunbona
Texture Analysis Using Gabor Wavelets, Golshah Naghdy, Jianli Wang, Philip Ogunbona
Professor Philip Ogunbona
Receptive field profiles of simple cells in the visual cortex have been shown to resemble even- symmetric or odd-symmetric Gabor filters. Computational models employed in the analysis of textures have been motivated by two-dimensional Gabor functions arranged in a multi-channel architecture. More recently wavelets have emerged as a powerful tool for non-stationary signal analysis capable of encoding scale-space information efficiently. A multi-resolution implementation in the form of a dyadic decomposition of the signal of interest has been popularized by many researchers. In this paper, Gabor wavelet configured in a 'rosette' fashion is used as a multi-channel filter-bank feature extractor for …
Human Motion Simulation And Action Corpus, Gang Zheng, Wanqing Li, Philip Ogunbona, Liju Dong, Igor Kharitonenko
Human Motion Simulation And Action Corpus, Gang Zheng, Wanqing Li, Philip Ogunbona, Liju Dong, Igor Kharitonenko
Professor Philip Ogunbona
Acquisition of large scale good quality training samples is becoming a major issue in machine learning based human motion analysis. This paper presents a method to simulate continuous gross human body motion with the intention to establish a human motion corpus for learning and recognition. The simulation is achieved by a temporal-spatialtemporal decomposition of human motion into actions, joint actions and actionlets based on the human kinematic model. The actionlet models the primitive moving phase of a joint and represents the muscle movement governed by kinesiological principles. Joint actions and body actions are constructed from actionlets through constrained concatenation and …
Smoke Detection In Videos Using Non-Redundant Local Binary Pattern-Based Features, Hongda Tian, Wanqing Li, Philip Ogunbona, Duc Thanh Nguyen, Ce Zhan
Smoke Detection In Videos Using Non-Redundant Local Binary Pattern-Based Features, Hongda Tian, Wanqing Li, Philip Ogunbona, Duc Thanh Nguyen, Ce Zhan
Professor Philip Ogunbona
This paper presents a novel and low complexity method for real-time video-based smoke detection. As a local texture operator, Non-Redundant Local Binary Pattern (NRLBP) is more discriminative and robust to illumination changes in comparison with original Local Binary Pattern (LBP), thus is employed to encode the appearance information of smoke. Non-Redundant Local Motion Binary Pattern (NRLMBP), which is computed on the difference image of consecutive frames, is introduced to capture the motion information of smoke. Experimental results show that NRLBP outperforms the original LBP in the smoke detection task. Furthermore, the combination of NRLBP and NRLMBP, which can be considered …
A Novel Multi-Image Query Techniques For Automatic Query Concept Capture, Fenghui Ren, Philip Ogunbona, Lei Ye
A Novel Multi-Image Query Techniques For Automatic Query Concept Capture, Fenghui Ren, Philip Ogunbona, Lei Ye
Professor Philip Ogunbona
No abstract provided.
Description Of Evolutional Changes In Image Time Sequences Using Mpeg-7 Visual Descriptors, Lei Ye, Lingzhi Cao, Philip Ogunbona, Wanqing Li
Description Of Evolutional Changes In Image Time Sequences Using Mpeg-7 Visual Descriptors, Lei Ye, Lingzhi Cao, Philip Ogunbona, Wanqing Li
Professor Philip Ogunbona
Colour and texture visual descriptors have been developed to represent structural features of images, mainly under the Query-by- Example (QBE) image retrieval paradigm. This paper explores applicability of MPEG-7 visual descriptors to describe and measure evolutional changes in image time sequences, using a fruit rotting process as an example. The research found that MPEG-7 visual descriptors can be applied to describe evolutional changes in image time sequences. The experimental results are provided using bananas captured in image time sequences. The results show the desirable monotonicity of description metrics of MPEG-7 similarity matching for image time sequences and their sensitivity to …
Preliminary Model Tests For The Design Of A Gliding Deep Water Elevator, Christopher Roman, T. Gregory, E. Martin, A. Sanguinetti, J. Drummond
Preliminary Model Tests For The Design Of A Gliding Deep Water Elevator, Christopher Roman, T. Gregory, E. Martin, A. Sanguinetti, J. Drummond
Christopher N. Roman
This paper presents progress on the design of a "smart elevator" to be used in conjunction with deep sea ROV operations. Deep sea elevators are gravity driven untethered platforms used to deliver and or return items from the sea floor. Elevators are used when items are too large or heavy to be handled by the ROV, or when the turn around time to recover and redeploy the ROV system for sample removal is prohibitive. Unfortunately, efficiency is complicated by the precision with which elevators can be landed at a specific location on the bottom and recovered on the surface because …
Design Of A Gas Tight Water Sampler For Auv Operations, Christopher Roman, R. Camilli
Design Of A Gas Tight Water Sampler For Auv Operations, Christopher Roman, R. Camilli
Christopher N. Roman
This paper presents the design and preliminary test results for a small gas tight water sampler intended to work on scientific AUVs. In recent years AUVs have developed into reliable platforms capable of carrying a wide variety of environmental sensors for in-situ chemical measurements. Physical sample collection however remains difficult, due to the combination of space, power and complexity constraints inherent in working with autonomous platforms. The AUV sampler is a small (12 cm times 85 cm) cylindrical package designed to collect eight 20 ml gas tight volumes of water, with each sample maintained at high pressure to depths of …
Consistency Based Error Evaluation For Deep Sea Bathymetric Mapping With Robotic Vehicles, Christopher Roman, Hanumant Singh
Consistency Based Error Evaluation For Deep Sea Bathymetric Mapping With Robotic Vehicles, Christopher Roman, Hanumant Singh
Christopher N. Roman
This paper presents a method to evaluate the mapping error present in point cloud terrain maps created using robotic vehicles and range sensors. This work focuses on mapping environments where no a priori ground truth is available and self consistency is the only available check against false artifacts and errors. The proposed error measure is based on a disparity measurement between common sections of the environment that have been imaged multiple times. This disparity measure highlights inconsistency in the terrain map by showing regions where multiple overlapping point clouds do not fit together well. This error measure provides the map …
Improved Vehicle Based Multibeam Bathymetry Using Sub-Maps And Slam, Christopher Roman, Hanumant Singh
Improved Vehicle Based Multibeam Bathymetry Using Sub-Maps And Slam, Christopher Roman, Hanumant Singh
Christopher N. Roman
This paper presents an algorithm to improve sub-sea acoustic multibeam bottom mapping based on the simultaneous mapping and localization (SLAM) methodology. Multibeam bathymetry from underwater water vehicles can yield valuable large scale terrain maps of the sea door, but the overall accuracy of these maps is typically limited by the accuracy of the vehicle position estimates. The solution presented here uses small bathymetric patches created over short time scales in a sub-mapping context. These patches are registered with respect to one another and assembled in a single coordinate frame to produce a more accurate terrain estimate and provide improved renavigation …
Optical And Acoustic Habitat Characterization With The Seabed Auv, Hanumant Singh, Ryan Eustice, Oscar Pizarro, Christopher Roman
Optical And Acoustic Habitat Characterization With The Seabed Auv, Hanumant Singh, Ryan Eustice, Oscar Pizarro, Christopher Roman
Christopher N. Roman
The Seabed AUV is an Autonomous Underwater Vehicle (AUV) built to serve as a readily available and operationally simple tool for high resolution imaging. It is a hover-capable vehicle that performs optical sensing with a 12 bit 1280/spl times/1024 CCD camera and acoustic high resolution mapping using an MST 300 kHz sidescan and a 675 kHz pencil beam bathymetric sonar. The AUV has been designed for operations from small vessels with minimal support equipment. It has an operational depth of 2000 meters and at 1 m/s can run for up to 10 hours. In this paper we report on the …
The Seabed Auv — A Platform For High Resolution Imaging, Hanumant Singh, Ryan Eustice, Christopher Roman, Oscar Pizarro
The Seabed Auv — A Platform For High Resolution Imaging, Hanumant Singh, Ryan Eustice, Christopher Roman, Oscar Pizarro
Christopher N. Roman
No abstract provided.
Estimation Of Error In Large Area Underwater Photomosaics Using Vehicle Navigation Data, C. Roman, H. Singh
Estimation Of Error In Large Area Underwater Photomosaics Using Vehicle Navigation Data, C. Roman, H. Singh
Christopher N. Roman
Creating geometrically accurate photomosaics of underwater sites using images collected from an AUV or ROV is a difficult task due to dimensional errors which grow as a function of 3D image distortion and the mosaicking process. Although photomosiacs are accurate locally their utility for accurately representing a large survey area is jeopardized by this error growth. Evaluating the error in a mosaic is the first step in creating globally accurate photomosaics of an unstructured environment with bounded error. Using vehicle navigation data and sensor offsets it is possible to estimate the error present in large area photomosaics independent of the …
A New Autonomous Underwater Vehicle For Imaging Research, C. Roman, O. Pizarro, R. Eustice, H. Singh
A New Autonomous Underwater Vehicle For Imaging Research, C. Roman, O. Pizarro, R. Eustice, H. Singh
Christopher N. Roman
Currently, unmanned underwater vehicles either tend to be cumbersome and complex to run, or operationally simple, but not quite suitable platforms for deep water imaging. This paper presents an alternative design in the form of a new low cost and easier to use autonomous underwater vehicle (AUV) for imaging research. The objective of the vehicle is to serve as a readily available and operationally simple tool that allows rapid testing of imaging algorithms in areas such as photomosaicking, 3D image reconstruction from a single camera, image based navigation, and multi-sensor fusion of bathymetry and optical data. These are all current …
Advances In Fusion Of High Resolution Underwater Optical And Acoustic Data, H. Singh, C. Roman, L. Whitcomb, D. Yoerger
Advances In Fusion Of High Resolution Underwater Optical And Acoustic Data, H. Singh, C. Roman, L. Whitcomb, D. Yoerger
Christopher N. Roman
We report efforts to merge data from the complementary modalities of optical and acoustic sensing for obtaining more accurate representations of the seafloor. We show that the principal obstacles to merging the acoustic and optical imaging modalities are the distortions inherent to each modality. The construction of geometrically accurate photomosaics is dominated by incremental errors arising as individual images are scaled and warped to form the photomosaic. For microbathymetric mapping, principal errors arise from sensor position and orientation calibration parameters that affect our ability to construct maps from sonar data that are commensurate with sensor and navigation resolution. We show …