9,076 research outputs found
The response of lake margin sedimentary systems to climatically driven lake level fluctuations : Middle Devonian, Orcadian Basin, Scotland
ACKNOWLEDGEMENTS M. J. Newman is gratefully acknowledged for his identification of fossil fish specimens from the Easter Ross coast which helped in confirmation of the position of the Achanarras fish bed in this region. The Inverness Field Club and the Carnegie Trust are thanked by SDA for financial support of fieldwork undertaken. Nigel Trewin is acknowledged for inspiring a long-lived interest in the Devonian of Northern Scotland which has led to some fantastic journeys. Gary Nichols and Alberto Saez are thanked for constructive reviewsPeer reviewedPostprin
Self-Calibration of Cameras with Euclidean Image Plane in Case of Two Views and Known Relative Rotation Angle
The internal calibration of a pinhole camera is given by five parameters that
are combined into an upper-triangular calibration matrix. If the
skew parameter is zero and the aspect ratio is equal to one, then the camera is
said to have Euclidean image plane. In this paper, we propose a non-iterative
self-calibration algorithm for a camera with Euclidean image plane in case the
remaining three internal parameters --- the focal length and the principal
point coordinates --- are fixed but unknown. The algorithm requires a set of point correspondences in two views and also the measured relative
rotation angle between the views. We show that the problem generically has six
solutions (including complex ones).
The algorithm has been implemented and tested both on synthetic data and on
publicly available real dataset. The experiments demonstrate that the method is
correct, numerically stable and robust.Comment: 13 pages, 7 eps-figure
Determining Hybridization in Jack Pine and Lodgepole Pine from British Columbia
This study was conducted to find wood quality evidence of hybridization between jack pine (Pinus banksiana) and lodgepole pine (Pinus contorta var. latifolia) in northeast British Columbia (BC). To determine if wood and fiber traits could be used as distinguishing features among jack pine, lodgepole pine, and their hybrids, differences in morphology and wood and fiber traits were related to the genetic identity of each sample. Thirty samples each of pure lodgepole pine, pure jack pine, and potential hybrids were collected from the Prince George area of BC, the Smoky Lake area of Alberta, and the Fort Nelson region of BC, respectively. Two 10-mm cores (bark to bark) were taken from each tree and analyzed for fiber length and coarseness, microfibril angle (MFA), basic density, earlywood:latewood ratios, and cell dimensions. Needle and cone morphology was used to distinguish among species groups in the field. Based on genetically identified samples, the fiber traits that best differentiated among pure jack pine, lodgepole pine, and hybrids were MFA and cell area
Sacrococcygeal germ-cell tumours - the Red Cross War Memorial Children's hospital experience, 1980 - 1996
Objective. To document the experience of Red Cross War Memorial Children's Hospital in the treatment of sacrococcygeal germ-eell tumours.Patients. Twenty-seven patients with sacrococcygeal germ-cell tumours were treated in our hospital from 1980 to 1996.Design. A retrospective review of these patients' records was undertaken.Results. There were 19 female and 8 male patients. Seventeen (63%) presented in the neonatal period, 13 on the first day of life. Complete surgical resection of the tumour was achieved in all patients with mature or immature teratomas (20 patients) and in 2 neonates with malignant tumours. The first of these 2 neonates, with a malignant teratoma, was not given chemotherapy and remains well 10 years later. The second, with a yolk-sac tumour, also received no initial chemotherapy. He relapsed at the age of 9 months and was successfully treated with repeat excision and chemotherapy. All 5 patients first diagnosed after the age of 1 year had malignant tumours. These patients had incomplete surgical resection (3) or biopsy only (2), and 3 were successfully treated with chemotherapy. One patient relapsed with yolksac tumour after initial complete resection cif a mature teratoma. She was successfully treated with repeat surgery and chemotherapy
Developing an On-Line Interactive Health Psychology Module.
On-line teaching material in health psychology was developed which ensured a range of students could access appropriate material for their course and level of study. This material has been developed around the concept of smaller 'content chunks' which can be combined into whole units of learning (topics), and ultimately, a module. On the basis of the underlying philosophy that the medium is part of the message, we considered interactivity to be a key element in engaging the student with the material. Consequently, the key aim of this development was to stimulate and engage students, promoting better involvement with the academic material, and hence better learning. It was hoped that this was achieved through the development of material including linked programmes and supporting material, small Java Scripts and basic email, forms and HTML additions. This material is outlined as are some of the interactive activities introduced, and the preliminary student and tutor experience described
The Indian family on UK reality television: Convivial culture in salient contexts
This is the author's accepted manuscript. The final published article is available from the link below, copyright 2012 @ the author.This article demonstrates how The Family (2009), a fly-on-the wall UK reality series about a British Indian family, facilitates both current public service broadcasting requirements and mass audience appeal. From a critical cultural studies perspective, the author examines the journalistic and viewer responses to the series where authenticity, universality, and comedy emerge as major themes. Textual analysis of the racialized screen representations also helps locate the series within the contexts of contested multiculturalism, genre developments in reality television and public service broadcasting. Paul Gilroyâs concept of convivial culture is used as a frame in understanding how meanings of the series are produced within a South Asian popular representational space. The author suggests that the social comedy taxonomy is a prerequisite for the making of this particular observational documentary. Further, the popular (comedic) mode of conviviality on which the series depends is both expedient and necessary within the various sociopolitical contexts outlined
Distributed leadership, trust and online communities
This paper analyses the role of distributed leadership and trust in online communities. The team-based informal ethos of online collaboration requires a different kind of leadership from that in formal positional hierarchies. Such leadership may be more flexible and sophisticated, capable of encompassing ambiguity and rapid change. Online leaders need to be partially invisible, delegating power and distributing tasks. Yet, simultaneously, online communities are facilitated by the high visibility and subtle control of expert leaders. This paradox: that leaders need to be both highly visible and invisible as appropriate, was derived from prior research and tested in the analysis of online community discussions using a pattern-matching process. It is argued that both leader visibility and invisibility are important for the facilitation of trusting collaboration via distributed leadership. Advanced leadership responses to complex situations in online communities foster positive group interaction and decision-making, facilitated through active distribution of specific tasks
Quantifying Downstream, Vertical and Lateral Variation in Fluvial Deposits : Implications From the Huesca Distributive Fluvial System
Acknowledgments Author Ben Martin thanks the University of Glasgow for providing funding for this project through the âStressed Environmentsâ scholarship fund. The SAFARI consortium (https://safaridb.com/home) are thanked for providing virtual outcrop models that have been analyzed within this paper. Two anonymous reviewers are thanked for their thorough and constructive comments on this paper.Peer reviewedPublisher PD
Autocalibration with the Minimum Number of Cameras with Known Pixel Shape
In 3D reconstruction, the recovery of the calibration parameters of the
cameras is paramount since it provides metric information about the observed
scene, e.g., measures of angles and ratios of distances. Autocalibration
enables the estimation of the camera parameters without using a calibration
device, but by enforcing simple constraints on the camera parameters. In the
absence of information about the internal camera parameters such as the focal
length and the principal point, the knowledge of the camera pixel shape is
usually the only available constraint. Given a projective reconstruction of a
rigid scene, we address the problem of the autocalibration of a minimal set of
cameras with known pixel shape and otherwise arbitrarily varying intrinsic and
extrinsic parameters. We propose an algorithm that only requires 5 cameras (the
theoretical minimum), thus halving the number of cameras required by previous
algorithms based on the same constraint. To this purpose, we introduce as our
basic geometric tool the six-line conic variety (SLCV), consisting in the set
of planes intersecting six given lines of 3D space in points of a conic. We
show that the set of solutions of the Euclidean upgrading problem for three
cameras with known pixel shape can be parameterized in a computationally
efficient way. This parameterization is then used to solve autocalibration from
five or more cameras, reducing the three-dimensional search space to a
two-dimensional one. We provide experiments with real images showing the good
performance of the technique.Comment: 19 pages, 14 figures, 7 tables, J. Math. Imaging Vi
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