Supplementary notes on some Antarctic rocks and minerals

In the proceedings of the Royal Society of New South Wales, Vol. XXIX., page 461, et seq., appears a paper, read in 1895, on Antarctic Rocks collected by Mr. C. E. Borchgrevink. The authors are Professor David, Messrs. W. F. Smeeth, and J. A. Schofield. A brief summary of this valuable paper will be interesting, more especially as since then there has been donated to the Tasmanian Museum a small collection of Antarctic rocks and minerals. The paper mentioned is sub-divided into two parts : I. Introductory notes about Antarctica, II. Petrology of the rocks collected by Mr. C. E. Borchgrevink

Notes on a "Fayalite Basalt" from One Tree Point

The rock on which these notes have been written occurs as a basaltic flow in a small promontory, on the far side from Hobart, of Sandy Bay. The geological age of basaltic flows and tuffs is given by Mr. R. M. Johnston (Systematic Account of the Geology of Tasmania, p. 249 et seq.) as being younger than the tertiary leaf-beds, and from the occurrence of this rock and its associates, sections of which can clearly be seen on the Brown's River Road, there seems to be no reason for doubting that the age ascribed is approximately correct

Improved image-based deformation measurement for geotechnical applications

This paper describes and benchmarks a new implementation of image-based deformation measurement for geotechnical applications. The updated approach combines a range of advances in image analysis algorithms and techniques best suited to geotechnical applications. Performance benchmarking of the new approach has used a series of artificial images subjected to prescribed spatially varying displacement fields. An improvement by at least a factor of 10 in measurement precision is achieved relative to the most commonly used particle image velocimetry (PIV) approach for all deformation modes, including rigid-body displacements, rotations, and strains (compressive and shear). Lastly, an example analysis of a centrifuge model test is used to demonstrate the capabilities of the new approach. The strain field generated by penetration of a flat footing and an entrapped sand plug into an underlying clay layer is computed and compared for both the current and updated algorithms. This analysis demonstrates that the enhanced measurement precision improves the clarity of the interpretation. </jats:p

On the occurrence of a new species of Garnet at Port Cygnet

The Igneous rock containing this Garnet as a constant accessory constituent, occurs as an outcrop about 6 feet wide on the beach between Port Cygnet and Lymington. It is intruded between other volcanic rocks, and, as far as could be ascertained from a hasty examination, seems to be the only exposure in this locality. From fossils found it is probably contemporaneous with the Permo- Carboniferous sediments

Visual-vestibular motion cueing assessment in maritime rotorcraft flight simulators

Confidence in the Modelling and Simulation (M&S) tools used in flight simulators depends upon the identification of the fidelity requirements for a particular application. The critical M&S elements integrated into the helicopter-ship dynamic interface simulation environment are motion and visual cueing, the flight dynamics model, unsteady ship's airwake and deck motion. The paper reports the results of a piloted flight simulation experiment conducted in a full-motion simulator, to study the effects of varying the visual and vestibular motion cueing fidelity on the pilot's perception, task performance and workload. Three different motion tuning sets were tested in three visual cueing scenarios for a representative SH-60B 'Seahawk' helicopter landing on a naval single-spot destroyer at different wind and sea-state conditions. It was found that when high-fidelity vestibular motion was provided to the pilot, the dependency on the visuals to capture aircraft state information was reduced. Similarly, when the high-fidelity visual cueing was provided, the pilot perceived balanced and synchronised overall motion cues leading to reduced workload and improved task performance. Moreover, the individual and combined effect of visual-vestibular fidelity was found to be more noticeable at higher wind and sea conditions, for which an 'Optimised' vestibular motion tuning set and a High Visual Cueing scenario combination was obtained, this led to reduced pilot workload and improved simulated maritime helicopter operational capability

Initial progress in developing a predictive simulation tool to inform helicopter ship operations

The study presented in this paper is part of the project underway at the University of Liverpool (UoL) to develop a high-fidelity simulation tool that has a predictive capability to inform and support Ship Helicopter Operating Limit (SHOL) trials. The paper reports preliminary progress in developing a desktop based predictive simulation tool that uses a pilot modelling technique to represent the integrated Helicopter Ship Dynamic Interface (HSDI) simulation environment. The approach consists of: a pursuit pilot model, linearized vehicle dynamics, full standard deck landing task, ship motion and equivalent ship airwake turbulence. The tool was initially tested by performing a simplified land-based task for validation purposes. It was then used in HSDI simulations of an SH-60B helicopter operating to a generic single-spot naval frigate. Time and frequency domain comparisons have been made between the predictive tool and piloted simulation flight trials conducted in UoL's Heliflight-R full-motion simulator. It was found that the performance of the predictive tool in maintaining sufficient clearance between the aircraft and the ship whilst rejecting airwake disturbances is well within the desired task performance boundaries. These preliminary investigations show that the tool is capable of representing the dynamics of a pilot in the HSDI environment

Stellar Dynamics and Black Holes

Chandrasekhar's most important contribution to stellar dynamics was the concept of dynamical friction. I briefly review that work, then discuss some implications of Chandrasekhar's theory of gravitational encounters for motion in galactic nuclei.Comment: Talk presented at the "Chandrasekhar Centenary Conference" (2010

Preliminary progress in establishing motion fidelity requirements for maritime rotorcraft flight simulators

Copyright © 2018 by AHS International, Inc. All rights reserved. The research presented in this paper is part of a project underway at the University of Liverpool (UoL) which aims to develop overall simulation fidelity requirements for maritime rotorcraft flight simulators. This requires a structured examination of individual Modelling and Simulation (M&S) elements, such as motion and visual cues, flight dynamics model and ship airwake integration. The paper reports the initial results of motion cueing research that has been conducted to assess and optimise the motion drive laws and determine high fidelity motion cueing for simulated shipboard operations. To do this, an objective technique, Vestibular Motion Perception Error (VMPE), has been developed. The technique was utilised to optimise the motion cues in UoL's Heliflight-R simulator for a simulated helicopter landing on an aircraft carrier in a turbulent environment. Four motion tuning sets were derived offline and experimentally tested. Results show the influence of different motion cues and airwake conditions on the pilot's overall self-motion perception, control strategy and task performance. It was found that high-fidelity motion cueing becomes more desirable for the pilot at higher airwake wind conditions, for which an 'Optimised' motion setting was obtained using the new technique, than at lower airwake turbulence conditions

Nemo: a computational tool for analyzing nematode locomotion

The nematode Caenorhabditis elegans responds to an impressive range of chemical, mechanical and thermal stimuli and is extensively used to investigate the molecular mechanisms that mediate chemosensation, mechanotransduction and thermosensation. The main behavioral output of these responses is manifested as alterations in animal locomotion. Monitoring and examination of such alterations requires tools to capture and quantify features of nematode movement. In this paper, we introduce Nemo (nematode movement), a computationally efficient and robust two-dimensional object tracking algorithm for automated detection and analysis of C. elegans locomotion. This algorithm enables precise measurement and feature extraction of nematode movement components. In addition, we develop a Graphical User Interface designed to facilitate processing and interpretation of movement data. While, in this study, we focus on the simple sinusoidal locomotion of C. elegans, our approach can be readily adapted to handle complicated locomotory behaviour patterns by including additional movement characteristics and parameters subject to quantification. Our software tool offers the capacity to extract, analyze and measure nematode locomotion features by processing simple video files. By allowing precise and quantitative assessment of behavioral traits, this tool will assist the genetic dissection and elucidation of the molecular mechanisms underlying specific behavioral responses.Comment: 12 pages, 2 figures. accepted by BMC Neuroscience 2007, 8:8