41,751 research outputs found
Multiple relaxations in temporal planning
CRIKEY is a planner that separates out the scheduling from the classical parts of temporal planning. This can be seen as a relaxation of the temporal information during the classical planning phase. Relaxations in planning are used to guide the search. However, the quality of the relaxation greatly affects the performance of the planner, and in some cases can lead the search into a dead end. This can happen whilst separating out the planning and scheduling problems, leading to the production of an unschedulable plan. CRIKEY can detect these cases and change the relaxation accordingly
Kinematic functions for the 7 DOF robotics research arm
The Robotics Research Model K-1207 manipulator is a redundant 7R serial link arm with offsets at all joints. To uniquely determine joint angles for a given end-effector configuration, the redundancy is parameterized by a scalar variable which corresponds to the angle between the manipulator elbow plane and the vertical plane. The forward kinematic mappings from joint-space to end-effector configuration and elbow angle, and the augmented Jacobian matrix which gives end-effector and elbow angle rates as a function of joint rates, are also derived
Exploring the evidence base for acupuncture in the treatment of Meniereās Syndrome ā A systematic review
Meniereās syndrome is a long-term, progressive disease that damages the balance and hearing
parts of the inner ear. To address the paucity of information on which evidence-based treatment
decisions should be made, a systematic review of acupuncture for Meniereās syndrome was
undertaken. The method used was a systematic review of English and Chinese literature, from
six databases for randomized, non-randomized and observational studies. All studies were
critically appraised and a narrative approach to data synthesis was adopted. Twenty-seven
studies were included in this review (9 in English and 18 in Chinese languages): three randomized
controlled trials, three non-randomized controlled studies and four pre-test, post-test
designs. All but one of the studies was conducted in China. The studies covered body acupuncture,
ear acupuncture, scalp acupuncture, fluid acupuncture point injection and moxibustion.
The studies were of varying quality. The weight of evidence, across all study types, is of beneficial
effect from acupuncture, for those in an acute phase or those who have had Meniereās
syndrome for a number of years. The review reinforces the importance of searching for studies
from English and Chinese literature. The transferability of the findings from China to a
Western context needs confirmation. Further research is also needed to clarify questions
around the appropriate frequency and number of treatment/courses of acupuncture. The
weight of evidence suggests a potential benefit of acupuncture for persons with Meniereās
disease, including those in an acute phase and reinforces the importance of searching for
published studies in the Chinese language
The magnetic structure of Gd_2Ti_2O_7
We attempt to solve the magnetic structure of the gadolinium analogue of
`spin-ice', using a mixture of experimental and theoretical assumptions. The
eventual predictions are essentially consistent with both the Mossbauer and
neutron measurements but are unrelated to previous proposals. We find two
possible distinct states, one of which is coplanar and the other is fully
three-dimensional. We predict that close to the initial transition the
preferred state is coplanar but that at the lowest temperature the ground-state
becomes fully three-dimensional. Unfortunately the energetics are consequently
complicated. There is a dominant nearest-neighbour Heisenberg interaction but
then a compromise solution for lifting the final degeneracy resulting from a
competition between longer-range Heisenberg interactions and direct dipolar
interactions on similar energy scales.Comment: 12 pages, 15 figure
3D Simulation of the Effects of Surface Defects on Field Emitted Electrons
The evĀer-growĀing deĀmand for highĀer beam enĀerĀgies has draĀmatĀiĀcalĀly inĀcreased the risk of RF breakĀdown, limĀitĀing the maxĀiĀmum achievĀable acĀcelĀerĀatĀing graĀdiĀent. Field emisĀsion is the most freĀquentĀly enĀcounĀtered RF breakĀdown where it ocĀcurs at reĀgions of loĀcalĀly enĀhanced elecĀtric field. ElecĀtrons acĀcelĀerĀatĀed across the cavĀiĀty as they tunĀnel through the surĀface in the presĀence of miĀcroĀscopĀic deĀfects. Upon ImĀpact, most of the kiĀnetĀic enĀerĀgy is conĀvertĀed into heat and stress. This can inĀflict irĀreĀversible damĀage to the surĀface, creĀatĀing adĀdiĀtionĀal field emisĀsion sites. This work aims to inĀvesĀtiĀgate, through simĀuĀlaĀtion, the physics inĀvolved durĀing both emisĀsion and imĀpact of elecĀtrons. A newly deĀvelĀoped 3D field model of an 805 MHz cavĀiĀty is genĀerĀatĀed by COMĀSOL MulĀtiĀphysics. ElecĀtron trackĀing is perĀformed using a MatĀlab based code, calĀcuĀlatĀing the relĀeĀvant paĀramĀeĀters needĀed by emĀployĀing fourth Order Runge Kutta inĀteĀgraĀtion. By studyĀing such beĀhaviours in 3D, it is posĀsiĀble to idenĀtiĀfy how the cavĀiĀty surĀface can alter the local RF field and lead to breakĀdown and subĀseĀquent damĀages. The ulĀtiĀmate aim is to inĀtroĀduce new surĀface stanĀdards to enĀsure betĀter cavĀiĀty perĀforĀmance
Unsupervised vector-based classification of single-molecule charge transport data
The stochastic nature of single-molecule charge transport measurements requires collection of large data sets to capture the full complexity of a molecular system. Data analysis is then guided by certain expectations, for example, a plateau feature in the tunnelling current distance trace, and the molecular conductance extracted from suitable histogram analysis. However, differences in molecular conformation or electrode contact geometry, the number of molecules in the junction or dynamic effects may lead to very different molecular signatures. Since their manifestation is a priori unknown, an unsupervised classification algorithm, making no prior assumptions regarding the data is clearly desirable. Here we present such an approach based on multivariate pattern analysis and apply it to simulated and experimental single-molecule charge transport data. We demonstrate how different event shapes are clearly separated using this algorithm and how statistics about different event classes can be extracted, when conventional methods of analysis fail
In situ analysis for intelligent control
We report a pilot study on in situ analysis of backscatter data for intelligent control of a scientific instrument on an Autonomous Underwater Vehicle (AUV) carried out at the Monterey Bay Aquarium Research Institute (MBARI). The objective of the study is to investigate techniques which use machine intelligence to enable event-response scenarios. Specifically we analyse a set of techniques for automated sample acquisition in the water-column using an electro-mechanical "Gulper", designed at MBARI. This is a syringe-like sampling device, carried onboard an AUV. The techniques we use in this study are clustering algorithms, intended to identify the important distinguishing characteristics of bodies of points within a data sample. We demonstrate that the complementary features of two clustering approaches can offer robust identification of interesting features in the water-column, which, in turn, can support automatic event-response control in the use of the Gulper
Complementary and Alternative Medicine (CAM) Therapies in the Treatment of Meniere's Syndrome: Reviewing the Evidence for Acupuncture
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