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 Meniere’s Syndrome — A systematic review

Meniere’s 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 Meniere’s 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 Meniere’s 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 Meniere’s 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 ev­er-grow­ing de­mand for high­er beam en­er­gies has dra­mat­i­cal­ly in­creased the risk of RF break­down, lim­it­ing the max­i­mum achiev­able ac­cel­er­at­ing gra­di­ent. Field emis­sion is the most fre­quent­ly en­coun­tered RF break­down where it oc­curs at re­gions of lo­cal­ly en­hanced elec­tric field. Elec­trons ac­cel­er­at­ed across the cav­i­ty as they tun­nel through the sur­face in the pres­ence of mi­cro­scop­ic de­fects. Upon Im­pact, most of the ki­net­ic en­er­gy is con­vert­ed into heat and stress. This can in­flict ir­re­versible dam­age to the sur­face, cre­at­ing ad­di­tion­al field emis­sion sites. This work aims to in­ves­ti­gate, through sim­u­la­tion, the physics in­volved dur­ing both emis­sion and im­pact of elec­trons. A newly de­vel­oped 3D field model of an 805 MHz cav­i­ty is gen­er­at­ed by COM­SOL Mul­ti­physics. Elec­tron track­ing is per­formed using a Mat­lab based code, cal­cu­lat­ing the rel­e­vant pa­ram­e­ters need­ed by em­ploy­ing fourth Order Runge Kutta in­te­gra­tion. By study­ing such be­haviours in 3D, it is pos­si­ble to iden­ti­fy how the cav­i­ty sur­face can alter the local RF field and lead to break­down and sub­se­quent dam­ages. The ul­ti­mate aim is to in­tro­duce new sur­face stan­dards to en­sure bet­ter cav­i­ty per­for­mance

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