Open-loop characteristics of magnetic suspension systems using electromagnets mounted in a planar array

The open-loop characteristics of a Large-Gap Magnetic Suspension System (LGMSS) were studied and numerical results are presented. The LGMSS considered provides five-degree-of-freedom control. The suspended element is a cylinder that contains a core composed of permanent magnet material. The magnetic actuators are air core electromagnets mounted in a planar array. Configurations utilizing five, six, seven, and eight electromagnets were investigated and all configurations were found to be controllable from coil currents and observable from suspended element positions. Results indicate that increasing the number of coils has an insignificant effect on mode shapes and frequencies

Stability considerations for magnetic suspension systems using electromagnets mounted in a planar array

Mathematical models of a 5, 6, 7, and 8 coil large gap magnetic suspension system (MSDS) are presented. Some of the topics covered include: force and torque equations, reduction of state-space form, natural modes, origins of modes, effect of rotation in azimuth (yaw), future work, and n-coil ring conclusions

Declining Discount Rates: Evidence from the UK

We estimate schedules of declining discount rates for cost benefit analysis in the UK. We highlight the importance of model selection for this task and hence for the evaluation of long-term investments, namely climate change prevention and nuclear build.long-run discounting, state-space models,regime-switching models, climate change policy,nuclear build

Discounting the distant future: How much does model selection affect the certainty equivalent rate?

Evaluating investments with long-term consequences using discount rates that decline with the time horizon, (Declining Discount Rates or DDRs) means that future welfare changes are of greater consequence in present value terms. Recent work in this area has turned towards operationalising the theory and establishing a schedule of DDRs for use in cost benefit analysis. Using US data we make the following points concerning this transition: i) model selection has important implications for operationalising a theory of DDRs that depends upon uncertainty; ii) misspecification testing naturally leads to employing models that account for changes in the interest rate generating mechanism. Lastly, we provide an analysis of the policy implications of DDRs in the context of climate change for the US and show that the use of a state space model can increase valuations by 150% compared to conventional constant discounting.long-run discounting, interest rate forecasting,interest rate forecasting, state-space models,regime-switching models, climate change policy

Quantum Corrections to Newton's Law

We present a new approach to quantum gravity starting from Feynman's formulation for the simplest example, that of a scalar field as the representative matter. We show that we extend his treatment to a calculable framework using resummation techniques already well-tested in other problems. Phenomenological consequences for Newton's law are described.Comment: 7 pages, 1 figure; improved fig., refs;improved discussion;more discussion; proo

Dynamical freeze-out condition in ultrarelativistic heavy ion collisions

We determine the decoupling surfaces for the hydrodynamic description of heavy ion collisions at RHIC and LHC by comparing the local hydrodynamic expansion rate with the microscopic pion-pion scattering rate. The pion $p_T$ spectra for nuclear collisions at RHIC and LHC are computed by applying the Cooper-Frye procedure on the dynamical-decoupling surfaces, and compared with those obtained from the constant-temperature freeze-out surfaces. Comparison with RHIC data shows that the system indeed decouples when the expansion rate becomes comparable with the pion scattering rate. The dynamical decoupling based on the rates comparison also suggests that the effective decoupling temperature in central heavy ion collisions remains practically unchanged from RHIC to LHC.Comment: 7 pages, 9 figure

Elliptic flow in nuclear collisions at the Large Hadron Collider

We use perfect-fluid hydrodynamical model to predict the elliptic flow coefficients in Pb + Pb collisions at the Large Hadron Collider (LHC). The initial state for the hydrodynamical calculation for central $A + A$ collisions is obtained from the perturbative QCD + saturation (EKRT) model. The centrality dependence of the initial state is modeled by the optical Glauber model. We show that the baseline results obtained from the framework are in good agreement with the data from the Relativistic Heavy Ion Collider (RHIC), and show predictions for the $p_T$ spectra and elliptic flow of pions in Pb + Pb collisions at the LHC. Also mass and multiplicity effects are discussed.Comment: 11 pages, 10 figure

Computer games for user engagement in attention deficit hyperactivity disorder (ADHD) monitoring and therapy

State-of-the-art computer games and psychological tests for symptom monitoring and therapy in Attention Deficit Hyperactivity Disorder (ADHD) are explored and reviewed. Three foci for research studies are identified: task (human performance) focus; educational focus; medical/clinical focus. It is found that game designs in the literature include a variety of tests of cognition mostly dependent on attention and executive functions (inhibitory motor control, working memory, interference suppression) which involve reactions to stimuli on computer (or mobile phone) screens. In addition, based on the measurement of neural pathways that can be accessed by Brain Computer Interfaces, there are several applications of games that employ biofeedback and demand the user to control aspects of their brain activity to play them, with the aim of improving function. A number of games have been used in clinical studies for self-monitoring and therapy, some of these controlled with comparators such as treatment as usual or cognitive therapies, or with the individual as their own control, where efficacy is evaluated by measuring behavioural and functional outcomes on measurement instruments such as ADHD or behavioural trait questionnaires or other cognitive tests. Other applications of games include education and raising awareness of mental health conditions to reduce stigma. The paper then presents and proposes designs of new games that are based on psychological tests or tasks that aim to monitor or improve attention, inhibitory and/or motor activity including Continuous Performance Tests, Go/No-go and Stop-signal tasks

Computer games for user engagement in attention deficit hyperactivity disorder (ADHD) monitoring and therapy

State-of-the-art computer games and psychological tests for symptom monitoring and therapy in Attention Deficit Hyperactivity Disorder (ADHD) are explored and reviewed. Three foci for research studies are identified: task (human performance) focus; educational focus; medical/clinical focus. It is found that game designs in the literature include a variety of tests of cognition mostly dependent on attention and executive functions (inhibitory motor control, working memory, interference suppression) which involve reactions to stimuli on computer (or mobile phone) screens. In addition, based on the measurement of neural pathways that can be accessed by Brain Computer Interfaces, there are several applications of games that employ biofeedback and demand the user to control aspects of their brain activity to play them, with the aim of improving function. A number of games have been used in clinical studies for self-monitoring and therapy, some of these controlled with comparators such as treatment as usual or cognitive therapies, or with the individual as their own control, where efficacy is evaluated by measuring behavioural and functional outcomes on measurement instruments such as ADHD or behavioural trait questionnaires or other cognitive tests. Other applications of games include education and raising awareness of mental health conditions to reduce stigma. The paper then presents and proposes designs of new games that are based on psychological tests or tasks that aim to monitor or improve attention, inhibitory and/or motor activity including Continuous Performance Tests, Go/No-go and Stop-signal tasks

Highlights of the SLD Physics Program at the SLAC Linear Collider

Starting in 1989, and continuing through the 1990s, high-energy physics witnessed a flowering of precision measurements in general and tests of the standard model in particular, led by e+e- collider experiments operating at the Z0 resonance. Key contributions to this work came from the SLD collaboration at the SLAC Linear Collider. By exploiting the unique capabilities of this pioneering accelerator and the SLD detector, including a polarized electron beam, exceptionally small beam dimensions, and a CCD pixel vertex detector, SLD produced a broad array of electroweak, heavy-flavor, and QCD measurements. Many of these results are one of a kind or represent the world's standard in precision. This article reviews the highlights of the SLD physics program, with an eye toward associated advances in experimental technique, and the contribution of these measurements to our dramatically improved present understanding of the standard model and its possible extensions.Comment: To appear in 2001 Annual Review of Nuclear and Particle Science; 78 pages, 31 figures; A version with higher resolution figures can be seen at http://www.slac.stanford.edu/pubs/slacpubs/8000/slac-pub-8985.html; Second version incorporates minor changes to the tex