Spatial Light Modulators for the Manipulation of Individual Atoms

We propose a novel dipole trapping scheme using spatial light modulators (SLM) for the manipulation of individual atoms. The scheme uses a high numerical aperture microscope to map the intensity distribution of a SLM onto a cloud of cold atoms. The regions of high intensity act as optical dipole force traps. With a SLM fast enough to modify the trapping potential in real time, this technique is well suited for the controlled addressing and manipulation of arbitrarily selected atoms.Comment: 9 pages, 5 figure

Modelling vehicles acceleration during overtaking manoeuvres

[EN] Abstract: Overtaking manoeuvre is a key issue for two-lane rural roads. These roads should provide sufficient overtaking sight distance (OSD) at certain locations to allow faster vehicles to pass slower ones. However, overtaking requires occupying the opposing lane, which represents a serious safety concern. Severity of overtaking related crashes is very high, compared with other manoeuvres. The development of advanced driver assistance systems (ADAS) for overtaking is being a complex task. Only few systems have been developed, but are not still in use. This research incorporated accurate data of real manoeuvres to improve the knowledge of the phenomenon. The trajectory of the overtaking vehicles on the left lane was observed. An instrumented vehicle measured the overtaking time and distance, the abreast position, and the initial and final speed of 180 drivers that passed it during a field experiment. Six different kinematic models (such as uniform acceleration or linear variation of acceleration) were calibrated. Generally, drivers started to accelerate before changing to the opposing lane. These models may be applied to ADAS, to estimate OSD and to improve microsimulation models.Part of this research was included in the project 'Desarrollo de modelos de distancias de visibilidad de adelantamiento', with reference code TRA2010-21736 and subsidised by the Spanish Ministery of Economy and Competitivity. The authors also thank Prof Dr Sayed, from University of British Columbia, for his valuable review.Llorca Garcia, C.; Moreno, AT.; García García, A. (2016). Modelling vehicles acceleration during overtaking manoeuvres. IET Intelligent Transport Systems. 10(3):206-215. https://doi.org/10.1049/iet-its.2015.0035S206215103Gray, R., & Regan, D. M. (2005). Perceptual Processes Used by Drivers During Overtaking in a Driving Simulator. Human Factors: The Journal of the Human Factors and Ergonomics Society, 47(2), 394-417. doi:10.1518/0018720054679443Basilio, N., Morice, A. H. P., Marti, G., & Montagne, G. (2015). High- and Low-Order Overtaking-Ability Affordances. Human Factors: The Journal of the Human Factors and Ergonomics Society, 57(5), 879-894. doi:10.1177/0018720815583581Morice, A. H. P., Diaz, G. J., Fajen, B. R., Basilio, N., & Montagne, G. (2015). An Affordance-Based Approach to Visually Guided Overtaking. Ecological Psychology, 27(1), 1-25. doi:10.1080/10407413.2015.991641Farah, H., Bekhor, S., & Polus, A. (2009). Risk evaluation by modeling of passing behavior on two-lane rural highways. Accident Analysis & Prevention, 41(4), 887-894. doi:10.1016/j.aap.2009.05.006Hassan, Y., Easa, S. M., & El Halim, A. O. A. (1996). Passing sight distance on two-lane highways: Review and revision. Transportation Research Part A: Policy and Practice, 30(6), 453-467. doi:10.1016/0965-8564(95)00032-1Wang, Y., & Cartmell, M. P. (1998). New Model for Passing Sight Distance on Two-Lane Highways. Journal of Transportation Engineering, 124(6), 536-545. doi:10.1061/(asce)0733-947x(1998)124:6(536)Sparks, G. A., Neudorf, R. D., Robinson, J. B. L., & Good, D. (1993). Effect of Vehicle Length on Passing Operations. Journal of Transportation Engineering, 119(2), 272-283. doi:10.1061/(asce)0733-947x(1993)119:2(272)Hanley, P. F., & Forkenbrock, D. J. (2005). Safety of passing longer combination vehicles on two-lane highways. Transportation Research Part A: Policy and Practice, 39(1), 1-15. doi:10.1016/j.tra.2004.09.001Khoury, J. E., & Hobeika, A. G. (2012). Integrated Stochastic Approach for Risk and Service Estimation: Passing Sight Distance Application. Journal of Transportation Engineering, 138(5), 571-579. doi:10.1061/(asce)te.1943-5436.0000366Jenkins, J. M., & Rilett, L. R. (2004). Application of Distributed Traffic Simulation for Passing Behavior Study. Transportation Research Record: Journal of the Transportation Research Board, 1899(1), 11-18. doi:10.3141/1899-02Rakha, H., Ahn, K., & Trani, A. (2004). Development of VT-Micro model for estimating hot stabilized light duty vehicle and truck emissions. Transportation Research Part D: Transport and Environment, 9(1), 49-74. doi:10.1016/s1361-9209(03)00054-3Polus, A., Livneh, M., & Frischer, B. (2000). Evaluation of the Passing Process on Two-Lane Rural Highways. Transportation Research Record: Journal of the Transportation Research Board, 1701(1), 53-60. doi:10.3141/1701-07Harwood, D. W., Gilmore, D. K., & Richard, K. R. (2010). Criteria for Passing Sight Distance for Roadway Design and Marking. Transportation Research Record: Journal of the Transportation Research Board, 2195(1), 36-46. doi:10.3141/2195-05Hegeman, G., Tapani, A., & Hoogendoorn, S. (2009). Overtaking assistant assessment using traffic simulation. Transportation Research Part C: Emerging Technologies, 17(6), 617-630. doi:10.1016/j.trc.2009.04.010Milanés, V., Llorca, D. F., Villagrá, J., Pérez, J., Fernández, C., Parra, I., … Sotelo, M. A. (2012). Intelligent automatic overtaking system using vision for vehicle detection. Expert Systems with Applications, 39(3), 3362-3373. doi:10.1016/j.eswa.2011.09.024Isermann, R., Mannale, R., & Schmitt, K. (2012). Collision-avoidance systems PRORETA: Situation analysis and intervention control. Control Engineering Practice, 20(11), 1236-1246. doi:10.1016/j.conengprac.2012.06.003Petrov, P., & Nashashibi, F. (2014). Modeling and Nonlinear Adaptive Control for Autonomous Vehicle Overtaking. IEEE Transactions on Intelligent Transportation Systems, 15(4), 1643-1656. doi:10.1109/tits.2014.2303995Llorca, C., & García, A. (2011). Evaluation of Passing Process on Two-Lane Rural Highways in Spain with New Methodology Based on Video Data. Transportation Research Record: Journal of the Transportation Research Board, 2262(1), 42-51. doi:10.3141/2262-05Llorca, C., Moreno, A. T., García, A., & Pérez-Zuriaga, A. M. (2013). Daytime and Nighttime Passing Maneuvers on a Two-Lane Rural Road in Spain. Transportation Research Record: Journal of the Transportation Research Board, 2358(1), 3-11. doi:10.3141/2358-01Llorca, C., Moreno, A. T., Pérez-Zuriaga, A. M., & García, A. (2013). Influence of age, gender and delay on overtaking dynamics. IET Intelligent Transport Systems, 7(2), 174-181. doi:10.1049/iet-its.2012.0147Khoury, J. E., & Hobeika, A. (2007). Incorporating Uncertainty into the Estimation of the Passing Sight Distance Requirements. Computer-Aided Civil and Infrastructure Engineering, 22(5), 347-357. doi:10.1111/j.1467-8667.2007.00491.xRakha, H., Snare, M., & Dion, F. (2004). Vehicle Dynamics Model for Estimating Maximum Light-Duty Vehicle Acceleration Levels. Transportation Research Record: Journal of the Transportation Research Board, 1883(1), 40-49. doi:10.3141/1883-05Fitzpatrick, K., Chrysler, S. T., & Brewer, M. (2012). Deceleration Lengths for Exit Terminals. Journal of Transportation Engineering, 138(6), 768-775. doi:10.1061/(asce)te.1943-5436.000038

Developing a predictive modelling capacity for a climate change-vulnerable blanket bog habitat: Assessing 1961-1990 baseline relationships

Aim: Understanding the spatial distribution of high priority habitats and developing predictive models using climate and environmental variables to replicate these distributions are desirable conservation goals. The aim of this study was to model and elucidate the contributions of climate and topography to the distribution of a priority blanket bog habitat in Ireland, and to examine how this might inform the development of a climate change predictive capacity for peat-lands in Ireland. Methods: Ten climatic and two topographic variables were recorded for grid cells with a spatial resolution of 1010 km, covering 87% of the mainland land surface of Ireland. Presence-absence data were matched to these variables and generalised linear models (GLMs) fitted to identify the main climatic and terrain predictor variables for occurrence of the habitat. Candidate predictor variables were screened for collinearity, and the accuracy of the final fitted GLM was evaluated using fourfold cross-validation based on the area under the curve (AUC) derived from a receiver operating characteristic (ROC) plot. The GLM predicted habitat occurrence probability maps were mapped against the actual distributions using GIS techniques. Results: Despite the apparent parsimony of the initial GLM using only climatic variables, further testing indicated collinearity among temperature and precipitation variables for example. Subsequent elimination of the collinear variables and inclusion of elevation data produced an excellent performance based on the AUC scores of the final GLM. Mean annual temperature and total mean annual precipitation in combination with elevation range were the most powerful explanatory variable group among those explored for the presence of blanket bog habitat. Main conclusions: The results confirm that this habitat distribution in general can be modelled well using the non-collinear climatic and terrain variables tested at the grid resolution used. Mapping the GLM-predicted distribution to the observed distribution produced useful results in replicating the projected occurrence of the habitat distribution over an extensive area. The methods developed will usefully inform future climate change predictive modelling for Irelan