Absorbing systematic effects to obtain a better background model in a search for new physics

This paper presents a novel approach to estimate the Standard Model backgrounds based on modifying Monte Carlo predictions within their systematic uncertainties. The improved background model is obtained by altering the original predictions with successively more complex correction functions in signal-free control selections. Statistical tests indicate when sufficient compatibility with data is reached. In this way, systematic effects are absorbed into the new background model. The same correction is then applied on the Monte Carlo prediction in the signal region. Comparing this method to other background estimation techniques shows improvements with respect to statistical and systematical uncertainties. The proposed method can also be applied in other fields beyond high energy physics

Enhancing Perception of Complex Sculptural Forms using Interactive Real-time Ray tracing

This paper looks at experiments into using real-time ray tracing to significantly enhance shape perception of complex three-dimensional digitally created structures. The author is a computational artist whose artistic practice explores the creation of intricate organic three-dimensional forms using simulation of morphogenesis. The generated forms are often extremely detailed, comprising tens of millions of cellular primitives. This often makes depth perception of the resulting structures difficult. His practice has explored various techniques to create presentable artefacts from the data, including high resolution prints, animated videos, stereoscopic installations, 3D printing and virtual reality. The author uses ray tracing techniques to turn the 3D data created from his morphogenetic simulations into visible artefacts. This is typically a time-consuming process, taking from seconds to minutes to create a single frame. The latest generation of graphics processing units offer dedicated hardware to accelerate ray tracing calculations. This potentially allows the generation of ray traced images, including self-shadowed complex structures and multiple levels of transparency, from new viewpoints at frame rates capable of real-time interaction. The author presents the results of his experiments using this technology with the aim of providing significantly enhanced perception of his generated three-dimensional structures by allowing user-initiated interaction to generate novel views, and utilizing depth cues such as stereopsis, depth from motion and defocus blurring. The intention is for these techniques to be usable to present new exhibitable works in a gallery context

Waypoint based online trajectory generation and following control for the ACT/FHS

New research activities on DLR’s EC135 ACT/FHS research helicopter, has led to new challenges for the automatic flight control software of this testbed. Noise abatement flights, innovative automatic approach trajectories and other topics all require the helicopter to follow a set of waypoints as precisely as possible. This paper presents a new algorithm which is capable of generating curvature-continuous trajectories. A modification of the natural cubic spline algorithm is presented, which allows to incrementally fit cubic splines with defined boundary conditions through subsets of the waypoint list. By joining several of these splines with matching boundary condition, a continuous trajectory is obtained. This approach allows to distribute the computational load of the cubic spline calculation over several execution cycles of the real-time system. Based on these results, two controllers to follow the generated trajectories are developed and compared in terms of their ability to reduce and stabilize the distance between the trajectory and the vehicle. The approach is verified in DLRs Air Vehicle Simulator (AVES)

HID-1 is required for sensing CO₂ level in the pharynx.

<p>(<b>A</b>) One-day-old adult <i>hid-1(yg316)</i> and N2 worms were exposed to 5%, 10%, or 20% CO₂ balanced with 21% O₂ and N₂. The pumping rate was measured under a dissecting microscope while the animals were exposed to the different gas mixtures. A gas mixture of 21% O₂ and 79% N₂ was used as a normal air control. (<b>B</b>) The inhibition of the pumping rate of the pharynx after exposure to high CO₂ level in <i>hid-1(yg316)</i> allele mutants is significantly reduced. Similarly, the inhibition of the pumping rate of the pharynx after exposure to high CO₂ level is reduced in other <i>hid-1</i> allele mutants (<i>sa772</i> and <i>sa1058</i>). Transgenic expression of HID-1 fused to eGFP in the <i>sa722</i> or <i>yg316</i> background (<i>hid-1(sa722</i>);HID-1::GFP or <i>hid-1(yg316)</i>;HID-1::GFP) is sufficient to restore the effect of high CO₂ level on the pumping rate back to the wild-type phenotype. In all experiments <i>N</i>≥30 animals. Different groups were compared by one-way ANOVA followed by <i>t</i> test. ***<i>P</i><.001. Error bars indicate SEM.</p