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[1] In this study, a new method is developed to investigate the entire life cycle of shallow cumuli in large eddy simulations. Although trained observers have no problem in distinguishing the different life stages of a cloud, this process proves difficult to automate, because cloud-splitting and cloud-merging events complicate the distinction between a single system divided in several cloudy parts and two independent systems that collided. Because the human perception is well equipped to capture and to make sense of these time-dependent three-dimensional features, a combination of automated constraints and human inspection in a three-dimensional virtual reality environment is used to select clouds that are exemplary in their behavior throughout their entire life span. Three specific cases (ARM, BOMEX, and BOMEX without large-scale forcings) are analyzed in this way, and the considerable number of selected clouds warrants reliable statistics of cloud properties conditioned on the phase in their life cycle. The most dominant feature in this statistical life cycle analysis is the pulsating growth that is present throughout the entire lifetime of the cloud, independent of the case and of the large-scale forcings. The pulses are a self-sustained phenomenon, driven by a balance between buoyancy and horizontal convergence of dry air. The convective inhibition just above the cloud base plays a crucial role as a barrier for the cloud to overcome in its infancy stage, and as a buffer region later on, ensuring a steady supply of buoyancy into the cloud.

No abstract available.

Figure 1: VR scenarios using the Wii Balance Board TM . From left to right: Our analysis environment to study incoming signals, 3D rotation in a desktop visualisation application, navigating a map in an personal VR station, controlling animation speed on a projection screen. AbstractWe demonstrate the use of the Wii Balance Board TM as a low-cost virtual reality input device. We provide an overview of obtaining and working with the sensor input. By processing the sensor values from the balance board, we are able to use it for both discrete and continuous input, which can be used to drive a variety of VR interaction metaphors. Using continuous input, the balance board is well suited for interactions requiring two simultaneous degrees of freedom and up to three total degrees of freedom, such as navigation or rotation. The discrete input is suitable for control input, such as mode switching or object selection.

In this paper we present an approach to coordinate the motions of droplets in digital microfluidic systems, a new class of lab-on-a-chip systems for biochemical analysis. A digital microfluidic system typically consists of a planar array of cells with electrodes that control the droplets. The primary challenge in using droplet-based systems is that they require the simultaneous coordination of a potentially large number of droplets on the array as the droplets move, mix, and split. In this paper we describe a general-purpose system that uses simple algorithms and yet is versatile. First, we present a semi-automated approach to generate the array layout in terms of components. Next, we discuss simple algorithms to select destination components for the droplets and a decentralized scheme for components to route the droplets on the array. These are then combined into a reconfigurable system that has been simulated in software to perform analyses such as the DNA polymerase chain reaction. The algorithms have been able to successfully coordinate hundreds of droplets simultaneously and perform one or more chemical analyses in parallel. Because it is challenging to analytically characterize the behavior of such systems, simulation methods to detect potential system instability are proposed.