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Evapotranspiration (ET) is a crucial component of urban water and energy regimes, yet our understanding of the role of vegetation in the urban water cycle is still poor. In order to assess the diurnal and seasonal variability of ET from urban vegetation types, an interdisciplinary sampling campaign integrating remote sensing and field-based methods is currently underway at a study site in Berlin, Germany. The sampling is being conducted from spring to winter 2019 in order to characterize the seasonality in hydroclimatic drivers and phenological effects on ET. Three main vegetation types (urban grassland, trees, and shrubs) are sampled. Drone flights with multispectral and thermal cameras are being undertaken. Leaf Area Index and soil moisture are being measured, at monthly and 15-minute resolution, respectively. Using LI-6800, the diurnal and seasonal variation of gas exchange and stomatal conductance is being measured. ET estimates from drone data will be derived using algorithms, such as the “Triangle Method” [1] and 3T model [2] and validated with field-based ET estimates. Eddy flux data will be analyzed to validate modelled ET and provide hydroclimatic data. Sap flow monitoring will quantify tree transpiration. In the first stage of this study, a time series of ET across seasonal and diurnal scales of a single year will be generated for the local study area. Then, the field-validated UAV data will be combined with satellite data to upscale ET spatially and temporally to provide multi-year estimates of ET for the entire urban area (Berlin). This study will provide an enhanced understanding of the spatio-temporal variability of ET of urban vegetation, which will be essential for urban planning in the context of climate change.

Ultrasound (US) guidance is a rapidly growing area in image-guided radiotherapy. For motion compensation, the therapy target needs to be visualized with the US probe to continuously determine its position and adapt for shifts. While US has obvious benefits such as real-time capability and proven safety, one of the main drawbacks to date is its user dependency - high quality results require long years of clinical experience. To provide positioning assistance for the setup of US equipment by non-experts, we developed a visual guidance tool combining real-time US volume and CT visualization in a geometrically calibrated setup. By using a 4D US station with real-time data access and an optical tracking system, we achieved a calibration accuracy of 1.2 mm and a mean 2D contour distance of 1.7 mm between organ boundaries identified in US and CT. With this low calibration error as well as the good visual alignment of the structures, the developed probe positioning tool could be a valuable aid for ultrasound-guided radiotherapy and other interventions by guiding the user to a suitable acoustic window while potentially improving setup reproducibility.

This paper presents a detailed dexterity analysis of three different kinematics, comparing six-DoF with seven-DoF robots. The KUKA LBR iiwa 7 lightweight robot represents the seven-DoF kinematics, while the KUKA KR 10 is chosen as a common six-DoF robot with comparable workspace dimensions. Furthermore, the LBR iiwa is simulated as a six-jointed robot to allow for a direct comparison of seven- and six-DoF kinematics. Due to this simulation it is possible to isolate the effects of the additional 7th DoF for the first time. The results show that the average dexterity is increased by 16.8% due to the additional 7th joint. Compared to the highest average dexterity of the seven-DoF manipulator, the six-DoF KR 10 outperforms this value by 7.6%.

This paper presents an optimized, robust inverse kinematics solution in a closed form for redundant manipulators with seven degrees of freedom and zero link offsets like the KUKA LBR iiwa lightweight robot. The computation allows for full range elbow self-motion manifold control, defined by an intuitive angle parameter. Furthermore, by using common configuration parameters, all possible solutions for a single effector pose are taken into account and full arm configuration control is realized. The algorithm was evaluated looking at configuration reliability and continuity for an exemplary, challenging path. The results show that commanded arm configurations are not changing spontaneously inside a trajectory. Even for varying elbow self-motion manifold angles, the joint trajectories stay continuous and the presented algorithm provides consistent solutions. In a second evaluation, the algorithm was implemented in three programming languages and analyzed with respect to computing times. The tests demonstrate short runtimes and overall real-time capability.

This paper presents a method to solve - in real time - the three dimensional workspace generation problem for arbitrary serial manipulators. Our approach is based on Monte Carlo simulation, to process a high number of forward kinematics with randomly chosen joint values. This results in an asymptotic coverage of the reachable workspace. Additionally, collision detection is integrated to consider obstacles within the manipulator's environment. The method is implemented on the graphics processing unit (GPU), such that an extremely high number of workspace points can be processed in parallel. Tests have shown that this approach is capable to generate acceptable workspace coverage within milliseconds. Furthermore, the workspace is held as a three dimensional texture volume on the graphics memory, allowing for instant visualisation of the workspace during the generation process without the need for further time-intensive data exchange.

Software product line engineering aims at the efficient development of program variants that share a common set of features and that differ in other features. Product lines can be efficiently developed using feature-oriented programming. Given a feature selection and the code artifacts for each feature, program variants can be generated automatically. The quality of the program variants can be rigorously ensured by formal verification. However, verification of all program variants can be expensive and include redundant verification tasks. We introduce a classification of existing software product line verification approaches and propose proof composition as a novel approach. Proof composition generates correctness proofs of each program variant based on partial proofs of each feature. We present a case study to evaluate proof composition and demonstrate that it reduces the effort for verification.

A software product line (SPL) enables stakeholders to derive different software products for a domain while providing a high degree of reuse of their code units. Software products are derived in a configuration process by composing different code units. The configuration process becomes complex if SPLs contain hundreds of features. In many cases, a stakeholder is not only interested in functional but also in non-functional properties of a desired product. Because SPLs can be used in different application scenarios alternative implementations of already existing functionality are developed to meet special non-functional requirements, like restricted binary size and performance guarantees. To enable these complex configurations we discuss and present techniques to measure non-functional properties of software modules and use these values to compute SPL configurations optimized to the users needs.

We report on measurements of the average surface resistance of structured thin Y1Ba2Cu307-films between 0.7 and 3 GHz. The films are structured as a meanderline resonator. The coupling of neighboured lines is taken into consideration. The structured film is put together with two superconducting ground planes to an inverted microstrip structure. The quality factor of the resonator is measured. A comparison between the measurement and a calculation then connects the quality factor to the average surface resistance of the thin HTc film and the loss factor of the substrates. We obtained results for films of different quality. The best films on LaAlO3 showed average surface resistance values down to 0.06 m? at 77 K and only a weak dependence on the applied input power at low power levels.