Capability Development in Interorganizational Projects

We examine how capabilities emerge in repeated interorganizational projects and how they affect project development. A multifaceted understanding of project capabilities in interorganizational projects is important, because project management research emphasizes capabilities’ contribution to project performance, but has also stressed their tendency to grow rigid. We review the literature on interorganizational project collaboration to identify the foundations and drivers of project capabilities in project networks and to outline their potentially ambiguous consequences. Our systematic overview of these studies provides a basis for further empirical research and project management practice

A Realistic Radar Ray Tracing Simulator for Hand Pose Imaging

With the increasing popularity of human-computer interaction applications, there is also growing interest in generating sufficiently large and diverse data sets for automatic radar-based recognition of hand poses and gestures. Radar simulations are a vital approach to generating training data (e.g., for machine learning). Therefore, this work applies a ray tracing method to radar imaging of the hand. The performance of the proposed simulation approach is verified by a comparison of simulation and measurement data based on an imaging radar with a high lateral resolution. In addition, the surface material model incorporated into the ray tracer is highlighted in more detail and parameterized for radar hand imaging. Measurements and simulations show a very high similarity between synthetic and real radar image captures. The presented results demonstrate that it is possible to generate very realistic simulations of radar measurement data even for complex radar hand pose imaging systems.Comment: 4 pages, 5 figures, accepted at European Microwave Week (EuMW 2023) to the topic "R28 Human Activity Monitoring, including Gesture Recognition

Achieving Efficient and Realistic Full-Radar Simulations and Automatic Data Annotation by exploiting Ray Meta Data of a Radar Ray Tracing Simulator

In this work a novel radar simulation concept is introduced that allows to simulate realistic radar data for Range, Doppler, and for arbitrary antenna positions in an efficient way. Further, it makes it possible to automatically annotate the simulated radar signal by allowing to decompose it into different parts. This approach allows not only almost perfect annotations possible, but also allows the annotation of exotic effects, such as multi-path effects or to label signal parts originating from different parts of an object. This is possible by adapting the computation process of a Monte Carlo shooting and bouncing rays (SBR) simulator. By considering the hits of each simulated ray, various meta data can be stored such as hit position, mesh pointer, object IDs, and many more. This collected meta data can then be utilized to predict the change of path lengths introduced by object motion to obtain Doppler information or to apply specific ray filter rules in order obtain radar signals that only fulfil specific conditions, such as multiple bounces or containing specific object IDs. Using this approach, perfect and otherwise almost impossible annotations schemes can be realized.Comment: Accepted for IEEE RadarConf 202

Concept for an Automatic Annotation of Automotive Radar Data Using AI-segmented Aerial Camera Images

This paper presents an approach to automatically annotate automotive radar data with AI-segmented aerial camera images. For this, the images of an unmanned aerial vehicle (UAV) above a radar vehicle are panoptically segmented and mapped in the ground plane onto the radar images. The detected instances and segments in the camera image can then be applied directly as labels for the radar data. Owing to the advantageous bird's eye position, the UAV camera does not suffer from optical occlusion and is capable of creating annotations within the complete field of view of the radar. The effectiveness and scalability are demonstrated in measurements, where 589 pedestrians in the radar data were automatically labeled within 2 minutes.Comment: 6 pages, 5 figures, accepted at IEEE International Radar Conference 2023 to the Special Session "Automotive Radar

Überwachung der kontinuierlichen hydrothermalen Synthese mittels Impedanzspektroskopie

Die kontinuierliche hydrothermale Synthese (CHTS) stellt ein vielversprechendes Verfahren zur Herstellung metalloxidischer Nanopartikel dar. Das Prinzip beruht auf der Vermischung einer kalten wässrigen Metallsalzlösung mit einem nahe-/überkritischen Wasserstrom. Durch die außergewöhnlichen Eigenschaften des überkritischen Wassers kommt es zur Partikelbildung. Neben der Studie des Einflusses der Prozessparameter auf die resultierende Partikelgröße und -verteilung ist die Restkonzentration an gelöstem Metallsalz von Interesse. Diese kann mittels der Impedanzspektroskopie analysiert werden. Dazu werden an einer modifizierten CHTS-Anlage Vorversuche durchgeführt, um zukünftig die Restkonzentration direkt bestimmen zu können

Numerical Optimization of an Open-Ended Coaxial Slot Applicator for the Detection and Microwave Ablation of Tumors

A multiobjective optimization method for a dual-mode microwave applicator is proposed. Dual-modality means that microwaves are used apart from the treatment, and also for the monitoring of the microwave ablation intervention. (1) The use of computational models to develop and improve microwave ablation applicator geometries is essential for further advances in this field. (2) Numerical electromagnetic–thermal coupled simulation models are used to analyze the performance of the dual-mode applicator in liver tissue; the sensitivity evaluation of the dual-mode applicator’s sensing mode constrains the set of optimal solutions. (3) Three Pareto-optimal design parameter sets are derived that are optimal in terms of applicator efficiency as well as volume and sphericity of the ablation zone. The resulting designs of the dual-mode applicator provide a suitable sensitivity to distinguish between healthy and tumorous liver tissue. (4) The optimized designs are presented and numerically characterized. An improvement on the performance of previously proposed dual-mode applicator designs is achieved. The multiphysical simulation model of electromagnetic and thermal properties of the applicator is applicable for future comprehensive design procedures

Gradient-Index-Based Frequency-Coded Retroreflective Lenses for mm-Wave Indoor Localization

This article introduces retroreflective lenses for millimeter-wave radio-frequency indoor localization. A three-dimensional (3D) gradient-index Luneburg lens is employed to increase radar cross section (RCS) of photonic-crystal high-Q resonators and its performance is compared to conventional radar retroreflectors. A classic Luneburg lens with and without a reflective layer is realized with 25 mm diameter (6.7 lambda(0)), showing a realized gain of 24.6 dBi and a maximum RCS of -9.22 dBm(2) at 80 GHz. The proposed Luneburg lens with embedded high-Q resonators as frequency-coded particles in a photonic crystal structure, operating as a reflective layer, achieved a maximum RCS of -15.84 dBm(2) at the resonant frequency of 76.5 GHz and showed a repeatable response each 18 degrees over +/- 36 degrees in two perpendicular planes. With this high RCS of the Luneburg lens, a maximum readout range of 1.3 m could be achieved compared to 0.15 m without the lens at 76.5 GHz for the same transmit power, receiver sensitivity, and gain of the reader antenna

Robust Magnetic Order Upon Ultrafast Excitation of an Antiferromagnet

The ultrafast manipulation of magnetic order due to optical excitation is governed by the intricate flow of energy and momentum between the electron, lattice, and spin subsystems. While various models are commonly employed to describe these dynamics, a prominent example being the microscopic three temperature model (M3TM), systematic, quantitative comparisons to both the dynamics of energy flow and magnetic order are scarce. Here, an M3TM was applied to the ultrafast magnetic order dynamics of the layered antiferromagnet GdRh2Si2. The femtosecond dynamics of electronic temperature, surface ferromagnetic order, and bulk antiferromagnetic order were explored at various pump fluences employing time- and angle-resolved photoemission spectroscopy and time-resolved resonant magnetic soft X-ray diffraction, respectively. After optical excitation, both the surface ferromagnetic order and the bulk antiferromagnetic order dynamics exhibit two-step demagnetization behaviors with two similar timescales (<1 ps, ∼10 ps), indicating a strong exchange coupling between localized 4f and itinerant conduction electrons. Despite a good qualitative agreement, the M3TM predicts larger demagnetization than the experimental observation, which can be phenomenologically described by a transient, fluence-dependent increased Néel temperature. The results indicate that effects beyond a mean-field description have to be considered for a quantitative description of ultrafast magnetic order dynamics

Wide-Angle Ceramic Retroreflective Luneburg Lens Based on Quasi-Conformal Transformation Optics for Mm-Wave Indoor Localization

This paper presents a quasi-conformal transformation optics (QCTO) based three-dimensional (3D) retroreflective attened Luneburg lens for wide-angle millimeter-wave radio-frequency indoor localization. The maximum detection angle and radar cross-section (RCS) are investigated, including an impedance matching layer (IML) between the lens antenna and the free-space environment. The 3D QCTO Luneburg lenses are fabricated in alumina by lithography-based ceramic manufacturing, a 3D printing process. The manufactured structures have a diameter of 29.9 mm (4 lambda_0), showing a maximum realized gain of 16.51 dBi and beam steering angle of +-70° at 40 GHz. The proposed QCTO Luneburg lens with a metallic reflective layer achieves a maximum RCS of -20.05 dBsqm at 40 GHz with a wide-angle response over +-37°, while the structure with an IML between the lens and air improves these values to a maximum RCS of -15.78 dBsqm and operating angular response between +-50°