Mathematical Modeling, Motion Planning and Control of Elastic Structures with Piezoelectric Elements

The objective of this work is the development of a motion planning and tracking control approach for elastic structures. Motivated by the morphing wing concept of the field of aerospace engineering a so-called “smart wingsail” defines the center of the presented research. The motion planning and tracking control approach has to achieve different rest-to-rest motions of the wingsail’s transversal displacement. The design of the mechanical structure as well as the control concept of the wingsail relies on the results of proof of concept studies. For this purpose, different systems of interconnected bending beams are considered which emulates parts of the wingsail. The development of the model based control approaches requires an accurate system description. The modeling itself is done by an analytic energy based approach for the beams’ systems, where for the wingsail the finite elements method is used due to the risen complexity of the curved structure. To achieve a precise description of the governing dynamics different parameter identification concepts are discussed and applied. This leads to a precise but rather complex system description which covers the measured behavior of the experimental setups. Considering the objective of a real time capable control approach the complexity has to be reduced without a significant loss of accuracy. For this purpose different model order reduction techniques are discussed and applied. The resulting systems models are the bases of the control designs. Two different control concepts are presented and evaluated. At first the two-degrees-of-freedom control approach is introduced which combines a flatness-based feedforward control approach with a feedback controller. On the other hand, the so-called model predictive control approach is presented which is based on the solution of an optimization problem. Both concepts are evaluated by numeric analyses and by experiments

COVID-19 severity and mortality in patients with CLL: an update of the international ERIC and Campus CLL study

Patients with chronic lymphocytic leukemia (CLL) may be more susceptible to Coronavirus disease 2019 (COVID-19) due to age, disease, and treatment-related immunosuppression. We aimed to assess risk factors of outcome and elucidate the impact of CLL-directed treatments on the course of COVID-19. We conducted a retrospective, international study, collectively including 941 patients with CLL and confirmed COVID-19. Data from the beginning of the pandemic until March 16, 2021, were collected from 91 centers. The risk factors of case fatality rate (CFR), disease severity, and overall survival (OS) were investigated. OS analysis was restricted to patients with severe COVID-19 (definition: hospitalization with need of oxygen or admission into an intensive care unit). CFR in patients with severe COVID-19 was 38.4%. OS was inferior for patients in all treatment categories compared to untreated (p < 0.001). Untreated patients had a lower risk of death (HR = 0.54, 95% CI:0.41–0.72). The risk of death was higher for older patients and those suffering from cardiac failure (HR = 1.03, 95% CI:1.02–1.04; HR = 1.79, 95% CI:1.04–3.07, respectively). Age, CLL-directed treatment, and cardiac failure were significant risk factors of OS. Untreated patients had a better chance of survival than those on treatment or recently treated

The evolving landscape of COVID‐19 and post‐COVID condition in patients with chronic lymphocytic leukemia: A study by ERIC, the European research initiative on CLL

In this retrospective international multicenter study, we describe the clinical characteristics and outcomes of patients with chronic lymphocytic leukemia (CLL) and related disorders (small lymphocytic lymphoma and high-count monoclonal B lymphocytosis) infected by SARS-CoV-2, including the development of post-COVID condition. Data from 1540 patients with CLL infected by SARS-CoV-2 from January 2020 to May 2022 were included in the analysis and assigned to four phases based on cases disposition and SARS-CoV-2 variants emergence. Post-COVID condition was defined according to the WHO criteria. Patients infected during the most recent phases of the pandemic, though carrying a higher comorbidity burden, were less often hospitalized, rarely needed intensive care unit admission, or died compared to patients infected during the initial phases. The 4-month overall survival (OS) improved through the phases, from 68% to 83%, p = .0015. Age, comorbidity, CLL-directed treatment, but not vaccination status, emerged as risk factors for mortality. Among survivors, 6.65% patients had a reinfection, usually milder than the initial one, and 16.5% developed post-COVID condition. The latter was characterized by fatigue, dyspnea, lasting cough, and impaired concentration. Infection severity was the only risk factor for developing post-COVID. The median time to resolution of the post-COVID condition was 4.7 months. OS in patients with CLL improved during the different phases of the pandemic, likely due to the improvement of prophylactic and therapeutic measures against SARS-CoV-2 as well as the emergence of milder variants. However, mortality remained relevant and a significant number of patients developed post-COVID conditions, warranting further investigations

Increasing User Engagement in Re-designed Classic Video Games

The development of low cost 3D visualization devices has prompted an increased interest in interactive Virtual Reality (VR) applications. A key factor in the design and implementation of VR applications is the immersion level that indicates the quality of user experience and level of engagement. In an attempt to enhance the user engagement in VR computer games we explore two distinct directions which include (i) The use of statistical 3D shape modeling and dedicated image processing techniques that enable the generation and subsequent use of personalized avatars in collaborative VR environments and (ii) The adaptation of retro video games to multiuser VR environments. The ultimate aim of our work is to combine the results of the two approaches so users are offered the ability to use their personal avatars in VR classic game environments so that the level of immersion and user satisfaction is maximized

Artificial Fishtail Mesh

Tetrahedron mesh for the artificial Fishtail described in Modeling and Motion Planning for an Artificial Fishtail. The Mesh has been created with Trelis. The file meas_pos.csv contains some virtual measurement positions

Presenting cypriot cultural heritage in virtual reality: A user evaluation

This paper presents a user evaluation related to the overall experience of a number of volunteers obtained by visiting two virtual museums populated with digitized Cypriot cultural heritage/art items using different virtual reality display systems. The two virtual museums used are replicas of an engraving museum and a virtual Byzantine icons museum. During the experiment visitors were able to use a Head Mounted Display or a stereoscopic Powerwall projection in order to obtain an immersive 3D experience. The results of the user evaluation indicate that both ways of presenting the museum received an equal usability score among the users but at the same time a number of drawbacks of each method were indicated. The findings of the research are crucial in enabling the use of a user-centered design process approach to improve the prototypes and develop virtual experiences for additional museums. The ultimate aim of our approach is to develop applications that showcase Cypriot Cultural Heritage in a way that attracts visitors to visit the original museums

Wenn die Schlaffee schlecht zaubert – eine kritische Analyse der Kinderbücher zum Thema Schlafen

Schlarb A, Landwehr J, Kater M-J, et al. Wenn die Schlaffee schlecht zaubert – eine kritische Analyse der Kinderbücher zum Thema Schlafen. Somnologie. 2020;24(4):229-236.#### Hintergrund Schlafkinderbücher gibt es sehr viele. Sie gehören meist zu den Zu-Bett-geh-Ritualen. Die alters- sowie schlafbezogene Adäquatheit und Gestaltung ist jedoch noch nicht erforscht worden. #### Methode In einer umfangreichen Literaturrecherche wurden altersspezifische Kinderbücher eruiert und nach theoriegeleiteten Kriterien (Sprache, Thematik, Schlafhygiene, Lösungsansätze, Übungen, Bildgestaltung) von unterschiedlichen Gutachter*innen nach einem Schulungsprozess bewertet. #### Ergebnisse Es wurden 608 Kinderbücher für die Altersspanne 0 bis 12 Jahre gefunden; 64 Bücher für Kinder ab dem Alter von 0 oder 1 Jahr, 289 Bücher ab 2 bis 3 Jahren, 128 Bücher ab 4 Jahren und 13 Bücher für ältere Kinder ab 6 Jahren. Vor allem die schlafspezifischen Aspekte und Hintergründe sowie Lösungsstrategien für mögliche Schlafprobleme werden häufig recht unzureichend oder gar falsch beschrieben. #### Diskussion Obwohl es viele Kinderbücher mit Schlafthematik gibt, sind doch viele nicht kompetent hinsichtlich des Themas Schlaf gestaltet worden. Dies sollte bei der Auswahl und Empfehlung beachtet werden. Die Möglichkeit durch Kinderbücher präventiv wirksame Methoden für Familien zu gestalten wird somit nicht ausreichend genutzt