Towards Our Common Digital Future. Flagship Report.

In the report “Towards Our Common Digital Future”, the WBGU makes it clear that sustainability strategies and concepts need to be fundamentally further developed in the age of digitalization. Only if digital change and the Transformation towards Sustainability are synchronized can we succeed in advancing climate and Earth-system protection and in making social progress in human development. Without formative political action, digital change will further accelerate resource and energy consumption, and exacerbate damage to the environment and the climate. It is therefore an urgent political task to create the conditions needed to place digitalization at the service of sustainable development

Contributions to on-board navigation on 1U CubeSats

This thesis investigates the use of GNSS receivers on 1U CubeSats, using the example of BEESAT-4 and BEESAT-9. The integration of such a device on satellites enables highly precise time synchronization, position acquisition and orbit determination and prediction The application fields that depend on an accurate attitude control and orbit determination system and can also be processed by CubeSats are highlighted. Therefore the state of the art of GNSS receivers is described, which are suitable for the use on satellites and could be integrated into 1U CubeSats. Further on it is investigated which subsystems of a small satellite are particularly affected and what the special challenges are to realize a precise positioning with a GNSS receiver. In addition, some developments are presented that have significantly increased the performance of 1U CubeSats in recent years. The system concept of BEESAT satellites is introduced and the evolution of the payload board including the use of the latest sensor technologies for attitude control is described. It is shown how the verification of the satellite's subsystems was performed on the ground, with the focus on testing and simulating the attitude control and the GNSS receiver. The necessary integration steps, the calibration and environmental test campaign are discussed. Both satellites were successfully operated and the results of the on-orbit experiments are presented. It is shown how a three-axis stabilized attitude control was first verified on BEESAT-4 and then a GNSS receiver was successfully operated on BEESAT-9 for more than one year. In addition, the inter-satellite link between BEESAT-4 and BIROS will be analyzed, since it is essential for the relative navigation of satellites. The acquired navigation data was sent to the ground and the identification of BEESAT-9 was carried out using this data. A qualitative analysis of the orbital elements (TLE) of BEESAT-9 was performed systematically due to a daily operation of the GNSS receiver. Furthermore, it was investigated how a small GNSS antenna affects the received signal strength from GNSS satellites and whether this antenna or its amplifier degrades over time. Additionally, an orbit determination and propagation based on the navigation data could be performed and the results are evaluated. The analyzed questions allow a statement about the continuous use of GNSS receivers on 1U CubeSats and if it is necessary to achieve the mission objectives

Visual Cortical Traveling Waves: From Spontaneous Spiking Populations to Stimulus-Evoked Models of Short-Term Prediction

Thanks to recent advances in neurotechnology, waves of activity sweeping across entire cortical regions are now routinely observed. Moreover, these waves have been found to impact neural responses as well as perception, and the responses themselves are found to be structured as traveling waves. How exactly do these waves arise? Do they confer any computational advantages? These traveling waves represent an opportunity for an expanded theory of neural computation, in which their dynamic local network activity may complement the moment-to-moment variability of our sensory experience. This thesis aims to help uncover the origin and role of traveling waves in the visual cortex through three Works. In Work 1, by simulating a network of conductance-based spiking neurons with realistically large network size and synaptic density, distance-dependent horizontal axonal time delays were found to be important for the widespread emergence of spontaneous traveling waves consistent with those in vivo. Furthermore, these waves were found to be a dynamic mechanism of gain modulation that may explain the in-vivo result of their modulation of perception. In Work 2, the Kuramoto oscillator model was formulated in the complex domain to study a network possessing distance-dependent time delays. Like in Work 1, these delays produced traveling waves, and the eigenspectrum of the complex-valued delayed matrix, containing a delay operator, provided an analytical explanation of them. In Work 3, the model from Work 2 was adapted into a recurrent neural network for the task of forecasting the frames of videos, with the question of how such a biologically constrained model may be useful in visual computation. We found that the wave activity emergent in this network was helpful, as they were tightly linked with high forecast performance, and shuffle controls revealed simultaneous abolishment of both the waves and performance. All together, these works shed light on the possible origins and uses of traveling waves in the visual cortex. In particular, time delays profoundly shape the spatiotemporal dynamics into traveling waves. This was confirmed numerically (Work 1) and analytically (Work 2). In Work 3, these waves were found to aid in the dynamic computation of visual forecasting

Virtual infrastructure for wireless ad hoc networks

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2007.Includes bibliographical references (v. 2, p. 585-591) and index.One of the most significant challenges introduced by ad hoc networks is coping with the unpredictable deployment, uncertain reliability, and erratic communication exhibited by emerging wireless networks and devices. The goal of this thesis is to develop a set of algorithms that address these challenges and simplify the design of algorithms for ad hoc networks. In the first part of this thesis, I introduce the idea of virtual infrastructure, an abstraction that provides reliable and predictable components in an unreliable and unpredictable environment. This part assumes reliable communication, focusing primarily on the problems created by unpredictable motion and fault-prone devices. I introduce several types of virtual infrastructure, and present new algorithms based on the replicated-state-machine paradigm to implement these infrastructural components. In the second part of this thesis, I focus on the problem of developing virtual infrastructure for more realistic networks, in particular coping with the problem of unreliable communication. I introduce a new framework for modeling wireless networks based on the ability to detect collisions. I then present a new algorithm for implementing replicated state machines in wireless networks, and show how to use replicated state machines to implement virtual infrastructure even in an environment with unreliable communication.by Seth Gilbert.Ph.D

The Impact of the Internationalisation of Higher Education on Scientists’ Multimodal Communication: A case study from Catalonia

Les universitats de tot el món són instades a participar en el procés d' ‘internacionalització’ com a distintiu de qualitat i com a reclam per atraure estudiants. Aquest estudi aborda aquesta qüestió des del context de les institucions catalanes d’educació superior, que afronten el dilema de donar suport a la/les llengua/gües local/s i, alhora, abraçar el multilingüisme i, sobretot, l’anglès. L'objectiu principal d'aquest estudi és examinar l'impacte de la internacionalització de l'educació superior en la comunicació diària dels científics. Les dades etnogràfiques s’han recopilat al llarg d’un període d’11 mesos d’observació de dos grups de recerca (RGs) multinacionals amb seu en una universitat catalana, i s’han contrastat amb dades extretes d’un RG amb seu a Alemanya i amb idees inspirades en les pràctiques del RG de la pròpia investigadora. De l'objectiu empíric n’ha derivat un objectiu teòric, que consisteix a dissenyar i provar un marc teòric adequat per estudiar el fenomen proposat de manera integral. Aquest estudi té l’objectiu de contribuir a la limitada literatura que descriu aquelles pràctiques comunicatives "informals" i inèdites dels científics, així com a la literatura sobre la internacionalització de l’ensenyament superior. A nivell pràctic, aquest treball pretén contribuir a la millora de les polítiques d’internacionalització de les institucions d’ensenyament superior de Catalunya, d’Europa i potencialment d’altres contextos arreu del món.Las universidades de todo el mundo son instadas a participar en el proceso de ‘internacionalización’ como distintivo de calidad y como reclamo para atraer estudiantes. Este estudio aborda esta cuestión desde el contexto de las instituciones catalanas de educación superior, que afrontan el dilema de apoyar la/s lengua/s local/es y, a la vez, abrazar el multilingüismo y, sobre todo, el inglés. El objetivo principal de este estudio es examinar el impacto de la internacionalización de la educación superior en la comunicación diaria de los científicos. Los datos etnográficos se han recopilado a lo largo de un período de 11 meses de observación de dos grupos de investigación (RGs) multinacionales con sede en una universidad catalana, y se han contrastado con datos extraídos de un RG con sede en Alemania y con ideas inspiradas en las prácticas del RG de la propia investigadora. Del objetivo empírico ha derivado un objetivo teórico, que consiste en diseñar y probar un marco teórico adecuado para estudiar el fenómeno propuesto de manera integral. Este estudio tiene el objetivo de contribuir a la limitada literatura que describe aquellas prácticas comunicativas "informales" e inéditas de los científicos, así como a la literatura sobre la internacionalización de la enseñanza superior. A nivel práctico, este trabajo pretende contribuir a la mejora de las políticas de internacionalización de las instituciones de enseñanza superior de Cataluña, de Europa y potencialmente de otros contextos en todo el mundo.Universities worldwide are urged to engage in the process of ‘internationalisation’ as a hallmark of quality and as a lure to attract students. The current study approaches this issue from the context of Catalan higher education institutions, which deal with the dilemma of supporting the local language(s) and at the same time embracing multilingualism and especially English. The main aim of this study is to examine the impact of the internationalisation of higher education on the daily communication of scientists. Ethnographic data have been collected throughout a period of 11 months from two multinational research groups (RGs) based in a Catalan state university, and contrasted with data taken from a RG based in Germany and with insights from the researcher’s own RG. From the empirical objective has derived a theoretical objective, consisting in designing and proving a suitable theoretical framework to study the phenomenon holistically. This study aims to contribute to the limited body of research describing scientists’ "informal" and unpublished communicative practices, as well as to the literature on the internationalisation of higher education. On a practical level, this work is intended to aid in the improvement of internationalisation policies of higher education institutions in Catalonia, in Europe and potentially in other contexts worldwide