Technische Universität Darmstadt

About: Technische Universität Darmstadt is a education organization based out in Darmstadt, Germany. It is known for research contribution in the topics: Computer science & Context (language use). The organization has 17316 authors who have published 40619 publications receiving 937916 citations. The organization is also known as: Darmstadt University of Technology & University of Darmstadt.

Assistance Magnitude Versus Metabolic Cost Reductions for a Tethered Multiarticular Soft Exosuit

Abstract: When defining requirements for any wearable robot for walking assistance, it is important to maximize the user's metabolic benefit resulting from the exosuit assistance while limiting the metabolic penalty of carrying the system's mass. Thus, the aim of this study was to isolate and characterize the relationship between assistance magnitude and the metabolic cost of walking while also examining changes to the wearer's underlying gait mechanics. The study was performed with a tethered multiarticular soft exosuit during normal walking, where assistance was directly applied at the ankle joint and indirectly at the hip due to a textile architecture. The exosuit controller was designed such that the delivered torque profile at the ankle joint approximated that of the biological torque during normal walking. Seven participants walked on a treadmill at 1.5 meters per second under one unpowered and four powered conditions, where the peak moment applied at the ankle joint was varied from about 10 to 38% of biological ankle moment (equivalent to an applied force of 18.7 to 75.0% of body weight). Results showed that, with increasing exosuit assistance, net metabolic rate continually decreased within the tested range. When maximum assistance was applied, the metabolic rate of walking was reduced by 22.83 ± 3.17% relative to the powered-off condition (mean ± SEM).

The SCIP Optimization Suite 7.0

Abstract: The SCIP Optimization Suite provides a collection of software packages for mathematical optimization centered around the constraint integer programming frame- work SCIP. This paper discusses enhancements and extensions contained in version 7.0 of the SCIP Optimization Suite. The new version features the parallel presolving library PaPILO as a new addition to the suite. PaPILO 1.0 simplifies mixed-integer linear op- timization problems and can be used stand-alone or integrated into SCIP via a presolver plugin. SCIP 7.0 provides additional support for decomposition algorithms. Besides im- provements in the Benders’ decomposition solver of SCIP, user-defined decomposition structures can be read, which are used by the automated Benders’ decomposition solver and two primal heuristics. Additionally, SCIP 7.0 comes with a tree size estimation that is used to predict the completion of the overall solving process and potentially trigger restarts. Moreover, substantial performance improvements of the MIP core were achieved by new developments in presolving, primal heuristics, branching rules, conflict analysis, and symmetry handling. Last, not least, the report presents updates to other components and extensions of the SCIP Optimization Suite, in particular, the LP solver SoPlex and the mixed-integer semidefinite programming solver SCIP-SDP.

Towards a Lie theory of locally convex groups

Abstract: In this survey, we report on the state of the art of some of the fundamental problems in the Lie theory of Lie groups modeled on locally convex spaces, such as integrability of Lie algebras, integrability of Lie subalgebras to Lie subgroups, and integrability of Lie algebra extensions to Lie group extensions. We further describe how regularity or local exponentiality of a Lie group can be used to obtain quite satisfactory answers to some of the fundamental problems. These results are illustrated by specialization to some specific classes of Lie groups, such as direct limit groups, linear Lie groups, groups of smooth maps and groups of diffeomorphisms.

Function of Nicotiana tabacum Aquaporins as Chloroplast Gas Pores Challenges the Concept of Membrane CO2 Permeability

Abstract: Photosynthesis is often limited by the rate of CO2 diffusion from the atmosphere to the chloroplast. The primary resistances for CO2 diffusion are thought to be at the stomata and at photosynthesizing cells via a combination resulting from resistances of aqueous solution as well as the plasma membrane and both outer and inner chloroplast membranes. In contrast with stomatal resistance, the resistance of biological membranes to gas transport is not widely recognized as a limiting factor for metabolic function. We show that the tobacco (Nicotiana tabacum) plasma membrane and inner chloroplast membranes contain the aquaporin Nt AQP1. RNA interference–mediated decreases in Nt AQP1 expression lowered the CO2 permeability of the inner chloroplast membrane. In vivo data show that the reduced amount of Nt AQP1 caused a 20% change in CO2 conductance within leaves. Our discovery of CO2 aquaporin function in the chloroplast membrane opens new opportunities for mechanistic examination of leaf internal CO2 conductance regulation.

If and Then: A Critique of Speculative NanoEthics

Abstract: Most known technology serves to ingeniously adapt the world to the physical and mental limitations of human beings. Humankind has acquired awesome power with its rather limited means. Nanotechnological capabilities further this power. On some accounts, however, nanotechnological research will contribute to a rather different kind of technological development, namely one that changes human beings so as to remove or reduce their physical and mental limitations. The prospect of this technological development has inspired a fair amount of ethical debate. Here, proponents and opponents of such visions of human enhancement are criticized alike for engaging in speculative ethics. This critique exposes a general pattern that extends to other nano-, bio-, or neuroethical debates. While it does not apply to all discussions of “enhancement technologies” it does apply to all ethical discourse that constructs and validates an incredible future which it only then proceeds to endorse or critique. This discourse violates conditions of intelligibility, squanders the scarce and valuable resource of ethical concern, and misleads by casting remote possibilities or philosophical thought-experiments as foresight about likely technical developments. In effect, it deflects consideration from the transformative technologies of the present.