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Mechanical behaviour of glassy polymers: experiments and modelling

This thesis presents experimental investigation and modelling of the mechanical response of glassy polycarbonate (PC) during deformation. The mechanical response is studied experimentally over a wide range of length-scales using X-ray scattering techniques and optical full-field deformation measurement by Digital Image Correlation (DIC). Results from the experimental work have been used to develop

A Framework for Nonlinear Model Predictive Control in JModelica.org

Nonlinear Model Predictive Control (NMPC) is a control strategy based on repeatedly solving an optimal control problem. In this paper we present a new MPC framework for the JModelica.org platform, developed specifically for use in NMPC schemes. The new framework utilizes the fact that the optimal control problem to be solved does not change between solutions, thus decreasing the computation time n

A Review of Public Policies Relating to the Use of Environmental Labelling and Information Schemes (ELIS)

This report provides a brief review of how national government policies and guidelines apply to or regulate the use of environmental labelling and information schemes (ELIS) in selected OECD countries. The report reviews definitions relevant to environmental claims and identifies four types of potentially false or misleading environmental claims. The report also reviews countries’ different approa

Hierarchical Predictive Control for Ground-Vehicle Maneuvering

This paper presents a hierarchical approach to feedback-based trajectory generation for improved vehicle autonomy. Hierarchical vehicle-control structures have been used before—for example, in electronic stability control systems, where a low-level control loop tracks high-level references. Here, the control structure includes a nonlinear vehicle model already at the high level to generate optimiz

Grey-Box Building Models for Model Order Reduction and Control

As automatic sensing and Information and Communication Technology (ICT) get cheaper, building monitoring data is easier to obtain. The abundance of data leads to new opportunities in the context of energy efficiency in buildings. This paper describes ongoing developments and first results of data-driven grey-box modelling for buildings. A Python toolbox is developed based on a Modelica library wit

Symbolic Transformations of Dynamic Optimization Problems

Dynamic optimization problems involving differential-algebraic equation (DAE) systems are traditionally solved while retaining the semi-explicit or implicit form of the DAE. We instead consider symbolically transforming the DAE into an ordinary differential equation (ODE) before solving the optimization problem using a collocation method. We present a method for achieving this, which handles DAE-c

Collocation Methods for Optimization in a Modelica Environment

The solution of generic dynamic optimization problems described by Modelica, and its extension Optimica, code using direct collocation methods is discussed. We start by providing a description of dynamic optimization problems in general and how to solve them by means of direct collocation. Next, an existing implementation of a collocation algorithm in JModelica.org, using CasADi and IPOPT, is pres

Dynamic Parametric Sensitivity Optimization Using Simultaneous Discretization in JModelica.org

Dynamic optimization problems involving parametric sensitivities, such as optimal experimental design, are typically solved using shooting-based methods, while leveraging numerical integrators with sensitivity computation capabilities. In this paper we present how simultaneous discretization can be employed to solve these problems, by augmenting the dynamic optimization problems with forward sensi

Discrepancies between cortical and behavioural long-term readouts of hyperalgesia in awake freely moving rats

BACKGROUND: It is still unclear to what extent the most common animal models of pain and analgesia, based on indirect measures such as nocifensive behaviours, provide valid measures of pain perception.METHODS: To address this issue, we developed a novel animal model comprising a more direct readout via chronically (>1 month) implanted multichannel electrodes (MCE) in rat primary somatosensory cort

Embedded Ultrathin Cluster Electrodes for Long-Term Recordings in Deep Brain Centers

Neural interfaces which allow long-term recordings in deep brain structures in awake freely moving animals have the potential of becoming highly valuable tools in neuroscience. However, the recording quality usually deteriorates over time, probably at least partly due to tissue reactions caused by injuries during implantation, and subsequently micro-forces due to a lack of mechanical compliance be