117 research outputs found
Why life speeds up as you get older how memory shapes our past
No full text"In this book, Douwe Draaisma, author of the internationally acclaimed Metaphors of Memory, explores the nature of autobiographical memory. Applying a unique blend of scholarship, poetic sensibility and keen observation he tackles such extraordinary phenomena as deja vu, near-death experiences, the memory feats of idiots savants and the effects of extreme trauma on memory recall. Raising almost as many questions as it answers, this book will not fail to touch you at the same time as it educates and entertains."--BOOK JACKET
The effects of fire and grazing on the energy reserves of resprouting plants in Victoria's alpine grasslands
Full text linkDeposited with permission of the author. © 2002 Dr. Arn Douwe TolsmaSince European settlement, alpine and sub-alpine grasslands in Victoria have been grazed more intensively and wildfires have become more frequent. Alpine plants, however, have primarily evolved in the absence of fire and grazing, suggesting that they might be particularly sensitive to these factors. Little is known about the short-term physiological responses to defoliation of these predominantly resprouting plants, and this thesis investigates changes in the carbohydrate storage reserves of alpine plants during recovery from fire and/or grazing. (For complete abstract open document
Forgetting myths, perils and compensations
No full text"In his highly praised book The Nostalgia Factory, renowned memory scholar Douwe Draaisma explored the puzzling logic of memory in later life with humor and deep insight. In this compelling new book he turns to the "miracle" of forgetting. Far from being a defect that may indicate Alzheimer's or another form of dementia, Draaisma claims, forgetting is one of memory's crucial capacities. In fact, forgetting is essential. Weaving together an engaging array of literary, historical, and scientific sources, the author considers forgetting from every angle. He pierces false cliches and asks important questions: Is a forgotten memory lost forever? What makes a colleague remember an idea but forget that it was yours? Draaisma explores "first memories" of young children, how experiences are translated into memory, the controversies over repression and "recovered" memories, and weird examples of memory dysfunction. He movingly examines the impact on personal memories when a hidden truth comes to light. In a persuasive conclusion the author advocates the undervalued practice of "the art of forgetting"--a set of techniques that assist in erasing memories, thereby preserving valuable relationships and encouraging personal contentment"-
Servitization of Security Entrances
No full textServitization. It can be seen in all branches and it seems as if every company is shifting towards a business model where they do not only sell products, but offer service, financing and advice. The security branche is no different. With companies wanting to focus on their core business they do not longer want to buy security cameras, locks and gates. Their real need: the ability to work and store on a secure location. Part of this is having a secure entrance that fits with their needs. Boon Edam is a company that claims to be: ‘your entry expert’. Following the servitization trend they want to invest in a service for their clients and create a competitive advantage in the market. The goal of this thesis is to create a strategy for Boon Edam that creates this competitive advantage in the market. This strategy is based on a model for finding opportunities for security services, as designed by the author. This model is iterated several times during the thesis as more information is found from practice. The author uses customer driven design to create a service that fits with the demands and needs of Boon Edams client. First a research is conducted to provide a starting point for the graduation project. This also provides a general understanding in different aspects related to Boon Edam and security entrances, as well as a first view on requirements for the design. The research consists of various methods to understand and visualize the position of different stakeholders. After this, six stakeholders of Boon Edam are interviewed to provide qualitative insights in the customer needs. This results in reviewed thoughts on assumptions made in the research phase, as well as a framework for the design of the service. Using the framework and the information of the interviews a service is proposed which should provide Boon Edam with the competitive advantage. The service focusses on improving the customer relationship by offering them more support in their decision making and evaluating and improving their entrance solution. According to Baines et al. (2017) this can be seen as advanced services, which should lead to: - Growth in revenue and profit - Improved responses to customer needs - Improved product innovation - The building of new revenue streams - Increasing customer loyalty - Setting higher barriers to competition After the design of the proposed service is explained an implementation plan is written for Boon Edam to adopt the service within their portfolio. With this implementation plan it should be possible to have the service fully implemented at the end of 2019 latest
Developing a User Experience and Design System for WhereTrip.com
No full textA user experience and design system are developed from scratch for a small tech start-up, this report describes the steps and methods that are used as well as the end result.Design for Interactio
Modelling compressive membrane action and geometrical nonlinearity in one way concrete slabs
No full textIncreased traffic loads and ageing of concrete bridges and overpasses in the Netherlands make it necessary to reassess these existing structures. Consequently, the current condition and capacity of many concrete structures need to be evaluated. Residual capacity could be discovered during reassessments of concrete slabs due to a phenomenon called compressive membrane action (CMA). CMA is the formation of internal compressive arches caused by the lateral restraint. As a result, the load is not only transferred by bending action but also by arching action. Research has shown that the ultimate capacity can be significantly increased due to the occurrence of CMA. The goal of this study is to examine the influence of geometrical nonlinearity on this increase in capacity. Also, accurate quantification of the capacity enhancement for a variety of concrete slab variants can be scientifically useful and increases the knowledge on CMA. The study is confined to one way reinforced and restrained concrete slabs.A new analytical model is presented to quantify the capacity enhancement due to CMA and the geometrical nonlinear (GNL) effect on the capacity. Calibration of the analytical model is performed with a finite element model in DIANA FEA. Also, the finite element model validates the analytical results and is used to study the failure mode of a restrained concrete slab in detail. The enhancement factor – defined as the enhanced capacity divided by the conventional capacity – turned out to be varying between 1.35 and 4.7 for a large variety of restrained concrete slabs. Thus, the ultimate capacity of restrained one way slabs is significantly increased due to CMA. However, the capacity enhancement would have been even greater if geometrical nonlinearity was not accounted for. Geometrical nonlinearity reduces the increase in capacity because the formed compressive arches will tilt as a result of deflections, therefore leading to a relative decrease of the resisting arching moments. This GNL reduction effect varies between 3% and 37% according to the finite element model. The calibrated analytical model sufficiently estimates this effect with a maximum deviation of about 12%. An important finding was that the enhancement factor is larger for deep slabs than for slender slabs, while the reduction of the ultimate load due to geometrical nonlinearity is larger for slender slabs than for deep slabs. Civil Engineering | Structural Engineering | Concrete Structure
Labour shortage in the Netherlands after 2021
No full textThis thesis investigates the unprecedented labour market tension in the Netherlands post-2021, by analyzing the core drivers behind the labour market. A framework based on labour demand and supply is made in order to study the key drivers of the labour market. Through quantitative analysis it is found that the labour market tension after 2021 is primarily caused by a surge in the demand for labour, which in turn is likely to be caused by four key factors, government spending, more expenditure due to COVID-19 savings, exogenous investments in some sectors and increased net exports. It is advised to policy makers to focus more on tempering the demand for labour, if they desire to loosen up the labour market.Management of Technology (MoT
Reinforcement bipolar read: addressing read disturb in RRAM
No full textMemory advances have not kept up with computing demands. Emerging device technology Resistive RAM (RRAM) addresses this by enabling computation-in-memory. However, RRAM suffers from read disturb, limiting viability. While earlier work has had some success in reducing read disturb by switching the read current direction (a bipolar read scheme), the RRAM device eventually degraded. In this work, a reinforcing bipolar read scheme is introduced, which aims to prevent read disturb by reinforcing both HRS and LRS, away from the undefined state. From device-level simulation, this reinforcing behaviour is predicted for V = 0.5, 0.4 and 0.3 V with a fixed switching ratio between time under positive and negative read voltage polarity rsw i tch = 2.5, 2.5 and 2.75, respectively. At V = 0.2 V and V = 0.1 V, it is predicted that no reinforcement scheme exists. The bipolar read scheme found for V = 0.5 V was evaluated in circuit simulation with a sense amplifier. however the HRS and LRS reinforcing behaviour found at device-level could not be replicated. From unipolar read results at circuit level, it was determined no switching ratio exists that reinforces both the HRS and LRS state boundaries as chosen here at RHRS,min = 12.8kΩ and RLRS,max = 4.4kΩ for V = 0.5 V. However, a 5.1x reduction in resistance drift compared to conventional unipolar read was still obtained.Computer Engineerin
Isogeometric analysis of fluid cellular membranes: Application of discrete exterior calculus and isogeometric analysis to Stokes flow on time-evolving surfaces
No full textAn isogeometric finite element method for incompressible fluid film equations is presented. The method can be applied to numerically model the behaviour of thin cellular membranes, such as lipid bilayers. The membranes are represented by infinitely thin closed surfaces. Both the surface parametrization and analysis are based on state-of-the-art polar spline spaces. These spaces are defined such that a C1 continuous genus 0 surface can be constructed. At the discrete setting, point-wise conservation of mass is attained, using the framework of discrete exterior calculus. Therefore, the polar spline spaces are called divergence conforming. Time discretization of the highly non-linear system is done via the fixed-point iterations. It is found that for certain non-uniformly curved domains, the iterations converge and time stepping can be performed. However, for surfaces that are closely resembling a perfect sphere, the iterations are not stable for any ∆t. The solution is parameter-dependent and this indicates a possible bug in the Matlab code.Animation of the basic domain: https://youtu.be/YBrJwtOAqZ8 Gitlab project, containing the Matlab code that was used for this research: https://gitlab.tudelft.nl/hmverhelst/lipid-bilayersApplied Mathematic
An Evaluation of Next Generation Rocket Engines for VT SSTO RLV
No full textObserving that the majority of SSTO programs failed due to the propulsion system being far ahead of its time. Furthermore, acknowledging the that the private launch markets is increasingly dominated by partly reusable TSTOs. This thesis aims to evaluate whether next generation rocket engines make an SSTO viable within a foreseeable economical time frame, for the increasingly privatised space industry. From the market analysis it follows that the VT SSTO RLV developed by the private launch industry, with a payload capability of 15- 20 tons to a LEO with an altitude of 200-400 km, is most likely. The evaluation is performed by a two level trade-off. Initially, a literature trade-off is preformed on elaborate range of potential next generation rocket engine, which are subdivided into pure rocket engine and breathing engine. All engines are evaluated on the market requirements, performance, and achievability. Only three engine types are selected. Upon evaluating the propulsion literature it was noticed that no literature cross evaluated advanced propulsion systems with high performance propellant pallets. Therefore, a literature propellant trade-off is performed. For the aerospike, the pulse detonation engine and the precooled hybrid airbreathing rocket engine with the propellant pallets H2/O2, CH4/O2, C2H2/O2, and C2H4/O2 a performance analysis is performed. The performance analysis is done by both optimising the engine configurations and the ascent trajectory for a 15 ton payload delivery to an orbit of 400 km altitude. To simulate each engine, three performance analysis are developed, which are all derived from the continuity equations to ensure a consistent comparison. The aerospike is simulated as a continuous optimal convectional via the frozen equilibrium method, although it is found an alternation is needed to account for directional losses. The open-end of the PDE is simulated via a CJ-detonation wave followed by an exponential decaying blowdown phase. The DC nozzle expansion is iteratively simulated via the frozen equilibrium method. The intake and HPC of the precooled hyrbid airbreathing engine is simulated with convectional aero engine performance analysis, while the precooler is simulated ass a counter-flow heat exchanger. The CC and CD nozzle are simulated via the frozen equilibrium method. From the optimised trajectory the representative performance of each engine is extracted and five engine configurations are identified as viable VT SSTO RLV engines. These are the H2/O2 powered aerospike, the pulse detonation engine and the precooled hybrid airbreathing rocket engine operating on an H2/O2 pallet, and the C2H2/O2 powered aerospike and pulse detonation engine. The H2/O2 powered PDE is found to be the most promising, as it offers the best performance gain relative to its achievability. Therefore, it advocates that future VT SSTO RLV research utilises the H2/O2 powered pulse detonation engine as the main propulsion systemAerospace Engineerin
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