9 research outputs found
Efficient Modeling of Complex Sandy Coastal Evolution at Monthly to Century Time Scales
With large-scale human interventions and climate change unfolding as they are now, coastal changes at decadal timescales are not limited to incremental modifications of systems that are fixed in their general geometry, but often show significant changes in layout that may be catastrophic for populations living in previously safe areas. This poses severe challenges that are difficult to meet for existing models. A new free-form coastline model, ShorelineS, is presented that is able to describe large coastal transformations based on relatively simple principles of alongshore transport gradient driven changes as a result of coastline curvature, including under highly obliquely incident waves, and consideration of splitting and merging of coastlines, and longshore transport disturbance by hard structures. An arbitrary number of coast sections is supported, which can be open or closed and can interact with each other through relatively straightforward merging and splitting mechanisms. Rocky parts or structures may block wave energy and/or longshore sediment transport. These features allow for a rich behavior including shoreline undulations and formation of spits, migrating islands, merging of coastal shapes, salients and tombolos. The main formulations of the (open-source) model, which is freely available at www.shorelines.nl, are presented. Test cases show the capabilities of the flexible, vector-based model approach, while field validation cases for a large-scale sand nourishment (the Sand Engine; 21 million m3) and an accreting groin scheme at Al-Gamil (Egypt) show the model’s capability of computing realistic rates of coastline change as well as a good representation of the shoreline shape for real situations.Coastal Engineerin
The introduction of Corded Ware Culture at a local level: An exploratory study of cultural change during the Late Neolithic of the Dutch West Coast through ceramic technology
The introduction of the Corded Ware Culture (3000–2500 BCE) is considered a formative event in Europe's past. Ancient DNA analyses demonstrate that migrations played a crucial role in this event. However, these analyses approach the issue at a supra-regional scale, leaving questions about the regional and local impact of this event unresolved. This study pilots an approach to ceramics that brings this small-scale impact into focus by using the transmission of ceramic technology as a proxy for social change. It draws on ethno-archaeological studies of the effects of social changes on the transmission of ceramic production techniques to hypothesise the impact of three idealised scenarios that archaeologists have proposed for the introduction of Corded Ware Culture: migration, diffusion, and network interactions. Subsequently, it verifies these hypotheses by integrating geochemical (WDXRF), mineralogical (petrography), and macromorphological analysis of ceramics with network analysis. This method is applied to 30 Late Neolithic ceramic vessels from three sites in the western coastal area of the Netherlands (Hazerswoude-Rijndijk N11, Zandwerven, and Voorschoten-De Donk). This study concludes that the introduction of Corded Ware material culture is a process that varies from site to site in the western coastal area of the Netherlands. Moreover, the introduction of the Corded Ware Culture is characterised by continuity in technological traditions throughout the study area, indicating a degree of social continuity despite typological changes in ceramics.(OLD) MSE-
Reduced complexity modeling of shoreline response behind offshore breakwaters
Prediction of the shoreline response behind offshore breakwaters is essential for coastal protection projects. Due to the complexity of the processes behind the breakwaters (e.g., wave diffraction, currents, longshore transport), detailed modelling needs high computational efforts. Therefore, simplifying the process effect in a simpler coastline model could be efficient. In this study, the coastline evolution model ShorelineS is used. A new routine was implemented in the model to adjust the wave heights and angles behind the offshore breakwaters. Two approaches from the literature and a newly introduced one were tested in this study. The model free grid system was used to simply track the breaker line; such an advantage also helped to form tombolo, which is not common for these types of models. The tests showed promising results for single and multi breakwaters systems; however, the newly introduced approach still needs further testing and refinement for better performance and less computational cost.Coastal Engineerin
Ceramic-faience hybrids were used to recycle bronze in North-Western European Iron Age egg-shaped crucibles
We investigated the characteristics of a group of 13 Middle Iron Age egg-shaped crucibles and crucible fragments from Tilburg (The Netherlands). We used a combination of optical and chemical analyses, including hand-held XRF, microCT scanning and 3-D printing polarizing light microscopy and SEM-EDX. The chemical analyses confirmed that the crucibles were used for copper alloy metallurgy. Impressions in the lids of the crucibles turned out to be imprints of copper alloy scrap, including fragments of twisted wire and fibulae. Most remarkable, however, is the large proportion of sheet metal among the scrap.In order to make crucibles from the local, non-refractory clays, a hitherto unknown ceramic-faience hybrid was used: A combination of clay and halophytic plant ash was mixed with silt into a paste, and this was used to construct the crucible. During firing, the flux would promote melting of the clays and probably prevent catastrophic failure of the crucibles. The resulting glassy groundmass – in which silt grains are embedded and partially dissolved – is rich in Al2O3 as well as in Na2O, K2O, CaO, MgO and Fe2O3.It is likely that this technique of crucible manufacture was widespread in Late Prehistory in areas where no refractory clays were available.Geo-engineerin
Resonance as a Design Strategy for AI and Social Robots
Resonance, a powerful and pervasive phenomenon, appears to play a major role in human interactions. This article investigates the relationship between the physical mechanism of resonance and the human experience of resonance, and considers possibilities for enhancing the experience of resonance within human–robot interactions. We first introduce resonance as a widespread cultural and scientific metaphor. Then, we review the nature of “sympathetic resonance” as a physical mechanism. Following this introduction, the remainder of the article is organized in two parts. In part one, we review the role of resonance (including synchronization and rhythmic entrainment) in human cognition and social interactions. Then, in part two, we review resonance-related phenomena in robotics and artificial intelligence (AI). These two reviews serve as ground for the introduction of a design strategy and combinatorial design space for shaping resonant interactions with robots and AI. We conclude by posing hypotheses and research questions for future empirical studies and discuss a range of ethical and aesthetic issues associated with resonance in human–robot interactions.Design AestheticsHuman Information Communication Desig
Resonant Pumping of d-d Crystal Field Electronic Transitions as a Mechanism of Ultrafast Optical Control of the Exchange Interactions in Iron Oxides
The microscopic origin of ultrafast modification of the ratio between the symmetric (J) and antisymmetric (D) exchange interaction in antiferromagnetic iron oxides is revealed, using femtosecond laser excitation as a pump and terahertz emission spectroscopy as a probe. By tuning the photon energy of the laser pump pulse we show that the effect of light on the D/J ratio in two archetypical iron oxides FeBO3 and ErFeO3 is maximized when the photon energy is in resonance with a spin and parity forbidden d-d transition between the crystal-field split states of Fe3+ ions. The experimental findings are supported by a multielectron model, which accounts for the resonant absorption of photons by Fe3+ ions. Our results reveal the importance of the parity and spin-change forbidden, and therefore often underestimated, d-d transitions in ultrafast optical control of magnetism.QN/Caviglia La
Integrated Decision Support Tools for Disruption Management
During railway operations unexpected events can require railway operators and infrastructure managers to adjust their schedules. In this research we investigate the disruption management process. More specifically, we come up with an architecture and algorithmic framework which railway operators could use for decision support during disruptions. The use of this framework results in a fully feasible timetable, rolling stock plan, and crew schedule to deal with the disruption, while minimizing the number of delayed and/or (partially) cancelled trains. We demonstrate the effectiveness of our framework on a disruption case on the Dutch Railway network, which is introduced within the EU FP7 project ON-TIME.Transport & PlanningCivil Engineering and Geoscience
Design and evaluation of a personal robot playing a self-management education game with children with diabetes type 1
Objective To assess the effects of a personal robot, providing diabetes self-management education in a clinical setting on the pleasure, engagement and motivation to play a diabetes quiz of children (7–12) with type 1 diabetes mellitus (T1DM), and on their acquisition of knowledge about their illness. Methods Children with T1DM (N = 27) participated in a randomized controlled trial (RCT) in which they played a diabetes mellitus self-management education (DMSE) game, namely a diabetes quiz, with a personal or neutral robot on three occasions at the clinic, or were allocated to a control group (care as usual). Personalised robot behaviour was based on the self-determination theory (SDT), focusing on the children's needs for competence, relatedness and autonomy. The SDT determinants pleasure, motivation and diabetes knowledge were measured. Child-robot interaction was observed, including level of engagement. Results Results showed an increase in diabetes knowledge in children allocated to the robot groups and not in those allocated to the control group (P =.001). After three sessions, children working with the personal robot scored higher for determinants of SDT than children with the neutral robot (P = .02). They also found the robot to be more pleasurable (P =.04), they answered more quiz questions correctly (P =.02), and were more motivated to play a fourth time (P = .03). The analysis of audio/video recordings showed that in regard to engagement, children with the personal robot were more attentive to the robot, more social, and more positive (P < .05). Conclusion The study showed how a personal robot that plays DMSE games and applies STD based strategies (i.e., provides constructive feedback, acknowledges feelings and moods, encourages competition and builds a rapport) can help to improve health literacy in children in an pleasurable, engaging and motivating way. Using a robot in health care could contribute to self-management in children with a chronic disease and help them to cope with their illness.Design Aesthetic
Cortical Spreading Depression Causes Unique Dysregulation of Inflammatory Pathways in a Transgenic Mouse Model of Migraine
Familial hemiplegic migraine type 1 (FHM1) is a rare monogenic subtype of migraine with aura caused by mutations in CACNA1A that encodes the α1A subunit of voltage-gated CaV2.1 calcium channels. Transgenic knock-in mice that carry the human FHM1 R192Q missense mutation (‘FHM1 R192Q mice’) exhibit an increased susceptibility to cortical spreading depression (CSD), the mechanism underlying migraine aura. Here, we analysed gene expression profiles from isolated cortical tissue of FHM1 R192Q mice 24 h after experimentally induced CSD in order to identify molecular pathways affected by CSD. Gene expression profiles were generated using deep serial analysis of gene expression sequencing. Our data reveal a signature of inflammatory signalling upon CSD in the cortex of both mutant and wild-type mice. However, only in the brains of FHM1 R192Q mice specific genes are up-regulated in response to CSD that are implicated in interferon-related inflammatory signalling. Our findings show that CSD modulates inflammatory processes in both wild-type and mutant brains, but that an additional unique inflammatory signature becomes expressed after CSD in a relevant mouse model of migraine.Pattern Recognition and Bioinformatic