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The problem of single-snapshot direction of arrival (DoA) estimation with antenna arrays has been considered. A sectorized approach based on Bayesian Compressive Sensing (BCS) has been proposed. In this method, the angular space is discretized, defining many non-overlapping small grids which cover the desired large angular space. First, a BCS estimation is run in each of the sectors to estimate the DoA of the signals. Then, a second stage is performed to correct the inconsistencies at the edges due to signal leaking between sectors. The performance of the method has been analyzed via extensive Monte-Carlo simulations in which the number of targets, their Radar Cross Section (RCS), and their location have been varied in a large extent, and the targets were observed by a Frequency Modulated Continuous Wave (FMCW) radar with an 86-element Uniform Linear Array (ULA). The results are compared with state-of-the-art methods in terms of estimation accuracy and resolution. Moreover, an analysis of the computational time, critical for many real-time applications, is presented, which shows a reduction of 20 times in the computational time compared with the standard BCS. Finally, the method has also been validated using experimental data collected with a commercial automotive radar., Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Microwave Sensing, Signals & Systems

Direction of Arrival (DoA) estimation is an important topic in radar application and has significant importance for advanced driver assistant systems in the automotive industry. While there is an increasing need for higher resolution and increased target detection and DoA estimation performance, such improvements often require increased hardware cost, complexity and size. With the increase in computational power of modern systems, Compressive Sensing methods have become more attractive as alternative methods for DoA estimation to the established ones, which often rely on uniform linear arrays (ULA) and the acquisition of multiple snapshots to provide good performance. Compressive Sensing methods have been shown to fit very well into the DoA estimation framework and have the ability to use far fewer snapshots, provide super resolution capabilities and by nature, utilise sparse spatial sampling, i.e. sparse antenna arrays. The latter point is the key incentive of this thesis. Specifically, Bayesian Compressive Sensing (BCS) which in addition to point estimates also provides measures of uncertainty is used in this thesis, to generate and use sparse linear array structures for DoA estimation. In particular, the entropy of the recovered coefficient vector is reduced in each step. Two array generation algorithms are proposed building on the same concept to generate sensor arrays for the consideration of a uniformly spaced, linear grid of possible sensor locations and for a Multiple In Multiple Out (MIMO) array setup. Utilising sparse arrays with BCS has the potential to reduce the hardware complexity of the circuit board, reduce energy consumption and heat generation, as well as ultimately saving costs in production and operation. The proposed array generation algorithms are first tested and assessed with simulated Frequency-Modulated Continuous-Waveform (FMCW) radar data, where it is shown that the generated algorithms achieve good estim, Electrical Engineering | Signals and Systems

The thermal environment in educational buildings is crucial to improve students’ health and productivity, as they spend a considerable amount of time in classrooms. Due to the complexity of educational buildings, research performed has been heterogeneous and standards for thermal comfort are based on office studies with adults. Moreover, they rely on single dose-response models that do not account for interactions with other environmental factors, or students’ individual preferences and needs. A literature study was performed on thermal comfort in educational buildings comprising of 143 field studies, to identify all possible confounding parameters involved in thermal perception. Educational stage, climate zone, model adopted to investigate comfort, and operation mode were then selected as confounding parameters and discussed to delineate the priorities for future research. Results showed that children often present with different thermal sensations than adults, which should be considered in the design of energy-efficient and comfortable educational environments. Furthermore, the use of different models to analyse comfort can influence field studies’ outcomes and should be carefully investigated. It is concluded that future studies should focus on a more rational evaluation of thermal comfort, also considering the effect that local discomfort can have on the perception of an environment. Moreover, it is important to carefully assess possible relationships between HVAC systems, building envelope, and thermal comfort, including their effect on energy consumption. Since several studies showed that the perception of the environment does not concern thermal comfort only, but it involves the aspects of indoor air, acoustic, and visual quality, their effect on the health and performance of the students should be assessed. This paper provides a way forward for researchers, which should aim to have an integrated approach through considering the positive effects of indoor exp, Indoor Environment

This work presents the MoonWEC, a new device for wave energy conversion. This new concept encompasses several working principles as the heaving point absorber, the oscillating water column and the overtopping. The development of the new WEC has been carried out through numerical modelling. Three main parts of the device have been simulated: a hollow floating structure, a central moonpool and a CALM mooring system. All the parts of the model have been coupled to obtained the general behaviour of the device under the effect of irregular sea states. The device has been designed according to the Mediterranean Sea wave climate. Its dimensioning aims to maximize the power absorption by tuning both,device and moonpool, natural periods with the identified prevailing sea states. Six mooring system configurations have been tested in order to obtain a stable, safe and yet effective behaviour. Finally, performance indicators have been drawn to assess power production in two selected locations in the Mediterranean Sea., Coastal Engineering

Huge efforts have been done in the last years on electrochemical and photoelectrochemical reduction of CO 2 to offer a sustainable route to recycle CO 2 . A promising route is to electrochemically reduce CO 2 into CO which, by combination with hydrogen, can be used as a feedstock to different added-value products or fuels. Herein, perpendicular oriented TiO 2 nanotubes (NTs) on the electrode plate were grown by anodic oxidation of titanium substrate and then decorated by a low loading of silver nanoparticles deposited by sputtering (i.e. Ag/TiO 2 NTs). Due to their quasi one-dimensional arrangement, TiO 2 NTs are able to provide higher surface area for Ag adhesion and superior electron transport properties than other Ti substrates (e.g. Ti foil and TiO 2 nanoparticles), as confirmed by electrochemical (CV, EIS, electrochemical active surface area) and chemical/morphological analysis (FESEM, TEM, EDS). These characteristics together with the role of the TiO 2 NTs to enhance the stability of CO 2 ·- intermediate formed due to titania redox couple (Ti IV /Ti III ) lead to an improvement of the CO production in the Ag/TiO 2 NTs electrodes. Particular attention has been devoted to reduce the loading of noble metal in the electrode(14.5 %w/%w) and to increase the catalysts active surface area in order to decrease the required overpotential., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., ChemE/Catalysis Engineering

Summary of all results of the Delos (Environmental design of low crested structures) project. Objectives of Delos were (1) to provide an inventory of Low Crested Structures (LCS), (2) analyse LCS hydrodynamic an stability and their effects on morphology (3) investigate impacts of LCS (4) develop methodology for Integrated Coastal Zone Management (5) provide guidelines for the design of LCS. This report is the administative final report. For technical details is referred to the book "Environmental design guidelines for low crested coastal structures" by Burcharth et.al., Delos

The present report, produced within the framework of the EU funded project DELOS, attempts to recognise and analyse main scale effects in the physical modeHing of rubble mound breakwaters used in offshore and coastal engineering. Scale effects appear in physical modeHing because the ratios between the farces of interest, as present in prototype, cannot be maintained in a scaled model. The report is by no means intended to resolve the problems associated with scale effects, given the complexity of this issue. However this discussion provides a preliminary understanding of these effects. Respect to the aforementioned objectives, the present report is structured as foHows. The properties of sea water are summarised in Section 2. Section 3 provides a brief overview of sealing rules used in hydraulic physical modeHing. Section 4 is dedicated to surface tension effects on breakers. Section 5 deals with the complex problem of sealing air content from prototype sea water to model fresh water. A general overview of main scale effects in relation to the different processes associated to the interaction between waves and rubble mound breakwaters is presented in Section 6. Sealing of movable-bed models are addressed in Section 7. The effects of marine organisms on water and mound units are described in Section 8. In Section 9 conclusions are drawn, which summarise the main points worth consiclering when addressing the problem of scale effects in wave-related models with rubble mound breakwaters. Selected issues are further discussed in the attached appendices. Example of the Hydrodynamics at Pellestrina. Example of the sediment budget at Lido de Pellestrina., Delos

Economic evalulation of the recreational beaches at Lido di Dante, Trieste, Ostia and Pellestrina Island. Assessment of option value and non-use values at Venice and Normerven (Netherlands). Prefence of different structures and beach materials, case of Lido di Dante, Ostia and Pellestrina Island., Delos

In order to develop a model able to describe how berm breakwaters reshape under the attack of waves, a large quantity of data from 2D and 3D tests was collected and arranged in a database. The data were first standardised, and since data come from models with very different size, all the lengths were scaled with the nominal diameter (Dn50) of berm stones. Since the information regarding the wave conditions in shallow water or in front of the breakwater was not always available the wave conditions were estimated in front of the breakwater by using formulae proposed by Goda (1985) and Stive, (1986). The profiles were schematised as suggested by Vellinga (1986) and van der Meer (1988) using six parameters; with the aid of PCA the original variables were transformed into uncorrelated components describing decreasing quotes of the total variance. Three of them account for 95% of the variance of our data-base. In this manner the dimensionality of the phenomenon was reduced from six to three. Each component describes part of the behaviour of the reshaping breakwater and for each of them a model was developed relating components to the environmental and structural parameters. The model respects approximately (relatively to the 1st PC) the composition principle and gives results for any condition. At the end the model was compared with the experimental profiles and with the output of BREAKWAT., Berm Breakwaters

Berm or reshaping breakwaters represent a relatively new -type of wave barrier; more precisely the conscious acceptation of stone movement during reshaping and of the eventual dynamic equilibrium of the units in the exposed mound is new. Stones of the armour layer are accepted to move under the wave attack until a new equilibrium of the seaward profile is formed. The shape of the new profile was already studied, and a model was developed providing a typical shape and parametrisation (Vellinga, 1986) and equations describing the evolution of the profile characteristic points under some assigned wave attack (Van der Meer, 1988). The purpose of this paper is to check the goodness of the existing model, to recalibrate it, if it is felt necessary, using the wider data-set that was reconstructed from several experiments carried out in the last years, and, eventually, to suggest a description of the profile using a smaller number of equations and parameters., Berm Breakwaters

During the last few decades the believe that absolute security could be provided has been recognized to be mistaken in many branches of engineering. This happens as a consequence of the imperfect predictability of load intensity, structural characteristics and structural behavior, as well as a consequence of human gross errors during the design and construction phases or during the using (exploiting) period. In the field of coastal engineering this became particularly evident when breakwaters were constructed in deep-water condition, i.e. where water-depth ceases the beneficial effect in limiting the design wave height. Beyond this special case, it is rat her common in coastal engineering practice to dwell with uncertain environmental conditions and sometimes even with uncertain structural behavior. A method which can account for the multiform information available and which can produce a rational risk evaluation is therefore highly advisable. A rationalization of the risk assessment produce some advantages: 1 - The various uncertainties are rationally incorporated and balanced in the assessment of the reliability of the structure. 2 - A more balanced design of components of the overall system can he made, avoiding the coexistence of overdesigned components blowing up the costs and of underdesigned components causing the risk. 3 - Cost of the structural solution to risk (building a stronger structure) can be assessed and compared to the non structural solution (reducing the uncertainty). 4 - A better insight into how the failure probability is built up from the various uncertainties is obtained: priorities can he established for further research aiming to improve the description of the system and reduce the uncertainty margins. In the example presented failure and risk are looked at from the client point of view. CONCLUSIONS A complete and objective risk assessment is not always possible due to the lack of reliable models for some of the relevant failure modes. A mo, ICCE 1992