Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine

[This corrects the article DOI: 10.1186/s13054-016-1208-6.]

Gate-based readout of hybrid quantum dot systems

Quantum mechanics yields exciting opportunities for developing novel technologies. In particular, quantum computation enables performing otherwise intractable calculations. However, unwanted disturbances to the quantum bits (qubits) form a formidable challenge for its implementation. Topologically encoding information protects against these disturbances. Qubits based on Majorana zero modes are promising for achieving topological protection and form a model application for the results of this thesis. This thesis focuses on gate-based sensing, a scalable and high-fidelity readout mechanism for solid-state quantum information processing devices. We investigate semiconductor/superconductor hybrid quantum dot devices implemented in InAs nanowires. Radio frequency (RF) techniques allow rapid and multiplexed measurements of mesoscopic systems without relying on DC-transport. As such, we show that RF measurements provide a vital tool for rapid readout and quick tune-up of semiconductor qubits. We start by presenting the theoretical foundations of quantum dots and resonators, necessary for describing the subsequent experimental results. Next, we provide relevant details concerning the experiments in this thesis. The first experiment shows the implementation of dispersive gate sensing (DGS) in a semiconductor double quantum dot (DQD). We show dispersive shifts on the order of the resonator linewidth and study its behavior for different readout powers. These shifts match theoretical expectations and allow differentiating between Coulomb blockade and resonance with a signal-to-noise ratio (SNR) of 2 within \SI{1}{\micro\second}. We subsequently apply DGS to a semiconducting quantum dot coupled to a superconducting island and observe spin-dependent tunneling and simultaneous two-particle tunneling involving Cooper pairs. By inhibiting electron tunneling to the outside leads, we bring the system to an otherwise inaccessible regime and show that DGS can probe floating systems. The third experiment replaces the MHz-resonators with on-chip superconducting coplanar waveguide resonators in the GHz regime. We extract the differential conductance quantitatively without relying on any DC calibration data. Furthermore, we obtain an SNR of 15 in 1 microsecond distinguishing Coulomb blockade from resonance in a semiconductor DQD. In the final experiment, we combine the preceding experimental results and investigate a superconducting island between two semiconductor quantum dots. We can split single Cooper pairs on demand with this geometry while retaining the resulting electrons. Secondly, we measure the electron parity using gate-based sensing in a DQD without external charge sensors. This thesis concludes by discussing the relevance of the obtained experimental results to the Majorana box qubit and suggestions for subsequent experiments. The results of this thesis show that gate-based sensing is a versatile tool in the context of mesoscopic experiments and quantum information processing devices in particular.BUS/Quantum Delf

The Effect of Network Structure and Signal Settings on the Macroscopic Fundamental Diagram

Recently it has been proposed that the performance of a complete network can be represented graphically using only aggregated data for flow and density. The resulting graph is the macroscopic fundamental diagram (MFD), which relates the average flow (performance) to the number of vehicles in the network (accumulation). The resulting shape is often concave, meaning that the performance can be maximised if a fixed number of vehicles is maintained in the network (optimal accumulation). One of the most promising methods to achieve this, is by adapting signal timings. The objective of this thesis is to investigate if (1) a relationship between the shape of the MFD and the structure of the underlying network exists and on which factors this depends and (2) if the shape of the MFD of a subnetwork (neighbourhood) and its perimeter (ring of higher level roads (with signalised intersections) around a subnetwork) are affected by different signal timings and how this does affect the applicability of the MFD for control strategies. To assess the effect of the structure on the network, a tool has been developed to automatically generate fictitious networks with different structures, in which the amount of infrastructure and signal timings are matched dynamically to a randomly generated OD-matrix. The resulting networks are used as a base for the simulations, which are done in the microscopic traffic simulator VISSIM. Using various signal timings for signals located on the perimeter, the flow from the subnetwork to the perimeter is restricted and vice-versa, in order to assess how the MFD of both react to these changes. Regarding the relation between the shape of the MFD and the network structure, it is concluded that the structure of a network in itself does not have a strong influence on the shape of the MFD. Differences between MFDs are not caused by topological differences, but by the different characteristics of the roads (length, speed, capacity) and the amount and type of intersections in the underlying network. The different factors influencing the shape of the MFD could not be quantified – in order to construct MFDs based only on knowledge of the network and without the use of simulations - as the shape of the MFD is found to differ strongly, even for similar networks. As such it is concluded that the stochastic and dynamic nature of traffic has a strong influence on the shape of the MFD. Especially the accumulation is highly sensitive to differences in the distribution of traffic over the network, making the optimal accumulation particularly hard to predict. Regarding the effect of signal settings on the shape of the MFD of a subnetwork and its perimeter and its applicability for control strategies, it is concluded that a strong relation between the MFD of the subnetwork and its perimeter does exist, in which both react in the same way to changes in traffic demand and signal timings. The ratio between the performance of the subnetwork and perimeter is highly consistent and not strongly affected by changes in the signal settings, implying that signal timings exist, which optimise the performance of both the subnetwork and its perimeter. The optimal accumulation of the perimeter is found to be highly sensitive to changes in the signal timings. As a consequence it is concluded that the MFD is difficult to use for control strategies aiming to adapt signal timings to maintain the optimal accumulation in a part of the network, because these changed signal timings result in a different optimal accumulation.Transport and PlanningTransport & PlanningCivil Engineering and Geoscience

Opwassen of verdrinken: Sedimentaanvoer naar schorren in de Oosterschelde, een zandhongerig gedempt getijdesysteem

Deze rapportage geeft de resultaten weer van twee decennia monitoring van de sedimentatie op drie schorren in de Oosterschelde en de invloed hiervan op de netto hoogteligging. Deze resultaten zijn mede een maat voor de ontwikkeling van de schorren in de Oosterschelde in de toekomst. Bij de interpretatie is uitgegaan van de werking van de fysische processen in een getijdesysteem met een enorm tekort aan zand in de geulen. Uit de resultaten is afgeleid hoe groot de sedimentaanvoer naar de schorren is geweest en wat de invloed van diverse hydromorfologische factoren hierop is. Tevens is getracht de vraag te beantwoorden hoe de ontwikkeling zich verhoudt tot de relatieve zeespiegelrijzing. De trend is dat sedimentatie van de schorren na de aanleg van de Oosterscheldewerken met een factor 2 is verminderd, wat in grote lijnen overeenkomt met wat destijds is voorspeld. De sedimentatie correleert het sterkste met het golfklimaat ter plaatse van de schorren. Verder landinwaarts in het schor neemt de sedimentatie af. Er bestaat geen duidelijke relatie tussen de mate van sedimentatie en de vegetatie. Het sediment is vermoedelijk vooral afkomstig uit het voorland en mogelijk ook voor een deel van de eroderende kliffen. Een duidelijk effect van stormen en sluitingen van de kering is niet gevonden. De eindconclusie is dat de schorren qua hoogte de relatieve zeespiegelrijzing kunnen bijhouden bij het minimum scenario hiervoor (ca 20 cm in 100 jaar). Bij het maximum scenario (ca 85 cm in 100 jaar) houdt de aanslibbing de zeespiegelstijging niet bij en zullen alle schorren op termijn verdrinken. Bij het midden scenario (ca 60 cm per 100 jaar) kunnen alleen de schorren bij Rattekaai en vermoedelijk ook enkele kleinere schorgebiedjes die onder de dezelfde condities als Rattekaai zijn gelegen, de zeespiegelstijging bijhouden, maar de andere schorren niet. Aanbevolen wordt dit soort effecten nader te kwantificeren door de schorren iedere 3 jaar op te meten qua hoogte en na verloop van enkele meetcycli hierover te rapporteren. Daarnaast kan worden gezocht naar mogelijke maatregelen voor duurzame oplossingen voor het behoud van de schorren.MON*MOR

Umhlanga Rocks coastal defense

The eThekwini coastline is a vulnerable coastline subject to chronic erosion and damage due to sea level rise. In 2007 a severe storm caused major physical and economic damage along the coastline, proving the need for action. Umhlanga Rocks is a densely populated premium holiday destination on the eThekwini coastline suffering from similar problems due to its narrow beaches and lack of dunes in certain places. Interference with the coast of Umhlanga can entice fierce resistance from different groups of stakeholders, which makes finding a suitable solution more difficult. The above leads to the following problem definition: Due to erosion and extreme weather conditions the coastline of Umhlanga Rocks is shifting on shore, causing narrow beaches, decrease of tourism and increased risk of failures of the coastal structures. The current situation requires a new long term safety strategy, taking into account the social, economic and environmental vitality of the Umhlanga Rocks area as well. To solve the problem definition the main question states: How can the eThekwini municipality create a sustainable Umhlanga coastline while adding value to the area? To answer the main question many different elements, varying from conventional coastal protection measures to experimental ideas that would increase local business, were formulated during a brainstorm session. These elements are ranked on their cost, added value and technological feasibility. From the highest ranked elements in each category 11 different alternatives are created. By performing a multi criteria analysis these 11 alternatives are narrowed down to three alternatives and an additional `do nothing’ option is included. The do nothing option assumes that the beach will be completely gone in 30-40 years. It is further assumed Umhlanga Rocks recreational businesses are coupled to the beach and property values will drop by 12% once the beach is gone. This gives a NPV of R.15,000,000,000. It is suspected that the equilibrium that normally exists in the cross shore sediment transport is disturbed and more sediment moves offshore than onshore. The sill is designed to prevent the sediment form moving too far offshore and thus to create a new equilibrium. The bar retaining sill consists of prefab concrete elements located just outside the surf zone. From the Delft3D model it followed that the beach stays roughly the same size after construction of the sill. The NPV bases the cost of the sill on reference projects. With the beach maintaining its current size the total NPV amounts to R.116,000,000,000. The nourishment option adds enough sand to the beach to compensate for erosion and add 15 meters of beach according to the Delft3D model. It is assumed the nearby sand depot can be used to perform the nourishment. The nourishment itself will be done using a dredger connected to a floating pipeline to pump the sand to the beach. Shovels will be used to divide the sand over the beach area. The cost of the nourishment is based on the cost of a similar project, with the benefit of the added beach area the total NPV is R.142,000,000,000. The submerged breakwater creates a calmer wave climate near the coast and will thereby reduce erosion and increase beach growth. The Delft3D model suggests an average beach growth of 20 meters. For the breakwater design different materials are considered. Geotextile systems look very promising and have several advantages over a rock or concrete breakwater. A design with geotextile bags and one with geotextile tubes is made for the Umhlanga Rocks area. The NPV of the breakwater amounts to R.131,000,000,000. A second multi criteria analysis is performed to determine the overall best option. According to this analysis the construction of a submerged breakwater made of geotextile tubes provides the best solution to the problem from social and technical preferences. Social preferences include perceptions of stakeholders involved like environmental groups and property owners, but take the construction and maintenance costs of the alternative into account as well. In this case the geotextile tube breakwater uses conforming materials, does not cause any visual horizon pollution and seems to deliver the best benefits for the price involved. At the same time the results from the 3D simulations have shown that the breakwater is able to perform well on the technical preferences including the breakage of waves offshore and increase of beach width.Hydraulic EngineeringCivil Engineering and Geoscience

Eerste ervaringen met de gewijzigde Wet voorkeursrecht gemeenten; onderzoek in opdracht van de Rijksplanologische Dienst

De gewijzigde Wet voorkeursrecht gemeenten is op 17 juli 1996 in werking getreden. De wetswijziging werd door de regering noodzakelijk geacht om de (VINEX) verstedelijkingstaakstelling beter te kunnen realiseren. Vanuit de Kamer en van betrokkenen rond deze verstedelijkingstaakstelling, zowel uit de publieke als de private sector, kon de wetswijziging op bijval rekenen. Er werd veel verwacht van de wet in verband met het voorkomen van knelpunten rond het realiseren van het verstedelijkingsbeleid. Toch was de concrete invulling van de wetswijziging niet onomstreden. Vragen werden gesteld als: Gaan de mogelijkheden van de wet wel ver genoeg? Is de wetswijziging geen 'mosterd na de maaltijd'? Is de wet voldoende werkbaar? Maar ook: Past de wet wel in een tijdperk waar marktwerking rond de ruimtelijke inrichting steeds belangrijker wordt gevonden? Gaat de ingreep op de particuliere beschikkingsmacht niet te ver? Vanuit de Kamer is er - mede daarom - op aangedrongen dat er binnen enkele jaren na inwerkingtreden een evaluatie van de wet zal plaats vinden. Uiteindelijk is een amendement aangenomen (amendement Stellingwerf), waarin is bepaald dat binnen vier jaar na inwerkingtreding van de wet de minister een verslag aan de Tweede Kamer zendt over de doeltreffendheid en de effecten van de wet in de praktijk. Dat betekent dat deze rapportage uiterlijk medio 2000 moet plaatsvinden. Ten behoeve van de voorbereiding van dit evaluatie-onderzoek is het onderzoek 'Evaluatie Wet voorkeursrecht gemeenten: fase l ' uitgevoerd. Besloten is de rapportage over dit onderzoek in tweeën te splitsen: een eerste rapport heeft direct betrekking op het straks uit te voeren evaluatie-onderzoek, een tweede rapport op de eerste ervaringen met de Wvg, die de Rijksplanologische Dienst graag nu ook in kaart zag gebracht. Deze publicatie betreft dit laatste rapport. Het rapport had niet tot stand kunnen komen zonder de bereidwillige - en vaak enthousiaste - medewerking van betrokkenen rond de uitvoering van de Wvg. Een woord van dank is hier dan ook op zijn plaats aan allen die hun medewerking hebben verleend en bereid waren soms vertrouwelijke informatie aan ons ter beschikking te stellen: betrokken overheden (provincies en gemeenten), het notariaat, betrokken marktpartijen en belangenorganisaties, in het bijzonder het Kadaster en de Koninklijke Notariële Beroepsorganisatie. Een ding is ons in elk geval duidelijk geworden: de Wvg leeft, zeker ook in de uitvoeringspraktijk. Het onderzoek is uitgevoerd door de Sectie Geo-informatie en Grondbeleid van de subfaculteit Geodesie van de TU Delft, door een onderzoeksteam bestaande uit ir. D.A. Groetelaers (toegevoegd onderzoeker), prof. mr. J. de Jong (hoogleraar onroerendgoedrecht), prof. dr. w.K. Korthals Altes (hoogleraar grondbeleid) en ir. H. W. de Wolft (universitair docent

Expert knowledge for automatic detection of bullies in social networks

Cyberbullying is a serious social problem in online environments and social networks. Current approaches to tackle this problem are still inadequate for detecting bullying incidents or to flag bullies. In this study we used a multi-criteria evaluation system to obtain a better understanding of YouTube users? behaviour and their characteristics through expert knowledge. Based on experts? knowledge, the system assigns a score to the users, which represents their level of \u93bulliness\u94 based on the history of their activities, The scores can be used to discriminate among users with a bullying history and those who were not engaged in hurtful acts. This preventive approach can provide information about users of social networks and can be used to build monitoring tools to aid finding and stopping potential bullies

West-east policy transfer: The case of urban transport policy

European policies on urban transport policy attach great importance to the role of best practices in promoting urban sustainability. The underlying assumption appears to be that best practices are equally applicable and effective in other parts of Europe. However, the current size of the European Union and the diversity of member states, especially since the accession of 12 new member states since 2004, draw this assumption into question. There are after all substantial differences in governance, administrative cultures and professional capacities across the 27 member states of the European Union. To date, research in the field has neither fully nor satisfactorily explored the issue of transferability of best practices, especially from west to east Europe (i.e. from ‘old’ to ‘new’ member states). What is already known about the transfer of policy models, concepts, ideas, goals and instruments from west to east Europe is that drawing lessons from the west has often been seen by countries in central and eastern Europe as a way of catching up politically and economically (Rose, 1993). The uncertainties of policy making in some of these countries have made policy transfer a particularly attractive option, as politicians see it as the quickest solution to many problems without having to reinvent the wheel (Rose, 2005; Tavits, 2003). However, the technological, economic, political and social situations in the ‘lending’ and ‘borrowing’ countries are often very different. So too are the institutional frameworks. As a consequence, the transfer process is far from straight-forward and certainly not just a matter of copying or emulation. The paper employs a case study approach to examine two closely related projects (funded by the German government) that both sought to transpose policy concepts between west and east Europe. Both projects focused on transferring the underlying concepts and principles behind German public transport executives (Verkehrsverbünde) as a way of promoting public transport and improving environmental quality in two cities in new member states of the European Union: Riga in Latvia and Wroclaw in Poland. In both cases, The paper draws on policy transfer theory to help explain the transferability of policy models, concepts, ideas, goals and instruments between west and east Europe, and to help evaluate the factors of success and failure in the specific cases of Riga and Wroclaw.Urban and Regional DevelopmentOTB Research Institut