270 research outputs found
Same sign W Boson production in double parton interactions
No full textThe LHC physics program is now in full swing and has already turned heads in Stockholm. More discoveries are literally in the making, as the size of the recorded data set and the available energy range is ever increasing. So what is the LHC, and in specific ATLAS, looking for? Basically the entire accelerator and detector complex is one gigantic microscope. It searches for the smallest building blocks of nature, or elementary particles. Much like a Lego kit is build out of small elementary building blocks. Quite a few of those elementary particles are already discovered, like the familiar electrons and photons (light particles). Some examples of less familiar particles but similar in the fact that they are elementary are quarks, W and Z bosons, and the recently discovered Higgs boson among others. All these elementary particles interact with each other, bouncing off of each other and even destroying one another. A lot of these processes are already studied and documented in the Standard Model of particle physics, but not all. One previously unseen process that is about to be uncovered is W boson pair production in Double Parton Interactions. The process consists of two semi-separate productions of a W boson in a single proton-proton collision. Since this type of process requires the interaction of four initial particles, the dependence of these four parents on one another can be investigated in this case. The results of the analysis show that the W boson pair production in DPI events is still an elusive process. The main contamination of the signal comes from the difficulty to properly reconstruct events with a different signature. The two main background processes are identified, and should be the main focus of future research into this process. When more data is acquired the cuts can be tightened, improving the signal to noise ratio. When the noise level is low enough real physics can be done to unravel more of the proton structure mysteries. The amount of data used in this analysis is recorded over the course of about a year. The ATLAS detector is planned to run for at least a couple of decades at increasing event rates, so the problem of too little signal events should be solved in the coming years. This gives positive prospects for the physics potential of the W boson pair production in DPI events
SSA Back-Translation: Faster Results with Edge Splitting and Post Optimization
No full textA compiler translates one representation of a software program into another. Beside translation compilers often have other tasks such as optimizating the result and warning the programmer for mistakes. Internally a compiler uses an Intermediate Representation (IR) for analysis and manipulation of the program at hand. Data dependencies in most programming languages are implicit. Some compilers use an IR in Static Single Assignment (SSA) in which each local variable is only defined once to simplify analysis of data dependencies. If the number of assignments in the IR is not restricted, it is said to be in normal form. Input of a compiler is in normal form and translation is needed to bring the IR in SSA form. SSA-form contains phi functions to merge values based on control flow. After optimizations on SSA-form are performed it is not trivial to translate SSA-form back to normal form because the properties of phi nodes cannot be translated directly to processor instructions. The algorithms of Briggs and Sreedhar are the two major methods of back-translation. This thesis presents a modification that can be applied to the methods of Briggs and Sreedhar. The original methods append copy instructions to the end of existing source blocks. The presented modification splits edges between source and target by inserting phiblocks where the algorithms of Sreedhar and Briggs emit copy operations to replace phi functions. For this study a bridge between LLVM and CoSy was built such that LLVM can be used for the optimizations on SSA-form and CoSy for the post back-translation optimizations. Four back-translation algorithms are implemented in CoSy. The methods are compared through experiments with six testcases from the SPEC benchmark suite. On average the presented modification reduces the execution time of the resulting code with 5% for Briggs’ method and 3% for Sreedhar’s method. Experiments also show that the result of back-translation with or without phiblocks is suboptimal: repeating optimizations after back-translation that were already done on the IR in SSA-form can reduce the execution time on average with 18%.Computer EngineeringMicroelectronics & Computer EngineeringElectrical Engineering, Mathematics and Computer Scienc
Tidal Response to Land Reclamation in Single- and Multichannel Estuarine Systems
No full textIntertidal areas play a crucial role in controlling tidal hydrodynamics and morphodynamics in estuaries and tidal inlets. As a consequence, widespread land reclamation of the intertidal zone has led to alterations in tidal dynamics and the associated morphodynamics of estuaries worldwide. Comparatively little research has focussed on the impact of width changes on tidal hydrodynamics, and results that do exist are highly ambiguous (Talke and Jay, 2020). Tie channels in between parallel inlets complicate the tidal motion, as multichannel systems exhibit a hydrodynamic response that differs significantly from the response observed in single channel systems. In this study, we combine idealized process-based modelling and historical data analysis to investigate the effects of intertidal land reclamation on the tidal dynamics of single- and multichannel systems. Specifically, we focus on the Scheldt and Pasur-Shibsa estuaries, which represent a single- and multichannel system, respectively.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.Environmental Fluid Mechanic
DBFM(O) bij scholen: Perspectief; luchtkasteel of schoolgebouw
No full textIn dit onderzoek is bekeken of een langdurige contractrelatie van een DBFM(O) geschikt is voor het ontwikkelen van scholen en of het antwoord geeft op de problemen van onderwijshuisvesting.Architectur
Developing a Population Synthesis Method based on Lifestyles towards Mobility for Travel Demand Modelling
No full textCivil Engineering and GeosciencesTransport & Plannin
Boeren met water, waterberging in combinatie met landbouw
No full textHet project Boeren met Water is een onderzoeksproject in opdracht van de provincie Noord-Holland, de Noord-Hollandse waterbeheerders en Habiforum. Het is een van de vier projecten van het onderzoeksprogramma Meervoudig Ruimtegebruik met Waterberging in Noord-Holland. Boeren met Water verkent de mogelijkheden om waterberging te combineren met agrarische bedrijfsvoering. Het is een toekomstgerichte studie die invulling geeft aan de wateropgaven die in de nota Waterbeleid voor de 21e eeuw worden geformuleerd. De studie is tot stand gekomen in nauwe samenwerking met een studiegroep van agrarisch ondernemers uit de Zeevang en de Beemster. Samen met de betrokken waterbeheerders hebben zij bijgedragen aan het ontwikkelen van nieuwe kennis ten aanzien van meervoudig ruimtegebruik. Het project is uitgevoerd door het Centrum voor Landbouw en Milieu.KWP-collectio
The future of floriculture logistics: A logistic design for the floriculture chain for the year 2025, incorporating feasible trends and developments
No full textThroughout this report a logistic design for the floriculture supply chain from the growers to the buyers of the flower auction is developed to be feasible around the year 2025. Trends and developments in and around the floriculture market as consolidation of transport, shift in customer demand and the Internet of Things are plotted on a hype cycle to test which trends are feasible in this market on the mid-term. This analysis in combination with a relationship analysis results in two solution directions that include a lot of other trends and developments and could be feasible to implement before 2025. Those two solution directions are a virtual storage and a hub-network and are elaborated into conceptual designs. These designs operate on different levels and could be combined for a future logistic design. In this final design, storage hubs and transit hubs will deal with physical products with a focus on storage of goods for just in time delivery and consolidation. The virtual storage is represented in a commercial and transportation platform. On the commercial platform products can be sold at any time and place in the world even if they are not physically located in a storage. The transportation platform will take care of consolidation of product flows and the assignment of transport orders to logistics providers. The combination of those two conceptual designs with inclusion of the described trends is expected to be feasible before 2025, however, the implementation in this complex floriculture market will take a lot of effort and trust from all stakeholders.Management of Technology (MoT
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