78 research outputs found

    Improving Compute & Data Efficiency of Flexible Architectures

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    Regular Hierarchical Surface Models: A conceptual model of scale variation in a GIS and its application to hydrological geomorphometry

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    Environmental and geographical process models inevitably involve parameters that vary spatially. One example is hydrological modelling, where parameters derived from the shape of the ground such as flow direction and flow accumulation are used to describe the spatial complexity of drainage networks. One way of handling such parameters is by using a Digital Elevation Model (DEM), such modelling is the basis of the science of geomorphometry. A frequently ignored but inescapable challenge when modellers work with DEMs is the effect of scale and geometry on the model outputs. Many parameters vary with scale as much as they vary with position. Modelling variability with scale is necessary to simplify and generalise surfaces, and desirable to accurately reconcile model components that are measured at different scales. This thesis develops a surface model that is optimised to represent scale in environmental models. A Regular Hierarchical Surface Model (RHSM) is developed that employs a regular tessellation of space and scale that forms a self-similar regular hierarchy, and incorporates Level Of Detail (LOD) ideas from computer graphics. Following convention from systems science, the proposed model is described in its conceptual, mathematical, and computational forms. The RHSM development was informed by a categorisation of Geographical Information Science (GISc) surfaces within a cohesive framework of geometry, structure, interpolation, and data model. The positioning of the RHSM within this broader framework made it easier to adapt algorithms designed for other surface models to conform to the new model. The RHSM has an implicit data model that utilises a variation of Middleton and Sivaswamy (2001)’s intrinsically hierarchical Hexagonal Image Processing referencing system, which is here generalised for rectangular and triangular geometries. The RHSM provides a simple framework to form a pyramid of coarser values in a process characterised as a scaling function. In addition, variable density realisations of the hierarchical representation can be generated by defining an error value and decision rule to select the coarsest appropriate scale for a given region to satisfy the modeller’s intentions. The RHSM is assessed using adaptions of the geomorphometric algorithms flow direction and flow accumulation. The effects of scale and geometry on the anistropy and accuracy of model results are analysed on dispersive and concentrative cones, and Light Detection And Ranging (LiDAR) derived surfaces of the urban area of Dunedin, New Zealand. The RHSM modelling process revealed aspects of the algorithms not obvious within a single geometry, such as, the influence of node geometry on flow direction results, and a conceptual weakness of flow accumulation algorithms on dispersive surfaces that causes asymmetrical results. In addition, comparison of algorithm behaviour between geometries undermined the hypothesis that variance of cell cross section with direction is important for conversion of cell accumulations to point values. The ability to analyse algorithms for scale and geometry and adapt algorithms within a cohesive conceptual framework offers deeper insight into algorithm behaviour than previously achieved. The deconstruction of algorithms into geometry neutral forms and the application of scaling functions are important contributions to the understanding of spatial parameters within GISc

    The nature of growth in the biofuel feedstock and bloom-forming green macroalga Ulva

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    Ulva is a genus of multicellular green algae that is phylogenetically similar to uni- cellular green algae such as Chlamydomonas and Ostreococcus. Ulva is present in much of the coastal benthic zones worldwide, and is of great interest for three main reasons. Firstly, Ulva is an important feedstock for biofuels. Secondly, many Ulva species are massively proliferating organisms that cause Harmful Algal Blooms, which are ecologically devastating. Finally, Ulva is an important model organism that could elucidate the evolution of multicellularity. This thesis investigates the physiology of growth in Ulva in four sequential results chapters. The first establishes a statistical proof for the goodness of fit of gene family occupancy data to a discrete power law model. This was an assumption used in the only Ulva genome study, which found no genomic signature for multicellularity. This establishes the baseline for the in- vestigation of bottom-up morphogenesis in Ulva. The second is the investigation of differential growth, by identifying cell tessellation patterns in different morphologies of Ulva thalli, namely the “ribbon” and “leaf” morphotypes, with mathematical mod- els using Voronoi tessellations. The third expands investigates differential growth in the ribbon and leaf morphotypes with a focus on identifying potential mechanisms with further mathematical models using Centroidal Voronoi Tessellations. The fourth aims to develop experimental techniques to confirm the hypotheses arising from the mathematical modelling in the second and third chapters. The first part involves the use of EdU cellular proliferation assays. The remainder of the chapter will investigate the development of a live-imaging biomass monitoring system that aims to improve the accuracy, reliability and temporal resolution of aquatic biomass measurements. It can be concluded that Ulva does not show a genomic signature for multicellularity, and bottom-up mechanisms likely explain its morphogenesis and morphologies

    Exploring city spaces : an exploration into mapping practices and rule based design

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    This paper has been written in 3 sections. With some adjustments, the first section is largely the theory paper, the second my technology paper, and the third an exploration of my design. These three sections have been written as disparate parts. Ideas and themes are carried through the three papers, but they do not read as a coherent whole. This year has been a journey into the city of Cape Town; an exploration of its complexity, vibrant city spaces and everyday life. This is essentially what this paper is about, and is a theme that is explored in all three sections in different ways- with the third drawing and building on the first two. I started with ideas of Lefebvre and the work of CHORA as a methodology for exploring the 'everyday practices' in the city- and moved through this to an engagement with rule based design and algorithmic architecture. The design chapter loops back to the beginning of the paper, and draws from and is informed by both the initial research, a'1d rule- based methodology. All three of these sections have been exploratory processes engaging with this set of ideas around complexity within the city. I do not see them as providing an answer as to how to design or explore cities, but rather as an attempt to engage with these very real questions. They are a series of ideas that have enabled me to see parts of the 'hidden world' within Cape Town, and explore this through ideas of the unknown and unimaginable in architecture

    Development of Novel Nano Platforms and Machine Learning Approaches for Raman Spectroscopy

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    In Raman spectroscopy, data analysis occupies a large amount of time and effort; thus, it is paramount to have the proper tools to extract the most meaning from the Raman analysis. This thesis explores improved ways to analyse Raman data mostly by using machine learning techniques available in Python. The substrate used throughout this thesis has been patterned through an electrohydrodynamic process that patterns micrometric pillars onto the substrate, which, after being gold coated, can generate surface-enhanced Raman scattering. An initial theoretical background was laid for the electrohydrodynamic process and additional observations regarding the fluid mechanics. Furthermore, when the structures are fabricated, and Raman measurements are taken, we show that it is possible to create an effective convolutional neural networks that systematically evaluate these patterns’ surface morphology and extracts features responsible for the surface-enhanced Raman scattering phenomenon. Being able to predict 90% of the time from optical microscope images and 99% of the time with atomic force microscopy images Additionally, a thorough machine learning analysis of the Raman literature was done. The best machine learning algorithms were put together into a script combined with a graphical user Interface that can run multiple commands such as principal component analysis and self-organizing maps, all in a centralised way. This way, we managed to consistently extract information from Raman and surface-enhanced Raman scattering spectra to open possibilities for precise peak analysis methods using a multi-Lorentzian fit algorithm

    Modelling and Simulation for Power Distribution Grids of 3D Tiled Computing Arrays

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    This thesis presents modelling and simulation developments for power distribution grids of 3D tiled computing arrays (TCAs), a novel type of paradigm for HPC systems, and tests the feasibility of such systems for HPC systems domains. The exploration of a complex power-grid such as those found in the TCA concept requires detailed simulations of systems with hundreds and possibly thousands of modular nodes, each contributing to the collective behaviour of the system. In particular power, voltage, and current behaviours are critically important observations. To facilitate this investigation, and test the hypothesis, which seeks to understand if scalability is feasible for such systems, a bespoke simulation platform has been developed, and (importantly) validated against hardware prototypes of small systems. A number of systems are simulated, including systems consisting of arrays of ’balls’. Balls are collections of modular tiles that form a ball-like modular unit, and can then themselves be tiled into large scale systems. Evaluations typically involved simulation of cubic arrays of sizes ranging from 2x2x2 balls up to 10x10x10. Larger systems require extended simulation times. Therefore models are developed to extrapolate system behaviours for higher-orders of systems and to gauge the ultimate scalability of such TCA systems. It is found that systems of 40x40x40 are quite feasible with appropriate configurations. Data connectivity is explored to a lesser degree, but comparisons were made between TCA systems and well known comparable HPC systems, and it is concluded that TCA systems can be built with comparable data-flow and scalability, and that the electrical and engineering challenges associated with the novelty of 3D tiled systems can be met with practical solutions

    Interactive volume ray tracing

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    Die Visualisierung von volumetrischen Daten ist eine der interessantesten, aber sicherlich auch schwierigsten Anwendungsgebiete innerhalb der wissenschaftlichen Visualisierung. Im Gegensatz zu Oberflächenmodellen, repräsentieren solche Daten ein semi-transparentes Medium in einem 3D-Feld. Anwendungen reichen von medizinischen Untersuchungen, Simulation physikalischer Prozesse bis hin zur visuellen Kunst. Viele dieser Anwendungen verlangen Interaktivität hinsichtlich Darstellungs- und Visualisierungsparameter. Der Ray-Tracing- (Stahlverfolgungs-) Algorithmus wurde dabei, obwohl er inhärent die Interaktion mit einem solchen Medium simulieren kann, immer als zu langsam angesehen. Die meisten Forscher konzentrierten sich vielmehr auf Rasterisierungsansätze, da diese besser für Grafikkarten geeignet sind. Dabei leiden diese Ansätze entweder unter einer ungenügenden Qualität respektive Flexibilität. Die andere Alternative besteht darin, den Ray-Tracing-Algorithmus so zu beschleunigen, dass er sinnvoll für Visualisierungsanwendungen benutzt werden kann. Seit der Verfügbarkeit moderner Grafikkarten hat die Forschung auf diesem Gebiet nachgelassen, obwohl selbst moderne GPUs immer noch Limitierungen, wie beispielsweise der begrenzte Grafikkartenspeicher oder das umständliche Programmiermodell, enthalten. Die beiden in dieser Arbeit vorgestellten Methoden sind deshalb vollständig softwarebasiert, da es sinnvoller erscheint, möglichst viele Optimierungen in Software zu realisieren, bevor eine Portierung auf Hardware erfolgt. Die erste Methode wird impliziter Kd-Baum genannt, eine hierarchische und räumliche Beschleunigungstruktur, die ursprünglich für die Generierung von Isoflächen reguläre Gitterdatensätze entwickelt wurde. In der Zwischenzeit unterstützt sie auch die semi-transparente Darstellung, die Darstellung von zeitabhängigen Datensätzen und wurde erfolgreich für andere Anwendungen eingesetzt. Der zweite Algorithmus benutzt so genannte Plücker-Koordinaten, welche die Implementierung eines schnellen inkrementellen Traversierers für Datensätze erlauben, deren Primitive Tetraeder beziehungsweise Hexaeder sind. Beide Algorithmen wurden wesentlich optimiert, um eine interaktive Bildgenerierung volumetrischer Daten zu ermöglichen und stellen deshalb einen wichtigen Beitrag hin zu einem flexiblen und interaktiven Volumen-Ray-Tracing-System dar.Volume rendering is one of the most demanding and interesting topics among scientific visualization. Applications include medical examinations, simulation of physical processes, and visual art. Most of these applications demand interactivity with respect to the viewing and visualization parameters. The ray tracing algorithm, although inherently simulating light interaction with participating media, was always considered too slow. Instead, most researchers followed object-order algorithms better suited for graphics adapters, although such approaches often suffer either from low quality or lack of flexibility. Another alternative is to speed up the ray tracing algorithm to make it competitive for volumetric visualization tasks. Since the advent of modern graphic adapters, research in this area had somehow ceased, although some limitations of GPUs, e.g. limited graphics board memory and tedious programming model, are still a problem. The two methods discussed in this thesis are therefore purely software-based since it is believed that software implementations allow for a far better optimization process before porting algorithms to hardware. The first method is called implicit kd-tree, which is a hierarchical spatial acceleration structure originally developed for iso-surface rendering of regular data sets that now supports semi-transparent rendering, time-dependent data visualization, and is even used in non volume-rendering applications. The second algorithm uses so-called Plücker coordinates, providing a fast incremental traversal for data sets consisting of tetrahedral or hexahedral primitives. Both algorithms are highly optimized to support interactive rendering of volumetric data sets and are therefore major contributions towards a flexible and interactive volume ray tracing framework

    Impact Of Parametric Design On Designing Performative Facades

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    Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2015Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2015En yalın tanımıyla, mimarlık insanı dış çevreden gelen etkenlerden korumaktır. Yüzyıllar boyunca, mimarlık teknolojı, malzeme yenilikleri, stil, mekan organizasyonu ve diğer konularda gelişerek başarılı bir yol kat etmiştır. İlk dijıtal modelleme programları mimarların yeni formları algılamalarına yardımcı oluyordu. Bugün yeni nesil dijital teknikleri mimarlara yaratıkları formları algılama ve kontrol etme imkanını da sağlamaktadır. Bugün yapı sektörü, dünyanın en yüksek enerji tuketimi olan sektörlerden bırıdır. Dolayısıyla enerji korunumu bugün kaçınılmaz olarak en önemli konuların başında gelmelidir. Dijital teknikler gelişmiş ve standard dışı formların tasarımı ve üretimi konusunda oldukça önemli katkılar sağlamaktadır. Bu nedenle performansa dayalı tasarım için yeni yollar ortaya çıkmaktadır. Parametrik tasarım, mimarlığın yeni bir metodu olarak, bılgısayar ortamında, algoritmalara dayalı tasarımda oldukça önemli bir noktaya gelmiştir. Parametrik tasarım dolayısıyla performansa dayalı tasarım alanında da etkin olarak kullanılabilir. Bina performansı, akustik ve enerji verimliğini kapsamaktadır. Parametrik modeller,  performansa dayalı tasarım karar ve kısıtlama programlama faktörlerine oldulça etkin bir şekilde yanıt verebilmektedir. Matematiksel tasarım ve simülasyon uygulamalarınin gelişimi, ceryanda olan tasarımın gelistirir. Bina simülasyon uygulamalarının, tasarım seçenekleri ve bina genel performansının incelenmesine yardımcı olmaktadır. Simülasyon uygulamaları, enerji odaklı binaların tasrımı için ayrılmaz bir parçadır. Cepheler bir yapının enerji tüketimi ve konfor parametreleri konusunda çok önemli bir bileşeni olduğundan cephe tasarımı, kuşkuz tüm mimariden ayrılmayacak şekilde, çok önemli bir yere sahiptir. Özellikle bu çalışma bağlamında, dinamik cephe tasarımlarının çeşitli koşullara yanıt verme konusunda sahip olduklari esneklik nedeniyle yapının enerji performansını yükseltme ve enerji tasarrufu konularında çok daha etkin oldukları savunulmaktadır.  Bu çalışmada mevcut bilgi ve daha önce yapılmış çalışmalar dikkate alınarak parametrik tasarım metodu ile esnek-adaptif bir cephe tasarlama deneyimi gerçekleştirilmiştir.  Bu tasarımda araştırmaları ele alarak, parametrik tasrım ile bir esnek-adaptıf cephe sistemi tasarlanıp, aydınlatma analizi yapılacaktır. Bu tasarımda gün ışığına karşı bina performansı incelenmiştir. Tezin ilk bölümünde, dijital tasarım ve bilgisayarın mimarlıkta olan önem ve etkisi ve bunun sonüçlarından biri olarak özelleştirilmiş tasarımı anlatılmıştır. Sonra ise,  tasarım ve üretimin mimarlık tasarlama ve üretim aşamalarındaki önemi ve etkisi üzerinde durulmuş, devamında performansa dayalı tasarım ve bu alanda parametrik tasarlama metodunu olasılı etlileri tartışılmıştır. İkinci bölümde parametrik tasarlama yönetmeleri kullanilarak tasarlanmış performansa dayalı cephe tasarım örnekleri analitik bir bakış açısıyla anlatılmıştır. Son bölümde ise varolan ve halihazırda kullanılmakta olan İTÜ Maslak yerleşkesinde yeralan Teknokent binasının cephesi için gün ışığı performansına dayalı bir cephe tasarım denemesi gerçekleştirilmiştir.In a simple definition, architecture was aimed to inhabit human inside a space that covers him from wild extreme environmental conditions. During the centuries, it developed and achieved higher levels of complexity and advancements in technology, space organization, style, material assembly and so on. If the first generation of digital modeling programs allowed designers to conceive new forms, a new breed of digital techniques is today discussed for their ability to allow these forms to be controlled and realized. Building is considered as one of the largest energy consuming sectors in most countries and nowadays energy consumption is an important issue in architecture. With the advent of digital technologies and the ability to conceptualize, express and produce complex forms and non-standard buildings the novel direction for supporting performance-based design are beginning to emerge. Parametric design as a new method in architecture for intelligently designing architectural objects based on relationships and rules using the computer, can help for achieving performance-based design. It allows designing complex forms but, it is not just to make buildings more visually compelling but to precisely tune nearly every aspect of their performance, from acoustics to energy efficiency, so the system can be used as a performance-driven process. The parametric models can combine and respond simultaneously to design and its programmatic factors, such as performance design-decisions, and constraints. Development in computational design and simulation applications are providing methods to improve current design practices, since the uncertainties about various design elements can be simulated and studied from the design inception. Building performance simulations aid in investigating design options and the overall building performance and are an integral part of the design process for energy efficient and high-performance buildings.  Since the façade is one of the most significant contributions to the energy budget as well as the comfort parameters, it is important to focus more on it. By making the facades more dynamically responsive to the environmental conditions they can fit better to the various conditions and therefore supply better comfort for the occupants. Digital design and fabrication tools now allow us to create highly flexible-adaptive building façade systems that can be customized for different con-texts. Having stated current knowledge and previous researches in mind in this thesis, a prototype of an adaptive façade system using parametric modeling tools is going to be designed and analyzed it, so as to evaluate the performance of that façade response to the day-lighting. The first part of the thesis looks at the importance of digital design and computer in architecture and issue of mass customization as one of its results. Afterwards, the importance of performance-based design is mentioned and the significant role of parametric design as one of the methods to achieve this kind of design is analyzed. The second part of the thesis focuses on the façade systems and analyzes some examples of performance-driven designs using parametric modeling. The last section explained the process of development of adaptive building façade, using parametric design, for the chosen building with considering the day-lighting performance and then analyze the illuminance level of building before and after the implementing the designed facade to compare whether if with implementing the facade can we achieve the optimal illuminance level and to prevent the direct sun exposures or not.Yüksek LisansM.Sc
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