47,837 research outputs found

    Overview of building simulation in Europe

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    Slides from a presentation which provides and overview of building simulation in Europe

    Phenomenological model of diffuse global and regional atrophy using finite-element methods

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    The main goal of this work is the generation of ground-truth data for the validation of atrophy measurement techniques, commonly used in the study of neurodegenerative diseases such as dementia. Several techniques have been used to measure atrophy in cross-sectional and longitudinal studies, but it is extremely difficult to compare their performance since they have been applied to different patient populations. Furthermore, assessment of performance based on phantom measurements or simple scaled images overestimates these techniques' ability to capture the complexity of neurodegeneration of the human brain. We propose a method for atrophy simulation in structural magnetic resonance (MR) images based on finite-element methods. The method produces cohorts of brain images with known change that is physically and clinically plausible, providing data for objective evaluation of atrophy measurement techniques. Atrophy is simulated in different tissue compartments or in different neuroanatomical structures with a phenomenological model. This model of diffuse global and regional atrophy is based on volumetric measurements such as the brain or the hippocampus, from patients with known disease and guided by clinical knowledge of the relative pathological involvement of regions and tissues. The consequent biomechanical readjustment of structures is modelled using conventional physics-based techniques based on biomechanical tissue properties and simulating plausible tissue deformations with finite-element methods. A thermoelastic model of tissue deformation is employed, controlling the rate of progression of atrophy by means of a set of thermal coefficients, each one corresponding to a different type of tissue. Tissue characterization is performed by means of the meshing of a labelled brain atlas, creating a reference volumetric mesh that will be introduced to a finite-element solver to create the simulated deformations. Preliminary work on the simulation of acquisition artefa- - cts is also presented. Cross-sectional and

    Delivering building simulation information via new communication media

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    Often, the goal of understanding how the building works and the impact of design decisions is hampered by limitations in the presentation of performance data. Contemporary results display is often constrained to what was considered good practice some decades ago rather than in ways that preserve the richness of the underlying data. This paper reviews a framework for building simulation support that addresses these presentation limitations as well as making a start on issues related to distributed team working. The framework uses tools and communication protocols that enable concurrent information sharing and provide a richer set of options for understanding complex performance relationships

    Delivering building simulation information via new communication media

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    Often, the goal of understanding how the building works and the impact of design decisions is hampered by limitations in the presentation of performance data. Contemporary results display is often constrained to what was considered good practice some decades ago rather than in ways that preserve the richness of the underlying data. This paper reviews a framework for building simulation support that addresses these presentation limitations as well as making a start on issues related to distributed team working. The framework uses tools and communication protocols that enable concurrent information sharing and provide a richer set of options for understanding complex performance relationships

    From Blood Oxygenation Level Dependent (BOLD) signals to brain temperature maps

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    A theoretical framework is presented for converting Blood Oxygenation Level Dependent (BOLD) images to temperature maps, based on the idea that disproportional local changes in cerebral blood flow (CBF) as compared with cerebral metabolic rate of oxygen consumption (CMRO2) during functional brain activity, lead to both brain temperature changes and the BOLD effect. Using an oxygen limitation model and a BOLD signal model we obtain a transcendental equation relating CBF and CMRO2 changes with the corresponding BOLD signal, which is solved in terms of the Lambert W function. Inserting this result in the dynamic bio-heat equation describing the rate of temperature changes in the brain, we obtain a non autonomous ordinary differential equation that depends on the BOLD response, which is solved numerically for each brain voxel. In order to test the method, temperature maps obtained from a real BOLD dataset are calculated showing temperature variations in the range: (-0.15, 0.1) which is consistent with experimental results. The method could find potential clinical uses as it is an improvement over conventional methods which require invasive probes and can record only few locations simultaneously. Interestingly, the statistical analysis revealed that significant temperature variations are more localized than BOLD activations. This seems to exclude the use of temperature maps for mapping neuronal activity as areas where it is well known that electrical activity occurs (such as V5 bilaterally) are not activated in the obtained maps. But it also opens questions about the nature of the information processing and the underlying vascular network in visual areas that give rise to this result

    Towards safer mining: the role of modelling software to find missing persons after a mine collapse

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    Purpose. The purpose of the study is to apply science and technology to determine the most likely location of a container in which three miners were trapped after the Lily mine disaster. Following the collapse of the Crown Pillar at Lily Mine in South Africa on the 5th of February 2016, there was a national outcry to find the three miners who were trapped in a surface container lamp room that disappeared in the sinkhole that formed during the surface col-lapse. Methods. At a visit to Lily Mine on the 9th of March, the Witwatersrand Mining Institute suggested a two-way strategy going forward to find the container in which the miners are trapped and buried. The first approach, which is the subject of this paper, is to test temporal 3D modeling software technology to locate the container, and second, to use scientific measurement and testing technologies. The overall methodology used was to first, request academia and research entities within the University to supply the WMI with ideas, which ideas list was compiled as responses came in. These were scrutinized and literature gathered for a conceptual study on which these ideas are likely to work. The software screening and preliminary testing of such software are discussed in this article. Findings. The findings are that software modeling is likely to locate the present position of the container, but accurate data and a combination of different advanced software packages will be required, but at tremendous cost. Originality. This paper presents original work on how software technology can be used to locate missing miners. Practical implications. The two approaches were not likely to recover the miners alive because of the considerable time interval, but will alert the rescue team and mine workers when they come in close proximity to them.Мета. Визначення можливого місця локалізації лампового приміщення контейнера, в якому опинилися три шахтаря після аварії на шахті Лілі (Барбертон, Мпумаланга) методом комп’ютерного моделювання. Після обвалення стельового цілика на шахті Лілі 5 лютого 2016 року почалася національна кампанія з порятунку трьох шахтарів, які залишилися у ламповому приміщенні поверхневого транспортного контейнера, що провалився в утворену після вибуху воронку. Методика. Співробітниками Гірничого Інституту (Уітуотерс) запропонована двостадійна стратегія пошуку контейнера, в якому існує ймовірність знаходження шахтарів. В рамках першого підходу (який розглядається у даній статті) для виявлення контейнера здійснювалось випробування комп’ютерної технології 3D-моделювання в часі. Другий підхід передбачав технологію проведення наукового вимірювання та експерименту. В цілому, методологія включала, насамперед, підключення викладацького та наукового складу університету до вирішення проблеми шляхом комплексної генерації ідей, які були об’єднані в загальний список, вивчені із залученням відповідних літературних джерел, і найбільш реалістичні ідеї були виділені із загального переліку. Дана стаття розглядає результати комп’ютерної експертизи цих ідей та перевірки надійності відповідного програмного забезпечення. Результати. Для зручності моделювання процес обвалення був розділений на три окремі фази: руйнування воронки, руйнування західного схилу та небезпека ковзання на південних схилах. Ідентифіковано програмні технології, які можуть імітувати рух контейнера у перших двох фазах обвалення. В результаті моделювання у програмному забезпеченні ParaView виявлено місце розташування даного контейнера. Виконано аналіз південного схилу за допомогою ArcGIS і складені карти небезпеки схилу для району, а також підземні карти порятунку з маршрутами евакуації. Встановлено, що комп’ютерне моделювання може визначити місцезнаходження контейнера, але для цього потрібні точні вихідні дані й комплекс дорогих високоефективних програмних пакетів. Наукова новизна. Вперше застосовано комплекс комп’ютерних технологій та програмного забезпечення для пошуку зниклих шахтарів після аварійних ситуацій у підземному просторі шахт. Практична значимість. При застосуванні двостадійної стратегії пошуку шахтарів, що опинилися під завалом порід, команда рятувальників отримає сигнал про наближення до їх місцезнаходження.Цель. Определение возможного места локализации лампового помещения контейнера, в котором оказались три шахтера после аварии на шахте Лили (Барбертон, Мпумаланга) методом компьютерного моделирования. После обрушения потолочного целика на шахте Лили 5 февраля 2016 года началась национальная кампания по спасению трех шахтеров, оставшихся в ламповом помещении поверхностного транспортного контейнера, который провалился в воронку, образовавшуюся после взрыва. Методика. Сотрудниками Горного Института (Уитуотерс) предложена двухстадийная стратегия поиска контейнера, в котором существует вероятность нахождения шахтеров. В рамках первого подхода (который рассматривается в данной статье) для обнаружения контейнера производилось испытание компьютерной технологии 3D-моделирования во времени. Второй подход предполагал технологию проведения научного измерения и эксперимента. В целом, методология включала, прежде всего, подключение преподавательского и научного состава университета к решению проблемы путем комплексной генерации идей, которые были объединены в общий список, изучены с привлечением соответствующих литературных источников, и наиболее реалистичные идеи были выделены из общего списка. Настоящая статья рассматривает результаты компьютерной экспертизы данных идей и проверки надежности соответствующего программного обеспечения. Результаты. Для удобства моделирования процесс обрушения был разделен на три отдельные фазы: разрушение воронки, разрушение западного склона и опасность скольжения на южных склонах. Идентифицированы программные технологии, которые могут имитировать движение контейнера в первых двух фазах обрушения. В результате моделирования в программном обеспечении ParaView выявлено местоположение данного контейнера. Выполнен анализа южного склона с помощью ArcGIS и составлены карты опасности склона для района, а также подземные карты спасения с маршрутами эвакуации. Установлено, что компьютерное моделирование может определить местонахождение контейнера, но для этого нужны точные исходные данные и комплекс дорогостоящих высокоэффективных программных пакетов. Научная новизна. Впервые применен комплекс компьютерных технологий и программного обеспечения для поиска пропавших шахтеров после аварийных ситуаций в подземном пространстве шахт. Практическая значимость. При применении двухстадийной стратегии поиска шахтеров, оказавшихся под завалом пород, команда горноспасателей получит сигнал о приближении к их местонахождению.The results of the article were obtained without the support of any of the projects or funding

    On Advanced Mobility Concepts for Intelligent Planetary Surface Exploration

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    Surface exploration by wheeled rovers on Earth's Moon (the two Lunokhods) and Mars (Nasa's Sojourner and the two MERs) have been followed since many years already very suc-cessfully, specifically concerning operations over long time. However, despite of this success, the explored surface area was very small, having in mind a total driving distance of about 8 km (Spirit) and 21 km (Opportunity) over 6 years of operation. Moreover, ESA will send its ExoMars rover in 2018 to Mars, and NASA its MSL rover probably this year. However, all these rovers are lacking sufficient on-board intelligence in order to overcome longer dis-tances, driving much faster and deciding autonomously on path planning for the best trajec-tory to follow. In order to increase the scientific output of a rover mission it seems very nec-essary to explore much larger surface areas reliably in much less time. This is the main driver for a robotics institute to combine mechatronics functionalities to develop an intelligent mo-bile wheeled rover with four or six wheels, and having specific kinematics and locomotion suspension depending on the operational terrain of the rover to operate. DLR's Robotics and Mechatronics Center has a long tradition in developing advanced components in the field of light-weight motion actuation, intelligent and soft manipulation and skilled hands and tools, perception and cognition, and in increasing the autonomy of any kind of mechatronic systems. The whole design is supported and is based upon detailed modeling, optimization, and simula-tion tasks. We have developed efficient software tools to simulate the rover driveability per-formance on various terrain characteristics such as soft sandy and hard rocky terrains as well as on inclined planes, where wheel and grouser geometry plays a dominant role. Moreover, rover optimization is performed to support the best engineering intuitions, that will optimize structural and geometric parameters, compare various kinematics suspension concepts, and make use of realistic cost functions like mass and consumed energy minimization, static sta-bility, and more. For self-localization and safe navigation through unknown terrain we make use of fast 3D stereo algorithms that were successfully used e.g. in unmanned air vehicle ap-plications and on terrestrial mobile systems. The advanced rover design approach is applica-ble for lunar as well as Martian surface exploration purposes. A first mobility concept ap-proach for a lunar vehicle will be presented

    Simulation support for performance assessment of building components

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    The determination of performance metrics for novel building components requires that the tests are conducted in the outdoor environment. It is usually difficult to do this when the components are located in a full-scale building because of the difficulty in controlling the experiments. Test cells allow the components to be tested in realistic, but controlled, conditions. High-quality outdoor experiments and identification analysis methods can be used to determine key parameters that quantify performance. This is important for achieving standardised metrics that characterise the building component of interest, whether it is a passive solar component such as a ventilated window, or an active component such as a hybrid photovoltaic module. However, such testing and analysis does not determine how the building component will perform when placed in a real building in a particular location and climate. For this, it is necessary to model the whole building with and without the building component of interest. A procedure has been developed, and applied within several major European projects, that consists of calibrating a simulation model with high-quality data from the outdoor tests and then applying scaling and replication to one or more buildings and locations to determine performance in practice of building components. This paper sets out the methodology that has been developed and applied in these European projects. A case study is included demonstrating its application to the performance evaluation of hybrid photovoltaic modules

    Climate Responsive Design Simulation and Modelling for Industrial Heritage

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    The control of solar radiation is a basic dimension of modern design in all different types of constructions. Many architects have recently observed that different phases of sustainable design require a set of calculations and simulations that are necessary as a new standard design.'e valuable contributions to the process of sustainable design has a common denominator: solar radiation and comfort. In this way, motivated by all these new strategies and concepts, the large number of papers published suggests that the work has not been finished. 'is work provides an illustration of the Atarazanas regarding its climate responsiveness, focusing specifically on daylighting, shading, heat gain, and cooling loads. 'e objective is to assess the design of the Reales Atarazanas de Sevilla (Seville Royal Dockyards) to quantify how it is impacted by solar insolation and to provide insights about design characteristics that influence efficiency and conservation

    Multiphase procedure for landscape reconstruction and their evolution analysis. GIS modelling for areas exposed to high volcanic risk

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    This paper – focussed on the province of Naples, where many municipalities with a huge demographic and building density are subject to high volcanic risk owing to the presence of the Campi Flegrei (Phlegrean Fields) caldera and the Somma-Vesuvius complex – highlights the methodological-applicative steps leading to the setting up of a multiphase procedure for landscape reconstruction and their evolution analysis. From the operational point of view, the research led to the: (1) digitalisation, georeferencing and comparison of cartographies of different periods of time and recent satellite images; (2) elaboration and publication of a multilayer Story Map; (3) accurate vectorisation of the data of the buildings, for each period of time considered, and the use of kernel density in 2D and 3D; (4) application of the extrusion techniques to the physical aspects and anthropic structures; (5) production of 4D animations and film clips for each period of time considered. A procedure is thus tested made up of preparatory sequences, leading to a GIS modelling aimed at highlighting and quantifying significant problem areas and high exposure situations and at reconstructing the phases which in time have brought about an intense and widespread growth process of the artificial surfaces, considerably altering the features of the landscape and noticeably showing up the risk values. In a context characterised by land use conflicts and anomalous conditions of anthropic congestion, a diagnostic approach through images in 2D, 3D and 4D is used, with the aim to support the prevention and planning of emergencies, process damage scenarios and identify the main intervention orders, raise awareness and educate to risk, making an impact on the collective imagination through the enhancement of specific geotechnological functionalities of great didactic interest
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