2,663 research outputs found

    Modularisation Strategies for Individualised Precast Construction—Conceptual Fundamentals and Research Directions

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    Modular precast construction is a methodological approach to reduce environmental impacts and increase productivity when building with concrete. Constructions are segmented into similar precast concrete elements, prefabricated with integrated quality control, and assembled just-in-sequence on site. Due to the automatised prefabrication, inaccuracies are minimised and the use of high-performance materials is enabled. As a result, the construction process is accelerated, and the modules can be designed to be lightweight and resource-efficient. This contribution presents the fundamentals of modular constructions made from precast concrete components. Then, to elaborate the requirements of a contemporary modular precast construction, the historic developments are described. Further, concepts and technical processes–comprehensible to non-expert readers–are introduced to formalise the discussion about the current state-of-the-art methods. Three case studies treating ongoing research are introduced and related to the conceptual fundamentals. The research is evaluated with regard to current barriers and future directions. In conclusion, modular precast construction is able to reduce emissions and increase productivity in the sector if researchers and firms coordinate the development of suitable technologies that bring value to critical stakeholders

    Computational Tools and Facilities for the Next-Generation Analysis and Design Environment

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    This document contains presentations from the joint UVA/NASA Workshop on Computational Tools and Facilities for the Next-Generation Analysis and Design Environment held at the Virginia Consortium of Engineering and Science Universities in Hampton, Virginia on September 17-18, 1996. The presentations focused on the computational tools and facilities for analysis and design of engineering systems, including, real-time simulations, immersive systems, collaborative engineering environment, Web-based tools and interactive media for technical training. Workshop attendees represented NASA, commercial software developers, the aerospace industry, government labs, and academia. The workshop objectives were to assess the level of maturity of a number of computational tools and facilities and their potential for application to the next-generation integrated design environment

    Algorithms for Geometric Optimization and Enrichment in Industrialized Building Construction

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    The burgeoning use of industrialized building construction, coupled with advances in digital technologies, is unlocking new opportunities to improve the status quo of construction projects being over-budget, delayed and having undesirable quality. Yet there are still several objective barriers that need to be overcome in order to fully realize the full potential of these innovations. Analysis of literature and examples from industry reveal the following notable barriers: (1) geometric optimization methods need to be developed for the stricter dimensional requirements in industrialized construction, (2) methods are needed to preserve model semantics during the process of generating an updated as-built model, (3) semantic enrichment methods are required for the end-of-life stage of industrialized buildings, and (4) there is a need to develop pragmatic approaches for algorithms to ensure they achieve required computational efficiency. The common thread across these examples is the need for developing algorithms to optimize and enrich geometric models. To date, a comprehensive approach paired with pragmatic solutions remains elusive. This research fills this gap by presenting a new approach for algorithm development along with pragmatic implementations for the industrialized building construction sector. Computational algorithms are effective for driving the design, analysis, and optimization of geometric models. As such, this thesis develops new computational algorithms for design, fabrication and assembly, onsite construction, and end-of-life stages of industrialized buildings. A common theme throughout this work is the development and comparison of varied algorithmic approaches (i.e., exact vs. approximate solutions) to see which is optimal for a given process. This is implemented in the following ways. First, a probabilistic method is used to simulate the accumulation of dimensional tolerances in order to optimize geometric models during design. Second, a series of exact and approximate algorithms are used to optimize the topology of 2D panelized assemblies to minimize material use during fabrication and assembly. Third, a new approach to automatically update geometric models is developed whereby initial model semantics are preserved during the process of generating an as-built model. Finally, a series of algorithms are developed to semantically enrich geometric models to enable industrialized buildings to be disassembled and reused. The developments made in this research form a rational and pragmatic approach to addressing the existing challenges faced in industrialized building construction. Such developments are shown not only to be effective in improving the status quo in the industry (i.e., improving cost, reducing project duration, and improving quality), but also for facilitating continuous innovation in construction. By way of assessing the potential impact of this work, the proposed algorithms can reduce rework risk during fabrication and assembly (65% rework reduction in the case study for the new tolerance simulation algorithm), reduce waste during manufacturing (11% waste reduction in the case study for the new panel unfolding and nesting algorithms), improve accuracy and automation of as-built model generation (model error reduction from 50.4 mm to 5.7 mm in the case study for the new parametric BIM updating algorithms), reduce lifecycle cost for adapting industrialized buildings (15% reduction in capital costs in the computational building configurator) and reducing lifecycle impacts for reusing structural systems from industrialized buildings (between 54% to 95% reduction in average lifecycle impacts for the approach illustrated in Appendix B). From a computational standpoint, the novelty of the algorithms developed in this research can be described as follows. Complex geometric processes can be codified solely on the innate properties of geometry – that is, by parameterizing geometry and using methods such as combinatorial optimization, topology can be optimized and semantics can be automatically enriched for building assemblies. Employing the use of functional discretization (whereby continuous variable domains are converted into discrete variable domains) is shown to be highly effective for complex geometric optimization approaches. Finally, the algorithms encapsulate and balance the benefits posed by both parametric and non-parametric schemas, resulting in the ability to achieve both high representational accuracy and semantically rich information (which has previously not been achieved or demonstrated). In summary, this thesis makes several key improvements to industrialized building construction. One of the key findings is that rather than pre-emptively determining the best suited algorithm for a given process or problem, it is often more pragmatic to derive both an exact and approximate solution and then decide which is optimal to use for a given process. Generally, most tasks related to optimizing or enriching geometric models is best solved using approximate methods. To this end, this research presents a series of key techniques that can be followed to improve the temporal performance of algorithms. The new approach for developing computational algorithms and the pragmatic demonstrations for geometric optimization and enrichment are expected to bring the industry forward and solve many of the current barriers it faces

    Effects of Schisandrin B on Rod Photoreceptors in the pde6c Larval Retina

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    Current Rapid prototyping tools although reduce development time, they still have several restrictions such as print volume and print times. Through this thesis, two prototyping kits are proposed, a rod connector based, user controlled computational support system that re-purposes surface models and transforms them into structurally scaffolded constructs with movable joints; and a planar connector based system that implements movable joints to create functional prototypes. The rod based system enables users to interactively personalize scaffolded structures by re-purposing existing surface mesh models; analyze scaffolded constructs in-situ for better structurality, add movable joints to increase functionality, and attach personalized appearances to the scaffolding for increased customization.vThe planar connector system uses movable and electronic embedded connectors to functionalize planar surfaces to create multi-fidelity prototypes capable of interacting with the environment

    The Parametric Facade: Optimization in Architecture through a Synthesis of Design, Analysis and Fabrication

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    Modular building systems that use only prefabricated parts, sometimes known as building “kits”, first emerged in the 1830s and 1840s in the form of glass and iron roof systems for urban transportation and distribution centers and multi-storey facade systems. Kit systems are still used widely today in the form of curtain wall assemblies for office and condominium towers, yet in all this time the formal flexibility of these systems (their ability to form complex shapes) has not increased greatly. This is in large part due to the fact that the systems still rely on mass-produced components. This lack of flexibility limits the degree to which these systems can be customized for particular contexts and optimized for such things as daylighting or energy efficiency. Digital design and fabrication tools now allow us to create highly flexible building facade systems that can be customized for different contexts as well as optimized for particular performance objectives. This thesis develops a prototype for a flexible facade system using parametric modeling tools. The first part of the thesis looks at how parametric modeling can be used to facilitate building customization and optimization by integrating the acts of design, analysis, fabrication and construction. The second part of the thesis presents the facade system prototype and documents key aspects of its development. The facade system is modeled in Grasshopper 3D, a parametric modeling plug-in for Rhinoceros 3D. The model has built-in analysis tools to help the user optimize the facade for daylighting, energy efficiency, or views within any given context, as well as tools that alert the designer when fabrication or construction constraints are being violated

    A Framework Using Tangible Interaction for Automatically Capturing and Embedding Design Intent in Parametric Models

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    The objective of this research is to address some of the challenges of parametric design associated with defining a model’s frameworks using mathematics and computer programming. This work proposes a tactile-based approach to automate the generation of such information. A design-based research method is implemented for this work, which involves developing research prototypes consisting of Tangible User-Interfaces (TUIs) to demonstrate and test the digital-physical workflow. Five prototypes were created each generating a type of information for setting up parametric models, including; linear and polynomial mathematical equations, algorithmic rules and seed configurations for a Cellular Automata (CA) component, geometric transformations (single and compound), and Non-Uniform Rational Basis Spline (NURBS) objects. During the progress of the work, prototypes were improved to include a higher level of automation by performing multiple and more complex modeling tasks. This research includes two levels of evaluation. The first is system correctness, which tests the prototypes for translating tangible interaction with design objects into modeling information. The second is a qualitative comparison between the developed method and the conventional parametric modeling approach using graph-based and/or text-based programming applications. The results of the research have shown the plausibility of the workflow and its potential benefits for parametric modeling practice and education. This work provides a proof-of-concept for a novel approach that translates design intents into mathematical and algorithmic modeling information for establishing parametric frameworks. The outcomes of this research include; detailed workflows describing algorithmic procedures for interpreting analog data, TUI specifications, and an overall theoretical framework of the method

    Computational Thinking in Education: Where does it fit? A systematic literary review

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    Computational Thinking (CT) has been described as an essential skill which everyone should learn and can therefore include in their skill set. Seymour Papert is credited as concretising Computational Thinking in 1980 but since Wing popularised the term in 2006 and brought it to the international community's attention, more and more research has been conducted on CT in education. The aim of this systematic literary review is to give educators and education researchers an overview of what work has been carried out in the domain, as well as potential gaps and opportunities that still exist. Overall it was found in this review that, although there is a lot of work currently being done around the world in many different educational contexts, the work relating to CT is still in its infancy. Along with the need to create an agreed-upon definition of CT lots of countries are still in the process of, or have not yet started, introducing CT into curriculums in all levels of education. It was also found that Computer Science/Computing, which could be the most obvious place to teach CT, has yet to become a mainstream subject in some countries, although this is improving. Of encouragement to educators is the wealth of tools and resources being developed to help teach CT as well as more and more work relating to curriculum development. For those teachers looking to incorporate CT into their schools or classes then there are bountiful options which include programming, hands-on exercises and more. The need for more detailed lesson plans and curriculum structure however, is something that could be of benefit to teachers

    Theoretical Engineering and Satellite Comlink of a PTVD-SHAM System

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    This paper focuses on super helical memory system's design, 'Engineering, Architectural and Satellite Communications' as a theoretical approach of an invention-model to 'store time-data'. The current release entails three concepts: 1- an in-depth theoretical physics engineering of the chip including its, 2- architectural concept based on VLSI methods, and 3- the time-data versus data-time algorithm. The 'Parallel Time Varying & Data Super-helical Access Memory' (PTVD-SHAM), possesses a waterfall effect in its architecture dealing with the process of voltage output-switch into diverse logic and quantum states described as 'Boolean logic & image-logic', respectively. Quantum dot computational methods are explained by utilizing coiled carbon nanotubes (CCNTs) and CNT field effect transistors (CNFETs) in the chip's architecture. Quantum confinement, categorized quantum well substrate, and B-field flux involvements are discussed in theory. Multi-access of coherent sequences of 'qubit addressing' in any magnitude, gained as pre-defined, here e.g., the 'big O notation' asymptotically confined into singularity while possessing a magnitude of 'infinity' for the orientation of array displacement. Gaussian curvature of k(k<0) is debated in aim of specifying the 2D electron gas characteristics, data storage system for defining short and long time cycles for different CCNT diameters where space-time continuum is folded by chance for the particle. Precise pre/post data timing for, e.g., seismic waves before earthquake mantle-reach event occurrence, including time varying self-clocking devices in diverse geographic locations for radar systems is illustrated in the Subsections of the paper. The theoretical fabrication process, electromigration between chip's components is discussed as well.Comment: 50 pages, 10 figures (3 multi-figures), 2 tables. v.1: 1 postulate entailing hypothetical ideas, design and model on future technological advances of PTVD-SHAM. The results of the previous paper [arXiv:0707.1151v6], are extended in order to prove some introductory conjectures in theoretical engineering advanced to architectural analysi

    Tangible user interfaces : past, present and future directions

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    In the last two decades, Tangible User Interfaces (TUIs) have emerged as a new interface type that interlinks the digital and physical worlds. Drawing upon users' knowledge and skills of interaction with the real non-digital world, TUIs show a potential to enhance the way in which people interact with and leverage digital information. However, TUI research is still in its infancy and extensive research is required in or- der to fully understand the implications of tangible user interfaces, to develop technologies that further bridge the digital and the physical, and to guide TUI design with empirical knowledge. This paper examines the existing body of work on Tangible User In- terfaces. We start by sketching the history of tangible user interfaces, examining the intellectual origins of this field. We then present TUIs in a broader context, survey application domains, and review frame- works and taxonomies. We also discuss conceptual foundations of TUIs including perspectives from cognitive sciences, phycology, and philoso- phy. Methods and technologies for designing, building, and evaluating TUIs are also addressed. Finally, we discuss the strengths and limita- tions of TUIs and chart directions for future research

    Shape-changing architectural skins: a review on materials, design and fabrication strategies and performance analysis

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    In recent years, there has been an increasing interest in shape-changing smart materials in design fields. The ability to design responsive architectures that adapt to different climatic conditions is, without doubt, an appealing idea. One area in which shape-changing materials are applied is in the design of building skins or envelopes. This paper presents a systematic review of the literature on the use of shape-changing materials in the development of active skin systems, identifying patterns in design and manufacturing strategies. We also note the stage of development of the proposed designs and whether performance analysis was conducted to predict their behaviour. The results show that the most commonly used materials are SMA (Shape Memory Alloys) and wood-based bio-composites. Other shape-changing materials used for developing skin systems are, in order of popularity, thermo bimetals, electroactive polymers, composite bimetals, shape memory polymers, and hydrogels. The patterns identified among the studies are (1) design strategies: smart material as the skin, smart material as the actuator, combination with other non-responsive materials, responsive structures, geometric amplification; and (2) manufacturing strategies: bilayer systems and additive manufacturing.&nbsp;&nbsp; Finally, while the argument for the development of responsive skin systems is often based on the idea of efficiency and improved performance, we found that few studies can predict the performance of such skin systems
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