867,363 research outputs found
Construcció programada de polígons i poliedres moleculars i cinc cèntims de les seves aplicacions
En aquest article s'explica com les reaccions d'autoassemblatge (self-assembly) permeten la construcció racional i programada de molts metal·lomacrocicles o espècies discretes amb geometries poligonals o polièdriques. En una segona part, s'expliquen breument algunes de les aplicacions d'aquestes noves supramolècules com són la seva capacitat per a actuar com a anoreactors, catalitzadors, sensors o tamisos moleculars.This paper shows how self-assembly reactions allow the building up of a wide range of metallomacrocycles (polygonal and polyhedral species) in a rational and programmed way. The second part presents a brief survey of some of the applications of these new supramolecules such as cavity-directed synthesis, catalysis, sensing or molecular sieving
Mixed reality application to support building maintenance
This dissertation presents two mixed reality (MR) applications developed for the head-mounted display Microsoft HoloLens (MH) – InOffice and InSitu, which support building maintenance tasks in constructions with complex infrastructure. These solutions are intended to help maintenance workers when they need to track and fix part of the infrastructure by revealing hidden components, displaying additional information and guiding them in complex tasks. The applications have the potential to improve maintenance worker’s performance as they assist in performing faster and with higher accuracy. The work presented explores the creation of the applications and discusses the methodologies used to build user-friendly tools. Both MR applications were tested with active maintenance professionals, and results revealed each solution is useful to support building maintenance in different types of situation. InOffice, which displays an interactive and reduced version of the building being maintained, is suited to work off-site, for planning and remote assistance. In InSitu the user visualizes a 1:1 scaled hologram of the building aligned with the real world, and it is better suited for maintenance that requires manual tasks on site.
The methodology was based on design science research: an improvement need, and not necessarily a problem, was identified, and from there a solution was conceived. MR is being applied as a successful tool for helping in several areas, and this work can give insights for many future solutions with mixed reality or MH to build novel and better applications that improve tasks at work or domestic environments.Esta dissertação apresenta duas aplicações de realidade mista (RM) desenvolvidas para o head-mounted display Microsoft HoloLens (MH) - InOffice e InSitu, as quais auxiliam no desempenho de tarefas de manutenção de edifícios em construções com infraestrutura complexa. Estas soluções destinam-se a ajudar os técnicos de manutenção quando estes precisam de rastrear e consertar parte da infraestrutura, revelando componentes ocultos, exibindo informações adicionais sobre os materiais e orientando-os em tarefas complexas. As aplicações têm potencial para melhorar o desempenho de trabalhadores de manutenção, pois auxiliam na execução mais rápida e com maior precisão do seu trabalho. O trabalho apresentado explora a criação das aplicações e discute as metodologias usadas para criar ferramentas fáceis de usar. Ambas as aplicações de RM foram testadas com profissionais de manutenção no ativo, e os resultados revelaram que cada solução é útil para ajudar na manutenção de edifícios em diferentes tipos de situação. A InOffice, que exibe um modelo interativo e reduzido do edifício a ser mantido, é adequada para trabalhar fora do edifício, para planeamento e assistência remota. Na InSitu, o utilizador visualiza um holograma em escala 1:1 do edifício alinhado com o mundo real e é mais adequada para manutenção que requeira tarefas manuais no próprio local.
A metodologia seguida baseou-se em design science research: uma necessidade de melhoria, e não necessariamente um problema, foi identificada, e a partir daí uma solução foi concebida. A RM tem sido aplicada como uma ferramenta de sucesso para ajudar em várias indústrias, e este trabalho fornece visão e conhecimento para muitas soluções futuras com realidade mista ou com MH que melhorem as tarefas em ambientes profissionais ou até em ambientes domésticos
Auto-Pipe and the X Language: A Toolset and Language for the Simulation, Analysis, and Synthesis of Heterogeneous Pipelined Architectures, Master\u27s Thesis, August 2006
Pipelining an algorithmis a popularmethod of increasing the performance of many computation-intensive applications. Often, one wants to form pipelines composed mostly of commonly used simple building blocks such as DSP components, simple math operations, encryption, or pattern matching stages. Additionally, one may desire to map these processing tasks to different computational resources based on their relative performance attributes (e.g., DSP operations on an FPGA). Auto-Pipe is composed of the X Language, a flexible interface language that aids the description of complex dataflow topologies (including pipelines); X-Com, a compiler for the X Language; X-Sim, a tool for modeling pipelined architectures based on measured, simulated, or derived task and communications behavior; X-Opt, a tool to optimize X applications under various metrics; and X-Dep, a tool for the automatic deployment of X-Com- or X-Sim-generated applications to real or simulated devices. This thesis presents an overview of the Auto-Pipe system, the design and use of the X Language, and an implementation of X-Com. Applications developed using the X Language are presented which demonstrate the effectiveness of describing algorithms using X, and the effectiveness of the Auto-Pipe development flow in analyzing and improving the performance of an application
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Multi-objective optimal design of inerter-based vibration absorbers for earthquake protection of multi-storey building structures
In recent years different inerter - based vibration absorbers (IVAs) emerged for the earthquake protection of building structures coupling viscous and tuned - mass dampers with an inerter device . In the three most popular IVAs the inerter is functioning either as a motion amplifier [tuned - viscous - mass - damper (TVMD) configuration], mass amplifier [tuned - mass - damper - inerter (T MDI) configuration], or mass substitute [tuned - inerter - damper (TID) configuration]. Previous work has shown that through proper tuning , IVAs achieve enhanced earthquake - induced vibration suppression and/or weight reduction compared to conventional dampers/absorbers , but at the expense of increased control forces exerted from the IVA to the host building structure . These potentially large forces are typically not accounted for by current IVA tuning approaches. In this regard, a multi-objective IVA design approach is herein developed to identify the compromise between the competing objectives of (i) suppressing earthquake-induced vibrations in buildings, and (ii) avoiding development of excessive IVA (control) forces, while, simultaneously, assessing the appropriateness of different modeling assumptions for practical design of IVAs for earthquake engineering applications . The potential of the approach to pinpoint Pareto optimal IVA designs against the above objectives is illustrated for different IVA placements along the height of a benchmark 9-storey steel frame structure. Objective (i) is quantified according to current performanc e-based seismic design trends using first-passage reliability criteria associated with the probability of exceeding pre-specified thresholds of storey drifts and/or floor accelerations being the engineering demand parameters (EDPs) of interest . A variant, simpler, formulation is also considered using as performance quantification the sum of EDPs variances in accordance to traditional tuning methods for dynamic vibration absorbers. Objective (ii) is quantified through the variance of the IVA force. It is found that reduction of IVA control force of up to 3 times can be achieved with insignificant deterioration of building performance com pared to the extreme Pareto optimal IVA design targeting maximum vibration suppression , while TID and TMDI a chieve practically the same building performance and significantly outperform the TVMD. Moreover, it is shown that the simpler variant formulation may provide significantly suboptimal reliability performance . Lastly, it is verified that the efficacy of optimal IVA designs for stationary conditions is maintained for non-stationary stochastic excitation model capturing typical evolutionary features of earthquake excitations
Software Architecture for Scalable Applications.
Software has traditionally been built based on a mix of the common architectures. Although several architectural styles have been documented, software developers repetitively solve the problems of scalability and extensibility and deal with the issues of incremental development and interoperability. Component Object Model (COM) is an advanced technology for object-based software development that facilitates interoperability and promotes extensibility. The extensible Markup Language (XML) is the universal format for structured documents and data on the World-Wide-Web (WWW). It describes a class of data objects called XML documents, and partially describes the behavior of the computer programs which process them. This thesis describes how the COM and the XML can be integrated to implement and extend common software architecture styles to address the problems of incremental development and scalability, and shows how the various architecture styles can be modified and how the implementation of certain COM interfaces make the solution scalable and extensible. Issues related to scalability of Web applications have been discussed and architectural solutions used to scale the software have been discussed. Guidelines to building scalable and extensible applications are given and samples to adapt common architectures using COM and XML have been introduced
Expressing Sensor Network Interaction Patterns using Data-driven Macroprogramming
Wireless Sensor Networks (WSNs) are increasingly be- ing employed as a key building block of pervasive com- puting infrastructures, owing to their ability to be embed- ded within the real world. So far, pervasive applications for WSNs have been developed in an ad-hoc manner using node-centric programming models, focusing on the behav- ior of single nodes. Instead, macro-programming models provide much higher levels of abstractions, allowing developers to reason on the sensor network as a whole.
In this paper, we demonstrate how a wide range of interaction patterns commonly found in pervasive, embedded applications can be expressed using ATaG, a data-driven macro-programming language. To support this, we show- case real-world applications developed in ATaG, and con- sider both homogeneous, sense-only scenarios, and hetero- geneous settings involving actuation on the environment un- der control
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