4,528 research outputs found

    Maximally Localized States in Quantum Mechanics with a Modified Commutation Relation to All Orders

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    We construct the states of maximal localization taking into account a modification of the commutation relation between position and momentum operators to all orders of the minimum length parameter. To first order, the algebra we use reproduces the one proposed by Kempft, Mangano and Mann. It is emphasized that a minimal length acts as a natural regulator for the theory, thus eliminating the otherwise ever appearing infinities. So, we use our results to calculate the first correction to the Casimir Effect due to the minimal length. We also discuss some of the physical consequences of the existence of a minimal length, culminating in a proposal to reformulate the very concept of "position measurement"

    Guidelines for analysing the building energy efficiency using BIM

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    Introduction The benefits of Building Information Modelling (BIM) for the construction industry are already known and proved. One of the applications of BIM is to estimate buildings energy demand and foster the introduction of more efficient design alternatives. BIM creates information to support designers' decision-making and to allow them to compare and select the best options, enhancing buildings energy efficiency. With the increasing use of BIM and energy simulation tools, there is a need to establish a common and valid procedure for buildings energy assessment. Material and Methods By carrying out a building simulation with BIM, this paper identifies and describes the fundamental stages and requirements to perform a reliable, concise and fast energy assessment. These guidelines will consider Autodesk Revit as a BIM platform to create and prepare the building 3D model. Results The proposed guidelines cover all the required tasks for a BIM energy assessment, as the building modulation details and requirements, the software interoperability modes and restrictions and the comparison and selection of improvement measures. Inputs and advice are given regarding the use of some of the existing energy simulation BIM tools. Conclusions With the increasing number of studies addressing energy simulations with BIM, it is essential to define a set of requisites to precisely perform them. By identifying the minimum requirements and tasks, the proposed guidelines will support future studies in achieving more reliable and comparable results. The possibility to estimate and improve the energy demand of a building during the initial project stages allows for the opportunity to build high performance and more sustainable buildings. BIM capabilities might be an essential support to effectively improve the built environment energy efficiency and accomplish environmental goals.FCT -Fundação para a Ciência e a Tecnologia(SFRH/BD/145735/2019

    A systematic review of the role of BIM in building sustainability assessment methods

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    Building Information Modelling (BIM) is creating new opportunities for the Architecture, Engineering and Construction industry. One of them is the integration of the Building Sustainability Assessment (BSA) during the design process. Currently, an approach for using BIM to foster and optimise the application of BSA methods has not been clearly established yet, creating a knowledge gap on the application of BIM for sustainability assessment purposes. Thus, this paper analyses the current role of BIM to evaluate three BSA methods—LEED, BREEAM and SBTool. The current BIM applicability is assessed by performing a systematic review, where the criteria being assessed and the applied BIM software are identified. A comparison is made to determine which BSA method can currently take more advantage from BIM and to identify the number of assessed criteria from each one. Furthermore, the attractiveness of a BIM-based assessment for SBTool is analysed, facing the actual BIM scenario for LEED and BREEAM. Despite the restrictions, BIM use is increasing for sustainability purposes. Most of the analysed studies and identified software are still focused on the use of LEED for assessing sustainability during the design phase. However, BIM software capabilities can also support the assessment of the other BSA methods so that process replicability can happen. Among the most addressed criteria, the energy and material-related categories are the most eminent. Autodesk Revit is the most-used software. A BIM-based assessment for SBTool will have enough attractiveness. It can assess, at least, the same percentage of criteria as the other schemes, creating new opportunities to enhance building sustainability.This research was funded by the Portuguese Foundation for Science and Technology, grant number SFRH/BD/145735/2019

    Implementation of lean principles for performance improvement: Use of VSM+WID for waste identification

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    This article demonstrates the implementation of lean principles for performance improvement in a manufacturing firm. Value stream mapping and waste identification diagrams (VSM+WID) are integrated to assess the level of currently existing waste and the overall current status of the manufacturing flow. The VSM+WID enables an increase in the awareness of relative waste distribution among different processes in the selected case study manufacturing unit. This manuscript demonstrates how to use VSM+WID to understand the current status of the manufacturing flow related challenges such as: overproduction, work-in-process, inefficient use of man-hours (e.g. unbalanced work distribution), etc. It also demonstrates the effectiveness of visualization of the performance gap between the current and future state. The aforementioned type of performance assessment enables effective identification of waste present in a manufacturing flow in order for future improvement initiatives to be taken.This work has been supported by COMPETE: POCI-01-0145-FEDER-007043 and FCT – Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2013

    BIM-Based method for the verification of building code compliance

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    Urban planning is a valuable tool for growth control and city development, both to maintain the local urban identity and provide life quality for inhabitants. To regulate it, local governments have defined standards for a proper city’s growth through municipal and detailed urban plans. Such instruments identify a set of rules which constructions and buildings must fulfil for a careful and smooth integration within the urban areas. New projects are required to comply with such rules, and designers must adapt and guarantee that their projects fulfil all the local urban requirements. However, the verification process of construction projects is still a manual procedure and often a time-consuming process, with high possibilities for inaccurate measures. Thus, this paper aims to streamline the verification procedure of construction projects’ code compliance to enhance project design efficiency and save designers time. To do so, the Building Information Modelling (BIM) method will be used through the Dynamo programming software. By creating a Dynamo routine to check the building code and urban plan compliance from Brazilian municipalities, specific BIM models will be automatically analysed to detect and evaluate if it is according to local urban legislation. Results have provided a real-time decision support tool, where designers can assess if their buildings are complying with local urban codes at any time of the design stage, making it easy to innovate and integrate innovative design options, as well as to precisely communicate their buildings’ code compliance. Such a method can also support municipality authorities to verify project compliance, reducing assessment and calculation errors, as well as the required time and bureaucracy for project appraisal.This research was funded by the Portuguese Foundation for Science and Technology, through the Regional Operation Programme of North (Grant number SFRH/BD/145735/2019)

    Integrating BIM-Based LCA and Building Sustainability Assessment

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    With the increasing concerns about building environmental impacts, building information modelling (BIM) has been used to perform different kinds of sustainability analysis. Among the most popular are the life cycle assessment (LCA) and building sustainability assessment (BSA). However, the integration of BIM-based LCA in BSA methods has not been adequately explored yet. This study addresses the relation between LCA and BSA within the BIM context for the Portuguese context. By performing an LCA for a Portuguese case study, a set of sustainability criteria from SBTool were simultaneous assessed during the process. The possibility of integrating BIM-based LCA into BSA methods can include more life cycle stages in the sustainability assessment and allow for normalising and producing more comparable results. BIM automates and connects different stages of the design process and provides information for multi-disciplinary data storage. However, there are still some constraints, such as different BSA/LCA databases and the necessity to manually introduce the embodied life cycle impacts of building materials. The scope of the BSA analysis can be expanded by integrating a complete LCA and be fostered by the support of BIM, effectively improving building sustainability according to local standards.Portuguese Foundation for Science and Technology, grant number SFRH/BD/145735/201

    Using BIM for assessing buildings life cycle impacts

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    Facing the recent implementation of the Building Information Modelling (BIM) process in the construction industry, several potentialities have not been fully explored yet. Among them, is the integration of BIM in Life Cycle Assessment (LCA) analysis in order to automate the assessment of the potential environmental impacts. To date, despite the existing studies on the subject, there is still a need to define and establish a recommended assessment framework and software tool for LCA purposes when BIM methodology is used. This research analyses the current state of the implementation of the LCA analysis in the BIM process. Additionally, it compares the results from the use of two LCA software. For this purpose, a case study was modelled in the Autodesk Revit BIM platform and exported to two LCA specific BIM tools: Athena Impact Estimator and Tally. The life cycle impact results from both BIM tools, as well as the required workflows, are discussed and compared in order to validate results and identify the advantages and disadvantages of each. The results show that the implementation of the LCA method can be optimized in time and reliability by using the BIM process. Concerning the selected software, Tally has a better interoperability capability, userfriendly interface and a wider range of possible locations for the building. On the other hand, Athena Impact Estimator requires a detailed building characterisation to perform a comprehensive environmental impact assessment and has a broader materials database.(undefined

    Sistema distribuído de monitorização de consumos e de qualidade de energia elétrica

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    Este artigo descreve a implementação e teste de um sistema distribuído de medição de grandezas elétricas, concebido para utilização com cargas tipicamente existentes nas residências, que possibilita a monitorização remota do consumo e também possui capacidade de deteção de eventos de qualidade de energia elétrica. O sistema é operado pelo utilizador a partir de um computador, através de um programa monitorizador dotado de interface gráfica, que recebe os dados recolhidos por um conjunto de nós sensores ligados às cargas que se deseja monitorizar. A comunicação de dados assenta sobre uma rede de sensores sem fios desenvolvida com base nos protocolos IEEE 802.15.4 e ZigBee. Os nós da rede são baseados no circuito integrado CC2530, da Texas Instruments, que integra um microcontrolador e um transceiver RF num mesmo chip. A implementação do sistema envolveu a concepção e desenvolvimento do hardware dos nós sensores, que efetuam a medição das grandezas elétricas, do software embebido nos nós da rede de sensores sem fios, que gere a aquisição e envio dos dados dos nós sensores até ao computador, e do software monitorizador no computador. Os resultados obtidos nos testes realizados excederam as expetativas iniciais, tendo os erros de medição ficado abaixo do patamar de 1%.Fundação para a Ciência e a Tecnologia (FCT

    Evolución de las actitudes de alumnos ante el aprendizaje del inglés mediante el uso de la pizarra digital interactiva

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    We begin to be aware of the huge change our education has experimented recently as a consequence of the use of some technological resources so common nowadays. This situation has created new teaching-learning processes and roles, causing new pupils’ attitudes toward those subjects that are taught. The present work focuses on the attitudinal changes that several pupils from a school of Badajoz experiment when the Interactive Digital Whiteboard is taken into the English classroom and used as part of an experimental process, developed in three sessions, with different activities such as vocabulary games or recipes. An attitude scale based on the Osgood’s Semantic Differential has been developed in order to adapt it to our sample (8 years old). The results we get from the pretest-postest show an improvement of those pupils’ attitudes toward English, so we can somehow relate the use of this technological tool and a higher interest for the subject studied.Desde hace unos años la educación está experimentando grandes cambios, en gran parte debido a la incorporación de recursos o herramientas tecnológicas presentes en nuestro mundo actual. Esto, sin duda, ha generado cambios en los procesos de enseñanzaaprendizaje, promoviendo, como consecuencia, nuevas actitudes de los alumnos ante las materias. Este trabajo aborda los cambios actitudinales de un grupo de alumnos de un centro educativo de la provincia de Badajoz al introducir la Pizarra Digital Interactiva en el proceso de enseñanza-aprendizaje de la lengua inglesa durante un periodo de tres sesiones, en las que se han desarrollado diferentes actividades. Para la evaluación de estos cambios se ha utilizado una escala de actitudes según el modelo de Diferencial Semántico de Osgood, Succi y Tannenbaum (1957), adaptada a la edad de los alumnos de la muestra, ocho años. Los datos obtenidos, mediante un contraste pretest-postest, muestran una mejoría de las actitudes de dichos alumnos hacia dicha materia, por lo que podemos vincular el uso de este recurso tecnológico con un mayor interés por ella

    BIM-based energy analysis and sustainability assessment - application to Portuguese buildings

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    Buildings are responsible for several negative impacts on the environment, most of them related to nonrenewable energy consumption, increasing the concern regarding buildings energy efficiency. In this context, computer software has been used to estimate the energy needs of the built environment, and the Building Information Modelling (BIM) methodology can be used to simplify this process. This study aims to validate a BIM-based framework to streamline the energy analysis of Portuguese buildings, based on the method of the national regulation for the thermal performance of residential buildings. Currently, designers need to spend considerable time assessing all the building characteristics and performing the mandatory calculations for energy performance analysis. It is also intended to link the results of the energy simulation with a Building Sustainability Assessment method—SBToolPT-H. The purpose is to demonstrate how it is possible to benefit from this approach to simultaneously improve building sustainability during the design stage. To do so, different case studies were modelled in Autodesk Revit and exported to a BIM energy tool to perform energy simulation analysis. The results were validated against the official assessment method of the Portuguese thermal regulation and were successfully used to assess the SBToolPT-H energy efficiency category. The research outcomes provide design teams with a reliable BIM-based framework to improve building energy performance and to develop thermal projects while enhancing building sustainability. It also increases the knowledge about the integration of sustainability assessment in the BIM environment, providing new insights for complete integration.This research was funded by the Portuguese Foundation for Science and Technology through the Regional Operation Programme of North (grant number SFRH/BD/145735/2019)
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