DESIGN-BUILD: AN EFFECTIVE APPROACH FOR ARCHITECTURE STUDIO EDUCATION

2018 ◽  
Vol 12 (2) ◽  
pp. 146 ◽  
Author(s):  
Nabil Mohareb ◽  
Sara Maassarani
Keyword(s):  
Material Selection ◽  
Environmental Constraints ◽  
Design Project ◽  
Construction Methods ◽  
Physical Scale ◽  
Design Build ◽  
Simulation Results ◽  
Education Process ◽  
Real Target

Current architecture studios are missing an important phase in the education process, which is constructing the students’ conceptual ideas on a real physical scale. The design-build approach enables the students to test their ideas, theories, material selection, construction methods, environmental constraints, simulation results, level of space functionality and other important aspects when used by real target clients in an existing context. This paper aims to highlight the importance of using the design-build method through discussing a design project case study carried out by the Masters of Architecture design programme students at Beirut Arab University, who have built prototype units for refugees on a 1:1 scale.

scholarly journals Extended and Unscented Kalman Filtering Applied to a Flexible-Joint Robot with Jerk Estimation

2010 ◽  
Vol 2010 ◽  
pp. 1-14 ◽  
Author(s):  
Mohammad Ali Badamchizadeh ◽  
Iraj Hassanzadeh ◽  
Mehdi Abedinpour Fallah
Keyword(s):  
Initial Conditions ◽  
Covariance Matrices ◽  
Flexible Joints ◽  
Velocity Measurements ◽  
Lagrange Equations ◽  
Robust Nonlinear Control ◽  
Flexible Joint ◽  
Flexible Joint Robots ◽  
Simulation Results

Robust nonlinear control of flexible-joint robots requires that the link position, velocity, acceleration, and jerk be available. In this paper, we derive the dynamic model of a nonlinear flexible-joint robot based on the governing Euler-Lagrange equations and propose extended and unscented Kalman filters to estimate the link acceleration and jerk from position and velocity measurements. Both observers are designed for the same model and run with the same covariance matrices under the same initial conditions. A five-bar linkage robot with revolute flexible joints is considered as a case study. Simulation results verify the effectiveness of the proposed filters.

scholarly journals Approximation of Linearized Systems to a Class of Nonlinear Systems Based on Dynamic Linearization

Symmetry ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 854
Author(s):  
Raquel S. Rodríguez ◽  
Gilberto Gonzalez Avalos ◽  
Noe Barrera Gallegos ◽  
Gerardo Ayala-Jaimes ◽  
Aaron Padilla Garcia
Keyword(s):  
Nonlinear System ◽  
Nonlinear Systems ◽  
Nonlinear Dynamic ◽  
Bond Graph ◽  
Physical Domain ◽  
Graph Models ◽  
Simple Task ◽  
Analysis And Synthesis ◽  
Simulation Results

An alternative method to analyze a class of nonlinear systems in a bond graph approach is proposed. It is well known that the analysis and synthesis of nonlinear systems is not a simple task. Hence, a first step can be to linearize this nonlinear system on an operation point. A methodology to obtain linearization for consecutive points along a trajectory in the physical domain is proposed. This type of linearization determines a group of linearized systems, which is an approximation close enough to original nonlinear dynamic and in this paper is called dynamic linearization. Dynamic linearization through a lemma and a procedure is established. Therefore, linearized bond graph models can be considered symmetric with respect to nonlinear system models. The proposed methodology is applied to a DC motor as a case study. In order to show the effectiveness of the dynamic linearization, simulation results are shown.

Limitations of Corrosion Resistant Alloy in High CO2 Gas Production Systems: A Case Study

2021 ◽  
Author(s):  
Jorge Rodriguez ◽  
Susana Gómez ◽  
Ngoc Tran Dinh ◽  
Giovanni Ortuño ◽  
Narendra Borole
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
High Pressure ◽  
Stainless Steel ◽  
Carbon Steel ◽  
Material Selection ◽  
Dynamic Modelling ◽  
General Corrosion ◽  
High Co2

Abstract The paper presents the application of a holistic approach to corrosion prediction that overcomes classical pitfalls in corrosion testing and modelling at high pressure, high temperature and high CO2 conditions. Thermodynamic modelling of field and lab conditions allows for more accurate predictions by a novel CO2/H2S general corrosion model validated by laboratory tests. In the proposed workflow, autoclave tests at high pressure and temperature are designed after modeling corrosion in a rigorous thermodynamic framework including fluid-dynamic modelling; the modeled steps include preparation, gas loading and heating of fluid samples at high CO2 concentration, and high flow velocities. An autoclave setup is proposed and validated to simultaneously test different conditions. Corrosion rates are extrapolated to compute service life of the materials and guide material selection. The results from the model and tests extend the application of selected stainless steel grade beyond the threshold conditions calculated by simplistic models and guidelines. Consideration of fugacities and true aqueous compositions allows for accurate thermodynamic representation of field conditions. Computation by rigorous fluid dynamics of shear stress, multiphase flow and heat transfer effects inside completion geometry lead to a proper interpretation of corrosion mechanisms and models to apply. In the case study used to showcase the workflow, conventional stainless steel is validated for most of the tubing. It is observed that some sections of the system in static condition are not exposed to liquid water, allowing for safe use of carbon steel, while as for other critical parts, more noble materials are deemed necessary. Harsh environments pose a challenge to the application of conventional steel materials. The workflow applied to the case study allows accurate representation and application of materials in its application limit region, allowing for safe use of carbon steel or less noble stainless steels in those areas of the completion where corrosion is limited by multiphase fluid-dynamics, heat transfer or the both. The approximation is validated for real case study under high CO2 content, and is considered also valid in the transportation of higher amounts of CO2, for example, in CCUS activities.

Reliability-Based Analysis and Optimization of the Gravity Balancing Performance of Spring-Articulated Serial Robots with Uncertainties

2021 ◽  
pp. 1-32
Author(s):  
Vu Linh Nguyen ◽  
Chin-Hsing Kuo ◽  
Po Ting Lin
Keyword(s):  
Pso Algorithm ◽  
Reliability Based Design Optimization ◽  
Swarm Optimization ◽  
Reliability Based Design ◽  
Serial Robots ◽  
Simulation Based ◽  
Serial Robot ◽  
Simulation Results ◽  
Uncertainty Level

Abstract This article proposes a method for analyzing the gravity balancing reliability of spring-articulated serial robots with uncertainties. Gravity balancing reliability is defined as the probability that the torque reduction ratio (the ratio of the balanced torque to the unbalanced torque) is less than a specified threshold. The reliability analysis is performed by exploiting a Monte Carlo simulation (MCS) with consideration of the uncertainties in the link dimensions, masses, and compliance parameters. The gravity balancing begins with a simulation-based analysis of the gravitational torques of a typical serial robot. Based on the simulation results, a gravity balancing design for the robot using mechanical springs is realized. A reliability-based design optimization (RBDO) method is also developed to seek a reliable and robust design for maximized balancing performance under a prescribed uncertainty level. The RBDO is formulated with consideration of a probabilistic reliability constraint and solved by using a particle swarm optimization (PSO) algorithm. A numerical example is provided to illustrate the gravity balancing performance and reliability of a robot with uncertainties. A sensitivity analysis of the balancing design is also performed. Lastly, the effectiveness of the RBDO method is demonstrated through a case study in which the balancing performance and reliability of a robot with uncertainties are improved with the proposed method.

scholarly journals An Assessment of Public Private Partnerships for Housing Projects in Bauchi State, North Eastern Nigeria

2016 ◽  
Vol 4 (1) ◽  
pp. 35
Author(s):  
Sanda Nehemiah Yakubu ◽  
Natalia A. Anigbogu ◽  
Mallo Maren Daniel
Keyword(s):  
Attitudinal Change ◽  
Structured Interviews ◽  
Housing Provision ◽  
Development Fund ◽  
Cultural Variations ◽  
Housing Projects ◽  
Wide Acceptance ◽  
Design Build ◽  
North Eastern

Public Private Partnership (PPP) has gained wide acceptance as a strategy for housing provision in many countries. However, the level of success varies from one country to the other due to economic, political and cultural variations. This study examines PPP in housing in Bauchi State in Nigeria using Unity Housing Estate as a case study with the view to examine its performance and to suggest possible measures for improving the effectiveness of the concept. Methods of data collection used were semi-structured interviews and direct observation. Interviews responses were tape-recorded in addition to note taking which were subsequently transcribed and validated. The model of PPP used in the area was the Design-Build-Finance arrangement in which the private party takes the responsibilities for the design, finance and construction of the housing units. The houses were far beyond the affordability level of the target beneficiaries. Some of the challenges depicted were lack of political will, corruption among government agents and private sector developers, insincerity of contacting parties and unavailability of development fund. The study suggests among others, attitudinal change among stakeholders to ensure the success of PPP housing, the need to establish and empower relevant institutions that will help in fighting corruption.

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