scholarly journals Optimum design of a composite floor system considering environmental and economic impacts

2022 ◽  
Vol 15 (3) ◽  
Author(s):  
Paulo Augusto T. Arpini ◽  
Mayane C. Loureiro ◽  
Breno D. Breda ◽  
Adenílcia F. Calenzani ◽  
Élcio C. Alves
Keyword(s):  
Environmental Impact ◽  
Co2 Emissions ◽  
Optimization Problem ◽  
Concrete Slab ◽  
Economic Impacts ◽  
Optimal Solution ◽  
Design Solution ◽  
Existing Building ◽  
Floor System ◽  
Steel Deck

Abstract The composite floor system, composed of steel deck and concrete slab, generates more efficient and economical structures. On the other hand, the design of this type of structure has a high complexity level due to the consideration of several variables. In this respect, the objective of this paper is to present the formulation of the optimization problem for a composite floor system (steel and concrete) considering such environmental as economic impacts. To formulate the optimization problem, the reduction of environmental impact was adopted as an objective function - assuming the CO2 emission and the finance cost as parameters. The restrictions were taken by the limiting states imposed in standard NBR 8800:2008. The computer program was developed via Matlab R2016a and the optimization process was carried out using the Genetic Algorithm toolbox existing in this platform. Two application examples of the formulation at hand are presented: the first from the literature and the second from an existing building - in both situations the influences of different concrete compressive characteristic strengths were analyzed. The results of the optimization problem show a reduction in geometry and, consequently, in its weight. The solution found by the program reduces by up to 17.70% of CO2 emissions and 17.47% of the finance cost. When was applying different concrete compressive strengths, the optimal solution for environmental impact did not get the lowest cost. In general, the steel deck formwork obtained the highest percentage of environmental impact, while the beams and girders, with the same shape configuration, had the highest finance cost. Therefore, it is shown that the optimal design solution to CO2 emissions is not always the better solution for the finance cost.

scholarly journals SLIM FLOOR: MÉTODO DE DIMENSIONAMENTO E ESTUDO PARAMÉTRICO

2016 ◽  
Vol 13 (1) ◽  
Author(s):  
Vander Júnior De Mesquita Santos ◽  
Débora Machado de Lima ◽  
Felipe Isamu Harger Sakiyama
Keyword(s):  
Design Methodology ◽  
Concrete Slab ◽  
Steel Beam ◽  
Total Height ◽  
Calculation Results ◽  
Floor System ◽  
Steel Deck ◽  
Current Standards

RESUMO: Slim Floor é um sistema de pisos mistos aço-concreto de pequena elevação no qual a laje de concreto encontra-se embutida na altura da viga de aço, estando apoiada na mesa inferior do perfil. Este trabalho teve como objetivo estudar essa tipologia de estrutura, verificando a sua eficiência frente à conformação mista convencional de lajes e vigas, comumente conhecida como Steel Deck. Este artigo apresenta a metodologia de dimensionamento de um pavimento Slim Floor bem como os resultados de cálculo para uma estrutura Steel Deck, obtidos por meio do software VigaMix. Foram realizadas análises que envolveram parâmetros como o peso da viga, altura do piso, consumo de concreto e deformação. Dessa maneira, o sistema Slim Floor apresentou vantagens quanto aos aspectos construtivos, econômicos, estéticos e, principalmente em relação à altura total do pavimento. A maior contribuição deste estudo foi oferecer uma orientação para o dimensionamento de Slim Floor, visto que os critérios para a concepção deste tipo de estrutura ainda não se encontram totalmente consolidados nas normas atuais. ABSTRACT: Slim floor system is a mixed steel-concrete floors small elevation in which the concrete slab is built on the height of the steel beam, being supported on the lower flange of the profile. This work aimed to study this type of structure, checking their front efficiency to conventional mixed forming slabs and beams, commonly known as Steel Deck. This paper presents the design methodology of a floor Slim Floor as well as the calculation results for Steel Deck structure obtained through VigaMix software. Analyses were performed involving parameters such as the weight of the beam, floor height, concrete consumption and deformation. In this way, Slim Floor system had advantages as the constructive, economic, aesthetic, and especially in relation to the total height of the floor. The major contribution of this study was to provide guidance for the design of Slim Floor, as the criteria for the design of this type of structure has not yet been fully consolidated in the current standards.

DESIGN AND PERFORMANCE OF HIGH-RISE STRUCTURE USING ULTRA-LIGHTWEIGHT CROSS LAMINATED TIMBER FLOOR SYSTEM

2020 ◽  
Vol 7 (2) ◽  
Author(s):  
Danish Ahmed ◽  
Tahar Ayadat ◽  
Andi Asiz
Keyword(s):  
Concrete Slab ◽  
Performance Criteria ◽  
Structural Performance ◽  
Lateral Loads ◽  
Reinforced Concrete Slab ◽  
Existing Building ◽  
Cross Laminated Timber ◽  
High Rise ◽  
Rc Slab ◽  
Floor System

The main objective of this paper is to study the structural performance of a high-rise structure when alternative lightweight material known as cross-laminated timber was used as a slab in floor system in lieu of conventional reinforced concrete slab. A numerical case study was conducted using a highly irregular RC frame building with its two 60-story towers joined at the top. Three major analyses were considered. First, modeling and analyzing the building with an RC slab was conducted to determine the design reference. Second, substituting the RC slab with the CLT slab was performed using the same building skeleton. Third, redesigning and optimizing the building skeleton with that CLT to observe skeleton material saving obtained using the same structural performance criteria. Major lateral loads applicable in the Eastern Province of Saudi Arabia were inputted. Strengths and serviceability requirements for floor diaphragm and lateral load resisting system were checked first before performing a comparative analysis between traditional RC and CLT slabs as floor diaphragm. The structural performance criteria to be used for comparative study between RC and CLT slabs included total drift, inter-story drift due to lateral loads, and base reactions. Structural periods and acceleration responses for each floor were investigated and contrasted with the existing building code. The foundation demand was also investigated based on the structural weight and reactions generated from the RC and CLT floor systems.

scholarly journals Analytical Study on the Behaviour of Composite Space Truss Structures with Openings in a Concrete Slab

2020 ◽  
Vol 30 (3) ◽  
pp. 265-280
Author(s):  
Palanivelu Sangeetha
Keyword(s):  
Concrete Slab ◽  
Three Dimensional ◽  
Optimal Solution ◽  
Absorption Capacity ◽  
Truss Structures ◽  
Space Truss ◽  
Linear Elements ◽  
Support Conditions ◽  
Pattern Forming ◽  
Floor System

Abstract A space truss structural system is a three-dimensional arrangement of linear elements in a pyramid pattern forming a Double Layer Grid (DLG) system. Space trusses are an elegant and economical means of covering larger areas such as roof systems, in a wide variety of applications such as a stadium, aircraft-hanger, assembly hall, etc. The major problem encountered in using the space truss as a roofing system is the sudden failure of the whole structure due to critical buckling of the top chord member. Earlier research has shown that the optimal solution to overcome such a failure is by providing a small thickness of concrete slab over the space truss, so that the space truss with concrete slab (Composite Space Truss) will act as a floor system for the multi-storey building. For better ventilation and lighting in the building, the need for openings in the composite space truss is unavoidable; however, providing an opening in the concrete slab will reduce the load carrying capacity of the structure. The analysis of a composite space truss of size 30m x 30m with all possible locations of openings for four different support conditions was carried out using ANSYS in order to study the load - deflection behaviour. Further, the ductility factor and energy absorption capacity of the composite space truss with different locations of slab openings were compared.

A new algorithm for finding CRM-model coefficients

2019 ◽  
Vol 5 (3) ◽  
pp. 164-185 ◽  
Author(s):  
Alexander D. Bekman ◽  
Sergey V. Stepanov ◽  
Alexander A. Ruchkin ◽  
Dmitry V. Zelenin
Keyword(s):  
Approximate Solution ◽  
Optimization Problem ◽  
Optimal Solution ◽  
Complex Form ◽  
Approximate Solutions ◽  
The Other ◽  
Programming Algorithm ◽  
Stochastic Algorithms ◽  
Large Set ◽  
Flow Rates

The quantitative evaluation of producer and injector well interference based on well operation data (profiles of flow rates/injectivities and bottomhole/reservoir pressures) with the help of CRM (Capacitance-Resistive Models) is an optimization problem with large set of variables and constraints. The analytical solution cannot be found because of the complex form of the objective function for this problem. Attempts to find the solution with stochastic algorithms take unacceptable time and the result may be far from the optimal solution. Besides, the use of universal (commercial) optimizers hides the details of step by step solution from the user, for example&nbsp;— the ambiguity of the solution as the result of data inaccuracy.<br> The present article concerns two variants of CRM problem. The authors present a new algorithm of solving the problems with the help of “General Quadratic Programming Algorithm”. The main advantage of the new algorithm is the greater performance in comparison with the other known algorithms. Its other advantage is the possibility of an ambiguity analysis. This article studies the conditions which guarantee that the first variant of problem has a unique solution, which can be found with the presented algorithm. Another algorithm for finding the approximate solution for the second variant of the problem is also considered. The method of visualization of approximate solutions set is presented. The results of experiments comparing the new algorithm with some previously known are given.

scholarly journals Algebraic Solution to Constrained Bi-Criteria Decision Problem of Rating Alternatives through Pairwise Comparisons

Mathematics ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 303
Author(s):  
Nikolai Krivulin
Keyword(s):  
Decision Problem ◽  
Optimization Problem ◽  
Pareto Frontier ◽  
Sufficient Conditions ◽  
Approximation Error ◽  
Optimal Solution ◽  
Algebraic Solution ◽  
Pairwise Comparisons ◽  
Logarithmic Scale ◽  
Idempotent Algebra

We consider a decision-making problem to evaluate absolute ratings of alternatives from the results of their pairwise comparisons according to two criteria, subject to constraints on the ratings. We formulate the problem as a bi-objective optimization problem of constrained matrix approximation in the Chebyshev sense in logarithmic scale. The problem is to approximate the pairwise comparison matrices for each criterion simultaneously by a common consistent matrix of unit rank, which determines the vector of ratings. We represent and solve the optimization problem in the framework of tropical (idempotent) algebra, which deals with the theory and applications of idempotent semirings and semifields. The solution involves the introduction of two parameters that represent the minimum values of approximation error for each matrix and thereby describe the Pareto frontier for the bi-objective problem. The optimization problem then reduces to a parametrized vector inequality. The necessary and sufficient conditions for solutions of the inequality serve to derive the Pareto frontier for the problem. All solutions of the inequality, which correspond to the Pareto frontier, are taken as a complete Pareto-optimal solution to the problem. We apply these results to the decision problem of interest and present illustrative examples.

scholarly journals Quit When You Can: Efficient Evaluation of Ensembles by Optimized Ordering

2021 ◽  
Vol 17 (4) ◽  
pp. 1-20
Author(s):  
Serena Wang ◽  
Maya Gupta ◽  
Seungil You
Keyword(s):  
Optimization Problem ◽  
Optimal Solution ◽  
Combinatorial Optimization Problem ◽  
Joint Optimization ◽  
Early Stopping ◽  
Time Approximation ◽  
Approximation Bound ◽  
Evaluation Time ◽  
Speed Up ◽  
Real World Problems

Given a classifier ensemble and a dataset, many examples may be confidently and accurately classified after only a subset of the base models in the ensemble is evaluated. Dynamically deciding to classify early can reduce both mean latency and CPU without harming the accuracy of the original ensemble. To achieve such gains, we propose jointly optimizing the evaluation order of the base models and early-stopping thresholds. Our proposed objective is a combinatorial optimization problem, but we provide a greedy algorithm that achieves a 4-approximation of the optimal solution under certain assumptions, which is also the best achievable polynomial-time approximation bound. Experiments on benchmark and real-world problems show that the proposed Quit When You Can (QWYC) algorithm can speed up average evaluation time by 1.8–2.7 times on even jointly trained ensembles, which are more difficult to speed up than independently or sequentially trained ensembles. QWYC’s joint optimization of ordering and thresholds also performed better in experiments than previous fixed orderings, including gradient boosted trees’ ordering.

scholarly journals The Intra-EU Value Chain: An Approach to Its Economic Dimension and Environmental Impact

Economies ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 54
Author(s):  
Óscar Rodil-Marzábal ◽  
Hugo Campos-Romero
Keyword(s):  
Environmental Impact ◽  
Co2 Emissions ◽  
Value Chain ◽  
Positive Impact ◽  
Value Added ◽  
Kuznets Curve ◽  
Output Analysis ◽  
Economic Dimension ◽  
Development Levels ◽  
European Economies

This paper aims to analyze the economic dimension and environmental impact of intra-EU value-added generation linked to global value chains (GVCs) through input-output analysis. For this purpose, information has been collected from TiVA (Trade in Value Added, OECD) and Eora databases for the years 2005 and 2015. From an economic perspective, the results point to a strengthening of the value-added generated within Factory Europe. From an environmental perspective, all EU28 members have reduced their exports-related impacts in intensity-emissions terms, but not all of them in the same degree. An approach to the environmental Kuznets curve (EKC) has also been carried out through a panel data model. The results show a positive impact of the participation in intra-EU value chain (Factory Europe) on CO2 emissions per capita. Further, an inverted U-shaped curve for CO2 emissions is found for the period 2005–15. In this sense, European economies with lower development levels (many Eastern and Southern countries) seem to be still on the rising segment of the curve, while the more developed ones seem to be on the decreasing segment. These results highlight the need to design global monitoring and prevention mechanisms to tackle growing environmental challenges and the need to incorporate specific actions associated with the GVCs activity.

scholarly journals What Is the Environmental Impact of Wine Entering Global Value Chains? Studying the Evolution of CO2 Emissions from the Export of Spanish Denomination of Origin Wines

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1664
Author(s):  
Juan Sebastián Castillo-Valero ◽  
Inmaculada Carrasco ◽  
Marcos Carchano ◽  
Carmen Córcoles
Keyword(s):  
Environmental Impact ◽  
Co2 Emissions ◽  
Carbon Footprint ◽  
Environmental Performance ◽  
Service Provision ◽  
International Markets ◽  
Value Chains ◽  
Input Output ◽  
Continuous Growth ◽  
Wine Trade

The continuous growth of the international wine trade and the expansion of international markets is having significant commercial, but also environmental, impacts. The benefits of vineyards in terms of ecosystem service provision are offset by the increase in CO2 emissions generated by transportation. Denominations of Origin, as quality labels, emphasise a wine’s links to the terroir, where specific elements of culture and environment merge together. However, Denominations of Origin can also have differentiating elements as regards environmental performance. Drawing on an extended multiregional input–output model applied to the Spanish Denominations of Origin with the largest presence in the international wine trade, this study shows that wines with the greatest exporting tradition are those that most reduced their carbon footprint per litre of exported wine in the period 2005–2018, thus being the most environmentally efficient.

scholarly journals Robust Beamforming Design for Secure V2X Downlink System with Wireless Information and Power Transfer under a Nonlinear Energy Harvesting Model

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3294 ◽  
Author(s):  
Shidang Li ◽  
Chunguo Li ◽  
Weiqiang Tan ◽  
Baofeng Ji ◽  
Luxi Yang
Keyword(s):  
Energy Harvesting ◽  
Traffic Safety ◽  
Optimization Problem ◽  
Optimal Solution ◽  
Base Station ◽  
Power Splitting ◽  
Power Transfer ◽  
Vehicular Communication ◽  
Downlink System ◽  
Nonlinear Energy

Vehicle to everything (V2X) has been deemed a promising technology due to its potential to achieve traffic safety and efficiency. This paper considers a V2X downlink system with a simultaneous wireless information and power transfer (SWIPT) system where the base station not only conveys data and energy to two types of wireless vehicular receivers, such as one hybrid power-splitting vehicular receiver, and multiple energy vehicular receivers, but also prevents information from being intercepted by the potential eavesdroppers (idle energy vehicular receivers). Both the base station and the energy vehicular receivers are equipped with multiple antennas, whereas the information vehicular receiver is equipped with a single antenna. In particular, the imperfect channel state information (CSI) and the practical nonlinear energy harvesting (EH) model are taken into account. The non-convex optimization problem is formulated to maximize the minimum harvested energy power among the energy vehicular receivers satisfying the lowest harvested energy power threshold at the information vehicular receiver and secure vehicular communication requirements. In light of the intractability of the optimization problem, the semidefinite relaxation (SDR) technique and variable substitutions are applied, and the optimal solution is proven to be tight. A number of results demonstrate that the proposed robust secure beamforming scheme has better performance than other schemes.

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