59 research outputs found
Fundamental period of infilled reinforced concrete frame structures
No full textThe fundamental period of vibration appears to be one of the most critical parameters for the seismic design and assessment of structures. In the present paper, the results of a large-scale analytical investigation on the parameters that affect the fundamental period of reinforced concrete structures are presented. The influence of the number of storeys, the number of spans, the span length, the infill wall panel stiffness and the percentage of openings within the infill panel on the fundamental period of infilled RC frames was investigated. Based on these results, a regression analysis is applied in order to propose a new empirical equation for the estimation of the fundamental period. The derived equation is shown to have better predictive power compared with equations available in the literature
Parameters affecting the fundamental period of infilled RC frame structures
No full textDespite the fact that the fundamental period appears to be one of the most critical parameters for the seismic design of structures according to the modal superposition method, the so far available in the literature proposals for its estimation are often conflicting with each other making their use uncertain. Furthermore, the majority of these proposals do not take into account the presence of infills walls into the structure despite the fact that infill walls increase the stiffness and mass of structure leading to significant changes in the fundamental period numerical value. Toward this end, this paper presents a detailed and indepth analytical investigation on the parameters that affect the fundamental period of reinforce concrete structure. The calculated values of the fundamental period are compared against those obtained from the seismic code and equations proposed by various researchers in the literature. From the analysis of the results it has been found that the number of storeys, the span length, the stiffness of the infill wall panels, the location of the soft storeys and the soil type are crucial parameters that influence the fundamental period of RC buildings
On the Fundamental Period of Infilled RC Buildings
No full textThis paper investigates the fundamental period of vibration of RC buildings by means of finite element macro-modelling and modal eigenvalue analysis. As a base study, a number of 14-storey RC buildings have been considered \"according to code designed\" and \"according to code non-designed\". Several parameters have been studied including the number of spans; the span length in the direction of motion; the stiffness of the infills; the percentage openings of the infills and; the location of the soft storeys. The computed values of the fundamental period are compared against those obtained from seismic code and equations proposed by various researchers in the literature. From the analysis of the results it has been found that the span length, the stiffness of the infill wall panels and the location of the soft storeys are crucial parameters influencing the fundamental period of RC buildings
Delving into the effectiveness and limits of economic rhetoric in 17th-century Spain On the use and misuse of tropes in monetary treatises (1600–1642)
No full textThe rhetoric in economic treatises featuring proposed solutions to the economic
problems faced by 17th-century Castille, followed similar trends as the literature and
poetry of the baroque. These treatises are interesting from a semiotic point of view as
an array of tropes, particularly metaphors and simile, are commonplace in economic
literature. Drawing from the late Scholastics of the School of Salamanca (16th century), 17th-century treatises present a view of the whole economy, with a special focus on problems that required urgent solutions. Following a series of coin debasements carried out by Phillip III (1578–1621) and Phillip IV (1605–1665), 17th-century Castille went through decades of monetary instability and was in constant need of monetary reforms. This chapter presents a collection of tropes found in monetary writings. A fuller picture of the perception and the portrayal of monetary problems in 17th-century Castille has been sought by integrating a semiotic perspective to the analysis of rhetoric in economic treatises
Prediction of the fundamental period of infilled rc frame structures using artificial neural networks
No full textThe fundamental period is one of the most critical parameters for the seismic design of structures. There are several literature approaches for its estimation which often conflict with each other, making their use questionable. Furthermore, the majority of these approaches do not take into account the presence of infill walls into the structure despite the fact that infill walls increase the stiffness and mass of structure leading to significant changes in the fundamental period. In the present paper, artificial neural networks (ANNs) are used to predict the fundamental period of infilled reinforced concrete (RC) structures. For the training and the validation of the ANN, a large data set is used based on a detailed investigation of the parameters that affect the fundamental period of RC structures. The comparison of the predicted values with analytical ones indicates the potential of using ANNs for the prediction of the fundamental period of infilled RC frame structures taking into account the crucial parameters that influence its value
Convolution-based ensemble learning algorithms to estimate the bond strength of the corroded reinforced concrete
No full textReinforced concrete bond strength deterioration is one of the most serious problems in the construction industry. It is one of the most common factors impacting structural deterioration and the major cause of premature decadence of reinforced concrete structures. Therefore, developing an accurate model with the lowest variance and high reliability for the bond strength of corroded reinforced concrete is very important. The current work evaluates the efficiency of convolution-based ensemble learning algorithms. To address these issues, convolution-based ensemble learning models are developed using a database collected from the previous experimental studies of relative bond strength for corroded reinforced concrete. Seven parameters are considered as inputs, including bar diameter, the ratio of concrete cover to bar diameter, the ratio of the bar diameter to embedment length, transverse reinforcement ratio, yielding strength, concrete compressive strength and the corrosion level. Results indicate that the convolution-based integrated stacking model produces excellent predictions with the coefficient of determination, a-20 index, and mean square error values of 0.84, 0.75, and 0.022. Since machine learning based models are commonly black-box models, the Shapley Additive Explanations (SHAP) method is used to explicitly relate the predicted output to the inputs. Based on SHAP, the corrosion level, concrete compressive strength, transverse reinforcement ratio, and the concrete cover to bar diameter ratio are ranked among the most influential parameters on the bond strength of the corroded reinforced concrete
Review of M. C. Marcuzzo's Essays in Keynesian Persuasion, (2019, Newcastle upon Tyne: Cambridge Scholars) [Review]
No full textMarcuzzo’s Essays in Keynesian Persuasion is a collection of 15 papers published between 2002 and 2018 with a focus on the work and thought of John Maynard Keynes from a variety of perspectives. It can be seen as a companion volume to Fighting Market Failure (Marcuzzo, 2012), which is a collection of 15 papers published between 1994 and 2008 on the pantheon of economists that constitute the Cambridge
school of economics
Α Review of Surface and Lower Troposphere Ozone Concentration Characteristics Around the Urban Area of Athens, the Aegean Sea and at the Central and Eastern Mediterranean
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From neoclassical theory to mainstream modelling: fifty years of moral hazard in perspective
No full textA climatological study of rural surface ozone in central Greece
No full textRecent studies show that surface ozone levels at rural sites in Greece are generally high when compared with rural ozone measurements at northern European sites. The area of SE Europe, including Greece, is not very well monitored regarding rural ozone in comparison to central and northern Europe. In order to have the best possible picture of the rural surface ozone climatology in the area, based on the available data-sets of long-term continuous monitoring stations, the 10-year measurement records (1987-1996) of the Athens peripheral station of Liossia, (12 km N of the city center) and the urban background station of Geoponiki (3 km W) as well as the 4-year record (1996-1999) of the rural station of Aliartos (100 km NW of Athens), are analyzed in this paper. The data for Liossia and Geoponiki stations are screened for cases of strong airflow from rural areas (N-NE winds stronger than 5 m/s). The variation characteristics of the average rural ozone afternoon levels (12:00-18:00), with the best vertical atmospheric mixing, are mainly examined since these measurements are expected to be representative of the broader area. In all three stations there is a characteristic seasonal variation of rural ozone concentrations with lowest winter afternoon values at about 50 μg/m3 in December-January and average summer afternoon values at about 120 μg/m3 in July-August, indicating that high summer values are observed all over the area. The rural summer afternoon ozone values are very well correlated between the three stations, implying spatial homogeneity all over the area but also temporal homogeneity, since during the 13-year period 1987-1999 the rural afternoon ozone levels remained almost constant around the value of 120 μg/m3
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