1,721,026 research outputs found
Fragility curves for reinforced concrete frames characterised by different regularity
Full text linkThis paper presents a comparison between fragility curves developed for regular and non-regular reinforced frames.
Three 3D reinforced concrete multi-story frames characterised by different regularity are analysed. These fragility
curves are developed through the “Cloud Analysis“ procedure, which evaluates the structural response via Non-Linear
Time History Analysis (NLTHA).
Both maximum inter-story drift and maximum chord-rotation demand/capacity ratio are used as Engineering
Demand Parameters, in which the chord-rotation capacity is calculated according to the Italian Code. To fully develop
the fragility curves, both structure-independent and structure-dependent scalar intensity measures are selected among
the most referred in practice and literature.
This work shows the influence of regularity on the damage levels of the three buildings. Furthermore, it shows the
uncertainties caused by the selection criteria for EDP thresholds, which are necessary for a correct representation of
the Limit State
The Agency Problem, Financial Performance and Corruption: Country, Industry and Firm Level Perspectives
Full text linkThis paper studies the relationship between the agency problem, financial performance and corruption from country, industry and firm level perspectives. First, we observe that companies operating in countries with a high level of corruption tend to display relatively low returns. Second, in an industry-by-industry context, we find that the negative relationship between corruption and average stock returns is stronger in specific industries, which
we define as ‘corruption sensitive’. Third, at the firm level, we show that agency problems are exacerbated in corruption-sensitive industries. Our study builds on the existing literature in three main areas. First, it proposes a novel macro-based approach aimed at identifying corruption-sensitive industries. Second, it provides evidence supporting that corruption exacerbates agency conflicts. Third, it provides evidence on the generalizability of standard corporate governance predictions to companies operating in corruption-sensitive industries
Materiality in integrated and sustainability reporting: A paradigm shift?
No full textThis paper investigates the implementation of integrated reporting (IR) by Generali, one of the most important listed companies in Italy. The research questions we aim at answering are the following: Is the IR approach to materiality inherently different from the sustainability reporting (SR) approach? Does IR lead to the identification of different material topics than does SR? On the one hand, institutional theory suggests that IR and SR material topics are going to be significantly different because IR is mainly driven by a market logic, whereas SR is inspired by a stakeholder logic. On the other hand, organizational change theory predicts there will be some resistance to change by the organization, therefore leading to IR and SR topics being similar. In order to answer our research questions, we implement two empirical analyses. First, we propose and develop an innovative methodological approach on the basis of content analysis, which allows measuring the materiality of different issues under the IR approach. Second, we rely on evidence obtained through interviews, which suggests that IR and SR approaches to materiality are inherently different
Are loyalty shares an effective antidote against short-termism? Empirical evidence from Italy
No full textCorporate short-termism is arguably one of the main causes of economic, social, and environmental unsustainability. This paper studies the effectiveness of loyalty shares—shares granting extra dividends or voting rights to shareholders holding them for a specified period of time—in limiting short-termism. Although there are arguments both supporting (antidote view) and opposing (poison view) loyalty shares' effectiveness, empirical evidence on the theme is scant. By employing earnings management as a proxy for corporate short-termism and by relying on a hand-collected database of Italian firms, we find that loyalty shares can serve as an effective antidote against short-termism. This study contributes to academic literature on corporate governance and accounting and informs the debate among policymakers on loyalty shares' effectiveness
Problematiche progettuali e proposte di soluzione per controventi in acciaio a diagonale tesa attiva – Parte I: tracciamento analitico delle curve di pushover
No full textSOMMARIO
Nel presente lavoro e in [1] si vanno ad approfondire una serie di problematiche progettuali relative ai
controventi in acciaio a diagonale tesa attiva (detti anche a croce di Sant’Andrea), analizzando sia edifici
monopiano industriali che multipiano.
In questa prima parte si analizza il comportamento di questo tipo di controventi proponendo la costruzione
di un “fuso” di pushover, caratterizzato da due curve analitiche trilineari di capacità definite su un sistema
controventato assoggettato ad una prefissata distribuzione di forze laterali. La bontà di tale proposta
analitica viene evidenziata da una serie di confronti numerici ottenuti con un accurato modello di calcolo,
validato sulla base di risultati sperimentali. La proposta viene estesa ad intere strutture monopiano e
multipiano, evidenziando per i casi studio analizzati un’ottima corrispondenza con i risultati numerici.
ABSTRACT
In this work and in the companion article [1] some important issues related to the design of concentric
braced steel frames (CBF) with active tension diagonal bracings are analyzed by examining single-storey
industrial buildings and multi-storey buildings.
In this first part, the behaviour of this type of bracing is analyzed and the construction of a pushover
“spindle”, characterized by two trilinear analytical capacity curves defined on a CBF system subjected to
prefixed lateral forces distribution, is proposed. The goodness of this analytical proposal is validated by a
series of numerical comparisons obtained through an accurate calculation model, calibrated on the basis of
experimental results. The proposal is then extended to entire single- and multi-storey structures, showing a
good correspondence with the numerical results of the analysed case studies
Problematiche progettuali e proposte di soluzione per controventi in acciaio a diagonale tesa attiva – Parte II: progettazione di sistemi controventati mediante uso di una rigidezza equivalente per l’analisi elastica modale con spettro di risposta
No full textSOMMARIO
Nel presente lavoro e in [1] si approfondiscono alcune problematiche progettuali relative ai controventi in
acciaio a diagonale tesa attiva (detti anche a croce di Sant’Andrea). Dopo aver analizzato il comportamento
di questo tipo di controventi e proposto la costruzione di curve di pushover analitiche trilineari, in questo
secondo lavoro si presenta un metodo generale di progettazione, applicabile sia ad edifici monopiano
industriali che multipiano, dotati di questa tipologia di controvento. Il metodo è basato sull’utilizzo
dell’analisi elastica modale con spettro di risposta, condotta tramite l’utilizzo di una rigidezza elastica
opportunamente modificata. Mediante l’analisi di una serie di casi studio, si dimostra l’affidabilità del
metodo progettuale proposto, effettuando una serie di confronti numerici e validando il metodo con analisi
dinamiche al passo.
ABSTRACT
In this work and in [1] some important issues related to the design of concentric braced steel frames (CBF)
with active tension diagonal bracings are analyzed. In [1] the behaviour of this type of bracing was analyzed
and the construction of a trilinear analytic pushover curve was proposed. In this work a general method for
the design of CBF buildings, applicable to both single and multi-storey structures, is presented. The method
is based on the use of an elastic modal analysis with response spectrum, carried out on models using an
appropriate modified elastic stiffness of diagonal bracings. The reliability of the proposed method is
validated through the analysis of significant case studies, making a series of numerical comparisons by
carrying out time-history dynamic analysis
Physics-based ground motion simulations for the prediction of the seismic vulnerability of masonry building compounds in Mirandola (Italy)
No full textThe current paper aims at investigating the seismic capacity of a masonry building aggregate in the historical centre of Mirandola based on a reliable ground motion simulation procedure. The examined clustered building is composed of eleven structural units (SUs) mutually interconnected to each other, which are made of brick walls and are characterized by wooden floors poorly connected to the vertical structures. Non-linear static analyses are performed by adopting the 3Muri software to characterize the seismic capacity of both the entire aggregate and the individual SUs. In this framework, a multi-scenario physics-based approach is considered for the definition of the seismic input in terms of broadband seismic signals inclusive of source and site effects. Finally, the incidence of the seismic input variability is discussed for the prediction of the global capacity response of the case study building
Assessment of the effect of seismic sequences on steel X-CBF for industrial buildings
Full text linkThis work concerns about the study of the effect of the seismic sequences on steel mono-storey industrial buildings equipped with X-CBFs, with the aim to evaluate a code change to adequately consider this issue. Indeed, current technical regulations (CEN, 2004; MIT, 2018) do not take into account this phenomenon, thus the structure are designed only to withstand a single main-shock, without considering the possible accumulation of damage due to the after-shocks. In this work it is instead shown how this effect has to be properly considered and evaluated. First, a mono-storey industrial building is analysed as preliminary case study. Fragility curves are built for both sequences and single main events, thus obtaining an important comparison. Then the study focuses on a single X-CBF, validated through an experimental test from literature. The calibrated system is subjected to both seismic sequences and corresponding mainshocks. Analyses are carried out also by varying brace profiles. The results show a significant influence of the seismic sequences on the increase of the ductility request of the structure. Therefore, with the aim to properly represent the effect of the sequences, it is considered necessary to require a reduction of the available behavior factor, providing a precautionary estimate. This operation wants to give a first preliminary estimate of the increase of the seismic risk only on the seismic vulnerability side of this kind of structures
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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