1,720,974 research outputs found
The Damage Assessment for Rapid Response (DARR) Method and its Application to Different Ground-Motion Levels and Building Types
Full text linkSeismic recordings in buildings and on the ground are increasingly available due to the increment and expansion of seismic monitoring networks worldwide. However, most urban strong‐motion networks consist of stations installed at the ground or, less frequently, in selected building’s basement. It is, therefore, of utmost importance to develop methods that can provide estimates of expected structural damage, starting from earthquake recordings at the ground level. Damage Assessment for Rapid Response (DARR) provides first‐level estimates of the expected damage to buildings, based on ground‐motion recordings and simple information on buildings’ characteristics. In this work, we apply DARR using both weak and strong ground‐motion recordings available for different low‐ and mid‐rise building typologies. A total of 9 buildings and 19 earthquake recordings were analyzed. DARR reproduces the shaking at the building’s top, and estimates the peak structural relative displacement or average interstory drift. Results show that the method works well for the considered building types and ground‐motion levels for the estimation of relative and total displacements using first‐order assessments. Comparison with the previously defined thresholds allows the estimation of expected damage. Our results (i.e., no damage for most buildings and events) are consistent with the absence of damaging events in northeastern Italy in the studied period (2019–2021). For a school building in central Italy, which was heavily damaged by the 2016 Central Italian sequence, DARR correctly predicted this fact
Applying the damage assessment for rapid response approach to the august 24 M6 event of the seismic sequence in central Italy (2016)
Full text linkSeismic monitoring networks are increasingly being used in urban areas to record and locate earthquakes. Recordings in the proximity of buildings also allow assessing, as a first approximation, the expected building damage. The DARR (Damage Assessment for Rapid Response) method provides local-scale information on expected damage patterns. The potential of this approach is discussed here for the August 24 M6 event of the Central Italy seismic sequence (2016-2017). We focus only on the first event of the sequence because cumulative damage is outside the scope of this study. The earthquake recordings are available from two Italian monitoring networks: the Italian Accelerometric Archive (ITACA) and the OSS (Osservatorio Sismico delle Strutture), which collects data from monitored buildings and bridges in Italy. We selected four target areas (Amatrice, Norcia, Visso and Sulmona) characterized by different epicentral distances and building typologies, that suffered different levels of damage during the M6 event on 24 August 2016. Using recordings either in the free field or in the basement of buildings, the expected relative displacement of building typologies common in the studied areas is calculated with the DARR method. Using predefined damage thresholds from literature, the obtained results allow quantifying the expected damage for dominant building typologies in the surroundings of the recording sites. We investigate and discuss the potential use and applicability of the DARR method in different areas depending on the epicentral distance and building characteristics. The results indicate that the DARR approach is useful for supporting and improving rapid response activities after a seismic event
Near-real-time damage estimation for buildings based on strong-motion recordings: An application to target areas in northeastern italy
Full text linkThe rapid estimation of expected impacts in case of an earthquake is extremely important for emergency managers and first responders. Current near-real-time damage assessment methods rely on ground-motion estimates and exposure or fragility datasets, in some cases integrating the shaking recorded at the site (e.g., from strong-motion monitoring networks). We propose a method that estimates the expected damages on buildings based on strong-motion recordings of a seismic event. The damage assessment is based on themaximumdrift (interstory) or the displacement, which is estimated by considering in a first approximation the behavior of a specific building typology as a single-degree-offreedom oscillator. The oscillator is characterized based on the analysis of the building stock and a large number of ambient vibration measurements performed in buildings. A specific damage state occurs when the interstory drift or displacement limits available in the literature for the specific building typology are exceeded. The method, here applied to a case study in northeastern Italy, can be applied to other seismic areas worldwide to provide quick, first-level estimates of expected damage
Hazard assessment of far-range volcanic ash dispersal from a violent Strombolian eruption at Somma-Vesuvius volcano, Naples, Italy: Implications on civil aviation
No full textLong-range dispersal of volcanic ash can disrupt civil aviation over large areas, as occurred during the 2010 eruption of Eyjafjallajökull volcano in Iceland. Here we assess the hazard for civil aviation posed by volcanic ash from a potential violent Strombolian eruption of Somma-Vesuvius, the most likely scenario if eruptive activity resumed at this volcano. A Somma-Vesuvius eruption is of concern for two main reasons: (1) there is a high probability (38 %) that the eruption will be violent Strombolian, as this activity has been common in the most recent period of activity (between AD 1631 and 1944); and (2) violent Strombolian eruptions typically last longer than higher-magnitude events (from 3 to 7 days for the climactic phases) and, consequently, are likely to cause prolonged air traffic disruption (even at large distances if a substantial amount of fine ash is produced such as is typical during Vesuvius eruptions). We compute probabilistic hazard maps for airborne ash concentration at relevant flight levels using the FALL3D ash dispersal model and a statistically representative set of meteorological conditions. Probabilistic hazard maps are computed for two different ash concentration thresholds, 2 and 0. 2 mg/m 3, which correspond, respectively, to the no-fly and enhanced procedure conditions defined in Europe during the Eyjafjallajökull eruption. The seasonal influence of ash dispersal is also analysed by computing seasonal maps. We define the persistence of ash in the atmosphere as the time that a concentration threshold is exceeded divided by the total duration of the eruption (here the eruption phase producing a sustained eruption column). The maps of averaged persistence give additional information on the expected duration of the conditions leading to flight disruption at a given location. We assess the impact that a violent Strombolian eruption would have on the main airports and aerial corridors of the Central Mediterranean area, and this assessment can help those who devise procedures to minimise the impact of these long-lasting low-intensity volcanic events on civil aviation. © 2012 Springer-Verlag
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
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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