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Sergio Lagomarsino - One of the best experts on this subject based on the ideXlab platform.
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PERPETUATE guidelines for seismic Performance-Based Assessment of cultural heritage masonry structures
Bulletin of Earthquake Engineering, 2015Co-Authors: Sergio Lagomarsino, Serena CattariAbstract:Ancient monumental masonry buildings are complex structures that were not based on an engineered design, underwent many transformations during their life and often present lack of connections among the structural elements. Earthquakes are the main cause of damage for ancient masonry structures and, in order to reduce their vulnerability with compatible and light interventions, it is necessary to have accurate models for the seismic analysis, able to simulate the nonlinear behavior of masonry, and a well defined Performance-Based Assessment procedure, aimed to guarantee the acceptable level of risk for the occupants and for the conservation of the monument itself. The paper outlines the guidelines that were developed within the PERPETUATE European research project. The wide variety of architectural assets is classified and the related proper modeling strategies are identified; moreover, immovable artistic assets are considered in the Assessment. A displacement-based approach is adopted, because these structures crack even for low intensity earthquakes and can survive severe ones only if they have a sufficient displacement capacity. Safety and conservation requirements are proposed by considering distinct sets of performance levels, related to use and safety of people, conservation of the building and of the artistic assets that might be present. Some indications on the seismic hazard Assessment are provided, considering the distinctive features of some types of ancient structures. Within the fundamental knowledge phase, sensitivity analysis is proposed in order to address and optimize the in-situ investigation and to define proper confidence factors, aimed to consider epistemic and statistical uncertainties. Different modeling approaches and methods of analysis are considered, depending on the characteristics of the structure; both static pushover and incremental dynamic nonlinear analyses are considered. Related verification procedures are defined to evaluate the seismic intensity measure, and the corresponding return period, which is compatible with each performance level that must be fulfilled.
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Performance-Based Assessment of the Great Mosque of Algiers
Bulletin of Earthquake Engineering, 2014Co-Authors: M. Rossi, Serena Cattari, Sergio LagomarsinoAbstract:The seismic Performance-Based Assessment (PBA) of monumental buildings requires to consider safety and conservation objectives, including also the possible presence of artistic assets. In order to face these issues, the case study of the Great Mosque of Algiers is analysed in this paper: in fact, besides to be one of the remaining Almoradiv architecture and the oldest mosque of the city, it is also characterized by the presence of a mihrâb, a decorated arched niche that represents an interesting artistic asset to be included in the PBA. Within this context, particular attention has been paid to the choice of the most reliable modelling strategy for the application of the displacement approach in the PBA procedure, as a function of different possible seismic behaviours. In the case of Great Mosque both the current state of the building and a virtual strengthened condition are analysed. It is worth noting that, while in the current state the seismic behaviour of the asset is well described by a set of macroelements that may be analysed independently (through 2D models), in the second case the strengthening intervention leads to the adoption of a 3D global model (indeed, the roof bracing promotes a “box-type” behaviour). In the paper, the integrate use of three different modelling strategies of different complexity is discussed: the finite element model, the equivalent frame approach and the macro-block model. The results of nonlinear analyses performed (static and kinematic) constitute the main tool to interpret the seismic response of the asset, perform the PBA and address the choice on the rehabilitation decisions. These latter in this case are mainly affected by the occurrence of too high deformations in local portions of the building, including that in which the artistic asset is located.
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Seismic Performance-Based Assessment of “Gaioleiro” buildings
Engineering Structures, 2014Co-Authors: Ana G. Simões, Rita Bento, Serena Cattari, Sergio LagomarsinoAbstract:Abstract “Gaioleiro” buildings are unreinforced masonry buildings with flexible timber floors associated with the urban expansion of Lisbon at the end of the nineteenth century and beginning of the twentieth century. This paper presents the results from the seismic Performance-Based Assessment of a “Gaioleiro” building case study, assumed as a prototype representative of wide number of buildings. The Assessment was addressed to the global seismic response of the building, mainly governed by the in-plane capacity of the masonry walls, and to the local response, related to the activation of out-of-plane mechanisms of parts of the building. The global behaviour was determined by non-linear static analyses and the effects of some relevant modelling options were considered; in particular, parametric analyses were carried out taking into account the strength capacity of spandrel beams and the influence of the degree of connection between walls. The local behaviour was determined with limit non-linear kinematic analysis. The seismic Performance-Based Assessment was set by the comparison of the structural capacity, with reference to various limit states (as proposed in Eurocode 8), with the seismic demand for Lisbon, related to different return periods. Different approaches to define such limits on the capacity curve were assumed in order to discuss the reliability of criteria proposed in codes for the case of structures characterized by flexible floors.
Serena Cattari - One of the best experts on this subject based on the ideXlab platform.
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PERPETUATE guidelines for seismic Performance-Based Assessment of cultural heritage masonry structures
Bulletin of Earthquake Engineering, 2015Co-Authors: Sergio Lagomarsino, Serena CattariAbstract:Ancient monumental masonry buildings are complex structures that were not based on an engineered design, underwent many transformations during their life and often present lack of connections among the structural elements. Earthquakes are the main cause of damage for ancient masonry structures and, in order to reduce their vulnerability with compatible and light interventions, it is necessary to have accurate models for the seismic analysis, able to simulate the nonlinear behavior of masonry, and a well defined Performance-Based Assessment procedure, aimed to guarantee the acceptable level of risk for the occupants and for the conservation of the monument itself. The paper outlines the guidelines that were developed within the PERPETUATE European research project. The wide variety of architectural assets is classified and the related proper modeling strategies are identified; moreover, immovable artistic assets are considered in the Assessment. A displacement-based approach is adopted, because these structures crack even for low intensity earthquakes and can survive severe ones only if they have a sufficient displacement capacity. Safety and conservation requirements are proposed by considering distinct sets of performance levels, related to use and safety of people, conservation of the building and of the artistic assets that might be present. Some indications on the seismic hazard Assessment are provided, considering the distinctive features of some types of ancient structures. Within the fundamental knowledge phase, sensitivity analysis is proposed in order to address and optimize the in-situ investigation and to define proper confidence factors, aimed to consider epistemic and statistical uncertainties. Different modeling approaches and methods of analysis are considered, depending on the characteristics of the structure; both static pushover and incremental dynamic nonlinear analyses are considered. Related verification procedures are defined to evaluate the seismic intensity measure, and the corresponding return period, which is compatible with each performance level that must be fulfilled.
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Performance-Based Assessment of the Great Mosque of Algiers
Bulletin of Earthquake Engineering, 2014Co-Authors: M. Rossi, Serena Cattari, Sergio LagomarsinoAbstract:The seismic Performance-Based Assessment (PBA) of monumental buildings requires to consider safety and conservation objectives, including also the possible presence of artistic assets. In order to face these issues, the case study of the Great Mosque of Algiers is analysed in this paper: in fact, besides to be one of the remaining Almoradiv architecture and the oldest mosque of the city, it is also characterized by the presence of a mihrâb, a decorated arched niche that represents an interesting artistic asset to be included in the PBA. Within this context, particular attention has been paid to the choice of the most reliable modelling strategy for the application of the displacement approach in the PBA procedure, as a function of different possible seismic behaviours. In the case of Great Mosque both the current state of the building and a virtual strengthened condition are analysed. It is worth noting that, while in the current state the seismic behaviour of the asset is well described by a set of macroelements that may be analysed independently (through 2D models), in the second case the strengthening intervention leads to the adoption of a 3D global model (indeed, the roof bracing promotes a “box-type” behaviour). In the paper, the integrate use of three different modelling strategies of different complexity is discussed: the finite element model, the equivalent frame approach and the macro-block model. The results of nonlinear analyses performed (static and kinematic) constitute the main tool to interpret the seismic response of the asset, perform the PBA and address the choice on the rehabilitation decisions. These latter in this case are mainly affected by the occurrence of too high deformations in local portions of the building, including that in which the artistic asset is located.
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Seismic Performance-Based Assessment of “Gaioleiro” buildings
Engineering Structures, 2014Co-Authors: Ana G. Simões, Rita Bento, Serena Cattari, Sergio LagomarsinoAbstract:Abstract “Gaioleiro” buildings are unreinforced masonry buildings with flexible timber floors associated with the urban expansion of Lisbon at the end of the nineteenth century and beginning of the twentieth century. This paper presents the results from the seismic Performance-Based Assessment of a “Gaioleiro” building case study, assumed as a prototype representative of wide number of buildings. The Assessment was addressed to the global seismic response of the building, mainly governed by the in-plane capacity of the masonry walls, and to the local response, related to the activation of out-of-plane mechanisms of parts of the building. The global behaviour was determined by non-linear static analyses and the effects of some relevant modelling options were considered; in particular, parametric analyses were carried out taking into account the strength capacity of spandrel beams and the influence of the degree of connection between walls. The local behaviour was determined with limit non-linear kinematic analysis. The seismic Performance-Based Assessment was set by the comparison of the structural capacity, with reference to various limit states (as proposed in Eurocode 8), with the seismic demand for Lisbon, related to different return periods. Different approaches to define such limits on the capacity curve were assumed in order to discuss the reliability of criteria proposed in codes for the case of structures characterized by flexible floors.
John C Morris - One of the best experts on this subject based on the ideXlab platform.
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reliability of the washington university road test a performance based Assessment for drivers with dementia of the alzheimer type
JAMA Neurology, 1997Co-Authors: Linda A Hunt, Christopher F Murphy, David B Carr, Janet M Duchek, Virginia Buckles, John C MorrisAbstract:Objective: To assess the reliability and stability of a standardized road test for healthy aging people and those with dementia of the Alzheimer type (DAT). Design: A prospective study involving patients with DAT and age-matched healthy controls in which subjects' driving performance was evaluated by several raters in an initial and a follow-up road test. Setting: Urban medical school and urban highways and streets. Subjects: A convenience sample of 58 controls, 36 subjects with very mild DAT, and 29 subjects with mild DAT. Results: Analysis of road test ability of controls (2 subjects [3%] failed the test), very mild DAT subjects (7 subjects [19%] failed), and mild DAT subjects (12 subjects [41%] failed) disclosed a significant association between driving performance and dementia status (X 2 [4] =20.65 [N=123]; P Conclusions: Dementia adversely affects driving performance even in its mild stages, although some persons with DAT seem to drive safely for some time after disease onset. A traffic-interactive, Performance-Based road test that examines cognitive behaviors provides an accurate and reliable functional Assessment of driving ability.
Robert L. Linn - One of the best experts on this subject based on the ideXlab platform.
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performance based Assessment implications of task specificity
Educational Measurement: Issues and Practice, 2005Co-Authors: Robert L. Linn, Elizabeth BurtonAbstract:How generalizable are the scores from Performance-Based Assessments? How can we best increase the gener-alizability of results? What level of generalizability is needed for different testing purposes?
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Performance-Based Assessment: Lessons From the Health Professions:
Educational Researcher, 1995Co-Authors: David B. Swanson, Geoffrey R. Norman, Robert L. LinnAbstract:Performance-Based Assessment methods have been used in the health professions for centuries, and dozens of studies of their psychometric characteristics have been reported over the past several decades. During that period, the health professions have seen a variety of Performance-Based Assessment methods come and go, and some hard lessons have been learned from the many studies and frequent missteps. This article shares some of those lessons, using four Performance-Based Assessment methods as examples: written clinical simulations (more commonly termed patient management problems), computer-based clinical simulations, oral examinations, and standardized patients (“live” simulations).
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Introduction: Policy and Validity Prospects for Performance-Based Assessment
Journal for the Education of the Gifted, 1994Co-Authors: Eva L. Baker, Harold F. O'neil, Robert L. LinnAbstract:High interest in Performance-Based Assessment of educational achievement is indicated by recent conferences, special journal issues, and national television coverage. The president's and governors' educational goals reflect the central role of Assessment in reform. A prominent view is that changes in Assessment, using more complex, meaningful, and integrative performance tasks, will improve education. New Assessments present challenges to the curriculum, teaching practices, and presentation of student achievement information to policymakers and to the public. Sufficient high-quality Assessments must be available before their impact on educational reform can be assessed. Although interest in Performance-Based Assessment is high, our knowledge about its quality is low. Moreover, few psychometric templates exist to guide the technical practices of Assessment developers.
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complex performance based Assessment expectations and validation criteria
Educational Researcher, 1991Co-Authors: Robert L. Linn, Eva L. Baker, Stephen B DunbarAbstract:In recent years there has been an increasing emphasis on Assessment results, as well as increasing concern about the nature of the most widely used forms of student Assessment and uses that are made of the results. These conflicting forces have helped create a burgeoning interest in alternative forms of Assessments, particularly complex, Performance-Based Assessments. It is argued that there is a need to rethink the criteria by which the quality of educational Assessments are judged, and a set of criteria that are sensitive to some of the expectations for Performance-Based Assessments is proposed.
Linda A Hunt - One of the best experts on this subject based on the ideXlab platform.
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reliability of the washington university road test a performance based Assessment for drivers with dementia of the alzheimer type
JAMA Neurology, 1997Co-Authors: Linda A Hunt, Christopher F Murphy, David B Carr, Janet M Duchek, Virginia Buckles, John C MorrisAbstract:Objective: To assess the reliability and stability of a standardized road test for healthy aging people and those with dementia of the Alzheimer type (DAT). Design: A prospective study involving patients with DAT and age-matched healthy controls in which subjects' driving performance was evaluated by several raters in an initial and a follow-up road test. Setting: Urban medical school and urban highways and streets. Subjects: A convenience sample of 58 controls, 36 subjects with very mild DAT, and 29 subjects with mild DAT. Results: Analysis of road test ability of controls (2 subjects [3%] failed the test), very mild DAT subjects (7 subjects [19%] failed), and mild DAT subjects (12 subjects [41%] failed) disclosed a significant association between driving performance and dementia status (X 2 [4] =20.65 [N=123]; P Conclusions: Dementia adversely affects driving performance even in its mild stages, although some persons with DAT seem to drive safely for some time after disease onset. A traffic-interactive, Performance-Based road test that examines cognitive behaviors provides an accurate and reliable functional Assessment of driving ability.