Letteratura scientifica selezionata sul tema "Sensitivity metric"
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Articoli di riviste sul tema "Sensitivity metric":
1
Hill, Allen, e Julie Nantel. "Sensitivity of discrete symmetry metrics: Implications for metric choice". PLOS ONE 17, n. 5 (19 maggio 2022): e0268581. http://dx.doi.org/10.1371/journal.pone.0268581.
Abstract (sommario):
Gait asymmetry is present in several pathological populations, including those with Parkinson’s disease, Huntington’s disease, and stroke survivors. Previous studies suggest that commonly used discrete symmetry metrics, which compare single bilateral variables, may not be equally sensitive to underlying effects of asymmetry, and the use of a metric with low sensitivity could result in unnecessarily low statistical power. The purpose of this study was to provide a comprehensive assessment of the sensitivity of commonly used discrete symmetry metrics to better inform design of future studies. Monte Carlo simulations were used to estimate the statistical power of each symmetry metric at a range of asymmetry magnitudes, group/condition variabilities, and sample sizes. Power was estimated by repeated comparison of simulated symmetric and asymmetric data with a paired t-test, where the proportion of significant results is equivalent to the power. Simulation results confirmed that not all common discrete symmetry metrics are equally sensitive to reference effects of asymmetry. Multiple symmetry metrics exhibit equivalent sensitivities, but the most sensitive discrete symmetry metric in all cases is a bilateral difference (e.g. left—right). A ratio (e.g. left/right) has poor sensitivity when group/condition variability is not small, but a log-transformation produces increased sensitivity. Additionally, two metrics which included an absolute value in their definitions showed increased sensitivity when the absolute value was removed. Future studies should consider metric sensitivity when designing analyses to reduce the possibility of underpowered research.
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Torn, Ryan D., e Gregory J. Hakim. "Ensemble-Based Sensitivity Analysis". Monthly Weather Review 136, n. 2 (1 febbraio 2008): 663–77. http://dx.doi.org/10.1175/2007mwr2132.1.
Abstract (sommario):
Abstract The sensitivity of forecasts to observations is evaluated using an ensemble approach with data drawn from a pseudo-operational ensemble Kalman filter. For Gaussian statistics and a forecast metric defined as a scalar function of the forecast variables, the effect of observations on the forecast metric is quantified by changes in the metric mean and variance. For a single observation, expressions for these changes involve a product of scalar quantities, which can be rapidly evaluated for large numbers of observations. This technique is applied to determining climatological forecast sensitivity and predicting the impact of observations on sea level pressure and precipitation forecast metrics. The climatological 24-h forecast sensitivity of the average pressure over western Washington State shows a region of maximum sensitivity to the west of the region, which tilts gently westward with height. The accuracy of ensemble sensitivity predictions is tested by withholding a single buoy pressure observation from this region and comparing this perturbed forecast with the control case where the buoy is assimilated. For 30 cases, there is excellent agreement between these forecast differences and the ensemble predictions, as measured by the forecast metric. This agreement decreases for increasing numbers of observations. Nevertheless, by using statistical confidence tests to address sampling error, the impact of thousands of observations on forecast-metric variance is shown to be well estimated by a subset of the O(100) most significant observations.
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Neralić, Luka, e Richard E. Wendell. "Generalized tolerance sensitivity and DEA metric sensitivity". Croatian Operational Research Review 6, n. 1 (30 marzo 2015): 169–80. http://dx.doi.org/10.17535/crorr.2015.0014.
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Mishra, Siddhartha, Nicholas Monath, Michael Boratko, Ariel Kobren e Andrew McCallum. "An Evaluative Measure of Clustering Methods Incorporating Hyperparameter Sensitivity". Proceedings of the AAAI Conference on Artificial Intelligence 36, n. 7 (28 giugno 2022): 7788–96. http://dx.doi.org/10.1609/aaai.v36i7.20747.
Abstract (sommario):
Clustering algorithms are often evaluated using metrics which compare with ground-truth cluster assignments, such as Rand index and NMI. Algorithm performance may vary widely for different hyperparameters, however, and thus model selection based on optimal performance for these metrics is discordant with how these algorithms are applied in practice, where labels are unavailable and tuning is often more art than science. It is therefore desirable to compare clustering algorithms not only on their optimally tuned performance, but also some notion of how realistic it would be to obtain this performance in practice. We propose an evaluation of clustering methods capturing this ease-of-tuning by modeling the expected best clustering score under a given computation budget. To encourage the adoption of the proposed metric alongside classic clustering evaluations, we provide an extensible benchmarking framework. We perform an extensive empirical evaluation of our proposed metric on popular clustering algorithms over a large collection of datasets from different domains, and observe that our new metric leads to several noteworthy observations.
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Gamboa, Fabrice, Thierry Klein, Agnès Lagnoux e Leonardo Moreno. "Sensitivity analysis in general metric spaces". Reliability Engineering & System Safety 212 (agosto 2021): 107611. http://dx.doi.org/10.1016/j.ress.2021.107611.
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Chu, Xiu-qin. "Contrast-sensitivity-function-based clutter metric". Optical Engineering 51, n. 6 (5 giugno 2012): 067003. http://dx.doi.org/10.1117/1.oe.51.6.067003.
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Jude Chukwura Obi. "A comparative study of several classification metrics and their performances on data". World Journal of Advanced Engineering Technology and Sciences 8, n. 1 (28 febbraio 2023): 308–14. http://dx.doi.org/10.30574/wjaets.2023.8.1.0054.
Abstract (sommario):
Six classification metrics namely, Accuracy, Precision, Recall (Sensitivity), Specificity, F1-Score and Area Under the Curve have been studied in this work. A classification model based on the Support Vector Machine, was used to obtain a confusion matrix, which provided the needed information for calculating the different classification metrics. Twenty different datasets were used to assess the performances of the classification metrics. Accuracy and Area Under the Curve are the two metrics that consistently gave a classification result given each dataset used in the study. Although accuracy appears to be marginally better that AUC, it was discovered that in some cases where sensitivity is zero, accuracy yielded a high correct classification result. This goes further to implying that prior to choosing accuracy as a preferred metric for classification, investigation should be carried out to find out what sensitivity and specificity are. Where there are high values for sensitivity and specificity, the study shows that a choice of accuracy as a preferred classification metric leads to a high percentage of correct classification result.
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Paiva, João R. B., Alana S. Magalhães, Pedro H. F. Moraes, Júnio S. Bulhões e Wesley P. Calixto. "Stability Metric Based on Sensitivity Analysis Applied to Electrical Repowering System". Energies 14, n. 22 (22 novembre 2021): 7824. http://dx.doi.org/10.3390/en14227824.
Abstract (sommario):
Stability metrics are used to quantify a system’s ability to maintain equilibrium under disturbances. We did not identify the proposition of a stability metric using sensitivity analysis within the literature. This work proposes a system stability metric and its application to an electrical repowering system. The methodology for applying the proposed metric comprises: (i) system parameters sensitivity analysis and spider diagram construction, (ii) determining the array containing the line segments inclination angles of each spider diagram curve, and (iii) stability calculation using the array mean and maximum inclination value of a line segment. After simulating the model built for the electrical repowering system and applying the methodology, we obtain results regarding the sensitivity indices and stability values of system inputs relative to their outputs, considering the original system and with reduced parameters. Using the stability study, it was possible to determine different stability categories for the system parameters, which indicates the need for different analysis levels.
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Lehuta, Sigrid, Stéphanie Mahévas, Pascal Le Floc’h e Pierre Petitgas. "A simulation-based approach to assess sensitivity and robustness of fisheries management indicators for the pelagic fishery in the Bay of Biscay". Canadian Journal of Fisheries and Aquatic Sciences 70, n. 12 (dicembre 2013): 1741–56. http://dx.doi.org/10.1139/cjfas-2013-0066.
Abstract (sommario):
Indicators are widely promoted as means to monitor ecosystem status or to evaluate fisheries management performance. “Which indicators are most relevant as decision-support tools in fisheries management?” still remains a topical question. Indicators should be metrics related to fish populations and fleets and should be sensitive to management strategies. However, given the complexity of the processes involved, it is often difficult to unequivocally interpret variations in metrics. A simulation approach was used to study metric properties and to identify robust and relevant fishery indicators. By applying sensitivity analysis methods, simulation designs were built that cross a variety of management scenarios and uncertainty hypotheses. Bio-economic outputs were simulated using a mechanistic model (ISIS-Fish), and their properties were statistically analyzed. This approach was applied to the pelagic fishery of the Bay of Biscay. The analysis of metric properties highlighted the major factors driving variations in each metric and identified the important sources of uncertainty that need to be reduced to allow the use of metrics as indicators. Although very few metrics gave robust indications of management performance, sensitivity indices evidenced how management performances could be improved, and spatially disaggregated metrics provided insights into the mechanisms underlying management performance.
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Jensen, Hector A., e Abdon E. Sepulveda. "Design Sensitivity Metric for Structural Dynamic Response". AIAA Journal 36, n. 9 (settembre 1998): 1686–93. http://dx.doi.org/10.2514/2.572.
Tesi sul tema "Sensitivity metric":
1
Milne, Andrew Steven. "A benchmark fault coverage metric for analogue circuits". Thesis, University of Huddersfield, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.285669.
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Mcnamara, Thomas. "Analysis and metric development for the study of viscoelastic thin films utilising a quartz crystal microbalance". Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/analysis-and-metric-development-for-the-study-of-viscoelastic-thin-films-utilising-a-quartz-crystal-microbalance(b82fec4b-728d-43e6-842b-0941f21be200).html.
Abstract (sommario):
The aim of this thesis is the creation of a set of tools for the quartz crystal microbalance (QCM-D) that aid in the measurement and quantification of soft viscoelastic thin films and experimental work demonstrating their use. The QCM-D is an acoustic technique that monitors structural changes occurring at the sensor's surface via changes in the sensor's resonance frequency and the rate of mechanical energy loss (dissipation). As a first approximation, the frequency shifts are used to measure mass changes on the sensor's surface, and dissipation shifts used to quantify changes in the rigidity of the film. Use of the QCM-D responses in this manner requires that the film is acoustically thin and rigid, limiting its application to soft films. To quantify mass and viscoelastic changes using the QCM-D, soft films either need to be approximated to a thin, rigid layer, or the frequency and dissipation responses modelled using a viscoelastic model. Such an approximation leads to the encompassment of all the viscoelastic properties into the single dissipation measurement in addition to potentially introducing errors in mass calculations. Existing commercial software allows for the deconvolution of film parameters such as the shear modulus and viscosity by fitting experimental data to a viscoelastic model. This analysis can only be done after the experimental data is collected however, and provides no guidance on future experiments, also commonly requiring an initial estimate of the parameter values under investigation. I have developed an experimental optimisation tool, termed the total parameter matrix sensitivity (TPM-sensitivity). It is defined as the Jacobian determinant of the QCM-D responses with respect to the parameters under investigation, e.g. the film's height, density, viscosity and shear modulus and the bulk fluid's density and viscosity. TPM-sensitivity is a measure of how readily resolvable and separable the film and bulk are when analysing the QCM-D responses. This enables the user to select the most mathematically important harmonics, and using this I was able to experimentally resolve the viscoelastic information of a soft film using frequency responses alone. I have also defined a classification system which categorises the QCM-D responses relative to a perfectly rigid and thin film. This provides guidance on the level of analysis required to gain information about the film parameters, with the limitations of commonly applied rules of thumb also demonstrated. Examples using these computational tools and metrics are also presented with data I obtained experimentally and from the literature. Of the experimental investigations, the curing process of a bulk elastomer is of particular importance due to the film being both soft and acoustically thick, demonstrating QCM-D use for a film not complying to either of thecommonly used film approximations.
3
Saha, Abhijoy. "A Geometric Framework for Modeling and Inference using the Nonparametric Fisher–Rao metric". The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1562679374833421.
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Dell'Oca, Aronne, Monica Riva e Alberto Guadagnini. "Moment-based metrics for global sensitivity analysis of hydrological systems". COPERNICUS GESELLSCHAFT MBH, 2017. http://hdl.handle.net/10150/626437.
Abstract (sommario):
We propose new metrics to assist global sensitivity analysis, GSA, of hydrological and Earth systems. Our approach allows assessing the impact of uncertain parameters on main features of the probability density function, pdf, of a target model output, y. These include the expected value of y, the spread around the mean and the degree of symmetry and tailedness of the pdf of y. Since reliable assessment of higher-order statistical moments can be computationally demanding, we couple our GSA approach with a surrogate model, approximating the full model response at a reduced computational cost. Here, we consider the generalized polynomial chaos expansion (gPCE), other model reduction techniques being fully compatible with our theoretical framework. We demonstrate our approach through three test cases, including an analytical benchmark, a simplified scenario mimicking pumping in a coastal aquifer and a laboratory-scale conservative transport experiment. Our results allow ascertaining which parameters can impact some moments of the model output pdf while being uninfluential to others. We also investigate the error associated with the evaluation of our sensitivity metrics by replacing the original system model through a gPCE. Our results indicate that the construction of a surrogate model with increasing level of accuracy might be required depending on the statistical moment considered in the GSA. The approach is fully compatible with (and can assist the development of) analysis techniques employed in the context of reduction of model complexity, model calibration, design of experiment, uncertainty quantification and risk assessment.
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Tucker, Christopher John. "Performance metrics for network intrusion systems". Thesis, University of Plymouth, 2013. http://hdl.handle.net/10026.1/1547.
Abstract (sommario):
Intrusion systems have been the subject of considerable research during the past 33 years, since the original work of Anderson. Much has been published attempting to improve their performance using advanced data processing techniques including neural nets, statistical pattern recognition and genetic algorithms. Whilst some significant improvements have been achieved they are often the result of assumptions that are difficult to justify and comparing performance between different research groups is difficult. The thesis develops a new approach to defining performance focussed on comparing intrusion systems and technologies. A new taxonomy is proposed in which the type of output and the data scale over which an intrusion system operates is used for classification. The inconsistencies and inadequacies of existing definitions of detection are examined and five new intrusion levels are proposed from analogy with other detection-based technologies. These levels are known as detection, recognition, identification, confirmation and prosecution, each representing an increase in the information output from, and functionality of, the intrusion system. These levels are contrasted over four physical data scales, from application/host through to enterprise networks, introducing and developing the concept of a footprint as a pictorial representation of the scope of an intrusion system. An intrusion is now defined as “an activity that leads to the violation of the security policy of a computer system”. Five different intrusion technologies are illustrated using the footprint with current challenges also shown to stimulate further research. Integrity in the presence of mixed trust data streams at the highest intrusion level is identified as particularly challenging. Two metrics new to intrusion systems are defined to quantify performance and further aid comparison. Sensitivity is introduced to define basic detectability of an attack in terms of a single parameter, rather than the usual four currently in use. Selectivity is used to describe the ability of an intrusion system to discriminate between attack types. These metrics are quantified experimentally for network intrusion using the DARPA 1999 dataset and SNORT. Only nine of the 58 attack types present were detected with sensitivities in excess of 12dB indicating that detection performance of the attack types present in this dataset remains a challenge. The measured selectivity was also poor indicting that only three of the attack types could be confidently distinguished. The highest value of selectivity was 3.52, significantly lower than the theoretical limit of 5.83 for the evaluated system. Options for improving selectivity and sensitivity through additional measurements are examined.
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Esteves, Sara Marina Cardoso. "Sensitivity of freshwater diatoms to herbicides and metals: geography, phylogeny and biochemistry". Master's thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/21091.
Abstract (sommario):
Mestrado em Toxicologia e EcotoxicologiaOs ambientes aquáticos estão contaminados por muitos poluentes, incluindo pesticidas e metais. Tem sido demonstrado que as diatomáceas são sensíveis a tais micropoluentes. Estudos anteriores demonstraram grupos monofiléticos de diatomáceas com tolerância homogénea a herbicidas, pressupondo-se que a sensibilidade de um determinado grupo taxonómico é homogénea. Esta hipótese foi investigada com Nitzschia palea e Achnanthidium spp, espécies com sensibilidades distintas à poluição, bem como a diversidade filogenética, taxonómica e intra-específica. A hipótese original de sensibilidade do grupo monofilético aos herbicidas também foi testada. Trinta e nove estirpes, incluindo 11 de Achnanthidium spp e 14 de N. palea, foram submetidas a ensaios biológicos para avaliar a sua sensibilidade aos herbicidas atrazina, terbutrina, diurão e isoproturão. As estirpes de N. palea também foram testadas quanto à sua sensibilidade a metais, tais como o cádmio e cobre. Culturas mono-específicas foram expostas a estas substâncias durante 96 horas, após as quais se avaliou a inibição do crescimento. A sensibilidade das estirpes foi combinada com a sua filogenia para verificar a existência de uma ligação entre ambos. Para N. palea e Achnanthidium spp, a origem das estirpes também foi ponderada para estabelecer se a distância geográfica desempenhava um papel relevante na sensibilidade de estirpes de uma mesma espécie. Numa segunda fase, uma estirpe sensível e uma tolerante de N. palea foram expostas a atrazina, diurão, cádmio e cobre, e analisadas a nível bioquímico. Observou-se uma correlação entre a sensibilidade das espécies para todos os pesticidas, com excepção da atrazina. Quanto às espécies analisadas intraspecificamente, não se encontrou qualquer correlação para as estirpes de N. palea e Achnantidium spp quando expostas à atrazina, no entanto, para Achnantidium spp exposto aos outros herbicidas e N. palea exposta a metais verificou-se correlação entre isolados da mesma espécie. A distância geográfica entre isolados não contribuiu significativamente para a variação observada na sensibilidade, com excepção dos ensaios com metais. Ao nível bioquímico, o isolado tolerante e o sensível apresentaram diferentes estratégias, não havendo um parâmetro que se destacasse como possível biomarcador.
Aquatic environments are impacted by many pollutants, including pesticides and metals. It has been shown that diatoms are sensitive to such micropollutants. Previous studies have shown clades of diatoms with homogeneous herbicide tolerance, making the assumption that a given taxon’s sensitivity is homogeneous. This hypothesis was investigated with Nitzschia palea and Achnanthidium spp, species with distinct sensitivity to pollution, as well as taxonomic and intraspecific phylogenetic diversity. The original clade sensitivity to herbicides hypothesis was also tested. Thirty-nine strains, comprising 11 of Achnanthidium spp and 14 of N. palea, were bioassayed to assess their sensitivity to the herbicides atrazine, terbutryn, diuron and isoproturon. The N. palea strains were also tested for their sensitivity to cadmium and copper. Single strain cultures were exposed to these substances for 96 hours, after which growth inhibition was assessed. Strains’ sensitivity was matched to its phylogeny to verify the existence of a link between both. For N. palea and Achnanthidium spp, strains’ origin was also weighted in to establish if the geographic distance played a role in the sensitivity of strains from the same species. In a second phase, one sensitive and one tolerant N. palea strain were chosen to be exposed to atrazine, diuron, cadmium and copper and analysed at a biochemical level. A correlation between species’ sensitivity was observed for all the pesticides, except for atrazine. As for the species analysed intraspecifically, while no correlation was found for the N. palea strains or Achnanthidium spp when exposed to atrazine, it was present for Achnanthidium spp, when exposed to the other herbicides and N. palea exposed to metals. Geographic distance among each strain isolates did not account significantly for the sensitivity variation observed, with exception of the metal assays. At a biochemical level, tolerant and sensitive strain often presented different strategies, with no parameter standing out as a potential biomarker
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Koné, Tchoya Florence. "Contribution à la démonstration de la sécurité du véhicule autonome, basée sur une stratégie de génération de scénarios, modélisée par niveaux d’abstraction et orientée par la sensibilité du VA, pour une validation par simulation". Electronic Thesis or Diss., Université de Lorraine, 2021. http://www.theses.fr/2021LORR0182.
Abstract (sommario):
Cette thèse CIFRE, réalisé au sein de Stellantis, fournit une stratégie de génération de scénarios, modélisée par niveaux d’abstraction et orientée par la sensibilité du VA, pour une validation par simulation. Ce travail s’inscrit dans le périmètre du standard ISO PAS 21448 /SOTIF (Safety Of The Intended Functionality). Pour ce faire, la démarche suivie s’articule autour de cinq contributions : (1) Une analyse de l’architecture fonctionnelle du VA et la mise en évidence des challenges liés à la validation de sa sécurité : aspects normatifs, chaines de simulation, la présence d’incertitude dans l’environnement opérationnel du VA. (2) La proposition d’un cadre conceptuel (modèle de connaissance) sur lequel s’appuiera la méthodologie de génération des scénarios qui sera proposée par la suite. (3) Une synthèse sur les indicateurs manipulés dans la littérature, ainsi que ceux, que nous retiendrons dans notre stratégie de génération finale dont notamment l’indicateur de sensibilité. Elle donne également une structure du système de génération des scénarios et de validation par simulation de la sécurité du VA, ainsi que la manière dont les indicateurs seront exploités dans cette structure. (4) La proposition d’une heuristique de génération des scénarios et l’estimation de l’indicateur de risque associé au VA. Cette quatrième contribution, s’appuie sur les éléments développés dans les contributions précédentes : le modèle conceptuel proposé (contribution 2), la structure du système de génération et de validation ainsi que les indicateurs associés (contribution 3). (5) Enfin, la dernière contribution est une implémentation des propositions précédentes via un cas d’étude.Mots clés : Véhicule Autonome (VA), SOTIF (Safety Of The Intended Functionality), Limitation de performances fonctionnelles, Insuffisances fonctionnelles, Scénarios critiques, Métrique de sensibilité, Stratégie de génération de scénarios, Validation par simulationThis CIFRE thesis, carried out within Stellantis, provides a scenario generation strategy, modelled by levels of abstraction and oriented by the sensitivity of the AV, for a simulation-based validation process. This work is within the scope of the ISO PAS 21448 /SOTIF (Safety Of The Intended Functionality) standard.To do this, the approach followed is based on five contributions: (1) An analysis of the functional architecture of the AV and the highlighting of the challenges related to its safety validation: normative aspects, simulation chains, the presence of uncertainty in the operational environment of the AV. (2) The proposal of a conceptual framework (knowledge model) on which the scenario generation methodology to be proposed later will be based. (3) A summary of the indicators used in the literature, as well as those that we will use in our final generation strategy, including the sensitivity indicator. It also gives a structure of the system of scenario generation and simulation based validation of the safety of the AV, as well as the way in which the indicators will be exploited in this structure. (4) The proposal of a scenario generation heuristic and the estimation of the risk indicator associated with the AV. This fourth contribution is based on the elements developed in the previous contributions: the proposed conceptual model (contribution 2), the structure of the generation and validation system and the associated indicators (contribution 3). (5) Finally, the last contribution is an implementation of the previous proposals via a case study.Keywords: Autonomous Vehicle (AV), Safety Of The Intended Functionality (SOTIF), Functional performance limitation, Functional insufficiencies, Critical scenarios, Sensitivity metric, Scenarios generation strategy, Simulation-based Validation process
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Capelletti, Raquel Vannucci 1978. "Avaliação da atividade de biocidas em biofilmes formados a partir de fluido de corte utilizado na usinagem de metais". [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266382.
Abstract (sommario):
Orientador: Angela Maria Moraes, Silvia Yuko EguchiDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica
Made available in DSpace on 2018-08-07T08:16:36Z (GMT). No. of bitstreams: 1 Capelletti_RaquelVannucci_M.pdf: 647054 bytes, checksum: c35c09b03ca4ad293e07ecb39071b2b4 (MD5) Previous issue date: 2006
Resumo: Biofilmes são associações de espécies microbianas interdependentes, funcionando de forma complexa e coordenada como mecanismo de colonização de superfícies. Quando indesejavelmente instalados em uma planta industrial, os biofilmes contribuem para a contaminação de muitas áreas de processo, pois representam fontes de liberação e disseminação de microrganismos que podem deteriorar produtos, causando prejuízos financeiros e retrabalho, situação esta que pode ser prevenida e/ou controlada. No entanto, sua remoção representa um desafio, principalmente no que diz respeito à determinação do tipo e da dosagem adequada de biocida para este fim. Freqüentemente, a abordagem para a resolução deste problema é empírica. O presente trabalho teve por objetivo desenvolver um protocolo reprodutível para a formação de biofilmes em laboratório a partir de consórcios microbianos e a avaliação de sua susceptibilidade aos biocidas mais recomendados. Foram utilizados como inóculo microrganismos presentes em fluido de corte proveniente da indústria de usinagem de metais, por ser este um dos principais segmentos industriais sujeitos à formação de biofilmes. A metodologia adotada foi a recomendada para a utilização do dispositivo MBEC¿, um aparato amplamente empregado nas áreas médica e odontológica para o estudo de patógenos isolados, enfocando-se no estudo a influência de variáveis como tipo e concentração do inóculo, tempo e temperatura de incubação para a obtenção do biofilme e tempo de sonicação para desagregação do biofilme. Os resultados obtidos mostraram que o procedimento estabelecido para a obtenção in vitro de biofilmes foi plenamente satisfatório utilizando o inóculo constituído do fluido contaminado, e que tais biofilmes foram eficientemente erradicados na presença de biocidas não-oxidantes em concentrações 12 vezes superiores às normalmente empregadas. A temperatura de 25 ou 35°C e período de 48 h de incubação devem ser empregados para o desenvolvimento do biofilme e, para sua desagregação, recomenda-se efetuar a sonicação por 30 minutos. O isolamento das culturas puras a partir do consórcio microbiano original da amostra de fluido de corte, e o estudo dos biofilmes formados a partir das cepas isoladas não resultou na formação de biofilmes com número suficiente de células aderidas, indicando a ocorrência de seleção de cepas sem grande capacidade de adesão e de cepas fastidiosas e até mesmo não-cultiváveis, que requerem condições especiais de cultivo e que são essenciais para corresponder à flora original da amostra na formação do biofilme
Abstract: Biofilms are complex structures consisting of interdependent microbial species associations acting as surface colonization mechanism. Once undesirably installed at an industrial plant, biofilms contribute to contaminate many process areas, because they represent sources of microbial release and dissemination, which can deteriorate products, causing financial damages and work rebdoing, undesirable situations that can be controlled and/or prevented. However, biofilm removal represents a challenge, mainly referring to biocide type and dosage selection. Frequently, empiric approaches are used to solve this problem. The aim of the present work was to develop an in vitro experimental protocol for biofilm formation employing microbial consortia and to evaluate its susceptibility to recommended biocides. Microrganisms contaminating cutting fluid used in metalworking industry were employed as inoculum, since this is one of the main industrial segments subject to frequent biofilm formation. The adopted methodology was the recommended for the use of the MBEC¿ device thoroughly employed in the medical and dentistry areas for the study of isolated pathogenic microorganisms, and the study of the influence of variables such as inoculum type and concentration, incubation time and temperature for biofilm development, and sonication time for disaggregating the biofilms were focused. The achieved results showed that the established procedure for in vitro biofilm development was fully satisfactory when using the inoculum consisting of contaminated cutting fluid and that these biofilms were efficiently eradicated using non-oxidant biocide concentrations twelve times superior to those usually employed. Incubation temperature of 25 or 35°C and 48 h time period should be employed for biofilm development, while a 30 minute sonication period is recommended for disaggregating the biofilm. The isolation of the microorganisms in consortium, in the same cutting fluid, and their use for biofilm formation resulted in insufficient adhered cell numbers, indicating the occurrence of unadherent cells as well as unculturable strains, which require special culture conditions, and are essential for to reflect the original flora in the biofilm formation
Mestrado
Desenvolvimento de Processos Biotecnologicos
Doutor em Engenharia Química
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Caetano, Ana Luísa Neto. "Derivation of soil screening values for metals in Portuguese natural soil". Doctoral thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/13764.
Abstract (sommario):
Doutoramento em BiologiaThe increasing human activity has been responsible by profound changes and a constinuos degradation of the soil compartment in all the European territory. Some European policies are appearing focusing soil’s protection and the management of contaminated sites, in order to recover land for other uses. To regulate the risk assessment and the management of contaminated soils, many European member states adopted soil guideline values, as for example soil screnning values (SSV).These values are particularly useful for the the first tier of the Ecological Risk Assessment (ERA) processes of contaminated sites,especially for a first screening of sites requiring a more site-specific evaluation. Hence, the approriate definition of regional SSVs will have relevant economic impacts in the management of contaminated sites. Portugal is one of European Member States that still lack these soil guideline values. In this context, this study gaves a remarkable contribution in the generation of ecotoxicological data for soil microbiological parameters, terrestrial plants and invertebrates for the derivation of SSVs for uranium (U), cadmium (Cd) and copper (Cu), using a Portuguese natural soil, representative of a dominant type of soil in the Portuguese territory. SSVs were derived based on two methods proposed by the the Technical Guidance Document for Risk Assessment of the European Commission; namely the assessment factor method (AF) and the species sensitivity distribution (SSD) method (with some adaptations). The outputs of both methods were compared and discussed. Further, this study laid the foundation for a deeper reflection about the cut-off (hazard concentration for a given percentage of species - HCps) to be estimated from the SSDs, and to be selected for the derivation of SSVs, with the adequate level of protection. It was proven that this selection may vary for different contaminants, however a clear justification should be given, in each case. The SSvs proposed in this study were for: U (151.4 mg U kg-1dw), Cd (5.6 mg Cd kg-1dw), and Cu (58.5 mg Cu kg-1dw) These values should now be tested for their descriminating power of soils with different levels of contamination. However, this studies clarifies the approach that should be followed for the derivation of SSVs for other metals and organic contaminants, and for other dominant types of Portuguese natural soils.
O aumento das atividades humanas tem sido responsável por mudanças profundas e por uma degradação contínua do compartimento solo, em todo o território Europeu. Em resposta a este problema, algumas políticas Europeias estão agora a emergir orientadas especificamente para a proteção do solo e para a gestão das áreas contaminadas, a fim de recuperar os solos degradados para outros usos. Para regulamentar a avaliação de risco e a gestão de solos contaminados, muitos Estados-Membros Europeus adoptaram valores de qualidade do solo, como por exemplo os “valores de rastreio ou triagem” (do inglês: soil screening values ou SSVs). Estes valores são particularmente úteis para a primeira etapa dos processos de avaliação de risco ecológico (ARE) de locais contaminados, especialmente para um primeiro rastreio dos locais, destinado a separar aqueles em que os riscos são claramente reduzidos daqueles que exigem uma avaliação mais específica e aprofundada para o local. Assim, a definição de SSVs regionais terá impactos económicos relevantes na gestão dos locais contaminados. Portugal é um dos Estados-Membros Europeus que ainda não definiu SSVs. Neste contexto, este estudo dá uma notável contribuição na geração de dados ecotoxicológicos para parâmetros microbiológicos do solo, plantas terrestres e invertebrados necessários para a obtenção de SSVs para urânio (U), cádmio (Cd) e cobre (Cu), utilizando um solo natural Português, representante de um tipo dominante de solo existente no território nacional. Assim, foram obtidos SSVs para os metais referidos com base em dois métodos propostos pelo Documento de Orientação Técnica para Avaliação de Riscos da Comissão Europeia, nomeadamente o método dos factores de avaliação (do inglês: assessment factors ou AF) e o método probabilístico da distribuição da sensibilidade espécies (do inglês: species sensitivity distributions ou SSDs) (com algumas adaptações). Os resultados dos dois métodos foram comparados e discutidos. Além disso, este estudo lançou as bases para uma reflexão mais profunda sobre o ponto de corte (concentração de risco para uma determinada percentagem de espécies) a ser estimado a partir das distribuições de sensibilidade das espécies (SSDs), e para ser selecionado para a obtenção de SSVs, com o nível adequado de proteção. Neste estudo foi comprovado que esta seleção pode variar para diferentes metais ou outros contaminantes, no entanto, uma justificação clara deve ser dada, em cada caso. Os SSvs propostos neste estudo foram de: U (151,4 mg U kg- 1ms ), Cd (5,6 mg Cd kg- 1ms ) e Cu ( 58,5 mg Cu kg- 1 ms) Estes valores devem agora ser testados quanto à sua capacidade para descriminar solos com diferentes níveis de contaminação. No entanto, este estudo esclarece e sugere a abordagem que deve ser seguida para a derivação de SSVs para outros metais e contaminantes orgânicos, e para outros tipos dominantes de solos naturais portugueses.
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Bai, Kuang. "Directional constraint qualifications and optimality conditions with application to bilevel programs". Thesis, 2020. http://hdl.handle.net/1828/11939.
Abstract (sommario):
The main purpose of this dissertation is to investigate directional constraint qualifications and necessary optimality conditions for nonsmooth set-constrained mathematical programs.
First, we study sufficient conditions for metric subregularity of the set-constrained system. We introduce the directional version of the quasi-/pseudo-normality as a sufficient condition for metric subregularity, which is weaker than the classical quasi-/pseudo-normality, respectively. Then we apply our results to complementarity and Karush-Kuhn-Tucker systems.
Secondly, we study directional optimality conditions of bilevel programs. It is well-known that the value function reformulation of bilevel programs provides equivalent single-level optimization problems， which are nonsmooth and never satisfy the usual constraint qualifications such as the Mangasarian-Fromovitz constraint qualification (MFCQ). We show that even the first-order sufficient condition for metric subregularity (which is generally weaker than MFCQ) fails at each feasible point of bilevel programs. We introduce the directional Clarke calmness condition and show that under the directional Clarke calmness condition, the directional necessary optimality condition holds. We perform directional sensitivity analysis of the value function and propose the directional quasi-normality as a sufficient condition for the directional Clarke calmness.Graduate
2021-07-07
Libri sul tema "Sensitivity metric":
1
Kim, Young Sam. The sensitivity of observed trading volume reactions to the choice of trading volume reaction metric. [Urbana, Ill.]: College of Commerce and Business Administration, University of Illinois at Urbana-Champaign, 1991.
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D’Orsi, Carl. Breast Imaging Reporting and Data System (BI-RADS). A cura di Christoph I. Lee, Constance D. Lehman e Lawrence W. Bassett. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780190270261.003.0005.
Abstract (sommario):
This chapter, devoted to the Breast Imaging Reporting and Data System (BI-RADS), describes the standardized language applied to findings in mammography, breast ultrasound, and breast MRI. BI-RADS terms most frequently used are described, and most are illustrated by figures. In addition, the rules for a facility and radiologist audit are described, with definitions of true positive (TP), false positive (FP), true negative (TN), and false negative (FN) findings. Sensitivity (Se), specificity (Sp), positive predictive values 1, 2, and 3 (PPV1, 2, 3), and cancer detection rate are defined. An example of an audit is provided to clarify the use of these metrics.
3
Rose, Adam, Dan Wei e Antonio Bento. Equity Implications of the COP21 Intended Nationally Determined Contributions to Reduce Greenhouse Gas Emissions. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198813248.003.0004.
Abstract (sommario):
This chapter examines the equity implications of the “bottom-up” approach to climate change negotiations by analyzing the individual country unconditional greenhouse gas reduction pledges specified in the COP21 Agreement of 2015. It compares the implications before and after emissions trading in terms of the standard equity metrics of the Gini coefficient and Atkinson index for three major countries/regions: the European Union, China, and California. The chapter adapts a nonlinear programming model well suited to this purpose that determines the equilibrium emissions allowance price, mitigation costs, and allowance purchases and sales from trading. It also tests the sensitivity of the results to macroeconomic conditions and technological change. The findings are that the pledges made at COP21 reflect substantial inequality in general and run counter to most equity principles. They are definitely a major departure from the Egalitarian, Vertical, and Rawlsian equity principles proposed for many years by developing countries.
Capitoli di libri sul tema "Sensitivity metric":
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Curgus, Jadranka A., Son T. Vuong e Jinsong Zhu. "Sensitivity analysis of the metric based test selection". In Testing of Communicating Systems, 200–219. Boston, MA: Springer US, 1997. http://dx.doi.org/10.1007/978-0-387-35198-8_13.
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Liu, Haoliang, Tan Yu e Ping Li. "Sensitivity-aware Distance Measurement for Boosting Metric Learning". In Proceedings of the 2022 SIAM International Conference on Data Mining (SDM), 576–84. Philadelphia, PA: Society for Industrial and Applied Mathematics, 2022. http://dx.doi.org/10.1137/1.9781611977172.65.
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Evans, Jeffrey J., e Cynthia S. Hood. "A Network Performance Sensitivity Metric for Parallel Applications". In Parallel and Distributed Processing and Applications, 920–31. Berlin, Heidelberg: Springer Berlin Heidelberg, 2007. http://dx.doi.org/10.1007/978-3-540-74742-0_81.
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Liu, Wendi, Léan E. Garland, Jesus Ochoa e Michael J. Pyrcz. "A Geostatistical Heterogeneity Metric for Spatial Feature Engineering". In Springer Proceedings in Earth and Environmental Sciences, 3–19. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-19845-8_1.
Abstract (sommario):
AbstractHeterogeneity is a vital spatial feature for subsurface resource recovery predictions, such as mining grade tonnage functions, hydrocarbon recovery factor, and water aquifer draw-down predictions. Feature engineering presents the opportunity to integrate heterogeneity information, but traditional heterogeneity engineered features like Dykstra-Parsons and Lorenz coefficients ignore the spatial context; therefore, are not sufficient to quantify the heterogeneity over multiple scales of spatial intervals to inform predictive machine learning models. We propose a novel use of dispersion variance as a spatial-engineered feature that accounts for heterogeneity within the spatial context, including spatial continuity and sample data and model volume support size to improve predictive machine-learning-based models, e.g., for pre-drill prediction and uncertainty quantification. Dispersion variance is a generalized form of variance that accounts for volume support size and can be calculated from the semivariogram-based spatial continuity model. We demonstrate dispersion variance as a useful predictor feature for the case of hydrocarbon recovery prediction, with the ability to quantify the spatial variation over the support size of the production well drainage radius, given the spatial continuity from the variogram and trajectory of the well. We include a synthetic example based on geostatistical models and flow simulation to show the sensitivity of dispersion variance to production. Then we demonstrate the dispersion variance as an informative predictor feature for production forecasting with a field case study in the Duvernay formation.
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Muhamed, Aashiq, Sriram Srinivasan, Choon-Hui Teo, Qingjun Cui, Belinda Zeng, Trishul Chilimbi e S. V. N. Vishwanathan. "Web-Scale Semantic Product Search with Large Language Models". In Advances in Knowledge Discovery and Data Mining, 73–85. Cham: Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-33380-4_6.
Abstract (sommario):
AbstractDense embedding-based semantic matching is widely used in e-commerce product search to address the shortcomings of lexical matching such as sensitivity to spelling variants. The recent advances in BERT-like language model encoders, have however, not found their way to realtime search due to the strict inference latency requirement imposed on e-commerce websites. While bi-encoder BERT architectures enable fast approximate nearest neighbor search, training them effectively on query-product data remains a challenge due to training instabilities and the persistent generalization gap with cross-encoders. In this work, we propose a four-stage training procedure to leverage large BERT-like models for product search while preserving low inference latency. We introduce query-product interaction pre-finetuning to effectively pretrain BERT bi-encoders for matching and improve generalization. Through offline experiments on an e-commerce product dataset, we show that a distilled small BERT-based model (75M params) trained using our approach improves the search relevance metric by up to 23% over a baseline DSSM-based model with similar inference latency. The small model only suffers a 3% drop in relevance metric compared to the 20x larger teacher. We also show using online A/B tests at scale, that our approach improves over the production model in exact and substitute products retrieved.
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wunder, june, Arthur Azevedo de Amorim, Patrick Baillot e Marco Gaboardi. "Bunched Fuzz: Sensitivity for Vector Metrics". In Programming Languages and Systems, 451–78. Cham: Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-30044-8_17.
Abstract (sommario):
AbstractProgram sensitivity measures the distance between the outputs of a program when run on two related inputs. This notion, which plays a key role in areas such as data privacy and optimization, has been the focus of several program analysis techniques introduced in recent years. Among the most successful ones, we can highlight type systems inspired by linear logic, as pioneered by Reed and Pierce in the Fuzz programming language. In Fuzz, each type is equipped with its own distance, and sensitivity analysis boils down to type checking. In particular, Fuzz features two product types, corresponding to two different notions of distance: the tensor product combines the distances of each component by adding them, while the with product takes their maximum.In this work, we show that these products can be generalized to arbitrary $$L^p$$ L p distances, metrics that are often used in privacy and optimization. The original Fuzz products, tensor and with, correspond to the special cases $$L^1$$ L 1 and $$L^\infty $$ L ∞ . To ease the handling of such products, we extend the Fuzz type system with bunches—as in the logic of bunched implications—where the distances of different groups of variables can be combined using different $$L^p$$ L p distances. We show that our extension can be used to reason about quantitative properties of probabilistic programs.
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Leugering, Günter. "Partial Differential Equations on Metric Graphs: A Survey of Results on Optimization, Control, and Stabilizability Problems with Special Focus on Shape and Topological Sensitivity Problems". In Mathematical Modelling, Optimization, Analytic and Numerical Solutions, 77–115. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-0928-5_4.
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Zakrzewska, Anita, e David A. Bader. "Measuring the Sensitivity of Graph Metrics to Missing Data". In Parallel Processing and Applied Mathematics, 783–92. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-642-55224-3_73.
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Hrga, Ingrid, e Marina Ivasic-Kos. "Measuring the Sensitivity of Image Captioning Metrics to Caption Perturbations". In Proceedings of Eighth International Congress on Information and Communication Technology, 1053–63. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-3236-8_85.
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Zyla, Joanna, Michal Marczyk e Joanna Polanska. "Sensitivity, Specificity and Prioritization of Gene Set Analysis When Applying Different Ranking Metrics". In Advances in Intelligent Systems and Computing, 61–69. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-40126-3_7.
Atti di convegni sul tema "Sensitivity metric":
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Tan, J. "IMPACT OF SAMPLING RATE ON FLICKER METRIC CALCULATIONS". In CIE Symposium on Advances on the Measurement of Temporal Light Modulation. International Commission on Illumination (CIE), 2022. http://dx.doi.org/10.25039/x49.2022.p13.
Abstract (sommario):
In order to estimate the visibility of temporal light modulation (TLM), also known as "flicker", various metrics are employed in research and commerce. The metrics, however, are not easily calculated, and occasionally the values change depending on sampling rates. This study investigates the complexities involved in processing data from TLM waveform metrics and then calculating metrics. It explores the sensitivity of each metric to sampling rate, and recommendations are then provided for how to increase the accuracy and consistency of the metrics by using appropriate sampling rates. The analyses in this study are based on noise-free and stable ideal waveforms; however, sampling rate effects also exist for real-world waveforms.
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Daroya, Rangel, Aaron Sun e Subhransu Maji. "COSE: A Consistency-Sensitivity Metric for Saliency on Image Classification". In 2023 IEEE/CVF International Conference on Computer Vision Workshops (ICCVW). IEEE, 2023. http://dx.doi.org/10.1109/iccvw60793.2023.00022.
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Ahmed, Faez, Sharath Kumar Ramachandran, Mark Fuge, Sam Hunter e Scarlett Miller. "Measuring and Optimizing Design Variety Using Herfindahl Index". In ASME 2019 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/detc2019-97778.
Abstract (sommario):
Abstract In this paper, we propose a new design variety metric based on the Herfindahl index. We also propose a practical procedure for comparing variety metrics via the construction of ground truth datasets from pairwise comparisons by experts. Using two new datasets, we show that this new variety measure aligns with human ratings more than some existing and commonly used tree-based metrics. This metric also has three main advantages over existing metrics: a) It is a super-modular function, which enables us to optimize design variety using a polynomial time greedy algorithm. b) The parametric nature of this metric allows us to fit the metric to better represent variety for new domains. c) It has higher sensitivity in distinguishing between variety of sets of randomly selected designs than existing methods. Overall, our results shed light on some qualities that good design variety metrics should possess and the non-trivial challenges associated with collecting the data needed to measure those qualities.
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Chadha, Shyam, Daniel Hung e Samir Rashid. "A Novel Approach to Evaluating Leak Detection CPM System Sensitivity/Reliability Performance Trade-Offs". In 2014 10th International Pipeline Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/ipc2014-33650.
Abstract (sommario):
As defined in American Petroleum Institute Recommended Practice 1130 (API RP 1130), CPM system leak detection performance is evaluated on the basis of four distinct but interrelated metrics: sensitivity, reliability, accuracy and robustness. These performance metrics are captured to evaluate performance, manage risk and prioritize mitigation efforts. Evaluating and quantifying sensitivity performance of a CPM system is paramount to ensure the performance of the CPM system is acceptable based on a company’s risk profile for detecting leaks. Employing API RP 1130 recommended testing methodologies including parameter manipulation techniques, software simulated leak tests and/or removal of test quantities of commodity from the pipeline are excellent approaches to understanding the leak sensitivity metric. Good reliability (false alarm) performance is critical to ensure that control center operator desensitization does not occur through long term exposure to false alarms. Continuous tracking and analyzing of root causes of leak alarms ensures that the effects of seasonal variations or changes to operation on CPM system performance are managed appropriately. The complexity of quantifying this metric includes qualitatively evaluating the relevance of false alarms. The interrelated nature of the above performance metrics imposes conflicting requirements and results in inherent trade-offs. Optimizing the trade-off between reliability and sensitivity involves identifying the point that thresholds must be set to obtain a balance of a desired sensitivity and false alarm rate. This paper presents an approach to illustrate the combined sensitivity/reliability performance for an example pipeline. The paper discusses considerations addressed while determining the methodology such as stakeholder input, ongoing CPM system enhancements, sensitivity/reliability trade-off, risk based capital investment and graphing techniques. The paper also elaborates on a number of identified benefits of the selected overall methodology.
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Dasarathy, Belur V. "Metric sensitivity of reciprocal relationship bonds in the knowledge discovery process". In AeroSense 2000, a cura di Belur V. Dasarathy. SPIE, 2000. http://dx.doi.org/10.1117/12.381719.
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Dasarathy, Belur V. "Metric sensitivity of the multisensor information fusion process under instance-based learning". In Aerospace/Defense Sensing, Simulation, and Controls, a cura di Belur V. Dasarathy. SPIE, 2001. http://dx.doi.org/10.1117/12.421094.
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Lee, Donghyun, Minkyoung Cho, Seungwon Lee, Joonho Song e Changkyu Choi. "A Novel Sensitivity Metric For Mixed-Precision Quantization With Synthetic Data Generation". In 2021 IEEE International Conference on Image Processing (ICIP). IEEE, 2021. http://dx.doi.org/10.1109/icip42928.2021.9506527.
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Brusilowicz, B., Michalik Michalik, W. Rebizant e L. Schiel. "Sensitivity Comparison of Admittance and Watt-metric Criteria for Ground Fault Detection". In 13th International Conference on Development in Power System Protection 2016 (DPSP). Institution of Engineering and Technology, 2016. http://dx.doi.org/10.1049/cp.2016.0033.
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Susu Yao, EePing Ong e Mei Hwan Loke. "Peceptual distortion metric based on wavelet frequency sensitivity and multiple visual fixations". In 2008 IEEE International Symposium on Circuits and Systems - ISCAS 2008. IEEE, 2008. http://dx.doi.org/10.1109/iscas.2008.4541441.
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Roy, Sujan Kumar, e Kuldip K. Paliwal. "Sensitivity Metric-Based Tuning of the Augmented Kalman Filter for Speech Enhancement". In 2020 14th International Conference on Signal Processing and Communication Systems (ICSPCS). IEEE, 2020. http://dx.doi.org/10.1109/icspcs50536.2020.9310005.
Rapporti di organizzazioni sul tema "Sensitivity metric":
1
Hossain, Niamat Ullah Ibne, Farjana Nur, Raed Jaradat, Seyedmohsen Hosseini, Mohammad Marufuzzaman, Stephen Puryear e Randy Buchanan. Metrics for assessing overall performance of inland waterway ports : a Bayesian Network based approach. Engineer Research and Development Center (U.S.), maggio 2021. http://dx.doi.org/10.21079/11681/40545.
Abstract (sommario):
Because ports are considered to be the heart of the maritime transportation system, thereby assessing port performance is necessary for a nation’s development and economic success. This study proposes a novel metric, namely, “port performance index (PPI)”, to determine the overall performance and utilization of inland waterway ports based on six criteria, port facility, port availability, port economics, port service, port connectivity, and port environment. Unlike existing literature, which mainly ranks ports based on quantitative factors, this study utilizes a Bayesian Network (BN) model that focuses on both quantitative and qualitative factors to rank a port. The assessment of inland waterway port performance is further analyzed based on different advanced techniques such as sensitivity analysis and belief propagation. Insights drawn from the study show that all the six criteria are necessary to predict PPI. The study also showed that port service has the highest impact while port economics has the lowest impact among the six criteria on PPI for inland waterway ports.
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Hamada, Michael S., Rene Lynn Bierbaum e Alix A. Robertson. Surveillance metrics sensitivity study. Office of Scientific and Technical Information (OSTI), settembre 2011. http://dx.doi.org/10.2172/1030396.
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Bierbaum, R., M. Hamada e A. Robertson. Surveillance Metrics Sensitivity Study. Office of Scientific and Technical Information (OSTI), novembre 2011. http://dx.doi.org/10.2172/1035302.
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Job, Jacob. Mesa Verde National Park: Acoustic monitoring report. National Park Service, luglio 2021. http://dx.doi.org/10.36967/nrr-2286703.
Abstract (sommario):
In 2015, the Natural Sounds and Night Skies Division (NSNSD) received a request to collect baseline acoustical data at Mesa Verde National Park (MEVE). Between July and August 2015, as well as February and March 2016, three acoustical monitoring systems were deployed throughout the park, however one site (MEVE002) stopped recording after a couple days during the summer due to wildlife interference. The goal of the study was to establish a baseline soundscape inventory of backcountry and frontcountry sites within the park. This inventory will be used to establish indicators and thresholds of soundscape quality that will support the park and NSNSD in developing a comprehensive approach to protecting the acoustic environment through soundscape management planning. Additionally, results of this study will help the park identify major sources of noise within the park, as well as provide a baseline understanding of the acoustical environment as a whole for use in potential future comparative studies. In this deployment, sound pressure level (SPL) was measured continuously every second by a calibrated sound level meter. Other equipment included an anemometer to collect wind speed and a digital audio recorder collecting continuous recordings to document sound sources. In this document, “sound pressure level” refers to broadband (12.5 Hz–20 kHz), A-weighted, 1-second time averaged sound level (LAeq, 1s), and hereafter referred to as “sound level.” Sound levels are measured on a logarithmic scale relative to the reference sound pressure for atmospheric sources, 20 μPa. The logarithmic scale is a useful way to express the wide range of sound pressures perceived by the human ear. Sound levels are reported in decibels (dB). A-weighting is applied to sound levels in order to account for the response of the human ear (Harris, 1998). To approximate human hearing sensitivity, A-weighting discounts sounds below 1 kHz and above 6 kHz. Trained technicians calculated time audible metrics after monitoring was complete. See Methods section for protocol details, equipment specifications, and metric calculations. Median existing (LA50) and natural ambient (LAnat) metrics are also reported for daytime (7:00–19:00) and nighttime (19:00–7:00). Prominent noise sources at the two backcountry sites (MEVE001 and MEVE002) included vehicles and aircraft, while building and vehicle predominated at the frontcountry site (MEVE003). Table 1 displays time audible values for each of these noise sources during the monitoring period, as well as ambient sound levels. In determining the current conditions of an acoustical environment, it is informative to examine how often sound levels exceed certain values. Table 2 reports the percent of time that measured levels at the three monitoring locations were above four key values.
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Christy, John, Roy Spencer e Richard McNider. Toward an improved estimate of climate sensitivity and its application to key climate metrics. Office of Scientific and Technical Information (OSTI), aprile 2023. http://dx.doi.org/10.2172/1973134.
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Christy, John, Roy Spencer e Richard McNider. Final Report: Toward an improved estimate of climate sensitivity and its application to key climate metrics. Office of Scientific and Technical Information (OSTI), marzo 2023. http://dx.doi.org/10.2172/1968277.
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Johra, Hicham. Simple uncertainty budget and assessment with the Kragten method: Examples for building physics. Department of the Built Environment, 2024. http://dx.doi.org/10.54337/aau633631860.
Abstract (sommario):
The aim of this lecture note is to present and exemplify the Kragten method to calculate the combined uncertainty (uncertainty budget) of a measurand from the standard uncertainty estimates of individual inputs of that measurand, and the mathematical formulation of that measurand. If these two elements are not available, the Kragten method cannot be applied. The method also provides sensitivity (significance) assessment of the different components (inputs) in the combined uncertainty budget. The Kragten method for uncertainty calculation is very simple yet a robust and accurate alternative to the more complex GUM or Monte Carlo simulation methods. It can be performed with a simple spreadsheet tool (e.g., MS Excel) with minimum risks of mistakes. This method is adequate for the field of building physics, energy in buildings and indoor environmental engineering. This lecture note also provides examples of uncertainty calculations (budgets) for common measurands and metrics in the field of building physics, energy in buildings and indoor environmental engineering. These examples are attached to the present lecture note document (Excel spreadsheet documents). One should note that this lecture note does not cover the process of estimating the standard uncertainty of the individual inputs of the measurand. Those standard uncertainties should be obtained from technical documentation, models, or estimates from measurements (e.g., 1σ standard deviation of a set of repeated measurements on measurand that is assumed to remain constant over the monitoring period), and converted into standard uncertainties (1σ confidence interval assuming a normal probability distribution or the errors).
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Thoma, David. Landscape phenology, vegetation condition, and relations with climate at Canyonlands National Park, 2000–2019. A cura di Alice Wondrak Biel. National Park Service, giugno 2023. http://dx.doi.org/10.36967/2299619.
Abstract (sommario):
Quantitatively linking satellite observations of vegetation condition and climate data over time provides insight to climate influences on primary production, phenology (timing of growth), and sensitivity of vegetation to weather and longer-term patterns of weather referred to as climate. This in turn provides a basis for understanding potential climate impacts to vegetation—and the potential to anticipate cascading ecological effects—such as impacts to forage, habitat, fire potential, and erosion—as climate changes in the future. This report provides baseline information about vegetation production and condition over time at Canyonlands National Park (NP), as derived from satellite remote sensing. Its objective is to demonstrate methods of analysis, share findings, and document historic climate exposure and sensitivity of vegetation to weather and climate as a driver of vegetation change. This report represents a quantitative foundation of vegetation–climate relationships on an annual timestep. The methods can be modified to finer temporal resolution and other spatial scales if further analyses are needed to inform park planning and management. The knowledge provided in this report can inform vulnerability assessments for Climate Smart Conservation planning by park managers. Patterns of pivot points and responses can serve as a guide to anticipate what, where, when, and why vegetation change may occur. For this analysis, vegetation alliance groups were derived from vegetation-map polygons (Von Loh et al. 2007) by lumping vegetation types expected to respond similarly to climate. Relationships between vegetation production and phenology were evaluated for each alliance map unit larger than a satellite pixel (~300 × 300 m). We used a water-balance model to characterize the climate experienced by plants. Water balance translates temperature and precipitation into more biophysically relevant climate metrics, such as soil moisture and drought stress, that are often more strongly correlated with vegetation condition than temperature or precipitation are. By accounting for the interactions between temperature, precipitation, and site characteristics, water balance helps make regional climate assessments relevant to local scales. The results provide a foundation for interpreting weather and climate as a driver of changes in primary production over a 20-year period at the polygon and alliance-group scale. Additionally, they demonstrate how vegetation type and site characteristics, such as soil properties, slope, and aspect, interact with climate at local scales to determine trends in vegetation condition. This report quantitatively defines critical water needs of vegetation and identifies which alliance types, in which locations, may be most susceptible to climate-change impacts in the future. Finally, this report explains how findings can be used in the Climate Smart Conservation framework, with scenario planning, to help manage park resources through transitions imposed by climate change.
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Thoma, David. Landscape phenology, vegetation condition, and relations with climate at Capitol Reef National Park, 2000–2019. A cura di Alice Wondrak Biel. National Park Service, marzo 2023. http://dx.doi.org/10.36967/2297289.
Abstract (sommario):
Quantitatively linking satellite observations of vegetation condition and climate data over time provides insight to climate influences on primary production, phenology (timing of growth), and sensitivity of vegetation to weather and longer-term patterns of weather referred to as climate. This in turn provides a basis for understanding potential climate impacts to vegetation—and the potential to anticipate cascading ecological effects, such as impacts to forage, habitat, fire potential, and erosion, as climate changes in the future. This report provides baseline information about vegetation production and condition over time at Capitol Reef National Park (NP), as derived from satellite remote sensing. Its objective is to demonstrate methods of analysis, share findings, and document historic climate exposure and sensitivity of vegetation to weather and climate as a driver of vegetation change. This report represents a quantitative foundation of vegetation–climate relationships on an annual timestep. The methods can be modified to finer temporal resolution and other spatial scales if further analyses are needed to inform park planning and management. The knowledge provided in this report can inform vulnerability assessments for Climate Smart Conservation planning by park managers. Patterns of pivot points and responses can serve as a guide to anticipate what, where, when, and why vegetation change may occur. For this analysis, vegetation alliance groups were derived from vegetation-map polygons (Von Loh et al. 2007) by lumping vegetation types expected to respond similarly to climate. Relationships between vegetation production and phenology were evaluated for each alliance map unit larger than a satellite pixel (~300 × 300 m). We used a water-balance model to characterize the climate experienced by plants. Water balance translates temperature and precipitation into more biophysically relevant climate metrics, such as soil moisture and drought stress, that are often more strongly correlated with vegetation condition than temperature or precipitation are. By accounting for the interactions between temperature, precipitation, and site characteristics, water balance helps make regional climate assessments relevant to local scales. The results provide a foundation for interpreting weather and climate as a driver of changes in primary production over a 20-year period at the polygon and alliance-group scale. Additionally, they demonstrate how vegetation type and site characteristics, such as soil properties, slope, and aspect, interact with climate at local scales to determine trends in vegetation condition. This report quantitatively defines critical water needs of vegetation and identifies which alliance types, in which locations, may be most susceptible to climate-change impacts in the future. Finally, this report explains how findings can be used in the Climate Smart Conservation framework, with scenario planning, to help manage park resources through transitions imposed by climate change.
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Mazzoni, Silvia, Nicholas Gregor, Linda Al Atik, Yousef Bozorgnia, David Welch e Gregory Deierlein. Probabilistic Seismic Hazard Analysis and Selecting and Scaling of Ground-Motion Records (PEER-CEA Project). Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA, novembre 2020. http://dx.doi.org/10.55461/zjdn7385.
Abstract (sommario):
This report is one of a series of reports documenting the methods and findings of a multi-year, multi-disciplinary project coordinated by the Pacific Earthquake Engineering Research Center (PEER) and funded by the California Earthquake Authority (CEA). The overall project is titled “Quantifying the Performance of Retrofit of Cripple Walls and Sill Anchorage in Single-Family Wood-Frame Buildings,” henceforth referred to as the “PEER–CEA Project.” The overall objective of the PEER–CEA Project is to provide scientifically based information (e.g., testing, analysis, and resulting loss models) that measure and assess the effectiveness of seismic retrofit to reduce the risk of damage and associated losses (repair costs) of wood-frame houses with cripple wall and sill anchorage deficiencies as well as retrofitted conditions that address those deficiencies. Tasks that support and inform the loss-modeling effort are: (1) collecting and summarizing existing information and results of previous research on the performance of wood-frame houses; (2) identifying construction features to characterize alternative variants of wood-frame houses; (3) characterizing earthquake hazard and ground motions at representative sites in California; (4) developing cyclic loading protocols and conducting laboratory tests of cripple wall panels, wood-frame wall subassemblies, and sill anchorages to measure and document their response (strength and stiffness) under cyclic loading; and (5) the computer modeling, simulations, and the development of loss models as informed by a workshop with claims adjustors. This report is a product of Working Group 3 (WG3), Task 3.1: Selecting and Scaling Ground-motion records. The objective of Task 3.1 is to provide suites of ground motions to be used by other working groups (WGs), especially Working Group 5: Analytical Modeling (WG5) for Simulation Studies. The ground motions used in the numerical simulations are intended to represent seismic hazard at the building site. The seismic hazard is dependent on the location of the site relative to seismic sources, the characteristics of the seismic sources in the region and the local soil conditions at the site. To achieve a proper representation of hazard across the State of California, ten sites were selected, and a site-specific probabilistic seismic hazard analysis (PSHA) was performed at each of these sites for both a soft soil (Vs30 = 270 m/sec) and a stiff soil (Vs30=760 m/sec). The PSHA used the UCERF3 seismic source model, which represents the latest seismic source model adopted by the USGS [2013] and NGA-West2 ground-motion models. The PSHA was carried out for structural periods ranging from 0.01 to 10 sec. At each site and soil class, the results from the PSHA—hazard curves, hazard deaggregation, and uniform-hazard spectra (UHS)—were extracted for a series of ten return periods, prescribed by WG5 and WG6, ranging from 15.5–2500 years. For each case (site, soil class, and return period), the UHS was used as the target spectrum for selection and modification of a suite of ground motions. Additionally, another set of target spectra based on “Conditional Spectra” (CS), which are more realistic than UHS, was developed [Baker and Lee 2018]. The Conditional Spectra are defined by the median (Conditional Mean Spectrum) and a period-dependent variance. A suite of at least 40 record pairs (horizontal) were selected and modified for each return period and target-spectrum type. Thus, for each ground-motion suite, 40 or more record pairs were selected using the deaggregation of the hazard, resulting in more than 200 record pairs per target-spectrum type at each site. The suites contained more than 40 records in case some were rejected by the modelers due to secondary characteristics; however, none were rejected, and the complete set was used. For the case of UHS as the target spectrum, the selected motions were modified (scaled) such that the average of the median spectrum (RotD50) [Boore 2010] of the ground-motion pairs follow the target spectrum closely within the period range of interest to the analysts. In communications with WG5 researchers, for ground-motion (time histories, or time series) selection and modification, a period range between 0.01–2.0 sec was selected for this specific application for the project. The duration metrics and pulse characteristics of the records were also used in the final selection of ground motions. The damping ratio for the PSHA and ground-motion target spectra was set to 5%, which is standard practice in engineering applications. For the cases where the CS was used as the target spectrum, the ground-motion suites were selected and scaled using a modified version of the conditional spectrum ground-motion selection tool (CS-GMS tool) developed by Baker and Lee [2018]. This tool selects and scales a suite of ground motions to meet both the median and the user-defined variability. This variability is defined by the relationship developed by Baker and Jayaram [2008]. The computation of CS requires a structural period for the conditional model. In collaboration with WG5 researchers, a conditioning period of 0.25 sec was selected as a representative of the fundamental mode of vibration of the buildings of interest in this study. Working Group 5 carried out a sensitivity analysis of using other conditioning periods, and the results and discussion of selection of conditioning period are reported in Section 4 of the WG5 PEER report entitled Technical Background Report for Structural Analysis and Performance Assessment. The WG3.1 report presents a summary of the selected sites, the seismic-source characterization model, and the ground-motion characterization model used in the PSHA, followed by selection and modification of suites of ground motions. The Record Sequence Number (RSN) and the associated scale factors are tabulated in the Appendices of this report, and the actual time-series files can be downloaded from the PEER Ground-motion database Portal (https://ngawest2.berkeley.edu/)(link is external).