empirical relationships were developed to estimate potential landslide runout length and deposit area for slopes in the eastern Salish (Puget) Lowland in northwestern Washington. Published empirical equations use land...
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empirical relationships were developed to estimate potential landslide runout length and deposit area for slopes in the eastern Salish (Puget) Lowland in northwestern Washington. Published empirical equations use landslide parameters of runout length (L), height (H), reach angle (a), deposit area (A), and volume (V) and linear or log-based regressions. Most data sets include varying landslide types and sizes, geology, and geographic locations, and many are for long-runout debris flows, lahars, and rock avalanches. The Salish Lowland is well suited for a regional study because of the available high-quality topographic data, slopes with relatively consistent topography and geology, and numerous landslides. The total data set includes 223 landslides mapped in the Cedar River (N = 141), North Fork Stillaguamish River (N = 17), and Skagit River-Finney Creek (N = 65) valleys. The data include H and L for debris slides (N = 162), debris flows (N = 39), and flow slides and debris avalanches (N = 22), and V and A data for the Cedar River landslides. Log-log regressions for the total data and landslide type subsets have good correlations for L as a function of H (R-2 = 0.71 to 0.77) and A as a function of V (R-2 = 0.76 to 0.95). However, relationships using a or tan a have very poor correlations. This methodology can be used to assess probabilities of L and A for landslide runout risk assessment of slopes in the Salish Lowland primarily underlain by late Pleistocene glacial and interglacial deposits.
BackgroundOver the past several decades, metrics have been defined to assess the quality of various types of models and to compare their performance depending on their capacity to explain the variance found in real-li...
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BackgroundOver the past several decades, metrics have been defined to assess the quality of various types of models and to compare their performance depending on their capacity to explain the variance found in real-life data. However, available validation methods are mostly designed for statistical regressions rather than for mechanistic models. To our knowledge, in the latter case, there are no consensus standards, for instance for the validation of predictions against real-world data given the variability and uncertainty of the data. In this work, we focus on the prediction of time-to-event curves using as an application example a mechanistic model of non-small cell lung cancer. We designed four empirical methods to assess both model performance and reliability of predictions: two methods based on bootstrapped versions of parametric statistical tests: log-rank and combined weighted log-ranks (MaxCombo);and two methods based on bootstrapped prediction intervals, referred to here as raw coverage and the juncture metric. We also introduced the notion of observation time uncertainty to take into consideration the real life delay between the moment when an event happens, and the moment when it is observed and *** highlight the advantages and disadvantages of these methods according to their application context. We have shown that the context of use of the model has an impact on the model validation process. Thanks to the use of several validation metrics we have highlighted the limit of the model to predict the evolution of the disease in the whole population of mutations at the same time, and that it was more efficient with specific predictions in the target mutation populations. The choice and use of a single metric could have led to an erroneous validation of the model and its context of *** this work, we stress the importance of making judicious choices for a metric, and how using a combination of metrics could be more relevant, with
In this study, new empirical predictive relationships for earthquake-induced crest settlement of earth-core rockfill dams (ECRDs) were developed. A case history database of 19 dams that had been subjected to earthquak...
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In this study, new empirical predictive relationships for earthquake-induced crest settlement of earth-core rockfill dams (ECRDs) were developed. A case history database of 19 dams that had been subjected to earthquakes was utilized. The presented relationships correlate the intensity measure (IM) of the earthquake records with the observed settlements, and thus, employing IMs that appropriately describe the severity of ground motion is of vital importance. It is well known that the dynamic properties of an ECRD can change significantly depending on the severity of an earthquake, and that this phenomenon can substantially impact the dynamic responses of dams. Accordingly, two IMs were suggested, taking into account the essential characteristics of ground motions affecting the nonlinear behaviour of ECRDs. The results indicate that the proposed relationships effectively address the limitations of the existing ones, and that they are practical tools that efficiently predict the seismic settlements of ECRDs.
Machine learning (ML) models based on artificial neural network (ANN) and decision tree (DT) were developed for estimation of axial capacity of concrete columns reinforced with fiber reinforced polymer (FRP) bars. Bet...
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Machine learning (ML) models based on artificial neural network (ANN) and decision tree (DT) were developed for estimation of axial capacity of concrete columns reinforced with fiber reinforced polymer (FRP) bars. Between the design codes, the Canadian code provides better formulation compared to the Australian or American code. For empirical models based on elastic modulus of FRP, Hadhood et al. (2017) model performed best. Whereas for empirical models based on tensile strength of FRP, as well as all empirical models, Raza et al. (2021) was adjudged superior. However, compared to the empirical models, all ML models exhibited superior performance according to all five performance metrics considered. The performance of ANN and DT models were comparable in general. Under the present setup, inclusion of the transverse reinforcement information did not improve the accuracy of estimation with either ANN or DT. With selective use of inputs, and a much simpler ANN architecture (4-3-1) compared to that reported in literature (Raza et al. 2020: 6-11-11-1), marginal improvement in correlation could be achieved. The metrics for the best model from the study was a correlation of 0.94, absolute errors between 420 kN to 530 kN, and the range being 0.39 to 0.51 for relative errors. Though much superior performance could be obtained using ANN/DT models over empirical models, further work towards improving accuracy of the estimation is indicated before design of FRP reinforced concrete columns using ML may be considered for design codes.
PurposeContinuous improvement in an integrated approach is a philosophy developed over decades based on a set of management practices. It comprises enhancement methodologies that escalate success as well as diminishes...
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PurposeContinuous improvement in an integrated approach is a philosophy developed over decades based on a set of management practices. It comprises enhancement methodologies that escalate success as well as diminishes letdowns. The state-of-the-art literature finds a variety of practices for the execution of continuous improvement (CI) system. However, it is rare to find an empirical study with an inclusive system that considers various practices in one frame for improving competitiveness. With this outlook, therefore, this study aims originally to identify drivers, motivations and barriers for the application of integrated CI system, and then conduct an empirical investigation within the context of Ethiopian manufacturing ***/methodology/approachJustification of the problem, extensive review of literature, identification of practices, developing research framework, investigational analysis of the empirical study using reliability and descriptive statistical analysis and identifying leading drivers (unique practices and common factors), motivations and barriers are the research approaches used in this study. Furthermore, the primary data were collected through a self-administered questionnaire and were analyzed using a statistical package for social science (SPSS) 23 and the findings were triangulated to relate to the existing state-of-the-art *** findings indicate 17 common factors associated with human, strategic, operational, technology, structure, resource and information factors;21 unique practices of just-in-time (JIT), lean-six sigma (LSS), supply chain management (SCM), total productive maintenance (TPM), and total quality management (TQM) methodologies;20 barriers connected with internal and external issues and 17 motivations linked to operational, innovation and business results are identified. In general, the empirical analysis discovers the practices are noteworthy and commonly supported by a least of 52% of the responden
Superconductivity is a phenomenon arising from cooperative electron ***,correlations among(1)the minimum tuning parameter required for emergence,(2)the superconducting transition temperature resulting from minimal tun...
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Superconductivity is a phenomenon arising from cooperative electron ***,correlations among(1)the minimum tuning parameter required for emergence,(2)the superconducting transition temperature resulting from minimal tuning,and(3)the host’s physical/chemical properties still elude the scientific *** empirical investigations,such as those revealing ideal gas-like correlations at the onset of superconductivity in intercalated superconductors,motivate this *** investigation reports similar findings in systems(>170 compounds)exhibiting superconductivity through other perturbative means,such as single-element *** general,statistical measures,including distance correlation analyses(≠linear regression fit)of thermodynamic variables,indicate the presence of empirical relationships near the superconducting onset of systematically tuned *** relations involve unit cell volume(V),the number of valence electrons(N),and the superconducting transition temperature(T_(c)).Note:The author’s primary aim is not to validate or challenge BCS theory;it is instead to focus on leveraging methodology led by available data to enhance the exploration and development of innovative and cost-effective superconductors.
Aim: To retrospectively evaluate clinical and microbiological outcomes after combined surgical and medical therapy for diabetic foot infections (DFIs), stratifying between the empirical versus the targeted nature, and...
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Aim: To retrospectively evaluate clinical and microbiological outcomes after combined surgical and medical therapy for diabetic foot infections (DFIs), stratifying between the empirical versus the targeted nature, and between an empirical broad versus a narrow-spectrum, antibiotic therapy. Methods: We retrospectively assessed the rate of ultimate therapeutic failures for each of three types of initial postoperative antibiotic therapy: adequate empirical therapy;culture-guided therapy;and empirical inadequate therapy with a switch to targeted treatment based on available microbiological results. Results: We included data from 332 patients who underwent 716 DFI episodes of surgical debridement, including partial amputations. Clinical failure occurred in 40 of 194 (20.6%) episodes where adequate empirical therapy was given, in 77 of 291 (26.5%) episodes using culture-guided (and correct) therapy from the start, and in 73 of 231 (31.6%) episodes with switching from empirical inadequate therapy to culture-targeted therapy. Equally, a broad-spectrum antibiotic choice could not alter this failure risk. Group comparisons, Kaplan-Meier curves and Cox regression analyses failed to show either statistical superiority or inferiority of any of the initial antibiotic strategies. Conclusions: In this study, the microbiological adequacy of the initial antibiotic regimen after (surgical) debridement for DFI did not alter therapeutic outcomes. We recommend that clinicians follow the stewardship approach of avoiding antibiotic de-escalation and start with a narrow-spectrum regimen based on the local epidemiology.
BackgroundThe empirical trial aims to assess safety and efficacy of an empirical treatment against cytomegalovirus (CMV) and tuberculosis (TB) compared to standard of care (SoC), on adverse events and 15-day and 1-yea...
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BackgroundThe empirical trial aims to assess safety and efficacy of an empirical treatment against cytomegalovirus (CMV) and tuberculosis (TB) compared to standard of care (SoC), on adverse events and 15-day and 1-year mortality among infants living with HIV hospitalized with severe pneumonia in *** and designThe empirical trial (NCT03915366) is an international multicenter phase II-III, open-label randomized factorial clinical trial conducted in six African countries. The trial has four randomization arms in a 1:1:1:1 fashion with patients allocated to (i) TB-Treatment plus SoC, (ii) valganciclovir plus SoC, (iii) both TB-Treatment and valganciclovir plus SoC, and (iv) SoC *** paper describes the statistical analysis plan (SAP) for the trial which, per the study publication plan, needs to be published prior to the database lock and final analysis results. The SAP includes details of the analyses to be undertaken and unpopulated tables that will be reported to address primary and secondary endpoints. The database will be locked on 31st January *** ***: NCT03915366 (registered on April 16, 2019), Universal Trial Number: U111-1231-4736, Pan African Clinical Trial Registry: PACTR201994797961340.
Based on the statistics of private investment data in Xi'an from 2010 to 2021, this article uses the DEA Malmquist model to empirically analyze the efficiency of private investment in Xi'an. The study found th...
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Plain language summaryAs resistance to antibiotics is increasing among microbes, rational use of these drugs is important both in the community and in hospitals. Many infections with resistant microorganisms may be fa...
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Plain language summaryAs resistance to antibiotics is increasing among microbes, rational use of these drugs is important both in the community and in hospitals. Many infections with resistant microorganisms may be fatal. For a long time, carbapenems have been the last resort for treatment of resistant microorganisms. Unfortunately, resistance to these drugs is increasing. It appears that use of higher doses of antibiotics may help in some cases. However, the potential harm caused by higher doses is a problem. In this primary study, higher doses of meropenem, a common carbapenem, were found to be safe. Objective: To evaluate the safety of megadose meropenem as empirical treatment of nosocomial sepsis. Materials & methods: Critically ill patients diagnosed with sepsis received either high-dose (2 g every 8 h) or megadose (4 g every 8 h) meropenem as an intravenous infusion over 3 h. Results: A total of 23 patients with nosocomial sepsis were eligible and included in the megadose (n = 11) or high-dose (n = 12) group. No treatment-related adverse events were observed during a 14-day follow-up. Clinical response was also comparable between the groups. Conclusion: Megadose meropenem may be considered for empirical treatment of nosocomial sepsis without serious concern regarding its safety.
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