scholarly journals Sensitivity Analysis of Kinetic Rate-Law Parameters Used to Simulate Long-Term Weathering of ILAW Glass. Erratum

2016 ◽  
Author(s):  
Gary L. Smith
Keyword(s):  
Sensitivity Analysis ◽  
Kinetic Rate ◽  
Rate Law

scholarly journals Robot-assisted thoracic surgery versus video-assisted thoracic surgery for lung lobectomy or segmentectomy in patients with non-small cell lung cancer: a meta-analysis

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jianglei Ma ◽  
Xiaoyao Li ◽  
Shifu Zhao ◽  
Jiawei Wang ◽  
Wujia Zhang ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Sensitivity Analysis ◽  
Thoracic Surgery ◽  
Conversion Rate ◽  
Meta Analysis ◽  
Small Cell ◽  
Small Cell Lung ◽  
Robot Assisted ◽  
Short Term

Abstract Background It remains no clear conclusion about which is better between robot-assisted thoracic surgery (RATS) and video-assisted thoracic surgery (VATS) for the treatment of patients with non-small cell lung cancer (NSCLC). Therefore, this meta-analysis aimed to compare the short-term and long-term efficacy between RATS and VATS for NSCLC. Methods Pubmed, Cochrane Library, Embase, China National Knowledge Infrastructure (CNKI), Medline, and Web of Science databases were comprehensively searched for studies published before December 2020. The quality of the articles was evaluated using the Newcastle-Ottawa Scale (NOS) and the data analyzed using the Review Manager 5.3 software. Fixed or random effect models were applied according to heterogeneity. Subgroup analysis and sensitivity analysis were conducted. Results A total of 18 studies including 11,247 patients were included in the meta-analyses, of which 5114 patients were in the RATS group and 6133 in the VATS group. Compared with VATS, RATS was associated with less blood loss (WMD = − 50.40, 95% CI -90.32 ~ − 10.48, P = 0.010), lower conversion rate (OR = 0.50, 95% CI 0.43 ~ 0.60, P < 0.001), more harvested lymph nodes (WMD = 1.72, 95% CI 0.63 ~ 2.81, P = 0.002) and stations (WMD = 0.51, 95% CI 0.15 ~ 0.86, P = 0.005), shorter duration of postoperative chest tube drainage (WMD = − 0.61, 95% CI -0.78 ~ − 0.44, P < 0.001) and hospital stay (WMD = − 1.12, 95% CI -1.58 ~ − 0.66, P < 0.001), lower overall complication rate (OR = 0.90, 95% CI 0.83 ~ 0.99, P = 0.020), lower recurrence rate (OR = 0.51, 95% CI 0.36 ~ 0.72, P < 0.001), and higher cost (WMD = 3909.87 USD, 95% CI 3706.90 ~ 4112.84, P < 0.001). There was no significant difference between RATS and VATS in operative time, mortality, overall survival (OS), and disease-free survival (DFS). Sensitivity analysis showed that no significant differences were found between the two techniques in conversion rate, number of harvested lymph nodes and stations, and overall complication. Conclusions The results revealed that RATS is a feasible and safe technique compared with VATS in terms of short-term and long-term outcomes. Moreover, more randomized controlled trials comparing the two techniques with rigorous study designs are still essential to evaluate the value of robotic surgery for NSCLC.

A methodology for optimizing modeling configuration in the numerical modeling of oil concentrations in underwater blowouts: a North Sea case study

2021 ◽  
Author(s):  
Andrés Martínez
Keyword(s):  
Sensitivity Analysis ◽  
Numerical Modeling ◽  
High Resolution ◽  
North Sea ◽  
Oil And Gas ◽  
Data Bases ◽  
Lagrangian Trajectory ◽  
Number Of Particles

&lt;p&gt;&lt;strong&gt;A METHODOLOGY FOR OPTIMIZING MODELING CONFIGURATION IN THE NUMERICAL MODELING OF OIL CONCENTRATIONS IN UNDERWATER BLOWOUTS: A NORTH SEA CASE STUDY&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;Andr&amp;#233;s Mart&amp;#237;nez&lt;sup&gt;a,*&lt;/sup&gt;, Ana J. Abascal&lt;sup&gt;a&lt;/sup&gt;, Andr&amp;#233;s Garc&amp;#237;a&lt;sup&gt;a&lt;/sup&gt;, Beatriz P&amp;#233;rez-D&amp;#237;az&lt;sup&gt;a&lt;/sup&gt;, Germ&amp;#225;n Arag&amp;#243;n&lt;sup&gt;a&lt;/sup&gt;, Ra&amp;#250;l Medina&lt;sup&gt;a&lt;/sup&gt;&lt;/p&gt;&lt;p&gt;&lt;sup&gt;a&lt;/sup&gt;IHCantabria - Instituto de Hidr&amp;#225;ulica Ambiental de la Universidad de Cantabria, Avda. Isabel Torres, 15, 39011 Santander, Spain&lt;/p&gt;&lt;p&gt;&lt;sup&gt;* &lt;/sup&gt;Corresponding author: [email protected]&lt;/p&gt;&lt;p&gt;Underwater oil and gas blowouts are not easy to repair. It may take months before the well is finally capped, releasing large amounts of oil into the marine environment. In addition, persistent oils (crude oil, fuel oil, etc.) break up and dissipate slowly, so they often reach the shore before the cleanup is completed, affecting vasts extension of seas-oceans, just as posing a major threat to marine organisms.&lt;/p&gt;&lt;p&gt;On account of the above, numerical modeling of underwater blowouts demands great computing power. High-resolution, long-term data bases of wind-ocean currents are needed to be able to properly model the trajectory of the spill at both regional (open sea) and local level (coastline), just as to account for temporal variability. Moreover, a large number of particles, just as a high-resolution grid, are unavoidable in order to ensure accurate modeling of oil concentrations, of utmost importance in risk assessment, so that threshold concentrations can be established (threshold concentrations tell you what level of exposure to a compound could harm marine organisms).&lt;/p&gt;&lt;p&gt;In this study, an innovative methodology has been accomplished for the purpose of optimizing modeling configuration: number of particles and grid resolution, in the modeling of an underwater blowout, with a view to accurately represent oil concentrations, especially when threshold concentrations are considered. In doing so, statistical analyses (dimensionality reduction and clustering techniques), just as numerical modeling, have been applied.&lt;/p&gt;&lt;p&gt;It is composed of the following partial steps: (i) classification of i representative clusters of forcing patterns (based on PCA and K-means algorithms) from long-term wind-ocean current hindcast data bases, so that forcing variability in the study area is accounted for; (ii) definition of j modeling scenarios, based on key blowout parameters (oil type, flow rate, etc.) and modeling configuration (number of particles and grid resolution); (iii) Lagrangian trajectory modeling of the combination of the i clusters of forcing patterns and the j modeling scenarios; (iv) sensitivity analysis of the Lagrangian trajectory model output: oil concentrations, &amp;#160;to modeling configuration; (v) finally, as a result, the optimal modeling configuration, given a certain underwater blowout (its key parameters), is provided.&lt;/p&gt;&lt;p&gt;It has been applied to a hypothetical underwater blowout in the North Sea, one of the world&amp;#8217;s most active seas in terms of offshore oil and gas exploration and production. A 5,000 cubic meter per day-flow rate oil spill, flowing from the well over a 15-day period, has been modeled (assuming a 31-day period of subsequent drift for a 46-day modeling). Moreover, threshold concentrations of 0.1, 0.25, 1 and 10 grams per square meter have been applied in the sensitivity analysis. The findings of this study stress the importance of modeling configuration in accurate modeling of oil concentrations, in particular if lower threshold concentrations are considered.&lt;/p&gt;

Comparison of the kinetic rate law parameters for the dissolution of natural and synthetic autunite in the presence of aqueous bicarbonate ions

2013 ◽  
Vol 351 ◽  
pp. 299-309 ◽  
Author(s):  
Ravi K.P. Gudavalli ◽  
Yelena P. Katsenovich ◽  
Dawn M. Wellman ◽  
Melina Idarraga ◽  
Leonel E. Lagos ◽  
...  
Keyword(s):  
Kinetic Rate ◽  
Rate Law ◽  
Bicarbonate Ions ◽  
Natural And Synthetic

scholarly journals Origins of Deviations from Transition-State Theory: Formulating a New Kinetic Rate Law for Dissolution of Silicates

2003 ◽  
Author(s):  
David London ◽  
G B Morgan ◽  
J P Icenhower ◽  
B P McGrail ◽  
A Luttge
Keyword(s):  
Transition State ◽  
Transition State Theory ◽  
State Theory ◽  
Kinetic Rate ◽  
Rate Law

Disentangling uncertainties in risk-based planning of water resources in the UK

2021 ◽  
Author(s):  
Francesca Pianosi ◽  
Andres Penuela-Fernandez ◽  
Christopher Hutton
Keyword(s):  
Decision Making ◽  
Sensitivity Analysis ◽  
Monte Carlo ◽  
Water Resources ◽  
Water Resources Planning ◽  
Adaptive Planning ◽  
Water Companies ◽  
The Uk ◽  
Resources Planning

&lt;p&gt;Proper consideration of uncertainty has become a cornerstone of model-informed planning of water resource systems. In the UK Government&amp;#8217;s 2020 Water Resources Planning Guidelines, the word &amp;#8220;uncertainty&amp;#8221; appears 48 times in 82 pages. This emphasis on uncertainty aligns with the increasing adoption by UK water companies of a &amp;#8220;risk-based&amp;#8221; approach to their long-term decision-making, in order to handle uncertainties in supply-demand estimation, climate change, population growth, etc. The term &amp;#8220;risk-based&amp;#8221; covers a range of methods - such as &amp;#8220;info-gap&amp;#8221;, &amp;#8220;robust decision-making&amp;#8221; or &amp;#8220;system sensitivity analysis&amp;#8221; - that come under different names but largely share a common rationale, essentially based on the use of Monte Carlo simulation. This shift in thinking from previous (deterministic) &amp;#8220;worst-case&amp;#8221; approach to a &amp;#8220;risk-based&amp;#8221; one is important and has the potential to significantly improve water resources planning practice. However its implementation is diminished by a certain lack of clarity about the terminology in use and about the concrete differences (and similarities) among methods. On top of these difficulties, in the next planning-cycle (2021-2026) two further step changes are introduced: (1) water companies are requested to move from a cost-efficiency approach focused on achieving the supply-demand balance, towards a fully multi-criteria approach that more explicitly encompasses other objectives including environmental sustainability; (2) as a further way to handle long-term uncertainties, they are required to embrace an &amp;#8220;adaptive planning&amp;#8221; approach. These changes will introduce two new sets of uncertainties around the robust quantification of criteria, particularly environmental ones, and around the attribution of weights to different criteria. This urgently calls for establishing structured approaches to quantify not only the uncertainty in model outputs, but also the sensitivity of those outputs to different forms of uncertainty in the modelling chain that mostly control the variability of the final outcome &amp;#8211; the &amp;#8220;best value&amp;#8221; plan. Without this understanding of critical uncertainties, the risk is that huge efforts are invested on characterising and/or reducing uncertainties that later turn out to have little impact on the final outcome; or that water managers fall back to using oversimplified representation of those uncertainties as a way to escape the huge modelling burden. In this work, we aim at starting to establish a common rationale to &amp;#8220;risk-based&amp;#8221; methods within the context of a fully multi-criteria approach. We use a proof-of-concept example of a reservoir system in the South-West of England to demonstrate the use of global (i.e. Monte Carlo based) sensitivity analysis to simultaneously quantify output uncertainty and sensitivity, and identify robust decisions. We also discuss the potential of this approach to inform the construction of a &amp;#8220;decision tree&amp;#8221; for adaptive planning.&lt;/p&gt;

Towards a Methodology for Monitoring and Analyzing the Supply Chain Behavior

2011 ◽  
pp. 186-208
Author(s):  
Reinaldo Moraga ◽  
Luis Rabelo ◽  
Alfonso Sarmiento
Keyword(s):  
Neural Networks ◽  
Sensitivity Analysis ◽  
Supply Chain ◽  
System Dynamics ◽  
Eigenvalue Analysis ◽  
Background Information ◽  
Short And Long Term ◽  
And Performance

In this chapter, the authors present general steps towards a methodology that contributes to the advancement of prediction and mitigation of undesirable supply chain behavior within short- and long- term horizons by promoting a better understanding of the structure that determines the behavior modes. Through the integration of tools such as system dynamics, neural networks, eigenvalue analysis, and sensitivity analysis, this methodology (1) captures the dynamics of the supply chain, (2) detects changes and predicts the behavior based on these changes, and (3) defines needed modifications to mitigate the unwanted behaviors and performance. In the following sections, some background information is given from literature, the general steps of the proposed methodology are discussed, and finally a case study is briefly summarized.

Cost-effectiveness analysis: comparing single-level cervical disc replacement and single-level anterior cervical discectomy and fusion

2013 ◽  
Vol 19 (5) ◽  
pp. 546-554 ◽  
Author(s):  
Sheeraz A. Qureshi ◽  
Steven McAnany ◽  
Vadim Goz ◽  
Steven M. Koehler ◽  
Andrew C. Hecht
Keyword(s):  
Sensitivity Analysis ◽  
Cost Effectiveness ◽  
Cost Effective ◽  
Anterior Cervical Discectomy ◽  
Disc Replacement ◽  
Cervical Disc ◽  
Reference Case ◽  
Cervical Disc Replacement ◽  
Single Level

Object In recent years, there has been increased interest in the use of cervical disc replacement (CDR) as an alternative to anterior cervical discectomy and fusion (ACDF). While ACDF is a proven intervention for patients with myelopathy or radiculopathy, it does have inherent limitations. Cervical disc replacement was designed to preserve motion, avoid the limitations of fusion, and theoretically allow for a quicker return to activity. A number of recently published systematic reviews and randomized controlled trials have demonstrated positive clinical results for CDR, but no studies have revealed which of the 2 treatment strategies is more cost-effective. The purpose of this study was to evaluate the cost-effectiveness of CDR and ACDF by using the power of decision analysis. Additionally, the authors aimed to identify the most critical factors affecting procedural cost and effectiveness and to define thresholds for durability and function to focus and guide future research. Methods The authors created a surgical decision model for the treatment of single-level cervical disc disease with associated radiculopathy. The literature was reviewed to identify possible outcomes and their likelihood following CDR and ACDF. Health state utility factors were determined from the literature and assigned to each possible outcome, and procedural effectiveness was expressed in units of quality-adjusted life years (QALYs). Using ICD-9 procedure codes and data from the Nationwide Inpatient Sample, the authors calculated the median cost of hospitalization by multiplying hospital charges by the hospital-specific cost-to-charge ratio. Gross physician costs were determined from the mean Medicare reimbursement for each current procedural terminology (CPT) code. Uncertainty as regards both cost and effectiveness numbers was assessed using sensitivity analysis. Results In the reference case, the model assumed a 20-year duration for the CDR prosthesis. Cervical disc replacement led to higher average QALYs gained at a lower cost to society if both strategies survived for 20 years ($3042/QALY for CDR vs $8760/QALY for ACDF). Sensitivity analysis revealed that CDR needed to survive at least 9.75 years to be considered a more cost-effective strategy than ACDF. Cervical disc replacement becomes an acceptable societal strategy as the prosthesis survival time approaches 11 years and the $50,000/QALY gained willingness-to-pay threshold is crossed. Sensitivity analysis also indicated that CDR must provide a utility state of at least 0.796 to be cost-effective. Conclusions Both CDR and ACDF were shown to be cost-effective procedures in the reference case. Results of the sensitivity analysis indicated that CDR must remain functional for at least 14 years to establish greater cost-effectiveness than ACDF. Since the current literature has yet to demonstrate with certainty the actual durability and long-term functionality of CDR, future long-term studies are required to validate the present analysis.

Alliance Concrete: Just One More Thing

2017 ◽  
pp. 1-5
Author(s):  
Marc L. Lipson
Keyword(s):  
Sensitivity Analysis ◽  
Financial Statements ◽  
Parent Company ◽  
Capital Costs ◽  
Financing Choices ◽  
Operating Decisions ◽  
One Year ◽  
Ready Mix Concrete

After having negotiated major financial and operating decisions with its parent company, the CFO of this small ready-mix concrete subsidiary is asked to provide a valuation of the subsidiary. A one-year forecast of financial statements is provided along with information on long-term operating expectations and capital costs. This otherwise straightforward valuation exercise is enhanced by (1) the need to select between the parent- or comparable-firm costs of capital, (2) sufficient guidance to perform an illuminating sensitivity analysis, and (3) a sufficiently clear and rich context in which to illustrate the linkages between operating and financing choices. A teaching note and instructor and student Excel spreadsheets are available.

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