The Standard Capacity Model: Towards a Polyhedron Representation of Container Vessel Capacity

2018 ◽  
pp. 175-190 ◽  
Author(s):  
Rune Møller Jensen ◽  
Mai Lise Ajspur
Keyword(s):  
Capacity Model ◽  
Vessel Capacity

Molecular Dynamics Using Non-Variational Polarizable Force Fields: Theory, Periodic Boundary Conditions Implementation and Application to the Bond Capacity Model

2019 ◽  
Author(s):  
Pier Paolo Poier ◽  
Louis Lagardere ◽  
Jean-Philip Piquemal ◽  
Frank Jensen
Keyword(s):  
Boundary Conditions ◽  
Periodic Boundary ◽  
Force Fields ◽  
Periodic Boundary Conditions ◽  
Computational Effort ◽  
Polarizable Force Fields ◽  
Energy Models ◽  
Capacity Model ◽  
Energy Gradient ◽  
Polarization Models

<div> <div> <div> <p>We extend the framework for polarizable force fields to include the case where the electrostatic multipoles are not determined by a variational minimization of the electrostatic energy. Such models formally require that the polarization response is calculated for all possible geometrical perturbations in order to obtain the energy gradient required for performing molecular dynamics simulations. </p><div> <div> <div> <p>By making use of a Lagrange formalism, however, this computational demanding task can be re- placed by solving a single equation similar to that for determining the electrostatic variables themselves. Using the recently proposed bond capacity model that describes molecular polarization at the charge-only level, we show that the energy gradient for non-variational energy models with periodic boundary conditions can be calculated with a computational effort similar to that for variational polarization models. The possibility of separating the equation for calculating the electrostatic variables from the energy expression depending on these variables without a large computational penalty provides flexibility in the design of new force fields. </p><div><div><div> </div> </div> </div> <p> </p><div> <div> <div> <p>variables themselves. Using the recently proposed bond capacity model that describes molecular polarization at the charge-only level, we show that the energy gradient for non-variational energy models with periodic boundary conditions can be calculated with a computational effort similar to that for variational polarization models. The possibility of separating the equation for calculating the electrostatic variables from the energy expression depending on these variables without a large computational penalty provides flexibility in the design of new force fields. </p> </div> </div> </div> </div> </div> </div> </div> </div> </div>

Distinguishing The Cognitive Processes Of Mindfulness: Developing A Standardised Mindfulness Technique For Use In Longitudinal Randomised Control Trials

2019 ◽  
Author(s):  
Ben Isbel ◽  
Mathew J Summers
Keyword(s):  
Cognitive Processes ◽  
Mindfulness Training ◽  
Mindfulness Practice ◽  
Explanatory Framework ◽  
Cognitive Faculty ◽  
Metacognitive Processes ◽  
Capacity Model ◽  
Developmental Progression ◽  
Open Monitoring ◽  
Randomised Control Trials

A capacity model of mindfulness is adopted to differentiate the cognitive faculty of mindfulness from the metacognitive processes required to cultivate this faculty in mindfulness training. The model provides an explanatory framework incorporating both the developmental progression from focussed attention to open monitoring styles of mindfulness practice, along with the development of equanimity and insight. A standardised technique for activating these processes without the addition of secondary components is then introduced. Mindfulness-based interventions currently available for use in randomised control trials introduce components ancillary to the cognitive processes of mindfulness, limiting their ability to draw clear causative inferences. The standardised technique presented here does not introduce such ancillary factors, rendering it a valuable tool with which to investigate the processes activated in this practice.

scholarly journals Construction of a demand and capacity model for intensive care and hospital ward beds, and mortality from COVID-19

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Christopher Martin ◽  
Stuart McDonald ◽  
Steve Bale ◽  
Michiel Luteijn ◽  
Rahul Sarkar
Keyword(s):  
Intensive Care ◽  
National Level ◽  
Direct Consequence ◽  
Hospital Ward ◽  
Model Parameters ◽  
Capacity Model ◽  
New Variant ◽  
Pessimistic Scenario ◽  
Demand And Capacity ◽  
Excess Deaths

Abstract Background This paper describes a model for estimating COVID-19 related excess deaths that are a direct consequence of insufficient hospital ward bed and intensive care unit (ICU) capacity. Methods Compartmental models were used to estimate deaths under different combinations of ICU and ward care required and received in England up to late April 2021. Model parameters were sourced from publicly available government information and organisations collating COVID-19 data. A sub-model was used to estimate the mortality scalars that represent increased mortality due to insufficient ICU or general ward bed capacity. Three illustrative scenarios for admissions numbers, ‘Optimistic’, ‘Middling’ and ‘Pessimistic’, were modelled and compared with the subsequent observations to the 3rd February. Results The key output was the demand and capacity model described. There were no excess deaths from a lack of capacity in the ‘Optimistic’ scenario. Several of the ‘Middling’ scenario applications resulted in excess deaths—up to 597 deaths (0.6% increase) with a 20% reduction compared to best estimate ICU capacity. All the ‘Pessimistic’ scenario applications resulted in excess deaths, ranging from 49,178 (17.0% increase) for a 20% increase in ward bed availability, to 103,735 (35.8% increase) for a 20% shortfall in ward bed availability. These scenarios took no account of the emergence of the new, more transmissible, variant of concern (b.1.1.7). Conclusions Mortality is increased when hospital demand exceeds available capacity. No excess deaths from breaching capacity would be expected under the ‘Optimistic’ scenario. The ‘Middling’ scenario could result in some excess deaths—up to a 0.7% increase relative to the total number of deaths. The ‘Pessimistic’ scenario would have resulted in significant excess deaths. Our sensitivity analysis indicated a range between 49,178 (17% increase) and 103,735 (35.8% increase). Given the new variant, the pessimistic scenario appeared increasingly likely and could have resulted in a substantial increase in the number of COVID-19 deaths. In the event, it would appear that capacity was not breached at any stage at a national level with no excess deaths. it will remain unclear if minor local capacity breaches resulted in any small number of excess deaths.

scholarly journals Improvement on Load-Induced Cascading Failure in Asymmetrical Interdependent Networks: Modeling and Analysis

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Haiyan Han ◽  
Rennong Yang
Keyword(s):  
Load Capacity ◽  
Small World ◽  
Cascading Failure ◽  
Modeling And Analysis ◽  
Interdependent Networks ◽  
Interdependent Network ◽  
Capacity Model ◽  
Weight Structure ◽  
Edge Failure ◽  
Asymmetrical Model

Many real-world systems can be depicted as interdependent networks and they usually show an obvious property of asymmetry. Furthermore, node or edge failure can trigger load redistribution which leads to a cascade of failure in the whole network. In order to deeply investigate the load-induced cascading failure, firstly, an asymmetrical model of interdependent network consisting of a hierarchical weighted network and a WS small-world network is constructed. Secondly, an improved “load-capacity” model is applied for node failure and edge failure, respectively, followed by a series of simulations of cascading failure over networks in both interdependent and isolated statuses. The simulation results prove that the robustness in isolated network changes more promptly than that in the interdependent one. Network robustness is positively related to “capacity,” but negatively related to “load.” The hierarchical weight structure in the subnetwork leads to a “plateau” phenomenon in the progress of cascading failure.

The Effect of Spatial Ability on the Demand for Spatial Processing Resources

1986 ◽  
Vol 30 (7) ◽  
pp. 624-627 ◽  
Author(s):  
William L. Derrick ◽  
Thomas M. McCloy ◽  
William P. Marshak ◽  
Gretchen L. Seiler ◽  
Pamela A. Reddick
Keyword(s):  
Spatial Ability ◽  
Air Force ◽  
Air Force Academy ◽  
Ability Group ◽  
Capacity Model ◽  
Variable Capacity ◽  
Spatial Tasks ◽  
Processing Resources ◽  
Spatial Resources ◽  
The Relationship

Building upon previous research, this study examined the relationship between the deployment of spatial resources in the performance of spatial tasks and the level of spatial ability possessed by subjects. Ten Air Force Academy cadets, classified as either high or low in spatial ability by paper and pencil measures, performed tasks that presumably demanded spatial resources. Both the baseline and dual task level of performance was superior for the high spatial ability group. These findings are related to a variable capacity model of processing resources.

Fatigue Assessment of Mooring Chain Considering the Effects Of Mean Load and Corrosion

2021 ◽  
Author(s):  
Erling N. Lone ◽  
Thomas Sauder ◽  
Kjell Larsen ◽  
Bernt J. Leira
Keyword(s):  
Negative Impact ◽  
Fatigue Tests ◽  
Design Practice ◽  
Extended Formulation ◽  
Considerable Influence ◽  
Corrosion Condition ◽  
Capacity Model ◽  
Significant Negative Impact ◽  
The Mean ◽  
Mooring Chain

Abstract Results from full scale fatigue tests of offshore mooring chains performed in recent years have revealed considerable influence of both mean load and corrosion condition on the fatigue capacity. It has been shown that a reduction of the mean load gives an increase in fatigue life, whereas the corrosion experienced by used chains have a significant negative impact. Neither of these effects are properly addressed by current S-N design curves or design practice. This paper suggests an extended S-N curve formulation, that includes the effects of mean load and corrosion condition. The parameters of the extended formulation are estimated empirically from mooring chain test data that includes new and used chains, with various mean loads and with different degrees of corrosion. The fitted capacity model is then used for fatigue calculation for the mooring system of a semi-submersible, showing the importance of using realistic mean loads and mooring chain corrosion in fatigue assessments.

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