Static and dynamic model building explored in Baku

2020 ◽  
Vol 39 (1) ◽  
pp. 63-64
Author(s):  
Nazim Abdullayev ◽  
Peter Cook ◽  
Aleksandra Kramtseva
Keyword(s):  
Advisory Committee ◽  
Dynamic Model ◽  
Model Building ◽  
Technical Conference ◽  
Scale Modeling ◽  
Basin Scale

An SEG workshop titled, “Geophysical inputs to static and dynamic model building” was recently held in Baku, Azerbaijan. It was developed and supported by the SEG Eurasia Regional Advisory Committee. The workshop was conducted during the SPE Annual Caspian Technical Conference and was divided into three themes: integration of geophysical products, basin-scale modeling, and petrophysics.

scholarly journals Dynamic model updating (DMU) approach for statistical learning model building with missing data

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Rahi Jain ◽  
Wei Xu
Keyword(s):  
Missing Data ◽  
Dynamic Model ◽  
Statistical Models ◽  
Missing Values ◽  
Model Building ◽  
Model Updating ◽  
Biological Data ◽  
Bayesian Regression ◽  
Biological Research ◽  
Original Dataset

Abstract Background Developing statistical and machine learning methods on studies with missing information is a ubiquitous challenge in real-world biological research. The strategy in literature relies on either removing the samples with missing values like complete case analysis (CCA) or imputing the information in the samples with missing values like predictive mean matching (PMM) such as MICE. Some limitations of these strategies are information loss and closeness of the imputed values with the missing values. Further, in scenarios with piecemeal medical data, these strategies have to wait to complete the data collection process to provide a complete dataset for statistical models. Method and results This study proposes a dynamic model updating (DMU) approach, a different strategy to develop statistical models with missing data. DMU uses only the information available in the dataset to prepare the statistical models. DMU segments the original dataset into small complete datasets. The study uses hierarchical clustering to segment the original dataset into small complete datasets followed by Bayesian regression on each of the small complete datasets. Predictor estimates are updated using the posterior estimates from each dataset. The performance of DMU is evaluated by using both simulated data and real studies and show better results or at par with other approaches like CCA and PMM. Conclusion DMU approach provides an alternative to the existing approaches of information elimination and imputation in processing the datasets with missing values. While the study applied the approach for continuous cross-sectional data, the approach can be applied to longitudinal, categorical and time-to-event biological data.

scholarly journals Debris flow run-out simulation and analysis using a dynamic model

2018 ◽  
Vol 18 (2) ◽  
pp. 555-570 ◽  
Author(s):  
Raquel Melo ◽  
Theo van Asch ◽  
José L. Zêzere
Keyword(s):  
Debris Flow ◽  
Dynamic Model ◽  
Debris Flows ◽  
Back Analysis ◽  
Rheological Parameters ◽  
Economic Damage ◽  
Case Scenario ◽  
Worst Case ◽  
Basin Scale ◽  
Central Portugal

Abstract. Only two months after a huge forest fire occurred in the upper part of a valley located in central Portugal, several debris flows were triggered by intense rainfall. The event caused infrastructural and economic damage, although no lives were lost. The present research aims to simulate the run-out of two debris flows that occurred during the event as well as to calculate via back-analysis the rheological parameters and the excess rain involved. Thus, a dynamic model was used, which integrates surface runoff, concentrated erosion along the channels, propagation and deposition of flow material. Afterwards, the model was validated using 32 debris flows triggered during the same event that were not considered for calibration. The rheological and entrainment parameters obtained for the most accurate simulation were then used to perform three scenarios of debris flow run-out on the basin scale. The results were confronted with the existing buildings exposed in the study area and the worst-case scenario showed a potential inundation that may affect 345 buildings. In addition, six streams where debris flow occurred in the past and caused material damage and loss of lives were identified.

scholarly journals Regulation of phytoplankton carbon to chlorophyll ratio by light, nutrients and temperature in the equatorial Pacific Ocean: a basin-scale model

2008 ◽  
Vol 5 (5) ◽  
pp. 3869-3903 ◽  
Author(s):  
X. J. Wang ◽  
M. Behrenfeld ◽  
R. Le Borgne ◽  
R. Murtugudde ◽  
E. Boss
Keyword(s):  
Pacific Ocean ◽  
Dynamic Model ◽  
Warm Pool ◽  
Temporal Variations ◽  
Equatorial Pacific ◽  
Spatial And Temporal Variations ◽  
Scale Model ◽  
Equatorial Pacific Ocean ◽  
Eastern Equatorial Pacific ◽  
Basin Scale

Abstract. The complex effects of light, nutrients and temperature lead to a variable carbon to chlorophyll (C:Chl) ratio in phytoplankton cells. Using field data collected in the equatorial Pacific, we derived a new dynamic model with a non-steady C:Chl ratio as a function of irradiance, nitrate, iron, and temperature. The dynamic model is implemented into a basin-scale ocean circulation-biogeochemistry model and tested in the equatorial Pacific Ocean. The model reproduces well the general features of phytoplankton dynamics in this region. For instance, the simulated deep chlorophyll maximum (DCM) is much deeper in the western warm pool (~100 m) than in the eastern equatorial Pacific (~50 m). The model also shows the ability to reproduce chlorophyll, including not only the zonal, meridional and vertical variations, but also the interannual variability. This study demonstrates that combination of nitrate and iron regulates the spatial and temporal variations in the phytoplankton C:Chl ratio. Particularly, nitrate is responsible for the high C:Chl ratio in the western warm pool while iron is responsible for the frontal features in the C:Chl ratio between the warm pool and the upwelling region. In addition, iron plays a dominant role in regulating the spatial and temporal variations of the C:Chl ratio in the central and eastern equatorial Pacific. While temperature has a relatively small effect on the C:Chl ratio, light is primarily responsible for the vertical decrease of phytoplankton C:Chl ratio in the euphotic zone.

Control of Flexible Payloads Grasped by Actuated Grippers Undergoing Large Rigid-Body Motions: Part II — Controllability and Observability

2002 ◽  
Author(s):  
Edward J. Park ◽  
James K. Mills
Keyword(s):  
Rigid Body ◽  
Dynamic Model ◽  
Time Scale ◽  
Body Motion ◽  
Deformation Control ◽  
Scale Modeling ◽  
Fixed Interface ◽  
Controllability And Observability ◽  
Scale Behavior ◽  
Selection Of

Part I of this work models the dynamics of a flexible payload grasped by an actuated gripper undergoing large rigid body motion by a robotic manipulator. In Part II, the controllability and observability conditions of the system are discussed. In Part I, the dynamic model of the actuated flexible payload is derived using the component mode synthesis (CMS) method with addition of actuator constraint, fixed-interface vibration and quasi-static modes. Here, the two-time scale modeling (TSM) technique is employed taking advantage of the two-time scale behavior between the quasi-static modes and vibration modes in the dynamic model. Due to the complexity of the resulting system, the controllability and observability conditions are not trivial. Hence, the controllability and observability study addressed herein becomes essential in showing the advantages of using the CMS and TSM techniques in control system design for the problem. A simulation example demonstrates that simultaneous vibration and quasi-static deformation control is achievable by proper selection of each type of modes.

scholarly journals Regulation of phytoplankton carbon to chlorophyll ratio by light, nutrients and temperature in the Equatorial Pacific Ocean: a basin-scale model

2009 ◽  
Vol 6 (3) ◽  
pp. 391-404 ◽  
Author(s):  
X. J. Wang ◽  
M. Behrenfeld ◽  
R. Le Borgne ◽  
R. Murtugudde ◽  
E. Boss
Keyword(s):  
Pacific Ocean ◽  
Dynamic Model ◽  
Warm Pool ◽  
Temporal Variations ◽  
Equatorial Pacific ◽  
Spatial And Temporal Variations ◽  
Scale Model ◽  
Equatorial Pacific Ocean ◽  
Eastern Equatorial Pacific ◽  
Basin Scale

Abstract. The complex effects of light, nutrients and temperature lead to a variable carbon to chlorophyll (C:Chl) ratio in phytoplankton cells. Using field data collected in the Equatorial Pacific, we derived a new dynamic model with a non-steady C:Chl ratio as a function of irradiance, nitrate, iron, and temperature. The dynamic model is implemented into a basin-scale ocean circulation-biogeochemistry model and tested in the Equatorial Pacific Ocean. The model reproduces well the general features of phytoplankton dynamics in this region. For instance, the simulated deep chlorophyll maximum (DCM) is much deeper in the western warm pool (~100 m) than in the Eastern Equatorial Pacific (~50 m). The model also shows the ability to reproduce chlorophyll, including not only the zonal, meridional and vertical variations, but also the interannual variability. This modeling study demonstrates that combination of nitrate and iron regulates the spatial and temporal variations in the phytoplankton C:Chl ratio in the Equatorial Pacific. Sensitivity simulations suggest that nitrate is mainly responsible for the high C:Chl ratio in the western warm pool while iron is responsible for the frontal features in the C:Chl ratio between the warm pool and the upwelling region. In addition, iron plays a dominant role in regulating the spatial and temporal variations of the C:Chl ratio in the Central and Eastern Equatorial Pacific. While temperature has a relatively small effect on the C:Chl ratio, light is primarily responsible for the vertical decrease of phytoplankton C:Chl ratio in the euphotic zone.

Basin-scale integrated earth-model building using rock-physics constraints

2016 ◽  
Vol 35 (2) ◽  
pp. 141-145 ◽  
Author(s):  
Yangjun (Kevin) Liu ◽  
Nader Chand Dutta ◽  
Denes Vigh ◽  
Jerry Kapoor ◽  
Cara Hunter ◽  
...  
Keyword(s):  
Model Building ◽  
Rock Physics ◽  
Earth Model ◽  
Basin Scale

Basin-scale modeling of CO2 storage using models of varying complexity

2014 ◽  
Vol 20 ◽  
pp. 73-86 ◽  
Author(s):  
Xinwo Huang ◽  
Karl W. Bandilla ◽  
Michael A. Celia ◽  
Stefan Bachu
Keyword(s):  
Co2 Storage ◽  
Scale Modeling ◽  
Basin Scale
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