Alternative to Ritt's pseudodivision for finding the input-output equations of multi-output models.

Science.gov (United States)

Meshkat, Nicolette; Anderson, Chris; DiStefano, Joseph J

2012-09-01

Differential algebra approaches to structural identifiability analysis of a dynamic system model in many instances heavily depend upon Ritt's pseudodivision at an early step in analysis. The pseudodivision algorithm is used to find the characteristic set, of which a subset, the input-output equations, is used for identifiability analysis. A simpler algorithm is proposed for this step, using Gröbner Bases, along with a proof of the method that includes a reduced upper bound on derivative requirements. Efficacy of the new algorithm is illustrated with several biosystem model examples. Copyright © 2012 Elsevier Inc. All rights reserved.

Finding Furfural Hydrogenation Catalysts via Predictive Modelling

OpenAIRE

Strassberger, Zea; Mooijman, Maurice; Ruijter, Eelco; Alberts, Albert H; Maldonado, Ana G; Orru, Romano V A; Rothenberg, Gadi

2010-01-01

Abstract We combine multicomponent reactions, catalytic performance studies and predictive modelling to find transfer hydrogenation catalysts. An initial set of 18 ruthenium-carbene complexes were synthesized and screened in the transfer hydrogenation of furfural to furfurol with isopropyl alcohol complexes gave varied yields, from 62% up to >99.9%, with no obvious structure/activity correlations. Control experiments proved that the carbene ligand remains coordinated to the ruthenium centre t...

BALANCED SCORECARDS EVALUATION MODEL THAT INCLUDES ELEMENTS OF ENVIRONMENTAL MANAGEMENT SYSTEM USING AHP MODEL

Directory of Open Access Journals (Sweden)

Jelena Jovanović

2010-03-01

Full Text Available The research is oriented on improvement of environmental management system (EMS using BSC (Balanced Scorecard model that presents strategic model of measurem ents and improvement of organisational performance. The research will present approach of objectives and environmental management me trics involvement (proposed by literature review in conventional BSC in "Ad Barska plovi dba" organisation. Further we will test creation of ECO-BSC model based on business activities of non-profit organisations in order to improve envir onmental management system in parallel with other systems of management. Using this approach we may obtain 4 models of BSC that includ es elements of environmen tal management system for AD "Barska plovidba". Taking into acc ount that implementation and evaluation need long period of time in AD "Barska plovidba", the final choice will be based on 14598 (Information technology - Software product evaluation and ISO 9126 (Software engineering - Product quality using AHP method. Those standards are usually used for evaluation of quality software product and computer programs that serve in organisation as support and factors for development. So, AHP model will be bas ed on evolution criteria based on suggestion of ISO 9126 standards and types of evaluation from two evaluation teams. Members of team & will be experts in BSC and environmental management system that are not em ployed in AD "Barska Plovidba" organisation. The members of team 2 will be managers of AD "Barska Plovidba" organisation (including manage rs from environmental department. Merging results based on previously cr eated two AHP models, one can obtain the most appropriate BSC that includes elements of environmental management system. The chosen model will present at the same time suggestion for approach choice including ecological metrics in conventional BSC model for firm that has at least one ECO strategic orientation.

Double-gate junctionless transistor model including short-channel effects

International Nuclear Information System (INIS)

Paz, B C; Pavanello, M A; Ávila-Herrera, F; Cerdeira, A

2015-01-01

This work presents a physically based model for double-gate junctionless transistors (JLTs), continuous in all operation regimes. To describe short-channel transistors, short-channel effects (SCEs), such as increase of the channel potential due to drain bias, carrier velocity saturation and mobility degradation due to vertical and longitudinal electric fields, are included in a previous model developed for long-channel double-gate JLTs. To validate the model, an analysis is made by using three-dimensional numerical simulations performed in a Sentaurus Device Simulator from Synopsys. Different doping concentrations, channel widths and channel lengths are considered in this work. Besides that, the series resistance influence is numerically included and validated for a wide range of source and drain extensions. In order to check if the SCEs are appropriately described, besides drain current, transconductance and output conductance characteristics, the following parameters are analyzed to demonstrate the good agreement between model and simulation and the SCEs occurrence in this technology: threshold voltage (V TH ), subthreshold slope (S) and drain induced barrier lowering. (paper)

Early magnetic resonance imaging and histologic findings in a model of avascular necrosis of femoral head

Energy Technology Data Exchange (ETDEWEB)

Nakamura, Takuya [Kanazawa Univ. (Japan). School of Medicine

1997-12-01

The present study was performed to examine early MR images and histologic findings using a canine model of avascular necrosis of femoral head (ANFH). The ANFH model was surgically induced. At three days, 1, 2 and 4 weeks after surgery, the proximal femurs were excised. MR images were obtained in 4 dogs at 3 days and 7 dogs at each of the other intervals. Histologic examinations were performed on 7 dogs at each interval. Three days after surgery, MR showed almost no abnormal findings. Histologic changes included edematous bone marrow and bleeding in the bone marrow in some regions. One week after surgery, empty lacunae in trabecular bones and immature fibrous tissues in the bone marrow were seen in some cases, but appositional bone was not yet apparent. In only one case, abnormal MR findings -a ringlike pattern- were seen. Two weeks after surgery, 4 cases showed appositional bones on histology and abnormalities on MR images. Four weeks after surgery, fibrous tissues had matured and appositional bones had increased. Therefore, all 7 cases showed MR imaging abnormalities. Abnormal MR images included a ringlike pattern, and homogeneous and inhomogeneous patterns. These results indicated that MR imaging shows abnormality 2 weeks after surgery at the latest. (author)

Model for safety reports including descriptive examples

International Nuclear Information System (INIS)

1995-12-01

Several safety reports will be produced in the process of planning and constructing the system for disposal of high-level radioactive waste in Sweden. The present report gives a model, with detailed examples, of how these reports should be organized and what steps they should include. In the near future safety reports will deal with the encapsulation plant and the repository. Later reports will treat operation of the handling systems and the repository

Findings and Challenges in Fine-Resolution Large-Scale Hydrological Modeling

Science.gov (United States)

Her, Y. G.

2017-12-01

Fine-resolution large-scale (FL) modeling can provide the overall picture of the hydrological cycle and transport while taking into account unique local conditions in the simulation. It can also help develop water resources management plans consistent across spatial scales by describing the spatial consequences of decisions and hydrological events extensively. FL modeling is expected to be common in the near future as global-scale remotely sensed data are emerging, and computing resources have been advanced rapidly. There are several spatially distributed models available for hydrological analyses. Some of them rely on numerical methods such as finite difference/element methods (FDM/FEM), which require excessive computing resources (implicit scheme) to manipulate large matrices or small simulation time intervals (explicit scheme) to maintain the stability of the solution, to describe two-dimensional overland processes. Others make unrealistic assumptions such as constant overland flow velocity to reduce the computational loads of the simulation. Thus, simulation efficiency often comes at the expense of precision and reliability in FL modeling. Here, we introduce a new FL continuous hydrological model and its application to four watersheds in different landscapes and sizes from 3.5 km2 to 2,800 km2 at the spatial resolution of 30 m on an hourly basis. The model provided acceptable accuracy statistics in reproducing hydrological observations made in the watersheds. The modeling outputs including the maps of simulated travel time, runoff depth, soil water content, and groundwater recharge, were animated, visualizing the dynamics of hydrological processes occurring in the watersheds during and between storm events. Findings and challenges were discussed in the context of modeling efficiency, accuracy, and reproducibility, which we found can be improved by employing advanced computing techniques and hydrological understandings, by using remotely sensed hydrological

Modelling a linear PM motor including magnetic saturation

NARCIS (Netherlands)

Polinder, H.; Slootweg, J.G.; Compter, J.C.; Hoeijmakers, M.J.

2002-01-01

The use of linear permanent-magnet (PM) actuators increases in a wide variety of applications because of the high force density, robustness and accuracy. The paper describes the modelling of a linear PM motor applied in, for example, wafer steppers, including magnetic saturation. This is important

Finding Furfural Hydrogenation Catalysts via Predictive Modelling

Science.gov (United States)

Strassberger, Zea; Mooijman, Maurice; Ruijter, Eelco; Alberts, Albert H; Maldonado, Ana G; Orru, Romano V A; Rothenberg, Gadi

2010-01-01

Abstract We combine multicomponent reactions, catalytic performance studies and predictive modelling to find transfer hydrogenation catalysts. An initial set of 18 ruthenium-carbene complexes were synthesized and screened in the transfer hydrogenation of furfural to furfurol with isopropyl alcohol complexes gave varied yields, from 62% up to >99.9%, with no obvious structure/activity correlations. Control experiments proved that the carbene ligand remains coordinated to the ruthenium centre throughout the reaction. Deuterium-labelling studies showed a secondary isotope effect (kH:kD=1.5). Further mechanistic studies showed that this transfer hydrogenation follows the so-called monohydride pathway. Using these data, we built a predictive model for 13 of the catalysts, based on 2D and 3D molecular descriptors. We tested and validated the model using the remaining five catalysts (cross-validation, R2=0.913). Then, with this model, the conversion and selectivity were predicted for four completely new ruthenium-carbene complexes. These four catalysts were then synthesized and tested. The results were within 3% of the model’s predictions, demonstrating the validity and value of predictive modelling in catalyst optimization. PMID:23193388

Modelling and control of a microgrid including photovoltaic and wind generation

Science.gov (United States)

Hussain, Mohammed Touseef

Extensive increase of distributed generation (DG) penetration and the existence of multiple DG units at distribution level have introduced the notion of micro-grid. This thesis develops a detailed non-linear and small-signal dynamic model of a microgrid that includes PV, wind and conventional small scale generation along with their power electronics interfaces and the filters. The models developed evaluate the amount of generation mix from various DGs for satisfactory steady state operation of the microgrid. In order to understand the interaction of the DGs on microgrid system initially two simpler configurations were considered. The first one consists of microalternator, PV and their electronics, and the second system consists of microalternator and wind system each connected to the power system grid. Nonlinear and linear state space model of each microgrid are developed. Small signal analysis showed that the large participation of PV/wind can drive the microgrid to the brink of unstable region without adequate control. Non-linear simulations are carried out to verify the results obtained through small-signal analysis. The role of the extent of generation mix of a composite microgrid consisting of wind, PV and conventional generation was investigated next. The findings of the smaller systems were verified through nonlinear and small signal modeling. A central supervisory capacitor energy storage controller interfaced through a STATCOM was proposed to monitor and enhance the microgrid operation. The potential of various control inputs to provide additional damping to the system has been evaluated through decomposition techniques. The signals identified to have damping contents were employed to design the supervisory control system. The controller gains were tuned through an optimal pole placement technique. Simulation studies demonstrate that the STATCOM voltage phase angle and PV inverter phase angle were the best inputs for enhanced stability boundaries.

Construction and evaluation of FiND, a fall risk prediction model of inpatients from nursing data.

Science.gov (United States)

Yokota, Shinichiroh; Ohe, Kazuhiko

2016-04-01

To construct and evaluate an easy-to-use fall risk prediction model based on the daily condition of inpatients from secondary use electronic medical record system data. The present authors scrutinized electronic medical record system data and created a dataset for analysis by including inpatient fall report data and Intensity of Nursing Care Needs data. The authors divided the analysis dataset into training data and testing data, then constructed the fall risk prediction model FiND from the training data, and tested the model using the testing data. The dataset for analysis contained 1,230,604 records from 46,241 patients. The sensitivity of the model constructed from the training data was 71.3% and the specificity was 66.0%. The verification result from the testing dataset was almost equivalent to the theoretical value. Although the model's accuracy did not surpass that of models developed in previous research, the authors believe FiND will be useful in medical institutions all over Japan because it is composed of few variables (only age, sex, and the Intensity of Nursing Care Needs items), and the accuracy for unknown data was clear. © 2016 Japan Academy of Nursing Science.

Olkiluoto surface hydrological modelling: Update 2012 including salt transport modelling

International Nuclear Information System (INIS)

Karvonen, T.

2013-11-01

Posiva Oy is responsible for implementing a final disposal program for spent nuclear fuel of its owners Teollisuuden Voima Oyj and Fortum Power and Heat Oy. The spent nuclear fuel is planned to be disposed at a depth of about 400-450 meters in the crystalline bedrock at the Olkiluoto site. Leakages located at or close to spent fuel repository may give rise to the upconing of deep highly saline groundwater and this is a concern with regard to the performance of the tunnel backfill material after the closure of the tunnels. Therefore a salt transport sub-model was added to the Olkiluoto surface hydrological model (SHYD). The other improvements include update of the particle tracking algorithm and possibility to estimate the influence of open drillholes in a case where overpressure in inflatable packers decreases causing a hydraulic short-circuit between hydrogeological zones HZ19 and HZ20 along the drillhole. Four new hydrogeological zones HZ056, HZ146, BFZ100 and HZ039 were added to the model. In addition, zones HZ20A and HZ20B intersect with each other in the new structure model, which influences salinity upconing caused by leakages in shafts. The aim of the modelling of long-term influence of ONKALO, shafts and repository tunnels provide computational results that can be used to suggest limits for allowed leakages. The model input data included all the existing leakages into ONKALO (35-38 l/min) and shafts in the present day conditions. The influence of shafts was computed using eight different values for total shaft leakage: 5, 11, 20, 30, 40, 50, 60 and 70 l/min. The selection of the leakage criteria for shafts was influenced by the fact that upconing of saline water increases TDS-values close to the repository areas although HZ20B does not intersect any deposition tunnels. The total limit for all leakages was suggested to be 120 l/min. The limit for HZ20 zones was proposed to be 40 l/min: about 5 l/min the present day leakages to access tunnel, 25 l/min from

Olkiluoto surface hydrological modelling: Update 2012 including salt transport modelling

Energy Technology Data Exchange (ETDEWEB)

Karvonen, T. [WaterHope, Helsinki (Finland)

2013-11-15

Posiva Oy is responsible for implementing a final disposal program for spent nuclear fuel of its owners Teollisuuden Voima Oyj and Fortum Power and Heat Oy. The spent nuclear fuel is planned to be disposed at a depth of about 400-450 meters in the crystalline bedrock at the Olkiluoto site. Leakages located at or close to spent fuel repository may give rise to the upconing of deep highly saline groundwater and this is a concern with regard to the performance of the tunnel backfill material after the closure of the tunnels. Therefore a salt transport sub-model was added to the Olkiluoto surface hydrological model (SHYD). The other improvements include update of the particle tracking algorithm and possibility to estimate the influence of open drillholes in a case where overpressure in inflatable packers decreases causing a hydraulic short-circuit between hydrogeological zones HZ19 and HZ20 along the drillhole. Four new hydrogeological zones HZ056, HZ146, BFZ100 and HZ039 were added to the model. In addition, zones HZ20A and HZ20B intersect with each other in the new structure model, which influences salinity upconing caused by leakages in shafts. The aim of the modelling of long-term influence of ONKALO, shafts and repository tunnels provide computational results that can be used to suggest limits for allowed leakages. The model input data included all the existing leakages into ONKALO (35-38 l/min) and shafts in the present day conditions. The influence of shafts was computed using eight different values for total shaft leakage: 5, 11, 20, 30, 40, 50, 60 and 70 l/min. The selection of the leakage criteria for shafts was influenced by the fact that upconing of saline water increases TDS-values close to the repository areas although HZ20B does not intersect any deposition tunnels. The total limit for all leakages was suggested to be 120 l/min. The limit for HZ20 zones was proposed to be 40 l/min: about 5 l/min the present day leakages to access tunnel, 25 l/min from

Study of a diffusion flamelet model, with preferential diffusion effects included

NARCIS (Netherlands)

Delhaye, S.; Somers, L.M.T.; Bongers, H.; Oijen, van J.A.; Goey, de L.P.H.; Dias, V.

2005-01-01

The non-premixed flamelet model of Peters [1] (model1), which does not include preferential diffusion effects is investigated. Two similar models are presented, but without the assumption of unity Lewis numbers. One of these models was derived by Peters & Pitsch [2] (model2), while the other one was

Finding regions of interest in pathological images: an attentional model approach

Science.gov (United States)

Gómez, Francisco; Villalón, Julio; Gutierrez, Ricardo; Romero, Eduardo

2009-02-01

This paper introduces an automated method for finding diagnostic regions-of-interest (RoIs) in histopathological images. This method is based on the cognitive process of visual selective attention that arises during a pathologist's image examination. Specifically, it emulates the first examination phase, which consists in a coarse search for tissue structures at a "low zoom" to separate the image into relevant regions.1 The pathologist's cognitive performance depends on inherent image visual cues - bottom-up information - and on acquired clinical medicine knowledge - top-down mechanisms -. Our pathologist's visual attention model integrates the latter two components. The selected bottom-up information includes local low level features such as intensity, color, orientation and texture information. Top-down information is related to the anatomical and pathological structures known by the expert. A coarse approximation to these structures is achieved by an oversegmentation algorithm, inspired by psychological grouping theories. The algorithm parameters are learned from an expert pathologist's segmentation. Top-down and bottom-up integration is achieved by calculating a unique index for each of the low level characteristics inside the region. Relevancy is estimated as a simple average of these indexes. Finally, a binary decision rule defines whether or not a region is interesting. The method was evaluated on a set of 49 images using a perceptually-weighted evaluation criterion, finding a quality gain of 3dB when comparing to a classical bottom-up model of attention.

SEEPAGE MODEL FOR PA INCLUDING DRIFT COLLAPSE

International Nuclear Information System (INIS)

C. Tsang

2004-01-01

The purpose of this report is to document the predictions and analyses performed using the seepage model for performance assessment (SMPA) for both the Topopah Spring middle nonlithophysal (Tptpmn) and lower lithophysal (Tptpll) lithostratigraphic units at Yucca Mountain, Nevada. Look-up tables of seepage flow rates into a drift (and their uncertainty) are generated by performing numerical simulations with the seepage model for many combinations of the three most important seepage-relevant parameters: the fracture permeability, the capillary-strength parameter 1/a, and the percolation flux. The percolation flux values chosen take into account flow focusing effects, which are evaluated based on a flow-focusing model. Moreover, multiple realizations of the underlying stochastic permeability field are conducted. Selected sensitivity studies are performed, including the effects of an alternative drift geometry representing a partially collapsed drift from an independent drift-degradation analysis (BSC 2004 [DIRS 166107]). The intended purpose of the seepage model is to provide results of drift-scale seepage rates under a series of parameters and scenarios in support of the Total System Performance Assessment for License Application (TSPA-LA). The SMPA is intended for the evaluation of drift-scale seepage rates under the full range of parameter values for three parameters found to be key (fracture permeability, the van Genuchten 1/a parameter, and percolation flux) and drift degradation shape scenarios in support of the TSPA-LA during the period of compliance for postclosure performance [Technical Work Plan for: Performance Assessment Unsaturated Zone (BSC 2002 [DIRS 160819], Section I-4-2-1)]. The flow-focusing model in the Topopah Spring welded (TSw) unit is intended to provide an estimate of flow focusing factors (FFFs) that (1) bridge the gap between the mountain-scale and drift-scale models, and (2) account for variability in local percolation flux due to

Atmosphere-soil-vegetation model including CO2 exchange processes: SOLVEG2

International Nuclear Information System (INIS)

Nagai, Haruyasu

2004-11-01

A new atmosphere-soil-vegetation model named SOLVEG2 (SOLVEG version 2) was developed to study the heat, water, and CO 2 exchanges between the atmosphere and land-surface. The model consists of one-dimensional multilayer sub-models for the atmosphere, soil, and vegetation. It also includes sophisticated processes for solar and long-wave radiation transmission in vegetation canopy and CO 2 exchanges among the atmosphere, soil, and vegetation. Although the model usually simulates only vertical variation of variables in the surface-layer atmosphere, soil, and vegetation canopy by using meteorological data as top boundary conditions, it can be used by coupling with a three-dimensional atmosphere model. In this paper, details of SOLVEG2, which includes the function of coupling with atmosphere model MM5, are described. (author)

Exclusive queueing model including the choice of service windows

Science.gov (United States)

Tanaka, Masahiro; Yanagisawa, Daichi; Nishinari, Katsuhiro

2018-01-01

In a queueing system involving multiple service windows, choice behavior is a significant concern. This paper incorporates the choice of service windows into a queueing model with a floor represented by discrete cells. We contrived a logit-based choice algorithm for agents considering the numbers of agents and the distances to all service windows. Simulations were conducted with various parameters of agent choice preference for these two elements and for different floor configurations, including the floor length and the number of service windows. We investigated the model from the viewpoint of transit times and entrance block rates. The influences of the parameters on these factors were surveyed in detail and we determined that there are optimum floor lengths that minimize the transit times. In addition, we observed that the transit times were determined almost entirely by the entrance block rates. The results of the presented model are relevant to understanding queueing systems including the choice of service windows and can be employed to optimize facility design and floor management.

Focal Pancreatitis Mimicking Pancreatic Mass: Magnetic Resonance Imaging (MRI)/Magnetic Resonance Cholangiopancreatography (MRCP) Findings Including Diffusion-Weighted MRI

International Nuclear Information System (INIS)

Momtahen, A.J.; Balci, N.C.; Alkaade, S.; Akduman, E.I.; Burton, F.R.

2008-01-01

Background: Focal pancreatitis (FP) is a confined inflammation that mimics a pancreatic mass. Its imaging diagnosis is important to avoid unnecessary procedures. Purpose: To describe the spectrum of magnetic resonance imaging (MRI)/magnetic resonance cholangiopancreatography (MRCP) and diffusion-weighted MRI (DWI) findings of focal pancreatitis mimicking pancreatic masses. Material and Methods: Findings of MRI/MRCP including DWI with a b value of 0 and 600 s/mm2 in 14 patients with pancreatic masses on MRI were retrospectively reviewed and compared to normal pancreas in 14 patients as a control group. Results: FP revealed hypointense signal intensity (SI) (3/14), hypo- to isointense SI (7/14), or isointense SI (4/14) on T1-weighted images, and hypointense SI (1/14), isointense SI (5/14), iso- to hyperintense SI (7/14), or hyperintense SI (1/14) on T2-weighted images compared to remaining pancreas (RP). MRCP images revealed dilatation of the common bile duct (CBD) and main pancreatic duct (MPD) (5/14), dilatation of the MPD only (3/14), dilatation of the CBD only (3/14), and normal MPD and CBD (3/14). Both FP and RP revealed three types of time-signal intensity curves: 1) rapid rise to a peak, with a rapid decline (FP=2, RP=4), 2) slow rise to a peak, followed by a slow decline (FP=5, RP=4), and 3) slower rise to a peak, with a slow decline or plateau (FP=7, RP=6). Mean apparent diffusion coefficient (ADC) values for FP and RP were 2.09±0.18 and 2.03±0.2x10 -3 mm 2 /s, respectively. ADC values of FP and RP revealed no significant difference. Conclusion: The spectrum of imaging findings of focal pancreatitis on MRI/MRCP including DWI was described. Findings of FP were not distinctive as compared to the remaining pancreas

Integrated Sachs-Wolfe effect in a quintessence cosmological model: Including anisotropic stress of dark energy

International Nuclear Information System (INIS)

Wang, Y. T.; Xu, L. X.; Gui, Y. X.

2010-01-01

In this paper, we investigate the integrated Sachs-Wolfe effect in the quintessence cold dark matter model with constant equation of state and constant speed of sound in dark energy rest frame, including dark energy perturbation and its anisotropic stress. Comparing with the ΛCDM model, we find that the integrated Sachs-Wolfe (ISW)-power spectrums are affected by different background evolutions and dark energy perturbation. As we change the speed of sound from 1 to 0 in the quintessence cold dark matter model with given state parameters, it is found that the inclusion of dark energy anisotropic stress makes the variation of magnitude of the ISW source uncertain due to the anticorrelation between the speed of sound and the ratio of dark energy density perturbation contrast to dark matter density perturbation contrast in the ISW-source term. Thus, the magnitude of the ISW-source term is governed by the competition between the alterant multiple of (1+3/2xc-circumflex s 2 ) and that of δ de /δ m with the variation of c-circumflex s 2 .

An optimisation approach for capacity planning: modelling insights and empirical findings from a tactical perspective

Directory of Open Access Journals (Sweden)

Andréa Nunes Carvalho

2017-09-01

Full Text Available Abstract The academic literature presents a research-practice gap on the application of decision support tools to address tactical planning problems in real-world organisations. This paper addresses this gap and extends a previous action research relative to an optimisation model applied for tactical capacity planning in an engineer-to-order industrial setting. The issues discussed herein raise new insights to better understand the practical results that can be achieved through the proposed model. The topics presented include the modelling of objectives, the representation of the production process and the costing approach, as well as findings regarding managerial decisions and the scope of action considered. These insights may inspire ideas to academics and practitioners when developing tools for capacity planning problems in similar contexts.

Modelling the exposure of wildlife to radiation: key findings and activities of IAEA working groups

Energy Technology Data Exchange (ETDEWEB)

Beresford, Nicholas A. [NERC Centre for Ecology and Hydrology, Lancaster Environment Center, Library Av., Bailrigg, Lancaster, LA1 4AP (United Kingdom); School of Environment and Life Sciences, University of Salford, Manchester, M4 4WT (United Kingdom); Vives i Batlle, Jordi; Vandenhove, Hildegarde [Belgian Nuclear Research Centre, Belgian Nuclear Research Centre, Boeretang 200, 2400 Mol (Belgium); Beaugelin-Seiller, Karine [Institut de Radioprotection et de Surete Nucleaire (IRSN), PRP-ENV, SERIS, LM2E, Cadarache (France); Johansen, Mathew P. [ANSTO Australian Nuclear Science and Technology Organisation, New Illawarra Rd, Menai, NSW (Australia); Goulet, Richard [Canadian Nuclear Safety Commission, Environmental Risk Assessment Division, 280 Slater, Ottawa, K1A0H3 (Canada); Wood, Michael D. [School of Environment and Life Sciences, University of Salford, Manchester, M4 4WT (United Kingdom); Ruedig, Elizabeth [Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins (United States); Stark, Karolina; Bradshaw, Clare [Department of Ecology, Environment and Plant Sciences, Stockholm University, SE-10691 (Sweden); Andersson, Pal [Swedish Radiation Safety Authority, SE-171 16, Stockholm (Sweden); Copplestone, David [Biological and Environmental Sciences, University of Stirling, Stirling, FK9 4LA (United Kingdom); Yankovich, Tamara L.; Fesenko, Sergey [International Atomic Energy Agency, Vienna International Centre, 1400, Vienna (Austria)

2014-07-01

In total, participants from 14 countries, representing 19 organisations, actively participated in the model application/inter-comparison activities of the IAEA's EMRAS II programme Biota Modelling Group. A range of models/approaches were used by participants (e.g. the ERICA Tool, RESRAD-BIOTA, the ICRP Framework). The agreed objectives of the group were: 'To improve Member State's capabilities for protection of the environment by comparing and validating models being used, or developed, for biota dose assessment (that may be used) as part of the regulatory process of licensing and compliance monitoring of authorised releases of radionuclides.' The activities of the group, the findings of which will be described, included: - An assessment of the predicted unweighted absorbed dose rates for 74 radionuclides estimated by 10 approaches for five of the ICRPs Reference Animal and Plant geometries assuming 1 Bq per unit organism or media. - Modelling the effect of heterogeneous distributions of radionuclides in sediment profiles on the estimated exposure of organisms. - Model prediction - field data comparisons for freshwater ecosystems in a uranium mining area and a number of wetland environments. - An evaluation of the application of available models to a scenario considering radioactive waste buried in shallow trenches. - Estimating the contribution of {sup 235}U to dose rates in freshwater environments. - Evaluation of the factors contributing to variation in modelling results. The work of the group continues within the framework of the IAEA's MODARIA programme, which was initiated in 2012. The work plan of the MODARIA working group has largely been defined by the findings of the previous EMRAS programme. On-going activities of the working group, which will be described, include the development of a database of dynamic parameters for wildlife dose assessment and exercises involving modelling the exposure of organisms in the marine coastal

Review for 'Nattoh' model and experimental findings during cold fusion

International Nuclear Information System (INIS)

Matsumoto, Takaaki

1993-01-01

A review is described for the Nattoh model that provides the framework of the mechanisms of cold fusion. The model classifies the reactions into two categories: fundamental and associated reactions. The former involves the new 'hydrogen-catalyzed' fusion reaction and the chain-reactions of hydrogens. And extremely exciting physics are involved in the latter. Furthermore experimental findings are described. (author)

Key Characteristics of Combined Accident including TLOFW accident for PSA Modeling

Energy Technology Data Exchange (ETDEWEB)

Kim, Bo Gyung; Kang, Hyun Gook [KAIST, Daejeon (Korea, Republic of); Yoon, Ho Joon [Khalifa University of Science, Technology and Research, Abu Dhabi (United Arab Emirates)

2015-05-15

The conventional PSA techniques cannot adequately evaluate all events. The conventional PSA models usually focus on single internal events such as DBAs, the external hazards such as fire, seismic. However, the Fukushima accident of Japan in 2011 reveals that very rare event is necessary to be considered in the PSA model to prevent the radioactive release to environment caused by poor treatment based on lack of the information, and to improve the emergency operation procedure. Especially, the results from PSA can be used to decision making for regulators. Moreover, designers can consider the weakness of plant safety based on the quantified results and understand accident sequence based on human actions and system availability. This study is for PSA modeling of combined accidents including total loss of feedwater (TLOFW) accident. The TLOFW accident is a representative accident involving the failure of cooling through secondary side. If the amount of heat transfer is not enough due to the failure of secondary side, the heat will be accumulated to the primary side by continuous core decay heat. Transients with loss of feedwater include total loss of feedwater accident, loss of condenser vacuum accident, and closure of all MSIVs. When residual heat removal by the secondary side is terminated, the safety injection into the RCS with direct primary depressurization would provide alternative heat removal. This operation is called feed and bleed (F and B) operation. Combined accidents including TLOFW accident are very rare event and partially considered in conventional PSA model. Since the necessity of F and B operation is related to plant conditions, the PSA modeling for combined accidents including TLOFW accident is necessary to identify the design and operational vulnerabilities.The PSA is significant to assess the risk of NPPs, and to identify the design and operational vulnerabilities. Even though the combined accident is very rare event, the consequence of combined

Health Promotion Behavior of Chinese International Students in Korea Including Acculturation Factors: A Structural Equation Model.

Science.gov (United States)

Kim, Sun Jung; Yoo, Il Young

2016-03-01

The purpose of this study was to explain the health promotion behavior of Chinese international students in Korea using a structural equation model including acculturation factors. A survey using self-administered questionnaires was employed. Data were collected from 272 Chinese students who have resided in Korea for longer than 6 months. The data were analyzed using structural equation modeling. The p value of final model is .31. The fitness parameters of the final model such as goodness of fit index, adjusted goodness of fit index, normed fit index, non-normed fit index, and comparative fit index were more than .95. Root mean square of residual and root mean square error of approximation also met the criteria. Self-esteem, perceived health status, acculturative stress and acculturation level had direct effects on health promotion behavior of the participants and the model explained 30.0% of variance. The Chinese students in Korea with higher self-esteem, perceived health status, acculturation level, and lower acculturative stress reported higher health promotion behavior. The findings can be applied to develop health promotion strategies for this population. Copyright © 2016. Published by Elsevier B.V.

General method to find the attractors of discrete dynamic models of biological systems

Science.gov (United States)

Gan, Xiao; Albert, Réka

2018-04-01

Analyzing the long-term behaviors (attractors) of dynamic models of biological networks can provide valuable insight. We propose a general method that can find the attractors of multilevel discrete dynamical systems by extending a method that finds the attractors of a Boolean network model. The previous method is based on finding stable motifs, subgraphs whose nodes' states can stabilize on their own. We extend the framework from binary states to any finite discrete levels by creating a virtual node for each level of a multilevel node, and describing each virtual node with a quasi-Boolean function. We then create an expanded representation of the multilevel network, find multilevel stable motifs and oscillating motifs, and identify attractors by successive network reduction. In this way, we find both fixed point attractors and complex attractors. We implemented an algorithm, which we test and validate on representative synthetic networks and on published multilevel models of biological networks. Despite its primary motivation to analyze biological networks, our motif-based method is general and can be applied to any finite discrete dynamical system.

General method to find the attractors of discrete dynamic models of biological systems.

Science.gov (United States)

Gan, Xiao; Albert, Réka

2018-04-01

Analyzing the long-term behaviors (attractors) of dynamic models of biological networks can provide valuable insight. We propose a general method that can find the attractors of multilevel discrete dynamical systems by extending a method that finds the attractors of a Boolean network model. The previous method is based on finding stable motifs, subgraphs whose nodes' states can stabilize on their own. We extend the framework from binary states to any finite discrete levels by creating a virtual node for each level of a multilevel node, and describing each virtual node with a quasi-Boolean function. We then create an expanded representation of the multilevel network, find multilevel stable motifs and oscillating motifs, and identify attractors by successive network reduction. In this way, we find both fixed point attractors and complex attractors. We implemented an algorithm, which we test and validate on representative synthetic networks and on published multilevel models of biological networks. Despite its primary motivation to analyze biological networks, our motif-based method is general and can be applied to any finite discrete dynamical system.

The Influence Of Learning Model Guided Findings Of Student Learning Outcomes

Directory of Open Access Journals (Sweden)

A. SaefulBahri

2015-03-01

Full Text Available Abstract This study examines the influence of the learning model guided findings on student learning outcomes in subjects PAI eighth grade students of SMP Plus al Masoem. The research method used in this study is a quantitative method in the form of quasi-experiment Quasi-Experimental Design. The findings of the study are expected to demonstrate 1 the difference significant increase in learning outcomes between the experimental class using guided discovery method that uses the control class discussion of learning models 2 Constraints in the method of guided discovery activities and the limited ability of educators in the experimental class in implements the method of guided discovery and constraints faced by students while digging the information they need so we need special strategies to motivate students in the experimental class in order for them creatively find the right way to gather information that supports learning PAI.

RELAP5-3D Code Includes ATHENA Features and Models

International Nuclear Information System (INIS)

Riemke, Richard A.; Davis, Cliff B.; Schultz, Richard R.

2006-01-01

Version 2.3 of the RELAP5-3D computer program includes all features and models previously available only in the ATHENA version of the code. These include the addition of new working fluids (i.e., ammonia, blood, carbon dioxide, glycerol, helium, hydrogen, lead-bismuth, lithium, lithium-lead, nitrogen, potassium, sodium, and sodium-potassium) and a magnetohydrodynamic model that expands the capability of the code to model many more thermal-hydraulic systems. In addition to the new working fluids along with the standard working fluid water, one or more noncondensable gases (e.g., air, argon, carbon dioxide, carbon monoxide, helium, hydrogen, krypton, nitrogen, oxygen, SF 6 , xenon) can be specified as part of the vapor/gas phase of the working fluid. These noncondensable gases were in previous versions of RELAP5-3D. Recently four molten salts have been added as working fluids to RELAP5-3D Version 2.4, which has had limited release. These molten salts will be in RELAP5-3D Version 2.5, which will have a general release like RELAP5-3D Version 2.3. Applications that use these new features and models are discussed in this paper. (authors)

Collisional-radiative model including recombination processes for W27+ ion★

Science.gov (United States)

Murakami, Izumi; Sasaki, Akira; Kato, Daiji; Koike, Fumihiro

2017-10-01

We have constructed a collisional-radiative (CR) model for W27+ ions including 226 configurations with n ≤ 9 and ł ≤ 5 for spectroscopic diagnostics. We newly include recombination processes in the model and this is the first result of extreme ultraviolet spectrum calculated for recombining plasma component. Calculated spectra in 40-70 Å range in ionizing and recombining plasma components show similar 3 strong lines and 1 line weak in recombining plasma component at 45-50 Å and many weak lines at 50-65 Å for both components. Recombination processes do not contribute much to the spectrum at around 60 Å for W27+ ion. Dielectronic satellite lines are also minor contribution to the spectrum of recombining plasma component. Dielectronic recombination (DR) rate coefficient from W28+ to W27+ ions is also calculated with the same atomic data in the CR model. We found that larger set of energy levels including many autoionizing states gave larger DR rate coefficients but our rate agree within factor 6 with other works at electron temperature around 1 keV in which W27+ and W28+ ions are usually observed in plasmas. Contribution to the Topical Issue "Atomic and Molecular Data and their Applications", edited by Gordon W.F. Drake, Jung-Sik Yoon, Daiji Kato, and Grzegorz Karwasz.

Gene finding with a hidden Markov model of genome structure and evolution

DEFF Research Database (Denmark)

Pedersen, Jakob Skou; Hein, Jotun

2003-01-01

the model are linear in alignment length and genome number. The model is applied to the problem of gene finding. The benefit of modelling sequence evolution is demonstrated both in a range of simulations and on a set of orthologous human/mouse gene pairs. AVAILABILITY: Free availability over the Internet...

Tuberculosis active case finding in Cambodia: a pragmatic, cost-effectiveness comparison of three implementation models.

Science.gov (United States)

James, Richard; Khim, Keovathanak; Boudarene, Lydia; Yoong, Joanne; Phalla, Chea; Saint, Saly; Koeut, Pichenda; Mao, Tan Eang; Coker, Richard; Khan, Mishal Sameer

2017-08-22

Globally, almost 40% of tuberculosis (TB) patients remain undiagnosed, and those that are diagnosed often experience prolonged delays before initiating correct treatment, leading to ongoing transmission. While there is a push for active case finding (ACF) to improve early detection and treatment of TB, there is extremely limited evidence about the relative cost-effectiveness of different ACF implementation models. Cambodia presents a unique opportunity for addressing this gap in evidence as ACF has been implemented using different models, but no comparisons have been conducted. The objective of our study is to contribute to knowledge and methodology on comparing cost-effectiveness of alternative ACF implementation models from the health service perspective, using programmatic data, in order to inform national policy and practice. We retrospectively compared three distinct ACF implementation models - door to door symptom screening in urban slums, checking contacts of TB patients, and door to door symptom screening focusing on rural populations aged above 55 - in terms of the number of new bacteriologically-positive pulmonary TB cases diagnosed and the cost of implementation assuming activities are conducted by the national TB program of Cambodia. We calculated the cost per additional case detected using the alternative ACF models. Our analysis, which is the first of its kind for TB, revealed that the ACF model based on door to door screening in poor urban areas of Phnom Penh was the most cost-effective (249 USD per case detected, 737 cases diagnosed), followed by the model based on testing contacts of TB patients (308 USD per case detected, 807 cases diagnosed), and symptomatic screening of older rural populations (316 USD per case detected, 397 cases diagnosed). Our study provides new evidence on the relative effectiveness and economics of three implementation models for enhanced TB case finding, in line with calls for data from 'routine conditions' to be included

Finding viable models in SUSY parameter spaces with signal specific discovery potential

Science.gov (United States)

Burgess, Thomas; Lindroos, Jan Øye; Lipniacka, Anna; Sandaker, Heidi

2013-08-01

Recent results from ATLAS giving a Higgs mass of 125.5 GeV, further constrain already highly constrained supersymmetric models such as pMSSM or CMSSM/mSUGRA. As a consequence, finding potentially discoverable and non-excluded regions of model parameter space is becoming increasingly difficult. Several groups have invested large effort in studying the consequences of Higgs mass bounds, upper limits on rare B-meson decays, and limits on relic dark matter density on constrained models, aiming at predicting superpartner masses, and establishing likelihood of SUSY models compared to that of the Standard Model vis-á-vis experimental data. In this paper a framework for efficient search for discoverable, non-excluded regions of different SUSY spaces giving specific experimental signature of interest is presented. The method employs an improved Markov Chain Monte Carlo (MCMC) scheme exploiting an iteratively updated likelihood function to guide search for viable models. Existing experimental and theoretical bounds as well as the LHC discovery potential are taken into account. This includes recent bounds on relic dark matter density, the Higgs sector and rare B-mesons decays. A clustering algorithm is applied to classify selected models according to expected phenomenology enabling automated choice of experimental benchmarks and regions to be used for optimizing searches. The aim is to provide experimentalist with a viable tool helping to target experimental signatures to search for, once a class of models of interest is established. As an example a search for viable CMSSM models with τ-lepton signatures observable with the 2012 LHC data set is presented. In the search 105209 unique models were probed. From these, ten reference benchmark points covering different ranges of phenomenological observables at the LHC were selected.

Parallel shooting methods for finding steady state solutions to engine simulation models

DEFF Research Database (Denmark)

Andersen, Stig Kildegård; Thomsen, Per Grove; Carlsen, Henrik

2007-01-01

Parallel single- and multiple shooting methods were tested for finding periodic steady state solutions to a Stirling engine model. The model was used to illustrate features of the methods and possibilities for optimisations. Performance was measured using simulation of an experimental data set...

Extending Primitive Spatial Data Models to Include Semantics

Science.gov (United States)

Reitsma, F.; Batcheller, J.

2009-04-01

Our traditional geospatial data model involves associating some measurable quality, such as temperature, or observable feature, such as a tree, with a point or region in space and time. When capturing data we implicitly subscribe to some kind of conceptualisation. If we can make this explicit in an ontology and associate it with the captured data, we can leverage formal semantics to reason with the concepts represented in our spatial data sets. To do so, we extend our fundamental representation of geospatial data in a data model by including a URI in our basic data model that links it to our ontology defining our conceptualisation, We thus extend Goodchild et al's geo-atom [1] with the addition of a URI: (x, Z, z(x), URI) . This provides us with pixel or feature level knowledge and the ability to create layers of data from a set of pixels or features that might be drawn from a database based on their semantics. Using open source tools, we present a prototype that involves simple reasoning as a proof of concept. References [1] M.F. Goodchild, M. Yuan, and T.J. Cova. Towards a general theory of geographic representation in gis. International Journal of Geographical Information Science, 21(3):239-260, 2007.

Using a Gradient Vector to Find Multiple Periodic Oscillations in Suspension Bridge Models

Science.gov (United States)

Humphreys, L. D.; McKenna, P. J.

2005-01-01

This paper describes how the method of steepest descent can be used to find periodic solutions of differential equations. Applications to two suspension bridge models are discussed, and the method is used to find non-obvious large-amplitude solutions.

Conceptualizing a Dynamic Fall Risk Model Including Intrinsic Risks and Exposures.

Science.gov (United States)

Klenk, Jochen; Becker, Clemens; Palumbo, Pierpaolo; Schwickert, Lars; Rapp, Kilan; Helbostad, Jorunn L; Todd, Chris; Lord, Stephen R; Kerse, Ngaire

2017-11-01

Falls are a major cause of injury and disability in older people, leading to serious health and social consequences including fractures, poor quality of life, loss of independence, and institutionalization. To design and provide adequate prevention measures, accurate understanding and identification of person's individual fall risk is important. However, to date, the performance of fall risk models is weak compared with models estimating, for example, cardiovascular risk. This deficiency may result from 2 factors. First, current models consider risk factors to be stable for each person and not change over time, an assumption that does not reflect real-life experience. Second, current models do not consider the interplay of individual exposure including type of activity (eg, walking, undertaking transfers) and environmental risks (eg, lighting, floor conditions) in which activity is performed. Therefore, we posit a dynamic fall risk model consisting of intrinsic risk factors that vary over time and exposure (activity in context). eHealth sensor technology (eg, smartphones) begins to enable the continuous measurement of both the above factors. We illustrate our model with examples of real-world falls from the FARSEEING database. This dynamic framework for fall risk adds important aspects that may improve understanding of fall mechanisms, fall risk models, and the development of fall prevention interventions. Copyright © 2017 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

Mobile-Source GHG Modeling Institutions and Capacities in China:Findings Based on Structured Interviews and On-Line Surveys

Institute of Scientific and Technical Information of China (English)

Jiangping; ZHOU; Yin; WANG

2014-01-01

This paper provides an overview of practices of mobile-source greenhouse gas(GHG) modeling in China and related data sharing issues. It is based on structured phone interviews and two on-line surveys conducted in 2011 and finds that most cities have transportation-land use models but that few have mobile-source GHG models. A group of entities housed in the government have the strongest GHG modeling capacities and dominate the relevant consulting market. Data hoarding of public entities is the biggest barrier for entities without government ties to compete in the market. The reasons for data hoarding include government concerns over political implications of data release, a tradition of data hoarding, and a lack of confidence in reliability and accuracy of the data.

Grand unified models including extra Z bosons

International Nuclear Information System (INIS)

Li Tiezhong

1989-01-01

The grand unified theories (GUT) of the simple Lie groups including extra Z bosons are discussed. Under authors's hypothesis there are only SU 5+m SO 6+4n and E 6 groups. The general discussion of SU 5+m is given, then the SU 6 and SU 7 are considered. In SU 6 the 15+6 * +6 * fermion representations are used, which are not same as others in fermion content, Yukawa coupling and broken scales. A conception of clans of particles, which are not families, is suggested. These clans consist of extra Z bosons and the corresponding fermions of the scale. The all of fermions in the clans are down quarks except for the standard model which consists of Z bosons and 15 fermions, therefore, the spectrum of the hadrons which are composed of these down quarks are different from hadrons at present

Modeling of cylindrical surrounding gate MOSFETs including the fringing field effects

International Nuclear Information System (INIS)

Gupta, Santosh K.; Baishya, Srimanta

2013-01-01

A physically based analytical model for surface potential and threshold voltage including the fringing gate capacitances in cylindrical surround gate (CSG) MOSFETs has been developed. Based on this a subthreshold drain current model has also been derived. This model first computes the charge induced in the drain/source region due to the fringing capacitances and considers an effective charge distribution in the cylindrically extended source/drain region for the development of a simple and compact model. The fringing gate capacitances taken into account are outer fringe capacitance, inner fringe capacitance, overlap capacitance, and sidewall capacitance. The model has been verified with the data extracted from 3D TCAD simulations of CSG MOSFETs and was found to be working satisfactorily. (semiconductor devices)

A Mixed Method Research for Finding a Model of Administrative Decentralization

OpenAIRE

Tahereh Feizy; Alireza Moghali; Masuod Geramipoor; Reza Zare

2015-01-01

One of the critical issues of administrative decentralization in translating theory into practice is understanding its meaning. An important method to identify administrative decentralization is to address how it can be planned and implemented, and what are its implications, and how it would overcome challenges. The purpose of this study is finding a model for analyzing and evaluating administrative decentralization, so a mixed method research was used to explore and confirm the model of Admi...

A roller chain drive model including contact with guide-bars

DEFF Research Database (Denmark)

Pedersen, Sine Leergaard; Hansen, John Michael; Ambrósio, J. A. C.

2004-01-01

A model of a roller chain drive is developed and applied to the simulation and analysis of roller chain drives of large marine diesel engines. The model includes the impact with guide-bars that are the motion delimiter components on the chain strands between the sprockets. The main components...... and the sprocket centre, i.e. a constraint is added when such distance is less than the pitch radius. The unilateral kinematic constraint is removed when its associated constraint reaction force, applied on the roller, is in the direction of the root of the sprocket teeth. In order to improve the numerical...

A constitutive model for the forces of a magnetic bearing including eddy currents

Science.gov (United States)

Taylor, D. L.; Hebbale, K. V.

1993-01-01

A multiple magnet bearing can be developed from N individual electromagnets. The constitutive relationships for a single magnet in such a bearing is presented. Analytical expressions are developed for a magnet with poles arranged circumferencially. Maxwell's field equations are used so the model easily includes the effects of induced eddy currents due to the rotation of the journal. Eddy currents must be included in any dynamic model because they are the only speed dependent parameter and may lead to a critical speed for the bearing. The model is applicable to bearings using attraction or repulsion.

Including policy and management in socio-hydrology models: initial conceptualizations

Science.gov (United States)

Hermans, Leon; Korbee, Dorien

2017-04-01

Socio-hydrology studies the interactions in coupled human-water systems. So far, the use of dynamic models that capture the direct feedback between societal and hydrological systems has been dominant. What has not yet been included with any particular emphasis, is the policy or management layer, which is a central element in for instance integrated water resources management (IWRM) or adaptive delta management (ADM). Studying the direct interactions between human-water systems generates knowledges that eventually helps influence these interactions in ways that may ensure better outcomes - for society and for the health and sustainability of water systems. This influence sometimes occurs through spontaneous emergence, uncoordinated by societal agents - private sector, citizens, consumers, water users. However, the term 'management' in IWRM and ADM also implies an additional coordinated attempt through various public actors. This contribution is a call to include the policy and management dimension more prominently into the research focus of the socio-hydrology field, and offers first conceptual variables that should be considered in attempts to include this policy or management layer in socio-hydrology models. This is done by drawing on existing frameworks to study policy processes throughout both planning and implementation phases. These include frameworks such as the advocacy coalition framework, collective learning and policy arrangements, which all emphasis longer-term dynamics and feedbacks between actor coalitions in strategic planning and implementation processes. A case about longter-term dynamics in the management of the Haringvliet in the Netherlands is used to illustrate the paper.

A hydrodynamic model for granular material flows including segregation effects

Science.gov (United States)

Gilberg, Dominik; Klar, Axel; Steiner, Konrad

2017-06-01

The simulation of granular flows including segregation effects in large industrial processes using particle methods is accurate, but very time-consuming. To overcome the long computation times a macroscopic model is a natural choice. Therefore, we couple a mixture theory based segregation model to a hydrodynamic model of Navier-Stokes-type, describing the flow behavior of the granular material. The granular flow model is a hybrid model derived from kinetic theory and a soil mechanical approach to cover the regime of fast dilute flow, as well as slow dense flow, where the density of the granular material is close to the maximum packing density. Originally, the segregation model has been formulated by Thornton and Gray for idealized avalanches. It is modified and adapted to be in the preferred form for the coupling. In the final coupled model the segregation process depends on the local state of the granular system. On the other hand, the granular system changes as differently mixed regions of the granular material differ i.e. in the packing density. For the modeling process the focus lies on dry granular material flows of two particle types differing only in size but can be easily extended to arbitrary granular mixtures of different particle size and density. To solve the coupled system a finite volume approach is used. To test the model the rotational mixing of small and large particles in a tumbler is simulated.

Mathematical Model of Thyristor Inverter Including a Series-parallel Resonant Circuit

OpenAIRE

Miroslaw Luft; Elzbieta Szychta

2008-01-01

The article presents a mathematical model of thyristor inverter including a series-parallel resonant circuit with theaid of state variable method. Maple procedures are used to compute current and voltage waveforms in the inverter.

Exploring a model for finding meaning in the changing world of work (Part 2

Directory of Open Access Journals (Sweden)

Daniel H. Burger

2012-06-01

Research purpose: The purpose of this study is to explore further a model an earlier paper proposed for using employees’ experiences of meaning in work contexts to facilitate changes. Motivation for the study: The researchers could not find a comprehensive model in the literature for addressing employees’ experiences of meaning in, or at, work during organisational changes. A previous paper proposed such a model, but it addressed only one component fully. This article seeks to explore this model further to address this apparent gap in the literature. Research design, approach and method: The researchers used a literature review to conduct the study. The components of the model directed this review in order to find meaning at work. Main findings: The actions of organisations, which aim to create positive organisational contexts (through practices for improving meaning at work and transcendence and to frame changes using ‘Logo-OD’, can improve employees’ experiences of meaning during organisational changes. Practical/managerial implications: Understanding the relationship between meaning and organisational change, and applying the model this article presents, can contribute to the overall success of change initiatives. Contribution/value-add: This study’s primary contribution stems from the novel framework it presents for organisations to use the knowledge about how employees search for meaning to facilitate changes.

Mathematical model of thyristor inverter including a series-parallel resonant circuit

OpenAIRE

Luft, M.; Szychta, E.

2008-01-01

The article presents a mathematical model of thyristor inverter including a series-parallel resonant circuit with the aid of state variable method. Maple procedures are used to compute current and voltage waveforms in the inverter.

Accurate SHAPE-directed RNA secondary structure modeling, including pseudoknots.

Science.gov (United States)

Hajdin, Christine E; Bellaousov, Stanislav; Huggins, Wayne; Leonard, Christopher W; Mathews, David H; Weeks, Kevin M

2013-04-02

A pseudoknot forms in an RNA when nucleotides in a loop pair with a region outside the helices that close the loop. Pseudoknots occur relatively rarely in RNA but are highly overrepresented in functionally critical motifs in large catalytic RNAs, in riboswitches, and in regulatory elements of viruses. Pseudoknots are usually excluded from RNA structure prediction algorithms. When included, these pairings are difficult to model accurately, especially in large RNAs, because allowing this structure dramatically increases the number of possible incorrect folds and because it is difficult to search the fold space for an optimal structure. We have developed a concise secondary structure modeling approach that combines SHAPE (selective 2'-hydroxyl acylation analyzed by primer extension) experimental chemical probing information and a simple, but robust, energy model for the entropic cost of single pseudoknot formation. Structures are predicted with iterative refinement, using a dynamic programming algorithm. This melded experimental and thermodynamic energy function predicted the secondary structures and the pseudoknots for a set of 21 challenging RNAs of known structure ranging in size from 34 to 530 nt. On average, 93% of known base pairs were predicted, and all pseudoknots in well-folded RNAs were identified.

Progress Towards an LES Wall Model Including Unresolved Roughness

Science.gov (United States)

Craft, Kyle; Redman, Andrew; Aikens, Kurt

2015-11-01

Wall models used in large eddy simulations (LES) are often based on theories for hydraulically smooth walls. While this is reasonable for many applications, there are also many where the impact of surface roughness is important. A previously developed wall model has been used primarily for jet engine aeroacoustics. However, jet simulations have not accurately captured thick initial shear layers found in some experimental data. This may partly be due to nozzle wall roughness used in the experiments to promote turbulent boundary layers. As a result, the wall model is extended to include the effects of unresolved wall roughness through appropriate alterations to the log-law. The methodology is tested for incompressible flat plate boundary layers with different surface roughness. Correct trends are noted for the impact of surface roughness on the velocity profile. However, velocity deficit profiles and the Reynolds stresses do not collapse as well as expected. Possible reasons for the discrepancies as well as future work will be presented. This work used the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation grant number ACI-1053575. Computational resources on TACC Stampede were provided under XSEDE allocation ENG150001.

Kinetic models of gene expression including non-coding RNAs

Energy Technology Data Exchange (ETDEWEB)

Zhdanov, Vladimir P., E-mail: zhdanov@catalysis.r

2011-03-15

In cells, genes are transcribed into mRNAs, and the latter are translated into proteins. Due to the feedbacks between these processes, the kinetics of gene expression may be complex even in the simplest genetic networks. The corresponding models have already been reviewed in the literature. A new avenue in this field is related to the recognition that the conventional scenario of gene expression is fully applicable only to prokaryotes whose genomes consist of tightly packed protein-coding sequences. In eukaryotic cells, in contrast, such sequences are relatively rare, and the rest of the genome includes numerous transcript units representing non-coding RNAs (ncRNAs). During the past decade, it has become clear that such RNAs play a crucial role in gene expression and accordingly influence a multitude of cellular processes both in the normal state and during diseases. The numerous biological functions of ncRNAs are based primarily on their abilities to silence genes via pairing with a target mRNA and subsequently preventing its translation or facilitating degradation of the mRNA-ncRNA complex. Many other abilities of ncRNAs have been discovered as well. Our review is focused on the available kinetic models describing the mRNA, ncRNA and protein interplay. In particular, we systematically present the simplest models without kinetic feedbacks, models containing feedbacks and predicting bistability and oscillations in simple genetic networks, and models describing the effect of ncRNAs on complex genetic networks. Mathematically, the presentation is based primarily on temporal mean-field kinetic equations. The stochastic and spatio-temporal effects are also briefly discussed.

Mathematical Model of Thyristor Inverter Including a Series-parallel Resonant Circuit

Directory of Open Access Journals (Sweden)

Miroslaw Luft

2008-01-01

Full Text Available The article presents a mathematical model of thyristor inverter including a series-parallel resonant circuit with theaid of state variable method. Maple procedures are used to compute current and voltage waveforms in the inverter.

Including sugar cane in the agro-ecosystem model ORCHIDEE-STICS

Science.gov (United States)

Valade, A.; Vuichard, N.; Ciais, P.; Viovy, N.

2010-12-01

With 4 million ha currently grown for ethanol in Brazil only, approximately half the global bioethanol production in 2005 (Smeets 2008), and a devoted land area expected to expand globally in the years to come, sugar cane is at the heart of the biofuel debate. Indeed, ethanol made from biomass is currently the most widespread option for alternative transportation fuels. It was originally promoted as a carbon neutral energy resource that could bring energy independence to countries and local opportunities to farmers, until attention was drawn to its environmental and socio-economical drawbacks. It is still not clear to which extent it is a solution or a contributor to climate change mitigation. Dynamic Global Vegetation models can help address these issues and quantify the potential impacts of biofuels on ecosystems at scales ranging from on-site to global. The global agro-ecosystem model ORCHIDEE describes water, carbon and energy exchanges at the soil-atmosphere interface for a limited number of natural and agricultural vegetation types. In order to integrate agricultural management to the simulations and to capture more accurately the specificity of crops' phenology, ORCHIDEE has been coupled with the agronomical model STICS. The resulting crop-oriented vegetation model ORCHIDEE-STICS has been used so far to simulate temperate crops such as wheat, corn and soybean. As a generic ecosystem model, each grid cell can include several vegetation types with their own phenology and management practices, making it suitable to spatial simulations. Here, ORCHIDEE-STICS is altered to include sugar cane as a new agricultural Plant functional Type, implemented and parametrized using the STICS approach. An on-site calibration and validation is then performed based on biomass and flux chamber measurements in several sites in Australia and variables such as LAI, dry weight, heat fluxes and respiration are used to evaluate the ability of the model to simulate the specific

Design and modeling of an advanced marine machinery system including waste heat recovery and removal of sulphur oxides

DEFF Research Database (Denmark)

Frimann Nielsen, Rasmus; Haglind, Fredrik; Larsen, Ulrik

2014-01-01

the efficiency of machinery systems. The wet sulphuric acid process is an effective way of removing flue gas sulphur oxides from land-based coal-fired power plants. Moreover, organic Rankine cycles (ORC) are suitable for heat to power conversion for low temperature heat sources. This paper describes the design...... that an ORC placed after the conventional waste heat recovery system is able to extract the sulphuric acid from the exhaust gas, while at the same time increase the combined cycle thermal efficiency by 2.6%. The findings indicate that the technology has potential in marine applications regarding both energy...... and modeling of a highly efficient machinery system which includes the removal of exhaust gas sulphur oxides. The system consists of a two-stroke diesel engine, the wet sulphuric process for sulphur removal, a conventional steam Rankine cycle and an ORC. Results of numerical modeling efforts suggest...

Global atmospheric model for mercury including oxidation by bromine atoms

Directory of Open Access Journals (Sweden)

C. D. Holmes

2010-12-01

Full Text Available Global models of atmospheric mercury generally assume that gas-phase OH and ozone are the main oxidants converting Hg⁰ to Hg^II and thus driving mercury deposition to ecosystems. However, thermodynamic considerations argue against the importance of these reactions. We demonstrate here the viability of atomic bromine (Br as an alternative Hg⁰ oxidant. We conduct a global 3-D simulation with the GEOS-Chem model assuming gas-phase Br to be the sole Hg⁰ oxidant (Hg + Br model and compare to the previous version of the model with OH and ozone as the sole oxidants (Hg + OH/O₃ model. We specify global 3-D Br concentration fields based on our best understanding of tropospheric and stratospheric Br chemistry. In both the Hg + Br and Hg + OH/O₃ models, we add an aqueous photochemical reduction of Hg^II in cloud to impose a tropospheric lifetime for mercury of 6.5 months against deposition, as needed to reconcile observed total gaseous mercury (TGM concentrations with current estimates of anthropogenic emissions. This added reduction would not be necessary in the Hg + Br model if we adjusted the Br oxidation kinetics downward within their range of uncertainty. We find that the Hg + Br and Hg + OH/O₃ models are equally capable of reproducing the spatial distribution of TGM and its seasonal cycle at northern mid-latitudes. The Hg + Br model shows a steeper decline of TGM concentrations from the tropics to southern mid-latitudes. Only the Hg + Br model can reproduce the springtime depletion and summer rebound of TGM observed at polar sites; the snowpack component of GEOS-Chem suggests that 40% of Hg^II deposited to snow in the Arctic is transferred to the ocean and land reservoirs, amounting to a net deposition flux to the Arctic of 60 Mg a⁻¹. Summertime events of depleted Hg⁰ at Antarctic sites due to subsidence are much better simulated by

Clarifying the use of aggregated exposures in multilevel models: self-included vs. self-excluded measures.

Directory of Open Access Journals (Sweden)

Etsuji Suzuki

Full Text Available Multilevel analyses are ideally suited to assess the effects of ecological (higher level and individual (lower level exposure variables simultaneously. In applying such analyses to measures of ecologies in epidemiological studies, individual variables are usually aggregated into the higher level unit. Typically, the aggregated measure includes responses of every individual belonging to that group (i.e. it constitutes a self-included measure. More recently, researchers have developed an aggregate measure which excludes the response of the individual to whom the aggregate measure is linked (i.e. a self-excluded measure. In this study, we clarify the substantive and technical properties of these two measures when they are used as exposures in multilevel models.Although the differences between the two aggregated measures are mathematically subtle, distinguishing between them is important in terms of the specific scientific questions to be addressed. We then show how these measures can be used in two distinct types of multilevel models-self-included model and self-excluded model-and interpret the parameters in each model by imposing hypothetical interventions. The concept is tested on empirical data of workplace social capital and employees' systolic blood pressure.Researchers assume group-level interventions when using a self-included model, and individual-level interventions when using a self-excluded model. Analytical re-parameterizations of these two models highlight their differences in parameter interpretation. Cluster-mean centered self-included models enable researchers to decompose the collective effect into its within- and between-group components. The benefit of cluster-mean centering procedure is further discussed in terms of hypothetical interventions.When investigating the potential roles of aggregated variables, researchers should carefully explore which type of model-self-included or self-excluded-is suitable for a given situation

Simple suggestions for including vertical physics in oil spill models

International Nuclear Information System (INIS)

D'Asaro, Eric; University of Washington, Seatle, WA

2001-01-01

Current models of oil spills include no vertical physics. They neglect the effect of vertical water motions on the transport and concentration of floating oil. Some simple ways to introduce vertical physics are suggested here. The major suggestion is to routinely measure the density stratification of the upper ocean during oil spills in order to develop a database on the effect of stratification. (Author)

Find-rate methodology and resource base estimates of the Hydrocarbon Supply Model (1990 update). Topical report

International Nuclear Information System (INIS)

Woods, T.

1991-02-01

The Hydrocarbon Supply Model is used to develop long-term trends in Lower-48 gas production and costs. The model utilizes historical find-rate patterns to predict the discovery rate and size distribution of future oil and gas field discoveries. The report documents the methodologies used to quantify historical oil and gas field find-rates and to project those discovery patterns for future drilling. It also explains the theoretical foundations for the find-rate approach. The new field and reserve growth resource base is documented and compared to other published estimates. The report has six sections. Section 1 provides background information and an overview of the model. Sections 2, 3, and 4 describe the theoretical foundations of the model, the databases, and specific techniques used. Section 5 presents the new field resource base by region and depth. Section 6 documents the reserve growth model components

Hydromechanical modeling of clay rock including fracture damage

Science.gov (United States)

Asahina, D.; Houseworth, J. E.; Birkholzer, J. T.

2012-12-01

Argillaceous rock typically acts as a flow barrier, but under certain conditions significant and potentially conductive fractures may be present. Fracture formation is well-known to occur in the vicinity of underground excavations in a region known as the excavation disturbed zone. Such problems are of particular importance for low-permeability, mechanically weak rock such as clays and shales because fractures can be relatively transient as a result of fracture self-sealing processes. Perhaps not as well appreciated is the fact that natural fractures can form in argillaceous rock as a result of hydraulic overpressure caused by phenomena such as disequlibrium compaction, changes in tectonic stress, and mineral dehydration. Overpressure conditions can cause hydraulic fracturing if the fluid pressure leads to tensile effective stresses that exceed the tensile strength of the material. Quantitative modeling of this type of process requires coupling between hydrogeologic processes and geomechanical processes including fracture initiation and propagation. Here we present a computational method for three-dimensional, hydromechanical coupled processes including fracture damage. Fractures are represented as discrete features in a fracture network that interact with a porous rock matrix. Fracture configurations are mapped onto an unstructured, three-dimensonal, Voronoi grid, which is based on a random set of spatial points. Discrete fracture networks (DFN) are represented by the connections of the edges of a Voronoi cells. This methodology has the advantage that fractures can be more easily introduced in response to coupled hydro-mechanical processes and generally eliminates several potential issues associated with the geometry of DFN and numerical gridding. A geomechanical and fracture-damage model is developed here using the Rigid-Body-Spring-Network (RBSN) numerical method. The hydrogelogic and geomechanical models share the same geometrical information from a 3D Voronoi

Exploring a model for finding meaning in the changing world of work (Part 2

Directory of Open Access Journals (Sweden)

Daniel H. Burger

2012-01-01

Full Text Available Orientation: This article explores the role that meaning, as logotherapy conceptualises it, can play to facilitate organisational changes.Research purpose: The purpose of this study is to explore further a model an earlier paper proposed for using employees’ experiences of meaning in work contexts to facilitate changes.Motivation for the study: The researchers could not find a comprehensive model in the literature for addressing employees’ experiences of meaning in, or at, work during organisational changes. A previous paper proposed such a model, but it addressed only one component fully. This article seeks to explore this model further to address this apparent gap in the literature.Research design, approach and method: The researchers used a literature review to conduct the study. The components of the model directed this review in order to find meaning at work.Main findings: The actions of organisations, which aim to create positive organisational contexts (through practices for improving meaning at work and transcendence and to frame changes using ‘Logo-OD’, can improve employees’ experiences of meaning during organisational changes.Practical/managerial implications: Understanding the relationship between meaning and organisational change, and applying the model this article presents, can contribute to the overall success of change initiatives.Contribution/value-add: This study’s primary contribution stems from the novel framework it presents for organisations to use the knowledge about how employees search for meaning to facilitate changes.

Direct-phase-variable model of a synchronous reluctance motor including all slot and winding harmonics

International Nuclear Information System (INIS)

Obe, Emeka S.; Binder, A.

2011-01-01

A detailed model in direct-phase variables of a synchronous reluctance motor operating at mains voltage and frequency is presented. The model includes the stator and rotor slot openings, the actual winding layout and the reluctance rotor geometry. Hence, all mmf and permeance harmonics are taken into account. It is seen that non-negligible harmonics introduced by slots are present in the inductances computed by the winding function procedure. These harmonics are usually ignored in d-q models. The machine performance is simulated in the stator reference frame to depict the difference between this new direct-phase model including all harmonics and the conventional rotor reference frame d-q model. Saturation is included by using a polynomial fitting the variation of d-axis inductance with stator current obtained by finite-element software FEMAG DC (registered) . The detailed phase-variable model can yield torque pulsations comparable to those obtained from finite elements while the d-q model cannot.

Emission-line diagnostics of nearby H II regions including interacting binary populations

Science.gov (United States)

Xiao, Lin; Stanway, Elizabeth R.; Eldridge, J. J.

2018-06-01

We present numerical models of the nebular emission from H II regions around young stellar populations over a range of compositions and ages. The synthetic stellar populations include both single stars and interacting binary stars. We compare these models to the observed emission lines of 254 H II regions of 13 nearby spiral galaxies and 21 dwarf galaxies drawn from archival data. The models are created using the combination of the BPASS (Binary Population and Spectral Synthesis) code with the photoionization code CLOUDY to study the differences caused by the inclusion of interacting binary stars in the stellar population. We obtain agreement with the observed emission line ratios from the nearby star-forming regions and discuss the effect of binary-star evolution pathways on the nebular ionization of H II regions. We find that at population ages above 10 Myr, single-star models rapidly decrease in flux and ionization strength, while binary-star models still produce strong flux and high [O III]/H β ratios. Our models can reproduce the metallicity of H II regions from spiral galaxies, but we find higher metallicities than previously estimated for the H II regions from dwarf galaxies. Comparing the equivalent width of H β emission between models and observations, we find that accounting for ionizing photon leakage can affect age estimates for H II regions. When it is included, the typical age derived for H II regions is 5 Myr from single-star models, and up to 10 Myr with binary-star models. This is due to the existence of binary-star evolution pathways, which produce more hot Wolf-Rayet and helium stars at older ages. For future reference, we calculate new BPASS binary maximal starburst lines as a function of metallicity, and for the total model population, and present these in Appendix A.

Cooling as a method of finding topological dislocations in lattice models

International Nuclear Information System (INIS)

Gomberoff, K.

1989-01-01

It is well known that the O(3) two-dimensional model has configurations with topological charge Q=1 and action S/sub min/=6.69. Since the exponent characterizing the renormalization-group behavior of this model is 4π such configurations invalidate the standard scaling behavior of the topological susceptibility. The analog exponent for the four-dimensional lattice SU(2) gauge model is 10.77. If there would exist configurations with Q=1 and S<10.77 in this model, they would invalidate the standard scaling behavior of its topological susceptibility. Kremer et al. have calculated the action of different configurations during cooling runs. They report that they do not find any configuration with S<12.7 and Q=1. I show that in the O(3) two-dimensional model cooling runs fail to uncover the well-known configurations with S<8. We conclude that the cooling method is not effective in uncovering the smallest action configurations in the Q=1 sector

Practical Findings from Applying the PSD Model for Evaluating Software Design Specifications

Science.gov (United States)

Räisänen, Teppo; Lehto, Tuomas; Oinas-Kukkonen, Harri

This paper presents practical findings from applying the PSD model to evaluating the support for persuasive features in software design specifications for a mobile Internet device. On the one hand, our experiences suggest that the PSD model fits relatively well for evaluating design specifications. On the other hand, the model would benefit from more specific heuristics for evaluating each technique to avoid unnecessary subjectivity. Better distinction between the design principles in the social support category would also make the model easier to use. Practitioners who have no theoretical background can apply the PSD model to increase the persuasiveness of the systems they design. The greatest benefit of the PSD model for researchers designing new systems may be achieved when it is applied together with a sound theory, such as the Elaboration Likelihood Model. Using the ELM together with the PSD model, one may increase the chances for attitude change.

Integrated model of port oil piping transportation system safety including operating environment threats

Directory of Open Access Journals (Sweden)

Kołowrocki Krzysztof

2017-06-01

Full Text Available The paper presents an integrated general model of complex technical system, linking its multistate safety model and the model of its operation process including operating environment threats and considering variable at different operation states its safety structures and its components safety parameters. Under the assumption that the system has exponential safety function, the safety characteristics of the port oil piping transportation system are determined.

Integrated model of port oil piping transportation system safety including operating environment threats

OpenAIRE

Kołowrocki, Krzysztof; Kuligowska, Ewa; Soszyńska-Budny, Joanna

2017-01-01

The paper presents an integrated general model of complex technical system, linking its multistate safety model and the model of its operation process including operating environment threats and considering variable at different operation states its safety structures and its components safety parameters. Under the assumption that the system has exponential safety function, the safety characteristics of the port oil piping transportation system are determined.

Enhanced UWB Radio Channel Model for Short-Range Communication Scenarios Including User Dynamics

DEFF Research Database (Denmark)

Kovacs, Istvan Zsolt; Nguyen, Tuan Hung; Eggers, Patrick Claus F.

2005-01-01

channel model represents an enhancement of the existing IEEE 802.15.3a/4a PAN channel model, where antenna and user-proximity effects are not included. Our investigations showed that significant variations of the received wideband power and time-delay signal clustering are possible due the human body...

Aggregated Demand Modelling Including Distributed Generation, Storage and Demand Response

OpenAIRE

Marzooghi, Hesamoddin; Hill, David J.; Verbic, Gregor

2014-01-01

It is anticipated that penetration of renewable energy sources (RESs) in power systems will increase further in the next decades mainly due to environmental issues. In the long term of several decades, which we refer to in terms of the future grid (FG), balancing between supply and demand will become dependent on demand actions including demand response (DR) and energy storage. So far, FG feasibility studies have not considered these new demand-side developments for modelling future demand. I...

Constraining the Magmatic System at Mount St. Helens (2004-2008) Using Bayesian Inversion With Physics-Based Models Including Gas Escape and Crystallization

International Nuclear Information System (INIS)

Wong, Ying-Qi; Segall, Paul; Bradley, Andrew; Anderson, Kyle

2017-01-01

Physics-based models of volcanic eruptions track conduit processes as functions of depth and time. When used in inversions, these models permit integration of diverse geological and geophysical data sets to constrain important parameters of magmatic systems. We develop a 1-D steady state conduit model for effusive eruptions including equilibrium crystallization and gas transport through the conduit and compare with the quasi-steady dome growth phase of Mount St. Helens in 2005. Viscosity increase resulting from pressure-dependent crystallization leads to a natural transition from viscous flow to frictional sliding on the conduit margin. Erupted mass flux depends strongly on wall rock and magma permeabilities due to their impact on magma density. Including both lateral and vertical gas transport reveals competing effects that produce nonmonotonic behavior in the mass flux when increasing magma permeability. Using this physics-based model in a Bayesian inversion, we link data sets from Mount St. Helens such as extrusion flux and earthquake depths with petrological data to estimate unknown model parameters, including magma chamber pressure and water content, magma permeability constants, conduit radius, and friction along the conduit walls. Even with this relatively simple model and limited data, we obtain improved constraints on important model parameters. We find that the magma chamber had low (<5 wt %) total volatiles and that the magma permeability scale is well constrained at ~10 –11.4 m 2 to reproduce observed dome rock porosities. Here, compared with previous results, higher magma overpressure and lower wall friction are required to compensate for increased viscous resistance while keeping extrusion rate at the observed value.

S5-4: Formal Modeling of Affordance in Human-Included Systems

Directory of Open Access Journals (Sweden)

Namhun Kim

2012-10-01

Full Text Available In spite of it being necessary for humans to consider modeling, analysis, and control of human-included systems, it has been considered a challenging problem because of the critical role of humans in complex systems and of humans' capability of executing unanticipated actions–both beneficial and detrimental ones. Thus, to provide systematic approaches to modeling human actions as a part of system behaviors, a formal modeling framework for human-involved systems in which humans play a controlling role based on their perceptual information is presented. The theory of affordance provides definitions of human actions and their associated properties; Finite State Automata (FSA based modeling is capable of mapping nondeterministic humans into computable components in the system representation. In this talk, we investigate the role of perception in human actions in the system operation and examine the representation of perceptual elements in affordance-based modeling formalism. The proposed framework is expected to capture the natural ways in which humans participate in the system as part of its operation. A human-machine cooperative manufacturing system control example and a human agent simulation example will be introduced for the illustrative purposes at the end of the presentation.

Modeling of the Direct Current Generator Including the Magnetic Saturation and Temperature Effects

Directory of Open Access Journals (Sweden)

Alfonso J. Mercado-Samur

2013-11-01

Full Text Available In this paper the inclusion of temperature effect on the field resistance on the direct current generator model DC1A, which is valid to stability studies is proposed. First, the linear generator model is presented, after the effect of magnetic saturation and the change in the resistance value due to temperature produced by the field current are included. The comparison of experimental results and model simulations to validate the model is used. A direct current generator model which is a better representation of the generator is obtained. Visual comparison between simulations and experimental results shows the success of the proposed model, because it presents the lowest error of the compared models. The accuracy of the proposed model is observed via Modified Normalized Sum of Squared Errors index equal to 3.8979%.

BioModels: expanding horizons to include more modelling approaches and formats.

Science.gov (United States)

Glont, Mihai; Nguyen, Tung V N; Graesslin, Martin; Hälke, Robert; Ali, Raza; Schramm, Jochen; Wimalaratne, Sarala M; Kothamachu, Varun B; Rodriguez, Nicolas; Swat, Maciej J; Eils, Jurgen; Eils, Roland; Laibe, Camille; Malik-Sheriff, Rahuman S; Chelliah, Vijayalakshmi; Le Novère, Nicolas; Hermjakob, Henning

2018-01-04

BioModels serves as a central repository of mathematical models representing biological processes. It offers a platform to make mathematical models easily shareable across the systems modelling community, thereby supporting model reuse. To facilitate hosting a broader range of model formats derived from diverse modelling approaches and tools, a new infrastructure for BioModels has been developed that is available at http://www.ebi.ac.uk/biomodels. This new system allows submitting and sharing of a wide range of models with improved support for formats other than SBML. It also offers a version-control backed environment in which authors and curators can work collaboratively to curate models. This article summarises the features available in the current system and discusses the potential benefit they offer to the users over the previous system. In summary, the new portal broadens the scope of models accepted in BioModels and supports collaborative model curation which is crucial for model reproducibility and sharing. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

A thermal conductivity model for nanofluids including effect of the temperature-dependent interfacial layer

International Nuclear Information System (INIS)

Sitprasert, Chatcharin; Dechaumphai, Pramote; Juntasaro, Varangrat

2009-01-01

The interfacial layer of nanoparticles has been recently shown to have an effect on the thermal conductivity of nanofluids. There is, however, still no thermal conductivity model that includes the effects of temperature and nanoparticle size variations on the thickness and consequently on the thermal conductivity of the interfacial layer. In the present work, the stationary model developed by Leong et al. (J Nanopart Res 8:245-254, 2006) is initially modified to include the thermal dispersion effect due to the Brownian motion of nanoparticles. This model is called the 'Leong et al.'s dynamic model'. However, the Leong et al.'s dynamic model over-predicts the thermal conductivity of nanofluids in the case of the flowing fluid. This suggests that the enhancement in the thermal conductivity of the flowing nanofluids due to the increase in temperature does not come from the thermal dispersion effect. It is more likely that the enhancement in heat transfer of the flowing nanofluids comes from the temperature-dependent interfacial layer effect. Therefore, the Leong et al.'s stationary model is again modified to include the effect of temperature variation on the thermal conductivity of the interfacial layer for different sizes of nanoparticles. This present model is then evaluated and compared with the other thermal conductivity models for the turbulent convective heat transfer in nanofluids along a uniformly heated tube. The results show that the present model is more general than the other models in the sense that it can predict both the temperature and the volume fraction dependence of the thermal conductivity of nanofluids for both non-flowing and flowing fluids. Also, it is found to be more accurate than the other models due to the inclusion of the effect of the temperature-dependent interfacial layer. In conclusion, the present model can accurately predict the changes in thermal conductivity of nanofluids due to the changes in volume fraction and temperature for

Finding the positive feedback loops underlying multi-stationarity

DEFF Research Database (Denmark)

Feliu, Elisenda; Wiuf, Carsten

2015-01-01

demonstrate the procedure by applying it to several examples of signaling processes, including a ubiquitination and an apoptosis network, and to models extracted from the Biomodels database. The procedure is implemented in Maple. CONCLUSIONS: We have developed and implemented an automated procedure to find...

A reanalysis of a behavioral intervention to prevent incident HIV infections: Including indirect effects in modeling outcomes of Project EXPLORE

Science.gov (United States)

Eaton, Lisa A.; Kalichman, Seth C.; Kenny, David A.; Harel, Ofer

2013-01-01

Background Project EXPLORE -- a large-scale, behavioral intervention tested among men who have sex with men (MSM) at-risk for HIV infection --was generally deemed as ineffective in reducing HIV incidence. Using novel and more precise data analytic techniques we reanalyzed Project EXPLORE by including both direct and indirect paths of intervention effects. Methods Data from 4,296 HIV negative MSM who participated in Project EXPLORE, which included ten sessions of behavioral risk reduction counseling completed from 1999-2005, were included in the analysis. We reanalyzed the data to include parameters that estimate the overtime effects of the intervention on unprotected anal sex and the over-time effects of the intervention on HIV status mediated by unprotected anal sex simultaneously in a single model. Results We found the indirect effect of intervention on HIV infection through unprotected anal sex to be statistically significant up through 12 months post-intervention, OR=.83, 95% CI=.72-.95. Furthermore, the intervention significantly reduced unprotected anal sex up through 18 months post-intervention, OR=.79, 95% CI=.63-.99. Discussion Our results reveal effects not tested in the original model that offer new insight into the effectiveness of a behavioral intervention for reducing HIV incidence. Project EXPLORE demonstrated that when tested against an evidence-based, effective control condition can result in reductions in rates of HIV acquisition at one year follow-up. Findings highlight the critical role of addressing behavioral risk reduction counseling in HIV prevention. PMID:23245226

Using statistical anomaly detection models to find clinical decision support malfunctions.

Science.gov (United States)

Ray, Soumi; McEvoy, Dustin S; Aaron, Skye; Hickman, Thu-Trang; Wright, Adam

2018-05-11

Malfunctions in Clinical Decision Support (CDS) systems occur due to a multitude of reasons, and often go unnoticed, leading to potentially poor outcomes. Our goal was to identify malfunctions within CDS systems. We evaluated 6 anomaly detection models: (1) Poisson Changepoint Model, (2) Autoregressive Integrated Moving Average (ARIMA) Model, (3) Hierarchical Divisive Changepoint (HDC) Model, (4) Bayesian Changepoint Model, (5) Seasonal Hybrid Extreme Studentized Deviate (SHESD) Model, and (6) E-Divisive with Median (EDM) Model and characterized their ability to find known anomalies. We analyzed 4 CDS alerts with known malfunctions from the Longitudinal Medical Record (LMR) and Epic® (Epic Systems Corporation, Madison, WI, USA) at Brigham and Women's Hospital, Boston, MA. The 4 rules recommend lead testing in children, aspirin therapy in patients with coronary artery disease, pneumococcal vaccination in immunocompromised adults and thyroid testing in patients taking amiodarone. Poisson changepoint, ARIMA, HDC, Bayesian changepoint and the SHESD model were able to detect anomalies in an alert for lead screening in children and in an alert for pneumococcal conjugate vaccine in immunocompromised adults. EDM was able to detect anomalies in an alert for monitoring thyroid function in patients on amiodarone. Malfunctions/anomalies occur frequently in CDS alert systems. It is important to be able to detect such anomalies promptly. Anomaly detection models are useful tools to aid such detections.

Including sugar cane in the agro-ecosystem model ORCHIDEE-STICS: calibration and validation

Science.gov (United States)

Valade, A.; Vuichard, N.; Ciais, P.; Viovy, N.

2011-12-01

Sugarcane is currently the most efficient bioenergy crop with regards to the energy produced per hectare. With approximately half the global bioethanol production in 2005, and a devoted land area expected to expand globally in the years to come, sugar cane is at the heart of the biofuel debate. Dynamic global vegetation models coupled with agronomical models are powerful and novel tools to tackle many of the environmental issues related to biofuels if they are carefully calibrated and validated against field observations. Here we adapt the agro-terrestrial model ORCHIDEE-STICS for sugar cane simulations. Observation data of LAI are used to evaluate the sensitivity of the model to parameters of nitrogen absorption and phenology, which are calibrated in a systematic way for six sites in Australia and La Reunion. We find that the optimal set of parameters is highly dependent on the sites' characteristics and that the model can reproduce satisfactorily the evolution of LAI. This careful calibration of ORCHIDEE-STICS for sugar cane biomass production for different locations and technical itineraries provides a strong basis for further analysis of the impacts of bioenergy-related land use change on carbon cycle budgets. As a next step, a sensitivity analysis is carried out to estimate the uncertainty of the model in biomass and carbon flux simulation due to its parameterization.

Modeling of Temperature-Dependent Noise in Silicon Nanowire FETs including Self-Heating Effects

Directory of Open Access Journals (Sweden)

P. Anandan

2014-01-01

Full Text Available Silicon nanowires are leading the CMOS era towards the downsizing limit and its nature will be effectively suppress the short channel effects. Accurate modeling of thermal noise in nanowires is crucial for RF applications of nano-CMOS emerging technologies. In this work, a perfect temperature-dependent model for silicon nanowires including the self-heating effects has been derived and its effects on device parameters have been observed. The power spectral density as a function of thermal resistance shows significant improvement as the channel length decreases. The effects of thermal noise including self-heating of the device are explored. Moreover, significant reduction in noise with respect to channel thermal resistance, gate length, and biasing is analyzed.

Seepage Model for PA Including Drift Collapse

International Nuclear Information System (INIS)

Li, G.; Tsang, C.

2000-01-01

The purpose of this Analysis/Model Report (AMR) is to document the predictions and analysis performed using the Seepage Model for Performance Assessment (PA) and the Disturbed Drift Seepage Submodel for both the Topopah Spring middle nonlithophysal and lower lithophysal lithostratigraphic units at Yucca Mountain. These results will be used by PA to develop the probability distribution of water seepage into waste-emplacement drifts at Yucca Mountain, Nevada, as part of the evaluation of the long term performance of the potential repository. This AMR is in accordance with the ''Technical Work Plan for Unsaturated Zone (UZ) Flow and Transport Process Model Report'' (CRWMS M andO 2000 [153447]). This purpose is accomplished by performing numerical simulations with stochastic representations of hydrological properties, using the Seepage Model for PA, and evaluating the effects of an alternative drift geometry representing a partially collapsed drift using the Disturbed Drift Seepage Submodel. Seepage of water into waste-emplacement drifts is considered one of the principal factors having the greatest impact of long-term safety of the repository system (CRWMS M andO 2000 [153225], Table 4-1). This AMR supports the analysis and simulation that are used by PA to develop the probability distribution of water seepage into drift, and is therefore a model of primary (Level 1) importance (AP-3.15Q, ''Managing Technical Product Inputs''). The intended purpose of the Seepage Model for PA is to support: (1) PA; (2) Abstraction of Drift-Scale Seepage; and (3) Unsaturated Zone (UZ) Flow and Transport Process Model Report (PMR). Seepage into drifts is evaluated by applying numerical models with stochastic representations of hydrological properties and performing flow simulations with multiple realizations of the permeability field around the drift. The Seepage Model for PA uses the distribution of permeabilities derived from air injection testing in niches and in the cross drift to

Seepage Model for PA Including Dift Collapse

Energy Technology Data Exchange (ETDEWEB)

G. Li; C. Tsang

2000-12-20

The purpose of this Analysis/Model Report (AMR) is to document the predictions and analysis performed using the Seepage Model for Performance Assessment (PA) and the Disturbed Drift Seepage Submodel for both the Topopah Spring middle nonlithophysal and lower lithophysal lithostratigraphic units at Yucca Mountain. These results will be used by PA to develop the probability distribution of water seepage into waste-emplacement drifts at Yucca Mountain, Nevada, as part of the evaluation of the long term performance of the potential repository. This AMR is in accordance with the ''Technical Work Plan for Unsaturated Zone (UZ) Flow and Transport Process Model Report'' (CRWMS M&O 2000 [153447]). This purpose is accomplished by performing numerical simulations with stochastic representations of hydrological properties, using the Seepage Model for PA, and evaluating the effects of an alternative drift geometry representing a partially collapsed drift using the Disturbed Drift Seepage Submodel. Seepage of water into waste-emplacement drifts is considered one of the principal factors having the greatest impact of long-term safety of the repository system (CRWMS M&O 2000 [153225], Table 4-1). This AMR supports the analysis and simulation that are used by PA to develop the probability distribution of water seepage into drift, and is therefore a model of primary (Level 1) importance (AP-3.15Q, ''Managing Technical Product Inputs''). The intended purpose of the Seepage Model for PA is to support: (1) PA; (2) Abstraction of Drift-Scale Seepage; and (3) Unsaturated Zone (UZ) Flow and Transport Process Model Report (PMR). Seepage into drifts is evaluated by applying numerical models with stochastic representations of hydrological properties and performing flow simulations with multiple realizations of the permeability field around the drift. The Seepage Model for PA uses the distribution of permeabilities derived from air injection testing in

Particle-based modeling of heterogeneous chemical kinetics including mass transfer.

Science.gov (United States)

Sengar, A; Kuipers, J A M; van Santen, Rutger A; Padding, J T

2017-08-01

Connecting the macroscopic world of continuous fields to the microscopic world of discrete molecular events is important for understanding several phenomena occurring at physical boundaries of systems. An important example is heterogeneous catalysis, where reactions take place at active surfaces, but the effective reaction rates are determined by transport limitations in the bulk fluid and reaction limitations on the catalyst surface. In this work we study the macro-micro connection in a model heterogeneous catalytic reactor by means of stochastic rotation dynamics. The model is able to resolve the convective and diffusive interplay between participating species, while including adsorption, desorption, and reaction processes on the catalytic surface. Here we apply the simulation methodology to a simple straight microchannel with a catalytic strip. Dimensionless Damkohler numbers are used to comment on the spatial concentration profiles of reactants and products near the catalyst strip and in the bulk. We end the discussion with an outlook on more complicated geometries and increasingly complex reactions.

Particle-based modeling of heterogeneous chemical kinetics including mass transfer

Science.gov (United States)

Sengar, A.; Kuipers, J. A. M.; van Santen, Rutger A.; Padding, J. T.

2017-08-01

Connecting the macroscopic world of continuous fields to the microscopic world of discrete molecular events is important for understanding several phenomena occurring at physical boundaries of systems. An important example is heterogeneous catalysis, where reactions take place at active surfaces, but the effective reaction rates are determined by transport limitations in the bulk fluid and reaction limitations on the catalyst surface. In this work we study the macro-micro connection in a model heterogeneous catalytic reactor by means of stochastic rotation dynamics. The model is able to resolve the convective and diffusive interplay between participating species, while including adsorption, desorption, and reaction processes on the catalytic surface. Here we apply the simulation methodology to a simple straight microchannel with a catalytic strip. Dimensionless Damkohler numbers are used to comment on the spatial concentration profiles of reactants and products near the catalyst strip and in the bulk. We end the discussion with an outlook on more complicated geometries and increasingly complex reactions.

Conceptual modeling of postmortem evaluation findings to describe dairy cow deaths.

Science.gov (United States)

McConnel, C S; Garry, F B; Hill, A E; Lombard, J E; Gould, D H

2010-01-01

Dairy cow mortality levels in the United States are excessive and increasing over time. To better define cause and effect and combat rising mortality, clearer definitions of the reasons that cows die need to be acquired through thorough necropsy-based postmortem evaluations. The current study focused on organizing information generated from postmortem evaluations into a monitoring system that is based on the fundamentals of conceptual modeling and that will potentially be translatable into on-farm relational databases. This observational study was conducted on 3 high-producing, commercial dairies in northern Colorado. Throughout the study period a thorough postmortem evaluation was performed by veterinarians on cows that died on each dairy. Postmortem data included necropsy findings, life-history features (e.g., birth date, lactation number, lactational and reproductive status), clinical history and treatments, and pertinent aspects of operational management that were subject to change and considered integral to the poor outcome. During this study, 174 postmortem evaluations were performed. Postmortem evaluation results were conceptually modeled to view each death within the context of the web of factors influencing the dairy and the cow. Categories were formulated describing mortality in terms of functional characteristics potentially amenable to easy performance evaluation, management oversight, and research. In total, 21 death categories with 7 category themes were created. Themes included specific disease processes with variable etiologies, failure of disease recognition or treatment, traumatic events, multifactorial failures linked to transition or negative energy balance issues, problems with feed management, miscellaneous events not amenable to prevention or treatment, and undetermined causes. Although postmortem evaluations provide the relevant information necessary for framing a cow's death, a restructuring of on-farm databases is needed to integrate this

Dipole model analysis of highest precision HERA data, including very low Q"2's

International Nuclear Information System (INIS)

Luszczak, A.; Kowalski, H.

2016-12-01

We analyse, within a dipole model, the final, inclusive HERA DIS cross section data in the low χ region, using fully correlated errors. We show, that these highest precision data are very well described within the dipole model framework starting from Q"2 values of 3.5 GeV"2 to the highest values of Q"2=250 GeV"2. To analyze the saturation effects we evaluated the data including also the very low 0.35< Q"2 GeV"2 region. The fits including this region show a preference of the saturation ansatz.

A speech production model including the nasal Cavity

DEFF Research Database (Denmark)

Olesen, Morten

In order to obtain articulatory analysis of speech production the model is improved. the standard model, as used in LPC analysis, to a large extent only models the acoustic properties of speech signal as opposed to articulatory modelling of the speech production. In spite of this the LPC model...... is by far the most widely used model in speech technology....

Including an ocean carbon cycle model into iLOVECLIM (v1.0)

NARCIS (Netherlands)

Bouttes, N.; Roche, D.M.V.A.P.; Mariotti, V.; Bopp, L.

2015-01-01

The atmospheric carbon dioxide concentration plays a crucial role in the radiative balance and as such has a strong influence on the evolution of climate. Because of the numerous interactions between climate and the carbon cycle, it is necessary to include a model of the carbon cycle within a

Refitting density dependent relativistic model parameters including Center-of-Mass corrections

International Nuclear Information System (INIS)

Avancini, Sidney S.; Marinelli, Jose R.; Carlson, Brett Vern

2011-01-01

Full text: Relativistic mean field models have become a standard approach for precise nuclear structure calculations. After the seminal work of Serot and Walecka, which introduced a model Lagrangian density where the nucleons interact through the exchange of scalar and vector mesons, several models were obtained through its generalization, including other meson degrees of freedom, non-linear meson interactions, meson-meson interactions, etc. More recently density dependent coupling constants were incorporated into the Walecka-like models, which are then extensively used. In particular, for these models a connection with the density functional theory can be established. Due to the inherent difficulties presented by field theoretical models, only the mean field approximation is used for the solution of these models. In order to calculate finite nuclei properties in the mean field approximation, a reference set has to be fixed and therefore the translational symmetry is violated. It is well known that in such case spurious effects due to the center-of-mass (COM) motion are present, which are more pronounced for light nuclei. In a previous work we have proposed a technique based on the Pierls-Yoccoz projection operator applied to the mean-field relativistic solution, in order to project out spurious COM contributions. In this work we obtain a new fitting for the density dependent parameters of a density dependent hadronic model, taking into account the COM corrections. Our fitting is obtained taking into account the charge radii and binding energies for He 4 , O 16 , Ca 40 , Ca 48 , Ni 56 , Ni 68 , Sn 100 , Sn 132 and Pb 208 . We show that the nuclear observables calculated using our fit are of a quality comparable to others that can be found in the literature, with the advantage that now a translational invariant many-body wave function is at our disposal. (author)

A numerical model including PID control of a multizone crystal growth furnace

Science.gov (United States)

Panzarella, Charles H.; Kassemi, Mohammad

1992-01-01

This paper presents a 2D axisymmetric combined conduction and radiation model of a multizone crystal growth furnace. The model is based on a programmable multizone furnace (PMZF) designed and built at NASA Lewis Research Center for growing high quality semiconductor crystals. A novel feature of this model is a control algorithm which automatically adjusts the power in any number of independently controlled heaters to establish the desired crystal temperatures in the furnace model. The control algorithm eliminates the need for numerous trial and error runs previously required to obtain the same results. The finite element code, FIDAP, used to develop the furnace model, was modified to directly incorporate the control algorithm. This algorithm, which presently uses PID control, and the associated heat transfer model are briefly discussed. Together, they have been used to predict the heater power distributions for a variety of furnace configurations and desired temperature profiles. Examples are included to demonstrate the effectiveness of the PID controlled model in establishing isothermal, Bridgman, and other complicated temperature profies in the sample. Finally, an example is given to show how the algorithm can be used to change the desired profile with time according to a prescribed temperature-time evolution.

Safe distance car-following model including backward-looking and its stability analysis

Science.gov (United States)

Yang, Da; Jin, Peter Jing; Pu, Yun; Ran, Bin

2013-03-01

The focus of this paper is the car-following behavior including backward-looking, simply called the bi-directional looking car-following behavior. This study is motivated by the potential changes of the physical properties of traffic flow caused by the fast developing intelligent transportation system (ITS), especially the new connected vehicle technology. Existing studies on this topic focused on general motors (GM) models and optimal velocity (OV) models. The safe distance car-following model, Gipps' model, which is more widely used in practice have not drawn too much attention in the bi-directional looking context. This paper explores the property of the bi-directional looking extension of Gipps' safe distance model. The stability condition of the proposed model is derived using the linear stability theory and is verified using numerical simulations. The impacts of the driver and vehicle characteristics appeared in the proposed model on the traffic flow stability are also investigated. It is found that taking into account the backward-looking effect in car-following has three types of effect on traffic flow: stabilizing, destabilizing and producing non-physical phenomenon. This conclusion is more sophisticated than the study results based on the OV bi-directional looking car-following models. Moreover, the drivers who have the smaller reaction time or the larger additional delay and think the other vehicles have larger maximum decelerations can stabilize traffic flow.

SPheno 3.1: extensions including flavour, CP-phases and models beyond the MSSM

Science.gov (United States)

Porod, W.; Staub, F.

2012-11-01

We describe recent extensions of the program SPhenoincluding flavour aspects, CP-phases, R-parity violation and low energy observables. In case of flavour mixing all masses of supersymmetric particles are calculated including the complete flavour structure and all possible CP-phases at the 1-loop level. We give details on implemented seesaw models, low energy observables and the corresponding extension of the SUSY Les Houches Accord. Moreover, we comment on the possibilities to include MSSM extensions in SPheno. Catalogue identifier: ADRV_v2_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADRV_v2_0.html Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 154062 No. of bytes in distributed program, including test data, etc.: 1336037 Distribution format: tar.gz Programming language: Fortran95. Computer: PC running under Linux, should run in every Unix environment. Operating system: Linux, Unix. Classification: 11.6. Catalogue identifier of previous version: ADRV_v1_0 Journal reference of previous version: Comput. Phys. Comm. 153(2003)275 Does the new version supersede the previous version?: Yes Nature of problem: The first issue is the determination of the masses and couplings of supersymmetric particles in various supersymmetric models, the R-parity conserved MSSM with generation mixing and including CP-violating phases, various seesaw extensions of the MSSM and the MSSM with bilinear R-parity breaking. Low energy data on Standard Model fermion masses, gauge couplings and electroweak gauge boson masses serve as constraints. Radiative corrections from supersymmetric particles to these inputs must be calculated. Theoretical constraints on the soft SUSY breaking parameters from a high scale theory are imposed and the parameters at the electroweak scale are obtained from the

Enhanced battery model including temperature effects

NARCIS (Netherlands)

Rosca, B.; Wilkins, S.

2013-01-01

Within electric and hybrid vehicles, batteries are used to provide/buffer the energy required for driving. However, battery performance varies throughout the temperature range specific to automotive applications, and as such, models that describe this behaviour are required. This paper presents a

Models of epidemics: when contact repetition and clustering should be included

Directory of Open Access Journals (Sweden)

Scholz Roland W

2009-06-01

Full Text Available Abstract Background The spread of infectious disease is determined by biological factors, e.g. the duration of the infectious period, and social factors, e.g. the arrangement of potentially contagious contacts. Repetitiveness and clustering of contacts are known to be relevant factors influencing the transmission of droplet or contact transmitted diseases. However, we do not yet completely know under what conditions repetitiveness and clustering should be included for realistically modelling disease spread. Methods We compare two different types of individual-based models: One assumes random mixing without repetition of contacts, whereas the other assumes that the same contacts repeat day-by-day. The latter exists in two variants, with and without clustering. We systematically test and compare how the total size of an outbreak differs between these model types depending on the key parameters transmission probability, number of contacts per day, duration of the infectious period, different levels of clustering and varying proportions of repetitive contacts. Results The simulation runs under different parameter constellations provide the following results: The difference between both model types is highest for low numbers of contacts per day and low transmission probabilities. The number of contacts and the transmission probability have a higher influence on this difference than the duration of the infectious period. Even when only minor parts of the daily contacts are repetitive and clustered can there be relevant differences compared to a purely random mixing model. Conclusion We show that random mixing models provide acceptable estimates of the total outbreak size if the number of contacts per day is high or if the per-contact transmission probability is high, as seen in typical childhood diseases such as measles. In the case of very short infectious periods, for instance, as in Norovirus, models assuming repeating contacts will also behave

Review of animal models used to study effects of bee products on wound healing: findings and applications

Directory of Open Access Journals (Sweden)

Hananeh Wael M.

2015-09-01

Full Text Available Non-healing wounds are associated with high morbidity and might greatly impact a patient’s well-being and economic status. For many years, scientific research has focused on developing and testing several natural and synthetic materials that enhance the rate of wound healing or eliminate healing complications. Honey has been used for thousands of years as a traditional remedy for many ailments. Recently, honey has reemerged as a promising wound care product especially for infected wounds and for wounds in diabetic patients. In addition to its proposed potent broad-spectrum antibacterial properties, honey has been claimed to promote wound healing by reducing wound hyperaemia, oedema, and exudate, and by stimulating angiogenesis, granulation tissue formation and epithelialisation. Several animal models, including large animals, dogs and cats, and different species of laboratory animals have been used to investigate the efficacy and safety of various natural and synthetic agents for wound healing enhancement. Interpreting the results obtained by these studies is, however, rather difficult and usually hampered by many limiting factors including great variation in types and origins of honey, the type of animal species used as models, the type of wounds, the number of animals, the number and type of controls, and variation in treatment protocols. In this article, we provide a comprehensive review of the most recent findings and applications of published experimental and clinical trials using honey as an agent for wound healing enhancement in different animal models.

[Ultrasound findings in rhabdomyolysis].

Science.gov (United States)

Carrillo-Esper, Raúl; Galván-Talamantes, Yazmin; Meza-Ayala, Cynthia Margarita; Cruz-Santana, Julio Alberto; Bonilla-Reséndiz, Luis Ignacio

Rhabdomyolysis is defined as skeletal muscle necrosis. Ultrasound assessment has recently become a useful tool for the diagnosis and monitoring of muscle diseases, including rhabdomyolysis. A case is presented on the ultrasound findings in a patient with rhabdomyolysis. To highlight the importance of ultrasound as an essential part in the diagnosis in rhabdomyolysis, to describe the ultrasound findings, and review the literature. A 30 year-old with post-traumatic rhabdomyolysis of both thighs. Ultrasound was performed using a Philips Sparq model with a high-frequency linear transducer (5-10MHz), in low-dimensional scanning mode (2D), in longitudinal and transverse sections at the level of both thighs. The images obtained showed disorganisation of the orientation of the muscle fibres, ground glass image, thickening of the muscular fascia, and the presence of anechoic areas. Ultrasound is a useful tool in the evaluation of rhabdomyolysis. Copyright © 2015 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

What Can Be Learned From a Laboratory Model of Conceptual Change? Descriptive Findings and Methodological Issues

Science.gov (United States)

Ohlsson, Stellan; Cosejo, David G.

2014-07-01

The problem of how people process novel and unexpected information— deep learning (Ohlsson in Deep learning: how the mind overrides experience. Cambridge University Press, New York, 2011)—is central to several fields of research, including creativity, belief revision, and conceptual change. Researchers have not converged on a single theory for conceptual change, nor has any one theory been decisively falsified. One contributing reason is the difficulty of collecting informative data in this field. We propose that the commonly used methodologies of historical analysis, classroom interventions, and developmental studies, although indispensible, can be supplemented with studies of laboratory models of conceptual change. We introduce re- categorization, an experimental paradigm in which learners transition from one definition of a categorical concept to another, incompatible definition of the same concept, a simple form of conceptual change. We describe a re-categorization experiment, report some descriptive findings pertaining to the effects of category complexity, the temporal unfolding of learning, and the nature of the learner's final knowledge state. We end with a brief discussion of ways in which the re-categorization model can be improved.

Community referral for presumptive TB in Nigeria: a comparison of four models of active case finding

Directory of Open Access Journals (Sweden)

A. O. Adejumo

2016-02-01

Full Text Available Abstract Background Engagement of communities and civil society organizations is a critical part of the Post-2015 End TB Strategy. Since 2007, many models of community referral have been implemented to boost TB case detection in Nigeria. Yet clear insights into the comparative TB yield from particular approaches have been limited. Methods We compared four models of active case finding in three Nigerian states. Data on presumptive TB case referral by community workers (CWs, TB diagnoses among referred clients, active case finding model characteristics, and CWs compensation details for 2012 were obtained from implementers and CWs via interviews and log book review. Self-reported performance data were triangulated against routine surveillance data to assess concordance. Analysis focused on assessing the predictors of presumptive TB referral. Results CWs referred 4–22 % of presumptive TB clients tested, and 4–24 % of the total TB cases detected. The annual median referral per CW ranged widely among the models from 1 to 48 clients, with an overall average of 13.4 referrals per CW. The highest median referrals (48 per CW/yr and mean TB diagnoses (7.1/yr per CW (H =70.850, p < 0.001 was obtained by the model with training supervision, and $80/quarterly payments (Comprehensive Quotas-Oriented model. The model with irregularly supervised, trained, and compensated CWs contributed the least to TB case detection with a median of 13 referrals per CW/yr and mean of 0.53 TB diagnoses per CW/yr. Hours spent weekly on presumptive TB referral made the strongest unique contribution (Beta = 0.514, p < 0.001 to explaining presumptive TB referral after controlling for other variables. Conclusion All community based TB case-finding projects studied referred a relative low number of symptomatic individuals. The study shows that incentivized referral, appropriate selection of CWs, supportive supervision, leveraged treatment support roles, and a

Dynamic model of a micro-tubular solid oxide fuel cell stack including an integrated cooling system

Science.gov (United States)

Hering, Martin; Brouwer, Jacob; Winkler, Wolfgang

2017-02-01

A novel dynamic micro-tubular solid oxide fuel cell (MT-SOFC) and stack model including an integrated cooling system is developed using a quasi three-dimensional, spatially resolved, transient thermodynamic, physical and electrochemical model that accounts for the complex geometrical relations between the cells and cooling-tubes. The modeling approach includes a simplified tubular geometry and stack design including an integrated cooling structure, detailed pressure drop and gas property calculations, the electrical and physical constraints of the stack design that determine the current, as well as control strategies for the temperature. Moreover, an advanced heat transfer balance with detailed radiative heat transfer between the cells and the integrated cooling-tubes, convective heat transfer between the gas flows and the surrounding structures and conductive heat transfer between the solid structures inside of the stack, is included. The detailed model can be used as a design basis for the novel MT-SOFC stack assembly including an integrated cooling system, as well as for the development of a dynamic system control strategy. The evaluated best-case design achieves very high electrical efficiency between around 75 and 55% in the entire power density range between 50 and 550 mW /cm2 due to the novel stack design comprising an integrated cooling structure.

Finite element modeling of contaminant transport in soils including the effect of chemical reactions.

Science.gov (United States)

Javadi, A A; Al-Najjar, M M

2007-05-17

The movement of chemicals through soils to the groundwater is a major cause of degradation of water resources. In many cases, serious human and stock health implications are associated with this form of pollution. Recent studies have shown that the current models and methods are not able to adequately describe the leaching of nutrients through soils, often underestimating the risk of groundwater contamination by surface-applied chemicals, and overestimating the concentration of resident solutes. Furthermore, the effect of chemical reactions on the fate and transport of contaminants is not included in many of the existing numerical models for contaminant transport. In this paper a numerical model is presented for simulation of the flow of water and air and contaminant transport through unsaturated soils with the main focus being on the effects of chemical reactions. The governing equations of miscible contaminant transport including advection, dispersion-diffusion and adsorption effects together with the effect of chemical reactions are presented. The mathematical framework and the numerical implementation of the model are described in detail. The model is validated by application to a number of test cases from the literature and is then applied to the simulation of a physical model test involving transport of contaminants in a block of soil with particular reference to the effects of chemical reactions. Comparison of the results of the numerical model with the experimental results shows that the model is capable of predicting the effects of chemical reactions with very high accuracy. The importance of consideration of the effects of chemical reactions is highlighted.

Including Effects of Water Stress on Dead Organic Matter Decay to a Forest Carbon Model

Science.gov (United States)

Kim, H.; Lee, J.; Han, S. H.; Kim, S.; Son, Y.

2017-12-01

Decay of dead organic matter is a key process of carbon (C) cycling in forest ecosystems. The change in decay rate depends on temperature sensitivity and moisture conditions. The Forest Biomass and Dead organic matter Carbon (FBDC) model includes a decay sub-model considering temperature sensitivity, yet does not consider moisture conditions as drivers of the decay rate change. This study aimed to improve the FBDC model by including a water stress function to the decay sub-model. Also, soil C sequestration under climate change with the FBDC model including the water stress function was simulated. The water stress functions were determined with data from decomposition study on Quercus variabilis forests and Pinus densiflora forests of Korea, and adjustment parameters of the functions were determined for both species. The water stress functions were based on the ratio of precipitation to potential evapotranspiration. Including the water stress function increased the explained variances of the decay rate by 19% for the Q. variabilis forests and 7% for the P. densiflora forests, respectively. The increase of the explained variances resulted from large difference in temperature range and precipitation range across the decomposition study plots. During the period of experiment, the mean annual temperature range was less than 3°C, while the annual precipitation ranged from 720mm to 1466mm. Application of the water stress functions to the FBDC model constrained increasing trend of temperature sensitivity under climate change, and thus increased the model-estimated soil C sequestration (Mg C ha-1) by 6.6 for the Q. variabilis forests and by 3.1 for the P. densiflora forests, respectively. The addition of water stress functions increased reliability of the decay rate estimation and could contribute to reducing the bias in estimating soil C sequestration under varying moisture condition. Acknowledgement: This study was supported by Korea Forest Service (2017044B10-1719-BB01)

A unitarized meson model including color Coulomb interaction

International Nuclear Information System (INIS)

Metzger, Kees.

1990-01-01

Ch. 1 gives a general introduction into the problem field of the thesis. It discusses in how far the internal structure of mesons is understood theoretically and which models exist. It discusses from a phenomenological point of view the problem of confinement indicates how quark models of mesons may provide insight in this phenomenon. In ch. 2 the formal theory of scattering in a system with confinement is given. It is shown how a coupled channel (CC) description and the work of other authors fit into this general framework. Explicit examples and arguments are given to support the CC treatment of such a system. In ch. 3 the full coupled-channel model as is employed in this thesis is presented. On the basis of arguments from the former chapters and the observed regularities in the experimental data, the choices underlying the model are supported. In this model confinement is described with a mass-dependent harmonic-oscillator potential and the presence of open (meson-meson) channels plays an essential role. In ch. 4 the unitarized model is applied to light scalar meson resonances. In this regime the contribution of the open channels is considerable. It is demonstrated that the model parameters as used for the description of the pseudo-scalar and vector mesons, unchanged can be used for the description of these mesons. Ch. 5 treats the color-Coulomb interaction. There the effect of the Coulomb interaction is studied in simple models without decay. The results of incorporating the color-Coulomb interaction into the full CC model are given in ch.6. Ch. 7 discusses the results of the previous chapters and the present status of the model. (author). 182 refs.; 16 figs.; 33 tabs

Pengaruh Model Pembelajaran Kooperatif Tipe Find Someone Who terhadap Hasil Belajar Matematika Siswa

Directory of Open Access Journals (Sweden)

Jumrawarsi Jumrawarsi

2017-10-01

Full Text Available Penelitian ini bertujuan untuk mengetahui pengaruh penerapan model pembelajaran kooperatif tipe Find Someone Who terhadap hasil belajar matematika siswa kelas X MAN Lubuk Alung. Jenis penelitian pra-eksperimen dengan rancangan penelitian randomized control group only design. Populasinya adalah seluruh siswa kelas X MAN Lubuk Alung tahun pelajaran 2015/2016. Pengambilan sampel dari populasi menggunakan teknik purposive sampling. kelas eksperimen adalah kelas X2 dan kelas kontrol kelas X3. Berdasarkan analisis data, diperoleh nilai rata-rata pada kelas eksperimen sebesar 74,235 dan nilai rata-rata pada kelas kontrol sebesar 67,411 artinya rata-rata kelas eksperimen lebih tinggi dari kelas kontrol. Hasil analisis uji-t diperoleh t-hitung = 2,251 dan t-tabel = 1,669 pada taraf nyata 0,05 dengan dk = 66. Hasil perhitungan terlihat t-hitung > t-tabel berarti H0 ditolak, Jadi dapat disimpulkan bahwa terdapat pengaruh penerapan model pembelajaran kooperatif tipe Find Someone Who terhadap hasil belajar matematika siswa kelas X MAN Lubuk Alung.  Kata kunci: Pembelajaran Kooperatif tipe Find Someone Who, hasil belajar  This research is aimed to clarify the effectiveness of the applying of the cooperative learning Find Someone Who strategy Toward Learning Outcome Mathematics Students at MAN Lubuk Alung. The design of this study was a randomized experiment. The population of the research was all students of grade X 2015/2016 academic year. The sample was two classes; both classes were X2 as an experimental class and class X3 as a control class. Based on data, the result of this research shown that means a score of experiment class was 74.235 and average math learning outcomes mean control class was 67.411 averages higher than the experimental class. The results of t-test analysis were obtained t = 2,251 and t table = 1,669 on the real level of 0.05 with df = 66. t calculate> t table, then H0 was rejected and H1 was accepted, so it is concluded that the

Gene finding with a hidden Markov model of genome structure and evolution

DEFF Research Database (Denmark)

Pedersen, Jakob Skou; Hein, Jotun

2003-01-01

-specific evolutionary models based on a phylogenetic tree. All parameters can be estimated by maximum likelihood, including the phylogenetic tree. It can handle any number of aligned genomes, using their phylogenetic tree to model the evolutionary correlations. The time complexity of all algorithms used for handling...

Single-Phase Bundle Flows Including Macroscopic Turbulence Model

Energy Technology Data Exchange (ETDEWEB)

Lee, Seung Jun; Yoon, Han Young [KAERI, Daejeon (Korea, Republic of); Yoon, Seok Jong; Cho, Hyoung Kyu [Seoul National University, Seoul (Korea, Republic of)

2016-05-15

To deal with various thermal hydraulic phenomena due to rapid change of fluid properties when an accident happens, securing mechanistic approaches as much as possible may reduce the uncertainty arising from improper applications of the experimental models. In this study, the turbulence mixing model, which is well defined in the subchannel analysis code such as VIPRE, COBRA, and MATRA by experiments, is replaced by a macroscopic k-e turbulence model, which represents the aspect of mathematical derivation. The performance of CUPID with macroscopic turbulence model is validated against several bundle experiments: CNEN 4x4 and PNL 7x7 rod bundle tests. In this study, the macroscopic k-e model has been validated for the application to subchannel analysis. It has been implemented in the CUPID code and validated against CNEN 4x4 and PNL 7x7 rod bundle tests. The results showed that the macroscopic k-e turbulence model can estimate the experiments properly.

A High-Rate, Single-Crystal Model including Phase Transformations, Plastic Slip, and Twinning

Energy Technology Data Exchange (ETDEWEB)

Addessio, Francis L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Bronkhorst, Curt Allan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Bolme, Cynthia Anne [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Explosive Science and Shock Physics Division; Brown, Donald William [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Materials Science and Technology Division; Cerreta, Ellen Kathleen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Materials Science and Technology Division; Lebensohn, Ricardo A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Materials Science and Technology Division; Lookman, Turab [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Luscher, Darby Jon [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Mayeur, Jason Rhea [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Morrow, Benjamin M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Materials Science and Technology Division; Rigg, Paulo A. [Washington State Univ., Pullman, WA (United States). Dept. of Physics. Inst. for Shock Physics

2016-08-09

An anisotropic, rate-­dependent, single-­crystal approach for modeling materials under the conditions of high strain rates and pressures is provided. The model includes the effects of large deformations, nonlinear elasticity, phase transformations, and plastic slip and twinning. It is envisioned that the model may be used to examine these coupled effects on the local deformation of materials that are subjected to ballistic impact or explosive loading. The model is formulated using a multiplicative decomposition of the deformation gradient. A plate impact experiment on a multi-­crystal sample of titanium was conducted. The particle velocities at the back surface of three crystal orientations relative to the direction of impact were measured. Molecular dynamics simulations were conducted to investigate the details of the high-­rate deformation and pursue issues related to the phase transformation for titanium. Simulations using the single crystal model were conducted and compared to the high-­rate experimental data for the impact loaded single crystals. The model was found to capture the features of the experiments.

Climate change: Recent findings

International Nuclear Information System (INIS)

Hesselmans, G.H.F.M.

1993-08-01

In the late eighties several reports have been published on climate change and sea level rise. In the meantime insights may have changed due to the availability of better and more observations and/or more advanced climate models. The aim of this report is to present the most recent findings with respect to climate change, in particular of sea level rise, storm surges and river peak flows. These climate factors are important for the safety of low-lying areas with respect to coastal erosion and flooding. In the first chapters a short review is presented of a few of the eighties reports. Furthermore, the predictions by state of the art climate models at that time are given. The reports from the eighties should be considered as 'old' information, whereas the IPCC supplement and work, for example, by Wigley should be considered as new information. To assess the latest findings two experts in this field were interviewed: dr J. Oerlemans and dr C.J.E. Schuurmans, a climate expert from the Royal Netherlands Meteorological Institute (KNMI). Their views are presented together with results published in recent papers on the subject. On the basis of this assessment, the report presents current knowledge regarding predictions of climate change (including sea-level rise) over the next century, together with an assessment of the uncertainties associated with these predictions. 14 figs., 11 tabs., 24 refs

Including model uncertainty in risk-informed decision making

International Nuclear Information System (INIS)

Reinert, Joshua M.; Apostolakis, George E.

2006-01-01

Model uncertainties can have a significant impact on decisions regarding licensing basis changes. We present a methodology to identify basic events in the risk assessment that have the potential to change the decision and are known to have significant model uncertainties. Because we work with basic event probabilities, this methodology is not appropriate for analyzing uncertainties that cause a structural change to the model, such as success criteria. We use the risk achievement worth (RAW) importance measure with respect to both the core damage frequency (CDF) and the change in core damage frequency (ΔCDF) to identify potentially important basic events. We cross-check these with generically important model uncertainties. Then, sensitivity analysis is performed on the basic event probabilities, which are used as a proxy for the model parameters, to determine how much error in these probabilities would need to be present in order to impact the decision. A previously submitted licensing basis change is used as a case study. Analysis using the SAPHIRE program identifies 20 basic events as important, four of which have model uncertainties that have been identified in the literature as generally important. The decision is fairly insensitive to uncertainties in these basic events. In three of these cases, one would need to show that model uncertainties would lead to basic event probabilities that would be between two and four orders of magnitude larger than modeled in the risk assessment before they would become important to the decision. More detailed analysis would be required to determine whether these higher probabilities are reasonable. Methods to perform this analysis from the literature are reviewed and an example is demonstrated using the case study

An Evacuation Model for Passenger Ships That Includes the Influence of Obstacles in Cabins

Directory of Open Access Journals (Sweden)

Baocheng Ni

2017-01-01

Full Text Available Passenger behavior and ship environment are the key factors affecting evacuation efficiency. However, current studies ignore the interior layout of passenger ship cabins and treat the cabins as empty rooms. To investigate the influence of obstacles (e.g., tables and stools on cabin evacuation, we propose an agent-based social force model for advanced evacuation analysis of passenger ships; this model uses a goal-driven submodel to determine a plan and an extended social force submodel to govern the movement of passengers. The extended social force submodel considers the interaction forces between the passengers, crew, and obstacles and minimises the range of these forces to improve computational efficiency. We drew the following conclusions based on a series of evacuation simulations conducted in this study: (1 the proposed model endows the passenger with the behaviors of bypassing and crossing obstacles, (2 funnel-shaped exits from cabins can improve evacuation efficiency, and (3 as the exit angle increases, the evacuation time also increases. These findings offer ship designers some insight towards increasing the safety of large passenger ships.

Children and adolescents' internal models of food-sharing behavior include complex evaluations of contextual factors.

Science.gov (United States)

Markovits, Henry; Benenson, Joyce F; Kramer, Donald L

2003-01-01

This study examined internal representations of food sharing in 589 children and adolescents (8-19 years of age). Questionnaires, depicting a variety of contexts in which one person was asked to share a resource with another, were used to examine participants' expectations of food-sharing behavior. Factors that were varied included the value of the resource, the relation between the two depicted actors, the quality of this relation, and gender. Results indicate that internal models of food-sharing behavior showed systematic patterns of variation, demonstrating that individuals have complex contextually based internal models at all ages, including the youngest. Examination of developmental changes in use of individual patterns is consistent with the idea that internal models reflect age-specific patterns of interactions while undergoing a process of progressive consolidation.

Utility of Social Modeling for Proliferation Assessment - Preliminary Findings

International Nuclear Information System (INIS)

Coles, Garill A.; Gastelum, Zoe N.; Brothers, Alan J.; Thompson, Sandra E.

2009-01-01

Often the methodologies for assessing proliferation risk are focused around the inherent vulnerability of nuclear energy systems and associated safeguards. For example an accepted approach involves ways to measure the intrinsic and extrinsic barriers to potential proliferation. This paper describes preliminary investigation into non-traditional use of social and cultural information to improve proliferation assessment and advance the approach to assessing nuclear material diversion. Proliferation resistance assessment, safeguard assessments and related studies typically create technical information about the vulnerability of a nuclear energy system to diversion of nuclear material. The purpose of this research project is to find ways to integrate social information with technical information by explicitly considering the role of culture, groups and/or individuals to factors that impact the possibility of proliferation. When final, this work is expected to describe and demonstrate the utility of social science modeling in proliferation and proliferation risk assessments.

The Watts-Strogatz network model developed by including degree distribution: theory and computer simulation

Energy Technology Data Exchange (ETDEWEB)

Chen, Y W [Surface Physics Laboratory and Department of Physics, Fudan University, Shanghai 200433 (China); Zhang, L F [Surface Physics Laboratory and Department of Physics, Fudan University, Shanghai 200433 (China); Huang, J P [Surface Physics Laboratory and Department of Physics, Fudan University, Shanghai 200433 (China)

2007-07-20

By using theoretical analysis and computer simulations, we develop the Watts-Strogatz network model by including degree distribution, in an attempt to improve the comparison between characteristic path lengths and clustering coefficients predicted by the original Watts-Strogatz network model and those of the real networks with the small-world property. Good agreement between the predictions of the theoretical analysis and those of the computer simulations has been shown. It is found that the developed Watts-Strogatz network model can fit the real small-world networks more satisfactorily. Some other interesting results are also reported by adjusting the parameters in a model degree-distribution function. The developed Watts-Strogatz network model is expected to help in the future analysis of various social problems as well as financial markets with the small-world property.

The Watts-Strogatz network model developed by including degree distribution: theory and computer simulation

International Nuclear Information System (INIS)

Chen, Y W; Zhang, L F; Huang, J P

2007-01-01

By using theoretical analysis and computer simulations, we develop the Watts-Strogatz network model by including degree distribution, in an attempt to improve the comparison between characteristic path lengths and clustering coefficients predicted by the original Watts-Strogatz network model and those of the real networks with the small-world property. Good agreement between the predictions of the theoretical analysis and those of the computer simulations has been shown. It is found that the developed Watts-Strogatz network model can fit the real small-world networks more satisfactorily. Some other interesting results are also reported by adjusting the parameters in a model degree-distribution function. The developed Watts-Strogatz network model is expected to help in the future analysis of various social problems as well as financial markets with the small-world property

The Benefits of Including Clinical Factors in Rectal Normal Tissue Complication Probability Modeling After Radiotherapy for Prostate Cancer

International Nuclear Information System (INIS)

Defraene, Gilles; Van den Bergh, Laura; Al-Mamgani, Abrahim; Haustermans, Karin; Heemsbergen, Wilma; Van den Heuvel, Frank; Lebesque, Joos V.

2012-01-01

Purpose: To study the impact of clinical predisposing factors on rectal normal tissue complication probability modeling using the updated results of the Dutch prostate dose-escalation trial. Methods and Materials: Toxicity data of 512 patients (conformally treated to 68 Gy [n = 284] and 78 Gy [n = 228]) with complete follow-up at 3 years after radiotherapy were studied. Scored end points were rectal bleeding, high stool frequency, and fecal incontinence. Two traditional dose-based models (Lyman-Kutcher-Burman (LKB) and Relative Seriality (RS) and a logistic model were fitted using a maximum likelihood approach. Furthermore, these model fits were improved by including the most significant clinical factors. The area under the receiver operating characteristic curve (AUC) was used to compare the discriminating ability of all fits. Results: Including clinical factors significantly increased the predictive power of the models for all end points. In the optimal LKB, RS, and logistic models for rectal bleeding and fecal incontinence, the first significant (p = 0.011–0.013) clinical factor was “previous abdominal surgery.” As second significant (p = 0.012–0.016) factor, “cardiac history” was included in all three rectal bleeding fits, whereas including “diabetes” was significant (p = 0.039–0.048) in fecal incontinence modeling but only in the LKB and logistic models. High stool frequency fits only benefitted significantly (p = 0.003–0.006) from the inclusion of the baseline toxicity score. For all models rectal bleeding fits had the highest AUC (0.77) where it was 0.63 and 0.68 for high stool frequency and fecal incontinence, respectively. LKB and logistic model fits resulted in similar values for the volume parameter. The steepness parameter was somewhat higher in the logistic model, also resulting in a slightly lower D 50 . Anal wall DVHs were used for fecal incontinence, whereas anorectal wall dose best described the other two endpoints. Conclusions

The Benefits of Including Clinical Factors in Rectal Normal Tissue Complication Probability Modeling After Radiotherapy for Prostate Cancer

Energy Technology Data Exchange (ETDEWEB)

Defraene, Gilles, E-mail: gilles.defraene@uzleuven.be [Radiation Oncology Department, University Hospitals Leuven, Leuven (Belgium); Van den Bergh, Laura [Radiation Oncology Department, University Hospitals Leuven, Leuven (Belgium); Al-Mamgani, Abrahim [Department of Radiation Oncology, Erasmus Medical Center - Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Haustermans, Karin [Radiation Oncology Department, University Hospitals Leuven, Leuven (Belgium); Heemsbergen, Wilma [Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands); Van den Heuvel, Frank [Radiation Oncology Department, University Hospitals Leuven, Leuven (Belgium); Lebesque, Joos V. [Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands)

2012-03-01

Purpose: To study the impact of clinical predisposing factors on rectal normal tissue complication probability modeling using the updated results of the Dutch prostate dose-escalation trial. Methods and Materials: Toxicity data of 512 patients (conformally treated to 68 Gy [n = 284] and 78 Gy [n = 228]) with complete follow-up at 3 years after radiotherapy were studied. Scored end points were rectal bleeding, high stool frequency, and fecal incontinence. Two traditional dose-based models (Lyman-Kutcher-Burman (LKB) and Relative Seriality (RS) and a logistic model were fitted using a maximum likelihood approach. Furthermore, these model fits were improved by including the most significant clinical factors. The area under the receiver operating characteristic curve (AUC) was used to compare the discriminating ability of all fits. Results: Including clinical factors significantly increased the predictive power of the models for all end points. In the optimal LKB, RS, and logistic models for rectal bleeding and fecal incontinence, the first significant (p = 0.011-0.013) clinical factor was 'previous abdominal surgery.' As second significant (p = 0.012-0.016) factor, 'cardiac history' was included in all three rectal bleeding fits, whereas including 'diabetes' was significant (p = 0.039-0.048) in fecal incontinence modeling but only in the LKB and logistic models. High stool frequency fits only benefitted significantly (p = 0.003-0.006) from the inclusion of the baseline toxicity score. For all models rectal bleeding fits had the highest AUC (0.77) where it was 0.63 and 0.68 for high stool frequency and fecal incontinence, respectively. LKB and logistic model fits resulted in similar values for the volume parameter. The steepness parameter was somewhat higher in the logistic model, also resulting in a slightly lower D{sub 50}. Anal wall DVHs were used for fecal incontinence, whereas anorectal wall dose best described the other two endpoints

Evaluating bacterial gene-finding HMM structures as probabilistic logic programs.

Science.gov (United States)

Mørk, Søren; Holmes, Ian

2012-03-01

Probabilistic logic programming offers a powerful way to describe and evaluate structured statistical models. To investigate the practicality of probabilistic logic programming for structure learning in bioinformatics, we undertook a simplified bacterial gene-finding benchmark in PRISM, a probabilistic dialect of Prolog. We evaluate Hidden Markov Model structures for bacterial protein-coding gene potential, including a simple null model structure, three structures based on existing bacterial gene finders and two novel model structures. We test standard versions as well as ADPH length modeling and three-state versions of the five model structures. The models are all represented as probabilistic logic programs and evaluated using the PRISM machine learning system in terms of statistical information criteria and gene-finding prediction accuracy, in two bacterial genomes. Neither of our implementations of the two currently most used model structures are best performing in terms of statistical information criteria or prediction performances, suggesting that better-fitting models might be achievable. The source code of all PRISM models, data and additional scripts are freely available for download at: http://github.com/somork/codonhmm. Supplementary data are available at Bioinformatics online.

An imprecise Dirichlet model for Bayesian analysis of failure data including right-censored observations

International Nuclear Information System (INIS)

Coolen, F.P.A.

1997-01-01

This paper is intended to make researchers in reliability theory aware of a recently introduced Bayesian model with imprecise prior distributions for statistical inference on failure data, that can also be considered as a robust Bayesian model. The model consists of a multinomial distribution with Dirichlet priors, making the approach basically nonparametric. New results for the model are presented, related to right-censored observations, where estimation based on this model is closely related to the product-limit estimator, which is an important statistical method to deal with reliability or survival data including right-censored observations. As for the product-limit estimator, the model considered in this paper aims at not using any information other than that provided by observed data, but our model fits into the robust Bayesian context which has the advantage that all inferences can be based on probabilities or expectations, or bounds for probabilities or expectations. The model uses a finite partition of the time-axis, and as such it is also related to life-tables

Analysis of electronic models for solar cells including energy resolved defect densities

Energy Technology Data Exchange (ETDEWEB)

Glitzky, Annegret

2010-07-01

We introduce an electronic model for solar cells including energy resolved defect densities. The resulting drift-diffusion model corresponds to a generalized van Roosbroeck system with additional source terms coupled with ODEs containing space and energy as parameters for all defect densities. The system has to be considered in heterostructures and with mixed boundary conditions from device simulation. We give a weak formulation of the problem. If the boundary data and the sources are compatible with thermodynamic equilibrium the free energy along solutions decays monotonously. In other cases it may be increasing, but we estimate its growth. We establish boundedness and uniqueness results and prove the existence of a weak solution. This is done by considering a regularized problem, showing its solvability and the boundedness of its solutions independent of the regularization level. (orig.)

Radiologic findings of sacroiliitis : emphasis on MR findings

International Nuclear Information System (INIS)

Yang, Ik; Park, Hai Jung; Lee, Yul; Chung, Soo Young; Park, Jong Ho

1997-01-01

To compare the characteristic MR findings of infectious sacroiliitis (IS) and ankylosing spondylitis (AS). We retrospectively reviewed MR findings in eight patients with IS (pyogenic in six, tuberculosis in two) confirmed by culture and clinical follow-up, and in six with AS by HLA-B27 typing. AA control group of 13 asymptomatic volunteers was formed, and they underwent MRI Findings were analysed for morphology, degree of bone erosion, and adjacent soft tissue change. CT findings of AS in four patients and IS in four were also compared to MR findings. MR characteristics of IS included unilaterality (100%), abnormal cartilage signal intensity (100%), bone marrow change (100%), contrast enhancement (100%), erosion (63%), and soft tissue change (63%). MR findings of AS showed bilaterality (67%), abnormal cartilage signal intensity (80%), bone marrow change (80%), erosion (80%), contrast enhancement (44%) and soft tissue change (10%). CT scan showed bony sclerosis and erosion (86%), and abnormal joint space (71%). MR findings of sacroiliitis were loss of thin zone of a cartilage and erosions on T1-weighted image, and increased signal intensity on T2-weighted image. MRI is regarded as a useful diagnostic method where conventional diagnosis is difficult, and is able to image cartilage abnormalities directly and noninvasively. Significant differences in MR findings between IS and AS were not noted, however

Why Teachers Find It Difficult to Include Students with EBD in Mainstream Classes

Science.gov (United States)

Gidlund, Ulrika

2018-01-01

In Sweden, teachers in mainstream schools show frustration and insecurity about how to organise education for inclusion and diversity. This article contributes to the understanding of how they articulate their view of the advantages and disadvantages of including students with EBD in mainstream classes. To study teachers' understanding, an…

Some findings on zero-inflated and hurdle poisson models for disease mapping.

Science.gov (United States)

Corpas-Burgos, Francisca; García-Donato, Gonzalo; Martinez-Beneito, Miguel A

2018-05-27

Zero excess in the study of geographically referenced mortality data sets has been the focus of considerable attention in the literature, with zero-inflation being the most common procedure to handle this lack of fit. Although hurdle models have also been used in disease mapping studies, their use is more rare. We show in this paper that models using particular treatments of zero excesses are often required for achieving appropriate fits in regular mortality studies since, otherwise, geographical units with low expected counts are oversmoothed. However, as also shown, an indiscriminate treatment of zero excess may be unnecessary and has a problematic implementation. In this regard, we find that naive zero-inflation and hurdle models, without an explicit modeling of the probabilities of zeroes, do not fix zero excesses problems well enough and are clearly unsatisfactory. Results sharply suggest the need for an explicit modeling of the probabilities that should vary across areal units. Unfortunately, these more flexible modeling strategies can easily lead to improper posterior distributions as we prove in several theoretical results. Those procedures have been repeatedly used in the disease mapping literature, and one should bear these issues in mind in order to propose valid models. We finally propose several valid modeling alternatives according to the results mentioned that are suitable for fitting zero excesses. We show that those proposals fix zero excesses problems and correct the mentioned oversmoothing of risks in low populated units depicting geographic patterns more suited to the data. Copyright © 2018 John Wiley & Sons, Ltd.

Mathematical Model of Two Phase Flow in Natural Draft Wet-Cooling Tower Including Flue Gas Injection

Directory of Open Access Journals (Sweden)

Hyhlík Tomáš

2016-01-01

Full Text Available The previously developed model of natural draft wet-cooling tower flow, heat and mass transfer is extended to be able to take into account the flow of supersaturated moist air. The two phase flow model is based on void fraction of gas phase which is included in the governing equations. Homogeneous equilibrium model, where the two phases are well mixed and have the same velocity, is used. The effect of flue gas injection is included into the developed mathematical model by using source terms in governing equations and by using momentum flux coefficient and kinetic energy flux coefficient. Heat and mass transfer in the fill zone is described by the system of ordinary differential equations, where the mass transfer is represented by measured fill Merkel number and heat transfer is calculated using prescribed Lewis factor.

Finding identifiable parameter combinations in nonlinear ODE models and the rational reparameterization of their input-output equations.

Science.gov (United States)

Meshkat, Nicolette; Anderson, Chris; Distefano, Joseph J

2011-09-01

When examining the structural identifiability properties of dynamic system models, some parameters can take on an infinite number of values and yet yield identical input-output data. These parameters and the model are then said to be unidentifiable. Finding identifiable combinations of parameters with which to reparameterize the model provides a means for quantitatively analyzing the model and computing solutions in terms of the combinations. In this paper, we revisit and explore the properties of an algorithm for finding identifiable parameter combinations using Gröbner Bases and prove useful theoretical properties of these parameter combinations. We prove a set of M algebraically independent identifiable parameter combinations can be found using this algorithm and that there exists a unique rational reparameterization of the input-output equations over these parameter combinations. We also demonstrate application of the procedure to a nonlinear biomodel. Copyright © 2011 Elsevier Inc. All rights reserved.

PumpKin: A tool to find principal pathways in plasma chemical models

Science.gov (United States)

Markosyan, A. H.; Luque, A.; Gordillo-Vázquez, F. J.; Ebert, U.

2014-10-01

PumpKin is a software package to find all principal pathways, i.e. the dominant reaction sequences, in chemical reaction systems. Although many tools are available to integrate numerically arbitrarily complex chemical reaction systems, few tools exist in order to analyze the results and interpret them in relatively simple terms. In particular, due to the large disparity in the lifetimes of the interacting components, it is often useful to group reactions into pathways that recycle the fastest species. This allows a researcher to focus on the slow chemical dynamics, eliminating the shortest timescales. Based on the algorithm described by Lehmann (2004), PumpKin automates the process of finding such pathways, allowing the user to analyze complex kinetics and to understand the consumption and production of a certain species of interest. We designed PumpKin with an emphasis on plasma chemical systems but it can also be applied to atmospheric modeling and to industrial applications such as plasma medicine and plasma-assisted combustion.

Fluid-structure interaction including volumetric coupling with homogenised subdomains for modeling respiratory mechanics.

Science.gov (United States)

Yoshihara, Lena; Roth, Christian J; Wall, Wolfgang A

2017-04-01

In this article, a novel approach is presented for combining standard fluid-structure interaction with additional volumetric constraints to model fluid flow into and from homogenised solid domains. The proposed algorithm is particularly interesting for investigations in the field of respiratory mechanics as it enables the mutual coupling of airflow in the conducting part and local tissue deformation in the respiratory part of the lung by means of a volume constraint. In combination with a classical monolithic fluid-structure interaction approach, a comprehensive model of the human lung can be established that will be useful to gain new insights into respiratory mechanics in health and disease. To illustrate the validity and versatility of the novel approach, three numerical examples including a patient-specific lung model are presented. The proposed algorithm proves its capability of computing clinically relevant airflow distribution and tissue strain data at a level of detail that is not yet achievable, neither with current imaging techniques nor with existing computational models. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Towards ligand docking including explicit interface water molecules.

Directory of Open Access Journals (Sweden)

Gordon Lemmon

Full Text Available Small molecule docking predicts the interaction of a small molecule ligand with a protein at atomic-detail accuracy including position and conformation the ligand but also conformational changes of the protein upon ligand binding. While successful in the majority of cases, docking algorithms including RosettaLigand fail in some cases to predict the correct protein/ligand complex structure. In this study we show that simultaneous docking of explicit interface water molecules greatly improves Rosetta's ability to distinguish correct from incorrect ligand poses. This result holds true for both protein-centric water docking wherein waters are located relative to the protein binding site and ligand-centric water docking wherein waters move with the ligand during docking. Protein-centric docking is used to model 99 HIV-1 protease/protease inhibitor structures. We find protease inhibitor placement improving at a ratio of 9:1 when one critical interface water molecule is included in the docking simulation. Ligand-centric docking is applied to 341 structures from the CSAR benchmark of diverse protein/ligand complexes [1]. Across this diverse dataset we see up to 56% recovery of failed docking studies, when waters are included in the docking simulation.

Contextual Factors for Finding Similar Experts

DEFF Research Database (Denmark)

Hofmann, Katja; Balog, Krisztian; Bogers, Toine

2010-01-01

-seeking models, are rarely taken into account. In this article, we extend content-based expert-finding approaches with contextual factors that have been found to influence human expert finding. We focus on a task of science communicators in a knowledge-intensive environment, the task of finding similar experts......, given an example expert. Our approach combines expertise-seeking and retrieval research. First, we conduct a user study to identify contextual factors that may play a role in the studied task and environment. Then, we design expert retrieval models to capture these factors. We combine these with content......-based retrieval models and evaluate them in a retrieval experiment. Our main finding is that while content-based features are the most important, human participants also take contextual factors into account, such as media experience and organizational structure. We develop two principled ways of modeling...

Global stability for infectious disease models that include immigration of infected individuals and delay in the incidence

Directory of Open Access Journals (Sweden)

Chelsea Uggenti

2018-03-01

Full Text Available We begin with a detailed study of a delayed SI model of disease transmission with immigration into both classes. The incidence function allows for a nonlinear dependence on the infected population, including mass action and saturating incidence as special cases. Due to the immigration of infectives, there is no disease-free equilibrium and hence no basic reproduction number. We show there is a unique endemic equilibrium and that this equilibrium is globally asymptotically stable for all parameter values. The results include vector-style delay and latency-style delay. Next, we show that previous global stability results for an SEI model and an SVI model that include immigration of infectives and non-linear incidence but not delay can be extended to systems with vector-style delay and latency-style delay.

Zγ production at NNLO including anomalous couplings

Science.gov (United States)

Campbell, John M.; Neumann, Tobias; Williams, Ciaran

2017-11-01

In this paper we present a next-to-next-to-leading order (NNLO) QCD calculation of the processes pp → l + l -γ and pp\\to ν \\overline{ν}γ that we have implemented in MCFM. Our calculation includes QCD corrections at NNLO both for the Standard Model (SM) and additionally in the presence of Zγγ and ZZγ anomalous couplings. We compare our implementation, obtained using the jettiness slicing approach, with a previous SM calculation and find broad agreement. Focusing on the sensitivity of our results to the slicing parameter, we show that using our setup we are able to compute NNLO cross sections with numerical uncertainties of about 0.1%, which is small compared to residual scale uncertainties of a few percent. We study potential improvements using two different jettiness definitions and the inclusion of power corrections. At √{s}=13 TeV we present phenomenological results and consider Zγ as a background to H → Zγ production. We find that, with typical cuts, the inclusion of NNLO corrections represents a small effect and loosens the extraction of limits on anomalous couplings by about 10%.

Modeling of the dynamics of wind to power conversion including high wind speed behavior

DEFF Research Database (Denmark)

Litong-Palima, Marisciel; Bjerge, Martin Huus; Cutululis, Nicolaos Antonio

2016-01-01

This paper proposes and validates an efficient, generic and computationally simple dynamic model for the conversion of the wind speed at hub height into the electrical power by a wind turbine. This proposed wind turbine model was developed as a first step to simulate wind power time series...... for power system studies. This paper focuses on describing and validating the single wind turbine model, and is therefore neither describing wind speed modeling nor aggregation of contributions from a whole wind farm or a power system area. The state-of-the-art is to use static power curves for the purpose...... of power system studies, but the idea of the proposed wind turbine model is to include the main dynamic effects in order to have a better representation of the fluctuations in the output power and of the fast power ramping especially because of high wind speed shutdowns of the wind turbine. The high wind...

Examples of Video to Communicate Scientific Findings to Non-Scientists-Bayesian Ecological Modeling

Science.gov (United States)

Moorman, M.; Harned, D. A.; Cuffney, T.; Qian, S.

2011-12-01

The U.S Geological Survey (USGS) National Water-Quality Assessment Program (NAWQA) provides information about (1) water-quality conditions and how those conditions vary locally, regionally, and nationally, (2) water-quality trends, and (3) factors that affect those conditions. As part of the NAWQA Program, the Effects of Urbanization on Stream Ecosystems (EUSE) study examined the vulnerability and resilience of streams to urbanization. Completion of the EUSE study has resulted in over 20 scientific publications. Video podcasts are being used in addition to these publications to communicate the relevance of these scientific findings to more general audiences such as resource managers, educational groups, public officials, and the general public. An example of one of the podcasts is a film about the results of modeling the effects urbanization on stream ecology. The film describes some of the results of the EUSE ecological modeling effort and the advantages of the Bayesian and multi-level statistical modeling approaches, while relating the science to fly fishing. The complex scientific discussion combined with the lighter, more popular activity of fly fishing leads to an entertaining forum while educating viewers about a complex topic. This approach is intended to represent the scientists as interesting people with diverse interests. Video can be an effective scientific communication tool for presenting scientific findings to a broad audience. The film is available for access from the EUSE website (http://water.usgs.gov/nawqa/urban/html/podcasts.html). Additional films are planned to be released in 2012 on other USGS project results and programs.

Modelling step-families: exploratory findings.

Science.gov (United States)

Bartlema, J

1988-01-01

"A combined macro-micro model is applied to a population similar to that forecast for 2035 in the Netherlands in order to simulate the effect on kinship networks of a mating system of serial monogamy. The importance of incorporating a parameter for the degree of concentration of childbearing over the female population is emphasized. The inputs to the model are vectors of fertility rates by age of mother, and by age of father, a matrix of first-marriage rates by age of both partners (used in the macro-analytical expressions), and two parameters H and S (used in the micro-simulation phase). The output is a data base of hypothetical individuals, whose records contain identification number, age, sex, and the identification numbers of their relatives." (SUMMARY IN FRE) excerpt

Importance of including small-scale tile drain discharge in the calibration of a coupled groundwater-surface water catchment model

DEFF Research Database (Denmark)

Hansen, Anne Lausten; Refsgaard, Jens Christian; Christensen, Britt Stenhøj Baun

2013-01-01

the catchment. In this study, a coupled groundwater-surface water model based on the MIKE SHE code was developed for the 4.7 km2 Lillebæk catchment in Denmark, where tile drain flow is a major contributor to the stream discharge. The catchment model was calibrated in several steps by incrementally including...... the observation data into the calibration to see the effect on model performance of including diverse data types, especially tile drain discharge. For the Lillebæk catchment, measurements of hydraulic head, daily stream discharge, and daily tile drain discharge from five small (1–4 ha) drainage areas exist....... The results showed that including tile drain data in the calibration of the catchment model improved its general performance for hydraulic heads and stream discharges. However, the model failed to correctly describe the local-scale dynamics of the tile drain discharges, and, furthermore, including the drain...

Development of realistic concrete models including scaling effects

International Nuclear Information System (INIS)

Carpinteri, A.

1989-09-01

Progressive cracking in structural elements of concrete is considered. Two simple models are applied, which, even though different, lead to similar predictions for the fracture behaviour. Both Virtual Crack Propagation Model and Cohesive Limit Analysis (Section 2), show a trend towards brittle behaviour and catastrophical events for large structural sizes. A numerical Cohesive Crack Model is proposed (Section 3) to describe strain softening and strain localization in concrete. Such a model is able to predict the size effects of fracture mechanics accurately. Whereas for Mode I, only untieing of the finite element nodes is applied to simulate crack growth, for Mixed Mode a topological variation is required at each step (Section 4). In the case of the four point shear specimen, the load vs. deflection diagrams reveal snap-back instability for large sizes. By increasing the specimen sizes, such instability tends to reproduce the classical LEFM instability. Remarkable size effects are theoretically predicted and experimentally confirmed also for reinforced concrete (Section 5). The brittleness of the flexural members increases by increasing size and/or decreasing steel content. On the basis of these results, the empirical code rules regarding the minimum amount of reinforcement could be considerably revised

Extending Galactic Habitable Zone Modeling to Include the Emergence of Intelligent Life.

Science.gov (United States)

Morrison, Ian S; Gowanlock, Michael G

2015-08-01

Previous studies of the galactic habitable zone have been concerned with identifying those regions of the Galaxy that may favor the emergence of complex life. A planet is deemed habitable if it meets a set of assumed criteria for supporting the emergence of such complex life. In this work, we extend the assessment of habitability to consider the potential for life to further evolve to the point of intelligence--termed the propensity for the emergence of intelligent life, φI. We assume φI is strongly influenced by the time durations available for evolutionary processes to proceed undisturbed by the sterilizing effects of nearby supernovae. The times between supernova events provide windows of opportunity for the evolution of intelligence. We developed a model that allows us to analyze these window times to generate a metric for φI, and we examine here the spatial and temporal variation of this metric. Even under the assumption that long time durations are required between sterilizations to allow for the emergence of intelligence, our model suggests that the inner Galaxy provides the greatest number of opportunities for intelligence to arise. This is due to the substantially higher number density of habitable planets in this region, which outweighs the effects of a higher supernova rate in the region. Our model also shows that φI is increasing with time. Intelligent life emerged at approximately the present time at Earth's galactocentric radius, but a similar level of evolutionary opportunity was available in the inner Galaxy more than 2 Gyr ago. Our findings suggest that the inner Galaxy should logically be a prime target region for searches for extraterrestrial intelligence and that any civilizations that may have emerged there are potentially much older than our own.

Relationship between Urinary N-Desmethyl-Acetamiprid and Typical Symptoms including Neurological Findings: A Prevalence Case-Control Study.

Directory of Open Access Journals (Sweden)

Jemima Tiwaa Marfo

Full Text Available Neonicotinoid insecticides are nicotinic acetylcholine receptor agonists used worldwide. Their environmental health effects including neurotoxicity are of concern. We previously determined a metabolite of acetamiprid, N-desmethyl-acetamiprid in the urine of a patient, who exhibited some typical symptoms including neurological findings. We sought to investigate the association between urinary N-desmethyl-acetamiprid and the symptoms by a prevalence case-control study. Spot urine samples were collected from 35 symptomatic patients of unknown origin and 50 non-symptomatic volunteers (non-symptomatic group, NSG, 4-87 year-old. Patients with recent memory loss, finger tremor, and more than five of six symptoms (headache, general fatigue, palpitation/chest pain, abdominal pain, muscle pain/weakness/spasm, and cough were in the typical symptomatic group (TSG, n = 19, 5-69 year-old; the rest were in the atypical symptomatic group (ASG, n = 16, 5-78 year-old. N-desmethyl-acetamiprid and six neonicotinoids in the urine were quantified by liquid chromatography-tandem mass spectrometry. The detection of N-desmethyl-acetamiprid was the most frequent and highest in TSG (47.4%, 6.0 ppb (frequency, maximum, followed by in ASG (12.5%, 4.4 ppb and in NSG (6.0%, 2.2 ppb, however acetamiprid was not detected. Thiamethoxam was detected in TSG (31.6%, 1.4 ppb, in ASG (6.3%, 1.9 ppb, but not in NSG. Nitenpyram was detected in TSG (10.5%, 1.2 ppb, in ASG (6.3%, not quantified and in NSG (2.0%, not quantified. Clothianidin was only detected in ASG (6.3%, not quantified, and in NSG (2.0%, 1.6 ppb. Thiacloprid was detected in ASG (6.3%, 0.1 ppb. The cases in TSG with detection of N-desmethyl-acetamiprid and thiamethoxam were aged 5 to 62 years and 13 to 62 years, respectively. Detection of N-desmethyl-acetamiprid was associated with increased prevalence of the symptoms (odds ratio: 14, 95% confidence interval: 3.5-57. Urinary N-desmethyl-acetamiprid can be used as a

Major KEEP Findings, 1971 - 1975.

Science.gov (United States)

Kamehameha Schools, Honolulu, HI. Kamehameha Early Education Project.

This report lists the 34 major research findings from the Kamehameha Early Education Program (KEEP) for the years 1971-1975. Each finding is accompanied by a listing of KEEP technical reports and working papers which contain information relevant to that finding. Included among areas covered in the findings are: (1) student motivation, (2) teacher…

Hepatic encephalopathy. Imaging Findings

International Nuclear Information System (INIS)

Carrillo, Maria Claudia; Bermudez Munoz, Sonia; J Morillo, Anibal

2007-01-01

Hepatic encephalopathy occurs in patients with chronic hepatic insufficiency and can produce abnormalities in the central nervous system, which can be observed in MRI studies. Traditionally, these imaging findings include symmetrical hyper intensities in T1-weighted sequences in the basal ganglia (mainly globus pallidus), involving also the substantia nigra, mesencephalic tegmentum, frontal and occipital cortex. These areas appear of normal intensity in T2-weighted imaging sequences. Other entities that can lead to similar findings include manganese intoxication and type-1 neurofibromatosis. Currently, with the advent of MR spectroscopy, abnormalities in patients with clinical and subclinical hepatic encephalopathy have been described. After hepatic transplantation, hyper intensities of the basal ganglia and the MR spectroscopic findings may disappear within 3 months to 1 year, suggesting a functional, more than a structural damage. This article will demonstrate the MR findings of patients with hepatic encephalopathy due to chronic hepatic insufficiency.

Varied autopsy findings in five treated patients with Gaucher disease and parkinsonism include the absence of Gaucher cells.

Science.gov (United States)

Monestime, Gianina; Borger, Daniel K; Kim, Jenny; Lopez, Grisel; Allgaeuer, Michael; Jain, Dhanpat; Vortmeyer, Alexander; Wang, Hao-Wei; Sidransky, Ellen

2016-05-01

Enzyme replacement therapy is standard of care for patients with Gaucher disease, as it significantly improves skeletal, visceral, and hematological symptoms. Few pathological studies have documented the extent of pathological findings in treated patients. Autopsy findings in five treated patients, who ultimately developed parkinsonism, ranged from the complete absence of Gaucher pathology to extensive involvement of multiple tissues, without correlation to age, genotype, spleen status, or dose/duration of therapy. Additional autopsies may elucidate modifiers and biomarkers contributing to disease burden and response to therapy. Published by Elsevier Inc.

MHD model including small-scale perturbations in a plasma with temperature variations

International Nuclear Information System (INIS)

Kuvshinov, B.N.; Mikhailovskii, A.B.

1996-01-01

The possibility is studied of using a hydrodynamic model to describe a magnetized plasma with density and temperature variations on scales that are arbitrary with respect to the ion Larmor radius. It is shown that the inertial component of the transverse ion thermal flux should be taken into account. This component is found from the collisionless kinetic equation. It can also be obtained from the equations of the Grad type. A set of two-dimensional hydrodynamic equations for ions is obtained with this component taken into account. These equations are used to derive model hydrodynamic expressions for the density and temperature variations. It is shown that, for large-scale perturbations (when the wavelengths are longer than the ion Larmor radius), the expressions derived coincide with the corresponding kinetic expressions and, for perturbations on sub-Larmor scales (when the wavelengths are shorter than the Larmor radius), they agree qualitatively. Hydrodynamic dispersion relations are derived for several types of drift waves with arbitrary wavenumbers. The range of applicability of the MHD model is determined from a comparison of these dispersion relations with the kinetic ones. It is noted that, on the basis of results obtained, drift effects can be included in numerical MHD codes for studying plasma instabilities in high-temperature regimes in tokamaks

Mathematical multi-scale model of the cardiovascular system including mitral valve dynamics. Application to ischemic mitral insufficiency

Directory of Open Access Journals (Sweden)

Moonen Marie

2011-09-01

Full Text Available Abstract Background Valve dysfunction is a common cardiovascular pathology. Despite significant clinical research, there is little formal study of how valve dysfunction affects overall circulatory dynamics. Validated models would offer the ability to better understand these dynamics and thus optimize diagnosis, as well as surgical and other interventions. Methods A cardiovascular and circulatory system (CVS model has already been validated in silico, and in several animal model studies. It accounts for valve dynamics using Heaviside functions to simulate a physiologically accurate "open on pressure, close on flow" law. However, it does not consider real-time valve opening dynamics and therefore does not fully capture valve dysfunction, particularly where the dysfunction involves partial closure. This research describes an updated version of this previous closed-loop CVS model that includes the progressive opening of the mitral valve, and is defined over the full cardiac cycle. Results Simulations of the cardiovascular system with healthy mitral valve are performed, and, the global hemodynamic behaviour is studied compared with previously validated results. The error between resulting pressure-volume (PV loops of already validated CVS model and the new CVS model that includes the progressive opening of the mitral valve is assessed and remains within typical measurement error and variability. Simulations of ischemic mitral insufficiency are also performed. Pressure-Volume loops, transmitral flow evolution and mitral valve aperture area evolution follow reported measurements in shape, amplitude and trends. Conclusions The resulting cardiovascular system model including mitral valve dynamics provides a foundation for clinical validation and the study of valvular dysfunction in vivo. The overall models and results could readily be generalised to other cardiac valves.

Nonlocal continuum-based modeling of breathing mode of nanowires including surface stress and surface inertia effects

Science.gov (United States)

Ghavanloo, Esmaeal; Fazelzadeh, S. Ahmad; Rafii-Tabar, Hashem

2014-05-01

Nonlocal and surface effects significantly influence the mechanical response of nanomaterials and nanostructures. In this work, the breathing mode of a circular nanowire is studied on the basis of the nonlocal continuum model. Both the surface elastic properties and surface inertia effect are included. Nanowires can be modeled as long cylindrical solid objects. The classical model is reformulated using the nonlocal differential constitutive relations of Eringen and Gurtin-Murdoch surface continuum elasticity formalism. A new frequency equation for the breathing mode of nanowires, including small scale effect, surface stress and surface inertia is presented by employing the Bessel functions. Numerical results are computed, and are compared to confirm the validity and accuracy of the proposed method. Furthermore, the model is used to elucidate the effect of nonlocal parameter, the surface stress, the surface inertia and the nanowire orientation on the breathing mode of several types of nanowires with size ranging from 0.5 to 4 nm. Our results reveal that the combined surface and small scale effects are significant for nanowires with diameter smaller than 4 nm.

Nonlocal continuum-based modeling of breathing mode of nanowires including surface stress and surface inertia effects

International Nuclear Information System (INIS)

Ghavanloo, Esmaeal; Fazelzadeh, S. Ahmad; Rafii-Tabar, Hashem

2014-01-01

Nonlocal and surface effects significantly influence the mechanical response of nanomaterials and nanostructures. In this work, the breathing mode of a circular nanowire is studied on the basis of the nonlocal continuum model. Both the surface elastic properties and surface inertia effect are included. Nanowires can be modeled as long cylindrical solid objects. The classical model is reformulated using the nonlocal differential constitutive relations of Eringen and Gurtin–Murdoch surface continuum elasticity formalism. A new frequency equation for the breathing mode of nanowires, including small scale effect, surface stress and surface inertia is presented by employing the Bessel functions. Numerical results are computed, and are compared to confirm the validity and accuracy of the proposed method. Furthermore, the model is used to elucidate the effect of nonlocal parameter, the surface stress, the surface inertia and the nanowire orientation on the breathing mode of several types of nanowires with size ranging from 0.5 to 4 nm. Our results reveal that the combined surface and small scale effects are significant for nanowires with diameter smaller than 4 nm.

Nonlocal continuum-based modeling of breathing mode of nanowires including surface stress and surface inertia effects

Energy Technology Data Exchange (ETDEWEB)

Ghavanloo, Esmaeal, E-mail: ghavanloo@shirazu.ac.ir [School of Mechanical Engineering, Shiraz University, Shiraz 71963-16548 (Iran, Islamic Republic of); Fazelzadeh, S. Ahmad [School of Mechanical Engineering, Shiraz University, Shiraz 71963-16548 (Iran, Islamic Republic of); Rafii-Tabar, Hashem [Department of Medical Physics and Biomedical Engineering, Research Center for Medical Nanotechnology and Tissue Engineering, Shahid Beheshti University of Medical Sciences, Evin, Tehran (Iran, Islamic Republic of); Computational Physical Sciences Research Laboratory, School of Nano-Science, Institute for Research in Fundamental Sciences (IPM), Tehran (Iran, Islamic Republic of)

2014-05-01

Nonlocal and surface effects significantly influence the mechanical response of nanomaterials and nanostructures. In this work, the breathing mode of a circular nanowire is studied on the basis of the nonlocal continuum model. Both the surface elastic properties and surface inertia effect are included. Nanowires can be modeled as long cylindrical solid objects. The classical model is reformulated using the nonlocal differential constitutive relations of Eringen and Gurtin–Murdoch surface continuum elasticity formalism. A new frequency equation for the breathing mode of nanowires, including small scale effect, surface stress and surface inertia is presented by employing the Bessel functions. Numerical results are computed, and are compared to confirm the validity and accuracy of the proposed method. Furthermore, the model is used to elucidate the effect of nonlocal parameter, the surface stress, the surface inertia and the nanowire orientation on the breathing mode of several types of nanowires with size ranging from 0.5 to 4 nm. Our results reveal that the combined surface and small scale effects are significant for nanowires with diameter smaller than 4 nm.

Influence of structural parameter included in nonlocal rock mass model on stress concentration around circular tunnel

Science.gov (United States)

Lavrikov, SV; Mikenina, OA; Revuzhenko, AF

2018-03-01

A model of elastic body, including local curvature of elementary volume, is matched with a nonlocal model with a linear structural parameter in the differential approximation. The problem on deformation of rock mass around a circular cross section tunnel is solved numerically. The contours of the calculated stresses are plotted. It is shown that inclusion of local bends in the model results in expansion of influence zone of the tunnel and reduces stress concentration factor at the tunnel boundary.

Model for safety reports including descriptive examples; Mall foer saekerhetsrapporter med beskrivande exempel

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-12-01

Several safety reports will be produced in the process of planning and constructing the system for disposal of high-level radioactive waste in Sweden. The present report gives a model, with detailed examples, of how these reports should be organized and what steps they should include. In the near future safety reports will deal with the encapsulation plant and the repository. Later reports will treat operation of the handling systems and the repository.

Modeling of Pem Fuel Cell Systems Including Controls and Reforming Effects for Hybrid Automotive Applications

National Research Council Canada - National Science Library

Boettner, Daisie

2001-01-01

.... This study develops models for a stand-alone Proton Exchange Membrane (PEM) fuel cell stack, a direct-hydrogen fuel cell system including auxiliaries, and a methanol reforming fuel cell system for integration into a vehicle performance simulator...

An Integrated Biochemistry Laboratory, Including Molecular Modeling

Science.gov (United States)

Hall, Adele J. Wolfson Mona L.; Branham, Thomas R.

1996-11-01

) experience with methods of protein purification; (iii) incorporation of appropriate controls into experiments; (iv) use of basic statistics in data analysis; (v) writing papers and grant proposals in accepted scientific style; (vi) peer review; (vii) oral presentation of results and proposals; and (viii) introduction to molecular modeling. Figure 1 illustrates the modular nature of the lab curriculum. Elements from each of the exercises can be separated and treated as stand-alone exercises, or combined into short or long projects. We have been able to offer the opportunity to use sophisticated molecular modeling in the final module through funding from an NSF-ILI grant. However, many of the benefits of the research proposal can be achieved with other computer programs, or even by literature survey alone. Figure 1.Design of project-based biochemistry laboratory. Modules (projects, or portions of projects) are indicated as boxes. Each of these can be treated independently, or used as part of a larger project. Solid lines indicate some suggested paths from one module to the next. The skills and knowledge required for protein purification and design are developed in three units: (i) an introduction to critical assays needed to monitor degree of purification, including an evaluation of assay parameters; (ii) partial purification by ion-exchange techniques; and (iii) preparation of a grant proposal on protein design by mutagenesis. Brief descriptions of each of these units follow, with experimental details of each project at the end of this paper. Assays for Lysozyme Activity and Protein Concentration (4 weeks) The assays mastered during the first unit are a necessary tool for determining the purity of the enzyme during the second unit on purification by ion exchange. These assays allow an introduction to the concept of specific activity (units of enzyme activity per milligram of total protein) as a measure of purity. In this first sequence, students learn a turbidimetric assay

An evaluation of accounting-based finding costs as efficiency measures for oil and gas exploration

International Nuclear Information System (INIS)

Boynton, C.E. IV; Boone, J.P.

1994-08-01

The authors have operationalized firm-specific exploration efficiency as the difference between a firm-specific intercept estimated in a fixed-effects panel data Cobb-Douglas production frontier model and the maximum firm-specific intercept estimated in that model. The production model was estimated during two different time periods, 1982--1985 and 1989--1992, allowing efficiency to vary intertemporally. This efficiency estimate served as a benchmark against which they compared various measures of inverse finding costs. They assumed that the degree of association with an efficiency benchmark is an important attribute of any finding cost measure and that, further, the degree of association may be used as a metric for choosing between alternative finding cost measures. Accordingly, they evaluated the cross-sectional statistical association between estimated efficiency and alternative inverse finding cost measures. They discovered that the inverse finding cost measure that exhibited the strongest association with efficiency during the two time periods was a three-year moving-average finding cost which included exploration plus development expenditures as costs and reserve extensions and additions plus revisions as the units added

An evaluation of accounting-based finding costs as efficiency measures for oil and gas exploration

Energy Technology Data Exchange (ETDEWEB)

Boynton, C.E. IV; Boone, J.P.

1994-08-01

The authors have operationalized firm-specific exploration efficiency as the difference between a firm-specific intercept estimated in a fixed-effects panel data Cobb-Douglas production frontier model and the maximum firm-specific intercept estimated in that model. The production model was estimated during two different time periods, 1982--1985 and 1989--1992, allowing efficiency to vary intertemporally. This efficiency estimate served as a benchmark against which they compared various measures of inverse finding costs. They assumed that the degree of association with an efficiency benchmark is an important attribute of any finding cost measure and that, further, the degree of association may be used as a metric for choosing between alternative finding cost measures. Accordingly, they evaluated the cross-sectional statistical association between estimated efficiency and alternative inverse finding cost measures. They discovered that the inverse finding cost measure that exhibited the strongest association with efficiency during the two time periods was a three-year moving-average finding cost which included exploration plus development expenditures as costs and reserve extensions and additions plus revisions as the units added.

Low finding costs calculated in Mississippi's Tuscaloosa, Frio

International Nuclear Information System (INIS)

Dowty, S.G.; Moody, J.S.

1992-01-01

This paper reports on a recent study conducted by the Mississippi Office of Geology which examined oil and gas finding costs in southwestern Mississippi for the period from 1986 through 1990. The formations of interest were the Upper Cretaceous Lower Tuscaloosa formation and the Oligocene Frio formation. The model incorporated the following financial considerations for exploratory activity: seismic data acquisition, geologic expenses, leasing and legal fees, and drilling costs. Average drilling and completion costs were also assigned to the development wells. The finding cost formula divided the total exploration and development costs by the recoverable reserves. Reserves were multiplied by a 75% net revenue for the Tuscaloosa and 80% for the Frio leases to account for royalty interests and severance taxes. No field operating expenses were included

Including the effects of filamentous bulking sludge during the simulation of wastewater treatment plants using a risk assessment model

DEFF Research Database (Denmark)

Flores Alsina, Xavier; Comas, J.; Rodriquez-Roda, I.

2009-01-01

The main objective of this paper is to demonstrate how including the occurrence of filamentous bulking sludge in a secondary clarifier model will affect the predicted process performance during the simulation of WWTPs. The IWA Benchmark Simulation Model No. 2 (BSM2) is hereby used as a simulation...... are automatically changed during the simulation by modifying the settling model parameters to mimic the effect of growth of filamentous bacteria. The simulation results demonstrate that including effects of filamentous bulking in the secondary clarifier model results in a more realistic plant performance...

Include dispersion in quantum chemical modeling of enzymatic reactions: the case of isoaspartyl dipeptidase.

Science.gov (United States)

Zhang, Hai-Mei; Chen, Shi-Lu

2015-06-09

The lack of dispersion in the B3LYP functional has been proposed to be the main origin of big errors in quantum chemical modeling of a few enzymes and transition metal complexes. In this work, the essential dispersion effects that affect quantum chemical modeling are investigated. With binuclear zinc isoaspartyl dipeptidase (IAD) as an example, dispersion is included in the modeling of enzymatic reactions by two different procedures, i.e., (i) geometry optimizations followed by single-point calculations of dispersion (approach I) and (ii) the inclusion of dispersion throughout geometry optimization and energy evaluation (approach II). Based on a 169-atom chemical model, the calculations show a qualitative consistency between approaches I and II in energetics and most key geometries, demonstrating that both approaches are available with the latter preferential since both geometry and energy are dispersion-corrected in approach II. When a smaller model without Arg233 (147 atoms) was used, an inconsistency was observed, indicating that the missing dispersion interactions are essentially responsible for determining equilibrium geometries. Other technical issues and mechanistic characteristics of IAD are also discussed, in particular with respect to the effects of Arg233.

Mean field diffusion models for precipitation in crystalline GaAs including surface tension and bulk stresses

Energy Technology Data Exchange (ETDEWEB)

Dreyer, Wolfgang [Weierstrass-Institut fuer Angewandte Analysis und Stochastik (WIAS) im Forschungsverbund Berlin e.V. (Germany); Kimmerle, Sven-Joachim [Humboldt-Univ. Berlin (Germany). Dept. of Mathematics

2009-07-01

Based on a thermodynamically consistent model for precipitation in gallium arsenide crystals including surface tension and bulk stresses by Dreyer and Duderstadt, we propose different mathematical models to describe the size evolution of liquid droplets in a crystalline solid. The first class of models treats the diffusion-controlled regime of interface motion, while the second class is concerned with the interface-controlled regime of interface motion. Our models take care of conservation of mass and substance. We consider homogenised models, where different length scales of the experimental situation have been exploited in order to simplify the equations. These homogenised models generalise the well-known Lifshitz-Slyozov-Wagner model for Ostwald ripening. Mean field models capture the main properties of our system and are well adapted for numerics and further analysis. Numerical evidence suggests in which case which one of the two regimes might be appropriate to the experimental situation. (orig.)

Femtosecond-laser induced dynamics of CO on Ru(0001): Deep insights from a hot-electron friction model including surface motion

Science.gov (United States)

Scholz, Robert; Floß, Gereon; Saalfrank, Peter; Füchsel, Gernot; Lončarić, Ivor; Juaristi, J. I.

2016-10-01

A Langevin model accounting for all six molecular degrees of freedom is applied to femtosecond-laser induced, hot-electron driven dynamics of Ru(0001)(2 ×2 ):CO. In our molecular dynamics with electronic friction approach, a recently developed potential energy surface based on gradient-corrected density functional theory accounting for van der Waals interactions is adopted. Electronic friction due to the coupling of molecular degrees of freedom to electron-hole pairs in the metal are included via a local density friction approximation, and surface phonons by a generalized Langevin oscillator model. The action of ultrashort laser pulses enters through a substrate-mediated, hot-electron mechanism via a time-dependent electronic temperature (derived from a two-temperature model), causing random forces acting on the molecule. The model is applied to laser induced lateral diffusion of CO on the surface, "hot adsorbate" formation, and laser induced desorption. Reaction probabilities are strongly enhanced compared to purely thermal processes, both for diffusion and desorption. Reaction yields depend in a characteristic (nonlinear) fashion on the applied laser fluence, as well as branching ratios for various reaction channels. Computed two-pulse correlation traces for desorption and other indicators suggest that aside from electron-hole pairs, phonons play a non-negligible role for laser induced dynamics in this system, acting on a surprisingly short time scale. Our simulations on precomputed potentials allow for good statistics and the treatment of long-time dynamics (300 ps), giving insight into this system which hitherto has not been reached. We find generally good agreement with experimental data where available and make predictions in addition. A recently proposed laser induced population of physisorbed precursor states could not be observed with the present low-coverage model.

Internet addiction neuroscientific approaches and therapeutical implications including smartphone addiction

CERN Document Server

Reuter, Martin

2017-01-01

The second edition of this successful book provides further and in-depth insight into theoretical models dealing with Internet addiction, as well as includes new therapeutical approaches. The editors also broach the emerging topic of smartphone addiction. This book combines a scholarly introduction with state-of-the-art research in the characterization of Internet addiction. It is intended for a broad audience including scientists, students and practitioners. The first part of the book contains an introduction to Internet addiction and their pathogenesis. The second part of the book is dedicated to an in-depth review of neuroscientific findings which cover studies using a variety of biological techniques including brain imaging and molecular genetics. The third part of the book focuses on therapeutic interventions for Internet addiction. The fourth part of the present book is an extension to the first edition and deals with a new emerging potential disorder related to Internet addiction – smartphone addicti...

Habitability of super-Earth planets around other suns: models including Red Giant Branch evolution.

Science.gov (United States)

von Bloh, W; Cuntz, M; Schröder, K-P; Bounama, C; Franck, S

2009-01-01

The unexpected diversity of exoplanets includes a growing number of super-Earth planets, i.e., exoplanets with masses of up to several Earth masses and a similar chemical and mineralogical composition as Earth. We present a thermal evolution model for a 10 Earth-mass planet orbiting a star like the Sun. Our model is based on the integrated system approach, which describes the photosynthetic biomass production and takes into account a variety of climatological, biogeochemical, and geodynamical processes. This allows us to identify a so-called photosynthesis-sustaining habitable zone (pHZ), as determined by the limits of biological productivity on the planetary surface. Our model considers solar evolution during the main-sequence stage and along the Red Giant Branch as described by the most recent solar model. We obtain a large set of solutions consistent with the principal possibility of life. The highest likelihood of habitability is found for "water worlds." Only mass-rich water worlds are able to realize pHZ-type habitability beyond the stellar main sequence on the Red Giant Branch.

Empirical Validation of a Thermal Model of a Complex Roof Including Phase Change Materials

Directory of Open Access Journals (Sweden)

Stéphane Guichard

2015-12-01

Full Text Available This paper deals with the empirical validation of a building thermal model of a complex roof including a phase change material (PCM. A mathematical model dedicated to PCMs based on the heat apparent capacity method was implemented in a multi-zone building simulation code, the aim being to increase the understanding of the thermal behavior of the whole building with PCM technologies. In order to empirically validate the model, the methodology is based both on numerical and experimental studies. A parametric sensitivity analysis was performed and a set of parameters of the thermal model has been identified for optimization. The use of the generic optimization program called GenOpt® coupled to the building simulation code enabled to determine the set of adequate parameters. We first present the empirical validation methodology and main results of previous work. We then give an overview of GenOpt® and its coupling with the building simulation code. Finally, once the optimization results are obtained, comparisons of the thermal predictions with measurements are found to be acceptable and are presented.

Recruiting Underserved Mothers to Medical Research: Findings from North Carolina

Science.gov (United States)

Spears, Chaya R.; Sandberg, Joanne C.; O’Neill, Jenna L.; Grzywacz, Joseph G.; Howard, Timothy D.; Feldman, Steven R.; Arcury, Thomas A.

2014-01-01

Representative samples are required for ethical, valid, and useful health research. Yet, recruiting participants, especially from historically underserved communities, can be challenging. This paper presents findings from in-depth interviews with 40 mothers about factors that might influence their willingness to participate or allow their children to participate in medical research. Saliency analysis organizes the findings. Frequent and important salient themes about research participation included concerns that it might cause participants harm, hope that participants might gain a health benefit, and recognition that time and transportation resources could limit participation. Ultimately, we propose that a theoretical model, such as the Theory of Planned Behavior (TPB), will facilitate more systematic evaluation of effective methods for recruitment and retention of participants in medical research. Future research should explore the utility of such a model for development of effective recruitment and retention strategies. PMID:24185171

TS Fuzzy Model-Based Controller Design for a Class of Nonlinear Systems Including Nonsmooth Functions

DEFF Research Database (Denmark)

Vafamand, Navid; Asemani, Mohammad Hassan; Khayatiyan, Alireza

2018-01-01

This paper proposes a novel robust controller design for a class of nonlinear systems including hard nonlinearity functions. The proposed approach is based on Takagi-Sugeno (TS) fuzzy modeling, nonquadratic Lyapunov function, and nonparallel distributed compensation scheme. In this paper, a novel...... criterion, new robust controller design conditions in terms of linear matrix inequalities are derived. Three practical case studies, electric power steering system, a helicopter model and servo-mechanical system, are presented to demonstrate the importance of such class of nonlinear systems comprising...

Prefrontal Control and Internet Addiction: A Theoretical Model and Review of Neuropsychological and Neuroimaging Findings

Science.gov (United States)

Brand, Matthias; Young, Kimberly S.; Laier, Christian

2014-01-01

Most people use the Internet as a functional tool to perform their personal goals in everyday-life such as making airline or hotel reservations. However, some individuals suffer from a loss of control over their Internet use resulting in personal distress, symptoms of psychological dependence, and diverse negative consequences. This phenomenon is often referred to as Internet addiction. Only Internet Gaming Disorder has been included in the appendix of the DSM-5, but it has already been argued that Internet addiction could also comprise problematic use of other applications with cybersex, online relations, shopping, and information search being Internet facets at risk for developing an addictive behavior. Neuropsychological investigations have pointed out that certain prefrontal functions in particular executive control functions are related to symptoms of Internet addiction, which is in line with recent theoretical models on the development and maintenance of the addictive use of the Internet. Control processes are particularly reduced when individuals with Internet addiction are confronted with Internet-related cues representing their first choice use. For example, processing Internet-related cues interferes with working memory performance and decision making. Consistent with this, results from functional neuroimaging and other neuropsychological studies demonstrate that cue-reactivity, craving, and decision making are important concepts for understanding Internet addiction. The findings on reductions in executive control are consistent with other behavioral addictions, such as pathological gambling. They also emphasize the classification of the phenomenon as an addiction, because there are also several similarities with findings in substance dependency. The neuropsychological and neuroimaging results have important clinical impact, as one therapy goal should enhance control over the Internet use by modifying specific cognitions and Internet use expectancies

Prefrontal control and internet addiction: a theoretical model and review of neuropsychological and neuroimaging findings.

Science.gov (United States)

Brand, Matthias; Young, Kimberly S; Laier, Christian

2014-01-01

Most people use the Internet as a functional tool to perform their personal goals in everyday-life such as making airline or hotel reservations. However, some individuals suffer from a loss of control over their Internet use resulting in personal distress, symptoms of psychological dependence, and diverse negative consequences. This phenomenon is often referred to as Internet addiction. Only Internet Gaming Disorder has been included in the appendix of the DSM-5, but it has already been argued that Internet addiction could also comprise problematic use of other applications with cybersex, online relations, shopping, and information search being Internet facets at risk for developing an addictive behavior. Neuropsychological investigations have pointed out that certain prefrontal functions in particular executive control functions are related to symptoms of Internet addiction, which is in line with recent theoretical models on the development and maintenance of the addictive use of the Internet. Control processes are particularly reduced when individuals with Internet addiction are confronted with Internet-related cues representing their first choice use. For example, processing Internet-related cues interferes with working memory performance and decision making. Consistent with this, results from functional neuroimaging and other neuropsychological studies demonstrate that cue-reactivity, craving, and decision making are important concepts for understanding Internet addiction. The findings on reductions in executive control are consistent with other behavioral addictions, such as pathological gambling. They also emphasize the classification of the phenomenon as an addiction, because there are also several similarities with findings in substance dependency. The neuropsychological and neuroimaging results have important clinical impact, as one therapy goal should enhance control over the Internet use by modifying specific cognitions and Internet use expectancies.

Improvement in genetic evaluation of female fertility in dairy cattle using multiple-trait models including milk production traits

DEFF Research Database (Denmark)

Sun, C; Madsen, P; Lund, M S

2010-01-01

This study investigated the improvement in genetic evaluation of fertility traits by using production traits as secondary traits (MILK = 305-d milk yield, FAT = 305-d fat yield, and PROT = 305-d protein yield). Data including 471,742 records from first lactations of Denmark Holstein cows, covering...... the years of inseminations during first lactations from 1995 to 2004, were analyzed. Six fertility traits (i.e., interval in days from calving to first insemination, calving interval, days open, interval in days from first to last insemination, numbers of inseminations per conception, and nonreturn rate...... stability and predictive ability than single-trait models for all the fertility traits, except for nonreturn rate within 56 d after first service. The stability and predictive ability for the model including MILK or PROT were similar to the model including all 3 milk production traits and better than...

Validation on groundwater flow model including sea level change. Modeling on groundwater flow in coastal granite area

International Nuclear Information System (INIS)

Hasegawa, Takuma; Miyakawa, Kimio

2009-01-01

It is important to verify the groundwater flow model that reproduces pressure head, water chemistry, and groundwater age. However, water chemistry and groundwater age are considered to be influenced by historical events. In this study, sea level change during glacial-interglacial cycle was taken into account for simulating salinity and groundwater age at coastal granite area. As a result of simulation, salinity movement could not catch up with sea level changes, and mixing zone was formed below the fresh-water zone. This mixing zone was observed in the field measurement, and the observed salinities were agreed with simulated results including sea level change. The simulated residence time including sea level change is one-tenth of steady state. The reason is that the saline water was washed out during regression and modern sea-water was infiltrated during transgression. As mentioned before, considering sea level change are important to reproduce salinity and helium age at coastal area. (author)

A New Circuit Model for Spin-Torque Oscillator Including Perpendicular Torque of Magnetic Tunnel Junction

Directory of Open Access Journals (Sweden)

Hyein Lim

2013-01-01

Full Text Available Spin-torque oscillator (STO is a promising new technology for the future RF oscillators, which is based on the spin-transfer torque (STT effect in magnetic multilayered nanostructure. It is expected to provide a larger tunability, smaller size, lower power consumption, and higher level of integration than the semiconductor-based oscillators. In our previous work, a circuit-level model of the giant magnetoresistance (GMR STO was proposed. In this paper, we present a physics-based circuit-level model of the magnetic tunnel junction (MTJ-based STO. MTJ-STO model includes the effect of perpendicular torque that has been ignored in the GMR-STO model. The variations of three major characteristics, generation frequency, mean oscillation power, and generation linewidth of an MTJ-STO with respect to the amount of perpendicular torque, are investigated, and the results are applied to our model. The operation of the model was verified by HSPICE simulation, and the results show an excellent agreement with the experimental data. The results also prove that a full circuit-level simulation with MJT-STO devices can be made with our proposed model.

Target oriented relational model finding

OpenAIRE

Cunha, Alcino; Macedo, Nuno Filipe Moreira; Guimarães, Tiago Miguel Moreira

2014-01-01

Lecture Notes in Computer Science 8411, 2014 Model finders are becoming useful in many software engineering problems. Kodkod is one of the most popular, due to its support for relational logic (a combination of first order logic with relational algebra operators and transitive closure), allowing a simpler specification of constraints, and support for partial instances, allowing the specification of a priori (exact, but potentially partial) knowledge about a problem's solution. However, in ...

The Ultrasonographic Findings of Trigger Points of Myofascial Pain Syndrome in a Rabbit Model

International Nuclear Information System (INIS)

Moon, Kyung Mi; Park, Seog Hee; Lee, Sang Heon; Kim, Joo Hyun; Kim, Han Kyum

2005-01-01

Myofascial pain syndrome (MPS) is a common cause of musculoskeletal pain. Myofascial trigger points (MTrPs) have been repeatedly described by numerous authors. However, there have been few studies in which their existence and behavior was supported and their location confirmed. The purpose of this study was to determine whether diagnostic ultrasonography is an objective diagnostic tool which is able to significantly identify or detect the soft tissue changes in the region of clinically identified active MTrPs by using a rabbit experimental model. Ten MPS model rabbits were used in this study. We made an MPS animal model by causing the rabbits to overuse one leg for 3 weeks by cutting the contralateral L4 spinal nerve root. We compared the ultrasonographic findings of the taut band at pre-OP with those at post-OP during the consecutive three week period. To find the taut bands of the muscle, after skin exposure, the muscles were gently rubbed or pinched with the thumb and index finger on the two opposing surfaces of the muscle across the direction of the fibers. Then, the muscle was held in the same way, but with a 5-8 MHz stick probe being used in place of the thumb. After the palpation of various muscles, we selected the hardest and largest myofascial trigger nodule, in order to observe the ultrasonographic and power Doppler findings of the MPS. The size, shape, echogenecity and vascularity of the MTrPs were observed. The analysis of the results of the ultrasonography revealed that all MTrPs have a hyperechoic area. The mean thickness of the hyperechoic lesion in the biceps was 0.96±0.14 cm in the MPS site (at pre-OP?), and 0.49±0.12 cm at post-OP 3weeks (p < 0.01). The hyperechoic lesions in all of the studied biceps femoris of the rabbits were observed by high resolution ultrasonography. No definitively decreased vascularity was observed within the hyperechoic area by power Doppler imaging. Until now, there has been no objective method for the diagnosis of MPS

Dynamic experiments with high bisphenol-A concentrations modelled with an ASM model extended to include a separate XOC degrading microorganism

DEFF Research Database (Denmark)

Lindblom, Erik Ulfson; Press-Kristensen, Kåre; Vanrolleghem, P.A.

2009-01-01

The perspective of this work is to develop a model, which can be used to better understand and optimize wastewater treatment plants that are able to remove xenobiotic organic compounds (XOCs) in combination with removal of traditional pollutants. Results from dynamic experiments conducted...... with the endocrine disrupting XOC bisphenol-A (BPA) in an activated sludge process with real wastewater were used to hypothesize an ASM-based process model including aerobic growth of a specific BPA-degrading microorganism and sorption of BPA to sludge. A parameter estimation method was developed, which...... simultaneously utilizes steady-state background concentrations and dynamic step response data, as well as conceptual simplifications of the plant configuration. Validation results show that biodegradation of BPA is sensitive to operational conditions before and during the experiment and that the proposed model...

Including local rainfall dynamics and uncertain boundary conditions into a 2-D regional-local flood modelling cascade

Science.gov (United States)

Bermúdez, María; Neal, Jeffrey C.; Bates, Paul D.; Coxon, Gemma; Freer, Jim E.; Cea, Luis; Puertas, Jerónimo

2016-04-01

Flood inundation models require appropriate boundary conditions to be specified at the limits of the domain, which commonly consist of upstream flow rate and downstream water level. These data are usually acquired from gauging stations on the river network where measured water levels are converted to discharge via a rating curve. Derived streamflow estimates are therefore subject to uncertainties in this rating curve, including extrapolating beyond the maximum observed ratings magnitude. In addition, the limited number of gauges in reach-scale studies often requires flow to be routed from the nearest upstream gauge to the boundary of the model domain. This introduces additional uncertainty, derived not only from the flow routing method used, but also from the additional lateral rainfall-runoff contributions downstream of the gauging point. Although generally assumed to have a minor impact on discharge in fluvial flood modeling, this local hydrological input may become important in a sparse gauge network or in events with significant local rainfall. In this study, a method to incorporate rating curve uncertainty and the local rainfall-runoff dynamics into the predictions of a reach-scale flood inundation model is proposed. Discharge uncertainty bounds are generated by applying a non-parametric local weighted regression approach to stage-discharge measurements for two gauging stations, while measured rainfall downstream from these locations is cascaded into a hydrological model to quantify additional inflows along the main channel. A regional simplified-physics hydraulic model is then applied to combine these inputs and generate an ensemble of discharge and water elevation time series at the boundaries of a local-scale high complexity hydraulic model. Finally, the effect of these rainfall dynamics and uncertain boundary conditions are evaluated on the local-scale model. Improvements in model performance when incorporating these processes are quantified using observed

Challenges of including nitrogen effects on decomposition in earth system models

Science.gov (United States)

Hobbie, S. E.

2011-12-01

Despite the importance of litter decomposition for ecosystem fertility and carbon balance, key uncertainties remain about how this fundamental process is affected by nitrogen (N) availability. Nevertheless, resolving such uncertainties is critical for mechanistic inclusion of such processes in earth system models, towards predicting the ecosystem consequences of increased anthropogenic reactive N. Towards that end, we have conducted a series of experiments examining nitrogen effects on litter decomposition. We found that both substrate N and externally supplied N (regardless of form) accelerated the initial decomposition rate. Faster initial decomposition rates were linked to the higher activity of carbohydrate-degrading enzymes associated with externally supplied N and the greater relative abundances of Gram negative and Gram positive bacteria associated with green leaves and externally supplied organic N (assessed using phospholipid fatty acid analysis, PLFA). By contrast, later in decomposition, externally supplied N slowed decomposition, increasing the fraction of slowly decomposing litter and reducing lignin-degrading enzyme activity and relative abundances of Gram negative and Gram positive bacteria. Our results suggest that elevated atmospheric N deposition may have contrasting effects on the dynamics of different soil carbon pools, decreasing mean residence times of active fractions comprising very fresh litter, while increasing those of more slowly decomposing fractions including more processed litter. Incorporating these contrasting effects of N on decomposition processes into models is complicated by lingering uncertainties about how these effects generalize across ecosystems and substrates.

A generalized model for optimal transport of images including dissipation and density modulation

KAUST Repository

Maas, Jan

2015-11-01

© EDP Sciences, SMAI 2015. In this paper the optimal transport and the metamorphosis perspectives are combined. For a pair of given input images geodesic paths in the space of images are defined as minimizers of a resulting path energy. To this end, the underlying Riemannian metric measures the rate of transport cost and the rate of viscous dissipation. Furthermore, the model is capable to deal with strongly varying image contrast and explicitly allows for sources and sinks in the transport equations which are incorporated in the metric related to the metamorphosis approach by Trouvé and Younes. In the non-viscous case with source term existence of geodesic paths is proven in the space of measures. The proposed model is explored on the range from merely optimal transport to strongly dissipative dynamics. For this model a robust and effective variational time discretization of geodesic paths is proposed. This requires to minimize a discrete path energy consisting of a sum of consecutive image matching functionals. These functionals are defined on corresponding pairs of intensity functions and on associated pairwise matching deformations. Existence of time discrete geodesics is demonstrated. Furthermore, a finite element implementation is proposed and applied to instructive test cases and to real images. In the non-viscous case this is compared to the algorithm proposed by Benamou and Brenier including a discretization of the source term. Finally, the model is generalized to define discrete weighted barycentres with applications to textures and objects.

Insert Tidal Here: Finding Stability of Galilean Satellite Interiors

Science.gov (United States)

Walker, M.; Bills, B. G.; Mitchell, J.; Rhoden, A.

2017-12-01

The tidal environment is often hypothesized as a cause of surface expression in the satellites of the outer solar system. In two notable cases, Io's volcanism is thought to be driven by tidal heating of its mantle while the shattered surface of Europa's ice shell is said to be generated by tidal stresses in that ice. Being adjacent moons of Jupiter, these satellites give us a unique opportunity to apply a single set of general coupled models at each body to predict how one model can predict the heat generation and flow, strain and stress states, and structural parameters for each body. We include the effects of interior evolution into the tidal environment in addition to an evolving orbit. We find that the interiors of Io and Europa will evolve, as a consequence of the heat transfer from interior to surface, and stable structural and heat flow conditions are found. Then as their orbits evolve, perturbed by the mutual interactions of the Laplace mean motion resonance, those conditions of structural and heat stability also change. In particular, we find that at current orbital conditions there is sufficient heat to completely melt Io models for which a convecting interior is capped by a conducting lid. This argues for the presence of a non dissipating (or barely dissipating) core below the mantle, which future Io structure models should include. For the Europa model at current orbit, we use a silicate interior under an ocean capped by a two layer ice; convecting below with a conducting surface. We find stability in heat and structure occurs when the lower ice melts and recedes until the shell is roughly 50km thick. We present a variety of plausible structures for these bodies, and track how the stability of those structures trend as the orbit (in particular the orbital eccentricity, mean motion, and obliquity) change. We show how the Love numbers, layer thicknesses, surface heat flow, and orbital parameters are all linked. For Europa, upcoming measurements from

Defecography - analysis of qualitative findings

International Nuclear Information System (INIS)

Schott, U.; Braunschweig, R.; Claussen, C.D.

1994-01-01

The defectography is an examination of the anorectal function in defecatory disorder. The defecography has a diagnostic impact on disease, which only emerge during defecation as intussusception, enterocele, prolapse or sphincter dysfunction. Other findings as rectocele or descending pelvic floor are ambiguous concerning clinical relevance. The interpretation of defecography should include patient's history and clinical findings and - if available -endoscopic and manometric findings. (orig.) [de

Prefrontal control and Internet addiction: A theoretical model and review of neuropsychological and neuroimaging findings

Directory of Open Access Journals (Sweden)

Matthias eBrand

2014-05-01

Full Text Available Most people use the Internet as a functional tool to perform their personal goals in everyday-life such as making airline or hotel reservations. However, some individuals suffer from a loss of control over their Internet use resulting in personal distress, symptoms of psychological dependence, and diverse negative consequences. This phenomenon is often referred to as Internet addiction. Only Internet Gaming Disorder has been included in the appendix of the DSM-5, but it has already been argued that Internet addiction could also comprise problematic use of other applications with cybersex, online relations, shopping, and information search being Internet facets at risk for developing an addictive behavior. Neuropsychological investigations have pointed out that certain prefrontal functions in particular executive control functions are related to symptoms of Internet addiction, which is in line with recent theoretical models on the development and maintenance of the addictive use of the Internet. Control processes are particularly reduced when individuals with Internet addiction are confronted with Internet-related cues representing their first choice use. For example, processing Internet-related cues interferes with working memory performance and decision making. Consistent with this, results from functional neuroimaging and other neuropsychological studies demonstrate that cue-reactivity, craving, and decision making are important concepts for understanding Internet addiction. The findings on reductions in executive control are consistent with other behavioral addictions, such as pathological gambling. They also emphasize the classification of the phenomenon as an addiction, because there are also several similarities with findings in substance dependency. The neuropsychological and neuroimaging results have important clinical impact, as one therapy goal should be to enhance control over the Internet use by modifying specific cognitions and

Web-accessible molecular modeling with Rosetta: The Rosetta Online Server that Includes Everyone (ROSIE).

Science.gov (United States)

Moretti, Rocco; Lyskov, Sergey; Das, Rhiju; Meiler, Jens; Gray, Jeffrey J

2018-01-01

The Rosetta molecular modeling software package provides a large number of experimentally validated tools for modeling and designing proteins, nucleic acids, and other biopolymers, with new protocols being added continually. While freely available to academic users, external usage is limited by the need for expertise in the Unix command line environment. To make Rosetta protocols available to a wider audience, we previously created a web server called Rosetta Online Server that Includes Everyone (ROSIE), which provides a common environment for hosting web-accessible Rosetta protocols. Here we describe a simplification of the ROSIE protocol specification format, one that permits easier implementation of Rosetta protocols. Whereas the previous format required creating multiple separate files in different locations, the new format allows specification of the protocol in a single file. This new, simplified protocol specification has more than doubled the number of Rosetta protocols available under ROSIE. These new applications include pK a determination, lipid accessibility calculation, ribonucleic acid redesign, protein-protein docking, protein-small molecule docking, symmetric docking, antibody docking, cyclic toxin docking, critical binding peptide determination, and mapping small molecule binding sites. ROSIE is freely available to academic users at http://rosie.rosettacommons.org. © 2017 The Protein Society.

Time domain contact model for tyre/road interaction including nonlinear contact stiffness due to small-scale roughness

Science.gov (United States)

Andersson, P. B. U.; Kropp, W.

2008-11-01

Rolling resistance, traction, wear, excitation of vibrations, and noise generation are all attributes to consider in optimisation of the interaction between automotive tyres and wearing courses of roads. The key to understand and describe the interaction is to include a wide range of length scales in the description of the contact geometry. This means including scales on the order of micrometres that have been neglected in previous tyre/road interaction models. A time domain contact model for the tyre/road interaction that includes interfacial details is presented. The contact geometry is discretised into multiple elements forming pairs of matching points. The dynamic response of the tyre is calculated by convolving the contact forces with pre-calculated Green's functions. The smaller-length scales are included by using constitutive interfacial relations, i.e. by using nonlinear contact springs, for each pair of contact elements. The method is presented for normal (out-of-plane) contact and a method for assessing the stiffness of the nonlinear springs based on detailed geometry and elastic data of the tread is suggested. The governing equations of the nonlinear contact problem are solved with the Newton-Raphson iterative scheme. Relations between force, indentation, and contact stiffness are calculated for a single tread block in contact with a road surface. The calculated results have the same character as results from measurements found in literature. Comparison to traditional contact formulations shows that the effect of the small-scale roughness is large; the contact stiffness is only up to half of the stiffness that would result if contact is made over the whole element directly to the bulk of the tread. It is concluded that the suggested contact formulation is a suitable model to include more details of the contact interface. Further, the presented result for the tread block in contact with the road is a suitable input for a global tyre/road interaction model

Imaging findings of sacral tumors

International Nuclear Information System (INIS)

Kim, Seung Ho; Hong, Sung Hwan; Choi, Ja Young; Koh, Sung Hye; Chung, Hye Won; Choi, Jung Ah; Kang, Heung Sik

2003-01-01

The various pathologic conditions detected at CT and MRI and subsumed by the term 'sacral tumor' include primary bone tumors, sacral canal tumors and metastases. Among these, metastases are much more common than primary bone tumors, of which chordoma is the most common. Although the imaging findings of sacral tumors are nonspecific, a patient's age and sex, and specific findings such as calcification or fluid-fluid levels, can help radiologists in their differential diagnosis. We describe the imaging findings of primary sacral tumors, emphasizing the MRI findings

Constraints on inflation revisited. An analysis including the latest local measurement of the Hubble constant

Energy Technology Data Exchange (ETDEWEB)

Guo, Rui-Yun [Northeastern University, Department of Physics, College of Sciences, Shenyang (China); Zhang, Xin [Northeastern University, Department of Physics, College of Sciences, Shenyang (China); Peking University, Center for High Energy Physics, Beijing (China)

2017-12-15

We revisit the constraints on inflation models by using the current cosmological observations involving the latest local measurement of the Hubble constant (H{sub 0} = 73.00 ± 1.75 km s{sup -1} Mpc{sup -1}). We constrain the primordial power spectra of both scalar and tensor perturbations with the observational data including the Planck 2015 CMB full data, the BICEP2 and Keck Array CMB B-mode data, the BAO data, and the direct measurement of H{sub 0}. In order to relieve the tension between the local determination of the Hubble constant and the other astrophysical observations, we consider the additional parameter N{sub eff} in the cosmological model. We find that, for the ΛCDM+r+N{sub eff} model, the scale invariance is only excluded at the 3.3σ level, and ΔN{sub eff} > 0 is favored at the 1.6σ level. Comparing the obtained 1σ and 2σ contours of (n{sub s},r) with the theoretical predictions of selected inflation models, we find that both the convex and the concave potentials are favored at 2σ level, the natural inflation model is excluded at more than 2σ level, the Starobinsky R{sup 2} inflation model is only favored at around 2σ level, and the spontaneously broken SUSY inflation model is now the most favored model. (orig.)

A new model for including the effect of fly ash on biochemical methane potential.

Science.gov (United States)

Gertner, Pablo; Huiliñir, César; Pinto-Villegas, Paula; Castillo, Alejandra; Montalvo, Silvio; Guerrero, Lorna

2017-10-01

The modelling of the effect of trace elements on anaerobic digestion, and specifically the effect of fly ash, has been scarcely studied. Thus, the present work was aimed at the development of a new function that allows accumulated methane models to predict the effect of FA on the volume of methane accumulation. For this, purpose five fly ash concentrations (10, 25, 50, 250 and 500mg/L) using raw and pre-treated sewage sludge were used to calibrate the new function, while three fly ash concentrations were used (40, 150 and 350mg/L) for validation. Three models for accumulated methane volume (the modified Gompertz equation, the logistic function, and the transfer function) were evaluated. The results showed that methane production increased in the presence of FA when the sewage sludge was not pre-treated, while with pretreated sludge there is inhibition of methane production at FA concentrations higher than 50mg/L. In the calibration of the proposed function, it fits well with the experimental data under all the conditions, including the inhibition and stimulating zones, with the values of the parameters of the methane production models falling in the range of those reported in the literature. For validation experiments, the model succeeded in representing the behavior of new experiments in both the stimulating and inhibiting zones, with NRMSE and R 2 ranging from 0.3577 to 0.03714 and 0.2209 to 0.9911, respectively. Thus, the proposed model is robust and valid for the studied conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Hydrological Concept including Lateral Water Flow Compatible with the Biogeochemical Model ForSAFE

Directory of Open Access Journals (Sweden)

Giuliana Zanchi

2016-03-01

Full Text Available The study presents a hydrology concept developed to include lateral water flow in the biogeochemical model ForSAFE. The hydrology concept was evaluated against data collected at Svartberget in the Vindeln Research Forest in Northern Sweden. The results show that the new concept allows simulation of a saturated and an unsaturated zone in the soil as well as water flow that reaches the stream comparable to measurements. The most relevant differences compared to streamflow measurements are that the model simulates a higher base flow in winter and lower flow peaks after snowmelt. These differences are mainly caused by the assumptions made to regulate the percolation at the bottom of the simulated soil columns. The capability for simulating lateral flows and a saturated zone in ForSAFE can greatly improve the simulation of chemical exchange in the soil and export of elements from the soil to watercourses. Such a model can help improve the understanding of how environmental changes in the forest landscape will influence chemical loads to surface waters.

38 CFR 41.315 - Audit findings follow-up.

Science.gov (United States)

2010-07-01

... include audit findings from multiple years, it shall include the fiscal year in which the finding... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Audit findings follow-up... (CONTINUED) AUDITS OF STATES, LOCAL GOVERNMENTS, AND NON-PROFIT ORGANIZATIONS Auditees § 41.315 Audit...

Metasynthesis findings: potential versus reality.

Science.gov (United States)

Finfgeld-Connett, Deborah

2014-11-01

Early on, qualitative researchers predicted that metasynthesis research had the potential to significantly push knowledge development forward. More recently, scholars have questioned whether this is actually occurring. To examine this concern, a randomly selected sample of metasynthesis articles was systematically reviewed to identify the types of findings that have been produced. Based on this systematic examination, it appears that findings from metasynthesis investigations might not be reaching their full potential. Metasynthesis investigations frequently result in isolated findings rather than findings in relationship, and opportunities to generate research hypotheses and theoretical models are not always fully realized. With this in mind, methods for moving metasynthesis findings into relationship are discussed. © The Author(s) 2014.

Constitutive modeling of multiphase materials including phase transformations

NARCIS (Netherlands)

Perdahcioglu, Emin Semih; Geijselaers, Hubertus J.M.; Khan, A.S.; Meredith, C; Farrokh, B

2011-01-01

A constitutive model is developed for materials involving two or more different phases in their microstructure such as DP (Dual Phase) or TRIP (TRansformation Induced Plasticity) steels. Homogenization of the response of the phases is achieved by the Mean-Field method. One of the phases in TRIP

Fuzzy Control of Yaw and Roll Angles of a Simulated Helicopter Model Includes Articulated Manipulators

Directory of Open Access Journals (Sweden)

Hossein Sadegh Lafmejani

2015-09-01

Full Text Available Fuzzy logic controller (FLC is a heuristic method by If-Then Rules which resembles human intelligence and it is a good method for designing Non-linear control systems. In this paper, an arbitrary helicopter model includes articulated manipulators has been simulated with Matlab SimMechanics toolbox. Due to the difficulties of modeling this complex system, a fuzzy controller with simple fuzzy rules has been designed for its yaw and roll angles in order to stabilize the helicopter while it is in the presence of disturbances or its manipulators are moving for a task. Results reveal that a simple FLC can appropriately control this system.

Gis-Based Route Finding Using ANT Colony Optimization and Urban Traffic Data from Different Sources

Science.gov (United States)

Davoodi, M.; Mesgari, M. S.

2015-12-01

Nowadays traffic data is obtained from multiple sources including GPS, Video Vehicle Detectors (VVD), Automatic Number Plate Recognition (ANPR), Floating Car Data (FCD), VANETs, etc. All such data can be used for route finding. This paper proposes a model for finding the optimum route based on the integration of traffic data from different sources. Ant Colony Optimization is applied in this paper because the concept of this method (movement of ants in a network) is similar to urban road network and movements of cars. The results indicate that this model is capable of incorporating data from different sources, which may even be inconsistent.

Obstacles to implementing evidence-based practice in Belgium: a context-specific qualitative evidence synthesis including findings from different health care disciplines.

Science.gov (United States)

Hannes, K; Goedhuys, J; Aertgeerts, B

2012-01-01

A number of barriers to the implementation of evidence-based practice have already been inventoried. However, little attention has been given to their context-specific nature. This qualitative evidence synthesis examines commonalities in the obstacles perceived by different groups of health care practitioners working in the Belgian health care system and sets out to discuss potential strategies to bridge some of these barriers. We actively searched for primary studies addressing our topic of interest in international and national databases (1990 to May 2008), consulted experts and screened references of retrieved studies. We opted for the meta-aggregative approach, developed by the Joanna Briggs Institute, to analyse our findings. The findings indicate that (1) evidence might have a limited role in decision-making processes; (2) aspects other than quality of care steer the evidence-based practice agenda; (3) some health care providers benefit less from evidence-based practice than others and (4) there is a lack of competences to put the evidence-based principles in practice. Belgian policy makers might consider health care system characteristics from and strategies developed or suggested by others to respond to country-specific obstacles. Examples include but are not limited to; (a) providing incentives for patient-centred care coordination and patient communication, (b) supporting practitioners interested in applying research-related activities, (c) considering direct access systems and interprofessional learning to respond to the demand for autonomous decision-making from satellite professional groups, (d) systematically involving allied health professionals in important governmental advisory boards, (e) considering pharmaceutical companies perceived as 'the enemy' an ally in filling in research gaps, (f) embedding the evaluation of evidence-based knowledge and skills in examinations (g) moving from (in)formative learning to transformative learning and (h

Pediatric AIDS. Neuroradiologic and neurodevelopmental findings

Energy Technology Data Exchange (ETDEWEB)

Price, D.B.; Haller, J.O.; Kramer, J.; Hotson, G.C.; Loh, J.P.; Schlusselberg, D.; Inglese, C.M.; Jacobs, J.; Rose, A.L.; Menez-Bautista, R.

1988-09-01

A group of 23 pediatric patients seropositive for HIV antibody were studied by computed tomography and evaluated neurodevelopmentally. Significant neurodevelopmental delays were found in over 95% of the patients studied. CT findings in six patients were normal and thirteen of 23 (57%) had prominence of the CSF spaces. Less frequent findings included calcifications in the basal ganglia and white matter. Cerebral mass lesions included one case of lymphoma and one case of hemorrhage. The CT findings in the pediatric age group differs from the adult population in that that contrast enhancing inflammatory mass lesions are uncommon.

Modelling efforts needed to advance herpes simplex virus (HSV) vaccine development: Key findings from the World Health Organization Consultation on HSV Vaccine Impact Modelling.

Science.gov (United States)

Gottlieb, Sami L; Giersing, Birgitte; Boily, Marie-Claude; Chesson, Harrell; Looker, Katharine J; Schiffer, Joshua; Spicknall, Ian; Hutubessy, Raymond; Broutet, Nathalie

2017-06-21

Development of a vaccine against herpes simplex virus (HSV) is an important goal for global sexual and reproductive health. In order to more precisely define the health and economic burden of HSV infection and the theoretical impact and cost-effectiveness of an HSV vaccine, in 2015 the World Health Organization convened an expert consultation meeting on HSV vaccine impact modelling. The experts reviewed existing model-based estimates and dynamic models of HSV infection to outline critical future modelling needs to inform development of a comprehensive business case and preferred product characteristics for an HSV vaccine. This article summarizes key findings and discussions from the meeting on modelling needs related to HSV burden, costs, and vaccine impact, essential data needs to carry out those models, and important model components and parameters. Copyright © 2017. Published by Elsevier Ltd.

Effect of including decay chains on predictions of equilibrium-type terrestrial food chain models

International Nuclear Information System (INIS)

Kirchner, G.

1990-01-01

Equilibrium-type food chain models are commonly used for assessing the radiological impact to man from environmental releases of radionuclides. Usually these do not take into account build-up of radioactive decay products during environmental transport. This may be a potential source of underprediction. For estimating consequences of this simplification, the equations of an internationally recognised terrestrial food chain model have been extended to include decay chains of variable length. Example calculations show that for releases from light water reactors as expected both during routine operation and in the case of severe accidents, the build-up of decay products during environmental transport is generally of minor importance. However, a considerable number of radionuclides of potential radiological significance have been identified which show marked contributions of decay products to calculated contamination of human food and resulting radiation dose rates. (author)

On finding and using identifiable parameter combinations in nonlinear dynamic systems biology models and COMBOS: a novel web implementation.

Science.gov (United States)

Meshkat, Nicolette; Kuo, Christine Er-zhen; DiStefano, Joseph

2014-01-01

Parameter identifiability problems can plague biomodelers when they reach the quantification stage of development, even for relatively simple models. Structural identifiability (SI) is the primary question, usually understood as knowing which of P unknown biomodel parameters p1,…, pi,…, pP are-and which are not-quantifiable in principle from particular input-output (I-O) biodata. It is not widely appreciated that the same database also can provide quantitative information about the structurally unidentifiable (not quantifiable) subset, in the form of explicit algebraic relationships among unidentifiable pi. Importantly, this is a first step toward finding what else is needed to quantify particular unidentifiable parameters of interest from new I-O experiments. We further develop, implement and exemplify novel algorithms that address and solve the SI problem for a practical class of ordinary differential equation (ODE) systems biology models, as a user-friendly and universally-accessible web application (app)-COMBOS. Users provide the structural ODE and output measurement models in one of two standard forms to a remote server via their web browser. COMBOS provides a list of uniquely and non-uniquely SI model parameters, and-importantly-the combinations of parameters not individually SI. If non-uniquely SI, it also provides the maximum number of different solutions, with important practical implications. The behind-the-scenes symbolic differential algebra algorithms are based on computing Gröbner bases of model attributes established after some algebraic transformations, using the computer-algebra system Maxima. COMBOS was developed for facile instructional and research use as well as modeling. We use it in the classroom to illustrate SI analysis; and have simplified complex models of tumor suppressor p53 and hormone regulation, based on explicit computation of parameter combinations. It's illustrated and validated here for models of moderate complexity, with

Modelling of Water Cooled Fuel Including Design Basis and Severe Accidents. Proceedings of a Technical Meeting

International Nuclear Information System (INIS)

2015-11-01

The demands on nuclear fuel have recently been increasing, and include transient regimes, higher discharge burnup and longer fuel cycles. This has resulted in an increase of loads on fuel and core internals. In order to satisfy these demands while ensuring compliance with safety criteria, new national and international programmes have been launched and advanced modelling codes are being developed. The Fukushima Daiichi accident has particularly demonstrated the need for adequate analysis of all aspects of fuel performance to prevent a failure and also to predict fuel behaviour were an accident to occur.This publication presents the Proceedings of the Technical Meeting on Modelling of Water Cooled Fuel Including Design Basis and Severe Accidents, which was hosted by the Nuclear Power Institute of China (NPIC) in Chengdu, China, following the recommendation made in 2013 at the IAEA Technical Working Group on Fuel Performance and Technology. This recommendation was in agreement with IAEA mid-term initiatives, linked to the post-Fukushima IAEA Nuclear Safety Action Plan, as well as the forthcoming Coordinated Research Project (CRP) on Fuel Modelling in Accident Conditions. At the technical meeting in Chengdu, major areas and physical phenomena, as well as types of code and experiment to be studied and used in the CRP, were discussed. The technical meeting provided a forum for international experts to review the state of the art of code development for modelling fuel performance of nuclear fuel for water cooled reactors with regard to steady state and transient conditions, and for design basis and early phases of severe accidents, including experimental support for code validation. A round table discussion focused on the needs and perspectives on fuel modelling in accident conditions. This meeting was the ninth in a series of IAEA meetings, which reflects Member States’ continuing interest in nuclear fuel issues. The previous meetings were held in 1980 (jointly with

Theory and procedures for finding a correct kinetic model for the bacteriorhodopsin photocycle.

Science.gov (United States)

Hendler, R W; Shrager, R; Bose, S

2001-04-26

In this paper, we present the implementation and results of new methodology based on linear algebra. The theory behind these methods is covered in detail in the Supporting Information, available electronically (Shragerand Hendler). In brief, the methods presented search through all possible forward sequential submodels in order to find candidates that can be used to construct a complete model for the BR-photocycle. The methodology is limited only to forward sequential models. If no such models are compatible with the experimental data,none will be found. The procedures apply objective tests and filters to eliminate possibilities that cannot be correct, thus cutting the total number of candidate sequences to be considered. In the current application,which uses six exponentials, the total sequences were cut from 1950 to 49. The remaining sequences were further screened using known experimental criteria. The approach led to a solution which consists of a pair of sequences, one with 5 exponentials showing BR* f L(f) M(f) N O BR and the other with three exponentials showing BR* L(s) M(s) BR. The deduced complete kinetic model for the BR photocycle is thus either a single photocycle branched at the L intermediate or a pair of two parallel photocycles. Reasons for preferring the parallel photocycles are presented. Synthetic data constructed on the basis of the parallel photocycles were indistinguishable from the experimental data in a number of analytical tests that were applied.

Can a one-layer optical skin model including melanin and inhomogeneously distributed blood explain spatially resolved diffuse reflectance spectra?

Science.gov (United States)

Karlsson, Hanna; Pettersson, Anders; Larsson, Marcus; Strömberg, Tomas

2011-02-01

Model based analysis of calibrated diffuse reflectance spectroscopy can be used for determining oxygenation and concentration of skin chromophores. This study aimed at assessing the effect of including melanin in addition to hemoglobin (Hb) as chromophores and compensating for inhomogeneously distributed blood (vessel packaging), in a single-layer skin model. Spectra from four humans were collected during different provocations using a twochannel fiber optic probe with source-detector separations 0.4 and 1.2 mm. Absolute calibrated spectra using data from either a single distance or both distances were analyzed using inverse Monte Carlo for light transport and Levenberg-Marquardt for non-linear fitting. The model fitting was excellent using a single distance. However, the estimated model failed to explain spectra from the other distance. The two-distance model did not fit the data well at either distance. Model fitting was significantly improved including melanin and vessel packaging. The most prominent effect when fitting data from the larger separation compared to the smaller separation was a different light scattering decay with wavelength, while the tissue fraction of Hb and saturation were similar. For modeling spectra at both distances, we propose using either a multi-layer skin model or a more advanced model for the scattering phase function.

A temperature dependent cyclic plasticity model for hot work tool steel including particle coarsening

Science.gov (United States)

Jilg, Andreas; Seifert, Thomas

2018-05-01

Hot work tools are subjected to complex thermal and mechanical loads during hot forming processes. Locally, the stresses can exceed the material's yield strength in highly loaded areas as e.g. in small radii in die cavities. To sustain the high loads, the hot forming tools are typically made of martensitic hot work steels. While temperatures for annealing of the tool steels usually lie in the range between 400 and 600 °C, the steels may experience even higher temperatures during hot forming, resulting in softening of the material due to coarsening of strengthening particles. In this paper, a temperature dependent cyclic plasticity model for the martensitic hot work tool steel 1.2367 (X38CrMoV5-3) is presented that includes softening due to particle coarsening and that can be applied in finite-element calculations to assess the effect of softening on the thermomechanical fatigue life of hot work tools. To this end, a kinetic model for the evolution of the mean size of secondary carbides based on Ostwald ripening is coupled with a cyclic plasticity model with kinematic hardening. Mechanism-based relations are developed to describe the dependency of the mechanical properties on carbide size and temperature. The material properties of the mechanical and kinetic model are determined on the basis of tempering hardness curves as well as monotonic and cyclic tests.

A model for Huanglongbing spread between citrus plants including delay times and human intervention

Science.gov (United States)

Vilamiu, Raphael G. d'A.; Ternes, Sonia; Braga, Guilherme A.; Laranjeira, Francisco F.

2012-09-01

The objective of this work was to present a compartmental deterministic mathematical model for representing the dynamics of HLB disease in a citrus orchard, including delay in the disease's incubation phase in the plants, and a delay period on the nymphal stage of Diaphorina citri, the most important HLB insect vector in Brazil. Numerical simulations were performed to assess the possible impacts of human detection efficiency of symptomatic plants, as well as the influence of a long incubation period of HLB in the plant.

ATEFlap aerodynamic model, a dynamic stall model including the effects of trailing edge flap deflection

Energy Technology Data Exchange (ETDEWEB)

Bergami, L.; Gaunaa, M.

2012-02-15

The report presents the ATEFlap aerodynamic model, which computes the unsteady lift, drag and moment on a 2D airfoil section equipped with Adaptive Trailing Edge Flap. The model captures the unsteady response related to the effects of the vorticity shed into the wake, and the dynamics of flow separation a thin-airfoil potential flow model is merged with a dynamic stall model of the Beddoes-Leishmann type. The inputs required by the model are steady data for lift, drag, and moment coefficients as function of angle of attack and flap deflection. Further steady data used by the Beddoes- Leishmann dynamic stall model are computed in an external preprocessor application, which gives the user the possibility to verify, and eventually correct, the steady data passed to the aerodynamic model. The ATEFlap aerodynamic model is integrated in the aeroelastic simulation tool HAWC2, thus al- lowing to simulate the response of a wind turbine with trailing edge flaps on the rotor. The algorithms used by the preprocessor, and by aerodynamic model are presented, and modifications to previous implementations of the aerodynamic model are briefly discussed. The performance and the validity of the model are verified by comparing the dynamic response computed by the ATEFlap with solutions from CFD simulations. (Author)

Transport modelling including radial electric field and plasma rotation

International Nuclear Information System (INIS)

Fukuyama, A.; Fuji, Y.; Itoh, S.-I.

1994-01-01

Using a simple turbulent transport model with a constant diffusion coefficient and a fixed temperature profile, the density profile in a steady state and the transient behaviour during the co and counter neutral beam injection are studied. More consistent analysis has been initiated with a turbulent transport model based on the current diffusive high-n ballooning mode. The enhancement of the radial electric field due to ion orbit losses and the reduction of the transport due to the poloidal rotation shear are demonstrated. The preliminary calculation indicates a sensitive temperature dependence of the density profile. (author)

How to include frequency dependent complex permeability Into SPICE models to improve EMI filters design?

Science.gov (United States)

Sixdenier, Fabien; Yade, Ousseynou; Martin, Christian; Bréard, Arnaud; Vollaire, Christian

2018-05-01

Electromagnetic interference (EMI) filters design is a rather difficult task where engineers have to choose adequate magnetic materials, design the magnetic circuit and choose the size and number of turns. The final design must achieve the attenuation requirements (constraints) and has to be as compact as possible (goal). Alternating current (AC) analysis is a powerful tool to predict global impedance or attenuation of any filter. However, AC analysis are generally performed without taking into account the frequency-dependent complex permeability behaviour of soft magnetic materials. That's why, we developed two frequency-dependent complex permeability models able to be included into SPICE models. After an identification process, the performances of each model are compared to measurements made on a realistic EMI filter prototype in common mode (CM) and differential mode (DM) to see the benefit of the approach. Simulation results are in good agreement with the measured ones especially in the middle frequency range.

Modelling the residual stresses and microstructural evolution in Friction Stir Welding of AA2024-T3 including the Wagner-Kampmann precipitation model

DEFF Research Database (Denmark)

Sonne, Mads Rostgaard; Hattel, Jesper Henri

In this work, a numerical finite element model for friction stir welding of 2024-T3 aluminum alloy, consisting of a heat transfer analysis and a sequentially coupled quasi-static stress analysis is proposed. Metallurgical softening of the material is properly considered and included...

Including model uncertainty in the model predictive control with output feedback

Directory of Open Access Journals (Sweden)

Rodrigues M.A.

2002-01-01

Full Text Available This paper addresses the development of an efficient numerical output feedback robust model predictive controller for open-loop stable systems. Stability of the closed loop is guaranteed by using an infinite horizon predictive controller and a stable state observer. The performance and the computational burden of this approach are compared to a robust predictive controller from the literature. The case used for this study is based on an industrial gasoline debutanizer column.

The prediction of the cavitation phenomena including population balance modeling

Science.gov (United States)

Bannari, Rachid; Hliwa, Ghizlane Zineb; Bannari, Abdelfettah; Belghiti, Mly Taib

2017-07-01

Cavitation is the principal reason behind the behavior's modification of the hydraulic turbines. However, the experimental observations can not be appropriate to all cases due to the limitations in the measurement techniques. The mathematical models which have been implemented, use the mixture multiphase frame. As well as, most of the published work is limited by considering a constant bubble size distribution. However, this assumption is not realist. The aim of this article is the implementation and the use of a non-homogeneous multiphase model which solve two phases transport equation. The evolution of bubble size is considered by the population balance equation. This study is based on the eulerian-eulerian model, associated to the cavitation model. All the inter-phase forces such as drag, lift and virtual mass are used.

Static, Lightweight Includes Resolution for PHP

NARCIS (Netherlands)

M.A. Hills (Mark); P. Klint (Paul); J.J. Vinju (Jurgen)

2014-01-01

htmlabstractDynamic languages include a number of features that are challenging to model properly in static analysis tools. In PHP, one of these features is the include expression, where an arbitrary expression provides the path of the file to include at runtime. In this paper we present two

Optimization of piezoelectric cantilever energy harvesters including non-linear effects

International Nuclear Information System (INIS)

Patel, R; McWilliam, S; Popov, A A

2014-01-01

This paper proposes a versatile non-linear model for predicting piezoelectric energy harvester performance. The presented model includes (i) material non-linearity, for both substrate and piezoelectric layers, and (ii) geometric non-linearity incorporated by assuming inextensibility and accurately representing beam curvature. The addition of a sub-model, which utilizes the transfer matrix method to predict eigenfrequencies and eigenvectors for segmented beams, allows for accurate optimization of piezoelectric layer coverage. A validation of the overall theoretical model is performed through experimental testing on both uniform and non-uniform samples manufactured in-house. For the harvester composition used in this work, the magnitude of material non-linearity exhibited by the piezoelectric layer is 35 times greater than that of the substrate layer. It is also observed that material non-linearity, responsible for reductions in resonant frequency with increases in base acceleration, is dominant over geometric non-linearity for standard piezoelectric harvesting devices. Finally, over the tested range, energy loss due to damping is found to increase in a quasi-linear fashion with base acceleration. During an optimization study on piezoelectric layer coverage, results from the developed model were compared with those from a linear model. Unbiased comparisons between harvesters were realized by using devices with identical natural frequencies—created by adjusting the device substrate thickness. Results from three studies, each with a different assumption on mechanical damping variations, are presented. Findings showed that, depending on damping variation, a non-linear model is essential for such optimization studies with each model predicting vastly differing optimum configurations. (paper)

GIS-BASED ROUTE FINDING USING ANT COLONY OPTIMIZATION AND URBAN TRAFFIC DATA FROM DIFFERENT SOURCES

Directory of Open Access Journals (Sweden)

M. Davoodi

2015-12-01

Full Text Available Nowadays traffic data is obtained from multiple sources including GPS, Video Vehicle Detectors (VVD, Automatic Number Plate Recognition (ANPR, Floating Car Data (FCD, VANETs, etc. All such data can be used for route finding. This paper proposes a model for finding the optimum route based on the integration of traffic data from different sources. Ant Colony Optimization is applied in this paper because the concept of this method (movement of ants in a network is similar to urban road network and movements of cars. The results indicate that this model is capable of incorporating data from different sources, which may even be inconsistent.

Iwamoto-Harada coalescence/pickup model for cluster emission: state density approach including angular momentum variables

Directory of Open Access Journals (Sweden)

Běták Emil

2014-04-01

Full Text Available For low-energy nuclear reactions well above the resonance region, but still below the pion threshold, statistical pre-equilibrium models (e.g., the exciton and the hybrid ones are a frequent tool for analysis of energy spectra and the cross sections of cluster emission. For α’s, two essentially distinct approaches are popular, namely the preformed one and the different versions of coalescence approaches, whereas only the latter group of models can be used for other types of cluster ejectiles. The original Iwamoto-Harada model of pre-equilibrium cluster emission was formulated using the overlap of the cluster and its constituent nucleons in momentum space. Transforming it into level or state densities is not a straigthforward task; however, physically the same model was presented at a conference on reaction models five years earlier. At that time, only the densities without spin were used. The introduction of spin variables into the exciton model enabled detailed calculation of the γ emission and its competition with nucleon channels, and – at the same time – it stimulated further developments of the model. However – to the best of our knowledge – no spin formulation has been presented for cluster emission till recently, when the first attempts have been reported, but restricted to the first emission only. We have updated this effort now and we are able to handle (using the same simplifications as in our previous work pre-equilibrium cluster emission with spin including all nuclei in the reaction chain.

Including spatial data in nutrient balance modelling on dairy farms

Science.gov (United States)

van Leeuwen, Maricke; van Middelaar, Corina; Stoof, Cathelijne; Oenema, Jouke; Stoorvogel, Jetse; de Boer, Imke

2017-04-01

The Annual Nutrient Cycle Assessment (ANCA) calculates the nitrogen (N) and phosphorus (P) balance at a dairy farm, while taking into account the subsequent nutrient cycles of the herd, manure, soil and crop components. Since January 2016, Dutch dairy farmers are required to use ANCA in order to increase understanding of nutrient flows and to minimize nutrient losses to the environment. A nutrient balance calculates the difference between nutrient inputs and outputs. Nutrients enter the farm via purchased feed, fertilizers, deposition and fixation by legumes (nitrogen), and leave the farm via milk, livestock, manure, and roughages. A positive balance indicates to which extent N and/or P are lost to the environment via gaseous emissions (N), leaching, run-off and accumulation in soil. A negative balance indicates that N and/or P are depleted from soil. ANCA was designed to calculate average nutrient flows on farm level (for the herd, manure, soil and crop components). ANCA was not designed to perform calculations of nutrient flows at the field level, as it uses averaged nutrient inputs and outputs across all fields, and it does not include field specific soil characteristics. Land management decisions, however, such as the level of N and P application, are typically taken at the field level given the specific crop and soil characteristics. Therefore the information that ANCA provides is likely not sufficient to support farmers' decisions on land management to minimize nutrient losses to the environment. This is particularly a problem when land management and soils vary between fields. For an accurate estimate of nutrient flows in a given farming system that can be used to optimize land management, the spatial scale of nutrient inputs and outputs (and thus the effect of land management and soil variation) could be essential. Our aim was to determine the effect of the spatial scale of nutrient inputs and outputs on modelled nutrient flows and nutrient use efficiencies

The Model of the Software Running on a Computer Equipment Hardware Included in the Grid network

Directory of Open Access Journals (Sweden)

T. A. Mityushkina

2012-12-01

Full Text Available A new approach to building a cloud computing environment using Grid networks is proposed in this paper. The authors describe the functional capabilities, algorithm, model of software running on a computer equipment hardware included in the Grid network, that will allow to implement cloud computing environment using Grid technologies.

A nonlinear model for fluid flow in a multiple-zone composite reservoir including the quadratic gradient term

International Nuclear Information System (INIS)

Wang, Xiao-Lu; Fan, Xiang-Yu; Nie, Ren-Shi; Huang, Quan-Hua; He, Yong-Ming

2013-01-01

Based on material balance and Darcy's law, the governing equation with the quadratic pressure gradient term was deduced. Then the nonlinear model for fluid flow in a multiple-zone composite reservoir including the quadratic gradient term was established and solved using a Laplace transform. A series of standard log–log type curves of 1-zone (homogeneous), 2-zone and 3-zone reservoirs were plotted and nonlinear flow characteristics were analysed. The type curves governed by the coefficient of the quadratic gradient term (β) gradually deviate from those of a linear model with time elapsing. Qualitative and quantitative analyses were implemented to compare the solutions of the linear and nonlinear models. The results showed that differences of pressure transients between the linear and nonlinear models increase with elapsed time and β. At the end, a successful application of the theoretical model data against the field data shows that the nonlinear model will be a good tool to evaluate formation parameters more accurately. (paper)

Work Stress and Altered Biomarkers: A Synthesis of Findings Based on the Effort-Reward Imbalance Model.

Science.gov (United States)

Siegrist, Johannes; Li, Jian

2017-11-10

While epidemiological studies provide statistical evidence on associations of exposures such as stressful work with elevated risks of stress-related disorders (e.g., coronary heart disease or depression), additional information on biological pathways and biomarkers underlying these associations is required. In this contribution, we summarize the current state of the art on research findings linking stressful work, in terms of an established theoretical model-effort-reward imbalance-with a broad range of biomarkers. Based on structured electronic literature search and recent available systematic reviews, our synthesis of findings indicates that associations of work stress with heart rate variability, altered blood lipids, and risk of metabolic syndrome are rather consistent and robust. Significant relationships with blood pressure, heart rate, altered immune function and inflammation, cortisol release, and haemostatic biomarkers were also observed, but due to conflicting findings additional data will be needed to reach a firm conclusion. This narrative review of empirical evidence supports the argument that the biomarkers under study can act as mediators of epidemiologically established associations of work stress, as measured by effort-reward imbalance, with incident stress-related disorders.

FIND--a unified framework for neural data analysis.

Science.gov (United States)

Meier, Ralph; Egert, Ulrich; Aertsen, Ad; Nawrot, Martin P

2008-10-01

The complexity of neurophysiology data has increased tremendously over the last years, especially due to the widespread availability of multi-channel recording techniques. With adequate computing power the current limit for computational neuroscience is the effort and time it takes for scientists to translate their ideas into working code. Advanced analysis methods are complex and often lack reproducibility on the basis of published descriptions. To overcome this limitation we develop FIND (Finding Information in Neural Data) as a platform-independent, open source framework for the analysis of neuronal activity data based on Matlab (Mathworks). Here, we outline the structure of the FIND framework and describe its functionality, our measures of quality control, and the policies for developers and users. Within FIND we have developed a unified data import from various proprietary formats, simplifying standardized interfacing with tools for analysis and simulation. The toolbox FIND covers a steadily increasing number of tools. These analysis tools address various types of neural activity data, including discrete series of spike events, continuous time series and imaging data. Additionally, the toolbox provides solutions for the simulation of parallel stochastic point processes to model multi-channel spiking activity. We illustrate two examples of complex analyses with FIND tools: First, we present a time-resolved characterization of the spiking irregularity in an in vivo extracellular recording from a mushroom-body extrinsic neuron in the honeybee during odor stimulation. Second, we describe layer specific input dynamics in the rat primary visual cortex in vivo in response to visual flash stimulation on the basis of multi-channel spiking activity.

CFD simulations and reduced order modeling of a refrigerator compartment including radiation effects

International Nuclear Information System (INIS)

Bayer, Ozgur; Oskay, Ruknettin; Paksoy, Akin; Aradag, Selin

2013-01-01

Highlights: ► Free convection in a refrigerator is simulated including radiation effects. ► Heat rates are affected drastically when radiation effects are considered. ► 95% of the flow energy can be represented by using one spatial POD mode. - Abstract: Considering the engineering problem of natural convection in domestic refrigerator applications, this study aims to simulate the fluid flow and temperature distribution in a single commercial refrigerator compartment by using the experimentally determined temperature values as the specified constant wall temperature boundary conditions. The free convection in refrigerator applications is evaluated as a three-dimensional (3D), turbulent, transient and coupled non-linear flow problem. Radiation heat transfer mode is also included in the analysis. According to the results, taking radiation effects into consideration does not change the temperature distribution inside the refrigerator significantly; however the heat rates are affected drastically. The flow inside the compartment is further analyzed with a reduced order modeling method called Proper Orthogonal Decomposition (POD) and the energy contents of several spatial and temporal modes that exist in the flow are examined. The results show that approximately 95% of all the flow energy can be represented by only using one spatial mode

CT findings of exophageal perforation

Energy Technology Data Exchange (ETDEWEB)

Heo, Jeong Nam; Choi, Yo Won; Jeon, Seok Chol; Park, Choong Ki; Hahm, Chang Kok [Hanyang University College of Medicine, Seoul (Korea, Republic of)

2002-09-01

To determine which CT findings are useful for the early disgnosis of esophageal perforation, and on the basis of these findings, to assess the accuracy of prediction of the perforation site. A review of medical records indicated that between January 1995 and December 2001, 36 patients with esophageal perforation were admitted to our hospital. Thirteen of these [M:F=8:5, age; 28-69 (mean, 52.4) years], who had undergone CT chest scanning, were included in this study. The causes of esophageal perforation were trauma (n=5), infectious diseases (n=4), Boerhaave syndrome (n=1), lung cancer (n=1), esophageal cancer (n=1), and idiopathic. Two chest radiologists unaware of the clinical findings reviewed the CT scans and predicted whether the upper or lower esophagus was perforated. The most common CT finding was extraluminal air at the posterior mediastinum (n=11), while other findings included pulmonary consolidation (n=10), pleural effusion (n=7), discontinuity of the esophageal wall (n=6) and subcutaneous emphysema (n=4), fluid collection around the esophagus (n-4), esophageal wall thickening (n=4), pneumothorax (n=2), and lung abscess (n=2). The perforation site was accurately predicted in 76.9% of cases (10/13). The CT findings which help the diagnosis of esophageal perforation, and prediction of the sites at which it occurs, are extraluminal air of fluid collection, focal defect of the esophageal wall, and esophageal wall thickening.

CT findings of exophageal perforation

International Nuclear Information System (INIS)

Heo, Jeong Nam; Choi, Yo Won; Jeon, Seok Chol; Park, Choong Ki; Hahm, Chang Kok

2002-01-01

To determine which CT findings are useful for the early disgnosis of esophageal perforation, and on the basis of these findings, to assess the accuracy of prediction of the perforation site. A review of medical records indicated that between January 1995 and December 2001, 36 patients with esophageal perforation were admitted to our hospital. Thirteen of these [M:F=8:5, age; 28-69 (mean, 52.4) years], who had undergone CT chest scanning, were included in this study. The causes of esophageal perforation were trauma (n=5), infectious diseases (n=4), Boerhaave syndrome (n=1), lung cancer (n=1), esophageal cancer (n=1), and idiopathic. Two chest radiologists unaware of the clinical findings reviewed the CT scans and predicted whether the upper or lower esophagus was perforated. The most common CT finding was extraluminal air at the posterior mediastinum (n=11), while other findings included pulmonary consolidation (n=10), pleural effusion (n=7), discontinuity of the esophageal wall (n=6) and subcutaneous emphysema (n=4), fluid collection around the esophagus (n-4), esophageal wall thickening (n=4), pneumothorax (n=2), and lung abscess (n=2). The perforation site was accurately predicted in 76.9% of cases (10/13). The CT findings which help the diagnosis of esophageal perforation, and prediction of the sites at which it occurs, are extraluminal air of fluid collection, focal defect of the esophageal wall, and esophageal wall thickening

Radiologic findings of granulomatous mastitis

Energy Technology Data Exchange (ETDEWEB)

Kim, Tae Gyu; Kim, Ji Young; Jeong, Myeong Ja; Kim, Jae Hyung; Kim, Soung Hee; Kim, Soo Hyun; Jun, Woo Sun; Park, Kyeong Mee; Han, Se Hwan [Paik Hospital, Inje University College of Medicine, Seoul (Korea, Republic of)

2008-08-15

The describe the radiologic findings of granulomatous mastitis of the breast. This study included 19 patients (age range: 22 to 56 years; mean 37 years) with 22 lesions that were pathologically confirmed as having granulomatous mastitis. All the patients underwent a breast ultrasonography and 13 patients underwent a mammography. The results of the mammography revealed focal asymmetry (n = 9), multiple ill-defined isodense nodules (n 2), ill-defined nodular density on craniocaudal view (n = 1), and unremarkable finding (n = 1). The sonographic findings included continuous or discontinuous multiple tubular and nodular low echoic lesions (n = 7), ill-defined heterogeneously low echoic lesion (n = 5), irregular-shaped, ill-defined low echoic mass (n = 4), fluid collection with internal floating materials suggesting the presence of an abscess (n = 4), ill-defined heterogeneously low echoic lesion and abscess (n = 1), and multiple ill-defined nodules (n = 1). In the case of granulomatous mastitis, the mammography results indicate a lack of specificity between normal findings and focal asymmetry. The sonographic findings indicate that ill-defined heterogeneously low echoic lesions or irregular shaped, ill-defined low echoic masses are difficult to differentiate from breast cancer. The sonographic findings of abscesses indicate a difficulty in differentiating them from cases of pyogenic mastitis. However, multiple tubular and nodular low echoic lesions, especially with a continuous appearance, should point to granulomatous mastitis, and is helpful in its differential diagnosis and treatment.

Radiologic findings of granulomatous mastitis

International Nuclear Information System (INIS)

Kim, Tae Gyu; Kim, Ji Young; Jeong, Myeong Ja; Kim, Jae Hyung; Kim, Soung Hee; Kim, Soo Hyun; Jun, Woo Sun; Park, Kyeong Mee; Han, Se Hwan

2008-01-01

The describe the radiologic findings of granulomatous mastitis of the breast. This study included 19 patients (age range: 22 to 56 years; mean 37 years) with 22 lesions that were pathologically confirmed as having granulomatous mastitis. All the patients underwent a breast ultrasonography and 13 patients underwent a mammography. The results of the mammography revealed focal asymmetry (n = 9), multiple ill-defined isodense nodules (n 2), ill-defined nodular density on craniocaudal view (n = 1), and unremarkable finding (n = 1). The sonographic findings included continuous or discontinuous multiple tubular and nodular low echoic lesions (n = 7), ill-defined heterogeneously low echoic lesion (n = 5), irregular-shaped, ill-defined low echoic mass (n = 4), fluid collection with internal floating materials suggesting the presence of an abscess (n = 4), ill-defined heterogeneously low echoic lesion and abscess (n = 1), and multiple ill-defined nodules (n = 1). In the case of granulomatous mastitis, the mammography results indicate a lack of specificity between normal findings and focal asymmetry. The sonographic findings indicate that ill-defined heterogeneously low echoic lesions or irregular shaped, ill-defined low echoic masses are difficult to differentiate from breast cancer. The sonographic findings of abscesses indicate a difficulty in differentiating them from cases of pyogenic mastitis. However, multiple tubular and nodular low echoic lesions, especially with a continuous appearance, should point to granulomatous mastitis, and is helpful in its differential diagnosis and treatment

Qanuqtuurniq—finding the balance: an IPY television series using community engagement

Directory of Open Access Journals (Sweden)

Catherine L. Carry

2011-12-01

Full Text Available The three-part television broadcast Qanuqtuurniq—finding the balance was an International Polar Year communications and outreach project concerning Inuit health and wellness. The goal of this project was to engage the Inuit public and others in “real-time” dialogue about health and wellness issues and health research, and to deliver key messages. It was aired live in the Inuit language (with English captions/sub-titles from Iqaluit, Nunavut, Canada, in May 2009 and simultaneously webcast. Qanuqtuurniq—finding the balance used an Inuit communications model for remote communities that was developed in the Arctic in 1994 by the Inuit Broadcasting Corporation/Inuit Communications. In Qanuqtuurniq—finding the balance more than 250 people were engaged through the use of a diverse range of methods, including content working groups, stakeholder input, music recordings, pre-recorded community programme videos, live and public screening of the broadcasts, live panels, live audiences, public phone-ins, Skype video-conferencing and real-time online chat, focus groups and e-mail. This article examines the project in light of the principles of “community engagement”, demonstrating that Qanuqtuurniq—finding the balance exemplifies community engagement in a number of significant ways, including heavily involving community members in the selection of the health theme content of the televised programmes and through the formation of focus groups. Based on challenges encountered during the Qanuqtuurniq—finding the balance project, the article offers recommendations for future projects.

Finding exact constants in a Markov model of Zipfs law generation

Science.gov (United States)

Bochkarev, V. V.; Lerner, E. Yu.; Nikiforov, A. A.; Pismenskiy, A. A.

2017-12-01

According to the classical Zipfs law, the word frequency is a power function of the word rank with an exponent -1. The objective of this work is to find multiplicative constant in a Markov model of word generation. Previously, the case of independent letters was mathematically strictly investigated in [Bochkarev V V and Lerner E Yu 2017 International Journal of Mathematics and Mathematical Sciences Article ID 914374]. Unfortunately, the methods used in this paper cannot be generalized in case of Markov chains. The search of the correct formulation of the Markov generalization of this results was performed using experiments with different ergodic matrices of transition probability P. Combinatory technique allowed taking into account all the words with probability of more than e -300 in case of 2 by 2 matrices. It was experimentally proved that the required constant in the limit is equal to the value reciprocal to conditional entropy of matrix row P with weights presenting the elements of the vector π of the stationary distribution of the Markov chain.

An Investigation of the Academic Information Finding and Re-finding Behavior on the Web

Directory of Open Access Journals (Sweden)

Hsiao-Tieh Pu

2014-12-01

Full Text Available Academic researchers often need and re-use relevant information found after a period of time. This preliminary study used various methods, including experiments, interviews, search log analysis, sequential analysis, and observation to investigate characteristics of academic information finding and re-finding behavior. Overall, the participants in this study entered short queries either in finding or re-finding phases. Comparatively speaking, the participants entered greater number of queries, modified more queries, browsed more web pages, and stayed longer on web pages in the finding phase. On the other hand, in the re-finding phase, they utilized personal information management tools to re-find instead of finding again using search engine, such as checking browsing history; moreover, they tend to input less number of queries and stayed shorter on web pages. In short, the participants interacted more with the retrieval system during the finding phase, while they increased the use of personal information management tools in the re-finding phase. As to the contextual clues used in re-finding phase, the participants used less clues from the target itself, instead, they used indirect clues more often, especially location-related information. Based on the results of sequential analysis, the transition states in the re-finding phase was found to be more complex than those in the finding phase. Web information finding and re-finding behavior is an important and novel area of research. The preliminary results would benefit research on Web information re-finding behavior, and provide useful suggestions for developing personal academic information management systems. [Article content in Chinese

Radiologic findings of anthracofibrosis

International Nuclear Information System (INIS)

Yoon, Mi Jin; Ko, Eun Joo; Yoon, Sook Ja; Tien, Kuang Lung; Yoon, Yong Kyu; Lee, Kyung Soo; Kim, Jin Hwan

1998-01-01

To evaluate the CT findings of bronchial anthracofibrosis. Fourteen patients with bronchoscopically confirmed anthracofibrosis were involved in this study. CT findings (n=3D12) were retrospectively analysed; the pattern, distri-bution and extent of bronchial and parenchymal abnormalities and additional findings such as mediastinal lymphadenopathy and pleural effusion were assessed. Age, sex, and occupational and disease history were history were also reviewed. Patients were aged between 63 and 95 (mean, 71.3) years, and ten were female. Only one patient had an occupational history, but four had a history of pulmonary tuberculosis. Frequent radiologic findings were bronchial wall thickening(n=3D6), atelectasis(n=3D8), mediastinal lymphad-enopathy(n=3D7) and mass(n=3D4). Other accompanying findings were bronchial wall calcification(n=3D3), consolidation(n=3D2) and pleural effusion(n=3D2). Right upper (n=3D7) and right middle lobe(n=3D7) were the most commonly involved sites, and multifocal involvement (n=3D7) was frequent. Bronchial wall thickening, atelectasis and mediastinal lymphadenopathy were characteristic CT findings of anthracofibrosis. When such findings are noted in older or aged female patients, anthracofibrosis should be included in the differential diagnosis

Network optimization including gas lift and network parameters under subsurface uncertainty

Energy Technology Data Exchange (ETDEWEB)

Schulze-Riegert, R.; Baffoe, J.; Pajonk, O. [SPT Group GmbH, Hamburg (Germany); Badalov, H.; Huseynov, S. [Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany). ITE; Trick, M. [SPT Group, Calgary, AB (Canada)

2013-08-01

Optimization of oil and gas field production systems poses a great challenge to field development due to complex and multiple interactions between various operational design parameters and subsurface uncertainties. Conventional analytical methods are capable of finding local optima based on single deterministic models. They are less applicable for efficiently generating alternative design scenarios in a multi-objective context. Practical implementations of robust optimization workflows integrate the evaluation of alternative design scenarios and multiple realizations of subsurface uncertainty descriptions. Production or economic performance indicators such as NPV (Net Present Value) are linked to a risk-weighted objective function definition to guide the optimization processes. This work focuses on an integrated workflow using a reservoir-network simulator coupled to an optimization framework. The work will investigate the impact of design parameters while considering the physics of the reservoir, wells, and surface facilities. Subsurface uncertainties are described by well parameters such as inflow performance. Experimental design methods are used to investigate parameter sensitivities and interactions. Optimization methods are used to find optimal design parameter combinations which improve key performance indicators of the production network system. The proposed workflow will be applied to a representative oil reservoir coupled to a network which is modelled by an integrated reservoir-network simulator. Gas-lift will be included as an explicit measure to improve production. An objective function will be formulated for the net present value of the integrated system including production revenue and facility costs. Facility and gas lift design parameters are tuned to maximize NPV. Well inflow performance uncertainties are introduced with an impact on gas lift performance. Resulting variances on NPV are identified as a risk measure for the optimized system design. A

Mobious syndrome: MR findings

Directory of Open Access Journals (Sweden)

Maskal Revanna Srinivas

2016-01-01

Full Text Available Möbius syndrome is an extremely rare congenital disorder. We report a case of Möbius syndrome in a 2-year-old girl with bilateral convergent squint and left-sided facial weakness. The characteristic magnetic resonance imaging (MRI findings of Möbius syndrome, which include absent bilateral abducens nerves and absent left facial nerve, were noted. In addition, there was absence of left anterior inferior cerebellar artery (AICA and absence of bilateral facial colliculi. Clinical features, etiology, and imaging findings are discussed.

Recovery boiler model; Soodakattilan kehitystyoe III

Energy Technology Data Exchange (ETDEWEB)

Janka, K.; Ylitalo, M.; Sundstroem, K.; Helke, R.; Heinola, M. [Kvaerner Pulping Oy, Tampere (Finland)

1997-10-01

The recovery boiler model was further tested and developed. At this moment the model includes submodels for: droplet drying, pyrolysis, char burning, gas burning and for droplet trajectory. During 1996 the formation of CH{sub 4} during pyrolysis and release of sulfur was included to the model. Further the formation of NO from fuel nitrogen and formation of thermal- NO were included to the model using Arrhenius type reaction rate equations. The calculated results are realistic and the model is used as a tool to find out methods to increase the efficiency and availability and decrease the emissions. Analysing the results of the earlier field study of 8 boilers showed that the furnace heat load, fuming rate, find the black liquor composition have influence on the enrichment of the potassium to the fly ash. (orig.)

Modelling the long-term consequences of a hypothetical dispersal of radioactivity in an urban area including remediation alternatives

DEFF Research Database (Denmark)

Thiessen, K.M.; Andersson, Kasper Grann; Batandjieva, B.

2009-01-01

The Urban Remediation Working Group of the International Atomic Energy Agency's EMRAS (Environmental Modelling for Radiation Safety) program was organized to address issues of remediation assessment modelling for urban areas contaminated with dispersed radionuclides. The present paper describes...... the second of two modelling exercises. This exercise was based on a hypothetical dispersal of radioactivity in an urban area from a radiological dispersal device, with reference surface contamination at selected sites used as the primary input information. Modelling endpoints for the exercise included...... radionuclide concentrations and external dose rates at specified locations, contributions to the dose rates from individual surfaces, and annual and cumulative external doses to specified reference individuals. Model predictions were performed for a "no action" situation (with no remedial measures...

THE FUNCTION OF LEGAL REASONITY IN COURT JUDGEMENT (MODEL ON FINDING THE LAW REFLECTY PANCASILA VALUE

Directory of Open Access Journals (Sweden)

Deka Rachman Budihanto

2017-09-01

Full Text Available Legal research is a process to determine the rule of law, principles of law and legal doctrines in order to address the legal issues at hand. This study using a type of normative juridical (legal research. Rechtvinding understanding in Indonesian as legal discovery (translated literally could mislead rechtvinding function is to find concrete norm to associate the relevant legal facts. Adhering to the understanding of the rechtvinding the judge in carrying out its functions prosecute a legal case can not be separated from efforts to find concrete norms to be linked to the fact the law. Furthermore, when the facts of law has no grounding norms that govern mutatis mutandis thus not regulated in the rules of positive law and customary law. Scholasticism and dialectic method is used as a support hermeneutic interpretation of legal facts to me recht construction of a new legal norm normative ideas should not be separated from Idee recht itself. Rechvinding model contained in the provisions of the Basic Law of Judicial Authority Article 1 in Conjunction with Article 5, Article 10 in conjunction with Article 50 1 for the model Rechtvinding is the approach taken by norma series is a concept of morals and justice and practices considered society as law and the criminal law model rechtvinding is also banned norma concrete (new, to assess the actions (act so that an exit permit from the actions that have not been regulated in the act so that such actions are not punished.

Transverse Crack Modeling and Validation in Rotor Systems, Including Thermal Effects

Directory of Open Access Journals (Sweden)

N. Bachschmid

2003-01-01

Full Text Available This article describes a model that allows the simulation of the static behavior of a transverse crack in a horizontal rotor under the action of weight and other possible static loads and the dynamic behavior of cracked rotating shaft. The crack breathes—that is, the mechanism of the crack's opening and closing is ruled by the stress on the cracked section exerted by the external loads. In a rotor, the stresses are time-dependent and have a period equal to the period of rotation; thus, the crack periodically breathes. An original, simplified model allows cracks of various shapes to be modeled and thermal stresses to be taken into account, as they may influence the opening and closing mechanism. The proposed method was validated by using two criteria. First the crack's breathing mechanism, simulated by the model, was compared with the results obtained by a nonlinear, threedimensional finite element model calculation, and a good agreement in the results was observed. Then the proposed model allowed the development of the equivalent cracked beam. The results of this model were compared with those obtained by the three-dimensional finite element model. Also in this case, there was a good agreement in the results.

Ultrasonographic findings of right-side colonic diverticulitis: Correlation with pathologic findings

International Nuclear Information System (INIS)

Yoon, Hoi Soo; Kim, Young Hoon; Kim, Joung Sook; Cho, Woo Ho; Lim, Sung Jig; Lee, Jin Ho; Kim, Young Duk; Cha, Soon Joo

2002-01-01

To evaluate ultrasonographic (US) findings of right-side colonic diverticulitis and to correlate them with pathologic findings. Twenty nine patients with surgically (n=7) and radiographically (n=8) proven diverticulitis in the cecum and ascending colon for the past five years were included in this study, and they all underwent US due to right lower quadrant abdominal pain. US findings were analyzed by two radiologists with a special emphasis on: (1) the presence, size, and internal echo of hypoechoic lesion bulging out from the colonic wall (thickened diverticulum), (2) changes in the adjacent cecum and ascending colon, (3) changes in the adjacent mesentery, (4) accompanying fluid collection, and (5) the presence of lymphadenopathy. US finding of 18 surgically proven patients were correlated with pathologic findings. On US, 25 of 29 patients (86.2%0 were found to have thicken diverticulum with the greater dimension of 8-20 mm (mean,, 12 mm). Wall thickening of the adjacent cecum and ascending colon was seen in 28 patients (96.5%), and 22 (75.9%) of them had eccentrically thickened wall. Comparing US findings with pathologic findings in 18 surgically proven patients, all revealed to have inflamed diverticulum on surgery, but only 15 showed thickened diverticulum on US. In 12 patients, fecalith, purulent exudates, and hemorrhage were found within diverticulum on surgery. In case of diverticulitis containing fecalith, all of their echogenecities were increased. All patients showed wall thickening of the adjacent colon and increased echogenecity of the adjacent mesentery on US. Pathologic findings of these thickened walls contained nonspecific inflammatory change and hemorrhage while the mesentery with an increased echogenecity contained purulent or hemorrhagic exudates. Ultrasonography can diagnose the right-side colonic diverticulitis when there is the presence of thickened diverticulum in the area with the thickened right side colonic wall in patients with right

Modeling of in-vessel fission product release including fuel morphology effects for severe accident analyses

International Nuclear Information System (INIS)

Suh, K.Y.

1989-10-01

A new in-vessel fission product release model has been developed and implemented to perform best-estimate calculations of realistic source terms including fuel morphology effects. The proposed bulk mass transfer correlation determines the product of fission product release and equiaxed grain size as a function of the inverse fuel temperature. The model accounts for the fuel-cladding interaction over the temperature range between 770 K and 3000 K in the steam environment. A separate driver has been developed for the in-vessel thermal hydraulic and fission product behavior models that were developed by the Department of Energy for the Modular Accident Analysis Package (MAAP). Calculational results of these models have been compared to the results of the Power Burst Facility Severe Fuel Damage tests. The code predictions utilizing the mass transfer correlation agreed with the experimentally determined fractional release rates during the course of the heatup, power hold, and cooldown phases of the high temperature transients. Compared to such conventional literature correlations as the steam oxidation model and the NUREG-0956 correlation, the mass transfer correlation resulted in lower and less rapid releases in closer agreement with the on-line and grab sample data from the Severe Fuel Damage tests. The proposed mass transfer correlation can be applied for best-estimate calculations of fission products release from the UO 2 fuel in both nominal and severe accident conditions. 15 refs., 10 figs., 2 tabs

VNM: An R Package for Finding Multiple-Objective Optimal Designs for the 4-Parameter Logistic Model

OpenAIRE

Hyun, Seung Won; Wong, Weng Kee; Yang, Yarong

2018-01-01

A multiple-objective optimal design is useful for dose-response studies because it can incorporate several objectives at the design stage. Objectives can be of varying interests and a properly constructed multiple-objective optimal design can provide user-specified efficiencies, delivering higher efficiencies for the more important objectives. In this work, we introduce the VNM package written in R for finding 3-objective locally optimal designs for the 4-parameter logistic (4PL) model widely...

Modelling in Primary School: Constructing Conceptual Models and Making Sense of Fractions

Science.gov (United States)

Shahbari, Juhaina Awawdeh; Peled, Irit

2017-01-01

This article describes sixth-grade students' engagement in two model-eliciting activities offering students the opportunity to construct mathematical models. The findings show that students utilized their knowledge of fractions including conceptual and procedural knowledge in constructing mathematical models for the given situations. Some students…

High performance computation of landscape genomic models including local indicators of spatial association.

Science.gov (United States)

Stucki, S; Orozco-terWengel, P; Forester, B R; Duruz, S; Colli, L; Masembe, C; Negrini, R; Landguth, E; Jones, M R; Bruford, M W; Taberlet, P; Joost, S

2017-09-01

With the increasing availability of both molecular and topo-climatic data, the main challenges facing landscape genomics - that is the combination of landscape ecology with population genomics - include processing large numbers of models and distinguishing between selection and demographic processes (e.g. population structure). Several methods address the latter, either by estimating a null model of population history or by simultaneously inferring environmental and demographic effects. Here we present samβada, an approach designed to study signatures of local adaptation, with special emphasis on high performance computing of large-scale genetic and environmental data sets. samβada identifies candidate loci using genotype-environment associations while also incorporating multivariate analyses to assess the effect of many environmental predictor variables. This enables the inclusion of explanatory variables representing population structure into the models to lower the occurrences of spurious genotype-environment associations. In addition, samβada calculates local indicators of spatial association for candidate loci to provide information on whether similar genotypes tend to cluster in space, which constitutes a useful indication of the possible kinship between individuals. To test the usefulness of this approach, we carried out a simulation study and analysed a data set from Ugandan cattle to detect signatures of local adaptation with samβada, bayenv, lfmm and an F ST outlier method (FDIST approach in arlequin) and compare their results. samβada - an open source software for Windows, Linux and Mac OS X available at http://lasig.epfl.ch/sambada - outperforms other approaches and better suits whole-genome sequence data processing. © 2016 The Authors. Molecular Ecology Resources Published by John Wiley & Sons Ltd.

On finding galaxy clusters with PLANCK and the spherical collapse model in different dark energy cosmologies

Energy Technology Data Exchange (ETDEWEB)

Waizmann, Jean-Claude

2010-11-24

One of the main objectives of the PLANCK mission is to perform a full-sky cluster survey based on the Sunyaev-Zel'dovich (SZ) effect, which leads to the question of how such a survey would be affected by cosmological models with a different history of structure formation than LCDM. To answer this question, I developed a fast semi-analytic approach for simulating full-sky maps of the Compton-y parameter, ready to be fed into a realistic simulation pipeline. I also implemented a filter and detection pipeline based on spherical multi-frequency matched filters, that was used to study the expected SZ cluster sample of PLANCK. It turned out that realistic samples will comprise 1000 clusters at low rate of contamination, significantly lower than originally anticipated. Driven by wrong estimates of the impact of early dark energy models on structure formation, we studied the spherical collapse model in dark energy model, finding that models with varying equation-of-state have a negligible impact on the structure formation. Yet, the different expansion history for the different models can be detected via volume effects, when counting objects in a known volume. Furthermore, it turned out that the different expansion history strongly affects the angular SZ power spectra for the various models, making them an interesting tool to distinguish and constrain alternative cosmologies. (orig.)

On finding galaxy clusters with PLANCK and the spherical collapse model in different dark energy cosmologies

International Nuclear Information System (INIS)

Waizmann, Jean-Claude

2010-01-01

One of the main objectives of the PLANCK mission is to perform a full-sky cluster survey based on the Sunyaev-Zel'dovich (SZ) effect, which leads to the question of how such a survey would be affected by cosmological models with a different history of structure formation than LCDM. To answer this question, I developed a fast semi-analytic approach for simulating full-sky maps of the Compton-y parameter, ready to be fed into a realistic simulation pipeline. I also implemented a filter and detection pipeline based on spherical multi-frequency matched filters, that was used to study the expected SZ cluster sample of PLANCK. It turned out that realistic samples will comprise 1000 clusters at low rate of contamination, significantly lower than originally anticipated. Driven by wrong estimates of the impact of early dark energy models on structure formation, we studied the spherical collapse model in dark energy model, finding that models with varying equation-of-state have a negligible impact on the structure formation. Yet, the different expansion history for the different models can be detected via volume effects, when counting objects in a known volume. Furthermore, it turned out that the different expansion history strongly affects the angular SZ power spectra for the various models, making them an interesting tool to distinguish and constrain alternative cosmologies. (orig.)

CT and MR imaging findings of xanthogranulomatous cholecystitis: correlation with pathologic findings

Energy Technology Data Exchange (ETDEWEB)

Shuto, R.; Kiyosue, H.; Komatsu, E.; Matsumoto, S.; Mori, H. [Oita Medical Univ. (Japan). Dept. of Radiology; Kawano, K. [Oita Medical Univ. (Japan). Dept. of First Surgery; Kondo, Y.; Yokoyama, S. [Oita Medical Univ. (Japan). Dept. of First Pathology

2004-03-01

The aim of this study was to evaluate CT and MRI findings in xanthogranulomatous cholecystitis (XGC) and to correlate the imaging findings with various pathologic parameters. The study included 13 patients with histopathologically confirmed XGC. The CT (n=13) and MRI (n=5) obtained in these patients were evaluated retrospectively. On CT, low-attenuation areas in the wall of XGC correlated with foam and inflammatory cells or necrosis and/or abscess in XGC. Areas of iso- to slightly high signal intensity on T2-weighted images, showing slight enhancement at early phase and strong enhancement at last phase on dynamic study, corresponded with areas of abundant xanthogranulomas. Areas with very high signal intensity on T2-weighted images without enhancement corresponded with necrosis and/or abscesses. Luminal surface enhancement (LSE) of gallbladder wall represented preservation of the epithelial layer. The early-enhanced areas of the liver bed on dynamic CT and MR images corresponded with accumulation of inflammatory cells and abundant fibrosis. Our results indicate that CT and MRI findings correlate well with the histopathologic findings of XGC.

How much complexity is warranted in a rainfall-runoff model? Findings obtained from symbolic regression, using Eureqa

Science.gov (United States)

Abrahart, R. J.; Beriro, D. J.

2012-04-01

The information content in a rainfall-runoff record is sufficient to support models of only very limited complexity (Jakeman and Hornberger, 1993). This begs the question of what limits should observed data place on the allowable complexity of rainfall-runoff models? Eureqa1 (Schmidt and Lipson, 2009) - pronounced "eureka" - is a software tool for finding equations and detecting mathematical relationships in a dataset. The challenge, for both software and modeller, is to identify, by means of symbolic regression, the simplest mathematical formulas which describe the underlying mechanisms that produced the data. It actually delivers, however, a series of preferred modelling solutions comprising one champion for each specific level of complexity i.e. related to solution enlargement involving the progressive incorporation of additional permitted factors (internal operators/ external drivers). The potential benefit of increased complexity can as a result be assessed in a rational manner. Eureqa is free to download and use; and, in the current study, has been employed to construct a set of rainfall-runoff transfer function models for the Annapolis River at Wilmot, in north-western Nova Scotia, Canada. The climatic conditions in this catchment present an interesting set of modelling challenges; daily variations and seasonal changes in temperature, snowfall and retention result in great difficulty for runoff prediction by means of a data-driven approach. Data from 10 years of daily observations are used in the present study (01/01/2000-31/12/2009): comprising [i] discharge, [ii] total rainfall (excluding snowfall), [iii] total snowfall, [iv] thickness of snow cover, and [v] maximum and [vi] minimum temperature. Precipitation occurs throughout the whole year being slightly lower during summer. Snowfall is common from November until April and rare hurricane weather may occur in autumn. The average maximum temperature is below 0 0C in January and February, but significant

Validation of lumbar spine loading from a musculoskeletal model including the lower limbs and lumbar spine.

Science.gov (United States)

Actis, Jason A; Honegger, Jasmin D; Gates, Deanna H; Petrella, Anthony J; Nolasco, Luis A; Silverman, Anne K

2018-02-08

Low back mechanics are important to quantify to study injury, pain and disability. As in vivo forces are difficult to measure directly, modeling approaches are commonly used to estimate these forces. Validation of model estimates is critical to gain confidence in modeling results across populations of interest, such as people with lower-limb amputation. Motion capture, ground reaction force and electromyographic data were collected from ten participants without an amputation (five male/five female) and five participants with a unilateral transtibial amputation (four male/one female) during trunk-pelvis range of motion trials in flexion/extension, lateral bending and axial rotation. A musculoskeletal model with a detailed lumbar spine and the legs including 294 muscles was used to predict L4-L5 loading and muscle activations using static optimization. Model estimates of L4-L5 intervertebral joint loading were compared to measured intradiscal pressures from the literature and muscle activations were compared to electromyographic signals. Model loading estimates were only significantly different from experimental measurements during trunk extension for males without an amputation and for people with an amputation, which may suggest a greater portion of L4-L5 axial load transfer through the facet joints, as facet loads are not captured by intradiscal pressure transducers. Pressure estimates between the model and previous work were not significantly different for flexion, lateral bending or axial rotation. Timing of model-estimated muscle activations compared well with electromyographic activity of the lumbar paraspinals and upper erector spinae. Validated estimates of low back loading can increase the applicability of musculoskeletal models to clinical diagnosis and treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Hardware-in-the-loop vehicle system including dynamic fuel cell model

Energy Technology Data Exchange (ETDEWEB)

Lemes, Z.; Lenhart, T.; Braun, M.; Maencher, H. [MAGNUM Automatisierungstechnik GmbH, Darmstadt (Germany)

2005-07-01

In order to reduce costs and accelerate the development of fuel cells and systems the usage of hardware-in-the-loop (HIL) testing and dynamic modelling opens new possibilities. The dynamic model of a proton exchange membrane fuel cell (PEMFC) together with a vehicle model is used to carry out a comprehensive system investigation, which allows designing and optimising the behaviour of the components and the entire fuel cell system. The set-up of a HIL system enables real time interaction between the selected hardware and the model. (orig.)

MSCT findings in a controlled bus bombing using a pig model

DEFF Research Database (Denmark)

Hansen, Nikolaj Friis

2009-01-01

and recovering relevant foreign bodies that might have been used in the bomb to inflict more damages to bystanders. The author will present MSCT findings and the injuries found at autopsy in 10 dead pigs were positioned inside the bus in a controlled explosion. This will be done in correlation to the individual...... of the findings. 3D reconstructions of the MSCT studies using the Osirix Viewer were made to visualize injuries and foreign bodies. Results of these findings will be presented to demonstrate the advantages of MSCT to aid forensic pathologists and police investigators in understanding the injury types, patterns...

Unsteady free surface flow in porous media: One-dimensional model equations including vertical effects and seepage face

Science.gov (United States)

Di Nucci, Carmine

2018-05-01

This note examines the two-dimensional unsteady isothermal free surface flow of an incompressible fluid in a non-deformable, homogeneous, isotropic, and saturated porous medium (with zero recharge and neglecting capillary effects). Coupling a Boussinesq-type model for nonlinear water waves with Darcy's law, the two-dimensional flow problem is solved using one-dimensional model equations including vertical effects and seepage face. In order to take into account the seepage face development, the system equations (given by the continuity and momentum equations) are completed by an integral relation (deduced from the Cauchy theorem). After testing the model against data sets available in the literature, some numerical simulations, concerning the unsteady flow through a rectangular dam (with an impermeable horizontal bottom), are presented and discussed.

Model for prognostication of population irradiation dose at the soil way of long-living radionuclides including in food chains

International Nuclear Information System (INIS)

Prister, B.S.; Vinogradskaya, V.D.

2009-01-01

On the basis of modern pictures of cesium and strontium ion absorption mechanisms a soil taking complex was build the kinetic model of radionuclide migration from soil to plants. Model parameter association with the agricultural chemistry properties of soil, represented by complex estimation of soil properties S e f. The example of model application for prognostication of population internal irradiation dose due to consumption of milk at the soil way of long-living radionuclides including in food chains

Smoking cessation in women: findings from qualitative research.

Science.gov (United States)

Puskar, M

1995-11-01

The purpose of this descriptive exploratory study is to describe the experience of successful smoking cessation in adult women. The convenience sample included 10 women, ages 25 to 42, who had abstained from smoking for at least 6 months but not longer than 3 years. A semistructured interview format was used to elicit descriptions of the experience of successful smoking cessation from these subjects. The interview format explored the experience, including initial contemplation, the process of quitting, and maintenance of smoking abstinence. Interviews were audiotaped, transcribed, and then analyzed using methods outlined by Miles and Huberman [1]. Four themes emerged from the data: evolving commitment to health and personal growth, being stigmatized, changing conceptualization of smoking, and smoking cessation as a relational phenomenon. These findings were consistent with Pender's Health Promotion Model and have implications for nurse practitioners who counsel women on smoking cessation.

Finding upper bounds for software failure probabilities - experiments and results

International Nuclear Information System (INIS)

Kristiansen, Monica; Winther, Rune

2005-09-01

This report looks into some aspects of using Bayesian hypothesis testing to find upper bounds for software failure probabilities. In the first part, the report evaluates the Bayesian hypothesis testing approach for finding upper bounds for failure probabilities of single software components. The report shows how different choices of prior probability distributions for a software component's failure probability influence the number of tests required to obtain adequate confidence in a software component. In the evaluation, both the effect of the shape of the prior distribution as well as one's prior confidence in the software component were investigated. In addition, different choices of prior probability distributions are discussed based on their relevance in a software context. In the second part, ideas on how the Bayesian hypothesis testing approach can be extended to assess systems consisting of multiple software components are given. One of the main challenges when assessing systems consisting of multiple software components is to include dependency aspects in the software reliability models. However, different types of failure dependencies between software components must be modelled differently. Identifying different types of failure dependencies are therefore an important condition for choosing a prior probability distribution, which correctly reflects one's prior belief in the probability for software components failing dependently. In this report, software components include both general in-house software components, as well as pre-developed software components (e.g. COTS, SOUP, etc). (Author)

Extending PSA models including ageing and asset management - 15291

International Nuclear Information System (INIS)

Martorell, S.; Marton, I.; Carlos, S.; Sanchez, A.I.

2015-01-01

This paper proposes a new approach to Ageing Probabilistic Safety Assessment (APSA) modelling, which is intended to be used to support risk-informed decisions on the effectiveness of maintenance management programs and technical specification requirements of critical equipment of Nuclear Power Plants (NPP) within the framework of the Risk Informed Decision Making according to R.G. 1.174 principles. This approach focuses on the incorporation of not only equipment ageing but also effectiveness of maintenance and efficiency of surveillance testing explicitly into APSA models and data. This methodology is applied to a motor-operated valve of the auxiliary feed water system (AFWS) of a PWR. This simple example of application focuses on a critical safety-related equipment of a NPP in order to evaluate the risk impact of considering different approaches to APSA and the combined effect of equipment ageing and maintenance and testing alternatives along NPP design life. The risk impact of several alternatives in maintenance strategy is discussed

Health and economic benefits of reducing sugar intake in the USA, including effects via non-alcoholic fatty liver disease: a microsimulation model

Science.gov (United States)

Vreman, Rick A; Goodell, Alex J; Rodriguez, Luis A; Porco, Travis C; Lustig, Robert H; Kahn, James G

2017-01-01

Objectives Excessive consumption of added sugars in the human diet has been associated with obesity, type 2 diabetes (T2D), coronary heart disease (CHD) and other elements of the metabolic syndrome. Recent studies have shown that non-alcoholic fatty liver disease (NAFLD) is a critical pathway to metabolic syndrome. This model assesses the health and economic benefits of interventions aimed at reducing intake of added sugars. Methods Using data from US National Health Surveys and current literature, we simulated an open cohort, for the period 2015–2035. We constructed a microsimulation model with Markov chains for NAFLD (including steatosis, non-alcoholic steatohepatitis (NASH), cirrhosis and hepatocellular carcinoma (HCC)), body mass index, T2D and CHD. We assessed reductions in population disease prevalence, disease-attributable disability-adjusted life years (DALYs) and costs, with interventions that reduce added sugars consumption by either 20% or 50%. Findings The model estimated that a 20% reduction in added sugars intake will reduce prevalence of hepatic steatosis, NASH, cirrhosis, HCC, obesity, T2D and CHD. Incidence of T2D and CHD would be expected to decrease by 19.9 (95% CI 12.8 to 27.0) and 9.4 (95% CI 3.1 to 15.8) cases per 100 000 people after 20 years, respectively. A 20% reduction in consumption is also projected to annually avert 0.767 million (M) DALYs (95% CI 0.757M to 0.777M) and a total of US$10.3 billion (B) (95% CI 10.2B to 10.4B) in discounted direct medical costs by 2035. These effects increased proportionally when added sugars intake were reduced by 50%. Conclusions The decrease in incidence and prevalence of disease is similar to results in other models, but averted costs and DALYs were higher, mainly due to inclusion of NAFLD and CHD. The model suggests that efforts to reduce consumption of added sugars may result in significant public health and economic benefits. PMID:28775179

Modelling the long-term consequences of a hypothetical dispersal of radioactivity in an urban area including remediation alternatives

International Nuclear Information System (INIS)

Thiessen, K.M.; Andersson, K.G.; Batandjieva, B.; Cheng, J.-J.; Hwang, W.T.; Kaiser, J.C.; Kamboj, S.; Steiner, M.; Tomas, J.; Trifunovic, D.; Yu, C.

2009-01-01

The Urban Remediation Working Group of the International Atomic Energy Agency's EMRAS (Environmental Modelling for Radiation Safety) program was organized to address issues of remediation assessment modelling for urban areas contaminated with dispersed radionuclides. The present paper describes the second of two modelling exercises. This exercise was based on a hypothetical dispersal of radioactivity in an urban area from a radiological dispersal device, with reference surface contamination at selected sites used as the primary input information. Modelling endpoints for the exercise included radionuclide concentrations and external dose rates at specified locations, contributions to the dose rates from individual surfaces, and annual and cumulative external doses to specified reference individuals. Model predictions were performed for a 'no action' situation (with no remedial measures) and for selected countermeasures. The exercise provided an opportunity for comparison of three modelling approaches, as well as a comparison of the predicted effectiveness of various countermeasures in terms of their short-term and long-term effects on predicted doses to humans.

Time-domain simulation of constitutive relations for nonlinear acoustics including relaxation for frequency power law attenuation media modeling

Science.gov (United States)

Jiménez, Noé; Camarena, Francisco; Redondo, Javier; Sánchez-Morcillo, Víctor; Konofagou, Elisa E.

2015-10-01

We report a numerical method for solving the constitutive relations of nonlinear acoustics, where multiple relaxation processes are included in a generalized formulation that allows the time-domain numerical solution by an explicit finite differences scheme. Thus, the proposed physical model overcomes the limitations of the one-way Khokhlov-Zabolotskaya-Kuznetsov (KZK) type models and, due to the Lagrangian density is implicitly included in the calculation, the proposed method also overcomes the limitations of Westervelt equation in complex configurations for medical ultrasound. In order to model frequency power law attenuation and dispersion, such as observed in biological media, the relaxation parameters are fitted to both exact frequency power law attenuation/dispersion media and also empirically measured attenuation of a variety of tissues that does not fit an exact power law. Finally, a computational technique based on artificial relaxation is included to correct the non-negligible numerical dispersion of the finite difference scheme, and, on the other hand, improve stability trough artificial attenuation when shock waves are present. This technique avoids the use of high-order finite-differences schemes leading to fast calculations. The present algorithm is especially suited for practical configuration where spatial discontinuities are present in the domain (e.g. axisymmetric domains or zero normal velocity boundary conditions in general). The accuracy of the method is discussed by comparing the proposed simulation solutions to one dimensional analytical and k-space numerical solutions.

Finding the Root Causes of Statistical Inconsistency in Community Earth System Model Output

Science.gov (United States)

Milroy, D.; Hammerling, D.; Baker, A. H.

2017-12-01

Baker et al (2015) developed the Community Earth System Model Ensemble Consistency Test (CESM-ECT) to provide a metric for software quality assurance by determining statistical consistency between an ensemble of CESM outputs and new test runs. The test has proved useful for detecting statistical difference caused by compiler bugs and errors in physical modules. However, detection is only the necessary first step in finding the causes of statistical difference. The CESM is a vastly complex model comprised of millions of lines of code which is developed and maintained by a large community of software engineers and scientists. Any root cause analysis is correspondingly challenging. We propose a new capability for CESM-ECT: identifying the sections of code that cause statistical distinguishability. The first step is to discover CESM variables that cause CESM-ECT to classify new runs as statistically distinct, which we achieve via Randomized Logistic Regression. Next we use a tool developed to identify CESM components that define or compute the variables found in the first step. Finally, we employ the application Kernel GENerator (KGEN) created in Kim et al (2016) to detect fine-grained floating point differences. We demonstrate an example of the procedure and advance a plan to automate this process in our future work.

An extended fractal growth regime in the diffusion limited aggregation including edge diffusion

Directory of Open Access Journals (Sweden)

Aritra Ghosh

2016-01-01

Full Text Available We have investigated on-lattice diffusion limited aggregation (DLA involving edge diffusion and compared the results with the standard DLA model. For both cases, we observe the existence of a crossover from the fractal to the compact regime as a function of sticking coefficient. However, our modified DLA model including edge diffusion shows an extended fractal growth regime like an earlier theoretical result using realistic growth models and physical parameters [Zhang et al., Phys. Rev. Lett. 73 (1994 1829]. While the results of Zhang et al. showed the existence of the extended fractal growth regime only on triangular but not on square lattices, we find its existence on the square lattice. There is experimental evidence of this growth regime on a square lattice. The standard DLA model cannot characterize fractal morphology as the fractal dimension (Hausdorff dimension, DH is insensitive to morphology. It also predicts DH = DP (the perimeter dimension. For the usual fractal structures, observed in growth experiments on surfaces, the perimeter dimension can differ significantly (DH ≠ DP depending on the morphology. Our modified DLA model shows minor sensitivity to this difference.

Radiographic and HRCT findings of pneumocystis carinii pneumonia

International Nuclear Information System (INIS)

Heo, Jin Sam; Kim, Kun Il; Kim, Chang Won; Park, Soon Kew; Cho, Goon Jae

1999-01-01

To analyze the radiographic and HRCT findings of Pneumocystic carinii pneumonia. We reviewed the medical records and retrospectively analysed the chest radiographs(n=31) and HRCT scans(n=17) of 31 patients with Pneumocystis carinii pneumonia who had been followed up at our institute between, 1993 and March 1998. Pneumocystis carinii pneumonia was confirmed by cytologic evaluation of sputum stained with methenamine silver(n=25) or on the basis of clinical history(n=6). The study group included 17 men and 14 women aged 28-78(average, 53.6) years. Twenty-eight patients had underlying conditions such as hematologic diseases(n=13), AIDS(n=8), malignancy(n=2), DM(n=2) and malnutrition(n=1), and three were free from underlying diseases. Twenty patients had pure Pneumocystis carinii pneumonia and 11 had combined lung diseases, namely pulmonary tuberculosis(n=4), pulmonary metastasis(n=2), bacterial pneumonia(n=2), atypical mycobacterial infection(n=1), pulmonary edema(n=1), and Kaposi' s sarcoma(n=1). Chest radiographic findings of 20 cases of pure Pneumocystis carinii pneumonia included consolidation(n=12), linear-reticular opacity(n=8), ill defined haziness(n=7), and nodules(n=6), with bilaterality in is cases and zonal predominance in ten [central(n=5), lower(n=5)]. Ancillary findings included pleural effusion(n=10), cysts(n=5), lymphadenopathy(n=4) and pneumothorax(n=1). In two patients, findings were entirely normal. HRCT findings in ten cases of pure Pneumocystis carinii pneumonia included ground-glass opacity(n=6), consolidation(n=6), linear-reticular opacity(n=8), and nodules(n=5), with bilaterallity in seven cases and zonal predominance in five [central(n=5), lower(n=2)]. Ancillary findings among these cases included pleural effusion(n=4), lymphadenopathy(n=2), cysts(n=1), and pneumothorax(n=1). HRCT findings in seven cases of Pneumocystis carinii pneumonia combined with other lung diseases included nodules(n=6), ground-glass opacity(n=5), linear-reticular opacity

Cerebral computerized tomography findings in AIDS patients

International Nuclear Information System (INIS)

Hol, P.K.; Dunlop, O.

1997-01-01

A cerebral CT was performed in 82 of 525 AIDS patients, with positive findings in 46 cases. These findings included cerebral atrophy in 28 cases, pathological demyelinisation in two, progressive multifocal leukoencephalopathy in one, toxoplasmoses in 11, lymphomas in seven, infarction in one and one subdural haematoma. The radiological findings are correlated to pathology and clinical symptoms. The authors point out the importance of these findings for correct interpretation of the CT scans. 11 refs., 7 figs., 2 tabs

Identifying Clusters with Mixture Models that Include Radial Velocity Observations

Science.gov (United States)

Czarnatowicz, Alexis; Ybarra, Jason E.

2018-01-01

The study of stellar clusters plays an integral role in the study of star formation. We present a cluster mixture model that considers radial velocity data in addition to spatial data. Maximum likelihood estimation through the Expectation-Maximization (EM) algorithm is used for parameter estimation. Our mixture model analysis can be used to distinguish adjacent or overlapping clusters, and estimate properties for each cluster.Work supported by awards from the Virginia Foundation for Independent Colleges (VFIC) Undergraduate Science Research Fellowship and The Research Experience @Bridgewater (TREB).

Experimental interstellar organic chemistry - Preliminary findings

Science.gov (United States)

Khare, B. N.; Sagan, C.

1973-01-01

Review of the results of some explicit experimental simulation of interstellar organic chemistry consisting in low-temperature high-vacuum UV irradiation of condensed simple gases known or suspected to be present in the interstellar medium. The results include the finding that acetonitrile may be present in the interstellar medium. The implication of this and other findings are discussed.

Fix my child: The importance of including siblings in clinical assessments.

Science.gov (United States)

Farnfield, Steve

2017-07-01

This study examined concordance in the attachment strategies of school-aged siblings with reference to environmental risk in terms of poverty and maltreatment. It also investigated the effect of child maltreatment and maternal mental illness on children's psychosocial functioning in terms of the Dynamic-Maturational Model of Attachment and Adaptation (DMM) including unresolved trauma and the DMM Depressed modifier. The attachment strategies of 30 sibling pairs, aged 5-14 years, were assessed using the School-age Assessment of Attachment (SAA). Unlike most previous studies, this study included siblings from large families of two to six children. The main finding was that as environmental risk increases, the diversity of sibling attachment strategies decreases with greater recourse to the DMM Type A3-6 and A/C strategies. Unlike previous studies, the highest level of concordance was found in sibling pairs with the opposite gender. Boys whose mothers had a history of mental illness were significantly more likely than girls to be assessed with the DMM-depression modifier. As danger increases, children in the same family experience more of the same childhood. Further research should focus on single case, intra-familial studies to build a systemic model of the shared environment. Research should also evaluate the effects of environmental risk compared with size of the sibling group on children's attachment strategies. The clinical implications point to the importance of assessing all children in the family using a model built around functional formulation rather than diagnosing the symptoms of a particular child.

Analytical and numerical modelling of thermoviscous shocks in their interactions in nonlinear fluids including dissipation

DEFF Research Database (Denmark)

Rasmussen, Anders Rønne; Sørensen, Mads Peter; Gaididei, Yuri Borisovich

2010-01-01

A wave equation, that governs finite amplitude acoustic disturbances in a thermoviscous Newtonian fluid, and includes nonlinear terms up to second order, is proposed. The equation preserves the Hamiltonian structure of the fundamental fluid dynamical equations in the non dissipative limit. An exact...... thermoviscous shock solution is derived. This solution is, in an overall sense, equivalent to the Taylor shock solution of the Burgers equation. However, in contrast to the Burgers equation, the model equation considered here is capable to describe waves propagating in opposite directions. Studies of head...

Analytical linear energy transfer model including secondary particles: calculations along the central axis of the proton pencil beam

International Nuclear Information System (INIS)

Marsolat, F; De Marzi, L; Mazal, A; Pouzoulet, F

2016-01-01

In proton therapy, the relative biological effectiveness (RBE) depends on various types of parameters such as linear energy transfer (LET). An analytical model for LET calculation exists (Wilkens’ model), but secondary particles are not included in this model. In the present study, we propose a correction factor, L sec , for Wilkens’ model in order to take into account the LET contributions of certain secondary particles. This study includes secondary protons and deuterons, since the effects of these two types of particles can be described by the same RBE-LET relationship. L sec was evaluated by Monte Carlo (MC) simulations using the GATE/GEANT4 platform and was defined by the ratio of the LET d distributions of all protons and deuterons and only primary protons. This method was applied to the innovative Pencil Beam Scanning (PBS) delivery systems and L sec was evaluated along the beam axis. This correction factor indicates the high contribution of secondary particles in the entrance region, with L sec values higher than 1.6 for a 220 MeV clinical pencil beam. MC simulations showed the impact of pencil beam parameters, such as mean initial energy, spot size, and depth in water, on L sec . The variation of L sec with these different parameters was integrated in a polynomial function of the L sec factor in order to obtain a model universally applicable to all PBS delivery systems. The validity of this correction factor applied to Wilkens’ model was verified along the beam axis of various pencil beams in comparison with MC simulations. A good agreement was obtained between the corrected analytical model and the MC calculations, with mean-LET deviations along the beam axis less than 0.05 keV μm −1 . These results demonstrate the efficacy of our new correction of the existing LET model in order to take into account secondary protons and deuterons along the pencil beam axis. (paper)

Radiologic findings of abdominal wall endometriosis

Energy Technology Data Exchange (ETDEWEB)

Seo, Jung Wook [Inje Univ. Ilsan Paik Hospital, Goyang (Korea, Republic of)

2003-12-01

To evaluate the imaging findings of abdominal wall endometriosis. In seven of 17 patients with surgically proven endometriosis of the abdominal wall, we retrospectively reviewed the findings of radiologic studies such as abdominal US (n=3), CT (n=4), and MRI (n=1). One patient under went more than one type of imaging, apparently. The surgical history of the seven, and their symptoms and preoperative diagnosis were reviewed, and the size, location, margin and nature of the mass, and the contrast enhancement patterns observed at radiologic studies, were assessed. The chief symptoms were palpable abdominal wall mass (n=5) and lower abdominal pain (n=2) around a surgical scar. Previous surgery included cesarean section (n=5), cesarean section with oophorectomy (n=1) and appendectomy (n=1). Masses were located in the subcutaneous fat layer (n=5) or rectus abdominis muscle (n=2), and their maximum diameter was 2.6 cm. Imaging findings, which correlated closely with the pathologic findings, included a well (n=5) or poorly marginated (n=2) solid mass, with a focal cystic area apparent in two cases. Although imaging findings of abdominal wall endometriosis may not be specific for diagnosis, the presence of a solid abdominal mass in female patients of reproductive age with a history of surgery is a diagnostic pointer.

Radiologic findings of abdominal wall endometriosis

International Nuclear Information System (INIS)

Seo, Jung Wook

2003-01-01

To evaluate the imaging findings of abdominal wall endometriosis. In seven of 17 patients with surgically proven endometriosis of the abdominal wall, we retrospectively reviewed the findings of radiologic studies such as abdominal US (n=3), CT (n=4), and MRI (n=1). One patient under went more than one type of imaging, apparently. The surgical history of the seven, and their symptoms and preoperative diagnosis were reviewed, and the size, location, margin and nature of the mass, and the contrast enhancement patterns observed at radiologic studies, were assessed. The chief symptoms were palpable abdominal wall mass (n=5) and lower abdominal pain (n=2) around a surgical scar. Previous surgery included cesarean section (n=5), cesarean section with oophorectomy (n=1) and appendectomy (n=1). Masses were located in the subcutaneous fat layer (n=5) or rectus abdominis muscle (n=2), and their maximum diameter was 2.6 cm. Imaging findings, which correlated closely with the pathologic findings, included a well (n=5) or poorly marginated (n=2) solid mass, with a focal cystic area apparent in two cases. Although imaging findings of abdominal wall endometriosis may not be specific for diagnosis, the presence of a solid abdominal mass in female patients of reproductive age with a history of surgery is a diagnostic pointer

Exergoeconomic performance optimization for a steady-flow endoreversible refrigeration model including six typical cycles

Energy Technology Data Exchange (ETDEWEB)

Chen, Lingen; Kan, Xuxian; Sun, Fengrui; Wu, Feng [College of Naval Architecture and Power, Naval University of Engineering, Wuhan 430033 (China)

2013-07-01

The operation of a universal steady flow endoreversible refrigeration cycle model consisting of a constant thermal-capacity heating branch, two constant thermal-capacity cooling branches and two adiabatic branches is viewed as a production process with exergy as its output. The finite time exergoeconomic performance optimization of the refrigeration cycle is investigated by taking profit rate optimization criterion as the objective. The relations between the profit rate and the temperature ratio of working fluid, between the COP (coefficient of performance) and the temperature ratio of working fluid, as well as the optimal relation between profit rate and the COP of the cycle are derived. The focus of this paper is to search the compromised optimization between economics (profit rate) and the utilization factor (COP) for endoreversible refrigeration cycles, by searching the optimum COP at maximum profit, which is termed as the finite-time exergoeconomic performance bound. Moreover, performance analysis and optimization of the model are carried out in order to investigate the effect of cycle process on the performance of the cycles using numerical example. The results obtained herein include the performance characteristics of endoreversible Carnot, Diesel, Otto, Atkinson, Dual and Brayton refrigeration cycles.

Fundus autofluorescence findings in a mouse model of retinal detachment.

Science.gov (United States)

Secondi, Roberta; Kong, Jian; Blonska, Anna M; Staurenghi, Giovanni; Sparrow, Janet R

2012-08-07

Fundus autofluorescence (fundus AF) changes were monitored in a mouse model of retinal detachment (RD). RD was induced by transscleral injection of hyaluronic acid (Healon) or sterile balanced salt solution (BSS) into the subretinal space of 4-5-day-old albino Abca4 null mutant and Abca4 wild-type mice. Images acquired by confocal scanning laser ophthalmoscopy (Spectralis HRA) were correlated with spectral domain optical coherence tomography (SD-OCT), infrared reflectance (IR), fluorescence spectroscopy, and histologic analysis. Results. In the area of detached retina, multiple hyperreflective spots in IR images corresponded to punctate areas of intense autofluorescence visible in fundus AF mode. The puncta exhibited changes in fluorescence intensity with time. SD-OCT disclosed undulations of the neural retina and hyperreflectivity of the photoreceptor layer that likely corresponded to histologically visible photoreceptor cell rosettes. Fluorescence emission spectra generated using flat-mounted retina, and 488 and 561 nm excitation, were similar to that of RPE lipofuscin. With increased excitation wavelength, the emission maximum shifted towards longer wavelengths, a characteristic typical of fundus autofluorescence. In detached retinas, hyper-autofluorescent spots appeared to originate from photoreceptor outer segments that were arranged within retinal folds and rosettes. Consistent with this interpretation is the finding that the autofluorescence was spectroscopically similar to the bisretinoids that constitute RPE lipofuscin. Under the conditions of a RD, abnormal autofluorescence may arise from excessive production of bisretinoid by impaired photoreceptor cells.

Ocean Dredged Material Disposal Site (ODMDS) Authorization and Short-Term FATE (STFATE) Model Analysis: 2014-2015 Working Group Findings Report

Science.gov (United States)

2016-03-01

fractions A grain size or sieve analysis typically yields the mass fraction of each particle size class after dispersing all of the material. However...ER D C TR -1 6- 2 Ocean Dredged Material Disposal Site (ODMDS) Authorization and Short-Term FATE (STFATE) Model Analysis 2014 – 2015...Term FATE (STFATE) Model Analysis 2014 – 2015 Working Group Findings Report Jase D. Ousley Coastal and Hydraulics Laboratory U.S. Army Engineer

Normal radiographic findings. 4. act. ed.

International Nuclear Information System (INIS)

Moeller, T.B.

2003-01-01

This book can serve the reader in three ways: First, it presents normal findings for all radiographic techniques including KM. Important data which are criteria of normal findings are indicated directly in the pictures and are also explained in full text and in summary form. Secondly, it teaches the systematics of interpreting a picture - how to look at it, what structures to regard in what order, and for what to look in particular. Checklists are presented in each case. Thirdly, findings are formulated in accordance with the image analysis procedure. All criteria of normal findings are defined in these formulations, which make them an important didactic element. (orig.)

Transverse Crack Modeling and Validation in Rotor Systems Including Thermal Effects

Directory of Open Access Journals (Sweden)

N. Bachschmid

2004-01-01

Full Text Available In this article, a model is described that allows one to simulate the static behavior of a transversal crack in a horizontal rotor, under the action of the weight and other possible static loads and the dynamical behavior of the rotating cracked shaft. The crack “breaths,” i.e., the mechanism of opening and closing of the crack, is ruled by the stress acting on the cracked section due to the external loads; in a rotor the stress is time-depending with a period equal to the period of rotation, thus the crack “periodically breaths.” An original simplified model is described that allows cracks of different shape to be modeled and thermal stresses to be taken into account, since they may influence the opening and closing mechanism. The proposed method has been validated using two criteria. Firstly, the crack “breathing” mechanism, simulated with the model, has been compared with the results obtained by a nonlinear 3-D FEM calculation and a good agreement in the results has been observed. Secondly, the proposed model allows the development of the equivalent cracked beam. The results of this model are compared with those obtained by the above-mentioned 3-D FEM. There is a good agreement in the results, of this case as well.

Including irrigation in niche modelling of the invasive wasp Vespula germanica (Fabricius) improves model fit to predict potential for further spread.

Science.gov (United States)

de Villiers, Marelize; Kriticos, Darren J; Veldtman, Ruan

2017-01-01

The European wasp, Vespula germanica (Fabricius) (Hymenoptera: Vespidae), is of Palaearctic origin, being native to Europe, northern Africa and Asia, and introduced into North America, Chile, Argentina, Iceland, Ascension Island, South Africa, Australia and New Zealand. Due to its polyphagous nature and scavenging behaviour, V. germanica threatens agriculture and silviculture, and negatively affects biodiversity, while its aggressive nature and venomous sting pose a health risk to humans. In areas with warmer winters and longer summers, queens and workers can survive the winter months, leading to the build-up of large nests during the following season; thereby increasing the risk posed by this species. To prevent or prepare for such unwanted impacts it is important to know where the wasp may be able to establish, either through natural spread or through introduction as a result of human transport. Distribution data from Argentina and Australia, and seasonal phenology data from Argentina were used to determine the potential distribution of V. germanica using CLIMEX modelling. In contrast to previous models, the influence of irrigation on its distribution was also investigated. Under a natural rainfall scenario, the model showed similarities to previous models. When irrigation is applied, dry stress is alleviated, leading to larger areas modelled climatically suitable compared with previous models, which provided a better fit with the actual distribution of the species. The main areas at risk of invasion by V. germanica include western USA, Mexico, small areas in Central America and in the north-western region of South America, eastern Brazil, western Russia, north-western China, Japan, the Mediterranean coastal regions of North Africa, and parts of southern and eastern Africa.

Including irrigation in niche modelling of the invasive wasp Vespula germanica (Fabricius improves model fit to predict potential for further spread.

Directory of Open Access Journals (Sweden)

Marelize de Villiers

Full Text Available The European wasp, Vespula germanica (Fabricius (Hymenoptera: Vespidae, is of Palaearctic origin, being native to Europe, northern Africa and Asia, and introduced into North America, Chile, Argentina, Iceland, Ascension Island, South Africa, Australia and New Zealand. Due to its polyphagous nature and scavenging behaviour, V. germanica threatens agriculture and silviculture, and negatively affects biodiversity, while its aggressive nature and venomous sting pose a health risk to humans. In areas with warmer winters and longer summers, queens and workers can survive the winter months, leading to the build-up of large nests during the following season; thereby increasing the risk posed by this species. To prevent or prepare for such unwanted impacts it is important to know where the wasp may be able to establish, either through natural spread or through introduction as a result of human transport. Distribution data from Argentina and Australia, and seasonal phenology data from Argentina were used to determine the potential distribution of V. germanica using CLIMEX modelling. In contrast to previous models, the influence of irrigation on its distribution was also investigated. Under a natural rainfall scenario, the model showed similarities to previous models. When irrigation is applied, dry stress is alleviated, leading to larger areas modelled climatically suitable compared with previous models, which provided a better fit with the actual distribution of the species. The main areas at risk of invasion by V. germanica include western USA, Mexico, small areas in Central America and in the north-western region of South America, eastern Brazil, western Russia, north-western China, Japan, the Mediterranean coastal regions of North Africa, and parts of southern and eastern Africa.

Mathematical modelling

CERN Document Server

2016-01-01

This book provides a thorough introduction to the challenge of applying mathematics in real-world scenarios. Modelling tasks rarely involve well-defined categories, and they often require multidisciplinary input from mathematics, physics, computer sciences, or engineering. In keeping with this spirit of modelling, the book includes a wealth of cross-references between the chapters and frequently points to the real-world context. The book combines classical approaches to modelling with novel areas such as soft computing methods, inverse problems, and model uncertainty. Attention is also paid to the interaction between models, data and the use of mathematical software. The reader will find a broad selection of theoretical tools for practicing industrial mathematics, including the analysis of continuum models, probabilistic and discrete phenomena, and asymptotic and sensitivity analysis.

Finite Element Modeling and Analysis of Nonlinear Impact and Frictional Motion Responses Including Fluid—Structure Coupling Effects

Directory of Open Access Journals (Sweden)

Yong Zhao

1997-01-01

Full Text Available A nonlinear three dimensional (3D single rack model and a nonlinear 3D whole pool multi-rack model are developed for the spent fuel storage racks of a nuclear power plant (NPP to determine impacts and frictional motion responses when subjected to 3D excitations from the supporting building floor. The submerged free standing rack system and surrounding water are coupled due to hydrodynamic fluid-structure interaction (FSI using potential theory. The models developed have features that allow consideration of geometric and material nonlinearities including (1 the impacts of fuel assemblies to rack cells, a rack to adjacent racks or pool walls, and rack support legs to the pool floor; (2 the hydrodynamic coupling of fuel assemblies with their storing racks, and of a rack with adjacent racks, pool walls, and the pool floor; and (3 the dynamic motion behavior of rocking, twisting, and frictional sliding of rack modules. Using these models 3D nonlinear time history dynamic analyses are performed per the U.S. Nuclear Regulatory Commission (USNRC criteria. Since few such modeling, analyses, and results using both the 3D single and whole pool multiple rack models are available in the literature, this paper emphasizes description of modeling and analysis techniques using the SOLVIA general purpose nonlinear finite element code. Typical response results with different Coulomb friction coefficients are presented and discussed.

Optimal design of power system stabilizer for power systems including doubly fed induction generator wind turbines

International Nuclear Information System (INIS)

Derafshian, Mehdi; Amjady, Nima

2015-01-01

This paper presents an evolutionary algorithm-based approach for optimal design of power system stabilizer (PSS) for multi-machine power systems that include doubly fed induction generator wind turbines. The proposed evolutionary algorithm is an improved particle swarm optimization named chaotic particle swarm optimization with passive congregation (CPSO-PC) applied for finding the optimal settings of PSS parameters. Two different eigenvalue-based objectives are combined as the objective function for the optimization problem of tuning PSS parameters. The first objective function comprises the damping factor of lightly damped electro-mechanical modes and the second one includes the damping ratio of these modes. The effectiveness of the proposed method to design PSS for the power systems including DFIG (Doubly Fed Induction Generator) is extensively demonstrated through eigenvalue analysis and time-domain simulations and also by comparing its simulation results with the results of other heuristic optimization approaches. - Highlights: • A new optimization model for design of PSS in power systems including DFIG is proposed. • A detailed and realistic modeling of DFIG is presented. • A new evolutionary algorithm is suggested for solving the optimization problem of designing PSS

Abdominal vascular syndromes: characteristic imaging findings

International Nuclear Information System (INIS)

Cardarelli-Leite, Leandro; Velloni, Fernanda Garozzo; Salvadori, Priscila Silveira; Lemos, Marcelo Delboni; D'Ippolito, Giuseppe

2016-01-01

Abdominal vascular syndromes are rare diseases. Although such syndromes vary widely in terms of symptoms and etiologies, certain imaging findings are characteristic. Depending on their etiology, they can be categorized as congenital - including blue rubber bleb nevus syndrome, Klippel-Trenaunay syndrome, and hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber syndrome) - compressive - including 'nutcracker' syndrome, median arcuate ligament syndrome, Cockett syndrome (also known as May-Thurner syndrome), and superior mesenteric artery syndrome. In this article, we aimed to illustrate imaging findings that are characteristic of these syndromes, through studies conducted at our institution, as well as to perform a brief review of the literature on this topic. (author)

Abdominal vascular syndromes: characteristic imaging findings

Energy Technology Data Exchange (ETDEWEB)

Cardarelli-Leite, Leandro; Velloni, Fernanda Garozzo; Salvadori, Priscila Silveira; Lemos, Marcelo Delboni; D' Ippolito, Giuseppe, E-mail: leandrocleite@gmail.com [Universidade Federal de Sao Paulo (EPM/UNIFESP), Sao Paulo, SP (Brazil). Escola Paulista de Mediciana. Departmento de Diagnostico por Imagem

2016-07-15

Abdominal vascular syndromes are rare diseases. Although such syndromes vary widely in terms of symptoms and etiologies, certain imaging findings are characteristic. Depending on their etiology, they can be categorized as congenital - including blue rubber bleb nevus syndrome, Klippel-Trenaunay syndrome, and hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber syndrome) - compressive - including 'nutcracker' syndrome, median arcuate ligament syndrome, Cockett syndrome (also known as May-Thurner syndrome), and superior mesenteric artery syndrome. In this article, we aimed to illustrate imaging findings that are characteristic of these syndromes, through studies conducted at our institution, as well as to perform a brief review of the literature on this topic. (author)

Pseudodynamic Source Characterization for Strike-Slip Faulting Including Stress Heterogeneity and Super-Shear Ruptures

KAUST Repository

Mena, B.

2012-08-08

Reliable ground‐motion prediction for future earthquakes depends on the ability to simulate realistic earthquake source models. Though dynamic rupture calculations have recently become more popular, they are still computationally demanding. An alternative is to invoke the framework of pseudodynamic (PD) source characterizations that use simple relationships between kinematic and dynamic source parameters to build physically self‐consistent kinematic models. Based on the PD approach of Guatteri et al. (2004), we propose new relationships for PD models for moderate‐to‐large strike‐slip earthquakes that include local supershear rupture speed due to stress heterogeneities. We conduct dynamic rupture simulations using stochastic initial stress distributions to generate a suite of source models in the magnitude Mw 6–8. This set of models shows that local supershear rupture speed prevails for all earthquake sizes, and that the local rise‐time distribution is not controlled by the overall fault geometry, but rather by local stress changes on the faults. Based on these findings, we derive a new set of relations for the proposed PD source characterization that accounts for earthquake size, buried and surface ruptures, and includes local rise‐time variations and supershear rupture speed. By applying the proposed PD source characterization to several well‐recorded past earthquakes, we verify that significant improvements in fitting synthetic ground motion to observed ones is achieved when comparing our new approach with the model of Guatteri et al. (2004). The proposed PD methodology can be implemented into ground‐motion simulation tools for more physically reliable prediction of shaking in future earthquakes.

HPTAM, a two-dimensional Heat Pipe Transient Analysis Model, including the startup from a frozen state

Science.gov (United States)

Tournier, Jean-Michel; El-Genk, Mohamed S.

1995-01-01

A two-dimensional Heat Pipe Transient Analysis Model, 'HPTAM,' was developed to simulate the transient operation of fully-thawed heat pipes and the startup of heat pipes from a frozen state. The model incorporates: (a) sublimation and resolidification of working fluid; (b) melting and freezing of the working fluid in the porous wick; (c) evaporation of thawed working fluid and condensation as a thin liquid film on a frozen substrate; (d) free-molecule, transition, and continuum vapor flow regimes, using the Dusty Gas Model; (e) liquid flow and heat transfer in the porous wick; and (f) thermal and hydrodynamic couplings of phases at their respective interfaces. HPTAM predicts the radius of curvature of the liquid meniscus at the liquid-vapor interface and the radial location of the working fluid level (liquid or solid) in the wick. It also includes the transverse momentum jump condition (capillary relationship of Pascal) at the liquid-vapor interface and geometrically relates the radius of curvature of the liquid meniscus to the volume fraction of vapor in the wick. The present model predicts the capillary limit and partial liquid recess (dryout) in the evaporator wick, and incorporates a liquid pooling submodel, which simulates accumulation of the excess liquid in the vapor core at the condenser end.

Microstructure modeling and crystal plasticity simulations for the evaluation of fatigue crack initiation in α-iron specimen including an elliptic defect

Energy Technology Data Exchange (ETDEWEB)

Briffod, Fabien, E-mail: briffod@rme.mm.t.u-tokyo.ac.jp; Shiraiwa, Takayuki; Enoki, Manabu

2017-05-17

In this study, fatigue crack initiation in pure α-iron is investigated through a microstructure-sensitive framework. At first, synthetic microstructures are modeled based on an anisotropic tessellation that accounts for the information of the grains morphology extracted from electron backscatter diffraction (EBSD) analysis. Low-cycle fatigue experiments under strain-controlled conditions are conducted in order to calibrate a crystal plasticity model and a J{sub 2} model including isotropic and kinematic hardening. A critical plane fatigue indicator parameter (FIP) based on the Tanaka-Mura model is then presented to evaluate the location and quantify the driving force for the formation of a crack. The FIP is averaged over several potential crack paths within each grain defined by the intersection between a given slip plane and the plane of the model thus accounting for both the lattice orientation and morphology of the grain. Several fatigue simulations at various stress amplitudes are conducted using a sub-modeling technique for the attribution of boundary conditions on the polycrystalline aggregate models including an elliptic defect. The influence of the microstructure attributes and stress level on the location and amplitude of the FIP are then quantified and discussed.

NASTRAN thermal analyzer: Theory and application including a guide to modeling engineering problems, volume 1. [thermal analyzer manual

Science.gov (United States)

Lee, H. P.

1977-01-01

The NASTRAN Thermal Analyzer Manual describes the fundamental and theoretical treatment of the finite element method, with emphasis on the derivations of the constituent matrices of different elements and solution algorithms. Necessary information and data relating to the practical applications of engineering modeling are included.

Tracer experiment data sets for the verification of local and meso-scale atmospheric dispersion models including topographic effects

International Nuclear Information System (INIS)

Sartori, E.; Schuler, W.

1992-01-01

Software and data for nuclear energy applications are acquired, tested and distributed by several information centres; in particular, relevant computer codes are distributed internationally by the OECD/NEA Data Bank (France) and by ESTSC and EPIC/RSIC (United States). This activity is coordinated among the centres and is extended outside the OECD area through an arrangement with the IAEA. This article proposes more specifically a scheme for acquiring, storing and distributing atmospheric tracer experiment data (ATE) required for verification of atmospheric dispersion models especially the most advanced ones including topographic effects and specific to the local and meso-scale. These well documented data sets will form a valuable complement to the set of atmospheric dispersion computer codes distributed internationally. Modellers will be able to gain confidence in the predictive power of their models or to verify their modelling skills. (au)

Deterministic Model for Rubber-Metal Contact Including the Interaction Between Asperities

NARCIS (Netherlands)

Deladi, E.L.; de Rooij, M.B.; Schipper, D.J.

2005-01-01

Rubber-metal contact involves relatively large deformations and large real contact areas compared to metal-metal contact. Here, a deterministic model is proposed for the contact between rubber and metal surfaces, which takes into account the interaction between neighboring asperities. In this model,

Pseudomembranous colitis: CT findings in children

International Nuclear Information System (INIS)

Blickman, J.G.; Boland, G.W.L.; Cleveland, R.H.; Bramson, R.T.; Lee, M.J.

1995-01-01

A spectrum of nodular haustral thickening and an 'accordion' pattern have been reported as specific features of pseudomembranous colitis (PMC) in adults. A retrospective review of nine patients with PMC was performed to assess whether this spectrum of CT findings also occurred in children. In four girls and five boys, CT scans were performed within 3 days of a positive stool toxin assay for Clostridium difficile. Documented CT abnormalities included nodular haustral thickening, the 'accordion' pattern, colonic wall thickening, ascites, and pericolonic edema. These results were then correlated as to their impact on the clinical outcome. Circumferential colon wall thickening was identified in 7/9 (78%) patients (mean thickening 14.5 mm). Nodular haustral thickening was identified in 4/9 (44%) and the 'accordion' pattern in 2/9 (22%). Other findings included pericolonic edema in 3/9 (33%) and ascites in 1/9 (11%). Wall thickening was confined to the left colon and rectum in 2/9 (22%), to the right colon in 2/9 (22%), and involved the whole colon in 3/9 (33%). Although CT findings associated with PMC in children may be suggestive for this diagnosis, CT is less specific than laboratory and clinical findings. (orig.)

Pseudomembranous colitis: CT findings in children

Energy Technology Data Exchange (ETDEWEB)

Blickman, J.G. [Massachusetts General Hospital, Boston, MA (United States); Boland, G.W.L. [Massachusetts General Hospital, Boston, MA (United States); Cleveland, R.H. [The Children`s Hospital, Boston, MA (United States); Bramson, R.T. [Massachusetts General Hospital, Boston, MA (United States); Lee, M.J. [Massachusetts General Hospital, Boston, MA (United States)

1995-11-01

A spectrum of nodular haustral thickening and an `accordion` pattern have been reported as specific features of pseudomembranous colitis (PMC) in adults. A retrospective review of nine patients with PMC was performed to assess whether this spectrum of CT findings also occurred in children. In four girls and five boys, CT scans were performed within 3 days of a positive stool toxin assay for Clostridium difficile. Documented CT abnormalities included nodular haustral thickening, the `accordion` pattern, colonic wall thickening, ascites, and pericolonic edema. These results were then correlated as to their impact on the clinical outcome. Circumferential colon wall thickening was identified in 7/9 (78%) patients (mean thickening 14.5 mm). Nodular haustral thickening was identified in 4/9 (44%) and the `accordion` pattern in 2/9 (22%). Other findings included pericolonic edema in 3/9 (33%) and ascites in 1/9 (11%). Wall thickening was confined to the left colon and rectum in 2/9 (22%), to the right colon in 2/9 (22%), and involved the whole colon in 3/9 (33%). Although CT findings associated with PMC in children may be suggestive for this diagnosis, CT is less specific than laboratory and clinical findings. (orig.)

Meson decays in a quark model

International Nuclear Information System (INIS)

Roberts, W.; Silvestre-Brac, B.

1998-01-01

A recent model of hadron states is extended to include meson decays. We find that the overall success of the model is quite good. Possible improvements to the model are suggested. copyright 1997 The American Physical Society

Kinetic modelling of anaerobic hydrolysis of solid wastes, including disintegration processes

Energy Technology Data Exchange (ETDEWEB)

García-Gen, Santiago [Department of Chemical Engineering, Institute of Technology, University of Santiago de Compostela, 15782 Santiago de Compostela (Spain); Sousbie, Philippe; Rangaraj, Ganesh [INRA, UR50, Laboratoire de Biotechnologie de l’Environnement, Avenue des Etangs, Narbonne F-11100 (France); Lema, Juan M. [Department of Chemical Engineering, Institute of Technology, University of Santiago de Compostela, 15782 Santiago de Compostela (Spain); Rodríguez, Jorge, E-mail: jrodriguez@masdar.ac.ae [Department of Chemical Engineering, Institute of Technology, University of Santiago de Compostela, 15782 Santiago de Compostela (Spain); Institute Centre for Water and Environment (iWater), Masdar Institute of Science and Technology, PO Box 54224 Abu Dhabi (United Arab Emirates); Steyer, Jean-Philippe; Torrijos, Michel [INRA, UR50, Laboratoire de Biotechnologie de l’Environnement, Avenue des Etangs, Narbonne F-11100 (France)

2015-01-15

Highlights: • Fractionation of solid wastes into readily and slowly biodegradable fractions. • Kinetic coefficients estimation from mono-digestion batch assays. • Validation of kinetic coefficients with a co-digestion continuous experiment. • Simulation of batch and continuous experiments with an ADM1-based model. - Abstract: A methodology to estimate disintegration and hydrolysis kinetic parameters of solid wastes and validate an ADM1-based anaerobic co-digestion model is presented. Kinetic parameters of the model were calibrated from batch reactor experiments treating individually fruit and vegetable wastes (among other residues) following a new protocol for batch tests. In addition, decoupled disintegration kinetics for readily and slowly biodegradable fractions of solid wastes was considered. Calibrated parameters from batch assays of individual substrates were used to validate the model for a semi-continuous co-digestion operation treating simultaneously 5 fruit and vegetable wastes. The semi-continuous experiment was carried out in a lab-scale CSTR reactor for 15 weeks at organic loading rate ranging between 2.0 and 4.7 g VS/L d. The model (built in Matlab/Simulink) fit to a large extent the experimental results in both batch and semi-continuous mode and served as a powerful tool to simulate the digestion or co-digestion of solid wastes.

10 CFR 51.32 - Finding of no significant impact.

Science.gov (United States)

2010-01-01

... assessment is included, the finding need not repeat any of the discussion in the assessment but may... 10 Energy 2 2010-01-01 2010-01-01 false Finding of no significant impact. 51.32 Section 51.32... Section 102(2) Finding of No Significant Impact § 51.32 Finding of no significant impact. (a) A finding of...

Mammographic and Ultrasonographic Findings of the Chemoport Insertion Site

International Nuclear Information System (INIS)

Kim, Seun Jung; Kang, Bong Joo; Cha, Eun Suk; Park, Hye Jung; Kim, Sung Hun; Choi, Jae Jeong; Lee, Ji Hye

2010-01-01

To describe mammographic and ultrasonographic findings of previous chemoport insertion sites. We included patients who had abnormal findings at chemoport insertion sites on mammography and ultrasonography from 224 patients who underwent chemoport insertion and breast imaging at our institution between January, 2005, and December, 2007. Abnormal findings were identified in 16 mammographies and 14 ultrasonographies in 10 patients. The mean age was 50.9 years and the age range was from 44 to 67 years. Abnormal findings on mammography and ultrasonography were retrospectively analyzed according to ACR/BI-RADS. All cases were followed up with imaging studies for 2 years to confirm changes after chemoport insertion. Of the abnormal findings identified on mammography, focal asymmetry (7/16) was the most common. Other abnormal findings included mass (6/16), skin retraction (2/16), residual chemoport tip (1/16), and trabecular thickening (1/16). Of the abnormal findings seen on ultrasonography, skin thickening (12/14) was the most common. Other abnormal findings included mass (5/14), diffuse increased echogenicity of subcutaneous tissue (1/14), and a localized skin nodule (1/14). Abnormal findings on mammography and ultrasonography were located in the upper outer quadrant in 5 patients, upper inner quadrant in 3 patients, and mid upper portion in 1 patient. In 1 patient, the abnormal finding was only identified in the mediolateral oblique view of her mammography. Radiologists should be aware of potential abnormal findings on mammography and ultrasonography following chemoport insertion. In particular, ultrasonography is a very useful modality for detecting skin complications after chemoport insertion

Conducting Accessible Research: Including People With Disabilities in Public Health, Epidemiological, and Outcomes Studies.

Science.gov (United States)

Rios, Dianne; Magasi, Susan; Novak, Catherine; Harniss, Mark

2016-12-01

People with disabilities are largely absent from mainstream health research. Exclusion of people with disabilities may be explicit, attributable to poorly justified exclusion criteria, or implicit, attributable to inaccessible study documents, interventions, or research measures. Meanwhile, people with disabilities experience poorer health, greater incidence of chronic conditions, and higher health care expenditure than people without disabilities. We outline our approach to "accessible research design"-research accessible to and inclusive of people with disabilities. We describe a model that includes 3 tiers: universal design, accommodations, and modifications. Through our work on several large-scale research studies, we provide pragmatic examples of accessible research design. Making efforts to include people with disabilities in public health, epidemiological, and outcomes studies will enhance the interpretability of findings for a significant patient population.

Dermoscopy Findings of Hidroacanthoma Simplex

Directory of Open Access Journals (Sweden)

Yota Sato

2014-05-01

Full Text Available Hidroacanthoma simplex (HAS, also known as intraepidermal eccrine poroma, is a rare eccrine adnexal tumor that tends to be misdiagnosed as other types of benign skin tumor, including clonal seborrheic keratosis. Notably, HAS is sometimes misdiagnosed and treated by cryosurgery as seborrheic keratosis, which could trigger the later development of porocarcinoma. Therefore, accurate diagnosis of HAS is indispensable for dermatologists to avoid the development of malignant tumors by an unsuitable treatment. In this report, we present the characteristic dermoscopy findings of HAS. Indeed, the dermoscopy findings might be related to the melanin-rich necrotic cells in the epidermis, which are quite different from dermoscopy findings of clonal seborrheic keratosis. As a previous report suggested, it is difficult for a dermatologist to differentiate HAS from clonal seborrheic keratosis by the naked eye. Our findings might be supportive for the early diagnosis of HAS.

34 CFR 303.321 - Comprehensive child find system.

Science.gov (United States)

2010-07-01

... 34 Education 2 2010-07-01 2010-07-01 false Comprehensive child find system. 303.321 Section 303... Services Identification and Evaluation § 303.321 Comprehensive child find system. (a) General. (1) Each system must include a comprehensive child find system that is consistent with part B of the Act (see 34...

Cascade Controller Including Back-stepping for Hydraulic-Mechanical Systems

DEFF Research Database (Denmark)

Choux, Martin; Hovland, Geir; Blanke, Mogens

2012-01-01

Development of a cascade controller structure including adaptive backstepping for a nonlinear hydraulic-mechanical system is considered in this paper where a dynamic friction (LuGre) model is included to obtain the necessary accuracy. The paper compares the performance of two variants of an adapt......Development of a cascade controller structure including adaptive backstepping for a nonlinear hydraulic-mechanical system is considered in this paper where a dynamic friction (LuGre) model is included to obtain the necessary accuracy. The paper compares the performance of two variants...... of an adaptive backstepping tracking controller with earlier results. The new control architecture is analysed and enhanced tracking performance is demonstrated when including the extended friction model. The complexity of the backstepping procedure is significantly reduced due to the cascade structure. Hence...

Molecular Modeling of Aerospace Polymer Matrices Including Carbon Nanotube-Enhanced Epoxy

Science.gov (United States)

Radue, Matthew S.

Carbon fiber (CF) composites are increasingly replacing metals used in major structural parts of aircraft, spacecraft, and automobiles. The current limitations of carbon fiber composites are addressed through computational material design by modeling the salient aerospace matrix materials. Molecular Dynamics (MD) models of epoxies with and without carbon nanotube (CNT) reinforcement and models of pure bismaleimides (BMIs) were developed to elucidate structure-property relationships for improved selection and tailoring of matrices. The influence of monomer functionality on the mechanical properties of epoxies is studied using the Reax Force Field (ReaxFF). From deformation simulations, the Young's modulus, yield point, and Poisson's ratio are calculated and analyzed. The results demonstrate an increase in stiffness and yield strength with increasing resin functionality. Comparison between the network structures of distinct epoxies is further advanced by the Monomeric Degree Index (MDI). Experimental validation demonstrates the MD results correctly predict the relationship in Young's moduli for all epoxies modeled. Therefore, the ReaxFF is confirmed to be a useful tool for studying the mechanical behavior of epoxies. While epoxies have been well-studied using MD, there has been no concerted effort to model cured BMI polymers due to the complexity of the network-forming reactions. A novel, adaptable crosslinking framework is developed for implementing 5 distinct cure reactions of Matrimid-5292 (a BMI resin) and investigating the network structure using MD simulations. The influence of different cure reactions and extent of curing are analyzed on the several thermo-mechanical properties such as mass density, glass transition temperature, coefficient of thermal expansion, elastic moduli, and thermal conductivity. The developed crosslinked models correctly predict experimentally observed trends for various properties. Finally, the epoxies modeled (di-, tri-, and tetra

A void ratio dependent water retention curve model including hydraulic hysteresis

Directory of Open Access Journals (Sweden)

Pasha Amin Y.

2016-01-01

Full Text Available Past experimental evidence has shown that Water Retention Curve (WRC evolves with mechanical stress and structural changes in soil matrix. Models currently available in the literature for capturing the volume change dependency of WRC are mainly empirical in nature requiring an extensive experimental programme for parameter identification which renders them unsuitable for practical applications. In this paper, an analytical model for the evaluation of the void ratio dependency of WRC in deformable porous media is presented. The approach proposed enables quantification of the dependency of WRC on void ratio solely based on the form of WRC at the reference void ratio and requires no additional parameters. The effect of hydraulic hysteresis on the evolution process is also incorporated in the model, an aspect rarely addressed in the literature. Expressions are presented for the evolution of main and scanning curves due to loading and change in the hydraulic path from scanning to main wetting/drying and vice versa as well as the WRC parameters such as air entry value, air expulsion value, pore size distribution index and slope of the scanning curve. The model is validated using experimental data on compacted and reconstituted soils subjected to various hydro-mechanical paths. Good agreement is obtained between model predictions and experimental data in all the cases considered.

Rupture of Ovarian Mature Cystic Teratoma: Computerized Tomography Findings

International Nuclear Information System (INIS)

Sebastia, C.; Sarrias, M.; Sanchez-Aliaga, E.; Quiroga, S.; Boye, R.; Alvarez-Castells, A.

2004-01-01

We present computed tomography findings of three cases of intraperitoneal rupture of ovarian mature cystic teratoma. Acute-phase radiological findings include presence of intraabdominal liquid, infiltration of mesenteric fat and calcified pelvic mass which also showed interior fatty content. Chronic-phase findings include infiltration of peritoneal fat, as well as increase in the size of adjacent ganglion due to chronic inflammatory response to histologically verified foreign bodies. Differential diagnoses between chronic and acute intraperitoneal ruptures of mature teratoma have been reviewed. (Author)

Development of numerical dispersion model for radioactive nuclei including resuspension processes

International Nuclear Information System (INIS)

Chiba, Masaru; Kurita, Susumu; Sasaki, Hidetaka

2003-01-01

Global-scale and local-scale dispersion model are developed combining to global and local scale meteorological forecasting model. By applying this system to another miner constituent such as mineral dust blowing by strong wind in arid region, this system shows very good performance to watch and predict the distribution of it. (author)

Cowichan Valley energy mapping and modelling. Report 6 - Findings and recommendations. Final report. [Vancouver Island, Canada

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-06-15

This report is the final report in a series of six reports detailing the findings from the Cowichan Valley Energy Mapping and Modelling project that was carried out from April of 2011 to March of 2012 by Ea Energy Analyses in conjunction with Geographic Resource Analysis and Science (GRAS). The driving force behind the Integrated Energy Mapping and Analysis project was the identification and analysis of a suite of pathways that the Cowichan Valley Regional District (CVRD) can utilise to increase its energy resilience, as well as reduce energy consumption and GHG emissions, with a primary focus on the residential sector. Mapping and analysis undertaken will support provincial energy and GHG reduction targets, and the suite of pathways outlined will address a CVRD internal target that calls for 75% of the region's energy within the residential sector to come from locally sourced renewables by 2050. The target has been developed as a mechanism to meet resilience and climate action target. The maps and findings produced are to be integrated as part of a regional policy framework currently under development. The present report is the final report and presents a summary of the findings of project tasks 1-5 and provides a set of recommendations to the CVRD based on the work done and with an eye towards the next steps in the energy planning process of the CVRD. (LN)

A surplus production model including environmental effects: Application to the Senegalese white shrimp stocks

Science.gov (United States)

Thiaw, Modou; Gascuel, Didier; Jouffre, Didier; Thiaw, Omar Thiom

2009-12-01

In Senegal, two stocks of white shrimp ( Penaeusnotialis) are intensively exploited, one in the north and another in the south. We used surplus production models including environmental effects to analyse their changes in abundance over the past 10 years and to estimate their Maximum Sustainable Yield (MSY) and the related fishing effort ( EMSY). First, yearly abundance indices were estimated from commercial statistics using GLM techniques. Then, two environmental indices were alternatively tested in the model: the coastal upwelling intensity from wind speeds provided by the SeaWifs database and the primary production derived from satellite infrared images of chlorophyll a. Models were fitted, with or without the environmental effect, to the 1996-2005 time series. They express stock abundance and catches as functions of the fishing effort and the environmental index (when considered). For the northern stock, fishing effort and abundance fluctuate over the period without any clear trends. The model based on the upwelling index explains 64.9% of the year-to-year variability. It shows that the stock was slightly overexploited in 2002-2003 and is now close to full exploitation. Stock abundance strongly depends on environmental conditions; consequently, the MSY estimate varies from 300 to 900 tons according to the upwelling intensity. For the southern stock, fishing effort has strongly increased over the past 10 years, while abundance has been reduced 4-fold. The environment has a significant effect on abundance but only explains a small part of the year-to-year variability. The best fit is obtained using the primary production index ( R2 = 0.75), and the stock is now significantly overfished regardless of environmental conditions. MSY varies from 1200 to 1800 tons according to environmental conditions. Finally, in northern Senegal, the upwelling is highly variable from year to year and constitutes the major factor determining productivity. In the south, hydrodynamic

A statistical model for estimation of fish density including correlation in size, space, time and between species from research survey data

DEFF Research Database (Denmark)

Nielsen, J. Rasmus; Kristensen, Kasper; Lewy, Peter

2014-01-01

Trawl survey data with high spatial and seasonal coverage were analysed using a variant of the Log Gaussian Cox Process (LGCP) statistical model to estimate unbiased relative fish densities. The model estimates correlations between observations according to time, space, and fish size and includes...

Neuroimaging findings in pediatric sports-related concussion.

Science.gov (United States)

Ellis, Michael J; Leiter, Jeff; Hall, Thomas; McDonald, Patrick J; Sawyer, Scott; Silver, Norm; Bunge, Martin; Essig, Marco

2015-09-01

The goal in this review was to summarize the results of clinical neuroimaging studies performed in patients with sports-related concussion (SRC) who were referred to a multidisciplinar ypediatric concussion program. The authors conducted a retrospective review of medical records and neuroimaging findings for all patients referred to a multidisciplinary pediatric concussion program between September 2013 and July 2014. Inclusion criteria were as follows: 1) age ≤ 19 years; and 2) physician-diagnosed SRC. All patients underwent evaluation and follow-up by the same neurosurgeon. The 2 outcomes examined in this review were the frequency of neuroimaging studies performed in this population (including CT and MRI) and the findings of those studies. Clinical indications for neuroimaging and the impact of neuroimaging findings on clinical decision making were summarized where available. This investigation was approved by the local institutional ethics review board. A total of 151 patients (mean age 14 years, 59% female) were included this study. Overall, 36 patients (24%) underwent neuroimaging studies, the results of which were normal in 78% of cases. Sixteen percent of patients underwent CT imaging; results were normal in 79% of cases. Abnormal CT findings included the following: arachnoid cyst (1 patient), skull fracture (2 patients), suspected intracranial hemorrhage (1 patient), and suspected hemorrhage into an arachnoid cyst (1 patient). Eleven percent of patients underwent MRI; results were normal in 75% of cases. Abnormal MRI findings included the following: intraparenchymal hemorrhage and sylvian fissure arachnoid cyst (1 patient); nonhemorrhagic contusion (1 patient); demyelinating disease (1 patient); and posterior fossa arachnoid cyst, cerebellar volume loss, and nonspecific white matter changes (1 patient). Results of clinical neuroimaging studies are normal in the majority of pediatric patients with SRC. However, in selected cases neuroimaging can provide

Toward the standard population synthesis model of the X-ray background: Evolution of X-ray luminosity and absorption functions of active galactic nuclei including Compton-thick populations

Energy Technology Data Exchange (ETDEWEB)

Ueda, Yoshihiro [Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan); Akiyama, Masayuki [Astronomical Institute, Tohoku University, 6-3 Aramaki, Aoba-ku, Sendai 980-8578 (Japan); Hasinger, Günther [Institute for Astronomy, 2680 Woodlawn Drive Honolulu, HI 96822-1839 (United States); Miyaji, Takamitsu [Instituto de Astronomía, Universidad Nacional Autónoma de México, Ensenada, Baja California (Mexico); Watson, Michael G. [Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom)

2014-05-10

We present the most up to date X-ray luminosity function (XLF) and absorption function of active galactic nuclei (AGNs) over the redshift range from 0 to 5, utilizing the largest, highly complete sample ever available obtained from surveys performed with Swift/BAT, MAXI, ASCA, XMM-Newton, Chandra, and ROSAT. The combined sample, including that of the Subaru/XMM-Newton Deep Survey, consists of 4039 detections in the soft (0.5-2 keV) and/or hard (>2 keV) band. We utilize a maximum likelihood method to reproduce the count rate versus redshift distribution for each survey, by taking into account the evolution of the absorbed fraction, the contribution from Compton-thick (CTK) AGNs, and broadband spectra of AGNs, including reflection components from tori based on the luminosity- and redshift-dependent unified scheme. We find that the shape of the XLF at z ∼ 1-3 is significantly different from that in the local universe, for which the luminosity-dependent density evolution model gives much better description than the luminosity and density evolution model. These results establish the standard population synthesis model of the X-ray background (XRB), which well reproduces the source counts, the observed fractions of CTK AGNs, and the spectrum of the hard XRB. The number ratio of CTK AGNs to the absorbed Compton-thin (CTN) AGNs is constrained to be ≈0.5-1.6 to produce the 20-50 keV XRB intensity within present uncertainties, by assuming that they follow the same evolution as CTN AGNs. The growth history of supermassive black holes is discussed based on the new AGN bolometric luminosity function.

Modeling the complex impacts of timber harvests to find optimal management regimes for Amazon tidal floodplain forests

Science.gov (United States)

Fortini, Lucas B.; Cropper, Wendell P.; Zarin, Daniel J.

2015-01-01

At the Amazon estuary, the oldest logging frontier in the Amazon, no studies have comprehensively explored the potential long-term population and yield consequences of multiple timber harvests over time. Matrix population modeling is one way to simulate long-term impacts of tree harvests, but this approach has often ignored common impacts of tree harvests including incidental damage, changes in post-harvest demography, shifts in the distribution of merchantable trees, and shifts in stand composition. We designed a matrix-based forest management model that incorporates these harvest-related impacts so resulting simulations reflect forest stand dynamics under repeated timber harvests as well as the realities of local smallholder timber management systems. Using a wide range of values for management criteria (e.g., length of cutting cycle, minimum cut diameter), we projected the long-term population dynamics and yields of hundreds of timber management regimes in the Amazon estuary, where small-scale, unmechanized logging is an important economic activity. These results were then compared to find optimal stand-level and species-specific sustainable timber management (STM) regimes using a set of timber yield and population growth indicators. Prospects for STM in Amazonian tidal floodplain forests are better than for many other tropical forests. However, generally high stock recovery rates between harvests are due to the comparatively high projected mean annualized yields from fast-growing species that effectively counterbalance the projected yield declines from other species. For Amazonian tidal floodplain forests, national management guidelines provide neither the highest yields nor the highest sustained population growth for species under management. Our research shows that management guidelines specific to a region’s ecological settings can be further refined to consider differences in species demographic responses to repeated harvests. In principle, such fine

Static aeroelastic analysis including geometric nonlinearities based on reduced order model

Directory of Open Access Journals (Sweden)

Changchuan Xie

2017-04-01

Full Text Available This paper describes a method proposed for modeling large deflection of aircraft in nonlinear aeroelastic analysis by developing reduced order model (ROM. The method is applied for solving the static aeroelastic and static aeroelastic trim problems of flexible aircraft containing geometric nonlinearities; meanwhile, the non-planar effects of aerodynamics and follower force effect have been considered. ROMs are computational inexpensive mathematical representations compared to traditional nonlinear finite element method (FEM especially in aeroelastic solutions. The approach for structure modeling presented here is on the basis of combined modal/finite element (MFE method that characterizes the stiffness nonlinearities and we apply that structure modeling method as ROM to aeroelastic analysis. Moreover, the non-planar aerodynamic force is computed by the non-planar vortex lattice method (VLM. Structure and aerodynamics can be coupled with the surface spline method. The results show that both of the static aeroelastic analysis and trim analysis of aircraft based on structure ROM can achieve a good agreement compared to analysis based on the FEM and experimental result.

Systemic lupus erythematosus : abdominal radiologic findings

Energy Technology Data Exchange (ETDEWEB)

Oh, Jae Cheon; Cho, On Koo; Lee, Yong Joo; Bae, Jae Ik; Kim, Yong Soo; Rhim, Hyun Chul; Ko, Byung Hee [Hanyang Univ. College of Medicine, Seoul (Korea, Republic of)

1999-06-01

Systemic lupus erythematosus(SLE) is a systemic disease of unknown etiology. Its main pathology is vasculitis and serositis, due to deposition of the immune complex or antibodies. Most findings are nonspecific ; abdominal manifestations include enteritis, hepatomegaly, pancreatic enlargement, serositis, lymphadenopathy, splenomegaly, nephritis, interstitial cystitis, and thrombophlebitis. We described radiologic findings of various organ involvement of SLE; digestive system, serosa, reticuloendothelial system, urinary system, and venous system. Diagnosis of SLE was done according to the criteria of American Rheumatism Association. Understanding of the variable imaging findings in SLE may be helpful for the early detection of abdominal involvement and complications.

CT findings of inoperable lung carcinoma

International Nuclear Information System (INIS)

Gay, S.B.; Black, W.C.

1987-01-01

CT is useful in the evaluation of patients with newly diagnosed or highly suspected lung cancer. The principal role of CT is to screen those patients with metastatic disease beyond the hili from an attempt at curative thoracotomy. While CT is regarded as very sensitive, it is not considered highly specific, and thus a surgical procedure is usually recommended for definitive diagnosis of most ''positive'' CT findings. However, the authors demonstrate a few characteristic CT findings that are highly predictive of unresectable metastatic disease. These CT findings include massive mediastinal lymphadenopathy, diffuse mediastinal infiltration, pericardial involvement, vascular encasement, and advanced chest wall invasion

Studies on CT findings and operation findings for acute appendicitis in children

International Nuclear Information System (INIS)

Sakakibara, Kenichi; Andoh, Shigemitsu; Karamatsu, Syouji; Urakami, Toshihiko; Tsuji, Hideki; Kobayashi, Tohru; Okahira, Kihiro

1995-01-01

Pediatric CT findings of acute appendicitis were reviewed retrospectively. The subjects were 29 patients (15 boys and 14 girls with an average age of 8.2 years), consisting of 17 with necrotic, 8 with phlegmonous inflammatory, and 4 with catarrhal appendicitis. CT findings were compared with the degree of inflammation. CT revealed abscess in 64.7%, 12.5%, and 0% for necrotic, phlegmonous inflammatory, and catarrhal types, respectively, and 41.4% for all types. An enlarged appendicitis was shown on CT in 86.2% (25/29). Fecalithes were shown on CT in 67.7% (19/29), which was associated with necrotic and phlegmonous inflammatory types, but not with catarrhal type. The other CT findings included thickened paramesocolon of the right lower abdomen, undefined wall of the inner side of the cecum. Inflammation was relatively slight in cases of catarrhal appendicitis, Nine patients less than 5 years of age had phlegmonous inflammatory or necrotic appendicitis. CT allowed definitive diagnosis of appendicitis in 2 of 3 patients with necrotic type. Ct was considered to be very useful in the diagnosis of appendicitis. (N.K.)

Standardized Competencies for Parenteral Nutrition Order Review and Parenteral Nutrition Preparation, Including Compounding: The ASPEN Model.

Science.gov (United States)

Boullata, Joseph I; Holcombe, Beverly; Sacks, Gordon; Gervasio, Jane; Adams, Stephen C; Christensen, Michael; Durfee, Sharon; Ayers, Phil; Marshall, Neil; Guenter, Peggi

2016-08-01

Parenteral nutrition (PN) is a high-alert medication with a complex drug use process. Key steps in the process include the review of each PN prescription followed by the preparation of the formulation. The preparation step includes compounding the PN or activating a standardized commercially available PN product. The verification and review, as well as preparation of this complex therapy, require competency that may be determined by using a standardized process for pharmacists and for pharmacy technicians involved with PN. An American Society for Parenteral and Enteral Nutrition (ASPEN) standardized model for PN order review and PN preparation competencies is proposed based on a competency framework, the ASPEN-published interdisciplinary core competencies, safe practice recommendations, and clinical guidelines, and is intended for institutions and agencies to use with their staff. © 2016 American Society for Parenteral and Enteral Nutrition.

29 CFR 99.315 - Audit findings follow-up.

Science.gov (United States)

2010-07-01

... 29 Labor 1 2010-07-01 2010-07-01 true Audit findings follow-up. 99.315 Section 99.315 Labor Office... § 99.315 Audit findings follow-up. (a) General. The auditee is responsible for follow-up and corrective... include the reference numbers the auditor assigns to audit findings under § 99.510(c). Since the summary...

Mathematical modeling of HIV prevention measures including pre-exposure prophylaxis on HIV incidence in South Korea.

Science.gov (United States)

Kim, Sun Bean; Yoon, Myoungho; Ku, Nam Su; Kim, Min Hyung; Song, Je Eun; Ahn, Jin Young; Jeong, Su Jin; Kim, Changsoo; Kwon, Hee-Dae; Lee, Jeehyun; Smith, Davey M; Choi, Jun Yong

2014-01-01

Multiple prevention measures have the possibility of impacting HIV incidence in South Korea, including early diagnosis, early treatment, and pre-exposure prophylaxis (PrEP). We investigated how each of these interventions could impact the local HIV epidemic, especially among men who have sex with men (MSM), who have become the major risk group in South Korea. A mathematical model was used to estimate the effects of each these interventions on the HIV epidemic in South Korea over the next 40 years, as compared to the current situation. We constructed a mathematical model of HIV infection among MSM in South Korea, dividing the MSM population into seven groups, and simulated the effects of early antiretroviral therapy (ART), early diagnosis, PrEP, and combination interventions on the incidence and prevalence of HIV infection, as compared to the current situation that would be expected without any new prevention measures. Overall, the model suggested that the most effective prevention measure would be PrEP. Even though PrEP effectiveness could be lessened by increased unsafe sex behavior, PrEP use was still more beneficial than the current situation. In the model, early diagnosis of HIV infection was also effectively decreased HIV incidence. However, early ART did not show considerable effectiveness. As expected, it would be most effective if all interventions (PrEP, early diagnosis and early treatment) were implemented together. This model suggests that PrEP and early diagnosis could be a very effective way to reduce HIV incidence in South Korea among MSM.

An investigation of FLUENT's fan model including the effect of swirl velocity

International Nuclear Information System (INIS)

El Saheli, A.; Barron, R.M.

2002-01-01

The purpose of this paper is to investigate and discuss the reliability of simplified models for the computational fluid dynamics (CFD) simulation of air flow through automotive engine cooling fans. One of the most widely used simplified fan models in industry is a variant of the actuator disk model which is available in most commercial CFD software, such as FLUENT. In this model, the fan is replaced by an infinitely thin surface on which pressure rise across the fan is specified as a polynomial function of normal velocity or flow rate. The advantages of this model are that it is simple, it accurately predicts the pressure rise through the fan and the axial velocity, and it is robust

16 CFR 1303.5 - Findings.

Science.gov (United States)

2010-01-01

... Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS BAN OF LEAD-CONTAINING PAINT AND CERTAIN CONSUMER PRODUCTS BEARING LEAD-CONTAINING PAINT § 1303.5 Findings. (a) The degree and... that this syndrome may include hyperactivity, impulsive behavior, prolonged reaction time, perceptual...

METHODS OF FINDING BUSINESS PARTNERS OF MANUFACTURING FIRMS IN JAPAN

Directory of Open Access Journals (Sweden)

Nobuhiro Takahashi

2017-09-01

Full Text Available This paper addresses new methods of finding business partners for joint development in Japan. These methods create opportunities for a manufacturing firm, which has excellent technology, to find an appropriate business partner. We call these methods the Osaka model. In the model, a company finds a business partner among plenty of companies, while they establish mutual trust and solve higher levels of technological difficulties. The model shares strong points of both spot transaction and conventional co-development. In other words, this model takes advantages of both Western style and Japanese style inter-business relationship. This paper also argues the environment for encouraging the model. The area should be a place where you can obtain many sources of information. Increasing meetings or facilities on specific themes is an effective method to encourage the model in the area. In addition, a database with which each technological seed has been already arranged with their technological needs is beneficial for matching them. If such a database becomes a shared knowledge in the area, the model would be promoted.

Including lateral interactions into microkinetic models of catalytic reactions

DEFF Research Database (Denmark)

Hellman, Anders; Honkala, Johanna Karoliina

2007-01-01

In many catalytic reactions lateral interactions between adsorbates are believed to have a strong influence on the reaction rates. We apply a microkinetic model to explore the effect of lateral interactions and how to efficiently take them into account in a simple catalytic reaction. Three differ...... different approximations are investigated: site, mean-field, and quasichemical approximations. The obtained results are compared to accurate Monte Carlo numbers. In the end, we apply the approximations to a real catalytic reaction, namely, ammonia synthesis....

FINDING POTENTIALLY UNSAFE NUTRITIONAL SUPPLEMENTS FROM USER REVIEWS WITH TOPIC MODELING.

Science.gov (United States)

Sullivan, Ryan; Sarker, Abeed; O'Connor, Karen; Goodin, Amanda; Karlsrud, Mark; Gonzalez, Graciela

2016-01-01

Although dietary supplements are widely used and generally are considered safe, some supplements have been identified as causative agents for adverse reactions, some of which may even be fatal. The Food and Drug Administration (FDA) is responsible for monitoring supplements and ensuring that supplements are safe. However, current surveillance protocols are not always effective. Leveraging user-generated textual data, in the form of Amazon.com reviews for nutritional supplements, we use natural language processing techniques to develop a system for the monitoring of dietary supplements. We use topic modeling techniques, specifically a variation of Latent Dirichlet Allocation (LDA), and background knowledge in the form of an adverse reaction dictionary to score products based on their potential danger to the public. Our approach generates topics that semantically capture adverse reactions from a document set consisting of reviews posted by users of specific products, and based on these topics, we propose a scoring mechanism to categorize products as "high potential danger", "average potential danger" and "low potential danger." We evaluate our system by comparing the system categorization with human annotators, and we find that the our system agrees with the annotators 69.4% of the time. With these results, we demonstrate that our methods show promise and that our system represents a proof of concept as a viable low-cost, active approach for dietary supplement monitoring.

Findings from three South African studies

African Journals Online (AJOL)

Adele

Findings from three South African studies. BA Robertson. Emeritus Professor, Department of Psychiatry and Mental Health, University of Cape Town, ... heterogeneous presentation including elements of anxiety, .... Washington: APA, 1994. 4.

Development of Fuzzy Logic Forecast Models for Location-Based Parking Finding Services

Directory of Open Access Journals (Sweden)

Zhirong Chen

2013-01-01

Full Text Available Park-and-ride (PnR facilities provided by Australian transport authorities have been an effective way to encourage car drivers to use public transport such as trains and buses. However, as populations grow and vehicle running costs increase, the demand for more parking spaces has escalated. Often, PnR facilities are filled to capacity by early morning and commuters resort to parking illegally in streets surrounding stations. This paper reports on the development of a location-based parking finding service for PnR users. Based on their current location, the system can inform users which is the best station to park their cars during peak period. Two criteria—parking availability and the shortest travel time—were used to evaluate the best station. Fuzzy logic forecast models were used to estimate the uncertainty of parking availability during the peak parking demand period. A prototype using these methods has been developed based on a case study of the Oats Street and Carlisle PnR facilities in Perth, Western Australia. The system has proved to be efficacious and has the potential to be applied to other parking systems.

Measurement network design including traveltime determinations to minimize model prediction uncertainty

NARCIS (Netherlands)

Janssen, G.M.C.M.; Valstar, J.R.; Zee, van der S.E.A.T.M.

2008-01-01

Traveltime determinations have found increasing application in the characterization of groundwater systems. No algorithms are available, however, to optimally design sampling strategies including this information type. We propose a first-order methodology to include groundwater age or tracer arrival

Multi-jet merged top-pair production including electroweak corrections

Science.gov (United States)

Gütschow, Christian; Lindert, Jonas M.; Schönherr, Marek

2018-04-01

We present theoretical predictions for the production of top-quark pairs in association with jets at the LHC including electroweak (EW) corrections. First, we present and compare differential predictions at the fixed-order level for t\\bar{t} and t\\bar{t}+ {jet} production at the LHC considering the dominant NLO EW corrections of order O(α_{s}^2 α ) and O(α_{s}^3 α ) respectively together with all additional subleading Born and one-loop contributions. The NLO EW corrections are enhanced at large energies and in particular alter the shape of the top transverse momentum distribution, whose reliable modelling is crucial for many searches for new physics at the energy frontier. Based on the fixed-order results we motivate an approximation of the EW corrections valid at the percent level, that allows us to readily incorporate the EW corrections in the MePs@Nlo framework of Sherpa combined with OpenLoops. Subsequently, we present multi-jet merged parton-level predictions for inclusive top-pair production incorporating NLO QCD + EW corrections to t\\bar{t} and t\\bar{t}+ {jet}. Finally, we compare at the particle-level against a recent 8 TeV measurement of the top transverse momentum distribution performed by ATLAS in the lepton + jet channel. We find very good agreement between the Monte Carlo prediction and the data when the EW corrections are included.

Prediction of preterm birth in multiple pregnancies: development of a multivariable model including cervical length measurement at 16 to 21 weeks' gestation.

Science.gov (United States)

van de Mheen, Lidewij; Schuit, Ewoud; Lim, Arianne C; Porath, Martina M; Papatsonis, Dimitri; Erwich, Jan J; van Eyck, Jim; van Oirschot, Charlotte M; Hummel, Piet; Duvekot, Johannes J; Hasaart, Tom H M; Groenwold, Rolf H H; Moons, Karl G M; de Groot, Christianne J M; Bruinse, Hein W; van Pampus, Maria G; Mol, Ben W J

2014-04-01

To develop a multivariable prognostic model for the risk of preterm delivery in women with multiple pregnancy that includes cervical length measurement at 16 to 21 weeks' gestation and other variables. We used data from a previous randomized trial. We assessed the association between maternal and pregnancy characteristics including cervical length measurement at 16 to 21 weeks' gestation and time to delivery using multivariable Cox regression modelling. Performance of the final model was assessed for the outcomes of preterm and very preterm delivery using calibration and discrimination measures. We studied 507 women, of whom 270 (53%) delivered models for preterm and very preterm delivery had a c-index of 0.68 (95% CI 0.63 to 0.72) and 0.68 (95% CI 0.62 to 0.75), respectively, and showed good calibration. In women with a multiple pregnancy, the risk of preterm delivery can be assessed with a multivariable model incorporating cervical length and other predictors.

A comparison of different ways of including baseline counts in negative binomial models for data from falls prevention trials.

Science.gov (United States)

Zheng, Han; Kimber, Alan; Goodwin, Victoria A; Pickering, Ruth M

2018-01-01

A common design for a falls prevention trial is to assess falling at baseline, randomize participants into an intervention or control group, and ask them to record the number of falls they experience during a follow-up period of time. This paper addresses how best to include the baseline count in the analysis of the follow-up count of falls in negative binomial (NB) regression. We examine the performance of various approaches in simulated datasets where both counts are generated from a mixed Poisson distribution with shared random subject effect. Including the baseline count after log-transformation as a regressor in NB regression (NB-logged) or as an offset (NB-offset) resulted in greater power than including the untransformed baseline count (NB-unlogged). Cook and Wei's conditional negative binomial (CNB) model replicates the underlying process generating the data. In our motivating dataset, a statistically significant intervention effect resulted from the NB-logged, NB-offset, and CNB models, but not from NB-unlogged, and large, outlying baseline counts were overly influential in NB-unlogged but not in NB-logged. We conclude that there is little to lose by including the log-transformed baseline count in standard NB regression compared to CNB for moderate to larger sized datasets. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Find an NCI-Designated Cancer Center

Science.gov (United States)

Find the locations of NCI-designated cancer centers by area, region, state, or name that includes contact information to help health care providers and cancer patients with referrals to clinical trials.

MR findings of craniopharyngioma

International Nuclear Information System (INIS)

Lee, Sung Moon; Woo, Young Hoon; Joo, Yang Goo; Suh, Soo Jhi

1992-01-01

Craniopharyngioma is a benign, slow-growing tumor that constitues 3-9% of all intracranial tumors, and arises from epithelial remnants of the Rathke's pouch. We analyzed MR (2.0T) findings of ten cases with surgically proved craniopharyngioma retrospectively. CT was available in five cases, and Gd-DTPA was used in six cases. Characteristic findings of craniopharyngioma in MRI included multilocularity and variable signal intensities within each loculus that were more prominent in T1WI. Detection rate of calcification in MR was 60%. Six cases with Gd-DTPA enhancement revealed irregular or rim-like enhancement. MRI provides useful information regarding the location, extent and biochemical characteristics of the oraniopharyngioma as well as its relationship to the neighboring structures which will be valuable in planning surgical resection

The genetics of auricular development and malformation: new findings in model systems driving future directions for microtia research

Science.gov (United States)

Cox, Timothy C.; Camci, Esra D.; Vora, Siddharth; Luquetti, Daniela V.; Turner, Eric E.

2014-01-01

Microtia is a term used to describe a wide array of phenotypic presentations of the outer ear. Although the majority of the cases are isolated in nature, much of our understanding of the causes of microtia has been driven by the identification of genes underlying syndromic forms where the anomaly co-presents with various other craniofacial and extra-craniofacial structural defects. In this review we discuss recent findings in mice deficient in Hoxa2, a key regulator of branchial arch patterning, which has necessitated a revision to the canonical model of pinna morphogenesis. The revised model will likely impact current classification schemes for microtia and, as we argue in this review, the interpretation of the developmental basis for various auricular malformations. In addition, we highlight recent studies in other mammalian species that are providing the first clues as to possible causes of at least some isolated anomalies and thus should now accelerate the search for the more elusive genetic contributions to the many isolated and non-syndromic cases of microtia. These findings, together with the application of new genome-level sequencing technologies and more thorough quantitative assessment of available mutant mouse resources, promise an exciting future for genetic studies in microtia. PMID:24880027

A new mammalian circadian oscillator model including the cAMP module

International Nuclear Information System (INIS)

Jun-Wei, Wang; Tian-Shou, Zhou

2009-01-01

In this paper, we develop a new mathematical model for the mammalian circadian clock, which incorporates both transcriptional/translational feedback loops (TTFLs) and a cAMP-mediated feedback loop. The model shows that TTFLs and cAMP signalling cooperatively drive the circadian rhythms. It reproduces typical experimental observations with qualitative similarities, e.g. circadian oscillations in constant darkness and entrainment to light–dark cycles. In addition, it can explain the phenotypes of cAMP-mutant and Rev-erbα −/− -mutant mice, and help us make an experimentally-testable prediction: oscillations may be rescued when arrhythmic mice with constitutively low concentrations of cAMP are crossed with Rev-erbα −/− mutant mice. The model enhances our understanding of the mammalian circadian clockwork from the viewpoint of the entire cell. (cross-disciplinary physics and related areas of science and technology)

Impact of including surface currents on simulation of Indian Ocean variability with the POAMA coupled model

Energy Technology Data Exchange (ETDEWEB)

Zhao, Mei; Wang, Guomin; Hendon, Harry H.; Alves, Oscar [Bureau of Meteorology, Centre for Australian Weather and Climate Research, Melbourne (Australia)

2011-04-15

Impacts on the coupled variability of the Indo-Pacific by including the effects of surface currents on surface stress are explored in four extended integrations of an experimental version of the Bureau of Meteorology's coupled seasonal forecast model POAMA. The first pair of simulations differs only in their treatment of momentum coupling: one version includes the effects of surface currents on the surface stress computation and the other does not. The version that includes the effect of surface currents has less mean-state bias in the equatorial Pacific cold tongue but produces relatively weak coupled variability in the Tropics, especially that related to the Indian Ocean dipole (IOD) and El Nino/Southern Oscillation (ENSO). The version without the effects of surface currents has greater bias in the Pacific cold tongue but stronger IOD and ENSO variability. In order to diagnose the role of changes in local coupling from changes in remote forcing by ENSO for causing changes in IOD variability, a second set of simulations is conducted where effects of surface currents are included only in the Indian Ocean and only in the Pacific Ocean. IOD variability is found to be equally reduced by inclusion of the local effects of surface currents in the Indian Ocean and by the reduction of ENSO variability as a result of including effects of surface currents in the Pacific. Some implications of these results for predictability of the IOD and its dependence on ENSO, and for ocean subsurface data assimilation are discussed. (orig.)

International Epidemiology of Child and Adolescent Psychopathology II: Integration and Applications of Dimensional Findings from 44 Societies

Science.gov (United States)

Rescorla, Leslie; Ivanova, Masha Y.; Achenbach, Thomas M.; Begovac, Ivan; Chahed, Myriam; Drugli, May Britt; Emerich, Deisy Ribas; Fung, Daniel S. S.; Haider, Mariam; Hansson, Kjell; Hewitt, Nohelia; Jaimes, Stefanny; Larsson, Bo; Maggiolini, Alfio; Markovic, Jasminka; Mitrovic, Dragan; Moreira, Paulo; Oliveira, Joao Tiago; Olsson, Martin; Ooi, Yoon Phaik; Petot, Djaouida; Pisa, Cecilia; Pomalima, Rolando; da Rocha; Marina Monzani; Rudan, Vlasta; Sekulic, Slobodan; Shahini, Mimoza; de Mattos Silvares, Edwiges Ferreira; Szirovicza, Lajos; Valverde, Jose; Vera, Luis Anderssen; Villa, Maria Clara; Viola, Laura; Woo, Bernadine S. C.; Zhang, Eugene Yuqing

2012-01-01

Objective: To build on Achenbach, Rescorla, and Ivanova (2012) by (a) reporting new international findings for parent, teacher, and self-ratings on the Child Behavior Checklist, Youth Self-Report, and Teacher's Report Form; (b) testing the fit of syndrome models to new data from 17 societies, including previously underrepresented regions; (c)…

Dynamic model including piping acoustics of a centrifugal compression system

NARCIS (Netherlands)

Helvoirt, van J.; Jager, de A.G.

2007-01-01

This paper deals with low frequency pulsation phenomena in full-scale centrifugal compression systems associated with compressor surge. The Greitzer lumped parameter model is applied to describe the dynamic behavior of an industrial compressor test rig and experimental evidence is provided for the

The Expanded FindCore Method for Identification of a Core Atom Set for Assessment of Protein Structure Prediction

Science.gov (United States)

Snyder, David A.; Grullon, Jennifer; Huang, Yuanpeng J.; Tejero, Roberto; Montelione, Gaetano T.

2014-01-01

Maximizing the scientific impact of NMR-based structure determination requires robust and statistically sound methods for assessing the precision of NMR-derived structures. In particular, a method to define a core atom set for calculating superimpositions and validating structure predictions is critical to the use of NMR-derived structures as targets in the CASP competition. FindCore (D.A. Snyder and G.T. Montelione PROTEINS 2005;59:673–686) is a superimposition independent method for identifying a core atom set, and partitioning that set into domains. However, as FindCore optimizes superimposition by sensitively excluding not-well-defined atoms, the FindCore core may not comprise all atoms suitable for use in certain applications of NMR structures, including the CASP assessment process. Adapting the FindCore approach to assess predicted models against experimental NMR structures in CASP10 required modification of the FindCore method. This paper describes conventions and a standard protocol to calculate an “Expanded FindCore” atom set suitable for validation and application in biological and biophysical contexts. A key application of the Expanded FindCore method is to identify a core set of atoms in the experimental NMR structure for which it makes sense to validate predicted protein structure models. We demonstrate the application of this Expanded FindCore method in characterizing well-defined regions of 18 NMR-derived CASP10 target structures. The Expanded FindCore protocol defines “expanded core atom sets” that match an expert’s intuition of which parts of the structure are sufficiently well-defined to use in assessing CASP model predictions. We also illustrate the impact of this analysis on the CASP GDT assessment scores. PMID:24327305

Predictive value of radiographic findings in gastritis

International Nuclear Information System (INIS)

Remley, K.B.; Mann, F.A.; Simons, M.A.

1986-01-01

In a retrospective review of biphasic upper gastrointestinal (GI) tract examinations in 300 consecutive patients with abdominal pain, blood loss, nausea and vomiting, weight loss or dysphagia, the author evaluated the frequency of radiographic findings suggestive of gastritis. Forty-eight patients had undergone endoscopy within 1 week of upper GI tract examination. ''Best findings'' were defined by receiver operating characteristic wave analysis of individual findings, including aphthous lesions, serrated or nodular folds, marginal spiculation, and luminal constriction. Most false negative studies were in the fundus or proximal body; most false positive studies were in the antrum. They present a pictorial dictionary of findings and data for use of ''best findings'' to improve sensitivity and specificity in the diagnosis of gastritis

3-D FEM Modeling of fiber/matrix interface debonding in UD composites including surface effects

International Nuclear Information System (INIS)

Pupurs, A; Varna, J

2012-01-01

Fiber/matrix interface debond growth is one of the main mechanisms of damage evolution in unidirectional (UD) polymer composites. Because for polymer composites the fiber strain to failure is smaller than for the matrix multiple fiber breaks occur at random positions when high mechanical stress is applied to the composite. The energy released due to each fiber break is usually larger than necessary for the creation of a fiber break therefore a partial debonding of fiber/matrix interface is typically observed. Thus the stiffness reduction of UD composite is contributed both from the fiber breaks and from the interface debonds. The aim of this paper is to analyze the debond growth in carbon fiber/epoxy and glass fiber/epoxy UD composites using fracture mechanics principles by calculation of energy release rate G II . A 3-D FEM model is developed for calculation of energy release rate for fiber/matrix interface debonds at different locations in the composite including the composite surface region where the stress state differs from the one in the bulk composite. In the model individual partially debonded fiber is surrounded by matrix region and embedded in a homogenized composite.

Finding the chiral gravitational wave background of an axion-S U (2 ) inflationary model using CMB observations and laser interferometers

Science.gov (United States)

Thorne, Ben; Fujita, Tomohiro; Hazumi, Masashi; Katayama, Nobuhiko; Komatsu, Eiichiro; Shiraishi, Maresuke

2018-02-01

A detection of B-mode polarization of the cosmic microwave background (CMB) anisotropies would confirm the presence of a primordial gravitational wave background (GWB). In the inflation paradigm, this would be an unprecedented probe of the energy scale of inflation as it is directly proportional to the power spectrum of the GWB. However, similar tensor perturbations can be produced by the matter fields present during inflation, breaking the simple relationship between energy scale and the tensor-to-scalar ratio r . It is therefore important to find ways of distinguishing between the generation mechanisms of the GWB. Without doing a full model selection, we analyze the detectability of a new axion-S U (2 ) gauge field model by calculating the signal-to-noise ratio of future CMB and interferometer observations sensitive to the chirality of the tensor spectrum. We forecast the detectability of the resulting CMB temperature and B-mode (TB) or E-mode and B-mode (EB) cross-correlation by the LiteBIRD satellite, considering the effects of residual foregrounds, gravitational lensing, and assess the ability of such an experiment to jointly detect primordial TB and EB spectra and self-calibrate its polarimeter. We find that LiteBIRD will be able to detect the chiral signal for r*>0.03 , with r* denoting the tensor-to-scalar ratio at the peak scale, and that the maximum signal-to-noise ratio for r*advanced stage of a LISA-like mission, which is designed to be sensitive to the intensity and polarization of the GWB. We find that such experiments would complement CMB observations as they would be able to detect the chirality of the GWB with high significance on scales inaccessible to the CMB. We conclude that CMB two-point statistics are limited in their ability to distinguish this model from a conventional vacuum fluctuation model of GWB generation, due to the fundamental limits on their sensitivity to parity violation. In order to test the predictions of such a model as

Normal radiographic findings. 4. act. ed.; Roentgennormalbefunde

Energy Technology Data Exchange (ETDEWEB)

Moeller, T.B. [Gemeinschaftspraxis fuer Radiologie und Nuklearmedizin, Dillingen (Germany)

2003-07-01

This book can serve the reader in three ways: First, it presents normal findings for all radiographic techniques including KM. Important data which are criteria of normal findings are indicated directly in the pictures and are also explained in full text and in summary form. Secondly, it teaches the systematics of interpreting a picture - how to look at it, what structures to regard in what order, and for what to look in particular. Checklists are presented in each case. Thirdly, findings are formulated in accordance with the image analysis procedure. All criteria of normal findings are defined in these formulations, which make them an important didactic element. (orig.)

MetaFIND: A feature analysis tool for metabolomics data

Directory of Open Access Journals (Sweden)

Cunningham Pádraig

2008-11-01

Full Text Available Abstract Background Metabolomics, or metabonomics, refers to the quantitative analysis of all metabolites present within a biological sample and is generally carried out using NMR spectroscopy or Mass Spectrometry. Such analysis produces a set of peaks, or features, indicative of the metabolic composition of the sample and may be used as a basis for sample classification. Feature selection may be employed to improve classification accuracy or aid model explanation by establishing a subset of class discriminating features. Factors such as experimental noise, choice of technique and threshold selection may adversely affect the set of selected features retrieved. Furthermore, the high dimensionality and multi-collinearity inherent within metabolomics data may exacerbate discrepancies between the set of features retrieved and those required to provide a complete explanation of metabolite signatures. Given these issues, the latter in particular, we present the MetaFIND application for 'post-feature selection' correlation analysis of metabolomics data. Results In our evaluation we show how MetaFIND may be used to elucidate metabolite signatures from the set of features selected by diverse techniques over two metabolomics datasets. Importantly, we also show how MetaFIND may augment standard feature selection and aid the discovery of additional significant features, including those which represent novel class discriminating metabolites. MetaFIND also supports the discovery of higher level metabolite correlations. Conclusion Standard feature selection techniques may fail to capture the full set of relevant features in the case of high dimensional, multi-collinear metabolomics data. We show that the MetaFIND 'post-feature selection' analysis tool may aid metabolite signature elucidation, feature discovery and inference of metabolic correlations.

Noncardiac findings on cardiac CT. Part II: spectrum of imaging findings.

LENUS (Irish Health Repository)

Killeen, Ronan P

2012-02-01

Cardiac computed tomography (CT) has evolved into an effective imaging technique for the evaluation of coronary artery disease in selected patients. Two distinct advantages over other noninvasive cardiac imaging methods include its ability to directly evaluate the coronary arteries and to provide a unique opportunity to evaluate for alternative diagnoses by assessing the extracardiac structures, such as the lungs and mediastinum, particularly in patients presenting with the chief symptom of acute chest pain. Some centers reconstruct a small field of view (FOV) cropped around the heart but a full FOV (from skin to skin in the area irradiated) is obtainable in the raw data of every scan so that clinically relevant noncardiac findings are identifiable. Debate in the scientific community has centered on the necessity for this large FOV. A review of noncardiac structures provides the opportunity to make alternative diagnoses that may account for the patient\\'s presentation or to detect important but clinically silent problems such as lung cancer. Critics argue that the yield of biopsy-proven cancers is low and that the follow-up of incidental noncardiac findings is expensive, resulting in increased radiation exposure and possibly unnecessary further testing. In this 2-part review we outline the issues surrounding the concept of the noncardiac read, looking for noncardiac findings on cardiac CT. Part I focused on the pros and cons for and against the practice of identifying noncardiac findings on cardiac CT. Part II illustrates the imaging spectrum of cardiac CT appearances of benign and malignant noncardiac pathology.

Extensions of the Rosner-Colditz breast cancer prediction model to include older women and type-specific predicted risk.

Science.gov (United States)

Glynn, Robert J; Colditz, Graham A; Tamimi, Rulla M; Chen, Wendy Y; Hankinson, Susan E; Willett, Walter W; Rosner, Bernard

2017-08-01

A breast cancer risk prediction rule previously developed by Rosner and Colditz has reasonable predictive ability. We developed a re-fitted version of this model, based on more than twice as many cases now including women up to age 85, and further extended it to a model that distinguished risk factor prediction of tumors with different estrogen/progesterone receptor status. We compared the calibration and discriminatory ability of the original, the re-fitted, and the type-specific models. Evaluation used data from the Nurses' Health Study during the period 1980-2008, when 4384 incident invasive breast cancers occurred over 1.5 million person-years. Model development used two-thirds of study subjects and validation used one-third. Predicted risks in the validation sample from the original and re-fitted models were highly correlated (ρ = 0.93), but several parameters, notably those related to use of menopausal hormone therapy and age, had different estimates. The re-fitted model was well-calibrated and had an overall C-statistic of 0.65. The extended, type-specific model identified several risk factors with varying associations with occurrence of tumors of different receptor status. However, this extended model relative to the prediction of any breast cancer did not meaningfully reclassify women who developed breast cancer to higher risk categories, nor women remaining cancer free to lower risk categories. The re-fitted Rosner-Colditz model has applicability to risk prediction in women up to age 85, and its discrimination is not improved by consideration of varying associations across tumor subtypes.

Extending a configuration model to find communities in complex networks

International Nuclear Information System (INIS)

Jin, Di; Hu, Qinghua; He, Dongxiao; Yang, Bo; Baquero, Carlos

2013-01-01

Discovery of communities in complex networks is a fundamental data analysis task in various domains. Generative models are a promising class of techniques for identifying modular properties from networks, which has been actively discussed recently. However, most of them cannot preserve the degree sequence of networks, which will distort the community detection results. Rather than using a blockmodel as most current works do, here we generalize a configuration model, namely, a null model of modularity, to solve this problem. Towards decomposing and combining sub-graphs according to the soft community memberships, our model incorporates the ability to describe community structures, something the original model does not have. Also, it has the property, as with the original model, that it fixes the expected degree sequence to be the same as that of the observed network. We combine both the community property and degree sequence preserving into a single unified model, which gives better community results compared with other models. Thereafter, we learn the model using a technique of nonnegative matrix factorization and determine the number of communities by applying consensus clustering. We test this approach both on synthetic benchmarks and on real-world networks, and compare it with two similar methods. The experimental results demonstrate the superior performance of our method over competing methods in detecting both disjoint and overlapping communities. (paper)

CT and MRI normal findings

International Nuclear Information System (INIS)

Moeller, T.B.; Reif, E.

1998-01-01

This book gives answers to questions frequently heard especially from trainees and doctors not specialising in the field of radiology: Is that a normal finding? How do I decide? What are the objective criteria? The information presented is three-fold. The normal findings of the usual CT and MRI examinations are shown with high-quality pictures serving as a reference, with inscribed important additional information on measures, angles and other criteria describing the normal conditions. These criteria are further explained and evaluated in accompanying texts which also teach the systematic approach for individual picture analysis, and include a check list of major aspects, as a didactic guide for learning. The book is primarily intended for students, radiographers, radiology trainees and doctors from other medical fields, but radiology specialists will also find useful details of help in special cases. (orig./CB) [de

Multivariate statistical modelling based on generalized linear models

CERN Document Server

Fahrmeir, Ludwig

1994-01-01

This book is concerned with the use of generalized linear models for univariate and multivariate regression analysis. Its emphasis is to provide a detailed introductory survey of the subject based on the analysis of real data drawn from a variety of subjects including the biological sciences, economics, and the social sciences. Where possible, technical details and proofs are deferred to an appendix in order to provide an accessible account for non-experts. Topics covered include: models for multi-categorical responses, model checking, time series and longitudinal data, random effects models, and state-space models. Throughout, the authors have taken great pains to discuss the underlying theoretical ideas in ways that relate well to the data at hand. As a result, numerous researchers whose work relies on the use of these models will find this an invaluable account to have on their desks. "The basic aim of the authors is to bring together and review a large part of recent advances in statistical modelling of m...

Expansion Hamiltonian model for a diatomic molecule adsorbed on a surface: Vibrational states of the CO/Cu(100) system including surface vibrations

Energy Technology Data Exchange (ETDEWEB)

Meng, Qingyong, E-mail: mengqingyong@dicp.ac.cn [State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, 116023 Dalian (China); Meyer, Hans-Dieter, E-mail: hans-dieter.meyer@pci.uni-heidelberg.de [Theoretische Chemie, Physikalisch-Chemisches Institut, Ruprecht-Karls Universität Heidelberg, Im Neuenheimer Feld 229, D-69120 Heidelberg (Germany)

2015-10-28

Molecular-surface studies are often done by assuming a corrugated, static (i.e., rigid) surface. To be able to investigate the effects that vibrations of surface atoms may have on spectra and cross sections, an expansion Hamiltonian model is proposed on the basis of the recently reported [R. Marquardt et al., J. Chem. Phys. 132, 074108 (2010)] SAP potential energy surface (PES), which was built for the CO/Cu(100) system with a rigid surface. In contrast to other molecule-surface coupling models, such as the modified surface oscillator model, the coupling between the adsorbed molecule and the surface atoms is already included in the present expansion SAP-PES model, in which a Taylor expansion around the equilibrium positions of the surface atoms is performed. To test the quality of the Taylor expansion, a direct model, that is avoiding the expansion, is also studied. The latter, however, requests that there is only one movable surface atom included. On the basis of the present expansion and direct models, the effects of a moving top copper atom (the one to which CO is bound) on the energy levels of a bound CO/Cu(100) system are studied. For this purpose, the multiconfiguration time-dependent Hartree calculations are carried out to obtain the vibrational fundamentals and overtones of the CO/Cu(100) system including a movable top copper atom. In order to interpret the results, a simple model consisting of two coupled harmonic oscillators is introduced. From these calculations, the vibrational levels of the CO/Cu(100) system as function of the frequency of the top copper atom are discussed.

77 FR 38632 - Findings of Research Misconduct

Science.gov (United States)

2012-06-28

... Institute on Drug Abuse (NIDA), NIH. ORI found that the Respondent engaged in research misconduct by... animal model of Parkinson's disease, 2006 (``manuscript''). Specifically, ORI finds that the Respondent...

Report on activities and findings under DOE grant “Collaborative research. An Interactive Multi-Model for Consensus on Climate Change”

Energy Technology Data Exchange (ETDEWEB)

Duane, Gregory S. [Univ. of Colorado, Boulder, CO (United States); Tsonis, Anastasios [Univ. of Wisconsin, Madison, WI (United States); Kocarev, Ljupco [Univ. of California, San Diego, CA (United States); Tribbia, Joseph [National Center for Atmospheric Research, Boulder, CO (United States)

2015-10-30

The project takes a hierarchical approach. The supermodeling scheme was first studied exhaustively with simple systems of ordinary differential equations. Results were described in detail in the previous report. The principal findings were that 1) for highly non-linear systems, such as Lorenz-63, including systems which describe phenomena on very different (atmosphere/ocean) times scales, supermodeling is far superior to any form of output-averaging; 2) negative coefficients can be used to advantage in situations where all models err in the same way, but to different degrees; 3) an interesting variant of supermodeling, “weighted supermodeling”, is the limiting case where inter-model nudging coefficients in the originally conceived “connected supermodel” become infinite, but with fixed ratios, corresponding to a direct combination of the tendencies that appear in corresponding equations for the alternative models; 4) noise is useful for avoiding local optima in training the inter-model coefficients in the supermodel. The supermodeling scheme was then investigated with simple quasigeostrophic (QG) models. As described in the previous report, it was found that QG models on a sphere can be coupled most efficaciously by working in a basis which captures the most variance, rather than the most instability, a somewhat unexpected result that still deserves scrutiny in a broader context. Further studies (since the last report) with QG channel models addressed the central question of when supermodeling is superior to output averaging in situations where nonlinearites are less extreme than with the ODEs initially studied. It was found that for realistic variations in a parameter in the QG model, output averaging is sufficient to capture all but the most subtle quantitative and qualitative behavior. Supermodeling helps when qualitative differences between the models result from unrealistically large parameter differences, or when very detailed spatial structure of the

Associations between spondyloarthritis features and magnetic resonance imaging findings

DEFF Research Database (Denmark)

Arnbak, Bodil; Jurik, Anne Grethe; Hørslev-Petersen, Kim

2016-01-01

were 1) to estimate the prevalence of magnetic resonance imaging (MRI) findings and clinical features included in the ASAS criteria for SpA and 2) to explore the associations between MRI findings and clinical features. METHODS: We included patients ages 18-40 years with persistent low back pain who had...... been referred to the Spine Centre of Southern Denmark. We collected information on clinical features (including HLA-B27 and high-sensitivity C-reactive protein) and MRI findings in the spine and sacroiliac (SI) joints. RESULTS: Of 1,020 included patients, 537 (53%) had at least 1 of the clinical...... according to the ASAS definition was present in 217 patients (21%). Of those 217 patients, 91 (42%) had the minimum amount of bone marrow edema required according to the ASAS definition (a low bone marrow edema score). The presence of HLA-B27, peripheral arthritis, a good response to NSAIDs, and preceding...

XFEL OSCILLATOR SIMULATION INCLUDING ANGLE-DEPENDENT CRYSTAL REFLECTIVITY

International Nuclear Information System (INIS)

Fawley, William; Lindberg, Ryan; Kim, K.-J.; Shvyd'ko, Yuri

2010-01-01

The oscillator package within the GINGER FEL simulation code has now been extended to include angle-dependent reflectivity properties of Bragg crystals. Previously, the package was modified to include frequencydependent reflectivity in order to model x-ray FEL oscillators from start-up from shot noise through to saturation. We present a summary of the algorithms used for modeling the crystal reflectivity and radiation propagation outside the undulator, discussing various numerical issues relevant to the domain of high Fresnel number and efficient Hankel transforms. We give some sample XFEL-O simulation results obtained with the angle-dependent reflectivity model, with particular attention directed to the longitudinal and transverse coherence of the radiation output.

MR findings of craniopharyngioma

Energy Technology Data Exchange (ETDEWEB)

Lee, Sung Moon; Woo, Young Hoon; Joo, Yang Goo; Suh, Soo Jhi [College of Medicine, Keimyung University, Daegu (Korea, Republic of)

1992-11-15

Craniopharyngioma is a benign, slow-growing tumor that constitues 3-9% of all intracranial tumors, and arises from epithelial remnants of the Rathke's pouch. We analyzed MR (2.0T) findings of ten cases with surgically proved craniopharyngioma retrospectively. CT was available in five cases, and Gd-DTPA was used in six cases. Characteristic findings of craniopharyngioma in MRI included multilocularity and variable signal intensities within each loculus that were more prominent in T1WI. Detection rate of calcification in MR was 60%. Six cases with Gd-DTPA enhancement revealed irregular or rim-like enhancement. MRI provides useful information regarding the location, extent and biochemical characteristics of the oraniopharyngioma as well as its relationship to the neighboring structures which will be valuable in planning surgical resection.

Typical radiological findings in Mirizzi's syndrome

International Nuclear Information System (INIS)

Strunk, H.; Teifke, A.; Menke, H.

1988-01-01

In extrahepatic cholestasis it is necessary to include Mirizzi's syndrome in the differential diagnostic considerations. Characteristic findings in sonography and computed tomography ae: a stone incorporated in the neck of the gallbladder or cystic duct with an extension of the common hepatic duct above the stone and normal width of the bile duct below the sone; in endoscopic retrograde cholangiography (ERC, direkt cholangiography), a characteristic finding is a smooth-walled, segmental stenosis through external compression or an incorporated stone. (orig.) [de

Weight Gain, Schizophrenia and Antipsychotics: New Findings from Animal Model and Pharmacogenomic Studies

Directory of Open Access Journals (Sweden)

Fabio Panariello

2011-01-01

Full Text Available Excess body weight is one of the most common physical health problems among patients with schizophrenia that increases the risk for many medical problems, including type 2 diabetes mellitus, coronary heart disease, osteoarthritis, and hypertension, and accounts in part for 20% shorter life expectancy than in general population. Among patients with severe mental illness, obesity can be attributed to an unhealthy lifestyle, personal genetic profile, as well as the effects of psychotropic medications, above all antipsychotic drugs. Novel “atypical” antipsychotic drugs represent a substantial improvement on older “typical” drugs. However, clinical experience has shown that some, but not all, of these drugs can induce substantial weight gain. Animal models of antipsychotic-related weight gain and animal transgenic models of knockout or overexpressed genes of antipsychotic receptors have been largely evaluated by scientific community for changes in obesity-related gene expression or phenotypes. Moreover, pharmacogenomic approaches have allowed to detect more than 300 possible candidate genes for antipsychotics-induced body weight gain. In this paper, we summarize current thinking on: (1 the role of polymorphisms in several candidate genes, (2 the possible roles of various neurotransmitters and neuropeptides in this adverse drug reaction, and (3 the state of development of animal models in this matter. We also outline major areas for future research.

Spectral element modelling of seismic wave propagation in visco-elastoplastic media including excess-pore pressure development

Science.gov (United States)

Oral, Elif; Gélis, Céline; Bonilla, Luis Fabián; Delavaud, Elise

2017-12-01

Numerical modelling of seismic wave propagation, considering soil nonlinearity, has become a major topic in seismic hazard studies when strong shaking is involved under particular soil conditions. Indeed, when strong ground motion propagates in saturated soils, pore pressure is another important parameter to take into account when successive phases of contractive and dilatant soil behaviour are expected. Here, we model 1-D seismic wave propagation in linear and nonlinear media using the spectral element numerical method. The study uses a three-component (3C) nonlinear rheology and includes pore-pressure excess. The 1-D-3C model is used to study the 1987 Superstition Hills earthquake (ML 6.6), which was recorded at the Wildlife Refuge Liquefaction Array, USA. The data of this event present strong soil nonlinearity involving pore-pressure effects. The ground motion is numerically modelled for different assumptions on soil rheology and input motion (1C versus 3C), using the recorded borehole signals as input motion. The computed acceleration-time histories show low-frequency amplification and strong high-frequency damping due to the development of pore pressure in one of the soil layers. Furthermore, the soil is found to be more nonlinear and more dilatant under triaxial loading compared to the classical 1C analysis, and significant differences in surface displacements are observed between the 1C and 3C approaches. This study contributes to identify and understand the dominant phenomena occurring in superficial layers, depending on local soil properties and input motions, conditions relevant for site-specific studies.

Effects of achievement differences for internal/external frame of reference model investigations: A test of robustness of findings over diverse student samples.

Science.gov (United States)

Schmidt, Isabelle; Brunner, Martin; Preckel, Franzis

2017-11-12

Achievement in math and achievement in verbal school subjects are more strongly correlated than the respective academic self-concepts. The internal/external frame of reference model (I/E model; Marsh, 1986, Am. Educ. Res. J., 23, 129) explains this finding by social and dimensional comparison processes. We investigated a key assumption of the model that dimensional comparisons mainly depend on the difference in achievement between subjects. We compared correlations between subject-specific self-concepts of groups of elementary and secondary school students with or without achievement differences in the respective subjects. The main goals were (1) to show that effects of dimensional comparisons depend to a large degree on the existence of achievement differences between subjects, (2) to demonstrate the generalizability of findings over different grade levels and self-concept scales, and (3) to test a rarely used correlation comparison approach (CCA) for the investigation of I/E model assumptions. We analysed eight German elementary and secondary school student samples (grades 3-8) from three independent studies (Ns 326-878). Correlations between math and German self-concepts of students with identical grades in the respective subjects were compared with the correlation of self-concepts of students having different grades using Fisher's Z test for independent samples. In all samples, correlations between math self-concept and German self-concept were higher for students having identical grades than for students having different grades. Differences in median correlations had small effect sizes for elementary school students and moderate effect sizes for secondary school students. Findings generalized over grades and indicated a developmental aspect in self-concept formation. The CCA complements investigations within I/E-research. © 2017 The British Psychological Society.

Parton recombination model including resonance production. RL-78-040

International Nuclear Information System (INIS)

Roberts, R.G.; Hwa, R.C.; Matsuda, S.

1978-05-01

Possible effects of resonance production on the meson inclusive distribution in the fragmentation region are investigated in the framework of the parton recombination model. From a detailed study of the data on vector-meson production, a reliable ratio of the vector-to-pseudoscalar rates is determined. Then the influence of the decay of the vector mesons on the pseudoscalar spectrum is examined, and the effect found to be no more than 25% for x > 0.5. The normalization of the non-strange antiquark distributions are still higher than those in a quiescent proton. The agreement between the calculated results and data remain very good. 36 references

Parton recombination model including resonance production. RL-78-040

Energy Technology Data Exchange (ETDEWEB)

Roberts, R. G.; Hwa, R. C.; Matsuda, S.

1978-05-01

Possible effects of resonance production on the meson inclusive distribution in the fragmentation region are investigated in the framework of the parton recombination model. From a detailed study of the data on vector-meson production, a reliable ratio of the vector-to-pseudoscalar rates is determined. Then the influence of the decay of the vector mesons on the pseudoscalar spectrum is examined, and the effect found to be no more than 25% for x > 0.5. The normalization of the non-strange antiquark distributions are still higher than those in a quiescent proton. The agreement between the calculated results and data remain very good. 36 references.

A statistical model for estimation of fish density including correlation in size, space, time and between species from research survey data.

Directory of Open Access Journals (Sweden)

J Rasmus Nielsen

Full Text Available Trawl survey data with high spatial and seasonal coverage were analysed using a variant of the Log Gaussian Cox Process (LGCP statistical model to estimate unbiased relative fish densities. The model estimates correlations between observations according to time, space, and fish size and includes zero observations and over-dispersion. The model utilises the fact the correlation between numbers of fish caught increases when the distance in space and time between the fish decreases, and the correlation between size groups in a haul increases when the difference in size decreases. Here the model is extended in two ways. Instead of assuming a natural scale size correlation, the model is further developed to allow for a transformed length scale. Furthermore, in the present application, the spatial- and size-dependent correlation between species was included. For cod (Gadus morhua and whiting (Merlangius merlangus, a common structured size correlation was fitted, and a separable structure between the time and space-size correlation was found for each species, whereas more complex structures were required to describe the correlation between species (and space-size. The within-species time correlation is strong, whereas the correlations between the species are weaker over time but strong within the year.

A new method for finding vacua in string phenomenology

Energy Technology Data Exchange (ETDEWEB)

Gray, James [Institut d' Astrophysique de Paris and APC, Universite de Paris 7, 98 bis, Bd. Arago 75014, Paris (France); He, Yang-Hui [Rudolf Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP (United Kingdom)]|[Merton College, Oxford, OX1 4JD and Mathematical Institute, Oxford University, Oxford (United Kingdom); Ilderton, Anton [School of Mathematics and Statistics, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom); Lukas, Andre [Rudolf Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP (United Kingdom)

2007-05-15

One of the central problems of string-phenomenology is to find stable vacua in the four dimensional effective theories which result from compactification. We present an algorithmic method to find all of the vacua of any given string-phenomenological system in a huge class. In particular, this paper reviews and then extends hep-th/0606122 to include various nonperturbative effects. These include gaugino condensation and instantonic contributions to the superpotential. (authors)

Model Selection and Evaluation Based on Emerging Infectious Disease Data Sets including A/H1N1 and Ebola

Directory of Open Access Journals (Sweden)

Wendi Liu

2015-01-01

Full Text Available The aim of the present study is to apply simple ODE models in the area of modeling the spread of emerging infectious diseases and show the importance of model selection in estimating parameters, the basic reproduction number, turning point, and final size. To quantify the plausibility of each model, given the data and the set of four models including Logistic, Gompertz, Rosenzweg, and Richards models, the Bayes factors are calculated and the precise estimates of the best fitted model parameters and key epidemic characteristics have been obtained. In particular, for Ebola the basic reproduction numbers are 1.3522 (95% CI (1.3506, 1.3537, 1.2101 (95% CI (1.2084, 1.2119, 3.0234 (95% CI (2.6063, 3.4881, and 1.9018 (95% CI (1.8565, 1.9478, the turning points are November 7,November 17, October 2, and November 3, 2014, and the final sizes until December 2015 are 25794 (95% CI (25630, 25958, 3916 (95% CI (3865, 3967, 9886 (95% CI (9740, 10031, and 12633 (95% CI (12515, 12750 for West Africa, Guinea, Liberia, and Sierra Leone, respectively. The main results confirm that model selection is crucial in evaluating and predicting the important quantities describing the emerging infectious diseases, and arbitrarily picking a model without any consideration of alternatives is problematic.

Sodium phenylbutyrate in Huntington's disease: a dose-finding study.

Science.gov (United States)

Hogarth, Penelope; Lovrecic, Luca; Krainc, Dimitri

2007-10-15

Transcriptional dysregulation in Huntington's disease (HD) is mediated in part by aberrant patterns of histone acetylation. We performed a dose-finding study in human HD of sodium phenylbutyrate (SPB), a histone deacetylase inhibitor that ameliorates the HD phenotype in animal models. We used a dose-escalation/de-escalation design, using prespecified toxicity criteria and standard clinical and laboratory safety measures. The maximum tolerated dose was 15 g/day. At higher doses, toxicity included vomiting, lightheadedness, confusion, and gait instability. We saw no significant laboratory or electrocardiographic abnormalities. Gene expression changes in blood suggested an inverse dose-response. In conclusion, SPB at 12 to 15 g/day appears to be safe and well-tolerated in human HD. 2007 Movement Disorder Society

Kinetic model of water disinfection using peracetic acid including synergistic effects.

Science.gov (United States)

Flores, Marina J; Brandi, Rodolfo J; Cassano, Alberto E; Labas, Marisol D

2016-01-01

The disinfection efficiencies of a commercial mixture of peracetic acid against Escherichia coli were studied in laboratory scale experiments. The joint and separate action of two disinfectant agents, hydrogen peroxide and peracetic acid, were evaluated in order to observe synergistic effects. A kinetic model for each component of the mixture and for the commercial mixture was proposed. Through simple mathematical equations, the model describes different stages of attack by disinfectants during the inactivation process. Based on the experiments and the kinetic parameters obtained, it could be established that the efficiency of hydrogen peroxide was much lower than that of peracetic acid alone. However, the contribution of hydrogen peroxide was very important in the commercial mixture. It should be noted that this improvement occurred only after peracetic acid had initiated the attack on the cell. This synergistic effect was successfully explained by the proposed scheme and was verified by experimental results. Besides providing a clearer mechanistic understanding of water disinfection, such models may improve our ability to design reactors.

FINDING CUBOID-BASED BUILDING MODELS IN POINT CLOUDS

Directory of Open Access Journals (Sweden)

W. Nguatem

2012-07-01

Full Text Available In this paper, we present an automatic approach for the derivation of 3D building models of level-of-detail 1 (LOD 1 from point clouds obtained from (dense image matching or, for comparison only, from LIDAR. Our approach makes use of the predominance of vertical structures and orthogonal intersections in architectural scenes. After robustly determining the scene's vertical direction based on the 3D points we use it as constraint for a RANSAC-based search for vertical planes in the point cloud. The planes are further analyzed to segment reliable outlines for rectangular surface within these planes, which are connected to construct cuboid-based building models. We demonstrate that our approach is robust and effective over a range of real-world input data sets with varying point density, amount of noise, and outliers.

ETM documentation update – including modelling conventions and manual for software tools

DEFF Research Database (Denmark)

Grohnheit, Poul Erik

This is the final report for the DTU contribution to Socio Economic Research on Fusion (SERF), EFDA Technology Work programme 2013. The structure and contents of this report was presented at the EFDA-TIMES workshop in Garching 12-13 December 2013. This report gives further background and references......, it summarises the work done during 2013, and it also contains presentations for promotion of fusion as a future element in the electricity generation mix and presentations for the modelling community concerning model development and model documentation – in particular for TIAM collaboration workshops....

Finding the top influential bloggers based on productivity and popularity features

Science.gov (United States)

Khan, Hikmat Ullah; Daud, Ali

2017-07-01

A blog acts as a platform of virtual communication to share comments or views about products, events and social issues. Like other social web activities, blogging actions spread to a large number of people. Users influence others in many ways, such as buying a product, having a particular political or social opinion or initiating new activity. Finding the top influential bloggers is an active research domain as it helps us in various fields, such as online marketing, e-commerce, product search and e-advertisements. There exist various models to find the influential bloggers, but they consider limited features using non-modular approach. This paper proposes a new model, Popularity and Productivity Model (PPM), based on a modular approach to find the top influential bloggers. It consists of popularity and productivity modules which exploit various features. We discuss the role of each proposed and existing features and evaluate the proposed model against the standard baseline models using datasets from the real-world blogs. The analysis using standard performance evaluation measures verifies that both productivity and popularity modules play a vital role to find influential bloggers in blogging community in an effective manner.

Modeling Longitudinal Changes in Older Adults’ Memory for Spoken Discourse: Findings from the ACTIVE Cohort

Science.gov (United States)

Payne, Brennan R.; Gross, Alden L.; Parisi, Jeanine M.; Sisco, Shannon M.; Stine-Morrow, Elizabeth A. L.; Marsiske, Michael; Rebok, George W.

2014-01-01

Episodic memory shows substantial declines with advancing age, but research on longitudinal trajectories of spoken discourse memory (SDM) in older adulthood is limited. Using parallel process latent growth curve models, we examined 10 years of longitudinal data from the no-contact control group (N = 698) of the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) randomized controlled trial in order to test (a) the degree to which SDM declines with advancing age, (b) predictors of these age-related declines, and (c) the within-person relationship between longitudinal changes in SDM and longitudinal changes in fluid reasoning and verbal ability over 10 years, independent of age. Individuals who were younger, White, had more years of formal education, were male, and had better global cognitive function and episodic memory performance at baseline demonstrated greater levels of SDM on average. However, only age at baseline uniquely predicted longitudinal changes in SDM, such that declines accelerated with greater age. Independent of age, within-person decline in reasoning ability over the 10-year study period was substantially correlated with decline in SDM (r = .87). An analogous association with SDM did not hold for verbal ability. The findings suggest that longitudinal declines in fluid cognition are associated with reduced spoken language comprehension. Unlike findings from memory for written prose, preserved verbal ability may not protect against developmental declines in memory for speech. PMID:24304364

Constraining cosmological parameters with observational data including weak lensing effects

Energy Technology Data Exchange (ETDEWEB)

Li Hong [Institute of High Energy Physics, Chinese Academy of Science, PO Box 918-4, Beijing 100049 (China); Theoretical Physics Center for Science Facilities (TPCSF), Chinese Academy of Science (China)], E-mail: hongli@mail.ihep.ac.cn; Liu Jie [Institute of High Energy Physics, Chinese Academy of Science, PO Box 918-4, Beijing 100049 (China); Xia Junqing [Scuola Internazionale Superiore di Studi Avanzati, Via Beirut 2-4, I-34014 Trieste (Italy); Sun Lei; Fan Zuhui [Department of Astronomy, School of Physics, Peking University, Beijing 100871 (China); Tao Charling; Tilquin, Andre [Centre de Physique des Particules de Marseille, CNRS/IN2P3-Luminy and Universite de la Mediterranee, Case 907, F-13288 Marseille Cedex 9 (France); Zhang Xinmin [Institute of High Energy Physics, Chinese Academy of Science, PO Box 918-4, Beijing 100049 (China); Theoretical Physics Center for Science Facilities (TPCSF), Chinese Academy of Science (China)

2009-05-11

In this Letter, we study the cosmological implications of the 100 square degree Weak Lensing survey (the CFHTLS-Wide, RCS, VIRMOS-DESCART and GaBoDS surveys). We combine these weak lensing data with the cosmic microwave background (CMB) measurements from the WMAP5, BOOMERanG, CBI, VSA, ACBAR, the SDSS LRG matter power spectrum and the Type Ia Supernoave (SNIa) data with the 'Union' compilation (307 sample), using the Markov Chain Monte Carlo method to determine the cosmological parameters, such as the equation-of-state (EoS) of dark energy w, the density fluctuation amplitude {sigma}{sub 8}, the total neutrino mass {sigma}m{sub {nu}} and the parameters associated with the power spectrum of the primordial fluctuations. Our results show that the {lambda}CDM model remains a good fit to all of these data. In a flat universe, we obtain a tight limit on the constant EoS of dark energy, w=-0.97{+-}0.041 (1{sigma}). For the dynamical dark energy model with time evolving EoS parameterized as w{sub de}(a)=w{sub 0}+w{sub a}(1-a), we find that the best-fit values are w{sub 0}=-1.064 and w{sub a}=0.375, implying the mildly preference of Quintom model whose EoS gets across the cosmological constant boundary during evolution. Regarding the total neutrino mass limit, we obtain the upper limit, {sigma}m{sub {nu}}<0.471 eV (95% C.L.) within the framework of the flat {lambda}CDM model. Due to the obvious degeneracies between the neutrino mass and the EoS of dark energy model, this upper limit will be relaxed by a factor of 2 in the framework of dynamical dark energy models. Assuming that the primordial fluctuations are adiabatic with a power law spectrum, within the {lambda}CDM model, we find that the upper limit on the ratio of the tensor to scalar is r<0.35 (95% C.L.) and the inflationary models with the slope n{sub s}{>=}1 are excluded at more than 2{sigma} confidence level. In this Letter we pay particular attention to the contribution from the weak lensing data and

Statistical methodology for discrete fracture model - including fracture size, orientation uncertainty together with intensity uncertainty and variability

Energy Technology Data Exchange (ETDEWEB)

Darcel, C. (Itasca Consultants SAS (France)); Davy, P.; Le Goc, R.; Dreuzy, J.R. de; Bour, O. (Geosciences Rennes, UMR 6118 CNRS, Univ. def Rennes, Rennes (France))

2009-11-15

the lineament scale (k{sub t} = 2) on the other, addresses the issue of the nature of the transition. We develop a new 'mechanistic' model that could help in modeling why and where this transition can occur. The transition between both regimes would occur for a fracture length of 1-10 m and even at a smaller scale for the few outcrops that follow the self-similar density model. A consequence for the disposal issue is that the model that is likely to apply in the 'blind' scale window between 10-100 m is the self-similar model as it is defined for large-scale lineaments. The self-similar model, as it is measured for some outcrops and most lineament maps, is definitely worth being investigated as a reference for scales above 1-10 m. In the rest of the report, we develop a methodology for incorporating uncertainty and variability into the DFN modeling. Fracturing properties arise from complex processes which produce an intrinsic variability; characterizing this variability as an admissible variation of model parameter or as the division of the site into subdomains with distinct DFN models is a critical point of the modeling effort. Moreover, the DFN model encompasses a part of uncertainty, due to data inherent uncertainties and sampling limits. Both effects must be quantified and incorporated into the DFN site model definition process. In that context, all available borehole data including recording of fracture intercept positions, pole orientation and relative uncertainties are used as the basis for the methodological development and further site model assessment. An elementary dataset contains a set of discrete fracture intercepts from which a parent orientation/density distribution can be computed. The elementary bricks of the site, from which these initial parent density distributions are computed, rely on the former Single Hole Interpretation division of the boreholes into sections whose local boundaries are expected to reflect - locally - geology

Vertebral involvement in SAPHO syndrome: MRI findings

Energy Technology Data Exchange (ETDEWEB)

Nachtigal, A.; Cardinal, E.; Bureau, N.J. [Dept. of Radiology, Univ. de Montreal, QC (Canada); Sainte-Marie, L.G. [Dept. of Internal Medicine, Univ. de Montreal, QC (Canada); Milette, F. [Department of Pathology, Univ. de Montreal, QC (Canada)

1999-03-01

We report on the MRI findings in the vertebrae and surrounding soft tissues in two patients with the SAPHO syndrome (Synovitis, Acne, Pustulosis, Hyperostosis, Osteitis). The MRI findings include abnormal bone marrow signal, either focal or diffuse, of the vertebral bodies and posterior elements; hyperintense paravertebral soft tissue swelling and abnormal signal of the intervertebral discs. These changes are consistent with discitis and osteitis. (orig.) With 6 figs., 17 refs.

Radiological findings in NAO syndrome

Energy Technology Data Exchange (ETDEWEB)

Al-Otaibi, Leftan; Hugosson, Claes O. [Department of Radiology, King Faisal Specialist Hospital and Research Center, Riyadh (Saudi Arabia); Al-Mayouf, Sulalman M.; Majeed, Mahmoud; Al-Eid, Wea' am; Bahabri, Sultan [Department of Paediatrics, King Faisal Specialist Hospital and Research Center, Riyadh (Saudi Arabia)

2002-07-01

Background: Diseases exhibiting osteolysis in children are rare hereditary conditions. Several types have been recognised with different clinical manifestations. One type includes subcutaneous nodules, arthropathy and osteolysis and has been termed NAO syndrome. Previous radiological reports have described the affected bones, usually the carpal and tarsal regions, but a detailed analysis of the radiological findings of both the axial as well as the appendicular skeleton has not been reported. Objectives: To describe the radiological findings in a large group of children with an autosomal recessive disease characterized by nodules, familial arthropathy and osteolysis. Materials and methods: The study comprises 14 patients from 9 families and all patients had the triad of nodulosis, arthropathy and osteolysis (NAO). Results: The most common radiological manifestations were osteopenia, undertubulation of long bones, arthritic changes, sclerotic sutures of the calvaria, osteolysis and muscle contractures. Other common findings were squared vertebrae, broad medial clavicles and brachycephaly. Progress of disease was documented in more than half of the patients. Conclusions: Our study is the first report of the detailed radiological findings of NAO syndrome. In NAO syndrome, both the axial and appendicular skeleton are involved (orig.)

Radiological findings in NAO syndrome

International Nuclear Information System (INIS)

Al-Otaibi, Leftan; Hugosson, Claes O.; Al-Mayouf, Sulalman M.; Majeed, Mahmoud; Al-Eid, Wea'am; Bahabri, Sultan

2002-01-01

Background: Diseases exhibiting osteolysis in children are rare hereditary conditions. Several types have been recognised with different clinical manifestations. One type includes subcutaneous nodules, arthropathy and osteolysis and has been termed NAO syndrome. Previous radiological reports have described the affected bones, usually the carpal and tarsal regions, but a detailed analysis of the radiological findings of both the axial as well as the appendicular skeleton has not been reported. Objectives: To describe the radiological findings in a large group of children with an autosomal recessive disease characterized by nodules, familial arthropathy and osteolysis. Materials and methods: The study comprises 14 patients from 9 families and all patients had the triad of nodulosis, arthropathy and osteolysis (NAO). Results: The most common radiological manifestations were osteopenia, undertubulation of long bones, arthritic changes, sclerotic sutures of the calvaria, osteolysis and muscle contractures. Other common findings were squared vertebrae, broad medial clavicles and brachycephaly. Progress of disease was documented in more than half of the patients. Conclusions: Our study is the first report of the detailed radiological findings of NAO syndrome. In NAO syndrome, both the axial and appendicular skeleton are involved (orig.)

Dermoscopic findings in cicatricial alopecia

Directory of Open Access Journals (Sweden)

Seher Arı

2013-12-01

Full Text Available Background: Dermoscopy is an important tool for the diagnosis of pigmented skin lesions. Newly, this method has also been used in the diagnosis and follow-up hair and scalp disorders. Objective: The objective of this study was to investigate dermoscopic findings in a sample of patients with clinical and histopathological compatible with cicatricial alopecia. Methods: Twenty nine patients with cicatricial alopecia diagnosed by clinical and histological findings were examined by dermoscopy.. Results: Dermoscopic features evaluated included folliculitis decalvans (n=8, pseudopelade of Brocq (n=7, lichen planopilaris (n=6, discoid lupus erythematosus (n=2, dissecting cellulitis (n=1, and secondary cicatricial alopecia (n=5. Visualization of structures previously examined with naked eye were seen in great detail with dermoscopy. The loss of follicular orifices was seen in all patients with cicatricial alopecia. Perifollicular scaling, arborizing red lines, honeycomb pigment pattern, white dots and tufted hairs were the other most obvious findings. Conclusion: Use of dermoscopy in the clinical evaluation of cicatrical alopecia improves diagnostic capability beyond simple clinic inspection, but larger studies correlating dermoscopic findings with histopathology exams are needed to improve understanding of this method.

Preliminary Findings of the South Africa Power System Capacity Expansion and Operational Modelling Study: Preprint

Energy Technology Data Exchange (ETDEWEB)

Reber, Timothy J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Chartan, Erol Kevin [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Brinkman, Gregory L [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2018-01-01

Wind and solar power contract prices have recently become cheaper than many conventional new-build alternatives in South Africa and trends suggest a continued increase in the share of variable renewable energy (vRE) on South Africa's power system with coal technology seeing the greatest reduction in capacity, see 'Figure 6: Percentage share by Installed Capacity (MW)' in [1]. Hence it is essential to perform a state-of-the-art grid integration study examining the effects of these high penetrations of vRE on South Africa's power system. Under the 21st Century Power Partnership (21CPP), funded by the U.S. Department of Energy, the National Renewable Energy Laboratory (NREL) has significantly augmented existing models of the South African power system to investigate future vRE scenarios. NREL, in collaboration with Eskom's Planning Department, further developed, tested and ran a combined capacity expansion and operational model of the South African power system including spatially disaggregated detail and geographical representation of system resources. New software to visualize and interpret modelling outputs has been developed, and scenario analysis of stepwise vRE build targets reveals new insight into associated planning and operational impacts and costs. The model, built using PLEXOS, is split into two components, firstly a capacity expansion model and secondly a unit commitment and economic dispatch model. The capacity expansion model optimizes new generation decisions to achieve the lowest cost, with a full understanding of capital cost and an approximated understanding of operational costs. The operational model has a greater set of detailed operational constraints and is run at daily resolutions. Both are run from 2017 through 2050. This investigation suggests that running both models in tandem may be the most effective means to plan the least cost South African power system as build plans seen to be more expensive than optimal by the

Comparison of logistic regression and neural models in predicting the outcome of biopsy in breast cancer from MRI findings

International Nuclear Information System (INIS)

Abdolmaleki, P.; Yarmohammadi, M.; Gity, M.

2004-01-01

Background: We designed an algorithmic model based on regression analysis and a non-algorithmic model based on the Artificial Neural Network. Materials and methods: The ability of these models was compared together in clinical application to differentiate malignant from benign breast tumors in a study group of 161 patient's records. Each patient's record consisted of 6 subjective features extracted from MRI appearance. These findings were enclosed as features extracted for an Artificial Neural Network as well as a logistic regression model to predict biopsy outcome. After both models had been trained perfectly on samples (n=100), the validation samples (n=61) were presented to the trained network as well as the established logistic regression models. Finally, the diagnostic performance of models were compared to the that of the radiologist in terms of sensitivity, specificity and accuracy, using receiver operating characteristic curve analysis. Results: The average out put of the Artificial Neural Network yielded a perfect sensitivity (98%) and high accuracy (90%) similar to that one of an expert radiologist (96% and 92%) while specificity was smaller than that (67%) verses 80%). The output of the logistic regression model using significant features showed improvement in specificity from 60% for the logistic regression model using all features to 93% for the reduced logistic regression model, keeping the accuracy around 90%. Conclusion: Results show that Artificial Neural Network and logistic regression model prove the relationship between extracted morphological features and biopsy results. Using statistically significant variables reduced logistic regression model outperformed of Artificial Neural Network with remarkable specificity while keeping high sensitivity is achieved

NASTRAN thermal analyzer: Theory and application including a guide to modeling engineering problems, volume 2. [sample problem library guide

Science.gov (United States)

Jackson, C. E., Jr.

1977-01-01

A sample problem library containing 20 problems covering most facets of Nastran Thermal Analyzer modeling is presented. Areas discussed include radiative interchange, arbitrary nonlinear loads, transient temperature and steady-state structural plots, temperature-dependent conductivities, simulated multi-layer insulation, and constraint techniques. The use of the major control options and important DMAP alters is demonstrated.

Optimal path-finding through mental exploration based on neural energy field gradients.

Science.gov (United States)

Wang, Yihong; Wang, Rubin; Zhu, Yating

2017-02-01

Rodent animal can accomplish self-locating and path-finding task by forming a cognitive map in the hippocampus representing the environment. In the classical model of the cognitive map, the system (artificial animal) needs large amounts of physical exploration to study spatial environment to solve path-finding problems, which costs too much time and energy. Although Hopfield's mental exploration model makes up for the deficiency mentioned above, the path is still not efficient enough. Moreover, his model mainly focused on the artificial neural network, and clear physiological meanings has not been addressed. In this work, based on the concept of mental exploration, neural energy coding theory has been applied to the novel calculation model to solve the path-finding problem. Energy field is constructed on the basis of the firing power of place cell clusters, and the energy field gradient can be used in mental exploration to solve path-finding problems. The study shows that the new mental exploration model can efficiently find the optimal path, and present the learning process with biophysical meaning as well. We also analyzed the parameters of the model which affect the path efficiency. This new idea verifies the importance of place cell and synapse in spatial memory and proves that energy coding is effective to study cognitive activities. This may provide the theoretical basis for the neural dynamics mechanism of spatial memory.

Imaging findings of xanthogranulomatous pyelonephritis

Energy Technology Data Exchange (ETDEWEB)

Kim, Jong Chul [School of Medicine, Chungnam National University, Taejon (Korea, Republic of)

2000-01-01

To define the imaging patterns of xanthogranulomatous pyelonephritis (XGP). The demographic, clinical, and imaging findings of 21 cases of pathologically proven XGP in 20 patients (bilateral in one) were evaluated. The findings of ultrasonography and CT were retrospectively evaluated with regard to distribution and extent of the disease, kidney size, the presence of calculi, hydronephrosis, and renal function. The findings were assessed by two radiologists, who established a consensus. Imaging and pathologic findings were compared. Sixteen of the 20 patients were female, and 19 were adults. Their age ranged from 3 to 16 (mean, 45) years. In all patients except one, the disease was unilateral (right: left =3D 13 :16). In one patient, XGP was bilateral, and there were thus 21 cases. Seventeen (81%) of these were diffuse, and four (19%) were focal; extrarenal extension occurred in 13 cases (62%), among which ipsilateral pleural effusion was noted in two. The kidney was enlarged diffusely in 12 cases (57%), and focally in three (14%); urinary calculi were present in 16 cases (76%), with staghorn calculi in four of these; and hydronephrosis occurred in 17 (81%). Impairment of ipsilateral renal function was noted in 13 cases (62%). Clinical findings of inflammation such as fever, pyuria, bacteriuria, or leucocytosis were noted in all patients. In addition to nephromegaly, renal function impairment, and urinary obstruction due to calculi, which are typical features of XGP, the condition may also show variable imaging findings. If the images obtained in the case of a middle-aged woman with clinical findings of urinary infection are atypical, we believe that XGP should be included in the differential diagnosis. (author)

Epstein-Barr virus encephalitis and encephalomyelitis: MR findings

International Nuclear Information System (INIS)

Shian, W.J.; Chi, C.S.

1996-01-01

The purpose of this project is to investigate the clinical and brain MR characteristics of Epstein-Barr virus (EBV) encephalitis and encephalomyelitis. Clinical and 30 MR findings of 29 patients with EBV encephalitis or encephalomyelitis were retrospectively reviewed. Patients included 24 with encephalitis, 3 with encephalomyelitis, and 2 with brain-stem encephalitis. Altered consciousness, seizures, visual hallucination, and acute psychotic reaction were the common presentations. Eight patients had positive MR findings. These included T2 prolongation over gray and white matter, periventricular leukomalacia, and brain atrophy. Transient T2 prolongation over gray and white matter was found in one patient. Our results indicate that EBV encephalitis and encephalomyelitis have a wide range of both clinical and MR findings. The MR lesions may disappear in a short period, so the timing for the MR scan may be critical. (orig.). With 5 figs., 2 tabs

Epstein-Barr virus encephalitis and encephalomyelitis: MR findings

Energy Technology Data Exchange (ETDEWEB)

Shian, W.J. [Department of Pediatrics, Tao-Yuan Veterans Hospital, No. 100, Sec 3, Cheng-Kung Rd, City of Tao-Yuan, Taiwan (Taiwan, Province of China); Chi, C.S. [Department of Pediatrics, Taichung Veterans General Hospital, Taichung, Taiwan (Taiwan, Province of China)

1996-09-01

The purpose of this project is to investigate the clinical and brain MR characteristics of Epstein-Barr virus (EBV) encephalitis and encephalomyelitis. Clinical and 30 MR findings of 29 patients with EBV encephalitis or encephalomyelitis were retrospectively reviewed. Patients included 24 with encephalitis, 3 with encephalomyelitis, and 2 with brain-stem encephalitis. Altered consciousness, seizures, visual hallucination, and acute psychotic reaction were the common presentations. Eight patients had positive MR findings. These included T2 prolongation over gray and white matter, periventricular leukomalacia, and brain atrophy. Transient T2 prolongation over gray and white matter was found in one patient. Our results indicate that EBV encephalitis and encephalomyelitis have a wide range of both clinical and MR findings. The MR lesions may disappear in a short period, so the timing for the MR scan may be critical. (orig.). With 5 figs., 2 tabs.

A Two-Account Life Insurance Model for Scenario-Based Valuation Including Event Risk

Directory of Open Access Journals (Sweden)

Ninna Reitzel Jensen

2015-06-01

Full Text Available Using a two-account model with event risk, we model life insurance contracts taking into account both guaranteed and non-guaranteed payments in participating life insurance as well as in unit-linked insurance. Here, event risk is used as a generic term for life insurance events, such as death, disability, etc. In our treatment of participating life insurance, we have special focus on the bonus schemes “consolidation” and “additional benefits”, and one goal is to formalize how these work and interact. Another goal is to describe similarities and differences between participating life insurance and unit-linked insurance. By use of a two-account model, we are able to illustrate general concepts without making the model too abstract. To allow for complicated financial markets without dramatically increasing the mathematical complexity, we focus on economic scenarios. We illustrate the use of our model by conducting scenario analysis based on Monte Carlo simulation, but the model applies to scenarios in general and to worst-case and best-estimate scenarios in particular. In addition to easy computations, our model offers a common framework for the valuation of life insurance payments across product types. This enables comparison of participating life insurance products and unit-linked insurance products, thus building a bridge between the two different ways of formalizing life insurance products. Finally, our model distinguishes itself from the existing literature by taking into account the Markov model for the state of the policyholder and, hereby, facilitating event risk.

Optimization modeling with spreadsheets

CERN Document Server

Baker, Kenneth R

2015-01-01

An accessible introduction to optimization analysis using spreadsheets Updated and revised, Optimization Modeling with Spreadsheets, Third Edition emphasizes model building skills in optimization analysis. By emphasizing both spreadsheet modeling and optimization tools in the freely available Microsoft® Office Excel® Solver, the book illustrates how to find solutions to real-world optimization problems without needing additional specialized software. The Third Edition includes many practical applications of optimization models as well as a systematic framework that il

Plasma Cell Neoplasms (Including Multiple Myeloma)—Health Professional Version

Science.gov (United States)

There are several types of plasma cell neoplasms, including monoclonal gammopathy of undetermined significance (MGUS), isolated plasmacytoma of the bone, extramedullary plasmacytoma, and multiple myeloma. Find evidence-based information on plasma cell neoplasms treatment, research, and statistics.

Blunt bowel and mesenteric trauma: role of clinical signs along with CT findings in patients' management.

Science.gov (United States)

Firetto, Maria Cristina; Sala, Francesco; Petrini, Marcello; Lemos, Alessandro A; Canini, Tiberio; Magnone, Stefano; Fornoni, Gianluca; Cortinovis, Ivan; Sironi, Sandro; Biondetti, Pietro R

2018-04-27

Bowel and/or mesentery injuries represent the third most common injury among patients with blunt abdominal trauma. Delayed diagnosis increases morbidity and mortality. The aim of our study was to evaluate the role of clinical signs along with CT findings as predictors of early surgical repair. Between March 2014 and February 2017, charts and CT scans of consecutive patients treated for blunt abdominal trauma in two different trauma centers were reread by two experienced radiologists. We included all adult patients who underwent contrast-enhanced CT of the abdomen and pelvis with CT findings of blunt bowel and/or mesenteric injury (BBMI). We divided CT findings into two groups: the first included three highly specific CT signs and the second included six less specific CT signs indicated as "minor CT findings." The presence of abdominal guarding and/or abdominal pain was considered as "clinical signs." Reference standards included surgically proven BBMI and clinical follow-up. Association was evaluated by the chi-square test. A logistic regression model was used to estimate odds ratio (OR) and confidence intervals (CI). Thirty-four (4.1%) out of 831 patients who sustained blunt abdominal trauma had BBMI at CT. Twenty-one out of thirty-four patients (61.8%) underwent surgical repair; the remaining 13 were treated conservatively. Free fluid had a significant statistical association with surgery (p = 0.0044). The presence of three or more minor CT findings was statistically associated with surgery (OR = 8.1; 95% CI, 1.2-53.7). Abdominal guarding along with bowel wall discontinuity and extraluminal air had the highest positive predictive value (100 and 83.3%, respectively). In patients without solid organ injury (SOI), the presence of free fluid along with abdominal guarding and three or more "minor CT findings" is a significant predictor of early surgical repair. The association of bowel wall discontinuity with extraluminal air warrants exploratory laparotomy.

Including Overweight or Obese Students in Physical Education: A Social Ecological Constraint Model

Science.gov (United States)

Li, Weidong; Rukavina, Paul

2012-01-01

In this review, we propose a social ecological constraint model to study inclusion of overweight or obese students in physical education by integrating key concepts and assumptions from ecological constraint theory in motor development and social ecological models in health promotion and behavior. The social ecological constraint model proposes…

An approach for including the stiffness and damping of elastohydrodynamic point contacts in deep groove ball bearing equilibrium models

Science.gov (United States)

Nonato, Fábio; Cavalca, Katia L.

2014-12-01

This work presents a methodology for including the Elastohydrodynamic (EHD) film effects to a lateral vibration model of a deep groove ball bearing by using a novel approximation for the EHD contacts by a set of equivalent nonlinear spring and viscous damper. The fitting of the equivalent contact model used the results of a transient multi-level finite difference EHD algorithm to adjust the dynamic parameters. The comparison between the approximated model and the finite difference simulated results showed a suitable representation of the stationary and dynamic contact behaviors. The linear damping hypothesis could be shown as a rough representation of the actual hysteretic behavior of the EHD contact. Nevertheless, the overall accuracy of the model was not impaired by the use of such approximation. Further on, the inclusion of the equivalent EHD contact model is equated for both the restoring and the dissipative components of the bearing's lateral dynamics. The derived model was used to investigate the effects of the rolling element bearing lubrication on the vibration response of a rotor's lumped parameter model. The fluid film stiffening effect, previously only observable by experimentation, could be quantified using the proposed model, as well as the portion of the bearing damping provided by the EHD fluid film. Results from a laboratory rotor-bearing test rig were used to indirectly validate the proposed contact approximation. A finite element model of the rotor accounting for the lubricated bearing formulation adequately portrayed the frequency content of the bearing orbits observed on the test rig.

Teacher Perceptions about the Importance of Parental Involvement for Included Students with Learning Disabilities in New York Metropolitan Area Orthodox Yeshivas and Day Schools

Science.gov (United States)

Grossman, Goldie Eichorn

2010-01-01

The population of students attending Jewish day schools includes an increasing number of students with exceptional needs. How Jewish schools meet the needs of these students is an important question. Inclusive education is a service model predicated on legal and philosophical mores as well as pedagogical and psychological findings. The quality of…

A sub-circuit MOSFET model with a wide temperature range including cryogenic temperature

Energy Technology Data Exchange (ETDEWEB)

Jia Kan; Sun Weifeng; Shi Longxing, E-mail: jiakan.01@gmail.com [National ASIC System Engineering Research Center, Southeast University, Nanjing 210096 (China)

2011-06-15

A sub-circuit SPICE model of a MOSFET for low temperature operation is presented. Two resistors are introduced for the freeze-out effect, and the explicit behavioral models are developed for them. The model can be used in a wide temperature range covering both cryogenic temperature and regular temperatures. (semiconductor devices)

CT findings of subdural hematomas: as a special references of atypical CT findings

Energy Technology Data Exchange (ETDEWEB)

Cho, Whi Yul; Chung, Tae Sub; Suh, Jung Ho; Kim, Dong Ik; Kim, Ki Whang; Park, Chang Yun [College of Medicine, Yonsei University, Seoul (Korea, Republic of)

1987-10-15

Subdural hematomas (SDH) are relatively common and the typical CT findings according to the age of them are well established. The CT findings of 82 patients with SDHs were reviewed and compared with the operative findings. The results were as follow: 1. The most common cause of SDHs was the direct trauma which was noted in 60 cases (73.2%). 2. The atypical CT findings of the mixed density were seen in 19 cases (23.2%), including acute SDH 7 cases (20%), subacute SDH 5 cases (41.7%), and chronic SDH 7 cases (20%). 3. The possible causes of the mixed density in acute SDH were unclotted blood in early stage of hematoma development or serum extruded during the early phase of clot retraction. But the possibility of cerebrospinal fluid within subdural space due to an arachnoid tear could not be excluded. 4. The possible causes of the mixed density in subacute and chronic SDH were serum extruded during the hematoma resolution and rebleeding. 5. Wall enhancement of hematomas was noted in 3 cases (25%) of subacute SDHs and 15 cases (42.9%) of chronic SDHs. 6. Most of SDHs was crescentic in shape, but lenticular in 4 cases (4.9%). Midline shift and compression of ventricles were proportional to the maximum thickness of SDHs. There were seen ipsilateral dilatation of ventricles in 9 cases (11.0%) and brain edema in 11 cases (13.4%)

MRI findings in the painful hemiplegic shoulder

International Nuclear Information System (INIS)

Tavora, D.G.F.; Gama, R.L.; Bomfim, R.C.; Nakayama, M.; Silva, C.E.P.

2010-01-01

Aim: To evaluate the magnetic resonance imaging (MRI) findings in painful hemiplegic shoulder (PHS) in hemiplegic post-stroke patients. Materials and methods: Patients with hemiplegia following their first cerebrovascular accident who were admitted to the Sarah Network of Hospitals for Rehabilitation were studied. Forty-five patients with pain in the hemiplegic shoulder and 23 post-stroke patients without shoulder pain were investigated. MRI and radiographic findings of the hemiplegic and contralateral asymptomatic shoulders were evaluated. Results: Some MRI findings were more frequent in PHS group, including synovial capsule thickening, synovial capsule enhancement, and enhancement in the rotator cuff interval. Conclusions: Adhesive capsulitis was found to be a possible cause of PHS.

MRI findings in the painful hemiplegic shoulder

Energy Technology Data Exchange (ETDEWEB)

Tavora, D.G.F., E-mail: danielgurgel@sarah.b [Department of Radiology, Sarah Network of Hospitals for Rehabilitation, Fortaleza (Brazil); Gama, R.L.; Bomfim, R.C. [Department of Radiology, Sarah Network of Hospitals for Rehabilitation, Fortaleza (Brazil); Nakayama, M. [Department of Radiology, Federal University of Grande Dourados, Dourados (Brazil); Silva, C.E.P. [Department of Statistics, Sarah Network of Hospitals for Rehabilitation, Fortaleza (Brazil)

2010-10-15

Aim: To evaluate the magnetic resonance imaging (MRI) findings in painful hemiplegic shoulder (PHS) in hemiplegic post-stroke patients. Materials and methods: Patients with hemiplegia following their first cerebrovascular accident who were admitted to the Sarah Network of Hospitals for Rehabilitation were studied. Forty-five patients with pain in the hemiplegic shoulder and 23 post-stroke patients without shoulder pain were investigated. MRI and radiographic findings of the hemiplegic and contralateral asymptomatic shoulders were evaluated. Results: Some MRI findings were more frequent in PHS group, including synovial capsule thickening, synovial capsule enhancement, and enhancement in the rotator cuff interval. Conclusions: Adhesive capsulitis was found to be a possible cause of PHS.

Regret causes ego-depletion and finding benefits in the regrettable events alleviates ego-depletion.

Science.gov (United States)

Gao, Hongmei; Zhang, Yan; Wang, Fang; Xu, Yan; Hong, Ying-Yi; Jiang, Jiang

2014-01-01

This study tested the hypotheses that experiencing regret would result in ego-depletion, while finding benefits (i.e., "silver linings") in the regret-eliciting events counteracted the ego-depletion effect. Using a modified gambling paradigm (Experiments 1, 2, and 4) and a retrospective method (Experiments 3 and 5), five experiments were conducted to induce regret. Results revealed that experiencing regret undermined performance on subsequent tasks, including a paper-and-pencil calculation task (Experiment 1), a Stroop task (Experiment 2), and a mental arithmetic task (Experiment 3). Furthermore, finding benefits in the regret-eliciting events improved subsequent performance (Experiments 4 and 5), and this improvement was mediated by participants' perceived vitality (Experiment 4). This study extended the depletion model of self-regulation by considering emotions with self-conscious components (in our case, regret). Moreover, it provided a comprehensive understanding of how people felt and performed after experiencing regret and after finding benefits in the events that caused the regret.

Different concepts and models of information for family-relevant genetic findings: comparison and ethical analysis.

Science.gov (United States)

Lenk, Christian; Frommeld, Debora

2015-08-01

Genetic predispositions often concern not only individual persons, but also other family members. Advances in the development of genetic tests lead to a growing number of genetic diagnoses in medical practice and to an increasing importance of genetic counseling. In the present article, a number of ethical foundations and preconditions for this issue are discussed. Four different models for the handling of genetic information are presented and analyzed including a discussion of practical implications. The different models' ranges of content reach from a strictly autonomous position over self-governed arrangements in the practice of genetic counseling up to the involvement of official bodies and committees. The different models show a number of elements which seem to be very useful for the handling of genetic data in families from an ethical perspective. In contrast, the limitations of the standard medical attempt regarding confidentiality and personal autonomy in the context of genetic information in the family are described. Finally, recommendations for further ethical research and the development of genetic counseling in families are given.

Models of disordered media: some new results, including some new connections between composite-media, fluid-state, and random-flight theories

International Nuclear Information System (INIS)

Stell, G.

1983-01-01

Some new theoretical results on the microstructure of models of two-phase disordered media are given, as well as the new quantitative bounds on the thermal conductivity that follows for one such model (randomly centered spherical inclusions). A second set of results is then given for random flights, including random flights with hit expectancy prescribed in a unit hall around the flight origin. Finally, some interesting correspondences are demonstrated, via the Ornstein-Zernike equation, between random-flight results, liquid-state results and percolation-theory results. 27 references, 6 figures, 4 tables

Magnetic resonance imaging findings in anterolateral impingement of the ankle

International Nuclear Information System (INIS)

Jordan, L.K. III.; Cooperman, A.E.; Helms, C.A.; Speer, K.P.

2000-01-01

Objective. To demonstrate the MR imaging findings of anterolateral impingement (ALI) of the ankle.Design and patients. Nine patients with a history of ankle inversion injury and chronic lateral ankle pain were imaged with MR imaging, and the findings correlated with the results of arthroscopy. Three additional patients with clinically suspected ALI of the ankle were also included. Ankle MR imaging studies from 20 control patients in whom ALI was not suspected clinically were examined for similar findings to the patient group.Results. MR imaging findings in the patients with ALI included a soft tissue signal mass in the anterolateral gutter of the ankle in 12 of 12 (100%) cases, corresponding to the synovial hypertrophy and soft tissue mass found at arthroscopy in the nine patients who underwent arthroscopy. Disruption, attenuation, or marked thickening of the anterior talofibular ligament was seen in all cases. Additional findings included signs of synovial hypertrophy elsewhere in the tibiotalar joint in seven of 12 patients (58%) and bony and cartilaginous injuries to the tibiotalar joint in five of 12 (42%). None of the control patients demonstrated MR imaging evidence of a soft tissue mass in the anterolateral gutter.Conclusions. ALI of the ankle is a common cause for chronic lateral ankle pain. It has been well described in the orthopedic literature but its imaging findings have not been clearly elucidated. The MR imaging findings, along with the appropriate clinical history, can be used to direct arthroscopic examination and subsequent debridement. (orig.)

Modelled hydraulic redistribution by sunflower (Helianthus annuus L.) matches observed data only after including night-time transpiration.

Science.gov (United States)

Neumann, Rebecca B; Cardon, Zoe G; Teshera-Levye, Jennifer; Rockwell, Fulton E; Zwieniecki, Maciej A; Holbrook, N Michele

2014-04-01

The movement of water from moist to dry soil layers through the root systems of plants, referred to as hydraulic redistribution (HR), occurs throughout the world and is thought to influence carbon and water budgets and ecosystem functioning. The realized hydrologic, biogeochemical and ecological consequences of HR depend on the amount of redistributed water, whereas the ability to assess these impacts requires models that correctly capture HR magnitude and timing. Using several soil types and two ecotypes of sunflower (Helianthus annuus L.) in split-pot experiments, we examined how well the widely used HR modelling formulation developed by Ryel et al. matched experimental determination of HR across a range of water potential driving gradients. H. annuus carries out extensive night-time transpiration, and although over the last decade it has become more widely recognized that night-time transpiration occurs in multiple species and many ecosystems, the original Ryel et al. formulation does not include the effect of night-time transpiration on HR. We developed and added a representation of night-time transpiration into the formulation, and only then was the model able to capture the dynamics and magnitude of HR we observed as soils dried and night-time stomatal behaviour changed, both influencing HR. © 2013 John Wiley & Sons Ltd.

Sharing Research Findings with Research Participants and Communities

Directory of Open Access Journals (Sweden)

LE Ferris

2011-06-01

Full Text Available In occupational and environmental health research, individual, group and community research participants have a unique and vested interest in the research findings. The ethical principles of autonomy, non-maleficence and beneficence are helpful in considering the ethical issues in the disclosure of research findings in occupational and environmental health research. Researchers need to include stakeholders, such as groups and communities, in these discussions and in planning for the dissemination of research findings. These discussions need to occur early in the research process.

Microfluidic System Simulation Including the Electro-Viscous Effect

Science.gov (United States)

Rojas, Eileen; Chen, C. P.; Majumdar, Alok

2007-01-01

This paper describes a practical approach using a general purpose lumped-parameter computer program, GFSSP (Generalized Fluid System Simulation Program) for calculating flow distribution in a network of micro-channels including electro-viscous effects due to the existence of electrical double layer (EDL). In this study, an empirical formulation for calculating an effective viscosity of ionic solutions based on dimensional analysis is described to account for surface charge and bulk fluid conductivity, which give rise to electro-viscous effect in microfluidics network. Two dimensional slit micro flow data was used to determine the model coefficients. Geometry effect is then included through a Poiseuille number correlation in GFSSP. The bi-power model was used to calculate flow distribution of isotropically etched straight channel and T-junction microflows involving ionic solutions. Performance of the proposed model is assessed against experimental test data.

Statistical methodology for discrete fracture model - including fracture size, orientation uncertainty together with intensity uncertainty and variability

International Nuclear Information System (INIS)

Darcel, C.; Davy, P.; Le Goc, R.; Dreuzy, J.R. de; Bour, O.

2009-11-01

the other, addresses the issue of the nature of the transition. We develop a new 'mechanistic' model that could help in modeling why and where this transition can occur. The transition between both regimes would occur for a fracture length of 1-10 m and even at a smaller scale for the few outcrops that follow the self-similar density model. A consequence for the disposal issue is that the model that is likely to apply in the 'blind' scale window between 10-100 m is the self-similar model as it is defined for large-scale lineaments. The self-similar model, as it is measured for some outcrops and most lineament maps, is definitely worth being investigated as a reference for scales above 1-10 m. In the rest of the report, we develop a methodology for incorporating uncertainty and variability into the DFN modeling. Fracturing properties arise from complex processes which produce an intrinsic variability; characterizing this variability as an admissible variation of model parameter or as the division of the site into subdomains with distinct DFN models is a critical point of the modeling effort. Moreover, the DFN model encompasses a part of uncertainty, due to data inherent uncertainties and sampling limits. Both effects must be quantified and incorporated into the DFN site model definition process. In that context, all available borehole data including recording of fracture intercept positions, pole orientation and relative uncertainties are used as the basis for the methodological development and further site model assessment. An elementary dataset contains a set of discrete fracture intercepts from which a parent orientation/density distribution can be computed. The elementary bricks of the site, from which these initial parent density distributions are computed, rely on the former Single Hole Interpretation division of the boreholes into sections whose local boundaries are expected to reflect - locally - geology and fracturing properties main characteristics. From that

In silico modeling to predict drug-induced phospholipidosis

International Nuclear Information System (INIS)

Choi, Sydney S.; Kim, Jae S.; Valerio, Luis G.; Sadrieh, Nakissa

2013-01-01

Drug-induced phospholipidosis (DIPL) is a preclinical finding during pharmaceutical drug development that has implications on the course of drug development and regulatory safety review. A principal characteristic of drugs inducing DIPL is known to be a cationic amphiphilic structure. This provides evidence for a structure-based explanation and opportunity to analyze properties and structures of drugs with the histopathologic findings for DIPL. In previous work from the FDA, in silico quantitative structure–activity relationship (QSAR) modeling using machine learning approaches has shown promise with a large dataset of drugs but included unconfirmed data as well. In this study, we report the construction and validation of a battery of complementary in silico QSAR models using the FDA's updated database on phospholipidosis, new algorithms and predictive technologies, and in particular, we address high performance with a high-confidence dataset. The results of our modeling for DIPL include rigorous external validation tests showing 80–81% concordance. Furthermore, the predictive performance characteristics include models with high sensitivity and specificity, in most cases above ≥ 80% leading to desired high negative and positive predictivity. These models are intended to be utilized for regulatory toxicology applied science needs in screening new drugs for DIPL. - Highlights: • New in silico models for predicting drug-induced phospholipidosis (DIPL) are described. • The training set data in the models is derived from the FDA's phospholipidosis database. • We find excellent predictivity values of the models based on external validation. • The models can support drug screening and regulatory decision-making on DIPL

Prenatal ultrasonographic findings of cloacal anomaly

Energy Technology Data Exchange (ETDEWEB)

Song, Mi Jin [Samsung Cheil Hospital, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

2002-09-15

To evaluate the ultrasonographic characteristic of a rare malformation comples, Cloacal anomaly on prenatal ultrasonography. From March 1991 to July 2001, eight cases with the persistent cloaca (4 cases in female and 1 case in male) and cloacal exstrophy (3 cases) diagnosed by prenatal ultrasound examination were included, and all of them were pathologically confirmed by autopsy. One radiologist retrospectively analyzed the prenatal sonographic images, including the urinary bladder, kidney, pelvic cyst, abdominal wall defect and amount of amniotic fluid. The ultrasonographic diagnosis was established at 21.8 {+-} 7.8 weeks of gestation. The prenatal ultrasonographic findings of the persistent cloaca were absent bladder (n=2), distended bladder (n=2) and small thick bladder (n=1). Sonography of the kidney showed normal (n=2), hydronephrosis (n=1), dysplasia (n=1) and unilateral hydronephrosis with absent contralateral kidney (n=1). Four fetuses showed septated pelvic cyst; three fetuses, oligohydramnios. The prenatal ultrasonographic findings of cloacal exstrophy included absent bladder (n=3), normal kidney (n=1), hydronephrosis (n=1) and absent kidney (n=1). All fetuses with cloacal exstrophy had abdominal wall defect while two of them had oligohydramnios. A prenatal diagnosis of persistent cloaca can be confidently made when there is septated pelvic cyst combined oligohydramnios, sediments within the cyst and intraluminal calcifications. Cloacal exstrophy should be included in diagnosis if there is a low abdominal wall defect with absent urinary bladder.

CT findings of slilcosis

International Nuclear Information System (INIS)

Jung, Dong Hee; Kim, Kun Il; Son, Hyun Ju; Ro, Young Jin; Jung, Doo Young; Park, Jae Yeong; Lee, Jun Woo; Kim, Byung Soo

1996-01-01

To describe chest radiographic and CT findings of silicosis, and to compare their findings. Ten coal miners and six stonemasons were included in this study. All were male and their mean age was 53.1. The mean duration of dust exposure was 15.2 years(range, 5-30 years) in coal miners and 25.3 years(range, 15-35 years) in stonemasons. Chest radiographs(n=16), conventional CT scans(n=4), and high resolution CT(HRCT) scans(n=13) were evaluated. Parenchymal abnormalities were interpreted on the basis of ILO standard films(1980) in chest radiographs and on the basis of CAP(College of American Pathologists, 1979) in CT(HRCT) films. Chest radiographs revealed large opacities(n=8), small opacities(n=6), and normal findings(n=2). Type r(n=4) and category 1/1(n=2) were most common for small opacities, while for large opacities, category B(n=4) and category c(n=4) were most common. These small and large opacities were located predominantly in the area of the upper and middle lung. Associated findings were emphysema(n=7), eggshell nodal calcifications(n=3), pneumothorax(n=3), C-P angle blunting(n=4), and pleural thickening(n=1). CT scans revealed micronodules(n=16), nodules(n=3), and progressive massive fibrosis(PMF, n=8). All these lesions were located in the upper and middle lungs, especially in the central portion of the posterior lung. PMF showed diffuse and homogenous(n=3) and puntate(n=2) calcifications, cavitations(n=5), air bronchograms(n=3), and necrosis(n=1). Peripheral paracicatrical emphysema was associated with PMF(n=8). Other findings were pneumothorax(n=4), emphysema(n=10), hilar and mediastinal nodal enlargement(n=11) bronchial wall thick- enings(n=6), bronchiectasis(n=1), pleural thickening(n=7), parenchymal fibrosis(n=1), and pulmonary tuberculosis(n=2). Small and large opacities in chest radiographs and micronodules, nodules, and PMFs in CT (HRCT) films were located predominately in the upper and middle lungs, especially in the central portion of the

Classical model for nuclear collisions including the meson degree of freedom

International Nuclear Information System (INIS)

Babinet, R.; Kunz, J.; Mosel, U.; Wilets, L.

1980-01-01

Many different approaches have been taken to describe high energy heavy ion collisions. L. Wilets et al proposed a classical treatment of the problem. In his model non-relativistic nucleons move on classical trajectories. However, the Pauli-principle is simulated by a momentum dependent potential acting between the nucleons. This model is extended in two ways. The nucleons are coupled to a pionfield, which enables us to describe inelastic processes. Nucleons and pionfiled are treated completely relativistically, this also assures Lorentz invariance. We aim at a set of classical equations of motion describing the interacting system of nucleons and pionfield. These classical equations should have a quantum mechanical basis. Further, they should contain such fundamental properties of the pion-nucleon system as the Δ(3,3)-resonance, at least in a qualitative manner. (orig./FKS)

MRI finding of ethylmalonic encephalopathy: case report

International Nuclear Information System (INIS)

Kim, Jin Yong; Lee, Shi Kyung; Han, Chun Hwan; Rho, Eun Jin

2002-01-01

Ethylmalonic encephalopathy is a rare syndrom characterized by developmental delay, acrocyanosis, petechiae, chronic diarrhea, and ethylmalonic, lactic, and methylsuccinic aciduria. We report the MRI finding of ethylmalonic encephalopathy including previously unreported intracranial hematoma

LIDT-DD: A New Self-Consistent Debris Disc Model Including Radiation Pressure and Coupling Dynamical and Collisional Evolution

Science.gov (United States)

Kral, Q.; Thebault, P.; Charnoz, S.

2014-01-01

The first attempt at developing a fully self-consistent code coupling dynamics and collisions to study debris discs (Kral et al. 2013) is presented. So far, these two crucial mechanisms were studied separately, with N-body and statistical collisional codes respectively, because of stringent computational constraints. We present a new model named LIDT-DD which is able to follow over long timescales the coupled evolution of dynamics (including radiation forces) and collisions in a self-consistent way.

Finding a Hadamard matrix by simulated annealing of spin vectors

Science.gov (United States)

Bayu Suksmono, Andriyan

2017-05-01

Reformulation of a combinatorial problem into optimization of a statistical-mechanics system enables finding a better solution using heuristics derived from a physical process, such as by the simulated annealing (SA). In this paper, we present a Hadamard matrix (H-matrix) searching method based on the SA on an Ising model. By equivalence, an H-matrix can be converted into a seminormalized Hadamard (SH) matrix, whose first column is unit vector and the rest ones are vectors with equal number of -1 and +1 called SH-vectors. We define SH spin vectors as representation of the SH vectors, which play a similar role as the spins on Ising model. The topology of the lattice is generalized into a graph, whose edges represent orthogonality relationship among the SH spin vectors. Starting from a randomly generated quasi H-matrix Q, which is a matrix similar to the SH-matrix without imposing orthogonality, we perform the SA. The transitions of Q are conducted by random exchange of {+, -} spin-pair within the SH-spin vectors that follow the Metropolis update rule. Upon transition toward zeroth energy, the Q-matrix is evolved following a Markov chain toward an orthogonal matrix, at which the H-matrix is said to be found. We demonstrate the capability of the proposed method to find some low-order H-matrices, including the ones that cannot trivially be constructed by the Sylvester method.

Radiological findings in the diagnosis of genitourinary candidiasis

Energy Technology Data Exchange (ETDEWEB)

Erden, A. [Dept. of Radiology, Univ. of Ankara (Turkey); Hafta Sokak, Ankara (Turkey); Fitoz, S.; Karaguelle, T.; Tuekel, S.; Akyar, S. [Dept. of Radiology, Univ. of Ankara (Turkey)

2000-12-01

The presence of fungus balls within the collecting system is an important clue to the radiological diagnosis of genitourinary candidiasis. In this report, an 8-month-old infant with this opportunistic infection is described. Emphasis is placed on the radiological findings of renal candidiasis, including previously unreported MR appearances. Sonographic and Doppler findings of accompanying Candida epididymitis are also described. (orig.)

Radiological findings in the diagnosis of genitourinary candidiasis

International Nuclear Information System (INIS)

Erden, A.; Fitoz, S.; Karaguelle, T.; Tuekel, S.; Akyar, S.

2000-01-01

The presence of fungus balls within the collecting system is an important clue to the radiological diagnosis of genitourinary candidiasis. In this report, an 8-month-old infant with this opportunistic infection is described. Emphasis is placed on the radiological findings of renal candidiasis, including previously unreported MR appearances. Sonographic and Doppler findings of accompanying Candida epididymitis are also described. (orig.)

Noninvasive model including right ventricular speckle tracking for the evaluation of pulmonary hypertension.

Science.gov (United States)

Mahran, Yossra; Schueler, Robert; Weber, Marcel; Pizarro, Carmen; Nickenig, Georg; Skowasch, Dirk; Hammerstingl, Christoph

2016-08-26

To find parameters from transthorathic echocardiography (TTE) including speckle-tracking (ST) analysis of the right ventricle (RV) to identify precapillary pulmonary hypertension (PH). Forty-four patients with suspected PH undergoing right heart catheterization (RHC) were consecutively included (mean age 63.1 ± 14 years, 61% male gender). All patients underwent standardized TTE including ST analysis of the RV. Based on the subsequent TTE-derived measurements, the presence of PH was assessed: Left ventricular ejection fraction (LVEF) was calculated by Simpsons rule from 4Ch. Systolic pulmonary artery pressure (sPAP) was assessed with continuous wave Doppler of systolic tricuspid regurgitant velocity and regarded raised with values ≥ 30 mmHg as a surrogate parameter for RA pressure. A concomitantly elevated PCWP was considered a means to discriminate between the precapillary and postcapillary form of PH. PCWP was considered elevated when the E/e' ratio was > 12 as a surrogate for LV diastolic pressure. E/e' ratio was measured by gauging systolic and diastolic velocities of the lateral and septal mitral valve annulus using TDI mode. The results were then averaged with conventional measurement of mitral valve inflow. Furthermore, functional testing with six minutes walking distance (6MWD), ECG-RV stress signs, NT pro-BNP and other laboratory values were assessed. PH was confirmed in 34 patients (precapillary PH, n = 15, postcapillary PH, n = 19). TTE showed significant differences in E/e' ratio (precapillary PH: 12.3 ± 4.4, postcapillary PH: 17.3 ± 10.3, no PH: 12.1 ± 4.5, P = 0.02), LV volumes (ESV: 25.0 ± 15.0 mL, 49.9 ± 29.5 mL, 32.2 ± 13.6 mL, P = 0.027; EDV: 73.6 ± 24.0 mL, 110.6 ± 31.8 mL, 87.8 ± 33.0 mL, P = 0.021) and systolic pulmonary arterial pressure (sPAP: 61.2 ± 22.3 mmHg, 53.6 ± 20.1 mmHg, 31.2 ± 24.6 mmHg, P = 0.001). STRV analysis showed significant differences for apical RV longitudinal strain (RVAS: -7.5% ± 5.6%, -13.3% ± 4.3%, -14

Find and treat or find and lose? Tuberculosis treatment outcomes among screened newly arrived asylum seekers in Germany 2002 to 2014.

Science.gov (United States)

Kuehne, Anna; Hauer, Barbara; Brodhun, Bonita; Haas, Walter; Fiebig, Lena

2018-03-01

BackgroundGermany has a low tuberculosis (TB) incidence. A relevant and increasing proportion of TB cases is diagnosed among asylum seekers upon screening. Aim: We aimed to assess whether cases identified by screening asylum seekers had equally successful and completely reported treatment outcomes as cases diagnosed by passive case finding and contact tracing in the general population. Methods: We analysed characteristics and treatment outcomes of pulmonary TB cases notified in Germany between 2002 and 2014, stratified by mode of case finding. We performed three multivariable analyses with different dependent variables: Model A: successful vs all other outcomes, Model B: successful vs documented non-successful clinical outcome and Model C: known outcome vs lost to follow-up. Results: TB treatment success was highest among cases identified by contact tracing (87%; 3,139/3,591), followed by passive case finding (74%; 28,804/39,019) and by screening asylum seekers (60%; 884/1,474). Cases identified by screening asylum seekers had 2.4 times higher odds of not having a successful treatment outcome as opposed to all other outcomes (A), 1.4 times higher odds of not having a successful treatment outcome as opposed to known non-successful outcomes (B) and 2.3 times higher odds of loss to follow-up (C) than cases identified by passive case finding. Conclusion: Screened asylum seekers had poorer treatment outcomes and were more often lost to follow-up. Linking patients to treatment facilities and investigating potential barriers to treatment completion are needed to secure screening benefits for asylum seekers and communities.

Find and treat or find and lose? Tuberculosis treatment outcomes among screened newly arrived asylum seekers in Germany 2002 to 2014

Science.gov (United States)

Kuehne, Anna; Hauer, Barbara; Brodhun, Bonita; Haas, Walter; Fiebig, Lena

2018-01-01

Background Germany has a low tuberculosis (TB) incidence. A relevant and increasing proportion of TB cases is diagnosed among asylum seekers upon screening. Aim: We aimed to assess whether cases identified by screening asylum seekers had equally successful and completely reported treatment outcomes as cases diagnosed by passive case finding and contact tracing in the general population. Methods: We analysed characteristics and treatment outcomes of pulmonary TB cases notified in Germany between 2002 and 2014, stratified by mode of case finding. We performed three multivariable analyses with different dependent variables: Model A: successful vs all other outcomes, Model B: successful vs documented non-successful clinical outcome and Model C: known outcome vs lost to follow-up. Results: TB treatment success was highest among cases identified by contact tracing (87%; 3,139/3,591), followed by passive case finding (74%; 28,804/39,019) and by screening asylum seekers (60%; 884/1,474). Cases identified by screening asylum seekers had 2.4 times higher odds of not having a successful treatment outcome as opposed to all other outcomes (A), 1.4 times higher odds of not having a successful treatment outcome as opposed to known non-successful outcomes (B) and 2.3 times higher odds of loss to follow-up (C) than cases identified by passive case finding. Conclusion: Screened asylum seekers had poorer treatment outcomes and were more often lost to follow-up. Linking patients to treatment facilities and investigating potential barriers to treatment completion are needed to secure screening benefits for asylum seekers and communities. PMID:29560856

Accuracy of MRI findings in chronic lateral ankle ligament injury: Comparison with surgical findings

Energy Technology Data Exchange (ETDEWEB)

Park, H.-J. [Department of Radiology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Department of Radiology, Kangwon National University, School of Medicine, Chuncheon (Korea, Republic of); Cha, S.-D. [Department of Orthopedic Surgery, Myongji Hospital, Kwandong University, College of Medicine, Koyang (Korea, Republic of); Kim, S.S. [Department of Radiology, Kangwon National University, School of Medicine, Chuncheon (Korea, Republic of); Rho, M.-H., E-mail: parkhiji@kangwon.ac.kr [Department of Radiology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Kwag, H.-J. [Department of Radiology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Park, N.-H. [Department of Radiology, Myongji Hospital, Kwandong University, College of Medicine, Koyang (Korea, Republic of); Lee, S.-Y. [Department of Radiology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

2012-04-15

Aim: To evaluate the accuracy of magnetic resonance imaging (MRI) findings in chronic lateral ankle ligament injury in comparison with that of surgical findings. Materials and methods: Forty-eight cases (25 men, 23 women, mean age 36 years) of clinically suspected chronic ankle ligament injury underwent MRI studies and surgery. Sagittal, coronal, and axial, T1-weighted, spin-echo, proton density and T2-weighted, fast spin-echo images with fat saturation were obtained in all patients. MRI examinations were read in consensus by two fellowship-trained academic musculoskeletal radiologists who evaluated the lateral ankle ligaments, including the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL) without clinical information. The results of the MRI studies were then compared with the surgical findings. Results: The MRI findings of ATFL injury showed a sensitivity of detection of complete tears of 75% and specificity of 86%. The sensitivity of detection of partial tears was 75% and the specificity was 78%. The sensitivity of detection of sprains was 44% and the specificity was 88%. Regarding the MRI findings of CFL injury, the sensitivity of detection of complete tears was 50% and the specificity was 98%. The sensitivity of detection of partial tear was 83% and the specificity was 93%. The sensitivity of detection of sprains was 100% and the specificity was 90%. Regarding the ATFL, the accuracies of detection were 88, 58, 77, and 85% for no injury, sprain, partial tear, and complete tear, respectively, and for the CFL the accuracies of detection were 90, 90, 92, and 96% for no injury, sprain, partial tear, and complete tear, respectively. Conclusions: The diagnosis of a complete tear of the ATFL on MRI is more sensitive than the diagnosis of a complete tear of the CFL. MRI findings of CFL injury are diagnostically specific but are not sensitive. However, only normal findings and complete tears were statistically significant between ATFL and CFL (p

Accuracy of MRI findings in chronic lateral ankle ligament injury: Comparison with surgical findings

International Nuclear Information System (INIS)

Park, H.-J.; Cha, S.-D.; Kim, S.S.; Rho, M.-H.; Kwag, H.-J.; Park, N.-H.; Lee, S.-Y.

2012-01-01

Aim: To evaluate the accuracy of magnetic resonance imaging (MRI) findings in chronic lateral ankle ligament injury in comparison with that of surgical findings. Materials and methods: Forty-eight cases (25 men, 23 women, mean age 36 years) of clinically suspected chronic ankle ligament injury underwent MRI studies and surgery. Sagittal, coronal, and axial, T1-weighted, spin-echo, proton density and T2-weighted, fast spin-echo images with fat saturation were obtained in all patients. MRI examinations were read in consensus by two fellowship-trained academic musculoskeletal radiologists who evaluated the lateral ankle ligaments, including the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL) without clinical information. The results of the MRI studies were then compared with the surgical findings. Results: The MRI findings of ATFL injury showed a sensitivity of detection of complete tears of 75% and specificity of 86%. The sensitivity of detection of partial tears was 75% and the specificity was 78%. The sensitivity of detection of sprains was 44% and the specificity was 88%. Regarding the MRI findings of CFL injury, the sensitivity of detection of complete tears was 50% and the specificity was 98%. The sensitivity of detection of partial tear was 83% and the specificity was 93%. The sensitivity of detection of sprains was 100% and the specificity was 90%. Regarding the ATFL, the accuracies of detection were 88, 58, 77, and 85% for no injury, sprain, partial tear, and complete tear, respectively, and for the CFL the accuracies of detection were 90, 90, 92, and 96% for no injury, sprain, partial tear, and complete tear, respectively. Conclusions: The diagnosis of a complete tear of the ATFL on MRI is more sensitive than the diagnosis of a complete tear of the CFL. MRI findings of CFL injury are diagnostically specific but are not sensitive. However, only normal findings and complete tears were statistically significant between ATFL and CFL (p

Empirical spatial econometric modelling of small scale neighbourhood

Science.gov (United States)

Gerkman, Linda

2012-07-01

The aim of the paper is to model small scale neighbourhood in a house price model by implementing the newest methodology in spatial econometrics. A common problem when modelling house prices is that in practice it is seldom possible to obtain all the desired variables. Especially variables capturing the small scale neighbourhood conditions are hard to find. If there are important explanatory variables missing from the model, the omitted variables are spatially autocorrelated and they are correlated with the explanatory variables included in the model, it can be shown that a spatial Durbin model is motivated. In the empirical application on new house price data from Helsinki in Finland, we find the motivation for a spatial Durbin model, we estimate the model and interpret the estimates for the summary measures of impacts. By the analysis we show that the model structure makes it possible to model and find small scale neighbourhood effects, when we know that they exist, but we are lacking proper variables to measure them.

School Health: Findings from Evaluated Programs.

Science.gov (United States)

Public Health Service (DHHS), Rockville, MD. Office of Disease Prevention and Health Promotion.

This publication presents findings from evaluations of many school health programs from across the United States. Each program includes at least one of the following eight components of a comprehensive school health program: health education, clinical services, counseling and mental health services, school environment, school food programs,…

Finding cis-regulatory modules in Drosophila using phylogenetic hidden Markov models

DEFF Research Database (Denmark)

Wong, Wendy S W; Nielsen, Rasmus

2007-01-01

MOTIVATION: Finding the regulatory modules for transcription factors binding is an important step in elucidating the complex molecular mechanisms underlying regulation of gene expression. There are numerous methods available for solving this problem, however, very few of them take advantage of th...

A methodology for including wall roughness effects in k-ε low-Reynolds turbulence models

International Nuclear Information System (INIS)

Ambrosini, W.; Pucciarelli, A.; Borroni, I.

2015-01-01

Highlights: • A model for taking into account wall roughness in low-Reynolds k-ε models is presented. • The model is subjected to a first validation to show its potential in general applications. • The application of the model in predicting heat transfer to supercritical fluids is also discussed. - Abstract: A model accounting for wall roughness effects in k-ε low-Reynolds turbulence models is described in the present paper. In particular, the introduction in the transport equations of k and ε of additional source terms related to roughness, based on simple assumptions and dimensional relationships, is proposed. An objective of the present paper, in addition to obtaining more realistic predictions of wall friction, is the application of the proposed model to the study of heat transfer to supercritical fluids. A first validation of the model is reported. The model shows the capability of predicting, at least qualitatively, some of the most important trends observed when dealing with rough pipes in very different flow conditions. Qualitative comparisons with some DNS data available in literature are also performed. Further analyses provided promising results concerning the ability of the model in reproducing the trend of friction factor when varying the flow conditions, though improvements are necessary for achieving better quantitative accuracy. First applications of the model in simulating heat transfer to supercritical fluids are also described, showing the capability of the model to affect the predictions of these heat transfer phenomena, in particular in the vicinity of the pseudo-critical conditions. A more extended application of the model to relevant deteriorated heat transfer conditions will clarify the usefulness of this modelling methodology in improving predictions of these difficult phenomena. Whatever the possible success in this particular application that motivated its development, this approach suggests a general methodology for accounting

A case of brain SLE: MRI findings

Energy Technology Data Exchange (ETDEWEB)

Kim, Myung Soon; Kim, Seung Min [Wonju College of Medicine, Yonsei University, Wonju (Korea, Republic of)

1992-01-15

Systemic lupus erythematosus(SLE) is an autoimmune disease characterized by multisystem involvement including central nervous system and various neurologic symptoms. The authors experienced a case of brain SLE and report MRI and other neuroimaging findings.

Ultrasonographic findings of Kikuchi cervical lymphadenopathy in children

Energy Technology Data Exchange (ETDEWEB)

Kim, Ji Young; Lee, Hyun Ju; Yun, Bo La [Seoul National University Bundang Hospital, Seongnam (Korea, Republic of)

2016-03-15

The purpose of this study was to analyze the ultrasonographic (USG) findings of Kikuchi cervical lymphadenopathy in pediatric patients. Between April 2007 and September 2016, 84 children (42 male and 42 female; mean±standard deviation age, 12.9±3.2 years; range, 5 to 18 years) confirmed with Kikuchi disease were enrolled. Clinical findings and USG findings of Kikuchi cervical lymphadenopathy were retrospectively reviewed. Localized symptoms, systemic symptoms, and laboratory findings including the white blood cell count, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) were analyzed. An analysis of the USG findings included evaluation of the location, size, and presence of intranodal abscess; intranodal calcification; perinodal fat swelling; localized fluid collection; and loss of nodal echogenic hilum. Among the patients, 49 (58%) showed localized tenderness at the cervical lymphadenopathy. Fever was present in 55 (66%), while 27 (32%) had prolonged fever. Of 74 with lab results, 54 (73%) had leukopenia but none had leukocytosis. Among the same 74, there was a high ESR (>50 mm/hr) in 10 (14%) and a high CRP level (>5 mg/dL) in seven (9%). The USG findings of most of the patients (n=72, 86%) showed unilateral neck involvement, especially in the left side neck (45 of 72, 63%). The most common site of Kikuchi lymphadenopathy involvement was the area at cervical lymph node level V, at the posterior triangle (n=77, 92%). Conglomerated nodal distribution (n=57, 68%), preserved central nodal echogenic hilum (n=84, 98%), and perinodal fat swelling (n=55, 65%) were common USG findings in the children with Kikuchi. In addition, multiple cervical lymph nodes showed a relatively even size distribution (n=73, 87%). The common USG findings of Kikuchi disease in the pediatric population of our study were multiple conglomerated unilateral cervical lymphadenopathy showing perinodal fat swelling and even size distribution.

Non-local modelling of cyclic thermal shock damage including parameter estimation

NARCIS (Netherlands)

Damhof, F.; Brekelmans, W.A.M.; Geers, M.G.D.

2011-01-01

In this paper, rate dependent evolution laws are identified and characterized to model the mechanical (elasticity-based) and thermal damage occurring in coarse grain refractory material subject to cyclic thermal shock. The interacting mechanisms for elastic deformation driven damage induced by

Clinical, laboratory, and hemostatic findings in cats with naturally occurring sepsis.

Science.gov (United States)

Klainbart, Sigal; Agi, Limor; Bdolah-Abram, Tali; Kelmer, Efrat; Aroch, Itamar

2017-11-01

OBJECTIVE To characterize clinical and laboratory findings in cats with naturally occurring sepsis, emphasizing hemostasis-related findings, and evaluate these variables for associations with patient outcomes. DESIGN Prospective, observational, clinical study. ANIMALS 31 cats with sepsis and 33 healthy control cats. PROCEDURES Data collected included history; clinical signs; results of hematologic, serum biochemical, and hemostatic tests; diagnosis; and outcome (survival vs death during hospitalization or ≤ 30 days after hospital discharge). Differences between cats with and without sepsis and associations between variables of interest and death were analyzed statistically. RESULTS The sepsis group included cats with pyothorax (n = 10), septic peritonitis (7), panleukopenia virus infection (5), bite wounds (5), abscesses and diffuse cellulitis (3), and pyometra (1). Common clinical abnormalities included dehydration (21 cats), lethargy (21), anorexia (18), pale mucous membranes (15), and dullness (15). Numerous clinicopathologic abnormalities were identified in cats with sepsis; novel findings included metarubricytosis, hypertriglyceridemia, and high circulating muscle enzyme activities. Median activated partial thromboplastin time and plasma D-dimer concentrations were significantly higher, and total protein C and antithrombin activities were significantly lower, in the sepsis group than in healthy control cats. Disseminated intravascular coagulopathy was uncommon (4/22 [18%] cats with sepsis). None of the clinicopathologic abnormalities were significantly associated with death on multivariate analysis. CONCLUSIONS AND CLINICAL RELEVANCE Cats with sepsis had multiple hematologic, biochemical, and hemostatic abnormalities on hospital admission, including several findings suggestive of hemostatic derangement. Additional research including larger numbers of cats is needed to further investigate these findings and explore associations with outcome.

Fetal MRI: incidental findings in the mother

Energy Technology Data Exchange (ETDEWEB)

Abdullah, Selwan B. [University of Maryland Medical Center, Diagnostic Radiology and Nuclear Medicine, Baltimore, MD (United States); University of Minnesota, Medical School, Minneapolis, MN (United States); Dietz, Kelly R.; Holm, Tara L. [University of Minnesota, Department of Radiology, Minneapolis, MN (United States)

2016-11-15

Fetal magnetic resonance imaging (MRI) is a routinely used tool in prenatal diagnosis; however, there is a lack of studies evaluating incidental findings observed in the mother. This study describes and quantifies incidental findings observed in the mother during fetal MRI. We reviewed all fetal MRI studies at the University of Minnesota Medical Center from February 2008 to September 2014. Two pediatric radiologists retrospectively conducted a consensus evaluation. The maternal findings were categorized into neurologic, gynecologic, urinary, gastrointestinal and musculoskeletal. Hydronephrosis consistent with the stage of pregnancy was recorded but was not included as an abnormal finding. Abnormal findings were classified into three groups, depending on their clinical significance: level I (low), level II (medium) and level III (high). We evaluated 332 pregnant patients with a mean age of 29.3 years and a mean gestational age of 29 weeks. Of these, 55.4% had at least 1 incidental finding, for a total of 262 incidental maternal findings. Of the 262 abnormalities, 113 (43.1%) were neurologic, 69 were gynecologic (26.3%), 36 (13.7%) urinary, 24 (9.2%) gastrointestinal and 20 (7.6%) musculoskeletal. Of the 262 incidental findings, 237 (90.5%) were level I, 24 (9.2%) were level II and 1 (0.4%) was level III. Our results suggest that although the vast majority of incidental maternal findings are benign, more significant findings are still encountered and should be expected. (orig.)

Fetal MRI: incidental findings in the mother

International Nuclear Information System (INIS)

Abdullah, Selwan B.; Dietz, Kelly R.; Holm, Tara L.

2016-01-01

Fetal magnetic resonance imaging (MRI) is a routinely used tool in prenatal diagnosis; however, there is a lack of studies evaluating incidental findings observed in the mother. This study describes and quantifies incidental findings observed in the mother during fetal MRI. We reviewed all fetal MRI studies at the University of Minnesota Medical Center from February 2008 to September 2014. Two pediatric radiologists retrospectively conducted a consensus evaluation. The maternal findings were categorized into neurologic, gynecologic, urinary, gastrointestinal and musculoskeletal. Hydronephrosis consistent with the stage of pregnancy was recorded but was not included as an abnormal finding. Abnormal findings were classified into three groups, depending on their clinical significance: level I (low), level II (medium) and level III (high). We evaluated 332 pregnant patients with a mean age of 29.3 years and a mean gestational age of 29 weeks. Of these, 55.4% had at least 1 incidental finding, for a total of 262 incidental maternal findings. Of the 262 abnormalities, 113 (43.1%) were neurologic, 69 were gynecologic (26.3%), 36 (13.7%) urinary, 24 (9.2%) gastrointestinal and 20 (7.6%) musculoskeletal. Of the 262 incidental findings, 237 (90.5%) were level I, 24 (9.2%) were level II and 1 (0.4%) was level III. Our results suggest that although the vast majority of incidental maternal findings are benign, more significant findings are still encountered and should be expected. (orig.)

Interventions to assist health consumers to find reliable online health information: a comprehensive review.

Directory of Open Access Journals (Sweden)

Kenneth Lee

Full Text Available BACKGROUND: Health information on the Internet is ubiquitous, and its use by health consumers prevalent. Finding and understanding relevant online health information, and determining content reliability, pose real challenges for many health consumers. PURPOSE: To identify the types of interventions that have been implemented to assist health consumers to find reliable online health information, and where possible, describe and compare the types of outcomes studied. DATA SOURCES: PubMed, PsycINFO, CINAHL Plus and Cochrane Library databases; WorldCat and Scirus 'gray literature' search engines; and manual review of reference lists of selected publications. STUDY SELECTION: Publications were selected by firstly screening title, abstract, and then full text. DATA EXTRACTION: Seven publications met the inclusion criteria, and were summarized in a data extraction form. The form incorporated the PICOS (Population Intervention Comparators Outcomes and Study Design Model. Two eligible gray literature papers were also reported. DATA SYNTHESIS: Relevant data from included studies were tabulated to enable descriptive comparison. A brief critique of each study was included in the tables. This review was unable to follow systematic review methods due to the paucity of research and humanistic interventions reported. LIMITATIONS: While extensive, the gray literature search may have had limited reach in some countries. The paucity of research on this topic limits conclusions that may be drawn. CONCLUSIONS: The few eligible studies predominantly adopted a didactic approach to assisting health consumers, whereby consumers were either taught how to find credible websites, or how to use the Internet. Common types of outcomes studied include knowledge and skills pertaining to Internet use and searching for reliable health information. These outcomes were predominantly self-assessed by participants. There is potential for further research to explore other avenues for

Interventions to assist health consumers to find reliable online health information: a comprehensive review.

Science.gov (United States)

Lee, Kenneth; Hoti, Kreshnik; Hughes, Jeffery D; Emmerton, Lynne M

2014-01-01

Health information on the Internet is ubiquitous, and its use by health consumers prevalent. Finding and understanding relevant online health information, and determining content reliability, pose real challenges for many health consumers. To identify the types of interventions that have been implemented to assist health consumers to find reliable online health information, and where possible, describe and compare the types of outcomes studied. PubMed, PsycINFO, CINAHL Plus and Cochrane Library databases; WorldCat and Scirus 'gray literature' search engines; and manual review of reference lists of selected publications. Publications were selected by firstly screening title, abstract, and then full text. Seven publications met the inclusion criteria, and were summarized in a data extraction form. The form incorporated the PICOS (Population Intervention Comparators Outcomes and Study Design) Model. Two eligible gray literature papers were also reported. Relevant data from included studies were tabulated to enable descriptive comparison. A brief critique of each study was included in the tables. This review was unable to follow systematic review methods due to the paucity of research and humanistic interventions reported. While extensive, the gray literature search may have had limited reach in some countries. The paucity of research on this topic limits conclusions that may be drawn. The few eligible studies predominantly adopted a didactic approach to assisting health consumers, whereby consumers were either taught how to find credible websites, or how to use the Internet. Common types of outcomes studied include knowledge and skills pertaining to Internet use and searching for reliable health information. These outcomes were predominantly self-assessed by participants. There is potential for further research to explore other avenues for assisting health consumers to find reliable online health information, and to assess outcomes via objective measures.

Networking in autism: leveraging genetic, biomarker and model system findings in the search for new treatments.

Science.gov (United States)

Veenstra-VanderWeele, Jeremy; Blakely, Randy D

2012-01-01

Autism Spectrum Disorder (ASD) is a common neurodevelopmental disorder affecting approximately 1% of children. ASD is defined by core symptoms in two domains: negative symptoms of impairment in social and communication function, and positive symptoms of restricted and repetitive behaviors. Available treatments are inadequate for treating both core symptoms and associated conditions. Twin studies indicate that ASD susceptibility has a large heritable component. Genetic studies have identified promising leads, with converging insights emerging from single-gene disorders that bear ASD features, with particular interest in mammalian target of rapamycin (mTOR)-linked synaptic plasticity mechanisms. Mouse models of these disorders are revealing not only opportunities to model behavioral perturbations across species, but also evidence of postnatal rescue of brain and behavioral phenotypes. An intense search for ASD biomarkers has consistently pointed to elevated platelet serotonin (5-HT) levels and a surge in brain growth in the first 2 years of life. Following a review of the diversity of ASD phenotypes and its genetic origins and biomarkers, we discuss opportunities for translation of these findings into novel ASD treatments, focusing on mTor- and 5-HT-signaling pathways, and their possible intersection. Paralleling the progress made in understanding the root causes of rare genetic syndromes that affect cognitive development, we anticipate progress in models systems using bona fide ASD-associated molecular changes that have the potential to accelerate the development of ASD diagnostics and therapeutics.