WorldWideScience

Sample records for single model procedure

  1. A single model procedure for estimating tank calibration equations

    International Nuclear Information System (INIS)

    Liebetrau, A.M.

    1997-10-01

    A fundamental component of any accountability system for nuclear materials is a tank calibration equation that relates the height of liquid in a tank to its volume. Tank volume calibration equations are typically determined from pairs of height and volume measurements taken in a series of calibration runs. After raw calibration data are standardized to a fixed set of reference conditions, the calibration equation is typically fit by dividing the data into several segments--corresponding to regions in the tank--and independently fitting the data for each segment. The estimates obtained for individual segments must then be combined to obtain an estimate of the entire calibration function. This process is tedious and time-consuming. Moreover, uncertainty estimates may be misleading because it is difficult to properly model run-to-run variability and between-segment correlation. In this paper, the authors describe a model whose parameters can be estimated simultaneously for all segments of the calibration data, thereby eliminating the need for segment-by-segment estimation. The essence of the proposed model is to define a suitable polynomial to fit to each segment and then extend its definition to the domain of the entire calibration function, so that it (the entire calibration function) can be expressed as the sum of these extended polynomials. The model provides defensible estimates of between-run variability and yields a proper treatment of between-segment correlations. A portable software package, called TANCS, has been developed to facilitate the acquisition, standardization, and analysis of tank calibration data. The TANCS package was used for the calculations in an example presented to illustrate the unified modeling approach described in this paper. With TANCS, a trial calibration function can be estimated and evaluated in a matter of minutes

  2. Detection Procedure for a Single Additive Outlier and Innovational Outlier in a Bilinear Model

    Directory of Open Access Journals (Sweden)

    Azami Zaharim

    2007-01-01

    Full Text Available A single outlier detection procedure for data generated from BL(1,1,1,1 models is developed. It is carried out in three stages. Firstly, the measure of impact of an IO and AO denoted by IO ω , AO ω , respectively are derived based on least squares method. Secondly, test statistics and test criteria are defined for classifying an observation as an outlier of its respective type. Finally, a general single outlier detection procedure is presented to distinguish a particular type of outlier at a time point t.

  3. Using genetic algorithm and TOPSIS for Xinanjiang model calibration with a single procedure

    Science.gov (United States)

    Cheng, Chun-Tian; Zhao, Ming-Yan; Chau, K. W.; Wu, Xin-Yu

    2006-01-01

    Genetic Algorithm (GA) is globally oriented in searching and thus useful in optimizing multiobjective problems, especially where the objective functions are ill-defined. Conceptual rainfall-runoff models that aim at predicting streamflow from the knowledge of precipitation over a catchment have become a basic tool for flood forecasting. The parameter calibration of a conceptual model usually involves the multiple criteria for judging the performances of observed data. However, it is often difficult to derive all objective functions for the parameter calibration problem of a conceptual model. Thus, a new method to the multiple criteria parameter calibration problem, which combines GA with TOPSIS (technique for order performance by similarity to ideal solution) for Xinanjiang model, is presented. This study is an immediate further development of authors' previous research (Cheng, C.T., Ou, C.P., Chau, K.W., 2002. Combining a fuzzy optimal model with a genetic algorithm to solve multi-objective rainfall-runoff model calibration. Journal of Hydrology, 268, 72-86), whose obvious disadvantages are to split the whole procedure into two parts and to become difficult to integrally grasp the best behaviors of model during the calibration procedure. The current method integrates the two parts of Xinanjiang rainfall-runoff model calibration together, simplifying the procedures of model calibration and validation and easily demonstrated the intrinsic phenomenon of observed data in integrity. Comparison of results with two-step procedure shows that the current methodology gives similar results to the previous method, is also feasible and robust, but simpler and easier to apply in practice.

  4. A single-photon ecat reconstruction procedure based on a PSF model

    International Nuclear Information System (INIS)

    Ying-Lie, O.

    1984-01-01

    Emission Computed Axial Tomography (ECAT) has been applied in nuclear medicine for the past few years. Owing to attenuation and scatter along the ray path, adequate correction methods are required. In this thesis, a correction method for attenuation, detector response and Compton scatter has been proposed. The method developed is based on a PSF model. The parameters of the models were derived by fitting experimental and simulation data. Because of its flexibility, a Monte Carlo simulation method has been employed. Using the PSF models, it was found that the ECAT problem can be described by the added modified equation. Application of the reconstruction procedure on simulation data yield satisfactory results. The algorithm tends to amplify noise and distortion in the data, however. Therefore, the applicability of the method on patient studies remain to be seen. (Auth.)

  5. Procedural facade variations from a single layout

    KAUST Repository

    Bao, Fan

    2013-02-19

    We introduce a framework to generate many variations of a facade design that look similar to a given facade layout. Starting from an input image, the facade is hierarchically segmented and labeled with a collection of manual and automatic tools. The user can then model constraints that should be maintained in any variation of the input facade design. Subsequently, facade variations are generated for different facade sizes, where multiple variations can be produced for a certain size. Computing such new facade variations has many unique challenges, and we propose a new algorithm based on interleaving heuristic search and quadratic programming. In contrast to most previous work, we focus on the generation of new design variations and not on the automatic analysis of the input\\'s structure. Adding a modeling step with the user in the loop ensures that our results routinely are of high quality. © 2013 ACM.

  6. OSL sensitivity changes during single aliquot procedures: Computer simulations

    DEFF Research Database (Denmark)

    McKeever, S.W.S.; Agersnap Larsen, N.; Bøtter-Jensen, L.

    1997-01-01

    We present computer simulations of sensitivity changes obtained during single aliquot, regeneration procedures. The simulations indicate that the sensitivity changes are the combined result of shallow trap and deep trap effects. Four separate processes have been identified. Although procedures can...... dose used and the natural dose. However, the sensitivity changes appear only weakly dependent upon added dose, suggesting that the SARA single aliquot technique may be a suitable method to overcome the sensitivity changes. (C) 1997 Elsevier Science Ltd....

  7. Typical NRC inspection procedures for model plant

    International Nuclear Information System (INIS)

    Blaylock, J.

    1984-01-01

    A summary of NRC inspection procedures for a model LEU fuel fabrication plant is presented. Procedures and methods for combining inventory data, seals, measurement techniques, and statistical analysis are emphasized

  8. Single Item Inventory Models

    NARCIS (Netherlands)

    E.M. Bazsa-Oldenkamp; P. den Iseger

    2001-01-01

    textabstractThis paper extends a fundamental result about single-item inventory systems. This approach allows more general performance measures, demand processes and order policies, and leads to easier analysis and implementation, than prior research. We obtain closed form expressions for the

  9. LIDAR forest inventory with single-tree, double- and single-phase procedures

    Science.gov (United States)

    Robert C. Parker; David L. Evans

    2009-01-01

    Light Detection and Ranging (LIDAR) data at 0.5- to 2-m postings were used with doublesample, stratified inventory procedures involving single-tree attribute relationships in mixed, natural, and planted species stands to yield sampling errors (one-half the confidence interval expressed as a percentage of the mean) ranging from ±2.1 percent to ±11.5...

  10. Procedural Personas for Player Decision Modeling and Procedural Content Generation

    DEFF Research Database (Denmark)

    Holmgård, Christoffer

    2016-01-01

    ." These methods for constructing procedural personas are then integrated with existing procedural content generation systems, acting as critics that shape the output of these systems, optimizing generated content for different personas and by extension, different kinds of players and their decision making styles......How can player models and artificially intelligent (AI) agents be useful in early-stage iterative game and simulation design? One answer may be as ways of generating synthetic play-test data, before a game or level has ever seen a player, or when the sampled amount of play test data is very low....... This thesis explores methods for creating low-complexity, easily interpretable, generative AI agents for use in game and simulation design. Based on insights from decision theory and behavioral economics, the thesis investigates how player decision making styles may be defined, operationalised, and measured...

  11. Meconium Ileus–Is a Single Surgical Procedure Adequate?

    Directory of Open Access Journals (Sweden)

    Hagith Nagar

    2006-07-01

    Full Text Available Meconium ileus is one of the gastrointestinal manifestations of cystic fibrosis (CF, and affects 15% of neonates. The condition results from the accumulation of sticky inspissated meconium. Both nonoperative and operative therapies may be effective in relieving obstruction. The treatment of choice for uncomplicated meconium ileus is the use of enteral N-acetylcysteine or Gastrografin enemata. Once such therapy fails, surgery is indicated. A number of operative procedures are in use, including Bishop-Koop enterostomy, T-tube irrigation, resection and primary anastomosis, and enterotomy with irrigation and primary closure. During the period 1991-2003, five newborns required surgical intervention for uncomplicated meconium ileus. None responded to conservative management. All were males, including one set of twins. All underwent laparotomy, enterotomy, appendectomy, irrigation and closure of enterotomy. None required a second surgical procedure. CF was confirmed in all, and in each case, both parents were found to be genetic carriers of a mutational form of CF. A single surgical intervention is preferable in these patients, in view of the high rate of pulmonary involvement in CF patients. Enterotomy, irrigation and primary closure are the treatment of choice for uncomplicated meconium ileus.

  12. A model of procedural and distributive fairness

    NARCIS (Netherlands)

    Krawczyk, M.W.

    2007-01-01

    This paper presents a new model aimed at predicting behav- ior in games involving a randomized allocation procedure. It is designed to capture the relative importance and interaction between procedural justice (defined crudely in terms of the share of one's expected outcome in the sum of all

  13. Procedural Modeling for Digital Cultural Heritage

    Directory of Open Access Journals (Sweden)

    Müller Pascal

    2009-01-01

    Full Text Available The rapid development of computer graphics and imaging provides the modern archeologist with several tools to realistically model and visualize archeological sites in 3D. This, however, creates a tension between veridical and realistic modeling. Visually compelling models may lead people to falsely believe that there exists very precise knowledge about the past appearance of a site. In order to make the underlying uncertainty visible, it has been proposed to encode this uncertainty with different levels of transparency in the rendering, or of decoloration of the textures. We argue that procedural modeling technology based on shape grammars provides an interesting alternative to such measures, as they tend to spoil the experience for the observer. Both its efficiency and compactness make procedural modeling a tool to produce multiple models, which together sample the space of possibilities. Variations between the different models express levels of uncertainty implicitly, while letting each individual model keeping its realistic appearance. The underlying, structural description makes the uncertainty explicit. Additionally, procedural modeling also yields the flexibility to incorporate changes as knowledge of an archeological site gets refined. Annotations explaining modeling decisions can be included. We demonstrate our procedural modeling implementation with several recent examples.

  14. A procedure for building product models

    DEFF Research Database (Denmark)

    Hvam, Lars; Riis, Jesper; Malis, Martin

    2001-01-01

    This article presents a procedure for building product models to support the specification processes dealing with sales, design of product variants and production preparation. The procedure includes, as the first phase, an analysis and redesign of the business processes, which are to be supported...... with product models. The next phase includes an analysis of the product assortment, and the set up of a so-called product master. Finally the product model is designed and implemented using object oriented modelling. The procedure is developed in order to ensure that the product models constructed are fit...... for the business processes they support, and properly structured and documented, in order to facilitate that the systems can be maintained continually and further developed. The research has been carried out at the Centre for Industrialisation of Engineering, Department of Manufacturing Engineering, Technical...

  15. On Realism of Architectural Procedural Models

    Czech Academy of Sciences Publication Activity Database

    Beneš, J.; Kelly, T.; Děchtěrenko, Filip; Křivánek, J.; Müller, P.

    2017-01-01

    Roč. 36, č. 2 (2017), s. 225-234 ISSN 0167-7055 Grant - others:AV ČR(CZ) StrategieAV21/14 Program:StrategieAV Institutional support: RVO:68081740 Keywords : realism * procedural modeling * architecture Subject RIV: IN - Informatics, Computer Science Impact factor: 1.611, year: 2016

  16. On Realism of Architectural Procedural Models

    Czech Academy of Sciences Publication Activity Database

    Beneš, J.; Kelly, T.; Děchtěrenko, Filip; Křivánek, J.; Müller, P.

    2017-01-01

    Roč. 36, č. 2 (2017), s. 225-234 ISSN 0167-7055 Grant - others:AV ČR(CZ) StrategieAV21/14 Program:StrategieAV Institutional support: RVO:68081740 Keywords : realism * procedural modeling * architecture Subject RIV: IN - Informatics, Computer Science OBOR OECD: Cognitive sciences Impact factor: 1.611, year: 2016

  17. 76 FR 34801 - Petition for Modification of Single Car Air Brake Test Procedures

    Science.gov (United States)

    2011-06-14

    ... reference in 49 CFR 232.305) is intended for freight cars with automatic brake systems that are...] Petition for Modification of Single Car Air Brake Test Procedures In accordance with Part 232 of Title 49... Railroad Administration (FRA) grant a modification of the single car air brake test procedures as...

  18. Evaluation procedures for single axis sinusoidal test to design spectrum requirements

    International Nuclear Information System (INIS)

    Sun, P.C.; Javid, A.

    1983-01-01

    Two simple procedures are provided in this paper for the purpose of evaluating the adequacy of a single frequency single axis test. For the purpose of evaluating the adequacy of single frequency test to meet broad-band response spectrum requirements, the proposed procedure is based on the equivalence of maximum response of a dynamic system when it is subjected to either type of design input. The required information used for the evaluation is usually recorded and available in the test report. This procedure is applicable to systems with or without closely-spaced modes. When evaluating against broad-band design spectra and multi-axes requirements, an empirical procedure is proposed and it has been found conservative. These two proposed procedures provide a quick assessment on the adequacy of a single frequency test performed earlier. The use of these procedures may eliminate the need of expensive and time consuming equipment re-testing. (orig./HP)

  19. Procedural Content Graphs for Urban Modeling

    Directory of Open Access Journals (Sweden)

    Pedro Brandão Silva

    2015-01-01

    Full Text Available Massive procedural content creation, for example, for virtual urban environments, is a difficult, yet important challenge. While shape grammars are a popular example of effectiveness in architectural modeling, they have clear limitations regarding readability, manageability, and expressive power when addressing a variety of complex structural designs. Moreover, shape grammars aim at geometry specification and do not facilitate integration with other types of content, such as textures or light sources, which could rather accompany the generation process. We present procedural content graphs, a graph-based solution for procedural generation that addresses all these issues in a visual, flexible, and more expressive manner. Besides integrating handling of diverse types of content, this approach introduces collective entity manipulation as lists, seamlessly providing features such as advanced filtering, grouping, merging, ordering, and aggregation, essentially unavailable in shape grammars. Hereby, separated entities can be easily merged or just analyzed together in order to perform a variety of context-based decisions and operations. The advantages of this approach are illustrated via examples of tasks that are either very cumbersome or simply impossible to express with previous grammar approaches.

  20. 49 CFR 232.307 - Modification of the single car air brake test procedures.

    Science.gov (United States)

    2010-10-01

    ... Requirements § 232.307 Modification of the single car air brake test procedures. (a) Request. The AAR or other authorized representative of the railroad industry may seek modification of the single car air brake test... 49 Transportation 4 2010-10-01 2010-10-01 false Modification of the single car air brake test...

  1. On Using Selection Procedures with Binomial Models.

    Science.gov (United States)

    1983-10-01

    eds.), Shinko Tsusho Co. Ltd., Tokyo, Japan , pp. 501-533. Gupta, S. S. and Sobel, M. (1960). Selecting a subset containing the best of several...IA_____3_6r__I____ *TITLE food A$ieweI L TYPE of 09PORT 6 PERIOD COVERED ON USING SELECTION PROCEDURES WITH BINOMIAL MODELS Technical 6. PeSPRFeauS1 ONG. REPORT...ontoedis stoc toeSI. to Ei.,..,t&* toemR.,. 14. SUPPOLEMENTARY MOCTES 19. Rey WORDS (Coatiou. 40 ow.oa* edo if Necesary and #do""&a by block number

  2. Testing Procedure for the Single Fiber Fragmentation Test

    DEFF Research Database (Denmark)

    Feih, Stefanie; Wonsyld, Karen; Minzari, Daniel

    , specimens with one E-glass fiber placed inside an epoxy or polyester matrix were used. Elongating the specimens with a mini tensile tester, which was placed under a microscope, leads to fiber fragmentations. Different bonding strengths between fiber and matrix result in differences in the critical fracture......This report describes the details of the single fiber fragmentation test as conducted at the materials research department (AFM) at Risø. The equipment and specimen manufacture is described in detail. Furthermore, examples of results interpretation are given. For the experiments in this report...... length for the fiber and fracture characteristics....

  3. Robust estimation procedure in panel data model

    Energy Technology Data Exchange (ETDEWEB)

    Shariff, Nurul Sima Mohamad [Faculty of Science of Technology, Universiti Sains Islam Malaysia (USIM), 71800, Nilai, Negeri Sembilan (Malaysia); Hamzah, Nor Aishah [Institute of Mathematical Sciences, Universiti Malaya, 50630, Kuala Lumpur (Malaysia)

    2014-06-19

    The panel data modeling has received a great attention in econometric research recently. This is due to the availability of data sources and the interest to study cross sections of individuals observed over time. However, the problems may arise in modeling the panel in the presence of cross sectional dependence and outliers. Even though there are few methods that take into consideration the presence of cross sectional dependence in the panel, the methods may provide inconsistent parameter estimates and inferences when outliers occur in the panel. As such, an alternative method that is robust to outliers and cross sectional dependence is introduced in this paper. The properties and construction of the confidence interval for the parameter estimates are also considered in this paper. The robustness of the procedure is investigated and comparisons are made to the existing method via simulation studies. Our results have shown that robust approach is able to produce an accurate and reliable parameter estimates under the condition considered.

  4. Single specimen fracture toughness determination procedure using instrumented impact test

    International Nuclear Information System (INIS)

    Rintamaa, R.

    1993-04-01

    In the study a new single specimen test method and testing facility for evaluating dynamic fracture toughness has been developed. The method is based on the application of a new pendulum type instrumented impact tester equipped with and optical crack mouth opening displacement (COD) extensometer. The fracture toughness measurement technique uses the Double Displacement Ratio (DDR) method, which is based on the assumption that the specimen is deformed as two rigid arms that rotate around an apparent centre of rotation. This apparent moves as the crack grows, and the ratio of COD versus specimen displacement changes. As a consequence the onset ductile crack initiation can be detected on the load-displacement curve. Thus, an energy-based fracture toughness can be calculated. In addition the testing apparatus can use specimens with the Double ligament size as compared with the standard Charpy specimen which makes the impact testing more appropriate from the fracture mechanics point of view. The novel features of the testing facility and the feasibility of the new DDR method has been verified by performing an extensive experimental and analytical study. (99 refs., 91 figs., 27 tabs.)

  5. The LET Procedure for Prosthetic Myocontrol: Towards Multi-DOF Control Using Single-DOF Activations.

    Science.gov (United States)

    Nowak, Markus; Castellini, Claudio

    2016-01-01

    Simultaneous and proportional myocontrol of dexterous hand prostheses is to a large extent still an open problem. With the advent of commercially and clinically available multi-fingered hand prostheses there are now more independent degrees of freedom (DOFs) in prostheses than can be effectively controlled using surface electromyography (sEMG), the current standard human-machine interface for hand amputees. In particular, it is uncertain, whether several DOFs can be controlled simultaneously and proportionally by exclusively calibrating the intended activation of single DOFs. The problem is currently solved by training on all required combinations. However, as the number of available DOFs grows, this approach becomes overly long and poses a high cognitive burden on the subject. In this paper we present a novel approach to overcome this problem. Multi-DOF activations are artificially modelled from single-DOF ones using a simple linear combination of sEMG signals, which are then added to the training set. This procedure, which we named LET (Linearly Enhanced Training), provides an augmented data set to any machine-learning-based intent detection system. In two experiments involving intact subjects, one offline and one online, we trained a standard machine learning approach using the full data set containing single- and multi-DOF activations as well as using the LET-augmented data set in order to evaluate the performance of the LET procedure. The results indicate that the machine trained on the latter data set obtains worse results in the offline experiment compared to the full data set. However, the online implementation enables the user to perform multi-DOF tasks with almost the same precision as single-DOF tasks without the need of explicitly training multi-DOF activations. Moreover, the parameters involved in the system are statistically uniform across subjects.

  6. The LET Procedure for Prosthetic Myocontrol: Towards Multi-DOF Control Using Single-DOF Activations.

    Directory of Open Access Journals (Sweden)

    Markus Nowak

    Full Text Available Simultaneous and proportional myocontrol of dexterous hand prostheses is to a large extent still an open problem. With the advent of commercially and clinically available multi-fingered hand prostheses there are now more independent degrees of freedom (DOFs in prostheses than can be effectively controlled using surface electromyography (sEMG, the current standard human-machine interface for hand amputees. In particular, it is uncertain, whether several DOFs can be controlled simultaneously and proportionally by exclusively calibrating the intended activation of single DOFs. The problem is currently solved by training on all required combinations. However, as the number of available DOFs grows, this approach becomes overly long and poses a high cognitive burden on the subject. In this paper we present a novel approach to overcome this problem. Multi-DOF activations are artificially modelled from single-DOF ones using a simple linear combination of sEMG signals, which are then added to the training set. This procedure, which we named LET (Linearly Enhanced Training, provides an augmented data set to any machine-learning-based intent detection system. In two experiments involving intact subjects, one offline and one online, we trained a standard machine learning approach using the full data set containing single- and multi-DOF activations as well as using the LET-augmented data set in order to evaluate the performance of the LET procedure. The results indicate that the machine trained on the latter data set obtains worse results in the offline experiment compared to the full data set. However, the online implementation enables the user to perform multi-DOF tasks with almost the same precision as single-DOF tasks without the need of explicitly training multi-DOF activations. Moreover, the parameters involved in the system are statistically uniform across subjects.

  7. SAFETY AND EFFECTIVENESS OF SINGLE ANASTOMOSIS DUODENAL SWITCH PROCEDURE: PRELIMINARY RESULT FROM A SINGLE INSTITUTION.

    Science.gov (United States)

    Nelson, Lars; Moon, Rena C; Teixeira, Andre F; Galvão, Manoel; Ramos, Almino; Jawad, Muhammad A

    Single anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S) was introduced into bariatric surgery by Sanchez-Pernaute et al. as an advancement of the biliopancreatic diversion with duodenal switch. To evaluate the SADI-S procedure with regard to weight loss, comorbidity resolution, and complication rate in the super obese population. A retrospective chart review was performed on initial 72 patients who underwent laparoscopic or robot-assisted laparoscopic SADI-S between December 17th, 2013 and July 29th, 2015. A total of 48 female and 21 male patients were included with a mean age of 42.4±10.0 years (range, 22-67). The mean body mass index (BMI) at the time of procedure was 58.4±8.3 kg/m2 (range, 42.3-91.8). Mean length of hospital stay was 4.3±2.6 days (range, 3-24). Thirty-day readmission rate was 4.3% (n=3), due to tachycardia (n=1), deep venous thrombosis (n=1), and viral gastroenteritis (n=1). Thirty-day reoperation rate was 5.8% (n=4) for perforation of the small bowel (n=1), leakage (n=1), duodenal stump leakage (n=1), and diagnostic laparoscopy (n=1). Percentage of excess weight loss (%EWL) was 28.5±8.8 % (range, 13.3-45.0) at three months (n=28), 41.7±11.1 % (range, 19.6-69.6) at six months (n=50), and 61.6±12.0 % (range, 40.1-91.2) at 12 months (n=23) after the procedure. A total of 18 patients (26.1%) presented with type II diabetes mellitus at the time of surgery. Of these patients, 9 (50.0%) had their diabetes resolved, and six (33.3%) had it improved by 6-12 months after SADI-S. SADI-S is a feasible operation with a promising weight loss and diabetes resolution in the super-obese population. Anastomose única em bypass duodenoileal com gastrectomia vertical (SADI-S) foi introduzida na cirurgia bariátrica por Sanchez-Pernaute et al. como um avanço da derivação biliopancreática com switch duodenal. Avaliar o procedimento SADI-S no que diz respeito à perda de peso, resolução de comorbidades e taxa de complicações na popula

  8. Integration of Multiple Non-Normal Checklist Procedures into a Single Checklist Procedure for Transport Aircraft: A Preliminary Investigation

    Science.gov (United States)

    Foernsler, Lynda J.

    1996-01-01

    Checklists are used by the flight crew to properly configure an aircraft for safe flight and to ensure a high level of safety throughout the duration of the flight. In addition, the checklist provides a sequential framework to meet cockpit operational requirements, and it fosters cross-checking of the flight deck configuration among crew members. This study examined the feasibility of integrating multiple checklists for non-normal procedures into a single procedure for a typical transport aircraft. For the purposes of this report, a typical transport aircraft is one that represents a midpoint between early generation aircraft (B-727/737-200 and DC-10) and modern glass cockpit aircraft (B747-400/777 and MD-11). In this report, potential conflicts among non-normal checklist items during multiple failure situations for a transport aircraft are identified and analyzed. The non-normal checklist procedure that would take precedence for each of the identified multiple failure flight conditions is also identified. The rationale behind this research is that potential conflicts among checklist items might exist when integrating multiple checklists for non-normal procedures into a single checklist. As a rule, multiple failures occurring in today's highly automated and redundant system transport aircraft are extremely improbable. In addition, as shown in this analysis, conflicts among checklist items in a multiple failure flight condition are exceedingly unlikely. The possibility of a multiple failure flight condition occurring with a conflict among checklist items is so remote that integration of the non-normal checklists into a single checklist appears to be a plausible option.

  9. A Survey on Procedural Modelling for Virtual Worlds

    NARCIS (Netherlands)

    Smelik, R.M.; Tutenel, T.; Bidarra, R.; Benes, B.

    2014-01-01

    Procedural modelling deals with (semi-)automatic content generation by means of a program or procedure. Among other advantages, its data compression and the potential to generate a large variety of detailed content with reduced human intervention, have made procedural modelling attractive for

  10. ECSPECT prospective multicentre registry for single-port laparoscopic colorectal procedures

    DEFF Research Database (Denmark)

    Weiss, Helmut; Zorron, R; Vestweber, K-H

    2017-01-01

    patients undergoing single-port colorectal surgery were enrolled from 11 European centres between March 2010 and March 2014. Data were analysed to assess patient-, technique- and procedure-dependent parameters. A validated sex-adjusted risk chart was developed for prediction of single-port colorectal......BACKGROUND: The international multicentre registry ECSPECT (European Consensus of Single Port Expertise in Colorectal Treatment) was established to evaluate the general feasibility and safety of single-port colorectal surgery with regard to preoperative risk assessment. METHODS: Consecutive...

  11. Outcomes following the Kawashima procedure for single-ventricle palliation in left atrial isomerism.

    Science.gov (United States)

    Vollebregt, Anne; Pushparajah, Kuberan; Rizvi, Maleeha; Hoschtitzky, Andreas; Anderson, David; Austin, Conal; Tibby, Shane M; Simpson, John

    2012-03-01

    Patients with left atrial isomerism and interrupted inferior vena cava palliated with a superior cavopulmonary connection or Kawashima procedure (KP) have a high incidence of developing pulmonary arteriovenous malformations. The necessity for hepatic vein redirection (HVR) and its timing remains a controversy. We aimed to assess the clinical outcome of patients with left atrial isomerism following a KP. The main end points were death, requirement for HVR and the impact of HVR on oxygen saturation. Retrospective review of 21 patients with a diagnosis of left atrial isomerism, interruption of the inferior vena cava and single-ventricle physiology managed with a KP at a single centre between January 1990 and March 2010. Twenty-one patients had a KP, with 12 subsequently undergoing HVR. There was relatively a constant monthly decrement in the proportion of patients who were free from death or HVR up until 60 months following the KP, with a dramatic increase in the hazard after this time. The Cox proportional hazards regression model demonstrated a reduced early risk for HVR or death in patients who underwent pulmonary artery banding versus arterial shunt as the primary procedure (hazard ratio: 0.10; P = 0.01), and an increased risk with bilateral superior vena cavas (SVCs) (hazard ratio: 3.4; P = 0.04) and age at KP (hazard ratio: 1.02 per month increase in age at KP; P = 0.02). HVR mortality was relatively high with 3 of 12 patients dying in the early postoperative period with profound cyanosis. The timing of HVR after the KP did not influence the postoperative rate of increase in oxygen saturation. These findings confirm that the majority of patients who undergo a KP will require HVR. Patients who are older at the time of the KP or having an initial arterial shunt or bilateral SVCs are at higher risk of HVR or death. The relatively high mortality at HVR was characterized by severe postoperative cyanosis.

  12. A procedure for Building Product Models

    DEFF Research Database (Denmark)

    Hvam, Lars

    1999-01-01

    activities. A basic assumption is that engineers have to take the responsability for building product models to be used in their domain. To do that they must be able to carry out the modeling task on their own without any need for support from computer science experts. This paper presents a set of simple......The application of product modeling in manufacturing companies raises the important question of how to model product knowledge in a comprehensible and efficient way. An important challenge is to qualify engineers to model and specify IT-systems (product models) to support their specification......, easily adaptable concepts and methods from data modeling (object oriented analysis) and domain modeling (product modeling). The concepts are general and can be used for modeling all types of specifications in the different phases in the product life cycle. The modeling techniques presented have been...

  13. Single Whole-Body Cryostimulation Procedure versus Single Dry Sauna Bath: Comparison of Oxidative Impact on Healthy Male Volunteers

    Directory of Open Access Journals (Sweden)

    Paweł Sutkowy

    2015-01-01

    Full Text Available Exposure to extreme heat and cold is one of the environmental factors whose action is precisely based on the mechanisms involving free radicals. Fluctuations in ambient temperature are among the agents that toughen the human organism. The goal of the study was to evaluate the impact of extremely high (dry sauna, DS and low (whole-body cryostimulation, WBC environmental temperatures on the oxidant-antioxidant equilibrium in the blood of healthy male subjects. The subjects performed a single DS bath (n=10; 26.2 ± 4.6 years and a single WBC procedure (n=15; 27.5 ± 3.1 years. In the subjects’ blood taken immediately before and 20 min after the interventions, the activity of superoxide dismutase (SOD, catalase (CAT, and glutathione peroxidase (GPx and the concentration of thiobarbituric acid reactive substances in erythrocytes (TBARSer and blood plasma (TBARSpl were determined. Single WBC and DS procedures induced an increase in the activity of SOD and GPx, as well as SOD and CAT, respectively. The SOD activity was higher after WBC than after DS. Extremely high and low temperatures probably induce the formation of reactive oxygen species in the organisms of healthy men and, therefore, disturb the oxidant-antioxidant balance.

  14. Single supplier single retailer inventory model controlled by the reorder and shipping points with sharing information

    Science.gov (United States)

    Ho, Wen-Tsung; Hsiao, Yu-Cheng

    2012-04-01

    This study investigated the integrated stochastic inventory problem for a two-stage supply chain consisting of a single retailer and a single supplier. By using batch shipment policy, the expected total cost can be significantly reduced. An equally sized batch shipment model, controlled by both the reorder and shipping points, with sharing information by enterprise resource planning and radio frequency identification is constructed. The problem is solved optimally by the proposed algorithm that determines the economic lot size, the optimal batch sizes and number of batches. A numerical example is included to illustrate the algorithmic procedures and to prove that the model controlled both by the reorder and shipping points is superior to the classic model controlled only by the reorder point.

  15. Improvement and Validation of Weld Residual Stress Modelling Procedure

    International Nuclear Information System (INIS)

    Zang, Weilin; Gunnars, Jens; Dong, Pingsha; Hong, Jeong K.

    2009-06-01

    The objective of this work is to identify and evaluate improvements for the residual stress modelling procedure currently used in Sweden. There is a growing demand to eliminate any unnecessary conservatism involved in residual stress assumptions. The study was focused on the development and validation of an improved weld residual stress modelling procedure, by taking advantage of the recent advances in residual stress modelling and stress measurement techniques. The major changes applied in the new weld residual stress modelling procedure are: - Improved procedure for heat source calibration based on use of analytical solutions. - Use of an isotropic hardening model where mixed hardening data is not available. - Use of an annealing model for improved simulation of strain relaxation in re-heated material. The new modelling procedure is demonstrated to capture the main characteristics of the through thickness stress distributions by validation to experimental measurements. Three austenitic stainless steel butt-welds cases are analysed, covering a large range of pipe geometries. From the cases it is evident that there can be large differences between the residual stresses predicted using the new procedure, and the earlier procedure or handbook recommendations. Previously recommended profiles could give misleading fracture assessment results. The stress profiles according to the new procedure agree well with the measured data. If data is available then a mixed hardening model should be used

  16. Procedural City Layout Generation Based on Urban Land Use Models

    NARCIS (Netherlands)

    Groenewegen, S.A.; Smelik, R.M.; Kraker, J.K. de; Bidarra, R.

    2009-01-01

    Training and simulation applications in virtual worlds require significant amounts of urban environments. Procedural generation is an efficient way to create such models. Existing approaches for procedural modelling of cities aim at facilitating the work of urban planners and artists, but either

  17. Generic Graph Grammar: A Simple Grammar for Generic Procedural Modelling

    DEFF Research Database (Denmark)

    Christiansen, Asger Nyman; Bærentzen, Jakob Andreas

    2012-01-01

    Methods for procedural modelling tend to be designed either for organic objects, which are described well by skeletal structures, or for man-made objects, which are described well by surface primitives. Procedural methods, which allow for modelling of both kinds of objects, are few and usually of...

  18. Procedures for Geometric Data Reduction in Solid Log Modelling

    Science.gov (United States)

    Luis G. Occeña; Wenzhen Chen; Daniel L. Schmoldt

    1995-01-01

    One of the difficulties in solid log modelling is working with huge data sets, such as those that come from computed axial tomographic imaging. Algorithmic procedures are described in this paper that have successfully reduced data without sacrificing modelling integrity.

  19. Single visit approach for management of cervical intraepithelial neoplasia by visual inspection & loop electrosurgical excision procedure

    Science.gov (United States)

    Singla, Shilpa; Mathur, Sandeep; Kriplani, Alka; Agarwal, Nutan; Garg, Pradeep; Bhatla, Neerja

    2012-01-01

    Background & objectives: Developing a feasible and sustainable model of cervical cancer screening in developing countries continues to be a challenge because of lack of facilities and awareness in the population and poor compliance with screening and treatment. This study was aimed to evaluate a single visit approach (SVA) for the management of cervical intraepithelial neoplasia (CIN) using visual inspection with acetic acid (VIA) and Lugol's iodine (VILI) along with loop electrosurgical excision procedure (LEEP) in women attending Gynaecology OPD in a tertiary care hospital in north India. Methods: In this hospital-based study, 450 women receiving opportunistic screening by conventional Pap cytology were also screened by VIA and VILI. VIA/VILI positive cases underwent same-day colposcopy and biopsy of all lesions. If the modified Reid score was >3, the patient underwent LEEP at the same visit. Results: Of the 450 women screened, 86 (19.1%) and 92 (20.5%) women were VIA and VILI positive, respectively. Detection rates of VIA, VILI and cytology findings at ASCUS threshold were 33.3, 35.5 and 24.4 per 1000, women, respectively to detect a lesion >CIN1. For detection of CIN2+ lesion, detection rates of VIA, VILI and cytology were 20, 22.2 and 22.2 per 1000 women, respectively. Sixteen patients with Reid score >3 underwent the See-and-treat protocol. The overtreatment rate was 12.5 per cent and the efficacy of LEEP was 81.3 per cent. There were no major complications. Interpretation & conclusions: The sensitivity of VIA/VILI was comparable to cytology. A single visit approach using visual screening methods at community level by trained paramedical personnel followed by a combination of ablative and excisional therapy can help to decrease the incidence of cervical neoplasia. PMID:22771589

  20. Power mos devices: structures and modelling procedures

    Energy Technology Data Exchange (ETDEWEB)

    Rossel, P.; Charitat, G.; Tranduc, H.; Morancho, F.; Moncoqut

    1997-05-01

    In this survey, the historical evolution of power MOS transistor structures is presented and currently used devices are described. General considerations on current and voltage capabilities are discussed and configurations of popular structures are given. A synthesis of different modelling approaches proposed last three years is then presented, including analytical solutions, for basic electrical parameters such as threshold voltage, on-resistance, saturation and quasi-saturation effects, temperature influence and voltage handling capability. The numerical solutions of basic semiconductor devices is then briefly reviewed along with some typical problems which can be solved this way. A compact circuit modelling method is finally explained with emphasis on dynamic behavior modelling

  1. Procedural meta-models for architectural design praxis

    Directory of Open Access Journals (Sweden)

    Gian Luca Brunetti

    2013-05-01

    Full Text Available This article discusses a procedure for the exploration of options in preliminary design. The procedure is based on the application of morphing procedures, which are typical of animation software, to building parametric analyses. The procedure is based on partially overlapping sequences of evaluations targeted on dynamic ad-hoc test-models and is aimed at the creation of data fields for the representation of the performance consequences of competing design sceneries. This representation is necessarily multidimensional and is based on parallel coordinates plots. The implementation of a specific test procedure of the kind described above is also discussed. The procedure has been supported by the use of contemporary analytical and representational systems and tools; namely, ESP-r, Radiance, Ggobi, and an extensible tool for the dynamic morphing of models through user-specified criteria, named OPTS, by the author.

  2. Procedural complications of endovascular treatment in patients with aneurysmal subarachnoid haemorrhage treated at a single centre.

    Science.gov (United States)

    Alanen, Mikko; Pyysalo, Liisa; Jalava, Iiro; Snicker, Oona; Pienimäki, Juha-Pekka; Öhman, Juha; Ronkainen, Antti

    2018-03-01

    We present a single-centre experience of procedural complications suffered by patients undergoing endovascular treatment for a ruptured saccular intracranial aneurysm at Tampere University Hospital, Finland, between 2000 and 2014. From 2000 to 2014, we treated 1,253 patients with aneurysmal subarachnoid haemorrhage, 491 of whom received endovascular treatment. Clinical data were collected retrospectively from the hospital's aneurysm database. A procedural complication was defined as having occurred whenever there was a documented new event in the patient's medical records or a note of a technical complication written by an interventionist after endovascular treatment. Procedural complications could be with or without clinical symptoms. Nearly 40% (491/1253) of the patients were treated with the endovascular method. Procedural complications occurred in 11.4% (56/491) of cases. The morbidity rate was 4.5% (22/491) and the mortality rate was 0.2% (1/491). Of the 56 complications, ischaemic complications occurred in 52% (29/56), haemorrhagic complications occurred in 27% (15/56) and technical complications occurred in 21% (12/56) of cases. In 61% (34/56) of the cases, the procedural complication did not cause any clinical symptoms. The total risk for procedural complications leading to postoperative disability or death at our institute was 4.7%. The complication frequency is in accordance with previous reports. Endovascular treatment of ruptured intracranial aneurysms is a safe treatment method when patient selection is carefully performed.

  3. Test procedures and instructions for single shell tank saltcake cesium removal with crystalline silicotitanate

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, J.B.

    1997-01-07

    This document provides specific test procedures and instructions to implement the test plan for the preparation and conduct of a cesium removal test, using Hanford Single Shell Tank Saltcake from tanks 24 t -BY- I 10, 24 1 -U- 108, 24 1 -U- 109, 24 1 -A- I 0 1, and 24 t - S-102, in a bench-scale column. The cesium sorbent to be tested is crystalline siticotitanate. The test plan for which this provides instructions is WHC-SD-RE-TP-024, Hanford Single Shell Tank Saltcake Cesium Removal Test Plan.

  4. Procedure simplification: the role of single-use instruments in total knee arthroplasty.

    Science.gov (United States)

    Bhadra, Arup K; Kwiecien, Grzegorz J; Harwin, Steven F; Johnson, Aaron J; Mont, Michael A; Malkani, Arthur L

    2012-12-01

    In orthopaedic surgery, surgical site contamination leading to periprosthetic infections is a major concern with important morbidity, financial and emotional burden. Single-use instruments developed for total knee arthroplasties are intended to simplify the surgical procedure, decrease the number of surgical trays that require sterilization and reprocessing, decrease the incidence of possible contamination through breaks in surgical wraps, and improve operating room efficiency. As the demand for total knee arthroplasty continues to rise, a greater burden on the healthcare system may be created. The use of single-use instruments, cutting guides, and trials will play an increasing role in total knee arthroplasty through improved operating room efficiency.

  5. Assessing Model Characterization of Single Source ...

    Science.gov (United States)

    Aircraft measurements made downwind from specific coal fired power plants during the 2013 Southeast Nexus field campaign provide a unique opportunity to evaluate single source photochemical model predictions of both O3 and secondary PM2.5 species. The model did well at predicting downwind plume placement. The model shows similar patterns of an increasing fraction of PM2.5 sulfate ion to the sum of SO2 and PM2.5 sulfate ion by distance from the source compared with ambient based estimates. The model was less consistent in capturing downwind ambient based trends in conversion of NOX to NOY from these sources. Source sensitivity approaches capture near-source O3 titration by fresh NO emissions, in particular subgrid plume treatment. However, capturing this near-source chemical feature did not translate into better downwind peak estimates of single source O3 impacts. The model estimated O3 production from these sources but often was lower than ambient based source production. The downwind transect ambient measurements, in particular secondary PM2.5 and O3, have some level of contribution from other sources which makes direct comparison with model source contribution challenging. Model source attribution results suggest contribution to secondary pollutants from multiple sources even where primary pollutants indicate the presence of a single source. The National Exposure Research Laboratory (NERL) Computational Exposure Division (CED) develops and evaluates data, deci

  6. Graphical models for inferring single molecule dynamics

    Directory of Open Access Journals (Sweden)

    Gonzalez Ruben L

    2010-10-01

    Full Text Available Abstract Background The recent explosion of experimental techniques in single molecule biophysics has generated a variety of novel time series data requiring equally novel computational tools for analysis and inference. This article describes in general terms how graphical modeling may be used to learn from biophysical time series data using the variational Bayesian expectation maximization algorithm (VBEM. The discussion is illustrated by the example of single-molecule fluorescence resonance energy transfer (smFRET versus time data, where the smFRET time series is modeled as a hidden Markov model (HMM with Gaussian observables. A detailed description of smFRET is provided as well. Results The VBEM algorithm returns the model’s evidence and an approximating posterior parameter distribution given the data. The former provides a metric for model selection via maximum evidence (ME, and the latter a description of the model’s parameters learned from the data. ME/VBEM provide several advantages over the more commonly used approach of maximum likelihood (ML optimized by the expectation maximization (EM algorithm, the most important being a natural form of model selection and a well-posed (non-divergent optimization problem. Conclusions The results demonstrate the utility of graphical modeling for inference of dynamic processes in single molecule biophysics.

  7. The Ross Procedure in Pediatric Patients: A 20-Year Experience of Ross Procedure in a Single Institution.

    Science.gov (United States)

    Yoon, Dong Woog; Yang, Ji-Hyuk; Jun, Tae-Gook; Park, Pyo Won

    2017-08-01

    The Ross/Ross-Konno procedure is considered a good option for irreparable aortic valve disease in pediatric patients because of its hemodynamic performance and potential for growth of the pulmonary autograft. This study is a review of the long-term results of our 20-year experience with the Ross and Ross-Konno operations in a single institution. Between June 1995 and January 2016, 16 consecutive patients (mean age, 6.0±5.9 years; range, 16 days to 17.4 years) underwent either a Ross operation (n=9) or a Ross-Konno operation (n=7). The study included 12 males and 4 females, with a median follow-up period of 47 months (range, 6 to 256 months). There were no cases of in-hospital or late mortality. Six reoperations were performed in 5 patients. Four patients underwent right ventricular-pulmonary artery (RV-PA) conduit replacement. Two patients underwent concomitant replacement of the pulmonary autograft and RV-PA conduit 10 years and 8 years after the Ross operation, respectively. The rate of freedom from adverse outcomes of the pulmonary autograft was 88% and 70% at 5 and 10 years, respectively. The rate of freedom from valve-related reoperations was 79% and 63% at 5 and 10 years, respectively. Pulmonary autografts demonstrated good durability with low mortality. The Ross/Ross-Konno procedure is a good option that can be performed safely in pediatric patients with aortic valve disease, even in a small-volume center.

  8. Inference-based procedural modeling of solids

    KAUST Repository

    Biggers, Keith

    2011-11-01

    As virtual environments become larger and more complex, there is an increasing need for more automated construction algorithms to support the development process. We present an approach for modeling solids by combining prior examples with a simple sketch. Our algorithm uses an inference-based approach to incrementally fit patches together in a consistent fashion to define the boundary of an object. This algorithm samples and extracts surface patches from input models, and develops a Petri net structure that describes the relationship between patches along an imposed parameterization. Then, given a new parameterized line or curve, we use the Petri net to logically fit patches together in a manner consistent with the input model. This allows us to easily construct objects of varying sizes and configurations using arbitrary articulation, repetition, and interchanging of parts. The result of our process is a solid model representation of the constructed object that can be integrated into a simulation-based environment. © 2011 Elsevier Ltd. All rights reserved.

  9. On the general procedure for modelling complex ecological systems

    International Nuclear Information System (INIS)

    He Shanyu.

    1987-12-01

    In this paper, the principle of a general procedure for modelling complex ecological systems, i.e. the Adaptive Superposition Procedure (ASP) is shortly stated. The result of application of ASP in a national project for ecological regionalization is also described. (author). 3 refs

  10. A skin abscess model for teaching incision and drainage procedures.

    Science.gov (United States)

    Fitch, Michael T; Manthey, David E; McGinnis, Henderson D; Nicks, Bret A; Pariyadath, Manoj

    2008-07-03

    Skin and soft tissue infections are increasingly prevalent clinical problems, and it is important for health care practitioners to be well trained in how to treat skin abscesses. A realistic model of abscess incision and drainage will allow trainees to learn and practice this basic physician procedure. We developed a realistic model of skin abscess formation to demonstrate the technique of incision and drainage for educational purposes. The creation of this model is described in detail in this report. This model has been successfully used to develop and disseminate a multimedia video production for teaching this medical procedure. Clinical faculty and resident physicians find this model to be a realistic method for demonstrating abscess incision and drainage. This manuscript provides a detailed description of our model of abscess incision and drainage for medical education. Clinical educators can incorporate this model into skills labs or demonstrations for teaching this basic procedure.

  11. Validation of the PESTLA model: Definitions, objectives and procedure

    NARCIS (Netherlands)

    Boekhold AE; van den Bosch H; Boesten JJTI; Leistra M; Swartjes FA; van der Linden AMA

    1993-01-01

    The simulation model PESTLA was developed to produce estimates of accumulation and leaching of pesticides in soil to facilitate classification of pesticides in the Dutch registration procedure. Before PESTLA can be used for quantitative assessment of expected pesticide concentrations in

  12. Design Transformations for Rule-based Procedural Modeling

    KAUST Repository

    Lienhard, Stefan

    2017-05-24

    We introduce design transformations for rule-based procedural models, e.g., for buildings and plants. Given two or more procedural designs, each specified by a grammar, a design transformation combines elements of the existing designs to generate new designs. We introduce two technical components to enable design transformations. First, we extend the concept of discrete rule switching to rule merging, leading to a very large shape space for combining procedural models. Second, we propose an algorithm to jointly derive two or more grammars, called grammar co-derivation. We demonstrate two applications of our work: we show that our framework leads to a larger variety of models than previous work, and we show fine-grained transformation sequences between two procedural models.

  13. Infection Rate after Cranial Neurosurgical Procedures: A Prospective Single-Center Study.

    Science.gov (United States)

    Strahm, Carol; Albrich, Werner C; Zdravkovic, Vilijam; Schöbi, Barbara; Hildebrandt, Gerhard; Schlegel, Matthias

    2018-03-01

    To determine infection rate (IR) and to identify modifiable risk factors (RF) in cranial neurosurgery in a neurosurgical department for tertiary referral as part of an infection control surveillance to reduce surgical site infections (SSI). A prospective SSI incidence cohort study from February 2013 to January 2014 was performed in a tertiary-care neurosurgical teaching hospital and referral center. All consecutive adults undergoing any cranial neurosurgical procedure were included. Data were collected by a trained member of the infection control staff during the twice-weekly visits of the hospitalized patients. Follow-up was 30 days (procedures without implant) and 1 year (procedures involving permanent implants). SSI was diagnosed according to criteria of CDC. A total of 317 patients undergoing 333 index procedures were included. The median age was 61 years (range, 17-91 years) and 46% were female. Survival in patients with completed follow-up was 76% (196/258). Overall, IR was 7.2% (24/333 index procedures); in 96% (23/24), a neurosurgical implant was involved. The IR of extraventricular drainage (EVD) was 12.5% (13.1/1000 EVD days). The main causative pathogens were Staphylococcus aureus followed by coagulase-negative staphylococci and Propionibacterium acnes. Independent RF for neurosurgical SSI were EVD as part of the index operation and body mass index >25 kg/m 2 . IR was in accordance with recent prospective single-center studies (reported IR between 1.6% and 9%). EVD placement was identified as the strongest modifiable RF for SSI in cranial neurosurgical procedures. The need for standard infection control procedures for the insertion and maintenance of EVDs to avoid their contamination is reinforced. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Procedural guide for modelling and analyzing the flight characteristics of a helicopter design using Flightlab

    OpenAIRE

    McVaney, Gary P.

    1993-01-01

    Approved for public release; distribution is unlimited. This thesis presents one method for modelling and analyzing a helicopter design using Flightlab. Flightlab is a computer program that provides for engineering design, analysis and simulation of aircraft using non-linear dynamic modeling techniques. The procedure to model a single main rotor helicopter is outlined using the sample helicopter design in the book 'Helicopter Performance, Stability, and Control' by Ray Prouty. The analysis...

  15. Shape Synthesis from Sketches via Procedural Models and Convolutional Networks.

    Science.gov (United States)

    Huang, Haibin; Kalogerakis, Evangelos; Yumer, Ersin; Mech, Radomir

    2017-08-01

    Procedural modeling techniques can produce high quality visual content through complex rule sets. However, controlling the outputs of these techniques for design purposes is often notoriously difficult for users due to the large number of parameters involved in these rule sets and also their non-linear relationship to the resulting content. To circumvent this problem, we present a sketch-based approach to procedural modeling. Given an approximate and abstract hand-drawn 2D sketch provided by a user, our algorithm automatically computes a set of procedural model parameters, which in turn yield multiple, detailed output shapes that resemble the user's input sketch. The user can then select an output shape, or further modify the sketch to explore alternative ones. At the heart of our approach is a deep Convolutional Neural Network (CNN) that is trained to map sketches to procedural model parameters. The network is trained by large amounts of automatically generated synthetic line drawings. By using an intuitive medium, i.e., freehand sketching as input, users are set free from manually adjusting procedural model parameters, yet they are still able to create high quality content. We demonstrate the accuracy and efficacy of our method in a variety of procedural modeling scenarios including design of man-made and organic shapes.

  16. SYNTHESIS OF INFORMATION MODEL FOR ALTERNATIVE FUNCTIONAL DIAGNOSTICS PROCEDURE

    OpenAIRE

    P. F. Shchapov; R. P. Miguschenko

    2014-01-01

    Probabilistic approaches in information theory and information theory of measurement, allowing to calculate and analyze the amount expected to models measuring conversions and encoding tasks random measurement signals were considered. A probabilistic model of diagnostic information model transformation and diagnostic procedures was developed. Conditions for obtaining the maximum amount of diagnostic information were found out.

  17. Minimal invasive single-site surgery in colorectal procedures: Current state of the art

    Directory of Open Access Journals (Sweden)

    Diana Michele

    2011-01-01

    Full Text Available Background: Minimally invasive single-site (MISS surgery has recently been applied to colorectal surgery. We aimed to assess the current state of the art and the adequacy of preliminary oncological results. Methods: We performed a systematic review of the literature using Pubmed, Medline, SCOPUS and Web of Science databases. Keywords used were "Single Port" or "Single-Incision" or "LaparoEndoscopic Single Site" or "SILS™" and "Colon" or "Colorectal" and "Surgery". Results: Twenty-nine articles on colorectal MISS surgery have been published from July 2008 to July 2010, presenting data on 149 patients. One study reported analgesic requirement. The final incision length ranged from 2.5 to 8 cm. Only two studies reported fascial incision length. There were two port site hernias in a series of 13 patients (15.38%. Two "fully laparoscopic" MISS procedures with preparation and achievement of the anastomosis completely intracorporeally are reported. Future site of ileostomy was used as the sole access for the procedures in three studies. Lymph node harvesting, resection margins and length of specimen were sufficient in oncological cases. Conclusions: MISS colorectal surgery is a challenging procedure that seems to be safe and feasible, but the existing clinical evidence is limited. In selected cases, and especially when an ileostomy is planned, colorectal surgery may be an ideal indication for MISS surgery leading to a no-scar surgery. Despite preliminary oncological results showing the feasibility of MISS surgery, we want to stress the need to standardize the technique and carefully evaluate its application in oncosurgery under ethical committee control.

  18. Single-stage Modified Duhamel procedure for Hirschsprung′s disease : Our experience

    Directory of Open Access Journals (Sweden)

    Paras R Kothari

    2012-01-01

    Full Text Available Introduction: Primary single-stage pull-through for Hirschsprung′s disease (HD has been reported to give comparable surgical outcomes to staged operations with less morbidity. Herein, we present our experience with single-stage Modified Duhamel procedure for management of HD. Patients and Methods: This was a review of 48 cases of HD who underwent single-stage Modified Duhamel procedure without a protective colostomy. Results: The age at surgery ranged from 6 months to 10 years (median - 9 months, mean - 2.3 years. The average weight of the child was 7.2 kg (range, 4.9-22 kg. 38 (79.2% patients had classical rectosigmoid HD, the rest being long segment HD (the proximal most level being the splenic flexure. The average duration of surgery was 175 minutes (range, 130-245 minutes. The average blood loss was 45 ml. The average hospital stay was 7.2 days (range: 6-10 days. The major postoperative complications (n=3 included postoperative adhesive intestinal obstruction, anastomotic leak and persistent constipation due to residual aganglionosis. Each required a re-exploration. Minor complications included surgical site infection (n=3 and post-operative enterocolitis (n=3, which were managed conservatively. Six patients had constipation for a limited period post-operatively. All patients have a satisfactory functional outcome and normal development and growth. Conclusions: For HD, we recommend that single-stage Modified Duhamel procedure should be the preferred approach in view of its low morbidity, satisfactory functional outcome and avoidance of stoma, multiple surgeries and economic benefit in view of decreased hospital stay.

  19. First steps towards fuel cells testing harmonisation: Procedures and parameters for single cell performance evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Lunghi, P. [Department of Industrial Engineering, University of Perugia, Via Duranti 93, Perugia (Italy); Ubertini, S. [Department of Mechanical Engineering, University of Rome ' ' Tor Vergata' ' , Via di Torvergata, 110, Rome (Italy)

    2004-01-01

    The great interest in Fuel Cell Systems, combined with the innovation of the device itself, has led to a huge developmental effort to make the steps necessary for future FC plant commissioning. The clearest and most effective way to evaluate the performance of a fuel cell is to measure it directly and, since few fuel cell test rigs are available at the moment, standard experimental procedures have not been realized so far. Our research group is currently performing single cell testing at the University of Perugia fuel cell laboratory and particular emphasis has been put on the definition of procedures and the testing of parameterisation. The work team strongly believes that this is the key to effective system testing and reliable performance evaluation. In this work, the test parameterisation developed by the team, and the resulting advanced control procedure used for a single MCFC experimental characterization are presented. Efforts have been dedicated to obtain some relevant non-dimensional parameters to allow an easy understanding of the results and quick comparisons with other tests under different operating conditions, or with results obtained on different cells eventually tested in different laboratories. The authors strongly emphasise this topic to avoid the data that developers and research institutions collect being of no practical use due to a lack of shared rules. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

  20. Single-piece maintenance procedures for the TITAN reversed-field pinch reactor

    International Nuclear Information System (INIS)

    Grotz, S.P.; Creedon, R.L.; Cooke, P.I.H.; Duggan, W.P.; Krakowski, R.A.; Najmabadi, F.; Wong, C.P.C.

    1987-01-01

    The TITAN reactor is a compact (major radius of 3.9 m and minor plasma radius of 0.6 m), high neutron wall loading (--18MW/m 2 ) fusion energy system based on the reversed-field pinch (RFP) concept. The TITAN-I fusion power core (FPC) is a lithium, self-cooled design with vanadium alloy (V-3Ti-1Si) structural material. The compact design of the TITAN fusion power core (FPC) reduces the system to a few small and relatively low mass components, making toroidal segmentation of the FPC unnecessary. A single-piece maintenance procedure in which the replaceable first wall and blanket is removed as a single unit is, therefore, possible. The TITAN FPC design provides for top access to the reactor with vertical lifts used to remove the components. The number of remote handling procedures is few and the movements are uncomplicated. The annual torus replacement requires that the reusable ohmic-heating coil set and hot-shield assembly be removed and temporarily stored in a hot cell. The used first wall and blanket assembly is drained and disconnected from the coolant supply system, then lifted to a processing room where it is cooled and prepared for Class-C waste burial. The new, pre-tested first wall and blanket assembly is then lowered into position and the removal procedure is reversed to complete the replacement process

  1. Replica Analysis for Portfolio Optimization with Single-Factor Model

    Science.gov (United States)

    Shinzato, Takashi

    2017-06-01

    In this paper, we use replica analysis to investigate the influence of correlation among the return rates of assets on the solution of the portfolio optimization problem. We consider the behavior of an optimal solution for the case where the return rate is described with a single-factor model and compare the findings obtained from our proposed methods with correlated return rates with those obtained with independent return rates. We then analytically assess the increase in the investment risk when correlation is included. Furthermore, we also compare our approach with analytical procedures for minimizing the investment risk from operations research.

  2. Surgical reconstruction of pressure ulcer defects: a single- or two-stage procedure?

    LENUS (Irish Health Repository)

    Laing, Tereze A

    2012-02-01

    BACKGROUND: The surgical management of pressure ulcers traditionally involved staged procedures, with initial debridement of necrotic or infected material followed by reconstruction at a later date when the wound was deemed viable and free of gross infection. However, over the past decade, it has been suggested that a single-stage procedure, combining initial debridement and definitive reconstruction, may provide advantages over staged surgery. We present our experience with the staged approach and review the current evidence for both methods. SUBJECTS AND SETTINGS: : We reviewed medical records of all patients referred to our service for pressure ulcer management between October 2001 and October 2007. The National Rehabilitation Hospital is the national center in Ireland for primary rehabilitation of adults and children suffering from spinal and brain injury, serving patients locally and from around the country. METHODS: All subjects who were managed surgically underwent a 2-stage procedure, with initial debridement and subsequent reconstruction. The main outcome measures were length of hospital stay, postoperative morbidity and mortality, and time to complete ulcer healing. RESULTS: Forty-one of 108 patients with 58 pressure ulcers were managed surgically. All patients underwent initial surgical debridement and 20 patients underwent subsequent pressure ulcer reconstruction. Postreconstructive complications occurred in 5 patients (20%). The mean time to complete ulcer healing was 17.4 weeks. Partial flap necrosis occurred in 3 patients, but there were no episodes of flap failure. CONCLUSIONS: We achieved favorable results with a 2-stage reconstruction technique and suggest that the paucity of evidence related to single-stage procedures does not support a change in surgical management.

  3. Using an Instructional Design Model to Teach Medical Procedures.

    Science.gov (United States)

    Cheung, Lawrence

    Educators are often tasked with developing courses and curricula that teach learners how to perform medical procedures. This instruction must provide an optimal, uniform learning experience for all learners. If not well designed, this instruction risks being unstructured, informal, variable amongst learners, or incomplete. This article shows how an instructional design model can help craft courses and curricula to optimize instruction in performing medical procedures. Educators can use this as a guide to developing their own course instruction.

  4. Procedures for parameter estimates of computational models for localized failure

    NARCIS (Netherlands)

    Iacono, C.

    2007-01-01

    In the last years, many computational models have been developed for tensile fracture in concrete. However, their reliability is related to the correct estimate of the model parameters, not all directly measurable during laboratory tests. Hence, the development of inverse procedures is needed, that

  5. The possibility of a fully automated procedure for radiosynthesis of fluorine-18-labeled fluoromisonidazole using a simplified single, neutral alumina column purification procedure

    International Nuclear Information System (INIS)

    Nandy, Saikat; Rajan, M.G.R.; Korde, A.; Krishnamurthy, N.V.

    2010-01-01

    A novel fully automated radiosynthesis procedure for [ 18 F]Fluoromisonidazole using a simple alumina cartridge-column for purification instead of conventionally used semi-preparative HPLC was developed. [ 18 F]FMISO was prepared via a one-pot, two-step synthesis procedure using a modified nuclear interface synthesis module. Nucleophilic fluorination of the precursor molecule 1-(2'-nitro-1'-imidazolyl) -2-O-tetrahydropyranyl-3-O-toluenesulphonylpropanediol (NITTP) with no-carrier added [ 18 F]fluoride followed by hydrolysis of the protecting group with 1 M HCl. Purification was carried out using a single neutral alumina cartridge-column instead of semi-preparative HPLC. The maximum overall radiochemical yield obtained was 37.49±1.68% with 10 mg NITTP (n=3, without any decay correction) and the total synthesis time was 40±1 min. The radiochemical purity was greater than 95% and the product was devoid of other chemical impurities including residual aluminum and acetonitrile. The biodistribution study in fibrosarcoma tumor model showed maximum uptake in tumor, 2 h post injection. Finally, PET/CT imaging studies in normal healthy rabbit, showed clear uptake in the organs involved in the metabolic process of MISO. No bone uptake was observed excluding the presence of free [ 18 F]fluoride. The reported method can be easily adapted in any commercial FDG synthesis module.

  6. Candidate reagents and procedures for the dissolution of Hanford Site single-shell tank sludges

    International Nuclear Information System (INIS)

    Schulz, W.W.; Kupfer, M.J.

    1991-10-01

    At least some of the waste in the 149 single-shell tanks (SST) at the US Department of Energy (DOE) Hanford Site will be retrieved, treated, and disposed of. Although the importance of devising efficient and cost-effective sludge dissolution procedures has long been recognized, a concerted bench-scale effort to devise and test such procedures with actual solids representative of those in Hanford Site SSTs has not been performed. Reagents that might be used, either individually or serially, to dissolve sludges include HNO 3 , HNO 3 -oxalic acid, and HNO 3 -HF. This report consolidates and updates perspectives and recommendations concerning reagents and procedures for dissolving Hanford Site SST and selected double-shell tank (DST) sludges. The principal objectives of this report are as follows: (1) Compile and review existing experimental data on dissolution of actual Hanford Site SST and DST sludges. (2) Further inform Hanford Site engineers and scientists concerning the utility of combinations of thermally unstable complexants (TUCS) reagents and various reducing agents for dissolving SST and DST sludges. (This latter technology has recently been explored at the Argonne National Laboratory.) (3) Provide guidance in laying out a comprehensive experimental program to develop technology for dissolving all types of Hanford Site SST and DST sludges. 6 refs., 1 fig., 4 tabs

  7. Model checking as an aid to procedure design

    International Nuclear Information System (INIS)

    Zhang, Wenhu

    2001-01-01

    The OECD Halden Reactor Project has been actively working on computer assisted operating procedures for many years. The objective of the research has been to provide computerised assistance for procedure design, verification and validation, implementation and maintenance. For the verification purpose, the application of formal methods has been considered in several reports. The recent formal verification activity conducted at the Halden Project is based on using model checking to the verification of procedures. This report presents verification approaches based on different model checking techniques and tools for the formalization and verification of operating procedures. Possible problems and relative merits of the different approaches are discussed. A case study of one of the approaches is presented to show the practical application of formal verification. Application of formal verification in the traditional procedure design process can reduce the human resources involved in reviews and simulations, and hence reduce the cost of verification and validation. A discussion of the integration of the formal verification with the traditional procedure design process is given at the end of this report. (Author)

  8. Surgical treatment of chronic pancreatitis using Frey's procedure: a Brazilian 16-year single-centre experience.

    Science.gov (United States)

    Gestic, Martinho Antonio; Callejas-Neto, Francisco; Chaim, Elinton Adami; Utrini, Murillo Pimentel; Cazzo, Everton; Pareja, Jose Carlos

    2011-04-01

    Surgical treatment of chronic pancreatitis is indicated for intractable pain. Frey's procedure is an accepted treatment for this disease. The aim of the present study was to describe a single-centre experience in the treatment of chronic pancreatitis using Frey's procedure. A retrospective analysis of 73 patients who underwent a Frey's procedure between 1991 to 2007 and had at least 1 year of follow-up. Demographics, indication for surgery, peri-operative complications and late outcomes were analysed. The median age was 39.9 years. Seventy out of the 73 (95.8%) patients were male. The median pre-operative body mass index (BMI) was 19.1 kg/m(2). All patients had abdominal pain, 34 (46.6%) of them daily and 13 (17.8%) weekly, with moderate or severe intensity in 98.6% (n= 72). The aetiology was secondary to alcohol in 70 patients (95.9%), with a median consumption of 278 g per day. The surgical morbidity rate was 28.7%; there were no deaths. Median post-operative follow-up was 77.0 months; 64 patients (91.4%) had complete pain relief and post-operative BMI was 22.4 kg/m(2) (P<0.001). All patients with pre-operative endocrine and exocrine insufficiencies showed no reversal of the situation. New onset insufficiencies appeared late. Frey's procedure was a safe and effective therapeutic option for the surgical treatment of patients with intractable pain caused by chronic pancreatitis. © 2011 International Hepato-Pancreato-Biliary Association.

  9. Model and Variable Selection Procedures for Semiparametric Time Series Regression

    Directory of Open Access Journals (Sweden)

    Risa Kato

    2009-01-01

    Full Text Available Semiparametric regression models are very useful for time series analysis. They facilitate the detection of features resulting from external interventions. The complexity of semiparametric models poses new challenges for issues of nonparametric and parametric inference and model selection that frequently arise from time series data analysis. In this paper, we propose penalized least squares estimators which can simultaneously select significant variables and estimate unknown parameters. An innovative class of variable selection procedure is proposed to select significant variables and basis functions in a semiparametric model. The asymptotic normality of the resulting estimators is established. Information criteria for model selection are also proposed. We illustrate the effectiveness of the proposed procedures with numerical simulations.

  10. Single-session versus staged procedures for elective multivessel percutaneous coronary intervention.

    Science.gov (United States)

    Toyota, Toshiaki; Morimoto, Takeshi; Shiomi, Hiroki; Yamaji, Kyohei; Ando, Kenji; Ono, Koh; Shizuta, Satoshi; Saito, Naritatsu; Kato, Takao; Kaji, Shuichiro; Furukawa, Yutaka; Nakagawa, Yoshihisa; Kadota, Kazushige; Horie, Minoru; Kimura, Takeshi

    2017-11-16

    To clarify the effect of single-session multivessel percutaneous coronary intervention (PCI) strategy relative to the staged multivessel strategy on clinical outcomes in patients with stable coronary artery disease (CAD) or non-ST-elevation acute coronary syndrome. In the Coronary REvascularisation Demonstrating Outcome Study in Kyoto PCI/coronary artery bypass grafting registry cohort-2, there were 2018 patients who underwent elective multivessel PCI. Primary outcome measure was composite of all-cause death, myocardial infarction and stroke at 5-year follow-up. Single-session multivessel PCI and staged multivessel PCI were performed in 707 patients (35.0%) and 1311 patients (65.0%), respectively. The cumulative 5-year incidence of and adjusted risk for the primary outcome measure were not significantly different between the single-session and staged groups (26.7% vs 23.0%, p=0.45; HR 0.91, 95% CI 0.72 to 1.16, p=0.47). The 30-day incidence of all-cause death was significantly higher in the single-session group than in the staged group (1.1% vs 0.2%, p=0.009). However, the causes of death in 11 patients who died within 30 days were generally not related to the procedural complications, but related to the serious clinical status before PCI. For the subgroup analyses including age, gender, extent of CAD, severe chronic kidney disease and heart failure, there was no significant interaction between the subgroup factors and the effect of the single-session strategy relative to the staged strategy for the primary outcome measure. The single-session multivessel PCI strategy was associated with at least comparable 5-year clinical outcomes compared with the staged multivessel PCI, although the prevalence of the single-session strategy was low in the present study. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  11. Procedural Skills Education – Colonoscopy as a Model

    Directory of Open Access Journals (Sweden)

    Maitreyi Raman

    2008-01-01

    Full Text Available Traditionally, surgical and procedural apprenticeship has been an assumed activity of students, without a formal educational context. With increasing barriers to patient and operating room access such as shorter work week hours for residents, and operating room and endoscopy time at a premium, alternate strategies to maximizing procedural skill development are being considered. Recently, the traditional surgical apprenticeship model has been challenged, with greater emphasis on the need for surgical and procedural skills training to be more transparent and for alternatives to patient-based training to be considered. Colonoscopy performance is a complex psychomotor skill requiring practioners to integrate multiple sensory inputs, and involves higher cortical centres for optimal performance. Colonoscopy skills involve mastery in the cognitive, technical and process domains. In the present review, we propose a model for teaching colonoscopy to the novice trainee based on educational theory.

  12. Communication and Procedural Models of the E-Commerce Systems

    Directory of Open Access Journals (Sweden)

    Petr SUCHÁNEK

    2009-06-01

    Full Text Available E-commerce systems became a standard interface between sellers (or suppliers and customers. One of basic condition of an e-commerce system to be efficient is correct definitions and describes of the all internal and external processes. All is targeted the customers´ needs and requirements. The optimal and most exact way how to obtain and find optimal solution of e-commerce system and its processes structure in companies is the modeling and simulation. In this article author shows basic model of communication between customers and sellers in connection with the customer feedback and procedural models of e-commerce systems in terms of e-shops. Procedural model was made with the aid of definition of SOA.

  13. A verification procedure for MSC/NASTRAN Finite Element Models

    Science.gov (United States)

    Stockwell, Alan E.

    1995-01-01

    Finite Element Models (FEM's) are used in the design and analysis of aircraft to mathematically describe the airframe structure for such diverse tasks as flutter analysis and actively controlled landing gear design. FEM's are used to model the entire airplane as well as airframe components. The purpose of this document is to describe recommended methods for verifying the quality of the FEM's and to specify a step-by-step procedure for implementing the methods.

  14. A SINGLE-COLUMN PROCEDURE ON BOND ELUT CERTIFY FOR SYSTEMATIC TOXICOLOGICAL ANALYSIS OF DRUGS IN PLASMA AND URINE

    NARCIS (Netherlands)

    CHEN, XH; WIJSBEEK, J; FRANKE, JP; DEZEEUW, RA

    A single-column solid-phase extraction procedure was developed for the screening of acidic, neutral, and basic drugs from plasma. The recoveries of all 25 tested drugs exceeded 82%. After the plasma had been diluted with phosphate buffer (pH 6.0), the drugs were extracted using a single Bond Elut

  15. Single stage bilateral uniportal videothoracoscopic sympathicotomy for hyperhidrosis: can it be managed as an outpatient procedure?

    Directory of Open Access Journals (Sweden)

    Ahmet Demirkaya

    2016-05-01

    Full Text Available Introduction : The videothoracoscopic approach is minimally invasive with benefits that include less postoperative pain and shorter hospital stay. It is also a safe procedure which can be performed on an outpatient basis. Aim: To determine whether videothoracoscopic sympathicotomy can be performed safely in most patients as an outpatient procedure. Material and methods: Between July 2005 and October 2015, a total of 92 patients underwent bilateral and single port thoracoscopic sympathicotomy in our department on an outpatient basis. The level of sympathicotomy was T2 in 2 (2.2% patients, T2 to T3 in 31 (33% patients, T2 to T4 in 46 (50% patients and T3 to T4 in 12 (13% patients. Demographic data, length of postoperative stay, substitution index (SI, admission rate (AR and readmission rate (RR, complications and patient satisfaction were reviewed retrospectively. Results: Two (2.2% patients suffered from chest pain, while 4 (4.3% patients complained about pain at the port site. Mean discharge time after surgery was 5.1 h (range: 4–6 h, mean duration of hospital stay was 0.15 days (0–3 days postoperatively and the mean operation time was 43.6 min (15–130 min. In 8 (8.6% patients, pneumothorax was detected on postoperative chest X-ray, while 5 (5.4% patients required chest tube drainage. Mild or moderate compensatory sweating developed in 32 (34.7% patients. No recurrence was observed, and the satisfaction rate was 96.7%. Substitution index and admission rate were 91.3% and 11% respectively, while RR was 0%. Conclusions : Bilateral video-assisted thoracoscopic sympathicotomy can be performed safely in most patients as an outpatient procedure.

  16. An innovative model for teaching and learning clinical procedures.

    Science.gov (United States)

    Kneebone, Roger; Kidd, Jane; Nestel, Debra; Asvall, Suzanne; Paraskeva, Paraskevas; Darzi, Ara

    2002-07-01

    Performing a clinical procedure requires the integration of technical clinical skills with effective communication skills. However, these skills are often taught separately. To explore the feasibility and benefits of a new conceptual model for integrated skills teaching. : Design A qualitative observation and interview-based study of undergraduate medical students. Medical students performed technical and communication skills in realistic clinical scenarios (urinary catherization and wound closure), using latex models connected to simulated patients (SPs). Procedures were observed, videorecorded and assessed by tutors from an adjoining room. Students received immediate feedback from tutors and SPs, before engaging in a process of individual feedback through private review of their videotapes. Group interviews explored the response of students, SPs and tutors. Data were analysed using standard qualitative techniques. Fifty-one undergraduate students were recruited from the Faculty of Medicine, Imperial College, London. The scenarios provided a realistic simulation of two common clinical situations and proved feasible in terms of time, facilities and resources within this institution. Students found the opportunity to integrate communication and technical skills valuable, challenging and an appropriate learning experience. Immediate feedback was especially highly valued. Some students found difficulty integrating technical and communications skills, but benefited from conducting two procedures in the same session. The integrated model was feasible and was perceived to be valuable. Benefits include the opportunity to integrate, within a safe environment, skills which are often taught separately. Promoting reflective practice may enable the successful transfer of these integrated skills to other procedures.

  17. Distributions and concentrations of thallium in Korean soils determined by single and sequential extraction procedures.

    Science.gov (United States)

    Lee, Jin-Ho; Kim, Dong-Jin; Ahn, Byung-Koo

    2015-06-01

    The objectives of this study were to investigate the distribution of thallium in soils collected near suspected areas such as cement plants, active and closed mines, and smelters and to examine the extraction of thallium in the soils using 19 single chemical and sequential chemical extraction procedures. Thallium concentrations in soils near cement plants were distributed between 1.20 and 12.91 mg kg(-1). However, soils near mines and smelters contained relatively low thallium concentrations ranging from 0.18 to 1.09 mg kg(-1). Thallium extractability with 19 single chemical extractants from selected soils near cement plants ranged from 0.10% to 8.20% of the total thallium concentration. In particular, 1.0 M NH4Cl, 1.0 M (NH4)2SO4, and 1.0 M CH3COONH4 extracted more thallium than other extractants. Sequential fractionation results of thallium from different soils such as industrially and artificially contaminated soils varied with the soil properties, especially soil pH and the duration of thallium contamination.

  18. Single Visit Apexification Procedure of a Traumatically Injured Tooth with a Novel Bioinductive Material (Biodentine)

    Science.gov (United States)

    Jingarwar, Mahesh Madhukar; Pathak, Anuradha

    2015-01-01

    ABSTRACT Aim of this article is to present a case wherein single visit apexification of a traumatically injured tooth was done with a bioactive material–Biodentine. An injury sustained between the ages of 6 and 14 can adversely affect pulpal health and interrupt root development. In these instances, apexification is generally the preferred treatment. A 10 years old male patient presented with coronal fracture of the left upper central incisor. Clinical and radiographic assessment showed negative pulpal sensibility and arrested apical root development. Artificial apical barrier induction with Biodentine followed by endodontic treatment and prosthetic rehabilitation was decided as the line of treatment. To conclude, this bioactive and biocompatible calcium-based cement can regenerate damaged dental tissues and represents a promising alternative to the conventional multivisit apexification technique. Clinical significance: Biodentine which is a biologically active cement can be an efficient alternative to the conventional apexification materials which were hitherto recommended. How to cite this article: Bajwa NK, Jingarwar MM, Pathak A. Single Visit Apexification Procedure of a Traumatically Injured Tooth with a Novel Bioinductive Material (Biodentine). Int J Clin Pediatr Dent 2015;8(1):58-61. PMID:26124583

  19. Structural cerebral abnormalities and neurodevelopmental status in single ventricle congenital heart disease before Fontan procedure.

    Science.gov (United States)

    Knirsch, Walter; Mayer, Kristina Nadine; Scheer, Ianina; Tuura, Ruth; Schranz, Dietmar; Hahn, Andreas; Wetterling, Kristina; Beck, Ingrid; Latal, Beatrice; Reich, Bettina

    2017-04-01

    Neonates with single ventricle congenital heart disease are at risk for structural cerebral abnormalities. Little is known about the further evolution of cerebral abnormalities until Fontan procedure. Between August 2012 and July 2015, we conducted a prospective cross-sectional two centre study using cerebral magnetic resonance imaging (MRI) and neuro-developmental outcome assessed by the Bayley-III. Forty-seven children (31 male) were evaluated at a mean age of 25.9 ± 3.4 months with hypoplastic left heart syndrome (25) or other single ventricle (22). Cerebral MRI was abnormal in 17 patients (36.2%) including liquor space enlargements (10), small grey (9) and minimal white (5) matter injuries. Eight of 17 individuals had combined lesions. Median (range) cognitive composite score (CCS) (100, 65-120) and motor composite score (MCS) (97, 55-124) were comparable to the reference data, while language composite score (LCS) (97, 68-124) was significantly lower ( P  = 0.040). Liquor space enlargement was associated with poorer performance on all Bayley-III subscores (CCS: P  = 0.02; LCS: P  = 0.002; MCS: P  = 0.013). The number of re-operations [odds ratio (OR) 2.2, 95% confidence interval (CI) 1.1-4.3] ( P  = 0.03) and re-interventions (OR 2.1, 95% CI 1.1-3.8) ( P  = 0.03) was associated with a higher rate of overall MRI abnormalities. Cerebral MRI abnormalities occur in more than one third of children with single ventricle, while the neuro-developmental status is less severely affected before Fontan procedure. Liquor space enlargement is the predominant MRI finding associated with poorer neuro-developmental status, warranting further studies to determine aetiology and further evolution until school-age. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  20. Resampling procedures to validate dendro-auxometric regression models

    Directory of Open Access Journals (Sweden)

    2009-03-01

    Full Text Available Regression analysis has a large use in several sectors of forest research. The validation of a dendro-auxometric model is a basic step in the building of the model itself. The more a model resists to attempts of demonstrating its groundlessness, the more its reliability increases. In the last decades many new theories, that quite utilizes the calculation speed of the calculators, have been formulated. Here we show the results obtained by the application of a bootsprap resampling procedure as a validation tool.

  1. Enhancing photogrammetric 3d city models with procedural modeling techniques for urban planning support

    International Nuclear Information System (INIS)

    Schubiger-Banz, S; Arisona, S M; Zhong, C

    2014-01-01

    This paper presents a workflow to increase the level of detail of reality-based 3D urban models. It combines the established workflows from photogrammetry and procedural modeling in order to exploit distinct advantages of both approaches. The combination has advantages over purely automatic acquisition in terms of visual quality, accuracy and model semantics. Compared to manual modeling, procedural techniques can be much more time effective while maintaining the qualitative properties of the modeled environment. In addition, our method includes processes for procedurally adding additional features such as road and rail networks. The resulting models meet the increasing needs in urban environments for planning, inventory, and analysis

  2. A model to determine payments associated with radiology procedures.

    Science.gov (United States)

    Mabotuwana, Thusitha; Hall, Christopher S; Thomas, Shiby; Wald, Christoph

    2017-12-01

    Across the United States, there is a growing number of patients in Accountable Care Organizations and under risk contracts with commercial insurance. This is due to proliferation of new value-based payment models and care delivery reform efforts. In this context, the business model of radiology within a hospital or health system context is shifting from a primary profit-center to a cost-center with a goal of cost savings. Radiology departments need to increasingly understand how the transactional nature of the business relates to financial rewards. The main challenge with current reporting systems is that the information is presented only at an aggregated level, and often not broken down further, for instance, by type of exam. As such, the primary objective of this research is to provide better visibility into payments associated with individual radiology procedures in order to better calibrate expense/capital structure of the imaging enterprise to the actual revenue or value-add to the organization it belongs to. We propose a methodology that can be used to determine technical payments at a procedure level. We use a proportion based model to allocate payments to individual radiology procedures based on total charges (which also includes non-radiology related charges). Using a production dataset containing 424,250 radiology exams we calculated the overall average technical charge for Radiology to be $873.08 per procedure and the corresponding average payment to be $326.43 (range: $48.27 for XR and $2750.11 for PET/CT) resulting in an average payment percentage of 37.39% across all exams. We describe how charges associated with a procedure can be used to approximate technical payments at a more granular level with a focus on Radiology. The methodology is generalizable to approximate payment for other services as well. Understanding payments associated with each procedure can be useful during strategic practice planning. Charge-to-total charge ratio can be used to

  3. Technical innovation: Intragastric Single Port Sleeve Gastrectomy (IGSG). A feasibility survival study on porcine model.

    Science.gov (United States)

    Estupinam, Oscar; Oliveira, André Lacerda de Abreu; Antunes, Fernanda; Galvão, Manoel; Phillips, Henrique; Scheffer, Jussara Peters; Rios, Marcelo; Zorron, Ricardo

    2018-01-01

    To perform technically the laparoscopic sleeve gastrectomy (LSG) using a unique Intragastric Single Port (IGSG) in animal swine model, evidencing an effective and safe procedure, optimizing the conventional technique. IGSG was performed in 4 minipigs, using a percutaneous intragastric single port located in the pre-pyloric region. The gastric stapling of the greater curvature started from the pre-pyloric region towards the angle of His by Endo GIA™ system and the specimen was removed through the single port. In the postoperative day 30, the animals were sacrificed and submitted to autopsy. All procedures were performed without conversion, and all survived 30 days. The mean operative time was 42 min. During the perioperative period no complications were observed during invagination and stapling. No postoperative complications occurred. Post-mortem examination showed no leaks or infectious complications. Intragastric Single Port is a feasible procedure that may be a suitable alternative technique of sleeve gastrectomy for the treatment of morbid obesity.

  4. Spiral model of procedural cycle of educational process management

    OpenAIRE

    Bezrukov Valery I.; Lukashina Elena V.

    2016-01-01

    The article analyzes the nature and characteristics of the spiral model Procedure educational systems management cycle. The authors identify patterns between the development of information and communication technologies and the transformation of the education management process, give the characteristics of the concept of “information literacy” and “Media Education”. Consider the design function, determine its potential in changing the traditional educational paradigm to the new - information....

  5. Model of Procedure Usage – Results from a Qualitative Study to Inform Design of Computer-Based Procedures

    Energy Technology Data Exchange (ETDEWEB)

    Johanna H Oxstrand; Katya L Le Blanc

    2012-07-01

    The nuclear industry is constantly trying to find ways to decrease the human error rate, especially the human errors associated with procedure use. As a step toward the goal of improving procedure use performance, researchers, together with the nuclear industry, have been looking at replacing the current paper-based procedures with computer-based procedure systems. The concept of computer-based procedures is not new by any means; however most research has focused on procedures used in the main control room. Procedures reviewed in these efforts are mainly emergency operating procedures and normal operating procedures. Based on lessons learned for these previous efforts we are now exploring a more unknown application for computer based procedures - field procedures, i.e. procedures used by nuclear equipment operators and maintenance technicians. The Idaho National Laboratory, the Institute for Energy Technology, and participants from the U.S. commercial nuclear industry are collaborating in an applied research effort with the objective of developing requirements and specifications for a computer-based procedure system to be used by field operators. The goal is to identify the types of human errors that can be mitigated by using computer-based procedures and how to best design the computer-based procedures to do this. The underlying philosophy in the research effort is “Stop – Start – Continue”, i.e. what features from the use of paper-based procedures should we not incorporate (Stop), what should we keep (Continue), and what new features or work processes should be added (Start). One step in identifying the Stop – Start – Continue was to conduct a baseline study where affordances related to the current usage of paper-based procedures were identified. The purpose of the study was to develop a model of paper based procedure use which will help to identify desirable features for computer based procedure prototypes. Affordances such as note taking, markups

  6. Drawing-Based Procedural Modeling of Chinese Architectures.

    Science.gov (United States)

    Fei Hou; Yue Qi; Hong Qin

    2012-01-01

    This paper presents a novel modeling framework to build 3D models of Chinese architectures from elevation drawing. Our algorithm integrates the capability of automatic drawing recognition with powerful procedural modeling to extract production rules from elevation drawing. First, different from the previous symbol-based floor plan recognition, based on the novel concept of repetitive pattern trees, small horizontal repetitive regions of the elevation drawing are clustered in a bottom-up manner to form architectural components with maximum repetition, which collectively serve as building blocks for 3D model generation. Second, to discover the global architectural structure and its components' interdependencies, the components are structured into a shape tree in a top-down subdivision manner and recognized hierarchically at each level of the shape tree based on Markov Random Fields (MRFs). Third, shape grammar rules can be derived to construct 3D semantic model and its possible variations with the help of a 3D component repository. The salient contribution lies in the novel integration of procedural modeling with elevation drawing, with a unique application to Chinese architectures.

  7. Neuro-developmental outcome in single-ventricle patients: is the Norwood procedure a risk factor?

    Science.gov (United States)

    Rotermann, Ina; Logoteta, Jana; Falta, Janine; Wegner, Philip; Jung, Olaf; Dütschke, Peter; Scheewe, Jens; Kramer, Hans-Heiner; Hansen, Jan Hinnerk

    2017-09-01

    Complex neonatal surgery is considered a risk factor for neuro-developmental impairment in single-ventricle patients. Neuro-developmental outcome was compared between preschool-aged Fontan patients who underwent a Norwood procedure and single-ventricle patients not requiring neonatal surgery with cardiopulmonary bypass. Verbal, performance and full-scale intelligence quotient (IQ) were evaluated with the Wechsler Preschool and Primary Scale of Intelligence. Cognitive functions were assessed with the German 'Kognitiver Entwicklungstest für das Kindergartenalter' (KET-KID). Risk factors for impaired neuro-development were evaluated. Neuro-developmental assessment was completed in 95 patients (Norwood: n = 69; non-Norwood: n = 26). Median (interquartile range) IQ and KET-KID scores were in the normal range. Except for verbal KET-KID, scores did not differ between Norwood and non-Norwood patients (verbal IQ: 98 (86-105) vs 93 (85-102), P = 0.312; performance IQ: 91 (86-100) vs 96 (86-100), P = 0.932; full-scale IQ: 93 (86-101) vs 89 (84-98), P = 0.314; KET-KID verbal: 48 (17-72) vs 25 (2-54), P = 0.020; KET-KID non-verbal: 33 (18-62) vs 45 (15-54), P = 0.771; KET-KID global: 42 (14-65) vs 28 (6-63), P = 0.208). Full-scale IQ was below average (<85 points) in 14 (20%) Norwood and 9 (35%) non-Norwood cases (P = 0.181). Global KET-KID was below average (<16th percentile) in 19 (28%) and 10 (38%) patients (P = 0.326). Smaller head circumference z-score and complications before neonatal surgery were independently associated with lower scores. Neuro-developmental outcome of preschool-aged Fontan patients was in the normal range. The Norwood procedure was not a risk factor for neuro-developmental impairment. Preoperative condition and patient-related factors were more important determinants than variables related to surgical palliation. © The Author 2017. Published by Oxford University Press on behalf of the European Association for

  8. Recreation of architectural structures using procedural modeling based on volumes

    Directory of Open Access Journals (Sweden)

    Santiago Barroso Juan

    2013-11-01

    Full Text Available While the procedural modeling of buildings and other architectural structures has evolved very significantly in recent years, there is noticeable absence of high-level tools that allow a designer, an artist or an historian, creating important buildings or architectonic structures in a particular city. In this paper we present a tool for creating buildings in a simple and clear, following rules that use the language and methodology of creating their own buildings, and hiding the user the algorithmic details of the creation of the model.

  9. Procedural Modeling for Rapid-Prototyping of Multiple Building Phases

    Science.gov (United States)

    Saldana, M.; Johanson, C.

    2013-02-01

    RomeLab is a multidisciplinary working group at UCLA that uses the city of Rome as a laboratory for the exploration of research approaches and dissemination practices centered on the intersection of space and time in antiquity. In this paper we present a multiplatform workflow for the rapid-prototyping of historical cityscapes through the use of geographic information systems, procedural modeling, and interactive game development. Our workflow begins by aggregating archaeological data in a GIS database. Next, 3D building models are generated from the ArcMap shapefiles in Esri CityEngine using procedural modeling techniques. A GIS-based terrain model is also adjusted in CityEngine to fit the building elevations. Finally, the terrain and city models are combined in Unity, a game engine which we used to produce web-based interactive environments which are linked to the GIS data using keyhole markup language (KML). The goal of our workflow is to demonstrate that knowledge generated within a first-person virtual world experience can inform the evaluation of data derived from textual and archaeological sources, and vice versa.

  10. Stepwise calibration procedure for regional coupled hydrological-hydrogeological models

    Science.gov (United States)

    Labarthe, Baptiste; Abasq, Lena; de Fouquet, Chantal; Flipo, Nicolas

    2014-05-01

    Stream-aquifer interaction is a complex process depending on regional and local processes. Indeed, the groundwater component of hydrosystem and large scale heterogeneities control the regional flows towards the alluvial plains and the rivers. In second instance, the local distribution of the stream bed permeabilities controls the dynamics of stream-aquifer water fluxes within the alluvial plain, and therefore the near-river piezometric head distribution. In order to better understand the water circulation and pollutant transport in watersheds, the integration of these multi-dimensional processes in modelling platform has to be performed. Thus, the nested interfaces concept in continental hydrosystem modelling (where regional fluxes, simulated by large scale models, are imposed at local stream-aquifer interfaces) has been presented in Flipo et al (2014). This concept has been implemented in EauDyssée modelling platform for a large alluvial plain model (900km2) part of a 11000km2 multi-layer aquifer system, located in the Seine basin (France). The hydrosystem modelling platform is composed of four spatially distributed modules (Surface, Sub-surface, River and Groundwater), corresponding to four components of the terrestrial water cycle. Considering the large number of parameters to be inferred simultaneously, the calibration process of coupled models is highly computationally demanding and therefore hardly applicable to a real case study of 10000km2. In order to improve the efficiency of the calibration process, a stepwise calibration procedure is proposed. The stepwise methodology involves determining optimal parameters of all components of the coupled model, to provide a near optimum prior information for the global calibration. It starts with the surface component parameters calibration. The surface parameters are optimised based on the comparison between simulated and observed discharges (or filtered discharges) at various locations. Once the surface parameters

  11. Modeling the Activity of Single Genes

    Science.gov (United States)

    Mjolsness, Eric; Gibson, Michael

    1999-01-01

    the key questions in gene regulation are: What genes are expressed in a certain cell at a certain time? How does gene expression differ from cell to cell in a multicellular organism? Which proteins act as transcription factors, i.e., are important in regulating gene expression? From questions like these, we hope to understand which genes are important for various macroscopic processes. Nearly all of the cells of a multicellular organism contain the same DNA. Yet this same genetic information yields a large number of different cell types. The fundamental difference between a neuron and a liver cell, for example, is which genes are expressed. Thus understanding gene regulation is an important step in understanding development. Furthermore, understanding the usual genes that are expressed in cells may give important clues about various diseases. Some diseases, such as sickle cell anemia and cystic fibrosis, are caused by defects in single, non-regulatory genes; others, such as certain cancers, are caused when the cellular control circuitry malfunctions - an understanding of these diseases will involve pathways of multiple interacting gene products. There are numerous challenges in the area of understanding and modeling gene regulation. First and foremost, biologists would like to develop a deeper understanding of the processes involved, including which genes and families of genes are important, how they interact, etc. From a computation point of view, there has been embarrassingly little work done. In this chapter there are many areas in which we can phrase meaningful, non-trivial computational questions, but questions that have not been addressed. Some of these are purely computational (what is a good algorithm for dealing with a model of type X) and others are more mathematical (given a system with certain characteristics, what sort of model can one use? How does one find biochemical parameters from system-level behavior using as few experiments as possible?). In

  12. A Bidirectional Coupling Procedure Applied to Multiscale Respiratory Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Kuprat, Andrew P.; Kabilan, Senthil; Carson, James P.; Corley, Richard A.; Einstein, Daniel R.

    2013-07-01

    In this study, we present a novel multiscale computational framework for efficiently linking multiple lower-dimensional models describing the distal lung mechanics to imaging-based 3D computational fluid dynamics (CFD) models of the upper pulmonary airways in order to incorporate physiologically appropriate outlet boundary conditions. The framework is an extension of the Modified Newton’s Method with nonlinear Krylov accelerator developed by Carlson and Miller [1, 2, 3]. Our extensions include the retention of subspace information over multiple timesteps, and a special correction at the end of a timestep that allows for corrections to be accepted with verified low residual with as little as a single residual evaluation per timestep on average. In the case of a single residual evaluation per timestep, the method has zero additional computational cost compared to uncoupled or unidirectionally coupled simulations. We expect these enhancements to be generally applicable to other multiscale coupling applications where timestepping occurs. In addition we have developed a “pressure-drop” residual which allows for stable coupling of flows between a 3D incompressible CFD application and another (lower-dimensional) fluid system. We expect this residual to also be useful for coupling non-respiratory incompressible fluid applications, such as multiscale simulations involving blood flow. The lower-dimensional models that are considered in this study are sets of simple ordinary differential equations (ODEs) representing the compliant mechanics of symmetric human pulmonary airway trees. To validate the method, we compare the predictions of hybrid CFD-ODE models against an ODE-only model of pulmonary airflow in an idealized geometry. Subsequently, we couple multiple sets of ODEs describing the distal lung to an imaging-based human lung geometry. Boundary conditions in these models consist of atmospheric pressure at the mouth and intrapleural pressure applied to the multiple

  13. A bidirectional coupling procedure applied to multiscale respiratory modeling

    Energy Technology Data Exchange (ETDEWEB)

    Kuprat, A.P., E-mail: andrew.kuprat@pnnl.gov [Fundamental and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA (United States); Kabilan, S., E-mail: senthil.kabilan@pnnl.gov [Fundamental and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA (United States); Carson, J.P., E-mail: james.carson@pnnl.gov [Fundamental and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA (United States); Corley, R.A., E-mail: rick.corley@pnnl.gov [Fundamental and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA (United States); Einstein, D.R., E-mail: daniel.einstein@pnnl.gov [Fundamental and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA (United States)

    2013-07-01

    In this study, we present a novel multiscale computational framework for efficiently linking multiple lower-dimensional models describing the distal lung mechanics to imaging-based 3D computational fluid dynamics (CFDs) models of the upper pulmonary airways in order to incorporate physiologically appropriate outlet boundary conditions. The framework is an extension of the modified Newton’s method with nonlinear Krylov accelerator developed by Carlson and Miller [1], Miller [2] and Scott and Fenves [3]. Our extensions include the retention of subspace information over multiple timesteps, and a special correction at the end of a timestep that allows for corrections to be accepted with verified low residual with as little as a single residual evaluation per timestep on average. In the case of a single residual evaluation per timestep, the method has zero additional computational cost compared to uncoupled or unidirectionally coupled simulations. We expect these enhancements to be generally applicable to other multiscale coupling applications where timestepping occurs. In addition we have developed a “pressure-drop” residual which allows for stable coupling of flows between a 3D incompressible CFD application and another (lower-dimensional) fluid system. We expect this residual to also be useful for coupling non-respiratory incompressible fluid applications, such as multiscale simulations involving blood flow. The lower-dimensional models that are considered in this study are sets of simple ordinary differential equations (ODEs) representing the compliant mechanics of symmetric human pulmonary airway trees. To validate the method, we compare the predictions of hybrid CFD–ODE models against an ODE-only model of pulmonary airflow in an idealized geometry. Subsequently, we couple multiple sets of ODEs describing the distal lung to an imaging-based human lung geometry. Boundary conditions in these models consist of atmospheric pressure at the mouth and intrapleural

  14. A bidirectional coupling procedure applied to multiscale respiratory modeling

    International Nuclear Information System (INIS)

    Kuprat, A.P.; Kabilan, S.; Carson, J.P.; Corley, R.A.; Einstein, D.R.

    2013-01-01

    In this study, we present a novel multiscale computational framework for efficiently linking multiple lower-dimensional models describing the distal lung mechanics to imaging-based 3D computational fluid dynamics (CFDs) models of the upper pulmonary airways in order to incorporate physiologically appropriate outlet boundary conditions. The framework is an extension of the modified Newton’s method with nonlinear Krylov accelerator developed by Carlson and Miller [1], Miller [2] and Scott and Fenves [3]. Our extensions include the retention of subspace information over multiple timesteps, and a special correction at the end of a timestep that allows for corrections to be accepted with verified low residual with as little as a single residual evaluation per timestep on average. In the case of a single residual evaluation per timestep, the method has zero additional computational cost compared to uncoupled or unidirectionally coupled simulations. We expect these enhancements to be generally applicable to other multiscale coupling applications where timestepping occurs. In addition we have developed a “pressure-drop” residual which allows for stable coupling of flows between a 3D incompressible CFD application and another (lower-dimensional) fluid system. We expect this residual to also be useful for coupling non-respiratory incompressible fluid applications, such as multiscale simulations involving blood flow. The lower-dimensional models that are considered in this study are sets of simple ordinary differential equations (ODEs) representing the compliant mechanics of symmetric human pulmonary airway trees. To validate the method, we compare the predictions of hybrid CFD–ODE models against an ODE-only model of pulmonary airflow in an idealized geometry. Subsequently, we couple multiple sets of ODEs describing the distal lung to an imaging-based human lung geometry. Boundary conditions in these models consist of atmospheric pressure at the mouth and intrapleural

  15. a Procedural Solution to Model Roman Masonry Structures

    Science.gov (United States)

    Cappellini, V.; Saleri, R.; Stefani, C.; Nony, N.; De Luca, L.

    2013-07-01

    The paper will describe a new approach based on the development of a procedural modelling methodology for archaeological data representation. This is a custom-designed solution based on the recognition of the rules belonging to the construction methods used in roman times. We have conceived a tool for 3D reconstruction of masonry structures starting from photogrammetric surveying. Our protocol considers different steps. Firstly we have focused on the classification of opus based on the basic interconnections that can lead to a descriptive system used for their unequivocal identification and design. Secondly, we have chosen an automatic, accurate, flexible and open-source photogrammetric pipeline named Pastis Apero Micmac - PAM, developed by IGN (Paris). We have employed it to generate ortho-images from non-oriented images, using a user-friendly interface implemented by CNRS Marseille (France). Thirdly, the masonry elements are created in parametric and interactive way, and finally they are adapted to the photogrammetric data. The presented application, currently under construction, is developed with an open source programming language called Processing, useful for visual, animated or static, 2D or 3D, interactive creations. Using this computer language, a Java environment has been developed. Therefore, even if the procedural modelling reveals an accuracy level inferior to the one obtained by manual modelling (brick by brick), this method can be useful when taking into account the static evaluation on buildings (requiring quantitative aspects) and metric measures for restoration purposes.

  16. Qualitative mechanism models and the rationalization of procedures

    Science.gov (United States)

    Farley, Arthur M.

    1989-01-01

    A qualitative, cluster-based approach to the representation of hydraulic systems is described and its potential for generating and explaining procedures is demonstrated. Many ideas are formalized and implemented as part of an interactive, computer-based system. The system allows for designing, displaying, and reasoning about hydraulic systems. The interactive system has an interface consisting of three windows: a design/control window, a cluster window, and a diagnosis/plan window. A qualitative mechanism model for the ORS (Orbital Refueling System) is presented to coordinate with ongoing research on this system being conducted at NASA Ames Research Center.

  17. Bentall procedure: quarter century of clinical experiences of a single surgeon.

    Science.gov (United States)

    Benke, Kálmán; Ágg, Bence; Szabó, Lilla; Szilveszter, Bálint; Odler, Balázs; Pólos, Miklós; Cao, Chun; Maurovich-Horvat, Pál; Radovits, Tamás; Merkely, Béla; Szabolcs, Zoltán

    2016-01-22

    We retrospectively analyzed 25 years of experiences with the button Bentall procedure in patients with aortic root pathologies. Even though this procedure has become widespread, there are only a few very long term follow-ups available in the clinical literature, especially regarding single surgeon results. Between 1988 and 2013, a total of 147 patients underwent the Bentall procedure by the same surgeon. Among them there were 62 patients with Marfan syndrome. At the time of the surgery the mean age was 46.5 ± 17.6 years. The impact of surgical experience on long-term survival was evaluated using a cumulative sum analysis chart. The Kaplan-Meier estimated overall survival rates for the 147 patients were 91.8 ± 2.3 %, 84.3 ± 3.1 %, 76.3 ± 4.9 % and 59.5 ± 10.7 % at 1,5,10 and 20 years, respectively. Multivariate Cox regression analysis identified EuroSCORE II over 3 % (OR 4.245, 95 % CI, 1.739-10.364, p = 0.002), acute indication (OR 2.942, 95 % CI, 1.158-7.480, p = 0.023), use of deep hypothermic circulatory arrest (OR 3.267, 95 % CI, 1.283-8.323, p = 0.013), chronic kidney disease (OR 6.865, 95 % CI, 1.339-35.189, p = 0.021) and early complication (OR 3.134, 95 % CI, 1.246-7.883, p = 0.015) as significant risk factors for the late overall death. The survival rate for freedom from early complication was 94.3 ± 2.2 %, 88.0 ± 3.3 %, 82.9 ± 4.7 % and 69.2 ± 8.4 % at 1,5,10 and 20 years. The main pathological findings of the aortic wall were cystic medial degeneration in 75 %, fibrosis in 6 %, atherosclerosis in 13 % and no pathological alteration in 6 % of the samples. The overall survival rate was significantly lower in patients operated in first 15 years compared to patients operated in the last decade (log-rank p = 0.011). According to our long-term follow-up the Bentall operation provides an appropriate functional result by resolving the lesions of the ascending aorta. Based on our results, 25-30 operations done is necessary to gain such a level of

  18. Addressing challenges in single species assessments via a simple state-space assessment model

    DEFF Research Database (Denmark)

    Nielsen, Anders

    Single-species and age-structured fish stock assessments still remains the main tool for managing fish stocks. A simple state-space assessment model is presented as an alternative to (semi) deterministic procedures and the full parametric statistical catch at age models. It offers a solution...... to some of the key challenges of these models. Compared to the deterministic procedures it solves a list of problems originating from falsely assuming that age classified catches are known without errors and allows quantification of uncertainties of estimated quantities of interest. Compared to full...

  19. Two-stage IMZ implants and ITI implants inserted in a single-stage procedure : A prospective comparative study

    NARCIS (Netherlands)

    Heydenrijk, Kees; Raghoebar, Gerry M.; Meijer, Henny J.A.; Reijden, Willy A. van der; Winkelhoff, Arie Jan van; Stegenga, Boudewijn

    2002-01-01

    The aim of this study was to evaluate the feasibility of using a two-stage implant system in a single-stage procedure and to study the impact of the microgap at crestal level and to monitor the microflora in the peri-implant area. Forty edentulous patients (Cawood & Howell class V–VI) participated

  20. Two-stage IMZ implants and ITI implants inserted in a single-stage procedure - A prospective comparative study

    NARCIS (Netherlands)

    Heydenrijk, K; Raghoebar, GM; Meijer, HJA; van der Reijden, WA; van Winkelhoff, AJ; Stegenga, B

    The aim of this study was to evaluate the feasibility of using a two-stage implant system in a single-stage procedure and to study the impact of the microgap at crestal level and to monitor the microflora in the peri-implant area. Forty edentulous patients (Cawood & Howell class V-VI) participated

  1. Blood vessel modeling for interactive simulation of interventional neuroradiology procedures.

    Science.gov (United States)

    Kerrien, E; Yureidini, A; Dequidt, J; Duriez, C; Anxionnat, R; Cotin, S

    2017-01-01

    Endovascular interventions can benefit from interactive simulation in their training phase but also during pre-operative and intra-operative phases if simulation scenarios are based on patient data. A key feature in this context is the ability to extract, from patient images, models of blood vessels that impede neither the realism nor the performance of simulation. This paper addresses both the segmentation and reconstruction of the vasculature from 3D Rotational Angiography data, and adapted to simulation: An original tracking algorithm is proposed to segment the vessel tree while filtering points extracted at the vessel surface in the vicinity of each point on the centerline; then an automatic procedure is described to reconstruct each local unstructured point set as a skeleton-based implicit surface (blobby model). The output of successively applying both algorithms is a new model of vasculature as a tree of local implicit models. The segmentation algorithm is compared with Multiple Hypothesis Testing (MHT) algorithm (Friman et al., 2010) on patient data, showing its greater ability to track blood vessels. The reconstruction algorithm is evaluated on both synthetic and patient data and demonstrate its ability to fit points with a subvoxel precision. Various tests are also reported where our model is used to simulate catheter navigation in interventional neuroradiology. An excellent realism, and much lower computational costs are reported when compared to triangular mesh surface models. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Effect of Different Saliva Decontamination Procedures on Bond Strength to Dentin in Single Bottle Systems

    Directory of Open Access Journals (Sweden)

    M. Ghavam

    2004-09-01

    Full Text Available Statement of Problem: Following the increasing use of composites in restoring anterior and posterior teeth, problems due to its technique sensitivity have become a major concern.One of these problems is the possibility of contamination of dentin with saliva, blood and/or gingival fluid in different stages of bonding procedure, even with application of different methods of isolation. However, by introduction of Single-bottle dentin adhesives,the contamination possibility reduced to two stages. Scientific documents show that saliva contamination reduces bond strength of composites to dentin. Application of simple and efficient methods for reducing or eliminating saliva contamination enables clinicians to carry out dental treatment without any concern about deterioration of clinical longevity of restoration.Purpose: This study was designed to compare the effect of different decontamination methods on the shear bond strength of composite to dentin using a “Single-bottle” adhesive.Materials and Methods: Seventy-two extracted sound human molars and premolars were selected. Enamel of buccal surface was ground flat to expose dentin. The teeth were divided into 9 groups of 8 each. In control group (1 the adhesive “Excite” was used according tothe manufacturer, without any contamination. Conditioned and saliva contaminated dentin was (2 rinsed and blot dried, (3 rinsed, dried and re-etched. In groups 4, 5, 6 uncured adhesive was saliva contaminated and then: (4 only blot dried (5 rinsed, blot dried with adhesive reapplication and (6 resurfaced with bur, rinsed, dried and followed by repeating the whole process. In groups 7, 8, 9 cured adhesive was contaminated with saliva and then:(7 rinsed and dried (8 rinsed, blot dried with adhesive reapplication (9 same as group (6.Then “Tetric Ceram” composite cylinders were bonded to dentin surfaces. Samples were thermo cycled in 5°C and 55°C water, 30 seconds in each bath with a dowel time of 10

  3. A Procedure for Modeling Photovoltaic Arrays under Any Configuration and Shading Conditions

    Directory of Open Access Journals (Sweden)

    Daniel Gonzalez Montoya

    2018-03-01

    Full Text Available Photovoltaic (PV arrays can be connected following regular or irregular connection patterns to form regular configurations (e.g., series-parallel, total cross-tied, bridge-linked, etc. or irregular configurations, respectively. Several reported works propose models for a single configuration; hence, making the evaluation of arrays with different configuration is a considerable time-consuming task. Moreover, if the PV array adopts an irregular configuration, the classical models cannot be used for its analysis. This paper proposes a modeling procedure for PV arrays connected in any configuration and operating under uniform or partial shading conditions. The procedure divides the array into smaller arrays, named sub-arrays, which can be independently solved. The modeling procedure selects the mesh current solution or the node voltage solution depending on the topology of each sub-array. Therefore, the proposed approach analyzes the PV array using the least number of nonlinear equations. The proposed solution is validated through simulation and experimental results, which demonstrate the proposed model capacity to reproduce the electrical behavior of PV arrays connected in any configuration.

  4. Lumping procedure for a kinetic model of catalytic naphtha reforming

    Directory of Open Access Journals (Sweden)

    H. M. Arani

    2009-12-01

    Full Text Available A lumping procedure is developed for obtaining kinetic and thermodynamic parameters of catalytic naphtha reforming. All kinetic and deactivation parameters are estimated from industrial data and thermodynamic parameters are calculated from derived mathematical expressions. The proposed model contains 17 lumps that include the C6 to C8+ hydrocarbon range and 15 reaction pathways. Hougen-Watson Langmuir-Hinshelwood type reaction rate expressions are used for kinetic simulation of catalytic reactions. The kinetic parameters are benchmarked with several sets of plant data and estimated by the SQP optimization method. After calculation of deactivation and kinetic parameters, plant data are compared with model predictions and only minor deviations between experimental and calculated data are generally observed.

  5. Procedures and Methods of Digital Modeling in Representation Didactics

    Science.gov (United States)

    La Mantia, M.

    2011-09-01

    At the Bachelor degree course in Engineering/Architecture of the University "La Sapienza" of Rome, the courses of Design and Survey, in addition to considering the learning of methods of representation, the application of descriptive geometry and survey, in order to expand the vision and spatial conception of the student, pay particular attention to the use of information technology for the preparation of design and survey drawings, achieving their goals through an educational path of "learning techniques, procedures and methods of modeling architectural structures." The fields of application involved two different educational areas: the analysis and that of survey, both from the acquisition of the given metric (design or survey) to the development of three-dimensional virtual model.

  6. Block Empirical Likelihood for Longitudinal Single-Index Varying-Coefficient Model

    Directory of Open Access Journals (Sweden)

    Yunquan Song

    2013-01-01

    Full Text Available In this paper, we consider a single-index varying-coefficient model with application to longitudinal data. In order to accommodate the within-group correlation, we apply the block empirical likelihood procedure to longitudinal single-index varying-coefficient model, and prove a nonparametric version of Wilks’ theorem which can be used to construct the block empirical likelihood confidence region with asymptotically correct coverage probability for the parametric component. In comparison with normal approximations, the proposed method does not require a consistent estimator for the asymptotic covariance matrix, making it easier to conduct inference for the model's parametric component. Simulations demonstrate how the proposed method works.

  7. WINKLER'S SINGLE-PARAMETER SUBGRADE MODEL FROM ...

    African Journals Online (AJOL)

    Preferred Customer

    SUBGRADE MODELING. Asrat Worku. Department of ... The models give consistently larger stiffness for the Winkler springs as compared to previously proposed similar continuum-based models that ignore the lateral stresses. ...... (ν = 0.25 and E = 40MPa); (b) a medium stiff clay (ν = 0.45 and E = 50MPa). In contrast to this, ...

  8. Generalized Functional Linear Models With Semiparametric Single-Index Interactions

    KAUST Repository

    Li, Yehua

    2010-06-01

    We introduce a new class of functional generalized linear models, where the response is a scalar and some of the covariates are functional. We assume that the response depends on multiple covariates, a finite number of latent features in the functional predictor, and interaction between the two. To achieve parsimony, the interaction between the multiple covariates and the functional predictor is modeled semiparametrically with a single-index structure. We propose a two step estimation procedure based on local estimating equations, and investigate two situations: (a) when the basis functions are pre-determined, e.g., Fourier or wavelet basis functions and the functional features of interest are known; and (b) when the basis functions are data driven, such as with functional principal components. Asymptotic properties are developed. Notably, we show that when the functional features are data driven, the parameter estimates have an increased asymptotic variance, due to the estimation error of the basis functions. Our methods are illustrated with a simulation study and applied to an empirical data set, where a previously unknown interaction is detected. Technical proofs of our theoretical results are provided in the online supplemental materials.

  9. Single-cluster dynamics for the random-cluster model

    NARCIS (Netherlands)

    Deng, Y.; Qian, X.; Blöte, H.W.J.

    2009-01-01

    We formulate a single-cluster Monte Carlo algorithm for the simulation of the random-cluster model. This algorithm is a generalization of the Wolff single-cluster method for the q-state Potts model to noninteger values q>1. Its results for static quantities are in a satisfactory agreement with those

  10. Single-Pass Percutaneous Liver Biopsy for Diffuse Liver Disease Using an Automated Device: Experience in 154 Procedures

    International Nuclear Information System (INIS)

    Rivera-Sanfeliz, Gerant; Kinney, Thomas B.; Rose, Steven C.; Agha, Ayad K.M.; Valji, Karim; Miller, Franklin J.; Roberts, Anne C.

    2005-01-01

    Purpose: To describe our experience with ultrasound (US)-guided percutaneous liver biopsies using the INRAD 18G Express core needle biopsy system.Methods: One hundred and fifty-four consecutive percutaneous core liver biopsy procedures were performed in 153 men in a single institution over 37 months. The medical charts, pathology reports, and radiology files were retrospectively reviewed. The number of needle passes, type of guidance, change in hematocrit level, and adequacy of specimens for histologic analysis were evaluated.Results: All biopsies were performed for histologic staging of chronic liver diseases. The majority of patients had hepatitis C (134/153, 90.2%). All patients were discharged to home after 4 hr of postprocedural observation. In 145 of 154 (94%) biopsies, a single needle pass was sufficient for diagnosis. US guidance was utilized in all but one of the procedures (153/154, 99.4%). The mean hematocrit decrease was 1.2% (44.1-42.9%). Pain requiring narcotic analgesia, the most frequent complication, occurred in 28 of 154 procedures (18.2%). No major complications occurred. The specimens were diagnostic in 152 of 154 procedures (98.7%).Conclusions: Single-pass percutaneous US-guided liver biopsy with the INRAD 18G Express core needle biopsy system is safe and provides definitive pathologic diagnosis of chronic liver disease. It can be performed on an outpatient basis. Routine post-biopsy monitoring of hematocrit level in stable, asymptomatic patients is probably not warranted

  11. State Token Petri Net modeling method for formal verification of computerized procedure including operator's interruptions of procedure execution flow

    International Nuclear Information System (INIS)

    Kim, Yun Goo; Seong, Poong Hyun

    2012-01-01

    The Computerized Procedure System (CPS) is one of the primary operating support systems in the digital Main Control Room. The CPS displays procedure on the computer screen in the form of a flow chart, and displays plant operating information along with procedure instructions. It also supports operator decision making by providing a system decision. A procedure flow should be correct and reliable, as an error would lead to operator misjudgement and inadequate control. In this paper we present a modeling for the CPS that enables formal verification based on Petri nets. The proposed State Token Petri Nets (STPN) also support modeling of a procedure flow that has various interruptions by the operator, according to the plant condition. STPN modeling is compared with Coloured Petri net when they are applied to Emergency Operating Computerized Procedure. A converting program for Computerized Procedure (CP) to STPN has been also developed. The formal verification and validation methods of CP with STPN increase the safety of a nuclear power plant and provide digital quality assurance means that are needed when the role and function of the CPS is increasing.

  12. GENERATING ALTERNATIVE PROPOSALS FOR THE LOUVRE USING PROCEDURAL MODELING

    Directory of Open Access Journals (Sweden)

    E. Calogero

    2012-09-01

    Full Text Available This paper presents the process of reconstructing two facade designs for the East wing of the Louvre using procedural modeling. The first proposal reconstructed is Louis Le Vau's 1662 scheme and the second is the 1668 design of the "petit conseil" that still stands today. The initial results presented show how such reconstructions may aid general and expert understanding of the two designs. It is claimed that by formalizing the facade description into a shape grammar in CityEngine, a systematized approach to a stylistic analysis is possible. It is also asserted that such an analysis is still best understood in the historical context of what is known about the contemporary design intentions of the building creators and commissioners.

  13. Developing Physiologic Models for Emergency Medical Procedures Under Microgravity

    Science.gov (United States)

    Parker, Nigel; O'Quinn, Veronica

    2012-01-01

    Several technological enhancements have been made to METI's commercial Emergency Care Simulator (ECS) with regard to how microgravity affects human physiology. The ECS uses both a software-only lung simulation, and an integrated mannequin lung that uses a physical lung bag for creating chest excursions, and a digital simulation of lung mechanics and gas exchange. METI s patient simulators incorporate models of human physiology that simulate lung and chest wall mechanics, as well as pulmonary gas exchange. Microgravity affects how O2 and CO2 are exchanged in the lungs. Procedures were also developed to take into affect the Glasgow Coma Scale for determining levels of consciousness by varying the ECS eye-blinking function to partially indicate the level of consciousness of the patient. In addition, the ECS was modified to provide various levels of pulses from weak and thready to hyper-dynamic to assist in assessing patient conditions from the femoral, carotid, brachial, and pedal pulse locations.

  14. Generating Alternative Proposals for the Louvre Using Procedural Modeling

    Science.gov (United States)

    Calogero, E.; Arnold, D.

    2011-09-01

    This paper presents the process of reconstructing two facade designs for the East wing of the Louvre using procedural modeling. The first proposal reconstructed is Louis Le Vau's 1662 scheme and the second is the 1668 design of the "petit conseil" that still stands today. The initial results presented show how such reconstructions may aid general and expert understanding of the two designs. It is claimed that by formalizing the facade description into a shape grammar in CityEngine, a systematized approach to a stylistic analysis is possible. It is also asserted that such an analysis is still best understood in the historical context of what is known about the contemporary design intentions of the building creators and commissioners.

  15. Self-expanding metal stents for colonic obstruction: experiences from 104 procedures in a single center

    DEFF Research Database (Denmark)

    Meisner, Søren; Hensler, Margaret; Knop, Filip Krag

    2004-01-01

    In the past, colonic obstruction caused by malignancy most often resulted in high-risk operations, usually involving two-step procedures or leaving the patient with a stoma in case of disseminated disease....

  16. A procedure for determining parameters of a simplified ligament model.

    Science.gov (United States)

    Barrett, Jeff M; Callaghan, Jack P

    2018-01-03

    A previous mathematical model of ligament force-generation treated their behavior as a population of collagen fibres arranged in parallel. When damage was ignored in this model, an expression for ligament force in terms of the deflection, x, effective stiffness, k, mean collagen slack length, μ, and the standard deviation of slack lengths, σ, was obtained. We present a simple three-step method for determining the three model parameters (k, μ, and σ) from force-deflection data: (1) determine the equation of the line in the linear region of this curve, its slope is k and its x -intercept is -μ; (2) interpolate the force-deflection data when x is -μ to obtain F 0 ; (3) calculate σ with the equation σ=2πF 0 /k. Results from this method were in good agreement to those obtained from a least-squares procedure on experimental data - all falling within 6%. Therefore, parameters obtained using the proposed method provide a systematic way of reporting ligament parameters, or for obtaining an initial guess for nonlinear least-squares. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Single-layer model for surface roughness.

    Science.gov (United States)

    Carniglia, C K; Jensen, D G

    2002-06-01

    Random roughness of an optical surface reduces its specular reflectance and transmittance by the scattering of light. The reduction in reflectance can be modeled by a homogeneous layer on the surface if the refractive index of the layer is intermediate to the indices of the media on either side of the surface. Such a layer predicts an increase in the transmittance of the surface and therefore does not provide a valid model for the effects of scatter on the transmittance. Adding a small amount of absorption to the layer provides a model that predicts a reduction in both reflectance and transmittance. The absorbing layer model agrees with the predictions of a scalar scattering theory for a layer with a thickness that is twice the rms roughness of the surface. The extinction coefficient k for the layer is proportional to the thickness of the layer.

  18. Experiences with a procedure for modeling product knowledge

    DEFF Research Database (Denmark)

    Hansen, Benjamin Loer; Hvam, Lars

    2002-01-01

    This paper presents experiences with a procedure for building configurators. The procedure has been used in an American company producing custom-made precision air conditioning equipment. The paper describes experiences with the use of the procedure and experiences with the project in general....

  19. Rapid single step subcloning procedure by combined action of type II and type IIs endonucleases with ligase

    Directory of Open Access Journals (Sweden)

    Klingenspor Martin

    2007-11-01

    Full Text Available Abstract Background The subcloning of a DNA fragment from an entry vector into a destination vector is a routinely performed task in molecular biology labs. Results We here present a novel benchtop procedure to achieve rapid recombination into any destination vector of choice with the sole requirement of an endonuclease recognition site. The method relies on a specifically designed entry vector and the combined action of type II and type IIs endonucleases with ligase. The formulation leads to accumulation of a single stable cloning product representing the desired insert carrying destination vector. Conclusion The described method provides a fast single step procedure for routine subcloning from an entry vector into a series of destination vectors with the same restriction enzyme recognition site.

  20. Rapid single step subcloning procedure by combined action of type II and type IIs endonucleases with ligase.

    Science.gov (United States)

    Fromme, Tobias; Klingenspor, Martin

    2007-11-26

    The subcloning of a DNA fragment from an entry vector into a destination vector is a routinely performed task in molecular biology labs. We here present a novel benchtop procedure to achieve rapid recombination into any destination vector of choice with the sole requirement of an endonuclease recognition site. The method relies on a specifically designed entry vector and the combined action of type II and type IIs endonucleases with ligase. The formulation leads to accumulation of a single stable cloning product representing the desired insert carrying destination vector. The described method provides a fast single step procedure for routine subcloning from an entry vector into a series of destination vectors with the same restriction enzyme recognition site.

  1. Single molecule FRET data analysis procedures for FRET efficiency determination: probing the conformations of nucleic acid structures.

    Science.gov (United States)

    Krüger, Asger Christian; Birkedal, Victoria

    2013-11-01

    Single molecule FRET microscopy is an attractive technique for studying structural dynamics and conformational diversity of nucleic acid structures. Some of its strengths are that it can follow structural changes on a fast time scale and identify conformation distributions arising from dynamic or static population heterogeneity. Here, we give a description of the experiment and data analysis procedures of this method and detail what parameters are needed for FRET efficiency calculation. Using single molecule FRET data obtained on G-quadruplex DNA structures that exhibit large conformation diversity, we illustrate that the shape of the FRET distribution changes depending on what parameters are included in the data analysis procedure. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Enhancing paramedics procedural skills using a cadaveric model.

    Science.gov (United States)

    Lim, David; Bartlett, Stephen; Horrocks, Peter; Grant-Wakefield, Courtenay; Kelly, Jodie; Tippett, Vivienne

    2014-07-08

    Paramedic education has evolved in recent times from vocational post-employment to tertiary pre-employment supplemented by clinical placement. Simulation is advocated as a means of transferring learned skills to clinical practice. Sole reliance of simulation learning using mannequin-based models may not be sufficient to prepare students for variance in human anatomy. In 2012, we trialled the use of fresh frozen human cadavers to supplement undergraduate paramedic procedural skill training. The purpose of this study is to evaluate whether cadaveric training is an effective adjunct to mannequin simulation and clinical placement. A multi-method approach was adopted. The first step involved a Delphi methodology to formulate and validate the evaluation instrument. The instrument comprised of knowledge-based MCQs, Likert for self-evaluation of procedural skills and behaviours, and open answer. The second step involved a pre-post evaluation of the 2013 cadaveric training. One hundred and fourteen students attended the workshop and 96 evaluations were included in the analysis, representing a return rate of 84%. There was statistically significant improved anatomical knowledge after the workshop. Students' self-rated confidence in performing procedural skills on real patients improved significantly after the workshop: inserting laryngeal mask (MD 0.667), oropharyngeal (MD 0.198) and nasopharyngeal (MD 0.600) airways, performing Bag-Valve-Mask (MD 0.379), double (MD 0.344) and triple (MD 0.326,) airway manoeuvre, doing 12-lead electrocardiography (MD 0.729), using laryngoscope (MD 0.726), using Magill® forceps to remove foreign body (MD 0.632), attempting thoracocentesis (MD 1.240), and putting on a traction splint (MD 0.865). The students commented that the workshop provided context to their theoretical knowledge and that they gained an appreciation of the differences in normal tissue variation. Following engagement in/ completion of the workshop, students were more aware

  3. Application of a procedure oriented crew model to modelling nuclear plant operation

    International Nuclear Information System (INIS)

    Baron, S.

    1986-01-01

    PROCRU (PROCEDURE-ORIENTED CREW MODEL) is a model developed to analyze flight crew procedures in a commercial ILS approach-to-landing. The model builds on earlier, validated control-theoretic models for human estimation and control behavior, but incorporates features appropriate to analyzing supervisory control in multi-task environments. In this paper, the basic ideas underlying the PROCRU model, and the generalization of these ideas to provide a supervisory control model of wider applicability are discussed. The potential application of this supervisory control model to nuclear power plant operations is considered. The range of problems that can be addressed, the kinds of data that will be needed and the nature of the results that might be expected from such an application are indicated

  4. Sensitivity of Hydrologic Response to Climate Model Debiasing Procedures

    Science.gov (United States)

    Channell, K.; Gronewold, A.; Rood, R. B.; Xiao, C.; Lofgren, B. M.; Hunter, T.

    2017-12-01

    Climate change is already having a profound impact on the global hydrologic cycle. In the Laurentian Great Lakes, changes in long-term evaporation and precipitation can lead to rapid water level fluctuations in the lakes, as evidenced by unprecedented change in water levels seen in the last two decades. These fluctuations often have an adverse impact on the region's human, environmental, and economic well-being, making accurate long-term water level projections invaluable to regional water resources management planning. Here we use hydrological components from a downscaled climate model (GFDL-CM3/WRF), to obtain future water supplies for the Great Lakes. We then apply a suite of bias correction procedures before propagating these water supplies through a routing model to produce lake water levels. Results using conventional bias correction methods suggest that water levels will decline by several feet in the coming century. However, methods that reflect the seasonal water cycle and explicitly debias individual hydrological components (overlake precipitation, overlake evaporation, runoff) imply that future water levels may be closer to their historical average. This discrepancy between debiased results indicates that water level forecasts are highly influenced by the bias correction method, a source of sensitivity that is commonly overlooked. Debiasing, however, does not remedy misrepresentation of the underlying physical processes in the climate model that produce these biases and contribute uncertainty to the hydrological projections. This uncertainty coupled with the differences in water level forecasts from varying bias correction methods are important for water management and long term planning in the Great Lakes region.

  5. General single phase wellbore flow model

    Energy Technology Data Exchange (ETDEWEB)

    Ouyang, Liang-Biao; Arbabi, S.; Aziz, K.

    1997-02-05

    A general wellbore flow model, which incorporates not only frictional, accelerational and gravitational pressure drops, but also the pressure drop caused by inflow, is presented in this report. The new wellbore model is readily applicable to any wellbore perforation patterns and well completions, and can be easily incorporated in reservoir simulators or analytical reservoir inflow models. Three dimensionless numbers, the accelerational to frictional pressure gradient ratio R{sub af}, the gravitational to frictional pressure gradient ratio R{sub gf}, and the inflow-directional to accelerational pressure gradient ratio R{sub da}, have been introduced to quantitatively describe the relative importance of different pressure gradient components. For fluid flow in a production well, it is expected that there may exist up to three different regions of the wellbore: the laminar flow region, the partially-developed turbulent flow region, and the fully-developed turbulent flow region. The laminar flow region is located near the well toe, the partially-turbulent flow region lies in the middle of the wellbore, while the fully-developed turbulent flow region is at the downstream end or the heel of the wellbore. Length of each region depends on fluid properties, wellbore geometry and flow rate. As the distance from the well toe increases, flow rate in the wellbore increases and the ratios R{sub af} and R{sub da} decrease. Consequently accelerational and inflow-directional pressure drops have the greatest impact in the toe region of the wellbore. Near the well heel the local wellbore flow rate becomes large and close to the total well production rate, here R{sub af} and R{sub da} are small, therefore, both the accelerational and inflow-directional pressure drops can be neglected.

  6. A single center's experience with pacemaker implantation after the Cox maze procedure for atrial fibrillation.

    Science.gov (United States)

    Ad, Niv; Holmes, Sari D; Ali, Rabia; Pritchard, Graciela; Lamont, Deborah

    2017-07-01

    The Cox maze procedure (CM) is safe and effective for all atrial fibrillation (AF) types. A recent randomized trial found alarming rates of pacemaker implantation (PMI) during hospitalization after CM. The purpose of this study was to assess the rate of PMI and its impact on outcomes after CM. Incidence of PMI was captured for all CM patients (2005-2015; N = 739). Data were collected prospectively. Multivariable logistic regression was conducted to determine risk factors for PMI. Propensity score matching was conducted between concomitant CM patients and patients without surgical ablation since 2011. Fifty-two patients (7.0%) had in-hospital PMI after CM. Most common primary indication for PMI was sick sinus syndrome (67%), followed by complete heart block (23%) and sinus bradycardia (10%). The only risk factor for in-hospital PMI was type of procedure (P = .020). Patients with multiple valve procedures were at greatest risk (P = .004-.035). STS-defined perioperative outcomes were similar for patients with and without in-hospital PMI. Sinus rhythm off antiarrhythmic drugs were similar by PMI. After propensity score matching (n = 180 per group), in-hospital PMI was similar in CM patients and those without surgical ablation (5% vs 4%, P = .609). This study demonstrated lower incidence of PMI after CM procedures than recently reported. When indicated, PMI was not associated with increased short- or long-term morbidity or inferior freedom from atrial arrhythmia. Efforts to increase surgeon training with the CM procedure and postoperative management awareness are warranted to improve rhythm outcome and minimize adverse events and PMI. Copyright © 2017 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

  7. Exclusion of fluoroscopy use in catheter ablation procedures: six years of experience at a single center.

    Science.gov (United States)

    Fernández-Gómez, Juan M; Moriña-Vázquez, Pablo; Morales, Elena Del Rio; Venegas-Gamero, José; Barba-Pichardo, Rafael; Carranza, Manuel Herrera

    2014-06-01

    Nonfluoroscopic mapping systems have demonstrated significant reduction of radiation exposure in radiofrequency (RF) catheter ablation procedures. However, their use as only imaging guide is still limited. To evaluate the usefulness of a completely nonfluoroscopic approach to catheter ablation of supraventricular arrhythmias using the Ensite-NavX™ electroanatomical navigation system. During 6 years, all consecutive patients referred for RF catheter ablation of regular supraventricular tachycardia (SVT) were admitted for a "zero-fluoroscopy" approach and studied prospectively. The only exclusion criterion was the need to perform a transseptal puncture. A total of 340 procedures were performed on 328 patients (179 men, age 55.7 ± 18.6 years). One hundred fifty-three patients had typical atrial flutter (AFL), 146 had AV nodal reentrant tachycardia (AVNRT), 35 had AV reciprocating tachycardia (AVRT), 4 patients had incisional atrial flutter (IAF), and 2 had focal atrial tachycardia (AT). Procedural success was achieved in 337 of the cases (99.1%). In 322 (94.7%), the procedure was completed without any fluoroscopy use. Mean procedure time was 110.5 ± 51.8 minutes. Mean RF application time was 9.8 ± 12.8 minutes and the number of RF lesions was 16.43 ± 15.8. Only 1 major complication related to vascular access was recorded. During follow-up, there were 12 recurrences (3.5%) (8 patients from the AVNRT group, 4 patients from the AP group). RF catheter ablation of SVT with an approach completely guided by the NavX system and without use of fluoroscopy is feasible, safe, and effective. © 2014 Wiley Periodicals, Inc.

  8. Pylorus drainage procedures in thoracoabdominal esophagectomy - a single-center experience and review of the literature.

    Science.gov (United States)

    Fritz, Stefan; Feilhauer, Katharina; Schaudt, André; Killguss, Hansjörg; Esianu, Eduard; Hennig, René; Köninger, Jörg

    2018-03-01

    Pylorotomy and pyloroplasty in thoracoabdominal esophagectomy are routinely performed in many high-volume centers to prevent delayed gastric emptying (DGE) due to truncal vagotomy. Currently, controversy remains regarding the need for these practices. The present study aimed to determine the value and role of pyloric drainage procedures in esophagectomy with gastric replacement. A retrospective review of prospectively collected data was performed for all consecutive patients who underwent thoracoabdominal resection of the esophagus between January 2009 and December 2016 at the Katharinenhospital in Stuttgart, Germany. Clinicopathologic features and surgical outcomes were evaluated with a focus on postoperative nutrition and gastric emptying. The study group included 170 patients who underwent thoracoabdominal esophageal resection with a gastric conduit using the Ivor Lewis approach. The median age of the patients was 64 years. Most patients were male (81%), and most suffered from adenocarcinoma of the esophagus (75%). The median hospital stay was 20 days, and the 30-day hospital death rate was 2.9%. According to the department standard, pylorotomy, pyloroplasty, or other pyloric drainage procedures were not performed in any of the patients. Overall, 28/170 patients showed clinical signs of DGE (16.5%). In the literature, the rate of DGE after thoracoabdominal esophagectomy is reported to be approximately 15%, even with the use of pyloric drainage procedures. This rate is comparable to that reported in the present series in which no pyloric drainage procedures were performed. Therefore, we believe that pyloric drainage procedures may be unwarranted in thoracoabdominal esophagectomy. However, future randomized trials are needed to ultimately confirm this supposition.

  9. Modelling a singly resonant, intracavity ring optical parametric oscillator

    DEFF Research Database (Denmark)

    Buchhave, Preben; Tidemand-Lichtenberg, Peter; Wei, Hou

    2003-01-01

    We study theoretically and experimentally the dynamics of a single-frequency, unidirectional ring laser with an intracavity nonlinear singly resonant OPO-crystal in a coupled resonator. We find for a range of operating conditions good agreement between model results and measurements of the laser...

  10. Homology modelling and bivalent single-chain Fv construction of ...

    Indian Academy of Sciences (India)

    Homology modelling and bivalent single-chain Fv construction of anti-HepG2 single-chain immunoglobulin Fv fragments from a phage display library ... Department of Infectious Diseases, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; Department of ...

  11. A Stepwise Fitting Procedure for automated fitting of Ecopath with Ecosim models

    Science.gov (United States)

    Scott, Erin; Serpetti, Natalia; Steenbeek, Jeroen; Heymans, Johanna Jacomina

    The Stepwise Fitting Procedure automates testing of alternative hypotheses used for fitting Ecopath with Ecosim (EwE) models to observation reference data (Mackinson et al. 2009). The calibration of EwE model predictions to observed data is important to evaluate any model that will be used for ecosystem based management. Thus far, the model fitting procedure in EwE has been carried out manually: a repetitive task involving setting > 1000 specific individual searches to find the statistically 'best fit' model. The novel fitting procedure automates the manual procedure therefore producing accurate results and lets the modeller concentrate on investigating the 'best fit' model for ecological accuracy.

  12. Single particle degrees of freedom in the interacting boson model

    NARCIS (Netherlands)

    Scholten, O.

    1985-01-01

    An overview is given of different aspects of the Interacting Boson Fermion Model, the extension of the interacting Boson Model to odd mass nuclei. The microscopic model for the coupling of single-particle degrees of freedom to the system of bosons is outlined and the interaction between the bosons

  13. Mixture of Regression Models with Single-Index

    OpenAIRE

    Xiang, Sijia; Yao, Weixin

    2016-01-01

    In this article, we propose a class of semiparametric mixture regression models with single-index. We argue that many recently proposed semiparametric/nonparametric mixture regression models can be considered special cases of the proposed model. However, unlike existing semiparametric mixture regression models, the new pro- posed model can easily incorporate multivariate predictors into the nonparametric components. Backfitting estimates and the corresponding algorithms have been proposed for...

  14. Conversion of failed laparoscopic adjustable gastric banding to Roux-en-Y gastric bypass is safe as a single-step procedure

    NARCIS (Netherlands)

    Emous, M.; Apers, J.; Hoff, C.; van Beek, A. P.; Totte, E.

    Several different procedures have been proposed as a revisional procedure for treatment of failed laparoscopic adjustable gastric banding (LAGB). Laparoscopic Roux-en-Y gastric bypass (LRYGB) has been advocated as the procedure of choice for revision. In this study, we compare the single- and

  15. Effect of race on the timing of the Glenn and Fontan procedures for single-ventricle congenital heart disease.

    Science.gov (United States)

    Ingaramo, Oscar A; Khemani, Robinder G; Markovitz, Barry P; Epstein, David

    2012-03-01

    Disparities in health care have been documented between different racial groups in the United States. We hypothesize that there will be racial variance in the timing of the Glenn and Fontan procedures for children with single-ventricle physiology. We performed a retrospective review of a national pediatric intensive care unit database (Virtual PICU Performance System, LLC). Children with hypoplastic left heart syndrome, tricuspid atresia, and common ventricle, admitted from January 2006 to July 2008, were included. Data included race, weight, age, medical length of stay, Paediatric Index of Mortality 2 score, and survival. None. There were 423 patients from 29 hospitals. The study population was 7.6% black, 13.0% Hispanic, 59.8% white, 9.2% "other," and 11.6% had missing racial/ethnic information. Diagnoses included 255 patients with hypoplastic left heart syndrome, 91 with tricuspid atresia, and 77 with common ventricle. The median age for the Glenn procedure (n = 205) was 5.5 months (interquartile range, 4.6-7.0 months) and 39.7 months (interquartile range, 32.4-50.6 months) for the Fontan procedure (n = 218). There was no difference between the median age at the time of the Glenn or Fontan procedures between the different racial/ethnic groups (p = .65 and p = .16, respectively). The medical length of intensive care unit stay for patients receiving the Glenn and Fontan procedures was 3.7 days (interquartile range, 1.9-6.1 days) and 3.7 days (interquartile range, 1.9-6.8 days), respectively. There were no differences in medical length of intensive care unit stay for the Glenn procedure between the different racial/ethnic groups (p = .21). Hispanic patients had a longer medical length of intensive care unit stay (6.3 days; interquartile range, 3.1-9.9 days) than white patients (2.9 days; interquartile range, 1.8-5.3 days) for the Fontan procedure (p = .008). The timing of single-ventricle palliative procedures was not affected by race/ethnicity.

  16. Procedure for identifying models for the heat dynamics of buildings

    DEFF Research Database (Denmark)

    Bacher, Peder; Madsen, Henrik

    This report describes a new method for obtaining detailed information about the heat dynamics of a building using frequent reading of the heat consumption. Such a procedure is considered to be of uttermost importance as a key procedure for using readings from smart meters, which is expected...

  17. Procedural Sensitivities of Effect Sizes for Single-Case Designs with Directly Observed Behavioral Outcome Measures

    Science.gov (United States)

    Pustejovsky, James E.

    2018-01-01

    A wide variety of effect size indices have been proposed for quantifying the magnitude of treatment effects in single-case designs. Commonly used measures include parametric indices such as the standardized mean difference, as well as non-overlap measures such as the percentage of non-overlapping data, improvement rate difference, and non-overlap…

  18. Global Asymptotic Stability for Discrete Single Species Population Models

    Directory of Open Access Journals (Sweden)

    A. Bilgin

    2017-01-01

    Full Text Available We present some basic discrete models in populations dynamics of single species with several age classes. Starting with the basic Beverton-Holt model that describes the change of single species we discuss its basic properties such as a convergence of all solutions to the equilibrium, oscillation of solutions about the equilibrium solutions, Allee’s effect, and Jillson’s effect. We consider the effect of the constant and periodic immigration and emigration on the global properties of Beverton-Holt model. We also consider the effect of the periodic environment on the global properties of Beverton-Holt model.

  19. A Tractable Model of the LTE Access Reservation Procedure for Machine-Type Communications

    DEFF Research Database (Denmark)

    Nielsen, Jimmy Jessen; Min Kim, Dong; Madueño, Germán Corrales

    2015-01-01

    A canonical scenario in Machine-Type Communications (MTC) is the one featuring a large number of devices, each of them with sporadic traffic. Hence, the number of served devices in a single LTE cell is not determined by the available aggregate rate, but rather by the limitations of the LTE access...... reservation protocol. Specifically, the limited number of contention preambles and the limited amount of uplink grants per random access response are crucial to consider when dimensioning LTE networks for MTC. We propose a low-complexity model that encompasses these two limitations and allows us to evaluate...... on the preamble collisions. A comparison with the simulated LTE access reservation procedure that follows the 3GPP specifications, confirms that our model provides an accurate estimation of the system outage event and the number of supported MTC devices....

  20. Variance Function Partially Linear Single-Index Models1.

    Science.gov (United States)

    Lian, Heng; Liang, Hua; Carroll, Raymond J

    2015-01-01

    We consider heteroscedastic regression models where the mean function is a partially linear single index model and the variance function depends upon a generalized partially linear single index model. We do not insist that the variance function depend only upon the mean function, as happens in the classical generalized partially linear single index model. We develop efficient and practical estimation methods for the variance function and for the mean function. Asymptotic theory for the parametric and nonparametric parts of the model is developed. Simulations illustrate the results. An empirical example involving ozone levels is used to further illustrate the results, and is shown to be a case where the variance function does not depend upon the mean function.

  1. An introduction to modeling longitudinal data with generalized additive models: applications to single-case designs.

    Science.gov (United States)

    Sullivan, Kristynn J; Shadish, William R; Steiner, Peter M

    2015-03-01

    Single-case designs (SCDs) are short time series that assess intervention effects by measuring units repeatedly over time in both the presence and absence of treatment. This article introduces a statistical technique for analyzing SCD data that has not been much used in psychological and educational research: generalized additive models (GAMs). In parametric regression, the researcher must choose a functional form to impose on the data, for example, that trend over time is linear. GAMs reverse this process by letting the data inform the choice of functional form. In this article we review the problem that trend poses in SCDs, discuss how current SCD analytic methods approach trend, describe GAMs as a possible solution, suggest a GAM model testing procedure for examining the presence of trend in SCDs, present a small simulation to show the statistical properties of GAMs, and illustrate the procedure on 3 examples of different lengths. Results suggest that GAMs may be very useful both as a form of sensitivity analysis for checking the plausibility of assumptions about trend and as a primary data analysis strategy for testing treatment effects. We conclude with a discussion of some problems with GAMs and some future directions for research on the application of GAMs to SCDs. (c) 2015 APA, all rights reserved).

  2. Single-port, single-operator-light endoscopic robot-assisted laparoscopic urology: pilot study in a pig model.

    Science.gov (United States)

    Crouzet, Sebastien; Haber, Georges-Pascal; White, Wesley M; Kamoi, Kazumi; Goel, Raj K; Kaouk, Jihad H

    2010-03-01

    To present our initial operative experience in which single-port-light endoscopic robot-assisted reconstructive and extirpative urological surgery was performed by one surgeon, using a pig model. This pilot study was conducted in male farm pigs to determine the feasibility and safety of single-port, single-surgeon urological surgery. All pigs had a general anaesthetic and were placed in the flank position. A 2-cm umbilical incision was made, through which a single port was placed and pneumoperitoneum obtained. An operative laparoscope was introduced and securely held using a novel low-profile robot under foot and/or voice control. Using articulating instruments, each pig had bilateral reconstructive and extirpative renal surgery. Salient intraoperative and postmortem data were recorded. Results were analysed statistically to determine if outcomes improved with surgeon experience. Five male farm pigs underwent bilateral partial nephrectomy and bilateral pyeloplasty before a completion bilateral radical nephrectomy. There were no intraoperative complications and there was no need for additional ports to be placed. The mean (range) operative duration for partial nephrectomy, pyeloplasty, and nephrectomy were 120 (100-150), 110 (95-130) and 20 (15-30) min, respectively. The mean (range) estimated blood loss for all procedures was 240 (200-280) mL. The preparation time decreased with increasing number of cases (P = 0.002). The combination of a single-port, a robotic endoscope holder and articulated instruments operated by one surgeon is feasible. With a single-port access, the robot allows more room to the surgeon than an assistant.

  3. Planning Single-Event Nutrition Education: A New Model

    Science.gov (United States)

    Brown, Lora Beth

    2011-01-01

    A theoretical model for planning single-event nutrition education contrasts a Practical, Foods, and Positive (PFP) emphasis to an Abstract, Nutrient, and Negative (ANN) focus on nutrition topics. Use of this model makes messages more appealing to consumers and may increase the likelihood that people will apply the nutrition information in their…

  4. Complicated Crown-Root Fracture Treated Using Reattachment Procedure: A Single Visit Technique

    Directory of Open Access Journals (Sweden)

    Akhil Rajput

    2011-01-01

    Full Text Available Complicated crown-root fracture of maxillary central and lateral incisors is common in case of severe trauma or sports-related injury. It happens because of their anterior positioning in oral cavity and protrusive eruptive pattern. On their first dental visit, these patients are in pain and need emergency care. Because of impaired function, esthetics, and phonetics, such patients are quite apprehensive during their emergency visit. Successful pain management with immediate restoration of function, esthetics and phonetics should be the prime objective while handling such cases. This paper describes immediate treatment of oblique crown root fracture of maxillary right lateral incisor with reattachment procedure using light transmitting fiber post. After two and half years, the reattached fragment still has satisfying esthetics and excellent function.

  5. Spatial and frequency domain ring source models for the single muscle fiber action potential

    DEFF Research Database (Denmark)

    Henneberg, Kaj-åge; R., Plonsey

    1994-01-01

    In the paper, single-fibre models for the extracellular action potential are developed that will allow the potential to the evaluated at an arbitrary field point in the extracellular space. Fourier-domain models are restricted in that they evaluate potentials at equidistant points along a line...... parallel to the fibre axis. Consequently, they cannot easily evaluate the potential at the boundary nodes of a boundary-element electrode model. The Fourier-domain models employ axial-symmetric ring source models, and thereby provide higher accuracy that the line source model, where the source is lumped...... including anisotropy show that the spatial models require extreme care in the integration procedure owing to the singularity in the weighting functions. With adequate sampling, the spatial models can evaluate extracellular potentials with high accuracy....

  6. Single crystal plasticity by modeling dislocation density rate behavior

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Benjamin L [Los Alamos National Laboratory; Bronkhorst, Curt [Los Alamos National Laboratory; Beyerlein, Irene [Los Alamos National Laboratory; Cerreta, E. K. [Los Alamos National Laboratory; Dennis-Koller, Darcie [Los Alamos National Laboratory

    2010-12-23

    The goal of this work is to formulate a constitutive model for the deformation of metals over a wide range of strain rates. Damage and failure of materials frequently occurs at a variety of deformation rates within the same sample. The present state of the art in single crystal constitutive models relies on thermally-activated models which are believed to become less reliable for problems exceeding strain rates of 10{sup 4} s{sup -1}. This talk presents work in which we extend the applicability of the single crystal model to the strain rate region where dislocation drag is believed to dominate. The elastic model includes effects from volumetric change and pressure sensitive moduli. The plastic model transitions from the low-rate thermally-activated regime to the high-rate drag dominated regime. The direct use of dislocation density as a state parameter gives a measurable physical mechanism to strain hardening. Dislocation densities are separated according to type and given a systematic set of interactions rates adaptable by type. The form of the constitutive model is motivated by previously published dislocation dynamics work which articulated important behaviors unique to high-rate response in fcc systems. The proposed material model incorporates thermal coupling. The hardening model tracks the varying dislocation population with respect to each slip plane and computes the slip resistance based on those values. Comparisons can be made between the responses of single crystals and polycrystals at a variety of strain rates. The material model is fit to copper.

  7. Generation of normative pediatric skull models for use in cranial vault remodeling procedures.

    Science.gov (United States)

    Saber, Nikoo R; Phillips, John; Looi, Thomas; Usmani, Zoha; Burge, Jonathan; Drake, James; Kim, Peter C W

    2012-03-01

    While the goal of craniofacial reconstruction surgery is to restore the cranial head shape as much towards normal as possible, for the individual patient, there is, in fact, no normal three-dimensional (3D) model to act as a guide. In this project, we generated a library of normative pediatric skulls from which a guiding template could be fabricated for a more standardized, objective and precise correction of craniosynostosis. Computed tomography data from 103 normal subjects aged 8-12 months were compiled and a 3D computational model of the skull was generated for each subject. The models were mathematically registered to a baseline model for each month of age within this range and then averaged, resulting in a single 3D point cloud. An external cranial surface was subsequently passed through the point cloud and its shape and size customized to fit the head circumference of individual patients. The resultant fabricated skull models provide a novel and applicable tool for a detailed, quantitative comparison between the normative and patient skulls for preoperative planning and practice for a variety of craniofacial procedures including vault remodeling. Additionally, it was possible to extract the suprafrontal orbit anatomy from the normative model and fabricate a bandeau template to guide intraoperative reshaping. Normative head shapes for pediatric patients have wide application for craniofacial surgery including planning, practice, standarized operative repair, and standardized measurement and reporting of outcomes.

  8. A Numerical Comparison of Three Procedures Used in Failure Model Discrimination

    Directory of Open Access Journals (Sweden)

    Samir Kamel Ashour

    2014-05-01

    Full Text Available Three different selection procedures namely RML, S and F-procedure are reviewed with application to exponential, Weibull, Pareto, and Finite range models. Some inacurate results were discovered in the article of Pandy et al. (1991, it will be illustrated and modified. A simulation study is developed to numerically compare between the three procedures by obtaining the probability of correct selection

  9. A Comparison of Exposure Control Procedures in CATs Using the 3PL Model

    Science.gov (United States)

    Leroux, Audrey J.; Lopez, Myriam; Hembry, Ian; Dodd, Barbara G.

    2013-01-01

    This study compares the progressive-restricted standard error (PR-SE) exposure control procedure to three commonly used procedures in computerized adaptive testing, the randomesque, Sympson-Hetter (SH), and no exposure control methods. The performance of these four procedures is evaluated using the three-parameter logistic model under the…

  10. Modeling of calcination of single kaolinitic clay particle

    DEFF Research Database (Denmark)

    Gebremariam, Abraham Teklay; Yin, Chungen; Rosendahl, Lasse

    The present work aims at modeling of the calcination (dehydroxylation) process of clay particles, specifically kaolinite, and its thermal transformation. For such purpose, 1D single particle calcination model was developed based on the concept of shrinking core model to assess the dehydroxylation...... distribution within the clay particle and simultaneous density changes due to the reaction kinetics. Accordingly, a particular residence time was noticed as a point where kaolinitic clay particles attain optimum conversion to metakaolinite which is pozzolanic....

  11. Some technological procedures and equipment for hydrothermal growth of single crystals

    International Nuclear Information System (INIS)

    Popolitov, V.I.; Lobachev, A.N.; Shapiro, A.Y.

    1986-01-01

    The authors have designed, installed and tested a quartz reactor with 200 cm 3 volume in order to directly observe the process of dissolution of solid ingredients, and the synthesis and seeded growth of crystals. The reactor is illustrated. Two C-A thermocouples were used during the experiments to measure the temperature distribution along the outer wall of the reactor in the upper and lower zone. A method is described that was used to grow pyro-and feroelectric single crystals from the ABO 4 group (A-Sb 3+ , Bi 3+ ; B-Nb 5+ , Ta 5+ , Sb 5+ ), and in particular SbSbO 4 , SbNbO 4 , and SbTaO 4

  12. Procedure to Determine Coefficients for the Sandia Array Performance Model (SAPM)

    Energy Technology Data Exchange (ETDEWEB)

    King, Bruce Hardison; Hansen, Clifford; Riley, Daniel; Robinson, Charles David; Pratt, Larry

    2016-06-01

    The Sandia Array Performance Model (SAPM), a semi-empirical model for predicting PV system power, has been in use for more than a decade. While several studies have presented comparisons of measurements and analysis results among laboratories, detailed procedures for determining model coefficients have not yet been published. Independent test laboratories must develop in-house procedures to determine SAPM coefficients, which contributes to uncertainty in the resulting models. Here we present a standard procedure for calibrating the SAPM using outdoor electrical and meteorological measurements. Analysis procedures are illustrated with data measured outdoors for a 36-cell silicon photovoltaic module.

  13. [Single procedure treatment of complex nephrolithiasis: about a modern series of anatrophic nephrolithotomy].

    Science.gov (United States)

    Lunardi, P; Timsit, M O; Roumiguie, M; Dariane, C; N'Guyen, K; Beauval, J B; Leroux, S

    2015-02-01

    Advances in endourology have significantly reduced indications of open surgery in the treatment of staghorn calculi. However, in our experience, open surgery is still the treatment of choice in some cases. This study presents the results of a series of selected patients and discusses the results in terms of efficacy and morbidity. A cohort of 26 patients underwent anatrophic nephrolithotomy by lombotomy to treat a complex staghorn calculus. The mean stone size was 68,5mm, 70% were complete staghorn calculi. The operative time was 100minutes. Blood loss was 225mL, with a postoperative transfusion rate of 15.4%. The hospital stay was 8.4 days. The stone free rate following the procedure was 92%. The creatinine clearance (MDRD) at 3 months was improved from 5.9mL/min/m(2) on average over the entire series. There are clearly still indications for open surgery in staghorn stones management, with good results in this contemporary series on both stone removal and nephronic preservation. Yet, it appears that this technique is no longer taught. 5. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  14. A single extraction and HPLC procedure for simultaneous analysis of phytosterols, tocopherols and lutein in soybeans.

    Science.gov (United States)

    Slavin, Margaret; Yu, Liangli Lucy

    2012-12-15

    A saponification/extraction procedure and high performance liquid chromatography (HPLC) analysis method were developed and validated for simultaneous analysis of phytosterols, tocopherols and lutein (a carotenoid) in soybeans. Separation was achieved on a phenyl column with a ternary, isocratic solvent system of acetonitrile, methanol and water (48:22.5:29.5, v/v/v). Evaporative light scattering detection (ELSD) was used to quantify β-sitosterol, stigmasterol, campesterol, and α-, δ- and γ-tocopherols, while lutein was quantified with visible light absorption at 450 nm. Peak identification was verified by retention times and spikes with external standards. Standard curves were constructed (R(2)>0.99) to allow for sample quantification. Recovery of the saponification and extraction was demonstrated via analysis of spiked samples. Also, the accuracy of results of four soybeans using the described saponification and HPLC analytical method was validated against existing methods. This method offers a more efficient alternative to individual methods for quantifying lutein, tocopherols and sterols in soybeans. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. The feasibility and safety of single-incision totally extraperitoneal inguinal hernia repair after previous lower abdominal surgery: 350 procedures at a single center.

    Science.gov (United States)

    Wakasugi, Masaki; Suzuki, Yozo; Tei, Mitsuyoshi; Anno, Kana; Mikami, Tsubasa; Tsukada, Ryo; Koh, Masahiro; Furukawa, Kenta; Masuzawa, Toru; Kishi, Kentaro; Tanemura, Masahiro; Akamatsu, Hiroki

    2017-03-01

    To evaluate the feasibility and safety of single-incision laparoscopic surgery for totally extraperitoneal inguinal hernia repair (SILS-TEP) with previous lower abdominal surgery (PLAS). A retrospective analysis of 350 patients undergoing SILS-TEP for a primary inguinal hernia from January 2012 to December 2015 at Osaka Police Hospital was performed, and the outcomes of the patients with and without PLAS were compared. SILS-TEP was performed in 84 patients with PLAS and 266 patients without PLAS. Appendectomy was the most common previous operative procedure. There were more patients with an ASA score of ≥3 in the PLAS group than in the control group (p < 0.05). The mean operative time, and the rates of conversion and postoperative complications were comparable between the two groups. There were no cases of recurrence in either group. SILS-TEP could be safely performed in patients with PLAS and achieved better cosmetic outcomes than conventional laparoscopic surgery.

  16. A Proposal for a Procedural Terrain Modelling Framework

    NARCIS (Netherlands)

    Smelik, R.M.; T. Tutenel, T.; Kraker, K.J. de; Bidarra, R.

    2008-01-01

    Manual game content creation is an increasingly laborious task; with each advance in graphics hardware, a higher level of fidelity and detail is achievable and, therefore, expected. Although numerous automatic (e.g. procedural) content generation algorithms and techniques have been developed over

  17. A declarative approach to procedural modeling of virtual worlds

    NARCIS (Netherlands)

    Smelik, R.M.; Tutenel, T.; Kraker, K.J.de; Bidarra, R.

    2011-01-01

    With the ever increasing costs of manual content creation for virtual worlds, the potential of creating it automatically becomes too attractive to ignore. However, for most designers, traditional procedural content generation methods are complex and unintuitive to use, hard to control, and generated

  18. A Survey of Procedural Methods for Terrain Modelling

    NARCIS (Netherlands)

    Smelik, R.M.; Kraker, J.K. de; Groenewegen, S.A.; Tutenel, T.; Bidarra, R.

    2009-01-01

    Procedural methods are a promising but underused alternative to manual content creation. Commonly heard drawbacks are the randomness of and the lack of control over the output and the absence of integrated solutions, although more recent publications increasingly address these issues. This paper

  19. Robotic-assisted transperitoneal aortic lymphadenectomy as part of staging procedure for gynaecological malignancies: single institution experience.

    Science.gov (United States)

    Zanagnolo, V; Rollo, D; Tomaselli, T; Rosenberg, P G; Bocciolone, L; Landoni, F; Aletti, G; Peiretti, M; Sanguineti, F; Maggioni, A

    2013-01-01

    Introduction. This study was designed to confirm the feasibility and safety of robotic-assisted transperitoneal aortic lymphadenectomy as part of staging procedure for gynecologic malignancies. Methods. Chart review of 51 patients who had undergone robotic staging with aortic lymphadenectomy for different gynaecologic malignancies was performed. Results. The primary diagnosis was as follows: 6 cases of endometrial cancer, 31 epithelial ovarian cancer, 9 nonepithelial ovarian cancer, 4 tubal cancer, and 1 cervical cancer. Median BMI was 23 kg/m(2). Except for a single case of aortic lymphadenectomy only, both aortic and pelvic lymphadenectomies were performed at the time of the staging procedure. All the para-aortic lymphadenectomies were carried out to the level of the renal veinl but 6 cases were carried out to the level of the inferior mesenteric artery. Hysterectomy was performed in 24 patiens (47%). There was no conversion to LPT. The median console time was 285 (range 195-402) with a significant difference between patients who underwent hysterectomy and those who did not. The median estimated blood loss was 50 mL (range 20-200). The mean number of removed nodes was 29 ± 9.6. The mean number of pelvic nodes was 15 ± 7.6, whereas the mean number of para-aortic nodes was 14 ± 6.6. Conclusions. Robotic transperitoneal infrarenal aortic lymphadenectomy as part of staging procedure is feasible and can be safely performed. Additional trocars are needed when pelvic surgery is also performed.

  20. Evaluating procedural modelling for 3D models of informal settlements in urban design activities

    Directory of Open Access Journals (Sweden)

    Victoria Rautenbach

    2015-11-01

    Full Text Available Three-dimensional (3D modelling and visualisation is one of the fastest growing application fields in geographic information science. 3D city models are being researched extensively for a variety of purposes and in various domains, including urban design, disaster management, education and computer gaming. These models typically depict urban business districts (downtown or suburban residential areas. Despite informal settlements being a prevailing feature of many cities in developing countries, 3D models of informal settlements are virtually non-existent. 3D models of informal settlements could be useful in various ways, e.g. to gather information about the current environment in the informal settlements, to design upgrades, to communicate these and to educate inhabitants about environmental challenges. In this article, we described the development of a 3D model of the Slovo Park informal settlement in the City of Johannesburg Metropolitan Municipality, South Africa. Instead of using time-consuming traditional manual methods, we followed the procedural modelling technique. Visualisation characteristics of 3D models of informal settlements were described and the importance of each characteristic in urban design activities for informal settlement upgrades was assessed. Next, the visualisation characteristics of the Slovo Park model were evaluated. The results of the evaluation showed that the 3D model produced by the procedural modelling technique is suitable for urban design activities in informal settlements. The visualisation characteristics and their assessment are also useful as guidelines for developing 3D models of informal settlements. In future, we plan to empirically test the use of such 3D models in urban design projects in informal settlements.

  1. Comparison of In-Flight Measured and Computed Aeroelastic Damping: Modal Identification Procedures and Modeling Approaches

    Directory of Open Access Journals (Sweden)

    Roberto da Cunha Follador

    2016-04-01

    Full Text Available The Operational Modal Analysis technique is a methodology very often applied for the identification of dynamic systems when the input signal is unknown. The applied methodology is based on a technique to estimate the Frequency Response Functions and extract the modal parameters using only the structural dynamic response data, without assuming the knowledge of the excitation forces. Such approach is an adequate way for measuring the aircraft aeroelastic response due to random input, like atmospheric turbulence. The in-flight structural response has been measured by accelerometers distributed along the aircraft wings, fuselage and empennages. The Enhanced Frequency Domain Decomposition technique was chosen to identify the airframe dynamic parameters. This technique is based on the hypothesis that the system is randomly excited with a broadband spectrum with almost constant power spectral density. The system identification procedure is based on the Single Value Decomposition of the power spectral densities of system output signals, estimated by the usual Fast Fourier Transform method. This procedure has been applied to different flight conditions to evaluate the modal parameters and the aeroelastic stability trends of the airframe under investigation. The experimental results obtained by this methodology were compared with the predicted results supplied by aeroelastic numerical models in order to check the consistency of the proposed output-only methodology. The objective of this paper is to compare in-flight measured aeroelastic damping against the corresponding parameters computed from numerical aeroelastic models. Different aerodynamic modeling approaches should be investigated such as the use of source panel body models, cruciform and flat plate projection. As a result of this investigation it is expected the choice of the better aeroelastic modeling and Operational Modal Analysis techniques to be included in a standard aeroelastic

  2. A bespoke single-band Hubbard model material

    Science.gov (United States)

    Griffin, S. M.; Staar, P.; Schulthess, T. C.; Troyer, M.; Spaldin, N. A.

    2016-02-01

    The Hubbard model, which augments independent-electron band theory with a single parameter to describe electron-electron correlations, is widely regarded to be the "standard model" of condensed-matter physics. The model has been remarkably successful at addressing a range of correlation phenomena in solids, but it neglects many behaviors that occur in real materials, such as phonons, long-range interactions, and, in its simplest form, multiorbital effects. Here, we use ab initio electronic structure methods to design a material whose Hamiltonian matches as closely as possible that of the single-band Hubbard model. Our motivation is to compare the measured properties of our new material to those predicted by reliable theoretical solutions of the Hubbard model to determine the relevance of the model in the description of real materials. After identifying an appropriate crystal class and several appropriate chemistries, we use density-functional theory and dynamical mean-field theory to screen for the desired electronic band structure and metal-insulator transition. We then explore the most promising candidates for structural stability and suitability for doping, and we propose specific materials for subsequent synthesis. Finally, we identify a regime—that should manifest in our bespoke material—in which the single-band Hubbard model on a triangular lattice exhibits exotic d -wave superconductivity.

  3. Proposed core competencies and empirical validation procedure in competency modeling: confirmation and classification

    Directory of Open Access Journals (Sweden)

    Anna Katarzyna Baczynska

    2016-03-01

    Full Text Available Competency models provide insight into key skills which are common to many positions in an organization. Moreover, there is a range of competencies that is used by many companies. Researchers have developed core competency terminology to underline their cross-organizational value. The article presents a theoretical model of core competencies consisting of two main higher-order competencies called performance and entrepreneurship. Each of them consists of three elements: the performance competency includes cooperation, organization of work and goal orientation, while entrepreneurship includes innovativeness, calculated risk-taking and pro-activeness. However, there is lack of empirical validation of competency concepts in organizations and this would seem crucial for obtaining reliable results from organizational research. We propose a two-step empirical validation procedure: 1 confirmation factor analysis, and 2 classification of employees. The sample consisted of 636 respondents (M = 44.5; SD = 15.1. Participants were administered a questionnaire developed for the study purpose. The reliability, measured by Cronbach’s alpha, ranged from .60 to .83 for six scales. Next, we tested the model using a confirmatory factor analysis. The two separate, single models of performance and entrepreneurial orientations fit quite well to the data, while a complex model based on the two single concepts needs further research. In the classification of employees based on the two higher order competencies we obtained four main groups of employees. Their profiles relate to those found in the literature, including so-called niche finders and top performers. Some proposal for organizations is discussed.

  4. Robust and efficient solution procedures for association models

    DEFF Research Database (Denmark)

    Michelsen, Michael Locht

    2006-01-01

    Equations of state that incorporate the Wertheim association expression are more difficult to apply than conventional pressure explicit equations, because the association term is implicit and requires solution for an internal set of composition variables. In this work, we analyze the convergence ...... behavior of different solution methods and demonstrate how a simple and efficient, yet globally convergent, procedure for the solution of the equation of state can be formulated....

  5. Model tests on single piles in soft clay

    Energy Technology Data Exchange (ETDEWEB)

    Pan, J.L. [Durham Univ., Durham, (United Kingdom). School of Engineering; Goh, A.T.C.; Wong, K.S.; Teh, C.I. [Nanyang Technological Univ., (Singapore). Geotechnical Research Centre

    2000-08-04

    The behaviour of single stainless steel piles subjected to lateral soft clay soil movement was investigated in laboratory model tests in an effort to determine the ultimate soil pressure acting along the pile shaft. A custom designed apparatus was manufactured and calibrated for the test which measured the limiting soil pressures acting along the model pile shaft. The ultimate soil pressure was determined based on the maximum value of this measurement. The results show that the ultimate soil pressure for single passive piles was about 10 times the undrained shear strength, and the magnitude of the soil translation needed to fully mobilize the ultimate soil pressure on the single passive piles was about half the pile width. Further experimental study is needed to examine the effects of the pile end fixity, flexibility and shape and to confirm the effects of sample size and the disturbance due to soil sample preparation. 17 refs., 10 figs.

  6. On the Predictiveness of Single-Field Inflationary Models

    CERN Document Server

    Burgess, C.P.; Trott, Michael

    2014-01-01

    We re-examine the predictiveness of single-field inflationary models and discuss how an unknown UV completion can complicate determining inflationary model parameters from observations, even from precision measurements. Besides the usual naturalness issues associated with having a shallow inflationary potential, we describe another issue for inflation, namely, unknown UV physics modifies the running of Standard Model (SM) parameters and thereby introduces uncertainty into the potential inflationary predictions. We illustrate this point using the minimal Higgs Inflationary scenario, which is arguably the most predictive single-field model on the market, because its predictions for $A_s$, $r$ and $n_s$ are made using only one new free parameter beyond those measured in particle physics experiments, and run up to the inflationary regime. We find that this issue can already have observable effects. At the same time, this UV-parameter dependence in the Renormalization Group allows Higgs Inflation to occur (in prin...

  7. Single-particle spectral density of the Hubbard model

    NARCIS (Netherlands)

    Mehlig, B.; Eskes, H.; Hayn, R.; Meinders, M.B.J.

    1995-01-01

    We calculate the single-particle spectral function for the Hubbard model within the framework of a projection technique equivalent to the two-pole approximation. We show that the two-pole approximation can be well understood as an average characterization of the upper and the lower Hubbard bands,

  8. SINGLE-PARTICLE SPECTRAL DENSITY OF THE HUBBARD-MODEL

    NARCIS (Netherlands)

    MEHLIG, B; ESKES, H; HAYN, R; MEINDERS, MBJ

    1995-01-01

    We calculate the single-particle spectral function for the Hubbard model within the framework of a projection technique equivalent to the two-pole approximation. We show that the two-pole approximation can be well understood as an average characterization of the upper and the lower Hubbard bands,

  9. A single product perishing inventory model with demand interaction ...

    African Journals Online (AJOL)

    The paper describes a single perishing product inventory model in which items deteriorate in two phases and then perish. An independent demand takes place at constant rates for items in both phases. A demand for an item in Phase I not satisfied may be satisfied by an item in Phase II, based on a probability measure.

  10. Effective single scattering albedo estimation using regional climate model

    CSIR Research Space (South Africa)

    Tesfaye, M

    2011-09-01

    Full Text Available In this study, by modifying the optical parameterization of Regional Climate model (RegCM), the authors have computed and compared the Effective Single-Scattering Albedo (ESSA) which is a representative of VIS spectral region. The arid, semi...

  11. Interpolation solution of the single-impurity Anderson model

    International Nuclear Information System (INIS)

    Kuzemsky, A.L.

    1990-10-01

    The dynamical properties of the single-impurity Anderson model (SIAM) is studied using a novel Irreducible Green's Function method (IGF). The new solution for one-particle GF interpolating between the strong and weak correlation limits is obtained. The unified concept of relevant mean-field renormalizations is indispensable for strong correlation limit. (author). 21 refs

  12. Ankle Block vs Single-Shot Popliteal Fossa Block as Primary Anesthesia for Forefoot Operative Procedures: Prospective, Randomized Comparison.

    Science.gov (United States)

    Schipper, Oliver N; Hunt, Kenneth J; Anderson, Robert B; Davis, W Hodges; Jones, Carroll P; Cohen, Bruce E

    2017-11-01

    Postoperative pain is often difficult to control with oral medications, requiring large doses of opioid analgesia. Regional anesthesia may be used for primary anesthesia, reducing the need for general anesthetic and postoperative pain medication requirements in the immediate postoperative period. The purpose of this study was to compare the analgesic effects of an ankle block (AB) to a single-shot popliteal fossa block (PFB) for patients undergoing orthopedic forefoot procedures. All patients having elective outpatient orthopedic forefoot procedures were invited to participate in the study. Patients were prospectively randomized to receive either an ultrasound-guided AB or PFB by a board-certified anesthesiologist prior to their procedure. Intraoperative conversion to general anesthesia and postanesthesia care unit (PACU) opioid requirements were recorded. Postoperative pain was assessed using the visual analog scale (VAS) at regular time intervals until 8 am on postoperative day (POD) 2. Patients rated the effectiveness of the block on a 1 to 5 scale, with 5 being very effective. A total of 167 patients participated in the study with 88 patients (53%) receiving an AB and 79 (47%) receiving a single-shot PFB. There was no significant difference in the rate of conversion to general anesthesia between the 2 groups (13.6% [12/88] AB vs 12.7% [10/79] PFB). PACU morphine requirements and doses were significantly reduced in the PFB group ( P = .004) when compared to the AB group. The VAS was also significantly lower for the PFB patients at 10 pm on POD 0 (4.6 vs 1.6, P PFB 10.1%, P = .51) and there were no significant differences in residual sensory paresthesias (AB 2.3% [2/88] vs PFB 5.1% [4/79], P = .29), motor loss (0% vs 0%), or block site pain and/or erythema (AB 6.9% [6/88] vs PFB 5.1% [4/79], P = .44). The analgesic effect of the PFB lasted significantly longer when compared to the ankle block (AB 14.5 hours vs PFB 20.9 hours, P PFB 4.82/5, P = .68). Regional

  13. Two-stage IMZ implants and ITI implants inserted in a single-stage procedure. A prospective comparative study.

    Science.gov (United States)

    Heydenrijk, Kees; Raghoebar, Gerry M; Meijer, Henny J A; van der Reijden, Willy A; van Winkelhoff, Arie Jan; Stegenga, Boudewijn

    2002-08-01

    The aim of this study was to evaluate the feasibility of using a two-stage implant system in a single-stage procedure and to study the impact of the microgap at crestal level and to monitor the microflora in the peri-implant area. Forty edentulous patients (Cawood & Howell class V-VI) participated in this study. After randomisation, 20 patients received two IMZ implants inserted in a single-stage procedure and 20 patients received two ITI implants. After 3 months, overdentures were fabricated, supported by a bar and clip attachment. A standardised clinical and radiographic evaluation was performed immediately after denture insertion and 6 and 12 months later. Twelve months after loading, peri-implant samples were collected with sterile paper points and analysed for the presence of putative periodontal pathogens using culture techniques. One IMZ implant was lost due to insufficient osseointegration. With regard to the clinical parameters at the 12 months evaluation, significant differences for plaque score and probing pocket depth (IMZ: mean 3.3 mm, ITI: mean 2.9 mm) were found between the two groups. The mean bone loss in the first year of functioning was 0.6 mm for both groups. Prevotella intermedia was detected more often in the ITI group (12 implants) than in the IMZ group (three implants). Porphyromonas gingivalis was found in three patients. In one of these patients an implant showed bone loss of 1.6 mm between T0 and T12. Some associations were found between clinical parameters and the target microorganisms in the ITI group. These associations were not present in the IMZ group. The short-term results indicate that two-stage implants inserted in a single-stage procedure may be as predictable as one-stage implants. The microgap at crestal level in nonsubmerged IMZ implants seems to have no adverse influence on the peri-implant microbiological colonisation and of crestal bone loss in the first year of functioning. The peri-implant sulcus can and does harbour

  14. A Comparison of Exposure Control Procedures in CAT Systems Based on Different Measurement Models for Testlets

    Science.gov (United States)

    Boyd, Aimee M.; Dodd, Barbara; Fitzpatrick, Steven

    2013-01-01

    This study compared several exposure control procedures for CAT systems based on the three-parameter logistic testlet response theory model (Wang, Bradlow, & Wainer, 2002) and Masters' (1982) partial credit model when applied to a pool consisting entirely of testlets. The exposure control procedures studied were the modified within 0.10 logits…

  15. A testing procedure for wind turbine generators based on the power grid statistical model

    DEFF Research Database (Denmark)

    Farajzadehbibalan, Saber; Ramezani, Mohammad Hossein; Nielsen, Peter

    2017-01-01

    In this study, a comprehensive test procedure is developed to test wind turbine generators with a hardware-in-loop setup. The procedure employs the statistical model of the power grid considering the restrictions of the test facility and system dynamics. Given the model in the latent space, the j...

  16. Modeling Rabbit Responses to Single and Multiple Aerosol ...

    Science.gov (United States)

    Journal Article Survival models are developed here to predict response and time-to-response for mortality in rabbits following exposures to single or multiple aerosol doses of Bacillus anthracis spores. Hazard function models were developed for a multiple dose dataset to predict the probability of death through specifying dose-response functions and the time between exposure and the time-to-death (TTD). Among the models developed, the best-fitting survival model (baseline model) has an exponential dose-response model with a Weibull TTD distribution. Alternative models assessed employ different underlying dose-response functions and use the assumption that, in a multiple dose scenario, earlier doses affect the hazard functions of each subsequent dose. In addition, published mechanistic models are analyzed and compared with models developed in this paper. None of the alternative models that were assessed provided a statistically significant improvement in fit over the baseline model. The general approach utilizes simple empirical data analysis to develop parsimonious models with limited reliance on mechanistic assumptions. The baseline model predicts TTDs consistent with reported results from three independent high-dose rabbit datasets. More accurate survival models depend upon future development of dose-response datasets specifically designed to assess potential multiple dose effects on response and time-to-response. The process used in this paper to dev

  17. A RENORMALIZATION PROCEDURE FOR TENSOR MODELS AND SCALAR-TENSOR THEORIES OF GRAVITY

    OpenAIRE

    SASAKURA, NAOKI

    2010-01-01

    Tensor models are more-index generalizations of the so-called matrix models, and provide models of quantum gravity with the idea that spaces and general relativity are emergent phenomena. In this paper, a renormalization procedure for the tensor models whose dynamical variable is a totally symmetric real three-tensor is discussed. It is proven that configurations with certain Gaussian forms are the attractors of the three-tensor under the renormalization procedure. Since these Gaussian config...

  18. Bilateral Simultaneous Revision Total Knee Arthroplasty as a Single Staged Procedure: A Case Report and Review of Literature.

    Science.gov (United States)

    Vaishya, Raju; Agarwal, Amit Kumar; Jaiswal, Chirag; Vijay, Vipul; Vaish, Abhishek

    2017-03-23

    Bilateral revision total knee arthroplasty (TKA) is a surgical procedure, which is rarely done simultaneously as it is a difficult surgery and the safety of simultaneous bilateral single stage surgery remains unknown. We report a case of a 67-year-old woman who presented to us with bilateral painful and unstable TKA (right > left) of six months duration. The primary bilateral TKA were done 14 years ago. Bilateral simultaneous revision TKA was performed, using cemented, constrained, long-stem prostheses. The intraoperative and postoperative periods remained uneventful. At last follow-up at four years, she had a pain-free range of motion of up to 0-115°, and the patient had returned to the activities of daily living. She had stable knees with good function and no evidence of loosening or wear.

  19. PROCRU: A model for analyzing crew procedures in approach to landing

    Science.gov (United States)

    Baron, S.; Muralidharan, R.; Lancraft, R.; Zacharias, G.

    1980-01-01

    A model for analyzing crew procedures in approach to landing is developed. The model employs the information processing structure used in the optimal control model and in recent models for monitoring and failure detection. Mechanisms are added to this basic structure to model crew decision making in this multi task environment. Decisions are based on probability assessments and potential mission impact (or gain). Sub models for procedural activities are included. The model distinguishes among external visual, instrument visual, and auditory sources of information. The external visual scene perception models incorporate limitations in obtaining information. The auditory information channel contains a buffer to allow for storage in memory until that information can be processed.

  20. Parameter Estimation for Single Diode Models of Photovoltaic Modules

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Clifford [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Photovoltaic and Distributed Systems Integration Dept.

    2015-03-01

    Many popular models for photovoltaic system performance employ a single diode model to compute the I - V curve for a module or string of modules at given irradiance and temperature conditions. A single diode model requires a number of parameters to be estimated from measured I - V curves. Many available parameter estimation methods use only short circuit, o pen circuit and maximum power points for a single I - V curve at standard test conditions together with temperature coefficients determined separately for individual cells. In contrast, module testing frequently records I - V curves over a wide range of irradi ance and temperature conditions which, when available , should also be used to parameterize the performance model. We present a parameter estimation method that makes use of a fu ll range of available I - V curves. We verify the accuracy of the method by recov ering known parameter values from simulated I - V curves . We validate the method by estimating model parameters for a module using outdoor test data and predicting the outdoor performance of the module.

  1. Mechanistic modelling of the drying behaviour of single pharmaceutical granules

    DEFF Research Database (Denmark)

    Thérèse F.C. Mortier, Séverine; Beer, Thomas De; Gernaey, Krist

    2012-01-01

    The trend to move towards continuous production processes in pharmaceutical applications enhances the necessity to develop mechanistic models to understand and control these processes. This work focuses on the drying behaviour of a single wet granule before tabletting, using a six......-segmented fluidised bed drying system, which is part of a fully continuous from-powder-to-tablet manufacturing line. The drying model is based on a model described by Mezhericher et al. [1] and consists of two submodels. In the first drying phase (submodel 1), the surface water evaporates, while in the second drying...... phase (submodel 2), the water inside the granule evaporates. The second submodel contains an empirical power coefficient, b. A sensitivity analysis was performed to study the influence of parameters on the moisture content of single pharmaceutical granules, which clearly points towards the importance...

  2. Patients' and procedural characteristics of AV-block during slow pathway modulation for AVNRT-single center 10year experience.

    Science.gov (United States)

    Wasmer, Kristina; Dechering, Dirk G; Köbe, Julia; Leitz, Patrick; Frommeyer, Gerrit; Lange, Phillip S; Kochhäuser, Simon; Reinke, Florian; Pott, Christian; Mönnig, Gerold; Breithardt, Günter; Eckardt, Lars

    2017-10-01

    Permanent AV-block is a recognized and feared complication of slow pathway modulation for AVNRT. We aimed to assess incidence of transient and permanent AV-block as well as consequences of transient AV-block in a large contemporary AVNRT ablation cohort. We searched our single center prospective ablation database for occurrence of transient and permanent AV-block during slow pathway modulation between January 2004 and October 2015. We analyzed patients' and procedural characteristics as well as outcome of patients in whom transient or permanent AV-block occurred. Of 9170 patients who underwent a catheter ablation at our institution between January 2004 and October 2015, 2101 patients (64% women, mean age 50±18years) underwent slow pathway modulation. In three patients, permanent AV-block occurred during RF application. Additional two patients had transient AV-block that recovered (after a few minutes and 25min), but recurred within two days of the procedure. All five patients underwent dual chamber pacemaker implantation (0.2%). Transient AV-block related to RF delivery occurred in 44 patients (2%). Transient mechanical AV-block occurred in additional 17 patients (0.8%). In 12 patients, ablation was continued despite transient AV-block. One of these patients developed permanent AV-block. Permanent AV-block following slow pathway modulation is a rare event, occurring in 0.2% of patients in a large contemporary single center cohort. Transient AV-block is more frequent (2%). Copyright © 2017 Elsevier B.V. All rights reserved.

  3. A Stepwise Fitting Procedure for automated fitting of Ecopath with Ecosim models

    Directory of Open Access Journals (Sweden)

    Erin Scott

    2016-01-01

    Full Text Available The Stepwise Fitting Procedure automates testing of alternative hypotheses used for fitting Ecopath with Ecosim (EwE models to observation reference data (Mackinson et al. 2009. The calibration of EwE model predictions to observed data is important to evaluate any model that will be used for ecosystem based management. Thus far, the model fitting procedure in EwE has been carried out manually: a repetitive task involving setting >1000 specific individual searches to find the statistically ‘best fit’ model. The novel fitting procedure automates the manual procedure therefore producing accurate results and lets the modeller concentrate on investigating the ‘best fit’ model for ecological accuracy.

  4. Robotic-Assisted Transperitoneal Aortic Lymphadenectomy as Part of Staging Procedure for Gynaecological Malignancies: Single Institution Experience

    Directory of Open Access Journals (Sweden)

    V. Zanagnolo

    2013-01-01

    Full Text Available Introduction. This study was designed to confirm the feasibility and safety of robotic-assisted transperitoneal aortic lymphadenectomy as part of staging procedure for gynecologic malignancies. Methods. Chart review of 51 patients who had undergone robotic staging with aortic lymphadenectomy for different gynaecologic malignancies was performed. Results. The primary diagnosis was as follows: 6 cases of endometrial cancer, 31 epithelial ovarian cancer, 9 nonepithelial ovarian cancer, 4 tubal cancer, and 1 cervical cancer. Median BMI was 23 kg/m2. Except for a single case of aortic lymphadenectomy only, both aortic and pelvic lymphadenectomies were performed at the time of the staging procedure. All the para-aortic lymphadenectomies were carried out to the level of the renal veinl but 6 cases were carried out to the level of the inferior mesenteric artery. Hysterectomy was performed in 24 patiens (47%. There was no conversion to LPT. The median console time was 285 (range 195–402 with a significant difference between patients who underwent hysterectomy and those who did not. The median estimated blood loss was 50 mL (range 20–200. The mean number of removed nodes was 29±9.6. The mean number of pelvic nodes was 15±7.6, whereas the mean number of para-aortic nodes was 14±6.6. Conclusions. Robotic transperitoneal infrarenal aortic lymphadenectomy as part of staging procedure is feasible and can be safely performed. Additional trocars are needed when pelvic surgery is also performed.

  5. Multi-institutional Experience in Laparoendoscopic Single-site Surgery (LESS): For Major Extirpative and Reconstructive Procedures in Pediatric Urology.

    Science.gov (United States)

    Gor, Ronak A; Long, Christopher J; Shukla, Aseem R; Kirsch, Andrew J; Perez-Brayfield, Marcos; Srinivasan, Arun K

    2016-02-01

    To review peri-procedural outcomes from a large, multi-institutional series of pediatric urology patients treated with laparaendoscopic single-site surgery (LESS) for major extirpative and reconstructive procedures. Consecutive LESS cases between January 2011 and May 2014 from three free-standing pediatric referral centers were reviewed. Data include age, sex, operative time, blood loss, length of stay, and complications according to the modified Clavien-Dindo classification. Hasson technique was used for peritoneal entry, GelPOINT advanced access platform was inserted, and standard 5mm laparoscopic instruments were used. Fifty-nine patients (median age 5 years, 4 months-17 years) met inclusion criteria: 29 nephrectomies, 9 nephroureterectomies, 3 bilateral nephrectomies, 5 heminephrectomies, 5 renal cyst decortications, 3 bilateral gonadectomies, 2 Malone antegrade continence enema, 2 calyceal diverticulectomy, and 1 ovarian detorsion with cystectomy. Median operative times for each case type were comparable to published experiences with traditional laparoscopy. Overall mean and median length of stay was 36.2 hours and 1 day, respectively. There were two complications: port site hernia requiring surgical repair (Clavien IIIb) and a superficial port site infection that resolved with antibiotics (Clavien II). Cosmetic outcomes were subjectively well received by patients and their parents. Operative time was significantly shorter between the first half of the experience and the second half (102 vs 70 minutes, P  <  .05). LESS approach can be broadly applied across many major extirpative and reconstructive procedures within pediatric urology. Our series advances our field's utilization of this technique and its safety. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Evaluation of a Single Procedure Allowing the Isolation of Enteropathogenic Yersinia along with Other Bacterial Enteropathogens from Human Stools

    Science.gov (United States)

    Savin, Cyril; Leclercq, Alexandre; Carniel, Elisabeth

    2012-01-01

    Enteropathogenic Yersinia are among the most frequent agents of human diarrhea in temperate and cold countries. However, the incidence of yersiniosis is largely underestimated because of the peculiar growth characteristics of pathogenic Yersinia, which make their isolation from poly-contaminated samples difficult. The use of specific procedures for Yersinia isolation is required, but is expensive and time consuming, and therefore is not systematically performed in clinical pathology laboratories. A means to circumvent this problem would be to use a single procedure for the isolation of all bacterial enteropathogens. Since the Statens Serum Institut enteric medium (SSI) has been reported to allow the growth at 37°C of most Gram-negative bacteria, including Yersinia, our study aimed at evaluating its performances for Yersinia isolation, as compared to the commonly used Yersinia-specific semi-selective Cefsulodin-Irgasan-Novobiocin medium (CIN) incubated at 28°C. Our results show that Yersinia pseudotuberculosis growth was strongly inhibited on SSI at 37°C, and therefore that this medium is not suitable for the isolation of this species. All Yersinia enterocolitica strains tested grew on SSI, while some non-pathogenic Yersinia species were inhibited. The morphology of Y. enterocolitica colonies on SSI allowed their differentiation from various other Gram-negative bacteria commonly isolated from stool samples. However, in artificially contaminated human stools, the recovery of Y. enterocolitica colonies on SSI at 37°C was difficult and was 3 logs less sensitive than on CIN at 28°C. Therefore, despite its limitations, the use of a specific procedure (CIN incubated at 28°C) is still required for an efficient isolation of enteropathogenic Yersinia from stools. PMID:22911756

  7. Constitutional Justice Procedure in Lithuania: a Search for Optimal Model

    OpenAIRE

    Pūraitė-Andrikienė, Dovilė

    2017-01-01

    The dissertation systematically analyzes the preconditions for optimising the existing constitutional justice model, i.e. whether the current model meets the expectations of Lithuanian society and the legal community, corresponds to the capabilities of the legal system, and is in line with the tendencies of constitutional justice in European states, identifies the problematic aspects of the existing constitutional justice model and brings forward proposals regarding how the legal regulation c...

  8. Computational models of the single substitutional nitrogen atom in diamond

    CERN Document Server

    Lombardi, E B; Osuch, K; Reynhardt, E C

    2003-01-01

    The single substitutional nitrogen atom in diamond is apparently a very simple defect in a very simple elemental solid. It has been modelled by a range of computational models, few of which either agree with each other, or with the experimental data on the defect. If the computational models of less well understood defects in this and more complex materials are to be reliable, we should understand why the discrepancies arise and how they can be avoided in future modelling. This paper presents an all-electron, augmented plane-wave (APW) density functional theory (DFT) calculation using the modern APW with local orbitals full potential periodic approximation. This is compared to DFT, finite cluster pseudopotential calculations and a semi-empirical Hartree-Fock model. Comparisons between the results of these and previous models allow us to discuss the reliability of computational methods of this and similar defects.

  9. modelling room cooling capacity with fuzzy logic procedure

    African Journals Online (AJOL)

    user

    for automatic and economical supplementary tools that will allow expertise input into design process [9]. Reasoning based on fuzzy models was however identified to provide an optional direction of handling the way humans think and make judgments [10]. This study developed and validated a model capable of estimating ...

  10. modelling room cooling capacity with fuzzy logic procedure

    African Journals Online (AJOL)

    The primary aim of this study is to develop a model for estimation of the cooling requirement of residential rooms. Fuzzy logic was employed to model four input variables (window area (m2), roof area (m2), external wall area (m2) and internal load (Watt). The algorithm of the inference engine applied sets of 81 linguistic ...

  11. Computational Modeling of Photonic Crystal Microcavity Single-Photon Emitters

    Science.gov (United States)

    Saulnier, Nicole A.

    Conventional cryptography is based on algorithms that are mathematically complex and difficult to solve, such as factoring large numbers. The advent of a quantum computer would render these schemes useless. As scientists work to develop a quantum computer, cryptographers are developing new schemes for unconditionally secure cryptography. Quantum key distribution has emerged as one of the potential replacements of classical cryptography. It relics on the fact that measurement of a quantum bit changes the state of the bit and undetected eavesdropping is impossible. Single polarized photons can be used as the quantum bits, such that a quantum system would in some ways mirror the classical communication scheme. The quantum key distribution system would include components that create, transmit and detect single polarized photons. The focus of this work is on the development of an efficient single-photon source. This source is comprised of a single quantum dot inside of a photonic crystal microcavity. To better understand the physics behind the device, a computational model is developed. The model uses Finite-Difference Time-Domain methods to analyze the electromagnetic field distribution in photonic crystal microcavities. It uses an 8-band k · p perturbation theory to compute the energy band structure of the epitaxially grown quantum dots. We discuss a method that combines the results of these two calculations for determining the spontaneous emission lifetime of a quantum dot in bulk material or in a microcavity. The computational models developed in this thesis are used to identify and characterize microcavities for potential use in a single-photon source. The computational tools developed are also used to investigate novel photonic crystal microcavities that incorporate 1D distributed Bragg reflectors for vertical confinement. It is found that the spontaneous emission enhancement in the quasi-3D cavities can be significantly greater than in traditional suspended slab

  12. Computer-Based Procedures for Field Workers in Nuclear Power Plants: Development of a Model of Procedure Usage and Identification of Requirements

    Energy Technology Data Exchange (ETDEWEB)

    Katya Le Blanc; Johanna Oxstrand

    2012-04-01

    The nuclear industry is constantly trying to find ways to decrease the human error rate, especially the human errors associated with procedure use. As a step toward the goal of improving procedure use performance, researchers, together with the nuclear industry, have been looking at replacing the current paper-based procedures with computer-based procedure systems. The concept of computer-based procedures is not new by any means; however most research has focused on procedures used in the main control room. Procedures reviewed in these efforts are mainly emergency operating procedures and normal operating procedures. Based on lessons learned for these previous efforts we are now exploring a more unknown application for computer based procedures - field procedures, i.e. procedures used by nuclear equipment operators and maintenance technicians. The Idaho National Laboratory and participants from the U.S. commercial nuclear industry are collaborating in an applied research effort with the objective of developing requirements and specifications for a computer-based procedure system to be used by field workers. The goal is to identify the types of human errors that can be mitigated by using computer-based procedures and how to best design the computer-based procedures to do so. This paper describes the development of a Model of Procedure Use and the qualitative study on which the model is based. The study was conducted in collaboration with four nuclear utilities and five research institutes. During the qualitative study and the model development requirements and for computer-based procedures were identified.

  13. Single-crystal diffraction at the Extreme Conditions beamline P02.2: procedure for collecting and analyzing high-pressure single-crystal data.

    Science.gov (United States)

    Rothkirch, André; Gatta, G Diego; Meyer, Mathias; Merkel, Sébastien; Merlini, Marco; Liermann, Hanns Peter

    2013-09-01

    Fast detectors employed at third-generation synchrotrons have reduced collection times significantly and require the optimization of commercial as well as customized software packages for data reduction and analysis. In this paper a procedure to collect, process and analyze single-crystal data sets collected at high pressure at the Extreme Conditions beamline (P02.2) at PETRA III, DESY, is presented. A new data image format called `Esperanto' is introduced that is supported by the commercial software package CrysAlis(Pro) (Agilent Technologies UK Ltd). The new format acts as a vehicle to transform the most common area-detector data formats via a translator software. Such a conversion tool has been developed and converts tiff data collected on a Perkin Elmer detector, as well as data collected on a MAR345/555, to be imported into the CrysAlis(Pro) software. In order to demonstrate the validity of the new approach, a complete structure refinement of boron-mullite (Al5BO9) collected at a pressure of 19.4 (2) GPa is presented. Details pertaining to the data collections and refinements of B-mullite are presented.

  14. Procedures and models for estimating preconstruction costs of highway projects.

    Science.gov (United States)

    2012-07-01

    This study presents data driven and component based PE cost prediction models by utilizing critical factors retrieved from ten years of historical project data obtained from ODOT roadway division. The study used factor analysis of covariance and corr...

  15. Single-Index Additive Vector Autoregressive Time Series Models

    KAUST Repository

    LI, YEHUA

    2009-09-01

    We study a new class of nonlinear autoregressive models for vector time series, where the current vector depends on single-indexes defined on the past lags and the effects of different lags have an additive form. A sufficient condition is provided for stationarity of such models. We also study estimation of the proposed model using P-splines, hypothesis testing, asymptotics, selection of the order of the autoregression and of the smoothing parameters and nonlinear forecasting. We perform simulation experiments to evaluate our model in various settings. We illustrate our methodology on a climate data set and show that our model provides more accurate yearly forecasts of the El Niño phenomenon, the unusual warming of water in the Pacific Ocean. © 2009 Board of the Foundation of the Scandinavian Journal of Statistics.

  16. A simple but accurate procedure for solving the five-parameter model

    International Nuclear Information System (INIS)

    Mares, Oana; Paulescu, Marius; Badescu, Viorel

    2015-01-01

    Highlights: • A new procedure for extracting the parameters of the one-diode model is proposed. • Only the basic information listed in the datasheet of PV modules are required. • Results demonstrate a simple, robust and accurate procedure. - Abstract: The current–voltage characteristic of a photovoltaic module is typically evaluated by using a model based on the solar cell equivalent circuit. The complexity of the procedure applied for extracting the model parameters depends on data available in manufacture’s datasheet. Since the datasheet is not detailed enough, simplified models have to be used in many cases. This paper proposes a new procedure for extracting the parameters of the one-diode model in standard test conditions, using only the basic data listed by all manufactures in datasheet (short circuit current, open circuit voltage and maximum power point). The procedure is validated by using manufacturers’ data for six commercially crystalline silicon photovoltaic modules. Comparing the computed and measured current–voltage characteristics the determination coefficient is in the range 0.976–0.998. Thus, the proposed procedure represents a feasible tool for solving the five-parameter model applied to crystalline silicon photovoltaic modules. The procedure is described in detail, to guide potential users to derive similar models for other types of photovoltaic modules.

  17. [The emphases and basic procedures of genetic counseling in psychotherapeutic model].

    Science.gov (United States)

    Zhang, Yuan-Zhi; Zhong, Nanbert

    2006-11-01

    The emphases and basic procedures of genetic counseling are all different with those in old models. In the psychotherapeutic model, genetic counseling will not only focus on counselees' genetic disorders and birth defects, but also their psychological problems. "Client-centered therapy" termed by Carl Rogers plays an important role in genetic counseling process. The basic procedures of psychotherapeutic model of genetic counseling include 7 steps: initial contact, introduction, agendas, inquiry of family history, presenting information, closing the session and follow-up.

  18. Bayesian analysis of inflation: Parameter estimation for single field models

    International Nuclear Information System (INIS)

    Mortonson, Michael J.; Peiris, Hiranya V.; Easther, Richard

    2011-01-01

    Future astrophysical data sets promise to strengthen constraints on models of inflation, and extracting these constraints requires methods and tools commensurate with the quality of the data. In this paper we describe ModeCode, a new, publicly available code that computes the primordial scalar and tensor power spectra for single-field inflationary models. ModeCode solves the inflationary mode equations numerically, avoiding the slow roll approximation. It is interfaced with CAMB and CosmoMC to compute cosmic microwave background angular power spectra and perform likelihood analysis and parameter estimation. ModeCode is easily extendable to additional models of inflation, and future updates will include Bayesian model comparison. Errors from ModeCode contribute negligibly to the error budget for analyses of data from Planck or other next generation experiments. We constrain representative single-field models (φ n with n=2/3, 1, 2, and 4, natural inflation, and 'hilltop' inflation) using current data, and provide forecasts for Planck. From current data, we obtain weak but nontrivial limits on the post-inflationary physics, which is a significant source of uncertainty in the predictions of inflationary models, while we find that Planck will dramatically improve these constraints. In particular, Planck will link the inflationary dynamics with the post-inflationary growth of the horizon, and thus begin to probe the ''primordial dark ages'' between TeV and grand unified theory scale energies.

  19. A macroscopic model for magnetic shape-memory single crystals

    Czech Academy of Sciences Publication Activity Database

    Bessoud, A. L.; Kružík, Martin; Stefanelli, U.

    2013-01-01

    Roč. 64, č. 2 (2013), s. 343-359 ISSN 0044-2275 R&D Projects: GA AV ČR IAA100750802; GA ČR GAP201/10/0357 Institutional support: RVO:67985556 Keywords : magneto striction * evolution Subject RIV: BA - General Mathematics Impact factor: 1.214, year: 2013 http://library.utia.cas.cz/separaty/2012/MTR/kruzik-a macroscopic model for magnetic shape-memory single crystals.pdf

  20. Unified Model of Dynamic Forced Barrier Crossing in Single Molecules

    Energy Technology Data Exchange (ETDEWEB)

    Friddle, R W

    2007-06-21

    Thermally activated barrier crossing in the presence of an increasing load can reveal kinetic rate constants and energy barrier parameters when repeated over a range of loading rates. Here we derive a model of the mean escape force for all relevant loading rates--the complete force spectrum. Two well-known approximations emerge as limiting cases; one of which confirms predictions that single-barrier spectra should converge to a phenomenological description in the slow loading limit.

  1. An atomic model for neutral and singly ionized uranium

    Science.gov (United States)

    Maceda, E. L.; Miley, G. H.

    1979-01-01

    A model for the atomic levels above ground state in neutral, U(0), and singly ionized, U(+), uranium is described based on identified atomic transitions. Some 168 states in U(0) and 95 in U(+) are found. A total of 1581 atomic transitions are used to complete this process. Also discussed are the atomic inverse lifetimes and line widths for the radiative transitions as well as the electron collisional cross sections.

  2. Stochastic models for spike trains of single neurons

    CERN Document Server

    Sampath, G

    1977-01-01

    1 Some basic neurophysiology 4 The neuron 1. 1 4 1. 1. 1 The axon 7 1. 1. 2 The synapse 9 12 1. 1. 3 The soma 1. 1. 4 The dendrites 13 13 1. 2 Types of neurons 2 Signals in the nervous system 14 2. 1 Action potentials as point events - point processes in the nervous system 15 18 2. 2 Spontaneous activi~ in neurons 3 Stochastic modelling of single neuron spike trains 19 3. 1 Characteristics of a neuron spike train 19 3. 2 The mathematical neuron 23 4 Superposition models 26 4. 1 superposition of renewal processes 26 4. 2 Superposition of stationary point processe- limiting behaviour 34 4. 2. 1 Palm functions 35 4. 2. 2 Asymptotic behaviour of n stationary point processes superposed 36 4. 3 Superposition models of neuron spike trains 37 4. 3. 1 Model 4. 1 39 4. 3. 2 Model 4. 2 - A superposition model with 40 two input channels 40 4. 3. 3 Model 4. 3 4. 4 Discussion 41 43 5 Deletion models 5. 1 Deletion models with 1nd~endent interaction of excitatory and inhibitory sequences 44 VI 5. 1. 1 Model 5. 1 The basic de...

  3. Computational model for dosimetric purposes in dental procedures

    International Nuclear Information System (INIS)

    Kawamoto, Renato H.; Campos, Tarcisio R.

    2013-01-01

    This study aims to develop a computational model for dosimetric purposes the oral region, based on computational tools SISCODES and MCNP-5, to predict deterministic effects and minimize stochastic effects caused by ionizing radiation by radiodiagnosis. Based on a set of digital information provided by computed tomography, three-dimensional voxel model was created, and its tissues represented. The model was exported to the MCNP code. In association with SICODES, we used the Monte Carlo N-Particle Transport Code (MCNP-5) method to play the corresponding interaction of nuclear particles with human tissues statistical process. The study will serve as a source of data for dosimetric studies in the oral region, providing deterministic effect and minimize the stochastic effect of ionizing radiation

  4. Information matrix estimation procedures for cognitive diagnostic models.

    Science.gov (United States)

    Liu, Yanlou; Xin, Tao; Andersson, Björn; Tian, Wei

    2018-03-06

    Two new methods to estimate the asymptotic covariance matrix for marginal maximum likelihood estimation of cognitive diagnosis models (CDMs), the inverse of the observed information matrix and the sandwich-type estimator, are introduced. Unlike several previous covariance matrix estimators, the new methods take into account both the item and structural parameters. The relationships between the observed information matrix, the empirical cross-product information matrix, the sandwich-type covariance matrix and the two approaches proposed by de la Torre (2009, J. Educ. Behav. Stat., 34, 115) are discussed. Simulation results show that, for a correctly specified CDM and Q-matrix or with a slightly misspecified probability model, the observed information matrix and the sandwich-type covariance matrix exhibit good performance with respect to providing consistent standard errors of item parameter estimates. However, with substantial model misspecification only the sandwich-type covariance matrix exhibits robust performance. © 2018 The British Psychological Society.

  5. Connecting single-stock assessment models through correlated survival

    DEFF Research Database (Denmark)

    Albertsen, Christoffer Moesgaard; Nielsen, Anders; Thygesen, Uffe Høgsbro

    2017-01-01

    the corresponding partial correlations. We consider six models where the partial correlation matrix between stocks follows a band structure ranging from independent assessments to complex correlation structures. Further, a simulation study illustrates the importance of handling correlated data sufficiently...... times. We propose a simple alternative. In three case studies each with two stocks, we improve the single-stock models, as measured by Akaike information criterion, by adding correlation in the cohort survival. To limit the number of parameters, the correlations are parameterized through...

  6. Predictive market segmentation model: An application of logistic regression model and CHAID procedure

    Directory of Open Access Journals (Sweden)

    Soldić-Aleksić Jasna

    2009-01-01

    Full Text Available Market segmentation presents one of the key concepts of the modern marketing. The main goal of market segmentation is focused on creating groups (segments of customers that have similar characteristics, needs, wishes and/or similar behavior regarding the purchase of concrete product/service. Companies can create specific marketing plan for each of these segments and therefore gain short or long term competitive advantage on the market. Depending on the concrete marketing goal, different segmentation schemes and techniques may be applied. This paper presents a predictive market segmentation model based on the application of logistic regression model and CHAID analysis. The logistic regression model was used for the purpose of variables selection (from the initial pool of eleven variables which are statistically significant for explaining the dependent variable. Selected variables were afterwards included in the CHAID procedure that generated the predictive market segmentation model. The model results are presented on the concrete empirical example in the following form: summary model results, CHAID tree, Gain chart, Index chart, risk and classification tables.

  7. An auto-calibration procedure for empirical solar radiation models

    NARCIS (Netherlands)

    Bojanowski, J.S.; Donatelli, Marcello; Skidmore, A.K.; Vrieling, A.

    2013-01-01

    Solar radiation data are an important input for estimating evapotranspiration and modelling crop growth. Direct measurement of solar radiation is now carried out in most European countries, but the network of measuring stations is too sparse for reliable interpolation of measured values. Instead of

  8. Constructing Self-Modeling Videos: Procedures and Technology

    Science.gov (United States)

    Collier-Meek, Melissa A.; Fallon, Lindsay M.; Johnson, Austin H.; Sanetti, Lisa M. H.; Delcampo, Marisa A.

    2012-01-01

    Although widely recommended, evidence-based interventions are not regularly utilized by school practitioners. Video self-modeling is an effective and efficient evidence-based intervention for a variety of student problem behaviors. However, like many other evidence-based interventions, it is not frequently used in schools. As video creation…

  9. Comparative study of afterpulsing behavior and models in single photon counting avalanche photo diode detectors.

    Science.gov (United States)

    Ziarkash, Abdul Waris; Joshi, Siddarth Koduru; Stipčević, Mario; Ursin, Rupert

    2018-03-22

    Single-photon avalanche diode (SPAD) detectors, have a great importance in fields like quantum key distribution, laser ranging, florescence microscopy, etc. Afterpulsing is a non-ideal behavior of SPADs that adversely affects any application that measures the number or timing of detection events. Several studies based on a few individual detectors, derived distinct mathematical models from semiconductor physics perspectives. With a consistent testing procedure and statistically large data sets, we show that different individual detectors - even if identical in type, make, brand, etc. - behave according to fundamentally different mathematical models. Thus, every detector must be characterized individually and it is wrong to draw universal conclusions about the physical meaning behind these models. We also report the presence of high-order afterpulses that are not accounted for in any of the standard models.

  10. TSCALE: A New Multidimensional Scaling Procedure Based on Tversky's Contrast Model.

    Science.gov (United States)

    DeSarbo, Wayne S.; And Others

    1992-01-01

    TSCALE, a multidimensional scaling procedure based on the contrast model of A. Tversky for asymmetric three-way, two-mode proximity data, is presented. TSCALE conceptualizes a latent dimensional structure to describe the judgmental stimuli. A Monte Carlo analysis and two consumer psychology applications illustrate the procedure. (SLD)

  11. Dynamic Human Body Modeling Using a Single RGB Camera.

    Science.gov (United States)

    Zhu, Haiyu; Yu, Yao; Zhou, Yu; Du, Sidan

    2016-03-18

    In this paper, we present a novel automatic pipeline to build personalized parametric models of dynamic people using a single RGB camera. Compared to previous approaches that use monocular RGB images, our system can model a 3D human body automatically and incrementally, taking advantage of human motion. Based on coarse 2D and 3D poses estimated from image sequences, we first perform a kinematic classification of human body parts to refine the poses and obtain reconstructed body parts. Next, a personalized parametric human model is generated by driving a general template to fit the body parts and calculating the non-rigid deformation. Experimental results show that our shape estimation method achieves comparable accuracy with reconstructed models using depth cameras, yet requires neither user interaction nor any dedicated devices, leading to the feasibility of using this method on widely available smart phones.

  12. Biomechanical comparisons of knee stability after anterior cruciate ligament reconstruction between 2 clinically available transtibial procedures: anatomic double bundle versus single bundle.

    Science.gov (United States)

    Kondo, Eiji; Merican, Azhar M; Yasuda, Kazunori; Amis, Andrew A

    2010-07-01

    Several trials have compared the clinical results between anatomic double-bundle and single-bundle anterior cruciate ligament reconstruction procedures. However, it remains controversial whether the anatomic double-bundle procedure is superior to the single-bundle procedure. The anatomic double-bundle procedure will be better than the single-bundle procedure at resisting anterior laxity, internal rotation laxity, and pivot-shift instability. Controlled laboratory study. Eight cadaveric knees were tested in a 6 degrees of freedom rig using the following loading conditions: 90-N anterior tibialforce, 5-N.m internal and external tibial torques, and a simulated pivot-shift test. Tibiofemoral kinematics during the flexion-extension cycle were recorded with an optical tracking system for (1) intact, (2) anterior cruciate ligament-deficient knee, (3) anatomic double-bundle reconstruction, and (4) single-bundle reconstruction placed at 11 o'clock in the intercondylar notch. There were significant reductions of anterior laxity of 3.5 mm at 20 degrees of flexion, internal rotational laxity of 2.5 degrees at 20 degrees of flexion, and anterior translations (2 mm) and internal rotations (5 degrees ) in the simulated pivot-shift test in the double-bundle reconstruction com-pared with the single-bundle reconstruction. There were no significant differences between the 2 procedures for external rotation laxity. The postoperative anterior translation and internal rotation stability after anatomic double-bundle anterior cruciate ligament reconstruction were significantly better than after single-bundle reconstruction, in both static tests and the pivot shift. Unlike previous laboratory studies, this work used clinical arthroscopic methods for anterior cruciate ligament reconstruction, and found that the anatomic reconstruction was superior to a single graft placed at 11 o'clock.

  13. Development of procedures to stabilize chlorfenvinphos in model cattle dips

    Energy Technology Data Exchange (ETDEWEB)

    Caceres, Tanya [Pontificia Universidad Catolica del Ecuador, Quito (Ecuador). Dept. de Biologia; University of South Australia (Australia). Centre for Environmental Risk Assessment and Remediation (CERAR); E-mail: cactp001@students.unisa.edu.au; Pastor, Yolanda; Merino, Ramiro [Comision Ecuatoriana de Energia Atomica, Quito (Ecuador). Dept. de Ecotoxicologia

    2007-07-01

    The environmental fate and dissipation of the acaricide chlorfenvinphos was studied in water and sediment in model cattle dips with monthly recharge and without monthly recharge. Chlorfenvinphos concentration decreased with time in both model dips and the monthly recharge at 10% of the initial concentration was inefficient to maintain the right concentration which would be effective for tick control. Volatilization was the principal factor that influenced the dissipation of the pesticide. The sediment bound residues increased with time. Mineralization of {sup 14}C- chlorfenvinphos due to microbial activity showed that the {sup 14}CO{sub 2} production increased with time in biometers flasks with different amounts of sediment. 2,4 - dichloroacetophenone, and 2,4-dichlorobenzaldehyde were identified as degradation products. Isomerization of chlorfenvinphos from isomer Z to E was influenced by sunlight and it affected the efficiency of the pesticide as Z isomer is more active on tick control than E isomer. (author)

  14. Comparison of Estimation Procedures for Multilevel AR(1 Models

    Directory of Open Access Journals (Sweden)

    Tanja eKrone

    2016-04-01

    Full Text Available To estimate a time series model for multiple individuals, a multilevel model may be used.In this paper we compare two estimation methods for the autocorrelation in Multilevel AR(1 models, namely Maximum Likelihood Estimation (MLE and Bayesian Markov Chain Monte Carlo.Furthermore, we examine the difference between modeling fixed and random individual parameters.To this end, we perform a simulation study with a fully crossed design, in which we vary the length of the time series (10 or 25, the number of individuals per sample (10 or 25, the mean of the autocorrelation (-0.6 to 0.6 inclusive, in steps of 0.3 and the standard deviation of the autocorrelation (0.25 or 0.40.We found that the random estimators of the population autocorrelation show less bias and higher power, compared to the fixed estimators. As expected, the random estimators profit strongly from a higher number of individuals, while this effect is small for the fixed estimators.The fixed estimators profit slightly more from a higher number of time points than the random estimators.When possible, random estimation is preferred to fixed estimation.The difference between MLE and Bayesian estimation is nearly negligible. The Bayesian estimation shows a smaller bias, but MLE shows a smaller variability (i.e., standard deviation of the parameter estimates.Finally, better results are found for a higher number of individuals and time points, and for a lower individual variability of the autocorrelation. The effect of the size of the autocorrelation differs between outcome measures.

  15. Kinematic arguments against single relativistic shell models for GRBs

    Science.gov (United States)

    Fenimore, Edward E.; Ramirez, E.; Sumner, M. C.

    1997-01-01

    Two main types of models have been suggested to explain the long durations and multiple peaks of Gamma Ray Bursts (GRBs). In one, there is a very quick release of energy at a central site resulting in a single relativistic shell that produces peaks in the time history through its interactions with the ambient material. In the other, the central site sporadically releases energy over hundreds of seconds forming a peak with each burst of energy. The authors show that the average envelope of emission and the presence of gaps in GRBs are inconsistent with a single relativistic shell. They estimate that the maximum fraction of a single shell that can produce gamma-rays in a GRB with multiple peaks is 10(exp (minus)3), implying that single relativistic shells require 10(exp 3) times more energy than previously thought. They conclude that either the central site of a GRB must produce (approx)10(exp 51) erg/s(exp (minus)1) for hundreds of seconds, or the relativistic shell must have structure on a scales the order of (radical)(epsilon)(Gamma)(exp (minus)1), where (Gamma) is the bulk Lorentz factor ((approximately)10(exp 2) to 10(exp 3)) and (epsilon) is the efficiency.

  16. Thermal asymmetry model of single slope single basin solar still with sponge liner

    Directory of Open Access Journals (Sweden)

    Shanmugan Sengottain

    2014-01-01

    Full Text Available An attempt has been made to propose a thermal asymmetry model for single slope basin type solar still with sponge liner of different thickness (3cm, 5cm, and 10cm in the basin. Two different color sponge liners have been used i.e., yellow and black. In the proposed design, a suitable dripping arrangement has been designed and used to pour water drop by drop over the sponge liner instead of sponge liner in stagnant saline water in the basin. The special arrangement overcomes the dryness of the sponge during peak sunny hours. The performance of the system with black color sponge of 3cm thickness shows better result with an output of 5.3 kg/m2 day and the proposed model have used to find the thermal asymmetries during the working hours of the still.

  17. A baseline-free procedure for transformation models under interval censorship.

    Science.gov (United States)

    Gu, Ming Gao; Sun, Liuquan; Zuo, Guoxin

    2005-12-01

    An important property of Cox regression model is that the estimation of regression parameters using the partial likelihood procedure does not depend on its baseline survival function. We call such a procedure baseline-free. Using marginal likelihood, we show that an baseline-free procedure can be derived for a class of general transformation models under interval censoring framework. The baseline-free procedure results a simplified and stable computation algorithm for some complicated and important semiparametric models, such as frailty models and heteroscedastic hazard/rank regression models, where the estimation procedures so far available involve estimation of the infinite dimensional baseline function. A detailed computational algorithm using Markov Chain Monte Carlo stochastic approximation is presented. The proposed procedure is demonstrated through extensive simulation studies, showing the validity of asymptotic consistency and normality. We also illustrate the procedure with a real data set from a study of breast cancer. A heuristic argument showing that the score function is a mean zero martingale is provided.

  18. Spin models for the single molecular magnet Mn12-AC

    Science.gov (United States)

    Al-Saqer, Mohamad A.

    2005-11-01

    The single molecular magnet (SMM) Mn12-AC attracted the attention of scientists since the discovery of its magnetic hystereses which are accompanied by sudden jumps in magnetic moments at low temperature. Unlike conventional bulk magnets, hysteresis in SMMs is of molecular origin. This qualifies them as candidates for next generation of high density storage media where a molecule which is at most few nanometers in size can be used to store a bit of information. However, the jumps in these hystereses, due to spin tunneling, can lead to undesired loss of information. Mn12-AC molecule contains twelve magnetic ions antiferromagnetically coupled by exchanges leading to S = 10 ground state manifold. The magnetic ions are surrounded by ligands which isolate them magnetically from neighboring molecules. The lowest state of S = 9 manifold is believed to lie at about 40 K above the ground state. Therefore, at low temperatures, the molecule is considered as a single uncoupled moment of spin S = 10. Such model has been used widely to understand phenomena exhibited by the molecule at low temperatures including the tunneling of its spin, while a little attention has been paid for the multi-spin nature of the molecule. Using the 8-spin model, we demonstrate that in order to understand the phenomena of tunneling, a full spin description of the molecule is required. We utilized a calculation scheme where a fraction of energy levels are used in the calculations and the influence of levels having higher energy is neglected. From the dependence of tunnel splittings on the number of states include, we conclude that models based on restricting the number of energy levels (single-spin and 8-spin models) lead to unreliable results of tunnel splitting calculations. To attack the full 12-spin model, we employed the Davidson algorithm to calculated lowest energy levels produced by exchange interactions and single ion anisotropies. The model reproduces the anisotropy properties at low

  19. Screening Test Procedure For Long Life Single Mode Step Index Separate Confinement Heterostructure Single Quantum Well (Sinsch-Sqw) Laser Diodes

    Science.gov (United States)

    Fritz, William J.

    1989-06-01

    An experiment was conducted to establish an effective burn-in and screening procedure for long life SINSCH-SQW laser diodes. The laser diodes were grown by MOCVD and processed with 20μ wide oxide defined stripes. The devices had a high reflective back facet coating with a small etalon bonded to a passivated front facet to ensure single mode operation. The laser diodes were bonded p-side up to copper heat sinks using indium solder. A total of 48 devices were selected prior to burn-in and were operated at 200mA constant current for 2000 hours at an average heat sink temperature of 55°C. The average initial output power was 45mW per device. At the end of the test, the output powers ranged from lmW to 85mW. Most of the devices with the low final power failed catastrophically within 24 hours from the start of the test. Many laser diodes showed very little change in output power while others degraded gradually by varying amounts. Failure analysis showed that failures were facet, bulk, or heat sink related. The temporal output power degradations (i.e., gradual degradation, etc.) can be explained by the identified failure mechanisms. From the test results and failure analysis, a screening strategy based on inspection and burn-in can be devised to reject devices that may fail early. Also, improvements in processing can provide potential yield improvements. After accounting for degradation related to processing, a very long material lifetime is predicted for these SINSCH-SQW laser diodes.

  20. Risk factors for surgical site infection following nonshunt pediatric neurosurgery: a review of 9296 procedures from a national database and comparison with a single-center experience

    Science.gov (United States)

    Sherrod, Brandon A.; Arynchyna, Anastasia A.; Johnston, James M.; Rozzelle, Curtis J.; Blount, Jeffrey P.; Oakes, W. Jerry; Rocque, Brandon G.

    2017-01-01

    operation (OR 1.843, 95% CI 1.011–3.360, p = 0.046), spine procedures (OR 1.673, 95% CI 1.036–2.702, p = 0.035), acquired CNS abnormality (OR 1.620, 95% CI 1.085–2.420, p = 0.018), and female sex (OR 1.475, 95% CI 1.062–2.049, p = 0.021). The only COA factor independently associated with SSI in the COA database included clean-contaminated wound classification (OR 3.887, 95% CI 1.354–11.153, p = 0.012), with public insurance (OR 1.966, 95% CI 0.957–4.041, p = 0.066) and spine procedures (OR 1.982, 95% CI 0.955–4.114, p = 0.066) approaching significance. Both NSQIP-P and COA multivariate model C-statistics were > 0.7. Conclusions NSQIP-P SSI rates, but not risk factors, were similar to data from a single center. PMID:28186476

  1. Risk factors for surgical site infection following nonshunt pediatric neurosurgery: a review of 9296 procedures from a national database and comparison with a single-center experience.

    Science.gov (United States)

    Sherrod, Brandon A; Arynchyna, Anastasia A; Johnston, James M; Rozzelle, Curtis J; Blount, Jeffrey P; Oakes, W Jerry; Rocque, Brandon G

    2017-04-01

    .843, 95% CI 1.011-3.360, p = 0.046), spine procedures (OR 1.673, 95% CI 1.036-2.702, p = 0.035), acquired CNS abnormality (OR 1.620, 95% CI 1.085-2.420, p = 0.018), and female sex (OR 1.475, 95% CI 1.062-2.049, p = 0.021). The only COA factor independently associated with SSI in the COA database included clean-contaminated wound classification (OR 3.887, 95% CI 1.354-11.153, p = 0.012), with public insurance (OR 1.966, 95% CI 0.957-4.041, p = 0.066) and spine procedures (OR 1.982, 95% CI 0.955-4.114, p = 0.066) approaching significance. Both NSQIP-P and COA multivariate model C-statistics were > 0.7. CONCLUSIONS The NSQIP-P SSI rates, but not risk factors, were similar to data from a single center.

  2. Development of procedures to stabilize chlorfenvinphos in model cattle dips

    International Nuclear Information System (INIS)

    Pastor, Y.; Caceres, T.; Merino, R.; Villamar, P.; Castro, R.

    1997-01-01

    The environmental fate and dissipation of chlorfenvinphos acaricide was studied in water and sediment in model cattle dips with recharge, without recharge and with added stabilizers. Chlorfenvinphos concentration decreased with time in all of them, and the monthly recharge at 10% of the initial concentration was inefficient to maintain a concentration that would be effective for tick control. However, the loss of pesticide in the model dip with added phosphate buffer as stabilizer was the least. Volatilization was the principal factor that influenced the dissipation of the pesticide. The sediment bound residues increased with time. Mineralization of 14 C-chlorfenvinphos due to microbial activity showed that the 14 CO 2 production increased with time in biometers flasks with different amounts of sediment. 2,4-Dichloroacetophenone, and 2,4-dichlorobenzaldehyde were identified as degradation products. Isomerization of chlorfenviphos from isomer Z to E was influenced by sunlight. Chlorfenvinphos was stable in aqueous solution for 14 days under pH 4 to 9. Leaching tests demonstrated that the pesticide was not a potential pollutant of ground water. (author)

  3. Scaling properties in single collision model of light ion reflection

    International Nuclear Information System (INIS)

    Vukanic, J.; Simovic, R.

    2004-01-01

    Light ion reflection from solids in the keV energy region has been studied within the single collision model. Particle and energy reflection coefficients as functions of the scaled transport cross section have been calculated numerically by utilizing the exact scattering function for the Kr-C potential and analytically with an effective power approximation for the same potential. The obtained analytical formulae approximate very accurately to the numerical results. Comparison of the calculated reflection coefficients with the experimental data and computer simulations for different light ion-heavy target combinations shows that the scaled transport cross section remains a convenient scaling parameter in the single collision domain, as adopted previously in multiple collision theory

  4. Multiscale modeling and surgical planning for single ventricle heart patients

    Science.gov (United States)

    Marsden, Alison

    2011-11-01

    Single ventricle heart patients are among the most challenging for pediatric cardiologists to treat, and typically undergo a palliative course of three open-heart surgeries starting immediately after birth. We will present recent tools for modeling blood flow in single ventricle heart patients using a multiscale approach that couples a 3D Navier-Stokes domain to a 0D closed loop lumped parameter network comprised of circuit elements. This coupling allows us to capture the effect of changes in local geometry, such as shunt sizes, on global circulatory dynamics, such as cardiac output. A semi-implicit numerical method is formulated to solve the coupled system in which flow and pressure information is passed between the two domains at the inlets and outlets of the model. A finite element method with outflow stabilization is applied in the 3D Navier-Stokes domain, and the LPN system of ordinary differential equations is solved numerically using a Runge-Kutta method. These tools are coupled via automated scripts to a derivative-free optimization method. Optimization is used to systematically explore surgical designs using clinically relevant cost functions for two stages of single ventricle repair. First, we will present results from optimization of the first stage Blalock Taussig Shunt. Second, we will present results from optimization of a new Y-graft design for the third stage of single ventricle repair called the Fontan surgery. The Y-graft is shown, in simulations, to successfully improve hepatic flow distribution, a known clinical problem. Preliminary clinical experience with the Y-graft will be discussed.

  5. A self-organising model of market with single commodity

    Science.gov (United States)

    Chakraborti, Anirban; Pradhan, Srutarshi; Chakrabarti, Bikas K.

    2001-08-01

    We have studied here the self-organising features of the dynamics of a model market, where the agents ‘trade’ for a single commodity with their money. The model market consists of fixed numbers of economic agents, money supply and commodity. We demonstrate that the model, apart from showing a self-organising behaviour, indicates a crucial role for the money supply in the market and also its self-organising behaviour is seen to be significantly affected when the money supply becomes less than the optimum. We also observed that this optimal money supply level of the market depends on the amount of ‘frustration’ or scarcity in the commodity market.

  6. New Procedure to Develop Lumped Kinetic Models for Heavy Fuel Oil Combustion

    KAUST Repository

    Han, Yunqing

    2016-09-20

    A new procedure to develop accurate lumped kinetic models for complex fuels is proposed, and applied to the experimental data of the heavy fuel oil measured by thermogravimetry. The new procedure is based on the pseudocomponents representing different reaction stages, which are determined by a systematic optimization process to ensure that the separation of different reaction stages with highest accuracy. The procedure is implemented and the model prediction was compared against that from a conventional method, yielding a significantly improved agreement with the experimental data. © 2016 American Chemical Society.

  7. Procedure for Application of Software Reliability Growth Models to NPP PSA

    International Nuclear Information System (INIS)

    Son, Han Seong; Kang, Hyun Gook; Chang, Seung Cheol

    2009-01-01

    As the use of software increases at nuclear power plants (NPPs), the necessity for including software reliability and/or safety into the NPP Probabilistic Safety Assessment (PSA) rises. This work proposes an application procedure of software reliability growth models (RGMs), which are most widely used to quantify software reliability, to NPP PSA. Through the proposed procedure, it can be determined if a software reliability growth model can be applied to the NPP PSA before its real application. The procedure proposed in this work is expected to be very helpful for incorporating software into NPP PSA

  8. A single simple procedure for dewaxing, hydration and heat-induced epitope retrieval (HIER) for immunohistochemistry in formalin fixed paraffin-embedded tissue

    DEFF Research Database (Denmark)

    Paulsen, I M S; Dimke, H; Frische, S

    2015-01-01

    Heat-induced epitope retrieval (HIER) is widely used for immunohistochemistry on formalin fixed paraffin-embedded tissue and includes temperatures well above the melting point of paraffin. We therefore tested whether traditional xylene-based removal of paraffin is required on sections from paraffin...... of dewaxing in xylene. In conclusion, the HIER procedure described and tested can be used as a single procedure enabling dewaxing, hydration and epitope retrieval for immunohistochemistry in formalin fixed paraffin-embedded tissue....

  9. 78 FR 20148 - Reporting Procedure for Mathematical Models Selected To Predict Heated Effluent Dispersion in...

    Science.gov (United States)

    2013-04-03

    ... mathematical modeling methods used in predicting the dispersion of heated effluent in natural water bodies. The... COMMISSION Reporting Procedure for Mathematical Models Selected To Predict Heated Effluent Dispersion in... Mathematical Models Selected to Predict Heated Effluent Dispersion in Natural Water Bodies.'' The guide is...

  10. On the single-mass model of the vocal folds

    International Nuclear Information System (INIS)

    Howe, M S; McGowan, R S

    2010-01-01

    An analysis is made of the fluid-structure interactions necessary to support self-sustained oscillations of a single-mass mechanical model of the vocal folds subject to a nominally steady subglottal overpressure. The single-mass model of Fant and Flanagan is re-examined and an analytical representation of vortex shedding during 'voiced speech' is proposed that promotes cooperative, periodic excitation of the folds by the glottal flow. Positive feedback that sustains glottal oscillations is shown to occur during glottal contraction, when the flow separates from the 'trailing edge' of the glottis producing a low-pressure 'suction' force that tends to pull the folds together. Details are worked out for flow that can be regarded as locally two-dimensional in the glottal region. Predictions of free-streamline theory are used to model the effects of quasi-static variations in the separation point on the glottal wall. Numerical predictions are presented to illustrate the waveform of the sound radiated towards the mouth from the glottis. The theory is easily modified to include feedback on the glottal flow of standing acoustic waves, both in the vocal tract beyond the glottis and in the subglottal region. (invited paper)

  11. Generalized partially linear single-index model for zero-inflated count data.

    Science.gov (United States)

    Wang, Xiaoguang; Zhang, Jun; Yu, Liang; Yin, Guosheng

    2015-02-28

    Count data often arise in biomedical studies, while there could be a special feature with excessive zeros in the observed counts. The zero-inflated Poisson model provides a natural approach to accounting for the excessive zero counts. In the semiparametric framework, we propose a generalized partially linear single-index model for the mean of the Poisson component, the probability of zero, or both. We develop the estimation and inference procedure via a profile maximum likelihood method. Under some mild conditions, we establish the asymptotic properties of the profile likelihood estimators. The finite sample performance of the proposed method is demonstrated by simulation studies, and the new model is illustrated with a medical care dataset. Copyright © 2014 John Wiley & Sons, Ltd.

  12. Single-image-based Modelling Architecture from a Historical Photograph

    Science.gov (United States)

    Dzwierzynska, Jolanta

    2017-10-01

    Historical photographs are proved to be very useful to provide a dimensional and geometrical analysis of buildings as well as to generate 3D reconstruction of the whole structure. The paper addresses the problem of single historical photograph analysis and modelling of an architectural object from it. Especially, it focuses on reconstruction of the original look of New-Town synagogue from the single historic photograph, when camera calibration is completely unknown. Due to the fact that the photograph faithfully followed the geometric rules of perspective, it was possible to develop and apply the method to obtain a correct 3D reconstruction of the building. The modelling process consisted of a series of familiar steps: feature extraction, determination of base elements of perspective, dimensional analyses and 3D reconstruction. Simple formulas were proposed in order to estimate location of characteristic points of the building in 3D Cartesian system of axes on the base of their location in 2D Cartesian system of axes. The reconstruction process proceeded well, although slight corrections were necessary. It was possible to reconstruct the shape of the building in general, and two of its facades in detail. The reconstruction of the other two facades requires some additional information or the additional picture. The success of the presented reconstruction method depends on the geometrical content of the photograph as well as quality of the picture, which ensures the legibility of building edges. The presented method of reconstruction is a combination of the descriptive method of reconstruction and computer aid; therefore, it seems to be universal. It can prove useful for single-image-based modelling architecture.

  13. Gravity research on plants: use of single cell experimental models

    Directory of Open Access Journals (Sweden)

    Youssef eChebli

    2011-09-01

    Full Text Available Future space missions and implementation of permanent bases on Moon and Mars will greatly depend on the availability of ambient air and sustainable food supply. Therefore, understanding the effects of altered gravity conditions on plant metabolism and growth is vital for space missions and extra-terrestrial human existence. In this mini-review we summarize how plant cells are thought to perceive changes in magnitude and orientation of the gravity vector. The particular advantages of several single celled model systems for gravity research are explored and an overview over recent advancements and potential use of these systems is provided.

  14. Linear dynamic models for classification of single-trial EEG.

    Science.gov (United States)

    Samdin, S Balqis; Ting, Chee-Ming; Salleh, Sh-Hussain; Ariff, A K; Mohd Noor, A B

    2013-01-01

    This paper investigates the use of linear dynamic models (LDMs) to improve classification of single-trial EEG signals. Existing dynamic classification of EEG uses discrete-state hidden Markov models (HMMs) based on piecewise-stationary assumption, which is inadequate for modeling the highly non-stationary dynamics underlying EEG. The continuous hidden states of LDMs could better describe this continuously changing characteristic of EEG, and thus improve the classification performance. We consider two examples of LDM: a simple local level model (LLM) and a time-varying autoregressive (TVAR) state-space model. AR parameters and band power are used as features. Parameter estimation of the LDMs is performed by using expectation-maximization (EM) algorithm. We also investigate different covariance modeling of Gaussian noises in LDMs for EEG classification. The experimental results on two-class motor-imagery classification show that both types of LDMs outperform the HMM baseline, with the best relative accuracy improvement of 14.8% by LLM with full covariance for Gaussian noises. It may due to that LDMs offer more flexibility in fitting the underlying dynamics of EEG.

  15. FUSED KERNEL-SPLINE SMOOTHING FOR REPEATEDLY MEASURED OUTCOMES IN A GENERALIZED PARTIALLY LINEAR MODEL WITH FUNCTIONAL SINGLE INDEX.

    Science.gov (United States)

    Jiang, Fei; Ma, Yanyuan; Wang, Yuanjia

    We propose a generalized partially linear functional single index risk score model for repeatedly measured outcomes where the index itself is a function of time. We fuse the nonparametric kernel method and regression spline method, and modify the generalized estimating equation to facilitate estimation and inference. We use local smoothing kernel to estimate the unspecified coefficient functions of time, and use B-splines to estimate the unspecified function of the single index component. The covariance structure is taken into account via a working model, which provides valid estimation and inference procedure whether or not it captures the true covariance. The estimation method is applicable to both continuous and discrete outcomes. We derive large sample properties of the estimation procedure and show different convergence rate of each component of the model. The asymptotic properties when the kernel and regression spline methods are combined in a nested fashion has not been studied prior to this work even in the independent data case.

  16. Modeling bacterial population growth from stochastic single-cell dynamics.

    Science.gov (United States)

    Alonso, Antonio A; Molina, Ignacio; Theodoropoulos, Constantinos

    2014-09-01

    A few bacterial cells may be sufficient to produce a food-borne illness outbreak, provided that they are capable of adapting and proliferating on a food matrix. This is why any quantitative health risk assessment policy must incorporate methods to accurately predict the growth of bacterial populations from a small number of pathogens. In this aim, mathematical models have become a powerful tool. Unfortunately, at low cell concentrations, standard deterministic models fail to predict the fate of the population, essentially because the heterogeneity between individuals becomes relevant. In this work, a stochastic differential equation (SDE) model is proposed to describe variability within single-cell growth and division and to simulate population growth from a given initial number of individuals. We provide evidence of the model ability to explain the observed distributions of times to division, including the lag time produced by the adaptation to the environment, by comparing model predictions with experiments from the literature for Escherichia coli, Listeria innocua, and Salmonella enterica. The model is shown to accurately predict experimental growth population dynamics for both small and large microbial populations. The use of stochastic models for the estimation of parameters to successfully fit experimental data is a particularly challenging problem. For instance, if Monte Carlo methods are employed to model the required distributions of times to division, the parameter estimation problem can become numerically intractable. We overcame this limitation by converting the stochastic description to a partial differential equation (backward Kolmogorov) instead, which relates to the distribution of division times. Contrary to previous stochastic formulations based on random parameters, the present model is capable of explaining the variability observed in populations that result from the growth of a small number of initial cells as well as the lack of it compared to

  17. Theoretical modelling and experimental investigation of single-phase and two-phase flow division at a tee-junction

    International Nuclear Information System (INIS)

    Lemonnier, H.; Hervieu, E.

    1991-01-01

    Phase separation in a tee-junction is modelled in the particular case of bubbly-flow. The model is based on a two-dimensional approach and hence, uses local equations. The first step consists in modelling the single-phase flow in the tee-junction. The free streamline theory is used to predict the flow of the continuous phase. The two recirculation zones which are presented in this case are predicted by the model. The second step consists in predicting the gas bubble paths as a result of the actions of the single-phase flow. Finally, the trajectories of gas bubbles are used to predict the separation characteristics of the tee-junction. Each step of the modelling procedure has been carefully tested by an in-depth experimental investigation. Excellent quantitative agreement is obtained between experimental results and model predictions. Moreover, the phase separation phenomenon is found to be clearly described by the model. (orig.)

  18. Automatic Multi-Scale Calibration Procedure for Nested Hydrological-Hydrogeological Regional Models

    Science.gov (United States)

    Labarthe, B.; Abasq, L.; Flipo, N.; de Fouquet, C. D.

    2014-12-01

    Large hydrosystem modelling and understanding is a complex process depending on regional and local processes. A nested interface concept has been implemented in the hydrosystem modelling platform for a large alluvial plain model (300 km2) part of a 11000 km2 multi-layer aquifer system, included in the Seine basin (65000 km2, France). The platform couples hydrological and hydrogeological processes through four spatially distributed modules (Mass balance, Unsaturated Zone, River and Groundwater). An automatic multi-scale calibration procedure is proposed. Using different data sets from regional scale (117 gauging stations and 183 piezometers over the 65000 km2) to the intermediate scale(dense past piezometric snapshot), it permits the calibration and homogenization of model parameters over scales.The stepwise procedure starts with the optimisation of the water mass balance parameters at regional scale using a conceptual 7 parameters bucket model coupled with the inverse modelling tool PEST. The multi-objective function is derived from river discharges and their de-composition by hydrograph separation. The separation is performed at each gauging station using an automatic procedure based one Chapman filter. Then, the model is run at the regional scale to provide recharge estimate and regional fluxes to the groundwater local model. Another inversion method is then used to determine the local hydrodynamic parameters. This procedure used an initial kriged transmissivity field which is successively updated until the simulated hydraulic head distribution equals a reference one obtained by krigging. Then, the local parameters are upscaled to the regional model by renormalisation procedure.This multi-scale automatic calibration procedure enhances both the local and regional processes representation. Indeed, it permits a better description of local heterogeneities and of the associated processes which are transposed into the regional model, improving the overall performances

  19. A Procedure for Building Product Models in Intelligent Agent-based OperationsManagement

    DEFF Research Database (Denmark)

    Hvam, Lars; Riis, Jesper; Malis, Martin

    2003-01-01

    This article presents a procedure for building product models to support the specification processes dealing with sales, design of product variants and production preparation. The procedure includes, as the first phase, an analysis and redesign of the business processes that are to be supported...... by product models. The next phase includes an analysis of the product assortment, and the set up of a so-called product master. Finally the product model is designed and implemented by using object oriented modelling. The procedure is developed in order to ensure that the product models constructed are fit...... for the business processes they support, and properly structured and documented in order to facilitate the maintenance and further development of the systems. The research has been carried out at the Centre for Industrialisation of Engineering, Department of Manufacturing Engineering, Technical University...

  20. Modeling of a single-phase photovoltaic inverter

    Energy Technology Data Exchange (ETDEWEB)

    Maris, T.I. [Department of Electrical Engineering, Technological Educational Institute of Chalkida, 334 40 Psachna Evias (Greece); Kourtesi, St. [Hellenic Public Power Corporation S.A., 22 Chalcocondyli Str., 104 32 Athens (Greece); Ekonomou, L. [Hellenic American University, 12 Kaplanon Str., 106 80 Athens (Greece); Fotis, G.P. [National Technical University of Athens, School of Electrical and Computer Engineering, High Voltage Laboratory, 9 Iroon Politechniou St., Zografou, 157 80 Athens (Greece)

    2007-11-06

    The paper presents the design of a single-phase photovoltaic inverter model and the simulation of its performance. Furthermore, the concept of moving real and reactive power after coupling this inverter model with an a.c. source representing the main power distribution grid was studied. Brief technical information is given on the inverter design, with emphasis on the operation of the circuit used. In the technical information section, a description of real and reactive power components is given with special reference to the control of these power components by controlling the power angle or the difference in voltage magnitudes between two voltage sources. This a.c. converted voltage has practical interest, since it is useful for feeding small house appliances. (author)

  1. On the predictiveness of single-field inflationary models

    Science.gov (United States)

    Burgess, C. P.; Patil, Subodh P.; Trott, Michael

    2014-06-01

    We re-examine the predictiveness of single-field inflationary models and discuss how an unknown UV completion can complicate determining inflationary model parameters from observations, even from precision measurements. Besides the usual naturalness issues associated with having a shallow inflationary potential, we describe another issue for inflation, namely, unknown UV physics modifies the running of Standard Model (SM) parameters and thereby introduces uncertainty into the potential inflationary predictions. We illustrate this point using the minimal Higgs Inflationary scenario, which is arguably the most predictive single-field model on the market, because its predictions for A S , r and n s are made using only one new free parameter beyond those measured in particle physics experiments, and run up to the inflationary regime. We find that this issue can already have observable effects. At the same time, this UV-parameter dependence in the Renormalization Group allows Higgs Inflation to occur (in principle) for a slightly larger range of Higgs masses. We comment on the origin of the various UV scales that arise at large field values for the SM Higgs, clarifying cut off scale arguments by further developing the formalism of a non-linear realization of SU L (2) × U(1) in curved space. We discuss the interesting fact that, outside of Higgs Inflation, the effect of a non-minimal coupling to gravity, even in the SM, results in a non-linear EFT for the Higgs sector. Finally, we briefly comment on post BICEP2 attempts to modify the Higgs Inflation scenario.

  2. Simultaneous resection for colorectal cancer with synchronous liver metastases is a safe procedure: Outcomes at a single center in Turkey.

    Science.gov (United States)

    Dulundu, Ender; Attaallah, Wafi; Tilki, Metin; Yegen, Cumhur; Coskun, Safak; Coskun, Mumin; Erdim, Aylin; Tanrikulu, Eda; Yardimci, Samet; Gunal, Omer

    2017-05-23

    The optimal surgical strategy for treating colorectal cancer with synchronous liver metastases is subject to debate. The current study sought to evaluate the outcomes of simultaneous colorectal cancer and liver metastases resection in a single center. Prospectively collected data on all patients with synchronous colorectal liver metastases who underwent simultaneous resection with curative intent were analyzed retrospectively. Patient outcomes were compared depending on the primary tumor location and type of liver resection (major or minor). Between January 2005 and August 2016, 108 patients underwent simultaneous resection of primary colorectal cancer and liver metastases. The tumor was localized to the right side of the colon in 24 patients (22%), to the left side in 40 (37%), and to the rectum in 44 (41%). Perioperative mortality occurred in 3 patients (3%). Postoperative complications were noted in 32 patients (30%), and most of these complications (75%) were grade 1 to 3 according to the Clavien-Dindo classification. Neither perioperative mortality nor the rate of postoperative complications after simultaneous resection differed among patients with cancer of the right side of the colon, those with cancer of the left side of the colon, and those with rectal cancer (4%, 2.5%, and 2%, respectively, p = 0.89) and (17%, 33%, and 34%, respectively; p = 0.29)]. The 5-year overall survival of the entire sample was 54% and the 3-year overall survival was 67 %. In conclusion, simultaneous resection for primary colorectal cancer and liver metastases is a safe procedure and can be performed without excess morbidity in carefully selected patients regardless of the location of the primary tumor and type of hepatectomy.

  3. A spectral geometric model for Compton single scatter in PET based on the single scatter simulation approximation

    Science.gov (United States)

    Kazantsev, I. G.; Olsen, U. L.; Poulsen, H. F.; Hansen, P. C.

    2018-02-01

    We investigate the idealized mathematical model of single scatter in PET for a detector system possessing excellent energy resolution. The model has the form of integral transforms estimating the distribution of photons undergoing a single Compton scattering with a certain angle. The total single scatter is interpreted as the volume integral over scatter points that constitute a rotation body with a football shape, while single scattering with a certain angle is evaluated as the surface integral over the boundary of the rotation body. The equations for total and sample single scatter calculations are derived using a single scatter simulation approximation. We show that the three-dimensional slice-by-slice filtered backprojection algorithm is applicable for scatter data inversion provided that the attenuation map is assumed to be constant. The results of the numerical experiments are presented.

  4. Monte Carlo simulations of lattice models for single polymer systems

    International Nuclear Information System (INIS)

    Hsu, Hsiao-Ping

    2014-01-01

    Single linear polymer chains in dilute solutions under good solvent conditions are studied by Monte Carlo simulations with the pruned-enriched Rosenbluth method up to the chain length N∼O(10 4 ). Based on the standard simple cubic lattice model (SCLM) with fixed bond length and the bond fluctuation model (BFM) with bond lengths in a range between 2 and √(10), we investigate the conformations of polymer chains described by self-avoiding walks on the simple cubic lattice, and by random walks and non-reversible random walks in the absence of excluded volume interactions. In addition to flexible chains, we also extend our study to semiflexible chains for different stiffness controlled by a bending potential. The persistence lengths of chains extracted from the orientational correlations are estimated for all cases. We show that chains based on the BFM are more flexible than those based on the SCLM for a fixed bending energy. The microscopic differences between these two lattice models are discussed and the theoretical predictions of scaling laws given in the literature are checked and verified. Our simulations clarify that a different mapping ratio between the coarse-grained models and the atomistically realistic description of polymers is required in a coarse-graining approach due to the different crossovers to the asymptotic behavior

  5. Evaluation of aesthetics of implant-supported single-tooth replacements using different bone augmentation procedures : A prospective randomized clinical study

    NARCIS (Netherlands)

    Meijndert, Leo; Meijer, Henny J. A.; Stellingsma, Kees; Stegenga, Boudewijn; Raghoebar, Gerry M.

    2007-01-01

    Objectives: The aim of this study was to evaluate the aesthetics of implant-supported single-tooth replacements using different augmentation procedures in a prospective study with the use of an objective rating index and with a subjective patient questionnaire, and to compare the results with each

  6. Comparison of procedures for immediate reconstruction of large osseous defects resulting from removal of a single tooth to prepare for insertion of an endosseous implant after healing

    NARCIS (Netherlands)

    Raghoebar, G. M.; Slater, J. J. H.; den Hartog, L.; Meijer, H. J. A.; Vissink, A.

    This study evaluated the treatment outcome of immediate reconstruction of 45 large osseous defects resulting from removal of a single tooth with a 1:2 mixture of Bio-Oss(R) and autologous tuberosity bone, and three different procedures for soft tissue closing (Bio-Gide(R) membrane, connective tissue

  7. Clinical and radiologic evaluation of 2-stage IMZ implants placed in a single-stage procedure : 2-year results of a prospective comparative study

    NARCIS (Netherlands)

    Heydenrijk, K; Raghoebar, GM; Meijer, HJA; Stegenga, B

    2003-01-01

    Purpose: The aim of this study was to evaluate the feasibility of using a 2-stage implant system in a single-stage procedure and to study the impact of the microgap between the implant and the abutment. Materials and Methods: Sixty edentulous patients (Cawood class V or VI) participated in this

  8. MATHEMATICAL MODELING OF FLOW PARAMETERS FOR SINGLE WIND TURBINE

    Directory of Open Access Journals (Sweden)

    2016-01-01

    Full Text Available It is known that on the territory of the Russian Federation the construction of several large wind farms is planned. The tasks connected with design and efficiency evaluation of wind farm work are in demand today. One of the possible directions in design is connected with mathematical modeling. The method of large eddy simulation developed within the direction of computational hydrodynamics allows to reproduce unsteady structure of the flow in details and to determine various integrated values. The calculation of work for single wind turbine installation by means of large eddy simulation and Actuator Line Method along the turbine blade is given in this work. For problem definition the numerical method in the form of a box was considered and the adapted unstructured grid was used.The mathematical model included the main equations of continuity and momentum equations for incompressible fluid. The large-scale vortex structures were calculated by means of integration of the filtered equations. The calculation was carried out with Smagorinsky model for determination of subgrid scale turbulent viscosity. The geometrical parametersof wind turbine were set proceeding from open sources in the Internet.All physical values were defined at center of computational cell. The approximation of items in equations was ex- ecuted with the second order of accuracy for time and space. The equations for coupling velocity and pressure were solved by means of iterative algorithm PIMPLE. The total quantity of the calculated physical values on each time step was equal to 18. So, the resources of a high performance cluster were required.As a result of flow calculation in wake for the three-bladed turbine average and instantaneous values of velocity, pressure, subgrid kinetic energy and turbulent viscosity, components of subgrid stress tensor were worked out. The re- ceived results matched the known results of experiments and numerical simulation, testify the opportunity

  9. Present State of the Single and Twin Aperture Short Dipole Model Program for the LHC

    CERN Document Server

    Andreyev, N I; Kurtyka, T; Leroy, D; Oberli, L R; Perini, D; Russenschuck, Stephan; Siegel, N; Siemko, A; Tommasini, D; Vanenkov, I; Walckiers, L; Weterings, W

    1998-01-01

    The LHC model program for main dipoles is based on the design, fabrication and testing at CERN of a number of single and twin aperture 1m long magnets. So far, a number of single aperture models, each with specific characteristics, were tested at 2 K at a rate of about one per month. These magnets are the main tool used to check coil performance as a function of design and assembly options in view of optimizing and finalizing choices of components and procedures. Initial quenching field levels of 8.8 T were obtained and the short sample limit of the cable at 1.9 K was reached corresponding to a central bore field of 10 T. A few twin aperture dipole models were also built and tested, using the same structural components as for the long magnets which are now being built in industry. The paper discusses the main characteristics of the models built so far, the instrumentation developed to date and the experience obtained. Finally it describes the plans aimed at continuing a vigorous program to provide input to th...

  10. Modeling bidirectionally coupled single-mode semiconductor lasers

    International Nuclear Information System (INIS)

    Mulet, Josep; Masoller, Cristina; Mirasso, Claudio R.

    2002-01-01

    We develop a dynamical model suitable for the description of two mutually coupled semiconductor lasers in a face-to-face configuration. Our study considers the propagation of the electric field along the compound system as well as the evolution of the carrier densities within each semiconductor laser. Mutual injection, passive optical feedback, and multiple reflections are accounted for in this framework, although under weak to moderate coupling conditions. We systematically describe the effect of the coupling strength on the spectrum of monochromatic solutions and on the respective dynamical behavior. By assuming single-longitudinal-mode operation, weak mutual coupling and slowly varying approximation, the dynamical model can be reduced to rate equations describing the mutual injection from one laser to its counterpart and vice versa. A good agreement between the complete and simplified models is found for small coupling. For larger coupling, higher-order terms lead to a smaller threshold reduction, reflected itself in the spectrum of the monochromatic solutions and in the dynamics of the optical power

  11. Model Based Control of Single-Phase Marine Cooling Systems

    DEFF Research Database (Denmark)

    Hansen, Michael

    2014-01-01

    these systems. Traditionally, control for this type of cooling system has been limited to open-loop control of pumps combined with a couple of local PID controllers for bypass valves to keep critical temperatures within design limits. This research considers improvements in a retrofit framework to the control...... linearization, an H∞-control design is applied to the resulting linear system. Disturbance rejection capabilities and robustness of performance for this control design methodology is compared to a baseline design derived from classical control theory. This shows promising results for the nonlinear robust design......This thesis is concerned with the problem of designing model-based control for a class of single-phase marine cooling systems. While this type of cooling system has been in existence for several decades, it is only recently that energy efficiency has become a focus point in the design and operation...

  12. A phenomenological model for particle retention in single, saturated fractures.

    Science.gov (United States)

    Rodrigues, Sandrina; Dickson, Sarah

    2014-01-01

    Fractured aquifers are some of the most poorly characterized subsurface environments despite posing one of the highest risks to the protection of potable groundwater. This research was designed to improve the understanding of the factors affecting particle transport through fractures by developing a phenomenological model based on laboratory-scale transport data. The model presented in this research employed data from over 70 particle tracer tests conducted in single, saturated, variable-aperture fractures that were obtained from the natural environment and fractured in the laboratory or cast from epoxy in the laboratory. The particles employed were Escherichia coli RS2-GFP and microspheres. The tracer experiments were conducted in natural (dolomitic limestone and granite) as well as epoxy replicas of the natural fractures. The multiple linear regression analysis revealed that the most important factors influencing particle retention in fractures are the ratio of the ionic strength of solution to collector charge, the ratio of particle to collector charge, and the ratio of advective to diffusive forces as described by the Peclet number. The model was able to reasonably (R(2)  = 0.64) predict the fraction of particles retained; however, it is evident that some factors not accounted for in the model also contributed to retention. This research presents a novel approach to understanding particle transport in fractures, and illustrates the relative importance of various factors affecting the transport mechanisms. The utility of this model lies in the increased understanding of particle transport in fractures, which is extremely useful for directing future research. © 2013, National Ground Water Association.

  13. The Chain-Link Fence Model: A Framework for Creating Security Procedures

    OpenAIRE

    Houghton, Robert F.

    2013-01-01

    A long standing problem in information technology security is how to help reduce the security footprint. Many specific proposals exist to address specific problems in information technology security. Most information technology solutions need to be repeatable throughout the course of an information systems lifecycle. The Chain-Link Fence Model is a new model for creating and implementing information technology procedures. This model was validated by two different methods: the first being int...

  14. A Markov Chain Model for evaluating the effectiveness of randomized surveillance procedures

    Energy Technology Data Exchange (ETDEWEB)

    Edmunds, T.A.

    1994-01-01

    A Markov Chain Model has been developed to evaluate the effectiveness of randomized surveillance procedures. The model is applicable for surveillance systems that monitor a collection of assets by randomly selecting and inspecting the assets. The model provides an estimate of the detection probability as a function of the amount of time that an adversary would require to steal or sabotage the asset. An interactive computer code has been written to perform the necessary computations.

  15. A network society communicative model for optimizing the Refugee Status Determination (RSD procedures

    Directory of Open Access Journals (Sweden)

    Andrea Pacheco Pacífico

    2013-01-01

    Full Text Available This article recommends a new way to improve Refugee Status Determination (RSD procedures by proposing a network society communicative model based on active involvement and dialogue among all implementing partners. This model, named after proposals from Castells, Habermas, Apel, Chimni, and Betts, would be mediated by the United Nations High Commissioner for Refugees (UNHCR, whose role would be modeled after that of the International Committee of the Red Cross (ICRC practice.

  16. Physics-Based Crystal Plasticity Modeling of Single Crystal Niobium

    Science.gov (United States)

    Maiti, Tias

    Crystal plasticity models based on thermally activated dislocation kinetics has been successful in predicting the deformation behavior of crystalline materials, particularly in face-centered cubic (fcc) metals. In body-centered cubic (bcc) metals success has been limited owing to ill-defined slip planes. The flow stress of a bcc metal is strongly dependent on temperature and orientation due to the non-planar splitting of a/2 screw dislocations. As a consequence of this, bcc metals show two unique deformation characteristics: (a) thermally-activated glide of screw dislocations--the motion of screw components with their non-planar core structure at the atomistic level occurs even at low stress through the nucleation (assisted by thermal activation) and lateral propagation of dislocation kink pairs; (b) break-down of the Schmid Law, where dislocation slip is driven only by the resolved shear stress. Since the split dislocation core has to constrict for a kink pair formation (and propagation), the non-planarity of bcc screw dislocation cores entails an influence of (shear) stress components acting on planes other than the primary glide plane on their mobility. Another consequence of the asymmetric core splitting on the glide plane is a direction-sensitive slip resistance, which is termed twinning/atwinning sense of shear and should be taken into account when developing constitutive models. Modeling thermally-activated flow including the above-mentioned non-Schmid effects in bcc metals has been the subject of much work, starting in the 1980s and gaining increased interest in recent times. The majority of these works focus on single crystal deformation of commonly used metals such as Iron (Fe), Molybdenum (Mo), and Tungsten (W), while very few published studies address deformation behavior in Niobium (Nb). Most of the work on Nb revolves around fitting parameters of phenomenological descriptions, which do not capture adequately the macroscopic multi-stage hardening

  17. Implementation of a combined association-linkage model for quantitative traits in linear mixed model procedures of statistical packages

    NARCIS (Netherlands)

    Beem, A. Leo; Boomsma, Dorret I.

    2006-01-01

    A transmission disequilibrium test for quantitative traits which combines association and linkage analyses is currently available in several dedicated software packages. We describe how to implement such models in linear mixed model procedures that are available in widely used statistical packages

  18. Primordial black holes from single field models of inflation

    CERN Document Server

    Garcia-Bellido, Juan

    Primordial black holes (PBH) have been shown to arise from high peaks in the matter power spectra of multi-field models of inflation. Here we show, with a simple toy model, that it is also possible to generate a peak in the curvature power spectrum of single-field inflation. We assume that the effective dynamics of the inflaton field presents a near-inflection point which slows down the field right before the end of inflation and gives rise to a prominent spike in the fluctuation power spectrum at scales much smaller than those probed by Cosmic Microwave Background (CMB) and Large Scale Structure (LSS) observations. This peak will give rise, upon reentry during the radiation era, to PBH via gravitational collapse. The mass and abundance of these PBH is such that they could constitute the totality of the Dark Matter today. We satisfy all CMB and LSS constraints and predict a very broad range of PBH masses. Some of these PBH are light enough that they will evaporate before structure formation, leaving behind a ...

  19. Modelling Single Tree Structure with Terrestrial Laser Scanner

    Science.gov (United States)

    Yurtseven, H.; Akgül, M.; Gülci, S.

    2017-11-01

    Recent technological developments, which has reliable accuracy and quality for all engineering works, such as remote sensing tools have wide range use in forestry applications. Last decade, sustainable use and management opportunities of forest resources are favorite topics. Thus, precision of obtained data plays an important role in evaluation of current status of forests' value. The use of aerial and terrestrial laser technology has more reliable and effective models to advance the appropriate natural resource management. This study investigates the use of terrestrial laser scanner (TLS) technology in forestry, and also the methodological data processing stages for tree volume extraction is explained. Z+F Imager 5010C TLS system was used for measure single tree information such as tree height, diameter of breast height, branch volume and canopy closure. In this context more detailed and accurate data can be obtained than conventional inventory sampling in forestry by using TLS systems. However the accuracy of obtained data is up to the experiences of TLS operator in the field. Number of scan stations and its positions are other important factors to reduce noise effect and accurate 3D modelling. The results indicated that the use of point cloud data to extract tree information for forestry applications are promising methodology for precision forestry.

  20. Analyzing longitudinal data with the linear mixed models procedure in SPSS.

    Science.gov (United States)

    West, Brady T

    2009-09-01

    Many applied researchers analyzing longitudinal data share a common misconception: that specialized statistical software is necessary to fit hierarchical linear models (also known as linear mixed models [LMMs], or multilevel models) to longitudinal data sets. Although several specialized statistical software programs of high quality are available that allow researchers to fit these models to longitudinal data sets (e.g., HLM), rapid advances in general purpose statistical software packages have recently enabled analysts to fit these same models when using preferred packages that also enable other more common analyses. One of these general purpose statistical packages is SPSS, which includes a very flexible and powerful procedure for fitting LMMs to longitudinal data sets with continuous outcomes. This article aims to present readers with a practical discussion of how to analyze longitudinal data using the LMMs procedure in the SPSS statistical software package.

  1. Multiple single nucleotide polymorphism analysis using penalized regression in nonlinear mixed-effect pharmacokinetic models.

    Science.gov (United States)

    Bertrand, Julie; Balding, David J

    2013-03-01

    Studies on the influence of single nucleotide polymorphisms (SNPs) on drug pharmacokinetics (PK) have usually been limited to the analysis of observed drug concentration or area under the concentration versus time curve. Nonlinear mixed effects models enable analysis of the entire curve, even for sparse data, but until recently, there has been no systematic method to examine the effects of multiple SNPs on the model parameters. The aim of this study was to assess different penalized regression methods for including SNPs in PK analyses. A total of 200 data sets were simulated under both the null and an alternative hypothesis. In each data set for each of the 300 participants, a PK profile at six sampling times was simulated and 1227 genotypes were generated through haplotypes. After modelling the PK profiles using an expectation maximization algorithm, genetic association with individual parameters was investigated using the following approaches: (i) a classical stepwise approach, (ii) ridge regression modified to include a test, (iii) Lasso and (iv) a generalization of Lasso, the HyperLasso. Penalized regression approaches are often much faster than the stepwise approach. There are significantly fewer true positives for ridge regression than for the stepwise procedure and HyperLasso. The higher number of true positives in the stepwise procedure was accompanied by a higher count of false positives (not significant). We find that all approaches except ridge regression show similar power, but penalized regression can be much less computationally demanding. We conclude that penalized regression should be preferred over stepwise procedures for PK analyses with a large panel of genetic covariates.

  2. Procedural 3d Modelling for Traditional Settlements. The Case Study of Central Zagori

    Science.gov (United States)

    Kitsakis, D.; Tsiliakou, E.; Labropoulos, T.; Dimopoulou, E.

    2017-02-01

    Over the last decades 3D modelling has been a fast growing field in Geographic Information Science, extensively applied in various domains including reconstruction and visualization of cultural heritage, especially monuments and traditional settlements. Technological advances in computer graphics, allow for modelling of complex 3D objects achieving high precision and accuracy. Procedural modelling is an effective tool and a relatively novel method, based on algorithmic modelling concept. It is utilized for the generation of accurate 3D models and composite facade textures from sets of rules which are called Computer Generated Architecture grammars (CGA grammars), defining the objects' detailed geometry, rather than altering or editing the model manually. In this paper, procedural modelling tools have been exploited to generate the 3D model of a traditional settlement in the region of Central Zagori in Greece. The detailed geometries of 3D models derived from the application of shape grammars on selected footprints, and the process resulted in a final 3D model, optimally describing the built environment of Central Zagori, in three levels of Detail (LoD). The final 3D scene was exported and published as 3D web-scene which can be viewed with 3D CityEngine viewer, giving a walkthrough the whole model, same as in virtual reality or game environments. This research work addresses issues regarding textures' precision, LoD for 3D objects and interactive visualization within one 3D scene, as well as the effectiveness of large scale modelling, along with the benefits and drawbacks that derive from procedural modelling techniques in the field of cultural heritage and more specifically on 3D modelling of traditional settlements.

  3. What basic clinical procedures should be mastered by junior clerkship students? Experience at a single medical school in Tanzania

    Directory of Open Access Journals (Sweden)

    Konje ET

    2016-03-01

    Full Text Available Eveline T Konje,1,2 Rodrick Kabangila,2,3 Mange Manyama,2,4 Jacqueline M van Wyk2,5 1Department of Epidemiology and Biostatistics, School of Public Health, Catholic University of Health and Allied Sciences, Mwanza, Tanzania; 2Medical Education Fellowship, Southern Africa FAIMER Regional Institute – SAFRI, Cape Town, South Africa; 3Department of Internal Medicine, 4Department of Anatomy and Cell Biology, School of Medicine, Catholic University of Health and Allied Sciences, Mwanza, Tanzania; 5Department of Clinical and Professional Education, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa Background: Clinical training in most medical schools, including the Catholic University of Health and Allied Sciences (CUHAS, is offered in the form of junior and senior rotations. During these clinical rotations, students are expected to acquire and master the basic procedural skills. However, students’ learning process should be evaluated for quality improvement. Objectives: This study was conducted to identify the basic medical procedural skills that third-year medical students should acquire and master and determine the level of students’ exposure on these procedures at the end of junior rotation in internal medicine. Identification of the gap between clinicians’ opinions, skills practiced by students, and third-year students’ curriculum in the medical department at CUHAS was also done. Methods: The descriptive cross-sectional study was used to collect data through a self-administered, structured questionnaire from clinicians in medicine. A review of logbooks was considered to determine level of students’ exposure, and a document analysis was done using existing medical curriculum. Results: The response of 71% (n=22 was obtained. Clinicians agreed on basic procedures that students should perform independently (ie, Foley catheter insertion, venipuncture, and intravenous drip insertion. Clinicians thought

  4. An incremental procedure model for e-learning projects at universities

    Directory of Open Access Journals (Sweden)

    Pahlke, Friedrich

    2006-11-01

    Full Text Available E-learning projects at universities are produced under different conditions than in industry. The main characteristic of many university projects is that these are realized quasi in a solo effort. In contrast, in private industry the different, interdisciplinary skills that are necessary for the development of e-learning are typically supplied by a multimedia agency.A specific procedure tailored for the use at universities is therefore required to facilitate mastering the amount and complexity of the tasks.In this paper an incremental procedure model is presented, which describes the proceeding in every phase of the project. It allows a high degree of flexibility and emphasizes the didactical concept – instead of the technical implementation. In the second part, we illustrate the practical use of the theoretical procedure model based on the project “Online training in Genetic Epidemiology”.

  5. Descriptive models for single-jet sluicing of sludge waste

    International Nuclear Information System (INIS)

    Erian, F.F.; Mahoney, L.A.; Terrones, G.

    1997-12-01

    Mobilization of sludge waste stored in underground storage tanks can be achieved safely and reliably by sluicing. In the project discussed in this report, the waste in Hanford single-shell Tank 241-C-106 will be mobilized by sluicing, retrieved by a slurry retrieval pump, and transferred via an 1800-ft slurry pipeline to Tank 241-AY-102. A sluicing strategy must be developed that ensures efficient use of the deployed configuration of the sluicing system: the nozzle(s) and the retrieval pump(s). Given a sluicing system configuration in a particular tank, it is desirable to prescribe the sequential locations at which the sludge will be mobilized and retrieved and the rate at which these mobilization and retrieval processes take place. In addition, it is necessary to know whether the retrieved waste slurry meets the requirements for cross-site slurry transport. Some of the physical phenomena that take place during mobilization and retrieval and certain aspects of the sluicing process are described in this report. First, a mathematical model gives (1) an idealized geometrical representation of where, within the confines of a storage tank containing a certain amount of settled waste, sludge can be removed and mobilized; and (2) a quantitative measure of the amount of sludge that can be removed during a sluicing campaign. A model describing an idealized water jet issuing from a circular nozzle located at a given height above a flat surface is also presented in this report. This dynamic water-jet model provides the basis for improving the geometrical sluicing model presented next. In this model the authors assume that the water jet follows a straight trajectory toward a target point on a flat surface. However, the water jet does not follow a straight line in the actual tank, and using the true trajectory will allow a more accurate estimate of the amount of disturbed material. Also, the authors hope that developing accurate force and pressure fields will lead to a better

  6. Exploring into the New Model Procedure in Translation: Wafting as a Case in Point

    Science.gov (United States)

    Akbari, Alireza

    2013-01-01

    Choosing the near equivalence for translator is of great concern nowadays. While it seems more commitment has been given to this issue, yet there are still rooms for more attention to innovative methods of Translation Studies in this direction. The idea of wafting procedure in Intermediacy model of translation comes from a book by Alireza Akbari…

  7. User Acceptance of YouTube for Procedural Learning: An Extension of the Technology Acceptance Model

    Science.gov (United States)

    Lee, Doo Young; Lehto, Mark R.

    2013-01-01

    The present study was framed using the Technology Acceptance Model (TAM) to identify determinants affecting behavioral intention to use YouTube. Most importantly, this research emphasizes the motives for using YouTube, which is notable given its extrinsic task goal of being used for procedural learning tasks. Our conceptual framework included two…

  8. A computational model to investigate assumptions in the headturn preference procedure

    NARCIS (Netherlands)

    Bergmann, C.; Bosch, L.F.M. ten; Fikkert, J.P.M.; Boves, L.W.J.

    2013-01-01

    In this paper we use a computational model to investigate four assumptions that are tacitly present in interpreting the results of studies on infants' speech processing abilities using the Headturn Preference Procedure (HPP): (1) behavioral differences originate in different processing; (2)

  9. The Psychology Department Model Advisement Procedure: A Comprehensive, Systematic Approach to Career Development Advisement

    Science.gov (United States)

    Howell-Carter, Marya; Nieman-Gonder, Jennifer; Pellegrino, Jennifer; Catapano, Brittani; Hutzel, Kimberly

    2016-01-01

    The MAP (Model Advisement Procedure) is a comprehensive, systematic approach to developmental student advisement. The MAP was implemented to improve advisement consistency, improve student preparation for internships/senior projects, increase career exploration, reduce career uncertainty, and, ultimately, improve student satisfaction with the…

  10. Conceptualizing and Testing Random Indirect Effects and Moderated Mediation in Multilevel Models: New Procedures and Recommendations

    Science.gov (United States)

    Bauer, Daniel J.; Preacher, Kristopher J.; Gil, Karen M.

    2006-01-01

    The authors propose new procedures for evaluating direct, indirect, and total effects in multilevel models when all relevant variables are measured at Level 1 and all effects are random. Formulas are provided for the mean and variance of the indirect and total effects and for the sampling variances of the average indirect and total effects.…

  11. A new experimental procedure for incorporation of model contaminants in polymer hosts

    NARCIS (Netherlands)

    Papaspyrides, C.D.; Voultzatis, Y.; Pavlidou, S.; Tsenoglou, C.; Dole, P.; Feigenbaum, A.; Paseiro, P.; Pastorelli, S.; Cruz Garcia, C. de la; Hankemeier, T.; Aucejo, S.

    2005-01-01

    A new experimental procedure for incorporation of model contaminants in polymers was developed as part of a general scheme for testing the efficiency of functional barriers in food packaging. The aim was to progressively pollute polymers in a controlled fashion up to a high level in the range of

  12. Evaluation of alternative surface runoff accounting procedures using the SWAT model

    Science.gov (United States)

    For surface runoff estimation in the Soil and Water Assessment Tool (SWAT) model, the curve number (CN) procedure is commonly adopted to calculate surface runoff by utilizing antecedent soil moisture condition (SCSI) in field. In the recent version of SWAT (SWAT2005), an alternative approach is ava...

  13. Equivalence of two models in single-phase multicomponent flow simulations

    KAUST Repository

    Wu, Yuanqing

    2016-02-28

    In this work, two models to simulate the single-phase multicomponent flow in reservoirs are introduced: single-phase multicomponent flow model and two-phase compositional flow model. Because the single-phase multicomponent flow is a special case of the two-phase compositional flow, the two-phase compositional flow model can also simulate the case. We compare and analyze the two models when simulating the single-phase multicomponent flow, and then demonstrate the equivalence of the two models mathematically. An experiment is also carried out to verify the equivalence of the two models.

  14. Test Standard Revision Update: JESD57, "Procedures for the Measurement of Single-Event Effects in Semiconductor Devices from Heavy-Ion Irradiation"

    Science.gov (United States)

    Lauenstein, Jean-Marie

    2015-01-01

    The JEDEC JESD57 test standard, Procedures for the Measurement of Single-Event Effects in Semiconductor Devices from Heavy-Ion Irradiation, is undergoing its first revision since 1996. In this talk, we place this test standard into context with other relevant radiation test standards to show its importance for single-event effect radiation testing for space applications. We show the range of industry, government, and end-user party involvement in the revision. Finally, we highlight some of the key changes being made and discuss the trade-space in which setting standards must be made to be both useful and broadly adopted.

  15. A P-value model for theoretical power analysis and its applications in multiple testing procedures

    Directory of Open Access Journals (Sweden)

    Fengqing Zhang

    2016-10-01

    Full Text Available Abstract Background Power analysis is a critical aspect of the design of experiments to detect an effect of a given size. When multiple hypotheses are tested simultaneously, multiplicity adjustments to p-values should be taken into account in power analysis. There are a limited number of studies on power analysis in multiple testing procedures. For some methods, the theoretical analysis is difficult and extensive numerical simulations are often needed, while other methods oversimplify the information under the alternative hypothesis. To this end, this paper aims to develop a new statistical model for power analysis in multiple testing procedures. Methods We propose a step-function-based p-value model under the alternative hypothesis, which is simple enough to perform power analysis without simulations, but not too simple to lose the information from the alternative hypothesis. The first step is to transform distributions of different test statistics (e.g., t, chi-square or F to distributions of corresponding p-values. We then use a step function to approximate each of the p-value’s distributions by matching the mean and variance. Lastly, the step-function-based p-value model can be used for theoretical power analysis. Results The proposed model is applied to problems in multiple testing procedures. We first show how the most powerful critical constants can be chosen using the step-function-based p-value model. Our model is then applied to the field of multiple testing procedures to explain the assumption of monotonicity of the critical constants. Lastly, we apply our model to a behavioral weight loss and maintenance study to select the optimal critical constants. Conclusions The proposed model is easy to implement and preserves the information from the alternative hypothesis.

  16. Single bumps in a 2-population homogenized neuronal network model

    Science.gov (United States)

    Kolodina, Karina; Oleynik, Anna; Wyller, John

    2018-05-01

    We investigate existence and stability of single bumps in a homogenized 2-population neural field model, when the firing rate functions are given by the Heaviside function. The model is derived by means of the two-scale convergence technique of Nguetseng in the case of periodic microvariation in the connectivity functions. The connectivity functions are periodically modulated in both the synaptic footprint and in the spatial scale. The bump solutions are constructed by using a pinning function technique for the case where the solutions are independent of the local variable. In the weakly modulated case the generic picture consists of two bumps (one narrow and one broad bump) for each admissible set of threshold values for firing. In addition, a new threshold value regime for existence of bumps is detected. Beyond the weakly modulated regime the number of bumps depends sensitively on the degree of heterogeneity. For the latter case we present a configuration consisting of three coexisting bumps. The linear stability of the bumps is studied by means of the spectral properties of a Fredholm integral operator, block diagonalization of this operator and the Fourier decomposition method. In the weakly modulated regime, one of the bumps is unstable for all relative inhibition times, while the other one is stable for small and moderate values of this parameter. The latter bump becomes unstable as the relative inhibition time exceeds a certain threshold. In the case of the three coexisting bumps detected in the regime of finite degree of heterogeneity, we have at least one stable bump (and maximum two stable bumps) for small and moderate values of the relative inhibition time.

  17. A discrete dislocation dynamics model of creeping single crystals

    Science.gov (United States)

    Rajaguru, M.; Keralavarma, S. M.

    2018-04-01

    Failure by creep is a design limiting issue for metallic materials used in several high temperature applications. Current theoretical models of creep are phenomenological with little connection to the underlying microscopic mechanisms. In this paper, a bottom-up simulation framework based on the discrete dislocation dynamics method is presented for dislocation creep aided by the diffusion of vacancies, known to be the rate controlling mechanism at high temperature and stress levels. The time evolution of the creep strain and the dislocation microstructure in a periodic unit cell of a nominally infinite single crystal is simulated using the kinetic Monte Carlo method, together with approximate constitutive laws formulated for the rates of thermal activation of dislocations over local pinning obstacles. The deformation of the crystal due to dislocation glide between individual thermal activation events is simulated using a standard dislocation dynamics algorithm, extended to account for constant stress periodic boundary conditions. Steady state creep conditions are obtained in the simulations with the predicted creep rates as a function of stress and temperature in good agreement with experimentally reported values. Arrhenius scaling of the creep rates as a function of temperature and power-law scaling with the applied stress are also reproduced, with the values of the power-law exponents in the high stress regime in good agreement with experiments.

  18. A Proposed Model for Selecting Measurement Procedures for the Assessment and Treatment of Problem Behavior.

    Science.gov (United States)

    LeBlanc, Linda A; Raetz, Paige B; Sellers, Tyra P; Carr, James E

    2016-03-01

    Practicing behavior analysts frequently assess and treat problem behavior as part of their ongoing job responsibilities. Effective measurement of problem behavior is critical to success in these activities because some measures of problem behavior provide more accurate and complete information about the behavior than others. However, not every measurement procedure is appropriate for every problem behavior and therapeutic circumstance. We summarize the most commonly used measurement procedures, describe the contexts for which they are most appropriate, and propose a clinical decision-making model for selecting measurement produces given certain features of the behavior and constraints of the therapeutic environment.

  19. Calibration procedure for a potato crop growth model using information from across Europe

    DEFF Research Database (Denmark)

    Heidmann, Tove; Tofteng, Charlotte; Abrahamsen, Per

    2008-01-01

    In the FertOrgaNic EU project, 3 years of field experiments with drip irrigation and fertigation were carried out at six different sites across Europe, involving seven different varieties of potato. The Daisy model, which simulates plant growth together with water and nitrogen dynamics, was used...... to simulate the field experiments. An initial potato parameterisation was generated from an independent dataset and was used for site-specific calibrations. At those sites where the same variety was used for all 3 years, the calibration of the initial potato model was based on the first 2 years using the last...... for adaptation of the Daisy model to new potato varieties or for the improvement of the existing parameter set. The procedure is then, as a starting point, to focus the calibration process on the recommended list of parameters to change. We demonstrate this approach by showing the procedure for recalibrating...

  20. Longitudinal data analyses using linear mixed models in SPSS: concepts, procedures and illustrations.

    Science.gov (United States)

    Shek, Daniel T L; Ma, Cecilia M S

    2011-01-05

    Although different methods are available for the analyses of longitudinal data, analyses based on generalized linear models (GLM) are criticized as violating the assumption of independence of observations. Alternatively, linear mixed models (LMM) are commonly used to understand changes in human behavior over time. In this paper, the basic concepts surrounding LMM (or hierarchical linear models) are outlined. Although SPSS is a statistical analyses package commonly used by researchers, documentation on LMM procedures in SPSS is not thorough or user friendly. With reference to this limitation, the related procedures for performing analyses based on LMM in SPSS are described. To demonstrate the application of LMM analyses in SPSS, findings based on six waves of data collected in the Project P.A.T.H.S. (Positive Adolescent Training through Holistic Social Programmes) in Hong Kong are presented.

  1. Visual perception of procedural textures: identifying perceptual dimensions and predicting generation models.

    Directory of Open Access Journals (Sweden)

    Jun Liu

    Full Text Available Procedural models are widely used in computer graphics for generating realistic, natural-looking textures. However, these mathematical models are not perceptually meaningful, whereas the users, such as artists and designers, would prefer to make descriptions using intuitive and perceptual characteristics like "repetitive," "directional," "structured," and so on. To make up for this gap, we investigated the perceptual dimensions of textures generated by a collection of procedural models. Two psychophysical experiments were conducted: free-grouping and rating. We applied Hierarchical Cluster Analysis (HCA and Singular Value Decomposition (SVD to discover the perceptual features used by the observers in grouping similar textures. The results suggested that existing dimensions in literature cannot accommodate random textures. We therefore utilized isometric feature mapping (Isomap to establish a three-dimensional perceptual texture space which better explains the features used by humans in texture similarity judgment. Finally, we proposed computational models to map perceptual features to the perceptual texture space, which can suggest a procedural model to produce textures according to user-defined perceptual scales.

  2. Modeling environmental contamination in hospital single- and four-bed rooms.

    Science.gov (United States)

    King, M-F; Noakes, C J; Sleigh, P A

    2015-12-01

    Aerial dispersion of pathogens is recognized as a potential transmission route for hospital acquired infections; however, little is known about the link between healthcare worker (HCW) contacts' with contaminated surfaces, the transmission of infections and hospital room design. We combine computational fluid dynamics (CFD) simulations of bioaerosol deposition with a validated probabilistic HCW-surface contact model to estimate the relative quantity of pathogens accrued on hands during six types of care procedures in two room types. Results demonstrate that care type is most influential (P model predicting the surface contacts by HCW and the subsequent accretion of pathogenic material as they perform standard patient care. This model indicates that single rooms may significantly reduce the risk of cross-contamination due to indirect infection transmission. Not all care types pose the same risks to patients, and housekeeping performed by HCWs may be an important contribution in the transmission of pathogens between patients. Ventilation rates and positioning of infectious patients within four-bed rooms can mitigate the accretion of pathogens, whereby reducing the risk of missed hand hygiene opportunities. The model provides a tool to quantitatively evaluate the influence of hospital room design on infection risk. © 2015 The Authors. Indoor Air Published by John Wiley & Sons Ltd.

  3. CANFIS: A non-linear regression procedure to produce statistical air-quality forecast models

    Energy Technology Data Exchange (ETDEWEB)

    Burrows, W.R.; Montpetit, J. [Environment Canada, Downsview, Ontario (Canada). Meteorological Research Branch; Pudykiewicz, J. [Environment Canada, Dorval, Quebec (Canada)

    1997-12-31

    Statistical models for forecasts of environmental variables can provide a good trade-off between significance and precision in return for substantial saving of computer execution time. Recent non-linear regression techniques give significantly increased accuracy compared to traditional linear regression methods. Two are Classification and Regression Trees (CART) and the Neuro-Fuzzy Inference System (NFIS). Both can model predict and distributions, including the tails, with much better accuracy than linear regression. Given a learning data set of matched predict and predictors, CART regression produces a non-linear, tree-based, piecewise-continuous model of the predict and data. Its variance-minimizing procedure optimizes the task of predictor selection, often greatly reducing initial data dimensionality. NFIS reduces dimensionality by a procedure known as subtractive clustering but it does not of itself eliminate predictors. Over-lapping coverage in predictor space is enhanced by NFIS with a Gaussian membership function for each cluster component. Coefficients for a continuous response model based on the fuzzified cluster centers are obtained by a least-squares estimation procedure. CANFIS is a two-stage data-modeling technique that combines the strength of CART to optimize the process of selecting predictors from a large pool of potential predictors with the modeling strength of NFIS. A CANFIS model requires negligible computer time to run. CANFIS models for ground-level O{sub 3}, particulates, and other pollutants will be produced for each of about 100 Canadian sites. The air-quality models will run twice daily using a small number of predictors isolated from a large pool of upstream and local Lagrangian potential predictors.

  4. Flagellates as model system for gravity detection of single cells

    Science.gov (United States)

    Lebert, Michael; Richter, Peter; Daiker, Viktor; Schuster, Martin; Tebart, Jenny; Strauch, Sebastian M.; Donat-Peter, H.

    Euglena gracilis is a unicellular, photosynthetic organism which uses light and gravity as en-vironmental hints to reach and stay in horizons of the water column which are optimal for growth and reproduction. The orientation in respect to light (so called positive and nega-tive phototaxis, i.e. movement toward or away of a light source) was well known and fairly good understood. In contrast, knowledge about the movement away from the centre of gravity (negative gravitaxis) was rather scarce. Over a century it was unclear whether orientation in respect to the gravity vector is based on a physical or a physiological mechanism. Recent results clearly favour the latter. Knock-down mutants (RNAi) were characterized which define certain key components of the gravitactic signal transduction chain. These key components include a TRP-like channel, a gravitaxis-specific calmodulin and a protein kinase A. The molecular characterization of these components is currently performed and will be presented. Euglena is not only a model system for the close understanding of gravity detection in single cells, but can also be used as photosynthetic component, i.e. oxygen source and carbon dioxide as well as nitrogenic components sink in Closed Environmental Systems (CES). Due CES are systems of choice in times of scarce flight opportunities. They allow a massive sample sharing and combine possibilities to do microgravity research for biologists but also for engineers, physicists and material scientists. Recent attempts include Aquacells and Omegahab. In the near future miniaturized systems (Chinese ShenZhou) as well as advanced CES will be flown or tested, respectively. Current attempts and plans will be presented.

  5. A Two-Dimensional Modeling Procedure to Estimate the Loss Equivalent Resistance Including the Saturation Effect

    Directory of Open Access Journals (Sweden)

    Rosa Ana Salas

    2013-11-01

    Full Text Available We propose a modeling procedure specifically designed for a ferrite inductor excited by a waveform in time domain. We estimate the loss resistance in the core (parameter of the electrical model of the inductor by means of a Finite Element Method in 2D which leads to significant computational advantages over the 3D model. The methodology is validated for an RM (rectangular modulus ferrite core working in the linear and the saturation regions. Excellent agreement is found between the experimental data and the computational results.

  6. Analyses of the energy-dependent single separable potential models for the NN scattering

    International Nuclear Information System (INIS)

    Ahmad, S.S.; Beghi, L.

    1981-08-01

    Starting from a systematic study of the salient features regarding the quantum-mechanical two-particle scattering off an energy-dependent (ED) single separable potential and its connection with the rank-2 energy-independent (EI) separable potential in the T-(K-) amplitude formulation, the present status of the ED single separable potential models due to Tabakin (M1), Garcilazo (M2) and Ahmad (M3) has been discussed. It turned out that the incorporation of a self-consistent optimization procedure improves considerably the results of the 1 S 0 and 3 S 1 scattering phase shifts for the models (M2) and (M3) up to the CM wave number q=2.5 fm -1 , although the extrapolation of the results up to q=10 fm -1 reveals that the two models follow the typical behaviour of the well-known super-soft core potentials. It has been found that a variant of (M3) - i.e. (M4) involving one more parameter - gives the phase shifts results which are generally in excellent agreement with the data up to q=2.5 fm -1 and the extrapolation of the results for the 1 S 0 case in the higher wave number range not only follows the corresponding data qualitatively but also reflects a behaviour similar to the Reid soft core and Hamada-Johnston potentials together with a good agreement with the recent [4/3] Pade fits. A brief discussion regarding the features resulting from the variations in the ED parts of all the four models under consideration and their correlations with the inverse scattering theory methodology concludes the paper. (author)

  7. Semantic Modeling of Administrative Procedures from a Spanish Regional Public Administration

    Directory of Open Access Journals (Sweden)

    Francisco José Hidalgo López

    2018-02-01

    Full Text Available Over the past few years, Public Administrations have been providing systems for procedures and files electronic processing to ensure compliance with regulations and provide public services to citizens. Although each administration provides similar services to their citizens, these systems usually differ from the internal information management point of view since they usually come from different products and manufacturers. The common framework that regulations demand, and that Public Administrations must respect when processing electronic files, provides a unique opportunity for the development of intelligent agents in the field of administrative processes. However, for this development to be truly effective and applicable to the public sector, it is necessary to have a common representation model for these administrative processes. Although a lot of work has already been done in the development of public information reuse initiatives and common vocabularies standardization, this has not been carried out at the processes level. In this paper, we propose a semantic representation model of both processes models and processes for Public Administrations: the procedures and administrative files. The goal is to improve public administration open data initiatives and help to develop their sustainability policies, such as improving decision-making procedures and administrative management sustainability. As a case study, we modelled public administrative processes and files in collaboration with a Regional Public Administration in Spain, the Principality of Asturias, which enabled access to its information systems, helping the evaluation of our approach.

  8. OPE3 : A model system for single-molecule transport

    NARCIS (Netherlands)

    Frisenda, R.

    2016-01-01

    In this dissertation, charge-transport through individual organic molecules is investigated. The single molecules are contacted with two-terminal mechanically controllable break junction gold electrodes and their electrical and mechanical behavior studied at room and low temperature.

  9. Modeling and Development of Superconducting Nanowire Single Photon Detectors

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal outlines a research project as the central component of a Ph.D. program focused on the device physics of superconducting nanowire single photon...

  10. Percutaneous Treatment of Simple Hepatic Cysts: The Long-Term Results of PAIR and Catheterization Techniques as Single-Session Procedures

    Energy Technology Data Exchange (ETDEWEB)

    Akhan, Okan, E-mail: akhano@tr.net [Hacettepe University Faculty of Medicine, Department of Radiology (Turkey); Islim, Filiz, E-mail: fislim@yahoo.com [Istanbul Bakirkoy Dr. Sadi Konuk Training and Research Hospital, Department of Radiology (Turkey); Balci, Sinan, E-mail: snnbalci@gmail.com [Hacettepe University Faculty of Medicine, Department of Radiology (Turkey); Erbahceci, Aysun, E-mail: aysunerbahceci@yahoo.com [Istanbul Bakirkoy Dr. Sadi Konuk Training and Research Hospital, Department of Radiology (Turkey); Akpınar, Burcu, E-mail: burcu-akpinar@yahoo.com; Ciftci, Turkmen, E-mail: turkmenciftci@yahoo.com; Akinci, Devrim, E-mail: akincid@hotmail.com [Hacettepe University Faculty of Medicine, Department of Radiology (Turkey)

    2016-06-15

    PurposeThe purpose of our study is to evaluate results of percutaneous aspiration with alcohol sclerotherapy in symptomatic patients with simple hepatic cysts by employing single-session techniques either by a needle or a catheter.Materials and MethodsWe retrospectively included 39 simple hepatic cysts in 35 patients treated via percutaneous aspiration and single-session alcohol sclerotherapy between years 1993 and 2012. Indications were pain (n = 28) or ruling out cystic echinococcus (CE) disease (n = 7). 29 cysts in 26 patients were treated by needle technique (Group A) and ten cysts in nine patients were treated by single-session catheter technique (Group B). Patients were followed for 4–173 months (median: 38 months).ResultsAll patients were successfully treated. Before procedure, cyst volumes were 21–676 cc (median: 94 cc). Post-procedure cyst volumes at last follow-up were 0-40 cc (median: 1 cc). The mean decrease in cyst volume was 95.92 ± 2.86 % in all patients (95.96 ± 3.26 % in Group A and 95.80 ± 6.20 % in Group B). There was no statistically significant difference between the volume reduction rates of Group A and Group B. Only one patient, in Group B, developed a major complication, an abscess. Hospitalization period was 1 day for all patients.ConclusionsFor patients with symptomatic simple hepatic cysts smaller than 500 cc in volume by using puncture, aspiration, injection, and reaspiration (PAIR) technique with only needle, single-session alcohol sclerotherapy of 10 min is a safe and effective procedure with high success rate.

  11. A Perspective On Procedural Modeling Based On Structural Analysis = Una perspectiva sobre modelado procedural basado en analisis estructurales

    OpenAIRE

    Fita, Josep Lluís; Besuievsky, Gonzalo; Patow, Gustavo

    2017-01-01

    Con el creciente aumento de las capacidades computacionales, el análisis estructural se ha convertido en una herramienta clave para la evaluación del estudio y conservación de edificios antiguos por parte de los historiadores del arte, curadores y otros especialistas. Por otro lado, el floreciente campo del modelado procedural ha proporcionado avances interesantes para la reconstrucción de edificios y estructuras urbanas no accesibles. Sin embargo, h...

  12. The BDS Triple Frequency Pseudo-range Correlated Stochastic Model of Single Station Modeling Method

    Directory of Open Access Journals (Sweden)

    HUANG Lingyong

    2017-05-01

    Full Text Available In order to provide a reliable pseudo-range stochastic model, a method is studied to estimate the BDS triple-frequency pseudo-range related stochastic model based on three BDS triple-frequency pseudo-range minus carrier (GIF combinations using the data of a single station. In this algorithm, the low order polynomial fitting method is used to fit the GIF combination in order to eliminate the error and other constants except non pseudo noise at first. And then, multiple linear regression analysis method is used to model the stochastic function of three linearly independent GIF combinations. Finally the related stochastic model of the original BDS triple-frequency pseudo-range observations is obtained by linear transformation. The BDS triple-frequency data verification results show that this algorithm can get a single station related stochastic model of BDS triple-frequency pseudo-range observation, and it is advantageous to provide accurate stochastic model for navigation and positioning and integrity monitoring.

  13. Procedures for the quantification of whole-tissue immunofluorescence images obtained at single-cell resolution during murine tubular organ development.

    Directory of Open Access Journals (Sweden)

    Tsuyoshi Hirashima

    Full Text Available Whole-tissue quantification at single-cell resolution has become an inevitable approach for further quantitative understanding of morphogenesis in organ development. The feasibility of the approach has been dramatically increased by recent technological improvements in optical tissue clearing and microscopy. However, the series of procedures required for this approach to lead to successful whole-tissue quantification is far from developed. To provide the appropriate procedure, we here show tips for each critical step of the entire process, including fixation for immunofluorescence, optical clearing, and digital image processing, using developing murine internal organs such as epididymis, kidney, and lung as an example. Through comparison of fixative solutions and of clearing methods, we found optimal conditions to achieve clearer deep-tissue imaging of specific immunolabeled targets and explain what methods result in vivid volume imaging. In addition, we demonstrated that three-dimensional digital image processing after optical clearing produces objective quantitative data for the whole-tissue analysis, focusing on the spatial distribution of mitotic cells in the epididymal tubule. The procedure for the whole-tissue quantification shown in this article should contribute to systematic measurements of cellular processes in developing organs, accelerating the further understanding of morphogenesis at the single cell level.

  14. Prediction of Placental Barrier Permeability: A Model Based on Partial Least Squares Variable Selection Procedure

    Directory of Open Access Journals (Sweden)

    Yong-Hong Zhang

    2015-05-01

    Full Text Available Assessing the human placental barrier permeability of drugs is very important to guarantee drug safety during pregnancy. Quantitative structure–activity relationship (QSAR method was used as an effective assessing tool for the placental transfer study of drugs, while in vitro human placental perfusion is the most widely used method. In this study, the partial least squares (PLS variable selection and modeling procedure was used to pick out optimal descriptors from a pool of 620 descriptors of 65 compounds and to simultaneously develop a QSAR model between the descriptors and the placental barrier permeability expressed by the clearance indices (CI. The model was subjected to internal validation by cross-validation and y-randomization and to external validation by predicting CI values of 19 compounds. It was shown that the model developed is robust and has a good predictive potential (r2 = 0.9064, RMSE = 0.09, q2 = 0.7323, rp2 = 0.7656, RMSP = 0.14. The mechanistic interpretation of the final model was given by the high variable importance in projection values of descriptors. Using PLS procedure, we can rapidly and effectively select optimal descriptors and thus construct a model with good stability and predictability. This analysis can provide an effective tool for the high-throughput screening of the placental barrier permeability of drugs.

  15. A Numerical Procedure for Model Identifiability Analysis Applied to Enzyme Kinetics

    DEFF Research Database (Denmark)

    Daele, Timothy, Van; Van Hoey, Stijn; Gernaey, Krist

    2015-01-01

    The proper calibration of models describing enzyme kinetics can be quite challenging. In the literature, different procedures are available to calibrate these enzymatic models in an efficient way. However, in most cases the model structure is already decided on prior to the actual calibration...... and Pronzato (1997) and which can be easily set up for any type of model. In this paper the proposed approach is applied to the forward reaction rate of the enzyme kinetics proposed by Shin and Kim(1998). Structural identifiability analysis showed that no local structural model problems were occurring......) identifiability problems. By using the presented approach it is possible to detect potential identifiability problems and avoid pointless calibration (and experimental!) effort....

  16. Use of a Single CPT Code for Risk Adjustment in American College of Surgeons NSQIP Database: Is There Potential Bias with Practice-Pattern Differences in Multiple Procedures under the Same Anesthetic?

    Science.gov (United States)

    Cohen, Mark E; Liu, Yaoming; Liu, Jason B; Ko, Clifford Y; Hall, Bruce L

    2018-03-01

    American College of Surgeons NSQIP risk-adjustment models rely on the designated "principal" CPT code to account for procedure-related risk. However, if hospitals differ in their propensity to undertake multiple major operations under the same anesthetic, then risk adjustment using only a single code could bias hospital quality estimates. This study investigated this possibility for bias. We examined hospital odds ratios (ORs) when either the principal CPT code was used for risk adjustment (along with other standard NSQIP predictor variables) or when this code was used in addition to the remaining reported CPT code with the highest associated risk. We examined models for general surgery mortality and morbidity and morbidity in datasets that included mastectomy and/or breast reconstruction, or hysterectomy and/or gynecologic reconstruction as areas known to likely involve more than 1 procedure. Hospital ORs based on 1 vs 2 CPT codes for risk adjustment were essentially the same for mortality and morbidity general surgery models and for the mastectomy and/or breast reconstruction model. For hysterectomy and/or gynecologic reconstruction, the 1 CPT code model tended to slightly overestimate ORs compared with the 2 CPT codes model, when the hospital's OR and the proportion of combined operations were large. Conditions under which practice-pattern-associated modeling bias might exist appear to be uncommon and to have a small impact on quality assessments for the areas examined. The evidence suggests that, within the American College of Surgeons NSQIP modeling paradigm, the principal CPT code adequately risk adjusts for operative procedure in performance assessments. Copyright © 2018 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

  17. Congenital Deficiency of Distal Ulna and Dislocation of the Radial Head Treated by Single Bone Forearm Procedure

    Directory of Open Access Journals (Sweden)

    Paragjyoti Gogoi

    2014-01-01

    Full Text Available Congenital deficiency of part of distal ulna affecting the distal radio-ulnar joint is a rare disorder. It is even rarer to find the association of proximal radio-ulnar joint dislocation along with distal ulnar deficiency. This type of congenital forearm anomaly is difficult to treat. Conversion to a single bone forearm in the expense of pronation-supination movement is a viable option. By doing so the elbow and wrist can be stabilized; however movement is possible in only one plane. We are describing here a girl of 8 years having proximal radio-ulnar joint dislocation along with deficiency of distal ulna treated by converting into a single bone forearm.

  18. Implications of the Declarative/Procedural Model for Improving Second Language Learning: The Role of Memory Enhancement Techniques

    Science.gov (United States)

    Ullman, Michael T.; Lovelett, Jarrett T.

    2018-01-01

    The declarative/procedural (DP) model posits that the learning, storage, and use of language critically depend on two learning and memory systems in the brain: declarative memory and procedural memory. Thus, on the basis of independent research on the memory systems, the model can generate specific and often novel predictions for language. Till…

  19. Corneal flap thickness with the Moria M2 single-use head 90 microkeratome in 72 consecutive LASIK procedures

    OpenAIRE

    Karabela,Yunus; Muftuoglu,Orkun; Kaya,Faruk

    2017-01-01

    Yunus Karabela,1 Orkun Muftuoglu,2 Faruk Kaya1 1Department of Ophthalmology, Medipol University, 2Department of Ophthalmology, Vehbi Koç Vakfi Amerikan Hospital, Istanbul, Turkey Purpose: This study aimed to evaluate the accuracy and consistency of corneal flap thickness in laser-assisted in situ keratomileusis (LASIK) with the Moria M2 single-use head 90 microkeratome. Methods: The central corneal thickness of 72 (37 right, 35 left) eyes of 37 patients was measured by ultrasonic...

  20. Review and meta-analysis of prospective randomized controlled trials (RCTs) comparing laparo-endoscopic single site and multiport laparoscopy in gynecologic operative procedures.

    Science.gov (United States)

    Pontis, Alessandro; Sedda, Federica; Mereu, Liliana; Podda, Mauro; Melis, Gian Benedetto; Pisanu, Adolfo; Angioni, Stefano

    2016-09-01

    To critically appraise published randomized controlled trials (RCTs) comparing laparo-endoscopic single site (LESS) and multi-port laparoscopic (MPL) in gynecologic operative surgery; the aim was to assess feasibility, safety, and potential benefits of LESS in comparison to MPL. A systematic review and meta-analysis of eleven RCTs. Women undergoing operative LESS and MPL gynecologic procedure (hysterectomy, cystectomy, salpingectomy, salpingo-oophorectomy, myomectomy). Outcomes evaluated were as follows: postoperative overall morbidity, postoperative pain evaluation at 6, 12, 24 and 48 h, cosmetic patient satisfaction, conversion rate, body mass index (BMI), operative time, blood loss, hemoglobin drop, postoperative hospital stay. Eleven RCTs comprising 956 women with gynecologic surgical disease randomized to either LESS (477) or MPL procedures (479) were analyzed systematically. The LESS approach is a surgical procedure with longer operative and better cosmetic results time than MPL but without statistical significance. Operative outcomes, postoperative recovery, postoperative morbidity and patient satisfaction are similar in LESS and MPL. LESS may be considered an alternative to MPL with comparable feasibility and safety in gynecologic operative procedures. However, it does not offer the expected advantages in terms of postoperative pain and cosmetic satisfaction.

  1. Socket seal surgery: Clinical uses in implant dentistry and guided bone regeneration procedures for single tooth replacement in the esthetic zone.

    Science.gov (United States)

    Negri, Bruno; Zuhr, Otto; Fickl, Stefan; Ciurana, Xavier Rodríguez; Navarro Martínez, José Manuel; Blanco, Víctor Méndez

    2016-02-01

    Restoring failing anterior teeth with a dental implant is considered a complex treatment even with thorough biologic knowledge of the situation. The goal is to produce a result in which the labial soft tissues and the papillae remain stable over time. Treatment of the fresh extraction socket in the alveolar ridge presents a challenge in everyday clinical practice. Regardless of the subsequent treatment, maintenance of the ridge contour will frequently facilitate all further therapeutic steps. Socket seal surgery and socket preservation in combination with immediate, early, or delayed implant placement can be valuable procedures for single tooth replacement. However, their potential as ridge preservation techniques in these different situations still needs to be demonstrated. The use of these procedures is illustrated in three consecutive cases.

  2. Collaborative CAD Synchronization Based on a Symmetric and Consistent Modeling Procedure

    Directory of Open Access Journals (Sweden)

    Yiqi Wu

    2017-04-01

    Full Text Available One basic issue with collaborative computer aided design (Co-CAD is how to maintain valid and consistent modeling results across all design sites. Moreover, modeling history is important in parametric CAD modeling. Therefore, different from a typical co-editing approach, this paper proposes a novel method for Co-CAD synchronization, in which all Co-CAD sites maintain symmetric and consistent operating procedures. Consequently, the consistency of both modeling results and history can be achieved. In order to generate a valid, unique, and symmetric queue among collaborative sites, a set of correlated mechanisms is presented in this paper. Firstly, the causal relationship of operations is maintained. Secondly, the operation queue is reconstructed for partial concurrency operation, and the concurrent operation can be retrieved. Thirdly, a symmetric, concurrent operation control strategy is proposed to determine the order of operations and resolve possible conflicts. Compared with existing Co-CAD consistency methods, the proposed method is convenient and flexible in supporting collaborative design. The experiment performed based on the collaborative modeling procedure demonstrates the correctness and applicability of this work.

  3. Single item inventory models : A time- and event- averages approach

    NARCIS (Netherlands)

    E.M. Bazsa-Oldenkamp; P. den Iseger

    2003-01-01

    textabstractThis paper extends a fundamental result about single-item inventory systems. This approach allows more general performance measures, demand processes and order policies, and leads to easier analysis and implementation, than prior research. We obtain closed form expressions for the

  4. Ex-vivo training model for laparoendoscopic single-site surgery

    Directory of Open Access Journals (Sweden)

    Kommu Sashi

    2011-01-01

    Full Text Available Background: Laparoendoscopic single-site surgery (LESS has recently been applied successfully in the performance of a host of surgical procedures. Preliminary consensus from the experts is that this mode of surgery is technically challenging and requires expertise. The transition from trainee to practicing surgeon, especially in complex procedures with challenging learning curves, takes time and mentor-guided nurturing. However, the trainee needs to use platforms of training to gain the skills that are deemed necessary for undertaking the live human case. Objective: This article aims to demonstrate a step-by-step means of how to acquire the necessary instrumentation and build a training model for practicing steeplechase exercises in LESS for urological surgeons and trainees. The tool built as a result of this could set the platform for performance of basic and advanced skills uptake using conventional, bent and articulated instruments. A preliminary construct validity of the platform was conducted. Materials and Methods: A box model was fitted with an R-Port™ and camera. Articulated and conventional instruments were used to demonstrate basic exercises (e.g. glove pattern cutting, loop stacking and suturing and advanced exercises (e.g. pyeloplasty. The validation included medical students (M, final year laparoscopic fellows (F and experienced consultant laparoscopic surgeons (C with at least 50 LESS cases experience in total, were tested on eight basic skill tasks (S including manipulation of the flexible cystoscope (S1, hand eye coordination (S2, cutting with flexible scissors (S3, grasping with flexible needle holders (S4, two-handed maneuvers (S5, object translocation (S6, cross hand suturing with flexible instruments (S7 and conduction of an ex-vivo pyeloplasty. Results: The successful application of the box model was demonstrated by trainee based exercises. The cost of the kit with circulated materials was less than £150 (Pounds Sterling

  5. A systematic procedure for the incorporation of common cause events into risk and reliability models

    International Nuclear Information System (INIS)

    Fleming, K.N.; Mosleh, A.; Deremer, R.K.

    1986-01-01

    Common cause events are an important class of dependent events with respect to their contribution to system unavailability and to plant risk. Unfortunately, these events have not been treated with any king of consistency in applied risk studies over the past decade. Many probabilistic risk assessments (PRA) have not included these events at all, and those that have did not employ the kind of systematic procedures that are needed to achieve consistency, accuracy, and credibility in this area of PRA methodology. In this paper, the authors report on the progress recently made in the development of a systematic approach for incorporating common cause events into applied risk and reliability evaluations. This approach takes advantage of experience from recently completed PRAs and is the result of a project, sponsored by the Electric Power Research Institute (EPRI), in which procedures for dependent events analysis are being developed. Described in this paper is a general framework for system-level common cause failure (CCF) analysis and its application to a three-train auxiliary feedwater system. Within this general framework, three parametric CCF models are compared, including the basic parameter (BP), multiple Greek letter (MGL), and binominal failure rate (BFR) models. Pitfalls of not following the recommended procedure are discussed, and some old issues, such as the benefits of redundancy and diversity, are reexamined. (orig.)

  6. A rapid automated procedure for laboratory and shipboard spectrophotometric measurements of seawater alkalinity: continuously monitored single-step acid additions

    Science.gov (United States)

    Liu, X.; Byrne, R. H.; Lindemuth, M.; Easley, R. A.; Patsavas, M. C.

    2012-12-01

    An automated system for shipboard and laboratory alkalinity measurements is presented. The simple system, which consists of a Dosimat titrator to deliver acid volumetrically and a USB 4000 spectrophotometer to monitor the titration progress, provides fast, precise and accurate measurements of total alkalinity for oceanographic research. The analytical method is based on single-point HCl titrations of seawater samples of a known volume; bromol cresol purple is used as an indicator to determine the final pH. Field data from an Arctic cruise demonstrates accuracy and precision around 1 micro mol/kg and a sample processing rate of 6 min per sample.

  7. A model treatment refusal procedure for defendants found incompetent to stand trial in the ninth circuit.

    Science.gov (United States)

    Epson, Martin; Rodol, Liban; Bloom, Joseph D

    2012-01-01

    Pretrial detainees have a constitutionally protected right to refuse medical treatment in most circumstances; however, individuals found incompetent to stand trial (IST) due to a mental disorder can be treated involuntarily by clinicians who adhere to careful medical and legal procedures. The process of involuntary treatment of IST pretrial detainees begins with categorization into particular legal and medical groups. These different categories affect the individual's access to treatment. In this article, we review the relevant case law for the jurisdiction of the Ninth Circuit and place the medical-legal debate regarding these procedures in the context of recent cases. To address the medical-legal disjunction, we propose and discuss a model for managing treatment refusal in pretrial detainees found IST.

  8. Calculation of single chain cellulose elasticity using fully atomistic modeling

    Science.gov (United States)

    Xiawa Wu; Robert J. Moon; Ashlie Martini

    2011-01-01

    Cellulose nanocrystals, a potential base material for green nanocomposites, are ordered bundles of cellulose chains. The properties of these chains have been studied for many years using atomic-scale modeling. However, model predictions are difficult to interpret because of the significant dependence of predicted properties on model details. The goal of this study is...

  9. Logistic regression modelling: procedures and pitfalls in developing and interpreting prediction models

    Directory of Open Access Journals (Sweden)

    Nataša Šarlija

    2017-01-01

    Full Text Available This study sheds light on the most common issues related to applying logistic regression in prediction models for company growth. The purpose of the paper is 1 to provide a detailed demonstration of the steps in developing a growth prediction model based on logistic regression analysis, 2 to discuss common pitfalls and methodological errors in developing a model, and 3 to provide solutions and possible ways of overcoming these issues. Special attention is devoted to the question of satisfying logistic regression assumptions, selecting and defining dependent and independent variables, using classification tables and ROC curves, for reporting model strength, interpreting odds ratios as effect measures and evaluating performance of the prediction model. Development of a logistic regression model in this paper focuses on a prediction model of company growth. The analysis is based on predominantly financial data from a sample of 1471 small and medium-sized Croatian companies active between 2009 and 2014. The financial data is presented in the form of financial ratios divided into nine main groups depicting following areas of business: liquidity, leverage, activity, profitability, research and development, investing and export. The growth prediction model indicates aspects of a business critical for achieving high growth. In that respect, the contribution of this paper is twofold. First, methodological, in terms of pointing out pitfalls and potential solutions in logistic regression modelling, and secondly, theoretical, in terms of identifying factors responsible for high growth of small and medium-sized companies.

  10. The use of flow models for design of plant operating procedures

    International Nuclear Information System (INIS)

    Lind, M.

    1982-03-01

    The report describe a systematic approach to the design of operating procedures or sequence automatics for process plant control. It is shown how flow models representing the topology of mass and energy flows on different levels of function provide plant information which is important for the considered design problem. The modelling methodology leads to the definition of three categories of control tasks. Two tasks relate to the regulation and control of changes of levels and flows of mass and energy in a system within a defined mode of operation. The third type relate to the control actions necessary for switching operations involved in changes of operating mode. These control tasks are identified for a given plant as part of the flow modelling activity. It is discussed how the flow model deal with the problem of assigning control task precedence in time eg. during start-up or shut-down operations. The method may be a basis for providing automated procedure support to the operator in unforeseen situations or may be a tool for control design. (auth.)

  11. On modeling of geometrically necessary dislocation densities in plastically deformed single crystals

    DEFF Research Database (Denmark)

    Niordson, Christian Frithiof; Kysar, Jeffrey W.

    2013-01-01

    A computational method for strain gradient single crystal plasticity is presented. The method accounts for both recoverable and dissipative gradient effects. The mathematical solution procedure is predicated on two minimum principles along the lines of those devised by Fleck and Willis (2009) for...

  12. The ARM-GCSS Intercomparison Study of Single-Column Models and Cloud System Models

    International Nuclear Information System (INIS)

    Cederwall, R.T.; Rodriques, D.J.; Krueger, S.K.; Randall, D.A.

    1999-01-01

    The Single-Column Model (SCM) Working Group (WC) and the Cloud Working Group (CWG) in the Atmospheric Radiation Measurement (ARM) Program have begun a collaboration with the GEWEX Cloud System Study (GCSS) WGs. The forcing data sets derived from the special ARM radiosonde measurements made during the SCM Intensive Observation Periods (IOPs), the wealth of cloud and related data sets collected by the ARM Program, and the ARM infrastructure support of the SCM WG are of great value to GCSS. In return, GCSS brings the efforts of an international group of cloud system modelers to bear on ARM data sets and ARM-related scientific questions. The first major activity of the ARM-GCSS collaboration is a model intercomparison study involving SCMs and cloud system models (CSMs), also known as cloud-resolving or cloud-ensemble models. The SCM methodologies developed in the ARM Program have matured to the point where an intercomparison will help identify the strengths and weaknesses of various approaches. CSM simulations will bring much additional information about clouds to evaluate cloud parameterizations used in the SCMs. CSMs and SCMs have been compared successfully in previous GCSS intercomparison studies for tropical conditions. The ARM Southern Great Plains (SGP) site offers an opportunity for GCSS to test their models in continental, mid-latitude conditions. The Summer 1997 SCM IOP has been chosen since it provides a wide range of summertime weather events that will be a challenging test of these models

  13. A Comparison of Single Factor Markov-Functional and Multi Factor Market Models

    NARCIS (Netherlands)

    R. Pietersz (Raoul); A.A.J. Pelsser (Antoon)

    2005-01-01

    textabstractWe compare single factor Markov-functional and multi factor market models for hedging performance of Bermudan swaptions. We show that hedging performance of both models is comparable, thereby supporting the claim that Bermudan swaptions can be adequately riskmanaged with single factor

  14. A structurally based analytic model of growth and biomass dynamics in single species stands of conifers

    Science.gov (United States)

    Robin J. Tausch

    2015-01-01

    A theoretically based analytic model of plant growth in single species conifer communities based on the species fully occupying a site and fully using the site resources is introduced. Model derivations result in a single equation simultaneously describes changes over both, different site conditions (or resources available), and over time for each variable for each...

  15. 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.

  16. Nitrous oxide emissions from cropland: a procedure for calibrating the DayCent biogeochemical model using inverse modelling

    Science.gov (United States)

    Rafique, Rashad; Fienen, Michael N.; Parkin, Timothy B.; Anex, Robert P.

    2013-01-01

    DayCent is a biogeochemical model of intermediate complexity widely used to simulate greenhouse gases (GHG), soil organic carbon and nutrients in crop, grassland, forest and savannah ecosystems. Although this model has been applied to a wide range of ecosystems, it is still typically parameterized through a traditional “trial and error” approach and has not been calibrated using statistical inverse modelling (i.e. algorithmic parameter estimation). The aim of this study is to establish and demonstrate a procedure for calibration of DayCent to improve estimation of GHG emissions. We coupled DayCent with the parameter estimation (PEST) software for inverse modelling. The PEST software can be used for calibration through regularized inversion as well as model sensitivity and uncertainty analysis. The DayCent model was analysed and calibrated using N2O flux data collected over 2 years at the Iowa State University Agronomy and Agricultural Engineering Research Farms, Boone, IA. Crop year 2003 data were used for model calibration and 2004 data were used for validation. The optimization of DayCent model parameters using PEST significantly reduced model residuals relative to the default DayCent parameter values. Parameter estimation improved the model performance by reducing the sum of weighted squared residual difference between measured and modelled outputs by up to 67 %. For the calibration period, simulation with the default model parameter values underestimated mean daily N2O flux by 98 %. After parameter estimation, the model underestimated the mean daily fluxes by 35 %. During the validation period, the calibrated model reduced sum of weighted squared residuals by 20 % relative to the default simulation. Sensitivity analysis performed provides important insights into the model structure providing guidance for model improvement.

  17. Fast Detection of a BRCA2 Large Genomic Duplication by Next Generation Sequencing as a Single Procedure: A Case Report

    Directory of Open Access Journals (Sweden)

    Marcella Nunziato

    2017-11-01

    Full Text Available The aim of this study was to verify the reliability of a next generation sequencing (NGS-based method as a strategy to detect all possible BRCA mutations, including large genomic rearrangements. Genomic DNA was obtained from a peripheral blood sample provided by a patient from Southern Italy with early onset breast cancer and a family history of diverse cancers. BRCA molecular analysis was performed by NGS, and sequence data were analyzed using two software packages. Comparative genomic hybridization (CGH array was used as confirmatory method. A novel large duplication, involving exons 4–26, of BRCA2 was directly detected in the patient by NGS workflow including quantitative analysis of copy number variants. The duplication observed was also found by CGH array, thus confirming its extent. Large genomic rearrangements can affect the BRCA1/2 genes, and thus contribute to germline predisposition to familial breast and ovarian cancers. The frequency of these mutations could be underestimated because of technical limitations of several routinely used molecular analysis, while their evaluation should be included also in these molecular testing. The NGS-based strategy described herein is an effective procedure to screen for all kinds of BRCA mutations.

  18. Should excretory urography be used as a routine diagnostic procedure in patients with acute ureteric colic: A single center study

    Directory of Open Access Journals (Sweden)

    Osama A Samara

    2011-01-01

    Full Text Available The aim of this study was to find an accurate, easily available and safe imaging modality as an alternative to intravenous urography for the diagnosis of acute urinary obstruction. This retrospective study included 332 patients, who underwent both excretory urography (EU preceeded by plain radiograph as well as ultrasonography for evaluation of acute flank pain. There were 198 male and 134 female patients. The presence or absence of urinary stones, level of obstruction, excretion delay on EU and dilated excretory system on either or both techniques were recorded. The sensitivity, specificity, predictive values, and accuracy for plain radiograph, ultrasonography, and for both modalities together were measured considering EU as a standard reference. The sensitivity and specificity of combined plain radiograph and ultrasound were 97% and 67%, respectively, with positive and negative predictive values and accuracy rates of 92%, 99%, and 97%, respectively. Our study suggests that the combination of plain radiograph and ultrasonography yields a high sensitivity, negative predictive value, and accuracy in depiction of urinary stones. Thus, EU need not be used as a routine diagnostic procedure in patients with acute obstructive uropathy.

  19. Should excretory urography be used as a routine diagnostic procedure in patients with acute ureteric colic: a single center study.

    Science.gov (United States)

    Samara, Osama A; Haroun, Dina A; Ashour, Do'a Z; Tarawneh, Emad S; Haroun, Azmi A

    2011-05-01

    The aim of this study was to find an accurate, easily available and safe imaging modality as an alternative to intravenous urography for the diagnosis of acute urinary obstruction. This retrospective study included 332 patients, who underwent both excretory urography (EU) preceeded by plain radiograph as well as ultrasonography for evaluation of acute flank pain. There were 198 male and 134 female patients. The presence or absence of urinary stones, level of obstruction, excretion delay on EU and dilated excretory system on either or both techniques were recorded. The sensitivity, specificity, predictive values, and accuracy for plain radiograph, ultrasonography, and for both modalities together were measured considering EU as a standard reference. The sensitivity and specificity of combined plain radiograph and ultrasound were 97% and 67%, respectively, with positive and negative predictive values and accuracy rates of 92%, 99%, and 97%, respectively. Our study suggests that the combination of plain radiograph and ultrasonography yields a high sensitivity, negative predictive value, and accuracy in depiction of urinary stones. Thus, EU need not be used as a routine diagnostic procedure in patients with acute obstructive uropathy.

  20. A novel single-step procedure for the calibration of the mounting parameters of a multi-camera terrestrial mobile mapping system

    Science.gov (United States)

    Habib, A.; Kersting, P.; Bang, K.; Rau, J.

    2011-12-01

    Mobile Mapping Systems (MMS) can be defined as moving platforms which integrates a set of imaging sensors and a position and orientation system (POS) for the collection of geo-spatial information. In order to fully explore the potential accuracy of such systems and guarantee accurate multi-sensor integration, a careful system calibration must be carried out. System calibration involves individual sensor calibration as well as the estimation of the inter-sensor geometric relationship. This paper tackles a specific component of the system calibration process of a multi-camera MMS - the estimation of the relative orientation parameters among the cameras, i.e., the inter-camera geometric relationship (lever-arm offsets and boresight angles among the cameras). For that purpose, a novel single step procedure, which is easy to implement and not computationally intensive, will be introduced. The proposed method is implemented in such a way that it can also be used for the estimation of the mounting parameters among the cameras and the IMU body frame, in case of directly georeferenced systems. The performance of the proposed method is evaluated through experimental results using simulated data. A comparative analysis between the proposed single-step and the two-step, which makes use of the traditional bundle adjustment procedure, is demonstrated.

  1. A stochastic estimation procedure for intermittently-observed semi-Markov multistate models with back transitions.

    Science.gov (United States)

    Aralis, Hilary; Brookmeyer, Ron

    2017-01-01

    Multistate models provide an important method for analyzing a wide range of life history processes including disease progression and patient recovery following medical intervention. Panel data consisting of the states occupied by an individual at a series of discrete time points are often used to estimate transition intensities of the underlying continuous-time process. When transition intensities depend on the time elapsed in the current state and back transitions between states are possible, this intermittent observation process presents difficulties in estimation due to intractability of the likelihood function. In this manuscript, we present an iterative stochastic expectation-maximization algorithm that relies on a simulation-based approximation to the likelihood function and implement this algorithm using rejection sampling. In a simulation study, we demonstrate the feasibility and performance of the proposed procedure. We then demonstrate application of the algorithm to a study of dementia, the Nun Study, consisting of intermittently-observed elderly subjects in one of four possible states corresponding to intact cognition, impaired cognition, dementia, and death. We show that the proposed stochastic expectation-maximization algorithm substantially reduces bias in model parameter estimates compared to an alternative approach used in the literature, minimal path estimation. We conclude that in estimating intermittently observed semi-Markov models, the proposed approach is a computationally feasible and accurate estimation procedure that leads to substantial improvements in back transition estimates.

  2. Modeling urban building energy use: A review of modeling approaches and procedures

    Energy Technology Data Exchange (ETDEWEB)

    Li, Wenliang; Zhou, Yuyu; Cetin, Kristen; Eom, Jiyong; Wang, Yu; Chen, Gang; Zhang, Xuesong

    2017-12-01

    With rapid urbanization and economic development, the world has been experiencing an unprecedented increase in energy consumption and greenhouse gas (GHG) emissions. While reducing energy consumption and GHG emissions is a common interest shared by major developed and developing countries, actions to enable these global reductions are generally implemented at the city scale. This is because baseline information from individual cities plays an important role in identifying economical options for improving building energy efficiency and reducing GHG emissions. Numerous approaches have been proposed for modeling urban building energy use in the past decades. This paper aims to provide an up-to-date review of the broad categories of energy models for urban buildings and describes the basic workflow of physics-based, bottom-up models and their applications in simulating urban-scale building energy use. Because there are significant differences across models with varied potential for application, strengths and weaknesses of the reviewed models are also presented. This is followed by a discussion of challenging issues associated with model preparation and calibration.

  3. A Computational Model of the Temporal Dynamics of Plasticity in Procedural Learning: Sensitivity to Feedback Timing

    Directory of Open Access Journals (Sweden)

    Vivian V. Valentin

    2014-07-01

    Full Text Available The evidence is now good that different memory systems mediate the learning of different types of category structures. In particular, declarative memory dominates rule-based (RB category learning and procedural memory dominates information-integration (II category learning. For example, several studies have reported that feedback timing is critical for II category learning, but not for RB category learning – results that have broad support within the memory systems literature. Specifically, II category learning has been shown to be best with feedback delays of 500ms compared to delays of 0 and 1000ms, and highly impaired with delays of 2.5 seconds or longer. In contrast, RB learning is unaffected by any feedback delay up to 10 seconds. We propose a neurobiologically detailed theory of procedural learning that is sensitive to different feedback delays. The theory assumes that procedural learning is mediated by plasticity at cortical-striatal synapses that are modified by dopamine-mediated reinforcement learning. The model captures the time-course of the biochemical events in the striatum that cause synaptic plasticity, and thereby accounts for the empirical effects of various feedback delays on II category learning.

  4. Modeling of the LA-ICPMS surface rastering procedure to optimize elemental imaging

    International Nuclear Information System (INIS)

    Elteren, J.T. van; Triglav, J.; Selih, V.S.; Zivin, M.

    2009-01-01

    Full text: The quality of elemental image maps generated by LA-ICPMS is a function of the instrumental settings (laser fluence, pulse rate, beam diameter, scanning speed, gas flow rate and acquisition time). Optimizing these settings is a matter of trial and error since quality criteria for elemental imaging (sensitivity, resolution, analysis time) are intricately linked. A theoretical model (and software) will be discussed with which it is possible to simply compute the image distortion introduced by the LA-ICPMS as a function of the instrumental settings and optimize the surface rastering procedure prior to the actual analysis to meet the required quality criteria. (author)

  5. SINGLE PHASE ANALYTICAL MODELS FOR TERRY TURBINE NOZZLE

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Haihua; Zhang, Hongbin; Zou, Ling; O' Brien, James

    2016-11-01

    All BWR RCIC (Reactor Core Isolation Cooling) systems and PWR AFW (Auxiliary Feed Water) systems use Terry turbine, which is composed of the wheel with turbine buckets and several groups of fixed nozzles and reversing chambers inside the turbine casing. The inlet steam is accelerated through the turbine nozzle and impacts on the wheel buckets, generating work to drive the RCIC pump. As part of the efforts to understand the unexpected “self-regulating” mode of the RCIC systems in Fukushima accidents and extend BWR RCIC and PWR AFW operational range and flexibility, mechanistic models for the Terry turbine, based on Sandia National Laboratories’ original work, has been developed and implemented in the RELAP-7 code to simulate the RCIC system. RELAP-7 is a new reactor system code currently under development with the funding support from U.S. Department of Energy. The RELAP-7 code is a fully implicit code and the preconditioned Jacobian-free Newton-Krylov (JFNK) method is used to solve the discretized nonlinear system. This paper presents a set of analytical models for simulating the flow through the Terry turbine nozzles when inlet fluid is pure steam. The implementation of the models into RELAP-7 will be briefly discussed. In the Sandia model, the turbine bucket inlet velocity is provided according to a reduced-order model, which was obtained from a large number of CFD simulations. In this work, we propose an alternative method, using an under-expanded jet model to obtain the velocity and thermodynamic conditions for the turbine bucket inlet. The models include both adiabatic expansion process inside the nozzle and free expansion process out of the nozzle to reach the ambient pressure. The combined models are able to predict the steam mass flow rate and supersonic velocity to the Terry turbine bucket entrance, which are the necessary input conditions for the Terry Turbine rotor model. The nozzle analytical models were validated with experimental data and

  6. Ciliary heterogeneity within a single cell: the Paramecium model.

    Science.gov (United States)

    Aubusson-Fleury, Anne; Cohen, Jean; Lemullois, Michel

    2015-01-01

    Paramecium is a single cell able to divide in its morphologically differentiated stage that has many cilia anchored at its cell surface. Many thousands of cilia are thus assembled in a short period of time during division to duplicate the cell pattern while the cell continues swimming. Most, but not all, of these sensory cilia are motile and involved in two main functions: prey capture and cell locomotion. These cilia display heterogeneity, both in their length and their biochemical properties. Thanks to these properties, as well as to the availability of many postgenomic tools and the possibility to follow the regrowth of cilia after deciliation, Paramecium offers a nice opportunity to study the assembly of the cilia, as well as the genesis of their diversity within a single cell. In this paper, after a brief survey of Paramecium morphology and cilia properties, we describe the tools and the protocols currently used for immunofluorescence, transmission electron microscopy, and ultrastructural immunocytochemistry to analyze cilia, with special recommendations to overcome the problem raised by cilium diversity. Copyright © 2015. Published by Elsevier Inc.

  7. From soil to leaves--aluminum fractionation by single step extraction procedures in polluted and protected areas.

    Science.gov (United States)

    Frankowski, Marcin; Zioła-Frankowska, Anetta; Siepak, Jerzy

    2013-09-30

    The paper presents the fractionation of aluminum in the samples of soil and plants of different species using a selective single-step extraction method. The study was conducted in the area located near a chemical plant, which for many years served as a post-crystallization leachate disposal site storing chemical waste (sector I), and in the area around the site: in Wielkopolski National Park, Rogalin Landscape Park and toward the infiltration ponds at the "Dębina" groundwater well-field for the city of Poznań (Poland) (sector II). The results of aluminum fractionation in samples of soil, leaves and plants showed heavy pollution with aluminum, especially in the water soluble aluminum fraction - Alsw (maximum concentration of aluminum in soil extract was 234.8 ± 4.8 mg kg(-1), in the leaves of Betula pendula it was 107.4 ± 1.8 mg kg(-1) and in the plants of Artemisia vulgaris (root) and Medicago sativa (leaves) it amounted to 464.7 ± 10.7 mg kg(-1)and 146.8 ± 1.2 mg kg(-1) respectively). In addition, the paper presents the problem of organic aluminum fractionation in biological samples and it shows the relationship between aluminum concentration in soil and the analysed woody and herbaceous species. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Single photon emission computed tomography procedure improves accuracy of somatostatin receptor scintigraphy in endocrine gastro-entero-pancreatic tumours

    International Nuclear Information System (INIS)

    Lebtahi, R.; Genin, R.; Rouzet, F.; Bleicner-Perez, S.; Lievre, A.; Scigliano, S.; Vialle, C.; Le Guludec, D.; Cadiot, G.; Sobhani, I.; Mignon, M.

    2005-01-01

    Somatostatin receptors scintigraphy (SRS) is a sensitive method for the detection of endocrine gastro-entero-pancreatic tumors. The aim of this study was to evaluate the sensitivity of anterior and posterior planar associated to single photon emission computerized tomography (SPECT) compared to anterior and posterior planar associated to additional lateral and oblique views in the detection of abdominal endocrine tumors. One hundred and sixty four patients with endocrine gastro-entero-pancreatic tumors were included in this study. Scintigraphic images were performed after injection of 189 ± 23 MBq of 111 In-Pentetreotide. Abdominal planar images were performed 4 h and 24 hours after injection. Abdominal SPECT was performed at 24 hours. The combination of anterior and posterior abdominal planar images with SPECT using iterative reconstruction detected significantly more tumoral sites compared to multiple planar images (298 versus 280 for the liver, p = 0.01 and 90 versus 88 for coeliac area). In particular liver lesions were better delineated on tomographic slices. The combination of 111 In-Pentetreotide SPECT with anterior and posterior planar images is more sensitive than multiple planar images to detect abdominal endocrine tumors. (author)

  9. Defense of single-factor models of population regulation

    International Nuclear Information System (INIS)

    Tamarin, R.H.

    1978-01-01

    I reject a multifactorial approach to the study of the regulation of animal populations for two reasons. First, a mechanism suggested by Chitty, that has natural selection at its base, has not been adequately tested. Second, the multifactorial model suggested by Lidicker is untestable because of its vagueness. As a middle ground, I suggest a model that has natural selection as its mechanism, but is multifacturial because it allows many parameters to be the selective agents. I particularly emphasize prediction and selective dispersal. Methods to test this model are suggested

  10. Mathematical modelling of the combustion of a single wood particle

    Energy Technology Data Exchange (ETDEWEB)

    Porteiro, J.; Miguez, J.L.; Granada, E.; Moran, J.C. [Departamento de Ingenieria Mecanica, Maquinas y Motores Termicos y Fluidos. Universidad de Vigo, Lagoas Marcosende 9 36200 Vigo (Spain)

    2006-01-15

    A mathematical model describing the thermal degradation of densified biomass particles is presented here. The model uses a novel discretisation scheme and combines intra-particle combustion processes with extra-particle transport processes, thereby including thermal and diffusional control mechanisms. The influence of structural changes on the physical-thermal properties of wood in its different stages is studied together with shrinkage of the particle during its degradation. The model is used to compare the predicted data with data on the mass loss dynamics and internal temperature of several particles from previous works and relevant literature, with good agreement. (author)

  11. Single-arm phase II trial design under parametric cure models.

    Science.gov (United States)

    Wu, Jianrong

    2015-01-01

    The current practice of designing single-arm phase II survival trials is limited under the exponential model. Trial design under the exponential model may not be appropriate when a portion of patients are cured. There is no literature available for designing single-arm phase II trials under the parametric cure model. In this paper, a test statistic is proposed, and a sample size formula is derived for designing single-arm phase II trials under a class of parametric cure models. Extensive simulations showed that the proposed test and sample size formula perform very well under different scenarios. Copyright © 2015 John Wiley & Sons, Ltd.

  12. Fitting direct covariance structures by the MSTRUCT modeling language of the CALIS procedure.

    Science.gov (United States)

    Yung, Yiu-Fai; Browne, Michael W; Zhang, Wei

    2015-02-01

    This paper demonstrates the usefulness and flexibility of the general structural equation modelling (SEM) approach to fitting direct covariance patterns or structures (as opposed to fitting implied covariance structures from functional relationships among variables). In particular, the MSTRUCT modelling language (or syntax) of the CALIS procedure (SAS/STAT version 9.22 or later: SAS Institute, 2010) is used to illustrate the SEM approach. The MSTRUCT modelling language supports a direct covariance pattern specification of each covariance element. It also supports the input of additional independent and dependent parameters. Model tests, fit statistics, estimates, and their standard errors are then produced under the general SEM framework. By using numerical and computational examples, the following tests of basic covariance patterns are illustrated: sphericity, compound symmetry, and multiple-group covariance patterns. Specification and testing of two complex correlation structures, the circumplex pattern and the composite direct product models with or without composite errors and scales, are also illustrated by the MSTRUCT syntax. It is concluded that the SEM approach offers a general and flexible modelling of direct covariance and correlation patterns. In conjunction with the use of SAS macros, the MSTRUCT syntax provides an easy-to-use interface for specifying and fitting complex covariance and correlation structures, even when the number of variables or parameters becomes large. © 2014 The British Psychological Society.

  13. Modelling of flow and contaminant migration in single rock fractures

    International Nuclear Information System (INIS)

    Dahlblom, P.; Joensson, L.

    1990-03-01

    The report deals with flow and hydrodynamic dispersion of a nonreactive contaminant in a single, irregularly shaped fracture. The main purpose of the report is to describe the basis and development of a computational 'tool' for simulating the aperture geometry of a single fracture and the detailed flow in it. On the basis of this flow information further properties of the fracture can be studied. Some initial application to dispersion of a nonreactive contaminant are thus discussed. The spatial pattern of variation of the fracture aperture is considered as a two-dimensional stochastic process. A method for simulation of such a process is described. The stochastic properties can be chosen arbitrarily. It is assumed that the fracture aperture belongs to a log-normal distribution. For calculation of the flow pattern, the Navier-Stokes equations are simplified to describe low velocity and steady-state flow. These equations, and the continuity equation are integrated in the direction across the fracture plane. A stream function, which describes the integrated flow in the fracture, is defined. A second order partial differential equation, with respect to the stream function, is established and solved by the finite difference method. Isolines for the stream function define boundaries between channels with equal flow rates. The travel time for each channel can be calculated to achieve a measure of the dispersion. The impact of the aperture distribution on the ratio between the mass balance fracture aperture and the cubic law fracture aperture is shown by simple examples. (28 figs., 1 tab., 22 refs.)

  14. Multi-objective vs. single-objective calibration of a hydrologic model using single- and multi-objective screening

    Science.gov (United States)

    Mai, Juliane; Cuntz, Matthias; Shafii, Mahyar; Zink, Matthias; Schäfer, David; Thober, Stephan; Samaniego, Luis; Tolson, Bryan

    2016-04-01

    Hydrologic models are traditionally calibrated against observed streamflow. Recent studies have shown however, that only a few global model parameters are constrained using this kind of integral signal. They can be identified using prior screening techniques. Since different objectives might constrain different parameters, it is advisable to use multiple information to calibrate those models. One common approach is to combine these multiple objectives (MO) into one single objective (SO) function and allow the use of a SO optimization algorithm. Another strategy is to consider the different objectives separately and apply a MO Pareto optimization algorithm. In this study, two major research questions will be addressed: 1) How do multi-objective calibrations compare with corresponding single-objective calibrations? 2) How much do calibration results deteriorate when the number of calibrated parameters is reduced by a prior screening technique? The hydrologic model employed in this study is a distributed hydrologic model (mHM) with 52 model parameters, i.e. transfer coefficients. The model uses grid cells as a primary hydrologic unit, and accounts for processes like snow accumulation and melting, soil moisture dynamics, infiltration, surface runoff, evapotranspiration, subsurface storage and discharge generation. The model is applied in three distinct catchments over Europe. The SO calibrations are performed using the Dynamically Dimensioned Search (DDS) algorithm with a fixed budget while the MO calibrations are achieved using the Pareto Dynamically Dimensioned Search (PA-DDS) algorithm allowing for the same budget. The two objectives used here are the Nash Sutcliffe Efficiency (NSE) of the simulated streamflow and the NSE of the logarithmic transformation. It is shown that the SO DDS results are located close to the edges of the Pareto fronts of the PA-DDS. The MO calibrations are hence preferable due to their supply of multiple equivalent solutions from which the

  15. Single Canonical Model of Reflexive Memory and Spatial Attention.

    Science.gov (United States)

    Patel, Saumil S; Red, Stuart; Lin, Eric; Sereno, Anne B

    2015-10-23

    Many neurons in the dorsal and ventral visual stream have the property that after a brief visual stimulus presentation in their receptive field, the spiking activity in these neurons persists above their baseline levels for several seconds. This maintained activity is not always correlated with the monkey's task and its origin is unknown. We have previously proposed a simple neural network model, based on shape selective neurons in monkey lateral intraparietal cortex, which predicts the valence and time course of reflexive (bottom-up) spatial attention. In the same simple model, we demonstrate here that passive maintained activity or short-term memory of specific visual events can result without need for an external or top-down modulatory signal. Mutual inhibition and neuronal adaptation play distinct roles in reflexive attention and memory. This modest 4-cell model provides the first simple and unified physiologically plausible mechanism of reflexive spatial attention and passive short-term memory processes.

  16. Procedural Portfolio Planning in Plastic Surgery, Part 2: Collaboration Between Surgeons and Hospital Administrators to Develop a Funds Flow Model for Procedures Performed at an Academic Medical Center.

    Science.gov (United States)

    Hultman, Charles Scott

    2016-06-01

    Although plastic surgeons make important contributions to the clinical, educational, and research missions of academic medical centers (AMCs), determining the financial value of a plastic surgery service can be difficult, due to complex cost accounting systems. We analyzed the financial impact of plastic surgery on an AMC, by examining the contribution margins and operating income of surgical procedures. We collaborated with hospital administrators to implement 3 types of strategic changes: (1) growth of areas with high contribution margin, (2) curtailment of high-risk procedures with negative contribution margin, (3) improved efficiency of mission-critical services with high resource consumption. Outcome measures included: facility charges, hospital collections, contribution margin, operating margin, and operating room times. We also studied the top 50 Current Procedural Terminology codes (total case number × charge/case), ranking procedures for profitability, as determined by operating margin. During the 2-year study period, we had no turnover in faculty; did not pursue any formal marketing; did not change our surgical fees, billing system, or payer mix; and maintained our commitment to indigent care. After rebalancing our case mix, through procedural portfolio planning, average hospital operating income/procedure increased from $-79 to $+816. Volume and diversity of cases increased, with no change in payer mix. Although charges/case decreased, both contribution margin and operating margin increased, due to improved throughput and decreased operating room times. The 5 most profitable procedures for the hospital were hernia repair, mandibular osteotomy, hand skin graft, free fibula flap, and head and neck flap, whereas the 5 least profitable were latissimus breast reconstruction, craniosynostosis repair, free-flap breast reconstruction, trunk skin graft, and cutaneous free flap. Total operating income for the hospital, from plastic surgery procedures, increased

  17. Validation of a single-platform method for hematopoietic CD34+ stem cells enumeration according to accreditation procedure.

    Science.gov (United States)

    Massin, Frédéric; Huili, Cai; Decot, Véronique; Stoltz, Jean-François; Bensoussan, Danièle; Latger-Cannard, Véronique

    2015-01-01

    Stem cells for autologous and allogenic transplantation are obtained from several sources including bone marrow, peripheral blood or cord blood. Accurate enumeration of viable CD34+ hematopoietic stem cells (HSC) is routinely used in clinical settings, especially to monitor progenitor cell mobilization and apheresis. The number of viable CD34+ HSC has also been shown to be the most critical factor in haematopoietic engraftment. The International Society for Cellular Therapy actually recommends the use of single-platform flow cytometry system using 7-AAD as a viability dye. In a way to move routine analysis from a BD FACSCaliburTM instrument to a BD FACSCantoTM II, according to ISO 15189 standard guidelines, we define laboratory performance data of the BDTM Stem Cell Enumeration (SCE) kit on a CE-IVD system including a BD FACSCanto II flow cytometer and the BD FACSCantoTM Clinical Software. InterQCTM software, a real time internet laboratory QC management system developed by VitroTM and distributed by Becton DickinsonTM, was also tested to monitor daily QC data, to define the internal laboratory statistics and to compare them to external laboratories. Precision was evaluated with BDTM Stem Cell Control (high and low) results and the InterQC software, an internet laboratory QC management system by Vitro. This last one drew Levey-Jennings curves and generated numeral statistical parameters allowing detection of potential changes in the system performances as well as interlaboratory comparisons. Repeatability, linearity and lower limits of detection were obtained with routine samples from different origins. Agreement evaluation between BD FACSCanto II system versus BD FACSCalibur system was tested on fresh peripheral blood, freeze-thawed apheresis, fresh bone marrow and fresh cord blood samples. Instrument's measure and staining repeatability clearly evidenced acceptable variability on the different samples tested. Intra- and inter-laboratory CV in CD34+ cell absolute

  18. Estimating multilevel logistic regression models when the number of clusters is low: a comparison of different statistical software procedures.

    Science.gov (United States)

    Austin, Peter C

    2010-04-22

    Multilevel logistic regression models are increasingly being used to analyze clustered data in medical, public health, epidemiological, and educational research. Procedures for estimating the parameters of such models are available in many statistical software packages. There is currently little evidence on the minimum number of clusters necessary to reliably fit multilevel regression models. We conducted a Monte Carlo study to compare the performance of different statistical software procedures for estimating multilevel logistic regression models when the number of clusters was low. We examined procedures available in BUGS, HLM, R, SAS, and Stata. We found that there were qualitative differences in the performance of different software procedures for estimating multilevel logistic models when the number of clusters was low. Among the likelihood-based procedures, estimation methods based on adaptive Gauss-Hermite approximations to the likelihood (glmer in R and xtlogit in Stata) or adaptive Gaussian quadrature (Proc NLMIXED in SAS) tended to have superior performance for estimating variance components when the number of clusters was small, compared to software procedures based on penalized quasi-likelihood. However, only Bayesian estimation with BUGS allowed for accurate estimation of variance components when there were fewer than 10 clusters. For all statistical software procedures, estimation of variance components tended to be poor when there were only five subjects per cluster, regardless of the number of clusters.

  19. The effect on human sex ratio at birth by assisted reproductive technology (ART) procedures--an assessment of babies born following single embryo transfers, Australia and New Zealand, 2002-2006.

    Science.gov (United States)

    Dean, J H; Chapman, M G; Sullivan, E A

    2010-12-01

    To assess the effect on the human sex ratio at birth by assisted reproductive technology (ART) procedures. Retrospective population-based study. Fertility clinics in Australia and New Zealand. The study included 13,368 babies by 13,165 women who had a single embryo transfer (SET) between 2002 and 2006. Logistic regression was used to model the effect on the sex ratio at birth of ART characteristics [in vitro fertilisation (IVF) or intracytoplasmic sperm insemination (ICSI) SET, cleavage-stage or blastocyst SET, and fresh or thawed SET] and biological characteristics (woman's and partner's age and cause of infertility). Proportion of male births. The crude sex ratio at birth was 51.3%. Individual ART procedures had a significant effect on the sex ratio at birth. More males were born following IVF SET (53.0%) than ICSI SET (50.0%), and following blastocyst SET (54.1%) than cleavage-stage SET (49.9%). For a specific ART regimen, IVF blastocyst SET produced more males (56.1%) and ICSI cleavage-stage SET produced fewer males (48.7%). The change in the sex ratio at birth of SET babies is associated with the ART regimen. The mechanism of these effects remains unclear. Fertility clinics and patients should be aware of the bias in the sex ratio at birth when using ART procedures. © 2010 The Authors Journal compilation © RCOG 2010 BJOG An International Journal of Obstetrics and Gynaecology.

  20. Mathematical Modeling in Population Dynamics: The Case of Single ...

    African Journals Online (AJOL)

    kofimereku

    formulated by the logistic growth function, where ε is the intrinsic rate of increase and )0(. ≥. µ represents the effect of intraspecific competition on the reproduction rate. Fisher (1937) first proposed this equation as a model in population genetics to describe the process of spatial spread when mutant individuals with higher ...

  1. Winkler's single-parameter subgrade model from the perspective of ...

    African Journals Online (AJOL)

    ... tensor are taken into consideration, whereas the shear stresses are intentionally dropped with the purpose of providing a useful perspective, with which Winkler's model and its associated coefficient of subgrade reaction can be viewed. The formulation takes into account the variation of the elasticity modulus with depth.

  2. Mathematical modeling in population dynamics: the case of single ...

    African Journals Online (AJOL)

    ... equations are tailored to describing the essential features of a continuous process. The trust of this paper is the application of mathematical models in helping to unravel the underlying mechanisms involved in biological and ecological processes. African Journal of Educational Studies in Mathematics and Sciences Vol.

  3. on the apllication of single specie dynamic population model 306

    African Journals Online (AJOL)

    pc

    used to compare the predicted values and observed values in order to find out whether there is significant difference between the observed and predicted values using these two models. Keywords: Birth rate, sustainable population, overcrowding, harvesting, independent t-test and ..... 95% confidence interval of the.

  4. On the apllication of single specie dynamic population model | Iguda ...

    African Journals Online (AJOL)

    The Method of mathematical models of Malthus and Verhults were applied on ten years data collected from Magaram Poultry Farm to determine the nature of population growth, population decay or constant ... Keywords: Birth rate, sustainable population, overcrowding, harvesting, independent t-test and one way Anova.

  5. Mathematical Model and Calibration Procedure of a PSD Sensor Used in Local Positioning Systems.

    Science.gov (United States)

    Rodríguez-Navarro, David; Lázaro-Galilea, José Luis; Bravo-Muñoz, Ignacio; Gardel-Vicente, Alfredo; Domingo-Perez, Francisco; Tsirigotis, Georgios

    2016-09-15

    Here, we propose a mathematical model and a calibration procedure for a PSD (position sensitive device) sensor equipped with an optical system, to enable accurate measurement of the angle of arrival of one or more beams of light emitted by infrared (IR) transmitters located at distances of between 4 and 6 m. To achieve this objective, it was necessary to characterize the intrinsic parameters that model the system and obtain their values. This first approach was based on a pin-hole model, to which system nonlinearities were added, and this was used to model the points obtained with the nA currents provided by the PSD. In addition, we analyzed the main sources of error, including PSD sensor signal noise, gain factor imbalances and PSD sensor distortion. The results indicated that the proposed model and method provided satisfactory calibration and yielded precise parameter values, enabling accurate measurement of the angle of arrival with a low degree of error, as evidenced by the experimental results.

  6. Semiparametric Mixtures of Regressions with Single-index for Model Based Clustering

    OpenAIRE

    Xiang, Sijia; Yao, Weixin

    2017-01-01

    In this article, we propose two classes of semiparametric mixture regression models with single-index for model based clustering. Unlike many semiparametric/nonparametric mixture regression models that can only be applied to low dimensional predictors, the new semiparametric models can easily incorporate high dimensional predictors into the nonparametric components. The proposed models are very general, and many of the recently proposed semiparametric/nonparametric mixture regression models a...

  7. Modeling refractive metasurfaces in series as a single metasurface

    Science.gov (United States)

    Toor, Fatima; Guneratne, Ananda C.

    2016-03-01

    Metasurfaces are boundaries between two media that are engineered to induce an abrupt phase shift in propagating light over a distance comparable to the wavelength of the light. Metasurface applications exploit this rapid phase shift to allow for precise control of wavefronts. The phase gradient is used to compute the angle at which light is refracted using the generalized Snell's Law. [1] In practice, refractive metasurfaces are designed using a relatively small number of phaseshifting elements such that the phase gradient is discrete rather than continuous. Designing such a metasurface requires finding phase-shifting elements that cover a full range of phases (a phase range) from 0 to 360 degrees. We demonstrate an analytical technique to calculate the refraction angle due to multiple metasurfaces arranged in series without needing to account for the effect of each individual metasurface. The phase gradients of refractive metasurfaces in series may be summed to obtain the phase gradient of a single equivalent refractive metasurface. This result is relevant to any application that requires a system with multiple metasurfaces, such as biomedical imaging [2], wavefront correctors [3], and beam shaping [4].

  8. A Single Model Explains both Visual and Auditory Precortical Coding

    OpenAIRE

    Shan, Honghao; Tong, Matthew H.; Cottrell, Garrison W.

    2016-01-01

    Precortical neural systems encode information collected by the senses, but the driving principles of the encoding used have remained a subject of debate. We present a model of retinal coding that is based on three constraints: information preservation, minimization of the neural wiring, and response equalization. The resulting novel version of sparse principal components analysis successfully captures a number of known characteristics of the retinal coding system, such as center-surround rece...

  9. Single High Fidelity Geometric Data Sets for LCM - Model Requirements

    Science.gov (United States)

    2006-11-01

    triangles (.raw) to the native triangular facet file (.facet). The software vendors recommend the use of McNeil and Associates’ Rhinoceros 3D for all...surface modeling and export. Rhinoceros has the capability and precision to create highly detailed 3D surface geometry suitable for radar cross section... white before ending up at blue as the temperature increases [27]. IR radiation was discovered in 1800 but its application is still limited in

  10. A computational model to investigate assumptions in the headturn preference procedure

    Directory of Open Access Journals (Sweden)

    Christina eBergmann

    2013-10-01

    Full Text Available In this paper we use a computational model to investigate four assumptions that are tacitly present in interpreting the results of studies on infants' speech processing abilities using the Headturn Preference Procedure (HPP: (1 behavioural differences originate in different processing; (2 processing involves some form of recognition; (3 words are segmented from connected speech; and (4 differences between infants should not affect overall results. In addition, we investigate the impact of two potentially important aspects in the design and execution of the experiments: (a the specific voices used in the two parts on HPP experiments (familiarisation and test and (b the experimenter's criterion for what is a sufficient headturn angle. The model is designed to be maximise cognitive plausibility. It takes real speech as input, and it contains a module that converts the output of internal speech processing and recognition into headturns that can yield real-time listening preference measurements. Internal processing is based on distributed episodic representations in combination with a matching procedure based on the assumptions that complex episodes can be decomposed as positive weighted sums of simpler constituents. Model simulations show that the first assumptions hold under two different definitions of recognition. However, explicit segmentation is not necessary to simulate the behaviours observed in infant studies. Differences in attention span between infants can affect the outcomes of an experiment. The same holds for the experimenter's decision criterion. The speakers used in experiments affect outcomes in complex ways that require further investigation. The paper ends with recommendations for future studies using the HPP.

  11. A Spatial Allocation Procedure to Downscale Regional Crop Production Estimates from an Integrated Assessment Model

    Science.gov (United States)

    Moulds, S.; Djordjevic, S.; Savic, D.

    2017-12-01

    The Global Change Assessment Model (GCAM), an integrated assessment model, provides insight into the interactions and feedbacks between physical and human systems. The land system component of GCAM, which simulates land use activities and the production of major crops, produces output at the subregional level which must be spatially downscaled in order to use with gridded impact assessment models. However, existing downscaling routines typically consider cropland as a homogeneous class and do not provide information about land use intensity or specific management practices such as irrigation and multiple cropping. This paper presents a spatial allocation procedure to downscale crop production data from GCAM to a spatial grid, producing a time series of maps which show the spatial distribution of specific crops (e.g. rice, wheat, maize) at four input levels (subsistence, low input rainfed, high input rainfed and high input irrigated). The model algorithm is constrained by available cropland at each time point and therefore implicitly balances extensification and intensification processes in order to meet global food demand. It utilises a stochastic approach such that an increase in production of a particular crop is more likely to occur in grid cells with a high biophysical suitability and neighbourhood influence, while a fall in production will occur more often in cells with lower suitability. User-supplied rules define the order in which specific crops are downscaled as well as allowable transitions. A regional case study demonstrates the ability of the model to reproduce historical trends in India by comparing the model output with district-level agricultural inventory data. Lastly, the model is used to predict the spatial distribution of crops globally under various GCAM scenarios.

  12. Improving the Prediction of Total Surgical Procedure Time Using Linear Regression Modeling

    Directory of Open Access Journals (Sweden)

    Eric R. Edelman

    2017-06-01

    Full Text Available For efficient utilization of operating rooms (ORs, accurate schedules of assigned block time and sequences of patient cases need to be made. The quality of these planning tools is dependent on the accurate prediction of total procedure time (TPT per case. In this paper, we attempt to improve the accuracy of TPT predictions by using linear regression models based on estimated surgeon-controlled time (eSCT and other variables relevant to TPT. We extracted data from a Dutch benchmarking database of all surgeries performed in six academic hospitals in The Netherlands from 2012 till 2016. The final dataset consisted of 79,983 records, describing 199,772 h of total OR time. Potential predictors of TPT that were included in the subsequent analysis were eSCT, patient age, type of operation, American Society of Anesthesiologists (ASA physical status classification, and type of anesthesia used. First, we computed the predicted TPT based on a previously described fixed ratio model for each record, multiplying eSCT by 1.33. This number is based on the research performed by van Veen-Berkx et al., which showed that 33% of SCT is generally a good approximation of anesthesia-controlled time (ACT. We then systematically tested all possible linear regression models to predict TPT using eSCT in combination with the other available independent variables. In addition, all regression models were again tested without eSCT as a predictor to predict ACT separately (which leads to TPT by adding SCT. TPT was most accurately predicted using a linear regression model based on the independent variables eSCT, type of operation, ASA classification, and type of anesthesia. This model performed significantly better than the fixed ratio model and the method of predicting ACT separately. Making use of these more accurate predictions in planning and sequencing algorithms may enable an increase in utilization of ORs, leading to significant financial and productivity related

  13. Improving the Prediction of Total Surgical Procedure Time Using Linear Regression Modeling.

    Science.gov (United States)

    Edelman, Eric R; van Kuijk, Sander M J; Hamaekers, Ankie E W; de Korte, Marcel J M; van Merode, Godefridus G; Buhre, Wolfgang F F A

    2017-01-01

    For efficient utilization of operating rooms (ORs), accurate schedules of assigned block time and sequences of patient cases need to be made. The quality of these planning tools is dependent on the accurate prediction of total procedure time (TPT) per case. In this paper, we attempt to improve the accuracy of TPT predictions by using linear regression models based on estimated surgeon-controlled time (eSCT) and other variables relevant to TPT. We extracted data from a Dutch benchmarking database of all surgeries performed in six academic hospitals in The Netherlands from 2012 till 2016. The final dataset consisted of 79,983 records, describing 199,772 h of total OR time. Potential predictors of TPT that were included in the subsequent analysis were eSCT, patient age, type of operation, American Society of Anesthesiologists (ASA) physical status classification, and type of anesthesia used. First, we computed the predicted TPT based on a previously described fixed ratio model for each record, multiplying eSCT by 1.33. This number is based on the research performed by van Veen-Berkx et al., which showed that 33% of SCT is generally a good approximation of anesthesia-controlled time (ACT). We then systematically tested all possible linear regression models to predict TPT using eSCT in combination with the other available independent variables. In addition, all regression models were again tested without eSCT as a predictor to predict ACT separately (which leads to TPT by adding SCT). TPT was most accurately predicted using a linear regression model based on the independent variables eSCT, type of operation, ASA classification, and type of anesthesia. This model performed significantly better than the fixed ratio model and the method of predicting ACT separately. Making use of these more accurate predictions in planning and sequencing algorithms may enable an increase in utilization of ORs, leading to significant financial and productivity related benefits.

  14. Precipitation projections under GCMs perspective and Turkish Water Foundation (TWF) statistical downscaling model procedures

    Science.gov (United States)

    Dabanlı, İsmail; Şen, Zekai

    2018-04-01

    The statistical climate downscaling model by the Turkish Water Foundation (TWF) is further developed and applied to a set of monthly precipitation records. The model is structured by two phases as spatial (regional) and temporal downscaling of global circulation model (GCM) scenarios. The TWF model takes into consideration the regional dependence function (RDF) for spatial structure and Markov whitening process (MWP) for temporal characteristics of the records to set projections. The impact of climate change on monthly precipitations is studied by downscaling Intergovernmental Panel on Climate Change-Special Report on Emission Scenarios (IPCC-SRES) A2 and B2 emission scenarios from Max Plank Institute (EH40PYC) and Hadley Center (HadCM3). The main purposes are to explain the TWF statistical climate downscaling model procedures and to expose the validation tests, which are rewarded in same specifications as "very good" for all stations except one (Suhut) station in the Akarcay basin that is in the west central part of Turkey. Eventhough, the validation score is just a bit lower at the Suhut station, the results are "satisfactory." It is, therefore, possible to say that the TWF model has reasonably acceptable skill for highly accurate estimation regarding standard deviation ratio (SDR), Nash-Sutcliffe efficiency (NSE), and percent bias (PBIAS) criteria. Based on the validated model, precipitation predictions are generated from 2011 to 2100 by using 30-year reference observation period (1981-2010). Precipitation arithmetic average and standard deviation have less than 5% error for EH40PYC and HadCM3 SRES (A2 and B2) scenarios.

  15. Modeling resonant cavities for single-photon waveguide sources

    International Nuclear Information System (INIS)

    Evans, Philip G.; Bennink, Ryan S.; Grice, Warren P.

    2008-01-01

    Spectral correlations between photon pairs generated by spontaneous parametric down conversion (SPDC) in bulk non-linear optical crystals remain a hindrance to the implementation of efficient quantum communication architectures. It has been demonstrated that SPDC within a distributed micro-cavity can result in little or no correlation between photon pairs. We present results on modeling three different cavity configurations based on integrated Bragg gratings. Output from the SPDC process can be tailored by altering the periodicity and geometry of such nanostructures. We will discuss the merits of each cavity configuration from the standpoint of degenerate Type-II SPDC

  16. MODELING IN MAPLE AS THE RESEARCHING MEANS OF FUNDAMENTAL CONCEPTS AND PROCEDURES IN LINEAR ALGEBRA

    Directory of Open Access Journals (Sweden)

    Vasil Kushnir

    2016-05-01

    -th degree of a square matrix, to calculate matrix exponent, etc. The author creates four basic forms of canonical models of matrices and shows how to design matrices of similar transformations to these four forms. We introduce the programs-procedures for square matrices construction based on the selected models of canonical matrices. Then you can create a certain amount of various square matrices based on canonical matrix models, it allows to use individual learning technologies. The use of Maple-technology allows to automate the cumbersome and complex procedures for finding the transformation matrices of canonical form of a matrix, values of matrices functions, etc., which not only saves time but also attracts attention and efforts on understanding the above mentioned fundamental concepts of linear algebra and procedures for investigation of their properties. All these create favorable conditions for the use of fundamental concepts of linear algebra in scientific and research work of students and undergraduates using Maple-technology

  17. The application of single particle hydrodynamics in continuum models of multiphase flow

    Science.gov (United States)

    Decker, Rand

    1988-01-01

    A review of the application of single particle hydrodynamics in models for the exchange of interphase momentum in continuum models of multiphase flow is presented. Considered are the equations of motion for a laminar, mechanical two phase flow. Inherent to this theory is a model for the interphase exchange of momentum due to drag between the dispersed particulate and continuous fluid phases. In addition, applications of two phase flow theory to de-mixing flows require the modeling of interphase momentum exchange due to lift forces. The applications of single particle analysis in deriving models for drag and lift are examined.

  18. Modeling of 1-D nitrate transport in single layer soils | Dike | Journal ...

    African Journals Online (AJOL)

    The transport of nitrate in laboratory single soil columns of sand, laterite and clay were investigated after 21 days. The 1-D contaminant transport model by Notodarmojo et al (1991) for single layer soils were calibrated and verified using field data collected from a refuse dump site at avu, owerri, Imo state. The experimental ...

  19. Corpuscular Model of Two-Beam Interference and Double-Slit Experiments with Single Photons

    NARCIS (Netherlands)

    Jin, Fengping; Yuan, Shengjun; De Raedt, Hans; Michielsen, Kristel; Miyashita, Seiji

    We introduce an event-based corpuscular simulation model that reproduces the wave mechanical results of single-photon double-slit and two-beam interference experiments and (of a one-to-one copy of an experimental realization) of a single-photon interference experiment with a Fresnel biprism. The

  20. The Use of (-)-Sparteine/Organolithium Reagents for the Enantioselective Lithiation of 7,8-Dipropyltetrathia[7]helicene: Single and Double Kinetic Resolution Procedures.

    Science.gov (United States)

    Doulcet, Julien; Stephenson, G Richard

    2015-12-14

    The effect of organolithium reagent (RLi: R=nBu, iPr, sBu, tBu), solvent (diethyl ether, diethyl ether/THF and MTBE), and stoichiometry on the (-)-sparteine-mediated silylation of 7,8-dipropyltetrathia[7]helicene shows that, unusually, substantially more than 0.5 equivalent of RLi (R=iPr, sBu, tBu) and a large excess of (-)-sparteine (R=nBu, sBu) is often needed to achieve substantial conversions and good ee values. With nBuLi, however, just one equivalent of the organolithium reagent is sufficient to obtain high conversions. Our best results were obtained using the convenient tBuLi/(-)-sparteine adduct with which the need for a high (-)-sparteine/RLi ratio can be avoided. Single- and double-kinetic resolution (KR) procedures give enantiopure samples of 2-trimethylsilyl- and 2,13-di(trimethylsilyl)-7,8-dipropyltetrathia[7]helicene and two-step double-KR combining (-)-sparteine/sBuLi and chiral formamides affords the synthetically valuable 2-formyl-7,8-dipropyltetrathia[7]helicene. This is the first use of (-)-sparteine for the enantioselective lithiation of helicenes and the first report of tBuLi outperforming sBuLi in a (-)-sparteine-mediated procedure. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Sensitivity of tropical convection in cloud-resolving WRF simulations to model physics and forcing procedures

    Science.gov (United States)

    Endo, S.; Lin, W.; Jackson, R. C.; Collis, S. M.; Vogelmann, A. M.; Wang, D.; Oue, M.; Kollias, P.

    2017-12-01

    Tropical convection is one of the main drivers of the climate system and recognized as a major source of uncertainty in climate models. High-resolution modeling is performed with a focus on the deep convection cases during the active monsoon period of the TWP-ICE field campaign to explore ways to improve the fidelity of convection permitting tropical simulations. Cloud resolving model (CRM) simulations are performed with WRF modified to apply flexible configurations for LES/CRM simulations. We have enhanced the capability of the forcing module to test different implementations of large-scale vertical advective forcing, including a function for optional use of large-scale thermodynamic profiles and a function for the condensate advection. The baseline 3D CRM configurations are, following Fridlind et al. (2012), driven by observationally-constrained ARM forcing and tested with diagnosed surface fluxes and fixed sea-surface temperature and prescribed aerosol size distributions. After the spin-up period, the simulations follow the observed precipitation peaks associated with the passages of precipitation systems. Preliminary analysis shows that the simulation is generally not sensitive to the treatment of the large-scale vertical advection of heat and moisture, while more noticeable changes in the peak precipitation rate are produced when thermodynamic profiles above the boundary layer were nudged to the reference profiles from the forcing dataset. The presentation will explore comparisons with observationally-based metrics associated with convective characteristics and examine the model performance with a focus on model physics, doubly-periodic vs. nested configurations, and different forcing procedures/sources. A radar simulator will be used to understand possible uncertainties in radar-based retrievals of convection properties. Fridlind, A. M., et al. (2012), A comparison of TWP-ICE observational data with cloud-resolving model results, J. Geophys. Res., 117, D05204

  2. Single-layer skull approximations perform well in transcranial direct current stimulation modeling

    NARCIS (Netherlands)

    Rampersad, S.M.; Stegeman, D.F.; Oostendorp, T.F.

    2013-01-01

    In modeling the effect of transcranial direct current stimulation, the representation of the skull is an important factor. In a spherical model, we compared a realistic skull modeling approach, in which the skull consisted of three isotropic layers, to anisotropic and isotropic single-layer

  3. Modeling and Control of a Single-Phase Marine Cooling System

    DEFF Research Database (Denmark)

    Hansen, Michael; Stoustrup, Jakob; Bendtsen, Jan Dimon

    2013-01-01

    This paper presents two model-based control design approaches for a single-phase marine cooling system. Models are derived from first principles and aim at describing significant system dynamics including nonlinearities and transport delays, while keeping the model complexity low. The two...

  4. Modeling and optimization of the single-leg multi-fare class ...

    African Journals Online (AJOL)

    This paper presents a static overbooking model for a single-leg multi-fare class flight. A realistic distribution of no-show data in modeling the cost function was considered using data collected from the Ethiopian airlines. The overbooking model developed considers the interaction (i.e. the transfer of an extra passenger in a ...

  5. Modeling methane fluxes in wetlands with gas-transporting plants. 1. Single-root scale

    NARCIS (Netherlands)

    Segers, R.; Leffelaar, P.A.

    2001-01-01

    Methane dynamics in a water-saturated soil layer with gas-transporting roots is modeled with a weighed set of single-root model systems. Each model system consists of a soil cylinder with a gas-transporting root along its axis or a soil sphere with a gas-transporting root at its center. The weights

  6. A Model for Improving the Health and Quality of Life of Single ...

    African Journals Online (AJOL)

    A Model for Improving the Health and Quality of Life of Single Mothers in the Developing World. Rajshri Mainthia, Laura Reppart, Jim Reppart, Elizabeth C Pearce, Jordan J Cohen, James L Netterville ...

  7. A model for analysing factors which may influence quality management procedures in higher education

    Directory of Open Access Journals (Sweden)

    Cătălin MAICAN

    2015-12-01

    Full Text Available In all universities, the Office for Quality Assurance defines the procedure for assessing the performance of the teaching staff, with a view to establishing students’ perception as regards the teachers’ activity from the point of view of the quality of the teaching process, of the relationship with the students and of the assistance provided for learning. The present paper aims at creating a combined model for evaluation, based on Data Mining statistical methods: starting from the findings revealed by the evaluations teachers performed to students, using the cluster analysis and the discriminant analysis, we identified the subjects which produced significant differences between students’ grades, subjects which were subsequently subjected to an evaluation by students. The results of these analyses allowed the formulation of certain measures for enhancing the quality of the evaluation process.

  8. New Inference Procedures for Semiparametric Varying-Coefficient Partially Linear Cox Models

    Directory of Open Access Journals (Sweden)

    Yunbei Ma

    2014-01-01

    Full Text Available In biomedical research, one major objective is to identify risk factors and study their risk impacts, as this identification can help clinicians to both properly make a decision and increase efficiency of treatments and resource allocation. A two-step penalized-based procedure is proposed to select linear regression coefficients for linear components and to identify significant nonparametric varying-coefficient functions for semiparametric varying-coefficient partially linear Cox models. It is shown that the penalized-based resulting estimators of the linear regression coefficients are asymptotically normal and have oracle properties, and the resulting estimators of the varying-coefficient functions have optimal convergence rates. A simulation study and an empirical example are presented for illustration.

  9. Comparison of Model Reliabilities from Single-Step and Bivariate Blending Methods

    DEFF Research Database (Denmark)

    Taskinen, Matti; Mäntysaari, Esa; Lidauer, Martin

    2013-01-01

    the production trait evaluation of Nordic Red dairy cattle. Genotyped bulls with daughters are used as training animals, and genotyped bulls and producing cows as candidate animals. For simplicity, size of the data is chosen so that the full inverses of the mixed model equation coefficient matrices can......Model based reliabilities in genetic evaluation are compared between three methods: animal model BLUP, single-step BLUP, and bivariate blending after genomic BLUP. The original bivariate blending is revised in this work to better account animal models. The study data is extracted from...... be calculated. Model reliabilities by the single-step and the bivariate blending methods were higher than by animal model due to genomic information. Compared to the single-step method, the bivariate blending method reliability estimates were, in general, lower. Computationally bivariate blending method was...

  10. FRP-RC Beam in Shear: Mechanical Model and Assessment Procedure for Pseudo-Ductile Behavior

    Directory of Open Access Journals (Sweden)

    Floriana Petrone

    2014-07-01

    Full Text Available This work deals with the development of a mechanics-based shear model for reinforced concrete (RC elements strengthened in shear with fiber-reinforced polymer (FRP and a design/assessment procedure capable of predicting the failure sequence of resisting elements: the yielding of existing transverse steel ties and the debonding of FRP sheets/strips, while checking the corresponding compressive stress in concrete. The research aims at the definition of an accurate capacity equation, consistent with the requirement of the pseudo-ductile shear behavior of structural elements, that is, transverse steel ties yield before FRP debonding and concrete crushing. For the purpose of validating the proposed model, an extended parametric study and a comparison against experimental results have been conducted: it is proven that the common accepted rule of assuming the shear capacity of RC members strengthened in shear with FRP as the sum of the maximum contribution of both FRP and stirrups can lead to an unsafe overestimation of the shear capacity. This issue has been pointed out by some authors, when comparing experimental shear capacity values with the theoretical ones, but without giving a convincing explanation of that. In this sense, the proposed model represents also a valid instrument to better understand the mechanical behavior of FRP-RC beams in shear and to calculate their actual shear capacity.

  11. Prediction of melting temperatures in fluorescence in situ hybridization (FISH) procedures using thermodynamic models.

    Science.gov (United States)

    Fontenete, Sílvia; Guimarães, Nuno; Wengel, Jesper; Azevedo, Nuno Filipe

    2016-01-01

    The thermodynamics and kinetics of DNA hybridization, i.e. the process of self-assembly of one, two or more complementary nucleic acid strands, has been studied for many years. The appearance of the nearest-neighbor model led to several theoretical and experimental papers on DNA thermodynamics that provide reasonably accurate thermodynamic information on nucleic acid duplexes and allow estimation of the melting temperature. Because there are no thermodynamic models specifically developed to predict the hybridization temperature of a probe used in a fluorescence in situ hybridization (FISH) procedure, the melting temperature is used as a reference, together with corrections for certain compounds that are used during FISH. However, the quantitative relation between melting and experimental FISH temperatures is poorly described. In this review, various models used to predict the melting temperature for rRNA targets, for DNA oligonucleotides and for nucleic acid mimics (chemically modified oligonucleotides), will be addressed in detail, together with a critical assessment of how this information should be used in FISH.

  12. A Novel Murine Model of Arteriovenous Fistula Failure: The Surgical Procedure in Detail.

    Science.gov (United States)

    Wong, Chun Yu; de Vries, Margreet R; Wang, Yang; van der Vorst, Joost R; Vahrmeijer, Alexander L; van Zonneveld, Anton-Jan; Hamming, Jaap F; Roy-Chaudhury, Prabir; Rabelink, Ton J; Quax, Paul H A; Rotmans, Joris I

    2016-02-03

    The arteriovenous fistula (AVF) still suffers from a high number of failures caused by insufficient remodeling and intimal hyperplasia from which the exact pathophysiology remains unknown. In order to unravel the pathophysiology a murine model of AVF-failure was developed in which the configuration of the anastomosis resembles the preferred situation in the clinical setting. A model was described in which an AVF is created by connecting the venous end of the branch of the external jugular vein to the side of the common carotid artery using interrupted sutures. At a histological level, we observed progressive stenotic intimal lesions in the venous outflow tract that is also seen in failed human AVFs. Although this procedure can be technically challenging due to the small dimensions of the animal, we were able to achieve a surgical success rate of 97% after sufficient training. The key advantage of a murine model is the availability of transgenic animals. In view of the different proposed mechanisms that are responsible for AVF failure, disabling genes that might play a role in vascular remodeling can help us to unravel the complex pathophysiology of AVF failure.

  13. A Novel Murine Model of Arteriovenous Fistula Failure: The Surgical Procedure in Detail

    Science.gov (United States)

    Wong, Chun Yu; de Vries, Margreet R.; Wang, Yang; van der Vorst, Joost R.; Vahrmeijer, Alexander L.; van Zonneveld, Anton-Jan; Hamming, Jaap F.; Roy-Chaudhury, Prabir; Rabelink, Ton J.; Quax, Paul H. A.; Rotmans, Joris I.

    2016-01-01

    The arteriovenous fistula (AVF) still suffers from a high number of failures caused by insufficient remodeling and intimal hyperplasia from which the exact pathophysiology remains unknown. In order to unravel the pathophysiology a murine model of AVF-failure was developed in which the configuration of the anastomosis resembles the preferred situation in the clinical setting. A model was described in which an AVF is created by connecting the venous end of the branch of the external jugular vein to the side of the common carotid artery using interrupted sutures. At a histological level, we observed progressive stenotic intimal lesions in the venous outflow tract that is also seen in failed human AVFs. Although this procedure can be technically challenging due to the small dimensions of the animal, we were able to achieve a surgical success rate of 97% after sufficient training. The key advantage of a murine model is the availability of transgenic animals. In view of the different proposed mechanisms that are responsible for AVF failure, disabling genes that might play a role in vascular remodeling can help us to unravel the complex pathophysiology of AVF failure. PMID:26863177

  14. Search procedure for models based on the evolution of experimental curves

    International Nuclear Information System (INIS)

    Delforge, J.

    1975-01-01

    The possibilities offered by numerical analysis regarding the identification of parameters for the model are outlined. The use of a large number of experimental measurements is made possible by the flexibility of the proposed method. It is shown that the errors of numerical identification over all parameters are proportional to experimental errors, and to a proportionality factor called conditioning of the identification problem which is easily computed. Moreover, it is possible to define and calculate, for each parameter, a factor of sensitivity to experimental errors. The numerical values of conditioning and sensitivity factor depend on all experimental conditions, that is, on the one hand, the specific definition of the experiments, and on the other hand, the number and quality of the undertaken measurements. The identification procedure proposed includes several phases. The preliminary phase consists in a first definition of experimental conditions, in agreement with the experimenter. From the data thus obtained, it is generally possible to evaluate the minimum number of equivalence classes required for an interpretation compatible with the morphology of experimental curves. Possibly, from this point, some additional measurements may prove useful or required. The numerical phase comes afterwards to determine a first approximate model by means of the methods previously described. Next phases again require a close collaboration between experimenters and theoreticians. They consist mainly in refining the first model [fr

  15. Models and procedures for interval evaluating the results of control of knowledge in computer systems testing of Navy

    Directory of Open Access Journals (Sweden)

    D. A. Pechnikov

    2018-01-01

    Full Text Available To implement effective military and professional training of Navy specialists, a corresponding educational and material base is needed. As a result of the reduction in the 1990s in the branches of the military-industrial complex developing weapons and equipment for the Navy, the latest models of this technology are now produced not in batches, but in individual copies. The question of the production of training and training samples is not worth it at all. Under these conditions, only virtual analogues of military equipment and weapons, developed by means of information technology, i.e., training and training systems (TOS, can be considered as the only means capable of providing military-professional training. At the modern level of the development of information technologies, testing is the only universal technical means of monitoring the knowledge of students. Procedures for knowledge control in modern computer testing systems do not meet the requirements for them according to the following characteristics: 1 the absence of the possibility of evaluating the error of the test results; 2 the absence of the possibility of stopping testing when the specified reliability of its results is achieved. In order to effectively implement the means of operational criteria-based pedagogical control of knowledge in the process of training specialists of the Navy and to enable joint analysis and processing of evaluations of learning outcomes, it is advisable to implement the following practical recommendations: 1. Formulating the teacher's preferences system regarding the quality of trainee training and the teacher's preferences system in relation to The significance of single test tasks in the test should be considered as the most important The essential steps in preparing a test for practical use. 2. The teacher who first enters the input of his preference systems should check their actual compliance on a sample of 5-10 such test results that cover the full

  16. Model based analysis of the drying of a single solution droplet in an ultrasonic levitator

    DEFF Research Database (Denmark)

    Sloth, Jakob; Kiil, Søren; Jensen, Anker

    2006-01-01

    A model for the drying of a single solution droplet into a solid, dense particle is presented and simulations are made to achieve a more fundamental understanding of the single droplet drying process relevant in connection with spray drying processes. Model predictions of drying behaviour...... are compared to data for the drying of aqueous solutions of maltodextrin DE 15 and trehalose from experiments conducted using an ultrasonic levitator. Model predictions are in good agreement with the experimental data, indicating that the model describes the most important physical phenomena of the process....

  17. Numerical identification procedure between a micro-Cauchy model and a macro-second gradient model for planar pantographic structures

    Science.gov (United States)

    Giorgio, Ivan

    2016-08-01

    In order to design the microstructure of metamaterials showing high toughness in extension (property to be shared with muscles), it has been recently proposed (Dell'Isola et al. in Z Angew Math Phys 66(6):3473-3498, 2015) to consider pantographic structures. It is possible to model such structures at a suitably small length scale (resolving in detail the interconnecting pivots/cylinders) using a standard Cauchy first gradient theory. However, the computational costs for such modelling choice are not allowing for the study of more complex mechanical systems including for instance many pantographic substructures. The microscopic model considered here is a quadratic isotropic Saint-Venant first gradient continuum including geometric nonlinearities and characterized by two Lamé parameters. The introduced macroscopic two-dimensional model for pantographic sheets is characterized by a deformation energy quadratic both in the first and second gradient of placement. However, as underlined in Dell'Isola et al. (Proc R Soc Lond A 472(2185):20150790, 2016), it is needed that the second gradient stiffness depends on the first gradient of placement if large deformations and large displacements configurations must be described. The numerical identification procedure presented in this paper consists in fitting the macro-constitutive parameters using several numerical simulations performed with the micro-model. The parameters obtained by the best fit identification in few deformation problems fit very well also in many others, showing that the reduced proposed model is suitable to get an effective model at relevantly lower computational effort. The presented numerical evidences suggest that a rigorous mathematical homogenization result most likely holds.

  18. An integer batch scheduling model considering learning, forgetting, and deterioration effects for a single machine to minimize total inventory holding cost

    Science.gov (United States)

    Yusriski, R.; Sukoyo; Samadhi, T. M. A. A.; Halim, A. H.

    2018-03-01

    This research deals with a single machine batch scheduling model considering the influenced of learning, forgetting, and machine deterioration effects. The objective of the model is to minimize total inventory holding cost, and the decision variables are the number of batches (N), batch sizes (Q[i], i = 1, 2, .., N) and the sequence of processing the resulting batches. The parts to be processed are received at the right time and the right quantities, and all completed parts must be delivered at a common due date. We propose a heuristic procedure based on the Lagrange method to solve the problem. The effectiveness of the procedure is evaluated by comparing the resulting solution to the optimal solution obtained from the enumeration procedure using the integer composition technique and shows that the average effectiveness is 94%.

  19. Application of a single-objective, hybrid genetic algorithm approach to pharmacokinetic model building.

    Science.gov (United States)

    Sherer, Eric A; Sale, Mark E; Pollock, Bruce G; Belani, Chandra P; Egorin, Merrill J; Ivy, Percy S; Lieberman, Jeffrey A; Manuck, Stephen B; Marder, Stephen R; Muldoon, Matthew F; Scher, Howard I; Solit, David B; Bies, Robert R

    2012-08-01

    A limitation in traditional stepwise population pharmacokinetic model building is the difficulty in handling interactions between model components. To address this issue, a method was previously introduced which couples NONMEM parameter estimation and model fitness evaluation to a single-objective, hybrid genetic algorithm for global optimization of the model structure. In this study, the generalizability of this approach for pharmacokinetic model building is evaluated by comparing (1) correct and spurious covariate relationships in a simulated dataset resulting from automated stepwise covariate modeling, Lasso methods, and single-objective hybrid genetic algorithm approaches to covariate identification and (2) information criteria values, model structures, convergence, and model parameter values resulting from manual stepwise versus single-objective, hybrid genetic algorithm approaches to model building for seven compounds. Both manual stepwise and single-objective, hybrid genetic algorithm approaches to model building were applied, blinded to the results of the other approach, for selection of the compartment structure as well as inclusion and model form of inter-individual and inter-occasion variability, residual error, and covariates from a common set of model options. For the simulated dataset, stepwise covariate modeling identified three of four true covariates and two spurious covariates; Lasso identified two of four true and 0 spurious covariates; and the single-objective, hybrid genetic algorithm identified three of four true covariates and one spurious covariate. For the clinical datasets, the Akaike information criterion was a median of 22.3 points lower (range of 470.5 point decrease to 0.1 point decrease) for the best single-objective hybrid genetic-algorithm candidate model versus the final manual stepwise model: the Akaike information criterion was lower by greater than 10 points for four compounds and differed by less than 10 points for three

  20. Thermal-Hydraulics analysis of pressurized water reactor core by using single heated channel model

    Directory of Open Access Journals (Sweden)

    Reza Akbari

    2017-08-01

    Full Text Available Thermal hydraulics of nuclear reactor as a basis of reactor safety has a very important role in reactor design and control. The thermal-hydraulic analysis provides input data to the reactor-physics analysis, whereas the latter gives information about the distribution of heat sources, which is needed to perform the thermal-hydraulic analysis. In this study single heated channel model as a very fast model for predicting thermal hydraulics behavior of pressurized water reactor core has been developed. For verifying the results of this model, we used RELAP5 code as US nuclear regulatory approved thermal hydraulics code. The results of developed single heated channel model have been checked with RELAP5 results for WWER-1000. This comparison shows the capability of single heated channel model for predicting thermal hydraulics behavior of reactor core.

  1. Transformed model fitting. A straightforward approach to evaluation of anisotropic SANS from nickel-base single-crystal superalloys

    International Nuclear Information System (INIS)

    Strunz, P.

    1999-01-01

    Schematic description of a special evaluation procedure for data treatment of anisotropic Small-Angle Neutron Scattering (SANS) is presented. The use of the discussed procedure is demonstrated on a data taken from investigation of precipitation in single-crystal nickel-base superalloys. (author)

  2. Cost-benefit analysis model: A tool for area-wide fruit fly management. Procedures manual

    International Nuclear Information System (INIS)

    Enkerlin, W.; Mumford, J.; Leach, A.

    2007-03-01

    The Generic Fruit Fly Cost-Benefit Analysis Model assists in economic decision making associated with area-wide fruit fly control options. The FRUIT FLY COST-BENEFIT ANALYSIS PROGRAM (available on 1 CD-ROM from the Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture) is an Excel 2000 Windows based program, for which all standard Windows and Excel conventions apply. The Model is user friendly and thus largely self-explanatory. Nevertheless, it includes a procedures manual that has been prepared to guide the user, and thus should be used together with the software. Please note that the table presenting the pest management options in the Introductory Page of the model is controlled by spin buttons and click boxes. These controls are linked to macros that hide non relevant tables and boxes. N.B. it is important that the medium level of security is selected from the Tools menu of Excel, to do this go to Tools|Macros|Security| and select Medium. When the file is opened a form will appear containing three buttons, click on the middle button, 'Enable Macros', so that the macros may be used. Ideally the model should be used as a support tool by working groups aiming at assessing the economic returns of different fruit fly control options (suppression, eradication, containment and prevention). The working group should include professionals in agriculture with experience in area-wide implementation of integrated pest management programmes, an economist or at least someone with basic knowledge in economics, and if relevant, an entomologist with some background in the application of the sterile insect technique (SIT)

  3. Phoenix – A model-based Human Reliability Analysis methodology: Qualitative Analysis Procedure

    International Nuclear Information System (INIS)

    Ekanem, Nsimah J.; Mosleh, Ali; Shen, Song-Hua

    2016-01-01

    Phoenix method is an attempt to address various issues in the field of Human Reliability Analysis (HRA). Built on a cognitive human response model, Phoenix incorporates strong elements of current HRA good practices, leverages lessons learned from empirical studies, and takes advantage of the best features of existing and emerging HRA methods. Its original framework was introduced in previous publications. This paper reports on the completed methodology, summarizing the steps and techniques of its qualitative analysis phase. The methodology introduces the “Crew Response Tree” which provides a structure for capturing the context associated with Human Failure Events (HFEs), including errors of omission and commission. It also uses a team-centered version of the Information, Decision and Action cognitive model and “macro-cognitive” abstractions of crew behavior, as well as relevant findings from cognitive psychology literature and operating experience, to identify potential causes of failures and influencing factors during procedure-driven and knowledge-supported crew-plant interactions. The result is the set of identified HFEs and likely scenarios leading to each. The methodology itself is generic in the sense that it is compatible with various quantification methods, and can be adapted for use across different environments including nuclear, oil and gas, aerospace, aviation, and healthcare. - Highlights: • Produces a detailed, consistent, traceable, reproducible and properly documented HRA. • Uses “Crew Response Tree” to capture context associated with Human Failure Events. • Models dependencies between Human Failure Events and influencing factors. • Provides a human performance model for relating context to performance. • Provides a framework for relating Crew Failure Modes to its influencing factors.

  4. Emotion regulation strategies: procedure modeling of J. Gross and cultural activity approach

    Directory of Open Access Journals (Sweden)

    Elena I. Pervichko

    2015-03-01

    Full Text Available The first part of this paper argued the desirability of structural-dynamic model of emotion regulation in the theoretical and methodological framework of cultural activity paradigm with the construction of a psychologically-based typology of emotion regulation strategies in norm and pathology, and also psychological mechanisms enabling the regulation of emotions. This conclusion was based on the analysis of the basic concepts and paradigms in which the issue of emotion regulation is studied: cognitive and psychoanalytic approaches, concept and emotional development of emotional intelligence, cultural activity approach. The paper considers the procedure model of emotion regulation by J. Gross, identifies emotion regulation strategies and evaluates their effectiveness. The possibilities and limitations of the model. Based on the review of the today research the conclusion is arrived at that the existing labels on a wide range of regulatory strategies remain an open issue.The author’s definition of emotion regulation is drawn. Emotion regulation is deemed as a set of mental processes, psychological mechanisms and regulatory strategies that people use to preserve the capacity for productive activities in a situation of emotional stress; to ensure optimal impulse control and emotions; to maintain the excitement at the optimum level. The second part of this paper provides the general description of emotion regulation strategies, the approach to their typology, the psychological mechanisms of emotion regulation that lie in the basis of this typology, i.e. the main elements of the structural-dynamic model of emotion regulation. The work shows theoretical and methodological efficacy of empirical significance of signs and symbols and also personal reflection. The diagnostic system to allow empirically identify a wide range of emotion regulation strategies is suggested. The psychological mechanisms used by the subject to solve the problem of emotional

  5. Homogenization procedures for the constitutive material modeling and analysis of aperiodic micro-structures

    Science.gov (United States)

    Aghalaya Manjunatha, Preetham

    Composite materials are the well-known substitutes for traditional metals in various industries because of their micro-structural character. Micro-structures provide a high strength-to-weight ratio, which makes them suitable for manufacturing large variety of applications ranging from simple toys to complicated space/aircraft structures. Since, these materials are widely used in high performance structures, their stress/thermal analysis issues are of major concern. Due to the high degree of material heterogeneity, it is extremely difficult to analyze such structures. Homogenization (rigorous averaging) is a process that overcomes the difficulty of modeling each micro-structure. It replaces an individual micro-structure by an equivalent material model representation (unit cell). Periodic micro-structures appear in regular intervals throughout the domain, in contrast aperiodic micro-structures follows an irregular pattern. Further, this method bridges the analysis gap between micro and macro domain of the structures. In this thesis, Homogenization procedure based on anti-periodic displacement fields for aperiodic micro-structures and aperiodic boundary conditions are considered to model the constitutive material matrix. This work could be easily implemented with the traditional finite element packages. In addition, it eventually increases the convergence accuracy and reduces the high computational expenses. Different problems are analyzed by the implementation of digital image processing schemes for the extraction of a unit cell around the Gauss quadrature points and the mesh-generation. In the future, this research defines a new path for the analysis of any random heterogeneous materials by its ease of implementation and the state-of-the-art micro-structure material modeling capabilities and digital image based micro-meshing.

  6. Generic Procedure for Coupling the PHREEQC Geochemical Modeling Framework with Flow and Solute Transport Simulators

    Science.gov (United States)

    Wissmeier, L. C.; Barry, D. A.

    2009-12-01

    Computer simulations of water availability and quality play an important role in state-of-the-art water resources management. However, many of the most utilized software programs focus either on physical flow and transport phenomena (e.g., MODFLOW, MT3DMS, FEFLOW, HYDRUS) or on geochemical reactions (e.g., MINTEQ, PHREEQC, CHESS, ORCHESTRA). In recent years, several couplings between both genres of programs evolved in order to consider interactions between flow and biogeochemical reactivity (e.g., HP1, PHWAT). Software coupling procedures can be categorized as ‘close couplings’, where programs pass information via the memory stack at runtime, and ‘remote couplings’, where the information is exchanged at each time step via input/output files. The former generally involves modifications of software codes and therefore expert programming skills are required. We present a generic recipe for remotely coupling the PHREEQC geochemical modeling framework and flow and solute transport (FST) simulators. The iterative scheme relies on operator splitting with continuous re-initialization of PHREEQC and the FST of choice at each time step. Since PHREEQC calculates the geochemistry of aqueous solutions in contact with soil minerals, the procedure is primarily designed for couplings to FST’s for liquid phase flow in natural environments. It requires the accessibility of initial conditions and numerical parameters such as time and space discretization in the input text file for the FST and control of the FST via commands to the operating system (batch on Windows; bash/shell on Unix/Linux). The coupling procedure is based on PHREEQC’s capability to save the state of a simulation with all solid, liquid and gaseous species as a PHREEQC input file by making use of the dump file option in the TRANSPORT keyword. The output from one reaction calculation step is therefore reused as input for the following reaction step where changes in element amounts due to advection

  7. Computer Simulation Model to Train Medical Personnel on Glucose Clamp Procedures.

    Science.gov (United States)

    Maghoul, Pooya; Boulet, Benoit; Tardif, Annie; Haidar, Ahmad

    2017-10-01

    A glucose clamp procedure is the most reliable way to quantify insulin pharmacokinetics and pharmacodynamics, but skilled and trained research personnel are required to frequently adjust the glucose infusion rate. A computer environment that simulates glucose clamp experiments can be used for efficient personnel training and development and testing of algorithms for automated glucose clamps. We built 17 virtual healthy subjects (mean age, 25±6 years; mean body mass index, 22.2±3 kg/m 2 ), each comprising a mathematical model of glucose regulation and a unique set of parameters. Each virtual subject simulates plasma glucose and insulin concentrations in response to intravenous insulin and glucose infusions. Each virtual subject provides a unique response, and its parameters were estimated from combined intravenous glucose tolerance test-hyperinsulinemic-euglycemic clamp data using the Bayesian approach. The virtual subjects were validated by comparing their simulated predictions against data from 12 healthy individuals who underwent a hyperglycemic glucose clamp procedure. Plasma glucose and insulin concentrations were predicted by the virtual subjects in response to glucose infusions determined by a trained research staff performing a simulated hyperglycemic clamp experiment. The total amount of glucose infusion was indifferent between the simulated and the real subjects (85±18 g vs. 83±23 g; p=NS) as well as plasma insulin levels (63±20 mU/L vs. 58±16 mU/L; p=NS). The virtual subjects can reliably predict glucose needs and plasma insulin profiles during hyperglycemic glucose clamp conditions. These virtual subjects can be used to train personnel to make glucose infusion adjustments during clamp experiments. Copyright © 2017 Diabetes Canada. Published by Elsevier Inc. All rights reserved.

  8. Procedural Generation of Large-Scale Forests Using a Graph-Based Neutral Landscape Model

    Directory of Open Access Journals (Sweden)

    Jiaqi Li

    2018-03-01

    Full Text Available Specifying the positions and attributes of plants (e.g., species, size, and height during the procedural generation of large-scale forests in virtual geographic environments is challenging, especially when reflecting the characteristics of vegetation distributions. To address this issue, a novel graph-based neutral landscape model (NLM is proposed to generate forest landscapes with varying compositions and configurations. Our model integrates a set of class-level landscape metrics and generates more realistic and variable landscapes compared with existing NLMs controlled by limited global-level landscape metrics. To produce patches with particular sizes and shapes, a region adjacency graph is transformed from a cluster map that is generated based upon percolation theory; subsequently, optimal neighboring nodes in the graph are merged under restricted growth conditions from a source node. The locations of seeds are randomly placed and their species are classified according to the generated forest landscapes to obtain the final tree distributions. The results demonstrate that our method can generate realistic vegetation distributions representing different spatial patterns of species with a time efficiency that satisfies the requirements for constructing large-scale virtual forests.

  9. Acucise™ endopyelotomy in a porcine model: procedure standardization and analysis of safety and immediate efficacy

    Directory of Open Access Journals (Sweden)

    Andreoni Cássio

    2004-01-01

    Full Text Available PURPOSE: The study here presented was done to test the technical reliability and immediate efficacy of the Acucise device using a standardized technique. MATERIALS AND METHODS: 56 Acucise procedures were performed in pigs by a single surgeon who used a standardized technique: insert 5F angiographic catheter bilaterally up to the midureter, perform retrograde pyelogram, Amplatz super-stiff guidewire is advanced up to the level of the renal pelvis, angiographic catheters are removed, Acucise catheter balloon is advanced to the ureteropelvic junction (UPJ level, the super-stiff guide-wire is removed and the contrast medium in the renal pelvis is aspirated and replaced with distilled water, activate Acucise at 75 watts of pure cutting current, keep the balloon fully inflated for 10 minutes, perform retrograde ureteropyelogram to document extravasation, remove Acucise catheter and pass an ureteral stent and remove guide-wire. RESULTS: In no case did the Acucise device present malfunction. The electrocautery activation time was 2.2 seconds (ranging from 2 to 4 seconds. The extravasation of contrast medium, visible by fluoroscopy, occurred in 53 of the 56 cases (94.6%. In no case there was any evidence of intraoperative hemorrhage. CONCLUSIONS: This study revealed that performing Acucise endopyelotomy routinely in a standardized manner could largely preclude intraoperative device malfunction and eliminate complications while achieving a successful incision in the UPJ. With the guidelines that were used in this study, we believe that Acucise endopyelotomy can be completed successfully and safely in the majority of selected patients with UPJ obstruction.

  10. A single-system model predicts recognition memory and repetition priming in amnesia.

    Science.gov (United States)

    Berry, Christopher J; Kessels, Roy P C; Wester, Arie J; Shanks, David R

    2014-08-13

    We challenge the claim that there are distinct neural systems for explicit and implicit memory by demonstrating that a formal single-system model predicts the pattern of recognition memory (explicit) and repetition priming (implicit) in amnesia. In the current investigation, human participants with amnesia categorized pictures of objects at study and then, at test, identified fragmented versions of studied (old) and nonstudied (new) objects (providing a measure of priming), and made a recognition memory judgment (old vs new) for each object. Numerous results in the amnesic patients were predicted in advance by the single-system model, as follows: (1) deficits in recognition memory and priming were evident relative to a control group; (2) items judged as old were identified at greater levels of fragmentation than items judged new, regardless of whether the items were actually old or new; and (3) the magnitude of the priming effect (the identification advantage for old vs new items) overall was greater than that of items judged new. Model evidence measures also favored the single-system model over two formal multiple-systems models. The findings support the single-system model, which explains the pattern of recognition and priming in amnesia primarily as a reduction in the strength of a single dimension of memory strength, rather than a selective explicit memory system deficit. Copyright © 2014 the authors 0270-6474/14/3410963-12$15.00/0.

  11. Modeling and simulation of the zinc-nickel single flow batteries based on MATLAB/Simulink

    Directory of Open Access Journals (Sweden)

    Shouguang Yao

    2016-12-01

    Full Text Available Based on the working principle of the zinc-nickel single flow batteries (ZNBs, this paper builds the electrochemical model and mechanical model, analyzes the effect of electrolyte flux on the battery performance and obtains a single cell with a 216 Ah charge-discharge capacity as an example, and thereafter conducts a simulation to obtain several results under the condition of constant current charge and discharge. The simulation results are well matched in comparison with the experimental results. An optimal flux exists during the charge and discharge, which indicates that the model can well simulate the charge and discharge characteristics of the ZNBs under the condition of constant current.

  12. Overview of software tools for modeling single event upsets in microelectronic devices

    Directory of Open Access Journals (Sweden)

    Anatoly Alexandrovich Smolin

    2016-10-01

    Full Text Available The paper presents the results of the analysis of existing simulation tools for evaluation of single event upset susceptibility of microelectronic devices with deep sub-micron feature sizes. This simulation tools are meant to replace obsolete approach to single event rate estimation based on integral rectangular parallelepiped model. Three main approaches implemented in simulation tools are considered: combined use of particle transport codes and rectangular parallelepiped model, combined use of particle transport codes and analytical models of charge collection and circuit simulators, and combined use of particle transport codes and TCAD simulators.

  13. Comparison of the accuracy of the calibration model on the double and single integrating sphere systems

    CSIR Research Space (South Africa)

    Singh

    2011-05-01

    Full Text Available The accuracy of the calibration model for the single and double integrating sphere systems are compared for a white light system. A calibration model is created from a matrix of samples with known absorption and reduced scattering coefficients...

  14. Effect of the Sport Education Tactical Model on Coeducational and Single Gender Game Performance

    Science.gov (United States)

    Pritchard, Tony; McCollum, Starla; Sundal, Jacqueline; Colquit, Gavin

    2014-01-01

    Physical education teachers are faced with a decision when teaching physical activities in schools. What type of instructional model should be used, and should classes be coeducational or single gender? The current study had two purposes. The first purpose investigated the effectiveness of the sport education tactical model (SETM) during game play…

  15. Numerical models of single- and double-negative metamaterials including viscous and thermal losses

    DEFF Research Database (Denmark)

    Cutanda Henriquez, Vicente; Sánchez-Dehesa, José

    2017-01-01

    detailed understanding on how viscous and thermal losses affect the setups at different frequencies. The modeling of a simpler single-negative metamaterial also broadens this overview. Both setups have been modeled with quadratic BEM meshes. Each sample, scaled at two different sizes, has been represented...

  16. Modelling of Vortex-Induced Loading on a Single-Blade Installation Setup

    DEFF Research Database (Denmark)

    Skrzypinski, Witold Robert; Gaunaa, Mac; Heinz, Joachim Christian

    2016-01-01

    Vortex-induced integral loading fluctuations on a single suspended blade at various inflow angles were modeled in the presents work by means of stochastic modelling methods. The reference time series were obtained by 3D DES CFD computations carried out on the DTU 10MW reference wind turbine blade...

  17. The reverse effects of random perturbation on discrete systems for single and multiple population models

    International Nuclear Information System (INIS)

    Kang, Li; Tang, Sanyi

    2016-01-01

    Highlights: • The discrete single species and multiple species models with random perturbation are proposed. • The complex dynamics and interesting bifurcation behavior have been investigated. • The reverse effects of random perturbation on discrete systems have been discussed and revealed. • The main results can be applied for pest control and resources management. - Abstract: The natural species are likely to present several interesting and complex phenomena under random perturbations, which have been confirmed by simple mathematical models. The important questions are: how the random perturbations influence the dynamics of the discrete population models with multiple steady states or multiple species interactions? and is there any different effects for single species and multiple species models with random perturbation? To address those interesting questions, we have proposed the discrete single species model with two stable equilibria and the host-parasitoid model with Holling type functional response functions to address how the random perturbation affects the dynamics. The main results indicate that the random perturbation does not change the number of blurred orbits of the single species model with two stable steady states compared with results for the classical Ricker model with same random perturbation, but it can strength the stability. However, extensive numerical investigations depict that the random perturbation does not influence the complexities of the host-parasitoid models compared with the results for the models without perturbation, while it does increase the period of periodic orbits doubly. All those confirm that the random perturbation has a reverse effect on the dynamics of the discrete single and multiple population models, which could be applied in reality including pest control and resources management.

  18. A Procedure for Identification of Appropriate State Space and ARIMA Models Based on Time-Series Cross-Validation

    Directory of Open Access Journals (Sweden)

    Patrícia Ramos

    2016-11-01

    Full Text Available In this work, a cross-validation procedure is used to identify an appropriate Autoregressive Integrated Moving Average model and an appropriate state space model for a time series. A minimum size for the training set is specified. The procedure is based on one-step forecasts and uses different training sets, each containing one more observation than the previous one. All possible state space models and all ARIMA models where the orders are allowed to range reasonably are fitted considering raw data and log-transformed data with regular differencing (up to second order differences and, if the time series is seasonal, seasonal differencing (up to first order differences. The value of root mean squared error for each model is calculated averaging the one-step forecasts obtained. The model which has the lowest root mean squared error value and passes the Ljung–Box test using all of the available data with a reasonable significance level is selected among all the ARIMA and state space models considered. The procedure is exemplified in this paper with a case study of retail sales of different categories of women’s footwear from a Portuguese retailer, and its accuracy is compared with three reliable forecasting approaches. The results show that our procedure consistently forecasts more accurately than the other approaches and the improvements in the accuracy are significant.

  19. Comparison of Numerical Modelling of Degradation Mechanisms in Single Mode Optical Fibre Using MATLAB and VPIphotonics

    Directory of Open Access Journals (Sweden)

    Jana Sajgalikova

    2015-01-01

    Full Text Available Mathematical models for description of physical phenomena often use the statistical description of the individual phenomena and solve those using suitable methods. If we want to develop numerical model of optical communication system based on transmission through single mode optical fibres, we need to consider whole series of phenomena that affect various parts of the system. In the single-mode optical fibre we often encounter influence of chromatic dispersion and nonlinear Kerr effects. By observing various different degradation mechanisms, every numerical model should have its own limits, which fulfil more detailed specification. It is inevitable to consider them in evaluation. In this paper, we focus on numerical modelling of degradation mechanisms in single-mode optical fibre. Numerical solution of non-linear Schroedinger equation is performed by finite difference method applied in MATLAB environment and split-step Fourier method, which is implemented by VPIphotonics software.

  20. COMPARISON BETWEEN LAPAROSCOPIC SUTURE RECTOPEXY AND ALTEMEIER'S PROCEDURE FOR THE MANAGEMENT OF COMPLETE RECTAL PROLAPSE- A SINGLE CENTER RETROSPECTIVE OBSERVATIONAL STUDY

    Directory of Open Access Journals (Sweden)

    Balakrishna Nanjundappa Setty

    2017-05-01

    Full Text Available BACKGROUND Rectal prolapse is defined as protrusion of rectal wall through the anal canal. It is further classified into 3 different categories based on the extent of rectal prolapse called partial thickness (mucosal rectal prolapse when only the mucosa is prolapsed through the anal verge, complete rectal prolapse (procidentia involves full thickness of rectal wall prolapsing out of the anal verge and internal rectal prolapse (rectal intussusception involves intussusception of the rectum into the anal canal without protrusion beyond the anal verge. Rectal prolapse can be partial to begin with and may or may not progress to complete rectal prolapse. The aim of our study is to analyse and compare two surgical techniques laparoscopic suture rectopexy and Altemeier’s procedure available for the management of rectal prolapse along with the outcomes of both in a single centre. MATERIALS AND METHODS The study was conducted in Department of Surgical Gastroenterology, Bangalore Medical College and Research Institute, Karnataka. It’s a retrospective observational study conducted between August 2012 and May 2016. The presenting feature, intraoperative events, postoperative course, complications and follow up were noted with regard to faecal incontinence, constipation and recurrent prolapse. RESULTS A total of 35 patients were included in this study. The male-to-female ratio was 1.7:1. The presenting feature being intermittent rectal prolapse in 31 (88%, irreducible rectal prolapse in 2 (5.7% and 2 (5.7% patients were operated for recurrent rectal prolapse. The presenting symptom in the patients were constipation in 14 (40%, incontinence in 5 (14.28% and solitary rectal ulcer syndrome in 3 (8.6%. 20 patients (57.14% underwent laparoscopic suture rectopexy with conversion to open in two patients. 15 (42.8% patients underwent Altemeier’s procedure. The average total duration of hospital stay for patients with suture rectopexy was 3.05263 days and for

  1. Peripheral blood stem cells collection on spectra optia apheresis system using the continuous mononuclear cell collection protocol: A single center report of 39 procedures.

    Science.gov (United States)

    Sanderson, F; Poullin, P; Smith, R; Nicolino-Brunet, C; Philip, P; Chaib, A; Costello, R

    2017-06-01

    The aim of the study was to assess the performance of the new Continuous Mononuclear Cell Collection (CMNC) protocol on the Spectra Optia Apheresis System for collecting autologous Peripheral Blood Stem Cells (PBSC) in adult patients with respect to collection variables, CD34+ cells harvest prediction and engraftment data. In this retrospective study, 39 CMNC procedures on 23 mobilized patients with multiple myeloma and lymphoma were analyzed. CD34+ cells and blood cells yields, collection efficiencies (CE1 and CE2), cell losses were calculated. Engraftment data of 17 autologous transplantations were collected. Apheresis duration was 239 min for a product volume of 220 mL. Cell product haematocrit, MNC and platelets counts were acceptable (respectively 2.4%, 65%, 834 x 109/L). Median platelet loss was 27.3%. Median CD34+ CE1 and CE2 were 64.6% and 48.5% respectively. We harvested 2.92 × 10 6 CD34+ cells/kg, with a CD34 dose ≥ 2 × 10 6 /kg for 67% of the procedures. Linear correlation between preapheresis CD34 count and the CP CD34 dose/kg allowed a prediction model with a decrease trend for high WBC precount. Procedures were well tolerated. For 17 autologous transplantations, median time to neutrophils and platelets reconstitutions were 12 and 13 days respectively. Spectra Optia CMNC protocol successfully collected CD34+ cells with yields permitting the harvest of sufficient enriched grafts for autologous transplantation. The CD34+ cell yield prediction was excellent. PBSC collection with CMNC protocol had advantages of high processing rate, low product volume, and acceptable contamination by platelets. J. Clin. Apheresis 32:182-190, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  2. QAcon: single model quality assessment using protein structural and contact information with machine learning techniques.

    Science.gov (United States)

    Cao, Renzhi; Adhikari, Badri; Bhattacharya, Debswapna; Sun, Miao; Hou, Jie; Cheng, Jianlin

    2017-02-15

    Protein model quality assessment (QA) plays a very important role in protein structure prediction. It can be divided into two groups of methods: single model and consensus QA method. The consensus QA methods may fail when there is a large portion of low quality models in the model pool. In this paper, we develop a novel single-model quality assessment method QAcon utilizing structural features, physicochemical properties, and residue contact predictions. We apply residue-residue contact information predicted by two protein contact prediction methods PSICOV and DNcon to generate a new score as feature for quality assessment. This novel feature and other 11 features are used as input to train a two-layer neural network on CASP9 datasets to predict the quality of a single protein model. We blindly benchmarked our method QAcon on CASP11 dataset as the MULTICOM-CLUSTER server. Based on the evaluation, our method is ranked as one of the top single model QA methods. The good performance of the features based on contact prediction illustrates the value of using contact information in protein quality assessment. The web server and the source code of QAcon are freely available at: http://cactus.rnet.missouri.edu/QAcon. chengji@missouri.edu. Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

  3. Parameter Optimization of Single-Diode Model of Photovoltaic Cell Using Memetic Algorithm

    Directory of Open Access Journals (Sweden)

    Yourim Yoon

    2015-01-01

    Full Text Available This study proposes a memetic approach for optimally determining the parameter values of single-diode-equivalent solar cell model. The memetic algorithm, which combines metaheuristic and gradient-based techniques, has the merit of good performance in both global and local searches. First, 10 single algorithms were considered including genetic algorithm, simulated annealing, particle swarm optimization, harmony search, differential evolution, cuckoo search, least squares method, and pattern search; then their final solutions were used as initial vectors for generalized reduced gradient technique. From this memetic approach, we could further improve the accuracy of the estimated solar cell parameters when compared with single algorithm approaches.

  4. The radiation protection principles model as a tool in the e-waste procedures

    Energy Technology Data Exchange (ETDEWEB)

    Tsitomeneas, S. Th., E-mail: stsit@teipir.gr [Piraeus University of Applied Sciences, Aigaleo (Greece); Vourlias, K., E-mail: kvourlias@yahoo.gr [Aristotle University of Thessaloniki (Greece); Geronikolou, St. A., E-mail: sgeronik@bioacademy.gr [Biomedical Research Foundation Academy of Athens, Athens (Greece)

    2016-03-25

    The electrical and electronic waste (e-waste) management is a global environmental problem dominated by the precautionary principle application, resulted to preliminary and ambiguous potential adverse effects, of extensive scientific uncertainty. In order to overcome the detected stochastic effects confusions in this field, we propose the inclusion of the principles of justification-optimization-limitation and of prudent avoidance. This model is already, established in radiation protection, so that toxicity as a result of the e-waste management would decrease, whilst the precious metals would be saved. We, further, resolve the classification of rejected items as reusable or as waste, so that the procedure of dismantling and recycling becomes easier, and the collecting-transporting-placement at an e-waste landfill would be safer. In conclusion, our proposing pattern in the e-waste management enforces the sustainable reducing-reusing-recycling, saves time/money and advances safety by including more sources of e-waste (military, medical etc) that were excluded previously.

  5. Evaluation of relevant information for optimal reflector modeling through data assimilation procedures

    Directory of Open Access Journals (Sweden)

    Argaud Jean-Philippe

    2015-01-01

    Full Text Available The goal of this study is to look after the amount of information that is mandatory to get a relevant parameters optimisation by data assimilation for physical models in neutronic diffusion calculations, and to determine what is the best information to reach the optimum of accuracy at the cheapest cost. To evaluate the quality of the optimisation, we study the covariance matrix that represents the accuracy of the optimised parameter. This matrix is a classical output of the data assimilation procedure, and it is the main information about accuracy and sensitivity of the parameter optimal determination. From these studies, we present some results collected from the neutronic simulation of nuclear power plants. On the basis of the configuration studies, it has been shown that with data assimilation we can determine a global strategy to optimise the quality of the result with respect to the amount of information provided. The consequence of this is a cost reduction in terms of measurement and/or computing time with respect to the basic approach.

  6. The radiation protection principles model as a tool in the e-waste procedures

    International Nuclear Information System (INIS)

    Tsitomeneas, S. Th.; Vourlias, K.; Geronikolou, St. A.

    2016-01-01

    The electrical and electronic waste (e-waste) management is a global environmental problem dominated by the precautionary principle application, resulted to preliminary and ambiguous potential adverse effects, of extensive scientific uncertainty. In order to overcome the detected stochastic effects confusions in this field, we propose the inclusion of the principles of justification-optimization-limitation and of prudent avoidance. This model is already, established in radiation protection, so that toxicity as a result of the e-waste management would decrease, whilst the precious metals would be saved. We, further, resolve the classification of rejected items as reusable or as waste, so that the procedure of dismantling and recycling becomes easier, and the collecting-transporting-placement at an e-waste landfill would be safer. In conclusion, our proposing pattern in the e-waste management enforces the sustainable reducing-reusing-recycling, saves time/money and advances safety by including more sources of e-waste (military, medical etc) that were excluded previously.

  7. An inverse modeling procedure to determine particle growth and nucleation rates from measured aerosol size distributions

    Directory of Open Access Journals (Sweden)

    B. Verheggen

    2006-01-01

    Full Text Available Classical nucleation theory is unable to explain the ubiquity of nucleation events observed in the atmosphere. This shows a need for an empirical determination of the nucleation rate. Here we present a novel inverse modeling procedure to determine particle nucleation and growth rates based on consecutive measurements of the aerosol size distribution. The particle growth rate is determined by regression analysis of the measured change in the aerosol size distribution over time, taking into account the effects of processes such as coagulation, deposition and/or dilution. This allows the growth rate to be determined with a higher time-resolution than can be deduced from inspecting contour plots ('banana-plots''. Knowing the growth rate as a function of time enables the evaluation of the time of nucleation of measured particles of a certain size. The nucleation rate is then obtained by integrating the particle losses from time of measurement to time of nucleation. The regression analysis can also be used to determine or verify the optimum value of other parameters of interest, such as the wall loss or coagulation rate constants. As an example, the method is applied to smog chamber measurements. This program offers a powerful interpretive tool to study empirical aerosol population dynamics in general, and nucleation and growth in particular.

  8. Ignition and growth modeling of detonation reaction zone experiments on single crystals of PETN and HMX

    Science.gov (United States)

    White, Bradley W.; Tarver, Craig M.

    2017-01-01

    It has long been known that detonating single crystals of solid explosives have much larger failure diameters than those of heterogeneous charges of the same explosive pressed or cast to 98 - 99% theoretical maximum density (TMD). In 1957, Holland et al. demonstrated that PETN single crystals have failure diameters of about 8 mm, whereas heterogeneous PETN charges have failure diameters of less than 0.5 mm. Recently, Fedorov et al. quantitatively determined nanosecond time resolved detonation reaction zone profiles of single crystals of PETN and HMX by measuring the interface particle velocity histories of the detonating crystals and LiF windows using a PDV system. The measured reaction zone time durations for PETN and HMX single crystal detonations were approximately 100 and 260 nanoseconds, respectively. These experiments provided the necessary data to develop Ignition and Growth (I&G) reactive flow model parameters for the single crystal detonation reaction zones. Using these parameters, the calculated unconfined failure diameter of a PETN single crystal was 7.5 +/- 0.5 mm, close to the 8 mm experimental value. The calculated failure diameter of an unconfined HMX single crystal was 15 +/- 1 mm. The unconfined failure diameter of an HMX single crystal has not yet been determined precisely, but Fedorov et al. detonated 14 mm diameter crystals confined by detonating a HMX-based plastic bonded explosive (PBX) without initially overdriving the HMX crystals.

  9. The Relationship between the Bock-Aitkin Procedure and the EM Algorithm for IRT Model Estimation.

    Science.gov (United States)

    Hsu, Yaowen; Ackerman, Terry A.; Fan, Meichu

    It has previously been shown that the Bock-Aitkin procedure (R. Bock and M. Aitkin, 1981) is an instance of the EM algorithm when trying to find the marginal maximum likelihood estimate for a discrete latent ability variable (latent trait). In this paper, it is shown that the Bock-Aitkin procedure is a numerical implementation of the EM algorithm…

  10. Single, Integrated, Service-Centric Model of Military Health System Governance

    Science.gov (United States)

    that keeps pace with the operational agility and organizational flexibility requirements to support globally integrated operations is clear. This...of the research is to establish what the model of governance of the Military Health System should be. That, with other recommendations, should be the...foundation for the impending transformation. The research found that the model of governance should be a single service model with regional health

  11. A generalized Jaynes-Cummings model: The relativistic parametric amplifier and a single trapped ion

    Energy Technology Data Exchange (ETDEWEB)

    Ojeda-Guillén, D., E-mail: dojedag@ipn.mx [Escuela Superior de Cómputo, Instituto Politécnico Nacional, Av. Juan de Dios Bátiz esq. Av. Miguel Othón de Mendizábal, Col. Lindavista, Delegación Gustavo A. Madero, C.P. 07738 Ciudad de México (Mexico); Mota, R. D. [Escuela Superior de Ingeniería Mecánica y Eléctrica, Unidad Culhuacán, Instituto Politécnico Nacional, Av. Santa Ana No. 1000, Col. San Francisco Culhuacán, Delegación Coyoacán, C.P. 04430 Ciudad de México (Mexico); Granados, V. D. [Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional, Ed. 9, Unidad Profesional Adolfo López Mateos, Delegación Gustavo A. Madero, C.P. 07738 Ciudad de México (Mexico)

    2016-06-15

    We introduce a generalization of the Jaynes-Cummings model and study some of its properties. We obtain the energy spectrum and eigenfunctions of this model by using the tilting transformation and the squeezed number states of the one-dimensional harmonic oscillator. As physical applications, we connect this new model to two important and novelty problems: the relativistic parametric amplifier and the quantum simulation of a single trapped ion.

  12. Cost Assessment of Three Power Decoupling Methods in a Single-phase Power Converter with a Reliability-oriented Design Procedure

    DEFF Research Database (Denmark)

    Wang, Haoran; Wang, Huai; Zhu, Guorong

    2016-01-01

    methods and the classical passive DC-link design method are evaluated from the reliability and cost perspective. The reliability-oriented design procedure is applied to size the chip area of active switching devices and the passive components to fulfill a specific lifetime target. Component cost models...... are applied to obtain the overall cost of each DC-link design methods. The cost comparisons are performed with a lifetime target of 10 years and 35 years. It reveals that different conclusions can be drawn with different lifetime targets in terms of cost-effectiveness.......-Caps qualitatively, making great effort to diverting the instantaneous pulsation power into extra reliable storage components. However, it is still an open question, which method is the most cost-effective one for a specific application with a given lifetime requirement. In this paper, two of the representative APD...

  13. Modal analysis based equivalent circuit model and its verification for a single cMUT cell

    International Nuclear Information System (INIS)

    Mao, S P; Rottenberg, X; Rochus, V; Czarnecki, P; Helin, P; Severi, S; Tilmans, H A C; Nauwelaers, B

    2017-01-01

    This paper presents the lumped equivalent circuit model and its verification of both transmission and reception properties of a single cell capacitive micromachined ultrasonic transducer (cMUT), which is operating in a non-collapse small signal region. The derivation of this equivalent circuit model is based on the modal analysis techniques, harmonic modes are included by using the mode superposition method; and thus a wide frequency range response of the cMUT cell can be simulated by our equivalent circuit model. The importance of the cross modal coupling between different eigenmodes of a cMUT cell is discussed by us for the first time. In this paper the development of this model is only illustrated by a single circular cMUT cell under a uniform excitation. Extension of this model and corresponding results under a more generalized excitation will be presented in our upcoming publication (Mao et al 2016 Proc. IEEE Int. Ultrasonics Symp .). This model is verified by both finite element method (FEM) simulation and experimental characterizations. Results predicted by our model are in a good agreement with the FEM simulation results, and this works for a single cMUT cell operated in either transmission or reception. Results obtained from the model also rather match the experimental results of the cMUT cell. This equivalent circuit model provides an easy and precise way to rapidly predict the behaviors of cMUT cells. (paper)

  14. Modal analysis based equivalent circuit model and its verification for a single cMUT cell

    Science.gov (United States)

    Mao, S. P.; Rottenberg, X.; Rochus, V.; Czarnecki, P.; Helin, P.; Severi, S.; Nauwelaers, B.; Tilmans, H. A. C.

    2017-03-01

    This paper presents the lumped equivalent circuit model and its verification of both transmission and reception properties of a single cell capacitive micromachined ultrasonic transducer (cMUT), which is operating in a non-collapse small signal region. The derivation of this equivalent circuit model is based on the modal analysis techniques, harmonic modes are included by using the mode superposition method; and thus a wide frequency range response of the cMUT cell can be simulated by our equivalent circuit model. The importance of the cross modal coupling between different eigenmodes of a cMUT cell is discussed by us for the first time. In this paper the development of this model is only illustrated by a single circular cMUT cell under a uniform excitation. Extension of this model and corresponding results under a more generalized excitation will be presented in our upcoming publication (Mao et al 2016 Proc. IEEE Int. Ultrasonics Symp.). This model is verified by both finite element method (FEM) simulation and experimental characterizations. Results predicted by our model are in a good agreement with the FEM simulation results, and this works for a single cMUT cell operated in either transmission or reception. Results obtained from the model also rather match the experimental results of the cMUT cell. This equivalent circuit model provides an easy and precise way to rapidly predict the behaviors of cMUT cells.

  15. An update on single field models of inflation in light of WMAP7

    International Nuclear Information System (INIS)

    Alabidi, Laila; Huston, Ian

    2010-01-01

    In this paper we summarise the status of single field models of inflation in light of the WMAP 7 data release. We find little has changed since the 5 year release, and results are consistent with previous findings. The increase in the upper bound on the running of the spectral index impacts on the status of the production of Primordial Black Holes from single field models. The lower bound on f equi NL is reduced and thus the bounds on the theoretical parameters of (UV) DBI single brane models are weakened. In the case of multiple coincident branes the bounds are also weakened and the two, three or four brane cases will produce a tensor-signal that could possibly be observed in the future

  16. Extension of an anisotropic creep model to general high temperature deformation of a single crystal superalloy

    International Nuclear Information System (INIS)

    Pan, L.M.; Ghosh, R.N.; McLean, M.

    1993-01-01

    A physics based model has been developed that accounts for the principal features of anisotropic creep deformation of single crystal superalloys. The present paper extends this model to simulate other types of high temperature deformation under strain controlled test conditions, such as stress relaxation and tension tests at constant strain rate in single crystals subject to axial loading along an arbitrary crystal direction. The approach is applied to the SRR99 single crystal superalloy where a model parameter database is available, determined via analysis of a database of constant stress creep curves. A software package has been generated to simulate the deformation behaviour under complex stress-strain conditions taking into account anisotropic elasticity. (orig.)

  17. Should researchers use single indicators, best indicators, or multiple indicators in structural equation models?

    Directory of Open Access Journals (Sweden)

    Hayduk Leslie A

    2012-10-01

    Full Text Available Abstract Background Structural equation modeling developed as a statistical melding of path analysis and factor analysis that obscured a fundamental tension between a factor preference for multiple indicators and path modeling’s openness to fewer indicators. Discussion Multiple indicators hamper theory by unnecessarily restricting the number of modeled latents. Using the few best indicators – possibly even the single best indicator of each latent – encourages development of theoretically sophisticated models. Additional latent variables permit stronger statistical control of potential confounders, and encourage detailed investigation of mediating causal mechanisms. Summary We recommend the use of the few best indicators. One or two indicators are often sufficient, but three indicators may occasionally be helpful. More than three indicators are rarely warranted because additional redundant indicators provide less research benefit than single indicators of additional latent variables. Scales created from multiple indicators can introduce additional problems, and are prone to being less desirable than either single or multiple indicators.

  18. SITE-94. Discrete-feature modelling of the Aespoe site: 4. Source data and detailed analysis procedures

    International Nuclear Information System (INIS)

    Geier, J.E.

    1996-12-01

    Specific procedures and source data are described for the construction and application of discrete-feature hydrological models for the vicinity of Aespoe. Documentation is given for all major phases of the work, including: Statistical analyses to develop and validate discrete-fracture network models, Preliminary evaluation, construction, and calibration of the site-scale model based on the SITE-94 structural model of Aespoe, Simulation of multiple realizations of the integrated model, and variations, to predict groundwater flow, and Evaluation of near-field and far-field parameters for performance assessment calculations. Procedures are documented in terms of the computer batch files and executable scripts that were used to perform the main steps in these analyses, to provide for traceability of results that are used in the SITE-94 performance assessment calculations. 43 refs

  19. SVMQA: support-vector-machine-based protein single-model quality assessment.

    Science.gov (United States)

    Manavalan, Balachandran; Lee, Jooyoung

    2017-08-15

    The accurate ranking of predicted structural models and selecting the best model from a given candidate pool remain as open problems in the field of structural bioinformatics. The quality assessment (QA) methods used to address these problems can be grouped into two categories: consensus methods and single-model methods. Consensus methods in general perform better and attain higher correlation between predicted and true quality measures. However, these methods frequently fail to generate proper quality scores for native-like structures which are distinct from the rest of the pool. Conversely, single-model methods do not suffer from this drawback and are better suited for real-life applications where many models from various sources may not be readily available. In this study, we developed a support-vector-machine-based single-model global quality assessment (SVMQA) method. For a given protein model, the SVMQA method predicts TM-score and GDT_TS score based on a feature vector containing statistical potential energy terms and consistency-based terms between the actual structural features (extracted from the three-dimensional coordinates) and predicted values (from primary sequence). We trained SVMQA using CASP8, CASP9 and CASP10 targets and determined the machine parameters by 10-fold cross-validation. We evaluated the performance of our SVMQA method on various benchmarking datasets. Results show that SVMQA outperformed the existing best single-model QA methods both in ranking provided protein models and in selecting the best model from the pool. According to the CASP12 assessment, SVMQA was the best method in selecting good-quality models from decoys in terms of GDTloss. SVMQA method can be freely downloaded from http://lee.kias.re.kr/SVMQA/SVMQA_eval.tar.gz. jlee@kias.re.kr. Supplementary data are available at Bioinformatics online. © The Author (2017). Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  20. Calibration and Validation Parameter of Hydrologic Model HEC-HMS using Particle Swarm Optimization Algorithms – Single Objective

    Directory of Open Access Journals (Sweden)

    R. Garmeh

    2016-02-01

    Full Text Available Introduction: Planning and management of water resource and river basins needs use of conceptual hydrologic models which play a significant role in predicting basins response to different climatic and meteorological processes. Evaluating watershed response through mathematical hydrologic models requires finding a set of parameter values of the model which provides thebest fit between observed and estimated hydrographs in a procedure called calibration. Asmanual calibration is tedious, time consuming and requires personal experience, automaticcalibration methods make application of more significant CRR models which are based onusing a systematic search procedure to find good parameter sets in terms of at least oneobjective function. Materials and Methods: Conceptual hydrologic models play a significant role inpredicting a basin’s response to different climatic and meteorological processes within natural systems. However, these models require a number of estimated parameters. Model calibration is the procedure of adjusting the parametervalues until the model predictions match the observed data. Manual calibration of high-fidelity hydrologic (simulation models is tedious, time consuming and sometimesimpractical, especially when the number of parameters islarge. Moreover, the high degrees of nonlinearity involved in different hydrologic processes and non-uniqueness ofinverse-type calibration problems make it difficult to find asingle set of parameter values. In this research, the conceptual HEC-HMS model is integrated with the Particle Swarm Optimization (PSO algorithm.The HEC-HMS model was developed as areplacement for HEC-1, which has long been considered as astandard model for hydrologic simulation. Most of thehydrologic models employed in HEC-HMS are event-basedmodels simulating a single storm requiring the specificationof all conditions at the beginning of the simulation. The soil moistureaccounting model in the HEC-HMS is the onlycontinuous

  1. Quantitative modeling of the accuracy in registering preoperative patient-specific anatomic models into left atrial cardiac ablation procedures.

    Science.gov (United States)

    Rettmann, Maryam E; Holmes, David R; Kwartowitz, David M; Gunawan, Mia; Johnson, Susan B; Camp, Jon J; Cameron, Bruce M; Dalegrave, Charles; Kolasa, Mark W; Packer, Douglas L; Robb, Richard A

    2014-02-01

    In cardiac ablation therapy, accurate anatomic guidance is necessary to create effective tissue lesions for elimination of left atrial fibrillation. While fluoroscopy, ultrasound, and electroanatomic maps are important guidance tools, they lack information regarding detailed patient anatomy which can be obtained from high resolution imaging techniques. For this reason, there has been significant effort in incorporating detailed, patient-specific models generated from preoperative imaging datasets into the procedure. Both clinical and animal studies have investigated registration and targeting accuracy when using preoperative models; however, the effect of various error sources on registration accuracy has not been quantitatively evaluated. Data from phantom, canine, and patient studies are used to model and evaluate registration accuracy. In the phantom studies, data are collected using a magnetically tracked catheter on a static phantom model. Monte Carlo simulation studies were run to evaluate both baseline errors as well as the effect of different sources of error that would be present in a dynamic in vivo setting. Error is simulated by varying the variance parameters on the landmark fiducial, physical target, and surface point locations in the phantom simulation studies. In vivo validation studies were undertaken in six canines in which metal clips were placed in the left atrium to serve as ground truth points. A small clinical evaluation was completed in three patients. Landmark-based and combined landmark and surface-based registration algorithms were evaluated in all studies. In the phantom and canine studies, both target registration error and point-to-surface error are used to assess accuracy. In the patient studies, no ground truth is available and registration accuracy is quantified using point-to-surface error only. The phantom simulation studies demonstrated that combined landmark and surface-based registration improved landmark-only registration

  2. Quantitative modeling of the accuracy in registering preoperative patient-specific anatomic models into left atrial cardiac ablation procedures

    Energy Technology Data Exchange (ETDEWEB)

    Rettmann, Maryam E., E-mail: rettmann.maryam@mayo.edu; Holmes, David R.; Camp, Jon J.; Cameron, Bruce M.; Robb, Richard A. [Biomedical Imaging Resource, Mayo Clinic College of Medicine, Rochester, Minnesota 55905 (United States); Kwartowitz, David M. [Department of Bioengineering, Clemson University, Clemson, South Carolina 29634 (United States); Gunawan, Mia [Department of Biochemistry and Molecular and Cellular Biology, Georgetown University, Washington D.C. 20057 (United States); Johnson, Susan B.; Packer, Douglas L. [Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota 55905 (United States); Dalegrave, Charles [Clinical Cardiac Electrophysiology, Cardiology Division Hospital Sao Paulo, Federal University of Sao Paulo, 04024-002 Brazil (Brazil); Kolasa, Mark W. [David Grant Medical Center, Fairfield, California 94535 (United States)

    2014-02-15

    Purpose: In cardiac ablation therapy, accurate anatomic guidance is necessary to create effective tissue lesions for elimination of left atrial fibrillation. While fluoroscopy, ultrasound, and electroanatomic maps are important guidance tools, they lack information regarding detailed patient anatomy which can be obtained from high resolution imaging techniques. For this reason, there has been significant effort in incorporating detailed, patient-specific models generated from preoperative imaging datasets into the procedure. Both clinical and animal studies have investigated registration and targeting accuracy when using preoperative models; however, the effect of various error sources on registration accuracy has not been quantitatively evaluated. Methods: Data from phantom, canine, and patient studies are used to model and evaluate registration accuracy. In the phantom studies, data are collected using a magnetically tracked catheter on a static phantom model. Monte Carlo simulation studies were run to evaluate both baseline errors as well as the effect of different sources of error that would be present in a dynamicin vivo setting. Error is simulated by varying the variance parameters on the landmark fiducial, physical target, and surface point locations in the phantom simulation studies. In vivo validation studies were undertaken in six canines in which metal clips were placed in the left atrium to serve as ground truth points. A small clinical evaluation was completed in three patients. Landmark-based and combined landmark and surface-based registration algorithms were evaluated in all studies. In the phantom and canine studies, both target registration error and point-to-surface error are used to assess accuracy. In the patient studies, no ground truth is available and registration accuracy is quantified using point-to-surface error only. Results: The phantom simulation studies demonstrated that combined landmark and surface-based registration improved

  3. [Compared Markov with fractal models by using single-channel experimental and simulation data].

    Science.gov (United States)

    Lan, Tonghan; Wu, Hongxiu; Lin, Jiarui

    2006-10-01

    The gating mechanical kinetical of ion channels has been modeled as a Markov process. In these models it is assumed that the channel protein has a small number of discrete conformational states and kinetic rate constants connecting these states are constant, the transition rate constants among the states is independent both of time and of the previous channel activity. It is assumed in Liebovitch's fractal model that the channel exists in an infinite number of energy states, consequently, transitions from one conductance state to another would be governed by a continuum of rate constants. In this paper, a statistical comparison is presented of Markov and fractal models of ion channel gating, the analysis is based on single-channel data from ion channel voltage-dependence K+ single channel of neuron cell and simulation data from three-states Markov model.

  4. Modelling a short-wake meteor as a single or fragmenting body

    Science.gov (United States)

    Campbell-Brown, M.

    2017-09-01

    An attempt is made to model a meteor observed with the Canadian Automated Meteor Observatory tracking system using a single body model. This meteor showed only very faint wake, implying that fragmentation was not important. Previous attempts to model the meteor with models of fragmenting meteors had overpredicted the amount of wake seen. A single-body, non-homogeneous ablation code was developed, but proved unsuccessful at matching the observed light curve of the meteor, even after a thorough search of parameter space. A model of a meteoroid fragmenting in many small bursts of small fragments was developed in an attempt to match both the light curve and the observed wake, and it succeeded in producing a qualitative fit to the light curve and to the high-resolution wake.

  5. [Three dimensional finite element model of a modified posterior cervical single open-door laminoplasty].

    Science.gov (United States)

    Wang, Q; Yang, Y; Fei, Q; Li, D; Li, J J; Meng, H; Su, N; Fan, Z H; Wang, B Q

    2017-06-06

    Objective: To build a three-dimensional finite element models of a modified posterior cervical single open-door laminoplasty with short-segmental lateral mass screws fusion. Methods: The C(2)-C(7) segmental data were obtained from computed tomography (CT) scans of a male patient with cervical spondylotic myelopathy and spinal stenosis.Three-dimensional finite element models of a modified cervical single open-door laminoplasty (before and after surgery) were constructed by the combination of software package MIMICS, Geomagic and ABAQUS.The models were composed of bony vertebrae, articulating facets, intervertebral disc and associated ligaments.The loads of moments 1.5Nm at different directions (flexion, extension, lateral bending and axial rotation)were applied at preoperative model to calculate intersegmental ranges of motion.The results were compared with the previous studies to verify the validation of the models. Results: Three-dimensional finite element models of the modified cervical single open- door laminoplasty had 102258 elements (preoperative model) and 161 892 elements (postoperative model) respectively, including C(2-7) six bony vertebraes, C(2-3)-C(6-7) five intervertebral disc, main ligaments and lateral mass screws.The intersegmental responses at the preoperative model under the loads of moments 1.5 Nm at different directions were similar to the previous published data. Conclusion: Three-dimensional finite element models of the modified cervical single open- door laminoplasty were successfully established and had a good biological fidelity, which can be used for further study.

  6. CFD Modelling and Validation of Mixing in a Model Single-Use-Technology Bioreactor

    OpenAIRE

    Maltby, Richard; Chew, Yong-Min

    2016-01-01

    Single-use-technologies (SUT) are a category of disposable bioprocessing components which have increased in popularity in the biopharmaceutical industry in recent years [1]. Stirred single use bioreactors use a polymeric bag supported by a rigid metal frame. The bag is disposed of and replaced after use, removing the need for energy-intensive and time consuming cleaning and sterilisation in place, as well as improving the flexibility of the production facility [2]. They are currently applied ...

  7. Finite state projection based bounds to compare chemical master equation models using single-cell data

    Energy Technology Data Exchange (ETDEWEB)

    Fox, Zachary [School of Biomedical Engineering, Colorado State University, Fort Collins, Colorado 80523 (United States); Neuert, Gregor [Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee 37232 (United States); Department of Pharmacology, School of Medicine, Vanderbilt University, Nashville, Tennessee 37232 (United States); Department of Biomedical Engineering, Vanderbilt University School of Engineering, Nashville, Tennessee 37232 (United States); Munsky, Brian [School of Biomedical Engineering, Colorado State University, Fort Collins, Colorado 80523 (United States); Department of Chemical and Biological Engineering, Colorado State University, Fort Collins, Colorado 80523 (United States)

    2016-08-21

    Emerging techniques now allow for precise quantification of distributions of biological molecules in single cells. These rapidly advancing experimental methods have created a need for more rigorous and efficient modeling tools. Here, we derive new bounds on the likelihood that observations of single-cell, single-molecule responses come from a discrete stochastic model, posed in the form of the chemical master equation. These strict upper and lower bounds are based on a finite state projection approach, and they converge monotonically to the exact likelihood value. These bounds allow one to discriminate rigorously between models and with a minimum level of computational effort. In practice, these bounds can be incorporated into stochastic model identification and parameter inference routines, which improve the accuracy and efficiency of endeavors to analyze and predict single-cell behavior. We demonstrate the applicability of our approach using simulated data for three example models as well as for experimental measurements of a time-varying stochastic transcriptional response in yeast.

  8. Spatial distribution of mineral dust single scattering albedo based on DREAM model

    Science.gov (United States)

    Kuzmanoski, Maja; Ničković, Slobodan; Ilić, Luka

    2016-04-01

    Mineral dust comprises a significant part of global aerosol burden. There is a large uncertainty in estimating role of dust in Earth's climate system, partly due to poor characterization of its optical properties. Single scattering albedo is one of key optical properties determining radiative effects of dust particles. While it depends on dust particle sizes, it is also strongly influenced by dust mineral composition, particularly the content of light-absorbing iron oxides and the mixing state (external or internal). However, an assumption of uniform dust composition is typically used in models. To better represent single scattering albedo in dust atmospheric models, required to increase accuracy of dust radiative effect estimates, it is necessary to include information on particle mineral content. In this study, we present the spatial distribution of dust single scattering albedo based on the Dust Regional Atmospheric Model (DREAM) with incorporated particle mineral composition. The domain of the model covers Northern Africa, Middle East and the European continent, with horizontal resolution set to 1/5°. It uses eight particle size bins within the 0.1-10 μm radius range. Focusing on dust episode of June 2010, we analyze dust single scattering albedo spatial distribution over the model domain, based on particle sizes and mineral composition from model output; we discuss changes in this optical property after long-range transport. Furthermore, we examine how the AERONET-derived aerosol properties respond to dust mineralogy. Finally we use AERONET data to evaluate model-based single scattering albedo. Acknowledgement We would like to thank the AERONET network and the principal investigators, as well as their staff, for establishing and maintaining the AERONET sites used in this work.

  9. A Novel Model Predictive Control for Single-Phase Grid-Connected Photovoltaic Inverters

    DEFF Research Database (Denmark)

    Zangeneh Bighash, Esmaeil; Sadeghzadeh, Seyed Mohammad; Ebrahimzadeh, Esmaeil

    2017-01-01

    Single-phase grid-connected inverters with LCL filter are widely used to connect photovoltaic systems to the utility grid. Among the existing control schemes, predictive control methods are faster and more accurate but also more complicated to implement. Recently, the Model Predictive Control (MPC......) algorithm for single-phase inverter has been presented, where the algorithm implementation is straightforward. In the MPC approach, all switching states are considered in each switching period to achieve the control objectives. However, since the number of switching states in single-phase inverters is small...... vectors. Simulation results show that the proposed approach lead to a lower THD in the injected current combined with fast dynamics. The proposed predictive control has been simulated and implemented on a 1 kW single-phase HERIC (highly efficient and reliable inverter concept) inverter with an LCL filter...

  10. Efficient use of single molecule time traces to resolve kinetic rates, models and uncertainties

    Science.gov (United States)

    Schmid, Sonja; Hugel, Thorsten

    2018-03-01

    Single molecule time traces reveal the time evolution of unsynchronized kinetic systems. Especially single molecule Förster resonance energy transfer (smFRET) provides access to enzymatically important time scales, combined with molecular distance resolution and minimal interference with the sample. Yet the kinetic analysis of smFRET time traces is complicated by experimental shortcomings—such as photo-bleaching and noise. Here we recapitulate the fundamental limits of single molecule fluorescence that render the classic, dwell-time based kinetic analysis unsuitable. In contrast, our Single Molecule Analysis of Complex Kinetic Sequences (SMACKS) considers every data point and combines the information of many short traces in one global kinetic rate model. We demonstrate the potential of SMACKS by resolving the small kinetic effects caused by different ionic strengths in the chaperone protein Hsp90. These results show an unexpected interrelation between conformational dynamics and ATPase activity in Hsp90.

  11. Substructure based modeling of nickel single crystals cycled at low plastic strain amplitudes

    Science.gov (United States)

    Zhou, Dong

    In this dissertation a meso-scale, substructure-based, composite single crystal model is fully developed from the simple uniaxial model to the 3-D finite element method (FEM) model with explicit substructures and further with substructure evolution parameters, to simulate the completely reversed, strain controlled, low plastic strain amplitude cyclic deformation of nickel single crystals. Rate-dependent viscoplasticity and Armstrong-Frederick type kinematic hardening rules are applied to substructures on slip systems in the model to describe the kinematic hardening behavior of crystals. Three explicit substructure components are assumed in the composite single crystal model, namely "loop patches" and "channels" which are aligned in parallel in a "vein matrix," and persistent slip bands (PSBs) connected in series with the vein matrix. A magnetic domain rotation model is presented to describe the reverse magnetostriction of single crystal nickel. Kinematic hardening parameters are obtained by fitting responses to experimental data in the uniaxial model, and the validity of uniaxial assumption is verified in the 3-D FEM model with explicit substructures. With information gathered from experiments, all control parameters in the model including hardening parameters, volume fraction of loop patches and PSBs, and variation of Young's modulus etc. are correlated to cumulative plastic strain and/or plastic strain amplitude; and the whole cyclic deformation history of single crystal nickel at low plastic strain amplitudes is simulated in the uniaxial model. Then these parameters are implanted in the 3-D FEM model to simulate the formation of PSB bands. A resolved shear stress criterion is set to trigger the formation of PSBs, and stress perturbation in the specimen is obtained by several elements assigned with PSB material properties a priori. Displacement increment, plastic strain amplitude control and overall stress-strain monitor and output are carried out in the user

  12. Navigation of guidewires and catheters in the body during intervention procedures : A review of computer-based models

    NARCIS (Netherlands)

    Sharei Amarghan, H.; Alderliesten, Tanja; van den Dobbelsteen, J.J.; Dankelman, J.

    2018-01-01

    Guidewires and catheters are used during minimally invasive interventional procedures to traverse in vascular system and access the desired position. Computer models are increasingly being used to predict the behavior of these instruments. This information can be used to choose the right

  13. A Policy Model for Use of Aversive and Deprivation Procedures to Decrease Problem Behaviors of Students in Special Education.

    Science.gov (United States)

    Braaten, Sheldon

    1991-01-01

    A draft policy developed by the Minneapolis (Minnesota) public schools concerning the use of aversive or deprivation procedures with students who are handicapped is presented. The policy model covers such elements as response to prior interventions; written treatment plan; informed consent; supervision; maintenance and retention of records;…

  14. The role of foot collateral vessels on ulcer healing and limb salvage after successful endovascular and surgical distal procedures according to an angiosome model.

    Science.gov (United States)

    Varela, César; Acín, Francisco; de Haro, Joaquín; Bleda, Silvia; Esparza, Leticia; March, José Ramón

    2010-11-01

    Analyze the influence of the collateral distal vessels on ischemic ulcer healing and limb salvage after successful distal procedures, according to an angiosome model. Retrospective analysis of 76 ischemic ulcers revascularized by surgical (n = 41) and endovascular (n = 35) distal procedures. All interventions were primary procedures with single outflow vessel that remained patent during follow-up. Ulcers were classified according to an angiography angiosome study as ''direct revascularization'' ([DR] n = 45), ''indirect revascularization'' ([IR] n = 31), and IR ''through collaterals'' ([IRc] n = 18). Healing rates and limb salvage were compared according to the type of revascularization. Ulcer healing rate at 12 months was higher in DR than in IR (92% vs 73%, P = .008) but similar to IRc (92% vs 85%). Limb salvage at 24 months was higher in DR than in IR (93% vs 72%, P = .02) but similar to IRc (93% vs 88%). Ulcer blood flow restoration through collateral vessels may give similar results to those obtained through its specific source artery.

  15. Obtaining manufactured geometries of deep-drawn components through a model updating procedure using geometric shape parameters

    Science.gov (United States)

    Balla, Vamsi Krishna; Coox, Laurens; Deckers, Elke; Plyumers, Bert; Desmet, Wim; Marudachalam, Kannan

    2018-01-01

    The vibration response of a component or system can be predicted using the finite element method after ensuring numerical models represent realistic behaviour of the actual system under study. One of the methods to build high-fidelity finite element models is through a model updating procedure. In this work, a novel model updating method of deep-drawn components is demonstrated. Since the component is manufactured with a high draw ratio, significant deviations in both profile and thickness distributions occurred in the manufacturing process. A conventional model updating, involving Young's modulus, density and damping ratios, does not lead to a satisfactory match between simulated and experimental results. Hence a new model updating process is proposed, where geometry shape variables are incorporated, by carrying out morphing of the finite element model. This morphing process imitates the changes that occurred during the deep drawing process. An optimization procedure that uses the Global Response Surface Method (GRSM) algorithm to maximize diagonal terms of the Modal Assurance Criterion (MAC) matrix is presented. This optimization results in a more accurate finite element model. The advantage of the proposed methodology is that the CAD surface of the updated finite element model can be readily obtained after optimization. This CAD model can be used for carrying out analysis, as it represents the manufactured part more accurately. Hence, simulations performed using this updated model with an accurate geometry, will therefore yield more reliable results.

  16. Modelling and analysis of transient state during improved coupling procedure with the grid for DFIG based wind turbine generator

    Science.gov (United States)

    Kammoun, Soulaymen; Sallem, Souhir; Ben Ali Kammoun, Mohamed

    2017-11-01

    The aim of this study is to enhance DFIG based Wind Energy Conversion Systems (WECS) dynamics during grid coupling. In this paper, a system modelling and a starting/coupling procedure for this generator to the grid are proposed. The proposed non-linear system is a variable structure system (VSS) and has two different states, before and after coupling. So, two different state models are given to the system to analyse transient stability during the coupling. The given model represents well the transient state of the machine, through which, a behaviour assessment of the generator before, during and after connection is given based on simulation results. For this, a 300 kW DFIG based wind generation system model was simulated on the Matlab/SIMULINK environment. We judge the proposed procedure to be practical, smooth and stability improved.

  17. NONLINEAR SYSTEM MODELING USING SINGLE NEURON CASCADED NEURAL NETWORK FOR REAL-TIME APPLICATIONS

    Directory of Open Access Journals (Sweden)

    S. Himavathi

    2012-04-01

    Full Text Available Neural Networks (NN have proved its efficacy for nonlinear system modeling. NN based controllers and estimators for nonlinear systems provide promising alternatives to the conventional counterpart. However, NN models have to meet the stringent requirements on execution time for its effective use in real time applications. This requires the NN model to be structurally compact and computationally less complex. In this paper a parametric method of analysis is adopted to determine the compact and faster NN model among various neural network architectures. This work proves through analysis and examples that the Single Neuron Cascaded (SNC architecture is distinct in providing compact and simpler models requiring lower execution time. The unique structural growth of SNC architecture enables automation in design. The SNC Network is shown to combine the advantages of both single and multilayer neural network architectures. Extensive analysis on selected architectures and their models for four benchmark nonlinear theoretical plants and a practical application are tested. A performance comparison of the NN models is presented to demonstrate the superiority of the single neuron cascaded architecture for online real time applications.

  18. Numerical model of spray combustion in a single cylinder diesel engine

    Science.gov (United States)

    Acampora, Luigi; Sequino, Luigi; Nigro, Giancarlo; Continillo, Gaetano; Vaglieco, Bianca Maria

    2017-11-01

    A numerical model is developed for predicting the pressure cycle from Intake Valve Closing (IVC) to the Exhaust Valve Opening (EVO) events. The model is based on a modified one-dimensional (1D) Musculus and Kattke spray model, coupled with a zero-dimensional (0D) non-adiabatic transient Fed-Batch reactor model. The 1D spray model provides an estimate of the fuel evaporation rate during the injection phenomenon, as a function of time. The 0D Fed-Batch reactor model describes combustion. The main goal of adopting a 0D (perfectly stirred) model is to use highly detailed reaction mechanisms for Diesel fuel combustion in air, while keeping the computational cost as low as possible. The proposed model is validated by comparing its predictions with experimental data of pressure obtained from an optical single cylinder Diesel engine.

  19. The development and evaluation of single cell suspension from wheat and barley as a model system; a first step towards functional genomics application

    DEFF Research Database (Denmark)

    Dong, Jing; Bowra, Steve; Vincze, Éva

    2010-01-01

    Background The overall research objective was to develop single cell plant cultures as a model system to facilitate functional genomics of monocots, in particular wheat and barley. The essential first step towards achieving the stated objective was the development of a robust, viable single cell...... suspension culture from both species. Results We established growth conditions to allow routine culturing of somatic cells in 24 well microtiter plate format. Evaluation of the wheat and barley cell suspension as model cell system is a multi step process. As an initial step in the evaluation procedure we...... level of genes (P5CS, P5CR) under various treatments and we suggest that the cells can be used as a model host system to study gene expression and regulation in monocots....

  20. Structural modeling of dahlia-type single-walled carbon nanohorn aggregates by molecular dynamics.

    Science.gov (United States)

    Hawelek, L; Brodka, A; Dore, John C; Hannon, Alex C; Iijima, S; Yudasaka, M; Ohba, T; Kaneko, K; Burian, A

    2013-09-19

    The structure of dahlia-type single-walled carbon nanohorn aggregates has been modeled by classical molecular dynamics simulations, and the validity of the model has been verified by neutron diffraction. Computer-generated models consisted of an outer part formed from single-walled carbon nanohorns with diameters of 20-50 Å and a length of 400 Å and an inner turbostratic graphite-like core with a diameter of 130 Å. The diffracted intensity and the pair correlation function computed for such a constructed model are in good agreement with the neutron diffraction experimental data. The proposed turbostratic inner core explains the occurrence of the additional (002) and (004) graphitic peaks in the diffraction pattern of the studied sample and provides information about the interior structure of the dahlia-type aggregates.

  1. Firefly Optimization and Mathematical Modeling of a Vehicle Crash Test Based on Single-Mass

    Directory of Open Access Journals (Sweden)

    Andreas Klausen

    2014-01-01

    Full Text Available In this paper mathematical modeling of a vehicle crash test based on a single-mass is studied. The model under consideration consists of a single-mass coupled with a spring and/or a damper. The parameters for the spring and damper are obtained by analyzing the measured acceleration in the center of gravity of the vehicle during a crash. A model with a nonlinear spring and damper is also proposed and the parameters will be optimized with different damper and spring characteristics and optimization algorithms. The optimization algorithms used are interior-point and firefly algorithm. The objective of this paper is to compare different methods used to establish a simple model of a car crash and validate the results against real crash data.

  2. DQ reference frame modeling and control of single-phase active power decoupling circuits

    DEFF Research Database (Denmark)

    Tang, Yi; Qin, Zian; Blaabjerg, Frede

    2015-01-01

    Power decoupling circuits can compensate the inherent double line frequency ripple power in single-phase systems and greatly facilitate their dc-link capacitor design. Example applications of power decoupling circuit include photovoltaic, light-emitting diode, fuel cell, and motor drive systems....... This paper presents the dq synchronous reference frame modeling of single-phase power decoupling circuits and a complete model describing the dynamics of dc-link ripple voltage is presented. The proposed model is universal and valid for both inductive and capacitive decoupling circuits, and the input...... of decoupling circuits can be either dependent or independent of its front-end converters. Based on this model, a dq synchronous reference frame controller is designed which allows the decoupling circuit to operate in two different modes because of the circuit symmetry. Simulation and experimental results...

  3. Single Channel Quantum Color Image Encryption Algorithm Based on HSI Model and Quantum Fourier Transform

    Science.gov (United States)

    Gong, Li-Hua; He, Xiang-Tao; Tan, Ru-Chao; Zhou, Zhi-Hong

    2018-01-01

    In order to obtain high-quality color images, it is important to keep the hue component unchanged while emphasize the intensity or saturation component. As a public color model, Hue-Saturation Intensity (HSI) model is commonly used in image processing. A new single channel quantum color image encryption algorithm based on HSI model and quantum Fourier transform (QFT) is investigated, where the color components of the original color image are converted to HSI and the logistic map is employed to diffuse the relationship of pixels in color components. Subsequently, quantum Fourier transform is exploited to fulfill the encryption. The cipher-text is a combination of a gray image and a phase matrix. Simulations and theoretical analyses demonstrate that the proposed single channel quantum color image encryption scheme based on the HSI model and quantum Fourier transform is secure and effective.

  4. Stress relaxation analysis of single chondrocytes using porohyperelastic model based on AFM experiments

    Directory of Open Access Journals (Sweden)

    Trung Dung Nguyen

    2014-01-01

    Full Text Available Based on atomic force microscopytechnique, we found that the chondrocytes exhibits stress relaxation behavior. We explored the mechanism of this stress relaxation behavior and concluded that the intracellular fluid exuding out from the cells during deformation plays the most important role in the stress relaxation. We applied the inverse finite element analysis technique to determine necessary material parameters for porohyperelastic (PHE model to simulate stress relaxation behavior as this model is proven capable of capturing the non-linear behavior and the fluid-solid interaction during the stress relaxation of the single chondrocytes. It is observed that PHE model can precisely capture the stress relaxation behavior of single chondrocytes and would be a suitable model for cell biomechanics.

  5. Testing of plain and fibrous concrete single cavity prestressed concrete reactor vessel models

    International Nuclear Information System (INIS)

    Oland, C.B.

    1985-01-01

    Two single-cavity prestressed concrete reactor vessel (PCRV) models were fabricated and tested to failure to demonstrate the structural response and ultimate pressure capacity of models cast from high-strength concretes. Concretes with design compressive strengths in excess of 70 MPa (10,000 psi) were developed for this investigation. One model was cast from plain concrete and failed in shear at the head region. The second model was cast from fiber reinforced concrete and failed by rupturing the circumferential prestressing at the sidewall of the structure. The tests also demonstrated the capabilities of the liner system to maintain a leak-tight pressure boundary. 3 refs., 4 figs

  6. Model for a collimated spin wave beam generated by a single layer, spin torque nanocontact

    OpenAIRE

    Hoefer, M. A.; Silva, T. J.; Stiles, M. D.

    2007-01-01

    A model of spin torque induced magnetization dynamics based upon semi-classical spin diffusion theory for a single layer nanocontact is presented. The model incorporates effects due to the current induced Oersted field and predicts the generation of a variety of spatially dependent, coherent, precessional magnetic wave structures. Directionally controllable collimated spin wave beams, vortex spiral waves, and localized standing waves are found to be excited by the interplay of the Oersted fie...

  7. Identification and estimation of nonseparable single-index models in panel data with correlated random effects

    NARCIS (Netherlands)

    Cizek, Pavel; Lei, Jinghua

    The identification in a nonseparable single-index models with correlated random effects is considered in panel data with a fixed number of time periods. The identification assumption is based on the correlated random effects structure. Under this assumption, the parameters of interest are identified

  8. Identification and Estimation of Nonseparable Single-Index Models in Panel Data with Correlated Random Effects

    NARCIS (Netherlands)

    Cizek, P.; Lei, J.

    2013-01-01

    Abstract: The identification of parameters in a nonseparable single-index models with correlated random effects is considered in the context of panel data with a fixed number of time periods. The identification assumption is based on the correlated random-effect structure: the distribution of

  9. Evaluating Change in Behavioral Preferences: Multidimensional Scaling Single-Ideal Point Model

    Science.gov (United States)

    Ding, Cody

    2016-01-01

    The purpose of the article is to propose a multidimensional scaling single-ideal point model as a method to evaluate changes in individuals' preferences under the explicit methodological framework of behavioral preference assessment. One example is used to illustrate the approach for a clear idea of what this approach can accomplish.

  10. Asymptotic normality of conditional distribution estimation in the single index model

    Directory of Open Access Journals (Sweden)

    Hamdaoui Diaa Eddine

    2017-08-01

    Full Text Available This paper deals with the estimation of conditional distribution function based on the single-index model. The asymptotic normality of the conditional distribution estimator is established. Moreover, as an application, the asymptotic (1 − γ confidence interval of the conditional distribution function is given for 0 < γ < 1.

  11. Asymptotic normality of conditional distribution estimation in the single index model

    OpenAIRE

    Hamdaoui Diaa Eddine; Bouchentouf Amina Angelika; Rabhi Abbes; Guendouzi Toufik

    2017-01-01

    This paper deals with the estimation of conditional distribution function based on the single-index model. The asymptotic normality of the conditional distribution estimator is established. Moreover, as an application, the asymptotic (1 − γ) confidence interval of the conditional distribution function is given for 0 < γ < 1.

  12. 76 FR 31453 - Special Conditions: Gulfstream Model GVI Airplane; Single-Occupant Side-Facing Seats

    Science.gov (United States)

    2011-06-01

    ... apply to that model as well. Conclusion This action affects only certain novel or unusual design... single-occupant side-facing seats: A. The Injury Criteria 1. Existing Criteria: All injury protection criteria of Sec. 25.562(c)(1) through (c)(6) apply to the occupant of a side-facing seat. Head injury...

  13. A Model-Free Diagnostic for Single-Peakedness of Item Responses Using Ordered Conditional Means

    Science.gov (United States)

    Polak, Marike; De Rooij, Mark; Heiser, Willem J.

    2012-01-01

    In this article we propose a model-free diagnostic for single-peakedness (unimodality) of item responses. Presuming a unidimensional unfolding scale and a given item ordering, we approximate item response functions of all items based on ordered conditional means (OCM). The proposed OCM methodology is based on Thurstone & Chave's (1929) "criterion…

  14. A single-system model predicts recognition memory and repetition priming in amnesia

    NARCIS (Netherlands)

    Berry, C.J.; Kessels, R.P.C.; Wester, A.J.; Shanks, D.R.

    2014-01-01

    We challenge the claim that there are distinct neural systems for explicit and implicit memory by demonstrating that a formal single-system model predicts the pattern of recognition memory (explicit) and repetition priming (implicit) in amnesia. In the current investigation, human participants with

  15. Equivalent circuit modeling and simulation of the zinc nickel single flow battery

    Directory of Open Access Journals (Sweden)

    Shouguang Yao

    2017-05-01

    Full Text Available This paper builds the equivalent circuit model for a single cell of zinc nickel single flow battery (ZNB with 300 Ah. According to the experimental data of the single cell under 100 A pulse discharge conditions, the model parameters can be obtained by parameter identification, and the analytical expressions for each model parameter can be obtained by using the method of high degree polynomial fitting and exponential function fitting, then the mathematical model of the stack voltage can be built. The relative error of the simulation results for stack voltage is controlled within 3.2% by experimental comparison, which verifies the accuracy of the model and model parameters. The parameter formulas obtained by fitting method can effectively solve calculation problem of the battery parameters. And under 100 A constant-current discharge condition, the stack voltage of the battery is dropping relatively flat over about 110 minutes after loading current, and dropping dramatically within about 50 minutes at the end of discharge due to the increasing polarization.

  16. 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.

  17. Synthesis and ultrastructure of plate-like apatite single crystals as a model for tooth enamel

    Energy Technology Data Exchange (ETDEWEB)

    Zhuang, Zhi, E-mail: zhuang@meiji.ac.jp [Department of Applied Chemistry, School of Science and Technology, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa 214-8571 (Japan); Yoshimura, Hideyuki, E-mail: hyoshi@isc.meiji.ac.jp [Department of Physics, School of Science and Technology, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa 214-8571 (Japan); Aizawa, Mamoru, E-mail: mamorua@isc.meiji.ac.jp [Department of Applied Chemistry, School of Science and Technology, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa 214-8571 (Japan)

    2013-07-01

    Hydroxyapatite (HAp) is an inorganic constituent compound of human bones and teeth, with superior biocompatibility and bioactivity characteristics. Its crystal structure is hexagonal, characterized by a(b)- and c-planes. In vertebrate long bones, HAp crystals have a c-axis orientation, while in tooth enamel, they have an a(b)-axis orientation. Many methods can be used to synthesize c-axis oriented HAp single crystals; however, to the best of our knowledge, there have been no reports on a synthesis method for a(b)-axis oriented HAp single crystals. In this study, we successfully synthesized plate-like HAp crystals at the air–liquid interface of a starting solution via an enzyme reaction of urea with urease. Crystal phase analysis and ultrastructure observations were carried out, and the results indicated that the particles were single crystals, with almost the same a(b)-axis orientation as tooth enamel. It is hoped that by utilizing their unique surface charge and atomic arrangement, the resulting particles can be used as a high-performance biomaterial, capable of adsorbing bio-related substances and a model for tooth enamel. - Highlights: ► Synthesis of plate-like hydroxyapatite crystals at air–liquid interface ► Ultrastructural analysis of plate-like hydroxyapatite crystals ► Plate-like hydroxyapatite single crystals with a high a(b)-axis orientation ► Plate-like hydroxyapatite single crystals as a model for tooth enamel.

  18. Using single cell sequencing data to model the evolutionary history of a tumor.

    Science.gov (United States)

    Kim, Kyung In; Simon, Richard

    2014-01-24

    The introduction of next-generation sequencing (NGS) technology has made it possible to detect genomic alterations within tumor cells on a large scale. However, most applications of NGS show the genetic content of mixtures of cells. Recently developed single cell sequencing technology can identify variation within a single cell. Characterization of multiple samples from a tumor using single cell sequencing can potentially provide information on the evolutionary history of that tumor. This may facilitate understanding how key mutations accumulate and evolve in lineages to form a heterogeneous tumor. We provide a computational method to infer an evolutionary mutation tree based on single cell sequencing data. Our approach differs from traditional phylogenetic tree approaches in that our mutation tree directly describes temporal order relationships among mutation sites. Our method also accommodates sequencing errors. Furthermore, we provide a method for estimating the proportion of time from the earliest mutation event of the sample to the most recent common ancestor of the sample of cells. Finally, we discuss current limitations on modeling with single cell sequencing data and possible improvements under those limitations. Inferring the temporal ordering of mutational sites using current single cell sequencing data is a challenge. Our proposed method may help elucidate relationships among key mutations and their role in tumor progression.

  19. Development of a single-layer Nb3Sn common coil dipole model

    Energy Technology Data Exchange (ETDEWEB)

    Igor Novitski et al.

    2002-12-13

    A high-field dipole magnet based on the common coil design was developed at Fermilab for a future Very Large Hadron Collider. A short model of this magnet with a design field of 11 T in two 40-mm apertures is being fabricated using the react-and-wind technique. In order to study and optimize the magnet design two 165-mm long mechanical models were assembled and tested. A technological model consisting of magnet straight section and ends was also fabricated in order to check the tooling and the winding and assembly procedures. This paper describes the design and technology of the common coil dipole magnet and summarizes the status of short model fabrication.The results of the mechanical model tests and comparison with FE mechanical analysis are also presented.

  20. An Introduction to the Model of Crisis Intervention Procedure for Borderline Patients (CIP-BP): A Case Study.

    Science.gov (United States)

    Koweszko, Tytus; Gierus, Jacek; Więdłocha, Magdalena; Mosiołek, Anna; Szulc, Agata

    2017-06-01

    Borderline personality disorder is highly associated with suicidal behaviors. The authors of the current case study present the introduction model of original Crisis Intervention Procedure for Borderline Patients (CIP-BP) which is a method focused on restoring emotional balance, reducing the severity of symptoms and the risk of suicidal behavior, as well as developing optimum solutions for further action. Its aim is to enable the patient to regain control of their emotional memory, increase autonomy and restore important interpersonal relations by using the original resources of this person. The procedure aims at providing nursing personnel with a practical tool to effectively avert the crisis and prevent further decompensation of BPD patients. Further pre-post study is required to determine the effectiveness of the procedure. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. A spectral geometric model for Compton single scatter in PET based on the single scatter simulation approximation

    DEFF Research Database (Denmark)

    Kazantsev, I.G.; Olsen, Ulrik Lund; Poulsen, Henning Friis

    2018-01-01

    scatter is interpreted as the volume integral over scatter points that constitute a rotation body with a football shape, while single scattering with a certain angle is evaluated as the surface integral over the boundary of the rotation body. The equations for total and sample single scatter calculations...... are derived using a single scatter simulation approximation. We show that the three-dimensional slice-by-slice filtered backprojection algorithm is applicable for scatter data inversion provided that the attenuation map is assumed to be constant. The results of the numerical experiments are presented....

  2. Exploring the boundary-layer cloud-climate feedback through Single-Column Model in Radiative-Advective Equilibrium

    Science.gov (United States)

    Dal Gesso, Sara; Neggers, Roel

    2017-04-01

    Boundary-layer clouds remain the major contributor to the inter-model spread in future climate predictions. Although light has been shed on the low-level cloud feedback, much remains to be understood about the physical mechanisms at the basis of the response of these clouds to climate warming. In the present study, EC-EARTH Single Column Model (SCM) is used to explore the boundary-layer cloud-climate feedback by imposing a Radiative-Advective Equilibrium, namely a balance between the radiative cooling and the advection of warm air. 30-year simulations are performed with the SCM forced by high-frequency cfSites outputs of the CMIP5 simulations of the host General Circulation Model (GCM) for both the AMIP and AMIP4K experiments. As this study exclusively focuses on marine low-level cloud regimes, the simulations are performed at the Barbados Cloud Observatory in the so-called "dry period", when the large-scale forcing are representative of subtropical marine trade-wind conditions. A first step is to assess how representative long-term SCM simulations are of their host GCM. Subsequently, the SCM is forced by different GCMs within the same framework. In this way, the contribution of the physical parameterization to the boundary-layer cloud feedback is isolated from the dynamics, and systematically evaluated. Finally, a procedure to integrate Large-Eddy Simulations and observations into this framework is discussed.

  3. Improved single particle potential for transport model simulations of nuclear reactions induced by rare isotope beams

    International Nuclear Information System (INIS)

    Xu Chang; Li Baoan

    2010-01-01

    Taking into account more accurately the isospin dependence of nucleon-nucleon interactions in the in-medium many-body force term of the Gogny effective interaction, new expressions for the single-nucleon potential and the symmetry energy are derived. Effects of both the spin (isospin) and the density dependence of nuclear effective interactions on the symmetry potential and the symmetry energy are examined. It is shown that they both play a crucial role in determining the symmetry potential and the symmetry energy at suprasaturation densities. The improved single-nucleon potential will be useful for more accurate simulation of nuclear reactions induced by rare-isotope beams within transport models.

  4. Monte Carlo Modelling of Single-Crystal Diffuse Scattering from Intermetallics

    Directory of Open Access Journals (Sweden)

    Darren J. Goossens

    2016-02-01

    Full Text Available Single-crystal diffuse scattering (SCDS reveals detailed structural insights into materials. In particular, it is sensitive to two-body correlations, whereas traditional Bragg peak-based methods are sensitive to single-body correlations. This means that diffuse scattering is sensitive to ordering that persists for just a few unit cells: nanoscale order, sometimes referred to as “local structure”, which is often crucial for understanding a material and its function. Metals and alloys were early candidates for SCDS studies because of the availability of large single crystals. While great progress has been made in areas like ab initio modelling and molecular dynamics, a place remains for Monte Carlo modelling of model crystals because of its ability to model very large systems; important when correlations are relatively long (though still finite in range. This paper briefly outlines, and gives examples of, some Monte Carlo methods appropriate for the modelling of SCDS from metallic compounds, and considers data collection as well as analysis. Even if the interest in the material is driven primarily by magnetism or transport behaviour, an understanding of the local structure can underpin such studies and give an indication of nanoscale inhomogeneity.

  5. A Control Volume Model of Solute Transport in a Single Fracture

    Science.gov (United States)

    Kennedy, Christopher A.; Lennox, William C.

    1995-02-01

    A control volume model of solute transport through a single fracture in a porous matrix is developed. Application to problems of contaminant transport through fractured clay demonstrates several strong features of the method. The control volume approach inherently conserves mass and treats dispersivity at interfaces in a physically correct manner. By employing an upstream weighting scheme, based on the exact solution to the one-dimensional steady state advection-dispersion equation, the model proves to be more efficient than previous single-fracture models. The significance of matrix diffusion in the direction parallel to the fracture axis is investigated. For the transport of a nonreactive tracer through a 20-micrometer-wide fracture in clay material, analytical solutions based on one-dimensional matrix diffusion are erroneous for flow velocities of less than 1 m/day. The influence of boundary conditions on two-dimensional matrix diffusion is considered, and the clean-up of a contaminated fracture is simulated.

  6. Application of Computer Program Carsim for Modelling Single and Double Lane Change Manoeuvres

    Directory of Open Access Journals (Sweden)

    Artūras Žukas

    2012-11-01

    Full Text Available The paper analyzes the possibilities of using computer aided modelling programs for developing new cars to achieve better dynamical properties of control over vehicles. The article shortly reviews the behaviour of young and experienced drivers and models describing it. The paper covers the process of turning car steering wheel, considers acceptable values of lateral acceleration comfortable for a car driver and all car passengers and presents computer aided modelling program CarSim used for displaying single and double lane change manoeuvres at various speeds on dry asphalt. The given charts, including data about steering wheel angle and lateral acceleration values indicate single and double lane change manoeuvres performed by a car. Also, the values of longitudinal and lateral forces of each wheel during the double lane change manoeuvre are provided.

  7. A stochastic model for magnetic dynamics in single-molecule magnets

    Energy Technology Data Exchange (ETDEWEB)

    López-Ruiz, R., E-mail: rlruiz@ifi.unicamp.br [Instituto de Física Gleb Wataghin - Universidade Estadual de Campinas, 13083-859 Campinas (SP) (Brazil); Almeida, P.T. [Instituto de Física Gleb Wataghin - Universidade Estadual de Campinas, 13083-859 Campinas (SP) (Brazil); Vaz, M.G.F. [Instituto de Química, Universidade Federal Fluminense, 24020-150 Niterói (RJ) (Brazil); Novak, M.A. [Instituto de Física - Universidade Federal do Rio de Janeiro, 21941-972 Rio de Janeiro (RJ) (Brazil); Béron, F.; Pirota, K.R. [Instituto de Física Gleb Wataghin - Universidade Estadual de Campinas, 13083-859 Campinas (SP) (Brazil)

    2016-04-01

    Hysteresis and magnetic relaxation curves were performed on double well potential systems with quantum tunneling possibility via stochastic simulations. Simulation results are compared with experimental ones using the Mn{sub 12} single-molecule magnet, allowing us to introduce time dependence in the model. Despite being a simple simulation model, it adequately reproduces the phenomenology of a thermally activated quantum tunneling and can be extended to other systems with different parameters. Assuming competition between the reversal modes, thermal (over) and tunneling (across) the anisotropy barrier, a separation of classical and quantum contributions to relaxation time can be obtained. - Highlights: • Single-molecule magnets are modeled using a simple stochastic approach. • Simulation reproduces thermally-activated tunnelling magnetization reversal features. • The time is introduced in hysteresis and relaxation simulations. • We can separate the quantum and classical contributions to decay time.

  8. Formal Uncertainty and Dispersion of Single and Double Difference Models for GNSS-Based Attitude Determination.

    Science.gov (United States)

    Chen, Wen; Yu, Chao; Dong, Danan; Cai, Miaomiao; Zhou, Feng; Wang, Zhiren; Zhang, Lei; Zheng, Zhengqi

    2017-02-20

    With multi-antenna synchronized global navigation satellite system (GNSS) receivers, the single difference (SD) between two antennas is able to eliminate both satellite and receiver clock error, thus it becomes necessary to reconsider the equivalency problem between the SD and double difference (DD) models. In this paper, we quantitatively compared the formal uncertainties and dispersions between multiple SD models and the DD model, and also carried out static and kinematic short baseline experiments. The theoretical and experimental results show that under a non-common clock scheme the SD and DD model are equivalent. Under a common clock scheme, if we estimate stochastic uncalibrated phase delay (UPD) parameters every epoch, this SD model is still equivalent to the DD model, but if we estimate only one UPD parameter for all epochs or take it as a known constant, the SD (here called SD2) and DD models are no longer equivalent. For the vertical component of baseline solutions, the formal uncertainties of the SD2 model are two times smaller than those of the DD model, and the dispersions of the SD2 model are even more than twice smaller than those of the DD model. In addition, to obtain baseline solutions, the SD2 model requires a minimum of three satellites, while the DD model requires a minimum of four satellites, which makes the SD2 more advantageous in attitude determination under sheltered environments.

  9. Predictive Models for the Free Energy of Hydrogen Bonded Complexes with Single and Cooperative Hydrogen Bonds.

    Science.gov (United States)

    Glavatskikh, Marta; Madzhidov, Timur; Solov'ev, Vitaly; Marcou, Gilles; Horvath, Dragos; Varnek, Alexandre

    2016-12-01

    In this work, we report QSPR modeling of the free energy ΔG of 1 : 1 hydrogen bond complexes of different H-bond acceptors and donors. The modeling was performed on a large and structurally diverse set of 3373 complexes featuring a single hydrogen bond, for which ΔG was measured at 298 K in CCl 4 . The models were prepared using Support Vector Machine and Multiple Linear Regression, with ISIDA fragment descriptors. The marked atoms strategy was applied at fragmentation stage, in order to capture the location of H-bond donor and acceptor centers. Different strategies of model validation have been suggested, including the targeted omission of individual H-bond acceptors and donors from the training set, in order to check whether the predictive ability of the model is not limited to the interpolation of H-bond strength between two already encountered partners. Successfully cross-validating individual models were combined into a consensus model, and challenged to predict external test sets of 629 and 12 complexes, in which donor and acceptor formed single and cooperative H-bonds, respectively. In all cases, SVM models outperform MLR. The SVM consensus model performs well both in 3-fold cross-validation (RMSE=1.50 kJ/mol), and on the external test sets containing complexes with single (RMSE=3.20 kJ/mol) and cooperative H-bonds (RMSE=1.63 kJ/mol). © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Protein secondary structure prediction for a single-sequence using hidden semi-Markov models

    Directory of Open Access Journals (Sweden)

    Borodovsky Mark

    2006-03-01

    Full Text Available Abstract Background The accuracy of protein secondary structure prediction has been improving steadily towards the 88% estimated theoretical limit. There are two types of prediction algorithms: Single-sequence prediction algorithms imply that information about other (homologous proteins is not available, while algorithms of the second type imply that information about homologous proteins is available, and use it intensively. The single-sequence algorithms could make an important contribution to studies of proteins with no detected homologs, however the accuracy of protein secondary structure prediction from a single-sequence is not as high as when the additional evolutionary information is present. Results In this paper, we further refine and extend the hidden semi-Markov model (HSMM initially considered in the BSPSS algorithm. We introduce an improved residue dependency model by considering the patterns of statistically significant amino acid correlation at structural segment borders. We also derive models that specialize on different sections of the dependency structure and incorporate them into HSMM. In addition, we implement an iterative training method to refine estimates of HSMM parameters. The three-state-per-residue accuracy and other accuracy measures of the new method, IPSSP, are shown to be comparable or better than ones for BSPSS as well as for PSIPRED, tested under the single-sequence condition. Conclusions We have shown that new dependency models and training methods bring further improvements to single-sequence protein secondary structure prediction. The results are obtained under cross-validation conditions using a dataset with no pair of sequences having significant sequence similarity. As new sequences are added to the database it is possible to augment the dependency structure and obtain even higher accuracy. Current and future advances should contribute to the improvement of function prediction for orphan proteins inscrutable

  11. Detection of Earthquake-Induced Damage in a Framed Structure Using a Finite Element Model Updating Procedure

    Science.gov (United States)

    Kim, Seung-Nam; Park, Taewon; Lee, Sang-Hyun

    2014-01-01

    Damage of a 5-story framed structure was identified from two types of measured data, which are frequency response functions (FRF) and natural frequencies, using a finite element (FE) model updating procedure. In this study, a procedure to determine the appropriate weightings for different groups of observations was proposed. In addition, a modified frame element which included rotational springs was used to construct the FE model for updating to represent concentrated damage at the member ends (a formulation for plastic hinges in framed structures subjected to strong earthquakes). The results of the model updating and subsequent damage detection when the rotational springs (RS model) were used were compared with those obtained using the conventional frame elements (FS model). Comparisons indicated that the RS model gave more accurate results than the FS model. That is, the errors in the natural frequencies of the updated models were smaller, and the identified damage showed clearer distinctions between damaged and undamaged members and was more consistent with observed damage. PMID:24574888

  12. Detection of Earthquake-Induced Damage in a Framed Structure Using a Finite Element Model Updating Procedure

    Directory of Open Access Journals (Sweden)

    Eunjong Yu

    2014-01-01

    Full Text Available Damage of a 5-story framed structure was identified from two types of measured data, which are frequency response functions (FRF and natural frequencies, using a finite element (FE model updating procedure. In this study, a procedure to determine the appropriate weightings for different groups of observations was proposed. In addition, a modified frame element which included rotational springs was used to construct the FE model for updating to represent concentrated damage at the member ends (a formulation for plastic hinges in framed structures subjected to strong earthquakes. The results of the model updating and subsequent damage detection when the rotational springs (RS model were used were compared with those obtained using the conventional frame elements (FS model. Comparisons indicated that the RS model gave more accurate results than the FS model. That is, the errors in the natural frequencies of the updated models were smaller, and the identified damage showed clearer distinctions between damaged and undamaged members and was more consistent with observed damage.

  13. Detection of earthquake-induced damage in a framed structure using a finite element model updating procedure.

    Science.gov (United States)

    Yu, Eunjong; Kim, Seung-Nam; Park, Taewon; Lee, Sang-Hyun

    2014-01-01

    Damage of a 5-story framed structure was identified from two types of measured data, which are frequency response functions (FRF) and natural frequencies, using a finite element (FE) model updating procedure. In this study, a procedure to determine the appropriate weightings for different groups of observations was proposed. In addition, a modified frame element which included rotational springs was used to construct the FE model for updating to represent concentrated damage at the member ends (a formulation for plastic hinges in framed structures subjected to strong earthquakes). The results of the model updating and subsequent damage detection when the rotational springs (RS model) were used were compared with those obtained using the conventional frame elements (FS model). Comparisons indicated that the RS model gave more accurate results than the FS model. That is, the errors in the natural frequencies of the updated models were smaller, and the identified damage showed clearer distinctions between damaged and undamaged members and was more consistent with observed damage.

  14. Modeling of the I V characteristics of single and double barrier tunneling diodes using A k · p band model

    Science.gov (United States)

    Mui, D.; Patil, M.; Chen, J.; Agarwala, S.; Kumar, N. S.; Morkoc, H.

    1989-11-01

    We model the I-V characteristics of single and double barrier tunneling diodes using the complex band structure of the tunneling barrier obtained from a k · p band model. Band-bending is calculated by solving two coupled 1-D Poisson's equations with a classical potential in the accumulation region. The transfer matrix method is used for the calculation of the transmission probability of the tunneling electron whose complex k-vector is obtained from the band structure. An energy dependent density of states effective mass which is also calculated from the band structure is used. I-V characteristics for In 0.53Ga 0.47As/In 0.52Al 0.48As/In 0.53Ga 0.47As single and double barrier tunneling diodes obtained from this model agree quantitatively with experiment.

  15. CT-QMC-simulations on the single impurity Anderson model with a superconducting bath

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, Florian; Pruschke, Thomas [Institut fuer theoretische Physik, Universitaet Goettingen, Friedrich-Hund-Platz 1, 37077 Goettingen (Germany)

    2016-07-01

    Coupling a heavy fermion impurity to a superconducting lead induces a competition between the Kondo effect and superconductivity in the low temperature regime. This situation has been modeled with a single impurity Anderson model, where the normal state bath is replaced by a BCS-type superconducting bath in mean field approximation. We study this model using a continuous-time quantum Monte Carlo hybridization expansion algorithm. Results include the impurity Green's functions as well as the corresponding spectral functions obtained from analytic continuation. Two side bands are observed which we discuss in the light of Yu-Shiba-Rusinov states.

  16. On Thermodynamics Problems in the Single-Phase-Lagging Heat Conduction Model

    Directory of Open Access Journals (Sweden)

    Shu-Nan Li

    2016-11-01

    Full Text Available Thermodynamics problems for the single-phase-lagging (SPL model have not been much studied. In this paper, the violation of the second law of thermodynamics by the SPL model is studied from two perspectives, which are the negative entropy production rate and breaking equilibrium spontaneously. The methods for the SPL model to avoid the negative entropy production rate are proposed, which are extended irreversible thermodynamics and the thermal relaxation time. Modifying the entropy production rate positive or zero is not enough to avoid the violation of the second law of thermodynamics for the SPL model, because the SPL model could cause breaking equilibrium spontaneously in some special circumstances. As comparison, it is shown that Fourier’s law and the CV model cannot break equilibrium spontaneously by analyzing mathematical energy integral.

  17. Simulating the 2012 High Plains Drought Using Three Single Column Models (SCM)

    Science.gov (United States)

    Medina, I. D.; Baker, I. T.; Denning, S.; Dazlich, D. A.

    2015-12-01

    The impact of changes in the frequency and severity of drought on fresh water sustainability is a great concern for many regions of the world. One such location is the High Plains, where the local economy is primarily driven by fresh water withdrawals from the Ogallala Aquifer, which accounts for approximately 30% of total irrigation withdrawals from all U.S. aquifers combined. Modeling studies that focus on the feedback mechanisms that control the climate and eco-hydrology during times of drought are limited, and have used conventional General Circulation Models (GCMs) with grid length scales ranging from one hundred to several hundred kilometers. Additionally, these models utilize crude statistical parameterizations of cloud processes for estimating sub-grid fluxes of heat and moisture and have a poor representation of land surface heterogeneity. For this research, we focus on the 2012 High Plains drought and perform numerical simulations using three single column model (SCM) versions of BUGS5 (Colorado State University (CSU) GCM coupled to the Simple Biosphere Model (SiB3)). In the first version of BUGS5, the model is used in its standard bulk setting (single atmospheric column coupled to a single instance of SiB3), secondly, the Super-Parameterized Community Atmospheric Model (SP-CAM), a cloud resolving model (CRM) (CRM consists of 32 atmospheric columns), replaces the single CSU GCM atmospheric parameterization and is coupled to a single instance of SiB3, and for the third version of BUGS5, an instance of SiB3 is coupled to each CRM column of the SP-CAM (32 CRM columns coupled to 32 instances of SiB3). To assess the physical realism of the land-atmosphere feedbacks simulated by all three versions of BUGS5, differences in simulated energy and moisture fluxes are computed between the 2011 and 2012 period and are compared to those calculated using observational data from the AmeriFlux Tower Network for the same period at the ARM Site in Lamont, OK. This research

  18. An Analysis of Bid Evaluation Procedures of Contemporary Models for Procurement in Pakistan

    Science.gov (United States)

    2016-12-01

    one company . In this procedure, contracting agency does not have to announce or advertise the procurement (Turkish Public Procurement Law , 2002...prosper them according to the related laws in Turkish public procurement system. This rule can only be used to support the local companies . There is...Commonwealth Procurement Rules. (2014). Public Procurement Law of Australia . Consult Australia . (2015). Economic benefits of better procurement

  19. Digital human modelling systems : A procedure for verification and validation using the F-16 crew station

    NARCIS (Netherlands)

    Hudson, J.A.; Oudenhuijzen, A.J.K.; Zehner, G.F.

    2000-01-01

    Mensmodellen worden veelal toegepast bij het ontwerpen en testen van werkplekken. Echter de nauwkeurigheid van de systemen is niet bekend. Er is dan een kans dat er (dure) fouten worden gemaakt. Om achter die nauwkeurigheid te komen is een procedure opgesteld om mensmodellen te testen

  20. Electromagnetically induced transparency and reduced speeds for single photons in a fully quantized model

    International Nuclear Information System (INIS)

    Purdy, Thomas; Ligare, Martin

    2003-01-01

    We introduce a simple model for electromagnetically induced transparency in which all fields are treated quantum mechanically. We study a system of three separated atoms at fixed positions in a one-dimensional multimode optical cavity. The first atom serves as the source for a single spontaneously emitted photon; the photon scatters from a three-level 'Λ'-configuration atom which interacts with an additional single-mode field coupling two of the atomic levels; the third atom serves as a detector of the total transmitted field. We find an analytical solution for the quantum dynamics. From the quantum amplitude describing the excitation of the detector atom we extract information that provides exact single-photon analogues to wave delays predicted by semi-classical theories. We also find complementary information in the expectation value of the electric field intensity operator

  1. Accounting for intracell flow in models with emphasis on water table recharge and stream-aquifer interaction: 2. A procedure

    Science.gov (United States)

    Jorgensen, Donald G.; Signor, Donald C.; Imes, Jeffrey L.

    1989-01-01

    Intercepted intracell flow, especially if cell includes water table recharge and a stream ((sink), can result in significant model error if not accounted for. A procedure utilizing net flow per cell (Fn) that accounts for intercepted intracell flow can be used for both steady state and transient simulations. Germane to the procedure is the determination of the ratio of area of influence of the interior sink to the area of the cell (Ai/Ac). Ai is the area in which water table recharge has the potential to be intercepted by the sink. Determining Ai/Ac requires either a detailed water table map or observation of stream conditions within the cell. A proportioning parameter M, which is equal to 1 or slightly less and is a function of cell geometry, is used to determine how much of the water that has potential for interception is intercepted by the sink within the cell. Also germane to the procedure is the determination of the flow across the streambed (Fs), which is not directly a function of cell size, due to difference in head between the water level in the stream and the potentiometric surface of the aquifer underlying the streambed. The use of Fn for steady state simulations allows simulation of water levels without utilizing head-dependent or constant head boundary conditions which tend to constrain the model-calculated water levels, an undesirable result if a comparison of measured and calculated water levels is being made. Transient simulations of streams usually utilize a head-dependent boundary condition and a leakance value to model a stream. Leakance values for each model cell can be determined from a steady state simulation, which used the net flow per cell procedure. For transient simulation, Fn would not include Fs. Also, for transient simulation it is necessary to check Fn at different time intervals because M and Ai/Ac are not constant and change with time. The procedure was used successfully in two different models of the aquifer system

  2. Peyton’s four-step approach: differential effects of single instructional steps on procedural and memory performance – a clarification study

    Directory of Open Access Journals (Sweden)

    Krautter M

    2015-05-01

    Full Text Available Markus Krautter,1 Ronja Dittrich,2 Annette Safi,2 Justine Krautter,1 Imad Maatouk,2 Andreas Moeltner,2 Wolfgang Herzog,2 Christoph Nikendei2 1Department of Nephrology, 2Department of General Internal and Psychosomatic Medicine, University of Heidelberg Medical Hospital, Heidelberg, Germany Background: Although Peyton’s four-step approach is a widely used method for skills-lab training in undergraduate medical education and has been shown to be more effective than standard instruction, it is unclear whether its superiority can be attributed to a specific single step. Purpose: We conducted a randomized controlled trial to investigate the differential learning outcomes of the separate steps of Peyton’s four-step approach. Methods: Volunteer medical students were randomly assigned to four different groups. Step-1 group received Peyton’s Step 1, Step-2 group received Peyton’s Steps 1 and 2, Step-3 group received Peyton’s Steps 1, 2, and 3, and Step-3mod group received Peyton’s Steps 1 and 2, followed by a repetition of Step 2. Following the training, the first independent performance of a central venous catheter (CVC insertion using a manikin was video-recorded and scored by independent video assessors using binary checklists. The day after the training, memory performance during delayed recall was assessed with an incidental free recall test. Results: A total of 97 participants agreed to participate in the trial. There were no statistically significant group differences with regard to age, sex, completed education in a medical profession, completed medical clerkships, preliminary memory tests, or self-efficacy ratings. Regarding checklist ratings, Step-2 group showed a superior first independent performance of CVC placement compared to Step-1 group (P<0.001, and Step-3 group showed a superior performance to Step-2 group (P<0.009, while Step-2 group and Step-3mod group did not differ (P=0.055. The findings were similar in the incidental

  3. Characterization of biomass combustion at high temperatures based on an upgraded single particle model

    International Nuclear Information System (INIS)

    Li, Jun; Paul, Manosh C.; Younger, Paul L.; Watson, Ian; Hossain, Mamdud; Welch, Stephen

    2015-01-01

    Highlights: • High temperature rapid biomass combustion is studied based on single particle model. • Particle size changes in devolatilization and char oxidation models are addressed. • Time scales of various thermal sub-processes are compared and discussed. • Potential solutions are suggested to achieve better biomass co-firing performances. - Abstract: Biomass co-firing is becoming a promising solution to reduce CO 2 emissions, due to its renewability and carbon neutrality. Biomass normally has high moisture and volatile contents, complicating its combustion behavior, which is significantly different from that of coal. A computational fluid dynamics (CFD) combustion model of a single biomass particle is employed to study high-temperature rapid biomass combustion. The two-competing-rate model and kinetics/diffusion model are used to model biomass devolatilization reaction and char burnout process, respectively, in which the apparent kinetics used for those two models were from high temperatures and high heating rates tests. The particle size changes during the devolatilization and char burnout are also considered. The mass loss properties and temperature profile during the biomass devolatilization and combustion processes are predicted; and the timescales of particle heating up, drying, devolatilization, and char burnout are compared and discussed. Finally, the results shed light on the effects of particle size on the combustion behavior of biomass particle

  4. A single-equation study of US petroleum consumption: The role of model specificiation

    International Nuclear Information System (INIS)

    Jones, C.T.

    1993-01-01

    The price responsiveness of US petroleum consumption began to attract a great deal of attention following the unexpected and substantial oil price increases of 1973-74. There have been a number of large, multi-equation econometric studies of US energy demand since then which have focused primarily on estimating short run and long run price and income elasticities of individual energy resources (coal, oil, natural gas ampersand electricity) for various consumer sectors (residential, industrial, commercial). Following these early multi-equation studies there have been several single-equation studies of aggregate US petroleum consumption. When choosing an economic model specification for a single-equation study of aggregate US petroleum consumption, an easily estimated model that will provide unbiased price and income elasticity estimates and yield accurate forecasts is needed. Using Hendry's general-to-simple specification search technique and annual data to obtain a restricted, data-acceptable simplification of a general ADL model yielded GNP and short run price elasticities near the consensus estimates, but a long run price elasticity substantially smaller than existing estimates. Comparisons with three other seemingly acceptable simple-to-general models showed that popular model specifications often involve untested, unacceptable parameter restrictions. These models may also demonstrate poorer forecasting performance. Based on results, the general-to-simple approach appears to offer a more accurate methodology for generating superior forecast models of petroleum consumption and other energy use patterns

  5. Rainfall effect on single-vehicle crash severities using polychotomous response models.

    Science.gov (United States)

    Jung, Soyoung; Qin, Xiao; Noyce, David A

    2010-01-01

    As part of the Wisconsin road weather safety initiative, the objective of this study is to assess the effects of rainfall on the severity of single-vehicle crashes on Wisconsin interstate highways utilizing polychotomous response models. Weather-related factors considered in this study include estimated rainfall intensity for 15 min prior to a crash occurrence, water film depth, temperature, wind speed/direction, stopping sight distance and deficiency of car-following distance at the crash moment. For locations with unknown weather information, data were interpolated using the inverse squared distance method. Non-weather factors such as road geometrics, traffic conditions, collision types, vehicle types, and driver and temporal attributes were also considered. Two types of polychotomous response models were compared: ordinal logistic and sequential logistic regressions. The sequential logistic regression was tested with forward and backward formats. Comparative models were also developed for single vehicle crash severity during clear weather. In conclusion, the backward sequential logistic regression model produced the best results for predicting crash severities in rainy weather where rainfall intensity, wind speed, roadway terrain, driver's gender, and safety belt were found to be statistically significant. Our study also found that the seasonal factor was significant in clear weather. The seasonal factor is a predictor suggesting that inclement weather may affect crash severity. These findings can be used to determine the probabilities of single vehicle crash severity in rainy weather and provide quantitative support on improving road weather safety via weather warning systems, highway facility improvements, and speed limit management.

  6. Protein structural model selection by combining consensus and single scoring methods.

    Directory of Open Access Journals (Sweden)

    Zhiquan He

    Full Text Available Quality assessment (QA for predicted protein structural models is an important and challenging research problem in protein structure prediction. Consensus Global Distance Test (CGDT methods assess each decoy (predicted structural model based on its structural similarity to all others in a decoy set and has been proved to work well when good decoys are in a majority cluster. Scoring functions evaluate each single decoy based on its structural properties. Both methods have their merits and limitations. In this paper, we present a novel method called PWCom, which consists of two neural networks sequentially to combine CGDT and single model scoring methods such as RW, DDFire and OPUS-Ca. Specifically, for every pair of decoys, the difference of the corresponding feature vectors is input to the first neural network which enables one to predict whether the decoy-pair are significantly different in terms of their GDT scores to the native. If yes, the second neural network is used to decide which one of the two is closer to the native structure. The quality score for each decoy in the pool is based on the number of winning times during the pairwise comparisons. Test results on three benchmark datasets from different model generation methods showed that PWCom significantly improves over consensus GDT and single scoring methods. The QA server (MUFOLD-Server applying this method in CASP 10 QA category was ranked the second place in terms of Pearson and Spearman correlation performance.

  7. Substitutional impurity in single-layer graphene: The Koster–Slater and Anderson models

    Energy Technology Data Exchange (ETDEWEB)

    Davydov, S. Yu., E-mail: sergei-davydov@mail.ru [Russian Academy of Sciences, Ioffe Physical–Technical Institute (Russian Federation)

    2016-06-15

    The Koster–Slater and Anderson models are used to consider substitutional impurities in free-standing single-layer graphene. The density of states of graphene is described using a model (the M model). For the nitrogen and boron impurities, the occupation numbers and the parameter η which defines the fraction of delocalized electrons of the impurity are determined. In this case, experimental data are used for both determination of the model parameters and comparison with the results of theoretical estimations. The general features of the Koster–Slater and Anderson models and the differences between the two models are discussed. Specifically, it is shown that the band contributions to the occupation numbers of a nitrogen atom in both models are comparable, whereas the local contributions are substantially different: the local contributions are decisive in the Koster–Slater model and negligible in the Anderson model. The asymptotic behavior of the wave functions of a defect is considered in the Koster–Slater model, and the electron states of impurity dimers are considered in the Anderson model.

  8. Deconstructing stem cell population heterogeneity: Single-cell analysis and modeling approaches

    Science.gov (United States)

    Wu, Jincheng; Tzanakakis, Emmanuel S.

    2014-01-01

    Isogenic stem cell populations display cell-to-cell variations in a multitude of attributes including gene or protein expression, epigenetic state, morphology, proliferation and proclivity for differentiation. The origins of the observed heterogeneity and its roles in the maintenance of pluripotency and the lineage specification of stem cells remain unclear. Addressing pertinent questions will require the employment of single-cell analysis methods as traditional cell biochemical and biomolecular assays yield mostly population-average data. In addition to time-lapse microscopy and flow cytometry, recent advances in single-cell genomic, transcriptomic and proteomic profiling are reviewed. The application of multiple displacement amplification, next generation sequencing, mass cytometry and spectrometry to stem cell systems is expected to provide a wealth of information affording unprecedented levels of multiparametric characterization of cell ensembles under defined conditions promoting pluripotency or commitment. Establishing connections between single-cell analysis information and the observed phenotypes will also require suitable mathematical models. Stem cell self-renewal and differentiation are orchestrated by the coordinated regulation of subcellular, intercellular and niche-wide processes spanning multiple time scales. Here, we discuss different modeling approaches and challenges arising from their application to stem cell populations. Integrating single-cell analysis with computational methods will fill gaps in our knowledge about the functions of heterogeneity in stem cell physiology. This combination will also aid the rational design of efficient differentiation and reprogramming strategies as well as bioprocesses for the production of clinically valuable stem cell derivatives. PMID:24035899

  9. Collective noise model for focal plane modulated single-pixel imaging

    Science.gov (United States)

    Sun, Ming-Jie; Xu, Zi-Hao; Wu, Ling-An

    2018-01-01

    Single-pixel imaging, also known as computational ghost imaging, provides an alternative method to perform imaging in various applications which are difficult for conventional cameras with pixelated detectors, such as multi-wavelength imaging, three-dimensional imaging, and imaging through turbulence. In recent years, many improvements have successfully increased the signal-to-noise ratio of single-pixel imaging systems, showing promise for the engineering feasibility of this technique. However, many of these improvements are based on empirical findings. In this work we perform an investigation of the noise from each system component that affects the quality of the reconstructed image in a single-pixel imaging system based on focal plane modulation. A collective noise model is built to describe the resultant influence of these different noise sources, and numerical simulations are performed to quantify the effect. Experiments have been conducted to verify the model, and the results agree well with the simulations. This work provides a simple yet accurate method for evaluating the performance of a single-pixel imaging system, without having to carry out actual experimental tests.

  10. Single-phase sodium pump model for LMFBR thermal-hydraulic analysis

    International Nuclear Information System (INIS)

    Madni, I.K.; Cazzoli, E.G.; Agrawal, A.K.

    1979-01-01

    A single-phase, homologous pump model has been developed for simulation of safety-related transients in LMFBR systems. Pump characteristics are modeled by homologous head and torque relations encompassing all regimes of operation. These relations were derived from independent model test results with a centrifugal pump of specific speed equal to 35 (SI units) or 1800 (gpm units), and are used to analyze the steady-state and transient behavior of sodium pumps in a number of LMFBR plants. Characteristic coefficients for the polynomials in all operational regimes are provided in a tabular form. The speed and flow dependence of head is included through solutions of the impeller and coolant dynamic equations. Results show the model to yield excellent agreement with experimental data in sodium for the FFTF prototype pump, and with vendor calculations for the CRBR pump. A sample pipe rupture calculation is also performed to demonstrate the necessity for modeling the complete pump characteristics

  11. Synthesis of 3D Model of a Magnetic Field-Influenced Body from a Single Image

    Science.gov (United States)

    Wang, Cuilan; Newman, Timothy; Gallagher, Dennis

    2006-01-01

    A method for recovery of a 3D model of a cloud-like structure that is in motion and deforming but approximately governed by magnetic field properties is described. The method allows recovery of the model from a single intensity image in which the structure's silhouette can be observed. The method exploits envelope theory and a magnetic field model. Given one intensity image and the segmented silhouette in the image, the method proceeds without human intervention to produce the 3D model. In addition to allowing 3D model synthesis, the method's capability to yield a very compact description offers further utility. Application of the method to several real-world images is demonstrated.

  12. POD-Galerkin Model for Incompressible Single-Phase Flow in Porous Media

    KAUST Repository

    Wang, Yi

    2017-01-25

    Fast prediction modeling via proper orthogonal decomposition method combined with Galerkin projection is applied to incompressible single-phase fluid flow in porous media. Cases for different configurations of porous media, boundary conditions and problem scales are designed to examine the fidelity and robustness of the model. High precision (relative deviation 1.0 x 10(-4)% similar to 2.3 x 10(-1)%) and large acceleration (speed-up 880 similar to 98454 times) of POD model are found in these cases. Moreover, the computational time of POD model is quite insensitive to the complexity of problems. These results indicate POD model is especially suitable for large-scale complex problems in engineering.

  13. A compact model for single material double work function gate MOSFET

    Science.gov (United States)

    Changyong, Zheng; Wei, Zhang; Tailong, Xu; Yuehua, Dai; Junning, Chen

    2013-09-01

    An analytical surface potential model for the single material double work function gate (SMDWG) MOSFET is developed based on the exact resultant solution of the two-dimensional Poisson equation. The model includes the effects of drain biases, gate oxide thickness, different combinations of S-gate and D-gate length and values of substrate doping concentration. More attention has been paid to seeking to explain the attributes of the SMDWG MOSFET, such as suppressing drain-induced barrier lowering (DIBL), accelerating carrier drift velocity and device speed. The model is verified by comparison to the simulated results using the device simulator MEDICI. The accuracy of the results obtained using our analytical model is verified using numerical simulations. The model not only offers the physical insight into device physics but also provides the basic designing guideline for the device.

  14. Thermal vibration of rectangular single-layered black phosphorus predicted by orthotropic plate model

    Science.gov (United States)

    Zhang, Yiqing; Wang, Lifeng; Jiang, Jingnong

    2018-03-01

    Vibrational behavior is very important for nanostructure-based resonators. In this work, an orthotropic plate model together with a molecular dynamics (MD) simulation is used to investigate the thermal vibration of rectangular single-layered black phosphorus (SLBP). Two bending stiffness, two Poisson's ratios, and one shear modulus of SLBP are calculated using the MD simulation. The natural frequency of the SLBP predicted by the orthotropic plate model agrees with the one obtained from the MD simulation very well. The root of mean squared (RMS) amplitude of the SLBP is obtained by MD simulation and the orthotropic plate model considering the law of energy equipartition. The RMS amplitude of the thermal vibration of the SLBP is predicted well by the orthotropic plate model compared to the MD results. Furthermore, the thermal vibration of the SLBP with an initial stress is also well-described by the orthotropic plate model.

  15. A mathematical model for order splitting in a multiple supplier single-item inventory system

    DEFF Research Database (Denmark)

    Abginehchi, Soheil; Farahani, Reza Zanjirani; Rezapour, Shabnam

    2013-01-01

    The policy of simultaneously splitting replenishment orders among several suppliers has received considerable attention in the last few years and continues to attract the attention of researchers. In this paper, we develop a mathematical model which considers multiple-supplier single-item inventory...... systems. The item acquisition lead times of suppliers are random variables. Backorder is allowed and shortage cost is charged based on not only per unit in shortage but also per time unit. Continuous review (s,Q) policy has been assumed. When the inventory level depletes to a reorder level, the total......, procurement cost, inventory holding cost, and shortage cost, is minimized. We also conduct extensive numerical experiments to show the advantages of our model compared with the models in the literature. According to our extensive experiments, the model developed in this paper is the best model...

  16. Robot-assisted laparoscopic transperitoneal infrarenal lymphadenectomy in patients with locally advanced cervical cancer by single docking: Do we need a backup procedure?

    Science.gov (United States)

    Gucer, Fatih; Misirlioglu, Selim; Ceydeli, Nuri; Taskiran, Cagatay

    2018-03-01

    To present our initial experience on the feasibility of robotic transperitoneal para-aortic lymphadenectomy up to left renal vein via single docking approach by high port insertion technique followed by left shoulder docking as a rescue backup procedure in surgically obstructed patients undergoing surgical staging because of locally advanced cervical cancer (LACC). Prospective observational preliminary study. Canadian Task Force classification II-3. Tertiary-care academic affiliated private hospital. Ten patients with LACC who underwent robotic transperitoneal infrarenal para-aortic lymphadenectomy between January 2012 and December 2014. All patients with pathologically proven cervical cancer underwent a PET/CT scanning in a similar fashion at the department of nuclear medicine. PET/CT scans were evaluated by the nuclear medicine specialist. Following pre-operative work-up, robot-assisted transperitoneal infrarenal para-aortic lymphadenectomy was performed up to left renal vein by the same experienced surgeon. Sections of 5 mm were performed and stained with routine hematoxylin and eosin (H&E), and node count was done separately by experienced gynecopathologist. During the study period, 12 consecutive patients with LACC were counseled for pre-therapeutic robot-assisted transperitoneal para-aortic lymphadenectomy. Two patients declined the procedure and underwent standardized chemo-radiation therapy whereas remaining ten patients constituted the study group. In the study group, the median age was 46 years (range 33-59 years), and the median body mass index 28.5 kg/m 2 (range 18.5-35.1 kg/m 2 ). Clinical staging was stage IIB in four patients, IIIB in four, and IVA in one. Histopathological diagnosis was squamous cell carcinoma in nine patients, and adenocarcinoma in one. On PET/CT scans, seven out of ten patients were positive for pelvic lymph node metastasis. With respect to para-aortic area, only one of the ten patients had suspected metastasis in PET/CT. For

  17. Conceptual model and procedures to assimilate production technologies of bioenergetics of residual biomass

    International Nuclear Information System (INIS)

    Muto Lubota, David; González Suárez, Erenio; Hernández Pérez, Gilberto; Miño Valdés, Juan Esteban

    2016-01-01

    The present work expose the conceptual pattern for a process of assimilation of technologies with the purpose of creating obtaining capacities of bio energy with the objective of achieving an energy insurance of the recycle of Urban Solid Residuals (RSU) in the municipality of Cabinda, Angola. The conceptual pattern is novel because it considers the south-south collaboration, and it is supported by a general procedure of assimilation of the technologies that includes in one of its steps a specify procedure for the step concerning the insurance of the chain supply that contains as additional aspect, in a novel way, the determination of the initial’s investors capacities assisting to the demand of final products as well as to the readiness of the raw materials, based in the problems of uncertainty to the future changes. Finally conclusions are elaborated with projections for the future work. (author)

  18. ASSESSING GOING CONCERN ASSUMPTION BY USING RATING VALUATION MODELS BASED UPON ANALYTICAL PROCEDURES IN CASE OF FINANCIAL INVESTMENT COMPANIES

    OpenAIRE

    Tatiana Danescu; Ovidiu Spatacean; Paula Nistor; Andrea Cristina Danescu

    2010-01-01

    Designing and performing analytical procedures aimed to assess the rating of theFinancial Investment Companies are essential activities both in the phase of planning a financialaudit mission and in the phase of issuing conclusions regarding the suitability of using by themanagement and other persons responsible for governance of going concern, as the basis forpreparation and disclosure of financial statements. The paper aims to examine the usefulness ofrecognized models used in the practice o...

  19. A Single Column Model Ensemble Approach Applied to the TWP-ICE Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Davies, Laura; Jakob, Christian; Cheung, K.; Del Genio, Anthony D.; Hill, Adrian; Hume, Timothy; Keane, R. J.; Komori, T.; Larson, Vincent E.; Lin, Yanluan; Liu, Xiaohong; Nielsen, Brandon J.; Petch, Jon C.; Plant, R. S.; Singh, M. S.; Shi, Xiangjun; Song, X.; Wang, Weiguo; Whitall, M. A.; Wolf, A.; Xie, Shaocheng; Zhang, Guang J.

    2013-06-27

    Single column models (SCM) are useful testbeds for investigating the parameterisation schemes of numerical weather prediction and climate models. The usefulness of SCM simulations are limited, however, by the accuracy of the best-estimate large-scale data prescribed. One method to address this uncertainty is to perform ensemble simulations of the SCM. This study first derives an ensemble of large-scale data for the Tropical Warm Pool International Cloud Experiment (TWP-ICE) based on an estimate of a possible source of error in the best-estimate product. This data is then used to carry out simulations with 11 SCM and 2 cloud-resolving models (CRM). Best-estimate simulations are also performed. All models show that moisture related variables are close to observations and there are limited differences between the best-estimate and ensemble mean values. The models, however, show different sensitivities to changes in the forcing particularly when weakly forced. The ensemble simulations highlight important differences in the moisture budget between the SCM and CRM. Systematic differences are also apparent in the ensemble mean vertical structure of cloud variables. The ensemble is further used to investigate relations between cloud variables and precipitation identifying large differences between CRM and SCM. This study highlights that additional information can be gained by performing ensemble simulations enhancing the information derived from models using the more traditional single best-estimate simulation.

  20. Semantic Modeling of Administrative Procedures from a Spanish Regional Public Administration

    OpenAIRE

    Francisco José Hidalgo López; Jose Emilio Labra Gayo; Patricia Ordóñez de Pablos

    2018-01-01

    Over the past few years, Public Administrations have been providing systems for procedures and files electronic processing to ensure compliance with regulations and provide public services to citizens. Although each administration provides similar services to their citizens, these systems usually differ from the internal information management point of view since they usually come from different products and manufacturers. The common framework that regulations demand, and that Public Administ...