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Sample records for modeling approaches involving

  1. Inquiry Role Approach: A Model for Counselor Involvement in Learning.

    Science.gov (United States)

    Bingman, Richard M.; And Others

    The Inquiry Role Approach (IRA) is a strategy for classroom learning in which students work as 4-member teams and assume roles as Team Coordinator, Process Advisor, Data Recorder, and Technical Advisor. Cognitive as well as affective objectives are identified which relate to optimum learning and personal growth in the classroom. The counselor's…

  2. Dispersion modelling approaches for near road applications involving noise barriers

    Science.gov (United States)

    The talk will present comparisons with two datasets of the barrier algorithms implemented in two different dispersion models: US EPA’s R-LINE (a research dispersion modelling tool under development by the US EPA’s Office of Research and Development) and CERC’s A...

  3. System Model Bias Processing Approach for Regional Coordinated States Information Involved Filtering

    Directory of Open Access Journals (Sweden)

    Zebo Zhou

    2016-01-01

    Full Text Available In the Kalman filtering applications, the conventional dynamic model which connects the states information of two consecutive epochs by state transition matrix is usually predefined and assumed to be invariant. Aiming to improve the adaptability and accuracy of dynamic model, we propose multiple historical states involved filtering algorithm. An autoregressive model is used as the dynamic model which is subsequently combined with observation model for deriving the optimal window-recursive filter formulae in the sense of minimum mean square error principle. The corresponding test statistics characteristics of system residuals are discussed in details. The test statistics of regional predicted residuals are then constructed in a time-window for model bias testing with two hypotheses, that is, the null and alternative hypotheses. Based on the innovations test statistics, we develop a model bias processing procedure including bias detection, location identification, and state correction. Finally, the minimum detectable bias and bias-to-noise ratio are both computed for evaluating the internal and external reliability of overall system, respectively.

  4. A model approach to vanadium involvement in crude oils and their refining. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Christou, G.

    1994-04-01

    Heavy crude oils contain a large amount of metal impurities, primarily vanadium species. These comprise both vanadyl porphyrins and vanadyl non-porphyrins. During hydrotreating of crude oils (reaction with H{sub 2} over a supported Mo/S catalyst at 350-- 450{degrees}C) for upgrading to usable products the V impurities are converted to insoluble V sulfides which help poison the fixed-bed Mo catalyst. Very little is known about the chemistry occurring at a detailed level; basically, it is known that initial impurities are vanadyl (VO){sup 2+}, i.e., V{sup IV} species, and that during the refining processes they are reduced and sulfided into polymers, i.e., the metal is reduced from V{sup IV} to {approximately} V{sup III}, the oxo is lost, the organic ligation is lost, and the metal is sulfided. In what order and in precisely what manner this overall transformation is occurring is not known. The essence of our research efforts is to develop vanadium chemistry of relevance to this area and to thereby provide fundamental information on the transformations occurring and that might prove useful in catalyst design. Our work has encompassed the study of the reactivity chemistry of [VO]{sup 2+} species and the formation and characterization of V/S aggregates under conditions designed to mimic those present under hydrotreating conditions. Thus, we are applying an Inorganic Model Approach to provide insights into the chemistry occurring during the refining process. Our emphasis has been on definitive characterization of products using a variety of physical techniques,including X-ray crystallography. Our work covers the following areas, each of which is described: studies in V/O{sup 2+} chemistry; V{sup III}/O chemistry; V/S complexes; and absorption of [VO]{sup 2+} groups on catalyst surfaces.

  5. A Blended Learning Approach to Teaching Project Management: A Model for Active Participation and Involvement: Insights from Norway

    Directory of Open Access Journals (Sweden)

    Bassam A. Hussein

    2015-04-01

    Full Text Available The paper demonstrates and evaluates the effectiveness of a blended learning approach to create a meaningful learning environment. We use the term blended learning approach in this paper to refer to the use of multiple or hybrid instructional methods that emphasize the role of learners as contributors to the learning process rather than recipients of learning. Contribution to learning is attained by using in class gaming as pathways that ensure active involvement of learners. Using a blended learning approach is important in order to be able to address different learning styles of the target group. The approach was also important in order to be able to demonstrate different types of challenges, issues and competences needed in project management. Student evaluations of the course confirmed that the use of multiple learning methods and, in particular, in class gaming was beneficial and contributed to a meaningful learning experience.

  6. A Blended Learning Approach to Teaching Project Management: A Model for Active Participation and Involvement--Insights from Norway

    Science.gov (United States)

    Hussein, Bassam A.

    2015-01-01

    The paper demonstrates and evaluates the effectiveness of a blended learning approach to create a meaningful learning environment. We use the term blended learning approach in this paper to refer to the use of multiple or hybrid instructional methods that emphasize the role of learners as contributors to the learning process rather than recipients…

  7. A Self-Instructional Approach To the Teaching of Enzymology Involving Computer-Based Sequence Analysis and Molecular Modelling.

    Science.gov (United States)

    Attwood, Paul V.

    1997-01-01

    Describes a self-instructional assignment approach to the teaching of advanced enzymology. Presents an assignment that offers a means of teaching enzymology to students that exposes them to modern computer-based techniques of analyzing protein structure and relates structure to enzyme function. (JRH)

  8. Involving students in experimental design: three approaches.

    Science.gov (United States)

    McNeal, A P; Silverthorn, D U; Stratton, D B

    1998-12-01

    Many faculty want to involve students more actively in laboratories and in experimental design. However, just "turning them loose in the lab" is time-consuming and can be frustrating for both students and faculty. We describe three different ways of providing structures for labs that require students to design their own experiments but guide the choices. One approach emphasizes invertebrate preparations and classic techniques that students can learn fairly easily. Students must read relevant primary literature and learn each technique in one week, and then design and carry out their own experiments in the next week. Another approach provides a "design framework" for the experiments so that all students are using the same technique and the same statistical comparisons, whereas their experimental questions differ widely. The third approach involves assigning the questions or problems but challenging students to design good protocols to answer these questions. In each case, there is a mixture of structure and freedom that works for the level of the students, the resources available, and our particular aims.

  9. Heterogeneity in the Relationship of Substance Use to Risky Sexual Behavior Among Justice-Involved Youth: A Regression Mixture Modeling Approach.

    Science.gov (United States)

    Schmiege, Sarah J; Bryan, Angela D

    2016-04-01

    Justice-involved adolescents engage in high levels of risky sexual behavior and substance use, and understanding potential relationships among these constructs is important for effective HIV/STI prevention. A regression mixture modeling approach was used to determine whether subgroups could be identified based on the regression of two indicators of sexual risk (condom use and frequency of intercourse) on three measures of substance use (alcohol, marijuana and hard drugs). Three classes were observed among n = 596 adolescents on probation: none of the substances predicted outcomes for approximately 18 % of the sample; alcohol and marijuana use were predictive for approximately 59 % of the sample, and marijuana use and hard drug use were predictive in approximately 23 % of the sample. Demographic, individual difference, and additional sexual and substance use risk variables were examined in relation to class membership. Findings are discussed in terms of understanding profiles of risk behavior among at-risk youth.

  10. Modeling interdisciplinary activities involving Mathematics

    DEFF Research Database (Denmark)

    Iversen, Steffen Møllegaard

    2006-01-01

    In this paper a didactical model is presented. The goal of the model is to work as a didactical tool, or conceptual frame, for developing, carrying through and evaluating interdisciplinary activities involving the subject of mathematics and philosophy in the high schools. Through the terms...... domains (Michelsen, 2001, 2005a, 2005b). Furthermore the theoretical description rest on a series of qualitative interviews with teachers from the Danish high school (grades 9-11) conducted recently. The special case of concrete interdisciplinary activities between mathematics and philosophy is also...

  11. Modeling interdisciplinary activities involving Mathematics

    DEFF Research Database (Denmark)

    Iversen, Steffen Møllegaard

    2006-01-01

    In this paper a didactical model is presented. The goal of the model is to work as a didactical tool, or conceptual frame, for developing, carrying through and evaluating interdisciplinary activities involving the subject of mathematics and philosophy in the high schools. Through the terms...... of Horizontal Intertwining, Vertical Structuring and Horizontal Propagation the model consists of three phases, each considering different aspects of the nature of interdisciplinary activities. The theoretical modelling is inspired by work which focuses on the students abilities to concept formation in expanded...... domains (Michelsen, 2001, 2005a, 2005b). Furthermore the theoretical description rest on a series of qualitative interviews with teachers from the Danish high school (grades 9-11) conducted recently. The special case of concrete interdisciplinary activities between mathematics and philosophy is also...

  12. Scaling Consumers' Purchase Involvement: A New Approach

    Directory of Open Access Journals (Sweden)

    Jörg Kraigher-Krainer

    2012-06-01

    Full Text Available A two-dimensional scale, called ECID Scale, is presented in this paper. The scale is based on a comprehensive model and captures the two antecedent factors of purchase-related involvement, namely whether motivation is intrinsic or extrinsic and whether risk is perceived as low or high. The procedure of scale development and item selection is described. The scale turns out to perform well in terms of validity, reliability, and objectivity despite the use of a small set of items – four each – allowing for simultaneous measurements of up to ten purchases per respondent. The procedure of administering the scale is described so that it can now easily be applied by both, scholars and practitioners. Finally, managerial implications of data received from its application which provide insights into possible strategic marketing conclusions are discussed.

  13. Observations involving broadband impedance modelling

    Energy Technology Data Exchange (ETDEWEB)

    Berg, J.S. [Stanford Linear Accelerator Center, Menlo Park, CA (United States)

    1996-08-01

    Results for single- and multi-bunch instabilities can be significantly affected by the precise model that is used for the broadband impedance. This paper discusses three aspects of broadband impedance modelling. The first is an observation of the effect that a seemingly minor change in an impedance model has on the single-bunch mode coupling threshold. The second is a successful attempt to construct a model for the high-frequency tails of an r.f. cavity. The last is a discussion of requirements for the mathematical form of an impedance which follow from the general properties of impedances. (author)

  14. Observations involving broadband impedance modelling

    Energy Technology Data Exchange (ETDEWEB)

    Berg, J.S.

    1995-08-01

    Results for single- and multi-bunch instabilities can be significantly affected by the precise model that is used for the broadband impendance. This paper discusses three aspects of broadband impendance modeling. The first is an observation of the effect that a seemingly minor change in an impedance model has on the single-bunch mode coupling threshold. The second is a successful attempt to construct a model for the high-frequency tails of an r.f cavity. The last is a discussion of requirements for the mathematical form of an impendance which follow from the general properties of impendances.

  15. DSLM Instructional Approach to Conceptual Change Involving Thermal Expansion

    Science.gov (United States)

    She, Hsiao-Ching

    2003-01-01

    This article examines the process of students' conceptual change involving thermal expansion as a result of employing the Dual Situated Learning Model (DSLM) (She, 2001, 2002) as a classroom instructional approach. The dual situated learning events of this model are designed according to the students' ontological viewpoint of the science concepts as well as the nature of these concepts. Moreover, these events serve two functions in creating dissonance with the pre-existing knowledge and providing new schema for constructing a more scientific view of the concept. DSLM has been shown to promote students' conceptual change using one-to-one instructional procedure (She, 2002). This study further demonstrates that DSLM holds great potential to facilitate the conceptual change process involving thermal expansion through classroom instruction, even the difficult concept or higher hierarchical level one.

  16. Integrated Transport Planning Framework Involving Combined Utility Regret Approach

    DEFF Research Database (Denmark)

    Wang, Yang; Monzon, Andres; Di Ciommo, Floridea;

    2014-01-01

    Sustainable transport planning requires an integrated approach involving strategic planning, impact analysis, and multicriteria evaluation. This study aimed at relaxing the utility-based decision-making assumption by newly embedding anticipated-regret and combined utility regret decision mechanisms...... in a framework for integrated transport planning. The framework consisted of a two-round Delphi survey, integrated land use and transport model for Madrid, and multicriteria analysis. Results show that (a) the regret-based ranking has a similar mean but larger variance than the utility-based ranking does, (b...

  17. Bullying Prevention and the Parent Involvement Model

    Science.gov (United States)

    Kolbert, Jered B.; Schultz, Danielle; Crothers, Laura M.

    2014-01-01

    A recent meta-analysis of bullying prevention programs provides support for social-ecological theory, in which parent involvement addressing child bullying behaviors is seen as important in preventing school-based bullying. The purpose of this manuscript is to suggest how Epstein and colleagues' parent involvement model can be used as a…

  18. Modeling human operator involvement in robotic systems

    NARCIS (Netherlands)

    Wewerinke, P.H.

    1991-01-01

    A modeling approach is presented to describe complex manned robotic systems. The robotic system is modeled as a (highly) nonlinear, possibly time-varying dynamic system including any time delays in terms of optimal estimation, control and decision theory. The role of the human operator(s) is modeled

  19. Learning models of activities involving interacting objects

    DEFF Research Database (Denmark)

    Manfredotti, Cristina; Pedersen, Kim Steenstrup; Hamilton, Howard J.;

    2013-01-01

    We propose the LEMAIO multi-layer framework, which makes use of hierarchical abstraction to learn models for activities involving multiple interacting objects from time sequences of data concerning the individual objects. Experiments in the sea navigation domain yielded learned models that were...

  20. Learning models of activities involving interacting objects

    DEFF Research Database (Denmark)

    Manfredotti, Cristina; Pedersen, Kim Steenstrup; Hamilton, Howard J.

    2013-01-01

    We propose the LEMAIO multi-layer framework, which makes use of hierarchical abstraction to learn models for activities involving multiple interacting objects from time sequences of data concerning the individual objects. Experiments in the sea navigation domain yielded learned models that were t...

  1. Teaching Approaches and Student Involvement in Learning to Write

    Directory of Open Access Journals (Sweden)

    Kyeongheui Kim

    2013-06-01

    Full Text Available This study examined the relationship between teaching approaches and the learning involvement of students from Korea in US college level classes by examining what these students did to complete writing assignments required for classes and what approaches professors adopted to assist students with English writing. It also examined how and why their involvement changed from active to less involvement to withdrawal or passive involvement to active involvement. In other words, this study examined how much professors’ teaching approaches influenced students’ attitudes towards English writing. Korean students who grew up in a culture where the whole society regards teachers highly expected more from their professors and were more dependent on professors. It appears that study participants’ English language proficiency also played a role in their dependency on their professors. There was a gap between these students’ expectations for professors and some of their professors’ teaching approaches. Also, there was some professors’ bias perceived by study participants, whether intentional or not, against non-native English speaking students and minority students, which disappointed and frustrated study participants and influenced these students’ degrees of involvement in learning.

  2. Learning models of activities involving interacting objects

    DEFF Research Database (Denmark)

    Manfredotti, Cristina; Pedersen, Kim Steenstrup; Hamilton, Howard J.;

    2013-01-01

    We propose the LEMAIO multi-layer framework, which makes use of hierarchical abstraction to learn models for activities involving multiple interacting objects from time sequences of data concerning the individual objects. Experiments in the sea navigation domain yielded learned models that were...... then successfully applied to activity recognition, activity simulation and multi-target tracking. Our method compares favourably with respect to previously reported results using Hidden Markov Models and Relational Particle Filtering....

  3. Instructor support for new learning approaches involving technology

    NARCIS (Netherlands)

    Bianco, Manuela; Collis, Betty; Cooke, Andy; Margaryan, Anoush

    2002-01-01

    New learning approaches involving technology are occurring in both universities and company training settings. Critical factors in regard to these changes are the professionals in an organisation responsible for course design, development, and delivery: the instructors and those who support them. In

  4. Liver involvement in Gaucher disease - Review and clinical approach.

    Science.gov (United States)

    Adar, Tomer; Ilan, Yaron; Elstein, Deborah; Zimran, Ari

    2016-10-19

    Gaucher disease (GD), one of the most prevalent lysosomal storage diseases, is associated with glucocerebroside accumulation in cells of the monocyte-macrophage system in various organs, including the liver. Evaluating and managing liver disease in patients with Gaucher disease may be challenging. While hepatic involvement is common in Gaucher disease, its severity, and clinical significance span a wide spectrum, ranging from sub-clinical involvement to liver cirrhosis with its associated complications including portal hypertension. Apart from liver involvement in Gaucher disease, patients with may also suffer from other comorbidities involving the liver. That Gaucher disease itself can mimic hepatic lesions, affect laboratory tests used to characterize liver disease, and may be associated with non-cirrhotic portal hypertension, complicates the diagnostic approach even more. Better understanding of liver involvement in Gaucher disease can spare patients unnecessary invasive testing, and assist physicians in decision making when evaluating patients with Gaucher disease suspected for significant liver disease. This review describes the various clinical manifestations, laboratory and imaging abnormalities that may be encountered when following patients with Gaucher disease for liver involvement. The mechanism for liver disease are discussed, as well as the possible hepato-protective effect of glucocerebroside, and the a diagnostic and treatment approaches.

  5. Modeling fault among motorcyclists involved in crashes.

    Science.gov (United States)

    Haque, Md Mazharul; Chin, Hoong Chor; Huang, Helai

    2009-03-01

    Singapore crash statistics from 2001 to 2006 show that the motorcyclist fatality and injury rates per registered vehicle are higher than those of other motor vehicles by 13 and 7 times, respectively. The crash involvement rate of motorcyclists as victims of other road users is also about 43%. The objective of this study is to identify the factors that contribute to the fault of motorcyclists involved in crashes. This is done by using the binary logit model to differentiate between at-fault and not-at-fault cases and the analysis is further categorized by the location of the crashes, i.e., at intersections, on expressways and at non-intersections. A number of explanatory variables representing roadway characteristics, environmental factors, motorcycle descriptions, and rider demographics have been evaluated. Time trend effect shows that not-at-fault crash involvement of motorcyclists has increased with time. The likelihood of night time crashes has also increased for not-at-fault crashes at intersections and expressways. The presence of surveillance cameras is effective in reducing not-at-fault crashes at intersections. Wet-road surfaces increase at-fault crash involvement at non-intersections. At intersections, not-at-fault crash involvement is more likely on single-lane roads or on median lane of multi-lane roads, while on expressways at-fault crash involvement is more likely on the median lane. Roads with higher speed limit have higher at-fault crash involvement and this is also true on expressways. Motorcycles with pillion passengers or with higher engine capacity have higher likelihood of being at-fault in crashes on expressways. Motorcyclists are more likely to be at-fault in collisions involving pedestrians and this effect is higher at night. In multi-vehicle crashes, motorcyclists are more likely to be victims than at-fault. Young and older riders are more likely to be at-fault in crashes than middle-aged group of riders. The findings of this study will help

  6. DSLM Instructional Approach to Conceptual Change Involving Thermal Expansion.

    Science.gov (United States)

    She, Hsiao-Ching

    2003-01-01

    Examines the process of student conceptual change regarding thermal expansion using the Dual Situated Learning Model (DSLM) as an instructional approach. Indicates that DSLM promotes conceptual change and holds great potential to facilitate the process through classroom instruction at all levels. (Contains 38 references.) (Author/NB)

  7. The approaches to the definition of involvement and to types of companies-customers involvement in decision-making process

    Directory of Open Access Journals (Sweden)

    M.Yu. Troian

    2011-10-01

    Full Text Available The approaches to the definition of involvement and toits basic types classification are developed. The classification of types of companies-customers involvement is supplemented. The concept of connotative involvement is defined and scientifically proven. The basic properties of the involvement: the intensity, directionandstability are developed.

  8. Neuropsychiatric involvement in systemic lupus erythematosus: current therapeutic approach.

    Science.gov (United States)

    Sanna, Giovanni; Bertolaccini, Maria Laura; Khamashta, Munther A

    2008-01-01

    The involvement of the central nervous system (CNS) is one of the major causes of morbidity and mortality in systemic lupus erythematosus (SLE) patients and the less understood aspect of the disease. Its recognition and treatment continue to represent a major diagnostic and therapeutic challenge. Due to the lack of controlled randomized trials, current therapeutic approach is still empirical and based on clinical experience. The therapeutic choice depends on accurate diagnosis, identification of underlying pathogenic mechanism, severity of the presenting neuropsychiatric symptoms, and on prompt identification and management of contributing causes of CNS disease. Mild neuropsychiatric manifestations may need symptomatic treatment only. In more severe CNS disease it is important to distinguish between thrombotic and non-thrombotic mechanisms. Focal CNS manifestations, particularly TIA and stroke, are associated with the presence of antiphospholipid antibodies (aPL). Anticoagulation is warranted in patients with thrombotic disease, particularly in those with the antiphospholipid (Hughes) syndrome (APS). Other CNS manifestations, such as demyelinating syndrome, transverse myelitis, chorea, seizures, migraine and/or cognitive dysfunction, when associated with persistent positivity for aPL, may also benefit from anticoagulation in selected patients. Severe diffuse CNS manifestations, such as acute confusional state, generalised seizures, mood disorders and psychosis, generally require corticosteroids in the first instance. Pulse intravenous cyclophosphamide therapy may help when more severe manifestations are refractory to corticosteroids and other immunosuppressive agents, generally when response is not seen in 3-5 days. Plasmapheresis may also be added in severe cases of symptoms refractory to conventional treatment. Intravenous immunoglobulins, mycophenolate mofetil, rituximab, intratecal methotrexate and dexametasone deserve further studies to confirm their

  9. Complement involvement in periodontitis: molecular mechanisms and rational therapeutic approaches

    Science.gov (United States)

    Hajishengallis, George; Maekawa, Tomoki; Abe, Toshiharu; Hajishengallis, Evlambia; Lambris, John D.

    2015-01-01

    The complement system is a network of interacting fluid-phase and cell surface-associated molecules that trigger, amplify, and regulate immune and inflammatory signaling pathways. Dysregulation of this finely balanced network can destabilize host-microbe homeostasis and cause inflammatory tissue damage. Evidence from clinical and animal model-based studies suggests that complement is implicated in the pathogenesis of periodontitis, a polymicrobial community-induced chronic inflammatory disease that destroys the tooth-supporting tissues. This review discusses molecular mechanisms of complement involvement in the dysbiotic transformation of the periodontal microbiome and the resulting destructive inflammation, culminating in loss of periodontal bone support. These mechanistic studies have additionally identified potential therapeutic targets. In this regard, interventional studies in preclinical models have provided proof-of-concept for using complement inhibitors for the treatment of human periodontitis. PMID:26306443

  10. Involving stakeholders in building integrated fisheries models using Bayesian methods.

    Science.gov (United States)

    Haapasaari, Päivi; Mäntyniemi, Samu; Kuikka, Sakari

    2013-06-01

    A participatory Bayesian approach was used to investigate how the views of stakeholders could be utilized to develop models to help understand the Central Baltic herring fishery. In task one, we applied the Bayesian belief network methodology to elicit the causal assumptions of six stakeholders on factors that influence natural mortality, growth, and egg survival of the herring stock in probabilistic terms. We also integrated the expressed views into a meta-model using the Bayesian model averaging (BMA) method. In task two, we used influence diagrams to study qualitatively how the stakeholders frame the management problem of the herring fishery and elucidate what kind of causalities the different views involve. The paper combines these two tasks to assess the suitability of the methodological choices to participatory modeling in terms of both a modeling tool and participation mode. The paper also assesses the potential of the study to contribute to the development of participatory modeling practices. It is concluded that the subjective perspective to knowledge, that is fundamental in Bayesian theory, suits participatory modeling better than a positivist paradigm that seeks the objective truth. The methodology provides a flexible tool that can be adapted to different kinds of needs and challenges of participatory modeling. The ability of the approach to deal with small data sets makes it cost-effective in participatory contexts. However, the BMA methodology used in modeling the biological uncertainties is so complex that it needs further development before it can be introduced to wider use in participatory contexts.

  11. Involving Stakeholders in Building Integrated Fisheries Models Using Bayesian Methods

    Science.gov (United States)

    Haapasaari, Päivi; Mäntyniemi, Samu; Kuikka, Sakari

    2013-06-01

    A participatory Bayesian approach was used to investigate how the views of stakeholders could be utilized to develop models to help understand the Central Baltic herring fishery. In task one, we applied the Bayesian belief network methodology to elicit the causal assumptions of six stakeholders on factors that influence natural mortality, growth, and egg survival of the herring stock in probabilistic terms. We also integrated the expressed views into a meta-model using the Bayesian model averaging (BMA) method. In task two, we used influence diagrams to study qualitatively how the stakeholders frame the management problem of the herring fishery and elucidate what kind of causalities the different views involve. The paper combines these two tasks to assess the suitability of the methodological choices to participatory modeling in terms of both a modeling tool and participation mode. The paper also assesses the potential of the study to contribute to the development of participatory modeling practices. It is concluded that the subjective perspective to knowledge, that is fundamental in Bayesian theory, suits participatory modeling better than a positivist paradigm that seeks the objective truth. The methodology provides a flexible tool that can be adapted to different kinds of needs and challenges of participatory modeling. The ability of the approach to deal with small data sets makes it cost-effective in participatory contexts. However, the BMA methodology used in modeling the biological uncertainties is so complex that it needs further development before it can be introduced to wider use in participatory contexts.

  12. Isotope exchange reactions involving HCO+ with CO: A theoretical approach

    Science.gov (United States)

    Mladenović, M.; Roueff, E.

    2017-09-01

    Aims: We aim to investigate fractionation reactions involved in the 12C/13C, 16O/18O, and 17O balance. Methods: Full-dimensional rovibrational calculations were used to compute numerically exact rovibrational energies and thermal equilibrium conditions to derive the reaction rate coefficients. A nonlinear least-squares method was employed to represent the rate coefficients by analytic functions. Results: New exothermicities are derived for 30 isotopic exchange reactions of HCO+ with CO. For each of the reactions, we provide the analytic three-parameter Arrhenius-Kooij formula for both the forward reaction and backward reaction rate coefficients, that can further be used in astrochemical kinetic models. Rotational constants derived here for the 17O containing forms of HCO+ may assist detection of these cations in outer space.

  13. Teacher Training in Family Involvement: An Interpersonal Approach.

    Science.gov (United States)

    Coleman, Mick; Wallinga, Charlotte

    2000-01-01

    Discusses ways to develop family-school-community involvement, based on an early childhood teacher training course in family involvement. Discusses strategies for using Maslow's Hierarchy of Needs to facilitate family involvement interactions, and using student teachers' experiences for structuring reflective thought about family involvement…

  14. Teacher Training in Family Involvement: An Interpersonal Approach.

    Science.gov (United States)

    Coleman, Mick; Wallinga, Charlotte

    2000-01-01

    Discusses ways to develop family-school-community involvement, based on an early childhood teacher training course in family involvement. Discusses strategies for using Maslow's Hierarchy of Needs to facilitate family involvement interactions, and using student teachers' experiences for structuring reflective thought about family involvement…

  15. Managing supplier involvement in new product development: a portfolio approach

    NARCIS (Netherlands)

    Wynstra, Finn; Pierick, ten Eric

    2000-01-01

    Supplier involvement in new product development projects has become an increasingly popular method for improving project effectiveness (product costs and quality) and project efficiency (development costs and time). One of the key issues in managing this involvement is determining which type of invo

  16. Parental Involvement in Elementary Children's Religious Education: A Phenomenological Approach

    Science.gov (United States)

    Bunnell, Peter Wayne

    2016-01-01

    The issue of parental involvement in religious education is an important one for the family, the church, the Christian school, and society. The purpose of this phenomenological study was to describe parents' concepts and practices of involvement in their children's religious education as evangelical Christian parents in Midwestern communities.…

  17. Managing supplier involvement in new product development: a portfolio approach

    NARCIS (Netherlands)

    Wynstra, Finn; ten Pierick, E.

    2000-01-01

    Supplier involvement in new product development projects has become an increasingly popular method for improving project effectiveness (product costs and quality) and project efficiency (development costs and time). One of the key issues in managing this involvement is determining which type of invo

  18. Buried Waste Integrated Demonstration stakeholder involvement model

    Energy Technology Data Exchange (ETDEWEB)

    Kaupanger, R.M.; Kostelnik, K.M.; Milam, L.M.

    1994-04-01

    The Buried Waste Integrated Demonstration (BWID) is a program funded by the US Department of Energy (DOE) Office of Technology Development. BWID supports the applied research, development, demonstration, and evaluation of a suite of advanced technologies that together form a comprehensive remediation system for the effective and efficient remediation of buried waste. Stakeholder participation in the DOE Environmental Management decision-making process is critical to remediation efforts. Appropriate mechanisms for communication with the public, private sector, regulators, elected officials, and others are being aggressively pursued by BWID to permit informed participation. This document summarizes public outreach efforts during FY-93 and presents a strategy for expanded stakeholder involvement during FY-94.

  19. Challenges in structural approaches to cell modeling.

    Science.gov (United States)

    Im, Wonpil; Liang, Jie; Olson, Arthur; Zhou, Huan-Xiang; Vajda, Sandor; Vakser, Ilya A

    2016-07-31

    Computational modeling is essential for structural characterization of biomolecular mechanisms across the broad spectrum of scales. Adequate understanding of biomolecular mechanisms inherently involves our ability to model them. Structural modeling of individual biomolecules and their interactions has been rapidly progressing. However, in terms of the broader picture, the focus is shifting toward larger systems, up to the level of a cell. Such modeling involves a more dynamic and realistic representation of the interactomes in vivo, in a crowded cellular environment, as well as membranes and membrane proteins, and other cellular components. Structural modeling of a cell complements computational approaches to cellular mechanisms based on differential equations, graph models, and other techniques to model biological networks, imaging data, etc. Structural modeling along with other computational and experimental approaches will provide a fundamental understanding of life at the molecular level and lead to important applications to biology and medicine. A cross section of diverse approaches presented in this review illustrates the developing shift from the structural modeling of individual molecules to that of cell biology. Studies in several related areas are covered: biological networks; automated construction of three-dimensional cell models using experimental data; modeling of protein complexes; prediction of non-specific and transient protein interactions; thermodynamic and kinetic effects of crowding; cellular membrane modeling; and modeling of chromosomes. The review presents an expert opinion on the current state-of-the-art in these various aspects of structural modeling in cellular biology, and the prospects of future developments in this emerging field. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Vessel involvement in giant cell arteritis : an imaging approach

    NARCIS (Netherlands)

    Holm, Pieter W; Sandovici, Maria; Slart, Riemer H.; Glaudemans, Andor W; Rutgers, Abraham; Brouwer, Elisabeth

    2016-01-01

    Vasculitis is classified based on the size of the involved vessels. The two major forms are small vessel vasculitis (SVV) and large vessel vasculitis (LVV). Main forms of LVV are Takayasu Arteritis (TA), Giant Cell Arteritis (GCA), Isolated Aortitis (IA) and Chronic Periaortitis (PC). This manuscrip

  1. Involving the Young: The German Approach to Vocational Education

    Science.gov (United States)

    Hirche, Walter

    2012-01-01

    Youth unemployment is a huge challenge for sustainable development in our societies. Statistics offer an alarming picture of the involvement of youth in the labour markets on a global scale. Germany, due to a strong tradition in vocational education and training deeply rooted in its culture, has very low rates of youth unemployment. The so-called…

  2. Multiple Model Approaches to Modelling and Control,

    DEFF Research Database (Denmark)

    Why Multiple Models?This book presents a variety of approaches which produce complex models or controllers by piecing together a number of simpler subsystems. Thisdivide-and-conquer strategy is a long-standing and general way of copingwith complexity in engineering systems, nature and human probl...

  3. Molecular Genetic Approaches to Human Diseases Involving Mental Retardation.

    Science.gov (United States)

    Latt, Samuel A.; And Others

    1984-01-01

    Recombinant DNA techniques provide new approaches to the diagnosis and analysis of inherited human diseases associated with mental retardation, such as Lesch-Nyhan syndrome, phenylketonauria, the Fragile X syndrome, Down syndrome, and those associated with deletions or duplications of subchromosomal regions. (Author/CL)

  4. Governance of environmental risk: new approaches to managing stakeholder involvement.

    Science.gov (United States)

    Benn, Suzanne; Dunphy, Dexter; Martin, Andrew

    2009-04-01

    Disputes concerning industrial legacies such as the disposal of toxic wastes illustrate changing pressures on corporations and governments. Business and governments are now confronted with managing the expectations of a society increasingly aware of the social and environmental impacts and risks associated with economic development and demanding more equitable distribution and democratic management of such risks. The closed managerialist decision-making of the powerful bureaucracies and corporations of the industrial era is informed by traditional management theory which cannot provide a framework for the adequate governance of these risks. Recent socio-political theories have conceptualised some key themes that must be addressed in a more fitting approach to governance. We identify more recent management and governance theory which addresses these themes and develop a process-based approach to governance of environmental disputes that allows for the evolving nature of stakeholder relations in a highly complex multiple stakeholder arena.

  5. Visualization of a City Sustainability Index (CSI: Towards Transdisciplinary Approaches Involving Multiple Stakeholders

    Directory of Open Access Journals (Sweden)

    Koichiro Mori

    2015-09-01

    Full Text Available We have developed a visualized 3-D model of a City Sustainability Index (CSI based on our original concept of city sustainability in which a sustainable city is defined as one that maximizes socio-economic benefits while meeting constraint conditions of the environment and socio-economic equity on a permanent basis. The CSI is based on constraint and maximization indicators. Constraint indicators assess whether a city meets the necessary minimum conditions for city sustainability. Maximization indicators measure the benefits that a city generates in socio-economic aspects. When used in the policy-making process, the choice of constraint indicators should be implemented using a top-down approach. In contrast, a bottom-up approach is more suitable for defining maximization indicators because this technique involves multiple stakeholders (in a transdisciplinary approach. Using different materials of various colors, shapes, sizes, we designed and constructed the visualized physical model of the CSI to help people evaluate and compare the performance of different cities in terms of sustainability. The visualized model of the CSI can convey complicated information in a simple and straightforward manner to diverse stakeholders so that the sustainability analysis can be understood intuitively by ordinary citizens as well as experts. Thus, the CSI model helps stakeholders to develop critical thinking about city sustainability and enables policymakers to make informed decisions for sustainability through a transdisciplinary approach.

  6. "Involving interface": an extended mind theoretical approach to roboethics.

    Science.gov (United States)

    Anderson, Miranda; Ishiguro, Hiroshi; Fukushi, Tamami

    2010-11-01

    In 2008 the authors held "Involving Interface," a lively interdisciplinary event focusing on issues of biological, sociocultural, and technological interfacing (see Acknowledgments). Inspired by discussions at this event, in this article, we further discuss the value of input from neuroscience for developing robots and machine interfaces, and the value of philosophy, the humanities, and the arts for identifying persistent links between human interfacing and broader ethical concerns. The importance of ongoing interdisciplinary debate and public communication on scientific and technical advances is also highlighted. Throughout, the authors explore the implications of the extended mind hypothesis for notions of moral accountability and robotics.

  7. MELAS Syndrome with Cardiac Involvement: A Multimodality Imaging Approach

    Directory of Open Access Journals (Sweden)

    Sara Seitun

    2016-01-01

    Full Text Available A 49-year-old man presented with chest pain, dyspnea, and lactic acidosis. Left ventricular hypertrophy and myocardial fibrosis were detected. The sequencing of mitochondrial genome (mtDNA revealed the presence of A to G mtDNA point mutation at position 3243 (m.3243A>G in tRNALeu(UUR gene. Diagnosis of cardiac involvement in a patient with Mitochondrial Encephalomyopathy, Lactic Acidosis, and Stroke-like episodes syndrome (MELAS was made. Due to increased risk of sudden cardiac death, cardioverter defibrillator was implanted.

  8. Multiple Model Approaches to Modelling and Control,

    DEFF Research Database (Denmark)

    on the ease with which prior knowledge can be incorporated. It is interesting to note that researchers in Control Theory, Neural Networks,Statistics, Artificial Intelligence and Fuzzy Logic have more or less independently developed very similar modelling methods, calling them Local ModelNetworks, Operating...... of introduction of existing knowledge, as well as the ease of model interpretation. This book attempts to outlinemuch of the common ground between the various approaches, encouraging the transfer of ideas.Recent progress in algorithms and analysis is presented, with constructive algorithms for automated model...

  9. Model Construct Based Enterprise Model Architecture and Its Modeling Approach

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In order to support enterprise integration, a kind of model construct based enterprise model architecture and its modeling approach are studied in this paper. First, the structural makeup and internal relationships of enterprise model architecture are discussed. Then, the concept of reusable model construct (MC) which belongs to the control view and can help to derive other views is proposed. The modeling approach based on model construct consists of three steps, reference model architecture synthesis, enterprise model customization, system design and implementation. According to MC based modeling approach a case study with the background of one-kind-product machinery manufacturing enterprises is illustrated. It is shown that proposal model construct based enterprise model architecture and modeling approach are practical and efficient.

  10. Stormwater infiltration trenches: a conceptual modelling approach.

    Science.gov (United States)

    Freni, Gabriele; Mannina, Giorgio; Viviani, Gaspare

    2009-01-01

    In recent years, limitations linked to traditional urban drainage schemes have been pointed out and new approaches are developing introducing more natural methods for retaining and/or disposing of stormwater. These mitigation measures are generally called Best Management Practices or Sustainable Urban Drainage System and they include practices such as infiltration and storage tanks in order to reduce the peak flow and retain part of the polluting components. The introduction of such practices in urban drainage systems entails an upgrade of existing modelling frameworks in order to evaluate their efficiency in mitigating the impact of urban drainage systems on receiving water bodies. While storage tank modelling approaches are quite well documented in literature, some gaps are still present about infiltration facilities mainly dependent on the complexity of the involved physical processes. In this study, a simplified conceptual modelling approach for the simulation of the infiltration trenches is presented. The model enables to assess the performance of infiltration trenches. The main goal is to develop a model that can be employed for the assessment of the mitigation efficiency of infiltration trenches in an integrated urban drainage context. Particular care was given to the simulation of infiltration structures considering the performance reduction due to clogging phenomena. The proposed model has been compared with other simplified modelling approaches and with a physically based model adopted as benchmark. The model performed better compared to other approaches considering both unclogged facilities and the effect of clogging. On the basis of a long-term simulation of six years of rain data, the performance and the effectiveness of an infiltration trench measure are assessed. The study confirmed the important role played by the clogging phenomenon on such infiltration structures.

  11. Combinatorial Model Involving Stochastic Choices of Destination, Mode and Route

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Traffic assignment models are one of the basic tools for the analysis and design of transportation systems. However, the existing models have some defects. Considering the characteristics of Chinese urban mixed traffic and the randomness of transportation information, the author develops a combinatorial model involving stochastic choices of destination, mode and route. Its uniqueness and equivalance are also proved by the optimization theory.

  12. Hydraulic Modeling of Lock Approaches

    Science.gov (United States)

    2016-08-01

    cation was that the guidewall design changed from a solid wall to one on pilings in which water was allowed to flow through and/or under the wall ...develops innovative solutions in civil and military engineering, geospatial sciences, water resources, and environmental sciences for the Army, the...magnitudes and directions at lock approaches for open river conditions. The meshes were developed using the Surface- water Modeling System. The two

  13. LP Approach to Statistical Modeling

    OpenAIRE

    Mukhopadhyay, Subhadeep; Parzen, Emanuel

    2014-01-01

    We present an approach to statistical data modeling and exploratory data analysis called `LP Statistical Data Science.' It aims to generalize and unify traditional and novel statistical measures, methods, and exploratory tools. This article outlines fundamental concepts along with real-data examples to illustrate how the `LP Statistical Algorithm' can systematically tackle different varieties of data types, data patterns, and data structures under a coherent theoretical framework. A fundament...

  14. General patterns of managerial approaches to work motivation: Implications for rehabilitation professionals involved in occupational rehabilitation.

    Science.gov (United States)

    Murphy, G C; Foreman, P

    1993-03-01

    Calls for rehabilitation counselors to learn more about the world of work have been recently repeated. The validity of these calls is suggested by a group of studies which indicate that the rehabilitation counseling literature has an established emphasis on matters of counseling and adjustment rather than on matters related to behavior in organizations. A survey of rehabilitation counsellors' beliefs about key topics in organizational behavior indicates that their beliefs are often discrepant with those of practicing managers and supervisors. A summary of dominant models of work motivation adopted by managerial workers is presented and some implications for occupational rehabilitation practice identified. Finally, some contemporary literature relevant to managerial approaches to employee motivation are identified and it is suggested that familiarity with this literature could assist rehabilitation practitioners move from a more narrow occupational rehabilitation role to a broader involvement in organizational life via the expansion of the disability management approach in work organizations.

  15. Neuropsychiatric Systemic Lupus Erythematosus Involvement: Towards a Tailored Approach to Our Patients?

    Directory of Open Access Journals (Sweden)

    Raquel Faria

    2017-01-01

    Full Text Available Neuropsychiatric involvement in systemic lupus erythematosus (NPSLE is a complex condition that remains poorly understood, and includes heterogeneous manifestations involving both the central and peripheral nervous system, with disabling effects. There are several models to improve NPSLE diagnosis when a neurological syndrome is present. In the last couple of years, the growing knowledge of the role of cytokines and antibodies in NPSLE, as well as the development of new functional imaging techniques, has brought some insights into the physiopathology of the disease, but their validation for clinical use remains undetermined. Furthermore, besides the classic clinical approach, a new tool for screening the 19 NPSLE syndromes has also been developed. Regarding NPSLE therapeutics, there is still no evidence-based treatment approach, but some data support the safety of biological medication when classic treatment fails. Despite the tendency to reclassify SLE patients in clinical and immunological subsets, we hope that these data will inspire medical professionals to approach NPSLE in a manner more tailored to the individual patient.

  16. Five challenges for stochastic epidemic models involving global transmission

    Directory of Open Access Journals (Sweden)

    Tom Britton

    2015-03-01

    Full Text Available The most basic stochastic epidemic models are those involving global transmission, meaning that infection rates depend only on the type and state of the individuals involved, and not on their location in the population. Simple as they are, there are still several open problems for such models. For example, when will such an epidemic go extinct and with what probability (questions depending on the population being fixed, changing or growing? How can a model be defined explaining the sometimes observed scenario of frequent mid-sized epidemic outbreaks? How can evolution of the infectious agent transmission rates be modelled and fitted to data in a robust way?

  17. A consumer involvement model for health technology assessment in Canada.

    Science.gov (United States)

    Pivik, Jayne; Rode, Elisabeth; Ward, Christopher

    2004-08-01

    Similar to other health policy initiatives, there is a growing movement to involve consumers in decisions affecting their treatment options. Access to treatments can be impacted by decisions made during a health technology assessment (HTA), i.e., the rigorous assessment of medical interventions such as drugs, vaccines, devices, materials, medical and surgical procedures and systems. The purpose of this paper was to empirically assess the interest and potential mechanisms for consumer involvement in HTA by identifying what health consumer organizations consider meaningful involvement, examining current practices internationally and developing a model for involvement based on identified priorities and needs. Canadian health consumer groups representing the largest disease or illness conditions reported a desire for involvement in HTA and provided feedback on mechanisms for facilitating their involvement.

  18. Approaches to Modeling of Recrystallization

    Directory of Open Access Journals (Sweden)

    Håkan Hallberg

    2011-10-01

    Full Text Available Control of the material microstructure in terms of the grain size is a key component in tailoring material properties of metals and alloys and in creating functionally graded materials. To exert this control, reliable and efficient modeling and simulation of the recrystallization process whereby the grain size evolves is vital. The present contribution is a review paper, summarizing the current status of various approaches to modeling grain refinement due to recrystallization. The underlying mechanisms of recrystallization are briefly recollected and different simulation methods are discussed. Analytical and empirical models, continuum mechanical models and discrete methods as well as phase field, vertex and level set models of recrystallization will be considered. Such numerical methods have been reviewed previously, but with the present focus on recrystallization modeling and with a rapidly increasing amount of related publications, an updated review is called for. Advantages and disadvantages of the different methods are discussed in terms of applicability, underlying assumptions, physical relevance, implementation issues and computational efficiency.

  19. Transactional Models Between Personality and Alcohol Involvement: A Further Examination

    OpenAIRE

    2012-01-01

    Although correlated changes between personality and alcohol involvement have been shown, the functional relation between these constructs is also of theoretical and clinical interest. Using bivariate latent difference score models, we examined transactional relations (i.e., personality predicting changes in alcohol involvement, which in turn predicts changes in personality) across two distinct but overlapping developmental time frames (i.e., across college and during young adulthood) using tw...

  20. Lithium-ion batteries modeling involving fractional differentiation

    Science.gov (United States)

    Sabatier, Jocelyn; Merveillaut, Mathieu; Francisco, Junior Mbala; Guillemard, Franck; Porcelatto, Denis

    2014-09-01

    With hybrid and electric vehicles development, automobile battery monitoring systems (BMS) have to meet the new requirements. These systems have to give information on state of health, state of charge, available power. To get this information, BMS often implement battery models. Accuracy of the information manipulated by the BMS thus depends on the model accuracy. This paper is within this framework and addresses lithium-ion battery modeling. The proposed fractional model is based on simplifications of an electrochemical model and on resolution of some partial differential equations used in its description. Such an approach permits to get a simple model in which electrochemical variables and parameters still appear.

  1. The role of patient involvement in the diagnostic process in internal medicine: a cognitive approach.

    Science.gov (United States)

    Lucchiari, Claudio; Pravettoni, Gabriella

    2013-07-01

    Much cognitive and clinical research has addressed clinical reasoning, pointing out that physicians often have difficulties in following a linear course when making accurate diagnoses. Some authors suspect that physicians make mistakes because they unknowingly fail to observe the laws of formal logic and that their reasoning becomes influenced by contextual factors. In this paper, we introduce some basic principles of the cognitive approach to medical decision making and we describe the cognitive balanced model. Then we discuss the relationship between construction of mental models, cognitive biases and patient involvement by the use of a clinical vignette. Medical decisions may be considered fundamentally biased since the use of judgment heuristics and a combination of cognitive-related and system-related factors limit physicians' rationality. While traditional understanding of clinical reasoning has failed to consider contextual factors, most techniques designed to avoid biases seem to fail in promoting sound and safer medical practice. In particular, we argue that an unbiased process requires the use of a cognitive balanced model, in which analytical and intuitive mind skills should be properly integrated. In order to improve medical decision making and thereby lessen incidence of adverse events, it is fundamental to include the patient perspective in a balanced model. Physicians and patients should improve their collective intelligence by sharing mental models within a framework of distributed intelligence. Copyright © 2013 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

  2. An Involvement-Oriented Approach in a Medium-Sized Marketing Principles Class.

    Science.gov (United States)

    McCorkle, Denny E.; And Others

    1992-01-01

    Presents a proposed involvement-oriented solution to the lecture/discussion and multiple-choice/essay dilemma confronting business classes. The approach is designed to increase the level of active student learning. (JOW)

  3. Positive Solutions for a Competition Model with an Inhibitor Involved

    Institute of Scientific and Technical Information of China (English)

    Bin Chen

    2008-01-01

    In the paper, we study the positive solutions of a diffusive competition model with an inhibitor involved subject to the homogeneous Dirichlet boundary condition. The existence, uniqueness, stability and multiplicity of positive solutions are discussed. This is mainly done by using the local and global bifurcation theory.

  4. A Process Model of Organizational Commitment and Job Involvement.

    Science.gov (United States)

    1982-09-01

    AD-A123 043 A PROCESS MODEL OF ORGANIZATIONAL COMMITMENT AND JOB I INVOLVEMENT(U) AIR FORCE INST OF TECH WR IGHT PATTERSON AFB OH SCHOL OF SYSTEMS...Appo @1 inu pubo 01004 Aocesston For NTIS CRA&I DTIC TAB Unannounced 0I Justfication - gI, Distr" ’ut ioi / Af t A PROCESS MODEL OF ORGANIZATIONAL...GOVT ACCESSION NO. 3. RECIPIENT’S CATALOG NUMBER LSSR 76-82 1,3b - 4. TITLE (and Subtitle) S. TYPE OF REPORT & PERIOD COVERED A PROCESS MODEL OF

  5. Environmental Management Model for Road Maintenance Operation Involving Community Participation

    Science.gov (United States)

    Triyono, A. R. H.; Setyawan, A.; Sobriyah; Setiono, P.

    2017-07-01

    Public expectations of Central Java, which is very high on demand fulfillment, especially road infrastructure as outlined in the number of complaints and community expectations tweeter, Short Mail Massage (SMS), e-mail and public reports from various media, Highways Department of Central Java province requires development model of environmental management in the implementation of a routine way by involving the community in order to fulfill the conditions of a representative, may serve road users safely and comfortably. This study used survey method with SEM analysis and SWOT with Latent Independent Variable (X), namely; Public Participation in the regulation, development, construction and supervision of road (PSM); Public behavior in the utilization of the road (PMJ) Provincial Road Service (PJP); Safety in the Provincial Road (KJP); Integrated Management System (SMT) and latent dependent variable (Y) routine maintenance of the provincial road that is integrated with the environmental management system and involve the participation of the community (MML). The result showed the implementation of routine maintenance of road conditions in Central Java province has yet to implement an environmental management by involving the community; Therefore developed environmental management model with the results of H1: Community Participation (PSM) has positive influence on the Model of Environmental Management (MML); H2: Behavior Society in Jalan Utilization (PMJ) positive effect on Model Environmental Management (MML); H3: Provincial Road Service (PJP) positive effect on Model Environmental Management (MML); H4: Safety in the Provincial Road (KJP) positive effect on Model Environmental Management (MML); H5: Integrated Management System (SMT) has positive influence on the Model of Environmental Management (MML). From the analysis obtained formulation model describing the relationship / influence of the independent variables PSM, PMJ, PJP, KJP, and SMT on the dependent variable

  6. A COUPLED MORPHODYNAMIC MODEL FOR APPLICATIONS INVOLVING WETTING AND DRYING*

    Institute of Scientific and Technical Information of China (English)

    LIANG Qiuhua

    2011-01-01

    This work presents a new finite volume Godunov-type model for predicting morphological changes under the rapidly varying flood conditions with wetting and drying. The model solves the coupled shallow water and Exner equations, with the interface fluxes evaluated by an Harten-Lax-van Leer-Contact (HLLC) approximate Riemann solver. Well-balanced solution is achieved using the surface gradient method and wetting and drying are handled by a non-negative reconstruction approach. The new model is validated against several theoretical benchmark tests and promising results are obtained.

  7. An Alternative Approach for Nonlinear Latent Variable Models

    Science.gov (United States)

    Mooijaart, Ab; Bentler, Peter M.

    2010-01-01

    In the last decades there has been an increasing interest in nonlinear latent variable models. Since the seminal paper of Kenny and Judd, several methods have been proposed for dealing with these kinds of models. This article introduces an alternative approach. The methodology involves fitting some third-order moments in addition to the means and…

  8. User involvement in long-term care. Towards a relational care-ethics approach.

    Science.gov (United States)

    Abma, Tineke A; Baur, Vivianne E

    2015-12-01

    User involvement in long-term care has become official policy in many countries. Procedural and managerial approaches to user involvement have numerous shortcomings in long-term care. What is needed is a different approach that is beneficial and tuned to the needs of clients and professionals. This article presents a care-ethics approach to involvement. We illustrate this approach and its practical implementation by examining a case example of user involvement in long-term elderly care. This case example is based on an action research project in a residential care home in the Netherlands. Seven female clients participated in the process, as well as diverse groups of professionals from this residential care home. The clients were concerned about meals, and collectively they became empowered and came up with ideas for improving meals. Professionals also shared the clients' experiences with meals, first in homogeneous groups and then in heterogeneous meetings with the client group. This process led to the development of partnership relations between clients and professionals. Our findings suggest that a care-ethics approach to user involvement is a means to increase resident empowerment in long-term care. Clients and professionals start sharing their experiences and values through dialogue, and they develop mutual trust and openness while doing so. © 2014 John Wiley & Sons Ltd.

  9. Hybrid transfinite element modeling/analysis of nonlinear heat conduction problems involving phase change

    Science.gov (United States)

    Tamma, Kumar K.; Railkar, Sudhir B.

    1988-01-01

    The present paper describes the applicability of hybrid transfinite element modeling/analysis formulations for nonlinear heat conduction problems involving phase change. The methodology is based on application of transform approaches and classical Galerkin schemes with finite element formulations to maintain the modeling versatility and numerical features for computational analysis. In addition, in conjunction with the above, the effects due to latent heat are modeled using enthalpy formulations to enable a physically realistic approximation to be dealt computationally for materials exhibiting phase change within a narrow band of temperatures. Pertinent details of the approach and computational scheme adapted are described in technical detail. Numerical test cases of comparative nature are presented to demonstrate the applicability of the proposed formulations for numerical modeling/analysis of nonlinear heat conduction problems involving phase change.

  10. Modeling supercritical fluid extraction process involving solute-solid interaction

    Energy Technology Data Exchange (ETDEWEB)

    Goto, M.; Roy, B. Kodama, A.; Hirose, T. [Kumamoto Univ., Kumamoto (Japan)

    1998-04-01

    Extraction or leaching of solute from natural solid material is a mass transfer process involving dissolution or release of solutes from a solid matrix. Interaction between the solute and solid matrix often influences the supercritical fluid extraction process. A model accounting for the solute-solid interaction as well as mass transfer is developed. The BET equation is used to incorporate the interaction and the solubility of solutes into the local equilibrium in the model. Experimental data for the supercritical extraction of essential oil and cuticular wax from peppermint leaves are successfully analyzed by the model. The effects of parameters on the extraction behavior are demonstrated to illustrate the concept of the model. 18 refs., 5 figs., 1 tab.

  11. Validation of Modeling Flow Approaching Navigation Locks

    Science.gov (United States)

    2013-08-01

    instrumentation, direction vernier . ........................................................................ 8  Figure 11. Plan A lock approach, upstream approach...13-9 8 Figure 9. Tools and instrumentation, bracket attached to rail. Figure 10. Tools and instrumentation, direction vernier . Numerical model

  12. Transthoracic approach for lesions involving the anterior dorsal spine: A multidisciplinary approach with good outcomes

    Directory of Open Access Journals (Sweden)

    Srikant Balasubramaniam

    2016-01-01

    Materials and Methods: A total of 16 patients were operated for varying lesions of body of dorsal vertebra by the transthoracic approach. The study was for a period of 5 years from January 2011 to December 2015. Patients age ranged from 25 to 61 years with an average of 36.4 yrs. There were 7 males and 9 females. In our series 9 patients had Kochs spine, 4 patients were traumatic fracture spine and 3 had neoplastic lesion. Majority of patients had multiple symptoms with backache being present in all patients. Results: There was one post operative mortality which was unrelated to surgery. One patient had post operative delayed kyphosis. Remaining patients improved in their symptoms following surgery. Conclusion: With careful coordination by thoracic surgeons, neurospinal surgeons and anaesthetists, the anterior spine approach for dorsal spine is safe and effective. Adequate preoperative evaluation should stratify the risk and institute measures to reduce it. Accurate surgical planning and careful surgical technique are the key to yield a good outcome and to reduce the risk of complications.

  13. Model Mapping Approach Based on Ontology Semantics

    Directory of Open Access Journals (Sweden)

    Jinkui Hou

    2013-09-01

    Full Text Available The mapping relations between different models are the foundation for model transformation in model-driven software development. On the basis of ontology semantics, model mappings between different levels are classified by using structural semantics of modeling languages. The general definition process for mapping relations is explored, and the principles of structure mapping are proposed subsequently. The approach is further illustrated by the mapping relations from class model of object oriented modeling language to the C programming codes. The application research shows that the approach provides a theoretical guidance for the realization of model mapping, and thus can make an effective support to model-driven software development

  14. Customer involvement in greening the supply chain: an interpretive structural modeling methodology

    Science.gov (United States)

    Kumar, Sanjay; Luthra, Sunil; Haleem, Abid

    2013-04-01

    The role of customers in green supply chain management needs to be identified and recognized as an important research area. This paper is an attempt to explore the involvement aspect of customers towards greening of the supply chain (SC). An empirical research approach has been used to collect primary data to rank different variables for effective customer involvement in green concept implementation in SC. An interpretive structural-based model has been presented, and variables have been classified using matrice d' impacts croises- multiplication appliqué a un classement analysis. Contextual relationships among variables have been established using experts' opinions. The research may help practicing managers to understand the interaction among variables affecting customer involvement. Further, this understanding may be helpful in framing the policies and strategies to green SC. Analyzing interaction among variables for effective customer involvement in greening SC to develop the structural model in the Indian perspective is an effort towards promoting environment consciousness.

  15. Place Branding and Citizen Involvement: Participatory Approach to Building and Managing City Brands

    Directory of Open Access Journals (Sweden)

    Hereźniak Marta

    2017-06-01

    Full Text Available This article examines the role of citizens in the process of building and managing city brands. A multidisciplinary approach is applied to explain the multifaceted nature of territorial brands and citizen involvement. To this end, theoretical concepts from marketing and corporate branding, public management, and human geography are applied. By conceptualising place branding as a public policy and a governance process, and drawing from the concept of participatory place branding, the author discusses a variety of methods and instruments used to involve citizens. Special attention is given to the importance of modern technologies for effective citizen involvement.

  16. Proposed best practice for projects that involve modelling and simulation.

    Science.gov (United States)

    O'Kelly, Michael; Anisimov, Vladimir; Campbell, Chris; Hamilton, Sinéad

    2017-03-01

    Modelling and simulation has been used in many ways when developing new treatments. To be useful and credible, it is generally agreed that modelling and simulation should be undertaken according to some kind of best practice. A number of authors have suggested elements required for best practice in modelling and simulation. Elements that have been suggested include the pre-specification of goals, assumptions, methods, and outputs. However, a project that involves modelling and simulation could be simple or complex and could be of relatively low or high importance to the project. It has been argued that the level of detail and the strictness of pre-specification should be allowed to vary, depending on the complexity and importance of the project. This best practice document does not prescribe how to develop a statistical model. Rather, it describes the elements required for the specification of a project and requires that the practitioner justify in the specification the omission of any of the elements and, in addition, justify the level of detail provided about each element. This document is an initiative of the Special Interest Group for modelling and simulation. The Special Interest Group for modelling and simulation is a body open to members of Statisticians in the Pharmaceutical Industry and the European Federation of Statisticians in the Pharmaceutical Industry. Examples of a very detailed specification and a less detailed specification are included as appendices. Copyright © 2016 John Wiley & Sons, Ltd.

  17. Learning Action Models: Qualitative Approach

    NARCIS (Netherlands)

    Bolander, T.; Gierasimczuk, N.; van der Hoek, W.; Holliday, W.H.; Wang, W.-F.

    2015-01-01

    In dynamic epistemic logic, actions are described using action models. In this paper we introduce a framework for studying learnability of action models from observations. We present first results concerning propositional action models. First we check two basic learnability criteria: finite

  18. Factors Affecting the Involvement of Teachers in Guidance and Counselling as a Whole-School Approach

    Science.gov (United States)

    Lam, Sarah K. Y.; Hui, Eadaoin K. P.

    2010-01-01

    This study explores factors affecting the involvement of regular secondary school teachers in the whole-school approach to guidance and counselling by interviewing 12 secondary school teachers in Hong Kong. Emerging themes include teachers' ownership of their role in student guidance and counselling, the alignment of their disposition with…

  19. Reflections on Practical Approaches to Involving Children and Young People in the Data Analysis Process

    Science.gov (United States)

    Coad, Jane; Evans, Ruth

    2008-01-01

    This article reflects on key methodological issues emerging from children and young people's involvement in data analysis processes. We outline a pragmatic framework illustrating different approaches to engaging children, using two case studies of children's experiences of participating in data analysis. The article highlights methods of…

  20. Reflections on Practical Approaches to Involving Children and Young People in the Data Analysis Process

    Science.gov (United States)

    Coad, Jane; Evans, Ruth

    2008-01-01

    This article reflects on key methodological issues emerging from children and young people's involvement in data analysis processes. We outline a pragmatic framework illustrating different approaches to engaging children, using two case studies of children's experiences of participating in data analysis. The article highlights methods of…

  1. Mathematical modeling of variables involved in dissolution testing.

    Science.gov (United States)

    Gao, Zongming

    2011-11-01

    Dissolution testing is an important technique used for development and quality control of solid oral dosage forms of pharmaceutical products. However, the variability associated with this technique, especially with USP apparatuses 1 and 2, is a concern for both the US Food and Drug Administration and pharmaceutical companies. Dissolution testing involves a number of variables, which can be divided into four main categories: (1) analyst, (2) dissolution apparatus, (3) testing environment, and (4) sample. Both linear and nonlinear models have been used to study dissolution profiles, and various mathematical functions have been used to model the observed data. In this study, several variables, including dissolved gases in the dissolution medium, off-center placement of the test tablet, environmental vibration, and various agitation speeds, were modeled. Mathematical models including Higuchi, Korsmeyer-Peppas, Weibull, and the Noyes-Whitney equation were employed to study the dissolution profile of 10 mg prednisone tablets (NCDA #2) using the USP paddle method. The results showed that the nonlinear models (Korsmeyer-Peppas and Weibull) accurately described the entire dissolution profile. The results also showed that dissolution variables affected dissolution rate constants differently, depending on whether the tablets disintegrated or dissolved.

  2. Learning Actions Models: Qualitative Approach

    DEFF Research Database (Denmark)

    Bolander, Thomas; Gierasimczuk, Nina

    2015-01-01

    —they are identifiable in the limit.We then move on to a particular learning method, which proceeds via restriction of a space of events within a learning-specific action model. This way of learning closely resembles the well-known update method from dynamic epistemic logic. We introduce several different learning......In dynamic epistemic logic, actions are described using action models. In this paper we introduce a framework for studying learnability of action models from observations. We present first results concerning propositional action models. First we check two basic learnability criteria: finite...... identifiability (conclusively inferring the appropriate action model in finite time) and identifiability in the limit (inconclusive convergence to the right action model). We show that deterministic actions are finitely identifiable, while non-deterministic actions require more learning power...

  3. Geometrical approach to fluid models

    NARCIS (Netherlands)

    Kuvshinov, B. N.; Schep, T. J.

    1997-01-01

    Differential geometry based upon the Cartan calculus of differential forms is applied to investigate invariant properties of equations that describe the motion of continuous media. The main feature of this approach is that physical quantities are treated as geometrical objects. The geometrical

  4. Geometrical approach to fluid models

    NARCIS (Netherlands)

    Kuvshinov, B. N.; Schep, T. J.

    1997-01-01

    Differential geometry based upon the Cartan calculus of differential forms is applied to investigate invariant properties of equations that describe the motion of continuous media. The main feature of this approach is that physical quantities are treated as geometrical objects. The geometrical notio

  5. Model based feature fusion approach

    NARCIS (Netherlands)

    Schwering, P.B.W.

    2001-01-01

    In recent years different sensor data fusion approaches have been analyzed and evaluated in the field of mine detection. In various studies comparisons have been made between different techniques. Although claims can be made for advantages for using certain techniques, until now there has been no si

  6. Global energy modeling - A biophysical approach

    Energy Technology Data Exchange (ETDEWEB)

    Dale, Michael

    2010-09-15

    This paper contrasts the standard economic approach to energy modelling with energy models using a biophysical approach. Neither of these approaches includes changing energy-returns-on-investment (EROI) due to declining resource quality or the capital intensive nature of renewable energy sources. Both of these factors will become increasingly important in the future. An extension to the biophysical approach is outlined which encompasses a dynamic EROI function that explicitly incorporates technological learning. The model is used to explore several scenarios of long-term future energy supply especially concerning the global transition to renewable energy sources in the quest for a sustainable energy system.

  7. A POMDP approach to Affective Dialogue Modeling

    NARCIS (Netherlands)

    Bui Huu Trung, B.H.T.; Poel, Mannes; Nijholt, Antinus; Zwiers, Jakob; Keller, E.; Marinaro, M.; Bratanic, M.

    2007-01-01

    We propose a novel approach to developing a dialogue model that is able to take into account some aspects of the user's affective state and to act appropriately. Our dialogue model uses a Partially Observable Markov Decision Process approach with observations composed of the observed user's

  8. The chronic diseases modelling approach

    NARCIS (Netherlands)

    Hoogenveen RT; Hollander AEM de; Genugten MLL van; CCM

    1998-01-01

    A mathematical model structure is described that can be used to simulate the changes of the Dutch public health state over time. The model is based on the concept of demographic and epidemiologic processes (events) and is mathematically based on the lifetable method. The population is divided over s

  9. A forward modeling approach for interpreting impeller flow logs.

    Science.gov (United States)

    Parker, Alison H; West, L Jared; Odling, Noelle E; Bown, Richard T

    2010-01-01

    A rigorous and practical approach for interpretation of impeller flow log data to determine vertical variations in hydraulic conductivity is presented and applied to two well logs from a Chalk aquifer in England. Impeller flow logging involves measuring vertical flow speed in a pumped well and using changes in flow with depth to infer the locations and magnitudes of inflows into the well. However, the measured flow logs are typically noisy, which leads to spurious hydraulic conductivity values where simplistic interpretation approaches are applied. In this study, a new method for interpretation is presented, which first defines a series of physical models for hydraulic conductivity variation with depth and then fits the models to the data, using a regression technique. Some of the models will be rejected as they are physically unrealistic. The best model is then selected from the remaining models using a maximum likelihood approach. This balances model complexity against fit, for example, using Akaike's Information Criterion.

  10. An Adaptive Approach to Schema Classification for Data Warehouse Modeling

    Institute of Scientific and Technical Information of China (English)

    Hong-Ding Wang; Yun-Hai Tong; Shao-Hua Tan; Shi-Wei Tang; Dong-Qing Yang; Guo-Hui Sun

    2007-01-01

    Data warehouse (DW) modeling is a complicated task, involving both knowledge of business processes and familiarity with operational information systems structure and behavior. Existing DW modeling techniques suffer from the following major drawbacks -data-driven approach requires high levels of expertise and neglects the requirements of end users, while demand-driven approach lacks enterprise-wide vision and is regardless of existing models of underlying operational systems. In order to make up for those shortcomings, a method of classification of schema elements for DW modeling is proposed in this paper. We first put forward the vector space models for subjects and schema elements, then present an adaptive approach with self-tuning theory to construct context vectors of subjects, and finally classify the source schema elements into different subjects of the DW automatically. Benefited from the result of the schema elements classification, designers can model and construct a DW more easily.

  11. Learning Actions Models: Qualitative Approach

    DEFF Research Database (Denmark)

    Bolander, Thomas; Gierasimczuk, Nina

    2015-01-01

    identifiability (conclusively inferring the appropriate action model in finite time) and identifiability in the limit (inconclusive convergence to the right action model). We show that deterministic actions are finitely identifiable, while non-deterministic actions require more learning power......—they are identifiable in the limit.We then move on to a particular learning method, which proceeds via restriction of a space of events within a learning-specific action model. This way of learning closely resembles the well-known update method from dynamic epistemic logic. We introduce several different learning...

  12. A Unified Approach to Modeling and Programming

    DEFF Research Database (Denmark)

    Madsen, Ole Lehrmann; Møller-Pedersen, Birger

    2010-01-01

    of this paper is to go back to the future and get inspiration from SIMULA and propose a unied approach. In addition to reintroducing the contributions of SIMULA and the Scandinavian approach to object-oriented programming, we do this by discussing a number of issues in modeling and programming and argue3 why we......SIMULA was a language for modeling and programming and provided a unied approach to modeling and programming in contrast to methodologies based on structured analysis and design. The current development seems to be going in the direction of separation of modeling and programming. The goal...

  13. Selection Model of Optional Parts in Suppliers Involved in New Product Development

    Institute of Scientific and Technical Information of China (English)

    MU Lifeng; TANG Jiafu; PAN Zhendong; HAN Yi

    2006-01-01

    Quality function deployment (QFD), which can translate efficiently customer requirement (CRs) into technical attributes (TAs), is widely used in new product development (NPD) as an efficient customer-driven approach. After lots of QFD application is applied in manufacturing fields, it was proved that without considering suppliers involved, it is difficult to get precise and satisfying results in each process of QFD, particularly part deployment. The paper will address the issues of a model of optional parts selection in suppliers involved in part deployment process. Further, it has been applied to an ERP system reconstruction and updating problem as an illustration.

  14. Szekeres models: a covariant approach

    CERN Document Server

    Apostolopoulos, Pantelis S

    2016-01-01

    We exploit the 1+1+2 formalism to covariantly describe the inhomogeneous and anisotropic Szekeres models. It is shown that an \\emph{average scale length} can be defined \\emph{covariantly} which satisfies a 2d equation of motion driven from the \\emph{effective gravitational mass} (EGM) contained in the dust cloud. The contributions to the EGM are encoded to the energy density of the dust fluid and the free gravitational field $E_{ab}$. In addition the notions of the Apparent and Absolute Apparent Horizons are briefly discussed and we give an alternative gauge-invariant form to define them in terms of the kinematical variables of the spacelike congruences. We argue that the proposed program can be used in order to express the Sachs optical equations in a covariant form and analyze the confrontation of a spatially inhomogeneous irrotational overdense fluid model with the observational data.

  15. Matrix Model Approach to Cosmology

    CERN Document Server

    Chaney, A; Stern, A

    2015-01-01

    We perform a systematic search for rotationally invariant cosmological solutions to matrix models, or more specifically the bosonic sector of Lorentzian IKKT-type matrix models, in dimensions $d$ less than ten, specifically $d=3$ and $d=5$. After taking a continuum (or commutative) limit they yield $d-1$ dimensional space-time surfaces, with an attached Poisson structure, which can be associated with closed, open or static cosmologies. For $d=3$, we obtain recursion relations from which it is possible to generate rotationally invariant matrix solutions which yield open universes in the continuum limit. Specific examples of matrix solutions have also been found which are associated with closed and static two-dimensional space-times in the continuum limit. The solutions provide for a matrix resolution of cosmological singularities. The commutative limit reveals other desirable features, such as a solution describing a smooth transition from an initial inflation to a noninflationary era. Many of the $d=3$ soluti...

  16. A new approach to adaptive data models

    Directory of Open Access Journals (Sweden)

    Ion LUNGU

    2016-12-01

    Full Text Available Over the last decade, there has been a substantial increase in the volume and complexity of data we collect, store and process. We are now aware of the increasing demand for real time data processing in every continuous business process that evolves within the organization. We witness a shift from a traditional static data approach to a more adaptive model approach. This article aims to extend understanding in the field of data models used in information systems by examining how an adaptive data model approach for managing business processes can help organizations accommodate on the fly and build dynamic capabilities to react in a dynamic environment.

  17. The endoscopic endonasal approach for the management of craniopharyngiomas involving the third ventricle.

    Science.gov (United States)

    Cavallo, Luigi Maria; Solari, Domenico; Esposito, Felice; Cappabianca, Paolo

    2013-01-01

    The third ventricle has historically represented one of the most challenging areas to access surgically, so that lesions directly harboring into the ventricular chamber or secondarily extending into it from adjacent areas have been approached by means of different transcranial routes. The aim of this work is to report our experience with the endoscopic endonasal approach in the management of a series of patients affected by craniopharyngiomas, extending into or arising from the third ventricle, evaluating pros and cons of this technique, also in regards of the anatomy and the pathology dealt with. During the period between January 2001 and February 2011, 12 patients, 9 male and 3 female (mean age 50.4 years; range 12-68) underwent an endoscopic endonasal approach for the treatment of a craniopharyngioma involving or arising from the third ventricle. According to the grade of involvement of the third ventricle, we identified three main ventricular growth patterns: (1) stalk-infundibulum; (2) infundibulum-ventricular chamber; (3) stalk-infundibulum-ventricular chamber. Though gross total removal was achieved in eight patients (66.7%), in three patients (25%) was possible a near total removal (>95%) and only in one case (8.3%) tumor removal has been partial (endonasal route provides a good exposure, especially of the sub- and retro-chiasmatic areas, as well as of the stalk-infundibulum axis, which represents, when directly involved by a lesion, a gate to access the third ventricle chamber. Despite this study reporting only a preliminary experience, it seems that in properly selected cases--namely tumors growing mostly along the pituitary stem-infundibulum-third ventricle axis--this approach could be advocated as a valid route among the wide kaleidoscope of surgical approaches to the third ventricle.

  18. Modeling software behavior a craftsman's approach

    CERN Document Server

    Jorgensen, Paul C

    2009-01-01

    A common problem with most texts on requirements specifications is that they emphasize structural models to the near exclusion of behavioral models-focusing on what the software is, rather than what it does. If they do cover behavioral models, the coverage is brief and usually focused on a single model. Modeling Software Behavior: A Craftsman's Approach provides detailed treatment of various models of software behavior that support early analysis, comprehension, and model-based testing. Based on the popular and continually evolving course on requirements specification models taught by the auth

  19. Sleeping Beauty mouse models identify candidate genes involved in gliomagenesis.

    Science.gov (United States)

    Vyazunova, Irina; Maklakova, Vilena I; Berman, Samuel; De, Ishani; Steffen, Megan D; Hong, Won; Lincoln, Hayley; Morrissy, A Sorana; Taylor, Michael D; Akagi, Keiko; Brennan, Cameron W; Rodriguez, Fausto J; Collier, Lara S

    2014-01-01

    Genomic studies of human high-grade gliomas have discovered known and candidate tumor drivers. Studies in both cell culture and mouse models have complemented these approaches and have identified additional genes and processes important for gliomagenesis. Previously, we found that mobilization of Sleeping Beauty transposons in mice ubiquitously throughout the body from the Rosa26 locus led to gliomagenesis with low penetrance. Here we report the characterization of mice in which transposons are mobilized in the Glial Fibrillary Acidic Protein (GFAP) compartment. Glioma formation in these mice did not occur on an otherwise wild-type genetic background, but rare gliomas were observed when mobilization occurred in a p19Arf heterozygous background. Through cloning insertions from additional gliomas generated by transposon mobilization in the Rosa26 compartment, several candidate glioma genes were identified. Comparisons to genetic, epigenetic and mRNA expression data from human gliomas implicates several of these genes as tumor suppressor genes and oncogenes in human glioblastoma.

  20. Current approaches to gene regulatory network modelling

    Directory of Open Access Journals (Sweden)

    Brazma Alvis

    2007-09-01

    Full Text Available Abstract Many different approaches have been developed to model and simulate gene regulatory networks. We proposed the following categories for gene regulatory network models: network parts lists, network topology models, network control logic models, and dynamic models. Here we will describe some examples for each of these categories. We will study the topology of gene regulatory networks in yeast in more detail, comparing a direct network derived from transcription factor binding data and an indirect network derived from genome-wide expression data in mutants. Regarding the network dynamics we briefly describe discrete and continuous approaches to network modelling, then describe a hybrid model called Finite State Linear Model and demonstrate that some simple network dynamics can be simulated in this model.

  1. Model Oriented Approach for Industrial Software Development

    Directory of Open Access Journals (Sweden)

    P. D. Drobintsev

    2015-01-01

    Full Text Available The article considers the specifics of a model oriented approach to software development based on the usage of Model Driven Architecture (MDA, Model Driven Software Development (MDSD and Model Driven Development (MDD technologies. Benefits of this approach usage in the software development industry are described. The main emphasis is put on the system design, automated code generation for large systems, verification, proof of system properties and reduction of bug density. Drawbacks of the approach are also considered. The approach proposed in the article is specific for industrial software systems development. These systems are characterized by different levels of abstraction, which is used on modeling and code development phases. The approach allows to detail the model to the level of the system code, at the same time store the verified model semantics and provide the checking of the whole detailed model. Steps of translating abstract data structures (including transactions, signals and their parameters into data structures used in detailed system implementation are presented. Also the grammar of a language for specifying rules of abstract model data structures transformation into real system detailed data structures is described. The results of applying the proposed method in the industrial technology are shown.The article is published in the authors’ wording.

  2. MODIFIED TRANSCRANIAL APPROACH FOR RESECTION OF TUMORS INVOLVING THE ANTERIOR CRANIAL FOSSA

    Institute of Scientific and Technical Information of China (English)

    赵素萍; 陶正德; 肖健云

    2001-01-01

    Objective: To introduce the method of a modified transcranial approach for resection of paranasal sinuses tumors involving the anterior skull base and to address our experience with the approach. Patients and Methods: Ten cases were operated by the approach. Among them, 4 suffered from benign meningeomas, 6 with malignant tumors included one chondrosarcoma, two malignant meningeomas, two olfactory neuroblastomas, and one squamous sarcoma. Of the patients, 4 cases had primary tumor and 6 cases had recurrent tumors. Result: All of the ten cases underwent operation and no postopertion complication occurred. 7 cases have survived for one to four years without tumor recurrence. 3 cases with malignant tumor died of tumor relapse in one to two years. Conclusion: This method significantly has helped to reduce the persistence and recurrence of the disease.

  3. Distributed simulation a model driven engineering approach

    CERN Document Server

    Topçu, Okan; Oğuztüzün, Halit; Yilmaz, Levent

    2016-01-01

    Backed by substantive case studies, the novel approach to software engineering for distributed simulation outlined in this text demonstrates the potent synergies between model-driven techniques, simulation, intelligent agents, and computer systems development.

  4. From Zinnia to Arabidopsis: approaching the involvement of peroxidases in lignification.

    Science.gov (United States)

    Novo-Uzal, Esther; Fernández-Pérez, Francisco; Herrero, Joaquín; Gutiérrez, Jorge; Gómez-Ros, Laura V; Bernal, María Ángeles; Díaz, José; Cuello, Juan; Pomar, Federico; Pedreño, María Ángeles

    2013-09-01

    Zinnia elegans constitutes one of the most useful model systems for studying xylem differentiation, which simultaneously involves secondary cell wall synthesis, cell wall lignification, and programmed cell death. Likewise, the in vitro culture system of Z. elegans has been the best characterized as the differentiation of mesophyll cells into tracheary elements allows study of the biochemistry and physiology of xylogenesis free from the complexity that heterogeneous plant tissues impose. Moreover, Z. elegans has emerged as an excellent plant model to study the involvement of peroxidases in cell wall lignification. This is due to the simplicity and duality of the lignification pattern shown by the stems and hypocotyls, and to the basic nature of the peroxidase isoenzyme. This protein is expressed not only in hypocotyls and stems but also in mesophyll cells transdifferentiating into tracheary elements. Therefore, not only does this peroxidase fulfil all the catalytic requirements to be involved in lignification overcoming all restrictions imposed by the polymerization step, but also its expression is inherent in lignification. In fact, its basic nature is not exceptional since basic peroxidases are differentially expressed during lignification in other model systems, showing unusual and unique biochemical properties such as oxidation of syringyl moieties. This review focuses on the experiments which led to a better understanding of the lignification process in Zinnia, starting with the basic knowledge about the lignin pattern in this plant, how lignification takes place, and how a sole basic peroxidase with unusual catalytic properties is involved and regulated by hormones, H2O2, and nitric oxide.

  5. Evaluation of vehicle damage involved in road crashes based on quantificated model

    Institute of Scientific and Technical Information of China (English)

    FAN Yan-hui; XU Hong-guo; JIANG Hua-ping

    2008-01-01

    Based on economics theory, social value loss caused by vehicle involved in crashes as well as various factors influencing on it were analyzed, the corresponding micro-econometrics model was theoretically given. Moreover, the practicability of the model,the veracity and rationality of quantification were analyzed. Based on probability theory and mathematical statistical theory, macro approach to evaluating vehicle damage in crashes was presented, and the corresponding macro-econometrics model was constructed. In addition, the macro-econometrics model was utilized to assess economic loss from statistical data of vehicle damaged in crashes, which has shown that the model can meet the demand of quantification analysis of vehicle damage, and be applied to the evaluation of economic loss caused by crashes. The results in this paper will be of practical significance for scientific, comprehensive and rational evaluating socio-economic loss caused by road crashes.

  6. A participatory modelling approach to developing a numerical sediment dynamics model

    Science.gov (United States)

    Jones, Nicholas; McEwen, Lindsey; Parker, Chris; Staddon, Chad

    2016-04-01

    Fluvial geomorphology is recognised as an important consideration in policy and legislation in the management of river catchments. Despite this recognition, limited knowledge exchange occurs between scientific researchers and river management practitioners. An example of this can be found within the limited uptake of numerical models of sediment dynamics by river management practitioners in the United Kingdom. The uptake of these models amongst the applied community is important as they have the potential to articulate how, at the catchment-scale, the impacts of management strategies of land-use change affect sediment dynamics and resulting channel quality. This paper describes and evaluates a new approach which involves river management stakeholders in an iterative and reflexive participatory modelling process. The aim of this approach was to create an environment for knowledge exchange between the stakeholders and the research team in the process of co-constructing a model. This process adopted a multiple case study approach, involving four groups of river catchment stakeholders in the United Kingdom. These stakeholder groups were involved in several stages of the participatory modelling process including: requirements analysis, model design, model development, and model evaluation. Stakeholders have provided input into a number of aspects of the modelling process, such as: data requirements, user interface, modelled processes, model assumptions, model applications, and model outputs. This paper will reflect on this process, in particular: the innovative methods used, data generated, and lessons learnt.

  7. A Set Theoretical Approach to Maturity Models

    DEFF Research Database (Denmark)

    Lasrado, Lester; Vatrapu, Ravi; Andersen, Kim Normann

    2016-01-01

    Maturity Model research in IS has been criticized for the lack of theoretical grounding, methodological rigor, empirical validations, and ignorance of multiple and non-linear paths to maturity. To address these criticisms, this paper proposes a novel set-theoretical approach to maturity models ch...

  8. Sleeping Beauty mouse models identify candidate genes involved in gliomagenesis.

    Directory of Open Access Journals (Sweden)

    Irina Vyazunova

    Full Text Available Genomic studies of human high-grade gliomas have discovered known and candidate tumor drivers. Studies in both cell culture and mouse models have complemented these approaches and have identified additional genes and processes important for gliomagenesis. Previously, we found that mobilization of Sleeping Beauty transposons in mice ubiquitously throughout the body from the Rosa26 locus led to gliomagenesis with low penetrance. Here we report the characterization of mice in which transposons are mobilized in the Glial Fibrillary Acidic Protein (GFAP compartment. Glioma formation in these mice did not occur on an otherwise wild-type genetic background, but rare gliomas were observed when mobilization occurred in a p19Arf heterozygous background. Through cloning insertions from additional gliomas generated by transposon mobilization in the Rosa26 compartment, several candidate glioma genes were identified. Comparisons to genetic, epigenetic and mRNA expression data from human gliomas implicates several of these genes as tumor suppressor genes and oncogenes in human glioblastoma.

  9. Sleeping Beauty Mouse Models Identify Candidate Genes Involved in Gliomagenesis

    Science.gov (United States)

    Vyazunova, Irina; Maklakova, Vilena I.; Berman, Samuel; De, Ishani; Steffen, Megan D.; Hong, Won; Lincoln, Hayley; Morrissy, A. Sorana; Taylor, Michael D.; Akagi, Keiko; Brennan, Cameron W.; Rodriguez, Fausto J.; Collier, Lara S.

    2014-01-01

    Genomic studies of human high-grade gliomas have discovered known and candidate tumor drivers. Studies in both cell culture and mouse models have complemented these approaches and have identified additional genes and processes important for gliomagenesis. Previously, we found that mobilization of Sleeping Beauty transposons in mice ubiquitously throughout the body from the Rosa26 locus led to gliomagenesis with low penetrance. Here we report the characterization of mice in which transposons are mobilized in the Glial Fibrillary Acidic Protein (GFAP) compartment. Glioma formation in these mice did not occur on an otherwise wild-type genetic background, but rare gliomas were observed when mobilization occurred in a p19Arf heterozygous background. Through cloning insertions from additional gliomas generated by transposon mobilization in the Rosa26 compartment, several candidate glioma genes were identified. Comparisons to genetic, epigenetic and mRNA expression data from human gliomas implicates several of these genes as tumor suppressor genes and oncogenes in human glioblastoma. PMID:25423036

  10. Probabilistic Fuzzy Goal Programming Problems Involving Pareto Distribution: Some Additive Approaches

    Directory of Open Access Journals (Sweden)

    S.K. Barik

    2015-06-01

    Full Text Available In many real-life decision making problems, probabilistic fuzzy goal programming problems are used where some of the input parameters of the problem are considered as random variables with fuzzy aspiration levels. In the present paper, a linearly constrained probabilistic fuzzy goal programming programming problem is presented where the right hand side parameters in some constraints follows Pareto distribution with known mean and variance. Also the aspiration levels are considered as fuzzy. Further, simple, weighted, and preemptive additive approaches are discussed for probabilistic fuzzy goal programming model. These additive approaches are employed to aggregating the membership values and form crisp equivalent deterministic models. The resulting models are then solved by using standard linear mathematical programming techniques. The developed methodology and solution procedures are illustrated with a numerical example.

  11. Modeling diffuse pollution with a distributed approach.

    Science.gov (United States)

    León, L F; Soulis, E D; Kouwen, N; Farquhar, G J

    2002-01-01

    The transferability of parameters for non-point source pollution models to other watersheds, especially those in remote areas without enough data for calibration, is a major problem in diffuse pollution modeling. A water quality component was developed for WATFLOOD (a flood forecast hydrological model) to deal with sediment and nutrient transport. The model uses a distributed group response unit approach for water quantity and quality modeling. Runoff, sediment yield and soluble nutrient concentrations are calculated separately for each land cover class, weighted by area and then routed downstream. The distributed approach for the water quality model for diffuse pollution in agricultural watersheds is described in this paper. Integrating the model with data extracted using GIS technology (Geographical Information Systems) for a local watershed, the model is calibrated for the hydrologic response and validated for the water quality component. With the connection to GIS and the group response unit approach used in this paper, model portability increases substantially, which will improve non-point source modeling at the watershed scale level.

  12. MODULAR APPROACH WITH ROUGH DECISION MODELS

    Directory of Open Access Journals (Sweden)

    Ahmed T. Shawky

    2012-09-01

    Full Text Available Decision models which adopt rough set theory have been used effectively in many real world applications.However, rough decision models suffer the high computational complexity when dealing with datasets ofhuge size. In this research we propose a new rough decision model that allows making decisions based onmodularity mechanism. According to the proposed approach, large-size datasets can be divided intoarbitrary moderate-size datasets, then a group of rough decision models can be built as separate decisionmodules. The overall model decision is computed as the consensus decision of all decision modulesthrough some aggregation technique. This approach provides a flexible and a quick way for extractingdecision rules of large size information tables using rough decision models.

  13. Modular Approach with Rough Decision Models

    Directory of Open Access Journals (Sweden)

    Ahmed T. Shawky

    2012-10-01

    Full Text Available Decision models which adopt rough set theory have been used effectively in many real world applications.However, rough decision models suffer the high computational complexity when dealing with datasets ofhuge size. In this research we propose a new rough decision model that allows making decisions based onmodularity mechanism. According to the proposed approach, large-size datasets can be divided intoarbitrary moderate-size datasets, then a group of rough decision models can be built as separate decisionmodules. The overall model decision is computed as the consensus decision of all decision modulesthrough some aggregation technique. This approach provides a flexible and a quick way for extractingdecision rules of large size information tables using rough decision models.

  14. Modeling approach suitable for energy system

    Energy Technology Data Exchange (ETDEWEB)

    Goetschel, D. V.

    1979-01-01

    Recently increased attention has been placed on optimization problems related to the determination and analysis of operating strategies for energy systems. Presented in this paper is a nonlinear model that can be used in the formulation of certain energy-conversion systems-modeling problems. The model lends itself nicely to solution approaches based on nonlinear-programming algorithms and, in particular, to those methods falling into the class of variable metric algorithms for nonlinearly constrained optimization.

  15. Building Water Models, A Different Approach

    CERN Document Server

    Izadi, Saeed; Onufriev, Alexey V

    2014-01-01

    Simplified, classical models of water are an integral part of atomistic molecular simulations, especially in biology and chemistry where hydration effects are critical. Yet, despite several decades of effort, these models are still far from perfect. Presented here is an alternative approach to constructing point charge water models - currently, the most commonly used type. In contrast to the conventional approach, we do not impose any geometry constraints on the model other than symmetry. Instead, we optimize the distribution of point charges to best describe the "electrostatics" of the water molecule, which is key to many unusual properties of liquid water. The search for the optimal charge distribution is performed in 2D parameter space of key lowest multipole moments of the model, to find best fit to a small set of bulk water properties at room temperature. A virtually exhaustive search is enabled via analytical equations that relate the charge distribution to the multipole moments. The resulting "optimal"...

  16. Effectiveness of Peer Education Involving the use of Theoretical Models

    OpenAIRE

    2008-01-01

    The effectiveness of health education among university students who received peer-support training was investigated using four theoretical models : the health belief model, the self-efficacy model, social support and the transtheoretical model of health behavior change. Results suggested that the four theoretical models were useful in evaluating the effect of peer education as an alternative assessment tool. In light of this, it is suggested that the use of the theoretical models may facilita...

  17. Involving people with learning disabilities in nurse education: towards an inclusive approach.

    Science.gov (United States)

    Bollard, Martin; Lahiff, John; Parkes, Neville

    2012-02-01

    There is limited evidence that explores how to effectively include people with learning disabilities in nurse education in the U.K. The majority of reported work relates to mental health nursing and social work training (Morgan and Jones, 2009). This paper specifically reports on the processes and activities undertaken by the authors with people with learning disabilities in the development of a new BSc learning disability nursing programme, a specific branch of nursing in the U.K. In doing so, findings and discussion from two separate projects involving students and people with learning disabilities will be integrated into the paper. EPICURE (Engagement, Processing, Interpretation, Critique, Usefulness, Relevance and Ethics (Stige et al. 2009) is adopted as a qualitative framework throughout the paper to evaluate the reported work that took place between September 2006 and October 2010. Suggestions are therefore made regarding the benefits and challenges of striving towards an inclusive approach to user involvement in nurse education, with particular reference to learning disability. The work presented in the paper demonstrates how through careful involvement of this population, deeper learning opportunities for all nursing students can be created.

  18. An integrated approach to consumer representation and involvement in a multicentre randomized controlled trial.

    Science.gov (United States)

    Langston, Anne L; McCallum, Marilyn; Campbell, Marion K; Robertson, Clare; Ralston, Stuart H

    2005-01-01

    Although, consumer involvement in individual studies is often limited, their involvement in guiding health research is generally considered to be beneficial. This paper outlines our experiences of an integrated relationship between the organisers of a clinical trial and a consumer organisation. The PRISM trial is a UK multicentre, randomized controlled trial comparing treatment strategies for Paget's disease of the bone. The National Association for the Relief of Paget's Disease (NARPD) is the only UK support group for sufferers of Paget's disease and has worked closely with the PRISM team from the outset. NARPD involvement is integral to the conduct of the trial and specific roles have included: peer-review; trial steering committee membership; provision of advice to participants, and promotion of the trial amongst Paget's disease patients. The integrated relationship has yielded benefits to both the trial and the consumer organisation. The benefits for the trial have included: recruitment of participants via NARPD contacts; well-informed participants; unsolicited patient advocacy of the trial; and interested and pro-active collaborators. For the NARPD and Paget's disease sufferers, benefits have included: increased awareness of Paget's disease; increased access to relevant health research; increased awareness of the NARPD services; and wider transfer of diagnosis and management knowledge to/from health care professionals. Our experience has shown that an integrated approach between a trial team and a consumer organisation is worthwhile. Adoption of such an approach in other trials may yield significant improvements in recruitment and quality of participant information flow. There are, however, resource implications for both parties.

  19. Towards new approaches in phenological modelling

    Science.gov (United States)

    Chmielewski, Frank-M.; Götz, Klaus-P.; Rawel, Harshard M.; Homann, Thomas

    2014-05-01

    Modelling of phenological stages is based on temperature sums for many decades, describing both the chilling and the forcing requirement of woody plants until the beginning of leafing or flowering. Parts of this approach go back to Reaumur (1735), who originally proposed the concept of growing degree-days. Now, there is a growing body of opinion that asks for new methods in phenological modelling and more in-depth studies on dormancy release of woody plants. This requirement is easily understandable if we consider the wide application of phenological models, which can even affect the results of climate models. To this day, in phenological models still a number of parameters need to be optimised on observations, although some basic physiological knowledge of the chilling and forcing requirement of plants is already considered in these approaches (semi-mechanistic models). Limiting, for a fundamental improvement of these models, is the lack of knowledge about the course of dormancy in woody plants, which cannot be directly observed and which is also insufficiently described in the literature. Modern metabolomic methods provide a solution for this problem and allow both, the validation of currently used phenological models as well as the development of mechanistic approaches. In order to develop this kind of models, changes of metabolites (concentration, temporal course) must be set in relation to the variability of environmental (steering) parameters (weather, day length, etc.). This necessarily requires multi-year (3-5 yr.) and high-resolution (weekly probes between autumn and spring) data. The feasibility of this approach has already been tested in a 3-year pilot-study on sweet cherries. Our suggested methodology is not only limited to the flowering of fruit trees, it can be also applied to tree species of the natural vegetation, where even greater deficits in phenological modelling exist.

  20. Boolean Modeling of Cellular and Molecular Pathways Involved in Influenza Infection

    Science.gov (United States)

    Anderson, Christopher S.; DeDiego, Marta L.; Topham, David J.; Thakar, Juilee

    2016-01-01

    Systems virology integrates host-directed approaches with molecular profiling to understand viral pathogenesis. Self-contained statistical approaches that combine expression profiles of genes with the available databases defining the genes involved in the pathways (gene-sets) have allowed characterization of predictive gene-signatures associated with outcome of the influenza virus (IV) infection. However, such enrichment techniques do not take into account interactions among pathways that are responsible for the IV infection pathogenesis. We investigate dendritic cell response to seasonal H1N1 influenza A/New Caledonia/20/1999 (NC) infection and infer the Boolean logic rules underlying the interaction network of ligand induced signaling pathways and transcription factors. The model reveals several novel regulatory modes and provides insights into mechanism of cross talk between NFκB and IRF mediated signaling. Additionally, the logic rule underlying the regulation of IL2 pathway that was predicted by the Boolean model was experimentally validated. Thus, the model developed in this paper integrates pathway analysis tools with the dynamic modeling approaches to reveal the regulation between signaling pathways and transcription factors using genome-wide transcriptional profiles measured upon influenza infection. PMID:26981147

  1. Boolean Modeling of Cellular and Molecular Pathways Involved in Influenza Infection

    Directory of Open Access Journals (Sweden)

    Christopher S. Anderson

    2016-01-01

    Full Text Available Systems virology integrates host-directed approaches with molecular profiling to understand viral pathogenesis. Self-contained statistical approaches that combine expression profiles of genes with the available databases defining the genes involved in the pathways (gene-sets have allowed characterization of predictive gene-signatures associated with outcome of the influenza virus (IV infection. However, such enrichment techniques do not take into account interactions among pathways that are responsible for the IV infection pathogenesis. We investigate dendritic cell response to seasonal H1N1 influenza A/New Caledonia/20/1999 (NC infection and infer the Boolean logic rules underlying the interaction network of ligand induced signaling pathways and transcription factors. The model reveals several novel regulatory modes and provides insights into mechanism of cross talk between NFκB and IRF mediated signaling. Additionally, the logic rule underlying the regulation of IL2 pathway that was predicted by the Boolean model was experimentally validated. Thus, the model developed in this paper integrates pathway analysis tools with the dynamic modeling approaches to reveal the regulation between signaling pathways and transcription factors using genome-wide transcriptional profiles measured upon influenza infection.

  2. Boolean Modeling of Cellular and Molecular Pathways Involved in Influenza Infection.

    Science.gov (United States)

    Anderson, Christopher S; DeDiego, Marta L; Topham, David J; Thakar, Juilee

    2016-01-01

    Systems virology integrates host-directed approaches with molecular profiling to understand viral pathogenesis. Self-contained statistical approaches that combine expression profiles of genes with the available databases defining the genes involved in the pathways (gene-sets) have allowed characterization of predictive gene-signatures associated with outcome of the influenza virus (IV) infection. However, such enrichment techniques do not take into account interactions among pathways that are responsible for the IV infection pathogenesis. We investigate dendritic cell response to seasonal H1N1 influenza A/New Caledonia/20/1999 (NC) infection and infer the Boolean logic rules underlying the interaction network of ligand induced signaling pathways and transcription factors. The model reveals several novel regulatory modes and provides insights into mechanism of cross talk between NFκB and IRF mediated signaling. Additionally, the logic rule underlying the regulation of IL2 pathway that was predicted by the Boolean model was experimentally validated. Thus, the model developed in this paper integrates pathway analysis tools with the dynamic modeling approaches to reveal the regulation between signaling pathways and transcription factors using genome-wide transcriptional profiles measured upon influenza infection.

  3. Building enterprise reuse program--A model-based approach

    Institute of Scientific and Technical Information of China (English)

    梅宏; 杨芙清

    2002-01-01

    Reuse is viewed as a realistically effective approach to solving software crisis. For an organization that wants to build a reuse program, technical and non-technical issues must be considered in parallel. In this paper, a model-based approach to building systematic reuse program is presented. Component-based reuse is currently a dominant approach to software reuse. In this approach, building the right reusable component model is the first important step. In order to achieve systematic reuse, a set of component models should be built from different perspectives. Each of these models will give a specific view of the components so as to satisfy different needs of different persons involved in the enterprise reuse program. There already exist some component models for reuse from technical perspectives. But less attention is paid to the reusable components from a non-technical view, especially from the view of process and management. In our approach, a reusable component model--FLP model for reusable component--is introduced. This model describes components from three dimensions (Form, Level, and Presentation) and views components and their relationships from the perspective of process and management. It determines the sphere of reusable components, the time points of reusing components in the development process, and the needed means to present components in terms of the abstraction level, logic granularity and presentation media. Being the basis on which the management and technical decisions are made, our model will be used as the kernel model to initialize and normalize a systematic enterprise reuse program.

  4. Modelling Coagulation Systems: A Stochastic Approach

    CERN Document Server

    Ryazanov, V V

    2011-01-01

    A general stochastic approach to the description of coagulating aerosol system is developed. As the object of description one can consider arbitrary mesoscopic values (number of aerosol clusters, their size etc). The birth-and-death formalism for a number of clusters can be regarded as a partial case of the generalized storage model. An application of the storage model to the number of monomers in a cluster is discussed.

  5. A Multiple Model Approach to Modeling Based on LPF Algorithm

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Input-output data fitting methods are often used for unknown-structure nonlinear system modeling. Based on model-on-demand tactics, a multiple model approach to modeling for nonlinear systems is presented. The basic idea is to find out, from vast historical system input-output data sets, some data sets matching with the current working point, then to develop a local model using Local Polynomial Fitting (LPF) algorithm. With the change of working points, multiple local models are built, which realize the exact modeling for the global system. By comparing to other methods, the simulation results show good performance for its simple, effective and reliable estimation.``

  6. Model correction factor method for reliability problems involving integrals of non-Gaussian random fields

    DEFF Research Database (Denmark)

    Franchin, P.; Ditlevsen, Ove Dalager; Kiureghian, Armen Der

    2002-01-01

    The model correction factor method (MCFM) is used in conjunction with the first-order reliability method (FORM) to solve structural reliability problems involving integrals of non-Gaussian random fields. The approach replaces the limit-state function with an idealized one, in which the integrals...... are considered to be Gaussian. Conventional FORM analysis yields the linearization point of the idealized limit-state surface. A model correction factor is then introduced to push the idealized limit-state surface onto the actual limit-state surface. A few iterations yield a good approximation of the reliability...... reliability method; Model correction factor method; Nataf field integration; Non-Gaussion random field; Random field integration; Structural reliability; Pile foundation reliability...

  7. A Model Management Approach for Co-Simulation Model Evaluation

    NARCIS (Netherlands)

    Zhang, X.C.; Broenink, Johannes F.; Filipe, Joaquim; Kacprzyk, Janusz; Pina, Nuno

    2011-01-01

    Simulating formal models is a common means for validating the correctness of the system design and reduce the time-to-market. In most of the embedded control system design, multiple engineering disciplines and various domain-specific models are often involved, such as mechanical, control, software

  8. Towards a Multiscale Approach to Cybersecurity Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Hogan, Emilie A.; Hui, Peter SY; Choudhury, Sutanay; Halappanavar, Mahantesh; Oler, Kiri J.; Joslyn, Cliff A.

    2013-11-12

    We propose a multiscale approach to modeling cyber networks, with the goal of capturing a view of the network and overall situational awareness with respect to a few key properties--- connectivity, distance, and centrality--- for a system under an active attack. We focus on theoretical and algorithmic foundations of multiscale graphs, coming from an algorithmic perspective, with the goal of modeling cyber system defense as a specific use case scenario. We first define a notion of \\emph{multiscale} graphs, in contrast with their well-studied single-scale counterparts. We develop multiscale analogs of paths and distance metrics. As a simple, motivating example of a common metric, we present a multiscale analog of the all-pairs shortest-path problem, along with a multiscale analog of a well-known algorithm which solves it. From a cyber defense perspective, this metric might be used to model the distance from an attacker's position in the network to a sensitive machine. In addition, we investigate probabilistic models of connectivity. These models exploit the hierarchy to quantify the likelihood that sensitive targets might be reachable from compromised nodes. We believe that our novel multiscale approach to modeling cyber-physical systems will advance several aspects of cyber defense, specifically allowing for a more efficient and agile approach to defending these systems.

  9. Post-16 Biology--Some Model Approaches?

    Science.gov (United States)

    Lock, Roger

    1997-01-01

    Outlines alternative approaches to the teaching of difficult concepts in A-level biology which may help student learning by making abstract ideas more concrete and accessible. Examples include models, posters, and poems for illustrating meiosis, mitosis, genetic mutations, and protein synthesis. (DDR)

  10. Reflections of a team approach to involving people with dementia in research.

    Science.gov (United States)

    King, Amanda; Hopkinson, Jane; Milton, Rebecca

    2016-01-01

    The article reflects on the ways in which a person-centred approach was used to ensure that people with dementia were given an opportunity to participate in research. The authors discuss three key issues-the importance of including people with dementia in research, informed consent and the possibility of accidental disclosure of diagnosis. The study was an in-depth examination of the ways in which the cancer team manages patients with memory problems and patients with dementia, and the experiences of these patients and their families in accessing outpatient cancer treatment and care in Wales. The study findings will be reported elsewhere. This article aims to add to the small body of existing knowledge within the literature that describes the experiences of researchers in actively involving people with dementia in research.

  11. Decomposition approach to model smart suspension struts

    Science.gov (United States)

    Song, Xubin

    2008-10-01

    Model and simulation study is the starting point for engineering design and development, especially for developing vehicle control systems. This paper presents a methodology to build models for application of smart struts for vehicle suspension control development. The modeling approach is based on decomposition of the testing data. Per the strut functions, the data is dissected according to both control and physical variables. Then the data sets are characterized to represent different aspects of the strut working behaviors. Next different mathematical equations can be built and optimized to best fit the corresponding data sets, respectively. In this way, the model optimization can be facilitated in comparison to a traditional approach to find out a global optimum set of model parameters for a complicated nonlinear model from a series of testing data. Finally, two struts are introduced as examples for this modeling study: magneto-rheological (MR) dampers and compressible fluid (CF) based struts. The model validation shows that this methodology can truly capture macro-behaviors of these struts.

  12. Diagnostic approach to small bowel involvement in inflammatory bowel disease: view of the endoscopist.

    Science.gov (United States)

    Papadakis, Konstantinos A

    2009-01-01

    Recent advances in endoscopic small bowel (SB) techniques have revolutionalized the diagnostic approach of patients with suspected or known inflammatory bowel disease (IBD). Wireless capsule endoscopy (WCE) has become an important diagnostic tool for the evaluation of suspected CD of the SB or in patients with known IBD to rule out SB involvement. The greatest utility of WCE has been observed in cases of suspected CD, where the initial evaluation with traditional radiographic and endoscopic studies has failed to establish the diagnosis. WCE can detect early SB lesions that can be overlooked by traditional radiological studies. The sensitivity of diagnosing SB CD by WCE is superior to other endoscopic or radiological methods such as push enteroscopy, computed tomography or magnetic resonance enteroclysis. The utility of WCE in patients with known CD, IBD unclassified (IBDU) and a select group of patients with ulcerative colitis (UC) can better define the diagnosis and extent of the disease and may lead to reclassification of IBD from UC/IBDU to definitive CD. In addition, previously diagnosed patients with CD may be found to have more significant disease burden in the SB. This information may facilitate more targeted and effective therapies and potentially lead to better patient outcomes. A disadvantage of WCE is its low specificity and the risk of being retained in a strictured area of the SB. Balloon-assisted enteroscopy has essentially replaced push enteroscopy, and has been used to treat CD strictures, obtain biopsies from areas of SB involvement and even retrieving a retained capsule.

  13. Heat transfer modeling an inductive approach

    CERN Document Server

    Sidebotham, George

    2015-01-01

    This innovative text emphasizes a "less-is-more" approach to modeling complicated systems such as heat transfer by treating them first as "1-node lumped models" that yield simple closed-form solutions. The author develops numerical techniques for students to obtain more detail, but also trains them to use the techniques only when simpler approaches fail. Covering all essential methods offered in traditional texts, but with a different order, Professor Sidebotham stresses inductive thinking and problem solving as well as a constructive understanding of modern, computer-based practice. Readers learn to develop their own code in the context of the material, rather than just how to use packaged software, offering a deeper, intrinsic grasp behind models of heat transfer. Developed from over twenty-five years of lecture notes to teach students of mechanical and chemical engineering at The Cooper Union for the Advancement of Science and Art, the book is ideal for students and practitioners across engineering discipl...

  14. Mouse models for genes involved in impaired spermatogenesis.

    Science.gov (United States)

    O'Bryan, M K; de Kretser, D

    2006-02-01

    Since the introduction of molecular biology and gene ablation technologies there have been substantial advances in our understanding of how sperm are made and fertilization occurs. There have been at least 150 different models of specifically altered gene function produced that have resulted in male infertility spanning virtually all aspects of the spermatogenic, sperm maturation and fertilization processes. While each has, or potentially will reveal, novel aspects of these processes, there is still much of which we have little knowledge. The current review is by no means a comprehensive list of these mouse models, rather it gives an overview of the potential for such models which up to this point have generally been 'knockouts'; it presents alternative strategies for the production of new models and emphasizes the importance of thorough phenotypic analysis in order to extract a maximum amount of information from each model.

  15. A Bayesian Shrinkage Approach for AMMI Models.

    Science.gov (United States)

    da Silva, Carlos Pereira; de Oliveira, Luciano Antonio; Nuvunga, Joel Jorge; Pamplona, Andrezza Kéllen Alves; Balestre, Marcio

    2015-01-01

    Linear-bilinear models, especially the additive main effects and multiplicative interaction (AMMI) model, are widely applicable to genotype-by-environment interaction (GEI) studies in plant breeding programs. These models allow a parsimonious modeling of GE interactions, retaining a small number of principal components in the analysis. However, one aspect of the AMMI model that is still debated is the selection criteria for determining the number of multiplicative terms required to describe the GE interaction pattern. Shrinkage estimators have been proposed as selection criteria for the GE interaction components. In this study, a Bayesian approach was combined with the AMMI model with shrinkage estimators for the principal components. A total of 55 maize genotypes were evaluated in nine different environments using a complete blocks design with three replicates. The results show that the traditional Bayesian AMMI model produces low shrinkage of singular values but avoids the usual pitfalls in determining the credible intervals in the biplot. On the other hand, Bayesian shrinkage AMMI models have difficulty with the credible interval for model parameters, but produce stronger shrinkage of the principal components, converging to GE matrices that have more shrinkage than those obtained using mixed models. This characteristic allowed more parsimonious models to be chosen, and resulted in models being selected that were similar to those obtained by the Cornelius F-test (α = 0.05) in traditional AMMI models and cross validation based on leave-one-out. This characteristic allowed more parsimonious models to be chosen and more GEI pattern retained on the first two components. The resulting model chosen by posterior distribution of singular value was also similar to those produced by the cross-validation approach in traditional AMMI models. Our method enables the estimation of credible interval for AMMI biplot plus the choice of AMMI model based on direct posterior

  16. A Bayesian Shrinkage Approach for AMMI Models.

    Directory of Open Access Journals (Sweden)

    Carlos Pereira da Silva

    Full Text Available Linear-bilinear models, especially the additive main effects and multiplicative interaction (AMMI model, are widely applicable to genotype-by-environment interaction (GEI studies in plant breeding programs. These models allow a parsimonious modeling of GE interactions, retaining a small number of principal components in the analysis. However, one aspect of the AMMI model that is still debated is the selection criteria for determining the number of multiplicative terms required to describe the GE interaction pattern. Shrinkage estimators have been proposed as selection criteria for the GE interaction components. In this study, a Bayesian approach was combined with the AMMI model with shrinkage estimators for the principal components. A total of 55 maize genotypes were evaluated in nine different environments using a complete blocks design with three replicates. The results show that the traditional Bayesian AMMI model produces low shrinkage of singular values but avoids the usual pitfalls in determining the credible intervals in the biplot. On the other hand, Bayesian shrinkage AMMI models have difficulty with the credible interval for model parameters, but produce stronger shrinkage of the principal components, converging to GE matrices that have more shrinkage than those obtained using mixed models. This characteristic allowed more parsimonious models to be chosen, and resulted in models being selected that were similar to those obtained by the Cornelius F-test (α = 0.05 in traditional AMMI models and cross validation based on leave-one-out. This characteristic allowed more parsimonious models to be chosen and more GEI pattern retained on the first two components. The resulting model chosen by posterior distribution of singular value was also similar to those produced by the cross-validation approach in traditional AMMI models. Our method enables the estimation of credible interval for AMMI biplot plus the choice of AMMI model based on direct

  17. Pedigree models for complex human traits involving the mitochrondrial genome

    Energy Technology Data Exchange (ETDEWEB)

    Schork, N.J.; Guo, S.W. (Univ. of Michigan, Ann Arbor, MI (United States))

    1993-12-01

    Recent biochemical and molecular-genetic discoveries concerning variations in human mtDNA have suggested a role for mtDNA mutations in a number of human traits and disorders. Although the importance of these discoveries cannot be emphasized enough, the complex natures of mitochondrial biogenesis, mutant mtDNA phenotype expression, and the maternal inheritance pattern exhibited by mtDNA transmission make it difficult to develop models that can be used routinely in pedigree analyses to quantify and test hypotheses about the role of mtDNA in the expression of a trait. In the present paper, the authors describe complexities inherent in mitochondrial biogenesis and genetic transmission and show how these complexities can be incorporated into appropriate mathematical models. The authors offer a variety of likelihood-based models which account for the complexities discussed. The derivation of the models is meant to stimulate the construction of statistical tests for putative mtDNA contribution to a trait. Results of simulation studies which make use of the proposed models are described. The results of the simulation studies suggest that, although pedigree models of mtDNA effects can be reliable, success in mapping chromosomal determinants of a trait does not preclude the possibility that mtDNA determinants exist for the trait as well. Shortcomings inherent in the proposed models are described in an effort to expose areas in need of additional research. 58 refs., 5 figs., 2 tabs.

  18. MULTI MODEL DATA MINING APPROACH FOR HEART FAILURE PREDICTION

    Directory of Open Access Journals (Sweden)

    Priyanka H U

    2016-09-01

    Full Text Available Developing predictive modelling solutions for risk estimation is extremely challenging in health-care informatics. Risk estimation involves integration of heterogeneous clinical sources having different representation from different health-care provider making the task increasingly complex. Such sources are typically voluminous, diverse, and significantly change over the time. Therefore, distributed and parallel computing tools collectively termed big data tools are in need which can synthesize and assist the physician to make right clinical decisions. In this work we propose multi-model predictive architecture, a novel approach for combining the predictive ability of multiple models for better prediction accuracy. We demonstrate the effectiveness and efficiency of the proposed work on data from Framingham Heart study. Results show that the proposed multi-model predictive architecture is able to provide better accuracy than best model approach. By modelling the error of predictive models we are able to choose sub set of models which yields accurate results. More information was modelled into system by multi-level mining which has resulted in enhanced predictive accuracy.

  19. Modeling and Compensatory Processes Underlying Involvement in Child Care among Kibbutz-Reared Fathers

    Science.gov (United States)

    Gaunt, Ruth; Bassi, Liat

    2012-01-01

    This study examined modeling and compensatory processes underlying the effects of an early paternal model on father involvement in child care. Drawing on social learning theory, it was hypothesized that father-son relationships would moderate the association between a father's involvement and his own father's involvement. A sample of 136 kibbutz…

  20. Scientific Theories, Models and the Semantic Approach

    Directory of Open Access Journals (Sweden)

    Décio Krause

    2007-12-01

    Full Text Available According to the semantic view, a theory is characterized by a class of models. In this paper, we examine critically some of the assumptions that underlie this approach. First, we recall that models are models of something. Thus we cannot leave completely aside the axiomatization of the theories under consideration, nor can we ignore the metamathematics used to elaborate these models, for changes in the metamathematics often impose restrictions on the resulting models. Second, based on a parallel between van Fraassen’s modal interpretation of quantum mechanics and Skolem’s relativism regarding set-theoretic concepts, we introduce a distinction between relative and absolute concepts in the context of the models of a scientific theory. And we discuss the significance of that distinction. Finally, by focusing on contemporary particle physics, we raise the question: since there is no general accepted unification of the parts of the standard model (namely, QED and QCD, we have no theory, in the usual sense of the term. This poses a difficulty: if there is no theory, how can we speak of its models? What are the latter models of? We conclude by noting that it is unclear that the semantic view can be applied to contemporary physical theories.

  1. On Heuristic Approach for Solution of Scheduling Problem Involving Transportation Time and Break-down Times for Three Machines

    Directory of Open Access Journals (Sweden)

    A. Khodadadi

    2014-04-01

    Full Text Available In most manufacturing and distribution systems, semi-finished jobs are transferred from one processing facility to another by transporters such as automated guided vehicles and conveyors and finished jobs are delivered to customers or warehouses by vehicles such as trucks. Most machine scheduling models assume either that there are a finite number of transporters for delivering jobs or that jobs are delivered instantaneously from one location to another without transportation time involved. In this study we study a new simple heuristic algorithm for a ‘3-machine, n-job’ flow shop scheduling problem in which transportation time and break down times of machines are considered. A heuristic approach method to find optimal and near optimal sequence minimizing the total elapsed time.

  2. Comparative flood damage model assessment: towards a European approach

    Directory of Open Access Journals (Sweden)

    B. Jongman

    2012-12-01

    Full Text Available There is a wide variety of flood damage models in use internationally, differing substantially in their approaches and economic estimates. Since these models are being used more and more as a basis for investment and planning decisions on an increasingly large scale, there is a need to reduce the uncertainties involved and develop a harmonised European approach, in particular with respect to the EU Flood Risks Directive. In this paper we present a qualitative and quantitative assessment of seven flood damage models, using two case studies of past flood events in Germany and the United Kingdom. The qualitative analysis shows that modelling approaches vary strongly, and that current methodologies for estimating infrastructural damage are not as well developed as methodologies for the estimation of damage to buildings. The quantitative results show that the model outcomes are very sensitive to uncertainty in both vulnerability (i.e. depth–damage functions and exposure (i.e. asset values, whereby the first has a larger effect than the latter. We conclude that care needs to be taken when using aggregated land use data for flood risk assessment, and that it is essential to adjust asset values to the regional economic situation and property characteristics. We call for the development of a flexible but consistent European framework that applies best practice from existing models while providing room for including necessary regional adjustments.

  3. Similarity transformation approach to identifiability analysis of nonlinear compartmental models.

    Science.gov (United States)

    Vajda, S; Godfrey, K R; Rabitz, H

    1989-04-01

    Through use of the local state isomorphism theorem instead of the algebraic equivalence theorem of linear systems theory, the similarity transformation approach is extended to nonlinear models, resulting in finitely verifiable sufficient and necessary conditions for global and local identifiability. The approach requires testing of certain controllability and observability conditions, but in many practical examples these conditions prove very easy to verify. In principle the method also involves nonlinear state variable transformations, but in all of the examples presented in the paper the transformations turn out to be linear. The method is applied to an unidentifiable nonlinear model and a locally identifiable nonlinear model, and these are the first nonlinear models other than bilinear models where the reason for lack of global identifiability is nontrivial. The method is also applied to two models with Michaelis-Menten elimination kinetics, both of considerable importance in pharmacokinetics, and for both of which the complicated nature of the algebraic equations arising from the Taylor series approach has hitherto defeated attempts to establish identifiability results for specific input functions.

  4. Multiscale Model Approach for Magnetization Dynamics Simulations

    CERN Document Server

    De Lucia, Andrea; Tretiakov, Oleg A; Kläui, Mathias

    2016-01-01

    Simulations of magnetization dynamics in a multiscale environment enable rapid evaluation of the Landau-Lifshitz-Gilbert equation in a mesoscopic sample with nanoscopic accuracy in areas where such accuracy is required. We have developed a multiscale magnetization dynamics simulation approach that can be applied to large systems with spin structures that vary locally on small length scales. To implement this, the conventional micromagnetic simulation framework has been expanded to include a multiscale solving routine. The software selectively simulates different regions of a ferromagnetic sample according to the spin structures located within in order to employ a suitable discretization and use either a micromagnetic or an atomistic model. To demonstrate the validity of the multiscale approach, we simulate the spin wave transmission across the regions simulated with the two different models and different discretizations. We find that the interface between the regions is fully transparent for spin waves with f...

  5. Modeling of nonlinear responses for reciprocal transducers involving polarization switching

    DEFF Research Database (Denmark)

    Willatzen, Morten; Wang, Linxiang

    2007-01-01

    Nonlinearities and hysteresis effects in a reciprocal PZT transducer are examined by use of a dynamical mathematical model on the basis of phase-transition theory. In particular, we consider the perovskite piezoelectric ceramic in which the polarization process in the material can be modeled....... We present numerical results for the reciprocal-transducer system and identify the influence of nonlinearities on the system dynamics at high and low frequency as well as electrical impedance effects due to tuning by a series inductance. It is found that nonlinear effects are not important at high...... by Landau theory for the first-order phase transformation, in which each polarization state is associated with a minimum of the Landau free-energy function. Nonlinear constitutive laws are obtained by using thermodynamical equilibrium conditions, and hysteretic behavior of the material can be modeled...

  6. Continuum modeling an approach through practical examples

    CERN Document Server

    Muntean, Adrian

    2015-01-01

    This book develops continuum modeling skills and approaches the topic from three sides: (1) derivation of global integral laws together with the associated local differential equations, (2) design of constitutive laws and (3) modeling boundary processes. The focus of this presentation lies on many practical examples covering aspects such as coupled flow, diffusion and reaction in porous media or microwave heating of a pizza, as well as traffic issues in bacterial colonies and energy harvesting from geothermal wells. The target audience comprises primarily graduate students in pure and applied mathematics as well as working practitioners in engineering who are faced by nonstandard rheological topics like those typically arising in the food industry.

  7. A Multivariate Approach to Functional Neuro Modeling

    DEFF Research Database (Denmark)

    Mørch, Niels J.S.

    1998-01-01

    This Ph.D. thesis, A Multivariate Approach to Functional Neuro Modeling, deals with the analysis and modeling of data from functional neuro imaging experiments. A multivariate dataset description is provided which facilitates efficient representation of typical datasets and, more importantly...... and overall conditions governing the functional experiment, via associated micro- and macroscopic variables. The description facilitates an efficient microscopic re-representation, as well as a handle on the link between brain and behavior; the latter is achieved by hypothesizing variations in the micro...... a generalization theoretical framework centered around measures of model generalization error. - Only few, if any, examples of the application of generalization theory to functional neuro modeling currently exist in the literature. - Exemplification of the proposed generalization theoretical framework...

  8. Interfacial Fluid Mechanics A Mathematical Modeling Approach

    CERN Document Server

    Ajaev, Vladimir S

    2012-01-01

    Interfacial Fluid Mechanics: A Mathematical Modeling Approach provides an introduction to mathematical models of viscous flow used in rapidly developing fields of microfluidics and microscale heat transfer. The basic physical effects are first introduced in the context of simple configurations and their relative importance in typical microscale applications is discussed. Then,several configurations of importance to microfluidics, most notably thin films/droplets on substrates and confined bubbles, are discussed in detail.  Topics from current research on electrokinetic phenomena, liquid flow near structured solid surfaces, evaporation/condensation, and surfactant phenomena are discussed in the later chapters. This book also:  Discusses mathematical models in the context of actual applications such as electrowetting Includes unique material on fluid flow near structured surfaces and phase change phenomena Shows readers how to solve modeling problems related to microscale multiphase flows Interfacial Fluid Me...

  9. Education on electrical phenomena involved in electroporation-based therapies and treatments: a blended learning approach.

    Science.gov (United States)

    Čorović, Selma; Mahnič-Kalamiza, Samo; Miklavčič, Damijan

    2016-04-07

    Electroporation-based applications require multidisciplinary expertise and collaboration of experts with different professional backgrounds in engineering and science. Beginning in 2003, an international scientific workshop and postgraduate course electroporation based technologies and treatments (EBTT) has been organized at the University of Ljubljana to facilitate transfer of knowledge from leading experts to researches, students and newcomers in the field of electroporation. In this paper we present one of the integral parts of EBTT: an e-learning practical work we developed to complement delivery of knowledge via lectures and laboratory work, thus providing a blended learning approach on electrical phenomena involved in electroporation-based therapies and treatments. The learning effect was assessed via a pre- and post e-learning examination test composed of 10 multiple choice questions (i.e. items). The e-learning practical work session and both of the e-learning examination tests were carried out after the live EBTT lectures and other laboratory work. Statistical analysis was performed to compare and evaluate the learning effect measured in two groups of students: (1) electrical engineers and (2) natural scientists (i.e. medical doctors, biologists and chemists) undergoing the e-learning practical work in 2011-2014 academic years. Item analysis was performed to assess the difficulty of each item of the examination test. The results of our study show that the total score on the post examination test significantly improved and the item difficulty in both experimental groups decreased. The natural scientists reached the same level of knowledge (no statistical difference in total post-examination test score) on the post-course test take, as do electrical engineers, although the engineers started with statistically higher total pre-test examination score, as expected. The main objective of this study was to investigate whether the educational content the e

  10. Systematic approach to MIS model creation

    Directory of Open Access Journals (Sweden)

    Macura Perica

    2004-01-01

    Full Text Available In this paper-work, by application of basic principles of general theory of system (systematic approach, we have formulated a model of marketing information system. Bases for research were basic characteristics of systematic approach and marketing system. Informational base for management of marketing system, i.e. marketing instruments was presented in a way that the most important information for decision making were listed per individual marketing mix instruments. In projected model of marketing information system, information listed in this way create a base for establishing of data bases, i.e. bases of information (data bases of: product, price, distribution, promotion. This paper-work gives basic preconditions for formulation and functioning of the model. Model was presented by explication of elements of its structure (environment, data bases operators, analysts of information system, decision makers - managers, i.e. input, process, output, feedback and relations between these elements which are necessary for its optimal functioning. Beside that, here are basic elements for implementation of the model into business system, as well as conditions for its efficient functioning and development.

  11. Community Involvement in Geoconservation: A Conceptual Approach Based on the Geoheritage of South Angola

    Directory of Open Access Journals (Sweden)

    Alexandre Oliveira Tavares

    2015-04-01

    Full Text Available In this work, it is argued that effective protection of geological objects displaying heritage value requires the local community’s involvement in all geoconservation actions, i.e., inventory, evaluation, conservation, valuation and monitoring procedures, and not only at the final part of the process, when it is expected from local communities that the physical integrity of such objects is guaranteed. Community involvement in geoheritage inventory and evaluation procedures can be appraised by using a classification system that integrates both the geoheritage properties displayed by the geological objects and usually recognized by geoscientists (i.e., relevance grade and the social role attributed to geological objects by communities outside Earth scientists that arise from the public perception of such objects (i.e., abstract perceptiveness. Using two case studies from southern Angola (Huíla Province where both social and scientific components were taken into account in geoheritage evaluation procedures (Tundavala and Leba geosites, we propose a conceptual community-based model, which can be applicable to geoconservation purposes and actions in other African regions and converging with the main goals of the “African Alive Corridors” initiative.

  12. Involving consumers in assessing service quality: benefits of using a qualitative approach.

    Science.gov (United States)

    Powell, J; Lovelock, R; Bray, J; Philp, I

    1994-01-01

    Although important to users, practice standards rarely incorporate users' views of care provided. These views are a valuable source of information, even though there are limits to their value. To improve the standards of care in a 20 bed hospital elderly care unit caring for acute medical conditions a qualitative approach was used. Patients' and carers' perceptions of care and problems with the process of care in the unit were elicited with a specially designed semistructured interview schedule in 83 separate tape recorded interviews with a research nurse in patients' homes. In all, 50 patients and 35 carers were interviewed between 6 June 1991 and 28 May 1992. Of the 50 patients, 33 were female; seven patients were aged less than 80 years, 16, 80-85; 21, 86-90; and six over 90. A total of 16 patients lived with spouses or other carers, two with non-carers, and 32 lived alone, 18 of whom received informal care. Content analysis of the interviews disclosed patients' and carers' general satisfaction with individualised professional care and planning of follow up services on discharge but dissatisfaction in the lack of information about and involvement in treatment and care and about specific staff notes. These findings have prompted remedial changes in clinical practice in the unit; they have also formed the structure of a criterion based survey of practice. The authors conclude that the qualitative approach suited elderly users and also provided the basis for the findings to be incorporated into a continuous audit cycle through a process of feedback and standard setting. PMID:10140234

  13. The Coriolis Effect: A Model for Student Involvement

    Science.gov (United States)

    Exline, Joseph D.

    1977-01-01

    Lists materials and procedures for constructing a model that demonstrates certain aspects of the Coriolis effect. Materials include an electric drill motor, voltage control, toy dart gun and darts, wood blocks of varying dimensions. Includes description of an experiment illustrating relationship between speed of rotation and amount of apparent…

  14. The Models and Approaches About The Parent Invıvement in Education Process

    Directory of Open Access Journals (Sweden)

    H.Ömer BEYDOĞAN

    2006-06-01

    Full Text Available School administrators need to work closely with parents (families in order to help their students catch achievement and deal with their problems in their life. In this resarch has provided some information about parent involvement models and approaches.In this study has been given range of same important issues:Using model and approach for guiding parental involvement, Improving communication and interaction with parents and Improving parental involvement explain the benefits of involving parents in their childrens education and how to overcome the barriers encountered.

  15. Mechanism involved in the UCB neurotoxicity on cellular models

    OpenAIRE

    Giraudi, Pablo Jose'

    2009-01-01

    Summary This doctoral thesis covers three years period (2006-2008) during which I have investigated the bilirubin neurotoxicity in the neuroblastoma SH-SY5Y cell line, a neuronal cell model widely used in the study of the pathogenesis and in the development of new therapeutic compounds for neurodegenerative diseases. In the first chapter is summarized the current knowledge about bilirubin chemistry and metabolism including disorders of bilirubin metabolism and the neuronal disturbanc...

  16. Regularization of turbulence - a comprehensive modeling approach

    Science.gov (United States)

    Geurts, B. J.

    2011-12-01

    Turbulence readily arises in numerous flows in nature and technology. The large number of degrees of freedom of turbulence poses serious challenges to numerical approaches aimed at simulating and controlling such flows. While the Navier-Stokes equations are commonly accepted to precisely describe fluid turbulence, alternative coarsened descriptions need to be developed to cope with the wide range of length and time scales. These coarsened descriptions are known as large-eddy simulations in which one aims to capture only the primary features of a flow, at considerably reduced computational effort. Such coarsening introduces a closure problem that requires additional phenomenological modeling. A systematic approach to the closure problem, know as regularization modeling, will be reviewed. Its application to multiphase turbulent will be illustrated in which a basic regularization principle is enforced to physically consistently approximate momentum and scalar transport. Examples of Leray and LANS-alpha regularization are discussed in some detail, as are compatible numerical strategies. We illustrate regularization modeling to turbulence under the influence of rotation and buoyancy and investigate the accuracy with which particle-laden flow can be represented. A discussion of the numerical and modeling errors incurred will be given on the basis of homogeneous isotropic turbulence.

  17. Merging Digital Surface Models Implementing Bayesian Approaches

    Science.gov (United States)

    Sadeq, H.; Drummond, J.; Li, Z.

    2016-06-01

    In this research different DSMs from different sources have been merged. The merging is based on a probabilistic model using a Bayesian Approach. The implemented data have been sourced from very high resolution satellite imagery sensors (e.g. WorldView-1 and Pleiades). It is deemed preferable to use a Bayesian Approach when the data obtained from the sensors are limited and it is difficult to obtain many measurements or it would be very costly, thus the problem of the lack of data can be solved by introducing a priori estimations of data. To infer the prior data, it is assumed that the roofs of the buildings are specified as smooth, and for that purpose local entropy has been implemented. In addition to the a priori estimations, GNSS RTK measurements have been collected in the field which are used as check points to assess the quality of the DSMs and to validate the merging result. The model has been applied in the West-End of Glasgow containing different kinds of buildings, such as flat roofed and hipped roofed buildings. Both quantitative and qualitative methods have been employed to validate the merged DSM. The validation results have shown that the model was successfully able to improve the quality of the DSMs and improving some characteristics such as the roof surfaces, which consequently led to better representations. In addition to that, the developed model has been compared with the well established Maximum Likelihood model and showed similar quantitative statistical results and better qualitative results. Although the proposed model has been applied on DSMs that were derived from satellite imagery, it can be applied to any other sourced DSMs.

  18. MERGING DIGITAL SURFACE MODELS IMPLEMENTING BAYESIAN APPROACHES

    Directory of Open Access Journals (Sweden)

    H. Sadeq

    2016-06-01

    Full Text Available In this research different DSMs from different sources have been merged. The merging is based on a probabilistic model using a Bayesian Approach. The implemented data have been sourced from very high resolution satellite imagery sensors (e.g. WorldView-1 and Pleiades. It is deemed preferable to use a Bayesian Approach when the data obtained from the sensors are limited and it is difficult to obtain many measurements or it would be very costly, thus the problem of the lack of data can be solved by introducing a priori estimations of data. To infer the prior data, it is assumed that the roofs of the buildings are specified as smooth, and for that purpose local entropy has been implemented. In addition to the a priori estimations, GNSS RTK measurements have been collected in the field which are used as check points to assess the quality of the DSMs and to validate the merging result. The model has been applied in the West-End of Glasgow containing different kinds of buildings, such as flat roofed and hipped roofed buildings. Both quantitative and qualitative methods have been employed to validate the merged DSM. The validation results have shown that the model was successfully able to improve the quality of the DSMs and improving some characteristics such as the roof surfaces, which consequently led to better representations. In addition to that, the developed model has been compared with the well established Maximum Likelihood model and showed similar quantitative statistical results and better qualitative results. Although the proposed model has been applied on DSMs that were derived from satellite imagery, it can be applied to any other sourced DSMs.

  19. Modelling and pathway identification involving the transport mechanism of a complex metabolic system in batch culture

    Science.gov (United States)

    Yuan, Jinlong; Zhang, Xu; Zhu, Xi; Feng, Enmin; Yin, Hongchao; Xiu, Zhilong

    2014-06-01

    The bio-dissimilation of glycerol to 1,3-propanediol (1,3-PD) by Klebsiella pneumoniae (K. pneumoniae) can be characterized by a complex metabolic system of interactions among biochemical fluxes, metabolic compounds, key enzymes and genetic regulation. In this paper, in consideration of the fact that the transport ways of 1,3-PD and glycerol with different weights across cell membrane are still unclear in batch culture, we consider 121 possible metabolic pathways and establish a novel mathematical model which is represented by a complex metabolic system. Taking into account the difficulty in accurately measuring the concentration of intracellular substances and the absence of equilibrium point for the metabolic system of batch culture, the novel approach used here is to define quantitatively biological robustness of the intracellular substance concentrations for the overall process of batch culture. To determine the most possible metabolic pathway, we take the defined biological robustness as cost function and establish an identification model, in which 1452 system parameters and 484 pathway parameters are involved. Simultaneously, the identification model is subject to the metabolic system, continuous state constraints and parameter constraints. As such, solving the identification model by a serial program is a very complicated task. We propose a parallel migration particle swarm optimization algorithm (MPSO) capable of solving the identification model in conjunction with the constraint transcription and smoothing approximation techniques. Numerical results show that the most possible metabolic pathway and the corresponding metabolic system can reasonably describe the process of batch culture.

  20. A new approach for Bayesian model averaging

    Institute of Scientific and Technical Information of China (English)

    TIAN XiangJun; XIE ZhengHui; WANG AiHui; YANG XiaoChun

    2012-01-01

    Bayesian model averaging (BMA) is a recently proposed statistical method for calibrating forecast ensembles from numerical weather models.However,successful implementation of BMA requires accurate estimates of the weights and variances of the individual competing models in the ensemble.Two methods,namely the Expectation-Maximization (EM) and the Markov Chain Monte Carlo (MCMC) algorithms,are widely used for BMA model training.Both methods have their own respective strengths and weaknesses.In this paper,we first modify the BMA log-likelihood function with the aim of removing the additional limitation that requires that the BMA weights add to one,and then use a limited memory quasi-Newtonian algorithm for solving the nonlinear optimization problem,thereby formulating a new approach for BMA (referred to as BMA-BFGS).Several groups of multi-model soil moisture simulation experiments from three land surface models show that the performance of BMA-BFGS is similar to the MCMC method in terms of simulation accuracy,and that both are superior to the EM algorithm.On the other hand,the computational cost of the BMA-BFGS algorithm is substantially less than for MCMC and is almost equivalent to that for EM.

  1. The challenges involved in elucidating the molecular basis of sperm-egg recognition in mammals and approaches to overcome them.

    Science.gov (United States)

    Wright, Gavin J; Bianchi, Enrica

    2016-01-01

    Sexual reproduction is used by many different organisms to create a new generation of genetically distinct progeny. Cells originating from separate sexes or mating types segregate their genetic material into haploid gametes which must then recognize and fuse with each other in a process known as fertilization to form a diploid zygote. Despite the central importance of fertilization, we know remarkably little about the molecular mechanisms that are involved in how gametes recognize each other, particularly in mammals, although the proteins that are displayed on their surfaces are almost certainly involved. This paucity of knowledge is largely due to both the unique biological properties of mammalian gametes (sperm and egg) which make them experimentally difficult to manipulate, and the technical challenges of identifying interactions between membrane-embedded cell surface receptor proteins. In this review, we will discuss our current knowledge of animal gamete recognition, highlighting where important contributions to our understanding were made, why particular model systems were helpful, and why progress in mammals has been particularly challenging. We discuss how the development of mammalian in vitro fertilization and targeted gene disruption in mice were important technological advances that triggered progress. We argue that approaches employed to discover novel interactions between cell surface gamete recognition proteins should account for the unusual biochemical properties of membrane proteins and the typically highly transient nature of their interactions. Finally, we describe how these principles were applied to identify Juno as the egg receptor for sperm Izumo1, an interaction that is essential for mammalian fertilization.

  2. An evolutionary genomic approach to identify genes involved in human birth timing.

    Directory of Open Access Journals (Sweden)

    Jevon Plunkett

    2011-04-01

    Full Text Available Coordination of fetal maturation with birth timing is essential for mammalian reproduction. In humans, preterm birth is a disorder of profound global health significance. The signals initiating parturition in humans have remained elusive, due to divergence in physiological mechanisms between humans and model organisms typically studied. Because of relatively large human head size and narrow birth canal cross-sectional area compared to other primates, we hypothesized that genes involved in parturition would display accelerated evolution along the human and/or higher primate phylogenetic lineages to decrease the length of gestation and promote delivery of a smaller fetus that transits the birth canal more readily. Further, we tested whether current variation in such accelerated genes contributes to preterm birth risk. Evidence from allometric scaling of gestational age suggests human gestation has been shortened relative to other primates. Consistent with our hypothesis, many genes involved in reproduction show human acceleration in their coding or adjacent noncoding regions. We screened >8,400 SNPs in 150 human accelerated genes in 165 Finnish preterm and 163 control mothers for association with preterm birth. In this cohort, the most significant association was in FSHR, and 8 of the 10 most significant SNPs were in this gene. Further evidence for association of a linkage disequilibrium block of SNPs in FSHR, rs11686474, rs11680730, rs12473870, and rs1247381 was found in African Americans. By considering human acceleration, we identified a novel gene that may be associated with preterm birth, FSHR. We anticipate other human accelerated genes will similarly be associated with preterm birth risk and elucidate essential pathways for human parturition.

  3. Promoting Latino Parent Involvement in K-8 Schools through a Communities of Practice Approach

    Science.gov (United States)

    Barrantes Santamaria, Alfredo G.

    2012-01-01

    Due to federal mandates, Title I schools now are being asked to implement parent involvement programs that meaningfully involve parents in the schools to increase academic gains. This action research study was based on three different concepts from the literature: a) critical pedagogy theory from Paulo Freire, b) parent involvement from diverse…

  4. Equilibrium models of coronal loops that involve curvature and buoyancy

    CERN Document Server

    Hindman, Bradley W

    2013-01-01

    We construct magnetostatic models of coronal loops in which the thermodynamics of the loop is fully consistent with the shape and geometry of the loop. This is achieved by treating the loop as a thin, compact, magnetic fibril that is a small departure from a force-free state. The density along the loop is related to the loop's curvature by requiring that the Lorentz force arising from this deviation is balanced by buoyancy. This equilibrium, coupled with hydrostatic balance and the ideal gas law, then connects the temperature of the loop with the curvature of the loop without resorting to a detailed treatment of heating and cooling. We present two example solutions: one with a spatially invariant magnetic Bond number (the dimensionless ratio of buoyancy to Lorentz forces) and the other with a constant radius of curvature of the loop's axis. We find that the density and temperature profiles are quite sensitive to curvature variations along the loop, even for loops with similar aspect ratios.

  5. Equilibrium Models of Coronal Loops That Involve Curvature and Buoyancy

    Science.gov (United States)

    Hindman, Bradley W.; Jain, Rekha

    2013-12-01

    We construct magnetostatic models of coronal loops in which the thermodynamics of the loop is fully consistent with the shape and geometry of the loop. This is achieved by treating the loop as a thin, compact, magnetic fibril that is a small departure from a force-free state. The density along the loop is related to the loop's curvature by requiring that the Lorentz force arising from this deviation is balanced by buoyancy. This equilibrium, coupled with hydrostatic balance and the ideal gas law, then connects the temperature of the loop with the curvature of the loop without resorting to a detailed treatment of heating and cooling. We present two example solutions: one with a spatially invariant magnetic Bond number (the dimensionless ratio of buoyancy to Lorentz forces) and the other with a constant radius of the curvature of the loop's axis. We find that the density and temperature profiles are quite sensitive to curvature variations along the loop, even for loops with similar aspect ratios.

  6. The independent spreaders involved SIR Rumor model in complex networks

    Science.gov (United States)

    Qian, Zhen; Tang, Shaoting; Zhang, Xiao; Zheng, Zhiming

    2015-07-01

    Recent studies of rumor or information diffusion process in complex networks show that in contrast to traditional comprehension, individuals who participate in rumor spreading within one network do not always get the rumor from their neighbors. They can obtain the rumor from different sources like online social networks and then publish it on their personal sites. In our paper, we discuss this phenomenon in complex networks by adopting the concept of independent spreaders. Rather than getting the rumor from neighbors, independent spreaders learn it from other channels. We further develop the classic "ignorant-spreaders-stiflers" or SIR model of rumor diffusion process in complex networks. A steady-state analysis is conducted to investigate the final spectrum of the rumor spreading under various spreading rate, stifling rate, density of independent spreaders and average degree of the network. Results show that independent spreaders effectively enhance the rumor diffusion process, by delivering the rumor to regions far away from the current rumor infected regions. And though the rumor spreading process in SF networks is faster than that in ER networks, the final size of rumor spreading in ER networks is larger than that in SF networks.

  7. A model of the supplier involvement in the product innovation

    Directory of Open Access Journals (Sweden)

    Kumar Manoj

    2017-01-01

    Full Text Available In this paper we examine the product innovation in a supply chain by a supplier and derive a model for a supplier’s product innovation policy. The product innovation of a supplier can contribute to the long-term competitiveness for the supply chain, and as it is for many supply chains a major factor, it should be considered in the development of strategies for a supplier. Here, we evaluate the effectiveness of supplier product innovation as a strategic tool to enhance the competitiveness and viability of supply chain. This paper explores the dynamic research performance of a supplier with endogenous time preference under a given arrangement of product innovation. We find that the optimal effort level and the achieved product innovation obey a saddle point path, or show tremendous fluctuations even without introducing the stochastic nature of product innovative activity. We also find that the fluctuation frequency is largely dependent both on the supplier’s characteristics such as supplier’s product innovative ability and on the nature of product innovation process per se. Short-run analyses are also made on the effect of supply chain cooperation in the product innovation process.

  8. AN AUTOMATIC APPROACH TO BOX & JENKINS MODELLING

    OpenAIRE

    MARCELO KRIEGER

    1983-01-01

    Apesar do reconhecimento amplo da qualidade das previsões obtidas na aplicação de um modelo ARIMA à previsão de séries temporais univariadas, seu uso tem permanecido restrito pela falta de procedimentos automáticos, computadorizados. Neste trabalho este problema é discutido e um algoritmo é proposto. Inspite of general recognition of the good forecasting ability of ARIMA models in predicting time series, this approach is not widely used because of the lack of ...

  9. Modeling in transport phenomena a conceptual approach

    CERN Document Server

    Tosun, Ismail

    2007-01-01

    Modeling in Transport Phenomena, Second Edition presents and clearly explains with example problems the basic concepts and their applications to fluid flow, heat transfer, mass transfer, chemical reaction engineering and thermodynamics. A balanced approach is presented between analysis and synthesis, students will understand how to use the solution in engineering analysis. Systematic derivations of the equations and the physical significance of each term are given in detail, for students to easily understand and follow up the material. There is a strong incentive in science and engineering to

  10. Modeling for fairness: A Rawlsian approach.

    Science.gov (United States)

    Diekmann, Sven; Zwart, Sjoerd D

    2014-06-01

    In this paper we introduce the overlapping design consensus for the construction of models in design and the related value judgments. The overlapping design consensus is inspired by Rawls' overlapping consensus. The overlapping design consensus is a well-informed, mutual agreement among all stakeholders based on fairness. Fairness is respected if all stakeholders' interests are given due and equal attention. For reaching such fair agreement, we apply Rawls' original position and reflective equilibrium to modeling. We argue that by striving for the original position, stakeholders expel invalid arguments, hierarchies, unwarranted beliefs, and bargaining effects from influencing the consensus. The reflective equilibrium requires that stakeholders' beliefs cohere with the final agreement and its justification. Therefore, the overlapping design consensus is not only an agreement to decisions, as most other stakeholder approaches, it is also an agreement to their justification and that this justification is consistent with each stakeholders' beliefs. For supporting fairness, we argue that fairness qualifies as a maxim in modeling. We furthermore distinguish values embedded in a model from values that are implied by its context of application. Finally, we conclude that for reaching an overlapping design consensus communication about properties of and values related to a model is required.

  11. Parents as Role Models: Parental Behavior Affects Adolescents' Plans for Work Involvement

    Science.gov (United States)

    Wiese, Bettina S.; Freund, Alexandra M.

    2011-01-01

    This study (N = 520 high-school students) investigates the influence of parental work involvement on adolescents' own plans regarding their future work involvement. As expected, adolescents' perceptions of parental work behavior affected their plans for own work involvement. Same-sex parents served as main role models for the adolescents' own…

  12. Pedagogic process modeling: Humanistic-integrative approach

    Directory of Open Access Journals (Sweden)

    Boritko Nikolaj M.

    2007-01-01

    Full Text Available The paper deals with some current problems of modeling the dynamics of the subject-features development of the individual. The term "process" is considered in the context of the humanistic-integrative approach, in which the principles of self education are regarded as criteria for efficient pedagogic activity. Four basic characteristics of the pedagogic process are pointed out: intentionality reflects logicality and regularity of the development of the process; discreteness (stageability in dicates qualitative stages through which the pedagogic phenomenon passes; nonlinearity explains the crisis character of pedagogic processes and reveals inner factors of self-development; situationality requires a selection of pedagogic conditions in accordance with the inner factors, which would enable steering the pedagogic process. Offered are two steps for singling out a particular stage and the algorithm for developing an integrative model for it. The suggested conclusions might be of use for further theoretic research, analyses of educational practices and for realistic predicting of pedagogical phenomena. .

  13. Nuclear level density: Shell-model approach

    Science.gov (United States)

    Sen'kov, Roman; Zelevinsky, Vladimir

    2016-06-01

    Knowledge of the nuclear level density is necessary for understanding various reactions, including those in the stellar environment. Usually the combinatorics of a Fermi gas plus pairing is used for finding the level density. Recently a practical algorithm avoiding diagonalization of huge matrices was developed for calculating the density of many-body nuclear energy levels with certain quantum numbers for a full shell-model Hamiltonian. The underlying physics is that of quantum chaos and intrinsic thermalization in a closed system of interacting particles. We briefly explain this algorithm and, when possible, demonstrate the agreement of the results with those derived from exact diagonalization. The resulting level density is much smoother than that coming from conventional mean-field combinatorics. We study the role of various components of residual interactions in the process of thermalization, stressing the influence of incoherent collision-like processes. The shell-model results for the traditionally used parameters are also compared with standard phenomenological approaches.

  14. Modeling Social Annotation: a Bayesian Approach

    CERN Document Server

    Plangprasopchok, Anon

    2008-01-01

    Collaborative tagging systems, such as del.icio.us, CiteULike, and others, allow users to annotate objects, e.g., Web pages or scientific papers, with descriptive labels called tags. The social annotations, contributed by thousands of users, can potentially be used to infer categorical knowledge, classify documents or recommend new relevant information. Traditional text inference methods do not make best use of socially-generated data, since they do not take into account variations in individual users' perspectives and vocabulary. In a previous work, we introduced a simple probabilistic model that takes interests of individual annotators into account in order to find hidden topics of annotated objects. Unfortunately, our proposed approach had a number of shortcomings, including overfitting, local maxima and the requirement to specify values for some parameters. In this paper we address these shortcomings in two ways. First, we extend the model to a fully Bayesian framework. Second, we describe an infinite ver...

  15. Introducing an Intervention Model for Fostering Affective Involvement with Persons Who Are Congenitally Deafblind

    Science.gov (United States)

    Martens, Marga A. W.; Janssen, Marleen J.; Ruijssenaars, Wied A. J. J. M.; Riksen-Walraven, J. Marianne

    2014-01-01

    The article presented here introduces the Intervention Model for Affective Involvement (IMAI), which was designed to train staff members (for example, teachers, caregivers, support workers) to foster affective involvement during interaction and communication with persons who have congenital deaf-blindness. The model is theoretically underpinned,…

  16. Multicomponent Equilibrium Models for Testing Geothermometry Approaches

    Energy Technology Data Exchange (ETDEWEB)

    Carl D. Palmer; Robert W. Smith; Travis L. McLing

    2013-02-01

    Geothermometry is an important tool for estimating deep reservoir temperature from the geochemical composition of shallower and cooler waters. The underlying assumption of geothermometry is that the waters collected from shallow wells and seeps maintain a chemical signature that reflects equilibrium in the deeper reservoir. Many of the geothermometers used in practice are based on correlation between water temperatures and composition or using thermodynamic calculations based a subset (typically silica, cations or cation ratios) of the dissolved constituents. An alternative approach is to use complete water compositions and equilibrium geochemical modeling to calculate the degree of disequilibrium (saturation index) for large number of potential reservoir minerals as a function of temperature. We have constructed several “forward” geochemical models using The Geochemist’s Workbench to simulate the change in chemical composition of reservoir fluids as they migrate toward the surface. These models explicitly account for the formation (mass and composition) of a steam phase and equilibrium partitioning of volatile components (e.g., CO2, H2S, and H2) into the steam as a result of pressure decreases associated with upward fluid migration from depth. We use the synthetic data generated from these simulations to determine the advantages and limitations of various geothermometry and optimization approaches for estimating the likely conditions (e.g., temperature, pCO2) to which the water was exposed in the deep subsurface. We demonstrate the magnitude of errors that can result from boiling, loss of volatiles, and analytical error from sampling and instrumental analysis. The estimated reservoir temperatures for these scenarios are also compared to conventional geothermometers. These results can help improve estimation of geothermal resource temperature during exploration and early development.

  17. A semiparametric approach to physiological flow models.

    Science.gov (United States)

    Verotta, D; Sheiner, L B; Ebling, W F; Stanski, D R

    1989-08-01

    By regarding sampled tissues in a physiological model as linear subsystems, the usual advantages of flow models are preserved while mitigating two of their disadvantages, (i) the need for assumptions regarding intratissue kinetics, and (ii) the need to simultaneously fit data from several tissues. To apply the linear systems approach, both arterial blood and (interesting) tissue drug concentrations must be measured. The body is modeled as having an arterial compartment (A) distributing drug to different linear subsystems (tissues), connected in a specific way by blood flow. The response (CA, with dimensions of concentration) of A is measured. Tissues receive input from A (and optionally from other tissues), and send output to the outside or to other parts of the body. The response (CT, total amount of drug in the tissue (T) divided by the volume of T) from the T-th one, for example, of such tissues is also observed. From linear systems theory, CT can be expressed as the convolution of CA with a disposition function, F(t) (with dimensions 1/time). The function F(t) depends on the (unknown) structure of T, but has certain other constant properties: The integral integral infinity0 F(t) dt is the steady state ratio of CT to CA, and the point F(0) is the clearance rate of drug from A to T divided by the volume of T. A formula for the clearance rate of drug from T to outside T can be derived. To estimate F(t) empirically, and thus mitigate disadvantage (i), we suggest that, first, a nonparametric (or parametric) function be fitted to CA data yielding predicted values, CA, and, second, the convolution integral of CA with F(t) be fitted to CT data using a deconvolution method. By so doing, each tissue's data are analyzed separately, thus mitigating disadvantage (ii). A method for system simulation is also proposed. The results of applying the approach to simulated data and to real thiopental data are reported.

  18. A Cognitive Therapy Approach to Increasing Father Involvement by Changing Restrictive Masculine Schemas

    Science.gov (United States)

    Mahalik, James R.; Morrison, Jay A.

    2006-01-01

    Cognitive therapists may be able to help fathers increase their involvement with their children by identifying and changing restrictive masculine schemas that interfere with men's parenting roles. In this paper, we (a) discuss the development of restrictive masculine schemas, (b) explain how these schemas may affect men's involvement in fathering…

  19. A Networks Approach to Modeling Enzymatic Reactions.

    Science.gov (United States)

    Imhof, P

    2016-01-01

    Modeling enzymatic reactions is a demanding task due to the complexity of the system, the many degrees of freedom involved and the complex, chemical, and conformational transitions associated with the reaction. Consequently, enzymatic reactions are not determined by precisely one reaction pathway. Hence, it is beneficial to obtain a comprehensive picture of possible reaction paths and competing mechanisms. By combining individually generated intermediate states and chemical transition steps a network of such pathways can be constructed. Transition networks are a discretized representation of a potential energy landscape consisting of a multitude of reaction pathways connecting the end states of the reaction. The graph structure of the network allows an easy identification of the energetically most favorable pathways as well as a number of alternative routes.

  20. Oxaliplatin neurotoxicity involves peroxisome alterations. PPARγ agonism as preventive pharmacological approach.

    Directory of Open Access Journals (Sweden)

    Matteo Zanardelli

    Full Text Available The development of neuropathic syndromes is an important, dose limiting side effect of anticancer agents like platinum derivates, taxanes and vinca alkaloids. The causes of neurotoxicity are still unclear but the impairment of the oxidative equilibrium is strictly related to pain. Two intracellular organelles, mitochondria and peroxisomes cooperate to the maintaining of the redox cellular state. Whereas a relationship between chemotherapy-dependent mitochondrial alteration and neuropathy has been established, the role of peroxisome is poor explored. In order to study the mechanisms of oxaliplatin-induced neurotoxicity, peroxisomal involvement was evaluated in vitro and in vivo. In primary rat astrocyte cell culture, oxaliplatin (10 µM for 48 h or 1 µM for 5 days increased the number of peroxisomes, nevertheless expression and functionality of catalase, the most important antioxidant defense enzyme in mammalian peroxisomes, were significantly reduced. Five day incubation with the selective Peroxisome Proliferator Activated Receptor-γ (PPAR-γ antagonist G3335 (30 µM induced a similar peroxisomal impairment suggesting a relationship between PPARγ signaling and oxaliplatin neurotoxicity. The PPARγ agonist rosiglitazone (10 µM reduced the harmful effects induced both by G3335 and oxaliplatin. In vivo, in a rat model of oxaliplatin induced neuropathy, a repeated treatment with rosiglitazone (3 and 10 mg kg(-1 per os significantly reduced neuropathic pain evoked by noxious (Paw pressure test and non-noxious (Cold plate test stimuli. The behavioral effect paralleled with the prevention of catalase impairment induced by oxaliplatin in dorsal root ganglia. In the spinal cord, catalase protection was showed by the lower rosiglitazone dosage without effect on the astrocyte density increase induced by oxaliplatin. Rosiglitazone did not alter the oxaliplatin-induced mortality of the human colon cancer cell line HT-29. These results highlight the role

  1. A systems toxicology approach to elucidate the mechanisms involved in RDX species-specific sensitivity.

    Science.gov (United States)

    Warner, Christopher M; Gust, Kurt A; Stanley, Jacob K; Habib, Tanwir; Wilbanks, Mitchell S; Garcia-Reyero, Natàlia; Perkins, Edward J

    2012-07-17

    Interspecies uncertainty factors in ecological risk assessment provide conservative estimates of risk where limited or no toxicity data is available. We quantitatively examined the validity of interspecies uncertainty factors by comparing the responses of zebrafish (Danio rerio) and fathead minnow (Pimephales promelas) to the energetic compound 1,3,5-trinitroperhydro-1,3,5-triazine (RDX), a known neurotoxicant. Relative toxicity was measured through transcriptional, morphological, and behavioral end points in zebrafish and fathead minnow fry exposed for 96 h to RDX concentrations ranging from 0.9 to 27.7 mg/L. Spinal deformities and lethality occurred at 1.8 and 3.5 mg/L RDX respectively for fathead minnow and at 13.8 and 27.7 mg/L for zebrafish, indicating that zebrafish have an 8-fold greater tolerance for RDX than fathead minnow fry. The number and magnitude of differentially expressed transcripts increased with increasing RDX concentration for both species. Differentially expressed genes were enriched in functions related to neurological disease, oxidative-stress, acute-phase response, vitamin/mineral metabolism and skeletal/muscular disorders. Decreased expression of collagen-coding transcripts were associated with spinal deformity and likely involved in sensitivity to RDX. Our work provides a mechanistic explanation for species-specific sensitivity to RDX where zebrafish responded at lower concentrations with greater numbers of functions related to RDX tolerance than fathead minnow. While the 10-fold interspecies uncertainty factor does provide a reasonable cross-species estimate of toxicity in the present study, the observation that the responses between ZF and FHM are markedly different does initiate a call for concern regarding establishment of broad ecotoxicological conclusions based on model species such as zebrafish.

  2. Evaluating face trustworthiness: a model based approach.

    Science.gov (United States)

    Todorov, Alexander; Baron, Sean G; Oosterhof, Nikolaas N

    2008-06-01

    Judgments of trustworthiness from faces determine basic approach/avoidance responses and approximate the valence evaluation of faces that runs across multiple person judgments. Here, based on trustworthiness judgments and using a computer model for face representation, we built a model for representing face trustworthiness (study 1). Using this model, we generated novel faces with an increased range of trustworthiness and used these faces as stimuli in a functional Magnetic Resonance Imaging study (study 2). Although participants did not engage in explicit evaluation of the faces, the amygdala response changed as a function of face trustworthiness. An area in the right amygdala showed a negative linear response-as the untrustworthiness of faces increased so did the amygdala response. Areas in the left and right putamen, the latter area extended into the anterior insula, showed a similar negative linear response. The response in the left amygdala was quadratic--strongest for faces on both extremes of the trustworthiness dimension. The medial prefrontal cortex and precuneus also showed a quadratic response, but their response was strongest to faces in the middle range of the trustworthiness dimension.

  3. Social Recovery Model: An 8-Year Investigation of Adolescent 12-step Group Involvement following Inpatient Treatment

    Science.gov (United States)

    Kelly, John F.; Brown, Sandra A.; Abrantes, Ana; Kahler, Christopher; Myers, Mark

    2013-01-01

    Background Despite widespread use of 12-step treatment approaches and referrals to Alcoholics Anonymous (AA) and Narcotics Anonymous (NA) by youth providers, little is known about the significance of these organizations in youth addiction recovery. Furthermore, existing evidence is based mostly on short-term follow-up and is limited methodologically. Methods Adolescent inpatients (N = 160; M age = 16, 40% female) were followed at 6-months, and at 1, 2, 4, 6, and 8 years post-treatment. Time-lagged, generalized estimating equations (GEE) modeled treatment outcome in relation to AA/NA attendance controlling for static and time-varying covariates. Robust regression (LOWESS) explored dose-response thresholds of AA/NA attendance on outcome. Results AA/NA attendance was common and intensive early post-treatment, but declined sharply and steadily over the 8-year period. Patients with greater addiction severity and those who believed they could not use substances in moderation were more likely to attend. Despite declining attendance, the effects related to AA/NA remained significant and consistent. Greater early participation was associated with better long-term outcomes. Conclusions Even though many youth discontinue AA/NA over time, attendees appear to benefit, and more severely substance-involved youth attend most. Successful early post-treatment engagement of youth in abstinence-supportive social contexts, such as AA/NA, may have long-term implications for alcohol and drug involvement into young adulthood. PMID:18557829

  4. A holistic approach to chronic pain management that involves all stakeholders: change is needed.

    Science.gov (United States)

    Kress, Hans-Georg; Aldington, Dominic; Alon, Eli; Coaccioli, Stefano; Collett, Beverly; Coluzzi, Flaminia; Huygen, Frank; Jaksch, Wolfgang; Kalso, Eija; Kocot-Kępska, Magdalena; Mangas, Ana Cristina; Ferri, Cesar Margarit; Mavrocordatos, Philippe; Morlion, Bart; Müller-Schwefe, Gerhard; Nicolaou, Andrew; Hernández, Concepción Pérez; Sichère, Patrick

    2015-01-01

    Chronic pain affects a large proportion of the population, imposing significant individual distress and a considerable burden on society, yet treatment is not always instituted and/or adequate. Comprehensive multidisciplinary management based on the biopsychosocial model of pain has been shown to be clinically effective and cost-efficient, but is not widely available. A literature review of stakeholder groups revealed many reasons for this, including: i) many patients believe healthcare professionals lack relevant knowledge, and consultations are rushed, ii) general practitioners consider that pain management has a low priority and is under-resourced, iii) pain specialists cite non-adherence to evidence-based treatment, sub-optimal prescribing, and chronic pain not being regarded as a disease in its own right, iv) nurses', pharmacists' and physiotherapists' skills are not fully utilized, and v) psychological therapy is employed infrequently and often too late. Many of the issues relating to physicians could be addressed by improving medical training, both at undergraduate and postgraduate levels - for example, by making pain medicine a compulsory core subject of the undergraduate medical curriculum. This would improve physician/patient communication, increase the use of standardized pain assessment tools, and allow more patients to participate in treatment decisions. Patient care would also benefit from improved training for other multidisciplinary team members; for example, nurses could provide counseling and follow-up support, psychologists offer coping skills training, and physiotherapists have a greater role in rehabilitation. Equally important measures include the widespread adoption of a patient-centered approach, chronic pain being recognized as a disease in its own right, and the development of universal guidelines for managing chronic non-cancer pain. Perhaps the greatest barrier to improvement is lack of political will at both national and international

  5. Approaches and models of intercultural education

    Directory of Open Access Journals (Sweden)

    Iván Manuel Sánchez Fontalvo

    2013-10-01

    Full Text Available Needed to be aware of the need to build an intercultural society, awareness must be assumed in all social spheres, where stands the role play education. A role of transcendental, since it must promote educational spaces to form people with virtues and powers that allow them to live together / as in multicultural contexts and social diversities (sometimes uneven in an increasingly globalized and interconnected world, and foster the development of feelings of civic belonging shared before the neighborhood, city, region and country, allowing them concern and critical judgement to marginalization, poverty, misery and inequitable distribution of wealth, causes of structural violence, but at the same time, wanting to work for the welfare and transformation of these scenarios. Since these budgets, it is important to know the approaches and models of intercultural education that have been developed so far, analysing their impact on the contexts educational where apply.   

  6. Cancer systems biology and modeling: microscopic scale and multiscale approaches.

    Science.gov (United States)

    Masoudi-Nejad, Ali; Bidkhori, Gholamreza; Hosseini Ashtiani, Saman; Najafi, Ali; Bozorgmehr, Joseph H; Wang, Edwin

    2015-02-01

    Cancer has become known as a complex and systematic disease on macroscopic, mesoscopic and microscopic scales. Systems biology employs state-of-the-art computational theories and high-throughput experimental data to model and simulate complex biological procedures such as cancer, which involves genetic and epigenetic, in addition to intracellular and extracellular complex interaction networks. In this paper, different systems biology modeling techniques such as systems of differential equations, stochastic methods, Boolean networks, Petri nets, cellular automata methods and agent-based systems are concisely discussed. We have compared the mentioned formalisms and tried to address the span of applicability they can bear on emerging cancer modeling and simulation approaches. Different scales of cancer modeling, namely, microscopic, mesoscopic and macroscopic scales are explained followed by an illustration of angiogenesis in microscopic scale of the cancer modeling. Then, the modeling of cancer cell proliferation and survival are examined on a microscopic scale and the modeling of multiscale tumor growth is explained along with its advantages.

  7. New modeling approach for bounding flight in birds.

    Science.gov (United States)

    Sachs, Gottfried; Lenz, Jakob

    2011-12-01

    A new modeling approach is presented which accounts for the unsteady motion features and dynamics characteristics of bounding flight. For this purpose, a realistic mathematical model is developed to describe the flight dynamics of a bird with regard to a motion which comprises flapping and bound phases involving acceleration and deceleration as well as, simultaneously, pull-up and push-down maneuvers. Furthermore, a mathematical optimization method is used for determining that bounding flight mode which yields the minimum energy expenditure per range. Thus, it can be shown to what extent bounding flight is aerodynamically superior to continuous flapping flight, yielding a reduction in the energy expenditure in the speed range practically above the maximum range speed. Moreover, the role of the body lift for the efficiency of bounding flight is identified and quantified. Introducing an appropriate non-dimensionalization of the relations describing the bird's flight dynamics, results of generally valid nature are derived for the addressed items.

  8. Practice-Informed Approaches to Addressing Substance Abuse and Trauma Exposure in Urban Native Families Involved with Child Welfare.

    Science.gov (United States)

    Lucero, Nancy M; Bussey, Marian

    2015-01-01

    Similar to families from other groups, urban-based American Indian and Alaska Native ("Native") family members involved with the child welfare system due to substance abuse issues are also often challenged by untreated trauma exposure. The link between these conditions and the history of genocidal policies aimed at destroying Native family ties, as well as experiences of ongoing discrimination, bring added dimensions for consideration when pro- viding services to these families. Practice-based evidence indicates that the trauma-informed and culturally responsive model developed by the Denver Indian Family Resource Center (DIFRC) shows promise in reducing out-of-home placements and re-referrals in urban Native families with substance abuse and child welfare concerns, while also increasing caregiver capabilities, family safety, and child well-being. This article provides strategies from the DIFRC approach that non-Native caseworkers and supervisors can utilize to create an environment in their own agencies that supports culturally based practice with Native families while incorporating a trauma-informed understanding of service needs of these families. Casework consistent with this approach demonstrates actions that meet the Active Efforts requirement of the Indian Child Welfare Act (ICWA) as well as sound clinical practice. Intensive and proactive case management designed specifically for families with high levels of service needs is a key strategy when combined with utilizing a caseworker brief screening tool for trauma exposure; training caseworkers to recognize trauma symptoms, making timely referrals to trauma treatment by behavioral health specialists experienced in working with Native clients, and providing a consistent service environment that focuses on client safety and worker trustworthiness. Finally, suggestions are put forth for agencies seeking to enhance their cultural responsiveness and include increasing workers' understanding of cultural values

  9. Modeling drug- and chemical- induced hepatotoxicity with systems biology approaches

    Directory of Open Access Journals (Sweden)

    Sudin eBhattacharya

    2012-12-01

    Full Text Available We provide an overview of computational systems biology approaches as applied to the study of chemical- and drug-induced toxicity. The concept of ‘toxicity pathways’ is described in the context of the 2007 US National Academies of Science report, Toxicity testing in the 21st Century: A Vision and A Strategy. Pathway mapping and modeling based on network biology concepts are a key component of the vision laid out in this report for a more biologically-based analysis of dose-response behavior and the safety of chemicals and drugs. We focus on toxicity of the liver (hepatotoxicity – a complex phenotypic response with contributions from a number of different cell types and biological processes. We describe three case studies of complementary multi-scale computational modeling approaches to understand perturbation of toxicity pathways in the human liver as a result of exposure to environmental contaminants and specific drugs. One approach involves development of a spatial, multicellular virtual tissue model of the liver lobule that combines molecular circuits in individual hepatocytes with cell-cell interactions and blood-mediated transport of toxicants through hepatic sinusoids, to enable quantitative, mechanistic prediction of hepatic dose-response for activation of the AhR toxicity pathway. Simultaneously, methods are being developing to extract quantitative maps of intracellular signaling and transcriptional regulatory networks perturbed by environmental contaminants, using a combination of gene expression and genome-wide protein-DNA interaction data. A predictive physiological model (DILIsymTM to understand drug-induced liver injury (DILI, the most common adverse event leading to termination of clinical development programs and regulatory actions on drugs, is also described. The model initially focuses on reactive metabolite-induced DILI in response to administration of acetaminophen, and spans multiple biological scales.

  10. Development and Validation of a Needs Assessment Model Using Stakeholders Involved in a University Program.

    Science.gov (United States)

    Labrecque, Monique

    1999-01-01

    Developed a needs-assessment model and validated the model with five groups of stakeholders connected with an undergraduate university nursing program in Canada. Used focus groups, questionnaires, a hermeneutic approach, and the magnitude-estimation scaling model to validate the model. Results show that respondents must define need to clarify the…

  11. A Bayesian modeling approach for generalized semiparametric structural equation models.

    Science.gov (United States)

    Song, Xin-Yuan; Lu, Zhao-Hua; Cai, Jing-Heng; Ip, Edward Hak-Sing

    2013-10-01

    In behavioral, biomedical, and psychological studies, structural equation models (SEMs) have been widely used for assessing relationships between latent variables. Regression-type structural models based on parametric functions are often used for such purposes. In many applications, however, parametric SEMs are not adequate to capture subtle patterns in the functions over the entire range of the predictor variable. A different but equally important limitation of traditional parametric SEMs is that they are not designed to handle mixed data types-continuous, count, ordered, and unordered categorical. This paper develops a generalized semiparametric SEM that is able to handle mixed data types and to simultaneously model different functional relationships among latent variables. A structural equation of the proposed SEM is formulated using a series of unspecified smooth functions. The Bayesian P-splines approach and Markov chain Monte Carlo methods are developed to estimate the smooth functions and the unknown parameters. Moreover, we examine the relative benefits of semiparametric modeling over parametric modeling using a Bayesian model-comparison statistic, called the complete deviance information criterion (DIC). The performance of the developed methodology is evaluated using a simulation study. To illustrate the method, we used a data set derived from the National Longitudinal Survey of Youth.

  12. Strategies to promote parental involvement in neuropediatric physiotherapy: an interdisciplinary approach

    Directory of Open Access Journals (Sweden)

    Lisandrea Rodrigues Menegasso Gennaro

    2014-04-01

    Full Text Available There is ample scientific evidence indicating that the participation of family members in interventions conducted with children is of critical importance. However, little information about the effectiveness of different strategies to increase parental involvement is available in the Brazilian research literature in Physiotherapy, even though family involvement is also of crucial importance in the treatment of children with neurological problems.  In this paper, we identify ways of involving parents that are reported in the areas of Early Childhood Education, Special Education, Music Education and Psychology (social skills training. Possibilities for adapting these strategies for use in Physiotherapy settings are discussed, so that professionals and managers of institutions that offer rehabilitation services could broaden their use of mechanisms to promote family participation, maximizing the results of rehabilitation treatment for children. In future studies, it will be important to evaluate the viability and effectiveness of adopting these strategies in Physiotherapy settings.

  13. Effects of deceptive packaging and product involvement on purchase intention: an elaboration likelihood model perspective.

    Science.gov (United States)

    Lammers, H B

    2000-04-01

    From an Elaboration Likelihood Model perspective, it was hypothesized that postexposure awareness of deceptive packaging claims would have a greater negative effect on scores for purchase intention by consumers lowly involved rather than highly involved with a product (n = 40). Undergraduates who were classified as either highly or lowly (ns = 20 and 20) involved with M&Ms examined either a deceptive or non-deceptive package design for M&Ms candy and were subsequently informed of the deception employed in the packaging before finally rating their intention to purchase. As anticipated, highly deceived subjects who were low in involvement rated intention to purchase lower than their highly involved peers. Overall, the results attest to the robustness of the model and suggest that the model has implications beyond advertising effects and into packaging effects.

  14. Dilemmas of involvement in land management – Comparing an active (Dutch) and a passive (German) approach

    NARCIS (Netherlands)

    Thomas, Hartmann; Spit, Tejo

    2015-01-01

    What is the role of spatial planners in urban development? Planners can be very involved in the realization of the land-use plans or they can take a more passive role in development processes. Which role they take depends on the particular institutional arrangements for land management in each count

  15. Modeling the Relations among Parental Involvement, School Engagement and Academic Performance of High School Students

    Science.gov (United States)

    Al-Alwan, Ahmed F.

    2014-01-01

    The author proposed a model to explain how parental involvement and school engagement related to academic performance. Participants were (671) 9th and 10th graders students who completed two scales of "parental involvement" and "school engagement" in their regular classrooms. Results of the path analysis suggested that the…

  16. An integrated approach to permeability modeling using micro-models

    Energy Technology Data Exchange (ETDEWEB)

    Hosseini, A.H.; Leuangthong, O.; Deutsch, C.V. [Society of Petroleum Engineers, Canadian Section, Calgary, AB (Canada)]|[Alberta Univ., Edmonton, AB (Canada)

    2008-10-15

    An important factor in predicting the performance of steam assisted gravity drainage (SAGD) well pairs is the spatial distribution of permeability. Complications that make the inference of a reliable porosity-permeability relationship impossible include the presence of short-scale variability in sand/shale sequences; preferential sampling of core data; and uncertainty in upscaling parameters. Micro-modelling is a simple and effective method for overcoming these complications. This paper proposed a micro-modeling approach to account for sampling bias, small laminated features with high permeability contrast, and uncertainty in upscaling parameters. The paper described the steps and challenges of micro-modeling and discussed the construction of binary mixture geo-blocks; flow simulation and upscaling; extended power law formalism (EPLF); and the application of micro-modeling and EPLF. An extended power-law formalism to account for changes in clean sand permeability as a function of macroscopic shale content was also proposed and tested against flow simulation results. There was close agreement between the model and simulation results. The proposed methodology was also applied to build the porosity-permeability relationship for laminated and brecciated facies of McMurray oil sands. Experimental data was in good agreement with the experimental data. 8 refs., 17 figs.

  17. Development of a computationally efficient urban modeling approach

    DEFF Research Database (Denmark)

    Wolfs, Vincent; Murla, Damian; Ntegeka, Victor

    2016-01-01

    This paper presents a parsimonious and data-driven modelling approach to simulate urban floods. Flood levels simulated by detailed 1D-2D hydrodynamic models can be emulated using the presented conceptual modelling approach with a very short calculation time. In addition, the model detail can be a...

  18. A Latent Cluster-Mean Approach to the Contextual Effects Model with Missing Data

    Science.gov (United States)

    Shin, Yongyun; Raudenbush, Stephen W.

    2010-01-01

    In organizational studies involving multiple levels, the association between a covariate and an outcome often differs at different levels of aggregation, giving rise to widespread interest in "contextual effects models." Such models partition the regression into within- and between-cluster components. The conventional approach uses each…

  19. User involvement in measuring service quality of local authority occupational therapy services: a new approach.

    NARCIS (Netherlands)

    Sixma, H.J.; Calnan, S.; Calnan, M.; Groenewegen, P.P.

    2001-01-01

    The aim of this paper is two-fold: (i) to describe the development of a new measuring instrument for quality of care from the perspective of the users of local authority Occupational Therapy (OT) services, and (ii) to evaluate the potential of the new instrument as a standardized approach for the

  20. Longitudinal Changes in Behavioral Approach System Sensitivity and Brain Structures Involved in Reward Processing during Adolescence

    Science.gov (United States)

    Urosevic, Snezana; Collins, Paul; Muetzel, Ryan; Lim, Kelvin; Luciana, Monica

    2012-01-01

    Adolescence is a period of radical normative changes and increased risk for substance use, mood disorders, and physical injury. Researchers have proposed that increases in reward sensitivity (i.e., sensitivity of the behavioral approach system [BAS]) and/or increases in reactivity to all emotional stimuli (i.e., reward and threat sensitivities)…

  1. An Ecological Approach to Prospective and Retrospective Timing of Long Durations: A Study Involving Gamers

    OpenAIRE

    Simon Tobin; Nicolas Bisson; Simon Grondin

    2010-01-01

    To date, most studies comparing prospective and retrospective timing have failed to use long durations and tasks with a certain degree of ecological validity. The present study assessed the effect of the timing paradigm on playing video games in a "naturalistic environment" (gaming centers). In addition, as it involved gamers, it provided an opportunity to examine the effect of gaming profile on time estimation. A total of 116 participants were asked to estimate prospectively or retrospective...

  2. Modeling economic costs of disasters and recovery involving positive effects of reconstruction: analysis using a dynamic CGE model

    Directory of Open Access Journals (Sweden)

    W. Xie

    2013-11-01

    Full Text Available Disaster damages have negative effects on economy, whereas reconstruction investments have positive effects. The aim of this study is to model economic causes of disasters and recovery involving positive effects of reconstruction activities. Computable general equilibrium (CGE model is a promising approach because it can incorporate these two kinds of shocks into a unified framework and further avoid double-counting problem. In order to factor both shocks in CGE model, direct loss is set as the amount of capital stock reduced on supply side of economy; A portion of investments restore the capital stock in existing period; An investment-driven dynamic model is formulated due to available reconstruction data, and the rest of a given country's saving is set as an endogenous variable. The 2008 Wenchuan Earthquake is selected as a case study to illustrate the model, and three scenarios are constructed: S0 (no disaster occurs, S1 (disaster occurs with reconstruction investment and S2 (disaster occurs without reconstruction investment. S0 is taken as business as usual, and the differences between S1 and S0 and that between S2 and S0 can be interpreted as economic losses including reconstruction and excluding reconstruction respectively. The study showed that output from S1 is found to be closer to real data than that from S2. S2 overestimates economic loss by roughly two times that under S1. The gap in economic aggregate between S1 and S0 is reduced to 3% in 2011, a level that should take another four years to achieve under S2.

  3. Connectivity of channelized reservoirs: a modelling approach

    Energy Technology Data Exchange (ETDEWEB)

    Larue, David K. [ChevronTexaco, Bakersfield, CA (United States); Hovadik, Joseph [ChevronTexaco, San Ramon, CA (United States)

    2006-07-01

    Connectivity represents one of the fundamental properties of a reservoir that directly affects recovery. If a portion of the reservoir is not connected to a well, it cannot be drained. Geobody or sandbody connectivity is defined as the percentage of the reservoir that is connected, and reservoir connectivity is defined as the percentage of the reservoir that is connected to wells. Previous studies have mostly considered mathematical, physical and engineering aspects of connectivity. In the current study, the stratigraphy of connectivity is characterized using simple, 3D geostatistical models. Based on these modelling studies, stratigraphic connectivity is good, usually greater than 90%, if the net: gross ratio, or sand fraction, is greater than about 30%. At net: gross values less than 30%, there is a rapid diminishment of connectivity as a function of net: gross. This behaviour between net: gross and connectivity defines a characteristic 'S-curve', in which the connectivity is high for net: gross values above 30%, then diminishes rapidly and approaches 0. Well configuration factors that can influence reservoir connectivity are well density, well orientation (vertical or horizontal; horizontal parallel to channels or perpendicular) and length of completion zones. Reservoir connectivity as a function of net: gross can be improved by several factors: presence of overbank sandy facies, deposition of channels in a channel belt, deposition of channels with high width/thickness ratios, and deposition of channels during variable floodplain aggradation rates. Connectivity can be reduced substantially in two-dimensional reservoirs, in map view or in cross-section, by volume support effects and by stratigraphic heterogeneities. It is well known that in two dimensions, the cascade zone for the 'S-curve' of net: gross plotted against connectivity occurs at about 60% net: gross. Generalizing this knowledge, any time that a reservoir can be regarded as &apos

  4. Public involvement in breast cancer research: an analysis and model for future research.

    Science.gov (United States)

    McCormick, Sabrina; Brody, Julia; Brown, Phil; Polk, Ruth

    2004-01-01

    Public involvement in health program planning has been taking place for many years, and has provided a precedent for the emergence of public involvement in research conducted since the early 1990s. Such involvement is now widely seen in breast cancer research, due to the large public concern and major social movement activity. This article reviews current practices and general models of public involvement in research and constructs a prototype. The authors interviewed researchers, program officers, and laypeople in order to understand the obstacles, processes, and benefits. They conclude that public involvement has major ramifications for the democratization of science and the construction of knowledge by teaching lay people about science and sensitizing researchers to concerns of the public. There is growing support on the part of scientists and government agents for public involvement.

  5. Autonomous motivation: involvement in physical activity, and perceived sport competence: structural and mediator models.

    Science.gov (United States)

    Bagøien, Tor Egil; Halvari, Hallgeir

    2005-02-01

    Students in upper secondary school (N = 231, M = 16.6 yr., SD = 1.6) were tested on involvement in physical activity, perceived sport competence, using the Perceived Competence Scale of Harter, and motivational regulation on the Self-regulation Questionnaire of Ryan and Connell. Correlations were positive among involvement in physical activity, autonomous motivation, and perceived sport competence. A hypothetical model indicated that autonomous motivation mediates the relation between perceived sport competence and involvement in physical activity. Although LISREL analysis supported this mediation, the best model fit of the data supported a structural model with involvement in physical activity (R2 = .63) to mediate between autonomous motivation and perceived competence (R2 = .47). Results are interpreted and discussed in terms of self-determination theory.

  6. A modelling approach for improved implementation of information technology in manufacturing systems

    DEFF Research Database (Denmark)

    Larsen, Michael Holm; Langer, Gilad; Kirkby, Lars Phillip

    2000-01-01

    concept into practice. The paper demonstrates the use of the approach in a practical case, which involves modelling of the shop floor activities and control system at the aluminium parts production at a Danish manufacturer of state-of-the-art audio-video equipment and telephones.......The paper presents a modelling approach, which is based on the multiple view perspective of Soft Systems Methodology and an encapsulation of these perspectives into an object orientated model. The approach provides a structured procedure for putting theoretical abstractions of a new production...

  7. A Modelling Approach for Improved Implementation of Information Technology in Manufacturing Systems

    DEFF Research Database (Denmark)

    Langer, Gilad; Larsen, Michael Holm; Kirkby, Lars Phillip

    1997-01-01

    concept into practice. The paper demonstrates the use of the approach in a practical case. The case involves modelling of the shop floor activities and control system at the aluminium parts production at a Danish manufacturer of state-of-the-art audio-video equipment and telephones.......The paper presents a modelling approach which is based on the multiple view perspective of Soft Systems Methodology and an encapsulation of these perspectives into an object orientated model. The approach provide a structured procedure for putting theoretical abstractions of a new production...

  8. Students' Involvement in Authentic Modelling Practices as Contexts in Chemistry Education

    Science.gov (United States)

    Prins, Gjalt T.; Bulte, Astrid M. W.; van Driel, Jan H.; Pilot, Albert

    2009-11-01

    In science education students should come to understand the nature and significance of models. A promising strategy to achieve this goal is using authentic modelling practices as contexts for meaningful learning of models and modelling. An authentic practice is defined as professionals working with common motives and purposes, pertaining to a similar type of procedure and applying relevant knowledge on the modelling issue they work on. In this study we evaluate whether the use of authentic practices initiates adequate students’ involvement. This was done by investigating students’ interests, ownership, familiarity and complexity. In addition, we evaluated students’ expressed modelling procedures in response to the modelling issues. We designed learning tasks which were enacted by a focus group of students. Three primary data sources were used to collect data. Firstly, a group discussion was organised in which students’ reflected on both authentic practices. Secondly, students filled in written questionnaires containing items on affective and cognitive aspects. Thirdly, the realised modelling procedures by students were analysed. The results show that students’ involvement was successfully initiated, evidenced by motivated students, willingness to continue and the completeness and quality of the realised modelling procedures. The design of the learning tasks proved to be successful in realising this involvement. The results obtained in this study support the strategy of using authentic modelling practices as contexts for meaningful learning of models and modelling.

  9. Modeling Educational Content: The Cognitive Approach of the PALO Language

    Directory of Open Access Journals (Sweden)

    M. Felisa Verdejo Maíllo

    2004-01-01

    Full Text Available This paper presents a reference framework to describe educational material. It introduces the PALO Language as a cognitive based approach to Educational Modeling Languages (EML. In accordance with recent trends for reusability and interoperability in Learning Technologies, EML constitutes an evolution of the current content-centered specifications of learning material, involving the description of learning processes and methods from a pedagogical and instructional perspective. The PALO Language, thus, provides a layer of abstraction for the description of learning material, including the description of learning activities, structure and scheduling. The framework makes use of domain and pedagogical ontologies as a reusable and maintainable way to represent and store instructional content, and to provide a pedagogical level of abstraction in the authoring process.

  10. A New Approach in Regression Analysis for Modeling Adsorption Isotherms

    Directory of Open Access Journals (Sweden)

    Dana D. Marković

    2014-01-01

    Full Text Available Numerous regression approaches to isotherm parameters estimation appear in the literature. The real insight into the proper modeling pattern can be achieved only by testing methods on a very big number of cases. Experimentally, it cannot be done in a reasonable time, so the Monte Carlo simulation method was applied. The objective of this paper is to introduce and compare numerical approaches that involve different levels of knowledge about the noise structure of the analytical method used for initial and equilibrium concentration determination. Six levels of homoscedastic noise and five types of heteroscedastic noise precision models were considered. Performance of the methods was statistically evaluated based on median percentage error and mean absolute relative error in parameter estimates. The present study showed a clear distinction between two cases. When equilibrium experiments are performed only once, for the homoscedastic case, the winning error function is ordinary least squares, while for the case of heteroscedastic noise the use of orthogonal distance regression or Margart’s percent standard deviation is suggested. It was found that in case when experiments are repeated three times the simple method of weighted least squares performed as well as more complicated orthogonal distance regression method.

  11. Modeling healthcare authorization and claim submissions using the openEHR dual-model approach

    Directory of Open Access Journals (Sweden)

    Freire Sergio M

    2011-10-01

    Full Text Available Abstract Background The TISS standard is a set of mandatory forms and electronic messages for healthcare authorization and claim submissions among healthcare plans and providers in Brazil. It is not based on formal models as the new generation of health informatics standards suggests. The objective of this paper is to model the TISS in terms of the openEHR archetype-based approach and integrate it into a patient-centered EHR architecture. Methods Three approaches were adopted to model TISS. In the first approach, a set of archetypes was designed using ENTRY subclasses. In the second one, a set of archetypes was designed using exclusively ADMIN_ENTRY and CLUSTERs as their root classes. In the third approach, the openEHR ADMIN_ENTRY is extended with classes designed for authorization and claim submissions, and an ISM_TRANSITION attribute is added to the COMPOSITION class. Another set of archetypes was designed based on this model. For all three approaches, templates were designed to represent the TISS forms. Results The archetypes based on the openEHR RM (Reference Model can represent all TISS data structures. The extended model adds subclasses and an attribute to the COMPOSITION class to represent information on authorization and claim submissions. The archetypes based on all three approaches have similar structures, although rooted in different classes. The extended openEHR RM model is more semantically aligned with the concepts involved in a claim submission, but may disrupt interoperability with other systems and the current tools must be adapted to deal with it. Conclusions Modeling the TISS standard by means of the openEHR approach makes it aligned with ISO recommendations and provides a solid foundation on which the TISS can evolve. Although there are few administrative archetypes available, the openEHR RM is expressive enough to represent the TISS standard. This paper focuses on the TISS but its results may be extended to other billing

  12. An optimized field coverage planning approach for navigation of agricultural robots in fields involving obstacle areas

    DEFF Research Database (Denmark)

    Hameed, Ibahim; Bochtis, D.; Sørensen, C.A.

    2013-01-01

    automation technologies. Since the primary goal of an agricultural vehicle is the complete coverage of the cropped area within the field, an essential prerequisite is the capability of the mobile unit to cover the whole field area autonomously. In this paper, the main objective is to develop an approach......-field obstacle areas, the headland paths generation for the field and each obstacle area, the implementation of a genetic algorithm to optimize the sequence that the field robot vehicle will follow to visit the blocks, and an algorithmically generation of the task sequences derived from the farmer practices...

  13. Adolescents and Music Media: Toward an Involvement-Mediational Model of Consumption and Self-Concept

    Science.gov (United States)

    Kistler, Michelle; Rodgers, Kathleen Boyce; Power, Thomas; Austin, Erica Weintraub; Hill, Laura Griner

    2010-01-01

    Using social cognitive theory and structural regression modeling, we examined pathways between early adolescents' music media consumption, involvement with music media, and 3 domains of self-concept (physical appearance, romantic appeal, and global self-worth; N=124). A mediational model was supported for 2 domains of self-concept. Music media…

  14. Genomic approaches towards identification of components involved in peptide based cell growth of Arabidopsis thailana

    DEFF Research Database (Denmark)

    Mahmood, Khalid

    Secreted peptides are considered now as important signaling molecules involved in plant growth and development. Plant peptide containing sulfated tyrosine 1 (PSY1) is a small peptide that promotes cell elongation and expansion at nanomolar concentration. This is achieved through binding...... elongation. FAB1C is highly down regulated in psy1r mutant plants and is assumed to play role in acidification and formation of vacuole that may contribute in cell elongation. In short, our work provides insights how growth coordinated through cellular communication using PSY1 as a signal molecule....... to extracellular domain of the leucine-rich repeat (LRR) receptor kinase called PSY1R. Upon binding of the peptide, PSY1R transduces the signal by phosphorylating the plasma membrane H+-ATPase (AHA2) leading to proton extrusion results in cell elongation. To understand the molecular basis of PSY1 response...

  15. Fatal and serious road crashes involving young New Zealand drivers: a latent class clustering approach

    DEFF Research Database (Denmark)

    Weiss, Harold B.; Kaplan, Sigal; Prato, Carlo Giacomo

    2016-01-01

    a holistic overview of crash patterns useful for designing youth-targeted road safety programmes. We compiled a database of 8644 New Zealand crashes from 2002 to 2011 involving at least one 15–24-year-old driver and a fatal or serious injury for at least one road user. We considered crash location......The over-representation of young drivers in road crashes remains an important concern worldwide. Cluster analysis has been applied to young driver sub-groups, but its application by analysing crash occurrence is just emerging. We present a classification analysis that advances the field through......, infrastructure characteristics, environmental conditions, demographic characteristics, driving behaviour, and pre-crash manoeuvres. The analysis yielded 15 and 8 latent classes of, respectively, single-vehicle and multi-vehicle crashes, and average posterior probabilities measured the odds of correct...

  16. Identification and analysis of genes involved in bone formation - a genetic approach in zebrafish -

    NARCIS (Netherlands)

    Spoorendonk, K.M.

    2009-01-01

    For many years bone research has been mainly performed in mice, chicken, cell culture systems, or human material from the clinic. In this thesis, we make use of the zebrafish (Danio rerio), a relatively new model system in this field. This small teleost offers possibilities which makes it a great co

  17. Identification and analysis of genes involved in bone formation – a genetic approach in zebrafish –

    NARCIS (Netherlands)

    Spoorendonk, K.M.

    2009-01-01

    For many years bone research has been mainly performed in mice, chicken, cell culture systems, or human material from the clinic. In this thesis, we make use of the zebrafish (Danio rerio), a relatively new model system in this field. This small teleost offers possibilities which makes it a great co

  18. A holistic approach to chronic pain management that involves all stakeholders: change is needed

    NARCIS (Netherlands)

    H.-G. Kress (Hans-Georg); D. Aldington (Dominic); E. Alon (Eli); S. Coaccioli (Stefano); B. Collett; F. Coluzzi (Flaminia); F.J.P.M. Huygen (Frank); W. Jaksch; E. Kalso (Eija); M. Kocot-Keopska (Magdalena); A.C. Mangas (Ana Cristina); C.M. Ferri (Cesar Margarit); P. Mavrocordatos (Philippe); B. Morlion (Bart); G. Müller-Schwefe (Gerhard); A. Nicolaou (Andrew); C.P. Hernández (Concepción Pérez); P. Sichère (Patrick)

    2015-01-01

    textabstractChronic pain affects a large proportion of the population, imposing significant individual distress and a considerable burden on society, yet treatment is not always instituted and/or adequate. Comprehensive multidisciplinary management based on the biopsychosocial model of pain has been

  19. A holistic approach to chronic pain management that involves all stakeholders: change is needed

    NARCIS (Netherlands)

    H.-G. Kress (Hans-Georg); D. Aldington (Dominic); E. Alon (Eli); S. Coaccioli (Stefano); B. Collett; F. Coluzzi (Flaminia); F.J.P.M. Huygen (Frank); W. Jaksch; E. Kalso (Eija); M. Kocot-Keopska (Magdalena); A.C. Mangas (Ana Cristina); C.M. Ferri (Cesar Margarit); P. Mavrocordatos (Philippe); B. Morlion (Bart); G. Müller-Schwefe (Gerhard); A. Nicolaou (Andrew); C.P. Hernández (Concepción Pérez); P. Sichère (Patrick)

    2015-01-01

    textabstractChronic pain affects a large proportion of the population, imposing significant individual distress and a considerable burden on society, yet treatment is not always instituted and/or adequate. Comprehensive multidisciplinary management based on the biopsychosocial model of pain has been

  20. Multiscale method for modeling binding phenomena involving large objects: application to kinesin motor domains motion along microtubules.

    Science.gov (United States)

    Li, Lin; Alper, Joshua; Alexov, Emil

    2016-03-18

    Many biological phenomena involve the binding of proteins to a large object. Because the electrostatic forces that guide binding act over large distances, truncating the size of the system to facilitate computational modeling frequently yields inaccurate results. Our multiscale approach implements a computational focusing method that permits computation of large systems without truncating the electrostatic potential and achieves the high resolution required for modeling macromolecular interactions, all while keeping the computational time reasonable. We tested our approach on the motility of various kinesin motor domains. We found that electrostatics help guide kinesins as they walk: N-kinesins towards the plus-end, and C-kinesins towards the minus-end of microtubules. Our methodology enables computation in similar, large systems including protein binding to DNA, viruses, and membranes.

  1. Does Business Model Affect CSR Involvement? A Survey of Polish Manufacturing and Service Companies

    Directory of Open Access Journals (Sweden)

    Marzanna Katarzyna Witek-Hajduk

    2016-02-01

    Full Text Available The study explores links between types of business models used by companies and their involvement in CSR. As the main part of our conceptual framework we used a business model taxonomy developed by Dudzik and Witek-Hajduk, which identifies five types of models: traditionalists, market players, contractors, distributors, and integrators. From shared characteristics of the business model profiles, we proposed that market players and integrators will show significantly higher levels of involvement in CSR than the three other classes of companies. Among other things, both market players and integrators relied strongly on building own brand value and fostering harmonious supply channel relations, which served as a rationale for our hypothesis. The data for the study were obtained through a combined CATI and CAWI survey on a group of 385 managers of medium and large enterprises. The sample was representative for the three Polish industries of chemical manufacturing, food production, and retailing. Statistical methods included confirmatory factor analysis and one-way ANOVA with contrasts and post hoc tests. The findings supported our hypothesis, showing that market players and integrators were indeed more engaged in CSR than other groups of firms. This may suggest that managers in control of these companies could bolster the integrity of their business models by increasing CSR involvement. Another important contribution of the study was to propose and validate a versatile scale for assessing CSR involvement, which showed measurement invariance for all involved industries.

  2. A model for the occurrence and analysis of ionic thermocurrent spectrum involving different orders of kinetics

    Indian Academy of Sciences (India)

    Jai Prakash

    2013-01-01

    Ionic thermocurrent (ITC) spectrum is much similar to a thermoluminescence (TL) glow curve involving monomolecular kinetics. It has already been reported that different orders of kinetics are involved in TL processes, which depend specifically on the extent of recombination and simultaneous retrapping. It is found that the involvement of different orders of kinetics in ITC spectrum depends on the experimental conditions of polarization and rate of rapid cooling. Consequently, order of kinetics involved in the ITC spectrum does not represent any specific feature of the system under investigation. An equation is developed which explains the occurrence of ITC spectrum involving any order of kinetics. Dielectric relaxation parameters, order of kinetics and approximate number of dipoles per unit volume are evaluated conveniently and easily following the proposed model.

  3. An ecological approach to prospective and retrospective timing of long durations: a study involving gamers.

    Directory of Open Access Journals (Sweden)

    Simon Tobin

    Full Text Available To date, most studies comparing prospective and retrospective timing have failed to use long durations and tasks with a certain degree of ecological validity. The present study assessed the effect of the timing paradigm on playing video games in a "naturalistic environment" (gaming centers. In addition, as it involved gamers, it provided an opportunity to examine the effect of gaming profile on time estimation. A total of 116 participants were asked to estimate prospectively or retrospectively a video game session lasting 12, 35 or 58 minutes. The results indicate that time is perceived as longer in the prospective paradigm than in the retrospective one, although the variability of estimates is the same. Moreover, the 12-minute session was perceived as longer, proportionally, than the 35- and 58-minute sessions. The study also revealed that the number of hours participants spent playing video games per week was a significant predictor of time estimates. To account for the main findings, the differences between prospective and retrospective timing are discussed in quantitative terms using a proposed theoretical framework, which states that both paradigms use the same cognitive processes, but in different proportions. Finally, the hypothesis that gamers play more because they underestimate time is also discussed.

  4. Physiopathological approach to infective endocarditis in chronic hemodialysis patients: left heart versus right heart involvement.

    Science.gov (United States)

    Bentata, Yassamine

    2017-11-01

    Infectious endocarditis (IE), a complication that is both cardiac and infectious, occurs frequently and is associated with a heavy burden of morbidity and mortality in chronic hemodialysis patients (CHD). About 2-6% of chronic hemodialysis patients develop IE and the incidence is 50-60 times higher among CHD patients than in the general population. The left heart is the most frequent location of IE in CHD and the different published series report a prevalence of left valve involvement varying from 80% to 100%. Valvular and perivalvular abnormalities, alteration of the immune system, and bacteremia associated with repeated manipulation of the vascular access, particularly central venous catheters, comprise the main factors explaining the left heart IE in CHD patients. While left-sided IE develops in altered valves in a high-pressure system, right-sided IE on the contrary, generally develops in healthy valves in a low-pressure system. Right-sided IE is rare, with its incidence varying from 0% to 26% depending on the study, and the tricuspid valve is the main location. Might the massive influx of pathogenic and virulent germs via the central venous catheter to the right heart, with the tricuspid being the first contact valve, have a role in the physiopathology of IE in CHD, thus facilitating bacterial adhesion? While the physiopathology of left-sided IE entails multiple and convincing mechanisms, it is not the case for right-sided IE, for which the physiopathological mechanism is only partially understood and remains shrouded in mystery.

  5. Neonatal neurological disorders involving the brainstem: neurosonographic approaches through the squamous suture and the foramen magnum

    Energy Technology Data Exchange (ETDEWEB)

    Tu, Yi-Fang [National Cheng Kung University Hospital, Department of Emergency Medicine, Tainan (Taiwan); Chen, Cheng-Yu [National Defense Medical Center, Department of Radiology, Taipei (Taiwan); Lin, Yuh-Jey [National Cheng Kung University Hospital, Department of Pediatrics, Tainan (Taiwan); Chang, Ying-Chao [Kaohsiung Chang Gung Children Hospital, Department of Pediatrics, Kaohsiung (Taiwan); Huang, Chao-Ching [National Cheng Kung University Hospital, Department of Pediatrics, Tainan (Taiwan); National Cheng Kung University Hospital, Department of Institute of Molecular Medicine, Tainan (Taiwan)

    2005-09-01

    Brainstem damage which often indicates a critical condition is usually underestimated by trans-anterior-fontanel neurosonography (NS) owing to the far-field limitations. Instead, NS alternately scanning through the squamous suture of the temporal bones and the foramen magnum could provide a better visualization of the brainstem structures. The NS characteristics of brainstem lesions caused by various neonatal neurological disorders, such as hypoxic-ischemic encephalopathy (HIE), metabolic encephalopathy, birth trauma and bacterial meningoencephalitis, can be depicted at the acute stage. An echogenic change in the midbrain was found in patients with HIE or metabolic encephalopathy. In addition to the echogenic change, bilateral transtentorial temporal lobe herniation distorting the contour of the midbrain was observed in a patient with group B streptococcus meningoencephalitis, whereas echogenic changes at the level of the pons and/or the medulla oblongata, mainly localized in the dorsal part, could be observed in newborns with severe HIE, maple syrup urine disease or birth trauma. In this pictorial assay, we demonstrate the feasibility of NS imaging in evaluating the entire brainstem structure of critically ill neonates in the near field and illustrate the characteristic features of brainstem involvement in various neonatal neurological disorders along with computed tomography or magnetic resonance imaging correlation. (orig.)

  6. Proteomic Approaches Identify Members of Cofilin Pathway Involved in Oral Tumorigenesis

    Science.gov (United States)

    Polachini, Giovana M.; Sobral, Lays M.; Mercante, Ana M. C.; Paes-Leme, Adriana F.; Xavier, Flávia C. A.; Henrique, Tiago; Guimarães, Douglas M.; Vidotto, Alessandra; Fukuyama, Erica E.; Góis-Filho, José F.; Cury, Patricia M.; Curioni, Otávio A.; Michaluart Jr, Pedro; Silva, Adriana M. A.; Wünsch-Filho, Victor; Nunes, Fabio D.; Leopoldino, Andréia M.; Tajara, Eloiza H.

    2012-01-01

    The prediction of tumor behavior for patients with oral carcinomas remains a challenge for clinicians. The presence of lymph node metastasis is the most important prognostic factor but it is limited in predicting local relapse or survival. This highlights the need for identifying biomarkers that may effectively contribute to prediction of recurrence and tumor spread. In this study, we used one- and two-dimensional gel electrophoresis, mass spectrometry and immunodetection methods to analyze protein expression in oral squamous cell carcinomas. Using a refinement for classifying oral carcinomas in regard to prognosis, we analyzed small but lymph node metastasis-positive versus large, lymph node metastasis-negative tumors in order to contribute to the molecular characterization of subgroups with risk of dissemination. Specific protein patterns favoring metastasis were observed in the “more-aggressive” group defined by the present study. This group displayed upregulation of proteins involved in migration, adhesion, angiogenesis, cell cycle regulation, anti-apoptosis and epithelial to mesenchymal transition, whereas the “less-aggressive” group was engaged in keratinocyte differentiation, epidermis development, inflammation and immune response. Besides the identification of several proteins not yet described as deregulated in oral carcinomas, the present study demonstrated for the first time the role of cofilin-1 in modulating cell invasion in oral carcinomas. PMID:23227181

  7. Expanding the Work Phases Model: User and Expert Involvement in the Construction of Online Specialised Dictionaries

    DEFF Research Database (Denmark)

    Leroyer, Patrick

    The purpose of this article is to establish new proposals for the lexicographic process and the involvement of experts and users in the construction of online specialised dictionaries. It is argued that the ENeL action should also have a view to the development of innovative theories...... and methodologies for the construction of online specialised dictionaries, and a new model for user and expert involvement is proposed....

  8. Uncertainty in biology a computational modeling approach

    CERN Document Server

    Gomez-Cabrero, David

    2016-01-01

    Computational modeling of biomedical processes is gaining more and more weight in the current research into the etiology of biomedical problems and potential treatment strategies.  Computational modeling allows to reduce, refine and replace animal experimentation as well as to translate findings obtained in these experiments to the human background. However these biomedical problems are inherently complex with a myriad of influencing factors, which strongly complicates the model building and validation process.  This book wants to address four main issues related to the building and validation of computational models of biomedical processes: Modeling establishment under uncertainty Model selection and parameter fitting Sensitivity analysis and model adaptation Model predictions under uncertainty In each of the abovementioned areas, the book discusses a number of key-techniques by means of a general theoretical description followed by one or more practical examples.  This book is intended for graduate stude...

  9. A minimally invasive approach to restore function and esthetics in periodontally involved teeth.

    Science.gov (United States)

    Ricci, Andrea; Ferraris, Federico

    2011-01-01

    The objective of dental treatment is the elimination of the etiologic factors, the rehabilitation of function and esthetics, and, when possible, the maintenance of vitality and structure of the natural dentition. After the loss of the periodontal support, as a consequence of periodontal disease, it may be necessary to splint the residual teeth in order to improve their stability, and sometimes it is also necessary to modify the morphology to optimize the final esthetic outcome. In many periodontally treated teeth, prosthodontic treatment on the residual dentition will be required with an important loss of tooth structure as an unavoidable consequence. This procedure frequently requires endodontic treatment of the residual abutments in order to obtain the necessary space for replacement materials. Similar objectives could however be achieved through an alternative therapy where the esthetic remodeling of the teeth and the closure of the interproximal spaces is obtained with composite resin materials. The objective of this article is to present an alternative protocol to optimize the functional and esthetic result of periodontally treated cases, where the most frequent complication is the increased length of the clinical crown. This is obtained by utilizing a different conservative approach, which has as its main objective the stabilization of the residual teeth, the maintenance of their vitality, and the achievement of the best esthetic result possible.

  10. Prototyping and Active User Involvement in System Development: Towards a Cooperative Prototyping Approach

    DEFF Research Database (Denmark)

    Grønbæk, Kaj

    which led to a paper (Bannon & Grønbæk, 1989) which was outside the goals of my thesis. During the first year of my study I also wrote Paper 1 which was a theoretical elaboration of the prototyping aspects of my master thesis work. Overcoming the frustrations of the failed engagement in the O4......-5. These papers introduce and describe a Cooperative Prototyping approach. In conjunction with the writing of the five papers, I co-authored a chapter (Bødker & Grønbæk, 1991c) for the book Design at Work: Cooperative Design of Computer Systems (Greenbaum & Kyng, 1991). In conjunction with my research I have...... taught courses in system development at the Computer Science Department. In these courses prototyping was among the topics, and I have used both my own papers and the literature that I have studied for this teaching. I have also presented some of the results from my studies to practitioners by giving...

  11. ALREST High Fidelity Modeling Program Approach

    Science.gov (United States)

    2011-05-18

    Gases and Mixtures of Redlich - Kwong and Peng- Robinson Fluids Assumed pdf Model based on k- ε-g Model in NASA/LaRc Vulcan code Level Set model...Potential Attractiveness Of Liquid Hydrocarbon Engines For Boost Applications • Propensity Of Hydrocarbon Engines For Combustion Instability • Air

  12. A Hybrid Artificial Reputation Model Involving Interaction Trust, Witness Information and the Trust Model to Calculate the Trust Value of Service Providers

    Directory of Open Access Journals (Sweden)

    Gurdeep Singh Ransi

    2014-02-01

    Full Text Available Agent interaction in a community, such as the online buyer-seller scenario, is often uncertain, as when an agent comes in contact with other agents they initially know nothing about each other. Currently, many reputation models are developed that help service consumers select better service providers. Reputation models also help agents to make a decision on who they should trust and transact with in the future. These reputation models are either built on interaction trust that involves direct experience as a source of information or they are built upon witness information also known as word-of-mouth that involves the reports provided by others. Neither the interaction trust nor the witness information models alone succeed in such uncertain interactions. In this paper we propose a hybrid reputation model involving both interaction trust and witness information to address the shortcomings of existing reputation models when taken separately. A sample simulation is built to setup buyer-seller services and uncertain interactions. Experiments reveal that the hybrid approach leads to better selection of trustworthy agents where consumers select more reputable service providers, eventually helping consumers obtain more gains. Furthermore, the trust model developed is used in calculating trust values of service providers.

  13. Involvement of HTLV-I Tax and CREB in aneuploidy: a bioinformatics approach

    Directory of Open Access Journals (Sweden)

    Pumfery Anne

    2006-07-01

    Full Text Available Abstract Background Adult T-cell leukemia (ATL is a complex and multifaceted disease associated with human T-cell leukemia virus type 1 (HTLV-I infection. Tax, the viral oncoprotein, is considered a major contributor to cell cycle deregulation in HTLV-I transformed cells by either directly disrupting cellular factors (protein-protein interactions or altering their transcription profile. Tax transactivates these cellular promoters by interacting with transcription factors such as CREB/ATF, NF-κB, and SRF. Therefore by examining which factors upregulate a particular set of promoters we may begin to understand how Tax orchestrates leukemia development. Results We observed that CTLL cells stably expressing wild-type Tax (CTLL/WT exhibited aneuploidy as compared to a Tax clone deficient for CREB transactivation (CTLL/703. To better understand the contribution of Tax transactivation through the CREB/ATF pathway to the aneuploid phenotype, we performed microarray analysis comparing CTLL/WT to CTLL/703 cells. Promoter analysis of altered genes revealed that a subset of these genes contain CREB/ATF consensus sequences. While these genes had diverse functions, smaller subsets of genes were found to be involved in G2/M phase regulation, in particular kinetochore assembly. Furthermore, we confirmed the presence of CREB, Tax and RNA Polymerase II at the p97Vcp and Sgt1 promoters in vivo through chromatin immunoprecipitation in CTLL/WT cells. Conclusion These results indicate that the development of aneuploidy in Tax-expressing cells may occur in response to an alteration in the transcription profile, in addition to direct protein interactions.

  14. Dynamic energy budget approaches for modelling organismal ageing.

    Science.gov (United States)

    van Leeuwen, Ingeborg M M; Vera, Julio; Wolkenhauer, Olaf

    2010-11-12

    Ageing is a complex multifactorial process involving a progressive physiological decline that, ultimately, leads to the death of an organism. It involves multiple changes in many components that play fundamental roles under healthy and pathological conditions. Simultaneously, every organism undergoes accumulative 'wear and tear' during its lifespan, which confounds the effects of the ageing process. The scenario is complicated even further by the presence of both age-dependent and age-independent competing causes of death. Various manipulations have been shown to interfere with the ageing process. Calorie restriction, for example, has been reported to increase the lifespan of a wide range of organisms, which suggests a strong relation between energy metabolism and ageing. Such a link is also supported within the main theories for ageing: the free radical hypothesis, for instance, links oxidative damage production directly to energy metabolism. The Dynamic Energy Budgets (DEB) theory, which characterizes the uptake and use of energy by living organisms, therefore constitutes a useful tool for gaining insight into the ageing process. Here we compare the existing DEB-based modelling approaches and, then, discuss how new biological evidence could be incorporated within a DEB framework.

  15. Increasing Parental Involvement in the Primary Grades: The Magowan School Model.

    Science.gov (United States)

    Galen, Harlene

    Each school's version of a partnership with parents is unique, and no generic model exists. Designated in 1988 as one of 14 model schools in the New Jersey State Department of Education "Parents as Partners in Learning" project, the Mildred Magowan school in Edgewater Park has followed a systematic approach that has consistently led to…

  16. Childhood craniopharyngioma: greater hypothalamic involvement before surgery is associated with higher homeostasis model insulin resistance index

    Directory of Open Access Journals (Sweden)

    Sainte-Rose Christian

    2009-04-01

    Full Text Available Abstract Background Obesity seems to be linked to the hypothalamic involvement in craniopharyngioma. We evaluated the pre-surgery relationship between the degree of this involvement on magnetic resonance imaging and insulin resistance, as evaluated by the homeostasis model insulin resistance index (HOMA. As insulin-like growth factor 1, leptin, soluble leptin receptor (sOB-R and ghrelin may also be involved, we compared their plasma concentrations and their link to weight change. Methods 27 children with craniopharyngioma were classified as either grade 0 (n = 7, no hypothalamic involvement, grade 1 (n = 8, compression without involvement, or grade 2 (n = 12, severe involvement. Results Despite having similar body mass indexes (BMI, the grade 2 patients had higher glucose, insulin and HOMA before surgery than the grade 0 (P = 0.02, The data for the whole population before and 6–18 months after surgery showed increases in BMI (P Conclusion The hypothalamic involvement by the craniopharyngioma before surgery seems to determine the degree of insulin resistance, regardless of the BMI. The pre-surgery HOMA values were correlated with the post-surgery weight gain. This suggests that obesity should be prevented by reducing inn secretion in those cases with hypothalamic involvement.

  17. LEXICAL APPROACH IN TEACHING TURKISH: A COLLOCATIONAL STUDY MODEL

    National Research Council Canada - National Science Library

    Eser ÖRDEM

    2013-01-01

    Abstract This study intends to propose Lexical Approach (Lewis, 1998, 2002; Harwood, 2002) and a model for teaching Turkish as a foreign language so that this model can be used in classroom settings...

  18. A model-based multisensor data fusion knowledge management approach

    Science.gov (United States)

    Straub, Jeremy

    2014-06-01

    A variety of approaches exist for combining data from multiple sensors. The model-based approach combines data based on its support for or refutation of elements of the model which in turn can be used to evaluate an experimental thesis. This paper presents a collection of algorithms for mapping various types of sensor data onto a thesis-based model and evaluating the truth or falsity of the thesis, based on the model. The use of this approach for autonomously arriving at findings and for prioritizing data are considered. Techniques for updating the model (instead of arriving at a true/false assertion) are also discussed.

  19. Reducing uncertainty in flood frequency analyses: A comparison of local and regional approaches involving information on extreme historical floods

    Science.gov (United States)

    Halbert, K.; Nguyen, C. C.; Payrastre, O.; Gaume, E.

    2016-10-01

    This paper proposes a detailed comparison of local and regional approaches for flood frequency analyses, with a special emphasis on the effects of (a) the information on extreme floods used in the analysis (historical data or recent extreme floods observed at ungauged sites), and (b) the assumptions associated with regional approaches (statistical homogeneity of considered series, independence of observations). The results presented are based on two case studies: the Ard e ̀ che and Argens rivers regions in south-east of France. Four approaches are compared: 1 - local analysis based on continuous measured series, 2 - local analysis with historical information, 3 - regional index-flood analysis based on continuous series, 4 - regional analysis involving information on extremes (including both historical floods and recent floods observed at ungauged sites). The inference approach used is based on a GEV distribution and a Bayesian Monte Carlo Markov Chain approach for parameters estimation. The comparison relies both on (1) available observed datasets and (2) Monte Carlo simulations in order to evaluate the effects of sampling variability and to analyze the possible influence of regional heterogeneities. The results indicate that a relatively limited level of regional heterogeneity, which may not be detected through homogeneity tests, may significantly affect the performances of regional approaches. These results also illustrate the added value of information on extreme floods, historical floods or recent floods observed at ungauged sites, in both local and regional approaches. As far as possible, gathering such information and incorporating it into flood frequency studies should be promoted. Finally, the presented Monte Carlo simulations appear as an interesting analysis tool for adapting the estimation strategy to the available data for each specific case study.

  20. Comparison of two novel approaches to model fibre reinforced concrete

    NARCIS (Netherlands)

    Radtke, F.K.F.; Simone, A.; Sluys, L.J.

    2009-01-01

    We present two approaches to model fibre reinforced concrete. In both approaches, discrete fibre distributions and the behaviour of the fibre-matrix interface are explicitly considered. One approach employs the reaction forces from fibre to matrix while the other is based on the partition of unity f

  1. Modelling the World Wool Market: A Hybrid Approach

    OpenAIRE

    2007-01-01

    We present a model of the world wool market that merges two modelling traditions: the partialequilibrium commodity-specific approach and the computable general-equilibrium approach. The model captures the multistage nature of the wool production system, and the heterogeneous nature of raw wool, processed wool and wool garments. It also captures the important wool producing and consuming regions of the world. We illustrate the utility of the model by estimating the effects of tariff barriers o...

  2. An algebraic approach to the Hubbard model

    CERN Document Server

    de Leeuw, Marius

    2015-01-01

    We study the algebraic structure of an integrable Hubbard-Shastry type lattice model associated with the centrally extended su(2|2) superalgebra. This superalgebra underlies Beisert's AdS/CFT worldsheet R-matrix and Shastry's R-matrix. The considered model specializes to the one-dimensional Hubbard model in a certain limit. We demonstrate that Yangian symmetries of the R-matrix specialize to the Yangian symmetry of the Hubbard model found by Korepin and Uglov. Moreover, we show that the Hubbard model Hamiltonian has an algebraic interpretation as the so-called secret symmetry. We also discuss Yangian symmetries of the A and B models introduced by Frolov and Quinn.

  3. Numerical modelling approach for mine backfill

    Indian Academy of Sciences (India)

    MUHAMMAD ZAKA EMAD

    2017-09-01

    Numerical modelling is broadly used for assessing complex scenarios in underground mines, including mining sequence and blast-induced vibrations from production blasting. Sublevel stoping mining methods with delayed backfill are extensively used to exploit steeply dipping ore bodies by Canadian hard-rockmetal mines. Mine backfill is an important constituent of mining process. Numerical modelling of mine backfill material needs special attention as the numerical model must behave realistically and in accordance with the site conditions. This paper discusses a numerical modelling strategy for modelling mine backfill material. Themodelling strategy is studied using a case study mine from Canadian mining industry. In the end, results of numerical model parametric study are shown and discussed.

  4. Regularization of turbulence - a comprehensive modeling approach

    NARCIS (Netherlands)

    Geurts, Bernard J.

    2011-01-01

    Turbulence readily arises in numerous flows in nature and technology. The large number of degrees of freedom of turbulence poses serious challenges to numerical approaches aimed at simulating and controlling such flows. While the Navier-Stokes equations are commonly accepted to precisely describe fl

  5. Measuring equilibrium models: a multivariate approach

    Directory of Open Access Journals (Sweden)

    Nadji RAHMANIA

    2011-04-01

    Full Text Available This paper presents a multivariate methodology for obtaining measures of unobserved macroeconomic variables. The used procedure is the multivariate Hodrick-Prescot which depends on smoothing param eters. The choice of these parameters is crucial. Our approach is based on consistent estimators of these parameters, depending only on the observed data.

  6. A graphical approach to analogue behavioural modelling

    OpenAIRE

    Moser, Vincent; Nussbaum, Pascal; Amann, Hans-Peter; Astier, Luc; Pellandini, Fausto

    2007-01-01

    In order to master the growing complexity of analogue electronic systems, modelling and simulation of analogue hardware at various levels is absolutely necessary. This paper presents an original modelling method based on the graphical description of analogue electronic functional blocks. This method is intended to be automated and integrated into a design framework: specialists create behavioural models of existing functional blocks, that can then be used through high-level selection and spec...

  7. A geometrical approach to structural change modeling

    OpenAIRE

    Stijepic, Denis

    2013-01-01

    We propose a model for studying the dynamics of economic structures. The model is based on qualitative information regarding structural dynamics, in particular, (a) the information on the geometrical properties of trajectories (and their domains) which are studied in structural change theory and (b) the empirical information from stylized facts of structural change. We show that structural change is path-dependent in this model and use this fact to restrict the number of future structural cha...

  8. Consumer preference models: fuzzy theory approach

    Science.gov (United States)

    Turksen, I. B.; Wilson, I. A.

    1993-12-01

    Consumer preference models are widely used in new product design, marketing management, pricing and market segmentation. The purpose of this article is to develop and test a fuzzy set preference model which can represent linguistic variables in individual-level models implemented in parallel with existing conjoint models. The potential improvements in market share prediction and predictive validity can substantially improve management decisions about what to make (product design), for whom to make it (market segmentation) and how much to make (market share prediction).

  9. Multirule Based Diagnostic Approach for the Fog Predictions Using WRF Modelling Tool

    Directory of Open Access Journals (Sweden)

    Swagata Payra

    2014-01-01

    Full Text Available The prediction of fog onset remains difficult despite the progress in numerical weather prediction. It is a complex process and requires adequate representation of the local perturbations in weather prediction models. It mainly depends upon microphysical and mesoscale processes that act within the boundary layer. This study utilizes a multirule based diagnostic (MRD approach using postprocessing of the model simulations for fog predictions. The empiricism involved in this approach is mainly to bridge the gap between mesoscale and microscale variables, which are related to mechanism of the fog formation. Fog occurrence is a common phenomenon during winter season over Delhi, India, with the passage of the western disturbances across northwestern part of the country accompanied with significant amount of moisture. This study implements the above cited approach for the prediction of occurrences of fog and its onset time over Delhi. For this purpose, a high resolution weather research and forecasting (WRF model is used for fog simulations. The study involves depiction of model validation and postprocessing of the model simulations for MRD approach and its subsequent application to fog predictions. Through this approach model identified foggy and nonfoggy days successfully 94% of the time. Further, the onset of fog events is well captured within an accuracy of 30–90 minutes. This study demonstrates that the multirule based postprocessing approach is a useful and highly promising tool in improving the fog predictions.

  10. Expanding the Spectrum of Genes Involved in Huntington Disease Using a Combined Clinical and Genetic Approach.

    Science.gov (United States)

    Mariani, Louise-Laure; Tesson, Christelle; Charles, Perrine; Cazeneuve, Cécile; Hahn, Valérie; Youssov, Katia; Freeman, Leorah; Grabli, David; Roze, Emmanuel; Noël, Sandrine; Peuvion, Jean-Noel; Bachoud-Levi, Anne-Catherine; Brice, Alexis; Stevanin, Giovanni; Durr, Alexandra

    2016-09-01

    iron accumulation. We identified mutations in genes associated with neurodegeneration, including CACNA1A (n = 2), VPS13A (n = 1), UBQLN2 (n = 1), and VCP (n = 1). Huntington disease phenocopies without CAG repeat expansions in HTT are not rare, occurring in 12.4% (28 of 226) herein, and should be considered in genetic counseling. We used next-generation sequencing combined with clinical data and disease evolution to explore multiple etiologies simultaneously. Our combined clinical and genetic exploration of 28 HD phenocopies identified the underlying cause in 35.7% (10 of 28). In conclusion, the etiologies of HD phenocopies are heterogeneous, and clinical evolution should be taken into account when searching for a genetic cause. The panel of candidate genes to be examined is larger than expected but can be guided by specific imaging and clinical features. Other neurodegenerative diseases with late onset in which variant segregation cannot be verified could be productively explored with the combined approach illustrated herein.

  11. A New Approach for Magneto-Static Hysteresis Behavioral Modeling

    DEFF Research Database (Denmark)

    Astorino, Antonio; Swaminathan, Madhavan; Antonini, Giulio

    2016-01-01

    In this paper, a new behavioral modeling approach for magneto-static hysteresis is presented. Many accurate models are currently available, but none of them seems to be able to correctly reproduce all the possible B-H paths with low computational cost. By contrast, the approach proposed...... achieved when comparing the measured and simulated results....

  12. Nucleon Spin Content in a Relativistic Quark Potential Model Approach

    Institute of Scientific and Technical Information of China (English)

    DONG YuBing; FENG QingGuo

    2002-01-01

    Based on a relativistic quark model approach with an effective potential U(r) = (ac/2)(1 + γ0)r2, the spin content of the nucleon is investigated. Pseudo-scalar interaction between quarks and Goldstone bosons is employed to calculate the couplings between the Goldstone bosons and the nucleon. Different approaches to deal with the center of mass correction in the relativistic quark potential model approach are discussed.

  13. A simple approach to modeling ductile failure.

    Energy Technology Data Exchange (ETDEWEB)

    Wellman, Gerald William

    2012-06-01

    Sandia National Laboratories has the need to predict the behavior of structures after the occurrence of an initial failure. In some cases determining the extent of failure, beyond initiation, is required, while in a few cases the initial failure is a design feature used to tailor the subsequent load paths. In either case, the ability to numerically simulate the initiation and propagation of failures is a highly desired capability. This document describes one approach to the simulation of failure initiation and propagation.

  14. Beyond the detection of students´ mental models. An integrative representational approach

    Directory of Open Access Journals (Sweden)

    Ileana Maria Greca

    2002-01-01

    Full Text Available In this paper we initially discuss some limitations of the mental model theoretical framework for research in science education. Then, after an analysis of Vergnaud´s conceptual fields theory we propose an approach that integrating elements of both theoretical frameworks could provide a better understanding of some cognitive processes involved in the learning of scientific concepts. Finally, we suggest possible implications of this approach for science teaching as well as for research in this area.

  15. An approach for activity-based DEVS model specification

    DEFF Research Database (Denmark)

    Alshareef, Abdurrahman; Sarjoughian, Hessam S.; Zarrin, Bahram

    2016-01-01

    activity-based behavior modeling of parallel DEVS atomic models. We consider UML activities and actions as fundamental units of behavior modeling, especially in the presence of recent advances in the UML 2.5 specifications. We describe in detail how to approach activity modeling with a set of elemental...

  16. Advanced language modeling approaches, case study: Expert search

    NARCIS (Netherlands)

    Hiemstra, Djoerd

    2008-01-01

    This tutorial gives a clear and detailed overview of advanced language modeling approaches and tools, including the use of document priors, translation models, relevance models, parsimonious models and expectation maximization training. Expert search will be used as a case study to explain the

  17. Applying the Plan-Do-Study-Act (PDSA) approach to a large pragmatic study involving safety net clinics.

    Science.gov (United States)

    Coury, Jennifer; Schneider, Jennifer L; Rivelli, Jennifer S; Petrik, Amanda F; Seibel, Evelyn; D'Agostini, Brieshon; Taplin, Stephen H; Green, Beverly B; Coronado, Gloria D

    2017-06-19

    The Plan-Do-Study-Act (PDSA) cycle is a commonly used improvement process in health care settings, although its documented use in pragmatic clinical research is rare. A recent pragmatic clinical research study, called the Strategies and Opportunities to STOP Colon Cancer in Priority Populations (STOP CRC), used this process to optimize the research implementation of an automated colon cancer screening outreach program in intervention clinics. We describe the process of using this PDSA approach, the selection of PDSA topics by clinic leaders, and project leaders' reactions to using PDSA in pragmatic research. STOP CRC is a cluster-randomized pragmatic study that aims to test the effectiveness of a direct-mail fecal immunochemical testing (FIT) program involving eight Federally Qualified Health Centers in Oregon and California. We and a practice improvement specialist trained in the PDSA process delivered structured presentations to leaders of these centers; the presentations addressed how to apply the PDSA process to improve implementation of a mailed outreach program offering colorectal cancer screening through FIT tests. Center leaders submitted PDSA plans and delivered reports via webinar at quarterly meetings of the project's advisory board. Project staff conducted one-on-one, 45-min interviews with project leads from each health center to assess the reaction to and value of the PDSA process in supporting the implementation of STOP CRC. Clinic-selected PDSA activities included refining the intervention staffing model, improving outreach materials, and changing workflow steps. Common benefits of using PDSA cycles in pragmatic research were that it provided a structure for staff to focus on improving the program and it allowed staff to test the change they wanted to see. A commonly reported challenge was measuring the success of the PDSA process with the available electronic medical record tools. Understanding how the PDSA process can be applied to pragmatic

  18. Challenges and opportunities for integrating lake ecosystem modelling approaches

    Science.gov (United States)

    Mooij, Wolf M.; Trolle, Dennis; Jeppesen, Erik; Arhonditsis, George; Belolipetsky, Pavel V.; Chitamwebwa, Deonatus B.R.; Degermendzhy, Andrey G.; DeAngelis, Donald L.; Domis, Lisette N. De Senerpont; Downing, Andrea S.; Elliott, J. Alex; Ruberto, Carlos Ruberto; Gaedke, Ursula; Genova, Svetlana N.; Gulati, Ramesh D.; Hakanson, Lars; Hamilton, David P.; Hipsey, Matthew R.; Hoen, Jochem 't; Hulsmann, Stephan; Los, F. Hans; Makler-Pick, Vardit; Petzoldt, Thomas; Prokopkin, Igor G.; Rinke, Karsten; Schep, Sebastiaan A.; Tominaga, Koji; Van Dam, Anne A.; Van Nes, Egbert H.; Wells, Scott A.; Janse, Jan H.

    2010-01-01

    A large number and wide variety of lake ecosystem models have been developed and published during the past four decades. We identify two challenges for making further progress in this field. One such challenge is to avoid developing more models largely following the concept of others ('reinventing the wheel'). The other challenge is to avoid focusing on only one type of model, while ignoring new and diverse approaches that have become available ('having tunnel vision'). In this paper, we aim at improving the awareness of existing models and knowledge of concurrent approaches in lake ecosystem modelling, without covering all possible model tools and avenues. First, we present a broad variety of modelling approaches. To illustrate these approaches, we give brief descriptions of rather arbitrarily selected sets of specific models. We deal with static models (steady state and regression models), complex dynamic models (CAEDYM, CE-QUAL-W2, Delft 3D-ECO, LakeMab, LakeWeb, MyLake, PCLake, PROTECH, SALMO), structurally dynamic models and minimal dynamic models. We also discuss a group of approaches that could all be classified as individual based: super-individual models (Piscator, Charisma), physiologically structured models, stage-structured models and trait-based models. We briefly mention genetic algorithms, neural networks, Kalman filters and fuzzy logic. Thereafter, we zoom in, as an in-depth example, on the multi-decadal development and application of the lake ecosystem model PCLake and related models (PCLake Metamodel, Lake Shira Model, IPH-TRIM3D-PCLake). In the discussion, we argue that while the historical development of each approach and model is understandable given its 'leading principle', there are many opportunities for combining approaches. We take the point of view that a single 'right' approach does not exist and should not be strived for. Instead, multiple modelling approaches, applied concurrently to a given problem, can help develop an integrative

  19. Petri Net Modeling of the Brain Circuit Involved in Aggressive Behavior

    OpenAIRE

    Moreno, Carlos B.; Díaz, José-Luis; Martínez, J. H.

    2015-01-01

    The purpose of this work in to demonstrate the initial results of a research project having as its goal to develop dynamic models of the brain network involved in aggressive behavior. In this way, the complex neural process correlated to basic anger emotions and resulting in aggressive behaviors is purportedly schematized by the use of Petri nets, a work-flow computational tool. Initially, the modeling technique is introduced taking into account the most recent and accepted notion of the neur...

  20. A numerical approach to investigate the stability of equilibria for structured population models

    NARCIS (Netherlands)

    Breda, D.; Diekmann, O.; Maset, S.; Vermiglio, R.

    2013-01-01

    We are interested in the asymptotic stability of equilibria of structured populations modelled in terms of systems ofVolterra functional equations coupled with delay differential equations. The standard approach based on studying the characteristic equation of the linearized system is often involved

  1. An Integrated Approach for the Numerical Modelling of the Spray Forming Process

    DEFF Research Database (Denmark)

    Hattel, Jesper; Thorborg, Jesper; Pryds, Nini;

    2003-01-01

    In this paper, an integrated approach for modelling the entire spray forming process is presented. The basis for the analysis is a recently developed model which extents previous studies and includes the interaction between an array of droplets and the enveloping gas. The formulation...... of the deposition is accomplished using a 3-D cylindrical heat flow model. This model is now coupled with an atomization model via a log-normal droplet size distribution. The coupling between the atomization and the deposition model is accomplished by ensuring that the total droplet size distribution of the spray...... is in fact the summation of "local" droplet size distributions along the r-axis. Furthermore, the deposition model proposed in the paper involves both the sticking efficiency of the droplets to the substrate as well as a geometrical model involving the effects of shadowing for the production of billet...

  2. Random matrix model approach to chiral symmetry

    CERN Document Server

    Verbaarschot, J J M

    1996-01-01

    We review the application of random matrix theory (RMT) to chiral symmetry in QCD. Starting from the general philosophy of RMT we introduce a chiral random matrix model with the global symmetries of QCD. Exact results are obtained for universal properties of the Dirac spectrum: i) finite volume corrections to valence quark mass dependence of the chiral condensate, and ii) microscopic fluctuations of Dirac spectra. Comparisons with lattice QCD simulations are made. Most notably, the variance of the number of levels in an interval containing $n$ levels on average is suppressed by a factor $(\\log n)/\\pi^2 n$. An extension of the random matrix model model to nonzero temperatures and chemical potential provides us with a schematic model of the chiral phase transition. In particular, this elucidates the nature of the quenched approximation at nonzero chemical potential.

  3. Machine Learning Approaches for Modeling Spammer Behavior

    CERN Document Server

    Islam, Md Saiful; Islam, Md Rafiqul

    2010-01-01

    Spam is commonly known as unsolicited or unwanted email messages in the Internet causing potential threat to Internet Security. Users spend a valuable amount of time deleting spam emails. More importantly, ever increasing spam emails occupy server storage space and consume network bandwidth. Keyword-based spam email filtering strategies will eventually be less successful to model spammer behavior as the spammer constantly changes their tricks to circumvent these filters. The evasive tactics that the spammer uses are patterns and these patterns can be modeled to combat spam. This paper investigates the possibilities of modeling spammer behavioral patterns by well-known classification algorithms such as Na\\"ive Bayesian classifier (Na\\"ive Bayes), Decision Tree Induction (DTI) and Support Vector Machines (SVMs). Preliminary experimental results demonstrate a promising detection rate of around 92%, which is considerably an enhancement of performance compared to similar spammer behavior modeling research.

  4. Infectious disease modeling a hybrid system approach

    CERN Document Server

    Liu, Xinzhi

    2017-01-01

    This volume presents infectious diseases modeled mathematically, taking seasonality and changes in population behavior into account, using a switched and hybrid systems framework. The scope of coverage includes background on mathematical epidemiology, including classical formulations and results; a motivation for seasonal effects and changes in population behavior, an investigation into term-time forced epidemic models with switching parameters, and a detailed account of several different control strategies. The main goal is to study these models theoretically and to establish conditions under which eradication or persistence of the disease is guaranteed. In doing so, the long-term behavior of the models is determined through mathematical techniques from switched systems theory. Numerical simulations are also given to augment and illustrate the theoretical results and to help study the efficacy of the control schemes.

  5. Second Quantization Approach to Stochastic Epidemic Models

    CERN Document Server

    Mondaini, Leonardo

    2015-01-01

    We show how the standard field theoretical language based on creation and annihilation operators may be used for a straightforward derivation of closed master equations describing the population dynamics of multivariate stochastic epidemic models. In order to do that, we introduce an SIR-inspired stochastic model for hepatitis C virus epidemic, from which we obtain the time evolution of the mean number of susceptible, infected, recovered and chronically infected individuals in a population whose total size is allowed to change.

  6. Predicting Preschoolers' Attachment Security from Fathers' Involvement, Internal Working Models, and Use of Social Support

    Science.gov (United States)

    Newland, Lisa A.; Coyl, Diana D.; Freeman, Harry

    2008-01-01

    Associations between preschoolers' attachment security, fathers' involvement (i.e. parenting behaviors and consistency) and fathering context (i.e. fathers' internal working models (IWMs) and use of social support) were examined in a subsample of 102 fathers, taken from a larger sample of 235 culturally diverse US families. The authors predicted…

  7. Helpful Components Involved in the Cognitive-Experiential Model of Dream Work

    Science.gov (United States)

    Tien, Hsiu-Lan Shelley; Chen, Shuh-Chi; Lin, Chia-Huei

    2009-01-01

    The purpose of the study was to examine the helpful components involved in the Hill's cognitive-experiential dream work model. Participants were 27 volunteer clients from colleges and universities in northern and central parts of Taiwan. Each of the clients received 1-2 sessions of dream interpretations. The cognitive-experiential dream work model…

  8. "Dispersion modeling approaches for near road | Science ...

    Science.gov (United States)

    Roadway design and roadside barriers can have significant effects on the dispersion of traffic-generated pollutants, especially in the near-road environment. Dispersion models that can accurately simulate these effects are needed to fully assess these impacts for a variety of applications. For example, such models can be useful for evaluating the mitigation potential of roadside barriers in reducing near-road exposures and their associated adverse health effects. Two databases, a tracer field study and a wind tunnel study, provide measurements used in the development and/or validation of algorithms to simulate dispersion in the presence of noise barriers. The tracer field study was performed in Idaho Falls, ID, USA with a 6-m noise barrier and a finite line source in a variety of atmospheric conditions. The second study was performed in the meteorological wind tunnel at the US EPA and simulated line sources at different distances from a model noise barrier to capture the effect on emissions from individual lanes of traffic. In both cases, velocity and concentration measurements characterized the effect of the barrier on dispersion.This paper presents comparisons with the two datasets of the barrier algorithms implemented in two different dispersion models: US EPA’s R-LINE (a research dispersion modelling tool under development by the US EPA’s Office of Research and Development) and CERC’s ADMS model (ADMS-Urban). In R-LINE the physical features reveal

  9. Flipped models in Trinification: A Comprehensive Approach

    CERN Document Server

    Rodríguez, Oscar; Ponce, William A; Rojas, Eduardo

    2016-01-01

    By considering the 3-3-1 and the left-right symmetric models as low energy effective theories of the trinification group, alternative versions of these models are found. The new neutral gauge bosons in the universal 3-3-1 model and its flipped versions are considered; also, the left-right symmetric model and the two flipped variants of it are also studied. For these models, the couplings of the $Z'$ bosons to the standard model fermions are reported. The explicit form of the null space of the vector boson mass matrix for an arbitrary Higgs tensor and gauge group is also presented. In the general framework of the trinification gauge group, and by using the LHC experimental results and EW precision data, limits on the $Z'$ mass and the mixing angle between $Z$ and the new gauge bosons $Z'$ are imposed. The general results call for very small mixing angles in the range $10^{-3}$ radians and $M_{Z'}$ > 2.5 TeV.

  10. Lightweight approach to model traceability in a CASE tool

    Science.gov (United States)

    Vileiniskis, Tomas; Skersys, Tomas; Pavalkis, Saulius; Butleris, Rimantas; Butkiene, Rita

    2017-07-01

    A term "model-driven" is not at all a new buzzword within the ranks of system development community. Nevertheless, the ever increasing complexity of model-driven approaches keeps fueling all kinds of discussions around this paradigm and pushes researchers forward to research and develop new and more effective ways to system development. With the increasing complexity, model traceability, and model management as a whole, becomes indispensable activities of model-driven system development process. The main goal of this paper is to present a conceptual design and implementation of a practical lightweight approach to model traceability in a CASE tool.

  11. Approaching models of nursing from a postmodernist perspective.

    Science.gov (United States)

    Lister, P

    1991-02-01

    This paper explores some questions about the use of models of nursing. These questions make various assumptions about the nature of models of nursing, in general and in particular. Underlying these assumptions are various philosophical positions which are explored through an introduction to postmodernist approaches in philosophical criticism. To illustrate these approaches, a critique of the Roper et al. model is developed, and more general attitudes towards models of nursing are examined. It is suggested that postmodernism offers a challenge to many of the assumptions implicit in models of nursing, and that a greater awareness of these assumptions should lead to nursing care being better informed where such models are in use.

  12. Manufacturing Excellence Approach to Business Performance Model

    Directory of Open Access Journals (Sweden)

    Jesus Cruz Alvarez

    2015-03-01

    Full Text Available Six Sigma, lean manufacturing, total quality management, quality control, and quality function deployment are the fundamental set of tools to enhance productivity in organizations. There is some research that outlines the benefit of each tool into a particular context of firm´s productivity, but not into a broader context of firm´s competitiveness that is achieved thru business performance. The aim of this theoretical research paper is to contribute to this mean and propose a manufacturing excellence approach that links productivity tools into a broader context of business performance.

  13. A Research Framework for Understanding the Practical Impact of Family Involvement in the Juvenile Justice System: The Juvenile Justice Family Involvement Model.

    Science.gov (United States)

    Walker, Sarah Cusworth; Bishop, Asia S; Pullmann, Michael D; Bauer, Grace

    2015-12-01

    Family involvement is recognized as a critical element of service planning for children's mental health, welfare and education. For the juvenile justice system, however, parents' roles in this system are complex due to youths' legal rights, public safety, a process which can legally position parents as plaintiffs, and a historical legacy of blaming parents for youth indiscretions. Three recent national surveys of juvenile justice-involved parents reveal that the current paradigm elicits feelings of stress, shame and distrust among parents and is likely leading to worse outcomes for youth, families and communities. While research on the impact of family involvement in the justice system is starting to emerge, the field currently has no organizing framework to guide a research agenda, interpret outcomes or translate findings for practitioners. We propose a research framework for family involvement that is informed by a comprehensive review and content analysis of current, published arguments for family involvement in juvenile justice along with a synthesis of family involvement efforts in other child-serving systems. In this model, family involvement is presented as an ascending, ordinal concept beginning with (1) exclusion, and moving toward climates characterized by (2) information-giving, (3) information-eliciting and (4) full, decision-making partnerships. Specific examples of how courts and facilities might align with these levels are described. Further, the model makes predictions for how involvement will impact outcomes at multiple levels with applications for other child-serving systems.

  14. A Bayesian Model Committee Approach to Forecasting Global Solar Radiation

    CERN Document Server

    Lauret, Philippe; Muselli, Marc; David, Mathieu; Diagne, Hadja; Voyant, Cyril

    2012-01-01

    This paper proposes to use a rather new modelling approach in the realm of solar radiation forecasting. In this work, two forecasting models: Autoregressive Moving Average (ARMA) and Neural Network (NN) models are combined to form a model committee. The Bayesian inference is used to affect a probability to each model in the committee. Hence, each model's predictions are weighted by their respective probability. The models are fitted to one year of hourly Global Horizontal Irradiance (GHI) measurements. Another year (the test set) is used for making genuine one hour ahead (h+1) out-of-sample forecast comparisons. The proposed approach is benchmarked against the persistence model. The very first results show an improvement brought by this approach.

  15. MDA based-approach for UML Models Complete Comparison

    CERN Document Server

    Chaouni, Samia Benabdellah; Mouline, Salma

    2011-01-01

    If a modeling task is distributed, it will frequently be necessary to integrate models developed by different team members. Problems occur in the models integration step and particularly, in the comparison phase of the integration. This issue had been discussed in several domains and various models. However, previous approaches have not correctly handled the semantic comparison. In the current paper, we provide a MDA-based approach for models comparison which aims at comparing UML models. We develop an hybrid approach which takes into account syntactic, semantic and structural comparison aspects. For this purpose, we use the domain ontology as well as other resources such as dictionaries. We propose a decision support system which permits the user to validate (or not) correspondences extracted in the comparison phase. For implementation, we propose an extension of the generic correspondence metamodel AMW in order to transform UML models to the correspondence model.

  16. A devolved model for public involvement in the field of mental health research: case study learning.

    Science.gov (United States)

    Moule, Pam; Davies, Rosie

    2016-12-01

    Patient and public involvement in all aspects of research is espoused and there is a continued interest in understanding its wider impact. Existing investigations have identified both beneficial outcomes and remaining issues. This paper presents the impact of public involvement in one case study led by a mental health charity conducted as part of a larger research project. The case study used a devolved model of working, contracting with service user-led organizations to maximize the benefits of local knowledge on the implementation of personalized budgets, support recruitment and local user-led organizations. To understand the processes and impact of public involvement in a devolved model of working with user-led organizations. Multiple data collection methods were employed throughout 2012. These included interviews with the researchers (n = 10) and research partners (n = 5), observation of two case study meetings and the review of key case study documentation. Analysis was conducted in NVivo10 using a coding framework developed following a literature review. Five key themes emerged from the data; Devolved model, Nature of involvement, Enabling factors, Implementation challenges and Impact. While there were some challenges of implementing the devolved model it is clear that our findings add to the growing understanding of the positive benefits research partners can bring to complex research. A devolved model can support the involvement of user-led organizations in research if there is a clear understanding of the underpinning philosophy and support mechanisms are in place. © 2015 The Authors. Health Expectations Published by John Wiley & Sons Ltd.

  17. An Approach to Computer Modeling of Geological Faults in 3D and an Application

    Institute of Scientific and Technical Information of China (English)

    ZHU Liang-feng; HE Zheng; PAN Xin; WU Xin-cai

    2006-01-01

    3D geological modeling, one of the most important applications in geosciences of 3D GIS, forms the basis and is a prerequisite for visualized representation and analysis of 3D geological data. Computer modeling of geological faults in 3D is currently a topical research area. Structural modeling techniques of complex geological entities containing reverse faults are discussed and a series of approaches are proposed. The geological concepts involved in computer modeling and visualization of geological fault in 3D are explained, the type of data of geological faults based on geological exploration is analyzed, and a normative database format for geological faults is designed. Two kinds of modeling approaches for faults are compared: a modeling technique of faults based on stratum recovery and a modeling technique of faults based on interpolation in subareas. A novel approach, called the Unified Modeling Technique for stratum and fault, is presented to solve the puzzling problems of reverse faults, syn-sedimentary faults and faults terminated within geological models. A case study of a fault model of bed rock in the Beijing Olympic Green District is presented in order to show the practical result of this method. The principle and the process of computer modeling of geological faults in 3D are discussed and a series of applied technical proposals established. It strengthens our profound comprehension of geological phenomena and the modeling approach, and establishes the basic techniques of 3D geological modeling for practical applications in the field of geosciences.

  18. A consortium approach to glass furnace modeling.

    Energy Technology Data Exchange (ETDEWEB)

    Chang, S.-L.; Golchert, B.; Petrick, M.

    1999-04-20

    Using computational fluid dynamics to model a glass furnace is a difficult task for any one glass company, laboratory, or university to accomplish. The task of building a computational model of the furnace requires knowledge and experience in modeling two dissimilar regimes (the combustion space and the liquid glass bath), along with the skill necessary to couple these two regimes. Also, a detailed set of experimental data is needed in order to evaluate the output of the code to ensure that the code is providing proper results. Since all these diverse skills are not present in any one research institution, a consortium was formed between Argonne National Laboratory, Purdue University, Mississippi State University, and five glass companies in order to marshal these skills into one three-year program. The objective of this program is to develop a fully coupled, validated simulation of a glass melting furnace that may be used by industry to optimize the performance of existing furnaces.

  19. Mixture modeling approach to flow cytometry data.

    Science.gov (United States)

    Boedigheimer, Michael J; Ferbas, John

    2008-05-01

    Flow Cytometry has become a mainstay technique for measuring fluorescent and physical attributes of single cells in a suspended mixture. These data are reduced during analysis using a manual or semiautomated process of gating. Despite the need to gate data for traditional analyses, it is well recognized that analyst-to-analyst variability can impact the dataset. Moreover, cells of interest can be inadvertently excluded from the gate, and relationships between collected variables may go unappreciated because they were not included in the original analysis plan. A multivariate non-gating technique was developed and implemented that accomplished the same goal as traditional gating while eliminating many weaknesses. The procedure was validated against traditional gating for analysis of circulating B cells in normal donors (n = 20) and persons with Systemic Lupus Erythematosus (n = 42). The method recapitulated relationships in the dataset while providing for an automated and objective assessment of the data. Flow cytometry analyses are amenable to automated analytical techniques that are not predicated on discrete operator-generated gates. Such alternative approaches can remove subjectivity in data analysis, improve efficiency and may ultimately enable construction of large bioinformatics data systems for more sophisticated approaches to hypothesis testing.

  20. BUSINESS MODEL IN ELECTRICITY INDUSTRY USING BUSINESS MODEL CANVAS APPROACH; THE CASE OF PT. XYZ

    National Research Council Canada - National Science Library

    Wicaksono, Achmad Arief; Syarief, Rizal; Suparno, Ono

    2017-01-01

    .... This study aims to identify company's business model using Business Model Canvas approach, formulate business development strategy alternatives, and determine the prioritized business development...

  1. Computational approach for identification of Anopheles gambiae miRNA involved in modulation of host immune response.

    Science.gov (United States)

    Thirugnanasambantham, Krishnaraj; Hairul-Islam, Villianur Ibrahim; Saravanan, Subramanian; Subasri, Subramaniyan; Subastri, Ariraman

    2013-05-01

    MicroRNAs (miRNAs) are small, noncoding RNAs that play key roles in regulating gene expression in animals, plants, and viruses, which involves in biological processes including development, cancer, immunity, and host-microorganism interactions. In this present study, we have used the computational approach to identify potent miRNAs involved in Anopheles gambiae immune response. Analysis of 217,261 A. gambiae ESTs and further study of RNA folding revealed six new miRNAs. The minimum free energy of the predicted miRNAs ranged from -27.2 to -62.63 kcal/mol with an average of -49.38 kcal/mol. While its A + U % ranges from 50 to 65 % with an average value of 57.37 %. Phylogenetic analysis of the predicted miRNAs revealed that aga-miR-277 was evolutionary highly conserved with more similarity with other mosquito species. Observing further the target identification of the predicted miRNA, it was noticed that the aga-miR-2304 and aga-miR-2390 are involved in modulation of immune response by targeting the gene encoding suppressin and protein prophenoloxidase. Further detailed studies of these miRNAs will help in revealing its function in modulation of A. gambiae immune response with respect to its parasite.

  2. "Dispersion modeling approaches for near road

    Science.gov (United States)

    Roadway design and roadside barriers can have significant effects on the dispersion of traffic-generated pollutants, especially in the near-road environment. Dispersion models that can accurately simulate these effects are needed to fully assess these impacts for a variety of app...

  3. and Models: A Self-Similar Approach

    Directory of Open Access Journals (Sweden)

    José Antonio Belinchón

    2013-01-01

    equations (FEs admit self-similar solutions. The methods employed allow us to obtain general results that are valid not only for the FRW metric, but also for all the Bianchi types as well as for the Kantowski-Sachs model (under the self-similarity hypothesis and the power-law hypothesis for the scale factors.

  4. Nonperturbative approach to the modified statistical model

    Energy Technology Data Exchange (ETDEWEB)

    Magdy, M.A.; Bekmezci, A.; Sever, R. [Middle East Technical Univ., Ankara (Turkey)

    1993-12-01

    The modified form of the statistical model is used without making any perturbation. The mass spectra of the lowest S, P and D levels of the (Q{bar Q}) and the non-self-conjugate (Q{bar q}) mesons are studied with the Song-Lin potential. The authors results are in good agreement with the experimental and theoretical findings.

  5. System Behavior Models: A Survey of Approaches

    Science.gov (United States)

    2016-06-01

    Mandana Vaziri, and Frank Tip. 2007. “Finding Bugs Efficiently with a SAT Solver.” In European Software Engineering Conference and the ACM SIGSOFT...Van Gorp. 2005. “A Taxonomy of Model Transformation.” Electronic Notes in Theoretical Computer Science 152: 125–142. Miyazawa, Alvaro, and Ana

  6. A moving approach for the Vector Hysteron Model

    Energy Technology Data Exchange (ETDEWEB)

    Cardelli, E. [Department of Engineering, University of Perugia, Via G. Duranti 93, 06125 Perugia (Italy); Faba, A., E-mail: antonio.faba@unipg.it [Department of Engineering, University of Perugia, Via G. Duranti 93, 06125 Perugia (Italy); Laudani, A. [Department of Engineering, Roma Tre University, Via V. Volterra 62, 00146 Rome (Italy); Quondam Antonio, S. [Department of Engineering, University of Perugia, Via G. Duranti 93, 06125 Perugia (Italy); Riganti Fulginei, F.; Salvini, A. [Department of Engineering, Roma Tre University, Via V. Volterra 62, 00146 Rome (Italy)

    2016-04-01

    A moving approach for the VHM (Vector Hysteron Model) is here described, to reconstruct both scalar and rotational magnetization of electrical steels with weak anisotropy, such as the non oriented grain Silicon steel. The hysterons distribution is postulated to be function of the magnetization state of the material, in order to overcome the practical limitation of the congruency property of the standard VHM approach. By using this formulation and a suitable accommodation procedure, the results obtained indicate that the model is accurate, in particular in reproducing the experimental behavior approaching to the saturation region, allowing a real improvement respect to the previous approach.

  7. Integration models: multicultural and liberal approaches confronted

    Science.gov (United States)

    Janicki, Wojciech

    2012-01-01

    European societies have been shaped by their Christian past, upsurge of international migration, democratic rule and liberal tradition rooted in religious tolerance. Boosting globalization processes impose new challenges on European societies, striving to protect their diversity. This struggle is especially clearly visible in case of minorities trying to resist melting into mainstream culture. European countries' legal systems and cultural policies respond to these efforts in many ways. Respecting identity politics-driven group rights seems to be the most common approach, resulting in creation of a multicultural society. However, the outcome of respecting group rights may be remarkably contradictory to both individual rights growing out from liberal tradition, and to reinforced concept of integration of immigrants into host societies. The hereby paper discusses identity politics upturn in the context of both individual rights and integration of European societies.

  8. ISM Approach to Model Offshore Outsourcing Risks

    Directory of Open Access Journals (Sweden)

    Sunand Kumar

    2014-07-01

    Full Text Available In an effort to achieve a competitive advantage via cost reductions and improved market responsiveness, organizations are increasingly employing offshore outsourcing as a major component of their supply chain strategies. But as evident from literature number of risks such as Political risk, Risk due to cultural differences, Compliance and regulatory risk, Opportunistic risk and Organization structural risk, which adversely affect the performance of offshore outsourcing in a supply chain network. This also leads to dissatisfaction among different stake holders. The main objective of this paper is to identify and understand the mutual interaction among various risks which affect the performance of offshore outsourcing.  To this effect, authors have identified various risks through extant review of literature.  From this information, an integrated model using interpretive structural modelling (ISM for risks affecting offshore outsourcing is developed and the structural relationships between these risks are modeled.  Further, MICMAC analysis is done to analyze the driving power and dependency of risks which shall be helpful to managers to identify and classify important criterions and to reveal the direct and indirect effects of each criterion on offshore outsourcing. Results show that political risk and risk due to cultural differences are act as strong drivers.

  9. The "Commitment Model" for Clinical Ethics Consultations: Society's Involvement in the Solution of Individual Cases.

    Science.gov (United States)

    Fournier, Véronique; Spranzi, Marta; Foureur, Nicolas; Brunet, Laurence

    2015-01-01

    Several approaches to clinical ethics consultation (CEC) exist in medical practice and are widely discussed in the clinical ethics literature; different models of CECs are classified according to their methods, goals, and consultant's attitude. Although the "facilitation" model has been endorsed by the American Society for Bioethics and Humanities (ASBH) and is described in an influential manual, alternative approaches, such as advocacy, moral expertise, mediation, and engagement are practiced and defended in the clinical ethics field. Our Clinical Ethics Center in Paris was founded in 2002 in the wake of the Patients' Rights Act, and to date it is the largest center that provides consultation services in France. In this article we shall describe and defend our own approach to clinical ethics consultation, which we call the "Commitment Model," in comparison with other existing models. Indeed commitment implies, among other meanings, continuity through time, a series of coherent actions, and the realization of important social goals. By drawing on a recent consultation case, we shall describe the main steps of our consultation procedure: interviews with major stakeholders, including patients and proxies; case conferences; and follow up. We shall show why we have chosen the term "commitment" to represent our approach at three different but interrelated levels: commitment towards patients, within the case conference group, and towards society as a whole.

  10. Quantum Machine and SR Approach: a Unified Model

    CERN Document Server

    Garola, C; Sozzo, S; Garola, Claudio; Pykacz, Jaroslav; Sozzo, Sandro

    2005-01-01

    The Geneva-Brussels approach to quantum mechanics (QM) and the semantic realism (SR) nonstandard interpretation of QM exhibit some common features and some deep conceptual differences. We discuss in this paper two elementary models provided in the two approaches as intuitive supports to general reasonings and as a proof of consistency of general assumptions, and show that Aerts' quantum machine can be embodied into a macroscopic version of the microscopic SR model, overcoming the seeming incompatibility between the two models. This result provides some hints for the construction of a unified perspective in which the two approaches can be properly placed.

  11. Dynamic Metabolic Model Building Based on the Ensemble Modeling Approach

    Energy Technology Data Exchange (ETDEWEB)

    Liao, James C. [Univ. of California, Los Angeles, CA (United States)

    2016-10-01

    Ensemble modeling of kinetic systems addresses the challenges of kinetic model construction, with respect to parameter value selection, and still allows for the rich insights possible from kinetic models. This project aimed to show that constructing, implementing, and analyzing such models is a useful tool for the metabolic engineering toolkit, and that they can result in actionable insights from models. Key concepts are developed and deliverable publications and results are presented.

  12. A modular approach to numerical human body modeling

    NARCIS (Netherlands)

    Forbes, P.A.; Griotto, G.; Rooij, L. van

    2007-01-01

    The choice of a human body model for a simulated automotive impact scenario must take into account both accurate model response and computational efficiency as key factors. This study presents a "modular numerical human body modeling" approach which allows the creation of a customized human body mod

  13. A BEHAVIORAL-APPROACH TO LINEAR EXACT MODELING

    NARCIS (Netherlands)

    ANTOULAS, AC; WILLEMS, JC

    1993-01-01

    The behavioral approach to system theory provides a parameter-free framework for the study of the general problem of linear exact modeling and recursive modeling. The main contribution of this paper is the solution of the (continuous-time) polynomial-exponential time series modeling problem. Both re

  14. A modular approach to numerical human body modeling

    NARCIS (Netherlands)

    Forbes, P.A.; Griotto, G.; Rooij, L. van

    2007-01-01

    The choice of a human body model for a simulated automotive impact scenario must take into account both accurate model response and computational efficiency as key factors. This study presents a "modular numerical human body modeling" approach which allows the creation of a customized human body

  15. A market model for stochastic smile: a conditional density approach

    NARCIS (Netherlands)

    Zilber, A.

    2005-01-01

    The purpose of this paper is to introduce a new approach that allows to construct no-arbitrage market models of for implied volatility surfaces (in other words, stochastic smile models). That is to say, the idea presented here allows us to model prices of liquidly traded vanilla options as separate

  16. Thermoplasmonics modeling: A Green's function approach

    Science.gov (United States)

    Baffou, Guillaume; Quidant, Romain; Girard, Christian

    2010-10-01

    We extend the discrete dipole approximation (DDA) and the Green’s dyadic tensor (GDT) methods—previously dedicated to all-optical simulations—to investigate the thermodynamics of illuminated plasmonic nanostructures. This extension is based on the use of the thermal Green’s function and a original algorithm that we named Laplace matrix inversion. It allows for the computation of the steady-state temperature distribution throughout plasmonic systems. This hybrid photothermal numerical method is suited to investigate arbitrarily complex structures. It can take into account the presence of a dielectric planar substrate and is simple to implement in any DDA or GDT code. Using this numerical framework, different applications are discussed such as thermal collective effects in nanoparticles assembly, the influence of a substrate on the temperature distribution and the heat generation in a plasmonic nanoantenna. This numerical approach appears particularly suited for new applications in physics, chemistry, and biology such as plasmon-induced nanochemistry and catalysis, nanofluidics, photothermal cancer therapy, or phase-transition control at the nanoscale.

  17. Participatory approaches involving community and healthcare providers in family planning/contraceptive information and service provision: a scoping review.

    Science.gov (United States)

    Steyn, Petrus S; Cordero, Joanna Paula; Gichangi, Peter; Smit, Jennifer A; Nkole, Theresa; Kiarie, James; Temmerman, Marleen

    2016-07-22

    As efforts to address unmet need for family planning and contraception (FP/C) accelerate, voluntary use, informed choice and quality must remain at the fore. Active involvement of affected populations has been recognized as one of the key principles in ensuring human rights in the provision of FP/C and in improving quality of care. However, community participation continues to be inadequately addressed in large-scale FP/C programmes. Community and healthcare providers' unequal relationship can be a barrier to successful participation. This scoping review identifies participatory approaches involving both community and healthcare providers for FP/C services and analyzes relevant evidence. The detailed analysis of 25 articles provided information on 28 specific programmes and identified three types of approaches for community and healthcare provider participation in FP/C programmes. The three approaches were: (i) establishment of new groups either health committees to link the health service providers and users or implementation teams to conduct specific activities to improve or extend available health services, (ii) identification of and collaboration with existing community structures to optimise use of health services and (iii) operationalization of tools to facilitate community and healthcare provider collaboration for quality improvement. Integration of community and healthcare provider participation in FP/C provision were conducted through FP/C-only programmes, FP/C-focused programmes and/or as part of a health service package. The rationales behind the interventions varied and may be multiple. Examples include researcher-, NGO- or health service-initiated programmes with clear objectives of improving FP/C service provision or increasing demand for services; facilitating the involvement of community members or service users and, in some cases, may combine socio-economic development and increasing self-reliance or control over sexual and reproductive health

  18. Opioid receptor types involved in the development of nicotine physical dependence in an invertebrate (Planaria) model.

    Science.gov (United States)

    Raffa, Robert B; Baron, Steve; Bhandal, Jaspreet S; Brown, Tevin; Song, Kevin; Tallarida, Christopher S; Rawls, Scott M

    2013-11-01

    Recent data suggest that opioid receptors are involved in the development of nicotine physical dependence in mammals. Evidence in support of a similar involvement in an invertebrate (Planaria) is presented using the selective opioid receptor antagonist naloxone, and the more receptor subtype-selective antagonists CTAP (D-Phe-Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH2) (μ, MOR), naltrindole (δ, DOR), and nor-BNI (norbinaltorphimine) (κ, KOR). Induction of physical dependence was achieved by 60-min pre-exposure of planarians to nicotine and was quantified by abstinence-induced withdrawal (reduction in spontaneous locomotor activity). Known MOR and DOR subtype-selective opioid receptor antagonists attenuated the withdrawal, as did the non-selective antagonist naloxone, but a KOR subtype-selective antagonist did not. An involvement of MOR and DOR, but not KOR, in the development of nicotine physical dependence or in abstinence-induced withdrawal was thus demonstrated in a sensitive and facile invertebrate model.

  19. Agribusiness model approach to territorial food development

    Directory of Open Access Journals (Sweden)

    Murcia Hector Horacio

    2011-04-01

    Full Text Available

    Several research efforts have coordinated the academic program of Agricultural Business Management from the University De La Salle (Bogota D.C., to the design and implementation of a sustainable agribusiness model applied to food development, with territorial projection. Rural development is considered as a process that aims to improve the current capacity and potential of the inhabitant of the sector, which refers not only to production levels and productivity of agricultural items. It takes into account the guidelines of the Organization of the United Nations “Millennium Development Goals” and considered the concept of sustainable food and agriculture development, including food security and nutrition in an integrated interdisciplinary context, with holistic and systemic dimension. Analysis is specified by a model with an emphasis on sustainable agribusiness production chains related to agricultural food items in a specific region. This model was correlated with farm (technical objectives, family (social purposes and community (collective orientations projects. Within this dimension are considered food development concepts and methodologies of Participatory Action Research (PAR. Finally, it addresses the need to link the results to low-income communities, within the concepts of the “new rurality”.

  20. Coupling approaches used in atmospheric entry models

    Science.gov (United States)

    Gritsevich, M. I.

    2012-09-01

    While a planet orbits the Sun, it is subject to impact by smaller objects, ranging from tiny dust particles and space debris to much larger asteroids and comets. Such collisions have taken place frequently over geological time and played an important role in the evolution of planets and the development of life on the Earth. Though the search for near-Earth objects addresses one of the main points of the Asteroid and Comet Hazard, one should not underestimate the useful information to be gleaned from smaller atmospheric encounters, known as meteors or fireballs. Not only do these events help determine the linkages between meteorites and their parent bodies; due to their relative regularity they provide a good statistical basis for analysis. For successful cases with found meteorites, the detailed atmospheric path record is an excellent tool to test and improve existing entry models assuring the robustness of their implementation. There are many more important scientific questions meteoroids help us to answer, among them: Where do these objects come from, what are their origins, physical properties and chemical composition? What are the shapes and bulk densities of the space objects which fully ablate in an atmosphere and do not reach the planetary surface? Which values are directly measured and which are initially assumed as input to various models? How to couple both fragmentation and ablation effects in the model, taking real size distribution of fragments into account? How to specify and speed up the recovery of a recently fallen meteorites, not letting weathering to affect samples too much? How big is the pre-atmospheric projectile to terminal body ratio in terms of their mass/volume? Which exact parameters beside initial mass define this ratio? More generally, how entering object affects Earth's atmosphere and (if applicable) Earth's surface? How to predict these impact consequences based on atmospheric trajectory data? How to describe atmospheric entry

  1. A homology model of Xyloglucan Xylosyltransferase 2 reveals critical amino acids involved in substrate binding.

    Science.gov (United States)

    Culbertson, Alan T; Tietze, Alesia A; Tietze, Daniel; Chou, Yi-Hsiang; Smith, Adrienne L; Young, Zachary T; Zabotina, Olga A

    2016-09-01

    In dicotyledonous plants, xyloglucan (XyG) is the most abundant hemicellulose of the primary cell wall. The enzymes involved in XyG biosynthesis have been identified through reverse-genetics and activity was characterized by heterologous expression. Currently, there is no information on the atomic structures or amino acids involved in activity or substrate binding of any of the Golgi-localized XyG biosynthetic enzymes. A homology model of the xyloglucan xylosyltransferase 2 (XXT2) catalytic domain was built on the basis of the crystal structure of A64Rp. Molecular dynamics simulations revealed that the homology model retains the glycosyltransferase (GT)-A fold of the template structure used to build the homology model indicating that XXT2 likely has a GT-A fold. According to the XXT2 homology model, six amino acids (Phe204, Lys207, Asp228, Ser229, Asp230, His378) were selected and their contribution in catalytic activity was investigated. Site-directed mutagenesis studies show that Asp228, Asp230 and His378 are critical for XXT2 activity and are predicted to be involved in coordination of manganese ion. Lys207 was also found to be critical for protein activity and the homology model indicates a critical role in substrate binding. Additionally, Phe204 mutants have less of an impact on XXT2 activity with the largest effect when replaced with a polar residue. This is the first study that investigates the amino acids involved in substrate binding of the XyG-synthesizing xylosyltransferases and contributes to the understanding of the mechanisms of polysaccharide-synthesizing GTs and XyG biosynthesis. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  2. Applied Regression Modeling A Business Approach

    CERN Document Server

    Pardoe, Iain

    2012-01-01

    An applied and concise treatment of statistical regression techniques for business students and professionals who have little or no background in calculusRegression analysis is an invaluable statistical methodology in business settings and is vital to model the relationship between a response variable and one or more predictor variables, as well as the prediction of a response value given values of the predictors. In view of the inherent uncertainty of business processes, such as the volatility of consumer spending and the presence of market uncertainty, business professionals use regression a

  3. Bayesian Approach to Neuro-Rough Models for Modelling HIV

    CERN Document Server

    Marwala, Tshilidzi

    2007-01-01

    This paper proposes a new neuro-rough model for modelling the risk of HIV from demographic data. The model is formulated using Bayesian framework and trained using Markov Chain Monte Carlo method and Metropolis criterion. When the model was tested to estimate the risk of HIV infection given the demographic data it was found to give the accuracy of 62% as opposed to 58% obtained from a Bayesian formulated rough set model trained using Markov chain Monte Carlo method and 62% obtained from a Bayesian formulated multi-layered perceptron (MLP) model trained using hybrid Monte. The proposed model is able to combine the accuracy of the Bayesian MLP model and the transparency of Bayesian rough set model.

  4. Development of a computationally efficient urban modeling approach

    DEFF Research Database (Denmark)

    Wolfs, Vincent; Murla, Damian; Ntegeka, Victor;

    2016-01-01

    This paper presents a parsimonious and data-driven modelling approach to simulate urban floods. Flood levels simulated by detailed 1D-2D hydrodynamic models can be emulated using the presented conceptual modelling approach with a very short calculation time. In addition, the model detail can...... be adjust-ed, allowing the modeller to focus on flood-prone locations. This results in efficiently parameterized models that can be tailored to applications. The simulated flood levels are transformed into flood extent maps using a high resolution (0.5-meter) digital terrain model in GIS. To illustrate...... the developed methodology, a case study for the city of Ghent in Belgium is elaborated. The configured conceptual model mimics the flood levels of a detailed 1D-2D hydrodynamic InfoWorks ICM model accurately, while the calculation time is an order of magnitude of 106 times shorter than the original highly...

  5. A Multiscale Approach for Modeling Oxygen Production by Adsorption

    Directory of Open Access Journals (Sweden)

    Pavone D.

    2013-10-01

    Full Text Available Oxygen production processes using adsorbents for application to CCS technologies (Carbon Capture and Storage offer potential cost benefits over classical cryogenics. In order to model adsorption processes an approach using three size scales has been developed. This work is being conducted in the framework of the DECARBit European research project. The first scale is at the size of the oxygen adsorption bed to be modelled as a vertical cylinder filled with pellets. Its length is 0.2 m (scale 10-1 m. The bed is homogeneous in the transversal direction so that the problem is 1D (independent variables t, x. The physics in the process include gas species (Cbk (t, x convection and dispersion, thermal convection and conduction (T(t, x and hydrodynamics (v(t, x. The gas constituents involved are N2, 02, CO2 and H2O. The second scale is at the size of the pellets that fill the adsorber and which are assumed to be of spherical shape with a typical radius of 5 mm (scale 10-3 m. The independent variable for the pellets is the radius “rp”. At a certain height (x down in the adsorber all the pellets are the same and are surrounded by the same gas composition but inside the pellets the concentrations may vary. The state variables for the inner part of the pellets are the gas concentrations Cpk(t, x, rp. The pellets are so small that they are assumed to have a uniform temperature. This leads to a 2D transient model for the pellets linked to the 1D transient model for the bulk. The third scale looks into the detailed structure of the pellets that are made of perovskite crystallites. The latter are assumed to be spherical. Oxygen adsorption occurs in the crystallites which have a radius of about 0.5 pm (scale 10-7 m. All the crystallites at the same radius in a pellet are supposed to behave the same and because they are spherical, the only independent variable for a crystallite located at (x, rp is its radius “rc”. The state variables for the crystallites

  6. Implicit moral evaluations: A multinomial modeling approach.

    Science.gov (United States)

    Cameron, C Daryl; Payne, B Keith; Sinnott-Armstrong, Walter; Scheffer, Julian A; Inzlicht, Michael

    2017-01-01

    Implicit moral evaluations-i.e., immediate, unintentional assessments of the wrongness of actions or persons-play a central role in supporting moral behavior in everyday life. Yet little research has employed methods that rigorously measure individual differences in implicit moral evaluations. In five experiments, we develop a new sequential priming measure-the Moral Categorization Task-and a multinomial model that decomposes judgment on this task into multiple component processes. These include implicit moral evaluations of moral transgression primes (Unintentional Judgment), accurate moral judgments about target actions (Intentional Judgment), and a directional tendency to judge actions as morally wrong (Response Bias). Speeded response deadlines reduced Intentional Judgment but not Unintentional Judgment (Experiment 1). Unintentional Judgment was stronger toward moral transgression primes than non-moral negative primes (Experiments 2-4). Intentional Judgment was associated with increased error-related negativity, a neurophysiological indicator of behavioral control (Experiment 4). Finally, people who voted for an anti-gay marriage amendment had stronger Unintentional Judgment toward gay marriage primes (Experiment 5). Across Experiments 1-4, implicit moral evaluations converged with moral personality: Unintentional Judgment about wrong primes, but not negative primes, was negatively associated with psychopathic tendencies and positively associated with moral identity and guilt proneness. Theoretical and practical applications of formal modeling for moral psychology are discussed. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Continuous Molecular Fields Approach Applied to Structure-Activity Modeling

    CERN Document Server

    Baskin, Igor I

    2013-01-01

    The Method of Continuous Molecular Fields is a universal approach to predict various properties of chemical compounds, in which molecules are represented by means of continuous fields (such as electrostatic, steric, electron density functions, etc). The essence of the proposed approach consists in performing statistical analysis of functional molecular data by means of joint application of kernel machine learning methods and special kernels which compare molecules by computing overlap integrals of their molecular fields. This approach is an alternative to traditional methods of building 3D structure-activity and structure-property models based on the use of fixed sets of molecular descriptors. The methodology of the approach is described in this chapter, followed by its application to building regression 3D-QSAR models and conducting virtual screening based on one-class classification models. The main directions of the further development of this approach are outlined at the end of the chapter.

  8. The necessary burden of involving stakeholders in agent-based modelling for education and decision-making

    Science.gov (United States)

    Bommel, P.; Bautista Solís, P.; Leclerc, G.

    2016-12-01

    We implemented a participatory process with water stakeholders for improving resilience to drought at watershed scale, and for reducing water pollution disputes in drought prone Northwestern Costa Rica. The purpose is to facilitate co-management in a rural watershed impacted by recurrent droughts related to ENSO. The process involved designing "ContaMiCuenca", a hybrid agent-based model where users can specify the decisions of their agents. We followed a Companion Modeling approach (www.commod.org) and organized 10 workshops that included research techniques such as participatory diagnostics, actor-resources-interaction and UML diagrams, multi-agents model design, and interactive simulation sessions. We collectively assessed the main water issues in the watershed, prioritized their importance, defined the objectives of the process, and pilot-tested ContaMiCuenca for environmental education with adults and children. Simulation sessions resulted in debates about the need to improve the model accuracy, arguably more relevant for decision-making. This helped identify sensible knowledge gaps in the groundwater pollution and aquifer dynamics that need to be addressed in order to improve our collective learning. Significant mismatches among participants expectations, objectives, and agendas considerably slowed down the participatory process. The main issue may originate in participants expecting technical solutions from a positivist science, as constantly promoted in the region by dole-out initiatives, which is incompatible with the constructivist stance of participatory modellers. This requires much closer interaction of community members with modellers, which may be hard to attain in the current research practice and institutional context. Nevertheless, overcoming these constraints is necessary for a true involvement of water stakeholders to achieve community-based decisions that facilitate integrated water management. Our findings provide significant guidance for

  9. Degree of multicollinearity and variables involved in linear dependence in additive-dominant models

    Directory of Open Access Journals (Sweden)

    Juliana Petrini

    2012-12-01

    Full Text Available The objective of this work was to assess the degree of multicollinearity and to identify the variables involved in linear dependence relations in additive-dominant models. Data of birth weight (n=141,567, yearling weight (n=58,124, and scrotal circumference (n=20,371 of Montana Tropical composite cattle were used. Diagnosis of multicollinearity was based on the variance inflation factor (VIF and on the evaluation of the condition indexes and eigenvalues from the correlation matrix among explanatory variables. The first model studied (RM included the fixed effect of dam age class at calving and the covariates associated to the direct and maternal additive and non-additive effects. The second model (R included all the effects of the RM model except the maternal additive effects. Multicollinearity was detected in both models for all traits considered, with VIF values of 1.03 - 70.20 for RM and 1.03 - 60.70 for R. Collinearity increased with the increase of variables in the model and the decrease in the number of observations, and it was classified as weak, with condition index values between 10.00 and 26.77. In general, the variables associated with additive and non-additive effects were involved in multicollinearity, partially due to the natural connection between these covariables as fractions of the biological types in breed composition.

  10. Portraiture of constructivist parental involvement: A model to develop a community of practice

    Science.gov (United States)

    Dignam, Christopher Anthony

    This qualitative research study addressed the problem of the lack of parental involvement in secondary school science. Increasing parental involvement is vital in supporting student academic achievement and social growth. The purpose of this emergent phenomenological study was to identify conditions required to successfully construct a supportive learning environment to form partnerships between students, parents, and educators. The overall research question in this study investigated the conditions necessary to successfully enlist parental participation with students during science inquiry investigations at the secondary school level. One hundred thirteen pairs of parents and students engaged in a 6-week scientific inquiry activity and recorded attitudinal data in dialogue journals, questionnaires, open-ended surveys, and during one-one-one interviews conducted by the researcher between individual parents and students. Comparisons and cross-interpretations of inter-rater, codified, triangulated data were utilized for identifying emergent themes. Data analysis revealed the active involvement of parents in researching with their child during inquiry investigations, engaging in journaling, and assessing student performance fostered partnerships among students, parents, and educators and supported students' social skills development. The resulting model, employing constructivist leadership and enlisting parent involvement, provides conditions and strategies required to develop a community of practice that can help effect social change. The active involvement of parents fostered improved efficacy and a holistic mindset to develop in parents, students, and teachers. Based on these findings, the interactive collaboration of parents in science learning activities can proactively facilitate a community of practice that will assist educators in facilitating social change.

  11. Genetic Algorithm Approaches to Prebiobiotic Chemistry Modeling

    Science.gov (United States)

    Lohn, Jason; Colombano, Silvano

    1997-01-01

    We model an artificial chemistry comprised of interacting polymers by specifying two initial conditions: a distribution of polymers and a fixed set of reversible catalytic reactions. A genetic algorithm is used to find a set of reactions that exhibit a desired dynamical behavior. Such a technique is useful because it allows an investigator to determine whether a specific pattern of dynamics can be produced, and if it can, the reaction network found can be then analyzed. We present our results in the context of studying simplified chemical dynamics in theorized protocells - hypothesized precursors of the first living organisms. Our results show that given a small sample of plausible protocell reaction dynamics, catalytic reaction sets can be found. We present cases where this is not possible and also analyze the evolved reaction sets.

  12. Modeling Approaches for Describing Microbial Population Heterogeneity

    DEFF Research Database (Denmark)

    Lencastre Fernandes, Rita

    , ethanol and biomass throughout the reactor. This work has proven that the integration of CFD and population balance models, for describing the growth of a microbial population in a spatially heterogeneous reactor, is feasible, and that valuable insight on the interplay between flow and the dynamics......Although microbial populations are typically described by averaged properties, individual cells present a certain degree of variability. Indeed, initially clonal microbial populations develop into heterogeneous populations, even when growing in a homogeneous environment. A heterogeneous microbial......) to predict distributions of certain population properties including particle size, mass or volume, and molecular weight. Similarly, PBM allow for a mathematical description of distributed cell properties within microbial populations. Cell total protein content distributions (a measure of cell mass) have been...

  13. Hamiltonian approach to hybrid plasma models

    CERN Document Server

    Tronci, Cesare

    2010-01-01

    The Hamiltonian structures of several hybrid kinetic-fluid models are identified explicitly, upon considering collisionless Vlasov dynamics for the hot particles interacting with a bulk fluid. After presenting different pressure-coupling schemes for an ordinary fluid interacting with a hot gas, the paper extends the treatment to account for a fluid plasma interacting with an energetic ion species. Both current-coupling and pressure-coupling MHD schemes are treated extensively. In particular, pressure-coupling schemes are shown to require a transport-like term in the Vlasov kinetic equation, in order for the Hamiltonian structure to be preserved. The last part of the paper is devoted to studying the more general case of an energetic ion species interacting with a neutralizing electron background (hybrid Hall-MHD). Circulation laws and Casimir functionals are presented explicitly in each case.

  14. Modeling of phase equilibria with CPA using the homomorph approach

    DEFF Research Database (Denmark)

    Breil, Martin Peter; Tsivintzelis, Ioannis; Kontogeorgis, Georgios

    2011-01-01

    For association models, like CPA and SAFT, a classical approach is often used for estimating pure-compound and mixture parameters. According to this approach, the pure-compound parameters are estimated from vapor pressure and liquid density data. Then, the binary interaction parameters, kij, are ...

  15. A Constructive Neural-Network Approach to Modeling Psychological Development

    Science.gov (United States)

    Shultz, Thomas R.

    2012-01-01

    This article reviews a particular computational modeling approach to the study of psychological development--that of constructive neural networks. This approach is applied to a variety of developmental domains and issues, including Piagetian tasks, shift learning, language acquisition, number comparison, habituation of visual attention, concept…

  16. A Constructive Neural-Network Approach to Modeling Psychological Development

    Science.gov (United States)

    Shultz, Thomas R.

    2012-01-01

    This article reviews a particular computational modeling approach to the study of psychological development--that of constructive neural networks. This approach is applied to a variety of developmental domains and issues, including Piagetian tasks, shift learning, language acquisition, number comparison, habituation of visual attention, concept…

  17. Modular Modelling and Simulation Approach - Applied to Refrigeration Systems

    DEFF Research Database (Denmark)

    Sørensen, Kresten Kjær; Stoustrup, Jakob

    2008-01-01

    This paper presents an approach to modelling and simulation of the thermal dynamics of a refrigeration system, specifically a reefer container. A modular approach is used and the objective is to increase the speed and flexibility of the developed simulation environment. The refrigeration system...

  18. Pattern-based approach for logical traffic isolation forensic modelling

    CSIR Research Space (South Africa)

    Dlamini, I

    2009-08-01

    Full Text Available The use of design patterns usually changes the approach of software design and makes software development relatively easy. This paper extends work on a forensic model for Logical Traffic Isolation (LTI) based on Differentiated Services (Diff...

  19. A semantic-web approach for modeling computing infrastructures

    NARCIS (Netherlands)

    M. Ghijsen; J. van der Ham; P. Grosso; C. Dumitru; H. Zhu; Z. Zhao; C. de Laat

    2013-01-01

    This paper describes our approach to modeling computing infrastructures. Our main contribution is the Infrastructure and Network Description Language (INDL) ontology. The aim of INDL is to provide technology independent descriptions of computing infrastructures, including the physical resources as w

  20. Bayesian approach to decompression sickness model parameter estimation.

    Science.gov (United States)

    Howle, L E; Weber, P W; Nichols, J M

    2017-03-01

    We examine both maximum likelihood and Bayesian approaches for estimating probabilistic decompression sickness model parameters. Maximum likelihood estimation treats parameters as fixed values and determines the best estimate through repeated trials, whereas the Bayesian approach treats parameters as random variables and determines the parameter probability distributions. We would ultimately like to know the probability that a parameter lies in a certain range rather than simply make statements about the repeatability of our estimator. Although both represent powerful methods of inference, for models with complex or multi-peaked likelihoods, maximum likelihood parameter estimates can prove more difficult to interpret than the estimates of the parameter distributions provided by the Bayesian approach. For models of decompression sickness, we show that while these two estimation methods are complementary, the credible intervals generated by the Bayesian approach are more naturally suited to quantifying uncertainty in the model parameters.

  1. Involving the elderly in the design process: a participatory design model for usability, safety and attractiveness

    OpenAIRE

    Demirbilek, Oya

    1999-01-01

    Ankara : Institute of Economics and Social Sciences of Bilkent University, 1999. Thesis (Ph.D.) -- Bilkent University, 1999 Includes bibliographical references leaves 113-131 This work presents a conceptual model involving the elderly users into the design process by means of participatory design sessions, where the expertise of designers and the real requirements and opinions of elderly end-users, related to how objects, environments and equipment should be designed to allow ageing ...

  2. Semi-Implicit Algorithm for Elastoplastic Damage Models Involving Energy Integration

    OpenAIRE

    Ji Zhang; Jie Li

    2016-01-01

    This study aims to develop a semi-implicit constitutive integration algorithm for a class of elastoplastic damage models where calculation of damage energy release rates involves integration of free energy. The constitutive equations with energy integration are split into the elastic predictor, plastic corrector, and damage corrector. The plastic corrector is solved with an improved format of the semi-implicit spectral return mapping, which is characterized by constant flow direction and plas...

  3. Development of a Gravid Uterus Model for the Study of Road Accidents Involving Pregnant Women.

    Science.gov (United States)

    Auriault, F; Thollon, L; Behr, M

    2016-01-01

    Car accident simulations involving pregnant women are well documented in the literature and suggest that intra-uterine pressure could be responsible for the phenomenon of placental abruption, underlining the need for a realistic amniotic fluid model, including fluid-structure interactions (FSI). This study reports the development and validation of an amniotic fluid model using an Arbitrary Lagrangian Eulerian formulation in the LS-DYNA environment. Dedicated to the study of the mechanisms responsible for fetal injuries resulting from road accidents, the fluid model was validated using dynamic loading tests. Drop tests were performed on a deformable water-filled container at acceleration levels that would be experienced in a gravid uterus during a frontal car collision at 25 kph. During the test device braking phase, container deformation induced by inertial effects and FSI was recorded by kinematic analysis. These tests were then simulated in the LS-DYNA environment to validate a fluid model under dynamic loading, based on the container deformations. Finally, the coupling between the amniotic fluid model and an existing finite-element full-body pregnant woman model was validated in terms of pressure. To do so, experimental test results performed on four postmortem human surrogates (PMHS) (in which a physical gravid uterus model was inserted) were used. The experimental intra-uterine pressure from these tests was compared to intra uterine pressure from a numerical simulation performed under the same loading conditions. Both free fall numerical and experimental responses appear strongly correlated. The relationship between the amniotic fluid model and pregnant woman model provide intra-uterine pressure values correlated with the experimental test responses. The use of an Arbitrary Lagrangian Eulerian formulation allows the analysis of FSI between the amniotic fluid and the gravid uterus during a road accident involving pregnant women.

  4. Modelling road accidents: An approach using structural time series

    Science.gov (United States)

    Junus, Noor Wahida Md; Ismail, Mohd Tahir

    2014-09-01

    In this paper, the trend of road accidents in Malaysia for the years 2001 until 2012 was modelled using a structural time series approach. The structural time series model was identified using a stepwise method, and the residuals for each model were tested. The best-fitted model was chosen based on the smallest Akaike Information Criterion (AIC) and prediction error variance. In order to check the quality of the model, a data validation procedure was performed by predicting the monthly number of road accidents for the year 2012. Results indicate that the best specification of the structural time series model to represent road accidents is the local level with a seasonal model.

  5. Functional state modelling approach validation for yeast and bacteria cultivations

    Science.gov (United States)

    Roeva, Olympia; Pencheva, Tania

    2014-01-01

    In this paper, the functional state modelling approach is validated for modelling of the cultivation of two different microorganisms: yeast (Saccharomyces cerevisiae) and bacteria (Escherichia coli). Based on the available experimental data for these fed-batch cultivation processes, three different functional states are distinguished, namely primary product synthesis state, mixed oxidative state and secondary product synthesis state. Parameter identification procedures for different local models are performed using genetic algorithms. The simulation results show high degree of adequacy of the models describing these functional states for both S. cerevisiae and E. coli cultivations. Thus, the local models are validated for the cultivation of both microorganisms. This fact is a strong structure model verification of the functional state modelling theory not only for a set of yeast cultivations, but also for bacteria cultivation. As such, the obtained results demonstrate the efficiency and efficacy of the functional state modelling approach. PMID:26740778

  6. An optimization approach to kinetic model reduction for combustion chemistry

    CERN Document Server

    Lebiedz, Dirk

    2013-01-01

    Model reduction methods are relevant when the computation time of a full convection-diffusion-reaction simulation based on detailed chemical reaction mechanisms is too large. In this article, we review a model reduction approach based on optimization of trajectories and show its applicability to realistic combustion models. As most model reduction methods, it identifies points on a slow invariant manifold based on time scale separation in the dynamics of the reaction system. The numerical approximation of points on the manifold is achieved by solving a semi-infinite optimization problem, where the dynamics enter the problem as constraints. The proof of existence of a solution for an arbitrarily chosen dimension of the reduced model (slow manifold) is extended to the case of realistic combustion models including thermochemistry by considering the properties of proper maps. The model reduction approach is finally applied to three models based on realistic reaction mechanisms: 1. ozone decomposition as a small t...

  7. Functional state modelling approach validation for yeast and bacteria cultivations.

    Science.gov (United States)

    Roeva, Olympia; Pencheva, Tania

    2014-09-03

    In this paper, the functional state modelling approach is validated for modelling of the cultivation of two different microorganisms: yeast (Saccharomyces cerevisiae) and bacteria (Escherichia coli). Based on the available experimental data for these fed-batch cultivation processes, three different functional states are distinguished, namely primary product synthesis state, mixed oxidative state and secondary product synthesis state. Parameter identification procedures for different local models are performed using genetic algorithms. The simulation results show high degree of adequacy of the models describing these functional states for both S. cerevisiae and E. coli cultivations. Thus, the local models are validated for the cultivation of both microorganisms. This fact is a strong structure model verification of the functional state modelling theory not only for a set of yeast cultivations, but also for bacteria cultivation. As such, the obtained results demonstrate the efficiency and efficacy of the functional state modelling approach.

  8. Molecular modelling of S-RNases involved in almond self-incompatibility

    Directory of Open Access Journals (Sweden)

    Angel eFernandez i Marti

    2012-06-01

    Full Text Available Gametophytic self-incompatibility (GSI is a mechanism in flowering plants, to prevent inbreeding and promote outcrossing. GSI is under the control of a specific locus, known as the S-locus, which contains at least two genes, the RNase and the SFB. Active S-RNases in the style are essential for rejection of haploid pollen, when the pollen S-allele matches one of two S-alleles of the diploid pistil. However, the nature of their mutual interactions at genetic and biochemical levels remain unclear. Thus, detailed understanding of the protein structure involved in GSI may help in discovering how the proteins involved in GSI may function and how they fulfil their biological roles. To this end, 3D models of the SC (Sf and two SI (S8 and S23 S-RNases of almond were constructed, using comparative modelling tools. The modelled structures consisted of mixed α and β folds, with six helices and six beta-strands. However, the self-compatible (Sf RNase contained an additional extended loop between the conserved domains RC4 and C5, which may be involved in the manifestation of self-compatibility in almond.

  9. Dynamic Involvement of Real World Objects in the IoT: A Consensus-Based Cooperation Approach.

    Science.gov (United States)

    Pilloni, Virginia; Atzori, Luigi; Mallus, Matteo

    2017-03-01

    A significant role in the Internet of Things (IoT) will be taken by mobile and low-cost unstable devices, which autonomously self-organize and introduce highly dynamic and heterogeneous scenarios for the deployment of distributed applications. This entails the devices to cooperate to dynamically find the suitable combination of their involvement so as to improve the system reliability while following the changes in their status. Focusing on the above scenario, we propose a distributed algorithm for resources allocation that is run by devices that can perform the same task required by the applications, allowing for a flexible and dynamic binding of the requested services with the physical IoT devices. It is based on a consensus approach, which maximizes the lifetime of groups of nodes involved and ensures the fulfillment of the requested Quality of Information (QoI) requirements. Experiments have been conducted with real devices, showing an improvement of device lifetime of more than 20 % , with respect to a uniform distribution of tasks.

  10. Dynamic Involvement of Real World Objects in the IoT: A Consensus-Based Cooperation Approach

    Directory of Open Access Journals (Sweden)

    Virginia Pilloni

    2017-03-01

    Full Text Available A significant role in the Internet of Things (IoT will be taken by mobile and low-cost unstable devices, which autonomously self-organize and introduce highly dynamic and heterogeneous scenarios for the deployment of distributed applications. This entails the devices to cooperate to dynamically find the suitable combination of their involvement so as to improve the system reliability while following the changes in their status. Focusing on the above scenario, we propose a distributed algorithm for resources allocation that is run by devices that can perform the same task required by the applications, allowing for a flexible and dynamic binding of the requested services with the physical IoT devices. It is based on a consensus approach, which maximizes the lifetime of groups of nodes involved and ensures the fulfillment of the requested Quality of Information (QoI requirements. Experiments have been conducted with real devices, showing an improvement of device lifetime of more than 20 % , with respect to a uniform distribution of tasks.

  11. Molecular Modeling Approach to Cardiovascular Disease Targetting

    Directory of Open Access Journals (Sweden)

    Chandra Sekhar Akula,

    2010-05-01

    Full Text Available Cardiovascular disease, including stroke, is the leading cause of illness and death in the India. A number of studies have shown that inflammation of blood vessels is one of the major factors that increase the incidence of heart diseases, including arteriosclerosis (clogging of the arteries, stroke and myocardial infraction or heart attack. Studies have associated obesity and other components of metabolic syndrome, cardiovascular risk factors, with lowgradeinflammation. Furthermore, some findings suggest that drugs commonly prescribed to the lower cholesterol also reduce this inflammation, suggesting an additional beneficial effect of the stains. The recent development of angiotensin 11 (Ang11 receptor antagonists has enabled to improve significantly the tolerability profile of thisgroup of drugs while maintaining a high clinical efficacy. ACE2 is expressed predominantly in the endothelium and in renal tubular epithelium, and it thus may be an import new cardiovascular target. In the present study we modeled the structure of ACE and designed an inhibitor through using ARGUS lab and the validation of the Drug molecule is done basing on QSAR properties and Cache for this protein through CADD.

  12. Virtuous organization: A structural equation modeling approach

    Directory of Open Access Journals (Sweden)

    Majid Zamahani

    2013-02-01

    Full Text Available For years, the idea of virtue was unfavorable among researchers and virtues were traditionally considered as culture-specific, relativistic and they were supposed to be associated with social conservatism, religious or moral dogmatism, and scientific irrelevance. Virtue and virtuousness have been recently considered seriously among organizational researchers. The proposed study of this paper examines the relationships between leadership, organizational culture, human resource, structure and processes, care for community and virtuous organization. Structural equation modeling is employed to investigate the effects of each variable on other components. The data used in this study consists of questionnaire responses from employees in Payam e Noor University in Yazd province. A total of 250 questionnaires were sent out and a total of 211 valid responses were received. Our results have revealed that all the five variables have positive and significant impacts on virtuous organization. Among the five variables, organizational culture has the most direct impact (0.80 and human resource has the most total impact (0.844 on virtuous organization.

  13. A transcriptomic approach to identify regulatory genes involved in fruit set of wild-type and parthenocarpic tomato genotypes.

    Science.gov (United States)

    Ruiu, Fabrizio; Picarella, Maurizio Enea; Imanishi, Shunsuke; Mazzucato, Andrea

    2015-10-01

    The tomato parthenocarpic fruit (pat) mutation associates a strong competence for parthenocarpy with homeotic transformation of anthers and aberrancy of ovules. To dissect this complex floral phenotype, genes involved in the pollination-independent fruit set of the pat mutant were investigated by microarray analysis using wild-type and mutant ovaries. Normalized expression data were subjected to one-way ANOVA and 2499 differentially expressed genes (DEGs) displaying a >1.5 log-fold change in at least one of the pairwise comparisons analyzed were detected. DEGs were categorized into 20 clusters and clusters classified into five groups representing transcripts with similar expression dynamics. The "regulatory function" group (685 DEGs) contained putative negative or positive fruit set regulators, "pollination-dependent" (411 DEGs) included genes activated by pollination, "fruit growth-related" (815 DEGs) genes activated at early fruit growth. The last groups listed genes with different or similar expression pattern at all stages in the two genotypes. qRT-PCR validation of 20 DEGs plus other four selected genes assessed the high reliability of microarray expression data; the average correlation coefficient for the 20 DEGs was 0.90. In all the groups were evidenced relevant transcription factors encoding proteins regulating meristem differentiation and floral organ development, genes involved in metabolism, transport and response of hormones, genes involved in cell division and in primary and secondary metabolism. Among pathways related to secondary metabolites emerged genes related to the synthesis of flavonoids, supporting the recent evidence that these compounds are important at the fruit set phase. Selected genes showing a de-regulated expression pattern in pat were studied in other four parthenocarpic genotypes either genetically anonymous or carrying lesions in known gene sequences. This comparative approach offered novel insights for improving the present

  14. Post-closure biosphere assessment modelling: comparison of complex and more stylised approaches.

    Science.gov (United States)

    Walke, Russell C; Kirchner, Gerald; Xu, Shulan; Dverstorp, Björn

    2015-10-01

    Geological disposal facilities are the preferred option for high-level radioactive waste, due to their potential to provide isolation from the surface environment (biosphere) on very long timescales. Assessments need to strike a balance between stylised models and more complex approaches that draw more extensively on site-specific information. This paper explores the relative merits of complex versus more stylised biosphere models in the context of a site-specific assessment. The more complex biosphere modelling approach was developed by the Swedish Nuclear Fuel and Waste Management Co (SKB) for the Formark candidate site for a spent nuclear fuel repository in Sweden. SKB's approach is built on a landscape development model, whereby radionuclide releases to distinct hydrological basins/sub-catchments (termed 'objects') are represented as they evolve through land rise and climate change. Each of seventeen of these objects is represented with more than 80 site specific parameters, with about 22 that are time-dependent and result in over 5000 input values per object. The more stylised biosphere models developed for this study represent releases to individual ecosystems without environmental change and include the most plausible transport processes. In the context of regulatory review of the landscape modelling approach adopted in the SR-Site assessment in Sweden, the more stylised representation has helped to build understanding in the more complex modelling approaches by providing bounding results, checking the reasonableness of the more complex modelling, highlighting uncertainties introduced through conceptual assumptions and helping to quantify the conservatisms involved. The more stylised biosphere models are also shown capable of reproducing the results of more complex approaches. A major recommendation is that biosphere assessments need to justify the degree of complexity in modelling approaches as well as simplifying and conservative assumptions. In light of

  15. Cardiac involvement in patients with Becker muscular dystrophy: new diagnostic and pathophysiological insights by a CMR approach

    Directory of Open Access Journals (Sweden)

    Thiene Gaetano

    2008-11-01

    Full Text Available Abstract Background Becker-Kiener muscular dystrophy (BMD represents an X-linked genetic disease associated with myocardial involvement potentially resulting in dilated cardiomyopathy (DCM. Early diagnosis of cardiac involvement may permit earlier institution of heart failure treatment and extend life span in these patients. Both echocardiography and nuclear imaging methods are capable of detecting later stages of cardiac involvement characterised by wall motion abnormalities. Cardiovascular magnetic resonance (CMR has the potential to detect cardiac involvement by depicting early scar formation that may appear before onset of wall motion abnormalities. Methods In a prospective two-center-study, 15 male patients with BMD (median age 37 years; range 11 years to 56 years underwent comprehensive neurological and cardiac evaluations including physical examination, echocardiography and CMR. A 16-segment model was applied for evaluation of regional wall motion abnormalities (rWMA. The CMR study included late gadolinium enhancement (LGE imaging with quantification of myocardial damage. Results Abnormal echocardiographic results were found in eight of 15 (53.3% patients with all of them demonstrating reduced left ventricular ejection fraction (LVEF and rWMA. CMR revealed abnormal findings in 12 of 15 (80.0% patients (p = 0.04 with 10 (66.6% having reduced LVEF (p = 0.16 and 9 (64.3% demonstrating rWMA (p = 0.38. Myocardial damage as assessed by LGE-imaging was detected in 11 of 15 (73.3% patients with a median myocardial damage extent of 13.0% (range 0 to 38.0%, an age-related increase and a typical subepicardial distribution pattern in the inferolateral wall. Ten patients (66.7% were in need of medical heart failure therapy based on CMR results. However, only 4 patients (26.7% were already taking medication based on clinical criteria (p = 0.009. Conclusion Cardiac involvement in patients with BMD is underdiagnosed by echocardiographic methods resulting

  16. Data Analysis A Model Comparison Approach, Second Edition

    CERN Document Server

    Judd, Charles M; Ryan, Carey S

    2008-01-01

    This completely rewritten classic text features many new examples, insights and topics including mediational, categorical, and multilevel models. Substantially reorganized, this edition provides a briefer, more streamlined examination of data analysis. Noted for its model-comparison approach and unified framework based on the general linear model, the book provides readers with a greater understanding of a variety of statistical procedures. This consistent framework, including consistent vocabulary and notation, is used throughout to develop fewer but more powerful model building techniques. T

  17. Identification of lipases involved in PBAN stimulated pheromone production in Bombyx mori using the DGE and RNAi approaches.

    Directory of Open Access Journals (Sweden)

    Mengfang Du

    Full Text Available BACKGROUND: Pheromone biosynthesis activating neuropeptide (PBAN is a neurohormone that regulates sex pheromone synthesis in female moths. Bombyx mori is a model organism that has been used to explore the signal transduction pattern of PBAN, which is mediated by a G-protein coupled receptor (GPCR. Although significant progress has been made in elucidating PBAN-regulated lipolysis that releases the precursor of the sex pheromone, little is known about the molecular components involved in this step. To better elucidate the molecular mechanisms of PBAN-stimulated lipolysis of cytoplasmic lipid droplets (LDs, the associated lipase genes involved in PBAN- regulated sex pheromone biosynthesis were identified using digital gene expression (DGE and subsequent RNA interference (RNAi. RESULTS: Three DGE libraries were constructed from pheromone glands (PGs at different developed stages, namely, 72 hours before eclosion (-72 h, new emergence (0 h and 72 h after eclosion (72 h, to investigate the gene expression profiles during PG development. The DGE evaluated over 5.6 million clean tags in each PG sample and revealed numerous genes that were differentially expressed at these stages. Most importantly, seven lipases were found to be richly expressed during the key stage of sex pheromone synthesis and release (new emergence. RNAi-mediated knockdown confirmed for the first time that four of these seven lipases play important roles in sex pheromone synthesis. CONCLUSION: This study has identified four lipases directly involved in PBAN-stimulated sex pheromone biosynthesis, which improve our understanding of the lipases involved in releasing bombykol precursors from triacylglycerols (TAGs within the cytoplasmic LDs.

  18. Comparison of approaches for parameter estimation on stochastic models: Generic least squares versus specialized approaches.

    Science.gov (United States)

    Zimmer, Christoph; Sahle, Sven

    2016-04-01

    Parameter estimation for models with intrinsic stochasticity poses specific challenges that do not exist for deterministic models. Therefore, specialized numerical methods for parameter estimation in stochastic models have been developed. Here, we study whether dedicated algorithms for stochastic models are indeed superior to the naive approach of applying the readily available least squares algorithm designed for deterministic models. We compare the performance of the recently developed multiple shooting for stochastic systems (MSS) method designed for parameter estimation in stochastic models, a stochastic differential equations based Bayesian approach and a chemical master equation based techniques with the least squares approach for parameter estimation in models of ordinary differential equations (ODE). As test data, 1000 realizations of the stochastic models are simulated. For each realization an estimation is performed with each method, resulting in 1000 estimates for each approach. These are compared with respect to their deviation to the true parameter and, for the genetic toggle switch, also their ability to reproduce the symmetry of the switching behavior. Results are shown for different set of parameter values of a genetic toggle switch leading to symmetric and asymmetric switching behavior as well as an immigration-death and a susceptible-infected-recovered model. This comparison shows that it is important to choose a parameter estimation technique that can treat intrinsic stochasticity and that the specific choice of this algorithm shows only minor performance differences.

  19. Parameter identification of multi-body railway vehicle models - Application of the adjoint state approach

    Science.gov (United States)

    Kraft, S.; Puel, G.; Aubry, D.; Funfschilling, C.

    2016-12-01

    For the calibration of multi-body models of railway vehicles, the identification of the model parameters from on-track measurement is required. This involves the solution of an inverse problem by minimising the misfit function which describes the distance between model and measurement using optimisation methods. The application of gradient-based optimisation methods is advantageous but necessitates an efficient approach for the computation of the gradients considering the large number of model parameters and the costly evaluation of the forward model. This work shows that the application of the adjoint state approach to the nonlinear vehicle-track multi-body system is suitable, reducing on the one hand the computational cost and increasing on the other hand the precision of the gradients. Gradients from the adjoint state method are computed for vehicle models and validated taking into account measurement noise.

  20. Modelling and Generating Ajax Applications: A Model-Driven Approach

    NARCIS (Netherlands)

    Gharavi, V.; Mesbah, A.; Van Deursen, A.

    2008-01-01

    Preprint of paper published in: IWWOST 2008 - 7th International Workshop on Web-Oriented Software Technologies, 14-15 July 2008 AJAX is a promising and rapidly evolving approach for building highly interactive web applications. In AJAX, user interface components and the event-based interaction betw

  1. Modelling and Generating Ajax Applications: A Model-Driven Approach

    NARCIS (Netherlands)

    Gharavi, V.; Mesbah, A.; Van Deursen, A.

    2008-01-01

    Preprint of paper published in: IWWOST 2008 - 7th International Workshop on Web-Oriented Software Technologies, 14-15 July 2008 AJAX is a promising and rapidly evolving approach for building highly interactive web applications. In AJAX, user interface components and the event-based interaction

  2. A novel approach to modeling and diagnosing the cardiovascular system

    Energy Technology Data Exchange (ETDEWEB)

    Keller, P.E.; Kangas, L.J.; Hashem, S.; Kouzes, R.T. [Pacific Northwest Lab., Richland, WA (United States); Allen, P.A. [Life Link, Richland, WA (United States)

    1995-07-01

    A novel approach to modeling and diagnosing the cardiovascular system is introduced. A model exhibits a subset of the dynamics of the cardiovascular behavior of an individual by using a recurrent artificial neural network. Potentially, a model will be incorporated into a cardiovascular diagnostic system. This approach is unique in that each cardiovascular model is developed from physiological measurements of an individual. Any differences between the modeled variables and the variables of an individual at a given time are used for diagnosis. This approach also exploits sensor fusion to optimize the utilization of biomedical sensors. The advantage of sensor fusion has been demonstrated in applications including control and diagnostics of mechanical and chemical processes.

  3. Mathematical models for therapeutic approaches to control HIV disease transmission

    CERN Document Server

    Roy, Priti Kumar

    2015-01-01

    The book discusses different therapeutic approaches based on different mathematical models to control the HIV/AIDS disease transmission. It uses clinical data, collected from different cited sources, to formulate the deterministic as well as stochastic mathematical models of HIV/AIDS. It provides complementary approaches, from deterministic and stochastic points of view, to optimal control strategy with perfect drug adherence and also tries to seek viewpoints of the same issue from different angles with various mathematical models to computer simulations. The book presents essential methods and techniques for students who are interested in designing epidemiological models on HIV/AIDS. It also guides research scientists, working in the periphery of mathematical modeling, and helps them to explore a hypothetical method by examining its consequences in the form of a mathematical modelling and making some scientific predictions. The model equations, mathematical analysis and several numerical simulations that are...

  4. Asteroid modeling for testing spacecraft approach and landing.

    Science.gov (United States)

    Martin, Iain; Parkes, Steve; Dunstan, Martin; Rowell, Nick

    2014-01-01

    Spacecraft exploration of asteroids presents autonomous-navigation challenges that can be aided by virtual models to test and develop guidance and hazard-avoidance systems. Researchers have extended and applied graphics techniques to create high-resolution asteroid models to simulate cameras and other spacecraft sensors approaching and descending toward asteroids. A scalable model structure with evenly spaced vertices simplifies terrain modeling, avoids distortion at the poles, and enables triangle-strip definition for efficient rendering. To create the base asteroid models, this approach uses two-phase Poisson faulting and Perlin noise. It creates realistic asteroid surfaces by adding both crater models adapted from lunar terrain simulation and multiresolution boulders. The researchers evaluated the virtual asteroids by comparing them with real asteroid images, examining the slope distributions, and applying a surface-relative feature-tracking algorithm to the models.

  5. A model-driven approach to information security compliance

    Science.gov (United States)

    Correia, Anacleto; Gonçalves, António; Teodoro, M. Filomena

    2017-06-01

    The availability, integrity and confidentiality of information are fundamental to the long-term survival of any organization. Information security is a complex issue that must be holistically approached, combining assets that support corporate systems, in an extended network of business partners, vendors, customers and other stakeholders. This paper addresses the conception and implementation of information security systems, conform the ISO/IEC 27000 set of standards, using the model-driven approach. The process begins with the conception of a domain level model (computation independent model) based on information security vocabulary present in the ISO/IEC 27001 standard. Based on this model, after embedding in the model mandatory rules for attaining ISO/IEC 27001 conformance, a platform independent model is derived. Finally, a platform specific model serves the base for testing the compliance of information security systems with the ISO/IEC 27000 set of standards.

  6. Heuristic approaches to models and modeling in systems biology

    NARCIS (Netherlands)

    MacLeod, Miles

    2016-01-01

    Prediction and control sufficient for reliable medical and other interventions are prominent aims of modeling in systems biology. The short-term attainment of these goals has played a strong role in projecting the importance and value of the field. In this paper I identify the standard models must m

  7. A Machine Learning Approach to Identify Clinical Trials Involving Nanodrugs and Nanodevices from ClinicalTrials.gov

    Science.gov (United States)

    de la Iglesia, Diana; García-Remesal, Miguel; Anguita, Alberto; Muñoz-Mármol, Miguel; Kulikowski, Casimir; Maojo, Víctor

    2014-01-01

    Background Clinical Trials (CTs) are essential for bridging the gap between experimental research on new drugs and their clinical application. Just like CTs for traditional drugs and biologics have helped accelerate the translation of biomedical findings into medical practice, CTs for nanodrugs and nanodevices could advance novel nanomaterials as agents for diagnosis and therapy. Although there is publicly available information about nanomedicine-related CTs, the online archiving of this information is carried out without adhering to criteria that discriminate between studies involving nanomaterials or nanotechnology-based processes (nano), and CTs that do not involve nanotechnology (non-nano). Finding out whether nanodrugs and nanodevices were involved in a study from CT summaries alone is a challenging task. At the time of writing, CTs archived in the well-known online registry ClinicalTrials.gov are not easily told apart as to whether they are nano or non-nano CTs—even when performed by domain experts, due to the lack of both a common definition for nanotechnology and of standards for reporting nanomedical experiments and results. Methods We propose a supervised learning approach for classifying CT summaries from ClinicalTrials.gov according to whether they fall into the nano or the non-nano categories. Our method involves several stages: i) extraction and manual annotation of CTs as nano vs. non-nano, ii) pre-processing and automatic classification, and iii) performance evaluation using several state-of-the-art classifiers under different transformations of the original dataset. Results and Conclusions The performance of the best automated classifier closely matches that of experts (AUC over 0.95), suggesting that it is feasible to automatically detect the presence of nanotechnology products in CT summaries with a high degree of accuracy. This can significantly speed up the process of finding whether reports on ClinicalTrials.gov might be relevant to a

  8. A New Detection Approach Based on the Maximum Entropy Model

    Institute of Scientific and Technical Information of China (English)

    DONG Xiaomei; XIANG Guang; YU Ge; LI Xiaohua

    2006-01-01

    The maximum entropy model was introduced and a new intrusion detection approach based on the maximum entropy model was proposed. The vector space model was adopted for data presentation. The minimal entropy partitioning method was utilized for attribute discretization. Experiments on the KDD CUP 1999 standard data set were designed and the experimental results were shown. The receiver operating characteristic(ROC) curve analysis approach was utilized to analyze the experimental results. The analysis results show that the proposed approach is comparable to those based on support vector machine(SVM) and outperforms those based on C4.5 and Naive Bayes classifiers. According to the overall evaluation result, the proposed approach is a little better than those based on SVM.

  9. LEXICAL APPROACH IN TEACHING TURKISH: A COLLOCATIONAL STUDY MODEL

    Directory of Open Access Journals (Sweden)

    Eser ÖRDEM

    2013-06-01

    Full Text Available Abstract This study intends to propose Lexical Approach (Lewis, 1998, 2002; Harwood, 2002 and a model for teaching Turkish as a foreign language so that this model can be used in classroom settings. This model was created by the researcher as a result of the studies carried out in applied linguistics (Hill, 20009 and memory (Murphy, 2004. Since one of the main problems of foreign language learners is to retrieve what they have learnt, Lewis (1998 and Wray (2008 assume that lexical approach is an alternative explanation to solve this problem.Unlike grammar translation method, this approach supports the idea that language is not composed of general grammar but strings of word and word combinations.In addition, lexical approach posits the idea that each word has tiw gramamtical properties, and therefore each dictionary is a potential grammar book. Foreign language learners can learn to use collocations, a basic principle of Lexical approach. Thus, learners can increase the level of retention.The concept of retrieval clue (Murphy, 2004 is considered the main element in this collocational study model because the main purpose of this model is boost fluency and help learners gain native-like accuracy while producing the target language. Keywords: Foreign language teaching, lexical approach, collocations, retrieval clue

  10. A Model-Driven Approach for Telecommunications Network Services Definition

    Science.gov (United States)

    Chiprianov, Vanea; Kermarrec, Yvon; Alff, Patrick D.

    Present day Telecommunications market imposes a short concept-to-market time for service providers. To reduce it, we propose a computer-aided, model-driven, service-specific tool, with support for collaborative work and for checking properties on models. We started by defining a prototype of the Meta-model (MM) of the service domain. Using this prototype, we defined a simple graphical modeling language specific for service designers. We are currently enlarging the MM of the domain using model transformations from Network Abstractions Layers (NALs). In the future, we will investigate approaches to ensure the support for collaborative work and for checking properties on models.

  11. Competitive growth model involving random deposition and random deposition with surface relaxation

    Energy Technology Data Exchange (ETDEWEB)

    Horowitz, Claudio M.; Monetti, Roberto A.; Albano, Ezequiel V.

    2001-06-01

    A deposition model that considers a mixture of random deposition with surface relaxation and a pure random deposition is proposed and studied. As the system evolves, random deposition with surface relaxation (pure random deposition) take place with probability p and (1{minus}p), respectively. The discrete (microscopic) approach to the model is studied by means of extensive numerical simulations, while continuous equations are used in order to investigate the mesoscopic properties of the model. A dynamic scaling ansatz for the interface width W(L,t,p) as a function of the lattice side L, the time t and p is formulated and tested. Three exponents, which can be linked to the standard growth exponent of random deposition with surface relaxation by means of a scaling relation, are identified. In the continuous limit, the model can be well described by means of a phenomenological stochastic growth equation with a p-dependent effective surface tension.

  12. Deformation analysis of polymers composites: rheological model involving time-based fractional derivative

    DEFF Research Database (Denmark)

    Zhou, H. W.; Yi, H. Y.; Mishnaevsky, Leon

    2016-01-01

    A modeling approach to time-dependent property of Glass Fiber Reinforced Polymers (GFRP) composites is of special interest for quantitative description of long-term behavior. An electronic creep machine is employed to investigate the time-dependent deformation of four specimens of dog......-bond-shaped GFRP composites at various stress level. A negative exponent function based on structural changes is introduced to describe the damage evolution of material properties in the process of creep test. Accordingly, a new creep constitutive equation, referred to fractional derivative Maxwell model...... by the fractional derivative Maxwell model proposed in the paper are in a good agreement with the experimental data. It is shown that the new creep constitutive model proposed in the paper needs few parameters to represent various time-dependent behaviors....

  13. Formalizing An Approach to Curate the Global Change Master Directory (GCMD)'s Controlled Vocabularies (Keywords) Through a Keyword Governance Process and Community Involvement

    Science.gov (United States)

    Stevens, T.

    2016-12-01

    NASA's Global Change Master Directory (GCMD) curates a hierarchical set of controlled vocabularies (keywords) covering Earth sciences and associated information (data centers, projects, platforms, and instruments). The purpose of the keywords is to describe Earth science data and services in a consistent and comprehensive manner, allowing for precise metadata search and subsequent retrieval of data and services. The keywords are accessible in a standardized SKOS/RDF/OWL representation and are used as an authoritative taxonomy, as a source for developing ontologies, and to search and access Earth Science data within online metadata catalogs. The keyword curation approach involves: (1) receiving community suggestions; (2) triaging community suggestions; (3) evaluating keywords against a set of criteria coordinated by the NASA Earth Science Data and Information System (ESDIS) Standards Office; (4) implementing the keywords; and (5) publication/notification of keyword changes. This approach emphasizes community input, which helps ensure a high quality, normalized, and relevant keyword structure that will evolve with users' changing needs. The Keyword Community Forum, which promotes a responsive, open, and transparent process, is an area where users can discuss keyword topics and make suggestions for new keywords. Others could potentially use this formalized approach as a model for keyword curation.

  14. Child human model development: a hybrid validation approach

    NARCIS (Netherlands)

    Forbes, P.A.; Rooij, L. van; Rodarius, C.; Crandall, J.

    2008-01-01

    The current study presents a development and validation approach of a child human body model that will help understand child impact injuries and improve the biofidelity of child anthropometric test devices. Due to the lack of fundamental child biomechanical data needed to fully develop such models a

  15. Modeling Alaska boreal forests with a controlled trend surface approach

    Science.gov (United States)

    Mo Zhou; Jingjing Liang

    2012-01-01

    An approach of Controlled Trend Surface was proposed to simultaneously take into consideration large-scale spatial trends and nonspatial effects. A geospatial model of the Alaska boreal forest was developed from 446 permanent sample plots, which addressed large-scale spatial trends in recruitment, diameter growth, and mortality. The model was tested on two sets of...

  16. Teaching Service Modelling to a Mixed Class: An Integrated Approach

    Science.gov (United States)

    Deng, Jeremiah D.; Purvis, Martin K.

    2015-01-01

    Service modelling has become an increasingly important area in today's telecommunications and information systems practice. We have adapted a Network Design course in order to teach service modelling to a mixed class of both the telecommunication engineering and information systems backgrounds. An integrated approach engaging mathematics teaching…

  17. Gray-box modelling approach for description of storage tunnel

    DEFF Research Database (Denmark)

    Harremoës, Poul; Carstensen, Jacob

    1999-01-01

    The dynamics of a storage tunnel is examined using a model based on on-line measured data and a combination of simple deterministic and black-box stochastic elements. This approach, called gray-box modeling, is a new promising methodology for giving an on-line state description of sewer systems...

  18. Child human model development: a hybrid validation approach

    NARCIS (Netherlands)

    Forbes, P.A.; Rooij, L. van; Rodarius, C.; Crandall, J.

    2008-01-01

    The current study presents a development and validation approach of a child human body model that will help understand child impact injuries and improve the biofidelity of child anthropometric test devices. Due to the lack of fundamental child biomechanical data needed to fully develop such models a

  19. Refining the Committee Approach and Uncertainty Prediction in Hydrological Modelling

    NARCIS (Netherlands)

    Kayastha, N.

    2014-01-01

    Due to the complexity of hydrological systems a single model may be unable to capture the full range of a catchment response and accurately predict the streamflows. The multi modelling approach opens up possibilities for handling such difficulties and allows improve the predictive capability of mode

  20. Refining the committee approach and uncertainty prediction in hydrological modelling

    NARCIS (Netherlands)

    Kayastha, N.

    2014-01-01

    Due to the complexity of hydrological systems a single model may be unable to capture the full range of a catchment response and accurately predict the streamflows. The multi modelling approach opens up possibilities for handling such difficulties and allows improve the predictive capability of mode

  1. Hybrid continuum-atomistic approach to model electrokinetics in nanofluidics

    Energy Technology Data Exchange (ETDEWEB)

    Amani, Ehsan, E-mail: eamani@aut.ac.ir; Movahed, Saeid, E-mail: smovahed@aut.ac.ir

    2016-06-07

    In this study, for the first time, a hybrid continuum-atomistic based model is proposed for electrokinetics, electroosmosis and electrophoresis, through nanochannels. Although continuum based methods are accurate enough to model fluid flow and electric potential in nanofluidics (in dimensions larger than 4 nm), ionic concentration is too low in nanochannels for the continuum assumption to be valid. On the other hand, the non-continuum based approaches are too time-consuming and therefore is limited to simple geometries, in practice. Here, to propose an efficient hybrid continuum-atomistic method of modelling the electrokinetics in nanochannels; the fluid flow and electric potential are computed based on continuum hypothesis coupled with an atomistic Lagrangian approach for the ionic transport. The results of the model are compared to and validated by the results of the molecular dynamics technique for a couple of case studies. Then, the influences of bulk ionic concentration, external electric field, size of nanochannel, and surface electric charge on the electrokinetic flow and ionic mass transfer are investigated, carefully. The hybrid continuum-atomistic method is a promising approach to model more complicated geometries and investigate more details of the electrokinetics in nanofluidics. - Highlights: • A hybrid continuum-atomistic model is proposed for electrokinetics in nanochannels. • The model is validated by molecular dynamics. • This is a promising approach to model more complicated geometries and physics.

  2. Modelling diversity in building occupant behaviour: a novel statistical approach

    DEFF Research Database (Denmark)

    Haldi, Frédéric; Calì, Davide; Andersen, Rune Korsholm

    2016-01-01

    We propose an advanced modelling framework to predict the scope and effects of behavioural diversity regarding building occupant actions on window openings, shading devices and lighting. We develop a statistical approach based on generalised linear mixed models to account for the longitudinal nat...

  3. Asteroid fragmentation approaches for modeling atmospheric energy deposition

    Science.gov (United States)

    Register, Paul J.; Mathias, Donovan L.; Wheeler, Lorien F.

    2017-03-01

    During asteroid entry, energy is deposited in the atmosphere through thermal ablation and momentum-loss due to aerodynamic drag. Analytic models of asteroid entry and breakup physics are used to compute the energy deposition, which can then be compared against measured light curves and used to estimate ground damage due to airburst events. This work assesses and compares energy deposition results from four existing approaches to asteroid breakup modeling, and presents a new model that combines key elements of those approaches. The existing approaches considered include a liquid drop or "pancake" model where the object is treated as a single deforming body, and a set of discrete fragment models where the object breaks progressively into individual fragments. The new model incorporates both independent fragments and aggregate debris clouds to represent a broader range of fragmentation behaviors and reproduce more detailed light curve features. All five models are used to estimate the energy deposition rate versus altitude for the Chelyabinsk meteor impact, and results are compared with an observationally derived energy deposition curve. Comparisons show that four of the five approaches are able to match the overall observed energy deposition profile, but the features of the combined model are needed to better replicate both the primary and secondary peaks of the Chelyabinsk curve.

  4. A Bayesian Approach for Analyzing Longitudinal Structural Equation Models

    Science.gov (United States)

    Song, Xin-Yuan; Lu, Zhao-Hua; Hser, Yih-Ing; Lee, Sik-Yum

    2011-01-01

    This article considers a Bayesian approach for analyzing a longitudinal 2-level nonlinear structural equation model with covariates, and mixed continuous and ordered categorical variables. The first-level model is formulated for measures taken at each time point nested within individuals for investigating their characteristics that are dynamically…

  5. An Empirical-Mathematical Modelling Approach to Upper Secondary Physics

    Science.gov (United States)

    Angell, Carl; Kind, Per Morten; Henriksen, Ellen K.; Guttersrud, Oystein

    2008-01-01

    In this paper we describe a teaching approach focusing on modelling in physics, emphasizing scientific reasoning based on empirical data and using the notion of multiple representations of physical phenomena as a framework. We describe modelling activities from a project (PHYS 21) and relate some experiences from implementation of the modelling…

  6. Refining the Committee Approach and Uncertainty Prediction in Hydrological Modelling

    NARCIS (Netherlands)

    Kayastha, N.

    2014-01-01

    Due to the complexity of hydrological systems a single model may be unable to capture the full range of a catchment response and accurately predict the streamflows. The multi modelling approach opens up possibilities for handling such difficulties and allows improve the predictive capability of mode

  7. Refining the committee approach and uncertainty prediction in hydrological modelling

    NARCIS (Netherlands)

    Kayastha, N.

    2014-01-01

    Due to the complexity of hydrological systems a single model may be unable to capture the full range of a catchment response and accurately predict the streamflows. The multi modelling approach opens up possibilities for handling such difficulties and allows improve the predictive capability of mode

  8. An integral transform approach for a mixed boundary problem involving a flowing partially penetrating well with infinitesimal well skin

    Science.gov (United States)

    Chang, Chien-Chieh; Chen, Chia-Shyun

    2002-06-01

    A flowing partially penetrating well with infinitesimal well skin is a mixed boundary because a Cauchy condition is prescribed along the screen length and a Neumann condition of no flux is stipulated over the remaining unscreened part. An analytical approach based on the integral transform technique is developed to determine the Laplace domain solution for such a mixed boundary problem in a confined aquifer of finite thickness. First, the mixed boundary is changed into a homogeneous Neumann boundary by substituting the Cauchy condition with a Neumann condition in terms of well bore flux that varies along the screen length and is time dependent. Despite the well bore flux being unknown a priori, the modified model containing this homogeneous Neumann boundary can be solved with the Laplace and the finite Fourier cosine transforms. To determine well bore flux, screen length is discretized into a finite number of segments, to which the Cauchy condition is reinstated. This reinstatement also restores the relation between the original model and the solutions obtained. For a given time, the numerical inversion of the Laplace domain solution yields the drawdown distributions, well bore flux, and the well discharge. This analytical approach provides an alternative for dealing with the mixed boundary problems, especially when aquifer thickness is assumed to be finite.

  9. A multilevel approach to modeling of porous bioceramics

    Science.gov (United States)

    Mikushina, Valentina A.; Sidorenko, Yury N.

    2015-10-01

    The paper is devoted to discussion of multiscale models of heterogeneous materials using principles. The specificity of approach considered is the using of geometrical model of composites representative volume, which must be generated with taking the materials reinforcement structure into account. In framework of such model may be considered different physical processes which have influence on the effective mechanical properties of composite, in particular, the process of damage accumulation. It is shown that such approach can be used to prediction the value of composite macroscopic ultimate strength. As an example discussed the particular problem of the study the mechanical properties of biocomposite representing porous ceramics matrix filled with cortical bones tissue.

  10. Gray-box modelling approach for description of storage tunnel

    DEFF Research Database (Denmark)

    Harremoës, Poul; Carstensen, Jacob

    1999-01-01

    of the water in the overflow structures. The capacity of a pump draining the storage tunnel is estimated for two different rain events, revealing that the pump was malfunctioning during the first rain event. The proposed modeling approach can be used in automated online surveillance and control and implemented....... The model in the present paper provides on-line information on overflow volumes, pumping capacities, and remaining storage capacities. A linear overflow relation is found, differing significantly from the traditional deterministic modeling approach. The linearity of the formulas is explained by the inertia...

  11. A study of multidimensional modeling approaches for data warehouse

    Science.gov (United States)

    Yusof, Sharmila Mat; Sidi, Fatimah; Ibrahim, Hamidah; Affendey, Lilly Suriani

    2016-08-01

    Data warehouse system is used to support the process of organizational decision making. Hence, the system must extract and integrate information from heterogeneous data sources in order to uncover relevant knowledge suitable for decision making process. However, the development of data warehouse is a difficult and complex process especially in its conceptual design (multidimensional modeling). Thus, there have been various approaches proposed to overcome the difficulty. This study surveys and compares the approaches of multidimensional modeling and highlights the issues, trend and solution proposed to date. The contribution is on the state of the art of the multidimensional modeling design.

  12. Meta-analysis a structural equation modeling approach

    CERN Document Server

    Cheung, Mike W-L

    2015-01-01

    Presents a novel approach to conducting meta-analysis using structural equation modeling. Structural equation modeling (SEM) and meta-analysis are two powerful statistical methods in the educational, social, behavioral, and medical sciences. They are often treated as two unrelated topics in the literature. This book presents a unified framework on analyzing meta-analytic data within the SEM framework, and illustrates how to conduct meta-analysis using the metaSEM package in the R statistical environment. Meta-Analysis: A Structural Equation Modeling Approach begins by introducing the impo

  13. Modeling and Algorithmic Approaches to Constitutively-Complex, Microstructured Fluids

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Gregory H. [Univ. of California, Davis, CA (United States); Forest, Gregory [Univ. of California, Davis, CA (United States)

    2014-05-01

    We present a new multiscale model for complex fluids based on three scales: microscopic, kinetic, and continuum. We choose the microscopic level as Kramers' bead-rod model for polymers, which we describe as a system of stochastic differential equations with an implicit constraint formulation. The associated Fokker-Planck equation is then derived, and adiabatic elimination removes the fast momentum coordinates. Approached in this way, the kinetic level reduces to a dispersive drift equation. The continuum level is modeled with a finite volume Godunov-projection algorithm. We demonstrate computation of viscoelastic stress divergence using this multiscale approach.

  14. Pore scale modeling of reactive transport involved in geologic CO2 sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Qinjin [Los Alamos National Laboratory; Lichtner, Peter C [Los Alamos National Laboratory; Viswanathan, Hari S [Los Alamos National Laboratory; Abdel-fattah, Amr I [Los Alamos National Laboratory

    2009-01-01

    We apply a multi-component reactive transport lattice Boltzmann model developed in previolls studies to modeling the injection of a C02 saturated brine into various porous media structures at temperature T=25 and 80 C. The porous media are originally consisted of calcite. A chemical system consisting of Na+, Ca2+, Mg2+, H+, CO2(aq), and CI-is considered. The fluid flow, advection and diHusion of aqueous species, homogeneous reactions occurring in the bulk fluid, as weB as the dissolution of calcite and precipitation of dolomite are simulated at the pore scale. The effects of porous media structure on reactive transport are investigated. The results are compared with continuum scale modeling and the agreement and discrepancy are discussed. This work may shed some light on the fundamental physics occurring at the pore scale for reactive transport involved in geologic C02 sequestration.

  15. Modelling binaural processes involved in simultaneous reflection masking: limitations of current models

    DEFF Research Database (Denmark)

    Buchholz, Jörg

    2007-01-01

    Masked thresholds were measured for a single test reflection, masked by the direct sound, as a function of the reflection delay. This was done for diotic as well as for dichotic stimulus presentations and all stimuli were presented via headphones. The input signal was a 200-ms long broadband noise....... The dichotic threshold decreased with increasing reflection delay indicating an increase in binaural detection performance with increasing reflection delay. Comparing the dichotic threshold to the corresponding diotic threshold, for delays below 7-10 ms, the dichotic threshold was found to be higher than...... the diotic threshold while it was lower than the diotic threshold for larger delays. Hence, the binaural system seems to deteriorate auditory detection performance for very early reflections and to enhance auditory detection performance for later reflections. Existing binaural (detection) models...

  16. Metamodelling Approach and Software Tools for Physical Modelling and Simulation

    Directory of Open Access Journals (Sweden)

    Vitaliy Mezhuyev

    2015-02-01

    Full Text Available In computer science, metamodelling approach becomes more and more popular for the purpose of software systems development. In this paper, we discuss applicability of the metamodelling approach for development of software tools for physical modelling and simulation.To define a metamodel for physical modelling the analysis of physical models will be done. The result of such the analyses will show the invariant physical structures, we propose to use as the basic abstractions of the physical metamodel. It is a system of geometrical objects, allowing to build a spatial structure of physical models and to set a distribution of physical properties. For such geometry of distributed physical properties, the different mathematical methods can be applied. To prove the proposed metamodelling approach, we consider the developed prototypes of software tools.

  17. Social learning in Models and Cases - an Interdisciplinary Approach

    Science.gov (United States)

    Buhl, Johannes; De Cian, Enrica; Carrara, Samuel; Monetti, Silvia; Berg, Holger

    2016-04-01

    Our paper follows an interdisciplinary understanding of social learning. We contribute to the literature on social learning in transition research by bridging case-oriented research and modelling-oriented transition research. We start by describing selected theories on social learning in innovation, diffusion and transition research. We present theoretical understandings of social learning in techno-economic and agent-based modelling. Then we elaborate on empirical research on social learning in transition case studies. We identify and synthetize key dimensions of social learning in transition case studies. In the following we bridge between more formal and generalising modelling approaches towards social learning processes and more descriptive, individualising case study approaches by interpreting the case study analysis into a visual guide on functional forms of social learning typically identified in the cases. We then try to exemplarily vary functional forms of social learning in integrated assessment models. We conclude by drawing the lessons learned from the interdisciplinary approach - methodologically and empirically.

  18. Learning the Task Management Space of an Aircraft Approach Model

    Science.gov (United States)

    Krall, Joseph; Menzies, Tim; Davies, Misty

    2014-01-01

    Validating models of airspace operations is a particular challenge. These models are often aimed at finding and exploring safety violations, and aim to be accurate representations of real-world behavior. However, the rules governing the behavior are quite complex: nonlinear physics, operational modes, human behavior, and stochastic environmental concerns all determine the responses of the system. In this paper, we present a study on aircraft runway approaches as modeled in Georgia Tech's Work Models that Compute (WMC) simulation. We use a new learner, Genetic-Active Learning for Search-Based Software Engineering (GALE) to discover the Pareto frontiers defined by cognitive structures. These cognitive structures organize the prioritization and assignment of tasks of each pilot during approaches. We discuss the benefits of our approach, and also discuss future work necessary to enable uncertainty quantification.

  19. Modelling of phase equilibria and related properties of mixtures involving lipids

    DEFF Research Database (Denmark)

    Cunico, Larissa

    Many challenges involving physical and thermodynamic properties in the production of edible oils and biodiesel are observed, such as availability of experimental data and realiable prediction. In the case of lipids, a lack of experimental data for pure components and also for their mixtures in open...... literature was observed, what makes it necessary to development reliable predictive models from limited data. One of the first steps of this project was the creation of a database containing properties of mixtures involved in tasks related to process design, simulation, and optimization as well as design...... of chemicals based products. This database was combined with the existing lipids database of pure component properties. To contribute to the missing data, measurements of isobaric vapour-liquid equilibrium (VLE) data of two binary mixtures at two different pressures were performed using Differential Scanning...

  20. A comparative modeling and molecular docking study on Mycobacterium tuberculosis targets involved in peptidoglycan biosynthesis.

    Science.gov (United States)

    Fakhar, Zeynab; Naiker, Suhashni; Alves, Claudio N; Govender, Thavendran; Maguire, Glenn E M; Lameira, Jeronimo; Lamichhane, Gyanu; Kruger, Hendrik G; Honarparvar, Bahareh

    2016-11-01

    An alarming rise of multidrug-resistant Mycobacterium tuberculosis strains and the continuous high global morbidity of tuberculosis have reinvigorated the need to identify novel targets to combat the disease. The enzymes that catalyze the biosynthesis of peptidoglycan in M. tuberculosis are essential and noteworthy therapeutic targets. In this study, the biochemical function and homology modeling of MurI, MurG, MraY, DapE, DapA, Alr, and Ddl enzymes of the CDC1551 M. tuberculosis strain involved in the biosynthesis of peptidoglycan cell wall are reported. Generation of the 3D structures was achieved with Modeller 9.13. To assess the structural quality of the obtained homology modeled targets, the models were validated using PROCHECK, PDBsum, QMEAN, and ERRAT scores. Molecular dynamics simulations were performed to calculate root mean square deviation (RMSD) and radius of gyration (Rg) of MurI and MurG target proteins and their corresponding templates. For further model validation, RMSD and Rg for selected targets/templates were investigated to compare the close proximity of their dynamic behavior in terms of protein stability and average distances. To identify the potential binding mode required for molecular docking, binding site information of all modeled targets was obtained using two prediction algorithms. A docking study was performed for MurI to determine the potential mode of interaction between the inhibitor and the active site residues. This study presents the first accounts of the 3D structural information for the selected M. tuberculosis targets involved in peptidoglycan biosynthesis.

  1. Various Approaches to Forward and Inverse Wide-Angle Seismic Modelling Tested on Data from DOBRE-4 Experiment

    Directory of Open Access Journals (Sweden)

    Janik Tomasz

    2016-12-01

    Full Text Available The interpretation of seismic refraction and wide angle reflection data usually involves the creation of a velocity model based on an inverse or forward modelling of the travel times of crustal and mantle phases using the ray theory approach. The modelling codes differ in terms of model parameterization, data used for modelling, regularization of the result, etc. It is helpful to know the capabilities, advantages and limitations of the code used compared to others.

  2. Investigation of pulmonary involvement in inflammatory bowel disease in an experimental model of colitis.

    Science.gov (United States)

    Aydin, Bunyamin; Songur, Yıldıran; Songur, Necla; Aksu, Oğuzhan; Senol, Altug; Ciris, I Metin; Sutcu, Recep

    2016-09-01

    Inflammatory bowel disease (IBD) may also involve various extra-intestinal organs. Clinical studies have found asymptomatic/symptomatic pulmonary involvement in 1% to 6% of patients with IBD. The present study histopathologically investigated pulmonary involvement in an experimental model of colitis in order to demonstrate pulmonary tissue involvement in IBD and to expose potential etiological factors. It also explored the relation between inflammation and tissue concentrations of vascular endothelial growth factor (VEGF) and tumor necrosis factor α (TNF-α). The study comprised 24 male Wistar albino rats. The rats were divided into four groups of six rats each. Acute colitis was induced in two separate groups using either the dextran sulphate sodium (DSS) or trinitrobenzene sulfonic acid (TNBS) method, while the other two groups were used as controls for each model of colitis. Wallace scoring was used for macroscopic assessment of colitis, and the lungs were histopathologically examined. Concentrations of VEGF and TNF-α in pulmonary tissue were measured by the enzyme-linked immunosorbent assay method. The number of animals that had alveolar hemorrhage was significantly higher in the TNBS-induced colitis and DSS-induced colitis groups compared to their own control groups (p = 0.015 and p = 0.015, respectively). VEGF and TNF-α concentrations in pulmonary tissues were significantly increased in both the TNBS colitis and DSS colitis groups compared to their own control groups (p = 0.002 and p = 0.004, respectively; and p = 0.002 and p = 0.002, respectively). The present study demonstrated that significant and serious histopathological changes directly associated with colitis occur in the lungs in IBD.

  3. Investigation of pulmonary involvement in inflammatory bowel disease in an experimental model of colitis

    Science.gov (United States)

    Aydin, Bunyamin; Songur, Yıldıran; Songur, Necla; Aksu, Oğuzhan; Senol, Altug; Ciris, I. Metin; Sutcu, Recep

    2016-01-01

    Background/Aims: Inflammatory bowel disease (IBD) may also involve various extra-intestinal organs. Clinical studies have found asymptomatic/symptomatic pulmonary involvement in 1% to 6% of patients with IBD. The present study histopathologically investigated pulmonary involvement in an experimental model of colitis in order to demonstrate pulmonary tissue involvement in IBD and to expose potential etiological factors. It also explored the relation between inflammation and tissue concentrations of vascular endothelial growth factor (VEGF) and tumor necrosis factor α (TNF-α). Methods: The study comprised 24 male Wistar albino rats. The rats were divided into four groups of six rats each. Acute colitis was induced in two separate groups using either the dextran sulphate sodium (DSS) or trinitrobenzene sulfonic acid (TNBS) method, while the other two groups were used as controls for each model of colitis. Wallace scoring was used for macroscopic assessment of colitis, and the lungs were histopathologically examined. Concentrations of VEGF and TNF-α in pulmonary tissue were measured by the enzyme-linked immunosorbent assay method. Results: The number of animals that had alveolar hemorrhage was significantly higher in the TNBS-induced colitis and DSS-induced colitis groups compared to their own control groups (p = 0.015 and p = 0.015, respectively). VEGF and TNF-α concentrations in pulmonary tissues were significantly increased in both the TNBS colitis and DSS colitis groups compared to their own control groups (p = 0.002 and p = 0.004, respectively; and p = 0.002 and p = 0.002, respectively). Conclusions: The present study demonstrated that significant and serious histopathological changes directly associated with colitis occur in the lungs in IBD. PMID:27539446

  4. The Adapted V-Model: A Practical Approach to Agile Testing

    Directory of Open Access Journals (Sweden)

    Yasser Ghanim

    2015-07-01

    Full Text Available Agile methods largely remove the distinction between phases and roles with no predefined order of activities. Some agile approaches such as Test-Driven Development (TDD switch the traditional order of coding and testing and largely remove the boundary between the two implying that testing is becoming more a technical responsibility of the developers! Testers are complaining of loss of identity and scope within agile teams. In parallel some modern non-agile testing approaches such as Risk-based testing also open the boundaries between testing and analysis and suggest more involvement of testers in business and system analysis and sometimes system architecture. This article devises an adapted version of the V-Model for Scrum and suggests a practical approach that aligns the modern testing approaches with agile methodolgies. Scrum will be taken as a representative for Agile. The proposed approach is developed based on the Testing Process Improvement Guide (TPIG developed by the Software Engineering Competence Center.

  5. Current approaches to model extracellular electrical neural microstimulation

    Directory of Open Access Journals (Sweden)

    Sébastien eJoucla

    2014-02-01

    Full Text Available Nowadays, high-density microelectrode arrays provide unprecedented possibilities to precisely activate spatially well-controlled central nervous system (CNS areas. However, this requires optimizing stimulating devices, which in turn requires a good understanding of the effects of microstimulation on cells and tissues. In this context, modeling approaches provide flexible ways to predict the outcome of electrical stimulation in terms of CNS activation. In this paper, we present state-of-the-art modeling methods with sufficient details to allow the reader to rapidly build numerical models of neuronal extracellular microstimulation. These include 1 the computation of the electrical potential field created by the stimulation in the tissue, and 2 the response of a target neuron to this field. Two main approaches are described: First we describe the classical hybrid approach that combines the finite element modeling of the potential field with the calculation of the neuron’s response in a cable equation framework (compartmentalized neuron models. Then, we present a whole finite element approach allows the simultaneous calculation of the extracellular and intracellular potentials, by representing the neuronal membrane with a thin-film approximation. This approach was previously introduced in the frame of neural recording, but has never been implemented to determine the effect of extracellular stimulation on the neural response at a sub-compartment level. Here, we show on an example that the latter modeling scheme can reveal important sub-compartment behavior of the neural membrane that cannot be resolved using the hybrid approach. The goal of this paper is also to describe in detail the practical implementation of these methods to allow the reader to easily build new models using standard software packages. These modeling paradigms, depending on the situation, should help build more efficient high-density neural prostheses for CNS rehabilitation.

  6. Combining engineering and data-driven approaches: Development of a generic fire risk model facilitating calibration

    DEFF Research Database (Denmark)

    De Sanctis, G.; Fischer, K.; Kohler, J.

    2014-01-01

    Fire risk models support decision making for engineering problems under the consistent consideration of the associated uncertainties. Empirical approaches can be used for cost-benefit studies when enough data about the decision problem are available. But often the empirical approaches...... a generic risk model that is calibrated to observed fire loss data. Generic risk models assess the risk of buildings based on specific risk indicators and support risk assessment at a portfolio level. After an introduction to the principles of generic risk assessment, the focus of the present paper...... are not detailed enough. Engineering risk models, on the other hand, may be detailed but typically involve assumptions that may result in a biased risk assessment and make a cost-benefit study problematic. In two related papers it is shown how engineering and data-driven modeling can be combined by developing...

  7. Benchmarking novel approaches for modelling species range dynamics.

    Science.gov (United States)

    Zurell, Damaris; Thuiller, Wilfried; Pagel, Jörn; Cabral, Juliano S; Münkemüller, Tamara; Gravel, Dominique; Dullinger, Stefan; Normand, Signe; Schiffers, Katja H; Moore, Kara A; Zimmermann, Niklaus E

    2016-08-01

    Increasing biodiversity loss due to climate change is one of the most vital challenges of the 21st century. To anticipate and mitigate biodiversity loss, models are needed that reliably project species' range dynamics and extinction risks. Recently, several new approaches to model range dynamics have been developed to supplement correlative species distribution models (SDMs), but applications clearly lag behind model development. Indeed, no comparative analysis has been performed to evaluate their performance. Here, we build on process-based, simulated data for benchmarking five range (dynamic) models of varying complexity including classical SDMs, SDMs coupled with simple dispersal or more complex population dynamic models (SDM hybrids), and a hierarchical Bayesian process-based dynamic range model (DRM). We specifically test the effects of demographic and community processes on model predictive performance. Under current climate, DRMs performed best, although only marginally. Under climate change, predictive performance varied considerably, with no clear winners. Yet, all range dynamic models improved predictions under climate change substantially compared to purely correlative SDMs, and the population dynamic models also predicted reasonable extinction risks for most scenarios. When benchmarking data were simulated with more complex demographic and community processes, simple SDM hybrids including only dispersal often proved most reliable. Finally, we found that structural decisions during model building can have great impact on model accuracy, but prior system knowledge on important processes can reduce these uncertainties considerably. Our results reassure the clear merit in using dynamic approaches for modelling species' response to climate change but also emphasize several needs for further model and data improvement. We propose and discuss perspectives for improving range projections through combination of multiple models and for making these approaches

  8. Application of the Interface Approach in Quantum Ising Models

    OpenAIRE

    Sen, Parongama

    1997-01-01

    We investigate phase transitions in the Ising model and the ANNNI model in transverse field using the interface approach. The exact result of the Ising chain in a transverse field is reproduced. We find that apart from the interfacial energy, there are two other response functions which show simple scaling behaviour. For the ANNNI model in a transverse field, the phase diagram can be fully studied in the region where a ferromagnetic to paramagnetic phase transition occurs. The other region ca...

  9. A Variable Flow Modelling Approach To Military End Strength Planning

    Science.gov (United States)

    2016-12-01

    System Dynamics (SD) model is ideal for strategic analysis as it encompasses all the behaviours of a system and how the behaviours are influenced by...Markov Chain Models Wang describes Markov chain theory as a mathematical tool used to investigate dynamic behaviours of a system in a discrete-time... MODELLING APPROACH TO MILITARY END STRENGTH PLANNING by Benjamin K. Grossi December 2016 Thesis Advisor: Kenneth Doerr Second Reader

  10. New Approaches in Usable Booster System Life Cycle Cost Modeling

    Science.gov (United States)

    2012-01-01

    Lean NPD practices (many) • Lean Production & Operations Practices (many) • Supply Chain Operations Reference ( SCOR ) Model , Best Practices Make Deliver...NEW APPROACHES IN REUSABLE BOOSTER SYSTEM LIFE CYCLE COST MODELING Edgar Zapata National Aeronautics and Space Administration Kennedy Space Center...Kennedy Space Center (KSC) and the Air Force Research Laboratory (AFRL). The work included the creation of a new cost estimating model and an LCC

  11. Cancer stem cells from human breast tumors are involved in spontaneous metastases in orthotopic mouse models

    Science.gov (United States)

    Liu, Huiping; Patel, Manishkumar R.; Prescher, Jennifer A.; Patsialou, Antonia; Qian, Dalong; Lin, Jiahui; Wen, Susanna; Chang, Ya-Fang; Bachmann, Michael H.; Shimono, Yohei; Dalerba, Piero; Adorno, Maddalena; Lobo, Neethan; Bueno, Janet; Dirbas, Frederick M.; Goswami, Sumanta; Somlo, George; Condeelis, John; Contag, Christopher H.; Gambhir, Sanjiv Sam; Clarke, Michael F.

    2010-01-01

    To examine the role of breast cancer stem cells (BCSCs) in metastasis, we generated human-in-mouse breast cancer orthotopic models using patient tumor specimens, labeled with optical reporter fusion genes. These models recapitulate human cancer features not captured with previous models, including spontaneous metastasis in particular, and provide a useful platform for studies of breast tumor initiation and progression. With noninvasive imaging approaches, as few as 10 cells of stably labeled BCSCs could be tracked in vivo, enabling studies of early tumor growth and spontaneous metastasis. These advances in BCSC imaging revealed that CD44+ cells from both primary tumors and lung metastases are highly enriched for tumor-initiating cells. Our metastatic cancer models, combined with noninvasive imaging techniques, constitute an integrated approach that could be applied to dissect the molecular mechanisms underlying the dissemination of metastatic CSCs (MCSCs) and to explore therapeutic strategies targeting MCSCs in general or to evaluate individual patient tumor cells and predict response to therapy. PMID:20921380

  12. A machine learning approach for the identification of key markers involved in brain development from single-cell transcriptomic data.

    Science.gov (United States)

    Hu, Yongli; Hase, Takeshi; Li, Hui Peng; Prabhakar, Shyam; Kitano, Hiroaki; Ng, See Kiong; Ghosh, Samik; Wee, Lawrence Jin Kiat

    2016-12-22

    The ability to sequence the transcriptomes of single cells using single-cell RNA-seq sequencing technologies presents a shift in the scientific paradigm where scientists, now, are able to concurrently investigate the complex biology of a heterogeneous population of cells, one at a time. However, till date, there has not been a suitable computational methodology for the analysis of such intricate deluge of data, in particular techniques which will aid the identification of the unique transcriptomic profiles difference between the different cellular subtypes. In this paper, we describe the novel methodology for the analysis of single-cell RNA-seq data, obtained from neocortical cells and neural progenitor cells, using machine learning algorithms (Support Vector machine (SVM) and Random Forest (RF)). Thirty-eight key transcripts were identified, using the SVM-based recursive feature elimination (SVM-RFE) method of feature selection, to best differentiate developing neocortical cells from neural progenitor cells in the SVM and RF classifiers built. Also, these genes possessed a higher discriminative power (enhanced prediction accuracy) as compared commonly used statistical techniques or geneset-based approaches. Further downstream network reconstruction analysis was carried out to unravel hidden general regulatory networks where novel interactions could be further validated in web-lab experimentation and be useful candidates to be targeted for the treatment of neuronal developmental diseases. This novel approach reported for is able to identify transcripts, with reported neuronal involvement, which optimally differentiate neocortical cells and neural progenitor cells. It is believed to be extensible and applicable to other single-cell RNA-seq expression profiles like that of the study of the cancer progression and treatment within a highly heterogeneous tumour.

  13. An Efficient Multi-Scale Modelling Approach for ssDNA Motion in Fluid Flow

    Institute of Scientific and Technical Information of China (English)

    M.Benke; E.Shapiro; D.Drikakis

    2008-01-01

    The paper presents a multi-scale modelling approach for simulating macromolecules in fluid flows. Macromolecule transport at low number densities is frequently encountered in biomedical devices, such as separators, detection and analysis systems. Accurate modelling of this process is challenging due to the wide range of physical scales involved. The continuum approach is not valid for low solute concentrations, but the large timescales of the fluid flow make purely molecular simulations prohibitively expensive. A promising multi-scale modelling strategy is provided by the meta-modelling approach considered in this paper. Meta-models are based on the coupled solution of fluid flow equations and equations of motion for a simplified mechanical model of macromolecules. The approach enables simulation of individual macromolecules at macroscopic time scales. Meta-models often rely on particle-corrector algorithms, which impose length constraints on the mechanical model. Lack of robustness of the particle-corrector algorithm employed can lead to slow convergence and numerical instability. A new FAst Linear COrrector (FALCO) algorithm is introduced in this paper, which significantly improves computational efficiency in comparison with the widely used SHAKE algorithm. Validation of the new particle corrector against a simple analytic solution is performed and improved convergence is demonstrated for ssDNA motion in a lid-driven micro-cavity.

  14. A microarray approach to identify genes involved in seed-pericarp cross-talk and development in peach

    Directory of Open Access Journals (Sweden)

    Zaffalon Valerio

    2011-06-01

    Full Text Available Abstract Background Field observations and a few physiological studies have demonstrated that peach embryogenesis and fruit development are tightly coupled. In fact, attempts to stimulate parthenocarpic fruit development by means of external tools have failed. Moreover, physiological disturbances during early embryo development lead to seed abortion and fruitlet abscission. Later in embryo development, the interactions between seed and fruit development become less strict. As there is limited genetic and molecular information about seed-pericarp cross-talk and development in peach, a massive gene approach based on the use of the μPEACH 1.0 array platform and quantitative real time RT-PCR (qRT-PCR was used to study this process. Results A comparative analysis of the transcription profiles conducted in seed and mesocarp (cv Fantasia throughout different developmental stages (S1, S2, S3 and S4 evidenced that 455 genes are differentially expressed in seed and fruit. Among differentially expressed genes some were validated as markers in two subsequent years and in three different genotypes. Seed markers were a LTP1 (lipid transfer protein, a PR (pathogenesis-related protein, a prunin and LEA (Late Embryogenesis Abundant protein, for S1, S2, S3 and S4, respectively. Mesocarp markers were a RD22-like protein, a serin-carboxypeptidase, a senescence related protein and an Aux/IAA, for S1, S2, S3 and S4, respectively. The microarray data, analyzed by using the HORMONOMETER platform, allowed the identification of hormone-responsive genes, some of them putatively involved in seed-pericarp crosstalk. Results indicated that auxin, cytokinins, and gibberellins are good candidates, acting either directly (auxin or indirectly as signals during early development, when the cross-talk is more active and vital for fruit set, whereas abscisic acid and ethylene may be involved later on. Conclusions In this research, genes were identified marking different phases of

  15. Cognitive control in majority search: A computational modeling approach

    Directory of Open Access Journals (Sweden)

    Hongbin eWang

    2011-02-01

    Full Text Available Despite the importance of cognitive control in many cognitive tasks involving uncertainty, the computational mechanisms of cognitive control in response to uncertainty remain unclear. In this study, we develop biologically realistic neural network models to investigate the instantiation of cognitive control in a majority function task, where one determines the category to which the majority of items in a group belong. Two models are constructed, both of which include the same set of modules representing task-relevant brain functions and share the same model structure. However, with a critical change of a model parameter setting, the two models implement two different underlying algorithms: one for grouping search (where a subgroup of items are sampled and re-sampled until a congruent sample is found and the other for self-terminating search (where the items are scanned and counted one-by-one until the majority is decided. The two algorithms hold distinct implications for the involvement of cognitive control. The modeling results show that while both models are able to perform the task, the grouping search model fit the human data better than the self-terminating search model. An examination of the dynamics underlying model performance reveals how cognitive control might be instantiated in the brain via the V4-ACC-LPFC-IPS loop for computing the majority function.

  16. Cognitive control in majority search: a computational modeling approach.

    Science.gov (United States)

    Wang, Hongbin; Liu, Xun; Fan, Jin

    2011-01-01

    Despite the importance of cognitive control in many cognitive tasks involving uncertainty, the computational mechanisms of cognitive control in response to uncertainty remain unclear. In this study, we develop biologically realistic neural network models to investigate the instantiation of cognitive control in a majority function task, where one determines the category to which the majority of items in a group belong. Two models are constructed, both of which include the same set of modules representing task-relevant brain functions and share the same model structure. However, with a critical change of a model parameter setting, the two models implement two different underlying algorithms: one for grouping search (where a subgroup of items are sampled and re-sampled until a congruent sample is found) and the other for self-terminating search (where the items are scanned and counted one-by-one until the majority is decided). The two algorithms hold distinct implications for the involvement of cognitive control. The modeling results show that while both models are able to perform the task, the grouping search model fit the human data better than the self-terminating search model. An examination of the dynamics underlying model performance reveals how cognitive control might be instantiated in the brain for computing the majority function.

  17. University Physics Students' Use of Models in Explanations of Phenomena Involving Interaction between Metals and Electromagnetic Radiation.

    Science.gov (United States)

    Redfors, Andreas; Ryder, Jim

    2001-01-01

    Examines third year university physics students' use of models when explaining familiar phenomena involving interaction between metals and electromagnetic radiation. Concludes that few students use a single model consistently. (Contains 27 references.) (DDR)

  18. Shared Decision-Making Models Acknowledging an Interprofessional Approach: A Theory Analysis to Inform Nursing Practice.

    Science.gov (United States)

    Lewis, Krystina B; Stacey, Dawn; Squires, Janet E; Carroll, Sandra

    2016-01-01

    Patient engagement in collaboration with health professionals is essential to deliver quality health care. A shared decision-making (SDM) approach requires that patients are involved in decisions regarding their health. SDM is expanding from the patient-physician dyad to incorporate an interprofessional perspective. Conceptual models can be used to better understand theoretical underpinnings for application in clinical practice. The aim of this article was to conduct a theory analysis of conceptual models using an interprofessional approach to SDM and discuss each model's relevance to nursing practice. Walker and Avant's theory analysis approach was used. Three conceptual models were eligible. For all models, the decision-making process was considered iterative. The development process was described for 1 model. All models were logical, parsimonious, and generalizable. One was supported by empirical testing. No model described how partnerships are enacted to achieve interprofessional SDM. Also, there was limited articulation as to how nurses' roles and contributions differ from other team members. This theory analysis highlights the need for a model that explains how partnerships among interprofessional team members are enacted to better understand the operationalization of interprofessional SDM. Implications for nursing practice at all system levels are offered and supported by the 3 models.

  19. THE FAIRSHARES MODEL: AN ETHICAL APPROACH TO SOCIAL ENTERPRISE DEVELOPMENT?

    OpenAIRE

    Ridley-Duff, R.

    2015-01-01

    This paper is based on the keynote address to the 14th International Association of Public and Non-Profit Marketing (IAPNM) conference. It explore the question "What impact do ethical values in the FairShares Model have on social entrepreneurial behaviour?" In the first part, three broad approaches to social enterprise are set out: co-operative and mutual enterprises (CMEs), social and responsible businesses (SRBs) and charitable trading activities (CTAs). The ethics that guide each approach ...

  20. Deformation analysis of polymers composites: rheological model involving time-based fractional derivative

    Science.gov (United States)

    Zhou, H. W.; Yi, H. Y.; Mishnaevsky, L.; Wang, R.; Duan, Z. Q.; Chen, Q.

    2016-08-01

    A modeling approach to time-dependent property of Glass Fiber Reinforced Polymers (GFRP) composites is of special interest for quantitative description of long-term behavior. An electronic creep machine is employed to investigate the time-dependent deformation of four specimens of dog-bond-shaped GFRP composites at various stress level. A negative exponent function based on structural changes is introduced to describe the damage evolution of material properties in the process of creep test. Accordingly, a new creep constitutive equation, referred to fractional derivative Maxwell model, is suggested to characterize the time-dependent behavior of GFRP composites by replacing Newtonian dashpot with the Abel dashpot in the classical Maxwell model. The analytic solution for the fractional derivative Maxwell model is given and the relative parameters are determined. The results estimated by the fractional derivative Maxwell model proposed in the paper are in a good agreement with the experimental data. It is shown that the new creep constitutive model proposed in the paper needs few parameters to represent various time-dependent behaviors.

  1. A computational language approach to modeling prose recall in schizophrenia.

    Science.gov (United States)

    Rosenstein, Mark; Diaz-Asper, Catherine; Foltz, Peter W; Elvevåg, Brita

    2014-06-01

    Many cortical disorders are associated with memory problems. In schizophrenia, verbal memory deficits are a hallmark feature. However, the exact nature of this deficit remains elusive. Modeling aspects of language features used in memory recall have the potential to provide means for measuring these verbal processes. We employ computational language approaches to assess time-varying semantic and sequential properties of prose recall at various retrieval intervals (immediate, 30 min and 24 h later) in patients with schizophrenia, unaffected siblings and healthy unrelated control participants. First, we model the recall data to quantify the degradation of performance with increasing retrieval interval and the effect of diagnosis (i.e., group membership) on performance. Next we model the human scoring of recall performance using an n-gram language sequence technique, and then with a semantic feature based on Latent Semantic Analysis. These models show that automated analyses of the recalls can produce scores that accurately mimic human scoring. The final analysis addresses the validity of this approach by ascertaining the ability to predict group membership from models built on the two classes of language features. Taken individually, the semantic feature is most predictive, while a model combining the features improves accuracy of group membership prediction slightly above the semantic feature alone as well as over the human rating approach. We discuss the implications for cognitive neuroscience of such a computational approach in exploring the mechanisms of prose recall.

  2. Intelligent Transportation and Evacuation Planning A Modeling-Based Approach

    CERN Document Server

    Naser, Arab

    2012-01-01

    Intelligent Transportation and Evacuation Planning: A Modeling-Based Approach provides a new paradigm for evacuation planning strategies and techniques. Recently, evacuation planning and modeling have increasingly attracted interest among researchers as well as government officials. This interest stems from the recent catastrophic hurricanes and weather-related events that occurred in the southeastern United States (Hurricane Katrina and Rita). The evacuation methods that were in place before and during the hurricanes did not work well and resulted in thousands of deaths. This book offers insights into the methods and techniques that allow for implementing mathematical-based, simulation-based, and integrated optimization and simulation-based engineering approaches for evacuation planning. This book also: Comprehensively discusses the application of mathematical models for evacuation and intelligent transportation modeling Covers advanced methodologies in evacuation modeling and planning Discusses principles a...

  3. A model selection approach to analysis of variance and covariance.

    Science.gov (United States)

    Alber, Susan A; Weiss, Robert E

    2009-06-15

    An alternative to analysis of variance is a model selection approach where every partition of the treatment means into clusters with equal value is treated as a separate model. The null hypothesis that all treatments are equal corresponds to the partition with all means in a single cluster. The alternative hypothesis correspond to the set of all other partitions of treatment means. A model selection approach can also be used for a treatment by covariate interaction, where the null hypothesis and each alternative correspond to a partition of treatments into clusters with equal covariate effects. We extend the partition-as-model approach to simultaneous inference for both treatment main effect and treatment interaction with a continuous covariate with separate partitions for the intercepts and treatment-specific slopes. The model space is the Cartesian product of the intercept partition and the slope partition, and we develop five joint priors for this model space. In four of these priors the intercept and slope partition are dependent. We advise on setting priors over models, and we use the model to analyze an orthodontic data set that compares the frictional resistance created by orthodontic fixtures. Copyright (c) 2009 John Wiley & Sons, Ltd.

  4. Towards a whole-cell modeling approach for synthetic biology

    Science.gov (United States)

    Purcell, Oliver; Jain, Bonny; Karr, Jonathan R.; Covert, Markus W.; Lu, Timothy K.

    2013-06-01

    Despite rapid advances over the last decade, synthetic biology lacks the predictive tools needed to enable rational design. Unlike established engineering disciplines, the engineering of synthetic gene circuits still relies heavily on experimental trial-and-error, a time-consuming and inefficient process that slows down the biological design cycle. This reliance on experimental tuning is because current modeling approaches are unable to make reliable predictions about the in vivo behavior of synthetic circuits. A major reason for this lack of predictability is that current models view circuits in isolation, ignoring the vast number of complex cellular processes that impinge on the dynamics of the synthetic circuit and vice versa. To address this problem, we present a modeling approach for the design of synthetic circuits in the context of cellular networks. Using the recently published whole-cell model of Mycoplasma genitalium, we examined the effect of adding genes into the host genome. We also investigated how codon usage correlates with gene expression and find agreement with existing experimental results. Finally, we successfully implemented a synthetic Goodwin oscillator in the whole-cell model. We provide an updated software framework for the whole-cell model that lays the foundation for the integration of whole-cell models with synthetic gene circuit models. This software framework is made freely available to the community to enable future extensions. We envision that this approach will be critical to transforming the field of synthetic biology into a rational and predictive engineering discipline.

  5. A transformation approach for collaboration based requirement models

    CERN Document Server

    Harbouche, Ahmed; Mokhtari, Aicha

    2012-01-01

    Distributed software engineering is widely recognized as a complex task. Among the inherent complexities is the process of obtaining a system design from its global requirement specification. This paper deals with such transformation process and suggests an approach to derive the behavior of a given system components, in the form of distributed Finite State Machines, from the global system requirements, in the form of an augmented UML Activity Diagrams notation. The process of the suggested approach is summarized in three steps: the definition of the appropriate source Meta-Model (requirements Meta-Model), the definition of the target Design Meta-Model and the definition of the rules to govern the transformation during the derivation process. The derivation process transforms the global system requirements described as UML diagram activities (extended with collaborations) to system roles behaviors represented as UML finite state machines. The approach is implemented using Atlas Transformation Language (ATL).

  6. A TRANSFORMATION APPROACH FOR COLLABORATION BASED REQUIREMENT MODELS

    Directory of Open Access Journals (Sweden)

    Ahmed Harbouche

    2012-02-01

    Full Text Available Distributed software engineering is widely recognized as a complex task. Among the inherent complexitiesis the process of obtaining a system design from its global requirement specification. This paper deals withsuch transformation process and suggests an approach to derive the behavior of a given systemcomponents, in the form of distributed Finite State Machines, from the global system requirements, in theform of an augmented UML Activity Diagrams notation. The process of the suggested approach issummarized in three steps: the definition of the appropriate source Meta-Model (requirements Meta-Model, the definition of the target Design Meta-Model and the definition of the rules to govern thetransformation during the derivation process. The derivation process transforms the global systemrequirements described as UML diagram activities (extended with collaborations to system rolesbehaviors represented as UML finite state machines. The approach is implemented using AtlasTransformation Language (ATL.

  7. Collaborative product and process model: Multiple Viewpoints approach

    CERN Document Server

    Geryville, Hichem; Ouzrout, Yacine; Sapidis, Nikolaos

    2007-01-01

    The design and development of complex products invariably involves many actors who have different points of view on the problem they are addressing, the product being developed, and the process by which it is being developed. The actors' viewpoints approach was designed to provide an organisational framework in which these different perspectives or points of views, and their relationships, could be explicitly gathered and formatted (by actor activity's focus). The approach acknowledges the inevitability of multiple interpretation of product information as different views, promotes gathering of actors' interests, and encourages retrieved adequate information while providing support for integration through PLM and/or SCM collaboration. In this paper, we present our multiple viewpoints approach, and we illustrate it by an industrial example on cyclone vessel product.

  8. An algebraic approach to modeling in software engineering

    Energy Technology Data Exchange (ETDEWEB)

    Loegel, G.J. [Superconducting Super Collider Lab., Dallas, TX (United States)]|[Michigan Univ., Ann Arbor, MI (United States); Ravishankar, C.V. [Michigan Univ., Ann Arbor, MI (United States)

    1993-09-01

    Our work couples the formalism of universal algebras with the engineering techniques of mathematical modeling to develop a new approach to the software engineering process. Our purpose in using this combination is twofold. First, abstract data types and their specification using universal algebras can be considered a common point between the practical requirements of software engineering and the formal specification of software systems. Second, mathematical modeling principles provide us with a means for effectively analyzing real-world systems. We first use modeling techniques to analyze a system and then represent the analysis using universal algebras. The rest of the software engineering process exploits properties of universal algebras that preserve the structure of our original model. This paper describes our software engineering process and our experience using it on both research and commercial systems. We need a new approach because current software engineering practices often deliver software that is difficult to develop and maintain. Formal software engineering approaches use universal algebras to describe ``computer science`` objects like abstract data types, but in practice software errors are often caused because ``real-world`` objects are improperly modeled. There is a large semantic gap between the customer`s objects and abstract data types. In contrast, mathematical modeling uses engineering techniques to construct valid models for real-world systems, but these models are often implemented in an ad hoc manner. A combination of the best features of both approaches would enable software engineering to formally specify and develop software systems that better model real systems. Software engineering, like mathematical modeling, should concern itself first and foremost with understanding a real system and its behavior under given circumstances, and then with expressing this knowledge in an executable form.

  9. A model linking sources of stress to approach and avoidance coping styles of Turkish basketball referees.

    Science.gov (United States)

    Anshel, Mark Howard; Sutarso, Toto; Ekmekci, Ridvan; Saraswati, Intan W

    2014-01-01

    Purpose of this study was to externally validate and test a conceptual transient model involving six paths that linked sources of acute stress to avoidance and approach coping styles among Turkish basketball referees. The sample consisted of 125 Turkish basketball referees ranging in age from 18 to 36 years (mean = 25.58. σ = 3.69). The path analysis tested the relationships simultaneously from stressors, in consecutive order, distractions, subpar performance and verbal abuse, to coping styles, first both avoidance-cognitive and approach-cognitive, and then approach-behaviour. Results indicated that the model achieved a good fit and that all paths tested simultaneously were significant. The distractions stressor was positively related to subpar performance, which, in turn, was positively related to verbal abuse. Verbal abuse was negatively associated with an avoidance-cognitive coping style and positively related to the approach-cognitive coping style. The results also supported a crossover effect of both avoidance-cognitive and approach-cognitive on approach-behaviour. One implication of this study is that coping should be studied in naturally occurring stages, a process-oriented approach. Another implication is that approach and avoidance coping styles, each sub-divided into cognitive and behavioural categories, provide a meaningful framework which provides sports officials a coherent structure for learning and improving ways to cope with acute stress experienced during the contest.

  10. A comparison of various modelling approaches applied to Cholera ...

    African Journals Online (AJOL)

    in the ability to assess results objectively via significance testing and other ... The focus in this paper is on the model fitting component, and not on the .... A popular way to gain insight into the dominant frequencies of a signal is to ... may involve noise generated by autoregressive processes, alternative algorithms such as.

  11. Overview of Computer Simulation Modeling Approaches and Methods

    Science.gov (United States)

    Robert E. Manning; Robert M. Itami; David N. Cole; Randy Gimblett

    2005-01-01

    The field of simulation modeling has grown greatly with recent advances in computer hardware and software. Much of this work has involved large scientific and industrial applications for which substantial financial resources are available. However, advances in object-oriented programming and simulation methodology, concurrent with dramatic increases in computer...

  12. DISTRIBUTED APPROACH to WEB PAGE CATEGORIZATION USING MAPREDUCE PROGRAMMING MODEL

    Directory of Open Access Journals (Sweden)

    P.Malarvizhi

    2011-12-01

    Full Text Available The web is a large repository of information and to facilitate the search and retrieval of pages from it,categorization of web documents is essential. An effective means to handle the complexity of information retrieval from the internet is through automatic classification of web pages. Although lots of automatic classification algorithms and systems have been presented, most of the existing approaches are computationally challenging. In order to overcome this challenge, we have proposed a parallel algorithm, known as MapReduce programming model to automatically categorize the web pages. This approach incorporates three concepts. They are web crawler, MapReduce programming model and the proposed web page categorization approach. Initially, we have utilized web crawler to mine the World Wide Web and the crawled web pages are then directly given as input to the MapReduce programming model. Here the MapReduce programming model adapted to our proposed web page categorization approach finds the appropriate category of the web page according to its content. The experimental results show that our proposed parallel web page categorization approach achieves satisfactory results in finding the right category for any given web page.

  13. Injury Severity of Motorcycle Riders Involved in Traffic Crashes in Hunan, China: A Mixed Ordered Logit Approach

    Directory of Open Access Journals (Sweden)

    Fangrong Chang

    2016-07-01

    Full Text Available Issues related to motorcycle safety in China have not received enough research attention. As such, the causal relationship between injury outcomes of motorcycle crashes and potential risk factors remains unknown. This study intended to investigate the injury risk of motorcyclists involved in road traffic crashes in China. To account for the ordinal nature of response outcomes and unobserved heterogeneity, a mixed ordered logit model was employed. Given that the crash occurrence process is different between intersections and non-intersections, separate models were developed for these locations to independently estimate the impacts of various contributing factors on motorcycle riders’ injury severity. The analysis was based on the police-reported crash dataset obtained from the Traffic Administration Bureau of Hunan Provincial Public Security Ministry. Factors associated with a substantially higher probability of fatalities and severe injuries included motorcycle riders older than 60 years, the absence of helmets, motorcycle riders identified to be equal duty, and when a motorcycle collided with a heavy vehicle during the night time without lighting. Crashes occurred along county roads with curve and slope alignment or at regions with higher GDP were associated with an elevated risk of fatality of motorcycle riders, while unsignalized intersections were related to less severe injuries. Findings of this study are beneficial in forming several targeted countermeasures for motorcycle safety in China, including designing roads with appropriate road delineation and street lighting, strict enforcement for speeding and red light violations, promoting helmet usage, and improving the conspicuity of motorcyclists.

  14. Injury Severity of Motorcycle Riders Involved in Traffic Crashes in Hunan, China: A Mixed Ordered Logit Approach.

    Science.gov (United States)

    Chang, Fangrong; Li, Maosheng; Xu, Pengpeng; Zhou, Hanchu; Haque, Md Mazharul; Huang, Helai

    2016-07-14

    Issues related to motorcycle safety in China have not received enough research attention. As such, the causal relationship between injury outcomes of motorcycle crashes and potential risk factors remains unknown. This study intended to investigate the injury risk of motorcyclists involved in road traffic crashes in China. To account for the ordinal nature of response outcomes and unobserved heterogeneity, a mixed ordered logit model was employed. Given that the crash occurrence process is different between intersections and non-intersections, separate models were developed for these locations to independently estimate the impacts of various contributing factors on motorcycle riders' injury severity. The analysis was based on the police-reported crash dataset obtained from the Traffic Administration Bureau of Hunan Provincial Public Security Ministry. Factors associated with a substantially higher probability of fatalities and severe injuries included motorcycle riders older than 60 years, the absence of helmets, motorcycle riders identified to be equal duty, and when a motorcycle collided with a heavy vehicle during the night time without lighting. Crashes occurred along county roads with curve and slope alignment or at regions with higher GDP were associated with an elevated risk of fatality of motorcycle riders, while unsignalized intersections were related to less severe injuries. Findings of this study are beneficial in forming several targeted countermeasures for motorcycle safety in China, including designing roads with appropriate road delineation and street lighting, strict enforcement for speeding and red light violations, promoting helmet usage, and improving the conspicuity of motorcyclists.

  15. Teaching Service Modelling to a Mixed Class: An Integrated Approach

    Directory of Open Access Journals (Sweden)

    Jeremiah D. DENG

    2015-04-01

    Full Text Available Service modelling has become an increasingly important area in today's telecommunications and information systems practice. We have adapted a Network Design course in order to teach service modelling to a mixed class of both the telecommunication engineering and information systems backgrounds. An integrated approach engaging mathematics teaching with strategies such as problem-solving, visualization, and the use of examples and simulations, has been developed. From assessment on student learning outcomes, it is indicated that the proposed course delivery approach succeeded in bringing out comparable and satisfactory performance from students of different educational backgrounds.

  16. A Spatial Clustering Approach for Stochastic Fracture Network Modelling

    Science.gov (United States)

    Seifollahi, S.; Dowd, P. A.; Xu, C.; Fadakar, A. Y.

    2014-07-01

    Fracture network modelling plays an important role in many application areas in which the behaviour of a rock mass is of interest. These areas include mining, civil, petroleum, water and environmental engineering and geothermal systems modelling. The aim is to model the fractured rock to assess fluid flow or the stability of rock blocks. One important step in fracture network modelling is to estimate the number of fractures and the properties of individual fractures such as their size and orientation. Due to the lack of data and the complexity of the problem, there are significant uncertainties associated with fracture network modelling in practice. Our primary interest is the modelling of fracture networks in geothermal systems and, in this paper, we propose a general stochastic approach to fracture network modelling for this application. We focus on using the seismic point cloud detected during the fracture stimulation of a hot dry rock reservoir to create an enhanced geothermal system; these seismic points are the conditioning data in the modelling process. The seismic points can be used to estimate the geographical extent of the reservoir, the amount of fracturing and the detailed geometries of fractures within the reservoir. The objective is to determine a fracture model from the conditioning data by minimizing the sum of the distances of the points from the fitted fracture model. Fractures are represented as line segments connecting two points in two-dimensional applications or as ellipses in three-dimensional (3D) cases. The novelty of our model is twofold: (1) it comprises a comprehensive fracture modification scheme based on simulated annealing and (2) it introduces new spatial approaches, a goodness-of-fit measure for the fitted fracture model, a measure for fracture similarity and a clustering technique for proposing a locally optimal solution for fracture parameters. We use a simulated dataset to demonstrate the application of the proposed approach

  17. Computing phase relations involving ordered solid solutions ab initio: Three thermodynamic approaches to the Fe-Si binary

    Science.gov (United States)

    Asimow, P. D.; Caracas, R.; Wolf, A. S.; Harvey, J. P.

    2016-12-01

    To find inner core compositions (X) consistent with geophysical data, we need phase relations of multicomponent metallic systems at high pressure (P) and temperature (T); the stable phase at a given (P,T,X) determines the physical properties. Given the difficulty of experiments under inner core conditions, reliable computations of such phase relations are needed. Despite advances in computational methods and computing power, challenges include proper treatment of solid solutions with their continuous variation in composition and ordering phenomena. We consider here how to predict phase diagrams from thermodynamic models of partly ordered solid solution phases calibrated with density functional theory to obtain static enthalpy (H) and volume (V), density functional perturbation theory and quasiharmonic approximation for vibrational heat capacity, and three approaches to solution theory to parameterize mixing properties. This approach is applied to B2 and HCP structures in the system Fe-FeSi for comparison to experimental data such as Fischer et al. (2013). We computed H and V of 7 compositions across the Fe-FeSi binary for both B2 and HCP structures, every 20 or 40 GPa from 0 to 400 GPa. We used supercells with up to 24 atoms to explore multiple configurations of the atoms. The H differences among clustered, random, and ordered arrangments of the atoms are neither so small as to imply random mixing nor so large that one configuration will dominate. We computed phonon density of states of at least three compositions for each structure in order to define vibrational heat capacity across each binary using ideal mixing and to test this approximation. We then used three different approaches to solid solution theory to fit the mixing properties: (1) Asymmetric regular solution theory, with (P,T)-dependent Margules parameters to describe the excess H but assuming ideal one-site entropy (S) of mixing; (2) the quasichemical model, accounting for optimized Fe-Si pair

  18. Joint Modeling of Multiple Crimes: A Bayesian Spatial Approach

    Directory of Open Access Journals (Sweden)

    Hongqiang Liu

    2017-01-01

    Full Text Available A multivariate Bayesian spatial modeling approach was used to jointly model the counts of two types of crime, i.e., burglary and non-motor vehicle theft, and explore the geographic pattern of crime risks and relevant risk factors. In contrast to the univariate model, which assumes independence across outcomes, the multivariate approach takes into account potential correlations between crimes. Six independent variables are included in the model as potential risk factors. In order to fully present this method, both the multivariate model and its univariate counterpart are examined. We fitted the two models to the data and assessed them using the deviance information criterion. A comparison of the results from the two models indicates that the multivariate model was superior to the univariate model. Our results show that population density and bar density are clearly associated with both burglary and non-motor vehicle theft risks and indicate a close relationship between these two types of crime. The posterior means and 2.5% percentile of type-specific crime risks estimated by the multivariate model were mapped to uncover the geographic patterns. The implications, limitations and future work of the study are discussed in the concluding section.

  19. A modified dynamic evolving neural-fuzzy approach to modeling customer satisfaction for affective design.

    Science.gov (United States)

    Kwong, C K; Fung, K Y; Jiang, Huimin; Chan, K Y; Siu, Kin Wai Michael

    2013-01-01

    Affective design is an important aspect of product development to achieve a competitive edge in the marketplace. A neural-fuzzy network approach has been attempted recently to model customer satisfaction for affective design and it has been proved to be an effective one to deal with the fuzziness and non-linearity of the modeling as well as generate explicit customer satisfaction models. However, such an approach to modeling customer satisfaction has two limitations. First, it is not suitable for the modeling problems which involve a large number of inputs. Second, it cannot adapt to new data sets, given that its structure is fixed once it has been developed. In this paper, a modified dynamic evolving neural-fuzzy approach is proposed to address the above mentioned limitations. A case study on the affective design of mobile phones was conducted to illustrate the effectiveness of the proposed methodology. Validation tests were conducted and the test results indicated that: (1) the conventional Adaptive Neuro-Fuzzy Inference System (ANFIS) failed to run due to a large number of inputs; (2) the proposed dynamic neural-fuzzy model outperforms the subtractive clustering-based ANFIS model and fuzzy c-means clustering-based ANFIS model in terms of their modeling accuracy and computational effort.

  20. A survey on control schemes for distributed solar collector fields. Part I: Modeling and basic control approaches

    Energy Technology Data Exchange (ETDEWEB)

    Camacho, E.F.; Rubio, F.R. [Universidad de Sevilla, Escuela Superior de Ingenieros, Departamento de Ingenieria de Sistemas y Automatica, Camino de Los Descubrimientos s/n, E-41092, Sevilla (Spain); Berenguel, M. [Universidad de Almeria, Departamento de Lenguajes y Computacion, Area de Ingenieria de Sistemas y Automatica, Carretera Sacramento s/n, E-04120 La Canada, Almeria (Spain); Valenzuela, L. [Plataforma Solar de Almeria - CIEMAT, Carretera Senes s/n, P.O. Box 22, E-04200 Tabernas, Almeria (Spain)

    2007-10-15

    This article presents a survey of the different automatic control techniques that have been applied to control the outlet temperature of solar plants with distributed collectors during the last 25 years. Different aspects of the control problem involved in this kind of plants are treated, from modeling and simulation approaches to the different basic control schemes developed and successfully applied in real solar plants. A classification of the modeling and control approaches is used to explain the main features of each strategy. (author)

  1. An equivalent circuit approach to the modelling of the dynamics of dye sensitized solar cells

    DEFF Research Database (Denmark)

    Bay, L.; West, K.

    2005-01-01

    be calculated and used to optimize the photo electrode with respect to thickness and density. The result is mathematically equivalent to the usual approach for IMVS and IMPS modelling based on diffusion equations describing the transport of electrons in the semiconductor and on charge accumulation in traps......A model that can be used to interpret the response of a dye-sensitized photo electrode to intensity-modulated light (intensity modulated voltage spectroscopy, IMVS and intensity modulated photo-current spectroscopy, IMPS) is presented. The model is based on an equivalent circuit approach involving...... a transmission line with both an electrical and an ionic branch. An analytical expression including a term from the passive electrochemical impedance of the network, and a term accounting for the photo generation in the electrode is found. From this model IMVS and IMPS responses as well as W curves can...

  2. Risk evaluation of uranium mining: A geochemical inverse modelling approach

    Science.gov (United States)

    Rillard, J.; Zuddas, P.; Scislewski, A.

    2011-12-01

    It is well known that uranium extraction operations can increase risks linked to radiation exposure. The toxicity of uranium and associated heavy metals is the main environmental concern regarding exploitation and processing of U-ore. In areas where U mining is planned, a careful assessment of toxic and radioactive element concentrations is recommended before the start of mining activities. A background evaluation of harmful elements is important in order to prevent and/or quantify future water contamination resulting from possible migration of toxic metals coming from ore and waste water interaction. Controlled leaching experiments were carried out to investigate processes of ore and waste (leached ore) degradation, using samples from the uranium exploitation site located in Caetité-Bahia, Brazil. In experiments in which the reaction of waste with water was tested, we found that the water had low pH and high levels of sulphates and aluminium. On the other hand, in experiments in which ore was tested, the water had a chemical composition comparable to natural water found in the region of Caetité. On the basis of our experiments, we suggest that waste resulting from sulphuric acid treatment can induce acidification and salinization of surface and ground water. For this reason proper storage of waste is imperative. As a tool to evaluate the risks, a geochemical inverse modelling approach was developed to estimate the water-mineral interaction involving the presence of toxic elements. We used a method earlier described by Scislewski and Zuddas 2010 (Geochim. Cosmochim. Acta 74, 6996-7007) in which the reactive surface area of mineral dissolution can be estimated. We found that the reactive surface area of rock parent minerals is not constant during time but varies according to several orders of magnitude in only two months of interaction. We propose that parent mineral heterogeneity and particularly, neogenic phase formation may explain the observed variation of the

  3. A Multiple Model Approach to Modeling Based on Fuzzy Support Vector Machines

    Institute of Scientific and Technical Information of China (English)

    冯瑞; 张艳珠; 宋春林; 邵惠鹤

    2003-01-01

    A new multiple models(MM) approach was proposed to model complex industrial process by using Fuzzy Support Vector Machines (F SVMs). By applying the proposed approach to a pH neutralization titration experi-ment, F_SVMs MM not only provides satisfactory approximation and generalization property, but also achieves superior performance to USOCPN multiple modeling method and single modeling method based on standard SVMs.

  4. A compressive sensing-based approach for Preisach hysteresis model identification

    Science.gov (United States)

    Zhang, Jun; Torres, David; Sepúlveda, Nelson; Tan, Xiaobo

    2016-07-01

    The Preisach hysteresis model has been adopted extensively in magnetic and smart material-based systems. Fidelity of the model hinges on accurate identification of the Preisach density function. Existing work on the identification of the density function usually involves applying an input that provides sufficient excitation and measuring a large set of output data. In this paper, we propose a novel compressive sensing-based approach for Preisach model identification that requires fewer measurements. The proposed approach adopts the discrete cosine transform of the output data to obtain a sparse vector, where the order of all the output data is assumed to be known. The model parameters can be efficiently reconstructed using the proposed scheme. For comparison purposes, a constrained least-squares scheme using the same number of measurements is also considered. The root-mean-square error is adopted to examine the model identification performance. The proposed identification approach is shown to have better performance than the least-squares scheme through both simulation and experiments involving a vanadium dioxide ({{VO}}2)-integrated microactuator. This work was supported by the National Science Foundation (CMMI 1301243).

  5. Software sensors based on the grey-box modelling approach

    DEFF Research Database (Denmark)

    Carstensen, J.; Harremoës, P.; Strube, Rune

    1996-01-01

    In recent years the grey-box modelling approach has been applied to wastewater transportation and treatment Grey-box models are characterized by the combination of deterministic and stochastic terms to form a model where all the parameters are statistically identifiable from the on......-line measurements. With respect to the development of software sensors, the grey-box models possess two important features. Firstly, the on-line measurements can be filtered according to the grey-box model in order to remove noise deriving from the measuring equipment and controlling devices. Secondly, the grey-box...... models may contain terms which can be estimated on-line by use of the models and measurements. In this paper, it is demonstrated that many storage basins in sewer systems can be used as an on-line flow measurement provided that the basin is monitored on-line with a level transmitter and that a grey-box...

  6. Environmental Radiation Effects on Mammals A Dynamical Modeling Approach

    CERN Document Server

    Smirnova, Olga A

    2010-01-01

    This text is devoted to the theoretical studies of radiation effects on mammals. It uses the framework of developed deterministic mathematical models to investigate the effects of both acute and chronic irradiation in a wide range of doses and dose rates on vital body systems including hematopoiesis, small intestine and humoral immunity, as well as on the development of autoimmune diseases. Thus, these models can contribute to the development of the system and quantitative approaches in radiation biology and ecology. This text is also of practical use. Its modeling studies of the dynamics of granulocytopoiesis and thrombocytopoiesis in humans testify to the efficiency of employment of the developed models in the investigation and prediction of radiation effects on these hematopoietic lines. These models, as well as the properly identified models of other vital body systems, could provide a better understanding of the radiation risks to health. The modeling predictions will enable the implementation of more ef...

  7. Inventory Model for Deteriorating Items Involving Fuzzy with Shortages and Exponential Demand

    Directory of Open Access Journals (Sweden)

    Sharmila Vijai Stanly

    2015-11-01

    Full Text Available This paper considers the fuzzy inventory model for deteriorating items for power demand under fully backlogged conditions. We define various factors which are affecting the inventory cost by using the shortage costs. An intention of this paper is to study the inventory modelling through fuzzy environment. Inventory parameters, such as holding cost, shortage cost, purchasing cost and deterioration cost are assumed to be the trapezoidal fuzzy numbers. In addition, an efficient algorithm is developed to determine the optimal policy, and the computational effort and time are small for the proposed algorithm. It is simple to implement, and our approach is illustrated through some numerical examples to demonstrate the application and the performance of the proposed methodology.

  8. The standard data model approach to patient record transfer.

    Science.gov (United States)

    Canfield, K; Silva, M; Petrucci, K

    1994-01-01

    This paper develops an approach to electronic data exchange of patient records from Ambulatory Encounter Systems (AESs). This approach assumes that the AES is based upon a standard data model. The data modeling standard used here is IDEFIX for Entity/Relationship (E/R) modeling. Each site that uses a relational database implementation of this standard data model (or a subset of it) can exchange very detailed patient data with other such sites using industry standard tools and without excessive programming efforts. This design is detailed below for a demonstration project between the research-oriented geriatric clinic at the Baltimore Veterans Affairs Medical Center (BVAMC) and the Laboratory for Healthcare Informatics (LHI) at the University of Maryland.

  9. Model selection and inference a practical information-theoretic approach

    CERN Document Server

    Burnham, Kenneth P

    1998-01-01

    This book is unique in that it covers the philosophy of model-based data analysis and an omnibus strategy for the analysis of empirical data The book introduces information theoretic approaches and focuses critical attention on a priori modeling and the selection of a good approximating model that best represents the inference supported by the data Kullback-Leibler information represents a fundamental quantity in science and is Hirotugu Akaike's basis for model selection The maximized log-likelihood function can be bias-corrected to provide an estimate of expected, relative Kullback-Leibler information This leads to Akaike's Information Criterion (AIC) and various extensions and these are relatively simple and easy to use in practice, but little taught in statistics classes and far less understood in the applied sciences than should be the case The information theoretic approaches provide a unified and rigorous theory, an extension of likelihood theory, an important application of information theory, and are ...

  10. Real-space renormalization group approach to the Anderson model

    Science.gov (United States)

    Campbell, Eamonn

    Many of the most interesting electronic behaviours currently being studied are associated with strong correlations. In addition, many of these materials are disordered either intrinsically or due to doping. Solving interacting systems exactly is extremely computationally expensive, and approximate techniques developed for strongly correlated systems are not easily adapted to include disorder. As a non-interacting disordered model, it makes sense to consider the Anderson model as a first step in developing an approximate method of solution to the interacting and disordered Anderson-Hubbard model. Our renormalization group (RG) approach is modeled on that proposed by Johri and Bhatt [23]. We found an error in their work which we have corrected in our procedure. After testing the execution of the RG, we benchmarked the density of states and inverse participation ratio results against exact diagonalization. Our approach is significantly faster than exact diagonalization and is most accurate in the limit of strong disorder.

  11. Model Convolution: A Computational Approach to Digital Image Interpretation

    Science.gov (United States)

    Gardner, Melissa K.; Sprague, Brian L.; Pearson, Chad G.; Cosgrove, Benjamin D.; Bicek, Andrew D.; Bloom, Kerry; Salmon, E. D.

    2010-01-01

    Digital fluorescence microscopy is commonly used to track individual proteins and their dynamics in living cells. However, extracting molecule-specific information from fluorescence images is often limited by the noise and blur intrinsic to the cell and the imaging system. Here we discuss a method called “model-convolution,” which uses experimentally measured noise and blur to simulate the process of imaging fluorescent proteins whose spatial distribution cannot be resolved. We then compare model-convolution to the more standard approach of experimental deconvolution. In some circumstances, standard experimental deconvolution approaches fail to yield the correct underlying fluorophore distribution. In these situations, model-convolution removes the uncertainty associated with deconvolution and therefore allows direct statistical comparison of experimental and theoretical data. Thus, if there are structural constraints on molecular organization, the model-convolution method better utilizes information gathered via fluorescence microscopy, and naturally integrates experiment and theory. PMID:20461132

  12. A new approach of high speed cutting modelling: SPH method

    OpenAIRE

    LIMIDO, Jérôme; Espinosa, Christine; Salaün, Michel; Lacome, Jean-Luc

    2006-01-01

    The purpose of this study is to introduce a new approach of high speed cutting numerical modelling. A lagrangian Smoothed Particle Hydrodynamics (SPH) based model is carried out using the Ls-Dyna software. SPH is a meshless method, thus large material distortions that occur in the cutting problem are easily managed and SPH contact control permits a “natural” workpiece/chip separation. Estimated chip morphology and cutting forces are compared to machining dedicated code results and experimenta...

  13. Schwinger boson approach to the fully screened Kondo model.

    Science.gov (United States)

    Rech, J; Coleman, P; Zarand, G; Parcollet, O

    2006-01-13

    We apply the Schwinger boson scheme to the fully screened Kondo model and generalize the method to include antiferromagnetic interactions between ions. Our approach captures the Kondo crossover from local moment behavior to a Fermi liquid with a nontrivial Wilson ratio. When applied to the two-impurity model, the mean-field theory describes the "Varma-Jones" quantum phase transition between a valence bond state and a heavy Fermi liquid.

  14. Kallen Lehman approach to 3D Ising model

    Science.gov (United States)

    Canfora, F.

    2007-03-01

    A “Kallen-Lehman” approach to Ising model, inspired by quantum field theory à la Regge, is proposed. The analogy with the Kallen-Lehman representation leads to a formula for the free-energy of the 3D model with few free parameters which could be matched with the numerical data. The possible application of this scheme to the spin glass case is shortly discussed.

  15. Modelling approaches in sedimentology: Introduction to the thematic issue

    Science.gov (United States)

    Joseph, Philippe; Teles, Vanessa; Weill, Pierre

    2016-09-01

    As an introduction to this thematic issue on "Modelling approaches in sedimentology", this paper gives an overview of the workshop held in Paris on 7 November 2013 during the 14th Congress of the French Association of Sedimentologists. A synthesis of the workshop in terms of concepts, spatial and temporal scales, constraining data, and scientific challenges is first presented, then a discussion on the possibility of coupling different models, the industrial needs, and the new potential domains of research is exposed.

  16. Modeling Electronic Circular Dichroism within the Polarizable Embedding Approach

    DEFF Research Database (Denmark)

    Nørby, Morten S; Olsen, Jógvan Magnus Haugaard; Steinmann, Casper

    2017-01-01

    We present a systematic investigation of the key components needed to model single chromophore electronic circular dichroism (ECD) within the polarizable embedding (PE) approach. By relying on accurate forms of the embedding potential, where especially the inclusion of local field effects...... sampling. We show that a significant number of snapshots are needed to avoid artifacts in the calculated electronic circular dichroism parameters due to insufficient configurational sampling, thus highlighting the efficiency of the PE model....

  17. Computational Models of Spreadsheet Development: Basis for Educational Approaches

    CERN Document Server

    Hodnigg, Karin; Mittermeir, Roland T

    2008-01-01

    Among the multiple causes of high error rates in spreadsheets, lack of proper training and of deep understanding of the computational model upon which spreadsheet computations rest might not be the least issue. The paper addresses this problem by presenting a didactical model focussing on cell interaction, thus exceeding the atomicity of cell computations. The approach is motivated by an investigation how different spreadsheet systems handle certain computational issues implied from moving cells, copy-paste operations, or recursion.

  18. Modeling Water Shortage Management Using an Object-Oriented Approach

    Science.gov (United States)

    Wang, J.; Senarath, S.; Brion, L.; Niedzialek, J.; Novoa, R.; Obeysekera, J.

    2007-12-01

    As a result of the increasing global population and the resulting urbanization, water shortage issues have received increased attention throughout the world . Water supply has not been able to keep up with increased demand for water, especially during times of drought. The use of an object-oriented (OO) approach coupled with efficient mathematical models is an effective tool in addressing discrepancies between water supply and demand. Object-oriented modeling has been proven powerful and efficient in simulating natural behavior. This research presents a way to model water shortage management using the OO approach. Three groups of conceptual components using the OO approach are designed for the management model. The first group encompasses evaluation of natural behaviors and possible related management options. This evaluation includes assessing any discrepancy that might exist between water demand and supply. The second group is for decision making which includes the determination of water use cutback amount and duration using established criteria. The third group is for implementation of the management options which are restrictions of water usage at a local or regional scale. The loop is closed through a feedback mechanism where continuity in the time domain is established. Like many other regions, drought management is very important in south Florida. The Regional Simulation Model (RSM) is a finite volume, fully integrated hydrologic model used by the South Florida Water Management District to evaluate regional response to various planning alternatives including drought management. A trigger module was developed for RSM that encapsulates the OO approach to water shortage management. Rigorous testing of the module was performed using historical south Florida conditions. Keywords: Object-oriented, modeling, water shortage management, trigger module, Regional Simulation Model

  19. Urban Modelling with Typological Approach. Case Study: Merida, Yucatan, Mexico

    Science.gov (United States)

    Rodriguez, A.

    2017-08-01

    In three-dimensional models of urban historical reconstruction, missed contextual architecture faces difficulties because it does not have much written references in contrast to the most important monuments. This is the case of Merida, Yucatan, Mexico during the Colonial Era (1542-1810), which has lost much of its heritage. An alternative to offer a hypothetical view of these elements is a typological - parametric definition that allows a 3D modeling approach to the most common features of this heritage evidence.

  20. An MCDA and GIS coupling conceptual model to be used in a circular decision process by stakeholders involved in large wind farm projects

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez, M. [Quebec Univ., Rimouski, PQ (Canada). Laboratoire de Recherche en Energie Eolienne; Quebec Univ., Montreal, PQ (Canada). GEIGER; Waaub, J.P. [Quebec Univ., Montreal, PQ (Canada). GEIGER; Ilinca, A. [Quebec Univ., Rimouski, PQ (Canada). Laboratoire de Recherche en Energie Eolienne

    2010-07-01

    This poster presentation described an MCDA and geographic information system (GIS) coupling conceptual model designed for use in stakeholder decision-making processes for large wind farm projects. The model was comprised of 4 modules and 4 stakeholder categories that considered the environment and communities involved in the project. The integrated modelling approach was designed to ensure a transparent decision-making process. The modules included: (1) an MCDA module, (2) a local expertise and scientific knowledge module, (3) a stakeholder involvement module, and (4) a participatory GIS module. The model can be used to structure issues during consultation procedures, as well as to conduct preference analyses and to identify indicators. Examples of stakeholder weighting were included. tabs., figs.

  1. Excellent approach to modeling urban expansion by fuzzy cellular automata: agent base model

    Science.gov (United States)

    Khajavigodellou, Yousef; Alesheikh, Ali A.; Mohammed, Abdulrazak A. S.; Chapi, Kamran

    2014-09-01

    Recently, the interaction between humans and their environment is the one of important challenges in the world. Landuse/ cover change (LUCC) is a complex process that includes actors and factors at different social and spatial levels. The complexity and dynamics of urban systems make the applicable practice of urban modeling very difficult. With the increased computational power and the greater availability of spatial data, micro-simulation such as the agent based and cellular automata simulation methods, has been developed by geographers, planners, and scholars, and it has shown great potential for representing and simulating the complexity of the dynamic processes involved in urban growth and land use change. This paper presents Fuzzy Cellular Automata in Geospatial Information System and remote Sensing to simulated and predicted urban expansion pattern. These FCA-based dynamic spatial urban models provide an improved ability to forecast and assess future urban growth and to create planning scenarios, allowing us to explore the potential impacts of simulations that correspond to urban planning and management policies. A fuzzy inference guided cellular automata approach. Semantic or linguistic knowledge on Land use change is expressed as fuzzy rules, based on which fuzzy inference is applied to determine the urban development potential for each pixel. The model integrates an ABM (agent-based model) and FCA (Fuzzy Cellular Automata) to investigate a complex decision-making process and future urban dynamic processes. Based on this model rapid development and green land protection under the influences of the behaviors and decision modes of regional authority agents, real estate developer agents, resident agents and non- resident agents and their interactions have been applied to predict the future development patterns of the Erbil metropolitan region.

  2. Physiologically Based Pharmacokinetic Modeling to Predict Drug-Drug Interactions with Efavirenz Involving Simultaneous Inducing and Inhibitory Effects on Cytochromes.

    Science.gov (United States)

    Marzolini, Catia; Rajoli, Rajith; Battegay, Manuel; Elzi, Luigia; Back, David; Siccardi, Marco

    2017-04-01

    Antiretroviral drugs are among the therapeutic agents with the highest potential for drug-drug interactions (DDIs). In the absence of clinical data, DDIs are mainly predicted based on preclinical data and knowledge of the disposition of individual drugs. Predictions can be challenging, especially when antiretroviral drugs induce and inhibit multiple cytochrome P450 (CYP) isoenzymes simultaneously. This study predicted the magnitude of the DDI between efavirenz, an inducer of CYP3A4 and inhibitor of CYP2C8, and dual CYP3A4/CYP2C8 substrates (repaglinide, montelukast, pioglitazone, paclitaxel) using a physiologically based pharmacokinetic (PBPK) modeling approach integrating concurrent effects on CYPs. In vitro data describing the physicochemical properties, absorption, distribution, metabolism, and elimination of efavirenz and CYP3A4/CYP2C8 substrates as well as the CYP-inducing and -inhibitory potential of efavirenz were obtained from published literature. The data were integrated in a PBPK model developed using mathematical descriptions of molecular, physiological, and anatomical processes defining pharmacokinetics. Plasma drug-concentration profiles were simulated at steady state in virtual individuals for each drug given alone or in combination with efavirenz. The simulated pharmacokinetic parameters of drugs given alone were compared against existing clinical data. The effect of efavirenz on CYP was compared with published DDI data. The predictions indicate that the overall effect of efavirenz on dual CYP3A4/CYP2C8 substrates is induction of metabolism. The magnitude of induction tends to be less pronounced for dual CYP3A4/CYP2C8 substrates with predominant CYP2C8 metabolism. PBPK modeling constitutes a useful mechanistic approach for the quantitative prediction of DDI involving simultaneous inducing or inhibitory effects on multiple CYPs as often encountered with antiretroviral drugs.

  3. a Study of Urban Stormwater Modeling Approach in Singapore Catchment

    Science.gov (United States)

    Liew, S. C.; Liong, S. Y.; Vu, M. T.

    2011-07-01

    Urbanization has the direct effect of increasing the amount of surface runoff to be discharged through man-made drainage systems. Thus, Singapore's rapid urbanization has drawn great attention on flooding issues. In view of this, proper stormwater modeling approach is necessary for the assessment planning, design, and control of the storm and combines sewerage system. Impacts of urbanization on surface runoff and catchment flooding in Singapore are studied in this paper. In this study, the application of SOBEK-urban 1D is introduced on model catchments and a hypothetical catchment model is created for simulation purpose. Stormwater modeling approach using SOBEK-urban offers a comprehensive modeling tool for simple or extensive urban drainage systems consisting of sewers and open channels despite its size and complexity of the network. The findings from the present study show that stormwater modeling is able to identify flood area and the impact of the anticipated sea level on urban drainage network. Consequently, the performance of the urban drainage system can be improved and early prevention approaches can be carried out.

  4. The Generalised Ecosystem Modelling Approach in Radiological Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Klos, Richard

    2008-03-15

    An independent modelling capability is required by SSI in order to evaluate dose assessments carried out in Sweden by, amongst others, SKB. The main focus is the evaluation of the long-term radiological safety of radioactive waste repositories for both spent fuel and low-level radioactive waste. To meet the requirement for an independent modelling tool for use in biosphere dose assessments, SSI through its modelling team CLIMB commissioned the development of a new model in 2004, a project to produce an integrated model of radionuclides in the landscape. The generalised ecosystem modelling approach (GEMA) is the result. GEMA is a modular system of compartments representing the surface environment. It can be configured, through water and solid material fluxes, to represent local details in the range of ecosystem types found in the past, present and future Swedish landscapes. The approach is generic but fine tuning can be carried out using local details of the surface drainage system. The modular nature of the modelling approach means that GEMA modules can be linked to represent large scale surface drainage features over an extended domain in the landscape. System change can also be managed in GEMA, allowing a flexible and comprehensive model of the evolving landscape to be constructed. Environmental concentrations of radionuclides can be calculated and the GEMA dose pathway model provides a means of evaluating the radiological impact of radionuclide release to the surface environment. This document sets out the philosophy and details of GEMA and illustrates the functioning of the model with a range of examples featuring the recent CLIMB review of SKB's SR-Can assessment

  5. An Application of Bayesian Approach in Modeling Risk of Death in an Intensive Care Unit.

    Directory of Open Access Journals (Sweden)

    Rowena Syn Yin Wong

    Full Text Available There are not many studies that attempt to model intensive care unit (ICU risk of death in developing countries, especially in South East Asia. The aim of this study was to propose and describe application of a Bayesian approach in modeling in-ICU deaths in a Malaysian ICU.This was a prospective study in a mixed medical-surgery ICU in a multidisciplinary tertiary referral hospital in Malaysia. Data collection included variables that were defined in Acute Physiology and Chronic Health Evaluation IV (APACHE IV model. Bayesian Markov Chain Monte Carlo (MCMC simulation approach was applied in the development of four multivariate logistic regression predictive models for the ICU, where the main outcome measure was in-ICU mortality risk. The performance of the models were assessed through overall model fit, discrimination and calibration measures. Results from the Bayesian models were also compared against results obtained using frequentist maximum likelihood method.The study involved 1,286 consecutive ICU admissions between January 1, 2009 and June 30, 2010, of which 1,111 met the inclusion criteria. Patients who were admitted to the ICU were generally younger, predominantly male, with low co-morbidity load and mostly under mechanical ventilation. The overall in-ICU mortality rate was 18.5% and the overall mean Acute Physiology Score (APS was 68.5. All four models exhibited good discrimination, with area under receiver operating characteristic curve (AUC values approximately 0.8. Calibration was acceptable (Hosmer-Lemeshow p-values > 0.05 for all models, except for model M3. Model M1 was identified as the model with the best overall performance in this study.Four prediction models were proposed, where the best model was chosen based on its overall performance in this study. This study has also demonstrated the promising potential of the Bayesian MCMC approach as an alternative in the analysis and modeling of in-ICU mortality outcomes.

  6. An Application of Bayesian Approach in Modeling Risk of Death in an Intensive Care Unit

    Science.gov (United States)

    Wong, Rowena Syn Yin; Ismail, Noor Azina

    2016-01-01

    Background and Objectives There are not many studies that attempt to model intensive care unit (ICU) risk of death in developing countries, especially in South East Asia. The aim of this study was to propose and describe application of a Bayesian approach in modeling in-ICU deaths in a Malaysian ICU. Methods This was a prospective study in a mixed medical-surgery ICU in a multidisciplinary tertiary referral hospital in Malaysia. Data collection included variables that were defined in Acute Physiology and Chronic Health Evaluation IV (APACHE IV) model. Bayesian Markov Chain Monte Carlo (MCMC) simulation approach was applied in the development of four multivariate logistic regression predictive models for the ICU, where the main outcome measure was in-ICU mortality risk. The performance of the models were assessed through overall model fit, discrimination and calibration measures. Results from the Bayesian models were also compared against results obtained using frequentist maximum likelihood method. Results The study involved 1,286 consecutive ICU admissions between January 1, 2009 and June 30, 2010, of which 1,111 met the inclusion criteria. Patients who were admitted to the ICU were generally younger, predominantly male, with low co-morbidity load and mostly under mechanical ventilation. The overall in-ICU mortality rate was 18.5% and the overall mean Acute Physiology Score (APS) was 68.5. All four models exhibited good discrimination, with area under receiver operating characteristic curve (AUC) values approximately 0.8. Calibration was acceptable (Hosmer-Lemeshow p-values > 0.05) for all models, except for model M3. Model M1 was identified as the model with the best overall performance in this study. Conclusion Four prediction models were proposed, where the best model was chosen based on its overall performance in this study. This study has also demonstrated the promising potential of the Bayesian MCMC approach as an alternative in the analysis and modeling of

  7. A vector relational data modeling approach to Insider threat intelligence

    Science.gov (United States)

    Kelly, Ryan F.; Anderson, Thomas S.

    2016-05-01

    We address the problem of detecting insider threats before they can do harm. In many cases, co-workers notice indications of suspicious activity prior to insider threat attacks. A partial solution to this problem requires an understanding of how information can better traverse the communication network between human intelligence and insider threat analysts. Our approach employs modern mobile communications technology and scale free network architecture to reduce the network distance between human sensors and analysts. In order to solve this problem, we propose a Vector Relational Data Modeling approach to integrate human "sensors," geo-location, and existing visual analytics tools. This integration problem is known to be difficult due to quadratic increases in cost associated with complex integration solutions. A scale free network integration approach using vector relational data modeling is proposed as a method for reducing network distance without increasing cost.

  8. A discrete Lagrangian based direct approach to macroscopic modelling

    Science.gov (United States)

    Sarkar, Saikat; Nowruzpour, Mohsen; Reddy, J. N.; Srinivasa, A. R.

    2017-01-01

    A direct discrete Lagrangian based approach, designed at a length scale of interest, to characterize the response of a body is proposed. The main idea is to understand the dynamics of a deformable body via a Lagrangian corresponding to a coupled interaction of rigid particles in the reduced dimension. We argue that the usual practice of describing the laws of a deformable body in the continuum limit is redundant, because for most of the practical problems, analytical solutions are not available. Since continuum limit is not taken, the framework automatically relaxes the requirement of differentiability of field variables. The discrete Lagrangian based approach is illustrated by deriving an equivalent of the Euler-Bernoulli beam model. A few test examples are solved, which demonstrate that the derived non-local model predicts lower deflections in comparison to classical Euler-Bernoulli beam solutions. We have also included crack propagation in thin structures for isotropic and anisotropic cases using the Lagrangian based approach.

  9. Reconciliation with oneself and with others: From approach to model

    Directory of Open Access Journals (Sweden)

    Nikolić-Ristanović Vesna

    2010-01-01

    Full Text Available The paper intends to present the approach to dealing with war and its consequences which was developed within Victimology Society of Serbia over the last five years, in the framework of Association Joint Action for Truth and Reconciliation (ZAIP. First, the short review of the Association and the process through which ZAIP approach to dealing with a past was developed is presented. Then, the detailed description of the approach itself, with identification of its most important specificities, is presented. In the conclusion, next steps, aimed at development of the model of reconciliation which will have the basis in ZAIP approach and which will be appropriate to social context of Serbia and its surrounding, are suggested.

  10. EXTENDE MODEL OF COMPETITIVITY THROUG APPLICATION OF NEW APPROACH DIRECTIVES

    Directory of Open Access Journals (Sweden)

    Slavko Arsovski

    2009-03-01

    Full Text Available The basic subject of this work is the model of new approach impact on quality and safety products, and competency of our companies. This work represents real hypothesis on the basis of expert's experiences, in regard to that the infrastructure with using new approach directives wasn't examined until now, it isn't known which product or industry of Serbia is related to directives of the new approach and CE mark, and it is not known which are effects of the use of the CE mark. This work should indicate existing quality reserves and product's safety, the level of possible competency improvement and increasing the profit by discharging new approach directive requires.

  11. Tuneable resolution as a systems biology approach for multi-scale, multi-compartment computational models.

    Science.gov (United States)

    Kirschner, Denise E; Hunt, C Anthony; Marino, Simeone; Fallahi-Sichani, Mohammad; Linderman, Jennifer J

    2014-01-01

    The use of multi-scale mathematical and computational models to study complex biological processes is becoming increasingly productive. Multi-scale models span a range of spatial and/or temporal scales and can encompass multi-compartment (e.g., multi-organ) models. Modeling advances are enabling virtual experiments to explore and answer questions that are problematic to address in the wet-lab. Wet-lab experimental technologies now allow scientists to observe, measure, record, and analyze experiments focusing on different system aspects at a variety of biological scales. We need the technical ability to mirror that same flexibility in virtual experiments using multi-scale models. Here we present a new approach, tuneable resolution, which can begin providing that flexibility. Tuneable resolution involves fine- or coarse-graining existing multi-scale models at the user's discretion, allowing adjustment of the level of resolution specific to a question, an experiment, or a scale of interest. Tuneable resolution expands options for revising and validating mechanistic multi-scale models, can extend the longevity of multi-scale models, and may increase computational efficiency. The tuneable resolution approach can be applied to many model types, including differential equation, agent-based, and hybrid models. We demonstrate our tuneable resolution ideas with examples relevant to infectious disease modeling, illustrating key principles at work.

  12. Vibro-acoustics of porous materials - waveguide modeling approach

    DEFF Research Database (Denmark)

    Darula, Radoslav; Sorokin, Sergey V.

    2016-01-01

    The porous material is considered as a compound multi-layered waveguide (i.e. a fluid layer surrounded with elastic layers) with traction free boundary conditions. The attenuation of the vibro-acoustic waves in such a material is assessed. This approach is compared with a conventional Biot's model...... in porous materials....

  13. A novel Monte Carlo approach to hybrid local volatility models

    NARCIS (Netherlands)

    A.W. van der Stoep (Anton); L.A. Grzelak (Lech Aleksander); C.W. Oosterlee (Cornelis)

    2017-01-01

    textabstractWe present in a Monte Carlo simulation framework, a novel approach for the evaluation of hybrid local volatility [Risk, 1994, 7, 18–20], [Int. J. Theor. Appl. Finance, 1998, 1, 61–110] models. In particular, we consider the stochastic local volatility model—see e.g. Lipton et al. [Quant.

  14. Teaching Modeling with Partial Differential Equations: Several Successful Approaches

    Science.gov (United States)

    Myers, Joseph; Trubatch, David; Winkel, Brian

    2008-01-01

    We discuss the introduction and teaching of partial differential equations (heat and wave equations) via modeling physical phenomena, using a new approach that encompasses constructing difference equations and implementing these in a spreadsheet, numerically solving the partial differential equations using the numerical differential equation…

  15. A Behavioral Decision Making Modeling Approach Towards Hedging Services

    NARCIS (Netherlands)

    Pennings, J.M.E.; Candel, M.J.J.M.; Egelkraut, T.M.

    2003-01-01

    This paper takes a behavioral approach toward the market for hedging services. A behavioral decision-making model is developed that provides insight into how and why owner-managers decide the way they do regarding hedging services. Insight into those choice processes reveals information needed by fi

  16. A fuzzy approach to the Weighted Overlap Dominance model

    DEFF Research Database (Denmark)

    Franco de los Rios, Camilo Andres; Hougaard, Jens Leth; Nielsen, Kurt

    2013-01-01

    in an interactive way, where input data can take the form of uniquely-graded or interval-valued information. Here we explore the Weighted Overlap Dominance (WOD) model from a fuzzy perspective and its outranking approach to decision support and multidimensional interval analysis. Firstly, imprecision measures...

  17. Methodological Approach for Modeling of Multienzyme in-pot Processes

    DEFF Research Database (Denmark)

    Andrade Santacoloma, Paloma de Gracia; Roman Martinez, Alicia; Sin, Gürkan;

    2011-01-01

    This paper presents a methodological approach for modeling multi-enzyme in-pot processes. The methodology is exemplified stepwise through the bi-enzymatic production of N-acetyl-D-neuraminic acid (Neu5Ac) from N-acetyl-D-glucosamine (GlcNAc). In this case study, sensitivity analysis is also used...

  18. Towards modeling future energy infrastructures - the ELECTRA system engineering approach

    DEFF Research Database (Denmark)

    Uslar, Mathias; Heussen, Kai

    2016-01-01

    Within this contribution, we provide an overview based on previous work conducted in the ELECTRA project to come up with a consistent method for modeling the ELECTRA WoC approach according to the methods established with the M/490 mandate of the European Commission. We will motivate the use of th...

  19. Pruning Chinese trees : an experimental and modelling approach

    NARCIS (Netherlands)

    Zeng, Bo

    2002-01-01

    Pruning of trees, in which some branches are removed from the lower crown of a tree, has been extensively used in China in silvicultural management for many purposes. With an experimental and modelling approach, the effects of pruning on tree growth and on the harvest of plant material were studied.

  20. Evaluating Interventions with Multimethod Data: A Structural Equation Modeling Approach

    Science.gov (United States)

    Crayen, Claudia; Geiser, Christian; Scheithauer, Herbert; Eid, Michael

    2011-01-01

    In many intervention and evaluation studies, outcome variables are assessed using a multimethod approach comparing multiple groups over time. In this article, we show how evaluation data obtained from a complex multitrait-multimethod-multioccasion-multigroup design can be analyzed with structural equation models. In particular, we show how the…

  1. Teaching Modeling with Partial Differential Equations: Several Successful Approaches

    Science.gov (United States)

    Myers, Joseph; Trubatch, David; Winkel, Brian

    2008-01-01

    We discuss the introduction and teaching of partial differential equations (heat and wave equations) via modeling physical phenomena, using a new approach that encompasses constructing difference equations and implementing these in a spreadsheet, numerically solving the partial differential equations using the numerical differential equation…

  2. A Metacognitive-Motivational Model of Surface Approach to Studying

    Science.gov (United States)

    Spada, Marcantonio M.; Moneta, Giovanni B.

    2012-01-01

    In this study, we put forward and tested a model of how surface approach to studying during examination preparation is influenced by the trait variables of motivation and metacognition and the state variables of avoidance coping and evaluation anxiety. A sample of 528 university students completed, one week before examinations, the following…

  3. A New Approach for Testing the Rasch Model

    Science.gov (United States)

    Kubinger, Klaus D.; Rasch, Dieter; Yanagida, Takuya

    2011-01-01

    Though calibration of an achievement test within psychological and educational context is very often carried out by the Rasch model, data sampling is hardly designed according to statistical foundations. However, Kubinger, Rasch, and Yanagida (2009) recently suggested an approach for the determination of sample size according to a given Type I and…

  4. Comparing State SAT Scores Using a Mixture Modeling Approach

    Science.gov (United States)

    Kim, YoungKoung Rachel

    2009-01-01

    Presented at the national conference for AERA (American Educational Research Association) in April 2009. The large variability of SAT taker population across states makes state-by-state comparisons of the SAT scores challenging. Using a mixture modeling approach, therefore, the current study presents a method of identifying subpopulations in terms…

  5. The Bipolar Approach: A Model for Interdisciplinary Art History Courses.

    Science.gov (United States)

    Calabrese, John A.

    1993-01-01

    Describes a college level art history course based on the opposing concepts of Classicism and Romanticism. Contends that all creative work, such as film or architecture, can be categorized according to this bipolar model. Includes suggestions for objects to study and recommends this approach for art education at all education levels. (CFR)

  6. Non-frontal model based approach to forensic face recognition

    NARCIS (Netherlands)

    Dutta, Abhishek; Veldhuis, Raymond; Spreeuwers, Luuk

    2012-01-01

    In this paper, we propose a non-frontal model based approach which ensures that a face recognition system always gets to compare images having similar view (or pose). This requires a virtual suspect reference set that consists of non-frontal suspect images having pose similar to the surveillance vie

  7. Smeared crack modelling approach for corrosion-induced concrete damage

    DEFF Research Database (Denmark)

    Thybo, Anna Emilie Anusha; Michel, Alexander; Stang, Henrik

    2017-01-01

    compared to experimental data obtained by digital image correlation and published in the literature. Excellent agreements between experimentally observed and numerically predicted crack patterns at the micro and macro scale indicate the capability of the modelling approach to accurately capture corrosion...

  8. Towards modeling future energy infrastructures - the ELECTRA system engineering approach

    DEFF Research Database (Denmark)

    Uslar, Mathias; Heussen, Kai

    2016-01-01

    Within this contribution, we provide an overview based on previous work conducted in the ELECTRA project to come up with a consistent method for modeling the ELECTRA WoC approach according to the methods established with the M/490 mandate of the European Commission. We will motivate the use...

  9. Atomistic approach for modeling metal-semiconductor interfaces

    DEFF Research Database (Denmark)

    Stradi, Daniele; Martinez, Umberto; Blom, Anders

    2016-01-01

    realistic metal-semiconductor interfaces and allows for a direct comparison between theory and experiments via the I–V curve. In particular, it will be demonstrated how doping — and bias — modifies the Schottky barrier, and how finite size models (the slab approach) are unable to describe these interfaces...

  10. Team mental models: techniques, methods, and analytic approaches.

    Science.gov (United States)

    Langan-Fox, J; Code, S; Langfield-Smith, K

    2000-01-01

    Effective team functioning requires the existence of a shared or team mental model among members of a team. However, the best method for measuring team mental models is unclear. Methods reported vary in terms of how mental model content is elicited and analyzed or represented. We review the strengths and weaknesses of vatrious methods that have been used to elicit, represent, and analyze individual and team mental models and provide recommendations for method selection and development. We describe the nature of mental models and review techniques that have been used to elicit and represent them. We focus on a case study on selecting a method to examine team mental models in industry. The processes involved in the selection and development of an appropriate method for eliciting, representing, and analyzing team mental models are described. The criteria for method selection were (a) applicability to the problem under investigation; (b) practical considerations - suitability for collecting data from the targeted research sample; and (c) theoretical rationale - the assumption that associative networks in memory are a basis for the development of mental models. We provide an evaluation of the method matched to the research problem and make recommendations for future research. The practical applications of this research include the provision of a technique for analyzing team mental models in organizations, the development of methods and processes for eliciting a mental model from research participants in their normal work environment, and a survey of available methodologies for mental model research.

  11. CFD Approaches for Modelling Bubble Entrainment by an Impinging Jet

    Directory of Open Access Journals (Sweden)

    Martin Schmidtke

    2009-01-01

    Full Text Available This contribution presents different approaches for the modeling of gas entrainment under water by a plunging jet. Since the generation of bubbles happens on a scale which is smaller than the bubbles, this process cannot be resolved in meso-scale simulations, which include the full length of the jet and its environment. This is why the gas entrainment has to be modeled in meso-scale simulations. In the frame of a Euler-Euler simulation, the local morphology of the phases has to be considered in the drag model. For example, the gas is a continuous phase above the water level but bubbly below the water level. Various drag models are tested and their influence on the gas void fraction below the water level is discussed. The algebraic interface area density (AIAD model applies a drag coefficient for bubbles and a different drag coefficient for the free surface. If the AIAD model is used for the simulation of impinging jets, the gas entrainment depends on the free parameters included in this model. The calculated gas entrainment can be adapted via these parameters. Therefore, an advanced AIAD approach could be used in future for the implementation of models (e.g., correlations for the gas entrainment.

  12. Integrated supply chain inventory model with quality improvement involving controllable lead time and backorder price discount

    Directory of Open Access Journals (Sweden)

    Prashant Jindal

    2016-06-01

    Full Text Available For the past four decades the integrated vendor and buyer supply chain inventory model has been an interesting topic, but quality improvement of defective items in the integrated inventory model with backorder price discount involving controllable lead time has been rarely discussed. The aim of this paper is to minimize the total related cost in the continuous review model by considering the order quantity, reorder point, lead time, process quality, backorder price discount and number of shipment as decision variables. Moreover, we assume that an investment function is used to improve the process quality. The lead time demand follows a normal distribution. In addition, the buyer offers backorder price discount to motivate the customers for possible backorders. There are some defective items in the arrival lot, so its treatment is also taken in account in this paper. We develop an iterative procedure for finding the optimal values of decision variables and numerical example is presented to illustrate the solution procedure. Additionally, sensitivity analysis with respect to major parameters is also carried out.

  13. Approach for workflow modeling using π-calculus

    Institute of Scientific and Technical Information of China (English)

    杨东; 张申生

    2003-01-01

    As a variant of process algebra, π-calculus can describe the interactions between evolving processes. By modeling activity as a process interacting with other processes through ports, this paper presents a new approach: representing workilow models using ~-calculus. As a result, the model can characterize the dynamic behaviors of the workflow process in terms of the LTS ( Labeled Transition Semantics) semantics of π-calculus. The main advantage of the worktlow model's formal semantic is that it allows for verification of the model's properties, such as deadlock-free and normal termination. Moreover, the equivalence of worktlow models can be checked thlx)ugh weak bisimulation theorem in the π-caleulus, thus facilitating the optimizationof business processes.

  14. Approach for workflow modeling using π-calculus

    Institute of Scientific and Technical Information of China (English)

    杨东; 张申生

    2003-01-01

    As a variant of process algebra, π-calculus can describe the interactions between evolving processes. By modeling activity as a process interacting with other processes through ports, this paper presents a new approach: representing workflow models using π-calculus. As a result, the model can characterize the dynamic behaviors of the workflow process in terms of the LTS (Labeled Transition Semantics) semantics of π-calculus. The main advantage of the workflow model's formal semantic is that it allows for verification of the model's properties, such as deadlock-free and normal termination. Moreover, the equivalence of workflow models can be checked through weak bisimulation theorem in the π-calculus, thus facilitating the optimization of business processes.

  15. Multiphysics modeling using COMSOL a first principles approach

    CERN Document Server

    Pryor, Roger W

    2011-01-01

    Multiphysics Modeling Using COMSOL rapidly introduces the senior level undergraduate, graduate or professional scientist or engineer to the art and science of computerized modeling for physical systems and devices. It offers a step-by-step modeling methodology through examples that are linked to the Fundamental Laws of Physics through a First Principles Analysis approach. The text explores a breadth of multiphysics models in coordinate systems that range from 1D to 3D and introduces the readers to the numerical analysis modeling techniques employed in the COMSOL Multiphysics software. After readers have built and run the examples, they will have a much firmer understanding of the concepts, skills, and benefits acquired from the use of computerized modeling techniques to solve their current technological problems and to explore new areas of application for their particular technological areas of interest.

  16. Evaluation of Workflow Management Systems - A Meta Model Approach

    Directory of Open Access Journals (Sweden)

    Michael Rosemann

    1998-11-01

    Full Text Available The automated enactment of processes through the use of workflow management systems enables the outsourcing of the control flow from application systems. By now a large number of systems, that follow different workflow paradigms, are available. This leads to the problem of selecting the appropriate workflow management system for a given situation. In this paper we outline the benefits of a meta model approach for the evaluation and comparison of different workflow management systems. After a general introduction on the topic of meta modeling the meta models of the workflow management systems WorkParty (Siemens Nixdorf and FlowMark (IBM are compared as an example. These product specific meta models can be generalized to meta reference models, which helps to specify a workflow methodology. Exemplary, an organisational reference meta model is presented, which helps users in specifying their requirements for a workflow management system.

  17. Modelling the production of hydrogen (H{sub 2}) using natural gas in Venezuela. An approach involving the sustainability of productive processes; Modelizacion de la produccion de hidrogeno (H{sub 2}) usando gas natural en Venezuela. Una aproximacion a la sostenibilidad del proceso productivo

    Energy Technology Data Exchange (ETDEWEB)

    Rojas Zerpa, Juan [Centro Politecnico Superior, Universidad de Zaragoza (Espana)] email: juancarlosrojas4@yahoo.com

    2009-09-15

    The purpose of the present work is to formulate and evaluate a mathematical model inherent to the process to produce H{sub 2} in Venezuela through reforming natural gas and removing carbon dioxide (CO{sub 2}). The aim of this work is to identify opportunities to recover gas released through the air and from burning natural gas which, in turn, makes it possible to mitigate the effects of global warming. The development of the mathematical model is linear, and includes the production of H{sub 2} the efficiency of the energy conversion process, the cost of the main inputs and resources (natural gas, water and electricity), the cost of reforming and the CO{sub 2} capture system, transport and storage. Three scenarios were considered for the sustainable production of H{sub 2} conventional hydrogen production, H{sub 2} production with direct CO{sub 2} removal, and the production of H{sub 2} with CO{sub 2} removal and increased natural gas from depleted wells (EGR). The results indicate that in Venezuela, more than 1 million tons of hydrogen per year can be produced at a low cost of 1 $/K, with a CO{sub 2} removal effectiveness over 61% and an EGR factor of roughly 8%. In addition, a significant reduction in gas released into the atmosphere would prevent the yearly injection of more than 23 million tons of CO{sub 2} (11,7% of total national CO{sub 2}). The total production cost obtained is significantly lower than that mentioned in the literature, including the target cost by 2017 expected by the U.S. Department of Energy (DOE). [Spanish] El proposito del presente trabajo consiste en la formulacion y evaluacion de un modelo matematico inherente al proceso de produccion de H{sub 2} en Venezuela, mediante el reformado del gas natural y la remocion del dioxido de carbono (CO{sub 2}); con la finalidad de identificar oportunidades para la recuperacion de gas arrojado (venteo y quemado de gas natural) que a su vez permitan mitigar los efectos de calentamiento global. La

  18. Cadmium Handling, Toxicity and Molecular Targets Involved during Pregnancy: Lessons from Experimental Models

    Science.gov (United States)

    Santoyo-Sánchez, Mitzi; Thévenod, Frank; Barbier, Olivier

    2017-01-01

    Even decades after the discovery of Cadmium (Cd) toxicity, research on this heavy metal is still a hot topic in scientific literature: as we wrote this review, more than 1440 scientific articles had been published and listed by the PubMed.gov website during 2017. Cadmium is one of the most common and harmful heavy metals present in our environment. Since pregnancy is a very particular physiological condition that could impact and modify essential pathways involved in the handling of Cd, the prenatal life is a critical stage for exposure to this non-essential element. To give the reader an overview of the possible mechanisms involved in the multiple organ toxic effects in fetuses after the exposure to Cd during pregnancy, we decided to compile some of the most relevant experimental studies performed in experimental models and to summarize the advances in this field such as the Cd distribution and the factors that could alter it (diet, binding-proteins and membrane transporters), the Cd-induced toxicity in dams (preeclampsia, fertility, kidney injury, alteration in essential element homeostasis and bone mineralization), in placenta and in fetus (teratogenicity, central nervous system, liver and kidney). PMID:28737682

  19. The emission of α,ω-diphenylpolyenes: A model involving several molecular structures

    Science.gov (United States)

    Catalán, Javier

    2007-05-01

    Available photophysical evidence for the emission of α,ω-diphenylpolyenes is shown to be consistent with a previously reported model [J. Catalán, J.L.G. de Paz, J. Chem. Phys. 124 (2006) 034306] involving two electronically excited molecular structures of 1B u and C s symmetry, respectively. The 1B u structure is produced by direct light absorption from the all- trans form of the α,ω-diphenylpolyene in the ground state and its emission exhibits mirror symmetry with respect to the absorption of the compound. On the other hand, the C s structure is generated from the 1B u structure of the α,ω-diphenylpolyene by rotation about a C-C single bond in the polyene chain, its emission being red-shifted with respect to the previous one and exhibiting markedly decreased vibrational structure. At room temperature, both emissions give the excitation spectrum, which are ascribed to the first absorption band for the compound. It is shown that some polyenes may exist in more than one structure of C s symmetry in the excited electronic state with lower energy than that of the 1B u state, from which the C s structures are produced. Hence, more than one electronic structure may be involved in the deactivation processes of the 1B u state, which is initially populated upon photo-excitation of the polyene molecule in the ground electronic state.

  20. Simulating mesoscale coastal evolution for decadal coastal management: A new framework integrating multiple, complementary modelling approaches

    Science.gov (United States)

    van Maanen, Barend; Nicholls, Robert J.; French, Jon R.; Barkwith, Andrew; Bonaldo, Davide; Burningham, Helene; Brad Murray, A.; Payo, Andres; Sutherland, James; Thornhill, Gillian; Townend, Ian H.; van der Wegen, Mick; Walkden, Mike J. A.

    2016-03-01

    Coastal and shoreline management increasingly needs to consider morphological change occurring at decadal to centennial timescales, especially that related to climate change and sea-level rise. This requires the development of morphological models operating at a mesoscale, defined by time and length scales of the order 101 to 102 years and 101 to 102 km. So-called 'reduced complexity' models that represent critical processes at scales not much smaller than the primary scale of interest, and are regulated by capturing the critical feedbacks that govern landform behaviour, are proving effective as a means of exploring emergent coastal behaviour at a landscape scale. Such models tend to be computationally efficient and are thus easily applied within a probabilistic framework. At the same time, reductionist models, built upon a more detailed description of hydrodynamic and sediment transport processes, are capable of application at increasingly broad spatial and temporal scales. More qualitative modelling approaches are also emerging that can guide the development and deployment of quantitative models, and these can be supplemented by varied data-driven modelling approaches that can achieve new explanatory insights from observational datasets. Such disparate approaches have hitherto been pursued largely in isolation by mutually exclusive modelling communities. Brought together, they have the potential to facilitate a step change in our ability to simulate the evolution of coastal morphology at scales that are most relevant to managing erosion and flood risk. Here, we advocate and outline a new integrated modelling framework that deploys coupled mesoscale reduced complexity models, reductionist coastal area models, data-driven approaches, and qualitative conceptual models. Integration of these heterogeneous approaches gives rise to model compositions that can potentially resolve decadal- to centennial-scale behaviour of diverse coupled open coast, estuary and inner

  1. A simplified GIS approach to modeling global leaf water isoscapes.

    Directory of Open Access Journals (Sweden)

    Jason B West

    Full Text Available The stable hydrogen (delta(2H and oxygen (delta(18O isotope ratios of organic and inorganic materials record biological and physical processes through the effects of substrate isotopic composition and fractionations that occur as reactions proceed. At large scales, these processes can exhibit spatial predictability because of the effects of coherent climatic patterns over the Earth's surface. Attempts to model spatial variation in the stable isotope ratios of water have been made for decades. Leaf water has a particular importance for some applications, including plant organic materials that record spatial and temporal climate variability and that may be a source of food for migrating animals. It is also an important source of the variability in the isotopic composition of atmospheric gases. Although efforts to model global-scale leaf water isotope ratio spatial variation have been made (especially of delta(18O, significant uncertainty remains in models and their execution across spatial domains. We introduce here a Geographic Information System (GIS approach to the generation of global, spatially-explicit isotope landscapes (= isoscapes of "climate normal" leaf water isotope ratios. We evaluate the approach and the resulting products by comparison with simulation model outputs and point measurements, where obtainable, over the Earth's surface. The isoscapes were generated using biophysical models of isotope fractionation and spatially continuous precipitation isotope and climate layers as input model drivers. Leaf water delta(18O isoscapes produced here generally agreed with latitudinal averages from GCM/biophysical model products, as well as mean values from point measurements. These results show global-scale spatial coherence in leaf water isotope ratios, similar to that observed for precipitation and validate the GIS approach to modeling leaf water isotopes. These results demonstrate that relatively simple models of leaf water enrichment

  2. Community-Involved Learning to Expand Possibilities for Vulnerable Children: A Critical Communicative, Sen's Capability, and Action Research Approach

    Science.gov (United States)

    Kim, Kyung Hi

    2014-01-01

    This research, based on a case study of vulnerable children in Korea, used a mixed methods transformative approach to explore strategies to support and help disadvantaged children. The methodological approach includes three phases: a mixed methods contextual analysis, a qualitative dominant analysis based on Sen's capability approach and critical…

  3. An EMQ inventory model for defective products involving rework and sales team's initiatives-dependent demand

    Science.gov (United States)

    Priyan, S.; Uthayakumar, R.

    2015-07-01

    This paper investigates the issue of an economic manufacturing quantity model for defective products involving imperfect production processes and rework. We consider that the demand is sensitive to promotional efforts/sales teams' initiatives as well as the setup cost can be reduced through further investment. It also assumes that fixed quantity multiple installments of the finished batch are delivered to customers at a fixed interval of time. The long-run average cost function is derived and its convexity is proved via differential calculus. An effective iterative solution procedure is developed to achieve optimal replenishment lot-size, setup cost and the initiatives of sales teams so that the total cost of system is minimized. Numerical and sensitivity analyses are performed to evaluate the outcome of the proposed solution procedure presented in this research.

  4. System Dynamics Modelling of the Processes Involving the Maintenance of the Naive T Cell Repertoire

    CERN Document Server

    Figueredo, Grazziela P; Whitbrook, Amanda

    2010-01-01

    The study of immune system aging, i.e. immunosenescence, is a relatively new research topic. It deals with understanding the processes of immunodegradation that indicate signs of functionality loss possibly leading to death. Even though it is not possible to prevent immunosenescence, there is great benefit in comprehending its causes, which may help to reverse some of the damage done and thus improve life expectancy. One of the main factors influencing the process of immunosenescence is the number and phenotypical variety of naive T cells in an individual. This work presents a review of immunosenescence, proposes system dynamics modelling of the processes involving the maintenance of the naive T cell repertoire and presents some preliminary results.

  5. Empirical versus modelling approaches to the estimation of measurement uncertainty caused by primary sampling.

    Science.gov (United States)

    Lyn, Jennifer A; Ramsey, Michael H; Damant, Andrew P; Wood, Roger

    2007-12-01

    Measurement uncertainty is a vital issue within analytical science. There are strong arguments that primary sampling should be considered the first and perhaps the most influential step in the measurement process. Increasingly, analytical laboratories are required to report measurement results to clients together with estimates of the uncertainty. Furthermore, these estimates can be used when pursuing regulation enforcement to decide whether a measured analyte concentration is above a threshold value. With its recognised importance in analytical measurement, the question arises of 'what is the most appropriate method to estimate the measurement uncertainty?'. Two broad methods for uncertainty estimation are identified, the modelling method and the empirical method. In modelling, the estimation of uncertainty involves the identification, quantification and summation (as variances) of each potential source of uncertainty. This approach has been applied to purely analytical systems, but becomes increasingly problematic in identifying all of such sources when it is applied to primary sampling. Applications of this methodology to sampling often utilise long-established theoretical models of sampling and adopt the assumption that a 'correct' sampling protocol will ensure a representative sample. The empirical approach to uncertainty estimation involves replicated measurements from either inter-organisational trials and/or internal method validation and quality control. A more simple method involves duplicating sampling and analysis, by one organisation, for a small proportion of the total number of samples. This has proven to be a suitable alternative to these often expensive and time-consuming trials, in routine surveillance and one-off surveys, especially where heterogeneity is the main source of uncertainty. A case study of aflatoxins in pistachio nuts is used to broadly demonstrate the strengths and weakness of the two methods of uncertainty estimation. The estimate

  6. Processes and parameters involved in modeling radionuclide transport from bedded salt repositories. Final report. Technical memorandum

    Energy Technology Data Exchange (ETDEWEB)

    Evenson, D.E.; Prickett, T.A.; Showalter, P.A.

    1979-07-01

    The parameters necessary to model radionuclide transport in salt beds are identified and described. A proposed plan for disposal of the radioactive wastes generated by nuclear power plants is to store waste canisters in repository sites contained in stable salt formations approximately 600 meters below the ground surface. Among the principal radioactive wastes contained in these canisters will be radioactive isotopes of neptunium, americium, uranium, and plutonium along with many highly radioactive fission products. A concern with this form of waste disposal is the possibility of ground-water flow occurring in the salt beds and endangering water supplies and the public health. Specifically, the research investigated the processes involved in the movement of radioactive wastes from the repository site by groundwater flow. Since the radioactive waste canisters also generate heat, temperature is an important factor. Among the processes affecting movement of radioactive wastes from a repository site in a salt bed are thermal conduction, groundwater movement, ion exchange, radioactive decay, dissolution and precipitation of salt, dispersion and diffusion, adsorption, and thermomigration. In addition, structural changes in the salt beds as a result of temperature changes are important. Based upon the half-lives of the radioactive wastes, he period of concern is on the order of a million years. As a result, major geologic phenomena that could affect both the salt bed and groundwater flow in the salt beds was considered. These phenomena include items such as volcanism, faulting, erosion, glaciation, and the impact of meteorites. CDM reviewed all of the critical processes involved in regional groundwater movement of radioactive wastes and identified and described the parameters that must be included to mathematically model their behavior. In addition, CDM briefly reviewed available echniques to measure these parameters.

  7. A generalized quarter car modelling approach with frame flexibility and other nonlocal effects

    Indian Academy of Sciences (India)

    HUSAIN KANCHWALA; ANINDYA CHATTERJEE

    2017-07-01

    Quarter-car models are popular, simple, unidirectional in kinematics and enable quicker computation than full-car models. However, they do not account for three other wheels and their suspensions, nor for the frame’s flexibility, mass distribution and damping. Here we propose a generalized quarter-car modelling approach, incorporating both the frame as well as other-wheel ground contacts. Our approach is linear, uses Laplace transforms, involves vertical motions of key points of interest and has intermediate complexity with improved realism. Our model uses baseline suspension parameters and responses to step force inputs at suspensionattachment locations on the frame. Subsequently, new suspension parameters and unsprung mass compliance parameters can be incorporated, for which relevant formulas are given. The final expression for the transfer function, between ground displacement and body point response, is approximated using model orderreduction. A simple Matlab code is provided that enables quick parametric studies. Finally, a parametric study and wheel hop analysis are performed for a realistic numerical example. Frequency and time domain responses obtained show clearly the effects of other wheels, which are outside the scope of usual quarter-car models. The displacements obtained from our model are compared against those of the usual quarter-car model and show ways in which predictions of the quarter-car model include errors that can be reduced in our approach. In summary, our approach has intermediate complexity between that of a full-car model and a quarter-car model, and offers corresponding intermediate detail and realism.

  8. Polynomial Chaos Expansion Approach to Interest Rate Models

    Directory of Open Access Journals (Sweden)

    Luca Di Persio

    2015-01-01

    Full Text Available The Polynomial Chaos Expansion (PCE technique allows us to recover a finite second-order random variable exploiting suitable linear combinations of orthogonal polynomials which are functions of a given stochastic quantity ξ, hence acting as a kind of random basis. The PCE methodology has been developed as a mathematically rigorous Uncertainty Quantification (UQ method which aims at providing reliable numerical estimates for some uncertain physical quantities defining the dynamic of certain engineering models and their related simulations. In the present paper, we use the PCE approach in order to analyze some equity and interest rate models. In particular, we take into consideration those models which are based on, for example, the Geometric Brownian Motion, the Vasicek model, and the CIR model. We present theoretical as well as related concrete numerical approximation results considering, without loss of generality, the one-dimensional case. We also provide both an efficiency study and an accuracy study of our approach by comparing its outputs with the ones obtained adopting the Monte Carlo approach, both in its standard and its enhanced version.

  9. Popularity Modeling for Mobile Apps: A Sequential Approach.

    Science.gov (United States)

    Zhu, Hengshu; Liu, Chuanren; Ge, Yong; Xiong, Hui; Chen, Enhong

    2015-07-01

    The popularity information in App stores, such as chart rankings, user ratings, and user reviews, provides an unprecedented opportunity to understand user experiences with mobile Apps, learn the process of adoption of mobile Apps, and thus enables better mobile App services. While the importance of popularity information is well recognized in the literature, the use of the popularity information for mobile App services is still fragmented and under-explored. To this end, in this paper, we propose a sequential approach based on hidden Markov model (HMM) for modeling the popularity information of mobile Apps toward mobile App services. Specifically, we first propose a popularity based HMM (PHMM) to model the sequences of the heterogeneous popularity observations of mobile Apps. Then, we introduce a bipartite based method to precluster the popularity observations. This can help to learn the parameters and initial values of the PHMM efficiently. Furthermore, we demonstrate that the PHMM is a general model and can be applicable for various mobile App services, such as trend based App recommendation, rating and review spam detection, and ranking fraud detection. Finally, we validate our approach on two real-world data sets collected from the Apple Appstore. Experimental results clearly validate both the effectiveness and efficiency of the proposed popularity modeling approach.

  10. On a Markovian approach for modeling passive solar devices

    Energy Technology Data Exchange (ETDEWEB)

    Bottazzi, F.; Liebling, T.M. (Chaire de Recherche Operationelle, Ecole Polytechnique Federale de Lausanne (Switzerland)); Scartezzini, J.L.; Nygaard-Ferguson, M. (Lab. d' Energie Solaire et de Physique du Batiment, Ecole Polytechnique Federale de Lausanne (Switzerland))

    1991-01-01

    Stochastic models for the analysis of the energy and thermal comfort performances of passive solar devices have been increasingly studied for over a decade. A new approach to thermal building modeling, based on Markov chains, is proposed here to combine both the accuracy of traditional dynamic simulation with the practical advantages of simplified methods. A main difficulty of the Markovian approach is the discretization of the system variables. Efficient procedures have been developed to carry out this discretization and several numerical experiments have been performed to analyze the possibilities and limitations of the Markovian model. Despite its restrictive assumptions, it will be shown that accurate results are indeed obtained by this method. However, due to discretization, computer memory reqirements are more than inversely proportional to accuracy. (orig.).

  11. Disturbed state concept as unified constitutive modeling approach

    Directory of Open Access Journals (Sweden)

    Chandrakant S. Desai

    2016-06-01

    Full Text Available A unified constitutive modeling approach is highly desirable to characterize a wide range of engineering materials subjected simultaneously to the effect of a number of factors such as elastic, plastic and creep deformations, stress path, volume change, microcracking leading to fracture, failure and softening, stiffening, and mechanical and environmental forces. There are hardly available such unified models. The disturbed state concept (DSC is considered to be a unified approach and is able to provide material characterization for almost all of the above factors. This paper presents a description of the DSC, and statements for determination of parameters based on triaxial, multiaxial and interface tests. Statements of DSC and validation at the specimen level and at the boundary value problem levels are also presented. An extensive list of publications by the author and others is provided at the end. The DSC is considered to be a unique and versatile procedure for modeling behaviors of engineering materials and interfaces.

  12. Disturbed state concept as unified constitutive modeling approach

    Institute of Scientific and Technical Information of China (English)

    Chandrakant S. Desai

    2016-01-01

    A unified constitutive modeling approach is highly desirable to characterize a wide range of engineering materials subjected simultaneously to the effect of a number of factors such as elastic, plastic and creep deformations, stress path, volume change, microcracking leading to fracture, failure and softening, stiffening, and mechanical and environmental forces. There are hardly available such unified models. The disturbed state concept (DSC) is considered to be a unified approach and is able to provide material characterization for almost all of the above factors. This paper presents a description of the DSC, and statements for determination of parameters based on triaxial, multiaxial and interface tests. Statements of DSC and validation at the specimen level and at the boundary value problem levels are also presented. An extensive list of publications by the author and others is provided at the end. The DSC is considered to be a unique and versatile procedure for modeling behaviors of engineering materials and interfaces.

  13. Proposal: A Hybrid Dictionary Modelling Approach for Malay Tweet Normalization

    Science.gov (United States)

    Muhamad, Nor Azlizawati Binti; Idris, Norisma; Arshi Saloot, Mohammad

    2017-02-01

    Malay Twitter message presents a special deviation from the original language. Malay Tweet widely used currently by Twitter users, especially at Malaya archipelago. Thus, it is important to make a normalization system which can translated Malay Tweet language into the standard Malay language. Some researchers have conducted in natural language processing which mainly focuses on normalizing English Twitter messages, while few studies have been done for normalize Malay Tweets. This paper proposes an approach to normalize Malay Twitter messages based on hybrid dictionary modelling methods. This approach normalizes noisy Malay twitter messages such as colloquially language, novel words, and interjections into standard Malay language. This research will be used Language Model and N-grams model.

  14. Towards a CPN-Based Modelling Approach for Reconciling Verification and Implementation of Protocol Models

    DEFF Research Database (Denmark)

    Simonsen, Kent Inge; Kristensen, Lars Michael

    2013-01-01

    and implementation. Our approach has been developed in the context of the Coloured Petri Nets (CPNs) modelling language. We illustrate our approach by presenting a descriptive specification model of the Websocket protocol which is currently under development by the Internet Engineering Task Force (IETF), and we show......Formal modelling of protocols is often aimed at one specific purpose such as verification or automatically generating an implementation. This leads to models that are useful for one purpose, but not for others. Being able to derive models for verification and implementation from a single model...

  15. Involvement of EphB1 receptors signalling in models of inflammatory and neuropathic pain.

    Directory of Open Access Journals (Sweden)

    Vincent Cibert-Goton

    Full Text Available EphB receptors tyrosine kinases and ephrinB ligands were first identified as guidance molecules involved in the establishment of topographical mapping and connectivity in the nervous system during development. Later in development and into adulthood their primary role would switch from guidance to activity-dependent modulation of synaptic efficacy. In sensory systems, they play a role in both the onset of inflammatory and neuropathic pain, and in the establishment of central sensitisation, an NMDA-mediated form of synaptic plasticity thought to underlie most forms of chronic pain. We studied wild type and EphB1 knockout mice in a range of inflammatory and neuropathic pain models to determine 1, whether EphB1 expression is necessary for the onset and/or maintenance of persistent pain, regardless of origin; 2, whether in these models cellular and molecular changes, e.g. phosphorylation of the NR2B subunit of the NMDA receptor, increased c-fos expression or microglial activation, associated with the onset of pain, are affected by the lack of functional EphB1 receptors. Differences in phenotype were examined behaviourally, anatomically, biochemically and electrophysiologically. Our results establish firstly, that functional EphB1 receptors are not essential for the development of normal nociception, thermal or mechanical sensitivity. Secondly, they demonstrate a widespread involvement of EphB1 receptors in chronic pain. NR2B phosphorylation, c-fos expression and microglial activation are all reduced in EphB1 knockout mice. This last finding is intriguing, since microglial activation is supposedly triggered directly by primary afferents, therefore it was not expected to be affected. Interestingly, in some models of long-term pain (days, mechanical and thermal hyperalgesia develop both in wild type and EphB1 knockout mice, but recovery is faster in the latter, indicating that in particular models these receptors are required for the maintenance

  16. ON SOME APPROACHES TO ECONOMICMATHEMATICAL MODELING OF SMALL BUSINESS

    Directory of Open Access Journals (Sweden)

    Orlov A. I.

    2015-04-01

    Full Text Available Small business is an important part of modern Russian economy. We give a wide panorama developed by us of possible approaches to the construction of economic-mathematical models that may be useful to describe the dynamics of small businesses, as well as management. As for the description of certain problems of small business can use a variety of types of economic-mathematical and econometric models, we found it useful to consider a fairly wide range of such models, which resulted in quite a short description of the specific models. In this description of the models brought to such a level that an experienced professional in the field of economic-mathematical modeling could, if necessary, to develop their own specific model to the stage of design formulas and numerical results. Particular attention is paid to the use of statistical methods of non-numeric data, the most pressing at the moment. Are considered the problems of economic-mathematical modeling in solving problems of small business marketing. We have accumulated some experience in application of the methodology of economic-mathematical modeling in solving practical problems in small business marketing, in particular in the field of consumer goods and industrial purposes, educational services, as well as in the analysis and modeling of inflation, taxation and others. In marketing models of decision making theory we apply rankings and ratings. Is considered the problem of comparing averages. We present some models of the life cycle of small businesses - flow model projects, model of capture niches, and model of niche selection. We discuss the development of research on economic-mathematical modeling of small businesses

  17. A validated approach for modeling collapse of steel structures

    Science.gov (United States)

    Saykin, Vitaliy Victorovich

    A civil engineering structure is faced with many hazardous conditions such as blasts, earthquakes, hurricanes, tornadoes, floods, and fires during its lifetime. Even though structures are designed for credible events that can happen during a lifetime of the structure, extreme events do happen and cause catastrophic failures. Understanding the causes and effects of structural collapse is now at the core of critical areas of national need. One factor that makes studying structural collapse difficult is the lack of full-scale structural collapse experimental test results against which researchers could validate their proposed collapse modeling approaches. The goal of this work is the creation of an element deletion strategy based on fracture models for use in validated prediction of collapse of steel structures. The current work reviews the state-of-the-art of finite element deletion strategies for use in collapse modeling of structures. It is shown that current approaches to element deletion in collapse modeling do not take into account stress triaxiality in vulnerable areas of the structure, which is important for proper fracture and element deletion modeling. The report then reviews triaxiality and its role in fracture prediction. It is shown that fracture in ductile materials is a function of triaxiality. It is also shown that, depending on the triaxiality range, different fracture mechanisms are active and should be accounted for. An approach using semi-empirical fracture models as a function of triaxiality are employed. The models to determine fracture initiation, softening and subsequent finite element deletion are outlined. This procedure allows for stress-displacement softening at an integration point of a finite element in order to subsequently remove the element. This approach avoids abrupt changes in the stress that would create dynamic instabilities, thus making the results more reliable and accurate. The calibration and validation of these models are

  18. The promoter competition assay (PCA): a new approach to identify motifs involved in the transcriptional activity of reporter genes.

    Science.gov (United States)

    Hube, Florent; Myal, Yvonne; Leygue, Etienne

    2006-05-01

    Identifying particular motifs responsible for promoter activity is a crucial step toward the development of new gene-based preventive and therapeutic strategies. However, to date, experimental methods to study promoter activity remain limited. We present in this report a promoter competition assay designed to identify, within a given promoter region, motifs critical for its activity. This assay consists in co-transfecting the promoter to be analyzed and double-stranded oligonucleotides which will compete for the binding of transcription factors. Using the recently characterized SBEM promoter as model, we first delineated the feasibility of the method and optimized the experimental conditions. We then identified, within an 87-bp region responsible for a strong expression of the reporter gene, an octamer-binding site essential for its transcriptional regulation. The importance of this motif has been confirmed by site-directed mutagenesis. The promoter competition assay appears to be a fast and efficient approach to identify, within a given promoter sequence, sites critical for its activity.

  19. GEOSPATIAL MODELLING APPROACH FOR 3D URBAN DENSIFICATION DEVELOPMENTS

    Directory of Open Access Journals (Sweden)

    O. Koziatek

    2016-06-01

    Full Text Available With growing populations, economic pressures, and the need for sustainable practices, many urban regions are rapidly densifying developments in the vertical built dimension with mid- and high-rise buildings. The location of these buildings can be projected based on key factors that are attractive to urban planners, developers, and potential buyers. Current research in this area includes various modelling approaches, such as cellular automata and agent-based modelling, but the results are mostly linked to raster grids as the smallest spatial units that operate in two spatial dimensions. Therefore, the objective of this research is to develop a geospatial model that operates on irregular spatial tessellations to model mid- and high-rise buildings in three spatial dimensions (3D. The proposed model is based on the integration of GIS, fuzzy multi-criteria evaluation (MCE, and 3D GIS-based procedural modelling. Part of the City of Surrey, within the Metro Vancouver Region, Canada, has been used to present the simulations of the generated 3D building objects. The proposed 3D modelling approach was developed using ESRI’s CityEngine software and the Computer Generated Architecture (CGA language.

  20. Geospatial Modelling Approach for 3d Urban Densification Developments

    Science.gov (United States)

    Koziatek, O.; Dragićević, S.; Li, S.

    2016-06-01

    With growing populations, economic pressures, and the need for sustainable practices, many urban regions are rapidly densifying developments in the vertical built dimension with mid- and high-rise buildings. The location of these buildings can be projected based on key factors that are attractive to urban planners, developers, and potential buyers. Current research in this area includes various modelling approaches, such as cellular automata and agent-based modelling, but the results are mostly linked to raster grids as the smallest spatial units that operate in two spatial dimensions. Therefore, the objective of this research is to develop a geospatial model that operates on irregular spatial tessellations to model mid- and high-rise buildings in three spatial dimensions (3D). The proposed model is based on the integration of GIS, fuzzy multi-criteria evaluation (MCE), and 3D GIS-based procedural modelling. Part of the City of Surrey, within the Metro Vancouver Region, Canada, has been used to present the simulations of the generated 3D building objects. The proposed 3D modelling approach was developed using ESRI's CityEngine software and the Computer Generated Architecture (CGA) language.