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Sample records for adolescents computer modelling

  1. Computable models

    CERN Document Server

    Turner, Raymond

    2009-01-01

    Computational models can be found everywhere in present day science and engineering. In providing a logical framework and foundation for the specification and design of specification languages, Raymond Turner uses this framework to introduce and study computable models. In doing so he presents the first systematic attempt to provide computational models with a logical foundation. Computable models have wide-ranging applications from programming language semantics and specification languages, through to knowledge representation languages and formalism for natural language semantics. They are al

  2. Excessive recreational computer use and food consumption behaviour among adolescents.

    NARCIS (Netherlands)

    L. Shi (Lu); Y. Mao (Yuping)

    2010-01-01

    textabstractINTRODUCTION: Using the 2005 California Health Interview Survey (CHIS) data, we explore the association between excessive recreational computer use and specific food consumption behavior among California's adolescents aged 12-17. METHOD: The adolescent component of CHIS 2005 measured the

  3. Computational neurogenetic modeling

    CERN Document Server

    Benuskova, Lubica

    2010-01-01

    Computational Neurogenetic Modeling is a student text, introducing the scope and problems of a new scientific discipline - Computational Neurogenetic Modeling (CNGM). CNGM is concerned with the study and development of dynamic neuronal models for modeling brain functions with respect to genes and dynamic interactions between genes. These include neural network models and their integration with gene network models. This new area brings together knowledge from various scientific disciplines, such as computer and information science, neuroscience and cognitive science, genetics and molecular biol

  4. The Computational Development of Reinforcement Learning during Adolescence.

    Directory of Open Access Journals (Sweden)

    Stefano Palminteri

    2016-06-01

    Full Text Available Adolescence is a period of life characterised by changes in learning and decision-making. Learning and decision-making do not rely on a unitary system, but instead require the coordination of different cognitive processes that can be mathematically formalised as dissociable computational modules. Here, we aimed to trace the developmental time-course of the computational modules responsible for learning from reward or punishment, and learning from counterfactual feedback. Adolescents and adults carried out a novel reinforcement learning paradigm in which participants learned the association between cues and probabilistic outcomes, where the outcomes differed in valence (reward versus punishment and feedback was either partial or complete (either the outcome of the chosen option only, or the outcomes of both the chosen and unchosen option, were displayed. Computational strategies changed during development: whereas adolescents' behaviour was better explained by a basic reinforcement learning algorithm, adults' behaviour integrated increasingly complex computational features, namely a counterfactual learning module (enabling enhanced performance in the presence of complete feedback and a value contextualisation module (enabling symmetrical reward and punishment learning. Unlike adults, adolescent performance did not benefit from counterfactual (complete feedback. In addition, while adults learned symmetrically from both reward and punishment, adolescents learned from reward but were less likely to learn from punishment. This tendency to rely on rewards and not to consider alternative consequences of actions might contribute to our understanding of decision-making in adolescence.

  5. Biomechanical evaluation of predictive parameters of progression in adolescent isthmic spondylolisthesis: a computer modeling and simulation study

    Directory of Open Access Journals (Sweden)

    Sevrain Amandine

    2012-01-01

    Full Text Available Abstract Background Pelvic incidence, sacral slope and slip percentage have been shown to be important predicting factors for assessing the risk of progression of low- and high-grade spondylolisthesis. Biomechanical factors, which affect the stress distribution and the mechanisms involved in the vertebral slippage, may also influence the risk of progression, but they are still not well known. The objective was to biomechanically evaluate how geometric sacral parameters influence shear and normal stress at the lumbosacral junction in spondylolisthesis. Methods A finite element model of a low-grade L5-S1 spondylolisthesis was constructed, including the morphology of the spine, pelvis and rib cage based on measurements from biplanar radiographs of a patient. Variations provided on this model aimed to study the effects on low grade spondylolisthesis as well as reproduce high grade spondylolisthesis. Normal and shear stresses at the lumbosacral junction were analyzed under various pelvic incidences, sacral slopes and slip percentages. Their influence on progression risk was statistically analyzed using a one-way analysis of variance. Results Stresses were mainly concentrated on the growth plate of S1, on the intervertebral disc of L5-S1, and ahead the sacral dome for low grade spondylolisthesis. For high grade spondylolisthesis, more important compression and shear stresses were seen in the anterior part of the growth plate and disc as compared to the lateral and posterior areas. Stress magnitudes over this area increased with slip percentage, sacral slope and pelvic incidence. Strong correlations were found between pelvic incidence and the resulting compression and shear stresses in the growth plate and intervertebral disc at the L5-S1 junction. Conclusions Progression of the slippage is mostly affected by a movement and an increase of stresses at the lumbosacral junction in accordance with spino-pelvic parameters. The statistical results provide

  6. Modeling Trusted Computing

    Institute of Scientific and Technical Information of China (English)

    CHEN Shuyi; WEN Yingyou; ZHAO Hong

    2006-01-01

    In this paper, a formal approach based on predicate logic is proposed for representing and reasoning of trusted computing models. Predicates are defined to represent the characteristics of the objects and the relationship among these objects in a trusted system according to trusted computing specifications. Inference rules of trusted relation are given too. With the semantics proposed, some trusted computing models are formalized and verified, which shows that Predicate calculus logic provides a general and effective method for modeling and reasoning trusted computing systems.

  7. The Computational Development of Reinforcement Learning during Adolescence

    Science.gov (United States)

    Palminteri, Stefano; Coricelli, Giorgio; Blakemore, Sarah-Jayne

    2016-01-01

    Adolescence is a period of life characterised by changes in learning and decision-making. Learning and decision-making do not rely on a unitary system, but instead require the coordination of different cognitive processes that can be mathematically formalised as dissociable computational modules. Here, we aimed to trace the developmental time-course of the computational modules responsible for learning from reward or punishment, and learning from counterfactual feedback. Adolescents and adults carried out a novel reinforcement learning paradigm in which participants learned the association between cues and probabilistic outcomes, where the outcomes differed in valence (reward versus punishment) and feedback was either partial or complete (either the outcome of the chosen option only, or the outcomes of both the chosen and unchosen option, were displayed). Computational strategies changed during development: whereas adolescents’ behaviour was better explained by a basic reinforcement learning algorithm, adults’ behaviour integrated increasingly complex computational features, namely a counterfactual learning module (enabling enhanced performance in the presence of complete feedback) and a value contextualisation module (enabling symmetrical reward and punishment learning). Unlike adults, adolescent performance did not benefit from counterfactual (complete) feedback. In addition, while adults learned symmetrically from both reward and punishment, adolescents learned from reward but were less likely to learn from punishment. This tendency to rely on rewards and not to consider alternative consequences of actions might contribute to our understanding of decision-making in adolescence. PMID:27322574

  8. Computer Modeling and Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Pronskikh, V. S. [Fermilab

    2014-05-09

    Verification and validation of computer codes and models used in simulation are two aspects of the scientific practice of high importance and have recently been discussed by philosophers of science. While verification is predominantly associated with the correctness of the way a model is represented by a computer code or algorithm, validation more often refers to model’s relation to the real world and its intended use. It has been argued that because complex simulations are generally not transparent to a practitioner, the Duhem problem can arise for verification and validation due to their entanglement; such an entanglement makes it impossible to distinguish whether a coding error or model’s general inadequacy to its target should be blamed in the case of the model failure. I argue that in order to disentangle verification and validation, a clear distinction between computer modeling (construction of mathematical computer models of elementary processes) and simulation (construction of models of composite objects and processes by means of numerical experimenting with them) needs to be made. Holding on to that distinction, I propose to relate verification (based on theoretical strategies such as inferences) to modeling and validation, which shares the common epistemology with experimentation, to simulation. To explain reasons of their intermittent entanglement I propose a weberian ideal-typical model of modeling and simulation as roles in practice. I suggest an approach to alleviate the Duhem problem for verification and validation generally applicable in practice and based on differences in epistemic strategies and scopes

  9. Computational Intelligence, Cyber Security and Computational Models

    CERN Document Server

    Anitha, R; Lekshmi, R; Kumar, M; Bonato, Anthony; Graña, Manuel

    2014-01-01

    This book contains cutting-edge research material presented by researchers, engineers, developers, and practitioners from academia and industry at the International Conference on Computational Intelligence, Cyber Security and Computational Models (ICC3) organized by PSG College of Technology, Coimbatore, India during December 19–21, 2013. The materials in the book include theory and applications for design, analysis, and modeling of computational intelligence and security. The book will be useful material for students, researchers, professionals, and academicians. It will help in understanding current research trends and findings and future scope of research in computational intelligence, cyber security, and computational models.

  10. Computational human body models

    NARCIS (Netherlands)

    Wismans, J.S.H.M.; Happee, R.; Dommelen, J.A.W. van

    2005-01-01

    Computational human body models are widely used for automotive crashsafety research and design and as such have significantly contributed to a reduction of traffic injuries and fatalities. Currently crash simulations are mainly performed using models based on crash-dummies. However crash dummies dif

  11. Perceived problems with computer gaming and internet use among adolescents

    DEFF Research Database (Denmark)

    Holstein, Bjørn E; Pedersen, Trine Pagh; Bendtsen, Pernille

    2014-01-01

    new measures of perceived problems related to computer and console gaming and internet use among adolescents are appropriate, reliable and valid for use in non-clinical surveys about young people's everyday life and behaviour. These new measures do not assess Internet Gaming Disorder as it is listed......BACKGROUND: Existing instruments for measuring problematic computer and console gaming and internet use are often lengthy and often based on a pathological perspective. The objective was to develop and present a new and short non-clinical measurement tool for perceived problems related to computer...... on weekdays on computer- and console-gaming and internet use for communication and surfing. The outcome measures were three indexes on perceived problems related to computer and console gaming and internet use. RESULTS: The three new indexes showed high face validity and acceptable internal consistency. Most...

  12. Understanding Student Computational Thinking with Computational Modeling

    CERN Document Server

    Aiken, John M; Douglas, Scott S; Burk, John B; Scanlon, Erin M; Thoms, Brian D; Schatz, Michael F

    2012-01-01

    Recently, the National Research Council's framework for next generation science standards highlighted "computational thinking" as one of its "fundamental practices". Students taking a physics course that employed the Arizona State University's Modeling Instruction curriculum were taught to construct computational models of physical systems. Student computational thinking was assessed using a proctored programming assignment, written essay, and a series of think-aloud interviews, where the students produced and discussed a computational model of a baseball in motion via a high-level programming environment (VPython). Roughly a third of the students in the study were successful in completing the programming assignment. Student success on this assessment was tied to how students synthesized their knowledge of physics and computation. On the essay and interview assessments, students displayed unique views of the relationship between force and motion; those who spoke of this relationship in causal (rather than obs...

  13. Excessive recreational computer use and food consumption behaviour among adolescents

    Directory of Open Access Journals (Sweden)

    Mao Yuping

    2010-08-01

    Full Text Available Abstract Introduction Using the 2005 California Health Interview Survey (CHIS data, we explore the association between excessive recreational computer use and specific food consumption behavior among California's adolescents aged 12-17. Method The adolescent component of CHIS 2005 measured the respondents' average number of hours spent on viewing TV on a weekday, the average number of hours spent on viewing TV on a weekend day, the average number of hours spent on playing with a computer on a weekday, and the average number of hours spent on playing with computers on a weekend day. We recode these four continuous variables into four variables of "excessive media use," and define more than three hours of using a medium per day as "excessive." These four variables are then used in logistic regressions to predict different food consumption behaviors on the previous day: having fast food, eating sugary food more than once, drinking sugary drinks more than once, and eating more than five servings of fruits and vegetables. We use the following variables as covariates in the logistic regressions: age, gender, race/ethnicity, parental education, household poverty status, whether born in the U.S., and whether living with two parents. Results Having fast food on the previous day is associated with excessive weekday TV viewing (O.R. = 1.38, p Conclusion Excessive recreational computer use independently predicts undesirable eating behaviors that could lead to overweight and obesity. Preventive measures ranging from parental/youth counseling to content regulations might be addressing the potential undesirable influence from excessive computer use on eating behaviors among children and adolescents.

  14. [The effects of computer-use on adolescents].

    Science.gov (United States)

    Stefănescu, C; Chele, Gabriela; Chiriţă, V; Chiriţă, Roxana; Mavros, M; Macarie, G; Ilinca, M

    2005-01-01

    Computers continue to play a vital role in today's generation. The need for information about the effects of computers on their users also increases. The purpose of this study is to investigate how children and adolescents use a computer and to explore the beneficial and harmful effects of computer use on children's mental and physical health. The studied group of samples comprised 69 subjects, aged between 13 and 18 years, who answered to a questionnaire. The parents of the children also answered another questionnaire with the same subject. Data have been statistically processed using the program SPSS. The results were obtained about computer use and the pathological use was identified. Some children spend much time on computers, 4% more than five hours/day. 41% of the parents believe that the usage of the computer is favorable to the children's mental and physical health and development, 49% of parents believe that the computer may be harmful. 1.4% of the children had pathological use of the computer.

  15. LHCb computing model

    CERN Document Server

    Frank, M; Pacheco, Andreu

    1998-01-01

    This document is a first attempt to describe the LHCb computing model. The CPU power needed to process data for the event filter and reconstruction is estimated to be 2.2 \\Theta 106 MIPS. This will be installed at the experiment and will be reused during non data-taking periods for reprocessing. The maximal I/O of these activities is estimated to be around 40 MB/s.We have studied three basic models concerning the placement of the CPU resources for the other computing activities, Monte Carlo-simulation (1:4 \\Theta 106 MIPS) and physics analysis (0:5 \\Theta 106 MIPS): CPU resources may either be located at the physicist's homelab, national computer centres (Regional Centres) or at CERN.The CPU resources foreseen for analysis are sufficient to allow 100 concurrent analyses. It is assumed that physicists will work in physics groups that produce analysis data at an average rate of 4.2 MB/s or 11 TB per month. However, producing these group analysis data requires reading capabilities of 660 MB/s. It is further assu...

  16. Educational Computer Use in Leisure Contexts: A Phenomenological Study of Adolescents' Experiences at Internet Cafes

    Science.gov (United States)

    Cilesiz, Sebnem

    2009-01-01

    Computer use is a widespread leisure activity for adolescents. Leisure contexts, such as Internet cafes, constitute specific social environments for computer use and may hold significant educational potential. This article reports a phenomenological study of adolescents' experiences of educational computer use at Internet cafes in Turkey. The…

  17. The Antares computing model

    Energy Technology Data Exchange (ETDEWEB)

    Kopper, Claudio, E-mail: claudio.kopper@nikhef.nl [NIKHEF, Science Park 105, 1098 XG Amsterdam (Netherlands)

    2013-10-11

    Completed in 2008, Antares is now the largest water Cherenkov neutrino telescope in the Northern Hemisphere. Its main goal is to detect neutrinos from galactic and extra-galactic sources. Due to the high background rate of atmospheric muons and the high level of bioluminescence, several on-line and off-line filtering algorithms have to be applied to the raw data taken by the instrument. To be able to handle this data stream, a dedicated computing infrastructure has been set up. The paper covers the main aspects of the current official Antares computing model. This includes an overview of on-line and off-line data handling and storage. In addition, the current usage of the “IceTray” software framework for Antares data processing is highlighted. Finally, an overview of the data storage formats used for high-level analysis is given.

  18. Adolescent Psychosocial Development: A Review of Longitudinal Models and Research

    Science.gov (United States)

    Meeus, Wim

    2016-01-01

    This review used 4 types of longitudinal models (descriptive models, prediction models, developmental sequence models and longitudinal mediation models) to identify regular patterns of psychosocial development in adolescence. Eight patterns of adolescent development were observed across countries: (1) adolescent maturation in multiple…

  19. Computer products usage and prevalence of computer related musculoskeletal discomfort among adolescents.

    Science.gov (United States)

    Siu, Damian Chi Hong; Tse, Lap Ah; Yu, Ignatius Tak Sun; Griffiths, Sian Meryl

    2009-01-01

    The objective of this study was to investigate the pattern of computer related activities among Hong Kong adolescents and the prevalence of musculoskeletal discomfort by anatomic sites. This study used a questionnaire-based cross-sectional design. Students from Year 1 to 7 of six local high schools were invited to complete a Student Musculoskeletal Health Questionnaire and Computer Usage Questionnaire. Complete data for 3,191 questionnaires was obtained, giving an overall response rate of 95.5%. High prevalence (68.3%) of musculoskeletal discomfort related to using computer was reported among Hong Kong children and adolescents in the past 12 months. Shoulder (37.7%) and neck (35.0%) were the most frequently involved body parts for both genders, while female students reported higher rates of musculoskeletal discomfort in each of the specified anatomic site than male students. Students who reported musculoskeletal discomfort were significantly older and spent a longer time on computer related activities. The associations found in this cross-sectional study should be confirmed by subsequent longitudinal studies. An urgent need in healthy computing environment is demanded among Hong Kong adolescents.

  20. Plasticity modeling & computation

    CERN Document Server

    Borja, Ronaldo I

    2013-01-01

    There have been many excellent books written on the subject of plastic deformation in solids, but rarely can one find a textbook on this subject. “Plasticity Modeling & Computation” is a textbook written specifically for students who want to learn the theoretical, mathematical, and computational aspects of inelastic deformation in solids. It adopts a simple narrative style that is not mathematically overbearing, and has been written to emulate a professor giving a lecture on this subject inside a classroom. Each section is written to provide a balance between the relevant equations and the explanations behind them. Where relevant, sections end with one or more exercises designed to reinforce the understanding of the “lecture.” Color figures enhance the presentation and make the book very pleasant to read. For professors planning to use this textbook for their classes, the contents are sufficient for Parts A and B that can be taught in sequence over a period of two semesters or quarters.

  1. Computer Game Addiction in Adolescents and Its Relationship to Chronotype and Personality

    OpenAIRE

    Christian Vollmer; Christoph Randler; Mehmet Barış Horzum; Tuncay Ayas

    2014-01-01

    This study assessed the relationship between computer game addiction and computer game usage time, age, gender, BIG-5 personality, and chronotype. Seven hundred and forty-one adolescents from Turkey responded to questionnaires on these topics. We found that computer game addiction, computer game usage time, and chronotype were related with each other. Evening-oriented, younger, and male students had higher computer gam...

  2. A Novel Forensic Computing Model

    Institute of Scientific and Technical Information of China (English)

    XU Yunfeng; LU Yansheng

    2006-01-01

    According to the requirement of computer forensic and network forensic, a novel forensic computing model is presented, which exploits XML/OEM/RM data model, Data fusion technology, forensic knowledgebase, inference mechanism of expert system and evidence mining engine. This model takes advantage of flexility and openness, so it can be widely used in mining evidence.

  3. Prevalence of musculoskeletal pain in adolescents and association with computer and videogame use

    Directory of Open Access Journals (Sweden)

    Georgia Rodrigues Reis Silva

    2016-04-01

    Full Text Available Abstract Objective: This study investigated the presence of musculoskeletal symptoms in high school adolescents from public schools and its association with electronic device use. Methods: The sample consisted of 961 boys and girls aged 14–19 years who answered a questionnaire regarding the use of computers and electronic games, and questions about pain symptoms and physical activity. Furthermore, anthropometric assessments of all volunteers were performed. The chi-squared test and a multiple logistic regression model were used for the inferential analysis. Results: The presence of musculoskeletal pain symptoms was reported by 65.1% of the adolescents, being more prevalent in the thoracolumbar spine (46.9%, followed by pain in the upper limbs, representing 20% of complaints. The mean time of use for computers and electronic games was 1.720 and 583 minutes per week, respectively. The excessive use of electronic devices was demonstrated to be a risk factor for cervical and lumbar pain. Female gender was associated with the presence of pain in different body parts. Presence of a paid job was associated with cervical pain. Conclusion: A high prevalence of musculoskeletal pain in adolescents, as well as an increased amount of time using digital devices was observed. However, it was only possible to observe an association between the increased use of these devices and the presence of cervical and low back pain.

  4. Computational modeling in biomechanics

    CERN Document Server

    Mofrad, Mohammad

    2010-01-01

    This book provides a glimpse of the diverse and important roles that modern computational technology is playing in various areas of biomechanics. It includes unique chapters on ab initio quantum mechanical, molecular dynamic and scale coupling methods..

  5. Analysis of attitudes toward computer networks and Internet addiction of Taiwanese adolescents.

    Science.gov (United States)

    Tsai, C C; Lin, S S

    2001-06-01

    This study explored the interplay between young people's attitudes toward computer networks and Internet addiction. Ninety possible Internet addicts were selected for examination after analyzing the questionnaire responses of an initial sample of 753 Taiwanese high school adolescents. It was found that the subjects' attitudes toward computer networks could explain many aspects of Internet addiction. However, actual behaviors on Internet usage and perceptions on the usefulness of Internet were more important than affective responses toward computer networks in predicting adolescents' Internet addiction.

  6. Computational modelling flow and transport

    NARCIS (Netherlands)

    Stelling, G.S.; Booij, N.

    1999-01-01

    Lecture notes CT wa4340. Derivation of equations using balance principles; numerical treatment of ordinary differential equations; time dependent partial differential equations; the strucure of a computer model:DUFLO; usage of numerical models.

  7. Computation models of discourse

    Energy Technology Data Exchange (ETDEWEB)

    Brady, M.; Berwick, R.C.

    1983-01-01

    This book presents papers on artificial intelligence and natural language. Topics considered include recognizing intentions from natural language utterances, cooperative responses from a portable natural language database query system, natural language generation as a computational problem, focusing in the comprehension of definite anaphora, and factors in forming discourse-dependent descriptions.

  8. Computational models of syntactic acquisition.

    Science.gov (United States)

    Yang, Charles

    2012-03-01

    The computational approach to syntactic acquisition can be fruitfully pursued by integrating results and perspectives from computer science, linguistics, and developmental psychology. In this article, we first review some key results in computational learning theory and their implications for language acquisition. We then turn to examine specific learning models, some of which exploit distributional information in the input while others rely on a constrained space of hypotheses, yet both approaches share a common set of characteristics to overcome the learning problem. We conclude with a discussion of how computational models connects with the empirical study of child grammar, making the case for computationally tractable, psychologically plausible and developmentally realistic models of acquisition. WIREs Cogn Sci 2012, 3:205-213. doi: 10.1002/wcs.1154 For further resources related to this article, please visit the WIREs website.

  9. Computer Anxiety: A Comparison of Adolescents with and without a History of Specific Language Impairment (SLI)

    Science.gov (United States)

    Conti-Ramsden, Gina; Durkin, Kevin; Walker, Allan J.

    2010-01-01

    Individuals who are anxious about computers may be at a disadvantage in their learning. This investigation focused on the use of home computers for educational purposes. It compared computer anxiety in adolescents with and without a history of special needs related to language difficulties. Participants were 55 17-year-olds with specific language…

  10. Trust Models in Ubiquitous Computing

    DEFF Research Database (Denmark)

    Nielsen, Mogens; Krukow, Karl; Sassone, Vladimiro

    2008-01-01

    We recapture some of the arguments for trust-based technologies in ubiquitous computing, followed by a brief survey of some of the models of trust that have been introduced in this respect. Based on this, we argue for the need of more formal and foundational trust models.......We recapture some of the arguments for trust-based technologies in ubiquitous computing, followed by a brief survey of some of the models of trust that have been introduced in this respect. Based on this, we argue for the need of more formal and foundational trust models....

  11. Patient-Specific Computational Modeling

    CERN Document Server

    Peña, Estefanía

    2012-01-01

    This book addresses patient-specific modeling. It integrates computational modeling, experimental procedures, imagine clinical segmentation and mesh generation with the finite element method (FEM) to solve problems in computational biomedicine and bioengineering. Specific areas of interest include cardiovascular problems, ocular and muscular systems and soft tissue modeling. Patient-specific modeling has been the subject of serious research over the last seven years and interest in the area is continually growing and this area is expected to further develop in the near future.

  12. Integrated Computational Model Development

    Science.gov (United States)

    2014-03-01

    68.5%, 9.6% and 21.9%, respectively. The alloy density and Vickers microhardness were ρ = 8.23 ± 0.01 g/cm3 and Hv = 5288 ± 1 MPa. [3...and 3-D. Techniques to mechanically test materials at smaller scales were developed to better inform the deformation models. Also methods were...situ microscale tension testing technique was adapted to enable microscale fatigue testing on tensile dog-bone specimens. Microscale tensile fatigue

  13. Component Breakout Computer Model

    Science.gov (United States)

    1987-04-29

    Weapon Systems: A Policy Analysis." The Rand Graduate Institute. November 1983. Boger . D. "Statistical Models for Estimating Overhead Costs." M. S...SQUARE SCREEN PROGRAM BO DLS 70 LOCATE 3,5 100 PRINT " I I I I I I I I I I I I I I t I I I t I I i iiitiii I I I I i t I i 110 LOCATE 4,5 I 20...GOTO 4620 4610 REM ***********«««*«««**#«***********#******»,*###!^5|[^,„<c#,5|c„ dl -r C^M EED SUPPORT .c.50 REM A6(6)...N0 OF EMPLOYEES 4660 IF

  14. Efficient Computational Model of Hysteresis

    Science.gov (United States)

    Shields, Joel

    2005-01-01

    A recently developed mathematical model of the output (displacement) versus the input (applied voltage) of a piezoelectric transducer accounts for hysteresis. For the sake of computational speed, the model is kept simple by neglecting the dynamic behavior of the transducer. Hence, the model applies to static and quasistatic displacements only. A piezoelectric transducer of the type to which the model applies is used as an actuator in a computer-based control system to effect fine position adjustments. Because the response time of the rest of such a system is usually much greater than that of a piezoelectric transducer, the model remains an acceptably close approximation for the purpose of control computations, even though the dynamics are neglected. The model (see Figure 1) represents an electrically parallel, mechanically series combination of backlash elements, each having a unique deadband width and output gain. The zeroth element in the parallel combination has zero deadband width and, hence, represents a linear component of the input/output relationship. The other elements, which have nonzero deadband widths, are used to model the nonlinear components of the hysteresis loop. The deadband widths and output gains of the elements are computed from experimental displacement-versus-voltage data. The hysteresis curve calculated by use of this model is piecewise linear beyond deadband limits.

  15. Design and evaluation protocol of "FATaintPHAT", a computer-tailored intervention to prevent excessive weight gain in adolescents

    NARCIS (Netherlands)

    N.P.M. Ezendam (Nicole); A. Oenema (Anke); P.M. van de Looij-Jansen (Petra); J. Brug (Hans)

    2008-01-01

    textabstractComputer tailoring may be a promising technique for prevention of overweight in adolescents. However, very few well-developed, evidence-based computer-tailored interventions are available for this target group. We developed and evaluated a computer-tailored intervention for adolescents t

  16. Design and evaluation protocol of "FATaintPHAT", a computer-tailored intervention to prevent excessive weight gain in adolescents

    NARCIS (Netherlands)

    N.P.M. Ezendam (Nicole); A. Oenema (Anke); P.M. van de Looij-Jansen (Petra); J. Brug (Hans)

    2007-01-01

    textabstractComputer tailoring may be a promising technique for prevention of overweight in adolescents. However, very few well-developed, evidence-based computer-tailored interventions are available for this target group. We developed and evaluated a computer-tailored intervention for adolescents t

  17. Computer Modelling of Dynamic Processes

    Directory of Open Access Journals (Sweden)

    B. Rybakin

    2000-10-01

    Full Text Available Results of numerical modeling of dynamic problems are summed in the article up. These problems are characteristic for various areas of human activity, in particular for problem solving in ecology. The following problems are considered in the present work: computer modeling of dynamic effects on elastic-plastic bodies, calculation and determination of performances of gas streams in gas cleaning equipment, modeling of biogas formation processes.

  18. Computational models of complex systems

    CERN Document Server

    Dabbaghian, Vahid

    2014-01-01

    Computational and mathematical models provide us with the opportunities to investigate the complexities of real world problems. They allow us to apply our best analytical methods to define problems in a clearly mathematical manner and exhaustively test our solutions before committing expensive resources. This is made possible by assuming parameter(s) in a bounded environment, allowing for controllable experimentation, not always possible in live scenarios. For example, simulation of computational models allows the testing of theories in a manner that is both fundamentally deductive and experimental in nature. The main ingredients for such research ideas come from multiple disciplines and the importance of interdisciplinary research is well recognized by the scientific community. This book provides a window to the novel endeavours of the research communities to present their works by highlighting the value of computational modelling as a research tool when investigating complex systems. We hope that the reader...

  19. Computational models of adult neurogenesis

    Science.gov (United States)

    Cecchi, Guillermo A.; Magnasco, Marcelo O.

    2005-10-01

    Experimental results in recent years have shown that adult neurogenesis is a significant phenomenon in the mammalian brain. Little is known, however, about the functional role played by the generation and destruction of neurons in the context of an adult brain. Here, we propose two models where new projection neurons are incorporated. We show that in both models, using incorporation and removal of neurons as a computational tool, it is possible to achieve a higher computational efficiency that in purely static, synapse-learning-driven networks. We also discuss the implication for understanding the role of adult neurogenesis in specific brain areas like the olfactory bulb and the dentate gyrus.

  20. Computational Modeling of Simulation Tests.

    Science.gov (United States)

    1980-06-01

    Mexico , March 1979. 14. Kinney, G. F.,.::. IeiN, .hoce 1h Ir, McMillan, p. 57, 1962. 15. Courant and Friedrichs, ,U: r. on moca an.: Jho...AD 79 275 NEW MEXICO UNIV ALBUGUERGUE ERIC H WANG CIVIL ENGINE-ETC F/6 18/3 COMPUTATIONAL MODELING OF SIMULATION TESTS.(U) JUN 80 6 LEIGH, W CHOWN, B...COMPUTATIONAL MODELING OF SIMULATION TESTS00 0G. Leigh W. Chown B. Harrison Eric H. Wang Civil Engineering Research Facility University of New Mexico

  1. Developing a New Computer Game Attitude Scale for Taiwanese Early Adolescents

    Science.gov (United States)

    Liu, Eric Zhi-Feng; Lee, Chun-Yi; Chen, Jen-Huang

    2013-01-01

    With ever increasing exposure to computer games, gaining an understanding of the attitudes held by young adolescents toward such activities is crucial; however, few studies have provided scales with which to accomplish this. This study revisited the Computer Game Attitude Scale developed by Chappell and Taylor in 1997, reworking the overall…

  2. Psychological Trauma as a Reason for Computer Game Addiction among Adolescents

    Science.gov (United States)

    Oskenbay, Fariza; Tolegenova, Aliya; Kalymbetova, Elmira; Chung, Man Cheung; Faizullina, Aida; Jakupov, Maksat

    2016-01-01

    This study explores psychological trauma as a reason for computer game addiction among adolescents. The findings of this study show that there is a connection between psychological trauma and computer game addiction. Some psychologists note that the main cause of any type of addiction derives from psychological trauma, and that finding such…

  3. Adolescent differences in knee stability following computer-assisted anterior cruciate ligament reconstruction

    Directory of Open Access Journals (Sweden)

    Melissa A. Christino

    2014-12-01

    Full Text Available Anterior cruciate ligament (ACL surgery is being increasingly performed in the adolescent population. Computer navigation offers a reliable way to quantitatively measure knee stability during ACL reconstruction. A retrospective review of all adolescent patients (<18 years old who underwent computer-assisted primary single bundle ACL reconstruction by a single surgeon from 2007 to 2012 was performed. The average age was 15.8 years (SD 3.3. Female adolescents were found to have higher internal rotation than male adolescents both pre- (25.6° vs 21.7°, P=0.026 and post-reconstruction (20.1° vs 15.1°, P=0.005. Compared to adults, adolescents demonstrated significantly higher internal rotation both pre- (23.3° vs 21.5°, P=0.047 and post-reconstruction (17.1° vs 14.4°, P=0.003. They also had higher total rotation both pre- (40.9° vs 38.4°, P=0.02 and post-reconstruction when compared to adults (31.56° vs 28.67°, P=0.005. In adolescent patients, anterior translation was corrected more than rotation. Females had higher pre- and residual post-reconstruction internal rotation compared to males. When compared to adults, adolescents had increased internal rotation and total rotation both pre- and post-reconstruction. 

  4. Climate Modeling Computing Needs Assessment

    Science.gov (United States)

    Petraska, K. E.; McCabe, J. D.

    2011-12-01

    This paper discusses early findings of an assessment of computing needs for NASA science, engineering and flight communities. The purpose of this assessment is to document a comprehensive set of computing needs that will allow us to better evaluate whether our computing assets are adequately structured to meet evolving demand. The early results are interesting, already pointing out improvements we can make today to get more out of the computing capacity we have, as well as potential game changing innovations for the future in how we apply information technology to science computing. Our objective is to learn how to leverage our resources in the best way possible to do more science for less money. Our approach in this assessment is threefold: Development of use case studies for science workflows; Creating a taxonomy and structure for describing science computing requirements; and characterizing agency computing, analysis, and visualization resources. As projects evolve, science data sets increase in a number of ways: in size, scope, timelines, complexity, and fidelity. Generating, processing, moving, and analyzing these data sets places distinct and discernable requirements on underlying computing, analysis, storage, and visualization systems. The initial focus group for this assessment is the Earth Science modeling community within NASA's Science Mission Directorate (SMD). As the assessment evolves, this focus will expand to other science communities across the agency. We will discuss our use cases, our framework for requirements and our characterizations, as well as our interview process, what we learned and how we plan to improve our materials after using them in the first round of interviews in the Earth Science Modeling community. We will describe our plans for how to expand this assessment, first into the Earth Science data analysis and remote sensing communities, and then throughout the full community of science, engineering and flight at NASA.

  5. Precursors of adolescent substance use from early childhood and early adolescence: testing a developmental cascade model.

    Science.gov (United States)

    Sitnick, Stephanie L; Shaw, Daniel S; Hyde, Luke W

    2014-02-01

    This study examined developmentally salient risk and protective factors of adolescent substance use assessed during early childhood and early adolescence using a sample of 310 low-income boys. Child problem behavior and proximal family risk and protective factors (i.e., parenting and maternal depression) during early childhood, as well as child and family factors and peer deviant behavior during adolescence, were explored as potential precursors to later substance use during adolescence using structural equation modeling. Results revealed that early childhood risk and protective factors (i.e., child externalizing problems, mothers' depressive symptomatology, and nurturant parenting) were indirectly related to substance use at the age of 17 via risk and protective factors during early and middle adolescence (i.e., parental knowledge and externalizing problems). The implications of these findings for early prevention and intervention are discussed.

  6. Computer Profiling Based Model for Investigation

    Directory of Open Access Journals (Sweden)

    Neeraj Choudhary

    2011-10-01

    Full Text Available Computer profiling is used for computer forensic analysis, and proposes and elaborates on a novel model for use in computer profiling, the computer profiling object model. The computer profiling object model is an information model which models a computer as objects with various attributes and inter-relationships. These together provide the information necessary for a human investigator or an automated reasoning engine to make judgments as to the probable usage and evidentiary value of a computer system. The computer profiling object model can be implemented so as to support automated analysis to provide an investigator with the informationneeded to decide whether manual analysis is required.

  7. FORENSIC COMPUTING MODELS: TECHNICAL OVERVIEW

    Directory of Open Access Journals (Sweden)

    Gulshan Shrivastava

    2012-05-01

    Full Text Available In this paper, we deal with introducing a technique of digital forensics for reconstruction of events or evidences after the commitment of a crime through any of the digital devices. It shows a clear transparency between Computer Forensics and Digital Forensics and gives a brief description about the classification of Digital Forensics. It has also been described that how the emergences of various digital forensic models help digital forensic practitioners and examiners in doing digital forensics. Further, discussed Merits and Demerits of the required models and review of every major model.

  8. Pervasive Computing and Prosopopoietic Modelling

    DEFF Research Database (Denmark)

    Michelsen, Anders Ib

    2011-01-01

    that have spread vertiginiously since Mark Weiser coined the term ‘pervasive’, e.g., digitalised sensoring, monitoring, effectuation, intelligence, and display. Whereas Weiser’s original perspective may seem fulfilled since computing is everywhere, in his and Seely Brown’s (1997) terms, ‘invisible...... into the other. It also indicates a generative creation that itself points to important issues of ontology with methodological implications for the design of computing. In this article these implications will be conceptualised as prosopopoietic modeling on the basis of Bernward Joerges introduction......, pointing to a principal role of the paradoxical distinction/complicity within the computational heritage in three cases: a. Prosopopoietic aspects of John von Neumann’s First Draft of a Report on the EDVAC from 1945. b. Herbert Simon’s notion of simulation in The Science of the Artificial from the 1970s. c...

  9. Parallel computing in enterprise modeling.

    Energy Technology Data Exchange (ETDEWEB)

    Goldsby, Michael E.; Armstrong, Robert C.; Shneider, Max S.; Vanderveen, Keith; Ray, Jaideep; Heath, Zach; Allan, Benjamin A.

    2008-08-01

    This report presents the results of our efforts to apply high-performance computing to entity-based simulations with a multi-use plugin for parallel computing. We use the term 'Entity-based simulation' to describe a class of simulation which includes both discrete event simulation and agent based simulation. What simulations of this class share, and what differs from more traditional models, is that the result sought is emergent from a large number of contributing entities. Logistic, economic and social simulations are members of this class where things or people are organized or self-organize to produce a solution. Entity-based problems never have an a priori ergodic principle that will greatly simplify calculations. Because the results of entity-based simulations can only be realized at scale, scalable computing is de rigueur for large problems. Having said that, the absence of a spatial organizing principal makes the decomposition of the problem onto processors problematic. In addition, practitioners in this domain commonly use the Java programming language which presents its own problems in a high-performance setting. The plugin we have developed, called the Parallel Particle Data Model, overcomes both of these obstacles and is now being used by two Sandia frameworks: the Decision Analysis Center, and the Seldon social simulation facility. While the ability to engage U.S.-sized problems is now available to the Decision Analysis Center, this plugin is central to the success of Seldon. Because Seldon relies on computationally intensive cognitive sub-models, this work is necessary to achieve the scale necessary for realistic results. With the recent upheavals in the financial markets, and the inscrutability of terrorist activity, this simulation domain will likely need a capability with ever greater fidelity. High-performance computing will play an important part in enabling that greater fidelity.

  10. Cosmic logic: a computational model

    Science.gov (United States)

    Vanchurin, Vitaly

    2016-02-01

    We initiate a formal study of logical inferences in context of the measure problem in cosmology or what we call cosmic logic. We describe a simple computational model of cosmic logic suitable for analysis of, for example, discretized cosmological systems. The construction is based on a particular model of computation, developed by Alan Turing, with cosmic observers (CO), cosmic measures (CM) and cosmic symmetries (CS) described by Turing machines. CO machines always start with a blank tape and CM machines take CO's Turing number (also known as description number or Gödel number) as input and output the corresponding probability. Similarly, CS machines take CO's Turing number as input, but output either one if the CO machines are in the same equivalence class or zero otherwise. We argue that CS machines are more fundamental than CM machines and, thus, should be used as building blocks in constructing CM machines. We prove the non-computability of a CS machine which discriminates between two classes of CO machines: mortal that halts in finite time and immortal that runs forever. In context of eternal inflation this result implies that it is impossible to construct CM machines to compute probabilities on the set of all CO machines using cut-off prescriptions. The cut-off measures can still be used if the set is reduced to include only machines which halt after a finite and predetermined number of steps.

  11. Minimal models of multidimensional computations.

    Directory of Open Access Journals (Sweden)

    Jeffrey D Fitzgerald

    2011-03-01

    Full Text Available The multidimensional computations performed by many biological systems are often characterized with limited information about the correlations between inputs and outputs. Given this limitation, our approach is to construct the maximum noise entropy response function of the system, leading to a closed-form and minimally biased model consistent with a given set of constraints on the input/output moments; the result is equivalent to conditional random field models from machine learning. For systems with binary outputs, such as neurons encoding sensory stimuli, the maximum noise entropy models are logistic functions whose arguments depend on the constraints. A constraint on the average output turns the binary maximum noise entropy models into minimum mutual information models, allowing for the calculation of the information content of the constraints and an information theoretic characterization of the system's computations. We use this approach to analyze the nonlinear input/output functions in macaque retina and thalamus; although these systems have been previously shown to be responsive to two input dimensions, the functional form of the response function in this reduced space had not been unambiguously identified. A second order model based on the logistic function is found to be both necessary and sufficient to accurately describe the neural responses to naturalistic stimuli, accounting for an average of 93% of the mutual information with a small number of parameters. Thus, despite the fact that the stimulus is highly non-Gaussian, the vast majority of the information in the neural responses is related to first and second order correlations. Our results suggest a principled and unbiased way to model multidimensional computations and determine the statistics of the inputs that are being encoded in the outputs.

  12. Computer-Aided Modeling Framework

    DEFF Research Database (Denmark)

    Fedorova, Marina; Sin, Gürkan; Gani, Rafiqul

    Models are playing important roles in design and analysis of chemicals based products and the processes that manufacture them. Computer-aided methods and tools have the potential to reduce the number of experiments, which can be expensive and time consuming, and there is a benefit of working...... with a case study related to the modeling of a catalytic membrane reactor coupling dehydrogenation of ethylbenzene with hydrogenation of nitrobenzene, and, for the performance evaluation of an atomizer product. In the first case study, the reactor type is where the reactions are thermodynamically limited...... the yield and the quality of the output components and that will make possible to evaluate and improve the product properties. In the case of the atomizer performance, the droplet size, number and their evaporation are analyzed through a multiscale model. The mathematical equations of the model...

  13. Intervention Strategies with Adolescents: The Newton Model.

    Science.gov (United States)

    Green, Matt

    The problem of adolescent drug/alcohol abuse seems to have once again intensified during the 1980s. When the school is the only constant in an adolescent's life and when those same teenagers bring drugs and alcohol-related problems to school, the school has an obligation to implement change. The first step is identification of the problem. Beyond…

  14. Cosmic Logic: a Computational Model

    CERN Document Server

    Vanchurin, Vitaly

    2015-01-01

    We describe a simple computational model of cosmic logic suitable for analysis of, for example, discretized cosmological systems. The construction is based on a particular model of computation, developed by Alan Turing, with cosmic observers (CO), cosmic measures (CM) and cosmic symmetries (CS) described by Turing machines. CO machines always start with a blank tape and CM machines take CO's Turing number (also known as description number or G{\\" o}del number) as input and output the corresponding probability. Similarly, CS machines take CO's Turing number as input, but output either one if the CO machines are in the same equivalence class or zero otherwise. We argue that CS machines are more fundamental than CM machines and, thus, should be used as building blocks in constructing CM machines. We prove the non-computability of a CS machine which discriminates between two classes of CO machines: mortal that halts in finite time and immortal that runs forever. In context of eternal inflation this result implies...

  15. Computer-associated health complaints and sources of ergonomic instructions in computer-related issues among Finnish adolescents: A cross-sectional study

    OpenAIRE

    Ketola Ritva L; Saarni Lea A; Hakala Paula T; Rahkola Erja T; Salminen Jouko J; Rimpelä Arja H

    2010-01-01

    Abstract Background The use of computers has increased among adolescents, as have musculoskeletal symptoms. There is evidence that these symptoms can be reduced through an ergonomics approach and through education. The purpose of this study was to examine where adolescents had received ergonomic instructions related to computer use, and whether receiving these instructions was associated with a reduced prevalence of computer-associated health complaints. Methods Mailed survey with nationally ...

  16. Computational Modeling in Tissue Engineering

    CERN Document Server

    2013-01-01

    One of the major challenges in tissue engineering is the translation of biological knowledge on complex cell and tissue behavior into a predictive and robust engineering process. Mastering this complexity is an essential step towards clinical applications of tissue engineering. This volume discusses computational modeling tools that allow studying the biological complexity in a more quantitative way. More specifically, computational tools can help in:  (i) quantifying and optimizing the tissue engineering product, e.g. by adapting scaffold design to optimize micro-environmental signals or by adapting selection criteria to improve homogeneity of the selected cell population; (ii) quantifying and optimizing the tissue engineering process, e.g. by adapting bioreactor design to improve quality and quantity of the final product; and (iii) assessing the influence of the in vivo environment on the behavior of the tissue engineering product, e.g. by investigating vascular ingrowth. The book presents examples of each...

  17. Ergonomic and Anthropometric Considerations of the Use of Computers in Schools by Adolescents

    Science.gov (United States)

    Jermolajew, Anna M.; Newhouse, C. Paul

    2003-01-01

    Over the past decade there has been an explosion in the provision of computing facilities in schools for student use. However, there is concern that the development of these facilities has often given little regard to the ergonomics of the design for use by children, particularly adolescents. This paper reports on a study that investigated the…

  18. MODEL IDENTIFICATION AND COMPUTER ALGEBRA.

    Science.gov (United States)

    Bollen, Kenneth A; Bauldry, Shawn

    2010-10-07

    Multiequation models that contain observed or latent variables are common in the social sciences. To determine whether unique parameter values exist for such models, one needs to assess model identification. In practice analysts rely on empirical checks that evaluate the singularity of the information matrix evaluated at sample estimates of parameters. The discrepancy between estimates and population values, the limitations of numerical assessments of ranks, and the difference between local and global identification make this practice less than perfect. In this paper we outline how to use computer algebra systems (CAS) to determine the local and global identification of multiequation models with or without latent variables. We demonstrate a symbolic CAS approach to local identification and develop a CAS approach to obtain explicit algebraic solutions for each of the model parameters. We illustrate the procedures with several examples, including a new proof of the identification of a model for handling missing data using auxiliary variables. We present an identification procedure for Structural Equation Models that makes use of CAS and that is a useful complement to current methods.

  19. Los Alamos Center for Computer Security formal computer security model

    Energy Technology Data Exchange (ETDEWEB)

    Dreicer, J.S.; Hunteman, W.J.; Markin, J.T.

    1989-01-01

    This paper provides a brief presentation of the formal computer security model currently being developed at the Los Alamos Department of Energy (DOE) Center for Computer Security (CCS). The need to test and verify DOE computer security policy implementation first motivated this effort. The actual analytical model was a result of the integration of current research in computer security and previous modeling and research experiences. The model is being developed to define a generic view of the computer and network security domains, to provide a theoretical basis for the design of a security model, and to address the limitations of present formal mathematical models for computer security. The fundamental objective of computer security is to prevent the unauthorized and unaccountable access to a system. The inherent vulnerabilities of computer systems result in various threats from unauthorized access. The foundation of the Los Alamos DOE CCS model is a series of functionally dependent probability equations, relations, and expressions. The model is undergoing continued discrimination and evolution. We expect to apply the model to the discipline of the Bell and LaPadula abstract sets of objects and subjects. 6 refs.

  20. Computer Game Addiction in Adolescents and Its Relationship to Chronotype and Personality

    Directory of Open Access Journals (Sweden)

    Christian Vollmer

    2014-01-01

    Full Text Available This study assessed the relationship between computer game addiction and computer game usage time, age, gender, BIG-5 personality, and chronotype. Seven hundred and forty-one adolescents from Turkey responded to questionnaires on these topics. We found that computer game addiction, computer game usage time, and chronotype were related with each other. Evening-oriented, younger, and male students had higher computer game addiction scores than morning-oriented, older, and female students. Furthermore, extraverted and agreeable students reported lower computer game addiction. No significant relationship was observed between students’ computer game addiction scores and openness to experience, conscientiousness. We conclude that evening types may be more prone to computer game addiction than morning types.

  1. International Conference on Computational Intelligence, Cyber Security, and Computational Models

    CERN Document Server

    Ramasamy, Vijayalakshmi; Sheen, Shina; Veeramani, C; Bonato, Anthony; Batten, Lynn

    2016-01-01

    This book aims at promoting high-quality research by researchers and practitioners from academia and industry at the International Conference on Computational Intelligence, Cyber Security, and Computational Models ICC3 2015 organized by PSG College of Technology, Coimbatore, India during December 17 – 19, 2015. This book enriches with innovations in broad areas of research like computational modeling, computational intelligence and cyber security. These emerging inter disciplinary research areas have helped to solve multifaceted problems and gained lot of attention in recent years. This encompasses theory and applications, to provide design, analysis and modeling of the aforementioned key areas.

  2. Are computer and cell phone use associated with body mass index and overweight? A population study among twin adolescents

    Directory of Open Access Journals (Sweden)

    Pulkkinen Lea

    2007-02-01

    Full Text Available Abstract Background Overweight in children and adolescents has reached dimensions of a global epidemic during recent years. Simultaneously, information and communication technology use has rapidly increased. Methods A population-based sample of Finnish twins born in 1983–1987 (N = 4098 was assessed by self-report questionnaires at 17 y during 2000–2005. The association of overweight (defined by Cole's BMI-for-age cut-offs with computer and cell phone use and ownership was analyzed by logistic regression and their association with BMI by linear regression models. The effect of twinship was taken into account by correcting for clustered sampling of families. All models were adjusted for gender, physical exercise, and parents' education and occupational class. Results The proportion of adolescents who did not have a computer at home decreased from 18% to 8% from 2000 to 2005. Compared to them, having a home computer (without an Internet connection was associated with a higher risk of overweight (odds ratio 2.3, 95% CI 1.4 to 3.8 and BMI (beta coefficient 0.57, 95% CI 0.15 to 0.98. However, having a computer with an Internet connection was not associated with weight status. Belonging to the highest quintile (OR 1.8 95% CI 1.2 to 2.8 and second-highest quintile (OR 1.6 95% CI 1.1 to 2.4 of weekly computer use was positively associated with overweight. The proportion of adolescents without a personal cell phone decreased from 12% to 1% across 2000 to 2005. There was a positive linear trend of increasing monthly phone bill with BMI (beta 0.18, 95% CI 0.06 to 0.30, but the association of a cell phone bill with overweight was very weak. Conclusion Time spent using a home computer was associated with an increased risk of overweight. Cell phone use correlated weakly with BMI. Increasing use of information and communication technology may be related to the obesity epidemic among adolescents.

  3. Towards the Epidemiological Modeling of Computer Viruses

    OpenAIRE

    Xiaofan Yang; Lu-Xing Yang

    2012-01-01

    Epidemic dynamics of computer viruses is an emerging discipline aiming to understand the way that computer viruses spread on networks. This paper is intended to establish a series of rational epidemic models of computer viruses. First, a close inspection of some common characteristics shared by all typical computer viruses clearly reveals the flaws of previous models. Then, a generic epidemic model of viruses, which is named as the SLBS model, is proposed. Finally, diverse generalizations of ...

  4. Computational modelling of SCC flow

    DEFF Research Database (Denmark)

    Geiker, Mette Rica; Thrane, Lars Nyholm; Szabo, Peter

    2005-01-01

    To benefit from the full potential of self-compacting concrete (SCC) prediction tools are needed for the form filling of SCC. Such tools should take into account the properties of the concrete, the shape and size of the structural element, the position of rebars, and the casting technique. Exampl...... of computational models for the time dependent flow behavior are given, and advantages and disadvantages of discrete particle and single fluid models are briefly described.......To benefit from the full potential of self-compacting concrete (SCC) prediction tools are needed for the form filling of SCC. Such tools should take into account the properties of the concrete, the shape and size of the structural element, the position of rebars, and the casting technique. Examples...

  5. Computational Chemistry in the Pharmaceutical Industry: From Childhood to Adolescence.

    Science.gov (United States)

    Hillisch, Alexander; Heinrich, Nikolaus; Wild, Hanno

    2015-12-01

    Computational chemistry within the pharmaceutical industry has grown into a field that proactively contributes to many aspects of drug design, including target selection and lead identification and optimization. While methodological advancements have been key to this development, organizational developments have been crucial to our success as well. In particular, the interaction between computational and medicinal chemistry and the integration of computational chemistry into the entire drug discovery process have been invaluable. Over the past ten years we have shaped and developed a highly efficient computational chemistry group for small-molecule drug discovery at Bayer HealthCare that has significantly impacted the clinical development pipeline. In this article we describe the setup and tasks of the computational group and discuss external collaborations. We explain what we have found to be the most valuable and productive methods and discuss future directions for computational chemistry method development. We share this information with the hope of igniting interesting discussions around this topic.

  6. Developmental Cascade Model for Adolescent Substance Use from Infancy to Late Adolescence

    Science.gov (United States)

    Eiden, Rina D.; Lessard, Jared; Colder, Craig R.; Livingston, Jennifer; Casey, Meghan; Leonard, Kenneth E.

    2016-01-01

    A developmental cascade model for adolescent substance use beginning in infancy was examined in a sample of children with alcoholic and nonalcoholic parents. The model examined the role of parents' alcohol diagnoses, depression and antisocial behavior in a cascading process of risk via 3 major hypothesized pathways: first, via parental…

  7. The role of parents and related factors on adolescent computer use

    Directory of Open Access Journals (Sweden)

    Jennifer A. Epstein

    2012-02-01

    Full Text Available Background. Research suggested the importance of parents on their adolescents’ computer activity. Spending too much time on the computer for recreational purposes in particular has been found to be related to areas of public health concern in children/adolescents, including obesity and substance use. Design and Methods. The goal of the research was to determine the association between recreational computer use and potentially linked factors (parental monitoring, social influences to use computers including parents, age of first computer use, self-control, and particular internet activities. Participants (aged 13-17 years and residing in the United States were recruited via the Internet to complete an anonymous survey online using a survey tool. The target sample of 200 participants who completed the survey was achieved. The sample’s average age was 16 and was 63% girls. Results. A set of regressions with recreational computer use as dependent variables were run. Conclusions. Less parental monitoring, younger age at first computer use, listening or downloading music from the internet more frequently, using the internet for educational purposes less frequently, and parent’s use of the computer for pleasure was related to spending a greater percentage of time on non-school computer use. These findings suggest the importance of parental monitoring and parental computer use on their children’s own computer use, and the influence of some internet activities on adolescent computer use. Finally, programs aimed at parents to help them increase the age when their children start using computers and learn how to place limits on recreational computer use are needed.

  8. A twin study of computer anxiety in Turkish adolescents.

    Science.gov (United States)

    Deryakulu, Deniz; Calışkan, Erkan

    2012-04-01

    The present study investigated computer anxiety within a sample of Turkish twins aged 10-18. A total of 185 twin-pairs participated in the study. Of the twins, 64 pairs (34.6 percent) were monozygotic (MZ) and 121 pairs (65.4 percent) were dizygotic (DZ). Of the 121 DZ twins, 54 pairs (44.63 percent) were same-sex twins and 67 pairs (55.37 percent) were opposite-sex twins. Computer anxiety was assessed using Computer Anxiety Rating Scale-Turkish Version (CARS-TV), one of the three main scales of "Measuring Technophobia Instruments" developed by Rosen and Weil. The results of paired t test comparisons showed no significant differences in MZ and same-sex DZ twin-pairs' levels of computer anxiety. On the other hand, a significant difference was found in opposite-sex DZ twin-pairs' level of computer anxiety. Interesting enough, males appeared to be more computer anxious than their female co-twins. In the present study, using Falconer's formula, heritability estimate for computer anxiety was derived from correlations based on MZ and DZ twins' mean scores on CARS-TV. The results showed that 57 percent of the variance in computer anxiety was from genetics and 41.5 percent was from nonshared environmental factors. Shared environmental influence, on the other hand, was very small and negligible. Interpretations of results and potential directions for future research are presented.

  9. Towards the Epidemiological Modeling of Computer Viruses

    Directory of Open Access Journals (Sweden)

    Xiaofan Yang

    2012-01-01

    Full Text Available Epidemic dynamics of computer viruses is an emerging discipline aiming to understand the way that computer viruses spread on networks. This paper is intended to establish a series of rational epidemic models of computer viruses. First, a close inspection of some common characteristics shared by all typical computer viruses clearly reveals the flaws of previous models. Then, a generic epidemic model of viruses, which is named as the SLBS model, is proposed. Finally, diverse generalizations of the SLBS model are suggested. We believe this work opens a door to the full understanding of how computer viruses prevail on the Internet.

  10. Quantum Computation Beyond the Circuit Model

    OpenAIRE

    Jordan, Stephen P.

    2008-01-01

    The quantum circuit model is the most widely used model of quantum computation. It provides both a framework for formulating quantum algorithms and an architecture for the physical construction of quantum computers. However, several other models of quantum computation exist which provide useful alternative frameworks for both discovering new quantum algorithms and devising new physical implementations of quantum computers. In this thesis, I first present necessary background material for a ge...

  11. Adolescent computer use and alcohol use: what are the role of quantity and content of computer use?

    Science.gov (United States)

    Epstein, Jennifer A

    2011-05-01

    The purpose of this study was to examine the relationship between computer use and alcohol use among adolescents. In particular, the goal of the research was to determine the role of lifetime drinking and past month drinking on quantity as measured by amount of time on the computer (for school work and excluding school work) and on content as measured by the frequency of a variety of activities on the internet (e.g., e-mail, searching for information, social networking, listen to/download music). Participants (aged 13-17 years and residing in the United States) were recruited via the internet to complete an anonymous survey online using a popular survey tool (N=270). Their average age was 16 and the sample was predominantly female (63% girls). A series of analyses was conducted with the computer use measures as dependent variables (hours on the computer per week for school work and excluding school work; various internet activities including e-mail, searching for information, social networking, listen to/download music) controlling for gender, age, academic performance and age of first computer use. Based on the results, past month drinkers used the computer more hours per week excluding school work than those who did not. As expected, there were no differences in hours based on alcohol use for computer use for school work. Drinking also had relationships with more frequent social networking and listening to/downloading music. These findings suggest that both quantity and content of computer use were related to adolescent drinking.

  12. Computational modeling of epithelial tissues.

    Science.gov (United States)

    Smallwood, Rod

    2009-01-01

    There is an extensive literature on the computational modeling of epithelial tissues at all levels from subcellular to whole tissue. This review concentrates on behavior at the individual cell to whole tissue level, and particularly on organizational aspects, and provides an indication of where information from other areas, such as the modeling of angiogenesis, is relevant. The skin, and the lining of all of the body cavities (lung, gut, cervix, bladder etc) are epithelial tissues, which in a topological sense are the boundary between inside and outside the body. They are thin sheets of cells (usually of the order of 0.5 mm thick) without extracellular matrix, have a relatively simple structure, and contain few types of cells. They have important barrier, secretory and transport functions, which are essential for the maintenance of life, so homeostasis and wound healing are important aspects of the behavior of epithelial tissues. Carcinomas originate in epithelial tissues.There are essentially two approaches to modeling tissues--to start at the level of the tissue (i.e., a length scale of the order of 1 mm) and develop generalized equations for behavior (a continuum approach); or to start at the level of the cell (i.e., a length scale of the order of 10 µm) and develop tissue behavior as an emergent property of cellular behavior (an individual-based approach). As will be seen, these are not mutually exclusive approaches, and they come in a variety of flavors.

  13. Acculturation and Aggression in Latino Adolescents: Modeling Longitudinal Trajectories from the Latino Acculturation and Health Project

    Science.gov (United States)

    Smokowski, Paul Richard; Rose, Roderick A.; Bacallao, Martica

    2009-01-01

    This study examines how multiple indicators of adolescent and parent acculturation relate to longitudinal trajectories of Latino adolescent aggression. The hierarchical linear modeling analysis is based on a final sample of 256 adolescents paired with one parent. Of the adolescents, 66% were born outside of the United States and the remaining 34%…

  14. Negative Adult Influences and the Protective Effects of Role Models: A Study with Urban Adolescents

    Science.gov (United States)

    Hurd, Noelle M.; Zimmerman, Marc A.; Xue, Yange

    2009-01-01

    We investigated whether role models (individuals adolescents look up to) contributed to the resilience of adolescents who were exposed to negative nonparental adult influences. Our sample included 659 African American, ninth-grade adolescents. We found that adolescents' exposure to negative adult behavior was associated with increased…

  15. Computeen: A Randomized Trial of a Preventive Computer and Psychosocial Skills Curriculum for At-Risk Adolescents

    Science.gov (United States)

    Lang, Jason M.; Waterman, Jill; Baker, Bruce L.

    2009-01-01

    Computeen, a preventive technology and psychosocial skills development program for at-risk adolescents, was designed to improve computer skills, self-esteem, and school attitudes, and reduce behavior problems, by combining elements of community-based and empirically supported prevention programs. Fifty-five mostly Latino adolescents from 12 to 16…

  16. Prevalence of headache in adolescents and association with use of computer and videogames.

    Science.gov (United States)

    Xavier, Michelle Katherine Andrade; Pitangui, Ana Carolina Rodarti; Silva, Georgia Rodrigues Reis; Oliveira, Valéria Mayaly Alves de; Beltrão, Natália Barros; Araújo, Rodrigo Cappato de

    2015-11-01

    The aim of this study was to determine the prevalence of headache in adolescents and its association with excessive use of electronic devices and games. The sample comprised 954 adolescents of both sexes (14 to 19 years) who answered a questionnaire about use of computers and electronic games, presence of headache and physical activity. The binary and multinomial logistic regression, with significance level of 5% was used for inferential analysis. The prevalence of headache was 80.6%. The excessive use of electronics devices proved to be a risk factor (OR = 1.21) for headache. Subjects aged between 14 and 16 years were less likely to report headache (OR = 0.64). Regarding classification, 17.9% of adolescents had tension-type headache, 19.3% had migraine and 43.4% other types of headache. The adolescents aged form 14 to 16 years had lower chance (OR ≤ 0.68) to report the tension-type headache and other types of headache. The excessive use of digital equipment, electronic games and attending the third year of high school proved to be risk factors for migraine-type development (OR ≥ 1.84). There was a high prevalence of headache in adolescents and high-time use of electronic devices. We observed an association between excessive use of electronic devices and the presence of headache, and this habit is considered a risk factor, especially for the development of migraine-type.

  17. Computational modeling of membrane proteins.

    Science.gov (United States)

    Koehler Leman, Julia; Ulmschneider, Martin B; Gray, Jeffrey J

    2015-01-01

    The determination of membrane protein (MP) structures has always trailed that of soluble proteins due to difficulties in their overexpression, reconstitution into membrane mimetics, and subsequent structure determination. The percentage of MP structures in the protein databank (PDB) has been at a constant 1-2% for the last decade. In contrast, over half of all drugs target MPs, only highlighting how little we understand about drug-specific effects in the human body. To reduce this gap, researchers have attempted to predict structural features of MPs even before the first structure was experimentally elucidated. In this review, we present current computational methods to predict MP structure, starting with secondary structure prediction, prediction of trans-membrane spans, and topology. Even though these methods generate reliable predictions, challenges such as predicting kinks or precise beginnings and ends of secondary structure elements are still waiting to be addressed. We describe recent developments in the prediction of 3D structures of both α-helical MPs as well as β-barrels using comparative modeling techniques, de novo methods, and molecular dynamics (MD) simulations. The increase of MP structures has (1) facilitated comparative modeling due to availability of more and better templates, and (2) improved the statistics for knowledge-based scoring functions. Moreover, de novo methods have benefited from the use of correlated mutations as restraints. Finally, we outline current advances that will likely shape the field in the forthcoming decade.

  18. Cupola Furnace Computer Process Model

    Energy Technology Data Exchange (ETDEWEB)

    Seymour Katz

    2004-12-31

    The cupola furnace generates more than 50% of the liquid iron used to produce the 9+ million tons of castings annually. The cupola converts iron and steel into cast iron. The main advantages of the cupola furnace are lower energy costs than those of competing furnaces (electric) and the ability to melt less expensive metallic scrap than the competing furnaces. However the chemical and physical processes that take place in the cupola furnace are highly complex making it difficult to operate the furnace in optimal fashion. The results are low energy efficiency and poor recovery of important and expensive alloy elements due to oxidation. Between 1990 and 2004 under the auspices of the Department of Energy, the American Foundry Society and General Motors Corp. a computer simulation of the cupola furnace was developed that accurately describes the complex behavior of the furnace. When provided with the furnace input conditions the model provides accurate values of the output conditions in a matter of seconds. It also provides key diagnostics. Using clues from the diagnostics a trained specialist can infer changes in the operation that will move the system toward higher efficiency. Repeating the process in an iterative fashion leads to near optimum operating conditions with just a few iterations. More advanced uses of the program have been examined. The program is currently being combined with an ''Expert System'' to permit optimization in real time. The program has been combined with ''neural network'' programs to affect very easy scanning of a wide range of furnace operation. Rudimentary efforts were successfully made to operate the furnace using a computer. References to these more advanced systems will be found in the ''Cupola Handbook''. Chapter 27, American Foundry Society, Des Plaines, IL (1999).

  19. Computeen: a randomized trial of a preventive computer and psychosocial skills curriculum for at-risk adolescents.

    Science.gov (United States)

    Lang, Jason M; Waterman, Jill; Baker, Bruce L

    2009-09-01

    Computeen, a preventive technology and psychosocial skills development program for at-risk adolescents, was designed to improve computer skills, self-esteem, and school attitudes, and reduce behavior problems, by combining elements of community-based and empirically supported prevention programs. Fifty-five mostly Latino adolescents from 12 to 16 years old who were living in affordable housing communities participated in this randomized wait-list control study. Results showed considerable improvements in computer self-efficacy, decreases in internalizing behavior problems, and excellent attendance and consumer satisfaction. Self-esteem and school motivation results were mixed. Computer self-efficacy mediated the relationship between improved computer skills and self-esteem. Younger adolescents showed greater improvement than did older adolescents. EDITORS' STRATEGIC IMPLICATIONS: Although there are limitations to this study's sample size and scope, Computeen appears promising as a developmentally appropriate, strengths-based prevention program.

  20. Computational biomechanics for medicine imaging, modeling and computing

    CERN Document Server

    Doyle, Barry; Wittek, Adam; Nielsen, Poul; Miller, Karol

    2016-01-01

    The Computational Biomechanics for Medicine titles provide an opportunity for specialists in computational biomechanics to present their latest methodologies and advancements. This volume comprises eighteen of the newest approaches and applications of computational biomechanics, from researchers in Australia, New Zealand, USA, UK, Switzerland, Scotland, France and Russia. Some of the interesting topics discussed are: tailored computational models; traumatic brain injury; soft-tissue mechanics; medical image analysis; and clinically-relevant simulations. One of the greatest challenges facing the computational engineering community is to extend the success of computational mechanics to fields outside traditional engineering, in particular to biology, the biomedical sciences, and medicine. We hope the research presented within this book series will contribute to overcoming this grand challenge.

  1. Disciplines, models, and computers: the path to computational quantum chemistry.

    Science.gov (United States)

    Lenhard, Johannes

    2014-12-01

    Many disciplines and scientific fields have undergone a computational turn in the past several decades. This paper analyzes this sort of turn by investigating the case of computational quantum chemistry. The main claim is that the transformation from quantum to computational quantum chemistry involved changes in three dimensions. First, on the side of instrumentation, small computers and a networked infrastructure took over the lead from centralized mainframe architecture. Second, a new conception of computational modeling became feasible and assumed a crucial role. And third, the field of computa- tional quantum chemistry became organized in a market-like fashion and this market is much bigger than the number of quantum theory experts. These claims will be substantiated by an investigation of the so-called density functional theory (DFT), the arguably pivotal theory in the turn to computational quantum chemistry around 1990.

  2. Business model elements impacting cloud computing adoption

    DEFF Research Database (Denmark)

    Bogataj, Kristina; Pucihar, Andreja; Sudzina, Frantisek

    The paper presents a proposed research framework for identification of business model elements impacting Cloud Computing Adoption. We provide a definition of main Cloud Computing characteristics, discuss previous findings on factors impacting Cloud Computing Adoption, and investigate technology a...... blocks are investigated: Product Innovation, Infrastructure management, Customer relationship, Financial Aspects.......The paper presents a proposed research framework for identification of business model elements impacting Cloud Computing Adoption. We provide a definition of main Cloud Computing characteristics, discuss previous findings on factors impacting Cloud Computing Adoption, and investigate technology...

  3. Computational Modelling in Cancer: Methods and Applications

    Directory of Open Access Journals (Sweden)

    Konstantina Kourou

    2015-01-01

    Full Text Available Computational modelling of diseases is an emerging field, proven valuable for the diagnosis, prognosis and treatment of the disease. Cancer is one of the diseases where computational modelling provides enormous advancements, allowing the medical professionals to perform in silico experiments and gain insights prior to any in vivo procedure. In this paper, we review the most recent computational models that have been proposed for cancer. Well known databases used for computational modelling experiments, as well as, the various markup language representations are discussed. In addition, recent state of the art research studies related to tumour growth and angiogenesis modelling are presented.

  4. Prevalence of musculoskeletal pain in adolescents and association with computer and videogame use

    OpenAIRE

    2016-01-01

    Abstract Objective: This study investigated the presence of musculoskeletal symptoms in high school adolescents from public schools and its association with electronic device use. Methods: The sample consisted of 961 boys and girls aged 14–19 years who answered a questionnaire regarding the use of computers and electronic games, and questions about pain symptoms and physical activity. Furthermore, anthropometric assessments of all volunteers were performed. The chi-squared test and a ...

  5. Computational Models for Nonlinear Aeroelastic Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Clear Science Corp. and Duke University propose to develop and demonstrate new and efficient computational methods of modeling nonlinear aeroelastic systems. The...

  6. Adolescent emotional maturation through divergent models of brain organization

    Directory of Open Access Journals (Sweden)

    Jose Víctor Orón Semper

    2016-08-01

    Full Text Available In this article we introduce the hypothesis that neuropsychological adolescent maturation, and in particular emotional management, may have opposing explanations depending on the interpretation of the assumed brain architecture, that is, whether a componential computational account (CCA or a dynamic systems perspective (DSP is used. According to CCA, cognitive functions are associated with the action of restricted brain regions, and this association is temporally stable; by contrast, DSP argues that cognitive functions are better explained by interactions between several brain areas, whose engagement in specific functions is temporal and context-dependent and based on neural reuse. We outline the main neurobiological facts about adolescent maturation, focusing on the neuroanatomical and neurofunctional processes associated with adolescence. We then explain the importance of emotional management in adolescent maturation. We explain the interplay between emotion and cognition under the scope of CCA and DSP, both at neural and behavioral levels. Finally, we justify why, according to CCA, emotional management is understood as regulation, specifically because the cognitive aspects of the brain are in charge of regulating emotion-related modules. However, the key word in DSP is integration, since neural information from different brain areas is integrated from the beginning of the process. Consequently, although the terms should not be conceptually confused, there is no cognition without emotion, and vice versa. Thus, emotional integration is not an independent process that just happens to the subject, but a crucial part of personal growth. Considering the importance of neuropsychological research in the development of educational and legal policies concerning adolescents, we intend to expose that the holistic view of adolescents is dependent on whether one holds the implicit or explicit interpretation of brain functioning.

  7. Model of computation for Fourier optical processors

    Science.gov (United States)

    Naughton, Thomas J.

    2000-05-01

    We present a novel and simple theoretical model of computation that captures what we believe are the most important characteristics of an optical Fourier transform processor. We use this abstract model to reason about the computational properties of the physical systems it describes. We define a grammar for our model's instruction language, and use it to write algorithms for well-known filtering and correlation techniques. We also suggest suitable computational complexity measures that could be used to analyze any coherent optical information processing technique, described with the language, for efficiency. Our choice of instruction language allows us to argue that algorithms describable with this model should have optical implementations that do not require a digital electronic computer to act as a master unit. Through simulation of a well known model of computation from computer theory we investigate the general-purpose capabilities of analog optical processors.

  8. Regional brain activation associated with addiction of computer games in adolescents

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Y. H.; Shin, O. J.; Ko, Y. W.; Kim, H. J.; Yun, M. J.; Lee, J. D. [College of Medicine, Yonsei Univ., Seoul (Korea, Republic of)

    2001-07-01

    Excessive computer game (CG) playing may cause not only behavioral addiction, but also potential negative effects on developing brain. It is necessary to reveal how brain is affected by excessive use of CG playing and behavioral addiction of it. By using PET, we address the issue seeking to identifying patterns of regional brain activation associated with behavioral addiction and excessive use of CG playing by adolescents. 6 normal control and 8 adolescents who were met by the criteria of behavioral addiction on the survey as addiction groups with an addiction of CG playing were participated. Initial screening survey which is the adapted version of DSM-IV for pathologic gambling was done. PET were performed twice in each participants both during resting state and after 20 min playing of CG. Psychological test including Youth Self Report (YSR), memory and attention test and vocabulary item from KWAIS were performed. Scores of the vocabulary item from KWAIS and social competence from YSR were significantly lower in the addiction group. On PET, addiction group showed higher resting metabolism on inferior frontal, premotor, prefrontal and superior temporal area. Adolescents with addiction of CG revealed different patterns of regional brain activation comparing to control groups. These suggest behavioral addiction and excessive use of CG may result in functional alteration of developing brain in adolescents.

  9. A computational model for feature binding

    Institute of Scientific and Technical Information of China (English)

    SHI ZhiWei; SHI ZhongZhi; LIU Xi; SHI ZhiPing

    2008-01-01

    The "Binding Problem" is an important problem across many disciplines, including psychology, neuroscience, computational modeling, and even philosophy. In this work, we proposed a novel computational model, Bayesian Linking Field Model, for feature binding in visual perception, by combining the idea of noisy neuron model, Bayesian method, Linking Field Network and competitive mechanism.Simulation Experiments demonstrated that our model perfectly fulfilled the task of feature binding in visual perception and provided us some enlightening idea for future research.

  10. A computational model for feature binding

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The "Binding Problem" is an important problem across many disciplines, including psychology, neuroscience, computational modeling, and even philosophy. In this work, we proposed a novel computational model, Bayesian Linking Field Model, for feature binding in visual perception, by combining the idea of noisy neuron model, Bayesian method, Linking Field Network and competitive mechanism. Simulation Experiments demonstrated that our model perfectly fulfilled the task of feature binding in visual perception and provided us some enlightening idea for future research.

  11. Computational nanophotonics modeling and applications

    CERN Document Server

    Musa, Sarhan M

    2013-01-01

    This reference offers tools for engineers, scientists, biologists, and others working with the computational techniques of nanophotonics. It introduces the key concepts of computational methods in a manner that is easily digestible for newcomers to the field. The book also examines future applications of nanophotonics in the technical industry and covers new developments and interdisciplinary research in engineering, science, and medicine. It provides an overview of the key computational nanophotonics and describes the technologies with an emphasis on how they work and their key benefits.

  12. Violence in Young Adolescents' Relationships: A Path Model

    Science.gov (United States)

    Josephson, Wendy L.; Proulx, Jocelyn B.

    2008-01-01

    A structural equation model based on social cognitive theory was used to predict relationship violence from young adolescents' knowledge, self-efficacy, attitudes, and alternative conflict strategies (n = 143 male and 147 female grade 7-9 students). A direct causal effect was supported for violence-tolerant attitudes and psychologically aggressive…

  13. Two Classes of Models of Granular Computing

    Institute of Scientific and Technical Information of China (English)

    Daowu Pei

    2006-01-01

    This paper reviews a class of important models of granular computing which are induced by equivalence relations, or by general binary relations, or by neighborhood systems, and propose a class of models of granular computing which are induced by coverings of the given universe.

  14. Large Scale Computations in Air Pollution Modelling

    DEFF Research Database (Denmark)

    Zlatev, Z.; Brandt, J.; Builtjes, P. J. H.

    Proceedings of the NATO Advanced Research Workshop on Large Scale Computations in Air Pollution Modelling, Sofia, Bulgaria, 6-10 July 1998......Proceedings of the NATO Advanced Research Workshop on Large Scale Computations in Air Pollution Modelling, Sofia, Bulgaria, 6-10 July 1998...

  15. Computer Aided Continuous Time Stochastic Process Modelling

    DEFF Research Database (Denmark)

    Kristensen, N.R.; Madsen, Henrik; Jørgensen, Sten Bay

    2001-01-01

    A grey-box approach to process modelling that combines deterministic and stochastic modelling is advocated for identification of models for model-based control of batch and semi-batch processes. A computer-aided tool designed for supporting decision-making within the corresponding modelling cycle...

  16. Element-Based Computational Model

    Directory of Open Access Journals (Sweden)

    Conrad Mueller

    2012-02-01

    Full Text Available A variation on the data-flow model is proposed to use for developing parallel architectures. While the model is a data driven model it has significant differences to the data-flow model. The proposed model has an evaluation cycleof processing elements (encapsulated data that is similar to the instruction cycle of the von Neumann model. The elements contain the information required to process them. The model is inherently parallel. An emulation of the model has been implemented. The objective of this paper is to motivate support for taking the research further. Using matrix multiplication as a case study, the element/data-flow based model is compared with the instruction-based model. This is done using complexity analysis followed by empirical testing to verify this analysis. The positive results are given as motivation for the research to be taken to the next stage - that is, implementing the model using FPGAs.

  17. The Effects of Internet Use, Cell Phones and Computer Games on Mental Health of Children and Adolescents

    Directory of Open Access Journals (Sweden)

    Meral Kelleci

    2008-06-01

    Full Text Available The use of digital technology, including computers, cell phones, computer games, and so on, most recently, on-the-go for recreational purposes, has increased among our youth over the past 15 years. Children and adolescent between the ages of 8 to 18 years spend an average of 5-6 hours per day using information and communication technologies. It is a useful progress because of the increase of internet usage which is unlimited, uncontrolled and uninhibited and easiness which arrival all sorts of to informations or persons but this state can cause to some important negative results too. The computer games, the internet explores is gradually estrange from social life the children and adolescent. In this paper, has been mentioned to negative effect of internet usage, computer games on mental health of children and adolescents. [TAF Prev Med Bull 2008; 7(3.000: 253-256

  18. Focus on Methodology: Beyond paper and pencil: Conducting computer-assisted data collection with adolescents in group settings.

    Science.gov (United States)

    Raffaelli, Marcela; Armstrong, Jessica; Tran, Steve P; Griffith, Aisha N; Walker, Kathrin; Gutierrez, Vanessa

    2016-06-01

    Computer-assisted data collection offers advantages over traditional paper and pencil measures; however, little guidance is available regarding the logistics of conducting computer-assisted data collection with adolescents in group settings. To address this gap, we draw on our experiences conducting a multi-site longitudinal study of adolescent development. Structured questionnaires programmed on laptop computers using Audio Computer Assisted Self-Interviewing (ACASI) were administered to groups of adolescents in community-based and afterschool programs. Although implementing ACASI required additional work before entering the field, we benefited from reduced data processing time, high data quality, and high levels of youth motivation. Preliminary findings from an ethnically diverse sample of 265 youth indicate favorable perceptions of using ACASI. Using our experiences as a case study, we provide recommendations on selecting an appropriate data collection device (including hardware and software), preparing and testing the ACASI, conducting data collection in the field, and managing data.

  19. ADVANCED COMPUTATIONAL METHODS IN DOSE MODELING: APPLICATION OF COMPUTATIONAL BIOPHYSICAL TRANSPORT, COMPUTATIONAL CHEMISTRY, AND COMPUTATIONAL BIOLOGY

    Science.gov (United States)

    Computational toxicology (CompTox) leverages the significant gains in computing power and computational techniques (e.g., numerical approaches, structure-activity relationships, bioinformatics) realized over the last few years, thereby reducing costs and increasing efficiency i...

  20. Skills-Based, Interactive Computer Interventions to Prevent HIV Infection Among African-American and Hispanic Adolescents.

    Science.gov (United States)

    Schinke, Steven P; Orlandi, Mario A

    1990-01-01

    The spread of the acquired immunodeficiency virus (AIDS) virus, human immunodeficiency virus (HIV) infection, is increasingly evident. Despite the attention that HIV infection has received, few effective prevention strategies have been developed. The present paper reviews the epidemiology of AIDS among African-American and Hispanic adolescents. From epidemiological data, the authors argue for preventive approaches to reduce the risks of HIV transmission among African-American and Hispanic adolescents. Emphasizing culturally sensitive prevention strategies, the authors describe an intervention for these adolescents that combines skills-based and interactive computer approaches.

  1. Introducing Seismic Tomography with Computational Modeling

    Science.gov (United States)

    Neves, R.; Neves, M. L.; Teodoro, V.

    2011-12-01

    Learning seismic tomography principles and techniques involves advanced physical and computational knowledge. In depth learning of such computational skills is a difficult cognitive process that requires a strong background in physics, mathematics and computer programming. The corresponding learning environments and pedagogic methodologies should then involve sets of computational modelling activities with computer software systems which allow students the possibility to improve their mathematical or programming knowledge and simultaneously focus on the learning of seismic wave propagation and inverse theory. To reduce the level of cognitive opacity associated with mathematical or programming knowledge, several computer modelling systems have already been developed (Neves & Teodoro, 2010). Among such systems, Modellus is particularly well suited to achieve this goal because it is a domain general environment for explorative and expressive modelling with the following main advantages: 1) an easy and intuitive creation of mathematical models using just standard mathematical notation; 2) the simultaneous exploration of images, tables, graphs and object animations; 3) the attribution of mathematical properties expressed in the models to animated objects; and finally 4) the computation and display of mathematical quantities obtained from the analysis of images and graphs. Here we describe virtual simulations and educational exercises which enable students an easy grasp of the fundamental of seismic tomography. The simulations make the lecture more interactive and allow students the possibility to overcome their lack of advanced mathematical or programming knowledge and focus on the learning of seismological concepts and processes taking advantage of basic scientific computation methods and tools.

  2. 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...

  3. Visual and Computational Modelling of Minority Games

    OpenAIRE

    Robertas Damaševičius; Darius Ašeriškis

    2017-01-01

    The paper analyses the Minority Game and focuses on analysis and computational modelling of several variants (variable payoff, coalition-based and ternary voting) of Minority Game using UAREI (User-Action-Rule-Entities-Interface) model. UAREI is a model for formal specification of software gamification, and the UAREI visual modelling language is a language used for graphical representation of game mechanics. The URAEI model also provides the embedded executable modelling framework to evaluate...

  4. Producing Irony in Adolescence: A Comparison Between Face-to-Face and Computer-Mediated Communication

    Directory of Open Access Journals (Sweden)

    Aguert Marc

    2016-12-01

    Full Text Available The literature suggests that irony production expands in the developmental period of adolescence. We aimed to test this hypothesis by investigating two channels: face-to-face and computer-mediated communication (CMC. Corpora were collected by asking seventh and 11th graders to freely discuss some general topics (e.g., music, either face-to-face or on online forums. Results showed that 6.2% of the 11th graders’ productions were ironic utterances, compared with just 2.5% of the seventh graders’ productions, confirming the major development of irony production in adolescence. Results also showed that adolescents produced more ironic utterances in CMC than face-to-face. The analysis suggested that irony use is a strategy for increasing in-group solidarity and compensating for the distance intrinsic to CMC, as it was mostly inclusive and well-marked on forums. The present study also confirmed previous studies showing that irony is compatible with CMC.

  5. Association of sleep quality with watching TV, computer games and caffeine intake in adolescents of Minoodar district, Qazvin

    Directory of Open Access Journals (Sweden)

    A. Avani

    2015-12-01

    Full Text Available Background: Insufficient sleep or poor sleep quality affect learning, memory and performance and cause behavioral disorders. Watching television (TV, using computer and internet, playing computer games, and caffeine intake are of factors affecting sleep quality. Objective: The aim of this study was to determine the association of sleep quality with watching TV, computer games and caffeine intake in adolescents of Minoodar district, Qazvin41T. Methods: This cross sectional study was conducted in 319 adolescents (10 to 18 years old that were selected by multistage cluster random sampling method during 2010-2011. Demographic data and data on duration of playing computer games and watching TV were collected. Food frequency questionnaire and BEARS questionnaire were completed. Data were analyzed using Chi-square test, logistic regression analysis and ANOVA. Findings:Mean age was15±2.43 years41T. Of 319 adolescents, 162 (50.8% were female41T. The duration of watching TV or video41T was not significantly different41T between boys and girls. The duration of playing computer or video games41T was statistically different41T between boys and girls. There was no correlation between sleep quality and duration of watching TV or videos in a day, duration of playing computer or video games in a day, and caffeine intake in adolescents. Conclusions: With regards to the results, it seems that there is no association between sleep quality and watching TV, playing computer games and caffeine intake.

  6. 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…

  7. The Self-Esteem, Perceived Social Support and Hopelessness in Adolescents: The Structural Equation Modeling

    Science.gov (United States)

    Savi Cakar, Firdevs; Karatas, Zeynep

    2012-01-01

    In this study, a developed model to explain a causal relationship between adolescent's self-esteem, perceived social support and hopelessness is tested. The purpose of the study is to explore the relationship between self-esteem, perceived social support and hopelessness in adolescents. A total of 257 adolescents, including 143 female and 114…

  8. Computer-Aided Modelling Methods and Tools

    DEFF Research Database (Denmark)

    Cameron, Ian; Gani, Rafiqul

    2011-01-01

    The development of models for a range of applications requires methods and tools. In many cases a reference model is required that allows the generation of application specific models that are fit for purpose. There are a range of computer aided modelling tools available that help to define...... a taxonomy of aspects around conservation, constraints and constitutive relations. Aspects of the ICAS-MoT toolbox are given to illustrate the functionality of a computer aided modelling tool, which incorporates an interface to MS Excel....

  9. Notions of similarity for computational biology models

    KAUST Repository

    Waltemath, Dagmar

    2016-03-21

    Computational models used in biology are rapidly increasing in complexity, size, and numbers. To build such large models, researchers need to rely on software tools for model retrieval, model combination, and version control. These tools need to be able to quantify the differences and similarities between computational models. However, depending on the specific application, the notion of similarity may greatly vary. A general notion of model similarity, applicable to various types of models, is still missing. Here, we introduce a general notion of quantitative model similarities, survey the use of existing model comparison methods in model building and management, and discuss potential applications of model comparison. To frame model comparison as a general problem, we describe a theoretical approach to defining and computing similarities based on different model aspects. Potentially relevant aspects of a model comprise its references to biological entities, network structure, mathematical equations and parameters, and dynamic behaviour. Future similarity measures could combine these model aspects in flexible, problem-specific ways in order to mimic users\\' intuition about model similarity, and to support complex model searches in databases.

  10. Using an age-specific nursing model to tailor care to the adolescent surgical patient.

    Science.gov (United States)

    Monahan, Janean Carter

    2014-06-01

    A surgical experience can be stressful for any patient. When the patient is an adolescent, however, the surgical experience can create significant stress, which is related to normal adolescent development. Perioperative nursing care should address what adolescent patients perceive as stressful and should provide a safe environment so that a successful surgical outcome can be achieved. To accomplish this, a nursing model specific to perioperative nursing practice should be developed to guide nurses when providing care to adolescents. The Adolescent Perioperative System Stability Model based on the Neuman Systems Model provides a framework for defining scope of practice and organizing nursing care that is appropriate for the adolescent during a surgical experience. In addition to guiding nursing practice, this model provides direction and guidance for future studies of adolescents in the perioperative setting.

  11. Computational Models for Nonlinear Aeroelastic Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Clear Science Corp. and Duke University propose to develop and demonstrate a new and efficient computational method of modeling nonlinear aeroelastic systems. The...

  12. A new epidemic model of computer viruses

    Science.gov (United States)

    Yang, Lu-Xing; Yang, Xiaofan

    2014-06-01

    This paper addresses the epidemiological modeling of computer viruses. By incorporating the effect of removable storage media, considering the possibility of connecting infected computers to the Internet, and removing the conservative restriction on the total number of computers connected to the Internet, a new epidemic model is proposed. Unlike most previous models, the proposed model has no virus-free equilibrium and has a unique endemic equilibrium. With the aid of the theory of asymptotically autonomous systems as well as the generalized Poincare-Bendixson theorem, the endemic equilibrium is shown to be globally asymptotically stable. By analyzing the influence of different system parameters on the steady number of infected computers, a collection of policies is recommended to prohibit the virus prevalence.

  13. Computational models for analyzing lipoprotein profiles

    NARCIS (Netherlands)

    Graaf, A.A. de; Schalkwijk, D.B. van

    2011-01-01

    At present, several measurement technologies are available for generating highly detailed concentration-size profiles of lipoproteins, offering increased diagnostic potential. Computational models are useful in aiding the interpretation of these complex datasets and making the data more accessible f

  14. Informing mechanistic toxicology with computational molecular models.

    Science.gov (United States)

    Goldsmith, Michael R; Peterson, Shane D; Chang, Daniel T; Transue, Thomas R; Tornero-Velez, Rogelio; Tan, Yu-Mei; Dary, Curtis C

    2012-01-01

    Computational molecular models of chemicals interacting with biomolecular targets provides toxicologists a valuable, affordable, and sustainable source of in silico molecular level information that augments, enriches, and complements in vitro and in vivo efforts. From a molecular biophysical ansatz, we describe how 3D molecular modeling methods used to numerically evaluate the classical pair-wise potential at the chemical/biological interface can inform mechanism of action and the dose-response paradigm of modern toxicology. With an emphasis on molecular docking, 3D-QSAR and pharmacophore/toxicophore approaches, we demonstrate how these methods can be integrated with chemoinformatic and toxicogenomic efforts into a tiered computational toxicology workflow. We describe generalized protocols in which 3D computational molecular modeling is used to enhance our ability to predict and model the most relevant toxicokinetic, metabolic, and molecular toxicological endpoints, thereby accelerating the computational toxicology-driven basis of modern risk assessment while providing a starting point for rational sustainable molecular design.

  15. Computer Model Locates Environmental Hazards

    Science.gov (United States)

    2008-01-01

    Catherine Huybrechts Burton founded San Francisco-based Endpoint Environmental (2E) LLC in 2005 while she was a student intern and project manager at Ames Research Center with NASA's DEVELOP program. The 2E team created the Tire Identification from Reflectance model, which algorithmically processes satellite images using turnkey technology to retain only the darkest parts of an image. This model allows 2E to locate piles of rubber tires, which often are stockpiled illegally and cause hazardous environmental conditions and fires.

  16. Computer Modeling of Ceramic Boride Composites

    Science.gov (United States)

    2014-11-01

    AFRL-AFOSR-UK-TR-2015-0016 Computer Modeling of Ceramic Boride Composites Dr. Valeriy V. Kartuzov SCIENCE AND TECHNOLOGY...Research Laboratory Air Force Office of Scientific Research European Office of Aerospace Research and Development Unit 4515, APO AE 09421-4515...4. TITLE AND SUBTITLE Computer Modeling of Ceramic Boride Composites  5a. CONTRACT NUMBER STCU P-510 5b. GRANT NUMBER STCU 11-8003 5c

  17. Association of sleep quality with watching TV, computer games and caffeine intake in adolescents of Minoodar district, Qazvin

    OpenAIRE

    A. Avani; Sh. Jalilolghadr; A. Barikani; A Javadi; S. Shabbidar; Javadi, M

    2015-01-01

    Background: Insufficient sleep or poor sleep quality affect learning, memory and performance and cause behavioral disorders. Watching television (TV), using computer and internet, playing computer games, and caffeine intake are of factors affecting sleep quality. Objective: The aim of this study was to determine the association of sleep quality with watching TV, computer games and caffeine intake in adolescents of Minoodar district, Qazvin41T. Methods: This cross sectional study was con...

  18. Parallel computing in atmospheric chemistry models

    Energy Technology Data Exchange (ETDEWEB)

    Rotman, D. [Lawrence Livermore National Lab., CA (United States). Atmospheric Sciences Div.

    1996-02-01

    Studies of atmospheric chemistry are of high scientific interest, involve computations that are complex and intense, and require enormous amounts of I/O. Current supercomputer computational capabilities are limiting the studies of stratospheric and tropospheric chemistry and will certainly not be able to handle the upcoming coupled chemistry/climate models. To enable such calculations, the authors have developed a computing framework that allows computations on a wide range of computational platforms, including massively parallel machines. Because of the fast paced changes in this field, the modeling framework and scientific modules have been developed to be highly portable and efficient. Here, the authors present the important features of the framework and focus on the atmospheric chemistry module, named IMPACT, and its capabilities. Applications of IMPACT to aircraft studies will be presented.

  19. A Computational Framework for Realistic Retina Modeling.

    Science.gov (United States)

    Martínez-Cañada, Pablo; Morillas, Christian; Pino, Begoña; Ros, Eduardo; Pelayo, Francisco

    2016-11-01

    Computational simulations of the retina have led to valuable insights about the biophysics of its neuronal activity and processing principles. A great number of retina models have been proposed to reproduce the behavioral diversity of the different visual processing pathways. While many of these models share common computational stages, previous efforts have been more focused on fitting specific retina functions rather than generalizing them beyond a particular model. Here, we define a set of computational retinal microcircuits that can be used as basic building blocks for the modeling of different retina mechanisms. To validate the hypothesis that similar processing structures may be repeatedly found in different retina functions, we implemented a series of retina models simply by combining these computational retinal microcircuits. Accuracy of the retina models for capturing neural behavior was assessed by fitting published electrophysiological recordings that characterize some of the best-known phenomena observed in the retina: adaptation to the mean light intensity and temporal contrast, and differential motion sensitivity. The retinal microcircuits are part of a new software platform for efficient computational retina modeling from single-cell to large-scale levels. It includes an interface with spiking neural networks that allows simulation of the spiking response of ganglion cells and integration with models of higher visual areas.

  20. Proceedings Fifth Workshop on Developments in Computational Models--Computational Models From Nature

    CERN Document Server

    Cooper, S Barry; 10.4204/EPTCS.9

    2009-01-01

    The special theme of DCM 2009, co-located with ICALP 2009, concerned Computational Models From Nature, with a particular emphasis on computational models derived from physics and biology. The intention was to bring together different approaches - in a community with a strong foundational background as proffered by the ICALP attendees - to create inspirational cross-boundary exchanges, and to lead to innovative further research. Specifically DCM 2009 sought contributions in quantum computation and information, probabilistic models, chemical, biological and bio-inspired ones, including spatial models, growth models and models of self-assembly. Contributions putting to the test logical or algorithmic aspects of computing (e.g., continuous computing with dynamical systems, or solid state computing models) were also very much welcomed.

  1. Computer Modeling of Direct Metal Laser Sintering

    Science.gov (United States)

    Cross, Matthew

    2014-01-01

    A computational approach to modeling direct metal laser sintering (DMLS) additive manufacturing process is presented. The primary application of the model is for determining the temperature history of parts fabricated using DMLS to evaluate residual stresses found in finished pieces and to assess manufacturing process strategies to reduce part slumping. The model utilizes MSC SINDA as a heat transfer solver with imbedded FORTRAN computer code to direct laser motion, apply laser heating as a boundary condition, and simulate the addition of metal powder layers during part fabrication. Model results are compared to available data collected during in situ DMLS part manufacture.

  2. Visual and Computational Modelling of Minority Games

    Directory of Open Access Journals (Sweden)

    Robertas Damaševičius

    2017-02-01

    Full Text Available The paper analyses the Minority Game and focuses on analysis and computational modelling of several variants (variable payoff, coalition-based and ternary voting of Minority Game using UAREI (User-Action-Rule-Entities-Interface model. UAREI is a model for formal specification of software gamification, and the UAREI visual modelling language is a language used for graphical representation of game mechanics. The URAEI model also provides the embedded executable modelling framework to evaluate how the rules of the game will work for the players in practice. We demonstrate flexibility of UAREI model for modelling different variants of Minority Game rules for game design.

  3. Computational modeling of concrete flow

    DEFF Research Database (Denmark)

    Roussel, Nicolas; Geiker, Mette Rica; Dufour, Frederic

    2007-01-01

    particle flow, and numerical techniques allowing the modeling of particles suspended in a fluid. The general concept behind each family of techniques is described. Pros and cons for each technique are given along with examples and references to applications to fresh cementitious materials....

  4. Computational Modeling of Culture's Consequences

    NARCIS (Netherlands)

    Hofstede, G.J.; Jonker, C.M.; Verwaart, T.

    2010-01-01

    This paper presents an approach to formalize the influence of culture on the decision functions of agents in social simulations. The key components are (a) a definition of the domain of study in the form of a decision model, (b) knowledge acquisition based on a dimensional theory of culture, resulti

  5. Computational aspects of premixing modelling

    Energy Technology Data Exchange (ETDEWEB)

    Fletcher, D.F. [Sydney Univ., NSW (Australia). Dept. of Chemical Engineering; Witt, P.J.

    1998-01-01

    In the steam explosion research field there is currently considerable effort being devoted to the modelling of premixing. Practically all models are based on the multiphase flow equations which treat the mixture as an interpenetrating continuum. Solution of these equations is non-trivial and a wide range of solution procedures are in use. This paper addresses some numerical aspects of this problem. In particular, we examine the effect of the differencing scheme for the convective terms and show that use of hybrid differencing can cause qualitatively wrong solutions in some situations. Calculations are performed for the Oxford tests, the BNL tests, a MAGICO test and to investigate various sensitivities of the solution. In addition, we show that use of a staggered grid can result in a significant error which leads to poor predictions of `melt` front motion. A correction is given which leads to excellent convergence to the analytic solution. Finally, we discuss the issues facing premixing model developers and highlight the fact that model validation is hampered more by the complexity of the process than by numerical issues. (author)

  6. Organ doses for reference pediatric and adolescent patients undergoing computed tomography estimated by Monte Carlo simulation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Choonsik; Kim, Kwang Pyo; Long, Daniel J.; Bolch, Wesley E. [Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institute of Health, Bethesda, Maryland 20852 (United States); Department of Nuclear Engineering, Kyung Hee University, Gyeonggi-do, 446906 (Korea, Republic of); J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida 32611 (United States)

    2012-04-15

    Purpose: To establish an organ dose database for pediatric and adolescent reference individuals undergoing computed tomography (CT) examinations by using Monte Carlo simulation. The data will permit rapid estimates of organ and effective doses for patients of different age, gender, examination type, and CT scanner model. Methods: The Monte Carlo simulation model of a Siemens Sensation 16 CT scanner previously published was employed as a base CT scanner model. A set of absorbed doses for 33 organs/tissues normalized to the product of 100 mAs and CTDI{sub vol} (mGy/100 mAs mGy) was established by coupling the CT scanner model with age-dependent reference pediatric hybrid phantoms. A series of single axial scans from the top of head to the feet of the phantoms was performed at a slice thickness of 10 mm, and at tube potentials of 80, 100, and 120 kVp. Using the established CTDI{sub vol}- and 100 mAs-normalized dose matrix, organ doses for different pediatric phantoms undergoing head, chest, abdomen-pelvis, and chest-abdomen-pelvis (CAP) scans with the Siemens Sensation 16 scanner were estimated and analyzed. The results were then compared with the values obtained from three independent published methods: CT-Expo software, organ dose for abdominal CT scan derived empirically from patient abdominal circumference, and effective dose per dose-length product (DLP). Results: Organ and effective doses were calculated and normalized to 100 mAs and CTDI{sub vol} for different CT examinations. At the same technical setting, dose to the organs, which were entirely included in the CT beam coverage, were higher by from 40 to 80% for newborn phantoms compared to those of 15-year phantoms. An increase of tube potential from 80 to 120 kVp resulted in 2.5-2.9-fold greater brain dose for head scans. The results from this study were compared with three different published studies and/or techniques. First, organ doses were compared to those given by CT-Expo which revealed dose

  7. Computer simulations of the random barrier model

    DEFF Research Database (Denmark)

    Schrøder, Thomas; Dyre, Jeppe

    2002-01-01

    A brief review of experimental facts regarding ac electronic and ionic conduction in disordered solids is given followed by a discussion of what is perhaps the simplest realistic model, the random barrier model (symmetric hopping model). Results from large scale computer simulations are presented......, focusing on universality of the ac response in the extreme disorder limit. Finally, some important unsolved problems relating to hopping models for ac conduction are listed....

  8. Mechanistic models in computational social science

    Science.gov (United States)

    Holme, Petter; Liljeros, Fredrik

    2015-09-01

    Quantitative social science is not only about regression analysis or, in general, data inference. Computer simulations of social mechanisms have an over 60 years long history. They have been used for many different purposes—to test scenarios, to test the consistency of descriptive theories (proof-of-concept models), to explore emergent phenomena, for forecasting, etc. In this essay, we sketch these historical developments, the role of mechanistic models in the social sciences and the influences from the natural and formal sciences. We argue that mechanistic computational models form a natural common ground for social and natural sciences, and look forward to possible future information flow across the social-natural divide.

  9. Mechanistic Models in Computational Social Science

    CERN Document Server

    Holme, Petter

    2015-01-01

    Quantitative social science is not only about regression analysis or, in general, data inference. Computer simulations of social mechanisms have an over 60 years long history. They have been used for many different purposes -- to test scenarios, to test the consistency of descriptive theories (proof-of-concept models), to explore emerging phenomena, for forecasting, etc. In this essay, we sketch these historical developments, the role of mechanistic models in the social sciences and the influences from natural and formal sciences. We argue that mechanistic computational models form a natural common ground for social and natural sciences, and look forward to possible future information flow across the social-natural divide.

  10. Computational modeling of failure in composite laminates

    NARCIS (Netherlands)

    Van der Meer, F.P.

    2010-01-01

    There is no state of the art computational model that is good enough for predictive simulation of the complete failure process in laminates. Already on the single ply level controversy exists. Much work has been done in recent years in the development of continuum models, but these fail to predict t

  11. Computational Intelligence. Mortality Models for the Actuary

    NARCIS (Netherlands)

    Willemse, W.J.

    2001-01-01

    This thesis applies computational intelligence to the field of actuarial (insurance) science. In particular, this thesis deals with life insurance where mortality modelling is important. Actuaries use ancient models (mortality laws) from the nineteenth century, for example Gompertz' and Makeham's la

  12. Generating computational models for serious gaming

    NARCIS (Netherlands)

    Westera, Wim

    2014-01-01

    Many serious games include computational models that simulate dynamic systems. These models promote enhanced interaction and responsiveness. Under the social web paradigm more and more usable game authoring tools become available that enable prosumers to create their own games, but the inclusion of

  13. Do's and Don'ts of Computer Models for Planning

    Science.gov (United States)

    Hammond, John S., III

    1974-01-01

    Concentrates on the managerial issues involved in computer planning models. Describes what computer planning models are and the process by which managers can increase the likelihood of computer planning models being successful in their organizations. (Author/DN)

  14. Security Management Model in Cloud Computing Environment

    OpenAIRE

    2016-01-01

    In the cloud computing environment, cloud virtual machine (VM) will be more and more the number of virtual machine security and management faced giant Challenge. In order to address security issues cloud computing virtualization environment, this paper presents a virtual machine based on efficient and dynamic deployment VM security management model state migration and scheduling, study of which virtual machine security architecture, based on AHP (Analytic Hierarchy Process) virtual machine de...

  15. On the completeness of quantum computation models

    CERN Document Server

    Arrighi, Pablo

    2010-01-01

    The notion of computability is stable (i.e. independent of the choice of an indexing) over infinite-dimensional vector spaces provided they have a finite "tensorial dimension". Such vector spaces with a finite tensorial dimension permit to define an absolute notion of completeness for quantum computation models and give a precise meaning to the Church-Turing thesis in the framework of quantum theory. (Extra keywords: quantum programming languages, denotational semantics, universality.)

  16. Parallel Computing of Ocean General Circulation Model

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper discusses the parallel computing of the thirdgeneration Ocea n General Circulation Model (OGCM) from the State Key Laboratory of Numerical Mo deling for Atmospheric Science and Geophysical Fluid Dynamics(LASG),Institute of Atmosphere Physics(IAP). Meanwhile, several optimization strategies for paralle l computing of OGCM (POGCM) on Scalable Shared Memory Multiprocessor (S2MP) are presented. Using Message Passing Interface (MPI), we obtain super linear speedup on SGI Origin 2000 for parallel OGCM(POGCM) after optimization.

  17. Finite difference computing with exponential decay models

    CERN Document Server

    Langtangen, Hans Petter

    2016-01-01

    This text provides a very simple, initial introduction to the complete scientific computing pipeline: models, discretization, algorithms, programming, verification, and visualization. The pedagogical strategy is to use one case study – an ordinary differential equation describing exponential decay processes – to illustrate fundamental concepts in mathematics and computer science. The book is easy to read and only requires a command of one-variable calculus and some very basic knowledge about computer programming. Contrary to similar texts on numerical methods and programming, this text has a much stronger focus on implementation and teaches testing and software engineering in particular. .

  18. Student motivation in a high school science laboratory: The impact of computers and other technologies on young adolescent physics students

    Science.gov (United States)

    Clark, Stephen Allan

    The impact of technology (including computers and probes, low friction carts, video camera, VCR's and electronic balances) on the motivation of adolescent science students was investigated using a naturalistic case study of college preparatory ninth grade physics classes at a comprehensive high school in the southeastern United States. The students were positively affected by the use of computer technology as compared to other "low tech" labs. The non-computer technologies had little motivational effect on the students. The most important motivational effect was the belief among the students that they could successfully operate the equipment and gather meaningful results. At times, the students spent more cognitive energy on performing the experiment than on learning the physics. This was especially true when microcomputer-based labs were used. When the technology led to results that were clear to the students and displayed in a manner that could be easily interpreted, they were generally receptive and motivated to persist at the task. Many students reported being especially motivated when a computer was used to gather the data because they "just liked computers." Furthermore, qualitative evidence suggested that they had learned the physics concept they were working on. This is in close agreement with the conceptual change model of learning in that students are most likely to change their prior conceptions when the new idea is plausible (the technology makes it so), intelligible (real time graphing, actual light rays), and fruitful (the new idea explains what they actually see). However, many of the microcomputer-based laboratory (MBL) activities and "high tech" labs were too unstructured, leaving students bewildered, confused and unmotivated. To achieve maximum motivational effects from the technology, it was necessary to reduce the cognitive demand on the students so they could concentrate on the data gathered rather than the operation of the equipment.

  19. A computational model of analogical reasoning

    Institute of Scientific and Technical Information of China (English)

    李波; 赵沁平

    1997-01-01

    A computational model of analogical reasoning is presented, which divides analogical reasoning process into four subprocesses, i.e. reminding, elaboration, matching and transfer. For each subprocess, its role and the principles it follows are given. The model is discussed in detail, including salient feature-based reminding, relevance-directed elaboration, an improved matching model and a transfer model. And the advantages of this model are summarized based on the results of BHARS, which is an analogical reasoning system implemented by this model.

  20. On the computational modeling of FSW processes

    OpenAIRE

    Agelet de Saracibar Bosch, Carlos; Chiumenti, Michèle; Santiago, Diego de; Cervera Ruiz, Miguel; Dialami, Narges; Lombera, Guillermo

    2010-01-01

    This work deals with the computational modeling and numerical simulation of Friction Stir Welding (FSW) processes. Here a quasi-static, transient, mixed stabilized Eulerian formulation is used. Norton-Hoff and Sheppard-Wright rigid thermoplastic material models have been considered. A product formula algorithm, leading to a staggered solution scheme, has been used. The model has been implemented into the in-house developed FE code COMET. Results obtained in the simulation of FSW process are c...

  1. Computational disease modeling – fact or fiction?

    Directory of Open Access Journals (Sweden)

    Stephan Klaas

    2009-06-01

    Full Text Available Abstract Background Biomedical research is changing due to the rapid accumulation of experimental data at an unprecedented scale, revealing increasing degrees of complexity of biological processes. Life Sciences are facing a transition from a descriptive to a mechanistic approach that reveals principles of cells, cellular networks, organs, and their interactions across several spatial and temporal scales. There are two conceptual traditions in biological computational-modeling. The bottom-up approach emphasizes complex intracellular molecular models and is well represented within the systems biology community. On the other hand, the physics-inspired top-down modeling strategy identifies and selects features of (presumably essential relevance to the phenomena of interest and combines available data in models of modest complexity. Results The workshop, "ESF Exploratory Workshop on Computational disease Modeling", examined the challenges that computational modeling faces in contributing to the understanding and treatment of complex multi-factorial diseases. Participants at the meeting agreed on two general conclusions. First, we identified the critical importance of developing analytical tools for dealing with model and parameter uncertainty. Second, the development of predictive hierarchical models spanning several scales beyond intracellular molecular networks was identified as a major objective. This contrasts with the current focus within the systems biology community on complex molecular modeling. Conclusion During the workshop it became obvious that diverse scientific modeling cultures (from computational neuroscience, theory, data-driven machine-learning approaches, agent-based modeling, network modeling and stochastic-molecular simulations would benefit from intense cross-talk on shared theoretical issues in order to make progress on clinically relevant problems.

  2. An improved computational constitutive model for glass

    Science.gov (United States)

    Holmquist, Timothy J.; Johnson, Gordon R.; Gerlach, Charles A.

    2017-01-01

    In 2011, Holmquist and Johnson presented a model for glass subjected to large strains, high strain rates and high pressures. It was later shown that this model produced solutions that were severely mesh dependent, converging to a solution that was much too strong. This article presents an improved model for glass that uses a new approach to represent the interior and surface strength that is significantly less mesh dependent. This new formulation allows for the laboratory data to be accurately represented (including the high tensile strength observed in plate-impact spall experiments) and produces converged solutions that are in good agreement with ballistic data. The model also includes two new features: one that decouples the damage model from the strength model, providing more flexibility in defining the onset of permanent deformation; the other provides for a variable shear modulus that is dependent on the pressure. This article presents a review of the original model, a description of the improved model and a comparison of computed and experimental results for several sets of ballistic data. Of special interest are computed and experimental results for two impacts onto a single target, and the ability to compute the damage velocity in agreement with experiment data. This article is part of the themed issue 'Experimental testing and modelling of brittle materials at high strain rates'.

  3. The application of computer assisted technologies (CAT in the rehabilitation of cognitive functions in psychiatric disorders of childhood and adolescence

    Directory of Open Access Journals (Sweden)

    Tomasz Srebnicki

    2016-06-01

    Full Text Available First applications of computer-assisted technologies (CAT in the rehabilitation of cognitive deficits, including child and adolescent psychiatric disorders date back to the 80’s last century. Recent developments in computer technologies, wide access to the Internet and vast expansion of electronic devices resulted in dynamic increase in therapeutic software as well as supporting devices. The aim of computer assisted technologies is the improvement in the comfort and quality of life as well as the rehabilitation of impaired functions. The goal of the article is the presentation of most common computer-assisted technologies used in the therapy of children and adolescents with cognitive deficits as well as the literature review of their effectiveness including the challenges and limitations in regard to the implementation of such interventions.

  4. Time series modeling, computation, and inference

    CERN Document Server

    Prado, Raquel

    2010-01-01

    The authors systematically develop a state-of-the-art analysis and modeling of time series. … this book is well organized and well written. The authors present various statistical models for engineers to solve problems in time series analysis. Readers no doubt will learn state-of-the-art techniques from this book.-Hsun-Hsien Chang, Computing Reviews, March 2012My favorite chapters were on dynamic linear models and vector AR and vector ARMA models.-William Seaver, Technometrics, August 2011… a very modern entry to the field of time-series modelling, with a rich reference list of the current lit

  5. Computer Aided Modelling – Opportunities and Challenges

    DEFF Research Database (Denmark)

    Cameron, Ian; Gani, Rafiqul

    2011-01-01

    -based solutions to significant problems? The important issues of workflow and data flow are discussed together with fit-for-purpose model development. As well, the lack of tools around multiscale modelling provides opportunities for the development of efficient tools to address such challenges. The ability......This chapter considers the opportunities that are present in developing, extending and applying aspects of computer-aided modelling principles and practice. What are the best tasks to be done by modellers and what needs the application of CAPE tools? How do we efficiently develop model...... and opportunities are discussed for such systems....

  6. Computational algebraic geometry of epidemic models

    Science.gov (United States)

    Rodríguez Vega, Martín.

    2014-06-01

    Computational Algebraic Geometry is applied to the analysis of various epidemic models for Schistosomiasis and Dengue, both, for the case without control measures and for the case where control measures are applied. The models were analyzed using the mathematical software Maple. Explicitly the analysis is performed using Groebner basis, Hilbert dimension and Hilbert polynomials. These computational tools are included automatically in Maple. Each of these models is represented by a system of ordinary differential equations, and for each model the basic reproductive number (R0) is calculated. The effects of the control measures are observed by the changes in the algebraic structure of R0, the changes in Groebner basis, the changes in Hilbert dimension, and the changes in Hilbert polynomials. It is hoped that the results obtained in this paper become of importance for designing control measures against the epidemic diseases described. For future researches it is proposed the use of algebraic epidemiology to analyze models for airborne and waterborne diseases.

  7. Biomedical Imaging and Computational Modeling in Biomechanics

    CERN Document Server

    Iacoviello, Daniela

    2013-01-01

    This book collects the state-of-art and new trends in image analysis and biomechanics. It covers a wide field of scientific and cultural topics, ranging from remodeling of bone tissue under the mechanical stimulus up to optimizing the performance of sports equipment, through the patient-specific modeling in orthopedics, microtomography and its application in oral and implant research, computational modeling in the field of hip prostheses, image based model development and analysis of the human knee joint, kinematics of the hip joint, micro-scale analysis of compositional and mechanical properties of dentin, automated techniques for cervical cell image analysis, and iomedical imaging and computational modeling in cardiovascular disease.   The book will be of interest to researchers, Ph.D students, and graduate students with multidisciplinary interests related to image analysis and understanding, medical imaging, biomechanics, simulation and modeling, experimental analysis.

  8. Perceived problems with computer gaming and internet use among adolescents: measurement tool for non-clinical survey studies

    OpenAIRE

    Holstein, Bjørn E.; Pedersen, Trine Pagh; Bendtsen, Pernille; Madsen, Katrine Rich; Meilstrup, Charlotte Riebeling; Nielsen, Line; Rasmussen, Mette

    2014-01-01

    Background Existing instruments for measuring problematic computer and console gaming and internet use are often lengthy and often based on a pathological perspective. The objective was to develop and present a new and short non-clinical measurement tool for perceived problems related to computer use and gaming among adolescents and to study the association between screen time and perceived problems. Methods Cross-sectional school-survey of 11-, 13-, and 15-year old students in thirteen schoo...

  9. Computer-associated health complaints and sources of ergonomic instructions in computer-related issues among Finnish adolescents: A cross-sectional study

    Directory of Open Access Journals (Sweden)

    Ketola Ritva L

    2010-01-01

    Full Text Available Abstract Background The use of computers has increased among adolescents, as have musculoskeletal symptoms. There is evidence that these symptoms can be reduced through an ergonomics approach and through education. The purpose of this study was to examine where adolescents had received ergonomic instructions related to computer use, and whether receiving these instructions was associated with a reduced prevalence of computer-associated health complaints. Methods Mailed survey with nationally representative sample of 12 to 18-year-old Finns in 2001 (n = 7292, response rate 70%. In total, 6961 youths reported using a computer. We tested the associations of computer use time and received ergonomic instructions (predictor variables with computer-associated health complaints (outcome variables using logistic regression analysis. Results To prevent computer-associated complaints, 61.2% reported having been instructed to arrange their desk/chair/screen in the right position, 71.5% to take rest breaks. The older age group (16-18 years reported receiving instructions or being self-instructed more often than the 12- to 14-year-olds (p Conclusions This report shows that ergonomic instructions on how to prevent computer-related musculoskeletal problems fail to reach a substantial number of children. Furthermore, the reported sources of instructions vary greatly in terms of reliability.

  10. Modelling the effects of sexting on the transmission dynamics of HSV-2 amongst adolescents

    Directory of Open Access Journals (Sweden)

    A. Mhlanga

    2015-12-01

    Full Text Available Prior studies have indicated that adolescents who are into sexting are likely to engage in risky sexual behaviours. In this paper, a mathematical model to assess the impact of sexting and peer influence on the spread of HSV-2 amongst adolescents is developed. The threshold parameters of the model are determined and stabilities are analysed. The impact of filtering and awareness campaigns is explored. Results from the study suggest that HSV-2 prevalence is high amongst adolescents who are into sexting as compared to those who do not. Further, we applied optimal control theory to the proposed model. The controls represent filtering and awareness campaigns. The objective is based on minimising the susceptible sexting adolescents, infected non-sexting adolescents and the infected sexting adolescents. The optimal control is characterised and numerically solved. Overall, the application of optimal control theory suggests that more effort should be devoted to both controls, filtering and awareness campaigns.

  11. Utilizing computer models for optimizing classroom acoustics

    Science.gov (United States)

    Hinckley, Jennifer M.; Rosenberg, Carl J.

    2002-05-01

    The acoustical conditions in a classroom play an integral role in establishing an ideal learning environment. Speech intelligibility is dependent on many factors, including speech loudness, room finishes, and background noise levels. The goal of this investigation was to use computer modeling techniques to study the effect of acoustical conditions on speech intelligibility in a classroom. This study focused on a simulated classroom which was generated using the CATT-acoustic computer modeling program. The computer was utilized as an analytical tool in an effort to optimize speech intelligibility in a typical classroom environment. The factors that were focused on were reverberation time, location of absorptive materials, and background noise levels. Speech intelligibility was measured with the Rapid Speech Transmission Index (RASTI) method.

  12. Applied Mathematics, Modelling and Computational Science

    CERN Document Server

    Kotsireas, Ilias; Makarov, Roman; Melnik, Roderick; Shodiev, Hasan

    2015-01-01

    The Applied Mathematics, Modelling, and Computational Science (AMMCS) conference aims to promote interdisciplinary research and collaboration. The contributions in this volume cover the latest research in mathematical and computational sciences, modeling, and simulation as well as their applications in natural and social sciences, engineering and technology, industry, and finance. The 2013 conference, the second in a series of AMMCS meetings, was held August 26–30 and organized in cooperation with AIMS and SIAM, with support from the Fields Institute in Toronto, and Wilfrid Laurier University. There were many young scientists at AMMCS-2013, both as presenters and as organizers. This proceedings contains refereed papers contributed by the participants of the AMMCS-2013 after the conference. This volume is suitable for researchers and graduate students, mathematicians and engineers, industrialists, and anyone who would like to delve into the interdisciplinary research of applied and computational mathematics ...

  13. Integrating interactive computational modeling in biology curricula.

    Directory of Open Access Journals (Sweden)

    Tomáš Helikar

    2015-03-01

    Full Text Available While the use of computer tools to simulate complex processes such as computer circuits is normal practice in fields like engineering, the majority of life sciences/biological sciences courses continue to rely on the traditional textbook and memorization approach. To address this issue, we explored the use of the Cell Collective platform as a novel, interactive, and evolving pedagogical tool to foster student engagement, creativity, and higher-level thinking. Cell Collective is a Web-based platform used to create and simulate dynamical models of various biological processes. Students can create models of cells, diseases, or pathways themselves or explore existing models. This technology was implemented in both undergraduate and graduate courses as a pilot study to determine the feasibility of such software at the university level. First, a new (In Silico Biology class was developed to enable students to learn biology by "building and breaking it" via computer models and their simulations. This class and technology also provide a non-intimidating way to incorporate mathematical and computational concepts into a class with students who have a limited mathematical background. Second, we used the technology to mediate the use of simulations and modeling modules as a learning tool for traditional biological concepts, such as T cell differentiation or cell cycle regulation, in existing biology courses. Results of this pilot application suggest that there is promise in the use of computational modeling and software tools such as Cell Collective to provide new teaching methods in biology and contribute to the implementation of the "Vision and Change" call to action in undergraduate biology education by providing a hands-on approach to biology.

  14. Integrating interactive computational modeling in biology curricula.

    Science.gov (United States)

    Helikar, Tomáš; Cutucache, Christine E; Dahlquist, Lauren M; Herek, Tyler A; Larson, Joshua J; Rogers, Jim A

    2015-03-01

    While the use of computer tools to simulate complex processes such as computer circuits is normal practice in fields like engineering, the majority of life sciences/biological sciences courses continue to rely on the traditional textbook and memorization approach. To address this issue, we explored the use of the Cell Collective platform as a novel, interactive, and evolving pedagogical tool to foster student engagement, creativity, and higher-level thinking. Cell Collective is a Web-based platform used to create and simulate dynamical models of various biological processes. Students can create models of cells, diseases, or pathways themselves or explore existing models. This technology was implemented in both undergraduate and graduate courses as a pilot study to determine the feasibility of such software at the university level. First, a new (In Silico Biology) class was developed to enable students to learn biology by "building and breaking it" via computer models and their simulations. This class and technology also provide a non-intimidating way to incorporate mathematical and computational concepts into a class with students who have a limited mathematical background. Second, we used the technology to mediate the use of simulations and modeling modules as a learning tool for traditional biological concepts, such as T cell differentiation or cell cycle regulation, in existing biology courses. Results of this pilot application suggest that there is promise in the use of computational modeling and software tools such as Cell Collective to provide new teaching methods in biology and contribute to the implementation of the "Vision and Change" call to action in undergraduate biology education by providing a hands-on approach to biology.

  15. Computational models for synthetic marine infrared clutter

    Science.gov (United States)

    Constantikes, Kim T.; Zysnarski, Adam H.

    1996-06-01

    The next generation of ship defense missiles will need to engage stealthy, passive, sea-skimming missiles. Detection and guidance will occur against a background of sea surface and horizon which can present significant clutter problems for infrared seekers, particularly when targets are comparatively dim. We need a variety of sea clutter models: statistical image models for signal processing algorithm design, clutter occurrence models for systems effectiveness assessment, and constructive image models for synthesizing very large field-of-view (FOV) images with high spatial and temporal resolution. We have implemented and tested such a constructive model. First principle models of water waves and light transport provide a computationally intensive clutter model implemented as a raytracer. Our models include sea, sky, and solar radiance; reflectance; attenuating atmospheres; constructive solid geometry targets; target and water wave dynamics; and simple sensor image formation.

  16. A Stochastic Dynamic Model of Computer Viruses

    Directory of Open Access Journals (Sweden)

    Chunming Zhang

    2012-01-01

    Full Text Available A stochastic computer virus spread model is proposed and its dynamic behavior is fully investigated. Specifically, we prove the existence and uniqueness of positive solutions, and the stability of the virus-free equilibrium and viral equilibrium by constructing Lyapunov functions and applying Ito's formula. Some numerical simulations are finally given to illustrate our main results.

  17. Integer Programming Models for Computational Biology Problems

    Institute of Scientific and Technical Information of China (English)

    Giuseppe Lancia

    2004-01-01

    The recent years have seen an impressive increase in the use of Integer Programming models for the solution of optimization problems originating in Molecular Biology. In this survey, some of the most successful Integer Programming approaches are described, while a broad overview of application areas being is given in modern Computational Molecular Biology.

  18. Computational modelling for dry-powder inhalers

    NARCIS (Netherlands)

    Kröger, Ralf; Woolhouse, Robert; Becker, Michael; Wachtel, Herbert; de Boer, Anne; Horner, Marc

    2012-01-01

    Computational fluid dynamics (CFD) is a simulation tool used for modelling powder flow through inhalers to allow optimisation both of device design and drug powder. Here, Ralf Kröger, Consulting Senior CFD Engineer, ANSYS Germany GmbH; Marc Horner, Lead Technical Services Engineer, Healthcare, ANSYS

  19. Agent based computational model of trust

    NARCIS (Netherlands)

    A. Gorobets (Alexander); B. Nooteboom (Bart)

    2004-01-01

    textabstractThis paper employs the methodology of Agent-Based Computational Economics (ACE) to investigate under what conditions trust can be viable in markets. The emergence and breakdown of trust is modeled in a context of multiple buyers and suppliers. Agents adapt their trust in a partner, the w

  20. STEW A Nonlinear Data Modeling Computer Program

    CERN Document Server

    Chen, H

    2000-01-01

    A nonlinear data modeling computer program, STEW, employing the Levenberg-Marquardt algorithm, has been developed to model the experimental sup 2 sup 3 sup 9 Pu(n,f) and sup 2 sup 3 sup 5 U(n,f) cross sections. This report presents results of the modeling of the sup 2 sup 3 sup 9 Pu(n,f) and sup 2 sup 3 sup 5 U(n,f) cross-section data. The calculation of the fission transmission coefficient is based on the double-humped-fission-barrier model of Bjornholm and Lynn. Incident neutron energies of up to 5 MeV are considered.

  1. STEW: A Nonlinear Data Modeling Computer Program

    Energy Technology Data Exchange (ETDEWEB)

    Chen, H.

    2000-03-04

    A nonlinear data modeling computer program, STEW, employing the Levenberg-Marquardt algorithm, has been developed to model the experimental {sup 239}Pu(n,f) and {sup 235}U(n,f) cross sections. This report presents results of the modeling of the {sup 239}Pu(n,f) and {sup 235}U(n,f) cross-section data. The calculation of the fission transmission coefficient is based on the double-humped-fission-barrier model of Bjornholm and Lynn. Incident neutron energies of up to 5 MeV are considered.

  2. Evaluating computational models of cholesterol metabolism.

    Science.gov (United States)

    Paalvast, Yared; Kuivenhoven, Jan Albert; Groen, Albert K

    2015-10-01

    Regulation of cholesterol homeostasis has been studied extensively during the last decades. Many of the metabolic pathways involved have been discovered. Yet important gaps in our knowledge remain. For example, knowledge on intracellular cholesterol traffic and its relation to the regulation of cholesterol synthesis and plasma cholesterol levels is incomplete. One way of addressing the remaining questions is by making use of computational models. Here, we critically evaluate existing computational models of cholesterol metabolism making use of ordinary differential equations and addressed whether they used assumptions and make predictions in line with current knowledge on cholesterol homeostasis. Having studied the results described by the authors, we have also tested their models. This was done primarily by testing the effect of statin treatment in each model. Ten out of eleven models tested have made assumptions in line with current knowledge of cholesterol metabolism. Three out of the ten remaining models made correct predictions, i.e. predicting a decrease in plasma total and LDL cholesterol or increased uptake of LDL upon treatment upon the use of statins. In conclusion, few models on cholesterol metabolism are able to pass a functional test. Apparently most models have not undergone the critical iterative systems biology cycle of validation. We expect modeling of cholesterol metabolism to go through many more model topologies and iterative cycles and welcome the increased understanding of cholesterol metabolism these are likely to bring.

  3. Applied modelling and computing in social science

    CERN Document Server

    Povh, Janez

    2015-01-01

    In social science outstanding results are yielded by advanced simulation methods, based on state of the art software technologies and an appropriate combination of qualitative and quantitative methods. This book presents examples of successful applications of modelling and computing in social science: business and logistic process simulation and optimization, deeper knowledge extractions from big data, better understanding and predicting of social behaviour and modelling health and environment changes.

  4. Mechanistic models in computational social science

    OpenAIRE

    Petter eHolme; Fredrik eLiljeros

    2015-01-01

    Quantitative social science is not only about regression analysis or, in general, data inference. Computer simulations of social mechanisms have an over 60 years long history. They have been used for many different purposes—to test scenarios, to test the consistency of descriptive theories (proof-of-concept models), to explore emergent phenomena, for forecasting, etc. In this essay, we sketch these historical developments, the role of mechanistic models in the social sciences and the influenc...

  5. Mechanistic models in computational social science

    OpenAIRE

    Holme, Petter; Liljeros, Fredrik

    2015-01-01

    Quantitative social science is not only about regression analysis or, in general, data inference. Computer simulations of social mechanisms have an over 60 years long history. They have been used for many different purposes -- to test scenarios, to test the consistency of descriptive theories (proof-of-concept models), to explore emergent phenomena, for forecasting, etc. In this essay, we sketch these historical developments, the role of mechanistic models in the social sciences and the influ...

  6. A Dualistic Model To Describe Computer Architectures

    Science.gov (United States)

    Nitezki, Peter; Engel, Michael

    1985-07-01

    The Dualistic Model for Computer Architecture Description uses a hierarchy of abstraction levels to describe a computer in arbitrary steps of refinement from the top of the user interface to the bottom of the gate level. In our Dualistic Model the description of an architecture may be divided into two major parts called "Concept" and "Realization". The Concept of an architecture on each level of the hierarchy is an Abstract Data Type that describes the functionality of the computer and an implementation of that data type relative to the data type of the next lower level of abstraction. The Realization on each level comprises a language describing the means of user interaction with the machine, and a processor interpreting this language in terms of the language of the lower level. The surface of each hierarchical level, the data type and the language express the behaviour of a ma-chine at this level, whereas the implementation and the processor describe the structure of the algorithms and the system. In this model the Principle of Operation maps the object and computational structure of the Concept onto the structures of the Realization. Describing a system in terms of the Dualistic Model is therefore a process of refinement starting at a mere description of behaviour and ending at a description of structure. This model has proven to be a very valuable tool in exploiting the parallelism in a problem and it is very transparent in discovering the points where par-allelism is lost in a special architecture. It has successfully been used in a project on a survey of Computer Architecture for Image Processing and Pattern Analysis in Germany.

  7. Loneliness and solitude in adolescence: A confirmatory factor analysis of alternative models

    DEFF Research Database (Denmark)

    Goossens, Luc; Lasgaard, Mathias; Luyckx, Koen

    2009-01-01

    The present study tested a four-factor model of adolescent loneliness and solitude that comprises peer-related loneliness, family loneliness, negative attitude toward solitude, and positive attitude toward solitude. Nine different instruments for a total of 14 scales and derivative subscales were...... of the Loneliness and Aloneness Scale for Children and Adolescents (LACA) is recommended, because the instrument measures all four aspects of the model. Implications for current theories on adolescent loneliness and associated phenomena, such as adolescents' attitude toward being on their own, are briefly discussed....

  8. Modelling the Progression of Male Swimmers’ Performances through Adolescence

    Directory of Open Access Journals (Sweden)

    Shilo J. Dormehl

    2016-01-01

    Full Text Available Insufficient data on adolescent athletes is contributing to the challenges facing youth athletic development and accurate talent identification. The purpose of this study was to model the progression of male sub-elite swimmers’ performances during adolescence. The performances of 446 males (12–19 year olds competing in seven individual events (50, 100, 200 m freestyle, 100 m backstroke, breaststroke, butterfly, 200 m individual medley over an eight-year period at an annual international schools swimming championship, run under FINA regulations were collected. Quadratic functions for each event were determined using mixed linear models. Thresholds of peak performance were achieved between the ages of 18.5 ± 0.1 (50 m freestyle and 200 m individual medley and 19.8 ± 0.1 (100 m butterfly years. The slowest rate of improvement was observed in the 200 m individual medley (20.7% and the highest in the 100 m butterfly (26.2%. Butterfly does however appear to be one of the last strokes in which males specialise. The models may be useful as talent identification tools, as they predict the age at which an average sub-elite swimmer could potentially peak. The expected rate of improvement could serve as a tool in which to monitor and evaluate benchmarks.

  9. Predicting Adolescent Sexual and Contraceptive Behavior: An Application and Test of the Fishbein Model.

    Science.gov (United States)

    Jorgensen, Stephen R.; Sonstegard, Janet S.

    1984-01-01

    Presents a test of the Fishbein model of behavior prediction applied to predict the pregnancy risk-taking behavior of adolescent females (N=244). Analyses of data showed that the Fishbein model of attitude-behavior consistency seems to be applicable to the fertility-related behavior of adolescent females. (LLL)

  10. Social Contagion, Adolescent Sexual Behavior, and Pregnancy: A Nonlinear Dynamic EMOSA Model.

    Science.gov (United States)

    Rodgers, Joseph Lee; Rowe, David C.; Buster, Maury

    1998-01-01

    Expands an existing nonlinear dynamic epidemic model of onset of social activities (EMOSA), motivated by social contagion theory, to quantify the likelihood of pregnancy for adolescent girls of different sexuality statuses. Compares five sexuality/pregnancy models to explain variance in national prevalence curves. Finds that adolescent girls have…

  11. Middle Grades' School Models and Their Impact on Early Adolescent Self-Esteem

    Science.gov (United States)

    Booth, Margaret Zoller; Sheehan, Heather Chase; Earley, Mark A.

    2007-01-01

    Throughout the world, school grade structures are most variable during the early adolescent years when students can find themselves in a variety of school models. This paper investigates the impact of two popular school models in the United States (middle school and K-8) on the self-esteem and self-concept of early adolescents. Based on mixed…

  12. A Model for Subjective Well-Being in Adolescence: Need Satisfaction and Reasons for Living

    Science.gov (United States)

    Eryilmaz, Ali

    2012-01-01

    Subjective well-being is as important for adolescents as it is in other stages of life. This study thus aims to develop a model for subjective well-being, which is limited to need satisfaction in adolescence and reasons for living, and to test the validity of the model. Participants were a total of 227 individuals, 120 females and 107 males. Data…

  13. Computer Model Of Fragmentation Of Atomic Nuclei

    Science.gov (United States)

    Wilson, John W.; Townsend, Lawrence W.; Tripathi, Ram K.; Norbury, John W.; KHAN FERDOUS; Badavi, Francis F.

    1995-01-01

    High Charge and Energy Semiempirical Nuclear Fragmentation Model (HZEFRG1) computer program developed to be computationally efficient, user-friendly, physics-based program for generating data bases on fragmentation of atomic nuclei. Data bases generated used in calculations pertaining to such radiation-transport applications as shielding against radiation in outer space, radiation dosimetry in outer space, cancer therapy in laboratories with beams of heavy ions, and simulation studies for designing detectors for experiments in nuclear physics. Provides cross sections for production of individual elements and isotopes in breakups of high-energy heavy ions by combined nuclear and Coulomb fields of interacting nuclei. Written in ANSI FORTRAN 77.

  14. Processor core model for quantum computing.

    Science.gov (United States)

    Yung, Man-Hong; Benjamin, Simon C; Bose, Sougato

    2006-06-09

    We describe an architecture based on a processing "core," where multiple qubits interact perpetually, and a separate "store," where qubits exist in isolation. Computation consists of single qubit operations, swaps between the store and the core, and free evolution of the core. This enables computation using physical systems where the entangling interactions are "always on." Alternatively, for switchable systems, our model constitutes a prescription for optimizing many-qubit gates. We discuss implementations of the quantum Fourier transform, Hamiltonian simulation, and quantum error correction.

  15. Mechanistic models in computational social science

    Directory of Open Access Journals (Sweden)

    Petter eHolme

    2015-09-01

    Full Text Available Quantitative social science is not only about regression analysis or, in general, data inference. Computer simulations of social mechanisms have an over 60 years long history. They have been used for many different purposes—to test scenarios, to test the consistency of descriptive theories (proof-of-concept models, to explore emergent phenomena, for forecasting, etc. In this essay, we sketch these historical developments, the role of mechanistic models in the social sciences and the influences from the natural and formal sciences. We argue that mechanistic computational models form a natural common ground for social and natural sciences, and look forward to possible future information flow across the social-natural divide.

  16. Computer Aided Design Modeling for Heterogeneous Objects

    CERN Document Server

    Gupta, Vikas; Tandon, Puneet

    2010-01-01

    Heterogeneous object design is an active research area in recent years. The conventional CAD modeling approaches only provide geometry and topology of the object, but do not contain any information with regard to the materials of the object and so can not be used for the fabrication of heterogeneous objects (HO) through rapid prototyping. Current research focuses on computer-aided design issues in heterogeneous object design. A new CAD modeling approach is proposed to integrate the material information into geometric regions thus model the material distributions in the heterogeneous object. The gradient references are used to represent the complex geometry heterogeneous objects which have simultaneous geometry intricacies and accurate material distributions. The gradient references helps in flexible manipulability and control to heterogeneous objects, which guarantees the local control over gradient regions of developed heterogeneous objects. A systematic approach on data flow, processing, computer visualizat...

  17. Computational modelling of evolution: ecosystems and language

    CERN Document Server

    Lipowski, Adam

    2008-01-01

    Recently, computational modelling became a very important research tool that enables us to study problems that for decades evaded scientific analysis. Evolutionary systems are certainly examples of such problems: they are composed of many units that might reproduce, diffuse, mutate, die, or in some cases for example communicate. These processes might be of some adaptive value, they influence each other and occur on various time scales. That is why such systems are so difficult to study. In this paper we briefly review some computational approaches, as well as our contributions, to the evolution of ecosystems and language. We start from Lotka-Volterra equations and the modelling of simple two-species prey-predator systems. Such systems are canonical example for studying oscillatory behaviour in competitive populations. Then we describe various approaches to study long-term evolution of multi-species ecosystems. We emphasize the need to use models that take into account both ecological and evolutionary processe...

  18. Computational Modeling of Vortex Generators for Turbomachinery

    Science.gov (United States)

    Chima, R. V.

    2002-01-01

    In this work computational models were developed and used to investigate applications of vortex generators (VGs) to turbomachinery. The work was aimed at increasing the efficiency of compressor components designed for the NASA Ultra Efficient Engine Technology (UEET) program. Initial calculations were used to investigate the physical behavior of VGs. A parametric study of the effects of VG height was done using 3-D calculations of isolated VGs. A body force model was developed to simulate the effects of VGs without requiring complicated grids. The model was calibrated using 2-D calculations of the VG vanes and was validated using the 3-D results. Then three applications of VGs to a compressor rotor and stator were investigated: 1) The results of the 3-D calculations were used to simulate the use of small casing VGs used to generate rotor preswirl or counterswirl. Computed performance maps were used to evaluate the effects of VGs. 2) The body force model was used to simulate large part-span splitters on the casing ahead of the stator. Computed loss buckets showed the effects of the VGs. 3) The body force model was also used to investigate the use of tiny VGs on the stator suction surface for controlling secondary flows. Near-surface particle traces and exit loss profiles were used to evaluate the effects of the VGs.

  19. Rough – Granular Computing knowledge discovery models

    Directory of Open Access Journals (Sweden)

    Mohammed M. Eissa

    2016-11-01

    Full Text Available Medical domain has become one of the most important areas of research in order to richness huge amounts of medical information about the symptoms of diseases and how to distinguish between them to diagnose it correctly. Knowledge discovery models play vital role in refinement and mining of medical indicators to help medical experts to settle treatment decisions. This paper introduces four hybrid Rough – Granular Computing knowledge discovery models based on Rough Sets Theory, Artificial Neural Networks, Genetic Algorithm and Rough Mereology Theory. A comparative analysis of various knowledge discovery models that use different knowledge discovery techniques for data pre-processing, reduction, and data mining supports medical experts to extract the main medical indicators, to reduce the misdiagnosis rates and to improve decision-making for medical diagnosis and treatment. The proposed models utilized two medical datasets: Coronary Heart Disease dataset and Hepatitis C Virus dataset. The main purpose of this paper was to explore and evaluate the proposed models based on Granular Computing methodology for knowledge extraction according to different evaluation criteria for classification of medical datasets. Another purpose is to make enhancement in the frame of KDD processes for supervised learning using Granular Computing methodology.

  20. Sticker DNA computer model--PartⅡ:Application

    Institute of Scientific and Technical Information of China (English)

    XU Jin; LI Sanping; DONG Yafei; WEI Xiaopeng

    2004-01-01

    Sticker model is one of the basic models in the DNA computer models. This model is coded with single-double stranded DNA molecules. It has the following advantages that the operations require no strands extension and use no enzymes; What's more, the materials are reusable. Therefore, it arouses attention and interest of scientists in many fields. In this paper, we extend and improve the sticker model, which will be definitely beneficial to the construction of DNA computer. This paper is the second part of our series paper, which mainly focuses on the application of sticker model. It mainly consists of the following three sections: the matrix representation of sticker model is first presented; then a brief review of the past research on graph and combinatorial optimization, such as the minimal set covering problem, the vertex covering problem, Hamiltonian path or cycle problem, the maximal clique problem, the maximal independent problem and the Steiner spanning tree problem, is described; Finally a DNA algorithm for the graph isomorphic problem based on the sticker model is given.

  1. Computing the complexity for Schelling segregation models

    Science.gov (United States)

    Gerhold, Stefan; Glebsky, Lev; Schneider, Carsten; Weiss, Howard; Zimmermann, Burkhard

    2008-12-01

    The Schelling segregation models are "agent based" population models, where individual members of the population (agents) interact directly with other agents and move in space and time. In this note we study one-dimensional Schelling population models as finite dynamical systems. We define a natural notion of entropy which measures the complexity of the family of these dynamical systems. The entropy counts the asymptotic growth rate of the number of limit states. We find formulas and deduce precise asymptotics for the number of limit states, which enable us to explicitly compute the entropy.

  2. Computer Modelling of 3D Geological Surface

    CERN Document Server

    Kodge, B G

    2011-01-01

    The geological surveying presently uses methods and tools for the computer modeling of 3D-structures of the geographical subsurface and geotechnical characterization as well as the application of geoinformation systems for management and analysis of spatial data, and their cartographic presentation. The objectives of this paper are to present a 3D geological surface model of Latur district in Maharashtra state of India. This study is undertaken through the several processes which are discussed in this paper to generate and visualize the automated 3D geological surface model of a projected area.

  3. Body image and adolescence: A behavioral impairment model.

    Science.gov (United States)

    Senín-Calderón, Cristina; Rodríguez-Testal, Juan F; Perona-Garcelán, Salvador; Perpiñá, Conxa

    2017-02-01

    Adolescence is a period marked by important physical and social changes that can lead to a negative body image. The purpose of this study was to find a model enabling the appearance of behavioral impairment related to body image (restrictions, avoidance, and checking) to be predicted by body image attitudes (concern or Appearance Orientation, and dissatisfaction or Appearance Evaluation), Gender, emotional symptomatology, self-consciousness, ideas of reference (IR) and age. A total of 661 participants (67.47% girls) with an average age of 17.14 years (SD=2.34) filled in the GHQ-28, SCS on self-consciousness, REF referential thinking scale, MBSRQ (AO and AE), and BIAQ. A partial mediation model was found for IR, age and depressive symptomatology between dissatisfaction and concern about body image and Gender, to behavioral impairment related to body image. The results found suggest that age, depressive symptomatology, and IR may be mediator variables in the relationship between dissatisfaction and concern about body image, on body image behavioral impairment. This relationship implies a severity to be considered in intervention and monitoring of body image behavioral impairments in adolescents.

  4. Analyzing Cultural Models in Adolescent Accounts of Romantic Relationships

    Science.gov (United States)

    Milbrath, Constance; Ohlson, Brightstar; Eyre, Stephen L.

    2009-01-01

    Research on academic achievement has led the way in demonstrating how culturally constructed meanings shape adolescent scholastic behavior. The aim of this research is to move this standpoint of analysis more centrally into the area of adolescent dating and sexuality by focusing on the cultural components of adolescent romantic relationships. This…

  5. Computer Modelling and Simulation for Inventory Control

    Directory of Open Access Journals (Sweden)

    G.K. Adegoke

    2012-07-01

    Full Text Available This study concerns the role of computer simulation as a device for conducting scientific experiments on inventory control. The stores function utilizes a bulk of physical assets and engages a bulk of financial resources in a manufacturing outfit therefore there is a need for an efficient inventory control. The reason being that inventory control reduces cost of production and thereby facilitates the effective and efficient accomplishment of production objectives of an organization. Some mathematical and statistical models were used to compute the Economic Order Quantity (EOQ. Test data were gotten from a manufacturing company and same were simulated. The results generated were used to predict a real life situation and have been presented and discussed. The language of implementation for the three models is Turbo Pascal due to its capability, generality and flexibility as a scientific programming language.

  6. Computational hemodynamics theory, modelling and applications

    CERN Document Server

    Tu, Jiyuan; Wong, Kelvin Kian Loong

    2015-01-01

    This book discusses geometric and mathematical models that can be used to study fluid and structural mechanics in the cardiovascular system.  Where traditional research methodologies in the human cardiovascular system are challenging due to its invasive nature, several recent advances in medical imaging and computational fluid and solid mechanics modelling now provide new and exciting research opportunities. This emerging field of study is multi-disciplinary, involving numerical methods, computational science, fluid and structural mechanics, and biomedical engineering. Certainly any new student or researcher in this field may feel overwhelmed by the wide range of disciplines that need to be understood. This unique book is one of the first to bring together knowledge from multiple disciplines, providing a starting point to each of the individual disciplines involved, attempting to ease the steep learning curve. This book presents elementary knowledge on the physiology of the cardiovascular system; basic knowl...

  7. A computer model of auditory stream segregation.

    Science.gov (United States)

    Beauvois, M W; Meddis, R

    1991-08-01

    A computer model is described which simulates some aspects of auditory stream segregation. The model emphasizes the explanatory power of simple physiological principles operating at a peripheral rather than a central level. The model consists of a multi-channel bandpass-filter bank with a "noisy" output and an attentional mechanism that responds selectively to the channel with the greatest activity. A "leaky integration" principle allows channel excitation to accumulate and dissipate over time. The model produces similar results to two experimental demonstrations of streaming phenomena, which are presented in detail. These results are discussed in terms of the "emergent properties" of a system governed by simple physiological principles. As such the model is contrasted with higher-level Gestalt explanations of the same phenomena while accepting that they may constitute complementary kinds of explanation.

  8. AMAR: A Computational Model of Autosegmental Phonology

    Science.gov (United States)

    1993-10-01

    the 8th International Joint Conference on Artificial Inteligence . 683-5. Koskenniemi, K. 1984. A general computational model for word-form recognition...NUMBER Massachusetts Institute of Technology Artificial Intelligence Laboratory AI-TR 1450 545 Technology Square Cambridge, Massachusetts 02139 9...reader a feel for the workinigs of ANIAR. this chapter will begini withi a very sininpb examl- ple based oni ani artificial tonie laniguage with oiony t

  9. Computational Biology: Modeling Chronic Renal Allograft Injury.

    Science.gov (United States)

    Stegall, Mark D; Borrows, Richard

    2015-01-01

    New approaches are needed to develop more effective interventions to prevent long-term rejection of organ allografts. Computational biology provides a powerful tool to assess the large amount of complex data that is generated in longitudinal studies in this area. This manuscript outlines how our two groups are using mathematical modeling to analyze predictors of graft loss using both clinical and experimental data and how we plan to expand this approach to investigate specific mechanisms of chronic renal allograft injury.

  10. Computational fluid dynamics modelling in cardiovascular medicine.

    Science.gov (United States)

    Morris, Paul D; Narracott, Andrew; von Tengg-Kobligk, Hendrik; Silva Soto, Daniel Alejandro; Hsiao, Sarah; Lungu, Angela; Evans, Paul; Bressloff, Neil W; Lawford, Patricia V; Hose, D Rodney; Gunn, Julian P

    2016-01-01

    This paper reviews the methods, benefits and challenges associated with the adoption and translation of computational fluid dynamics (CFD) modelling within cardiovascular medicine. CFD, a specialist area of mathematics and a branch of fluid mechanics, is used routinely in a diverse range of safety-critical engineering systems, which increasingly is being applied to the cardiovascular system. By facilitating rapid, economical, low-risk prototyping, CFD modelling has already revolutionised research and development of devices such as stents, valve prostheses, and ventricular assist devices. Combined with cardiovascular imaging, CFD simulation enables detailed characterisation of complex physiological pressure and flow fields and the computation of metrics which cannot be directly measured, for example, wall shear stress. CFD models are now being translated into clinical tools for physicians to use across the spectrum of coronary, valvular, congenital, myocardial and peripheral vascular diseases. CFD modelling is apposite for minimally-invasive patient assessment. Patient-specific (incorporating data unique to the individual) and multi-scale (combining models of different length- and time-scales) modelling enables individualised risk prediction and virtual treatment planning. This represents a significant departure from traditional dependence upon registry-based, population-averaged data. Model integration is progressively moving towards 'digital patient' or 'virtual physiological human' representations. When combined with population-scale numerical models, these models have the potential to reduce the cost, time and risk associated with clinical trials. The adoption of CFD modelling signals a new era in cardiovascular medicine. While potentially highly beneficial, a number of academic and commercial groups are addressing the associated methodological, regulatory, education- and service-related challenges.

  11. Adolescence and the reorganization of infant development: a neuro-psychoanalytic model.

    Science.gov (United States)

    Stortelder, Frans; Ploegmakers-Burg, Marian

    2010-01-01

    The psychoanalytic view of adolescence as a phase of turbulence and reorganization occupied a central position in child and adolescent psychiatry until about 1980. The view of adolescence as a silent-transition phase then prevailed and diverged from the psychoanalytic perspective. This article reviews infant and adolescent development using an interdisciplinary, neuro-psychoanalytic model in which psychoanalytic, neurobiological, and developmental perspectives converge and complement each other. Recent empirical research focuses attention on adolescence as a phase in which a far-reaching neurobiological and psychological reorganization takes place. According to the ontogenetic principle of psychoanalysis, the development and organization of the basic psychic functions occur in the first five years of life, while a reorganization takes place in adolescence. Neurobiological research confirms that the basic growth and maturation of the brain occurs in the first five years of life, and that a substantial reorganization in brain development transpires in adolescence. Research also verifies the clinical psychoanalytic concept that neurobiological and psychological maturation in adolescence remain unfinished till approximately age 23. The long-term and late biopsychosocial maturation in adolescence implies that adequate monitoring by parents and school remains necessary. The view that adolescents need to separate, and discover their individuality and independence alone, is unsupported by recent findings. The adolescent must acquire his independence, personal identity, and self-agency ("scaffolding") step by step. It is important that the adolescent knows that his parents are in the background monitoring and intervening as necessary; that he is not entirely alone, adrift and at risk for potential fragmentation. The long-term plasticity of the brain in adolescence implies greater vulnerability for the development of psychopathology, but offers opportunity for

  12. The Effect of Computer Usage in Internet Café on Cigarette Smoking and Alcohol Use among Chinese Adolescents and Youth: A Longitudinal Study

    Directory of Open Access Journals (Sweden)

    Jorge Delva

    2012-02-01

    Full Text Available We used longitudinal data to investigate the relationship between computer use in internet cafés and smoking/drinking behavior among Chinese adolescents and young adults. Data are from two waves of the China Health and Nutrition Survey (2004 and 2006. Fixed effects models were used to examine if changes in internet café use were associated with changes in cigarette smoking and drinking of alcohol. Male café users spent on average 17.3 hours in front of the computer/week. This was associated with an increase in the probability of being a current smoker by 13.3% and with smoking 1.7 more cigarettes. Female café users spent on average 11 hours on the computer/week. This was associated with an increase in the probability of drinking wine and/or liquor by 14.74% and was not associated with smoking. Internet cafés are an important venue by which adolescent and young adults in China are exposed to smoking and drinking. Multi-component interventions are needed ranging from policies regulating cigarette and alcohol availability in these venues to anti-tobacco campaigns aimed at the general population but also at individuals who frequent these establishments.

  13. The effect of computer usage in internet café on cigarette smoking and alcohol use among chinese adolescents and youth: a longitudinal study.

    Science.gov (United States)

    Wu, Liyun; Delva, Jorge

    2012-02-01

    We used longitudinal data to investigate the relationship between computer use in internet cafés and smoking/drinking behavior among Chinese adolescents and young adults. Data are from two waves of the China Health and Nutrition Survey (2004 and 2006). Fixed effects models were used to examine if changes in internet café use were associated with changes in cigarette smoking and drinking of alcohol. Male café users spent on average 17.3 hours in front of the computer/week. This was associated with an increase in the probability of being a current smoker by 13.3% and with smoking 1.7 more cigarettes. Female café users spent on average 11 hours on the computer/week. This was associated with an increase in the probability of drinking wine and/or liquor by 14.74% and was not associated with smoking. Internet cafés are an important venue by which adolescent and young adults in China are exposed to smoking and drinking. Multi-component interventions are needed ranging from policies regulating cigarette and alcohol availability in these venues to anti-tobacco campaigns aimed at the general population but also at individuals who frequent these establishments.

  14. Analytical performance modeling for computer systems

    CERN Document Server

    Tay, Y C

    2013-01-01

    This book is an introduction to analytical performance modeling for computer systems, i.e., writing equations to describe their performance behavior. It is accessible to readers who have taken college-level courses in calculus and probability, networking and operating systems. This is not a training manual for becoming an expert performance analyst. Rather, the objective is to help the reader construct simple models for analyzing and understanding the systems that they are interested in.Describing a complicated system abstractly with mathematical equations requires a careful choice of assumpti

  15. Correspondence and Mediational Properties of the Fishbein Model: An Application to Adolescent Alcohol Use

    Science.gov (United States)

    Schlegel, Ronald P.; And Others

    1977-01-01

    The generalizability of the Fishbein model for behavior prediction was extended to a new field of behavior, alcohol drinking by adolescents. This research investigated the predictive importance of the model's two components, attitudes and normative beliefs. (Editor/RK)

  16. The Effect of Physical Attractiveness of Models on Advertising Effectiveness for Male and Female Adolescents

    Science.gov (United States)

    Tsai, Chia-Ching; Chang, Chih-Hsiang

    2007-01-01

    This study investigates the effect of advertising with physically attractive models on male and female adolescents. The findings suggest that highly attractive models are less effective than those who are normally attractive. Implications of social comparison are discussed.

  17. ADGEN: ADjoint GENerator for computer models

    Energy Technology Data Exchange (ETDEWEB)

    Worley, B.A.; Pin, F.G.; Horwedel, J.E.; Oblow, E.M.

    1989-05-01

    This paper presents the development of a FORTRAN compiler and an associated supporting software library called ADGEN. ADGEN reads FORTRAN models as input and produces and enhanced version of the input model. The enhanced version reproduces the original model calculations but also has the capability to calculate derivatives of model results of interest with respect to any and all of the model data and input parameters. The method for calculating the derivatives and sensitivities is the adjoint method. Partial derivatives are calculated analytically using computer calculus and saved as elements of an adjoint matrix on direct assess storage. The total derivatives are calculated by solving an appropriate adjoint equation. ADGEN is applied to a major computer model of interest to the Low-Level Waste Community, the PRESTO-II model. PRESTO-II sample problem results reveal that ADGEN correctly calculates derivatives of response of interest with respect to 300 parameters. The execution time to create the adjoint matrix is a factor of 45 times the execution time of the reference sample problem. Once this matrix is determined, the derivatives with respect to 3000 parameters are calculated in a factor of 6.8 that of the reference model for each response of interest. For a single 3000 for determining these derivatives by parameter perturbations. The automation of the implementation of the adjoint technique for calculating derivatives and sensitivities eliminates the costly and manpower-intensive task of direct hand-implementation by reprogramming and thus makes the powerful adjoint technique more amenable for use in sensitivity analysis of existing models. 20 refs., 1 fig., 5 tabs.

  18. Computational acoustic modeling of cetacean vocalizations

    Science.gov (United States)

    Gurevich, Michael Dixon

    A framework for computational acoustic modeling of hypothetical vocal production mechanisms in cetaceans is presented. As a specific example, a model of a proposed source in the larynx of odontocetes is developed. Whales and dolphins generate a broad range of vocal sounds, but the exact mechanisms they use are not conclusively understood. In the fifty years since it has become widely accepted that whales can and do make sound, how they do so has remained particularly confounding. Cetaceans' highly divergent respiratory anatomy, along with the difficulty of internal observation during vocalization have contributed to this uncertainty. A variety of acoustical, morphological, ethological and physiological evidence has led to conflicting and often disputed theories of the locations and mechanisms of cetaceans' sound sources. Computational acoustic modeling has been used to create real-time parametric models of musical instruments and the human voice. These techniques can be applied to cetacean vocalizations to help better understand the nature and function of these sounds. Extensive studies of odontocete laryngeal morphology have revealed vocal folds that are consistently similar to a known but poorly understood acoustic source, the ribbon reed. A parametric computational model of the ribbon reed is developed, based on simplified geometrical, mechanical and fluid models drawn from the human voice literature. The physical parameters of the ribbon reed model are then adapted to those of the odontocete larynx. With reasonable estimates of real physical parameters, both the ribbon reed and odontocete larynx models produce sounds that are perceptually similar to their real-world counterparts, and both respond realistically under varying control conditions. Comparisons of acoustic features of the real-world and synthetic systems show a number of consistencies. While this does not on its own prove that either model is conclusively an accurate description of the source, it

  19. Alcohol Consumption Among Scholarized Adolescents: A Socio-Communitarian Model

    Directory of Open Access Journals (Sweden)

    María Elena Villarreal-González

    2010-12-01

    Full Text Available The aim of this study is to analyze the relationships that the individual, family, social and school variables have with the risk of alcohol consumption among adolescents. This is an explanatory causal study. The sample consisted of 1,245 adolescents of both sexes drawn from two secondary level and two pre-university level educational institutions, and were all aged between 12 and 17 years old. Stratified probability sampling was used, taking into account the proportion of students in each grade, level, group and timetable. To analyze the data, a structural equation model was calculated that explained 66% of the variance. The results showed that community social support and family functioning were indirectly related to alcohol consumption. The former was positively and significantly related, through friends’ support and also alcohol use by family and friends, while the latter was related through two paths: firstly, a positive and significant relationship, with family support and alcohol use by family and friends and, secondly, positively through school adjustment and school self-esteem which was negatively related with alcohol consumption. A significant and positive relationship was also observed between family functioning and social support. The results are discussed in terms of the most relevant studies on the subject of this research and the methodological limitations of this study are also considered.

  20. Computer Modeling of Human Delta Opioid Receptor

    Directory of Open Access Journals (Sweden)

    Tatyana Dzimbova

    2013-04-01

    Full Text Available The development of selective agonists of δ-opioid receptor as well as the model of interaction of ligands with this receptor is the subjects of increased interest. In the absence of crystal structures of opioid receptors, 3D homology models with different templates have been reported in the literature. The problem is that these models are not available for widespread use. The aims of our study are: (1 to choose within recently published crystallographic structures templates for homology modeling of the human δ-opioid receptor (DOR; (2 to evaluate the models with different computational tools; and (3 to precise the most reliable model basing on correlation between docking data and in vitro bioassay results. The enkephalin analogues, as ligands used in this study, were previously synthesized by our group and their biological activity was evaluated. Several models of DOR were generated using different templates. All these models were evaluated by PROCHECK and MolProbity and relationship between docking data and in vitro results was determined. The best correlations received for the tested models of DOR were found between efficacy (erel of the compounds, calculated from in vitro experiments and Fitness scoring function from docking studies. New model of DOR was generated and evaluated by different approaches. This model has good GA341 value (0.99 from MODELLER, good values from PROCHECK (92.6% of most favored regions and MolProbity (99.5% of favored regions. Scoring function correlates (Pearson r = -0.7368, p-value = 0.0097 with erel of a series of enkephalin analogues, calculated from in vitro experiments. So, this investigation allows suggesting a reliable model of DOR. Newly generated model of DOR receptor could be used further for in silico experiments and it will give possibility for faster and more correct design of selective and effective ligands for δ-opioid receptor.

  1. Computational Design Modelling : Proceedings of the Design Modelling Symposium

    CERN Document Server

    Kilian, Axel; Palz, Norbert; Scheurer, Fabian

    2012-01-01

    This book publishes the peer-reviewed proceeding of the third Design Modeling Symposium Berlin . The conference constitutes a platform for dialogue on experimental practice and research within the field of computationally informed architectural design. More than 60 leading experts the computational processes within the field of computationally informed architectural design to develop a broader and less exotic building practice that bears more subtle but powerful traces of the complex tool set and approaches we have developed and studied over recent years. The outcome are new strategies for a reasonable and innovative implementation of digital potential in truly innovative and radical design guided by both responsibility towards processes and the consequences they initiate.

  2. Interlanguages and synchronic models of computation

    CERN Document Server

    Berka, Alexander Victor

    2010-01-01

    A novel language system has given rise to promising alternatives to standard formal and processor network models of computation. An interstring linked with a abstract machine environment, shares sub-expressions, transfers data, and spatially allocates resources for the parallel evaluation of dataflow. Formal models called the a-Ram family are introduced, designed to support interstring programming languages (interlanguages). Distinct from dataflow, graph rewriting, and FPGA models, a-Ram instructions are bit level and execute in situ. They support sequential and parallel languages without the space/time overheads associated with the Turing Machine and l-calculus, enabling massive programs to be simulated. The devices of one a-Ram model, called the Synchronic A-Ram, are fully connected and simpler than FPGA LUT's. A compiler for an interlanguage called Space, has been developed for the Synchronic A-Ram. Space is MIMD. strictly typed, and deterministic. Barring memory allocation and compilation, modules are ref...

  3. Computational Modeling of Large Wildfires: A Roadmap

    KAUST Repository

    Coen, Janice L.

    2010-08-01

    Wildland fire behavior, particularly that of large, uncontrolled wildfires, has not been well understood or predicted. Our methodology to simulate this phenomenon uses high-resolution dynamic models made of numerical weather prediction (NWP) models coupled to fire behavior models to simulate fire behavior. NWP models are capable of modeling very high resolution (< 100 m) atmospheric flows. The wildland fire component is based upon semi-empirical formulas for fireline rate of spread, post-frontal heat release, and a canopy fire. The fire behavior is coupled to the atmospheric model such that low level winds drive the spread of the surface fire, which in turn releases sensible heat, latent heat, and smoke fluxes into the lower atmosphere, feeding back to affect the winds directing the fire. These coupled dynamic models capture the rapid spread downwind, flank runs up canyons, bifurcations of the fire into two heads, and rough agreement in area, shape, and direction of spread at periods for which fire location data is available. Yet, intriguing computational science questions arise in applying such models in a predictive manner, including physical processes that span a vast range of scales, processes such as spotting that cannot be modeled deterministically, estimating the consequences of uncertainty, the efforts to steer simulations with field data ("data assimilation"), lingering issues with short term forecasting of weather that may show skill only on the order of a few hours, and the difficulty of gathering pertinent data for verification and initialization in a dangerous environment. © 2010 IEEE.

  4. A neural computational model of incentive salience.

    Science.gov (United States)

    Zhang, Jun; Berridge, Kent C; Tindell, Amy J; Smith, Kyle S; Aldridge, J Wayne

    2009-07-01

    Incentive salience is a motivational property with 'magnet-like' qualities. When attributed to reward-predicting stimuli (cues), incentive salience triggers a pulse of 'wanting' and an individual is pulled toward the cues and reward. A key computational question is how incentive salience is generated during a cue re-encounter, which combines both learning and the state of limbic brain mechanisms. Learning processes, such as temporal-difference models, provide one way for stimuli to acquire cached predictive values of rewards. However, empirical data show that subsequent incentive values are also modulated on the fly by dynamic fluctuation in physiological states, altering cached values in ways requiring additional motivation mechanisms. Dynamic modulation of incentive salience for a Pavlovian conditioned stimulus (CS or cue) occurs during certain states, without necessarily requiring (re)learning about the cue. In some cases, dynamic modulation of cue value occurs during states that are quite novel, never having been experienced before, and even prior to experience of the associated unconditioned reward in the new state. Such cases can include novel drug-induced mesolimbic activation and addictive incentive-sensitization, as well as natural appetite states such as salt appetite. Dynamic enhancement specifically raises the incentive salience of an appropriate CS, without necessarily changing that of other CSs. Here we suggest a new computational model that modulates incentive salience by integrating changing physiological states with prior learning. We support the model with behavioral and neurobiological data from empirical tests that demonstrate dynamic elevations in cue-triggered motivation (involving natural salt appetite, and drug-induced intoxication and sensitization). Our data call for a dynamic model of incentive salience, such as presented here. Computational models can adequately capture fluctuations in cue-triggered 'wanting' only by incorporating

  5. A neural computational model of incentive salience.

    Directory of Open Access Journals (Sweden)

    Jun Zhang

    2009-07-01

    Full Text Available Incentive salience is a motivational property with 'magnet-like' qualities. When attributed to reward-predicting stimuli (cues, incentive salience triggers a pulse of 'wanting' and an individual is pulled toward the cues and reward. A key computational question is how incentive salience is generated during a cue re-encounter, which combines both learning and the state of limbic brain mechanisms. Learning processes, such as temporal-difference models, provide one way for stimuli to acquire cached predictive values of rewards. However, empirical data show that subsequent incentive values are also modulated on the fly by dynamic fluctuation in physiological states, altering cached values in ways requiring additional motivation mechanisms. Dynamic modulation of incentive salience for a Pavlovian conditioned stimulus (CS or cue occurs during certain states, without necessarily requiring (relearning about the cue. In some cases, dynamic modulation of cue value occurs during states that are quite novel, never having been experienced before, and even prior to experience of the associated unconditioned reward in the new state. Such cases can include novel drug-induced mesolimbic activation and addictive incentive-sensitization, as well as natural appetite states such as salt appetite. Dynamic enhancement specifically raises the incentive salience of an appropriate CS, without necessarily changing that of other CSs. Here we suggest a new computational model that modulates incentive salience by integrating changing physiological states with prior learning. We support the model with behavioral and neurobiological data from empirical tests that demonstrate dynamic elevations in cue-triggered motivation (involving natural salt appetite, and drug-induced intoxication and sensitization. Our data call for a dynamic model of incentive salience, such as presented here. Computational models can adequately capture fluctuations in cue-triggered 'wanting' only by

  6. Violent Victimization and Perpetration during Adolescence: Developmental Stage Dependent Ecological Models

    Science.gov (United States)

    Matjasko, Jennifer L.; Needham, Belinda L.; Grunden, Leslie N.; Farb, Amy Feldman

    2010-01-01

    Using a variant of the ecological-transactional model and developmental theories of delinquency on a nationally representative sample of adolescents, the current study explored the ecological predictors of violent victimization, perpetration, and both for three different developmental stages during adolescence. We examined the relative influence…

  7. Talking "Privilege": Barriers to Musical Attainment in Adolescents' Talk of Musical Role Models

    Science.gov (United States)

    Ivaldi, Antonia; O'Neill, Susan

    2009-01-01

    Using a discursive approach, this study explores the ways that adolescents construct the notion of social status and "being privileged" through their talk about musician role models. Drawing on social identity theory (see Tajfel, 1978), we examined how adolescents moved between the relational "in" and "out" groups of being privileged versus being…

  8. Perceived Stress and Wellness in Early Adolescents Using the Neuman Systems Model

    Science.gov (United States)

    Yarcheski, Thomas J.; Mahon, Noreen E.; Yarcheski, Adela; Hanks, Michele M.

    2010-01-01

    The purpose of this study was to examine the relationship between perceived stress and wellness in early adolescents and to test primary appraisal as a mediator of this relationship using the Neuman Systems Model as the primary framework. The sample consisted of 144 adolescents, ages 12-14, who responded to instruments measuring perceived stress,…

  9. Temperament Pathways to Childhood Disruptive Behavior and Adolescent Substance Abuse: Testing a Cascade Model

    Science.gov (United States)

    Martel, Michelle M.; Pierce, Laura; Nigg, Joel T.; Jester, Jennifer M.; Adams, Kenneth; Puttler, Leon I.; Buu, Anne; Fitzgerald, Hiram; Zucker, Robert A.

    2009-01-01

    Temperament traits may increase risk for developmental psychopathology like Attention-Deficit/Hyperactivity Disorder (ADHD) and disruptive behaviors during childhood, as well as predisposing to substance abuse during adolescence. In the current study, a cascade model of trait pathways to adolescent substance abuse was examined. Component…

  10. Self-Esteem and Delinquency in South Korean Adolescents: Latent Growth Modeling

    Science.gov (United States)

    Lee, Kyungeun; Lee, Julie

    2012-01-01

    This study examined the inter-related development of self-esteem and delinquency across three years. Participants were 3449 Korean high school adolescents (age M = 15.8, SD = 0.42, 1725 boys, 1724 girls) from Korea Youth Panel Study (KYPS), in 2005-2007, nationally representative of Korean adolescents. Latent growth modeling was employed for…

  11. A Qualitative Study of Parental Modeling and Social Support for Physical Activity in Underserved Adolescents

    Science.gov (United States)

    Wright, Marcie S.; Wilson, Dawn K.; Griffin, Sarah; Evans, Alexandra

    2010-01-01

    This study obtained qualitative data to assess how parental role modeling and parental social support influence physical activity in underserved (minority, low-income) adolescents. Fifty-two adolescents (22 males, 30 females; ages 10-14 years, 85% African-American) participated in a focus group (6-10 per group, same gender). Focus groups were…

  12. An Adolescent Nutrition Learning Model to Facilitate Behavior Change in Overweight Teens

    Science.gov (United States)

    Young, Kimberly J.; Ramsay, Samantha A.; Holyoke, Laura B.

    2016-01-01

    Understanding the process by which adolescents learn about nutrition is necessary for developing tailored education that leads to sustainable behavior change. Teens aged 15-17 participating in an obesity prevention program were interviewed. From the data, three themes emerged and informed development of an adolescent nutrition learning model. The…

  13. The Cognitive Processes Associated with Occupational/Career Indecision: A Model for Gifted Adolescents

    Science.gov (United States)

    Jung, Jae Yup

    2013-01-01

    This study developed and tested a new model of the cognitive processes associated with occupational/career indecision for gifted adolescents. A survey instrument with rigorous psychometric properties, developed from a number of existing instruments, was administered to a sample of 687 adolescents attending three academically selective high schools…

  14. Using the Integrative Model to Explain How Exposure to Sexual Media Content Influences Adolescent Sexual Behavior

    Science.gov (United States)

    Bleakley, Amy; Hennessy, Michael; Fishbein, Martin; Jordan, Amy

    2011-01-01

    Published research demonstrates an association between exposure to media sexual content and a variety of sex-related outcomes for adolescents. What is not known is the mechanism through which sexual content produces this "media effect" on adolescent beliefs, attitudes, and behavior. Using the Integrative Model of Behavioral Prediction, this…

  15. Multivariate Models of Parent-Late Adolescent Gender Dyads: The Importance of Parenting Processes in Predicting Adjustment

    Science.gov (United States)

    McKinney, Cliff; Renk, Kimberly

    2008-01-01

    Although parent-adolescent interactions have been examined, relevant variables have not been integrated into a multivariate model. As a result, this study examined a multivariate model of parent-late adolescent gender dyads in an attempt to capture important predictors in late adolescents' important and unique transition to adulthood. The sample…

  16. DYNAMIC TASK PARTITIONING MODEL IN PARALLEL COMPUTING

    Directory of Open Access Journals (Sweden)

    Javed Ali

    2012-04-01

    Full Text Available Parallel computing systems compose task partitioning strategies in a true multiprocessing manner. Such systems share the algorithm and processing unit as computing resources which leads to highly inter process communications capabilities. The main part of the proposed algorithm is resource management unit which performs task partitioning and co-scheduling .In this paper, we present a technique for integrated task partitioning and co-scheduling on the privately owned network. We focus on real-time and non preemptive systems. A large variety of experiments have been conducted on the proposed algorithm using synthetic and real tasks. Goal of computation model is to provide a realistic representation of the costs of programming The results show the benefit of the task partitioning. The main characteristics of our method are optimal scheduling and strong link between partitioning, scheduling and communication. Some important models for task partitioning are also discussed in the paper. We target the algorithm for task partitioning which improve the inter process communication between the tasks and use the recourses of the system in the efficient manner. The proposed algorithm contributes the inter-process communication cost minimization amongst the executing processes.

  17. Computer Generated Cardiac Model For Nuclear Medicine

    Science.gov (United States)

    Hills, John F.; Miller, Tom R.

    1981-07-01

    A computer generated mathematical model of a thallium-201 myocardial image is described which is based on realistic geometric and physiological assumptions. The left ventricle is represented by an ellipsoid truncated by aortic and mitral valve planes. Initially, an image of a motionless left ventricle is calculated with the location, size, and relative activity of perfusion defects selected by the designer. The calculation includes corrections for photon attenuation by overlying structures and the relative distribution of activity within the tissues. Motion of the ventricular walls is simulated either by a weighted sum of images at different stages in the cardiac cycle or by a blurring function whose width varies with position. Camera and collimator blurring are estimated by the MTF of the system measured at a representative depth in a phantom. Statistical noise is added using a Poisson random number generator. The usefulness of this model is due to two factors: the a priori characterization of location and extent of perfusion defects and the strong visual similarity of the images to actual clinical studies. These properties should permit systematic evaluation of image processing algorithms using this model. The principles employed in developing this cardiac image model can readily be applied to the simulation of other nuclear medicine studies and to other medical imaging modalities including computed tomography, ultrasound, and digital radiography.

  18. Computer model of tetrahedral amorphous diamond

    Science.gov (United States)

    Djordjević, B. R.; Thorpe, M. F.; Wooten, F.

    1995-08-01

    We computer generate a model of amorphous diamond using the Wooten-Weaire method, with fourfold coordination everywhere. We investigate two models: one where four-membered rings are allowed and the other where the four-membered rings are forbidden; each model consisting of 4096 atoms. Starting from the perfect diamond crystalline structure, we first randomize the structure by introducing disorder through random bond switches at a sufficiently high temperature. Subsequently, the temperature is reduced in stages, and the topological and geometrical relaxation of the structure takes place using the Keating potential. After a long annealing process, a random network of comparatively low energy is obtained. We calculate the pair distribution function, mean bond angle, rms angular deviation, rms bond length, rms bond-length deviation, and ring statistics for the final relaxed structures. We minimize the total strain energy by adjusting the density of the sample. We compare our results with similar computer-generated models for amorphous silicon, and with experimental measurement of the structure factor for (predominantly tetrahedral) amorphous carbon.

  19. Computer modeling for optimal placement of gloveboxes

    Energy Technology Data Exchange (ETDEWEB)

    Hench, K.W.; Olivas, J.D. [Los Alamos National Lab., NM (United States); Finch, P.R. [New Mexico State Univ., Las Cruces, NM (United States)

    1997-08-01

    Reduction of the nuclear weapons stockpile and the general downsizing of the nuclear weapons complex has presented challenges for Los Alamos. One is to design an optimized fabrication facility to manufacture nuclear weapon primary components (pits) in an environment of intense regulation and shrinking budgets. Historically, the location of gloveboxes in a processing area has been determined without benefit of industrial engineering studies to ascertain the optimal arrangement. The opportunity exists for substantial cost savings and increased process efficiency through careful study and optimization of the proposed layout by constructing a computer model of the fabrication process. This paper presents an integrative two- stage approach to modeling the casting operation for pit fabrication. The first stage uses a mathematical technique for the formulation of the facility layout problem; the solution procedure uses an evolutionary heuristic technique. The best solutions to the layout problem are used as input to the second stage - a computer simulation model that assesses the impact of competing layouts on operational performance. The focus of the simulation model is to determine the layout that minimizes personnel radiation exposures and nuclear material movement, and maximizes the utilization of capacity for finished units.

  20. COMMON PHASES OF COMPUTER FORENSICS INVESTIGATION MODELS

    Directory of Open Access Journals (Sweden)

    Yunus Yusoff

    2011-06-01

    Full Text Available The increasing criminal activities using digital information as the means or targets warrant for a structured manner in dealing with them. Since 1984 when a formalized process been introduced, a great number of new and improved computer forensic investigation processes have been developed. In this paper, we reviewed a few selected investigation processes that have been produced throughout the yearsand then identified the commonly shared processes. Hopefully, with the identification of the commonly shard process, it would make it easier for the new users to understand the processes and also to serve as the basic underlying concept for the development of a new set of processes. Based on the commonly shared processes, we proposed a generic computer forensics investigation model, known as GCFIM.

  1. Musculoskeletal symptoms and computer use among Finnish adolescents - pain intensity and inconvenience to everyday life: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Hakala Paula T

    2012-03-01

    Full Text Available Abstract Background Musculoskeletal symptoms among adolescents are related to the time spent using a computer, but little is known about the seriousness of the symptoms or how much they affect everyday life. The purpose of the present study was to examine the intensity of musculoskeletal pain and level of inconvenience to everyday life, in relation to time spent using a computer. Methods In a survey, 436 school children (12 to 13 and 15 to 16 years of age, answered a questionnaire on musculoskeletal and computer-associated musculoskeletal symptoms in neck-shoulder, low back, head, eyes, hands, and fingers or wrists. Pain intensity (computer-associated symptoms and inconvenience to everyday life (musculoskeletal symptoms were measured using a visual analogue scale. Based on the frequency and intensity, three categories were formed to classify pain at each anatomic site: none, mild, and moderate/severe. The association with time spent using the computer was analyzed by multinomial logistic regression. Results Moderate/severe pain intensity was most often reported in the neck-shoulders (21%; head (20%; and eyes (14%; and moderate/severe inconvenience to everyday life was most often reported due to head (29%, neck-shoulders (21%, and low back (16% pain. Compared with those using the computer less than 3.6 hours/week, computer use of ≥ 14 hours/week, was associated with moderate/severe increase in computer-associated musculoskeletal pain at all anatomic sites (odds ratio [OR] = 2.9-4.4, and moderate/severe inconvenience to everyday life due to low back (OR = 2.5 and head (OR = 2.0 pain. Conclusions Musculoskeletal symptoms causing moderate/severe pain and inconvenience to everyday life are common among adolescent computer users. Daily computer use of 2 hours or more increases the risk for pain at most anatomic sites.

  2. 40 CFR 194.23 - Models and computer codes.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Models and computer codes. 194.23... General Requirements § 194.23 Models and computer codes. (a) Any compliance application shall include: (1... obtain stable solutions; (iv) Computer models accurately implement the numerical models; i.e.,...

  3. Computer model for analyzing sodium cold traps

    Energy Technology Data Exchange (ETDEWEB)

    McPheeters, C C; Raue, D J

    1983-05-01

    A computer model was developed to simulate the processes that occur in sodium cold traps. The Model for Analyzing Sodium Cold Traps (MASCOT) simulates any desired configuration of mesh arrangements and dimensions and calculates pressure drops and flow distributions, temperature profiles, impurity concentration profiles, and impurity mass distributions. The calculated pressure drop as a function of impurity mass content determines the capacity of the cold trap. The accuracy of the model was checked by comparing calculated mass distributions with experimentally determined mass distributions from literature publications and with results from our own cold trap experiments. The comparisons were excellent in all cases. A parametric study was performed to determine which design variables are most important in maximizing cold trap capacity.

  4. A Graph Model for Imperative Computation

    CERN Document Server

    McCusker, Guy

    2009-01-01

    Scott's graph model is a lambda-algebra based on the observation that continuous endofunctions on the lattice of sets of natural numbers can be represented via their graphs. A graph is a relation mapping finite sets of input values to output values. We consider a similar model based on relations whose input values are finite sequences rather than sets. This alteration means that we are taking into account the order in which observations are made. This new notion of graph gives rise to a model of affine lambda-calculus that admits an interpretation of imperative constructs including variable assignment, dereferencing and allocation. Extending this untyped model, we construct a category that provides a model of typed higher-order imperative computation with an affine type system. An appropriate language of this kind is Reynolds's Syntactic Control of Interference. Our model turns out to be fully abstract for this language. At a concrete level, it is the same as Reddy's object spaces model, which was the first "...

  5. Modelling of data uncertainties on hybrid computers

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Anke (ed.)

    2016-06-15

    The codes d{sup 3}f and r{sup 3}t are well established for modelling density-driven flow and nuclide transport in the far field of repositories for hazardous material in deep geological formations. They are applicable in porous media as well as in fractured rock or mudstone, for modelling salt- and heat transport as well as a free groundwater surface. Development of the basic framework of d{sup 3}f and r{sup 3}t had begun more than 20 years ago. Since that time significant advancements took place in the requirements for safety assessment as well as for computer hardware development. The period of safety assessment for a repository of high-level radioactive waste was extended to 1 million years, and the complexity of the models is steadily growing. Concurrently, the demands on accuracy increase. Additionally, model and parameter uncertainties become more and more important for an increased understanding of prediction reliability. All this leads to a growing demand for computational power that requires a considerable software speed-up. An effective way to achieve this is the use of modern, hybrid computer architectures which requires basically the set-up of new data structures and a corresponding code revision but offers a potential speed-up by several orders of magnitude. The original codes d{sup 3}f and r{sup 3}t were applications of the software platform UG /BAS 94/ whose development had begun in the early nineteennineties. However, UG had recently been advanced to the C++ based, substantially revised version UG4 /VOG 13/. To benefit also in the future from state-of-the-art numerical algorithms and to use hybrid computer architectures, the codes d{sup 3}f and r{sup 3}t were transferred to this new code platform. Making use of the fact that coupling between different sets of equations is natively supported in UG4, d{sup 3}f and r{sup 3}t were combined to one conjoint code d{sup 3}f++. A direct estimation of uncertainties for complex groundwater flow models with the

  6. Computational modeling of Li-ion batteries

    Science.gov (United States)

    Grazioli, D.; Magri, M.; Salvadori, A.

    2016-12-01

    This review focuses on energy storage materials modeling, with particular emphasis on Li-ion batteries. Theoretical and computational analyses not only provide a better understanding of the intimate behavior of actual batteries under operational and extreme conditions, but they may tailor new materials and shape new architectures in a complementary way to experimental approaches. Modeling can therefore play a very valuable role in the design and lifetime prediction of energy storage materials and devices. Batteries are inherently multi-scale, in space and time. The macro-structural characteristic lengths (the thickness of a single cell, for instance) are order of magnitudes larger than the particles that form the microstructure of the porous electrodes, which in turn are scale-separated from interface layers at which atomistic intercalations occur. Multi-physics modeling concepts, methodologies, and simulations at different scales, as well as scale transition strategies proposed in the recent literature are here revised. Finally, computational challenges toward the next generation of Li-ion batteries are discussed.

  7. Modeling Reality - How Computers Mirror Life

    Science.gov (United States)

    Bialynicki-Birula, Iwo; Bialynicka-Birula, Iwona

    2005-01-01

    The bookModeling Reality covers a wide range of fascinating subjects, accessible to anyone who wants to learn about the use of computer modeling to solve a diverse range of problems, but who does not possess a specialized training in mathematics or computer science. The material presented is pitched at the level of high-school graduates, even though it covers some advanced topics (cellular automata, Shannon's measure of information, deterministic chaos, fractals, game theory, neural networks, genetic algorithms, and Turing machines). These advanced topics are explained in terms of well known simple concepts: Cellular automata - Game of Life, Shannon's formula - Game of twenty questions, Game theory - Television quiz, etc. The book is unique in explaining in a straightforward, yet complete, fashion many important ideas, related to various models of reality and their applications. Twenty-five programs, written especially for this book, are provided on an accompanying CD. They greatly enhance its pedagogical value and make learning of even the more complex topics an enjoyable pleasure.

  8. Computational modeling of Li-ion batteries

    Science.gov (United States)

    Grazioli, D.; Magri, M.; Salvadori, A.

    2016-08-01

    This review focuses on energy storage materials modeling, with particular emphasis on Li-ion batteries. Theoretical and computational analyses not only provide a better understanding of the intimate behavior of actual batteries under operational and extreme conditions, but they may tailor new materials and shape new architectures in a complementary way to experimental approaches. Modeling can therefore play a very valuable role in the design and lifetime prediction of energy storage materials and devices. Batteries are inherently multi-scale, in space and time. The macro-structural characteristic lengths (the thickness of a single cell, for instance) are order of magnitudes larger than the particles that form the microstructure of the porous electrodes, which in turn are scale-separated from interface layers at which atomistic intercalations occur. Multi-physics modeling concepts, methodologies, and simulations at different scales, as well as scale transition strategies proposed in the recent literature are here revised. Finally, computational challenges toward the next generation of Li-ion batteries are discussed.

  9. Computer-aided modeling framework – a generic modeling template

    DEFF Research Database (Denmark)

    Fedorova, Marina; Sin, Gürkan; Gani, Rafiqul

    This work focuses on the development of a computer-aided modeling framework. The framework is a knowledge-based system that is built on a generic modeling language and structured on workflows for different modeling tasks. The overall objective is to support model developers and users to generate...... and test models systematically, efficiently and reliably. In this way, development of products and processes can be made faster, cheaper and more efficient. In this contribution, as part of the framework, a generic modeling template for the systematic derivation of problem specific models is presented....... The application of the modeling template is highlighted with a case study related to the modeling of a catalytic membrane reactor coupling dehydrogenation of ethylbenzene with hydrogenation of nitrobenzene...

  10. Optimization and mathematical modeling in computer architecture

    CERN Document Server

    Sankaralingam, Karu; Nowatzki, Tony

    2013-01-01

    In this book we give an overview of modeling techniques used to describe computer systems to mathematical optimization tools. We give a brief introduction to various classes of mathematical optimization frameworks with special focus on mixed integer linear programming which provides a good balance between solver time and expressiveness. We present four detailed case studies -- instruction set customization, data center resource management, spatial architecture scheduling, and resource allocation in tiled architectures -- showing how MILP can be used and quantifying by how much it outperforms t

  11. Dynamical Models for Computer Viruses Propagation

    Directory of Open Access Journals (Sweden)

    José R. C. Piqueira

    2008-01-01

    Full Text Available Nowadays, digital computer systems and networks are the main engineering tools, being used in planning, design, operation, and control of all sizes of building, transportation, machinery, business, and life maintaining devices. Consequently, computer viruses became one of the most important sources of uncertainty, contributing to decrease the reliability of vital activities. A lot of antivirus programs have been developed, but they are limited to detecting and removing infections, based on previous knowledge of the virus code. In spite of having good adaptation capability, these programs work just as vaccines against diseases and are not able to prevent new infections based on the network state. Here, a trial on modeling computer viruses propagation dynamics relates it to other notable events occurring in the network permitting to establish preventive policies in the network management. Data from three different viruses are collected in the Internet and two different identification techniques, autoregressive and Fourier analyses, are applied showing that it is possible to forecast the dynamics of a new virus propagation by using the data collected from other viruses that formerly infected the network.

  12. Computational social dynamic modeling of group recruitment.

    Energy Technology Data Exchange (ETDEWEB)

    Berry, Nina M.; Lee, Marinna; Pickett, Marc; Turnley, Jessica Glicken (Sandia National Laboratories, Albuquerque, NM); Smrcka, Julianne D. (Sandia National Laboratories, Albuquerque, NM); Ko, Teresa H.; Moy, Timothy David (Sandia National Laboratories, Albuquerque, NM); Wu, Benjamin C.

    2004-01-01

    The Seldon software toolkit combines concepts from agent-based modeling and social science to create a computationally social dynamic model for group recruitment. The underlying recruitment model is based on a unique three-level hybrid agent-based architecture that contains simple agents (level one), abstract agents (level two), and cognitive agents (level three). This uniqueness of this architecture begins with abstract agents that permit the model to include social concepts (gang) or institutional concepts (school) into a typical software simulation environment. The future addition of cognitive agents to the recruitment model will provide a unique entity that does not exist in any agent-based modeling toolkits to date. We use social networks to provide an integrated mesh within and between the different levels. This Java based toolkit is used to analyze different social concepts based on initialization input from the user. The input alters a set of parameters used to influence the values associated with the simple agents, abstract agents, and the interactions (simple agent-simple agent or simple agent-abstract agent) between these entities. The results of phase-1 Seldon toolkit provide insight into how certain social concepts apply to different scenario development for inner city gang recruitment.

  13. Analysis of a Model for Computer Virus Transmission

    Directory of Open Access Journals (Sweden)

    Peng Qin

    2015-01-01

    Full Text Available Computer viruses remain a significant threat to computer networks. In this paper, the incorporation of new computers to the network and the removing of old computers from the network are considered. Meanwhile, the computers are equipped with antivirus software on the computer network. The computer virus model is established. Through the analysis of the model, disease-free and endemic equilibrium points are calculated. The stability conditions of the equilibria are derived. To illustrate our theoretical analysis, some numerical simulations are also included. The results provide a theoretical basis to control the spread of computer virus.

  14. Computational models of intergroup competition and warfare.

    Energy Technology Data Exchange (ETDEWEB)

    Letendre, Kenneth (University of New Mexico); Abbott, Robert G.

    2011-11-01

    This document reports on the research of Kenneth Letendre, the recipient of a Sandia Graduate Research Fellowship at the University of New Mexico. Warfare is an extreme form of intergroup competition in which individuals make extreme sacrifices for the benefit of their nation or other group to which they belong. Among animals, limited, non-lethal competition is the norm. It is not fully understood what factors lead to warfare. We studied the global variation in the frequency of civil conflict among countries of the world, and its positive association with variation in the intensity of infectious disease. We demonstrated that the burden of human infectious disease importantly predicts the frequency of civil conflict and tested a causal model for this association based on the parasite-stress theory of sociality. We also investigated the organization of social foraging by colonies of harvester ants in the genus Pogonomyrmex, using both field studies and computer models.

  15. Computer modeling of thermoelectric generator performance

    Science.gov (United States)

    Chmielewski, A. B.; Shields, V.

    1982-01-01

    Features of the DEGRA 2 computer code for simulating the operations of a spacecraft thermoelectric generator are described. The code models the physical processes occurring during operation. Input variables include the thermoelectric couple geometry and composition, the thermoelectric materials' properties, interfaces and insulation in the thermopile, the heat source characteristics, mission trajectory, and generator electrical requirements. Time steps can be specified and sublimation of the leg and hot shoe is accounted for, as are shorts between legs. Calculations are performed for conduction, Peltier, Thomson, and Joule heating, the cold junction can be adjusted for solar radition, and the legs of the thermoelectric couple are segmented to enhance the approximation accuracy. A trial run covering 18 couple modules yielded data with 0.3% accuracy with regard to test data. The model has been successful with selenide materials, SiGe, and SiN4, with output of all critical operational variables.

  16. A computational model of motor neuron degeneration.

    Science.gov (United States)

    Le Masson, Gwendal; Przedborski, Serge; Abbott, L F

    2014-08-20

    To explore the link between bioenergetics and motor neuron degeneration, we used a computational model in which detailed morphology and ion conductance are paired with intracellular ATP production and consumption. We found that reduced ATP availability increases the metabolic cost of a single action potential and disrupts K+/Na+ homeostasis, resulting in a chronic depolarization. The magnitude of the ATP shortage at which this ionic instability occurs depends on the morphology and intrinsic conductance characteristic of the neuron. If ATP shortage is confined to the distal part of the axon, the ensuing local ionic instability eventually spreads to the whole neuron and involves fasciculation-like spiking events. A shortage of ATP also causes a rise in intracellular calcium. Our modeling work supports the notion that mitochondrial dysfunction can account for salient features of the paralytic disorder amyotrophic lateral sclerosis, including motor neuron hyperexcitability, fasciculation, and differential vulnerability of motor neuron subpopulations.

  17. Direct modeling for computational fluid dynamics

    Science.gov (United States)

    Xu, Kun

    2015-06-01

    All fluid dynamic equations are valid under their modeling scales, such as the particle mean free path and mean collision time scale of the Boltzmann equation and the hydrodynamic scale of the Navier-Stokes (NS) equations. The current computational fluid dynamics (CFD) focuses on the numerical solution of partial differential equations (PDEs), and its aim is to get the accurate solution of these governing equations. Under such a CFD practice, it is hard to develop a unified scheme that covers flow physics from kinetic to hydrodynamic scales continuously because there is no such governing equation which could make a smooth transition from the Boltzmann to the NS modeling. The study of fluid dynamics needs to go beyond the traditional numerical partial differential equations. The emerging engineering applications, such as air-vehicle design for near-space flight and flow and heat transfer in micro-devices, do require further expansion of the concept of gas dynamics to a larger domain of physical reality, rather than the traditional distinguishable governing equations. At the current stage, the non-equilibrium flow physics has not yet been well explored or clearly understood due to the lack of appropriate tools. Unfortunately, under the current numerical PDE approach, it is hard to develop such a meaningful tool due to the absence of valid PDEs. In order to construct multiscale and multiphysics simulation methods similar to the modeling process of constructing the Boltzmann or the NS governing equations, the development of a numerical algorithm should be based on the first principle of physical modeling. In this paper, instead of following the traditional numerical PDE path, we introduce direct modeling as a principle for CFD algorithm development. Since all computations are conducted in a discretized space with limited cell resolution, the flow physics to be modeled has to be done in the mesh size and time step scales. Here, the CFD is more or less a direct

  18. Stochastic linear programming models, theory, and computation

    CERN Document Server

    Kall, Peter

    2011-01-01

    This new edition of Stochastic Linear Programming: Models, Theory and Computation has been brought completely up to date, either dealing with or at least referring to new material on models and methods, including DEA with stochastic outputs modeled via constraints on special risk functions (generalizing chance constraints, ICC’s and CVaR constraints), material on Sharpe-ratio, and Asset Liability Management models involving CVaR in a multi-stage setup. To facilitate use as a text, exercises are included throughout the book, and web access is provided to a student version of the authors’ SLP-IOR software. Additionally, the authors have updated the Guide to Available Software, and they have included newer algorithms and modeling systems for SLP. The book is thus suitable as a text for advanced courses in stochastic optimization, and as a reference to the field. From Reviews of the First Edition: "The book presents a comprehensive study of stochastic linear optimization problems and their applications. … T...

  19. Heterogeneity and Change in the Patterning of Adolescents' Perceptions of the Legitimacy of Parental Authority: A Latent Transition Model

    Science.gov (United States)

    Cumsille, Patricio; Darling, Nancy; Flaherty, Brian; Martinez, Maria Loreto

    2009-01-01

    Changes in the patterning of adolescents' beliefs about the legitimate domains of parental authority were modeled in 2,611 Chilean adolescents, 11-16 years old. Transitions in adolescents' belief patterns were studied over 3 years. Latent transition analysis (LTA) revealed 3 distinct patterns of beliefs--"parent control," "shared control," and…

  20. Satisfaction of Needs and Determining of Life Goals: A Model of Subjective Well-Being for Adolescents in High School

    Science.gov (United States)

    Eryilmaz, Ali

    2011-01-01

    The aim of this study is to develop and test a subjective well-being model for adolescents in high school. A total of 326 adolescents in high school (176 female and 150 male) participated in this study. The data was collected by using the general needs satisfaction questionnaire, which is for the adolescents' subjective well-being, and determining…

  1. Statistics, Computation, and Modeling in Cosmology

    Science.gov (United States)

    Jewell, Jeff; Guiness, Joe; SAMSI 2016 Working Group in Cosmology

    2017-01-01

    Current and future ground and space based missions are designed to not only detect, but map out with increasing precision, details of the universe in its infancy to the present-day. As a result we are faced with the challenge of analyzing and interpreting observations from a wide variety of instruments to form a coherent view of the universe. Finding solutions to a broad range of challenging inference problems in cosmology is one of the goals of the “Statistics, Computation, and Modeling in Cosmology” workings groups, formed as part of the year long program on ‘Statistical, Mathematical, and Computational Methods for Astronomy’, hosted by the Statistical and Applied Mathematical Sciences Institute (SAMSI), a National Science Foundation funded institute. Two application areas have emerged for focused development in the cosmology working group involving advanced algorithmic implementations of exact Bayesian inference for the Cosmic Microwave Background, and statistical modeling of galaxy formation. The former includes study and development of advanced Markov Chain Monte Carlo algorithms designed to confront challenging inference problems including inference for spatial Gaussian random fields in the presence of sources of galactic emission (an example of a source separation problem). Extending these methods to future redshift survey data probing the nonlinear regime of large scale structure formation is also included in the working group activities. In addition, the working group is also focused on the study of ‘Galacticus’, a galaxy formation model applied to dark matter-only cosmological N-body simulations operating on time-dependent halo merger trees. The working group is interested in calibrating the Galacticus model to match statistics of galaxy survey observations; specifically stellar mass functions, luminosity functions, and color-color diagrams. The group will use subsampling approaches and fractional factorial designs to statistically and

  2. A Process Model of Parenting and Adolescents' Friendship Competence

    Science.gov (United States)

    Cook, Emily C.; Buehler, Cheryl; Fletcher, Anne C.

    2012-01-01

    This study examined the prospective relationship between negative parenting behaviors and adolescents' friendship competence in a community sample of 416 two-parent families in the Southeastern USA. Adolescents' externalizing problems and their emotional insecurity with parents were examined as mediators. Parents' psychological control was…

  3. Adolescents and Cyber Bullying: The Precaution Adoption Process Model

    Science.gov (United States)

    Chapin, John

    2016-01-01

    A survey of adolescents (N = 1,488) documented Facebook use and experience with cyber bullying. The study found that 84% of adolescents (middle school through college undergraduates) use Facebook, and that most users log on daily. While 30% of the sample reported being cyber bullied, only 12.5% quit using the site, and only 18% told a parent or…

  4. Cyberbullying behavior and adolescents' use of media with antisocial content: a cyclic process model.

    Science.gov (United States)

    den Hamer, Anouk; Konijn, Elly A; Keijer, Micha G

    2014-02-01

    The present study examined the role of media use in adolescents' cyberbullying behavior. Following previous research, we propose a Cyclic Process Model of face-to-face victimization and cyberbullying through two mediating processes of anger/frustration and antisocial media content. This model was tested utilizing a cross-sectional design with adolescent participants (N=892). Exposure to antisocial media content was measured with a newly developed content-based scale (i.e., the C-ME), showing good psychometric qualities. Results of structural equation modeling showed that adolescents' exposure to antisocial media content was significantly associated with cyberbullying behavior, especially in adolescents who experienced anger and frustration due to face-to-face victimization. Goodness of fit indices demonstrated a good fit of the theoretical model to the data and indicated that exposure to antisocial media content acts as an amplifier in a cyclic process of victimization-related anger and cyberbullying behavior.

  5. Performance of Air Pollution Models on Massively Parallel Computers

    DEFF Research Database (Denmark)

    Brown, John; Hansen, Per Christian; Wasniewski, Jerzy

    1996-01-01

    To compare the performance and use of three massively parallel SIMD computers, we implemented a large air pollution model on the computers. Using a realistic large-scale model, we gain detailed insight about the performance of the three computers when used to solve large-scale scientific problems...... that involve several types of numerical computations. The computers considered in our study are the Connection Machines CM-200 and CM-5, and the MasPar MP-2216...

  6. A Community Needs Index for Adolescent Pregnancy Prevention Program Planning: Application of Spatial Generalized Linear Mixed Models.

    Science.gov (United States)

    Johnson, Glen D; Mesler, Kristine; Kacica, Marilyn A

    2017-02-06

    Objective The objective is to estimate community needs with respect to risky adolescent sexual behavior in a way that is risk-adjusted for multiple community factors. Methods Generalized linear mixed modeling was applied for estimating teen pregnancy and sexually transmitted disease (STD) incidence by postal ZIP code in New York State, in a way that adjusts for other community covariables and residual spatial autocorrelation. A community needs index was then obtained by summing the risk-adjusted estimates of pregnancy and STD cases. Results Poisson regression with a spatial random effect was chosen among competing modeling approaches. Both the risk-adjusted caseloads and rates were computed for ZIP codes, which allowed risk-based prioritization to help guide funding decisions for a comprehensive adolescent pregnancy prevention program. Conclusions This approach provides quantitative evidence of community needs with respect to risky adolescent sexual behavior, while adjusting for other community-level variables and stabilizing estimates in areas with small populations. Therefore, it was well accepted by the affected groups and proved valuable for program planning. This methodology may also prove valuable for follow up program evaluation. Current research is directed towards further improving the statistical modeling approach and applying to different health and behavioral outcomes, along with different predictor variables.

  7. Computational Models to Synthesize Human Walking

    Institute of Scientific and Technical Information of China (English)

    Lei Ren; David Howard; Laurence Kenney

    2006-01-01

    The synthesis of human walking is of great interest in biomechanics and biomimetic engineering due to its predictive capabilities and potential applications in clinical biomechanics, rehabilitation engineering and biomimetic robotics. In this paper,the various methods that have been used to synthesize humanwalking are reviewed from an engineering viewpoint. This involves a wide spectrum of approaches, from simple passive walking theories to large-scale computational models integrating the nervous, muscular and skeletal systems. These methods are roughly categorized under four headings: models inspired by the concept of a CPG (Central Pattern Generator), methods based on the principles of control engineering, predictive gait simulation using optimisation, and models inspired by passive walking theory. The shortcomings and advantages of these methods are examined, and future directions are discussed in the context of providing insights into the neural control objectives driving gait and improving the stability of the predicted gaits. Future advancements are likely to be motivated by improved understanding of neural control strategies and the subtle complexities of the musculoskeletal system during human locomotion. It is only a matter of time before predictive gait models become a practical and valuable tool in clinical diagnosis, rehabilitation engineering and robotics.

  8. Methodical Approaches to Teaching of Computer Modeling in Computer Science Course

    Science.gov (United States)

    Rakhimzhanova, B. Lyazzat; Issabayeva, N. Darazha; Khakimova, Tiyshtik; Bolyskhanova, J. Madina

    2015-01-01

    The purpose of this study was to justify of the formation technique of representation of modeling methodology at computer science lessons. The necessity of studying computer modeling is that the current trends of strengthening of general education and worldview functions of computer science define the necessity of additional research of the…

  9. Parenting and Antisocial Behavior: A Model of the Relationship between Adolescent Self-Disclosure, Parental Closeness, Parental Control, and Adolescent Antisocial Behavior

    Science.gov (United States)

    Vieno, Alessio; Nation, Maury; Pastore, Massimiliano; Santinello, Massimo

    2009-01-01

    This study used data collected from a sample of 840 Italian adolescents (418 boys; M age = 12.58) and their parents (657 mothers; M age = 43.78) to explore the relations between parenting, adolescent self-disclosure, and antisocial behavior. In the hypothesized model, parenting practices (e.g., parental monitoring and control) have direct effects…

  10. Preliminary Phase Field Computational Model Development

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yulan [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hu, Shenyang Y. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Xu, Ke [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Suter, Jonathan D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); McCloy, John S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Johnson, Bradley R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Ramuhalli, Pradeep [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-12-15

    This interim report presents progress towards the development of meso-scale models of magnetic behavior that incorporate microstructural information. Modeling magnetic signatures in irradiated materials with complex microstructures (such as structural steels) is a significant challenge. The complexity is addressed incrementally, using the monocrystalline Fe (i.e., ferrite) film as model systems to develop and validate initial models, followed by polycrystalline Fe films, and by more complicated and representative alloys. In addition, the modeling incrementally addresses inclusion of other major phases (e.g., martensite, austenite), minor magnetic phases (e.g., carbides, FeCr precipitates), and minor nonmagnetic phases (e.g., Cu precipitates, voids). The focus of the magnetic modeling is on phase-field models. The models are based on the numerical solution to the Landau-Lifshitz-Gilbert equation. From the computational standpoint, phase-field modeling allows the simulation of large enough systems that relevant defect structures and their effects on functional properties like magnetism can be simulated. To date, two phase-field models have been generated in support of this work. First, a bulk iron model with periodic boundary conditions was generated as a proof-of-concept to investigate major loop effects of single versus polycrystalline bulk iron and effects of single non-magnetic defects. More recently, to support the experimental program herein using iron thin films, a new model was generated that uses finite boundary conditions representing surfaces and edges. This model has provided key insights into the domain structures observed in magnetic force microscopy (MFM) measurements. Simulation results for single crystal thin-film iron indicate the feasibility of the model for determining magnetic domain wall thickness and mobility in an externally applied field. Because the phase-field model dimensions are limited relative to the size of most specimens used in

  11. Final technical report for DOE Computational Nanoscience Project: Integrated Multiscale Modeling of Molecular Computing Devices

    Energy Technology Data Exchange (ETDEWEB)

    Cummings, P. T.

    2010-02-08

    This document reports the outcomes of the Computational Nanoscience Project, "Integrated Multiscale Modeling of Molecular Computing Devices". It includes a list of participants and publications arising from the research supported.

  12. Computational Granular Dynamics Models and Algorithms

    CERN Document Server

    Pöschel, Thorsten

    2005-01-01

    Computer simulations not only belong to the most important methods for the theoretical investigation of granular materials, but also provide the tools that have enabled much of the expanding research by physicists and engineers. The present book is intended to serve as an introduction to the application of numerical methods to systems of granular particles. Accordingly, emphasis is placed on a general understanding of the subject rather than on the presentation of the latest advances in numerical algorithms. Although a basic knowledge of C++ is needed for the understanding of the numerical methods and algorithms in the book, it avoids usage of elegant but complicated algorithms to remain accessible for those who prefer to use a different programming language. While the book focuses more on models than on the physics of granular material, many applications to real systems are presented.

  13. Modeling groundwater flow on massively parallel computers

    Energy Technology Data Exchange (ETDEWEB)

    Ashby, S.F.; Falgout, R.D.; Fogwell, T.W.; Tompson, A.F.B.

    1994-12-31

    The authors will explore the numerical simulation of groundwater flow in three-dimensional heterogeneous porous media. An interdisciplinary team of mathematicians, computer scientists, hydrologists, and environmental engineers is developing a sophisticated simulation code for use on workstation clusters and MPPs. To date, they have concentrated on modeling flow in the saturated zone (single phase), which requires the solution of a large linear system. they will discuss their implementation of preconditioned conjugate gradient solvers. The preconditioners under consideration include simple diagonal scaling, s-step Jacobi, adaptive Chebyshev polynomial preconditioning, and multigrid. They will present some preliminary numerical results, including simulations of groundwater flow at the LLNL site. They also will demonstrate the code`s scalability.

  14. Parenting practices, parental attachment and aggressiveness in adolescence: a predictive model.

    Science.gov (United States)

    Gallarin, Miriam; Alonso-Arbiol, Itziar

    2012-12-01

    The aim of this study was twofold: a) to test the mediation role of attachment between parenting practices and aggressiveness, and b) to clarify the differential role of mothers and fathers with regard to aggressiveness. A total of 554 adolescents (330 girls and 224 boys), ages ranging between 16 and 19, completed measures of mothers' and fathers' parenting practices, attachment to mother and to father, and aggressiveness. Acceptance/involvement of each parent positively predicted an adolescent's attachment to that parent, and coercion/imposition negatively predicted attachment to a lesser extent. Using structural equation modeling, a full mediation model provided the most parsimonious explanation for the data. With attachment in the model, the paths between the two parenting practices and aggressiveness were minor and statistically non-significant. Only attachment to the father, was predictive of adolescents' aggressiveness. Results are discussed in the light of the importance of the father-son/daughter relationship in adolescence.

  15. A theoretical model of health-related outcomes of resilience in middle adolescents.

    Science.gov (United States)

    Scoloveno, Robert

    2015-03-01

    There is a dearth of knowledge about the health outcomes of resilience during adolescence, making the study of health-related outcomes of resilience important. The purpose of this study was to develop a theory-based just-identified model and to test the direct and indirect effects of resilience on hope, well-being, and health-promoting lifestyle in middle adolescents. The study used a correlational design. The final sample consisted of 311 middle adolescents, aged 15 to 17, who were recruited from a public high school. Participants responded to instrument packets in classroom settings. The structural equation model was tested with the LISREL 8.80 software program. All seven hypotheses were supported at a statistically significant level (p resilience. Alternate models of outcomes of resilience need to be tested on adolescents.

  16. Gravothermal Star Clusters - Theory and Computer Modelling

    Science.gov (United States)

    Spurzem, Rainer

    2010-11-01

    In the George Darwin lecture, delivered to the British Royal Astronomical Society in 1960 by Viktor A. Ambartsumian he wrote on the evolution of stellar systems that it can be described by the "dynamic evolution of a gravitating gas" complemented by "a statistical description of the changes in the physical states of stars". This talk will show how this physical concept has inspired theoretical modeling of star clusters in the following decades up to the present day. The application of principles of thermodynamics shows, as Ambartsumian argued in his 1960 lecture, that there is no stable state of equilibrium of a gravitating star cluster. The trend to local thermodynamic equilibrium is always disturbed by escaping stars (Ambartsumian), as well as by gravothermal and gravogyro instabilities, as it was detected later. Here the state-of-the-art of modeling the evolution of dense stellar systems based on principles of thermodynamics and statistical mechanics (Fokker-Planck approximation) will be reviewed. Recent progress including rotation and internal correlations (primordial binaries) is presented. The models have also very successfully been used to study dense star clusters around massive black holes in galactic nuclei and even (in a few cases) relativistic supermassive dense objects in centres of galaxies (here again briefly touching one of the many research fields of V.A. Ambartsumian). For the modern present time of high-speed supercomputing, where we are tackling direct N-body simulations of star clusters, we will show that such direct modeling supports and proves the concept of the statistical models based on the Fokker-Planck theory, and that both theoretical concepts and direct computer simulations are necessary to support each other and make scientific progress in the study of star cluster evolution.

  17. A multidimensional model of mothers' perceptions of parent alcohol socialization and adolescent alcohol misuse.

    Science.gov (United States)

    Ennett, Susan T; Jackson, Christine; Cole, Veronica T; Haws, Susan; Foshee, Vangie A; Reyes, Heathe Luz McNaughton; Burns, Alison Reimuller; Cox, Melissa J; Cai, Li

    2016-02-01

    We assessed a multidimensional model of parent alcohol socialization in which key socialization factors were considered simultaneously to identify combinations of factors that increase or decrease risk for development of adolescent alcohol misuse. Of interest was the interplay between putative risk and protective factors, such as whether the typically detrimental effects on youth drinking of parenting practices tolerant of some adolescent alcohol use are mitigated by an effective overall approach to parenting and parental modeling of modest alcohol use. The sample included 1,530 adolescents and their mothers; adolescents' mean age was 13.0 (SD = .99) at the initial assessment. Latent profile analysis was conducted of mothers' reports of their attitude toward teen drinking, alcohol-specific parenting practices, parental alcohol use and problem use, and overall approach to parenting. The profiles were used to predict trajectories of adolescent alcohol misuse from early to middle adolescence. Four profiles were identified: 2 profiles reflected conservative alcohol-specific parenting practices and 2 reflected alcohol-tolerant practices, all in the context of other attributes. Alcohol misuse accelerated more rapidly from Grade 6 through 10 in the 2 alcohol-tolerant compared with conservative profiles. Results suggest that maternal tolerance of some youth alcohol use, even in the presence of dimensions of an effective parenting style and low parental alcohol use and problem use, is not an effective strategy for reducing risky adolescent alcohol use. (PsycINFO Database Record

  18. The biopsychosocial model of stress in adolescence: self-awareness of performance versus stress reactivity.

    Science.gov (United States)

    Rith-Najarian, Leslie R; McLaughlin, Katie A; Sheridan, Margaret A; Nock, Matthew K

    2014-03-01

    Extensive research among adults supports the biopsychosocial (BPS) model of challenge and threat, which describes relationships among stress appraisals, physiological stress reactivity, and performance; however, no previous studies have examined these relationships in adolescents. Perceptions of stressors as well as physiological reactivity to stress increase during adolescence, highlighting the importance of understanding the relationships among stress appraisals, physiological reactivity, and performance during this developmental period. In this study, 79 adolescent participants reported on stress appraisals before and after a Trier Social Stress Test in which they performed a speech task. Physiological stress reactivity was defined by changes in cardiac output and total peripheral resistance from a baseline rest period to the speech task, and performance on the speech was coded using an objective rating system. We observed in adolescents only two relationships found in past adult research on the BPS model variables: (1) pre-task stress appraisal predicted post-task stress appraisal and (2) performance predicted post-task stress appraisal. Physiological reactivity during the speech was unrelated to pre- and post-task stress appraisals and to performance. We conclude that the lack of association between post-task stress appraisal and physiological stress reactivity suggests that adolescents might have low self-awareness of physiological emotional arousal. Our findings further suggest that adolescent stress appraisals are based largely on their performance during stressful situations. Developmental implications of this potential lack of awareness of one's physiological and emotional state during adolescence are discussed.

  19. Application of computer simulated persons in indoor environmental modeling

    DEFF Research Database (Denmark)

    Topp, C.; Nielsen, P. V.; Sørensen, Dan Nørtoft

    2002-01-01

    Computer simulated persons are often applied when the indoor environment is modeled by computational fluid dynamics. The computer simulated persons differ in size, shape, and level of geometrical complexity, ranging from simple box or cylinder shaped heat sources to more humanlike models. Little...

  20. A Granular Computing Model Based on Tolerance relation

    Institute of Scientific and Technical Information of China (English)

    WANG Guo-yin; HU Feng; HUANG Hai; WU Yu

    2005-01-01

    Granular computing is a new intelligent computing theory based on partition of problem concepts. It is an important problem in Rough Set theory to process incomplete information systems directly. In this paper, a granular computing model based on tolerance relation for processing incomplete information systems is developed. Furthermore, a criteria condition for attribution necessity is proposed in this model.

  1. Computational Modeling of Biological Systems From Molecules to Pathways

    CERN Document Server

    2012-01-01

    Computational modeling is emerging as a powerful new approach for studying and manipulating biological systems. Many diverse methods have been developed to model, visualize, and rationally alter these systems at various length scales, from atomic resolution to the level of cellular pathways. Processes taking place at larger time and length scales, such as molecular evolution, have also greatly benefited from new breeds of computational approaches. Computational Modeling of Biological Systems: From Molecules to Pathways provides an overview of established computational methods for the modeling of biologically and medically relevant systems. It is suitable for researchers and professionals working in the fields of biophysics, computational biology, systems biology, and molecular medicine.

  2. A Survey of Formal Models for Computer Security.

    Science.gov (United States)

    1981-09-30

    presenting the individual models. 6.1 Basic Concepts and Trends The finite state machine model for computation views a computer system as a finite...top-level specification. The simplest description of the top-level model for DSU is given by Walker, et al. [36]. It is a finite state machine model , with

  3. Computational modeling of acute myocardial infarction.

    Science.gov (United States)

    Sáez, P; Kuhl, E

    2016-01-01

    Myocardial infarction, commonly known as heart attack, is caused by reduced blood supply and damages the heart muscle because of a lack of oxygen. Myocardial infarction initiates a cascade of biochemical and mechanical events. In the early stages, cardiomyocytes death, wall thinning, collagen degradation, and ventricular dilation are the immediate consequences of myocardial infarction. In the later stages, collagenous scar formation in the infarcted zone and hypertrophy of the non-infarcted zone are auto-regulatory mechanisms to partly correct for these events. Here we propose a computational model for the short-term adaptation after myocardial infarction using the continuum theory of multiplicative growth. Our model captures the effects of cell death initiating wall thinning, and collagen degradation initiating ventricular dilation. Our simulations agree well with clinical observations in early myocardial infarction. They represent a first step toward simulating the progression of myocardial infarction with the ultimate goal to predict the propensity toward heart failure as a function of infarct intensity, location, and size.

  4. A Packet Routing Model for Computer Networks

    Directory of Open Access Journals (Sweden)

    O. Osunade

    2012-05-01

    Full Text Available The quest for reliable data transmission in today’s computer networks and internetworks forms the basis for which routing schemes need be improved upon. The persistent increase in the size of internetwork leads to a dwindling performance of the present routing algorithms which are meant to provide optimal path for forwarding packets from one network to the other. A mathematical and analytical routing model framework is proposed to address the routing needs to a substantial extent. The model provides schemes typical of packet sources, queuing system within a buffer, links and bandwidth allocation and time-based bandwidth generator in routing chunks of packets to their destinations. Principal to the choice of link are such design considerations as least-congested link in a set of links, normalized throughput, mean delay and mean waiting time and the priority of packets in a set of prioritized packets. These performance metrics were targeted and the resultant outcome is a fair, load-balanced network.

  5. Computer modeling of complete IC fabrication process

    Science.gov (United States)

    Dutton, Robert W.

    1987-05-01

    The development of fundamental algorithms for process and device modeling as well as novel integration of the tools for advanced Integrated Circuit (IC) technology design is discussed. The development of the first complete 2D process simulator, SUPREM 4, is reported. The algorithms are discussed as well as application to local-oxidation and extrinsic diffusion conditions which occur in CMOS AND BiCMOS technologies. The evolution of 1D (SEDAN) and 2D (PISCES) device analysis is discussed. The application of SEDAN to a variety of non-silicon technologies (GaAs and HgCdTe) are considered. A new multi-window analysis capability for PISCES which exploits Monte Carlo analysis of hot carriers has been demonstrated and used to characterize a variety of silicon MOSFET and GaAs MESFET effects. A parallel computer implementation of PISCES has been achieved using a Hypercube architecture. The PISCES program has been used for a range of important device studies including: latchup, analog switch analysis, MOSFET capacitance studies and bipolar transient device for ECL gates. The program is broadly applicable to RAM and BiCMOS technology analysis and design. In the analog switch technology area this research effort has produced a variety of important modeling and advances.

  6. Horticulture for Secondary Level Handicapped Adolescents: The Cherokee County Model.

    Science.gov (United States)

    Frith, Greg H.; And Others

    1981-01-01

    The Cherokee County (Alabama) horticulture training program provides 40 mildly mentally retarded adolescents with vocational training in a marketable skills. The broad spectrum of vocational skills makes horticulture ideal for the handicapped. (DB)

  7. Role-modeling and conversations about giving in the socialization of adolescent charitable giving and volunteering.

    Science.gov (United States)

    Ottoni-Wilhelm, Mark; Estell, David B; Perdue, Neil H

    2014-01-01

    This study investigated the relationship between the monetary giving and volunteering behavior of adolescents and the role-modeling and conversations about giving provided by their parents. The participants are a large nationally-representative sample of 12-18 year-olds from the Panel Study of Income Dynamics' Child Development Supplement (n = 1244). Adolescents reported whether they gave money and whether they volunteered. In a separate interview parents reported whether they talked to their adolescent about giving. In a third interview, parents reported whether they gave money and volunteered. The results show that both role-modeling and conversations about giving are strongly related to adolescents' giving and volunteering. Knowing that both role-modeling and conversation are strongly related to adolescents' giving and volunteering suggests an often over-looked way for practitioners and policy-makers to nurture giving and volunteering among adults: start earlier, during adolescence, by guiding parents in their role-modeling of, and conversations about, charitable giving and volunteering.

  8. Enhancing conflict negotiation strategies of adolescents with autism spectrum disorder using video modeling.

    Science.gov (United States)

    Hochhauser, M; Weiss, P L; Gal, E

    2016-12-21

    Adolescents with autism spectrum disorder (ASD) have particular difficulty in negotiating conflict. A randomized control trial (RCT) was carried out to determine whether the negotiation strategies of adolescents with ASD would be enhanced via a 6-week intervention based on a video modeling application. Adolescents with ASD, aged 12-18 years, were randomly divided into an intervention group (n = 36) and a non-treatment control group (n = 25). Participants' negotiating strategies prior to and following the intervention were measured using the Five Factor Negotiation Scale (FFNS; Nakkula & Nikitopoulos, 1999) and the ConflicTalk questionnaire (Kimsey & Fuller, 2003). The results suggest that video modeling is an effective intervention for improving and maintaining conflict negotiation strategies of adolescents with ASD.

  9. 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

  10. Computational and Modeling Strategies for Cell Motility

    Science.gov (United States)

    Wang, Qi; Yang, Xiaofeng; Adalsteinsson, David; Elston, Timothy C.; Jacobson, Ken; Kapustina, Maryna; Forest, M. Gregory

    A predictive simulation of the dynamics of a living cell remains a fundamental modeling and computational challenge. The challenge does not even make sense unless one specifies the level of detail and the phenomena of interest, whether the focus is on near-equilibrium or strongly nonequilibrium behavior, and on localized, subcellular, or global cell behavior. Therefore, choices have to be made clear at the outset, ranging from distinguishing between prokaryotic and eukaryotic cells, specificity within each of these types, whether the cell is "normal," whether one wants to model mitosis, blebs, migration, division, deformation due to confined flow as with red blood cells, and the level of microscopic detail for any of these processes. The review article by Hoffman and Crocker [48] is both an excellent overview of cell mechanics and an inspiration for our approach. One might be interested, for example, in duplicating the intricate experimental details reported in [43]: "actin polymerization periodically builds a mechanical link, the lamellipodium, connecting myosin motors with the initiation of adhesion sites, suggesting that the major functions driving motility are coordinated by a biomechanical process," or to duplicate experimental evidence of traveling waves in cells recovering from actin depolymerization [42, 35]. Modeling studies of lamellipodial structure, protrusion, and retraction behavior range from early mechanistic models [84] to more recent deterministic [112, 97] and stochastic [51] approaches with significant biochemical and structural detail. Recent microscopic-macroscopic models and algorithms for cell blebbing have been developed by Young and Mitran [116], which update cytoskeletal microstructure via statistical sampling techniques together with fluid variables. Alternatively, whole cell compartment models (without spatial details) of oscillations in spreading cells have been proposed [35, 92, 109] which show positive and negative feedback

  11. Modeling the growth of fingerprints improves matching for adolescents

    CERN Document Server

    Gottschlich, Carsten; Lorenz, Robert; Bernhardt, Stefanie; Hantschel, Michael; Munk, Axel

    2010-01-01

    We study the effect of growth on the fingerprints of adolescents, based on which we suggest a simple method to adjust for growth when trying to recover a juvenile's fingerprint in a database years later. Based on longitudinal data sets in juveniles' criminal records, we show that growth essentially leads to an isotropic rescaling, so that we can use the strong correlation between growth in stature and limbs to model the growth of fingerprints proportional to stature growth as documented in growth charts. The proposed rescaling leads to a 72% reduction of the distances between corresponding minutiae for the data set analyzed. These findings were corroborated by several verification tests. In an identification test on a database containing 3.25 million right index fingers at the Federal Criminal Police Office of Germany, the identification error rate of 20.8% was reduced to 2.1% by rescaling. The presented method is of striking simplicity and can easily be integrated into existing automated fingerprint identifi...

  12. 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.

  13. A qualitative study of parental modeling and social support for physical activity in underserved adolescents

    OpenAIRE

    Wright, Marcie S.; Wilson, Dawn K.; Griffin, Sarah; Evans, Alexandra

    2008-01-01

    This study obtained qualitative data to assess how parental role modeling and parental social support influence physical activity in underserved (minority, low-income) adolescents. Fifty-two adolescents (22 males, 30 females; ages 10–14 years, 85% African-American) participated in a focus group (6–10 per group, same gender). Focus groups were audiotaped, transcribed and coded by independent raters. Inter-rater reliabilities indicated adequate agreement [inter-rater reliability (r) = 0.84]. Th...

  14. Elements of matrix modeling and computing with Matlab

    CERN Document Server

    White, Robert E

    2006-01-01

    As discrete models and computing have become more common, there is a need to study matrix computation and numerical linear algebra. Encompassing a diverse mathematical core, Elements of Matrix Modeling and Computing with MATLAB examines a variety of applications and their modeling processes, showing you how to develop matrix models and solve algebraic systems. Emphasizing practical skills, it creates a bridge from problems with two and three variables to more realistic problems that have additional variables. Elements of Matrix Modeling and Computing with MATLAB focuses on seven basic applicat

  15. Modelling, abstraction, and computation in systems biology: A view from computer science.

    Science.gov (United States)

    Melham, Tom

    2013-04-01

    Systems biology is centrally engaged with computational modelling across multiple scales and at many levels of abstraction. Formal modelling, precise and formalised abstraction relationships, and computation also lie at the heart of computer science--and over the past decade a growing number of computer scientists have been bringing their discipline's core intellectual and computational tools to bear on biology in fascinating new ways. This paper explores some of the apparent points of contact between the two fields, in the context of a multi-disciplinary discussion on conceptual foundations of systems biology.

  16. Model Minority Stereotyping, Perceived Discrimination, and Adjustment Among Adolescents from Asian American Backgrounds.

    Science.gov (United States)

    Kiang, Lisa; Witkow, Melissa R; Thompson, Taylor L

    2016-07-01

    The model minority image is a common and pervasive stereotype that Asian American adolescents must navigate. Using multiwave data from 159 adolescents from Asian American backgrounds (mean age at initial recruitment = 15.03, SD = .92; 60 % female; 74 % US-born), the current study targeted unexplored aspects of the model minority experience in conjunction with more traditionally measured experiences of negative discrimination. When examining normative changes, perceptions of model minority stereotyping increased over the high school years while perceptions of discrimination decreased. Both experiences were not associated with each other, suggesting independent forms of social interactions. Model minority stereotyping generally promoted academic and socioemotional adjustment, whereas discrimination hindered outcomes. Moreover, in terms of academic adjustment, the model minority stereotype appears to protect against the detrimental effect of discrimination. Implications of the complex duality of adolescents' social interactions are discussed.

  17. An examination of the tripartite model of anxiety and depression in an outpatient sample of adolescents.

    Science.gov (United States)

    Dia, David A; Harrington, Donna; Silverman, Wendy K

    2010-07-01

    Anxiety and depressive disorders are the most common mental health problems for adolescents; understanding their etiology and course is necessary for developing effective prevention and treatment programs. The tripartite model of anxiety and depression was evaluated in a random, clinical sample of 185 adolescents, with an average age of 15.09 years (SD = 1.9), with 58.4% males (n = 108). Survey packets were mailed to participants (61% response rate). Two models were evaluated: (a) Model one fit adequately, however, modification indices and prior research and theory suggested adding paths between anxiety and depression. (b) Model two tested paths between anxiety and depression; this revised model fit the data well, suggesting a relationship from anxiety to depression. Further, physiological hyperarousal may be a distinct component for anxiety and negative affectivity may be a general risk factor for anxiety and depression in adolescents. The findings that different factors contribute to the cause of anxiety and depression have implications for practice.

  18. Predictive Capability Maturity Model for computational modeling and simulation.

    Energy Technology Data Exchange (ETDEWEB)

    Oberkampf, William Louis; Trucano, Timothy Guy; Pilch, Martin M.

    2007-10-01

    The Predictive Capability Maturity Model (PCMM) is a new model that can be used to assess the level of maturity of computational modeling and simulation (M&S) efforts. The development of the model is based on both the authors experience and their analysis of similar investigations in the past. The perspective taken in this report is one of judging the usefulness of a predictive capability that relies on the numerical solution to partial differential equations to better inform and improve decision making. The review of past investigations, such as the Software Engineering Institute's Capability Maturity Model Integration and the National Aeronautics and Space Administration and Department of Defense Technology Readiness Levels, indicates that a more restricted, more interpretable method is needed to assess the maturity of an M&S effort. The PCMM addresses six contributing elements to M&S: (1) representation and geometric fidelity, (2) physics and material model fidelity, (3) code verification, (4) solution verification, (5) model validation, and (6) uncertainty quantification and sensitivity analysis. For each of these elements, attributes are identified that characterize four increasing levels of maturity. Importantly, the PCMM is a structured method for assessing the maturity of an M&S effort that is directed toward an engineering application of interest. The PCMM does not assess whether the M&S effort, the accuracy of the predictions, or the performance of the engineering system satisfies or does not satisfy specified application requirements.

  19. Direct and Indirect Effects of Parental Influence upon Adolescent Alcohol Use: A Structural Equation Modeling Analysis

    Science.gov (United States)

    Kim, Young-Mi; Neff, James Alan

    2010-01-01

    A model incorporating the direct and indirect effects of parental monitoring on adolescent alcohol use was evaluated by applying structural equation modeling (SEM) techniques to data on 4,765 tenth-graders in the 2001 Monitoring the Future Study. Analyses indicated good fit of hypothesized measurement and structural models. Analyses supported both…

  20. A Web-Based Computer-Tailored Alcohol Prevention Program for Adolescents: Cost-Effectiveness and Intersectoral Costs and Benefits

    Science.gov (United States)

    2016-01-01

    Background Preventing excessive alcohol use among adolescents is important not only to foster individual and public health, but also to reduce alcohol-related costs inside and outside the health care sector. Computer tailoring can be both effective and cost-effective for working with many lifestyle behaviors, yet the available information on the cost-effectiveness of computer tailoring for reducing alcohol use by adolescents is limited as is information on the costs and benefits pertaining to sectors outside the health care sector, also known as intersectoral costs and benefits (ICBs). Objective The aim was to assess the cost-effectiveness of a Web-based computer-tailored intervention for reducing alcohol use and binge drinking by adolescents from a health care perspective (excluding ICBs) and from a societal perspective (including ICBs). Methods Data used were from the Alcoholic Alert study, a cluster randomized controlled trial with randomization at the level of schools into two conditions. Participants either played a game with tailored feedback on alcohol awareness after the baseline assessment (intervention condition) or received care as usual (CAU), meaning that they had the opportunity to play the game subsequent to the final measurement (waiting list control condition). Data were recorded at baseline (T0=January/February 2014) and after 4 months (T1=May/June 2014) and were used to calculate incremental cost-effectiveness ratios (ICERs), both from a health care perspective and a societal perspective. Stochastic uncertainty in the data was dealt with by using nonparametric bootstraps (5000 simulated replications). Additional sensitivity analyses were conducted based on excluding cost outliers. Subgroup cost-effectiveness analyses were conducted based on several background variables, including gender, age, educational level, religion, and ethnicity. Results From both the health care perspective and the societal perspective for both outcome measures, the

  1. Experiments and simulation models of a basic computation element of an autonomous molecular computing system.

    Science.gov (United States)

    Takinoue, Masahiro; Kiga, Daisuke; Shohda, Koh-Ichiroh; Suyama, Akira

    2008-10-01

    Autonomous DNA computers have been attracting much attention because of their ability to integrate into living cells. Autonomous DNA computers can process information through DNA molecules and their molecular reactions. We have already proposed an idea of an autonomous molecular computer with high computational ability, which is now named Reverse-transcription-and-TRanscription-based Autonomous Computing System (RTRACS). In this study, we first report an experimental demonstration of a basic computation element of RTRACS and a mathematical modeling method for RTRACS. We focus on an AND gate, which produces an output RNA molecule only when two input RNA molecules exist, because it is one of the most basic computation elements in RTRACS. Experimental results demonstrated that the basic computation element worked as designed. In addition, its behaviors were analyzed using a mathematical model describing the molecular reactions of the RTRACS computation elements. A comparison between experiments and simulations confirmed the validity of the mathematical modeling method. This study will accelerate construction of various kinds of computation elements and computational circuits of RTRACS, and thus advance the research on autonomous DNA computers.

  2. Learning Anatomy: Do New Computer Models Improve Spatial Understanding?

    Science.gov (United States)

    Garg, Amit; Norman, Geoff; Spero, Lawrence; Taylor, Ian

    1999-01-01

    Assesses desktop-computer models that rotate in virtual three-dimensional space. Compares spatial learning with a computer carpal-bone model horizontally rotating at 10-degree views with the same model rotating at 90-degree views. (Author/CCM)

  3. Infinite Time Cellular Automata: A Real Computation Model

    CERN Document Server

    Givors, Fabien; Ollinger, Nicolas

    2010-01-01

    We define a new transfinite time model of computation, infinite time cellular automata. The model is shown to be as powerful than infinite time Turing machines, both on finite and infinite inputs; thus inheriting many of its properties. We then show how to simulate the canonical real computation model, BSS machines, with infinite time cellular automata in exactly \\omega steps.

  4. Graph Partitioning Models for Parallel Computing

    Energy Technology Data Exchange (ETDEWEB)

    Hendrickson, B.; Kolda, T.G.

    1999-03-02

    Calculations can naturally be described as graphs in which vertices represent computation and edges reflect data dependencies. By partitioning the vertices of a graph, the calculation can be divided among processors of a parallel computer. However, the standard methodology for graph partitioning minimizes the wrong metric and lacks expressibility. We survey several recently proposed alternatives and discuss their relative merits.

  5. Emotional closeness to parents and grandparents: A moderated mediation model predicting adolescent adjustment.

    Science.gov (United States)

    Attar-Schwartz, Shalhevet

    2015-09-01

    Warm and emotionally close relationships with parents and grandparents have been found in previous studies to be linked with better adolescent adjustment. The present study, informed by Family Systems Theory and Intergenerational Solidarity Theory, uses a moderated mediation model analyzing the contribution of the dynamics of these intergenerational relationships to adolescent adjustment. Specifically, it examines the mediating role of emotional closeness to the closest grandparent in the relationship between emotional closeness to a parent (the offspring of the closest grandparent) and adolescent adjustment difficulties. The model also examines the moderating role of emotional closeness to parents in the relationship between emotional closeness to grandparents and adjustment difficulties. The study was based on a sample of 1,405 Jewish Israeli secondary school students (ages 12-18) who completed a structured questionnaire. It was found that emotional closeness to the closest grandparent was more strongly associated with reduced adjustment difficulties among adolescents with higher levels of emotional closeness to their parents. In addition, adolescent adjustment and emotional closeness to parents was partially mediated by emotional closeness to grandparents. Examining the family conditions under which adolescents' relationships with grandparents is stronger and more beneficial for them can help elucidate variations in grandparent-grandchild ties and expand our understanding of the mechanisms that shape child outcomes.

  6. Translational relevance of rodent models of hypothalamic-pituitary-adrenal function and stressors in adolescence

    Directory of Open Access Journals (Sweden)

    Cheryl M. McCormick

    2017-02-01

    Full Text Available Elevations in glucocorticoids that result from environmental stressors can have programming effects on brain structure and function when the exposure occurs during sensitive periods that involve heightened neural development. In recent years, adolescence has gained increasing attention as another sensitive period of development, a period in which pubertal transitions may increase the vulnerability to stressors. There are similarities in physical and behavioural development between humans and rats, and rats have been used effectively as an animal model of adolescence and the unique plasticity of this period of ontogeny. This review focuses on benefits and challenges of rats as a model for translational research on hypothalamic-pituitary-adrenal (HPA function and stressors in adolescence, highlighting important parallels and contrasts between adolescent rats and humans, and we review the main stress procedures that are used in investigating HPA stress responses and their consequences in adolescence in rats. We conclude that a greater focus on timing of puberty as a factor in research in adolescent rats may increase the translational relevance of the findings.

  7. COMPUTER MODEL FOR ORGANIC FERTILIZER EVALUATION

    Directory of Open Access Journals (Sweden)

    Zdenko Lončarić

    2009-12-01

    seedlings with highest mass and leaf area are produced using growing media with pH close to 6 and with EC lower than 2 dSm-1. It could be concluded that conductivity approx. 3 dSm-1 has inhibitory effect on lettuce if pH is about 7 or higher. The computer model shows that raising pH and EC resulted in decreasing growth which could be expressed as increasing stress index. The lettuce height as a function of pH and EC is incorporated into the model as stress function showing increase of lettuce height by lowering EC from 4 to 1 dSm-1or pH from 7.4 to 6. The highest growing media index (8.1 was determined for mixture of composted pig manure and peat (1:1, and lowest (2.3 for composted horse manure and peat (1:2.

  8. The complete guide to blender graphics computer modeling and animation

    CERN Document Server

    Blain, John M

    2014-01-01

    Smoothly Leads Users into the Subject of Computer Graphics through the Blender GUIBlender, the free and open source 3D computer modeling and animation program, allows users to create and animate models and figures in scenes, compile feature movies, and interact with the models and create video games. Reflecting the latest version of Blender, The Complete Guide to Blender Graphics: Computer Modeling & Animation, 2nd Edition helps beginners learn the basics of computer animation using this versatile graphics program. This edition incorporates many new features of Blender, including developments

  9. Reduced computational models of serotonin synthesis, release, and reuptake.

    Science.gov (United States)

    Flower, Gordon; Wong-Lin, KongFatt

    2014-04-01

    Multiscale computational models can provide systemic evaluation and prediction of neuropharmacological drug effects. To date, little computational modeling work has been done to bridge from intracellular to neuronal circuit level. A complex model that describes the intracellular dynamics of the presynaptic terminal of a serotonergic neuron has been previously proposed. By systematically perturbing the model's components, we identify the slow and fast dynamical components of the model, and the reduced slow or fast mode of the model is computationally significantly more efficient with accuracy not deviating much from the original model. The reduced fast-mode model is particularly suitable for incorporating into neurobiologically realistic spiking neuronal models, and hence for large-scale realistic computational simulations. We also develop user-friendly software based on the reduced models to allow scientists to rapidly test and predict neuropharmacological drug effects at a systems level.

  10. An Emotional Agent Model Based on Granular Computing

    Directory of Open Access Journals (Sweden)

    Jun Hu

    2012-01-01

    Full Text Available Affective computing has a very important significance for fulfilling intelligent information processing and harmonious communication between human being and computers. A new model for emotional agent is proposed in this paper to make agent have the ability of handling emotions, based on the granular computing theory and the traditional BDI agent model. Firstly, a new emotion knowledge base based on granular computing for emotion expression is presented in the model. Secondly, a new emotional reasoning algorithm based on granular computing is proposed. Thirdly, a new emotional agent model based on granular computing is presented. Finally, based on the model, an emotional agent for patient assistant in hospital is realized, experiment results show that it is efficient to handle simple emotions.

  11. Performance Models for Split-execution Computing Systems

    Energy Technology Data Exchange (ETDEWEB)

    Humble, Travis S [ORNL; McCaskey, Alex [ORNL; Schrock, Jonathan [ORNL; Seddiqi, Hadayat [ORNL; Britt, Keith A [ORNL; Imam, Neena [ORNL

    2016-01-01

    Split-execution computing leverages the capabilities of multiple computational models to solve problems, but splitting program execution across different computational models incurs costs associated with the translation between domains. We analyze the performance of a split-execution computing system developed from conventional and quantum processing units (QPUs) by using behavioral models that track resource usage. We focus on asymmetric processing models built using conventional CPUs and a family of special-purpose QPUs that employ quantum computing principles. Our performance models account for the translation of a classical optimization problem into the physical representation required by the quantum processor while also accounting for hardware limitations and conventional processor speed and memory. We conclude that the bottleneck in this split-execution computing system lies at the quantum-classical interface and that the primary time cost is independent of quantum processor behavior.

  12. Model for personal computer system selection.

    Science.gov (United States)

    Blide, L

    1987-12-01

    Successful computer software and hardware selection is best accomplished by following an organized approach such as the one described in this article. The first step is to decide what you want to be able to do with the computer. Secondly, select software that is user friendly, well documented, bug free, and that does what you want done. Next, you select the computer, printer and other needed equipment from the group of machines on which the software will run. Key factors here are reliability and compatibility with other microcomputers in your facility. Lastly, you select a reliable vendor who will provide good, dependable service in a reasonable time. The ability to correctly select computer software and hardware is a key skill needed by medical record professionals today and in the future. Professionals can make quality computer decisions by selecting software and systems that are compatible with other computers in their facility, allow for future net-working, ease of use, and adaptability for expansion as new applications are identified. The key to success is to not only provide for your present needs, but to be prepared for future rapid expansion and change in your computer usage as technology and your skills grow.

  13. Multicentre chest computed tomography standardisation in children and adolescents with cystic fibrosis

    DEFF Research Database (Denmark)

    Kuo, Wieying; Kemner-van de Corput, Mariette P. C.; Perez-Rovira, Adria

    2016-01-01

    was found in CT protocols, image quality and radiation dose usage among the centres. However, the performance of all CT scanners was found to be very similar, when taking spatial resolution and radiation dose into account. We conclude that multicentre standardisation of chest CT in children and adolescents...

  14. Improving the Dietary Patterns of Adolescents Using a Computer-Based Approach

    Science.gov (United States)

    Casazza, Krista; Ciccazzo, Michele

    2006-01-01

    The Centers for Disease Control and Prevention (CDC) recently reported that 16-33% of children and adolescents in the United States are overweight or obese, making this the number one nutritional disease of this group. The prevalence appears to be increasing annually, as are the associated consequences. Moreover, the CDC estimates that less than…

  15. Ablative Rocket Deflector Testing and Computational Modeling

    Science.gov (United States)

    Allgood, Daniel C.; Lott, Jeffrey W.; Raines, Nickey

    2010-01-01

    A deflector risk mitigation program was recently conducted at the NASA Stennis Space Center. The primary objective was to develop a database that characterizes the behavior of industry-grade refractory materials subjected to rocket plume impingement conditions commonly experienced on static test stands. The program consisted of short and long duration engine tests where the supersonic exhaust flow from the engine impinged on an ablative panel. Quasi time-dependent erosion depths and patterns generated by the plume impingement were recorded for a variety of different ablative materials. The erosion behavior was found to be highly dependent on the material s composition and corresponding thermal properties. For example, in the case of the HP CAST 93Z ablative material, the erosion rate actually decreased under continued thermal heating conditions due to the formation of a low thermal conductivity "crystallization" layer. The "crystallization" layer produced near the surface of the material provided an effective insulation from the hot rocket exhaust plume. To gain further insight into the complex interaction of the plume with the ablative deflector, computational fluid dynamic modeling was performed in parallel to the ablative panel testing. The results from the current study demonstrated that locally high heating occurred due to shock reflections. These localized regions of shock-induced heat flux resulted in non-uniform erosion of the ablative panels. In turn, it was observed that the non-uniform erosion exacerbated the localized shock heating causing eventual plume separation and reversed flow for long duration tests under certain conditions. Overall, the flow simulations compared very well with the available experimental data obtained during this project.

  16. Computer modeling of a convective steam superheater

    Directory of Open Access Journals (Sweden)

    Trojan Marcin

    2015-03-01

    Full Text Available Superheater is for generating superheated steam from the saturated steam from the evaporator outlet. In the case of pulverized coal fired boiler, a relatively small amount of ash causes problems with ash fouling on the heating surfaces, including the superheaters. In the convection pass of the boiler, the flue gas temperature is lower and ash deposits can be loose or sintered. Ash fouling not only reduces heat transfer from the flue gas to the steam, but also is the cause of a higher pressure drop on the flue gas flow path. In the case the pressure drop is greater than the power consumed by the fan increases. If the superheater surfaces are covered with ash than the steam temperature at the outlet of the superheater stages falls, and the flow rates of the water injected into attemperator should be reduced. There is also an increase in flue gas temperature after the different stages of the superheater. Consequently, this leads to a reduction in boiler efficiency. The paper presents the results of computational fluid dynamics simulations of the first stage superheater of both the boiler OP-210M using the commercial software. The temperature distributions of the steam and flue gas along the way they flow together with temperature of the tube walls and temperature of the ash deposits will be determined. The calculated steam temperature is compared with measurement results. Knowledge of these temperatures is of great practical importance because it allows to choose the grade of steel for a given superheater stage. Using the developed model of the superheater to determine its degree of ash fouling in the on-line mode one can control the activation frequency of steam sootblowers.

  17. Computer modeling of a convective steam superheater

    Science.gov (United States)

    Trojan, Marcin

    2015-03-01

    Superheater is for generating superheated steam from the saturated steam from the evaporator outlet. In the case of pulverized coal fired boiler, a relatively small amount of ash causes problems with ash fouling on the heating surfaces, including the superheaters. In the convection pass of the boiler, the flue gas temperature is lower and ash deposits can be loose or sintered. Ash fouling not only reduces heat transfer from the flue gas to the steam, but also is the cause of a higher pressure drop on the flue gas flow path. In the case the pressure drop is greater than the power consumed by the fan increases. If the superheater surfaces are covered with ash than the steam temperature at the outlet of the superheater stages falls, and the flow rates of the water injected into attemperator should be reduced. There is also an increase in flue gas temperature after the different stages of the superheater. Consequently, this leads to a reduction in boiler efficiency. The paper presents the results of computational fluid dynamics simulations of the first stage superheater of both the boiler OP-210M using the commercial software. The temperature distributions of the steam and flue gas along the way they flow together with temperature of the tube walls and temperature of the ash deposits will be determined. The calculated steam temperature is compared with measurement results. Knowledge of these temperatures is of great practical importance because it allows to choose the grade of steel for a given superheater stage. Using the developed model of the superheater to determine its degree of ash fouling in the on-line mode one can control the activation frequency of steam sootblowers.

  18. Soft Computing Models in Industrial and Environmental Applications

    CERN Document Server

    Abraham, Ajith; Corchado, Emilio; 7th International Conference, SOCO’12

    2013-01-01

    This volume of Advances in Intelligent and Soft Computing contains accepted papers presented at SOCO 2012, held in the beautiful and historic city of Ostrava (Czech Republic), in September 2012.   Soft computing represents a collection or set of computational techniques in machine learning, computer science and some engineering disciplines, which investigate, simulate, and analyze very complex issues and phenomena.   After a through peer-review process, the SOCO 2012 International Program Committee selected 75 papers which are published in these conference proceedings, and represents an acceptance rate of 38%. In this relevant edition a special emphasis was put on the organization of special sessions. Three special sessions were organized related to relevant topics as: Soft computing models for Control Theory & Applications in Electrical Engineering, Soft computing models for biomedical signals and data processing and Advanced Soft Computing Methods in Computer Vision and Data Processing.   The selecti...

  19. Scaling predictive modeling in drug development with cloud computing.

    Science.gov (United States)

    Moghadam, Behrooz Torabi; Alvarsson, Jonathan; Holm, Marcus; Eklund, Martin; Carlsson, Lars; Spjuth, Ola

    2015-01-26

    Growing data sets with increased time for analysis is hampering predictive modeling in drug discovery. Model building can be carried out on high-performance computer clusters, but these can be expensive to purchase and maintain. We have evaluated ligand-based modeling on cloud computing resources where computations are parallelized and run on the Amazon Elastic Cloud. We trained models on open data sets of varying sizes for the end points logP and Ames mutagenicity and compare with model building parallelized on a traditional high-performance computing cluster. We show that while high-performance computing results in faster model building, the use of cloud computing resources is feasible for large data sets and scales well within cloud instances. An additional advantage of cloud computing is that the costs of predictive models can be easily quantified, and a choice can be made between speed and economy. The easy access to computational resources with no up-front investments makes cloud computing an attractive alternative for scientists, especially for those without access to a supercomputer, and our study shows that it enables cost-efficient modeling of large data sets on demand within reasonable time.

  20. Differential behavioural and neurochemical outcomes from chronic paroxetine treatment in adolescent and adult rats: a model of adverse antidepressant effects in human adolescents?

    Science.gov (United States)

    Karanges, Emily; Li, Kong M; Motbey, Craig; Callaghan, Paul D; Katsifis, Andrew; McGregor, Iain S

    2011-05-01

    Selective serotonin reuptake inhibitor use is associated with increased risk of suicidal ideation in adolescent humans, yet the neuropharmacological basis of this phenomenon is unknown. Consequently, we examined the behavioural and neurochemical effects of chronic paroxetine (PRX) treatment in adult and adolescent rats. Rats received PRX in their drinking water (target dose 10 mg/kg) for 22 d, during which time they were assessed for depression- and anxiety-like behaviours. Subsequent ex-vivo analyses examined serum PRX concentrations, striatal neurotransmitter content, and regional serotonin and dopamine transporter (SERT, DAT) binding density. After 11-12 d treatment, PRX-treated adolescent rats showed a significant inhibition of social interaction while adults were unaffected. After 19-20 d treatment, adolescents failed to show an antidepressant-like effect of PRX treatment on the forced swim test (FST), while PRX-treated adults showed a typical decrease in immobility and increase in swimming. Two PRX-treated adolescents died unexpectedly after the FST suggesting a compromised response to physical stress. Despite their greater apparent adverse reaction to the drug, adolescents had significantly lower plasma PRX than adults at day 22 of treatment. Chronic PRX treatment had similar effects in adults and adolescents on striatal 5-HT (unchanged relative to controls) and 5-HIAA levels (decreased), while markers of dopaminergic function (DOPAC, HVA, DA turnover) were increased in adults only. SERT density was up-regulated in the amygdala in PRX-treated adolescents only while DAT density in the nucleus accumbens was down-regulated only in PRX-treated adults. These data suggest that the immature rat brain responds differently to PRX and that this might be of use in modelling the atypical response of human adolescents to antidepressants. The age-specific PRX-induced changes in dopaminergic markers and SERT and DAT binding provide clues as to the neural mechanisms

  1. The emerging role of cloud computing in molecular modelling.

    Science.gov (United States)

    Ebejer, Jean-Paul; Fulle, Simone; Morris, Garrett M; Finn, Paul W

    2013-07-01

    There is a growing recognition of the importance of cloud computing for large-scale and data-intensive applications. The distinguishing features of cloud computing and their relationship to other distributed computing paradigms are described, as are the strengths and weaknesses of the approach. We review the use made to date of cloud computing for molecular modelling projects and the availability of front ends for molecular modelling applications. Although the use of cloud computing technologies for molecular modelling is still in its infancy, we demonstrate its potential by presenting several case studies. Rapid growth can be expected as more applications become available and costs continue to fall; cloud computing can make a major contribution not just in terms of the availability of on-demand computing power, but could also spur innovation in the development of novel approaches that utilize that capacity in more effective ways.

  2. Reduced order methods for modeling and computational reduction

    CERN Document Server

    Rozza, Gianluigi

    2014-01-01

    This monograph addresses the state of the art of reduced order methods for modeling and computational reduction of complex parametrized systems, governed by ordinary and/or partial differential equations, with a special emphasis on real time computing techniques and applications in computational mechanics, bioengineering and computer graphics.  Several topics are covered, including: design, optimization, and control theory in real-time with applications in engineering; data assimilation, geometry registration, and parameter estimation with special attention to real-time computing in biomedical engineering and computational physics; real-time visualization of physics-based simulations in computer science; the treatment of high-dimensional problems in state space, physical space, or parameter space; the interactions between different model reduction and dimensionality reduction approaches; the development of general error estimation frameworks which take into account both model and discretization effects. This...

  3. Sticker DNA computer model--Part Ⅰ:Theory

    Institute of Scientific and Technical Information of China (English)

    XU Jin; DONG Yafei; WEI Xiaopeng

    2004-01-01

    Sticker model is one of the basic models in the DNA computer models. This model is coded with single-double stranded DNA molecules. It has the following advantages that the operations require no strands extension and use no enzymes; What's more, the materials are reusable. Therefore it arouses attention and interest of scientists in many fields. In this paper, we will systematically analyze the theories and applications of the model, summarize other scientists' contributions in this field, and propose our research results. This paper is the theoretical portion of the sticker model on DNA computer, which includes the introduction of the basic model of sticker computing. Firstly, we systematically introduce the basic theories of classic models about sticker computing; Secondly, we discuss the sticker system which is an abstract computing model based on the sticker model and formal languages; Finally, extend and perfect the model, and present two types of models that are more extensive in the applications and more perfect in the theory than the past models: one is the so-called k-bit sticker model, the other is full-message sticker DNA computing model.

  4. Los Alamos CCS (Center for Computer Security) formal computer security model

    Energy Technology Data Exchange (ETDEWEB)

    Dreicer, J.S.; Hunteman, W.J. (Los Alamos National Lab., NM (USA))

    1989-01-01

    This paper provides a brief presentation of the formal computer security model currently being developed at the Los Alamos Department of Energy (DOE) Center for Computer Security (CCS). The initial motivation for this effort was the need to provide a method by which DOE computer security policy implementation could be tested and verified. The actual analytical model was a result of the integration of current research in computer security and previous modeling and research experiences. The model is being developed to define a generic view of the computer and network security domains, to provide a theoretical basis for the design of a security model, and to address the limitations of present models. Formal mathematical models for computer security have been designed and developed in conjunction with attempts to build secure computer systems since the early 70's. The foundation of the Los Alamos DOE CCS model is a series of functionally dependent probability equations, relations, and expressions. The mathematical basis appears to be justified and is undergoing continued discrimination and evolution. We expect to apply the model to the discipline of the Bell-Lapadula abstract sets of objects and subjects. 5 refs.

  5. Behavior computing modeling, analysis, mining and decision

    CERN Document Server

    2012-01-01

    Includes six case studies on behavior applications Presents new techniques for capturing behavior characteristics in social media First dedicated source of references for the theory and applications of behavior informatics and behavior computing

  6. Analog models of computations \\& Effective Church Turing Thesis: Efficient simulation of Turing machines by the General Purpose Analog Computer

    CERN Document Server

    Pouly, Amaury; Graça, Daniel S

    2012-01-01

    \\emph{Are analog models of computations more powerful than classical models of computations?} From a series of recent papers, it is now clear that many realistic analog models of computations are provably equivalent to classical digital models of computations from a \\emph{computability} point of view. Take, for example, the probably most realistic model of analog computation, the General Purpose Analog Computer (GPAC) model from Claude Shannon, a model for Differential Analyzers, which are analog machines used from 1930s to early 1960s to solve various problems. It is now known that functions computable by Turing machines are provably exactly those that are computable by GPAC. This paper is about next step: understanding if this equivalence also holds at the \\emph{complexity} level. In this paper we show that the realistic models of analog computation -- namely the General Purpose Analog Computer (GPAC) -- can simulate Turing machines in a computationally efficient manner. More concretely we show that, modulo...

  7. Dissemination of computer skills among physicians: the infectious process model.

    Science.gov (United States)

    Quinn, F B; Hokanson, J A; McCracken, M M; Stiernberg, C M

    1984-08-01

    While the potential utility of computer technology to medicine is often acknowledged, little is known as to the best methods to actually teach physicians about computers. The current variability in physician computer fluency implies there is no accepted minimum required level of computer skills for physicians. Special techniques are needed to instill these skills in the physician and measure their effects within the medical profession. This hypothesis is suggested following the development of a specialized course for the new physician. In a population of physicians where medical computing usage was considered nonexistent, intense interest developed the following exposure to a role model having strong credentials in both medicine and computer science. This produced an atmosphere where there was a perceived benefit in being knowledgeable about the medical computer usage. The subsequent increase in computer systems use was the result of the availability of resources and development of computer skills that could be exchanged among the students and faculty. This growth in computer use is described using the parameters of an infectious process model. While other approaches may also be useful, the infectious process model permits the growth of medical computer usage to be quantitatively described, evaluates specific determinants of use patterns, and allows the future growth of computer utilization in medicine to be predicted.

  8. Studying an Eulerian Computer Model on Different High-performance Computer Platforms and Some Applications

    Science.gov (United States)

    Georgiev, K.; Zlatev, Z.

    2010-11-01

    The Danish Eulerian Model (DEM) is an Eulerian model for studying the transport of air pollutants on large scale. Originally, the model was developed at the National Environmental Research Institute of Denmark. The model computational domain covers Europe and some neighbour parts belong to the Atlantic Ocean, Asia and Africa. If DEM model is to be applied by using fine grids, then its discretization leads to a huge computational problem. This implies that such a model as DEM must be run only on high-performance computer architectures. The implementation and tuning of such a complex large-scale model on each different computer is a non-trivial task. Here, some comparison results of running of this model on different kind of vector (CRAY C92A, Fujitsu, etc.), parallel computers with distributed memory (IBM SP, CRAY T3E, Beowulf clusters, Macintosh G4 clusters, etc.), parallel computers with shared memory (SGI Origin, SUN, etc.) and parallel computers with two levels of parallelism (IBM SMP, IBM BlueGene/P, clusters of multiprocessor nodes, etc.) will be presented. The main idea in the parallel version of DEM is domain partitioning approach. Discussions according to the effective use of the cache and hierarchical memories of the modern computers as well as the performance, speed-ups and efficiency achieved will be done. The parallel code of DEM, created by using MPI standard library, appears to be highly portable and shows good efficiency and scalability on different kind of vector and parallel computers. Some important applications of the computer model output are presented in short.

  9. Integrated Multiscale Modeling of Molecular Computing Devices

    Energy Technology Data Exchange (ETDEWEB)

    Jerzy Bernholc

    2011-02-03

    photolithography will some day reach a miniaturization limit, forcing designers of Si-based electronics to pursue increased performance by other means. Any other alternative approach would have the unenviable task of matching the ability of Si technology to pack more than a billion interconnected and addressable devices on a chip the size of a thumbnail. Nevertheless, the prospects of developing alternative approaches to fabricate electronic devices have spurred an ever-increasing pace of fundamental research. One of the promising possibilities is molecular electronics (ME), self-assembled molecular-based electronic systems composed of single-molecule devices in ultra dense, ultra fast molecular-sized components. This project focused on developing accurate, reliable theoretical modeling capabilities for describing molecular electronics devices. The participants in the project are given in Table 1. The primary outcomes of this fundamental computational science grant are publications in the open scientific literature. As listed below, 62 papers have been published from this project. In addition, the research has also been the subject of more than 100 invited talks at conferences, including several plenary or keynote lectures. Many of the goals of the original proposal were completed. Specifically, the multi-disciplinary group developed a unique set of capabilities and tools for investigating electron transport in fabricated and self-assembled nanostructures at multiple length and time scales.

  10. A stepped-care model of post-disaster child and adolescent mental health service provision

    Directory of Open Access Journals (Sweden)

    Brett M. McDermott

    2014-07-01

    Full Text Available Background: From a global perspective, natural disasters are common events. Published research highlights that a significant minority of exposed children and adolescents develop disaster-related mental health syndromes and associated functional impairment. Consistent with the considerable unmet need of children and adolescents with regard to psychopathology, there is strong evidence that many children and adolescents with post-disaster mental health presentations are not receiving adequate interventions. Objective: To critique existing child and adolescent mental health services (CAMHS models of care and the capacity of such models to deal with any post-disaster surge in clinical demand. Further, to detail an innovative service response; a child and adolescent stepped-care service provision model. Method: A narrative review of traditional CAMHS is presented. Important elements of a disaster response – individual versus community recovery, public health approaches, capacity for promotion and prevention and service reach are discussed and compared with the CAMHS approach. Results: Difficulties with traditional models of care are highlighted across all levels of intervention; from the ability to provide preventative initiatives to the capacity to provide intense specialised posttraumatic stress disorder interventions. In response, our over-arching stepped-care model is advocated. The general response is discussed and details of the three tiers of the model are provided: Tier 1 communication strategy, Tier 2 parent effectiveness and teacher training, and Tier 3 screening linked to trauma-focused cognitive behavioural therapy. Conclusion: In this paper, we argue that traditional CAMHS are not an appropriate model of care to meet the clinical needs of this group in the post-disaster setting. We conclude with suggestions how improved post-disaster child and adolescent mental health outcomes can be achieved by applying an innovative service approach.

  11. Alcohol, Sex, and Screens: Modeling Media Influence on Adolescent Alcohol and Sex Co-Occurrence.

    Science.gov (United States)

    Bleakley, Amy; Ellithorpe, Morgan E; Hennessy, Michael; Khurana, Atika; Jamieson, Patrick; Weitz, Ilana

    2017-02-26

    Alcohol use and sexual behavior are important risk behaviors in adolescent development, and combining the two is common. The reasoned action approach (RAA) is used to predict adolescents' intention to combine alcohol use and sexual behavior based on exposure to alcohol and sex combinations in popular entertainment media. We conducted a content analysis of mainstream (n = 29) and Black-oriented movies (n = 34) from 2014 and 2013-2014, respectively, and 56 television shows (2014-2015 season). Content analysis ratings featuring character portrayals of both alcohol and sex within the same five-minute segment were used to create exposure measures that were linked to online survey data collected from 1,990 adolescents ages 14 to 17 years old (50.3% Black, 49.7% White; 48.1% female). Structural equation modeling (SEM) and group analysis by race were used to test whether attitudes, norms, and perceived behavioral control mediated the effects of media exposure on intention to combine alcohol and sex. Results suggest that for both White and Black adolescents, exposure to media portrayals of alcohol and sex combinations is positively associated with adolescents' attitudes and norms. These relationships were stronger among White adolescents. Intention was predicted by attitude, norms, and control, but only the attitude-intention relationship was different by race group (stronger for Whites).

  12. Attachment-based family therapy for depressed and suicidal adolescents: theory, clinical model and empirical support.

    Science.gov (United States)

    Ewing, E Stephanie Krauthamer; Diamond, Guy; Levy, Suzanne

    2015-01-01

    Attachment-Based Family Therapy (ABFT) is a manualized family-based intervention designed for working with depressed adolescents, including those at risk for suicide, and their families. It is an empirically informed and supported treatment. ABFT has its theoretical underpinnings in attachment theory and clinical roots in structural family therapy and emotion focused therapies. ABFT relies on a transactional model that aims to transform the quality of adolescent-parent attachment, as a means of providing the adolescent with a more secure relationship that can support them during challenging times generally, and the crises related to suicidal thinking and behavior, specifically. This article reviews: (1) the theoretical foundations of ABFT (attachment theory, models of emotional development); (2) the ABFT clinical model, including training and supervision factors; and (3) empirical support.

  13. A Model Adolescent Substance-Abuse Treatment Program.

    Science.gov (United States)

    Copans, Stuart

    1993-01-01

    Describes two adolescent substance abuse treatment programs in New England psychiatric center: Osgood Three, which is no longer in existence, and Tyler Three, which replaced it and is struggling to grow. Considers transition from Osgood Three to Tyler Three, process of change, and learning what can be preserved from past and what must be…

  14. A Psychoecological Model of Academic Performance among Hispanic Adolescents

    Science.gov (United States)

    Chun, Heejung; Dickson, Ginger

    2011-01-01

    Although the number of students who complete high school continues to rise, dramatic differences in school success remain across racial/ethnic groups. The current study addressed Hispanic adolescents' academic performance by investigating the relationships of parental involvement, culturally responsive teaching, sense of school belonging, and…

  15. Engagement Models for Adolescents in DATOS-A.

    Science.gov (United States)

    Broome, Kirk M.; Joe, George W.; Simpson, D. Dwayne

    2001-01-01

    Examined relationships between patient background, treatment readiness, and therapeutic engagement in national sample of adolescents admitted to 20 treatment programs representing 3 modalities (residential, outpatient drug free, and short-term inpatient). Found that patients with higher treatment readiness at intake subsequently became more…

  16. Actor and Partner Effects of Adolescents' Romantic Working Models and Styles on Interactions with Romantic Partners

    Science.gov (United States)

    Furman, Wyndol; Simon, Valerie A.

    2006-01-01

    The present study examined how adolescents' and their romantic partners' romantic working models and relational styles were related to their interactions with each other. Sixty-five couples (M age=18.1 years) were observed interacting. Romantic working models were assessed in interviews about their romantic experiences; romantic styles were…

  17. Longitudinal and Integrative Tests of Family Stress Model Effects on Mexican Origin Adolescents

    Science.gov (United States)

    White, Rebecca M. B.; Liu, Yu; Nair, Rajni L.; Tein, Jenn-Yun

    2015-01-01

    The family stress model represents a common framework through which to examine the effects of environmental stressors on adolescent adjustment. The model suggests that economic and neighborhood stressors influence youth adjustment via disruptions to parenting. Incorporating integrative developmental theory, we examined the degree to which parents'…

  18. A Prospective Test of Cognitive Vulnerability Models of Depression with Adolescent Girls

    Science.gov (United States)

    Bohon, Cara; Stice, Eric; Burton, Emily; Fudell, Molly; Nolen-Hoeksema, Susan

    2008-01-01

    This study sought to provide a more rigorous prospective test of two cognitive vulnerability models of depression with longitudinal data from 496 adolescent girls. Results supported the cognitive vulnerability model in that stressors predicted future increases in depressive symptoms and onset of clinically significant major depression for…

  19. Understanding Chinese American Adolescents' Developmental Outcomes: Insights from the Family Stress Model

    Science.gov (United States)

    Benner, Aprile D.; Kim, Su Yeong

    2010-01-01

    In this brief report, we investigated whether the Family Stress Model could be replicated with a sample of Chinese American families. Path analyses with 444 adolescents and their parents provided support for the model's generalizability. Specifically, mothers' and fathers' reports of economic status (i.e., income, financial, and job instability)…

  20. A Moderated Mediation Model: Racial Discrimination, Coping Strategies, and Racial Identity among Black Adolescents

    Science.gov (United States)

    Seaton, Eleanor K.; Upton, Rachel; Gilbert, Adrianne; Volpe, Vanessa

    2014-01-01

    This study examined a moderated mediation model among 314 Black adolescents aged 13-18. The model included general coping strategies (e.g., active, distracting, avoidant, and support-seeking strategies) as mediators and racial identity dimensions (racial centrality, private regard, public regard, minority, assimilationist, and humanist ideologies)…

  1. Development of an adolescent inpatient sexual abuse group: application of Lewin's model of change.

    Science.gov (United States)

    Riddle, C R

    1994-01-01

    The development and implementation of an adolescent sexual abuse group on an inpatient psychiatric unit is described. Steps of Kurt Lewin's model of change are used as a framework for this planned change. Specific issues concerning group procedure and process are detailed. Recommendations for this group and broader use of the Lewin model are included.

  2. Overview of ASC Capability Computing System Governance Model

    Energy Technology Data Exchange (ETDEWEB)

    Doebling, Scott W. [Los Alamos National Laboratory

    2012-07-11

    This document contains a description of the Advanced Simulation and Computing Program's Capability Computing System Governance Model. Objectives of the Governance Model are to ensure that the capability system resources are allocated on a priority-driven basis according to the Program requirements; and to utilize ASC Capability Systems for the large capability jobs for which they were designed and procured.

  3. Python for Scientific Computing Education: Modeling of Queueing Systems

    Directory of Open Access Journals (Sweden)

    Vladimiras Dolgopolovas

    2014-01-01

    Full Text Available In this paper, we present the methodology for the introduction to scientific computing based on model-centered learning. We propose multiphase queueing systems as a basis for learning objects. We use Python and parallel programming for implementing the models and present the computer code and results of stochastic simulations.

  4. World Knowledge in Computational Models of Discourse Comprehension

    Science.gov (United States)

    Frank, Stefan L.; Koppen, Mathieu; Noordman, Leo G. M.; Vonk, Wietske

    2008-01-01

    Because higher level cognitive processes generally involve the use of world knowledge, computational models of these processes require the implementation of a knowledge base. This article identifies and discusses 4 strategies for dealing with world knowledge in computational models: disregarding world knowledge, "ad hoc" selection, extraction from…

  5. A Conceptual Model of Cultural Predictors of Anxiety among Japanese American and Part-Japanese American Adolescents.

    Science.gov (United States)

    Williams, John Kino Yamaguchi; Goebert, Deborah; Hishinuma, Earl; Miyamoto, Robin; Anzai, Neal; Izutsu, Satoru; Yanagida, Evelyn; Nishimura, Stephanie; Andrade, Naleen; Baker, F. M.

    2002-01-01

    Develops and assesses a model integrating Japanese ethnicity, cultural identity, and anxiety in Japanese American and part-Japanese American high school seniors. Japanese American adolescents scored higher on the scale and reported fewer anxiety symptoms than part-Japanese American adolescents. The model had a good overall fit, suggesting that…

  6. Many-Task Computing Tools for Multiscale Modeling

    OpenAIRE

    Katz, Daniel S.; Ripeanu, Matei; Wilde, Michael

    2011-01-01

    This paper discusses the use of many-task computing tools for multiscale modeling. It defines multiscale modeling and places different examples of it on a coupling spectrum, discusses the Swift parallel scripting language, describes three multiscale modeling applications that could use Swift, and then talks about how the Swift model is being extended to cover more of the multiscale modeling coupling spectrum.

  7. Pervasive Computing Location-aware Model Based on Ontology

    Institute of Scientific and Technical Information of China (English)

    PU Fang; CAI Hai-bin; CAO Qi-ying; SUN Dao-qing; LI Tong

    2008-01-01

    In order to integrate heterogeneous location-aware systems into pervasive computing environment, a novel pervasive computing location-aware model based on ontology is presented. A location-aware model ontology (LMO) is constructed. The location-aware model has the capabilities of sharing knowledge, reasoning and adjusting the usage policies of services dynamically through a unified semantic location manner. At last, the work process of our proposed location-aware model is explained by an application scenario.

  8. Computational intelligence applications in modeling and control

    CERN Document Server

    Vaidyanathan, Sundarapandian

    2015-01-01

    The development of computational intelligence (CI) systems was inspired by observable and imitable aspects of intelligent activity of human being and nature. The essence of the systems based on computational intelligence is to process and interpret data of various nature so that that CI is strictly connected with the increase of available data as well as capabilities of their processing, mutually supportive factors. Developed theories of computational intelligence were quickly applied in many fields of engineering, data analysis, forecasting, biomedicine and others. They are used in images and sounds processing and identifying, signals processing, multidimensional data visualization, steering of objects, analysis of lexicographic data, requesting systems in banking, diagnostic systems, expert systems and many other practical implementations. This book consists of 16 contributed chapters by subject experts who are specialized in the various topics addressed in this book. The special chapters have been brought ...

  9. A DNA based model for addition computation

    Institute of Scientific and Technical Information of China (English)

    GAO Lin; YANG Xiao; LIU Wenbin; XU Jin

    2004-01-01

    Much effort has been made to solve computing problems by using DNA-an organic simulating method, which in some cases is preferable to the current electronic computer. However, No one at present has proposed an effective and applicable method to solve addition problem with molecular algorithm due to the difficulty in solving the carry problem which can be easily solved by hardware of an electronic computer. In this article, we solved this problem by employing two kinds of DNA strings, one is called result and operation string while the other is named carrier. The result and operation string contains some carry information by its own and denotes the ultimate result while the carrier is just for carrying use. The significance of this algorithm is the original code, the fairly easy steps to follow and the feasibility under current molecular biological technology.

  10. Attacker Modelling in Ubiquitous Computing Systems

    DEFF Research Database (Denmark)

    Papini, Davide

    Within the last five to ten years we have experienced an incredible growth of ubiquitous technologies which has allowed for improvements in several areas, including energy distribution and management, health care services, border surveillance, secure monitoring and management of buildings......, localisation services and many others. These technologies can be classified under the name of ubiquitous systems. The term Ubiquitous System dates back to 1991 when Mark Weiser at Xerox PARC Lab first referred to it in writing. He envisioned a future where computing technologies would have been melted...... in with our everyday life. This future is visible to everyone nowadays: terms like smartphone, cloud, sensor, network etc. are widely known and used in our everyday life. But what about the security of such systems. Ubiquitous computing devices can be limited in terms of energy, computing power and memory...

  11. A computational model of the human hand 93-ERI-053

    Energy Technology Data Exchange (ETDEWEB)

    Hollerbach, K.; Axelrod, T.

    1996-03-01

    The objectives of the Computational Hand Modeling project were to prove the feasibility of the Laboratory`s NIKE3D finite element code to orthopaedic problems. Because of the great complexity of anatomical structures and the nonlinearity of their behavior, we have focused on a subset of joints of the hand and lower extremity and have developed algorithms to model their behavior. The algorithms developed here solve fundamental problems in computational biomechanics and can be expanded to describe any other joints of the human body. This kind of computational modeling has never successfully been attempted before, due in part to a lack of biomaterials data and a lack of computational resources. With the computational resources available at the National Laboratories and the collaborative relationships we have established with experimental and other modeling laboratories, we have been in a position to pursue our innovative approach to biomechanical and orthopedic modeling.

  12. Some challenges for the triadic model for the study of adolescent motivated behavior.

    Science.gov (United States)

    Luciana, Monica; Segalowitz, Sidney J

    2014-08-01

    Within this special issue, Ernst has provided a comprehensive overview of the triadic neural systems model and its explanatory power for the conceptualization of adolescent development. Within this commentary, we encourage further consideration of several issues as this valuable model is expanded and articulated. These issues include the extent of functional distinctions among the three proposed neural nodes that comprise the triadic framework, the proposed dichotomy between motivation and emotion as linked to approach versus avoidance, the extent to which approach and avoidance can be dissociated on behavioral and neural levels during adolescent development, and how individual difference factors mechanistically interact with broader age-based developmental trends.

  13. A Swarm Intelligence Based Model for Mobile Cloud Computing

    Directory of Open Access Journals (Sweden)

    Ahmed S. Salama

    2015-01-01

    Full Text Available Mobile Computing (MC provides multi services and a lot of advantages for millions of users across the world over the internet. Millions of business customers have leveraged cloud computing services through mobile devices to get what is called Mobile Cloud Computing (MCC. MCC aims at using cloud computing techniques for storage and processing of data on mobile devices, thereby reducing their limitations. This paper proposes architecture for a Swarm Intelligence Based Mobile Cloud Computing Model (SIBMCCM. A model that uses a proposed Parallel Particle Swarm Optimization (PPSO algorithm to enhance the access time for the mobile cloud computing services which support different E Commerce models and to better secure the communication through the mobile cloud and the mobile commerce transactions.

  14. Mathematical modeling and computational intelligence in engineering applications

    CERN Document Server

    Silva Neto, Antônio José da; Silva, Geraldo Nunes

    2016-01-01

    This book brings together a rich selection of studies in mathematical modeling and computational intelligence, with application in several fields of engineering, like automation, biomedical, chemical, civil, electrical, electronic, geophysical and mechanical engineering, on a multidisciplinary approach. Authors from five countries and 16 different research centers contribute with their expertise in both the fundamentals and real problems applications based upon their strong background on modeling and computational intelligence. The reader will find a wide variety of applications, mathematical and computational tools and original results, all presented with rigorous mathematical procedures. This work is intended for use in graduate courses of engineering, applied mathematics and applied computation where tools as mathematical and computational modeling, numerical methods and computational intelligence are applied to the solution of real problems.

  15. CHOREO: An Interactive Computer Model for Dance.

    Science.gov (United States)

    Savage, G. J.; Officer, J. M.

    1978-01-01

    Establishes the need for literacy in dance; and describes two dance notation systems: the Massine notation method, and the Labanotation method. The use of interactive computer graphics as a tool for both learning and interpreting dance notation is introduced. (Author/VT)

  16. An integrated introduction to computer graphics and geometric modeling

    CERN Document Server

    Goldman, Ronald

    2009-01-01

    … this book may be the first book on geometric modelling that also covers computer graphics. In addition, it may be the first book on computer graphics that integrates a thorough introduction to 'freedom' curves and surfaces and to the mathematical foundations for computer graphics. … the book is well suited for an undergraduate course. … The entire book is very well presented and obviously written by a distinguished and creative researcher and educator. It certainly is a textbook I would recommend. …-Computer-Aided Design, 42, 2010… Many books concentrate on computer programming and soon beco

  17. Integrating Cloud-Computing-Specific Model into Aircraft Design

    Science.gov (United States)

    Zhimin, Tian; Qi, Lin; Guangwen, Yang

    Cloud Computing is becoming increasingly relevant, as it will enable companies involved in spreading this technology to open the door to Web 3.0. In the paper, the new categories of services introduced will slowly replace many types of computational resources currently used. In this perspective, grid computing, the basic element for the large scale supply of cloud services, will play a fundamental role in defining how those services will be provided. The paper tries to integrate cloud computing specific model into aircraft design. This work has acquired good results in sharing licenses of large scale and expensive software, such as CFD (Computational Fluid Dynamics), UG, CATIA, and so on.

  18. SmartShadow models and methods for pervasive computing

    CERN Document Server

    Wu, Zhaohui

    2013-01-01

    SmartShadow: Models and Methods for Pervasive Computing offers a new perspective on pervasive computing with SmartShadow, which is designed to model a user as a personality ""shadow"" and to model pervasive computing environments as user-centric dynamic virtual personal spaces. Just like human beings' shadows in the physical world, it follows people wherever they go, providing them with pervasive services. The model, methods, and software infrastructure for SmartShadow are presented and an application for smart cars is also introduced.  The book can serve as a valuable reference work for resea

  19. Computer-aided design–computer-aided engineering associative feature-based heterogeneous object modeling

    Directory of Open Access Journals (Sweden)

    Jikai Liu

    2015-12-01

    Full Text Available Conventionally, heterogeneous object modeling methods paid limited attention to the concurrent modeling of geometry design and material composition distribution. Procedural method was normally employed to generate the geometry first and then determine the heterogeneous material distribution, which ignores the mutual influence. Additionally, limited capability has been established about irregular material composition distribution modeling with strong local discontinuities. This article overcomes these limitations by developing the computer-aided design–computer-aided engineering associative feature-based heterogeneous object modeling method. Level set functions are applied to model the geometry within computer-aided design module, which enables complex geometry modeling. Finite element mesh is applied to store the local material compositions within computer-aided engineering module, which allows any local discontinuities. Then, the associative feature concept builds the correspondence relationship between these modules. Additionally, the level set geometry and material optimization method are developed to concurrently generate the geometry and material information which fills the contents of the computer-aided design–computer-aided engineering associative feature model. Micro-geometry is investigated as well, instead of only the local material composition. A few cases are studied to prove the effectiveness of this new heterogeneous object modeling method.

  20. Counterconformity: an attribution model of adolescents' uniqueness-seeking behaviors in dressing.

    Science.gov (United States)

    Ling, I-Ling

    2008-01-01

    This article explores how an attribution model will illustrate uniqueness-seeking behavior in dressing in the Taiwanese adolescent subculture. The study employed 443 senior high school students. Results show that the tendency of uniqueness-seeking behavior in dressing is moderate. However, using cluster analysis to segment the counterconformity behavior of the subjects, the study demonstrates that there are two conspicuous types of segmentation "markets": rubber stamp and self-determined. The attribution models investigate the susceptibilities to informational and normative influence which have different direction impacts and weights on the adolescents' counterconformity behavior. More interestingly, path analyses indicate that consumer self-confidence mediates the relationship between informational influence and counterconformity behavior only on the rubber stamp type. This study then discusses how the adolescent consumers' need for uniqueness could be used in better understanding consumer behavior and the role consumption plays in their expression of identity.

  1. Macro—Dataflow Computational Model and Its Simulation

    Institute of Scientific and Technical Information of China (English)

    孙昱东; 谢志良

    1990-01-01

    This paper discusses the relationship between parallelism granularity and system overhead of dataflow computer systems,and indicates that a trade-off between them should be determined to obtain optimal efficiency of the overall system.On the basis of this discussion,a macro-dataflow computational model is established to exploit the task-level parallelism.Working as a macro-dataflow computer,an Experimental Distributed Dataflow Simulation System(EDDSS)is developed to examine the effectiveness of the macro-dataflow computational model.

  2. Computer modeling of ORNL storage tank sludge mobilization and mixing

    Energy Technology Data Exchange (ETDEWEB)

    Terrones, G.; Eyler, L.L.

    1993-09-01

    This report presents and analyzes the results of the computer modeling of mixing and mobilization of sludge in horizontal, cylindrical storage tanks using submerged liquid jets. The computer modeling uses the TEMPEST computational fluid dynamics computer program. The horizontal, cylindrical storage tank configuration is similar to the Melton Valley Storage Tanks (MVST) at Oak Ridge National (ORNL). The MVST tank contents exhibit non-homogeneous, non-Newtonian rheology characteristics. The eventual goals of the simulations are to determine under what conditions sludge mobilization using submerged liquid jets is feasible in tanks of this configuration, and to estimate mixing times required to approach homogeneity of the contents of the tanks.

  3. Implementing and assessing computational modeling in introductory mechanics

    Science.gov (United States)

    Caballero, Marcos D.; Kohlmyer, Matthew A.; Schatz, Michael F.

    2012-12-01

    Students taking introductory physics are rarely exposed to computational modeling. In a one-semester large lecture introductory calculus-based mechanics course at Georgia Tech, students learned to solve physics problems using the VPython programming environment. During the term, 1357 students in this course solved a suite of 14 computational modeling homework questions delivered using an online commercial course management system. Their proficiency with computational modeling was evaluated with a proctored assignment involving a novel central force problem. The majority of students (60.4%) successfully completed the evaluation. Analysis of erroneous student-submitted programs indicated that a small set of student errors explained why most programs failed. We discuss the design and implementation of the computational modeling homework and evaluation, the results from the evaluation, and the implications for computational instruction in introductory science, technology, engineering, and mathematics (STEM) courses.

  4. Models of parallel computation :a survey and classification

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yunquan; CHEN Guoliang; SUN Guangzhong; MIAO Qiankun

    2007-01-01

    In this paper,the state-of-the-art parallel computational model research is reviewed.We will introduce various models that were developed during the past decades.According to their targeting architecture features,especially memory organization,we classify these parallel computational models into three generations.These models and their characteristics are discussed based on three generations classification.We believe that with the ever increasing speed gap between the CPU and memory systems,incorporating non-uniform memory hierarchy into computational models will become unavoidable.With the emergence of multi-core CPUs,the parallelism hierarchy of current computing platforms becomes more and more complicated.Describing this complicated parallelism hierarchy in future computational models becomes more and more important.A semi-automatic toolkit that can extract model parameters and their values on real computers can reduce the model analysis complexity,thus allowing more complicated models with more parameters to be adopted.Hierarchical memory and hierarchical parallelism will be two very important features that should be considered in future model design and research.

  5. Validation of a multifactorial risk factor model used for predicting future caries risk with nevada adolescents

    Directory of Open Access Journals (Sweden)

    Mobley Connie

    2011-05-01

    Full Text Available Abstract Background The objective of this study was to measure the validity and reliability of a multifactorial Risk Factor Model developed for use in predicting future caries risk in Nevada adolescents in a public health setting. Methods This study examined retrospective data from an oral health surveillance initiative that screened over 51,000 students 13-18 years of age, attending public/private schools in Nevada across six academic years (2002/2003-2007/2008. The Risk Factor Model included ten demographic variables: exposure to fluoridation in the municipal water supply, environmental smoke exposure, race, age, locale (metropolitan vs. rural, tobacco use, Body Mass Index, insurance status, sex, and sealant application. Multiple regression was used in a previous study to establish which significantly contributed to caries risk. Follow-up logistic regression ascertained the weight of contribution and odds ratios of the ten variables. Researchers in this study computed sensitivity, specificity, positive predictive value (PVP, negative predictive value (PVN, and prevalence across all six years of screening to assess the validity of the Risk Factor Model. Results Subjects' overall mean caries prevalence across all six years was 66%. Average sensitivity across all six years was 79%; average specificity was 81%; average PVP was 89% and average PVN was 67%. Conclusions Overall, the Risk Factor Model provided a relatively constant, valid measure of caries that could be used in conjunction with a comprehensive risk assessment in population-based screenings by school nurses/nurse practitioners, health educators, and physicians to guide them in assessing potential future caries risk for use in prevention and referral practices.

  6. Operation of the computer model for microenvironment atomic oxygen exposure

    Science.gov (United States)

    Bourassa, R. J.; Gillis, J. R.; Gruenbaum, P. E.

    1995-01-01

    A computer model for microenvironment atomic oxygen exposure has been developed to extend atomic oxygen modeling capability to include shadowing and reflections. The model uses average exposure conditions established by the direct exposure model and extends the application of these conditions to treat surfaces of arbitrary shape and orientation.

  7. Computer Modeling for Optical Waveguide Sensors.

    Science.gov (United States)

    1987-12-15

    COSATI CODES 18 SUBJECT TERMS (Continue on reverse it necessary and cleritify by DIock numnerl FIEL GRUP SB-GOUP Optical waveguide sensors Computer...reflection. The resultant probe beam transmission may be plotted as a function of changes in the refractive index of the surrounding fluid medium. BASIC...all angles of incidence about the critical angle ecr. It should be noted that N in equation (3) is a function of e, since = sin - l sin 8 , see

  8. A Computational Dual-Process Model of Social Interaction

    Science.gov (United States)

    2014-01-30

    AFRL-RH-WP-TR-2014-0123       A COMPUTATIONAL DUAL- PROCESS MODEL OF SOCIAL INTERACTION Stephen Deutsch BBN Technologies 10 Moulton...From – To) 01 January 2012 – 01 January 2014 4. TITLE AND SUBTITLE A Computational Dual- Process Model of Social Interaction 5a. CONTRACT NUMBER...88ABW-2014-5663; Cleared 3 December 2014 14. ABSTRACT (Maximum 200 words) Dual- process models postulate two distinct modes of information processing

  9. Introduction to computation and modeling for differential equations

    CERN Document Server

    Edsberg, Lennart

    2008-01-01

    An introduction to scientific computing for differential equationsIntroduction to Computation and Modeling for Differential Equations provides a unified and integrated view of numerical analysis, mathematical modeling in applications, and programming to solve differential equations, which is essential in problem-solving across many disciplines, such as engineering, physics, and economics. This book successfully introduces readers to the subject through a unique ""Five-M"" approach: Modeling, Mathematics, Methods, MATLAB, and Multiphysics. This approach facilitates a thorough understanding of h

  10. Computational modeling of induced emotion using GEMS

    NARCIS (Netherlands)

    Aljanaki, Anna; Wiering, Frans; Veltkamp, Remco

    2014-01-01

    Most researchers in the automatic music emotion recognition field focus on the two-dimensional valence and arousal model. This model though does not account for the whole diversity of emotions expressible through music. Moreover, in many cases it might be important to model induced (felt) emotion, r

  11. Computational neurorehabilitation: modeling plasticity and learning to predict recovery.

    Science.gov (United States)

    Reinkensmeyer, David J; Burdet, Etienne; Casadio, Maura; Krakauer, John W; Kwakkel, Gert; Lang, Catherine E; Swinnen, Stephan P; Ward, Nick S; Schweighofer, Nicolas

    2016-01-01

    Despite progress in using computational approaches to inform medicine and neuroscience in the last 30 years, there have been few attempts to model the mechanisms underlying sensorimotor rehabilitation. We argue that a fundamental understanding of neurologic recovery, and as a result accurate predictions at the individual level, will be facilitated by developing computational models of the salient neural processes, including plasticity and learning systems of the brain, and integrating them into a context specific to rehabilitation. Here, we therefore discuss Computational Neurorehabilitation, a newly emerging field aimed at modeling plasticity and motor learning to understand and improve movement recovery of individuals with neurologic impairment. We first explain how the emergence of robotics and wearable sensors for rehabilitation is providing data that make development and testing of such models increasingly feasible. We then review key aspects of plasticity and motor learning that such models will incorporate. We proceed by discussing how computational neurorehabilitation models relate to the current benchmark in rehabilitation modeling - regression-based, prognostic modeling. We then critically discuss the first computational neurorehabilitation models, which have primarily focused on modeling rehabilitation of the upper extremity after stroke, and show how even simple models have produced novel ideas for future investigation. Finally, we conclude with key directions for future research, anticipating that soon we will see the emergence of mechanistic models of motor recovery that are informed by clinical imaging results and driven by the actual movement content of rehabilitation therapy as well as wearable sensor-based records of daily activity.

  12. Computational technology of multiscale modeling the gas flows in microchannels

    Science.gov (United States)

    Podryga, V. O.

    2016-11-01

    The work is devoted to modeling the gas mixture flows in engineering microchannels under conditions of many scales of computational domain. The computational technology of using the multiscale approach combining macro - and microscopic models is presented. At macrolevel the nature of the flow and the external influence on it are considered. As a model the system of quasigasdynamic equations is selected. At microlevel the correction of gasdynamic parameters and the determination of boundary conditions are made. As a numerical model the Newton's equations and the molecular dynamics method are selected. Different algorithm types used for implementation of multiscale modeling are considered. The results of the model problems for separate stages are given.

  13. Markov Graph Model Computation and Its Application to Intrusion Detection

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Markov model is usually selected as the base model of user action in the intrusion detection system (IDS). However, the performance of the IDS depends on the status space of Markov model and it will degrade as the space dimension grows. Here, Markov Graph Model (MGM) is proposed to handle this issue. Specification of the model is described, and several methods for probability computation with MGM are also presented. Based on MGM,algorithms for building user model and predicting user action are presented. And the performance of these algorithms such as computing complexity, prediction accuracy, and storage requirement of MGM are analyzed.

  14. Establishing a Cloud Computing Success Model for Hospitals in Taiwan

    Directory of Open Access Journals (Sweden)

    Jiunn-Woei Lian PhD

    2017-01-01

    Full Text Available The purpose of this study is to understand the critical quality-related factors that affect cloud computing success of hospitals in Taiwan. In this study, private cloud computing is the major research target. The chief information officers participated in a questionnaire survey. The results indicate that the integration of trust into the information systems success model will have acceptable explanatory power to understand cloud computing success in the hospital. Moreover, information quality and system quality directly affect cloud computing satisfaction, whereas service quality indirectly affects the satisfaction through trust. In other words, trust serves as the mediator between service quality and satisfaction. This cloud computing success model will help hospitals evaluate or achieve success after adopting private cloud computing health care services.

  15. Establishing a Cloud Computing Success Model for Hospitals in Taiwan.

    Science.gov (United States)

    Lian, Jiunn-Woei

    2017-01-01

    The purpose of this study is to understand the critical quality-related factors that affect cloud computing success of hospitals in Taiwan. In this study, private cloud computing is the major research target. The chief information officers participated in a questionnaire survey. The results indicate that the integration of trust into the information systems success model will have acceptable explanatory power to understand cloud computing success in the hospital. Moreover, information quality and system quality directly affect cloud computing satisfaction, whereas service quality indirectly affects the satisfaction through trust. In other words, trust serves as the mediator between service quality and satisfaction. This cloud computing success model will help hospitals evaluate or achieve success after adopting private cloud computing health care services.

  16. Overweight and television and computer habits in Swedish school-age children and adolescents: a cross-sectional study.

    Science.gov (United States)

    Garmy, Pernilla; Clausson, Eva K; Nyberg, Per; Jakobsson, Ulf

    2014-06-01

    The aim of this cross-sectional study was to investigate the prevalence of overweight and obesity in children and adolescents (6-16 years), and relationships between being overweight and sleep, experiencing of fatigue, enjoyment of school, and time spent in watching television and in sitting at the computer. Trained school nurses measured the weight and height of 2891 children aged 6, 7, 10, 14, and 16, and distributed a questionnaire to them regarding television and computer habits, sleep, and enjoyment of school. Overweight, obesity included, was present in 16.1% of the study population. Relationships between lifestyle factors and overweight were studied using multivariate logistic regression analysis. Having a bedroom television and spending more than 2 h a day watching television were found to be associated with overweight (OR 1.26 and 1.55 respectively). No association was found between overweight and time spent at the computer, short sleep duration, enjoyment of school, tiredness at school, or difficulties in sleeping and waking up. It is recommended that the school health service discuss with pupils their media habits so as to promote their maintaining a healthy lifestyle.

  17. Mobile Cloud Computing: A Comparison of Application Models

    CERN Document Server

    Kovachev, Dejan; Klamma, Ralf

    2011-01-01

    Cloud computing is an emerging concept combining many fields of computing. The foundation of cloud computing is the delivery of services, software and processing capacity over the Internet, reducing cost, increasing storage, automating systems, decoupling of service delivery from underlying technology, and providing flexibility and mobility of information. However, the actual realization of these benefits is far from being achieved for mobile applications and open many new research questions. In order to better understand how to facilitate the building of mobile cloud-based applications, we have surveyed existing work in mobile computing through the prism of cloud computing principles. We give a definition of mobile cloud coputing and provide an overview of the results from this review, in particular, models of mobile cloud applications. We also highlight research challenges in the area of mobile cloud computing. We conclude with recommendations for how this better understanding of mobile cloud computing can ...

  18. Numerical computations and mathematical modelling with infinite and infinitesimal numbers

    CERN Document Server

    Sergeyev, Yaroslav D

    2012-01-01

    Traditional computers work with finite numbers. Situations where the usage of infinite or infinitesimal quantities is required are studied mainly theoretically. In this paper, a recently introduced computational methodology (that is not related to the non-standard analysis) is used to work with finite, infinite, and infinitesimal numbers \\textit{numerically}. This can be done on a new kind of a computer - the Infinity Computer - able to work with all these types of numbers. The new computational tools both give possibilities to execute computations of a new type and open new horizons for creating new mathematical models where a computational usage of infinite and/or infinitesimal numbers can be useful. A number of numerical examples showing the potential of the new approach and dealing with divergent series, limits, probability theory, linear algebra, and calculation of volumes of objects consisting of parts of different dimensions are given.

  19. The Validation of Computer-based Models in Engineering: Some Lessons from Computing Science

    Directory of Open Access Journals (Sweden)

    D. J. Murray-Smith

    2001-01-01

    Full Text Available Questions of the quality of computer-based models and the formal processes of model testing, involving internal verification and external validation, are usually given only passing attention in engineering reports and in technical publications. However, such models frequently provide a basis for analysis methods, design calculations or real-time decision-making in complex engineering systems. This paper reviews techniques used for external validation of computer-based models and contrasts the somewhat casual approach which is usually adopted in this field with the more formal approaches to software testing and documentation recommended for large software projects. Both activities require intimate knowledge of the intended application, a systematic approach and considerable expertise and ingenuity in the design of tests. It is concluded that engineering degree courses dealing with modelling techniques and computer simulation should put more emphasis on model limitations, testing and validation.

  20. Performance Predictable ServiceBSP Model for Grid Computing

    Institute of Scientific and Technical Information of China (English)

    TONG Weiqin; MIAO Weikai

    2007-01-01

    This paper proposes a performance prediction model for grid computing model ServiceBSP to support developing high quality applications in grid environment. In ServiceBSP model,the agents carrying computing tasks are dispatched to the local domain of the selected computation services. By using the IP (integer program) approach, the Service Selection Agent selects the computation services with global optimized QoS (quality of service) consideration. The performance of a ServiceBSP application can be predicted according to the performance prediction model based on the QoS of the selected services. The performance prediction model can help users to analyze their applications and improve them by optimized the factors which affects the performance. The experiment shows that the Service Selection Agent can provide ServiceBSP users with satisfied QoS of applications.

  1. Robust speech features representation based on computational auditory model

    Institute of Scientific and Technical Information of China (English)

    LU Xugang; JIA Chuan; DANG Jianwu

    2004-01-01

    A speech signal processing and features extracting method based on computational auditory model is proposed. The computational model is based on psychological, physiological knowledge and digital signal processing methods. In each stage of a hearing perception system, there is a corresponding computational model to simulate its function. Based on this model, speech features are extracted. In each stage, the features in different kinds of level are extracted. A further processing for primary auditory spectrum based on lateral inhibition is proposed to extract much more robust speech features. All these features can be regarded as the internal representations of speech stimulation in hearing system. The robust speech recognition experiments are conducted to test the robustness of the features. Results show that the representations based on the proposed computational auditory model are robust representations for speech signals.

  2. The Architectural Designs of a Nanoscale Computing Model

    Directory of Open Access Journals (Sweden)

    Mary M. Eshaghian-Wilner

    2004-08-01

    Full Text Available A generic nanoscale computing model is presented in this paper. The model consists of a collection of fully interconnected nanoscale computing modules, where each module is a cube of cells made out of quantum dots, spins, or molecules. The cells dynamically switch between two states by quantum interactions among their neighbors in all three dimensions. This paper includes a brief introduction to the field of nanotechnology from a computing point of view and presents a set of preliminary architectural designs for fabricating the nanoscale model studied.

  3. Transforming High School Physics with Modeling and Computation

    CERN Document Server

    Aiken, John M

    2013-01-01

    The Engage to Excel (PCAST) report, the National Research Council's Framework for K-12 Science Education, and the Next Generation Science Standards all call for transforming the physics classroom into an environment that teaches students real scientific practices. This work describes the early stages of one such attempt to transform a high school physics classroom. Specifically, a series of model-building and computational modeling exercises were piloted in a ninth grade Physics First classroom. Student use of computation was assessed using a proctored programming assignment, where the students produced and discussed a computational model of a baseball in motion via a high-level programming environment (VPython). Student views on computation and its link to mechanics was assessed with a written essay and a series of think-aloud interviews. This pilot study shows computation's ability for connecting scientific practice to the high school science classroom.

  4. Computational modeling of shallow geothermal systems

    CERN Document Server

    Al-Khoury, Rafid

    2011-01-01

    A Step-by-step Guide to Developing Innovative Computational Tools for Shallow Geothermal Systems Geothermal heat is a viable source of energy and its environmental impact in terms of CO2 emissions is significantly lower than conventional fossil fuels. Shallow geothermal systems are increasingly utilized for heating and cooling of buildings and greenhouses. However, their utilization is inconsistent with the enormous amount of energy available underneath the surface of the earth. Projects of this nature are not getting the public support they deserve because of the uncertainties associated with

  5. Computational modeling in cognitive science: a manifesto for change.

    Science.gov (United States)

    Addyman, Caspar; French, Robert M

    2012-07-01

    Computational modeling has long been one of the traditional pillars of cognitive science. Unfortunately, the computer models of cognition being developed today have not kept up with the enormous changes that have taken place in computer technology and, especially, in human-computer interfaces.  For all intents and purposes, modeling is still done today as it was 25, or even 35, years ago. Everyone still programs in his or her own favorite programming language, source code is rarely made available, accessibility of models to non-programming researchers is essentially non-existent, and even for other modelers, the profusion of source code in a multitude of programming languages, written without programming guidelines, makes it almost impossible to access, check, explore, re-use, or continue to develop. It is high time to change this situation, especially since the tools are now readily available to do so. We propose that the modeling community adopt three simple guidelines that would ensure that computational models would be accessible to the broad range of researchers in cognitive science. We further emphasize the pivotal role that journal editors must play in making computational models accessible to readers of their journals.

  6. Tobacco use among adolescent students and the influence of role models

    Directory of Open Access Journals (Sweden)

    Sharma Rahul

    2010-01-01

    Full Text Available Background: Seventy per cent of premature deaths among adults are due to behavioral patterns that emerge in adolescence, including smoking. Objective: The objective was to study the prevalence of tobacco use among adolescent students in South Delhi and its epidemiological correlates. Materials and Methods: This was a cross-sectional study. Setting: Three schools and two colleges of South Delhi were chosen. There were 550 adolescent students aged 14-19. Statistical Analysis: Statistical analysis was done using proportions, the chi-square test, and multivariate logistic regression. Results: A total of 88 (16.0% students reported having ever tried cigarette or bidi smoking. The prevalence of current smoking was 7.1%. Exactly 10% (55 of the students reported having ever used smokeless forms of tobacco. The prevalence of tobacco use overall was found to be 20.9%, and was significantly higher (P=0.016 among the males than the females. Tobacco use was found to be significantly associated with having seen a brother/sister smoke (OR 5.15, best friend smoke (OR 2.92, and belonging to a nuclear family (OR 1.96. Conclusions: Tobacco use is still an important risk behavior among adolescent students. This study found a strong association of tobacco use by the adolescents with their having seen various role models ever smoking.

  7. The Metacognitive Model of Generalized Anxiety Disorder in Children and Adolescents

    Science.gov (United States)

    Ellis, Danielle M.; Hudson, Jennifer L.

    2010-01-01

    Worry is a common phenomenon in children and adolescents, with some experiencing excessive worries that cause significant distress and interference. The metacognitive model of generalized anxiety disorder (Wells 1995, 2009) was developed to explain cognitive processes associated with pathological worry in adults, particularly the role of positive…

  8. Depression amongst Chinese Adolescents in Hong Kong: An Evaluation of a Stress Moderation Model

    Science.gov (United States)

    Ng, Catalina S. M.; Hurry, Jane

    2011-01-01

    Stress has an established association with depression. However, not all adolescents experiencing stressors become depressed and it is helpful to identify potential resilience factors. The current study tests a theoretical extension of a stress-diathesis model of depression in a Chinese context, with stress, coping, family relationships, and…

  9. Facebook and the Cognitive Model: A Tool for Promoting Adolescent Self-Awareness

    Science.gov (United States)

    Lewis, Lucy; Wahesh, Edward

    2012-01-01

    A homework activity incorporating the social networking site Facebook is presented as a tool for teaching adolescent clients about the cognitive model and increasing their ability to identify and modify problematic thinking. The authors describe how a worksheet developed to help clients examine information presented on their Facebook profile can…

  10. The Relationship between Social Anxiety and Social Support in Adolescents: A Test of Competing Causal Models

    Science.gov (United States)

    Calsyn, Robert J.; Winter, Joel P.; Burger, Gary K.

    2005-01-01

    This study compared the strength of competing causal models in explaining the relationship between perceived support, enacted support, and social anxiety in adolescents. The social causation hypothesis postulates that social support causes social anxiety, whereas the social selection hypothesis postulates that social anxiety causes social support.…

  11. Testing Structural Models of DSM-IV Symptoms of Common Forms of Child and Adolescent Psychopathology

    Science.gov (United States)

    Lahey, Benjamin B.; Rathouz, Paul J.; Van Hulle, Carol; Urbano, Richard C.; Krueger, Robert F.; Applegate, Brooks; Garriock, Holly A.; Chapman, Derek A.; Waldman, Irwin D.

    2008-01-01

    Confirmatory factor analyses were conducted of "Diagnostic and Statistical Manual of Mental Disorders", Fourth Edition (DSM-IV) symptoms of common mental disorders derived from structured interviews of a representative sample of 4,049 twin children and adolescents and their adult caretakers. A dimensional model based on the assignment of symptoms…

  12. Towards a Model of Suicidal Ideation for Hong Kong Chinese Adolescents

    Science.gov (United States)

    Sun, Rachel C. F.; Hui, Eadaoin K. P.; Watkins, David

    2006-01-01

    This study tested a model of suicidal ideation with family cohesion, expressiveness, conflicts, teacher support, teacher-student relationships and peer support as antecedents, and self-esteem and depression as mediators. Data was collected from survey questionnaires with 433 Hong Kong Chinese adolescents. The results showed that only family…

  13. A Multi-Dimensional Model of Groupwork for Adolescent Girls Who Have Been Sexually Abused.

    Science.gov (United States)

    Lindon, Jillian; Nourse, Carol A.

    1994-01-01

    A treatment approach for sexually abused adolescent girls, using a group work model, incorporated three treatment modalities: a skills component, a psychotherapeutic component, and an educative component. Abused girls demonstrated difficulties in many areas of their lives. The six participants showed improvement according to self-statements and…

  14. Parental Support, Coping Strategies, and Psychological Adjustment: An Integrative Model with Late Adolescents.

    Science.gov (United States)

    Holahan, Charles J.; And Others

    1995-01-01

    An integrative predictive model was applied to responses of 241 college freshmen to examine interrelationships among parental support, adaptive coping strategies, and psychological adjustment. Social support from both parents and a nonconflictual parental relationship were positively associated with adolescents' psychological adjustment. (SLD)

  15. Online communication among adolescents: An integrated model on its attraction, opportunities, and risks.

    NARCIS (Netherlands)

    Valkenburg, P.M.; Peter, J.

    2011-01-01

    Adolescents far outnumber adults in their use of e-communication technologies, such as instant messaging and social network sites. In this article, we present an integrative model that helps us to understand both the appeal of these technologies and their risks and opportunities for the psychosocial

  16. An Examination of the Dual Model of Perfectionism and Adolescent Athlete Burnout: A Short-Term Longitudinal Research

    Science.gov (United States)

    Chen, Lung Hung; Kee, Ying Hwa; Tsai, Ying-Mei

    2009-01-01

    The dual model of perfectionism (Slade and Owens, Behav Modificat 22(3):372-390, 1998) is adopted to examine the influence of adaptive and maladaptive perfectionism on adolescent athlete burnout in Taiwan. Participants were 188 high school adolescent student-athletes (M = 16.48, SD = 0.59). They were administered the Multidimensional Inventory of…

  17. When Two Isn't Better than One: Predictors of Early Sexual Activity in Adolescence Using a Cumulative Risk Model

    Science.gov (United States)

    Price, Myeshia N.; Hyde, Janet Shibley

    2009-01-01

    This study explored factors that may be associated with early initiation of sexual activity among adolescents. Using the cumulative risk model, we hypothesized that as exposure to risk factors increases, so does the likelihood of early sexual debut. A sample of 273 (53% girls, 90% European American) adolescents was followed longitudinally from age…

  18. A Computational Trust Model for Collaborative Ventures

    Directory of Open Access Journals (Sweden)

    Weigang Wang

    2012-01-01

    Full Text Available Problem statement: The conceptual notion of trust and its underlying computational methods has been an important issue for researchers in electronic communities. While the independent trust evaluation is suitable in certain circumstances, such unilateral process falls short in supporting mutual evaluation between partners. Perceived reputation, the depth and breadth of trust, Trust Perception (TP, Repeat Collaborators at a Threshold (RCT and a collective trust index (c index have all been defined to specify the optimal trust criteria. Approach: By taking the evaluator’s own trust level as a threshold to identify compatible partners, a mutual balance between excess and deficiency in trust has been addressed. Since the number of repeated collaborations which signify retested confidence is more straightforward to capture than the manually provided feedback ratings, we have developed computational definitions for the above-mentioned concepts. Results and Conclusion: The results from the experiments based on the eBay dataset shows that the c index can be used to classify PowerSellers into normally distributed and comprehensible categories that can facilitate mutual evaluation.

  19. A model of adolescents' seeking of sexual content in their media choices.

    Science.gov (United States)

    Bleakley, Amy; Hennessy, Michael; Fishbein, Martin

    2011-07-01

    This article reports on the extent to which adolescents report actively seeking sexual content in media, identifies from which media they report seeking, estimates the association between seeking sexual information and romantic and sexual behavior, and shows that active seeking of sexual content in media sources is explained by an intention to seek such content using the Integrative Model of Behavioral Prediction, a reasoned action approach. The data are a national sample of 810 adolescents aged 13 to 18 years. Results show that 50% of adolescents reported actively seeking sexual content in their media choices, which included movies, television, music, Internet pornography sites, and magazines. Males sought sex content more than females, and gender differences were greatest for seeking from Internet pornography sites, movies, and television. Path analysis demonstrate that seeking sexual content is well-predicted by intentions to seek, and intentions are primarily driven by perceived normative pressure to seek sexual content.

  20. Hero/heroine modeling for Puerto Rican adolescents: a preventive mental health intervention.

    Science.gov (United States)

    Malgady, R G; Rogler, L H; Costantino, G

    1990-08-01

    Culturally sensitive treatments of the special mental health needs of high-risk Puerto Rican adolescents are lacking. The hero/heroine intervention was based on adult Puerto Rican role models to foster ethnic identity, self-concept, and adaptive coping behavior. 90 nonclinical Puerto Rican 8th and 9th graders were screened for presenting behavior problems in school and randomly assigned to an intervention and a control group. After 19 sessions, the intervention significantly increased adolescents' ethnic identity and self-concept and reduced anxiety. Treatment outcomes varied as a function of grade level, sex, and household composition. Self-concept was negatively affected among girls from intact families. The study supports the effectiveness of the culturally sensitive modality as a preventive mental health intervention for high-risk Puerto Rican adolescents, especially from single-parent families.

  1. Computational Modeling of Turbulent Spray Combustion

    NARCIS (Netherlands)

    Ma, L.

    2016-01-01

    The objective of the research presented in this thesis is development and validation of predictive models or modeling approaches of liquid fuel combustion (spray combustion) in hot-diluted environments, known as flameless combustion or MILD combustion. The goal is to combine good physical insight, a

  2. Peripheral quantitative computed tomography in children and adolescents: the 2007 ISCD Pediatric Official Positions.

    Science.gov (United States)

    Zemel, Babette; Bass, Shona; Binkley, Teresa; Ducher, Gaele; Macdonald, Heather; McKay, Heather; Moyer-Mileur, Laurie; Shepherd, John; Specker, Bonny; Ward, Kate; Hans, Didier

    2008-01-01

    Peripheral quantitative computed tomography (pQCT) has mainly been used as a research tool in children. To evaluate the clinical utility of pQCT and formulate recommendations for its use in children, the International Society of Clinical Densitometry (ISCD) convened a task force to review the literature and propose areas of consensus and future research. The types of pQCT technology available, the clinical application of pQCT for bone health assessment in children, the important elements to be included in a pQCT report, and quality control monitoring techniques were evaluated. The review revealed a lack of standardization of pQCT techniques, and a paucity of data regarding differences between pQCT manufacturers, models and software versions and their impact in pediatric assessment. Measurement sites varied across studies. Adequate reference data, a critical element for interpretation of pQCT results, were entirely lacking, although some comparative data on healthy children were available. The elements of the pQCT clinical report and quality control procedures are similar to those recommended for dual-energy X-ray absorptiometry. Future research is needed to establish evidence-based criteria for the selection of the measurement site, scan acquisition and analysis parameters, and outcome measures. Reference data that sufficiently characterize the normal range of variability in the population also need to be established.

  3. A computational model of cardiovascular physiology and heart sound generation.

    Science.gov (United States)

    Watrous, Raymond L

    2009-01-01

    A computational model of the cardiovascular system is described which provides a framework for implementing and testing quantitative physiological models of heart sound generation. The lumped-parameter cardiovascular model can be solved for the hemodynamic variables on which the heart sound generation process is built. Parameters of the cardiovascular model can be adjusted to represent various normal and pathological conditions, and the acoustic consequences of those adjustments can be explored. The combined model of the physiology of cardiovascular circulation and heart sound generation has promise for application in teaching, training and algorithm development in computer-aided auscultation of the heart.

  4. Computational model for Halorhodopsin photocurrent kinetics

    Science.gov (United States)

    Bravo, Jaime; Stefanescu, Roxana; Talathi, Sachin

    2013-03-01

    Optogenetics is a rapidly developing novel optical stimulation technique that employs light activated ion channels to excite (using channelrhodopsin (ChR)) or suppress (using halorhodopsin (HR)) impulse activity in neurons with high temporal and spatial resolution. This technique holds enormous potential to externally control activity states in neuronal networks. The channel kinetics of ChR and HR are well understood and amenable for mathematical modeling. Significant progress has been made in recent years to develop models for ChR channel kinetics. To date however, there is no model to mimic photocurrents produced by HR. Here, we report the first model developed for HR photocurrents based on a four-state model of the HR photocurrent kinetics. The model provides an excellent fit (root-mean-square error of 3.1862x10-4, to an empirical profile of experimentally measured HR photocurrents. In combination, mathematical models for ChR and HR photocurrents can provide effective means to design test light based control systems to regulate neural activity, which in turn may have implications for the development of novel light based stimulation paradigms for brain disease control. I would like to thank the University of Florida and the Physics Research Experience for Undergraduates (REU) program, funded through NSF DMR-1156737. This research was also supported through start-up funds provided to Dr. Sachin Talathi

  5. Hybrid Computational Model for High-Altitude Aeroassist Vehicles Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed effort addresses a need for accurate computational models to support aeroassist and entry vehicle system design over a broad range of flight conditions...

  6. ON GLOBAL STABILITY OF A NONRESIDENT COMPUTER VIRUS MODEL

    Institute of Scientific and Technical Information of China (English)

    Yoshiaki MUROYA; Huaixing LI; Toshikazu KUNIYA

    2014-01-01

    In this paper, we establish new sufficient conditions for the infected equilibrium of a nonresident computer virus model to be globally asymptotically stable. Our results extend two kind of known results in recent literature.

  7. Thole's interacting polarizability model in computational chemistry practice

    NARCIS (Netherlands)

    deVries, AH; vanDuijnen, PT; Zijlstra, RWJ; Swart, M

    1997-01-01

    Thole's interacting polarizability model to calculate molecular polarizabilities from interacting atomic polarizabilities is reviewed and its major applications in computational chemistry are illustrated. The applications include prediction of molecular polarizabilities, use in classical expressions

  8. Hybrid Computational Model for High-Altitude Aeroassist Vehicles Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A hybrid continuum/noncontinuum computational model will be developed for analyzing the aerodynamics and heating on aeroassist vehicles. Unique features of this...

  9. Towards diagnostic model calibration and evaluation: Approximate Bayesian computation

    NARCIS (Netherlands)

    Vrugt, J.A.; Sadegh, M.

    2013-01-01

    The ever increasing pace of computational power, along with continued advances in measurement technologies and improvements in process understanding has stimulated the development of increasingly complex hydrologic models that simulate soil moisture flow, groundwater recharge, surface runoff, root w

  10. Computational Modeling, Formal Analysis, and Tools for Systems Biology.

    Science.gov (United States)

    Bartocci, Ezio; Lió, Pietro

    2016-01-01

    As the amount of biological data in the public domain grows, so does the range of modeling and analysis techniques employed in systems biology. In recent years, a number of theoretical computer science developments have enabled modeling methodology to keep pace. The growing interest in systems biology in executable models and their analysis has necessitated the borrowing of terms and methods from computer science, such as formal analysis, model checking, static analysis, and runtime verification. Here, we discuss the most important and exciting computational methods and tools currently available to systems biologists. We believe that a deeper understanding of the concepts and theory highlighted in this review will produce better software practice, improved investigation of complex biological processes, and even new ideas and better feedback into computer science.

  11. Recent Applications of Hidden Markov Models in Computational Biology

    Institute of Scientific and Technical Information of China (English)

    Khar Heng Choo; Joo Chuan Tong; Louxin Zhang

    2004-01-01

    This paper examines recent developments and applications of Hidden Markov Models (HMMs) to various problems in computational biology, including multiple sequence alignment, homology detection, protein sequences classification, and genomic annotation.

  12. An analysis of symbolic linguistic computing models in decision making

    Science.gov (United States)

    Rodríguez, Rosa M.; Martínez, Luis

    2013-01-01

    It is common that experts involved in complex real-world decision problems use natural language for expressing their knowledge in uncertain frameworks. The language is inherent vague, hence probabilistic decision models are not very suitable in such cases. Therefore, other tools such as fuzzy logic and fuzzy linguistic approaches have been successfully used to model and manage such vagueness. The use of linguistic information implies to operate with such a type of information, i.e. processes of computing with words (CWW). Different schemes have been proposed to deal with those processes, and diverse symbolic linguistic computing models have been introduced to accomplish the linguistic computations. In this paper, we overview the relationship between decision making and CWW, and focus on symbolic linguistic computing models that have been widely used in linguistic decision making to analyse if all of them can be considered inside of the CWW paradigm.

  13. COMPUTATION MODELING OF TCDD DISRUPTION OF B CELL TERMINAL DIFFERENTIATION

    Science.gov (United States)

    In this study, we established a computational model describing the molecular circuit underlying B cell terminal differentiation and how TCDD may affect this process by impinging upon various molecular targets.

  14. The Next Generation ARC Middleware and ATLAS Computing Model

    CERN Document Server

    Filipcic, A; The ATLAS collaboration; Smirnova, O; Konstantinov, A; Karpenko, D

    2012-01-01

    The distributed NDGF Tier-1 and associated Nordugrid clusters are well integrated into the ATLAS computing model but follow a slightly different paradigm than other ATLAS resources. The current strategy does not divide the sites as in the commonly used hierarchical model, but rather treats them as a single storage endpoint and a pool of distributed computing nodes. The next generation ARC middleware with its several new technologies provides new possibilities in development of the ATLAS computing model, such as pilot jobs with pre-cached input files, automatic job migration between the sites, integration of remote sites without connected storage elements, and automatic brokering for jobs with non-standard resource requirements. ARC's data transfer model provides an automatic way for the computing sites to participate in ATLAS' global task management system without requiring centralised brokering or data transfer services. The powerful API combined with Python and Java bindings can easily be used to build new ...

  15. COMPUTING

    CERN Multimedia

    M. Kasemann

    Overview In autumn the main focus was to process and handle CRAFT data and to perform the Summer08 MC production. The operational aspects were well covered by regular Computing Shifts, experts on duty and Computing Run Coordination. At the Computing Resource Board (CRB) in October a model to account for service work at Tier 2s was approved. The computing resources for 2009 were reviewed for presentation at the C-RRB. The quarterly resource monitoring is continuing. Facilities/Infrastructure operations Operations during CRAFT data taking ran fine. This proved to be a very valuable experience for T0 workflows and operations. The transfers of custodial data to most T1s went smoothly. A first round of reprocessing started at the Tier-1 centers end of November; it will take about two weeks. The Computing Shifts procedure was tested full scale during this period and proved to be very efficient: 30 Computing Shifts Persons (CSP) and 10 Computing Resources Coordinators (CRC). The shift program for the shut down w...

  16. Formal modelling techniques in human-computer interaction

    NARCIS (Netherlands)

    Haan, de G.; Veer, van der G.C.; Vliet, van J.C.

    1991-01-01

    This paper is a theoretical contribution, elaborating the concept of models as used in Cognitive Ergonomics. A number of formal modelling techniques in human-computer interaction will be reviewed and discussed. The analysis focusses on different related concepts of formal modelling techniques in hum

  17. Language acquisition and implication for language change: A computational model.

    OpenAIRE

    Clark, Robert A.J.

    1997-01-01

    Computer modeling techniques, when applied to language acquisition problems, give an often unrealized insight into the diachronic change that occurs in language over successive generations. This paper shows that using assumptions about language acquisition to model successive generations of learners in a computer simulation, can have a drastic effect on the long term changes that occur in a language. More importantly, it shows that slight changes in the acquisition ...

  18. Mathematical and computational modeling in biology at multiple scales

    OpenAIRE

    Tuszynski, Jack A; Winter, Philip; White, Diana; Tseng, Chih-Yuan; Sahu, Kamlesh K.; Gentile, Francesco; Spasevska, Ivana; Omar, Sara Ibrahim; Nayebi, Niloofar; Churchill, Cassandra DM; Klobukowski, Mariusz; El-Magd, Rabab M Abou

    2014-01-01

    A variety of topics are reviewed in the area of mathematical and computational modeling in biology, covering the range of scales from populations of organisms to electrons in atoms. The use of maximum entropy as an inference tool in the fields of biology and drug discovery is discussed. Mathematical and computational methods and models in the areas of epidemiology, cell physiology and cancer are surveyed. The technique of molecular dynamics is covered, with special attention to force fields f...

  19. Cascade recursion models of computing the temperatures of underground layers

    Institute of Scientific and Technical Information of China (English)

    HAN; Liqun; BI; Siwen; SONG; Shixin

    2006-01-01

    An RBF neural network was used to construct computational models of the underground temperatures of different layers, using ground-surface parameters and the temperatures of various underground layers. Because series recursion models also enable researchers to use above-ground surface parameters to compute the temperatures of different underground layers, this method provides a new way of using thermal infrared remote sensing to monitor the suture zones of large areas of blocks and to research thermal anomalies in geologic structures.

  20. A Situative Space Model for Mobile Mixed-Reality Computing

    DEFF Research Database (Denmark)

    Pederson, Thomas; Janlert, Lars-Erik; Surie, Dipak

    2011-01-01

    This article proposes a situative space model that links the physical and virtual realms and sets the stage for complex human-computer interaction defined by what a human agent can see, hear, and touch, at any given point in time.......This article proposes a situative space model that links the physical and virtual realms and sets the stage for complex human-computer interaction defined by what a human agent can see, hear, and touch, at any given point in time....

  1. Theoretic computing model of combustion process of asphalt smoke

    Institute of Scientific and Technical Information of China (English)

    HUANG Rui; CHAI Li-yuan; HE De-wen; PENG Bing; WANG Yun-yan

    2005-01-01

    Based on the data and methods provided by research literature, dispersing mathematical model of combustion process of asphalt smoke is set by theoretic analysis. Through computer programming, the dynamic combustion process of asphalt smoke is calculated to simulate an experimental model. The computing result shows that the temperature and the concentration of asphalt smoke influence its burning temperature in approximatively linear manner. The consumed quantity of fuel to ignite the asphalt smoke needs to be measured from the two factors.

  2. Models for the discrete berth allocation problem: A computational comparison

    DEFF Research Database (Denmark)

    Buhrkal, Katja Frederik; Zuglian, Sara; Røpke, Stefan;

    2011-01-01

    In this paper we consider the problem of allocating arriving ships to discrete berth locations at container terminals. This problem is recognized as one of the most important processes for any container terminal. We review and describe three main models of the discrete dynamic berth allocation pr...... problem, improve the performance of one model, and, through extensive numerical tests, compare all models from a computational perspective. The results indicate that a generalized set-partitioning model outperforms all other existing models....

  3. Improved Computational Model of Grid Cells Based on Column Structure

    Institute of Scientific and Technical Information of China (English)

    Yang Zhou; Dewei Wu; Weilong Li; Jia Du

    2016-01-01

    To simulate the firing pattern of biological grid cells, this paper presents an improved computational model of grid cells based on column structure. In this model, the displacement along different directions is processed by modulus operation, and the obtained remainder is associated with firing rate of grid cell. Compared with the original model, the improved parts include that: the base of modulus operation is changed, and the firing rate in firing field is encoded by Gaussian⁃like function. Simulation validates that the firing pattern generated by the improved computational model is more consistent with biological characteristic than original model. Besides, the firing pattern is badly influenced by the cumulative positioning error, but the computational model can also generate the regularly hexagonal firing pattern when the real⁃time positioning results are modified.

  4. Computer Models and Automata Theory in Biology and Medicine

    CERN Document Server

    Baianu, I C

    2004-01-01

    The applications of computers to biological and biomedical problem solving goes back to the very beginnings of computer science, automata theory [1], and mathematical biology [2]. With the advent of more versatile and powerful computers, biological and biomedical applications of computers have proliferated so rapidly that it would be virtually impossible to compile a comprehensive review of all developments in this field. Limitations of computer simulations in biology have also come under close scrutiny, and claims have been made that biological systems have limited information processing power [3]. Such general conjectures do not, however, deter biologists and biomedical researchers from developing new computer applications in biology and medicine. Microprocessors are being widely employed in biological laboratories both for automatic data acquisition/processing and modeling; one particular area, which is of great biomedical interest, involves fast digital image processing and is already established for rout...

  5. Complex system modelling and control through intelligent soft computations

    CERN Document Server

    Azar, Ahmad

    2015-01-01

    The book offers a snapshot of the theories and applications of soft computing in the area of complex systems modeling and control. It presents the most important findings discussed during the 5th International Conference on Modelling, Identification and Control, held in Cairo, from August 31-September 2, 2013. The book consists of twenty-nine selected contributions, which have been thoroughly reviewed and extended before their inclusion in the volume. The different chapters, written by active researchers in the field, report on both current theories and important applications of soft-computing. Besides providing the readers with soft-computing fundamentals, and soft-computing based inductive methodologies/algorithms, the book also discusses key industrial soft-computing applications, as well as multidisciplinary solutions developed for a variety of purposes, like windup control, waste management, security issues, biomedical applications and many others. It is a perfect reference guide for graduate students, r...

  6. Punishing adolescents

    DEFF Research Database (Denmark)

    Ryberg, Jesper

    2014-01-01

    Should an adolescent offender be punished more leniently than an adult offender? Many theorists believe the answer to be in the affirmative. According to the diminished culpability model, adolescents are less mature than adults and, therefore, less responsible for their wrongdoings and should...

  7. Computational model of miniature pulsating heat pipes.

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Mario J.; Givler, Richard C.

    2013-01-01

    The modeling work described herein represents Sandia National Laboratories (SNL) portion of a collaborative three-year project with Northrop Grumman Electronic Systems (NGES) and the University of Missouri to develop an advanced, thermal ground-plane (TGP), which is a device, of planar configuration, that delivers heat from a source to an ambient environment with high efficiency. Work at all three institutions was funded by DARPA/MTO; Sandia was funded under DARPA/MTO project number 015070924. This is the final report on this project for SNL. This report presents a numerical model of a pulsating heat pipe, a device employing a two phase (liquid and its vapor) working fluid confined in a closed loop channel etched/milled into a serpentine configuration in a solid metal plate. The device delivers heat from an evaporator (hot zone) to a condenser (cold zone). This new model includes key physical processes important to the operation of flat plate pulsating heat pipes (e.g. dynamic bubble nucleation, evaporation and condensation), together with conjugate heat transfer with the solid portion of the device. The model qualitatively and quantitatively predicts performance characteristics and metrics, which was demonstrated by favorable comparisons with experimental results on similar configurations. Application of the model also corroborated many previous performance observations with respect to key parameters such as heat load, fill ratio and orientation.

  8. Computational model of miniature pulsating heat pipes

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Mario J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Givler, Richard C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2013-01-01

    The modeling work described herein represents Sandia National Laboratories (SNL) portion of a collaborative three-year project with Northrop Grumman Electronic Systems (NGES) and the University of Missouri to develop an advanced, thermal ground-plane (TGP), which is a device, of planar configuration, that delivers heat from a source to an ambient environment with high efficiency. Work at all three institutions was funded by DARPA/MTO; Sandia was funded under DARPA/MTO project number 015070924. This is the final report on this project for SNL. This report presents a numerical model of a pulsating heat pipe, a device employing a two phase (liquid and its vapor) working fluid confined in a closed loop channel etched/milled into a serpentine configuration in a solid metal plate. The device delivers heat from an evaporator (hot zone) to a condenser (cold zone). This new model includes key physical processes important to the operation of flat plate pulsating heat pipes (e.g. dynamic bubble nucleation, evaporation and condensation), together with conjugate heat transfer with the solid portion of the device. The model qualitatively and quantitatively predicts performance characteristics and metrics, which was demonstrated by favorable comparisons with experimental results on similar configurations. Application of the model also corroborated many previous performance observations with respect to key parameters such as heat load, fill ratio and orientation.

  9. Systematic Methods and Tools for Computer Aided Modelling

    DEFF Research Database (Denmark)

    Fedorova, Marina

    -friendly system, which will make the model development process easier and faster and provide the way for unified and consistent model documentation. The modeller can use the template for their specific problem or to extend and/or adopt a model. This is based on the idea of model reuse, which emphasizes the use...... and processes can be faster, cheaper and very efficient. The developed modelling framework involves five main elements: 1) a modelling tool, that includes algorithms for model generation; 2) a template library, which provides building blocks for the templates (generic models previously developed); 3) computer...... aided methods and tools, that include procedures to perform model translation, model analysis, model verification/validation, model solution and model documentation; 4) model transfer – export/import to/from other application for further extension and application – several types of formats, such as XML...

  10. Global Stability of an Epidemic Model of Computer Virus

    Directory of Open Access Journals (Sweden)

    Xiaofan Yang

    2014-01-01

    Full Text Available With the rapid popularization of the Internet, computers can enter or leave the Internet increasingly frequently. In fact, no antivirus software can detect and remove all sorts of computer viruses. This implies that viruses would persist on the Internet. To better understand the spread of computer viruses in these situations, a new propagation model is established and analyzed. The unique equilibrium of the model is globally asymptotically stable, in accordance with the reality. A parameter analysis of the equilibrium is also conducted.

  11. Computational quantum chemistry and adaptive ligand modeling in mechanistic QSAR.

    Science.gov (United States)

    De Benedetti, Pier G; Fanelli, Francesca

    2010-10-01

    Drugs are adaptive molecules. They realize this peculiarity by generating different ensembles of prototropic forms and conformers that depend on the environment. Among the impressive amount of available computational drug discovery technologies, quantitative structure-activity relationship approaches that rely on computational quantum chemistry descriptors are the most appropriate to model adaptive drugs. Indeed, computational quantum chemistry descriptors are able to account for the variation of the intramolecular interactions of the training compounds, which reflect their adaptive intermolecular interaction propensities. This enables the development of causative, interpretive and reasonably predictive quantitative structure-activity relationship models, and, hence, sound chemical information finalized to drug design and discovery.

  12. Computational Models for Analysis of Illicit Activities

    DEFF Research Database (Denmark)

    Nizamani, Sarwat

    result in a fully evolved network. This method of network evolution can help intelligence security analysts to understand the structure of the network. For suspicious emails detection and email author identification, a cluster-based text classification model has been proposed. The model outperformed...... traditional models for both of the tasks. Apart from these globally organized crimes and cybercrimes, there happen specific world issues which affect geographic locations and take the form of bursts of public violence. These kinds of issues have received little attention by the academicians. These issues have...... to describe the phenomenon of contagious public outrage, which eventually leads to the spread of violence following a disclosure of some unpopular political decisions and/or activity. The results shed a new light on terror activity and provide some hint on how to curb the spreading of violence within...

  13. Computational social network modeling of terrorist recruitment.

    Energy Technology Data Exchange (ETDEWEB)

    Berry, Nina M.; Turnley, Jessica Glicken (Sandia National Laboratories, Albuquerque, NM); Smrcka, Julianne D. (Sandia National Laboratories, Albuquerque, NM); Ko, Teresa H.; Moy, Timothy David (Sandia National Laboratories, Albuquerque, NM); Wu, Benjamin C.

    2004-10-01

    The Seldon terrorist model represents a multi-disciplinary approach to developing organization software for the study of terrorist recruitment and group formation. The need to incorporate aspects of social science added a significant contribution to the vision of the resulting Seldon toolkit. The unique addition of and abstract agent category provided a means for capturing social concepts like cliques, mosque, etc. in a manner that represents their social conceptualization and not simply as a physical or economical institution. This paper provides an overview of the Seldon terrorist model developed to study the formation of cliques, which are used as the major recruitment entity for terrorist organizations.

  14. Computer Models Simulate Fine Particle Dispersion

    Science.gov (United States)

    2010-01-01

    Through a NASA Seed Fund partnership with DEM Solutions Inc., of Lebanon, New Hampshire, scientists at Kennedy Space Center refined existing software to study the electrostatic phenomena of granular and bulk materials as they apply to planetary surfaces. The software, EDEM, allows users to import particles and obtain accurate representations of their shapes for modeling purposes, such as simulating bulk solids behavior, and was enhanced to be able to more accurately model fine, abrasive, cohesive particles. These new EDEM capabilities can be applied in many industries unrelated to space exploration and have been adopted by several prominent U.S. companies, including John Deere, Pfizer, and Procter & Gamble.

  15. Scratch as a computational modelling tool for teaching physics

    Science.gov (United States)

    Lopez, Victor; Hernandez, Maria Isabel

    2015-05-01

    The Scratch online authoring tool, which features a simple programming language that has been adapted to primary and secondary students, is being used more and more in schools as it offers students and teachers the opportunity to use a tool to build scientific models and evaluate their behaviour, just as can be done with computational modelling programs. In this article, we briefly discuss why Scratch could be a useful tool for computational modelling in the primary or secondary physics classroom, and we present practical examples of how it can be used to build a model.

  16. Assessment of weld thickness loss in offshore pipelines using computed radiography and computational modeling

    Energy Technology Data Exchange (ETDEWEB)

    Correa, S.C.A. [Programa de Engenharia Nuclear/COPPE, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21945-970, Rio de Janeiro, RJ (Brazil); Centro Universitario Estadual da Zona Oeste - UEZO, Avenida Manuel Caldeira de Alvarenga, 1203, 23070-200, Rio de Janeiro, RJ (Brazil)], E-mail: scorrea@con.ufrj.br; Souza, E.M. [Programa de Engenharia Nuclear/COPPE, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21945-970, Rio de Janeiro, RJ (Brazil); Departamento de Geologia/IGEO, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21945-970, Rio de Janeiro, RJ (Brazil); Oliveira, D.F. [Programa de Engenharia Nuclear/COPPE, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21945-970, Rio de Janeiro, RJ (Brazil); Silva, A.X. [PEN/COPPE-DNC/Poli-CT, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21945-970, Rio de Janeiro, RJ (Brazil); Lopes, R.T. [Programa de Engenharia Nuclear, COPPE, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21945-970, Rio de Janeiro, RJ (Brazil); Marinho, C.; Camerini, C.S. [CENPES/PDEP/TMEC/PETROBRAS, Ilha do Fundao, Cidade Universitaria, 21949-900, Rio de Janeiro, RJ (Brazil)

    2009-10-15

    In order to guarantee the structural integrity of oil plants it is crucial to monitor the amount of weld thickness loss in offshore pipelines. However, in spite of its relevance, this parameter is very difficult to determine, due to both the large diameter of most pipes and the complexity of the multi-variable system involved. In this study, a computational modeling based on Monte Carlo MCNPX code is combined with computed radiography to estimate the weld thickness loss in large-diameter offshore pipelines. Results show that computational modeling is a powerful tool to estimate intensity variations in radiographic images generated by weld thickness variations, and it can be combined with computed radiography to assess weld thickness loss in offshore and subsea pipelines.

  17. Emotion in Music: representation and computational modeling

    NARCIS (Netherlands)

    Aljanaki, A.

    2016-01-01

    Music emotion recognition (MER) deals with music classification by emotion using signal processing and machine learning techniques. Emotion ontology for music is not well established yet. Musical emotion can be conceptualized through various emotional models: categorical, dimensional, or domain-spec

  18. Electricity load modelling using computational intelligence

    NARCIS (Netherlands)

    Ter Borg, R.W.

    2005-01-01

    As a consequence of the liberalisation of the electricity markets in Europe, market players have to continuously adapt their future supply to match their customers' demands. This poses the challenge of obtaining a predictive model that accurately describes electricity loads, current in this thesis.

  19. A Computational Model of Spatial Development

    Science.gov (United States)

    Hiraki, Kazuo; Sashima, Akio; Phillips, Steven

    Psychological experiments on children's development of spatial knowledge suggest experience at self-locomotion with visual tracking as important factors. Yet, the mechanism underlying development is unknown. We propose a robot that learns to mentally track a target object (i.e., maintaining a representation of an object's position when outside the field-of-view) as a model for spatial development. Mental tracking is considered as prediction of an object's position given the previous environmental state and motor commands, and the current environment state resulting from movement. Following Jordan & Rumelhart's (1992) forward modeling architecture the system consists of two components: an inverse model of sensory input to desired motor commands; and a forward model of motor commands to desired sensory input (goals). The robot was tested on the `three cups' paradigm (where children are required to select the cup containing the hidden object under various movement conditions). Consistent with child development, without the capacity for self-locomotion the robot's errors are self-center based. When given the ability of self-locomotion the robot responds allocentrically.

  20. Computational Failure Modeling of Lower Extremities

    Science.gov (United States)

    2012-01-01

    0.3 σc = 132 MPa c = 0.1 ρ = 1810 kg/m3 [15] Trabecular bone Elastic with maximum principle stress-based fracture model E = 300 MPa v = 0.45 σc...39762 1 SANDIA NATL LAB NANOSCALE AND REACTIVE PROCESSES S SCHUMACHER PO BOX 5800 MS 0836 ALBUQUERQUE NEW MEXICO 87185-0836

  1. Computational Modeling of Fluorescence Loss in Photobleaching

    DEFF Research Database (Denmark)

    Hansen, Christian Valdemar; Schroll, Achim; Wüstner, Daniel

    2015-01-01

    Fluorescence loss in photobleaching (FLIP) is a modern microscopy method for visualization of transport processes in living cells. Although FLIP is widespread, an automated reliable analysis of image data is still lacking. This paper presents a framework for modeling and simulation of FLIP...

  2. Validation Study of Tripartite Model of Anxiety and Depression in Children and Adolescents: Clinical Sample in Korea

    OpenAIRE

    Yang, Jae-Won; Hong, Sungdo D.; Joung, Yoo Sook; Kim, Ji-Hae

    2006-01-01

    Although the currently available literature has provided some empirical support for a tripartite model of child and adolescent anxiety and depression, one of the limitations of these studies was that they have been conducted in America, primarily with Caucasians. In order to make this model more applicable to diverse ethnic and cultural groups, this study used a tripartite model for child and adolescent anxiety and depression in Korea, using confirmatory factor analysis with logically selecte...

  3. Enabling Grid Computing resources within the KM3NeT computing model

    Directory of Open Access Journals (Sweden)

    Filippidis Christos

    2016-01-01

    Full Text Available KM3NeT is a future European deep-sea research infrastructure hosting a new generation neutrino detectors that – located at the bottom of the Mediterranean Sea – will open a new window on the universe and answer fundamental questions both in particle physics and astrophysics. International collaborative scientific experiments, like KM3NeT, are generating datasets which are increasing exponentially in both complexity and volume, making their analysis, archival, and sharing one of the grand challenges of the 21st century. These experiments, in their majority, adopt computing models consisting of different Tiers with several computing centres and providing a specific set of services for the different steps of data processing such as detector calibration, simulation and data filtering, reconstruction and analysis. The computing requirements are extremely demanding and, usually, span from serial to multi-parallel or GPU-optimized jobs. The collaborative nature of these experiments demands very frequent WAN data transfers and data sharing among individuals and groups. In order to support the aforementioned demanding computing requirements we enabled Grid Computing resources, operated by EGI, within the KM3NeT computing model. In this study we describe our first advances in this field and the method for the KM3NeT users to utilize the EGI computing resources in a simulation-driven use-case.

  4. Enabling Grid Computing resources within the KM3NeT computing model

    Science.gov (United States)

    Filippidis, Christos

    2016-04-01

    KM3NeT is a future European deep-sea research infrastructure hosting a new generation neutrino detectors that - located at the bottom of the Mediterranean Sea - will open a new window on the universe and answer fundamental questions both in particle physics and astrophysics. International collaborative scientific experiments, like KM3NeT, are generating datasets which are increasing exponentially in both complexity and volume, making their analysis, archival, and sharing one of the grand challenges of the 21st century. These experiments, in their majority, adopt computing models consisting of different Tiers with several computing centres and providing a specific set of services for the different steps of data processing such as detector calibration, simulation and data filtering, reconstruction and analysis. The computing requirements are extremely demanding and, usually, span from serial to multi-parallel or GPU-optimized jobs. The collaborative nature of these experiments demands very frequent WAN data transfers and data sharing among individuals and groups. In order to support the aforementioned demanding computing requirements we enabled Grid Computing resources, operated by EGI, within the KM3NeT computing model. In this study we describe our first advances in this field and the method for the KM3NeT users to utilize the EGI computing resources in a simulation-driven use-case.

  5. Computational challenges in modeling and simulating living matter

    Science.gov (United States)

    Sena, Alexandre C.; Silva, Dilson; Marzulo, Leandro A. J.; de Castro, Maria Clicia Stelling

    2016-12-01

    Computational modeling has been successfully used to help scientists understand physical and biological phenomena. Recent technological advances allowthe simulation of larger systems, with greater accuracy. However, devising those systems requires new approaches and novel architectures, such as the use of parallel programming, so that the application can run in the new high performance environments, which are often computer clusters composed of different computation devices, as traditional CPUs, GPGPUs, Xeon Phis and even FPGAs. It is expected that scientists take advantage of the increasing computational power to model and simulate more complex structures and even merge different models into larger and more extensive ones. This paper aims at discussing the challenges of using those devices to simulate such complex systems.

  6. Computational mathematics models, methods, and analysis with Matlab and MPI

    CERN Document Server

    White, Robert E

    2004-01-01

    Computational Mathematics: Models, Methods, and Analysis with MATLAB and MPI explores and illustrates this process. Each section of the first six chapters is motivated by a specific application. The author applies a model, selects a numerical method, implements computer simulations, and assesses the ensuing results. These chapters include an abundance of MATLAB code. By studying the code instead of using it as a "black box, " you take the first step toward more sophisticated numerical modeling. The last four chapters focus on multiprocessing algorithms implemented using message passing interface (MPI). These chapters include Fortran 9x codes that illustrate the basic MPI subroutines and revisit the applications of the previous chapters from a parallel implementation perspective. All of the codes are available for download from www4.ncsu.edu./~white.This book is not just about math, not just about computing, and not just about applications, but about all three--in other words, computational science. Whether us...

  7. A Lumped Computational Model for Sodium Sulfur Battery Analysis

    Science.gov (United States)

    Wu, Fan

    Due to the cost of materials and time consuming testing procedures, development of new batteries is a slow and expensive practice. The purpose of this study is to develop a computational model and assess the capabilities of such a model designed to aid in the design process and control of sodium sulfur batteries. To this end, a transient lumped computational model derived from an integral analysis of the transport of species, energy and charge throughout the battery has been developed. The computation processes are coupled with the use of Faraday's law, and solutions for the species concentrations, electrical potential and current are produced in a time marching fashion. Properties required for solving the governing equations are calculated and updated as a function of time based on the composition of each control volume. The proposed model is validated against multi- dimensional simulations and experimental results from literatures, and simulation results using the proposed model is presented and analyzed. The computational model and electrochemical model used to solve the equations for the lumped model are compared with similar ones found in the literature. The results obtained from the current model compare favorably with those from experiments and other models.

  8. Images as drivers of progress in cardiac computational modelling.

    Science.gov (United States)

    Lamata, Pablo; Casero, Ramón; Carapella, Valentina; Niederer, Steve A; Bishop, Martin J; Schneider, Jürgen E; Kohl, Peter; Grau, Vicente

    2014-08-01

    Computational models have become a fundamental tool in cardiac research. Models are evolving to cover multiple scales and physical mechanisms. They are moving towards mechanistic descriptions of personalised structure and function, including effects of natural variability. These developments are underpinned to a large extent by advances in imaging technologies. This article reviews how novel imaging technologies, or the innovative use and extension of established ones, integrate with computational models and drive novel insights into cardiac biophysics. In terms of structural characterization, we discuss how imaging is allowing a wide range of scales to be considered, from cellular levels to whole organs. We analyse how the evolution from structural to functional imaging is opening new avenues for computational models, and in this respect we review methods for measurement of electrical activity, mechanics and flow. Finally, we consider ways in which combined imaging and modelling research is likely to continue advancing cardiac research, and identify some of the main challenges that remain to be solved.

  9. The spinal posture of computing adolescents in a real-life setting

    OpenAIRE

    Brink, Yolandi; Louw,Quinette; Grimmer, Karen; Jordaan, Esmè

    2014-01-01

    Background It is assumed that good postural alignment is associated with the less likelihood of musculoskeletal pain symptoms. Encouraging good sitting postures have not reported consequent musculoskeletal pain reduction in school-based populations, possibly due to a lack of clear understanding of good posture. Therefore this paper describes the variability of postural angles in a cohort of asymptomatic high-school students whilst working on desk-top computers in a school computer classroom a...

  10. A distributed computing model for telemetry data processing

    Science.gov (United States)

    Barry, Matthew R.; Scott, Kevin L.; Weismuller, Steven P.

    1994-05-01

    We present a new approach to distributing processed telemetry data among spacecraft flight controllers within the control centers at NASA's Johnson Space Center. This approach facilitates the development of application programs which integrate spacecraft-telemetered data and ground-based synthesized data, then distributes this information to flight controllers for analysis and decision-making. The new approach combines various distributed computing models into one hybrid distributed computing model. The model employs both client-server and peer-to-peer distributed computing models cooperating to provide users with information throughout a diverse operations environment. Specifically, it provides an attractive foundation upon which we are building critical real-time monitoring and control applications, while simultaneously lending itself to peripheral applications in playback operations, mission preparations, flight controller training, and program development and verification. We have realized the hybrid distributed computing model through an information sharing protocol. We shall describe the motivations that inspired us to create this protocol, along with a brief conceptual description of the distributed computing models it employs. We describe the protocol design in more detail, discussing many of the program design considerations and techniques we have adopted. Finally, we describe how this model is especially suitable for supporting the implementation of distributed expert system applications.

  11. A distributed computing model for telemetry data processing

    Science.gov (United States)

    Barry, Matthew R.; Scott, Kevin L.; Weismuller, Steven P.

    1994-01-01

    We present a new approach to distributing processed telemetry data among spacecraft flight controllers within the control centers at NASA's Johnson Space Center. This approach facilitates the development of application programs which integrate spacecraft-telemetered data and ground-based synthesized data, then distributes this information to flight controllers for analysis and decision-making. The new approach combines various distributed computing models into one hybrid distributed computing model. The model employs both client-server and peer-to-peer distributed computing models cooperating to provide users with information throughout a diverse operations environment. Specifically, it provides an attractive foundation upon which we are building critical real-time monitoring and control applications, while simultaneously lending itself to peripheral applications in playback operations, mission preparations, flight controller training, and program development and verification. We have realized the hybrid distributed computing model through an information sharing protocol. We shall describe the motivations that inspired us to create this protocol, along with a brief conceptual description of the distributed computing models it employs. We describe the protocol design in more detail, discussing many of the program design considerations and techniques we have adopted. Finally, we describe how this model is especially suitable for supporting the implementation of distributed expert system applications.

  12. Instability phenomena in plasticity: Modelling and computation

    Science.gov (United States)

    Stein, E.; Steinmann, P.; Miehe, C.

    1995-12-01

    We presented aspects and results related to the broad field of strain localization with special focus on large strain elastoplastic response. Therefore, we first re-examined issues related to the classification of discontinuities and the classical description of localization with a particular emphasis on an Eulerian geometric representation. We touched the problem of mesh objectivity and discussed results of a particular regularization method, namely the micropolar approach. Generally, regularization has to preserve ellipticity and to reflect the underlying physics. For example ductile materials have to be modelled including viscous effects whereas geomaterials are adequately described by the micropolar approach. Then we considered localization phenomena within solids undergoing large strain elastoplastic deformations. Here, we documented the influence of isotropic damage on the failure analysis. Next, the interesting influence of an orthotropic yield condition on the spatial orientation of localized zones has been studied. Finally, we investigated the localization condition for an algorithmic model of finite strain single crystal plasticity.

  13. An animal model of social instability stress in adolescence and risk for drugs of abuse.

    Science.gov (United States)

    McCormick, Cheryl M

    2010-02-09

    There is increasing evidence that adolescence, like early life, is a sensitive period in which ongoing brain development can be influenced by environmental factors. This review describes our use of social instability as a model of mild adolescent social stress, its effects on social interactions and on hypothalamic-pituitary-adrenal function over the course of the procedure and in response to new stressors. The effects of social instability are sex-specific, with qualitative differences between the sexes on HPA function over the course of the stressor procedure, and with greater effects in males on behaviour observed during the social instability and greater effects in females on behavioural responses to drugs of abuse into adulthood, long after the stress exposure. The results from investigations with this model of adolescent social stress are discussed in relation to those of studies using other stressor procedures. Elevated exposure to glucocorticoids over the course of adolescence confers sex-specific changes in behavioural responses to drugs of abuse, which may be of relevance for understanding risk factors in people.

  14. Integrated Multiscale Modeling of Molecular Computing Devices

    Energy Technology Data Exchange (ETDEWEB)

    Gregory Beylkin

    2012-03-23

    Significant advances were made on all objectives of the research program. We have developed fast multiresolution methods for performing electronic structure calculations with emphasis on constructing efficient representations of functions and operators. We extended our approach to problems of scattering in solids, i.e. constructing fast algorithms for computing above the Fermi energy level. Part of the work was done in collaboration with Robert Harrison and George Fann at ORNL. Specific results (in part supported by this grant) are listed here and are described in greater detail. (1) We have implemented a fast algorithm to apply the Green's function for the free space (oscillatory) Helmholtz kernel. The algorithm maintains its speed and accuracy when the kernel is applied to functions with singularities. (2) We have developed a fast algorithm for applying periodic and quasi-periodic, oscillatory Green's functions and those with boundary conditions on simple domains. Importantly, the algorithm maintains its speed and accuracy when applied to functions with singularities. (3) We have developed a fast algorithm for obtaining and applying multiresolution representations of periodic and quasi-periodic Green's functions and Green's functions with boundary conditions on simple domains. (4) We have implemented modifications to improve the speed of adaptive multiresolution algorithms for applying operators which are represented via a Gaussian expansion. (5) We have constructed new nearly optimal quadratures for the sphere that are invariant under the icosahedral rotation group. (6) We obtained new results on approximation of functions by exponential sums and/or rational functions, one of the key methods that allows us to construct separated representations for Green's functions. (7) We developed a new fast and accurate reduction algorithm for obtaining optimal approximation of functions by exponential sums and/or their rational representations.

  15. Computational modeling of nuclear thermal rockets

    Science.gov (United States)

    Peery, Steven D.

    1993-01-01

    The topics are presented in viewgraph form and include the following: rocket engine transient simulation (ROCETS) system; ROCETS performance simulations composed of integrated component models; ROCETS system architecture significant features; ROCETS engineering nuclear thermal rocket (NTR) modules; ROCETS system easily adapts Fortran engineering modules; ROCETS NTR reactor module; ROCETS NTR turbomachinery module; detailed reactor analysis; predicted reactor power profiles; turbine bypass impact on system; and ROCETS NTR engine simulation summary.

  16. Computational Modeling of Lipid Metabolism in Yeast

    Directory of Open Access Journals (Sweden)

    Vera Schützhold

    2016-09-01

    Full Text Available Lipid metabolism is essential for all major cell functions and has recently gained increasing attention in research and health studies. However, mathematical modeling by means of classical approaches such as stoichiometric networks and ordinary differential equation systems has not yet provided satisfactory insights, due to the complexity of lipid metabolism characterized by many different species with only slight differences and by promiscuous multifunctional enzymes.Here, we present a object-oriented stochastic model approach as a way to cope with the complex lipid metabolic network. While all lipid species are treated objects in the model, they can be modified by the respective converting reactions based on reaction rules, a hybrid method that integrates benefits of agent-based and classical stochastic simulation. This approach allows to follow the dynamics of all lipid species with different fatty acids, different degrees of saturation and different headgroups over time and to analyze the effect of parameter changes, potential mutations in the catalyzing enzymes or provision of different precursors. Applied to yeast metabolism during one cell cycle period, we could analyze the distribution of all lipids to the various membranes in time-dependent manner.The presented approach allows to efficiently treat the complexity of cellular lipid metabolism and to derive conclusions on the time- and location-dependent distributions of lipid species and their properties such as saturation. It is widely applicable, easily extendable and will provide further insights in healthy and diseased states of cell metabolism.

  17. A risk computation model for environmental restoration activities

    Energy Technology Data Exchange (ETDEWEB)

    Droppo, J.B. Jr.; Strenge, D.L.; Buck, J.W.

    1991-01-01

    A risk computation model useful in environmental restoration activities was developed for the US Department of Energy (DOE). This model, the Multimedia Environmental Pollutant Assessment System (MEPAS), can be used to evaluate effects of potential exposures over a broad range of regulatory issues including radioactive carcinogenic, nonradioactive carcinogenic, and noncarcinogenic effects. MEPAS integrates risk computation components. Release, transport, dispersion, deposition, exposure, and uptake computations are linked in a single system for evaluation of air, surface water, ground water, and overland flow transport. MEPAS uses standard computation approaches. Whenever available and appropriate, US Environmental Protection Agency guidance and models were used to facilitate compatibility and acceptance. MEPAS is a computational tool that can be used at several phases of an environmental restoration effort. At a preliminary stage in problem characterization, potential problems can be prioritized. As more data become available, MEPAS can provide an estimate of baseline risks or evaluate environmental monitoring data. In the feasibility stage, MEPAS can compute risk from alternative remedies. However, MEPAS is not designed to replace a detailed risk assessment of the selected remedy. For major problems, it will be appropriate to use a more detailed, risk computation tool for a detailed, site-specific evaluation of the selected remedy. 15 refs., 2 figs.

  18. Simulation model of load balancing in distributed computing systems

    Science.gov (United States)

    Botygin, I. A.; Popov, V. N.; Frolov, S. G.

    2017-02-01

    The availability of high-performance computing, high speed data transfer over the network and widespread of software for the design and pre-production in mechanical engineering have led to the fact that at the present time the large industrial enterprises and small engineering companies implement complex computer systems for efficient solutions of production and management tasks. Such computer systems are generally built on the basis of distributed heterogeneous computer systems. The analytical problems solved by such systems are the key models of research, but the system-wide problems of efficient distribution (balancing) of the computational load and accommodation input, intermediate and output databases are no less important. The main tasks of this balancing system are load and condition monitoring of compute nodes, and the selection of a node for transition of the user’s request in accordance with a predetermined algorithm. The load balancing is one of the most used methods of increasing productivity of distributed computing systems through the optimal allocation of tasks between the computer system nodes. Therefore, the development of methods and algorithms for computing optimal scheduling in a distributed system, dynamically changing its infrastructure, is an important task.

  19. PEMAHAMAN DASAR ANALISIS MODEL COMPUTABLE GENERAL EQUILIBRIUM (CGE

    Directory of Open Access Journals (Sweden)

    Mardiyah Hayati

    2013-11-01

    Full Text Available Simple paper about basic understanding of computable general equilibrium aimed to give basic understanding about CGE. It consist of history of CGE, assumption of CGE model, excess and lack of CGE model, and creation of simple CGE model for closed economy. CGE model is suitable to be used for seeing impact of new policy implementation. It is because CGE model use general equilibrium in which this theory of general equilibrium explaining about inter-relation among markets in the economy system. CGE model was introduced in 1960s known as Johansen model. Next, it is expanded into various models such as: ORANI Model, General Trade Analysis Project (GTAP Model, and Applied General Equilibrium (AGE Model. In Indonesia, there are CGE ORANI Model, Wayang, Indonesia-E3 and IRCGE. CGE Model is created by assumption of perfect competition. Consumer maximizes utility, producer maximizes profit, and company maximizes zero profit condition.

  20. Advances in parallel computer technology for desktop atmospheric dispersion models

    Energy Technology Data Exchange (ETDEWEB)

    Bian, X.; Ionescu-Niscov, S.; Fast, J.D. [Pacific Northwest National Lab., Richland, WA (United States); Allwine, K.J. [Allwine Enviornmental Serv., Richland, WA (United States)

    1996-12-31

    Desktop models are those models used by analysts with varied backgrounds, for performing, for example, air quality assessment and emergency response activities. These models must be robust, well documented, have minimal and well controlled user inputs, and have clear outputs. Existing coarse-grained parallel computers can provide significant increases in computation speed in desktop atmospheric dispersion modeling without considerable increases in hardware cost. This increased speed will allow for significant improvements to be made in the scientific foundations of these applied models, in the form of more advanced diffusion schemes and better representation of the wind and turbulence fields. This is especially attractive for emergency response applications where speed and accuracy are of utmost importance. This paper describes one particular application of coarse-grained parallel computer technology to a desktop complex terrain atmospheric dispersion modeling system. By comparing performance characteristics of the coarse-grained parallel version of the model with the single-processor version, we will demonstrate that applying coarse-grained parallel computer technology to desktop atmospheric dispersion modeling systems will allow us to address critical issues facing future requirements of this class of dispersion models.

  1. Vectorial Preisach-type model designed for parallel computing

    Energy Technology Data Exchange (ETDEWEB)

    Stancu, Alexandru [Department of Solid State and Theoretical Physics, Al. I. Cuza University, Blvd. Carol I, 11, 700506 Iasi (Romania)]. E-mail: alstancu@uaic.ro; Stoleriu, Laurentiu [Department of Solid State and Theoretical Physics, Al. I. Cuza University, Blvd. Carol I, 11, 700506 Iasi (Romania); Andrei, Petru [Electrical and Computer Engineering, Florida State University, Tallahassee, FL (United States); Electrical and Computer Engineering, Florida A and M University, Tallahassee, FL (United States)

    2007-09-15

    Most of the hysteresis phenomenological models are scalar, while all the magnetization processes are vectorial. The vector models-phenomenological or micromagnetic (physical)-are time consuming and sometimes difficult to implement. In this paper, we introduce a new vector Preisach-type model that uses micromagnetic results to simulate the magnetic response of a system of several tens of thousands of pseudo-particles. The model has a modular structure that allows easy implementation for parallel computing.

  2. Computer generation of structural models of amorphous Si and Ge

    Science.gov (United States)

    Wooten, F.; Winer, K.; Weaire, D.

    1985-04-01

    We have developed and applied a computer algorithm that generates realistic random-network models of a-Si with periodic boundary conditions. These are the first models to have correlation functions that show no serious deiscrepancy with experiment. The algorithm provides a much-needed systematic approach to model construction that can be used to generate models of a large class of amorphous materials.

  3. Paradox of integration -- a computational model

    CERN Document Server

    Krawczyk, Malgorzata J

    2016-01-01

    The paradoxical aspect of integration of a social group has been highlighted by Peter Blau (Exchange and Power in Social Life, Wiley and Sons, 1964). During the integration process, the group members simultaneously compete for social status and play the role of the audience. Here we show that when the competition prevails over the desire of approval, a sharp transition breaks all friendly relations. However, as was described by Blau, people with high status are inclined to bother more with acceptance of others; this is achieved by praising others and revealing her/his own weak points. In our model, this action smooths the transition and improves interpersonal relations.

  4. Paradox of integration-A computational model

    Science.gov (United States)

    Krawczyk, Małgorzata J.; Kułakowski, Krzysztof

    2017-02-01

    The paradoxical aspect of integration of a social group has been highlighted by Blau (1964). During the integration process, the group members simultaneously compete for social status and play the role of the audience. Here we show that when the competition prevails over the desire of approval, a sharp transition breaks all friendly relations. However, as was described by Blau, people with high status are inclined to bother more with acceptance of others; this is achieved by praising others and revealing her/his own weak points. In our model, this action smooths the transition and improves interpersonal relations.

  5. Emerging Trends and Statistical Analysis in Computational Modeling in Agriculture

    Directory of Open Access Journals (Sweden)

    Sunil Kumar

    2015-03-01

    Full Text Available In this paper the authors have tried to describe emerging trend in computational modelling used in the sphere of agriculture. Agricultural computational modelling with the use of intelligence techniques for computing the agricultural output by providing minimum input data to lessen the time through cutting down the multi locational field trials and also the labours and other inputs is getting momentum. Development of locally suitable integrated farming systems (IFS is the utmost need of the day, particularly in India where about 95% farms are under small and marginal holding size. Optimization of the size and number of the various enterprises to the desired IFS model for a particular set of agro-climate is essential components of the research to sustain the agricultural productivity for not only filling the stomach of the bourgeoning population of the country, but also to enhance the nutritional security and farms return for quality life. Review of literature pertaining to emerging trends in computational modelling applied in field of agriculture is done and described below for the purpose of understanding its trends mechanism behavior and its applications. Computational modelling is increasingly effective for designing and analysis of the system. Computa-tional modelling is an important tool to analyses the effect of different scenarios of climate and management options on the farming systems and its interaction among themselves. Further, authors have also highlighted the applications of computational modeling in integrated farming system, crops, weather, soil, climate, horticulture and statistical used in agriculture which can show the path to the agriculture researcher and rural farming community to replace some of the traditional techniques.

  6. [Excessive computer usage in adolescents--results of a psychometric evaluation].

    Science.gov (United States)

    Grüsser, Sabine M; Thalemann, Ralf; Albrecht, Ulrike; Thalemann, Carolin N

    2005-03-01

    Excessive computer and video game playing among children is being critically discussed from a pedagogic and public health point of view. To date, no reliable data for this phenomenon in Germany exists. In the present study, the excessive usage of computer and video games is seen as a rewarding behavior which can, due to learning mechanisms, become a prominent and inadequate strategy for children to cope with negative emotions like frustration, uneasiness and fears. In the survey, 323 children ranging in age from 11 to 14 years were asked about their video game playing behavior. Criteria for excessive computer and video game playing were developed in accordance with the criteria for dependency and pathological gambling (DSM-IV, ICD-10). Data show that 9.3% (N = 30) of the children fulfill all criteria for excessive computer and video game playing. Furthermore, these children differ from their class mates with respect to watching television, communication patterns, the ability to concentrate in school lectures and the preferred strategies coping with negative emotions. In accordance with findings in studies about substance-related addiction, data suggest that excessive computer and video game players use their excessive rewarding behavior specifically as an inadequate stress coping strategy.

  7. Importance of facial physical attractiveness of audiovisual models in descriptions and preferences of children and adolescents.

    Science.gov (United States)

    Ruiz, Cristina; Conde, Elena; Torres, Esteban

    2005-08-01

    We performed a cross-sectional study with three age groups (8, 14, and 17 years) to evaluate developmental differences in stereotyped beliefs about physical attractiveness and the value of this as perceived by the participants. Given the current importance of television in the development of social knowledge, television models were used. The children and adolescents were asked to evaluate, using bipolar open scales, the physical attractiveness, likeableness, generosity, intelligence, fun, and altruism of 12 television models of both sexes, previously selected by judges, as well as the desire to resemble or feel close to the models. Analysis showed developmental differences across age groups both in the concept of physical attractiveness and in stereotyped beliefs about this. As in other areas of social knowledge, the younger children's responses were bipolar, global, and much more stereotyped, while the adolescents introduced subtle distinctions and elaborated their responses. Nevertheless, physical attractiveness appeared a desirable characteristic for all age groups.

  8. Does the Model Matter? Comparing Video Self-Modeling and Video Adult Modeling for Task Acquisition and Maintenance by Adolescents with Autism Spectrum Disorders

    Science.gov (United States)

    Cihak, David F.; Schrader, Linda

    2009-01-01

    The purpose of this study was to compare the effectiveness and efficiency of learning and maintaining vocational chain tasks using video self-modeling and video adult modeling instruction. Four adolescents with autism spectrum disorders were taught vocational and prevocational skills. Although both video modeling conditions were effective for…

  9. Computational Modeling of Cell Survival Using VHDL

    Directory of Open Access Journals (Sweden)

    Shruti Jain1,

    2010-01-01

    Full Text Available The model for cell survival has been implemented using VeryHigh Speed Integrated Circuit Hardware DescriptionLanguage (VHDL (Xilinx Tool taking three input signals:Tumor necrosis factor-α (TNF, Epidermal growth factor(EGF and Insulin. Cell survival has been regulated by theinteraction of five proteins viz P13K, TNFR1, EGFR, IRS andIKK in a network. In the absence of any one, in protein networkleads to cell death. For the EGF input signal the proteins likeMEK, ERK, AkT, Rac & JNK have been important forregulation of cell survival. Similarly for TNF and Insulin inputsignal proteins like NFκB, AkT, XIAP, JNK, MAP3K & MK2and MEK, ERK, AkT, Rac, mTOR & JNK respectively havebeen important for regulation of cell survival.

  10. Computer Forensics Field Triage Process Model

    Directory of Open Access Journals (Sweden)

    Marcus K. Rogers

    2006-06-01

    Full Text Available With the proliferation of digital based evidence, the need for the timely identification, analysis and interpretation of digital evidence is becoming more crucial. In many investigations critical information is required while at the scene or within a short period of time - measured in hours as opposed to days. The traditional cyber forensics approach of seizing a system(s/media, transporting it to the lab, making a forensic image(s, and then searching the entire system for potential evidence, is no longer appropriate in some circumstances. In cases such as child abductions, pedophiles, missing or exploited persons, time is of the essence. In these types of cases, investigators dealing with the suspect or crime scene need investigative leads quickly; in some cases it is the difference between life and death for the victim(s. The Cyber Forensic Field Triage Process Model (CFFTPM proposes an onsite or field approach for providing the identification, analysis and interpretation of digital evidence in a short time frame, without the requirement of having to take the system(s/media back to the lab for an in-depth examination or acquiring a complete forensic image(s. The proposed model adheres to commonly held forensic principles, and does not negate the ability that once the initial field triage is concluded, the system(s/storage media be transported back to a lab environment for a more thorough examination and analysis. The CFFTPM has been successfully used in various real world cases, and its investigative importance and pragmatic approach has been amply demonstrated. Furthermore, the derived evidence from these cases has not been challenged in the court proceedings where it has been introduced. The current article describes the CFFTPM in detail, discusses the model’s forensic soundness, investigative support capabilities and practical considerations.

  11. A propagation model of computer virus with nonlinear vaccination probability

    Science.gov (United States)

    Gan, Chenquan; Yang, Xiaofan; Liu, Wanping; Zhu, Qingyi

    2014-01-01

    This paper is intended to examine the effect of vaccination on the spread of computer viruses. For that purpose, a novel computer virus propagation model, which incorporates a nonlinear vaccination probability, is proposed. A qualitative analysis of this model reveals that, depending on the value of the basic reproduction number, either the virus-free equilibrium or the viral equilibrium is globally asymptotically stable. The results of simulation experiments not only demonstrate the validity of our model, but also show the effectiveness of nonlinear vaccination strategies. Through parameter analysis, some effective strategies for eradicating viruses are suggested.

  12. A Separated Domain-Based Kernel Model for Trusted Computing

    Institute of Scientific and Technical Information of China (English)

    FANG Yanxiang; SHEN Changxiang; XU Jingdong; WU Gongyi

    2006-01-01

    This paper fist gives an investigation on trusted computing on mainstream operation system (OS). Based on the observations, it is pointed out that Trusted Computing cannot be achieved due to the lack of separation mechanism of the components in mainstream OS. In order to provide a kind of separation mechanism, this paper proposes a separated domain-based kernel model (SDBKM), and this model is verified by non-interference theory. By monitoring and simplifying the trust dependence between domains, this model can solve problems in trust measurement such as deny of service (DoS) attack, Host security, and reduce the overhead of measurement.

  13. Predicting room acoustical behavior with the ODEON computer model

    DEFF Research Database (Denmark)

    Naylor, Graham; Rindel, Jens Holger

    1992-01-01

    for discrepancies are discussed. These discrepancies indicate areas in which the computational model has to be improved, and highlight some shortcomings of current room acoustical survey methods. The effects of various calculation parameters (e.g., number of rays, early reflection order) are also briefly considered.......The computational bases of the ODEON model for room acoustics are described in a companion paper. The model is implemented for general use of a PC. In this paper, various technical features of the program relevant to the acoustical design process are presented. These include interactive...

  14. Dynamic Distribution Model with Prime Granularity for Parallel Computing

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Dynamic distribution model is one of the best schemes for parallel volume rendering. However, in homogeneous cluster system, since the granularity is traditionally identical, all processors communicate almost simultaneously and computation load may lose balance. Due to problems above, a dynamic distribution model with prime granularity for parallel computing is presented.Granularities of each processor are relatively prime, and related theories are introduced. A high parallel performance can be achieved by minimizing network competition and using a load balancing strategy that ensures all processors finish almost simultaneously. Based on Master-Slave-Gleaner (MSG) scheme, the parallel Splatting Algorithm for volume rendering is used to test the model on IBM Cluster 1350 system. The experimental results show that the model can bring a considerable improvement in performance, including computation efficiency, total execution time, speed, and load balancing.

  15. Computational modeling of neural activities for statistical inference

    CERN Document Server

    Kolossa, Antonio

    2016-01-01

    This authored monograph supplies empirical evidence for the Bayesian brain hypothesis by modeling event-related potentials (ERP) of the human electroencephalogram (EEG) during successive trials in cognitive tasks. The employed observer models are useful to compute probability distributions over observable events and hidden states, depending on which are present in the respective tasks. Bayesian model selection is then used to choose the model which best explains the ERP amplitude fluctuations. Thus, this book constitutes a decisive step towards a better understanding of the neural coding and computing of probabilities following Bayesian rules. The target audience primarily comprises research experts in the field of computational neurosciences, but the book may also be beneficial for graduate students who want to specialize in this field. .

  16. Operation of the computer model for microenvironment solar exposure

    Science.gov (United States)

    Gillis, J. R.; Bourassa, R. J.; Gruenbaum, P. E.

    1995-01-01

    A computer model for microenvironmental solar exposure was developed to predict solar exposure to satellite surfaces which may shadow or reflect on one another. This document describes the technical features of the model as well as instructions for the installation and use of the program.

  17. Development of computer simulation models for pedestrian subsystem impact tests

    NARCIS (Netherlands)

    Kant, R.; Konosu, A.; Ishikawa, H.

    2000-01-01

    The European Enhanced Vehicle-safety Committee (EEVC/WG10 and WG17) proposed three component subsystem tests for cars to assess pedestrian protection. The objective of this study is to develop computer simulation models of the EEVC pedestrian subsystem tests. These models are available to develop a

  18. A Multi-Agent Immunology Model for Security Computer

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper presents a computer immunology model for computersecurity , whose main components are defined as idea of Multi-Agent. It introduces the n at ural immune system on the principle, discusses the idea and characteristics of Mu lti-Agent. It gives a system model, and describes the structure and function of each agent. Also, the communication method between agents is described.

  19. Interrogative Model of Inquiry and Computer-Supported Collaborative Learning.

    Science.gov (United States)

    Hakkarainen, Kai; Sintonen, Matti

    2002-01-01

    Examines how the Interrogative Model of Inquiry (I-Model), developed for the purposes of epistemology and philosophy of science, could be applied to analyze elementary school students' process of inquiry in computer-supported learning. Suggests that the interrogative approach to inquiry can be productively applied for conceptualizing inquiry in…

  20. Computer-Aided Template for Model Reuse, Development and Maintenance

    DEFF Research Database (Denmark)

    Fedorova, Marina; Sin, Gürkan; Gani, Rafiqul

    2014-01-01

    A template-based approach for model development is presented in this work. Based on a model decomposition technique, the computer-aided template concept has been developed. This concept is implemented as a software tool , which provides a user-friendly interface for following the workflow steps, ...

  1. Modeling and Computer Simulation of AN Insurance Policy:

    Science.gov (United States)

    Acharyya, Muktish; Acharyya, Ajanta Bhowal

    We have developed a model for a life-insurance policy. In this model, the net gain is calculated by computer simulation for a particular type of lifetime distribution function. We observed that the net gain becomes maximum for a particular value of upper age for last premium.

  2. Modelling Emission from Building Materials with Computational Fluid Dynamics

    DEFF Research Database (Denmark)

    Topp, Claus; Nielsen, Peter V.; Heiselberg, Per

    This paper presents a numerical model that by means of computational fluid dynamics (CFD) is capable of dealing with both pollutant transport across the boundary layer and internal diffusion in the source without prior knowledge of which is the limiting process. The model provides the concentration...

  3. Computational modeling of aerosol deposition in respiratory tract: a review.

    Science.gov (United States)

    Rostami, Ali A

    2009-02-01

    This review article is intended to serve as an overview of the current status of the computational tools and approaches available for predicting respiratory-tract dosimetry of inhaled particulate matter. There are two groups of computational models available, depending on the intended use. The whole-lung models are designed to provide deposition prediction for the whole lung, from the oronasal cavities to the pulmonary region. The whole-lung models are generally semi-empirical and hence provide more reliable results but within the range of parameters used for empirical correlations. The local deposition or computational fluid dynamics (CFD)-based models, on the other hand, utilize comprehensive theoretical and computational approaches but are often limited to upper respiratory tracts. They are based on theoretical principles and are applicable to a wider range of parameters, but less accurate. One of the difficulties with modeling of aerosol deposition in human lung is related to the complexity of the airways geometry and the limited morphometric data available. Another difficulty corresponds to simulation of the realistic physiological conditions of lung environment. Furthermore, complex physical and chemical phenomena associated with dense and multicomponent aerosols complicate the modeling tasks. All of these issues are addressed in this review. The progress made in each area in the last three decades and the challenges ahead are discussed along with some suggestions for future direction. The following subjects are covered in this review: introduction, aerosol deposition mechanisms, elements of a computational model, respiratory-tract geometry models, whole-lung models, CFD based models, cigarette smoke deposition models, and conclusion.

  4. Perceived problems with computer gaming and Internet use are associated with poorer social relations in adolescence

    DEFF Research Database (Denmark)

    Rasmussen, Mette; Meilstrup, Charlotte Riebeling; Bendtsen, Pernille

    2015-01-01

    communication are associated with young people's social relations. METHODS: Cross-sectional questionnaire survey in 13 schools in the city of Aarhus, Denmark, in 2009. Response rate 89 %, n = 2,100 students in grades 5, 7, and 9. Independent variables were perceived problems related to computer gaming...... and Internet use, respectively. Outcomes were measures of structural (number of days/week with friends, number of friends) and functional (confidence in others, being bullied, bullying others) dimensions of student's social relations. RESULTS: Perception of problems related to computer gaming were associated......OBJECTIVES: Young people's engagement in electronic gaming and Internet communication have caused concerns about potential harmful effects on their social relations, but the literature is inconclusive. The aim of this paper was to examine whether perceived problems with computer gaming and Internet...

  5. Basic definitions for discrete modeling of computer worms epidemics

    Directory of Open Access Journals (Sweden)

    P. Guevara

    2015-04-01

    Full Text Available The information technologies have evolved in such a way that communication between computers or hosts has become common, so much that the worldwide organization (governments and corporations depends on it; what could happen if these computers stop working for a long time is catastrophic. Unfortunately, networks are attacked by malware such as viruses and worms that could collapse the system. This has served as motivation for the formal study of computer worms and epidemics to develop strategies for prevention and protection; this is why in this paper, before analyzing epidemiological models, a set of formal definitions based on set theory and functions is proposed for describing 21 concepts used in the study of worms. These definitions provide a basis for future qualitative research on the behavior of computer worms, and quantitative for the study of their epidemiological models.

  6. Linking Experimental Characterization and Computational Modeling in Microstructural Evolution

    Energy Technology Data Exchange (ETDEWEB)

    Demirel, Melik Cumhur [Univ. of California, Berkeley, CA (United States)

    2002-06-01

    It is known that by controlling microstructural development, desirable properties of materials can be achieved. The main objective of our research is to understand and control interface dominated material properties, and finally, to verify experimental results with computer simulations. In order to accomplish this objective, we studied the grain growth in detail with experimental techniques and computational simulations. We obtained 5170-grain data from an Aluminum-film (120μm thick) with a columnar grain structure from the Electron Backscattered Diffraction (EBSD) measurements. Experimentally obtained starting microstructure and grain boundary properties are input for the three-dimensional grain growth simulation. In the computational model, minimization of the interface energy is the driving force for the grain boundary motion. The computed evolved microstructure is compared with the final experimental microstructure, after annealing at 550 ºC. Two different measures were introduced as methods of comparing experimental and computed microstructures. Modeling with anisotropic mobility explains a significant amount of mismatch between experiment and isotropic modeling. We have shown that isotropic modeling has very little predictive value. Microstructural evolution in columnar Aluminum foils can be correctly modeled with anisotropic parameters. We observed a strong similarity

  7. Linking Experimental Characterization and Computational Modeling in Microstructural Evolution

    Energy Technology Data Exchange (ETDEWEB)

    Demirel, Melik Cumhar [Univ. of Pittsburgh, PA (United States)

    2002-06-01

    It is known that by controlling microstructural development, desirable properties of materials can be achieved. The main objective of our research is to understand and control interface dominated material properties, and finally, to verify experimental results with computer simulations. In order to accomplish this objective, we studied the grain growth in detail with experimental techniques and computational simulations. We obtained 5170-grain data from an Aluminum-film (120μm thick) with a columnar grain structure from the Electron Backscattered Diffraction (EBSD) measurements. Experimentally obtained starting microstructure and grain boundary properties are input for the three-dimensional grain growth simulation. In the computational model, minimization of the interface energy is the driving force for the grain boundary motion. The computed evolved microstructure is compared with the final experimental microstructure, after annealing at 550 ºC. Two different measures were introduced as methods of comparing experimental and computed microstructures. Modeling with anisotropic mobility explains a significant amount of mismatch between experiment and isotropic modeling. We have shown that isotropic modeling has very little predictive value. Microstructural evolution in columnar Aluminum foils can be correctly modeled with anisotropic parameters. We observed a strong similarity between grain growth experiments and anisotropic three-dimensional simulations.

  8. Phase Computations and Phase Models for Discrete Molecular Oscillators.

    OpenAIRE

    Demir, Alper; Şuvak, Önder

    2012-01-01

    RESEARCH Open Access Phase computations and phase models for discrete molecular oscillators Onder Suvak* and Alper Demir Abstract Background: Biochemical oscillators perform crucial functions in cells, e.g., they set up circadian clocks. The dynamical behavior of oscillators is best described and analyzed in terms of the scalar quantity, phase. A rigorous and useful definition for phase is based on the so-called isochrons of oscillators. Phase computation techniques for ...

  9. Special Issue: Big data and predictive computational modeling

    Science.gov (United States)

    Koutsourelakis, P. S.; Zabaras, N.; Girolami, M.

    2016-09-01

    The motivation for this special issue stems from the symposium on "Big Data and Predictive Computational Modeling" that took place at the Institute for Advanced Study, Technical University of Munich, during May 18-21, 2015. With a mindset firmly grounded in computational discovery, but a polychromatic set of viewpoints, several leading scientists, from physics and chemistry, biology, engineering, applied mathematics, scientific computing, neuroscience, statistics and machine learning, engaged in discussions and exchanged ideas for four days. This special issue contains a subset of the presentations. Video and slides of all the presentations are available on the TUM-IAS website http://www.tum-ias.de/bigdata2015/.

  10. Modeling the contribution of personality, social identity and social norms to problematic Facebook use in adolescents.

    Science.gov (United States)

    Marino, Claudia; Vieno, Alessio; Pastore, Massimiliano; Albery, Ian P; Frings, Daniel; Spada, Marcantonio M

    2016-12-01

    Facebook is the most popular social networking site in the world providing the opportunity to maintain and/or establish relationships, to share media contents and experiences with friends, and to easily communicate with them. Despite the resources and the innovative social features offered by Facebook research has emerged indicating that its use may become problematic, with negative consequences on personal psycho-social well-being, especially among adolescents and young adults. The main aim of this study was to examine the unique contribution of personality traits and social influence processes (i.e. subjective norms, group norms, and social identity) to perceived frequency of Facebook Use and Problematic Facebook Use in a sample of adolescents. A total of 968 Italian adolescents participated in the study. Structural equation modeling showed that emotional stability, extraversion, conscientiousness and norms directly predicted Problematic Facebook Use, whereas gender, group norms and social identity predicted perceived frequency of Facebook use. In conclusion, both personal and social variables appear to explain perceived frequency of Facebook use and Problematic Facebook Use among adolescents, and should be taken into account by researchers and educational practitioners.

  11. Methodology for characterizing modeling and discretization uncertainties in computational simulation

    Energy Technology Data Exchange (ETDEWEB)

    ALVIN,KENNETH F.; OBERKAMPF,WILLIAM L.; RUTHERFORD,BRIAN M.; DIEGERT,KATHLEEN V.

    2000-03-01

    This research effort focuses on methodology for quantifying the effects of model uncertainty and discretization error on computational modeling and simulation. The work is directed towards developing methodologies which treat model form assumptions within an overall framework for uncertainty quantification, for the purpose of developing estimates of total prediction uncertainty. The present effort consists of work in three areas: framework development for sources of uncertainty and error in the modeling and simulation process which impact model structure; model uncertainty assessment and propagation through Bayesian inference methods; and discretization error estimation within the context of non-deterministic analysis.

  12. Integrated Multiscale Modeling of Molecular Computing Devices

    Energy Technology Data Exchange (ETDEWEB)

    Weinan E

    2012-03-29

    The main bottleneck in modeling transport in molecular devices is to develop the correct formulation of the problem and efficient algorithms for analyzing the electronic structure and dynamics using, for example, the time-dependent density functional theory. We have divided this task into several steps. The first step is to developing the right mathematical formulation and numerical algorithms for analyzing the electronic structure using density functional theory. The second step is to study time-dependent density functional theory, particularly the far-field boundary conditions. The third step is to study electronic transport in molecular devices. We are now at the end of the first step. Under DOE support, we have made subtantial progress in developing linear scaling and sub-linear scaling algorithms for electronic structure analysis. Although there has been a huge amount of effort in the past on developing linear scaling algorithms, most of the algorithms developed suffer from the lack of robustness and controllable accuracy. We have made the following progress: (1) We have analyzed thoroughly the localization properties of the wave-functions. We have developed a clear understanding of the physical as well as mathematical origin of the decay properties. One important conclusion is that even for metals, one can choose wavefunctions that decay faster than any algebraic power. (2) We have developed algorithms that make use of these localization properties. Our algorithms are based on non-orthogonal formulations of the density functional theory. Our key contribution is to add a localization step into the algorithm. The addition of this localization step makes the algorithm quite robust and much more accurate. Moreover, we can control the accuracy of these algorithms by changing the numerical parameters. (3) We have considerably improved the Fermi operator expansion (FOE) approach. Through pole expansion, we have developed the optimal scaling FOE algorithm.

  13. Computational fluid dynamics modeling for emergency preparedness and response

    Energy Technology Data Exchange (ETDEWEB)

    Lee, R.L.; Albritton, J.R.; Ermak, D.L.; Kim, J.

    1995-02-01

    Computational fluid dynamics (CFD) has (CFD) has played an increasing in the improvement of atmospheric dispersion modeling. This is because many dispersion models are now driven by meteorological fields generated from CFD models or, in numerical weather prediction`s terminology, prognostic models. Whereas most dispersion models typically involve one or a few scalar, uncoupled equations, the prognostic equations are a set of highly-couple equations whose solution requires a significant level of computational power. Recent advances in computer hardware and software have enabled modestly-priced, high performance, workstations to exhibit the equivalent computation power of some mainframes. Thus desktop-class machines that were limited to performing dispersion calculations driven by diagnostic wind fields may now be used to calculate complex flows using prognostic CFD models. The Release and Advisory Capability (ARAC) program at Lawrence Livermore National Laboratory (LLNL) has, for the past several years, taken advantage of the improvements in hardware technology to develop a national emergency response capability based on executing diagnostic models on workstations. Diagnostic models that provide wind fields are, in general, simple to implement, robust and require minimal time for execution. Because these models typically contain little physics beyond mass-conservation, their performance is extremely sensitive to the quantity and quality of input meteorological data and, in spite of their utility, can be applied with confidence to only modestly complex flows. We are now embarking on a development program to incorporate prognostic models to generate, in real-time, the meteorological fields for the dispersion models. In contrast to diagnostic models, prognostic models are physically-based and are capable of incorporating many physical processes to treat highly complex flow scenarios.

  14. Adolescence as a critical stage in the MCH Life Course Model: commentary for the Leadership Education in Adolescent Health (LEAH) interdisciplinary training program projects.

    Science.gov (United States)

    Shlafer, Rebecca; Hergenroeder, Albert C; Jean Emans, S; Rickert, Vaughn I; Adger, Hoover; Spear, Bonnie; Irwin, Charles E; Kreipe, Richard E; Walker, Leslie R; Resnick, Michael D

    2014-02-01

    The Life Course Perspective (LCP), or Model, is now a guiding framework in Maternal and Child Health (MCH) activities, including training, supported by the Health Resources and Services Administration's Maternal and Child Health Bureau. As generally applied, the LCP tends to focus on pre- through post-natal stages, infancy and early childhood, with less attention paid to adolescents as either the "maternal" or "child" elements of MCH discourse. Adolescence is a distinct developmental period with unique opportunities for the development of health, competence and capacity and not merely a transitional phase between childhood and adulthood. Adequately addressing adolescents' emergent and ongoing health needs requires well-trained and specialized professionals who recognize the unique role of this developmental period in the LCP.

  15. Intrapair Similarity of Computer Self-Efficacy in Turkish Adolescent Twins

    Science.gov (United States)

    Deryakulu, Deniz; Mcilroy, David; Ursavas, Ömer Faruk; Çaliskan, Erkan

    2016-01-01

    The purpose of this study is to investigate genetic and environmental influences on computer self-efficacy. A total of 165 Turkish twin-pairs participated in the study. Participants' mean age was 12.45 (SD = 1.82). The results of paired t-test comparisons showed no significant differences in monozygotic, and both same-sex and opposite-sex…

  16. Soft Tissue Biomechanical Modeling for Computer Assisted Surgery

    CERN Document Server

    2012-01-01

      This volume focuses on the biomechanical modeling of biological tissues in the context of Computer Assisted Surgery (CAS). More specifically, deformable soft tissues are addressed since they are the subject of the most recent developments in this field. The pioneering works on this CAS topic date from the 1980's, with applications in orthopaedics and biomechanical models of bones. More recently, however, biomechanical models of soft tissues have been proposed since most of the human body is made of soft organs that can be deformed by the surgical gesture. Such models are much more complicated to handle since the tissues can be subject to large deformations (non-linear geometrical framework) as well as complex stress/strain relationships (non-linear mechanical framework). Part 1 of the volume presents biomechanical models that have been developed in a CAS context and used during surgery. This is particularly new since most of the soft tissues models already proposed concern Computer Assisted Planning, with ...

  17. Importance of Computer Model Validation in Pyroprocessing Technology Development

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Y. E.; Li, Hui; Yim, M. S. [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2014-05-15

    In this research, we developed a plan for experimental validation of one of the computer models developed for ER process modeling, i. e., the ERAD code. Several candidate surrogate materials are selected for the experiment considering the chemical and physical properties. Molten salt-based pyroprocessing technology is being examined internationally as an alternative to treat spent nuclear fuel over aqueous technology. The central process in pyroprocessing is electrorefining(ER) which separates uranium from transuranic elements and fission products present in spent nuclear fuel. ER is a widely used process in the minerals industry to purify impure metals. Studies of ER by using actual spent nuclear fuel materials are problematic for both technical and political reasons. Therefore, the initial effort for ER process optimization is made by using computer models. A number of models have been developed for this purpose. But as validation of these models is incomplete and often times problematic, the simulation results from these models are inherently uncertain.

  18. On the Computational Expressiveness of Model Transformation Languages

    DEFF Research Database (Denmark)

    Al-Sibahi, Ahmad Salim

    2015-01-01

    Common folklore in the model transformation community dictates that most transformation languages are Turing-complete. It is however seldom that a proof or an explanation is provided on why such property holds; due to the widely different features and execution models in these language, it is not......Common folklore in the model transformation community dictates that most transformation languages are Turing-complete. It is however seldom that a proof or an explanation is provided on why such property holds; due to the widely different features and execution models in these language......, it is not immediately obvious what their computational expressiveness is. In this paper we present an analysis that clarifies the computational expressiveness of a large number of model transformation languages. The analysis confirms the folklore for all model transformation languages, except the bidirectional ones...

  19. Computer modelling for ecosystem service assessment: Chapter 4.4

    Science.gov (United States)

    Dunford, Robert; Harrison, Paula; Bagstad, Kenneth J.

    2017-01-01

    Computer models are simplified representations of the environment that allow biophysical, ecological, and/or socio-economic characteristics to be quantified and explored. Modelling approaches differ from mapping approaches (Chapter 5) as (i) they are not forcibly spatial (although many models do produce spatial outputs); (ii) they focus on understanding and quantifying the interactions between different components of social and/or environmental systems and (iii)

  20. Correlation between hyoid bone position and airway dimensions in Chinese adolescents by cone beam computed tomography analysis.

    Science.gov (United States)

    Jiang, Y-Y

    2016-07-01

    This study aimed to investigate the correlation between upper airway dimensions and hyoid bone position in Chinese adolescents based on cone beam computed tomography (CBCT) images. CBCT images from a total of 254 study subjects were included. The upper airway and hyoid bone parameters were measured by Materialism's interactive medical image control system (MIMICS) v.16.01 (Materialise, Leuven, Belgium). The airway dimensions were evaluated in terms of volume, cross-sectional area (CSA), mean CSA, length, anteroposterior dimension of the cross-section (AP), lateral dimension of the cross-section (LAT), and LAT/AP ratio. The hyoid bone position was evaluated using eight linear parameters and two angular parameters. Facial characteristics were evaluated using three linear parameters and three angular parameters. Most hyoid bone position parameters (especially the distance between the hyoid bone and hard palate) were significantly associated with most airway dimension parameters. Significant correlations were also observed between the different facial characteristic parameters and hyoid bone position parameters. Most airway dimension parameters showed significant correlations with linear facial parameters, but they displayed significant correlations with only a few angular facial parameters. These findings provide an understanding of the static relationship between the hyoid bone position and airway dimensions, which may serve as a reference for surgeons before orthodontic or orthognathic surgery.

  1. Applying the one minute preceptor model to pediatric and adolescent gynecology education.

    Science.gov (United States)

    Lockspeiser, Tai M; Kaul, Paritosh

    2015-04-01

    There are multiple challenges to teaching in the clinical setting. The One Minute Preceptor is a learner-centered model for effective and efficient teaching in a clinical setting that can help to overcome these challenges. It consists of 5 microskills: get a commitment; probe for supporting evidence; teach general rules; reinforce what was right; correct mistakes. This article illustrates with case vignettes the use of these microskills for the busy Pediatric and Adolescent Gynecology clinician.

  2. Genetic Algorithm Modeling with GPU Parallel Computing Technology

    CERN Document Server

    Cavuoti, Stefano; Brescia, Massimo; Pescapé, Antonio; Longo, Giuseppe; Ventre, Giorgio

    2012-01-01

    We present a multi-purpose genetic algorithm, designed and implemented with GPGPU / CUDA parallel computing technology. The model was derived from a multi-core CPU serial implementation, named GAME, already scientifically successfully tested and validated on astrophysical massive data classification problems, through a web application resource (DAMEWARE), specialized in data mining based on Machine Learning paradigms. Since genetic algorithms are inherently parallel, the GPGPU computing paradigm has provided an exploit of the internal training features of the model, permitting a strong optimization in terms of processing performances and scalability.

  3. DNA computation model to solve 0-1 programming problem.

    Science.gov (United States)

    Zhang, Fengyue; Yin, Zhixiang; Liu, Bo; Xu, Jin

    2004-01-01

    0-1 programming problem is an important problem in opsearch with very widespread applications. In this paper, a new DNA computation model utilizing solution-based and surface-based methods is presented to solve the 0-1 programming problem. This model contains the major benefits of both solution-based and surface-based methods; including vast parallelism, extraordinary information density and ease of operation. The result, verified by biological experimentation, revealed the potential of DNA computation in solving complex programming problem.

  4. Mathematical modelling in the computer-aided process planning

    Science.gov (United States)

    Mitin, S.; Bochkarev, P.

    2016-04-01

    This paper presents new approaches to organization of manufacturing preparation and mathematical models related to development of the computer-aided multi product process planning (CAMPP) system. CAMPP system has some peculiarities compared to the existing computer-aided process planning (CAPP) systems: fully formalized developing of the machining operations; a capacity to create and to formalize the interrelationships among design, process planning and process implementation; procedures for consideration of the real manufacturing conditions. The paper describes the structure of the CAMPP system and shows the mathematical models and methods to formalize the design procedures.

  5. Computational molecular basis for improved silica surface complexation models

    Energy Technology Data Exchange (ETDEWEB)

    Sahai, Nita; Rosso, Kevin M.

    2006-06-06

    The acidity and reactivity of surface sites on amorphous and crystalline polymorphs of silica and other oxides control their thermodynamic stability and kinetic reactivity towards reactants in surface-controlled processes of environmental, industrial, biomedical and technological relevance. Recent advances in computational methodologies such as CPMD and increasing computer power combined with spectroscopic measurements are now making it possible to link, with an impressive degree of accuracy, the molecular-level description of these processes to phenomenological, surface complexation models The future challenge now lies in linking mesoscale properties at the nanometer scale to phenomenological models that will afford a more intuitive understanding of the systems under consideration.

  6. Intelligent Cost Modeling Based on Soft Computing for Avionics Systems

    Institute of Scientific and Technical Information of China (English)

    ZHU Li-li; LI Zhuang-sheng; XU Zong-ze

    2006-01-01

    In parametric cost estimating, objections to using statistical Cost Estimating Relationships (CERs) and parametric models include problems of low statistical significance due to limited data points, biases in the underlying data, and lack of robustness. Soft Computing (SC) technologies are used for building intelligent cost models. The SC models are systemically evaluated based on their training and prediction of the historical cost data of airborne avionics systems. Results indicating the strengths and weakness of each model are presented. In general, the intelligent cost models have higher prediction precision, better data adaptability, and stronger self-learning capability than the regression CERs.

  7. Computational Modelling of Piston Ring Dynamics in 3D

    Directory of Open Access Journals (Sweden)

    Dlugoš Jozef

    2014-12-01

    Full Text Available Advanced computational models of a piston assembly based on the level of virtual prototypes require a detailed description of piston ring behaviour. Considering these requirements, the piston rings operate in regimes that cannot, in general, be simplified into an axisymmetric model. The piston and the cylinder liner do not have a perfect round shape, mainly due to machining tolerances and external thermo-mechanical loads. If the ring cannot follow the liner deformations, a local loss of contact occurs resulting in blow-by and increased consumption of lubricant oil in the engine. Current computational models are unable to implement such effects. The paper focuses on the development of a flexible 3D piston ring model based on the Timoshenko beam theory using the multibody system (MBS. The MBS model is compared to the finite element method (FEM solution.

  8. A mathematical model of a computational problem solving system

    Science.gov (United States)

    Aris, Teh Noranis Mohd; Nazeer, Shahrin Azuan

    2015-05-01

    This paper presents a mathematical model based on fuzzy logic for a computational problem solving system. The fuzzy logic uses truth degrees as a mathematical model to represent vague algorithm. The fuzzy logic mathematical model consists of fuzzy solution and fuzzy optimization modules. The algorithm is evaluated based on a software metrics calculation that produces the fuzzy set membership. The fuzzy solution mathematical model is integrated in the fuzzy inference engine that predicts various solutions to computational problems. The solution is extracted from a fuzzy rule base. Then, the solutions are evaluated based on a software metrics calculation that produces the level of fuzzy set membership. The fuzzy optimization mathematical model is integrated in the recommendation generation engine that generate the optimize solution.

  9. Computational modeling of drug response with applications to neuroscience.

    Science.gov (United States)

    Herwig, Ralf

    2014-12-01

    The development of novel high-throughput technologies has opened up the opportunity to deeply characterize patient tissues at various molecular levels and has given rise to a paradigm shift in medicine towards personalized therapies. Computational analysis plays a pivotal role in integrating the various genome data and understanding the cellular response to a drug. Based on that data, molecular models can be constructed that incorporate the known downstream effects of drug-targeted receptor molecules and that predict optimal therapy decisions. In this article, we describe the different steps in the conceptual framework of computational modeling. We review resources that hold information on molecular pathways that build the basis for constructing the model interaction maps, highlight network analysis concepts that have been helpful in identifying predictive disease patterns, and introduce the basic concepts of kinetic modeling. Finally, we illustrate this framework with selected studies related to the modeling of important target pathways affected by drugs.

  10. Cloud Computing Adoption Model for Universities to Increase ICT Proficiency

    Directory of Open Access Journals (Sweden)

    Safiya Okai

    2014-08-01

    Full Text Available Universities around the world especially those in developing countries are faced with the problem of delivering the level of information and communications technology (ICT needed to facilitate teaching, learning, research, and development activities ideal in a typical university, which is needed to meet educational needs in-line with advancement in technology and the growing dependence on IT. This is mainly due to the high cost involved in providing and maintaining the needed hardware and software. A technology such as cloud computing that delivers on demand provisioning of IT resources on a pay per use basis can be used to address this problem. Cloud computing promises better delivery of IT services as well as availability whenever and wherever needed at reduced costs with users paying only as much as they consume through the services of cloud service providers. The cloud technology reduces complexity while increasing speed and quality of IT services provided; however, despite these benefits the challenges that come with its adoption have left many sectors especially the higher education skeptical in committing to this technology. This article identifies the reasons for the slow rate of adoption of cloud computing at university level, discusses the challenges faced and proposes a cloud computing adoption model that contains strategic guidelines to overcome the major challenges identified and a roadmap for the successful adoption of cloud computing by universities. The model was tested in one of the universities and found to be both useful and appropriate for adopting cloud computing at university level.

  11. Sex-Related Online Behaviors, Perceived Peer Norms and Adolescents' Experience with Sexual Behavior: Testing an Integrative Model.

    Science.gov (United States)

    Doornwaard, Suzan M; ter Bogt, Tom F M; Reitz, Ellen; van den Eijnden, Regina J J M

    2015-01-01

    Research on the role of sex-related Internet use in adolescents' sexual development has often isolated the Internet and online behaviors from other, offline influencing factors in adolescents' lives, such as processes in the peer domain. The aim of this study was to test an integrative model explaining how receptive (i.e., use of sexually explicit Internet material [SEIM]) and interactive (i.e., use of social networking sites [SNS]) sex-related online behaviors interrelate with perceived peer norms in predicting adolescents' experience with sexual behavior. Structural equation modeling on longitudinal data from 1,132 Dutch adolescents (M(age) T1 = 13.95; range 11-17; 52.7% boys) demonstrated concurrent, direct, and indirect effects between sex-related online behaviors, perceived peer norms, and experience with sexual behavior. SEIM use (among boys) and SNS use (among boys and girls) predicted increases in adolescents' perceptions of peer approval of sexual behavior and/or in their estimates of the numbers of sexually active peers. These perceptions, in turn, predicted increases in adolescents' level of experience with sexual behavior at the end of the study. Boys' SNS use also directly predicted increased levels of experience with sexual behavior. These findings highlight the need for multisystemic research and intervention development to promote adolescents' sexual health.

  12. FCJ-131 Pervasive Computing and Prosopopoietic Modelling – Notes on computed function and creative action

    Directory of Open Access Journals (Sweden)

    Anders Michelsen

    2011-12-01

    Full Text Available This article treats the philosophical underpinnings of the notions of ubiquity and pervasive computing from a historical perspective. The current focus on these notions reflects the ever increasing impact of new media and the underlying complexity of computed function in the broad sense of ICT that have spread vertiginiously since Mark Weiser coined the term ‘pervasive’, e.g., digitalised sensoring, monitoring, effectuation, intelligence, and display. Whereas Weiser’s original perspective may seem fulfilled since computing is everywhere, in his and Seely Brown’s (1997 terms, ‘invisible’, on the horizon, ’calm’, it also points to a much more important and slightly different perspective: that of creative action upon novel forms of artifice. Most importantly for this article, ubiquity and pervasive computing is seen to point to the continuous existence throughout the computational heritage since the mid-20th century of a paradoxical distinction/complicity between the technical organisation of computed function and the human Being, in the sense of creative action upon such function. This paradoxical distinction/complicity promotes a chiastic (Merleau-Ponty relationship of extension of one into the other. It also indicates a generative creation that itself points to important issues of ontology with methodological implications for the design of computing. In this article these implications will be conceptualised as prosopopoietic modeling on the basis of Bernward Joerges introduction of the classical rhetoric term of ’prosopopoeia’ into the debate on large technological systems. First, the paper introduces the paradoxical distinction/complicity by debating Gilbert Simondon’s notion of a ‘margin of indeterminacy’ vis-a-vis computing. Second, it debates the idea of prosopopoietic modeling, pointing to a principal role of the paradoxical distinction/complicity within the computational heritage in three cases: a. Prosopopoietic

  13. Optimal, scalable forward models for computing gravity anomalies

    CERN Document Server

    May, Dave A

    2011-01-01

    We describe three approaches for computing a gravity signal from a density anomaly. The first approach consists of the classical "summation" technique, whilst the remaining two methods solve the Poisson problem for the gravitational potential using either a Finite Element (FE) discretization employing a multilevel preconditioner, or a Green's function evaluated with the Fast Multipole Method (FMM). The methods utilizing the PDE formulation described here differ from previously published approaches used in gravity modeling in that they are optimal, implying that both the memory and computational time required scale linearly with respect to the number of unknowns in the potential field. Additionally, all of the implementations presented here are developed such that the computations can be performed in a massively parallel, distributed memory computing environment. Through numerical experiments, we compare the methods on the basis of their discretization error, CPU time and parallel scalability. We demonstrate t...

  14. A cognitive computational model inspired by the immune system response.

    Science.gov (United States)

    Abdo Abd Al-Hady, Mohamed; Badr, Amr Ahmed; Mostafa, Mostafa Abd Al-Azim

    2014-01-01

    The immune system has a cognitive ability to differentiate between healthy and unhealthy cells. The immune system response (ISR) is stimulated by a disorder in the temporary fuzzy state that is oscillating between the healthy and unhealthy states. However, modeling the immune system is an enormous challenge; the paper introduces an extensive summary of how the immune system response functions, as an overview of a complex topic, to present the immune system as a cognitive intelligent agent. The homogeneity and perfection of the natural immune system have been always standing out as the sought-after model we attempted to imitate while building our proposed model of cognitive architecture. The paper divides the ISR into four logical phases: setting a computational architectural diagram for each phase, proceeding from functional perspectives (input, process, and output), and their consequences. The proposed architecture components are defined by matching biological operations with computational functions and hence with the framework of the paper. On the other hand, the architecture focuses on the interoperability of main theoretical immunological perspectives (classic, cognitive, and danger theory), as related to computer science terminologies. The paper presents a descriptive model of immune system, to figure out the nature of response, deemed to be intrinsic for building a hybrid computational model based on a cognitive intelligent agent perspective and inspired by the natural biology. To that end, this paper highlights the ISR phases as applied to a case study on hepatitis C virus, meanwhile illustrating our proposed architecture perspective.

  15. Systematic Development of the YouRAction program, a computer-tailored Physical Activity promotion intervention for Dutch adolescents, targeting personal motivations and environmental opportunities

    Directory of Open Access Journals (Sweden)

    Prins Richard G

    2010-08-01

    Full Text Available Abstract Background Increasing physical activity (PA among adolescents is an important health promotion goal. PA has numerous positive health effects, but the majority of Dutch adolescents do not meet PA requirements. The present paper describes the systematic development of a theory-based computer-tailored intervention, YouRAction, which targets individual and environmental factors determining PA among adolescents. Design The intervention development was guided by the Intervention Mapping protocol, in order to define clear program objectives, theoretical methods and practical strategies, ensure systematic program planning and pilot-testing, and anticipate on implementation and evaluation. Two versions of YouRAction were developed: one that targets individual determinants and an extended version that also provides feedback on opportunities to be active in the neighbourhood. Key determinants that were targeted included: knowledge and awareness, attitudes, self-efficacy and subjective norms. The extended version also addressed perceived availability of neighbourhood PA facilities. Both versions aimed to increase levels of moderate-to-vigorous PA among adolescents. The intervention structure was based on self-regulation theory, comprising of five steps in the process of successful goal pursuit. Monitoring of PA behaviour and behavioural and normative feedback were used to increase awareness of PA behaviour; motivation was enhanced by targeting self-efficacy and attitudes, by means of various interactive strategies, such as web movies; the perceived environment was targeted by visualizing opportunities to be active in an interactive geographical map of the home environment; in the goal setting phase, the adolescents were guided in setting a goal and developing an action plan to achieve this goal; in the phase of active goal pursuit adolescents try to achieve their goal and in the evaluation phase the achievements are evaluated. Based on the results

  16. COMPUTING

    CERN Document Server

    I. Fisk

    2010-01-01

    Introduction It has been a very active quarter in Computing with interesting progress in all areas. The activity level at the computing facilities, driven by both organised processing from data operations and user analysis, has been steadily increasing. The large-scale production of simulated events that has been progressing throughout the fall is wrapping-up and reprocessing with pile-up will continue. A large reprocessing of all the proton-proton data has just been released and another will follow shortly. The number of analysis jobs by users each day, that was already hitting the computing model expectations at the time of ICHEP, is now 33% higher. We are expecting a busy holiday break to ensure samples are ready in time for the winter conferences. Heavy Ion An activity that is still in progress is computing for the heavy-ion program. The heavy-ion events are collected without zero suppression, so the event size is much large at roughly 11 MB per event of RAW. The central collisions are more complex and...

  17. COMPUTING

    CERN Multimedia

    M. Kasemann P. McBride Edited by M-C. Sawley with contributions from: P. Kreuzer D. Bonacorsi S. Belforte F. Wuerthwein L. Bauerdick K. Lassila-Perini M-C. Sawley

    Introduction More than seventy CMS collaborators attended the Computing and Offline Workshop in San Diego, California, April 20-24th to discuss the state of readiness of software and computing for collisions. Focus and priority were given to preparations for data taking and providing room for ample dialog between groups involved in Commissioning, Data Operations, Analysis and MC Production. Throughout the workshop, aspects of software, operating procedures and issues addressing all parts of the computing model were discussed. Plans for the CMS participation in STEP’09, the combined scale testing for all four experiments due in June 2009, were refined. The article in CMS Times by Frank Wuerthwein gave a good recap of the highly collaborative atmosphere of the workshop. Many thanks to UCSD and to the organizers for taking care of this workshop, which resulted in a long list of action items and was definitely a success. A considerable amount of effort and care is invested in the estimate of the comput...

  18. Mathematical and Computational Modeling of Polymer Exchange Membrane Fuel Cells

    Science.gov (United States)

    Ulusoy, Sehribani

    In this thesis a comprehensive review of fuel cell modeling has been given and based on the review, a general mathematical fuel cell model has been developed in order to understand the physical phenomena governing the fuel cell behavior and in order to contribute to the efforts investigating the optimum performance at different operating conditions as well as with different physical parameters. The steady state, isothermal model presented here accounts for the combined effects of mass and species transfer, momentum conservation, electrical current distribution through the gas channels, the electrodes and the membrane, and the electrochemical kinetics of the reactions in the anode and cathode catalyst layers. One of the important features of the model is that it proposes a simpler modified pseudo-homogeneous/agglomerate catalyst layer model which takes the advantage of the simplicity of pseudo-homogenous modeling while taking into account the effects of the agglomerates in the catalyst layer by using experimental geometric parameters published. The computation of the general mathematical model can be accomplished in 3D, 2D and 1D with the proper assumptions. Mainly, there are two computational domains considered in this thesis. The first modeling domain is a 2D Membrane Electrode Assembly (MEA) model including the modified agglomerate/pseudo-homogeneous catalyst layer modeling with consistent treatment of water transport in the MEA while the second domain presents a 3D model with different flow filed designs: straight, stepped and tapered. COMSOL Multiphysics along with Batteries and Fuel Cell Module have been used for 2D & 3D model computations while ANSYS FLUENT PEMFC Module has been used for only 3D two-phase computation. Both models have been validated with experimental data. With 2D MEA model, the effects of temperature and water content of the membrane as well as the equivalent weight of the membrane on the performance have been addressed. 3D COMSOL simulation

  19. Accuracy of computer-aided ultrasound as compared with magnetic resonance imaging in the evaluation of nonalcoholic fatty liver disease in obese and eutrophic adolescents

    Directory of Open Access Journals (Sweden)

    José Hermes Ribas do Nascimento

    2015-08-01

    Full Text Available AbstractObjective:To compare the accuracy of computer-aided ultrasound (US and magnetic resonance imaging (MRI by means of hepatorenal gradient analysis in the evaluation of nonalcoholic fatty liver disease (NAFLD in adolescents.Materials and Methods:This prospective, cross-sectional study evaluated 50 adolescents (aged 11–17 years, including 24 obese and 26 eutrophic individuals. All adolescents underwent computer-aided US, MRI, laboratory tests, and anthropometric evaluation. Sensitivity, specificity, positive and negative predictive values and accuracy were evaluated for both imaging methods, with subsequent generation of the receiver operating characteristic (ROC curve and calculation of the area under the ROC curve to determine the most appropriate cutoff point for the hepatorenal gradient in order to predict the degree of steatosis, utilizing MRI results as the gold-standard.Results:The obese group included 29.2% girls and 70.8% boys, and the eutrophic group, 69.2% girls and 30.8% boys. The prevalence of NAFLD corresponded to 19.2% for the eutrophic group and 83% for the obese group. The ROC curve generated for the hepatorenal gradient with a cutoff point of 13 presented 100% sensitivity and 100% specificity. As the same cutoff point was considered for the eutrophic group, false-positive results were observed in 9.5% of cases (90.5% specificity and false-negative results in 0% (100% sensitivity.Conclusion:Computer-aided US with hepatorenal gradient calculation is a simple and noninvasive technique for semiquantitative evaluation of hepatic echogenicity and could be useful in the follow-up of adolescents with NAFLD, population screening for this disease as well as for clinical studies.

  20. Accuracy of computer-aided ultrasound as compared with magnetic resonance imaging in the evaluation of nonalcoholic fatty liver disease in obese and eutrophic adolescents

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, Jose Hermes Ribas do, E-mail: josehermesnascimento@gmail.com [Instituto Cenecista de Ensino Superior de Santo Angelo (IESA), Santo Angelo, RS (Brazil); Soder, Ricardo Bernardi; Epifanio, Matias; Baldisserotto, Matteo [Pontificia Universidade Catolica do Rio Grande do Sul (InsCer/PUCRS), Porto Alegre, RS (Brazil). Instituto do Cerebro

    2015-07-15

    Objective: to compare the accuracy of computer-aided ultrasound (US) and magnetic resonance imaging (MRI) by means of hepatorenal gradient analysis in the evaluation of nonalcoholic fatty liver disease (NAFLD) in adolescents. Materials and methods: this prospective, cross-sectional study evaluated 50 adolescents (aged 11-17 years), including 24 obese and 26 eutrophic individuals. All adolescents underwent computer-aided US, MRI, laboratory tests, and anthropometric evaluation. Sensitivity, specificity, positive and negative predictive values and accuracy were evaluated for both imaging methods, with subsequent generation of the receiver operating characteristic (ROC) curve and calculation of the area under the ROC curve to determine the most appropriate cutoff point for the hepatorenal gradient in order to predict the degree of steatosis, utilizing MRI results as the gold-standard. Results: the obese group included 29.2% girls and 70.8% boys, and the eutrophic group, 69.2% girls and 30.8% boys. The prevalence of NAFLD corresponded to 19.2% for the eutrophic group and 83% for the obese group. The ROC curve generated for the hepatorenal gradient with a cutoff point of 13 presented 100% sensitivity and 100% specificity. As the same cutoff point was considered for the eutrophic group, false-positive results were observed in 9.5% of cases (90.5% specificity) and false-negative results in 0% (100% sensitivity). Conclusion: computer-aided US with hepatorenal gradient calculation is a simple and noninvasive technique for semiquantitative evaluation of hepatic echogenicity and could be useful in the follow-up of adolescents with NAFLD, population screening for this disease as well as for clinical studies. (author)