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Sample records for understanding behavior dynamics

  1. Understanding the heavy-tailed dynamics in human behavior.

    Science.gov (United States)

    Ross, Gordon J; Jones, Tim

    2015-06-01

    The recent availability of electronic data sets containing large volumes of communication data has made it possible to study human behavior on a larger scale than ever before. From this, it has been discovered that across a diverse range of data sets, the interevent times between consecutive communication events obey heavy-tailed power law dynamics. Explaining this has proved controversial, and two distinct hypotheses have emerged. The first holds that these power laws are fundamental, and arise from the mechanisms such as priority queuing that humans use to schedule tasks. The second holds that they are statistical artifacts which only occur in aggregated data when features such as circadian rhythms and burstiness are ignored. We use a large social media data set to test these hypotheses, and find that although models that incorporate circadian rhythms and burstiness do explain part of the observed heavy tails, there is residual unexplained heavy-tail behavior which suggests a more fundamental cause. Based on this, we develop a quantitative model of human behavior which improves on existing approaches and gives insight into the mechanisms underlying human interactions.

  2. Understanding the dynamics of sustainable social-ecological systems: human behavior, institutions, and regulatory feedback networks.

    Science.gov (United States)

    Anderies, John M

    2015-02-01

    I present a general mathematical modeling framework that can provide a foundation for the study of sustainability in social- ecological systems (SESs). Using basic principles from feedback control and a sequence of specific models from bioeconomics and economic growth, I outline several mathematical and empirical challenges associated with the study of sustainability of SESs. These challenges are categorized into three classes: (1) the social choice of performance measures, (2) uncertainty, and (3) collective action. Finally, I present some opportunities for combining stylized dynamical systems models with empirical data on human behavior and biophysical systems to address practical challenges for the design of effective governance regimes (policy feedbacks) for highly uncertain natural resource systems.

  3. Understanding unusual thermal transport behavior in soft materials under mechanical strain - A molecular dynamics study

    Science.gov (United States)

    Murad, Sohail; Puri, Ishwar K.

    2015-04-01

    Experiments have shown a dependence of the thermal conductivity of soft polymer materials on shear stress, which is common to several applications, such as film processing, fiber spinning, blow molding, and vacuum forming. Experiments reveal that the conductivity initially decreases with shear, but then increases as additional shear rate is applied. Based on molecular principles, we hypothesize that when molecules are initially placed under tension and extended, they disentangle, which reduces the number of points of interaction and diminishes the heat flux. Further molecular stretching increases this flux because the molecules are now better axially aligned. Molecular dynamics simulations confirm this competition and reproduce the inflection in the flux-strain relationship, which has not been previously explained.

  4. Conceptual shifts needed to understand the dynamic interactions of genes, environment, epigenetics, social processes, and behavioral choices.

    Science.gov (United States)

    Jackson, Fatimah L C; Niculescu, Mihai D; Jackson, Robert T

    2013-10-01

    Social and behavioral research in public health is often intimately tied to profound, but frequently neglected, biological influences from underlying genetic, environmental, and epigenetic events. The dynamic interplay between the life, social, and behavioral sciences often remains underappreciated and underutilized in addressing complex diseases and disorders and in developing effective remediation strategies. Using a case-study format, we present examples as to how the inclusion of genetic, environmental, and epigenetic data can augment social and behavioral health research by expanding the parameters of such studies, adding specificity to phenotypic assessments, and providing additional internal control in comparative studies. We highlight the important roles of gene-environment interactions and epigenetics as sources of phenotypic change and as a bridge between the life and social and behavioral sciences in the development of robust interdisciplinary analyses.

  5. Challenges in human behavior understanding

    NARCIS (Netherlands)

    Salah, A.A.; Gevers, T.; Sebe, N.; Vinciarelli, A.

    2010-01-01

    Recent advances in pattern recognition has allowed computer scientists and psychologists to jointly address automatic analysis of of human behavior via computers. The Workshop on Human Behavior Understanding at the International Conference on Pattern Recognition explores a number of different

  6. Understanding Licensing Behavior

    DEFF Research Database (Denmark)

    Cabaleiro, Goretti; Moreira, Solon; Reichstein, Toke

    The potential for rent dissipation has been argued to be the main cause of firms? licensing out behavior being stifled.However, this aspect has been scarcely studied empirically. We draw on rent dissipation arguments, and hypothesize that firms suffering from the not-invented-here (NIH) syndrome...

  7. Understanding Licensing Behavior

    DEFF Research Database (Denmark)

    Cabaleiro, Goretti; Moreira, Solon; Reichstein, Toke

    The potential for rent dissipation has been argued to be the main cause of firms? licensing out behavior being stifled.However, this aspect has been scarcely studied empirically. We draw on rent dissipation arguments, and hypothesize that firms suffering from the not-invented-here (NIH) syndrome,...

  8. Simulating human behavior for understanding and managing environmental resource use

    NARCIS (Netherlands)

    Jager, Wander; Mosler, Hans Joachim

    2007-01-01

    Computer simulation allows for the experimental study of dynamic interactions between human behavior and complex environmental systems. Behavioral determinants and processes as identified in social-scientific theory may be formalized in simulated agents to obtain a better understanding of

  9. Understanding and Modeling Teams As Dynamical Systems

    Directory of Open Access Journals (Sweden)

    Jamie C. Gorman

    2017-07-01

    Full Text Available By its very nature, much of teamwork is distributed across, and not stored within, interdependent people working toward a common goal. In this light, we advocate a systems perspective on teamwork that is based on general coordination principles that are not limited to cognitive, motor, and physiological levels of explanation within the individual. In this article, we present a framework for understanding and modeling teams as dynamical systems and review our empirical findings on teams as dynamical systems. We proceed by (a considering the question of why study teams as dynamical systems, (b considering the meaning of dynamical systems concepts (attractors; perturbation; synchronization; fractals in the context of teams, (c describe empirical studies of team coordination dynamics at the perceptual-motor, cognitive-behavioral, and cognitive-neurophysiological levels of analysis, and (d consider the theoretical and practical implications of this approach, including new kinds of explanations of human performance and real-time analysis and performance modeling. Throughout our discussion of the topics we consider how to describe teamwork using equations and/or modeling techniques that describe the dynamics. Finally, we consider what dynamical equations and models do and do not tell us about human performance in teams and suggest future research directions in this area.

  10. Spatial and temporal dynamics of commercial reef-fish fisheries on the West Florida Shelf: Understanding drivers of fleet behavior and the implications for future management

    Science.gov (United States)

    Cockrell, M.; Murawski, S. A.; Sanchirico, J. N.; O'Farrell, S.; Strelcheck, A.

    2016-02-01

    Spatial and temporal patterns of fishing activity have historically been described over relatively coarse scales or with limited datasets. However, new and innovative approaches for fisheries management will require an understanding of both species population dynamics and fleet behavior at finer spatial and temporal resolution. In this study we describe the spatial and temporal patterns of commercial reef-fish fisheries on the West Florida Shelf (WFS) from 2006-14, using a combination of on-board observer, catch logbook, and vessel satellite tracking data. The satellite tracking data is both high resolution (ie, records from each vessel at least once every hour for the duration of a trip), and required of all federally-permitted reef fish vessels in the Gulf of Mexico, making this a uniquely rich and powerful dataset. Along with spatial and temporal fishery dynamics, we quantified concomitant patterns in fishery economics and catch metrics, such as total landings and catch composition. Fishery patterns were correlated to a number of variables across the vessel, trip, and whole fleet scales, including vessel size, distance from home port, number of days at sea, and days available to fish. Notably, changes in management structure during the years examined (eg, establishment of a seasonal closed area in 2009 and implementation of an individual fishing quota system for Grouper-Tilefish in 2010), as well as emergency spatial closures during the Deepwater Horizon oil spill in 2010, enabled us to examine the impacts of specific management frameworks on the WFS reef-fish fishery. This research highlights the need to better understand the biological, economic, and social impacts within fisheries when managing for conservation and fisheries sustainability. We discuss our results in the context of a changing policy and management landscape for marine and coastal resources in the Gulf of Mexico.

  11. Understanding Consumer Buying Behavior in Africa

    DEFF Research Database (Denmark)

    Kuada, John Ernest; Bujac, Andreea Ioana

    2017-01-01

    Recent economic growth trends in Africa have raised awareness among businesses about the attractiveness of its market potential. There is therefore an increasing academic interest in understanding the attitudes, preferences and behavior of African consumers. This chapter reviews some...

  12. Understanding the Entrepreneurial Process: a Dynamic Approach

    Directory of Open Access Journals (Sweden)

    Vânia Maria Jorge Nassif

    2010-04-01

    Full Text Available There is considerable predominance in the adoption of perspectives based on characteristics in research into entrepreneurship. However, most studies describe the entrepreneur from a static or snapshot approach; very few adopt a dynamic perspective. The aim of this study is to contribute to the enhancement of knowledge concerning entrepreneurial process dynamics through an understanding of the values, characteristics and actions of the entrepreneur over time. By focusing on personal attributes, we have developed a framework that shows the importance of affective and cognitive aspects of entrepreneurs and the way that they evolve during the development of their business.

  13. Understanding behaviors in videos through behavior-specific dictionaries

    DEFF Research Database (Denmark)

    Ren, Huamin; Liu, Weifeng; Olsen, Søren Ingvor

    2018-01-01

    Understanding behaviors is the core of video content analysis, which is highly related to two important applications: abnormal event detection and action recognition. Dictionary learning, as one of the mid-level representations, is an important step to process a video. It has achieved state...

  14. Mission Driven Scene Understanding: Dynamic Environments

    Science.gov (United States)

    2016-06-01

    International Society for Optical Engineering; c2001. 14. Siva P, Russell C, Xiang T, Agapito L. Looking beyond the image : Unsupervised learning for...60,000 was 0.0818 and the training error rate was 0.0273, which means that the CNN had “ learned ” to assign the correct class label to an image , when... images is necessary for scene understanding. Such dynamic environmental conditions (e.g., changing illumination, precipitation, and vegetation) can

  15. Understanding the dynamics of labor shares and inflation

    OpenAIRE

    Karl Whelan; Martina Lawless

    2007-01-01

    Calvo-style models of nominal rigidities currently provide the dominant paradigm for understanding the linkages between wage and price dynamics. Recent empirical implementations stress the idea that these models link inflation to the behavior of the labor share of income. Gali, Gertler, and Lopez-Salido (2001) argue that the model explains the combination of declining inflation and labor shares in euro area. In this paper, we show that with realistic parameters, the canonical Calvo-style mode...

  16. Understanding behaviors in videos through behavior-specific dictionaries

    DEFF Research Database (Denmark)

    Ren, Huamin; Liu, Weifeng; Olsen, Søren Ingvor

    2018-01-01

    Understanding behaviors is the core of video content analysis, which is highly related to two important applications: abnormal event detection and action recognition. Dictionary learning, as one of the mid-level representations, is an important step to process a video. It has achieved state...... scalability needs: A dictionary aimed at an abnormality detection purpose may misdetect normal behavior, which rarely happens in training datasets even though it may be very common in daily life. In contrast, a dictionary aimed at action recognition may misclassify a newcoming action category as an existing...... action. Therefore, our Behavior-Specific Dictionaries (BSDs) are constructed to solve these two applications through a unified framework. To the best of our knowledge, this is the first generalized dictionary algorithm that successfully handle with action recognition and abnormality detection...

  17. Understanding consumer decisions using behavioral economics.

    Science.gov (United States)

    Zandstra, Elizabeth H; Miyapuram, Krishna P; Tobler, Philippe N

    2013-01-01

    Consumers make many decisions in everyday life involving finances, food, and health. It is known from behavioral economics research that people are often driven by short-term gratification, that is, people tend to choose the immediate, albeit smaller reward. But choosing the delayed reward, that is, delaying the gratification, can actually be beneficial. How can we motivate consumers to resist the "now" and invest in their future, leading to sustainable or healthy habits? We review recent developments from behavioral and neuroimaging studies that are relevant for understanding consumer decisions. Further, we present results from our field research that examined whether we can increase the perceived value of a (delayed) environmental benefit using tailored communication, that is, change the way it is framed. More specifically, we investigated whether we can boost the value of an abstract, long-term "green" claim of a product by expressing it as a concrete, short-term benefit. This is a new application area for behavioral economics. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Nonlinear dynamics in human behavior

    Energy Technology Data Exchange (ETDEWEB)

    Huys, Raoul [Centre National de la Recherche Scientifique (CNRS), 13 - Marseille (France); Marseille Univ. (France). Movement Science Inst.; Jirsa, Viktor K. (eds.) [Centre National de la Recherche Scientifique (CNRS), 13 - Marseille (France); Marseille Univ. (France). Movement Science Inst.; Florida Atlantic Univ., Boca Raton, FL (United States). Center for Complex Systems and Brain Sciences

    2010-07-01

    Humans engage in a seemingly endless variety of different behaviors, of which some are found across species, while others are conceived of as typically human. Most generally, behavior comes about through the interplay of various constraints - informational, mechanical, neural, metabolic, and so on - operating at multiple scales in space and time. Over the years, consensus has grown in the research community that, rather than investigating behavior only from bottom up, it may be also well understood in terms of concepts and laws on the phenomenological level. Such top down approach is rooted in theories of synergetics and self-organization using tools from nonlinear dynamics. The present compendium brings together scientists from all over the world that have contributed to the development of their respective fields departing from this background. It provides an introduction to deterministic as well as stochastic dynamical systems and contains applications to motor control and coordination, visual perception and illusion, as well as auditory perception in the context of speech and music. (orig.)

  19. Assessing the Dynamic Behavior of Online Q&A Knowledge Markets: A System Dynamics Approach

    Science.gov (United States)

    Jafari, Mostafa; Hesamamiri, Roozbeh; Sadjadi, Jafar; Bourouni, Atieh

    2012-01-01

    Purpose: The objective of this paper is to propose a holistic dynamic model for understanding the behavior of a complex and internet-based kind of knowledge market by considering both social and economic interactions. Design/methodology/approach: A system dynamics (SD) model is formulated in this study to investigate the dynamic characteristics of…

  20. Understanding slope behavior through microseismic monitoring

    Science.gov (United States)

    Arosio, Diego; Boccolari, Mauro; Longoni, Laura; Papini, Monica; Zanzi, Luigi

    2017-04-01

    It is well known that microseismic activity originates as an elastic stress wave at locations where the material is mechanically unstable. Monitoring techniques focusing on this phenomenon have been studied for over seventy years and are now employed in a wide range of applications. As far as the study of unstable slope is concerned, microseismic monitoring can provide real-time information about fracture formation, propagation and coalescence and may be an appropriate solution to reduce the risk for human settlements when structural mitigation interventions (e.g., rock fall nets and ditches) cannot cope with large rock volumes and high kinetic energies. In this work we present the datasets collected in a 4-year period with a microseismic monitoring network deployed on an unstable rock face in Northern Italy. We mainly focus on the classification and the interpretation of collected signals with the final aim of identifying microseismic events related to the kinematic and dynamic behavior of the slope. We have analyzed signal parameters both in time and frequency domains, spectrograms, polarization of 3-component recordings supported by principal component analysis. Clustering methodologies have been tested in order to develop an automatic classification routine capable to isolate a cluster with most of the events related to slope behavior and to discard all disturbances. The network features both geophones and meteorological sensors so that we could also explore the correlation between microseismic events and meteorological datasets, although no significant relationships emerged. On the contrary, it was found that the majority of the events collected by the network are short-time high-frequency signals generated by electromagnetic activity caused by near and far thunderstorms. Finally, we attempted a preliminary localization of the most promising events according to an oversimplified homogeneous velocity model to get a rough indication about the regions of the

  1. Systematic behavior research for understanding consumer decision making.

    Science.gov (United States)

    Lin, Chin-Feng

    2009-05-01

    This study incorporates means-end chain (MEC) theory and dynamic programming for understanding the implications of consumer decision making. The conceptual framework of this study can help programmers design information systems for analyzing consumption behaviors. Such analyses will provide marketers with meaningful information for formulating marketing strategies. The main contributions of this article are as follows: (1) to enable researchers to obtain information for consumer cognitive hierarchies utilizing an information system, (2) to enhance the functions of traditional MEC methodology and provide an integrated method for analyzing consumption information, and (3) to construct an information system for analyzing consumer decision-making processes.

  2. Understanding the Irradiation Behavior of Zirconium Carbide

    Energy Technology Data Exchange (ETDEWEB)

    Motta, Arthur [Pennsylvania State Univ., University Park, PA (United States); Sridharan, Kumar [Univ. of Wisconsin, Madison, WI (United States); Morgan, Dane [Univ. of Wisconsin, Madison, WI (United States); Szlufarska, Izabela [Univ. of Wisconsin, Madison, WI (United States)

    2013-10-11

    -induced microstructures mapped spatially and temporally, microstructural evolution during post-irradiation annealing, and atomistic modeling of defect formation and transport energetics will provide new, critical understanding about property changes in ZrC. The behavior of materials under irradiation is determined by the balance between damage production, defect clustering, and lattice response. In order to predict those effects at high temperatures so targeted testing can be expanded and extrapolated beyond the known database, it is necessary to determine the defect energetics and mobilities as these control damage accumulation and annealing. In particular, low-temperature irradiations are invaluable for determining the regions of defect mobility. Computer simulation techniques are particularly useful for identifying basic defect properties, especially if closely coupled with a well-constructed and complete experimental database. The close coupling of calculation and experiment in this project will provide mutual benchmarking and allow us to glean a deeper understanding of the irradiation response of ZrC, which can then be applied to the prediction of its behavior in reactor conditions.

  3. Coordination: Neural, Behavioral and Social Dynamics

    CERN Document Server

    Fuchs, Armin

    2008-01-01

    One of the most striking features of Coordination Dynamics is its interdisciplinary character. The problems we are trying to solve in this field range from behavioral phenomena of interlimb coordination and coordination between stimuli and movements (perception-action tasks) through neural activation patterns that can be observed during these tasks to clinical applications and social behavior. It is not surprising that close collaboration among scientists from different fields as psychology, kinesiology, neurology and even physics are imperative to deal with the enormous difficulties we are facing when we try to understand a system as complex as the human brain. The chapters in this volume are not simply write-ups of the lectures given by the experts at the meeting but are written in a way that they give sufficient introductory information to be comprehensible and useful for all interested scientists and students.

  4. Action word understanding and overt motor behavior.

    Science.gov (United States)

    Dalla Volta, Riccardo; Gianelli, Claudia; Campione, Giovanna Cristina; Gentilucci, Maurizio

    2009-07-01

    Is the motor system involved in language processing? In order to clarify this issue, we carried out three behavioral experiments, using go-no-go and choice paradigms. In all the experiments, we used a semantic decision task with an early delivery of the go signal (during processing language material). Italian verbs expressing hand actions, foot actions or an abstract content served as stimuli. Participants executed intransitive (Experiment 1) or transitive (Experiment 2) actions with their right hand in response to the acoustic presentation of action-related verbs and refrained from responding to abstract verbs. The kinematics of the actions was slowed down by hand action-related verbs when compared with foot action-related verbs. In Experiment 3, hand-related and foot-related verbs were presented. Participants responded to hand-related and foot-related verbs with their hand and their foot (compatible condition) and in another block of trials they responded to hand-related and foot-related verbs with their foot and their hand (incompatible condition), respectively. In the compatible condition, the beginning of the action was faster, whereas the kinematics of the action was slower. The present findings suggest complete activation of verb-related motor programs during language processing. The data are discussed in support of the hypothesis that this complete activation is necessary requisite to understand the exact meaning of action words because goal and consequence of the actions are represented.

  5. Understanding Violent Behavior in Children and Adolescents

    Science.gov (United States)

    ... for Families - Vietnamese Violent Behavior in Children and Adolescents No. 55; December 2015 There is a great ... the incidence of violent behavior among children and adolescents. This complex and troubling issue needs to be ...

  6. Understanding and Managing Self-Injurious Behavior.

    Science.gov (United States)

    Zirpoli, Thomas J.; Lloyd, John Wills

    1987-01-01

    The literature review looks at self-injurious behaviors in handicapped students in terms of characteristics, prevalence, etiology (biological, psychological, and as learned behavior), and management including extinction, positive punishment, negative punishment, and reinforcement of other behaviors. Problems in areas of management, administration,…

  7. Understanding Editing Behaviors in Multilingual Wikipedia.

    Science.gov (United States)

    Kim, Suin; Park, Sungjoon; Hale, Scott A; Kim, Sooyoung; Byun, Jeongmin; Oh, Alice H

    2016-01-01

    Multilingualism is common offline, but we have a more limited understanding of the ways multilingualism is displayed online and the roles that multilinguals play in the spread of content between speakers of different languages. We take a computational approach to studying multilingualism using one of the largest user-generated content platforms, Wikipedia. We study multilingualism by collecting and analyzing a large dataset of the content written by multilingual editors of the English, German, and Spanish editions of Wikipedia. This dataset contains over two million paragraphs edited by over 15,000 multilingual users from July 8 to August 9, 2013. We analyze these multilingual editors in terms of their engagement, interests, and language proficiency in their primary and non-primary (secondary) languages and find that the English edition of Wikipedia displays different dynamics from the Spanish and German editions. Users primarily editing the Spanish and German editions make more complex edits than users who edit these editions as a second language. In contrast, users editing the English edition as a second language make edits that are just as complex as the edits by users who primarily edit the English edition. In this way, English serves a special role bringing together content written by multilinguals from many language editions. Nonetheless, language remains a formidable hurdle to the spread of content: we find evidence for a complexity barrier whereby editors are less likely to edit complex content in a second language. In addition, we find that multilinguals are less engaged and show lower levels of language proficiency in their second languages. We also examine the topical interests of multilingual editors and find that there is no significant difference between primary and non-primary editors in each language.

  8. Understanding Editing Behaviors in Multilingual Wikipedia.

    Directory of Open Access Journals (Sweden)

    Suin Kim

    Full Text Available Multilingualism is common offline, but we have a more limited understanding of the ways multilingualism is displayed online and the roles that multilinguals play in the spread of content between speakers of different languages. We take a computational approach to studying multilingualism using one of the largest user-generated content platforms, Wikipedia. We study multilingualism by collecting and analyzing a large dataset of the content written by multilingual editors of the English, German, and Spanish editions of Wikipedia. This dataset contains over two million paragraphs edited by over 15,000 multilingual users from July 8 to August 9, 2013. We analyze these multilingual editors in terms of their engagement, interests, and language proficiency in their primary and non-primary (secondary languages and find that the English edition of Wikipedia displays different dynamics from the Spanish and German editions. Users primarily editing the Spanish and German editions make more complex edits than users who edit these editions as a second language. In contrast, users editing the English edition as a second language make edits that are just as complex as the edits by users who primarily edit the English edition. In this way, English serves a special role bringing together content written by multilinguals from many language editions. Nonetheless, language remains a formidable hurdle to the spread of content: we find evidence for a complexity barrier whereby editors are less likely to edit complex content in a second language. In addition, we find that multilinguals are less engaged and show lower levels of language proficiency in their second languages. We also examine the topical interests of multilingual editors and find that there is no significant difference between primary and non-primary editors in each language.

  9. Understanding the Dynamics of Turkish Nationalism

    Directory of Open Access Journals (Sweden)

    Juan Carlos Razo, Jr.

    2016-04-01

    Full Text Available Many scholars have analyzed Turkish nationalism to understand its progress in the Turkish Republic from different perspectives. While some scholars have fore fronted the importance of cultural and religious aspects of Turkish nationalism, others have emphasized the significance of politics and economics in its formation. Three influential scholars have provided distinctive perceptions on the significance of this nationalism in Turkish society. Carter Vaughn Findley presents a thorough reevaluation of Turkish history in examining various dynamics of Turkish society. While Findley provides an overview on the role of nationalism in the nation’s history, Derya Bayir emphasizes that minorities are not protected in the Turkish legal system because the system aims to preserve Turkish nationalism. In contrast to these two perceptions, Jenny White expresses a modern analysis of the cultural and social aspects of Turkish society with an emphasis on the contrasting outlooks of Muslim nationalists and Kemalists on asserting one’s Turkishness. These three scholarly perspectives concerning the various aspects of Turkish nationalism are essential in assisting readers to grasp the impact of nationalism in Turkish society.

  10. Dynamic Behavior Analysis via Structured Rank Minimization

    NARCIS (Netherlands)

    Georgakis, Christos; Panagakis, Yannis; Pantic, Maja

    2017-01-01

    Human behavior and affect is inherently a dynamic phenomenon involving temporal evolution of patterns manifested through a multiplicity of non-verbal behavioral cues including facial expressions, body postures and gestures, and vocal outbursts. A natural assumption for human behavior modeling is

  11. Understanding dynamic capabilities through knowledge management

    DEFF Research Database (Denmark)

    Nielsen, Anders Paarup

    2006-01-01

    In the paper eight knowledge management activities are identified; knowledge creation, acquisition, capture, assembly, sharing, integration, leverage and exploitation. These activities are assembled into the three dynamic capabilities of knowledge development, knowledge (re)combination and knowle......In the paper eight knowledge management activities are identified; knowledge creation, acquisition, capture, assembly, sharing, integration, leverage and exploitation. These activities are assembled into the three dynamic capabilities of knowledge development, knowledge (re......)combination and knowledge use. The dynamic capabilities and the associated knowledge management activities create flows to and from the firm’s stock of knowledge and they support the creation and use of organizational capabilities....

  12. Understanding Microbial Communities: Function, Structure and Dynamics

    Science.gov (United States)

    2015-02-11

    microbial communities: Function, structure and dynamics’, at the Isaac Newton Institute, University of Cambridge, United Kingdom, from August to...dynamics’, at the Isaac Newton Institute, University of Cambridge, United Kingdom, from August to December 2014. The programme involved over 150...Communities: Function, Structure and Dynamics’, at the Isaac Newton Institute, Cambridge University, UK, from 19th August 2014 – 19th December 2014

  13. Understanding collective dynamics of soft active colloids by binary scattering.

    Science.gov (United States)

    Hanke, Timo; Weber, Christoph A; Frey, Erwin

    2013-11-01

    Collective motion in actively propelled particle systems is triggered on the very local scale by nucleation of coherently moving units consisting of just a handful of particles. These units grow and merge over time, ending up in a long-range ordered, coherently moving state. So far, there exists no bottom-up understanding of how the microscopic dynamics and interactions between the constituents are related to the system's ordering instability. In this paper, we study a class of models for propelled colloids allowing an explicit treatment of the microscopic details of the collision process. Specifically, the model equations are Newtonian equations of motion with separate force terms for particles' driving, dissipation, and interaction forces. Focusing on dilute particle systems, we analyze the binary scattering behavior for these models and determine-based on the microscopic dynamics-the corresponding "collision rule," i.e., the mapping of precollisional velocities and impact parameter on postcollisional velocities. By studying binary scattering we also find that the considered models for active colloids share the same principle for parallel alignment: The first incoming particle (with respect to the center of collision) is aligned to the second particle as a result of the encounter. This behavior distinctively differs from alignment in nondriven dissipative gases. Moreover, the obtained collision rule lends itself as a starting point to apply kinetic theory for propelled particle systems in order to determine the phase boundary to a long-range ordered, coherently moving state. The microscopic origin of the collision rule offers the opportunity to quantitatively scrutinize the predictions of kinetic theory for propelled particle systems through direct comparison with multiparticle simulations. We identify local precursor correlations at the onset of collective motion to constitute the essential determinant for a qualitative and quantitative validity of kinetic

  14. Understanding the behavior of floodplains as human-water systems

    Science.gov (United States)

    Di Baldassarre, G.; Brandimarte, L.

    2012-12-01

    Floodplains are among the most valuable ecosystems for supporting biodiversity and providing services to the environment. Moreover, they are home of approximately one-sixth of the world population as they offer favorable conditions for economic development. As a result, flood disasters currently affect more than 100 million people a year. Sadly, flood losses and fatalities are expected to increase further in many countries because of population growth as well as changes in land use and climate. Given the relevance of floodplain systems, a number of social scientists have examined how the frequency and severity of flooding often determine whether human development in floodplains is desirable or not. Meanwhile, many earth scientists have investigated the impact of human activities (e.g. land-use changes, urbanization, river training) on the frequency and magnitude of floods. In fact, as human activities change the frequency of flooding, the frequency of flooding affects human developments in floodplain areas. Yet, these dynamic interactions between floods and societies and the associated feedback mechanisms remain largely unexplored and poorly understood. As a result, we typically consider humans as external forcing (or boundary condition) without representing the feedback loops and our prediction of future trajectories are therefore extremely limited. This presentation shows a first attempt to understand the behavior of floodplains as coupled human-water systems. In particular, we analyzed a number of long time series of hydrological and population data in the Po River Basin (Italy) to explore the feedback mechanisms, reciprocal effects, surprises, and threshold mechanisms, taking place in floodplain systems. The outcomes of the study enable a better understanding of how the occurrences of floods shape human developments while, at the same time, human activities shape the magnitude and frequency of floods. The presentation also discusses the opportunities offered by

  15. Social Dynamics Management and Functional Behavioral Assessment

    Science.gov (United States)

    Lee, David L.

    2018-01-01

    Managing social dynamics is a critical aspect of creating a positive learning environment in classrooms. In this paper three key interrelated ideas, reinforcement, function, and motivating operations, are discussed with relation to managing social behavior.

  16. Understanding Digital Learning from the Perspective of Systems Dynamics

    Science.gov (United States)

    Kok, Ayse

    2009-01-01

    The System Dynamics approach can be seen as a new way of understanding dynamical phenonema (natural, physical, biological, etc.) that occur in our daily lives taking into consideration not only single pairs of cause-effect variables, but the functioning of the system as a whole. This approach also provides the students with a new understanding in…

  17. Understanding bulk behavior of particulate materials from particle scale simulations

    Science.gov (United States)

    Deng, Xiaoliang

    Particulate materials play an increasingly significant role in various industries, such as pharmaceutical manufacturing, food, mining, and civil engineering. The objective of this research is to better understand bulk behaviors of particulate materials from particle scale simulations. Packing properties of assembly of particles are investigated first, focusing on the effects of particle size, surface energy, and aspect ratio on the coordination number, porosity, and packing structures. The simulation results show that particle sizes, surface energy, and aspect ratio all influence the porosity of packing to various degrees. The heterogeneous force networks within particle assembly under external compressive loading are investigated as well. The results show that coarse-coarse contacts dominate the strong network and coarse-fine contacts dominate the total network. Next, DEM models are developed to simulate the particle dynamics inside a conical screen mill (comil) and magnetically assisted impaction mixer (MAIM), both are important particle processing devices. For comil, the mean residence time (MRT), spatial distribution of particles, along with the collision dynamics between particles as well as particle and vessel geometries are examined as a function of the various operating parameters such as impeller speed, screen hole size, open area, and feed rate. The simulation results can help better understand dry coating experimental results using comil. For MAIM system, the magnetic force is incorporated into the contact model, allowing to describe the interactions between magnets. The simulation results reveal the connections between homogeneity of mixture and particle scale variables such as size of magnets and surface energy of non-magnets. In particular, at the fixed mass ratio of magnets to non-magnets and surface energy the smaller magnets lead to better homogeneity of mixing, which is in good agreement with previously published experimental results. Last but not

  18. Coupled disease-behavior dynamics on complex networks: A review

    Science.gov (United States)

    Wang, Zhen; Andrews, Michael A.; Wu, Zhi-Xi; Wang, Lin; Bauch, Chris T.

    2015-12-01

    It is increasingly recognized that a key component of successful infection control efforts is understanding the complex, two-way interaction between disease dynamics and human behavioral and social dynamics. Human behavior such as contact precautions and social distancing clearly influence disease prevalence, but disease prevalence can in turn alter human behavior, forming a coupled, nonlinear system. Moreover, in many cases, the spatial structure of the population cannot be ignored, such that social and behavioral processes and/or transmission of infection must be represented with complex networks. Research on studying coupled disease-behavior dynamics in complex networks in particular is growing rapidly, and frequently makes use of analysis methods and concepts from statistical physics. Here, we review some of the growing literature in this area. We contrast network-based approaches to homogeneous-mixing approaches, point out how their predictions differ, and describe the rich and often surprising behavior of disease-behavior dynamics on complex networks, and compare them to processes in statistical physics. We discuss how these models can capture the dynamics that characterize many real-world scenarios, thereby suggesting ways that policy makers can better design effective prevention strategies. We also describe the growing sources of digital data that are facilitating research in this area. Finally, we suggest pitfalls which might be faced by researchers in the field, and we suggest several ways in which the field could move forward in the coming years.

  19. Coupled disease-behavior dynamics on complex networks: A review.

    Science.gov (United States)

    Wang, Zhen; Andrews, Michael A; Wu, Zhi-Xi; Wang, Lin; Bauch, Chris T

    2015-12-01

    It is increasingly recognized that a key component of successful infection control efforts is understanding the complex, two-way interaction between disease dynamics and human behavioral and social dynamics. Human behavior such as contact precautions and social distancing clearly influence disease prevalence, but disease prevalence can in turn alter human behavior, forming a coupled, nonlinear system. Moreover, in many cases, the spatial structure of the population cannot be ignored, such that social and behavioral processes and/or transmission of infection must be represented with complex networks. Research on studying coupled disease-behavior dynamics in complex networks in particular is growing rapidly, and frequently makes use of analysis methods and concepts from statistical physics. Here, we review some of the growing literature in this area. We contrast network-based approaches to homogeneous-mixing approaches, point out how their predictions differ, and describe the rich and often surprising behavior of disease-behavior dynamics on complex networks, and compare them to processes in statistical physics. We discuss how these models can capture the dynamics that characterize many real-world scenarios, thereby suggesting ways that policy makers can better design effective prevention strategies. We also describe the growing sources of digital data that are facilitating research in this area. Finally, we suggest pitfalls which might be faced by researchers in the field, and we suggest several ways in which the field could move forward in the coming years. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Tracking Nemo: Help Scientists Understand Zebrafish Behavior.

    Science.gov (United States)

    Tolbert, Tyrone J; Nakayama, Shinnosuke; Porfiri, Maurizio

    2018-02-22

    The advent of automated tracking software has significantly reduced the time required to record movement trajectories, thereby facilitating behavioral studies of zebrafish. However, results are substantially influenced by tracking errors, such as loss and misidentification of individuals. In this study, we present the development of an online citizen science platform, Tracking Nemo, to improve data accuracy on swimming trajectories of zebrafish groups. As an online extension of software for tracking the position of zebrafish from video recordings, Tracking Nemo offers volunteers the opportunity to contribute to science by manually correcting tracked trajectory data from their personal computers. Researchers can upload their videos that require human intervention for correcting and validating the data. Citizen scientists can monitor their contributions through a leaderboard system, which is designed to strengthen participant retention and contribution by tapping into intrinsic and extrinsic motivations. Tracking Nemo is expected to help scientists improve data accuracy through the involvement of citizen scientists, who, in turn, engage in an authentic research activity and learn more about the behavior of zebrafish.

  1. Understanding the complexity of human gait dynamics

    Science.gov (United States)

    Scafetta, Nicola; Marchi, Damiano; West, Bruce J.

    2009-06-01

    Time series of human gait stride intervals exhibit fractal and multifractal properties under several conditions. Records from subjects walking at normal, slow, and fast pace speed are analyzed to determine changes in the fractal scalings as a function of the stress condition of the system. Records from subjects with different age from children to elderly and patients suffering from neurodegenerative disease are analyzed to determine changes in the fractal scalings as a function of the physical maturation or degeneration of the system. A supercentral pattern generator model is presented to simulate the above two properties that are typically found in dynamical network performance: that is, how a dynamical network responds to stress and to evolution.

  2. Understanding calcium dynamics experiments and theory

    CERN Document Server

    Malchow, Dieter

    2003-01-01

    Intracellular Calcium is an important messenger in living cells. Calcium dynamics display complex temporal and spatial structures created by the concentration patterns which are characteristic for a nonlinear system operating far from thermodynamic equilibrium. Written as a set of tutorial reviews on both experimental facts and theoretical modelling, this volume is intended as an introduction and modern reference in the field for graduate students and researchers in biophysics, biochemistry and applied mathematics.

  3. Understanding cooperative behavior in structurally disordered populations

    Science.gov (United States)

    Xu, C.; Zhang, W.; Du, P.; Choi, C. W.; Hui, P. M.

    2016-06-01

    The effects of an inhomogeneous competing environment on the extent of cooperation are studied within the context of a site-diluted evolutionary snowdrift game on a square lattice, with the occupied sites representing the players, both numerically and analytically. The frequency of cooperation ℱ C generally shows a non-monotonic dependence on the fraction of occupied sites ρ, for different values of the payoff parameter r. Slightly diluting a lattice leads to a lower cooperation for small and high values of r. For a range of r, however, dilution leads to an enhanced cooperation. An analytic treatment is developed for ℱC I + ℱC II, with ℱC I emphasizing the importance of the small clusters of players especially for ℱC II from the other players is shown to be inadequate. A local configuration approximation (LCA) that treats the local competing configurations as the variables and amounts to include spatial correlation up to the neighborhood of a player's neighbors is developed. Results of ℱ C ( ρ) and the number of different local configurations from LCA are in good agreement with simulation results. A transparent physical picture of the dynamics stemming from LCA is also presented. The theoretical approach provides a framework that can be readily applied to competing agent-based models in structurally ordered and disordered populations.

  4. Understanding Uranium Behavior in a Reduced Aquifer

    Science.gov (United States)

    Janot, N.; Lezama-Pacheco, J. S.; Williams, K. H.; Bernier-Latmani, R.; Long, P. E.; Davis, J. A.; Fox, P. M.; Yang, L.; Giammar, D.; Cerrato, J. M.; Bargar, J.

    2012-12-01

    Uranium contamination of groundwater is a concern at several US Department of Energy sites, such Old Rifle, CO. Uranium transport in the environment is mainly controlled by its oxidation state, since oxidized U(VI) is relatively mobile, whereas U(IV) is relatively insoluble. Bio-remediation of contaminated aquifers aims at immobilizing uranium in a reduced form. Previous laboratory and field studies have shown that adding electron donor (lactate, acetate, ethanol) to groundwater stimulates the activity of metal- and sulfate-reducing bacteria, which promotes U(VI) reduction in contaminated aquifers. However, obtaining information on chemical and physical forms of U, Fe and S species for sediments biostimulated in the field, as well as kinetic parameters such as U(VI) reduction rate, is challenging due to the low concentration of uranium in the aquifers (typically uranium, iron and sulfur reduction dynamics during such bioremediation episodes. This technique uses in-well columns to obtain direct access to chemical and physical forms of U(IV) produced in the aquifer, evolving microbial communities, and trace and major ion groundwater constituents. While several studies have explored bioreduction of uranium under sulfate-reducing conditions, less attention has been paid to the initial iron-reducing phase, noted as being of particular importance to uranium removal. The aim of this work was to assess the formation of U(IV) during the early stages of a bio-remediation experiment at the Old Rifle site, CO, from early iron-reducing conditions to the transition to sulfate-reducing conditions. Several in-well chromatographic columns packed with sediment were deployed and were sampled at different days after the start of bio-reduction. X-ray absorption spectroscopy and X-ray microscopy were used to obtain information on Fe, S and U speciation and distribution. Chemical extractions of the reduced sediments have also been performed, to determine the rate of Fe(II) and U

  5. Understanding Arsenic Dynamics in Agronomic Systems to ...

    Science.gov (United States)

    This review is on arsenic in agronomic systems, and covers processes that influence the entry of arsenic into the human food supply. The scope is from sources of arsenic (natural and anthropogenic) in soils, biogeochemical and rhizosphere processes that control arsenic speciation and availability, through to mechanisms of uptake by crop plants and potential mitigation strategies. This review makes a case for taking steps to prevent or limit crop uptake of arsenic, wherever possible, and to work toward a long-term solution to the presence of arsenic in agronomic systems. The past two decades have seen important advances in our understanding of how biogeochemical and physiological processes influence human exposure to soil arsenic, and thus must now prompt an informed reconsideration and unification of regulations to protect the quality of agricultural and residential soils. Consumption of staple foods such as rice, beverages such as apple juice, or vegetables grown in historically arsenic-contaminated soils is now recognized as a tangible route of arsenic exposure that, in many cases, is more significant than exposure from drinking water. Understanding the sources of arsenic to crop plants and the factors that influence them is key to reducing exposure now and preventing exposure in future. In addition to the abundant natural sources of arsenic, there are a large number of industrial and agricultural sources of arsenic to the soil; from mining wastes, coal fly

  6. Understanding the Implications of Neural Population Activity on Behavior

    Science.gov (United States)

    Briguglio, John

    Learning how neural activity in the brain leads to the behavior we exhibit is one of the fundamental questions in Neuroscience. In this dissertation, several lines of work are presented to that use principles of neural coding to understand behavior. In one line of work, we formulate the efficient coding hypothesis in a non-traditional manner in order to test human perceptual sensitivity to complex visual textures. We find a striking agreement between how variable a particular texture signal is and how sensitive humans are to its presence. This reveals that the efficient coding hypothesis is still a guiding principle for neural organization beyond the sensory periphery, and that the nature of cortical constraints differs from the peripheral counterpart. In another line of work, we relate frequency discrimination acuity to neural responses from auditory cortex in mice. It has been previously observed that optogenetic manipulation of auditory cortex, in addition to changing neural responses, evokes changes in behavioral frequency discrimination. We are able to account for changes in frequency discrimination acuity on an individual basis by examining the Fisher information from the neural population with and without optogenetic manipulation. In the third line of work, we address the question of what a neural population should encode given that its inputs are responses from another group of neurons. Drawing inspiration from techniques in machine learning, we train Deep Belief Networks on fake retinal data and show the emergence of Garbor-like filters, reminiscent of responses in primary visual cortex. In the last line of work, we model the state of a cortical excitatory-inhibitory network during complex adaptive stimuli. Using a rate model with Wilson-Cowan dynamics, we demonstrate that simple non-linearities in the signal transferred from inhibitory to excitatory neurons can account for real neural recordings taken from auditory cortex. This work establishes and tests

  7. Revolution and Evolution: Understanding Dynamism in Military Affairs

    National Research Council Canada - National Science Library

    Andrews, Timothy D

    1998-01-01

    .... Different dynamics imply different optimal responses to the challenge of change. To the extent that the term Revolution in Military Affairs can be systematically disaggregated, a better understanding of its resulting components may be possible...

  8. Influence of human behavior on cholera dynamics.

    Science.gov (United States)

    Wang, Xueying; Gao, Daozhou; Wang, Jin

    2015-09-01

    This paper is devoted to studying the impact of human behavior on cholera infection. We start with a cholera ordinary differential equation (ODE) model that incorporates human behavior via modeling disease prevalence dependent contact rates for direct and indirect transmissions and infectious host shedding. Local and global dynamics of the model are analyzed with respect to the basic reproduction number. We then extend the ODE model to a reaction-convection-diffusion partial differential equation (PDE) model that accounts for the movement of both human hosts and bacteria. Particularly, we investigate the cholera spreading speed by analyzing the traveling wave solutions of the PDE model, and disease threshold dynamics by numerically evaluating the basic reproduction number of the PDE model. Our results show that human behavior can reduce (a) the endemic and epidemic levels, (b) cholera spreading speeds and (c) the risk of infection (characterized by the basic reproduction number). Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  9. Modeling detour behavior of pedestrian dynamics under different conditions

    Science.gov (United States)

    Qu, Yunchao; Xiao, Yao; Wu, Jianjun; Tang, Tao; Gao, Ziyou

    2018-02-01

    Pedestrian simulation approach has been widely used to reveal the human behavior and evaluate the performance of crowd evacuation. In the existing pedestrian simulation models, the social force model is capable of predicting many collective phenomena. Detour behavior occurs in many cases, and the important behavior is a dominate factor of the crowd evacuation efficiency. However, limited attention has been attracted for analyzing and modeling the characteristics of detour behavior. In this paper, a modified social force model integrated by Voronoi diagram is proposed to calculate the detour direction and preferred velocity. Besides, with the consideration of locations and velocities of neighbor pedestrians, a Logit-based choice model is built to describe the detour direction choice. The proposed model is applied to analyze pedestrian dynamics in a corridor scenario with either unidirectional or bidirectional flow, and a building scenario in real-world. Simulation results show that the modified social force model including detour behavior could reduce the frequency of collision and deadlock, increase the average speed of the crowd, and predict more practical crowd dynamics with detour behavior. This model can also be potentially applied to understand the pedestrian dynamics and design emergent management strategies for crowd evacuations.

  10. Modeling Behavior Dynamics using Computational Psychometrics within Virtual Worlds

    Directory of Open Access Journals (Sweden)

    Pietro eCipresso

    2015-11-01

    Full Text Available In case of fire in a building, how will people behave in the crowd? The behavior of each individual affects the behavior of others and, conversely, each one behaves considering the crowd as a whole and the individual others. In this article, I propose a three-step method to explore a brand new way to study behavior dynamics. The first step relies on the creation of specific situations with standard techniques (such as mental imagery, text, video and audio and an advanced technique (Virtual Reality to manipulate experimental settings. The second step concerns the measurement of behavior in one, two or many individuals focusing on parameters extractions to provide information about the behavior dynamics. Finally, the third step, which uses the parameters collected and measured in the previous two steps in order to simulate possible scenarios to forecast through computational models, understand and explain behavior dynamics at the social level. An experimental study was also included to demonstrate the three-step method and a possible scenario.

  11. Modeling behavior dynamics using computational psychometrics within virtual worlds.

    Science.gov (United States)

    Cipresso, Pietro

    2015-01-01

    In case of fire in a building, how will people behave in the crowd? The behavior of each individual affects the behavior of others and, conversely, each one behaves considering the crowd as a whole and the individual others. In this article, I propose a three-step method to explore a brand new way to study behavior dynamics. The first step relies on the creation of specific situations with standard techniques (such as mental imagery, text, video, and audio) and an advanced technique [Virtual Reality (VR)] to manipulate experimental settings. The second step concerns the measurement of behavior in one, two, or many individuals focusing on parameters extractions to provide information about the behavior dynamics. Finally, the third step, which uses the parameters collected and measured in the previous two steps in order to simulate possible scenarios to forecast through computational models, understand, and explain behavior dynamics at the social level. An experimental study was also included to demonstrate the three-step method and a possible scenario.

  12. High speed photographic study of hot wire dynamic behavior

    Science.gov (United States)

    Sernas, V.; Murphy, A. J.

    1974-01-01

    Investigation of hot wire dynamic behavior under high-current heating aimed at a better understanding of the ignition process, using high-speed photographic techniques for visual observation of the bridgewire itself during high current heating. Tests were conducted with Tophet A bridgewires in an air environment, as well as in a cell of distilled water at room temperature, and with a boron-potassium perchlorate-Viton pyrotechnic against the bridgewire behind a Plexiglas window.

  13. Behavioral variability in an evolutionary theory of behavior dynamics.

    Science.gov (United States)

    Popa, Andrei; McDowell, J J

    2016-03-01

    McDowell's evolutionary theory of behavior dynamics (McDowell, 2004) instantiates populations of behaviors (abstractly represented by integers) that evolve under the selection pressure of the environment in the form of positive reinforcement. Each generation gives rise to the next via low-level Darwinian processes of selection, recombination, and mutation. The emergent patterns can be analyzed and compared to those produced by biological organisms. The purpose of this project was to explore the effects of high mutation rates on behavioral variability in environments that arranged different reinforcer rates and magnitudes. Behavioral variability increased with the rate of mutation. High reinforcer rates and magnitudes reduced these effects; low reinforcer rates and magnitudes augmented them. These results are in agreement with live-organism research on behavioral variability. Various combinations of mutation rates, reinforcer rates, and reinforcer magnitudes produced similar high-level outcomes (equifinality). These findings suggest that the independent variables that describe an experimental condition interact; that is, they do not influence behavior independently. These conclusions have implications for the interpretation of high levels of variability, mathematical undermatching, and the matching theory. The last part of the discussion centers on a potential biological counterpart for the rate of mutation, namely spontaneous fluctuations in the brain's default mode network. © 2016 Society for the Experimental Analysis of Behavior.

  14. Understanding ecohydrological connectivity in savannas: A system dynamics modeling approach

    Science.gov (United States)

    Ecohydrological connectivity is a system-level property that results from the linkages in the networks of water transport through ecosystems, by which feedback effects and other emergent system behaviors may be generated. We created a systems dynamic model that represents primary ecohydrological net...

  15. Understanding How Domestic Violence Affects Behavior in High School Students

    Science.gov (United States)

    Frank, Malika

    2011-01-01

    This paper will provide the reader with an understanding of how domestic violence affects the behavior of high school students. The presentation is designed to provide the reader with a working definition of domestic violence, the rate of occurrence and its effects on high school students. Additionally the paper will summarize the negative effects…

  16. Children's Understanding of Display Rules for Expressive Behavior.

    Science.gov (United States)

    Saarni, Carolyn

    1979-01-01

    Examined how children come to understand that internally experienced affect need not be behaviorally expressed and that the emotion that is expressed is not necessarily what is being felt internally. Sixty elementary school students were interviewed about four interpersonal conflict situations presented in comic strip style but using photographs…

  17. Understanding child sexual behavior problems: a developmental psychopathology framework.

    Science.gov (United States)

    Elkovitch, Natasha; Latzman, Robert D; Hansen, David J; Flood, Mary Fran

    2009-11-01

    Children exhibiting sexual behavior have increasingly gained the attention of child welfare and mental health systems, as well as the scientific community. While a heterogeneous group, children with sexual behavior problems consistently demonstrate a number of problems related to adjustment and overall development. In order to appropriately intervene with these children, a comprehensive understanding of etiology is imperative. The overarching goal of the present paper is to review the extant research on mechanisms associated with the development of problematic sexual behavior in childhood within a developmental psychopathology framework. What is known about normative and nonnormative sexual behavior in childhood is reviewed, highlighting definitional challenges and age-related developmental differences. Further, the relationship between child sexual abuse and child sexual behavior problems is discussed, drawing attention to factors impacting this relationship. Risk factors for child sexual behavior problems, beyond that of sexual abuse, are also reviewed utilizing a transactional-ecological framework. Finally, we conclude with a discussion of implications of a developmental psychopathology perspective on problematic child sexual behaviors to inform future research and intervention efforts. Such implications include the need for attention to normative childhood sexual behavior, developmental sensitivity, and examinations of ecological domain in concert.

  18. Gender consistency and flexibility: using dynamics to understand the relationship between gender and adjustment.

    Science.gov (United States)

    DiDonato, Matthew D; Martin, Carol L; Hessler, Eric E; Amazeen, Polemnia G; Hanish, Laura D; Fabes, Richard A

    2012-04-01

    Controversy surrounds questions regarding the influence of being gender consistent (i.e., having and expressing gendered characteristics that are consistent with one's biological sex) versus being gender flexible (i.e., having and expressing gendered characteristics that vary from masculine to feminine as circumstances arise) on children's adjustment outcomes, such as self-esteem, positive emotion, or behavior problems. Whereas evidence supporting the consistency hypothesis is abundant, little support exists for the flexibility hypothesis. To shed new light on the flexibility hypothesis, we explored children's gendered behavior from a dynamical perspective that highlighted variability and flexibility in addition to employing a conventional approach that emphasized stability and consistency. Conventional mean-level analyses supported the consistency hypothesis by revealing that gender atypical behavior was related to greater maladjustment, and dynamical analyses supported the flexibility hypothesis by showing that flexibility of gendered behavior over time was related to positive adjustment. Integrated analyses showed that gender typical behavior was related to the adjustment of children who were behaviorally inflexible, but not for those who were flexible. These results provided a more comprehensive understanding of the relation between gendered behavior and adjustment in young children and illustrated for the first time the feasibility of applying dynamical analyses to the study of gendered behavior.

  19. Designing Graphs that Promote Both Risk Understanding and Behavior Change.

    Science.gov (United States)

    Okan, Yasmina; Stone, Eric R; Bruine de Bruin, Wändi

    2017-10-03

    Graphs show promise for improving communications about different types of risks, including health risks, financial risks, and climate risks. However, graph designs that are effective at meeting one important risk communication goal (promoting risk-avoidant behaviors) can at the same time compromise another key goal (improving risk understanding). We developed and tested simple bar graphs aimed at accomplishing these two goals simultaneously. We manipulated two design features in graphs, namely, whether graphs depicted the number of people affected by a risk and those at risk of harm ("foreground+background") versus only those affected ("foreground-only"), and the presence versus absence of simple numerical labels above bars. Foreground-only displays were associated with larger risk perceptions and risk-avoidant behavior (i.e., willingness to take a drug for heart attack prevention) than foreground+background displays, regardless of the presence of labels. Foreground-only graphs also hindered risk understanding when labels were not present. However, the presence of labels significantly improved understanding, eliminating the detrimental effect of foreground-only displays. Labels also led to more positive user evaluations of the graphs, but did not affect risk-avoidant behavior. Using process modeling we identified mediators (risk perceptions, understanding, user evaluations) that explained the effect of display type on risk-avoidant behavior. Our findings contribute new evidence to the graph design literature: unlike what was previously feared, we demonstrate that it is possible to design foreground-only graphs that promote intentions for behavior change without a detrimental effect on risk understanding. Implications for the design of graphical risk communications and decision support are discussed. © 2017 Society for Risk Analysis.

  20. Understanding conflict’s dynamics in participatory natural resources management

    NARCIS (Netherlands)

    Idrissou, L.; Aarts, M.N.C.; Leeuwis, C.; Paassen, van A.

    2018-01-01

    This paper investigated conflicts in participatory protected areas management in Benin to better understand their dynamics. This review paper is based on four articles written from three case-studies of conflicts that emerged and evolved in participatory protected areas management in Benin and a

  1. Understanding Learner Agency as a Complex Dynamic System

    Science.gov (United States)

    Mercer, Sarah

    2011-01-01

    This paper attempts to contribute to a fuller understanding of the nature of language learner agency by considering it as a complex dynamic system. The purpose of the study was to explore detailed situated data to examine to what extent it is feasible to view learner agency through the lens of complexity theory. Data were generated through a…

  2. Learning and Understanding System Stability Using Illustrative Dynamic Texture Examples

    Science.gov (United States)

    Liu, Huaping; Xiao, Wei; Zhao, Hongyan; Sun, Fuchun

    2014-01-01

    System stability is a basic concept in courses on dynamic system analysis and control for undergraduate students with computer science backgrounds. Typically, this was taught using a simple simulation example of an inverted pendulum. Unfortunately, many difficult issues arise in the learning and understanding of the concepts of stability,…

  3. Information behavior in dynamic group work contexts

    DEFF Research Database (Denmark)

    Sonnenwald, Diane H.; Pierce, Linda G.

    2000-01-01

    -specific information. The third theme is called `contested collaboration', a phenomenon where team members maintain an outward stance of cooperation but work to further their own interests, at times sabotaging the collaborative effort. These results provide insights to the complex nature of human information behavior......In many dynamic work situations, no single individual can acquire the varied and often rapidly expanding information needed for success. Individuals must work together to collect, analyze, synthesize and disseminate information throughout the work process. Perhaps one of the most dynamic work...... of the situation. Interwoven situational awareness appears to facilitate response to dynamic, constraint-bound situations. The second theme describes the need for dense social networks or frequent communication between participants about the work context and situation, the work process and domain...

  4. Understanding volatility dynamics in the EU-ETS market

    DEFF Research Database (Denmark)

    Sanin, Maria Eugenia; Mansanet-Bataller, Maria; Violante, Francesco

    We study the short-term price behavior of Phase 2 EU emission allowances. We model returns and volatility dynamics, and we demonstrate that a standard ARMAX-GARCH framework is inadequate for this modeling and that the gaussianity assumption is rejected due to a number of outliers. To improve the ...... periods. Thus, authorities face a trade off between disseminating information effectively and promoting market stability....

  5. Understanding dynamics using sensitivity analysis: caveat and solution

    Science.gov (United States)

    2011-01-01

    Background Parametric sensitivity analysis (PSA) has become one of the most commonly used tools in computational systems biology, in which the sensitivity coefficients are used to study the parametric dependence of biological models. As many of these models describe dynamical behaviour of biological systems, the PSA has subsequently been used to elucidate important cellular processes that regulate this dynamics. However, in this paper, we show that the PSA coefficients are not suitable in inferring the mechanisms by which dynamical behaviour arises and in fact it can even lead to incorrect conclusions. Results A careful interpretation of parametric perturbations used in the PSA is presented here to explain the issue of using this analysis in inferring dynamics. In short, the PSA coefficients quantify the integrated change in the system behaviour due to persistent parametric perturbations, and thus the dynamical information of when a parameter perturbation matters is lost. To get around this issue, we present a new sensitivity analysis based on impulse perturbations on system parameters, which is named impulse parametric sensitivity analysis (iPSA). The inability of PSA and the efficacy of iPSA in revealing mechanistic information of a dynamical system are illustrated using two examples involving switch activation. Conclusions The interpretation of the PSA coefficients of dynamical systems should take into account the persistent nature of parametric perturbations involved in the derivation of this analysis. The application of PSA to identify the controlling mechanism of dynamical behaviour can be misleading. By using impulse perturbations, introduced at different times, the iPSA provides the necessary information to understand how dynamics is achieved, i.e. which parameters are essential and when they become important. PMID:21406095

  6. behaviorism: a framework for dynamic data visualization.

    Science.gov (United States)

    Forbes, Angus Graeme; Höllerer, Tobias; Legrady, George

    2010-01-01

    While a number of information visualization software frameworks exist, creating new visualizations, especially those that involve novel visualization metaphors, interaction techniques, data analysis strategies, and specialized rendering algorithms, is still often a difficult process. To facilitate the creation of novel visualizations we present a new software framework, behaviorism, which provides a wide range of flexibility when working with dynamic information on visual, temporal, and ontological levels, but at the same time providing appropriate abstractions which allow developers to create prototypes quickly which can then easily be turned into robust systems. The core of the framework is a set of three interconnected graphs, each with associated operators: a scene graph for high-performance 3D rendering, a data graph for different layers of semantically linked heterogeneous data, and a timing graph for sophisticated control of scheduling, interaction, and animation. In particular, the timing graph provides a unified system to add behaviors to both data and visual elements, as well as to the behaviors themselves. To evaluate the framework we look briefly at three different projects all of which required novel visualizations in different domains, and all of which worked with dynamic data in different ways: an interactive ecological simulation, an information art installation, and an information visualization technique.

  7. Understanding Eating Behaviors through Parental Communication and the Integrative Model of Behavioral Prediction.

    Science.gov (United States)

    Scheinfeld, Emily; Shim, Minsun

    2017-05-01

    Emerging adulthood (EA) is an important yet overlooked period for developing long-term health behaviors. During these years, emerging adults adopt health behaviors that persist throughout life. This study applies the Integrative Model of Behavioral Prediction (IMBP) to examine the role of childhood parental communication in predicting engagement in healthful eating during EA. Participants included 239 college students, ages 18 to 25, from a large university in the southern United States. Participants were recruited and data collection occurred spring 2012. Participants responded to measures to assess perceived parental communication, eating behaviors, attitudes, subjective norms, and behavioral control over healthful eating. SEM and mediation analyses were used to address the hypotheses posited. Data demonstrated that perceived parent-child communication - specifically, its quality and target-specific content - significantly predicted emerging adults' eating behaviors, mediated through subjective norm and perceived behavioral control. This study sets the stage for further exploration and understanding of different ways parental communication influences emerging adults' healthy behavior enactment.

  8. Video-CRM: understanding customer behaviors in stores

    Science.gov (United States)

    Haritaoglu, Ismail; Flickner, Myron; Beymer, David

    2013-03-01

    This paper describes two real-time computer vision systems created 10 years ago that detect and track people in stores to obtain insights of customer behavior while shopping. The first system uses a single color camera to identify shopping groups in the checkout line. Shopping groups are identified by analyzing the inter-body distances coupled with the cashier's activities to detect checkout transactions start and end times. The second system uses multiple overhead narrow-baseline stereo cameras to detect and track people, their body posture and parts to understand customer interactions with products such as "customer picking a product from a shelf". In pilot studies both systems demonstrated real-time performance and sufficient accuracy to enable more detailed understanding of customer behavior and extract actionable real-time retail analytics.

  9. Multi-data Mining for Understanding Leadership Behavior

    Directory of Open Access Journals (Sweden)

    Naohiro Matsumura

    2007-03-01

    Full Text Available We propose an approach for understanding leadership behavior in dot-jp, a non-profit organization, by analyzing heterogeneous multi-data composed of questionnaires and mailing list archives. Attitudes toward leaders were obtained from the questionnaires, and human networks were extracted from the mailing list archives. By integrating the results, we discovered that leaders must receive messages from other people as well as send messages to construct reliable relationships.

  10. Evolutionary Dynamics of Collective Behavior Selection and Drift: Flocking, Collapse, and Oscillation.

    Science.gov (United States)

    Tan, Shaolin; Wang, Yaonan; Chen, Yao; Wang, Zhen

    2016-06-14

    Behavioral choice is ubiquitous across a wide range of interactive decision-making processes and a myriad of scientific disciplines. With regard to this issue, one entitative problem is actually to understand how collective social behaviors form and evolve among populations when they face a variety of conflict alternatives. In this paper, a selection-drift dynamic model is formulated to characterize the behavior imitation and exploration processes in social populations. Based on the proposed framework, several typical behavior evolution patterns, including behavioral flocking, collapse, and oscillation, are reproduced with different kinds of behavior networks. Interestingly, for the selection-drift dynamics on homogeneous symmetric behavior networks, we unveil the phase transition from behavioral flocking to collapse and derive the bifurcation diagram of the evolutionary stable behaviors in social behavior evolution. While via analyzing the survival conditions of the best behavior on heterogeneous symmetric behavior networks, we propose a selection-drift mechanism to guarantee consensus at the optimal behavior. Moreover, when the selection-drift dynamics on asymmetric behavior networks is simulated, it is shown that breaking the symmetry in behavior networks can induce various behavioral oscillations. These obtained results may shed new insights into understanding, detecting, and further controlling how social norm and cultural trends evolve.

  11. Critical dynamics in population vaccinating behavior.

    Science.gov (United States)

    Pananos, A Demetri; Bury, Thomas M; Wang, Clara; Schonfeld, Justin; Mohanty, Sharada P; Nyhan, Brendan; Salathé, Marcel; Bauch, Chris T

    2017-12-26

    Vaccine refusal can lead to renewed outbreaks of previously eliminated diseases and even delay global eradication. Vaccinating decisions exemplify a complex, coupled system where vaccinating behavior and disease dynamics influence one another. Such systems often exhibit critical phenomena-special dynamics close to a tipping point leading to a new dynamical regime. For instance, critical slowing down (declining rate of recovery from small perturbations) may emerge as a tipping point is approached. Here, we collected and geocoded tweets about measles-mumps-rubella vaccine and classified their sentiment using machine-learning algorithms. We also extracted data on measles-related Google searches. We find critical slowing down in the data at the level of California and the United States in the years before and after the 2014-2015 Disneyland, California measles outbreak. Critical slowing down starts growing appreciably several years before the Disneyland outbreak as vaccine uptake declines and the population approaches the tipping point. However, due to the adaptive nature of coupled behavior-disease systems, the population responds to the outbreak by moving away from the tipping point, causing "critical speeding up" whereby resilience to perturbations increases. A mathematical model of measles transmission and vaccine sentiment predicts the same qualitative patterns in the neighborhood of a tipping point to greatly reduced vaccine uptake and large epidemics. These results support the hypothesis that population vaccinating behavior near the disease elimination threshold is a critical phenomenon. Developing new analytical tools to detect these patterns in digital social data might help us identify populations at heightened risk of widespread vaccine refusal. Copyright © 2017 the Author(s). Published by PNAS.

  12. Challenges and opportunities for improved understanding of regional climate dynamics

    Science.gov (United States)

    Collins, Matthew; Minobe, Shoshiro; Barreiro, Marcelo; Bordoni, Simona; Kaspi, Yohai; Kuwano-Yoshida, Akira; Keenlyside, Noel; Manzini, Elisa; O'Reilly, Christopher H.; Sutton, Rowan; Xie, Shang-Ping; Zolina, Olga

    2018-02-01

    Dynamical processes in the atmosphere and ocean are central to determining the large-scale drivers of regional climate change, yet their predictive understanding is poor. Here, we identify three frontline challenges in climate dynamics where significant progress can be made to inform adaptation: response of storms, blocks and jet streams to external forcing; basin-to-basin and tropical-extratropical teleconnections; and the development of non-linear predictive theory. We highlight opportunities and techniques for making immediate progress in these areas, which critically involve the development of high-resolution coupled model simulations, partial coupling or pacemaker experiments, as well as the development and use of dynamical metrics and exploitation of hierarchies of models.

  13. Toward understanding dynamic annealing processes in irradiated ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Myers, Michael Thomas [Texas A & M Univ., College Station, TX (United States)

    2013-05-01

    High energy particle irradiation inevitably generates defects in solids. The ballistic formation and thermalization of the defect creation process occur rapidly, and are believed to be reasonably well understood. However, knowledge of the evolution of defects after damage cascade thermalization, referred to as dynamic annealing, is quite limited. Unraveling the mechanisms associated with dynamic annealing is crucial since such processes play an important role in the formation of stable postirradiation disorder in ion-beam-processing of semiconductors, and determines the “radiation tolerance” of many nuclear materials. The purpose of this dissertation is to further our understanding of the processes involved in dynamic annealing. In order to achieve this, two main tasks are undertaken.

  14. On the dynamic behavior of mineralized tissues

    Science.gov (United States)

    Kulin, Robb Michael

    Mineralized tissues, such as bone and antler, are complex hierarchical materials that have adapted over millennia to optimize strength and fracture resistance for their in vivo applications. As a structural support, skeletal bone primarily acts as a rigid framework that is resistant to fracture, and able to repair damage and adapt to sustained loads during its lifetime. Antler is typically deciduous and subjected to large bending moments and violent impacts during its annual cycle. To date, extensive characterization of the quasi-static mechanical properties of these materials has been performed. However, very little has been done to characterize their dynamic properties, despite the fact that the majority of failures in these materials occur under impact loads. Here, an in depth analysis of the dynamic mechanical behavior of these two materials is presented, using equine bone obtained post-mortem from donors ranging in age from 6 months to 28 years, and antler from the North American Elk. Specimens were tested under compressive strain rates of 10-3, 100, and 103 sec-1 in order to investigate their strain rate dependent compressive response. Fracture toughness experiments were performed using a four-point bending geometry on single and double-notch specimens in order to measure fracture toughness, as well as observe differences in crack propagation between dynamic (˜2x105 MPa˙m1/2/s) and quasi-static (˜0.25 MPa˙m1/2/s) loading rates. After testing, specimens were analyzed using a combination of optical, electron and confocal microscopy. Results indicated that the mechanical response of these materials is highly dependent on loading rate. Decreasing quasi-static fracture toughness is observed with age in bone specimens, while dynamic specimens show no age trends, yet universally decreased fracture toughness compared to those tested quasi-statically. For the first time, rising R-curve behavior in bone was also shown to exist under both quasi-static and dynamic

  15. Population-reaction model and microbial experimental ecosystems for understanding hierarchical dynamics of ecosystems.

    Science.gov (United States)

    Hosoda, Kazufumi; Tsuda, Soichiro; Kadowaki, Kohmei; Nakamura, Yutaka; Nakano, Tadashi; Ishii, Kojiro

    2016-02-01

    Understanding ecosystem dynamics is crucial as contemporary human societies face ecosystem degradation. One of the challenges that needs to be recognized is the complex hierarchical dynamics. Conventional dynamic models in ecology often represent only the population level and have yet to include the dynamics of the sub-organism level, which makes an ecosystem a complex adaptive system that shows characteristic behaviors such as resilience and regime shifts. The neglect of the sub-organism level in the conventional dynamic models would be because integrating multiple hierarchical levels makes the models unnecessarily complex unless supporting experimental data are present. Now that large amounts of molecular and ecological data are increasingly accessible in microbial experimental ecosystems, it is worthwhile to tackle the questions of their complex hierarchical dynamics. Here, we propose an approach that combines microbial experimental ecosystems and a hierarchical dynamic model named population-reaction model. We present a simple microbial experimental ecosystem as an example and show how the system can be analyzed by a population-reaction model. We also show that population-reaction models can be applied to various ecological concepts, such as predator-prey interactions, climate change, evolution, and stability of diversity. Our approach will reveal a path to the general understanding of various ecosystems and organisms. Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  16. Chalk coast dynamics: Implications for understanding rock coast evolution

    Science.gov (United States)

    Moses, Cherith; Robinson, David

    2011-12-01

    Rock cliffs and shore platforms are linked components of the world's coastal zone. Understanding of the dynamics of their relationships has been hindered by the often imperceptible changes that occur within human time scales. The Cretaceous Chalk coasts of northwest Europe, and particularly those of southeast England, are among the most dynamic, and most intensively studied, cliffed rock coasts in the world. Perceptible changes to both cliffs and platforms have been measured on monthly, seasonal, annual and decadal time scales. Through a review of previously published data and the addition of data not previously published, average cliff retreat rates are calculated as 0.49 ± 0.38 m y - 1 and platform erosion rates 3.999 ± 3.208 mm y - 1 . This paper highlights some of the interactions over time and space between process and measurement that continue to limit our understanding of the dynamics of rock coasts; in particular the link between rates of cliff retreat and platform erosion. It concludes by identifying fruitful areas for future research.

  17. Integrating the social sciences to understand human-water dynamics

    Science.gov (United States)

    Carr, G.; Kuil, L., Jr.

    2017-12-01

    Many interesting and exciting socio-hydrological models have been developed in recent years. Such models often aim to capture the dynamic interplay between people and water for a variety of hydrological settings. As such, peoples' behaviours and decisions are brought into the models as drivers of and/or respondents to the hydrological system. To develop and run such models over a sufficiently long time duration to observe how the water-human system evolves the human component is often simplified according to one or two key behaviours, characteristics or decisions (e.g. a decision to move away from a drought or flood area; a decision to pump groundwater, or a decision to plant a less water demanding crop). To simplify the social component, socio-hydrological modellers often pull knowledge and understanding from existing social science theories. This requires them to negotiate complex territory, where social theories may be underdeveloped, contested, dynamically evolving, or case specific and difficult to generalise or upscale. A key question is therefore, how can this process be supported so that the resulting socio-hydrological models adequately describe the system and lead to meaningful understanding of how and why it behaves as it does? Collaborative interdisciplinary research teams that bring together social and natural scientists are likely to be critical. Joint development of the model framework requires specific attention to clarification to expose all underlying assumptions, constructive discussion and negotiation to reach agreement on the modelled system and its boundaries. Mutual benefits to social scientists can be highlighted, i.e. socio-hydrological work can provide insights for further exploring and testing social theories. Collaborative work will also help ensure underlying social theory is made explicit, and may identify ways to include and compare multiple theories. As socio-hydrology progresses towards supporting policy development, approaches that

  18. Understanding the Dynamics of EngagingIinteraction in Public Spaces

    DEFF Research Database (Denmark)

    Dalsgaard, Peter; Dindler, Christian; Halskov, Kim

    We present an analysis of three interactive installations in public spaces, in terms of their support of engagement as an evolving process. In particular, we focus on how engagement unfolds as a dynamic process that may be understood in terms of evolving relations between cultural, physical......, content-related, and social elements of interactive environments. These elements are explored through the literature on engagement with interaction design, and it is argued that, although valuable contributions have been made towards understanding engagement with interactive environments, the ways...

  19. Radiography as a tool in understanding soil insect behavior in turfgrass

    International Nuclear Information System (INIS)

    Villani, M.G.; Wright, R.J.

    1987-01-01

    In an effort to gain a more realistic picture of the events that occur within the soil matrix an x-ray technique has been developed that has been used to study seed insects, parasitized cocoons, and wood boring insects in trees to study soil insect movement and behavior. This technique makes it possible to study the movement of the target insects within simulated or natural soil blocks over time. This method also shows physical properties of the soil matrix: particle size, extent of compaction, differences in soil moisture, horizons, and random soil heterogeneity. Blocks of soil up to 14'' x 17'' x 5'' have been removed from the field and x-rayed in my laboratory using this technique. These radiographs are of sufficient quality to determine the movement of white grubs in situ. Such blocks retain their field characteristics and therefore allow for the careful monitoring and manipulation of the system over relatively long (several months) periods of time. Radiographic data are presented which document the behavior of several white grub species in response to dynamic soil ecosystem processes such as moisture and temperature flux. Additional data on the effects of specific soil insecticides on the behavior of white grubs in the soil and the movement of these insecticides through the soil profile are also presented. The importance of understanding the dynamic interaction of soil insect and soil insecticide provided through x-ray technology, both in understanding white grub behavior in the field and maximizing management efforts is discussed

  20. Neurobiological considerations in understanding behavioral treatments for pathological gambling.

    Science.gov (United States)

    Potenza, Marc N; Balodis, Iris M; Franco, Christine A; Bullock, Scott; Xu, Jiansong; Chung, Tammy; Grant, Jon E

    2013-06-01

    Pathological gambling (PG), a disorder currently categorized as an impulse-control disorder but being considered as a nonsubstance addiction in Diagnostic and Statistical Manual of Mental Disorders (5th ed.) discussions, represents a significant public health concern. Over the past decade, considerable advances have been made with respect to understanding the biological underpinnings of PG. Research has also demonstrated the efficacies of multiple treatments, particularly behavioral therapies, for treating PG. Despite these advances, relatively little is known regarding how biological measures, particularly those assessing brain function, relate to treatments for PG. In this article, we present a conceptual review focusing on the neurobiology of behavioral therapies for PG. To illustrate issues related to study design, we present proof-of-concept preliminary data that link Stroop-related brain activations prior to treatment onset to treatment outcome in individuals with PG receiving a cognitive-behavioral treatment incorporating aspects of imaginal desensitization and motivational interviewing. We conclude with recommendations about current and future directions regarding how to incorporate and translate biological findings into improved therapies for individuals with nonsubstance and substance addictions. 2013 APA, all rights reserved

  1. Neurobiological considerations in understanding behavioral treatments for pathological gambling

    Science.gov (United States)

    Potenza, Marc N.; Balodis, Iris M.; Franco, Christine A.; Bullock, Scott; Xu, Jiansong; Chung, Tammy; Grant, Jon E.

    2013-01-01

    Pathological gambling (PG), a disorder currently categorized as an impulse-control disorder but being considered as a non-substance addiction in DSM-5 discussions, represents a significant public health concern. Over the past decade, considerable advances have been made with respect to understanding the biological underpinnings of PG. Research has also demonstrated the efficacies of multiple treatments, particularly behavioral therapies, for treating PG. Despite these advances, relatively little is known regarding how biological measures, particularly those assessing brain function, relate to treatments for PG. In this article, we present a conceptual review focusing on the neurobiology of behavioral therapies for PG. To illustrate issues related to study design, we present proof-of-concept preliminary data that link Stroop-related brain activations prior to treatment onset to treatment outcome in individuals with PG receiving a cognitive behavioral treatment incorporating aspects of imaginal desensitization and motivational interviewing. We conclude with recommendations about current and future directions regarding how to incorporate and translate biological findings into improved therapies for individuals with non-substance and substance addictions. PMID:23586456

  2. Understanding ion association states and molecular dynamics using infrared spectroscopy

    Science.gov (United States)

    Masser, Hanqing

    A molecular level understanding of the ion transport mechanism within polymer electrolytes is crucial to the further development for advanced energy storage applications. This can be achieved by the identification and quantitative measurement of different ion species in the system and further relating them to the ion conductivity. In the first part of this thesis, research is presented towards understanding the ion association states (free ions, ion pairs and ion aggregates) in ionomer systems, and the correlation of ion association states, ion conduction, polymer dynamics, and morphology. Ion conductivity in ionomers can be improved by lowering glass transition temperature, increasing polymer ion solvation ability, and adjusting ionomer structural variables such as ion content, cation type and side chain structure. These effects are studied in three ionomer systems respectively, using a combination of characterization methods. Fourier Transform Infrared Spectroscopy (FTIR) identifies and quantifies the ion association states. Dielectric Spectroscopy (DRS) characterizes ion conductivity and polymer and ion dynamics. X-ray scattering reveals changes in morphology. The influence of a cation solvating plasticizer on a polyester ionomer is systematically investigated with respect to ion association states, ion and polymer dynamics and morphology. A decrease in the number ratio of ion aggregates with increased plasticizer content and a slight increase at elevated temperature are observed in FTIR. Similar results are also detected by X-ray scattering. As determined from dielectric spectroscopy, ion conductivity increases with plasticizer content, in accordance with the decrease in glass transition temperature. Research on copolymer of poly(ethylene oxide) (PEO) and poly(tetramethylene oxide) (PTMO) based ionomers further develops an understanding of the trade-off between ion solvation and segmental dynamics. Upon the incorporation of PTMO, the majority of the PTMO

  3. Information Dynamics and Emergent Behavior of Heterogeneous-Agent Systems

    National Research Council Canada - National Science Library

    Ya, Nong

    2001-01-01

    This project presents an effort to establish theories and techniques of modeling, analyzing and controlling information dynamics and emergent behavior of heterogeneous-agent systems and demonstrate...

  4. Understanding dynamic friction through spontaneously evolving laboratory earthquakes.

    Science.gov (United States)

    Rubino, V; Rosakis, A J; Lapusta, N

    2017-06-29

    Friction plays a key role in how ruptures unzip faults in the Earth's crust and release waves that cause destructive shaking. Yet dynamic friction evolution is one of the biggest uncertainties in earthquake science. Here we report on novel measurements of evolving local friction during spontaneously developing mini-earthquakes in the laboratory, enabled by our ultrahigh speed full-field imaging technique. The technique captures the evolution of displacements, velocities and stresses of dynamic ruptures, whose rupture speed range from sub-Rayleigh to supershear. The observed friction has complex evolution, featuring initial velocity strengthening followed by substantial velocity weakening. Our measurements are consistent with rate-and-state friction formulations supplemented with flash heating but not with widely used slip-weakening friction laws. This study develops a new approach for measuring local evolution of dynamic friction and has important implications for understanding earthquake hazard since laws governing frictional resistance of faults are vital ingredients in physically-based predictive models of the earthquake source.

  5. Modeling Dynamic Food Choice Processes to Understand Dietary Intervention Effects.

    Science.gov (United States)

    Marcum, Christopher Steven; Goldring, Megan R; McBride, Colleen M; Persky, Susan

    2018-02-17

    Meal construction is largely governed by nonconscious and habit-based processes that can be represented as a collection of in dividual, micro-level food choices that eventually give rise to a final plate. Despite this, dietary behavior intervention research rarely captures these micro-level food choice processes, instead measuring outcomes at aggregated levels. This is due in part to a dearth of analytic techniques to model these dynamic time-series events. The current article addresses this limitation by applying a generalization of the relational event framework to model micro-level food choice behavior following an educational intervention. Relational event modeling was used to model the food choices that 221 mothers made for their child following receipt of an information-based intervention. Participants were randomized to receive either (a) control information; (b) childhood obesity risk information; (c) childhood obesity risk information plus a personalized family history-based risk estimate for their child. Participants then made food choices for their child in a virtual reality-based food buffet simulation. Micro-level aspects of the built environment, such as the ordering of each food in the buffet, were influential. Other dynamic processes such as choice inertia also influenced food selection. Among participants receiving the strongest intervention condition, choice inertia decreased and the overall rate of food selection increased. Modeling food selection processes can elucidate the points at which interventions exert their influence. Researchers can leverage these findings to gain insight into nonconscious and uncontrollable aspects of food selection that influence dietary outcomes, which can ultimately improve the design of dietary interventions.

  6. Understanding Jordanian Psychiatric Nurses’ Smoking Behaviors: A Grounded Theory Study

    Directory of Open Access Journals (Sweden)

    Khaldoun M. Aldiabat

    2013-01-01

    Full Text Available Purpose. Smoking is prevalent in psychiatric facilities among staff and patients. However, there have been few studies of how contextual factors in specific cultures influence rates of smoking and the health promotion role of psychiatric nurses. This paper reports the findings of a classical grounded theory study conducted to understand how contextual factors in the workplace influences the smoking behaviors of Jordanian psychiatric nurses (JPNs. Method. Semi-structured individual interviews were conducted with a sample of eight male JPNs smokers at a psychiatric facility in Amman, Jordan. Findings. Constant comparative analysis identified becoming a heavy smoker as a psychosocial process characterized by four sub-categories: normalization of smoking; living in ambiguity; experiencing workplace conflict; and, facing up to workplace stressors. Conclusion. Specific contextual workplace factors require targeted smoking cessation interventions if JPNs are to receive the help they need to reduce health risks associated with heavy smoking.

  7. Dynamic behavior of concrete and seismic engineering

    National Research Council Canada - National Science Library

    Mazars, Jacky; Millard, Alain

    2009-01-01

    .... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.1.1. Meaning of the word "dynamic" . . . . . . . . . . . . . . . . . . . . . 1.1.2. Reminders about dynamic experimentation . . . . . . . . . . . . . . 1.1.3...

  8. Understanding the control of ingestive behavior in primates.

    Science.gov (United States)

    Wilson, Mark E; Moore, Carla J; Ethun, Kelly F; Johnson, Zachary P

    2014-06-01

    This article is part of a Special Issue "Energy Balance". Ingestive behavior in free-ranging populations of nonhuman primates is influenced by resource availability and social group organization and provides valuable insight on the evolution of ecologically adaptive behaviors and physiological systems. As captive populations were established, questions regarding proximate mechanisms that regulate food intake in these animals could be more easily addressed. The availability of these captive populations has led to the use of selected species to understand appetite control or metabolic physiology in humans. Recognizing the difficulty of quantitating food intake in free-ranging groups, the use of captive, singly-housed animals provided a distinct advantage though, at the same time, produced a different social ecology from the animals' natural habitat. However, the recent application of novel technologies to quantitate caloric intake and energy expenditure in free-feeding, socially housed monkeys permits prospective studies that can accurately define how food intake changes in response to any number of interventions in the context of a social environment. This review provides an overview of studies examining food intake using captive nonhuman primates organized into three areas: a) neurochemical regulation of food intake in nonhuman primates; b) whether exposure to specific diets during key developmental periods programs differences in diet preferences or changes the expression of feeding related neuropeptides; and c) how psychosocial factors influence appetite regulation. Because feeding patterns are driven by more than just satiety and orexigenic signals, appreciating how the social context influences pattern of feeding in nonhuman primates may be quite informative for understanding the biological complexity of feeding in humans. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Understanding and Predicting Human Behavior for Social Communities

    Science.gov (United States)

    Simoes, Jose; Magedanz, Thomas

    Over the last years, with the rapid advance in technology, it is becoming increasingly feasible for people to take advantage of the devices and services in the surrounding environment to remain "connected" and continuously enjoy the activity they are engaged in, be it sports, entertainment, or work. Such a ubiquitous computing environment will allow everyone permanent access to the Internet anytime, anywhere and anyhow [1]. Nevertheless, despite the evolution of services, social aspects remain in the roots of every human behavior and activities. Great examples of such phenomena are online social networks, which engage users in a way never seen before in the online world. At the same time, being aware and communicating context is a key part of human interaction and is a particularly powerful concept when applied to a community of users where services can be made more personalized and useful. Altogether, harvesting context to reason and learn about user behavior will further enhance the future multimedia vision where services can be composed and customized according to user context. Moreover, it will help us to understand users in a better way.

  10. Understanding recurrent crime as system-immanent collective behavior.

    Directory of Open Access Journals (Sweden)

    Matjaž Perc

    Full Text Available Containing the spreading of crime is a major challenge for society. Yet, since thousands of years, no effective strategy has been found to overcome crime. To the contrary, empirical evidence shows that crime is recurrent, a fact that is not captured well by rational choice theories of crime. According to these, strong enough punishment should prevent crime from happening. To gain a better understanding of the relationship between crime and punishment, we consider that the latter requires prior discovery of illicit behavior and study a spatial version of the inspection game. Simulations reveal the spontaneous emergence of cyclic dominance between "criminals", "inspectors", and "ordinary people" as a consequence of spatial interactions. Such cycles dominate the evolutionary process, in particular when the temptation to commit crime or the cost of inspection are low or moderate. Yet, there are also critical parameter values beyond which cycles cease to exist and the population is dominated either by a stable mixture of criminals and inspectors or one of these two strategies alone. Both continuous and discontinuous phase transitions to different final states are possible, indicating that successful strategies to contain crime can be very much counter-intuitive and complex. Our results demonstrate that spatial interactions are crucial for the evolutionary outcome of the inspection game, and they also reveal why criminal behavior is likely to be recurrent rather than evolving towards an equilibrium with monotonous parameter dependencies.

  11. Understanding catchment dynamics through a Space-Society-Water trialectic

    Science.gov (United States)

    Sutherland, Catherine; Jewitt, Graham; Risko, Susan; Hay, Ducan; Stuart-Hill, Sabine; Browne, Michelle

    2017-04-01

    Can healthy catchments be utilized to secure water for the benefit of society? This is a complex question as it requires an understanding of the connections and relations between biophysical, social, political, economic and governance dimensions over space and time in the catchment and must interrogate whether there is 'value' in investing in the catchment natural or ecological infrastructure (EI), how this should be done, where the most valuable EI is located, and whether an investment in EI will generate co-benefits socially, environmentally and economically. Here, we adopt a social ecological relations rather than systems approach to explore these interactions through development of a space-society-water trialectic. Trialectic thinking is challenging as it requires new epistemologies and it challenges conventional modes of thought. It is not ordered or fixed, but rather is constantly evolving, revealing the dynamic relations between the elements under exploration. The construction of knowledge, through detailed scientific research and social learning, which contributes to the understanding and achievement of sustainable water supply, water related resilient economic growth, greater social equity and justice in relation to water and the reduction of environmental risk is illustrated through research in the uMngeni Catchment, South Africa. Using four case studies as a basis, we construct the catchment level society-water-space trialectic as a way of connecting, assembling and comparing the understanding and knowledge that has been produced. The relations in the three elements of the trialectic are constructed through identifying, understanding and analysing the actors, discourses, knowledge, biophysical materialities, issues and spatial connections in the case studies. Together these relations, or multiple trajectories, are assembled to form the society-water-space trialectic, which illuminates the dominant relations in the catchment and hence reveal the leverage

  12. Understanding the HIV coreceptor switch from a dynamical perspective

    Directory of Open Access Journals (Sweden)

    Kamp Christel

    2009-11-01

    Full Text Available Abstract Background The entry of HIV into its target cells is facilitated by the prior binding to the cell surface molecule CD4 and a secondary coreceptor, mostly the chemokine receptors CCR5 or CXCR4. In early infection CCR5-using viruses (R5 viruses are mostly dominant while a receptor switch towards CXCR4 occurs in about 50% of the infected individuals (X4 viruses which is associated with a progression of the disease. There are many hypotheses regarding the underlying dynamics without yet a conclusive understanding. Results While it is difficult to isolate key factors in vivo we have developed a minimal in silico model based on the approaches of Nowak and May to investigate the conditions under which the receptor switch occurs. The model allows to investigate the evolution of viral strains within a probabilistic framework along the three stages of disease from primary and latent infection to the onset of AIDS with a a sudden increase in viral load which goes along with the impairment of the immune response. The model is specifically applied to investigate the evolution of the viral quasispecies in terms of R5 and X4 viruses which directly translates into the composition of viral load and consequently the question of the coreceptor switch. Conclusion The model can explain the coreceptor switch as a result of a dynamical change in the underlying environmental conditions in the host. The emergence of X4 strains does not necessarily result in the dominance of X4 viruses in viral load which is more likely to occur in the model after some time of chronic infection. A better understanding of the conditions leading to the coreceptor switch is especially of interest as CCR5 blockers have recently been licensed as drugs which suppress R5 viruses but do not seem to necessarily induce a coreceptor switch.

  13. Dynamic systems for everyone understanding how our world works

    CERN Document Server

    Ghosh, Asish

    2017-01-01

    Systems are everywhere and we are surrounded by them. We are a complex amalgam of systems that enable us to interact with an endless array of external systems in our daily lives. They are electrical, mechanical, social, biological, and many other types that control our environment and our well-being. By appreciating how these systems function, will broaden our understanding of how our world works. Readers from a variety of disciplines will benefit from the knowledge of system behavior they will gain from this book and will be able to apply those principles in various contexts. The treatment of the subject is non-mathematical, and the book considers some of the latest concepts in the systems discipline, such as agent based systems, optimization, and discrete events and procedures. The diverse range of examples provided in this book, will allow readers to: Apply system knowledge at work and in daily life without deep mathematical knowledge; Build models and simulate system behaviors on a personal computer; Opti...

  14. Dynamic systems for everyone understanding how our world works

    CERN Document Server

    Ghosh, Asish

    2015-01-01

    This book is a study of the interactions between different types of systems, their environment, and their subsystems.  The author explains how basic systems principles are applied in engineered (mechanical, electromechanical, etc.) systems and then guides the reader to understand how the same principles can be applied to social, political, economic systems, as well as in everyday life.  Readers from a variety of disciplines will benefit from the understanding of system behaviors and will be able to apply those principles in various contexts.  The book includes many examples covering various types of systems.  The treatment of the subject is non-mathematical, and the book considers some of the latest concepts in the systems discipline, such as agent-based systems, optimization, and discrete events and procedures.  ·         Shows how system knowledge may be applied in many different areas without the need for deep mathematical knowledge; ·         Demonstrates how to model and simulate s...

  15. A Learning-Style Theory for Understanding Autistic Behaviors

    Science.gov (United States)

    Qian, Ning; Lipkin, Richard M.

    2011-01-01

    Understanding autism's ever-expanding array of behaviors, from sensation to cognition, is a major challenge. We posit that autistic and typically developing brains implement different algorithms that are better suited to learn, represent, and process different tasks; consequently, they develop different interests and behaviors. Computationally, a continuum of algorithms exists, from lookup table (LUT) learning, which aims to store experiences precisely, to interpolation (INT) learning, which focuses on extracting underlying statistical structure (regularities) from experiences. We hypothesize that autistic and typical brains, respectively, are biased toward LUT and INT learning, in low- and high-dimensional feature spaces, possibly because of their narrow and broad tuning functions. The LUT style is good at learning relationships that are local, precise, rigid, and contain little regularity for generalization (e.g., the name–number association in a phonebook). However, it is poor at learning relationships that are context dependent, noisy, flexible, and do contain regularities for generalization (e.g., associations between gaze direction and intention, language and meaning, sensory input and interpretation, motor-control signal and movement, and social situation and proper response). The LUT style poorly compresses information, resulting in inefficiency, sensory overload (overwhelm), restricted interests, and resistance to change. It also leads to poor prediction and anticipation, frequent surprises and over-reaction (hyper-sensitivity), impaired attentional selection and switching, concreteness, strong local focus, weak adaptation, and superior and inferior performances on simple and complex tasks. The spectrum nature of autism can be explained by different degrees of LUT learning among different individuals, and in different systems of the same individual. Our theory suggests that therapy should focus on training autistic LUT algorithm to learn regularities

  16. A learning-style theory for understanding autistic behaviors

    Directory of Open Access Journals (Sweden)

    Ning eQian

    2011-08-01

    Full Text Available Understanding autism’s ever-expanding array of behaviors, from sensation to cognition, is a major challenge. We posit that autistic and typically-developing brains implement different algorithms that are better suited to learn, represent, and process different tasks; consequently, they develop different interests and behaviors. Computationally, a continuum of algorithms exists, from lookup-table (LUT learning, which aims to store experiences precisely, to interpolation (INT learning, which focuses on extracting underlying statistical structure (regularities from experiences. We hypothesize that autistic and typical brains, respectively, are biased toward LUT and INT learning, in low and high dimensional feature spaces, possibly because of their narrow and broad tuning functions. The LUT style is good at learning relationships that are local, precise, rigid, and contain little regularity for generalization (e.g., the name-number association in a phonebook. However, it is poor at learning relationships that are context dependent, noisy, flexible, and do contain regularities for generalization (e.g., associations between gaze direction and intention, language and meaning, sensory input and interpretation, motor-control signal and movement, and social situation and proper response. The LUT style poorly compresses information, resulting in inefficiency, sensory overload (overwhelm, restricted interests, and resistance to change. It also leads to poor prediction and anticipation, frequent surprises and over-reaction (hyper-sensitivity, impaired attentional selection and switching, concreteness, strong local focus, weak adaptation, and superior and inferior performances on simple and complex tasks. The spectrum nature of autism can be explained by different degrees of LUT learning among different individuals, and in different systems of the same individual. Our theory suggests that therapy should focus on training autistic LUT algorithm to learn

  17. The role of complex networks in behavior epidemiology. Comment on "Coupled disease-behavior dynamics on complex networks: A review" by Z. Wang et al.

    Science.gov (United States)

    Zhao, Dawei; Wang, Lianhai

    2015-12-01

    Outbreaks of disease can trigger spontaneous behavioral response of individuals to consider prevention measures (mainly including medical cure and non-pharmaceutical intervention), which usually in turn influence the diffusion of epidemic, namely, forming the interplay between individual behaviors and epidemic dynamics. During the past decade, understanding such coupled disease-behavior dynamics in population has become a critical tool for predicting the disease evolution and designing effective prevention strategies [1-3].

  18. A Contextual Behavior Science Framework for Understanding How Behavioral Flexibility Relates to Anxiety.

    Science.gov (United States)

    Palm Reed, Kathleen M; Cameron, Amy Y; Ameral, Victoria E

    2017-09-01

    There is a growing literature focusing on the emerging idea that behavioral flexibility, rather than particular emotion regulation strategies per se, provides greater promise in predicting and influencing anxiety-related psychopathology. Yet this line of research and theoretical analysis appear to be plagued by its own challenges. For example, middle-level constructs, such as behavioral flexibility, are difficult to define, difficult to measure, and difficult to interpret in relation to clinical interventions. A key point that some researchers have made is that previous studies examining flexible use of emotion regulation strategies (or, more broadly, coping) have failed due to a lack of focus on context. That is, examining strategies in isolation of the context in which they are used provides limited information on the suitability, rigid adherence, or effectiveness of a given strategy in that situation. Several of these researchers have proposed the development of new models to define and measure various types of behavioral flexibility. We would like to suggest that an explanation of the phenomenon already exists and that we can go back to our behavioral roots to understand this phenomenon rather than focusing on defining and capturing a new process. Indeed, thorough contextual behavioral analyses already yield a useful account of what has been observed. We will articulate a model explaining behavioral flexibility using a functional, contextual framework, with anxiety-related disorders as an example.

  19. Understanding Social Learning Behaviors via a Virtual Field Trip

    Directory of Open Access Journals (Sweden)

    Xin Bai

    2014-06-01

    Full Text Available This is a multidisciplinary study investigating how a virtual rather than face-to-face field trip can be conducted in a real-world setting and how students respond to such a social learning opportunity. Our participants followed a story of a stroke patient at her virtual home and in a virtual hospital via a teaching vignette. They were then given a new case and got on a virtual trip via a multiuser virtual environment. They played the roles of patients, relatives, doctors, or nurses, experiencing the emotional, physical, or social impacts those stakeholders may go through. Our study finds the overall participation of the Virtual Group is 50% more than the Text Group. Although the Virtual Group generates much more nodes in total, they focused much less on knowledge sharing and comparing than the Text Group (46 vs. 67, but more on other higher-level aspects of social interactions, such as knowledge discovery (57 vs. 42, co-construction (66 vs. 39, testing and modification (58 vs. 24 and application of newly constructed meaning (60 vs. 16. Analysis of students’ virtual field activities and in-depth discussions of important issues implied are included to help understand social learning behaviors during a virtual field trip. Sustainability of such systems is discussed.

  20. A dynamical system perspective to understanding badminton singles game play.

    Science.gov (United States)

    Chow, Jia Yi; Seifert, Ludovic; Hérault, Romain; Chia, Shannon Jing Yi; Lee, Miriam Chang Yi

    2014-02-01

    By altering the task constraints of cooperative and competitive game contexts in badminton, insights can be obtained from a dynamical systems perspective to investigate the underlying processes that results in either a gradual shift or transition of playing patterns. Positional data of three pairs of skilled female badminton players (average age 20.5±1.38years) were captured and analyzed. Local correlation coefficient, which provides information on the relationship of players' displacement data, between each pair of players was computed for angle and distance from base position. Speed scalar product was in turn established from speed vectors of the players. The results revealed two patterns of playing behaviors (i.e., in-phase and anti-phase patterns) for movement displacement. Anti-phase relation was the dominant coupling pattern for speed scalar relationships among the pairs of players. Speed scalar product, as a collective variable, was different between cooperative and competitive plays with a greater variability in amplitude seen in competitive plays leading to a winning point. The findings from this study provide evidence for increasing stroke variability to perturb existing stable patterns of play and highlights the potential for speed scalar product to be a collective variable to distinguish different patterns of play (e.g., cooperative and competitive). Copyright © 2013 Elsevier B.V. All rights reserved.

  1. A quantitative evolutionary theory of adaptive behavior dynamics.

    Science.gov (United States)

    McDowell, J J

    2013-10-01

    The idea that behavior is selected by its consequences in a process analogous to organic evolution has been discussed for over 100 years. A recently proposed theory instantiates this idea by means of a genetic algorithm that operates on a population of potential behaviors. Behaviors in the population are represented by numbers in decimal integer (phenotypic) and binary bit string (genotypic) forms. One behavior from the population is emitted at random each time tick, after which a new population of potential behaviors is constructed by recombining parent behavior bit strings. If the emitted behavior produced a benefit to the organism, then parents are chosen on the basis of their phenotypic similarity to the emitted behavior; otherwise, they are chosen at random. After parent behavior recombination, the population is subjected to a small amount of mutation by flipping random bits in the population's bit strings. The behavior generated by this process of selection, reproduction, and mutation reaches equilibrium states that conform to every empirically valid equation of matching theory, exactly and without systematic error. These equations are known to describe the behavior of many vertebrate species, including humans, in a variety of experimental, naturalistic, natural, and social environments. The evolutionary theory also generates instantaneous dynamics and patterns of preference change in constantly changing environments that are consistent with the dynamics of live-organism behavior. These findings support the assertion that the world of behavior we observe and measure is generated by evolutionary dynamics. PsycINFO Database Record (c) 2013 APA, all rights reserved

  2. AIDS, behavior, and culture: understanding evidence-based prevention

    National Research Council Canada - National Science Library

    Green, Edward C; Ruark, Allison Herling

    2011-01-01

    .... Arguing for a behavior-based approach, the authors make the case that the most effective programs are those that encourage fundamental behavioral changes such as faithfulness, avoidance of concurrent...

  3. Cycle length restitution in sinoatrial node cells: a theory for understanding spontaneous action potential dynamics.

    Directory of Open Access Journals (Sweden)

    Patric Glynn

    Full Text Available Normal heart rhythm (sinus rhythm is governed by the sinoatrial node, a specialized and highly heterogeneous collection of spontaneously active myocytes in the right atrium. Sinoatrial node dysfunction, characterized by slow and/or asynchronous pacemaker activity and even failure, is associated with cardiovascular disease (e.g. heart failure, atrial fibrillation. While tremendous progress has been made in understanding the molecular and ionic basis of automaticity in sinoatrial node cells, the dynamics governing sinoatrial nodel cell synchrony and overall pacemaker function remain unclear. Here, a well-validated computational model of the mouse sinoatrial node cell is used to test the hypothesis that sinoatrial node cell dynamics reflect an inherent restitution property (cycle length restitution that may give rise to a wide range of behavior from regular periodicity to highly complex, irregular activation. Computer simulations are performed to determine the cycle length restitution curve in the computational model using a newly defined voltage pulse protocol. The ability of the restitution curve to predict sinoatrial node cell dynamics (e.g., the emergence of irregular spontaneous activity and susceptibility to termination is evaluated. Finally, ionic and tissue level factors (e.g. ion channel conductances, ion concentrations, cell-to-cell coupling that influence restitution and sinoatrial node cell dynamics are explored. Together, these findings suggest that cycle length restitution may be a useful tool for analyzing cell dynamics and dysfunction in the sinoatrial node.

  4. Quality Improvement in Hospitals: Identifying and Understanding Behaviors

    Directory of Open Access Journals (Sweden)

    Lukasz M. Mazur

    2012-01-01

    Full Text Available Improving operational performance in hospitals is complicated, particularly if process improvement requires complex behavioral changes. Using single-loop and double-loop learning theory as a foundation, the purpose of this research is to empirically uncover key improvement behaviors and the factors that may be associated with such behaviors in hospitals. A two-phased approach was taken to collect data regarding improvement behaviors and associated factors, and data analysis was conducted using methods proposed by grounded theorists. The contributions of this research are twofold. First, five key behaviors related to process improvement are identified, namely Quick Fixing, Initiating, Conforming, Expediting, and Enhancing. Second, based on these observed behaviors, a set of force field diagrams is developed to structure and organize possible factors that are important to consider when attempting to change improvement behaviors. This begins to fill the gap in the knowledge about what factors drive effective improvement efforts in hospital settings.

  5. The Contribution of GGOS to Understanding Dynamic Earth Processes

    Science.gov (United States)

    Gross, Richard

    2017-04-01

    Geodesy is the science of the Earth's shape, size, gravity and rotation, including their evolution in time. Geodetic observations play a major role in the solid Earth sciences because they are fundamental for the understanding and modeling of Earth system processes. Changes in the Earth's shape, its gravitational field, and its rotation are caused by external forces acting on the Earth system and internal processes involving mass transfer and exchange of angular and linear momentum. Thus, variations in these geodetic quantities of the Earth reflect and constrain mechanical and thermo-dynamic processes in the Earth system. Mitigating the impact on human life and property of natural hazards such as earthquakes, volcanic eruptions, debris flows, landslides, land subsidence, sea level change, tsunamis, floods, storm surges, hurricanes and extreme weather is an important scientific task to which geodetic observations make fundamental contributions. Geodetic observations can be used to monitor the pre-eruptive deformation of volcanoes and the pre-seismic deformation of earthquake fault zones, aiding in the issuance of volcanic eruption and earthquake warnings. They can also be used to rapidly estimate earthquake fault motion, aiding in the modeling of tsunami genesis and the issuance of tsunami warnings. Geodetic observations are also used in other areas of the Earth sciences, not just the solid Earth sciences. For example, geodesy contributes to atmospheric science by supporting both observation and prediction of the weather by geo-referencing meteorological observing data and by globally tracking change in stratospheric mass and lower tropospheric water vapor fields. Geodetic measurements of refraction profiles derived from satellite occultation data are routinely assimilated into numerical weather prediction models. Geodesy contributes to hydrologic studies by providing a unique global reference system for measurements of: sub-seasonal, seasonal and secular movements

  6. Understanding quantum measurement from the solution of dynamical models

    International Nuclear Information System (INIS)

    Allahverdyan, Armen E.; Balian, Roger; Nieuwenhuizen, Theo M.

    2013-01-01

    The quantum measurement problem, to wit, understanding why a unique outcome is obtained in each individual experiment, is currently tackled by solving models. After an introduction we review the many dynamical models proposed over the years for elucidating quantum measurements. The approaches range from standard quantum theory, relying for instance on quantum statistical mechanics or on decoherence, to quantum–classical methods, to consistent histories and to modifications of the theory. Next, a flexible and rather realistic quantum model is introduced, describing the measurement of the z-component of a spin through interaction with a magnetic memory simulated by a Curie–Weiss magnet, including N≫1 spins weakly coupled to a phonon bath. Initially prepared in a metastable paramagnetic state, it may transit to its up or down ferromagnetic state, triggered by its coupling with the tested spin, so that its magnetization acts as a pointer. A detailed solution of the dynamical equations is worked out, exhibiting several time scales. Conditions on the parameters of the model are found, which ensure that the process satisfies all the features of ideal measurements. Various imperfections of the measurement are discussed, as well as attempts of incompatible measurements. The first steps consist in the solution of the Hamiltonian dynamics for the spin-apparatus density matrix D -hat (t). Its off-diagonal blocks in a basis selected by the spin–pointer coupling, rapidly decay owing to the many degrees of freedom of the pointer. Recurrences are ruled out either by some randomness of that coupling, or by the interaction with the bath. On a longer time scale, the trend towards equilibrium of the magnet produces a final state D -hat (t f ) that involves correlations between the system and the indications of the pointer, thus ensuring registration. Although D -hat (t f ) has the form expected for ideal measurements, it only describes a large set of runs. Individual runs are

  7. Understanding quantum measurement from the solution of dynamical models

    Energy Technology Data Exchange (ETDEWEB)

    Allahverdyan, Armen E. [Laboratoire de Physique Statistique et Systèmes Complexes, ISMANS, 44 Av. Bartholdi, 72000 Le Mans (France); Balian, Roger [Institut de Physique Théorique, CEA Saclay, 91191 Gif-sur-Yvette cedex (France); Nieuwenhuizen, Theo M., E-mail: T.M.Nieuwenhuizen@uva.nl [Center for Cosmology and Particle Physics, New York University, 4 Washington Place, New York, NY 10003 (United States)

    2013-04-15

    The quantum measurement problem, to wit, understanding why a unique outcome is obtained in each individual experiment, is currently tackled by solving models. After an introduction we review the many dynamical models proposed over the years for elucidating quantum measurements. The approaches range from standard quantum theory, relying for instance on quantum statistical mechanics or on decoherence, to quantum–classical methods, to consistent histories and to modifications of the theory. Next, a flexible and rather realistic quantum model is introduced, describing the measurement of the z-component of a spin through interaction with a magnetic memory simulated by a Curie–Weiss magnet, including N≫1 spins weakly coupled to a phonon bath. Initially prepared in a metastable paramagnetic state, it may transit to its up or down ferromagnetic state, triggered by its coupling with the tested spin, so that its magnetization acts as a pointer. A detailed solution of the dynamical equations is worked out, exhibiting several time scales. Conditions on the parameters of the model are found, which ensure that the process satisfies all the features of ideal measurements. Various imperfections of the measurement are discussed, as well as attempts of incompatible measurements. The first steps consist in the solution of the Hamiltonian dynamics for the spin-apparatus density matrix D{sup -hat} (t). Its off-diagonal blocks in a basis selected by the spin–pointer coupling, rapidly decay owing to the many degrees of freedom of the pointer. Recurrences are ruled out either by some randomness of that coupling, or by the interaction with the bath. On a longer time scale, the trend towards equilibrium of the magnet produces a final state D{sup -hat} (t{sub f}) that involves correlations between the system and the indications of the pointer, thus ensuring registration. Although D{sup -hat} (t{sub f}) has the form expected for ideal measurements, it only describes a large set of

  8. Assessing Freshman Engineering Students' Understanding of Ethical Behavior.

    Science.gov (United States)

    Henslee, Amber M; Murray, Susan L; Olbricht, Gayla R; Ludlow, Douglas K; Hays, Malcolm E; Nelson, Hannah M

    2017-02-01

    Academic dishonesty, including cheating and plagiarism, is on the rise in colleges, particularly among engineering students. While students decide to engage in these behaviors for many different reasons, academic integrity training can help improve their understanding of ethical decision making. The two studies outlined in this paper assess the effectiveness of an online module in increasing academic integrity among first semester engineering students. Study 1 tested the effectiveness of an academic honesty tutorial by using a between groups design with a Time 1- and Time 2-test. An academic honesty quiz assessed participants' knowledge at both time points. Study 2, which incorporated an improved version of the module and quiz, utilized a between groups design with three assessment time points. The additional Time 3-test allowed researchers to test for retention of information. Results were analyzed using ANCOVA and t tests. In Study 1, the experimental group exhibited significant improvement on the plagiarism items, but not the total score. However, at Time 2 there was no significant difference between groups after controlling for Time 1 scores. In Study 2, between- and within-group analyses suggest there was a significant improvement in total scores, but not plagiarism scores, after exposure to the tutorial. Overall, the academic integrity module impacted participants as evidenced by changes in total score and on specific plagiarism items. Although future implementation of the tutorial and quiz would benefit from modifications to reduce ceiling effects and improve assessment of knowledge, the results suggest such tutorial may be one valuable element in a systems approach to improving the academic integrity of engineering students.

  9. Understanding the dynamics of water availability and use in China

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, R.P.; Conrad, S.H.; Jeppesen, D.M.; Engi, E.

    1997-07-01

    This report presents the preliminary results of an analysis of China`s water resources, part of an effort undertaken by the National Intelligence Council Medea scientists to improve the understanding of future food production and consumption in the People`s Republic of China. A dynamic water model was developed to simulate the hydrological budgetary processes in five river drainage basins located in northeastern, central, and southern China: the Chang Jiang (Yangtse River), Huanghe (Yellow River), Haihe, Huaihe, and Liaohe. The model was designed to assess the effects of changes in urban, industrial, and agricultural water use requirements on the availability of water in each basin and to develop estimates of the water surpluses and/or deficits in China through the year 2025. The model imposes a sustainable yield constraint, that is, groundwater extraction is not allowed to exceed the sustainable yield; if the available water does not meet the total water use requirements, a deficit results. An agronomic model was also developed to generate projections of the water required to service China`s agricultural sector and compare China`s projected grain production with projected grain consumption requirements to estimate any grain surplus and/or deficit. In future refinements, the agronomic model will interface directly with the water model to provide for the exchange of information on projected water use requirements and available water. The preliminary results indicate that the Chang Jiang basin will have a substantial surplus of water through 2025 and that the Haihe basin is in an ongoing situation. The agricultural water use requirements based on grain production indicate that an agricultural water deficit in the Haihe basin begins before the onset of the modeling period (1980) and steadily worsens through 2025. This assumption is confirmed by reports that groundwater mining is already under way in the most intensely cultivated and populated areas of northern China.

  10. Understanding dynamic changes in live cell adhesion with neutron reflectometry

    Science.gov (United States)

    Junghans, Ann

    Understanding the structure and functionality of biological systems on a nanometer-resolution and short temporal scales is important for solving complex biological problems, developing innovative treatment, and advancing the design of highly functionalized biomimetic materials. For example, adhesion of cells to an underlying substrate plays a crucial role in physiology and disease development, and has been investigated with great interest for several decades. In the talk, we would like to highlight recent advances in utilizing neutron scattering to study bio-related structures in dynamic conditions (e . g . under the shear flow) including in-situ investigations of the interfacial properties of living cells. The strength of neutron reflectometry is its non-pertubative nature, the ability to probe buried interfaces with nanometer resolution and its sensitivity to light elements like hydrogen and carbon. That allows us to study details of cell - substrate interfaces that are not accessible with any other standard techniques. We studied the adhesion of human brain tumor cells (U251) to quartz substrates and their responses to the external mechanical forces. Such cells are isolated within the central nervous system which makes them difficult to reach with conventional therapies and therefore making them highly invasive. Our results reveal changes in the thickness and composition of the adhesion layer (a layer between the cell lipid membrane and the quartz substrate), largely composed of hyaluronic acid and associated proteoglycans, when the cells were subjected to shear stress. Further studies will allow us to determine more conditions triggering changes in the composition of the bio-material in the adhesion layer. This, in turn, can help to identify changes that correlate with tumor invasiveness, which can have significant medical impact for the development of targeted anti-invasive therapies.

  11. Modulating mimicry: Exploring the roles of inhibitory control and social understanding in 5-year-olds' behavioral mimicry.

    Science.gov (United States)

    van Schaik, Johanna E; Hunnius, Sabine

    2018-01-01

    During adult interactions, behavioral mimicry, the implicit copying of an interaction partner's postures and mannerisms, communicates liking and affiliation. While this social behavior likely develops during early childhood, it is unclear which factors contribute to its emergence. Here, the roles of inhibitory control and social understanding on 5-year-olds' behavioral mimicry were investigated. Following a social manipulation in which one experimenter shared a sticker with the child and the other experimenter kept two stickers for herself, children watched a video in which these experimenters each told a story. During this story session, children in the experimental group (n = 28) observed the experimenters perform face and hand rubbing behaviors whereas the control group (n = 23) did not see these behaviors. Children's inhibitory control was assessed using the day-night task and their social understanding was measured through a parental questionnaire. Surprisingly, group-level analyses revealed that the experimental group performed the behaviors significantly less than the control group (i.e. a negative mimicry effect) for both the sticker-sharer and sticker-keeper. Yet, the hypothesized effects of inhibitory control and social understanding were found. Inhibitory control predicted children's selective mimicry of the sticker-keeper versus sticker-sharer and children's overall mimicry was correlated with social understanding. These results provide the first indications to suggest that factors of social and cognitive development dynamically influence the emergence and specificity of behavioral mimicry during early childhood.

  12. A Refined Numerical Simulation on Dynamic Behavior of Roller Chain Drives

    Directory of Open Access Journals (Sweden)

    H. Zheng

    2004-01-01

    Full Text Available A refined numerical analysis of the dynamic behavior of roller chain drives is performed considering the roller assembly as a three-layer structure with mechanical clearance between each two of the mechanical components. Instead of using analytical method, explicit finite element technique is utilized for modeling and simulating the dynamic behavior of chain drives. The complete standard geometry of sprockets and all components of chain links are used in the developed model with minor geometry simplification. A primary goal is to achieve a more complete understanding of the dynamic behavior of chain drives especially in the transient vibration response of the engaging rollers, which is crucial for noise emission calculation. The simulated velocity response of the engaging rollers and roller-sprocket contact forces achieved using the full model are compared with what found by the simple model which has been adopted in analytical study of chain roller dynamics.

  13. "I Got Your Back": Friends' Understandings regarding College Student Spring Break Behavior

    Science.gov (United States)

    Patrick, Megan E.; Morgan, Nicole; Maggs, Jennifer L.; Lefkowitz, Eva S.

    2011-01-01

    Behaviors that pose threats to safety and health, including binge drinking and unprotected sex, increase during a week-long break from university. Understandings with peers regarding these behaviors may be important for predicting behavior and related harms. College students (N = 651; 48% men) reported having understandings with their friends…

  14. Guest Editors’ Introduction On Understanding Ethical Behavior and Decision Making

    NARCIS (Netherlands)

    D. de Cremer (David); D.M. Mayer (David); M. Schminke (Marshall)

    2010-01-01

    textabstractBehavioral ethics is an emerging field that takes an empirical, social scientific approach to the study of business ethics. In this special issue, we include six articles that fall within the domain of behavioral ethics and that focus on three themes—moral awareness, ethical decision

  15. Understanding User Behavioral Patterns in Open Knowledge Communities

    Science.gov (United States)

    Yang, Xianmin; Song, Shuqiang; Zhao, Xinshuo; Yu, Shengquan

    2018-01-01

    Open knowledge communities (OKCs) have become popular in the era of knowledge economy. This study aimed to explore how users collaboratively create and share knowledge in OKCs. In particular, this research identified the behavior distribution and behavioral patterns of users by conducting frequency distribution and lag sequential analyses. Some…

  16. Behavior of Brittle Materials Under Dynamic Loading

    National Research Council Canada - National Science Library

    Kanel, G

    2000-01-01

    Dynamic loading of brittle materials is related to many applications, including explosive excavation of rocks, design of ceramic armor, meteor impact on spacecraft windows, particle damage to turbine blades, etc...

  17. Complex Dynamic Behavior in Simple Gene Regulatory Networks

    Science.gov (United States)

    Santillán Zerón, Moisés

    2007-02-01

    Knowing the complete genome of a given species is just a piece of the puzzle. To fully unveil the systems behavior of an organism, an organ, or even a single cell, we need to understand the underlying gene regulatory dynamics. Given the complexity of the whole system, the ultimate goal is unattainable for the moment. But perhaps, by analyzing the most simple genetic systems, we may be able to develop the mathematical techniques and procedures required to tackle more complex genetic networks in the near future. In the present work, the techniques for developing mathematical models of simple bacterial gene networks, like the tryptophan and lactose operons are introduced. Despite all of the underlying assumptions, such models can provide valuable information regarding gene regulation dynamics. Here, we pay special attention to robustness as an emergent property. These notes are organized as follows. In the first section, the long historical relation between mathematics, physics, and biology is briefly reviewed. Recently, the multidisciplinary work in biology has received great attention in the form of systems biology. The main concepts of this novel science are discussed in the second section. A very slim introduction to the essential concepts of molecular biology is given in the third section. In the fourth section, a brief introduction to chemical kinetics is presented. Finally, in the fifth section, a mathematical model for the lactose operon is developed and analyzed..

  18. Thermomechanical behavior of EUV pellicle under dynamic exposure conditions

    Science.gov (United States)

    Goldfarb, Dario L.; Bloomfield, Max O.; Colburn, Matthew

    2016-03-01

    The utilization of EUV pellicles as protective layers for EUV masks requires the use of refractory materials that can tolerate large temperature excursions due to the non-negligible absorption of EUV radiation during exposure. Additionally, the mechanical stress induced on the EUV pellicle by the thermal load is dependent on the thermal expansion of the material which can be responsible for transient wrinkling. In this study, an ultrathin (20 nm), free-standing membrane based on silicon nitride is utilized as a learning vehicle to understand the material requirements of EUV pellicles under dynamic exposure conditions that are typical of commercial EUV scanners. First, the nanoscale radiative properties (emissivity) and thermo-mechanical failure temperature of the dielectric film under vacuum conditions are experimentally investigated utilizing a pulsed ArF (193 nm) probing laser. The silicon nitride membrane is found to be marginally compatible with an equivalent 80W EUV source power under steady state illumination conditions. Next, the thermal behavior of the EUV pellicle under dynamic exposure conditions is simulated using a finite element solver. The transient temperature profile and stress distribution across the membrane under stationary state conditions are extracted for an equivalent 60W EUV power source and the pellicle wrinkling due to heating and consequent impact on CD uniformity is estimated. The present work provides a generalized methodology to anticipate the thermal response of a EUV pellicle under realistic exposure conditions.

  19. Dynamic behavior of semivolatile organic compounds in indoor air

    Energy Technology Data Exchange (ETDEWEB)

    Loy, Michael David Van [Univ. of California, Berkeley, CA (United States)

    1998-12-09

    Exposures to a wide range of air pollutants are often dominated by those occurring in buildings because of three factors: 1) most people spend a large fraction of their time indoors, 2) many pollutants have strong indoor sources, and 3) the dilution volume in buildings is generally several orders of magnitude smaller than that of an urban airshed. Semivolatile organic compounds (SVOCS) are emitted by numerous indoor sources, including tobacco combustion, cooking, carpets, paints, resins, and glues, so indoor gasphase concentrations of these compounds are likely to be elevated relative to ambient levels. The rates of uptake and release of reversibly sorbing SVOCS by indoor materials directly affect both peak concentrations and persistence of the pollutants indoors after source elimination. Thus, accurate predictions of SVOC dynamics in indoor air require an understanding of contaminant sorption on surface materials such as carpet and wallboard. The dynamic behaviors of gas-phase nicotine and phenanthrene were investigated in a 20 ms stainless steel chamber containing carpet and painted wallboard. Each compound was studied independently, first in the empty chamber, then with each sorbent individually, and finally with both sorbents in the chamber.

  20. Global brain dynamics during social exclusion predict subsequent behavioral conformity

    Science.gov (United States)

    Wasylyshyn, Nick; Hemenway Falk, Brett; Garcia, Javier O; Cascio, Christopher N; O’Donnell, Matthew Brook; Bingham, C Raymond; Simons-Morton, Bruce; Vettel, Jean M; Falk, Emily B

    2018-01-01

    Abstract Individuals react differently to social experiences; for example, people who are more sensitive to negative social experiences, such as being excluded, may be more likely to adapt their behavior to fit in with others. We examined whether functional brain connectivity during social exclusion in the fMRI scanner can be used to predict subsequent conformity to peer norms. Adolescent males (n = 57) completed a two-part study on teen driving risk: a social exclusion task (Cyberball) during an fMRI session and a subsequent driving simulator session in which they drove alone and in the presence of a peer who expressed risk-averse or risk-accepting driving norms. We computed the difference in functional connectivity between social exclusion and social inclusion from each node in the brain to nodes in two brain networks, one previously associated with mentalizing (medial prefrontal cortex, temporoparietal junction, precuneus, temporal poles) and another with social pain (dorsal anterior cingulate cortex, anterior insula). Using predictive modeling, this measure of global connectivity during exclusion predicted the extent of conformity to peer pressure during driving in the subsequent experimental session. These findings extend our understanding of how global neural dynamics guide social behavior, revealing functional network activity that captures individual differences. PMID:29529310

  1. Global brain dynamics during social exclusion predict subsequent behavioral conformity.

    Science.gov (United States)

    Wasylyshyn, Nick; Hemenway Falk, Brett; Garcia, Javier O; Cascio, Christopher N; O'Donnell, Matthew Brook; Bingham, C Raymond; Simons-Morton, Bruce; Vettel, Jean M; Falk, Emily B

    2018-02-01

    Individuals react differently to social experiences; for example, people who are more sensitive to negative social experiences, such as being excluded, may be more likely to adapt their behavior to fit in with others. We examined whether functional brain connectivity during social exclusion in the fMRI scanner can be used to predict subsequent conformity to peer norms. Adolescent males (n = 57) completed a two-part study on teen driving risk: a social exclusion task (Cyberball) during an fMRI session and a subsequent driving simulator session in which they drove alone and in the presence of a peer who expressed risk-averse or risk-accepting driving norms. We computed the difference in functional connectivity between social exclusion and social inclusion from each node in the brain to nodes in two brain networks, one previously associated with mentalizing (medial prefrontal cortex, temporoparietal junction, precuneus, temporal poles) and another with social pain (dorsal anterior cingulate cortex, anterior insula). Using predictive modeling, this measure of global connectivity during exclusion predicted the extent of conformity to peer pressure during driving in the subsequent experimental session. These findings extend our understanding of how global neural dynamics guide social behavior, revealing functional network activity that captures individual differences.

  2. Dynamic behavior of chemical reactivity indices in density functional ...

    Indian Academy of Sciences (India)

    Dynamic behaviors of chemical concepts in density functional theory such as frontier orbitals (HOMO/LUMO), chemical potential, hardness, and electrophilicity index have been investigated in this work in the context of Bohn-Oppenheimer quantum molecular dynamics in association with molecular conformation changes.

  3. A dynamic-logical perspective on quantum behavior

    NARCIS (Netherlands)

    Baltag, A.; Smets, S.

    2008-01-01

    In this paper we show how recent concepts from Dynamic Logic, and in particular from Dynamic Epistemic logic, can be used to model and interpret quantum behavior. Our main thesis is that all the non-classical properties of quantum systems are explainable in terms of the non-classical flow of quantum

  4. Effects of Structural Transparency in System Dynamics Simulators on Performance and Understanding

    Directory of Open Access Journals (Sweden)

    Birgit Kopainsky

    2015-10-01

    Full Text Available Prior exploration is an instructional strategy that has improved performance and understanding in system-dynamics-based simulators, but only to a limited degree. This study investigates whether model transparency, that is, showing users the internal structure of models, can extend the prior exploration strategy and improve learning even more. In an experimental study, participants in a web-based simulation learned about and managed a small developing nation. All participants were provided the prior exploration strategy but only half received prior exploration embedded in a structure-behavior diagram intended to make the underlying model’s structure more transparent. Participants provided with the more transparent strategy demonstrated better understanding of the underlying model. Their performance, however, was the equivalent to those in the less transparent condition. Combined with previous studies, our results suggest that while prior exploration is a beneficial strategy for both performance and understanding, making the model structure transparent with structure-behavior diagrams is more limited in its effect.

  5. Dynamic behavior of multirobot systems using lattice gas automata

    Science.gov (United States)

    Stantz, Keith M.; Cameron, Stewart M.; Robinett, Rush D., III; Trahan, Michael W.; Wagner, John S.

    1999-07-01

    Recent attention has been given to the deployment of an adaptable sensor array realized by multi-robotic systems (or swarms). Our group has been studying the collective, autonomous behavior of these such systems and their applications in the area of remote-sensing and emerging threats. To accomplish such tasks, an interdisciplinary research effort at Sandia National Laboratories are conducting tests in the fields of sensor technology, robotics, and multi- agents architectures. Our goal is to coordinate a constellation of point sensors using unmanned robotic vehicles (e.g., RATLERs, Robotic All-Terrain Lunar Exploration Rover- class vehicles) that optimizes spatial coverage and multivariate signal analysis. An overall design methodology evolves complex collective behaviors realized through local interaction (kinetic) physics and artificial intelligence. Learning objectives incorporate real-time operational responses to environmental changes. This paper focuses on our recent work understanding the dynamics of many-body systems according to the physics-based hydrodynamic model of lattice gas automata. Three design features are investigated. One, for single-speed robots, a hexagonal nearest-neighbor interaction topology is necessary to preserve standard hydrodynamic flow. Two, adaptability, defined by the swarm's rate of deformation, can be controlled through the hydrodynamic viscosity term, which, in turn, is defined by the local robotic interaction rules. Three, due to the inherent nonlinearity of the dynamical equations describing large ensembles, stability criteria ensuring convergence to equilibrium states is developed by scaling information flow rates relative to a swarm's hydrodynamic flow rate. An initial test case simulates a swarm of twenty-five robots maneuvering past an obstacle while following a moving target. A genetic algorithm optimizes applied nearest-neighbor forces in each of five spatial regions distributed over the simulation domain. Armed with

  6. Understanding HIV Risk Behavior among Tuberculosis Patients with Alcohol Use Disorders in Tomsk, Russian Federation.

    Science.gov (United States)

    Miller, Ann C; Nelson, A Katrina; Livchits, Viktoria; Greenfield, Shelly F; Yanova, Galina; Yanov, Sergei; Connery, Hilary S; Atwood, Sidney; Lastimoso, Charmaine S; Shin, Sonya S

    2016-01-01

    Russian Federation's (RF) HIV epidemic is the fastest growing of any country. This study explores factors associated with high HIV risk behavior in tuberculosis (TB) patients with alcohol use disorders in Tomsk, RF. This analysis was nested within the Integrated Management of Physician-delivered Alcohol Care for TB Patients (IMPACT, trial number NCT00675961) randomized controlled study of integrating alcohol treatment into TB treatment in Tomsk. Demographics, HIV risk behavior (defined as participant report of high-risk intravenous drug use and/or multiple sexual partners with inconsistent condom use in the last six months), clinical data, alcohol use, depression and psychosocial factors were collected from 196 participants (161 male and 35 female) at baseline. Forty-six participants (23.5%) endorsed HIV risk behavior at baseline. Incarceration history(Odds Ratio (OR)3.93, 95% confidence interval (CI) 1.95, 7.95), age under 41 (OR:2.97, CI:1.46, 6.04), drug addiction(OR: 3.60 CI:1.10, 11.77), history of a sexually transmitted disease(STD)(OR 2.00 CI:1.02, 3.90), low social capital (OR:2.81 CI:0.99, 8.03) and heavier alcohol use (OR:2.56 CI: 1.02, 6.46) were significantly more likely to be associated with HIV risk behavior at baseline. In adjusted analysis, age under 41(OR: 4.93, CI: 2.10, 11.58), incarceration history(OR: 3.56 CI:1.55, 8.17) and STD history (OR: 3.48, CI: 1.5, 8.10) continued to be significantly associated with HIV risk behavior. Understanding HIV transmission dynamics in Russia remains an urgent priority to inform strategies to address the epidemic. Larger studies addressing sex differences in risks and barriers to protective behavior are needed.

  7. Understanding HIV Risk Behavior among Tuberculosis Patients with Alcohol Use Disorders in Tomsk, Russian Federation.

    Directory of Open Access Journals (Sweden)

    Ann C Miller

    Full Text Available Russian Federation's (RF HIV epidemic is the fastest growing of any country. This study explores factors associated with high HIV risk behavior in tuberculosis (TB patients with alcohol use disorders in Tomsk, RF. This analysis was nested within the Integrated Management of Physician-delivered Alcohol Care for TB Patients (IMPACT, trial number NCT00675961 randomized controlled study of integrating alcohol treatment into TB treatment in Tomsk. Demographics, HIV risk behavior (defined as participant report of high-risk intravenous drug use and/or multiple sexual partners with inconsistent condom use in the last six months, clinical data, alcohol use, depression and psychosocial factors were collected from 196 participants (161 male and 35 female at baseline. Forty-six participants (23.5% endorsed HIV risk behavior at baseline. Incarceration history(Odds Ratio (OR3.93, 95% confidence interval (CI 1.95, 7.95, age under 41 (OR:2.97, CI:1.46, 6.04, drug addiction(OR: 3.60 CI:1.10, 11.77, history of a sexually transmitted disease(STD(OR 2.00 CI:1.02, 3.90, low social capital (OR:2.81 CI:0.99, 8.03 and heavier alcohol use (OR:2.56 CI: 1.02, 6.46 were significantly more likely to be associated with HIV risk behavior at baseline. In adjusted analysis, age under 41(OR: 4.93, CI: 2.10, 11.58, incarceration history(OR: 3.56 CI:1.55, 8.17 and STD history (OR: 3.48, CI: 1.5, 8.10 continued to be significantly associated with HIV risk behavior. Understanding HIV transmission dynamics in Russia remains an urgent priority to inform strategies to address the epidemic. Larger studies addressing sex differences in risks and barriers to protective behavior are needed.

  8. Structural Dynamic Behavior of Wind Turbines

    Science.gov (United States)

    Thresher, Robert W.; Mirandy, Louis P.; Carne, Thomas G.; Lobitz, Donald W.; James, George H. III

    2009-01-01

    The structural dynamicist s areas of responsibility require interaction with most other members of the wind turbine project team. These responsibilities are to predict structural loads and deflections that will occur over the lifetime of the machine, ensure favorable dynamic responses through appropriate design and operational procedures, evaluate potential design improvements for their impact on dynamic loads and stability, and correlate load and control test data with design predictions. Load prediction has been a major concern in wind turbine designs to date, and it is perhaps the single most important task faced by the structural dynamics engineer. However, even if we were able to predict all loads perfectly, this in itself would not lead to an economic system. Reduction of dynamic loads, not merely a "design to loads" policy, is required to achieve a cost-effective design. The two processes of load prediction and structural design are highly interactive: loads and deflections must be known before designers and stress analysts can perform structural sizing, which in turn influences the loads through changes in stiffness and mass. Structural design identifies "hot spots" (local areas of high stress) that would benefit most from dynamic load alleviation. Convergence of this cycle leads to a turbine structure that is neither under-designed (which may result in structural failure), nor over-designed (which will lead to excessive weight and cost).

  9. Dynamic Behavior of Sand: Annual Report FY 11

    Energy Technology Data Exchange (ETDEWEB)

    Antoun, T; Herbold, E; Johnson, S

    2012-03-15

    Currently, design of earth-penetrating munitions relies heavily on empirical relationships to estimate behavior, making it difficult to design novel munitions or address novel target situations without expensive and time-consuming full-scale testing with relevant system and target characteristics. Enhancing design through numerical studies and modeling could help reduce the extent and duration of full-scale testing if the models have enough fidelity to capture all of the relevant parameters. This can be separated into three distinct problems: that of the penetrator structural and component response, that of the target response, and that of the coupling between the two. This project focuses on enhancing understanding of the target response, specifically granular geomaterials, where the temporal and spatial multi-scale nature of the material controls its response. As part of the overarching goal of developing computational capabilities to predict the performance of conventional earth-penetrating weapons, this project focuses specifically on developing new models and numerical capabilities for modeling sand response in ALE3D. There is general recognition that granular materials behave in a manner that defies conventional continuum approaches which rely on response locality and which degrade in the presence of strong response nonlinearities, localization, and phase gradients. There are many numerical tools available to address parts of the problem. However, to enhance modeling capability, this project is pursuing a bottom-up approach of building constitutive models from higher fidelity, smaller spatial scale simulations (rather than from macro-scale observations of physical behavior as is traditionally employed) that are being augmented to address the unique challenges of mesoscale modeling of dynamically loaded granular materials. Through understanding response and sensitivity at the grain-scale, it is expected that better reduced order representations of response can

  10. Freezing in porous media: Phase behavior, dynamics and transport phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Wettlaufer, John S. [Yale Univ., New Haven, CT (United States)

    2012-12-21

    This research was focused on developing the underlying framework for the mechanisms that control the nature of the solidification of a broad range of porous media. To encompass the scope of porous media under consideration we considered material ranging from a dilute colloidal suspension to a highly packed saturated host matrix with a known geometry. The basic physical processes that occur when the interstitial liquid phase solidifies revealed a host of surprises with a broad range of implications from geophysics to materials science and engineering. We now understand that ostensibly microscopic films of unfrozen liquid control both the equilibrium and transport properties of a highly packed saturated host matrix as well as a rather dilute colloidal suspension. However, our description of the effective medium behavior in these settings is rather different and this sets the stage for the future research based on our past results. Once the liquid phase of a saturated relatively densely packed material is frozen, there is a rich dynamical behavior of particles for example due to the directed motion driven by thermomolecular pressure gradients or the confined Brownian motion of the particles. In quite striking contrast, when one freezes a dilute suspension the behavior can be rather more like that of a binary alloy with the particles playing the role of a ``solute''. We probed such systems quantitatively by (i) using X ray photon correlation spectroscopy (XPCS) and Small Angle X-ray Scattering (SAXS) at the Advanced Photon Source at Argonne (ii) studying the Argonne cell in the laboratory using optical microscopy and imagery (because it is not directly visible while in the vacuum can). (3) analyzed the general transport phenomena within the framework of both irreversible thermodynamics and alloy solidification and (4) applied the results to the study of the redistribution of solid particles in a frozen interstitial material. This research has gone a long way

  11. LD, interpersonal understanding, and social behavior in the classroom.

    Science.gov (United States)

    Kravetz, S; Faust, M; Lipshitz, S; Shalhav, S

    1999-01-01

    This study used Baron and Kenny's (1986) criteria for mediation to investigate the extent to which interpersonal understanding mediates the relation between learning disabilities (LD) and social adaptation in the classroom. Twenty-two children with and 22 children without a diagnosis of LD completed a semistructured developmental clinical interview measure of interpersonal understanding. They were also rated by their fourth- and fifth-grade teachers on a measure of social adaptation in the classroom. Interpersonal understanding and social adaptation in the classroom were found to be positively correlated. Children with LD exhibited less interpersonal understanding and social adaptation. Although this group difference on social adaptation was greatly reduced when interpersonal understanding was statistically controlled, it remained statistically significant. These results suggest that reduced social adaptation in the classroom and lower interpersonal understanding are both associated with a diagnosis of LD. However, they do not conclusively support the claim that interpersonal understanding mediates the relation between LD and social adaptation. Thus, whether the social difficulties of people with LD stem from the same complex phenomena that produce these people's learning problems remains an open question.

  12. Facilitating Understanding of Movements in Dynamic Visualizations: An Embodied Perspective

    NARCIS (Netherlands)

    B.B. de Koning (Björn); H.K. Tabbers (Huib)

    2011-01-01

    textabstractLearners studying mechanical or technical processes via dynamic visualizations often fail to build an accurate mental representation of the system's movements. Based on embodied theories of cognition assuming that action, perception, and cognition are closely intertwined, this paper

  13. Understanding positivity within dynamic team interactions: A statistical discourse analysis

    OpenAIRE

    Lehmann-Willenbrock, N.K.; Chiu, M.M.; Lei, Z.; Kauffeld, S.

    2017-01-01

    Positivity has been heralded for its individual benefits. However, how positivity dynamically unfolds within the temporal flow of team interactions remains unclear. This is an important oversight, as positivity can be key to team problem solving and performance. In this study, we examine how team micro-processes affect the likelihood of positivity occurring within dynamic team interactions. In doing so, we build on and expand previous work on individual positivity and integrate theory on temp...

  14. Some aspects of animal behavior and community dynamics

    Directory of Open Access Journals (Sweden)

    Vikas Rai

    2011-09-01

    Full Text Available We simulate the dynamical behavior of a few two - dimensional predator - prey systems in two - dimensional parameter spaces to gain insight into how functional responses affect community dynamics. The insight gained helps us design three dimensional systems. We construct models for a few ecosystems with three species and study them using computer simulations. The models have been developed by linking food chains which have both kinds of predators: specialist as well as generalist. The linking functions are weakly non-linear. The three dimensional model ecosystems have sexually reproducing top - predators. We perform extensive simulations to figure out dynamics of dynamical possibilities caused by changes in animal behavior. The animals change the foraging strategies and behave differently in different environments. At the end of the paper, we examine how diseases can govern transitions in meandering of dynamical models in bounded volume of their phase spaces.

  15. Study of a spur gear dynamic behavior in transient regime

    Science.gov (United States)

    Khabou, M. T.; Bouchaala, N.; Chaari, F.; Fakhfakh, T.; Haddar, M.

    2011-11-01

    In this paper the dynamic behavior of a single stage spur gear reducer in transient regime is studied. Dynamic response of the single stage spur gear reducer is investigated at different rotating velocities. First, gear excitation is induced by the motor torque and load variation in addition to the fluctuation of meshing stiffness due to the variation of input rotational speed. Then, the dynamic response is computed using the Newmark method. After that, a parameter study is made on spur gear powered in the first place by an electric motor and in the second place by four strokes four cylinders diesel engine. Dynamic responses come to confirm a significant influence of the transient regime on the dynamic behavior of a gear set, particularly in the case of engine acyclism condition.

  16. The Behavioral Dynamics of Youth Smoking

    Science.gov (United States)

    Gilleskie, Donna B.; Strumpf, Koleman S.

    2005-01-01

    The role played by past cigarette consumption and individual heterogeneity in recurrent and persistent youth smoking behavior is studied. The study is based on data collected from teenagers of all the 50 United States, over a period extending from 1988 to 1992.

  17. Understanding driver behavior at grade crossings through signal detection theory.

    Science.gov (United States)

    2013-01-01

    This report uses signal detection theory (SDT) to model motorists decisionmaking strategies at grade crossings in order to understand the factors that influence such decisions and to establish a framework for evaluating the impact of proposed coun...

  18. Understanding driver behavior at grade crossings through signal detection theory.

    Science.gov (United States)

    2013-01-31

    This report uses signal detection theory (SDT) to model motorists decisionmaking strategies at grade crossings in order to understand the factors that influence such decisions and to establish a framework for evaluating the impact of proposed coun...

  19. Dynamic Behavior of Helical Structure in Ferroelectric Liquid Crystals

    Science.gov (United States)

    Katayama, Takashi; Uehara, Hiroyuki; Furue, Hirokazu; Hatano, Jun

    2004-09-01

    Ferroelectric liquid crystals (FLCs) take a helical structure which can be unwound by the application of an electric field. Although the static orientational process of FLC molecules is well known, the dynamic modification process of the helical structure is not clearly understood. We formulated equations for simulating the dynamic response in terms of the elastic free-energy density based on the continuum theory, and subsequently was solved the dynamic equations numerically. Furthermore, the conoscopic image was simulated by a 4× 4 matrix method. We investigated the effect of spontaneous polarization and dielectric anisotropy on the dynamic behavior of the helical structure in FLC.

  20. Toward improving our application and understanding of crown fire behavior

    Science.gov (United States)

    Martin E. Alexander; Miguel G. Cruz; Nicole M. Vaillant

    2014-01-01

    The suggestion has been made that most wildland fire operations personnel base their expectations of how a fire will behave largely on experience and, to a lesser extent, on guides to predicting fire behavior (Burrows 1984). Experienced judgment is certainly needed in any assessment of wildland fire potential but it does have its limitations. The same can be said for...

  1. Understanding Transnational African Migrants' Perspectives of Dietary Behavior.

    Science.gov (United States)

    Ibe-Lamberts, Kelechi; Tshiswaka, Daudet Ilunga; Osideko, Anuolwaupo; Schwingel, Andiara

    2016-10-28

    Dietary behaviors serve as determinants for chronic diseases such as hypertension across various ethnicities worldwide and within the USA. We investigated dietary perspectives specifically for US transnational African migrants, a migrant cohort subset of individuals who maintain cross-border ties with their indigenous communities of origin. Using PEN-3 model, focus group interviews with 14 transnational African migrants (seven males and seven females) were conducted in Chicago to explore the perceptions of dietary behavior in regard to chronic disease risk factors among our target population. The findings underscore that transnational African migrants maintain strong ties with their African community of origin, impacting dietary behaviors and attitudes. Further, transnational African migrants maintain traditional dishes through their connections. Despite the ability to import African traditional foods through personal connections, African migrants face a challenge in maintaining culture yet conforming to norms of acculturation. Results from this study serve to advocate for further exploration of the interaction between African migrant dietary behaviors and risk factors to chronic diseases.

  2. Behavioral accident avoidance science : understanding response in collision incipient conditions

    NARCIS (Netherlands)

    Hancock, P.A.; Ridder, S.N. de

    2003-01-01

    Road traffic accidents are the single greatest cause of fatality in the workplace and the primary cause of all accidental death in the U.S. to the age of seventy-eight. However, behavioral analysis of response in the final seconds and milliseconds before collision has been a most difficult

  3. Children's Behavior toward and Understanding of Robotic and Living Dogs

    Science.gov (United States)

    Melson, Gail F.; Kahn, Peter H., Jr.; Beck, Alan; Friedman, Batya; Roberts, Trace; Garrett, Erik; Gill, Brian T.

    2009-01-01

    This study investigated children's reasoning about and behavioral interactions with a computationally sophisticated robotic dog (Sony's AIBO) compared to a live dog (an Australian Shepherd). Seventy-two children from three age groups (7-9 years, 10-12 years, and 13-15 years) participated in this study. Results showed that more children…

  4. Health Behavior Change Challenge: Understanding Stages of Change

    Science.gov (United States)

    Sullivan, Claire F.

    2011-01-01

    This semester-long activity requires students to reflect on their own strengths and weaknesses in attempting to take on a personally meaningful health behavior change challenge. This assignment affords them the opportunity to take a deeper look at theory and health concepts learned throughout the semester and to see how it has informed their own…

  5. Understanding patients' behavioral intentions: evidence from Iran's private hospitals industry.

    Science.gov (United States)

    Zarei, Ehsan; Arab, Mohammad; Tabatabaei, Seyed Mahmoud Ghazi; Rashidian, Arash; Forushani, Abbas Rahimi; Khabiri, Roghayeh

    2014-01-01

    In the ever-increasing competitive market of private hospital industry, creating a strong relationship with the customers that shapes patients' loyalty has been considered a key factor in obtaining market share. The purpose of this paper is to test a model of customer loyalty among patients of private hospitals in Iran. This cross-sectional study was carried out in Tehran, the capital of the Islamic Republic of Iran in 2010. The study samples composed of 969 patients who were consecutively selected from eight private hospitals. The survey instrument was designed based on a review of the related literature and included 36 items. Data analysis was performed using structural equation modeling. For the service quality construct, three dimensions extracted: Process, interaction, and environment. Both process and interaction quality had significant effects on perceived value. Perceived value along with the process and interaction quality were the most important antecedents of patient overall satisfaction. The direct effect of the process and interaction quality on behavioral intentions was insignificant. Perceived value and patient overall satisfaction were the direct antecedents of patient behavioral intentions and the mediators between service quality and behavioral intentions. Environment quality of service delivery had no significant effect on perceived value, overall satisfaction, and behavioral intentions. Contrary to previous similar studies, the role of service quality was investigated not in a general sense, but in the form of three types of qualities including quality of environment, quality of process, and quality of interaction.

  6. Understanding Homophobic Behavior and Its Implications for Policy and Practice

    Science.gov (United States)

    Poteat, V. Paul; Russell, Stephen T.

    2013-01-01

    In this article, we consider recent advances in scholarship on homophobic bullying, and implications for policy and practice. We first consider toward whom homophobic behavior is directed, drawing attention to the nuances among LGBT youth, and the realities of homophobic bullying for heterosexual or straight youth. We review the correlates or…

  7. Molecular Approaches to Understanding C & N Dynamics in MArine Sediments

    Energy Technology Data Exchange (ETDEWEB)

    Arturo Massol; James Tiedje; Jizhong Zhou; Allan Devol

    2007-05-16

    Continental margin sediments constitute only about 10% of the total sediment surface area in the world’s oceans, nevertheless they are the dominant sites of nitrogen (N) cycling. Recent studies suggest that the oceanic nitrogen budget is unbalanced, primarily due to a higher nitrogen removal rate in contrast to the fixation rate, and it has been suggested that denitrification activity contributes significantly to this imbalance. Although denitrification in marine environments has been studied intensively at the process level, little is known about the species abundance, composition, distribution, and functional differences of the denitrifying population. Understanding the diversity of microbial populations in marine environments, their responses to various environmental factors such as NO3-, and how this impact the rate of denitrification is critical to predict global N dynamics. Environmental Microbiology has the prompt to study the influence of each microbial population on a biogeochemical process within a given ecosystem. Culture-dependent and –independent techniques using nucleic acid probes can access the identity and activity of cultured and uncultured microorganisms. Nucleic acid probes can target distintict genes which set phylogenetic relationships, such as rDNA 16S, DNA gyrase (gyrB) and RNA polymerase sigma 70 factor (rpoD). In the other hand, the genetic capabilities and their expression could be tracked using probes that target several functional genes, such as nirS, nirK, nosZ, and nifH, which are genes involved in denitrification. Selective detection of cells actively expressing functional genes within a community using In Situ Reverse Transcription-PCR (ISRT-PCR) could become a powerful culture-independent technique in microbial ecology. Here we describe an approach to study the expression of nirS genes in denitrifying bacteria. Pure cultures of Pseudomonas stutzeri and Paracoccus denitrificans, as well as co-cultures with non

  8. Understanding Dynamic Model Validation of a Wind Turbine Generator and a Wind Power Plant: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Muljadi, Eduard; Zhang, Ying Chen; Gevorgian, Vahan; Kosterev, Dmitry

    2016-09-01

    Regional reliability organizations require power plants to validate the dynamic models that represent them to ensure that power systems studies are performed to the best representation of the components installed. In the process of validating a wind power plant (WPP), one must be cognizant of the parameter settings of the wind turbine generators (WTGs) and the operational settings of the WPP. Validating the dynamic model of a WPP is required to be performed periodically. This is because the control parameters of the WTGs and the other supporting components within a WPP may be modified to comply with new grid codes or upgrades to the WTG controller with new capabilities developed by the turbine manufacturers or requested by the plant owners or operators. The diversity within a WPP affects the way we represent it in a model. Diversity within a WPP may be found in the way the WTGs are controlled, the wind resource, the layout of the WPP (electrical diversity), and the type of WTGs used. Each group of WTGs constitutes a significant portion of the output power of the WPP, and their unique and salient behaviors should be represented individually. The objective of this paper is to illustrate the process of dynamic model validations of WTGs and WPPs, the available data recorded that must be screened before it is used for the dynamic validations, and the assumptions made in the dynamic models of the WTG and WPP that must be understood. Without understanding the correct process, the validations may lead to the wrong representations of the WTG and WPP modeled.

  9. Sports Related Riots: Understanding Group Behavior To Improve Police Strategy

    Science.gov (United States)

    2016-03-01

    Angeles Police Department MFF Mobile Field Force MPD Madison Police Department NCAA National Collegiate Athletic Association NFL National...a person’s identity is determined by acceptance to a specific group.28 This relationship gives the person a sense of esteem and belonging, while...individualization is the concept of losing one’s self identify to the dynamic of a crowd. In 1946, Jung argued, “being in a crowd leads to the loss of one’s

  10. Understanding Oil Price Behavior through an Analysis of a Crisis

    OpenAIRE

    Leonardo Maugeri

    2009-01-01

    This article seeks to identify and explain both the fundamental and the more controversial elements that shape the dynamics of the oil market, using the recent oil crisis as the basic framework for analysis. The article suggests that the price of oil is essentially a function of the current and future spare capacity of oil. However, spare capacity alone cannot fully explain the extent and timing of oil price movements. Other important factors must be taken into account, including, above all, ...

  11. Thermodynamic and dynamic behaviors of self-organizing polymeric systems

    Science.gov (United States)

    Zhao, Yiqiang

    5OCB, a metastably extended miscible nematic range is observed at low SCLCP concentration upon cooling. Onset of an induced smectic phase occurs upon cooling at 60%wt SCLCP concentration which corresponds to 48:52 molar ratio of mesogens. Dielectric spectra of these mixtures over a wide concentration range exhibit two distinct regimes of relaxation behavior reflecting the crossover from dilute and semidilute to concentrated regime. Rheological behavior of a metallo-supramolecular gel with thixotropic feature is explored to understand the viscoelastic behaviors of self-assembling networks consisting of "living polymers". A well-defined yield point and non-linear viscoelasticity at small strain are probed via the controlled-stress and controlled-strain measurements, respectively. The self-assembled network is readily presheared into a Newtonian sol and displays a three-stage kinetic recovery process, closely associated with the metal ion-ligand binding kinetics and related phase behaviors. Finally, we investigate the viscoelastic properties of a novel colloidal gel in which macrocycles self-assemble into interconnected self-organized clusters. A series of rheological experiments are combined to reveal the shear responsive nature as well as linear and nonlinear viscoelasticity of this gel. Certain features of observed viscoelastic properties demonstrate the characteristics of the behavior of colloidal gels which show slow glassy dynamics. The negative temperature dependence of the storage modulus at low frequency suggests that enthalpic contributions to elasticity need to be considered, presumably due to internal energy changes upon deformation.

  12. Understanding Chinese international college and university students' physical activity behavior

    Directory of Open Access Journals (Sweden)

    Zi Yan

    2015-06-01

    Conclusion: Understanding factors that influence PA among Chinese international students is an important step in the process of promoting their long-term health and wellbeing. Designing program that address the identified key factors may help colleges and universities achieve this goal.

  13. Using Story to Help Student Understanding of Gas Behavior

    Science.gov (United States)

    Wiebe, Rick; Stinner, Arthur

    2010-01-01

    Students tend to have a poor understanding of the concept of gas pressure. Usually, gas pressure is taught in terms of the various formulaic gas laws. The development of the concept of gas pressure according to the early Greeks did not include the concept of a vacuum. It was not for another 2000 years that Torricelli proposed that a vacuum can…

  14. Understanding positivity within dynamic team interactions: A statistical discourse analysis

    NARCIS (Netherlands)

    Lehmann-Willenbrock, N.K.; Chiu, M.M.; Lei, Z.; Kauffeld, S.

    2017-01-01

    Positivity has been heralded for its individual benefits. However, how positivity dynamically unfolds within the temporal flow of team interactions remains unclear. This is an important oversight, as positivity can be key to team problem solving and performance. In this study, we examine how team

  15. Dynamic Reaction Figures: An Integrative Vehicle for Understanding Chemical Reactions

    Science.gov (United States)

    Schultz, Emeric

    2008-01-01

    A highly flexible learning tool, referred to as a dynamic reaction figure, is described. Application of these figures can (i) yield the correct chemical equation by simply following a set of menu driven directions; (ii) present the underlying "mechanism" in chemical reactions; and (iii) help to solve quantitative problems in a number of different…

  16. Exploiting Fast-Variables to Understand Population Dynamics and Evolution

    Science.gov (United States)

    Constable, George W. A.; McKane, Alan J.

    2017-11-01

    We describe a continuous-time modelling framework for biological population dynamics that accounts for demographic noise. In the spirit of the methodology used by statistical physicists, transitions between the states of the system are caused by individual events while the dynamics are described in terms of the time-evolution of a probability density function. In general, the application of the diffusion approximation still leaves a description that is quite complex. However, in many biological applications one or more of the processes happen slowly relative to the system's other processes, and the dynamics can be approximated as occurring within a slow low-dimensional subspace. We review these time-scale separation arguments and analyse the more simple stochastic dynamics that result in a number of cases. We stress that it is important to retain the demographic noise derived in this way, and emphasise this point by showing that it can alter the direction of selection compared to the prediction made from an analysis of the corresponding deterministic model.

  17. Understanding Positivity Within Dynamic Team Interactions : A statistical discourse analysis

    NARCIS (Netherlands)

    Lehmann-Willenbrock, N.; Chiu, Ming Ming; Lei, Zhike; Kauffeld, Simone

    2017-01-01

    Positivity has been heralded for its individual benefits. However, how positivity dynamically unfolds within the temporal flow of team interactions remains unclear. This is an important oversight, as positivity can be key to team problem solving and performance. In this study, we examine how team

  18. Individual Differences in Toddlers’ Social Understanding & Prosocial Behavior: Disposition or Socialization?

    Directory of Open Access Journals (Sweden)

    Rebekkah Lauren Gross

    2015-05-01

    Full Text Available We examined how individual differences in social understanding contribute to variability in early-appearing prosocial behavior. Moreover, potential sources of variability in social understanding were explored and examined as additional possible predictors of prosocial behavior. Using a multi-method approach with both observed and parent-report measures, 325 children aged 18 to 30 months were administered measures of social understanding (e.g. use of emotion words; self-understanding, prosocial behavior (in separate tasks measuring instrumental helping, empathic helping, and sharing, as well as parent-reported prosociality at home, temperament (fearfulness, shyness, and social fear, and parental socialization of prosocial behavior in the family. Individual differences in social understanding predicted variability in empathic helping and parent-reported prosociality, but not instrumental helping or sharing. Parental socialization of prosocial behavior was positively associated with toddlers’ social understanding, prosocial behavior at home, and instrumental helping in the lab, and negatively associated with sharing (possibly reflecting parents’ increased efforts to encourage children who were less likely to share. Further, socialization moderated the association between social understanding and prosocial behavior, such that social understanding was less predictive of prosocial behavior among children whose parents took a more active role in socializing their prosociality. None of the dimensions of temperament was associated with either social understanding or prosocial behavior. Parental socialization of prosocial behavior is thus an important source of variability in children’s early prosociality, acting in concert with early differences in social understanding, with different patterns of influence for different subtypes of prosocial behavior.

  19. Developmental Trajectories of Peer-Reported Aggressive Behavior: The Role of Friendship Understanding, Friendship Quality, and Friends’ Aggressive Behavior

    Science.gov (United States)

    Malti, Tina; McDonald, Kristina; Rubin, Kenneth H.; Rose-Krasnor, Linda; Booth-LaForce, Cathryn

    2015-01-01

    Objective To investigate developmental trajectories in peer-reported aggressive behavior across the transition from elementary-to-middle school, and whether aggressive behavior trajectories were associated with friendship quality, friends’ aggressive behavior, and the ways in which children think about their friendships. Method Participants included a community sample of 230 5th grade children who were assessed when they made a transition from elementary-to-middle school (6th grade). Peer nominations were used to assess the target child’s and friend’s aggressive behavior. Self- and friend reports were used to measure friendship quality; friendship understanding was assessed via a structured interview. Results General Growth Mixture Modeling (GGMM) revealed three distinct trajectories of peer-reported aggressive behavior across the school transition: low-stable, decreasing, and increasing. Adolescents’ understanding of friendship formation differentiated the decreasing from the low-stable aggressive behavior trajectories, and the understanding of friendship trust differentiated the increasing from the low-stable aggressive and decreasing aggressive behavior trajectories. Conclusions The findings indicated that a sophisticated understanding of friendship may serve as a protective factor for initially aggressive adolescents as they transition into middle school. Promoting a deepened understanding of friendship relations and their role in one’s own and others’ well-being may serve as an important prevention and intervention strategy to reduce aggressive behavior. PMID:26688775

  20. Developmental Trajectories of Peer-Reported Aggressive Behavior: The Role of Friendship Understanding, Friendship Quality, and Friends' Aggressive Behavior.

    Science.gov (United States)

    Malti, Tina; McDonald, Kristina; Rubin, Kenneth H; Rose-Krasnor, Linda; Booth-LaForce, Cathryn

    2015-10-01

    To investigate developmental trajectories in peer-reported aggressive behavior across the transition from elementary-to-middle school, and whether aggressive behavior trajectories were associated with friendship quality, friends' aggressive behavior, and the ways in which children think about their friendships. Participants included a community sample of 230 5 th grade children who were assessed when they made a transition from elementary-to-middle school (6 th grade). Peer nominations were used to assess the target child's and friend's aggressive behavior. Self- and friend reports were used to measure friendship quality; friendship understanding was assessed via a structured interview. General Growth Mixture Modeling (GGMM) revealed three distinct trajectories of peer-reported aggressive behavior across the school transition: low-stable, decreasing, and increasing. Adolescents' understanding of friendship formation differentiated the decreasing from the low-stable aggressive behavior trajectories, and the understanding of friendship trust differentiated the increasing from the low-stable aggressive and decreasing aggressive behavior trajectories. The findings indicated that a sophisticated understanding of friendship may serve as a protective factor for initially aggressive adolescents as they transition into middle school. Promoting a deepened understanding of friendship relations and their role in one's own and others' well-being may serve as an important prevention and intervention strategy to reduce aggressive behavior.

  1. Using the Theory of Planned Behavior to Understand the Beliefs of Chinese Teachers Concerning Teaching Games for Understanding

    Science.gov (United States)

    Wang, Lijuan

    2013-01-01

    This study describes the beliefs of Physical Education (PE) teachers regarding Teaching Games for Understanding (TGfU) based on the Theory of Planned Behavior (TPB). Twenty PE teachers participated in this study. Data collection consisted of a survey on demographic data and semistructured interviews. The research results indicate that the teachers…

  2. Understanding water: Molecular dynamics simulations of solubilized and crystallized myoglobin

    International Nuclear Information System (INIS)

    Wei Gu; Garcia, A.E.; Schoenborn, B.P.

    1994-01-01

    Molecular dynamics simulations were performed on CO myoglobin to evaluate the stability of the bound water molecules as determined in a neutron diffraction analysis. The myoglobin structure derived from the neutron analysis provided the starting coordinate set used in the simulations. The simulations show that only a few water molecules are tightly bound to protein atoms, while most solvent molecules are labile, breaking and reforming hydrogen bonds. Comparison between myoglobin in solution and in a single crystal highlighted some of the packing effects on the solvent structure and shows that water solvent plays an indispensable role in protein dynamics and structural stability. The described observations explain some of the differences in the experimental results of protein hydration as observed in NMR, neutron and X-ray diffraction studies

  3. Molecular Modeling of Enzyme Dynamics Towards Understanding Solvent Effects

    DEFF Research Database (Denmark)

    Wedberg, Nils Hejle Rasmus Ingemar

    ) in water and organic solvents. The effects of solvent on structural and dynamical enzyme properties are studied, and special attention is given to how enzyme properties in organic solvents are affected by the hydration level, which is shown to be related to the water activity. In experimental studies...... of enzyme kinetics in non-aqueous media, it has been a fruitful approach to fix the enzyme hydration level by controlling the water activity of the medium. In this work, a protocol is therefore developed for determining the water activity in non-aqueous protein simulations. The method relies on determining......This thesis describes the development of a molecular simulation methodology to study properties of enzymes in non-aqueous media at fixed thermodynamic water activities. The methodology is applied in a molecular dynamics study of the industrially important enzyme Candida antarctica lipase B (CALB...

  4. Avoided critical behavior in dynamically forced wetting.

    Science.gov (United States)

    Snoeijer, Jacco H; Delon, Giles; Fermigier, Marc; Andreotti, Bruno

    2006-05-05

    A solid object can be coated by a nonwetting liquid since a receding contact line cannot exceed a critical speed. In this Letter we study the dynamical wetting transition at which a liquid film gets deposited by withdrawing a vertical plate out of a liquid reservoir. It has recently been predicted that this wetting transition is critical with diverging time scales and coincides with the disappearance of stationary menisci. We demonstrate experimentally and theoretically that the transition is due to the formation of a solitary wave, well below the critical point. As a consequence, relaxation times remain finite at threshold. The structure of the liquid deposited on the plate involves a capillary ridge that does not trivially match the Landau-Levich film.

  5. Goal Directed Model Inversion: A Study of Dynamic Behavior

    Science.gov (United States)

    Colombano, Silvano P.; Compton, Michael; Raghavan, Bharathi; Lum, Henry, Jr. (Technical Monitor)

    1994-01-01

    Goal Directed Model Inversion (GDMI) is an algorithm designed to generalize supervised learning to the case where target outputs are not available to the learning system. The output of the learning system becomes the input to some external device or transformation, and only the output of this device or transformation can be compared to a desired target. The fundamental driving mechanism of GDMI is to learn from success. Given that a wrong outcome is achieved, one notes that the action that produced that outcome 0 "would have been right if the outcome had been the desired one." The algorithm then proceeds as follows: (1) store the action that produced the wrong outcome as a "target" (2) redefine the wrong outcome as a desired goal (3) submit the new desired goal to the system (4) compare the new action with the target action and modify the system by using a suitable algorithm for credit assignment (Back propagation in our example) (5) resubmit the original goal. Prior publications by our group in this area focused on demonstrating empirical results based on the inverse kinematic problem for a simulated robotic arm. In this paper we apply the inversion process to much simpler analytic functions in order to elucidate the dynamic behavior of the system and to determine the sensitivity of the learning process to various parameters. This understanding will be necessary for the acceptance of GDMI as a practical tool.

  6. Modeling dynamic behavior of superconducting maglev systems under external disturbances

    Science.gov (United States)

    Huang, Chen-Guang; Xue, Cun; Yong, Hua-Dong; Zhou, You-He

    2017-08-01

    For a maglev system, vertical and lateral displacements of the levitation body may simultaneously occur under external disturbances, which often results in changes in the levitation and guidance forces and even causes some serious malfunctions. To fully understand the effect of external disturbances on the levitation performance, in this work, we build a two-dimensional numerical model on the basis of Newton's second law of motion and a mathematical formulation derived from magnetoquasistatic Maxwell's equations together with a nonlinear constitutive relation between the electric field and the current density. By using this model, we present an analysis of dynamic behavior for two typical maglev systems consisting of an infinitely long superconductor and a guideway of different arrangements of infinitely long parallel permanent magnets. The results show that during the vertical movement, the levitation force is closely associated with the flux motion and the moving velocity of the superconductor. After being disturbed at the working position, the superconductor has a disturbance-induced initial velocity and then starts to periodically vibrate in both lateral and vertical directions. Meanwhile, the lateral and vertical vibration centers gradually drift along their vibration directions. The larger the initial velocity, the faster their vibration centers drift. However, the vertical drift of the vertical vibration center seems to be independent of the direction of the initial velocity. In addition, due to the lateral and vertical drifts, the equilibrium position of the superconductor in the maglev systems is not a space point but a continuous range.

  7. Pressure effects on dynamics behavior of multiwall boron nitride nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Talebian, Taha [Faculty of Engineering, Neyshabur Branch, Islamic Azad University, Neyshabur (Iran, Islamic Republic of)

    2016-01-15

    The dynamic behavior of Multiwall boron nitride nanotubes (MWBNNTs) is investigated by employing multiple elastic shells model. The influences of van der Waals interactions on layers are shown as nonlinear functions of the interlayer distance of MWBNNTs. Governing equations are solved by using the developed finite element method and by employing time history diagrams. The radial wave speed from the outermost layer to the innermost layer is computed. The effects of geometrical factors such as diameter-to-thickness ratio on dynamic behavior of MWBNNTs are determined. The magnification aspects of MWBNNTs are computed, and the effects of surrounding pressures on wave speed and magnification aspect of MWBNNTs are discussed.

  8. A dynamic-logical perspective on quantum behavior

    OpenAIRE

    Baltag, A.; Smets, S.

    2008-01-01

    In this paper we show how recent concepts from Dynamic Logic, and in particular from Dynamic Epistemic logic, can be used to model and interpret quantum behavior. Our main thesis is that all the non-classical properties of quantum systems are explainable in terms of the non-classical flow of quantum information. We give a logical analysis of quantum measurements (formalized using modal operators) as triggers for quantum information flow, and we compare them with other logical operators previo...

  9. Understanding Patchy Landscape Dynamics: Towards a Landscape Language

    Science.gov (United States)

    Gaucherel, Cédric; Boudon, Frédéric; Houet, Thomas; Castets, Mathieu; Godin, Christophe

    2012-01-01

    Patchy landscapes driven by human decisions and/or natural forces are still a challenge to be understood and modelled. No attempt has been made up to now to describe them by a coherent framework and to formalize landscape changing rules. Overcoming this lacuna was our first objective here, and this was largely based on the notion of Rewriting Systems, also called Formal Grammars. We used complicated scenarios of agricultural dynamics to model landscapes and to write their corresponding driving rule equations. Our second objective was to illustrate the relevance of this landscape language concept for landscape modelling through various grassland managements, with the final aim to assess their respective impacts on biological conservation. For this purpose, we made the assumptions that a higher grassland appearance frequency and higher land cover connectivity are favourable to species conservation. Ecological results revealed that dairy and beef livestock production systems are more favourable to wild species than is hog farming, although in different ways. Methodological results allowed us to efficiently model and formalize these landscape dynamics. This study demonstrates the applicability of the Rewriting System framework to the modelling of agricultural landscapes and, hopefully, to other patchy landscapes. The newly defined grammar is able to explain changes that are neither necessarily local nor Markovian, and opens a way to analytical modelling of landscape dynamics. PMID:23049935

  10. Understanding criminal behavior: Empathic impairment in criminal offenders.

    Science.gov (United States)

    Mariano, Melania; Pino, Maria Chiara; Peretti, Sara; Valenti, Marco; Mazza, Monica

    2017-08-01

    Criminal offenders (CO) are characterized by antisocial and impulsive lifestyles and reduced empathy competence. According to Zaki and Ochsner, empathy is a process that can be divided into three components: mentalizing, emotional sharing and prosocial concern. The aim of our study was to evaluate these competences in 74 criminal subjects compared to 65 controls. The CO group demonstrated a lower ability in measures of mentalizing and sharing, especially in recognizing the mental and emotional states of other people by observing their eyes and sharing other people's emotions. Conversely, CO subjects showed better abilities in prosocial concern measures, such as judging and predicting the emotions and behavior of other people, but they were not able to evaluate the gravity of violations of social rules as well as the control group. In addition, logistic regression results show that the higher the deficits in the mentalizing component are, the higher the probability of committing a crime against another person. Taken together, our results suggest that criminal subjects are able to judge and recognize other people's behavior as right or wrong in a social context, but they are not able to recognize and share the suffering of other people.

  11. Understanding prehospital delay behavior in acute myocardial infarction in women.

    Science.gov (United States)

    Waller, Cynthia G

    2006-12-01

    Studies demonstrate that acute myocardial infarction (AMI) mortality can be reduced if reperfusion therapy is initiated within 1 hour of AMI symptom onset. However, a considerable number of men and women arrive at the emergency department outside of the time frame for thrombolytic and angioplasty effectiveness. This is especially true for women who have been shown to delay longer than men due to their prehospital decision-making process utilized. With a mean total delay time greater than 4 hours, the time interval from symptom onset to transport activation to the hospital consumes the majority of the prehospital phase of emergency cardiac care. The health belief model, self-regulation model, theory of reasoned action, and theory of planned behavior have all been used to describe the prehospital decision-making process of both men and women with an AMI and the variables that impact that process. These models have identified the importance of symptom attribution to cardiac-related causes as a target variable for research and interventions related to care-seeking behavior.

  12. Dynamic Choice Behavior in a Natural Experiment

    DEFF Research Database (Denmark)

    Andersen, Steffen; Harrison, Glenn W.; Lau, Morten

    evidence of some probability weighting, but no loss aversion. We also find evidence that contestants make decisions as if using more than one latent criteria, mixing traditional utility evaluations, probability weighting, and aspiration levels. Fourth, we design and implement laboratory experiments...... linked to current choices. We have four major findings. First, we show that popular utility functions that assume constant relative or absolute risk aversion and expected utility theory defined over the prizes cannot characterize these choices, which exhibit increasing relative risk aversion over prizes...... the income that they bring to the game show. Allowing for this integration of income and game show prizes leads to choice behavior consistent with constant relative risk aversion. Third, we examine th e effects of allowing contestants to make choices characterized by non-standard decision models. We find...

  13. Applying the reasoned action approach to understanding health protection and health risk behaviors.

    Science.gov (United States)

    Conner, Mark; McEachan, Rosemary; Lawton, Rebecca; Gardner, Peter

    2017-12-01

    The Reasoned Action Approach (RAA) developed out of the Theory of Reasoned Action and Theory of Planned Behavior but has not yet been widely applied to understanding health behaviors. The present research employed the RAA in a prospective design to test predictions of intention and action for groups of protection and risk behaviors separately in the same sample. To test the RAA for health protection and risk behaviors. Measures of RAA components plus past behavior were taken in relation to eight protection and six risk behaviors in 385 adults. Self-reported behavior was assessed one month later. Multi-level modelling showed instrumental attitude, experiential attitude, descriptive norms, capacity and past behavior were significant positive predictors of intentions to engage in protection or risk behaviors. Injunctive norms were only significant predictors of intention in protection behaviors. Autonomy was a significant positive predictor of intentions in protection behaviors and a negative predictor in risk behaviors (the latter relationship became non-significant when controlling for past behavior). Multi-level modelling showed that intention, capacity, and past behavior were significant positive predictors of action for both protection and risk behaviors. Experiential attitude and descriptive norm were additional significant positive predictors of risk behaviors. The RAA has utility in predicting both protection and risk health behaviors although the power of predictors may vary across these types of health behavior. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Understanding the dynamics of parent involvement in schooling ...

    African Journals Online (AJOL)

    Erna Kinsey

    themselves pose barriers for both children and parents in the schooling system. Furthermore, results highlighted the central role that schools can play in increasing the degree of parental support, as well as ways in which to understand the support needed by these parents. The stress on parents and their relationships with ...

  15. Revisiting Hele-Shaw dynamics to better understand beach evolution

    NARCIS (Netherlands)

    Bokhove, Onno; van der Horn, Avraham/Bram; van der Horn, A.J.; van der Meer, Roger M.; Gagarina, Elena; Zweers, W.; Thornton, Anthony Richard

    Wave action, particularly during storms, drives the evo lution of beaches. Beach evolution by non-linear break ing waves is poorly understood due to its three-dimensional character, the range of scales involved, and our limited understanding of particle-wave interactions. We show how a novel,

  16. Understanding the Relationship Between Subjective Wellbeing and Gambling Behavior.

    Science.gov (United States)

    Farrell, Lisa

    2018-03-01

    This paper examines the relationship between gambling behavior and subjective wellbeing. It is often asserted that populations consist of different types of gamblers: those for whom gambling is a harmless leisure activity and those (pathological/problem gamblers) for whom the activity has harmful effects. One might, therefore, assume that subjective wellbeing will be negativity associated with an individual's level of gambling addiction. Alternatively, gamblers may choose to gamble because they derive utility from participating in this activity and so the relationship between happiness and gambling might be positively correlated. In this paper we test this association, empirically, using data from the 2010 British Gambling Prevalence Survey. The statistically significant findings from this analysis support the hypothesis that individual wellbeing falls as gambling disorder increases.

  17. Students’ online purchasing behavior in Malaysia: Understanding online shopping attitude

    Directory of Open Access Journals (Sweden)

    Marzieh Zendehdel

    2015-12-01

    Full Text Available Studies examining the factors that affect the online purchasing behavior of consumers are rare, despite the prospective advance of e-commerce in Malaysia. The present study examines particular factors that influence the attitude of potential consumers to purchase online by using the attributes from the diffusion of innovations theory of Rogers, the attribute of perception of risk, and the subjective norms toward online purchasing. Consumers’ perceived risks of online shopping have become a vital subject in research because they directly influence users’ attitude toward online purchasing. The structural equation modeling method was used to analyze the data gathered on students using e-commerce, and, thus, to validate the model. According to the results, consumers’ attitude toward online purchasing affects the intention toward online purchasing. The other influential factors are compatibility, relative advantage, and subjective norm.

  18. Understanding change in recycling and littering behavior across a school social network.

    Science.gov (United States)

    Long, Jennifer; Harré, Niki; Atkinson, Quentin D

    2014-06-01

    Understanding how communities change requires examining how individuals' beliefs and behaviors are shaped by those around them. This paper investigates behavior change across a large social network following a recycling intervention in a New Zealand high school community. We used a mixed methods design, combining focus group data with social network analysis from two waves of a questionnaire that measured friendship networks; recycling and littering behaviors; perceived behavioral norms; and teacher, friend, and parent encouragement for these behaviors. Recycling behavior increased significantly over the course of our study. Supporting the importance of social networks in this context, both littering and recycling behavior showed clear social clustering. Further, the degree of change in an individuals' littering and recycling behavior across time was predicted by friends' prior behavior. Focus group data provided insight into students' perceptions of social interactions and how these contributed to littering and recycling behavior.

  19. Understanding the Offender/Environment Dynamic for Computer Crimes

    DEFF Research Database (Denmark)

    Willison, Robert Andrew

    2005-01-01

    practices by possiblyhighlighting new areas for safeguard implementation. To help facilitate a greaterunderstanding of the offender/environment dynamic, this paper assesses the feasibilityof applying criminological theory to the IS security context. More specifically, threetheories are advanced, which focus...... on the offender's behaviour in a criminal setting. Drawing on an account of the Barings Bank collapse, events highlighted in the casestudy are used to assess whether concepts central to the theories are supported by thedata. It is noted that while one of the theories is to be found wanting in terms ofconceptual...

  20. Generative modelling of regulated dynamical behavior in cultured neuronal networks

    Science.gov (United States)

    Volman, Vladislav; Baruchi, Itay; Persi, Erez; Ben-Jacob, Eshel

    2004-04-01

    The spontaneous activity of cultured in vitro neuronal networks exhibits rich dynamical behavior. Despite the artificial manner of their construction, the networks’ activity includes features which seemingly reflect the action of underlying regulating mechanism rather than arbitrary causes and effects. Here, we study the cultured networks dynamical behavior utilizing a generative modelling approach. The idea is to include the minimal required generic mechanisms to capture the non-autonomous features of the behavior, which can be reproduced by computer modelling, and then, to identify the additional features of biotic regulation in the observed behavior which are beyond the scope of the model. Our model neurons are composed of soma described by the two Morris-Lecar dynamical variables (voltage and fraction of open potassium channels), with dynamical synapses described by the Tsodyks-Markram three variables dynamics. The model neuron satisfies our self-consistency test: when fed with data recorded from a real cultured networks, it exhibits dynamical behavior very close to that of the networks’ “representative” neuron. Specifically, it shows similar statistical scaling properties (approximated by similar symmetric Lévy distribution with finite mean). A network of such M-L elements spontaneously generates (when weak “structured noise” is added) synchronized bursting events (SBEs) similar to the observed ones. Both the neuronal statistical scaling properties within the bursts and the properties of the SBEs time series show generative (a new discussed concept) agreement with the recorded data. Yet, the model network exhibits different structure of temporal variations and does not recover the observed hierarchical temporal ordering, unless fed with recorded special neurons (with much higher rates of activity), thus indicating the existence of self-regulation mechanisms. It also implies that the spontaneous activity is not simply noise-induced. Instead, the

  1. Harsh parenting, child behavior problems, and the dynamic coupling of parents' and children's positive behaviors.

    Science.gov (United States)

    Lunkenheimer, Erika; Ram, Nilam; Skowron, Elizabeth A; Yin, Peifeng

    2017-09-01

    We examined self-reported maternal and paternal harsh parenting (HP) and its effect on the moment-to-moment dynamic coupling of maternal autonomy support and children's positive, autonomous behavior. This positive behavior coupling was measured via hidden Markov models as the likelihood of transitions into specific positive dyadic states in real time. We also examined whether positive behavior coupling, in turn, predicted later HP and child behavior problems. Children (N = 96; age = 3.5 years at Time 1) and mothers completed structured clean-up and puzzle tasks in the laboratory. Mothers' and fathers' HP was associated with children's being less likely to respond positively to maternal autonomy support; mothers' HP was also associated with mothers' being less likely to respond positively to children's autonomous behavior. When mothers responded to children's autonomous behavior with greater autonomy support, children showed fewer externalizing and internalizing problems over time and mothers showed less HP over time. These results were unique to the dynamic coupling of maternal autonomy support and children's autonomous behavior: The overall amount of these positive behaviors did not similarly predict reduced problems. Findings suggest that HP in the family system compromises the coregulation of positive behavior between mother and child and that improving mothers' and children's abilities to respond optimally to one another's autonomy-supportive behaviors may reduce HP and child behavior problems over time. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  2. The secret society and the social dynamics of terrorist behavior.

    Science.gov (United States)

    Mackert, Jürgen

    2014-01-01

    The article argues that individualist accounts cannot adequately explain the social dynamics of terrorist behavior as they turn analyses of terrorism into analyses of terrorists. A relational approach that concentrates on the social relations between terrorist organizations and their members would be able to do this, however. Therefore, the article presents a formal analysis that makes the "secret society" of terrorists the lynchpin of an explanation of how terrorist organizations shape the behavioral conditions of volunteers and suicide terrorists in a manner that triggers a type of behavior we might call terrorism.

  3. Compliance pluralisme and processes : Understanding compliance behavior in restaurants in China

    NARCIS (Netherlands)

    Wu, Y.

    2017-01-01

    This research aimed to offer a case study of dynamic compliance processes in selected Chinese restaurants with the main methods of participant observation and in-depth interviews. It applied an integrated and dynamic research approach, called descriptive analysis of compliance behavior, which

  4. Visualizing and Understanding Socio-Environmental Dynamics in Baltimore

    Science.gov (United States)

    Zaitchik, B. F.; Omeara, K.; Guikema, S.; Scott, A.; Bessho, A.; Logan, T. M.

    2015-12-01

    The City of Baltimore, like any city, is the sum of its component neighborhoods, institutions, businesses, cultures, and, ultimately, its people. It is also an organism in its own right, with distinct geography, history, infrastructure, and environments that shape its residents even as it is shaped by them. Sometimes these interactions are obvious but often they are not; while basic economic patterns are widely documented, the distribution of socio-spatial and environmental connections often hides below the surface, as does the potential that those connections hold. Here we present results of a collaborative initiative on the geography, design, and policy of socio-environmental dynamics of Baltimore. Geospatial data derived from satellite imagery, demographic databases, social media feeds, infrastructure plans, and in situ environmental networks, among other sources, are applied to generate an interactive portrait of Baltimore City's social, health, and well-being dynamics. The layering of data serves as a platform for visualizing the interconnectedness of the City and as a database for modeling risk interactions, vulnerabilities, and strengths within and between communities. This presentation will provide an overview of project findings and highlight linkages to education and policy.

  5. Understanding Social Contagion in Adoption Processes Using Dynamic Social Networks.

    Science.gov (United States)

    Herrera, Mauricio; Armelini, Guillermo; Salvaj, Erica

    2015-01-01

    There are many studies in the marketing and diffusion literature of the conditions in which social contagion affects adoption processes. Yet most of these studies assume that social interactions do not change over time, even though actors in social networks exhibit different likelihoods of being influenced across the diffusion period. Rooted in physics and epidemiology theories, this study proposes a Susceptible Infectious Susceptible (SIS) model to assess the role of social contagion in adoption processes, which takes changes in social dynamics over time into account. To study the adoption over a span of ten years, the authors used detailed data sets from a community of consumers and determined the importance of social contagion, as well as how the interplay of social and non-social influences from outside the community drives adoption processes. Although social contagion matters for diffusion, it is less relevant in shaping adoption when the study also includes social dynamics among members of the community. This finding is relevant for managers and entrepreneurs who trust in word-of-mouth marketing campaigns whose effect may be overestimated if marketers fail to acknowledge variations in social interactions.

  6. Understanding Social Contagion in Adoption Processes Using Dynamic Social Networks.

    Directory of Open Access Journals (Sweden)

    Mauricio Herrera

    Full Text Available There are many studies in the marketing and diffusion literature of the conditions in which social contagion affects adoption processes. Yet most of these studies assume that social interactions do not change over time, even though actors in social networks exhibit different likelihoods of being influenced across the diffusion period. Rooted in physics and epidemiology theories, this study proposes a Susceptible Infectious Susceptible (SIS model to assess the role of social contagion in adoption processes, which takes changes in social dynamics over time into account. To study the adoption over a span of ten years, the authors used detailed data sets from a community of consumers and determined the importance of social contagion, as well as how the interplay of social and non-social influences from outside the community drives adoption processes. Although social contagion matters for diffusion, it is less relevant in shaping adoption when the study also includes social dynamics among members of the community. This finding is relevant for managers and entrepreneurs who trust in word-of-mouth marketing campaigns whose effect may be overestimated if marketers fail to acknowledge variations in social interactions.

  7. Understanding externalizing behavior from children's personality and parenting characteristics.

    Science.gov (United States)

    Hiramura, Hidetoshi; Uji, Masayo; Shikai, Noriko; Chen, Zi; Matsuoka, Nao; Kitamura, Toshinori

    2010-01-30

    A total of 946 Japanese children in the 5th to 9th grades and their parents were studied in order to investigate the extent to which parenting characteristics (measured by the Parental Bonding Instrument) and the personality of the child (measured by the junior version of the Temperament and Character Inventory) would be associated with the two aspects of the externalizing problems--aggression and delinquency--of the child (measured by the Child Behavior Checklist). A series of regression analyses demonstrated that (1) aggressive children were higher in Novelty Seeking, and delinquent children were higher in Novelty Seeking and lower in Harm Avoidance, and (2) both aggressive and delinquent children were characterised by low maternal care, paternal over-protection, and low maternal overprotection. A structural equation model confirmed these findings except for the link between the two externalizing behaviour scores and the maternal care. Moreover, it was suggested that Novelty seeking of the child would be predicted by low parental care and low paternal and high maternal overprotection. The children's aggression and delinquency could, to some extent, be explainable by their temperament patterns and parental characteristics.

  8. Technicolor and the asymptotic behavior of dynamically generated masses

    International Nuclear Information System (INIS)

    Natale, A.A.

    1984-01-01

    Arguments are given in favor of a hard asymptotic behavior of dynamically generated masses, its consequences for technicolor models are analyzed and a model is proposed, where effects of flavor changing neutral currents are highly supressed and pseudo Goldstone bosons get masses of O(30-90) GeV. (Author) [pt

  9. Simulation of long-term dynamic behavior of runaway electrons

    International Nuclear Information System (INIS)

    Wang Yulei; Liu Jian; Zhang Ruili; He Yang

    2015-01-01

    The secular dynamics of runaway electrons in Tokamak electromagnetic field is studied. The radiation effect is added into a relativistic volume-preserving algorithm to gain long-term stability of calculation. The results shows that the method we used is able to reveal the behavior of a runaway electron in configuration space. (author)

  10. The Feldenkrais Method: A Dynamic Approach to Changing Motor Behavior.

    Science.gov (United States)

    Buchanan, Patricia A.; Ulrich, Beverly D.

    2001-01-01

    Describes the Feldenkrais Method of somatic education, noting parallels with a dynamic systems theory (DST) approach to motor behavior. Feldenkrais uses movement and perception to foster individualized improvement in function. DST explains that a human-environment system continually adapts to changing conditions and assembles behaviors…

  11. Understanding Dynamic Competitive Technology Diffusion in Electronic Markets

    Science.gov (United States)

    Zhang, Cheng; Song, Peijian; Xu, Yunjie; Xue, Ling

    The extant literature on information technology (IT) diffusion has largely treated technology diffusion as a generic and independent process. This study, in contrast, examines the diffusion of different IT products with brand differentiation and competition. Drawing upon existing theories of product diffusion, we propose a research model to capture the dynamics of the competitive diffusion of web-based IT products and validate it with longitudinal field data of e-business platforms. Our findings suggest that IT product diffusion can be better predicted by a competitive model than by an independent-diffusion-process model. This research extends IT research to the context of competitive diffusion and provides practitioners an effective model to predict the dissemination of their products. The research also suggests the existence of asymmetric interactions among competing products, prompting scholars and practitioners to pay attention to the influence of competing products when making forecast of their product market.

  12. Evolution of Secondary Software Businesses: Understanding Industry Dynamics

    Science.gov (United States)

    Tyrväinen, Pasi; Warsta, Juhani; Seppänen, Veikko

    Primary software industry originates from IBM's decision to unbundle software-related computer system development activities to external partners. This kind of outsourcing from an enterprise internal software development activity is a common means to start a new software business serving a vertical software market. It combines knowledge of the vertical market process with competence in software development. In this research, we present and analyze the key figures of the Finnish secondary software industry, in order to quantify its interaction with the primary software industry during the period of 2000-2003. On the basis of the empirical data, we present a model for evolution of a secondary software business, which makes explicit the industry dynamics. It represents the shift from internal software developed for competitive advantage to development of products supporting standard business processes on top of standardized technologies. We also discuss the implications for software business strategies in each phase.

  13. Understanding the dynamic ionospheric signature of the plasmapause (Invited)

    Science.gov (United States)

    Moldwin, M.; Sibanda, P.; Zou, S.; Yizengaw, E.

    2010-12-01

    The equatorial edge of the mid-latitude trough has been shown to be an ionospheric signature of the plasmapause from both ground-based and space-based observations. However, identifying the trough is not always possible due to broad latitudinal density gradients, local time and seasonal effects, and storm and substorm dynamics. We review the current methods of identifying the trough from ground and space-based observations and describe the main deficiencies in these methods especially for tracking the trough/plasmapause during storms and substorms. We discuss the ionospheric signature of plasmaspheric plumes and their relationship to trough/plasmapause signatures. We conclude with some new multi-instrument observations that help clarify the ionospheric trough signature during geomagnetically active periods.

  14. Applying theory-driven approaches to understanding and modifying clinicians' behavior: what do we know?

    Science.gov (United States)

    Perkins, Matthew B; Jensen, Peter S; Jaccard, James; Gollwitzer, Peter; Oettingen, Gabriele; Pappadopulos, Elizabeth; Hoagwood, Kimberly E

    2007-03-01

    Despite major recent research advances, large gaps exist between accepted mental health knowledge and clinicians' real-world practices. Although hundreds of studies have successfully utilized basic behavioral science theories to understand, predict, and change patients' health behaviors, the extent to which these theories-most notably the theory of reasoned action (TRA) and its extension, the theory of planned behavior (TPB)-have been applied to understand and change clinician behavior is unclear. This article reviews the application of theory-driven approaches to understanding and changing clinician behaviors. MEDLINE and PsycINFO databases were searched, along with bibliographies, textbooks on health behavior or public health, and references from experts, to find article titles that describe theory-driven approaches (TRA or TPB) to understanding and modifying health professionals' behavior. A total of 19 articles that detailed 20 studies described the use of TRA or TPB and clinicians' behavior. Eight articles describe the use of TRA or TPB with physicians, four relate to nurses, three relate to pharmacists, and two relate to health workers. Only two articles applied TRA or TPB to mental health clinicians. The body of work shows that different constructs of TRA or TPB predict intentions and behavior among different groups of clinicians and for different behaviors and guidelines. The number of studies on this topic is extremely limited, but they offer a rationale and a direction for future research as well as a theoretical basis for increasing the specificity and efficiency of clinician-targeted interventions.

  15. Applied behavior analysis: understanding and changing behavior in the community-a representative review.

    Science.gov (United States)

    Luyben, Paul D

    2009-01-01

    Applied behavior analysis, a psychological discipline, has been characterized as the science of behavior change (Chance, 2006). Research in applied behavior analysis has been published for approximately 40 years since the initial publication of the Journal of Applied Behavior Analysis in 1968. The field now encompasses a wide range of human behavior. Although much of the published research centers on problem behaviors that occur in schools and among people with disabilities, a substantial body of knowledge has emerged in community settings. This article provides a review of the behavioral community research published in the Journal of Applied Behavior Analysis as representative of this work, including research in the areas of home and family, health, safety, community involvement and the environment, recreation and sports, crime and delinquency, and organizations. In the interest of space, research in schools and with people with disabilities has been excluded from this review.

  16. Empirical modeling of dynamic behaviors of pneumatic artificial muscle actuators.

    Science.gov (United States)

    Wickramatunge, Kanchana Crishan; Leephakpreeda, Thananchai

    2013-11-01

    Pneumatic Artificial Muscle (PAM) actuators yield muscle-like mechanical actuation with high force to weight ratio, soft and flexible structure, and adaptable compliance for rehabilitation and prosthetic appliances to the disabled as well as humanoid robots or machines. The present study is to develop empirical models of the PAM actuators, that is, a PAM coupled with pneumatic control valves, in order to describe their dynamic behaviors for practical control design and usage. Empirical modeling is an efficient approach to computer-based modeling with observations of real behaviors. Different characteristics of dynamic behaviors of each PAM actuator are due not only to the structures of the PAM actuators themselves, but also to the variations of their material properties in manufacturing processes. To overcome the difficulties, the proposed empirical models are experimentally derived from real physical behaviors of the PAM actuators, which are being implemented. In case studies, the simulated results with good agreement to experimental results, show that the proposed methodology can be applied to describe the dynamic behaviors of the real PAM actuators. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

  17. Understanding the behavior of buried Bi nanostructures from first principles

    Science.gov (United States)

    Sims, Hunter; Pantelides, Sokrates; Song, Jiaming; Hudak, Bethany; Lupini, Andrew; Snijders, Paul

    Bismuth dopants in silicon provide several advantages over other n-type options such as phosphorus for usage as quantum bits (qubits). Self-assembled Bi nanolines on Si (100) surfaces may provide a means of introducing these dopants with greater control over placement and with less damage to the host system than is possible using ion implantation. However, these structures have thus far only been observed in vacuum, limiting their usefulness for application. We examine Bi nanolines overgrown with amorphous Si using density functional theory, comparing our findings with observations from scanning tunneling microscopy (STM) and atomic-resolution scanning transmission electron microscopy (STEM) in order to better understand the way in which the Si surface is influenced by both the Bi ad-dimers and the capping layer. We compare the thermodynamic stability of the generally accepted haiku defect core to the modified core that we observe and offer insight from total energy calculations into how the overgrowth process affects the nanolines. Supported by Department of Energy Grant DE-FG02- 09ER46554 (VU) and by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U. S. Department of Energy (ORNL).

  18. Steady State Dynamic Operating Behavior of Universal Motor

    Directory of Open Access Journals (Sweden)

    Muhammad Khan Burdi

    2015-01-01

    Full Text Available A detailed investigation of the universal motor is developed and used for various dynamic steady state and transient operating conditions of loads. In the investigation, output torque, motor speed, input current, input/output power and efficiency are computed, compared and analyzed for different loads. While this paper discusses the steady-state behavior of the universal motor, another companion paper, ?Transient dynamic behavior of universal motor?, will discuss its transient behavior in detail. A non-linear generalized electric machine model of the motor is considered for the analysis. This study was essential to investigate effect of output load on input current, power, speed and efficiency of the motor during operations. Previously such investigation is not known

  19. Understanding the major transitions in Quaternary climate dynamics

    Science.gov (United States)

    Willeit, Matteo; Ganopolski, Andrey

    2017-04-01

    Climate dynamics over the past 3 million years was characterized by strong variability associated with glacial cycles and several distinct regime changes. The Pliocene-Pleistocene Transition (PPT), which happened around 2.7 million years ago, was characterized by the appearance of the large continental ice sheets over Northern Eurasia and North America. For two million years after the PPT climate variability was dominated by relatively symmetric 40 kyr cycles. At around 1 million years ago the dominant mode of climate variability experienced a relatively rapid transition from 40 kyr to strongly asymmetric 100 kyr cycles of larger amplitude (Mid-Pleistocene Transition). Additionally, during the past 800 kyr there are clear differences between the earlier and the later glacial cycles with the last five cycles characterized by larger magnitude of variability (Mid-Brunhes Event). Here, we use the Earth system model of intermediate complexity CLIMBER-2 to explore possible mechanisms that could explain these regime shifts. CLIMBER-2 incorporates all major components of the Earth system - atmosphere, ocean, land surface, northern hemisphere ice sheets, terrestrial biota and soil carbon, marine biogeochemistry and aeolian dust. The model was optimally tuned to reproduce climate, ice volume and CO2 variability over the last 400,000 years. Using the same model version, we performed a large set of simulations covering the entire Quaternary (3 million years) starting from identical initial conditions and using a parallelization in time technique which consists of starting the model at different times (every 100,000 years) and running each simulation for 500,000 years. The Earth's orbital variations are the only prescribed radiative forcing. Several sets of the Northern Hemisphere orography and sediment thickness representing different stages of landscape evolution during the Quaternary are prescribed as boundary conditions for the ice sheet model and volcanic CO2 outgassing is

  20. A system dynamics approach to understanding the One Health concept.

    Directory of Open Access Journals (Sweden)

    Tai Xie

    Full Text Available There have been many terms used to describe the One Health concept, including movement, strategy, framework, agenda, approach, among others. However, the inter-relationships of the disciplines engaged in the One Health concept have not been well described. To identify and better elucidate the internal feedback mechanisms of One Health, we employed a system dynamics approach. First, a systematic literature review was conducted via searches in PubMed, Web of Knowledge, and ProQuest with the search terms: 'One Health' and (concept* or approach*. In addition, we used the HistCite® tool to add significant articles on One Health to the library. Then, of the 2368 articles identified, 19 were selected for evaluating the inter-relationships of disciplines engaged in One Health. Herein, we report a visually rich, theoretical model regarding interactions of various disciplines and complex problem descriptors engaged in One Health problem solving. This report provides a conceptual framework for future descriptions of the interdisciplinary engagements involved in One Health.

  1. Understanding Lithium Solvation and Diffusion through Topological Analysis of First-Principles Molecular Dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Bhatia, Harsh [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Gyulassy, Attila [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ong, Mitchell [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Lordi, Vincenzo [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Draeger, Erik [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Pask, John [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Pascucci, Valerio [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bremer, Peer -Timo [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-09-27

    The performance of lithium-ion batteries is strongly influenced by the ionic conductivity of the electrolyte, which depends on the speed at which Li ions migrate across the cell and relates to their solvation structure. The choice of solvent can greatly impact, both, the solvation and diffusivity of Li ions. In this work, we present our application of the topological techniques to extract and predict such behavior in the data generated by the first-principles molecular dynamics simulation of Li ions in an important organic solvent -ethylene carbonate. More specifically, we use the scalar topology of the electron charge density field to analyze the evolution of the solvation structures. This allows us to derive a parameter-free bond definition for lithium-oxygen bonds, to provide a quantitative measure for bond strength, and to understand the regions of influence of each atom in the simulation. This has provided new insights into how and under what conditions certain bonds may form and break. As a result, we can identify and, more importantly, predict, unstable configurations in solvation structures. This can be very useful in understanding when small changes to the atoms' movements can cause significantly different bond structures to evolve. Ultimately, this promises to allow scientists to explore lithium ion solvation and diffusion more systematically, with the aim of new insights and potentially accelerating the calculations themselves.

  2. Dynamic magnetic hysteresis behavior and dynamic phase transition in the spin-1 Blume-Capel model

    Energy Technology Data Exchange (ETDEWEB)

    Deviren, Bayram, E-mail: bayram.deviren@nevsehir.edu.tr [Department of Physics, Nevsehir University, 50300 Nevsehir (Turkey); Keskin, Mustafa [Department of Physics, Erciyes University, 38039 Kayseri (Turkey)

    2012-03-15

    The nature (time variation) of response magnetization m(wt) of the spin-1 Blume-Capel model in the presence of a periodically varying external magnetic field h(wt) is studied by employing the effective-field theory (EFT) with correlations as well as the Glauber-type stochastic dynamics. We determine the time variations of m(wt) and h(wt) for various temperatures, and investigate the dynamic magnetic hysteresis behavior. We also investigate the temperature dependence of the dynamic magnetization, hysteresis loop area and correlation near the transition point in order to characterize the nature (first- or second-order) of the dynamic transitions as well as obtain the dynamic phase transition temperatures. The hysteresis loops are obtained for different reduced temperatures and we find that the areas of the loops are decreasing with the increasing of the reduced temperatures. We also present the dynamic phase diagrams and compare the results of the EFT with the results of the dynamic mean-field approximation. The phase diagrams exhibit many dynamic critical points, such as tricritical ( Bullet ), zero-temperature critical (Z), triple (TP) and multicritical (A) points. According to values of Hamiltonian parameters, besides the paramagnetic (P), ferromagnetic (F) fundamental phases, one coexistence or mixed phase region, (F+P) and the reentrant behavior exist in the system. The results are in good agreement with some experimental and theoretical results. - Highlights: Black-Right-Pointing-Pointer Kinetic spin-1 Blume-Capel model is studied using the effective-field theory. Black-Right-Pointing-Pointer We investigated the dynamic magnetic hysteresis behavior. Black-Right-Pointing-Pointer Dynamic magnetization, hysteresis loop area and correlation are investigated. Black-Right-Pointing-Pointer System exhibits tricritical, zero-temperature, triple and multicritical points. Black-Right-Pointing-Pointer We present the dynamic phase diagrams and compare the results of the EFT

  3. Understanding Magmatic Plumbing System Dynamics at Fernandina Island, Galapagos

    Science.gov (United States)

    Varga, K. C.; McGuire, M.; Geist, D.; Harpp, K. S.

    2015-12-01

    Fernandina is the most active Galápagos volcano, and is located closest to the seismically defined hotspot. Allan and Simkin (2000) observed that the subaerial edifice is constructed of homogeneous basalts (Mg# = 49 ± 2) with highly variable plagioclase phenocryst contents and sparse olivine. Geist et al. (2006) proposed a magmatic plumbing system in which the volcano is supplied by interconnected sills, the shallowest of which is density-stratified: olivine and pyroxene are concentrated at greater depths, whereas less dense plagioclase mush is higher in the sill. Consequently, olivine-rich lava erupts laterally during submarine events, but plagioclase-rich lava supplies subaerial vents. To test this hypothesis, we examine lavas erupted in 1995, 2005, and 2009. These SW flank eruptions emerged alternatively from en echelon radial fissures on the lower flanks and circumferential fissures near the caldera rim. The 1995 radial fissure unzipped downslope and then formed a cone 4 km from the coast, sending flows to the ocean. In 2005, circumferential fissures erupted five flows south of the 1995 fissure. As in 1995, the 2009 fissures opened down the SW flank before focusing to a cone near the 1995 vents, producing 6 km-long flows that also reached the ocean. By correlating plagioclase crystal size distribution and morphologies with single event chronological sequences, we examine Fernandina's magmatic plumbing system. Modal plagioclase in 1995 lava decreases (20% to <5%) throughout the middle eruptive phase. Early 2005 samples are nearly aphyric (Chadwick et al., 2010), with 1-2% plagioclase. The 2009 eruption has reduced plagioclase, similar to mid-1995 samples. Preliminary observations suggest that less plagioclase-rich mush is being flushed out during early-to-medial event sequences, whereas plag phenocrysts are transported more during later phases. Plausible plumbing dynamics suggest a zone of plagioclase-rich mush that is eroded and incorporated into radial

  4. An in silico modeling approach to understanding the dynamics of sarcoidosis.

    Directory of Open Access Journals (Sweden)

    Baltazar D Aguda

    Full Text Available BACKGROUND: Sarcoidosis is a polygenic disease with diverse phenotypic presentations characterized by an abnormal antigen-mediated Th1 type immune response. At present, progress towards understanding sarcoidosis disease mechanisms and the development of novel treatments is limited by constraints attendant to conducting human research in a rare disease in the absence of relevant animal models. We sought to develop a computational model to enhance our understanding of the pathological mechanisms of and predict potential treatments of sarcoidosis. METHODOLOGY/RESULTS: Based upon the literature, we developed a computational model of known interactions between essential immune cells (antigen-presenting macrophages, effector and regulatory T cells and cytokine mediators (IL-2, TNFα, IFNγ of granulomatous inflammation during sarcoidosis. The dynamics of these interactions are described by a set of ordinary differential equations. The model predicts bistable switching behavior which is consistent with normal (self-limited and "sarcoidosis-like" (sustained activation of the inflammatory components of the system following a single antigen challenge. By perturbing the influence of model components using inhibitors of the cytokine mediators, distinct clinically relevant disease phenotypes were represented. Finally, the model was shown to be useful for pre-clinical testing of therapies based upon molecular targets and dose-effect relationships. CONCLUSIONS/SIGNIFICANCE: Our work illustrates a dynamic computer simulation of granulomatous inflammation scenarios that is useful for the investigation of disease mechanisms and for pre-clinical therapeutic testing. In lieu of relevant in vitro or animal surrogates, our model may provide for the screening of potential therapies for specific sarcoidosis disease phenotypes in advance of expensive clinical trials.

  5. Fractional Relativistic Yamaleev Oscillator Model and Its Dynamical Behaviors

    Science.gov (United States)

    Luo, Shao-Kai; He, Jin-Man; Xu, Yan-Li; Zhang, Xiao-Tian

    2016-07-01

    In the paper we construct a new kind of fractional dynamical model, i.e. the fractional relativistic Yamaleev oscillator model, and explore its dynamical behaviors. We will find that the fractional relativistic Yamaleev oscillator model possesses Lie algebraic structure and satisfies generalized Poisson conservation law. We will also give the Poisson conserved quantities of the model. Further, the relation between conserved quantities and integral invariants of the model is studied and it is proved that, by using the Poisson conserved quantities, we can construct integral invariants of the model. Finally, the stability of the manifold of equilibrium states of the fractional relativistic Yamaleev oscillator model is studied. The paper provides a general method, i.e. fractional generalized Hamiltonian method, for constructing a family of fractional dynamical models of an actual dynamical system.

  6. Domain decomposition-based structural condensation of large protein structures for understanding their conformational dynamics.

    Science.gov (United States)

    Kim, Jae In; Na, Sungsoo; Eom, Kilho

    2011-01-15

    Normal mode analysis (NMA) with coarse-grained model, such as elastic network model (ENM), has allowed the quantitative understanding of protein dynamics. As the protein size is increased, there emerges the expensive computational process to find the dynamically important low-frequency normal modes due to diagonalization of massive Hessian matrix. In this study, we have provided the domain decomposition-based structural condensation method that enables the efficient computations on low-frequency motions. Specifically, our coarse-graining method is established by coupling between model condensation (MC; Eom et al., J Comput Chem 2007, 28, 1400) and component mode synthesis (Kim et al., J Chem Theor Comput 2009, 5, 1931). A protein structure is first decomposed into substructural units, and then each substructural unit is coarse-grained by MC. Once the NMA is implemented to coarse-grained substructural units, normal modes and natural frequencies for each coarse-grained substructural unit are assembled by using geometric constraints to provide the normal modes and natural frequencies for whole protein structure. It is shown that our coarse-graining method enhances the computational efficiency for analysis of large protein complexes. It is clearly suggested that our coarse-graining method provides the B-factors of 100 large proteins, quantitatively comparable with those obtained from original NMA, with computational efficiency. Moreover, the collective behaviors and/or the correlated motions for model proteins are well delineated by our suggested coarse-grained models, quantitatively comparable with those computed from original NMA. It is implied that our coarse-grained method enables the computationally efficient studies on conformational dynamics of large protein complex.

  7. Understanding the group dynamics and success of teams

    Science.gov (United States)

    Klug, Michael; Bagrow, James P.

    2016-01-01

    Complex problems often require coordinated group effort and can consume significant resources, yet our understanding of how teams form and succeed has been limited by a lack of large-scale, quantitative data. We analyse activity traces and success levels for approximately 150 000 self-organized, online team projects. While larger teams tend to be more successful, workload is highly focused across the team, with only a few members performing most work. We find that highly successful teams are significantly more focused than average teams of the same size, that their members have worked on more diverse sets of projects, and the members of highly successful teams are more likely to be core members or ‘leads’ of other teams. The relations between team success and size, focus and especially team experience cannot be explained by confounding factors such as team age, external contributions from non-team members, nor by group mechanisms such as social loafing. Taken together, these features point to organizational principles that may maximize the success of collaborative endeavours. PMID:27152217

  8. Characterization of Bitumen Micro-Mechanical Behaviors Using AFM, Phase Dynamics Theory and MD Simulation

    Directory of Open Access Journals (Sweden)

    Yue Hou

    2017-02-01

    Full Text Available Fundamental understanding of micro-mechanical behaviors in bitumen, including phase separation, micro-friction, micro-abrasion, etc., can help the pavement engineers better understand the bitumen mechanical performances at macroscale. Recent researches show that the microstructure evolution in bitumen will directly affect its surface structure and micro-mechanical performance. In this study, the bitumen microstructure and micro-mechanical behaviors are studied using Atomic Force Microscopy (AFM experiments, Phase Dynamics Theory and Molecular Dynamics (MD Simulation. The AFM experiment results show that different phase-structure will occur at the surface of the bitumen samples under certain thermodynamic conditions at microscale. The phenomenon can be explained using the phase dynamics theory, where the effects of stability parameter and temperature on bitumen microstructure and micro-mechanical behavior are studied combined with MD Simulation. Simulation results show that the saturates phase, in contrast to the naphthene aromatics phase, plays a major role in bitumen micro-mechanical behavior. A high stress zone occurs at the interface between the saturates phase and the naphthene aromatics phase, which may form discontinuities that further affect the bitumen frictional performance.

  9. Dynamic behavior of hybrid sodium bearings. Theoretical and experimental studies

    International Nuclear Information System (INIS)

    Guidez, J.; Juignet, N.; Queval, M.

    1981-08-01

    The primary sodium pump shaft lower section of a fast breeder reactor is guided by a hydrostatic sodium bearing. This recess type bearing is supplied via orifices restrictors. Sodium is sampled at hight pressure at the diffuser outlet and is then centrifuged towards the orifices restrictors. Bearing stiffness and damping data is essential for the study of rotor dynamic behavior. Two points in particular may then be studied: - calculation of rotor instability ranges and critical speeds, - dynamic behavior of the rotor in the event of an earthquake. As regards the bearing design, the problem is to obtain the pressure fields in the liquid film. The integration of these pressure fields will then give the stiffness coefficients. The damping coefficients can then be obtained by the same calculation after slight displacement. The Reynolds equation can be used to study the liquid film (under any conditions for the turbulent and inertia effects). Then the computer code DELPAL is explained that solves the modified Reynolds equation using a finite element method. The presentation of tests conducted in 1981 on the Super-Phenix 1 full scall bearing (diameter 850 mm) in water is made. In conclusion this paper describes a method for calculating the stiffness and damping matrices of a hydrostatic bearing using the DELPAL calculation code and shows the loop of behavior tests on a bearing with sinusoidal excitation. The results, obtained by calculation and by testing, are indispensable when calculating the dynamic behavior of the shaft line

  10. Dynamic Behavior of Spicules Inferred from Perpendicular Velocity Components

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Rahul; Verth, Gary; Erdélyi, Robertus [Solar Physics and Space Plasma Research Centre, University of Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH (United Kingdom)

    2017-05-10

    Understanding the dynamic behavior of spicules, e.g., in terms of magnetohydrodynamic (MHD) wave mode(s), is key to unveiling their role in energy and mass transfer from the photosphere to corona. The transverse, torsional, and field-aligned motions of spicules have previously been observed in imaging spectroscopy and analyzed separately for embedded wave-mode identification. Similarities in the Doppler signatures of spicular structures for both kink and torsional Alfvén wave modes have led to the misinterpretation of the dominant wave mode in these structures and is a subject of debate. Here, we aim to combine line- of-sight (LOS) and plane-of-sky (POS) velocity components using the high spatial/temporal resolution H α imaging-spectroscopy data from the CRisp Imaging SpectroPolarimeter based at the Swedish Solar Telescope to achieve better insight into the underlying nature of these motions as a whole. The resultant three-dimensional velocity vectors and the other derived quantities (e.g., magnetic pressure perturbations) are used to identify the MHD wave mode(s) responsible for the observed spicule motion. We find a number of independent examples where the bulk transverse motion of the spicule is dominant either in the POS or along the LOS. It is shown that the counterstreaming action of the displaced external plasma due to spicular bulk transverse motion has a similar Doppler profile to that of the m = 0 torsional Alfvén wave when this motion is predominantly perpendicular to the LOS. Furthermore, the inferred magnetic pressure perturbations support the kink wave interpretation of observed spicular bulk transverse motion rather than any purely incompressible MHD wave mode, e.g., the m = 0 torsional Alfvén wave.

  11. Synchronized Phasor Data for Analyzing Wind Power Plant Dynamic Behavior and Model Validation

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Y. H.

    2013-01-01

    The U.S. power industry is undertaking several initiatives that will improve the operations of the power grid. One of those is the implementation of 'wide area measurements' using phasor measurement units (PMUs) to dynamically monitor the operations and the status of the network and provide advanced situational awareness and stability assessment. This project seeks to obtain PMU data from wind power plants and grid reference points and develop software tools to analyze and visualize synchrophasor data for the purpose of better understanding wind power plant dynamic behaviors under normal and contingency conditions.

  12. Towards an understanding of the role of the environment in the development of early callous behavior

    Science.gov (United States)

    Waller, Rebecca; Shaw, Daniel S.; Neiderhiser, Jenae M.; Ganiban, Jody M.; Natsuaki, Misaki N.; Reiss, David; Trentacosta, Christopher; Leve, Leslie D.; Hyde, Luke W.

    2015-01-01

    Key to understanding the long-term impact of social inequalities is identifying early behaviors that may signal higher risk for later poor psychosocial outcomes, such as psychopathology. A set of early-emerging characteristics that may signal risk for later externalizing psychopathology is Callous-Unemotional (CU) behavior. CU behavior predict severe and chronic trajectories of externalizing behaviors in youth. However, much research on CU behavior has focused on late childhood and adolescence, with little attention paid to early childhood when preventative interventions may be most effective. In this paper, we summarize our recent work showing that: (1) CU behavior can be identified in early childhood using items from common behavior checklists; (2) CU behavior predicts worse outcomes across early childhood; (3) CU behavior exhibits a distinct nomological network from other early externalizing behaviors; and (4) malleable environmental factors, particularly parenting, may play a role in the development of early CU behaviors. We discuss the challenges of studying contextual contributors to the development of CU behavior in terms of gene-environment correlations and present initial results from work examining CU behavior in an adoption study in which gene-environment correlations are examined in early childhood. We find that parenting is a predictor of early CU behavior even in a sample in which parents are not genetically related to the children. PMID:26291075

  13. Pilot-Induced Oscillations and Human Dynamic Behavior

    Science.gov (United States)

    McRuer, Duane T.

    1995-01-01

    This is an in-depth survey and study of pilot-induced oscillations (PIO's) as interactions between human pilot and vehicle dynamics; it includes a broad and comprehensive theory of PIO's. A historical perspective provides examples of the diversity of PIO's in terms of control axes and oscillation frequencies. The constituents involved in PIO phenomena, including effective aircraft dynamics, human pilot dynamic behavior patterns, and triggering precursor events, are examined in detail as the structural elements interacting to produce severe pilot-induced oscillations. The great diversity of human pilot response patterns, excessive lags and/or inappropriate gain in effective aircraft dynamics, and transitions in either the human or effective aircraft dynamics are among the key sources implicated as factors in severe PIO's. The great variety of interactions which may result in severe PIO's is illustrated by examples drawn from famous PIO's. These are generalized under a pilot-behavior-theory-based set of categories proposed as a classification scheme pertinent to a theory of PIO's. Finally, a series of interim prescriptions to avoid PIO is provided.

  14. Dynamic behavior of a social model for opinion formation

    Science.gov (United States)

    Bordogna, Clelia M.; Albano, Ezequiel V.

    2007-12-01

    The dynamic behavior of a social group influenced by both a strong leader and the mass media, which is modeled according to the social impact theory, is studied under two situations: (i) The strong leader changes his/her state of opinion periodically while the mass media are not considered. In this case, the leader is capable of driving the group between a dynamically ordered state with a weak leader-group coupling (high-frequency regime) and a dynamically disordered state where the group follows the opinion of the leader (low-frequency regime). (ii) The mass-media change periodically their message and have to compete with a strong leader that keeps his/her state of opinion unchanged. In this case, the mass media require an amplitude threshold in order to overcome the influence of the leader and drive the system into a dynamically disordered state. The dynamic behavior characteristic of the studied social opinion model shares many features of physical systems that are relevant in the fields of statistical mechanics and condensed matter.

  15. Dynamic behavior of homogeneous and heterogeneous LMFBR core-design concepts

    International Nuclear Information System (INIS)

    Chang, Y.I.; Henryson, H. II; Orechwa, Y.; Su, S.F.; Greenman, G.; Blomquist, R.

    1981-01-01

    The emphasis is placed on obtaining an understanding of the inherent difference between homogeneous and heterogeneous core configurations regarding neutronic characteristics related to the dynamic behavior. The space-time neutronic and thermal-hydraulic behavior was analyzed in detail for various core configurations by using the FX2-TH, a two-dimensional kinetics code with thermal-hydraulic feedback. In addition, the relationship between the flux tilt and the fundamental-to-first harmonic eigenvalue separation, and the sodium void reactivity in heterogeneous cores were also sutdied

  16. The theory of reasoned action as parallel constraint satisfaction: towards a dynamic computational model of health behavior.

    Directory of Open Access Journals (Sweden)

    Mark G Orr

    Full Text Available The reasoned action approach, although ubiquitous in health behavior theory (e.g., Theory of Reasoned Action/Planned Behavior, does not adequately address two key dynamical aspects of health behavior: learning and the effect of immediate social context (i.e., social influence. To remedy this, we put forth a computational implementation of the Theory of Reasoned Action (TRA using artificial-neural networks. Our model re-conceptualized behavioral intention as arising from a dynamic constraint satisfaction mechanism among a set of beliefs. In two simulations, we show that constraint satisfaction can simultaneously incorporate the effects of past experience (via learning with the effects of immediate social context to yield behavioral intention, i.e., intention is dynamically constructed from both an individual's pre-existing belief structure and the beliefs of others in the individual's social context. In a third simulation, we illustrate the predictive ability of the model with respect to empirically derived behavioral intention. As the first known computational model of health behavior, it represents a significant advance in theory towards understanding the dynamics of health behavior. Furthermore, our approach may inform the development of population-level agent-based models of health behavior that aim to incorporate psychological theory into models of population dynamics.

  17. The theory of reasoned action as parallel constraint satisfaction: towards a dynamic computational model of health behavior.

    Science.gov (United States)

    Orr, Mark G; Thrush, Roxanne; Plaut, David C

    2013-01-01

    The reasoned action approach, although ubiquitous in health behavior theory (e.g., Theory of Reasoned Action/Planned Behavior), does not adequately address two key dynamical aspects of health behavior: learning and the effect of immediate social context (i.e., social influence). To remedy this, we put forth a computational implementation of the Theory of Reasoned Action (TRA) using artificial-neural networks. Our model re-conceptualized behavioral intention as arising from a dynamic constraint satisfaction mechanism among a set of beliefs. In two simulations, we show that constraint satisfaction can simultaneously incorporate the effects of past experience (via learning) with the effects of immediate social context to yield behavioral intention, i.e., intention is dynamically constructed from both an individual's pre-existing belief structure and the beliefs of others in the individual's social context. In a third simulation, we illustrate the predictive ability of the model with respect to empirically derived behavioral intention. As the first known computational model of health behavior, it represents a significant advance in theory towards understanding the dynamics of health behavior. Furthermore, our approach may inform the development of population-level agent-based models of health behavior that aim to incorporate psychological theory into models of population dynamics.

  18. Self-organized complementary joint action: Behavioral dynamics of an interpersonal collision-avoidance task.

    Science.gov (United States)

    Richardson, Michael J; Harrison, Steven J; Kallen, Rachel W; Walton, Ashley; Eiler, Brian A; Saltzman, Elliot; Schmidt, R C

    2015-06-01

    Understanding stable patterns of interpersonal movement coordination is essential to understanding successful social interaction and activity (i.e., joint action). Previous research investigating such coordination has primarily focused on the synchronization of simple rhythmic movements (e.g., finger/forearm oscillations or pendulum swinging). Very few studies, however, have explored the stable patterns of coordination that emerge during task-directed complementary coordination tasks. Thus, the aim of the current study was to investigate and model the behavioral dynamics of a complementary collision-avoidance task. Participant pairs performed a repetitive targeting task in which they moved computer stimuli back and forth between sets of target locations without colliding into each other. The results revealed that pairs quickly converged onto a stable, asymmetric pattern of movement coordination that reflected differential control across participants, with 1 participant adopting a more straight-line movement trajectory between targets, and the other participant adopting a more elliptical trajectory between targets. This asymmetric movement pattern was also characterized by a phase lag between participants and was essential to task success. Coupling directionality analysis and dynamical modeling revealed that this dynamic regime was due to participant-specific differences in the coupling functions that defined the task-dynamics of participant pairs. Collectively, the current findings provide evidence that the dynamical coordination processes previously identified to underlie simple motor synchronization can also support more complex, goal-directed, joint action behavior, and can participate the spontaneous emergence of complementary joint action roles. (c) 2015 APA, all rights reserved).

  19. Dynamic use of geoscience information to develop scientific understanding for a nuclear waste repository

    International Nuclear Information System (INIS)

    Cook, N.G.W.; Tsang, C.F.

    1990-01-01

    This paper discusses the development and safety evaluation of a nuclear waste geologic repository. Scientific understanding dependent upon information from a number of geoscience disciplines is described. A discussion is given on the dynamic use of the information through the different stages. The authors point out the need for abstracting, deriving and updating a quantitative spatial and process model (QSPM) to develop a scientific understanding of site responses as a crucial element in the dynamic procedure

  20. Using the Theory of Planned Behavior to Understand Cervical Cancer Screening among Latinas

    Science.gov (United States)

    Roncancio, Angelica M.; Ward, Kristy K.; Sanchez, Ingrid A.; Cano, Miguel A.; Byrd, Theresa L.; Vernon, Sally W.; Fernandez-Esquer, Maria Eugenia; Fernandez, Maria E.

    2015-01-01

    To reduce the high incidence of cervical cancer among Latinas in the United States it is important to understand factors that predict screening behavior. The aim of this study was to test the utility of theory of planned behavior in predicting cervical cancer screening among a group of Latinas. A sample of Latinas (N = 614) completed a baseline…

  1. Maternal Behavior Modifications during Pretense and Their Long-Term Effects on Toddlers' Understanding of Pretense

    Science.gov (United States)

    Nakamichi, Naoko

    2015-01-01

    Recent studies indicate the need to investigate the sources of toddlers' understanding of another person's pretense. The present study is a cultural and longitudinal extension of the work of Lillard and Witherington (2004), who claimed that mothers modify their behaviors during pretense and that the some of these behavior modifications help their…

  2. Understanding Nature-Related Behaviors among Children through a Theory of Reasoned Action Approach

    Science.gov (United States)

    Gotch, Chad; Hall, Troy

    2004-01-01

    The Theory of Reasoned Action has proven to be a valuable tool for predicting and understanding behavior and, as such, provides a potentially important basis for environmental education program design. This study used a Theory of Reasoned Action approach to examine a unique type of behavior (nature-related activities) and a unique population…

  3. Fractional Lorentz-Dirac Model and Its Dynamical Behaviors

    Science.gov (United States)

    Luo, Shao-Kai; Xu, Yan-Li

    2015-02-01

    In the paper, we construct a new kind of fractional dynamical model, i.e. the fractional Lorentz-Dirac model, and explore dynamical behaviors of the model. We find that the fractional Lorentz-Dirac model possesses Lie algebraic structure and satisfies generalized Poisson conservation law, and then a series of Poisson conserved quantities of the model are given. Further, the relation between conserved quantity and integral invariant of the model is studied, and it is proved that, using the Poisson conserved quantities, we can construct a series of integral invariants of the model. Finally, the stability for the manifolds of equilibrium state of the fractional Lorentz-Dirac model is studied.

  4. Can Dynamic Visualizations Improve Middle School Students' Understanding of Energy in Photosynthesis?

    Science.gov (United States)

    Ryoo, Kihyun; Linn, Marcia C.

    2012-01-01

    Dynamic visualizations have the potential to make abstract scientific phenomena more accessible and visible to students, but they can also be confusing and difficult to comprehend. This research investigates how dynamic visualizations, compared to static illustrations, can support middle school students in developing an integrated understanding of…

  5. The dynamics of behavior in modified dictator games

    Science.gov (United States)

    2017-01-01

    We investigate the dynamics of individual pro-social behavior over time. The dynamics are tested by running the same experiment with the same subjects at several points in time. To exclude learning and reputation building, we employ non-strategic decision tasks and a sequential prisoners-dilemma as a control treatment. In the first wave, pro-social concerns explain a high share of individual decisions. Pro-social decisions decrease over time, however. In the final wave, most decisions can be accounted for by assuming pure selfishness. Stable behavior in the sense that subjects stick to their decisions over time is observed predominantly for purely selfish subjects. We offer two explanation for our results: diminishing experimenter demand effects and moral self-licensing. PMID:28448506

  6. Towards a better understanding of consumer behavior : Marginal Utility as a parameter in Neuromarketing research

    NARCIS (Netherlands)

    Alvino, Letizia; Constantinides, Efthymios; Franco, Massimo

    2017-01-01

    Understanding consumers’ decision-making process is a recurrent goal in Marketing. However, the traditional tools used in marketing, such as surveys, personal interviews and participant observations are often inadequate to analyze and understand human behavior. Since consumer decisions are often

  7. Dynamic behavior of PE-HD pipes grade

    Czech Academy of Sciences Publication Activity Database

    Trnka, Jan; Buchar, Jaroslav; Nezbedová, E.

    2017-01-01

    Roč. 373, č. 1 (2017), č. článku 1700038. ISSN 1022-1360 R&D Projects: GA MŠk(CZ) EF15_003/0000493 Institutional support: RVO:61388998 Keywords : dynamic behavior * PE-HD * split Hopkinson pressure bar test * strain rate Subject RIV: JI - Composite Materials OBOR OECD: Composites (including laminates, reinforced plastics, cermets, combined natural and synthetic fibre fabrics http://onlinelibrary.wiley.com/doi/10.1002/masy.201700038/full

  8. The dynamic behavior of the exohedral transition metal complexes ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 129; Issue 7. The dynamic behavior of the exohedral transition metal complexes of B₄₀ : η⁶- and η⁷-B₄₀Cr(CO) ₃ and Cr(CO) ₃η⁷-B₄η₀-Cr(CO) ₃. NAIWRIT KARMODAK ELUVATHINGAL D JEMMIS. REGULAR ARTICLE Volume 129 Issue 7 July 2017 pp ...

  9. Dynamic Forecasting Behavior by Analysts: Theory and Evidence

    OpenAIRE

    Ajay Subramanian; Jonathan Clarke

    2004-01-01

    We examine the dynamic forecasting behavior of security analysts in response to their prior performance relative to their peers within a continuous time/multi-period framework. Our model predicts a U-shaped relationship between the boldness of an analyst's forecast, that is, the deviation of her forecast from the consensus and her prior relative performance. In other words, analysts who significantly out perform or under perform their peers issue bolder forecasts than intermediate performers....

  10. Dynamic power behavior of a PWR type nuclear reactor

    International Nuclear Information System (INIS)

    Moreira, F.J.

    1984-01-01

    A methodology for the power level evaluation (dynamic behavior) in a Pressurized Water Reactor, during a transient is developed, by solving the point kinetic equation related to the control rod insertion effects and fuel or moderator temperature 'feed-back'. A new version of the thermal-hydraulic code COBRA III P/MIT, is used. In this new version was included, as an option, the methodology developed. (E.G.) [pt

  11. Dynamical behavior of a stochastic SVIR epidemic model with vaccination

    Science.gov (United States)

    Zhang, Xinhong; Jiang, Daqing; Hayat, Tasawar; Ahmad, Bashir

    2017-10-01

    In this paper, we investigate the dynamical behavior of SVIR models in random environments. Firstly, we show that if R0s 1, the disease will be prevail. Moreover, this system admits a unique stationary distribution and it is ergodic when R˜0s > 1. Results show that environmental white noise is helpful for disease control. Secondly, we give sufficient conditions for the existence of nontrivial periodic solutions to stochastic SVIR model with periodic parameters. Finally, numerical simulations validate the analytical results.

  12. Understanding Attitudes and Pro-Environmental Behaviors in a Chilean Community

    Directory of Open Access Journals (Sweden)

    Nicolás C. Bronfman

    2015-10-01

    Full Text Available Environmental protection and restoration are some of the major challenges faced by our society. To address this problem, it is fundamental to understand pro-environmental behaviors in the population, as well as the factors that determine them. There are, however, very few studies conducted in Latin America that are focused in understanding the environmental behavior of its citizens. The main goal of this research was to study the environmental behaviors of a Chilean community and identify the factors that determine them. To that end, a diverse set of environmental behaviors (power and water conservation, environmentally-aware consumer behavior, biodiversity protection, rational automobile use and ecological waste management and sociodemographic and attitudinal factors—based on the VBN model—were evaluated. Survey data was obtained from a statistically representative sample (N = 1537 in Santiago, Chile. Our results suggest that several participants displayed tendencies that favor more responsible environmental behaviors, with high environmental concern, and demonstrating their ample awareness of the consequences of failing to protect the environment. Nevertheless, the highest average scores of environmental behavior were related to low cost behaviors and those that imposed the fewest behavioral restrictions. In global terms, we concluded that the youngest subjects in the lowest socioeconomic group obtained the lowest scores across the pro-environmental behavior spectrum.

  13. Sloshing effect on the dynamic behavior of horizontal cylindrical shells

    International Nuclear Information System (INIS)

    Lakis, A.A.; Bursuc, G.; Toorani, M.H.

    2009-01-01

    The present study investigates the effect of free surface motion of a fluid on the dynamic behavior of thin-walled cylindrical shells. This paper outlines a semi-analytical approach to dynamic analysis of a fluid-filled horizontal cylindrical shell taking into account free surface motion; sloshing. The aim of the method is to provide a general approach that can be used for both analysis and synthesis of fluid/structure interaction problems in horizontal cylindrical shells focusing on the dynamic interaction between a flexible structure and incompressible and inviscid flow. The approach is very general; it allows dynamic analysis of both uniform and non-uniform cylindrical shells and considers the fluid forces and includes the sloshing effect exerted on the structure. The hybrid method developed in this work incorporates a combination of the classic finite element approach and thin shell theory to determine the specific displacement functions. Mass and stiffness matrices of the shell are determined by precise analytical integration. A potential function is applied to develop the dynamic pressure due to the fluid. The kinetic and potential energies are evaluated for a range of fluid heights to find the influence of the fluid on the dynamic responses of the structure. The influence of physical and geometrical parameters on the fluid-structure system has been considered in the numerical solutions. When these results are compared with corresponding results available in the literature, both theoretical and experimental, very good agreement is obtained.

  14. Soft-assembled multilevel dynamics of tactical behaviors in soccer

    Directory of Open Access Journals (Sweden)

    Angel Ric

    2016-10-01

    Full Text Available This study aimed to identify the tactical patterns and the timescales of variables during a soccer match, allowing understanding the multilevel organization of tactical behaviors, and to determine the similarity of patterns performed by different groups of teammates during the first and second halves. Positional data from twenty professional male soccer players from the same team were collected using high frequency global positioning systems (5Hz. Twenty-nine categories of tactical behaviors were determined from eight positioning-derived variables creating multivariate binary (Boolean time-series matrices. Hierarchical principal component analysis was used to identify the multilevel structure of tactical behaviors. The sequential reduction of each set level of principal components revealed a sole principal component as the slowest collective variable, forming the global basin of attraction of tactical patterns during each half of the match. In addition, the mean dwell time of each positioning-derived variable helped to understand the multilevel organization of collective tactical behavior during a soccer match. This approach warrants further investigations to analyze the influence of task constraints on the emergence of tactical behavior. Furthermore, principal component analysis can help coaches to design representative training tasks according to those tactical patterns captured during match competitions and to compare them depending on situational variables.

  15. Long-term analysis of Zostera noltei: A retrospective approach for understanding seagrasses' dynamics.

    Science.gov (United States)

    Calleja, Felipe; Galván, Cristina; Silió-Calzada, Ana; Juanes, José A; Ondiviela, Bárbara

    2017-09-01

    Long-term studies are necessary to establish trends and to understand seagrasses' spatial and temporal dynamic. Nevertheless, this type of research is scarce, as the required databases are often unavailable. The objectives of this study are to create a method for mapping the seagrass Zostera noltei using remote sensing techniques, and to apply it to the characterization of the meadows' extension trend and the potential drivers of change. A time series was created using a novel method based on remote sensing techniques that proved to be adequate for mapping the seagrass in the emerged intertidal. The meadows seem to have a decreasing trend between 1984 and the early 2000s, followed by an increasing tendency that represents a recovery in the extension area of the species. This 30-year analysis demonstrated the Z. noltei's recovery in the study site, similar to that in other estuaries nearby and contrary to the worldwide decreasing behavior of seagrasses. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. A reduced complexity discrete particle model for understanding the sediment dynamics of steep upland river confluences

    Science.gov (United States)

    Tancock, M. J.; Lane, S. N.; Hardy, R. J.

    2012-12-01

    There has been a significant amount of research conducted in order to understand the flow fields at natural river confluences. Much of this has been made possible due to advances in the use of Computational Fluid Dynamics (CFD). However, much of this research has been conducted on river confluences with negligible water surface slopes and any understanding of the sediment dynamics is largely implied from the flow fields. Therefore, a key challenge is to understand the flow and sediment dynamics of steep river confluences with dynamic boundaries. Two numerical modelling developments are presented which together are capable of increasing our understanding of the sediment dynamics of steep river confluences. The first is the application of a Height-of-Liquid (HOL) model within a CFD framework to explicitly solve the water surface elevation. This is a time-dependent, multiphase treatment of the fluid dynamics which solves for the change in volume of water and air in each vertical column of the mesh. The second is the development of a reduced complexity discrete particle transport model which uses the change in momentum on a spherical particle to predict the transport paths through the flow field determined from CFD simulations. The performance of the two models is tested using field data from a series of highly dynamic, steep gravel-bed confluences on a braidplain of the Borgne d'Arolla, Switzerland. The HOL model is validated against the water surface elevation and flow velocity data and is demonstrated to provide a reliable representation of the flow field in fast-flowing, supercritical flows. In order to validate the discrete particle model, individual particles were tracked using electronic tacheometry. The model is demonstrated to accurately represent the particle tracks obtained in the field and provides a new methodology to understand the dynamic morphology of braid plains.

  17. On Understanding the Human Nature of Good and Bad Behavior in Business: A Behavioral Ethics Approach

    NARCIS (Netherlands)

    D. de Cremer (David)

    2009-01-01

    textabstractThe numerous scandals in business, such as those at AIG, Tyco, WorldCom, Enron and Ahold, have made all of us concerned about the emergence of unethical and irresponsible behavior in organizations. Such widespread corruption in business and politics has, as result, prompted a growth of

  18. Dynamical behavior and Jacobi stability analysis of wound strings

    Energy Technology Data Exchange (ETDEWEB)

    Lake, Matthew J. [Naresuan University, The Institute for Fundamental Study, ' ' The Tah Poe Academia Institute' ' , Phitsanulok (Thailand); Thailand Center of Excellence in Physics, Ministry of Education, Bangkok (Thailand); Harko, Tiberiu [Babes-Bolyai University, Department of Physics, Cluj-Napoca (Romania); University College London, Department of Mathematics, London (United Kingdom)

    2016-06-15

    We numerically solve the equations of motion (EOM) for two models of circular cosmic string loops with windings in a simply connected internal space. Since the windings cannot be topologically stabilized, stability must be achieved (if at all) dynamically. As toy models for realistic compactifications, we consider windings on a small section of R{sup 2}, which is valid as an approximation to any simply connected internal manifold if the winding radius is sufficiently small, and windings on an S{sup 2} of constant radius R. We then use Kosambi-Cartan-Chern (KCC) theory to analyze the Jacobi stability of the string equations and determine bounds on the physical parameters that ensure dynamical stability of the windings. We find that, for the same initial conditions, the curvature and topology of the internal space have nontrivial effects on the microscopic behavior of the string in the higher dimensions, but that the macroscopic behavior is remarkably insensitive to the details of the motion in the compact space. This suggests that higher-dimensional signatures may be extremely difficult to detect in the effective (3+1)-dimensional dynamics of strings compactified on an internal space, even if configurations with nontrivial windings persist over long time periods. (orig.)

  19. Understanding multiple levels of norms about teen pregnancy and their relationships to teens’ sexual behaviors

    OpenAIRE

    Mollborn, Stefanie; Domingue, Benjamin W.; Boardman, Jason D.

    2014-01-01

    Researchers seeking to understand teen sexual behaviors often turn to age norms, but they are difficult to measure quantitatively. Previous work has usually inferred norms from behavioral patterns or measured group-level norms at the individual level, ignoring multiple reference groups. Capitalizing on the multilevel design of the Add Health survey, we measure teen pregnancy norms perceived by teenagers, as well as average norms at the school and peer network levels. School norms predict boys...

  20. An investigation of the static and dynamic behavior of electrically actuated rectangular microplates

    KAUST Repository

    Saghir, S.

    2016-06-16

    We present an investigation of the static and dynamic behavior of the nonlinear von-Karman plates when actuated by the nonlinear electrostatic forces. The investigation is based on a reduced order model developed using the Galerkin method, which rely on modeshapes and in-plane shape functions extracted using a finite element method. In this study, a fully clamped microplate is considered. We investigate the static behavior and the effect of different non-dimensional design parameters. The static results are validated by comparison with the results calculated by a finite element model. The forced-vibration response of the plate is then investigated when the plate is excited by a harmonic AC load superimposed to a DC load. The dynamic behavior is examined near the primary and secondary (superharmonic and subharmonic) resonances. The microplate shows a strong hardening behavior due to the cubic nonlinearity of mid-plane stretching. However, the behavior switches to softening as the DC load is increased. Finally, near-square plates are studied to understand the effect of geometric imperfections of microplates.

  1. Enhancements for a Dynamic Data Warehousing and Mining System for Large-Scale Human Social Cultural Behavioral (HSBC) Data

    Science.gov (United States)

    2016-09-26

    System for Large-Scale Human Social Cultural Behavioral (HSBC) Data Final Report Reporting Period: March 22, 2016 – September 18, 2016...Enhancements for a Dynamic Data Warehousing and Mining System for N00014-16-P-3014 Large-Scale Human Social Cultural Behavioral (HSBC) Data 5b. GRANT NUMBER...decision makers and field personnel to better understand and address unexpected crises. By using graph analytics at large-scales, users will be able to

  2. The Crucible simulation: Behavioral simulation improves clinical leadership skills and understanding of complex health policy change.

    Science.gov (United States)

    Cohen, Daniel; Vlaev, Ivo; McMahon, Laurie; Harvey, Sarah; Mitchell, Andy; Borovoi, Leah; Darzi, Ara

    2017-05-11

    The Health and Social Care Act 2012 represents the most complex National Health Service reforms in history. High-quality clinical leadership is important for successful implementation of health service reform. However, little is known about the effectiveness of current leadership training. This study describes the use of a behavioral simulation to improve the knowledge and leadership of a cohort of medical doctors expected to take leadership roles in the National Health Service. A day-long behavioral simulation (The Crucible) was developed and run based on a fictitious but realistic health economy. Participants completed pre- and postsimulation questionnaires generating qualitative and quantitative data. Leadership skills, knowledge, and behavior change processes described by the "theory of planned behavior" were self-assessed pre- and postsimulation. Sixty-nine medical doctors attended. Participants deemed the simulation immersive and relevant. Significant improvements were shown in perceived knowledge, capability, attitudes, subjective norms, intentions, and leadership competency following the program. Nearly one third of participants reported that they had implemented knowledge and skills from the simulation into practice within 4 weeks. This study systematically demonstrates the effectiveness of behavioral simulation for clinical management training and understanding of health policy reform. Potential future uses and strategies for analysis are discussed. High-quality care requires understanding of health systems and strong leadership. Policymakers should consider the use of behavioral simulation to improve understanding of health service reform and development of leadership skills in clinicians, who readily adopt skills from simulation into everyday practice.

  3. The dynamic interaction of personal norms and environment-friendly buying behavior: A panel study

    DEFF Research Database (Denmark)

    Thøgersen, John; Ølander, Folke

    2006-01-01

    A deeper understanding of the attitude-norm-behavior relationship in the environmental field can be obtained by analyzing the dynamic interaction over time between relevant attitudinal variables and specific behaviors of interest. This article is based on a panel survey with a random sample...... of about 1,500 Danes interviewed up to 3 times in 1998 to 2000, regarding their purchase of organic food products. The panel analysis reveals that the stronger are consumers' personal norms about buying organic food products and the less they perceive organic products as expensive, the greater...... the likelihood that they change their purchase patterns in favor of organic products. Furthermore, one can observe significant cross-lagged paths from past behavior to belief and norm variables....

  4. Dynamic Mechanical Behaviors of 6082-T6 Aluminum Alloy

    Directory of Open Access Journals (Sweden)

    Peng Yibo

    2013-01-01

    Full Text Available The structural components of high speed trains are usually made of aluminum alloys, for example, 6082. The dynamic mechanical behavior of the material is one of key factors considered in structural design and safety assessment. In this paper, dynamic mechanical experiments were conducted with strain rate ranging from 0.001 s−1 to 100 s−1 using Instron tensile testing machine. The true stress-strain curves were fitted based on experimental data. Johnson-Cook model of 6082-T6 aluminum alloy was built to investigate the effect of strain and strain rate on flow stress. It has shown that the flow stress was sensitive to the strain rate. Yield strength and tensile strength increased with a high strain rate, which showed strain rate effect to some extent. Fracture analysis was carried out by using Backscattered Electron imaging (BSE. As strain rate increased, more precipitates were generated in fracture.

  5. Characterization of the dynamic mechanical behavior of magneto - elastomers

    International Nuclear Information System (INIS)

    Schrittesser, B; Major, Z; Filipcsei, G

    2009-01-01

    Due to their magnetic field dependent mechanical response, polymeric materials filled with magnetic particles have become of major practical and theoretical interest. the dynamic-mechanical behavior of polydimethylsiloxane rubber filled with ferro-oxide with and without magnetic field has been investigated in this study. Specimens with different hardness and with two distinct orientations of the fillers (isotropy, anisotropy) were prepared. Dynamic mechanical analysis experiments were performed to determine the storage and loss modulus over a wide amplitude and frequency range with and without external magnetic field. In order to characterize the influence of the ferro-oxide filler particles, a permanent magnetic field to the specimen grips has been attached. The complex-, storage- and loss modulus and the loss factor values were determined. Finally, to compare the isotropic and anisotropic materials a magnetic stiffening factor (MSF) was defined and applied.

  6. The modeling of the dynamic behavior of an unsymmetrical rotor

    Science.gov (United States)

    Pǎrǎuşanu, Ioan; Gheorghiu, Horia; Petre, Cristian; Jiga, Gabriel; Crişan, Nicoleta

    2018-02-01

    The purpose of this article is to present the modeling of the dynamic behaviour of unsymmetrical rotors in relatively simple quantitative terms. Numerical simulations show that the shaft orthotropy produces a peak of resonant vibration about half the regular critical speed and, for small damping, a range of possible unstable behavior between the two critical speeds. Rotors having the shaft and/or the disks with unequal diametral moments of inertia (e.g., two-bladed small airplane propellers, wind turbines and fans) are dynamically unstable above a certain speed and some of these may return to a stable condition at a sufficiently high speed, depending on the particular magnitudes of the gyroscopic coupling and the inertia inequality.

  7. Fluid-dynamic behavior of flaxseed fluidized and spouted bed

    Directory of Open Access Journals (Sweden)

    Elza Brandão Santana

    2017-09-01

    Full Text Available ABSTRACT: Processing of particles in a moving bed, such as a fluidized bed or a spouting bed, is commonly used in the operations of drying, coating, and granulation of particulate systems. This process has applications in the chemical, pharmaceutical and, presently, agronomical industries, especially for seed treatment/coating. This research aimed to analyze the fluid-dynamic behavior of fluidized and spouting beds with different air temperatures and loads of flaxseeds (Linum usitatissimum L., with estimates of the fluid-dynamic parameters correlated to each process. The parameters were compared with the values obtained from classical correlations in the literature, with indications of associated percentages of deviation. Influence of fluid dynamics on the physiological quality of seeds was assessed by germination tests and the germination speed index. An analysis of the results indicated that seed processing was adequate for processing in dynamically active beds; however, temperatures above 50ºC in both beds caused significant reductions in the physiological quality of the seeds. Processing in a fluidized bed presented a smaller reduction of the physiological properties of the flaxseed.

  8. Dynamic Simulation of Community Crime and Crime-Reporting Behavior

    Science.gov (United States)

    Yonas, Michael A.; Borrebach, Jeffrey D.; Burke, Jessica G.; Brown, Shawn T.; Philp, Katherine D.; Burke, Donald S.; Grefenstette, John J.

    An agent-based model was developed to explore the effectiveness of possible interventions to reduce neighborhood crime and violence. Both offenders and non-offenders (or citizens) were modeled as agents living in neighborhoods, with a set of rules controlling changes in behavior based on individual experience. Offenders may become more or less inclined to actively commit criminal offenses, depending on the behavior of the neighborhood residents and other nearby offenders, and on their arrest experience. In turn, citizens may become more or less inclined to report crimes, based on the observed prevalence of criminal activity within their neighborhood. This paper describes the basic design and dynamics of the model, and how such models might be used to investigate practical crime intervention programs.

  9. A study of dynamical behavior of space environment

    Science.gov (United States)

    Wu, S. T.

    1974-01-01

    Studies have covered a wide range of problems in the space environment, such as the problems of the dynamical behavior of the thermosphere, hydromagnetic wave propagation in the ionosphere, and interplanetary space environment. The theories used to analyze these problems range from a continuum theory of magnetohydrodynamics to the kinetic theory of free molecular flow. This is because the problems encountered covered the entire range of the Knudsen number (i.e., the ratio of mean free path to the characteristic length). Significant results are summarized.

  10. A Visual Analytics Approach for Detecting and Understanding Anomalous Resident Behaviors in Smart Healthcare

    Directory of Open Access Journals (Sweden)

    Zhifang Liao

    2017-03-01

    Full Text Available With the development of science and technology, it is possible to analyze residents’ daily behaviors for the purpose of smart healthcare in the smart home environment. Many researchers have begun to detect residents’ anomalous behaviors and assess their physical condition, but these approaches used by the researchers are often caught in plight caused by a lack of ground truth, one-sided analysis of behavior, and difficulty of understanding behaviors. In this paper, we put forward a smart home visual analysis system (SHVis to help analysts detect and comprehend unusual behaviors of residents, and predict the health information intelligently. Firstly, the system classifies daily activities recorded by sensor devices in smart home environment into different categories, and discovers unusual behavior patterns of residents living in this environment by using various characteristics extracted from those activities and appropriate unsupervised anomaly detection algorithm. Secondly, on the basis of figuring out the residents’ anomaly degree of every date, we explore the daily behavior patterns and details with the help of several visualization views, and compare and analyze residents’ activities of various dates to find the reasons why residents act unusually. In the case study of this paper, we analyze residents’ behaviors that happened over two months and find unusual indoor behaviors and give health advice to the residents.

  11. Meta-Analysis of the Reasoned Action Approach (RAA) to Understanding Health Behaviors.

    Science.gov (United States)

    McEachan, Rosemary; Taylor, Natalie; Harrison, Reema; Lawton, Rebecca; Gardner, Peter; Conner, Mark

    2016-08-01

    Reasoned action approach (RAA) includes subcomponents of attitude (experiential/instrumental), perceived norm (injunctive/descriptive), and perceived behavioral control (capacity/autonomy) to predict intention and behavior. To provide a meta-analysis of the RAA for health behaviors focusing on comparing the pairs of RAA subcomponents and differences between health protection and health-risk behaviors. The present research reports a meta-analysis of correlational tests of RAA subcomponents, examination of moderators, and combined effects of subcomponents on intention and behavior. Regressions were used to predict intention and behavior based on data from studies measuring all variables. Capacity and experiential attitude had large, and other constructs had small-medium-sized correlations with intention; all constructs except autonomy were significant independent predictors of intention in regressions. Intention, capacity, and experiential attitude had medium-large, and other constructs had small-medium-sized correlations with behavior; intention, capacity, experiential attitude, and descriptive norm were significant independent predictors of behavior in regressions. The RAA subcomponents have utility in predicting and understanding health behaviors.

  12. Dynamic behavior of district heating systems. 1. Report

    International Nuclear Information System (INIS)

    Kunz, J.

    1993-01-01

    In this study a comprehensive model simulating the dynamic behavior of an entire district heating system has been developed. The model consists of four partial models, namely a model of the hydraulic behavior of a heat distribution network, another model of the thermal behavior of this network, a model of the heat generation plants and one of the heat consumers connected to the system. For the hydraulic simulation of the distribution network, a classical steady state approach has proved to be sufficient. The evolution of the temperatures in the network is given by the equation of transport. A numerical resolution scheme, which is adapted to the special case of a heat distribution network was developed for this equation. The model developed for the heating plant is simple but it is sufficiently detailed to determine the operation of its elements. A more complex model would take much more calculation time, but with such a simple model, it is possible to include it in the global model of the entire system. Each heat consumer is represented by a simple one cell model. The difficulty in such an approach is to determine the characteristics of each building in a simple manner. A classification, which allows to find the essential parameters from few and easily available data, has been defined. This model is not sufficiently accurate to calculate the thermal behavior of one specific building but it allows to determine the average dynamic evolution of the heat demand for a set of buildings with a good precision.The developed models have been programmed on a personal computer and the entire district heating network of the city of Lausanne has been simulated with this calculation code. Measurements have been taken on this network and the comparison with calculated results has allowed to calibrate the model. The comparison of measurements and calculations shows, that each part of the system is simulated realistically by the proposed model. (author) figs., tabs., refs

  13. Microscopic dynamics in simple liquids: a clue to understanding the basic thermodynamics of the liquid state

    International Nuclear Information System (INIS)

    Cabrillo, C; Bermejo, F J; Maira-Vidal, A; Fernandez-Perea, R; Bennington, S M; Martin, D

    2004-01-01

    The advent of inelastic x-ray scattering techniques has prompted a reawakened interest in the dynamics of simple liquids. Such studies are often carried out using simplified models to account for the stochastic dynamics that give rise to quasielastic scattering. The vibrational and diffusive dynamics of molten potassium are studied here by an experiment using neutron scattering and are shown to provide some clues to understand the basic thermodynamics of the liquid state. The findings reported here suggest ways in which the true complementarity of neutron and x-ray scattering may be profitably exploited

  14. Using system dynamics modeling to understand the impact of social change initiatives.

    Science.gov (United States)

    Hirsch, Gary B; Levine, Ralph; Miller, Robin Lin

    2007-06-01

    Community psychologists have a long history of interest in understanding social systems and how to bring about enduring positive change in these systems. However, the methods that community psychologists use to anticipate and evaluate the changes that result from system change efforts are less well developed. In the current paper, we introduce readers to system dynamics modeling, an action research approach to studying complex systems and the consequences of system change. We illustrate this approach by describing a system dynamics model of educational reform. We provide readers with an introduction to system dynamics modeling, as well as describe the strengths and limitations of the approach for application to community psychology.

  15. Interpretation of dynamic tensile behavior by austenite stability in ferrite-austenite duplex lightweight steels.

    Science.gov (United States)

    Park, Jaeyeong; Jo, Min Cheol; Jeong, Hyeok Jae; Sohn, Seok Su; Kwak, Jai-Hyun; Kim, Hyoung Seop; Lee, Sunghak

    2017-11-16

    Phenomena occurring in duplex lightweight steels under dynamic loading are hardly investigated, although its understanding is essentially needed in applications of automotive steels. In this study, quasi-static and dynamic tensile properties of duplex lightweight steels were investigated by focusing on how TRIP and TWIP mechanisms were varied under the quasi-static and dynamic loading conditions. As the annealing temperature increased, the grain size and volume fraction of austenite increased, thereby gradually decreasing austenite stability. The strain-hardening rate curves displayed a multiple-stage strain-hardening behavior, which was closely related with deformation mechanisms. Under the dynamic loading, the temperature rise due to adiabatic heating raised the austenite stability, which resulted in the reduction in the TRIP amount. Though the 950 °C-annealed specimen having the lowest austenite stability showed the very low ductility and strength under the quasi-static loading, it exhibited the tensile elongation up to 54% as well as high strain-hardening rate and tensile strength (1038 MPa) due to appropriate austenite stability under dynamic loading. Since dynamic properties of the present duplex lightweight steels show the excellent strength-ductility combination as well as continuously high strain hardening, they can be sufficiently applied to automotive steel sheets demanded for stronger vehicle bodies and safety enhancement.

  16. Understanding Knowledge Sharing Behavior: An Examination of the Extended Model of Theory of Planned Behavior

    Directory of Open Access Journals (Sweden)

    Sabrina O. Sihombing

    2011-03-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 Knowledge is recognized as one valuable asset for many organizations. Thus, knowledge-sharing is one of important activities in many organizations, including university. Knowledge sharing is defined as activities of transferring or disseminating organizationally relevant information, ideas, suggestions, and expertise with one another. This research applied Christian values as a moderating variable in the framework of theory of planned behavior. The aims of this research to assess applicability of the theory of planned behavior to predict knowledge sharing and to examine the effects of Christian values in the relationship between attitude and intention to share knowledge. A self-administered questionnaire was used to collect the data for this study. The data was then analyzed using structural equation modeling. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

  17. The Psychology of Isolated and Confined Environments: Understanding Human Behavior in Antarctica.

    Science.gov (United States)

    Palinkas, Lawrence A.

    2003-01-01

    Reviews lessons learned from research in Antarctica with relevance to understanding human behavior in other isolated and confined environments. Outlines four distinct characteristics of psychosocial adaptation to such environments and discusses some of the benefits for individuals seeking challenging experiences. (Contains references.) (SLD)

  18. A neurogenetics approach to understanding individual differences in brain, behavior, and risk for psychopathology.

    Science.gov (United States)

    Bogdan, R; Hyde, L W; Hariri, A R

    2013-03-01

    Neurogenetics research has begun to advance our understanding of how genetic variation gives rise to individual differences in brain function, which, in turn, shapes behavior and risk for psychopathology. Despite these advancements, neurogenetics research is currently confronted by three major challenges: (1) conducting research on individual variables with small effects, (2) absence of detailed mechanisms, and (3) a need to translate findings toward greater clinical relevance. In this review, we showcase techniques and developments that address these challenges and highlight the benefits of a neurogenetics approach to understanding brain, behavior and psychopathology. To address the challenge of small effects, we explore approaches including incorporating the environment, modeling epistatic relationships and using multilocus profiles. To address the challenge of mechanism, we explore how non-human animal research, epigenetics research and genome-wide association studies can inform our mechanistic understanding of behaviorally relevant brain function. Finally, to address the challenge of clinical relevance, we examine how neurogenetics research can identify novel therapeutic targets and for whom treatments work best. By addressing these challenges, neurogenetics research is poised to exponentially increase our understanding of how genetic variation interacts with the environment to shape the brain, behavior and risk for psychopathology.

  19. Bridging Models and Business: Understanding heterogeneity in hidden drivers of customer purchase behavior

    NARCIS (Netherlands)

    E. Korkmaz (Evsen)

    2014-01-01

    markdownabstract__Abstract__ Recent years have seen many advances in quantitative models in the marketing literature. Even though these advances enable model building for a better understanding of customer purchase behavior and customer heterogeneity such that firms develop optimal targeting and

  20. An Integrative Model for Understanding Team Organizational Citizenship Behavior: Its Antecedents and Consequences for Educational Teams

    Science.gov (United States)

    Somech, Anit; Khotaba, Soha

    2017-01-01

    Purpose: The purpose of this paper is to use a model to broaden the understanding of the organizational citizenship behavior (OCB) phenomenon in educational teams and examines team OCB's mediating role in the relation of the contextual variables of team justice climate (distributive justice, procedural justice, interpersonal justice) to team…

  1. Understanding multiple levels of norms about teen pregnancy and their relationships to teens’ sexual behaviors

    Science.gov (United States)

    Mollborn, Stefanie; Domingue, Benjamin W.; Boardman, Jason D.

    2014-01-01

    Researchers seeking to understand teen sexual behaviors often turn to age norms, but they are difficult to measure quantitatively. Previous work has usually inferred norms from behavioral patterns or measured group-level norms at the individual level, ignoring multiple reference groups. Capitalizing on the multilevel design of the Add Health survey, we measure teen pregnancy norms perceived by teenagers, as well as average norms at the school and peer network levels. School norms predict boys’ perceived norms, while peer network norms predict girls’ perceived norms. Peer network and individually perceived norms against teen pregnancy independently and negatively predict teens’ likelihood of sexual intercourse. Perceived norms against pregnancy predict increased likelihood of contraception among sexually experienced girls, but sexually experienced boys’ contraceptive behavior is more complicated: When both the boy and his peers or school have stronger norms against teen pregnancy he is more likely to contracept, and in the absence of school or peer norms against pregnancy, boys who are embarrassed are less likely to contracept. We conclude that: (1) patterns of behavior cannot adequately operationalize teen pregnancy norms, (2) norms are not simply linked to behaviors through individual perceptions, and (3) norms at different levels can operate independently of each other, interactively, or in opposition. This evidence creates space for conceptualizations of agency, conflict, and change that can lead to progress in understanding age norms and sexual behaviors. PMID:25104920

  2. Understanding multiple levels of norms about teen pregnancy and their relationships to teens' sexual behaviors.

    Science.gov (United States)

    Mollborn, Stefanie; Domingue, Benjamin W; Boardman, Jason D

    2014-06-01

    Researchers seeking to understand teen sexual behaviors often turn to age norms, but they are difficult to measure quantitatively. Previous work has usually inferred norms from behavioral patterns or measured group-level norms at the individual level, ignoring multiple reference groups. Capitalizing on the multilevel design of the Add Health survey, we measure teen pregnancy norms perceived by teenagers, as well as average norms at the school and peer network levels. School norms predict boys' perceived norms, while peer network norms predict girls' perceived norms. Peer network and individually perceived norms against teen pregnancy independently and negatively predict teens' likelihood of sexual intercourse. Perceived norms against pregnancy predict increased likelihood of contraception among sexually experienced girls, but sexually experienced boys' contraceptive behavior is more complicated: When both the boy and his peers or school have stronger norms against teen pregnancy he is more likely to contracept, and in the absence of school or peer norms against pregnancy, boys who are embarrassed are less likely to contracept. We conclude that: (1) patterns of behavior cannot adequately operationalize teen pregnancy norms, (2) norms are not simply linked to behaviors through individual perceptions, and (3) norms at different levels can operate independently of each other, interactively, or in opposition. This evidence creates space for conceptualizations of agency, conflict, and change that can lead to progress in understanding age norms and sexual behaviors.

  3. Evaluation of seismic behavior of soils under nuclear containment structures via dynamic centrifuge test

    International Nuclear Information System (INIS)

    Ha, Jeong Gon; Kim, Dong-Soo

    2014-01-01

    Highlights: • A series of dynamic centrifuge tests were performed for NPP structure to investigate the soil–foundation-structure interaction with various soil conditions from loose sand to weathered rock. • SFSI phenomena for NPP structure were observed directly using experimental method. • Effect of the soil stiffness and nonlinear characteristics on SFSI was estimated. • There are comparisons of the control motions for seismic design of a NPP structure. • Subsoil condition, earthquake intensity and control motion affected to seismic load. - Abstract: To evaluate the earthquake loads for the seismic design of a nuclear containment structure, it is necessary to consider the soil–foundation-structure interaction (SFSI) due to their interdependent behavior. Especially, understanding the effects of soil stiffness under the structure and the location of control motion to SFSI are very important. Motivated by these requirements, a series of dynamic centrifuge tests were performed with various soil conditions from loose sand to weathered rock (WR), as well as different seismic intensities for the bedrock motion. The different amplification characteristics in peak-accelerations profile and effects of soil-nonlinearity in response spectrum were observed. The dynamic behaviors were compared between surface of free-field and foundation of the structure for the evaluation of the control motion for seismic design. It was found that dynamic centrifuge test has potentials to estimate the seismic load considering SFSI

  4. Computer Assisted Comprehension of Distant Worlds: Understanding Hunger Dynamics in Africa.

    Science.gov (United States)

    Moseley, William G.

    2001-01-01

    Describes a computer program called RiskMap. Explains that after completing an assignment on rural economics and hunger dynamics in Africa, students showed an increased level of understanding and felt that using RiskMap was helpful in learning the material. Includes references. (DAJ)

  5. Biometrics Technology: Understanding Dynamics Influencing Adoption for Control of Identification Deception within Nigeria

    Science.gov (United States)

    Nwatu, Gideon U.

    2011-01-01

    One of the objectives of any government is the establishment of an effective solution to significantly control crime. Identity fraud in Nigeria has generated global attention and negative publicity toward its citizens. The research problem addressed in this study was the lack of understanding of the dynamics that influenced the adoption and…

  6. Dynamic Graphics in Excel for Teaching Statistics: Understanding the Probability Density Function

    Science.gov (United States)

    Coll-Serrano, Vicente; Blasco-Blasco, Olga; Alvarez-Jareno, Jose A.

    2011-01-01

    In this article, we show a dynamic graphic in Excel that is used to introduce an important concept in our subject, Statistics I: the probability density function. This interactive graphic seeks to facilitate conceptual understanding of the main aspects analysed by the learners.

  7. Managing lifelike behavior in a dynamic self-assembled system

    Science.gov (United States)

    Ropp, Chad; Bachelard, Nicolas; Wang, Yuan; Zhang, Xiang

    Self-organization can arise outside of thermodynamic equilibrium in a process of dynamic self-assembly. This is observed in nature, for example in flocking birds, but can also be created artificially with non-living entities. Such dynamic systems often display lifelike properties, including the ability to self-heal and adapt to environmental changes, which arise due to the collective and often complex interactions between the many individual elements. Such interactions are inherently difficult to predict and control, and limit the development of artificial systems. Here, we report a fundamentally new method to manage dynamic self-assembly through the direct external control of collective phenomena. Our system consists of a waveguide filled with mobile scattering particles. These particles spontaneously self-organize when driven by a coherent field, self-heal when mechanically perturbed, and adapt to changes in the drive wavelength. This behavior is governed by particle interactions that are completely mediated by coherent wave scattering. Compared to hydrodynamic interactions which lead to compact ordered structures, our system displays sinusoidal degeneracy and many different steady-state geometries that can be adjusted using the external field.

  8. Facebook tells me so: applying the theory of planned behavior to understand partner-monitoring behavior on Facebook.

    Science.gov (United States)

    Darvell, Millie J; Walsh, Shari P; White, Katherine M

    2011-12-01

    The social networking site (SNS) Facebook is becoming increasingly recognized as a medium through which individuals can investigate and monitor others' activities. However, little is known about whether Facebook monitoring behavior occurs within romantic relationships and, accordingly, the psychological predictors of this behavior. The present study employed an extended theory of planned behavior (TPB) framework including self-esteem, partner trust, and demographic characteristics, to predict frequent Facebook partner-monitoring. Facebook users (N=244) in romantic relationships completed measures assessing the standard TPB constructs (attitude, subjective norm, and perceived behavioral control), additional predictor variables (self-esteem and partner trust), and demographic characteristics (age, gender, relationship length, daily Facebook logins, and time spent per login). One week later, participants reported their level of Facebook partner-monitoring during the previous week. Regression analyses supported the standard TPB constructs of attitude and subjective norm in predicting intentions to engage in frequent Facebook partner-monitoring, with intention, in turn, predicting behavior. Partner trust, but not self-esteem, significantly predicted frequent Facebook partner-monitoring intentions. Of the demographic characteristics, daily Facebook logins significantly predicted both intention and behavior and, unexpectedly, relationship length directly affected behavior. Overall, the current study revealed that frequent Facebook partner-monitoring is influenced by attitudinal, normative, and relational factors and, potentially, increased visits to Facebook. These findings provide a new understanding of an individual's use of the world's leading SNS to monitor their partner's activities and provide a foundation for future studies to investigate the potential negative implications this activity may have for those in romantic relationships.

  9. Dynamic use of geoscience information to develop scientific understanding for a nuclear waste repository

    International Nuclear Information System (INIS)

    Cook, N.G.W.; Tsang, C.F.

    1990-01-01

    The development and safety evaluation of a nuclear waste geologic repository require a proper scientific understanding of the site response. Such scientific understanding depends on information from a number of geoscience disciplines, including geology, geophysics, geochemistry, geomechanics and hydrogeology. The information comes in four stages: (1) general regional survey data base, (2) surface-based testing, (3) exploratory shaft testing, and (4) repository construction and evaluation. A discussion is given on the dynamic use of the information through the different stages. We point out the need for abstracting, deriving and updating a quantitative spatial and process model (QSPM) to develop a scientific understanding of site responses as a crucial element in the dynamic procedure. 2 figs

  10. Dynamic localization and shear-induced hopping of particles: A way to understand the rheology of dense colloidal dispersions

    International Nuclear Information System (INIS)

    Jiang, Tianying; Zukoski, Charles F.

    2014-01-01

    For decades, attempts have been made to understand the formation of colloidal glasses and gels by linking suspension mechanics to particle properties where details of size, shape, and spatial dependencies of pair potentials present a bewildering array of variables that can be manipulated to achieve observed properties. Despite the range of variables that control suspension properties, one consistent observation is the remarkably similarity of flow properties observed as particle properties are varied. Understanding the underlying origins of the commonality in those behaviors (e.g., shear-thinning with increasing stress, diverging zero shear rate viscosity with increasing volume fraction, development of a dynamic yield stress plateau with increases in volume faction or strength of attraction, development of two characteristic relaxation times probed in linear viscoelasticity, the creation of a rubbery plateau modulus at high strain frequencies, and shear-thickening) remains a challenge. Recently, naïve mode coupling and dynamic localization theories have been developed to capture collective behavior giving rise to formation of colloidal glasses and gels. This approach characterizes suspension mechanics of strongly interacting particles in terms of sluggish long-range particle diffusion modulated by varying particle interactions and volume fraction. These theories capture the scaling of the modulus with the volume fraction and strength of interparticle attraction, the frequency dependence of the moduli at the onset of the gel/glass transition, together with the divergence of the zero shear rate viscosity and cessation of diffusivity for hard sphere systems as close packing is approached. In this study, we explore the generality of the predictions of dynamic localization theory for systems of particles composed of bimodal particle size distributions experiencing weak interactions. We find that the mechanical properties of these suspensions are well captured within

  11. Understanding how discrete populations of hypothalamic neurons orchestrate complicated behavioral states

    Directory of Open Access Journals (Sweden)

    Allison eGraebner

    2015-08-01

    Full Text Available A major question in systems neuroscience is how a single population of neurons can interact with the rest of the brain to orchestrate complex behavioral states. The hypothalamus contains many such discrete neuronal populations that individually regulate arousal, feeding, and drinking. For example, hypothalamic neurons that express hypocretin (Hcrt neuropeptides can sense homeostatic and metabolic factors affecting wakefulness and orchestrate organismal arousal. Neurons that express agouti-related protein (AgRP can sense the metabolic needs of the body and orchestrate a state of hunger. The organum vasculosum of the lamina terminalis (OVLT can detect the hypertonicity of blood and orchestrate a state of thirst. Each hypothalamic population is sufficient to generate complicated behavioral states through the combined efforts of distinct efferent projections. The principal challenge to understanding these brain systems is therefore to determine the individual roles of each downstream projection for each behavioral state. In recent years, the development and application of temporally precise, genetically encoded tools have greatly improved our understanding of the structure and function of these neural systems. This review will survey recent advances in our understanding of how these individual hypothalamic populations can orchestrate complicated behavioral states due to the combined efforts of individual downstream projections.

  12. Human behavior understanding for assisted living by means of hierarchical context free grammars

    Science.gov (United States)

    Rosani, A.; Conci, N.; De Natale, F. G. B.

    2014-03-01

    Human behavior understanding has attracted the attention of researchers in various fields over the last years. Recognizing behaviors with sufficient accuracy from sensors analysis is still an unsolved problem, because of many reasons, including the low accuracy of the data, differences in the human behaviors as well as the gap between low-level sensors data and high-level scene semantics. In this context, an application that is attracting the interest of both public and industrial entities is the possibility to allow elderly or physically impaired people conducting a normal life at home. Ambient intelligence (AmI) technologies, intended as the possibility of automatically detecting and reacting to the status of the environment and of the persons, is probably the major enabling factor for the achievement of such an ambitious objective. AmI technologies require suitable networks of sensors and actuators, as well as adequate processing and communication technologies. In this paper we propose a solution based on context free grammars for human behavior understanding with an application to assisted living. First, the grammars of the different actions performed by a person in his/her daily life are discovered. Then, a longterm analysis of the behavior is used to generate a control grammar, taking care of the context when an action is performed, and adding semantics. The proposed framework is tested on a dataset acquired in a real environment and compared with state of the art methods already available for the problem considered.

  13. A Theoretical Approach to Understanding Population Dynamics with Seasonal Developmental Durations

    Science.gov (United States)

    Lou, Yijun; Zhao, Xiao-Qiang

    2017-04-01

    There is a growing body of biological investigations to understand impacts of seasonally changing environmental conditions on population dynamics in various research fields such as single population growth and disease transmission. On the other side, understanding the population dynamics subject to seasonally changing weather conditions plays a fundamental role in predicting the trends of population patterns and disease transmission risks under the scenarios of climate change. With the host-macroparasite interaction as a motivating example, we propose a synthesized approach for investigating the population dynamics subject to seasonal environmental variations from theoretical point of view, where the model development, basic reproduction ratio formulation and computation, and rigorous mathematical analysis are involved. The resultant model with periodic delay presents a novel term related to the rate of change of the developmental duration, bringing new challenges to dynamics analysis. By investigating a periodic semiflow on a suitably chosen phase space, the global dynamics of a threshold type is established: all solutions either go to zero when basic reproduction ratio is less than one, or stabilize at a positive periodic state when the reproduction ratio is greater than one. The synthesized approach developed here is applicable to broader contexts of investigating biological systems with seasonal developmental durations.

  14. Leveraging organizational dynamics in buildings to change behavior

    Science.gov (United States)

    Hewitt, Elizabeth L.

    Buildings may be stationary, but they are not static; they are dynamic and active collectives of agents and actors, and play an important cultural and social role in shaping norms and influencing outcomes in the built environment. This research develops and applies a unique framework that conceptualizes the urban multifamily residential building as an organization, and seeks to use this lens to better understand the role of organizational characteristics in influencing energy efficiency in buildings. This work finds that an organizational analogy is a fruitful approach for understanding buildings, and that buildings in many ways can and do function successfully as organizations. In particular, eight organizational characteristics are explored here that extend well to buildings. These eight organizational characteristics are also explored more deeply to support an argument that some buildings have an organizational advantage that well positions them to undertake energy efficiency initiatives. One organizational characteristic -- the ownership type of the building -- is determined to be particularly important in driving energy outcomes in multifamily buildings in New York City. In particular, it was found that cooperative buildings in the New York City housing market consume less energy citywide than other types of multifamily properties, holding all else equal. Conversely, it was also found that rental buildings tend to consume more energy citywide. Subsequent qualitative case study work in a small Brooklyn cooperative building offers a deeper understanding of organizational decentralization and its role in driving decision-making and outcomes in the building. Additional comparative work in two rental properties -- one high-income and one low-income -- adds additional context and understanding to economic considerations such as the influence of income in overriding centralized efforts to operate the building efficiently. Ultimately, this research develops an analogy

  15. Understanding the decline and resilience loss of a long-lived social-ecological system: insights from system dynamics

    Directory of Open Access Journals (Sweden)

    Alicia Tenza

    2017-06-01

    Full Text Available Collapse of social-ecological systems (SESs is a common process in human history. Depletion of natural resources, scarcity of human capital, or both, is/are common pathways toward collapse. We use the system dynamics approach to better understand specific problems of small-scale, long-lived SESs. We present a qualitative (or conceptual model using the conceptualization process of the system dynamics approach to study the dynamics of an oasis in Mexico that has witnessed a dramatic transition to decline in recent decades. We used indepth interviews, participant observation, expert opinions, and official statistical data sets to define the boundaries, and structure in a causal loop diagram of our studied system. We described historical trends and showed the reference mode for the main system variables (observed data, and analyzed the expected system behavior according to the system structure. We identified the main drivers that changed the system structure, as well as structural changes, and the effects of these changes on the dynamics, resilience, and vulnerability of this SES. We found that the tendency of this SES toward collapse was triggered by exogenous factors (growth of modern agriculture in nearby valleys, and socio-political relocation, and was maintained by an endogenous structure. These structural changes weakened the resilience of this SES. One of these changes resulted in a long-term maladaptation of the SES, which increased its vulnerability to frequent system disturbances (hurricanes and droughts. The conceptual model developed provides an in-depth qualitative description of the system, with an important amount of qualitative and quantitative information, to establish the structural hypothesis of the observed behavior. Using this qualitative model, the next research steps are to develop a quantitative model to test the qualitative theories, and to explore future scenarios of system resilience for decision-making processes to

  16. Understanding action control of parental support behavior for child physical activity.

    Science.gov (United States)

    Rhodes, Ryan E; Spence, John C; Berry, Tanya; Deshpande, Sameer; Faulkner, Guy; Latimer-Cheung, Amy E; O'Reilly, Norman; Tremblay, Mark S

    2016-02-01

    Parental support is the critical family-level variable linked to child physical activity (PA), yet the antecedents of support are poorly understood, and its relationship with intention is modest. The purpose of this study was to apply a framework designed to evaluate the intention-behavior gap, known as multiprocess action control (M-PAC), to understand parental support for regular child PA. Mothers (N = 1,253) with children 5-12 years of age completed measures of attitudes, perceived control over support, behavioral regulation tactics (e.g., planning, self-monitoring), and intention to support. Over half (58%) reported on subsequent support behaviors 6 months later. Three intention-behavior profiles emerged: (a) nonintenders (26.4%; n = 331), (b) unsuccessful intenders (36.6%; n = 458), and (c) successful intenders (33%; n = 414). Congruent with M-PAC, a discriminant function analysis showed that affective attitude about support (r = .18), perceived behavioral control over support (r = .55), and behavioral regulation (r = .55) distinguished between all 3 intention-behavior profiles. A disaggregated analysis of specific behavioral regulation tactics showed that most distinguished all 3 profiles, yet planning, information seeking, and monitoring were the critical correlates of the discriminant function. The majority of mothers had positive intentions to support regular child PA, yet over half failed to enact this support. Difficulty of intention translating into support behavior arises from compromised control over support, self-regulation skills, and perceptions that the support experience is unenjoyable. Interventions aimed at strengthening these factors are recommended to improve parental support action control. (c) 2016 APA, all rights reserved).

  17. Expanding the Understanding of Risk Behavior Associated With Homelessness Among Veterans.

    Science.gov (United States)

    Harris, Taylor; Kintzle, Sara; Wenzel, Suzanne; Castro, Carl Andrew

    2017-09-01

    To advance large-scale efforts to end veteran homelessness, an understanding of factors that contribute to housing insecurity is necessary. Common risk behaviors (e.g., substance use and risky sexual practices) are associated with lengthier experiences of homelessness among the general homeless population, but less understood among homeless veterans. Additionally, whether emerging risk behaviors among veterans (e.g., sensation seeking and aggression) are associated with lengthy homeless experiences is unknown. Data were drawn from a sample of Los Angeles County veterans surveyed using a mixed nonprobability sampling strategy, which included recruiting veterans via national and local veterans service organizations, college organizations, and social media campaigns. Measures aligning with factors of sensation seeking (reckless driving, gambling, suicidal ideation); substance use (alcohol misuse, tobacco use, driving while intoxicated); risky sexual practices (risking getting a sexually transmitted disease); and aggression (looking to start a fight) were tested in multivariate, multinomial logistic regression analyses to determine their association with varying lengths of homelessness in the past year (less than 1 month, 2-6 months, 6 months to 1 year). Risking getting a sexually transmitted disease, gambling, suicidal ideation, alcohol misuse, tobacco use, driving while intoxicated, and looking to start a fight were associated with 6 or more months of homelessness. Several indicators of risk were associated with brief periods of homelessness, including gambling and looking to start a fight. Although a clear exposure-response effect was not detected with risk behaviors, results suggested there may be some wavering of engagement in risk behaviors over time. Findings suggest sensation seeking and aggression risk behaviors should be included in risk assessments and prevention efforts along with substance use and risky sexual practices to reduce veterans' risk of becoming

  18. Dynamic behavior of a nonlinear rational difference equation and generalization

    Directory of Open Access Journals (Sweden)

    Shi Qihong

    2011-01-01

    Full Text Available Abstract This paper is concerned about the dynamic behavior for the following high order nonlinear difference equation x n = (x n-k + x n-m + x n-l /(x n-k x n-m + x n-m x n-l +1 with the initial data { x - l , x - l + 1 , … , x - 1 } ∈ ℝ + l and 1 ≤ k ≤ m ≤ l. The convergence of solution to this equation is investigated by introducing a new sequence, which extends and includes corresponding results obtained in the references (Li in J Math Anal Appl 312:103-111, 2005; Berenhaut et al. Appl. Math. Lett. 20:54-58, 2007; Papaschinopoulos and Schinas J Math Anal Appl 294:614-620, 2004 to a large extent. In addition, some propositions for generalized equations are reported.

  19. Learning Methods for Dynamic Topic Modeling in Automated Behavior Analysis.

    Science.gov (United States)

    Isupova, Olga; Kuzin, Danil; Mihaylova, Lyudmila

    2017-09-27

    Semisupervised and unsupervised systems provide operators with invaluable support and can tremendously reduce the operators' load. In the light of the necessity to process large volumes of video data and provide autonomous decisions, this paper proposes new learning algorithms for activity analysis in video. The activities and behaviors are described by a dynamic topic model. Two novel learning algorithms based on the expectation maximization approach and variational Bayes inference are proposed. Theoretical derivations of the posterior estimates of model parameters are given. The designed learning algorithms are compared with the Gibbs sampling inference scheme introduced earlier in the literature. A detailed comparison of the learning algorithms is presented on real video data. We also propose an anomaly localization procedure, elegantly embedded in the topic modeling framework. It is shown that the developed learning algorithms can achieve 95% success rate. The proposed framework can be applied to a number of areas, including transportation systems, security, and surveillance.

  20. Human turnover dynamics during sleep: Statistical behavior and its modeling

    Science.gov (United States)

    Yoneyama, Mitsuru; Okuma, Yasuyuki; Utsumi, Hiroya; Terashi, Hiroo; Mitoma, Hiroshi

    2014-03-01

    Turnover is a typical intermittent body movement while asleep. Exploring its behavior may provide insights into the mechanisms and management of sleep. However, little is understood about the dynamic nature of turnover in healthy humans and how it can be modified in disease. Here we present a detailed analysis of turnover signals that are collected by accelerometry from healthy elderly subjects and age-matched patients with neurodegenerative disorders such as Parkinson's disease. In healthy subjects, the time intervals between consecutive turnover events exhibit a well-separated bimodal distribution with one mode at ⩽10 s and the other at ⩾100 s, whereas such bimodality tends to disappear in neurodegenerative patients. The discovery of bimodality and fine temporal structures (⩽10 s) is a contribution that is not revealed by conventional sleep recordings with less time resolution (≈30 s). Moreover, we estimate the scaling exponent of the interval fluctuations, which also shows a clear difference between healthy subjects and patients. We incorporate these experimental results into a computational model of human decision making. A decision is to be made at each simulation step between two choices: to keep on sleeping or to make a turnover, the selection of which is determined dynamically by comparing a pair of random numbers assigned to each choice. This decision is weighted by a single parameter that reflects the depth of sleep. The resulting simulated behavior accurately replicates many aspects of observed turnover patterns, including the appearance or disappearance of bimodality and leads to several predictions, suggesting that the depth parameter may be useful as a quantitative measure for differentiating between normal and pathological sleep. These findings have significant clinical implications and may pave the way for the development of practical sleep assessment technologies.

  1. Smoking cessation: an application of theory of planned behavior to understanding progress through stages of change.

    Science.gov (United States)

    Bledsoe, Linda K

    2006-07-01

    The purpose of this research was to investigate variables relevant to smoking cessation early in the process of change through an application of the Theory of Planned Behavior [Ajzen, I. (1985). From intentions to actions: A theory of planned behavior. In J. Kuhl and J. Beckman (Eds). Action-control: From cognition to behavior (pp.11-39). Heidelberg: Springer.] to the temporal structure provided by the Transtheoretical Model. Study 1 was a preliminary elicitation study (n=68) conducted to ground the concepts used in the model testing in Study 2 [Ajzen, I., Fishbein, M. (1980). Understanding attitudes and predicting social behavior, Englewood Cliffs, NJ: Prentice-Hall.]. Study 2 tested the proposed model fit with data from a sample of 230 adult smokers. Structural equation modeling did not support the Theory of Planned Behavior as a model of motivation for progress through the stages of change and highlighted measurement issues with perceived behavioral control. A modified model using the Theory of Reasoned Action provided a good fit to the data, accounting for approximately 64% of the variance in intention to quit smoking and stage of change. This research addresses the need for a more complete theoretical rationale for progress through stages of change.

  2. Generalization of the dynamic clamp concept in neurophysiology and behavior.

    Directory of Open Access Journals (Sweden)

    Pablo Chamorro

    Full Text Available The idea of closed-loop interaction in in vitro and in vivo electrophysiology has been successfully implemented in the dynamic clamp concept strongly impacting the research of membrane and synaptic properties of neurons. In this paper we show that this concept can be easily generalized to build other kinds of closed-loop protocols beyond (or in addition to electrical stimulation and recording in neurophysiology and behavioral studies for neuroethology. In particular, we illustrate three different examples of goal-driven real-time closed-loop interactions with drug microinjectors, mechanical devices and video event driven stimulation. Modern activity-dependent stimulation protocols can be used to reveal dynamics (otherwise hidden under traditional stimulation techniques, achieve control of natural and pathological states, induce learning, bridge between disparate levels of analysis and for a further automation of experiments. We argue that closed-loop interaction calls for novel real time analysis, prediction and control tools and a new perspective for designing stimulus-response experiments, which can have a large impact in neuroscience research.

  3. Copy of Using Emulation and Simulation to Understand the Large-Scale Behavior of the Internet.

    Energy Technology Data Exchange (ETDEWEB)

    Adalsteinsson, Helgi; Armstrong, Robert C.; Chiang, Ken; Gentile, Ann C.; Lloyd, Levi; Minnich, Ronald G.; Vanderveen, Keith; Van Randwyk, Jamie A; Rudish, Don W.

    2008-10-01

    We report on the work done in the late-start LDRDUsing Emulation and Simulation toUnderstand the Large-Scale Behavior of the Internet. We describe the creation of a researchplatform that emulates many thousands of machines to be used for the study of large-scale inter-net behavior. We describe a proof-of-concept simple attack we performed in this environment.We describe the successful capture of a Storm bot and, from the study of the bot and furtherliterature search, establish large-scale aspects we seek to understand via emulation of Storm onour research platform in possible follow-on work. Finally, we discuss possible future work.3

  4. Classification of quench-dynamical behaviors in spinor condensates

    Science.gov (United States)

    Daǧ, Ceren B.; Wang, Sheng-Tao; Duan, L.-M.

    2018-02-01

    Thermalization of isolated quantum systems is a long-standing fundamental problem where different mechanisms are proposed over time. We contribute to this discussion by classifying the diverse quench-dynamical behaviors of spin-1 Bose-Einstein condensates, which includes well-defined quantum collapse and revivals, thermalization, and certain special cases. These special cases are either nonthermal equilibration with no revival but a collapse even though the system has finite degrees of freedom or no equilibration with no collapse and revival. Given that some integrable systems are already shown to demonstrate the weak form of eigenstate thermalization hypothesis (ETH), we determine the regions where ETH holds and fails in this integrable isolated quantum system. The reason behind both thermalizing and nonthermalizing behaviors in the same model under different initial conditions is linked to the discussion of "rare" nonthermal states existing in the spectrum. We also propose a method to predict the collapse and revival time scales and find how they scale with the number of particles in the condensate. We use a sudden quench to drive the system to nonequilibrium and hence the theoretical predictions given in this paper can be probed in experiments.

  5. Stocks’ pricing dynamics and behavioral finance: A review

    Directory of Open Access Journals (Sweden)

    Paritosh Chandra Sinha

    2015-09-01

    Full Text Available In a brief review of the literature on stocks’ pricing, the study shows that information vis-à-vis noise serves critical roles in the equilibrium process. It is dynamic in nature and there are different infiltrating aspects from the standard finance to behavioral finance points of views. The aspects of market efficiency, fundamental risk, noise traders’ risk, and implementation costs make the stock markets noisy and thereby, limit the arbitrage opportunity of informed traders. Investors’ psychological bases viz., belief and preferences contribute more in the equilibrium process. Beliefs include representativeness, conservativeness, and anchoring, availability biases, optimism and wishful thinking, overconfidence, and herd behavior tendency on the part of the investors. On the preferences, investors are influenced by disposition effect, prospects based on reference points, mental accounting, ambiguity aversion, and self control.The study explores the empirical literature also and reviews the six puzzles in the standard finance. Finally, the work identifies a few research gaps to be addressed in the literature.

  6. Understanding Information Seeking Behavior of Indonesian Postgraduate Students in Malaysian Universities: An Empirical Study

    OpenAIRE

    Muhammad Subhan; Ahmad Bashawir Abdul Ghani

    2013-01-01

    Abstract : This study investigates Indonesian postgraduate student’s experience at the pre-sessional program of the process of seeking information and the strategies they used throughout the process. The objective is to understand their information seeking behavior particularly academic-related information in order to improve the effectiveness of educational communication in Malaysia higher institutions. Two research questions are addressed: what experiences do pre-sessional students face i...

  7. The contributions of cognitive neuroscience and neuroimaging to understanding mechanisms of behavior change in addiction.

    Science.gov (United States)

    Morgenstern, Jon; Naqvi, Nasir H; Debellis, Robert; Breiter, Hans C

    2013-06-01

    In the last decade, there has been an upsurge of interest in understanding the mechanisms of behavior change (MOBC) and effective behavioral interventions as a strategy to improve addiction-treatment efficacy. However, there remains considerable uncertainty about how treatment research should proceed to address the MOBC issue. In this article, we argue that limitations in the underlying models of addiction that inform behavioral treatment pose an obstacle to elucidating MOBC. We consider how advances in the cognitive neuroscience of addiction offer an alternative conceptual and methodological approach to studying the psychological processes that characterize addiction, and how such advances could inform treatment process research. In addition, we review neuroimaging studies that have tested aspects of neurocognitive theories as a strategy to inform addiction therapies and discuss future directions for transdisciplinary collaborations across cognitive neuroscience and MOBC research. 2013 APA, all rights reserved

  8. Getting angry matters: Going beyond perspective taking and empathic concern to understand bystanders' behavior in bullying.

    Science.gov (United States)

    Pozzoli, Tiziana; Gini, Gianluca; Thornberg, Robert

    2017-12-01

    The present study examined the relations between different empathic dimensions and bystanders' behavior in bullying. Specifically, the indirect effects of empathic concern and perspective taking via empathic anger on defending and passive bystanding were tested in a sample of Italian young adolescents (N = 398; M age  = 12 years, 3 months, 47.2% girls). Path analysis confirmed the direct and indirect effects, via empathic anger, of empathic concern and perspective taking on bystanders' behavior, with the exception of the direct association between perspective taking and passive bystanding that was not significant. Our findings suggest that considering empathic anger together with empathic concern and perspective taking could help researchers to better understand the links between empathic dispositions and bystanders' behavior in bullying. Copyright © 2017. Published by Elsevier Ltd.

  9. Understanding behavioral intent to participate in shared decision-making in medically uncertain situations.

    Science.gov (United States)

    Maffei, Roxana M; Dunn, K; Zhang, J; Hsu, C E; Holmes, J H

    2012-01-01

    This article describes the process undertaken to identify and validate behavioral and normative beliefs and behavioral intent based on the Theory of Reasoned Action (TRA) and applied to men between the ages of 45 and 70 in the context of their participation in shared decision-making (SDM) in medically uncertain situations. This article also discusses the preliminary results of the aforementioned processes and explores potential future uses of this information that may facilitate greater understanding, efficiency and effectiveness of clinician-patient consultations. Twenty-five male subjects from the Philadelphia community participated in this study. Individual semi-structure patient interviews were conducted until data saturation was reached. Based on their review of the patient interview transcripts, researchers conducted a qualitative content analysis to identify prevalent themes and, subsequently, create a category framework. Qualitative indicators were used to evaluate respondents' experiences, beliefs, and behavioral intent relative to participation in shared decision-making during medical uncertainty. Based on the themes uncovered through the content analysis, a category framework was developed to facilitate understanding and increase the accuracy of predictions related to an individual's behavioral intent to participate in shared decision-making in medical uncertainty. The emerged themes included past experience with medical uncertainty, individual personality, and the relationship between the patient and his physician. The resulting three main framework categories include 1) an individual's Foundation for the concept of medical uncertainty, 2) how the individual Copes with medical uncertainty, and 3) the individual's Behavioral Intent to seek information and participate in shared decision-making during times of medically uncertain situations. The theme of Coping (with uncertainty) emerged as a particularly critical behavior/characteristic amongst the

  10. Composite dynamical behaviors in a simple series–parallel LC circuit

    International Nuclear Information System (INIS)

    Manimehan, I.; Philominathan, P.

    2012-01-01

    Highlights: ► We have presented a simple circuit exhibiting rich dynamical behaviors. ► The detailed study of the circuit is given by two parameter bifurcation diagram. ► The numerical, analytical and experimental results are good in agreement. ► The Chosen system seems to have potential application in future. - Abstract: In this paper, we report a variety of dynamical behaviors exhibited in a compact series–parallel LC circuit system comprising of two active elements, one linear negative conductance and one ordinary junction diode with piecewise linear v − i characteristics. For convenience, we consider the amplitude (E f ) and frequency (f) of the driving force as control parameters amongst various other parameters. We observe the phenomenon of antimonotonicity, torus breakdown to chaos, bubbles to chaos, period doubling to chaos and emergence of multiple attractors which follow a progressive sequence, etc. As an overview to understand many more variety of bifurcations and attractors, the construction of two parameter phase diagram is also shown pictorially. The chaotic dynamics of this circuit is realized by laboratory experiment, numerical and analytical investigations and found that the results are in good agreement with each other.

  11. Using Social Network Analysis to Better Understand Compulsive Exercise Behavior Among a Sample of Sorority Members.

    Science.gov (United States)

    Patterson, Megan S; Goodson, Patricia

    2017-05-01

    Compulsive exercise, a form of unhealthy exercise often associated with prioritizing exercise and feeling guilty when exercise is missed, is a common precursor to and symptom of eating disorders. College-aged women are at high risk of exercising compulsively compared with other groups. Social network analysis (SNA) is a theoretical perspective and methodology allowing researchers to observe the effects of relational dynamics on the behaviors of people. SNA was used to assess the relationship between compulsive exercise and body dissatisfaction, physical activity, and network variables. Descriptive statistics were conducted using SPSS, and quadratic assignment procedure (QAP) analyses were conducted using UCINET. QAP regression analysis revealed a statistically significant model (R 2 = .375, P exercise behavior. Physical activity, body dissatisfaction, and network variables were statistically significant predictor variables in the QAP regression model. In our sample, women who are connected to "important" or "powerful" people in their network are likely to have higher compulsive exercise scores. This result provides healthcare practitioners key target points for intervention within similar groups of women. For scholars researching eating disorders and associated behaviors, this study supports looking into group dynamics and network structure in conjunction with body dissatisfaction and exercise frequency.

  12. Grounding cognitive-level processes in behavior: the view from dynamic systems theory.

    Science.gov (United States)

    Samuelson, Larissa K; Jenkins, Gavin W; Spencer, John P

    2015-04-01

    Marr's seminal work laid out a program of research by specifying key questions for cognitive science at different levels of analysis. Because dynamic systems theory (DST) focuses on time and interdependence of components, DST research programs come to very different conclusions regarding the nature of cognitive change. We review a specific DST approach to cognitive-level processes: dynamic field theory (DFT). We review research applying DFT to several cognitive-level processes: object permanence, naming hierarchical categories, and inferring intent, that demonstrate the difference in understanding of behavior and cognition that results from a DST perspective. These point to a central challenge for cognitive science research as defined by Marr-emergence. We argue that appreciating emergence raises questions about the utility of computational-level analyses and opens the door to insights concerning the origin of novel forms of behavior and thought (e.g., a new chess strategy). We contend this is one of the most fundamental questions about cognition and behavior. Copyright © 2015 Cognitive Science Society, Inc.

  13. Is political behavior a viable coping strategy to perceived organizational politics? Unveiling the underlying resource dynamics.

    Science.gov (United States)

    Sun, Shuhua; Chen, Huaizhong

    2017-10-01

    [Correction Notice: An Erratum for this article was reported in Vol 102(10) of Journal of Applied Psychology (see record 2017-34254-001). In the article, Table 1 contained a formatting error. Correlation coefficient values in the last four cells of column 6 were misplaced with correlation coefficient values in the last four cells of column 7. All versions of this article have been corrected.] We conduct a theory-driven empirical investigation on whether political behavior, as a coping strategy to perceived organizational politics, creates resource trade-offs in moderating the relationship between perceived organizational politics and task performance. Drawing on conservation of resources theory, we hypothesize that political behavior mitigates the adverse effect of perceived organizational politics on task performance via psychological empowerment, yet exacerbates its adverse effect on task performance via emotional exhaustion. Three-wave multisource data from a sample of 222 employees and their 75 supervisors were collected for hypothesis testing. Findings supported our hypotheses. Our study enhances understandings of the complex resource dynamics of using political behavior to cope with perceived organizational politics and highlights the need to move stress-coping research from a focus on the stress-buffering effect of coping on outcomes to a focus on the underlying competing resource dynamics. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  14. PaGenBase: a pattern gene database for the global and dynamic understanding of gene function.

    Directory of Open Access Journals (Sweden)

    Jian-Bo Pan

    Full Text Available Pattern genes are a group of genes that have a modularized expression behavior under serial physiological conditions. The identification of pattern genes will provide a path toward a global and dynamic understanding of gene functions and their roles in particular biological processes or events, such as development and pathogenesis. In this study, we present PaGenBase, a novel repository for the collection of tissue- and time-specific pattern genes, including specific genes, selective genes, housekeeping genes and repressed genes. The PaGenBase database is now freely accessible at http://bioinf.xmu.edu.cn/PaGenBase/. In the current version (PaGenBase 1.0, the database contains 906,599 pattern genes derived from the literature or from data mining of more than 1,145,277 gene expression profiles in 1,062 distinct samples collected from 11 model organisms. Four statistical parameters were used to quantitatively evaluate the pattern genes. Moreover, three methods (quick search, advanced search and browse were designed for rapid and customized data retrieval. The potential applications of PaGenBase are also briefly described. In summary, PaGenBase will serve as a resource for the global and dynamic understanding of gene function and will facilitate high-level investigations in a variety of fields, including the study of development, pathogenesis and novel drug discovery.

  15. Young children’s understanding of angles in a dynamic geometry environment

    OpenAIRE

    Kaur, Harpreet

    2017-01-01

    Angle is an important topic in geometry. It is a concept that children find challenging to learn, in part because of its multifaceted nature. The purpose of this study is to understand how children’s thinking about angles evolves as they participate in a classroom setting featuring the use of a dynamic geometry environment (DGE) in which the concept of angle as turn was privileged, a concept that does not require a quantitative dimension. Three research questions were proposed for the study, ...

  16. Dynamic Analytical Capability to Better Understand and Anticipate Extremist Shifts Within Populations under Authoritarian Regimes.

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, Michael Lewis [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-11-01

    The purpose of this work is to create a generalizable data- and theory-supported capability to better understand and anticipate (with quantifiable uncertainty): 1) how the dynamics of allegiance formations between various groups and society are impacted by active conflict and by third-party interventions and 2) how/why extremist allegiances co-evolve over time due to changing geopolitical, sociocultural, and military conditions.

  17. Simulation of dynamics behaviors for shipping equipment support with system dynamics analysis approach

    Directory of Open Access Journals (Sweden)

    Yang Song

    2015-05-01

    Full Text Available Purpose: The exactly and precisely supply of carrying spare parts has a crucial impact on support and could improve the performance of equipment. Spare parts support is the crux work which will be limited by spare parts allocation and support cost input. Reasonable support strategy can help in making good use of available resources and support the equipment in normal operational status. The purpose of this paper is to propose a dynamics model of spare parts support process based on considering the interaction of multiple factors, and explores the regulation of dynamics behavior in the system. In order to achieve the optimization strategy to improve the effect of support so that will enhance the relevant support parameters of equipment. Design/methodology/approach: Meditate the feedback relationship among some important factors of support that involve support cost, support time and maintenance ability. System dynamics theory is adopted to propose a dynamics model of spare parts support process, on the analysis of multiple factors and casual relationship to find some major ones which have crucial impact on spare parts support. Spare parts support cost and availability was regarded as the control objective, moreover, adjust the control paramours and improve the effect of cannibalization and lateral supply scheduling strategy for spares support. Findings: The factors of spare parts supply, demand and maintenance have relationship of control feedback, and adjust the value of some crucial factors can reduce the support cost and improve the availability value. The main finding is that adopting cannibalization strategy under condition of available materials can relieve the mission and operational availability decline caused by shortage of spare parts. Combining the lateral supply and cannibalization strategy can reduce the inventory of warship carrying spare parts. Practical implications: By controlling the value of key factors regarding aspect of spare

  18. Understanding action control of daily walking behavior among dog owners: a community survey.

    Science.gov (United States)

    Rhodes, Ryan E; Lim, Clarise

    2016-11-16

    Walking among dog owners may be a means to achieve health benefits, yet almost half of owners (approximately 30% of households) are not regularly walking their dogs. Current research on the correlates of dog walking has generally considered intention as the primary determinant of behavior, yet the intention-behavior relationship is modest. The purpose of this paper was to apply a framework designed to evaluate the intention-behavior gap, known as multi-process action control (M-PAC), to understand daily walking among dog owners. A community sample of adult dog owners (N = 227) in Victoria, Canada completed M-PAC measures of motivational (dog and human outcome expectations, affective judgments, perceived capability and opportunity), regulatory (planning), and reflexive (automaticity, identity) processes as well as intention to walk and behavior. Three intention-behavior profiles emerged: a) non-intenders who were not active (26%; n = 59), b) unsuccessful intenders who failed to enact their positive intentions (33%; n = 75), and c) successful intenders who were active (40%; n = 91). Congruent with M-PAC, a discriminant function analysis showed that affective judgements (r = 0.33), automaticity (r = 0.38), and planning (r = 0.33) distinguished between all three intention-behavior profiles, while identity (r = 0.22) and dog breed size (r = 0.28) differentiated between successful and unsuccessful intenders. The majority of dog owners have positive intentions to walk, yet almost half fail to meet these intentions. Interventions focused on affective judgments (e.g., more enjoyable places to walk), behavioral regulation (e.g., setting a concrete plan), habit (e.g., making routines and cues) and identity formation (e.g., affirmations of commitment) may help overcome difficulties with translating these intentions into action, thus increasing overall levels of walking.

  19. Understanding action control of daily walking behavior among dog owners: a community survey

    Directory of Open Access Journals (Sweden)

    Ryan E. Rhodes

    2016-11-01

    Full Text Available Abstract Background Walking among dog owners may be a means to achieve health benefits, yet almost half of owners (approximately 30% of households are not regularly walking their dogs. Current research on the correlates of dog walking has generally considered intention as the primary determinant of behavior, yet the intention-behavior relationship is modest. The purpose of this paper was to apply a framework designed to evaluate the intention-behavior gap, known as multi-process action control (M-PAC, to understand daily walking among dog owners. Method A community sample of adult dog owners (N = 227 in Victoria, Canada completed M-PAC measures of motivational (dog and human outcome expectations, affective judgments, perceived capability and opportunity, regulatory (planning, and reflexive (automaticity, identity processes as well as intention to walk and behavior. Results Three intention-behavior profiles emerged: a non-intenders who were not active (26%; n = 59, b unsuccessful intenders who failed to enact their positive intentions (33%; n = 75, and c successful intenders who were active (40%; n = 91. Congruent with M-PAC, a discriminant function analysis showed that affective judgements (r = 0.33, automaticity (r = 0.38, and planning (r = 0.33 distinguished between all three intention-behavior profiles, while identity (r = 0.22 and dog breed size (r = 0.28 differentiated between successful and unsuccessful intenders. Conclusions The majority of dog owners have positive intentions to walk, yet almost half fail to meet these intentions. Interventions focused on affective judgments (e.g., more enjoyable places to walk, behavioral regulation (e.g., setting a concrete plan, habit (e.g., making routines and cues and identity formation (e.g., affirmations of commitment may help overcome difficulties with translating these intentions into action, thus increasing overall levels of walking.

  20. Dispersal pathways, seed rains, and the dynamics of larval behavior.

    Science.gov (United States)

    Zimmer, Richard K; Fingerut, Jonathan T; Zimmer, Cheryl Ann

    2009-07-01

    Dispersing propagules (larvae, seeds, and spores) establish and maintain populations, which serve as templates for subsequent species interactions. Connectivity among demes derives, in large part, from connectivity between consecutive steps, release, transport, and settlement, in dispersal pathways. Concurrent measurements of individuals in each step are a necessary precursor to identifying governing mechanisms. Here we directly and definitively resolved the roles of physics and behavior in mediating dispersal pathways of an estuarine parasite between its intermediate hosts. Planktonic cercariae of Himasthla rhigedana, a parasitic flatworm, are functionally similar to lecithotrophic larvae of many free-living marine invertebrates. The combination of parasite life cycle characteristics and the relatively simple tidal flows in their habitat renders this system an effective model for dispersal studies. Simultaneous field measurements of larval release, transport, settlement, and the flow regime, together with mechanistic experiments, led to empirical understanding of host colonization. All dispersal steps were highly and significantly correlated over time and in space. This tight coupling resulted, unequivocally, from a suite of larval behaviors. Cercariae emerged from first intermediate host snails only during daytime flood tides, enhancing larval retention in the marsh. Daylight triggered downward swimming, and within seconds, cercariae overpowered turbulent mixing, landing in benthic habitat of second intermediate host snails and crabs. Larvae settled (encysted) on external regions of snails/crabs that, presumably, were most vulnerable to ingestion by definitive host shorebirds. In total, cercarial behaviors greatly foreshortened dispersal distances, magnified local parasite prevalence, and increased the likelihood of large-scale transmission by definitive hosts. Cracking open the black box of dispersal thus revealed mechanisms, connectivity, and ecological

  1. Putting the Mind in the Brain: Promoting an Appreciation of the Biological Basis to Understanding Human Behavior

    Science.gov (United States)

    Neumann, David L.

    2010-01-01

    A surprising number of students in psychology, behavioral science, and related social science classes fail to appreciate the importance of biological mechanisms to understanding behavior. To help teachers promote this understanding, this paper outlines six sources of evidence. These are (a) phylogenetic, (b) genetic/developmental, (c) clinical,…

  2. Balancing Automatic-Controlled Behaviors and Emotional-Salience States: A Dynamic Executive Functioning Hypothesis.

    Science.gov (United States)

    Kluwe-Schiavon, Bruno; Viola, Thiago W; Sanvicente-Vieira, Breno; Malloy-Diniz, Leandro F; Grassi-Oliveira, Rodrigo

    2016-01-01

    Recently, there has been growing interest in understanding how executive functions are conceptualized in psychopathology. Since several models have been proposed, the major issue lies within the definition of executive functioning itself. Theoretical discussions have emerged, narrowing the boundaries between "hot" and "cold" executive functions or between self-regulation and cognitive control. Nevertheless, the definition of executive functions is far from a consensual proposition and it has been suggested that these models might be outdated. Current efforts indicate that human behavior and cognition are by-products of many brain systems operating and interacting at different levels, and therefore, it is very simplistic to assume a dualistic perspective of information processing. Based upon an adaptive perspective, we discuss how executive functions could emerge from the ability to solve immediate problems and to generalize successful strategies, as well as from the ability to synthesize and to classify environmental information in order to predict context and future. We present an executive functioning perspective that emerges from the dynamic balance between automatic-controlled behaviors and an emotional-salience state. According to our perspective, the adaptive role of executive functioning is to automatize efficient solutions simultaneously with cognitive demand, enabling individuals to engage such processes with increasingly complex problems. Understanding executive functioning as a mediator of stress and cognitive engagement not only fosters discussions concerning individual differences, but also offers an important paradigm to understand executive functioning as a continuum process rather than a categorical and multicomponent structure.

  3. Using chemistry and microfluidics to understand the spatial dynamics of complex biological networks.

    Science.gov (United States)

    Kastrup, Christian J; Runyon, Matthew K; Lucchetta, Elena M; Price, Jessica M; Ismagilov, Rustem F

    2008-04-01

    Understanding the spatial dynamics of biochemical networks is both fundamentally important for understanding life at the systems level and also has practical implications for medicine, engineering, biology, and chemistry. Studies at the level of individual reactions provide essential information about the function, interactions, and localization of individual molecular species and reactions in a network. However, analyzing the spatial dynamics of complex biochemical networks at this level is difficult. Biochemical networks are nonequilibrium systems containing dozens to hundreds of reactions with nonlinear and time-dependent interactions, and these interactions are influenced by diffusion, flow, and the relative values of state-dependent kinetic parameters. To achieve an overall understanding of the spatial dynamics of a network and the global mechanisms that drive its function, networks must be analyzed as a whole, where all of the components and influential parameters of a network are simultaneously considered. Here, we describe chemical concepts and microfluidic tools developed for network-level investigations of the spatial dynamics of these networks. Modular approaches can be used to simplify these networks by separating them into modules, and simple experimental or computational models can be created by replacing each module with a single reaction. Microfluidics can be used to implement these models as well as to analyze and perturb the complex network itself with spatial control on the micrometer scale. We also describe the application of these network-level approaches to elucidate the mechanisms governing the spatial dynamics of two networkshemostasis (blood clotting) and early patterning of the Drosophila embryo. To investigate the dynamics of the complex network of hemostasis, we simplified the network by using a modular mechanism and created a chemical model based on this mechanism by using microfluidics. Then, we used the mechanism and the model to

  4. Retrospective Analysis of Communication Events - Understanding the Dynamics of Collaborative Multi-Party Discourse

    Energy Technology Data Exchange (ETDEWEB)

    Cowell, Andrew J.; Haack, Jereme N.; McColgin, Dave W.

    2006-06-08

    This research is aimed at understanding the dynamics of collaborative multi-party discourse across multiple communication modalities. Before we can truly make sig-nificant strides in devising collaborative communication systems, there is a need to understand how typical users utilize com-putationally supported communications mechanisms such as email, instant mes-saging, video conferencing, chat rooms, etc., both singularly and in conjunction with traditional means of communication such as face-to-face meetings, telephone calls and postal mail. Attempting to un-derstand an individual’s communications profile with access to only a single modal-ity is challenging at best and often futile. Here, we discuss the development of RACE – Retrospective Analysis of Com-munications Events – a test-bed prototype to investigate issues relating to multi-modal multi-party discourse.

  5. On the Importance of Comparative Research for the Understanding of Human Behavior and Development: A Reply to Gottlieb & Lickliter (2004)

    Science.gov (United States)

    Maestripieri, Dario

    2005-01-01

    Comparative behavioral research is important for a number of reasons and can contribute to the understanding of human behavior and development in many different ways. Research with animal models of human behavior and development can be a source not only of general principles and testable hypotheses but also of empirical information that may be…

  6. Behavioral dynamics and neural grounding of a dynamic field theory of multi-object tracking.

    Science.gov (United States)

    Spencer, J P; Barich, K; Goldberg, J; Perone, S

    2012-09-01

    The ability to dynamically track moving objects in the environment is crucial for efficient interaction with the local surrounds. Here, we examined this ability in the context of the multi-object tracking (MOT) task. Several theories have been proposed to explain how people track moving objects; however, only one of these previous theories is implemented in a real-time process model, and there has been no direct contact between theories of object tracking and the growing neural literature using ERPs and fMRI. Here, we present a neural process model of object tracking that builds from a Dynamic Field Theory of spatial cognition. Simulations reveal that our dynamic field model captures recent behavioral data examining the impact of speed and tracking duration on MOT performance. Moreover, we show that the same model with the same trajectories and parameters can shed light on recent ERP results probing how people distribute attentional resources to targets vs. distractors. We conclude by comparing this new theory of object tracking to other recent accounts, and discuss how the neural grounding of the theory might be effectively explored in future work.

  7. Computational Cellular Dynamics Based on the Chemical Master Equation: A Challenge for Understanding Complexity

    Science.gov (United States)

    Liang, Jie; Qian, Hong

    2010-01-01

    Modern molecular biology has always been a great source of inspiration for computational science. Half a century ago, the challenge from understanding macromolecular dynamics has led the way for computations to be part of the tool set to study molecular biology. Twenty-five years ago, the demand from genome science has inspired an entire generation of computer scientists with an interest in discrete mathematics to join the field that is now called bioinformatics. In this paper, we shall lay out a new mathematical theory for dynamics of biochemical reaction systems in a small volume (i.e., mesoscopic) in terms of a stochastic, discrete-state continuous-time formulation, called the chemical master equation (CME). Similar to the wavefunction in quantum mechanics, the dynamically changing probability landscape associated with the state space provides a fundamental characterization of the biochemical reaction system. The stochastic trajectories of the dynamics are best known through the simulations using the Gillespie algorithm. In contrast to the Metropolis algorithm, this Monte Carlo sampling technique does not follow a process with detailed balance. We shall show several examples how CMEs are used to model cellular biochemical systems. We shall also illustrate the computational challenges involved: multiscale phenomena, the interplay between stochasticity and nonlinearity, and how macroscopic determinism arises from mesoscopic dynamics. We point out recent advances in computing solutions to the CME, including exact solution of the steady state landscape and stochastic differential equations that offer alternatives to the Gilespie algorithm. We argue that the CME is an ideal system from which one can learn to understand “complex behavior” and complexity theory, and from which important biological insight can be gained. PMID:24999297

  8. A non-parametric hierarchical model to discover behavior dynamics from tracks

    NARCIS (Netherlands)

    Kooij, J.F.P.; Englebienne, G.; Gavrila, D.M.

    2012-01-01

    We present a novel non-parametric Bayesian model to jointly discover the dynamics of low-level actions and high-level behaviors of tracked people in open environments. Our model represents behaviors as Markov chains of actions which capture high-level temporal dynamics. Actions may be shared by

  9. UNDERSTANDING OF NON VERBAL BEHAVIOR CLIENTS AND TECHNIQUES IN COUNSELING SESSION

    Directory of Open Access Journals (Sweden)

    afdal afdal

    2016-06-01

    Full Text Available The practice of counseling by counselor not only need the skills to understand what is expressed by the client, but were further able to understand and have skills in giving meaning to the nonverbal communication, demonstrated by the behavior of a counseling session. During this time many of counselors who focus only on what is revealed by the client and using verbal techniques alone without seeing what goes on inside the client more deeply to understand the communication indicated by nonverbal behavior. The techniques used in the discussion of this article provides the inspiration that counseling is an art, not superficial, not skeptical and just focus on one technique alone, but many of the techniques that can be used to explore client issues. Furthermore, this paper supports the philosophical theory of Gestalt who believe that the client can feel the direct presence in the counseling sessions through the practices of the techniques used, to interpret the expression of various communications made, stationing themselves and find their own meaning.

  10. What the Dynamic Systems Approach Can Offer for Understanding Development: An Example of Mid-childhood Reaching.

    Science.gov (United States)

    Golenia, Laura; Schoemaker, Marina M; Otten, Egbert; Mouton, Leonora J; Bongers, Raoul M

    2017-01-01

    The Dynamic Systems Approach (DSA) to development has been shown to be a promising theory to understand developmental changes. In this perspective, we use the example of mid-childhood (6- to 10-years of age) reaching to show how using the DSA can advance the understanding of development. Mid-childhood is an important developmental period that has often been overshadowed by the focus on the acquisition of reaching during infancy. This underrepresentation of mid-childhood studies is unjustified, as earlier studies showed that important developmental changes in mid-childhood reaching occur that refine the skill of reaching. We review these studies here for the first time and show that different studies revealed different developmental trends, such as non-monotonic and linear trends, for variables such as movement time and accuracy at target. Unfortunately, proposed explanations for these developmental changes have been tailored to individual studies, limiting their scope. Also, explanations were focused on a single component or process in the system that supposedly causes developmental changes. Here, we propose that the DSA can offer an overarching explanation for developmental changes in this research field. According to the DSA, motor behavior emerges from interactions of multiple components entailed by the person, environment, and task. Changes in all these components can potentially contribute to the emerging behavior. We show how the principles of change of the DSA can be used as an overarching framework by applying these principles not only to development, but also the behavior itself. This underlines its applicability to other fields of development.

  11. Toward Understanding the Dynamics of Microbial Communities in an Estuarine System

    KAUST Repository

    Zhang, Weipeng

    2014-04-14

    Community assembly theories such as species sorting theory provide a framework for understanding the structures and dynamics of local communities. The effect of theoretical mechanisms can vary with the scales of observation and effects of specific environmental factors. Based on 16S rRNA gene tag pyrosequencing, different structures and temporal succession patterns were discovered between the surface sediments and bottom water microbial communities in the Pearl River Estuary (PRE). The microbial communities in the surface sediment samples were more diverse than those in the bottom water samples, and several genera were specific for the water or sediment communities. Moreover, water temperature was identified as the main variable driving community dynamics and the microbial communities in the sediment showed a greater temporal change. We speculate that nutrient-based species sorting and bacterial plasticity to the temperature contribute to the variations observed between sediment and water communities in the PRE. This study provides a more comprehensive understanding of the microbial community structures in a highly dynamic estuarine system and sheds light on the applicability of ecological theoretical mechanisms.

  12. Toward understanding the dynamics of microbial communities in an estuarine system.

    Directory of Open Access Journals (Sweden)

    Weipeng Zhang

    Full Text Available Community assembly theories such as species sorting theory provide a framework for understanding the structures and dynamics of local communities. The effect of theoretical mechanisms can vary with the scales of observation and effects of specific environmental factors. Based on 16S rRNA gene tag pyrosequencing, different structures and temporal succession patterns were discovered between the surface sediments and bottom water microbial communities in the Pearl River Estuary (PRE. The microbial communities in the surface sediment samples were more diverse than those in the bottom water samples, and several genera were specific for the water or sediment communities. Moreover, water temperature was identified as the main variable driving community dynamics and the microbial communities in the sediment showed a greater temporal change. We speculate that nutrient-based species sorting and bacterial plasticity to the temperature contribute to the variations observed between sediment and water communities in the PRE. This study provides a more comprehensive understanding of the microbial community structures in a highly dynamic estuarine system and sheds light on the applicability of ecological theoretical mechanisms.

  13. Static and Dynamic Wetting Behavior of Triglycerides on Solid Surfaces.

    Science.gov (United States)

    Michalski; Saramago

    2000-07-15

    Triglyceride wetting properties on solid surfaces of different hydro-phobicities were investigated using three different methods, namely, the sessile drop method for static contact angle measurements, the Wilhelmy method for dynamic contact angle measurements, and the captive bubble method to investigate thin triglyceride film stability. For solid surfaces having a surface free energy higher than the surface tension of triglycerides (tributyrin, tricaprylin, and triolein), a qualitative correlation was observed between wetting and solid/triglyceride relative hydrophobicities. On surfaces presenting extreme hydrophobic or hydrophilic properties, medium-chain triglycerides had a behavior similar to that of long-chain unsaturated ones. On a high-energy surface (glass), tricaprylin showed an autophobic effect subsequent to molecular adsorption in trident conformation on the solid, observed with the three methods. Thin triglyceride films between an air bubble and a solid surface were stable for a short time, for solids with a surface free energy larger than the triglyceride surface tension. If the solid surface had a lower surface free energy, the thin film collapsed after a time interval which increased with triglyceride viscosity. Copyright 2000 Academic Press.

  14. Dynamic Behavior of Reverse Flow Reactor for Lean Methane Combustion

    Directory of Open Access Journals (Sweden)

    Yogi W. Budhi

    2014-09-01

    Full Text Available The stability of reactor operation for catalytic oxidation of lean CH4 has been investigated through modeling and simulation, particularly the influence of switching time and heat extraction on reverse flow reactor (RFR performance. A mathematical model of the RFR was developed, based on one-dimensional pseudo-homogeneous model for mass and heat balances, incorporating heat loss through the reactor wall. The configuration of the RFR consisted of inert-catalyst-inert, with or without heat extraction that makes it possible to store the energy released by the exothermic reaction of CH4 oxidation. The objective of this study was to investigate the dynamic behavior of the RFR for lean methane oxidation and to find the optimum condition by exploring a stability analysis of the simple reactor. The optimum criteria were defined in terms of CH4 conversion, CH4 slip, and heat accumulation in the RFR. At a switching time of 100 s, the CH4 conversion reached the maximum value, while the CH4 slip attained its minimum value. The RFR could operate autothermally with positive heat accumulation, i.e. 0.02 J/s. The stability of the RFR in terms of heat accumulation was achieved at a switching time of 100 s.

  15. Understanding Angiography-Based Aneurysm Flow Fields through Comparison with Computational Fluid Dynamics.

    Science.gov (United States)

    Cebral, J R; Mut, F; Chung, B J; Spelle, L; Moret, J; van Nijnatten, F; Ruijters, D

    2017-06-01

    Hemodynamics is thought to be an important factor for aneurysm progression and rupture. Our aim was to evaluate whether flow fields reconstructed from dynamic angiography data can be used to realistically represent the main flow structures in intracranial aneurysms. DSA-based flow reconstructions, obtained during interventional treatment, were compared qualitatively with flow fields obtained from patient-specific computational fluid dynamics models and quantitatively with projections of the computational fluid dynamics fields (by computing a directional similarity of the vector fields) in 15 cerebral aneurysms. The average similarity between the DSA and the projected computational fluid dynamics flow fields was 78% in the parent artery, while it was only 30% in the aneurysm region. Qualitatively, both the DSA and projected computational fluid dynamics flow fields captured the location of the inflow jet, the main vortex structure, the intrasaccular flow split, and the main rotation direction in approximately 60% of the cases. Several factors affect the reconstruction of 2D flow fields from dynamic angiography sequences. The most important factors are the 3-dimensionality of the intrasaccular flow patterns and inflow jets, the alignment of the main vortex structure with the line of sight, the overlapping of surrounding vessels, and possibly frame rate undersampling. Flow visualization with DSA from >1 projection is required for understanding of the 3D intrasaccular flow patterns. Although these DSA-based flow quantification techniques do not capture swirling or secondary flows in the parent artery, they still provide a good representation of the mean axial flow and the corresponding flow rate. © 2017 by American Journal of Neuroradiology.

  16. Understanding professional behavior: experiences of occupational therapy students in mental health settings.

    Science.gov (United States)

    Lyons, M

    1997-09-01

    A phenomenological study explored occupational therapy students' experiences in psychiatric fieldwork. Of particular interest was students' understanding of professional behavior toward persons who use mental health services. Data were gathered from 16 informants via in-depth interviews and participant observation on multiple occasions during fieldwork affiliations. Emerging from informants' views of professional behavior were difficulties in their reconciling conflicting expectations with regard to emotional and social distance from persons who use mental health services. Additionally, the informants experienced a need to assume authority and maintain control in their dealings with service users. Students' encounters with such issues during fieldwork are indicative of challenges they may face as health professionals in a changing climate of mental health services. These data are stimuli for reflection on features of professional relationships with service users, particularly in response to expectations of persons with disabilities regarding control over their lives.

  17. Bridging the Gap: Towards a Cell-Type Specific Understanding of Neural Circuits Underlying Fear Behaviors

    Science.gov (United States)

    McCullough, KM; Morrison, FG; Ressler, KJ

    2016-01-01

    Fear and anxiety-related disorders are remarkably common and debilitating, and are often characterized by dysregulated fear responses. Rodent models of fear learning and memory have taken great strides towards elucidating the specific neuronal circuitries underlying the learning of fear responses. The present review addresses recent research utilizing optogenetic approaches to parse circuitries underlying fear behaviors. It also highlights the powerful advances made when optogenetic techniques are utilized in a genetically defined, cell-type specific, manner. The application of next-generation genetic and sequencing approaches in a cell-type specific context will be essential for a mechanistic understanding of the neural circuitry underlying fear behavior and for the rational design of targeted, circuit specific, pharmacologic interventions for the treatment and prevention of fear-related disorders. PMID:27470092

  18. Real-Time G-Protein-Coupled Receptor Imaging to Understand and Quantify Receptor Dynamics

    Directory of Open Access Journals (Sweden)

    María S. Aymerich

    2011-01-01

    Full Text Available Understanding the trafficking of G-protein-coupled receptors (GPCRs and their regulation by agonists and antagonists is fundamental to develop more effective drugs. Optical methods using fluorescent-tagged receptors and spinning disk confocal microscopy are useful tools to investigate membrane receptor dynamics in living cells. The aim of this study was to develop a method to characterize receptor dynamics using this system which offers the advantage of very fast image acquisition with minimal cell perturbation. However, in short-term assays photobleaching was still a problem. Thus, we developed a procedure to perform a photobleaching-corrected image analysis. A study of short-term dynamics of the long isoform of the dopamine type 2 receptor revealed an agonist-induced increase in the mobile fraction of receptors with a rate of movement of 0.08 μm/s For long-term assays, the ratio between the relative fluorescence intensity at the cell surface versus that in the intracellular compartment indicated that receptor internalization only occurred in cells co-expressing G protein-coupled receptor kinase 2. These results indicate that the lateral movement of receptors and receptor internalization are not directly coupled. Thus, we believe that live imaging of GPCRs using spinning disk confocal image analysis constitutes a powerful tool to study of receptor dynamics.

  19. Human behavior understanding in networked sensing theory and applications of networks of sensors

    CERN Document Server

    Spagnolo, Paolo; Distante, Cosimo

    2014-01-01

    This unique text/reference provides a broad overview of both the technical challenges in sensor network development, and the real-world applications of distributed sensing. Important aspects of distributed computing in large-scale networked sensor systems are analyzed in the context of human behavior understanding, including such topics as systems design tools and techniques, in-network signals, and information processing. Additionally, the book examines a varied range of application scenarios, covering surveillance, indexing and retrieval, patient care, industrial safety, social and ambient

  20. #consumingitall: Understanding The Complex Relationship Between Media Consumption And Eating Behaviors

    OpenAIRE

    Albert, Stephanie L.

    2017-01-01

    Adolescents spend almost nine hours a day engaging with media. As a result, they are confronted with large amounts of obesogenic content that shapes their understanding of what are normal and acceptable eating behaviors. Utilizing primary data collected from a sample of 4,838 low-income, racially and ethnically diverse middle school students in Los Angeles County, I studied the effects of different types of media use (i.e., social media, TV/movies/videos, gaming, music, Internet) on dietary p...

  1. Understanding role of genome dynamics in host adaptation of gut commensal, L. reuteri

    Directory of Open Access Journals (Sweden)

    Shikha Sharma

    2017-10-01

    Full Text Available Lactobacillus reuteri is a gram-positive gut commensal and exhibits noteworthy adaptation to its vertebrate hosts. Host adaptation is often driven by inter-strain genome dynamics like expansion of insertion sequences that lead to acquisition and loss of gene(s and creation of large dynamic regions. In this regard we carried in-house genome sequencing of large number of L. reuteri strains origination from human, chicken, pig and rodents. We further next generation sequence data in understanding invasion and expansion of an IS element in shaping genome of strains belonging to human associated lineage. Finally, we share our experience in high-throughput genomic library preparation and generating high quality sequence data of a very low GC bacterium like L. reuteri.

  2. Exponential spreading and singular behavior of quantum dynamics near hyperbolic points.

    Science.gov (United States)

    Iomin, A

    2013-05-01

    Quantum dynamics of a particle in the vicinity of a hyperbolic point is considered. Expectation values of dynamical variables are calculated, and the singular behavior is analyzed. Exponentially fast extension of quantum dynamics is obtained, and conditions for this realization are analyzed.

  3. The developmental dynamics of task-avoidant behavior and math performance in kindergarten and elementary school

    OpenAIRE

    Hirvonen, Riikka; Tolvanen, Asko; Aunola, Kaisa; Nurmi, Jari-Erik

    2012-01-01

    Besides cognitive factors, children's learning at school may be influenced by more dynamic phenomena, such as motivation and achievement-related task-avoidant behavior. The present study examined the developmental dynamics of task-avoidant behavior and math performance from kindergarten to Grade 4. A total of 225 children were tested for their arithmetic skills in kindergarten and in Grades 1, 2, and 4 of elementary school. Children's task-avoidant behavior in learning situations was rated by...

  4. Application of Survival Analysis and Multistate Modeling to Understand Animal Behavior: Examples from Guide Dogs

    Science.gov (United States)

    Asher, Lucy; Harvey, Naomi D.; Green, Martin; England, Gary C. W.

    2017-01-01

    Epidemiology is the study of patterns of health-related states or events in populations. Statistical models developed for epidemiology could be usefully applied to behavioral states or events. The aim of this study is to present the application of epidemiological statistics to understand animal behavior where discrete outcomes are of interest, using data from guide dogs to illustrate. Specifically, survival analysis and multistate modeling are applied to data on guide dogs comparing dogs that completed training and qualified as a guide dog, to those that were withdrawn from the training program. Survival analysis allows the time to (or between) a binary event(s) and the probability of the event occurring at or beyond a specified time point. Survival analysis, using a Cox proportional hazards model, was used to examine the time taken to withdraw a dog from training. Sex, breed, and other factors affected time to withdrawal. Bitches were withdrawn faster than dogs, Labradors were withdrawn faster, and Labrador × Golden Retrievers slower, than Golden Retriever × Labradors; and dogs not bred by Guide Dogs were withdrawn faster than those bred by Guide Dogs. Multistate modeling (MSM) can be used as an extension of survival analysis to incorporate more than two discrete events or states. Multistate models were used to investigate transitions between states of training to qualification as a guide dog or behavioral withdrawal, and from qualification as a guide dog to behavioral withdrawal. Sex, breed (with purebred Labradors and Golden retrievers differing from F1 crosses), and bred by Guide Dogs or not, effected movements between states. We postulate that survival analysis and MSM could be applied to a wide range of behavioral data and key examples are provided. PMID:28804710

  5. Application of Survival Analysis and Multistate Modeling to Understand Animal Behavior: Examples from Guide Dogs

    Directory of Open Access Journals (Sweden)

    Lucy Asher

    2017-07-01

    Full Text Available Epidemiology is the study of patterns of health-related states or events in populations. Statistical models developed for epidemiology could be usefully applied to behavioral states or events. The aim of this study is to present the application of epidemiological statistics to understand animal behavior where discrete outcomes are of interest, using data from guide dogs to illustrate. Specifically, survival analysis and multistate modeling are applied to data on guide dogs comparing dogs that completed training and qualified as a guide dog, to those that were withdrawn from the training program. Survival analysis allows the time to (or between a binary event(s and the probability of the event occurring at or beyond a specified time point. Survival analysis, using a Cox proportional hazards model, was used to examine the time taken to withdraw a dog from training. Sex, breed, and other factors affected time to withdrawal. Bitches were withdrawn faster than dogs, Labradors were withdrawn faster, and Labrador × Golden Retrievers slower, than Golden Retriever × Labradors; and dogs not bred by Guide Dogs were withdrawn faster than those bred by Guide Dogs. Multistate modeling (MSM can be used as an extension of survival analysis to incorporate more than two discrete events or states. Multistate models were used to investigate transitions between states of training to qualification as a guide dog or behavioral withdrawal, and from qualification as a guide dog to behavioral withdrawal. Sex, breed (with purebred Labradors and Golden retrievers differing from F1 crosses, and bred by Guide Dogs or not, effected movements between states. We postulate that survival analysis and MSM could be applied to a wide range of behavioral data and key examples are provided.

  6. Toward a qualitative understanding of binge-watching behaviors: A focus group approach.

    Science.gov (United States)

    Flayelle, Maèva; Maurage, Pierre; Billieux, Joël

    2017-12-01

    Background and aims Binge-watching (i.e., seeing multiple episodes of the same TV series in a row) now constitutes a widespread phenomenon. However, little is known about the psychological factors underlying this behavior, as reflected by the paucity of available studies, most merely focusing on its potential harmfulness by applying the classic criteria used for other addictive disorders without exploring the uniqueness of binge-watching. This study thus aimed to take the opposite approach as a first step toward a genuine understanding of binge-watching behaviors through a qualitative analysis of the phenomenological characteristics of TV series watching. Methods A focus group of regular TV series viewers (N = 7) was established to explore a wide range of aspects related to TV series watching (e.g., motives, viewing practices, and related behaviors). Results A content analysis identified binge-watching features across three dimensions: TV series watching motivations, TV series watching engagement, and structural characteristics of TV shows. Most participants acknowledged that TV series watching can become addictive, but they all agreed having trouble recognizing themselves as truly being an "addict." Although obvious connections could be established with substance addiction criteria and symptoms, such parallelism appeared to be insufficient, as several distinctive facets emerged (e.g., positive view, transient overinvolvement, context dependency, and low everyday life impact). Discussion and conclusion The research should go beyond the classic biomedical and psychological models of addictive behaviors to account for binge-watching in order to explore its specificities and generate the first steps toward an adequate theoretical rationale for these emerging problematic behaviors.

  7. ISBP: Understanding the Security Rule of Users' Information-Sharing Behaviors in Partnership.

    Directory of Open Access Journals (Sweden)

    Hongchen Wu

    Full Text Available The rapid growth of social network data has given rise to high security awareness among users, especially when they exchange and share their personal information. However, because users have different feelings about sharing their information, they are often puzzled about who their partners for exchanging information can be and what information they can share. Is it possible to assist users in forming a partnership network in which they can exchange and share information with little worry? We propose a modified information sharing behavior prediction (ISBP model that can help in understanding the underlying rules by which users share their information with partners in light of three common aspects: what types of items users are likely to share, what characteristics of users make them likely to share information, and what features of users' sharing behavior are easy to predict. This model is applied with machine learning techniques in WEKA to predict users' decisions pertaining to information sharing behavior and form them into trustable partnership networks by learning their features. In the experiment section, by using two real-life datasets consisting of citizens' sharing behavior, we identify the effect of highly sensitive requests on sharing behavior adjacent to individual variables: the younger participants' partners are more difficult to predict than those of the older participants, whereas the partners of people who are not computer majors are easier to predict than those of people who are computer majors. Based on these findings, we believe that it is necessary and feasible to offer users personalized suggestions on information sharing decisions, and this is pioneering work that could benefit college researchers focusing on user-centric strategies and website owners who want to collect more user information without raising their privacy awareness or losing their trustworthiness.

  8. ISBP: Understanding the Security Rule of Users' Information-Sharing Behaviors in Partnership.

    Science.gov (United States)

    Wu, Hongchen; Wang, Xinjun

    2016-01-01

    The rapid growth of social network data has given rise to high security awareness among users, especially when they exchange and share their personal information. However, because users have different feelings about sharing their information, they are often puzzled about who their partners for exchanging information can be and what information they can share. Is it possible to assist users in forming a partnership network in which they can exchange and share information with little worry? We propose a modified information sharing behavior prediction (ISBP) model that can help in understanding the underlying rules by which users share their information with partners in light of three common aspects: what types of items users are likely to share, what characteristics of users make them likely to share information, and what features of users' sharing behavior are easy to predict. This model is applied with machine learning techniques in WEKA to predict users' decisions pertaining to information sharing behavior and form them into trustable partnership networks by learning their features. In the experiment section, by using two real-life datasets consisting of citizens' sharing behavior, we identify the effect of highly sensitive requests on sharing behavior adjacent to individual variables: the younger participants' partners are more difficult to predict than those of the older participants, whereas the partners of people who are not computer majors are easier to predict than those of people who are computer majors. Based on these findings, we believe that it is necessary and feasible to offer users personalized suggestions on information sharing decisions, and this is pioneering work that could benefit college researchers focusing on user-centric strategies and website owners who want to collect more user information without raising their privacy awareness or losing their trustworthiness.

  9. Application of Survival Analysis and Multistate Modeling to Understand Animal Behavior: Examples from Guide Dogs.

    Science.gov (United States)

    Asher, Lucy; Harvey, Naomi D; Green, Martin; England, Gary C W

    2017-01-01

    Epidemiology is the study of patterns of health-related states or events in populations. Statistical models developed for epidemiology could be usefully applied to behavioral states or events. The aim of this study is to present the application of epidemiological statistics to understand animal behavior where discrete outcomes are of interest, using data from guide dogs to illustrate. Specifically, survival analysis and multistate modeling are applied to data on guide dogs comparing dogs that completed training and qualified as a guide dog, to those that were withdrawn from the training program. Survival analysis allows the time to (or between) a binary event(s) and the probability of the event occurring at or beyond a specified time point. Survival analysis, using a Cox proportional hazards model, was used to examine the time taken to withdraw a dog from training. Sex, breed, and other factors affected time to withdrawal. Bitches were withdrawn faster than dogs, Labradors were withdrawn faster, and Labrador × Golden Retrievers slower, than Golden Retriever × Labradors; and dogs not bred by Guide Dogs were withdrawn faster than those bred by Guide Dogs. Multistate modeling (MSM) can be used as an extension of survival analysis to incorporate more than two discrete events or states. Multistate models were used to investigate transitions between states of training to qualification as a guide dog or behavioral withdrawal, and from qualification as a guide dog to behavioral withdrawal. Sex, breed (with purebred Labradors and Golden retrievers differing from F1 crosses), and bred by Guide Dogs or not, effected movements between states. We postulate that survival analysis and MSM could be applied to a wide range of behavioral data and key examples are provided.

  10. The utility of simple mathematical models in understanding gene regulatory dynamics

    Science.gov (United States)

    Mackey, Michael C.; Santillán, Moisés; Tyran-Kamińska, Marta; Zeron, Eduardo S.

    2015-01-01

    Abstract In this review, we survey work that has been carried out in the attempts of biomathematicians to understand the dynamic behaviour of simple bacterial operons starting with the initial work of the 1960’s. We concentrate on the simplest of situations, discussing both repressible and inducible systems and then turning to concrete examples related to the biology of the lactose and tryptophan operons. We conclude with a brief discussion of the role of both extrinsic noise and so-called intrinsic noise in the form of translational and/or transcriptional bursting. PMID:25402755

  11. The paths of mortality: how understanding the biology of aging can help explain systems behavior of single cells.

    Science.gov (United States)

    Crane, Matthew M; Kaeberlein, Matt

    2018-04-01

    Aging is a fundamental aspect of life, yet also one of the most confounding. In individual cells, aging results in a progressive decline which affects all organelles and reduces a cell's ability to maintain homeostasis. Because of the interconnected nature of cellular systems, the failure of even a single organelle can have cascading effects. We are just beginning to understand the dramatic physiological changes that occur during aging. Because most aging research has focused on population dynamics, or differences between wild-type and mutant populations, single-cell behavior has been largely overlooked. An open question is whether aging cells are defined by predictable sequences of physiological changes, or whether they proceed along divergent aging trajectories defined by whichever system begins to fail first. Can aging be best characterized by a cell-cycle like model with stereotyped states all cells progress through, or a Waddington landscape with divergent trajectories? Here we present work on understanding the changing physiological states of aging cells, why it will impact systems and synthetic biologists, and how the systems community can contribute significantly to the study of aging.

  12. Understanding Psychosocial and High-Risk Sexual Behaviors Among Detained Juveniles: A Descriptive Study Protocol.

    Science.gov (United States)

    Gates, Madison L; Staples-Horne, Michelle; Cartier, Jeanne; Best, Candace; Walker, Veronica; Schwartz, David; Yoo, Wonsuk

    2015-12-30

    African American women are disproportionately impacted by sexually transmitted infections (STIs), such as chlamydia and gonorrhea, which are known risk factors for human immunodeficiency virus (HIV) infection. STIs, particularly chlamydia and gonorrhea, are even more prevalent among young African American women with a juvenile detention history. The population with experiences with the criminal justice system has greater rates of STIs and is diagnosed more often with mental health issues, often related to sexual abuse or intimate partner violence, compared to peers who have not been detained by law enforcement. Psychosocial factors, especially those related to intimate relationships (ie, the imperativeness of being in a relationship and the power one has in their relationship), have emerged as important explanatory factors for acquiring STIs, including HIV, and a component of risk reduction interventions. To investigate more comprehensively the relationship between psychosocial risk factors and STIs, including HIV, as it relates to reduction and prevention of these diseases. The long-term goal is to improve the effectiveness of evidence-based interventions with a major focus on intimate relationship dynamics. This descriptive study surveys young women (ages 13-17) who have been detained (incarcerated) by a department of juvenile justice. In addition to being female and detained, eligibility criteria include being detained longer than 30 days and being free of cognitive impairments. This study will include young women from one juvenile detention center. The primary outcomes to be measured are STI knowledge, intimate relationship dynamics (ie, imperativeness and power), and high-risk sexual behaviors. High-risk sexual behaviors will be assessed using data extracted from health records. Preliminarily, we have received assent from 26 primarily young African American women. The majority of participants (81%) had inadequate knowledge about STIs, 52% perceived a lack of

  13. Toward a Mechanics of Adaptive Behavior: Evolutionary Dynamics and Matching Theory Statics

    Science.gov (United States)

    McDowell, J. J.; Popa, Andrei

    2010-01-01

    One theory of behavior dynamics instantiates the idea that behavior evolves in response to selection pressure from the environment in the form of reinforcement. This computational theory implements Darwinian principles of selection, reproduction, and mutation, which operate on a population of potential behaviors by means of a genetic algorithm.…

  14. BEHAVIOR OF STEEL DP 600 UNDER DYNAMIC CONDITIONS

    Directory of Open Access Journals (Sweden)

    Miroslav Német

    2014-01-01

    Full Text Available Normal 0 21 false false false MicrosoftInternetExplorer4 Dynamic tensile testing of sheet steels is becoming more important. Experimental dynamic tensile technique is depending on the strain rate. For experiments was used two testing method servo hydraulic and single bar method. Experiments was realized on steel grade DP 600. Steel were performed and evaluated static and dynamic tests. Was investigated substructure in static and dynamic loading conditions.

  15. Asymmetric Dynamic Attunement of Speech and Gestures in the Construction of Children's Understanding.

    Science.gov (United States)

    De Jonge-Hoekstra, Lisette; Van der Steen, Steffie; Van Geert, Paul; Cox, Ralf F A

    2016-01-01

    As children learn they use their speech to express words and their hands to gesture. This study investigates the interplay between real-time gestures and speech as children construct cognitive understanding during a hands-on science task. 12 children (M = 6, F = 6) from Kindergarten (n = 5) and first grade (n = 7) participated in this study. Each verbal utterance and gesture during the task were coded, on a complexity scale derived from dynamic skill theory. To explore the interplay between speech and gestures, we applied a cross recurrence quantification analysis (CRQA) to the two coupled time series of the skill levels of verbalizations and gestures. The analysis focused on (1) the temporal relation between gestures and speech, (2) the relative strength and direction of the interaction between gestures and speech, (3) the relative strength and direction between gestures and speech for different levels of understanding, and (4) relations between CRQA measures and other child characteristics. The results show that older and younger children differ in the (temporal) asymmetry in the gestures-speech interaction. For younger children, the balance leans more toward gestures leading speech in time, while the balance leans more toward speech leading gestures for older children. Secondly, at the group level, speech attracts gestures in a more dynamically stable fashion than vice versa, and this asymmetry in gestures and speech extends to lower and higher understanding levels. Yet, for older children, the mutual coupling between gestures and speech is more dynamically stable regarding the higher understanding levels. Gestures and speech are more synchronized in time as children are older. A higher score on schools' language tests is related to speech attracting gestures more rigidly and more asymmetry between gestures and speech, only for the less difficult understanding levels. A higher score on math or past science tasks is related to less asymmetry between gestures and

  16. Asymmetric dynamic attunement of speech and gestures in the construction of children’s understanding

    Directory of Open Access Journals (Sweden)

    Lisette eDe Jonge-Hoekstra

    2016-03-01

    Full Text Available As children learn they use their speech to express words and their hands to gesture. This study investigates the interplay between real-time gestures and speech as children construct cognitive understanding during a hands-on science task. 12 children (M = 6, F = 6 from Kindergarten (n = 5 and first grade (n = 7 participated in this study. Each verbal utterance and gesture during the task were coded, on a complexity scale derived from dynamic skill theory. To explore the interplay between speech and gestures, we applied a cross recurrence quantification analysis (CRQA to the two coupled time series of the skill levels of verbalizations and gestures. The analysis focused on 1 the temporal relation between gestures and speech, 2 the relative strength and direction of the interaction between gestures and speech, 3 the relative strength and direction between gestures and speech for different levels of understanding, and 4 relations between CRQA measures and other child characteristics. The results show that older and younger children differ in the (temporal asymmetry in the gestures-speech interaction. For younger children, the balance leans more towards gestures leading speech in time, while the balance leans more towards speech leading gestures for older children. Secondly, at the group level, speech attracts gestures in a more dynamically stable fashion than vice versa, and this asymmetry in gestures and speech extends to lower and higher understanding levels. Yet, for older children, the mutual coupling between gestures and speech is more dynamically stable regarding the higher understanding levels. Gestures and speech are more synchronized in time as children are older. A higher score on schools’ language tests is related to speech attracting gestures more rigidly and more asymmetry between gestures and speech, only for the less difficult understanding levels. A higher score on math or past science tasks is related to less asymmetry between

  17. There's a World Going on Underground: Imaging Technologies to Understand Root Growth Dynamics and Rhizosphere Interactions

    Science.gov (United States)

    Topp, C. N.

    2016-12-01

    Our ability to harness the power of plant genomics for basic and applied science depends on how well and how fast we can quantify the phenotypic ramifications of genetic variation. Plants can be considered from many vantage points: at scales from cells to organs, over the course of development or evolution, and from biophysical, physiological, and ecological perspectives. In all of these ways, our understanding of plant form and function is greatly limited by our ability to study subterranean structures and processes. The limitations to accessing this knowledge are well known - soil is opaque, roots are morphologically complex, and root growth can be heavily influenced by a myriad of environmental factors. Nonetheless, recent technological innovations in imaging science have generated a renewed focus on roots and thus new opportunities to understand the plant as a whole. The Topp Lab is interested in crop root system growth dynamics and function in response to environmental stresses such as drought, rhizosphere interactions, and as a consequence of artificial selection for agronomically important traits such as nitrogen uptake and high plant density. Studying roots requires the development of imaging technologies, computational infrastructure, and statistical methods that can capture and analyze morphologically complex networks over time and at high-throughput. The lab uses several imaging tools (optical, X-ray CT, PET, etc.) along with quantitative genetics and molecular biology to understand the dynamics of root growth and physiology. We aim to understand the relationships among root traits that can be effectively measured both in controlled laboratory environments and in the field, and to identify genes and gene networks that control root, and ultimately whole plant architectural features useful for crop improvement.

  18. Making Sense of Dynamic Systems: How Our Understanding of Stocks and Flows Depends on a Global Perspective

    Science.gov (United States)

    Fischer, Helen; Gonzalez, Cleotilde

    2016-01-01

    Stocks and flows (SF) are building blocks of dynamic systems: Stocks change through inflows and outflows, such as our bank balance changing with withdrawals and deposits, or atmospheric CO[subscript 2] with absorptions and emissions. However, people make systematic errors when trying to infer the behavior of dynamic systems, termed SF failure,…

  19. Dynamical behavior of X-ray spectra from Markarian 766

    Energy Technology Data Exchange (ETDEWEB)

    Liebmann, A. C.; Tsuruta, S. [Department of Physics, Montana State University, Bozeman, MT 59717 (United States); Haba, Y.; Kunieda, H. [Department of Physics, Nagoya University, Furo-co, Chikusa-Ku, Nagoya 464-8602 (Japan); Takahashi, M. [Department of Physics and Astronomy, Aichi University of Education, Kariya, Aichi 448-8543 (Japan); Takahashi, R., E-mail: liebmann@physics.montana.edu, E-mail: uphst@gemini.oscs.montana.edu, E-mail: haba@u.phys.nagoya-u.ac.jp, E-mail: kunieda@u.phys.nagoya-u.ac.jp, E-mail: takahasi@phyas.aichi-edu.ac.jp, E-mail: rohta@riken.jp [Department of Natural and Physical Sciences, Tomakomai National College of Technology, Tomakomai 0591-1257 (Japan)

    2014-01-01

    Mrk 766, a bright narrow-line Seyfert 1, has been observed eight times by the XMM-Newton satellite. We carried out the analysis of the composite data from all of these observations together by applying a dynamical method. Through this analysis, we noted a longer timescale variability in addition to rapid short-time variability. This longer term variability is manifested by the presence of two distinct branches in flux-flux plots. Moreover, the data show the presence of absorbing material whose average thickness decreases gradually from ∼2 × 10{sup 23} cm{sup –2} during the dim state to ∼10{sup 22} cm{sup –2} as the source brightens to brighter states. To explain this longer timescale behavior and others already found self-consistently, we offer a promising model. In this model, the source is dim when a small emission region is covered by a small, denser portion of a partial-covering cloud; the source brightens as it becomes larger and covered predominantly by a less dense, larger region of the covering cloud. The short rapid variability, in contrast, is consistent with the highly variable power-law component from the coronal primary emission region, which is superimposed onto a less variable, ionized relativistic reflection component. Last, a possible presence of some unique soft flares is suggested. Unlike many other flares seen in the light curves, these flares occur only in the 0.3-2.0 keV soft band. These soft flares may be attributed to 'hot spots' on the accretion disk.

  20. Understanding compressive deformation behavior of porous Ti using finite element analysis

    Energy Technology Data Exchange (ETDEWEB)

    Roy, Sandipan; Khutia, Niloy [Department of Aerospace Engineering and Applied Mechanics, Indian Institute of Engineering Science and Technology, Shibpur (India); Das, Debdulal [Department of Metallurgy and Materials Engineering, Indian Institute of Engineering Science and Technology, Shibpur (India); Das, Mitun, E-mail: mitun@cgcri.res.in [Bioceramics and Coating Division, CSIR-Central Glass and Ceramic Research Institute, Kolkata (India); Balla, Vamsi Krishna [Bioceramics and Coating Division, CSIR-Central Glass and Ceramic Research Institute, Kolkata (India); Bandyopadhyay, Amit [W. M. Keck Biomedical Materials Research Laboratory, School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164 (United States); Chowdhury, Amit Roy, E-mail: arcbesu@gmail.com [Department of Aerospace Engineering and Applied Mechanics, Indian Institute of Engineering Science and Technology, Shibpur (India)

    2016-07-01

    In the present study, porous commercially pure (CP) Ti samples with different volume fraction of porosities were fabricated using a commercial additive manufacturing technique namely laser engineered net shaping (LENS™). Mechanical behavior of solid and porous samples was evaluated at room temperature under quasi-static compressive loading. Fracture surfaces of the failed samples were analyzed to determine the failure modes. Finite Element (FE) analysis using representative volume element (RVE) model and micro-computed tomography (CT) based model have been performed to understand the deformation behavior of laser deposited solid and porous CP-Ti samples. In vitro cell culture on laser processed porous CP-Ti surfaces showed normal cell proliferation with time, and confirmed non-toxic nature of these samples. - Highlights: • Porous CP-Ti samples fabricated using additive manufacturing technique • Compressive deformation behavior of porous samples closely matches with micro-CT and RVE based analysis • In vitro studies showed better cell proliferation with time on porous CP-Ti surfaces.

  1. Understanding why low-risk patients accept vaccines: a socio-behavioral approach.

    Science.gov (United States)

    Wiemken, Timothy L; Carrico, Ruth M; Kelley, Robert R; Binford, Laura E; Peyrani, Paula; Ford, Kimbal D; Welch, Verna; Ramirez, Julio A

    2015-12-23

    Vaccines are one of the most important public health interventions. Understanding factors associated with vaccine acceptance is critical. The objectives of this study were to evaluate the impact of the three constructs of the Theory of Planned Behavior (TPB) on the intention to be vaccinated among healthy individuals being seen for pre-travel care, and to evaluate if behavioral intention was associated with vaccine acceptance. We surveyed individuals seeking vaccination at the University of Louisville Vaccine and International Health and Travel Clinic. Linear and two stage least squares regression models were used to define the associations between constructs of the TPB and the intention to be vaccinated, as well as the association between the intention to be vaccinated and vaccine acceptance. A total of 183 individuals were included in the analysis. None of the constructs of the TPB were associated with intention to be vaccinated. Behavioral intention was not associated with vaccination acceptance. This study suggests that the TPB does not predict the intention to get vaccinated among individuals attending our Vaccine and International Health and Travel Clinic. It will be critical to define better predictors of vaccine uptake in healthy, low-risk individuals to increase vaccine acceptance.

  2. Understanding the effects of stress and alcohol cues on motivation for alcohol via behavioral economics.

    Science.gov (United States)

    Amlung, Michael; MacKillop, James

    2014-06-01

    Psychological stress and alcohol cues are common antecedents of both ongoing drinking and relapse. One candidate mechanism of risk from these factors is acute increases in craving, but experimental support for this hypothesis is mixed. Furthermore, the combination of stress and cues has been largely unstudied. The current study employed a behavioral economic approach to investigate the combined roles of psychosocial stress and alcohol cues on motivation for alcohol. In a sample of 84 adult heavy drinkers, we examined the effects of an acute laboratory stress induction and an alcohol cue exposure on subjective craving and stress, arousal, and behavioral economic decision making. Primary dependent measures included an intertemporal cross-commodity multiple-choice procedure (ICCMCP), incorporating both price and delay elements, an alcohol purchase task (APT), measuring alcohol demand, and a monetary delay discounting task, measuring intertemporal choice. The stress induction significantly increased stress, craving, and the incentive value of alcohol on the ICCMCP and APT. Stress-related increases in value on the ICCMCP were mediated by increased alcohol demand. Exposure to alcohol cues only significantly affected craving, APT breakpoint, and arousal. Delay discounting was not affected by either stress or cues. These results reveal unique behavioral economic dimensions of motivation for alcohol following acute stress and an alcohol cue exposure. More broadly, as the first application of this approach to understanding the role of stress in drug motivation, these findings support its utility and potential in future applications. Copyright © 2014 by the Research Society on Alcoholism.

  3. Understanding compressive deformation behavior of porous Ti using finite element analysis

    International Nuclear Information System (INIS)

    Roy, Sandipan; Khutia, Niloy; Das, Debdulal; Das, Mitun; Balla, Vamsi Krishna; Bandyopadhyay, Amit; Chowdhury, Amit Roy

    2016-01-01

    In the present study, porous commercially pure (CP) Ti samples with different volume fraction of porosities were fabricated using a commercial additive manufacturing technique namely laser engineered net shaping (LENS™). Mechanical behavior of solid and porous samples was evaluated at room temperature under quasi-static compressive loading. Fracture surfaces of the failed samples were analyzed to determine the failure modes. Finite Element (FE) analysis using representative volume element (RVE) model and micro-computed tomography (CT) based model have been performed to understand the deformation behavior of laser deposited solid and porous CP-Ti samples. In vitro cell culture on laser processed porous CP-Ti surfaces showed normal cell proliferation with time, and confirmed non-toxic nature of these samples. - Highlights: • Porous CP-Ti samples fabricated using additive manufacturing technique • Compressive deformation behavior of porous samples closely matches with micro-CT and RVE based analysis • In vitro studies showed better cell proliferation with time on porous CP-Ti surfaces

  4. Adsorption behavior of acetone solvent at the HMX crystal faces: A molecular dynamics study.

    Science.gov (United States)

    Liu, Yingzhe; Yu, Tao; Lai, Weipeng; Ma, Yiding; Kang, Ying; Ge, Zhongxue

    2017-06-01

    Molecular dynamics simulations have been performed to understand the adsorption behavior of acetone (AC) solvent at the three surfaces of 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctan (HMX) crystal, i.e. (011), (110), and (020) faces. The simulation results show that the structural features and electrostatic potentials of crystal faces are determined by the HMX molecular packing, inducing distinct mass density distribution, dipole orientation, and diffusion of solvent molecules in the interfacial regions. The solvent adsorption is mainly governed by the van der Waals forces, and the crystal-solvent interaction energies among three systems are ranked as (020)≈(110)>(011). The adsorption sites for solvent incorporation at the crystal surface were found and visualized with the aid of occupancy analysis. A uniform arrangement of adsorption sites is observed at the rough (020) surface as a result of ordered adsorption motif. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. ISTTOK tokamak plasmas influence on a liquid gallium jet dynamic behavior

    International Nuclear Information System (INIS)

    Gomes, R.B.; Silva, C.; Fernandes, H.; Duarte, P.; Nedzelskiy, I.; Lielausis, O.; Klyukin, A.; Platacis, E.

    2011-01-01

    The main concern in using free flowing liquid metals in fusion devices is related to their interaction with magnetic fields. On ISTTOK tokamak, liquid gallium jets are injected deep into the plasma along a vertical direction. The influence of the plasma interaction on the jet has been investigated monitoring the liquid metal behavior using a fast frame camera. A radial shift on its trajectory has been detected and found to depend on the toroidal magnetic field magnitude and principally on the plasma position within the chamber. The analysis performed to understand the dynamics of the jet perturbation by the plasma is presented in this paper. The jet surface temperature increase during this interaction has also been measured, using absolutely calibrated multichannel IR sensors, to evaluate the jet power exhaustion capability.

  6. ISTTOK tokamak plasmas influence on a liquid gallium jet dynamic behavior

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, R.B., E-mail: gomes@ipfn.ist.utl.pt [Associacao EURATOM/IST, Instituto de Plasmas e Fusao Nuclear - Laboratorio Associado, Instituto Superior Tecnico, 1049-001 Lisboa (Portugal); Silva, C.; Fernandes, H.; Duarte, P.; Nedzelskiy, I. [Associacao EURATOM/IST, Instituto de Plasmas e Fusao Nuclear - Laboratorio Associado, Instituto Superior Tecnico, 1049-001 Lisboa (Portugal); Lielausis, O.; Klyukin, A.; Platacis, E. [Association EURATOM/University of Latvia, Institute of Solid State Physics, 8 Kengaraga Str., LV-1063 Riga (Latvia)

    2011-08-01

    The main concern in using free flowing liquid metals in fusion devices is related to their interaction with magnetic fields. On ISTTOK tokamak, liquid gallium jets are injected deep into the plasma along a vertical direction. The influence of the plasma interaction on the jet has been investigated monitoring the liquid metal behavior using a fast frame camera. A radial shift on its trajectory has been detected and found to depend on the toroidal magnetic field magnitude and principally on the plasma position within the chamber. The analysis performed to understand the dynamics of the jet perturbation by the plasma is presented in this paper. The jet surface temperature increase during this interaction has also been measured, using absolutely calibrated multichannel IR sensors, to evaluate the jet power exhaustion capability.

  7. Dynamic oceanography determines fine scale foraging behavior of Masked Boobies in the Gulf of Mexico.

    Science.gov (United States)

    Poli, Caroline L; Harrison, Autumn-Lynn; Vallarino, Adriana; Gerard, Patrick D; Jodice, Patrick G R

    2017-01-01

    During breeding, foraging marine birds are under biological, geographic, and temporal constraints. These contraints require foraging birds to efficiently process environmental cues derived from physical habitat features that occur at nested spatial scales. Mesoscale oceanography in particular may change rapidly within and between breeding seasons, and findings from well-studied systems that relate oceanography to seabird foraging may transfer poorly to regions with substantially different oceanographic conditions. Our objective was to examine foraging behavior of a pan-tropical seabird, the Masked Booby (Sula dactylatra), in the understudied Caribbean province, a moderately productive region driven by highly dynamic currents and fronts. We tracked 135 individuals with GPS units during May 2013, November 2013, and December 2014 at a regionally important breeding colony in the southern Gulf of Mexico. We measured foraging behavior using characteristics of foraging trips and used area restricted search as a proxy for foraging events. Among individual attributes, nest stage contributed to differences in foraging behavior whereas sex did not. Birds searched for prey at nested hierarchical scales ranging from 200 m-35 km. Large-scale coastal and shelf-slope fronts shifted position between sampling periods and overlapped geographically with overall foraging locations. At small scales (at the prey patch level), the specific relationship between environmental variables and foraging behavior was highly variable among individuals but general patterns emerged. Sea surface height anomaly and velocity of water were the strongest predictors of area restricted search behavior in random forest models, a finding that is consistent with the characterization of the Gulf of Mexico as an energetic system strongly influenced by currents and eddies. Our data may be combined with tracking efforts in the Caribbean province and across tropical regions to advance understanding of seabird

  8. Dynamic oceanography determines fine scale foraging behavior of Masked Boobies in the Gulf of Mexico

    Science.gov (United States)

    Poli, Caroline L.; Harrison, Autumn-Lynn; Vallarino, Adriana; Gerard, Patrick D.; Jodice, Patrick G.R.

    2017-01-01

    During breeding, foraging marine birds are under biological, geographic, and temporal constraints. These contraints require foraging birds to efficiently process environmental cues derived from physical habitat features that occur at nested spatial scales. Mesoscale oceanography in particular may change rapidly within and between breeding seasons, and findings from well-studied systems that relate oceanography to seabird foraging may transfer poorly to regions with substantially different oceanographic conditions. Our objective was to examine foraging behavior of a pan-tropical seabird, the Masked Booby (Sula dactylatra), in the understudied Caribbean province, a moderately productive region driven by highly dynamic currents and fronts. We tracked 135 individuals with GPS units during May 2013, November 2013, and December 2014 at a regionally important breeding colony in the southern Gulf of Mexico. We measured foraging behavior using characteristics of foraging trips and used area restricted search as a proxy for foraging events. Among individual attributes, nest stage contributed to differences in foraging behavior whereas sex did not. Birds searched for prey at nested hierarchical scales ranging from 200 m—35 km. Large-scale coastal and shelf-slope fronts shifted position between sampling periods and overlapped geographically with overall foraging locations. At small scales (at the prey patch level), the specific relationship between environmental variables and foraging behavior was highly variable among individuals but general patterns emerged. Sea surface height anomaly and velocity of water were the strongest predictors of area restricted search behavior in random forest models, a finding that is consistent with the characterization of the Gulf of Mexico as an energetic system strongly influenced by currents and eddies. Our data may be combined with tracking efforts in the Caribbean province and across tropical regions to advance understanding of seabird

  9. Dynamic oceanography determines fine scale foraging behavior of Masked Boobies in the Gulf of Mexico.

    Directory of Open Access Journals (Sweden)

    Caroline L Poli

    Full Text Available During breeding, foraging marine birds are under biological, geographic, and temporal constraints. These contraints require foraging birds to efficiently process environmental cues derived from physical habitat features that occur at nested spatial scales. Mesoscale oceanography in particular may change rapidly within and between breeding seasons, and findings from well-studied systems that relate oceanography to seabird foraging may transfer poorly to regions with substantially different oceanographic conditions. Our objective was to examine foraging behavior of a pan-tropical seabird, the Masked Booby (Sula dactylatra, in the understudied Caribbean province, a moderately productive region driven by highly dynamic currents and fronts. We tracked 135 individuals with GPS units during May 2013, November 2013, and December 2014 at a regionally important breeding colony in the southern Gulf of Mexico. We measured foraging behavior using characteristics of foraging trips and used area restricted search as a proxy for foraging events. Among individual attributes, nest stage contributed to differences in foraging behavior whereas sex did not. Birds searched for prey at nested hierarchical scales ranging from 200 m-35 km. Large-scale coastal and shelf-slope fronts shifted position between sampling periods and overlapped geographically with overall foraging locations. At small scales (at the prey patch level, the specific relationship between environmental variables and foraging behavior was highly variable among individuals but general patterns emerged. Sea surface height anomaly and velocity of water were the strongest predictors of area restricted search behavior in random forest models, a finding that is consistent with the characterization of the Gulf of Mexico as an energetic system strongly influenced by currents and eddies. Our data may be combined with tracking efforts in the Caribbean province and across tropical regions to advance

  10. Improved Understanding of Implosion Symmetry through New Experimental Techniques Connecting Hohlraum Dynamics with Laser Beam Deposition

    Science.gov (United States)

    Ralph, Joseph; Salmonson, Jay; Dewald, Eduard; Bachmann, Benjamin; Edwards, John; Graziani, Frank; Hurricane, Omar; Landen, Otto; Ma, Tammy; Masse, Laurent; MacLaren, Stephen; Meezan, Nathan; Moody, John; Parrilla, Nicholas; Pino, Jesse; Sacks, Ryan; Tipton, Robert

    2017-10-01

    Understanding what affects implosion symmetry has been a challenge for scientists designing indirect drive inertial confinement fusion experiments on the National Ignition Facility (NIF). New experimental techniques and data analysis have been employed aimed at improving our understanding of the relationship between hohlraum dynamics and implosion symmetry. Thin wall imaging data allows for time-resolved imaging of 10 keV Au l-band x-rays providing for the first time on the NIF, a spatially resolved measurement of laser deposition with time. In the work described here, we combine measurements from the thin wall imaging with time resolved views of the interior of the hohlraum. The measurements presented are compared to hydrodynamic simulations as well as simplified physics models. The goal of this work is to form a physical picture that better explains the relationship of the hohlraum dynamics and capsule ablator on laser beam propagation and implosion symmetry. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344.

  11. Future Challenges in Heterogeneous Catalysis: Understanding Catalysts under Dynamic Reaction Conditions.

    Science.gov (United States)

    Kalz, Kai F; Kraehnert, Ralph; Dvoyashkin, Muslim; Dittmeyer, Roland; Gläser, Roger; Krewer, Ulrike; Reuter, Karsten; Grunwaldt, Jan-Dierk

    2017-01-09

    In the future, (electro-)chemical catalysts will have to be more tolerant towards a varying supply of energy and raw materials. This is mainly due to the fluctuating nature of renewable energies. For example, power-to-chemical processes require a shift from steady-state operation towards operation under dynamic reaction conditions. This brings along a number of demands for the design of both catalysts and reactors, because it is well-known that the structure of catalysts is very dynamic. However, in-depth studies of catalysts and catalytic reactors under such transient conditions have only started recently. This requires studies and advances in the fields of 1) operando spectroscopy including time-resolved methods, 2) theory with predictive quality, 3) kinetic modelling, 4) design of catalysts by appropriate preparation concepts, and 5) novel/modular reactor designs. An intensive exchange between these scientific disciplines will enable a substantial gain of fundamental knowledge which is urgently required. This concept article highlights recent developments, challenges, and future directions for understanding catalysts under dynamic reaction conditions.

  12. Understanding the Chronology and Occupation Dynamics of Oversized Pit Houses in the Southern Brazilian Highlands

    Science.gov (United States)

    Gregorio de Souza, Jonas; Robinson, Mark; Corteletti, Rafael; Cárdenas, Macarena Lucia; Wolf, Sidnei; Iriarte, José; Mayle, Francis; DeBlasis, Paulo

    2016-01-01

    A long held view about the occupation of southern proto-Jê pit house villages of the southern Brazilian highlands is that these sites represent cycles of long-term abandonment and reoccupation. However, this assumption is based on an insufficient number of radiocarbon dates for individual pit houses. To address this problem, we conducted a programme of comprehensive AMS radiocarbon dating and Bayesian modelling at the deeply stratified oversized pit House 1, Baggio I site (Cal. A.D. 1395–1650), Campo Belo do Sul, Santa Catarina state, Brazil. The stratigraphy of House 1 revealed an unparalleled sequence of twelve well preserved floors evidencing a major change in occupation dynamics including five completely burnt collapsed roofs. The results of the radiocarbon dating allowed us to understand for the first time the occupation dynamics of an oversized pit house in the southern Brazilian highlands. The Bayesian model demonstrates that House 1 was occupied for over two centuries with no evidence of major periods of abandonment, calling into question previous models of long-term abandonment. In addition, the House 1 sequence allowed us to tie transformations in ceramic style and lithic technology to an absolute chronology. Finally, we can provide new evidence that the emergence of oversized domestic structures is a relatively recent phenomenon among the southern proto-Jê. As monumental pit houses start to be built, small pit houses continue to be inhabited, evidencing emerging disparities in domestic architecture after AD 1000. Our research shows the importance of programmes of intensive dating of individual structures to understand occupation dynamics and site permanence, and challenges long held assumptions that the southern Brazilian highlands were home to marginal cultures in the context of lowland South America. PMID:27384341

  13. Mechanistic understanding of human-wildlife conflict through a novel application of dynamic occupancy models.

    Science.gov (United States)

    Goswami, Varun R; Medhi, Kamal; Nichols, James D; Oli, Madan K

    2015-08-01

    Crop and livestock depredation by wildlife is a primary driver of human-wildlife conflict, a problem that threatens the coexistence of people and wildlife globally. Understanding mechanisms that underlie depredation patterns holds the key to mitigating conflicts across time and space. However, most studies do not consider imperfect detection and reporting of conflicts, which may lead to incorrect inference regarding its spatiotemporal drivers. We applied dynamic occupancy models to elephant crop depredation data from India between 2005 and 2011 to estimate crop depredation occurrence and model its underlying dynamics as a function of spatiotemporal covariates while accounting for imperfect detection of conflicts. The probability of detecting conflicts was consistently <1.0 and was negatively influenced by distance to roads and elevation gradient, averaging 0.08-0.56 across primary periods (distinct agricultural seasons within each year). The probability of crop depredation occurrence ranged from 0.29 (SE 0.09) to 0.96 (SE 0.04). The probability that sites raided by elephants in primary period t would not be raided in primary period t + 1 varied with elevation gradient in different seasons and was influenced negatively by mean rainfall and village density and positively by distance to forests. Negative effects of rainfall variation and distance to forests best explained variation in the probability that sites not raided by elephants in primary period t would be raided in primary period t + 1. With our novel application of occupancy models, we teased apart the spatiotemporal drivers of conflicts from factors that influence how they are observed, thereby allowing more reliable inference on mechanisms underlying observed conflict patterns. We found that factors associated with increased crop accessibility and availability (e.g., distance to forests and rainfall patterns) were key drivers of elephant crop depredation dynamics. Such an understanding is essential for

  14. Dynamic behaviors of a broad-area diode laser with lateral-mode-selected external feedback

    DEFF Research Database (Denmark)

    Chi, Mingjun; Petersen, Paul Michael

    2014-01-01

    In this paper, we investigate the dynamics of a BAL with lateral-mode selected external feedback experimentally by measuring the far-field profile, intensity noise spectrum and time series of the output beam. The mode-selection is achieved by adjusting a stripe mirror at the pseudo far-field plane....... Different dynamic behaviors are observed when different lateral modes are selected. When the mirror is aligned correctly and high-order modes are selected, in most of the cases periodic dynamics of the output power corresponding to a single roundtrip external-cavity loop is observed, but the dynamic...... behavior disappears in some case; when the zero-order mode is selected, periodic dynamics corresponding to a double roundtrip external-cavity loop is observed. When the stripe mirror is not aligned perfectly, a dynamic behavior like pulse-package oscillations is observed: a periodic oscillated output...

  15. Fractured Identity: A Framework for Understanding Young Asian American Women's Self-harm and Suicidal Behaviors.

    Science.gov (United States)

    Hahm, Hyeouk Chris; Gonyea, Judith G; Chiao, Christine; Koritsanszky, Luca Anna

    2014-01-01

    Despite the high suicide rate among young Asian American women, the reasons for this phenomenon remain unclear. This qualitative study explored the family experiences of 16 young Asian American women who are children of immigrants and report a history of self-harm and/or suicidal behaviors. Our findings suggest that the participants experienced multiple types of "disempowering parenting styles" that are characterized as: abusive, burdening, culturally disjointed, disengaged, and gender-prescriptive parenting. Tied to these family dynamics is the double bind that participants suffer. Exposed to multiple types of negative parenting, the women felt paralyzed by opposing forces, caught between a deep desire to satisfy their parents' expectations as well as societal expectations and to simultaneously rebel against the image of "the perfect Asian woman." Torn by the double bind, these women developed a "fractured identity," which led to the use of "unsafe coping" strategies. Trapped in a "web of pain," the young women suffered alone and engaged in self-harm and suicidal behaviors.

  16. Understanding the dynamic interactions driving Zambian health centre performance: a case-based health systems analysis

    Science.gov (United States)

    Topp, Stephanie M; Chipukuma, Julien M; Hanefeld, Johanna

    2015-01-01

    Background Despite being central to achieving improved population health outcomes, primary health centres in low- and middle-income settings continue to underperform. Little research exists to adequately explain how and why this is the case. This study aimed to test the relevance and usefulness of an adapted conceptual framework for improving our understanding of the mechanisms and causal pathways influencing primary health centre performance. Methods A theory-driven, case-study approach was adopted. Four Zambian health centres were purposefully selected with case data including health-care worker interviews (n = 60); patient interviews (n = 180); direct observation of facility operations (2 weeks/centre) and key informant interviews (n = 14). Data were analysed to understand how the performance of each site was influenced by the dynamic interactions between system ‘hardware’ and ‘software’ acting on mechanisms of accountability. Findings Structural constraints including limited resources created challenging service environments in which work overload and stockouts were common. Health workers’ frustration with such conditions interacted with dissatisfaction with salary levels eroding service values and acting as a catalyst for different forms of absenteeism. Such behaviours exacerbated patient–provider ratios and increased the frequency of clinical and administrative shortcuts. Weak health information systems and lack of performance data undermined providers’ answerability to their employer and clients, and a lack of effective sanctions undermined supervisors’ ability to hold providers accountable for these transgressions. Weak answerability and enforceability contributed to a culture of impunity that masked and condoned weak service performance in all four sites. Conclusions Health centre performance is influenced by mechanisms of accountability, which are in turn shaped by dynamic interactions between system hardware and system software. Our

  17. Tool use ability depends on understanding of functional dynamics and not specific joint contribution profiles

    Directory of Open Access Journals (Sweden)

    Ross eParry

    2014-04-01

    Full Text Available Researchers in cognitive neuroscience have become increasingly interested in how different aspects of tool use are integrated and represented by the brain. Comparatively less attention has been directed towards tool use actions themselves and how effective tool use behaviors are coordinated. In response, we take this opportunity to consider the mechanical principles of tool use actions and their relationship to motor learning. Using kinematic analysis, we examine both functional dynamics and joint contribution profiles of subjects with different levels of experience in a primordial percussive task. Our results show that the ability to successfully produce stone flakes using the Oldowan method did not correspond with any particular joint contribution profile. Rather, expertise in this tool use action was principally associated with the subject’s ability to regulate the functional parameters that define the task itself.

  18. Collaborative Research. Damage and Burst Dynamics in Failure of Complex Geomaterials. A Statistical Physics Approach to Understanding the Complex Emergent Dynamics in Near Mean-Field Geological Materials

    Energy Technology Data Exchange (ETDEWEB)

    Rundle, John B. [Univ. of California, Davis, CA (United States); Klein, William [Boston Univ., MA (United States)

    2015-09-29

    We have carried out research to determine the dynamics of failure in complex geomaterials, specifically focusing on the role of defects, damage and asperities in the catastrophic failure processes (now popularly termed “Black Swan events”). We have examined fracture branching and flow processes using models for invasion percolation, focusing particularly on the dynamics of bursts in the branching process. We have achieved a fundamental understanding of the dynamics of nucleation in complex geomaterials, specifically in the presence of inhomogeneous structures.

  19. Comparison of MHD simulation codes for understanding nonlinear ELMs dynamics in KSTAR H-mode plasma

    Science.gov (United States)

    Kim, M.; Lee, J.; Park, H. K.; Yun, G. S.; Xu, X.; Jardin, S. C.; Becoulet, M.

    2017-10-01

    KSTAR electron cyclotron emission imaging (ECEI) systems have contributed to understanding the fundamental physics of ELMs by high-quality 2D and quasi-3D images of ELMs. However, in the highly nonlinear phase of ELM dynamics, the interpretation of ECE signals becomes complicated intrinsically. Theoretical and numerical approaches are necessary to enhance the understanding of ELM physics. Well-established MHD codes (BOUT + + , JOREK, and M3D-C1) are introduced for comparative study with the observations. The nonlinear solutions are obtained using the same equilibrium of the KSTAR H-mode plasma. Each code shows the partial difference in mode evolution, probably, due to the difference in optimized operation window of initial conditions. The nonlinear simulation results show that low- n (n qualitatively matches with the recent ECEI observation just before ELM-crash, or excitation of non-modal solitary perturbation (typically, n = 1) which is highly localized in poloidal and toroidal. Regardless of differences in details, qualitative similarity can provide inspiration to understand the triggering of ELM-crash. This work is supported by NRF of Korea under Contract No. NRF-2014M1A7A1A03029865.

  20. Chaotic Dynamics of Cage Behavior in a High-Speed Cylindrical Roller Bearing

    Directory of Open Access Journals (Sweden)

    Long Chen

    2016-01-01

    Full Text Available This paper presents a mathematical model to investigate the nonlinear dynamic behavior of cage in high-speed cylindrical bearing. Variations of cage behavior due to varying cage eccentricity and cage guidance gap are observed. Hydrodynamic behavior in cage contacts is taken into consideration for a more realistic calculation of acting forces owing to high working speed. Analysis of real-time cage dynamic behavior on radial plane is carried out using chaos theory based on the theoretical and mathematical model established in the paper. The analytical results of this paper provide a solid foundation for designing and manufacturing of high-speed cylindrical roller bearing.

  1. Newtonian chimpanzees? A molecular dynamics approach to understanding decision-making by wild chimpanzees

    Science.gov (United States)

    Westley, Matthew; Sen, Surajit; Sinha, Anindya

    2014-07-01

    In this study, we computationally investigate decision-making by individuals and the ensuing social structure of a primate species, chimpanzees, using Newton's equations of classical mechanics, as opposed to agentbased analyses in which individual chimpanzees make independent decisions. Our model uses molecular dynamics simulation techniques to solve Newton's equations and is able to approximate the movements of female and male chimpanzees, especially in relation to the available food resources, in a manner that is consistent with their observed behavior in natural habitats. It is noteworthy that our Newtonian dynamics-based model may allow us to make certain specific observations of their behaviour, some of which may be difficult to achieve through agent-based modelling exercises or even field studies. Chimpanzees tend to live in fission-fusion social groups, with varying number of individuals, in which both females and males tend to display intrasexual competition for valuable food resources while the males also compete for oestrus females. Most populations of the species are also restricted to a small range of habitats, a clear indication that they are especially vulnerable to the availability and distribution of food sources. With reasonable assumptions of chimpanzee behaviour, we have been able to analyse the clustering behaviour of individuals in relation to local food sources as also patterns of their migration across groups. Our simulated results are qualitatively consistent with field observations conducted on a particular semi-isolated population of chimpanzees in Bossou, Guinea, in western Africa.

  2. Applied Behavior Analysis, Autism, and Occupational Therapy: A Search for Understanding.

    Science.gov (United States)

    Welch, Christie D; Polatajko, H J

    2016-01-01

    Occupational therapists strive to be mindful, competent practitioners and continuously look for ways to improve practice. Applied behavior analysis (ABA) has strong evidence of effectiveness in helping people with autism achieve goals, yet it does not seem to be implemented in occupational therapy practice. To better understand whether ABA could be an evidence-based option to expand occupational therapy practice, the authors conducted an iterative, multiphase investigation of relevant literature. Findings suggest that occupational therapists apply developmental and sensory approaches to autism treatment. The occupational therapy literature does not reflect any use of ABA despite its strong evidence base. Occupational therapists may currently avoid using ABA principles because of a perception that ABA is not client centered. ABA principles and occupational therapy are compatible, and the two could work synergistically. Copyright © 2016 by the American Occupational Therapy Association, Inc.

  3. Understanding Information Seeking Behavior of Indonesian Postgraduate Students in Malaysian Universities: An Empirical Study

    Directory of Open Access Journals (Sweden)

    Muhammad Subhan

    2013-12-01

    Full Text Available Abstract : This study investigates Indonesian postgraduate student’s experience at the pre-sessional program of the process of seeking information and the strategies they used throughout the process. The objective is to understand their information seeking behavior particularly academic-related information in order to improve the effectiveness of educational communication in Malaysia higher institutions. Two research questions are addressed: what experiences do pre-sessional students face in the process of information seeking that can be articulated and described? What stages do pre-sessional students experience in the process of information seeking construction? Using the qualitative method, the study found that the pre-sessional students have different patterns in the constructive process of information seeking in two different groups i.e. writing and reading classes. Six stages and four stages of the search process were identified respectively for the two groups.

  4. Analysis of Online Social Networks to Understand Information Sharing Behaviors Through Social Cognitive Theory

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Hong-Jun [ORNL; Tourassi, Georgia [ORNL

    2014-01-01

    Analyzing the contents of online social networks is an effective process for monitoring and understanding peoples behaviors. Since the nature of conversation and information propagation is similar to traditional conversation and learning, one of the popular socio-cognitive methods, social cognitive theory was applied to online social networks to. Two major news topics about colon cancer were chosen to monitor traffic of Twitter messages. The activity of leaders on the issue (i.e., news companies or people will prior Twitter activity on topics related to colon cancer) was monitored. In addition, the activity of followers , people who never discussed the topics before, but replied to the discussions was also monitored. Topics that produce tangible benefits such as positive outcomes from appropriate preventive actions received dramatically more attention and online social media traffic. Such characteristics can be explained with social cognitive theory and thus present opportunities for effective health campaigns.

  5. Analysis of Online Social Networks to Understand Information Sharing Behaviors Through Social Cognitive Theory.

    Science.gov (United States)

    Yoon, Hong-Jun; Tourassi, Georgia

    2014-05-01

    Analyzing the contents of online social networks is an effective process for monitoring and understanding peoples' behaviors. Since the nature of conversation and information propagation is similar to traditional conversation and learning, one of the popular socio-cognitive methods, social cognitive theory was applied to online social networks to. Two major news topics about colon cancer were chosen to monitor traffic of Twitter messages. The activity of "leaders" on the issue (i.e., news companies or people will prior Twitter activity on topics related to colon cancer) was monitored. In addition, the activity of "followers", people who never discussed the topics before, but replied to the discussions was also monitored. Topics that produce tangible benefits such as positive outcomes from appropriate preventive actions received dramatically more attention and online social media traffic. Such characteristics can be explained with social cognitive theory and thus present opportunities for effective health campaigns.

  6. Correlation between dynamic wetting behavior and chemical components of thermally modified wood

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wang; Zhu, Yuan; Cao, Jinzhen, E-mail: caoj@bjfu.edu.cn; Sun, Wenjing

    2015-01-01

    Highlights: • We studied the dynamic wetting behavior of thermally modified wood by wetting models. • We found lower wetting speed of water droplets on thermally modified wood surface. • Dynamic wetting behavior and surface chemical components show a strong correlation. - Abstract: In order to investigate the dynamic wetting behavior of thermally modified wood, Cathay poplar (Populus cathayana Rehd.) and Scots pine (Pinus sylvestris L.) samples were thermally modified in an oven at 160, 180, 200, 220 or 240 °C for 4 h in this study. The dynamic contact angles and droplet volumes of water droplets on modified and unmodified wood surfaces were measured by sessile drop method, and their changing rates (expression index: K value and wetting slope) calculated by wetting models were illustrated for mapping the dynamic wetting process. The surface chemical components were also measured by X-ray photoelectron spectroscopy analysis (XPS), thus the relationship between dynamic wetting behavior and chemical components of thermally modified wood were determined. The results indicated that thermal modification was capable of decreasing the dynamic wettability of wood, expressed in lowing spread and penetration speed of water droplets on wood surfaces. This change was more obvious with the increased heating temperature. The K values varied linearly with the chemical components parameter (mass loss, O/C ratio, and C{sub 1}/C{sub 2} ratio), indicating a strong correlation between dynamic wetting behavior and chemical components of thermally modified wood.

  7. Correlation between dynamic wetting behavior and chemical components of thermally modified wood

    International Nuclear Information System (INIS)

    Wang, Wang; Zhu, Yuan; Cao, Jinzhen; Sun, Wenjing

    2015-01-01

    Highlights: • We studied the dynamic wetting behavior of thermally modified wood by wetting models. • We found lower wetting speed of water droplets on thermally modified wood surface. • Dynamic wetting behavior and surface chemical components show a strong correlation. - Abstract: In order to investigate the dynamic wetting behavior of thermally modified wood, Cathay poplar (Populus cathayana Rehd.) and Scots pine (Pinus sylvestris L.) samples were thermally modified in an oven at 160, 180, 200, 220 or 240 °C for 4 h in this study. The dynamic contact angles and droplet volumes of water droplets on modified and unmodified wood surfaces were measured by sessile drop method, and their changing rates (expression index: K value and wetting slope) calculated by wetting models were illustrated for mapping the dynamic wetting process. The surface chemical components were also measured by X-ray photoelectron spectroscopy analysis (XPS), thus the relationship between dynamic wetting behavior and chemical components of thermally modified wood were determined. The results indicated that thermal modification was capable of decreasing the dynamic wettability of wood, expressed in lowing spread and penetration speed of water droplets on wood surfaces. This change was more obvious with the increased heating temperature. The K values varied linearly with the chemical components parameter (mass loss, O/C ratio, and C 1 /C 2 ratio), indicating a strong correlation between dynamic wetting behavior and chemical components of thermally modified wood

  8. Characterizing dynamic behavior of carbon dioxide nano-jets using molecular dynamics simulation

    Science.gov (United States)

    Huang, Pei-Hsing; Chou, Chuen-Shii; Hung, Shang-Chao; Jhan, Jhih-Wei

    2017-12-01

    This paper reports on the use of molecular dynamics (MD) simulations to elucidate the dynamic behavior of CO2 through a Graphene/Au(111) nano-injector. We investigated the effects of jet diameter ( d), system temperature ( T), and the extrusion velocity ( v) of a graphite piston plate on the jet pattern, system pressure ( P), and the number of molecules ( N m) in the outflow. Simulation results show that the combined effects of high v and small d induced a larger jet angle, resulting in an increase in the number of CO2 molecules attached to the surface of the outlet. Increasing d enhanced the formation of the T-junction molecular geometry of CO2 molecules, due to the effects of electrostatic attraction between C (0.5888 e) and O (- 0.2944 e) of CO2, which caused the formation of larger agglomerations of CO2 molecules in the vicinity of the nano-injector orifice in the final extrusion stage. The increase in P within the cylinder of the nano-injector was more pronounced during middle and final stages of extrusion, compared with the effects observed during the initial stages. Despite the fact that N m increased noticeably with an increase in T, the value of N m at d = 1.5 nm and T ≥ 300 K greatly exceeded that at d = 1.0 nm and T = 500 K, regardless of the value of v. The numerical simulations presented in this study could be helpful in the design of nano-injectors for a diversity of applications associated with engineering systems and biomedicine at the nano-scale.

  9. Understanding social and behavioral drivers and impacts of air quality sensor use.

    Science.gov (United States)

    Hubbell, Bryan J; Kaufman, Amanda; Rivers, Louie; Schulte, Kayla; Hagler, Gayle; Clougherty, Jane; Cascio, Wayne; Costa, Dan

    2018-04-15

    Lower-cost air quality sensors (hundreds to thousands of dollars) are now available to individuals and communities. This technology is undergoing a rapid and fragmented evolution, resulting in sensors that have uncertain data quality, measure different air pollutants and possess a variety of design attributes. Why and how individuals and communities choose to use sensors is arguably influenced by social context. For example, community experiences with environmental exposures and health effects and related interactions with industry and government can affect trust in traditional air quality monitoring. To date, little social science research has been conducted to evaluate why or how sensors, and sensor data, are used by individuals and communities, or how the introduction of sensors changes the relationship between communities and air quality managers. This commentary uses a risk governance/responsible innovation framework to identify opportunities for interdisciplinary research that brings together social scientists with air quality researchers involved in developing, testing, and deploying sensors in communities. Potential areas for social science research include communities of sensor users; drivers for use of sensors and sensor data; behavioral, socio-political, and ethical implications of introducing sensors into communities; assessing methods for communicating sensor data; and harnessing crowdsourcing capabilities to analyze sensor data. Social sciences can enhance understanding of perceptions, attitudes, behaviors, and other human factors that drive levels of engagement with and trust in different types of air quality data. New transdisciplinary research bridging social sciences, natural sciences, engineering, and design fields of study, and involving citizen scientists working with professionals from a variety of backgrounds, can increase our understanding of air sensor technology use and its impacts on air quality and public health. Published by Elsevier B.V.

  10. Modeling and simulation of the dynamic behavior of portable proton exchange membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Ziegler, C.

    2005-07-01

    In order to analyze the operational behavior, a mathematical model of planar self-breathing fuel cells is developed and validated in Chapter 3 of this thesis. The multicomponent transport of the species is considered as well as the couplings between the transport processes of heat, charge, and mass and the electrochemical reactions. Furthermore, to explain the oxygen mass transport limitation in the porous electrode of the cathode side an agglomerate model for the oxygen reduction reaction is developed. In Chapter 4 the important issue of liquid water generation and transport in PEMFCs is addressed. One of the major tasks when operating this type of fuel cell is avoiding the complete flooding of the PEMFC during operation. A one-dimensional and isothermal model is developed that is based on a coupled system of partial differential equations. The model contains a dynamic and two-phase description of the proton exchange membrane fuel cell. The mass transport in the gas phase and in the liquid phase is considered as well as the phase transition between liquid water and water vapor. The transport of charges and the electrochemical reactions are part of the model. Flooding effects that are caused by liquid water accumulation are described by this model. Moreover, the model contains a time-dependent description of the membrane that accounts for Schroeder's paradox. The model is applied to simulate cyclic voltammograms. Chapter 5 is focused on the dynamic investigation of PEMFC stacks. Understanding the dynamic behavior of fuel cell stacks is important for the operation and control of fuel cell stacks. Using the single cell model of Chapter 3 and the dynamic model of Chapter 4 as basis, a mathematical model of a PEMFC stack is developed. However, due to the complexity of a fuel cell stack, the spatial resolution and dynamic description of the liquid water transport are not accounted for. These restrictions allow for direct comparison between the solution variables of

  11. The dynamic behavior of the exohedral transition metal complexes ...

    Indian Academy of Sciences (India)

    NAIWRIT KARMODAK

    Abstract. The dynamic nature of the exohedral η6- and the η7-complexes of B40 with Cr(CO)3 has been explored using density functional theory. The ab initio molecular dynamic simulations were performed at. 1200 K to investigate the fluxionality of the heptagonal and hexagonal faces of exohedral B40 complexes.

  12. Long term behavior of dynamic equilibria in fluid queuing networks

    NARCIS (Netherlands)

    R. Cominetti (Roberto); J. Correa (José); N.K. Olver (Neil)

    2017-01-01

    textabstractA fluid queuing network constitutes one of the simplest models in which to study flow dynamics over a network. In this model we have a single source-sink pair and each link has a per-time-unit capacity and a transit time. A dynamic equilibrium (or equilibrium flow over time) is a flow

  13. The dynamic behavior of the exohedral transition metal complexes ...

    Indian Academy of Sciences (India)

    Abstract. The dynamic nature of the exohedral η⁶- and the η⁷-complexes of B₄₀ with Cr(CO) ₃ has been explored using density functional theory. The ab initio molecular dynamic simulations were performed at 1200 K to investigate the fluxionality of the heptagonal and hexagonal faces of exohedral B40 complexes.

  14. Advancing our understanding of religion and spirituality in the context of behavioral medicine.

    Science.gov (United States)

    Park, Crystal L; Masters, Kevin S; Salsman, John M; Wachholtz, Amy; Clements, Andrea D; Salmoirago-Blotcher, Elena; Trevino, Kelly; Wischenka, Danielle M

    2017-02-01

    Recognizing and understanding the potentially powerful roles that religiousness and spirituality (RS) may serve in the prevention and amelioration of disease, as well as symptom management and health related quality of life, significantly enhances research and clinical efforts across many areas of behavioral medicine. This article examines the knowledge established to date and suggests advances that remain to be made. We begin with a brief summary of the current knowledge regarding RS as related to three exemplary health conditions: (a) cardiovascular disease; (b) cancer; and, (c) substance abuse. We then focus on particular concerns for future investigations, emphasizing conceptual issues, possible mediators and moderators of relationships or effects, and methodology. Our discussion is framed by a conceptual model that may serve to guide and organize future investigations. This model highlights a number of important issues regarding the study of links between RS and health: (a) RS comprise many diverse constructs, (b) the mechanisms through which RS may influence health outcomes are quite diverse, and (c) a range of different types of health and health relevant outcomes may be influenced by RS. The multidimensional nature of RS and the complexity of related associations with different types of health relevant outcomes present formidable challenges to empirical study in behavioral medicine. These issues are referred to throughout our review and we suggest several solutions to the presented challenges in our summary. We end with a presentation of barriers to be overcome, along with strategies for doing so, and concluding thoughts.

  15. Computational Intelligence-Assisted Understanding of Nature-Inspired Superhydrophobic Behavior.

    Science.gov (United States)

    Zhang, Xia; Ding, Bei; Cheng, Ran; Dixon, Sebastian C; Lu, Yao

    2018-01-01

    In recent years, state-of-the-art computational modeling of physical and chemical systems has shown itself to be an invaluable resource in the prediction of the properties and behavior of functional materials. However, construction of a useful computational model for novel systems in both academic and industrial contexts often requires a great depth of physicochemical theory and/or a wealth of empirical data, and a shortage in the availability of either frustrates the modeling process. In this work, computational intelligence is instead used, including artificial neural networks and evolutionary computation, to enhance our understanding of nature-inspired superhydrophobic behavior. The relationships between experimental parameters (water droplet volume, weight percentage of nanoparticles used in the synthesis of the polymer composite, and distance separating the superhydrophobic surface and the pendant water droplet in adhesive force measurements) and multiple objectives (water droplet contact angle, sliding angle, and adhesive force) are built and weighted. The obtained optimal parameters are consistent with the experimental observations. This new approach to materials modeling has great potential to be applied more generally to aid design, fabrication, and optimization for myriad functional materials.

  16. Advancing our understanding of religion and spirituality in the context of behavioral medicine

    Science.gov (United States)

    Masters, Kevin S.; Salsman, John M.; Wachholtz, Amy; Clements, Andrea D.; Salmoirago-Blotcher, Elena; Trevino, Kelly; Wischenka, Danielle M.

    2016-01-01

    Recognizing and understanding the potentially powerful roles that religiousness and spirituality (RS) may serve in the prevention and amelioration of disease, as well as symptom management and health related quality of life, significantly enhances research and clinical efforts across many areas of behavioral medicine. This article examines the knowledge established to date and suggests advances that remain to be made. We begin with a brief summary of the current knowledge regarding RS as related to three exemplary health conditions: (a) cardiovascular disease; (b) cancer; and, (c) substance abuse. We then focus on particular concerns for future investigations, emphasizing conceptual issues, possible mediators and moderators of relationships or effects, and methodology. Our discussion is framed by a conceptual model that may serve to guide and organize future investigations. This model highlights a number of important issues regarding the study of links between RS and health: (a) RS comprise many diverse constructs, (b) the mechanisms through which RS may influence health outcomes are quite diverse, and (c) a range of different types of health and health relevant outcomes may be influenced by RS. The multidimensional nature of RS and the complexity of related associations with different types of health relevant outcomes present formidable challenges to empirical study in behavioral medicine. These issues are referred to throughout our review and we suggest several solutions to the presented challenges in our summary. We end with a presentation of barriers to be overcome, along with strategies for doing so, and concluding thoughts. PMID:27342616

  17. Using self-determination theory to understand motivation deficits in schizophrenia: the 'why' of motivated behavior.

    Science.gov (United States)

    Gard, David E; Sanchez, Amy H; Starr, Jessica; Cooper, Shanna; Fisher, Melissa; Rowlands, Abby; Vinogradov, Sophia

    2014-07-01

    Self-determination theory (SDT) provides a model for understanding motivation deficits in schizophrenia, and recent research has focused on problems with intrinsic motivation. However, SDT emphasizes that motivated behavior results from three different factors: intrinsic motivators (facilitated by needs for autonomy, competency, and relatedness), extrinsic motivators (towards reward or away from punishment), or when intrinsic and extrinsic motivators are absent or thwarted a disconnect-disengagement occurs resulting in behavior driven by boredom or 'passing time'. Using a novel approach to Ecological Momentary Assessment, we assessed the degree to which people with schizophrenia were motivated by these factors relative to healthy control participants. Forty-seven people with and 41 people without schizophrenia were provided with cell phones and were called four times a day for one week. On each call participants were asked about their goals, and about the most important reason motivating each goal. All responses were coded by independent raters (blind to group and hypotheses) on all SDT motivating factors, and ratings were correlated to patient functioning and symptoms. We found that, relative to healthy participants, people with schizophrenia reported goals that were: (1) less motivated by filling autonomy and competency needs, but equivalently motivated by relatedness; (2) less extrinsically rewarding, but equivalently motivated by punishment; (3) more disconnected-disengaged. Higher disconnected-disengaged goals were significantly associated with higher negative symptoms and lower functioning. These findings indicate several important leverage points for behavioral treatments and suggest the need for vigorous psychosocial intervention focusing on autonomy, competence, and reward early in the course of illness. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Individual killer whale vocal variation during intra-group behavioral dynamics

    Science.gov (United States)

    Grebner, Dawn M.

    calls discussed in Chapter 6 showed that the higher frequency component (HFC) was always associated with sideband 7 (SB7) of the lower frequency component (LFC). Insight into Northern Resident killer whale intra-group vocal dynamics would aid our understanding of vocal behaviors of many other marine mammal species that rely on vocal exchanges for prey capture, group movement or survival. This is the first study to focus on killer whale vocal content and usage as it pertains to intra-group dynamics for (1) mother and offspring separations and (2) for all individuals prior to joining events, as well as (3) individual usage in a diverging pulsed call. It is also the first time the N04 call has been parsed into subtypes.

  19. Understanding and Mastering Dynamics in Computing Grids Processing Moldable Tasks with User-Level Overlay

    CERN Document Server

    Moscicki, Jakub Tomasz

    Scientic communities are using a growing number of distributed systems, from lo- cal batch systems, community-specic services and supercomputers to general-purpose, global grid infrastructures. Increasing the research capabilities for science is the raison d'^etre of such infrastructures which provide access to diversied computational, storage and data resources at large scales. Grids are rather chaotic, highly heterogeneous, de- centralized systems where unpredictable workloads, component failures and variability of execution environments are commonplace. Understanding and mastering the hetero- geneity and dynamics of such distributed systems is prohibitive for end users if they are not supported by appropriate methods and tools. The time cost to learn and use the interfaces and idiosyncrasies of dierent distributed environments is another challenge. Obtaining more reliable application execution times and boosting parallel speedup are important to increase the research capabilities of scientic communities. L...

  20. Repetitive motor behavior: further characterization of development and temporal dynamics.

    Science.gov (United States)

    Muehlmann, Amber M; Bliznyuk, Nikolay; Duerr, Isaac; Lewis, Mark H

    2015-03-01

    Repetitive behaviors are diagnostic for autism spectrum disorders, common in related neurodevelopmental disorders, and normative in typical development. In order to identify factors that mediate repetitive behavior development, it is necessary to characterize the expression of these behaviors from an early age. Extending previous findings, we characterized further the ontogeny of stereotyped motor behavior both in terms of frequency and temporal organization in deer mice. A three group trajectory model provided a good fit to the frequencies of stereotyped behavior across eight developmental time points. Group based trajectory analysis using a measure of temporal organization of stereotyped behavior also resulted in a three group solution. Additionally, as the frequency of stereotyped behavior increased with age, the temporal distribution of stereotyped responses became increasingly regular or organized indicating a strong association between these measures. Classification tree and principal components analysis showed that accurate classification of trajectory group could be done with fewer observations. This ability to identify trajectory group membership earlier in development allows for examination of a wide range of variables, both experiential and biological, to determine their impact on altering the expected trajectory of repetitive behavior across development. Such studies would have important implications for treatment efforts in neurodevelopmental disorders such as autism. © 2015 Wiley Periodicals, Inc.

  1. Himalayan glaciers: understanding contrasting patterns of glacier behavior using multi-temporal satellite imagery

    Science.gov (United States)

    Racoviteanu, A.

    2014-12-01

    High rates of glacier retreat for the last decades are often reported, and believed to be induced by 20th century climate changes. However, regional glacier fluctuations are complex, and depend on a combination of climate and local topography. Furthermore, in ares such as the Hindu-Kush Himalaya, there are concerns about warming, decreasing monsoon precipitation and their impact on local glacier regimes. Currently, the challenge is in understanding the magnitude of feedbacks between large-scale climate forcing and small-scale glacier behavior. Spatio-temporal patterns of glacier distribution are still llimited in some areas of the high Hindu-Kush Himalaya, but multi-temporal satellite imagery has helped fill spatial and temporal gaps in regional glacier parameters in the last decade. Here I present a synopsis of the behavior of glaciers across the Himalaya, following a west to east gradient. In particular, I focus on spatial patterns of glacier parameters in the eastern Himalaya, which I investigate at multi-spatial scales using remote sensing data from declassified Corona, ASTER, Landsat ETM+, Quickbird and Worldview2 sensors. I also present the use of high-resolution imagery, including texture and thermal analysis for mapping glacier features at small scale, which are particularly useful in understanding surface trends of debris-covered glaciers, which are prevalent in the Himalaya. I compare and contrast spatial patterns of glacier area and élévation changes in the monsoon-influenced eastern Himalaya (the Everest region in the Nepal Himalaya and Sikkim in the Indian Himalaya) with other observations from the dry western Indian Himalaya (Ladakh and Lahul-Spiti), both field measurements and remote sensing-based. In the eastern Himalaya, results point to glacier area change of -0.24 % ± 0.08% per year from the 1960's to the 2006's, with a higher rate of retreat in the last decade (-0.43% /yr). Debris-covered glacier tongues show thinning trends of -30.8 m± 39 m

  2. Understanding Action and Adventure Sports Participation-An Ecological Dynamics Perspective.

    Science.gov (United States)

    Immonen, Tuomas; Brymer, Eric; Orth, Dominic; Davids, Keith; Feletti, Francesco; Liukkonen, Jarmo; Jaakkola, Timo

    2017-12-01

    Previous research has considered action and adventure sports using a variety of associated terms and definitions which has led to confusing discourse and contradictory research findings. Traditional narratives have typically considered participation exclusively as the pastime of young people with abnormal characteristics or personalities having unhealthy and pathological tendencies to take risks because of the need for thrill, excitement or an adrenaline 'rush'. Conversely, recent research has linked even the most extreme forms of action and adventure sports to positive physical and psychological health and well-being outcomes. Here, we argue that traditional frameworks have led to definitions, which, as currently used by researchers, ignore key elements constituting the essential merit of these sports. In this paper, we suggest that this lack of conceptual clarity in understanding cognitions, perception and action in action and adventure sports requires a comprehensive explanatory framework, ecological dynamics which considers person-environment interactions from a multidisciplinary perspective. Action and adventure sports can be fundamentally conceptualized as activities which flourish through creative exploration of novel movement experiences, continuously expanding and evolving beyond predetermined environmental, physical, psychological or sociocultural boundaries. The outcome is the emergence of a rich variety of participation styles and philosophical differences within and across activities. The purpose of this paper is twofold: (a) to point out some limitations of existing research on action and adventure sports; (b) based on key ideas from emerging research and an ecological dynamics approach, to propose a holistic multidisciplinary model for defining and understanding action and adventure sports that may better guide future research and practical implications.

  3. Application of network methods for understanding evolutionary dynamics in discrete habitats.

    Science.gov (United States)

    Greenbaum, Gili; Fefferman, Nina H

    2017-06-01

    In populations occupying discrete habitat patches, gene flow between habitat patches may form an intricate population structure. In such structures, the evolutionary dynamics resulting from interaction of gene-flow patterns with other evolutionary forces may be exceedingly complex. Several models describing gene flow between discrete habitat patches have been presented in the population-genetics literature; however, these models have usually addressed relatively simple settings of habitable patches and have stopped short of providing general methodologies for addressing nontrivial gene-flow patterns. In the last decades, network theory - a branch of discrete mathematics concerned with complex interactions between discrete elements - has been applied to address several problems in population genetics by modelling gene flow between habitat patches using networks. Here, we present the idea and concepts of modelling complex gene flows in discrete habitats using networks. Our goal is to raise awareness to existing network theory applications in molecular ecology studies, as well as to outline the current and potential contribution of network methods to the understanding of evolutionary dynamics in discrete habitats. We review the main branches of network theory that have been, or that we believe potentially could be, applied to population genetics and molecular ecology research. We address applications to theoretical modelling and to empirical population-genetic studies, and we highlight future directions for extending the integration of network science with molecular ecology. © 2017 John Wiley & Sons Ltd.

  4. Recent advances in understanding climate, glacier and river dynamics in high mountain Asia

    Science.gov (United States)

    Immerzeel, W.

    2016-12-01

    The water cycle in the Himalaya is poorly understood because of its extreme topography that results in complex interactions between climate, water stored in snow and glaciers and the hydrological processes. Hydrological extremes in the greater Himalayas regularly cause great damage, while high mountain Asia also supplies water to over 25% of the global population. So, the stakes are high and an accurate understanding of the Himalayan water cycle is imperative. The hydrology of the greater Himalayas is only marginally resolved due to the intricacy of monsoon dynamics, the poorly quantified dependence on the cryosphere and the physical constraints of doing research in high-altitude and generally inaccessible terrain. However, in recent years significant scientific advances have been made in field monitoring, modelling and remote sensing and the latest progress and outstanding challenges will be presented for three related fields. First focus will be on recent learnings about high altitude climate dynamics and the interaction between the atmosphere and the extreme mountain topography. Secondly, recent advances in how climate controls key glacio-hydrological processes in high-altitude catchments will be discussed with a particular focus on debris covered glaciers. Thirdly, new developments in glacio-hydrological modelling and approaches to climate change impact assessments will be reviewed. Finally, the outstanding scientific challenges will be synthesized that need to be addressed to fully close the high mountain water cycle and to be able to reduce the uncertainty in future projections of water availability and the occurrence of extreme events in high mountain Asia.

  5. Switching among graphic patterns is governed by oscillatory coordination dynamics: Implications for understanding handwriting.

    Directory of Open Access Journals (Sweden)

    Pier-Giorgio eZanone

    2013-09-01

    Full Text Available Revisiting an original idea by Hollerbach (1981, previous work has established that the production of graphic shapes, assumed to be the blueprint for handwriting, is governed by the dynamics of orthogonal non-linear coupled oscillators. Such dynamics determines few stable coordination patterns, giving rise to a limited set of preferred graphic shapes, namely, four lines and four ellipsoids independent of orientation. The present study investigates the rules of switching among such graphic coordination patterns. Seven participants were required to voluntarily switch within twelve pairs of shapes presented on a graphic tablet. In line with previous theoretical and experimental work on bimanual coordination, results corroborated our hypothesis that the relative stability of the produced coordination patterns determines the time needed for switching: the transition to a more stable pattern was shorter, and inversely. Moreover, switching between patterns with the same orientation but different eccentricities was faster than with a change in orientation. Nonetheless, the switching time covaried strictly with the change in relative phase effected by the transition between two shapes, whether this implied a change in eccentricity or in orientation. These findings suggest a new operational definition of what the (motor units or strokes of handwriting are and shed a novel light on how co-articulation and recruitment of degrees of freedom may occur in graphic skills. They also yield some leads for understanding the acquisition and the neural underpinnings of handwriting.

  6. CALCULATING ROTATING HYDRODYNAMIC AND MAGNETOHYDRODYNAMIC WAVES TO UNDERSTAND MAGNETIC EFFECTS ON DYNAMICAL TIDES

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Xing, E-mail: xing.wei@sjtu.edu.cn [Institute of Natural Sciences and Department of Physics and Astronomy, Shanghai Jiao Tong University (China); Princeton University Observatory, Princeton, NJ 08544 (United States)

    2016-09-01

    To understand magnetic effects on dynamical tides, we study the rotating magnetohydrodynamic (MHD) flow driven by harmonic forcing. The linear responses are analytically derived in a periodic box under the local WKB approximation. Both the kinetic and Ohmic dissipations at the resonant frequencies are calculated, and the various parameters are investigated. Although magnetic pressure may be negligible compared to thermal pressure, the magnetic field can be important for the first-order perturbation, e.g., dynamical tides. It is found that the magnetic field splits the resonant frequency, namely the rotating hydrodynamic flow has only one resonant frequency, but the rotating MHD flow has two, one positive and the other negative. In the weak field regime the dissipations are asymmetric around the two resonant frequencies and this asymmetry is more striking with a weaker magnetic field. It is also found that both the kinetic and Ohmic dissipations at the resonant frequencies are inversely proportional to the Ekman number and the square of the wavenumber. The dissipation at the resonant frequency on small scales is almost equal to the dissipation at the non-resonant frequencies, namely the resonance takes its effect on the dissipation at intermediate length scales. Moreover, the waves with phase propagation that is perpendicular to the magnetic field are much more damped. It is also interesting to find that the frequency-averaged dissipation is constant. This result suggests that in compact objects, magnetic effects on tidal dissipation should be considered.

  7. Understanding the Behavior of the Oligomeric Fractions During Pyrolysis Oils Upgrading

    Science.gov (United States)

    Stankovikj, Filip

    Fast pyrolysis oils represent most viable renewable sources for production of fuels and chemicals, and they could supplement significant portion of the depleting fossil fuels in near future. Progress on their utilization is impeded by their thermal and storage instability, lack of understanding of their complex composition and behavior during upgrading, including the poorly described water soluble fraction (WS). This work offers two new methodologies for simplified, and sensible description of the pyrolysis oils in terms of functional groups and chemical macro-families, augments our understanding of the composition of the WS, and the behavior of the heavy non-volatile fraction during pyrolysis oils stabilization. The concept of analyzing the volatile and non-volatile fraction in terms of functional groups has been introduced, and the quantification power of spectroscopic techniques (FTIR, 1H-NMR, UV fluorescence) for phenols, carbonyl and carboxyl groups was shown. The FT-ICR-MS van Krevelen diagram revealed the importance of dehydration reactions in pyrolysis oils and the presence of "pyrolytic humins" was hypothesized. For the first time the WS was analyzed with plethora of analytical techniques. This lead to proposition of a new characterization scheme based on functional groups, describing 90-100 wt.% of the bio-oils. The structure of idealized "pyrolytic humin" was further described as a random combination of 3-8 units of dehydrated sugars, coniferyl-type phenols, furans, and carboxylic acids attached on a 2,5-dioxo-6-hydroxyhexanal (DHH) backbone rich in carbonyl groups. TG-FTIR studies resulted in defining rules for fitting pyrolysis oils' DTG curves and assignment of TG residue. This second method is reliable for estimation of water content, light volatiles, WS and WIS. Finally, stabilization of two oils was analyzed through the prism of functional groups. Carbonyl and hydroxyl groups interconverted. The first attempt to follow silent 31P-NMR oxygen was

  8. Toward an improved understanding of the role of transpiration in critical zone dynamics

    Science.gov (United States)

    Mitra, B.; Papuga, S. A.

    2012-12-01

    Evapotranspiration (ET) is an important component of the total water balance across any ecosystem. In subalpine mixed-conifer ecosystems, transpiration (T) often dominates the total water flux and therefore improved understanding of T is critical for accurate assessment of catchment water balance and for understanding of the processes that governs the complex dynamics across critical zone (CZ). The interaction between T and plant vegetation not only modulates soil water balance but also influences water transit time and hydrochemical flux - key factors in our understanding of how the CZ evolves and responds. Unlike an eddy covariance system which provides only an integrated ET flux from an ecosystem, a sap flow system can provide an estimate of the T flux from the ecosystem. By isolating T, the ecohydrological drivers of this major water loss from the CZ can be identified. Still, the species composition of mixed-conifer ecosystems vary and the drivers of T associated with each species are expected to be different. Therefore, accurate quantification of T from a mixed-conifer requires knowledge of the unique transpiration dynamics of each of the tree species. Here, we installed a sap flow system within two mixed-conifer study sites of the Jemez River Basin - Santa Catalina Mountains Critical Zone Observatory (JRB - SCM CZO). At both sites, we identified the dominant tree species and installed sap flow sensors on healthy representatives for each of those species. At the JRB CZO site, sap sensors were installed in fir (4) and spruce (4) trees; at the SCM CZO site, sap sensors were installed at white fir (4) and maple (4) and one dead tree. Meteorological data as well as soil temperature (Ts) and soil moisture (θ) at multiple depths were also collected from each of the two sites. Preliminary analysis of two years of sap flux rate at JRB - SCM CZO shows that the environmental drivers of fir, spruce, and maple are different and also vary throughout the year. For JRB fir

  9. Using the Integrative Model of Behavioral Prediction to Understand College Students' STI Testing Beliefs, Intentions, and Behaviors.

    Science.gov (United States)

    Wombacher, Kevin; Dai, Minhao; Matig, Jacob J; Harrington, Nancy Grant

    2018-03-22

    To identify salient behavioral determinants related to STI testing among college students by testing a model based on the integrative model of behavioral (IMBP) prediction. 265 undergraduate students from a large university in the Southeastern US. Formative and survey research to test an IMBP-based model that explores the relationships between determinants and STI testing intention and behavior. Results of path analyses supported a model in which attitudinal beliefs predicted intention and intention predicted behavior. Normative beliefs and behavioral control beliefs were not significant in the model; however, select individual normative and control beliefs were significantly correlated with intention and behavior. Attitudinal beliefs are the strongest predictor of STI testing intention and behavior. Future efforts to increase STI testing rates should identify and target salient attitudinal beliefs.

  10. Cognitive and affective components of mental workload: Understanding the effects of each on human decision making behavior

    Science.gov (United States)

    Nygren, Thomas E.

    1992-01-01

    Human factors and ergonomics researchers have recognized for some time the increasing importance of understanding the role of the construct of mental workload in flight research. Current models of mental workload suggest that it is a multidimensional and complex construct, but one that has proved difficult to measure. Because of this difficulty, emphasis has usually been placed on using direct reports through subjective measures such as rating scales to assess levels of mental workload. The NASA Task Load Index (NASA/TLX, Hart and Staveland) has been shown to be a highly reliable and sensitive measure of perceived mental workload. But a problem with measures like TLX is that there is still considerable disagreement as to what it is about mental workload that these subjective measures are actually measuring. The empirical use of subjective workload measures has largely been to provide estimates of the cognitive components of the actual mental workload required for a task. However, my research suggests that these measures may, in fact have greater potential in accurately assessing the affective components of workload. That is, for example, TLX may be more likely to assess the positive and negative feelings associated with varying workload levels, which in turn may potentially influence the decision making behavior that directly bears on performance and safety issues. Pilots, for example, are often called upon to complete many complex tasks that are high in mental workload, stress, and frustration, and that have significant dynamic decision making components -- often ones that involve risk as well.

  11. On Dynamical Behavior of a Friction-Induced Oscillator with 2-DOF on a Speed-Varying Traveling Belt

    Directory of Open Access Journals (Sweden)

    Jinjun Fan

    2017-01-01

    Full Text Available The dynamical behavior of a friction-induced oscillator with 2-DOF on a speed-varying belt is investigated by using the flow switchability theory of discontinuous dynamical systems. The mechanical model consists of two masses and a speed-varying traveling belt. Both of the masses on the traveling belt are connected with three linear springs and three dampers and are harmonically excited. Different domains and boundaries for such system are defined according to the friction discontinuity. Based on the above domains and boundaries, the analytical conditions of the passable motions, stick motions, and grazing motions for the friction-induced oscillator are obtained mathematically. An analytical prediction of periodic motions is performed through the mapping dynamics. With appropriate mapping structure, the simulations of the stick and nonstick motions in the two-degree friction-induced oscillator are illustrated for a better understanding of the motion complexity.

  12. Chaotic behavior appearing in dynamic motions of nanoscale particles

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, M [Innovation Plaza Tokai, Japan Science and Technology Agency, 23-1 Ahara-cho, Minami-ku, Nagoya 457-0063 (Japan); Harada, R [Department of Physics, Aichi University of Education, Hirosawa 1, Igaya-cho, Kariya 448-8542 (Japan); Kato, M [Innovation Plaza Tokai, Japan Science and Technology Agency, 23-1 Ahara-cho, Minami-ku, Nagoya 457-0063 (Japan); Sasaki, N [Department of Applied Physics, Faculty of Science and Engineering, Seikei University, 3-3-1 Kichijoji Kitamachi, Musashino-shi, Tokyo 180-8633 (Japan); Miura, K [Innovation Plaza Tokai, Japan Science and Technology Agency, 23-1 Ahara-cho, Minami-ku, Nagoya 457-0063 (Japan)

    2007-11-15

    The case of one-directional motion, under which graphite and mica flakes are driven on an octamethylcyclotetrasiloxane (OMCTS) liquid surface, is presented. The dynamical forces needed to move these bodies increase linearly with the logarithm of scanning velocity, which are typical energy dissipation process. A transition from quasi-periodic to chaotic motions occurs in the dynamics of a graphite flake when its velocity is increased. The dynamics of graphite flakes pulled by the nanotip on an OMCTS liquid surface can be treated as that of a nanobody on a liquid. On the other hand, there do not appear chaotic motions in the dynamics of a mica flake because the contact area between a mica flake and an OMCTS liquid surface is larger than that between a graphite flake and an OMCTS liquid surface.

  13. Chaotic behavior appearing in dynamic motions of nanoscale particles

    International Nuclear Information System (INIS)

    Ishikawa, M; Harada, R; Kato, M; Sasaki, N; Miura, K

    2007-01-01

    The case of one-directional motion, under which graphite and mica flakes are driven on an octamethylcyclotetrasiloxane (OMCTS) liquid surface, is presented. The dynamical forces needed to move these bodies increase linearly with the logarithm of scanning velocity, which are typical energy dissipation process. A transition from quasi-periodic to chaotic motions occurs in the dynamics of a graphite flake when its velocity is increased. The dynamics of graphite flakes pulled by the nanotip on an OMCTS liquid surface can be treated as that of a nanobody on a liquid. On the other hand, there do not appear chaotic motions in the dynamics of a mica flake because the contact area between a mica flake and an OMCTS liquid surface is larger than that between a graphite flake and an OMCTS liquid surface

  14. Chaotic behavior appearing in dynamic motions of nanoscale particles

    Science.gov (United States)

    Ishikawa, M.; Harada, R.; Kato, M.; Sasaki, N.; Miura, K.

    2007-11-01

    The case of one-directional motion, under which graphite and mica flakes are driven on an octamethylcyclotetrasiloxane (OMCTS) liquid surface, is presented. The dynamical forces needed to move these bodies increase linearly with the logarithm of scanning velocity, which are typical energy dissipation process. A transition from quasi-periodic to chaotic motions occurs in the dynamics of a graphite flake when its velocity is increased. The dynamics of graphite flakes pulled by the nanotip on an OMCTS liquid surface can be treated as that of a nanobody on a liquid. On the other hand, there do not appear chaotic motions in the dynamics of a mica flake because the contact area between a mica flake and an OMCTS liquid surface is larger than that between a graphite flake and an OMCTS liquid surface.

  15. Public health impact of disease-behavior dynamics. Comment on "Coupled disease-behavior dynamics on complex networks: A review" by Z. Wang et al.

    Science.gov (United States)

    Wells, Chad R.; Galvani, Alison P.

    2015-12-01

    In a loop of dynamic feedback, behavior such as the decision to vaccinate, hand washing, or avoidance influences the progression of the epidemic, yet behavior is driven by the individual's and population's perceived risk of infection during an outbreak. In what we believe will become a seminal paper that stimulates future research as well as an informative teaching aid, Wang et. al. comprehensively review methodological advances that have been used to incorporate human behavior into epidemiological models on the effects of coupling disease transmission and behavior on complex social networks [1]. As illustrated by the recent outbreaks of measles and Middle Eastern Respiratory Syndrome (MERS), here we highlight the importance of coupling behavior and disease transmission that Wang et al. address.

  16. Understanding Land Use and Land Cover Dynamics from 1976 to 2014 in Yellow River Delta

    Directory of Open Access Journals (Sweden)

    Baolei Zhang

    2017-03-01

    Full Text Available Long-term intensive land use/cover changes (LUCCs of the Yellow River Delta (YRD have been happening since the 1960s. The land use patterns of the LUCCs are crucial for bio-diversity conservation and/or sustainable development. This study quantified patterns of the LUCCs, explored the systematic transitions, and identified wetland change trajectory for the period 1976–2014 in the YRD. Landsat imageries of 1976, 1984, 1995, 2006, and 2014 were used to derive nine land use classes. Post classification change detection analysis based on enhanced transition matrix was applied to identify land use dynamics and trajectory of wetland change. The five cartographic outputs for changes in land use underlined major decreases in natural wetland areas and increases in artificial wetland and non-wetland, especially aquafarms, salt pans and construction lands. The systematic transitions in the YRD were wetland degradation, wetland artificialization, and urbanization. Wetland change trajectory results demonstrated that the main wetland changes were wetland degradation and wetland artificialization. Coastline change is the subordinate reason for natural wetland degradation in comparison with human activities. The results of this study allowed for an improvement in the understanding of the LUCC processes and enabled researchers and planners to focus on the most important signals of systematic landscape transitions while also allowing for a better understanding of the proximate causes of changes.

  17. Behaviour as a Lever of Ecological Transition? Understanding and Acting on Individual Behaviour and Collective Dynamics

    International Nuclear Information System (INIS)

    Martin, Solange; Gaspard, Albane

    2017-01-01

    Beyond broad policy declarations, the implementation of ecological transition - which consists mainly in curbing consumption of energy and raw materials in our societies - requires substantial behavioural change at the collective, but also, quite obviously, the individual level. Yet, though there is general consensus around the principle of embarking on the path to transition, things get more complicated when it comes to changing our practices and habits. Can we act on individual behaviour and collective dynamics in respect of this particular aim of ecological transition, and, if so, how are we to go about it? Solange Martin and Albane Gaspard have examined this question for the French Environment and Energy Management Agency (ADEME) and offer us the fruit of their labours here. They show, for example, how the social and human sciences help to understand behaviour both at the individual level and in its collective dimensions, and they outline different possible lines of action to modify it. But, given the entanglement between various levels, it is essential, if we are to act effectively on behaviour, to combine approaches, tools and actors, and to analyse and understand social practices thoroughly before implementing political projects or measures

  18. Influence of gravity on the skin thermal behavior: experimental study using dynamic infrared thermography.

    Science.gov (United States)

    Ratovoson, Domoina; Jourdan, Franck; Huon, Vincent

    2013-02-01

    To better understand the thermomechanical behavior of the skin and its direct environment, we present an experimental study using dynamic infrared thermography. This experimental study aims to highlight quantitatively some effects of blood flow on the heat diffusion. The originality of this research was to change the blood flow by using effects of gravity and to quantify the temperature changes. The experimental step consists of putting a cylindrical steel bar cooled or warmed on the skin of a human forearm and to measure the change of the temperature using an infrared camera. Measures have been recorded for different positions of the forearm. We noted very clearly the influence of blood circulation in the veins on the diffusion of the temperature. The return to thermal balance is faster when the arm is in a horizontal position. Moreover, a comparative study of experimental cooling and warming showed a symmetrical thermal behavior for the skin under this type of thermal solicitations. This work provided to build a database that can be used for the validation of predictive thermal models of human skin. © 2012 John Wiley & Sons A/S.

  19. Analysis of the Nonlinear Static and Dynamic Behavior of Offshore Structures

    KAUST Repository

    Alfosail, Feras

    2015-07-01

    Understanding static and dynamic nonlinear behavior of pipes and risers is crucial for the design aspects in offshore engineering fields. In this work, we examine two nonlinear problems in offshore engineering field: vortex Induced vibration of straight horizontal pipes, and boundary layer static solution of inclined risers. In the first study, we analyze the effect of the internal velocity of straight horizontal pipe and obtain the vortex induced vibration forces via coupling the pipe equation of motion with the recently modified Van Der Pol oscillator governing the lift coefficient. Our numerical results are obtained for two different pipe configurations: hinged-hinged, and clamped- clamped. The results show that the internal velocity reduces the vibration and the oscillation amplitudes. Also, it is shown that the clamped-clamped pipe configuration offers a wider range of internal velocities before buckling instability occurs. The results also demonstrate the effect of the end condition on the amplitudes of vibration. In the second study, we develop a boundary layer perturbation static solution to govern and simulate the static behavior of inclined risers. In the boundary layer analysis, we take in consideration the effects of the axial stretch, applied tension, and internal velocity. Our numerical simulation results show good agreement with the exact solutions for special cases. In addition, our developed method overcomes the mathematical and numerical limitations of the previous methods used before.

  20. Communication: On the origin of the non-Arrhenius behavior in water reorientation dynamics

    OpenAIRE

    Stirnemann, Guillaume; Laage, Damien

    2012-01-01

    International audience; We combine molecular dynamics simulations and analytic modeling to determine the origin of the non-Arrhenius temperature dependence of liquid water's reorientation and hydrogen-bond dynamics between 235 K and 350 K. We present a quantitative model connecting hydrogen-bond exchange dynamics to local structural fluctuations, measured by the asphericity of Voronoi cells associated with each water molecule. For a fixed local structure the regular Arrhenius behavior is reco...

  1. Disease and Behavioral Dynamics for Brucellosis Control in Elk and Cattle in the Greater Yellowstone Area

    OpenAIRE

    Xie, Fang; Horan, Richard D.

    2009-01-01

    This paper investigates private responses and ecological impacts of policies proposed to confront the problem of brucellosis being spread from elk to cattle in Wyoming. The policies consist of combinations of changes in elk feeding and population levels. Farmers' responses to these dynamics are modeled along with the associated impacts to livestock population dynamics. Our findings suggest that feedbacks between jointly determined disease dynamics and decentralized economic behavior matter, a...

  2. Dynamical Behavior of Multi-Robot Systems Using Lattice Gas Automata

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, S.M.; Robinett, R.; Stantz, K.M.; Trahan, M.W.; Wagner, J.S.

    1999-03-11

    Recent attention has been given to the deployment of an adaptable sensor array realized by multi-robotic systems. Our group has been studying the collective behavior of autonomous, multi-agent systems and their applications in the area of remote-sensing and emerging threats. To accomplish such tasks, an interdisciplinary research effort at Sandia National Laboratories are conducting tests in the fields of sensor technology, robotics, and multi-robotic and multi-agents architectures. Our goal is to coordinate a constellation of point sensors that optimizes spatial coverage and multivariate signal analysis using unmanned robotic vehicles (e.g., RATLERs, Robotic All-ten-sin Lunar Exploration Rover-class vehicles). Overall design methodology is to evolve complex collective behaviors realized through simple interaction (kinetic) physics and artificial intelligence to enable real-time operational responses to emerging threats. This paper focuses on our recent work understanding the dynamics of many-body systems using the physics-based hydrodynamic model of lattice gas automata. Three design features are investigated. One, for single-speed robots, a hexagonal nearest-neighbor interaction topology is necessary to preserve standard hydrodynamic flow. Two, adaptability, defined by the swarm's deformation rate, can be controlled through the hydrodynamic viscosity term, which, in turn, is defined by the local robotic interaction rules. Three, due to the inherent non-linearity of the dynamical equations describing large ensembles, development of stability criteria ensuring convergence to equilibrium states is developed by scaling information flow rates relative to a swarm's hydrodynamic flow rate. An initial test case simulates a swarm of twenty-five robots that maneuvers past an obstacle while following a moving target. A genetic algorithm optimizes applied nearest-neighbor forces in each of five spatial regions distributed over the simulation domain. Armed with

  3. A Comprehensive Understanding of Machine and Material Behaviors During Inertia Friction Welding

    Science.gov (United States)

    Tung, Daniel J.

    Inertia Friction Welding (IFW), a critical process to many industries, currently relies on trial-and-error experimentation to optimize process parameters. Although this Edisonian approach is very effective, the high time and dollar costs incurred during process development are the driving force for better design approaches. Thermal-stress finite element modeling has been increasingly used to aid in process development in the literature; however, several fundamental questions on machine and material behaviors remain unanswered. The work presented here aims produce an analytical foundation to significantly reduce the costly physical experimentation currently required to design the inertia welding of production parts. Particularly, the work is centered around the following two major areas. First, machine behavior during IFW, which critically determines deformation and heating, had not been well understood to date. In order to properly characterize the IFW machine behavior, a novel method based on torque measurements was invented to measure machine efficiency, i.e. the ratio of the initial kinetic energy of the flywheel to that contributing to workpiece heating and deformation. The measured efficiency was validated by both simple energy balance calculations and more sophisticated finite element modeling. For the first time, the efficiency dependence on both process parameters (flywheel size, initial rotational velocity, axial load, and surface roughness) and materials (1018 steel, Low Solvus High Refractory LSHR and Waspaloy) was quantified using the torque based measurement method. The effect of process parameters on machine efficiency was analyzed to establish simple-to-use yet powerful equations for selection and optimization of IFW process parameters for making welds; however, design criteria such as geometry and material optimization were not addressed. Second, there had been a lack of understanding of the bond formation during IFW. In the present research, an

  4. Stress, cues, and eating behavior. Using drug addiction paradigms to understand motivation for food.

    Science.gov (United States)

    Stojek, Monika Kardacz; Fischer, Sarah; MacKillop, James

    2015-09-01

    Eating patterns that lead to overconsumption of high fat, high sugar (HFHS) foods share similar features with addictive behaviors. Application of addiction paradigms, such as stress inductions, cue reactivity and behavioral economic assessments, to the study of motivation for HFHS food consumption may be a promising means of understanding food consumption. To date, few studies have investigated the interaction of stress and environmental cues on craving, and no study leveraged the state relative reinforcing value of foods (RRVfood) under varying conditions of affective states, the foci of the current study. This study used a mixed factorial design (Mood Induction: Neutral, Stress; Cues: Neutral, Food) with repeated measures on time (Baseline, Post-Mood Induction, Post-Cue Exposure). Participants (N = 133) were community adults who endorsed liking of HFHS snacks but denied eating pathology. The primary DVs were subjective craving and RRVfood. Negative and positive affect (NA, PA), the amount of food consumed, and latency to first bite were also examined. Participants in the Stress condition reported no change in craving or RRVfood. Exposure to food cues significantly increased participants' craving and RRVfood, but an interaction of stress and cues was not present. Participants did not differ on how many calories they consumed based on exposure to stress or food cues, but participants in the food cues condition had a shorter latency to the first bite of food. This study highlights the importance of environmental cues in food motivation. It also demonstrates the utility of using RRVfood to further characterize food motivation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Considering the role of social dynamics and positional behavior in gestural communication research.

    Science.gov (United States)

    Smith, Lindsey W; Delgado, Roberto A

    2013-09-01

    While the hominin fossil record cannot inform us on either the presence or extent of social and cognitive abilities that may have paved the way for the emergence of language, studying non-vocal communication among our closest living relatives, the African apes, may provide valuable information about how language originated. Although much has been learned from gestural signaling in non-human primates, we have not yet established how and why gestural repertoires vary across species, what factors influence this variation, and how knowledge of these differences can contribute to an understanding of gestural signaling's contribution to language evolution. In this paper, we review arguments surrounding the theory that language evolved from gestural signaling and suggest some important factors to consider when conducting comparative studies of gestural communication among African apes. Specifically, we propose that social dynamics and positional behavior are critical components that shape the frequency and nature of gestural signaling across species and we argue that an understanding of these factors could shed light on how gestural communication may have been the basis of human language. We outline predictions for the influence of these factors on the frequencies and types of gestures used across the African apes and highlight the importance of including these factors in future gestural communication research with primates. © 2013 Wiley Periodicals, Inc.

  6. A Behavioral Handwriting Model for Static and Dynamic Signature Synthesis.

    Science.gov (United States)

    Ferrer, Miguel A; Diaz, Moises; Carmona-Duarte, Cristina; Morales, Aythami

    2017-06-01

    The synthetic generation of static handwritten signatures based on motor equivalence theory has been recently proposed for biometric applications. Motor equivalence divides the human handwriting action into an effector dependent cognitive level and an effector independent motor level. The first level has been suggested by others as an engram, generated through a spatial grid, and the second has been emulated with kinematic filters. Our paper proposes a development of this methodology in which we generate dynamic information and provide a unified comprehensive synthesizer for both static and dynamic signature synthesis. The dynamics are calculated by lognormal sampling of the 8-connected continuous signature trajectory, which includes, as a novelty, the pen-ups. The forgery generation imitates a signature by extracting the most perceptually relevant points of the given genuine signature and interpolating them. The capacity to synthesize both static and dynamic signatures using a unique model is evaluated according to its ability to adapt to the static and dynamic signature inter- and intra-personal variability. Our highly promising results suggest the possibility of using the synthesizer in different areas beyond the generation of unlimited databases for biometric training.

  7. Understanding implications of consumer behavior for wildlife farming and sustainable wildlife trade.

    Science.gov (United States)

    Nuno, A; Blumenthal, J M; Austin, T J; Bothwell, J; Ebanks-Petrie, G; Godley, B J; Broderick, A C

    2018-04-01

    Unsustainable wildlife trade affects biodiversity and the livelihoods of communities dependent upon those resources. Wildlife farming has been proposed to promote sustainable trade, but characterizing markets and understanding consumer behavior remain neglected but essential steps in the design and evaluation of such operations. We used sea turtle trade in the Cayman Islands, where turtles have been farm raised for human consumption for almost 50 years, as a case study to explore consumer preferences toward wild-sourced (illegal) and farmed (legal) products and potential conservation implications. Combining methods innovatively (including indirect questioning and choice experiments), we conducted a nationwide trade assessment through in-person interviews from September to December 2014. Households were randomly selected using disproportionate stratified sampling, and responses were weighted based on district population size. We approached 597 individuals, of which 37 (6.2%) refused to participate. Although 30% of households had consumed turtle in the previous 12 months, the purchase and consumption of wild products was rare (e.g., 64-742 resident households consumed wild turtle meat [i.e., 0.3-3.5% of households] but represented a large threat to wild turtles in the area due to their reduced populations). Differences among groups of consumers were marked, as identified through choice experiments, and price and source of product played important roles in their decisions. Despite the long-term practice of farming turtles, 13.5% of consumers showed a strong preference for wild products, which demonstrates the limitations of wildlife farming as a single tool for sustainable wildlife trade. By using a combination of indirect questioning, choice experiments, and sales data to investigate demand for wildlife products, we obtained insights about consumer behavior that can be used to develop conservation-demand-focused initiatives. Lack of data from long-term social

  8. Study on dynamic behavior analysis of towed line array sensor

    Directory of Open Access Journals (Sweden)

    Hyun Kyoung Shin

    2012-03-01

    Full Text Available A set of equations of motion is derived for vibratory motions of an underwater cable connected to a moving vehicle at one end and with drogues at the other end. From the static analysis, cable configurations are obtained for different vehicle speeds and towing pretensions are determined by fluid resistance of drogues. Also the dynamic analysis is required to predict its vibratory motion. Nonlinear fluid drag forces greatly influence the dynamic tension. In this study, a numerical analysis program was developed to find out the characteristic of cable behaviour. The motion is described in terms of space and time coordinates based on Chebyshev polynomial expansions. For the spatial integration the collocation method is employed and the Newmark method is applied for the time integration. Dynamic tensions, displacements, velocities, accelerations were predicted in the time domain while natural frequencies and transfer functions were obtained in the frequency domain.

  9. Neural Correlates of Dynamically Evolving Interpersonal Ties Predict Prosocial Behavior

    Science.gov (United States)

    Fahrenfort, Johannes J.; van Winden, Frans; Pelloux, Benjamin; Stallen, Mirre; Ridderinkhof, K. Richard

    2011-01-01

    There is a growing interest for the determinants of human choice behavior in social settings. Upon initial contact, investment choices in social settings can be inherently risky, as the degree to which the other person will reciprocate is unknown. Nevertheless, people have been shown to exhibit prosocial behavior even in one-shot laboratory settings where all interaction has been taken away. A logical step has been to link such behavior to trait empathy-related neurobiological networks. However, as a social interaction unfolds, the degree of uncertainty with respect to the expected payoff of choice behavior may change as a function of the interaction. Here we attempt to capture this factor. We show that the interpersonal tie one develops with another person during interaction – rather than trait empathy – motivates investment in a public good that is shared with an anonymous interaction partner. We examined how individual differences in trait empathy and interpersonal ties modulate neural responses to imposed monetary sharing. After, but not before interaction in a public good game, sharing prompted activation of neural systems associated with reward (striatum), empathy (anterior insular cortex and anterior cingulate cortex) as well as altruism, and social significance [posterior superior temporal sulcus (pSTS)]. Although these activations could be linked to both empathy and interpersonal ties, only tie-related pSTS activation predicted prosocial behavior during subsequent interaction, suggesting a neural substrate for keeping track of social relevance. PMID:22403524

  10. Remarks on antipredator behavior and food chain dynamics

    DEFF Research Database (Denmark)

    Rinaldi, S.; Gragnani, A.; de Monte, Silvia

    2004-01-01

    When consumers feeding on a resource spend time in avoiding high risks of predation, the predator functional response declines with predator density. While this is well established, less attention has been paid to the dependence of the consumer functional response on predator density. Here we show...... how the separation of behavioral and ecological timescales allows one to determine both responses starting from an explicit behavioral model. Within the general set-up considered in this paper, the two functional responses can tend toward Holling type II responses when consumers react only weakly...... to predation. Thus, the main characteristics of the standard Rosenzweig-MacArthur tritrophic food chain (logistic resource and Holling type 11 consumer and predator) remain valid also when consumers have weak antipredator behavior. Moreover, through numerical analysis, we show that in a particular...

  11. Control of Rotational Dynamics for Ground and Aerial Behavior.

    Science.gov (United States)

    Zordan, Victor; Brown, David; Macchietto, Adriano; Yin, KangKang

    2014-10-01

    This paper proposes a physics-based framework to control rolling, flipping and other behaviors with significant rotational components. The proposed technique is a general approach for guiding coordinated action that can be layered over existing control architectures through the purposeful regulation of specific whole-body features. Namely, we apply control for rotation through the specification and execution of specific desired `rotation indices' for whole-body orientation, angular velocity and angular momentum control and highlight the use of the angular excursion as a means for whole-body rotation control. We account for the stylistic components of behaviors through reference posture control. The novelty of the described work includes control over behaviors with considerable rotational components, both on the ground and in the air as well as a number of characteristics useful for general control, such as flight planning with inertia modeling, compliant posture tracking, and contact control planning.

  12. The hippocampus and exploration: dynamically evolving behavior and neural representations

    Science.gov (United States)

    Johnson, Adam; Varberg, Zachary; Benhardus, James; Maahs, Anthony; Schrater, Paul

    2012-01-01

    We develop a normative statistical approach to exploratory behavior called information foraging. Information foraging highlights the specific processes that contribute to active, rather than passive, exploration and learning. We hypothesize that the hippocampus plays a critical role in active exploration through directed information foraging by supporting a set of processes that allow an individual to determine where to sample. By examining these processes, we show how information directed information foraging provides a formal theoretical explanation for the common hippocampal substrates of constructive memory, vicarious trial and error behavior, schema-based facilitation of memory performance, and memory consolidation. PMID:22848196

  13. The hippocampus and exploration: dynamically evolving behavior and neural representations

    Directory of Open Access Journals (Sweden)

    Adam eJohnson

    2012-07-01

    Full Text Available We develop a normative statistical approach to exploratory behavior called information foraging. Information foraging highlights the specific processes that contribute to active, rather than passive, exploration and learning. We hypothesize that the hippocampus plays a critical role in active exploration through directed information foraging by supporting a set of processes that allow an individual to determine where to sample. By examining these processes, we show how information directed information foraging provides a formal theoretical explanation for the common hippocampal substrates of constructive memory, vicarious trial and error behavior, schema-based facilitation of memory performance, and memory consolidation.

  14. From behavior to neural dynamics: An integrated theory of attention

    Science.gov (United States)

    Buschman, Timothy J.; Kastner, Sabine

    2015-01-01

    The brain has a limited capacity and therefore needs mechanisms to selectively enhance the information most relevant to one’s current behavior. We refer to these mechanisms as ‘attention’. Attention acts by increasing the strength of selected neural representations and preferentially routing them through the brain’s large-scale network. This is a critical component of cognition and therefore has been a central topic in cognitive neuroscience. Here we review a diverse literature that has studied attention at the level of behavior, networks, circuits and neurons. We then integrate these disparate results into a unified theory of attention. PMID:26447577

  15. Inner-City African-American Women's Adolescence as Stressful Life Events: Understanding Substance Abusing Behavior.

    Science.gov (United States)

    Durr, Marlese; Small, La Fleur F; Dunlap, Eloise

    2010-06-01

    Lula Beatty (2003:59) asks, "What makes a black woman, voluntarily take a substance into her body which alters her perceptions and feelings of well-being?" This research examines African American women's substance abuse as a response to stressful life events grounded in adolescence, drawing in part on the cognitive-transactional approach and distal stressor model to discuss the effects of stressors on mental health and substance abusing behavior. Most respondents viewed their adolescent experiences and the associated stress as tribulations or lessons to be lived through, rather than a signal of needed change in their social, cultural, and ecological life circumstances. The effect of exposure to constant stressors early in the life course coupled with proximal stressors often resulted in negative active responses to stress (i.e. substance abuse) and continued stunted emotional growth. Thus, our findings indicate that the experience of African American women as adolescents contributes to understanding substance abuse amongst this population. These findings further help develop the cognitive-transactional model, while adding to the distal stressors and life process model as a way of considering gender, race, and structural forces.

  16. Understanding watershed hydrogeochemistry: 2. Synchronized hydrological and geochemical processes drive stream chemostatic behavior

    Science.gov (United States)

    Li, Li; Bao, Chen; Sullivan, Pamela L.; Brantley, Susan; Shi, Yuning; Duffy, Christopher

    2017-03-01

    Why do solute concentrations in streams remain largely constant while discharge varies by orders of magnitude? We used a new hydrological land surface and reactive transport code, RT-Flux-PIHM, to understand this long-standing puzzle. We focus on the nonreactive chloride (Cl) and reactive magnesium (Mg) in the Susquehanna Shale Hills Critical Zone Observatory (SSHCZO). Simulation results show that stream discharge comes from surface runoff (Qs), soil lateral flow (QL), and deeper groundwater (QG), with QL contributing >70%. In the summer, when high evapotranspiration dries up and disconnects most of the watershed from the stream, Cl is trapped along planar hillslopes. Successive rainfalls connect the watershed and mobilize trapped Cl, which counteracts dilution effects brought about by high water storage (Vw) and maintains chemostasis. Similarly, the synchronous response of clay dissolution rates (Mg source) to hydrological conditions, maintained largely by a relatively constant ratio between "wetted" mineral surface area Aw and Vw, controls Mg chemostatic behavior. Sensitivity analysis indicates that cation exchange plays a secondary role in determining chemostasis compared to clay dissolution, although it does store an order-of-magnitude more Mg on exchange sites than soil water. Model simulations indicate that dilution (concentration decrease with increasing discharge) occurs only when mass influxes from soil lateral flow are negligible (e.g., via having low clay surface area) so that stream discharge is dominated by relatively constant mass fluxes from deep groundwater that are unresponsive to surface hydrological conditions.

  17. Understanding of action-related and abstract verbs in comparison: a behavioral and TMS study.

    Science.gov (United States)

    Innocenti, Alessandro; De Stefani, Elisa; Sestito, Mariateresa; Gentilucci, Maurizio

    2014-02-01

    Does the comprehension of both action-related and abstract verbs rely on motor simulation? In a behavioral experiment, in which a semantic task was used, response times to hand-action-related verbs were briefer than those to abstract verbs and both decreased with repetition of presentation. In a transcranial magnetic stimulation (TMS) experiment, single-pulse stimulation was randomly delivered over hand motor area of the left primary motor cortex to measure cortical-spinal excitability at 300 or 500 ms after verb presentation. Two blocks of trials were run. In each block, the same verbs were randomly presented. In the first block, stimulation induced an increase in motor evoked potentials only when TMS was applied 300 ms after action-related verb presentation. In the second block, no modulation of motor cortex was found according to type of verb and stimulation-delay. These results confirm that motor simulation can be used to understand action rather than abstract verbs. Moreover, they suggest that with repetition, the semantic processing for action verbs does not require activation of primary motor cortex anymore.

  18. Trying not to get burned: understanding homeowners' wildfire risk-mitigation behaviors.

    Science.gov (United States)

    Brenkert-Smith, Hannah; Champ, Patricia A; Flores, Nicholas

    2012-12-01

    Three causes have been identified for the spiraling cost of wildfire suppression in the United States: climate change, fuel accumulation from past wildfire suppression, and development in fire-prone areas. Because little is likely to be performed to halt the effects of climate on wildfire risk, and because fuel-management budgets cannot keep pace with fuel accumulation let alone reverse it, changing the behaviors of existing and potential homeowners in fire-prone areas is the most promising approach to decreasing the cost of suppressing wildfires in the wildland-urban interface and increasing the odds of homes surviving wildfire events. Wildfire education efforts encourage homeowners to manage their property to decrease wildfire risk. Such programs may be more effective with a better understanding of the factors related to homeowners' decisions to undertake wildfire risk-reduction actions. In this study, we measured whether homeowners had implemented 12 wildfire risk-mitigation measures in 2 Colorado Front Range counties. We found that wildfire information received from local volunteer fire departments and county wildfire specialists, as well as talking with neighbors about wildfire, were positively associated with higher levels of mitigation. Firsthand experience in the form of preparing for or undertaking an evacuation was also associated with a higher level of mitigation. Finally, homeowners who perceived higher levels of wildfire risk on their property had undertaken higher levels of wildfire-risk mitigation on their property.

  19. Overview of rehabilitative efforts in understanding and managing sexually coercive behaviors.

    Science.gov (United States)

    Schwartz, Barbara K

    2003-06-01

    In reviewing approaches to rehabilitative efforts in understanding and managing sexually coercive behaviors within the past two decades, one is struck by the development of two totally divergent paths. In 1971, there were a few civil commitment programs operated by mental health departments-most notably were the Sexual Psychopath Program at Western State Hospital in Fort Steilacoom, Washington, and the Massachusetts Treatment Center for Sexually Dangerous Persons. There were a few programs in prisons started by therapists who were interested in this population but given little recognition and even fewer resources. Additionally there were a handful of community-based programs including the J.J. Peters Institute in Philadelphia and PASO (Positive Approaches to Sex Offenders) in Albuquerque, New Mexico. Today there are thousands of specialized sexual offender treatment programs treating sexual abusers of every age, gender, ethnicity, and with a wide range of comorbid conditions. They are treated in the community, prisons, mental hospitals, residential facilities, and private practices. There is an international organization, a specialized research journal, and a specialized branch of the Department of Justice, the Center for Sex Offender Management. This chapter will provide an overview of the developments in the field, primarily covering the last 25 years. It will look at the evolution of theoretical approaches, the development of specialized approaches for subpopulations, significant landmarks, and possible future trends.

  20. Dynamic behavior of the intensified alternative configurations for quaternary distillation

    DEFF Research Database (Denmark)

    Ramirez-Marquez, Cesar; Cabrera-Ruiz, Julián; Juan Gabriel Segovia-Hernandez, Juan Gabriel

    2016-01-01

    value decomposition technique in all frequency domain. In order to complete the control study, the distillation schemes were subjected to closed-loop dynamic simulations. The results show that there are cases in which the intensified sequences do not only provide energy savings, but also may offer...

  1. The dynamic behavior of the exohedral transition metal complexes ...

    Indian Academy of Sciences (India)

    NAIWRIT KARMODAK

    Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore, Karnataka 560 012,. India. E-mail: jemmis@ipc.iisc.ernet.in. MS received 16 February 2017; accepted 13 April 2017. Abstract. The dynamic nature of the exohedral η6- and the η7-complexes of B40 with Cr(CO)3 has been explored ...

  2. Constraints on credit, consumer behavior and the dynamics of wealth

    Directory of Open Access Journals (Sweden)

    Gomes Costa Orlando

    2009-01-01

    Full Text Available This paper develops a simple macroeconomic model where the pattern of wealth accumulation is determined by a credit multiplier and the way households react to short-term fluctuations. Given this setup, long term wealth dynamics are eventually characterized by the presence of endogenous cycles.

  3. Dynamic Behavior of a Friction Pendulum with Elastomeric Layer

    Directory of Open Access Journals (Sweden)

    Gilbert-Rainer Gillich

    2012-01-01

    Full Text Available Transient dynamic characteristics of a friction pendulum can be determined using experimental ways. Nowadays, numerical simulation techniques allow obtaining these characteristics using mathematical models. The express advantage is represented by almost unlimited possibilities to extract and quantified in the regime of "post processing" regarding the results. In terms of efficiency this means increased performance regarding the research and product development.

  4. Understanding movement control in infants through the analysis of limb intersegmental dynamics.

    Science.gov (United States)

    Schneider, K; Zernicke, R F; Ulrich, B D; Jensen, J L; Thelen, E

    1990-12-01

    One important component in the understanding of the control of limb movements is the way in which the central nervous system accounts for joint forces and torques that may be generated not only by muscle actions but by gravity and by passive reactions related to the movements of limb segments. In this study, we asked how the neuromotor system of young infants controls a range of active and passive forces to produce a stereotypic, nonintentional movement. We specifically analyzed limb intersegmental dynamics in spontaneous, cyclic leg movements (kicking) of varying intensity in supine 3-month-old human infants. Using inverse dynamics, we calculated the contributions of active (muscular) and passive (motion-dependent and gravitational) torque components at the hip, knee, and ankle joints from three-dimensional limb kinematics. To calculate joint torques, accurate estimates were needed of the limb's anthropometric parameters, which we determined using a model of the human body. Our analysis of limb intersegmental dynamics explicitly quantified the complex interplay of active and passive forces producing the simple, involuntary kicking movements commonly seen in 3-month-old infants. our results revealed that in nonvigorous kicks, hip joint reversal was the result of an extensor torque due to gravity, opposed by the combined flexor effect of the muscle torque and the total motion-dependent torque. The total motion-dependent torque increased as a hip flexor torque in more vigorous kicks; an extensor muscle torque was necessary to counteract the flexor influences of the total motion-dependent torque and, in the case of large ranges of motion, a flexor gravity torque as well. Thus, with changing passive torque influences due to motions of the linked segments, the muscle torques were adjusted to produce a net torque to reverse the kicking motion. As a consequence, despite considerable heterogeneity in the intensity, range of motion, coordination, and movement context of

  5. A qualitative study to understand positive and negative child feeding behaviors of immigrant Asian Indian mothers in the US.

    Science.gov (United States)

    Momin, Shabnam R; Chung, Kimberly R; Olson, Beth H

    2014-09-01

    To understand current practice of child feeding behaviors, and underlying factors influencing these practices in Asian Indian mothers, qualitative in-depth interviews were conducted with 27 immigrant Asian Indian mothers of children ages 5-10 years. Using the theory of planned behavior as a guiding framework, child feeding behaviors employed, beliefs about the outcomes of feeding behaviors, perceived ease or difficultly in practicing feeding behaviors, and social norms were explored during the interviews. Thematic analysis was conducted using coding and display matrices. Mothers were motivated by nutrition outcomes when practicing positive and negative controlling feeding behaviors. Outcomes related to preservation of Indian culture and values also influenced feeding behaviors. Pressuring to eat was often practiced despite the perception of ineffectiveness. Use of food rewards was found, and use of TV to control children's food intake despite the clear understanding of undesirable nutrition outcomes was a unique finding. Asian Indian mothers need effective child feeding strategies that are culturally appropriate. Integrating cultural beliefs in nutrition education could help support existing motivation and behavior modification.

  6. Understanding the physical dynamics and ecological interactions in tidal stream energy environments

    Science.gov (United States)

    Fraser, Shaun; Williamson, Benjamin J.; Nikora, Vladimir; Scott, Beth E.

    2017-04-01

    Tidal stream energy devices are intended to operate in energetic physical environments characterised by high flows and extreme turbulence. These environments are often of ecological importance to a range of marine species. Understanding the physical dynamics and ecological interactions at fine scales in such sites is essential for device/array design and to understand environmental impacts. However, investigating fine scale characteristics requires high resolution field measurements which are difficult to attain and interpret, with data often confounded by interference related to turbulence. Consequently, field observations in tidal stream energy environments are limited and require the development of specialised analysis methods and so significant knowledge gaps are still present. The seabed mounted FLOWBEC platform is addressing these knowledge gaps using upward facing instruments to collect information from around marine energy infrastructure. Multifrequency and multibeam echosounder data provide detailed information on the distribution and interactions of biological targets, such as fish and diving seabirds, while simultaneously recording the scales and intensity of turbulence. Novel processing methodologies and instrument integration techniques have been developed which combine different data types and successfully separates signal from noise to reveal new evidence about the behaviour of mobile species and the structure of turbulence at all speeds of the tide and throughout the water column. Multiple platform deployments in the presence and absence of marine energy infrastructure reveal the natural characteristics of high energy sites, and enable the interpretation of the physical and biological impacts of tidal stream devices. These methods and results are relevant to the design and consenting of marine renewable energy technologies, and provide novel information on the use of turbulence for foraging opportunities in high energy sites by mobile species.

  7. Interpersonal pattern dynamics and adaptive behavior in multiagent neurobiological systems: conceptual model and data.

    Science.gov (United States)

    Passos, Pedro; Araújo, Duarte; Davids, Keith; Gouveia, Luis; Serpa, Sidónio; Milho, João; Fonseca, Sofia

    2009-10-01

    Ecological dynamics characterizes adaptive behavior as an emergent, self-organizing property of interpersonal interactions in complex social systems. The authors conceptualize and investigate constraints on dynamics of decisions and actions in the multiagent system of team sports. They studied coadaptive interpersonal dynamics in rugby union to model potential control parameter and collective variable relations in attacker-defender dyads. A videogrammetry analysis revealed how some agents generated fluctuations by adapting displacement velocity to create phase transitions and destabilize dyadic subsystems near the try line. Agent interpersonal dynamics exhibited characteristics of chaotic attractors and informational constraints of rugby union boxed dyadic systems into a low dimensional attractor. Data suggests that decisions and actions of agents in sports teams may be characterized as emergent, self-organizing properties, governed by laws of dynamical systems at the ecological scale. Further research needs to generalize this conceptual model of adaptive behavior in performance to other multiagent populations.

  8. Nonlinear electromechanical modelling and dynamical behavior analysis of a satellite reaction wheel

    Science.gov (United States)

    Aghalari, Alireza; Shahravi, Morteza

    2017-12-01

    The present research addresses the satellite reaction wheel (RW) nonlinear electromechanical coupling dynamics including dynamic eccentricity of brushless dc (BLDC) motor and gyroscopic effects, as well as dry friction of shaft-bearing joints (relative small slip) and bearing friction. In contrast to other studies, the rotational velocity of the flywheel is considered to be controllable, so it is possible to study the reaction wheel dynamical behavior in acceleration stages. The RW is modeled as a three-phases BLDC motor as well as flywheel with unbalances on a rigid shaft and flexible bearings. Improved Lagrangian dynamics for electromechanical systems is used to obtain the mathematical model of the system. The developed model can properly describe electromechanical nonlinear coupled dynamical behavior of the satellite RW. Numerical simulations show the effectiveness of the presented approach.

  9. Using video technology to disseminate behavioral procedures: a review of Functional Analysis: a Guide for Understanding Challenging Behavior (DVD).

    Science.gov (United States)

    Carr, James E; Fox, Eric J

    2009-01-01

    Although applied behavior analysis has generated many highly effective behavior-change procedures, the procedures have not always been effectively disseminated. One solution to this problem is the use of video technology, which has been facilitated by the ready availability of video production equipment and software and multiple distribution methods (e.g., DVD, online streaming). We review a recent DVD that was produced to disseminate the successful experimental functional analysis procedure. The review is followed by general recommendations for disseminating behavior-analytic procedures via video technology.

  10. Experimental study on dynamic behavior of large scale foundation, 1

    International Nuclear Information System (INIS)

    Hanada, Kazufumi; Sawada, Yoshihiro; Esashi, Yasuyuki; Ueshima, Teruyuki; Nakamura, Hideharu

    1983-01-01

    The large-sized, high performance vibrating table in the Nuclear Power Engineering Test Center is installed on a large-scale concrete foundation of length 90.9 m, width 44.8 m and maximum thickness 21 m, weighing 150,000 tons. Through the experimental study on the behavior of the foundation, which is set on gravel ground, useful information should be obtained on the siting of a nuclear power plant on the Quaternary stratum ground. The objective of research is to grasp the vibration characteristics of the foundation during the vibration of the table to evaluate the interaction between the foundation and the ground, and to evaluate an analytical method for numerically simulating the vibration behavior. In the present study, the vibration behavior of the foundation was clarified by measurement, and in order to predict the vibration behavior, the semi-infinite theory of elasticity was applied. The accuracy of this analytical method was demonstrated by comparison with the measured results. (Mori, K.)

  11. Simple PWM modulator topology with excellent dynamic behavior

    DEFF Research Database (Denmark)

    Poulsen, Søren; Andersen, Michael Andreas E.

    2004-01-01

    This paper proposes a new PWM modulator topology. The modulator is used in switch mode audio power amplifiers, but the topology can be used in a wide range of applications. Due to excellent transient behavior, the modulator is very suited for VRMs or other types of DC-DC or DC-AC applications....

  12. Modeling Dynamic Tactical Behaviors in Combatxxi using Hierarchical Task Networks

    Science.gov (United States)

    2014-06-01

    equipment, actions, and event coordination. This is a process that not only takes a great deal of time, but also one that requires the pro- grammer to have...within the gaming industry. Professor Stavros Vassos states that behavior trees provide “separation between the work of the pro- grammer and the game

  13. Neural correlates of dynamically evolving interpersonal ties predict prosocial behavior

    NARCIS (Netherlands)

    J.J. Fahrenfort (Johannes J.); F.A.A.M. Winden, van (Frans); B. Pelloux (Benjamin); M. Stallen (Mirre); K.R. Ridderinkhof (Richard)

    2012-01-01

    textabstractThere is a growing interest for the determinants of human choice behavior in social settings. Upon initial contact, investment choices in social settings can be inherently risky, as the degree to which the other person will reciprocate is unknown. Nevertheless, people have been shown to

  14. Neural correlates of dynamically evolving interpersonal ties predict prosocial behavior

    NARCIS (Netherlands)

    Fahrenfort, J.J.; van Winden, F.A.A.M.; Pelloux, B.; Stallen, M.; Ridderinkhof, K.R.

    2012-01-01

    There is a growing interest for the determinants of human choice behavior in social settings. Upon initial contact, investment choices in social settings can be inherently risky, as the degree to which the other person will reciprocate is unknown. Nevertheless, people have been shown to exhibit

  15. Remarks on antipredator behavior and food chain dynamics

    DEFF Research Database (Denmark)

    Rinaldi, S.; Gragnani, A.; de Monte, Silvia

    2004-01-01

    to predation. Thus, the main characteristics of the standard Rosenzweig-MacArthur tritrophic food chain (logistic resource and Holling type 11 consumer and predator) remain valid also when consumers have weak antipredator behavior. Moreover, through numerical analysis, we show that in a particular...

  16. Measuring and modeling behavioral decision dynamics in collective evacuation.

    Directory of Open Access Journals (Sweden)

    Jean M Carlson

    Full Text Available Identifying and quantifying factors influencing human decision making remains an outstanding challenge, impacting the performance and predictability of social and technological systems. In many cases, system failures are traced to human factors including congestion, overload, miscommunication, and delays. Here we report results of a behavioral network science experiment, targeting decision making in a natural disaster. In a controlled laboratory setting, our results quantify several key factors influencing individual evacuation decision making in a controlled laboratory setting. The experiment includes tensions between broadcast and peer-to-peer information, and contrasts the effects of temporal urgency associated with the imminence of the disaster and the effects of limited shelter capacity for evacuees. Based on empirical measurements of the cumulative rate of evacuations as a function of the instantaneous disaster likelihood, we develop a quantitative model for decision making that captures remarkably well the main features of observed collective behavior across many different scenarios. Moreover, this model captures the sensitivity of individual- and population-level decision behaviors to external pressures, and systematic deviations from the model provide meaningful estimates of variability in the collective response. Identification of robust methods for quantifying human decisions in the face of risk has implications for policy in disasters and other threat scenarios, specifically the development and testing of robust strategies for training and control of evacuations that account for human behavior and network topologies.

  17. Aging induced loss of complexity and dedifferentiation: consequences for coordination dynamics within and between brain, muscular and behavioral levels.

    Science.gov (United States)

    Sleimen-Malkoun, Rita; Temprado, Jean-Jacques; Hong, S Lee

    2014-01-01

    Growing evidence demonstrates that aging not only leads to structural and functional alterations of individual components of the neuro-musculo-skeletal system (NMSS) but also results in a systemic re-organization of interactions within and between the different levels and functional domains. Understanding the principles that drive the dynamics of these re-organizations is an important challenge for aging research. The present Hypothesis and Theory paper is a contribution in this direction. We propose that age-related declines in brain and behavior that have been characterized in the literature as dedifferentiation and the loss of complexity (LOC) are: (i) synonymous; and (ii) integrated. We argue that a causal link between the aforementioned phenomena exists, evident in the dynamic changes occurring in the aging NMSS. Through models and methods provided by a dynamical systems approach to coordination processes in complex living systems, we: (i) formalize operational hypotheses about the general principles of changes in cross-level and cross-domain interactions during aging; and (ii) develop a theory of the aging NMSS based on the combination of the frameworks of coordination dynamics (CD), dedifferentiation, and LOC. Finally, we provide operational predictions in the study of aging at neural, muscular, and behavioral levels, which lead to testable hypotheses and an experimental agenda to explore the link between CD, LOC and dedifferentiation within and between these different levels.

  18. Ionospheric and satellite observations for studying the dynamic behavior of typhoons and the detection of severe storms and tsunamis

    Science.gov (United States)

    Hung, R. J.; Smith, R. E.

    1978-01-01

    Atmospheric acoustic-gravity waves associated with severe thunderstorms, tornadoes, typhoons (hurricanes) and tsunamis can be studied through the coupling between the ionosphere and the troposphere. Reverse ray tracing computations of acoustic-gravity waves observed by an ionospheric Doppler sounder array show that wave sources are in the nearby storm systems and that the waves are excited prior to the storms. Results show that ionospheric observations, together with satellite observations, can contribute to the understanding of the dynamical behavior of typhoons, severe storms and tsunamis.

  19. Evaluation of the influence of parental anxiety on children's behavior and understanding children's dental anxiety after sequential dental visits

    OpenAIRE

    Swapnali Dilip Shinde; Rahul J Hegde

    2017-01-01

    Background: Identifying anxiety levels of parents accompanying their children can help the clinician in designing the behavior management strategies for the child. In addition, continued dental experience can improve the child's response, indicating desensitization to dental stress. Aims: To evaluate the influence of parental anxiety on children's behavior and understanding children's dental anxiety after sequential dental visits. Materials and Methods: A total of 175 children of age 6–12 yea...

  20. Scaling behavior of quantum critical relaxation dynamics of a system in a heat bath

    Science.gov (United States)

    Yin, Shuai; Lo, Chung-Yu; Chen, Pochung

    2016-05-01

    We study the scaling behavior of the relaxation dynamics to thermal equilibrium when a quantum system is near the quantum critical point. In particular, we investigate systems whose relaxation dynamics is described by a Lindblad master equation. We find that the universal scaling behavior not only appears in the equilibrium stage at the long-time limit but also manifests in the nonequilibrium relaxation process. While the critical behavior is dictated by the low-lying energy levels of the Hamiltonian, the dissipative part in the Lindblad equation also plays important roles in two aspects: First, the dissipative part makes the high-energy levels decay fast, after which the universal behavior controlled by the low-lying modes emerges. Second, the dissipation rate gives rise to a time scale that affects the scaling behavior. We confirm our theory by solving the Lindblad equation for the one-dimensional transverse-field Ising model.

  1. Modeling Temporal Behavior in Large Networks: A Dynamic Mixed-Membership Model

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, R; Gallagher, B; Neville, J; Henderson, K

    2011-11-11

    Given a large time-evolving network, how can we model and characterize the temporal behaviors of individual nodes (and network states)? How can we model the behavioral transition patterns of nodes? We propose a temporal behavior model that captures the 'roles' of nodes in the graph and how they evolve over time. The proposed dynamic behavioral mixed-membership model (DBMM) is scalable, fully automatic (no user-defined parameters), non-parametric/data-driven (no specific functional form or parameterization), interpretable (identifies explainable patterns), and flexible (applicable to dynamic and streaming networks). Moreover, the interpretable behavioral roles are generalizable, computationally efficient, and natively supports attributes. We applied our model for (a) identifying patterns and trends of nodes and network states based on the temporal behavior, (b) predicting future structural changes, and (c) detecting unusual temporal behavior transitions. We use eight large real-world datasets from different time-evolving settings (dynamic and streaming). In particular, we model the evolving mixed-memberships and the corresponding behavioral transitions of Twitter, Facebook, IP-Traces, Email (University), Internet AS, Enron, Reality, and IMDB. The experiments demonstrate the scalability, flexibility, and effectiveness of our model for identifying interesting patterns, detecting unusual structural transitions, and predicting the future structural changes of the network and individual nodes.

  2. Dynamics of gas-surface interactions atomic-level understanding of scattering processes at surfaces

    CERN Document Server

    Díez Muniño, Ricardo

    2013-01-01

    This book gives a representative survey of the state of the art of research on gas-surface interactions. It provides an overview of the current understanding of gas surface dynamics and, in particular, of the reactive and non-reactive processes of atoms and small molecules at surfaces. Leading scientists in the field, both from the theoretical and the experimental sides, write in this book about their most recent advances. Surface science grew as an interdisciplinary research area over the last decades, mostly because of new experimental technologies (ultra-high vacuum, for instance), as well as because of a novel paradigm, the ‘surface science’ approach. The book describes the second transformation which is now taking place pushed by the availability of powerful quantum-mechanical theoretical methods implemented numerically. In the book, experiment and theory progress hand in hand with an unprecedented degree of accuracy and control. The book presents how modern surface science targets the atomic-level u...

  3. Understanding the Dynamics of the Coupled Ring Current Radiation Belt System Using 4D VERB Simulations

    Science.gov (United States)

    Shprits, Y.; Kellerman, A. C.; Drozdov, A.; Orlova, K.; Spasojevic, M.

    2014-12-01

    Predicting and understanding the non-linear response of different electron populations in the inner magnetosphere, including ring current and higher energy radiation belts, has been a grand challenge since the beginning of the space age. During this past decade, there have been a number of long-term simulations that used lower energy boundary condition observations around geosynchronous orbit. In this study, we set up observations at around 15 RE and study how the combined convective-diffusive transport can result in the acceleration of keV to relativistic and ultra-relativistic energies. We show that while lower energy radial transport is dominated by the convection, higher energy transport is dominated by the diffusive radial transport. MLT dependent diffusion confidents allow us to study how difference in wave properties at different MLT can influence the dynamics of the particles. Inclusion of adiabatic changes also allows us to study the radial transport that results from pitch-angle scattering and adiabatic changes. We also show that there exists an intermediate range of energies for electrons for which both processes work simultaneously. We show the comparison of the 4D VERB simulations with the Van Allen Probes measurements.

  4. Grand challenges in developing a predictive understanding of global fire dynamics

    Science.gov (United States)

    Randerson, J. T.; Chen, Y.; Wiggins, E. B.; Andela, N.; Morton, D. C.; Veraverbeke, S.; van der Werf, G.

    2017-12-01

    High quality satellite observations of burned area and fire thermal anomalies over the past two decades have transformed our understanding of climate, ecosystem, and human controls on the spatial and temporal distribution of landscape fires. The satellite observations provide evidence for a rapid and widespread loss of fire from grassland and savanna ecosystems worldwide. Continued expansion of industrial agriculture suggests that observed declines in global burned area are likely to continue in future decades, with profound consequences for ecosystem function and the habitat of many endangered species. Satellite time series also highlight the importance of El Niño-Southern Oscillation and other climate modes as drivers of interannual variability. In many regions, lead times between climate indices and fire activity are considerable, enabling the development of early warning prediction systems for fire season severity. With the recent availability of high-resolution observations from Suomi NPP, Landsat 8, and Sentinel 2, the field of global fire ecology is poised to make even more significant breakthroughs over the next decade. With these new observations, it may be possible to reduce uncertainties in the spatial pattern of burned area by several fold. It is difficult to overstate the importance of these new data constraints for improving our understanding of fire impacts on human health and radiative forcing of climate change. A key research challenge in this context is to understand how the loss of global burned area will affect magnitude of the terrestrial carbon sink and trends in atmospheric composition. Advances in prognostic fire modeling will require new approaches linking agriculture with landscape fire dynamics. A critical need in this context is the development of predictive models of road networks and other drivers of land fragmentation, and a closer integration of fragmentation information with algorithms predicting fire spread. Concurrently, a better

  5. Dynamical behavior of granular matter in low gravity (diamagnetic levitation)

    International Nuclear Information System (INIS)

    Brooks, J.S.; Cothern, J.A.

    2001-01-01

    We report studies on the dynamics of macroscopic particles in a low-gravity 'magnetic levitation' environment. In a real sense, this allows the investigation of new states of granular matter. Particle ensembles (rods, spheres, or grains) can be held in a weak confining potential due to diamagnetic forces in a high-field-resistive magnet. In such a case 'kT' is not zero, and assemblies of particles undergo ergodic processes to find the lowest configurational ground state. This new area presents unique problems for video data acquisition and mathematical descriptions of the complex dynamic motions, interactions, and configurations of single and multiple particle assemblies. Three examples of such processes are presented

  6. Diffusive long-time behavior of Kawasaki dynamics

    CERN Document Server

    Cancrin, C; Roberto, C

    2003-01-01

    If $P_t$ is the semigroup associated with the Kawasaki dynamics on $\\Z^d$ and $f$ is a local function on the configuration space, then the variance with respect to the invariant measure $\\mu$ of $P_t f$ goes to zero as $t\\to\\oo$ faster than $t^{-d/2+\\e}$, with $\\e$ arbitrarily small. The fundamental assumption is a mixing condition on the interaction of Dobrushin and Schlosman type.

  7. Dynamical behavior of price forecasting in structures of group correlations

    Science.gov (United States)

    Lim, Kyuseong; Kim, Soo Yong; Kim, Kyungsik

    2015-07-01

    We investigate the prediction of the future prices from the structures and the networks of the companies in special financial groups. After the financial group network has been constructed from the value of the high cross-correlation, each company in a group is simulated and analyzed how it buys or sells stock is anaylzed and how it makes rational investments is forecasted. In the shortmemory behavior rather than the long-memory behavior, each company among a group can make a rational investment decision by using a stochastic evolution rule in the financial network. In particular, we simulate and analyze the investment situation in connection with the empirical data and the simulated result.

  8. Entropy Maximization as a Basis for Information Recovery in Dynamic Economic Behavioral Systems

    Directory of Open Access Journals (Sweden)

    George Judge

    2015-02-01

    Full Text Available As a basis for information recovery in open dynamic microeconomic systems, we emphasize the connection between adaptive intelligent behavior, causal entropy maximization and self-organized equilibrium seeking behavior. This entropy-based causal adaptive behavior framework permits the use of information-theoretic methods as a solution basis for the resulting pure and stochastic inverse economic-econometric problems. We cast the information recovery problem in the form of a binary network and suggest information-theoretic methods to recover estimates of the unknown binary behavioral parameters without explicitly sampling the configuration-arrangement of the sample space.

  9. Dynamical Behavior of a stochastic SIRS epidemic model

    OpenAIRE

    Hieu, N. T.; Du, N. H.; Auger, P.; Dang, N. H.

    2015-01-01

    In this paper we study the Kernack - MacKendrick model under telegraph noise. The telegraph noise switches at random between two SIRS models. We give out conditions for the persistence of the disease and the stability of a disease free equilibrium. We show that the asymptotic behavior highly depends on the value of a threshold $\\lambda$ which is calculated from the intensities of switching between environmental states, the total size of the population as well as the parameters of both SIRS sy...

  10. Understanding caregivers' intentions for their child to walk to school: Further application of the theory of planned behavior.

    Science.gov (United States)

    Schuster, Lisa; Kubacki, Krzysztof; Rundle-Thiele, Sharyn

    2016-01-01

    Increases in childhood obesity have coincided with declines in active transportation to school. This research builds on largely atheoretical extant literature examining factors that influence walk-to-school behavior through application of the theory of planned behavior (TPB). Understanding caregivers' decision for their child to walk to/from school is key to developing interventions to promote this cost-effective and accessible health behavior. The results from an online survey of 512 caregivers provide support for the TPB, highlighting the important role of subjective norms. This suggests marketers should nurture caregivers' perception that important others approve of walking to school.

  11. Huddling behavior in emperor penguins: Dynamics of huddling.

    Science.gov (United States)

    Gilbert, Caroline; Robertson, Graham; Le Maho, Yvon; Naito, Yasuhiko; Ancel, André

    2006-07-30

    Although huddling was shown to be the key by which emperor penguins (Aptenodytes forsteri) save energy and sustain their breeding fast during the Antarctic winter, the intricacies of this social behavior have been poorly studied. We recorded abiotic variables with data loggers glued to the feathers of eight individually marked emperor penguins to investigate their thermoregulatory behavior and to estimate their "huddling time budget" throughout the breeding season (pairing and incubation period). Contrary to the classic view, huddling episodes were discontinuous and of short and variable duration, lasting 1.6+/-1.7 (S.D.) h on average. Despite heterogeneous huddling groups, birds had equal access to the warmth of the huddles. Throughout the breeding season, males huddled for 38+/-18% (S.D.) of their time, which raised the ambient temperature that birds were exposed to above 0 degrees C (at average external temperatures of -17 degrees C). As a consequence of tight huddles, ambient temperatures were above 20 degrees C during 13+/-12% (S.D.) of their huddling time. Ambient temperatures increased up to 37.5 degrees C, close to birds' body temperature. This complex social behavior therefore enables all breeders to get a regular and equal access to an environment which allows them to save energy and successfully incubate their eggs during the Antarctic winter.

  12. Study of cement pastes rheological behavior using dynamic shear rheometer

    Directory of Open Access Journals (Sweden)

    J. E. S. L. Teixeira

    Full Text Available Concrete, in its fresh state, has flow characteristics that are crucial to its proper launch and densification. These characteristics are usually measured through empirical testing as the slump test, but this test does not quantify completely the material behavior. Since this material is characterized as a Bingham fluid, it is essential the study of its rheological behavior to verify its properties even in fresh state. The use of classical rheology has been employed by the scientific community to obtain rheological parameters determinants to characterize this material, such as yield stress, plastic viscosity and evolution of shear stress to shear rate. Thus, this present study aims to determine the rheological behavior of different cement pastes produced with cement CP III 40 RS, varying between them the hydration periods (20 and 60 min, the water-cement ratio (0.40, 0.45 and 0.50 and the use or not of additive. Samples were assayed by flow test to determine the rheological parameters showing the effect of the variables mentioned above in these parameters.

  13. Land use and land cover dynamics in the Brazilian Amazon: understanding human-environmental interactions

    NARCIS (Netherlands)

    Souza Soler, de L.

    2014-01-01

    Land use and land cover dynamics are a result of the interactions between human activities and the environment. The objective of this thesis is to analyze Amazonian land use and land cover pattern dynamics in order to identify the underlying system dynamics. By combining empirical statistical

  14. Using Dynamic Tools to Develop an Understanding of the Fundamental Ideas of Calculus

    Science.gov (United States)

    Verzosa, Debbie; Guzon, Angela Fatima; De Las Peñas, Ma. Louise Antonette N.

    2014-01-01

    Although dynamic geometry software has been extensively used for teaching calculus concepts, few studies have documented how these dynamic tools may be used for teaching the rigorous foundations of the calculus. In this paper, we describe lesson sequences utilizing dynamic tools for teaching the epsilon-delta definition of the limit and the…

  15. Modification of ferromagnetic nanostripe dynamic behavior by edge defects

    Science.gov (United States)

    Hu, Bo; Zhao, Chunwang; Li, Yulian

    2018-03-01

    The dynamic spectra of ferromagnetic nanostripes with different edge defects are investigated using the three-dimensional object-oriented micromagnetic framework code. Two main resonance peaks are found in nanostripes due to nonuniformity of the static magnetization patterns. The higher peak can be identified by the precession of magnetization in the middle part of the nanostripes. The lower one can be identified by the sample end part. The values of two precession frequencies and linewidths can be modified using the edge defect to tune the magnetization of different parts of samples, which is important and useful in magnetic storage devices.

  16. A system dynamics model of clinical decision thresholds for the detection of developmental-behavioral disorders

    Directory of Open Access Journals (Sweden)

    R. Christopher Sheldrick

    2016-11-01

    Full Text Available Abstract Background Clinical decision-making has been conceptualized as a sequence of two separate processes: assessment of patients’ functioning and application of a decision threshold to determine whether the evidence is sufficient to justify a given decision. A range of factors, including use of evidence-based screening instruments, has the potential to influence either or both processes. However, implementation studies seldom specify or assess the mechanism by which screening is hypothesized to influence clinical decision-making, thus limiting their ability to address unexpected findings regarding clinicians’ behavior. Building on prior theory and empirical evidence, we created a system dynamics (SD model of how physicians’ clinical decisions are influenced by their assessments of patients and by factors that may influence decision thresholds, such as knowledge of past patient outcomes. Using developmental-behavioral disorders as a case example, we then explore how referral decisions may be influenced by changes in context. Specifically, we compare predictions from the SD model to published implementation trials of evidence-based screening to understand physicians’ management of positive screening results and changes in referral rates. We also conduct virtual experiments regarding the influence of a variety of interventions that may influence physicians’ thresholds, including improved access to co-located mental health care and improved feedback systems regarding patient outcomes. Results Results of the SD model were consistent with recent implementation trials. For example, the SD model suggests that if screening improves physicians’ accuracy of assessment without also influencing decision thresholds, then a significant proportion of children with positive screens will not be referred and the effect of screening implementation on referral rates will be modest—results that are consistent with a large proportion of published

  17. Dynamic Socialized Gaussian Process Models for Human Behavior Prediction in a Health Social Network

    Science.gov (United States)

    Shen, Yelong; Phan, NhatHai; Xiao, Xiao; Jin, Ruoming; Sun, Junfeng; Piniewski, Brigitte; Kil, David; Dou, Dejing

    2016-01-01

    Modeling and predicting human behaviors, such as the level and intensity of physical activity, is a key to preventing the cascade of obesity and helping spread healthy behaviors in a social network. In our conference paper, we have developed a social influence model, named Socialized Gaussian Process (SGP), for socialized human behavior modeling. Instead of explicitly modeling social influence as individuals' behaviors influenced by their friends' previous behaviors, SGP models the dynamic social correlation as the result of social influence. The SGP model naturally incorporates personal behavior factor and social correlation factor (i.e., the homophily principle: Friends tend to perform similar behaviors) into a unified model. And it models the social influence factor (i.e., an individual's behavior can be affected by his/her friends) implicitly in dynamic social correlation schemes. The detailed experimental evaluation has shown the SGP model achieves better prediction accuracy compared with most of baseline methods. However, a Socialized Random Forest model may perform better at the beginning compared with the SGP model. One of the main reasons is the dynamic social correlation function is purely based on the users' sequential behaviors without considering other physical activity-related features. To address this issue, we further propose a novel “multi-feature SGP model” (mfSGP) which improves the SGP model by using multiple physical activity-related features in the dynamic social correlation learning. Extensive experimental results illustrate that the mfSGP model clearly outperforms all other models in terms of prediction accuracy and running time. PMID:27746515

  18. Dynamic Socialized Gaussian Process Models for Human Behavior Prediction in a Health Social Network.

    Science.gov (United States)

    Shen, Yelong; Phan, NhatHai; Xiao, Xiao; Jin, Ruoming; Sun, Junfeng; Piniewski, Brigitte; Kil, David; Dou, Dejing

    2016-11-01

    Modeling and predicting human behaviors, such as the level and intensity of physical activity, is a key to preventing the cascade of obesity and helping spread healthy behaviors in a social network. In our conference paper, we have developed a social influence model, named Socialized Gaussian Process (SGP), for socialized human behavior modeling. Instead of explicitly modeling social influence as individuals' behaviors influenced by their friends' previous behaviors, SGP models the dynamic social correlation as the result of social influence. The SGP model naturally incorporates personal behavior factor and social correlation factor (i.e., the homophily principle: Friends tend to perform similar behaviors) into a unified model. And it models the social influence factor (i.e., an individual's behavior can be affected by his/her friends) implicitly in dynamic social correlation schemes. The detailed experimental evaluation has shown the SGP model achieves better prediction accuracy compared with most of baseline methods. However, a Socialized Random Forest model may perform better at the beginning compared with the SGP model. One of the main reasons is the dynamic social correlation function is purely based on the users' sequential behaviors without considering other physical activity-related features. To address this issue, we further propose a novel " multi-feature SGP model " (mfSGP) which improves the SGP model by using multiple physical activity-related features in the dynamic social correlation learning. Extensive experimental results illustrate that the mfSGP model clearly outperforms all other models in terms of prediction accuracy and running time.

  19. External Monitoring and Dynamic Behavior in Mutual Funds

    Directory of Open Access Journals (Sweden)

    Jian Wang

    2016-01-01

    Full Text Available This paper studies the impact of external monitoring on the behavior in mutual funds. Specifically, we investigate how and why external monitoring can alleviate contracting inefficiency caused by information asymmetry between investors and the manager. It is shown that efficiency loss emerges when investors contract with the manager just relying on her investment return history. The establishment of external monitoring that provides investors more information about the manager’s ability can improve contracting efficiency, which converges to first-best as external monitoring strengthens. These results provide strong support for tightening supervision in mutual fund industry.

  20. Problems of dynamics radionuclides behavior in environment of Belarus

    International Nuclear Information System (INIS)

    Basharin, A.V.; Matveev, S.A.; Pushkareva, T.L.; Sharovarov, G.A.

    2003-01-01

    The experience of various methods application for radionuclide contaminated objects after the Chernobyl accident is considered. Methods useful to different objects, including kindergartens, are defined as a result of analysis. Methods of observation and control 134,137 Cs, 90 Sr and 238-240 Pu behavior in various environments are described. Value of the second air pollution after extraordinary situation at contaminated territories and object 'Ukryttia' is given. Dates of post-Chernobyl contamination of rivers and soils with radiocesium and radiostrontium, as well as deactivation of social objects are generalized

  1. The Dynamical Behaviors in a Stochastic SIS Epidemic Model with Nonlinear Incidence.

    Science.gov (United States)

    Rifhat, Ramziya; Ge, Qing; Teng, Zhidong

    2016-01-01

    A stochastic SIS-type epidemic model with general nonlinear incidence and disease-induced mortality is investigated. It is proved that the dynamical behaviors of the model are determined by a certain threshold value [Formula: see text]. That is, when [Formula: see text] and together with an additional condition, the disease is extinct with probability one, and when [Formula: see text], the disease is permanent in the mean in probability, and when there is not disease-related death, the disease oscillates stochastically about a positive number. Furthermore, when [Formula: see text], the model admits positive recurrence and a unique stationary distribution. Particularly, the effects of the intensities of stochastic perturbation for the dynamical behaviors of the model are discussed in detail, and the dynamical behaviors for the stochastic SIS epidemic model with standard incidence are established. Finally, the numerical simulations are presented to illustrate the proposed open problems.

  2. Dynamic superhydrophobic behavior in scalable random textured polymeric surfaces

    Science.gov (United States)

    Moreira, David; Park, Sung-hoon; Lee, Sangeui; Verma, Neil; Bandaru, Prabhakar R.

    2016-03-01

    Superhydrophobic (SH) surfaces, created from hydrophobic materials with micro- or nano- roughness, trap air pockets in the interstices of the roughness, leading, in fluid flow conditions, to shear-free regions with finite interfacial fluid velocity and reduced resistance to flow. Significant attention has been given to SH conditions on ordered, periodic surfaces. However, in practical terms, random surfaces are more applicable due to their relative ease of fabrication. We investigate SH behavior on a novel durable polymeric rough surface created through a scalable roll-coating process with varying micro-scale roughness through velocity and pressure drop measurements. We introduce a new method to construct the velocity profile over SH surfaces with significant roughness in microchannels. Slip length was measured as a function of differing roughness and interstitial air conditions, with roughness and air fraction parameters obtained through direct visualization. The slip length was matched to scaling laws with good agreement. Roughness at high air fractions led to a reduced pressure drop and higher velocities, demonstrating the effectiveness of the considered surface in terms of reduced resistance to flow. We conclude that the observed air fraction under flow conditions is the primary factor determining the response in fluid flow. Such behavior correlated well with the hydrophobic or superhydrophobic response, indicating significant potential for practical use in enhancing fluid flow efficiency.

  3. Use of a dynamic simulation model to understand nitrogen cycling in the middle Rio Grande, NM.

    Energy Technology Data Exchange (ETDEWEB)

    Meixner, Tom (University of Arizona, Tucson, AZ); Tidwell, Vincent Carroll; Oelsner, Gretchen (University of Arizona, Tucson, AZ); Brooks, Paul (University of Arizona, Tucson, AZ); Roach, Jesse D.

    2008-08-01

    Water quality often limits the potential uses of scarce water resources in semiarid and arid regions. To best manage water quality one must understand the sources and sinks of both solutes and water to the river system. Nutrient concentration patterns can identify source and sink locations, but cannot always determine biotic processes that affect nutrient concentrations. Modeling tools can provide insight into these large-scale processes. To address questions about large-scale nitrogen removal in the Middle Rio Grande, NM, we created a system dynamics nitrate model using an existing integrated surface water--groundwater model of the region to evaluate our conceptual models of uptake and denitrification as potential nitrate removal mechanisms. We modeled denitrification in groundwater as a first-order process dependent only on concentration and used a 5% denitrification rate. Uptake was assumed to be proportional to transpiration and was modeled as a percentage of the evapotranspiration calculated within the model multiplied by the nitrate concentration in the water being transpired. We modeled riparian uptake as 90% and agricultural uptake as 50% of the respective evapotranspiration rates. Using these removal rates, our model results suggest that riparian uptake, agricultural uptake and denitrification in groundwater are all needed to produce the observed nitrate concentrations in the groundwater, conveyance channels, and river as well as the seasonal concentration patterns. The model results indicate that a total of 497 metric tons of nitrate-N are removed from the Middle Rio Grande annually. Where river nitrate concentrations are low and there are no large nitrate sources, nitrate behaves nearly conservatively and riparian and agricultural uptake are the most important removal mechanisms. Downstream of a large wastewater nitrate source, denitrification and agricultural uptake were responsible for approximately 90% of the nitrogen removal.

  4. Understanding the adoption dynamics of medical innovations: affordances of the da Vinci robot in the Netherlands.

    Science.gov (United States)

    Abrishami, Payam; Boer, Albert; Horstman, Klasien

    2014-09-01

    This study explored the rather rapid adoption of a new surgical device - the da Vinci robot - in the Netherlands despite the high costs and its controversial clinical benefits. We used the concept 'affordances' as a conceptual-analytic tool to refer to the perceived promises, symbolic meanings, and utility values of an innovation constructed in the wider social context of use. This concept helps us empirically understand robot adoption. Data from 28 in-depth interviews with diverse purposively-sampled stakeholders, and from medical literature, policy documents, Health Technology Assessment reports, congress websites and patients' weblogs/forums between April 2009 and February 2014 were systematically analysed from the perspective of affordances. We distinguished five interrelated affordances of the robot that accounted for shaping and fulfilling its rapid adoption: 'characteristics-related' affordances such as smart nomenclature and novelty, symbolising high-tech clinical excellence; 'research-related' affordances offering medical-technical scientific excellence; 'entrepreneurship-related' affordances for performing better-than-the-competition; 'policy-related' affordances indicating the robot's liberalised provision and its reduced financial risks; and 'communication-related' affordances of the robot in shaping patients' choices and the public's expectations by resonating promising discourses while pushing uncertainties into the background. These affordances make the take-up and use of the da Vinci robot sound perfectly rational and inevitable. This Dutch case study demonstrates the fruitfulness of the affordances approach to empirically capturing the contextual dynamics of technology adoption in health care: exploring in-depth actors' interaction with the technology while considering the interpretative spaces created in situations of use. This approach can best elicit real-life value of innovations, values as defined through the eyes of (potential) users

  5. Advances in the understanding of nutrient dynamics and management in UK agriculture

    International Nuclear Information System (INIS)

    Dungait, Jennifer A.J.; Cardenas, Laura M.; Blackwell, Martin S.A.; Wu, Lianhai; Withers, Paul J.A.; Chadwick, David R.; Bol, Roland; Murray, Philip J.; Macdonald, Andrew J.; Whitmore, Andrew P.; Goulding, Keith W.T.

    2012-01-01

    Current research on macronutrient cycling in UK agricultural systems aims to optimise soil and nutrient management for improved agricultural production and minimise effects on the environment and provision of ecosystem services. Nutrient use inefficiencies can cause environmental pollution through the release of greenhouse gases into the atmosphere and of soluble and particulate forms of N, P and carbon (C) in leachate and run-off into watercourses. Improving nutrient use efficiencies in agriculture calls for the development of sustainable nutrient management strategies: more efficient use of mineral fertilisers, increased recovery and recycling of waste nutrients, and, better exploitation of the substantial inorganic and organic reserves of nutrients in the soil. Long-term field experimentation in the UK has provided key knowledge of the main nutrient transformations in agricultural soils. Emerging analytical technologies, especially stable isotope labelling, that better characterise macronutrient forms and bioavailability and improve the quantification of the complex relationships between the macronutrients in soils at the molecular scale, are augmenting this knowledge by revealing the underlying processes. The challenge for the future is to determine the relationships between the dynamics of N, P and C across scales, which will require both new modelling approaches and integrated approaches to macronutrient cycling. -- Highlights: ► Major advances in the knowledge of macronutrient cycling in agricultural soils are reviewed in the context of management. ► Novel analytical techniques and innovative modelling approaches that enhance understanding of nutrient cycling are explored. ► Knowledge gaps are identified, and the potential to improve comprehension of the integrated nutrient cycles is considered.

  6. An association rule mining-based framework for understanding lifestyle risk behaviors.

    Directory of Open Access Journals (Sweden)

    So Hyun Park

    Full Text Available OBJECTIVES: This study investigated the prevalence and patterns of lifestyle risk behaviors in Korean adults. METHODS: We utilized data from the Fourth Korea National Health and Nutrition Examination Survey for 14,833 adults (>20 years of age. We used association rule mining to analyze patterns of lifestyle risk behaviors by characterizing non-adherence to public health recommendations related to the Alameda 7 health behaviors. The study variables were current smoking, heavy drinking, physical inactivity, obesity, inadequate sleep, breakfast skipping, and frequent snacking. RESULTS: Approximately 72% of Korean adults exhibited two or more lifestyle risk behaviors. Among women, current smoking, obesity, and breakfast skipping were associated with inadequate sleep. Among men, breakfast skipping with additional risk behaviors such as physical inactivity, obesity, and inadequate sleep was associated with current smoking. Current smoking with additional risk behaviors such as inadequate sleep or breakfast skipping was associated with physical inactivity. CONCLUSION: Lifestyle risk behaviors are intercorrelated in Korea. Information on patterns of lifestyle risk behaviors could assist in planning interventions targeted at multiple behaviors simultaneously.

  7. Integrating Norm Activation Model and Theory of Planned Behavior to Understand Sustainable Transport Behavior: Evidence from China

    Directory of Open Access Journals (Sweden)

    Yuwei Liu

    2017-12-01

    Full Text Available With increasing urbanization in China, many cities are facing serious environmental problems due to continuous and substantial increase in automobile transportation. It is becoming imperative to examine effective ways to reduce individual automobile use to facilitate sustainable transportation behavior. Empirical, theory-based research on sustainable transportation in China is limited. In this research, we propose an integrated model based on the norm activation model and the theory of planned behavior by combining normative and rational factors to predict individuals’ intention to reduce car use. Data from a survey of 600 car drivers in China’s three metropolitan areas was used to test the proposed model and hypotheses. Results showed that three variables, perceived norm of car-transport reduction, attitude towards reduction, and perceived behavior control over car-transport reduction, significantly affected the intention to reduce car-transport. Personal norms mediated the relationship between awareness of consequences of car-transport, ascription of responsibility of car-transport, perceived subjective norm for car-transport reduction, and intention to reduce car-transport. The results of this research not only contribute to theory development in the area of sustainable transportation behavior, but also provide a theoretical frame of reference for relevant policy-makers in urban transport management.

  8. Understanding Physical Activity Behavior in African American and Caucasian College Students: An Application of the Theory of Planned Behavior

    Science.gov (United States)

    Blanchard, Chris; Fisher, Janet; Sparling, Phil; Nehl, Erich; Rhodes, Ryan; Courneya, Kerry; Baker, Frank

    2008-01-01

    Only 30% of college students meet the recommended amount of physical activity (PA) for health benefits, and this number is lower for African American students. Moreover, the correlates of PA may vary by ethnicity. Objective: In the present study, the authors tested the utility of the theory of planned behavior for explaining PA intentions and…

  9. Understanding strength exercise intentions and behavior in hematologic cancer survivors: an analysis of the intention-behavior gap.

    Science.gov (United States)

    Vallerand, James R; Rhodes, Ryan E; Walker, Gordon J; Courneya, Kerry S

    2016-12-01

    Strength exercise improves many health outcomes in cancer survivors but the prevalence and correlates of strength exercise have not been well-described. Moreover, no study has examined the critical intention-behavior gap for exercise in cancer survivors. The aims of this study are to quantify the intention-behavior gap for strength exercise in hematologic cancer survivors (HCS) and examine correlates of both intention formation and translation using the multi-process action control framework (M-PAC). A random sample of 2100 HCS in Alberta, Canada, were mailed a survey assessing strength exercise behavior, the M-PAC, and demographic/medical variables. Separate logistic regressions were used to analyze the relationships between the correlates and intention formation and translation. Surveys were completed by 606 HCS with 58 % (n = 353) intending to do strength exercise. HCS who were not retired (OR = 1.56, p = 0.001), were highly educated (OR = 1.32, p = 0.001), and had a favorable attitude (OR = 1.56, p exercise intention. Of those with an exercise intention, 51 % (n = 181) reported regular strength exercise. HCS with a detailed plan (OR = 1.86, p strength exercise and only half of intenders translated that intention into behavior. Interventions targeting both intention formation and translation may provide the best approach for increasing strength exercise in HCS.

  10. Integrating Norm Activation Model and Theory of Planned Behavior to Understand Sustainable Transport Behavior: Evidence from China.

    Science.gov (United States)

    Liu, Yuwei; Sheng, Hong; Mundorf, Norbert; Redding, Colleen; Ye, Yinjiao

    2017-12-18

    With increasing urbanization in China, many cities are facing serious environmental problems due to continuous and substantial increase in automobile transportation. It is becoming imperative to examine effective ways to reduce individual automobile use to facilitate sustainable transportation behavior. Empirical, theory-based research on sustainable transportation in China is limited. In this research, we propose an integrated model based on the norm activation model and the theory of planned behavior by combining normative and rational factors to predict individuals' intention to reduce car use. Data from a survey of 600 car drivers in China's three metropolitan areas was used to test the proposed model and hypotheses. Results showed that three variables, perceived norm of car-transport reduction, attitude towards reduction, and perceived behavior control over car-transport reduction, significantly affected the intention to reduce car-transport. Personal norms mediated the relationship between awareness of consequences of car-transport, ascription of responsibility of car-transport, perceived subjective norm for car-transport reduction, and intention to reduce car-transport. The results of this research not only contribute to theory development in the area of sustainable transportation behavior, but also provide a theoretical frame of reference for relevant policy-makers in urban transport management.

  11. Regime Behavior in Paleo-Reconstructed Streamflow: Attributions to Atmospheric Dynamics, Synoptic Circulation and Large-Scale Climate Teleconnection Patterns

    Science.gov (United States)

    Ravindranath, A.; Devineni, N.

    2017-12-01

    Studies have shown that streamflow behavior and dynamics have a significant link with climate and climate variability. Patterns of persistent regime behavior from extended streamflow records in many watersheds justify investigating large-scale climate mechanisms as potential drivers of hydrologic regime behavior and streamflow variability. Understanding such streamflow-climate relationships is crucial to forecasting/simulation systems and the planning and management of water resources. In this study, hidden Markov models are used with reconstructed streamflow to detect regime-like behaviors - the hidden states - and state transition phenomena. Individual extreme events and their spatial variability across the basin are then verified with the identified states. Wavelet analysis is performed to examine the signals over time in the streamflow records. Joint analyses of the climatic data in the 20th century and the identified states are undertaken to better understand the hydroclimatic connections within the basin as well as important teleconnections that influence water supply. Compositing techniques are used to identify atmospheric circulation patterns associated with identified states of streamflow. The grouping of such synoptic patterns and their frequency are then examined. Sliding time-window correlation analysis and cross-wavelet spectral analysis are performed to establish the synchronicity of basin flows to the identified synoptic and teleconnection patterns. The Missouri River Basin (MRB) is examined in this study, both as a means of better understanding the synoptic climate controls in this important watershed and as a case study for the techniques developed here. Initial wavelet analyses of reconstructed streamflow at major gauges in the MRB show multidecadal cycles in regime behavior.

  12. Applying Self-Efficacy Theory to Understanding the Behavioral Expectations of College Students with Disabilities in Requesting Accommodations

    Science.gov (United States)

    Snitker-Magin, Mikael C.

    2010-01-01

    The purpose of the study was to apply Bandura's self-efficacy theory to understanding the behavior of college students with disabilities in requesting accommodations. Students with disabilities were recruited from 20 two-year and four-year postsecondary institutions by asking student disabilities services staff to forward an email invitation to…

  13. Communication: On the origin of the non-Arrhenius behavior in water reorientation dynamics.

    Science.gov (United States)

    Stirnemann, Guillaume; Laage, Damien

    2012-07-21

    We combine molecular dynamics simulations and analytic modeling to determine the origin of the non-Arrhenius temperature dependence of liquid water's reorientation and hydrogen-bond dynamics between 235 K and 350 K. We present a quantitative model connecting hydrogen-bond exchange dynamics to local structural fluctuations, measured by the asphericity of Voronoi cells associated with each water molecule. For a fixed local structure the regular Arrhenius behavior is recovered, and the global anomalous temperature dependence is demonstrated to essentially result from a continuous shift in the unimodal structure distribution upon cooling. The non-Arrhenius behavior can thus be explained without invoking an equilibrium between distinct structures. In addition, the large width of the homogeneous structural distribution is shown to cause a growing dynamical heterogeneity and a non-exponential relaxation at low temperature.

  14. Experimental analysis of the dynamic behavior of a rotating disk submerged in water

    International Nuclear Information System (INIS)

    Presas, A; Valentín, D; Egusquiza, E; Valero, C; Seidel, U

    2014-01-01

    To study the dynamic behavior of turbine runners (natural frequencies and mode shapes) not only the added mass effect of still water has to be considered. Also the effect of rotation may not be neglected in the dynamic response. In the present study, the dynamic behavior of a rotating disk submerged in water is studied. For this purpose an experimental test rig has been developed. It consists of a rotating disk submerged in water that can be excited and its response can be measured from the rotating system by a slip ring system. For the excitation an impact device installed on the casing has been used. The response is measured with miniature accelerometers screwed on the disk. The influence of rotation on the dynamic response has been determined experimentally

  15. ALTERNATIVE EQUATIONS FOR DYNAMIC BEHAVIOR OF IONIC CHANNEL ACTIVATION AND INACTIVATION GATES

    Directory of Open Access Journals (Sweden)

    Mahmut ÖZER

    2003-03-01

    Full Text Available In this paper, alternative equations for dynamics of ionic channel activation and inactivation gates are proposed based on the path probability method. Dynamic behavior of a voltage-gated ionic channel is modeled by the conventional Hodgkin-Huxley (H-H mathematical formalism. In that model, conductance of the channel is defined in terms of activation and inactivation gates. Dynamics of the activation and inactivation gates is modeled by first-order differential equations dependent on the gate variable and the membrane potential. In the new approach proposed in this study, dynamic behavior of activation and inactivation gates is modeled by a firstorder differential equation dependent on internal energy and membrane potential by using the path probability method which is widely used in statistical physics. The new model doesn't require the time constant and steadystate values which are used explicitly in the H-H model. The numerical results show validity of the proposed method.

  16. Simulation of the Dynamic Behavior of an Asynchronous Machine Using Direct Self-Control

    Directory of Open Access Journals (Sweden)

    Cristian Paul Chioncel

    2007-01-01

    Full Text Available The paper presents the major steps that have to be gone for the implementation of the mathematical model of the asynchronous machine in SciLab / Scicos. This implemented ASM model, will be used to check the dynamic behavior of the system, the current diagrams as well as the behavior motor speed and the torque, if the input signal has a pulsation form. This implementation’s are made in Scilab / Scicos environment, a clone of the MATLAB, which provides number-crunching power similar to MATLAB, at a much better cost/performance ratio. The implemented model offers the possibility to analyze the behaviors of the asynchronous machine in different dynamic situations: speed, torques, current in motor or generator regime and to study its behavior in different possible control schemes.

  17. An overview of the crash dynamics failure behavior of metal and composite aircraft structures

    Science.gov (United States)

    Carden, Huey D.; Boitnott, Richard L.; Fasanella, Edwin L.; Jones, Lisa E.

    1991-01-01

    An overview of failure behavior results is presented from some of the crash dynamics research conducted with concepts of aircraft elements and substructure not necessarily designed or optimized for energy absorption or crash loading considerations. Experimental and analytical data are presented that indicate some general trends in the failure behavior of a class of composite structures that includes fuselage panels, individual fuselage sections, fuselage frames, skeleton subfloors with stringers and floor beams without skin covering, and subfloors with skin added to the frame stringer structure. Although the behavior is complex, a strong similarity in the static/dynamic failure behavior among these structures is illustrated through photographs of the experimental results and through analytical data of generic composite structural models.

  18. Understanding the Personality and Behavioral Mechanisms Defining Hypersexuality in Men Who Have Sex With Men.

    Science.gov (United States)

    Miner, Michael H; Romine, Rebecca Swinburne; Raymond, Nancy; Janssen, Erick; MacDonald, Angus; Coleman, Eli

    2016-09-01

    Hypersexuality has been conceptualized as sexual addiction, compulsivity, and impulsivity, among others, in the absence of strong empirical data in support of any specific conceptualization. To investigate personality factors and behavioral mechanisms that are relevant to hypersexuality in men who have sex with men. A sample of 242 men who have sex with men was recruited from various sites in a moderate-size mid-western city. Participants were assigned to a hypersexuality group or a control group using an interview similar to the Structured Clinical Interview for the Diagnostic and Statistical Manual for Mental Disorders, Fourth Edition. Self-report inventories were administered that measured the broad personality constructs of positive emotionality, negative emotionality, and constraint and more narrow constructs related to sexual behavioral control, behavioral activation, behavioral inhibition, sexual excitation, sexual inhibition, impulsivity, attention-deficit/hyperactivity disorder, and sexual behavior. Hierarchical logistic regression was used to determine the relation between these personality and behavioral variables and group membership. A hierarchical logistic regression controlling for age showed a significant positive relation between hypersexuality and negative emotionality and a negative relation with constraint. None of the behavioral mechanism variables entered this equation. However, a hierarchical multiple regression analysis predicting sexual behavioral control indicated that lack of such control was positively related to sexual excitation and sexual inhibition owing to the threat of performance failure and negatively related to sexual inhibition owing to the threat of performance consequences and general behavioral inhibition Hypersexuality was found to be related to two broad personality factors that are characterized by emotional reactivity, risk taking, and impulsivity. The associated lack of sexual behavior control is influenced by sexual

  19. Optical measurement methods to study dynamic behavior in MEMS

    Science.gov (United States)

    Rembe, Christian; Kant, Rishi; Muller, Richard S.

    2001-10-01

    The maturing designs of moving microelectromechanical systems (MEMS) make it more-and-more important to have precise measurements and visual means to characterize dynamic microstructures. The Berkeley Sensor&Actuator Center (BSAC) has a forefront project aimed at developing these capabilities and at providing high-speed Internet (Supernet) access for remote use of its facilities. Already in operation are three optical-characterization tools: a stroboscopic-interferometer system, a computer-microvision system, and a laser-Doppler vibrometer. This paper describes precision and limitations of these systems and discusses their further development. In addition, we describe the results of experimental studies on the different MEMS devices, and give an overview about high-speed visualization of rapidly moving MEMS structures.

  20. Dynamic behavior of a multi-effect sugar concentrator system

    International Nuclear Information System (INIS)

    Aly, N.H.; Marwan, M.A.

    1994-01-01

    A transient mathematical model is developed to simulate the dynamic response of multi effect evaporator for sugar distiller concentrators at delta company, Egypt. Based on the mass and energy balance equations, a non linear mathematical model relating the system variables is obtained. This model allows to investigate the response of the unit parameters in both steady state and transient operating condition. Also, the response of the unit to perturbations in feed syrup, flow rate, concentration and heating steam temperature is studied. The predicted response based on the solution of the mathematical model is illustrated. The developed model proved to be efficient and capable to predict different operating conditions at steady state or transients variations. The study shows that an increase in heating steam temperature can be a critical factor due to caramelization of the syrup. 1 tab., 10 fig

  1. Glassy behavior and dynamic tweed in defect-free multiferroics

    Science.gov (United States)

    Wang, Xiaofei; Salje, Ekhard K. H.; Sun, Jun; Ding, Xiangdong

    2018-01-01

    Multiferroics often show significant elastic fluctuations even when the transition is strongly stepwise. Molecular dynamics simulations of a generic toy model show the appearance of tweed nanostructures (cross hatched patterns) in the paraelastic phase just above the transition point. This tweed lowers the elastic modulus C12 when approaching the transition temperature. The spatial and temporal correlations of the tweed structure follow the Vogel-Fulcher relationship, and the Vogel-Fulcher temperature is slightly below the transition temperature Ttrans, preventing this glassy state to freeze completely. Spatial correlations of shear strain show that the size of tweed patches reaches about eight lattice spacings near Ttrans. Cross- and rod-shaped diffuse scattering, similar to that in relaxors, emerges around {hh0}* and {h00}* Bragg reflections. The viscosity of the sample increases dramatically at the transition point with a significant precursor increase in the tweed regime.

  2. Finite element analysis of the dynamic behavior of pear under impact loading

    Directory of Open Access Journals (Sweden)

    Alireza Salarikia

    2017-03-01

    Full Text Available Pear fruit is susceptible to bruising from mechanical impact during field harvesting operations and at all stages of postharvest handling. The postharvest shelf life of bruised fruits were shorter, and they softened rapidly under cold storage compared with non-bruised samples. Developing strategies for reducing bruising during the supply chain requires an understanding of fruit dynamic behavior to different enforced loadings. Finite Element Method (FEM is among the best techniques, in terms of accuracy and cost-efficiency, for studying the factors effective in impact-induced bruising. In this research, the drop test of pear sample was simulated using FEM. The simulation was conducted on a 3D solid model of the pear that was created by using non-contact optical scanning technology. This computer-based study aimed to assess the stress and strain distribution patterns within pear generated by collision of the fruit with a flat surface made of different materials. The contact force between two colliding surfaces is also investigated. The simulations were conducted at two different drop orientations and four different impact surfaces. Results showed that, in both drop orientations, the largest and smallest stresses, strains and contact forces were developed in collision with the steel and rubber surfaces, respectively. In general, these parameters were smaller when fruit collided with the surfaces along its horizontal axis than when collided along its vertical axis. Finally, analyses of stress and strain magnitudes showed that simulation stress and strain values were compatible with experiments data.

  3. Appreciating the ties that bind technical communication to culture: A dynamic model to help us understand differences in discourse structure

    DEFF Research Database (Denmark)

    Kastberg, Peter; Kampf, Constance

    In order to support an explicit understanding of cultural patterns as both dynamic and structured, we will examine Hofstede?s model for stabilization of cultural patterns, and use this model to explore some cultural consequences for patterns of logic and signs that influence the effectiveness of ...

  4. DYNAMIC BEHAVIOR OF CONCRETE GRAVITY DAM ON JOINTED ROCK FOUNDATION DURING LARGE-SCALE EARTHQUAKE

    Science.gov (United States)

    Kimata, Hiroyuki; Fujita, Yutaka; Horii, Hideyuki; Yazdani, Mahmoud

    Dynamic cracking analysis of concrete gravity dam has been carried out during large-scale earthquake, considering the progressive failure of jointed rock foundation. Firstly, in order to take into account the progressive failure of rock foundation, the constitutive law of jointed rock is assumed and its validity is evaluated by simulation analysis based on the past experimental model. Finally, dynamic cracking analysis of 100-m high dam model is performed, using the previously proposed approach with tangent stiffness-proportional damping to express the propagation behavior of crack and the constitutive law of jointed rock. The crack propagation behavior of dam body and the progressive failure of jointed rock foundation are investigated.

  5. Research on mechanical behavior of casting slab during dynamic soft reduction

    Science.gov (United States)

    Qin, Qin; Huang, Jianlin; Zhou, Daomou; Yang, Xiaoying

    2017-10-01

    A three-dimensional dynamic solidification model incorporating the thermo-elastic-plastic coupling model has been proposed in this paper by ABAQUS considering the dynamic contact between the slab and rolls. The thermo-mechanical coupling model produces outputs such as temperature and mechanical behavior of the slab. And the stress-strain distribution of the high-temperature slab at the solidification end has been investigated in this paper. The influences of various reduction interval, reduction amount and reduction distribution on mechanical behavior of casting slab have been systematically discussed.

  6. Learning the condition of satisfaction of an elementary behavior in dynamic field theory

    OpenAIRE

    Luciw, M; Kazerounian, S; Lahkman, K; Richter, M; Sandamirskaya, Y

    2015-01-01

    In order to proceed along an action sequence, an autonomous agent has to recognize that the intended final condition of the previous action has been achieved. In previous work, we have shown how a sequence of actions can be generated by an embodied agent using a neural-dynamic architecture for behavioral organization, in which each action has an intention and condition of satisfaction. These components are represented by dynamic neural fields, and are coupled to motors...

  7. Track dynamic behavior at rail welds at high speed

    Science.gov (United States)

    Xiao, Guangwen; Xiao, Xinbiao; Guo, Jun; Wen, Zefeng; Jin, Xuesong

    2010-06-01

    As a vehicle passing through a track with different weld irregularities, the dynamic performance of track components is investigated in detail by using a coupled vehicle-track model. In the model, the vehicle is modeled as a multi-body system with 35 degrees of freedom, and a Timoshenko beam is used to model the rails which are discretely supported by sleepers. In the track model, the sleepers are modeled as rigid bodies accounting for their vertical, lateral and rolling motions and assumed to move backward at a constant speed to simulate the vehicle running along the track at the same speed. In the study of the coupled vehicle and track dynamics, the Hertizian contact theory and the theory proposed by Shen-Hedrick-Elkins are, respectively, used to calculate normal and creep forces between the wheel and the rails. In the calculation of the normal forces, the coefficient of the normal contact stiffness is determined by transient contact condition of the wheel and rail surface. In the calculation of the creepages, the lateral, roll-over motions of the rail and the fact that the relative velocity between the wheel and rail in their common normal direction is equal to zero are simultaneously taken into account. The motion equations of the vehicle and track are solved by means of an explicit integration method, in which the rail weld irregularities are modeled as local track vertical deviations described by some ideal cosine functions. The effects of the train speed, the axle load, the wavelength and depth of the irregularities, and the weld center position in a sleeper span on the wheel-rail impact loading are analyzed. The numerical results obtained are greatly useful in the tolerance design of welded rail profile irregularity caused by hand-grinding after rail welding and track maintenances.

  8. Evaluation of dynamic behavior of waffle slab to gym center

    Directory of Open Access Journals (Sweden)

    Yuri Cláudio Vieira da Costa

    Full Text Available In Brazil, the use of reinforced concrete waffle slab in multi-story buildings is widespread nowadays. These buildings are projected for different purposes such as fitness centers, supermarkets, parking garages, offices and residential units. Simple activities as walking, skipping and jumping can generate vibrations in these slabs. Vibrations can cause inconvenience in persons, questions about structure´s safety, and collapse risk that it is determined by its intensity of vibrations. The objective of this paper is evaluating the behavior of reinforced concrete waffle slabs due to the human rhythmic activities. Slabs are modeled by finite elements method using the SAP2000 program. The results are verified according to Brazilian and international codes. The waffle slabs are submitted to high-levels of acceleration and velocity generating discomfort in users.

  9. Statistical behavior of time dynamics evolution of HIV infection

    Science.gov (United States)

    González, Ramón E. R.; Santos, Iury A. X.; Nunes, Marcos G. P.; de Oliveira, Viviane M.; Barbosa, Anderson L. R.

    2017-09-01

    We use the tools of the random matrix theory (RMT) to investigate the statistical behavior of the evolution of human immunodeficiency virus (HIV) infection. By means of the nearest-neighbor spacing distribution we have identified four distinct regimes of the evolution of HIV infection. We verified that at the beginning of the so-called clinical latency phase the concentration of infected cells grows slowly and evolves in a correlated way. This regime is followed by another one in which the correlation is lost and that in turn leads the system to a regime in which the increase of infected cells is faster and correlated. In the final phase, the one in which acquired immunodeficiency syndrome (AIDS) is stablished, the system presents maximum correlation as demonstrated by GOE distribution.

  10. Understanding work-related social media use: An extension of theory of planned behavior.

    NARCIS (Netherlands)

    van Zoonen, W.; Verhoeven, J.W.M.; Elving, W.J.L.

    2014-01-01

    This study examines the motives of employees to engage in work related social media use - i.e. the use of personal social media accounts to communicate about work-related issues. The theory of planned behavior (TPB) was used to explain this behavior. Because social media can enable users to express

  11. Understanding mechanisms of change in the development of antisocial behavior: The impact of a universal intervention

    NARCIS (Netherlands)

    P.A.C. van Lier (Pol); P. Vuijk (Patricia); A.A.M. Crijnen (Alfons)

    2005-01-01

    textabstractThe association between the development of antisocial behavior, affiliation with deviant friends, and peer rejection was tested with a preventive intervention; 664 boys and girls were randomly assigned to a universal classroom-based intervention targeting disruptive behavior or a control

  12. Chemical approaches to understanding the environmental behavior of Pu, Np, and Tc

    International Nuclear Information System (INIS)

    Bondietti, E.A.

    1978-01-01

    Some topics discussed are as follows: speciation behavior of Pu, Np, and Tc; thermodynamic and radiochemical behavior; sorption studies with soils; Pu oxidation states in fresh water; Np oxidation states in soils; effect of oxidation state of Tc on environmental transport predictions; and thermodynamic calculations of Tc speciation

  13. Parental Cognitions, Parental Behavior, and the Child's Understanding of the Parent-Child Relationship.

    Science.gov (United States)

    Dekovic, Maja; And Others

    1991-01-01

    Studied the relationship of parental reasoning complexity to parental behavior during parent-child interactions, and the effect of this relationship on children's social cognitions. Results indicate that parental reasoning complexity is related to parental behaviors of restrictive control, authoritative control, and support, which, in turn, are…

  14. Understanding Soccer Team Supporters' Behavior and Culture in a Globalized Society from Social Learning Theory

    Science.gov (United States)

    Lee, Seungbum; Han, Keunsu

    2012-01-01

    Whereas there have been many academic studies on European soccer team supporters, relatively few studies have looked at supporters in Asia, especially regarding their supporting behavior and culture. Broadly, the purpose of this paper is to describe the behavior and culture of supporters of the Korean professional soccer league (K-League).…

  15. Dynamical Approach Study of Spurious Steady-State Numerical Solutions of Nonlinear Differential Equations. 2; Global Asymptotic Behavior of Time Discretizations; 2. Global Asymptotic Behavior of time Discretizations

    Science.gov (United States)

    Yee, H. C.; Sweby, P. K.

    1995-01-01

    The global asymptotic nonlinear behavior of 1 1 explicit and implicit time discretizations for four 2 x 2 systems of first-order autonomous nonlinear ordinary differential equations (ODES) is analyzed. The objectives are to gain a basic understanding of the difference in the dynamics of numerics between the scalars and systems of nonlinear autonomous ODEs and to set a baseline global asymptotic solution behavior of these schemes for practical computations in computational fluid dynamics. We show how 'numerical' basins of attraction can complement the bifurcation diagrams in gaining more detailed global asymptotic behavior of time discretizations for nonlinear differential equations (DEs). We show how in the presence of spurious asymptotes the basins of the true stable steady states can be segmented by the basins of the spurious stable and unstable asymptotes. One major consequence of this phenomenon which is not commonly known is that this spurious behavior can result in a dramatic distortion and, in most cases, a dramatic shrinkage and segmentation of the basin of attraction of the true solution for finite time steps. Such distortion, shrinkage and segmentation of the numerical basins of attraction will occur regardless of the stability of the spurious asymptotes, and will occur for unconditionally stable implicit linear multistep methods. In other words, for the same (common) steady-state solution the associated basin of attraction of the DE might be very different from the discretized counterparts and the numerical basin of attraction can be very different from numerical method to numerical method. The results can be used as an explanation for possible causes of error, and slow convergence and nonconvergence of steady-state numerical solutions when using the time-dependent approach for nonlinear hyperbolic or parabolic PDES.

  16. Poverty dynamics in Germany: Evidence on the relationship between persistent poverty and health behavior.

    Science.gov (United States)

    Aue, Katja; Roosen, Jutta; Jensen, Helen H

    2016-03-01

    Previous studies have found poverty to be related to lower levels of health due to poor health behavior such as unhealthy eating, smoking or less physical activity. Longer periods of poverty seem to be especially harmful for individual health behavior. Studies have shown that poverty has a dynamic character. Moreover, poverty is increasingly regarded as being a multidimensional construct and one that considers more aspects than income alone. Against this background this paper analyzes the relationship between health behavior and persistent spells of income poverty as well as a combined poverty indicator using data of the German Socio-Economic Panel (2000-2010). Next to cross-sectional logistic regression models we estimate fixed-effects models to analyze the effect of persistent poverty on dietary behavior, tobacco consumption, and physical activity. Cross-sectional results suggest that persistent poverty is related to poor health behavior, particularly regarding tobacco consumption and physical activity. Results also show that multidimensional and dynamic aspects of poverty matter. Complementary panel analyses reveal negative effects for the combined poverty indicator only for dietary behavior in the total sample. However, by analyzing the sample by gender we identify further effects of persistent poverty on health behavior. The analyses show that not only do individuals in poverty but also those in precarious situations show health-damaging behavior more often. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Dynamic psychotherapy or dialectical behavioral therapy-- which is better for borderline personality disorder?

    Science.gov (United States)

    Tene, O; Har-Even, A; Dahan, E; Babokshin, Y; Reuveni, I; Ponarovsky, B; Rosman, V; Gluzman, L

    2011-01-01

    Clinical dilemma: A 20-year-old female patient, diagnosed as suffering from borderline personality disorder, is referred to your clinic. Her disorder is characterized by unstable personal relationships, impulsivity, suicidal behavior, emotional instability and pan-anxiety. After initiation of pharmacological treatment which you have chosen, you meet with her parents who ask you which is better for their daughter dynamic-analytic psychotherapy or dialectical behavioral therapy.

  18. Dynamical Integration of Language and Behavior in a Recurrent Neural Network for Human-Robot Interaction.

    Science.gov (United States)

    Yamada, Tatsuro; Murata, Shingo; Arie, Hiroaki; Ogata, Tetsuya

    2016-01-01

    To work cooperatively with humans by using language, robots must not only acquire a mapping between language and their behavior but also autonomously utilize the mapping in appropriate contexts of interactive tasks online. To this end, we propose a novel learning method linking language to robot behavior by means of a recurrent neural network. In this method, the network learns from correct examples of the imposed task that are given not as explicitly separated sets of language and behavior but as sequential data constructed from the actual temporal flow of the task. By doing this, the internal dynamics of the network models both language-behavior relationships and the temporal patterns of interaction. Here, "internal dynamics" refers to the time development of the system defined on the fixed-dimensional space of the internal states of the context layer. Thus, in the execution phase, by constantly representing where in the interaction context it is as its current state, the network autonomously switches between recognition and generation phases without any explicit signs and utilizes the acquired mapping in appropriate contexts. To evaluate our method, we conducted an experiment in which a robot generates appropriate behavior responding to a human's linguistic instruction. After learning, the network actually formed the attractor structure representing both language-behavior relationships and the task's temporal pattern in its internal dynamics. In the dynamics, language-behavior mapping was achieved by the branching structure. Repetition of human's instruction and robot's behavioral response was represented as the cyclic structure, and besides, waiting to a subsequent instruction was represented as the fixed-point attractor. Thanks to this structure, the robot was able to interact online with a human concerning the given task by autonomously switching phases.

  19. Dynamical Integration of Language and Behavior in a Recurrent Neural Network for Human--Robot Interaction

    Directory of Open Access Journals (Sweden)

    Tatsuro Yamada

    2016-07-01

    Full Text Available To work cooperatively with humans by using language, robots must not only acquire a mapping between language and their behavior but also autonomously utilize the mapping in appropriate contexts of interactive tasks online. To this end, we propose a novel learning method linking language to robot behavior by means of a recurrent neural network. In this method, the network learns from correct examples of the imposed task that are given not as explicitly separated sets of language and behavior but as sequential data constructed from the actual temporal flow of the task. By doing this, the internal dynamics of the network models both language--behavior relationships and the temporal patterns of interaction. Here, ``internal dynamics'' refers to the time development of the system defined on the fixed-dimensional space of the internal states of the context layer. Thus, in the execution phase, by constantly representing where in the interaction context it is as its current state, the network autonomously switches between recognition and generation phases without any explicit signs and utilizes the acquired mapping in appropriate contexts. To evaluate our method, we conducted an experiment in which a robot generates appropriate behavior responding to a human's linguistic instruction. After learning, the network actually formed the attractor structure representing both language--behavior relationships and the task's temporal pattern in its internal dynamics. In the dynamics, language--behavior mapping was achieved by the branching structure. Repetition of human's instruction and robot's behavioral response was represented as the cyclic structure, and besides, waiting to a subsequent instruction was represented as the fixed-point attractor. Thanks to this structure, the robot was able to interact online with a human concerning the given task by autonomously switching phases.

  20. Sliding Dynamics of Parallel Graphene Sheets: Effect of Geometry and Van Der Waals Interactions on Nano-Spring Behavior

    Directory of Open Access Journals (Sweden)

    Alessandro Crisafulli

    2018-03-01

    Full Text Available Graphene and carbon nanotubes are promising materials for nanoelectromechanical systems. Among other aspects, a proper understanding of the sliding dynamics of parallel graphene sheets or concentric nanotubes is of crucial importance for the design of nano-springs. Here, we analytically investigate the sliding dynamics between two parallel, rigid graphene sheets. In particular, the analysis focuses on configurations in which the distance between the sheets is kept constant and lower than the equilibrium interlayer spacing of graphite (unstable configurations. The aim is to understand how the interlayer force due to van der Waals interactions along the sliding direction changes with the geometrical characteristics of the configuration, namely size and interlayer spacing. Results show metastable equilibrium positions with completely faced sheets, namely a null force along the sliding direction, whereas net negative/positive forces arise when the sheets are approaching/leaving each other. This behavior resembles a molecular spring, being able to convert kinetic into potential energy (van der Waals potential, and viceversa. The amplitude of both storable energy and entrance/exit forces is found to be proportional to the sheet size, and inversely proportional to their interlayer spacing. This model could also be generalized to describe the behavior of configurations made of concentric carbon nanotubes, therefore allowing a rational design of some elements of carbon-based nanoelectromechanical systems.