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Sample records for model positing indirect

  1. THE POSITION OF INDIRECT EVIDENCE AS VERIFICATION TOOLS IN THE CARTEL CASE

    Directory of Open Access Journals (Sweden)

    Veri Antoni

    2014-06-01

    Full Text Available Indirect (circumstantial evidence, either economic evidence or communication evidence, has been used in cartel cases in many countries such as United States of America, Japan, Australia, Brazil, Malaysia, and others. According to Indonesia criminal procedure law, the position of indirect (circumstantial evidence is categorized as an indication (clue evidence whereas according to Indonesia civil procedure law, indirect (circumstantial evidence is categorized as presumption. Considering the characteristics the antimonopoly law which aims to find material truth, the position of indirect evidence is more properly said to be an indication. Owing to its status as an indication, indirect evidence should be exhibited together with the other direct evidence. Indirect evidenceatau bukti tidak langsung, baik bukti ekonomi atau bukti komunikasi, telah digunakan dalam kasus-kasus kartel di banyak negara, seperti Amerika Serikat, Jepang, Australia, Brazil, Malaysia, dan lain-lain. Menurut hukum acara pidana Indonesia, posisi bukti tidak langsung dikategorikan sebagai indikasi (bukti petunjuk, padahal menurut hukum acara perdata Indonesia, bukti tidak langsung dikategorikan sebagai praduga. Mengingat karakteristik hukum anti-monopoli yang bertujuan untuk mencari kebenaran materiil, posisi bukti tidak langsung lebih tepat dikatakan indikasi. Karena statusnya sebagai indikasi, bukti tidak langsung harus dipamerkan bersama dengan bukti langsung lainnya.

  2. THE POSITION OF INDIRECT EVIDENCE AS VERIFICATION TOOLS IN THE CARTEL CASE

    Directory of Open Access Journals (Sweden)

    Veri Antoni

    2014-06-01

    Full Text Available Indirect (circumstantial evidence, either economic evidence or communication evidence, has been used in cartel cases in many countries such as United States of America, Japan, Australia, Brazil, Malaysia, and others. According to Indonesia criminal procedure law, the position of indirect (circumstantial evidence is categorized as an indication (clue evidence whereas according to Indonesia civil procedure law, indirect (circumstantial evidence is categorized as presumption. Considering the characteristics the antimonopoly law which aims to find material truth, the position of indirect evidence is more properly said to be an indication. Owing to its status as an indication, indirect evidence should be exhibited together with the other direct evidence.   Indirect evidenceatau bukti tidak langsung, baik bukti ekonomi atau bukti komunikasi, telah digunakan dalam kasus-kasus kartel di banyak negara, seperti Amerika Serikat, Jepang, Australia, Brazil, Malaysia, dan lain-lain. Menurut hukum acara pidana Indonesia, posisi bukti tidak langsung dikategorikan sebagai indikasi (bukti petunjuk, padahal menurut hukum acara perdata Indonesia, bukti tidak langsung dikategorikan sebagai praduga. Mengingat karakteristik hukum anti-monopoli yang bertujuan untuk mencari kebenaran materiil, posisi bukti tidak langsung lebih tepat dikatakan indikasi. Karena statusnya sebagai indikasi, bukti tidak langsung harus dipamerkan bersama dengan bukti langsung lainnya.

  3. Indirect Global Warming Potentials of Halons Using Atmospheric Models

    Science.gov (United States)

    Youn, D.; Patten, K. O.; Wuebbles, D. J.

    2007-05-01

    Emission of bromochlorofluorocarbons, or Halons, results in stratospheric ozone depletion. This leads to cooling of the climate system in the opposite direction to direct warming contribution of the Halons as greenhouse gases. This cooling is a key indirect effect of Halons on radiative forcing or climate. The Global Warming Potential (GWP) is a relative index used to compare the climate impact of an emitted greenhouse gas, relative to an equal amount of carbon dioxide. Until now, indirect GWPs have been calculated based on the concept of Equivalent Effective Stratospheric Chlorine (EESC), which oversimplifies the complex processes in the atmosphere. As a step towards obtaining indirect GWPs through a more robust approach, 2-D and 3-D global chemical transport models (CTM) were used as the computational tool to derive more realistic ozone changes caused by pulse perturbation of Halons at the surface. Indirect GWPs of Halon-1211 and -1301 for a 100-year time horizon were explicitly calculated based on the University of Illinois at Urbana-Champaign (UIUC) 2-D global CTM and radiative transport model (RTM) and the 3-D CTM, MOZART-3.1. The 2-D and 3-D model simulations show acceptable temporal variations in the atmosphere as well as derived lifetimes and direct GWP values of the Halons. The 2-D model-based indirect GWPs for a 100-year horizon are -16,294 for Halon-1211 and -33,648 for Halon-1301. 3-D indirect GWP for Halon-1211 is -18,216. The indirect GWPs for Halon-1211 presented here are much smaller than previous published results using the previous simplified appraoch.

  4. Rotor Position Detection of Switched Reluctance Motors with a New Indirect Technique

    Directory of Open Access Journals (Sweden)

    Majid Asgar

    2014-09-01

    Full Text Available The aligned to unaligned phase inductance ratio and the number of stator and rotor poles strongly affect the resolution of indirect rotor position sensing methods for switched reluctance motor (SRM drives. This paper presents a new sensor-less rotor position detection for a three-phase single switch SR motor with regeneration capability at standstill mode.. The proposed method is based on the dependency of phase current waveform at turn off time to rotor position angle. It is shown that the combination of a motor with single switch per phase converter and a transient voltage suppressor (TVS circuit define a resonant circuit. In this method, the rotor position is achieved by inspecting of regeneration current results of applied high frequency and low level diagnostic pulses to the motor phases at the beginning step. Obtaining the rotor position of switched reluctance motors (SRMs will done by means of the overlap of rising voltage measurements. During this interval, rotor position is detected by exchanging energy between the phase and source repeatedly in one cycle of a phase current. The resulted current magnitudes are measured and compared to detect the rotor position. The prototype controller was simulated, fabricated, and tested in laboratory and experimental results of the proposed SRM drive system are presented. The new configuration enables the motor for self-starting without any other mechanism or starting device.

  5. Hidden Markov Models for indirect classification of occupant behaviour

    DEFF Research Database (Denmark)

    Liisberg, Jon Anders Reichert; Møller, Jan Kloppenborg; Bloem, H.

    2016-01-01

    Even for similar residential buildings, a huge variability in the energy consumption can be observed. This variability is mainly due to the different behaviours of the occupants and this impacts the thermal (temperature setting, window opening, etc.) as well as the electrical (appliances, TV....... This paper focuses on the use of Hidden Markov Models (HMMs) to create methods for indirect observations and characterisation of occupant behaviour. By applying homogeneous HMMs on the electricity consumption of fourteen apartments, three states describing the data were found suitable. The most likely...

  6. MAPPING GNSS RESTRICTED ENVIRONMENTS WITH A DRONE TANDEM AND INDIRECT POSITION CONTROL

    Directory of Open Access Journals (Sweden)

    E. Cledat

    2017-08-01

    Full Text Available The problem of autonomously mapping highly cluttered environments, such as urban and natural canyons, is intractable with the current UAV technology. The reason lies in the absence or unreliability of GNSS signals due to partial sky occlusion or multi-path effects. High quality carrier-phase observations are also required in efficient mapping paradigms, such as Assisted Aerial Triangulation, to achieve high ground accuracy without the need of dense networks of ground control points. In this work we consider a drone tandem in which the first drone flies outside the canyon, where GNSS constellation is ideal, visually tracks the second drone and provides an indirect position control for it. This enables both autonomous guidance and accurate mapping of GNSS restricted environments without the need of ground control points. We address the technical feasibility of this concept considering preliminary real-world experiments in comparable conditions and we perform a mapping accuracy prediction based on a simulation scenario.

  7. Simulink Implementation of Indirect Vector Control of Induction Machine Model

    Directory of Open Access Journals (Sweden)

    V. Dhanunjayanaidu

    2014-04-01

    Full Text Available In this paper, a modular Simulink implementation of an induction machine model is described in a step-by-step approach. With the modular system, each block solves one of the model equations; therefore, unlike in black box models, all of the machine parameters are accessible for control and verification purposes.After the implementation, examples are given with the model used in different drive applications, such as open-loop constant V/Hz control and indirect vector control. To implement the induction machine model, the dynamic equivalent circuit of induction motor is taken and the model equations in flux linkage form are derived.Then the model is implemented in Simulink by transforming three phase voltages to d-q frame and the d-q currents back to three phase, also it includes unit vector calculation and induction machine d-q model.The inputs here are three phase voltages, load torque, speed of stator and the outputs are flux linkages and currents, electrical torque and speed of rotor.

  8. Indirect Effects of Attributional Style for Positive Events on Depressive Symptoms Through Self-Esteem During Early Adolescence.

    Science.gov (United States)

    Rueger, Sandra Yu; George, Rachel

    2017-04-01

    Research on adolescent depression has overwhelmingly focused on risk factors, such as stressful negative events and cognitive vulnerabilities, but much important information can be gained by focusing on protective factors. Thus, the current study aimed to broaden understanding on adolescent depression by considering the role of two positive elements as protective factors, attributional style for positive events and self-esteem, in a model of depression. The sample included 491 middle school students (52 % female; n = 249) with an age range from 12 to 15 years (M = 13.2, SD = .70). The sample was ethnically/racially diverse, with 55 % White, 22 % Hispanic, 10 % Asian American, 3 % African American, and 10 % Biracial/Other. Correlational analyses indicated significant cross-sectional and longitudinal associations between an enhancing attributional style (internal, stable, global attributions for positive events), self-esteem and depressive symptoms. Further, prospective analyses using bootstrapping methodology demonstrated significant indirect effects of an enhancing attributional style on decreases in depressive symptoms through its effects on self-esteem. These findings highlight the importance of considering attributional style for positive events as a protective factor in the developmental course of depressive symptoms during early adolescence.

  9. Indirect field-oriented control of induction motors is globally asymptotically stable when used to regulate position in rigid robots

    Science.gov (United States)

    Hernández-Guzmán, Victor M.; Santibáñez, Victor; Silva-Ortigoza, Ramón

    2010-10-01

    In this note we prove, for the first time, that indirect field-oriented control of voltage-fed induction motors achieves global asymptotic stability when used to regulate position in rigid robots. This results in the simplest controller proposed until now to solve this problem. Our stability analysis considers inner current loops driven by linear PI controllers and an external position loop driven by a saturated PD controller.

  10. Expanding the developmental models of writing: A direct and indirect effects model of developmental writing (DIEW).

    Science.gov (United States)

    Kim, Young-Suk Grace; Schatschneider, Christopher

    2017-01-01

    We investigated direct and indirect effects of component skills on writing (DIEW) using data from 193 children in Grade 1. In this model, working memory was hypothesized to be a foundational cognitive ability for language and cognitive skills as well as transcription skills, which, in turn, contribute to writing. Foundational oral language skills (vocabulary and grammatical knowledge) and higher-order cognitive skills (inference and theory of mind) were hypothesized to be component skills of text generation (i.e., discourse-level oral language). Results from structural equation modeling largely supported a complete mediation model among four variations of the DIEW model. Discourse-level oral language, spelling, and handwriting fluency completely mediated the relations of higher-order cognitive skills, foundational oral language, and working memory to writing. Moreover, language and cognitive skills had both direct and indirect relations to discourse-level oral language. Total effects, including direct and indirect effects, were substantial for discourse-level oral language (.46), working memory (.43), and spelling (.37), followed by vocabulary (.19), handwriting (.17), theory of mind (.12), inference (.10), and grammatical knowledge (.10). The model explained approximately 67% of variance in writing quality. These results indicate that multiple language and cognitive skills make direct and indirect contributions, and it is important to consider both direct and indirect pathways of influences when considering skills that are important to writing.

  11. An Indirect Effects Model of the Association between Poverty and Child Functioning: The Role of Children's Poverty-Related Stress

    Science.gov (United States)

    Wadsworth, Martha E.; Raviv, Tali; Reinhard, Christine; Wolff, Brian; Santiago, Catherine DeCarlo; Einhorn, Lindsey

    2008-01-01

    The authors tested a theoretical model positing that poverty has an indirect effect on child and adolescent functioning through children's poverty-related stress. Path analyses with a multiethnic sample of 164 children aged 6 to 18 revealed that the stress associated with poverty, such as economic strain, family conflict, violence/trauma, and…

  12. Expanding the Developmental Models of Writing: A Direct and Indirect Effects Model of Developmental Writing (DIEW)

    Science.gov (United States)

    Kim, Young-Suk Grace; Schatschneider, Christopher

    2017-01-01

    We investigated direct and indirect effects of component skills on writing (DIEW) using data from 193 children in Grade 1. In this model, working memory was hypothesized to be a foundational cognitive ability for language and cognitive skills as well as transcription skills, which, in turn, contribute to writing. Foundational oral language skills…

  13. Expanding the Developmental Models of Writing: A Direct and Indirect Effects Model of Developmental Writing (DIEW)

    Science.gov (United States)

    Kim, Young-Suk Grace; Schatschneider, Christopher

    2017-01-01

    We investigated direct and indirect effects of component skills on writing (DIEW) using data from 193 children in Grade 1. In this model, working memory was hypothesized to be a foundational cognitive ability for language and cognitive skills as well as transcription skills, which, in turn, contribute to writing. Foundational oral language skills…

  14. Aerosol indirect effects in a multi-scale aerosol-climate model PNNL-MMF

    Directory of Open Access Journals (Sweden)

    M. Wang

    2011-06-01

    concentrations from PI to PD in the MMF (about 26 % smaller than that in CAM5. The smaller relative increase in CCN concentrations in the MMF is caused in part by a smaller increase in aerosol lifetime from PI to PD in the MMF, a positive feedback in aerosol indirect effects induced by cloud lifetime effects from aerosols. The smaller response in LWP to anthropogenic aerosols in the MMF model is consistent with observations and with high resolution model studies, which may indicate that aerosol indirect effects simulated in conventional global climate models are overestimated and point to the need to use global high resolution models, such as MMF models or global CRMs, to study aerosol indirect effects. The simulated total anthropogenic aerosol effect in the MMF is −1.05 W m−2, which is close to the Murphy et al. (2009 inverse estimate of −1.1±0.4 W m−2 (1σ based on the examination of the Earth's energy balance. Further improvements in the representation of ice nucleation and low clouds in MMF are needed to refine the aerosol indirect effect estimate.

  15. Aerosol indirect effects -- general circulation model intercomparison and evaluation with satellite data

    Energy Technology Data Exchange (ETDEWEB)

    Quaas, Johannes; Ming, Yi; Menon, Surabi; Takemura, Toshihiko; Wang, Minghuai; Penner, Joyce E.; Gettelman, Andrew; Lohmann, Ulrike; Bellouin, Nicolas; Boucher, Olivier; Sayer, Andrew M.; Thomas, Gareth E.; McComiskey, Allison; Feingold, Graham; Hoose, Corinna; Kristjansson, Jon Egill; Liu, Xiaohong; Balkanski, Yves; Donner, Leo J.; Ginoux, Paul A.; Stier, Philip; Feichter, Johann; Sednev, Igor; Bauer, Susanne E.; Koch, Dorothy; Grainger, Roy G.; Kirkevag, Alf; Iversen, Trond; Seland, Oyvind; Easter, Richard; Ghan, Steven J.; Rasch, Philip J.; Morrison, Hugh; Lamarque, Jean-Francois; Iacono, Michael J.; Kinne, Stefan; Schulz, Michael

    2009-04-10

    Aerosol indirect effects continue to constitute one of the most important uncertainties for anthropogenic climate perturbations. Within the international AEROCOM initiative, the representation of aerosol-cloud-radiation interactions in ten different general circulation models (GCMs) is evaluated using three satellite datasets. The focus is on stratiform liquid water clouds since most GCMs do not include ice nucleation effects, and none of the model explicitly parameterizes aerosol effects on convective clouds. We compute statistical relationships between aerosol optical depth (Ta) and various cloud and radiation quantities in a manner that is consistent between the models and the satellite data. It is found that the model-simulated influence of aerosols on cloud droplet number concentration (Nd) compares relatively well to the satellite data at least over the ocean. The relationship between Ta and liquid water path is simulated much too strongly by the models. It is shown that this is partly related to the representation of the second aerosol indirect effect in terms of autoconversion. A positive relationship between total cloud fraction (fcld) and Ta as found in the satellite data is simulated by the majority of the models, albeit less strongly than that in the satellite data in most of them. In a discussion of the hypotheses proposed in the literature to explain the satellite-derived strong fcld - Ta relationship, our results indicate that none can be identified as unique explanation. Relationships similar to the ones found in satellite data between Ta and cloud top temperature or outgoing long-wave radiation (OLR) are simulated by only a few GCMs. The GCMs that simulate a negative OLR - Ta relationship show a strong positive correlation between Ta and fcld The short-wave total aerosol radiative forcing as simulated by the GCMs is strongly influenced by the simulated anthropogenic fraction of Ta, and parameterisation assumptions such as a lower bound on Nd

  16. Asymptotic and resampling strategies for assessing and comparing indirect effects in multiple mediator models

    National Research Council Canada - National Science Library

    Preacher, Kristopher J; Hayes, Andrew F

    2008-01-01

    .... We provide an overview of simple and multiple mediation and explore three approaches that can be used to investigate indirect processes, as well as methods for contrasting two or more mediators within a single model...

  17. The indirect consequences of a mutualism: comparing positive and negative components of the net interaction between honeydew-tending ants and host plants.

    Science.gov (United States)

    Grinath, Joshua B; Inouye, Brian D; Underwood, Nora; Billick, Ian

    2012-03-01

    1. In ecological webs, net indirect interactions between species are composed of interactions that vary in sign and magnitude. Most studies have focused on negative component interactions (e.g. predation, herbivory) without considering the relative importance of positive interactions (e.g. mutualism, facilitation) for determining net indirect effects. 2. In plant/arthropod communities, ants have multiple top-down effects via mutualisms with honeydew-producing herbivores and harassment of and predation on other herbivores; these ant effects provide opportunities for testing the relative importance of positive and negative interspecific interactions. We manipulated the presence of ants, honeydew-producing membracids and leaf-chewing beetles on perennial host plants in field experiments in Colorado to quantify the relative strength of these different types of interactions and their impact on the ant's net indirect effect on plants. 3. In 2007, we demonstrated that ants simultaneously had a positive effect on membracids and a negative effect on beetles, resulting in less beetle damage on plants hosting the mutualism. 4. In 2008, we used structural equation modelling to describe interaction strengths through the entire insect herbivore community on plants with and without ants. The ant's mutualism with membracids was the sole strong interaction contributing to the net indirect effect of ants on plants. Predation, herbivory and facilitation were weak, and the net effect of ants reduced plant reproduction. This net indirect effect was also partially because of behavioural changes of herbivores in the presence of ants. An additional membracid manipulation showed that the membracid's effect on ant activity was largely responsible for the ant's net effect on plants; ant workers were nearly ten times as abundant on plants with mutualists, and effects on other herbivores were similar to those in the ant manipulation experiment. 5. These results demonstrate that mutualisms can

  18. Aerosol indirect effects – general circulation model intercomparison and evaluation with satellite data

    Directory of Open Access Journals (Sweden)

    M. Schulz

    2009-11-01

    Full Text Available Aerosol indirect effects continue to constitute one of the most important uncertainties for anthropogenic climate perturbations. Within the international AEROCOM initiative, the representation of aerosol-cloud-radiation interactions in ten different general circulation models (GCMs is evaluated using three satellite datasets. The focus is on stratiform liquid water clouds since most GCMs do not include ice nucleation effects, and none of the model explicitly parameterises aerosol effects on convective clouds. We compute statistical relationships between aerosol optical depth (τa and various cloud and radiation quantities in a manner that is consistent between the models and the satellite data. It is found that the model-simulated influence of aerosols on cloud droplet number concentration (Nd compares relatively well to the satellite data at least over the ocean. The relationship between τa and liquid water path is simulated much too strongly by the models. This suggests that the implementation of the second aerosol indirect effect mainly in terms of an autoconversion parameterisation has to be revisited in the GCMs. A positive relationship between total cloud fraction (fcld and τa as found in the satellite data is simulated by the majority of the models, albeit less strongly than that in the satellite data in most of them. In a discussion of the hypotheses proposed in the literature to explain the satellite-derived strong fcld–τa relationship, our results indicate that none can be identified as a unique explanation. Relationships similar to the ones found in satellite data between τa and cloud top temperature or outgoing long-wave radiation (OLR are simulated by only a few GCMs. The GCMs that simulate a negative OLR–τa relationship show a strong positive correlation between

  19. Aerosol indirect effects ? general circulation model intercomparison and evaluation with satellite data

    Energy Technology Data Exchange (ETDEWEB)

    Quaas, Johannes; Ming, Yi; Menon, Surabi; Takemura, Toshihiko; Wang, Minghuai; Penner, Joyce E.; Gettelman, Andrew; Lohmann, Ulrike; Bellouin, Nicolas; Boucher, Olivier; Sayer, Andrew M.; Thomas, Gareth E.; McComiskey, Allison; Feingold, Graham; Hoose, Corinna; Kristansson, Jon Egill; Liu, Xiaohong; Balkanski, Yves; Donner, Leo J.; Ginoux, Paul A.; Stier, Philip; Grandey, Benjamin; Feichter, Johann; Sednev, Igor; Bauer, Susanne E.; Koch, Dorothy; Grainger, Roy G.; Kirkevag, Alf; Iversen, Trond; Seland, Oyvind; Easter, Richard; Ghan, Steven J.; Rasch, Philip J.; Morrison, Hugh; Lamarque, Jean-Francois; Iacono, Michael J.; Kinne, Stefan; Schulz, Michael

    2010-03-12

    Aerosol indirect effects continue to constitute one of the most important uncertainties for anthropogenic climate perturbations. Within the international AEROCOM initiative, the representation of aerosol-cloud-radiation interactions in ten different general circulation models (GCMs) is evaluated using three satellite datasets. The focus is on stratiform liquid water clouds since most GCMs do not include ice nucleation effects, and none of the model explicitly parameterises aerosol effects on convective clouds. We compute statistical relationships between aerosol optical depth ({tau}{sub a}) and various cloud and radiation quantities in a manner that is consistent between the models and the satellite data. It is found that the model-simulated influence of aerosols on cloud droplet number concentration (N{sub d}) compares relatively well to the satellite data at least over the ocean. The relationship between {tau}{sub a} and liquid water path is simulated much too strongly by the models. This suggests that the implementation of the second aerosol indirect effect mainly in terms of an autoconversion parameterisation has to be revisited in the GCMs. A positive relationship between total cloud fraction (f{sub cld}) and {tau}{sub a} as found in the satellite data is simulated by the majority of the models, albeit less strongly than that in the satellite data in most of them. In a discussion of the hypotheses proposed in the literature to explain the satellite-derived strong f{sub cld} - {tau}{sub a} relationship, our results indicate that none can be identified as a unique explanation. Relationships similar to the ones found in satellite data between {tau}{sub a} and cloud top temperature or outgoing long-wave radiation (OLR) are simulated by only a few GCMs. The GCMs that simulate a negative OLR - {tau}{sub a} relationship show a strong positive correlation between {tau}{sub a} and f{sub cld} The short-wave total aerosol radiative forcing as simulated by the GCMs is

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

    Science.gov (United States)

    Kim, Young-Mi; Neff, James Alan

    2010-01-01

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

  1. A New Approach to Calculate Indirect GWPs using the UIUC 2-D CRT and RTM Model

    Science.gov (United States)

    Li, Y.; Youn, D.; Patten, K.; Wuebbles, D.

    2006-12-01

    Global warming potentials (GWPs) are defined to be the total impact over time of adding a unit mass of a greenhouse gas to the atmosphere. Indirect GWPs are due to ozone depletion effects in the stratosphere for a certain compound and therefore stand for the long-term global cooling effects. Previously, indirect GWPs were calculated using a box model, which was not able to consider the complex processes in the atmosphere. As a step towards obtaining indirect GWPs through a more robust approach, the UIUC 2-D CRT model was used as the computational tool to derive ozone changes. The 2-D model has more realistic chemical, physical, and dynamical processes in the atmosphere and a relatively complete transport system, which makes it useful for a more accurate analysis. Furthermore, the University of Illinois at Urbana-Champaign (UIUC) radiative transfer model (RTM) is employed to derive the corresponding time-dependent radiative forcings from the 2-D CRT outputs. Two Halon compounds, Halon-1211 and Halon-1301, were selected to be studied for their indirect GWPs. The results showed that instantaneous and stratospheric adjusted indirect GWPs for a 100-year horizon are -10004.8 and -10237.1 for Halon-1211, while for Halon-1301 they are -19218.0 and -19627.6. The indirect GWPs for Halon-1211 and -1301 presented here are two to three times smaller compared to the results in WMO (2006) draft. Further analysis on indirect GWPs will be carried out using our 3-D MOZART-3 model.

  2. Indirect effect of financial strain on daily cortisol output through daily negative to positive affect index in the Coronary Artery Risk Development in Young Adults Study.

    Science.gov (United States)

    Puterman, Eli; Haritatos, Jana; Adler, Nancy E; Sidney, Steve; Schwartz, Joseph E; Epel, Elissa S

    2013-12-01

    Daily affect is important to health and has been linked to cortisol. The combination of high negative affect and low positive affect may have a bigger impact on increasing HPA axis activity than either positive or negative affect alone. Financial strain may both dampen positive affect as well as increase negative affect, and thus provides an excellent context for understanding the associations between daily affect and cortisol. Using random effects mixed modeling with maximum likelihood estimation, we examined the relationship between self-reported financial strain and estimated mean daily cortisol level (latent cortisol variable), based on six salivary cortisol assessments throughout the day, and whether this relationship was mediated by greater daily negative to positive affect index measured concurrently in a sample of 776 Coronary Artery Risk Development in Young Adults (CARDIA) Study participants. The analysis revealed that while no total direct effect existed for financial strain on cortisol, there was a significant indirect effect of high negative affect to low positive affect, linking financial strain to elevated cortisol. In this sample, the effects of financial strain on cortisol through either positive affect or negative affect alone were not significant. A combined affect index may be a more sensitive and powerful measure than either negative or positive affect alone, tapping the burden of chronic financial strain, and its effects on biology.

  3. New fuzzy approximate model for indirect adaptive control of distributed solar collectors

    KAUST Repository

    Elmetennani, Shahrazed

    2014-06-01

    This paper studies the problem of controlling a parabolic solar collectors, which consists of forcing the outlet oil temperature to track a set reference despite possible environmental disturbances. An approximate model is proposed to simplify the controller design. The presented controller is an indirect adaptive law designed on the fuzzy model with soft-sensing of the solar irradiance intensity. The proposed approximate model allows the achievement of a simple low dimensional set of nonlinear ordinary differential equations that reproduces the dynamical behavior of the system taking into account its infinite dimension. Stability of the closed loop system is ensured by resorting to Lyapunov Control functions for an indirect adaptive controller.

  4. Explicit calculation of indirect global warming potentials for halons using atmospheric models

    Directory of Open Access Journals (Sweden)

    D. J. Wuebbles

    2009-11-01

    Full Text Available The concept of Global Warming Potentials (GWPs has been extensively used in policy consideration as a relative index for comparing the climate impact of an emitted greenhouse gas (GHG, relative to carbon dioxide with equal mass emissions. Ozone depletion due to emission of chlorinated or brominated halocarbons leads to cooling of the climate system in the opposite direction to the direct warming contribution by halocarbons as GHGs. This cooling is a key indirect effect of the halocarbons on climatic radiative forcing, which is accounted for by indirect GWPs. With respect to climate, it is critical to understand net influences considering direct warming and indirect cooling effects especially for Halons due to the greater ozone-depleting efficiency of bromine over chlorine. Until now, the indirect GWPs have been calculated using a parameterized approach based on the concept of Equivalent Effective Stratospheric Chlorine (EESC and the observed ozone depletion over the last few decades. As a step towards obtaining indirect GWPs through a more robust approach, we use atmospheric models to explicitly calculate the indirect GWPs of Halon-1211 and Halon-1301 for a 100-year time horizon. State-of-the-art global chemistry-transport models (CTMs were used as the computational tools to derive more realistic ozone depletion changes caused by an added pulse emission of the two major Halons at the surface. The radiative forcings on climate from the ozone changes have been calculated for indirect GWPs using an atmospheric radiative transfer model (RTM. The simulated temporal variations of global average total column Halons after a pulse perturbation follow an exponential decay with an e-folding time which is consistent with the expected chemical lifetimes of the Halons. Our calculated indirect GWPs for the two Halons are much smaller than those from past studies but are within a single standard deviation of WMO (2007 values and the direct GWP values derived

  5. Direct and indirect signals of natural composite Higgs models

    CERN Document Server

    Niehoff, Christoph; Straub, David M

    2015-01-01

    We present a comprehensive numerical analysis of a four-dimensional model with the Higgs as a composite pseudo-Nambu-Goldstone boson that features a calculable Higgs potential and protective custodial and flavour symmetries to reduce electroweak fine-tuning. We employ a novel numerical technique that allows us for the first time to study constraints from radiative electroweak symmetry breaking, Higgs physics, electroweak precision tests, flavour physics, and direct LHC bounds on fermion and vector boson resonances in a single framework. We consider four different flavour symmetries in the composite sector, one of which we show to not be viable anymore in view of strong precision constraints. In the other cases, all constraints can be passed with a sub-percent electroweak fine-tuning. The models can explain the excesses recently observed in $WW$, $WZ$, $Wh$ and $\\ell^+\\ell^-$ resonance searches by ATLAS and CMS and the anomalies in angular observables and branching ratios of rare semi-leptonic $B$ decays obser...

  6. Childhood onset generalised dystonia can be modelled by increased gain in the indirect basal ganglia pathway.

    Science.gov (United States)

    Sanger, T D

    2003-11-01

    Clinical experience suggests an important role of the indirect basal ganglia pathway in the genesis of childhood onset generalised dystonia, but it has been difficult to reconcile the increased muscle activity in dystonia with the current model of basal ganglia function in which the indirect pathway is considered primarily inhibitory. The aim of this study was to present a modification of the direct-indirect pathway model, in which the indirect pathway is inverting rather than purely inhibitory, so that while high signals are inhibited, low signals are amplified. As the basal ganglia may be a feedback loop that modifies cortical activity, instability from excessive gain in this feedback loop could explain features of dystonia. A detailed mathematical model is provided, together with simulations of cortical cell population spiking behaviour when connected through a basal ganglia loop. The simulations show that increased gain in the indirect pathway relative to the direct pathway can lead to unstable uncontrolled synchronous oscillations in cortex and basal ganglia. This behaviour could result in dystonia. The model provides a consistent explanation for the association of dystonia with parkinsonism and disorders characterised by dopamine depletion, the ability to treat some dystonias with dopamine, the ability of neuroleptic drug treatment to cause an acute dystonic reaction treatable with anticholinergic drugs, and the ability of pallidotomy or deep brain stimulation of the internal pallidum to alleviate symptoms of generalised dystonia.

  7. Developing of New Facets of Indirect Modeling in the Geosciences

    CERN Document Server

    Owladeghaffari, Hamed; Sharifzadeh, Mostafa

    2008-01-01

    In this paper, we describe some applications of Self Organizing feature map Neuro-Fuzzy Inference System (SONFIS) and Self Organizing feature map Rough Set (SORST) in analysis of permeability at a dam site and lost circulation in the drilling of three wells in Iran. Elicitation of the best rules on the information tables, exploration of the dominant structures on the behaviour of systems while they fall in to the balance of the second granulation level (rules) and highlighting of most effective attributes (parameters) on the selected systems, are some of the benefits of the proposed methods. In the other process, using complex networks (graphs) theory - as another method in not 1:1 modelling branch- mechanical behaviour of a rock joint has been investigated. Keywords: Information Granules; SONFIS; SORST; Complex Networks; Permeability; Lost Circulation; Mechanical Behavior of a Rock Joint

  8. Climate impact of biofuels in shipping: global model studies of the aerosol indirect effect.

    Science.gov (United States)

    Righi, Mattia; Klinger, Carolin; Eyring, Veronika; Hendricks, Johannes; Lauer, Axel; Petzold, Andreas

    2011-04-15

    Aerosol emissions from international shipping are recognized to have a large impact on the Earth's radiation budget, directly by scattering and absorbing solar radiation and indirectly by altering cloud properties. New regulations have recently been approved by the International Maritime Organization (IMO) aiming at progressive reductions of the maximum sulfur content allowed in marine fuels from current 4.5% by mass down to 0.5% in 2020, with more restrictive limits already applied in some coastal regions. In this context, we use a global bottom-up algorithm to calculate geographically resolved emission inventories of gaseous (NO(x), CO, SO(2)) and aerosol (black carbon, organic matter, sulfate) species for different kinds of low-sulfur fuels in shipping. We apply these inventories to study the resulting changes in radiative forcing, attributed to particles from shipping, with the global aerosol-climate model EMAC-MADE. The emission factors for the different fuels are based on measurements at a test bed of a large diesel engine. We consider both fossil fuel (marine gas oil) and biofuels (palm and soy bean oil) as a substitute for heavy fuel oil in the current (2006) fleet and compare their climate impact to that resulting from heavy fuel oil use. Our simulations suggest that ship-induced surface level concentrations of sulfate aerosol are strongly reduced, up to about 40-60% in the high-traffic regions. This clearly has positive consequences for pollution reduction in the vicinity of major harbors. Additionally, such reductions in the aerosol loading lead to a decrease of a factor of 3-4 in the indirect global aerosol effect induced by emissions from international shipping.

  9. On the characteristics of aerosol indirect effect based on dynamic regimes in global climate models

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, S.; Wang, Minghuai; Ghan, Steven J.; Ding, A.; Wang, Hailong; Zhang, Kai; Neubauer, David; Lohmann, U.; Ferrachat, S.; Takeamura, Toshihiko; Gettelman, A.; Morrison, H.; Lee, Y. H.; Shindell, D. T.; Partridge, Daniel; Stier, P.; Kipling, Z.; Fu, Congbin

    2016-03-04

    Aerosol-cloud interactions continue to constitute a major source of uncertainty for the estimate of climate radiative forcing. The variation of aerosol indirect effects (AIE) in climate models is investigated across different dynamical regimes, determined by monthly mean 500 hPa vertical pressure velocity (ω500), lower-tropospheric stability (LTS) and large-scale surface precipitation rate derived from several global climate models (GCMs), with a focus on liquid water path (LWP) response to cloud condensation nuclei (CCN) concentrations. The LWP sensitivity to aerosol perturbation within dynamic regimes is found to exhibit a large spread among these GCMs. It is in regimes of strong large-scale ascend (ω500 < -25 hPa/d) and low clouds (stratocumulus and trade wind cumulus) where the models differ most. Shortwave aerosol indirect forcing is also found to differ significantly among different regimes. Shortwave aerosol indirect forcing in ascending regimes is as large as that in stratocumulus regimes, which indicates that regimes with strong large-scale ascend are as important as stratocumulus regimes in studying AIE. 42" It is further shown that shortwave aerosol indirect forcing over regions with high monthly large-scale surface precipitation rate (> 0.1 mm/d) contributes the most to the total aerosol indirect forcing (from 64% to nearly 100%). Results show that the uncertainty in AIE is even larger within specific dynamical regimes than that globally, pointing to the need to reduce the uncertainty in AIE in different dynamical regimes.

  10. Geographic and taxonomic distribution of a positive interaction: ant-tended homopterans indirectly benefit figs across southern Africa.

    Science.gov (United States)

    Cushman, J Hall; Compton, Stephen G; Zachariades, Costas; Ware, Anthony B; Nefdt, Rory J C; Rashbrook, Vanessa K

    1998-09-01

    Although species pairs and assemblages often occur across geographic regions, ecologists know very little about the outcome of their interactions on such large spatial scales. Here, we assess the geographic distribution and taxonomic diversity of a positive interaction involving ant-tended homopterans and fig trees in the genus Ficus. Previous experimental studies at a few locations in South Africa indicated that Ficus sur indirectly benefited from the presence of a homopteran (Hilda patruelis) because it attracted ants (primarily Pheidole megacephala) that reduced the effects of both pre-dispersal ovule gallers and parasitoids of pollinating wasps. Based on this work, we evaluated three conditions that must be met in order to support the hypothesis that this indirect interaction involves many fig species and occurs throughout much of southern Africa and Madagascar. Data on 429 trees distributed among five countries indicated that 20 of 38 Ficus species, and 46% of all trees sampled, had ants on their figs. Members of the Sycomorus subgenus were significantly more likely to attract ants than those in the Urostigma subgenus, and ant-colonization levels on these species were significantly greater than for Urostigma species. On average, each ant-occupied F.sur tree had 37% of its fig crop colonized by ants, whereas the value was 24% for other Ficus species. H. patruelis was the most common source for attracting ants, although figs were also attacked by a range of other ant-tended homopterans. P. megacephala was significantly more common on figs than other ant species, being present on 58% of sampled trees. Ant densities commonly exceeded 4.5 per fig, which a field experiment indicated was sufficient to provide protection from ovule gallers and parasitoids of pollinators. Forty-nine percent of all colonized F. sur trees sampled had ant densities equal to or greater than 4.5 per fig, whereas this value was 23% for other Ficus species. We conclude that there is

  11. The quantitative genetics of indirect genetic effects: a selective review of modelling issues : Review

    NARCIS (Netherlands)

    Bijma, P.

    2014-01-01

    Indirect genetic effects (IGE) occur when the genotype of an individual affects the phenotypic trait value of another conspecific individual. IGEs can have profound effects on both the magnitude and the direction of response to selection. Models of inheritance and response to selection in traits sub

  12. Global modelling of direct and indirect effects of sea spray aerosol using a source function encapsulating wave state

    Science.gov (United States)

    Partanen, A.-I.; Dunne, E. M.; Bergman, T.; Laakso, A.; Kokkola, H.; Ovadnevaite, J.; Sogacheva, L.; Baisnée, D.; Sciare, J.; Manders, A.; O'Dowd, C.; de Leeuw, G.; Korhonen, H.

    2014-11-01

    Recently developed parameterizations for the sea spray aerosol source flux, encapsulating wave state, and its organic fraction were incorporated into the aerosol-climate model ECHAM-HAMMOZ to investigate the direct and indirect radiative effects of sea spray aerosol particles. Our simulated global sea salt emission of 805 Tg yr-1 (uncertainty range 378-1233 Tg yr-1) was much lower than typically found in previous studies. Modelled sea salt and sodium ion concentrations agreed relatively well with measurements in the smaller size ranges at Mace Head (annual normalized mean model bias -13% for particles with vacuum aerodynamic diameter Dva particles with aerodynamic diameter Da particles with Da particles with 2.5 μm biologically active months, suggesting a need to improve the parameterization of the organic sea spray fraction. Globally, the satellite-retrieved AOD over the oceans, using PARASOL data, was underestimated by the model (means over ocean 0.16 and 0.10, respectively); however, in the pristine region around Amsterdam Island the measured AOD fell well within the simulated uncertainty range. The simulated sea spray aerosol contribution to the indirect radiative effect was positive (0.3 W m-2), in contrast to previous studies. This positive effect was ascribed to the tendency of sea salt aerosol to suppress both the in-cloud supersaturation and the formation of cloud condensation nuclei from sulfate. These effects can be accounted for only in models with sufficiently detailed aerosol microphysics and physics-based parameterizations of cloud activation. However, due to a strong negative direct effect, the simulated effective radiative forcing (total radiative) effect was -0.2 W m-2. The simulated radiative effects of the primary marine organic emissions were small, with a direct effect of 0.03 W m-2 and an indirect effect of -0.07 W m-2.

  13. On the characteristics of aerosol indirect effect based on dynamic regimes in global climate models

    OpenAIRE

    2015-01-01

    Aerosol-cloud interactions continue to constitute a major source of uncertainty for the estimate of climate radiative forcing. The variation of aerosol indirect effects (AIE) in climate models is investigated across different dynamical regimes, determined by monthly mean 500 hPa vertical pressure velocity (ω500), lower-tropospheric stability (LTS) and large-scale surface precipitation rate derived from several global climate models (GCMs), with a focus on liquid water ...

  14. Assessing the economic impact of indirect liquefaction process improvements: Volume 1, Development of the integrated indirect liquefaction model and baseline case

    Energy Technology Data Exchange (ETDEWEB)

    Gray, D.; Tomlinson, G.C. (Mitre Corp., McLean, VA (USA). Civil Systems Div.)

    1990-10-01

    This report documents the development of an integrated indirect liquefaction system model, which processes input coal to refined liquid products, and the model's application in the analysis of a baseline case. The baseline case uses Shell gasification of coal followed by gas cleaning to produce a clean synthesis gas for slurry-phase Fischer-Tropsch synthesis. The raw liquid products are refined to produce gasoline and diesel. Costs of liquid products have been estimated for the baseline plant. The model also alloys many sensitivity studies to be performed so that the economic impacts of research and development advances can be quantified. When used in this manner, the model can provide research guidance for future indirect liquefaction studies. 18 refs., 12 figs., 12 tabs.

  15. Model-Independent Indirect Detection Constraints on Hidden Sector Dark Matter

    CERN Document Server

    Elor, Gilly; Slatyer, Tracy R; Xue, Wei

    2015-01-01

    If dark matter inhabits an expanded "hidden sector", annihilations may proceed through sequential decays or multi-body final states. We map out the potential signals and current constraints on such a framework in indirect searches, using a model-independent setup based on multi-step hierarchical cascade decays. While remaining agnostic to the details of the hidden sector model, our framework captures the generic broadening of the spectrum of secondary particles (photons, neutrinos, e+e- and antiprotons) relative to the case of direct annihilation to Standard Model particles. We explore how indirect constraints on dark matter annihilation limit the parameter space for such cascade/multi-particle decays. We investigate limits from the cosmic microwave background by Planck, the Fermi measurement of photons from the dwarf galaxies, and positron data from AMS-02. The presence of a hidden sector can change the constraints on the dark matter annihilation cross section by up to an order of magnitude in either directi...

  16. Modeling of a regenerative indirect evaporative cooler for a desiccant cooling system

    DEFF Research Database (Denmark)

    Bellemo, Lorenzo; Elmegaard, Brian; Reinholdt, Lars O.;

    This paper presents a numerical study of a regenerative indirect evaporative cooler, the so-called Dew Point Cooler (DPC), which is part of a Desiccant Cooling system that may both dehumidify and cool humid air. The DPC model is based on first principles using a 1D finite volume scheme and determ......This paper presents a numerical study of a regenerative indirect evaporative cooler, the so-called Dew Point Cooler (DPC), which is part of a Desiccant Cooling system that may both dehumidify and cool humid air. The DPC model is based on first principles using a 1D finite volume scheme...... and determines the steady state working conditions for the component. A sensitivity analysis of the DPC performance is carried out based on the air inlet conditions, air flow rate and recirculation fraction. A recirculation fraction around 0.3 maximizes the DPC net cooling capacity. The supply temperature...

  17. Numerical modelling of a stoker furnace operated under indirect co-firing of biomass

    Directory of Open Access Journals (Sweden)

    Litka Rafał

    2016-06-01

    Full Text Available The subject of the CFD analysis presented in this paper is the process of biomass indirect co-firing carried out in a system composed of a stoker-fired furnace coupled with a gasification reactor. The installation is characterised by its compact structure, which makes it possible to minimise heat losses to the environment and enhance the physical enthalpy of the oxidising agent – flue gases – having a favourable chemical composition with oxygen and water vapour. The test results provided tools for modelling of biomass thermal processing using a non-standard oxidiser in the form of flue gases. The obtained models were used to optimise the indirect co-combustion process to reduce emissions. An overall effect of co-combustion of gas from biomass gasification in the stoker furnace is the substantial reduction in NO emissions by about 22%.

  18. Evolutionary stability and resistance to cheating in an indirect reciprocity model based on reputation

    CERN Document Server

    Martinez-Vaquero, Luis A

    2013-01-01

    Indirect reciprocity is one of the main mechanisms to explain the emergence and sustainment of altruism in societies. The standard approach to indirect reciprocity are reputation models. These are games in which players base their decisions on their opponent's reputation gained in past interactions with other players (moral assessment). The combination of actions and moral assessment leads to a large diversity of strategies, thus determining the stability of any of them against invasions by all the others is a difficult task. We use a variant of a previously introduced reputation-based model that let us systematically analyze all these invasions and determine which ones are successful. Accordingly we are able to identify the third-order strategies (those which, apart from the action, judge considering both the reputation of the donor and that of the recipient) that are evolutionarily stable. Our results reveal that if a strategy resists the invasion of any other one sharing its same moral assessment, it can r...

  19. Aerosol Indirect Effects on Cirrus Clouds in Global Aerosol-Climate Models

    Science.gov (United States)

    Liu, X.; Zhang, K.; Wang, Y.; Neubauer, D.; Lohmann, U.; Ferrachat, S.; Zhou, C.; Penner, J.; Barahona, D.; Shi, X.

    2015-12-01

    Cirrus clouds play an important role in regulating the Earth's radiative budget and water vapor distribution in the upper troposphere. Aerosols can act as solution droplets or ice nuclei that promote ice nucleation in cirrus clouds. Anthropogenic emissions from fossil fuel and biomass burning activities have substantially perturbed and enhanced concentrations of aerosol particles in the atmosphere. Global aerosol-climate models (GCMs) have now been used to quantify the radiative forcing and effects of aerosols on cirrus clouds (IPCC AR5). However, the estimate uncertainty is very large due to the different representation of ice cloud formation and evolution processes in GCMs. In addition, large discrepancies have been found between model simulations in terms of the spatial distribution of ice-nucleating aerosols, relative humidity, and temperature fluctuations, which contribute to different estimates of the aerosol indirect effect through cirrus clouds. In this presentation, four GCMs with the start-of-the art representations of cloud microphysics and aerosol-cloud interactions are used to estimate the aerosol indirect effects on cirrus clouds and to identify the causes of the discrepancies. The estimated global and annual mean anthropogenic aerosol indirect effect through cirrus clouds ranges from 0.1 W m-2 to 0.3 W m-2 in terms of the top-of-the-atmosphere (TOA) net radiation flux, and 0.5-0.6 W m-2 for the TOA longwave flux. Despite the good agreement on global mean, large discrepancies are found at the regional scale. The physics behind the aerosol indirect effect is dramatically different. Our analysis suggests that burden of ice-nucleating aerosols in the upper troposphere, ice nucleation frequency, and relative role of ice formation processes (i.e., homogeneous versus heterogeneous nucleation) play key roles in determining the characteristics of the simulated aerosol indirect effects. In addition to the indirect effect estimate, we also use field campaign

  20. Assessment and indirect adjustment for confounding by smoking in cohort studies using relative hazards models.

    Science.gov (United States)

    Richardson, David B; Laurier, Dominique; Schubauer-Berigan, Mary K; Tchetgen Tchetgen, Eric; Cole, Stephen R

    2014-11-01

    Workers' smoking histories are not measured in many occupational cohort studies. Here we discuss the use of negative control outcomes to detect and adjust for confounding in analyses that lack information on smoking. We clarify the assumptions necessary to detect confounding by smoking and the additional assumptions necessary to indirectly adjust for such bias. We illustrate these methods using data from 2 studies of radiation and lung cancer: the Colorado Plateau cohort study (1950-2005) of underground uranium miners (in which smoking was measured) and a French cohort study (1950-2004) of nuclear industry workers (in which smoking was unmeasured). A cause-specific relative hazards model is proposed for estimation of indirectly adjusted associations. Among the miners, the proposed method suggests no confounding by smoking of the association between radon and lung cancer--a conclusion supported by adjustment for measured smoking. Among the nuclear workers, the proposed method suggests substantial confounding by smoking of the association between radiation and lung cancer. Indirect adjustment for confounding by smoking resulted in an 18% decrease in the adjusted estimated hazard ratio, yet this cannot be verified because smoking was unmeasured. Assumptions underlying this method are described, and a cause-specific proportional hazards model that allows easy implementation using standard software is presented.

  1. Integrated Direct and Indirect Flood Risk Modeling: Development and Sensitivity Analysis.

    Science.gov (United States)

    Koks, E E; Bočkarjova, M; de Moel, H; Aerts, J C J H

    2015-05-01

    In this article, we propose an integrated direct and indirect flood risk model for small- and large-scale flood events, allowing for dynamic modeling of total economic losses from a flood event to a full economic recovery. A novel approach is taken that translates direct losses of both capital and labor into production losses using the Cobb-Douglas production function, aiming at improved consistency in loss accounting. The recovery of the economy is modeled using a hybrid input-output model and applied to the port region of Rotterdam, using six different flood events (1/10 up to 1/10,000). This procedure allows gaining a better insight regarding the consequences of both high- and low-probability floods. The results show that in terms of expected annual damage, direct losses remain more substantial relative to the indirect losses (approximately 50% larger), but for low-probability events the indirect losses outweigh the direct losses. Furthermore, we explored parameter uncertainty using a global sensitivity analysis, and varied critical assumptions in the modeling framework related to, among others, flood duration and labor recovery, using a scenario approach. Our findings have two important implications for disaster modelers and practitioners. First, high-probability events are qualitatively different from low-probability events in terms of the scale of damages and full recovery period. Second, there are substantial differences in parameter influence between high-probability and low-probability flood modeling. These findings suggest that a detailed approach is required when assessing the flood risk for a specific region. © 2014 Society for Risk Analysis.

  2. An Indirect Simulation-Optimization Model for Determining Optimal TMDL Allocation under Uncertainty

    Directory of Open Access Journals (Sweden)

    Feng Zhou

    2015-11-01

    Full Text Available An indirect simulation-optimization model framework with enhanced computational efficiency and risk-based decision-making capability was developed to determine optimal total maximum daily load (TMDL allocation under uncertainty. To convert the traditional direct simulation-optimization model into our indirect equivalent model framework, we proposed a two-step strategy: (1 application of interval regression equations derived by a Bayesian recursive regression tree (BRRT v2 algorithm, which approximates the original hydrodynamic and water-quality simulation models and accurately quantifies the inherent nonlinear relationship between nutrient load reductions and the credible interval of algal biomass with a given confidence interval; and (2 incorporation of the calibrated interval regression equations into an uncertain optimization framework, which is further converted to our indirect equivalent framework by the enhanced-interval linear programming (EILP method and provides approximate-optimal solutions at various risk levels. The proposed strategy was applied to the Swift Creek Reservoir’s nutrient TMDL allocation (Chesterfield County, VA to identify the minimum nutrient load allocations required from eight sub-watersheds to ensure compliance with user-specified chlorophyll criteria. Our results indicated that the BRRT-EILP model could identify critical sub-watersheds faster than the traditional one and requires lower reduction of nutrient loadings compared to traditional stochastic simulation and trial-and-error (TAE approaches. This suggests that our proposed framework performs better in optimal TMDL development compared to the traditional simulation-optimization models and provides extreme and non-extreme tradeoff analysis under uncertainty for risk-based decision making.

  3. Indirect constraints on the Georgi-Machacek model and implications for Higgs couplings

    CERN Document Server

    Hartling, Katy; Logan, Heather E

    2014-01-01

    We update the indirect constraints on the Georgi-Machacek model from $B$-physics and electroweak precision observables, including new constraints from $b \\to s \\gamma$ and $B^0_s \\to \\mu^+ \\mu^-$. We illustrate the effect of these constraints on the couplings of the Standard Model-like Higgs boson by performing scans using the most general scalar potential, subject to vacuum stability and perturbativity constraints. We find that simultaneous enhancements of all the Higgs production cross sections by up to 39\\% are still allowed after imposing these constraints. LHC rate measurements on the Higgs pole could be blind to these enhancements if unobserved non-standard Higgs decays are present.

  4. Indirect detection constraints on the model space of dark matter effective theories

    Science.gov (United States)

    Carpenter, Linda M.; Colburn, Russell; Goodman, Jessica

    2015-11-01

    Using limits on photon flux from dwarf spheroidal galaxies, we place bounds on the parameter space of models in which dark matter annihilates into multiple final state particle pair channels. We derive constraints on effective operator models with dark matter couplings to third generation fermions and to pairs of standard model vector bosons. We present limits in various slices of model parameter space along with estimations of the region of maximal validity of the effective operator approach for indirect detection. We visualize our bounds for models with multiple final state annihilations by projecting parameter space constraints onto triangles, a technique familiar from collider physics; and we compare our bounds to collider limits on equivalent models.

  5. Indirect Detection Constraints on the Model Space of Dark Matter Effective Theories

    CERN Document Server

    Carpenter, Linda M; Goodman, Jessica

    2015-01-01

    Using limits on photon flux from Dwarf Spheroidal galaxies, we place bounds on the parameter space of models in which Dark Matter annihilates into multiple final state particle pair channels. We derive constraints on effective operator models with Dark Matter couplings to third generation fermions and to pairs of Standard Model vector bosons. We present limits in various slices of model parameter space along with estimations of the region of maximal validity of the effective operator approach for indirect detection. We visualize our bounds for models with multiple final state annihilations by projecting parameter space constraints onto triangles, a technique familiar from collider physics; and we compare our bounds to collider limits on equivalent models.

  6. Indirect Impact of Hedonic Consumption and Emotions on Impulse Purchase Behavior: A Double Mediation Model

    Directory of Open Access Journals (Sweden)

    Mirza A. Haq

    2016-09-01

    Full Text Available Impulse purchasing is a universal yet seldom discussed phenomenon. This research study was oriented with the objective to identify the double-mediated relationship between impulse purchasing behavior and fashion orientation through hedonic consumption and emotions. To achieve this objective, survey research method was deployed and data had been collected from 231 general fashion consumers of Karachi. Process macro developed by Hayes (2012 was used as a statistical tool in order to study the relationship between the studied variable. The results suggest that hedonic consumption and positive emotions fully mediates the relationship between fashion orientation and impulse purchasing. The implications portrayed that there is a significant positive indirect effect of fashion orientation on impulse purchasing behavior through hedonic consumption and emotions collectively.

  7. MODELS TO ESTIMATE BRAZILIAN INDIRECT TENSILE STRENGTH OF LIMESTONE IN SATURATED STATE

    Directory of Open Access Journals (Sweden)

    Zlatko Briševac

    2016-06-01

    Full Text Available There are a number of methods of estimating physical and mechanical characteristics. Principally, the most widely used is the regression, but recently the more sophisticated methods such as neural networks has frequently been applied, as well. This paper presents the models of a simple and a multiple regression and the neural networks – types Radial Basis Function and Multiple Layer Perceptron, which can be used for the estimate of the Brazilian indirect tensile strength in saturated conditions. The paper includes the issues of collecting the data for the analysis and modelling and the overview of the performed analysis of the efficacy assessment of the estimate of each model. After the assessment, the model which provides the best estimate was selected, including the model which could have the most wide-spread application in the engineering practice.

  8. Seven challenges for modelling indirect transmission: Vector-borne diseases, macroparasites and neglected tropical diseases

    Directory of Open Access Journals (Sweden)

    T. Déirdre Hollingsworth

    2015-03-01

    Full Text Available Many of the challenges which face modellers of directly transmitted pathogens also arise when modelling the epidemiology of pathogens with indirect transmission – whether through environmental stages, vectors, intermediate hosts or multiple hosts. In particular, understanding the roles of different hosts, how to measure contact and infection patterns, heterogeneities in contact rates, and the dynamics close to elimination are all relevant challenges, regardless of the mode of transmission. However, there remain a number of challenges that are specific and unique to modelling vector-borne diseases and macroparasites. Moreover, many of the neglected tropical diseases which are currently targeted for control and elimination are vector-borne, macroparasitic, or both, and so this article includes challenges which will assist in accelerating the control of these high-burden diseases. Here, we discuss the challenges of indirect measures of infection in humans, whether through vectors or transmission life stages and in estimating the contribution of different host groups to transmission. We also discuss the issues of “evolution-proof” interventions against vector-borne disease.

  9. Model-independent indirect detection constraints on hidden sector dark matter

    Science.gov (United States)

    Elor, Gilly; Rodd, Nicholas L.; Slatyer, Tracy R.; Xue, Wei

    2016-06-01

    If dark matter inhabits an expanded ``hidden sector'', annihilations may proceed through sequential decays or multi-body final states. We map out the potential signals and current constraints on such a framework in indirect searches, using a model-independent setup based on multi-step hierarchical cascade decays. While remaining agnostic to the details of the hidden sector model, our framework captures the generic broadening of the spectrum of secondary particles (photons, neutrinos, e+e- and bar p p) relative to the case of direct annihilation to Standard Model particles. We explore how indirect constraints on dark matter annihilation limit the parameter space for such cascade/multi-particle decays. We investigate limits from the cosmic microwave background by Planck, the Fermi measurement of photons from the dwarf galaxies, and positron data from AMS-02. The presence of a hidden sector can change the constraints on the dark matter by up to an order of magnitude in either direction (although the effect can be much smaller). We find that generally the bound from the Fermi dwarfs is most constraining for annihilations to photon-rich final states, while AMS-02 is most constraining for electron and muon final states; however in certain instances the CMB bounds overtake both, due to their approximate independence on the details of the hidden sector cascade. We provide the full set of cascade spectra considered here as publicly available code with examples at http://web.mit.edu/lns/research/CascadeSpectra.html.

  10. Latent variable indirect response modeling of categorical endpoints representing change from baseline.

    Science.gov (United States)

    Hu, Chuanpu; Xu, Zhenhua; Mendelsohn, Alan M; Zhou, Honghui

    2013-02-01

    Accurate exposure-response modeling is important in drug development. Methods are still evolving in the use of mechanistic, e.g., indirect response (IDR) models to relate discrete endpoints, mostly of the ordered categorical form, to placebo/co-medication effect and drug exposure. When the discrete endpoint is derived using change-from-baseline measurements, a mechanistic exposure-response modeling approach requires adjustment to maintain appropriate interpretation. This manuscript describes a new modeling method that integrates a latent-variable representation of IDR models with standard logistic regression. The new method also extends to general link functions that cover probit regression or continuous clinical endpoint modeling. Compared to an earlier latent variable approach that constrained the baseline probability of response to be 0, placebo effect parameters in the new model formulation are more readily interpretable and can be separately estimated from placebo data, thus allowing convenient and robust model estimation. A general inherent connection of some latent variable representations with baseline-normalized standard IDR models is derived. For describing clinical response endpoints, Type I and Type III IDR models are shown to be equivalent, therefore there are only three identifiable IDR models. This approach was applied to data from two phase III clinical trials of intravenously administered golimumab for the treatment of rheumatoid arthritis, where 20, 50, and 70% improvement in the American College of Rheumatology disease severity criteria were used as efficacy endpoints. Likelihood profiling and visual predictive checks showed reasonable parameter estimation precision and model performance.

  11. A Framework for Modelling Indirect Land Use Changes in Life Cycle Assessment

    DEFF Research Database (Denmark)

    Schmidt, Jannick Højrup; Weidema, Bo Pedersen; Brandão, Miguel

    2015-01-01

    is generally weakly established. This paper presents the conceptual framework required for a consistent modelling of iLUC in Life Cycle Assessment. It reports on a novel and biophysical iLUC model, in which amortisation is avoided by using discounted Global Warming Potentials (GWPs). The causal link between......Around 9% of global CO2 emissions originate from land use changes. Often, these emissions are not appropriately addressed in Life Cycle Assessment. The link between demand for crops in one region and impacts in other regions is referred to here as indirect land use change (iLUC) and includes...... deforestation, intensification and reduced consumption. Existing models for iLUC tend to ignore intensification and reduced consumption, they most often operate with arbitrary amortisation periods to allocate deforestation emissions over time, and the causal link between land occupation and deforestation...

  12. Mathematical model of an indirect action fuel flow controller for aircraft jet engines

    Science.gov (United States)

    Tudosie, Alexandru-Nicolae

    2017-06-01

    The paper deals with a fuel mass flow rate controller with indirect action for aircraft jet engines. The author has identified fuel controller's main parts and its operation mode, then, based on these observations, one has determined motion equations of each main part, which have built system's non-linear mathematical model. In order to realize a better study this model was linearised (using the finite differences method) and then adimensionalized. Based on this new form of the mathematical model, after applying Laplace transformation, the embedded system (controller+engine) was described by the block diagram with transfer functions. Some Simulink-Matlab simulations were performed, concerning system's time behavior for step input, which lead to some useful conclusions and extension possibilities.

  13. Indirect Energy Flows in Niche Model Food Webs: Effects of Size and Connectance.

    Directory of Open Access Journals (Sweden)

    Jane Shevtsov

    Full Text Available Indirect interactions between species have long been of interest to ecologists. One such interaction type takes place when energy or materials flow via one or more intermediate species between two species with a direct predator-prey relationship. Previous work has shown that, although each such flow is small, their great number makes them important in ecosystems. A new network analysis method, dynamic environ approximation, was used to quantify the fraction of energy flowing from prey to predator over paths of length greater than 1 (flow indirectness or FI in a commonly studied food web model. Web structure was created using the niche model and dynamics followed the Yodzis-Innes model. The effect of food web size (10 to 40 species and connectance (0.1 to 0.48 on FI was examined. For each of 250 model realizations run for each pair of size and connectance values, the FI of every predator-prey interaction in the model was computed and then averaged over the whole network. A classification and regression tree (CART analysis was then used to find the best predictors of FI. The mean FI of the model food webs is 0.092, with a standard deviation of 0.0279. It tends to increase with system size but peaks at intermediate connectance levels. Of 27 potential predictor variables, only five (mean path length, dominant eigenvalue of the adjacency matrix, connectance, mean trophic level and fraction of species belonging to intermediate trophic levels were selected by the CART algorithm as best accounting for variation in the data; mean path length and the dominant eigenvalue of the adjacency matrix were dominant.

  14. Modelling sea salt aerosol and its direct and indirect effects on climate

    Directory of Open Access Journals (Sweden)

    X. Ma

    2007-10-01

    Full Text Available A size-dependent sea salt aerosol parameterization was developed based on the piecewise log-normal approximation (PLA for aerosol size distributions. Results of this parameterization from simulations with a global climate model produce good agreement with observations at the surface and for vertically-integrated volume size distributions. The global and annual mean of the sea salt burden is 10.1 mg m−2. The direct radiative forcing is calculated to be −1.52 and −0.60 W m−2 for clear sky and all sky, respectively. The first indirect radiative forcing is about twice as large as the direct forcing for all-sky (−1.34 W m−2. The results also show that the total indirect forcing of sea salt is −2.9 W m−2 if climatic feedbacks are taken into account. The sensitivity of the forcings to changes in the burdens and sizes of sea salt particles was also investigated based on additional simulations with a different sea salt source function.

  15. Degenerate RFID Channel Modeling for Positioning Applications

    Directory of Open Access Journals (Sweden)

    A. Povalac

    2012-12-01

    Full Text Available This paper introduces the theory of channel modeling for positioning applications in UHF RFID. It explains basic parameters for channel characterization from both the narrowband and wideband point of view. More details are given about ranging and direction finding. Finally, several positioning scenarios are analyzed with developed channel models. All the described models use a degenerate channel, i.e. combined signal propagation from the transmitter to the tag and from the tag to the receiver.

  16. Model-independent indirect detection constraints on hidden sector dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Elor, Gilly; Rodd, Nicholas L.; Slatyer, Tracy R.; Xue, Wei [Center for Theoretical Physics, Massachusetts Institute of Technology,77 Massachusetts Ave, Cambridge, MA 02139 (United States)

    2016-06-10

    If dark matter inhabits an expanded “hidden sector”, annihilations may proceed through sequential decays or multi-body final states. We map out the potential signals and current constraints on such a framework in indirect searches, using a model-independent setup based on multi-step hierarchical cascade decays. While remaining agnostic to the details of the hidden sector model, our framework captures the generic broadening of the spectrum of secondary particles (photons, neutrinos, e{sup +}e{sup −} and p-barp) relative to the case of direct annihilation to Standard Model particles. We explore how indirect constraints on dark matter annihilation limit the parameter space for such cascade/multi-particle decays. We investigate limits from the cosmic microwave background by Planck, the Fermi measurement of photons from the dwarf galaxies, and positron data from AMS-02. The presence of a hidden sector can change the constraints on the dark matter by up to an order of magnitude in either direction (although the effect can be much smaller). We find that generally the bound from the Fermi dwarfs is most constraining for annihilations to photon-rich final states, while AMS-02 is most constraining for electron and muon final states; however in certain instances the CMB bounds overtake both, due to their approximate independence on the details of the hidden sector cascade. We provide the full set of cascade spectra considered here as publicly available code with examples at http://web.mit.edu/lns/research/CascadeSpectra.html.

  17. Daily sleep quality affects drug craving, partially through indirect associations with positive affect, in patients in treatment for nonmedical use of prescription drugs.

    Science.gov (United States)

    Lydon-Staley, David M; Cleveland, H Harrington; Huhn, Andrew S; Cleveland, Michael J; Harris, Jonathan; Stankoski, Dean; Deneke, Erin; Meyer, Roger E; Bunce, Scott C

    2017-02-01

    Sleep disturbance has been identified as a risk factor for relapse in addiction to a range of substances. The relationship between sleep quality and treatment outcome has received relatively little attention in research on nonmedical use of prescription drugs (NMUPD). This study examined the within-person association between sleep quality and craving in medically detoxified patients in residence for the treatment of NMUPD. Participants (n=68) provided daily reports of their sleep quality, negative affect (NA), positive affect (PA), and craving for an average of 9.36 (SD=2.99) days. Within-person associations of sleep quality and craving were examined using multilevel modeling. Within-person mediation analyses were used to evaluate the mediating roles of NA and PA in the relationship between sleep quality and craving. Greater cravings were observed on days of lower than usual sleep quality (γ10=-0.10, p=0.003). Thirty-one percent of the overall association between sleep quality and craving was explained by PA, such that poorer sleep quality was associated with lower PA and, in turn, lower PA was associated with greater craving. No evidence emerged for an indirect association between sleep quality and craving through NA. Daily fluctuations in sleep quality were associated with fluctuations in craving, an association partially explained by the association between sleep quality and daily PA. These data encourage further research on the relationship between sleep, affect, and craving in NMUPD patients, as well as in patients with other substance use disorders. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. A Model for Positively Correlated Count Variables

    DEFF Research Database (Denmark)

    Møller, Jesper; Rubak, Ege Holger

    2010-01-01

    An α-permanental random field is briefly speaking a model for a collection of non-negative integer valued random variables with positive associations. Though such models possess many appealing probabilistic properties, many statisticians seem unaware of α-permanental random fields and their poten......An α-permanental random field is briefly speaking a model for a collection of non-negative integer valued random variables with positive associations. Though such models possess many appealing probabilistic properties, many statisticians seem unaware of α-permanental random fields...

  19. Asymptotic and resampling strategies for assessing and comparing indirect effects in multiple mediator models

    National Research Council Canada - National Science Library

    Preacher, Kristopher J; Hayes, Andrew F

    2008-01-01

    Hypotheses involving mediation are common in the behavioral sciences. Mediation exists when a predictor affects a dependent variable indirectly through at least one intervening variable, or mediator...

  20. Searching for beyond the Standard Model physics using direct and indirect methods at LHCb

    CERN Document Server

    Hall, Samuel C P

    It is known that the Standard Model of particle physics is incomplete in its description of nature at a fundamental level. For example, the Standard Model can neither incorporate dark matter nor explain the matter dominated nature of the Universe. This thesis presents three analyses undertaken using data collected by the LHCb detector. Each analysis searches for indications of physics beyond the Standard Model in dierent decays of B mesons, using dierent techniques. Notably, two analyses look for indications of new physics using indirect methods, and one uses a direct approach. The rst analysis shows evidence for the rare decay BÑ D s with greater than 3 signicance; this also constitutes the rst evidence for a fullyhadronic annihilation-type decay of a B meson. A measurement of the branching fraction of the decay BÑ D s is seen to be higher than, but still compatible with, Standard Model predictions. The CP-asymmetry of the decay is also measured, and its value is precisely in line wi...

  1. Modeling the effect of direct and indirect contamination of on-farm bulk tank milk with Mycobacterium avium subsp. paratuberculosis

    DEFF Research Database (Denmark)

    Okura, Hisako; Nielsen, Søren Saxmose; Toft, Nils

    2013-01-01

    Mycobacterium avium subsp. paratuberculosis (MAP) in milk of bovine origin is suspected of being implicated in Crohn's disease in humans. Milk can be contaminated via direct excretion of MAP in milk or indirectly via fecal contamination of the milk. This study aimed at estimating the level of MAP...... milk from test positive cows would result in discarding 11% of milk and reduce the MAP level by 80%. Due to poor sensitivity of the diagnostic test, removing test-positive cows would not further reduce the already low concentration of MAP and it would not guarantee the milk as MAP-free. The model...

  2. A quantification of predation rates, indirect positive effects on plants, and foraging variation of the giant tropical ant, Paraponera clavata

    Directory of Open Access Journals (Sweden)

    Lee A. Dyer

    2002-09-01

    Full Text Available While a clear consensus is emerging that predators can play a major role in shaping terrestrial communities, basic natural history observations and simple quantifications of predation rates in complex terrestrial systems are lacking. The potential indirect effect of a large predatory ant, Paraponera clavata Fabricius (Formicidae: Ponerinae, on herbivores was determined on rainforest trees at La Selva Biological Station in Costa Rica and Barro Colorado Island in Panama. Prey and other food brought back to nests by 75 colonies of P. clavata were quantified, taking into account temporal, seasonal, and microhabitat variation for both foraging activity and composition of foraging booty. The dispersion and density of ant colonies and combined density with the mean amounts of prey retrieval were used to calculate rates of predation per hectare in the two forests. In addition, herbivory was measured on trees containing P. clavata and on trees where the ants were not foraging. Colonies at La Selva brought back significantly more nectar plus prey than those at Barro Colorado Island, but foraging patterns were similar in the two forests. At both forests, the ants were more active at night, and there was no significant seasonal or colonial variation in consumption of nectar, composition of foraging booty, and overall activity of the colonies. At La Selva, trees containing P. clavata colonies had the same levels of folivory as nearest neighbor trees without P. clavata but had significantly lower folivory than randomly selected trees. Predation by this ant was high in both forests, despite its omnivorous diet. This insect predator is part of potentially important top-down controls in these wet and moist forests.

  3. Indirect MR arthrography of anterior shoulder instability in the ABER and the apprehension test positions: a prospective comparative study of two different shoulder positions during MRI using intravenous gadodiamide contrast for enhancement of the joint fluid

    Energy Technology Data Exchange (ETDEWEB)

    Wintzell, G.; Larsson, S. [Uppsala University Hospital (Sweden). Dept. of Orthopaedics; Larsson, H. [Nacka-Soeder Hospital, Stockholm (Sweden). Dept. of Radiology

    1998-09-01

    The value of MRI for the evaluation of anterior shoulder instability can be enhanced by shoulder positions that stress the stabilising structures. The ABER position is one that has been described in combination with intra-articular gadopentetate dimeglumine arthrography. We believe that MRI in the Apprehension test position with 90 abduction and maximal tolerable external rotation provides maximum tension on the anterior stabilising structures and with this technique it is sufficient to use indirect gadodiamide arthrography following intravenous injection of the contrast medium. The purpose of this study was to make a prospective comparative evaluation of the ABER and Apprehension test positions when using indirect arthrography with intravenous gadodiamide administration in shoulders with anterior instability. Results. Both the ABER and the Apprehension test position were useful techniques in detecting capsulolabral pathology and Hill-Sachs lesions. The Apprehension test position produced significantly better gadodiamide-enhanced joint fluid in the region of pathology in both the capsulolabral lesion and the Hill-Sachs lesion. It also visualised the size of the Hill-Sachs lesion significantly better than did the ABER position. (orig.)

  4. Discursive Positionings and Emotions in Modelling Activities

    Science.gov (United States)

    Daher, Wajeeh

    2015-01-01

    Mathematical modelling is suggested as an activity through which students engage in meaningful mathematics. In the current research, the modelling activity of a group of four seventh-grade students was analysed using the discursive analysis framework. The research findings show that the positionings and emotions of the group members during their…

  5. Modeling and position control of tethered octocopters

    Directory of Open Access Journals (Sweden)

    de Castro Davi Ferreira

    2016-01-01

    Full Text Available This work presents the modeling and control of a multirotor aerial vehicle with tethered configuration. It is considered an octocopter with a saturated proportional-plus-derivative position control. A viscoelastic model is considered for the tether, which has a tension control. Numerical simulations are carried out to compare the performance of the tethred configuration with the vehicle in free flight.

  6. A Program for Standard Errors of Indirect Effects in Recursive Causal Models.

    Science.gov (United States)

    Wolfle, Lee M.; Ethington, Corinna A.

    In his early exposition of path analysis, Duncan (1966) noted that the method "provides a calculus for indirect effects." Despite the interest in indirect causal effects, most users treat them as if they are population parameters and do not test whether they are statistically significant. Sobel (1982) has recently derived the asymptotic…

  7. Pneumococcal transmission and disease in silico: a microsimulation model of the indirect effects of vaccination.

    Directory of Open Access Journals (Sweden)

    Markku Nurhonen

    Full Text Available BACKGROUND: The degree and time frame of indirect effects of vaccination (serotype replacement and herd immunity are key determinants in assessing the net effectiveness of vaccination with pneumococcal conjugate vaccines (PCV in control of pneumococcal disease. Using modelling, we aimed to quantify these effects and their dependence on coverage of vaccination and the vaccine's efficacy against susceptibility to pneumococcal carriage. METHODS AND FINDINGS: We constructed an individual-based simulation model that explores the effects of large-scale PCV programmes and applied it in a developed country setting (Finland. A population structure with transmission of carriage taking place within relevant mixing groups (families, day care groups, schools and neighbourhoods was considered in order to properly assess the dependency of herd immunity on coverage of vaccination and vaccine efficacy against carriage. Issues regarding potential serotype replacement were addressed by employing a novel competition structure between multiple pneumococcal serotypes. Model parameters were calibrated from pre-vaccination data about the age-specific carriage prevalence and serotype distribution. The model predicts that elimination of vaccine-type carriage and disease among those vaccinated and, due to a substantial herd effect, also among the general population takes place within 5-10 years since the onset of a PCV programme with high (90% coverage of vaccination and moderate (50% vaccine efficacy against acquisition of carriage. A near-complete replacement of vaccine-type carriage by non-vaccine-type carriage occurs within the same time frame. CONCLUSIONS: The changed patterns in pneumococcal carriage after PCV vaccination predicted by the model are unequivocal. The overall effect on disease incidence depends crucially on the magnitude of age- and serotype-specific case-to-carrier ratios of the remaining serotypes relative to those of the vaccine types. Thus the

  8. Modeling of indirect carbon fuel cell systems with steam and dry gasification

    Science.gov (United States)

    Ong, Katherine M.; Ghoniem, Ahmed F.

    2016-05-01

    An indirect carbon fuel cell (ICFC) system that couples coal gasification to a solid oxide fuel cell (SOFC) is a promising candidate for high efficiency stationary power. This study couples an equilibrium gasifier model to a detailed 1D MEA model to study the theoretical performance of an ICFC system run on steam or carbon dioxide. Results show that the fuel cell in the ICFC system is capable of power densities greater than 1.0 W cm-2 with H2O recycle, and power densities ranging from 0.2 to 0.4 W cm-2 with CO2 recycle. This result indicates that the ICFC system performs better with steam than with CO2 gasification as a result of the faster electro-oxidation kinetics of H2 relative to CO. The ICFC system is then shown to reach higher current densities and efficiencies than a thermally decoupled gasifier + fuel cell (G + FC) system because it does not include combustion losses associated with autothermal gasification. 55-60% efficiency is predicted for the ICFC system coupled to a bottoming cycle, making this technology competitive with other state-of-the-art stationary power candidates.

  9. Thermodynamic modelling and efficiency analysis of a class of real indirectly fired gas turbine cycles

    Directory of Open Access Journals (Sweden)

    Ma Zheshu

    2009-01-01

    Full Text Available Indirectly or externally-fired gas-turbines (IFGT or EFGT are novel technology under development for small and medium scale combined power and heat supplies in combination with micro gas turbine technologies mainly for the utilization of the waste heat from the turbine in a recuperative process and the possibility of burning biomass or 'dirty' fuel by employing a high temperature heat exchanger to avoid the combustion gases passing through the turbine. In this paper, by assuming that all fluid friction losses in the compressor and turbine are quantified by a corresponding isentropic efficiency and all global irreversibilities in the high temperature heat exchanger are taken into account by an effective efficiency, a one dimensional model including power output and cycle efficiency formulation is derived for a class of real IFGT cycles. To illustrate and analyze the effect of operational parameters on IFGT efficiency, detailed numerical analysis and figures are produced. The results summarized by figures show that IFGT cycles are most efficient under low compression ratio ranges (3.0-6.0 and fit for low power output circumstances integrating with micro gas turbine technology. The model derived can be used to analyze and forecast performance of real IFGT configurations.

  10. A Global Circuit Tool for Modeling Lightning Indirect Effects on Aircraft

    Science.gov (United States)

    Moussa, H.; Abdi, M.; Issac, F.; Prost, D.

    The topic of this study is electromagnetic environment and electromagnetic interference (EMI) effects, specifically the modeling of lightning indirect effects on aircraft electrical systems present on embedded and highly exposed equipments, such as nose landing gear (NLG) and nacelles, through a circuit approach. The main goal of the presented work, funded by a French national project, PREFACE, is to propose a simple equivalent electrical circuit to represent a geometrical structure, taking into account mutual, self-inductances, and resistances, which play a fundamental role in the lightning current distribution. Then this model is intended to be coupled to a functional one, describing a power train chain composed of a converter, a shielded power harness, and a motor or a set of resistors used as a load for the converter. The novelty here is to provide a pre-sizing qualitative approach allowing playing on integration in pre-design phases. This tool intends to offer a user-friendly way for replying rapidly to calls for tender, taking into account the lightning constraints.

  11. Indirect iterative learning control for a discrete visual servo without a camera-robot model.

    Science.gov (United States)

    Jiang, Ping; Bamforth, Leon C A; Feng, Zuren; Baruch, John E F; Chen, YangQuan

    2007-08-01

    This paper presents a discrete learning controller for vision-guided robot trajectory imitation with no prior knowledge of the camera-robot model. A teacher demonstrates a desired movement in front of a camera, and then, the robot is tasked to replay it by repetitive tracking. The imitation procedure is considered as a discrete tracking control problem in the image plane, with an unknown and time-varying image Jacobian matrix. Instead of updating the control signal directly, as is usually done in iterative learning control (ILC), a series of neural networks are used to approximate the unknown Jacobian matrix around every sample point in the demonstrated trajectory, and the time-varying weights of local neural networks are identified through repetitive tracking, i.e., indirect ILC. This makes repetitive segmented training possible, and a segmented training strategy is presented to retain the training trajectories solely within the effective region for neural network approximation. However, a singularity problem may occur if an unmodified neural-network-based Jacobian estimation is used to calculate the robot end-effector velocity. A new weight modification algorithm is proposed which ensures invertibility of the estimation, thus circumventing the problem. Stability is further discussed, and the relationship between the approximation capability of the neural network and the tracking accuracy is obtained. Simulations and experiments are carried out to illustrate the validity of the proposed controller for trajectory imitation of robot manipulators with unknown time-varying Jacobian matrices.

  12. In-residence, multiple route exposures to chlorpyrifos and diazinon estimated by indirect method models

    Science.gov (United States)

    Moschandreas, D. J.; Kim, Y.; Karuchit, S.; Ari, H.; Lebowitz, M. D.; O'Rourke, M. K.; Gordon, S.; Robertson, G.

    One of the objectives of the National Human Exposure Assessment Survey (NHEXAS) is to estimate exposures to several pollutants in multiple media and determine their distributions for the population of Arizona. This paper presents modeling methods used to estimate exposure distributions of chlorpyrifos and diazinon in the residential microenvironment using the database generated in Arizona (NHEXAS-AZ). A four-stage probability sampling design was used for sample selection. Exposures to pesticides were estimated using the indirect method of exposure calculation by combining measured concentrations of the two pesticides in multiple media with questionnaire information such as time subjects spent indoors, dietary and non-dietary items they consumed, and areas they touched. Most distributions of in-residence exposure to chlorpyrifos and diazinon were log-normal or nearly log-normal. Exposures to chlorpyrifos and diazinon vary by pesticide and route as well as by various demographic characteristics of the subjects. Comparisons of exposure to pesticides were investigated among subgroups of demographic categories, including gender, age, minority status, education, family income, household dwelling type, year the dwelling was built, pesticide use, and carpeted areas within dwellings. Residents with large carpeted areas within their dwellings have higher exposures to both pesticides for all routes than those in less carpet-covered areas. Depending on the route, several other determinants of exposure to pesticides were identified, but a clear pattern could not be established regarding the exposure differences between several subpopulation groups.

  13. High-resolution modeling of indirectly driven high-convergence layered inertial confinement fusion capsule implosions

    Science.gov (United States)

    Haines, Brian M.; Aldrich, C. H.; Campbell, J. M.; Rauenzahn, R. M.; Wingate, C. A.

    2017-05-01

    In this paper, we present the results of high-resolution simulations of the implosion of high-convergence layered indirect-drive inertial confinement fusion capsules of the type fielded on the National Ignition Facility using the xRAGE radiation-hydrodynamics code. In order to evaluate the suitability of xRAGE to model such experiments, we benchmark simulation results against available experimental data, including shock-timing, shock-velocity, and shell trajectory data, as well as hydrodynamic instability growth rates. We discuss the code improvements that were necessary in order to achieve favorable comparisons with these data. Due to its use of adaptive mesh refinement and Eulerian hydrodynamics, xRAGE is particularly well suited for high-resolution study of multi-scale engineering features such as the capsule support tent and fill tube, which are known to impact the performance of high-convergence capsule implosions. High-resolution two-dimensional (2D) simulations including accurate and well-resolved models for the capsule fill tube, support tent, drive asymmetry, and capsule surface roughness are presented. These asymmetry seeds are isolated in order to study their relative importance and the resolution of the simulations enables the observation of details that have not been previously reported. We analyze simulation results to determine how the different asymmetries affect hotspot reactivity, confinement, and confinement time and how these combine to degrade yield. Yield degradation associated with the tent occurs largely through decreased reactivity due to the escape of hot fuel mass from the hotspot. Drive asymmetries and the fill tube, however, degrade yield primarily via burn truncation, as associated instability growth accelerates the disassembly of the hotspot. Modeling all of these asymmetries together in 2D leads to improved agreement with experiment but falls short of explaining the experimentally observed yield degradation, consistent with previous

  14. Modeling Human Exposure to Phthalate Esters: A Comparison of Indirect and Biomonitoring Estimation Methods

    Science.gov (United States)

    Clark, Kathryn E.; David, Raymond M.; Guinn, Richard; Kramarz, Kurt W.; Lampi, Mark A.; Staples, Charles A.

    2011-01-01

    Humans are potentially exposed to phthalate esters (PEs) through ingestion, inhalation, and dermal contact. Studies quantifying exposure to PEs include “biomarker studies” and “indirect studies.” Biomarker studies use measurements of PE metabolites in urine to back-calculate exposure to the parent diester, while indirect studies use the concentration of the PE in each medium of exposure and the rate of intake of that medium to quantify intake of the PE. In this review, exposure estimates from biomarker and indirect studies are compiled and compared for seven PEs to determine if there are regional differences and if there is a preferred approach. The indirect and biomarker methods generally agree with each other within an order of magnitude and discrepancies are explained by difficulties in accounting for use of consumer products, uncertainty concerning absorption, regional differences, and temporal changes. No single method is preferred for estimating intake of all PEs; it is suggested that biomarker estimates be used for low molecular weight PEs for which it is difficult to quantify all sources of exposure and either indirect or biomarker methods be used for higher molecular weight PEs. The indirect methods are useful in identifying sources of exposure while the biomarker methods quantify exposure. PMID:23087593

  15. An Indirect Data Assimilation Scheme for Deep Soil Temperature in the Pleim-Xiu Land Surface Model

    Science.gov (United States)

    The Pleim-Xiu land surface model (PX LSM) has been improved by the addition of a 2nd indirect data assimilation scheme. The first, which was described previously, is a technique where soil moisture in nudged according to the biases in 2-m air temperature and relative humidity be...

  16. SPSS and SAS procedures for estimating indirect effects in simple mediation models.

    Science.gov (United States)

    Preacher, Kristopher J; Hayes, Andrew F

    2004-11-01

    Researchers often conduct mediation analysis in order to indirectly assess the effect of a proposed cause on some outcome through a proposed mediator. The utility of mediation analysis stems from its ability to go beyond the merely descriptive to a more functional understanding of the relationships among variables. A necessary component of mediation is a statistically and practically significant indirect effect. Although mediation hypotheses are frequently explored in psychological research, formal significance tests of indirect effects are rarely conducted. After a brief overview of mediation, we argue the importance of directly testing the significance of indirect effects and provide SPSS and SAS macros that facilitate estimation of the indirect effect with a normal theory approach and a bootstrap approach to obtaining confidence intervals, as well as the traditional approach advocated by Baron and Kenny (1986). We hope that this discussion and the macros will enhance the frequency of formal mediation tests in the psychology literature. Electronic copies of these macros may be downloaded from the Psychonomic Society's Web archive at www.psychonomic.org/archive/.

  17. Maladaptive Five Factor Model personality traits associated with Borderline Personality Disorder indirectly affect susceptibility to suicide ideation through increased anxiety sensitivity cognitive concerns.

    Science.gov (United States)

    Tucker, Raymond P; Lengel, Greg J; Smith, Caitlin E; Capron, Dan W; Mullins-Sweatt, Stephanie N; Wingate, LaRicka R

    2016-12-30

    The current study investigated the relationship between maladaptive Five-Factor Model (FFM) personality traits, anxiety sensitivity cognitive concerns, and suicide ideation in a sample of 131 undergraduate students who were selected based on their scores on a screening questionnaire regarding Borderline Personality Disorder (BPD) symptoms. Those who endorsed elevated BPD symptoms in a pre-screen analyses completed at the beginning of each semester were oversampled in comparison to those with low or moderate symptoms. Indirect effect (mediation) results indicated that the maladaptive personality traits of anxious/uncertainty, dysregulated anger, self-disturbance, behavioral dysregulation, dissociative tendencies, distrust, manipulativeness, oppositional, and rashness had indirect effects on suicide ideation through anxiety sensitivity cognitive concerns. All of these personality traits correlated to suicide ideation as well. The maladaptive personality traits of despondence, affective dysregulation, and fragility were positive correlates of suicide ideation and predicted suicide ideation when all traits were entered in one linear regression model, but were not indirectly related through anxiety sensitivity cognitive concerns. The implication for targeting anxiety sensitivity cognitive concerns in evidence-based practices for reducing suicide risk in those with BPD is discussed. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  18. Basic model of fermion dark matter. Indirect detection of supersymmetric dark matter in {gamma} astronomy with the CELESTE telescope; Modele effectif de matiere noire fermionique. Detection indirecte de matiere noire supersymetrique en astronomie {gamma} avec le telescope CELESTE

    Energy Technology Data Exchange (ETDEWEB)

    Lavalle, J

    2004-10-15

    The purpose of this thesis is to discuss both phenomenological and experimental aspects of Dark Matter, related to its indirect detection with gamma-ray astronomy. In the MSSM (Minimal Supersymmetric Standard Model) framework, neutralinos arise as natural candidates to non-baryonic and Cold Dark Matter, whose gravitational effects manifest in the Universe at different scales. As they are Majorana particles, they may in principle annihilate in high density regions, as the centres of galaxies, and produce gamma rays. Nevertheless, the expected fluxes are basically low compared to experimental sensitivities. After estimating gamma fluxes from M31 and Draco galaxies in the MSSM scheme, we first generalize the MSSM couplings by studying an effective Lagrangian. We show that the only constraint of imposing a relic abundance compatible with recent measurements obviously deplete significantly the gamma ray production, but also that predictions in this effective approach are more optimistic for indirect detection than the MSSM. In a second part, we present the indirect searches for Dark Matter performed with the CELESTE Cherenkov telescope towards the galaxy M31. We propose a statistical method to reconstruct spectra, mandatory to discriminate classical and exotic spectra. The M31 data analysis enables the extraction of an upper limit on the gamma ray flux, which is the first worldwide for a galaxy in the energy range 50-500 GeV, and whose astrophysical interest goes beyond indirect searches for Dark Matter. (author)

  19. Siblings’ Perceptions of Differential Treatment, Fairness, and Jealousy and Adolescent Adjustment: A Moderated Indirect Effects Model

    Science.gov (United States)

    Loeser, Meghan K.; Whiteman, Shawn D.; McHale, Susan M.

    2016-01-01

    Youth's perception of parents’ differential treatment (PDT) are associated with maladjustment during adolescence. Although the direct relations between PDT and youth's maladjustment have been well established, the mechanisms underlying these associations remain unclear. We addressed this gap by examining whether sibling jealousy accounted for the links between PDT and youth's depressive symptoms, self-worth, and risky behaviors. Additionally, we examined whether youth's perceptions of fairness regarding their treatment as well as the gender constellation of the dyad moderated these indirect relations (i.e., moderated-indirect effects). Participants were first- and second-born adolescent siblings (M = 15.96, SD = .72 years for older siblings, M = 13.48, SD = 1.02 years for younger siblings) and their parents from 197 working and middle class European American families. Data were collected via home interviews. A series of Conditional Process Analyses revealed significant indirect effects of PDT through sibling jealousy to all three adjustment outcomes. Furthermore, perceptions of fairness moderated the relations between PDT and jealousy, such that the indirect effects were only significant at low (−1 SD) and average levels of fairness. At high levels of fairness (+1 SD) there was no association between PDT, jealousy, and youth adjustment. Taken together, results indicate that youth and parents would benefit from engaging in clear communication regarding the reasoning for the occurrence of differential treatment, likely maximizing youth and parent perceptions of that treatment as being fair, and in turn mitigating sibling jealousy and maladjustment. PMID:27867295

  20. Siblings' Perceptions of Differential Treatment, Fairness, and Jealousy and Adolescent Adjustment: A Moderated Indirect Effects Model.

    Science.gov (United States)

    Loeser, Meghan K; Whiteman, Shawn D; McHale, Susan M

    2016-08-01

    Youth's perception of parents' differential treatment (PDT) are associated with maladjustment during adolescence. Although the direct relations between PDT and youth's maladjustment have been well established, the mechanisms underlying these associations remain unclear. We addressed this gap by examining whether sibling jealousy accounted for the links between PDT and youth's depressive symptoms, self-worth, and risky behaviors. Additionally, we examined whether youth's perceptions of fairness regarding their treatment as well as the gender constellation of the dyad moderated these indirect relations (i.e., moderated-indirect effects). Participants were first- and second-born adolescent siblings (M = 15.96, SD = .72 years for older siblings, M = 13.48, SD = 1.02 years for younger siblings) and their parents from 197 working and middle class European American families. Data were collected via home interviews. A series of Conditional Process Analyses revealed significant indirect effects of PDT through sibling jealousy to all three adjustment outcomes. Furthermore, perceptions of fairness moderated the relations between PDT and jealousy, such that the indirect effects were only significant at low (-1 SD) and average levels of fairness. At high levels of fairness (+1 SD) there was no association between PDT, jealousy, and youth adjustment. Taken together, results indicate that youth and parents would benefit from engaging in clear communication regarding the reasoning for the occurrence of differential treatment, likely maximizing youth and parent perceptions of that treatment as being fair, and in turn mitigating sibling jealousy and maladjustment.

  1. Digital terrain model evaluation and computation of the terrain correction and indirect effect in South America

    Directory of Open Access Journals (Sweden)

    Denizar Blitzkow

    2009-12-01

    Full Text Available The main objectives of this paper are to compare digital terrain models, to show the generated models for South America and to present two applications. Shuttle Radar Topography Mission (SRTM produced the most important and updated height information in the world. This paper addresses the attention to comparisons of the following models: SRTM3, DTM2002, GLOBE, GTOPO30, ETOPO2 and ETOPO5, at the common points of the grid. The comparisons are limited by latitudes 60º S and 25 º N and longitudes 100 º W and 25 º W. All these data, after some analysis, have been used to create three models for South America: SAM_1mv1, SAM_1mv2 (both of 1' grid spacing and SAM_30s (30" grid spacing. Besides this effort, the three models as well as STRM were evaluated using Bench Marks (BM in Brazil and Argentina. This paper also shows two important geodesy and geophysics applications using the SAM_1mv1: terrain correction (one of the reductions applied to the gravity acceleration and indirect effect (a consequence of the reduction of the external mass to the geoid. These are important at Andes for a precise geoid computation.Los objetivos principales de este documento son comparar modelos digitales del continente; enseñar los modelos generados para Sudamérica y presentar dos aplicaciones. Shuttle Radar Topography Mission (SRTM produjo la información más importante y más actualizada de las altitudes del mundo. Este trabajo centra su atención en las comparaciones de los modelos siguientes: SRTM3, DTM2002, GLOBO, GTOPO30, ETOPO2 y ETOPO5, en los puntos comunes de la rejilla. Las comparaciones son limitadas por las latitudes 60º S y 25 º N y longitudes 100 º W y 25 º W. Todos estos datos, después de los análisis, se han utilizado para crear tres modelos para Sudamérica: SAM_1mv1, SAM_1mv2 (1' de espaciamiento de la rejilla y SAM_30s (30" de espaciamiento de la rejilla. Los tres modelos bien como el STRM fueron evaluados usando puntos de referencia de

  2. Indirect calorimetry

    NARCIS (Netherlands)

    Gerrits, W.J.J.; Labussière, E.

    2015-01-01

    The use of indirect calorimetry to measure the heat production of men and animals has increased rapidly since the pioneering work of Lavoisier. Measurement of the consumption of oxygen and production of carbon dioxide are the basis for the measurement of heat production. Today, applications of indir

  3. Thermo-economic modeling of an indirectly coupled solid oxide fuel cell/gas turbine hybrid power plant

    Energy Technology Data Exchange (ETDEWEB)

    Cheddie, Denver F. [Center for Energy Studies, University of Trinidad and Tobago, Point Lisas Campus, Esperanza Road, Brechin Castle, Couva (Trinidad and Tobago); Tobago; Murray, Renique [Natural Gas Institute of the Americas, University of Trinidad and Tobago, Point Lisas Campus, Esperanza Road, Brechin Castle, Couva (Trinidad and Tobago); Tobago

    2010-12-15

    Power generation using gas turbine (GT) power plants operating on the Brayton cycle suffers from low efficiencies, resulting in poor fuel to power conversion. A solid oxide fuel cell (SOFC) is proposed for integration into a 10 MW gas turbine power plant, operating at 30% efficiency, in order to improve system efficiencies and economics. The SOFC system is indirectly coupled to the gas turbine power plant, paying careful attention to minimize the disruption to the GT operation. A thermo-economic model is developed for the hybrid power plant, and predicts an optimized power output of 20.6 MW at 49.9% efficiency. The model also predicts a break-even per-unit energy cost of USD 4.65 cents kWh{sup -1} for the hybrid system based on futuristic mass generation SOFC costs. This shows that SOFCs may be indirectly integrated into existing GT power systems to improve their thermodynamic and economic performance. (author)

  4. Geophysical Fluid Dynamics Laboratory general circulation model investigation of the indirect radiative effects of anthropogenic sulfate aerosol

    Science.gov (United States)

    Ming, Yi; Ramaswamy, V.; Ginoux, Paul A.; Horowitz, Larry W.; Russell, Lynn M.

    2005-11-01

    The Geophysical Fluid Dynamics Laboratory (GFDL) atmosphere general circulation model, with its new cloud scheme, is employed to study the indirect radiative effect of anthropogenic sulfate aerosol during the industrial period. The preindustrial and present-day monthly mean aerosol climatologies are generated from running the Model for Ozone And Related chemical Tracers (MOZART) chemistry-transport model. The respective global annual mean sulfate burdens are 0.22 and 0.81 Tg S. Cloud droplet number concentrations are related to sulfate mass concentrations using an empirical relationship (Boucher and Lohmann, 1995). A distinction is made between "forcing" and flux change at the top of the atmosphere in this study. The simulations, performed with prescribed sea surface temperature, show that the first indirect "forcing" ("Twomey" effect) amounts to an annual mean of -1.5 W m-2, concentrated largely over the oceans in the Northern Hemisphere (NH). The annual mean flux change owing to the response of the model to the first indirect effect is -1.4 W m-2, similar to the annual mean forcing. However, the model's response causes a rearrangement of cloud distribution as well as changes in longwave flux (smaller than solar flux changes). There is thus a differing geographical nature of the radiation field than for the forcing even though the global means are similar. The second indirect effect, which is necessarily an estimate made in terms of the model's response, amounts to -0.9 W m-2, but the statistical significance of the simulated geographical distribution of this effect is relatively low owing to the model's natural variability. Both the first and second effects are approximately linearly additive, giving rise to a combined annual mean flux change of -2.3 W m-2, with the NH responsible for 77% of the total flux change. Statistically significant model responses are obtained for the zonal mean total indirect effect in the entire NH and in the Southern Hemisphere low

  5. Balancing direct and indirect sources of navigational information in a leaderless model of collective animal movement.

    Science.gov (United States)

    Codling, Edward A; Bode, Nikolai W F

    2016-04-07

    Navigation is an important movement process that enables individuals and groups of animals to find targets in space at different spatio-temporal scales. Earlier studies have shown how being in a group can confer navigational advantages to individuals, either through following more experienced leaders or through the pooling of many inaccurate compasses, a process known as the 'many wrongs principle'. However, the exact mechanisms for how information is transferred and used within the group in order to improve both individual- and group-level navigational performance are not fully understood. Here we explore the relative weighting that should be given to different sources of navigational information by an individual within a navigating group at each step of the movement process. Specifically, we consider a direct goal-oriented source of navigational information such as the individual׳s own imperfect knowledge of the target (a 'noisy compass') alongside two indirect sources of navigational information: the previous movement directions of neighbours in the group (social information) and, for the first time in this context, the previous movement direction of the individual (persistence). We assume that all individuals are equal in their abilities and that direct navigational information is prone to higher errors than indirect information. Using computer simulations, we show that in such situations giving a high weighting to either type of indirect navigational information can serve to significantly improve the navigation success of groups. Crucially, we also show that if the quality of social information is reduced, e.g. by an individual׳s limited cognitive abilities, the best navigational strategy for groups assigns a considerable weighting to persistence, a behaviour that is neither social, nor directly aimed at navigating.

  6. Modeling of the Second Indirect Effect of Anthropogenic Aerosols in East Asia

    Institute of Scientific and Technical Information of China (English)

    WU Peng-Ping; HAN Zhi-Wei

    2011-01-01

    This study investigated the second indirect climatic effect of anthropogenic aerosols, including sulfate, organic carbon (OC), and black carbon (BC), over East Asia. The seasonal variation of the climatic response to the second indirect effect was also characterized. The simulation period for this study was 2006. Due to a decrease in autoconversion rate from cloud water to rain as a result of aerosols, the cloud liquid water path (LWP), and radiative flux (RF) at the top of the atmosphere (TOA) changed dramatically, increasing by 14.3 g m^2 and de- creasing by -4.1 W m^2 in terms of domain and annual average. Both LWP and RF changed most in autumn. There were strong decreases in ground temperature in Southwest China, the middle reaches of the Yangtze River in spring and autumn, while maximum cooling of up to -1.5 K occurred in the Chongqing district. The regional and annual mean change in ground temperature reached -0.2 K over eastern China. In all seasons except summer, precipitation generally decreased in most areas north of the Yangtze River, whereas precipitation changed little in South China, Precipitation changed most in summer, with alternating bands of increasing (-40 mm) and decreasing (-40 mm) precipitation appearing in eastern China. Precipitation decreased by 1.5-40 mm over large areas of Northeast China and the Huabei Plain. The domain and annual mean change in precipitation was approximately 0.3 mm over eastern China. The maximum reduction in precipitation occurred in summer, with mean absolute and relative changes of-1.2 mm and -3.8% over eastern China. This study revealed considerable climate responses to the second indirect effect of aerosols over specific regions of China.

  7. Behavioral Self-Regulation and Weight-Related Behaviors in Inner-City Adolescents: A Model of Direct and Indirect Effects.

    Science.gov (United States)

    Isasi, Carmen R; Wills, Thomas A

    2011-08-01

    BACKGROUND: This study examined the association of two distinct self-regulation constructs, effortful control and dysregulation, with weight-related behaviors in adolescents and tested whether these effects were mediated by self-efficacy variables. METHODS: A school-based survey was conducted with 1771 adolescents from 11 public schools in the Bronx, New York. Self-regulation was assessed by multiple indicators and defined as two latent constructs. Dependent variables included fruit/vegetable intake, intake of snack/junk food, frequency of physical activity, and time spent in sedentary behaviors. Structural equation modeling examined the relation of effortful control and dysregulation to lifestyle behaviors, with self-efficacy variables as possible mediators. RESULTS: Study results showed that effortful control had a positive indirect effect on fruit and vegetable intake, mediated by self-efficacy, as well as a direct effect. Effortful control also had a positive indirect effect on physical activity, mediated by self-efficacy. Dysregulation had direct effects on intake of junk food/snacks and time spent in sedentary behaviors. CONCLUSIONS: These findings indicate that self-regulation characteristics are related to diet and physical activity and that some of these effects are mediated by self-efficacy. Different effects were noted for the two domains of self-regulation. Prevention researchers should consider including self-regulation processes in programs to improve health behaviors in adolescents.

  8. Indirect CO2 Emission Implications of Energy System Pathways: Linking IO and TIMES Models for the UK.

    Science.gov (United States)

    Daly, Hannah E; Scott, Kate; Strachan, Neil; Barrett, John

    2015-09-01

    Radical changes to current national energy systems-including energy efficiency and the decarbonization of electricity-will be required in order to meet challenging carbon emission reduction commitments. Technology explicit energy system optimization models (ESOMs) are widely used to define and assess such low-carbon pathways, but these models only account for the emissions associated with energy combustion and either do not account for or do not correctly allocate emissions arising from infrastructure, manufacturing, construction and transport associated with energy technologies and fuels. This paper addresses this shortcoming, through a hybrid approach that estimates the upstream CO2 emissions across current and future energy technologies for the UK using a multiregional environmentally extended input-output model, and explicitly models the direct and indirect CO2 emissions of energy supply and infrastructure technologies within a national ESOM (the UK TIMES model). Results indicate the large significance of nondomestic indirect emissions, particularly coming from fossil fuel imports, and finds that the marginal abatement cost of mitigating all emissions associated with UK energy supply is roughly double that of mitigating only direct emissions in 2050.

  9. HEPPA-II model-measurement intercomparison project: EPP indirect effects during the dynamically perturbed NH winter 2008-2009

    Science.gov (United States)

    Funke, Bernd; Ball, William; Bender, Stefan; Gardini, Angela; Harvey, V. Lynn; Lambert, Alyn; López-Puertas, Manuel; Marsh, Daniel R.; Meraner, Katharina; Nieder, Holger; Päivärinta, Sanna-Mari; Pérot, Kristell; Randall, Cora E.; Reddmann, Thomas; Rozanov, Eugene; Schmidt, Hauke; Seppälä, Annika; Sinnhuber, Miriam; Sukhodolov, Timofei; Stiller, Gabriele P.; Tsvetkova, Natalia D.; Verronen, Pekka T.; Versick, Stefan; von Clarmann, Thomas; Walker, Kaley A.; Yushkov, Vladimir

    2017-03-01

    We compare simulations from three high-top (with upper lid above 120 km) and five medium-top (with upper lid around 80 km) atmospheric models with observations of odd nitrogen (NOx = NO + NO2), temperature, and carbon monoxide from seven satellite instruments (ACE-FTS on SciSat, GOMOS, MIPAS, and SCIAMACHY on Envisat, MLS on Aura, SABER on TIMED, and SMR on Odin) during the Northern Hemisphere (NH) polar winter 2008/2009. The models included in the comparison are the 3-D chemistry transport model 3dCTM, the ECHAM5/MESSy Atmospheric Chemistry (EMAC) model, FinROSE, the Hamburg Model of the Neutral and Ionized Atmosphere (HAMMONIA), the Karlsruhe Simulation Model of the Middle Atmosphere (KASIMA), the modelling tools for SOlar Climate Ozone Links studies (SOCOL and CAO-SOCOL), and the Whole Atmosphere Community Climate Model (WACCM4). The comparison focuses on the energetic particle precipitation (EPP) indirect effect, that is, the polar winter descent of NOx largely produced by EPP in the mesosphere and lower thermosphere. A particular emphasis is given to the impact of the sudden stratospheric warming (SSW) in January 2009 and the subsequent elevated stratopause (ES) event associated with enhanced descent of mesospheric air. The chemistry climate model simulations have been nudged toward reanalysis data in the troposphere and stratosphere while being unconstrained above. An odd nitrogen upper boundary condition obtained from MIPAS observations has further been applied to medium-top models. Most models provide a good representation of the mesospheric tracer descent in general, and the EPP indirect effect in particular, during the unperturbed (pre-SSW) period of the NH winter 2008/2009. The observed NOx descent into the lower mesosphere and stratosphere is generally reproduced within 20 %. Larger discrepancies of a few model simulations could be traced back either to the impact of the models' gravity wave drag scheme on the polar wintertime meridional circulation or

  10. Positive Psychology versus the Medical Model?: Comment

    Science.gov (United States)

    Joseph, Stephen; Linley, P. Alex

    2006-01-01

    Comments on "Positive psychology progress: Empirical validation of interventions" by Seligman, Steen, Park, and Peterson (see record 2005-08033-003). Seligman and colleagues provided a progress report on positive psychology, reviewing the impressive developments over the past five years. We wholeheartedly support the positive psychology movement…

  11. POSITIVE LEADERSHIP MODELS: THEORETICAL FRAMEWORK AND RESEARCH

    Directory of Open Access Journals (Sweden)

    Javier Blanch, Francisco Gil

    2016-09-01

    Full Text Available The objective of this article is twofold; firstly, we establish the theoretical boundaries of positive leadership and the reasons for its emergence. It is related to the new paradigm of positive psychology that has recently been shaping the scope of organizational knowledge. This conceptual framework has triggered the development of the various forms of positive leadership (i.e. transformational, servant, spiritual, authentic, and positive. Although the construct does not seem univocally defined, these different types of leadership overlap and share a significant affinity. Secondly, we review the empirical evidence that shows the impact of positive leadership in organizations and we highlight the positive relationship between these forms of leadership and key positive organizational variables. Lastly, we analyse future research areas in order to further develop this concept.

  12. A model for the direct-to-indirect band-gap transition in monolayer MoSe2 under strain

    Indian Academy of Sciences (India)

    Ruma Das; Priya Mahadevan

    2015-06-01

    A monolayer of MoSe2 is found to be a direct band-gap semiconductor. We show, within ab-initio electronic structure calculations, that a modest biaxial tensile strain of 3% can drive it into an indirect band-gap semiconductor with the valence band maximum (VBM) shifting from point to point. An analysis of the charge density reveals that while Mo–Mo interactions contribute to the VBM at 0% strain, Mo–Se interactions contribute to the highest occupied band at point. A scaling of the hopping interaction strengths within an appropriate tight binding model can capture the transition.

  13. Multilevel Modeling of Item Position Effects

    Science.gov (United States)

    Albano, Anthony D.

    2013-01-01

    In many testing programs it is assumed that the context or position in which an item is administered does not have a differential effect on examinee responses to the item. Violations of this assumption may bias item response theory estimates of item and person parameters. This study examines the potentially biasing effects of item position. A…

  14. Solar Position Model for use in DIORAMA

    Energy Technology Data Exchange (ETDEWEB)

    Werley, Kenneth Alan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-03-01

    The DIORAMA code requires the solar position relative to earth in order to compute GPS satellite orientation. The present document describes two functions that compute the unit vector from either the center of the Earth to the Sun or from any observer’s position to the Sun at some specified time. Another function determines if a satellite lies within the Earth’s shadow umbra. Similarly, functions determine the position of the moon and whether a satellite lies within the Moon’s shadow umbra.

  15. hybridMANTIS: a CPU-GPU Monte Carlo method for modeling indirect x-ray detectors with columnar scintillators.

    Science.gov (United States)

    Sharma, Diksha; Badal, Andreu; Badano, Aldo

    2012-04-21

    The computational modeling of medical imaging systems often requires obtaining a large number of simulated images with low statistical uncertainty which translates into prohibitive computing times. We describe a novel hybrid approach for Monte Carlo simulations that maximizes utilization of CPUs and GPUs in modern workstations. We apply the method to the modeling of indirect x-ray detectors using a new and improved version of the code MANTIS, an open source software tool used for the Monte Carlo simulations of indirect x-ray imagers. We first describe a GPU implementation of the physics and geometry models in fastDETECT2 (the optical transport model) and a serial CPU version of the same code. We discuss its new features like on-the-fly column geometry and columnar crosstalk in relation to the MANTIS code, and point out areas where our model provides more flexibility for the modeling of realistic columnar structures in large area detectors. Second, we modify PENELOPE (the open source software package that handles the x-ray and electron transport in MANTIS) to allow direct output of location and energy deposited during x-ray and electron interactions occurring within the scintillator. This information is then handled by optical transport routines in fastDETECT2. A load balancer dynamically allocates optical transport showers to the GPU and CPU computing cores. Our hybridMANTIS approach achieves a significant speed-up factor of 627 when compared to MANTIS and of 35 when compared to the same code running only in a CPU instead of a GPU. Using hybridMANTIS, we successfully hide hours of optical transport time by running it in parallel with the x-ray and electron transport, thus shifting the computational bottleneck from optical tox-ray transport. The new code requires much less memory than MANTIS and, asa result, allows us to efficiently simulate large area detectors.

  16. Correction of approximation errors with Random Forests applied to modelling of aerosol first indirect effect

    Directory of Open Access Journals (Sweden)

    A. Lipponen

    2013-04-01

    Full Text Available In atmospheric models, due to their computational time or resource limitations, physical processes have to be simulated using reduced models. The use of a reduced model, however, induces errors to the simulation results. These errors are referred to as approximation errors. In this paper, we propose a novel approach to correct these approximation errors. We model the approximation error as an additive noise process in the simulation model and employ the Random Forest (RF regression algorithm for constructing a computationally low cost predictor for the approximation error. In this way, the overall simulation problem is decomposed into two separate and computationally efficient simulation problems: solution of the reduced model and prediction of the approximation error realization. The approach is tested for handling approximation errors due to a reduced coarse sectional representation of aerosol size distribution in a cloud droplet activation calculation. The results show a significant improvement in the accuracy of the simulation compared to the conventional simulation with a reduced model. The proposed approach is rather general and extension of it to different parameterizations or reduced process models that are coupled to geoscientific models is a straightforward task. Another major benefit of this method is that it can be applied to physical processes that are dependent on a large number of variables making them difficult to be parameterized by traditional methods.

  17. MALDI-TOF MS applied to indirect carbapenemase detection: a validated procedure to clearly distinguish between carbapenemase-positive and carbapenemase-negative bacterial strains.

    Science.gov (United States)

    Wang, Lijun; Han, Chao; Sui, Wenjun; Wang, Mei; Lu, Xinxin

    2013-06-01

    Laboratory identification of carbapenemase-producing clinical isolates is crucial to limit the spread of the bacteria. In this study, we shall first develop the matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) assay in automatic identification of carbapenemase producers. A total of 143 well-characterized isolates were studied. After an incubation of bacteria with meropenem trihydrate, the mixture was centrifuged and the supernatant analyzed by MALDI-TOF MS. A genetic algorithm model with ClinProTools software was built using spectra of 43 carbapenemase-positive isolates and 40 carbapenemase-negative isolates after 2 h of incubation. This model was externally validated using 60 test isolates. All spectra of supernatants of the carbapenemase-negative isolates showed peak profiles comparable to that of pure meropenem (m/z 384.159, 406.140, and 428.122 of its two sodium salt variants) regardless of the incubation time tested. For the carbapenemase-positive isolates, the specific peak for meropenem at m/z 384.159 disappeared during the incubation time, two products of meropenem degradation were identified with m/z 358.18 (the decarboxylated product) and 380.161 (sodium salt of the decarboxylated product), and other degradation products were observed (native molecule with disrupted amide bond with m/z 402.169, three sodium salt variants with m/z 424.151, 446.133, and 468.115). Sixty test isolates were 100% correctly classified as carbapenemase positive and carbapenemase negative with the genetic algorithm model. MALDI-TOF MS coupled with ClinProTools is capable of rapidly, accurately, and automatically identifying carbapenemase producers.

  18. Modelling heat transport through completely positive maps

    CERN Document Server

    Wichterich, H; Gemmer, J; Henrich, M J; Michel, M; Breuer, Heinz-Peter; Gemmer, Jochen; Henrich, Markus J.; Michel, Mathias; Wichterich, Hannu

    2007-01-01

    We investigate heat transport in a spin-1/2 Heisenberg chain, coupled locally to independent thermal baths of different temperature. The analysis is carried out within the framework of the theory of open systems by means of appropriate quantum master equations. The standard microscopic derivation of the weak-coupling Lindblad equation in the secular approximation is considered, and shown to be inadequate for the description of stationary nonequilibrium properties like a non-vanishing energy current. Furthermore, we derive an alternative master equation that is capable to describe a stationary energy current and, at the same time, leads to a completely positive dynamical map. This paves the way for efficient numerical investigations of heat transport in larger systems based on Monte Carlo wave function techniques.

  19. Simulation models applied to practical learning and skill enhancement in direct and indirect ophthalmoscopy: a review

    Directory of Open Access Journals (Sweden)

    Lucas Holderegger Ricci

    2014-10-01

    Full Text Available The purpose of this review was to analyze and describe simulation methods for practical learning and training of the ophthalmoscopy exam and to organize them into specific topics relative to each principle of operation, while evaluating their preliminary results. A critical review of articles that described and evaluated simulated models for ophthalmoscopy published in the last ten years (2004-2014 was performed. One hundred articles about ophthalmology and simulation were found in national and international periodicals, but only a few discussed the examination of the posterior pole of the eye. For this study, 25 articles were considered; those articles described simulation methods, general concepts, and its actual use in ophthalmoscopy. There were many different simulation methods described, but only few articles proved their efficacy or performed a comparison between models. Review of this topic may give information for the critical analysis of the simulation devices and ideas for the development of new ones.

  20. Modeling the dynamic behavior of turbine runner blades during transients using indirect measurements

    Science.gov (United States)

    Diagne, I.; Gagnon, M.; Tahan, A.

    2016-11-01

    Turbine start-up transients are induced by the wicket gates opening sequence and generate high amplitude stress cycles. These stress cycles have a detrimental effect leading to faster crack growth in the runner blades. Using a series of direct measurements taken on a prototype runner in order to find the optimal start-up parameters exposes both the runner and the instrumentation to a series of successive damaging transient events during the optimization process. To solve this, finding sensors strongly correlated to strain gauges and whose signals can be easily obtained to identify a model to predict the strain, instead of directly measuring it, would reduce the risk, cost and downtime associated with a measurement campaign. This paper shows that turbine shaft torsion measurements is highly correlated to the strain at a runner blade hotspot, and we demonstrate that the ARMAX model can be used to represent the dynamic system in order to minimize the strain on blades.

  1. From superWIMPs to decaying dark matter. Models, bounds and indirect searches

    Energy Technology Data Exchange (ETDEWEB)

    Weniger, Christoph

    2010-06-15

    Despite lots of observational and theoretical efforts, the particle nature of dark matter remains unknown. Beyond the paradigmatic WIMPs (Weakly Interacting Massive Particles), many theoretically well motivated models exist where dark matter interacts much more weakly than electroweak with Standard Model particles. In this case new phenomena occur, like the decay of dark matter or the interference with the standard cosmology of the early Universe. In this thesis we study some of these aspects of superweakly coupled dark matter in general, and in the special case of hidden U(1){sub X} gauginos that kinetically mix with hypercharge. There, we will assume that the gauge group remains unbroken, similar to the Standard Model U(1){sub em}. We study different kinds of cosmological bounds, including bounds from thermal overproduction, from primordial nucleosynthesis and from structure formation. Furthermore, we study the possible cosmic-ray signatures predicted by this scenario, with emphasis on the electron and positron channel in light of the recent observations by PAMELA and Fermi LAT. Moreover we study the cosmic-ray signatures of decaying dark matter independently of concrete particle-physics models. In particular we analyze in how far the rise in the positron fraction above 10 GeV, as observed by PAMELA, can be explained by dark matter decay. Lastly, we concentrate on related predictions for gamma-ray observations with the Fermi LAT, and propose to use the dipole-like anisotropy of the prompt gamma-ray dark matter signal to distinguish exotic dark matter contributions from the extragalactic gamma-ray background. (orig.)

  2. Indirect detection constraints on s- and t-channel simplified models of dark matter

    Science.gov (United States)

    Carpenter, Linda M.; Colburn, Russell; Goodman, Jessica; Linden, Tim

    2016-09-01

    Recent Fermi-LAT observations of dwarf spheroidal galaxies in the Milky Way have placed strong limits on the gamma-ray flux from dark matter annihilation. In order to produce the strongest limit on the dark matter annihilation cross section, the observations of each dwarf galaxy have typically been "stacked" in a joint-likelihood analysis, utilizing optical observations to constrain the dark matter density profile in each dwarf. These limits have typically been computed only for singular annihilation final states, such as b b ¯ or τ+τ- . In this paper, we generalize this approach by producing an independent joint-likelihood analysis to set constraints on models where the dark matter particle annihilates to multiple final-state fermions. We interpret these results in the context of the most popular simplified models, including those with s- and t-channel dark matter annihilation through scalar and vector mediators. We present our results as constraints on the minimum dark matter mass and the mediator sector parameters. Additionally, we compare our simplified model results to those of effective field theory contact interactions in the high-mass limit.

  3. Direct and indirect impacts of crop-livestock organization on mixed crop-livestock systems sustainability: a model-based study.

    Science.gov (United States)

    Sneessens, I; Veysset, P; Benoit, M; Lamadon, A; Brunschwig, G

    2016-11-01

    Crop-livestock production is claimed more sustainable than specialized production systems. However, the presence of controversial studies suggests that there must be conditions of mixing crop and livestock productions to allow for higher sustainable performances. Whereas previous studies focused on the impact of crop-livestock interactions on performances, we posit here that crop-livestock organization is a key determinant of farming system sustainability. Crop-livestock organization refers to the percentage of the agricultural area that is dedicated to each production. Our objective is to investigate if crop-livestock organization has both a direct and an indirect impact on mixed crop-livestock (MC-L) sustainability. In that objective, we build a whole-farm model parametrized on representative French sheep and crop farming systems in plain areas (Vienne, France). This model permits simulating contrasted MC-L systems and their subsequent sustainability through the following indicators of performance: farm income, production, N balance, greenhouse gas (GHG) emissions (/kg product) and MJ consumption (/kg product). Two MC-L systems were simulated with contrasted crop-livestock organizations (MC20-L80: 20% of crops; MC80-L20: 80% of crops). A first scenario - constraining no crop-livestock interactions in both MC-L systems - permits highlighting that crop-livestock organization has a significant direct impact on performances that implies trade-offs between objectives of sustainability. Indeed, the MC80-L20 system is showing higher performances for farm income (+44%), livestock production (+18%) and crop GHG emissions (-14%) whereas the MC20-L80 system has a better N balance (-53%) and a lower livestock MJ consumption (-9%). A second scenario - allowing for crop-livestock interactions in both MC20-L80 and MC80-L20 systems - stated that crop-livestock organization has a significant indirect impact on performances. Indeed, even if crop-livestock interactions permit

  4. Incorporation of Advanced Activation Treatments into CESM/CAM5: Model Evaluation and Impacts on Aerosol Indirect Forcing

    Science.gov (United States)

    Gantt, B.; He, J.; Zhang, X.; Zhang, Y.; Nenes, A.

    2013-12-01

    One of the greatest sources of uncertainty in climate science is the influence of aerosols on clouds through indirect effects, especially processes affecting the activation of aerosols into cloud droplets. Aerosol activation parameterizations incorporate much of the complexity of these processes, but the small differences between parameterizations can have a large impact on the spatiotemporal distribution of activated aerosols and the resulting cloud properties. Currently, most models simulate aerosol activation using the Abdul-Razzak and Ghan [2000] (AR-G00) scheme which derives an empiric calculation of the maximum parcel supersaturation based on the regression of numerical parcel calculations. The Community Atmosphere Model version 5.1.1 within the Community Earth Systems Model version 1.0.5 (CESM/CAM5) is an online-coupled Earth Systems model that simulates the interactions among aerosols, clouds, and radiation. CESM/CAM5 uses the AR-G00 scheme to simulate aerosol activation. In this work, we update CESM/CAM5 by incorporating a series of explicit aerosol activation schemes (Fountoukis and Nenes [2005]; Barahona and Nenes [2007]; Kumar et al. [2009]; and Barahona et al. [2010]) which account for the impacts of insoluble aerosol adsorption, giant cloud condensation nuclei activation kinetics, and entrainment on cloud droplet number concentrations (CDNC). CESM/CAM5 results with the empiric and explicit aerosol activation schemes are evaluated against several global datasets including observed low-level CDNC and satellite-derived cloud optical thickness (COT), liquid water path (LWP), and shortwave cloud forcing (SWCF). Globally, the incorporation of all explicit schemes leads to an average increase in column CDNC of 155%, increase (more negative) in SWCF of 13%, and decrease in surface shortwave radiation of -4%. In terms of climate impacts, these schemes result in an annual mean decrease in surface temperature and precipitation of -0.9 K (~0.2%) and -0.04 mm day

  5. Investigation of Aerosol Indirect Effects using a Cumulus Microphysics Parameterization in a Regional Climate Model

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Kyo-Sun; Fan, Jiwen; Leung, Lai-Yung R.; Ma, Po-Lun; Singh, Balwinder; Zhao, Chun; Zhang, Yang; Zhang, Guang; Song, Xiaoliang

    2014-01-29

    A new Zhang and McFarlane (ZM) cumulus scheme includes a two-moment cloud microphysics parameterization for convective clouds. This allows aerosol effects to be investigated more comprehensively by linking aerosols with microphysical processes in both stratiform clouds that are explicitly resolved and convective clouds that are parameterized in climate models. This new scheme is implemented in the Weather Research and Forecasting (WRF) model, which is coupled with the physics and aerosol packages from the Community Atmospheric Model version 5 (CAM5). A test case of July 2008 during the East Asian summer monsoon is selected to evaluate the performance of the new ZM scheme and to investigate aerosol effects on monsoon precipitation. The precipitation and radiative fluxes simulated by the new ZM scheme show a better agreement with observations compared to simulations with the original ZM scheme that does not include convective cloud microphysics and aerosol convective cloud interactions. Detailed analysis suggests that an increase in detrained cloud water and ice mass by the new ZM scheme is responsible for this improvement. To investigate precipitation response to increased anthropogenic aerosols, a sensitivity experiment is performed that mimics a clean environment by reducing the primary aerosols and anthropogenic emissions to 30% of that used in the control simulation of a polluted environment. The simulated surface precipitation is reduced by 9.8% from clean to polluted environment and the reduction is less significant when microphysics processes are excluded from the cumulus clouds. Ensemble experiments with ten members under each condition (i.e., clean and polluted) indicate similar response of the monsoon precipitation to increasing aerosols.

  6. Indirect Watermarking

    Institute of Scientific and Technical Information of China (English)

    ZHONG Ji-dong; HUANG Shang-teng

    2007-01-01

    Watermarking system is a complex system requiring both expertise and specialized techniques with security concerns. Thus to relieve the multimedia manufacturers of the complexities of designing complicated watermarking systems, this paper presents a new watermarking model in which watermarking is provided as a kind of service by the specialized watermarking companies. In order to make this service model work, a simple permutation scheme to hide the true contents is proposed. The paper also proves the security of the scheme against the attacks from the watermarking companies. Finally, the effectiveness of the scheme is demonstrated through experiments.

  7. Modelling a Compliant-Based Precise Positioning Stage

    Directory of Open Access Journals (Sweden)

    Giedrius Augustinavičius

    2012-12-01

    Full Text Available The paper presents modelling precise dual axis flexure-based precision positioning systems for micro-positioning applications. The positioning system is featured with monolithic architecture, flexure-based joints and piezo stacks. Its workspace has been evaluated via analytical approaches. Amplification mechanism is optimally designed. The mathematical model of the positioning system has been derived and verified by resorting to finite element analysis (FEA. The established analytical and (FEA models are helpful for optimizing reliable architecture and improving the performance of the positioning system.

  8. Indirect Detection Constraints on s and t Channel Simplified Models of Dark Matter

    CERN Document Server

    Carpenter, Linda M; Goodman, Jessica; Linden, Tim

    2016-01-01

    Recent Fermi-LAT observations of dwarf spheroidal galaxies in the Milky Way have placed strong limits on the gamma-ray flux from dark matter annihilation. In order to produce the strongest limit on the dark matter annihilation cross-section, the observations of each dwarf galaxy have typically been "stacked" in a joint-likelihood analysis, utilizing optical observations to constrain the dark matter density profile in each dwarf. These limits have typically been computed only for singular annihilation final states, such as $b\\bar{b}$ or $\\tau^+\\tau^-$. In this paper, we generalize this approach by producing an independent joint-likelihood analysis to set constraints on models where the dark matter particle annihilates to multiple final state fermions. We interpret these results in the context of the most popular simplified models, including those with s- and t-channel dark matter annihilation through scalar and vector mediators. We present our results as constraints on the minimum dark matter mass and the medi...

  9. Toward a minimal representation of aerosol direct and indirect effects: model description and evaluation

    Science.gov (United States)

    Liu, X.; Easter, R. C.; Ghan, S. J.; Zaveri, R.; Rasch, P.; Shi, X.; Lamarque, J.-F.; Gettelman, A.; Morrison, H.; Vitt, F.; Conley, A.; Park, S.; Neale, R.; Hannay, C.; Ekman, A. M. L.; Hess, P.; Mahowald, N.; Collins, W.; Iacono, M. J.; Bretherton, C. S.; Flanner, M. G.; Mitchell, D.

    2011-12-01

    A modal aerosol module (MAM) has been developed for the Community Atmosphere Model version 5 (CAM5), the atmospheric component of the Community Earth System Model version 1 (CESM1). MAM is capable of simulating the aerosol size distribution and both internal and external mixing between aerosol components, treating numerous complicated aerosol processes and aerosol physical, chemical and optical properties in a physically based manner. Two MAM versions were developed: a more complete version with seven lognormal modes (MAM7), and a version with three lognormal modes (MAM3) for the purpose of long-term (decades to centuries) simulations. Major approximations in MAM3 include assuming immediate mixing of primary organic matter (POM) and black carbon (BC) with other aerosol components, merging of the MAM7 fine dust and fine sea salt modes into the accumulation mode, merging of the MAM7 coarse dust and coarse sea salt modes into the single coarse mode, and neglecting the explicit treatment of ammonia and ammonium cycles. Simulated sulfate and secondary organic aerosol (SOA) mass concentrations are remarkably similar between MAM3 and MAM7 as most (~90%) of these aerosol species are in the accumulation mode. Differences of POM and BC concentrations between MAM3 and MAM7 are also small (mostly within 10%) because of the assumed hygroscopic nature of POM, so that much of the freshly emitted POM and BC is wet-removed before mixing internally with soluble aerosol species. Sensitivity tests with the POM assumed to be hydrophobic and with slower aging increase the POM and BC concentrations, especially at high latitudes (by several times). The mineral dust global burden differs by 10% and sea salt burden by 30-40% between MAM3 and MAM7 mainly due to the different size ranges for dust and sea salt modes and different standard deviations of the log-normal size distribution for sea salt modes between MAM3 and MAM7. The model is able to qualitatively capture the observed geographical

  10. Impact of axisymmetric mass models for dwarf spheroidal galaxies on indirect dark matter searches

    CERN Document Server

    Klop, Niki; Hayashi, Kohei; Ando, Shin'ichiro

    2016-01-01

    Dwarf spheroidals are low-luminosity satellite galaxies of the Milky Way highly dominated by dark matter. Therefore, they are prime targets to search for signals from dark matter annihilation using gamma-ray observations. We analyse about 7 years of PASS8 Fermi data for seven classical dwarf galaxies, including Draco, adopting both the widely used Navarro-Frenk-White (NFW) profile and observationally motivated axisymmetric density profiles. For four of the selected dwarfs (Sextans, Carina, Sculptor and Fornax) axisymmetric mass models suggest a cored density profile rather than the commonly adopted cusped profile. We found that upper limits on the annihilation cross section for some of these dwarfs are significantly higher than the ones achieved using an NFW profile. Therefore, upper limits in the literature obtained using cusped profiles like the NFW might have been overestimated. Our results eventually show that it is extremely important to use observationally motivated density profiles going beyond the usu...

  11. Global-mean temperature change from shipping toward 2050: improved representation of the indirect aerosol effect in simple climate models.

    Science.gov (United States)

    Lund, Marianne Tronstad; Eyring, Veronika; Fuglestvedt, Jan; Hendricks, Johannes; Lauer, Axel; Lee, David; Righi, Mattia

    2012-08-21

    We utilize a range of emission scenarios for shipping to determine the induced global-mean radiative forcing and temperature change. Ship emission scenarios consistent with the new regulations on nitrogen oxides (NO(x)) and sulfur dioxide (SO(2)) from the International Maritime Organization and two of the Representative Concentration Pathways are used as input to a simple climate model (SCM). Based on a complex aerosol-climate model we develop and test new parametrizations of the indirect aerosol effect (IAE) in the SCM that account for nonlinearities in radiative forcing of ship-induced IAE. We find that shipping causes a net global cooling impact throughout the period 1900-2050 across all parametrizations and scenarios. However, calculated total net global-mean temperature change in 2050 ranges from -0.03[-0.07,-0.002]°C to -0.3[-0.6,-0.2]°C in the A1B scenario. This wide range across parametrizations emphasizes the importance of properly representing the IAE in SCMs and to reflect the uncertainties from complex global models. Furthermore, our calculations show that the future ship-induced temperature response is likely a continued cooling if SO(2) and NO(x) emissions continue to increase due to a strong increase in activity, despite current emission regulations. However, such cooling does not negate the need for continued efforts to reduce CO(2) emissions, since residual warming from CO(2) is long-lived.

  12. Spatially explicit integrated modeling and economic valuation of climate driven land use change and its indirect effects.

    Science.gov (United States)

    Bateman, Ian; Agarwala, Matthew; Binner, Amy; Coombes, Emma; Day, Brett; Ferrini, Silvia; Fezzi, Carlo; Hutchins, Michael; Lovett, Andrew; Posen, Paulette

    2016-10-01

    We present an integrated model of the direct consequences of climate change on land use, and the indirect effects of induced land use change upon the natural environment. The model predicts climate-driven shifts in the profitability of alternative uses of agricultural land. Both the direct impact of climate change and the induced shift in land use patterns will cause secondary effects on the water environment, for which agriculture is the major source of diffuse pollution. We model the impact of changes in such pollution on riverine ecosystems showing that these will be spatially heterogeneous. Moreover, we consider further knock-on effects upon the recreational benefits derived from water environments, which we assess using revealed preference methods. This analysis permits a multi-layered examination of the economic consequences of climate change, assessing the sequence of impacts from climate change through farm gross margins, land use, water quality and recreation, both at the individual and catchment scale. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Modelling and experimental validation of thin layer indirect solar drying of mango slices

    Energy Technology Data Exchange (ETDEWEB)

    Dissa, A.O.; Bathiebo, J.; Kam, S.; Koulidiati, J. [Laboratoire de Physique et de Chimie de l' Environnement (LPCE), Unite de Formation et de Recherche en Sciences Exactes et Appliquee (UFR/SEA), Universite de Ouagadougou, Avenue Charles de Gaulle, BP 7021 Kadiogo (Burkina Faso); Savadogo, P.W. [Laboratoire Sol Eau Plante, Institut de l' Environnement et de Recherches Agricoles, 01 BP 476, Ouagadougou (Burkina Faso); Desmorieux, H. [Laboratoire d' Automatisme et de Genie des Procedes (LAGEP), UCBL1-CNRS UMR 5007-CPE Lyon, Bat.308G, 43 bd du 11 Nov. 1918 Villeurbanne, Universite Claude Bernard Lyon1, Lyon (France)

    2009-04-15

    The thin layer solar drying of mango slices of 8 mm thick was simulated and experimented using a solar dryer designed and constructed in laboratory. Under meteorological conditions of harvest period of mangoes, the results showed that 3 'typical days' of drying were necessary to reach the range of preservation water contents. During these 3 days of solar drying, 50%, 40% and 5% of unbound water were eliminated, respectively, at the first, second and the third day. The final water content obtained was about 16 {+-} 1.33% d.b. (13.79% w.b.). This final water content and the corresponding water activity (0.6 {+-} 0.02) were in accordance with previous work. The drying rates with correction for shrinkage and the critical water content were experimentally determined. The critical water content was close to 70% of the initial water content and the drying rates were reduced almost at 6% of their maximum value at night. The thin layer drying model made it possible to simulate suitably the solar drying kinetics of mango slices with a correlation coefficient of r{sup 2} = 0.990. This study thus contributed to the setting of solar drying time of mango and to the establishment of solar drying rates' curves of this fruit. (author)

  14. Exploring the cooperative regimes in an agent-based model: indirect reciprocity vs. selfish incentives

    Science.gov (United States)

    Fort, H.

    2003-08-01

    The self-organization in cooperative regimes in a simple mean-field version of a model based on “selfish” agents which play the Prisoner's Dilemma (PD) game is studied. The agents have no memory and use strategies not based on direct reciprocity nor “tags”. Two variables are assigned to each agent k at time t, measuring its capital C( k; t) and its probability of cooperation p( k; t). At each time step t a pair of agents interact by playing the PD game. These two agents update their probability of cooperation p( k; t) as follows: they compare the profits they made in this interaction δC( k; t) with an estimator ε( k; t) and, if δC( k; t)⩾ ε( k; t), agent i increases its p( k; t) while if δC( k; t)punishment)-are analyzed. It turns out that for all these 24 possibilities, after a transient, the system self-organizes into a stationary state with average equilibrium probability of cooperation p¯∞= constant>0 . Depending on the payoff matrix, there are different equilibrium states characterized by their average probability of cooperation and average equilibrium per capita income ( p¯∞, δC¯∞) .

  15. Socioeconomic inequality in health in the British household panel: Tests of the social causation, health selection and the indirect selection hypothesis using dynamic fixed effects panel models.

    Science.gov (United States)

    Foverskov, Else; Holm, Anders

    2016-02-01

    Despite social inequality in health being well documented, it is still debated which causal mechanism best explains the negative association between socioeconomic position (SEP) and health. This paper is concerned with testing the explanatory power of three widely proposed causal explanations for social inequality in health in adulthood: the social causation hypothesis (SEP determines health), the health selection hypothesis (health determines SEP) and the indirect selection hypothesis (no causal relationship). We employ dynamic data of respondents aged 30 to 60 from the last nine waves of the British Household Panel Survey. Household income and location on the Cambridge Scale is included as measures of different dimensions of SEP and health is measured as a latent factor score. The causal hypotheses are tested using a time-based Granger approach by estimating dynamic fixed effects panel regression models following the method suggested by Anderson and Hsiao. We propose using this method to estimate the associations over time since it allows one to control for all unobserved time-invariant factors and hence lower the chances of biased estimates due to unobserved heterogeneity. The results showed no proof of the social causation hypothesis over a one to five year period and limited support for the health selection hypothesis was seen only for men in relation to HH income. These findings were robust in multiple sensitivity analysis. We conclude that the indirect selection hypothesis may be the most important in explaining social inequality in health in adulthood, indicating that the well-known cross-sectional correlations between health and SEP in adulthood seem not to be driven by a causal relationship, but instead by dynamics and influences in place before the respondents turn 30 years old that affect both their health and SEP onwards. The conclusion is limited in that we do not consider the effect of specific diseases and causal relationships in adulthood may be

  16. Indirect Control and Power

    Directory of Open Access Journals (Sweden)

    Cesarino Bertini

    2016-01-01

    Full Text Available To determine who has the power within a stock corporate company can be a quite complex problem, especially when control is achieved through alliances between shareholders. This problem arises especially in cases of indirect control of corporations, that is, in situations involving shareholders and companies with cross-shareholdings. The first to solve the problem of measuring power in the case of indirect share control were Gianfranco Gambarelli and Guillermo Owen in [10]. In the following years, numerous other models were introduced. In this paper, we critically examine the models of: Gambarelli and Owen, Denti and Prati, Crama and Leruth, Karos and Peters, as well as Mercik and Lobos, taking into account two well-known, illustrative examples, one with an acyclic corporate structure and the other with a cyclic structure. (original abstract

  17. Indirect effects of positive emotions on depressive symptoms in patients with schizophrenia%精神分裂症患者积极情绪对抑郁症状的间接作用

    Institute of Scientific and Technical Information of China (English)

    刘林林; 江源; 王川; 杨业兵; 陈清刚; 龙鲸

    2014-01-01

    . Negative coping styles was only correlated with depression(r= -0. 20,P﹤0. 05). Using the model of indirect effect( repeating line regression model),posi-tive coping styles and social support were identified as direct predictors of depression in schizophrenia(β = -0. 29,-0. 24,P ﹤0. 05),and positive mood was not a direct predictor of depression(β= -0. 13,P﹥0. 05). Conclusion This study shows that positive coping styles and social support could be completely mediators between positive emotions and depression in schizophrenia,indicating that positive emotions may have a significant indirect effect on depression by positive coping styles and social support.

  18. Modeling And Position Control Of Scara Type 3D Printer

    Directory of Open Access Journals (Sweden)

    Ahmet Saygamp305n Ogulmuamp351

    2015-08-01

    Full Text Available In this work a scara robot type 3D printer system is dynamically modeled and position control of the system is realized. For this aim computer aided design model of three degrees of freedom robotic system is created using SolidWorks program then obtained model is exported to MATLABSimMechanics software for position control. Also mathematical model of servo motors used in robotic 3D printer system is included in control methodology to design proportional controllers. Uncontrolled and controlled position results are simulated and given in the form of the graphics.

  19. Positioning models and systems based on digital television broadcasting signals

    Institute of Scientific and Technical Information of China (English)

    HE Feng; WU Lenan

    2007-01-01

    The requirement and feasibility of the positioning system using digital television(DTV)broadcasting signals are analyzed.The principle of DTV positioning on the basis of frame synchronization is brought forward and the ranging characteristic is studied that the observables are asynchronously measured during the same epoch interval.The models of the pseudo-range observation and Doppler carrier phase integral are researched.The system observation and state equations are presented on the basis of the above models.The simulation results showed that DTV positioning technology could remarkably improve the precision of system state estimates using smoothing methods for positioning systems or integrated navigation systems.The DTV positioning that has a sub-meter level ranging error and meter level positioning accuracy can parallel with and even taken as a beneficial substitute for the tradition positioning technology.

  20. Development of a caregiver empowerment model to promote positive outcomes.

    Science.gov (United States)

    Jones, Patricia S; Winslow, Betty W; Lee, Jerry W; Burns, Margaret; Zhang, Xinwei Esther

    2011-02-01

    Family members caring for aging parents experience both negative and positive outcomes from providing care. Theoretical explanations for negative outcomes have been developed. There is need for models that explain and predict positive outcomes. This article describes the evolution of the Caregiver Empowerment Model (CEM) to explain and predict positive outcomes of family caregiving. Although empirical findings support positive outcomes of family caregiving, less attention has been given to theoretical rationale for positive effects. The CEM predicts that, in the presence of filial values and certain background variables, caregiving demands are appraised as challenges instead of stressors. Appraising caregiving demands as a challenge, finding meaning, and using certain types of coping strategies are posited to be associated with growth and well-being. The CEM extends our understanding of the complexity of the caregiving experience, and can serve as a framework to guide in developing and testing theory-based interventions to promote positive outcomes.

  1. Plant trait-based models identify direct and indirect effects of climate change on bundles of grassland ecosystem services.

    Science.gov (United States)

    Lamarque, Pénélope; Lavorel, Sandra; Mouchet, Maud; Quétier, Fabien

    2014-09-23

    Land use and climate change are primary causes of changes in the supply of ecosystem services (ESs). Although the consequences of climate change on ecosystem properties and associated services are well documented, the cascading impacts of climate change on ESs through changes in land use are largely overlooked. We present a trait-based framework based on an empirical model to elucidate how climate change affects tradeoffs among ESs. Using alternative scenarios for mountain grasslands, we predicted how direct effects of climate change on ecosystems and indirect effects through farmers' adaptations are likely to affect ES bundles through changes in plant functional properties. ES supply was overall more sensitive to climate than to induced management change, and ES bundles remained stable across scenarios. These responses largely reflected the restricted extent of management change in this constrained system, which was incorporated when scaling up plot level climate and management effects on ecosystem properties to the entire landscape. The trait-based approach revealed how the combination of common driving traits and common responses to changed fertility determined interactions and tradeoffs among ESs.

  2. Incorporation of advanced aerosol activation treatments into CESM/CAM5: model evaluation and impacts on aerosol indirect effects

    Science.gov (United States)

    Gantt, B.; He, J.; Zhang, X.; Zhang, Y.; Nenes, A.

    2014-07-01

    One of the greatest sources of uncertainty in the science of anthropogenic climate change is from aerosol-cloud interactions. The activation of aerosols into cloud droplets is a direct microphysical linkage between aerosols and clouds; parameterizations of this process link aerosol with cloud condensation nuclei (CCN) and the resulting indirect effects. Small differences between parameterizations can have a large impact on the spatiotemporal distributions of activated aerosols and the resulting cloud properties. In this work, we incorporate a series of aerosol activation schemes into the Community Atmosphere Model version 5.1.1 within the Community Earth System Model version 1.0.5 (CESM/CAM5) which include factors such as insoluble aerosol adsorption and giant cloud condensation nuclei (CCN) activation kinetics to understand their individual impacts on global-scale cloud droplet number concentration (CDNC). Compared to the existing activation scheme in CESM/CAM5, this series of activation schemes increase the computation time by ~10% but leads to predicted CDNC in better agreement with satellite-derived/in situ values in many regions with high CDNC but in worse agreement for some regions with low CDNC. Large percentage changes in predicted CDNC occur over desert and oceanic regions, owing to the enhanced activation of dust from insoluble aerosol adsorption and reduced activation of sea spray aerosol after accounting for giant CCN activation kinetics. Comparison of CESM/CAM5 predictions against satellite-derived cloud optical thickness and liquid water path shows that the updated activation schemes generally improve the low biases. Globally, the incorporation of all updated schemes leads to an average increase in column CDNC of 150% and an increase (more negative) in shortwave cloud forcing of 12%. With the improvement of model-predicted CDNCs and better agreement with most satellite-derived cloud properties in many regions, the inclusion of these aerosol activation

  3. Shape parameter estimate for a glottal model without time position

    OpenAIRE

    Degottex, Gilles; Roebel, Axel; Rodet, Xavier

    2009-01-01

    cote interne IRCAM: Degottex09a; None / None; National audience; From a recorded speech signal, we propose to estimate a shape parameter of a glottal model without estimating his time position. Indeed, the literature usually propose to estimate the time position first (ex. by detecting Glottal Closure Instants). The vocal-tract filter estimate is expressed as a minimum-phase envelope estimation after removing the glottal model and a standard lips radiation model. Since this filter is mainly b...

  4. Fourier-positivity constraints on QCD dipole models

    Directory of Open Access Journals (Sweden)

    Bertrand G. Giraud

    2016-09-01

    Full Text Available Fourier-positivity (F-positivity, i.e. the mathematical property that a function has a positive Fourier transform, can be used as a constraint on the parametrization of QCD dipole-target cross-sections or Wilson line correlators in transverse position space r. They are Bessel transforms of positive transverse momentum dependent gluon distributions. Using mathematical F-positivity constraints on the limit r→0 behavior of the dipole amplitudes, we identify the common origin of the violation of F-positivity for various, however phenomenologically convenient, dipole models. It is due to the behavior r2+ϵ, ϵ>0 softer, even slightly, than color transparency. F-positivity seems thus to conflict with the present dipole formalism when it includes a QCD running coupling constant α(r.

  5. Indirect Comorbidity in Childhood and Adolescence

    Directory of Open Access Journals (Sweden)

    William eCopeland

    2013-11-01

    Full Text Available Objective: Comorbidity between psychiatric disorders is common, but pairwise associations between two disorders may be explained by the presence of other diagnoses that are associated with both disorders or indirect comorbidity. Method: Comorbidities of common childhood psychiatric disorders were tested in three community samples of children ages 6 to 17 (8931 observations of 2965 subjects. Psychiatric disorder status in all three samples was assessed with the Child and Adolescent Psychiatric Assessment. Indirect comorbidity was defined as A-B associations that decreased from significance to nonsignificance after adjusting for other disorders. Results: All tested childhood psychiatric disorders were positively associated in bivariate analyses. After adjusting for comorbidities, many ssociations involving a behavioral disorder and an emotional disorder were attenuated suggesting indirect comorbidity. Generalized anxiety and depressive disorders displayed a very high level of overlap (adjusted OR=37.9. All analyses were rerun with depressive disorders grouped with generalized anxiety disorder in a single distress disorders category. In these revised models, all associations between and emotional disorder and a behavior disorder met our criteria for indirect comorbidity except for the association of oppositional defiant disorder with distress disorders (OR=11.3. Follow-up analyses suggested that the indirect associations were primarily accounted for by oppositional defiant disorder and the distress disorder category. There was little evidence of either sex differences or differences by developmental period Conclusions: After accounting for the overlap between depressive disorders with generalized anxiety disorder, direct comorbidity between emotional and behavioral disorders was uncommon. When there was evidence of indirect comorbidity, ODD and distress disorders were the key intermediary diagnoses accounting for the apparent associations.

  6. Modelling of tubular-designed solid oxide fuel cell with indirect internal reforming operation fed by different primary fuels

    Science.gov (United States)

    Dokmaingam, P.; Assabumrungrat, S.; Soottitantawat, A.; Laosiripojana, N.

    Mathematical models of an indirect internal reforming solid oxide fuel cell (IIR-SOFC) fed by four different primary fuels, i.e., methane, biogas, methanol and ethanol, are developed based on steady-state, heterogeneous, two-dimensional and tubular-design SOFC models. The effect of fuel type on the thermal coupling between internal endothermic reforming with exothermic electrochemical reactions and system performance are determined. The simulation reveals that an IIR-SOFC fuelled by methanol provides the smoothest temperature gradient with high electrochemical efficiency. Furthermore, the content of CO 2 in biogas plays an important role on system performance since electrical efficiency is improved by the removal of some CO 2 from biogas but a larger temperature gradient is expected. Sensitivity analysis of three parameters, namely, a operating pressure, inlet steam to carbon (S:C) ratio and flow direction is then performed. By increasing the operating pressure up to 10 bar, the system efficiency increases and the temperature gradient can be minimized. The use of a high inlet S:C ratio reduces the cooling spot at the entrance of reformer channel but the electrical efficiency is considerably decreased. An IIR-SOFC with a counter-flow pattern (as based case) is compared with that with co-flow pattern (co-flow of air and fuel streams through fuel cell). The IIR-SOFC with co-flow pattern provides higher voltage and a smoother temperature gradient along the system due to superior matching between heat supplied from electrochemical reaction and heat required for steam reforming reaction; thus it is expected to be a better option for practical applications.

  7. A COLLABORATIVE LOCATION MODEL FOR CELLULAR MOBILE POSITION LOCATION

    Institute of Scientific and Technical Information of China (English)

    Deng Ping; Liu Lin; Fan Pingzhi

    2004-01-01

    In cellular network, several Time Difference Of Arrival (TDOA) location algorithms can be applied to mobile position estimation. However, each algorithm has its own limitations and none of them is proved to be the most reliable one in different channel environments. In this paper Kleine-Ostmann's data fusion model is modified and a collaborative location model which incorporates position estimate of two TDOA location algorithms is proposed.Analysis and simulation show that more reliable and accurate mobile position estimation can be achieved based on this model.

  8. A model for codon position bias in RNA editing

    CERN Document Server

    Liu, T; Liu, Tsunglin; Bundschuh, Ralf

    2005-01-01

    RNA editing can be crucial for the expression of genetic information via inserting, deleting, or substituting a few nucleotides at specific positions in an RNA sequence. Within coding regions in an RNA sequence, editing usually occurs with a certain bias in choosing the positions of the editing sites. In the mitochondrial genes of {\\it Physarum polycephalum}, many more editing events have been observed at the third codon position than at the first and second, while in some plant mitochondria the second codon position dominates. Here we propose an evolutionary model that explains this bias as the basis of selection at the protein level. The model predicts a distribution of the three positions rather close to the experimental observation in {\\it Physarum}. This suggests that the codon position bias in {\\it Physarum} is mainly a consequence of selection at the protein level.

  9. Stochastic magnetic measurement model for relative position and orientation estimation

    NARCIS (Netherlands)

    Schepers, H.M.; Veltink, P.H.

    2010-01-01

    This study presents a stochastic magnetic measurement model that can be used to estimate relative position and orientation. The model predicts the magnetic field generated by a single source coil at the location of the sensor. The model was used in a fusion filter that predicts the change of positio

  10. Stochastic magnetic measurement model for relative position and orientation estimation

    NARCIS (Netherlands)

    Schepers, H. Martin; Veltink, Petrus H.

    2010-01-01

    This study presents a stochastic magnetic measurement model that can be used to estimate relative position and orientation. The model predicts the magnetic field generated by a single source coil at the location of the sensor. The model was used in a fusion filter that predicts the change of positio

  11. A simplified indirect bonding technique

    Directory of Open Access Journals (Sweden)

    Radha Katiyar

    2014-01-01

    Full Text Available With the advent of lingual orthodontics, indirect bonding technique has become an integral part of practice. It involves placement of brackets initially on the models and then their transfer to teeth with the help of transfer trays. Problems encountered with current indirect bonding techniques used are (1 the possibility of adhesive flash remaining around the base of the brackets which requires removal (2 longer time required for the adhesive to gain enough bond strength for secure tray removal. The new simplified indirect bonding technique presented here overcomes both these problems.

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

    Institute of Scientific and Technical Information of China (English)

    Bin Chen

    2008-01-01

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

  13. An effective model for fermion dark matter. Indirect detection of supersymmetric dark matter in astronomy with the CELESTE Telescope; Modele effectif de matiere noire fermionique. Detection indirecte de matiere noir supersymetrique en astronomie avec le Telescope CELESTE

    Energy Technology Data Exchange (ETDEWEB)

    Lavalle, Julien [Ecole Doctorale des Sciences Fondamentales, Universite Blaise Pascal, Aubiere (France)

    2004-07-01

    The purpose of this thesis is to discuss both phenomenological and experimental aspects of Dark Matter, related to its indirect detection with gamma-ray astronomy. In the MSSM framework, neutralinos arise as natural candidates to non-baryonic and Cold Dark Matter, whose gravitational effects manifest in the Universe at different scales. As they are Majorana particles, they may in principle annihilate in high density regions, as the centres of galaxies, and produce gamma rays. Nevertheless, the expected fluxes are basically low compared to experimental sensitivities. After estimating gamma fluxes from M31 and Draco galaxies in the MSSM scheme, we first generalize the MSSM couplings by studying an effective Lagrangian. We show that the only constraint of imposing a relic abundance compatible with recent measurements obviously deplete significantly the gamma ray production, but also that predictions in this effective approach are more optimistic for indirect detection than the MSSM. In a second part, we present the indirect searches for Dark Matter performed with the CELESTE Cherenkov telescope towards the galaxy M31. We propose a statistical method to reconstruct spectra, mandatory to discriminate classical and exotic spectra. The M31 data analysis enables the extraction of an upper limit on the gamma ray flux, which is the first worldwide for a galaxy in the energy range 50-500 GeV, and whose astrophysical interest goes beyond indirect searches for Dark Matter. (author)

  14. Indirect decompression and vertebral body endplate strength after lateral interbody spacer impaction: cadaveric and foam-block models.

    Science.gov (United States)

    Kwon, Anthony J; Hunter, William D; Moldavsky, Mark; Salloum, Kanaan; Bucklen, Brandon

    2016-05-01

    OBJECTIVE The lateral transpsoas approach to the lumbar spine is a well-defined procedure for the management of discogenic spinal pathology necessitating surgical intervention. Intervertebral device subsidence is a postoperative clinical risk that can lead to recurrence of symptomatic pathology and the need for surgical reintervention. The current study was designed to investigate static versus expandable lateral intervertebral spacers in indirect decompression for preserving vertebral body endplate strength. METHODS Using a cadaveric biomechanical study and a foam-block vertebral body model, researchers compared vertebral body endplate strength and distraction potential. Fourteen lumbar motion segments (7 L2-3 and 7 L4-5 specimens) were distributed evenly between static and expandable spacer groups. In each specimen discectomy was followed by trialing and spacer impaction. Motion segments were axially sectioned through the disc, and a metal stamp was used to apply a compressive load to superior and inferior vertebral bodies to quantify endplate strength. A paired, 2-sample for means t-test was performed to determine statistically significant differences between groups (p ≤ 0.05). A foam-block endplate model was used to control simulated disc tension when a spacer with 2- and 3-mm desired distraction was inserted. One-way ANOVA and a post hoc Student Newman-Keuls test were performed (p ≤ 0.05) to determine differences in distraction. RESULTS Both static and expandable spacers restored intact neural foramen and disc heights after device implantation (p > 0.05). Maximum peak loads at endplate failure for static and expandable spacers were 1764 N (± 966 N) and 2284 N (± 949 N), respectively (p ≤ 0.05). The expandable spacer consistently produced greater desired distraction than was created by the static spacer in the foam-block model (p ≤ 0.05). Distraction created by fully expanding the spacer was significantly greater than the predetermined goals of 2 mm

  15. From an indirect response pharmacodynamic model towards a secondary signal model of dose-response relationship between exercise training and physical performance

    Science.gov (United States)

    Busso, Thierry

    2017-01-01

    The aim of this study was to test the suitability of using indirect responses for modeling the effects of physical training on performance. We formulated four different models assuming that increase in performance results of the transformation of a signal secondary to the primary stimulus which is the training dose. The models were designed to be used with experimental data with daily training amounts ascribed to input and performance measured at several dates ascribed to output. The models were tested using data obtained from six subjects who trained on a cycle ergometer over a 15-week period. The data fit for each subject was good for all of the models. Goodness-of-fit and consistency of parameter estimates favored the model that took into account the inhibition of production of training effect. This model produced an inverted-U shape graphic when plotting daily training dose against performance because of the effect of one training session on the cumulated effects of previous sessions. In conclusion, using secondary signal-dependent response provided a framework helpful for modeling training effect which could enhance the quantitative methods used to analyze how best to dose physical activity for athletic performance or healthy living. PMID:28074875

  16. Mouse models of estrogen receptor-positive breast cancer

    Directory of Open Access Journals (Sweden)

    Shakur Mohibi

    2011-01-01

    Full Text Available Breast cancer is the most frequent malignancy and second leading cause of cancer-related deaths among women. Despite advances in genetic and biochemical analyses, the incidence of breast cancer and its associated mortality remain very high. About 60 - 70% of breast cancers are Estrogen Receptor alpha (ER-α positive and are dependent on estrogen for growth. Selective estrogen receptor modulators (SERMs have therefore provided an effective targeted therapy to treat ER-α positive breast cancer patients. Unfortunately, development of resistance to endocrine therapy is frequent and leads to cancer recurrence. Our understanding of molecular mechanisms involved in the development of ER-α positive tumors and their resistance to ER antagonists is currently limited due to lack of experimental models of ER-α positive breast cancer. In most mouse models of breast cancer, the tumors that form are typically ER-negative and independent of estrogen for their growth. However, in recent years more attention has been given to develop mouse models that develop different subtypes of breast cancers, including ER-positive tumors. In this review, we discuss the currently available mouse models that develop ER-α positive mammary tumors and their potential use to elucidate the molecular mechanisms of ER-α positive breast cancer development and endocrine resistance.

  17. Improved spring model-based collaborative indoor visible light positioning

    Science.gov (United States)

    Luo, Zhijie; Zhang, WeiNan; Zhou, GuoFu

    2016-06-01

    Gaining accuracy with indoor positioning of individuals is important as many location-based services rely on the user's current position to provide them with useful services. Many researchers have studied indoor positioning techniques based on WiFi and Bluetooth. However, they have disadvantages such as low accuracy or high cost. In this paper, we propose an indoor positioning system in which visible light radiated from light-emitting diodes is used to locate the position of receivers. Compared with existing methods using light-emitting diode light, we present a high-precision and simple implementation collaborative indoor visible light positioning system based on an improved spring model. We first estimate coordinate position information using the visible light positioning system, and then use the spring model to correct positioning errors. The system can be employed easily because it does not require additional sensors and the occlusion problem of visible light would be alleviated. We also describe simulation experiments, which confirm the feasibility of our proposed method.

  18. Initial studies in the modelling of position resolving cryogenic detectors

    CERN Document Server

    Ashby, J V; Greenough, C S

    2002-01-01

    In this paper, we describe some results in the modelling of a Cryogenic Detector. These detectors use the heat generated from an X-ray event to determine the event's time and position. The model makes the basic assumption that the heat transport can be represented through by linear diffusion process and that the times at which the temperature changes reach the edge sensors can be used to determine the position of the event. The paper develops a finite element model of the device and performs a series of numerical experiments. The results of these experiments are compared with a simple analytic model. Two methods of determining the event position are presented: one based on an analytic solution and a second using neural network.

  19. Predicting nucleosome positioning using a duration Hidden Markov Model

    Directory of Open Access Journals (Sweden)

    Widom Jonathan

    2010-06-01

    Full Text Available Abstract Background The nucleosome is the fundamental packing unit of DNAs in eukaryotic cells. Its detailed positioning on the genome is closely related to chromosome functions. Increasing evidence has shown that genomic DNA sequence itself is highly predictive of nucleosome positioning genome-wide. Therefore a fast software tool for predicting nucleosome positioning can help understanding how a genome's nucleosome organization may facilitate genome function. Results We present a duration Hidden Markov model for nucleosome positioning prediction by explicitly modeling the linker DNA length. The nucleosome and linker models trained from yeast data are re-scaled when making predictions for other species to adjust for differences in base composition. A software tool named NuPoP is developed in three formats for free download. Conclusions Simulation studies show that modeling the linker length distribution and utilizing a base composition re-scaling method both improve the prediction of nucleosome positioning regarding sensitivity and false discovery rate. NuPoP provides a user-friendly software tool for predicting the nucleosome occupancy and the most probable nucleosome positioning map for genomic sequences of any size. When compared with two existing methods, NuPoP shows improved performance in sensitivity.

  20. The Frequency of High-Risk Behaviors Among Iranian College Students Using Indirect Methods: Network Scale-Up and Crosswise Model

    Directory of Open Access Journals (Sweden)

    Kazemzadeh

    2016-07-01

    Full Text Available Background Since the direct questions usually underestimate the frequency of sensitive behaviors, indirect methods can be used to estimate the frequency of some risky behaviors such as illicit drug use, sexual behaviors especially where these behaviors are highly stigmatized. Objectives In the current study, we indirectly estimated the prevalence of some risky behaviors among college students using two indirect methods: network scale-up (NSU and crosswise model (CM. Patients and Methods Having recruited 563 students from one of Iran’s major medical universities, the prevalence of opium and drug use, alcohol consumption, relationships with the opposite sex (RWOS,and extra/pre-marital sex (EPMS were estimated using two indirect methods. Results The estimated prevalence using the CM and NSU were alcohol consumption (16.8% vs. 8.1%, opium use (2.2% both, methamphetamine use (7.2% vs. 1.2%, taking tramadol without medical indications (14.8% vs. 4.8%, RWOS (42.3% vs. 31.9%, and EPMS (12.4% vs. 7.1%. Conclusions Lower estimations in the NSU method might be due to the transmission barrier, which means that students were not fully aware of the high-risk behaviors of their close friends. Nonetheless, it seems that these risky behaviors were more or less common among Iranian college students.

  1. Modelling and control of neutron and synchrotron beamline positioning systems

    Science.gov (United States)

    Nneji, S. O.; Zhang, S. Y.; Kabra, S.; Moat, R. J.; James, J. A.

    2016-03-01

    Measurement of residual stress using neutron or synchrotron diffraction relies on the accurate alignment of the sample in relation to the gauge volume of the instrument. Automatic sample alignment can be achieved using kinematic models of the positioning system provided the relevant kinematic parameters are known, or can be determined, to a suitable accuracy. In this paper, the use of techniques from robotic calibration theory to generate kinematic models of both off-the-shelf and custom-built positioning systems is demonstrated. The approach is illustrated using a positioning system in use on the ENGIN-X instrument at the UK's ISIS pulsed neutron source comprising a traditional XYZΩ table augmented with a triple axis manipulator. Accuracies better than 100 microns were achieved for this compound system. Discussed here in terms of sample positioning systems these methods are entirely applicable to other moving instrument components such as beam shaping jaws and detectors.

  2. Modelling and control of neutron and synchrotron beamline positioning systems

    Energy Technology Data Exchange (ETDEWEB)

    Nneji, S.O., E-mail: Stephen.nneji@open.ac.uk [The Open University, Materials Engineering, Walton Hall, Milton Keynes, Buckinghamshire MK7 6AA (United Kingdom); Science and Technology Facility Council , Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, OX110QX Oxfordshire (United Kingdom); Zhang, S.Y.; Kabra, S. [Science and Technology Facility Council , Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, OX110QX Oxfordshire (United Kingdom); Moat, R.J.; James, J.A. [The Open University, Materials Engineering, Walton Hall, Milton Keynes, Buckinghamshire MK7 6AA (United Kingdom)

    2016-03-21

    Measurement of residual stress using neutron or synchrotron diffraction relies on the accurate alignment of the sample in relation to the gauge volume of the instrument. Automatic sample alignment can be achieved using kinematic models of the positioning system provided the relevant kinematic parameters are known, or can be determined, to a suitable accuracy. In this paper, the use of techniques from robotic calibration theory to generate kinematic models of both off-the-shelf and custom-built positioning systems is demonstrated. The approach is illustrated using a positioning system in use on the ENGIN-X instrument at the UK's ISIS pulsed neutron source comprising a traditional XYZΩ table augmented with a triple axis manipulator. Accuracies better than 100 microns were achieved for this compound system. Discussed here in terms of sample positioning systems these methods are entirely applicable to other moving instrument components such as beam shaping jaws and detectors.

  3. Dark matter indirect detection signals and the nature of neutrinos in the supersymmetric $U(1)_{B-L}$ extension of the standard model

    CERN Document Server

    Allahverdi, Rouzbeh; Dutta, Bhaskar; Gao, Yu

    2014-01-01

    In this paper, we study the prospects for determining the nature of neutrinos in the context of a supersymmetric $B-L$ extension of the standard model by using dark matter indirect detection signals and bounds on $N_{\\text{eff}}$ from the cosmic microwave background data. The model contains two new dark matter candidates whose dominant annihilation channels produce more neutrinos than neutralino dark matter in the minimal supersymmetric standard model. The photon and neutrino counts may then be used to discriminate between the two models. If the dark matter comes from the B-L sector, its indirect signals and impact on the cosmic microwave background can shed light on the nature of the neutrinos. When the light neutrinos are of Majorana type, the indirect neutrino signal from the Sun and the galactic center may show a prompt neutrino box-feature, as well as an earlier cut-off in both neutrino and gamma ray energy spectra. When the light neutrinos are of Dirac type, their contribution to the effective number of...

  4. Positive Instruction in Music Studios: Introducing a New Model for Teaching Studio Music in Schools Based upon Positive Psychology

    OpenAIRE

    Patston, Tim; Waters, Lea

    2015-01-01

    This practice paper explores the intersection of school studio-music pedagogy and positive psychology in order to enhance students’ learning and engagement. The paper has a practitioner focus and puts forward a new model of studio teaching, the Positive Instruction in Music Studios (PIMS) model that guides teachers through four key positive psychology processes that can be used in a music lesson: positive priming, strengths spotting, positive pause, and process praise. The model provides a ne...

  5. Positive Instruction in Music Studios: Introducing a New Model for Teaching Studio Music in Schools Based upon Positive Psychology

    OpenAIRE

    Patston, Tim; Waters, Lea

    2015-01-01

    This practice paper explores the intersection of school studio-music pedagogy and positive psychology in order to enhance students? learning and engagement. The paper has a practitioner focus and puts forward a new model of studio teaching, the Positive Instruction in Music Studios (PIMS) model that guides teachers through four key positive psychology processes that can be used in a music lesson: positive priming, strengths spotting, positive pause, and process praise. The model provides a ne...

  6. Adjuvant cyclophosphamide, methotrexate, and fluorouracil in premonopausal patients with node-positive breast cancer: indirect comparison of dose and schedule in DBCG trials 77, 82, and 89

    DEFF Research Database (Denmark)

    Ejlertsen, B.; Mouridsen, H.T.; Jensen, M.B.

    2008-01-01

    A significant reduction in the risk of recurrence and death was achieved three decades ago with adjuvant chemotherapy in patients with operable breast. The major pivotal trials used oral cyclophosphamide (C) days 1-14 with intravenous methotrexate (M) and fluorouracil (F) on days 1 and 8, repeated...... Cancer Cooperative Group (DBCG), and two succeeding randomised trials in premenopausal patients with node positive breast cancer used three-weekly or four-weekly intravenous CMF in one of the treatment arms. RESULTS: Between November 1977 and January 2001 these trials included 2 213 patients who...... was performed adjusting for the known prognostic factors. In the adjusted analysis a 30% increase in the risk of recurrence was observed for two the intravenous regimens as compared to classical CMF. As concerns survival a significant 40% increase in the risk of death was observed with the four-weekly regimen...

  7. Advanced optical position sensors for magnetically suspended wind tunnel models

    Science.gov (United States)

    Lafleur, S.

    1985-01-01

    A major concern to aerodynamicists has been the corruption of wind tunnel test data by model support structures, such as stings or struts. A technique for magnetically suspending wind tunnel models was considered by Tournier and Laurenceau (1957) in order to overcome this problem. This technique is now implemented with the aid of a Large Magnetic Suspension and Balance System (LMSBS) and advanced position sensors for measuring model attitude and position within the test section. Two different optical position sensors are discussed, taking into account a device based on the use of linear CCD arrays, and a device utilizing area CID cameras. Current techniques in image processing have been employed to develop target tracking algorithms capable of subpixel resolution for the sensors. The algorithms are discussed in detail, and some preliminary test results are reported.

  8. Constraining the Influence of Natural Variability to Improve Estimates of Global Aerosol Indirect Effects in a Nudged Version of the Community Atmosphere Model 5

    Energy Technology Data Exchange (ETDEWEB)

    Kooperman, G. J.; Pritchard, M. S.; Ghan, Steven J.; Wang, Minghuai; Somerville, Richard C.; Russell, Lynn

    2012-12-11

    Natural modes of variability on many timescales influence aerosol particle distributions and cloud properties such that isolating statistically significant differences in cloud radiative forcing due to anthropogenic aerosol perturbations (indirect effects) typically requires integrating over long simulations. For state-of-the-art global climate models (GCM), especially those in which embedded cloud-resolving models replace conventional statistical parameterizations (i.e. multi-scale modeling framework, MMF), the required long integrations can be prohibitively expensive. Here an alternative approach is explored, which implements Newtonian relaxation (nudging) to constrain simulations with both pre-industrial and present-day aerosol emissions toward identical meteorological conditions, thus reducing differences in natural variability and dampening feedback responses in order to isolate radiative forcing. Ten-year GCM simulations with nudging provide a more stable estimate of the global-annual mean aerosol indirect radiative forcing than do conventional free-running simulations. The estimates have mean values and 95% confidence intervals of -1.54 ± 0.02 W/m2 and -1.63 ± 0.17 W/m2 for nudged and free-running simulations, respectively. Nudging also substantially increases the fraction of the world’s area in which a statistically significant aerosol indirect effect can be detected (68% and 25% of the Earth's surface for nudged and free-running simulations, respectively). One-year MMF simulations with and without nudging provide global-annual mean aerosol indirect radiative forcing estimates of -0.80 W/m2 and -0.56 W/m2, respectively. The one-year nudged results compare well with previous estimates from three-year free-running simulations (-0.77 W/m2), which showed the aerosol-cloud relationship to be in better agreement with observations and high-resolution models than in the results obtained with conventional parameterizations.

  9. The indirect association of job strain with long-term sickness absence through bullying: a mediation analysis using structural equation modeling

    OpenAIRE

    Janssens, Heidi; Braeckman, Lutgart; De Clercq, Bart; Casini, Annalisa; De Bacquer, Dirk; Kittel, France; Clays, Els

    2016-01-01

    Background: In this longitudinal study the complex interplay between both job strain and bullying in relation to sickness absence was investigated. Following the "work environment hypothesis", which establishes several work characteristics as antecedents of bullying, we assumed that job strain, conceptualized by the Job-Demand-Control model, has an indirect relation with long-term sickness absence through bullying. Methods: The sample consisted of 2983 Belgian workers, aged 30 to 55 years...

  10. Indirect immunofluorescence test performance and questionnaire results from the Centers for Disease Control Model Performance Evaluation Program for human immunodeficiency virus type 1 testing.

    OpenAIRE

    Taylor, R N; Hearn, T L; Schalla, W O; Valdiserri, R O

    1990-01-01

    Results from laboratories performing indirect immunofluorescence (IIF) testing for human immunodeficiency virus type 1 antibody and participating in the Centers for Disease Control Model Performance Evaluation Program in 1988 are presented. Approximately 90% of all laboratories receiving specimen panels or questionnaires furnished results to the Centers for Disease Control. In September 1988, 111 reports were received from IIF laboratories from 34 states and nine countries; most of these labo...

  11. Comparing implicit and explicit semantic access of direct and indirect word pairs in schizophrenia to evaluate models of semantic memory.

    Science.gov (United States)

    Neill, Erica; Rossell, Susan Lee

    2013-02-28

    Semantic memory deficits in schizophrenia (SZ) are profound, yet there is no research comparing implicit and explicit semantic processing in the same participant sample. In the current study, both implicit and explicit priming are investigated using direct (LION-TIGER) and indirect (LION-STRIPES; where tiger is not displayed) stimuli comparing SZ to healthy controls. Based on a substantive review (Rossell and Stefanovic, 2007) and meta-analysis (Pomarol-Clotet et al., 2008), it was predicted that SZ would be associated with increased indirect priming implicitly. Further, it was predicted that SZ would be associated with abnormal indirect priming explicitly, replicating earlier work (Assaf et al., 2006). No specific hypotheses were made for implicit direct priming due to the heterogeneity of the literature. It was hypothesised that explicit direct priming would be intact based on the structured nature of this task. The pattern of results suggests (1) intact reaction time (RT) and error performance implicitly in the face of abnormal direct priming and (2) impaired RT and error performance explicitly. This pattern confirms general findings regarding implicit/explicit memory impairments in SZ whilst highlighting the unique pattern of performance specific to semantic priming. Finally, priming performance is discussed in relation to thought disorder and length of illness.

  12. Design of Indirect Rotor-Position Detecting Control System for Switched Reluctance Motor%开关磁阻电动机间接位置检测控制系统设计

    Institute of Scientific and Technical Information of China (English)

    张青春

    2011-01-01

    On the basis of expounding the principle of simplified flux method with energy optimizing,a indirect rotor-position detecting control system of switched reluctance motor based on the simplified flux method with energy optimizing was designed. The current and speed double closed loop control system was adopted. The implementation schemes of the indirect position detecting of energy optimizing flux,the current closed loop control and the speed closed loop control were given. The experiment system of the indirect rotor-position detecting control system of switched reluctance motor based on the simplified flux method with energy optimizing was built. The performances of the system were tested and analyzed. The test results show that the designed system can detect the control signals. And the expected phase current waveforms were obtained by the control system. It is developed as the approach foundation for the design of excellent performance SRD control system.%在阐述能量优化简化磁链法原理的基础上,设计了一种基于能量优化简化磁链法的开关磁阻电动机间接位置检测控制系统.系统采用电流、转速双闭环控制,给出了能量优化磁链间接位置检测、电流环控制和转速环控制的实现方案,构建了基于能量优化简化磁链法的开关磁阻电机间接位置检测控制实验系统,并对系统进行了实验测试和分析.实验结果表明,所设计系统能够准确检测控制系统所需控制信号,并通过控制系统获得了期望的相电流波形,为设计性能优良的开关磁阻电动机调速驱动系统提供了研究基础.

  13. The logic of indirect speech.

    Science.gov (United States)

    Pinker, Steven; Nowak, Martin A; Lee, James J

    2008-01-22

    When people speak, they often insinuate their intent indirectly rather than stating it as a bald proposition. Examples include sexual come-ons, veiled threats, polite requests, and concealed bribes. We propose a three-part theory of indirect speech, based on the idea that human communication involves a mixture of cooperation and conflict. First, indirect requests allow for plausible deniability, in which a cooperative listener can accept the request, but an uncooperative one cannot react adversarially to it. This intuition is supported by a game-theoretic model that predicts the costs and benefits to a speaker of direct and indirect requests. Second, language has two functions: to convey information and to negotiate the type of relationship holding between speaker and hearer (in particular, dominance, communality, or reciprocity). The emotional costs of a mismatch in the assumed relationship type can create a need for plausible deniability and, thereby, select for indirectness even when there are no tangible costs. Third, people perceive language as a digital medium, which allows a sentence to generate common knowledge, to propagate a message with high fidelity, and to serve as a reference point in coordination games. This feature makes an indirect request qualitatively different from a direct one even when the speaker and listener can infer each other's intentions with high confidence.

  14. The logic of indirect speech

    Science.gov (United States)

    Pinker, Steven; Nowak, Martin A.; Lee, James J.

    2008-01-01

    When people speak, they often insinuate their intent indirectly rather than stating it as a bald proposition. Examples include sexual come-ons, veiled threats, polite requests, and concealed bribes. We propose a three-part theory of indirect speech, based on the idea that human communication involves a mixture of cooperation and conflict. First, indirect requests allow for plausible deniability, in which a cooperative listener can accept the request, but an uncooperative one cannot react adversarially to it. This intuition is supported by a game-theoretic model that predicts the costs and benefits to a speaker of direct and indirect requests. Second, language has two functions: to convey information and to negotiate the type of relationship holding between speaker and hearer (in particular, dominance, communality, or reciprocity). The emotional costs of a mismatch in the assumed relationship type can create a need for plausible deniability and, thereby, select for indirectness even when there are no tangible costs. Third, people perceive language as a digital medium, which allows a sentence to generate common knowledge, to propagate a message with high fidelity, and to serve as a reference point in coordination games. This feature makes an indirect request qualitatively different from a direct one even when the speaker and listener can infer each other's intentions with high confidence. PMID:18199841

  15. Liquidity Risk Management in Emerging Economies: A Parametric Value-at-Risk (VaR) model with Indirect Calibration and an Application to the Bolivian Financial System

    OpenAIRE

    Gonzales-Martínez, Rolando

    2009-01-01

    Time series of obligations with the public are important to liquidity risk management in emerging economies, but a traditional parametric VaR model could give imprecise measures of liquidity risk if the series do not approach a normal (Gaussian) distribution. To overcome this flaw of parametric gaussian VaR models, this study suggest a parametric VaR model with indirect calibration (VaR-i) with a beta-parameter calibrated to be successful in backtesting tests, according to the empirical distr...

  16. Modeling Positive Behavior Interventions and Supports for Preservice Teachers

    Science.gov (United States)

    Hill, Doris Adams; Flores, Margaret M.

    2014-01-01

    The authors modeled programwide positive behavior interventions and supports (PBIS) principles to 26 preservice teachers during consolidated yearly extended school year (ESY) services delivered to elementary students from four school districts. While PBIS were in place for preservice teachers to implement with students, a similar system was…

  17. Using Conceptual Change Theories to Model Position Concepts in Astronomy

    Science.gov (United States)

    Yang, Chih-Chiang; Hung, Jeng-Fung

    2012-01-01

    The roles of conceptual change and model building in science education are very important and have a profound and wide effect on teaching science. This study examines the change in children's position concepts after instruction, based on different conceptual change theories. Three classes were chosen and divided into three groups, including a…

  18. Particle based 3D modeling of positive streamer inception

    NARCIS (Netherlands)

    Teunissen, H.J.

    2012-01-01

    In this report we present a particle based 3D model for the study of streamer inception near positive electrodes in air. The particle code is of the PIC-MCC type and an electrode is included using the charge simulation method. An algorithm for the adaptive creation of super-particles is introduced,

  19. Development of an RTK-GPS Positioning Application with an Improved Position Error Model for Smartphones

    Directory of Open Access Journals (Sweden)

    Dongha Lee

    2012-09-01

    Full Text Available This study developed a smartphone application that provides wireless communication, NRTIP client, and RTK processing features, and which can simplify the Network RTK-GPS system while reducing the required cost. A determination method for an error model in Network RTK measurements was proposed, considering both random and autocorrelation errors, to accurately calculate the coordinates measured by the application using state estimation filters. The performance evaluation of the developed application showed that it could perform high-precision real-time positioning, within several centimeters of error range at a frequency of 20 Hz. A Kalman Filter was applied to the coordinates measured from the application, to evaluate the appropriateness of the determination method for an error model, as proposed in this study. The results were more accurate, compared with those of the existing error model, which only considered the random error.

  20. Development of an RTK-GPS positioning application with an improved position error model for smartphones.

    Science.gov (United States)

    Hwang, Jinsang; Yun, Hongsik; Suh, Yongcheol; Cho, Jeongho; Lee, Dongha

    2012-09-25

    This study developed a smartphone application that provides wireless communication, NRTIP client, and RTK processing features, and which can simplify the Network RTK-GPS system while reducing the required cost. A determination method for an error model in Network RTK measurements was proposed, considering both random and autocorrelation errors, to accurately calculate the coordinates measured by the application using state estimation filters. The performance evaluation of the developed application showed that it could perform high-precision real-time positioning, within several centimeters of error range at a frequency of 20 Hz. A Kalman Filter was applied to the coordinates measured from the application, to evaluate the appropriateness of the determination method for an error model, as proposed in this study. The results were more accurate, compared with those of the existing error model, which only considered the random error.

  1. Constraining the influence of natural variability to improve estimates of global aerosol indirect effects in a nudged version of the Community Atmosphere Model 5

    Science.gov (United States)

    Kooperman, G. J.; Pritchard, M. S.; Ghan, S. J.; Wang, M.; Somerville, R. C.; Russell, L. M.

    2012-12-01

    The newest version of NCAR's Community Atmosphere Model (CAM5) produces a strong global mean aerosol indirect effect of -1.54 W/m2. However, when CAM5 is modified to include resolved scale convective processes in a new multi-scale modeling framework (MMF) the indirect aerosol forcing is reduced by almost half (-0.80 W/m2). In the MMF approach, conventional cloud parameterizations are replaced by embedded cloud-resolving models (CRM) in each grid column of CAM5, and aerosol on the global grid is linked to explicitly resolved CRM scale relative humidity and updraft velocities to determine the number of aerosol particles that activate to form cloud droplets at CRM resolution. However, the increased computational expense incurred by resolving convective processes makes long integrations with the MMF prohibitively expensive. This is a challenge for investigating aerosol indirect effects because it typically requires integrating over long simulations to isolate statistically significant differences in cloud radiative forcing due to anthropogenic aerosol perturbations from natural variability. Here an alternative approach is explored, which implements Newtonian relaxation (nudging) to constrain simulations with both pre-industrial and present-day aerosol emissions toward identical meteorological conditions, thus reducing the influences of natural variability so that the two models can be compared in short simulations. Using this approach in CAM5, we find high pattern correlations between one-year averages of aerosol indirect effect and the pattern of the signal produced in a 100-year average. Estimates of aerosol indirect effects in CAM5 with and without nudging have mean values and 95% confidence intervals of -1.54 ± 0.02 W/m2 and -1.63 ± 0.17 W/m2, respectively. The approach is applied in the MMF to investigate the mechanisms responsible for producing a weaker forcing than CAM5. These include weaker responses in liquid water content and droplet number concentrations

  2. Positive Instruction in Music Studios: Introducing a New Model for Teaching Studio Music in Schools Based upon Positive Psychology.

    Science.gov (United States)

    Patston, Tim; Waters, Lea

    This practice paper explores the intersection of school studio-music pedagogy and positive psychology in order to enhance students' learning and engagement. The paper has a practitioner focus and puts forward a new model of studio teaching, the Positive Instruction in Music Studios (PIMS) model that guides teachers through four key positive psychology processes that can be used in a music lesson: positive priming, strengths spotting, positive pause, and process praise. The model provides a new, positively oriented approach to studio-music pedagogy that can be integrated into specific methods-based programs to enhance student learning and engagement.

  3. Indirection and computer security.

    Energy Technology Data Exchange (ETDEWEB)

    Berg, Michael J.

    2011-09-01

    The discipline of computer science is built on indirection. David Wheeler famously said, 'All problems in computer science can be solved by another layer of indirection. But that usually will create another problem'. We propose that every computer security vulnerability is yet another problem created by the indirections in system designs and that focusing on the indirections involved is a better way to design, evaluate, and compare security solutions. We are not proposing that indirection be avoided when solving problems, but that understanding the relationships between indirections and vulnerabilities is key to securing computer systems. Using this perspective, we analyze common vulnerabilities that plague our computer systems, consider the effectiveness of currently available security solutions, and propose several new security solutions.

  4. Sensorless position estimator applied to nonlinear IPMC model

    Science.gov (United States)

    Bernat, Jakub; Kolota, Jakub

    2016-11-01

    This paper addresses the issue of estimating position for an ionic polymer metal composite (IPMC) known as electro active polymer (EAP). The key step is the construction of a sensorless mode considering only current feedback. This work takes into account nonlinearities caused by electrochemical effects in the material. Owing to the recent observer design technique, the authors obtained both Lyapunov function based estimation law as well as sliding mode observer. To accomplish the observer design, the IPMC model was identified through a series of experiments. The research comprises time domain measurements. The identification process was completed by means of geometric scaling of three test samples. In the proposed design, the estimated position accurately tracks the polymer position, which is illustrated by the experiments.

  5. Positive Orientation and the Five-Factor Model

    Directory of Open Access Journals (Sweden)

    Miciuk Łukasz Roland

    2016-04-01

    Full Text Available The aim of the present study was to investigate the relationship between positive orientation (PO defined as a basic predisposition to perceive and evaluate positive aspects of life, the future and oneself and the Five-Factor Model of personality (FFM. Hypotheses postulated positive correlations between PO and extraversion, conscientiousness, agreeableness and openness; a negative correlation was predicted between PO and neuroticism. Two hundred Polish students completed the following measures: SES (Self-Esteem Scale, Rosenberg, SWLS (The Satisfaction with Life Scale; Diener, Emmons, Larson & Griffin, LOT-R (The Life Orientation Test - Revised; Scheier, Carver & Bridges and NEOFFI (NEO Five Factor Inventory, Costa & McCrae. The results confirmed correlations between PO and extraversion, conscientiousness, and neuroticism; correlations with openness and agreeableness were not supported. According to canonical correlations, PO shows a clear affinity to the FFM.

  6. Positive explorers: modeling dynamic control in normal aging.

    Science.gov (United States)

    Glass, Brian D; Osman, Magda

    2017-01-01

    Situations in which there are multiple changes occurring all at once and which demand complex decisions to be made are common throughout life, but little is known about how normal aging influences performance on these types of scenarios. To determine performance differences associated with normal aging, we test older and younger adults in a dynamic control task. The task involves the control of a single output variable over time via multiple and uncertain input controls. The Single Limited Input, Dynamic Exploratory Responses (SLIDER) computational model, is implemented to determine the behavioral characteristics associated with normal aging in a dynamic control task. Model-based analysis demonstrates a unique performance signature profile associated with normal aging. Specifically, older adults exhibit a positivity effect in which they are more influenced by positively valenced feedback, congruent with previous research, as well as enhanced exploratory behavior.

  7. Modelling the contribution of short-range atmospheric and hydrological transfers to nitrogen fluxes, budgets and indirect emissions in rural landscapes

    Directory of Open Access Journals (Sweden)

    J.-L. Drouet

    2012-05-01

    Full Text Available Spatial interactions within a landscape may lead to large inputs of reactive nitrogen (Nr transferred from cultivated areas and farms to oligotrophic ecosystems and induce environmental threats such as acidification, nitric pollution or eutrophication of protected areas. The paper presents a new methodology to estimate Nr fluxes at the landscape scale by taking into account spatial interactions between landscape elements. This methodology includes estimates of indirect Nr emissions due to short-range atmospheric and hydrological transfers. We used the NitroScape model which integrates processes of Nr transformation and short-range transfer in a dynamic and spatially distributed way to simulate Nr fluxes and budgets at the landscape scale. Four configurations of NitroScape were implemented by taking into account or not the atmospheric, hydrological or both pathways of Nr transfer. We simulated Nr fluxes, especially direct and indirect Nr emissions, within a test landscape including pig farms, croplands and unmanaged ecosystems. Simulation results showed the ability of NitroScape to simulate patterns of Nr emissions and recapture for each landscape element and the whole landscape. NitroScape made it possible to quantify the contribution of both atmospheric and hydrological transfers to Nr fluxes, budgets and indirect Nr emissions. For instance, indirect N2O emissions were estimated at around 21% of the total N2O emissions. They varied within the landscape according to land use, meteorological and soil conditions as well as topography. This first attempt proved that the NitroScape model is a useful tool to estimate the effect of spatial interactions on Nr fluxes and budgets as well as indirect Nr emissions within landscapes. Our approach needs to be further tested by applying Nitro

  8. Positive Periodic Solutions of an Epidemic Model with Seasonality

    Directory of Open Access Journals (Sweden)

    Gui-Quan Sun

    2013-01-01

    Full Text Available An SEI autonomous model with logistic growth rate and its corresponding nonautonomous model are investigated. For the autonomous case, we give the attractive regions of equilibria and perform some numerical simulations. Basic demographic reproduction number Rd is obtained. Moreover, only the basic reproduction number R0 cannot ensure the existence of the positive equilibrium, which needs additional condition Rd>R1. For the nonautonomous case, by introducing the basic reproduction number defined by the spectral radius, we study the uniform persistence and extinction of the disease. The results show that for the periodic system the basic reproduction number is more accurate than the average reproduction number.

  9. Structural Dynamics Model Updating with Positive Definiteness and No Spillover

    Directory of Open Access Journals (Sweden)

    Yongxin Yuan

    2014-01-01

    Full Text Available Model updating is a common method to improve the correlation between structural dynamics models and measured data. In conducting the updating, it is desirable to match only the measured spectral data without tampering with the other unmeasured and unknown eigeninformation in the original model (if so, the model is said to be updated with no spillover and to maintain the positive definiteness of the coefficient matrices. In this paper, an efficient numerical method for updating mass and stiffness matrices simultaneously is presented. The method first updates the modal frequencies. Then, a method is presented to construct a transformation matrix and this matrix is used to correct the analytical eigenvectors so that the updated model is compatible with the measurement of the eigenvectors. The method can preserve both no spillover and the symmetric positive definiteness of the mass and stiffness matrices. The method is computationally efficient as neither iteration nor numerical optimization is required. The numerical example shows that the presented method is quite accurate and efficient.

  10. Radial structure of the constricted positive column: Modeling and experiment

    Science.gov (United States)

    Golubovskii, Yu.; Kalanov, D.; Maiorov, V.

    2017-08-01

    We present a detailed self-consistent model of a positive column in argon glow discharge at moderate pressures and currents. This model describes the discharge transition between diffuse and constricted states. The model includes an extensive set of plasma chemical reactions and equation for inhomogeneous gas heating. The nonequilibrium behavior of an electron distribution function is also considered. One of the main features of the model is an accurate treatment of radiation trapping by solving the Holstein-Biberman equation directly. Influence of the radiation trapping on macroscopic parameters of the constricted positive column is studied. We propose a method for solving a boundary-value problem, including particle and energy balance equations for electrons, ground state atoms, atomic and molecular ions, and excited species. Unlike traditional solution approaches for similar systems, the method provides continuous Z- and S-shaped characteristics of discharge parameters, describing hysteresis in transition between diffuse and constricted discharge regimes. Performed experiments include measurements of volt-ampere characteristics and spectroscopic study of radial density profiles of excited atoms by measuring line emission and absorption, and electrons by measuring bremsstrahlung intensity. The role of resonance radiation trapping in spatial redistribution of 1 s and 2 p states of argon is demonstrated. Results of modeling are compared to the experimental data.

  11. Assesment of the Indirect and Semi-Direct Aerosol-Effect During ISDAC Through Integrated Observational and Modeling Studies

    Energy Technology Data Exchange (ETDEWEB)

    Boybeyi, Zafer [George Mason Univ., Fairfax, VA (United States)

    2014-09-29

    The Department of Energy (DOE) awarded George Mason University (GMU) with a research project. This project started on June, 2009 and ended July 2014. Main objectives of this research project are; a) to assess the indirect and semi-direct aerosol effects on microphysical structure and radiative properties of Arctic clouds, b) to assess the impact of feedback between the aerosol-cloud interactions and atmospheric boundary layer (ABL) processes on the surface energy balance, c) to better understand and characterize the important unresolved microphysical processes, aerosol effects, and ABL processes and feedbacks, over meso-γ spatial (~1-2 km) and temporal scales (a few minutes to days), and d) to investigate the scale dependency of microphysical parameterizations and its effect on simulations.

  12. Comparison of direct and indirect radionuclide cystography

    Energy Technology Data Exchange (ETDEWEB)

    Bower, G.; Lovegrove, F.T.; Geijsel, H.; Van der Schaff, A.; Guelfi, G.

    1985-05-01

    Thirty children were studied using both direct (catheter) and indirect techniques of radionuclide cystography. Of 54 ureters able to be compared, six showed vesicoureteric reflux (VUR) on the direct study but were read as negative on the indirect cystogram, and five showed no reflux on the direct cystogram but were read as positive for VUR on the indirect study. Regarding ureters read as true positives on indirect study, if that ureter has ever shown reflux at any time, or if it drained a scarred kidney specificity was improved to 97% without changing the sensitivity. Concerns about the validity of indirect cystogram results and the ease of assessment and low radiation dose from the direct cystogram has made direct cystography our preferred technique.

  13. Indirect Speech Acts

    Institute of Scientific and Technical Information of China (English)

    李威

    2001-01-01

    Indirect speech acts are frequently used in verbal communication, the interpretation of them is of great importance in order to meet the demands of the development of students' communicative competence. This paper, therefore, intends to present Searle' s indirect speech acts and explore the way how indirect speech acts are interpreted in accordance with two influential theories. It consists of four parts. Part one gives a general introduction to the notion of speech acts theory. Part two makes an elaboration upon the conception of indirect speech act theory proposed by Searle and his supplement and development of illocutionary acts. Part three deals with the interpretation of indirect speech acts. Part four draws implication from the previous study and also serves as the conclusion of the dissertation.

  14. Indirect Kalman Filter in Mobile Robot Application

    Directory of Open Access Journals (Sweden)

    Surachai Panich

    2010-01-01

    Full Text Available Problem statement: The most successful applications of Kalman filtering are to linearize about some nominal trajectory in state space that does not depend on the measurement data. The resulting filter is usually referred to as simply a linearized Kalman filter. Approach: This study introduced mainly indirect Kalman filter to estimate robot’s position. A developed differential encoder system integrated accelerometer is experimental tested in square shape. Results: Experimental results confirmed that indirect Kalman filter improves the accuracy and confidence of position estimation. Conclusion: In summary, we concluded that indirect Kalman filter has good potential to reduce error of measurement data.

  15. Contrast visibility for indirect MR arthrography with different protein contents and agent relaxivities at different field strengths: An in vitro model

    Energy Technology Data Exchange (ETDEWEB)

    Nouh, M.R., E-mail: mragab73@yahoo.com [Department of Radiodiagnosis and Diagnostic Imaging, Faculty of Medicine, Alexandria University, 1 Kolya-El Teb St., Mahata El-Ramel, Alexandria (Egypt); Schweitzer, M.E., E-mail: mschweitzer@toh.on.ca [501 Smyth Module S-1, University of Ottawa, Ottawa, ON K1H 8L6 (Canada); Ragatte, Ravinder R., E-mail: Ravinder.regatte@nyumc.org [301 E17th Street, Department of Radiology, Hospital for Joint Disease, New York University, New York, NY 10003 (United States)

    2011-11-15

    . Gadoteridol is suggested on 3 T field indirect MR arthrograms. Protein had no positive effect on either SI or relaxivities in any joint model.

  16. Indirect bonding technique in orthodontics

    Directory of Open Access Journals (Sweden)

    Kübra Yıldırım

    2016-08-01

    Full Text Available ‘Direct Bonding Technique’ which allows the fixed orthodontic appliances to be directly bonded to teeth without using bands decreased the clinic time for bracket bonding and increased esthetics and oral hygiene during orthodontic treatment. However, mistakes in bracket positioning were observed due to decreased direct visual sight and access to posterior teeth. ‘Indirect Bonding Technique’ was developed for eliminating these problems. Initially, decreased bond strength, higher bond failure rate, periodontal tissue irritation, compromised oral hygiene and increased laboratory time were the main disadvantages of this technique when compared to direct bonding. The newly developed materials and modified techniques help to eliminate these negative consequences. Today, the brackets bonded with indirect technique have similar bond strength with brackets bonded directly. Moreover, indirect and direct bonding techniques have similar effects on periodontal tissues. However, indirect bonding technique requires more attention and precision in laboratory and clinical stage, and has higher cost. Orthodontist's preference between these two bonding techniques may differ according to time spent in laboratory and clinic, cost, patient comfort and personal opinion.

  17. The positive group affect spiral : a dynamic model of the emergence of positive affective similarity in work groups

    NARCIS (Netherlands)

    Walter, F.; Bruch, H.

    2008-01-01

    This conceptual paper seeks to clarify the process of the emergence of positive collective affect. Specifically, it develops a dynamic model of the emergence of positive affective similarity in work groups. It is suggested that positive group affective similarity and within-group relationship qualit

  18. The positive group affect spiral : a dynamic model of the emergence of positive affective similarity in work groups

    NARCIS (Netherlands)

    Walter, F.; Bruch, H.

    This conceptual paper seeks to clarify the process of the emergence of positive collective affect. Specifically, it develops a dynamic model of the emergence of positive affective similarity in work groups. It is suggested that positive group affective similarity and within-group relationship

  19. Three dimensional modeling of combustion process and emission formation in a low heat rejection indirect injection diesel engine

    Directory of Open Access Journals (Sweden)

    Jafarmadar S.

    2014-01-01

    Full Text Available Higher heat losses and brake specific fuel consumption (BSFC are major problems in an indirect injection (IDI diesel engine, which can be overcome by means of low heat rejection (LHR concept. This concept is based on the approach of insulating of piston and liner of main chamber in IDI engine. At the present work, the combustion process and emission formation in baseline and LHR engines are studied by a Computational Fluid Dynamics (CFD code at four different loads (25%, 50%, 75% and 100% in maximum torque engine speed 730rpm. The numerical results for the pressure in cylinder and emissions for baseline engine at full load operation are compared to the corresponding experimental data and show good agreement. The comparison of the results for two cases show that when the load increases from 25% to 100% in 25% steps, heat loss in LHR engine decrease 40.3%, 44.7%,44.6% and 45.2%, respectively. At full load operation in LHR engine, NOx and Soot emissions decrease 13.5% and 54.4%, respectively and engine efficiency increases 6.3% in comparison to baseline engine.

  20. Positive random fields for modeling material stiffness and compliance

    DEFF Research Database (Denmark)

    Hasofer, Abraham Michael; Ditlevsen, Ove Dalager; Tarp-Johansen, Niels Jacob

    1998-01-01

    with material properties modeled in terms of the considered random fields.The paper addsthe gamma field, the Fisher field, the beta field, and their reciprocal fields to the catalogue. These fields are all defined on the basis of sums of squares of independent standard Gaussian random variables.All the existing...... marginal moments and the correlation functions are obtained explicitly. Also an inverse Gaussian fieldis added to the catalogue. It is defined in terms of first passage times in correlated joint Brownian motions. Finally an n-dimensional random vector of positive components is defined such that it can...

  1. Complementary test of the dark matter self-interaction in dark U(1) model by direct and indirect dark matter detection

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Chian-Shu [Physics Division, National Center for Theoretical Sciences, No. 101, Section 2, Kuang-Fu Road, Hsinchu, Taiwan, 30010 R.O.C. (China); Department of Physics, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu, Taiwan, 30010 R.O.C. (China); Institute of Physics, Academia Sinica, 128 Sec. 2,Academia Rd., Nangang, Taipei, Taiwan, 11529 R.O.C. (China); Lin, Guey-Lin; Lin, Yen-Hsun [Institute of Physics, National Chiao Tung University,1001 University Road, Hsinchu, Taiwan, 300 R.O.C. (China)

    2016-01-07

    The halo dark matter (DM) can be captured by the Sun if its final velocity after the collision with a nucleus in the Sun is less than the escape velocity. We consider a selfinteracting dark matter (SIDM) model where U(1) gauge symmetry is introduced to account for the DM self-interaction. Such a model naturally leads to isospin violating DM-nucleon interaction, although isospin symmetric interaction is still allowed as a special case. We present the IceCube-PINGU 2σ sensitivity to the parameter range of the above model with 5 years of search for neutrino signature from DM annihilation in the Sun. This indirect detection complements the direct detection by probing those SIDM parameter ranges which are either the region for very small m{sub χ} or the region opened up due to isospin violations.

  2. Mechanical behavior of bulk direct composite versus block composite and lithium disilicate indirect Class II restorations by CAD-FEM modeling.

    Science.gov (United States)

    Ausiello, Pietro; Ciaramella, Stefano; Fabianelli, Andrea; Gloria, Antonio; Martorelli, Massimo; Lanzotti, Antonio; Watts, David C

    2017-06-01

    To study the influence of resin based and lithium disilicate materials on the stress and strain distributions in adhesive class II mesio-occlusal-distal (MOD) restorations using numerical finite element analysis (FEA). To investigate the materials combinations in the restored teeth during mastication and their ability to relieve stresses. One 3D model of a sound lower molar and three 3D class II MOD cavity models with 95° cavity-margin-angle shapes were modelled. Different material combinations were simulated: model A, with a 10μm thick resin bonding layer and a resin composite bulk filling material; model B, with a 70μm resin cement with an indirect CAD-CAM resin composite inlay; model C, with a 70μm thick resin cement with an indirect lithium disilicate machinable inlay. To simulate polymerization shrinkage effects in the adhesive layers and bulk fill composite, the thermal expansion approach was used. Shell elements were employed for representing the adhesive layers. 3D solid CTETRA elements with four grid points were employed for modelling the food bolus and tooth. Slide-type contact elements were used between the tooth surface and food. A vertical occlusal load of 600 N was applied, and nodal displacements on the bottom cutting surfaces were constrained in all directions. All the materials were assumed to be isotropic and elastic and a static linear analysis was performed. Displacements were different in models A, B and C. Polymerization shrinkage hardly affected model A and mastication only partially affected mechanical behavior. Shrinkage stress peaks were mainly located marginally along the enamel-restoration interface at occlusal and mesio-distal sites. However, at the internal dentinal walls, stress distributions were critical with the highest maximum stresses concentrated in the proximal boxes. In models B and C, shrinkage stress was only produced by the 70μm thick resin layer, but the magnitudes depended on the Young's modulus (E) of the inlay

  3. Position-sensitive transition edge sensor modeling and results

    Energy Technology Data Exchange (ETDEWEB)

    Hammock, Christina E-mail: chammock@milkyway.gsfc.nasa.gov; Figueroa-Feliciano, Enectali; Apodaca, Emmanuel; Bandler, Simon; Boyce, Kevin; Chervenak, Jay; Finkbeiner, Fred; Kelley, Richard; Lindeman, Mark; Porter, Scott; Saab, Tarek; Stahle, Caroline

    2004-03-11

    We report the latest design and experimental results for a Position-Sensitive Transition-Edge Sensor (PoST). The PoST is motivated by the desire to achieve a larger field-of-view without increasing the number of readout channels. A PoST consists of a one-dimensional array of X-ray absorbers connected on each end to a Transition Edge Sensor (TES). Position differentiation is achieved through a comparison of pulses between the two TESs and X-ray energy is inferred from a sum of the two signals. Optimizing such a device involves studying the available parameter space which includes device properties such as heat capacity and thermal conductivity as well as TES read-out circuitry parameters. We present results for different regimes of operation and the effects on energy resolution, throughput, and position differentiation. Results and implications from a non-linear model developed to study the saturation effects unique to PoSTs are also presented.

  4. Testing GNSS ionosphere models based on the position domain

    Science.gov (United States)

    Orus-Perez, Raul; Rovira, Adria

    2017-04-01

    As is well know, the ionosphere is one of the main contributors to the navigation error of single-frequency users. Currently, there are many models available for correcting the ionosphere delay. Thus, the different GNSS provide its own ionosphere corrections in the Signal-in-Space as for instance, NeQuick G for Galileo or Klobuchar for GPS. Other sources for ionosphere corrections are the Satellite Based Augmentation Systems (i.e. EGNOS or WAAS), Global Ionospheric Maps (i.e. provided by IGS), regional maps and even climatological models, like NeQuick or IRI. With this large variety of models, there have been a lot of efforts to define a suitable strategy to test the accuracy of the different models. Usually, this testing has been done by computing a "reference ionosphere", using all kind of GNSS techniques, using ionosonde data or using altimeter data. These techniques are not bias free and they may raise questions on which is the absolute accuracy they achieve. In order to complement these tests, a new methodology has been developed to test ionosphere models for GNSS. This methodology is based on the position domain, modeling the observables on each frequency with geodetic accuracy, and then to combine the obtained least square solutions to determine the ionosphere error. The results of the testing for different GIMs from IGS and different Signal-in-Space models (GPS, Galileo, and EGNOS) will be presented for 2 years of the last Solar Maximum with more than 40 receivers worldwide. The weaknesses and strengths of the new methodology will also be shown to get a comprehensive idea of its capabilities.

  5. Modeling the global positioning system signal propagation through the ionosphere

    Science.gov (United States)

    Bassiri, S.; Hajj, G. A.

    1992-01-01

    Based on realistic modeling of the electron density of the ionosphere and using a dipole moment approximation for the Earth's magnetic field, one is able to estimate the effect of the ionosphere on the Global Positioning System (GPS) signal for a ground user. The lowest order effect, which is on the order of 0.1-100 m of group delay, is subtracted out by forming a linear combination of the dual frequencies of the GPS signal. One is left with second- and third-order effects that are estimated typically to be approximately 0-2 cm and approximately 0-2 mm at zenith, respectively, depending on the geographical location, the time of day, the time of year, the solar cycle, and the relative geometry of the magnetic field and the line of sight. Given the total electron content along a line of sight, the authors derive an approximation to the second-order term which is accurate to approximately 90 percent within the magnetic dipole moment model; this approximation can be used to reduce the second-order term to the millimeter level, thus potentially improving precise positioning in space and on the ground. The induced group delay, or phase advance, due to second- and third-order effects is examined for two ground receivers located at equatorial and mid-latitude regions tracking several GPS satellites.

  6. INDIRECT MICROLARYNGOSTROBOSCOPIC SURGERY

    NARCIS (Netherlands)

    MAHIEU, HF; DIKKERS, FG

    Detailed preoperative laryngostroboscopic examination is a prerequisite for phonosurgical correction of organic dysphonia. Although suspension microlaryngoscopic surgery has proved its value in the past, it excludes functional control during the removal of vocal fold swellings. Using an indirect

  7. INDIRECT MICROLARYNGOSTROBOSCOPIC SURGERY

    NARCIS (Netherlands)

    MAHIEU, HF; DIKKERS, FG

    1992-01-01

    Detailed preoperative laryngostroboscopic examination is a prerequisite for phonosurgical correction of organic dysphonia. Although suspension microlaryngoscopic surgery has proved its value in the past, it excludes functional control during the removal of vocal fold swellings. Using an indirect mic

  8. Indirect neutrino oscillations

    CERN Document Server

    Babu, K S; Wilczek, Frank; Pati, Jogesh C; Wilczek, Frank

    1995-01-01

    We show how two different scales for oscillations between e and \\mu neutrinos, characterized by different mixing angles and effective mass scales, can arise in a simple and theoretically attractive framework. One scale characterizes direct oscillations, which can accommodate the MSW approach to the solar neutrino problem, whereas the other can be considered as arising indirectly, through virtual transitions involving the \\tau neutrino with a mass \\sim 1 eV. This indirect transition allows the possibility of observable \\bar \

  9. EYESi ophthalmoscope - a simulator for indirect ophthalmoscopic examinations.

    Science.gov (United States)

    Schuppe, Oliver; Wagner, Clemens; Koch, Frank; Männer, Reinhard

    2009-01-01

    We present a training simulator for indirect ophthalmoscopy. An optical tracking system is used to reconstruct the position of a lens mockup and a model of the patient's face. Refraction and illumination are computed in real-time and displayed on a head-mounted display using augmented reality. A case database completes the training system which allows to practise the examination and to study clinical patterns.

  10. Integrated and spatially explicit modelling of the economic value of complex environmental change and its indirect effects

    OpenAIRE

    Bateman, Ian; Binner, Amy; Coombes, Emma; Day, Brett; FERRINI, Silvia; Fezzi, Carlo; Hutchins, Michael; Posen, Paulette

    2012-01-01

    Arguably the greatest challenge to contemporary research is to capture the inter-relatedness and complexity of the real world environment within models so at to better inform decision makers of the accurate and complete consequences of differing options. The paper presents an integrated model of the consequence of climate change upon land use and the secondary and subsequent effects arising subsequently. The model predicts the shift in land use which climate change is likely to induce and the...

  11. Photovoltaic efficiency of an indirect bandgap material

    Science.gov (United States)

    Tomasik, Michelle; Mangan, Niall; Grossman, Jeffrey

    2015-03-01

    Photovoltaic materials with direct band gap transitions absorb light more readily than those with indirect gaps, allowing for thinner devices. However, direct bands also suffer faster rates of radiative recombination than indirect bandgap materials. Some novel photovoltaic absorber materials, such as tin sulfide, have both direct and indirect gaps. Such materials raise the question of whether the multiple energy states benefit or harm device efficiency. We develop a model for current in a device with direct and indirect band gaps using detailed balance, similar to the Shockley-Quiesser model for direct band photovoltaics. We explore the effects of the following on device performance: transition probability of carriers between the direct and indirect state, and relative transport rate in each band.

  12. CAirTOX, An inter-media transfer model for assessing indirect exposures to hazardous air contaminants

    Energy Technology Data Exchange (ETDEWEB)

    McKone, T.E.

    1994-01-01

    Risk assessment is a quantitative evaluation of information on potential health hazards of environmental contaminants and the extent of human exposure to these contaminants. As applied to toxic chemical emissions to air, risk assessment involves four interrelated steps. These are (1) determination of source concentrations or emission characteristics, (2) exposure assessment, (3) toxicity assessment, and (4) risk characterization. These steps can be carried out with assistance from analytical models in order to estimate the potential risk associated with existing and future releases. CAirTOX has been developed as a spreadsheet model to assist in making these types of calculations. CAirTOX follows an approach that has been incorporated into the CalTOX model, which was developed for the California Department of Toxic Substances Control, With CAirTOX, we can address how contaminants released to an air basin can lead to contamination of soil, food, surface water, and sediments. The modeling effort includes a multimedia transport and transformation model, exposure scenario models, and efforts to quantify uncertainty in multimedia, multiple-pathway exposure assessments. The capacity to explicitly address uncertainty has been incorporated into the model in two ways. First, the spreadsheet form of the model makes it compatible with Monte-Carlo add-on programs that are available for uncertainty analysis. Second, all model inputs are specified in terms of an arithmetic mean and coefficient of variation so that uncertainty analyses can be carried out.

  13. System markets: Indirect network effects in action, or inaction?

    NARCIS (Netherlands)

    J.L.G. Binken (Jeroen)

    2010-01-01

    textabstractIn this dissertation, I empirically examine system markets up close. More specifically I examine indirect network effects, both demand-side and supply-side indirect network effects. Indirect network effects are the source of positive feedback in system markets, or so network effect

  14. System markets: Indirect network effects in action, or inaction?

    NARCIS (Netherlands)

    J.L.G. Binken (Jeroen)

    2010-01-01

    textabstractIn this dissertation, I empirically examine system markets up close. More specifically I examine indirect network effects, both demand-side and supply-side indirect network effects. Indirect network effects are the source of positive feedback in system markets, or so network effect theo

  15. Direct and Indirect Effects of Education on Job Satisfaction: A Structural Equation Model for the Spanish Case

    Science.gov (United States)

    Fabra, M. Eugenia; Camison, Cesar

    2009-01-01

    Empirical literature has traditionally analyzed the effect of education on job satisfaction with single-equation models that ignore interrelationships between theoretical explanatory variables. Their results are somewhat inconclusive. We propose estimating a structural equation model to obtain both the direct effects and the set of indirect…

  16. Default risk modeling with position-dependent killing

    Science.gov (United States)

    Katz, Yuri A.

    2013-04-01

    Diffusion in a linear potential in the presence of position-dependent killing is used to mimic a default process. Different assumptions regarding transport coefficients, initial conditions, and elasticity of the killing measure lead to diverse models of bankruptcy. One “stylized fact” is fundamental for our consideration: empirically default is a rather rare event, especially in the investment grade categories of credit ratings. Hence, the action of killing may be considered as a small parameter. In a number of special cases we derive closed-form expressions for the entire term structure of the cumulative probability of default, its hazard rate, and intensity. Comparison with historical data on aggregate global corporate defaults confirms the validity of the perturbation method for estimations of long-term probability of default for companies with high credit quality. On a single company level, we implement the derived formulas to estimate the one-year likelihood of default of Enron on a daily basis from August 2000 to August 2001, three months before its default, and compare the obtained results with forecasts of traditional structural models.

  17. Quantum position verification in bounded-attack-frequency model

    Science.gov (United States)

    Gao, Fei; Liu, Bin; Wen, QiaoYan

    2016-11-01

    In 2011, Buhrman et al. proved that it is impossible to design an unconditionally secure quantum position verification (QPV) protocol if the adversaries are allowed to previously share unlimited entanglements. Afterwards, people started to design secure QPV protocols in practical settings, e.g. the bounded-storage model, where the adversaries' pre-shared entangled resources are supposed to be limited. Here we focus on another practical factor that it is very difficult for the adversaries to perform attack operations with unlimitedly high frequency. Concretely, we present a new kind of QPV protocols, called non-simultaneous QPV. And we prove the security of a specific non-simultaneous QPV protocol with the assumption that the frequency of the adversaries' attack operations is bounded, but no assumptions on their pre-shared entanglements or quantum storage. Actually, in our nonsimultaneous protocol, the information whether there comes a signal at present time is also a piece of command. It renders the adversaries "blind", that is, they have to execute attack operations with unlimitedly high frequency no matter whether a signal arrives, which implies the non-simultaneous QPV is also secure in the bounded-storage model.

  18. Dishabituation processes in height fear and dental fear: an indirect test of the non-associative model of fear acquisition.

    Science.gov (United States)

    Poulton, R; Waldie, K E; Craske, M G; Menzies, R G; McGee, R

    2000-09-01

    The fear dishabituation hypothesis described in the non-associative model of fear acquisition was tested in a longitudinal birth cohort study. Results were consistent with height fear and phobia dishabituation. That is, 're-emergence' of a fear of heights occurred between age 11 and 18 years among individuals who reported higher levels of non-specific stress at age 15. Interestingly, there was no evidence for dental fear dishabituation--a finding consistent with the non-associative model of fear acquisition. Strengths and weaknesses of the study were considered and the results discussed in relation to laboratory-based findings on (dis)habituation.

  19. Adolescent Sibling Relationship Quality and Adjustment: Sibling Trustworthiness and Modeling, as Factors Directly and Indirectly Influencing These Associations

    Science.gov (United States)

    Gamble, Wendy C.; Yu, Jeong Jin; Kuehn, Emily D.

    2011-01-01

    The main goal of this study was to examine the direct and moderating effects of trustworthiness and modeling on adolescent siblings' adjustment. Data were collected from 438 families including a mother, a younger sibling in fifth, sixth, or seventh grade (M = 11.6 years), and an older sibling (M = 14.3 years). Respondents completed Web-based…

  20. Indirect Sexism in Discourse

    Institute of Scientific and Technical Information of China (English)

    彭卓

    2008-01-01

    This thesis draws attention to one of the most vigorous debate in sociolinguistics,sexism in discourse,despite the chicken-and egg question whether it is our language shape sexism or sexism creates certain language.Unlike most researches conducted in sexism and language in the past,we challenge the traditional notion of linguistic sexism and direct our view to what we call "an indirect sexism" here.We then argue the difference between direct and indirect sexism and depict how such an undercurrent drives secretly and carefully in our daily discourse.

  1. Exercise motives and positive body image in physically active college women and men: Exploring an expanded acceptance model of intuitive eating.

    Science.gov (United States)

    Tylka, Tracy L; Homan, Kristin J

    2015-09-01

    The acceptance model of intuitive eating posits that body acceptance by others facilitates body appreciation and internal body orientation, which contribute to intuitive eating. Two domains of exercise motives (functional and appearance) may also be linked to these variables, and thus were integrated into the model. The model fit the data well for 406 physically active U.S. college students, although some pathways were stronger for women. Body acceptance by others directly contributed to higher functional exercise motives and indirectly contributed to lower appearance exercise motives through higher internal body orientation. Functional exercise motives positively, and appearance exercise motives inversely, contributed to body appreciation. Whereas body appreciation positively, and appearance exercise motives inversely, contributed to intuitive eating for women, only the latter association was evident for men. To benefit positive body image and intuitive eating, efforts should encourage body acceptance by others and emphasize functional and de-emphasize appearance exercise motives.

  2. INDIRECT ACCELERATED ADAPTIVE FUZZY CONTROLLER

    Institute of Scientific and Technical Information of China (English)

    ZHU Liye; FANG Yuan; ZHANG Weidong

    2008-01-01

    According to a type of normal nonlinear system, an indirect adaptive fuzzy (IAF) controller has been applied to those systems where no accurate mathematical models of the systems under control are available. To satisfy with system performance, an indirect accelerated adaptive fuzzy (IAAF) controller is proposed, and its general form is presented. The general form IAAF controller ensures necessary control criteria and system's global stability using Lyapunov Theorem. It has been proved that the close-loop system error converges to a small neighborhood of equilibrium point. The optimal IAAF controller is derived to guarantee the process's shortest settling time. Simulation results indicate the IAAF controller make the system more stable, accurate, and fast.

  3. Indirect reciprocity with trinary reputations

    CERN Document Server

    Tanabe, Shoma; Masuda, Naoki

    2012-01-01

    Indirect reciprocity is a reputation-based mechanism for cooperation in social dilemma situations when individuals do not repeatedly meet. The conditions under which cooperation based on indirect reciprocity occurs has been examined in great details. Previous theoretical analysis assumed for mathematical tractability that an individual possesses a binary reputation value, i.e., good or bad, which depends on their past actions and other factors. However, in real situations, reputations of individuals may be multiple valued. Another puzzling discrepancy between the theory and experiments is the status of the so-called image scoring, in which cooperation and defection are judged to be good and bad, respectively, independent of other factors. Such an assessment rule is found in behavioral experiments, whereas it is known to be unstable in theory. In the present study, we fill both gaps by theoretical analysis of a trinary reputation model. By an exhaustive search, we identify all the cooperative and stable equili...

  4. Positive dynamical systems in discrete time theory, models, and applications

    CERN Document Server

    Krause, Ulrich

    2015-01-01

    This book provides a systematic, rigorous and self-contained treatment of positive dynamical systems. A dynamical system is positive when all relevant variables of a systemare nonnegative in a natural way. This is in biology, demography or economics, where the levels of populations or prices of goods are positive. The principle also finds application in electrical engineering, physics and computer sciences.

  5. Indirect inference with time series observed with error

    DEFF Research Database (Denmark)

    Rossi, Eduardo; Santucci de Magistris, Paolo

    We analyze the properties of the indirect inference estimator when the observed series are contaminated by measurement error. We show that the indirect inference estimates are asymptotically biased when the nuisance parameters of the measurement error distribution are neglected in the indirect...... to estimate the parameters of continuous-time stochastic volatility models with auxiliary specifications based on realized volatility measures. Monte Carlo simulations shows the bias reduction of the indirect estimates obtained when the microstructure noise is explicitly modeled. Finally, an empirical...

  6. Conversion of Rapid Prototyping Models into Metallic Tools by Ceramic Moulding—an Indirect Rapid Tooling Process

    Institute of Scientific and Technical Information of China (English)

    Teresa; P; DUARTE; J; M; FERREIRA; F; Jorge; LINO; A; BARBEDO; Rui; NETO

    2002-01-01

    A process to convert models made by rapid prototypi ng techniques like SL (stereolitography) and LOM (laminated object manufacturing) or by conventional techniques (silicones, resins, wax, etc.) into metallic mould s or tools has been developed. The main purpose of this technique is to rapidly obtain the first prototypes of parts, for plastics injection, forging or any oth er manufacturing process using the tools produced by casting a metal into a cera mic mould. Briefly, it can be said that the ceramic...

  7. Soil moisture data for the validation of permafrost models using direct and indirect measurement approaches at three alpine sites

    Directory of Open Access Journals (Sweden)

    Cécile ePellet

    2016-01-01

    Full Text Available In regions affected by seasonal and permanently frozen conditions soil moisture influences the thermal regime of the ground as well as its ice content, which is one of the main factors controlling the sensitivity of mountain permafrost to climate changes. In this study, several well established soil moisture monitoring techniques were combined with data from geophysical measurements to assess the spatial distribution and temporal evolution of soil moisture at three high elevation sites with different ground properties and thermal regimes. The observed temporal evolution of measured soil moisture is characteristic for sites with seasonal freeze/thaw cycles and consistent with the respective site-specific properties, demonstrating the general applicability of continuous monitoring of soil moisture at high elevation areas. The obtained soil moisture data were then used for the calibration and validation of two different model approaches in permafrost research in order to characterize the lateral and vertical distribution of ice content in the ground. Calibration of the geophysically based four-phase model (4PM with spatially distributed soil moisture data yielded satisfactory two dimensional distributions of water-, ice- and air content. Similarly, soil moisture time series significantly improved the calibration of the one-dimensional heat and mass transfer model COUP, yielding physically consistent soil moisture and temperature data matching observations at different depths.

  8. The efficient model to define a single light source position by use of high dynamic range image of 3D scene

    Science.gov (United States)

    Wang, Xu-yang; Zhdanov, Dmitry D.; Potemin, Igor S.; Wang, Ying; Cheng, Han

    2016-10-01

    One of the challenges of augmented reality is a seamless combination of objects of the real and virtual worlds, for example light sources. We suggest a measurement and computation models for reconstruction of light source position. The model is based on the dependence of luminance of the small size diffuse surface directly illuminated by point like source placed at a short distance from the observer or camera. The advantage of the computational model is the ability to eliminate the effects of indirect illumination. The paper presents a number of examples to illustrate the efficiency and accuracy of the proposed method.

  9. Measures and models of nicotine dependence: positive reinforcement.

    Science.gov (United States)

    Glautier, Steven

    2004-06-01

    This paper addresses the problem of assessing nicotine dependence. The main objective is to develop theory-led suggestions for measures that will be relevant in the early phases of tobacco use, as well as in established smokers. Theoretical models of addiction falling into the general class of 'positive reinforcement theories' were identified and reviewed. From this review a number of drug effects and patterns of behaviour were distilled and categorized as either vulnerability or dependence indicators. A comparison of those features with the International Classification of Diseases (ICD-10) and Diagnostic and Statistical Manual (DSM-IV) diagnostic systems shows that neither system includes detailed assessment of vulnerability indicators. It is argued that measurement of vulnerability indicators, in addition to dependence indicators, may add to the predictive validity of assessments carried out in early career tobacco users, especially where there is limited evidence of established dependence. In addition, it is suggested that examination of measures that differentiate a subgroup of early career smokers termed 'rapid accelerators' may prove profitable and enable identification of the key parameters of nicotine reinforcement.

  10. Indirect airway challenges

    NARCIS (Netherlands)

    Joos, GF; O'Connor, B; Anderson, SD; Chung, F; Cockcroft, DW; Dahlen, B; DiMaria, G; Foresi, A; Hargreave, FE; Holgate, ST; Inman, M; Lotvall, J; Magnussen, H; Polosa, R; Postma, DS; Riedler, J

    2003-01-01

    Indirect challenges act by causing the release of endogenous mediators that cause the airway smooth muscle to contract. This is in contrast to the direct challenges where agonists such as methacholine or histamine cause airflow limitation predominantly via a direct effect on airway smooth muscle. Di

  11. Modelling of Indirect Laser-induced Thin-film Ablation of Epoxy for Local Exposing of Carbon Fibers

    Science.gov (United States)

    Emonts, Michael; Fischer, Kai; Schmitt, Stefan; Schares, Richard Ludwig

    Laser radiation is used as enabling technology for intrinsic joining of high-strength CFRP laminates and fiber-reinforced thermoplastic injection moulding compounds by exposure of surface-near carbon fibers. Short-pulsed NIR laser sources represent an acceptable compromise with respect to ablation performance, remote process capability by use of compact 3D scanner and the capability for closed-loop process control. However, using such a laser source means also minimizing heat-affected zones (HAZ). Based on literature research about laser ablation of thin metal films, heat flow at CFRP and thermo-mechanical behavior in FRP by pyrolysis, an analytical model was generated for thin-film ablation of cured epoxy resins at the surface of CFRP laminates by lift-off of resin chips. A comparison between simulation and experimental results confirms the capability of the model to predict the exposure area and the HAZ with deviations below 15%. Threshold fluences for the HAZ (>1 J/cm2) and the resin ablation (>3 J/cm2) have been confirmed.

  12. Testing alternative models for sexual isolation in natural populations of Littorina saxatilis: indirect support for by-product ecological speciation?

    Science.gov (United States)

    Cruz, R; Carballo, M; Conde-Padín, P; Rolán-Alvarez, E

    2004-03-01

    Two ecotypes of the rough periwinkle Littorina saxatilis occur at different shore levels, showing assortative mating for size and partial reproductive isolation when they meet at the mid-shore. This system represents a putative case of incomplete speciation in sympatry. Two processes contribute to the assortative mating: morph-specific microhabitat aggregation and mate choice. The estimation of mate choice coefficients in nature and a simulation of the aggregation effects on sexual isolation were used to disentangle these processes as well as to test alternative mechanisms of mate choice. Mate choice significantly increased the frequency of within-morph pairs and significantly decreased the frequency of between-morph pairs, whereas those pairs including at least one hybrid morph mated randomly. These results allow us to reject a discriminant mate choice and support a model of evolution of sexual isolation as a side-effect of size-assortative mating in a context of divergent natural selection for size in the population. This mechanism is more compatible with a model of incomplete by-product ecological speciation, as suggested by previous evidence.

  13. Precise computation of the direct and indirect topographic effects of Helmert's 2nd method of condensation using SRTM30 digital elevation model

    Science.gov (United States)

    Wang, Y.

    2011-01-01

    The direct topographic effect (DTE) and indirect topographic effect (ITE) of Helmert's 2nd method of condensation are computed using the digital elevation model (DEM) SRTM30 in 30 arc-seconds globally. The computations assume a constant density of the topographic masses. Closed formulas are used in the inner zone of half degree, and Nagy's formulas are used in the innermost column to treat the singularity of integrals. To speed up the computations, 1-dimensional fast Fourier transform (1D FFT) is applied in outer zone computations. The computation accuracy is limited to 0.1 mGal and 0.1cm for the direct and indirect effect, respectively. The mean value and standard deviation of the DTE are -0.8 and ±7.6 mGal over land areas. The extreme value -274.3 mGal is located at latitude -13.579° and longitude 289.496°, at the height of 1426 meter in the Andes Mountains. The ITE is negative everywhere and has its minimum of -235.9 cm at the peak of Himalayas (8685 meter). The standard deviation and mean value over land areas are ±15.6 cm and -6.4 cm, respectively. Because the Stokes kernel does not contain the zero and first degree spherical harmonics, the mean value of the ITE can't be compensated through the remove-restore procedure under the Stokes-Helmert scheme, and careful treatment of the mean value in the ITE is required.

  14. Modelling and control for position-controlled modular robot manipulators

    OpenAIRE

    Shao, Zilong; Zheng, Gang; Efimov, Denis; Perruquetti, Wilfrid

    2015-01-01

    International audience; Modular Robot Manipulators are user-configurable manipulators which provide rapid design and inexpensive implementation. To be easy-use, smart actuators embedded with position input and position feedback controller are adopted, these local controllers render the manipulators position controlled, but also result in limited performance and precision. This paper targets the case that the built-in controller does not provide desirable precision for set-point regulation. Fi...

  15. Medium to Long Range Kinematic GPS Positioning with Position-Velocity-Acceleration Model Using Multiple Reference Stations.

    Science.gov (United States)

    Hong, Chang-Ki; Park, Chi Ho; Han, Joong-hee; Kwon, Jay Hyoun

    2015-07-13

    In order to obtain precise kinematic global positioning systems (GPS) in medium to large scale networks, the atmospheric effects from tropospheric and ionospheric delays need to be properly modeled and estimated. It is also preferable to use multiple reference stations to improve the reliability of the solutions. In this study, GPS kinematic positioning algorithms are developed for the medium to large-scale network based on the position-velocity-acceleration model. Hence, the algorithm can perform even in cases where the near-constant velocity assumption does not hold. In addition, the estimated kinematic accelerations can be used for the airborne gravimetry. The proposed algorithms are implemented using Kalman filter and are applied to the in situ airborne GPS data. The performance of the proposed algorithms is validated by analyzing and comparing the results with those from reference values. The results show that reliable and comparable solutions in both position and kinematic acceleration levels can be obtained using the proposed algorithms.

  16. Parameterization of aerosol indirect effect to complement McRAS cloud scheme and its evaluation with the 3-year ARM-SGP analyzed data for single column models

    Science.gov (United States)

    Sud, Y. C.; Lee, Dongmin

    2007-11-01

    Microphysics of clouds with the Relaxed Arakawa-Schubert Scheme (McRAS) was upgraded for simulating the Aerosol Indirect Effects (AIE) for water clouds. The AIE comprises of i) Fountoukis and Nenes aerosol activation module for obtaining cloud condensation nuclei; ii) Seifert and Beheng algorithms for precipitation microphysics but with modified accretion constant for the coarse vertical-resolution typical of a global general circulation model (GCM); and iii) Khvorostyanov and Curry parameterization for computing the effective radius ( re) of cloud drops. The upgraded package, named McRAS-AC, was evaluated using the 3-year ARM-SGP Single Column Model (SCM) data. Invoking only the most dominant sulfate aerosols over the region, McRAS-AC simulated realistic annual mean and annual cycles of cloud water, cloud optical thicknesses, cloud drop number concentration, and re. The follow-on SCM-sensitivity simulations showed that accretion of cloud water is sensitive to i) the terminal velocity of hydrometeors produced by autoconversion and ii) cloud height increases due to in-cloud condensation heating. The impact of aerosol mass concentration on the resultant column cloud water, and bulk optical properties of clouds were assessed by using 1/8 to 8 times the average monthly aerosol mass concentration estimates of GOCART aerosol climatology. A log-linear relation between cloud-radiative forcing and aerosol-mass concentration emerged in the simulated data.

  17. Indirect resin composites

    Directory of Open Access Journals (Sweden)

    Nandini Suresh

    2010-01-01

    Full Text Available Aesthetic dentistry continues to evolve through innovations in bonding agents, restorative materials, and conservative preparation techniques. The use of direct composite restoration in posterior teeth is limited to relatively small cavities due to polymerization stresses. Indirect composites offer an esthetic alternative to ceramics for posterior teeth. This review article focuses on the material aspect of the newer generation of composites. This review was based on a PubMed database search which we limited to peer-reviewed articles in English that were published between 1990 and 2010 in dental journals. The key words used were ′indirect resin composites,′ composite inlays,′ and ′fiber-reinforced composites.′

  18. Pedal indirect lymphangiography

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kil Woo; Hong, Myung Sun; Kim, In Jae [College of Medicine, Hallym University, Seoul (Korea, Republic of)

    1994-04-15

    Recently, indirect lymphangiography has been developed as a relatively good and noninvasive imaging modality of the lymphatic system at extremities. But the disadvantage of the indirect lymphangiography is a low contrast ratio between the surrounding tissues and the contrast media in lymphatic vessels, because dimeric nonionic contrast media is water soluble and diluted in the proximal leg lymphatic vessels. We could have relatively better image than previously published images for the leg lymphatic system, when we injected contrast media with adequate high pressure in intradermal space of the interdigital areas at the foot dorsum. So, we would like to report the results. We could study all 9 lymphedemas(primary: 6, secondary: 3) from April 1990 to May 1993 on outpatient base. They were diagnosed as lymphedema clinically and radiologically. Ten ml of dimeric nonionic aget, iotrolan(Isovist 300) was injected into intradermal space with five 30-gauge needles. The injection speed was more than 0.2 ml/min. We have done one side pedal lymphangiogram in 30 minutes. The evaluation of the anterior superficial lymphatics was according to the criteria of the Weissleder. The results were as follows: 1. All lymphatic vessels from foot to inguinal area could be visualized. 2. Two or three inferior inguinal lymph nodes could be visualized about 42%. 3. The most common abnormal finding of the lymphedma was the neovascularization of the lymphatics on indirect pedal lymphangiogram. If we use adequate technique relatively high pressure injection, correct intradermal needle insertion, adequate soft tissue exposure technique indirect lymphangiography is considered to be a safe and noninvasive imaging modality for the evaluation of the lymphedema of lower extremity lymphatics including inferior inguinal lymph nodes.

  19. Indirect reciprocity with trinary reputations.

    Science.gov (United States)

    Tanabe, Shoma; Suzuki, Hideyuki; Masuda, Naoki

    2013-01-21

    Indirect reciprocity is a reputation-based mechanism for cooperation in social dilemma situations when individuals do not repeatedly meet. The conditions under which cooperation based on indirect reciprocity occurs have been examined in great details. Most previous theoretical analysis assumed for mathematical tractability that an individual possesses a binary reputation value, i.e., good or bad, which depends on their past actions and other factors. However, in real situations, reputations of individuals may be multiple valued. Another puzzling discrepancy between the theory and experiments is the status of the so-called image scoring, in which cooperation and defection are judged to be good and bad, respectively, independent of other factors. Such an assessment rule is found in behavioral experiments, whereas it is known to be unstable in theory. In the present study, we fill both gaps by analyzing a trinary reputation model. By an exhaustive search, we identify all the cooperative and stable equilibria composed of a homogeneous population or a heterogeneous population containing two types of players. Some results derived for the trinary reputation model are direct extensions of those for the binary model. However, we find that the trinary model allows cooperation under image scoring under some mild conditions. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Optimism, pessimism, and positive and negative affectivity in middle-aged adults: a test of a cognitive-affective model of psychological adjustment.

    Science.gov (United States)

    Chang, E C; Sanna, L J

    2001-09-01

    This study attempted to address limitations in the understanding of optimism and pessimism among middle-aged adults. Specifically, a model of affectivity as a mediator of the link between outcome expectancies and psychological adjustment (life satisfaction and depressive symptoms) was presented and examined in a sample of 237 middle-aged adults. Consistent with a mediation model, results of path analyses indicated that optimism and pessimism (particularly the former) had significant direct and indirect links (by means of positive and negative affectivity) with depressive symptoms and life satisfaction. These results add to the small but growing literature identifying optimism and pessimism as important concomitants of psychological adjustment in more mature adults.

  1. Sensitivity of 96 and 120-hour Numerical Model Tropical Cyclone Position Forecasts to Initial Position Errors

    Science.gov (United States)

    2014-03-27

    to thank my Lord and Savior Jesus Christ who has graciously granted me the opportunities in this life. Secondly, to my beautiful wife, I am indebted... original Matrix Laboratory (MATLAB R©) software routine performed numerical computations using JTWC best track data, JTWC warning bulletins, and GFS...weighting function and the model parameter values at the model’s original grid resolution, but regardless of the ultimate grid resolution, the vortex

  2. Aerosol indirect effect on the grid-scale clouds in the two-way coupled WRF–CMAQ: model description, development, evaluation and regional analysis

    Energy Technology Data Exchange (ETDEWEB)

    Yu, S.; Mathur, R.; Pleim, J.; Wong, D.; Gilliam, R.; Alapaty, K.; Zhao, C.; Liu, X.

    2014-01-01

    This study implemented first, second and glaciation aerosol indirect effects (AIE) on resolved clouds in the two-way coupled Weather Research and Forecasting Community Multiscale Air Quality (WRF–CMAQ) modeling system by including parameterizations for both cloud drop and ice number concentrations on the basis of CMAQ-predicted aerosol distributions and WRF meteorological conditions. The performance of the newly developed WRF–CMAQ model, with alternate Community Atmospheric Model (CAM) and Rapid Radiative Transfer Model for GCMs (RRTMG) radiation schemes, was evaluated with observations from the Clouds and the See http://ceres.larc.nasa.gov/. Earth's Radiant Energy System (CERES) satellite and surface monitoring networks (AQS, IMPROVE, CASTNET, STN, and PRISM) over the continental US (CONUS) (12 km resolution) and eastern Texas (4 km resolution) during August and September of 2006. The results at the Air Quality System (AQS) surface sites show that in August, the normalized mean bias (NMB) values for PM2.5 over the eastern US (EUS) and the western US (WUS) are 5.3% (-0.1%) and 0.4% (-5.2%) for WRF–CMAQ/CAM (WRF–CMAQ/RRTMG), respectively. The evaluation of PM2.5 chemical composition reveals that in August, WRF–CMAQ/CAM (WRF–CMAQ/RRTMG) consistently underestimated the observed SO42- by -23.0% (-27.7%), -12.5% (-18.9%) and -7.9% (-14.8%) over the EUS at the Clean Air Status Trends Network (CASTNET), Interagency Monitoring of Protected Visual Environments (IMPROVE) and Speciated Trends Network (STN) sites, respectively. Both configurations (WRF–CMAQ/CAM, WRF–CMAQ/RRTMG) overestimated the observed mean organic carbon (OC), elemental carbon (EC) and and total carbon (TC) concentrations over the EUS in August at the IMPROVE sites. Both configurations generally underestimated the cloud field (shortwave cloud forcing, SWCF) over the CONUS in August due

  3. Reparameterization of Single Difference and Undifferenced Kinematic GPS Positioning Models

    Institute of Scientific and Technical Information of China (English)

    LIU Xianglin; C D Jong; C C J M Tiberius

    2003-01-01

    A series of advantages of single difference (SD)and undifferenced (ZD) models are given as compared wity the double difference ezist in SD and ZD models.The reparameterization method is provided to resolve this rank defect problem by estimating some combinations of the unknowns rather than the unknowns themselves. The repatameterization of SD and ZD functional models is discussed in detail with their stochastic models. The theoretical comformation of the equivalence of undifferenced and differenced models is described in a straightforward way .The relationship between SD and ZD residuals is given and verified for some special purposes,e.g.research on the stochastical properties of GPS observations.

  4. Simple model of the indirect compression of targets under conditions close to the national ignition facility at an energy of 1.5 MJ

    Energy Technology Data Exchange (ETDEWEB)

    Rozanov, V. B., E-mail: rozanov@sci.lebedev.ru; Vergunova, G. A., E-mail: verg@sci.lebedev.ru [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)

    2015-11-15

    The possibility of the analysis and interpretation of the reported experiments with the megajoule National Ignition Facility (NIF) laser on the compression of capsules in indirect-irradiation targets by means of the one-dimensional RADIAN program in the spherical geometry has been studied. The problem of the energy balance in a target and the determination of the laser energy that should be used in the spherical model of the target has been considered. The results of action of pulses differing in energy and time profile (“low-foot” and “high-foot” regimes) have been analyzed. The parameters of the compression of targets with a high-density carbon ablator have been obtained. The results of the simulations are in satisfactory agreement with the measurements and correspond to the range of the observed parameters. The set of compared results can be expanded, in particular, for a more detailed determination of the parameters of a target near the maximum compression of the capsule. The physical foundation of the possibility of using the one-dimensional description is the necessity of the closeness of the last stage of the compression of the capsule to a one-dimensional process. The one-dimensional simulation of the compression of the capsule can be useful in establishing the boundary behind which two-dimensional and three-dimensional simulation should be used.

  5. Simple model of the indirect compression of targets under conditions close to the national ignition facility at an energy of 1.5 MJ

    Science.gov (United States)

    Rozanov, V. B.; Vergunova, G. A.

    2015-11-01

    The possibility of the analysis and interpretation of the reported experiments with the megajoule National Ignition Facility (NIF) laser on the compression of capsules in indirect-irradiation targets by means of the one-dimensional RADIAN program in the spherical geometry has been studied. The problem of the energy balance in a target and the determination of the laser energy that should be used in the spherical model of the target has been considered. The results of action of pulses differing in energy and time profile ("low-foot" and "high-foot" regimes) have been analyzed. The parameters of the compression of targets with a high-density carbon ablator have been obtained. The results of the simulations are in satisfactory agreement with the measurements and correspond to the range of the observed parameters. The set of compared results can be expanded, in particular, for a more detailed determination of the parameters of a target near the maximum compression of the capsule. The physical foundation of the possibility of using the one-dimensional description is the necessity of the closeness of the last stage of the compression of the capsule to a one-dimensional process. The one-dimensional simulation of the compression of the capsule can be useful in establishing the boundary behind which two-dimensional and three-dimensional simulation should be used.

  6. Evaluation of the aerosol indirect effect using satellite, tracer transport model, and aircraft data from the International Consortium for Atmospheric Research on Transport and Transformation

    Science.gov (United States)

    Avey, L.; Garrett, T. J.; Stohl, A.

    2007-05-01

    The magnitudes of the "indirect effects" that anthropogenic aerosols have on clouds and climate remain uncertain. Past space-based characterizations have compared satellite retrievals of cloud properties with satellite- or model-derived aerosol quantities. The two fields have been taken from air masses displaced from each other either horizontally or vertically. Thus, almost by definition, the cloud retrievals have come from different meteorological regimes than the aerosol to which ostensibly they are related. Because cloud properties depend foremost on meteorology, the difference introduces undesired ambiguity in the comparisons. In this study, we compare Terra and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) cloud retrievals with high spatial and temporal resolution output from a tracer transport model (FLEXPART), enabling colocation of fields of pollution and clouds both vertically and horizontally. Anthropogenic carbon monoxide (CO) is used as a passive pollution tracer, because its concentrations are tied to mixing and pollutant source strength, and they are independent of atmospheric oxidation and removal processes on timescales of weeks to months. Cloud and pollution fields are compared along a downwind axis from the U.S. northeastern seaboard for the duration of the summer 2004 International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) mission. Where the transport model indicates air as being polluted, cloud re is smaller and cloud optical depth is in some cases higher, at least close to primary source regions. However, within 4 ± 1 days advection time from the northeastern seaboard, cloud perturbations become negligible, probably because of wet-scavenging of CCN. No conclusive evidence was found for any perturbation to cloud liquid water path by pollution.

  7. 电子商务物流中的间接配送模式研究%Research on the Indirect Distribution Model in the E-commerce Logistics System

    Institute of Scientific and Technical Information of China (English)

    杨聚平; 杨长春; 姚宣霞

    2014-01-01

    In order to solve the problems in the last one -kilometre distribution of domestic electronic commerce logis-tics, firstly, the distribution models in some developed countries and regions are studied deeply .By analyzing and classi-fying the distribution models , the paper points out that the indirect distribution model is the direction of development in the last one-kilometre distribution of electronic commerce logistics in China .Secondly , the analysis result on the ques-tionnaire proves that implementing indirect distribution model in China is feasible .Finally, the 3 guiding principles to carry out indirect distribution model are summed up , the situation that is suitable for indirect distribution model and the applicable scope of various indirect distribution models are analyzed .%针对国内电子商务物流“最后一公里”配送中的问题,本文研究了一些发达国家和地区的配送形式,通过对这些配送形式的归类分析,指出间接配送模式是我国电子商务物流“最后一公里”配送阶段未来的发展方向;通过对调查问卷的分析证明了目前在我国推行间接配送模式的可行性,并指出间接配送模式需遵循的指导原则、目前国内可推行间接配送模式的场合以及各种间接配送形式的适用范围。

  8. Positive random fields for modeling material stiffness and compliance

    DEFF Research Database (Denmark)

    Hasofer, Abraham Michael; Ditlevsen, Ove Dalager; Tarp-Johansen, Niels Jacob

    1998-01-01

    Positive random fields with known marginal properties and known correlation function are not numerous in the literature. The most prominent example is the log\\-normal field for which the complete distribution is known and for which the reciprocal field is also lognormal. It is of interest to supp...

  9. Cosmological models with positive scalar spatial curvature and Λ>0

    Science.gov (United States)

    Ponce de Leon, J.

    1987-12-01

    Some exact spherically symmetric solutions of the Einstein field equations with Λ>0 and positive three-curvature are given. They have reasonable physical properties and represent universes which do not undergo inflation but have a non-de Sitter behaviour for large times. This paper extends some previous results in the literature. Permanent address: Apartado 2816, Caracas 1010-A, Venezuela.

  10. Social Validity of a Positive Behavior Interventions and Support Model

    Science.gov (United States)

    Miramontes, Nancy Y.; Marchant, Michelle; Heath, Melissa Allen; Fischer, Lane

    2011-01-01

    As more schools turn to positive behavior interventions and support (PBIS) to address students' academic and behavioral problems, there is an increased need to adequately evaluate these programs for social relevance. The present study used social validation measures to evaluate a statewide PBIS initiative. Active consumers of the program were…

  11. Indirect radioimmunoassay for interferon

    Energy Technology Data Exchange (ETDEWEB)

    Lyons, S.F.; Schoub, B.D. (University of the Witwatersrand, Johannesburg (South Africa). Dept. of Virology); Chiu, M.N.; Crespi, M. (National Institute for Virology, Johannesburg (South Africa))

    1982-10-01

    An indirect radioimmunoassay for testing the antiviral activity of interferon (IFN) is described. Vero cells are seeded in microtitre plates, treated with appropriate dilutions of interferon and challenged with Sindbis virus. Viral yield is measured using specific antibody and radiolabelled protein A. The assay is able to detect IFN levels of 5 international units (I.U.)/ml, has a high degree of reproducibility, and could be easily adapted to various cell and virus combinations. This microsystem is technically simple, allows testing of small volumes of test material, and eliminates subjectivity in reading of endpoints.

  12. Modeling, Simulation and Position Control of 3DOF Articulated Manipulator

    Directory of Open Access Journals (Sweden)

    Hossein Sadegh Lafmejani

    2014-08-01

    Full Text Available In this paper, the modeling, simulation and control of 3 degrees of freedom articulated robotic manipulator have been studied. First, we extracted kinematics and dynamics equations of the mentioned manipulator by using the Lagrange method. In order to validate the analytical model of the manipulator we compared the model simulated in the simulation environment of Matlab with the model was simulated with the SimMechanics toolbox. A sample path has been designed for analyzing the tracking subject. The system has been linearized with feedback linearization and then a PID controller was applied to track a reference trajectory. Finally, the control results have been compared with a nonlinear PID controller.

  13. A Nonlinear Model for Relativistic Electrons at Positive Temperature

    OpenAIRE

    Hainzl, Christian; Lewin, Mathieu; Seiringer, Robert

    2008-01-01

    We study the relativistic electron-positron field at positive temperature in the Hartree-Fock-approximation. We consider both the case with and without exchange term, and investigate the existence and properties of minimizers. Our approach is non-perturbative in the sense that the relevant electron subspace is determined in a self-consistent way. The present work is an extension of previous work by Hainzl, Lewin, S\\'er\\'e, and Solovej where the case of zero temperature was considered.

  14. Bioechnology of indirect liquefaction

    Energy Technology Data Exchange (ETDEWEB)

    Datta, R.; Jain, M.K.; Worden, R.M.; Grethlein, A.J.; Soni, B.; Zeikus, J.G.; Grethlein, H.

    1990-05-07

    The project on biotechnology of indirect liquefaction was focused on conversion of coal derived synthesis gas to liquid fuels using a two-stage, acidogenic and solventogenic, anaerobic bioconversion process. The acidogenic fermentation used a novel and versatile organism, Butyribacterium methylotrophicum, which was fully capable of using CO as the sole carbon and energy source for organic acid production. In extended batch CO fermentations the organism was induced to produce butyrate at the expense of acetate at low pH values. Long-term, steady-state operation was achieved during continuous CO fermentations with this organism, and at low pH values (a pH of 6.0 or less) minor amounts of butanol and ethanol were produced. During continuous, steady-state fermentations of CO with cell recycle, concentrations of mixed acids and alcohols were achieved (approximately 12 g/l and 2 g/l, respectively) which are high enough for efficient conversion in stage two of the indirect liquefaction process. The metabolic pathway to produce 4-carbon alcohols from CO was a novel discovery and is believed to be unique to our CO strain of B. methylotrophicum. In the solventogenic phase, the parent strain ATCC 4259 of Clostridium acetobutylicum was mutagenized using nitrosoguanidine and ethyl methane sulfonate. The E-604 mutant strain of Clostridium acetobutylicum showed improved characteristics as compared to parent strain ATCC 4259 in batch fermentation of carbohydrates.

  15. An integrable 3D lattice model with positive Boltzmann weights

    CERN Document Server

    Mangazeev, Vladimir V; Sergeev, Sergey M

    2013-01-01

    In this paper we construct a three-dimensional (3D) solvable lattice model with non-negative Boltzmann weights. The spin variables in the model are assigned to edges of the 3D cubic lattice and run over an infinite number of discrete states. The Boltzmann weights satisfy the tetrahedron equation, which is a 3D generalisation of the Yang-Baxter equation. The weights depend on a free parameter 0model form a two-parameter commutative family. This is the first example of a solvable 3D lattice model with non-negative Boltzmann weights.

  16. An Indirect Route for Ethanol Production

    Energy Technology Data Exchange (ETDEWEB)

    Eggeman, T.; Verser, D.; Weber, E.

    2005-04-29

    The ZeaChem indirect method is a radically new approach to producing fuel ethanol from renewable resources. Sugar and syngas processing platforms are combined in a novel way that allows all fractions of biomass feedstocks (e.g. carbohydrates, lignins, etc.) to contribute their energy directly into the ethanol product via fermentation and hydrogen based chemical process technologies. The goals of this project were: (1) Collect engineering data necessary for scale-up of the indirect route for ethanol production, and (2) Produce process and economic models to guide the development effort. Both goals were successfully accomplished. The projected economics of the Base Case developed in this work are comparable to today's corn based ethanol technology. Sensitivity analysis shows that significant improvements in economics for the indirect route would result if a biomass feedstock rather that starch hydrolyzate were used as the carbohydrate source. The energy ratio, defined as the ratio of green energy produced divided by the amount of fossil energy consumed, is projected to be 3.11 to 12.32 for the indirect route depending upon the details of implementation. Conventional technology has an energy ratio of 1.34, thus the indirect route will have a significant environmental advantage over today's technology. Energy savings of 7.48 trillion Btu/yr will result when 100 MMgal/yr (neat) of ethanol capacity via the indirect route is placed on-line by the year 2010.

  17. Modelling and measurements of fibrinogen adsorption on positively charged microspheres

    Directory of Open Access Journals (Sweden)

    P. Zeliszewska

    2016-02-01

    Full Text Available Adsorption of fibrinogen on positively charged microspheres was theoretically and experimentally studied. The structure of monolayers and the maximum coverage were determined by applying the experimental measurements at pH = 3.5 and 9.7 for NaCl concentration in the range of 10^{-3} - 0.15 M. The maximum coverage of fibrinogen on latex particles was precisely determined by the AFM method. Unexpectedly, at pH = 3.5, where both fibrinogen molecule and the latex particles were positively charged, the maximum coverage varied between 0.9 mg m^{-2} and 1.1 mg m^{-2} for 10^{-2} and 0.15 M NaCl, respectively. On the other hand, at pH = 9.7, the maximum coverage of fibrinogen was larger, varying between 1.8 mg m^{-2} and 3.4 mg m^{-2} for 10^{-2} and 0.15 M NaCl, respectively. The experimental results were quantitatively interpreted by the numerical simulations.

  18. Cloud-resolving modeling of aerosol indirect effects in idealized radiative-convective equilibrium with interactive and fixed sea surface temperature

    Directory of Open Access Journals (Sweden)

    M. F. Khairoutdinov

    2012-11-01

    Full Text Available The study attempts to evaluate the aerosol indirect effects over tropical oceans in regions of deep convection applying a three-dimensional cloud-resolving model run over a doubly-periodic domain. The Tropics are modeled using a radiative-convective equilibrium idealization when the radiation, turbulence, cloud microphysics, and surface fluxes are explicitly represented while the effects of large-scale circulation are ignored. The aerosol effects are modeled by varying the number concentration of cloud condensation nuclei (CCN at 1% supersaturation, which serves as a proxy for the aerosol amount in the environment, over a wide range, starting from pristine maritime (50 cm−3 to polluted (1000 cm−3 conditions. No direct effects of aerosol on radiation are included. Two sets of simulations have been run to equilibrium: fixed (non-interactive sea surface temperature (SST and interactive SST as predicted by a simple slab-ocean model responding to the surface radiative fluxes and surface enthalpy flux. Both sets of experiments agree on the tendency to make the shortwave cloud forcing more negative and reduce the longwave cloud forcing in response to increasing CCN concentration. These, in turn, tend to cool the SST in interactive-SST case. It is interesting that the absolute change of the SST and most other bulk quantities depends only on relative change of CCN concentration; that is, same SST change can be the result of doubling CCN concentration regardless of clean or polluted conditions. It is found that the 10-fold increase of CCN concentration can cool the SST by as much as 1.5 K. This is quite comparable to 2 K warming obtained in a simulation for clean maritime conditions, but doubled CO2 concentration. Qualitative differences between the interactive and fixed SST cases have been found in sensitivity of the hydrological cycle to the increase in CCN concentration; namely, the precipitation rate shows some

  19. Oil shocks in New Keynesian models: Positive and normative implications

    Science.gov (United States)

    Chang, Jian

    Chapter 1 investigates optimal monetary policy response towards oil shocks in a New Keynesian model. We find that optimal policy, in general, becomes contractionary in response to an adverse oil shock. However, the optimal policy rule and the inflation-output trade-off depend on the specific structure of the model. The benchmark economy consists of a flexible-price energy sector and a sticky-price manufacturing sector where energy is used as an intermediate input. We show that optimal policy is to stabilize the sticky (core) price level. We then show that after incorporating a less oil-dependent sticky-price service sector, the model exhibits a trade-off in stabilizing prices and output gaps in the different sticky-price sectors. It predicts that central bank should not try to stabilize the core price level, and the economy will experience higher inflation and rising output gaps, even if central banks respond optimally. Chapter 2 addresses the observed volatility and persistence of real exchange rates and the terms of trade. It contributes to the literature with a quantitative study on the U.S. and Canada. A two-country New Keynesian model consisting of traded, non-traded, and oil production sectors is proposed to examine the time series properties of the real exchange rate, the terms of trade and the real oil price. We find that after incorporating several realistic features (namely oil price shocks, sector specific labor, non-traded goods, asymmetric pricing decisions of exporters and asymmetric consumer preferences over tradables), the benchmark model broadly matches the volatilities of the relative prices and some business cycle correlations. The model matches the data more closely after adding real demand shocks, suggesting their importance in explaining the relative price movements between the US and Canada. Chapter 3 explores several sources and transmission channels of international relative price movements. In particular, we elaborate on the role of

  20. The indirect costs of back problems (dorsopathies) in Australians aged 45 to 64 years from 2015 to 2030: results from a microsimulation model, Health&WealthMOD2030.

    Science.gov (United States)

    Schofield, Deborah; Cunich, Michelle M; Shrestha, Rupendra N; Tanton, Robert; Veerman, Lennert; Kelly, Simon J; Passey, Megan E

    2016-12-01

    This study projected the indirect costs of back problems through lost productive life years (PLYs) from the individual's perspective (lost disposable income), the governmental perspective (reduced taxation revenue, greater welfare spending), and the societal perspective (lost gross domestic product, GDP) from 2015 to 2030, using Health&WealthMOD2030-Australia's first microsimulation model on the long-term impacts of ill-health. Quantile regression analysis was used to examine differences in median weekly income, welfare payments, and taxes of people unable to work due to back problems with working full-time without back problems as comparator. National costs and lost GDP resulting from missing workers due to back problems were also projected. We projected that 90,000 people have lost PLYs due to back problems in 2015, increasing to 104,600 in 2030 (16.2% increase). People with lost PLYs due to back problems are projected to receive AU$340.91 less in total income and AU$339.77 more in welfare payments per week than full-time workers without back problems in 2030 and pay no income tax on average. National costs consisted of a loss of AU$2931 million in annual income in 2015, increasing to AU$4660 million in 2030 (60% increase). For government, extra annual welfare payments are projected to increase from AU$1462 million in 2015 to AU$1709 million in 2030 (16.9% increase), and lost annual taxation revenue to increase from AU$671 million in 2015 to $961 million in 2030 (43.2% increase). We projected losses in GDP of AU$10,543 million in 2015, increasing to AU$14,522 million in 2030 due to back problems.

  1. A Connection Model between the Positioning Mechanism and Ultrasonic Measurement System via a Web Browser to Assess Acoustic Target Strength

    Science.gov (United States)

    Ishii, Ken; Imaizumi, Tomohito; Abe, Koki; Takao, Yoshimi; Tamura, Shuko

    This paper details a network-controlled measurement system for use in fisheries engineering. The target strength (TS) of fish is important in order to convert acoustic integration values obtained during acoustic surveys into estimates of fish abundance. The target strength pattern is measured with the combination of the rotation system for the aspect of the sample and the echo data acquisition system using the underwater supersonic wave. The user interface of the network architecture is designed for collaborative use with researchers in other organizations. The flexible network architecture is based on the web direct-access model for the rotation mechanism. The user interface is available for monitoring and controlling via a web browser that is installed in any terminal PC (personal computer). Previously the combination of two applications was performed not by a web browser but by the exclusive interface program. So a connection model is proposed between two applications by indirect communication via the DCOM (Distributed Component Object Model) server and added in the web direct-access model. A prompt report system in the TS measurement system and a positioning and measurement system using an electric flatcar via a web browser are developed. By a secure network architecture, DCOM communications via both Intranet and LAN are successfully certificated.

  2. An approximation of herd effect due to vaccinating children against seasonal influenza – a potential solution to the incorporation of indirect effects into static models

    Directory of Open Access Journals (Sweden)

    Van Vlaenderen Ilse

    2013-01-01

    Full Text Available Abstract Background Indirect herd effect from vaccination of children offers potential for improving the effectiveness of influenza prevention in the remaining unvaccinated population. Static models used in cost-effectiveness analyses cannot dynamically capture herd effects. The objective of this study was to develop a methodology to allow herd effect associated with vaccinating children against seasonal influenza to be incorporated into static models evaluating the cost-effectiveness of influenza vaccination. Methods Two previously published linear equations for approximation of herd effects in general were compared with the results of a structured literature review undertaken using PubMed searches to identify data on herd effects specific to influenza vaccination. A linear function was fitted to point estimates from the literature using the sum of squared residuals. Results The literature review identified 21 publications on 20 studies for inclusion. Six studies provided data on a mathematical relationship between effective vaccine coverage in subgroups and reduction of influenza infection in a larger unvaccinated population. These supported a linear relationship when effective vaccine coverage in a subgroup population was between 20% and 80%. Three studies evaluating herd effect at a community level, specifically induced by vaccinating children, provided point estimates for fitting linear equations. The fitted linear equation for herd protection in the target population for vaccination (children was slightly less conservative than a previously published equation for herd effects in general. The fitted linear equation for herd protection in the non-target population was considerably less conservative than the previously published equation. Conclusions This method of approximating herd effect requires simple adjustments to the annual baseline risk of influenza in static models: (1 for the age group targeted by the childhood vaccination strategy

  3. Attributing greenhouse gas emissions associated with land use and land use change to direct and indirect human and natural drivers: a modelling study to estimate their relative importance.

    Science.gov (United States)

    Hastings, Astley; Abdalla, Mohamed; Bell, Madeleine; Blagodatskiy, Sergey; Datta, Arindam; Dondini, Marta; Fitton, Nuala; Jones, Ed; Klumpp, Katja; Nemoto, Rie; Richards, Mark; Yeluripati, Jagadeesh; Smith, Pete

    2013-04-01

    Since humans cultivated crops, domesticated livestock and exploited woods and grasslands they have directly changed land use. In Europe, most of the landscapes are anthropogenically influenced. Each land use will have its carbon stock in the soil and vegetation that will depend on the geography, parent material of the soil, the climate and its land use history. For each land use and cover the soil carbon stock will reach a steady state where the rate of decomposition of the soil carbon is balanced by the organic material input each year. Each type of vegetation will reach a steady state depending on the length of its plants life cycle; for annual plants it is months, perennial grasslands it is years and for forest it is decades or centuries. In addition, the management of the crops, grasses or trees can be intensive, where the maximum vegetation is harvested or grazed, or extensive, when part of the plant material is left as a soil input. Net carbon flux will depend on the carbon balance between photosynthesis and respiration. Methane flux will mainly depend of the water content and redox potential of the soil and nitrous oxide emissions will depend of the type and amount of nitrogen input, pH and the relative timing of rainfall events, as well as the climatic conditions. In his study we have used site experiments to parameterize ecosystem models such as ECOSSE, DAYCENT, PASIM and DNDC on sites where there were more than one land use treatment to investigate the relative impact of human direct and indirect drivers compared to natural ones. Once the models have been parameterized the drivers to be investigated are systematically changed. The land uses investigated are grassland, forest, peatland and cropland. The direct drivers investigated are land use change (from cropland and grassland to bioenergy grasses, cropland to grassland and forest) and management change from intensive to extensive and vice versa. The management drivers investigated include tillage

  4. Nonlinear Mathematical Modeling in Pneumatic Servo Position Applications

    Directory of Open Access Journals (Sweden)

    Antonio Carlos Valdiero

    2011-01-01

    Full Text Available This paper addresses a new methodology for servo pneumatic actuators mathematical modeling and selection from the dynamic behavior study in engineering applications. The pneumatic actuator is very common in industrial application because it has the following advantages: its maintenance is easy and simple, with relatively low cost, self-cooling properties, good power density (power/dimension rate, fast acting with high accelerations, and installation flexibility. The proposed fifth-order nonlinear mathematical model represents the main characteristics of this nonlinear dynamic system, as servo valve dead zone, air flow-pressure relationship through valve orifice, air compressibility, and friction effects between contact surfaces in actuator seals. Simulation results show the dynamic performance for different pneumatic cylinders in order to see which features contribute to a better behavior of the system. The knowledge of this behavior allows an appropriate choice of pneumatic actuator, mainly contributing to the success of their precise control in several applications.

  5. Positivity in Lorentzian Barrett-Crane Models of Quantum Gravity

    CERN Document Server

    Cherrington, J W

    2006-01-01

    The Barrett-Crane models of Lorentzian quantum gravity are a family of spin foam models based on the Lorentz group. We show that for various choices of edge and face amplitudes, including the Perez-Rovelli normalization, the amplitude for every triangulated closed 4-manifold is a non-negative real number. Roughly speaking, this means that if one sums over triangulations, there is no interference between the different triangulations. We prove non-negativity by transforming the model into a ``dual variables'' formulation in which the amplitude for a given triangulation is expressed as an integral over three copies of hyperbolic space for each tetrahedron. Then we prove that, expressed in this way, the integrand is non-negative. In addition to implying that the amplitude is non-negative, the non-negativity of the integrand is highly significant from the point of view of numerical computations, as it allows statistical methods such as the Metropolis algorithm to be used for efficient computation of expectation va...

  6. Indirect combustion noise of auxiliary power units

    Science.gov (United States)

    Tam, Christopher K. W.; Parrish, Sarah A.; Xu, Jun; Schuster, Bill

    2013-08-01

    Recent advances in noise suppression technology have significantly reduced jet and fan noise from commercial jet engines. This leads many investigators in the aeroacoustics community to suggest that core noise could well be the next aircraft noise barrier. Core noise consists of turbine noise and combustion noise. There is direct combustion noise generated by the combustion processes, and there is indirect combustion noise generated by the passage of combustion hot spots, or entropy waves, through constrictions in an engine. The present work focuses on indirect combustion noise. Indirect combustion noise has now been found in laboratory experiments. The primary objective of this work is to investigate whether indirect combustion noise is also generated in jet and other engines. In a jet engine, there are numerous noise sources. This makes the identification of indirect combustion noise a formidable task. Here, our effort concentrates exclusively on auxiliary power units (APUs). This choice is motivated by the fact that APUs are relatively simple engines with only a few noise sources. It is, therefore, expected that the chance of success is higher. Accordingly, a theoretical model study of the generation of indirect combustion noise in an Auxiliary Power Unit (APU) is carried out. The cross-sectional areas of an APU from the combustor to the turbine exit are scaled off to form an equivalent nozzle. A principal function of a turbine in an APU is to extract mechanical energy from the flow stream through the exertion of a resistive force. Therefore, the turbine is modeled by adding a negative body force to the momentum equation. This model is used to predict the ranges of frequencies over which there is a high probability for indirect combustion noise generation. Experimental spectra of internal pressure fluctuations and far-field noise of an RE220 APU are examined to identify anomalous peaks. These peaks are possible indirection combustion noise. In the case of the

  7. Semi-analytical modelling of positive corona discharge in air

    Science.gov (United States)

    Pontiga, Francisco; Yanallah, Khelifa; Chen, Junhong

    2013-09-01

    Semianalytical approximate solutions of the spatial distribution of electric field and electron and ion densities have been obtained by solving Poisson's equations and the continuity equations for the charged species along the Laplacian field lines. The need to iterate for the correct value of space charge on the corona electrode has been eliminated by using the corona current distribution over the grounded plane derived by Deutsch, which predicts a cos m θ law similar to Warburg's law. Based on the results of the approximated model, a parametric study of the influence of gas pressure, the corona wire radius, and the inter-electrode wire-plate separation has been carried out. Also, the approximate solutions of the electron number density has been combined with a simplified plasma chemistry model in order to compute the ozone density generated by the corona discharge in the presence of a gas flow. This work was supported by the Consejeria de Innovacion, Ciencia y Empresa (Junta de Andalucia) and by the Ministerio de Ciencia e Innovacion, Spain, within the European Regional Development Fund contracts FQM-4983 and FIS2011-25161.

  8. Estimation of Indirect Effects in the Presence of Unmeasured Confounding for the Mediator-Outcome Relationship in a Multilevel 2-1-1 Mediation Model

    Science.gov (United States)

    Talloen, Wouter; Moerkerke, Beatrijs; Loeys, Tom; De Naeghel, Jessie; Van Keer, Hilde; Vansteelandt, Stijn

    2016-01-01

    To assess the direct and indirect effect of an intervention, multilevel 2-1-1 studies with intervention randomized at the upper (class) level and mediator and outcome measured at the lower (student) level are frequently used in educational research. In such studies, the mediation process may flow through the student-level mediator (the within…

  9. The calculation of indirect nuclear spin-spin coupling constants in large molecules.

    Science.gov (United States)

    Watson, Mark A; Sałek, Paweł; Macak, Peter; Jaszuński, Michał; Helgaker, Trygve

    2004-09-20

    We present calculations of indirect nuclear spin-spin coupling constants in large molecular systems, performed using density functional theory. Such calculations, which have become possible because of the use of linear-scaling techniques in the evaluation of the Coulomb and exchange-correlation contributions to the electronic energy, allow us to study indirect spin-spin couplings in molecules of biological interest, without having to construct artificial model systems. In addition to presenting a statistical analysis of the large number of short-range coupling constants in large molecular systems, we analyse the asymptotic dependence of the indirect nuclear spin-spin coupling constants on the internuclear separation. In particular, we demonstrate that, in a sufficiently large one-electron basis set, the indirect spin-spin coupling constants become proportional to the inverse cube of the internuclear separation, even though the diamagnetic and paramagnetic spin-orbit contributions to the spin-spin coupling constants separately decay as the inverse square of this separation. By contrast, the triplet Fermi contact and spin-dipole contributions to the indirect spin-spin coupling constants decay exponentially and as the inverse cube of the internuclear separation, respectively. Thus, whereas short-range indirect spin-spin coupling constants are usually dominated by the Fermi contact contribution, long-range coupling constants are always dominated by the negative diamagnetic spin-orbit contribution and by the positive paramagnetic spin-orbit contribution, with small spin-dipole and negligible Fermi contact contributions.

  10. Direct and indirect punishment among strangers in the field.

    Science.gov (United States)

    Balafoutas, Loukas; Nikiforakis, Nikos; Rockenbach, Bettina

    2014-11-11

    Many interactions in modern human societies are among strangers. Explaining cooperation in such interactions is challenging. The two most prominent explanations critically depend on individuals' willingness to punish defectors: In models of direct punishment, individuals punish antisocial behavior at a personal cost, whereas in models of indirect reciprocity, they punish indirectly by withholding rewards. We investigate these competing explanations in a field experiment with real-life interactions among strangers. We find clear evidence of both direct and indirect punishment. Direct punishment is not rewarded by strangers and, in line with models of indirect reciprocity, is crowded out by indirect punishment opportunities. The existence of direct and indirect punishment in daily life indicates the importance of both means for understanding the evolution of cooperation.

  11. Analysis of methods and models for assessing the direct and indirect economic impacts of CO/sub 2/-induced environmental changes in the agricultural sector of the US economy

    Energy Technology Data Exchange (ETDEWEB)

    Callaway, J.M.

    1982-08-01

    Alternative methods for quantifying the economic impacts associated with future increases in the ambient concentration of CO/sub 2/ were examined. A literature search was undertaken, both to gain a better understanding of the ways in which CO/sub 2/ buildup could affect crop growth and to identify the different methods available for assessing the impacts of CO/sub 2/-induced environmental changes on crop yields. The second task involved identifying the scope of both the direct and indirect economic impacts that could occur as a result of CO/sub 2/-induced changes in crop yields. The third task then consisted of a comprehensive literature search to identify what types of economic models could be used effectively to assess the kinds of direct and indirect economic impacts that could conceivably occur as a result of CO/sub 2/ buildup. Specific attention was focused upon national and multi-regional agricultural sector models, multi-country agricultural trade models, and macroeconomic models of the US economy. The fourth and final task of this research involved synthesizing the information gathered in the previous tasks into a systematic framework for assessing the direct and indirect economic impacts of CO/sub 2/-induced environmental changes related to agricultural production.

  12. Gender differentiation of indirect self-destructiveness

    Directory of Open Access Journals (Sweden)

    Konstantinos Tsirigotis

    2013-02-01

    Full Text Available Objectives: The objective of this study was to examine the sex (gender differentiation of indirect self-destructiveness intensity and its manifestations, as well as relationships between indirect self-destructiveness and its manifestations (categories and the psychological dimensions of masculinity and femininity, also from the point of view of assessing occupational health and safety. Materials and Methods: A population of 558 individuals (399 females and 159 males aged 19–25 (mean age: 22.6 was studied. The Polish version of the “Chronic Self-Destructiveness Scale” (CS-DS by Kelley adapted by Suchańska was used in order to examine indirect self-destructiveness and its manifestations. Gender testing applied the Polish version of the Bem Sex Role Inventory (BSRI by Bem in its adaptation by Kuczyńska. Results: Males’ scores are signifi cantly higher than those of females for the majority of CS-DS scales/indices: Indirect Self-Destructiveness (general index, Poor Health Maintenance (A2, Lack of Planfulness (A4, and Helplessness, Passiveness (A5. Moreover, there are statistically signifi cant correlations between CS-DS scales and the masculinity dimension (positive as well as the femininity dimension (negative. Conclusions: Masculinity is a factor that may predispose towards indirectly self-destructive behaviors, while femininity is a factor protecting against those. The study results may prove useful in preventing indirectly and directly self-destructive behaviors as well as in therapy work with the individuals who display such tendencies or have made attempts on their own lives, in particular taking into account their being of a specifi c sex/gender and in the context of work (especially in diffi cult or dangerous conditions or both.

  13. On the interest of positive degree day models for mass balance modeling in the inner tropics

    Directory of Open Access Journals (Sweden)

    L. Maisincho

    2014-05-01

    Full Text Available A positive degree-day (PDD model was tested on Antizana Glacier 15α (0.28 km2; 0°28' S, 78°09' W to assess to what extent this approach is suitable for studying glacier mass balance in the inner tropics. Cumulative positive temperatures were compared with field measurements of melting amount and with surface energy balance computations. A significant link was revealed when a distinction was made between the snow and ice comprising the glacier surface. Significant correlations allowed degree-day factors to be retrieved for snow, and clean and dirty ice. The relationship between melt amount and temperature was mainly explained by the role of net shortwave radiation in both melting and in the variations in the temperature of the surface layer. However, this relationship disappeared from June to October (Period 1, because high wind speeds and low humidity cause highly negative turbulent latent heat fluxes. However, this had little impact on the computed total amount of melting at the annual time scale because temperatures are low and melting is generally limited during Period 1. At the daily time scale, melting starts when daily temperature means are still negative, because around noon incoming shortwave radiation is very high, and compensates for energy losses when the air is cold. The PDD model was applied to the 2000–2008 period using meteorological inputs measured on the glacier foreland. Results were compared to the glacier-wide mass balances measured in the field and were good, even though the melting factor should be adapted to the glacier surface state and may vary with time. Finally, the model was forced with precipitation and temperature data from the remote Izobamba station and NCEP-NCAR reanalysis data, also giving good results and showing that temperature variations are homogenous at the regional scale, meaning glacier mass balances can be modelled over large areas.

  14. Analysis of methods and models for assessing the direct and indirect economic impacts of CO/sub 2/-induced environmental changes in the agricultural sector of the US economy

    Energy Technology Data Exchange (ETDEWEB)

    Callaway, J.M.; Cronin, F.J.; Currie, J.W.; Tawil, J.

    1982-08-01

    The overall purpose of this research was to assist the US Department of Energy (DOE) in developing methods for assessing the direct and indirect economic impacts due to the effects of increases in the ambient concentration of CO/sub 2/ on agricultural production. First, a comprehensive literature search was undertaken to determine what types of models and methods have been developed, which could be effectively used to conduct assessments of the direct and indirect economic impacts of CO/sub 2/ buildup. Specific attention was focused upon models and methods for assessing the physical impacts of CO/sub 2/-induced environmental changes on crop yields; national and multi-regional agricultural sector models; and macroeconomic models of the US economy. The second task involved a thorough investigation of the research efforts being conducted by other public and private sector organizations in order to determine how more recent analytical methods being developed outside of DOE could be effectively integrated into a more comprehensive analysis of the direct economic impacts of CO/sub 2/ buildup. The third and final task involved synthesizing the information gathered in the first two tasks into a systematic framework for assessing the direct and indirect economic impacts of CO/sub 2/-induced environmental changes originating in the agricultural sector of the US economy. It is concluded that the direct economic impacts of CO/sub 2/ on the agricultural sector and the indirect economic impacts caused by spillover effects from agriculture to other sectors of the economy will be pervasive; however, the direction and magnitude of these impacts on producers and consumers cannot be determined a priori.

  15. A Preventative Model of School Consultation: Incorporating Perspectives from Positive Psychology

    Science.gov (United States)

    Akin-Little, K. Angeleque; Little, Steven G.; Delligatti, Nina

    2004-01-01

    Using the principles of mental health and behavioral consultation, combined with concepts from positive psychology, this paper generates a new preventative model of school consultation. This model has two steps: (1) the school psychologist aids the teacher in the development and use of his/her personal positive psychology (e.g., optimism,…

  16. NON-CONSTANT POSITIVE STEADY-STATES OF A PREDATOR-PREY-MUTUALIST MODEL

    Institute of Scientific and Technical Information of China (English)

    CHEN WENYAN; WANG MINGXIN

    2004-01-01

    In this paper, the authors deal with the non-constant positive steady-states of a predator-prey-mutualist model with homogeneous Neumann boundary condition. They first give a priori estimates (positive upper and lower bounds) of positive steady-states,and then study the non-existence, the global existence and bifurcation of non-constant positive steady-states as some parameters are varied. Finally the asymptotic behavior of such solutions as d3 →∞ is discussed.

  17. Dark matter dynamics and indirect detection

    Energy Technology Data Exchange (ETDEWEB)

    Bertone, Gianfranco; /Fermilab; Merritt, David; /Rochester Inst. Tech.

    2005-04-01

    Non-baryonic, or ''dark'', matter is believed to be a major component of the total mass budget of the universe. We review the candidates for particle dark matter and discuss the prospects for direct detection (via interaction of dark matter particles with laboratory detectors) and indirect detection (via observations of the products of dark matter self-annihilations), focusing in particular on the Galactic center, which is among the most promising targets for indirect detection studies. The gravitational potential at the Galactic center is dominated by stars and by the supermassive black hole, and the dark matter distribution is expected to evolve on sub-parsec scales due to interaction with these components. We discuss the dominant interaction mechanisms and show how they can be used to rule out certain extreme models for the dark matter distribution, thus increasing the information that can be gleaned from indirect detection searches.

  18. Indirect taxes on food in Southern Brazil

    Directory of Open Access Journals (Sweden)

    Denize Mirian da Silva

    2013-12-01

    Full Text Available The objective of this paper is to estimate the indirect tax burden on food for ten income classes, based on income and household total expenditure in southern Brazil. Thus it can be seen as indirect taxes on foods affect the monetary income and consumption pattern of households. To reach the objectives proposed, will be used the Pintos-Payeras (2008 model. The database iscomposed by microdata from the Household Budgeting Survey (POF 2008-2009 and the tax regulations of the country and the southern states of Brazil. The results show that indirect taxes on food in Southern Brazil is regressive when based on income and expenditure of household , ie , the poorest people pay proportionately more taxes and have their consumption pattern highest taxed ICMS (Brazilian value added tax is the tax that contributes most to the regressivity.

  19. Model Estimates Of Gross Domestic Product In Relation to Export And Import Of Fuels, Focused on the Elasticity and Determination Of Directly and Indirectly Associated Rates

    Directory of Open Access Journals (Sweden)

    Gheorghe Săvoiu

    2016-03-01

    Full Text Available The article is based on several interrogative assumptions related to the positive impact of the crises and the recession on determinations in the econometric models of Romania’s GDP as a variable dependent in relation to the export and import of fuels. After a short introductory section, which details, in a relative manner, the overall goal and the objectives of the paper, a first section makes use of elasticity and the modern solutions of building the coefficient of elasticity, proposing an original alternative to existing variants, and afterwards the next section builds on these statistical tools in the econometric modeling of Romania’s GDP, starting from the ratios and value indicators and offering a few original models where the export and import of fuels are the key initial explanatory factors. The final remarks reinterpret the role of the energy resources, as well as that of the related flows, in enhancing statistical connections, and especially the role of crises and recessions in validating econometric models, by raising their degree of predictability.

  20. Known unknowns: indirect energy effects of information and communication technology

    Science.gov (United States)

    Horner, Nathaniel C.; Shehabi, Arman; Azevedo, Inês L.

    2016-10-01

    Background. There has been sustained and growing interest in characterizing the net energy impact of information and communication technology (ICT), which results from indirect effects offsetting (or amplifying) the energy directly consumed by ICT equipment. These indirect effects may be either positive or negative, and there is considerable disagreement as to the direction of this sign as well as the effect magnitude. Literature in this area ranges from studies focused on a single service (such as e-commerce versus traditional retail) to macroeconomic studies attempting to characterize the overall impact of ICT. Methods. We review the literature on the indirect energy effect of ICT found via Google Scholar, our own research, and input from other researchers in the field. The various studies are linked to an effect taxonomy, which is synthesized from several different hierarchies present in the literature. References are further grouped according to ICT service (e.g., e-commerce, telework) and summarized by scope, method, and quantitative and qualitative findings. Review results. Uncertainty persists in understanding the net energy effects of ICT. Results of indirect energy effect studies are highly sensitive to scoping decisions and assumptions made by the analyst. Uncertainty increases as the impact scope broadens, due to complex and interconnected effects. However, there is general agreement that ICT has large energy savings potential, but that the realization of this potential is highly dependent on deployment details and user behavior. Discussion. While the overall net effect of ICT is likely to remain unknown, this review suggests several guidelines for improving research quality in this area, including increased data collection, enhancing traditional modeling studies with sensitivity analysis, greater care in scoping, less confidence in characterizing aggregate impacts, more effort on understanding user behavior, and more contextual integration across the

  1. Positive life events, attributional style, and hopefulness: testing a model of recovery from depression.

    Science.gov (United States)

    Needles, D J; Abramson, L Y

    1990-05-01

    A model of a recovery process from depression that is compatible with the hopelessness theory of depressive onset is proposed. This model predicts that depressives who have an enhancing attributional style for positive events (i.e., make global, stable attributions for such events) will be more likely to regain hopefulness and, thereby, recover from depression, when positive events occur. This prediction was tested by following a group of depressed college students longitudinally for 6 weeks. Although neither positive events alone nor attributional style alone predicted reduction in hopelessness, depressives who both showed the enhancing attributional style for positive events and experienced more positive events showed dramatic reductions in hopelessness which were accompanied by remission of depressive symptoms. Thus, attributional style for positive events may be a factor that enables some depressives to recover when positive events occur in their lives.

  2. Rear seat child safety in near-side impacts: a modeling study of common sitting positions.

    Science.gov (United States)

    Andersson, Marianne; Pipkorn, Bengt; Lövsund, Per

    2013-01-01

    The purpose of this study was to evaluate and propose improvements to the injury mitigation systems, in near-side impacts, for 6 common sitting positions of young adolescents using a previously validated model. The evaluation was made by using a model of a complete passenger car, including head and thorax-pelvis air bags, which was impacted laterally by a barrier in 2 load cases. The SID-IIs finite element model was used for the evaluations and was seated in 6 different positions in the rear outboard seat: the nominal anthropomorphic test device (ATD) position, 1 inboard position, 3 outboard positions, and 1 braking (forward) position. These positions have previously been identified as common sitting positions in awake and asleep children. The studied dependent variables were head injury criterion (HIC) 36, resultant head linear acceleration, resultant head rotational acceleration, chest viscous criterion, and chest deflection. The lowest head injury measures were seen in the braking positions and in the nominal ATD position, and the highest were seen in the inboard and outboard positions. The lowest chest injury measures were recorded in the inboard and nominal ATD positions, and the highest were recorded in the outboard and braking positions. The occupant in the outboard positions interfered with the air bags during their deployment. The occupant in inboard and braking positions tended to push the curtain air bag over the windowsill. Studies that investigate the injury mitigation effects in common sitting positions, beyond the nominal ATD position, are essential to highlight means to provide improved and robust safety for child occupants. This study was based on the SID-IIs 5th percentile female, which has very similar anthropometry to a 50th percentile 12-year-old. Therefore, the conclusions of this study are applicable to many 11-year-olds up to young adolescents, as well as to small females. The outboard and inboard positions of this study resulted in the

  3. Experimental calibration of the mathematical model of Air Torque Position dampers with non-cascading blades

    OpenAIRE

    Bikić Siniša M.; Uzelac Dušan N.; Bukurov Maša Ž.; Radojčin Milivoj T.; Pavkov Ivan S.

    2016-01-01

    This paper is focused on the mathematical model of the Air Torque Position dampers. The mathematical model establishes a link between the velocity of air in front of the damper, position of the damper blade and the moment acting on the blade caused by the air flow. This research aims to experimentally verify the mathematical model for the damper type with non-cascading blades. Four different types of dampers with non-cascading blades were considered: single...

  4. Assessment Model of Atmosphere Transmitting Influence on High-resolution Airborne SAR Stereo Positioning

    Institute of Scientific and Technical Information of China (English)

    ZHENG Zhaoqing; PANG Lei; CHEN Xuexing

    2008-01-01

    The influence derived from atmosphere transmitting of radar wave, in the application of high-resolution airborne Synthetic Aperture Radar (SAR) stereo positioning, may produce some phase errors, and eventually be intro-duced into positioning model. This paper described the principle of airborne SAR stereo positioning and the error sources of stereo positioning accuracy that arose from atmosphere transmitting, established a corresponding assess-ment model of atmosphere transmitting influence, and testified the model and the assessment principle taking the 1-m resolution airborne SAR images of Zigong City, Sichuan Province in China, as the test dataset. The test result has proved that the assessment model is reliable and reasonable. And, it has shown that the phase error arisen from time delay is the main error source during the atmosphere transmitting, which has much more influences on cross-track di-rection and introduces a stereo positioning error of about eight meters, but less on the along-track direction.

  5. Modeling and Compensation of Thermal Effects on an Ironless Inductive Position Sensor

    CERN Document Server

    Danisi, Alessandro; Losito, Roberto; Perriard, Yves

    2014-01-01

    The ironless inductive position sensor can be the ideal candidate for linear position sensing in harsh environment and in the presence of external magnetic fields. Starting from the validated electromagnetic characteristics, this paper presents a model of thermal effects influencing the sensor's position reading and an effective algorithm to compensate them. The compensation is performed without affecting the nominal sensor's functioning and without using additional temperature probes, which would complicate the sensor's assembly. The model constitutes the basis of this algorithm, which is then validated through experimental measurements on a custom ironless position sensor prototype.

  6. Optimal cycling time trial position models: aerodynamics versus power output and metabolic energy.

    Science.gov (United States)

    Fintelman, D M; Sterling, M; Hemida, H; Li, F-X

    2014-06-03

    The aerodynamic drag of a cyclist in time trial (TT) position is strongly influenced by the torso angle. While decreasing the torso angle reduces the drag, it limits the physiological functioning of the cyclist. Therefore the aims of this study were to predict the optimal TT cycling position as function of the cycling speed and to determine at which speed the aerodynamic power losses start to dominate. Two models were developed to determine the optimal torso angle: a 'Metabolic Energy Model' and a 'Power Output Model'. The Metabolic Energy Model minimised the required cycling energy expenditure, while the Power Output Model maximised the cyclists׳ power output. The input parameters were experimentally collected from 19 TT cyclists at different torso angle positions (0-24°). The results showed that for both models, the optimal torso angle depends strongly on the cycling speed, with decreasing torso angles at increasing speeds. The aerodynamic losses outweigh the power losses at cycling speeds above 46km/h. However, a fully horizontal torso is not optimal. For speeds below 30km/h, it is beneficial to ride in a more upright TT position. The two model outputs were not completely similar, due to the different model approaches. The Metabolic Energy Model could be applied for endurance events, while the Power Output Model is more suitable in sprinting or in variable conditions (wind, undulating course, etc.). It is suggested that despite some limitations, the models give valuable information about improving the cycling performance by optimising the TT cycling position.

  7. Indirect Coupling between Two Cavity Photon Systems via Ferromagnetic Resonance

    CERN Document Server

    Hyde, Paul; Harder, Michael; Match, Christophe; Hu, Can-Ming

    2016-01-01

    We experimentally realize indirect coupling between two cavity modes via strong coupling with the ferromagnetic resonance in Yttrium Iron Garnet (YIG). We find that some indirectly coupled modes of our system can have a higher microwave transmission than the individual uncoupled modes. Using a coupled harmonic oscillator model, the influence of the oscillation phase difference between the two cavity modes on the nature of the indirect coupling is revealed. These indirectly coupled microwave modes can be controlled using an external magnetic field or by tuning the cavity height. This work has potential for use in controllable optical devices and information processing technologies.

  8. Quantifying Direct and Indirect Effects of Elevated CO2 on Ecosystem Response

    Science.gov (United States)

    Fatichi, S.; Leuzinger, S.; Paschalis, A.; Donnellan-Barraclough, A.; Hovenden, M. J.; Langley, J. A.

    2015-12-01

    Increasing concentrations of atmospheric carbon dioxide are expected to affect carbon assimilation, evapotranspiration (ET) and ultimately plant growth. Direct leaf biochemical effects have been widely investigated, while indirect effects, although documented, are very difficult to quantify in experiments. We hypothesize that the interaction of direct and indirect effects is a possible reason for conflicting results concerning the magnitude of CO2 fertilization effects across different climates and ecosystems. A mechanistic ecohydrological model (Tethys-Chloris) is used to investigate the relative contribution of direct (through plant physiology) and indirect (via stomatal closure and thus soil moisture, and changes in Leaf Area Index, LAI) effects of elevated CO2 across a number of ecosystems. We specifically ask in which ecosystems and climate indirect effects are expected to be largest. Data and boundary conditions from flux-towers and free air CO2 enrichment (FACE) experiments are used to force the model and evaluate its performance. Numerical results suggest that indirect effects of elevated CO2, through water savings and increased LAI, are very significant and sometimes larger than direct effects. Indirect effects tend to be considerably larger in water-limited ecosystems, while direct effects correlate positively with mean air temperature. Increasing CO2 from 375 to 550 ppm causes a total effect on Net Primary Production in the order of 15 to 40% and on ET from 0 to -8%, depending on climate and ecosystem type. The total CO2 effect has a significant negative correlation with the wetness index and positive correlation with vapor pressure deficit. These results provide a more general mechanistic understanding of relatively short-term (less than 20 years) implications of elevated CO2 on ecosystem response and suggest plausible magnitudes for the expected changes.

  9. Mitigating Errors in External Respiratory Surrogate-Based Models of Tumor Position

    Energy Technology Data Exchange (ETDEWEB)

    Malinowski, Kathleen T. [Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD (United States); Fischell Department of Bioengineering, University of Maryland, College Park, MD (United States); McAvoy, Thomas J. [Fischell Department of Bioengineering, University of Maryland, College Park, MD (United States); Department of Chemical and Biomolecular Engineering and Institute of Systems Research, University of Maryland, College Park, MD (United States); George, Rohini [Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD (United States); Dieterich, Sonja [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA (United States); D' Souza, Warren D., E-mail: wdsou001@umaryland.edu [Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD (United States); Fischell Department of Bioengineering, University of Maryland, College Park, MD (United States)

    2012-04-01

    Purpose: To investigate the effect of tumor site, measurement precision, tumor-surrogate correlation, training data selection, model design, and interpatient and interfraction variations on the accuracy of external marker-based models of tumor position. Methods and Materials: Cyberknife Synchrony system log files comprising synchronously acquired positions of external markers and the tumor from 167 treatment fractions were analyzed. The accuracy of Synchrony, ordinary-least-squares regression, and partial-least-squares regression models for predicting the tumor position from the external markers was evaluated. The quantity and timing of the data used to build the predictive model were varied. The effects of tumor-surrogate correlation and the precision in both the tumor and the external surrogate position measurements were explored by adding noise to the data. Results: The tumor position prediction errors increased during the duration of a fraction. Increasing the training data quantities did not always lead to more accurate models. Adding uncorrelated noise to the external marker-based inputs degraded the tumor-surrogate correlation models by 16% for partial-least-squares and 57% for ordinary-least-squares. External marker and tumor position measurement errors led to tumor position prediction changes 0.3-3.6 times the magnitude of the measurement errors, varying widely with model algorithm. The tumor position prediction errors were significantly associated with the patient index but not with the fraction index or tumor site. Partial-least-squares was as accurate as Synchrony and more accurate than ordinary-least-squares. Conclusions: The accuracy of surrogate-based inferential models of tumor position was affected by all the investigated factors, except for the tumor site and fraction index.

  10. The effect of position sources on estimated eigenvalues in intensity modeled data

    NARCIS (Netherlands)

    Hendrikse, Anne; Veldhuis, Raymond; Spreeuwers, Luuk; Goseling, Jasper; Weber, Jos H.

    2010-01-01

    In biometrics, often models are used in which the data distributions are approximated with normal distributions. In particular, the eigenface method models facial data as a mixture of fixed-position intensity signals with a normal distribution. The model parameters, a mean value and a covariance mat

  11. A characterization of edge reflection positive partition functions of vertex coloring models

    NARCIS (Netherlands)

    G. Regts (Guus)

    2013-01-01

    htmlabstractSzegedy (B. Szegedy, Edge coloring models and reflection positivity, Journal of the American Mathematical Society 20, 2007, 969-988.) showed that the partition function of any vertex coloring model is equal to the partition function of a complex edge coloring model. Using some results in

  12. A characterization of edge-reflection positive partition functions of vertex-coloring models

    NARCIS (Netherlands)

    G. Regts (Guus); J. Nešetřil (Jaroslav); M Pellegrini

    2013-01-01

    htmlabstractSzegedy (B. Szegedy, Edge coloring models and reflection positivity, Journal of the American Mathematical Society 20, 2007, 969-988.) showed that the partition function of any vertex coloring model is equal to the partition function of a complex edge coloring model. Using some results in

  13. Using HEC-FIA to identify Indirect Economic Losses

    Directory of Open Access Journals (Sweden)

    Lehman William

    2016-01-01

    This paper will describe how HEC-FIA can be utilized to help evaluate the indirect economic consequences for various alternatives within a floodplain. The computational methods for indirect economic losses utilize a Computable General Equilibrium model to describe the secondary and tertiary impacts of loss of service, loss of laborers, and reductions in demand for intermediary goods.

  14. Direct and indirect mate choice on leks.

    Science.gov (United States)

    Saether, Stein Are; Baglo, Ragnhild; Fiske, Peder; Ekblom, Robert; Höglund, Jacob; Kålås, John Atle

    2005-08-01

    Indirect mate choice is any behavior that restricts the individual's set of potential mates without discrimination of mate attributes directly, for example, by having preferences about where to mate. We analyzed a 14-year data set from great snipe (Gallinago media) leks for evidence of indirect mate choice based on relative and absolute position of lek territories. We found little or no effect of the centrality of territories on mating and no between-year consistency in the spatial distribution of matings within leks. Instead, the probability of matings occurring at a particular site increased if the current territory owner had mated the previous year. Furthermore, individual females returned in later seasons to mate with the same male as previously rather than at the same site. Previous work found that male interactions and dominance do not control matings and that females are very choosy about which territory they mate in. Here we show that this is because of the male occupying the territory rather than its position. We therefore conclude that direct female mate choice is the main behavioral process affecting variation in mating success among great snipe males, unlike in some lekking mammals where male competition and/or indirect mate choice appears more important.

  15. THE POSITIVE SOLUTION OF CLASSICAL GELFAND MODEL WITH COEFFICIENT THAT CHANGE SIGN

    Institute of Scientific and Technical Information of China (English)

    姚庆六

    2002-01-01

    The existence and iteration of positive solution for classical Gelfand models areconsidered, where the coefficient of nonlinear term is allowed to change sign in [ 0, 1 ]. Byusing the monotone iterative technique, an existence theorem of positive solution isobtained, corresponding iterative process and convergence rate are given. This iterativeprocess starts off with zero function, hence the process is simple, feasible and effective.

  16. Direct vs. Indirect Moral Enhancement.

    Science.gov (United States)

    Schaefer, G Owen

    2015-09-01

    Moral enhancement is an ostensibly laudable project. Who wouldn't want people to become more moral? Still, the project's approach is crucial. We can distinguish between two approaches for moral enhancement: direct and indirect. Direct moral enhancements aim at bringing about particular ideas, motives or behaviors. Indirect moral enhancements, by contrast, aim at making people more reliably produce the morally correct ideas, motives or behaviors without committing to the content of those ideas, motives and/or actions. I will argue, on Millian grounds, that the value of disagreement puts serious pressure on proposals for relatively widespread direct moral enhancement. A more acceptable path would be to focus instead on indirect moral enhancements while staying neutral, for the most part, on a wide range of substantive moral claims. I will outline what such indirect moral enhancement might look like, and why we should expect it to lead to general moral improvement.

  17. Ecology: Dynamics of Indirect Extinction.

    Science.gov (United States)

    Montoya, Jose M

    2015-12-01

    The experimental identification of the mechanism by which extinctions of predators trigger further predator extinctions emphasizes the role of indirect effects between species in disturbed ecosystems. It also has deep consequences for the hidden magnitude of the current biodiversity crisis.

  18. Positive Almost Periodic Solutions for a Time-Varying Fishing Model with Delay

    Directory of Open Access Journals (Sweden)

    Xia Li

    2011-01-01

    Full Text Available This paper is concerned with a time-varying fishing model with delay. By means of the continuation theorem of coincidence degree theory, we prove that it has at least one positive almost periodic solution.

  19. Bifurcation of Positive Equilibria in Nonlinear Structured Population Models with Varying Mortality Rates

    CERN Document Server

    Walker, Christoph

    2010-01-01

    A parameter-dependent model involving nonlinear diffusion for an age-structured population is studied. The parameter measures the intensity of the mortality. A bifurcation approach is used to establish existence of positive equilibrium solutions.

  20. Multiple positive periodic solutions for a generalized delayed population model with an exploited term

    Institute of Scientific and Technical Information of China (English)

    Zheng-qiu ZHANG; Zhi-cheng WANG

    2007-01-01

    In this paper, the existence of two positive periodic solutions for a generalized delayed population model with an exploited term is established by using the continuation theorem of the coincidence degree theory.

  1. Multiple Positive Solutions for Some Neutral Integral Equatious Modeling Infectious Disease

    Institute of Scientific and Technical Information of China (English)

    ZHAOHua-xiang; SUNXing-wang

    2003-01-01

    By using fixed point index theory of cone mapping and extension method,this paper discusses the existence of multiple positive solution of nonlinear neutral integral equatious modeling infectious dis-ease.

  2. Direct and indirect methods for the quantification of leg volume: Comparison between water displacement volumetry, the disk model method and the frustum sign model method, using the correlation coefficient and the limits of agreement

    NARCIS (Netherlands)

    D.M.K.S. Kaulesar Sukul (D. M K S); P.Th. den Hoed (Pieter); T. Johannes (Tanja); R. van Dolder (R.); E. Benda (Eric)

    1993-01-01

    textabstractVolume changes can be measured either directly by water-displacement volumetry or by various indirect methods in which calculation of the volume is based on circumference measurements. The aim of the present study was to determine the most appropriate indirect method for lower leg volume

  3. Direct and indirect methods for the quantification of leg volume: Comparison between water displacement volumetry, the disk model method and the frustum sign model method, using the correlation coefficient and the limits of agreement

    NARCIS (Netherlands)

    D.M.K.S. Kaulesar Sukul (D. M K S); P.Th. den Hoed (Pieter); T. Johannes (Tanja); R. van Dolder (R.); E. Benda (Eric)

    1993-01-01

    textabstractVolume changes can be measured either directly by water-displacement volumetry or by various indirect methods in which calculation of the volume is based on circumference measurements. The aim of the present study was to determine the most appropriate indirect method for lower leg volume

  4. Food assistance programmes are indirectly associated with anaemia status in children Mexico.

    Science.gov (United States)

    Shamah-Levy, Teresa; Méndez-Gómez-Humarán, Ignacio; Gaona-Pineda, Elsa B; Cuevas-Nasu, Lucia; Villalpando, Salvador

    2016-09-01

    Anaemia in children is a public health concern in Mexico; Federal food assistance programmes are being implemented to prevent it. We undertook this research to investigate the indirect association between food assistance programmes (FAP) and anaemia through dietary and socio-economic conditions of beneficiary children. A structural equation model (SEM) was constructed to assess associations among FAP, dietary and socio-economic conditions, as well as anaemia. A cross-sectional comparative study was conducted based on a sample of 1214 households with children malnutrition with amaranth (RMA) and a comparison group in San Luis Potosí, Mexico. The SEM and a decomposition effect analysis revealed the existence of a significant indirect association of FAP on the prevalence of anaemia via dietary and socio-economic conditions in children under 5 years old. The Prospera assistance programme showed a significant indirect positive association with the prevalence of anaemia (standard coefficient=0·027, P<0·031), and the RMA programme showed a significant indirect negative association with the prevalence of anaemia (standard coefficient=-0·029, P=0·047). There was a direct association between FAP and dietary and socio-economic conditions. FAP could indirectly modify the prevalence of anaemia in young children with a direct improvement on dietary and socio-economic conditions. The unexpected finding of the association between RMA, dietary and socio-economic conditions and the prevalence of anaemia reflects differences in the focus of the programmes.

  5. Existence and Convergence of the Positive Solutions of a Discrete Epidemic Model

    Directory of Open Access Journals (Sweden)

    Zhijian Wei

    2015-01-01

    Full Text Available We consider a class of system of nonlinear difference equations arising from mathematical models describing a discrete epidemic model. Sufficient conditions are established that guarantee the existence of positive solutions, the existence of a unique nonnegative equilibrium, and the convergence of the positive solutions to the nonnegative equilibrium of the system of difference equations. The obtained results are new and they complement previously known results.

  6. The propagation of inventory-based positional errors into statistical landslide susceptibility models

    Science.gov (United States)

    Steger, Stefan; Brenning, Alexander; Bell, Rainer; Glade, Thomas

    2016-12-01

    There is unanimous agreement that a precise spatial representation of past landslide occurrences is a prerequisite to produce high quality statistical landslide susceptibility models. Even though perfectly accurate landslide inventories rarely exist, investigations of how landslide inventory-based errors propagate into subsequent statistical landslide susceptibility models are scarce. The main objective of this research was to systematically examine whether and how inventory-based positional inaccuracies of different magnitudes influence modelled relationships, validation results, variable importance and the visual appearance of landslide susceptibility maps. The study was conducted for a landslide-prone site located in the districts of Amstetten and Waidhofen an der Ybbs, eastern Austria, where an earth-slide point inventory was available. The methodological approach comprised an artificial introduction of inventory-based positional errors into the present landslide data set and an in-depth evaluation of subsequent modelling results. Positional errors were introduced by artificially changing the original landslide position by a mean distance of 5, 10, 20, 50 and 120 m. The resulting differently precise response variables were separately used to train logistic regression models. Odds ratios of predictor variables provided insights into modelled relationships. Cross-validation and spatial cross-validation enabled an assessment of predictive performances and permutation-based variable importance. All analyses were additionally carried out with synthetically generated data sets to further verify the findings under rather controlled conditions. The results revealed that an increasing positional inventory-based error was generally related to increasing distortions of modelling and validation results. However, the findings also highlighted that interdependencies between inventory-based spatial inaccuracies and statistical landslide susceptibility models are complex. The

  7. Have Indirect Emissions from Biofuels Been Exaggerated?

    Science.gov (United States)

    Kicklighter, D. W.; Gurgel, A.; Melillo, J. M.; Reilly, J. M.; Cronin, T.; Felzer, B. S.; Paltsev, S.; Schlosser, C. A.; Sokolov, A. P.

    2009-12-01

    The production of biofuels may lead to enhanced greenhouse gas (GHG) emissions from land to the atmosphere either by directly converting land to biofuel crops, or indirectly, by causing the displacement of food production and other land uses which then require additional land conversions. The importance of indirect GHG emissions from biofuel-related displacement of food production and other land uses is not known and is highly controversial. Here, we examine the direct and indirect land-use emissions over the 21st century from an expanded global bioenergy program, using a linked economic and terrestrial biogeochemistry modeling system under two different land use policies. We account for the dynamics of potential carbon losses or gains from land-use change along with nitrous oxide emissions from increased N fertilizer application. We find that: 1) indirect emissions from land use are responsible for substantially more carbon loss (up to twice as much) than direct land use; 2) increased nitrous oxide emissions over the century are more important to the GHG balance than the carbon losses themselves; 3) the GHG effects of biofuels change in both sign and magnitude over time so that the GHG cost/benefit of biofuels depends on the time horizon considered; and 4) the economics of biofuels become favorable sooner with the protection of forests. While biofuels can be an effective low carbon energy source from a GHG balance perspective, the associated land conversions may lead to an unacceptable loss of other ecosystem services.

  8. Model of Head-Positioning Error Due to Rotational Vibration of Hard Disk Drives

    Science.gov (United States)

    Matsuda, Yasuhiro; Yamaguchi, Takashi; Saegusa, Shozo; Shimizu, Toshihiko; Hamaguchi, Tetsuya

    An analytical model of head-positioning error due to rotational vibration of a hard disk drive is proposed. The model takes into account the rotational vibration of the base plate caused by the reaction force of the head-positioning actuator, the relationship between the rotational vibration and head-track offset, and the sensitivity function of track-following feedback control. Error calculated by the model agrees well with measured error. It is thus concluded that this model can predict the data transfer performance of a disk drive in read mode.

  9. Waif goodbye! Average-size female models promote positive body image and appeal to consumers.

    Science.gov (United States)

    Diedrichs, Phillippa C; Lee, Christina

    2011-10-01

    Despite consensus that exposure to media images of thin fashion models is associated with poor body image and disordered eating behaviours, few attempts have been made to enact change in the media. This study sought to investigate an effective alternative to current media imagery, by exploring the advertising effectiveness of average-size female fashion models, and their impact on the body image of both women and men. A sample of 171 women and 120 men were assigned to one of three advertisement conditions: no models, thin models and average-size models. Women and men rated average-size models as equally effective in advertisements as thin and no models. For women with average and high levels of internalisation of cultural beauty ideals, exposure to average-size female models was associated with a significantly more positive body image state in comparison to exposure to thin models and no models. For men reporting high levels of internalisation, exposure to average-size models was also associated with a more positive body image state in comparison to viewing thin models. These findings suggest that average-size female models can promote positive body image and appeal to consumers.

  10. GPS/GLONASS Combined Precise Point Positioning with Receiver Clock Modeling.

    Science.gov (United States)

    Wang, Fuhong; Chen, Xinghan; Guo, Fei

    2015-06-30

    Research has demonstrated that receiver clock modeling can reduce the correlation coefficients among the parameters of receiver clock bias, station height and zenith tropospheric delay. This paper introduces the receiver clock modeling to GPS/GLONASS combined precise point positioning (PPP), aiming to better separate the receiver clock bias and station coordinates and therefore improve positioning accuracy. Firstly, the basic mathematic models including the GPS/GLONASS observation equations, stochastic model, and receiver clock model are briefly introduced. Then datasets from several IGS stations equipped with high-stability atomic clocks are used for kinematic PPP tests. To investigate the performance of PPP, including the positioning accuracy and convergence time, a week of (1-7 January 2014) GPS/GLONASS data retrieved from these IGS stations are processed with different schemes. The results indicate that the positioning accuracy as well as convergence time can benefit from the receiver clock modeling. This is particularly pronounced for the vertical component. Statistic RMSs show that the average improvement of three-dimensional positioning accuracy reaches up to 30%-40%. Sometimes, it even reaches over 60% for specific stations. Compared to the GPS-only PPP, solutions of the GPS/GLONASS combined PPP are much better no matter if the receiver clock offsets are modeled or not, indicating that the positioning accuracy and reliability are significantly improved with the additional GLONASS satellites in the case of insufficient number of GPS satellites or poor geometry conditions. In addition to the receiver clock modeling, the impacts of different inter-system timing bias (ISB) models are investigated. For the case of a sufficient number of satellites with fairly good geometry, the PPP performances are not seriously affected by the ISB model due to the low correlation between the ISB and the other parameters. However, the refinement of ISB model weakens the

  11. Modeling and Control for Dynamic Positioned Marine Vessels in Drifting Managed Sea Ice

    Directory of Open Access Journals (Sweden)

    Øyvind Kåre Kjerstad

    2014-10-01

    Full Text Available This paper presents a development framework for dynamic positioning control systems for marine vessels in managed ice. Due to the complexity of the vessel-ice and ice-ice interactions a configurable high fidelity numerical model simulating the vessel, the ice floes, the water, and the boundaries is applied. The numerical model is validated using experimental data and coupled with a control application incorporating sensor models, control systems, actuator models, and other external dynamics to form a closed loop development platform. The ice drift reversal is simulated by moving the positioning reference frame in an elliptic trajectory, rather than moving each individual ice floe. A control plant model is argued, and a control system for managed ice is proposed based on conventional open water design methods. A case study shows that dynamic positioning in managed ice is feasible for some moderate ice conditions.

  12. Environmental implications of the use of agro-industrial residues for biorefineries: application of a deterministic model for indirect land-use changes

    DEFF Research Database (Denmark)

    Tonini, Davide; Hamelin, Lorie; Astrup, Thomas Fruergaard

    2016-01-01

    .1 t CO2-eq.ha-1demanded y-1 corresponding to 1.2-1.5 t CO2 t-1 dry biomass used for energy. Only bioenergy from straw and wild grass was shown to perform better than the alternative use, as no competition with the feed sector was involved. Biogas for heat-and-power production was the best performing......Biorefining agro-industrial biomass residues for bioenergy production represents an opportunity for both sustainable energy supply and greenhouse gas (GHG) emissions mitigation. Yet, is bioenergy the most sustainable use for these residues? To assess the importance of the alternative use...... of these residues, a consequential life-cycle assessment (LCA) of 32 energy-focused biorefinery scenarios was performed based on eight selected agro-industrial residues and four conversion pathways (two involving bioethanol and two biogas). To specifically address indirect land-use changes (iLUC) induced...

  13. Modeling the Behavior of an Underwater Acoustic Relative Positioning System Based on Complementary Set of Sequences

    Science.gov (United States)

    Aparicio, Joaquín; Jiménez, Ana; Álvarez, Fernando J.; Ureña, Jesús; De Marziani, Carlos; Diego, Cristina

    2011-01-01

    The great variability usually found in underwater media makes modeling a challenging task, but helpful for better understanding or predicting the performance of future deployed systems. In this work, an underwater acoustic propagation model is presented. This model obtains the multipath structure by means of the ray tracing technique. Using this model, the behavior of a relative positioning system is presented. One of the main advantages of relative positioning systems is that only the distances between all the buoys are needed to obtain their positions. In order to obtain the distances, the propagation times of acoustic signals coded by Complementary Set of Sequences (CSS) are used. In this case, the arrival instants are obtained by means of correlation processes. The distances are then used to obtain the position of the buoys by means of the Multidimensional Scaling Technique (MDS). As an early example of an application using this relative positioning system, a tracking of the position of the buoys at different times is performed. With this tracking, the surface current of a particular region could be studied. The performance of the system is evaluated in terms of the distance from the real position to the estimated one. PMID:22247661

  14. Scalar Dark Matter: Direct vs. Indirect Detection

    CERN Document Server

    Duerr, Michael; Smirnov, Juri

    2015-01-01

    We revisit the simplest model for dark matter. In this context the dark matter candidate is a real scalar field which interacts with the Standard Model particles through the Higgs portal. We discuss the relic density constraints as well as the predictions for direct and indirect detection. The final state radiation processes are investigated in order to understand the visibility of the gamma lines from dark matter annihilation. We find two regions where one could observe the gamma lines at gamma-ray telescopes. We point out that the region where the dark matter mass is between 100 and 300 GeV can be tested in the near future at direct and indirect detection experiments.

  15. Real medical benefit assessed by indirect comparison.

    Science.gov (United States)

    Falissard, Bruno; Zylberman, Myriam; Cucherat, Michel; Izard, Valérie; Meyer, François

    2009-01-01

    Frequently, in data packages submitted for Marketing Approval to the CHMP, there is a lack of relevant head-to-head comparisons of medicinal products that could enable national authorities responsible for the approval of reimbursement to assess the Added Therapeutic Value (ASMR) of new clinical entities or line extensions of existing therapies.Indirect or mixed treatment comparisons (MTC) are methods stemming from the field of meta-analysis that have been designed to tackle this problem. Adjusted indirect comparisons, meta-regressions, mixed models, Bayesian network analyses pool results of randomised controlled trials (RCTs), enabling a quantitative synthesis.The REAL procedure, recently developed by the HAS (French National Authority for Health), is a mixture of an MTC and effect model based on expert opinions. It is intended to translate the efficacy observed in the trials into effectiveness expected in day-to-day clinical practice in France.

  16. Indirect emissions from biofuels: how important?

    Science.gov (United States)

    Melillo, Jerry M; Reilly, John M; Kicklighter, David W; Gurgel, Angelo C; Cronin, Timothy W; Paltsev, Sergey; Felzer, Benjamin S; Wang, Xiaodong; Sokolov, Andrei P; Schlosser, C Adam

    2009-12-04

    A global biofuels program will lead to intense pressures on land supply and can increase greenhouse gas emissions from land-use changes. Using linked economic and terrestrial biogeochemistry models, we examined direct and indirect effects of possible land-use changes from an expanded global cellulosic bioenergy program on greenhouse gas emissions over the 21st century. Our model predicts that indirect land use will be responsible for substantially more carbon loss (up to twice as much) than direct land use; however, because of predicted increases in fertilizer use, nitrous oxide emissions will be more important than carbon losses themselves in terms of warming potential. A global greenhouse gas emissions policy that protects forests and encourages best practices for nitrogen fertilizer use can dramatically reduce emissions associated with biofuels production.

  17. Indirect comparisons of therapeutic interventions

    Directory of Open Access Journals (Sweden)

    Boulkhemair, Dalila

    2009-07-01

    Full Text Available Health political background: The comparison of the effectiveness of health technologies is not only laid down in German law (Social Code Book V, § 139 and § 35b but also constitutes a central element of clinical guidelines and decision making in health care. Tools supporting decision making (e. g. Health Technology Assessments (HTA are therefore in need of a valid methodological repertoire for these comparisons. Scientific background: Randomised controlled head-to-head trials which directly compare the effects of different therapies are considered the gold standard methodological approach for the comparison of the efficacy of interventions. Because this type of trial is rarely found, comparisons of efficacy often need to rely on indirect comparisons whose validity is being controversially debated. Research questions: Research questions for the current assessment are: Which (statistical methods for indirect comparisons of therapeutic interventions do exist, how often are they applied and how valid are their results in comparison to the results of head-to-head trials? Methods: In a systematic literature research all medical databases of the German Institute of Medical Documentation and Information (DIMDI are searched for methodological papers as well as applications of indirect comparisons in systematic reviews. Results of the literature analysis are summarized qualitatively for the characterisation of methods and quantitatively for the frequency of their application. The validity of the results from indirect comparisons is checked by comparing them to the results from the gold standard – a direct comparison. Data sets from systematic reviews which use both direct and indirect comparisons are tested for consistency by of the z-statistic. Results: 29 methodological papers and 106 applications of indirect methods in systematic reviews are being analysed. Four methods for indirect comparisons can be identified: 1. Unadjusted indirect comparisons

  18. Indirect effects of prey swamping: differential seed predation during a bamboo masting event.

    Science.gov (United States)

    Kitzberger, Thomas; Chaneton, Enrique J; Caccia, Fernando

    2007-10-01

    Resource pulses often involve extraordinary increases in prey availability that "swamp" consumers and reverberate through indirect interactions affecting other community members. We developed a model that predicts predator-mediated indirect effects induced by an epidemic prey on co-occurring prey types differing in relative profitability/preference and validated our model by examining current-season and delayed effects of a bamboo mass seeding event on seed survival of canopy tree species in mixed Patagonian forests. The model shows that predator foraging behavior, prey profitability, and the scale of prey swamping influence the character and strength of short-term indirect effects on various alternative prey. When in large prey-swamped patches, nonselective predators decrease predation on all prey types. Selective predators, instead, only benefit prey of similar quality to the swamping species, while very low or high preference prey remain unaffected. Negative indirect effects (apparent competition) may override such positive effects (apparent mutualism), especially for highly preferred prey, when prey-swamped patches are small enough to allow predator aggregation and/or predators show a reproductive numerical response to elevated food supply. Seed predation patterns during bamboo (Chusquea culeou) masting were consistent with predicted short-term indirect effects mediated by a selective predator foraging in large prey-swamped patches. Bamboo seeds and similarly-sized Austrocedrus chilensis (ciprés) and Nothofagus obliqua (roble) seeds suffered lower predation in bamboo flowered than nonflowered patches. Predation rates on the small-seeded Nothofagus dombeyi (coihue) and the large-seeded Nothofagus alpina (rauli) were independent of bamboo flowering. Indirect positive effects were transient; three months after bamboo seeding, granivores preyed heavily upon all seed types, irrespective of patch flowering condition. Moreover, one year after bamboo seeding

  19. Behavioral Models of Depression: A Critique of the Emphasis on Positive Reinforcement

    Science.gov (United States)

    Abreu, Paulo Roberto; Santos, Carlos E.

    2008-01-01

    This paper provides a review of behavioral models of depression highlighting the problems associated with its historical emphasis on lowered frequencies of positive reinforcement. We analyzed the models of Ferster and Lewinsohn in their theoretical approach, methodology and application. We conducted a review of the suppressive characteristics…

  20. Position and orientation estimation of fixed dipole emitters using an effective Hermite point spread function model

    NARCIS (Netherlands)

    Stallinga, S.; Rieger, B.

    2012-01-01

    We introduce a method for determining the position and orientation of fixed dipole emitters based on a combination of polarimetry and spot shape detection. A key element is an effective Point Spread Function model based on Hermite functions. The model offers a good description of the shape variation

  1. Translocation of positively and negatively charged polystyrene nanoparticles in an in vitro placental model

    NARCIS (Netherlands)

    Kloet, S.K.; Walczak, A.P.; Louisse, J.; Berg, H.H.J. van den; Bouwmeester, H.; Tromp, P.; Fokkink, R.G.; Rietjens, I.M.C.M.

    2015-01-01

    To obtain insight in translocation of nanoparticles across the placental barrier, translocation was studied for one positively and two negatively charged polystyrene nanoparticles (PS-NPs) of similar size in an in vitro model. The model consisted of BeWo b30 cells, derived from a human choriocarcino

  2. Characterization of positive solution to stochastic competitor-competitor-cooperative model

    Directory of Open Access Journals (Sweden)

    Partha Sarathi Mandal

    2013-04-01

    Full Text Available In this article we study a randomized three-dimensional Lotka-Volterra model with competitor-competitor-mutualist interaction. We show the existence, uniqueness, moment boundedness, stochastic boundedness and global asymptotic stability of positive global solutions for this stochastic model. Analytical results are validated by numerical examples.

  3. Modeling difference of reference surfaces of the Earth's body to solve the problem of vertical positioning

    Directory of Open Access Journals (Sweden)

    Tucikešić Sanja S.

    2016-01-01

    Full Text Available The aim of this paper is modeling difference of reference surfaces of the Earth's body to solve the problem of vertical positioning. With development of GNSS technology determining geoid undulation obtained scientific and practical significance especially in the vertical position with the aim of replacing the traditional geometrical leveling. The paper presents the modeling corrective surface based on GNSS measurements through a practical example of Local Spatial Reference Network (PLRM Mrkonjic Grad where the measurements were made with GNSS observations. The modeling was performed onedimensional similarity transformation and the average differences between orthometric height of a GNSS measurements and transformed height were determined.

  4. Position-specific isotope modeling of organic micropollutants transformation through different reaction pathways

    DEFF Research Database (Denmark)

    Jin, Biao; Rolle, Massimo

    2016-01-01

    The degradation of organic micropollutants occurs via different reaction pathways. Compound specific isotope analysis is a valuable tool to identify such degradation pathways in different environmental systems. We propose a mechanism-based modeling approach that provides a quantitative framework...... to simultaneously evaluate concentration as well as bulk and position-specific multi-element isotope evolution during the transformation of organic micropollutants. The model explicitly simulates position-specific isotopologues for those atoms that experience isotope effects and, thereby, provides a mechanistic...... description of isotope fractionation occurring at different molecular positions. To demonstrate specific features of the modeling approach, we simulated the degradation of three selected organic micropollutants: dichlorobenzamide (BAM), isoproturon (IPU) and diclofenac (DCF). The model accurately reproduces...

  5. Existence and Uniqueness of Positive and Bounded Solutions of a Discrete Population Model with Fractional Dynamics

    Directory of Open Access Journals (Sweden)

    J. E. Macías-Díaz

    2017-01-01

    Full Text Available We depart from the well-known one-dimensional Fisher’s equation from population dynamics and consider an extension of this model using Riesz fractional derivatives in space. Positive and bounded initial-boundary data are imposed on a closed and bounded domain, and a fully discrete form of this fractional initial-boundary-value problem is provided next using fractional centered differences. The fully discrete population model is implicit and linear, so a convenient vector representation is readily derived. Under suitable conditions, the matrix representing the implicit problem is an inverse-positive matrix. Using this fact, we establish that the discrete population model is capable of preserving the positivity and the boundedness of the discrete initial-boundary conditions. Moreover, the computational solubility of the discrete model is tackled in the closing remarks.

  6. Three-dimensional Modelling Technology for City Indoor Positioning and Navigation Applications

    Science.gov (United States)

    Zhang, Xin; Chen, Yongxin; Wang, Weisheng

    2016-11-01

    For city indoor positioning and navigation applications, there are two technical problems should be solved, which are the modelling efficiency and the validity and accuracy of the spatial models. In this paper, the quick modelling technology is introduced which uses the multi-angle remote sensing based on the unmanned aerial vehicle measurement. To enhance the validity and accuracy of the spatial models, we proposed an algorithm to remove the line style and planar style foreground occlusions before reconstructing backgrounds. The three-dimensional models can only provide the spatial framework for the city indoor positioning. Furthermore, the simple indoor three-dimensional modelling technology which is based on the building design drawings. In the end, the application in the public safety emergency rescue is introduced.

  7. Generation model of positional values as cell operation during the development of multicellular organisms.

    Science.gov (United States)

    Ogawa, Ken-ichiro; Miyake, Yoshihiro

    2011-03-01

    Many conventional models have used the positional information hypothesis to explain each elementary process of morphogenesis during the development of multicellular organisms. Their models assume that the steady concentration patterns of morphogens formed in an extracellular environment have an important property of positional information, so-called "robustness". However, recent experiments reported that a steady morphogen pattern, the concentration gradient of the Bicoid protein, during early Drosophila embryonic development is not robust for embryo-to-embryo variability. These reports encourage a reconsideration of a long-standing problem in systematic cell differentiation: what is the entity of positional information for cells? And, what is the origin of the robust boundary of gene expression? To address these problems at a cellular level, in this article we pay attention to the re-generative phenomena that show another important property of positional information, "size invariance". In view of regenerative phenomena, we propose a new mathematical model to describe the generation mechanism of a spatial pattern of positional values. In this model, the positional values are defined as the values into which differentiable cells transform a spatial pattern providing positional information. The model is mathematically described as an associative algebra composed of various terms, each of which is the multiplication of some fundamental operators under the assumption that the operators are derived from the remarkable properties of cell differentiation on an amputation surface in regenerative phenomena. We apply this model to the concentration pattern of the Bicoid protein during the anterior-posterior axis formation in Drosophila, and consider the conditions needed to establish the robust boundary of the expression of the hunchback gene.

  8. Experimental calibration of the mathematical model of Air Torque Position dampers with non-cascading blades

    Directory of Open Access Journals (Sweden)

    Bikić Siniša M.

    2016-01-01

    Full Text Available This paper is focused on the mathematical model of the Air Torque Position dampers. The mathematical model establishes a link between the velocity of air in front of the damper, position of the damper blade and the moment acting on the blade caused by the air flow. This research aims to experimentally verify the mathematical model for the damper type with non-cascading blades. Four different types of dampers with non-cascading blades were considered: single blade dampers, dampers with two cross-blades, dampers with two parallel blades and dampers with two blades of which one is a fixed blade in the horizontal position. The case of a damper with a straight pipeline positioned in front of and behind the damper was taken in consideration. Calibration and verification of the mathematical model was conducted experimentally. The experiment was conducted on the laboratory facility for testing dampers used for regulation of the air flow rate in heating, ventilation and air conditioning systems. The design and setup of the laboratory facility, as well as construction, adjustment and calibration of the laboratory damper are presented in this paper. The mathematical model was calibrated by using one set of data, while the verification of the mathematical model was conducted by using the second set of data. The mathematical model was successfully validated and it can be used for accurate measurement of the air velocity on dampers with non-cascading blades under different operating conditions. [Projekat Ministarstva nauke Republike Srbije, br. TR31058

  9. Subject-specific musculoskeletal model of the lower limb in a lying and standing position.

    Science.gov (United States)

    Hausselle, J; Assi, A; El Helou, A; Jolivet, E; Pillet, H; Dion, E; Bonneau, D; Skalli, W

    2014-04-01

    Accurate estimation of joint loads implies using subject-specific musculoskeletal models. Moreover, as the lines of action of the muscles are dictated by the soft tissues, which are in turn influenced by gravitational forces, we developed a method to build subject-specific models of the lower limb in a functional standing position. Bones and skin envelope were obtained in a standing position, whereas muscles and a set of bony landmarks were obtained from conventional magnetic resonance images in a lying position. These muscles were merged with the subject-specific skeletal model using a nonlinear transformation, taking into account soft tissue movements and gravitational effects. Seven asymptomatic lower limbs were modelled using this method, and results showed realistic deformations. Comparing the subject-specific skeletal model to a scaled reference model rendered differences in terms of muscle length up to 4% and in terms of moment arm for adductor muscles up to 30%. These preliminary findings enlightened the importance of subject-specific modelling in a functional position.

  10. Simplified modeling and generalized predictive position control of an ultrasonic motor.

    Science.gov (United States)

    Bigdeli, Nooshin; Haeri, Mohammad

    2005-04-01

    Ultrasonic motors (USM's) possess heavy nonlinear and load dependent characteristics such as dead-zone and saturation reverse effects, which vary with driving conditions. In this paper, behavior of an ultrasonic motor is modeled using Hammerstein model structure and experimental measurements. Also, model predictive controllers are designed to obtain precise USM position control. Simulation results indicate improved performance of the motor for both set point tracking and disturbance rejection.

  11. Ant Colony Optimization Algorithm for Continuous Domains Based on Position Distribution Model of Ant Colony Foraging

    OpenAIRE

    Liqiang Liu; Yuntao Dai; Jinyu Gao

    2014-01-01

    Ant colony optimization algorithm for continuous domains is a major research direction for ant colony optimization algorithm. In this paper, we propose a distribution model of ant colony foraging, through analysis of the relationship between the position distribution and food source in the process of ant colony foraging. We design a continuous domain optimization algorithm based on the model and give the form of solution for the algorithm, the distribution model of pheromone, the update rules...

  12. Experimental Exploration of RSSI Model for the Vehicle Intelligent Position System

    Directory of Open Access Journals (Sweden)

    Zhichao Cao

    2015-01-01

    Full Text Available Vehicle intelligent position systems based on Received Signal Strength Indicator (RSSI in Wireless Sensor Networks (WSNs are efficiently utilized. The vehicle’s position accuracy is of great importance for transportation behaviors, such as dynamic vehicle routing problems and multiple pedestrian routing choice behaviors and so on. Therefore, a precise position and available optimization is necessary for total parameters of conventional RSSI model. In this papar, we investigate the experimental performance of translating the power measurements to corresponding distance between each pair of nodes. The priori knowledge about the environment interference could impact the accuracy of vehicles’s position and the reliability of paremeters greatly. Based on the real-world outdoor experiments, we compares different regression analysis of the RSSI model, in order to establish a calibration scheme on RSSI model. We showed that the average error of RSSI model is able to decrease throughout the rules of environmental factor n and shadowing factor ? respectively. Moreover, the calculation complexity is reduced. Since variation tendency of environmental factor n, shadowing factor ? with distance and signal strength could be simulated respectively, RSSI model fulfills the precision of the vehicle intelligent position system.

  13. Position-specific isotope modeling of organic micropollutants transformation through different reaction pathways.

    Science.gov (United States)

    Jin, Biao; Rolle, Massimo

    2016-03-01

    The degradation of organic micropollutants occurs via different reaction pathways. Compound specific isotope analysis is a valuable tool to identify such degradation pathways in different environmental systems. We propose a mechanism-based modeling approach that provides a quantitative framework to simultaneously evaluate concentration as well as bulk and position-specific multi-element isotope evolution during the transformation of organic micropollutants. The model explicitly simulates position-specific isotopologues for those atoms that experience isotope effects and, thereby, provides a mechanistic description of isotope fractionation occurring at different molecular positions. To demonstrate specific features of the modeling approach, we simulated the degradation of three selected organic micropollutants: dichlorobenzamide (BAM), isoproturon (IPU) and diclofenac (DCF). The model accurately reproduces the multi-element isotope data observed in previous experimental studies. Furthermore, it precisely captures the dual element isotope trends characteristic of different reaction pathways as well as their range of variation consistent with observed bulk isotope fractionation. It was also possible to directly validate the model capability to predict the evolution of position-specific isotope ratios with available experimental data. Therefore, the approach is useful both for a mechanism-based evaluation of experimental results and as a tool to explore transformation pathways in scenarios for which position-specific isotope data are not yet available.

  14. Beyond the French Flag Model: Exploiting Spatial and Gene Regulatory Interactions for Positional Information

    Science.gov (United States)

    Hillenbrand, Patrick; Gerland, Ulrich; Tkačik, Gašper

    2016-01-01

    A crucial step in the early development of multicellular organisms involves the establishment of spatial patterns of gene expression which later direct proliferating cells to take on different cell fates. These patterns enable the cells to infer their global position within a tissue or an organism by reading out local gene expression levels. The patterning system is thus said to encode positional information, a concept that was formalized recently in the framework of information theory. Here we introduce a toy model of patterning in one spatial dimension, which can be seen as an extension of Wolpert’s paradigmatic “French Flag” model, to patterning by several interacting, spatially coupled genes subject to intrinsic and extrinsic noise. Our model, a variant of an Ising spin system, allows us to systematically explore expression patterns that optimally encode positional information. We find that optimal patterning systems use positional cues, as in the French Flag model, together with gene-gene interactions to generate combinatorial codes for position which we call “Counter” patterns. Counter patterns can also be stabilized against noise and variations in system size or morphogen dosage by longer-range spatial interactions of the type invoked in the Turing model. The simple setup proposed here qualitatively captures many of the experimentally observed properties of biological patterning systems and allows them to be studied in a single, theoretically consistent framework. PMID:27676252

  15. Adaptive Indoor Positioning Model Based on WLAN-Fingerprinting for Dynamic and Multi-Floor Environments

    Directory of Open Access Journals (Sweden)

    Iyad Husni Alshami

    2017-08-01

    Full Text Available The Global Positioning System demonstrates the significance of Location Based Services but it cannot be used indoors due to the lack of line of sight between satellites and receivers. Indoor Positioning Systems are needed to provide indoor Location Based Services. Wireless LAN fingerprints are one of the best choices for Indoor Positioning Systems because of their low cost, and high accuracy, however they have many drawbacks: creating radio maps is time consuming, the radio maps will become outdated with any environmental change, different mobile devices read the received signal strength (RSS differently, and peoples’ presence in LOS between access points and mobile device affects the RSS. This research proposes a new Adaptive Indoor Positioning System model (called DIPS based on: a dynamic radio map generator, RSS certainty technique and peoples’ presence effect integration for dynamic and multi-floor environments. Dynamic in our context refers to the effects of people and device heterogeneity. DIPS can achieve 98% and 92% positioning accuracy for floor and room positioning, and it achieves 1.2 m for point positioning error. RSS certainty enhanced the positioning accuracy for floor and room for different mobile devices by 11% and 9%. Then by considering the peoples’ presence effect, the error is reduced by 0.2 m. In comparison with other works, DIPS achieves better positioning without extra devices.

  16. Electromagnetic modeling of beam position and phase monitors for SNS linac

    Science.gov (United States)

    Kurennoy, Sergey S.

    2000-11-01

    Electromagnetic modeling of the beam position monitors (BPMs) for the Spallation Neutron Source (SNS) linac has been performed with MAFIA. The signal amplitudes and phases on the BPM electrodes are computed as functions of the beam transverse position using time-domain 3-D simulations with an ultra-relativistic beam. An analytical model is then applied to extrapolate the results to lower beam velocities. It is shown that while the signal phases on the individual electrodes for an off-axis beam can differ from those for a centered beam by a few degrees, the phase of the summed signal from all electrodes is insensitive to the beam transverse position inside the device. Based on the analysis results, an optimal BPM design with 4 one-end-shorted 60-degree electrodes has been chosen. It provides a very good linearity and sufficient signal power for both position and phase measurements, while satisfying the linac geometrical constrains and mechanical requirements.

  17. Examining Teacher Outcomes of the School-Wide Positive Behavior Support Model in Norway

    Directory of Open Access Journals (Sweden)

    Mari-Anne Sørlie

    2016-05-01

    Full Text Available Research on teacher outcomes of the School-Wide Positive Behavior Support (SWPBS model has been scarce. The present study adds to the knowledge base by examining the effects of the Norwegian version of SWPBS (N-PALS on school staffs’ behavior management practices and on their individual and collective efficacy. Questionnaire data were collected from staff and students (Grades 4-7 at four measurement points across four successive school years in 28 intervention schools and 20 comparison schools. Using longitudinal multilevel analyses, indications of positive 3-year main effects of the N-PALS model were observed for staff-reported collective efficacy, self-efficacy, and positive behavior support practices. The intervention effects as measured by Cohen’s d ranged from .14 to .91. The effects on student perceptions of teachers’ behavior management strategies were, however, not consistent with the positive staff ratings. Results are discussed in relation to prior research, future research, and study limitations.

  18. Model Predictive Controller Design for the Dynamic Positioning System of a Semi-submersible Platform

    Institute of Scientific and Technical Information of China (English)

    Hongli Chen; Lei Wan; Fang Wang; Guocheng Zhang

    2012-01-01

    This paper researches how to apply the advanced control technology of model predictive control (MPC) to the design of the dynamic positioning system (DPS) of a semi-submersible platform.First,a linear low-frequency motion model with three degrees of freedom was established in the context of a semi-submersible platform.Second,a model predictive controller was designed based on a model which took the constraints of the system into account.Third,simulation was carried out to demonstrate the feasibility of the controller.The results show that the model predictive controller has good performance and good at dealing with the constraints of the system.

  19. Application of Artificial Neural Networks in the Heart Electrical Axis Position Conclusion Modeling

    Science.gov (United States)

    Bakanovskaya, L. N.

    2016-08-01

    The article touches upon building of a heart electrical axis position conclusion model using an artificial neural network. The input signals of the neural network are the values of deflections Q, R and S; and the output signal is the value of the heart electrical axis position. Training of the network is carried out by the error propagation method. The test results allow concluding that the created neural network makes a conclusion with a high degree of accuracy.

  20. Positive Almost Periodic Solution on a Nonlinear Logistic Biological Model with Grazing Rates

    Institute of Scientific and Technical Information of China (English)

    NI Hua; TIAN Li-xin

    2013-01-01

    In this paper,we study the following nonlinear biological model dx(t)/dt =x(t)[a(t)-b(t)xα(t)] + f(t,xt),by using fixed pointed theorem,the sufficient conditions of the existence of unique positive almost periodic solution for the above system are obtained,by using the theories of stability,the sufficient conditions which guarantee the stability of the positive almost periodic solution are derived.

  1. Modeling bidding competitiveness and position performance in multi-attribute construction auctions

    OpenAIRE

    Ballesteros-Pérez, Pablo; del Campo-Hitschfeld, Maria Luisa; Mora-Melià, Daniel; Domínguez, David

    2015-01-01

    Currently, multi-attribute auctions are becoming widespread awarding mechanisms for contracts in construction, and in these auctions, criteria other than price are taken into account for ranking bidder proposals. Therefore, being the lowest-price bidder is no longer a guarantee of being awarded, thus increasing the importance of measuring any bidder’s performance when not only the first position (lowest price) matters.\\ud \\ud Modeling position performance allows a tender manager to calculate ...

  2. PERCEIVED AUTONOMY SUPPORT AND BEHAVIORAL ENGAGEMENT IN PHYSICAL EDUCATION: A CONDITIONAL PROCESS MODEL OF POSITIVE EMOTION AND AUTONOMOUS MOTIVATION.

    Science.gov (United States)

    Yoo, Jin

    2015-06-01

    A variety of theoretical perspectives describe the crucial behavioral roles of motivation and emotion, but how these interact with perceptions of social contexts and behaviors is less well understood. This study examined whether autonomous motivation mediated the relationship between perceived autonomy support and behavioral engagement in physical education and whether this mediating process was moderated by positive emotion. A sample of 592 Korean middle-school students (304 boys, 288 girls; M age = 14.0 yr., SD = 0.8) completed questionnaires. Autonomous motivation partially mediated the positive association between perceived autonomy support and behavioral engagement. Positive emotion moderated the relationship between autonomous motivation and behavioral engagement. This indirect link was stronger as positive emotion increased. These findings suggest the importance of integrating emotion into motivational processes to understand how and when perceived autonomy support is associated with behavioral engagement in physical education.

  3. Incremental validity of positive orientation: predictive efficiency beyond the five-factor model

    Directory of Open Access Journals (Sweden)

    Łukasz Roland Miciuk

    2016-05-01

    Full Text Available Background The relation of positive orientation (a basic predisposition to think positively of oneself, one’s life and one’s future and personality traits is still disputable. The purpose of the described research was to verify the hypothesis that positive orientation has predictive efficiency beyond the five-factor model. Participants and procedure One hundred and thirty participants (at the mean age M = 24.84 completed the following questionnaires: the Self-Esteem Scale (SES, the Satisfaction with Life Scale (SWLS, the Life Orientation Test-Revised (LOT-R, the Positivity Scale (P-SCALE, the NEO Five Factor Inventory (NEO-FFI, the Self-Concept Clarity Scale (SCC, the Generalized Self-Efficacy Scale (GSES and the Life Engagement Test (LET. Results The introduction of positive orientation as an additional predictor in the second step of regression analyses led to better prediction of the following variables: purpose in life, self-concept clarity and generalized self-efficacy. This effect was the strongest for predicting purpose in life (i.e. 14% increment of the explained variance. Conclusions The results confirmed our hypothesis that positive orientation can be characterized by incremental validity – its inclusion in the regression model (in addition to the five main factors of personality increases the amount of explained variance. These findings may provide further evidence for the legitimacy of measuring positive orientation and personality traits separately.

  4. Extending positive C-LASS results across multiple instructors and multiple classes of Modeling Instruction

    CERN Document Server

    Brewe, Eric; de la Garza, Jorge; Kramer, Laird H

    2013-01-01

    We report on a multi year study of student attitudes measured with the Colorado Learning Attitudes about Science Survey (C-LASS) in calculus-based introductory physics taught with the Modeling Instruction curriculum. We find that five of six instructors and eight of nine sections using Modeling Instruction showed improved attitudes from pre to post course. Cohen's d effect sizes range from 0.08 to 0.95 for individual instructors. The average effect was d = 0.45, with a 95% confidence interval of (0.26 to 0.64). These results build on previously published results showing positive shifts in attitudes from Modeling Instruction classes. We interpret these data in light of other published positive attitudinal shifts and explore mechanistic explanations for similarities and differences with other published positive shifts.

  5. Observational and model evidence for positive low-level cloud feedback.

    Science.gov (United States)

    Clement, Amy C; Burgman, Robert; Norris, Joel R

    2009-07-24

    Feedbacks involving low-level clouds remain a primary cause of uncertainty in global climate model projections. This issue was addressed by examining changes in low-level clouds over the Northeast Pacific in observations and climate models. Decadal fluctuations were identified in multiple, independent cloud data sets, and changes in cloud cover appeared to be linked to changes in both local temperature structure and large-scale circulation. This observational analysis further indicated that clouds act as a positive feedback in this region on decadal time scales. The observed relationships between cloud cover and regional meteorological conditions provide a more complete way of testing the realism of the cloud simulation in current-generation climate models. The only model that passed this test simulated a reduction in cloud cover over much of the Pacific when greenhouse gases were increased, providing modeling evidence for a positive low-level cloud feedback.

  6. Simulation of Model Force-Loading with Changing Its Position in the Wind Tunnel Test Section

    Directory of Open Access Journals (Sweden)

    V. T. Bui

    2015-01-01

    Full Text Available When planning and implementing an aerodynamic experiment, model sizes and its position in the test section of the wind tunnel (WT play very important role. The paper focuses on the value variations of the aerodynamic characteristics of a model through changing its position in the WT test section and on the attenuation of the velocity field disturbance in front of the model. Flow around aerodynamic model profile in the open test section of the low-speed WT T-500 is simulated at BMSTU Department SM3. The problem is solved in a two-dimensional case using the ANSYS Fluent package. The mathematical model of flow is based on the Reynolds equations closed by the SST turbulence model. The paper also presents the results of the experiment. Experiments conducted in WT T-500 well correlate with the calculated data and show the optimal position in the middle of the test section when conducting the weighing and drainage experiments. Disturbance of tunnel dynamic pressure (velocity head and flow upwash around the model profile and circular cylinder in the WT test section is analyzed. It was found that flow upstream from the front stagnation point on the body weakly depends on the Reynolds number and obtained results can be used to assess the level of disturbances in the flow around a model by incompressible airflow.

  7. Three-Dimensional Modeling and Indoor Positioning for Urban Emergency Response

    Directory of Open Access Journals (Sweden)

    Xin Zhang

    2017-07-01

    Full Text Available Three-dimensional modeling of building environments and indoor positioning is essential for emergency response in cities. Traditional ground-based measurement methods, such as geodetic astronomy, total stations, and global positioning system (GPS receivers, cannot meet the demand for high precision positioning and it is therefore essential to conduct multiple-angle data-acquisition and establish three-dimensional spatial models. In this paper, a rapid modeling technology is introduced, which includes multiple-angle remote sensing image acquisition based on unmanned aerial vehicles (UAVs, an algorithm to remove linear and planar foregrounds before reconstructing the backgrounds, and a three-dimensional modeling (3DM framework. Additionally, an indoor 3DM technology is introduced based on building design drawings, and an indoor positioning technology is developed using iBeacon technology. Finally, a prototype system of the indoor and outdoor positioning-service system in an urban firefighting rescue scenario is introduced to demonstrate the value of the method proposed in this paper.

  8. The Impact of Economic Pressure on Parent Positivity, Parenting, and Adolescent Positivity into Emerging Adulthood.

    Science.gov (United States)

    Neppl, Tricia K; Jeon, Shinyoung; Schofield, Thomas J; Donnellan, M Brent

    2015-02-01

    The current study describes how positivity can be incorporated into the Family Stress Model to explain resilience to disrupted family processes in the face of economic distress. Prospective, longitudinal data came from 451 mothers, fathers, and youth participating from their adolescence through early adulthood. Assessments included observational and self-report measures. Information regarding economic pressure, parental positivity, and parenting were collected during early adolescence, positivity was collected in late adolescence and emerging adulthood. Results indicated that economic pressure was indirectly associated with adolescent positivity through parental positivity. Economic pressure was negatively associated with parent positivity, whereas parental positivity was positively associated with parenting. Moreover, parental positivity and parenting were both related to positivity in adolescence. Results suggest that personal resources linked to a positive outlook can foster nurturant parenting, even in times of economic strain. Such parenting seems to positively influence adolescent development into emerging adulthood.

  9. Indirect methods in nuclear astrophysics

    CERN Document Server

    Bertulani, C A; Mukhamedzhanov, A; Kadyrov, A S; Kruppa, A; Pang, D Y

    2015-01-01

    We discuss recent developments in indirect methods used in nuclear astrophysics to determine the capture cross sections and subsequent rates of various stellar burning processes, when it is difficult to perform the corresponding direct measurements. We discuss in brief, the basic concepts of Asymptotic Normalization Coefficients, the Trojan Horse Method, the Coulomb Dissociation Method, (d,p), and charge-exchange reactions.

  10. Positive and negative relationship between anxiety and depression of patients in pain: a bifactor model analysis.

    Directory of Open Access Journals (Sweden)

    Jingdan Xie

    Full Text Available BACKGROUND: The relationship between anxiety and depression in pain patients has not been clarified comprehensively. Previous research has identified a common factor in anxiety and depression, which may explain why depression and anxiety are strongly correlated. However, the specific clinical features of anxiety and depression seem to pull in opposite directions. OBJECTIVE: The purpose of this study is to develop a statistical model of depression and anxiety, based on data from pain patients using Hospital Anxiety and Depression Scale (HADS. This model should account for the positive correlation between depression and anxiety in terms of a general factor and also demonstrate a latent negative correlation between the specific factors underlying depression and anxiety. METHODS: The anxiety and depression symptoms of pain patients were evaluated using the HADS and the severity of their pain was assessed with the visual analogue scale (VAS. We developed a hierarchical model of the data using an IRT method called bifactor analysis. In addition, we tested this hierarchical model with model fit comparisons with unidimensional, bidimensional, and tridimensional models. The correlations among anxiety, depression, and pain severity were compared, based on both the bidimensional model and our hierarchical model. RESULTS: The bidimensional model analysis found that there was a large positive correlation between anxiety and depression (r = 0.638, and both scores were significantly positively correlated with pain severity. After extracting general factor of distress using bifactor analysis, the specific factors underlying anxiety and depression were weakly but significantly negatively correlated (r = -0.245 and only the general factor was significantly correlated with pain severity. Compared with the three first-order models, the bifactor hierarchical model had the best model fit. CONCLUSION: Our results support the hypothesis that apart from distress

  11. 19 CFR 10.776 - Indirect materials.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Indirect materials. 10.776 Section 10.776 Customs... Rules of Origin § 10.776 Indirect materials. Indirect materials are to be disregarded in determining..., except that the cost of such indirect materials may be included in meeting the value-content requirement...

  12. 19 CFR 10.816 - Indirect materials.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Indirect materials. 10.816 Section 10.816 Customs... Rules of Origin § 10.816 Indirect materials. Indirect materials are to be disregarded in determining..., except that the cost of such indirect materials may be included in meeting the value-content requirement...

  13. Global asymptotic stability of positive equilibrium in a 3-species cooperating model with time delay

    Institute of Scientific and Technical Information of China (English)

    WANG Chang-you

    2007-01-01

    The asymptotic behavior of the time-dependent solution for a 3-species cooperating model was investigated with the effects of both diffusion and time delay taken into consideration. We proved the global asymptotic stability of a positive steady-state solution to the model problem by using coupled upper and lower solutions for a more general reaction-diffusion system that gives a common framework for 3-species cooperating model problems. The result of global asymptotic stability implies that the model system coexistence is permanent. Some global asymptotic stability results for 2-species cooperating reaction-diffusion systems are included in the discussion, and some known results are extended.

  14. Positioning accuracy and reliability of GALILEO,integrated GPS-GALILEO system based on single positioning model

    Institute of Scientific and Technical Information of China (English)

    ZHAO Chunmei; OU Jikun; YUAN Yunbin

    2005-01-01

    A kind of uniform reliability index suitable for the code and phase observations is presented and used in reliability evaluation of satellite systems. Then, based on 25 stations of Crustal Movement Observation Network of China, satellite visibility, positioning availability and observation reliability of GPS, GALILEO and integrated GPS- GALILEO are calculated and analyzed in detail. Simulation results reveal that the satellite visibility of GALILEO is superior to that of GPS. Given positioning accuracy, horizontal positioning availability of GALILEO is consistent with that of GPS, but its vertical positioning availability is superior to that of GPS. However, the integrated GPS-GALILEO is shown to be superior to each of the single systems in the aspects of positioning accuracy and availability. The reliability of code and phase observations based on GALILEO and integrated GPS-GALILEO system is superior to that of GPS both in spatial and temporal domains on the whole. The new reliability index presented is simple to calculate and reflects reliability differences of different satellite systems.

  15. Investigation on semi-direct and indirect climate effects of fossil fuel black carbon aerosol over China

    Science.gov (United States)

    Zhuang, Bingliang; Liu, Qian; Wang, Tijian; Yin, Changqin; Li, Shu; Xie, Min; Jiang, Fei; Mao, Huiting

    2013-11-01

    A Regional Climate Chemistry Modeling System that employed empirical parameterizations of aerosol-cloud microphysics was applied to investigate the spatial distribution, radiative forcing (RF), and climate effects of black carbon (BC) over China. Results showed high levels of BC in Southwest, Central, and East China, with maximum surface concentrations, column burden, and optical depth (AOD) up to 14 μg m-3, 8 mg m-2, and 0.11, respectively. Black carbon was found to result in a positive RF at the top of the atmosphere (TOA) due to its direct effect while a negative RF due to its indirect effect. The regional-averaged direct and indirect RF of BC in China was about +0.81 and -0.95 W m-2, respectively, leading to a net RF of -0.15 W m-2 at the TOA. The BC indirect RF was larger than its direct RF in South China. Due to BC absorption of solar radiation, cloudiness was decreased by 1.33 %, further resulting in an increase of solar radiation and subsequently a surface warming over most parts of China, which was opposite to BC's indirect effect. Further, the net effect of BC might cause a decrease of precipitation of -7.39 % over China. Investigations also suggested large uncertainties and non-linearity in BC's indirect effect on regional climate. Results suggested that: (a) changes in cloud cover might be more affected by BC's direct effect, while changes in surface air temperature and precipitation might be influenced by BC's indirect effect; and (b) BC second indirect effect might have more influence on cloud cover and water content compared to first indirect effect. This study highlighted a substantial role of BC on regional climate changes.

  16. Discovering relations between indirectly connected biomedical concepts.

    Science.gov (United States)

    Weissenborn, Dirk; Schroeder, Michael; Tsatsaronis, George

    2015-01-01

    The complexity and scale of the knowledge in the biomedical domain has motivated research work towards mining heterogeneous data from both structured and unstructured knowledge bases. Towards this direction, it is necessary to combine facts in order to formulate hypotheses or draw conclusions about the domain concepts. This work addresses this problem by using indirect knowledge connecting two concepts in a knowledge graph to discover hidden relations between them. The graph represents concepts as vertices and relations as edges, stemming from structured (ontologies) and unstructured (textual) data. In this graph, path patterns, i.e. sequences of relations, are mined using distant supervision that potentially characterize a biomedical relation. It is possible to identify characteristic path patterns of biomedical relations from this representation using machine learning. For experimental evaluation two frequent biomedical relations, namely "has target", and "may treat", are chosen. Results suggest that relation discovery using indirect knowledge is possible, with an AUC that can reach up to 0.8, a result which is a great improvement compared to the random classification, and which shows that good predictions can be prioritized by following the suggested approach. Analysis of the results indicates that the models can successfully learn expressive path patterns for the examined relations. Furthermore, this work demonstrates that the constructed graph allows for the easy integration of heterogeneous information and discovery of indirect connections between biomedical concepts.

  17. Virtue ethics, positive psychology, and a new model of science and engineering ethics education.

    Science.gov (United States)

    Han, Hyemin

    2015-04-01

    This essay develops a new conceptual framework of science and engineering ethics education based on virtue ethics and positive psychology. Virtue ethicists and positive psychologists have argued that current rule-based moral philosophy, psychology, and education cannot effectively promote students' moral motivation for actual moral behavior and may even lead to negative outcomes, such as moral schizophrenia. They have suggested that their own theoretical framework of virtue ethics and positive psychology can contribute to the effective promotion of motivation for self-improvement by connecting the notion of morality and eudaimonic happiness. Thus this essay attempts to apply virtue ethics and positive psychology to science and engineering ethics education and to develop a new conceptual framework for more effective education. In addition to the conceptual-level work, this essay suggests two possible educational methods: moral modeling and involvement in actual moral activity in science and engineering ethics classes, based on the conceptual framework.

  18. Model based methods for rotor position detection of doubly-fed induction generator

    DEFF Research Database (Denmark)

    Zhu, Rongwu; Chen, Zhe; Zhang, Yunqian;

    2014-01-01

    Model based strategy to detect the initial position angle of doubly-fed induction generator (DFIG) is proposed in this paper. As the stator windings are open-circuit when the wind speed is below the cut-in speed, the stator flux is determined by both rotor position and currents. Based...... on the characteristic, the initial position angle of the rotor is derived by rotor voltage injection (RVI) method and rotor current close loop injection (RCCLI) method, respectively. Further, the two methods are validated by a scaled-down 7.5kW DFIG setup, and the results clearly show that with the RCCLI, the rotor...... initial position of DFIG can be accurately and fast detected for a DFIG with rated parameters and rotor resistance deviations....

  19. Examining item-position effects in large-scale assessment using the Linear Logistic Test Model

    Directory of Open Access Journals (Sweden)

    CHRISTINE HOHENSINN

    2008-09-01

    Full Text Available When administering large-scale assessments, item-position effects are of particular importance because the applied test designs very often contain several test booklets with the same items presented at different test positions. Establishing such position effects would be most critical; it would mean that the estimated item parameters do not depend exclusively on the items’ difficulties due to content but also on their presentation positions. As a consequence, item calibration would be biased. By means of the linear logistic test model (LLTM, item-position effects can be tested. In this paper, the results of a simulation study demonstrating how LLTM is indeed able to detect certain position effects in the framework of a large-scale assessment are presented first. Second, empirical item-position effects of a specific large-scale competence assessment in mathematics (4th grade students are analyzed using the LLTM. The results indicate that a small fatigue effect seems to take place. The most important consequence of the given paper is that it is advisable to try pertinent simulation studies before an analysis of empirical data takes place; the reason is, that for the given example, the suggested Likelihood-Ratio test neither holds the nominal type-I-risk, nor qualifies as “robust”, and furthermore occasionally shows very low power.

  20. A Trend Analysis of Competition Positioning in Chinese Seaports by Using DEA Model and BCG Matrix

    Institute of Scientific and Technical Information of China (English)

    Hoki Nam

    2007-01-01

    <正>This paper has shown the trend of competition positioning of ten critical Chinese seaports from 2003 to 2006 by using DEA model for the performance efficiency analysis and BCG matrix,which consists of relative market share and growth rate as well as the scores of both BCC and CCR in the vertical and horizontal axis of BCG matrix.The expected results will include the total economic efficiency ranking of each Chinese seaport,and the relative competitive positioning in terms of growth rate and efficiency scores.The main policy implication of this paper is to emphasize the DEA model and BCG matrix method can support the seaport managers the basic information for planning the future port management for enhancing the competitive positioning among Chinese seaports.

  1. Electromagnetic modeling of an eddy-current position sensor for use in a fast reactor

    Science.gov (United States)

    Wu, Tao; Bowler, John R.

    2017-02-01

    In this article, we proposed a novel theoretical electromagnetic model of an eddy current probe used as a position sensor with respect to a tube in a fast reactor under standby conditions. In these circumstances the coil position cannot be guided by optical aids but electromagnetic sensing can be used. Initially, we derived analytical expressions for the quasi-static time-harmonic electromagnetic field of a circular current filament via the transverse magnetic potential expressed in terms of a single layer potential. This is then used to deduce the field of a circular sensor coil near a conductive tube, the axis of the coil having an arbitrary direction with respect to that of the tube. The fields for an external coil have been determined and can be used to deduce coil impedance variations with frequency, location and orientation. The model predictions can be used to guide the probe to a desire position with respect to the tube.

  2. Asymmetric and Non–Positive Definite Distance Functions Part II: Modeling

    Directory of Open Access Journals (Sweden)

    H. Sánchez–Larios

    2009-01-01

    Full Text Available Traditionally the distance functions involved in problems of Operations Research have been modeled using positive linear combinations of metrics Lp. Thus, the resulting distance functions are symmetric, uniforms and positive definite. Starting from a new definition of arc length, we propose a method formo deling generalized distance functions, that we call premetrics, which can be asymmetric, non uniform, and non positive definite. We show that every distance function satisfying the triangle inequality and having a continuous one–sided directional derivative can be modeled as a problem of calculus of variations. The "length" of a d–geodesic arc C(a,b from a to b with respect to the premetric d (the d–length can be negative, and therefore the d–distance from a to b may represent the minimum energy needed to move a mobile object from a to b. We illustrate our method with two examples.

  3. On the Relationship between Bonding Theory and Youth Gang Resistance in U.S. 8th Graders: Competing Structural Equation Models with Latent Structure Indirect Effects

    Science.gov (United States)

    Vander Horst, Anthony

    2012-01-01

    In a study of 5285 8th graders from the Gang Resistance and Education Training (G.R.E.A.T.) research, this study applied Travis Hirschi's social bonding theory to examine the curriculum's efficacy in increasing conventional bonding (friends with positive peers, succeeding at education etc.) and decreasing non-conventional bonding (drug…

  4. Modelling dynamics and aerodynamic tests of a sport parachute jumper during flight in sitfly position.

    Science.gov (United States)

    Moniuszko, Justyna; Maryniak, Jerzy; Ladyżyńska-Kozdraś, Edyta

    2010-01-01

    Based on a model of a parachute jumper, for various body configurations in a sitting position, tests were carried out in an aerodynamic tunnel. Aerodynamic characteristics and dimensionless aerodynamic forces' coefficients were calculated. The tests were carried out for various configurations of the jumper's body. A universal mathematical model of a parachute jumper's body was prepared, thus enabling the analysis of the jumper's movement with a closed parachute in any position. In order to build the model, a digitized model of a jumper allowing changing the body configuration, making appropriate changes of the moment of inertia, distribution of the center of mass and the aerodynamic characteristics was adopted. Dynamic movement equations were derived for a jumper in a relative reference system. The mathematical model was formulated for a jumper with a variable body configuration during the flight, which can be realized through a change of the position and the speed of the parachute jumper's limbs. The model allows analyzing the motion of the jumper with a closed parachute. It is an important jump phase during an assault with delayed parachute opening in sports type jumping, e.g., Skydiving and in emergency jumps from higher altitudes for the parachute's opening to be safe.

  5. Indirect Over-Time Relations Between Parenting and Adolescents' Sexual Behaviors and Emotions Through Global Self-Esteem.

    Science.gov (United States)

    van de Bongardt, Daphne; Reitz, Ellen; Deković, Maja

    2016-01-01

    The present study examined indirect over-time relations between parenting and adolescent sexuality through global self-esteem. Three waves of online questionnaire data were collected among a community sample of 1,116 Dutch adolescents (M = 13.9 years at baseline). Participants rated the quality of their relationship with parents, their global self-esteem, and their experience with various sexual behaviors. Sexually experienced adolescents (n = 168) evaluated their sexual experiences using six emotions. Path model results showed that a higher-quality relationship with parents at T1 predicted higher levels of self-esteem at T2, which in turn predicted less experience with sexual behaviors and more positive sexual emotions at T3. The indirect over-time path from relationship quality through self-esteem to adolescents' sexual emotions was significant; the indirect path to adolescents' experience with sexual behaviors was not significant at the .05 level. No significant age or gender differences were found in the path models. The findings indicate that self-esteem plays an important role in adolescent sexuality and that parents can contribute to positive sexual experiences of adolescents indirectly--through the enhancement of self-esteem--by fostering a high-quality relationship with their children. Implications for theory, future research, and strategies to promote healthy and positive youth sexuality are discussed.

  6. Person Focused Training: A Model for Delivering Positive Behavioural Supports to People with Challenging Behaviours

    Science.gov (United States)

    McClean, B.; Dench, C.; Grey, I.; Shanahan, S.; Fitzsimons, E.; Hendler, J.; Corrigan, M.

    2005-01-01

    Person Focused Training is introduced as a model of service delivery for people with severe challenging behaviours. It is defined as training and supporting staff to conduct functional assessments and to design and implement positive behavioural support for specific individuals with challenging behaviours. Longitudinal outcome data are presented…

  7. Applying the Nominal Response Model within a Longitudinal Framework to Construct the Positive Family Relationships Scale

    Science.gov (United States)

    Preston, Kathleen Suzanne Johnson; Parral, Skye N.; Gottfried, Allen W.; Oliver, Pamella H.; Gottfried, Adele Eskeles; Ibrahim, Sirena M.; Delany, Danielle

    2015-01-01

    A psychometric analysis was conducted using the nominal response model under the item response theory framework to construct the Positive Family Relationships scale. Using data from the Fullerton Longitudinal Study, this scale was constructed within a long-term longitudinal framework spanning middle childhood through adolescence. Items tapping…

  8. Effects of Electrode Position on Spatiotemporal Auditory Nerve Fiber Responses: A 3D Computational Model Study

    Directory of Open Access Journals (Sweden)

    Soojin Kang

    2015-01-01

    Full Text Available A cochlear implant (CI is an auditory prosthesis that enables hearing by providing electrical stimuli through an electrode array. It has been previously established that the electrode position can influence CI performance. Thus, electrode position should be considered in order to achieve better CI results. This paper describes how the electrode position influences the auditory nerve fiber (ANF response to either a single pulse or low- (250 pulses/s and high-rate (5,000 pulses/s pulse-trains using a computational model. The field potential in the cochlea was calculated using a three-dimensional finite-element model, and the ANF response was simulated using a biophysical ANF model. The effects were evaluated in terms of the dynamic range, stochasticity, and spike excitation pattern. The relative spread, threshold, jitter, and initiated node were analyzed for single-pulse response; and the dynamic range, threshold, initiated node, and interspike interval were analyzed for pulse-train stimuli responses. Electrode position was found to significantly affect the spatiotemporal pattern of the ANF response, and this effect was significantly dependent on the stimulus rate. We believe that these modeling results can provide guidance regarding perimodiolar and lateral insertion of CIs in clinical settings and help understand CI performance.

  9. Positive expectations feedback experiments and number guessing games as models of financial markets

    NARCIS (Netherlands)

    Sonnemans, J.; Tuinstra, J.

    2010-01-01

    In repeated number guessing games choices typically converge quickly to the Nash equilibrium. In positive expectations feedback experiments, however, convergence to the equilibrium price tends to be very slow, if it occurs at all. Both types of experimental designs have been suggested as modeling es

  10. Modeling and Assessment of GPS/BDS Combined Precise Point Positioning.

    Science.gov (United States)

    Chen, Junping; Wang, Jungang; Zhang, Yize; Yang, Sainan; Chen, Qian; Gong, Xiuqiang

    2016-07-22

    Precise Point Positioning (PPP) technique enables stand-alone receivers to obtain cm-level positioning accuracy. Observations from multi-GNSS systems can augment users with improved positioning accuracy, reliability and availability. In this paper, we present and evaluate the GPS/BDS combined PPP models, including the traditional model and a simplified model, where the inter-system bias (ISB) is treated in different way. To evaluate the performance of combined GPS/BDS PPP, kinematic and static PPP positions are compared to the IGS daily estimates, where 1 month GPS/BDS data of 11 IGS Multi-GNSS Experiment (MGEX) stations are used. The results indicate apparent improvement of GPS/BDS combined PPP solutions in both static and kinematic cases, where much smaller standard deviations are presented in the magnitude distribution of coordinates RMS statistics. Comparisons between the traditional and simplified combined PPP models show no difference in coordinate estimations, and the inter system biases between the GPS/BDS system are assimilated into receiver clock, ambiguities and pseudo-range residuals accordingly.

  11. Culturally Responsive Pyramid Model Practices: Program-Wide Positive Behavior Support for Young Children

    Science.gov (United States)

    Allen, Rosemarie; Steed, Elizabeth A.

    2016-01-01

    This conceptual article reviews current research on racial disparities in disciplinary practices in early childhood education and work to address these issues within a positive behavior support (PBS) framework. Building largely on the Pyramid Model, recommendations and a culturally responsive approach are suggested for use within a program-wide…

  12. The Role of Wellbeing and Wellness: A Positive Psychological Model in Supporting Young People With ASCs

    Directory of Open Access Journals (Sweden)

    Irina Roncaglia

    2017-04-01

    Full Text Available In the last 10 years sport psychology expanded its applicability in a variety of fields which have helped to address some of the challenges related to high level performance and sport competition. When we talk about performance in its wider sense, sport psychology is able to help develop a better understanding on how strategies can be adopted in improving general human performance levels. This includes increasing the knowledge of key concepts such as motivation, self-confidence and resilience. Furthermore performance in its wider sense helps in the understanding of the impact of stress and arousal and how these can affect both positively and negatively performance levels including appreciating individual differences as well as dynamics between groups of individuals. In this paper performance rather than solely be related to the field of competitive or professional sport has been discussed in people with ASCs and aims to explore how by adopting a positive psychological model in the formulation of individual assessments and subsequent interventions have led to improvement in individual skills, participation, engagement and ultimately quality of life. Positive psychological principles, such as the role of wellbeing and wellness, the PERMA Model has increased our understanding of human potentials, performance and wellbeing. The aim of this paper is to present and reflect on the applicability and benefits of adopting sport psychology models, the PERMA model and positive psychological principles in special education and care settings with the presentation and discussion of their theoretical and some practical implementation in two case studies.

  13. Airbag modelling for Out-of-Position: numerical approach and advanced airbag testing

    NARCIS (Netherlands)

    Rekveldt, M.G.C.; Swartjes, F.H.M.; Steenbrink, A.C.

    2002-01-01

    There is an increasing pressure to reduce injuries and fatalities by effectively using airbags for side impact and out-of-position impact loading conditions. Numerical simulation, as an essential design tool for airbags, requires accuate models applicable to the various OOP loading cases. In this pa

  14. Structures airbag modelling for Out-of-Position: numerical approach and advanced airbag testing

    NARCIS (Netherlands)

    Rekveldt, M.G.C.; Lemmen, P.P.M.; Swartjes, F.H.M.

    2002-01-01

    There is an increasing pressure to reduce injuries and fatalities by effectively using airbags for side impact and out-of-position impact loading conditions. Numerical simulation, as an essential design tool for airbags, requires accurate models applicable to the many OOP loading cases. In this pape

  15. Global Attractivity of Positive Periodic Solutions for a Survival Model of Red Blood Cells

    Institute of Scientific and Technical Information of China (English)

    Xin-min Wu; Jing-wen Li

    2007-01-01

    In this paper, we deal with a model for the survival of red blood cells with periodic coefficients x′(t)=- μ(t)x(t)+P(t)e-γ(t)x(t-(τ))>0. (*)A new sufficient condition for global attractivity of positive periodic solutions of Eq.(*) is obtained. Our criterion improves corresponding result obtained by Li and Wang in 2005.

  16. Constructing Positive Futures: Modeling the Relationship between Adolescents' Hopeful Future Expectations and Intentional Self Regulation in Predicting Positive Youth Development

    Science.gov (United States)

    Schmid, Kristina L.; Phelps, Erin; Lerner, Richard M.

    2011-01-01

    Intentional self regulation and hopeful expectations for the future are theoretically-related constructs shown to lead to positive youth development (PYD). However, the nature of their relationship over time has not been tested. Therefore, this study explored the associations between hopeful future expectations and intentional self regulation in…

  17. Constructing Positive Futures: Modeling the Relationship between Adolescents' Hopeful Future Expectations and Intentional Self Regulation in Predicting Positive Youth Development

    Science.gov (United States)

    Schmid, Kristina L.; Phelps, Erin; Lerner, Richard M.

    2011-01-01

    Intentional self regulation and hopeful expectations for the future are theoretically-related constructs shown to lead to positive youth development (PYD). However, the nature of their relationship over time has not been tested. Therefore, this study explored the associations between hopeful future expectations and intentional self regulation in…

  18. Application of troposphere model from NWP and GNSS data into real-time precise positioning

    Science.gov (United States)

    Wilgan, Karina; Hadas, Tomasz; Kazmierski, Kamil; Rohm, Witold; Bosy, Jaroslaw

    2016-04-01

    The tropospheric delay empirical models are usually functions of meteorological parameters (temperature, pressure and humidity). The application of standard atmosphere parameters or global models, such as GPT (global pressure/temperature) model or UNB3 (University of New Brunswick, version 3) model, may not be sufficient, especially for positioning in non-standard weather conditions. The possible solution is to use regional troposphere models based on real-time or near-real time measurements. We implement a regional troposphere model into the PPP (Precise Point Positioning) software GNSS-WARP (Wroclaw Algorithms for Real-time Positioning) developed at Wroclaw University of Environmental and Life Sciences. The software is capable of processing static and kinematic multi-GNSS data in real-time and post-processing mode and takes advantage of final IGS (International GNSS Service) products as well as IGS RTS (Real-Time Service) products. A shortcoming of PPP technique is the time required for the solution to converge. One of the reasons is the high correlation among the estimated parameters: troposphere delay, receiver clock offset and receiver height. To efficiently decorrelate these parameters, a significant change in satellite geometry is required. Alternative solution is to introduce the external high-quality regional troposphere delay model to constrain troposphere estimates. The proposed model consists of zenith total delays (ZTD) and mapping functions calculated from meteorological parameters from Numerical Weather Prediction model WRF (Weather Research and Forecasting) and ZTDs from ground-based GNSS stations using the least-squares collocation software COMEDIE (Collocation of Meteorological Data for Interpretation and Estimation of Tropospheric Pathdelays) developed at ETH Zurich.

  19. Performance Analysis of Several GPS/Galileo Precise Point Positioning Models

    Directory of Open Access Journals (Sweden)

    Akram Afifi

    2015-06-01

    Full Text Available This paper examines the performance of several precise point positioning (PPP models, which combine dual-frequency GPS/Galileo observations in the un-differenced and between-satellite single-difference (BSSD modes. These include the traditional un-differenced model, the decoupled clock model, the semi-decoupled clock model, and the between-satellite single-difference model. We take advantage of the IGS-MGEX network products to correct for the satellite differential code biases and the orbital and satellite clock errors. Natural Resources Canada’s GPSPace PPP software is modified to handle the various GPS/Galileo PPP models. A total of six data sets of GPS and Galileo observations at six IGS stations are processed to examine the performance of the various PPP models. It is shown that the traditional un-differenced GPS/Galileo PPP model, the GPS decoupled clock model, and the semi-decoupled clock GPS/Galileo PPP model improve the convergence time by about 25% in comparison with the un-differenced GPS-only model. In addition, the semi-decoupled GPS/Galileo PPP model improves the solution precision by about 25% compared to the traditional un-differenced GPS/Galileo PPP model. Moreover, the BSSD GPS/Galileo PPP model improves the solution convergence time by about 50%, in comparison with the un-differenced GPS PPP model, regardless of the type of BSSD combination used. As well, the BSSD model improves the precision of the estimated parameters by about 50% and 25% when the loose and the tight combinations are used, respectively, in comparison with the un-differenced GPS-only model. Comparable results are obtained through the tight combination when either a GPS or a Galileo satellite is selected as a reference.

  20. Performance Analysis of Several GPS/Galileo Precise Point Positioning Models.

    Science.gov (United States)

    Afifi, Akram; El-Rabbany, Ahmed

    2015-06-19

    This paper examines the performance of several precise point positioning (PPP) models, which combine dual-frequency GPS/Galileo observations in the un-differenced and between-satellite single-difference (BSSD) modes. These include the traditional un-differenced model, the decoupled clock model, the semi-decoupled clock model, and the between-satellite single-difference model. We take advantage of the IGS-MGEX network products to correct for the satellite differential code biases and the orbital and satellite clock errors. Natural Resources Canada's GPSPace PPP software is modified to handle the various GPS/Galileo PPP models. A total of six data sets of GPS and Galileo observations at six IGS stations are processed to examine the performance of the various PPP models. It is shown that the traditional un-differenced GPS/Galileo PPP model, the GPS decoupled clock model, and the semi-decoupled clock GPS/Galileo PPP model improve the convergence time by about 25% in comparison with the un-differenced GPS-only model. In addition, the semi-decoupled GPS/Galileo PPP model improves the solution precision by about 25% compared to the traditional un-differenced GPS/Galileo PPP model. Moreover, the BSSD GPS/Galileo PPP model improves the solution convergence time by about 50%, in comparison with the un-differenced GPS PPP model, regardless of the type of BSSD combination used. As well, the BSSD model improves the precision of the estimated parameters by about 50% and 25% when the loose and the tight combinations are used, respectively, in comparison with the un-differenced GPS-only model. Comparable results are obtained through the tight combination when either a GPS or a Galileo satellite is selected as a reference.

  1. Indirect reciprocity and the evolution of "moral signals"

    Science.gov (United States)

    Smead, Rory

    2010-01-01

    Signals regarding the behavior of others are an essential element of human moral systems and there are important evolutionary connections between language and large-scale cooperation. In particular, social communication may be required for the reputation tracking needed to stabilize indirect reciprocity. Additionally, scholars have suggested that the benefits of indirect reciprocity may have been important for the evolution of language and that social signals may have coevolved with large-scale cooperation. This paper investigates the possibility of such a coevolution. Using the tools of evolutionary game theory, we present a model that incorporates primitive "moral signaling" into a simple setting of indirect reciprocity. This model reveals some potential difficulties for the evolution of "moral signals." We find that it is possible for "moral signals" to evolve alongside indirect reciprocity, but without some external pressure aiding the evolution of a signaling system, such a coevolution is unlikely.

  2. Predictors of negotiated NIH indirect rates at US institutions.

    Directory of Open Access Journals (Sweden)

    S Claiborne Johnston

    Full Text Available The United States (US Department of Health and Human Services and the Office of Naval Research negotiate institutional rates for payments of overhead costs associated with administration and space usage, commonly known as indirect rates. Such payments account for a large proportion of spending by the National Institutes of Health (NIH. Little has been published about differences in rates and their predictors.Negotiated indirect rates for on-campus research grants were requested from the Council on Governmental Relations for the 100 institutions with greatest NIH funding in 2010. NIH funding, cost of living (ACCRA Index for 2008, public vs. private status, negotiating governmental organization (Department of Health and Human Services or Office of Naval Research, US Census Region, and year were assessed as predictors of institutional indirect rates using generalized estimating equations with all variables included in the model.Overall, 72 institutions participated, with 207 reported indirect rates for the years 2006, 2008, and 2010. Indirect rates ranged from 36.3% to 78%, with an average of 54.5%. Mean rates increased from 53.6% in 2006 to 55.4% in 2010 (p<0.001. In multivariable models, private institutions had 6.2% (95% CI 3.7%-8.7%; p<0.001 higher indirect rates than public institutions. Rates in the Northeast were highest (Midwest 4.0% lower; West 4.9% lower; South 5.2% lower. Greater NIH funding (p = 0.025 and cost of living (p = 0.034 also predicted indirect rates while negotiating governmental organization did not (p = 0.414.Negotiated indirect rates for governmental research grants to academic centers vary widely. Although the association between indirect rates and cost of living may be justified, the cause of variation in rates by region, public-private status, and NIH funding levels is unclear.

  3. MODELLING THE POSITION OF CELL PROFILES ALLOWING FOR BOTH INHOMOGENEITY AND INTERACTION

    Directory of Open Access Journals (Sweden)

    Linda Stougaard Nielsen

    2011-05-01

    Full Text Available It is of interest to consider models for point processes that allow for interaction between the points as well as for inhomogeneity in the intensity of the points. Markov point process models are very useful to describe point interaction and can also be used to describe inhomogeneity. A particular type of inhomogeneous Markov point processes obtained by transforming a homogeneous Markov point process will be considered. The position of cell proles in a 2D section of the mucous membrane in the stomach of a rat will be examined using this model.

  4. Propagator with Positive Cosmological Constant in the 3D Euclidian Quantum Gravity Toy Model

    CERN Document Server

    Bunting, William

    2014-01-01

    We study the propagator on a single tetrahedron in a three dimensional toy model of quantum gravity with positive cosmological constant. The cosmological constant is included in the model via q-deformation of the spatial symmetry algebra, that is, we use the Tuarev-Viro amplitude. The expected repulsive effect of dark energy is recovered in numerical and analytic calculations of the propagator at large scales comparable to the infrared cutoff. However, due to the simplicity of the model we do not obtain the exact Newton limit of the propagator. This is a first step toward the similar calculation in the full 3+1 dimensional theory with larger numbers of simplicies.

  5. Vibratory response modeling and verification of a high precision optical positioning system.

    Energy Technology Data Exchange (ETDEWEB)

    Barraza, J.; Kuzay, T.; Royston, T. J.; Shu, D.

    1999-06-18

    A generic vibratory-response modeling program has been developed as a tool for designing high-precision optical positioning systems. Based on multibody dynamics theory, the system is modeled as rigid-body structures connected by linear elastic elements, such as complex actuators and bearings. The full dynamic properties of each element are determined experimentally or theoretically, then integrated into the program as inertial and stiffness matrices. Utilizing this program, the theoretical and experimental verification of the vibratory behavior of a double-multilayer monochromator support and positioning system is presented. Results of parametric design studies that investigate the influence of support floor dynamics and highlight important design issues are also presented. Overall, good matches between theory and experiment demonstrate the effectiveness of the program as a dynamic modeling tool.

  6. Experimental investigation and numerical modelling of positive corona discharge: ozone generation

    Science.gov (United States)

    Yanallah, K; Pontiga, F; Fernández-Rueda, A; Castellanos, A

    2009-03-01

    The spatial distribution of the species generated in a wire-cylinder positive corona discharge in pure oxygen has been computed using a plasma chemistry model that includes the most significant reactions between electrons, ions, atoms and molecules. The plasma chemistry model is included in the continuity equations of each species, which are coupled with Poisson's equation for the electric field and the energy conservation equation for the gas temperature. The current-voltage characteristic measured in the experiments has been used as an input data to the numerical simulation. The numerical model is able to reproduce the basic structure of the positive corona discharge and highlights the importance of Joule heating on ozone generation. The average ozone density has been computed as a function of current intensity and compared with the experimental measurements of ozone concentration determined by UV absorption spectroscopy.

  7. Experimental investigation and numerical modelling of positive corona discharge: ozone generation

    Energy Technology Data Exchange (ETDEWEB)

    Yanallah, K; Castellanos, A [Departamento de Electronica y Electromagnetismo, Universidad de Sevilla (Spain); Pontiga, F; Fernandez-Rueda, A [Departamento de FIsica Aplicada II, Universidad de Sevilla (Spain)

    2009-03-21

    The spatial distribution of the species generated in a wire-cylinder positive corona discharge in pure oxygen has been computed using a plasma chemistry model that includes the most significant reactions between electrons, ions, atoms and molecules. The plasma chemistry model is included in the continuity equations of each species, which are coupled with Poisson's equation for the electric field and the energy conservation equation for the gas temperature. The current-voltage characteristic measured in the experiments has been used as an input data to the numerical simulation. The numerical model is able to reproduce the basic structure of the positive corona discharge and highlights the importance of Joule heating on ozone generation. The average ozone density has been computed as a function of current intensity and compared with the experimental measurements of ozone concentration determined by UV absorption spectroscopy.

  8. Ant colony optimization algorithm for continuous domains based on position distribution model of ant colony foraging.

    Science.gov (United States)

    Liu, Liqiang; Dai, Yuntao; Gao, Jinyu

    2014-01-01

    Ant colony optimization algorithm for continuous domains is a major research direction for ant colony optimization algorithm. In this paper, we propose a distribution model of ant colony foraging, through analysis of the relationship between the position distribution and food source in the process of ant colony foraging. We design a continuous domain optimization algorithm based on the model and give the form of solution for the algorithm, the distribution model of pheromone, the update rules of ant colony position, and the processing method of constraint condition. Algorithm performance against a set of test trials was unconstrained optimization test functions and a set of optimization test functions, and test results of other algorithms are compared and analyzed to verify the correctness and effectiveness of the proposed algorithm.

  9. Ant Colony Optimization Algorithm for Continuous Domains Based on Position Distribution Model of Ant Colony Foraging

    Directory of Open Access Journals (Sweden)

    Liqiang Liu

    2014-01-01

    Full Text Available Ant colony optimization algorithm for continuous domains is a major research direction for ant colony optimization algorithm. In this paper, we propose a distribution model of ant colony foraging, through analysis of the relationship between the position distribution and food source in the process of ant colony foraging. We design a continuous domain optimization algorithm based on the model and give the form of solution for the algorithm, the distribution model of pheromone, the update rules of ant colony position, and the processing method of constraint condition. Algorithm performance against a set of test trials was unconstrained optimization test functions and a set of optimization test functions, and test results of other algorithms are compared and analyzed to verify the correctness and effectiveness of the proposed algorithm.

  10. The Position and Attitude of Sub-reflector Modeling for TM65 m Radio Telescope

    Science.gov (United States)

    Sun, Z. X.; Chen, L.; Wang, J. Q.

    2016-01-01

    In the course of astronomical observations, with changes in angle of pitch, the large radio telescope will have different degrees of deformation in the sub-reflector support, back frame, main reflector etc, which will lead to the dramatic decline of antenna efficiency in both high and low elevation. A sub-reflector system of the Tian Ma 65 m radio telescope has been installed in order to compensate for the gravitational deformations of the sub-reflector support and the main reflector. The position and attitude of the sub-reflector are variable in order to improve the pointing performance and the efficiency at different elevations. In this paper, it is studied that the changes of position and attitude of the sub-reflector have influence on the efficiency of antenna in the X band and Ku band. A model has been constructed to determine the position and attitude of the sub-reflector with elevation, as well as the point compensation model, by observing the radio source. In addition, antenna efficiency was tested with sub-reflector position adjusted and fixed. The results show that the model of sub-reflector can effectively improve the efficiency of the 65 m radio telescope. In X band, the aperture efficiency of the radio telescope reaches more than 60% over the entire elevation range.

  11. Effects on lung stress of position and different doses of perfluorocarbon in a model of ARDS.

    Science.gov (United States)

    López-Aguilar, Josefina; Lucangelo, Umberto; Albaiceta, Guillermo M; Nahum, Avi; Murias, Gastón; Cañizares, Rosario; Oliva, Joan Carles; Romero, Pablo V; Blanch, Lluís

    2015-05-01

    We determined whether the combination of low dose partial liquid ventilation (PLV) with perfluorocarbons (PFC) and prone positioning improved lung function while inducing minimal stress. Eighteen pigs with acute lung injury were assigned to conventional mechanical ventilation (CMV) or PLV (5 or 10 ml/kg of PFC). Positive end-expiratory pressure (PEEP) trials in supine and prone positions were performed. Data were analyzed by a multivariate polynomial regression model. The interplay between PLV and position depended on the PEEP level. In supine PLV dampened the stress induced by increased PEEP during the trial. The PFC dose of 5 ml/kg was more effective than the dose 10 ml/kg. This effect was not observed in prone. Oxygenation was significantly higher in prone than in supine position mainly at lower levels of PEEP. In conclusion, MV settings should take both gas exchange and stress/strain into account. When protective CMV fails, rescue strategies combining prone positioning and PLV with optimal PEEP should improve gas exchange with minimal stress.

  12. Indoor Localisation Using a Context-Aware Dynamic Position Tracking Model

    Directory of Open Access Journals (Sweden)

    Montserrat Ros

    2012-01-01

    Full Text Available Indoor wireless localisation is a widely sought feature for use in logistics, health, and social networking applications. Low-powered localisation will become important for the next generation of pervasive media applications that operate on mobile platforms. We present an inexpensive and robust context-aware tracking system that can track the position of users in an indoor environment, using a wireless smart meter network. Our context-aware tracking system combines wireless trilateration with a dynamic position tracking model and a probability density map to estimate indoor positions. The localisation network consisted of power meter nodes placed at known positions in a building. The power meter nodes are tracked by mobile nodes which are carried by users to localise their position. We conducted an extensive trial of the context-aware tracking system and performed a comparison analysis with existing localisation techniques. The context-aware tracking system was able to localise a person's indoor position with an average error of 1.21 m.

  13. Evaluation of ECHO PS Positioning System in a Porcine Model of Simulated Laparoscopic Ventral Hernia Repair.

    Science.gov (United States)

    Hanna, Erin M; Voeller, Guy R; Roth, J Scott; Scott, Jeffrey R; Gagne, Darcy H; Iannitti, David A

    2013-01-01

    Purpose. Operative efficiency improvements for laparoscopic ventral hernia repair (LVHR) have focused on reducing operative time while maintaining overall repair efficacy. Our objective was to evaluate procedure time and positioning accuracy of an inflatable mesh positioning device (Echo PS Positioning System), as compared to a standard transfascial suture technique, using a porcine model of simulated LVHR. Methods. The study population consisted of seventeen general surgeons (n = 17) that performed simulated LVHR on seventeen (n = 17) female Yorkshire pigs using two implantation techniques: (1) Ventralight ST Mesh + Echo PS Positioning System (Echo PS) and (2) Ventralight ST Mesh + transfascial sutures (TSs). Procedure time and mesh centering accuracy overtop of a simulated surgical defect were evaluated. Results. Echo PS demonstrated a 38.9% reduction in the overall procedure time, as compared to TS. During mesh preparation and positioning, Echo PS demonstrated a 60.5% reduction in procedure time (P Echo PS (16.2%), this was not significantly different than TS. Conclusions. Echo PS demonstrated a significant reduction in overall simulated LVHR procedure time, particularly during mesh preparation/positioning. These operative time savings may translate into reduced operating room costs and improved surgeon/operating room efficiency.

  14. Able but unintelligent: including positively stereotyped black subgroups in the stereotype content model.

    Science.gov (United States)

    Walzer, Amy S; Czopp, Alexander M

    2011-01-01

    The stereotype content model (SCM) posits that warmth and competence are the key components underlying judgments about social groups. Because competence can encompass different components (e.g., intelligence, talent) different group members may be perceived to be competent for different reasons. Therefore, we believe it may be important to specify the type of competence being assessed when examining perceptions of groups that are positively stereotyped (i.e., Black athletes and musical Blacks). Consistent with the SCM, these subgroups were perceived as high in competence-talent but not in competence-intelligence and low in warmth. Both the intelligence and talent frame of competence fit in the SCM's social structural hypothesis.

  15. Persuasion Model and Its Evaluation Based on Positive Change Degree of Agent Emotion

    Science.gov (United States)

    Jinghua, Wu; Wenguang, Lu; Hailiang, Meng

    For it can meet needs of negotiation among organizations take place in different time and place, and for it can make its course more rationality and result more ideal, persuasion based on agent can improve cooperation among organizations well. Integrated emotion change in agent persuasion can further bring agent advantage of artificial intelligence into play. Emotion of agent persuasion is classified, and the concept of positive change degree is given. Based on this, persuasion model based on positive change degree of agent emotion is constructed, which is explained clearly through an example. Finally, the method of relative evaluation is given, which is also verified through a calculation example.

  16. Indirect dark matter searches in gamma and cosmic rays

    Science.gov (United States)

    Conrad, Jan; Reimer, Olaf

    2017-03-01

    Dark matter candidates such as weakly interacting massive particles are predicted to annihilate or decay into Standard Model particles, leaving behind distinctive signatures in gamma rays, neutrinos, positrons, antiprotons, or even antinuclei. Indirect dark matter searches, and in particular those based on gamma-ray observations and cosmic-ray measurements, could detect such signatures. Here we review the strengths and limitations of this approach and look into the future of indirect dark matter searches.

  17. Indirect quantum tomography of quadratic Hamiltonians

    Energy Technology Data Exchange (ETDEWEB)

    Burgarth, Daniel [Institute for Mathematical Sciences, Imperial College London, London SW7 2PG (United Kingdom); Maruyama, Koji; Nori, Franco, E-mail: daniel@burgarth.de, E-mail: kmaruyama@riken.jp [Advanced Science Institute, RIKEN, Wako-shi, Saitama 351-0198 (Japan)

    2011-01-15

    A number of many-body problems can be formulated using Hamiltonians that are quadratic in the creation and annihilation operators. Here, we show how such quadratic Hamiltonians can be efficiently estimated indirectly, employing very few resources. We found that almost all the properties of the Hamiltonian are determined by its surface and that these properties can be measured even if the system can only be initialized to a mixed state. Therefore, our method can be applied to various physical models, with important examples including coupled nano-mechanical oscillators, hopping fermions in optical lattices and transverse Ising chains.

  18. Positive Mathematical Programming Approaches – Recent Developments in Literature and Applied Modelling

    Directory of Open Access Journals (Sweden)

    Thomas Heckelei

    2012-05-01

    Full Text Available This paper reviews and discusses the more recent literature and application of Positive Mathematical Programming in the context of agricultural supply models. Specifically, advances in the empirical foundation of parameter specifications as well as the economic rationalisation of PMP models – both criticized in earlier reviews – are investigated. Moreover, the paper provides an overview on a larger set of models with regular/repeated policy application that apply variants of PMP. Results show that most applications today avoid arbitrary parameter specifications and rely on exogenous information on supply responses to calibrate model parameters. However, only few approaches use multiple observations to estimate parameters, which is likely due to the still considerable technical challenges associated with it. Equally, we found only limited reflection on the behavioral or technological assumptions that could rationalise the PMP model structure while still keeping the model’s advantages.

  19. Precise Point Positioning Model Using Triple GNSS Constellations: GPS, Galileo and BeiDou

    Science.gov (United States)

    Afifi, Akram; El-Rabbany, Ahmed

    2016-12-01

    This paper introduces a comparison between dual-frequency precise point positioning (PPP) post-processing model, which combines the observations of three different GNSS constellations, namely GPS, Galileo, and BeiDou and real-time PPP model. A drawback of a single GNSS system such as GPS, however, is the availability of sufficient number of visible satellites in urban areas. Combining GNSS observations offers more visible satellites to users, which in turn is expected to enhance the satellite geometry and the overall positioning solution. However, combining several GNSS observables introduces additional biases, which require rigorous modelling, including the GNSS time offsets and hardware delays. In this paper, a GNSS post-processing PPPP model is developed using ionosphere-free linear combination. The additional biases of the GPS, Galileo, and BeiDou combination are accounted for through the introduction of a new unknown parameter, which is identified as the inter-system bias, in the PPP mathematical model. Natural Resources Canada's GPSPace PPP software is modified to enable a combined GPS / Galileo / BeiDou PPP solution and to handle the newly inter-system bias. A total of four data sets at four IGS stations are processed to verify the developed PPP model. Precise satellite orbit and clock products from the IGS-MGEX network are used to correct of the GPS, Galileo and BeiDou measurements. For the real-time PPP model the corrections of the satellites orbit and clock are obtained through the international GNSS service (IGS) real-time service (RTS). GPS and Galileo Observations are used for the GNSS RTS-IGS PPP model as the RTS-IGS satellite products are not available for BeiDou satellites. This paper provides the GNSS RTS-IGS PPP model using different satellite clock corrections namely: IGS01, IGC01, IGS01, and IGS03. All PPP models results of convergence time and positioning precision are compared to the traditional GPS-only PPP model. It is shown that combining

  20. A Unified Model for BDS Wide Area and Local Area Augmentation Positioning Based on Raw Observations

    Directory of Open Access Journals (Sweden)

    Rui Tu

    2017-03-01

    Full Text Available In this study, a unified model for BeiDou Navigation Satellite System (BDS wide area and local area augmentation positioning based on raw observations has been proposed. Applying this model, both the Real-Time Kinematic (RTK and Precise Point Positioning (PPP service can be realized by performing different corrections at the user end. This algorithm was assessed and validated with the BDS data collected at four regional stations from Day of Year (DOY 080 to 083 of 2016. When the users are located within the local reference network, the fast and high precision RTK service can be achieved using the regional observation corrections, revealing a convergence time of about several seconds and a precision of about 2–3 cm. For the users out of the regional reference network, the global broadcast State-Space Represented (SSR corrections can be utilized to realize the global PPP service which shows a convergence time of about 25 min for achieving an accuracy of 10 cm. With this unified model, it can not only integrate the Network RTK (NRTK and PPP into a seamless positioning service, but also recover the ionosphere Vertical Total Electronic Content (VTEC and Differential Code Bias (DCB values that are useful for the ionosphere monitoring and modeling.

  1. Position Adaptive Measurement Model for Double-four Quadrant Photoelectric Detector

    Institute of Scientific and Technical Information of China (English)

    DANG Li-ping; LIU Jun-hua; TANG Shu-gang; LIU Hong-fei

    2006-01-01

    A modeling method of the support vector machine combined with matrix optics is considered; a complete new measurement model for double-four quadrant photoelectric detector is built. According to the analysis of the received light spot size and its motion with the changes of the defocusing amount of detector photosensitive surface and the detector position attitude in the optical path, a mathematic expression of photoelectrical conversion is given, which can be applicable to random setting position of the detector at any time. Based on least square support vector machine (LS SVM), the mapping relationship among the output signal linear characteristic parameters (zero neighborhood gradient and intercept), the defocusing amount of the detector and the installation position attitude angle is established. Thus, the multiple dimensional high accuracy measuring and adjusting control system can be left out, and adaptive measurement of the detector parameters can be realized. Compared with existed measurement model and method, the presented model has the advantages of more clear physical meaning, closer to work mechanism of detector, acquiring more complete sample data and wiping out the dead spots or bad spots in measurement. And the accuracy of displacement measurement is increased to 3 μm. At the same time, this measurement mode provides a technical shortcut for three-dimensional small angle measurement.

  2. A Unified Model for BDS Wide Area and Local Area Augmentation Positioning Based on Raw Observations.

    Science.gov (United States)

    Tu, Rui; Zhang, Rui; Lu, Cuixian; Zhang, Pengfei; Liu, Jinhai; Lu, Xiaochun

    2017-03-03

    In this study, a unified model for BeiDou Navigation Satellite System (BDS) wide area and local area augmentation positioning based on raw observations has been proposed. Applying this model, both the Real-Time Kinematic (RTK) and Precise Point Positioning (PPP) service can be realized by performing different corrections at the user end. This algorithm was assessed and validated with the BDS data collected at four regional stations from Day of Year (DOY) 080 to 083 of 2016. When the users are located within the local reference network, the fast and high precision RTK service can be achieved using the regional observation corrections, revealing a convergence time of about several seconds and a precision of about 2-3 cm. For the users out of the regional reference network, the global broadcast State-Space Represented (SSR) corrections can be utilized to realize the global PPP service which shows a convergence time of about 25 min for achieving an accuracy of 10 cm. With this unified model, it can not only integrate the Network RTK (NRTK) and PPP into a seamless positioning service, but also recover the ionosphere Vertical Total Electronic Content (VTEC) and Differential Code Bias (DCB) values that are useful for the ionosphere monitoring and modeling.

  3. Toward Reducing Ageism: PEACE (Positive Education about Aging and Contact Experiences) Model.

    Science.gov (United States)

    Levy, Sheri R

    2016-08-10

    The population of older adults is growing worldwide. Negative ageism (negative attitudes and behavior toward older adults) is a serious international concern that negatively influences not only older adults but also individuals across the age continuum. This article proposes and examines the application of an integrative theoretical model across empirical evidence in the literature on ageism in psychology, medicine, social work, and sociology. The proposed Positive Education about Aging and Contact Experiences (PEACE) model focuses on 2 key contributing factors expected to reduce negative ageism: (a) education about aging including facts on aging along with positive older role models that dispel negative and inaccurate images of older adulthood; and (b) positive contact experiences with older adults that are individualized, provide or promote equal status, are cooperative, involve sharing of personal information, and are sanctioned within the setting. These 2 key contributing factors have the potential to be interconnected and work together to reduce negative stereotypes, aging anxiety, prejudice, and discrimination associated with older adults and aging. This model has implications for policies and programs that can improve the health and well-being of individuals, as well as expand the residential, educational, and career options of individuals across the age continuum.

  4. Multi-Sensor Fusion with Interacting Multiple Model Filter for Improved Aircraft Position Accuracy

    Directory of Open Access Journals (Sweden)

    Changho Lee

    2013-03-01

    Full Text Available The International Civil Aviation Organization (ICAO has decided to adopt Communications, Navigation, and Surveillance/Air Traffic Management (CNS/ATM as the 21st century standard for navigation. Accordingly, ICAO members have provided an impetus to develop related technology and build sufficient infrastructure. For aviation surveillance with CNS/ATM, Ground-Based Augmentation System (GBAS, Automatic Dependent Surveillance-Broadcast (ADS-B, multilateration (MLAT and wide-area multilateration (WAM systems are being established. These sensors can track aircraft positions more accurately than existing radar and can compensate for the blind spots in aircraft surveillance. In this paper, we applied a novel sensor fusion method with Interacting Multiple Model (IMM filter to GBAS, ADS-B, MLAT, and WAM data in order to improve the reliability of the aircraft position. Results of performance analysis show that the position accuracy is improved by the proposed sensor fusion method with the IMM filter.

  5. Existence Results for a Michaud Fractional, Nonlocal, and Randomly Position Structured Fragmentation Model

    Directory of Open Access Journals (Sweden)

    Emile Franc Doungmo Goufo

    2014-01-01

    Full Text Available Until now, classical models of clusters’ fission remain unable to fully explain strange phenomena like the phenomenon of shattering (Ziff and McGrady, 1987 and the sudden appearance of infinitely many particles in some systems having initial finite number of particles. That is why there is a need to extend classical models to models with fractional derivative order and use new and various techniques to analyze them. In this paper, we prove the existence of strongly continuous solution operators for nonlocal fragmentation models with Michaud time derivative of fractional order (Samko et al., 1993. We focus on the case where the splitting rate is dependent on size and position and where new particles generating from fragmentation are distributed in space randomly according to some probability density. In the analysis, we make use of the substochastic semigroup theory, the subordination principle for differential equations of fractional order (Prüss, 1993, Bazhlekova, 2000, the analogy of Hille-Yosida theorem for fractional model (Prüss, 1993, and useful properties of Mittag-Leffler relaxation function (Berberan-Santos, 2005. We are then able to show that the solution operator to the full model is positive and contractive.

  6. Psychometric validation of the consensus five-factor model of the Positive and Negative Syndrome Scale.

    Science.gov (United States)

    Fong, Ted C T; Ho, Rainbow T H; Wan, Adrian H Y; Siu, Pantha Joey C Y; Au-Yeung, Friendly S W

    2015-10-01

    The Positive and Negative Syndrome Scale (PANSS) is widely used for clinical assessment of symptoms in schizophrenia. Instead of the traditional pyramidal model, recent literature supports the pentagonal model for the dimensionality of the PANSS. The present study aimed to validate the consensus five-factor model of the PANSS and evaluate its convergent validity. Participants were 146 Chinese chronic schizophrenic patients who completed diagnostic interviews and cognitive assessments. Exploratory structural equation modeling (ESEM) was performed to investigate the dimensionality of the PANSS. Covariates (age, sex, and education level) and concurrent outcomes (perceived stress, memory, daily living functions, and motor deficits) were added in the ESEM model. The results supported the consensus 5-factor underlying structure, which comprised 20 items categorized into positive, negative, excitement, depression, and cognitive factors with acceptable reliability (α=.69-.85) and strong factor loadings (λ=.41-.93). The five factors, especially the cognitive factor, showed evident convergent validity with the covariates and concurrent outcomes. The results support the consensus five-factor structure of the PANSS as a robust measure of symptoms in schizophrenia. Future studies could explore the clinical and practical utility of the consensus five-factor model. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. The impact of systematically incomplete and positionally inaccurate landslide inventories on statistical landslide susceptibility models

    Science.gov (United States)

    Steger, Stefan; Brenning, Alexander; Bell, Rainer; Glade, Thomas

    2016-04-01

    Several publications emphasize that the quality of statistical landslide susceptibility maps is highly dependent on the completeness and positional accuracy of the landslide inventory used as a response variable to produce the underlying models. We assume that erroneous landslide inventories distort relationships between a landslide inventory and its predictors while we hypothesize that the predictive performance of the underlying models is not necessarily worse in comparison to models generated with an accurate and unbiased landslide inventory. The objective of this study was to investigate the effect of incomplete and positionally inaccurate landslide inventories on the results of statistical landslide susceptibility models. An additional aim was to explore the potential of applying multilevel models to tackle the problem of confounded model coefficients as a results of inventory-based biases. The study was conducted for a landslide-prone study area (100 km²) located in the western part of Lower Austria. An accurate earth-slide point inventory (n = 591) was available for that region. The methodological approach consisted of an artificial introduction of biases and positional inaccuracies into the present landslide inventory and a subsequent quantitative (odds ratios, variable importance, non-spatial and spatial cross validation) and qualitative (geomorphic plausibility) evaluation of the modelling results. Two mapping biases were introduced separately by gradually thinning landslide data (0%, 20%, 80%) within (i) forested areas and (ii) selected municipalities. Positional inaccuracies were simulated by gradually changing the original landslide position (0, 5, 10, 20, 50 and 120 m). The resulting inventories were introduced into a logistic regression model while we considered the effects of including or excluding predictors directly related to the respective incompleteness. All incomplete inventories were additionally introduced into a two-level generalized

  8. An ion species model for positive ion sources - part I description of the model

    CERN Document Server

    Surrey, E

    2014-01-01

    A one dimensional model of the magnetic multipole volume plasma source has been developed for use in intense ion/neutral atom beam injectors. The model uses plasma transport coefficients for particle and energy flow to create a detailed description of the plasma parameters along an axis parallel to that of the extracted beam. Primarily constructed for applications to neutral beam injection systems on fusion devices, the model concentrates on the hydrogenic isotopes but can be extended to any gas by substitution of the relevant masses, cross sections and rate coefficients. The model considers the flow of fast ionizing electrons that create the ratios of the three hydrogenic isotope ion species, H+, H2 +, H3 + (and similarly for deuterium and tritium) as they flow towards the beam extraction electrode, together with the production of negative hydrogenic ions through volume processes. The use of detailed energy balance in the discharge allows the determination of the fraction of the gas density that is in an ato...

  9. Fine-scale modeling of bristlecone pine treeline position in the Great Basin, USA

    Science.gov (United States)

    Bruening, Jamis M.; Tran, Tyler J.; Bunn, Andrew G.; Weiss, Stuart B.; Salzer, Matthew W.

    2017-01-01

    Great Basin bristlecone pine (Pinus longaeva) and foxtail pine (Pinus balfouriana) are valuable paleoclimate resources due to their longevity and climatic sensitivity of their annually-resolved rings. Treeline research has shown that growing season temperatures limit tree growth at and just below the upper treeline. In the Great Basin, the presence of precisely dated remnant wood above modern treeline shows that the treeline ecotone shifts at centennial timescales tracking long-term changes in climate; in some areas during the Holocene climatic optimum treeline was 100 meters higher than at present. Regional treeline position models built exclusively from climate data may identify characteristics specific to Great Basin treelines and inform future physiological studies, providing a measure of climate sensitivity specific to bristlecone and foxtail pine treelines. This study implements a topoclimatic analysis—using topographic variables to explain patterns in surface temperatures across diverse mountainous terrain—to model the treeline position of three semi-arid bristlecone and/or foxtail pine treelines in the Great Basin as a function of growing season length and mean temperature calculated from in situ measurements. Results indicate: (1) the treeline sites used in this study are similar to other treelines globally, and require a growing season length of between 147-153 days and average temperature ranging from 5.5°C-7.2°C, (2) site-specific treeline position models may be improved through topoclimatic analysis and (3) treeline position in the Great Basin is likely out of equilibrium with the current climate, indicating a possible future upslope shift in treeline position.

  10. Yoga and positive body image: A test of the Embodiment Model.

    Science.gov (United States)

    Mahlo, Leeann; Tiggemann, Marika

    2016-09-01

    The study aimed to test the Embodiment Model of Positive Body Image (Menzel & Levine, 2011) within the context of yoga. Participants were 193 yoga practitioners (124 Iyengar, 69 Bikram) and 127 university students (non-yoga participants) from Adelaide, South Australia. Participants completed questionnaire measures of positive body image, embodiment, self-objectification, and desire for thinness. Results showed yoga practitioners scored higher on positive body image and embodiment, and lower on self-objectification than non-yoga participants. In support of the embodiment model, the relationship between yoga participation and positive body image was serially mediated by embodiment and reduced self-objectification. Although Bikram practitioners endorsed appearance-related reasons for participating in yoga more than Iyengar practitioners, there were no significant differences between Iyengar and Bikram yoga practitioners on body image variables. It was concluded that yoga is an embodying activity that can provide women with the opportunity to cultivate a favourable relationship with their body. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. A PID Positioning Controller with a Curve Fitting Model Based on RFID Technology

    Directory of Open Access Journals (Sweden)

    Young-Long Chen

    2013-04-01

    Full Text Available The global positioning system (GPS is an important research topic to solve outdoor positioning problems, but GPS is unable to locate objects accurately and precisely indoors. Some available systems apply ultrasound or optical tracking. This paper presents an efficient proportional-integral-derivative (PID controller with curve fitting model for mobile robot localization and position estimation which adopts passive radio frequency identification (RFID tags in a space. This scheme is based on a mobile robot carries an RFID reader module which reads the installed low-cost passive tags under the floor in a grid-like pattern. The PID controllers increase the efficiency of captured RFID tags and the curve fitting model is used to systematically identify the revolutions per minute (RPM of the motor. We control and monitor the position of the robot from a remote location through a mobile phone via Wi-Fi and Bluetooth network. Experiment results present that the number of captured RFID tags of our proposed scheme outperforms that of the previous scheme.

  12. DPNuc: Identifying Nucleosome Positions Based on the Dirichlet Process Mixture Model.

    Science.gov (United States)

    Chen, Huidong; Guan, Jihong; Zhou, Shuigeng

    2015-01-01

    Nucleosomes and the free linker DNA between them assemble the chromatin. Nucleosome positioning plays an important role in gene transcription regulation, DNA replication and repair, alternative splicing, and so on. With the rapid development of ChIP-seq, it is possible to computationally detect the positions of nucleosomes on chromosomes. However, existing methods cannot provide accurate and detailed information about the detected nucleosomes, especially for the nucleosomes with complex configurations where overlaps and noise exist. Meanwhile, they usually require some prior knowledge of nucleosomes as input, such as the size or the number of the unknown nucleosomes, which may significantly influence the detection results. In this paper, we propose a novel approach DPNuc for identifying nucleosome positions based on the Dirichlet process mixture model. In our method, Markov chain Monte Carlo (MCMC) simulations are employed to determine the mixture model with no need of prior knowledge about nucleosomes. Compared with three existing methods, our approach can provide more detailed information of the detected nucleosomes and can more reasonably reveal the real configurations of the chromosomes; especially, our approach performs better in the complex overlapping situations. By mapping the detected nucleosomes to a synthetic benchmark nucleosome map and two existing benchmark nucleosome maps, it is shown that our approach achieves a better performance in identifying nucleosome positions and gets a higher F-score. Finally, we show that our approach can more reliably detect the size distribution of nucleosomes.

  13. A PID Positioning Controller with a Curve Fitting Model Based on RFID Technology

    Directory of Open Access Journals (Sweden)

    Young-Long Chen

    2013-03-01

    Full Text Available The global positioning system (GPS is an important research topic to solve outdoor positioning problems, but GPSis unable to locate objects accurately and precisely indoors. Some available systems apply ultrasound or opticaltracking. This paper presents an efficient proportional-integral-derivative (PID controller with curve fitting model formobile robot localization and position estimation which adopts passive radio frequency identification (RFID tags ina space. This scheme is based on a mobile robot carries an RFID reader module which reads the installed low-costpassive tags under the floor in a grid-like pattern. The PID controllers increase the efficiency of captured RFID tagsand the curve fitting model is used to systematically identify the revolutions per minute (RPM of the motor. Wecontrol and monitor the position of the robot from a remote location through a mobile phone via Wi-Fi and Bluetoothnetwork. Experiment results present that the number of captured RFID tags of our proposed scheme outperformsthat of the previous scheme.

  14. Model-independent analysis of the Fermilab Tevatron turn-by-turn beam position monitor measurements

    Energy Technology Data Exchange (ETDEWEB)

    Petrenko, A.V.; /Novosibirsk, IYF; Valishev, A.A.; Lebedev, V.A.; /Fermilab

    2011-09-01

    Coherent transverse beam oscillations in the Tevatron were analyzed with the model-independent analysis (MIA) technique. This allowed one to obtain the model-independent values of coupled betatron amplitudes, phase advances, and dispersion function around the ring from a single dipole kick measurement. In order to solve the MIA mode mixing problem which limits the accuracy of determination of the optical functions, we have developed a new technique of rotational MIA mode untangling. The basic idea is to treat each beam position monitor (BPM) as two BPMs separated in a ring by exactly one turn. This leads to a simple criterion of MIA mode separation: the betatron phase advance between any BPM and its counterpart shifted by one turn should be equal to the betatron tune and therefore should not depend on the BPM position in the ring. Furthermore, we describe a MIA-based technique to locate vibrating magnets in a storage ring.

  15. Model-independent analysis of the Fermilab Tevatron turn-by-turn beam position monitor measurements

    Energy Technology Data Exchange (ETDEWEB)

    Petrenko, A.V.; /Novosibirsk, IYF; Valishev, A.A.; Lebedev, V.A.; /Fermilab

    2011-09-01

    Coherent transverse beam oscillations in the Tevatron were analyzed with the model-independent analysis (MIA) technique. This allowed one to obtain the model-independent values of coupled betatron amplitudes, phase advances, and dispersion function around the ring from a single dipole kick measurement. In order to solve the MIA mode mixing problem which limits the accuracy of determination of the optical functions, we have developed a new technique of rotational MIA mode untangling. The basic idea is to treat each beam position monitor (BPM) as two BPMs separated in a ring by exactly one turn. This leads to a simple criterion of MIA mode separation: the betatron phase advance between any BPM and its counterpart shifted by one turn should be equal to the betatron tune and therefore should not depend on the BPM position in the ring. Furthermore, we describe a MIA-based technique to locate vibrating magnets in a storage ring.

  16. A computationally efficient approach for hidden-Markov model-augmented fingerprint-based positioning

    Science.gov (United States)

    Roth, John; Tummala, Murali; McEachen, John

    2016-09-01

    This paper presents a computationally efficient approach for mobile subscriber position estimation in wireless networks. A method of data scaling assisted by timing adjust is introduced in fingerprint-based location estimation under a framework which allows for minimising computational cost. The proposed method maintains a comparable level of accuracy to the traditional case where no data scaling is used and is evaluated in a simulated environment under varying channel conditions. The proposed scheme is studied when it is augmented by a hidden-Markov model to match the internal parameters to the channel conditions that present, thus minimising computational cost while maximising accuracy. Furthermore, the timing adjust quantity, available in modern wireless signalling messages, is shown to be able to further reduce computational cost and increase accuracy when available. The results may be seen as a significant step towards integrating advanced position-based modelling with power-sensitive mobile devices.

  17. Positive Psychological Interventions for Patients with Type 2 Diabetes: Rationale, Theoretical Model, and Intervention Development

    Directory of Open Access Journals (Sweden)

    Jeff C. Huffman

    2015-01-01

    Full Text Available Most patients with type 2 diabetes (T2D have suboptimal adherence to recommended diet, physical activity, and/or medication. Current approaches to improve health behaviors in T2D have been variably effective, and successful interventions are often complex and intensive. It is therefore vital to develop interventions that are simple, well-accepted, and applicable to a wide range of patients who suffer from T2D. One approach may be to boost positive psychological states, such as positive affect or optimism, as these constructs have been prospectively and independently linked to improvements in health behaviors. Positive psychology (PP interventions, which utilize systematic exercises to increase optimism, well-being, and positive affect, consistently increase positive states and are easily delivered to patients with chronic illnesses. However, to our knowledge, PP interventions have not been formally tested in T2D. In this paper, we review a theoretical model for the use of PP interventions to target health behaviors in T2D, describe the structure and content of a PP intervention for T2D patients, and describe baseline data from a single-arm proof-of-concept (N=15 intervention study in T2D patients with or without depression. We also discuss how PP interventions could be combined with motivational interviewing (MI interventions to provide a blended psychological-behavioral approach.

  18. ANTITUMOR EFFECT OF SARCNU IN A 06-METHYLGUANINE-DNA METHYLTRANSFERASE POSITIVE HUMAN GLIOMA XENOGRAFT MODEL

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    To assess whether novel analogue of nitrosoureas, 2-chloroethyl-3-sarcosinamide-1-nitrosourea (SarCNU), has antitumor effect to 06-methylguanine-DNA methyltransferase (MGMT) positive tumors in vivo. Methods: MGMT positive human glioma cell line SF-767 xenografts in nude mice were treated with SarCNU. The antitumor efficacy of SarCNU was compared with the results of 1, 3-bis(2-chloroethyl)-1-nitrosourea (BCNU) treatment with or without 06-benzylguanine (06-BG) preadministration. Results: Since the SF-767 is MGMT strongly positive, BCNU treatment alone did not result in a satisfactory anticancer effect. As expected, 06-BG by depleting MGMT activity, significantly enhanced BCNU antitumor efficacy (p<0.001). More interestingly, SarCNU treatment alone had a better antitumor effect than 06-BG plus BCNU treatment (F=51.7, p=0.00036). Conclusion: Since SarCNU enters cells via extraneuronal monoamine transporter (EMT), the enhanced antitumor activity of SarCNU in this MGMT positive human tumor xenograft model may be due to the presence of EMT in SF-767.SarCNU may be used as an alternative treatment for MGMT positive tumors, specifically for tumors expressing EMT.

  19. Position of aggressiveness in common latent space of PEN model and model Big Five Plus Two

    Directory of Open Access Journals (Sweden)

    Dinić Bojana

    2012-01-01

    Full Text Available The purpose of this research was to examine the relations between different aspects of aggressiveness and personality traits. Buss-Perry Aggression Questionnaire (AQ, Eysenck Personality Questionnaire (EPQ, which represent psychobiological model, and inventory Big Five Plus Two Inventory (BF+2, which represent psycholexical model of personality in Serbian language, were administered to 478 participants. The results revealed that affective impulsive aggressiveness and predatory or instrumental aggressiveness could be identified in the aggressiveness - personality traits relationships. Those aspects of aggressiveness could take manifest or latent character. As expected, Psychoticism from EPQ, Aggressiveness, and Negative Valence from BF+2 showed a significant contribution to all identified forms, except for Aggressiveness in relations with “acting out” physical aggression. Although these personality traits carry out significant loadings, these loadings were not always the highest. Affective-impulsive aggressiveness, which was mainly determined by the components of latent domain AQ, was related to Neuroticism from both models. The remaining forms of manifest aggressiveness were related to low Consciousness, whereas Physical aggression is connected to Extraversion and Oppennes. This connection represents possible “acting out” reaction or more frequent tendency of impulsive physical aggression. The results showed that aggressiveness represents a multidimensional construct which could be explained by specific constellation of personality traits, depending which aspects of aggressivenes are of interest. [Projekat Ministarstva nauke Republike Srbije, br. ON179006: Nasledni, sredinski i psihološki činioci mentalnog zdravlja

  20. An efficient positive potential-density pair expansion for modelling galaxies

    Science.gov (United States)

    Rojas-Niño, A.; Read, J. I.; Aguilar, L.; Delorme, M.

    2016-07-01

    We present a novel positive potential-density pair expansion for modelling galaxies, based on the Miyamoto-Nagai disc. By using three sets of such discs, each one of them aligned along each symmetry axis, we are able to reconstruct a broad range of potentials that correspond to density profiles from exponential discs to 3D power-law models with varying triaxiality (henceforth simply `twisted' models). We increase the efficiency of our expansion by allowing the scalelength parameter of each disc to be negative. We show that, for suitable priors on the scalelength and scaleheight parameters, these `MNn discs' (Miyamoto-Nagai negative) have just one negative density minimum. This allows us to ensure global positivity by demanding that the total density at the global minimum is positive. We find that at better than 10 per cent accuracy in our density reconstruction, we can represent a radial and vertical exponential disc over 0.1-10 scalelengths/scaleheights with four MNn discs; a Navarro, Frenk and White (NFW) profile over 0.1-10 scalelengths with four MNn discs; and a twisted triaxial NFW profile with three MNn discs per symmetry axis. Our expansion is efficient, fully analytic, and well suited to reproducing the density distribution and gravitational potential of galaxies from discs to ellipsoids.

  1. An efficient positive potential-density pair expansion for modelling galaxies

    CERN Document Server

    Rojas-Niño, Armando; Aguilar, Luis; Delorme, Maxime

    2016-01-01

    We present a novel positive potential-density pair expansion for modelling galaxies, based on the Miyamoto-Nagai (MN) disc. By using three sets of such discs, each one of them aligned along each symmetry axis, we are able to reconstruct a broad range of potentials that correspond to density profiles from exponential discs to 3D power law models with varying triaxiality (henceforth simply "twisted" models). We increase the efficiency of our expansion by allowing the scale length parameter of each disc to be negative. We show that, for suitable priors on the scale length and height parameters, these "MNn discs" have just one negative density minimum. This allows us to ensure global positivity by demanding that the total density at the global minimum is positive. We find that at better than 10\\% accuracy in our density reconstruction, we can represent a radial and vertical exponential disc over $0.1-10$ scale lengths/heights with 4 MNn discs, an NFW profile over $0.1-10$ scale lengths with 4 MNn discs, and a twi...

  2. A structural equation model to evaluate direct and indirect factors associated with a latent measure of mastitis in Belgian dairy herds.

    Science.gov (United States)

    Detilleux, J; Theron, L; Beduin, J-M; Hanzen, C

    2012-12-01

    In dairy cattle, many farming practices have been associated with occurrence of mastitis but it is often difficult to disentangle the causal threads. Structural equation models may reduce the complexity of such situations. Here, we applied the method to examine the links between mastitis (subclinical and clinical) and risk factors such as herd demographics, housing conditions, feeding procedures, milking practices, and strategies of mastitis prevention and treatment in 345 dairy herds from the Walloon region of Belgium. During the period January 2006 to October 2007, up to 110 different herd management variables were recorded by two surveyors using a questionnaire for the farm managers and during a farm visit. Monthly somatic cell counts of all lactating cows were collected by the local dairy herd improvement association. Structural equation models were created to obtain a latent measure of mastitis and to reduce the complexity of the relationships between farming practices, between indicators of herd mastitis and between both. Robust maximum likelihood estimates were obtained for the effects of the herd management variables on the latent measure of herd mastitis. Variables associated directly (pteat disinfection; the presence of cows with hyperkeratotic teats, of cubicles for housing and of dirty liners before milking; the treatment of subclinical cases of mastitis; and the age of the herd (latent variable for average age and parity of cows, and percentage of heifers in the herd). Treatment of subclinical mastitis was also an intermediate in the association between herd mastitis and post-milking teat disinfection. The study illustrates how structural equation model provides information regarding the linear relationships between risk factors and a latent measure of mastitis, distinguishes between direct relationships and relationships mediated through intermediate risk factors, allows the construction of latent variables and tests the directional hypotheses

  3. Using the Correlation Criterion to Position and Shape RBF Units for Incremental Modelling

    Institute of Scientific and Technical Information of China (English)

    Xun-Xian Wang; Sheng Chen; Chris J. Harris

    2006-01-01

    A novel technique is proposed for the incremental construction of sparse radial basis function (RBF) networks.The correlation between an RBF regressor and the training data is used as the criterion to position and shape the RBF node, and it is shown that this is equivalent to incrementally minimise the modelling mean square error. A guided random search optimisation method, called the repeated weighted boosting search, is adopted to append RBF nodes one by one in an incremental regression modelling procedure. The experimental results obtained using the proposed method demonstrate that it provides a viable alternative to the existing state-of-the-art modelling techniques for constructing parsimonious RBF models that generalise well.

  4. Positivity of Lyapunov exponents for Anderson-type models on two coupled strings

    Directory of Open Access Journals (Sweden)

    Hakim Boumaza

    2007-03-01

    Full Text Available We study two models of Anderson-type random operators on two deterministically coupled continuous strings. Each model is associated with independent, identically distributed four-by-four symplectic transfer matrices, which describe the asymptotics of solutions. In each case we use a criterion by Gol'dsheid and Margulis (i.e. Zariski denseness of the group generated by the transfer matrices in the group of symplectic matrices to prove positivity of both leading Lyapunov exponents for most energies. In each case this implies almost sure absence of absolutely continuous spectrum (at all energies in the first model and for sufficiently large energies in the second model. The methods used allow for singularly distributed random parameters, including Bernoulli distributions.

  5. Research on temperature control with numerical regulators in electric resistance furnaces with indirect heating

    Science.gov (United States)

    Diniş, C. M.; Popa, G. N.; Iagăr, A.

    2016-02-01

    The paper is an analysis of two-positions (hysteresis) regulators, self-tuned PID controller and PID controller for temperature control used for indirect heat resistance furnaces. For PID controller was used three methods of tuning: Ziegler-Nichols step response model, Cohen-Coon tuning rules and Ziegler-Nichols tuning rules. In experiments it used an electric furnace with indirect heating with active power of resistance of 1 kW/230V AC and a numerical temperature regulator AT-503 type (ANLY). It got a much better temperature control when using the Cohen-Coon tuning rules method than those of Ziegler-Nichols step response method and Ziegler-Nichols tuning rules method.

  6. Indirect Medical Education and Disproportionate Share Adj...

    Data.gov (United States)

    U.S. Department of Health & Human Services — Indirect Medical Education and Disproportionate Share Adjustments to Medicare Inpatient Payment Rates The indirect medical education (IME) and disproportionate share...

  7. Indirect Medical Education and Disproportionate Share Adj...

    Data.gov (United States)

    U.S. Department of Health & Human Services — Indirect Medical Education and Disproportionate Share Adjustments to Medicare Inpatient Payment Rates The indirect medical education (IME) and disproportionate share...

  8. Indirect searches for dark matter

    Indian Academy of Sciences (India)

    Marco Cirelli

    2012-11-01

    The current status of indirect searches for dark matter has been reviewed in a schematic way here. The main relevant experimental results of the recent years have been listed and the excitements and disappointments that their phenomenological interpretations in terms of almost-standard annihilating dark matter have brought along have been discussed. The main sources of uncertainties that affect this kind of searches are also listed. [Report number: Saclay T11/206, CERN-PH-TH/2011-257, extended version in arXiv:1202.1454], [Prepared for the Proceedings of Lepton–Photon 2011, Mumbai, India, 22–27 Aug. 2011].

  9. Spine alignment in men during lateral sleep position: experimental study and modeling

    Directory of Open Access Journals (Sweden)

    Leilnahari Karim

    2011-11-01

    Full Text Available Abstract Background A proper sleep system can affect the spine support in neutral position. Most of the previous studies in scientific literature have focused on the effects of customary mattresses on the spinal alignment. To keep the spine in optimal alignment, one can use sleep surfaces with different zonal elasticity, the so called custom-made arrangements. The required stiffness of a sleep surface for each individual can be obtained by changing this arrangement applying the experimental method and modeling. Methods In experimental part, the coordinate positions of the markers mounted on the spinous processes of the vertebrae of 25 male volunteers were registered in frontal plane through the optical tracking method and so the spinal alignment was obtained in lateral sleep position on soft and firm surfaces and on the best custom-made arrangement. Thereupon the π-P8 angles were extracted from these alignments and then were compared with each other. In modeling part the anthropometric data of four different types of volunteers were used. And then the models built in BRG.LifeMOD (ver. 2007, Biomechanics Research Group, Inc., USA based on these data and in accordance with the experimental tests, were analyzed. Results The one way ANOVA statistical model and the post hoc tests showed a significant difference in the π-P8 angles between soft & custom-made and soft & firm mattresses at the p = 0.001 level and between firm & soft mattresses at the p = 0.05 level. In modeling part, the required stiffness of the sleep surface for four weight-dimensional groups was acquired quantitatively. Conclusions The mattress with a custom-made arrangement is a more appropriate choice for heavier men with pronounced body contour. After data fitting, it was observed that the variations of spinal alignment obtained from both methods have the same trend. Observing the amount of required stiffness obtained for the sleep surface, can have a significant effect on

  10. Indirect field technology for detecting areas object of illegal spills harmful to human health: application of drones, photogrammetry and hydrological models

    Directory of Open Access Journals (Sweden)

    Alessandra Capolupo

    2014-12-01

    Full Text Available The accumulation of heavy metals in agricultural soils is a serious environmental problem. The Campania region in southern Italy has higher levels of cancer risk, presumably due to the accumulation of geogenic and anthropogenic soil pollutants, some of which have been incorporated into organic matter. The aim of this study was to introduce and test an innovative, field-applicable methodology to detect heavy metal accumulation using drone-based photogrammetry and microrill network modelling, specifically to generate wetlands wetlands prediction indices normally applied at large catchment scales, such as a large geographic basin. The processing of aerial photos taken using a hexacopter equipped with fifth-generation software for photogrammetry allowed the generation of a digital elevation model (DEM with a resolution as high as 30 mm. Not only this provided a high potential for the study of micro-rill processes, but it was also useful for testing and comparing the capability of the topographic index (TI and the clima-topographic index (CTI to predict heavy metal sedimentation points at scales from 0.1 to 10 ha. Our results indicate that the TI and CTI indices can be used to predict points of heavy metal accumulation for small field catchments.

  11. Indirect field technology for detecting areas object of illegal spills harmful to human health: application of drones, photogrammetry and hydrological models.

    Science.gov (United States)

    Capolupo, Alessandra; Pindozzi, Stefania; Okello, Collins; Boccia, Lorenzo

    2014-12-01

    The accumulation of heavy metals in agricultural soils is a serious environmental problem. The Campania region in southern Italy has higher levels of cancer risk, presumably due to the accumulation of geogenic and anthropogenic soil pollutants, some of which have been incorporated into organic matter. The aim of this study was to introduce and test an innovative, field-applicable methodology to detect heavy metal accumulation using drone-based photogrammetry and microrill network modelling, specifically to generate wetlands wetlands prediction indices normally applied at large catchment scales, such as a large geographic basin. The processing of aerial photos taken using a hexacopter equipped with fifth-generation software for photogrammetry allowed the generation of a digital elevation model (DEM) with a resolution as high as 30 mm. Not only this provided a high potential for the study of micro-rill processes, but it was also useful for testing and comparing the capability of the topographic index (TI) and the clima-topographic index (CTI) to predict heavy metal sedimentation points at scales from 0.1 to 10 ha. Our results indicate that the TI and CTI indices can be used to predict points of heavy metal accumulation for small field catchments.

  12. Direct and indirect alcohol biomarkers data collected in hair samples - multivariate data analysis and likelihood ratio interpretation perspectives

    Directory of Open Access Journals (Sweden)

    Eugenio Alladio

    2017-06-01

    Full Text Available The concentration values of direct and indirect biomarkers of ethanol consumption were detected in blood (indirect or hair (direct samples from a pool of 125 individuals classified as either chronic (i.e. positive and non-chronic (i.e. negative alcohol drinkers. These experimental values formed the dataset under examination (Table 1. Indirect biomarkers included: aspartate transferase (AST, alanine transferase (ALT, gamma-glutamyl transferase (GGT, mean corpuscular volume of the erythrocytes (MCV, carbohydrate-deficient-transferrin (CDT. The following direct biomarkers were also detected in hair: ethyl myristate (E14:0, ethyl palmitate (E16:0, ethyl stearate (E18:1, ethyl oleate (E18:0, the sum of their four concentrations (FAEEs, i.e. Fatty Acid Ethyl Esters and ethyl glucuronide (EtG; pg/mg. Body mass index (BMI was also collected as a potential influencing factor. Likelihood ratio (LR approaches have been used to provide predictive models for the diagnosis of alcohol abuse, based on different combinations of direct and indirect alcohol biomarkers, as described in “Evaluation of direct and indirect ethanol biomarkers using a likelihood ratio approach to identify chronic alcohol abusers for forensic purposes” (E. Alladio, A. Martyna, A. Salomone, V. Pirro, M. Vincenti, G. Zadora, 2017 [1].

  13. Toward an Optimal Position for IVC Filters: Computational Modeling of the Impact of Renal Vein Inflow

    Energy Technology Data Exchange (ETDEWEB)

    Wang, S L; Singer, M A

    2009-07-13

    The purpose of this report is to evaluate the hemodynamic effects of renal vein inflow and filter position on unoccluded and partially occluded IVC filters using three-dimensional computational fluid dynamics. Three-dimensional models of the TrapEase and Gunther Celect IVC filters, spherical thrombi, and an IVC with renal veins were constructed. Hemodynamics of steady-state flow was examined for unoccluded and partially occluded TrapEase and Gunther Celect IVC filters in varying proximity to the renal veins. Flow past the unoccluded filters demonstrated minimal disruption. Natural regions of stagnant/recirculating flow in the IVC are observed superior to the bilateral renal vein inflows, and high flow velocities and elevated shear stresses are observed in the vicinity of renal inflow. Spherical thrombi induce stagnant and/or recirculating flow downstream of the thrombus. Placement of the TrapEase filter in the suprarenal vein position resulted in a large area of low shear stress/stagnant flow within the filter just downstream of thrombus trapped in the upstream trapping position. Filter position with respect to renal vein inflow influences the hemodynamics of filter trapping. Placement of the TrapEase filter in a suprarenal location may be thrombogenic with redundant areas of stagnant/recirculating flow and low shear stress along the caval wall due to the upstream trapping position and the naturally occurring region of stagnant flow from the renal veins. Infrarenal vein placement of IVC filters in a near juxtarenal position with the downstream cone near the renal vein inflow likely confers increased levels of mechanical lysis of trapped thrombi due to increased shear stress from renal vein inflow.

  14. Modeling the probability distribution of positional errors incurred by residential address geocoding

    Directory of Open Access Journals (Sweden)

    Mazumdar Soumya

    2007-01-01

    Full Text Available Abstract Background The assignment of a point-level geocode to subjects' residences is an important data assimilation component of many geographic public health studies. Often, these assignments are made by a method known as automated geocoding, which attempts to match each subject's address to an address-ranged street segment georeferenced within a streetline database and then interpolate the position of the address along that segment. Unfortunately, this process results in positional errors. Our study sought to model the probability distribution of positional errors associated with automated geocoding and E911 geocoding. Results Positional errors were determined for 1423 rural addresses in Carroll County, Iowa as the vector difference between each 100%-matched automated geocode and its true location as determined by orthophoto and parcel information. Errors were also determined for 1449 60%-matched geocodes and 2354 E911 geocodes. Huge (> 15 km outliers occurred among the 60%-matched geocoding errors; outliers occurred for the other two types of geocoding errors also but were much smaller. E911 geocoding was more accurate (median error length = 44 m than 100%-matched automated geocoding (median error length = 168 m. The empirical distributions of positional errors associated with 100%-matched automated geocoding and E911 geocoding exhibited a distinctive Greek-cross shape and had many other interesting features that were not capable of being fitted adequately by a single bivariate normal or t distribution. However, mixtures of t distributions with two or three components fit the errors very well. Conclusion Mixtures of bivariate t distributions with few components appear to be flexible enough to fit many positional error datasets associated with geocoding, yet parsimonious enough to be feasible for nascent applications of measurement-error methodology to spatial epidemiology.

  15. Tropospheric delay parameters from numerical weather models for multi-GNSS precise positioning

    Science.gov (United States)

    Lu, Cuixian; Zus, Florian; Ge, Maorong; Heinkelmann, Robert; Dick, Galina; Wickert, Jens; Schuh, Harald

    2016-12-01

    The recent dramatic development of multi-GNSS (Global Navigation Satellite System) constellations brings great opportunities and potential for more enhanced precise positioning, navigation, timing, and other applications. Significant improvement on positioning accuracy, reliability, as well as convergence time with the multi-GNSS fusion can be observed in comparison with the single-system processing like GPS (Global Positioning System). In this study, we develop a numerical weather model (NWM)-constrained precise point positioning (PPP) processing system to improve the multi-GNSS precise positioning. Tropospheric delay parameters which are derived from the European Centre for Medium-Range Weather Forecasts (ECMWF) analysis are applied to the multi-GNSS PPP, a combination of four systems: GPS, GLONASS, Galileo, and BeiDou. Observations from stations of the IGS (International GNSS Service) Multi-GNSS Experiments (MGEX) network are processed, with both the standard multi-GNSS PPP and the developed NWM-constrained multi-GNSS PPP processing. The high quality and accuracy of the tropospheric delay parameters derived from ECMWF are demonstrated through comparison and validation with the IGS final tropospheric delay products. Compared to the standard PPP solution, the convergence time is shortened by 20.0, 32.0, and 25.0 % for the north, east, and vertical components, respectively, with the NWM-constrained PPP solution. The positioning accuracy also benefits from the NWM-constrained PPP solution, which was improved by 2.5, 12.1, and 18.7 % for the north, east, and vertical components, respectively.

  16. 19 CFR 10.460 - Indirect materials.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Indirect materials. 10.460 Section 10.460 Customs... of Origin § 10.460 Indirect materials. An indirect material, as defined in § 10.402(o), will be considered to be an originating material without regard to where it is produced. Example. Chilean Producer C...

  17. 19 CFR 10.603 - Indirect materials.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Indirect materials. 10.603 Section 10.603 Customs... States Free Trade Agreement Rules of Origin § 10.603 Indirect materials. An indirect material, as defined in § 10.582(m) of this subpart, will be considered to be an originating material without regard to...

  18. 19 CFR 10.541 - Indirect materials.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Indirect materials. 10.541 Section 10.541 Customs... Rules of Origin § 10.541 Indirect materials. An indirect material, as defined in § 10.502(j) of this subpart, will be considered to be an originating material without regard to where it is produced, and its...

  19. Indirect Calorimetry in Mechanically Ventilated Patients

    DEFF Research Database (Denmark)

    Allingstrup, Matilde Jo; Kondrup, Jens; Perner, Anders

    2017-01-01

    BACKGROUND AND AIMS: The 2 currently available indirect calorimeters, CCM Express Indirect Calorimeter (MedGraphics, St Paul, MN) and Quark RMR ICU Indirect Calorimeter (COSMED, Rome, Italy), have not been validated against a gold standard in mechanically ventilated patients. Our aim was to do so...

  20. 46 CFR 154.1720 - Indirect refrigeration.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Indirect refrigeration. 154.1720 Section 154.1720... § 154.1720 Indirect refrigeration. A refrigeration system that is used to cool acetaldehyde, ethylene oxide, or methyl bromide, must be an indirect refrigeration system that does not use vapor compression....

  1. Modeling the Controls on the Front Position of a Tidewater Glacier in Svalbard

    Directory of Open Access Journals (Sweden)

    Jaime Otero

    2017-04-01

    Full Text Available Calving is an important mass-loss process at ice sheet and marine-terminating glacier margins, but identifying and quantifying its principal driving mechanisms remains challenging. Hansbreen is a grounded tidewater glacier in southern Spitsbergen, Svalbard, with a rich history of field and remote sensing observations. The available data make this glacier suitable for evaluating mechanisms and controls on calving, some of which are considered in this paper. We use a full-Stokes thermomechanical 2D flow model (Elmer/Ice, paired with a crevasse-depth calving criterion, to estimate Hansbreen's front position at a weekly time resolution. The basal sliding coefficient is re-calibrated every 4 weeks by solving an inverse model. We investigate the possible role of backpressure at the front (a function of ice mélange concentration and the depth of water filling crevasses by examining the model's ability to reproduce the observed seasonal cycles of terminus advance and retreat. Our results suggest that the ice-mélange pressure plays an important role in the seasonal advance and retreat of the ice front, and that the crevasse-depth calving criterion, when driven by modeled surface meltwater, closely replicates observed variations in terminus position. These results suggest that tidewater glacier behavior is influenced by both oceanic and atmospheric processes, and that neither of them should be ignored.

  2. Position Sensorless Control of IPMSMs Based on a Novel Flux Model Suitable for Maximum Torque Control

    Science.gov (United States)

    Matsumoto, Atsushi; Hasegawa, Masaru; Matsui, Keiju

    In this paper, a novel position sensorless control method for interior permanent magnet synchronous motors (IPMSMs) that is based on a novel flux model suitable for maximum torque control has been proposed. Maximum torque per ampere (MTPA) control is often utilized for driving IPMSMs with the maximum efficiency. In order to implement this control, generally, the parameters are required to be accurate. However, the inductance varies dramatically because of magnetic saturation, which has been one of the most important problems in recent years. Therefore, the conventional MTPA control method fails to achieve maximum efficiency for IPMSMs because of parameter mismatches. In this paper, first, a novel flux model has been proposed for realizing the position sensorless control of IPMSMs, which is insensitive to Lq. In addition, in this paper, it has been shown that the proposed flux model can approximately estimate the maximum torque control (MTC) frame, which as a new coordinate aligned with the current vector for MTPA control. Next, in this paper, a precise estimation method for the MTC frame has been proposed. By this method, highly accurate maximum torque control can be achieved. A decoupling control algorithm based on the proposed model has also been addressed in this paper. Finally, some experimental results demonstrate the feasibility and effectiveness of the proposed method.

  3. Data-model synthesis of grassland carbon metabolism. Quantifying direct, indirect & interactive effects of warming & elevated CO2

    Energy Technology Data Exchange (ETDEWEB)

    Pendall, Elise [Univ. of Wyoming, Laramie, WY (United States); Ogle, Kiona [Univ. of Wyoming, Laramie, WY (United States); Parton, William [Univ. of Wyoming, Laramie, WY (United States)

    2016-02-29

    This research project improved understanding of how climate change (elevated atmospheric CO2, warming and altered precipitation) can affect grassland ecosystem productivity and nutrient availability. Our advanced experimental and modeling methods allowed us to test 21 specific hypotheses. We found that ecosystem changes over years of exposure to climate change can shift the plant communities and potentially make them more resilient to future climate changes. These changes in plant communities may be related to increased growth of belowground roots and enhanced nutrient uptake by some species. We also found that climate change can increase the spread of invasive and noxious weeds. These findings are important for land managers to make adaptive planning decisions for domestic livestock production in response to climate variability in semi-arid grasslands.

  4. Modeling and assessment of triple-frequency BDS precise point positioning

    Science.gov (United States)

    Guo, Fei; Zhang, Xiaohong; Wang, Jinling; Ren, Xiaodong

    2016-11-01

    The latest generation of GNSS satellites such as GPS BLOCK-IIF, Galileo and BDS are transmitting signals on three or more frequencies, thus having more choices in practice. At the same time, new challenges arise for integrating the new signals. This paper contributes to the modeling and assessment of triple-frequency PPP with BDS data. First, three triple-frequency PPP models are developed. The observation model and stochastic model are designed and extended to accommodate the third frequency. In particular, new biases such as differential code biases and inter-frequency biases as well as the parameterizations are addressed. Then, the relationships between different PPP models are discussed. To verify the triple-frequency PPP models, PPP tests with real triple-frequency data were performed in both static and kinematic scenarios. Results show that the three triple-frequency PPP models agree well with each other. Additional frequency has a marginal effect on the positioning accuracy in static PPP tests. However, the benefits of third frequency are significant in situations of where there is poor tracking and contaminated observations on frequencies B1 and B2 in kinematic PPP tests.

  5. Global gravity field models from the GPS positions of CHAMP, GRACE and GOCE satellites

    Science.gov (United States)

    Bezděk, A.; Sebera, J.; Klokočník, J.; Kostelecký, J.

    2012-04-01

    The aim of our work is to generate Earth's gravity field models from the GPS positions of low Earth orbiters. We will present our inversion method and numerical results based on the real-world data of CHAMP, GRACE and GOCE satellites. The presented inversion method is based on Newton's second law of motion, which relates the observed acceleration of the satellite with the forces acting on it. The vector of the observed acceleration is obtained through a numerical second-derivative filter applied to the time series of the kinematic positions. Forces other than those due to the geopotential are either modelled (lunisolar perturbations, tides) or provided by the onboard measurements (nongravitational perturbations). Then the observation equations are formulated using the gradient of the spherical harmonic expansion of the geopotential. From this linear system the harmonic coefficients are directly obtained. We do not use any a priori gravity field model. Although the basic scheme of the acceleration approach is straightforward, the implementation details play a crucial role in obtaining reasonable results. The numerical derivative of noisy data (here the GPS positions) strongly amplifies the high frequency noise and creates autocorrelation in the observation errors. We successfully solve both of these problems by using the generalized least squares method, which defines a linear transformation of the observation equations. In the transformed variables the errors become uncorrelated, so the ordinary least squares estimation may be used to find the regression parameters with correct estimates of their uncertainties. The digital filter of the second derivative is an approximation to the analytical operation. We will show how different the results might be depending on the particular choice of the parameters defining the filter. Another problem is the correlation of the errors in the GPS positions. Here we use the tools from time series analysis. The systematic behaviour

  6. Indirect costs of rheumatoid arthritis.

    Science.gov (United States)

    Raciborski, Filip; Kłak, Anna; Kwiatkowska, Brygida

    2015-01-01

    It is estimated that in Poland about 400,000 persons in general suffer from inflammatory joint diseases, including rheumatoid arthritis (RA). Epidemiological surveys documenting the frequency and disturbance of musculoskeletal disorders in the Polish population are few in number. Most of the estimations are based on epidemiological data from other countries (prevalence of 0.5-1%). According to the data of the National Health Fund in Poland 135,000-157,000 persons in total are treated because of rheumatoid arthritis per year [ICD10 (International Statistical Classification of Diseases and Related Health Problems): M05, M06]. In the case of this group of diseases indirect costs significantly outweigh the direct costs. Indirect costs increase together with activity level of the disease. The cost analysis of productivity loss of RA patients indicates that sickness absenteeism and informal care are the most burdensome. At the national level it amounts in total from 1.2 billion to 2.8 billion PLN per year, depending on the method of analysis. These costs could be significantly reduced through early diagnosis and introduction of effective treatment.

  7. Direct and indirect detection of supersymmetric dark matter; Detection directe et indirecte de matiere sombre supersymetrique

    Energy Technology Data Exchange (ETDEWEB)

    Mayet, F

    2001-09-01

    A substantial body of astrophysical evidence supports the existence of non-baryonic dark matter in the universe. One of the leading dark matter candidates is the neutralino predicted by the supersymmetric extensions of the standard model of particle physics. Different detectors have been designed for the detection, either indirect or direct, of the neutralino. Related to indirect detection, the present work has been performed in the context of the AMS experiment. A precursor version of the spectrometer was flown on the space shuttle Discovery in June 1998. The detector included an Aerogel Threshold Cherenkov counter (ATC) to identify antiprotons, whose spectrum may be used to infer a neutralino signal. The analysis of the ATC data is presented including an evaluation of the flight performance and a description of the optimization of the antiproton selection. An antiproton analysis is also reported. A phenomenological study allows us to investigate the discovery potential of this indirect method. This thesis also includes the development of a new detector (MACHe3) designed for direct neutralino search using a superfluid {sup 3}He bolometer operated at ultra low temperatures. The data analysis of the prototype cell is presented. A Monte Carlo simulation has been developed, in order to optimize the detector design for direct neutralino search. These results are compared with theoretical predictions of supersymmetric models, thus highlighting the discovery potential of this detector and its complementarity with existing devices. (author)

  8. Predicting body appreciation in young women: An integrated model of positive body image.

    Science.gov (United States)

    Andrew, Rachel; Tiggemann, Marika; Clark, Levina

    2016-09-01

    This study examined a range of predictors, based on previous theoretical models, of positive body image in young adult women. Participants were 266 women who completed an online questionnaire measuring body appreciation, activity participation, media consumption, perceived body acceptance by others, self-compassion, and autonomy. Potential mechanisms in predicting body appreciation assessed were self-objectification, social appearance comparison, and thin-ideal internalisation. Results indicated that greater perceived body acceptance by others and self-compassion, and lower appearance media consumption, self-objectification, social comparison, and thin-ideal internalisation were related to greater body appreciation. An integrated model showed that appearance media (negatively) and non-appearance media and self-compassion (positively) were associated with lower self-objectification, social comparison, and thin-ideal internalisation, which in turn related to greater body appreciation. Additionally, perceived body acceptance by others was directly associated with body appreciation. The results contribute to an understanding of potential pathways of positive body image development, thereby highlighting possible intervention targets.

  9. Probability modeling of the number of positive cores in a prostate cancer biopsy session, with applications.

    Science.gov (United States)

    Serfling, Robert; Ogola, Gerald

    2016-02-10

    Among men, prostate cancer (CaP) is the most common newly diagnosed cancer and the second leading cause of death from cancer. A major issue of very large scale is avoiding both over-treatment and under-treatment of CaP cases. The central challenge is deciding clinical significance or insignificance when the CaP biopsy results are positive but only marginally so. A related concern is deciding how to increase the number of biopsy cores for larger prostates. As a foundation for improved choice of number of cores and improved interpretation of biopsy results, we develop a probability model for the number of positive cores found in a biopsy, given the total number of cores, the volumes of the tumor nodules, and - very importantly - the prostate volume. Also, three applications are carried out: guidelines for the number of cores as a function of prostate volume, decision rules for insignificant versus significant CaP using number of positive cores, and, using prior distributions on total tumor size, Bayesian posterior probabilities for insignificant CaP and posterior median CaP. The model-based results have generality of application, take prostate volume into account, and provide attractive tradeoffs of specificity versus sensitivity. Copyright © 2015 John Wiley & Sons, Ltd.

  10. Effect of Head Position on Cerebrospinal Fluid Pressure in Cats: Comparison with Artificial Model

    Science.gov (United States)

    Klarica, Marijan; Radoš, Milan; Draganić, Pero; Erceg, Gorislav; Orešković, Darko; Maraković, Jurica; Bulat, Marin

    2006-01-01

    Aim To demonstrate that changes in the cerebrospinal fluid (CSF) pressure in the cranial cavity and spinal canal after head elevation from the horizontal level occur primarily due to the biophysical characteristics of the CSF system, ie, distensibility of the spinal dura. Methods Experiments in vivo were performed on cats and a new artificial model of the CSF system with dimensions similar to the CSF system in cats, consisting of non-distensible cranial and distensible spinal part. Measurements of the CSF pressure in the cranial and spinal spaces were performed in chloralose-anesthetized cats (n = 10) in the horizontal position on the base of a stereotaxic apparatus (reference zero point) and in the position in which the head was elevated to 5 cm and 10 cm above that horizontal position. Changes in the CSF pressure in the cranial and spinal part of the model were measured in the cranial part positioned in the same way as the head in cats (n = 5). Results When the cat was in the horizontal position, the values of the CSF pressure in the cranial (11.9 ± 1.1 cm H2O) and spinal (11.8 ± 0.6 cm H2O) space were not significantly different. When the head was elevated 5 cm or 10 cm above the reference zero point, the CSF pressure in the cranium significantly decreased to 7.7 ± 0.6 cm H2O and 4.7 ± 0.7 cm H2O, respectively, while the CSF pressure in the spinal space significantly increased to 13.8 ± 0.7 cm H2O and 18.5 ± 1.6 cm H2O, respectively (P<0.001 for both). When the artificial CSF model was positioned in the horizontal level and its cranial part elevated by 5 cm and 10 cm, the changes in the pressure were the same as those in the cats when in the same hydrostatic position. Conclusions The new model of the CSF system used in our study faithfully mimicked the changes in the CSF pressure in cats during head elevation in relation to the body. Changes in the pressure in the model were not accompanied by the changes in fluid volume in

  11. Effect of positional dependence and alignment strategy on modeling transcription factor binding sites

    Directory of Open Access Journals (Sweden)

    Quader Saad

    2012-07-01

    Full Text Available Abstract Background Many consensus-based and Position Weight Matrix-based methods for recognizing transcription factor binding sites (TFBS are not well suited to the variability in the lengths of binding sites. Besides, many methods discard known binding sites while building the model. Moreover, the impact of Information Content (IC and the positional dependence of nucleotides within an aligned set of TFBS has not been well researched for modeling variable-length binding sites. In this paper, we propose ML-Consensus (Mixed-Length Consensus: a consensus model for variable-length TFBS which does not exclude any reported binding sites. Methods We consider Pairwise Score (PS as a measure of positional dependence of nucleotides within an alignment of TFBS. We investigate how the prediction accuracy of ML-Consensus is affected by the incorporation of IC and PS with a particular binding site alignment strategy. We perform cross-validations for datasets of six species from the TRANSFAC public database, and analyze the results using ROC curves and the Wilcoxon matched-pair signed-ranks test. Results We observe that the incorporation of IC and PS in ML-Consensus results in statistically significant improvement in the prediction accuracy of the model. Moreover, the existence of a core region among the known binding sites (of any length is witnessed by the pairwise coexistence of nucleotides within the core length. Conclusions These observations suggest the possibility of an efficient multiple sequence alignment algorithm for aligning TFBS, accommodating known binding sites of any length, for optimal (or near-optimal TFBS prediction. However, designing such an algorithm is a matter of further investigation.

  12. Position and orientation estimation of fixed dipole emitters using an effective Hermite point spread function model.

    Science.gov (United States)

    Stallinga, Sjoerd; Rieger, Bernd

    2012-03-12

    We introduce a method for determining the position and orientation of fixed dipole emitters based on a combination of polarimetry and spot shape detection. A key element is an effective Point Spread Function model based on Hermite functions. The model offers a good description of the shape variations with dipole orientation and polarization detection channel, and provides computational advantages over the exact vectorial description of dipole image formation. The realized localization uncertainty is comparable to the free dipole case in which spots are rotationally symmetric and can be well modeled with a Gaussian. This result holds for all dipole orientations, for all practical signal levels, and for defocus values within the depth of focus, implying that the massive localization bias for defocused emitters with tilted dipole axis found with Gaussian spot fitting is eliminated.

  13. Psychological resilience, pain catastrophizing, and positive emotions: perspectives on comprehensive modeling of individual pain adaptation.

    Science.gov (United States)

    Sturgeon, John A; Zautra, Alex J

    2013-03-01

    Pain is a complex construct that contributes to profound physical and psychological dysfunction, particularly in individuals coping with chronic pain. The current paper builds upon previous research, describes a balanced conceptual model that integrates aspects of both psychological vulnerability and resilience to pain, and reviews protective and exacerbating psychosocial factors to the process of adaptation to chronic pain, including pain catastrophizing, pain acceptance, and positive psychological resources predictive of enhanced pain coping. The current paper identifies future directions for research that will further enrich the understanding of pain adaptation and espouses an approach that will enhance the ecological validity of psychological pain coping models, including introduction of advanced statistical and conceptual models that integrate behavioral, cognitive, information processing, motivational and affective theories of pain.

  14. Integrating remote sensing, geographic information systems and global positioning system techniques with hydrological modeling

    Science.gov (United States)

    Thakur, Jay Krishna; Singh, Sudhir Kumar; Ekanthalu, Vicky Shettigondahalli

    2017-07-01

    Integration of remote sensing (RS), geographic information systems (GIS) and global positioning system (GPS) are emerging research areas in the field of groundwater hydrology, resource management, environmental monitoring and during emergency response. Recent advancements in the fields of RS, GIS, GPS and higher level of computation will help in providing and handling a range of data simultaneously in a time- and cost-efficient manner. This review paper deals with hydrological modeling, uses of remote sensing and GIS in hydrological modeling, models of integrations and their need and in last the conclusion. After dealing with these issues conceptually and technically, we can develop better methods and novel approaches to handle large data sets and in a better way to communicate information related with rapidly decreasing societal resources, i.e. groundwater.

  15. Positive and normative modeling for Palmer amaranth control and herbicide resistance management.

    Science.gov (United States)

    Frisvold, George B; Bagavathiannan, Muthukumar V; Norsworthy, Jason K

    2017-06-01

    Dynamic optimization models are normative; they solve for what growers 'ought to do' to maximize some objective, such as long-run profits. While valuable for research, such models are difficult to solve computationally, limiting their applicability to grower resistance management education. While discussing properties of normative models in general, this study presents results of a specific positive model of herbicide resistance management, applied to Palmer amaranth control on a representative cotton farm. This positive model compares a proactive resistance management strategy to a reactive strategy with lower short-run costs, but greater risk of herbicide resistance developing. The proactive strategy can pay for itself within 1-4 years, with a yield advantage of 4% or less if the yield advantage begins within 1-2 years of adoption. Whether the proactive strategy is preferable is sensitive to resistance onset and yield losses, but less sensitive to cotton prices or baseline yields. Industry rebates to encourage residual herbicide use (to delay resistance to post-emergence treatments) may be too small to alter grower behavior or they may be paid to growers who would have used residuals anyway. Rebates change grower behavior over a relatively narrow range of model parameters. The size of rebates needed to induce a grower to adopt the proactive strategy declines significantly if growers extend their planning horizon from 1 year to 3-4 years. Whether proactive resistance management is more profitable than a reactive strategy is more sensitive to biological parameters than economic ones. Simulation results suggest growers with longer time horizons (perhaps younger ones) would be more responsive to rebate programs. More empirical work is needed to determine how much rebates increase residual use above what would occur without them. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  16. An enhanced positive reinforcement model for the severely impaired cocaine abuser.

    Science.gov (United States)

    Foote, J; Seligman, M; Magura, S; Handelsman, L; Rosenblum, A; Lovejoy, M; Arrington, K; Stimmel, B

    1994-01-01

    This article describes a cognitive-behavioral treatment approach that has been extensively modified to work with inner-city methadone-maintained cocaine users. Modifications were deemed essential to address the problems of engagement and retention in treatment that are typically encountered with this population. While this approach relies on such basic tenets of treatment as relapse prevention, cognitive restructuring, and psychoeducation, an understanding of the particular psychological vulnerabilities of this population has been incorporated into the model. The modified approach utilizes positive reinforcement extensively. This includes use of concrete reinforcers to facilitate initial engagement, and use of interpersonal reinforcers (therapist positive regard, attention, and respect) to increase program retention and sustain posttreatment change. Preliminary results indicate that 63% of patients can complete this intensive 6-month program, with considerable reductions in cocaine use and significant change in drug injection behavior.

  17. Analysis of the positive ionospheric response to a moderate geomagnetic storm using a global numerical model

    Directory of Open Access Journals (Sweden)

    A. A. Namgaladze

    Full Text Available Current theories of F-layer storms are discussed using numerical simulations with the Upper Atmosphere Model, a global self-consistent, time dependent numerical model of the thermosphere-ionosphere-plasmasphere-magnetosphere system including electrodynamical coupling effects. A case study of a moderate geomagnetic storm at low solar activity during the northern winter solstice exemplifies the complex storm phenomena. The study focuses on positive ionospheric storm effects in relation to thermospheric disturbances in general and thermospheric composition changes in particular. It investigates the dynamical effects of both neutral meridional winds and electric fields caused by the disturbance dynamo effect. The penetration of short-time electric fields of magnetospheric origin during storm intensification phases is shown for the first time in this model study. Comparisons of the calculated thermospheric composition changes with satellite observations of AE-C and ESRO-4 during storm time show a good agreement. The empirical MSISE90 model, however, is less consistent with the simulations. It does not show the equatorward propagation of the disturbances and predicts that they have a gentler latitudinal gradient. Both theoretical and experimental data reveal that although the ratio of [O]/[N2] at high latitudes decreases significantly during the magnetic storm compared with the quiet time level, at mid to low latitudes it does not increase (at fixed altitudes above the quiet reference level. Meanwhile, the ionospheric storm is positive there. We conclude that the positive phase of the ionospheric storm is mainly due to uplifting of ionospheric F2-region plasma at mid latitudes and its equatorward movement at low latitudes along geomagnetic field lines caused by large-scale neutral wind circulation and the passage of travelling atmospheric disturbances (TADs. The calculated zonal electric field disturbances also help

  18. Position-specific isotope modeling of organic micropollutants transformations through different reaction pathways

    Science.gov (United States)

    Jin, Biao; Rolle, Massimo

    2016-04-01

    Organic compounds are produced in vast quantities for industrial and agricultural use, as well as for human and animal healthcare [1]. These chemicals and their metabolites are frequently detected at trace levels in fresh water environments where they undergo degradation via different reaction pathways. Compound specific stable isotope analysis (CSIA) is a valuable tool to identify such degradation pathways in different environmental systems. Recent advances in analytical techniques have promoted the fast development and implementation of multi-element CSIA. However, quantitative frameworks to evaluate multi-element stable isotope data and incorporating mechanistic information on the degradation processes [2,3] are still lacking. In this study we propose a mechanism-based modeling approach to simultaneously evaluate concentration as well as bulk and position-specific multi-element isotope evolution during the transformation of organic micropollutants. The model explicitly simulates position-specific isotopologues for those atoms that experience isotope effects and, thereby, provides a mechanistic description of isotope fractionation occurring at different molecular positions. We validate the proposed approach with the concentration and multi-element isotope data of three selected organic micropollutants: dichlorobenzamide (BAM), isoproturon (IPU) and diclofenac (DCF). The model precisely captures the dual element isotope trends characteristic of different reaction pathways and their range of variation consistent with observed multi-element (C, N) bulk isotope fractionation. The proposed approach can also be used as a tool to explore transformation pathways in scenarios for which position-specific isotope data are not yet available. [1] Schwarzenbach, R.P., Egli, T., Hofstetter, T.B., von Gunten, U., Wehrli, B., 2010. Global Water Pollution and Human Health. Annu. Rev. Environ. Resour. doi:10.1146/annurev-environ-100809-125342. [2] Jin, B., Haderlein, S.B., Rolle, M

  19. Indirect investment in real estate: Listed companies and funds

    OpenAIRE

    Suarez, Jose L.; Vassalo, Amparo

    2005-01-01

    In Europe today, there are two main vehicles for indirect investment in real estate; real estate investment funds, on the one hand, and, on the other, listed real estate companies. With these instruments, not only does the investor take a position in the real estate market, he/she also acquires different risk/return structures which may vary according to the instrument being used. In some European countries, real estate companies have modified their financial structure and tax position by ado...

  20. Properties of type IV plaster considering variation in the mold/model position during setting stage

    Directory of Open Access Journals (Sweden)

    Tarcisio José de Arruda Paes Junior

    2010-04-01

    Full Text Available Objective: To assess the influence of the position of the mold during the setting stage of type IV stone plaster Durone (Dentsply Ind. Com., Rio de Janeiro, Brazil, on the following properties: surface hardness and roughness. Methods: For the roughness test, two groups (n=6 in the form of pellets were prepared. In the first group, the surface of the base of the device was turned down during the plaster setting stage (N, in the second group this position was inverted, which has been described as an act of capsize it (E. For analysis, a roughness meter with reading precision of 0.01 μm was used. With regard to the hardness analysis, two groups with conical-shaped samples were obtained. The plasters were left to set under the same conditions of the mold/model position described for the previous experiment. Hardness measurement was performed in a durometer with a spherical penetrating tip for Rockwell readout. Three measurements were performed for each test specimen in both tests. Results: The hardness (N - 39.8, standard deviation = 3.3, E - 30.8, standard deviation = 5.6 and roughness data (N - 0.67, standard deviation = 0.17, E - 0.74, standard deviation = 0.13 submitted to the Student’s-t test (5% showed no statistically significant differences for the roughness test (0.489, but showed statistically significant differences for the hardness test (0.014. Conclusion: The variation in the mold/model position influenced the final characteristics of the specimens in terms of hardness, since those obtained with the capsize technique showed lower surface hardness, whereas for roughness these differences were not statistically significant.

  1. Importance of direct and indirect triggered seismicity

    CERN Document Server

    Helmstetter, A; Helmstetter, Agnes; Sornette, Didier

    2003-01-01

    Using the simple ETAS branching model of seismicity, which assumes that each earthquake can trigger other earthquakes, we quantify the role played by the cascade of triggered seismicity in controlling the rate of aftershock decay as well as in the overall level of seismicity in the presence of a constant external seismicity source. We show that, in this model, the proportion of triggered seismicity is equal to the proportion of secondary plus later-generation aftershocks, and is given by the average number of triggered events per earthquake. Based on these results and on the observation that a large fraction of seismicity are triggered earthquakes, we conclude that similarly a large fraction of aftershocks occurring a few hours or days after a mainshock are triggered indirectly by the mainshock.

  2. Indirect Collider Signals for Extra Dimensions

    CERN Document Server

    Hewett, J L

    1999-01-01

    A recent suggestion that quantum gravity may become strong near the weak scale has several testable consequences. In addition to probing for the new large (submillimeter) extra dimensions associated with these theories via gravitational experiments, one could search for the Kaluza Klein towers of massive gravitons which are predicted in these models and which can interact with the fields of the Standard Model. Here we examine the indirect effects of these massive gravitons being exchanged in fermion pair production in \\epem\\ annihilation and Drell-Yan production at hadron colliders. In the latter case, we examine a novel feature of this theory, which is the contribution of gluon gluon initiated processes to lepton pair production. We find that these processes provide strong bounds, up to several TeV, on the string scale which are essentially independent of the number of extra dimensions. In addition, we analyze the angular distributions for fermion pair production with spin-2 graviton exchanges and demonstrat...

  3. The role of internal forward models and proprioception in hand position estimation.

    Science.gov (United States)

    Yavari, Fatemeh; Towhidkhah, Farzad; Ahmadi-Pajouh, Mohammad-Ali; Darainy, Mohammad

    2015-09-01

    Our ability to properly move and react in different situations is largely dependent on our perception of our limbs' position. At least three sources - vision, proprioception, and internal forward models (FMs) - seem to contribute to this perception. To the best of our knowledge, the effect of each source has not been studied individually. Specifically, role of FM has been ignored in some previous studies. We hypothesized that FM has a critical role in subjects' perception which needs to be considered in the relevant studies to obtain more reliable results. Therefore, we designed an experiment with the goal of investigating FM and proprioception role in subjects' perception of their hand's position. Three groups of subjects were recruited in the study. Based on the experiment design, it was supposed that subjects in different groups relied on proprioception, FM, and both of them for estimating their unseen hand's position. Comparing the results of three groups revealed significant difference between their estimation' errors. FM provided minimum estimation error, while proprioception had a bias error in the tested region. Integrating proprioception with FM decreased this error. Integration of two Gaussian functions, fitted to the error distribution of FM and proprioception groups, was simulated and created a mean error value almost similar to the experimental observation. These results suggest that FM role needs to be considered when studying the perceived position of the limbs. This can lead to gain better insights into the mechanisms underlying the perception of our limbs' position which might have potential clinical and rehabilitation applications, e.g., in the postural control of elderly which are at high risk of falls and injury because of deterioration of their perception with age.

  4. Modelling the controls on the front position of a tidewater glacier in Svalbard

    Science.gov (United States)

    Otero, Jaime; Navarro, Francisco J.; Lapazaran, Javier J.; Welty, Ethan; Puczko, Darek; Finkelnburg, Roman

    2017-04-01

    Calving is an important mass-loss process at ice sheet and marine-terminating glacier margins, but identifying and quantifying its principal driving mechanisms remains challenging. Hansbreen is a grounded tidewater glacier in southern Spitsbergen, Svalbard, with a rich history of field and remote sensing observations. The available data make this glacier suitable for evaluating mechanisms and controls on calving, some of which are considered in this paper. We use a full-Stokes thermomechanical 2D flow model (Elmer/Ice), paired with a crevasse-depth calving criterion, to estimate Hansbreen’s front position at a weekly time resolution. The basal sliding coefficient is re-calibrated every four weeks by solving an inverse model. We investigate the possible role of backpressure at the front (a function of ice mélange concentration) and the depth of water filling crevasses by examining the model’s ability to reproduce the observed seasonal cycles of terminus advance and retreat. Our results suggest that the ice-mélange pressure plays an important role in the seasonal advance and retreat of the ice front, and that the crevasse-depth calving criterion, when driven by modelled surface meltwater, closely replicates observed variations in terminus position. These results suggest that tidewater glacier behavior is influenced by both oceanic and atmospheric processes, and that neither of them should be ignored.

  5. Design of a dynamic positioning system using model-based control

    Directory of Open Access Journals (Sweden)

    Asgeir J. Sørensen

    1996-04-01

    Full Text Available A dynamic positioning (DP system includes different control functions for automatic positioning and guidance of marine vessels by means of thruster and propeller actions. This paper describes the control functions which provide station-keeping and tracking. The DP controller is designed using model-based control, where a new modified LQG feedback controller and a model reference feedforward controller are applied. A reference model calculates appropriate reference trajectories. Since it is not desirable nor even possible to counteract the wave-frequency movement caused by first-order wave loads, the control action of the propulsion system should be produced by the low frequency part of the vessel movement caused by current, wind and second-order mean and slowly varying wave loads. A Kalman filter based state estimator and a Luenberger observer are used to compute the low-frequency feedback and feedforward control signals. Full-scale experiments with a supply vessel demonstrate the performance of the proposed controller.

  6. An Integrated Model of Motion, Steering, Positioning and Stabilization of an Unmanned Autonomous Maritime Vehicle

    Directory of Open Access Journals (Sweden)

    Miroslaw Gerigk

    2015-12-01

    Full Text Available In the paper the aim of an interdisciplinary research is presented. The research method is introduced. An object the unmanned autonomous maritime vehicle is briefly described. The key research problem concerns a combined model of the vehicle motion including the loads of lift and hydrodynamic nature. The model takes into account the gravity and displacement forces, resistance and thrust forces, lift and other hydrodynamic forces. One of the major research tasks is to precisely predict the position of the vehicle. To do that an integrated model of acquiring, analyzing and processing the signals is necessary. The processed signals may then be used for the precise steering of the vehicle. The vehicle should be equipped with a stabilization system. Some information on an integrated steering, positioning and stabilization system of the vehicle is briefly presented in the paper. Such the system enables to obtain a fully autonomous vehicle. Some information on the propulsion and underwater energy supply systems are presented in the paper, too.

  7. Positive Steady States of a Prey-predator Model with Diffusion and Non-monotone Conversion Rate

    Institute of Scientific and Technical Information of China (English)

    Rui PENG; Ming Xin WANG; Wen Yan CHEN

    2007-01-01

    In this paper,we study the positive steady states of a prey-predator model with di .usion throughout and a non-monotone conversion rate under the homogeneous Dirichlet boundary condition. We obtain some results of the existence and non-existence of positive steady states.The stability and uniqueness of positive steady states are also discussed.

  8. Cooperation under indirect reciprocity and imitative trust.

    Directory of Open Access Journals (Sweden)

    Serguei Saavedra

    Full Text Available Indirect reciprocity, a key concept in behavioral experiments and evolutionary game theory, provides a mechanism that allows reciprocal altruism to emerge in a population of self-regarding individuals even when repeated interactions between pairs of actors are unlikely. Recent empirical evidence show that humans typically follow complex assessment strategies involving both reciprocity and social imitation when making cooperative decisions. However, currently, we have no systematic understanding of how imitation, a mechanism that may also generate negative effects via a process of cumulative advantage, affects cooperation when repeated interactions are unlikely or information about a recipient's reputation is unavailable. Here we extend existing evolutionary models, which use an image score for reputation to track how individuals cooperate by contributing resources, by introducing a new imitative-trust score, which tracks whether actors have been the recipients of cooperation in the past. We show that imitative trust can co-exist with indirect reciprocity mechanisms up to a threshold and then cooperation reverses -revealing the elusive nature of cooperation. Moreover, we find that when information about a recipient's reputation is limited, trusting the action of third parties towards her (i.e. imitating does favor a higher collective cooperation compared to random-trusting and share-alike mechanisms. We believe these results shed new light on the factors favoring social imitation as an adaptive mechanism in populations of cooperating social actors.

  9. Cooperation under indirect reciprocity and imitative trust.

    Science.gov (United States)

    Saavedra, Serguei; Smith, David; Reed-Tsochas, Felix

    2010-10-27

    Indirect reciprocity, a key concept in behavioral experiments and evolutionary game theory, provides a mechanism that allows reciprocal altruism to emerge in a population of self-regarding individuals even when repeated interactions between pairs of actors are unlikely. Recent empirical evidence show that humans typically follow complex assessment strategies involving both reciprocity and social imitation when making cooperative decisions. However, currently, we have no systematic understanding of how imitation, a mechanism that may also generate negative effects via a process of cumulative advantage, affects cooperation when repeated interactions are unlikely or information about a recipient's reputation is unavailable. Here we extend existing evolutionary models, which use an image score for reputation to track how individuals cooperate by contributing resources, by introducing a new imitative-trust score, which tracks whether actors have been the recipients of cooperation in the past. We show that imitative trust can co-exist with indirect reciprocity mechanisms up to a threshold and then cooperation reverses -revealing the elusive nature of cooperation. Moreover, we find that when information about a recipient's reputation is limited, trusting the action of third parties towards her (i.e. imitating) does favor a higher collective cooperation compared to random-trusting and share-alike mechanisms. We believe these results shed new light on the factors favoring social imitation as an adaptive mechanism in populations of cooperating social actors.

  10. Risk model in stage IB1-IIB cervical cancer with positive node after radical hysterectomy

    Directory of Open Access Journals (Sweden)

    Chen Z

    2016-05-01

    Full Text Available Zhilan Chen,1,2,* Kecheng Huang,1,* Zhiyong Lu,1,3 Song Deng,1,4 Jiaqiang Xiong,1 Jia Huang,1 Xiong Li,5 Fangxu Tang,1 Zhihao Wang,6 Haiying Sun,1 Lin Wang,1 Shasha Zhou,1 Xiaoli Wang,1 Yao Jia,1 Ting Hu,1 Juan Gui,7 Dongyi Wan,1 Ding Ma,1 Shuang Li,1 Shixuan Wang11Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Techonology, Wuhan, 2Department of Obstetrics and Gynecology, Wuhan General Hospital of Guangzhou Military Command, Wuhan, 3Hubei Key Laboratory of Embryonic Stem Cell Research, Tai-He Hospital, Hubei University of Medicine, Shiyan, Hubei, 4Department of Obstetrics and Gynecology, University Hospital of Hubei University for Nationalities, Enshi, Hubei, 5Department of Obstetrics and Gynecology, Wuhan Central Hospital, Wuhan, 6Department of Pathology and Pathophysiology, Key Laboratory of Ministry of Education of China for Neurological Disorders, Huazhong University of Science and Techonology, Wuhan, 7Department of Obstetrics and Gynecology, Renmin Hospital, Wuhan University, Wuhan, People’s Republic of China*These authors contributed equally to this workAbstract: The purpose of this study was to identify risk factors in patients with surgically treated node-positive IB1-IIB cervical cancer and to establish a risk model for disease-free survival (DFS and overall survival (OS. A total of 170 patients who underwent radical hysterectomy and bilateral pelvic lymphadenectomy as primary treatment for node-positive International Federation of Gynaecology and Obstetrics (FIGO stage IB1-IIB cervical cancer from January 2002 to December 2008 were retrospectively analyzed. Five published risk models were evaluated in this population. The variables, including common iliac lymph node metastasis and parametrial invasion, were independent predictors of outcome in a multivariate analysis using a Cox regression model. Three distinct prognostic groups (low, intermediate, and high risk

  11. THE EXISTENCE OF POSITIVE PERIODIC SOLUTIONS IN A LOGISTIC DIFFERENCE MODEL WITH A FEEDBACK CONTROL

    Institute of Scientific and Technical Information of China (English)

    刘智钢; 陈安平

    2004-01-01

    Consider the following nonautonomous delayed periodic logistic difference model with feedback control term N(k+1)=N(k)exp[r(k)-a1(k)N(k)-a2(k)N(k-τ(k))-c(k)u(k)],Δu(k)=-a(k)u(k)+b(k)N(k-τ(k)), which describes the evolution of a single species. The existence of a positive periodic solution is established by using the method of Mawhin's coincidence degree. This work has important significance in both theory and applications.

  12. An Intrinsic Model for the Polarization Position Angle Swing Observed in QSO 1150+812

    Institute of Scientific and Technical Information of China (English)

    Shan-Jie Qian; Xi-Zhen Zhang

    2004-01-01

    The rapid polarization position angle swing of ~ 180° observed in QSO 1150+812 at 2cm by Kochenov and Gabuzda is quite a regular event. One interesting property of the event is that, during the time of the swing the polarized flux density remained almost constant. We suggest that such an event can be explained in terms of a relativistic thin shock propagating through a uniform helical magnetic field, giving rise to relativistic aberration effects as the transverse field component rotates. The model may also be applicable to other similar events in which variations in polarization are not accompanied by variations in total flux density.

  13. Transition probabilities and interacting boson-fermion model description of positive parity states in 117Sb

    Science.gov (United States)

    Lobach, Yu. N.; Bucurescu, D.

    1998-09-01

    The Doppler shift attenuation method was used to determine lifetimes in the picosecond region for excited states of 117Sb populated with the (α,2nγ) reaction at Eα=27.2 MeV. Interacting boson-fermion model calculations explain reasonably well the main features of the positive parity levels known up to about 2.5 MeV excitation. The mixing of the lowest one-quasiparticle 9/2+ state with the intruder (2p-1h) 9/2+ state, as well as the quadrupole deformation of the intruder band are also discussed.

  14. Indirect photobiomodulation in functional networks

    Science.gov (United States)

    Liu, Timon Cheng-Yi; Zhu, Wei-Wei; Yang, Xiang-Bo

    2012-12-01

    Photobiomodulation (PBM) is a non-damaged modulation of laser irradiation or monochromatic light (LI) on a biosystem function. It depends on whether the function is in its function-specific homeostasis (FSH), a negative feedback response for the function to be performed perfectly. Many redundant pathways (RPs) maintain the same cellular function. The full activation of any of RPs can maintain a normal function in its FSH, but partial activation of all the RPs can only maintain a dysfunctional function far from its FSH. A PBM may self-adaptively modulate the activation of a partially activated RP of a normal function until it is fully activated and the normal function is then upgraded. This PBM is called indirect PBM (iPBM). The iPBM on cells such as tumor cells, myoblast cells and fibroblasts and other biosystems and their applications would be reviewed in this paper.

  15. Aerosols indirectly warm the Arctic

    Directory of Open Access Journals (Sweden)

    T. Mauritsen

    2010-07-01

    Full Text Available On average, airborne aerosol particles cool the Earth's surface directly by absorbing and scattering sunlight and indirectly by influencing cloud reflectivity, life time, thickness or extent. Here we show that over the central Arctic Ocean, where there is frequently a lack of aerosol particles upon which clouds may form, a small increase in aerosol loading may enhance cloudiness thereby likely causing a climatologically significant warming at the ice-covered Arctic surface. Under these low concentration conditions cloud droplets grow to drizzle sizes and fall, even in the absence of collisions and coalescence, thereby diminishing cloud water. Evidence from a case study suggests that interactions between aerosol, clouds and precipitation could be responsible for attaining the observed low aerosol concentrations.

  16. Semi-empirical chemical model for indirect advanced oxidation of Acid Orange 7 using an unmodified carbon fabric cathode for H2O2 production in an electrochemical reactor.

    Science.gov (United States)

    Ramírez, B; Rondán, V; Ortiz-Hernández, L; Silva-Martínez, S; Alvarez-Gallegos, A

    2016-04-15

    A commercial Unidirectional Carbon Fabric piece was used to design an electrode for the cathodic O2 reduction reaction in a divided (by a Nafion(®) 117 membrane) parallel plate reactor. The anode was a commercial stainless steel mesh. Under this approach it is feasible to produce H2O2 at low energy (2.08 kWh kg(-1) H2O2) in low ionic acidic medium. In the catholyte side the H2O2 can be activated with Fe(2+) to develop the Fenton reagent. It was found that Acid Orange 7 (AO7) indirect oxidation (in the concentration range of 0.12-0.24 mM) by Fenton chemistry follows a first order kinetic equation. The energy required for 0.24 mM AO7 degradation is 1.04 kWhm(-3). From each experimental AO7 oxidation the main parameters (a, mM and k, min(-1)) of the first order kinetic equation are obtained. These parameters can be correlated with AO7 concentration in the concentration range studied. Based on this method a semi-empirical chemical model was developed to predict the AO7 abatement, by means of Fenton chemistry. Good AO7 oxidation predictions can be made in the concentration range studied. A detailed discussion of the energy required for oxidizing AO7 and the accuracy of the chemical model to predict its oxidation is included in this paper.

  17. Translocation of positively and negatively charged polystyrene nanoparticles in an in vitro placental model.

    Science.gov (United States)

    Kloet, Samantha K; Walczak, Agata P; Louisse, Jochem; van den Berg, Hans H J; Bouwmeester, Hans; Tromp, Peter; Fokkink, Remco G; Rietjens, Ivonne M C M

    2015-10-01

    To obtain insight in translocation of nanoparticles across the placental barrier, translocation was studied for one positively and two negatively charged polystyrene nanoparticles (PS-NPs) of similar size in an in vitro model. The model consisted of BeWo b30 cells, derived from a human choriocarcinoma grown on a transwell insert forming a cell layer that separates an apical from a basolateral compartment. PS-NPs were characterized with respect to size, surface charge, morphology and protein corona. Translocation of PS-NPs was not related to PS-NP charge. Two PS-NPs were translocated across the BeWo transwell model to a lower extent than amoxicillin, a model compound known to be translocated over the placental barrier to only a limited extent, whereas one PS-NP showed a slightly higher translocation. Studies on the effect of transporter inhibitors on the translocation of the PS-NPs indicated that their translocation was not mediated by known transporters and mainly dependent on passive diffusion. It is concluded that the BeWo b30 model can be used as an efficient method to get an initial qualitative impression about the capacity of NPs to translocate across the placental barrier and set priorities in further in vivo studies on translocation of NPs to the fetus.

  18. Stabilizing PID controllers for a single-link biomechanical model with position, velocity, and force feedback.

    Science.gov (United States)

    Iqbal, Kamran; Roy, Anindo

    2004-12-01

    In this paper we address the problem of PID stabilization of a single-link inverted pendulum-based biomechanical model with force feedback, two levels of position and velocity feedback, and with delays in all the feedback loops. The novelty of the proposed model lies in its physiological relevance, whereby both small and medium latency sensory feedbacks from muscle spindle (MS), and force feedback from Golgi tendon organ (GTO) are included in the formulation. The biomechanical model also includes active and passive viscoelastic feedback from Hill-type muscle model and a second-order low-pass function for muscle activation. The central nervous system (CNS) regulation of postural movement is represented by a proportional-integral-derivative (PID) controller. Padé approximation of delay terms is employed to arrive at an overall rational transfer function of the biomechanical model. The Hermite-Biehler theorem is then used to derive stability results, leading to the existence of stabilizing PID controllers. An algorithm for selection of stabilizing feedback gains is developed using the linear matrix inequality (LMI) approach.

  19. A Bayesian model for censored positive count data in evaluating breast cancer progression.

    Science.gov (United States)

    Yeh, Hung-Wen; Jiang, Yu; Garrard, Lili; Lei, Yang; Gajewski, Byron

    2013-01-01

    Basic science researchers transplant human cancer tissues from patients with ductal carcinoma in situ (DCIS) to animals and observe the progression of the disease. Successful transplants show invasion of human tissues across mammary ducts in animal fat pads and cause DCIS-like lesions in one or more ducts. In this work, we consider data from a recent publication of breast cancer research where positive counts of affected ducts may be subject to censoring. We fit the data with zero-truncated Poisson (ZTP) models with an informative prior of gamma. Due to the zero-truncation and right censoring, posterior distributions may not be conventional gamma and are estimated through Markov chain Monte Carlo and grid approximation. For each of the two cell lines, we fit a model with group-specific parameters for DCIS subtypes classified by the cell surface biomarkers, and another model with a homogeneous parameter across groups. Models are compared by the Deviance Information Criterion (DIC). For the chosen prior parameter values, Bayes estimates are comparative to the maximum likelihood estimates, and the DIC favors the simpler model in both cell lines.

  20. FREQUENCY OF TOXOPLASMA GONDII IN CATS IN METOPOLITAN LIMA AND CONCORDANCE BETWEEN INDIRECT IMMUNOFLUORESCENCE AND INDIRECT HAEMAGLUTINATION TECHNIQUES

    OpenAIRE

    Cerro T., Luis; Laboratorio de Medicina Veterinaria Preventiva, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima; Chávez V., Amanda; Laboratorio de Medicina Veterinaria Preventiva, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima; Casas A., Eva; Laboratorio de Medicina Veterinaria Preventiva, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima; Suárez A., Francisco; Laboratorio de Medicina Veterinaria Preventiva, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima.; Rubio V., Alicia; Laboratorio de Medicina Veterinaria Preventiva, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima

    2012-01-01

    The aim of the present work was to estimate the frequency of antibodies anti- Toxoplasma gondii in cats of Lima city, and to determine the rate of concordance between the Indirect Immunofluorescence (IFI) and Indirect Haemaglutination (HAI) assays. A total of 178 cat serum samples were collected in veterinary clinics of varios districts of Lima. The results showed 11.2 ± 4.6% (HAI) and 17.9 ± 5.6% (IFI) positive serums to T. gondii, and without statiscal differences due to sex and age group. ...

  1. School climate and teachers' beliefs and attitudes associated with implementation of the positive action program: a diffusion of innovations model.

    Science.gov (United States)

    Beets, Michael W; Flay, Brian R; Vuchinich, Samuel; Acock, Alan C; Li, Kin-Kit; Allred, Carol

    2008-12-01

    Teacher- and school-level factors influence the fidelity of implementation of school-based prevention and social character and development (SACD) programs. Using a diffusion of innovations framework, the relationships among teacher beliefs and attitudes towards a prevention/SACD program and the influence of a school's administrative support and perceptions of school connectedness, characteristics of a school's climate, were specified in two cross-sectional mediation models of program implementation. Implementation was defined as the amount of the programs' curriculum delivered (e.g., lessons taught), and use of program-specific materials in the classroom (e.g., ICU boxes and notes) and in relation to school-wide activities (e.g., participation in assemblies). Teachers from 10 elementary schools completed year-end process evaluation reports for year 2 (N = 171) and 3 (N = 191) of a multi-year trial. Classroom and school-wide material usage were each favorably associated with the amount of the curriculum delivered, which were associated with teachers' attitudes toward the program which, in turn, were related to teachers' beliefs about SACD. These, in turn, were associated with teachers' perceptions of school climate. Perceptions of school climate were indirectly related to classroom material usage and both indirectly and directly related to the use of school-wide activities. Program developers need to consider the importance of a supportive environment on program implementation and attempt to incorporate models of successful school leadership and collaboration among teachers that foster a climate promoting cohesiveness, shared visions, and support.

  2. Position dependent mismatch discrimination on DNA microarrays – experiments and model

    Directory of Open Access Journals (Sweden)

    Michel Wolfgang

    2008-12-01

    Full Text Available Abstract Background The propensity of oligonucleotide strands to form stable duplexes with complementary sequences is fundamental to a variety of biological and biotechnological processes as various as microRNA signalling, microarray hybridization and PCR. Yet our understanding of oligonucleotide hybridization, in particular in presence of surfaces, is rather limited. Here we use oligonucleotide microarrays made in-house by optically controlled DNA synthesis to produce probe sets comprising all possible single base mismatches and base bulges for each of 20 sequence motifs under study. Results We observe that mismatch discrimination is mostly determined by the defect position (relative to the duplex ends as well as by the sequence context. We investigate the thermodynamics of the oligonucleotide duplexes on the basis of double-ended molecular zipper. Theoretical predictions of defect positional influence as well as long range sequence influence agree well with the experimental results. Conclusion Molecular zipping at thermodynamic equilibrium explains the binding affinity of mismatched DNA duplexes on microarrays well. The position dependent nearest neighbor model (PDNN can be inferred from it. Quantitative understanding of microarray experiments from first principles is in reach.

  3. Estimating the direct and indirect effects of secondary organic aerosols using ECHAM5-HAM

    Directory of Open Access Journals (Sweden)

    D. O'Donnell

    2011-08-01

    Full Text Available Secondary organic aerosol (SOA has been introduced into the global climate-aerosol model ECHAM5/HAM. The SOA module handles aerosols originating from both biogenic and anthropogenic sources. The model simulates the emission of precursor gases, their chemical conversion into condensable gases, the partitioning of semi-volatile condenable species into the gas and aerosol phases. As ECHAM5/HAM is a size-resolved model, a new method that permits the calculation of partitioning of semi-volatile species between different size classes is introduced. We compare results of modelled organic aerosol concentrations against measurements from extensive measurement networks in Europe and the United States, running the model with and without SOA. We also compare modelled aerosol optical depth against measurements from the AERONET network of grond stations. We find that SOA improves agreement between model and measurements in both organic aerosol mass and aerosol optical depth, but does not fully correct the low bias that is present in the model for both of these quantities. Although many models now include SOA, any overall estimate of the direct and indirect effects of these aerosols is still lacking. This paper makes a first step in that direction. The model is applied to estimate the direct and indirect effects of SOA under simulated year 2000 conditions. The modelled SOA spatial distribution indicates that SOA is likely to be an important source of free and upper tropospheric aerosol. We find a negative shortwave (SW forcing from the direct effect, amounting to −0.31 Wm−2 on the global annual mean. In contrast, the model indicates a positive indirect effect of SOA of +0.23 Wm−2, arising from the enlargement of particles due to condensation of SOA, together with an enhanced coagulation sink of small particles. In the longwave, model results are a direct effect of +0.02 Wm−2 and an indirect effect of −0.03 Wm−2

  4. Modeling shear-induced CHO cell damage in a rotary positive displacement pump.

    Science.gov (United States)

    Kamaraju, Hari; Wetzel, Kenneth; Kelly, William J

    2010-01-01

    Rotary lobe pumps are commonly used in the biotechnology industry for a variety of purposes. Shear damage to animal cells within the rotary lobe pump can adversely affect the product yield or purity during, for example, cell concentration via cross-flow filtration. In this research, CHO cells grown in 20-L bioreactors were fed to a rotary lobe pump in both single pass and recycle experiments were conducted at different RPMs and "slip" conditions. The results indicate that the slip flow rate more severely impacts the viability of the CHO cells than the pump RPM. A novel mathematical modeling approach is presented that predicts shear rates in all of the positive displacement pump's slip regions, and then predicts cell death vs. operating conditions. This model accounts for the complex flow situation that results from changes to RPM, backpressure and pump geometry (i.e., clearances).

  5. Cognition and the five-factor model of the positive and negative syndrome scale in schizophrenia.

    Science.gov (United States)

    Rodriguez-Jimenez, Roberto; Bagney, Alexandra; Mezquita, Laura; Martinez-Gras, Isabel; Sanchez-Morla, Eva-Maria; Mesa, Natalia; Ibañez, Manuel-Ignacio; Diez-Martin, Justo; Jimenez-Arriero, Miguel-Angel; Lobo, Antonio; Santos, Jose-Luis; Palomo, Tomas

    2013-01-01

    Different exploratory and confirmatory factorial analyses of the Positive and Negative Syndrome Scale (PANSS) have found a number of factors other than the original positive, negative, and general psychopathology. Based on a review of previous studies and using confirmatory factor analyses (CFA), Wallwork et al. (Schizophr Res 2012; 137: 246-250) have recently proposed a consensus five-factor structure of the PANSS. This solution includes a cognitive factor which could be a useful measure of cognition in schizophrenia. Our objectives were 1) to study the psychometric properties (factorial structure and reliability) of this consensus five-factor model of the PANSS, and 2) to study the relationship between executive performance assessed using the Wisconsin Card Sorting Test (WCST) and the proposed PANSS consensus cognitive factor (composed by items P2-N5-G11). This cross-sectional study included a final sample of 201 Spanish outpatients diagnosed with schizophrenia. For our first objective, CFA was performed and Cronbach's alphas of the five factors were calculated; for the second objective, sequential linear regression analyses were used. The results of the CFA showed acceptable fit indices (NNFI=0.94, CFI=0.95, RMSEA=0.08). Cronbach's alphas of the five factors were adequate. Regression analyses showed that this five-factor model of the PANSS explained more of the WCST variance than the classical three-factor model. Moreover, higher cognitive factor scores were associated with worse WCST performance. These results supporting its factorial structure and reliability provide robustness to this consensus PANSS five-factor model, and indicate some usefulness of the cognitive factor in the clinical assessment of schizophrenic patients. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. A 1-dimensional statistical mechanics model for nucleosome positioning on genomic DNA

    CERN Document Server

    Tesoro, S; Morozov, A N; Sulaiman, N; Marenduzzo, D

    2015-01-01

    The first level of folding of DNA in eukaryotes is provided by the so called '10nm chromatin fibre', where DNA wraps around histone proteins (approx. 10 nm in size) to form nucleosomes, which go on to create a zig zagging 'bead on a string' structure. In this work we present a one dimensional statistical mechanics model to study nucleosome positioning within one such 10 nm fibre. We consider both the case of homogeneous DNA, where the problem can be mapped to a Tonks gas, and that of genomic sheep DNA, where our modelling is informed by high-resolution nucleosome positioning data. First, we consider the simple, analytically solvable, case where nucleosomes are assumed to be point like. Then, we perform numerical simulations to gauge the effect of their finite size on the nucleosomal distribution probabilities. Finally, we compare nucleosome distributions and simulated nuclease digestion patterns for the two cases (homogeneous and sheep DNA), thereby providing testable predictions of the effect of sequence on ...

  7. Construction of microRNA functional families by a mixture model of position weight matrices

    Directory of Open Access Journals (Sweden)

    Je-Keun Rhee

    2013-10-01

    Full Text Available MicroRNAs (miRNAs are small regulatory molecules that repress the translational processes of their target genes by binding to their 3′ untranslated regions (3′ UTRs. Because the target genes are predominantly determined by their sequence complementarity to the miRNA seed regions (nucleotides 2–7 which are evolutionarily conserved, it is inferred that the target relationships and functions of the miRNA family members are conserved across many species. Therefore, detecting the relevant miRNA families with confidence would help to clarify the conserved miRNA functions, and elucidate miRNA-mediated biological processes. We present a mixture model of position weight matrices for constructing miRNA functional families. This model systematically finds not only evolutionarily conserved miRNA family members but also functionally related miRNAs, as it simultaneously generates position weight matrices representing the conserved sequences. Using mammalian miRNA sequences, in our experiments, we identified potential miRNA groups characterized by similar sequence patterns that have common functions. We validated our results using score measures and by the analysis of the conserved targets. Our method would provide a way to comprehensively identify conserved miRNA functions.

  8. Construction of microRNA functional families by a mixture model of position weight matrices.

    Science.gov (United States)

    Rhee, Je-Keun; Shin, Soo-Yong; Zhang, Byoung-Tak

    2013-01-01

    MicroRNAs (miRNAs) are small regulatory molecules that repress the translational processes of their target genes by binding to their 3' untranslated regions (3' UTRs). Because the target genes are predominantly determined by their sequence complementarity to the miRNA seed regions (nucleotides 2-7) which are evolutionarily conserved, it is inferred that the target relationships and functions of the miRNA family members are conserved across many species. Therefore, detecting the relevant miRNA families with confidence would help to clarify the conserved miRNA functions, and elucidate miRNA-mediated biological processes. We present a mixture model of position weight matrices for constructing miRNA functional families. This model systematically finds not only evolutionarily conserved miRNA family members but also functionally related miRNAs, as it simultaneously generates position weight matrices representing the conserved sequences. Using mammalian miRNA sequences, in our experiments, we identified potential miRNA groups characterized by similar sequence patterns that have common functions. We validated our results using score measures and by the analysis of the conserved targets. Our method would provide a way to comprehensively identify conserved miRNA functions.

  9. Comparison of "direct" and "indirect" nuclear cystography in the diagnosis of vesicoureteric reflux.

    Science.gov (United States)

    Khriesat, I; Khriesat, S; Hazza, I

    2001-01-01

    This study was undertaken to compare "direct" and "indirect" nuclear cystography for the detection of vesicoureteral reflux (VUR). Forty-five children (15 males and 30 females), ranging in age from 5 months to 10 years, were studied at the King Hussein Medical Center, Amman, Jordan between January 1998 and December 1999, using both direct (catheter) and indirect techniques of nuclear cystography (NC). Of the 82 ureters that could be compared, 32 ureters were positive for VUR on the direct technique while only 20 ureters showed VUR on the indirect technique (sensitivity 62%). Nine ureters, which did not show VUR on the direct cystogram, were read as positive on the indirect cystogram (specificity 82%). The false positive results of indirect nuclear cystogram make it invalid for VUR screening program, while the ease of assessment and low radiation dose from the direct NC has made this the recommended test for screening and follow-up of VUR.

  10. Comparison of "Direct" and "Indirect" Nuclear Cystography in the Diagnosis of Vesicoureteric Reflux

    Directory of Open Access Journals (Sweden)

    Khriesat Imad

    2001-01-01

    Full Text Available This study was undertaken to compare "direct" and "indirect" nuclear cystography for the detection of vesicoureteral reflux (VUR. Forty-five children (15 males and 30 females, ranging in age from 5 months to 10 years, were studied at the King Hussein Medical Center, Amman, Jordan between January 1998 and December 1999, using both direct (catheter and indirect techniques of nuclear cystography (NC. Of the 82 ureters that could be compared, 32 ureters were positive for VUR on the direct technique while only 20 ureters showed VUR on the indirect technique (sensitivity 62%. Nine ureters, which did not show VUR on the direct cystogram, were read as positive on the indirect cystogram (specificity 82%. The false positive results of indirect nuclear cystogram make it invalid for VUR screening program, while the ease of assessment and low radiation dose from the direct NC has made this the recommended test for screening and follow-up of VUR.

  11. Estimation of orientation and position of cervical vertebrae for segmentation with active shape models

    Science.gov (United States)

    Zamora, Gilberto; Sari-Sarraf, Hamed; Mitra, Sunanda; Long, L. Rodney

    2001-07-01

    Radiologists are always looking for more reliable and robust methods to help them assess, describe and classify bone structures in x-ray images. Although, in the recent years, computer-assisted techniques have proven to be useful in this regard, they still face difficult challenges such as inter-subject variability in shape and a lack of contrast in the digitized images of radiographs. These challenges have focused the attention of the computer vision research community on techniques that employ deformable models. One such technique, i.e., Active Shape Models (ASM), has received significant attention due to its ability to capture the shape variability and to deal with the poor quality of the images in a straightforward manner. However, as is often the case with iterative optimization techniques, success of the ASM search step is highly dependent on the initial positioning of the mean shape on the target image. Within the specific framework of automatic, cervical vertebra segmentation, we have developed and tested an up-front preprocessing algorithm that estimates the orientation and position of the cervical vertebrae in x-ray images and leads to a more accurate, initial placement of the mean shape. The algorithm estimates the orientation of the spine by calculating parallel-beam line integrals of the x-ray images. The position of the spine is estimated by considering the density of edges perpendicular to the line integral that gives the estimate of the orientation. The output of the algorithm is a bounding box surrounding the cervical spine area. Morphometric points placed by expert radiologists on a set of 40, digitized radiographs were used to quantify the efficacy of the estimation. This test yielded acceptable results in estimating the orientation and the locating of the cervical spine.

  12. A positive event dependence model for self-controlled case series with applications in postmarketing surveillance.

    Science.gov (United States)

    Simpson, Shawn E

    2013-03-01

    A primary objective in the application of postmarketing drug safety surveillance is to ascertain the relationship between time-varying drug exposures and recurrent adverse events (AEs) related to health outcomes. The self-controlled case series (SCCS) method is one approach to analysis in this context. It is based on a conditional Poisson regression model, which assumes that events at different time points are conditionally independent given the covariate process. This requirement is problematic when the occurrence of an event can alter the future event risk. In a clinical setting, for example, patients who have a first myocardial infarction (MI) may be at higher subsequent risk for a second. In this work, we propose the positive dependence self-controlled case series (PD-SCCS) method: a generalization of SCCS that allows the occurrence of an event to increase the future event risk, yet maintains the advantages of the original model by controlling for fixed baseline covariates and relying solely on data from cases. As in the SCCS model, individual-level baseline parameters drop out of the PD-SCCS likelihood. Data sources used for postmarketing surveillance can contain tens of millions of people, so in this situation it is particularly advantageous that PD-SCCS avoids doing a costly estimation of individual parameters. We develop expressions for large sample inference and optimization for PD-SCCS and compare the results of our generalized model with the more restrictive SCCS approach. Copyright © 2013, The International Biometric Society.

  13. Design, modelling and control of a micro-positioning actuator based on magnetic shape memory alloys

    Science.gov (United States)

    Minorowicz, Bartosz; Leonetti, Giuseppe; Stefanski, Frederik; Binetti, Giulio; Naso, David

    2016-07-01

    This paper presents an actuator based on magnetic shape memory alloys (MSMAs) suitable for precise positioning in a wide range (up to 1 mm). The actuator is based on the spring returned operating mode and uses a Smalley wave spring to maintain the same operating parameters of a classical coil spring, while being characterized by a smaller dimension. The MSMA element inside the actuator provides a deformation when excited by an external magnetic field, but its behavior is characterized by an asymmetric and saturated hysteresis. Thus, two models are exploited in this work to represent such a non-linear behavior, i.e., the modified and generalized Prandtl-Ishlinskii models. These models are particularly suitable for control purposes due to the existence of their analytical inversion that can be easily exploited in real time control systems. To this aim, this paper investigates three closed-loop control strategies, namely a classical PID regulator, a PID regulator with direct hysteresis compensation, and a combined PID and feedforward compensation strategy. The effectiveness of both modelling and control strategies applied to the designed MSMA-based actuator is illustrated by means of experimental results.

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

    Directory of Open Access Journals (Sweden)

    W. Xie

    2013-11-01

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

  15. Indirect Lightning Safety Assessment Methodology

    Energy Technology Data Exchange (ETDEWEB)

    Ong, M M; Perkins, M P; Brown, C G; Crull, E W; Streit, R D

    2009-04-24

    Lightning is a safety hazard for high-explosives (HE) and their detonators. In the However, the current flowing from the strike point through the rebar of the building The methodology for estimating the risk from indirect lighting effects will be presented. It has two parts: a method to determine the likelihood of a detonation given a lightning strike, and an approach for estimating the likelihood of a strike. The results of these two parts produce an overall probability of a detonation. The probability calculations are complex for five reasons: (1) lightning strikes are stochastic and relatively rare, (2) the quality of the Faraday cage varies from one facility to the next, (3) RF coupling is inherently a complex subject, (4) performance data for abnormally stressed detonators is scarce, and (5) the arc plasma physics is not well understood. Therefore, a rigorous mathematical analysis would be too complex. Instead, our methodology takes a more practical approach combining rigorous mathematical calculations where possible with empirical data when necessary. Where there is uncertainty, we compensate with conservative approximations. The goal is to determine a conservative estimate of the odds of a detonation. In Section 2, the methodology will be explained. This report will discuss topics at a high-level. The reasons for selecting an approach will be justified. For those interested in technical details, references will be provided. In Section 3, a simple hypothetical example will be given to reinforce the concepts. While the methodology will touch on all the items shown in Figure 1, the focus of this report is the indirect effect, i.e., determining the odds of a detonation from given EM fields. Professor Martin Uman from the University of Florida has been characterizing and defining extreme lightning strikes. Using Professor Uman's research, Dr. Kimball Merewether at Sandia National Laboratory in Albuquerque calculated the EM fields inside a Faraday-cage type

  16. Indirect determinations of the top quark mass

    CERN Document Server

    Giudice, Gian F; Strumia, Alessandro

    2015-01-01

    We give a complete analysis of indirect determinations of the top quark mass in the Standard Model by introducing a systematic procedure to identify observables that receive quantum corrections enhanced by powers of $M_t$. We propose to use flavour physics as a tool to extract the top quark mass. Although present data give only a poor determination, we show how future theoretical and experimental progress in flavour physics can lead to an accuracy in $M_t$ well below 2 GeV. We revisit determinations of $M_t$ from electroweak data, showing how an improved measurement of the $W$ mass leads to an accuracy well below 1 GeV.

  17. Metamotifs - a generative model for building families of nucleotide position weight matrices

    Directory of Open Access Journals (Sweden)

    Down Thomas A

    2010-06-01

    Full Text Available Abstract Background Development of high-throughput methods for measuring DNA interactions of transcription factors together with computational advances in short motif inference algorithms is expanding our understanding of transcription factor binding site motifs. The consequential growth of sequence motif data sets makes it important to systematically group and categorise regulatory motifs. It has been shown that there are familial tendencies in DNA sequence motifs that are predictive of the family of factors that binds them. Further development of methods that detect and describe familial motif trends has the potential to help in measuring the similarity of novel computational motif predictions to previously known data and sensitively detecting regulatory motifs similar to previously known ones from novel sequence. Results We propose a probabilistic model for position weight matrix (PWM sequence motif families. The model, which we call the 'metamotif' describes recurring familial patterns in a set of motifs. The metamotif framework models variation within a family of sequence motifs. It allows for simultaneous estimation of a series of independent metamotifs from input position weight matrix (PWM motif data and does not assume that all input motif columns contribute to a familial pattern. We describe an algorithm for inferring metamotifs from weight matrix data. We then demonstrate the use of the model in two practical tasks: in the Bayesian NestedMICA model inference algorithm as a PWM prior to enhance motif inference sensitivity, and in a motif classification task where motifs are labelled according to their interacting DNA binding domain. Conclusions We show that metamotifs can be used as PWM priors in the NestedMICA motif inference algorithm to dramatically increase the sensitivity to infer motifs. Metamotifs were also successfully applied to a motif classification problem where sequence motif features were used to predict the family of

  18. Indirect discrimination and breast screening.

    Science.gov (United States)

    Botha, J L; Manku-Scott, T K; Moledina, F; Williams, A

    1993-01-01

    Uptake of screening services in inner-city communities has been low, particularly in older age groups, lower social classes, and ethnic minorities. In Leicester City, where up to 25% of the population belong to ethnic minorities, this may have important implications for breast screening. We randomly sampled 701 inner-city women aged 45 to 64 years, stratified by neighborhood and by women's "likely home language." Trained interviewers succeeded in interviewing 79% of those eligible, and we report here a preliminary analysis of 413 respondents. Knowledge of breast cancer and screening varied markedly and significantly by actual language: 60.4% of English-speaking and 12.5% of non-English-speaking women correctly answered 10 or more questions (of 14) about breast cancer and screening (chi 2(1) = 89.884; P = .000). Despite that, 80% or more women stated their intention to attend for screening and assessment if necessary, irrespective of neighborhood, language, age, or social class. We suggest that the difference in knowledge between language groups arose from indirect discrimination in the way in which health-related information is disseminated in British society. However, after providing appropriate screening information, we report similarly high intended acceptance rates in the two language groups.

  19. An ion species model for positive ion sources - part II analysis of hydrogen isotope effects

    CERN Document Server

    Surrey, E

    2014-01-01

    A one dimensional model of the magnetic multipole volume plasma source has been developed for application to intense ion/neutral atom beam injectors. The model uses plasma transport coefficients for particle and energy flow to create a detailed description of the plasma parameters along an axis parallel to that of the extracted beam. In this paper the isotopic modelling of positive hydrogenic ions is considered and compared with experimental data from the neutral beam injectors of the Joint European Torus. The use of the code to gain insights into the processes contributing to the ratios of the ionic species is demonstrated and the conclusion is drawn that 75% of the atomic ion species arises from ionization of dissociated molecules and 25% from dissociation of the molecular ions. However whilst the former process is independent of the filter field, the latter is sensitive to the change in distribution of fast and thermal electrons produced by the magnetic filter field and an optimum combination of field stre...

  20. Indirect Self-Destructiveness and Emotional Intelligence.

    Science.gov (United States)

    Tsirigotis, Konstantinos

    2016-06-01

    While emotional intelligence may have a favourable influence on the life and psychological and social functioning of the individual, indirect self-destructiveness exerts a rather negative influence. The aim of this study has been to explore possible relations between indirect self-destructiveness and emotional intelligence. A population of 260 individuals (130 females and 130 males) aged 20-30 (mean age of 24.5) was studied by using the Polish version of the chronic self-destructiveness scale and INTE, i.e., the Polish version of the assessing emotions scale. Indirect self-destructiveness has significant correlations with all variables of INTE (overall score, factor I, factor II), and these correlations are negative. The intensity of indirect self-destructiveness differentiates significantly the height of the emotional intelligence and vice versa: the height of the emotional intelligence differentiates significantly the intensity of indirect self-destructiveness. Indirect self-destructiveness has negative correlations with emotional intelligence as well as its components: the ability to recognize emotions and the ability to utilize emotions. The height of emotional intelligence differentiates the intensity of indirect self-destructiveness, and vice versa: the intensity of indirect self-destructiveness differentiates the height of emotional intelligence. It seems advisable to use emotional intelligence in the prophylactic and therapeutic work with persons with various types of disorders, especially with the syndrome of indirect self-destructiveness.

  1. Mysid and fish zooplanktivory in Lake Ontario: quantification of direct and indirect effects

    Science.gov (United States)

    Gal, Gideon; Rudstam, Lars G.; Mills, Edward L.; Lantry, Jana R.; Johannsson, Ora E.; Greene, C.

    2011-01-01

    Mysis relicta and planktivorous fish feed on zooplankton in Lake Ontario and form a trophic triangle that includes intraguild predation by fish on mysids. Thus, fish affect zooplankton both directly and indirectly. To evaluate the importance of alewife (Alosa pseudoharengus), rainbow smelt (Osmerus mordax), and mysids as zooplanktivores in Lake Ontario, we measured abundances and distributions, assessed diets, and computed mysid and fish consumption rates based on bioenergetics models. We further estimated indirect effects by comparing clearance rates given observed and potential mysid distributions. Estimated consumption rates varied widely with season and water depth and ranged between 2.6 x 10-3 and 1.3 gm-2day-1 for mysids and between 1.4 x 10-3 and 0.5 gm-2day-1 for fish, representing a daily removal of zooplankton of up to 10.2%-day-1 and 2.0%-day-1 by mysids and fish, respectively. Mysid planktivory exceeded fish planktivory in May and August, but fish planktivory dominated in October. Estimated mysid planktivory rates were 2- to 90-fold lower than the potential rate if mysids moved to temperatures that maximized their predation rates, suggesting an indirect positive effect of fish on zooplankton.

  2. BDNF Val66Met, stress, and positive mothering: Differential susceptibility model of adolescent trait anxiety.

    Science.gov (United States)

    Chen, Jie; Yu, Jing; Liu, Yujie; Zhang, Leilei; Zhang, Jianxin

    2015-08-01

    Etiological research has indicated the gene-environment interaction (G × E) on adolescent anxiety. This study aimed to examine how the BDNF Val66Met polymorphism interacted with stressful life events and positive mothering to influence youth trait anxiety. The study sample included 780 community adolescents of Chinese Han ethnicity (M = 13.6, 51.3% females). Participants' trait anxiety, exposure to stressful life events, and mother's warmth-reasoning were assessed by self-reported questionnaires. We found that BDNF Val66Met polymorphism significantly moderated the influences of stressful life events and mother's warmth-reasoning on adolescent anxiety. The influences were significantly greater in adolescents carrying one or two Val allele than those with Met/Met genotype. Moreover, the G × E interactions were more consistent with the differential susceptibility than the diathesis-stress model. Adolescents carrying Val allele who were more susceptible to adversity were also more likely to benefit from supportive experiences. These findings provide novel evidence for the role of BDNF Val66Met as a genetic susceptibility modulating the influences of stressful life events and mother's warmth-reasoning on adolescent anxiety. We speculate that BDNF Val66Met may moderate anxious youths' responses to mindfulness-based stress reduction program and family-based treatment targeting the enhancement of positive parenting. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. A one-dimensional statistical mechanics model for nucleosome positioning on genomic DNA.

    Science.gov (United States)

    Tesoro, S; Ali, I; Morozov, A N; Sulaiman, N; Marenduzzo, D

    2016-02-12

    The first level of folding of DNA in eukaryotes is provided by the so-called '10 nm chromatin fibre', where DNA wraps around histone proteins (∼10 nm in size) to form nucleosomes, which go on to create a zig-zagging bead-on-a-string structure. In this work we present a one-dimensional statistical mechanics model to study nucleosome positioning within one such 10 nm fibre. We focus on the case of genomic sheep DNA, and we start from effective potentials valid at infinite dilution and determined from high-resolution in vitro salt dialysis experiments. We study positioning within a polynucleosome chain, and compare the results for genomic DNA to that obtained in the simplest case of homogeneous DNA, where the problem can be mapped to a Tonks gas. First, we consider the simple, analytically solvable, case where nucleosomes are assumed to be point-like. Then, we perform numerical simulations to gauge the effect of their finite size on the nucleosomal distribution probabilities. Finally we compare nucleosome distributions and simulated nuclease digestion patterns for the two cases (homogeneous and sheep DNA), thereby providing testable predictions of the effect of sequence on experimentally observable quantities in experiments on polynucleosome chromatin fibres reconstituted in vitro.

  4. Barrier Lyapunov function-based model-free constraint position control for mechanical systems

    Energy Technology Data Exchange (ETDEWEB)

    Han, Seong Ik; Ha, Hyun Uk; Lee, Jang Myung [Pusan National University, Busan (Korea, Republic of)

    2016-07-15

    In this article, a motion constraint control scheme is presented for mechanical systems without a modeling process by introducing a barrier Lyapunov function technique and adaptive estimation laws. The transformed error and filtered error surfaces are defined to constrain the motion tracking error in the prescribed boundary layers. Unknown parameters of mechanical systems are estimated using adaptive laws derived from the Lyapunov function. Then, robust control used the conventional sliding mode control, which give rise to excessive chattering, is changed to finite time-based control to alleviate undesirable chattering in the control action and to ensure finite-time error convergence. Finally, the constraint controller from the barrier Lyapunov function is designed and applied to the constraint of the position tracking error of the mechanical system. Two experimental examples for the XY table and articulated manipulator are shown to evaluate the proposed control scheme.

  5. Observation and modeling of thermoelastic strain in Southern California Integrated GPS Network daily position time series

    Science.gov (United States)

    Prawirodirdjo, Linette; Ben-Zion, Yehuda; Bock, Yehuda

    2006-02-01

    We suggest that strain in the elastic part of the Earth's crust induced by surface temperature variations is a significant contributor to the seasonal variations observed in the spatially filtered daily position time series of Southern California Integrated GPS Network (SCIGN) stations. We compute the predicted thermoelastic strain from the observed local atmospheric temperature record assuming an elastically decoupled layer over a uniform elastic half-space and compare the seasonal variations in thermoelastic strain to the horizontal GPS position time series. We consider three regions (Palmdale, 29 Palms, and Idyllwild), each with one temperature station and three to six GPS stations. The temperature time series is used to compute thermoelastic strain at each station on the basis of its relative location in the temperature field. For each region we assume a wavelength for the temperature field that is related to the local topography. The depth of the decoupled layer is inferred from the phase delay between the temperature record and the GPS time series. The relative amplitude of strain variation at each GPS station, calculated to be on the order of 0.1 μstrain, is related to the relative location of that station in the temperature field. The goodness of fit between model and data is evaluated from the relative amplitudes of the seasonal signals, as well as the appropriateness of the chosen temperature field wavelength and decoupled layer depth. The analysis shows a good fit between the predicted strains and the GPS time series. This suggests that the model captures the key first-order ingredients that determine the thermoelastic strain in a given area. The results can be used to improve the signal/noise ratio in GPS data.

  6. A dynamical model of general intelligence: The positive manifold of intelligence by mutualism

    NARCIS (Netherlands)

    van der Maas, H.L.J.; Dolan, C.V.; Grasman, R.P.P.P.; Wicherts, J.M.; Huizenga, H.M.; Raijmakers, M.E.J.

    2006-01-01

    Scores on cognitive tasks used in intelligence tests correlate positively with each other, that is, they display a positive manifold of correlations. The positive manifold is often explained by positing a dominant latent variable, the g factor, associated with a single quantitative cognitive or biol

  7. A Graph Model for calculating the probability for a moving cyclic disturbance interacting at a particular spatial position

    CERN Document Server

    Brown, D

    2003-01-01

    The analysis follows an earlier paper - Brown (2003) - which analysed a moving disturbance using a directed cyclic graph defined as Interrelated Fluctuating Entities (IFEs) of /STATE/, /SPACE/, /alphaTIME/, /betaTIME/. This paper provides a statistical analysis of the alternative positions in space and state of an IFE for a defined total time magnitude. The probability for a freely moving entity interacting in a particular spatial position is calculated and a formulation is derived for the minimum locus of uncertainty in position and momentum. The model has proven amenable to computer modelling (the assistance of University College London Computer Science department is gratefully acknowledged). A computer model is available on request.

  8. A kinetic model for evaluating the dependence of the quantum yield of nano-TiO{sub 2} based photocatalysis on light intensity, grain size, carrier lifetime, and minority carrier diffusion coefficient: Indirect interfacial charge transfer

    Energy Technology Data Exchange (ETDEWEB)

    Liu Baoshun, E-mail: liubaoshun@126.co [Key Laboratory of Silicate Materials Science and Engineering, Ministry of Education, Wuhan, Hubei 430070 (China) and School of Material Science and Technology, Wuhan University of Technology, Wuhan, Hubei 430070 (China); Zhao Xiujian [Key Laboratory of Silicate Materials Science and Engineering, Ministry of Education, Wuhan, Hubei 430070 (China)

    2010-04-30

    A model based on spherical TiO{sub 2} nanoparticles was developed to study heterogeneous photocatalysis based on TiO{sub 2} in the case of indirect interfacial charge transfer. In this model, the effect of light intensity (I{sub 0}), grain size (r{sub 0}), carrier lifetime (tau{sub p}), and minority carrier diffusion coefficient (D{sub p}) on the quantum yield (QY) of photocatalytic reactions was investigated in detail. Under conditions of sufficiently low incident-light intensity, the QY was found to be propor toI{sub 0}, while it decreased rapidly with an increase in I{sub 0}. In addition, the QY went to zero at a critically high light intensity. Furthermore, the QY was found to decrease with increasing r{sub 0} due to the bulk-recombination loss, and the effect of r{sub 0} on the QY became increasingly stronger with the increase in I{sub 0}. The QY decreased with the decrease in tau{sub p} and D{sub p}, which was more apparent at the critically high I{sub 0}. Under conditions of low [(RH{sub 2}){sub aq}], the QY increased with an increase in [(RH{sub 2}){sub aq}], while it remained nearly constant at high [(RH{sub 2}){sub aq}] due to the fact that the photoinduced electron interfacial transfer became the limiting step for photocatalytic reactions in the case of high [(RH{sub 2}){sub aq}].

  9. RESEARCH AND MATHEMATICAL MODELING OF TURBULENT BOUNDARY LAYER AT POSITIVE PRESSURE GRADIENT

    Directory of Open Access Journals (Sweden)

    Vitaliy Mamchuk

    2016-06-01

    Full Text Available Purpose: Mathematical modeling of complex turbulent near-wall flows, that occur during the flow of airfoils, is impossible without understanding the nature of the flow in boundary layer. From a mathematical point of view, the calculation of such flows, because in practical problems they regarded as turbulent, and the characteristics of turbulence are largely dependent on the geometry of the profile of the longitudinal component of the average velocity of the near-wall flow. Based on this, the purpose of this work is studying and mathematical modeling of turbulent near-wall flows in the interaction with the real streamlined surface, that has certain features, such as the curvature, roughness, etc., as well as the study and research of the influence of the pressure gradient on the empirical coefficients, parameters of the flow, velocity profiles and friction stress. Methods: We performed the calculations using numerical finite-difference marching method with algebraic model of turbulent viscosity coefficient. Results: In this paper we present some results of the numerical study of the effect of the positive pressure gradient on the empirical coefficients of the transition zone and the law of the near-wall and the outer-wall areas. Discussion: Comparison of the calculated results with the experimental data shows that the proposed approaches provide an opportunity to simulate the flow as close as possible to their physical properties. Presented mathematical model for the calculation of turbulent boundary layers and near-wall flows makes it possible to calculate such a complex and valuable from a practical point of view type of the flow as the aerodynamic trail behind the streamlined body.

  10. Neutron-capture cross sections from indirect measurements

    Directory of Open Access Journals (Sweden)

    Scielzo N.D.

    2012-02-01

    Full Text Available Cross sections for compound-nuclear reactions reactions play an important role in models of astrophysical environments and simulations of the nuclear fuel cycle. Providing reliable cross section data remains a formidable task, and direct measurements have to be complemented by theoretical predictions and indirect methods. The surrogate nuclear reactions method provides an indirect approach for determining cross sections for reactions on unstable isotopes, which are difficult or impossible to measure otherwise. Current implementations of the method provide useful cross sections for (n,f reactions, but need to be improved upon for applications to capture reactions.

  11. Evidence for Limited Indirect Aerosol Forcing in Stratocumulus

    Science.gov (United States)

    Ackerman, Andrew S.; Toon, O. B.; Stevens, D. E.

    2003-01-01

    Increases in cloud cover and condensed water contribute more than half of the indirect aerosol effect in an ensemble of general circulation model (GCM) simulations estimating the global radiative forcing of anthropogenic aerosols. We use detailed simulations of marine stratocumulus clouds and airborne observations of ship tracks to show that increases in cloud cover and condensed water in reality are far less than represented by the GCM ensemble. Our results offer an explanation for recent simplified inverse climate calculations indicating that indirect aerosol effects are greatly exaggerated in GCMs.

  12. A review of indirect searches for particle dark matter

    CERN Document Server

    Gaskins, Jennifer M

    2016-01-01

    The indirect detection of dark matter annihilation and decay using observations of photons, charged cosmic rays, and neutrinos offers a promising means of identifying the particle nature of this elusive component of the universe. The last decade has seen substantial advances in observational data sets, complemented by new insights from numerical simulations, which together have enabled for the first time strong constraints on dark matter particle models, and have revealed several intriguing hints of possible signals. This review provides an introduction to indirect detection methods and an overview of recent results in the field.

  13. Neutron-capture Cross Sections from Indirect Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Escher, J E; Burke, J T; Dietrich, F S; Ressler, J J; Scielzo, N D; Thompson, I J

    2011-10-18

    Cross sections for compound-nuclear reactions play an important role in models of astrophysical environments and simulations of the nuclear fuel cycle. Providing reliable cross section data remains a formidable task, and direct measurements have to be complemented by theoretical predictions and indirect methods. The surrogate nuclear reactions method provides an indirect approach for determining cross sections for reactions on unstable isotopes, which are difficult or impossible to measure otherwise. Current implementations of the method provide useful cross sections for (n,f) reactions, but need to be improved upon for applications to capture reactions.

  14. Testing indirect effect of consumer attitudes toward a product

    DEFF Research Database (Denmark)

    Hrubá, Renata; Sudzina, Frantisek

    2016-01-01

    a questionnaire in 2010-2011. The model is estimated using probit analysis to predict relationship between producer and consumer in decision-making when buying a new type of cheese and to examine consumer attitudes toward food origins and nutrient food security. It can be concluded that the indirect effect (e...

  15. Direct and indirect community effects of rebuilding plans

    DEFF Research Database (Denmark)

    Andersen, Ken Haste; Rice, Jack C.

    2010-01-01

    of the marine community. Using size- and trait-based single-species and community models, a general assessment is made of the direct and indirect ecological consequences of a rebuilding plan based on a reduction in fishing mortality. If fishing mortality is sufficiently reduced, the time-scale of rebuilding...

  16. Global positive expectancies of the self and adolescents' substance use avoidance: testing a social influence mediational model.

    Science.gov (United States)

    Carvajal, Scott C; Evans, Richard I; Nash, Susan G; Getz, J Greg

    2002-06-01

    Grounded in theories of global positive expectancies and social influences of behavior, this investigation posited a model in which global positive expectancies are related to substance use as mediated by attitudes, subjective norms, self-efficacy, and intentions. Using a cohort sample (n = 525), structural equation modeling was employed to test the hypothesized predictions of future substance use. The findings suggest that, relative to adolescents with lower global positive expectancies, adolescents with higher global positive expectancies use substances less frequently over time because of their protective attitudinal and control-oriented perceptions towards that behavior. Additionally, results from the current investigation also extend prior findings on the factor structure of global positive expectancies, suggesting these expectancies can be viewed as a second-order factor representing optimism and two components of hope-agency and pathways.

  17. Indirect control of flexible demand for power system applications

    DEFF Research Database (Denmark)

    Sossan, Fabrizio

    demand is addressed. We investigate the subject considering both how to achieve a shift in the consumption of the single DSRs, and how to generate the indirect control signal for a population of DSRs in order to support the operation of the grid. In the former case, we develop algorithms that achieve...... a shift in the consumption according to an indirect control signal. We present from simple control algorithms with a few requirements up to model predictive control strategies. The performance of the indirect control algorithms are compared by means of hardware-in-the-loop simulations using Power...... Flexhouse, a facility of DTU Elektro for testing demand side management strategies, as experimental site. In the latter case, we develop four applications where flexible demand is required to support power system operations. The applications are: integration of the operation of flexible demand...

  18. Intergenerational continuity in economic hardship, parental positivity, and positive parenting: The association with child behavior.

    Science.gov (United States)

    Jeon, Shinyoung; Neppl, Tricia K

    2016-02-01

    The current study examined intergenerational continuity in economic hardship, parental positivity, and positive parenting across generations based on both the family stress model (FSM) and the family resilience framework. The study included 220 generation 1 (G1) parents, their target youth (generation 2: G2) who participated from adolescence through adulthood, and the target's child (generation 3: G3). Assessments included observational and self-report measures. Results indicated that G1 economic hardship negatively influenced both G1 positivity and G1 positive parenting. Similarly, G2 economic hardship was negatively related to both G2 positivity and G2 positive parenting, which in turn was associated with G3 positive behavior to G2. For both G1 and G2, parental positivity mediated the association between economic hardship and positive parenting. G2 economic hardship was indirectly related to G3 positive behavior through G2 parental positivity and positive parenting. An important finding is that the intergenerational continuity of economic hardship, positivity, and positive parenting were transmitted from G1 to G2. Results suggest that even in times of economic adversity, parental positivity and positive parenting were transmitted from G1 parents to their G2 youth during adulthood. Such continuity seems to influence the positive behavior of the G3 children.

  19. 2D positive streamer modelling in NTP air under extreme pulse fronts. What about runaway electrons?

    Science.gov (United States)

    Marode, E.; Dessante, Ph; Tardiveau, P.

    2016-12-01

    Using a 2D model, an attempt is made to understand the properties and aspects of a diffuse discharge, appearing in a positive point-to-plane gap submitted to very high voltage pulses. After presenting the model, comparisons between the computed low and high pulse heights of 10 kV and 50 kV, respectively, will be shown and analysed. A streamer ionising wave is still formed, but its role in ionising a region of low field is replaced by the role of providing a plasma within which the electrons will benefit from the presence of a high electrical field meant to induce strong electron collision activities. A comparison between the aspect of the computed and experimental discharge carried out in the same conditions at 50 kV will be presented, which seems to be in agreement with the diffuse aspect. Although the difference in order of magnitude of the speed of development and the height of the current must be underlined, similarities between the structures of both situations will, however, be recognised. A high probability of obtaining highly energetic electrons and runaways (RAEs) will also be derived following a simple approach.

  20. Electromagnetic Field Analysis and Modeling of a Relative Position Detection Sensor for High Speed Maglev Trains

    Science.gov (United States)

    Xue, Song; He, Ning; Long, Zhiqiang

    2012-01-01

    The long stator track for high speed maglev trains has a tooth-slot structure. The sensor obtains precise relative position information for the traction system by detecting the long stator tooth-slot structure based on nondestructive detection technology. The magnetic field modeling of the sensor is a typical three-dimensional (3-D) electromagnetic problem with complex boundary conditions, and is studied semi-analytically in this paper. A second-order vector potential (SOVP) is introduced to simplify the vector field problem to a scalar field one, the solution of which can be expressed in terms of series expansions according to Multipole Theory (MT) and the New Equivalent Source (NES) method. The coefficients of the expansions are determined by the least squares method based on the boundary conditions. Then, the solution is compared to the simulation result through Finite Element Analysis (FEA). The comparison results show that the semi-analytical solution agrees approximately with the numerical solution. Finally, based on electromagnetic modeling, a difference coil structure is designed to improve the sensitivity and accuracy of the sensor. PMID:22778652