WorldWideScience

Sample records for current models propose

  1. A three-phase model proposal for the evolution of scientific communication: from first print periodicals to current electronic communication system

    Directory of Open Access Journals (Sweden)

    Patrícia Bertin

    Full Text Available Scientific communication has undergone deep transformations, since the emergence of Internet. Aiming to provide further thought on the evolution of scientific communication, this paper features a historical overview of the scientific communication advances over the last twenty years through a three-phase model for the evolution of the electronic journal and the preprints services, and presents Brazilian contemporary panorama for scientific communication. The three-phase model presented in this work is an adaptation of that one proposed by Tenopir et al. (2003 to describe the patterns of journal use by scientists since 1990. The early evolutionary phase followed the emergence of the first digital journals and the creation of repositories in the Web for publishing preliminary versions of scientific literature on the author’s initiative; by that time, most academics reproved electronic publishing initiatives. From 1996 and forward, in the consolidation phase, electronic journals were commonly identical to their print counterparts; the acceptance of the electronic format began to increase, and preprint services got underway in several disciplines. The advanced evolutionary phase started with the world discussion on open access to scientific information. The comparison of the current electronic journal with that viewed by enthusiasts in the first years of the 1990s shows that some aspects still remain to be improved in electronic formal and informal communication, towards effective dissemination of scientific information.

  2. Models of current sintering

    Science.gov (United States)

    Angst, Sebastian; Engelke, Lukas; Winterer, Markus; Wolf, Dietrich E.

    2017-06-01

    Densification of (semi-)conducting particle agglomerates with the help of an electrical current is much faster and more energy efficient than traditional thermal sintering or powder compression. Therefore, this method becomes more and more common among experimentalists, engineers, and in industry. The mechanisms at work at the particle scale are highly complex because of the mutual feedback between current and pore structure. This paper extends previous modelling approaches in order to study mixtures of particles of two different materials. In addition to the delivery of Joule heat throughout the sample, especially in current bottlenecks, thermoelectric effects must be taken into account. They lead to segregation or spatial correlations in the particle arrangement. Various model extensions are possible and will be discussed.

  3. The municipality borders and interdepartmental Antioquia in current territorial proposals

    National Research Council Canada - National Science Library

    Lucella Gómez Giraldo; Diana Carolina Sanchez Zapata; Dairo Correa Gutiérrez; Juan Darío Goyes Garzón

    2014-01-01

    ... that have not played a central role in the current proposals of land use planning and ordering developed by the Department of Antioquia, but which should be considered because they have particular...

  4. Brand Value - Proposed Model Danrise

    Directory of Open Access Journals (Sweden)

    Daniel Nascimento Pereira da Silva

    2011-12-01

    Full Text Available Brands have taken dominance in the strategies of enterprises once they are able to generate feelings, sensations and emotions in their clients. These values, value for the enterprises and for the brands themselves, are not measurable. A strong brand configures itself as the highest representative of an enterprise and the brand is regarded as an asset of the enterprise. The evolution of a brand, as an intangible and strategic asset, becomes more vitally important for the enterprises, as a way of maximizing the results. This need, whether of the market or the enterprises, justifies the direction of the research for this vector – the value of the brand. A main objective of the research is to present a new model of brand evaluation. This model is supported by a tangible and intangible aspects and the intangible aspect, evaluates the knowledge and capacity of their managers and workers to build a brand with value through the correct ordering of the priorities of the dimensions of the proposed model. The model was tested on the brand ‗Blue Rise.‘ 

  5. Negative nominal interest rates: History and current proposals

    OpenAIRE

    Ilgmann, Cordelius; Menner, Martin

    2011-01-01

    Given the renewed interest in negative interest rates as a means for overcoming the zero bound on nominal interest rates, this article reviews the history of negative nominal interest rates and gives a brief survey over the current proposals that received popular attention in the wake of the financial crisis of 2007/08. It is demonstrated that taxing money proposals have a long intellectual history and that instead of being the conjecture of a monetary crank, they are a serious policy proposa...

  6. The municipality borders and interdepartmental Antioquia in current territorial proposals

    Directory of Open Access Journals (Sweden)

    Lucella Gómez Giraldo

    2014-07-01

    Full Text Available This article aims to provide elements to make visible the historical, socio-economic, political and administrative dynamics that characterize the interdepartmental border towns, particularly those that have not played a central role in the current proposals of land use planning and ordering developed by the Department of Antioquia, but which should be considered because they have particular features that may have great significance in the land use planning and ordering proposals, aimed to reduce municipal and regional imbalances. For this purpose, the analysis is based on the case study of the creation processes of the municipalities of La Pintada, Vigía del Fuerte and Yondó and of the socio-territorial relations and interactions that occur inside and outside of Antioquia.

  7. Proposed hybrid superconducting fault current limiter for distribution systems

    Energy Technology Data Exchange (ETDEWEB)

    Elmitwally, A. [Elect. Eng. Dept., Mansoura University, Mansoura 35516 (Egypt)

    2009-11-15

    In this paper, a new hybrid fault current limiter is proposed for primary distribution systems. It incorporates a high temperature superconducting element in parallel with other two branches. The first is an inductive impedance to share the fault current with. The second branch is a gate-turn-off thyristor switch controlled to work in either of two modes. For the main mode, it controls the temperature of the superconducting element and protect it against damaging excessive heating. Instead, it keeps the device applicable without that superconducting element in the auxiliary operation mode. The design, control and operation of the device is addressed. Its performance in 11 kV distribution systems with DG is investigated. The factors affecting the device behavior for different scenarios are explored. (author)

  8. Numerical modeling of transformer inrush currents

    Science.gov (United States)

    Cardelli, E.; Faba, A.

    2014-02-01

    This paper presents an application of a vector hysteresis model to the prediction of the inrush current due the arbitrary initial excitation of a transformer after a fault. The approach proposed seems promising in order to predict the transient overshoot in current and the optimal time to close the circuit after the fault.

  9. Numerical modeling of transformer inrush currents

    Energy Technology Data Exchange (ETDEWEB)

    Cardelli, E. [Department of Industrial Engineering, University of Perugia, I-06125 Perugia (Italy); Center for Electric and Magnetic Applied Research (Italy); Faba, A., E-mail: faba@unipg.it [Department of Industrial Engineering, University of Perugia, I-06125 Perugia (Italy); Center for Electric and Magnetic Applied Research (Italy)

    2014-02-15

    This paper presents an application of a vector hysteresis model to the prediction of the inrush current due the arbitrary initial excitation of a transformer after a fault. The approach proposed seems promising in order to predict the transient overshoot in current and the optimal time to close the circuit after the fault.

  10. European Cohesion Policy: A Proposed Evaluation Model

    Directory of Open Access Journals (Sweden)

    Alina Bouroşu (Costăchescu

    2012-06-01

    Full Text Available The current approach of European Cohesion Policy (ECP is intended to be a bridge between different fields of study, emphasizing the intersection between "the public policy cycle, theories of new institutionalism and the new public management”. ECP can be viewed as a focal point between putting into practice the principles of the new governance theory, theories of economic convergence and divergence and the governance of common goods. After a short introduction of defining the concepts used, the author discussed on the created image of ECP by applying three different theories, focusing on the structural funds implementation system (SFIS, directing the discussion on the evaluation part of this policy, by proposing a model of performance evaluation of the system, in order to outline key principles for creating effective management mechanisms of ECP.

  11. Soft commutated direct current motor [summary of proposed paper

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, John S.

    1998-10-22

    A novel soft commutated direct current (DC) motor is introduced. The current of the commutated coil is intentionally drained before the brush disconnects the coil. This prevents the spark generation that normally occurs in conventional DC motors. A similar principle can be applied for DC generators.

  12. A proposal for B-physics on current lattices

    Energy Technology Data Exchange (ETDEWEB)

    Blossier, B. [Paris 11 Univ., 91 - Orsay (France). Lab. de Physique Theorique; Dimopoulos, P.; Frezzotti, R. [Roma Univ., Tor Vergata (Italy). Dipt. di Fisica; INFN, Roma Tor Vergata (IT)] (and others)

    2009-10-15

    A method to extract B-physics parameters (b-quark mass and f{sub B}, f{sub Bs} decay constants) from currently available lattice data is presented and tested. The approach is based on the idea of constructing appropriate ratios of heavy-light meson masses and decay constants, respectively, possessing a precisely known static limit, and evaluating them at various pairs of heavy quark masses around the charm. Via a smooth interpolation in the heavy quark mass from the easily accessible charm region to the asymptotic point, B-physics parameters are computed with a few percent (statistical + systematic) error using recently produced N{sub f}=2 maximally twisted Wilson fermions data. (orig.)

  13. Nanorobotic Applications in Medicine: Current Proposals and Designs.

    Science.gov (United States)

    Saadeh, Yamaan; Vyas, Dinesh

    2014-06-01

    Advances in technology have increased our ability to manipulate the world around us on an ever-decreasing scale. Nanotechnologies are rapidly emerging within the realm of medicine, and this subfield has been termed nanomedicine. Use of nanoparticle technology has become familiar and increasingly commonplace, especially with pharmaceutical technology. An exciting and promising area of nanotechnological development is the building of nanorobots, which are devices with components manufactured on the nanoscale. This area of study is replete with potential applications, many of which are currently being researched and developed. The goal of this paper is to give an introduction to the emerging field of nanorobotics within medicine, and provide a review of the emerging applications of nanorobotics to fields ranging from neurosurgery to dentistry.

  14. A proposed general model of information behaviour.

    Directory of Open Access Journals (Sweden)

    2003-01-01

    Full Text Available Presents a critical description of Wilson's (1996 global model of information behaviour and proposes major modification on the basis of research into information behaviour of managers, conducted in Poland. The theoretical analysis and research results suggest that Wilson's model has certain imperfections, both in its conceptual content, and in graphical presentation. The model, for example, cannot be used to describe managers' information behaviour, since managers basically are not the end users of external from organization or computerized information services, and they acquire information mainly through various intermediaries. Therefore, the model cannot be considered as a general model, applicable to every category of information users. The proposed new model encompasses the main concepts of Wilson's model, such as: person-in-context, three categories of intervening variables (individual, social and environmental, activating mechanisms, cyclic character of information behaviours, and the adoption of a multidisciplinary approach to explain them. However, the new model introduces several changes. They include: 1. identification of 'context' with the intervening variables; 2. immersion of the chain of information behaviour in the 'context', to indicate that the context variables influence behaviour at all stages of the process (identification of needs, looking for information, processing and using it; 3. stress is put on the fact that the activating mechanisms also can occur at all stages of the information acquisition process; 4. introduction of two basic strategies of looking for information: personally and/or using various intermediaries.

  15. A proposed health model: a step before model confirmation.

    Science.gov (United States)

    Gauff, J F

    1992-01-01

    Health marketers have devoted extensive conceptual and empirical effort toward explaining and predicting individuals' health-related decisions. This paper proposes a health behavior model by combining the health belief model and the theory of planned behavior model. Recent modifications of the Fishbein and Ajzen (1975) model are discussed and an extension is introduced to better explain goal pursuit. These revisions (Bagozzi and Warshaw 1990) are incorporated in the proposed model.

  16. Behavioral modeling of Digitally Adjustable Current Amplifier

    Directory of Open Access Journals (Sweden)

    Josef Polak

    2015-03-01

    Full Text Available This article presents the digitally adjustable current amplifier (DACA and its analog behavioral model (ABM, which is suitable for both ideal and advanced analyses of the function block using DACA as active element. There are four levels of this model, each being suitable for simulation of a certain degree of electronic circuits design (e.g. filters, oscillators, generators. Each model is presented through a schematic wiring in the simulation program OrCAD, including a description of equations representing specific functions in the given level of the simulation model. The design of individual levels is always verified using PSpice simulations. The ABM model has been developed based on practically measured values of a number of DACA amplifier samples. The simulation results for proposed levels of the ABM model are shown and compared with the results of the real easurements of the active element DACA.

  17. Media Accountability Systems: Models, proposals and outlooks

    Directory of Open Access Journals (Sweden)

    Luiz Martins da Silva

    2007-06-01

    Full Text Available This paper analyzes one of the basic actions of SOS-Imprensa, the mechanism to assure Media Accountability with the goal of proposing a synthesis of models for the Brazilian reality. The article aims to address the possibilities of creating and improving mechanisms to stimulate the democratic press process and to mark out and assure freedom of speech and personal rights with respect to the media. Based on the Press Social Responsibility Theory, the hypothesis is that the experiences analyzed (Communication Council, Press Council, Ombudsman and Readers Council are alternatives for accountability, mediation and arbitration, seeking visibility, trust and public support in favor of fairer media.

  18. Proposal of Enhanced Extreme Programming Model

    Directory of Open Access Journals (Sweden)

    M. Rizwan Jameel Qureshi

    2015-01-01

    Full Text Available Extreme programming is one of the commonly used agile methodologies in software development. It is very responsive to changing requirements even in the late phases of the project. However, quality activities in extreme programming phases are implemented sequentially along with the activities that work on the functional requirements. This reduces the agility to deliver increments continuously and makes an inverse relationship between quality and agility. Due to this relationship, extreme programming does not consume enough time on making extensive documentation and robust design. To overcome these issues, an enhanced extreme programming model is proposed. Enhanced extreme programming introduces parallelism in the activities' execution through putting quality activities into a separate execution line. In this way, the focus on delivering increments quickly is achieved without affecting the quality of the final output. In enhanced extreme programming, the quality concept is extended to include refinement of all phases of classical extreme programming and creating architectural design based on the refined design documents.

  19. Multinucleon Ejection Model for Two Body Current Neutrino Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Sobczyk, Jan T.; /Fermilab

    2012-06-01

    A model is proposed to describe nucleons ejected from a nucleus as a result of two-body-current neutrino interactions. The model can be easily implemented in Monte Carlo neutrino event generators. Various possibilities to measure the two-body-current contribution are discussed. The model can help identify genuine charge current quasielastic events and allow for a better determination of the systematic error on neutrino energy reconstruction in neutrino oscillation experiments.

  20. A Proposed Supergrid Model for National Transmission Network of Pakistan

    Directory of Open Access Journals (Sweden)

    FAHEEM AKHTER

    2017-01-01

    Full Text Available Pakistan is facing a severe energy crisis of its time with significant generation deficit in recent years. The future plan shows hydro and thermal coal generation as major contributor and Wind power to replace Thermal-oil generation in long run. This paper proposes a Super grid model for the transfer of bulk power from generation station to the load centres, which can provide efficient transmission between generation and load centres and is also adaptive to deal with variations in power from renewable generations. A dynamic simulation analysis is performed on six-terminal MTDC (Multi-Terminal High Voltage Direct Current system VSC (Voltage Source Converter based MTDC meshed grid with different control operations. The results show that the proposed super grid model can provide efficient transmission between generation and load centres and it is also adaptive to deal with variation in power from renewable generation.

  1. Regional economic effects of current and proposed management alternatives for Sand Lake National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report first provides a description of the local community and economy near Sand Lake NWR. An analysis of current and proposed management strategies that could...

  2. Current Challenges in Dynamo Modeling

    Science.gov (United States)

    Glatzmaier, G. A.

    2001-12-01

    Three-dimensional, dynamically self-consistent, numerical simulations have been used for two decades to study the generation of global magnetic fields in the deep fluid interiors of planets and stars. In particular, the number of geodynamo models has increased significantly within the last five years. These simulations of magnetic field generation by laminar convection have provided considerable insight to the dynamo process and have produced large-scale fields similar to those observed. However, no global convective dynamo simulation has yet been able to afford the spatial resolution required to simulate turbulent convection, which surely must exist in these low-viscosity fluids. They have all employed greatly enhanced eddy diffusivities to stabilize the low resolution numerical solutions and crudely account for the transport and mixing by the unresolved turbulence. A grand challenge for the next generation of geodynamo models is to produce a simulation with the thermal and viscous (eddy) diffusivities set no larger than the actual magnetic diffusivity of the Earth's fluid core (2 m2/s), while using the core's dimensions, mass, rotation rate and heat flow. This would correspond to the Ekman and magnetic Ekman numbers both set to 10-9 and the Rayleigh number being many orders of magnitude greater than critical. Dynamo models for stars and planets present an additional complication: the large variation of density with radius. A grand challenge for the next generation of these models is to reach similarly low Ekman numbers and high Rayleigh numbers with a density that decreases by at least three orders of magnitude from the base of the convection zone to the model's outer boundary. The advances in numerical methods and massively parallel computing needed to meet these challenges will be discussed.

  3. 78 FR 54622 - Proposed Information Collection; Comment Request; Current Population Survey, Annual Social and...

    Science.gov (United States)

    2013-09-05

    ... Census Bureau Proposed Information Collection; Comment Request; Current Population Survey, Annual Social... concerning the Annual Social and Economic Supplement (ASEC) to be conducted in conjunction with the February, March, and April Current Population Survey (CPS). The Census Bureau has conducted this...

  4. Paralegals in Corrections: A Proposed Model.

    Science.gov (United States)

    McShane, Marilyn D.

    1987-01-01

    Describes the legal assistance program currently offered by the Texas Department of Corrections which demonstrates the wide range of questions and problems that the paralegal can address. Reviews paralegal's functions in the prison setting and the services they can provide in assisting prisoners to maintain their rights. (Author/ABB)

  5. Child-Labor Proposal Eyes Private Model

    Science.gov (United States)

    Cech, Scott J.

    2007-01-01

    Proposed child-labor-rule changes--the most ambitious in 30 years--would carve out a permanent exemption to U.S. Department of Labor regulations for the work-study program run by a national network of Roman Catholic high schools. The program is a requirement of the Chicago-based Cristo Rey Network, which now has 12 high schools around the country…

  6. Child-Labor Proposal Eyes Private Model

    Science.gov (United States)

    Cech, Scott J.

    2007-01-01

    Proposed child-labor-rule changes--the most ambitious in 30 years--would carve out a permanent exemption to U.S. Department of Labor regulations for the work-study program run by a national network of Roman Catholic high schools. The program is a requirement of the Chicago-based Cristo Rey Network, which now has 12 high schools around the country…

  7. The Associative Basis of Scientific Creativity: A Model Proposal

    Directory of Open Access Journals (Sweden)

    Esra Kanli

    2014-06-01

    Full Text Available Creativity is accepted as an important part of scientific skills. Scientific creativity proceeds from a need or urge to solve a problem, and in-volves the production of original and useful ideas or products. Existing scientific creativity theories and tests do not feature the very im-portant thinking processes, such as analogical and associative thinking, which can be consid-ered crucial in creative scientific problem solv-ing. Current study’s aim is to provide an alter-native model and explicate the associative basis of scientific creativity. Emerging from the re-viewed theoretical framework, Scientific Asso-ciations Model is proposed. This model claims that, similarity and mediation constitutes the basis of creativity and focuses on three compo-nents namely; associative thinking, analogical thinking (analogical reasoning & analogical problem solving and insight which are consid-ered to be main elements of scientific associa-tive thinking.

  8. Proposal: A Hybrid Dictionary Modelling Approach for Malay Tweet Normalization

    Science.gov (United States)

    Muhamad, Nor Azlizawati Binti; Idris, Norisma; Arshi Saloot, Mohammad

    2017-02-01

    Malay Twitter message presents a special deviation from the original language. Malay Tweet widely used currently by Twitter users, especially at Malaya archipelago. Thus, it is important to make a normalization system which can translated Malay Tweet language into the standard Malay language. Some researchers have conducted in natural language processing which mainly focuses on normalizing English Twitter messages, while few studies have been done for normalize Malay Tweets. This paper proposes an approach to normalize Malay Twitter messages based on hybrid dictionary modelling methods. This approach normalizes noisy Malay twitter messages such as colloquially language, novel words, and interjections into standard Malay language. This research will be used Language Model and N-grams model.

  9. Vaccination adherence: Review and proposed model.

    Science.gov (United States)

    Abahussin, Asma A; Albarrak, Ahmed I

    The prevalence of childhood vaccine-preventable diseases can be significantly reduced through adherence to confirmed vaccination schedules. However, many barriers to vaccination compliance exist, including a lack of awareness regarding the importance of vaccines, missing due dates, and fear of complications from vaccinations. The aim of this study is to review the existing tools and publications regarding vaccination adherence, and to propose a design for a vaccination adherence application (app) for smartphones. Android and iOS apps designed for vaccination reminders have been reviewed to examine six elements: educational factor; customizing features; reminder tools; peer education facilitations; feedback, and the language of apps' interface and content. The literature from PubMed has been reviewed for studies addressing reminder systems or tools including apps. The study has revealed insufficient (n=6) technology-based interventions for increasing childhood vaccination rates by reminding parents in comparison to the fast growth in technology, out of which are two publications discussed mobile apps. Ten apps have been found in apps stores; only one out of them was designed for the Saudi vaccination schedule in Arabic language with some weaknesses. The study proposed a design for a vaccination reminder app that includes a number of features in order to overcome the limitations discussed in the studied reminders, apps, and systems. The design supports the Arabic language and the Saudi vaccination schedule; parental education including peer education; a variety of reminder methods, and the capability to track vaccinations and refer to the app as a personal health record. The study discussed a design for a vaccination reminder app that satisfies the specific requirements for better compliance to children's immunization schedules based on reviewing the existing apps and publications. The proposed design includes element to educate parents and answer their concerns

  10. A proposed model for construction project management ...

    African Journals Online (AJOL)

    The lack of a proper communication skills model for project management may ... done to identify the most important project management communication skills and applications of communication that effective project managers should possess.

  11. Proposed Methodology for Generation of Building Information Model with Laserscanning

    Institute of Scientific and Technical Information of China (English)

    Shutao Li; J(o)rg lsele; Georg Bretthauer

    2008-01-01

    For refurbishment and state review of an existing old building,a new model reflecting the current state is often required especially when the original plans are no longer accessible.Laser scanners are used more and more as surveying instruments for various applications because of their high-precision scanning abilities.For buildings,the most notable and widely accepted product data model is the IFC product data model.It is designed to cover the whole lifecycle and supported by various software vendors and enables applications to efficiently share and exchange project information.The models obtained with the laser scan-ner,normally sets of points ("point cloud"),have to be transferred to an IFC compatible building information model to serve the needs of different planning states.This paper presents an approach designed by the German Research Center in Karlsmhe (Forschungszentrum Kadsmhe) to create an IFC compatible building information model from laser range images.The methodology through the entire process from data acquisi tion to the IFC compatible product model was proposed in this paper.In addition,IFC-Models with different level of detail (LoDs) were introduced and discussed within the work.

  12. Modeling of Current Transformers Under Saturation Conditions

    Directory of Open Access Journals (Sweden)

    Martin Prochazka

    2006-01-01

    Full Text Available During a short circuit the input signal of the relay can be distort by the magnetic core saturation of the current transformer. It is useful to verify the behavior of CT by a mathematical model. The paper describes one phase and three phase models and it presents some methods of how to analyze and classify a deformed secondary current

  13. Proposal and Development of a High Voltage Variable Frequency Alternating Current Power System for Hybrid Electric Aircraft

    Science.gov (United States)

    Sadey, David J.; Taylor, Linda M.; Beach, Raymond F.

    2017-01-01

    The development of ultra-efficient commercial vehicles and the transition to low-carbon emission propulsion are seen as strategic thrust paths within NASA Aeronautics. A critical enabler to these paths comes in the form of hybrid electric propulsion systems. For megawatt-class systems, the best power system topology for these hybrid electric propulsion systems is debatable. Current proposals within NASA and the Aero community suggest using a combination of alternating current (AC) and direct current (DC) for power generation, transmission, and distribution. This paper proposes an alternative to the current thought model through the use of a primarily high voltage AC power system, supported by the Convergent Aeronautics Solutions (CAS) Project. This system relies heavily on the use of doubly-fed induction machines (DFIMs), which provide high power densities, minimal power conversion, and variable speed operation. The paper presents background on the activity along with the system architecture, development status, and preliminary results.

  14. Analogue Behavioral Modeling of Switched-Current Building Block Circuits

    Institute of Scientific and Technical Information of China (English)

    ZENG Xuan; WANG Wei; SHI Jianlei; TANG Pushan; D.ZHOU

    2001-01-01

    This paper proposes a behavioral modeling technique for the second-generation switched-current building block circuits. The proposed models are capable of capturing the non-ideal behavior of switched-current circuits, which includes the charge injection effects and device mismatch effects. As a result, system performance degradations due to the building block imperfections can be detected at the early design stage by fast behavioral simulations. To evaluate the accuracy of the proposed models, we developed a time-domain behavioral simulator. Experimental results have shown that compared with SPICE, the behavioral modeling error is less than 2.15%, while behavioral simulation speed up is 4 orders in time-domain.

  15. 78 FR 45910 - Proposed Information Collection; Comment Request; Current Population Survey (CPS) Email Address...

    Science.gov (United States)

    2013-07-30

    ... Census Bureau Proposed Information Collection; Comment Request; Current Population Survey (CPS) Email... concerning the November 2013 Email Address Collection Test Supplement. The Census Bureau and the Bureau of.... We foresee that in the future, we could collect email addresses from our respondents. For those that...

  16. Principles of the Proposed Czech Postal Sector Price Control Model

    Directory of Open Access Journals (Sweden)

    Libor Švadlenka

    2009-01-01

    Full Text Available The paper deals with the postal sector control. It resultsfrom the control theory and proves the justifiability of control inthe postal sector. Within the price control it results from E U Directive97!67/EC requirements on this control and states individualtypes of price control focusing on ineffective price controlcurrently used in the Czech postal sector (especially withindomestic services and proposes a more effective method ofprice control. The paper also discusses the principles of the proposedmethod of price control of the Czech postal sector. It describesconcrete fulfilment of the price control model resultingfrom the price-cap and tariff formula RP I-X and concentrateson its quantitative expression. The application of the proposedmodel is carried out for a hypothetical period in the past (in orderto compare it with the current control system for letteritems tariff basket.

  17. Proposed chiral texture of the magnetic moments of unit-cell loop currents in the pseudogap phase of cuprate superconductors.

    Science.gov (United States)

    Pershoguba, Sergey S; Kechedzhi, Kostyantyn; Yakovenko, Victor M

    2013-07-26

    We propose a novel chiral order parameter to explain the unusual polar Kerr effect in underdoped cuprates. It is based on the loop-current model by Varma, which is characterized by the in-plane anapole moment N and exhibits the magnetoelectric effect. We propose a helical structure where the vector N(n) in the layer n is twisted by the angle π/2 relative to N(n-1), thus breaking inversion symmetry. We show that coupling between magnetoelectric terms in the neighboring layers for this structure produces optical gyrotropy, which results in circular dichroism and the polar Kerr effect.

  18. Current approaches to gene regulatory network modelling

    Directory of Open Access Journals (Sweden)

    Brazma Alvis

    2007-09-01

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

  19. Proposal of a four-dimensional model of social response.

    Science.gov (United States)

    Nail, P R; MacDonald, G; Levy, D A

    2000-05-01

    Descriptive models of social response attempt to identify the conceptual dimensions necessary to define and distinguish various types of influence. Building on previous approaches, the authors propose a new response model and demonstrate that a minimum of 4 dimensions is necessary to adequately provide for such influence phenomena as conformity, minority influence, compliance, contagion, independence, and anticonformity in a single model. In addition, the proposed model suggests 5 potential types of response that have not been previously identified. These new types suggest directions for future research and theoretical development. Selected empirical evidence is reviewed in support of the validity and integrative power of the proposed model.

  20. Estimates of current debris from flux models

    Energy Technology Data Exchange (ETDEWEB)

    Canavan, G.H.

    1997-01-01

    Flux models that balance accuracy and simplicity are used to predict the growth of space debris to the present. Known and projected launch rates, decay models, and numerical integrations are used to predict distributions that closely resemble the current catalog-particularly in the regions containing most of the debris.

  1. Behavioral modeling of Digitally Adjustable Current Amplifier

    OpenAIRE

    Josef Polak; Lukas Langhammer; Jan Jerabek

    2015-01-01

    This article presents the digitally adjustable current amplifier (DACA) and its analog behavioral model (ABM), which is suitable for both ideal and advanced analyses of the function block using DACA as active element. There are four levels of this model, each being suitable for simulation of a certain degree of electronic circuits design (e.g. filters, oscillators, generators). Each model is presented through a schematic wiring in the simulation program OrCAD, including a description of equat...

  2. A New Authorization for Use of Military Force Against the Islamic State: Issues and Current Proposals

    Science.gov (United States)

    2017-02-21

    A New Authorization for Use of Military Force Against the Islamic State: Issues and Current Proposals Matthew C. Weed Specialist in Foreign...Policy Legislation February 21, 2017 Congressional Research Service 7-5700 www.crs.gov R43760 A New Authorization for Use of Military Force...Against the Islamic State Congressional Research Service Summary Since the United States embarked on a strategy to counter the Islamic State (also

  3. Simulation of Gravity Currents Using VOF Model

    Institute of Scientific and Technical Information of China (English)

    邹建锋; 黄钰期; 应新亚; 任安禄

    2002-01-01

    By the Volume of Fluid (VOF) multiphase flow model two-dimensional gravity currents with three phases including air are numerically simulated in this article. The necessity of consideration of turbulence effect for high Reynolds numbers is demonstrated quantitatively by LES (the Large Eddy Simulation) turbulence model. The gravity currents are simulated for h ≠ H as well as h = H, where h is the depth of the gravity current before the release and H is the depth of the intruded fluid. Uprising of swell occurs when a current flows horizontally into another lighter one for h ≠ H. The problems under what condition the uprising of swell occurs and how long it takes are considered in this article. All the simulated results are in reasonable agreement with the experimental results available.

  4. Current status: Animal models of nausea

    Science.gov (United States)

    Fox, Robert A.

    1991-01-01

    The advantages, and possible benefits of a valid, reliable animal model for nausea are discussed, and difficulties inherent to the development of a model are considered. A principle problem for developing models arises because nausea is a subjective sensation that can be identified only in humans. Several putative measures of nausea in animals are considered, with more detailed consideration directed to variation in cardiac rate, levels of vasopressin, and conditioned taste aversion. Demonstration that putative measures are associated with reported nausea in humans is proposed as a requirement for validating measures to be used in animal models. The necessity for a 'real-time' measure of nausea is proposed as an important factor for future research; and the need for improved understanding of the neuroanatomy underlying the emetic syndrome is discussed.

  5. Passive Target Tracking Based on Current Statistical Model

    Institute of Scientific and Technical Information of China (English)

    DENG Xiao-long; XIE Jian-ying; YANG Yu-pu

    2005-01-01

    Bearing-only passive tracking is regarded as a nonlinear hard tracking problem. There are still no completely good solutions to this problem until now. Based on current statistical model, the novel solution to this problem utilizing particle filter (PF) and the unscented Kalman filter (UKF) is proposed. The new solution adopts data fusion from two observers to increase the observability of passive tracking. It applies the residual resampling step to reduce the degeneracy of PF and it introduces the Markov Chain Monte Carlo methods (MCMC) to reduce the effect of the "sample impoverish". Based on current statistical model, the EKF, the UKF and particle filter with various proposal distributions are compared in the passive tracking experiments with two observers. The simulation results demonstrate the good performance of the proposed new filtering methods with the novel techniques.

  6. Proposal of rectifier type superconducting fault current limiter with non-inductive reactor (SFCL)

    Science.gov (United States)

    Mohammad Salim, Khosru; Muta, Itsuya; Hoshino, Tsutomu; Nakamura, Taketsune; Yamada, Masato

    2004-03-01

    A rectifier type superconducting fault current limiter (SFCL) with non-inductive reactor has been proposed. The concept behind this SFCL is the appearance of high impedance during non-superconducting state of the coil. In a hybrid bridge circuit, two superconducting coils connected in anti-parallel: a trigger coil and a limiting coil. Both the coils are magnetically coupled with each other and have same number of turns. There is almost zero flux inside the core and therefore the total inductance is small during normal operation. At fault time when the trigger coil current reaches to a certain level, the trigger coil changes from superconducting state to normal state. This super-to-normal transition of the trigger coil changes the current ratio of the coils and therefore the flux inside the reactor is no longer zero. So, the equivalent impedance of both the coils increased thus limits the fault current. We have carried out computer simulation using EMTDC and observed the results. A preliminary experiment has already been performed using copper wired reactor with simulated super-to-normal transition resistance and magnetic switches. Both the simulation and preliminary experiment shows good results. The advantage of using hybrid bridge circuit is that the SFCL can also be used as circuit breaker. Two separate bridge circuit can be used for both trigger coil and the limiter coil. In such a case, the trigger coil can be shutdown immediately after the fault to reduce heat and thus reduce the recovery time. Again, at the end of fault when the SFCL needs to re-enter to the grid, turning off the trigger circuit in the two-bridge configuration the inrush current can be reduced. This is because the current only flows through the limiting coil. Another advantage of this type of SFCL is that no voltage sag will appear during load increasing time as long as the load current stays below the trigger current level.

  7. Conservation assessment of current and proposed nature reserves of Tamaulipas state, Mexico

    Science.gov (United States)

    Cantu, C.; Gerald, Wright R.; Michael, Scott J.; Strand, Espen

    2003-01-01

    The Mexican state of Tamaulipas located in the northeastern portion of the country currently has five state nature reserves covering slightly less than 3% of its land area. These reserves were established for a variety of reasons, many unrelated to the protection of biological resources. In 2000 in response to a growing concern about the lack of organized conservation reserve planning to protect the important biological and physical features of Mexico, the Mexican Commission for Knowledge and Use of Biodiversity (CONABIO) proposed 13 new terrestrial reserves for Tamaulipas. If established these new reserves would increase the proportion of terrestrial protected lands in the state to over 21%. We compiled a geographic information system (GIS) using existing digital thematic maps of physical and biological features to examine how the existing and proposed reserves might serve to protect the biodiversity and physical features of the state. We found that most of the existing protected sites occur in areas with elevations > 1000-2000 m with temperate climate and dominated by pine forest, oak forest, and cloud forest vegetation cover types. The state's dominant biotic region - low elevation coastal plain with tropical and arid climate types and xeric scrub vegetation - is disproportionately underrepresented in the current reserve system. The creation of the proposed areas would substantially increase the protection of mid and high elevation lands. The largest gap in the protected lands network would be low elevation, level, coastal lands.

  8. Developmental trauma, complex PTSD, and the current proposal of DSM-5

    Directory of Open Access Journals (Sweden)

    Vedat Sar

    2011-03-01

    Full Text Available This paper evaluates representation of clinical consequences of developmental psychological trauma in the current proposal of DSM-5. Despite intensive efforts by its proponents for two decades, it is not known yet if Complex PTSD will take a place in the final version of DSM-5. Recognition of dissociative character of several symptom dimensions and introduction of items about negative affects such as shame and guilt imply an indirect improvement toward better coverage of the consequences of developmental trauma in the existing category of PTSD. As disorders with highest prevalence of chronic traumatization in early years of life, dissociative disorders and personality disorder of borderline type are maintained as DSM-5 categories; however, recognition of a separate type of trauma-related personality disorder is unlikely. While a preschooler age variant of PTSD is under consideration, the proposed diagnosis of Developmental Trauma Disorder (child version of Complex PTSD has not secured a place in the DSM-5 yet. We welcome considerations of subsuming Adjustment Disorders, Acute Stress Disorder, PTSD, and Dissociative Disorders under one rubric, i.e., Section of Trauma, Stress, or Event Related Disorders. Given the current conceptualization of DSM-5, this paper proposes Complex PTSD to be a subtype of the DSM-5 PTSD. Composition of a trauma-related disorders section would facilitate integration of knowledge and expertise about interrelated and overlapping consequences of trauma.For the abstract or full text in other languages, please see Supplementary files under Reading Tools online

  9. Developmental trauma, complex PTSD, and the current proposal of DSM-5.

    Science.gov (United States)

    Sar, Vedat

    2011-01-01

    This paper evaluates representation of clinical consequences of developmental psychological trauma in the current proposal of DSM-5. Despite intensive efforts by its proponents for two decades, it is not known yet if Complex PTSD will take a place in the final version of DSM-5. Recognition of dissociative character of several symptom dimensions and introduction of items about negative affects such as shame and guilt imply an indirect improvement toward better coverage of the consequences of developmental trauma in the existing category of PTSD. As disorders with highest prevalence of chronic traumatization in early years of life, dissociative disorders and personality disorder of borderline type are maintained as DSM-5 categories; however, recognition of a separate type of trauma-related personality disorder is unlikely. While a preschooler age variant of PTSD is under consideration, the proposed diagnosis of Developmental Trauma Disorder (child version of Complex PTSD) has not secured a place in the DSM-5 yet. We welcome considerations of subsuming Adjustment Disorders, Acute Stress Disorder, PTSD, and Dissociative Disorders under one rubric, i.e., Section of Trauma, Stress, or Event Related Disorders. Given the current conceptualization of DSM-5, this paper proposes Complex PTSD to be a subtype of the DSM-5 PTSD. Composition of a trauma-related disorders section would facilitate integration of knowledge and expertise about interrelated and overlapping consequences of trauma.

  10. Flavor Changing Neutral Currents in a Realistic Composite Technicolor Model

    CERN Document Server

    Carone, C D; Carone, Christopher D.; Hamilton, Rowan T.

    1993-01-01

    We consider the phenomenology of a composite technicolor model proposed recently by Georgi. Composite technicolor interactions produce four-quark operators in the low energy theory that contribute to flavor changing neutral current processes. While we expect operators of this type to be induced at the compositeness scale by the flavor-symmetry breaking effects of the preon mass matrices, the Georgi model also includes operators from higher scales that are not GIM-suppressed. Since these operators are potentially large, we study their impact on flavor changing neutral currents and CP violation in the neutral $B$, $D$, and $K$ meson systems.

  11. Exploring Distance Learning Environments: A Proposal for Model Categorization.

    Science.gov (United States)

    Morgado, Eduardo Martins; Yonezawa, Wilson; Reinhard, Nicolau

    This article proposes a categorization model for online distance education environments, based on two different aspects: interaction and content. The proposed categorization, which was based on the experience acquired in developing, implementing, and operating different remote training courses, is aimed at providing evidence to help educational…

  12. Current practices and reform proposals for the regulation of advanced medicinal products in Canada.

    Science.gov (United States)

    Viswanathan, Sowmya; Bubela, Tania

    2015-01-01

    We describe the Canadian regulatory framework for evaluating advanced medicinal products based on current policies, guidance documents and regulations and analyze proposed reforms. Our analysis is based on a documentary review supplemented by discussions with Health Canada officials. We present an overview of the Canadian regulatory framework for cell and gene therapy, medical devices and manufacturing facilities. We use the approval of Prochymal™ to highlight Canada's conditional marketing approval system. Finally, we discuss proposed changes to the regulatory framework in response to identified gaps, stakeholder consultations and international harmonization initiatives. Based on our analyses, we suggest that Canadian regulators have taken a reasonable approach in applying their regulatory framework without compromising on product safety.

  13. Cyber Capability Development Centre (CCDC): Proposed Governance Model

    Science.gov (United States)

    2013-12-01

    Canada. Contract Report DRDC-RDDC-2014-C170 December 2013 Cyber Capability Development Centre ( CCDC ) Proposed governance model Douglas...13 ii Table of Figures Figure 1: CCDC organization and infrastructure

  14. Regional economic effects of current and proposed management alternatives for Arrowwood National Wildlife Refuge

    Science.gov (United States)

    Koontz, Lynne; Lambert, Heather

    2005-01-01

    The National Wildlife Refuge System Improvement Act of 1997 requires all units of the National Wildlife Refuge System to be managed under a Comprehensive Conservation Plan (CCP). The CCP must describe the desired future conditions of a Refuge and provide long range guidance and management direction to achieve Refuge purposes. Arrowwood National Wildlife Refuge (NWR), located along the James River in east central North Dakota, is in the process of developing a range of management goals, objectives, and strategies for the CCP. The CCP for Arrowwood NWR must contain an analysis of expected effects associated with current and proposed Refuge management strategies.

  15. Regional economic effects of current and proposed management alternatives for Sand Lake National Wildlife Refuge

    Science.gov (United States)

    Koontz, Lynne; Lambert, Heather

    2005-01-01

    The National Wildlife Refuge System Improvement Act of 1997 requires all units of the National Wildlife Refuge System to be managed under a Comprehensive Conservation Plan (CCP). The CCP must describe the desired future conditions of a Refuge and provide long range guidance and management direction to achieve Refuge purposes. Sand Lake National Wildlife Refuge (NWR), located 27 miles northeast of Aberdeen, South Dakota, is in the process of developing a range of management goals, objectives, and strategies for the CCP. The CCP for Sand Lake NWR must contain an analysis of expected effects associated with current and proposed Refuge management strategies.

  16. Pricing Data: A Look at Past Proposals, Current Plans, and Future Trends

    CERN Document Server

    Sen, Soumya; Ha, Sangtae; Chiang, Mung

    2012-01-01

    Traditionally, network operators have only used simple flat-rate unlimited data plans to vie for customers. But today, with the popularity of mobile devices and exponential growth of apps, videos, and clouds, service providers are gradually moving towards more sophisticated pricing schemes, including dynamic pricing. This decade will therefore likely witness a major shift in network pricing schemes. However, there are several unique challenges with the dynamic pricing of mobile data, including new system requirements and social adoption. This paper reviews some of the well known past pricing proposals (both static and dynamic), their current realization in various data plans, and new research directions. Unlike a traditional survey, this work is an attempt to explore benefits and challenges of pricing plans that are currently being used by ISPs in different parts of the world so as to facilitate the networking community's efforts in recognizing trends and shaping an appropriate research agenda.

  17. Proposal of New PRORISK Model for GSD Projects

    Directory of Open Access Journals (Sweden)

    M. Rizwan Jameel Qureshi

    2015-05-01

    Full Text Available The level of complexity and risks associated with software are increasing exponentially because of competing environment especially in geographically distributed projects. Global software development (GSD face challenges like distance, communication and coordination challenges. The coordination and communication challenges are the main causes of failure in GSD. Project Oriented Risk Management (PRORISK is one of the models to address the importance of risk management and project management processes in standard software projects. However, existing model is not proposed to handle GSD associated risks. This warrants the proposal of new PRORISK model to manage the risks of GSD. Survey is used as a research design to validate the proposed solution. We anticipate that the proposed solution will help the software companies to cater the risks associated with GSD.

  18. Proposed high voltage power supply for the ITER relevant lower hybrid current drive system

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, P.K., E-mail: pramod@ipr.res.in [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat (India); Kazarian, F.; Garibaldi, P.; Gassman, T. [ITER Organization, CS 90 046, 13067 Saint-Paul-Les-Durance (France); Artaud, J.F. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Bae, Y.S. [National Fusion Research Institute, Daejeon (Korea, Republic of); Belo, J. [Associacao Euratom-IST, Centro de Fusao Nuclear, Lisboa (Portugal); Berger-By, G.; Bernard, J.M.; Cara, Ph. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Cardinali, A.; Castaldo, C.; Ceccuzzi, S.; Cesario, R. [Associazione Euratom-ENEA sulla Fusione, CR Frascati, Rome (Italy); Decker, J.; Delpech, L.; Ekedahl, A.; Garcia, J.; Goniche, M.; Guilhem, D. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France)

    2011-10-15

    In the framework of the EFDA task HCD-08-03-01, the ITER lower hybrid current drive (LHCD) system design has been reviewed. The system aims to generate 24 MW of RF power at 5 GHz, of which 20 MW would be coupled to the plasmas. The present state of the art does not allow envisaging a unitary output of the klystrons exceeding 500 kW, so the project is based on 48 klystron units, leaving some margin when the transmission lines losses are taken into account. A high voltage power supply (HVPS), required to operate the klystrons, is proposed. A single HVPS would be used to feed and operate four klystrons in parallel configuration. Based on the above considerations, it is proposed to design and develop twelve HVPS, based on pulse step modulator (PSM) technology, each rated for 90 kV/90 A. This paper describes in details, the typical electrical requirements and the conceptual design of the proposed HVPS for the ITER LHCD system.

  19. Instructor’s Performance: A Proposed Model for Online Evaluation

    Directory of Open Access Journals (Sweden)

    Salah Alkhafaji

    2013-10-01

    Full Text Available Currently due to high awareness and quality audits, the higher education institutions have made to keep a track on various performances of the institutions. One such most important activity that has to be analyzed and evaluated is Instructor’s classroom performance. As the students are the main stakeholders of the educational process, their concerns over the instructor, teaching pedagogies and methodologies, assessment techniques need to be collected and analyzed for achieving the institution’s goals and objectives. The students shall give their opinions related to the various performance indicators of instructor.In general, the higher education institutions use various techniques to evaluate instructor’s performance in the classroom from the students. The latest technological developments help in data collection using web technologies. Online system with required questionnaire and attributes will help the higher education institutions in easy data collection. Apart from that the students shall give their opinions without any fear from any place and at any time. In this paper, we have identified the major factors and users of an instructor online evaluation system. Also, we have proposed a model for such system with subsystem interface, entity relationship diagram and context diagram.

  20. Human sperm chromatin stabilization: a proposed model including zinc bridges.

    Science.gov (United States)

    Björndahl, Lars; Kvist, Ulrik

    2010-01-01

    The primary focus of this review is to challenge the current concepts on sperm chromatin stability. The observations (i) that zinc depletion at ejaculation allows a rapid and total sperm chromatin decondensation without the addition of exogenous disulfide cleaving agents and (ii) that the human sperm chromatin contains one zinc for every protamine for every turn of the DNA helix suggest an alternative model for sperm chromatin structure may be plausible. An alternative model is therefore proposed, that the human spermatozoon could at ejaculation have a rapidly reversible zinc dependent chromatin stability: Zn(2+) stabilizes the structure and prevents the formation of excess disulfide bridges by a single mechanism, the formation of zinc bridges with protamine thiols of cysteine and potentially imidazole groups of histidine. Extraction of zinc enables two biologically totally different outcomes: immediate decondensation if chromatin fibers are concomitantly induced to repel (e.g. by phosphorylation in the ooplasm); otherwise freed thiols become committed into disulfide bridges creating a superstabilized chromatin. Spermatozoa in the zinc rich prostatic fluid (normally the first expelled ejaculate fraction) represent the physiological situation. Extraction of chromatin zinc can be accomplished by the seminal vesicular fluid. Collection of the ejaculate in one single container causes abnormal contact between spermatozoa and seminal vesicular fluid affecting the sperm chromatin stability. There are men in infertile couples with low content of sperm chromatin zinc due to loss of zinc during ejaculation and liquefaction. Tests for sperm DNA integrity may give false negative results due to decreased access for the assay to the DNA in superstabilized chromatin.

  1. Flavor changing neutral currents in a realistic composite technicolor model

    Science.gov (United States)

    Carone, Christopher D.; Hamilton, Rowan T.

    1993-03-01

    We consider the phenomenology of a composite technicolor model proposed recently by Georgi. Composite technicolor interactions produce four-quark operators in the low energy theory that contribute to flavor changing neutral current processes. While we expect operators of this type to be induced at the compositeness scale by the flavor-symmetry breaking effects of the preon mass matrices, the Georgi model also includes operators from higher scales that are not GIM-suppressed. Since these operators are potentially large, we study their impact on flavor changing neutral currents and CP violation in the neutral K, B, and D meson systems. Notably, we find that this model gives rise to a typical value for {ɛ‧}/{ɛ} that is much smaller than most standard model estimates.

  2. Proposal for product development model focused on ce certification methodology

    Directory of Open Access Journals (Sweden)

    Nathalia Marcia Goulart Pinheiro

    2015-09-01

    Full Text Available This paper presents a critical analysis comparing 21 product development models in order to identify whether these structures meet the demands Product Certification of the European Community (CE. Furthermore, it presents a product development model, comprising the steps in the models analyzed, including improvements in activities for referred product certification. The proposed improvements are justified by the growing quest for the internationalization of products and processes within companies.

  3. Proposal Of Landfill Site Model In The Particular Territory

    Directory of Open Access Journals (Sweden)

    Stopka Ondrej

    2015-12-01

    Full Text Available Nowadays, waste logistics is a relevant element within the worldwide logistics system. This paper is focused on the proposal of the appropriate model of landfill site for disposal of municipal waste. This issue refers to waste logistics in urban areas. In this regard, three different alternative models of landfill sites are considered. Landfill site model can significantly influence the waste management productivity and effectiveness of the enterprise. In the paper, one of the decision-making problem methods is utilized. This particular method enables to assess each model of landfill site in relation to each of the specified criterion and order the models according to the achieved results.

  4. Regional economic impacts of current and proposed management alternatives for Charles M. Russell National Wildlife Refuge

    Science.gov (United States)

    Koontz, Lynne; Sexton, Natalie; Ishizaki, Asuka; Ritten, John

    2013-01-01

    The National Wildlife Refuge System Improvement Act of 1997 requires all units of the National Wildlife Refuge System to be managed under a Comprehensive Conservation Plan (CCP). The CCP must describe the desired future conditions of a refuge and provide long-range guidance and management direction to achieve refuge purposes. Charles M. Russell (CMR) National Wildlife Refuge, located in north-central Montana, is in the process of developing a range of management goals, objectives, and strategies for the CCP. The CCP for the Refuge must contain an analysis of expected effects associated with current and proposed refuge-management strategies. For refuge CCP planning, an economic analysis provides a means of estimating how current management (No Action Alternative) and proposed management activities (Alternatives) affect the local economy. This type of analysis provides two critical pieces of information: (1) it illustrates a refuge’s contribution to the local community; and (2) it can help in determining whether economic effects are or are not a real concern in choosing among management alternatives. It is important to note that the economic value of a refuge encompasses more than just the impacts on the regional economy. Refuges also provide substantial nonmarket values (values for items not exchanged in established markets) such as maintaining endangered species, preserving wetlands, educating future generations, and adding stability to the ecosystem (Carver and Caudill, 2007). However, quantifying these types of nonmarket values is beyond the scope of this study. This report first presents a description of the local community and economy near the Refuge. Next, the methods used to conduct a regional economic impact analysis are described. An analysis of the final CCP management strategies that could affect stakeholders and residents and the local economy is then presented. The refuge management activities of economic concern in this analysis are:

  5. Benchmarking an Unstructured-Grid Model for Tsunami Current Modeling

    Science.gov (United States)

    Zhang, Yinglong J.; Priest, George; Allan, Jonathan; Stimely, Laura

    2016-12-01

    We present model results derived from a tsunami current benchmarking workshop held by the NTHMP (National Tsunami Hazard Mitigation Program) in February 2015. Modeling was undertaken using our own 3D unstructured-grid model that has been previously certified by the NTHMP for tsunami inundation. Results for two benchmark tests are described here, including: (1) vortex structure in the wake of a submerged shoal and (2) impact of tsunami waves on Hilo Harbor in the 2011 Tohoku event. The modeled current velocities are compared with available lab and field data. We demonstrate that the model is able to accurately capture the velocity field in the two benchmark tests; in particular, the 3D model gives a much more accurate wake structure than the 2D model for the first test, with the root-mean-square error and mean bias no more than 2 cm s-1 and 8 mm s-1, respectively, for the modeled velocity.

  6. Neutronic characteristics of coupled moderator proposed in integrated model

    Energy Technology Data Exchange (ETDEWEB)

    Teshigawara, Makoto; Meigo, Shin-ichiro; Sakata, Hideaki; Kai, Tetsuya; Harada, Masahide; Ikeda, Yujiro; Watanabe, Noboru [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-05-01

    A pulsed spallation source for the materials science and the life science is currently developing for its construction in the High Intensity Proton Accelerator Project proposed jointly by the Japan Atomic Energy Research Institute (JAERI) and the High Energy Accelerator Research Organization (KEK). This report presents the analytical results of the neutronic characteristics of the coupled moderator based on the analytical results obtained by using an integrated model which has established on the extensive neutronic and technical study. Total heat deposition in a hydrogen (H{sub 2}) moderator working as the main moderator was about 420 W/MW. Maximum nuclear heat density in the H{sub 2} moderator was about 1 W/cm{sup 3}/MW. Also total heat deposition in a premoderator was about 9.2 kW/MW. The heat density of the premoderator was comparable to that of the moderator vessel made of aluminum alloy. The heat density of the premoderator and the moderator vessel is about 1.2-2 times higher than that of the hydrogen moderator. The temperature from 300 K to 400 K of the premoderator did not affect on neutron intensity of the H{sub 2} moderator. This suggested an engineering advantage on the thermal and hydraulic design. 6000 or 7000 type of a aluminum alloy was considered from the viewpoint of the neutron beam transmission. The proton beams scattered by the proton beam window did not affect on the nuclear heating in the H{sub 2} moderator. The heat deposition in the H{sub 2} moderator and the neutron intensity of the H{sub 2} moderator did not depend on the proton beam profile but it did on the distance between the proton beam and the moderator. (author)

  7. Analytical Modeling for the Grating Eddy Current Displacement Sensors

    Directory of Open Access Journals (Sweden)

    Lv Chunfeng

    2015-02-01

    Full Text Available As a new type of displacement sensor, grating eddy current displacement sensor (GECDS combines traditional eddy current sensors and grating structure in one. The GECDS performs a wide range displacement measurement without precision reduction. This paper proposes an analytical modeling approach for the GECDS. The solution model is established in the Cartesian coordinate system, and the solving domain is limited to finite extents by using the truncated region eigenfunction expansion method. Based on the second order vector potential, expressions for the electromagnetic field as well as coil impedance related to the displacement can be expressed in closed-form. Theoretical results are then confirmed by experiments, which prove the suitability and effectiveness of the analytical modeling approach.

  8. A study of model bivalve siphonal currents

    Science.gov (United States)

    Monismith, Stephen G.; Koseff, Jeffrey R.; Thompson, Janet K.; O'Riordan, Catherine A.; Nepf, Heidi M.

    1990-01-01

    We carried out experiments studying the hydrodynamics of bivalve siphonal currents in a laboratory flume. Rather than use living animals, we devised a simple, model siphon pair connected to a pump. Fluorescence-based flow visualization was used to characterize siphon-jet flows for several geometric configurations and flow speeds. These measurements show that the boundary-layer velocity profile, siphon height, siphon pair orientation, and size of siphon structure all affect the vertical distribution of the excurrent flow downstream of the siphon pair and the fraction of excurrent that is refiltered. The observed flows may effect both the clearance rate of an entire population of siphonate bivalves as well as the efficiency of feeding of any individual. Our results imply that field conditions are properly represented in laboratory flume studies of phytoplankton biomass losses to benthic bivalves when the shear velocity and bottom roughness are matched to values found in the field. Numerical models of feeding by a bivalve population should include an effective sink distribution which is created by the combined incurrent-excurrent flow field. Near-bed flows need to be accounted for to properly represent these benthic-pelagic exchanges. We also present velocity measurements made with a laser-Doppler anemometer (LDA) for a single configuration (siphons flush with bed, inlet downstream) that show that the siphonal currents have a significant local effect on the properties of a turbulent boundary layer.

  9. A turbidity current model for real world applications

    Science.gov (United States)

    Macías, Jorge; Castro, Manuel J.; Morales, Tomás

    2016-04-01

    Traditional turbidity current models suffer from several drawbacks. Among them not preserving freshwater mass, a missing pressure term, or not including terms related to deposition, erosion and entrainment in the momentum equation. In Morales et al.(2009) a new turbidity current model was proposed trying to overcome all these drawbacks. This model takes into account the interaction between the turbidity current and the bottom, considering deposition and erosion effects as well as solid bedload transport of particles at the bed due to the current. Moreover, this model includes the effects of the deposition, erosion and water entrainment into the momentum equation,commonly neglected in this type of models and, finally, in the absence of water entrainment, freshwater mass in the turbidity current is preserved. Despite these improvements, the numerical results obtained by this model when applied to real river systems were not satisfactory due to the simple form of the friction term that was considered. In the present work we propose a different parameterization of this term, where bottom and interface fluid frictions are separately parameterized with more complex expressions. Moreover, the discretization of the deposition/erosion terms is now performed semi-implicitly which guarantees the positivity of the volumetric concentration of sediments in suspension and in the erodible sediment layer at the bed. The numerical simulations obtained with this new turbidity current model (component of HySEA numerical computing platform) greatly improve previous numerical results for simplified geometries as well as for real river systems. Acknowledgements: This research has been partially supported by the Junta de Andalucía research project TESELA (P11-RNM7069) and the Spanish Government Research project DAIFLUID (MTM2012-38383-C02-01) and Universidad de Málaga, Campus de Excelencia Andalucía TECH. References: T. Morales, M. Castro, C. Parés, and E. Fernández-Nieto (2009). On

  10. A Proposed Model of Jazz Theory Knowledge Acquisition

    Science.gov (United States)

    Ciorba, Charles R.; Russell, Brian E.

    2014-01-01

    The purpose of this study was to test a hypothesized model that proposes a causal relationship between motivation and academic achievement on the acquisition of jazz theory knowledge. A reliability analysis of the latent variables ranged from 0.92 to 0.94. Confirmatory factor analyses of the motivation (standardized root mean square residual…

  11. A Proposed Model of Jazz Theory Knowledge Acquisition

    Science.gov (United States)

    Ciorba, Charles R.; Russell, Brian E.

    2014-01-01

    The purpose of this study was to test a hypothesized model that proposes a causal relationship between motivation and academic achievement on the acquisition of jazz theory knowledge. A reliability analysis of the latent variables ranged from 0.92 to 0.94. Confirmatory factor analyses of the motivation (standardized root mean square residual…

  12. 76 FR 31342 - Agency Information Collection Activities; Proposed Collection; Comment Request; Current Good...

    Science.gov (United States)

    2011-05-31

    ... Collection; Comment Request; Current Good Manufacturing Practice Regulations for Finished Pharmaceuticals... Current Good Manufacturing Practice (CGMP) Regulations for Finished Pharmaceuticals. DATES: Submit either... of information technology. Current Good Manufacturing Practice Regulations for...

  13. 75 FR 40840 - Agency Information Collection Activities; Proposed Collection; Comment Request; Current Good...

    Science.gov (United States)

    2010-07-14

    ... Collection; Comment Request; Current Good Manufacturing Practice in Manufacturing, Packaging, Labeling, or... information collection provisions of FDA's regulations regarding current good manufacturing practice (CGMP... appropriate, and other forms of information technology. Current Good Manufacturing Practice in......

  14. 78 FR 17215 - Agency Information Collection Activities: Proposed Collection; Comment Request; Current Good...

    Science.gov (United States)

    2013-03-20

    ... Collection; Comment Request; Current Good Manufacturing Practice for Positron Emission Tomography Drugs... regulations on current good manufacturing practice (CGMP) for positron emission tomography (PET) drugs. DATES... of information technology. Current Good Manufacturing Practice for Positron Emission Tomography...

  15. 75 FR 73101 - Agency Information Collection Activities; Proposed Collection; Comment Request; Current Good...

    Science.gov (United States)

    2010-11-29

    ... Collection; Comment Request; Current Good Manufacturing Practice Regulations for Medicated Feeds AGENCY: Food... appropriate, and other forms of information technology. Current Good Manufacturing Practice Regulations for... current good manufacturing practice (cGMP) regulations for drugs, including medicated feeds....

  16. Mirizzi syndrome: History, current knowledge and proposal of a simplified classification

    Institute of Scientific and Technical Information of China (English)

    Marcelo A Beltrán

    2012-01-01

    Chronic complications of symptomatic gallstone disease,such as Mirizzi syndrome,are rare in Western developed countries with an incidence of less than 1% a year.The importance and implications of this condition are related to their associated and potentially serious surgical complications such as bile duct injury,and to its modern management when encountered during laparoscopic cholecystectomy.The pathophysiological process leading to the subtypes of Mirizzi syndrome has been explained by means of a pressure ulcer caused by an impacted gallstone at the gallbladder infundibulum,leading to an inflammatory response causing first external obstruction of the bile duct,and eventually eroding into the bile duct and evolving to a cholecystocholedochal or cholecystohepatic fistula.This article reviews the life of Pablo Luis Mirizzi,describes the earlier and later descriptions of Mirizzi syndrome,discusses the pathophysiological process leading to the development of these uncommon fistulas,reviews the current diagnostic modalities and surgical approaches and finally proposes a simplified classification for Mirizzi syndrome intended to standardize the reports on this condition and to eventually develop a consensual surgical approach to this unexpected and seriously dangerous condition.

  17. An Optimization Model for A Proposed Trigeneration System

    Directory of Open Access Journals (Sweden)

    Bulut Kezban

    2016-11-01

    Full Text Available The combined cooling, heating, and power (CCHP systems play an important role in the reduction of carbon emissions and the increase of energy efficiency for businesses and social organizations. Because of its potentials, tri-generation system has become a preference during the last decade. In this paper a hybrid trigeneration system is proposed for a university campus. The system is also important because it uses renewable energy sources as well as non-renewable energy sources. The objective of this paper is to propose an optimization model for this new Tri-generation system

  18. Proposed reporting model update creates dialogue between FASB and not-for-profits.

    Science.gov (United States)

    Mosrie, Norman C

    2016-04-01

    Seeing a need to refresh the current guidelines, the Financial Accounting Standards Board (FASB) proposed an update to the financial accounting and reporting model for not-for-profit entities. In a response to solicited feedback, the board is now revisiting its proposed update and has set forth a plan to finalize its new guidelines. The FASB continues to solicit and respond to feedback as the process progresses.

  19. Standards for scalable clinical decision support: need, current and emerging standards, gaps, and proposal for progress.

    Science.gov (United States)

    Kawamoto, Kensaku; Del Fiol, Guilherme; Lobach, David F; Jenders, Robert A

    2010-01-01

    Despite their potential to significantly improve health care, advanced clinical decision support (CDS) capabilities are not widely available in the clinical setting. An important reason for this limited availability of CDS capabilities is the application-specific and institution-specific nature of most current CDS implementations. Thus, a critical need for enabling CDS capabilities on a much larger scale is the development and adoption of standards that enable current and emerging CDS resources to be more effectively leveraged across multiple applications and care settings. Standards required for such effective scaling of CDS include (i) standard terminologies and information models to represent and communicate about health care data; (ii) standard approaches to representing clinical knowledge in both human-readable and machine-executable formats; and (iii) standard approaches for leveraging these knowledge resources to provide CDS capabilities across various applications and care settings. A number of standards do exist or are under development to meet these needs. However, many gaps and challenges remain, including the excessive complexity of many standards; the limited availability of easily accessible knowledge resources implemented using standard approaches; and the lack of tooling and other practical resources to enable the efficient adoption of existing standards. Thus, the future development and widespread adoption of current CDS standards will depend critically on the availability of tooling, knowledge bases, and other resources that make the adoption of CDS standards not only the right approach to take, but the cost-effective path to follow given the alternative of using a traditional, ad hoc approach to implementing CDS.

  20. Wetland Planning: Current Problems and Environmental Management Proposals at Supra-Municipal Scale (Spanish Mediterranean Coast

    Directory of Open Access Journals (Sweden)

    María-Teresa Sebastiá-Frasquet

    2014-03-01

    Full Text Available The policies that define the use and management of wetlands in Spain have undergone tremendous changes in recent decades. During the period of 1950–1980, Land Reform Plans promoted filling and draining of these areas for agricultural use. In 1986, with the incorporation of Spain to the European Union (EU, there was a sudden change of direction in these policies, which, thereafter, pursued restoring and protecting these ecosystems. This change, combined with increasing urban development and infrastructure pressures (e.g., roads, golf courses, etc., creates a conflict of uses which complicates the management of these ecosystems by local governments. This study analyzes the effectiveness of policies and management tools of important coastal wetlands at the local scale in the Valencian Community (Western Mediterranean Sea using a strengths-weaknesses-opportunities-threats (SWOT methodology. A supra-municipal model of environmental planning is proposed to enable consistent management at a regional scale. This model enhances local government’s effectiveness and it can be applied in other areas with similar problems.

  1. Bayesian inference of chemical kinetic models from proposed reactions

    KAUST Repository

    Galagali, Nikhil

    2015-02-01

    © 2014 Elsevier Ltd. Bayesian inference provides a natural framework for combining experimental data with prior knowledge to develop chemical kinetic models and quantify the associated uncertainties, not only in parameter values but also in model structure. Most existing applications of Bayesian model selection methods to chemical kinetics have been limited to comparisons among a small set of models, however. The significant computational cost of evaluating posterior model probabilities renders traditional Bayesian methods infeasible when the model space becomes large. We present a new framework for tractable Bayesian model inference and uncertainty quantification using a large number of systematically generated model hypotheses. The approach involves imposing point-mass mixture priors over rate constants and exploring the resulting posterior distribution using an adaptive Markov chain Monte Carlo method. The posterior samples are used to identify plausible models, to quantify rate constant uncertainties, and to extract key diagnostic information about model structure-such as the reactions and operating pathways most strongly supported by the data. We provide numerical demonstrations of the proposed framework by inferring kinetic models for catalytic steam and dry reforming of methane using available experimental data.

  2. Energy current loss instability model on a computer

    Science.gov (United States)

    Edighoffer, John A.

    1995-04-01

    The computer program called Energy Stability in a Recirculating Accelerator (ESRA) Free Electron Laser (FEL) has been written to model bunches of particles in longitudinal phase space transversing a recirculating accelerator and the associated rf changes and aperture current losses. This energy-current loss instability was first seen by Los Alamos's FEL group in their energy recovery experiments. This code addresses these stability issues and determines the transport, noise, feedback and other parameters for which these FEL systems are stable or unstable. Two representative systems are modeled, one for the Novosibirisk high power FEL racetrack microtron for photochemical research, the other is the CEBAF proposed UV FEL system. Both of these systems are stable with prudent choices of parameters.

  3. Electric Propulsion System Modeling for the Proposed Prometheus 1 Mission

    Science.gov (United States)

    Fiehler, Douglas; Dougherty, Ryan; Manzella, David

    2005-01-01

    The proposed Prometheus 1 spacecraft would utilize nuclear electric propulsion to propel the spacecraft to its ultimate destination where it would perform its primary mission. As part of the Prometheus 1 Phase A studies, system models were developed for each of the spacecraft subsystems that were integrated into one overarching system model. The Electric Propulsion System (EPS) model was developed using data from the Prometheus 1 electric propulsion technology development efforts. This EPS model was then used to provide both performance and mass information to the Prometheus 1 system model for total system trades. Development of the EPS model is described, detailing both the performance calculations as well as its evolution over the course of Phase A through three technical baselines. Model outputs are also presented, detailing the performance of the model and its direct relationship to the Prometheus 1 technology development efforts. These EP system model outputs are also analyzed chronologically showing the response of the model development to the four technical baselines during Prometheus 1 Phase A.

  4. A proposal for a consistent parametrization of earth models

    Science.gov (United States)

    Forbriger, Thomas; Friederich, Wolfgang

    2005-08-01

    The current way to parametrize earth models in terms of real-valued seismic velocities and quality factors is incomplete as it does not specify how complex-valued viscoelastic moduli or complex velocities should be computed from them. Various ways to do this can be found in the literature. Depending on the context they may specify (1) the real part of the viscoelastic modulus, (2) the absolute value of the viscoelastic modulus, (3) the real part of complex velocity or (4) the phase velocity of a propagating plane wave. We propose here to exclusively use the first alternative because it is the only one which allows both a flexible choice of elastic parameters and a mathematically rigorous evaluation of the complex-valued viscoelastic moduli. The other definitions only permit an evaluation of viscoelastic moduli if the tabulated quality factors are directly associated with the listed velocities. Ignoring the subtle differences between the three definitions leads to variations in viscoelastic moduli which are second order in 1/Q where Q is a quality factor. This may be the reason why the topic has never been discussed in the literature. In case of shallow seismic media, however, where quality factors may assume values of less than 10, the subtle differences become noticeable in synthetic seismograms. It is then essential to use the same definition in all algorithms to make results comparable. Matters become worse for anisotropic media, which are commonly specified in terms of real elastic moduli and quality factors for effective isotropic moduli. In that case, the complex-valued viscoelastic moduli cannot be determined uniquely. However, interpreting the tabulated constants as the real parts of the complex-valued viscoelastic moduli at least allows a consistent definition, which respects the relative magnitude of the anelastic and anisotropic parts compared to the elastic parts. It should be noted that all these considerations apply to complex-valued viscoelastic

  5. An investigation of environmental factors associated with the current and proposed jetty systems at Belle Pass, Louisiana

    Science.gov (United States)

    Dantin, E. J.; Whitehurst, C. A.; Durbin, W. T.

    1974-01-01

    The history of the existing jetty system at Belle Pass was investigated to determine its past effect on the littoral currents and beach erosion. Present flow patterns and erosion rates were also studied, along with the prevailing recession rates of local beaches not influenced by the jetty system. Aerial photographs and maps were used in conjunction with periodic hydraulic measurements, ground observations, and physical measurements of beach erosion. A scale model was constructed to further the study of flow patterns and velocities. It is shown that the existing jetty has not adversely affected the coastline in the area; erosive processes have been retarded by the jetty and its companion groin. Future erosion patterns are predicted, and projected effects of the proposed jetty system are given.

  6. Proposed Bilingual Model for Right to Left Language Applications

    Directory of Open Access Journals (Sweden)

    Farhan M Al Obisat

    2016-09-01

    Full Text Available Using right to left languages (RLL in software programming requires switching the direction of many components in the interface. Preserving the original interface layout and only changing the language may result in different semantics or interpretations of the content. However, this aspect is often dismissing in the field. This research, therefore, proposes a Bilingual Model (BL to check and correct the directions in social media applications. Moreover, test-driven development (TDD For RLL, such as Arabic, is considered in the testing methodologies. Similarly, the bilingual analysis has to follow both the TDD and BL models.

  7. The Proposal of Model for Building Cooperation Management in Company

    Directory of Open Access Journals (Sweden)

    Josef Vodák

    2015-12-01

    Full Text Available The goal of the article is to use detailed literature analysis and findings of an empirical research, and to propose model for building cooperation management in a company. The article brings a valuable tool to company managers in a form of a complex and detailed model to achieve successful implementation of cooperation management in a company. The article thus provides a tool for company managers for managing their cooperation projects and activities. Use of this tool is meant to help minimize occurrence of conflict situations and to support smooth progress of cooperation activities.

  8. 75 FR 72827 - Agency Information Collection Activities; Proposed Collection; Comment Request; Current Good...

    Science.gov (United States)

    2010-11-26

    ... Collection; Comment Request; Current Good Manufacturing Practice Regulations for Type A Medicated Articles... appropriate, and other forms of information technology. Current Good Manufacturing Practice Regulations for... authority to issue current good manufacturing practice (cGMP) regulations for drugs, including type...

  9. Massive fermion model in 3d and higher spin currents

    CERN Document Server

    Bonora, L; Prester, P Dominis; de Souza, B Lima; Smolic, I

    2016-01-01

    We analyze the 3d free massive fermion theory coupled to external sources. The presence of a mass explicitly breaks parity invariance. We calculate two- and three-point functions of a gauge current and the energy momentum tensor and, for instance, obtain the well-known result that in the IR limit (but also in the UV one) we reconstruct the relevant CS action. We then couple the model to higher spin currents and explicitly work out the spin 3 case. In the UV limit we obtain an effective action which was proposed many years ago as a possible generalization of spin 3 CS action. In the IR limit we derive a different higher spin action. This analysis can evidently be generalized to higher spins. We also discuss the conservation and properties of the correlators we obtain in the intermediate steps of our derivation.

  10. Proposal for a race-track microtron with high peak current

    NARCIS (Netherlands)

    Ernst, G.J.; Haselhoff, E.H.; Witteman, W.J.; Botman, J.I.M.; Genderen, van W.; Hagedoorn, H.L.; Heide, van der J.A.; Kleeven, W.J.G.M.

    1989-01-01

    In order to obtain high gain in a free electron laser a high-quality electron beam with high peak current is required. It is well-known that a microtron is able to produce a high-quality beam having low emittance and small energy spread (1%). Because a circular microtron has a limited high-current c

  11. A PROPOSAL OF A PROCESS MODEL FOR POSTAL ELECTRONIC SERVICE IMPLEMENTATION

    Directory of Open Access Journals (Sweden)

    Bystrík Nemček

    2015-09-01

    Full Text Available This article is dedicated to one of the main business processes–implementation of the postal electronic service. Theoretical point of view is focused on Business Process Management (BPM describing it as a field in systems engineering that focuses on activity of representing processes of an enterprise, so that the current process may be analyzed or improved. The main aim of the practical point of view was to design a model of postal electronic service implementation. A proposal of model is designed in Business Process Model Notation (BPMN, which is a graphical representation for specifying business processes in a business process model

  12. PROPOSAL OF A MODEL MANAGEMENT TO SMALL DESIGN COMPANIES

    Directory of Open Access Journals (Sweden)

    Otávio José de OLIVEIRA

    2008-11-01

    Full Text Available The main purpose of this paper is the proposition of a management model specifically developed for small building design firms, aligned with their needs and particularities. The field research was conducted with a qualitative approach through the analysis of four case studies in small building design firms acting mainly in São Paulo City. The data collection was accomplished through semi-structured interviews, direct observation and analysis of documents. The proposed model includes guidance to the management of the core processes and activities of small building design firms, such as: organizational structure; strategic planning; planning and control of design process; costs management; sales management; information systems; human resources management; services added to the design; and performance evaluation. Key-words: design firms; design process; building construction.

  13. Avian Models for Human Cognitive Neuroscience: A Proposal.

    Science.gov (United States)

    Clayton, Nicola S; Emery, Nathan J

    2015-06-17

    Research on avian cognitive neuroscience over the past two decades has revealed the avian brain to be a better model for understanding human cognition than previously thought, despite differences in the neuroarchitecture of avian and mammalian brains. The brain, behavior, and cognition of songbirds have provided an excellent model of human cognition in one domain, namely learning human language and the production of speech. There are other important behavioral candidates of avian cognition, however, notably the capacity of corvids to remember the past and plan for the future, as well as their ability to think about another's perspective, and physical reasoning. We review this work and assess the evidence that the corvid brain can support such a cognitive architecture. We propose potential applications of these behavioral paradigms for cognitive neuroscience, including recent work on single-cell recordings and neuroimaging in corvids. Finally, we discuss their impact on understanding human developmental cognition. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. The evaluation of doctoral thesis. A model proposal

    Directory of Open Access Journals (Sweden)

    de-Miguel, Mario

    2010-04-01

    Full Text Available The aim of this work is the development of a model that can be used as a framework for evaluators and PhD tribunal members, either during the previous administrative processing phase or at the actual exposition and viva on doctoral dissertations. To this end, once reviewed the existing literature and normative, a new proposal is laid out on the main aspects and criteria to be analysed and assessed from any given scientific work, thus introducing a tool that facilitates and specifies this work. Our model is intended to be an open proposal on which we would welcome any contribution and suggestion. El objetivo del presente trabajo es la elaboración de un modelo que pueda ser utilizado como marco de referencia por los evaluadores y miembros de tribunales de las tesis doctorales tanto en la fase previa a la tramitación administrativa como en el acto de exposición y defensa de la misma. Para ello, una vez revisada la literatura y la normativa vigente al respecto, efectuamos una propuesta sobre los principales aspectos y criterios que deben ser objeto de análisis y valoración en todo trabajo científico, y presentamos una herramienta que facilita y precisa esta tarea. Nuestro modelo constituye una propuesta abierta sobre la que esperamos aportaciones y sugerencias.

  15. Functional Analytic Psychotherapy (FAP) in Ibero-America: Review of Current Status and Some Proposals

    Science.gov (United States)

    Munoz-Martinez, Amanda; Novoa-Gomez, Monica; Gutierrez, Rochy Vargas

    2012-01-01

    Functional Analytic Psychotherapy (FAP) has been making an important rise in Ibero-America in recent years. This paper presents a review of different contributions, problems and some proposals. Three principal topics are reviewed: (a) general characteristics and theoretical bases of FAP, (b) the uses of FAP and its relationship with other…

  16. Design of Current Controller for Two Quadrant DC Motor Drive by Using Model Order Reduction Technique

    CERN Document Server

    Ramesh, K; Nirmalkumar, A; Gurusamy, G

    2010-01-01

    In this paper, design of current controller for a two quadrant DC motor drive was proposed with the help of model order reduction technique. The calculation of current controller gain with some approximations in the conventional design process is replaced by proposed model order reduction method. The model order reduction technique proposed in this paper gives the better controller gain value for the DC motor drive. The proposed model order reduction method is a mixed method, where the numerator polynomial of reduced order model is obtained by using stability equation method and the denominator polynomial is obtained by using some approximation technique preceded in this paper. The designed controllers responses were simulated with the help of MATLAB to show the validity of the proposed method.

  17. Product/Service-Systems: Proposal for models and terminology

    DEFF Research Database (Denmark)

    Matzen, Detlef; Tan, Adrian; Andreasen, Mogens Myrup

    2005-01-01

    Over recent years a growing number of studies and research programmes have been conducted on the issue of product/service-systems (PSS) [1, 2] and results have been presented at this row of symposia [3, 4]. These studies usually analyse the potential of integrated solutions to reduce the environm......Over recent years a growing number of studies and research programmes have been conducted on the issue of product/service-systems (PSS) [1, 2] and results have been presented at this row of symposia [3, 4]. These studies usually analyse the potential of integrated solutions to reduce...... very blurred and ill defined. This paper will try to identify the fundamental characteristics of PSS and propose a system of concepts that can be used to describe and discuss the phenomenon, for the purpose of developing new PSS solutions. Coming from a tradition of product development research...... development models. Furthermore, the models should be able to integrate with the existing models and concepts of new product development....

  18. Evidence-based ergonomics: a model and conceptual structure proposal.

    Science.gov (United States)

    Silveira, Dierci Marcio

    2012-01-01

    In Human Factors and Ergonomics Science (HFES), it is difficult to identify what is the best approach to tackle the workplace and systems design problems which needs to be solved, and it has been also advocated as transdisciplinary and multidisciplinary the issue of "How to solve the human factors and ergonomics problems that are identified?". The proposition on this study is to combine the theoretical approach for Sustainability Science, the Taxonomy of the Human Factors and Ergonomics (HFE) discipline and the framework for Evidence-Based Medicine in an attempt to be applied in Human Factors and Ergonomics. Applications of ontologies are known in the field of medical research and computer science. By scrutinizing the key requirements for the HFES structuring of knowledge, it was designed a reference model, First, it was identified the important requirements for HFES Concept structuring, as regarded by Meister. Second, it was developed an evidence-based ergonomics framework as a reference model composed of six levels based on these requirements. Third, it was devised a mapping tool using linguistic resources to translate human work, systems environment and the complexities inherent to their hierarchical relationships to support future development at Level 2 of the reference model and for meeting the two major challenges for HFES, namely, identifying what problems should be addressed in HFE as an Autonomous Science itself and proposing solutions by integrating concepts and methods applied in HFES for those problems.

  19. 76 FR 45262 - Agency Information Collection Activities; Proposed Collection; Comment Request; Current Good...

    Science.gov (United States)

    2011-07-28

    ... of information technology. Current Good Manufacturing Practices and Related Regulations for Blood and... information and counseling to a donor determined not to be eligible for donation as usual and customary... establishments would need to provide, under Sec. 630.6(a), additional information and onsite counseling to...

  20. 75 FR 3763 - Proposed Collection; Comment Request for Review of a Currently Approved Information Collection

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    2010-01-22

    ... currently approved information collection. ``Survivor Annuity Election for a Spouse'' (OMB Control No. 3206... Are Providing a Former Spouse Annuity. Both booklets explain the election. RI 20-63A is for annuitants... contact: Cyrus S. Benson, Team Leader, Publications Team, RIS Support Services/ Support Group, U.S....

  1. Corporate Social Responsibility And Islamic Business Organizations: A Proposed Model

    Directory of Open Access Journals (Sweden)

    Rusnah Muhamad

    2008-01-01

    Full Text Available The issue of corporate social responsibility (CSR has been of growing concern among business communities in recent years. Various corporate leaders maintain that business is considered to contribute fully to the society if it is effi cient, profi table and socially responsible. Islam is considered as addin (a way of life, thus, providing comprehensive guidelines in every aspects of the believers’ life. It is the aim of this paper to propose an Islamic model of corporate social responsibility based on human relationships with the God (hablun min’Allah; with other fellow human being (hablun min’an-nas and with the environment.Keywords : Corporate Social Responsibility, Islamic Business Organization

  2. Tsunami-HySEA model validation for tsunami current predictions

    Science.gov (United States)

    Macías, Jorge; Castro, Manuel J.; González-Vida, José Manuel; Ortega, Sergio

    2016-04-01

    Model ability to compute and predict tsunami flow velocities is of importance in risk assessment and hazard mitigation. Substantial damage can be produced by high velocity flows, particularly in harbors and bays, even when the wave height is small. Besides, an accurate simulation of tsunami flow velocities and accelerations is fundamental for advancing in the study of tsunami sediment transport. These considerations made the National Tsunami Hazard Mitigation Program (NTHMP) proposing a benchmark exercise focussed on modeling and simulating tsunami currents. Until recently, few direct measurements of tsunami velocities were available to compare and to validate model results. After Tohoku 2011 many current meters measurement were made, mainly in harbors and channels. In this work we present a part of the contribution made by the EDANYA group from the University of Malaga to the NTHMP workshop organized at Portland (USA), 9-10 of February 2015. We have selected three out of the five proposed benchmark problems. Two of them consist in real observed data from the Tohoku 2011 event, one at Hilo Habour (Hawaii) and the other at Tauranga Bay (New Zealand). The third one consists in laboratory experimental data for the inundation of Seaside City in Oregon. Acknowledgements: This research has been partially supported by the Junta de Andalucía research project TESELA (P11-RNM7069) and the Spanish Government Research project DAIFLUID (MTM2012-38383-C02-01) and Universidad de Málaga, Campus de Excelencia Andalucía TECH. The GPU and multi-GPU computations were performed at the Unit of Numerical Methods (UNM) of the Research Support Central Services (SCAI) of the University of Malaga.

  3. Evaluation of a proposed optimization method for discrete-event simulation models

    Directory of Open Access Journals (Sweden)

    Alexandre Ferreira de Pinho

    2012-12-01

    Full Text Available Optimization methods combined with computer-based simulation have been utilized in a wide range of manufacturing applications. However, in terms of current technology, these methods exhibit low performance levels which are only able to manipulate a single decision variable at a time. Thus, the objective of this article is to evaluate a proposed optimization method for discrete-event simulation models based on genetic algorithms which exhibits more efficiency in relation to computational time when compared to software packages on the market. It should be emphasized that the variable's response quality will not be altered; that is, the proposed method will maintain the solutions' effectiveness. Thus, the study draws a comparison between the proposed method and that of a simulation instrument already available on the market and has been examined in academic literature. Conclusions are presented, confirming the proposed optimization method's efficiency.

  4. Current status of cosmological MDM model

    CERN Document Server

    Mikheeva, E V; Arkhipova, N A; Malinovsky, A M

    2000-01-01

    An analysis of cosmological models in spatially flat Friedmann Universe with cosmic gravitational wave background and zero $\\Lambda$-term is presented. The number of free parameters is equal to 5, they are $\\sigma_8$, $n$, $\\Omega_\

  5. Surface CUrrents from a Diagnostic model (SCUD): Pacific

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The SCUD data product is an estimate of upper-ocean velocities computed from a diagnostic model (Surface CUrrents from a Diagnostic model). This model makes daily...

  6. Modeling of current distribution on smooth and columnar platinum structures.

    Science.gov (United States)

    Zinola, Carlos F

    2011-01-17

    Studying the growth and stability of anisotropic or isotropic disordered surfaces in electrodeposition is of importance in catalytic electrochemistry. In some cases, the metallic nature of the electrode defines the topography and roughness, which are also controlled by the experimental time and applied external potential. Because of the experimental restrictions in conventional electrochemical techniques and ex situ electron microscopies, a theoretical model of the surface geometry could aid in understanding the electrodeposition process and current distributions. In spite of applying a complex theory such as dynamic scaling method or perturbation theories, the resolution of mixed mass-/charge-transfer equations (tertiary distribution) for the electrodeposition process would give reliable information. One of the main problems with this type of distribution is the mathematics when solving the spatial n-dimensional differential equations. Use of a primary current distribution is proposed here to simplify the differential equations; however it limits wide application of the first assumption. Distributions of concentration profile, current density, and electrode potential are presented here as a function of the distance normal to the surface for the cases of smooth and rough platinum growth. In the particular case of columnar surfaces, cycloid curves are used to model the electrode, from which the concentration profile is presented in a parameterized form after solving a first-type curvilinear integral. The concentration contour results in a combination of a trigonometric inverse function and a linear distribution leading to a negative concavity curve. The calculation of the current density and electrode potential contours also show trigonometric shapes exhibiting forbidden imaginary values only at the minimal values of the trochoid curve.

  7. Methodology Using MELCOR Code to Model Proposed Hazard Scenario

    Energy Technology Data Exchange (ETDEWEB)

    Gavin Hawkley

    2010-07-01

    This study demonstrates a methodology for using the MELCOR code to model a proposed hazard scenario within a building containing radioactive powder, and the subsequent evaluation of a leak path factor (LPF) (or the amount of respirable material which that escapes a facility into the outside environment), implicit in the scenario. This LPF evaluation will analyzes the basis and applicability of an assumed standard multiplication of 0.5 × 0.5 (in which 0.5 represents the amount of material assumed to leave one area and enter another), for calculating an LPF value. The outside release is dependsent upon the ventilation/filtration system, both filtered and un-filtered, and from other pathways from the building, such as doorways (, both open and closed). This study is presents ed to show how the multiple leak path factorsLPFs from the interior building can be evaluated in a combinatory process in which a total leak path factorLPF is calculated, thus addressing the assumed multiplication, and allowing for the designation and assessment of a respirable source term (ST) for later consequence analysis, in which: the propagation of material released into the environmental atmosphere can be modeled and the dose received by a receptor placed downwind can be estimated and the distance adjusted to maintains such exposures as low as reasonably achievableALARA.. Also, this study will briefly addresses particle characteristics thatwhich affect atmospheric particle dispersion, and compares this dispersion with leak path factorLPF methodology.

  8. PTSD's latent structure in Malaysian tsunami victims: assessing the newly proposed Dysphoric Arousal model.

    Science.gov (United States)

    Armour, Cherie; Raudzah Ghazali, Siti; Elklit, Ask

    2013-03-30

    The underlying latent structure of Posttraumatic Stress Disorder (PTSD) is widely researched. However, despite a plethora of factor analytic studies, no single model has consistently been shown as superior to alternative models. The two most often supported models are the Emotional Numbing and the Dysphoria models. However, a recently proposed five-factor Dysphoric Arousal model has been gathering support over and above existing models. Data for the current study were gathered from Malaysian Tsunami survivors (N=250). Three competing models (Emotional Numbing/Dysphoria/Dysphoric Arousal) were specified and estimated using Confirmatory Factor Analysis (CFA). The Dysphoria model provided superior fit to the data compared to the Emotional Numbing model. However, using chi-square difference tests, the Dysphoric Arousal model showed a superior fit compared to both the Emotional Numbing and Dysphoria models. In conclusion, the current results suggest that the Dysphoric Arousal model better represents PTSD's latent structure and that items measuring sleeping difficulties, irritability/anger and concentration difficulties form a separate, unique PTSD factor. These results are discussed in relation to the role of Hyperarousal in PTSD's on-going symptom maintenance and in relation to the DSM-5.

  9. The current situation of impact of coal mine developing on environment in China and government proposal

    Energy Technology Data Exchange (ETDEWEB)

    Lu Yang [China University of Mining and Technology, Beijing (China). Ministry of Land and Resources

    2005-07-01

    Current environmental problems caused by coal mining in China, the importance of management of the environment, impact of coal mining on land and water resources, and upcoming coal development are discussed. It is suggested that the government should act in two ways: take responsibility for management of reclamation of mines existing before 1986, and set up mechanisms to protect the environment, starting with the publishing of relevant laws and regulations. Methods for solving environmental issues include: prepare a practical plan, establish an environmental control fund, establish a special fund to protect the environment, and develop new ways to combine protection of the biological environment and land reclamation. 5 refs., 3 tabs.

  10. QAM: PROPOSED MODEL FOR QUALITY ASSURANCE IN CBSS

    Directory of Open Access Journals (Sweden)

    Latika Kharb

    2015-08-01

    Full Text Available Component-based software engineering (CBSE / Component-Based Development (CBD lays emphasis on decomposition of the engineered systems into functional or logical components with well-defined interfaces used for communication across the components. Component-based software development approach is based on the idea to develop software systems by selecting appropriate off-the-shelf components and then to assemble them with a well-defined software architecture. Because the new software development paradigm is much different from the traditional approach, quality assurance for component-based software development is a new topic in the software engineering research community. Because component-based software systems are developed on an underlying process different from that of the traditional software, their quality assurance model should address both the process of components and the process of the overall system. Quality assurance for component-based software systems during the life cycle is used to analyze the components for achievement of high quality component-based software systems. Although some Quality assurance techniques and component based approach to software engineering have been studied, there is still no clear and well-defined standard or guidelines for component-based software systems. Therefore, identification of the quality assurance characteristics, quality assurance models, quality assurance tools and quality assurance metrics, are under urgent need. As a major contribution in this paper, I have proposed QAM: Quality Assurance Model for component-based software development, which covers component requirement analysis, component development, component certification, component architecture design, integration, testing, and maintenance.

  11. Islamic Theoretical Intertemporal Model of the Current Account

    Directory of Open Access Journals (Sweden)

    Hassan Belkacem Ghassan

    2016-06-01

    Full Text Available This paper aims to develop an Islamic intertemporal model of the current account based on the prevailing theoretical and empirical literature of PVMCA (Obstfeld and Rogoff, 1996, Cerrato et al., 2014. The proposed model is based on the budget constraint of the present and future consumption, which depends on the obligatory Zakat from the income and assets, the return rate on the owned assets, the inheritance linking previous to subsequent generation. Using logarithmic utility function, featured by a unitary elasticity of intertemporal substitution and a unitary coefficient of relative risk aversion, we show through Euler equation of consumption that there is an inverse relationship between consumption growth from the last age to the first one and the Zakat rate on assets. The outcomes of this result are that the Zakat on assets disciplines the consumer to have more rationality in consumption, and allows additional marginal assets for future generations. By assuming a unitary subjective discount rate, we indicate that the more the return rate on assets is high, the more the consumption growth between today and tomorrow will be fast. Through the budget constraint, if Zakat rate on the Zakatable assets is greater than Zakat rate on income, this leads to a relative expansion in private consumption of the wealthy group. Besides, we point out that an increase in return rate on assets, can drive to increasing or decreasing current consumption, because the substitution and income effects work in opposite ways.

  12. Current Density and Continuity in Discretized Models

    Science.gov (United States)

    Boykin, Timothy B.; Luisier, Mathieu; Klimeck, Gerhard

    2010-01-01

    Discrete approaches have long been used in numerical modelling of physical systems in both research and teaching. Discrete versions of the Schrodinger equation employing either one or several basis functions per mesh point are often used by senior undergraduates and beginning graduate students in computational physics projects. In studying…

  13. Models of Solar Irradiance Variations: Current Status

    Indian Academy of Sciences (India)

    Natalie A. Krivova; Sami K. Solanki

    2008-03-01

    Regular monitoring of solar irradiance has been carried out since 1978 to show that solar total and spectral irradiance varies at different time scales. Whereas variations on time scales of minutes to hours are due to solar oscillations and granulation, variations on longer time scales are driven by the evolution of the solar surface magnetic field. Here the most recent advances in modelling of solar irradiance variations on time scales longer than a day are briefly reviewed.

  14. Analysis of the current situation regarding the aging rural population in China and proposed countermeasures.

    Science.gov (United States)

    Qu, Bo; Li, Xiyuan; Liu, Jie; Mao, Jiawen

    2012-06-01

    China has become a country with an aging population. Compared with the aged in urban areas, the aged in rural areas have low income and are subject to social security deficiencies; the oldest among them are the most vulnerable group. If an effective mechanism for handling health risk is not available, the poor health of the rural elderly will cause an increase in their poverty level, which in turn will cause their health to become worse. Therefore, it is essential to analyze the current situation regarding rural population aging in China and to develop countermeasures. Data from 4 national health services surveys were used to analyze the differences between urban and rural populations. The results of the analysis revealed that the aged population in rural areas has poor health; economic security for the aged population is insufficient; and resources for the aged are lacking in rural areas. The Chinese government should improve medicare for the aged in rural areas, and establish a medical treatment subsidy system and a medical support system for the aged in rural areas.

  15. A proposal for improving the hadronization of QCD currents in TAUOLA

    CERN Document Server

    Roig, Pablo

    2008-01-01

    After overviewing the general features of semileptonic decays of the tau lepton, I will recall the most widely used model for them, namely that of Kuhn-Santamaria (KS), and I will explain the subsequent works that were done along these lines and that are implemented in the TAUOLA library for analysing tau decays. After that, I will move to the description of our project that aims to achieve a theory as close as possible to QCD for the considered decays. I conclude by emphasizing the importance of the implementation of our work in TAUOLA.

  16. A Catapult (Slingshot) Current Sheet Relaxation Model for Substorm Triggering

    Science.gov (United States)

    Machida, S.; Miyashita, Y.; Ieda, A.

    2010-12-01

    Based on the results of our superposed epoch analysis of Geotail data, we have proposed a catapult (slingshot) current sheet relaxation model in which earthward flows are produced in the central plasma sheet (CPS) due to the catapult (slingshot) current sheet relaxation, together with the rapid enhancement of Poynting flux toward the CPS in the lobe around X ~ -15 Re about 4 min before the substrom onset. These earthward flows are characterized by plasma pressure decrease and large amplitude magnetic field fluctuations. When these flows reach X ~ 12Re in the magnetotail, they give significant disturbances to the inner magnetosphere to initiate some instability such as a ballooning instability or other instabilities, and the substorm starts in the inner magnetosphere. The occurrence of the magnetic reconnection is a natural consequence of the initial convective earthward flows, because the relaxation of a highly stretched catapult current sheet produces a very thin current at its tailward edge being surrounded by intense magnetic fields which were formerly the off-equatorial lobe magnetic fields. Recently, Nishimura et al. [2010] reported that the substorm onset begins when faint poleward discrete arcs collide with equatorward quiet arcs. The region of earthward convective flows correlatively moves earthward prior to the onset. Thus, this region of the earthward convective flows seems to correspond to the faint poleward discrete arcs. Interestingly, our statistical analysis shows that the earthward convective flows are not produced by the magnetic reconnection, but they are attributed to the dominance of the earthward JxB force over the tailward pressure associated with the progress of the plasma sheet thinning.

  17. Current-voltage model of LED light sources

    DEFF Research Database (Denmark)

    Beczkowski, Szymon; Munk-Nielsen, Stig

    2012-01-01

    Amplitude modulation is rarely used for dimming light-emitting diodes in polychromatic luminaires due to big color shifts caused by varying magnitude of LED driving current and nonlinear relationship between intensity of a diode and driving current. Current-voltage empirical model of light...

  18. Simulation of Current Measurement Using Magnetic Sensor Arrays and Its Error Model

    Institute of Scientific and Technical Information of China (English)

    WANGJing; YAOJian-jun; WANGJian-hua

    2004-01-01

    Magnetic sensor arrays are proposed to measure electric current in a non-contac tway. In order to achieve higher accuracy, signal processing techniques for magnetic sensor arrays are utilized. Simulation techniques are necessary to study the factors influencing the accuracy of current measurement. This paper presents a simulation method to estimate the impact of sensing area and position of sensors on the accuracy of current measurement. Several error models are built up to support computer-aided design of magnetic sensor arrays.

  19. Modeling the current distribution in HTS tapes with transport current and applied magnetic field

    NARCIS (Netherlands)

    Yazawa, Takashi; Rabbers, Jan-Jaap; Shevchenko, Oleg A.; Haken, ten Bennie; Kate, ten Herman H.J.; Maeda, Hideaki

    1999-01-01

    A numerical model is developed for the current distribution in a high temperature superconducting (HTS) tape, (Bi,Pb)2Sr2 Ca2Cu3Ox-Ag, subjected to a combination of a transport current and an applied magnetic field. This analysis is based on a two-dimensional formulation of Maxwell's equations in te

  20. Modelling counter-current chromatography: a chemical engineering perspective.

    Science.gov (United States)

    Kostanian, A E

    2002-10-11

    In conventional chromatography, a solute is usually viewed to be longitudinally transported only in the mobile phase, remaining longitudinally motionless in the stationary phase. In counter-current chromatography, both phases undergo intense mixing in the variable force field of a coil planet centrifuge and longitudinal dispersion of matter in the stationary phase is not to be excluded. To take into account longitudinal mixing in both phases, a cell model of chromatographic process is proposed in which the number of perfectly mixed cells n is determined by the rates of mixing in stationary (Ds) and mobile (Dm) phases by the equation n = LF/(2ADc)/(1 + Sf(lambda - 1)) with A = K(D)D(S)/Dm (F, L, Ac and KD are the mobile phase flow-rate, column length, column cross-section and distribution ratio, respectively). This equation has been derived by comparing the discontinuous cell model with continuous diffusion assuming equilibrium conditions. Parameter determination and their relationships are discussed.

  1. Current focusing and steering: modeling, physiology, and psychophysics.

    Science.gov (United States)

    Bonham, Ben H; Litvak, Leonid M

    2008-08-01

    Current steering and current focusing are stimulation techniques designed to increase the number of distinct perceptual channels available to cochlear implant (CI) users by adjusting currents applied simultaneously to multiple CI electrodes. Previous studies exploring current steering and current focusing stimulation strategies are reviewed, including results of research using computational models, animal neurophysiology, and human psychophysics. Preliminary results of additional neurophysiological and human psychophysical studies are presented that demonstrate the success of current steering strategies in stimulating auditory nerve regions lying between physical CI electrodes, as well as current focusing strategies that excite regions narrower than those stimulated using monopolar configurations. These results are interpreted in the context of perception and speech reception by CI users. Disparities between results of physiological and psychophysical studies are discussed. The differences in stimulation used for physiological and psychophysical studies are hypothesized to contribute to these disparities. Finally, application of current steering and focusing strategies to other types of auditory prostheses is also discussed.

  2. Proposed Schematics and Modeling Results for a Lunar Portable Life Support System

    Science.gov (United States)

    Conger, Bruce; Chullen, Cinda

    2009-01-01

    The Constellation Space Suit Element (CSSE) is an integrated assembly made up of primarily a Pressure Garment System (PGS) and a Portable Life Support System (PLSS). The PLSS is further composed of an oxygen (O2) subsystem, a ventilation subsystem, and a thermal subsystem. This paper baselines a detailed schematic of the CSSE PLSS to provide a basis for current and future CSSE PLSS development efforts. Both context diagrams and detailed schematics describe the hardware components and overall functions for all three of the PLSS subsystems. Additionally, PLSS functions are presented for multiple operational scenarios as follows: 1) Nominal Extravehicular Activity (EVA) Mode; 2) Umbilical Modes; a) No Recharge, b) With Recharge; 3) Decompression Sickness (DCS) Treatment Mode; 4) Buddy Mode; 5) Secondary O2 Modes; a) Helmet Purge; b) Suit Purge; c) Operational; and 5) PLSS Removed Umbilical Mode. A performance modeling effort is being performed to provide a preliminary confirmation of this layout and the current state of the thermal hydraulic modeling efforts being conducted for the PLSS is presented. The goal of these efforts is to provide realistic simulations of the PLSS under various modes of operation. Modeling approaches and assumptions are discussed as well as component model descriptions. Results from the models are included that show PLSS operations at steady-state and transient conditions. Finally, conclusions and recommendations are offered that summarize results, identify PLSS design weaknesses uncovered during review of the analysis results, and propose areas for improvement to increase model fidelity and accuracy.

  3. Current filamentation model for the Weibel/Filamentation instabilities

    Science.gov (United States)

    Ryu, Chang-Mo; Huynh, Cong Tuan; Kim, Chul Min

    2016-10-01

    A current filamentaion model for a nonrelativistic plasma with e +/e- beam has been presented together with PIC simulations, which can explain the mangetic field enhancement during the Weibel/ Filamentation instabilities. This filament model assumes the Hammer-Rostoker equilibrium. In addition, this model predicts preferential acceleration/deceleration for electron-ion plasmas depending on the injected beam to be e +/e-.

  4. Design of permanent magnet eddy current brake for a small scaled electromagnetic launch model

    Science.gov (United States)

    Zhou, Shigui; Yu, Haitao; Hu, Minqiang; Huang, Lei

    2012-04-01

    A variable pole-pitch double-sided permanent magnet (PM) linear eddy current brake (LECB) is proposed for a small scaled electromagnetic launch model. A two-dimensional (2D) analytical steady state model is presented for the double-sided PM-LECB, and the expression for the braking force is derived. Based on the analytical model, the material and eddy current skin effect of the conducting plate are analyzed. Moreover, a variable pole-pitch double-sided PM-LECB is proposed for the effective braking of the moving plate. In addition, the braking force is predicted by finite element (FE) analysis, and the simulated results are in good agreement with the analytical model. Finally, a prototype is presented to test the braking profile for validation of the proposed design.

  5. Models of initiation fatigue crack paths proposed by Macha

    Directory of Open Access Journals (Sweden)

    Z. Marciniak

    2015-10-01

    Full Text Available Professor E. Macha devoted his academic life to solving the problems connected with random multiaxial fatigue in components of machines and structures. In his studies he formulated stress, strain and energy criteria related to critical plane concept. He also proposed several methods to determine critical plane position. In particular, he formulated and verified weight functions applied in order to determine critical plane position. The variance method constituted another significant contribution to the development of methods for determining critical plane position. Apart from these criteria, Macha was exploring energy approach in fatigue of materials and the development of fatigue cracks. He has also observed that strain characteristics multiplied by stress amplitude determined at specimen half-life are applied to estimate fatigue life using energy criteria. However, for cyclically instable materials, stress amplitude value may differ a lot; therefore he proposed the method to determine energy fatigue characteristics directly from experimental research.

  6. Mathematical Modeling of Eddy-Current Loss for a New Induction Heating Device

    Directory of Open Access Journals (Sweden)

    Hai Du

    2014-01-01

    Full Text Available A new induction heating device is presented in this paper. This device can convert mechanical energy into heat energy by utilizing eddy currents, which are induced by rotating permanent magnets. A mathematical model is established for estimating eddy-current loss of the device. The distribution of induced currents and the resultant magnetic field intensity are considered in the process of modeling the eddy-current loss and so is the mutual influence of the electric field between neighborhood pole projection areas. Particularly, the skin effect is considered by correcting the numerical integral domain of eddy current density, which has great effect on the calculating results. Based on specific examples, the effectiveness and correctness of proposed model are proved by finite element analysis. The results show that the mathematical model can provide important reference for design and structure optimization of the device.

  7. Proposing an Environmental Excellence Self-Assessment Model

    DEFF Research Database (Denmark)

    Meulengracht Jensen, Peter; Johansen, John; Wæhrens, Brian Vejrum

    2013-01-01

    This paper presents an Environmental Excellence Self-Assessment (EEA) model based on the structure of the European Foundation of Quality Management Business Excellence Framework. Four theoretical scenarios for deploying the model are presented as well as managerial implications, suggesting...... that the EEA model can be used in global organizations to differentiate environmental efforts depending on the maturity stage of the individual sites. Furthermore, the model can be used to support the decision-making process regarding when organizations should embark on more complex environmental efforts...... to continue to realize excellent environmental results. Finally, a development trajectory for environmental excellence is presented....

  8. 3D mmWave Channel Model Proposal

    DEFF Research Database (Denmark)

    Thomas, Timothy; Nguyen, Huan Cong; R. MacCartney Jr., George

    2014-01-01

    There is growing interest in using millimeter wave (mmWave) frequencies for future access communications based on the enormous amount of available spectrum. To characterize the mmWave channel in urban areas, wideband propagation measurements at 73 GHz have recently been made in New York City. Using...... mmWave channel model is developed with special emphasis on using the ray tracer to determine elevation model parameters. The channel model includes distance-dependent elevation modeling which is critical for the expected 2D arrays which will be employed at mmWave....

  9. Earnings sharing in Social Security: projected impacts of alternative proposals using the MINT model.

    Science.gov (United States)

    Iams, Howard M; Reznik, Gayle L; Tamborini, Christopher R

    2009-01-01

    Changes in American family and work patterns over the past decades have prompted various policy proposals for changing the structure of Social Security benefits. In this article, we use the Social Security Administration's Modeling Income in the Near Term (MINT) microsimulation model to project how Social Security benefit amounts would change in response to incorporating earnings sharing into benefit calculations for the population aged 62 or older in 2030 under three hypothetical policy scenarios. The earnings sharing scenarios modeled in the article would reduce benefits for the majority of individuals, although there are important differences among married, divorced, and widowed individuals. Some groups of men and women would experience increases in Social Security benefits, while some would receive reduced benefits in comparison to current law, particularly widowed individuals. Allowing widows to inherit the earnings records of their deceased husbands would improve their outcomes.

  10. (Process Models of Counselor Judgment: Proposal and Reactions.)

    Science.gov (United States)

    Strohmer, Douglas C.; And Others

    1982-01-01

    Studied competing process models of counselors' clinical judgment for their capacity to account for variance in prognostic judgments and further tested for parsimony. Patton discusses problems of logic and data analysis in the model's formulation. Provides Stromer's response to the critique. (RC)

  11. Evaluating Instructional Design Models: A Proposed Research Approach

    Science.gov (United States)

    Gropper, George L.

    2015-01-01

    Proliferation of prescriptive models in an "engineering" field is not a sign of its maturity. Quite the opposite. Materials engineering, for example, meets the criterion of parsimony. Sadly, the very large number of models in "instructional design," putatively an engineering field, raises questions about its status. Can the…

  12. (Process Models of Counselor Judgment: Proposal and Reactions.)

    Science.gov (United States)

    Strohmer, Douglas C.; And Others

    1982-01-01

    Studied competing process models of counselors' clinical judgment for their capacity to account for variance in prognostic judgments and further tested for parsimony. Patton discusses problems of logic and data analysis in the model's formulation. Provides Stromer's response to the critique. (RC)

  13. Modelling Transformations of Quadratic Functions: A Proposal of Inductive Inquiry

    Science.gov (United States)

    Sokolowski, Andrzej

    2013-01-01

    This paper presents a study about using scientific simulations to enhance the process of mathematical modelling. The main component of the study is a lesson whose major objective is to have students mathematise a trajectory of a projected object and then apply the model to formulate other trajectories by using the properties of function…

  14. Quantum current operators; 3, Commutative quantum current operators semi-infinite construction and functional models

    CERN Document Server

    Ding, J; Ding, Jintai; Feigin, Boris

    1996-01-01

    We construct a commutative current operator $\\bar x^+(z)$ inside $U_q(\\hat{\\frak sl}(2))$. With this operator and the condition of quantum integrability on the quantum current of $U_q(\\hat{\\frak sl}(2))$, we derive the quantization of the semi-infinite construction of integrable modules of The quantization of the functional models for $\\hat{\\frak sl}(2)$ are also given.

  15. A continuum model for current distribution in Rutherford cables

    CERN Document Server

    Akhmedov, A I; Breschi, M

    2001-01-01

    An analysis of eddy currents induced in flat Rutherford-type cables by external time dependent magnetic fields has been performed. The induced currents generate in turn a secondary magnetic field which has a longitudinal periodicity (periodic pattern). The dependence of the amplitude of the pattern on the history of the cable excitation has been investigated. The study has been carried out with two different models for the simulation of current distribution in Rutherford cables, namely a network model, based on a lumped parameters circuit and a "continuum" model, based on a distributed parameters circuit. We show the results of simulations of the current distribution in the inner cable of a short LHC dipole model in different powering conditions and compare them to experimental data. (12 refs).

  16. Cardiac magnetic source imaging based on current multipole model

    Institute of Scientific and Technical Information of China (English)

    Tang Fa-Kuan; Wang Qian; Hua Ning; Lu Hong; Tang Xue-Zheng; Ma Ping

    2011-01-01

    It is widely accepted that the heart current source can be reduced into a current multipole. By adopting three linear inverse methods, the cardiac magnetic imaging is achieved in this article based on the current multipole model expanded to the first order terms. This magnetic imaging is realized in a reconstruction plane in the centre of human heart, where the current dipole array is employed to represent realistic cardiac current distribution. The current multipole as testing source generates magnetic fields in the measuring plane, serving as inputs of cardiac magnetic inverse problem. In the heart-torso model constructed by boundary element method, the current multipole magnetic field distribution is compared with that in the homogeneous infinite space, and also with the single current dipole magnetic field distribution.Then the minimum-norm least-squares (MNLS) method, the optimal weighted pseuDOInverse method (OWPIM), and the optimal constrained linear inverse method (OCLIM) are selected as the algorithms for inverse computation based on current multipole model innovatively, and the imaging effects of these three inverse methods are compared. Besides,two reconstructing parameters, residual and mean residual, are also discussed, and their trends under MNLS, OWPIM and OCLIM each as a function of SNR are obtained and compared.

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

    Science.gov (United States)

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

    2017-03-01

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

  18. Modelling of the ring current in Saturn's magnetosphere

    Science.gov (United States)

    Giampieri, G.; Dougherty, M.

    2004-02-01

    . The existence of a ring current inside Saturn's magnetosphere was first suggested by smith80 and ness81,ness82, in order to explain various features in the magnetic field observations from the Pioneer 11 and Voyager 1 and 2 spacecraft. connerney83 formalized the equatorial current model, based on previous modelling work of Jupiter's current sheet and estimated its parameters from the two Voyager data sets. Here, we investigate the model further, by reconsidering the data from the two Voyager spacecraft, as well as including the Pioneer 11 flyby data set. First, we obtain, in closed form, an analytic expression for the magnetic field produced by the ring current. We then fit the model to the external field, that is the difference between the observed field and the internal magnetic field, considering all the available data. In general, through our global fit we obtain more accurate parameters, compared to previous models. We point out differences between the model's parameters for the three flybys, and also investigate possible deviations from the axial and planar symmetries assumed in the model. We conclude that an accurate modelling of the Saturnian disk current will require taking into account both of the temporal variations related to the condition of the magnetosphere, as well as non-axisymmetric contributions due to local time effects.

  19. Proposal for a new CAPE-OPEN Object Model

    Science.gov (United States)

    Process simulation applications require the exchange of significant amounts of data between the flowsheet environment, unit operation model, and thermodynamic server. Packing and unpacking various data types and exchanging data using structured text-based architectures, including...

  20. From Enneagram to Nine Types Temperament Model: A Proposal

    OpenAIRE

    Yılmaz, Enver Demirel; Gençer, Ali Görkem; Ünal, Özge; Aydemir, Ömer

    2014-01-01

    Temperament, character and personality concepts are addressed by many disciplines that study interpersonal differences. Although each of these concepts is related with each other, they are different and often used instead of one another. Nine Types Temperament Model (NTTM), a new temperament model formulated with the interpretation of Enneagram System, explains the definition, limit, scope and interrelations of these concepts, as well as presents a new perspective on studying the differences ...

  1. 2012 Community Earth System Model (CESM) Tutorial - Proposal to DOE

    Energy Technology Data Exchange (ETDEWEB)

    Holland, Marika [National Center for Atmospheric Research, Boulder, CO (United States); Bailey, David A [National Center for Atmospheric Research, Boulder, CO (United States)

    2013-03-18

    The Community Earth System Model (CESM) is a fully-coupled, global climate model that provides state-of-the-art computer simulations of the Earth's past, present, and future climate states. This document provides the agenda and list of participants for the conference. Web materials for all lectures and practical sessions available from: http://www.cesm.ucar.edu/events/tutorials/073012/ .

  2. Calculation Model for Current-voltage Relation of Silicon Quantum-dots-based Nano-memory

    Institute of Scientific and Technical Information of China (English)

    YANG Hong-guan; DAI Da-kang; YU Biao; SHANG Lin-lin; GUO You-hong

    2007-01-01

    Based on the capacitive coupling formalism, an analytic model for calculating the drain currents of the quantum-dots floating-gate memory cell is proposed. Using this model, one can calculate numerically the drain currents of linear, saturation and subthreshold regions of the device with/without charges stored on the floating dots. The read operation process of an n-channel Si quantum-dots floating-gate nano-memory cell is discussed after calculating the drain currents versus the drain to source voltages and control gate voltages in both high and low threshold states respectively.

  3. Inter-model analysis of tsunami-induced coastal currents

    Science.gov (United States)

    Lynett, Patrick J.; Gately, Kara; Wilson, Rick; Montoya, Luis; Arcas, Diego; Aytore, Betul; Bai, Yefei; Bricker, Jeremy D.; Castro, Manuel J.; Cheung, Kwok Fai; David, C. Gabriel; Dogan, Gozde Guney; Escalante, Cipriano; González-Vida, José Manuel; Grilli, Stephan T.; Heitmann, Troy W.; Horrillo, Juan; Kânoğlu, Utku; Kian, Rozita; Kirby, James T.; Li, Wenwen; Macías, Jorge; Nicolsky, Dmitry J.; Ortega, Sergio; Pampell-Manis, Alyssa; Park, Yong Sung; Roeber, Volker; Sharghivand, Naeimeh; Shelby, Michael; Shi, Fengyan; Tehranirad, Babak; Tolkova, Elena; Thio, Hong Kie; Velioğlu, Deniz; Yalçıner, Ahmet Cevdet; Yamazaki, Yoshiki; Zaytsev, Andrey; Zhang, Y. J.

    2017-06-01

    To help produce accurate and consistent maritime hazard products, the National Tsunami Hazard Mitigation Program organized a benchmarking workshop to evaluate the numerical modeling of tsunami currents. Thirteen teams of international researchers, using a set of tsunami models currently utilized for hazard mitigation studies, presented results for a series of benchmarking problems; these results are summarized in this paper. Comparisons focus on physical situations where the currents are shear and separation driven, and are thus de-coupled from the incident tsunami waveform. In general, we find that models of increasing physical complexity provide better accuracy, and that low-order three-dimensional models are superior to high-order two-dimensional models. Inside separation zones and in areas strongly affected by eddies, the magnitude of both model-data errors and inter-model differences can be the same as the magnitude of the mean flow. Thus, we make arguments for the need of an ensemble modeling approach for areas affected by large-scale turbulent eddies, where deterministic simulation may be misleading. As a result of the analyses presented herein, we expect that tsunami modelers now have a better awareness of their ability to accurately capture the physics of tsunami currents, and therefore a better understanding of how to use these simulation tools for hazard assessment and mitigation efforts.

  4. A mental model proposed to address sustainability and terrorism issues.

    Science.gov (United States)

    Schwing, Richard

    2002-06-01

    I have assembled traditional ways to think about human needs and power along with empirical data to support a mental model of human values. The hierarchy of needs from the world of psychology and the hierarchy of power from the world of diplomacy provide a structure for the model. The empirical data collected from several nations over the last three decades support the structure. Furthermore, an examination of specific trends in this data for specific values indicates that it is not impossible to achieve a sustainable world driven by sustainable values. A world that will be defined by its successful movement toward the "triple bottom line," a term articulated by John Elkington, is a world in which economic prosperity, environmental protection, and social equity are aligned. To say that the model allows one to address terrorism is based on the assumption that the lack of social equity or the perception of that lack determines the likelihood of terrorism.

  5. Modelling of helical current filaments induced by LHW on EAST

    Energy Technology Data Exchange (ETDEWEB)

    Rack, Michael; Denner, Peter; Liang, Yunfeng [Institute of Energy and Climate Research - Plasma Physics, Forschungszentrum Juelich GmbH, Association EURATOM-FZJ, Partner in the Trilateral Euregio Cluster, D-52425 Juelich (Germany); Zeng, Long [Institute of Energy and Climate Research - Plasma Physics, Forschungszentrum Juelich GmbH, Association EURATOM-FZJ, Partner in the Trilateral Euregio Cluster, D-52425 Juelich (Germany); Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Gong, Xianzu; Gan, Kaifu; Wang, Liang; Liu, Fukun; Qian, Jinping; Shen, Biao; Li, Jiangang [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Gauthier, Eric [Association EURATOM-CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Collaboration: the EAST Team

    2013-07-01

    Helical radiation belts have been observed in the scrape-off layer (SOL) of the plasma during the application of lower hybrid wave (LHW) heating at the superconducting tokamak EAST. Modelled SOL field lines, starting in-front of the LHW antennas, show agreement in position and pitch angle to the experimental observed radiation belts. A splitting of the strike-line can be observed on the outer divertor plates during the application of LHW heating. Agreement in the comparison of the Mirnov coil signals and a modelled electric current flow along these SOL field lines was found. A lower hybrid current drive can induce such an electric current flow near the plasma edge. This electric current flow causes a change of the plasma topology which could result in the splitting of the strike-line as known from the application of resonant magnetic perturbation fields. Comparisons of modelled footprint structures and experimental observed heat load patterns in the divertor region are discussed.

  6. Queering Constructs: Proposing a Dynamic Gender and Sexuality Model

    Science.gov (United States)

    Jourian, T. J.

    2015-01-01

    Higher education educators commonly understand social identities, including gender, to be fluid and dynamic. Lev's (2004) model of four components of sexual identity is commonly used to demonstrate the fluidity of sex, gender, and sexuality for individuals, but it does little to address the fixedness of those constructs. Through a multipronged…

  7. Queering Constructs: Proposing a Dynamic Gender and Sexuality Model

    Science.gov (United States)

    Jourian, T. J.

    2015-01-01

    Higher education educators commonly understand social identities, including gender, to be fluid and dynamic. Lev's (2004) model of four components of sexual identity is commonly used to demonstrate the fluidity of sex, gender, and sexuality for individuals, but it does little to address the fixedness of those constructs. Through a multipronged…

  8. Proposing a Metaliteracy Model to Redefine Information Literacy

    Science.gov (United States)

    Jacobson, Trudi E.; Mackey, Thomas P.

    2013-01-01

    Metaliteracy is envisioned as a comprehensive model for information literacy to advance critical thinking and reflection in social media, open learning settings, and online communities. At this critical time in higher education, an expansion of the original definition of information literacy is required to include the interactive production and…

  9. A proposed fractional-order Gompertz model and its application to tumour growth data.

    Science.gov (United States)

    Bolton, Larisse; Cloot, Alain H J J; Schoombie, Schalk W; Slabbert, Jacobus P

    2015-06-01

    A fractional-order Gompertz model of orders between 0 and 2 is proposed. The main purpose of this investigation is to determine whether the ordinary or proposed fractional Gompertz model would best fit our experimental dataset. The solutions for the proposed model are obtained using fundamental concepts from fractional calculus. The closed-form equations of both the proposed model and the ordinary Gompertz model are calibrated using an experimental dataset containing tumour growth volumes of a Rhabdomyosarcoma tumour in a mouse. With regard to the proposed model, the order, within the interval mentioned, that resulted in the best fit to the data was used in a further investigation into the prediction capability of the model. This was compared to the prediction capability of the ordinary Gompertz model. The result of the investigation was that a fractional-order Gompertz model of order 0.68 produced a better fit to our experimental dataset than the well-known ordinary Gompertz model.

  10. Proposing a Formalised Model for Mindful Information Systems Offshoring

    Science.gov (United States)

    Costello, Gabriel J.; Coughlan, Chris; Donnellan, Brian; Gadatsch, Andreas

    The central thesis of this chapter is that mathematical economics can provide a novel approach to the examination of offshoring business decisions and provide an impetus for future research in the area. A growing body of research indicates that projected cost savings from IT offshoring projects are not being met. Furthermore, evidence suggests that decision-making processes have been more emotional than rational, and that many offshoring arrangements have been rushed into without adequate analysis of the true costs involved. Building on the concept of mindfulness and mindlessness introduced to the IS literature by Swanson and Ramiller, a cost equation is developed using “deductive reasoning rather than inductive study” in the tradition of mathematical economics. The model endeavours to capture a wide range of both the quantitative and qualitative parameters. Although the economic model is illustrated against the background of a European scenario, the theoretical framework is generic and applicable to organisations in any global location.

  11. Proposing a model for absorption capacity of technology

    Directory of Open Access Journals (Sweden)

    Hossein Gholizadeh

    2015-01-01

    Full Text Available Absorption capacity of knowledge is the concept which is been introduced in this situation. This phenomenon describes why some countries are in a better condition with a view to technology. Many countries believe that the power to stay in the battle and excel other competitors directly depends on their abilities in taking knowledge. Many countries have used their technological gap with developed countries as an accelerator for improving their absorption capacity. In this study, authors tried to produce a complete definition for absorption capacity through analyzing different research. Then with using expert opinions, a categorization for dimensions of absorption capacity will be prepared by using the structural equation modeling analysis, and finally a model for measuring absorption capacity is suggested. The results show effective dimensions in 5 different section. Studies depict that the most important one is keeping which could be a fundamental for long-term policies of 1404.

  12. Proposing a Metaliteracy Model to Redefine Information Literacy

    Directory of Open Access Journals (Sweden)

    Trudi E. Jacobson

    2013-12-01

    Full Text Available Metaliteracy is envisioned as a comprehensive model for information literacy to advance critical thinking and reflection in social media, open learning settings, and online communities. At this critical time in higher education, an expansion of the original definition of information literacy is required to include the interactive production and sharing of original and repurposed digital materials. Metaliteracy provides an overarching and unifying framework that builds on the core information literacy competencies while addressing the revolutionary changes in how learners communicate, create, and distribute information in participatory environments. Central to the metaliteracy model is a metacognitive component that encourages learners to continuously reflect on their own thinking and literacy development in these fluid and networked spaces. This approach leads to expanded competencies for adapting to the ongoing changes in emerging technologies and for advancing critical thinking and empowerment for producing, connecting, and distributing information as independent and collaborative learners.

  13. Modelling and simulation of the ice melting process on a current-carrying conductor

    Energy Technology Data Exchange (ETDEWEB)

    Peter, Z.

    2006-07-01

    Mathematical models were developed to determine the current and energy requirements for thermal de-icing and ice prevention on overhead power transmission lines. The models were based on the Joule effect under various meteorological and current transmission conditions. The minimum current intensity required to inhibit ice formation on a single power line conductor was determined. Correction factors were then introduced for 3 specific aluminum conductors with steel reinforcement (ACSRs). Water runback on the conductor surface was considered as well as deviation of the water layer from the thermal equilibrium state. Model results were in good agreement with measurements taken in an icing research wind tunnel. The overall heat transfer coefficient (HTC) for stranded conductors was then assessed to complete the model. A computational model using finite differences was also developed to calculate the current and energy requirements for de-icing partially ice covered conductors. Joule heating by AC current and impulse current were the 2 heating techniques analyzed. Thermal conductivity of the ACSR conductor was also estimated. Experimentally validated analytical approaches were proposed to determine the shedding time and corresponding energy required to de-ice a completely ice covered conductor by heating with increased nominal AC current. It was concluded that ice accretion on a single power line can be prevented using the experimentally validated mathematical models that calculate the current and energy requirements of de-icing conductors.

  14. PROPOSAL OF AN EMPIRICAL MODEL FOR SUPPLIERS SELECTION

    Directory of Open Access Journals (Sweden)

    Paulo Ávila

    2015-03-01

    Full Text Available The problem of selecting suppliers/partners is a crucial and important part in the process of decision making for companies that intend to perform competitively in their area of activity. The selection of supplier/partner is a time and resource-consuming task that involves data collection and a careful analysis of the factors that can positively or negatively influence the choice. Nevertheless it is a critical process that affects significantly the operational performance of each company. In this work, trough the literature review, there were identified five broad suppliers selection criteria: Quality, Financial, Synergies, Cost, and Production System. Within these criteria, it was also included five sub-criteria. Thereafter, a survey was elaborated and companies were contacted in order to answer which factors have more relevance in their decisions to choose the suppliers. Interpreted the results and processed the data, it was adopted a model of linear weighting to reflect the importance of each factor. The model has a hierarchical structure and can be applied with the Analytic Hierarchy Process (AHP method or Simple Multi-Attribute Rating Technique (SMART. The result of the research undertaken by the authors is a reference model that represents a decision making support for the suppliers/partners selection process.

  15. Merging imagery and models for river current prediction

    Science.gov (United States)

    Blain, Cheryl Ann; Linzell, Robert S.; McKay, Paul

    2011-06-01

    To meet the challenge of operating in river environments with denied access and to improve the riverine intelligence available to the warfighter, advanced high resolution river circulation models are combined with remote sensing feature extraction algorithms to produce a predictive capability for currents and water levels in rivers where a priori knowledge of the river environment is limited. A River Simulation Tool (RST) is developed to facilitate the rapid configuration of a river model. River geometry is extracted from the automated processing of available imagery while minimal user input is collected to complete the parameter and forcing specifications necessary to configure a river model. Contingencies within the RST accommodate missing data such as a lack of water depth information and allow for ensemble computations. Successful application of the RST to river environments is demonstrated for the Snohomish River, WA. Modeled currents compare favorably to in-situ currents reinforcing the value of the developed approach.

  16. A Neuron Model Based Ultralow Current Sensor System for Bioapplications

    Directory of Open Access Journals (Sweden)

    A. K. M. Arifuzzman

    2016-01-01

    Full Text Available An ultralow current sensor system based on the Izhikevich neuron model is presented in this paper. The Izhikevich neuron model has been used for its superior computational efficiency and greater biological plausibility over other well-known neuron spiking models. Of the many biological neuron spiking features, regular spiking, chattering, and neostriatal spiny projection spiking have been reproduced by adjusting the parameters associated with the model at hand. This paper also presents a modified interpretation of the regular spiking feature in which the firing pattern is similar to that of the regular spiking but with improved dynamic range offering. The sensor current ranges between 2 pA and 8 nA and exhibits linearity in the range of 0.9665 to 0.9989 for different spiking features. The efficacy of the sensor system in detecting low amount of current along with its high linearity attribute makes it very suitable for biomedical applications.

  17. MODEL STUDY OF THE DOUBLE FED MACHINE WITH CURRENT CONTROL

    Directory of Open Access Journals (Sweden)

    A. S. Lyapin

    2016-07-01

    Full Text Available The paper deals with modeling results of the double fed induction machine with current control in the rotor circuit. We show the most promising applications of electric drives on the basis of the double fed induction machine and their advantages. We present and consider functional scheme of the electric drive on the basis of the double fed induction machine with current control. Equations are obtained for creation of such machine mathematical model. Expressions for vector projections of rotor current are given. According to the obtained results, the change of the vector projections of rotor current ensures operation of the double fed induction machine with the specified values of active and reactive stator power throughout the variation range of sliding motion. We consider static characteristics of double fed machine with current control. Energy processes proceeding in the machine are analyzed. We confirm the operationpossibility of double fed induction machine with current controlin the rotor circuit with given values of active and reactive stator power. The presented results can be used for creation of mathematical models and static characteristics of double fed machines with current control of various capacities.

  18. Flavour-changing neutral currents in models with extra ' boson

    Indian Academy of Sciences (India)

    S Sahoo; L Maharana

    2004-09-01

    New neutral gauge bosons ' are the features of many models addressing the physics beyond the standard model. Together with the existence of new neutral gauge bosons, models based on extended gauge groups (rank > 4) often predict new charged fermions also. A mixing of the known fermions with new states, with exotic weak-isospin assignments (left-handed singlets and right-handed doublets) will induce tree-level flavour-changing neutral interactions mediated by exchange, while if the mixing is only with new states with ordinary weak-isospin assignments, the flavour-changing neutral currents are mainly due to the exchange of the new neutral gauge boson '. We review flavour-changing neutral currents in models with extra ' boson. Then we discuss some flavour-changing processes forbidden in the standard model and new contributions to standard model processes.

  19. Modeling the Inner Magnetosphere: Radiation Belts, Ring Current, and Composition

    Science.gov (United States)

    Glocer, Alex

    2011-01-01

    The space environment is a complex system defined by regions of differing length scales, characteristic energies, and physical processes. It is often difficult, or impossible, to treat all aspects of the space environment relative to a particular problem with a single model. In our studies, we utilize several models working in tandem to examine this highly interconnected system. The methodology and results will be presented for three focused topics: 1) Rapid radiation belt electron enhancements, 2) Ring current study of Energetic Neutral Atoms (ENAs), Dst, and plasma composition, and 3) Examination of the outflow of ionospheric ions. In the first study, we use a coupled MHD magnetosphere - kinetic radiation belt model to explain recent Akebono/RDM observations of greater than 2.5 MeV radiation belt electron enhancements occurring on timescales of less than a few hours. In the second study, we present initial results of a ring current study using a newly coupled kinetic ring current model with an MHD magnetosphere model. Results of a dst study for four geomagnetic events are shown. Moreover, direct comparison with TWINS ENA images are used to infer the role that composition plays in the ring current. In the final study, we directly model the transport of plasma from the ionosphere to the magnetosphere. We especially focus on the role of photoelectrons and and wave-particle interactions. The modeling methodology for each of these studies will be detailed along with the results.

  20. Assessment of current and proposed nature reserves of Mexico based on their capacity to protect geophysical features and biodiversity

    Science.gov (United States)

    Cantu, C.; Wright, R.G.; Scott, J.M.; Strand, Espen

    2004-01-01

    Mexico currently has 144 nature reserves covering approximately 9.1% of its land area. These reserves were established for a variety of reasons - often unrelated to the protection of biodiversity. In 2000 in response to a growing concern about the lack of organized conservation reserve planning to protect the important threatened biological and physical features of Mexico, the Mexican Commission for Knowledge and Use of Biodiversity (CONABIO) proposed the establishment of 151 new reserves for Mexico covering 51,429,500 ha. We compiled a GIS analysis using digital thematic maps of physical and biological features to examine how the existing and proposed reserves serve to protect the biodiversity and physical features of the country. Using a conservation target of placing a minimum of 12% of the land area of each important biophysical feature in nature reserves, we found that the 144 existing nature reserves covering 18 million ha (9% of the country) only meet that target for elevation ranges >3000 m and areas with poor soils. These mountainous areas represent less than 1% of the country. The gaps in the existing nature reserves network occur mainly at lower and intermediate elevations (ecosystems, and high productivity soils. The areas proposed by CONABIO increase the proportion of protected lands in the country to over 27% and most of the conservation targets for geophysical features, and land cover, categories are met. Whether this area would be sufficient to maintain viable populations and ecological integrity of species and ecosystems is unknown. Even with the new reserves, low elevation coastal lands would be below the conservation target in the nature reserves. To include a representative sample of these lands would be difficult as these are the same areas where the majority of people live. ?? 2003 Elsevier Ltd. All rights reserved.

  1. Neural Network based Modeling and Simulation of Transformer Inrush Current

    Directory of Open Access Journals (Sweden)

    Puneet Kumar Singh

    2012-05-01

    Full Text Available Inrush current is a very important phenomenon which occurs during energization of transformer at no load due to temporary over fluxing. It depends on several factors like magnetization curve, resistant and inductance of primary winding, supply frequency, switching angle of circuit breaker etc. Magnetizing characteristics of core represents nonlinearity which requires improved nonlinearity solving technique to know the practical behavior of inrush current. Since several techniques still working on modeling of transformer inrush current but neural network ensures exact modeling with experimental data. Therefore, the objective of this study was to develop an Artificial Neural Network (ANN model based on data of switching angle and remanent flux for predicting peak of inrush current. Back Propagation with Levenberg-Marquardt (LM algorithm was used to train the ANN architecture and same was tested for the various data sets. This research work demonstrates that the developed ANN model exhibits good performance in prediction of inrush current’s peak with an average of percentage error of -0.00168 and for modeling of inrush current with an average of percentage error of -0.52913.

  2. Multiscale modeling to evaluate proposed space-based Doppler lidar sampling strategies

    Science.gov (United States)

    Emmitt, G. D.

    1985-01-01

    A proposal has been made to place a pulsed Doppler lidar on a space platform (Huffaker, et al., 1980; Emmitt, 1982) in a low earth orbit (200 to 800 km) to measure the atmospheric winds with a spatial resolution commensurate with the current continental rawinsonde network density - i.e., 300 to 500 km resolution. In the case of the space-based doppler lidar, the full range of space scales applies. Single shot pulses with dimensions of 10 x 1000 meters are used to sample areas 100,000 x 100,000 meters to resolved mass flow structure with wavelength of 1 million meters. Simulation studies, therefore, require an equally broad range of atmospheric models. A general circulation model is appropriate to answer questions regarding the impact of a global wind measuring system upon synoptic forecasts. Since the nominal resolution of the spacebased system is expected to be a few 100's of kilometers, then a numerical model with mesoscale dynamics is required. The meaning of an average Doppler shift within a laser pulse volume must be evaluated with models of turbulent/convective scale motions and aerosol gradients. Examples of how models on all these scales have been applied in an ongoing simulation study are presented. In particular, the uncertainties in a mesoscale wind estimate are separated into those arising from pulse scale variances and those due to sample distribution within a prescribed resolution volume. Trade-offs between accuracy and representativeness are discussed in terms of the model results.

  3. Performance assessment modeling of the proposed Genting Island repository facility

    Energy Technology Data Exchange (ETDEWEB)

    Imardjoko, Y.U. [Gadjah Mada Univ., Yogyakarta (Indonesia); Bullen, D.B. [Iowa State Univ., Ames, IA (United States); Yatim, S. [National Atomic Energy Agency, Tangerang (Indonesia)

    1996-12-01

    Indonesia is about to enter the nuclear era with the construction of several nuclear power plants in the near future. Numerous issues, including disposal of high-level radioactive wastes, must be addressed to evaluate the impact of these plants on the environment. This paper reviews the Genting ocean island repository site development plan with respect to three main areas, the inventory of HLRW, the barrier systems (natural and engineered), and the physical condition of the site. The radionuclide inventory and waste form require analyses of the waste package that include selection of container materials, the type of engineered barrier and its predicted performance, and radionuclide release models. Parameters pertinent to the repository site includes information pertaining to the geology, hydrology, climatology, and water chemistry of the site. These data are important to aid in the prediction of the long-term performance of the site.

  4. Meson Exchange Current (MEC) Models in Neutrino Interaction Generators

    CERN Document Server

    Katori, Teppei

    2013-01-01

    Understanding of the so-called 2 particle-2 hole (2p-2h) effect is an urgent program in neutrino interaction physics for current and future oscillation experiments. Such processes are believed to be responsible for the event excesses observed by recent neutrino experiments. The 2p-2h effect is dominated by the meson exchange current (MEC), and is accompanied by a 2-nucleon emission from the primary vertex, instead of a single nucleon emission from the charged-current quasi-elastic (CCQE) interaction. Current and future high resolution experiments can potentially nail down this effect. For this reason, there are world wide efforts to model and implement this process in neutrino interaction simulations. In these proceedings, I would like to describe how this channel is modeled in neutrino interaction generators.

  5. Modeling and Controller Design of PV Micro Inverter without Using Electrolytic Capacitors and Input Current Sensors

    Directory of Open Access Journals (Sweden)

    Faa Jeng Lin

    2016-11-01

    Full Text Available This paper outlines the modeling and controller design of a novel two-stage photovoltaic (PV micro inverter (MI that eliminates the need for an electrolytic capacitor (E-cap and input current sensor. The proposed MI uses an active-clamped current-fed push-pull DC-DC converter, cascaded with a full-bridge inverter. Three strategies are proposed to cope with the inherent limitations of a two-stage PV MI: (i high-speed DC bus voltage regulation using an integrator to deal with the 2nd harmonic voltage ripples found in single-phase systems; (ii inclusion of a small film capacitor in the DC bus to achieve ripple-free PV voltage; (iii improved incremental conductance (INC maximum power point tracking (MPPT without the need for current sensing by the PV module. Simulation and experimental results demonstrate the efficacy of the proposed system.

  6. Community Benchmarking of Tsunami-Induced Nearshore Current Models

    Science.gov (United States)

    Lynett, P. J.; Wilson, R. I.; Gately, K.

    2015-12-01

    To help produce accurate and consistent maritime hazard products, the National Tsunami Hazard Mitigation Program (NTHMP) Strategic Plan includes a requirement to develop and run a benchmarking workshop to evaluate the numerical tsunami modeling of currents. For this workshop, five different benchmarking datasets were organized. These datasets were selected based on characteristics such as geometric complexity, currents that are shear/separation driven (and thus are de-coupled from the incident wave forcing), tidal coupling, and interaction with the built environment. While tsunami simulation models have generally been well validated against wave height and runup, comparisons with speed data are much less common. As model results are increasingly being used to estimate or indicate damage to coastal infrastructure, understanding the accuracy and precision of speed predictions becomes of important. As a result of this 2-day workshop held in early 2015, modelers now have a better awareness of their ability to accurately capture the physics of tsunami currents, and therefore a better understanding of how to use these simulation tools for hazard assessment and mitigation efforts. In this presentation, the model results - from 14 different modelers - will be presented and summarized, with a focus on statistical and ensemble properties of the current predictions.

  7. Probability of detection models for eddy current NDE methods

    Energy Technology Data Exchange (ETDEWEB)

    Rajesh, S.N.

    1993-04-30

    The development of probability of detection (POD) models for a variety of nondestructive evaluation (NDE) methods is motivated by a desire to quantify the variability introduced during the process of testing. Sources of variability involved in eddy current methods of NDE include those caused by variations in liftoff, material properties, probe canting angle, scan format, surface roughness and measurement noise. This thesis presents a comprehensive POD model for eddy current NDE. Eddy current methods of nondestructive testing are used widely in industry to inspect a variety of nonferromagnetic and ferromagnetic materials. The development of a comprehensive POD model is therefore of significant importance. The model incorporates several sources of variability characterized by a multivariate Gaussian distribution and employs finite element analysis to predict the signal distribution. The method of mixtures is then used for estimating optimal threshold values. The research demonstrates the use of a finite element model within a probabilistic framework to the spread in the measured signal for eddy current nondestructive methods. Using the signal distributions for various flaw sizes the POD curves for varying defect parameters have been computed. In contrast to experimental POD models, the cost of generating such curves is very low and complex defect shapes can be handled very easily. The results are also operator independent.

  8. Noninvasive transcranial direct current stimulation in a genetic absence model

    NARCIS (Netherlands)

    Zobeiri, M.; Luijtelaar, E.L.J.M. van

    2013-01-01

    The proposed area of onset for absence epilepsy characteristic of spontaneously occurring spike and slow-wave discharges (SWDs) in the genetic absence rat model is the subgranular layer of the somatosensory cortex. Modulation of the hyperexcitable cortical foci by bilateral transcranial direct curre

  9. A PROPOSED HYBRID AGILE FRAMEWORK MODEL FOR MOBILE APPLICATIONS DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    Ammar Khader Almasri

    2016-03-01

    Full Text Available With the increasing in mobile application systems and a high competition between companies, that led to increase in the number of mobile application projects. Mobile software development is a group of process for creating software for mobile devices with limited resources like small screen, low-power. The development of mobile applications is a big challenging because of rapidly changing business requirements and technical constraints for mobile systems. So, developers faced the challenge of a dynamic environment and the Changing of mobile application requirements. Moreover, Mobile applications should adapt appropriate software development methods that act in response efficiently to these challenges. However, at the moment, there is limited knowledge about the suitability of different software practices for the development of mobile applications. According to many researchers ,Agile methodologies was found to be most suitable for mobile development projects as they are short time, require flexibility, reduces waste and time to market. Finally, in this research we are looking for a suitable process model that conforms to the requirement of mobile application, we are going to investigate agile development methods to find a way, making the development of mobile application easy and compatible with mobile device features.

  10. A proposed model of e-trust for electronic banking

    Directory of Open Access Journals (Sweden)

    Neda Yousefi

    2015-11-01

    Full Text Available Customer’s trust is the most important and one of the key factors of success in e-commerce. However, trust is the essential aspects of e-banking adoption and the main element for building long-term relationships with the bank's customers. So the purpose of this research is to investigate the factors influencing on customer′s trust in e-banking services and prioritize them. Therefore, designed questionnaire was distributed among 177 electronic service customers in number of banks in the city of Karaj, Iran. Likert quintuplet scales were used to measure the variables. After collecting the questionnaires, the data were analyzed by structural equation modeling (by using LISREL 8.5. The results revealed that quality of electronic services such as ease of use, privacy and security, individual characteristics of customers such as disposition to trust and features of bank such as reputation, size and dependence on government, have had the greatest effect on customer′s trust in e-banking services.

  11. Micromagnetic modeling of critical current oscillations in magnetic Josephson junctions

    Science.gov (United States)

    Golovchanskiy, I. A.; Bol'ginov, V. V.; Stolyarov, V. S.; Abramov, N. N.; Ben Hamida, A.; Emelyanova, O. V.; Stolyarov, B. S.; Kupriyanov, M. Yu.; Golubov, A. A.; Ryazanov, V. V.

    2016-12-01

    In this work we propose and explore an effective numerical approach for investigation of critical current dependence on applied magnetic field for magnetic Josephson junctions with in-plane magnetization orientation. This approach is based on micromagnetic simulation of the magnetization reversal process in the ferromagnetic layer with introduced internal magnetic stiffness and subsequent reconstruction of the critical current value using total flux or reconstructed actual phase difference distribution. The approach is flexible and shows good agreement with experimental data obtained on Josephson junctions with ferromagnetic barriers. Based on this approach we have obtained a critical current dependence on applied magnetic field for rectangular magnetic Josephson junctions with high size aspect ratio. We have shown that the rectangular magnetic Josephson junctions can be considered for application as an effective Josephson magnetic memory element with the value of critical current defined by the orientation of magnetic moment at zero magnetic field. An impact of shape magnetic anisotropy on critical current is revealed and discussed. Finally, we have considered a curling magnetic state in the ferromagnetic layer and demonstrated its impact on critical current.

  12. Operational prediction of rip currents using numerical model and nearshore bathymetry from video images

    Science.gov (United States)

    Sembiring, L.; Van Ormondt, M.; Van Dongeren, A. R.; Roelvink, J. A.

    2017-07-01

    Rip currents are one of the most dangerous coastal hazards for swimmers. In order to minimize the risk, a coastal operational-process based-model system can be utilized in order to provide forecast of nearshore waves and currents that may endanger beach goers. In this paper, an operational model for rip current prediction by utilizing nearshore bathymetry obtained from video image technique is demonstrated. For the nearshore scale model, XBeach1 is used with which tidal currents, wave induced currents (including the effect of the wave groups) can be simulated simultaneously. Up-to-date bathymetry will be obtained using video images technique, cBathy 2. The system will be tested for the Egmond aan Zee beach, located in the northern part of the Dutch coastline. This paper will test the applicability of bathymetry obtained from video technique to be used as input for the numerical modelling system by comparing simulation results using surveyed bathymetry and model results using video bathymetry. Results show that the video technique is able to produce bathymetry converging towards the ground truth observations. This bathymetry validation will be followed by an example of operational forecasting type of simulation on predicting rip currents. Rip currents flow fields simulated over measured and modeled bathymetries are compared in order to assess the performance of the proposed forecast system.

  13. Analytical Model for Voltage-Dependent Photo and Dark Currents in Bulk Heterojunction Organic Solar Cells

    OpenAIRE

    2016-01-01

    A physics-based explicit mathematical model for the external voltage-dependent forward dark current in bulk heterojunction (BHJ) organic solar cells is developed by considering Shockley-Read-Hall (SRH) recombination and solving the continuity equations for both electrons and holes. An analytical model for the external voltage-dependent photocurrent in BHJ organic solar cells is also proposed by incorporating exponential photon absorption, dissociation efficiency of bound electron-hole pairs (...

  14. Numerical modeling of 3D halo current path in ITER structures

    Energy Technology Data Exchange (ETDEWEB)

    Bettini, Paolo; Marconato, Nicolò; Furno Palumbo, Maurizio; Peruzzo, Simone [Consorzio RFX, EURATOM-ENEA Association, C.so Stati Uniti 4, 35127 Padova (Italy); Specogna, Ruben, E-mail: ruben.specogna@uniud.it [DIEGM, Università di Udine, Via delle Scienze, 208, 33100 Udine (Italy); Albanese, Raffaele; Rubinacci, Guglielmo; Ventre, Salvatore; Villone, Fabio [Consorzio CREATE, EURATOM-ENEA Association, Via Claudio 21, 80125 Napoli (Italy)

    2013-10-15

    Highlights: ► Two numerical codes for the evaluation of halo currents in 3D structures are presented. ► A simplified plasma model is adopted to provide the input (halo current injected into the FW). ► Two representative test cases of ITER symmetric and asymmetric VDEs have been analyzed. ► The proposed approaches provide results in excellent agreement for both cases. -- Abstract: Disruptions represent one of the main concerns for Tokamak operation, especially in view of fusion reactors, or experimental test reactors, due to the electro-mechanical loads induced by halo and eddy currents. The development of a predictive tool which allows to estimate the magnitude and spatial distribution of the halo current forces is of paramount importance in order to ensure robust vessel and in-vessel component design. With this aim, two numerical codes (CARIDDI, CAFE) have been developed, which allow to calculate the halo current path (resistive distribution) in the passive structures surrounding the plasma. The former is based on an integral formulation for the eddy currents problem particularized to the static case; the latter implements a pair of 3D FEM complementary formulations for the solution of the steady-state current conduction problem. A simplified plasma model is adopted to provide the inputs (halo current injected into the first wall). Two representative test cases (ITER symmetric and asymmetric VDEs) have been selected to cross check the results of the proposed approaches.

  15. A Summary of Proposed Changes to the Current ICARTT Format Standards and their Implications to Future Airborne Studies

    Science.gov (United States)

    Northup, E. A.; Kusterer, J.; Quam, B.; Chen, G.; Early, A. B.; Beach, A. L., III

    2015-12-01

    The current ICARTT file format standards were developed for the purpose of fulfilling the data management needs for the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) campaign in 2004. The goal of the ICARTT file format was to establish a common and simple to use data file format to promote data exchange and collaboration among science teams with similar science objectives. ICARTT has been the NASA standard since 2010, and is widely used by NOAA, NSF, and international partners (DLR, FAAM). Despite its level of acceptance, there are a number of issues with the current ICARTT format, especially concerning the machine readability. To enhance usability, the ICARTT Refresh Earth Science Data Systems Working Group (ESDSWG) was established to enable a platform for atmospheric science data producers, users (e.g. modelers) and data managers to collaborate on developing criteria for this file format. Ultimately, this is a cross agency effort to improve and aggregate the metadata records being produced. After conducting a survey to identify deficiencies in the current format, we determined which are considered most important to the various communities. Numerous recommendations were made to improve upon the file format while maintaining backward compatibility. The recommendations made to date and their advantages and limitations will be discussed.

  16. Efficient Estimation for Semiparametric Varying Coefficient Partially Linear Regression Models with Current Status Data

    Institute of Scientific and Technical Information of China (English)

    Tao Hu; Heng-jian Cui; Xing-wei Tong

    2009-01-01

    This article considers a semiparametric varying-coefficient partially linear regression model with current status data. The semiparametric varying-coefficient partially linear regression model which is a gen-eralization of the partially linear regression model and varying-coefficient regression model that allows one to explore the possibly nonlinear effect of a certain covariate on the response variable. A Sieve maximum likelihood estimation method is proposed and the asymptotic properties of the proposed estimators are discussed. Under some mild conditions, the estimators are shown to be strongly consistent. The convergence rate of the estima-tor for the unknown smooth function is obtained and the estimator for the unknown parameter is shown to be asymptotically efficient and normally distributed. Simulation studies are conducted to examine the small-sample properties of the proposed estimates and a real dataset is used to illustrate our approach.

  17. One-Dimensional Modelling of Marine Current Turbine Runaway Behaviour

    Directory of Open Access Journals (Sweden)

    Staffan Lundin

    2016-04-01

    Full Text Available If a turbine loses its electrical load, it will rotate freely and increase speed, eventually achieving that rotational speed which produces zero net torque. This is known as a runaway situation. Unlike many other types of turbine, a marine current turbine will typically overshoot the final runaway speed before slowing down and settling at the runaway speed. Since the hydrodynamic forces acting on the turbine are dependent on rotational speed and acceleration, turbine behaviour during runaway becomes important for load analyses during turbine design. In this article, we consider analytical and numerical models of marine current turbine runaway behaviour in one dimension. The analytical model is found not to capture the overshoot phenomenon, while still providing useful estimates of acceleration at the onset of runaway. The numerical model incorporates turbine wake build-up and predicts a rotational speed overshoot. The predictions of the models are compared against measurements of runaway of a marine current turbine. The models are also used to recreate previously-published results for a tidal turbine and applied to a wind turbine. It is found that both models provide reasonable estimates of maximum accelerations. The numerical model is found to capture the speed overshoot well.

  18. Comparison of analytical eddy current models using principal components analysis

    Science.gov (United States)

    Contant, S.; Luloff, M.; Morelli, J.; Krause, T. W.

    2017-02-01

    Monitoring the gap between the pressure tube (PT) and the calandria tube (CT) in CANDU® fuel channels is essential, as contact between the two tubes can lead to delayed hydride cracking of the pressure tube. Multifrequency transmit-receive eddy current non-destructive evaluation is used to determine this gap, as this method has different depths of penetration and variable sensitivity to noise, unlike single frequency eddy current non-destructive evaluation. An Analytical model based on the Dodd and Deeds solutions, and a second model that accounts for normal and lossy self-inductances, and a non-coaxial pickup coil, are examined for representing the response of an eddy current transmit-receive probe when considering factors that affect the gap response, such as pressure tube wall thickness and pressure tube resistivity. The multifrequency model data was analyzed using principal components analysis (PCA), a statistical method used to reduce the data set into a data set of fewer variables. The results of the PCA of the analytical models were then compared to PCA performed on a previously obtained experimental data set. The models gave similar results under variable PT wall thickness conditions, but the non-coaxial coil model, which accounts for self-inductive losses, performed significantly better than the Dodd and Deeds model under variable resistivity conditions.

  19. Study on model current predictive control method of PV grid- connected inverters systems with voltage sag

    Science.gov (United States)

    Jin, N.; Yang, F.; Shang, S. Y.; Tao, T.; Liu, J. S.

    2016-08-01

    According to the limitations of the LVRT technology of traditional photovoltaic inverter existed, this paper proposes a low voltage ride through (LVRT) control method based on model current predictive control (MCPC). This method can effectively improve the photovoltaic inverter output characteristics and response speed. The MCPC method of photovoltaic grid-connected inverter designed, the sum of the absolute value of the predictive current and the given current error is adopted as the cost function with the model predictive control method. According to the MCPC, the optimal space voltage vector is selected. Photovoltaic inverter has achieved automatically switches of priority active or reactive power control of two control modes according to the different operating states, which effectively improve the inverter capability of LVRT. The simulation and experimental results proves that the proposed method is correct and effective.

  20. Accurate and fast table look-up models for leakage current analysis in 65 nm CMOS technology

    Institute of Scientific and Technical Information of China (English)

    薛冀颖; 李涛; 余志平

    2009-01-01

    Novel physical models for leakage current analysis in 65 nm technology are proposed. Taking into con-sideration the process variations and emerging effects in nano-scaled technology, the presented models are capable of accurately estimating the subthreshold leakage current and junction tunneling leakage current in 65 nm technol-ogy. Based on the physical models, new table look-up models are developed and first applied to leakage current analysis in pursuit of higher simulation speed. Simulation results show that the novel physical models are in ex-cellent agreement with the data measured from the foundry in the 65 nm process, and the proposed table look-up models can provide great computational efficiency by using suitable interpolation techniques. Compared with the traditional physical-based models, the table look-up models can achieve 2.5X speedup on average on a variety of industry circuits.

  1. Current Concepts: Mouse Models of Sjögren's Syndrome

    Directory of Open Access Journals (Sweden)

    Tegan N. Lavoie

    2011-01-01

    Full Text Available Sjögren's syndrome (SjS is a complex chronic autoimmune disease of unknown etiology which primarily targets the exocrine glands, resulting in eventual loss of secretory function. The disease can present as either primary SjS or secondary SjS, the latter of which occurs concomitantly with another autoimmune disease such as rheumatoid arthritis, systemic lupus erythematosus, scleroderma, or primary biliary cirrhosis. Current advancements in therapeutic prevention and treatment for SjS are impeded by lack of understanding in the pathophysiological and clinical progression of the disease. Development of appropriate mouse models for both primary and secondary SjS is needed in order to advance knowledge of this disease. This paper details important features, advantages, and pitfalls of current animal models of SjS, including spontaneous, transgenic, knockout, immunization, and transplantation chimera mouse models, and emphasizes the need for a better model in representing the human SjS phenotype.

  2. Animal models of frailty: current applications in clinical research.

    Science.gov (United States)

    Kane, Alice E; Hilmer, Sarah N; Mach, John; Mitchell, Sarah J; de Cabo, Rafael; Howlett, Susan E

    2016-01-01

    The ethical, logistical, and biological complications of working with an older population of people inherently limits clinical studies of frailty. The recent development of animal models of frailty, and tools for assessing frailty in animal models provides an invaluable opportunity for frailty research. This review summarizes currently published animal models of frailty including the interleukin-10 knock-out mouse, the mouse frailty phenotype assessment tool, and the mouse clinical frailty index. It discusses both current and potential roles of these models in research into mechanisms of frailty, interventions to prevent/delay frailty, and the effect of frailty on outcomes. Finally, this review discusses some of the challenges and opportunities of translating research findings from animals to humans.

  3. Numeral eddy current sensor modelling based on genetic neural network

    Institute of Scientific and Technical Information of China (English)

    Yu A-Long

    2008-01-01

    This paper presents a method used to the numeral eddy current sensor modelling based on the genetic neural network to settle its nonlinear problem. The principle and algorithms of genetic neural network are introduced. In this method, the nonlinear model parameters of the numeral eddy current sensor are optimized by genetic neural network (GNN) according to measurement data. So the method remains both the global searching ability of genetic algorithm and the good local searching ability of neural network. The nonlinear model has the advantages of strong robustness,on-line modelling and high precision.The maximum nonlinearity error can be reduced to 0.037% by using GNN.However, the maximum nonlinearity error is 0.075% using the least square method.

  4. Thermal analytic model of current gain for bipolar junction transistor-bipolar static induction transistor compound device

    Institute of Scientific and Technical Information of China (English)

    Zhang You-Run; Zhang Bo; Li Ze-Hong; Lai Chang-Jin; Li Zhao-Ji

    2009-01-01

    This paper proposes a thermal analytical model of current gain for bipolar junction transistor-bipolar static induction transistor (BJT-BSIT) compound device in the low current operation. It also proposes a best thermal compensating factor to the compound device that indicates the relationship between the thermal variation rate of current gain and device structure. This is important for the design of compound device to be optimized. Finally, the analytical model is found to be in good agreement with numerical simulation and experimental results. The test results demonstrate that thermal variation rate of current gain is below 10% in 25℃C-85℃ and 20% in -55℃-25℃.

  5. A qualitative model for strategic analysis of organizations. Application and alternative proposal on a study case

    Directory of Open Access Journals (Sweden)

    Santiago Ferro Moreno

    2015-12-01

    Full Text Available The strategic analysis of organizations is based on the internal and external environments, in order to identify positive and negative variables and factors. The interrelation and timing of these strategic forces are essential to create alternative solutions that tend to achieve the organizational objectives.The normative prospective has theorical and methodological foundations to create a desired future and from it, be able to identify impelling and restraining forces that have influence on the particular problematic situation (go from the current situation to a better one in a certain time.The aim of this article is to analyze on a strategic way a real case with a normative-prospective model that considers the temporal dynamics of the factors impact and variables in time allowing to suggest alternative solutions.Semi-structured interviews were performed with all the employees of this case and structured observations and workshops with the commercial and general management.In consequence, with the results, the desired, current and improved situations were built. Additionally, forces were identified classified and appreciated and lastly solutions were suggested. With the proposed prospective method, alternative solutions could be constructed in order to settle temporary organizational objectives. No constraints were found to use the current method in other cases.Keywords: Strategic forces, Normative prospective, Problematic situations, Strategies

  6. Modeling and strain gauging of eddy current repulsion deicing systems

    Science.gov (United States)

    Smith, Samuel O.

    1993-01-01

    Work described in this paper confirms and extends work done by Zumwalt, et al., on a variety of in-flight deicing systems that use eddy current repulsion for repelling ice. Two such systems are known as electro-impulse deicing (EIDI) and the eddy current repulsion deicing strip (EDS). Mathematical models for these systems are discussed for their capabilities and limitations. The author duplicates a particular model of the EDS. Theoretical voltage, current, and force results are compared directly to experimental results. Dynamic strain measurements results are presented for the EDS system. Dynamic strain measurements near EDS or EIDI coils are complicated by the high magnetic fields in the vicinity of the coils. High magnetic fields induce false voltage signals out of the gages.

  7. Current fluctuations in a two dimensional model of heat conduction

    Science.gov (United States)

    Pérez-Espigares, Carlos; Garrido, Pedro L.; Hurtado, Pablo I.

    2011-03-01

    In this work we study numerically and analytically current fluctuations in the two-dimensional Kipnis-Marchioro-Presutti (KMP) model of heat conduction. For that purpose, we use a recently introduced algorithm which allows the direct evaluation of large deviations functions. We compare our results with predictions based on the Hydrodynamic Fluctuation Theory (HFT) of Bertini and coworkers, finding very good agreement in a wide interval of current fluctuations. We also verify the existence of a well-defined temperature profile associated to a given current fluctuation which depends exclusively on the magnitude of the current vector, not on its orientation. This confirms the recently introduced Isometric Fluctuation Relation (IFR), which results from the time-reversibility of the dynamics, and includes as a particular instance the Gallavotti-Cohen fluctuation theorem in this context but adds a completely new perspective on the high level of symmetry imposed by timereversibility on the statistics of nonequilibrium fluctuations.

  8. Common-Cause Failure Treatment in Event Assessment: Basis for a Proposed New Model

    Energy Technology Data Exchange (ETDEWEB)

    Dana Kelly; Song-Hua Shen; Gary DeMoss; Kevin Coyne; Don Marksberry

    2010-06-01

    Event assessment is an application of probabilistic risk assessment in which observed equipment failures and outages are mapped into the risk model to obtain a numerical estimate of the event’s risk significance. In this paper, we focus on retrospective assessments to estimate the risk significance of degraded conditions such as equipment failure accompanied by a deficiency in a process such as maintenance practices. In modeling such events, the basic events in the risk model that are associated with observed failures and other off-normal situations are typically configured to be failed, while those associated with observed successes and unchallenged components are assumed capable of failing, typically with their baseline probabilities. This is referred to as the failure memory approach to event assessment. The conditioning of common-cause failure probabilities for the common cause component group associated with the observed component failure is particularly important, as it is insufficient to simply leave these probabilities at their baseline values, and doing so may result in a significant underestimate of risk significance for the event. Past work in this area has focused on the mathematics of the adjustment. In this paper, we review the Basic Parameter Model for common-cause failure, which underlies most current risk modelling, discuss the limitations of this model with respect to event assessment, and introduce a proposed new framework for common-cause failure, which uses a Bayesian network to model underlying causes of failure, and which has the potential to overcome the limitations of the Basic Parameter Model with respect to event assessment.

  9. Current Models and Innovative Strategies in Management Education in China.

    Science.gov (United States)

    Wang, Zhong-Ming

    1999-01-01

    Current models of management education in China include national training, on-the-job technical training, and the national master's of business administration supervisory committee. Effective strategies being used include teamwork, process skills, action learning, cross-cultural management learning, and competency-based management development. (SK)

  10. Hypersonic Vehicle Tracking Based on Improved Current Statistical Model

    Directory of Open Access Journals (Sweden)

    He Guangjun

    2013-11-01

    Full Text Available A new method of tracking the near space hypersonic vehicle is put forward. According to hypersonic vehicles’ characteristics, we improved current statistical model through online identification of the maneuvering frequency. A Monte Carlo simulation is used to analyze the performance of the method. The results show that the improved method exhibits very good tracking performance in comparison with the old method.

  11. Gompertz kinetics model of fast chemical neurotransmission currents.

    Science.gov (United States)

    Easton, Dexter M

    2005-10-01

    At a chemical synapse, transmitter molecules ejected from presynaptic terminal(s) bind reversibly with postsynaptic receptors and trigger an increase in channel conductance to specific ions. This paper describes a simple but accurate predictive model for the time course of the synaptic conductance transient, based on Gompertz kinetics. In the model, two simple exponential decay terms set the rates of development and decline of transmitter action. The first, r, triggering conductance activation, is surrogate for the decelerated rate of growth of conductance, G. The second, r', responsible for Y, deactivation of the conductance, is surrogate for the decelerated rate of decline of transmitter action. Therefore, the differential equation for the net conductance change, g, triggered by the transmitter is dg/dt=g(r-r'). The solution of that equation yields the product of G(t), representing activation, and Y(t), which defines the proportional decline (deactivation) of the current. The model fits, over their full-time course, published records of macroscopic ionic current associated with fast chemical transmission. The Gompertz model is a convenient and accurate method for routine analysis and comparison of records of synaptic current and putative transmitter time course. A Gompertz fit requiring only three independent rate constants plus initial current appears indistinguishable from a Markov fit using seven rate constants.

  12. [Neither Descartes nor Freud? current pain models in psychosomatic medicine].

    Science.gov (United States)

    Egloff, N; Egle, U T; von Känel, R

    2008-05-14

    Models explaining chronic pain based on the mere presence or absence of peripheral somatic findings or which view pain of psychological origin when there is no somatic explanation, have their shortcomings. Current scientific knowledge calls for distinct pain concepts, which integrate neurobiological and neuropsychological aspects of pain processing.

  13. Limitations Of The Current State Space Modelling Approach In Multistage Machining Processes Due To Operation Variations

    Science.gov (United States)

    Abellán-Nebot, J. V.; Liu, J.; Romero, F.

    2009-11-01

    The State Space modelling approach has been recently proposed as an engineering-driven technique for part quality prediction in Multistage Machining Processes (MMP). Current State Space models incorporate fixture and datum variations in the multi-stage variation propagation, without explicitly considering common operation variations such as machine-tool thermal distortions, cutting-tool wear, cutting-tool deflections, etc. This paper shows the limitations of the current State Space model through an experimental case study where the effect of the spindle thermal expansion, cutting-tool flank wear and locator errors are introduced. The paper also discusses the extension of the current State Space model to include operation variations and its potential benefits.

  14. A proposed simulation optimization model framework for emergency department problems in public hospital

    Science.gov (United States)

    Ibrahim, Ireen Munira; Liong, Choong-Yeun; Bakar, Sakhinah Abu; Ahmad, Norazura; Najmuddin, Ahmad Farid

    2015-12-01

    The Emergency Department (ED) is a very complex system with limited resources to support increase in demand. ED services are considered as good quality if they can meet the patient's expectation. Long waiting times and length of stay is always the main problem faced by the management. The management of ED should give greater emphasis on their capacity of resources in order to increase the quality of services, which conforms to patient satisfaction. This paper is a review of work in progress of a study being conducted in a government hospital in Selangor, Malaysia. This paper proposed a simulation optimization model framework which is used to study ED operations and problems as well as to find an optimal solution to the problems. The integration of simulation and optimization is hoped can assist management in decision making process regarding their resource capacity planning in order to improve current and future ED operations.

  15. Performance Modeling of Proposed GUISET Middleware for Mobile Healthcare Services in E-Marketplaces

    Directory of Open Access Journals (Sweden)

    Alaba Olu Akingbesote

    2014-01-01

    Full Text Available GUISET is a proposed middleware engine currently under study in South Africa. The goal is to provide utility services for small, medium, and macroenterprises in the context of mobile e-services. Three things are important to make this engine effective and efficient: the implementation, performance, and the pricing strategy. The literature has delved richly into implementation issue of similar projects. Both the performance and the pricing strategy issues have not been fully discussed especially in the context of mobile healthcare services. Some literature has addressed the performance issue using the exogenous nonpriority and the preemptive model. However, with providers offering different services using that approach may prove to be difficult to implement. This work extends existing and widely adopted theories to non-preemptive model by using the queuing theory and the simulation model in the context of mobile healthcare services. Our evaluation is based on non-preemptive priority and nonpriority discipline. Our results reveal that the unconditional average waiting time remains the same with reduction in waiting time over the non-preemptive priority model in four out of the five classes observed. This is envisaged to be beneficial in mobile healthcare services where events are prioritized and urgent attention is needed to be given to urgent events.

  16. Cognitive mechanisms of mindfulness: A test of current models.

    Science.gov (United States)

    Isbel, Ben; Mahar, Doug

    2015-12-15

    Existing models of mindfulness describe the self-regulation of attention as primary, leading to enhanced decentering and ability to access and override automatic cognitive processes. This study compared 23 experienced and 21 non-meditators on tests of mindfulness, attention, decentering, and ability to override automatic cognitive processes to test the cognitive mechanisms proposed to underlie mindfulness practice. Experienced meditators had significantly higher mindfulness and decentering than non-meditators. No significant difference between groups was found on measures of attention or ability to override automatic processes. These findings support the prediction that mindfulness leads to enhanced decentering, but do not support the cognitive mechanisms proposed to underlie such enhancement. Since mindfulness practice primarily involves internally directed attention, it may be the case that cognitive tests requiring externally directed attention and timed responses do not accurately assess mindfulness-induced cognitive changes. Implications for the models of mindfulness and future research are discussed.

  17. Semiparametric analysis of incomplete current status outcome data under transformation models.

    Science.gov (United States)

    Wen, Chi-Chung; Chen, Yi-Hau

    2014-06-01

    This work, motivated by an osteoporosis survey study, considers regression analysis with incompletely observed current status data. Here the current status data, including an examination time and an indicator for whether or not the event of interest has occurred by the examination time, is not observed for all subjects. Instead, a surrogate outcome subject to misclassification of the current status is available for all subjects. We focus on semiparametric regression under transformation models, including the proportional hazards and proportional odds models as special cases. Under the missing at random mechanism where the missingness of the current status outcome can depend only on the observed surrogate outcome and covariates, we propose an approach of validation likelihood based on the likelihood from the validation subsample where the data are fully observed, with adjustments of the probability of observing the current status outcome, as well as the distribution of the surrogate outcome in the validation subsample. We propose an efficient computation algorithm for implementation, and derive consistency and asymptotic normality for inference with the proposed estimator. The application to the osteoporosis survey data and simulations reveal that the validation likelihood performs well; it removes the bias from the "complete case" analysis discarding subjects with missing data, and achieves higher efficiency than the inverse probability weighting analysis.

  18. Numerical Model for Conduction-Cooled Current Lead Heat Loads

    CERN Document Server

    White, M J; Brueck, H D; 10.1063/1.4706965

    2012-01-01

    Current leads are utilized to deliver electrical power from a room temperature junction mounted on the vacuum vessel to a superconducting magnet located within the vacuum space of a cryostat. There are many types of current leads used at laboratories throughout the world, however, conduction-cooled current leads are often chosen for their simplicity and reliability. Conduction-cooled leads have the advantage of using common materials, have no superconducting/normal state transition, and have no boil-off vapor to collect. The XFEL (X-Ray Free Electron Laser) magnets are operated at 2 K, which makes vapor-cooled current leads impractical due to the sub-atmospheric bath pressure. This paper presents a numerical model for conduction-cooled current lead heat loads. This model takes into account varying material and fluid thermal properties, varying thicknesses along the length of the lead, heat transfer in the circumferential and longitudinal directions, electrical power dissipation, and the effect of thermal inte...

  19. 78 FR 38091 - Airworthiness Criteria: Proposed Airship Design Criteria for Lockheed Martin Aeronautics Model...

    Science.gov (United States)

    2013-06-25

    ...] Airworthiness Criteria: Proposed Airship Design Criteria for Lockheed Martin Aeronautics Model LMZ1M Airship... on the proposed design criteria for the Lockheed Martin Aeronautics model LMZ1M airship. On March 12.... The LMZ1M is a manned cargo lifting hybrid airship incorporating a number of advanced features. The...

  20. Survey of NoC and Programming Models Proposals for MPSoC

    Directory of Open Access Journals (Sweden)

    Eduard Fernandez-Alonso

    2012-03-01

    Full Text Available The aim of this paper is to give briefing of the concept of network-on-chip and programming model topics on multiprocessors system-on-chip world, an attractive and relatively new field for academia. Numerous proposals from academia and industry are selected to highlight the evolution of the implementation approaches both on NoC proposals and on programming models proposals.

  1. Model-aided Navigation with Sea Current Estimation for an Autonomous Underwater Vehicle

    Directory of Open Access Journals (Sweden)

    Alain Martinez

    2015-07-01

    Full Text Available This paper presents a strategy to improve the navigation solution of the HRC-AUV by deploying a model-aided inertial navigation system (MA-INS. Based on a simpler three-DOF linear dynamic model (DM of the vehicle, and implemented through a Kalman filter (KF, the performance of the proposed MA-INS is compared to state-of-the-art solutions based on non-linear models. The model allows the online estimation of the sea current parameters before and during the navigation mission. Qualitative and quantitative evaluations as well as a statistical significance test are performed using both simulated and real data, demonstrating the usefulness of the proposed model-aided navigation.

  2. Model-Aided Navigation with Sea Current Estimation for an Autonomous Underwater Vehicle

    Directory of Open Access Journals (Sweden)

    Alain Martinez

    2015-07-01

    Full Text Available This paper presents a strategy to improve the navigation solution of the HRC-AUV by deploying a model-aided inertial navigation system (MA-INS. Based on a simpler three-DOF linear dynamic model (DM of the vehicle, and implemented through a Kalman filter (KF, the performance of the proposed MA-INS is compared to state-of-the-art solutions based on non-linear models. The model allows the online estimation of the sea current parameters before and during the navigation mission. Qualitative and quantitative evaluations as well as a statistical significance test are performed using both simulated and real data, demonstrating the usefulness of the proposed model-aided navigation.

  3. A fluid mechanical model for current-generating-feeding jellyfish

    Science.gov (United States)

    Peng, Jifeng; Dabiri, John

    2008-11-01

    Many jellyfish species, e.g. moon jellyfish Aurelia aurita, use body motion to generate fluid currents which carry their prey to the vicinity of their capture appendages. In this study, a model was developed to understand the fluid mechanics for this current-generating-feeding mode of jellyfish. The flow generated by free-swimming Aurelia aurita was measured using digital particle image velocimetry. The dynamics of prey (e.g., brine shrimp Artemia) in the flow field were described by a modified Maxey-Riley equation which takes into consideration the inertia of prey and the escape forces, which prey exert in the presence of predator. A Lagrangian analysis was used to identify the region of the flow in which prey can be captured by the jellyfish and the clearance rate was quantified. The study provides a new methodology to study biological current-generating-feeding and the transport and mixing of particles in fluid flow in general.

  4. 3-dimensional current collection model. [of Tethered Satellite System 1

    Science.gov (United States)

    Hwang, Kai-Shen; Shiah, A.; Wu, S. T.; Stone, N.

    1992-01-01

    A three-dimensional, time dependent current collection model of a satellite has been developed for the TSS-1 system. The system has been simulated particularly for the Research of Plasma Electrodynamics (ROPE) experiment. The Maxwellian distributed particles with the geomagnetic field effects are applied in this numerical simulation. The preliminary results indicate that a ring current is observed surrounding the satellite in the equatorial plane. This ring current is found between the plasma sheath and the satellite surface and is oscillating with a time scale of approximately 1 microsec. This is equivalent to the electron plasma frequency. An hour glass shape of electron distribution was observed when the viewing direction is perpendicular to the equatorial plane. This result is consistent with previous findings from Linson (1969) and Antoniades et al. (1990). Electrons that are absorbed by the satellite are limited from the background ionosphere as indicated by Parker and Murphy (1967).

  5. A question of balance: a proposal for new mouse models of autism.

    Science.gov (United States)

    Murcia, Crystal L; Gulden, Forrest; Herrup, Karl

    2005-01-01

    Autism spectrum disorder (ASD) represents a major mental health problem with estimates of prevalence ranging from 1/500 to 1/2000. While generally recognized as developmental in origin, little to nothing is certain about its etiology. Currently, diagnosis is made on the basis of a variety of early developmental delays and/or regressions in behavior. There are no universally agreed upon changes in brain structure or cell composition. No biomarkers of any type are available to aid or confirm the clinical diagnosis. In addition, while estimates of the heritability of the condition range from 60 to 90%, as of this writing no disease gene has been unequivocally identified. The prevalence of autism is three- to four-fold higher in males than in females, but the reason for this sexual dimorphism is unknown. In light of all of these ambiguities, a proposal to discuss potential animal models may seem the heart of madness. However, parsing autism into its individual genetic, behavioral, and neurobiological components has already facilitated a 'conversation' between the human disease and the neuropathology and biochemistry underlying the disorder. Building on these results, it should be possible to not just replicate one aspect of autism but to connect the developmental abnormalities underlying the ultimate behavioral phenotype. A reciprocal conversation such as this, wherein the human disease informs on how to make a better animal model and the animal model teaches of the biology causal to autism, would be highly beneficial.

  6. A proposed-standard format to represent and distribute tomographic models and other earth spatial data

    Science.gov (United States)

    Postpischl, L.; Morelli, A.; Danecek, P.

    2009-04-01

    Formats used to represent (and distribute) tomographic earth models differ considerably and are rarely self-consistent. In fact, each earth scientist, or research group, uses specific conventions to encode the various parameterizations used to describe, e.g., seismic wave speed or density in three dimensions, and complete information is often found in related documents or publications (if available at all) only. As a consequence, use of various tomographic models from different authors requires considerable effort, is more cumbersome than it should be and prevents widespread exchange and circulation within the community. We propose a format, based on modern web standards, able to represent different (grid-based) model parameterizations within the same simple text-based environment, easy to write, to parse, and to visualise. The aim is the creation of self-describing data-structures, both human and machine readable, that are automatically recognised by general-purpose software agents, and easily imported in the scientific programming environment. We think that the adoption of such a representation as a standard for the exchange and distribution of earth models can greatly ease their usage and enhance their circulation, both among fellow seismologists and among a broader non-specialist community. The proposed solution uses semantic web technologies, fully fitting the current trends in data accessibility. It is based on Json (JavaScript Object Notation), a plain-text, human-readable lightweight computer data interchange format, which adopts a hierarchical name-value model for representing simple data structures and associative arrays (called objects). Our implementation allows integration of large datasets with metadata (authors, affiliations, bibliographic references, units of measure etc.) into a single resource. It is equally suited to represent other geo-referenced volumetric quantities — beyond tomographic models — as well as (structured and unstructured

  7. An Equivalent Circuit Modeling of Discharge Current Injected in Contact with an ESD-gun

    Science.gov (United States)

    Fujiwara, Osamu; Tanaka, Hideyuki; Yamanaka, Yukio

    The transient electromagnetic (EM) fields caused by an electrostatic discharge (ESD) have broadband frequency spectra, which cause serious failure to high-tech information equipment. From this perspective, an ESD testing for the EM immunity of the equipment is specified by the IEC 61000-4-2, in which the detailed waveform of the discharge current injected onto the IEC recommended Pellegrini target in contact with an ESD-gun is prescribed for calibration. However, the factors for determining the current waveform remain unclear, and thus the IEC prescribed current waveform is unlikely to be injected into actual equipment. In this study, based on the structure of an ESD-gun, an equivalent circuit modeling is proposed for analyzing the discharge current injected onto a 50-Ω SMA connector instead of the IEC target that has frequency-dependent transmission characteristics. Its validity is confirmed by comparing the calculated current waveform with the measured result. The proposed circuit modeling is also validated from measurement of the discharge current injected onto a transmission-line by the ESD-gun.

  8. Empirical Evaluation of the Proposed eXScrum Model: Results of a Case Study

    CERN Document Server

    Qureshi, M Rizwan Jameel

    2012-01-01

    Agile models promote fast development. XP and Scrum are the most widely used agile models. This paper investigates the phases of XP and Scrum models in order to identify their potentials and drawbacks. XP model has certain drawbacks, such as not suitable for maintenance projects and poor performance for medium and large-scale development projects. Scrum model has certain limitations, such as lacked in engineering practices. Since, both XP and Scrum models contain good features and strengths but still there are improvement possibilities in these models. Majority of the software development companies are reluctant to switch from traditional methodologies to agile methodologies for development of industrial projects. A fine integration, of software management of the Scrum model and engineering practices of XP model, is very much required to accumulate the strengths and remove the limitations of both models. This is achieved by proposing an eXScrum model. The proposed model is validated by conducting a controlled...

  9. Charge and Current in the Quantum Hall Matrix Model

    OpenAIRE

    2003-01-01

    We extend the quantum Hall matrix model to include couplings to external electric and magnetic fields. The associated current suffers from matrix ordering ambiguities even at the classical level. We calculate the linear response at low momenta -- this is unambigously defined. In particular, we obtain the correct fractional quantum Hall conductivity, and the expected density modulations in response to a weak and slowly varying magnetic field. These results show that the classical quantum Hall ...

  10. Considering digits in a current model of numerical development.

    Science.gov (United States)

    Roesch, Stephanie; Moeller, Korbinian

    2014-01-01

    Numerical cognition has long been considered the perfect example of abstract information processing. Nevertheless, there is accumulating evidence in recent years suggesting that the representation of number magnitude may not be entirely abstract but may present a specific case of embodied cognition rooted in the sensory and bodily experiences of early finger counting and calculating. However, so far none of the existing models of numerical development considers the influence of finger-based representations. Therefore, we make first suggestions on (i) how finger-based representations may be integrated into a current model of numerical development; and (ii) how they might corroborate the acquisition of basic numerical competencies at different development levels.

  11. Modeling the heliospheric current sheet: Solar cycle variations

    Science.gov (United States)

    Riley, Pete; Linker, J. A.; Mikić, Z.

    2002-07-01

    In this report we employ an empirically driven, three-dimensional MHD model to explore the evolution of the heliospheric current sheet (HCS) during the course of the solar cycle. We compare our results with a simpler ``constant-speed'' approach for mapping the HCS outward into the solar wind to demonstrate that dynamic effects can substantially deform the HCS in the inner heliosphere (ballerina skirt,'' we discuss an interval approaching the maximum of solar cycle 23 (Carrington rotations 1960 and 1961) when the shape would be better described as ``conch shell''-like. We use Ulysses magnetic field measurements to support the model results.

  12. Pion electromagnetic current in a light-front model

    CERN Document Server

    Pacheco-Bicudo-Cabral de Melo, J; Frederico, T

    1999-01-01

    The electromagnetic form factor of the pion is calculated in a pseudoscalar field theoretical model which constituent quarks. We extract the form factor using the "+" component of the electromagnetic current in the light-cone formalism. For comparison, we also compute the form factor in the covariant framework and we obtain perfect agreement. It is shown that the pair terms do not contribute in this pseudoscalar model. This explains why a naive light-cone calculation, i.e., omitting pair terms from the onset, also yields the same results.

  13. Current state of genome-scale modeling in filamentous fungi

    DEFF Research Database (Denmark)

    Brandl, Julian; Andersen, Mikael Rørdam

    2015-01-01

    The group of filamentous fungi contains important species used in industrial biotechnology for acid, antibiotics and enzyme production. Their unique lifestyle turns these organisms into a valuable genetic reservoir of new natural products and biomass degrading enzymes that has not been used to full...... testing them in vivo. The increasing availability of high quality models and molecular biological tools for manipulating filamentous fungi renders the model-guided engineering of these fungal factories possible with comprehensive metabolic networks. A typical fungal model contains on average 1138 unique...... metabolic reactions and 1050 ORFs, making them a vast knowledge-base of fungal metabolism. In the present review we focus on the current state as well as potential future applications of genome-scale models in filamentous fungi....

  14. Persistent current in an almost staggered Harper model

    Science.gov (United States)

    Vasserman, A.; Berkovits, R.

    2015-08-01

    In this paper we study the persistent current (PC) of a staggered Harper model, close to the half-filling. The Harper model is different than other one dimensional disordered systems which are always localized, since it is a quasi-periodic system with correlated disorder resulting in the fact that it can be in the metallic regime. Nevertheless, the PC for a wide range of parameters of the Harper model does not show typical metallic behavior, although the system is in the metallic regime. This is a result of the nature of the central band states, which are a hybridization of Gaussian states localized in superlattice points. When the superlattice is not commensurate with the system length, the PC behaves as an insulator. Thus even in the metallic regime a typical finite Harper model may exhibit a PC expected from an insulator.

  15. Modeling Electric Current Flow in 3D Fractured Media

    Science.gov (United States)

    Demirel, S.; Roubinet, D.; Irving, J.

    2014-12-01

    The study of fractured rocks is extremely important in a variety of research fields and applications such as hydrogeology, hydrocarbon extraction and long-term storage of toxic waste. As fractures are highly conductive structures in comparison to the surrounding rock, their presence can be either an advantage or a drawback. For hydrocarbon extraction, fractures allow for quick and easy access to the resource whereas for toxic waste storage their presence increases the risk of leakage and migration of pollutants. In both cases, the identification of fracture network characteristics is an essential step. Recently, we have developed an approach for modeling electric current flow in 2D fractured media. This approach is based on a discrete-dual-porosity model where fractures are represented explicitly, the matrix is coarsely discretized into blocks, and current flow exchange between the fractures and matrix is analytically evaluated at the fracture-scale and integrated at the block-scale [1]. Although this approach has shown much promise and has proven its efficiency for 2D simulations, its extension to 3D remains to be addressed. To this end, we assume that fractures can be represented as two-dimensional finite planes embedded in the surrounding matrix, and we express analytically the distribution of electric potential at the fracture scale. This fracture-scale expression takes into account the electric-current-flow exchange with the surrounding matrix and flow conservation is enforced at the fracture intersections. The fracture-matrix exchange is then integrated at the matrix-block scale where the electric current flow conservation at the block boundaries is formulated with a modified finite volume method. With the objective of providing a low-computational-cost modeling approach adapted to 3D simulations in fractured media, our model is (i) validated and compared to existing modeling approaches and, (ii) used to evaluate the impact of the presence of fractures on

  16. Current Practice in Measuring the Quality of Conceptual Models:Challenges and Research%Current Practice in Measuring the Quality of Conceptual Models:Challenges and Research

    Institute of Scientific and Technical Information of China (English)

    LIU Lei; WU Yu-feng; LI Xiao-jun

    2012-01-01

    How to measure the quality of conceptual models is an important issue in the IS field and related research. This paper conducts a review of research in measuring conceptual model quality and identifies the major theoretical and practical issues that need to be addressed in future studies. We review current classification frameworks for conceptual model quality and practice of measuring conceptual model quality. Based on the review, challenges for studies of measuring the quality of conceptual models are proposed and these challenges are also research points which should be strengthened in future studies.

  17. Homology Modeling a Fast Tool for Drug Discovery: Current Perspectives

    Science.gov (United States)

    Vyas, V. K.; Ukawala, R. D.; Ghate, M.; Chintha, C.

    2012-01-01

    Major goal of structural biology involve formation of protein-ligand complexes; in which the protein molecules act energetically in the course of binding. Therefore, perceptive of protein-ligand interaction will be very important for structure based drug design. Lack of knowledge of 3D structures has hindered efforts to understand the binding specificities of ligands with protein. With increasing in modeling software and the growing number of known protein structures, homology modeling is rapidly becoming the method of choice for obtaining 3D coordinates of proteins. Homology modeling is a representation of the similarity of environmental residues at topologically corresponding positions in the reference proteins. In the absence of experimental data, model building on the basis of a known 3D structure of a homologous protein is at present the only reliable method to obtain the structural information. Knowledge of the 3D structures of proteins provides invaluable insights into the molecular basis of their functions. The recent advances in homology modeling, particularly in detecting and aligning sequences with template structures, distant homologues, modeling of loops and side chains as well as detecting errors in a model contributed to consistent prediction of protein structure, which was not possible even several years ago. This review focused on the features and a role of homology modeling in predicting protein structure and described current developments in this field with victorious applications at the different stages of the drug design and discovery. PMID:23204616

  18. Evaluation of models proposed for the 1991 revision of the International Geomagnetic Reference Field

    Science.gov (United States)

    Peddie, N.W.

    1992-01-01

    The 1991 revision of the International Geomagnetic Reference Field (IGRF) comprises a definitive main-field model for 1985.0, a main-field model for 1990.0, and a forecast secular-variation model for the period 1990-1995. The five 1985.0 main-field models and five 1990.0 main-field models that were proposed have been evaluated by comparing them with one another, with magnetic observatory data, and with Project MAGNET aerial survey data. The comparisons indicate that the main-field models proposed by IZMIRAN, and the secular-variation model proposed jointly by the British Geological Survey and the US Naval Oceanographic Office, should be assigned relatively lower weight in the derivation of the new IGRF models. -Author

  19. A physical surface-potential-based drain current model for polysilicon thin-film transistors

    Institute of Scientific and Technical Information of China (English)

    Li Xiyue; Deng Wanling; Huang Junkai

    2012-01-01

    A physical drain current model of polysilicon thin-film transistors based on the charge-sheet model,the density of trap states and surface potential is proposed.The model uses non-iterative calculations,which are single-piece and valid in all operation regions above flat-band voltage.The distribution of the trap states,including both Gaussian deep-level states and exponential band-tail states,is also taken into account,and parameter extraction of trap state distribution is developed by the optoelectronic modulation spectroscopy measurement method.Comparisons with the available experimental data are accomplished,and good agreements are obtained.

  20. An induction machine model including interbar currents for studying performances during transients and steady state

    Energy Technology Data Exchange (ETDEWEB)

    Razik, H. [Universite Henri Poincare, GREEN, CNRS-UMR 7037, BP 239, F-54506 Vandoeuvre-les-Nancy Cedex (France); Henao, H. [University of Picardie, CREA, 33 rue Saint Leu, F-80039 Amiens Cedex 1 (France); Carlson, R. [GRUCAD/CTC/UFSC, Campus Universitario, C.P. 436, Florianopolis - SC, 88040-900 (Brazil)

    2009-01-15

    This paper presents a mathematical model of a three-phase induction motor taking into consideration the interbar contacts. Several models have been available in the references. However, they consider the rotor of the induction motor as being constituted either a three-phase or a squirrel cage even if it operates under stator and/or rotor faults condition. Nonetheless, the contact between a bar and the iron core for the machine has to be considered, especially when a rotor fault occurs. It is obvious that rotor currents are under the influence of rotor constitution materials. So, the paper aim's concerns a transient model of the induction motors which can consider the rotor broken bars defect. Despite its increasing complexity, it could be able to provide with useful indications for diagnostic purposes. This model is advocated for the simulation of motors behavior under rotor defect which takes into account the interbar currents. The proposed technique is based on the mesh model analysis of the squirrel cage. As low power induction motors are prevalent in industrial plants, we pay a special attention on them. Notwithstanding, additional currents are due to the contact between the non-insulated bar constituting the squirrel cage to the rotor iron core. The monitoring of induction motors is predominantly made through the stator current analysis of the motor when it operates at nominal condition. Moreover, this one is observed in steady state operating system, knowing that the motor is generally fed by a sinusoidal supply. Consequently, simulation results showed in this paper prove the effectiveness of the proposed approach, and the impact of interbar resistance both on the model and the line current spectrum for the diagnostic. An experimental test proves the effectiveness of this model. (author)

  1. Simulation of current generation in a 3-D plasma model

    Energy Technology Data Exchange (ETDEWEB)

    Tsung, F.S.; Dawson, J.M. [Univ. of California, Los Angeles, CA (United States)

    1996-12-31

    Two wires carrying current in the same direction will attract each other, and two wires carrying current in the opposite direction will repel each other. Now, consider a test charge in a plasma. If the test charge carries current parallel to the plasma, then it will be pulled toward the plasma core, and if the test charge carries current anti-parallel to the plasma, then it will be pushed to the edge. The electromagnetic coupling between the plasma and a test charge (i.e., the A{sub {parallel}} {circ} v{sub {parallel}} term in the test charge`s Hamiltonian) breaks the symmetry in the parallel direction, and gives rise to a diffusion coefficient which is dependent on the particle`s parallel velocity. This is the basis for the {open_quotes}preferential loss{close_quotes} mechanism described in the work by Nunan et al. In our previous 2+{1/2}D work, in both cylindrical and toroidal geometries, showed that if the plasma column is centrally fueled, then an initial current increases steadily. The results in straight, cylindrical plasmas showed that self generated parallel current arises without trapped particle or neoclassical diffusion, as assumed by the bootstrap theory. It suggests that the fundamental mechanism seems to be the conservation of particles canonical momenta in the direction of the ignorable coordinate. We have extended the simulation to 3D to verify the model put forth. A scalable 3D EM-PIC code, with a localized field-solver, has been implemented to run on a large class of parallel computers. On the 512-node SP2 at Cornell Theory Center, we have benchmarked the 2+{1/2}D calculations using 32 grids in the previously ignored direction, and a 100-fold increase in the number of particles. Our preliminary results show good agreements between the 2+{1/2}D and the 3D calculations. We will present our 3D results at the meeting.

  2. Modeling of leakage currents in high-k dielectrics

    Energy Technology Data Exchange (ETDEWEB)

    Jegert, Gunther Christian

    2012-03-15

    Leakage currents are one of the major bottlenecks impeding the downscaling efforts of the semiconductor industry. Two core devices of integrated circuits, the transistor and, especially, the DRAM storage capacitor, suffer from the increasing loss currents. In this perspective a fundamental understanding of the physical origin of these leakage currents is highly desirable. However, the complexity of the involved transport phenomena so far has prevented the development of microscopic models. Instead, the analysis of transport through the ultra-thin layers of high-permittivity (high-k) dielectrics, which are employed as insulating layers, was carried out at an empirical level using simple compact models. Unfortunately, these offer only limited insight into the physics involved on the microscale. In this context the present work was initialized in order to establish a framework of microscopic physical models that allow a fundamental description of the transport processes relevant in high-k thin films. A simulation tool that makes use of kinetic Monte Carlo techniques was developed for this purpose embedding the above models in an environment that allows qualitative and quantitative analyses of the electronic transport in such films. Existing continuum approaches, which tend to conceal the important physics behind phenomenological fitting parameters, were replaced by three-dimensional transport simulations at the level of single charge carriers. Spatially localized phenomena, such as percolation of charge carriers across pointlike defects, being subject to structural relaxation processes, or electrode roughness effects, could be investigated in this simulation scheme. Stepwise a self-consistent, closed transport model for the TiN/ZrO{sub 2} material system, which is of outmost importance for the semiconductor industry, was developed. Based on this model viable strategies for the optimization of TiN/ZrO{sub 2}/TiN capacitor structures were suggested and problem areas

  3. Semiparametric Additive Transformation Model under Current Status Data

    CERN Document Server

    Cheng, Guang

    2011-01-01

    We consider the efficient estimation of the semiparametric additive transformation model with current status data. A wide range of survival models and econometric models can be incorporated into this general transformation framework. We apply the B-spline approach to simultaneously estimate the linear regression vector, the nondecreasing transformation function, and a set of nonparametric regression functions. We show that the parametric estimate is semiparametric efficient in the presence of multiple nonparametric nuisance functions. An explicit consistent B-spline estimate of the asymptotic variance is also provided. All nonparametric estimates are smooth, and shown to be uniformly consistent and have faster than cubic rate of convergence. Interestingly, we observe the convergence rate interfere phenomenon, i.e., the convergence rates of B-spline estimators are all slowed down to equal the slowest one. The constrained optimization is not required in our implementation. Numerical results are used to illustra...

  4. Competency-Based University Undergraduate Teaching Management: Proposal for a Conceptual Model

    Directory of Open Access Journals (Sweden)

    Rodolfo Schmal

    2005-12-01

    Full Text Available The human resources societies and their organizations can count on are more and more relevant. In that sense, a major challenge faced by universities is to give students the appropriate background to be professionals with the profile the current scenario requires. This article focuses the management of university careers. Historically, many careers have emphasized knowledge, especially abstract knowledge. Today, the trend is to address aspects that reach beyond cognition, and focus the attention in effective competencies that include procedures and attitudes. Such approach allows the opportunity of defining a holistic management of careers, reaching beyond the sheer teaching of disciplines. Concurrently, the availability of information methods and tools will contribute for the definition and implementation of a design process that can work with explicit criteria and transformations. The article proposes a conceptual model to represent the objects, and their attributes and associations that are considered of interest for the management of university teaching under a competency focus. A second stage should implement such model through the construction of an information system that supports the management of corresponding careers.

  5. Modeling of finite aspect ratio effects on current drive

    Energy Technology Data Exchange (ETDEWEB)

    Wright, J.C.; Phillips, C.K. [Princeton Plasma Physics Lab., NJ (United States)

    1996-12-31

    Most 2D RF modeling codes use a parameterization of current drive efficiencies to calculate fast wave driven currents. This parameterization assumes a uniform diffusion coefficient and requires a priori knowledge of the wave polarizations. These difficulties may be avoided by a direct calculation of the quasilinear diffusion coefficient from the Kennel-Englemann form with the field polarizations calculated by a full wave code. This eliminates the need to use the approximation inherent in the parameterization. Current profiles are then calculated using the adjoint formulation. This approach has been implemented in the FISIC code. The accuracy of the parameterization of the current drive efficiency, {eta}, is judged by a comparison with a direct calculation: where {chi} is the adjoint function, {epsilon} is the kinetic energy, and {rvec {Gamma}} is the quasilinear flux. It is shown that for large aspect ratio devices ({epsilon} {r_arrow} 0), the parameterization is nearly identical to the direct calculation. As the aspect ratio approaches unity, visible differences between the two calculations appear.

  6. Trigger Pulse Generator Using Proposed Buffered Delay Model and Its Application

    Directory of Open Access Journals (Sweden)

    Amit Krishna Dwivedi

    2015-01-01

    Full Text Available This paper proposes a circuit capable of incorporating buffered delays in the order of picoseconds. To study our proposed circuit in the profound way, we have also explored our proposed circuit using emerging technologies such as FinFET and CNFET. Comparisons between these technologies have been made in terms of different parameters such as duration of incorporated delays (pulse width and its variability with supply voltages. Further, this paper also proposes a trigger pulse generator by utilizing proposed buffered delay circuit as its basic element. Parametric results obtained for the proposed trigger pulse generator match different application specific requirements. These applications are also mentioned in this paper. The proposed trigger pulse generator requires very low supply voltage (700 mV and also proves its effectiveness in terms of tunability of pulse width of the generated pulses. The modeling of the circuit has been done using Verilog and the simulation results are extensively verified using SPICE.

  7. Advances in modeling of lower hybrid current drive

    Science.gov (United States)

    Peysson, Y.; Decker, J.; Nilsson, E.; Artaud, J.-F.; Ekedahl, A.; Goniche, M.; Hillairet, J.; Ding, B.; Li, M.; Bonoli, P. T.; Shiraiwa, S.; Madi, M.

    2016-04-01

    First principle modeling of the lower hybrid (LH) current drive in tokamak plasmas is a longstanding activity, which is gradually gaining in accuracy thanks to quantitative comparisons with experimental observations. The ability to reproduce simulatenously the plasma current and the non-thermal bremsstrahlung radial profiles in the hard x-ray (HXR) photon energy range represents in this context a significant achievement. Though subject to limitations, ray tracing calculations are commonly used for describing wave propagation in conjunction with Fokker-Planck codes, as it can capture prominent features of the LH wave dynamics in a tokamak plasma-like toroidal refraction. This tool has been validated on several machines when the full absorption of the LH wave requires the transfer of a small fraction of power from the main lobes of the launched power spectrum to a tail at a higher parallel refractive index. Conversely, standard modeling based on toroidal refraction only becomes more challenging when the spectral gap is large, except if other physical mechanisms may dominate to bridge it, like parametric instabilities, as suggested for JET LH discharges (Cesario et al 2004 Phys. Rev. Lett. 92 175002), or fast fluctuations of the launched power spectrum or ‘tail’ LH model, as shown for Tore Supra (Decker et al 2014 Phys. Plasma 21 092504). The applicability of the heuristic ‘tail’ LH model is investigated for a broader range of plasma parameters as compared to the Tore Supra study and with different LH wave characteristics. Discrepancies and agreements between simulations and experiments depending upon the different models used are discussed. The existence of a ‘tail’ in the launched power spectrum significantly improves the agreement between modeling and experiments in plasma conditions for which the spectral gap is large in EAST and Alcator C-Mod tokamaks. For the Alcator C-Mod tokamak, the experimental evolution of the HXR profiles with density suggests

  8. Proposal of a regressive model for the hourly diffuse solar radiation under all sky conditions

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-Arias, J.A.; Alsamamra, H.; Tovar-Pescador, J.; Pozo-Vazquez, D. [Department of Physics, Building A3-066, University of Jaen, 23071 Jaen (Spain)

    2010-05-15

    In this work, we propose a new regressive model for the estimation of the hourly diffuse solar irradiation under all sky conditions. This new model is based on the sigmoid function and uses the clearness index and the relative optical mass as predictors. The model performance was compared against other five regressive models using radiation data corresponding to 21 stations in the USA and Europe. In a first part, the 21 stations were grouped into seven subregions (corresponding to seven different climatic regions) and all the models were locally-fitted and evaluated using these seven datasets. Results showed that the new proposed model provides slightly better estimates. Particularly, this new model provides a relative root mean square error in the range 25-35% and a relative mean bias error in the range -15% to 15%, depending on the region. In a second part, the potential global character of the new model was evaluated. To this end, the model was fitted using the whole dataset. Results showed that the global fitting model provides overall better estimates that the locally-fitted models, with relative root mean square error values ranging 20-35% and a relative mean bias error ranging -5% to -12%. Additionally, the new proposed model showed some advantages compared to other evaluated models. Particularly, the sigmoid behaviour of this model is able to provide physically reliable estimates for extreme values of the clearness index even though using less parameter than other tested models. (author)

  9. Model Predictive Control with Integral Action for Current Density Profile Tracking in NSTX-U

    Science.gov (United States)

    Ilhan, Z. O.; Wehner, W. P.; Schuster, E.; Boyer, M. D.

    2016-10-01

    Active control of the toroidal current density profile may play a critical role in non-inductively sustained long-pulse, high-beta scenarios in a spherical torus (ST) configuration, which is among the missions of the NSTX-U facility. In this work, a previously developed physics-based control-oriented model is embedded in a feedback control scheme based on a model predictive control (MPC) strategy to track a desired current density profile evolution specified indirectly by a desired rotational transform profile. An integrator is embedded into the standard MPC formulation to reject various modeling uncertainties and external disturbances. Neutral beam powers, electron density, and total plasma current are used as actuators. The proposed MPC strategy incorporates various state and actuator constraints directly into the control design process by solving a constrained optimization problem in real-time to determine the optimal actuator requests. The effectiveness of the proposed controller in regulating the current density profile in NSTX-U is demonstrated in closed-loop nonlinear simulations. Supported by the US DOE under DE-AC02-09CH11466.

  10. Comparison of Return Stroke Current Profiles for Transmission-Line-Type and Traveling-Current-Source-Type Models

    Directory of Open Access Journals (Sweden)

    J.O. Adepitan

    2012-05-01

    Full Text Available The study is aimed at determining the dependence of the current along a channel on the model used, assuming the same base current. We compared three transmission-line-type models, namely: Transmission Line (TL, Modified Transmission Line with Linear decay, Modified Transmission Line with Exponential decay and two traveling-current-source-type models: Bruce-Golde (BG and Traveling Current Source (TCS models. The current profiles along the channel at different heights predicted by these models are presented and discussed. Comparison is based on the assumption that all the models have the same base current. It was found that at low heights and within a time window frame of 15 :s, the currents of the transmission-line-type models predict a zero value at one time or the other with a maximum turning point following some 1:s after. A linear relationship is predicted between the current peak and the channel height. A discontinuity of current peak was observed at high heights. No zero value of current was recorded in case of TCS both at low and high channel heights.

  11. Proposed E-Health Service Model by using Smart Phone Apps for Uttarakhand

    National Research Council Canada - National Science Library

    Mukesh Joshi; Durgesh Pant

    2014-01-01

      For E-HEALTH initiatives in Uttarakhand the proposed E-HEALTH service model may allow better sharing of health information among multiple government departments, locally as well as at a distant location...

  12. Animal models of transcranial direct current stimulation: Methods and mechanisms.

    Science.gov (United States)

    Jackson, Mark P; Rahman, Asif; Lafon, Belen; Kronberg, Gregory; Ling, Doris; Parra, Lucas C; Bikson, Marom

    2016-11-01

    The objective of this review is to summarize the contribution of animal research using direct current stimulation (DCS) to our understanding of the physiological effects of transcranial direct current stimulation (tDCS). We comprehensively address experimental methodology in animal studies, broadly classified as: (1) transcranial stimulation; (2) direct cortical stimulation in vivo and (3) in vitro models. In each case advantages and disadvantages for translational research are discussed including dose translation and the overarching "quasi-uniform" assumption, which underpins translational relevance in all animal models of tDCS. Terminology such as anode, cathode, inward current, outward current, current density, electric field, and uniform are defined. Though we put key animal experiments spanning decades in perspective, our goal is not simply an exhaustive cataloging of relevant animal studies, but rather to put them in context of ongoing efforts to improve tDCS. Cellular targets, including excitatory neuronal somas, dendrites, axons, interneurons, glial cells, and endothelial cells are considered. We emphasize neurons are always depolarized and hyperpolarized such that effects of DCS on neuronal excitability can only be evaluated within subcellular regions of the neuron. Findings from animal studies on the effects of DCS on plasticity (LTP/LTD) and network oscillations are reviewed extensively. Any endogenous phenomena dependent on membrane potential changes are, in theory, susceptible to modulation by DCS. The relevance of morphological changes (galvanotropy) to tDCS is also considered, as we suggest microscopic migration of axon terminals or dendritic spines may be relevant during tDCS. A majority of clinical studies using tDCS employ a simplistic dose strategy where excitability is singularly increased or decreased under the anode and cathode, respectively. We discuss how this strategy, itself based on classic animal studies, cannot account for the

  13. A study of the effects of current and proposed restraint concepts on the child occupants of vehicles

    OpenAIRE

    2000-01-01

    This research evaluates the performance of automotive child restraint systems (CRS) that conform to international proposals for a universal restraint concept to be adopted by both restraint and vehicle manufacturers. The concept is known as Isofix (International Standards Organisation FIXing), and is intended to ensure optimum compatibility and coupling between vehicle and CRS. In order to quantify the benefits of the proposed Isofix concept it has been necessary to establish the performan...

  14. Operational advances in ring current modeling using RAM-SCB

    Energy Technology Data Exchange (ETDEWEB)

    Welling, Daniel T [Los Alamos National Laboratory; Jordanova, Vania K [Los Alamos National Laboratory; Zaharia, Sorin G [Los Alamos National Laboratory; Morley, Steven K [Los Alamos National Laboratory

    2010-12-03

    The Ring current Atmosphere interaction Model with Self-Consistently calculated 3D Magnetic field (RAM-SCB) combines a kinetic model of the ring current with a force-balanced model of the magnetospheric magnetic field to create an inner magnetospheric model that is magnetically self consistent. RAM-SCB produces a wealth of outputs that are valuable to space weather applications. For example, the anisotropic particle distribution of the KeV-energy population calculated by the code is key for predicting surface charging on spacecraft. Furthermore, radiation belt codes stand to benefit substantially from RAM-SCB calculated magnetic field values and plasma wave growth rates - both important for determining the evolution of relativistic electron populations. RAM-SCB is undergoing development to bring these benefits to the space weather community. Data-model validation efforts are underway to assess the performance of the system. 'Virtual Satellite' capability has been added to yield satellite-specific particle distribution and magnetic field output. The code's outer boundary is being expanded to 10 Earth Radii to encompass previously neglected geosynchronous orbits and allow the code to be driven completely by either empirical or first-principles based inputs. These advances are culminating towards a new, real-time version of the code, rtRAM-SCB, that can monitor the inner magnetosphere conditions on both a global and spacecraft-specific level. This paper summarizes these new features as well as the benefits they provide the space weather community.

  15. A business model improvement proposal for Finnish enterprises doing business in China : case study: Hankintatukku Oy

    OpenAIRE

    Wang, Mengzhen

    2015-01-01

    This study aims to propose a more adaptable business model for Finnish Hankintatukku Oy to help it be more successful in China. To achieve the objective, inductive research approach with qualitative and quantitative research methods are used in this thesis. With inductive research approach, data is collected to analyze the main elements inside a business model and marketing development trend in China. As a result, the final proposal comes out based on the marketing development trend in China ...

  16. Empirical Evaluation of the Proposed eXSCRUM Model-Results of a Case Study

    Directory of Open Access Journals (Sweden)

    M Rizwan Jameel Qureshi

    2011-05-01

    Full Text Available Agile models promote fast development. XP and Scrum are the most widely used agile models. This paper investigates the phases of XP and Scrum models in order to identify their potentials and drawbacks. XP model has certain drawbacks, such as not suitable for maintenance projects and poor performance for medium and large-scale development projects. Scrum model has certain limitations, such as lacked in engineering practices. Since, both XP and Scrum models contain good features and strengths but still there are improvement possibilities in these models. Majority of the software development companies are reluctant to switch from traditional methodologies to agile methodologies for development of industrial projects. A fine integration, of software management of the Scrum model and engineering practices of XP model, is very much required to accumulate the strengths and remove the limitations of both models. This is achieved by proposing an eXScrum model. The proposed model is validated by conducting a controlled case study. The results of case study show that the proposed integrated eXScrum model enriches the potentials of both XP and Scrum models and eliminates their drawbacks.

  17. Current state of genome-scale modeling in filamentous fungi.

    Science.gov (United States)

    Brandl, Julian; Andersen, Mikael R

    2015-06-01

    The group of filamentous fungi contains important species used in industrial biotechnology for acid, antibiotics and enzyme production. Their unique lifestyle turns these organisms into a valuable genetic reservoir of new natural products and biomass degrading enzymes that has not been used to full capacity. One of the major bottlenecks in the development of new strains into viable industrial hosts is the alteration of the metabolism towards optimal production. Genome-scale models promise a reduction in the time needed for metabolic engineering by predicting the most potent targets in silico before testing them in vivo. The increasing availability of high quality models and molecular biological tools for manipulating filamentous fungi renders the model-guided engineering of these fungal factories possible with comprehensive metabolic networks. A typical fungal model contains on average 1138 unique metabolic reactions and 1050 ORFs, making them a vast knowledge-base of fungal metabolism. In the present review we focus on the current state as well as potential future applications of genome-scale models in filamentous fungi.

  18. A Proposed Model for Examining the Organizational Readiness Assessment of Information Systems Development: A case study of a public university

    Directory of Open Access Journals (Sweden)

    Mohammad Lagzian

    2014-03-01

    Full Text Available The findings of several prior studies indicate high failure rate of Information systems implementation projects in different organizations. These studies also point to the fact that many of these failures are as a result of organizational issues as well as not paying attention to current situation of the organization in early stages of Information system development, rather than technical issues. In other words, successful implementation of an information system is directly depending on current situation of the organization. Considering high needed investment for implementing an information system project, it seems to be necessary to assess its current organizational readiness level. In this study, on the basis of a comprehensive reviewing various relevant models of readiness assessment for information systems development has been attempted to present a model about the existing realities and internal circumstances in public sector organizations and institutions emphasizing on universities and higher education institutions. Based on proposed model, to assess organizational readiness, six major dimensions (Strategic, Structural, Resources, Cultural, Managerial, and Legal were identified from the literature which was divided into 47 sub-dimensions and 142 indicators. The identified indicators can be used to assess organizational readiness in order to facilitate a purposeful and appropriate information system development and consequently to prevent the waste of organizational resources. The proposed model also was used in a public university as a case with the aim of determination of organizational readiness level, and finally several action plans were suggested based on the obtained research results.

  19. Automating Construction of Machine Learning Models With Clinical Big Data: Proposal Rationale and Methods

    Science.gov (United States)

    Stone, Bryan L; Johnson, Michael D; Tarczy-Hornoch, Peter; Wilcox, Adam B; Mooney, Sean D; Sheng, Xiaoming; Haug, Peter J; Nkoy, Flory L

    2017-01-01

    Background To improve health outcomes and cut health care costs, we often need to conduct prediction/classification using large clinical datasets (aka, clinical big data), for example, to identify high-risk patients for preventive interventions. Machine learning has been proposed as a key technology for doing this. Machine learning has won most data science competitions and could support many clinical activities, yet only 15% of hospitals use it for even limited purposes. Despite familiarity with data, health care researchers often lack machine learning expertise to directly use clinical big data, creating a hurdle in realizing value from their data. Health care researchers can work with data scientists with deep machine learning knowledge, but it takes time and effort for both parties to communicate effectively. Facing a shortage in the United States of data scientists and hiring competition from companies with deep pockets, health care systems have difficulty recruiting data scientists. Building and generalizing a machine learning model often requires hundreds to thousands of manual iterations by data scientists to select the following: (1) hyper-parameter values and complex algorithms that greatly affect model accuracy and (2) operators and periods for temporally aggregating clinical attributes (eg, whether a patient’s weight kept rising in the past year). This process becomes infeasible with limited budgets. Objective This study’s goal is to enable health care researchers to directly use clinical big data, make machine learning feasible with limited budgets and data scientist resources, and realize value from data. Methods This study will allow us to achieve the following: (1) finish developing the new software, Automated Machine Learning (Auto-ML), to automate model selection for machine learning with clinical big data and validate Auto-ML on seven benchmark modeling problems of clinical importance; (2) apply Auto-ML and novel methodology to two new

  20. Automating Construction of Machine Learning Models With Clinical Big Data: Proposal Rationale and Methods.

    Science.gov (United States)

    Luo, Gang; Stone, Bryan L; Johnson, Michael D; Tarczy-Hornoch, Peter; Wilcox, Adam B; Mooney, Sean D; Sheng, Xiaoming; Haug, Peter J; Nkoy, Flory L

    2017-08-29

    To improve health outcomes and cut health care costs, we often need to conduct prediction/classification using large clinical datasets (aka, clinical big data), for example, to identify high-risk patients for preventive interventions. Machine learning has been proposed as a key technology for doing this. Machine learning has won most data science competitions and could support many clinical activities, yet only 15% of hospitals use it for even limited purposes. Despite familiarity with data, health care researchers often lack machine learning expertise to directly use clinical big data, creating a hurdle in realizing value from their data. Health care researchers can work with data scientists with deep machine learning knowledge, but it takes time and effort for both parties to communicate effectively. Facing a shortage in the United States of data scientists and hiring competition from companies with deep pockets, health care systems have difficulty recruiting data scientists. Building and generalizing a machine learning model often requires hundreds to thousands of manual iterations by data scientists to select the following: (1) hyper-parameter values and complex algorithms that greatly affect model accuracy and (2) operators and periods for temporally aggregating clinical attributes (eg, whether a patient's weight kept rising in the past year). This process becomes infeasible with limited budgets. This study's goal is to enable health care researchers to directly use clinical big data, make machine learning feasible with limited budgets and data scientist resources, and realize value from data. This study will allow us to achieve the following: (1) finish developing the new software, Automated Machine Learning (Auto-ML), to automate model selection for machine learning with clinical big data and validate Auto-ML on seven benchmark modeling problems of clinical importance; (2) apply Auto-ML and novel methodology to two new modeling problems crucial for care

  1. Deep Submarine Tailings Disposal (DSTP) the Proposed Use of Submarine Canyons and Artificial Turbidity Currents for the Disposal of Mine Waste: Current Practice, Future Plans, and Cumulative Impacts.

    Science.gov (United States)

    Young, R.; Moran, R.

    2015-12-01

    The wastes from mining operations ( tailings) have been disposed of in the fluvial environment (riverine disposal) and in nearshore marine environments for much of the last century. The scale of modern mining operations has led to increasing use of steep slopes and submarine canyons for deposition of these wastes at depths of 2000m - 4000m. Current mine disposal operations in Indonesia and Papua New Guinea which use Deep Sea Tailings Placement (DSTP) release volumes between 5000 tpd and 160,000 tpd. Planning is underway by the"Consortium," an industry and government group in Chile which would deposit mine waste of 1M tpd into the Humbolt Current Large Marine Ecosystem (HCLME) which provides nearly 20% of the fish biomass harvested on a sustainable basis worldwide. Underwater pipelines discharge tailings as a slurry to create a continuous artificial turbidity current with particle size distribtions (PSD's) ranging from sand to clay sized fractions. Potential problems arise from benthic smothering, angular particulate uptake by benthic organisms, and from the bioaccumulation of a complex of heavy metals by both benthic and pelagic species. While much is known about the binding of copper and other toxic heavy metals in a reducing environment, little has been done to consider the implications of ocean dumping where 1% of tailings discharged may consist of unrecovered heavy metals. Synergistic cumulative impacts to just the HCLME from the dumping of the more than 3M tpy of reactive metals in these tailings sediments remains unknown and poses substantial risks. DSTP assumes a stable deep sea depositional environment but upwelling currents and plume shear may make this hard to accomplish.

  2. Considering digits in a current model of numerical development

    Science.gov (United States)

    Roesch, Stephanie; Moeller, Korbinian

    2015-01-01

    Numerical cognition has long been considered the perfect example of abstract information processing. Nevertheless, there is accumulating evidence in recent years suggesting that the representation of number magnitude may not be entirely abstract but may present a specific case of embodied cognition rooted in the sensory and bodily experiences of early finger counting and calculating. However, so far none of the existing models of numerical development considers the influence of finger-based representations. Therefore, we make first suggestions on (i) how finger-based representations may be integrated into a current model of numerical development; and (ii) how they might corroborate the acquisition of basic numerical competencies at different development levels. PMID:25628559

  3. Eddy Current Modeling and Measuring in Fast-Pulsed Resistive Magnets

    CERN Document Server

    Arpaia, P; Gollucio, G; Montenero, G

    2010-01-01

    A method for modeling and measuring electromagnetic transients due to eddy currents in fast-pulsed resistive magnets is proposed. In particular, an equivalent-circuit model and a method for time-domain measurements of eddy currents are presented. The measurements are needed for an accurate control of the magnetic field quality to ensure adequate stability and performance of the particle beam in particle accelerators in dynamic conditions (field ramps up to about 700 T/s). In the second part, the results of experiments for model definition, identification, and validation are discussed. The tests were carried out on a quadrupole of Linac4, a new linear particle accelerator under construction at CERN (European Organization for Nuclear Research).

  4. Modeling and analysis of sub-surface leakage current in nano-MOSFET under cutoff regime

    Science.gov (United States)

    Swami, Yashu; Rai, Sanjeev

    2017-02-01

    The high leakage current in nano-meter regimes is becoming a significant portion of power dissipation in nano-MOSFET circuits as threshold voltage, channel length, and gate oxide thickness are scaled down to nano-meter range. Precise leakage current valuation and meticulous modeling of the same at nano-meter technology scale is an increasingly a critical work in designing the low power nano-MOSFET circuits. We present a specific compact model for sub-threshold regime leakage current in bulk driven nano-MOSFETs. The proposed logical model is instigated and executed into the latest updated PTM bulk nano-MOSFET model and is found to be in decent accord with technology-CAD simulation data. This paper also reviews various transistor intrinsic leakage mechanisms for nano-MOSFET exclusively in weak inversion, like drain-induced barricade lowering (DIBL), gate-induced drain leakage (GIDL), gate oxide tunneling (GOT) leakage etc. The root cause of the sub-surface leakage current is mainly due to the nano-scale short channel length causing source-drain coupling even in sub-threshold domain. Consequences leading to carriers triumphing the barricade between the source and drain. The enhanced model effectively considers the following parameter dependence in the account for better-quality value-added results like drain-to-source bias (VDS), gate-to-source bias (VGS), channel length (LG), source/drain junction depth (Xj), bulk doping concentration (NBULK), and operating temperature (Top).

  5. A Mathematical Model of Neonatal Rat Atrial Monolayers with Constitutively Active Acetylcholine-Mediated K+ Current.

    Science.gov (United States)

    Majumder, Rupamanjari; Jangsangthong, Wanchana; Feola, Iolanda; Ypey, Dirk L; Pijnappels, Daniël A; Panfilov, Alexander V

    2016-06-01

    Atrial fibrillation (AF) is the most frequent form of arrhythmia occurring in the industrialized world. Because of its complex nature, each identified form of AF requires specialized treatment. Thus, an in-depth understanding of the bases of these arrhythmias is essential for therapeutic development. A variety of experimental studies aimed at understanding the mechanisms of AF are performed using primary cultures of neonatal rat atrial cardiomyocytes (NRAMs). Previously, we have shown that the distinct advantage of NRAM cultures is that they allow standardized, systematic, robust re-entry induction in the presence of a constitutively-active acetylcholine-mediated K+ current (IKACh-c). Experimental studies dedicated to mechanistic explorations of AF, using these cultures, often use computer models for detailed electrophysiological investigations. However, currently, no mathematical model for NRAMs is available. Therefore, in the present study we propose the first model for the action potential (AP) of a NRAM with constitutively-active acetylcholine-mediated K+ current (IKACh-c). The descriptions of the ionic currents were based on patch-clamp data obtained from neonatal rats. Our monolayer model closely mimics the action potential duration (APD) restitution and conduction velocity (CV) restitution curves presented in our previous in vitro studies. In addition, the model reproduces the experimentally observed dynamics of spiral wave rotation, in the absence and in the presence of drug interventions, and in the presence of localized myofibroblast heterogeneities.

  6. Hyperpolarization-Activated Current Induces Period-Doubling Cascades and Chaos in a Cold Thermoreceptor Model

    Science.gov (United States)

    Xu, Kesheng; Maidana, Jean P.; Caviedes, Mauricio; Quero, Daniel; Aguirre, Pablo; Orio, Patricio

    2017-01-01

    In this article, we describe and analyze the chaotic behavior of a conductance-based neuronal bursting model. This is a model with a reduced number of variables, yet it retains biophysical plausibility. Inspired by the activity of cold thermoreceptors, the model contains a persistent Sodium current, a Calcium-activated Potassium current and a hyperpolarization-activated current (Ih) that drive a slow subthreshold oscillation. Driven by this oscillation, a fast subsystem (fast Sodium and Potassium currents) fires action potentials in a periodic fashion. Depending on the parameters, this model can generate a variety of firing patterns that includes bursting, regular tonic and polymodal firing. Here we show that the transitions between different firing patterns are often accompanied by a range of chaotic firing, as suggested by an irregular, non-periodic firing pattern. To confirm this, we measure the maximum Lyapunov exponent of the voltage trajectories, and the Lyapunov exponent and Lempel-Ziv's complexity of the ISI time series. The four-variable slow system (without spiking) also generates chaotic behavior, and bifurcation analysis shows that this is often originated by period doubling cascades. Either with or without spikes, chaos is no longer generated when the Ih is removed from the system. As the model is biologically plausible with biophysically meaningful parameters, we propose it as a useful tool to understand chaotic dynamics in neurons. PMID:28344550

  7. Admittance Modeling of Voltage and Current Controlled Inverter for Harmonic Instability Studies

    DEFF Research Database (Denmark)

    Hoseinzadeh, Bakhtyar; Bak, Claus Leth

    2016-01-01

    This paper proposes an impedance/admittance based model for voltage and current controlled inverters with passive elements suitable for harmonic instability study of grid connected inverters in frequency domain. This linearized model of inverters, significantly simplifies investigation of resonance...... instability and control loop interaction of wind turbines with each other and/or with the grid, while they are installed in wind farms. The derived impedance ratio at point of common connection demonstrates how the inverters participate in harmonic stability of the grid....

  8. High resolution modelling of the North Icelandic Irminger Current (NIIC

    Directory of Open Access Journals (Sweden)

    K. Logemann

    2006-01-01

    Full Text Available The northward inflow of Atlantic Water through Denmark Strait – the North Icelandic Irminger Current (NIIC – is simulated with a numerical model of the North Atlantic and Arctic Ocean. The model uses the technique of adaptive grid refinement which allows a high spatial resolution (1 km horizontal, 10 m vertical around Iceland. The model is used to assess time and space variability of volume and heat fluxes for the years 1997–2003. Passive tracers are applied to study origin and composition of NIIC water masses. The NIIC originates from two sources: the Irminger Current, flowing as part of the sub-polar gyre in 100–500 m depth along the Reykjanes Ridge and the shallow Icelandic coastal current, flowing north-westward on the south-west Icelandic shelf. The ratio of volume flux between the deep and shallow branch is around 2:1. The NIIC continues as a warm and saline branch northward through Denmark Strait where it entrains large amounts of polar water due to the collision with the southward flowing East Greenland Current. After passing Denmark Strait, the NIIC follows the coast line eastward being an important heat source for north Icelandic waters. At least 60% of the temporal temperature variability of north Icelandic waters is caused by the NIIC. The NIIC volume and heat transport is highly variable and depends strongly on the wind field north-east of Denmark Strait. Daily means can change from 1 Sv eastward to 2 Sv westward within a few days. Highest monthly mean transport rates occur in summer when winds from north are weak, whereas the volume flux is reduced by around 50% in winter. Summer heat flux rates can be even three times higher than in winter. The simulation also shows variability on the interannual scale. In particular weak winds from north during winter 2002/2003 combined with mild weather conditions south of Iceland led to anomalous high NIIC volume (+40% and heat flux (+60% rates. In this period, simulated north Icelandic

  9. Renewal and Completion Problems in Geographical Databases in Turkey and a Proposal Model

    Directory of Open Access Journals (Sweden)

    Ali Erdi

    2007-05-01

    Full Text Available Defence, security, public works, and many other branches of government require small-scale, current geographical databases. With this aim, small-scale geographical databases in Turkey were produced in the past and are still in use today. There are, however, problems in using the available geographical databases. These problems in forming, sharing, updating, and meeting requirements necessitate the reconfiguration of the present system. Classical approaches are preferred when updating the present geographical databases. Many errors and difficulties in recording new objects have occurred in the field, in scanning and collecting data from related institutions, and in recording and controlling nonstandard completion data. Thus it is difficult to achieve the desired high quality data with the present method. In this study, we introduce and discuss updating and completing small-scale maps of geographical bases. The Geographical Information System formation studies in Turkey are summarized, and a model is proposed for the formation, updating, and completion of systems of small-scale maps of significant databases.

  10. Proposals and developments in radiation dose selection occurring within ISO/TC/198 intended to address current problems

    Energy Technology Data Exchange (ETDEWEB)

    Whitby, J.L. [Department of Microbiology, University of Western Ontario, London, ON (Canada)

    1998-12-31

    ISO/TC/198 has now been in operation for 8 years during that time one Standard and a number of Technical reports (TRs) have been published. Except for ISO/TR 13409 these have all been more appropriate to devices manufactured in large numbers. Most of the documents approved so far have already been used in earlier AAMI standards. One item from earlier standards was a method allowing sterilization dose to be validated on the basis of determining the radiation resistance of the bioburden found on devices. This method has value for devices manufactured in small numbers which fail to pass ISO 11137 Method 1. A study was undertaken by a number of Japanese manufactures to assess the radiation resistance of the bioburden, with the intention of calculating a radiation sterilization dose from the information so obtained. The findings of this investigation will be reviewed and proposals for developing a method based on them will be discussed. In recent months a new proposal for the validation of a 25 kGy dose has been promulgated. This proposal, and some of the proposals i will be discussing, make provision for a much higher verification dose than can be used in ISO 11137, Method 1 or its modification found in ISO 13409. (author)

  11. LUGH, the Proposed Mercury Express Mission, as an Ideal, Current, Low-Cost, Low-Risk Option for Mercury Exploration

    Science.gov (United States)

    Clark, P. E.; Lawlor, S. McKenna; Curtis, S.; Marr, G.; Giles, B.

    2000-01-01

    We propose an ESA Flexi Mission, LUGH, Mercury Express Mission, an extremely fast, low cost, low risk, high return, three-platform, multiple flyby mission which would provide data which are unique and complimentary to recently selected long lead time Mercury missions.

  12. LUGH, the Proposed Mercury Express Mission, as an Ideal, Current, Low-Cost, Low-Risk Option for Mercury Exploration

    Science.gov (United States)

    Clark, P. E.; Lawlor, S. McKenna; Curtis, S.; Marr, G.; Giles, B.

    2000-01-01

    We propose an ESA Flexi Mission, LUGH, Mercury Express Mission, an extremely fast, low cost, low risk, high return, three-platform, multiple flyby mission which would provide data which are unique and complimentary to recently selected long lead time Mercury missions.

  13. Proposed Model of Information Behaviour in Crisis: The Case of Hurricane Sandy

    Science.gov (United States)

    Lopatovska, Irene; Smiley, Bobby

    2013-01-01

    Introduction: The paper proposes a model of information behaviour in crisis. No previous model has attempted to integrate information resources, information behaviour and needs of the storm-affected communities within the temporal stages of a natural disaster. Method: The study was designed as autoethnography. The data were collected through a…

  14. Sigma models for bundles on Calabi-Yau: a proposal for matrix string compactifications

    NARCIS (Netherlands)

    Hofman, C.; Park, J.-S.

    2001-01-01

    W e describe a class of supersymmetric gauged linear sigma-model, whose target space is the infinite dimensional space of bundles on a Calabi-Y au 3- or 2-fold. This target space can be considered the configuration space of D-branes wrapped around the Calabi-Yau. We propose that this model can be us

  15. Proposing an Educational Scaling-and-Diffusion Model for Inquiry-Based Learning Designs

    Science.gov (United States)

    Hung, David; Lee, Shu-Shing

    2015-01-01

    Education cannot adopt the linear model of scaling used by the medical sciences. "Gold standards" cannot be replicated without considering process-in-learning, diversity, and student-variedness in classrooms. This article proposes a nuanced model of educational scaling-and-diffusion, describing the scaling (top-down supports) and…

  16. Proposing an Educational Scaling-and-Diffusion Model for Inquiry-Based Learning Designs

    Science.gov (United States)

    Hung, David; Lee, Shu-Shing

    2015-01-01

    Education cannot adopt the linear model of scaling used by the medical sciences. "Gold standards" cannot be replicated without considering process-in-learning, diversity, and student-variedness in classrooms. This article proposes a nuanced model of educational scaling-and-diffusion, describing the scaling (top-down supports) and…

  17. Modelling ac ripple currents in HTS coated conductors

    Science.gov (United States)

    Xu, Zhihan; Grilli, Francesco

    2015-10-01

    Dc transmission using high temperature superconducting (HTS) coated conductors (CCs) offers a promising solution to the globally growing demand for effective, reliable and economic transmission of green energy up to the gigawatt level over very long distances. The credible estimation of the losses and thereby the heat dissipation involved, where ac ripples (introduced in rectification/ac-dc conversion) are viewed as a potential source of notable contribution, is highly essential for the rational design of practical HTS dc transmission cables and corresponding cryogenic systems to fulfil this demand. Here we report a targeted modelling study into the ac losses in a HTS CC subject to dc and ac ripple currents simultaneously, by solving Maxwell’s equations using the finite element method (FEM) in the commercial software package COMSOL. It is observed that the instantaneous loss exhibits only one peak per cycle in the HTS CC subject to sinusoidal ripples, given that the amplitude of the ac ripples is smaller than approximately 20% of that of the dc current. This is a distinct contrast to the usual observation of two peaks per cycle in a HTS CC subject to ac currents only. The unique mechanism is also revealed, which is directly associated with the finding that, around any local minima of the applied ac ripples, the critical state of -J c is never reached at the edges of the HTS CC, as it should be according to the Bean model. When running further into the longer term, it is discovered that the ac ripple loss of the HTS CC in full-wave rectification decays monotonically, at a speed which is found to be insensitive to the frequency of the applied ripples within our targeted situations, to a relatively low level of approximately 1.38 × 10-4 W m-1 in around 1.7 s. Comparison between this level and other typical loss contributions in a HTS dc cable implies that ac ripple currents in HTS CCs should only be considered as a minor source of dissipation in superconducting dc

  18. Simplified Modeling, Analysis and Simulation of Permanent Magnet Brushless Direct Current Motors for Sensorless Operation

    Directory of Open Access Journals (Sweden)

    E. Kaliappan

    2012-01-01

    Full Text Available Problem statement: In this study, a simplified modeling and experimental analysis of Permanent Magnet Brushless DC (PMBLDC motors for Sensorless operation using MATLAB/SIMULINK. This model provides a mechanism for monitoring and controlling the voltage, current, speed and torque response. Approach: BLDC motor is modeled as sub-blocks. The inverter and switching function are implemented as S-function builder block. The Sensorless scheme employs direct back emf based zero crossing detection technique. Results: The proposed model with Sensorless control technique with back emf zero crossing detection is tested in the BLDC Motor and the performance was evaluated. The simulated and experimental results show that the proposed modeling works quite well during starting and running conditions. Conclusion/Recommendation: The developed model consists of several independent sub-blocks, that can be used in the modeling of Permanent Magnet Sinusoidal Motor and induction motor. Hence the developed simulation model is a design tool to study the dynamic behavior of Sensorless Controlled Brushless DC Motor.

  19. Shigella vaccine development: prospective animal models and current status.

    Science.gov (United States)

    Kim, Yeon-Jeong; Yeo, Sang-Gu; Park, Jae-Hak; Ko, Hyun-Jeong

    2013-01-01

    Shigella was first discovered in 1897 and is a major causative agent of dysenteric diarrhea. The number of affected patients has decreased globally because of improved sanitary conditions; however, Shigella still causes serious problems in many subjects, including young children and the elderly, especially in developing countries. Although antibiotics may be effective, a vaccine would be the most powerful solution to combat shigellosis because of the emergence of drug-resistant strains. However, the development of a vaccine is hampered by several problems. First, there is no suitable animal model that can replace human-based studies for the investigation of the in vivo mechanisms of Shigella vaccines. Mouse, guinea pig, rat, rabbit, and nonhuman primates could be used as models for shigellosis, but they do not represent human shigellosis and each has its own weaknesses. However, a recent murine model based on peritoneal infection with virulent S. flexneri 2a is promising. Moreover, although the inflammatory responses and mechanisms such as pathogenassociated molecular patterns and danger-associated molecular patterns have been studied, the pathology and immunology of Shigella are still not clearly defined. Despite these obstacles, many vaccine candidates have been developed, including live attenuated, killed whole cells, conjugated, and subunit vaccines. The development of Shigella vaccines also demands considerations of the cost, routes of administration, ease of storage (stability), cross-reactivity, safety, and immunogenicity. The main aim of this review is to provide a detailed introduction to the many promising vaccine candidates and animal models currently available, including the newly developed mouse model.

  20. Lessons from the Current Japanese Triple Helix Model

    Directory of Open Access Journals (Sweden)

    Mitsuaki Hosono

    2012-12-01

    Full Text Available Since mid-1990s, the Japanese government has encouraged university-industry collaboration to foster innovations for economic growth. Learning from the American licensing model of technology transfer, Japanese Bay-Dole Act and TLO (Technology Licensing Organization Act were enacted in late 1990s. In addition, the corporatization of Japanese National Universities (JNUs in 2004 spurred their technology-transfer activities to obtain external funds. As a result, more than 50 TLOs has been established since FY1998, and also the number of patent application and licensed patents were increased at JUNs rapidly after FY2004. However, the licensing income has been stayed poor and some of TLOs were abolished. There are few evidences that the introduction of licensing model of technology transfer into Japan could contribute to innovation properly. Therefore, this study will try to clarify if licensing model of technology transfer work in Japan by analyzing the Japanese National University (JNU patent. There are 20,485 applied patent, which invented by JNU’s researcher(s from FY2004 to 2007. 38% of them were applied by solely by JNUs and 52% were by JNU and Private Firms etc. In the Japanese Patent Act, jointly applied patents are not licensed to the third party without the consent of co-applicant(s. Hence, more than half of the patent invented by JNU researchers is not basically used for patent licensing. Consequently, JNUs and TLOs face difficulties in patent licensing under the current Patent Act.

  1. Current Capabilities of the Fuel Performance Modeling Code PARFUME

    Energy Technology Data Exchange (ETDEWEB)

    G. K. Miller; D. A. Petti; J. T. Maki; D. L. Knudson

    2004-09-01

    The success of gas reactors depends upon the safety and quality of the coated particle fuel. A fuel performance modeling code (called PARFUME), which simulates the mechanical and physico-chemical behavior of fuel particles during irradiation, is under development at the Idaho National Engineering and Environmental Laboratory. Among current capabilities in the code are: 1) various options for calculating CO production and fission product gas release, 2) a thermal model that calculates a time-dependent temperature profile through a pebble bed sphere or a prismatic block core, as well as through the layers of each analyzed particle, 3) simulation of multi-dimensional particle behavior associated with cracking in the IPyC layer, partial debonding of the IPyC from the SiC, particle asphericity, kernel migration, and thinning of the SiC caused by interaction of fission products with the SiC, 4) two independent methods for determining particle failure probabilities, 5) a model for calculating release-to-birth (R/B) ratios of gaseous fission products, that accounts for particle failures and uranium contamination in the fuel matrix, and 6) the evaluation of an accident condition, where a particle experiences a sudden change in temperature following a period of normal irradiation. This paper presents an overview of the code.

  2. A System Thinking Model Proposal for Enterprise Application Integration (EAI Evaluation Completeness

    Directory of Open Access Journals (Sweden)

    Irene Nakiyimba

    2014-01-01

    Full Text Available Research has identified a number of approaches for evaluating Enterprise Application Integration (EAI. The majority of these approaches focus primarily on the technical functional and non-functional capabil¬ities of an EAI solution. Although, where the technical dimensions have received considerable attention from researchers, other dimensions needed for EAI evaluation, such as stakeholder feedback, have not re¬ceived explicit consideration. As a result, attaining a consummate EAI solution is still a major challenge for many enterprises. The current EAI evaluation models simply provide piecemeal insights towards the evaluation criteria variables from limited stakeholder perceptions and do not help to understand EAI evaluation as a dynamic, feedback, time based and non-linear problem. Different stakeholders view the outcome of an EAI project from different perspectives and therefore will more likely than not arrive at different conclusions. To achieve a consensus among stakeholder perceptions, we represent EAI evaluation as a feedback analysis problem from multi-stakeholder perceptions for proper alignment with business goals, vision and mission. This paper proposes the application of System Dynamics (SD model towards guiding policy analysis for evaluating criteria factors from multi-stakeholders perceptions for EAI adoption; this will provide for holistic evaluation where emphasis is the importance of evaluation as whole (not piece meal perceptions and the interdependence of evaluation criteria factors from the diverse stakeholder perceptions is analyzed. In this paper we present a case-study performed at a large portion of the East African banking system. A total of 800 responses to questionnaires are analyzed to formulate a systems thinking model, which in turn allows us to analyze feedback loops between different stakeholders with distinct evaluation criteria. Findings result in a structured and holistic systems thinking model which

  3. Proposal of leak path passivation for InGaN solar cells to reduce the leakage current

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ke, E-mail: ke.wang@chiba-u.jp; Imai, Daichi; Kusakabe, Kazuhide [Center for SMART Green Innovation Research, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan); Yoshikawa, Akihiko, E-mail: yoshi@faculty.chiba-u.jp [Center for SMART Green Innovation Research, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan); Department of Information and Communication Engineering, Graduate School of Engineering, Kogakuin University, Nakano-cho, Hachioji, Tokyo 2665-1 (Japan)

    2016-01-25

    We propose some general ways to passivate the leak paths in InGaN solar cells and report some experimental evidences of its effectiveness. By adopting an AlOx passivation process, the photovoltaic performances of GaN pn-junctions and InGaN solar cells, grown by molecular beam epitaxy, have been significantly improved. The open circuit voltage under 1 sun illumination increases from 1.46 to 2.26 V for a GaN pn junction, and from 0.95 to 1.27 V for an InGaN solar cell, demonstrating evidence of leak path passivation (LPP) by AlOx. The proposed LPP is expected to be a realistic way to exploit the potential of thick and relaxed but defective InGaN for solar cell applications.

  4. Ecosystem Modeling in the South Central US: A Synthesis of Current Models toward the Development of Coupled Models

    Science.gov (United States)

    Kc, M.

    2015-12-01

    Ecosystem services and products are the foundation of sustainability for regional and global economy since we are directly or indirectly dependent on the ecosystem services like food, livestock, water, air, wildlife etc. It has been increasingly recognized that for sustainability concerns, the conservation problems need to be addressed in the context of entire ecosystems. This approach known as the ecosystem approach is fundamental to managing earth's finite resources since it addresses the interactions that link biotic systems, of which human, flora and fauna are integral parts, with the physical systems on which they depend. This approach is even more vital in the 21st century with formidable increasing human population and rapid changes in global environment. This study is being conducted to find the state of the science of ecosystem models in the South-Central region of US. The propose of the project is to conduct a systematic review and synthesize relevant information on the current state of the science of ecosystem modeling in the South-Central region of US toward coupling these models with climate, agronomic, hydrologic, economic or management models to better represent ecosystem dynamics as affected by climate change and human activities; and hence gain more reliable predictions of future ecosystem functions and service in the region. Better understandings of such processes will increase our ability to predict the ecosystem responses and feedbacks to environmental and human induced change in the region so that decision makers can make an informed management decisions of the ecosystem.

  5. Cocaine use disorder prevalence: From current DSM-IV to proposed DSM-5 diagnostic criteria with both a two and three severity level classification system.

    Science.gov (United States)

    Proctor, Steven L; Kopak, Albert M; Hoffmann, Norman G

    2014-06-01

    This article presents a secondary analysis from a study investigating the compatibility of the current DSM-IV and previously proposed DSM-5 cocaine use disorder (CUD) criteria (S. L. Proctor, A. M. Kopak, & N. G. Hoffmann, 2012, Compatibility of current DSM-IV and proposed DSM-5 diagnostic criteria for cocaine use disorders. Addictive Behaviors, 37, 722-728). The current analyses examined the compatibility of the current DSM-IV and two sets of proposed DSM-5 diagnostic criteria for CUDs among adult male inmates (N = 6,871) recently admitted to the Minnesota Department of Corrections state prison system from 2000-2003. Initially proposed DSM-5 criteria (DSM-5.0) featured only two diagnostic designations (i.e., moderate and severe). A subsequent revision (DSM-5.1) included the addition of a mild designation and required a greater number of positive findings for the severe designation. A computer-prompted structured diagnostic interview was administered to all inmates as part of routine clinical assessments. The past 12-month prevalence of DSM-IV CUDs was 12.70% (Abuse, 3.78%, Dependence, 8.92%), while 10.98% met past 12-month DSM-5.1 criteria for a CUD (Mild [MiCUD], 1.72%; Moderate [MCUD], 1.12%; and Severe [SCUD], 8.14%). The vast majority of those with no diagnosis (99.6%) continued to have no diagnosis, and most of those with a dependence diagnosis (91.2%) met SCUD criteria of the proposed DSM-5.1. Most of the variation in DSM-5.1 diagnostic classifications was accounted for by those with a current abuse diagnosis. DSM-5.0 MCUD cases were most affected when DSM-5.1 criteria were applied. The proposed diagnostic changes might translate to reduced access to treatment for those individuals evincing symptoms consistent with DSM-IV cocaine abuse.

  6. Specification of laboratory animal use in scientific articles: current low detail in the journals' instructions for authors and some proposals.

    Science.gov (United States)

    Alfaro, V

    2005-09-01

    The scientific article communicates results of research to other investigators; therefore, it must contain a complete description of the experiment to help other researchers when designing their future investigations. However, poorly detailed data on laboratory animal use is given in published articles. Despite the well-known and important contribution of the International Committee of Medical Journal Editors (ICMJE) to standardize scientific writing and submission of manuscripts to biomedical journals, no specific instructions on the reporting of animal use are given in the ICMJE Uniform Requirements and, therefore, most journals do not detail this to the authors. Individual efforts from groups like the Working Committee for the Biological Characterizations of Laboratory Animals, the Boyd Group, or the Committee on Publication Ethics are commendable. These contributions should be incorporated into the ICMJE Uniform Requirements and, later, into the Instructions for Authors of peer-reviewed journals. This would be the only efficient way to instruct authors on how to report laboratory animal use in their submitted manuscripts. The present article relates some proposals for helping authors when reporting animal use in scientific articles. These proposals are not only based on previous guidelines for animal specifications, but also on Instructions for Authors from journals specialized in Laboratory Animal Science. These proposals are classified into major and minor issues, and they are located in the corresponding parts of the article, as defined by the Introduction, Methods, Results, and Discussion (IMRAD) method. (c) 2005 Prous Science. All rights reserved.

  7. Crack Closure Effects on Fatigue Crack Propagation Rates: Application of a Proposed Theoretical Model

    Directory of Open Access Journals (Sweden)

    José A. F. O. Correia

    2016-01-01

    Full Text Available Structural design taking into account fatigue damage requires a thorough knowledge of the behaviour of materials. In addition to the monotonic behaviour of the materials, it is also important to assess their cyclic response and fatigue crack propagation behaviour under constant and variable amplitude loading. Materials whenever subjected to fatigue cracking may exhibit mean stress effects as well as crack closure effects. In this paper, a theoretical model based on the same initial assumptions of the analytical models proposed by Hudak and Davidson and Ellyin is proposed to estimate the influence of the crack closure effects. This proposal based further on Walker’s propagation law was applied to the P355NL1 steel using an inverse analysis (back-extrapolation of experimental fatigue crack propagation results. Based on this proposed model it is possible to estimate the crack opening stress intensity factor, Kop, the relationship between U=ΔKeff/ΔK quantity and the stress intensity factor, the crack length, and the stress ratio. This allows the evaluation of the influence of the crack closure effects for different stress ratio levels, in the fatigue crack propagation rates. Finally, a good agreement is found between the proposed theoretical model and the analytical models presented in the literature.

  8. Hyperpolarization-Activated Current, , in Mathematical Models of Rabbit Sinoatrial Node Pacemaker Cells

    Directory of Open Access Journals (Sweden)

    Arie O. Verkerk

    2013-01-01

    Full Text Available A typical feature of sinoatrial (SA node pacemaker cells is the presence of an ionic current that activates upon hyperpolarization. The role of this hyperpolarization-activated current, , which is also known as the “funny current” or “pacemaker current,” in the spontaneous pacemaker activity of SA nodal cells remains a matter of intense debate. Whereas some conclude that plays a fundamental role in the generation of pacemaker activity and its rate control, others conclude that the role of is limited to a modest contribution to rate control. The ongoing debate is often accompanied with arguments from computer simulations, either to support one's personal view or to invalidate that of the antagonist. In the present paper, we review the various mathematical descriptions of that have been used in computer simulations and compare their strikingly different characteristics with our experimental data. We identify caveats and propose a novel model for based on our experimental data.

  9. Critical state model with anisotropic critical current density

    CERN Document Server

    Bhagwat, K V; Ravikumar, G

    2003-01-01

    Analytical solutions of Bean's critical state model with critical current density J sub c being anisotropic are obtained for superconducting cylindrical samples of arbitrary cross section in a parallel geometry. We present a method for calculating the flux fronts and magnetization curves. Results are presented for cylinders with elliptical cross section with a specific form of the anisotropy. We find that over a certain range of the anisotropy parameter the flux fronts have shapes similar to those for an isotropic sample. However, in general, the presence of anisotropy significantly modifies the shape of the flux fronts. The field for full flux penetration also depends on the anisotropy parameter. The method is extended to the case of anisotropic J sub c that also depends on the local field B, and magnetization hysteresis curves are presented for typical values of the anisotropy parameter for the case of |J sub c | that decreases exponentially with |B|.

  10. High voltage direct current modelling in optimal power flows

    Energy Technology Data Exchange (ETDEWEB)

    Ambriz-Perez, H. [Comision Federal de Electricidad, Mexico, Unidad de Ingenieria Especializada, Rio Rodano No. 14 - Piso 10, Sala 1002, Col. Cuauhtemoc, C.P. 06598, Mexico, D.F. (Mexico); Acha, E. [Department of Electronics and Electrical Engineering, University of Glasgow, Glasgow G128LT, Scotland (United Kingdom); Fuerte-Esquivel, C.R. [Faculty of Electrical Engineering, Universidad Michoacana de San Nicolas de Hidalgo, Morelia 58030, Michoacan (Mexico)

    2008-03-15

    Two-terminal high voltage direct current (HVDC) transmission links are in operation throughout the world. They are key elements in electrical power networks; their representation is oversimplified or ignored in most power system studies. This is particularly the case in Optima Power Flow (OPF) studies. Hence, an OPF program has been extended to incorporate HVDC links, taking due account of overlapping and power transfer control characteristics. This is a new development in Newton Optimal Power Flows, where the converter equations are included directly in the matrix W. The method is indeed a unified one since the solution vector is extended to accommodate the DC variables. The HVDC link model correctly takes into account the relevant DC limit variables. The impact of HVDC links on OPF studies is illustrated by numeric examples, which includes a 5-node system, the AEP 14-node and a 166-node system. (author)

  11. Wall conditioning for ITER: Current experimental and modeling activities

    Energy Technology Data Exchange (ETDEWEB)

    Douai, D., E-mail: david.douai@cea.fr [CEA, IRFM, Association Euratom-CEA, 13108 St. Paul lez Durance (France); Kogut, D. [CEA, IRFM, Association Euratom-CEA, 13108 St. Paul lez Durance (France); Wauters, T. [LPP-ERM/KMS, Association Belgian State, 1000 Brussels (Belgium); Brezinsek, S. [FZJ, Institut für Energie- und Klimaforschung Plasmaphysik, 52441 Jülich (Germany); Hagelaar, G.J.M. [Laboratoire Plasma et Conversion d’Energie, UMR5213, Toulouse (France); Hong, S.H. [National Fusion Research Institute, Daejeon 305-806 (Korea, Republic of); Lomas, P.J. [CCFE, Culham Science Centre, OX14 3DB Abingdon (United Kingdom); Lyssoivan, A. [LPP-ERM/KMS, Association Belgian State, 1000 Brussels (Belgium); Nunes, I. [Associação EURATOM-IST, Instituto de Plasmas e Fusão Nuclear, 1049-001 Lisboa (Portugal); Pitts, R.A. [ITER International Organization, F-13067 St. Paul lez Durance (France); Rohde, V. [Max-Planck-Institut für Plasmaphysik, 85748 Garching (Germany); Vries, P.C. de [ITER International Organization, F-13067 St. Paul lez Durance (France)

    2015-08-15

    Wall conditioning will be required in ITER to control fuel and impurity recycling, as well as tritium (T) inventory. Analysis of conditioning cycle on the JET, with its ITER-Like Wall is presented, evidencing reduced need for wall cleaning in ITER compared to JET–CFC. Using a novel 2D multi-fluid model, current density during Glow Discharge Conditioning (GDC) on the in-vessel plasma-facing components (PFC) of ITER is predicted to approach the simple expectation of total anode current divided by wall surface area. Baking of the divertor to 350 °C should desorb the majority of the co-deposited T. ITER foresees the use of low temperature plasma based techniques compatible with the permanent toroidal magnetic field, such as Ion (ICWC) or Electron Cyclotron Wall Conditioning (ECWC), for tritium removal between ITER plasma pulses. Extrapolation of JET ICWC results to ITER indicates removal comparable to estimated T-retention in nominal ITER D:T shots, whereas GDC may be unattractive for that purpose.

  12. BLAM (Benthic Light Availability Model): A Proposed Model of Hydrogeomorphic Controls on Light in Rivers

    Science.gov (United States)

    Julian, J. P.; Doyle, M. W.; Stanley, E. H.

    2006-12-01

    Light is vital to the dynamics of aquatic ecosystems. It drives photosynthesis and photochemical reactions, affects thermal structure, and influences behavior of aquatic biota. Despite the fundamental role of light to riverine ecosystems, light studies in rivers have been mostly neglected because i) boundary conditions (e.g., banks, riparian vegetation) make ambient light measurements difficult, and ii) the optical water quality of rivers is highly variable and difficult to characterize. We propose a benthic light availability model (BLAM) that predicts the percent of incoming photosynthetically active radiation (PAR) available at the river bed. BLAM was developed by quantifying light attenuation of the five hydrogeomorphic controls that dictate riverine light availability: topography, riparian vegetation, channel geometry, optical water quality, and water depth. BLAM was calibrated using hydrogeomorphic data and light measurements from two rivers: Deep River - a 5th-order, turbid river in central North Carolina, and Big Spring Creek - a 2nd-order, optically clear stream in central Wisconsin. We used a series of four PAR sensors to measure i) above-canopy PAR, ii) PAR above water surface, iii) PAR below water surface, and iv) PAR on stream bed. These measurements were used to develop empirical light attenuation coefficients, which were then used in combination with optical water quality measurements, shading analyses, channel surveys, and flow records to quantify the spatial and temporal variability in riverine light availability. Finally, we apply BLAM to the Baraboo River - a 6th-order, 120-mile, unimpounded river in central Wisconsin - in order to characterize light availability along the river continuum (from headwaters to mouth).

  13. Atlantis model outputs - Developing end-to-end models of the California Current Large Marine Ecosystem

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The purpose of this project is to develop spatially discrete end-to-end models of the California Current LME, linking oceanography, biogeochemistry, food web...

  14. Comparing Symptoms of Autism Spectrum Disorders Using the Current "DSM-IV-TR" Diagnostic Criteria and the Proposed "DSM-V" Diagnostic Criteria

    Science.gov (United States)

    Worley, Julie A.; Matson, Johnny L.

    2012-01-01

    The American Psychiatric Association has proposed major revisions for the diagnostic category encompassing Autism Spectrum Disorders (ASD), which will reportedly increase the specificity and maintain the sensitivity of diagnoses. As a result, the aim of the current study was to compare symptoms of ASD in children and adolescents (N = 208) who met…

  15. Implementing a Grant Proposal Writing Exercise in Undergraduate Science Courses to Incorporate Real-World Applications and Critical Analysis of Current Literature

    Science.gov (United States)

    Cole, Kathryn E.; Inada, Maki; Smith, Andrew M.; Haaf, Michael P.

    2013-01-01

    Writing is an essential part of a successful career in science. As such, many undergraduate science courses have begun to implement writing assignments that reflect "real-world" applications and focus on a critical analysis of current literature; these assignments are often in the form of a review or a research proposal. The…

  16. Comparing Symptoms of Autism Spectrum Disorders Using the Current "DSM-IV-TR" Diagnostic Criteria and the Proposed "DSM-V" Diagnostic Criteria

    Science.gov (United States)

    Worley, Julie A.; Matson, Johnny L.

    2012-01-01

    The American Psychiatric Association has proposed major revisions for the diagnostic category encompassing Autism Spectrum Disorders (ASD), which will reportedly increase the specificity and maintain the sensitivity of diagnoses. As a result, the aim of the current study was to compare symptoms of ASD in children and adolescents (N = 208) who met…

  17. 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.

  18. A frailty model approach for regression analysis of multivariate current status data.

    Science.gov (United States)

    Chen, Man-Hua; Tong, Xingwei; Sun, Jianguo

    2009-11-30

    This paper discusses regression analysis of multivariate current status failure time data (The Statistical Analysis of Interval-censoring Failure Time Data. Springer: New York, 2006), which occur quite often in, for example, tumorigenicity experiments and epidemiologic investigations of the natural history of a disease. For the problem, several marginal approaches have been proposed that model each failure time of interest individually (Biometrics 2000; 56:940-943; Statist. Med. 2002; 21:3715-3726). In this paper, we present a full likelihood approach based on the proportional hazards frailty model. For estimation, an Expectation Maximization (EM) algorithm is developed and simulation studies suggest that the presented approach performs well for practical situations. The approach is applied to a set of bivariate current status data arising from a tumorigenicity experiment.

  19. Data Center IT Equipment Energy Assessment Tools: Current State of Commercial Tools, Proposal for a Future Set of Assessment Tools

    Energy Technology Data Exchange (ETDEWEB)

    Radhakrishnan, Ben D. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); National Univ., San Diego, CA (United States). School of Engineering

    2012-06-30

    This research project, which was conducted during the Summer and Fall of 2011, investigated some commercially available assessment tools with a focus on IT equipment to see if such tools could round out the DC Pro tool suite. In this research, the assessment capabilities of the various tools were compiled to help make “non-biased” information available to the public. This research should not be considered to be exhaustive on all existing vendor tools although a number of vendors were contacted. Large IT equipment OEM’s like IBM and Dell provide their proprietary internal automated software which does not work on any other IT equipment. However, found two companies with products that showed promise in performing automated assessments for IT equipment from different OEM vendors. This report documents the research and provides a list of software products reviewed, contacts and websites, product details, discussions with specific companies, a set of recommendations, and next steps. As a result of this research, a simple 3-level approach to an IT assessment tool is proposed along with an example of an assessment using a simple IT equipment data collection tool (Level 1, spreadsheet). The tool has been reviewed with the Green Grid and LBNL staff. The initial feedback has been positive although further refinement to the tool will be necessary. Proposed next steps include a field trial of at least two vendors’ software in two different data centers with an objective to prove the concept, ascertain the extent of energy and computational assessment, ease of installation and opportunities for continuous improvement. Based on the discussions, field trials (or case studies) are proposed with two vendors – JouleX (expected to be completed in 2012) and Sentilla.

  20. Eddy Current Inversion Models for Estimating Dimensions of Defects in Multilayered Structures

    Directory of Open Access Journals (Sweden)

    Bo Ye

    2014-01-01

    Full Text Available In eddy current nondestructive evaluation, one of the principal challenges is to determine the dimensions of defects in multilayered structures from the measured signals. It is a typical inverse problem which is generally considered to be nonlinear and ill-posed. In the paper, two effective approaches have been proposed to estimate the defect dimensions. The first one is a partial least squares (PLS regression method. The second one is a kernel partial least squares (KPLS regression method. The experimental research is carried out. In experiments, the eddy current signals responding to magnetic field changes are detected by a giant magnetoresistive (GMR sensor and preprocessed for noise elimination using a wavelet packet analysis (WPA method. Then, the proposed two approaches are used to construct the inversion models of defect dimension estimation. Finally, the estimation results are analyzed. The performance comparison between the proposed two approaches and the artificial neural network (ANN method is presented. The comparison results demonstrate the feasibility and validity of the proposed two methods. Between them, the KPLS regression method gives a better prediction performance than the PLS regression method at present.

  1. Analytical Model for Voltage-Dependent Photo and Dark Currents in Bulk Heterojunction Organic Solar Cells

    Directory of Open Access Journals (Sweden)

    Mesbahus Saleheen

    2016-05-01

    Full Text Available A physics-based explicit mathematical model for the external voltage-dependent forward dark current in bulk heterojunction (BHJ organic solar cells is developed by considering Shockley-Read-Hall (SRH recombination and solving the continuity equations for both electrons and holes. An analytical model for the external voltage-dependent photocurrent in BHJ organic solar cells is also proposed by incorporating exponential photon absorption, dissociation efficiency of bound electron-hole pairs (EHPs, carrier trapping, and carrier drift and diffusion in the photon absorption layer. Modified Braun’s model is used to compute the electric field-dependent dissociation efficiency of the bound EHPs. The overall net current is calculated considering the actual solar spectrum. The mathematical models are verified by comparing the model calculations with various published experimental results. We analyze the effects of the contact properties, blend compositions, charge carrier transport properties (carrier mobility and lifetime, and cell design on the current-voltage characteristics. The power conversion efficiency of BHJ organic solar cells mostly depends on electron transport properties of the acceptor layer. The results of this paper indicate that improvement of charge carrier transport (both mobility and lifetime and dissociation of bound EHPs in organic blend are critically important to increase the power conversion efficiency of the BHJ solar cells.

  2. The Geometrization of Matter Proposal in the Barrett-Crane Model and Resolution of Cosmological Problems

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, Stephon

    2003-07-15

    We give an overview of the current issues in early universe cosmology and consider the potential resolution of these issues in an as yet nascent spin foam cosmology. The model is the Barrett-Crane Model for quantum gravity along with a generalization of manifold complexes to complexes including conical singularities.

  3. Current amplification models of sensorineurall and conductive hearing loss

    Directory of Open Access Journals (Sweden)

    Ostojić Sanja

    2012-01-01

    Full Text Available The main function of a hearing aid is to improve auditory and language abilities of hearing impaired users. The amplification model has to be adapted according to age, degree and type of hearing loss. The goal of this paper is to analyze the current amplification models of sensorineural and conductive hearing loss which can provide a high quality of speech perception and sounds at any degree of hearing loss. The BAHA is a surgically implantable system for treatment of conductive hearing loss that works through direct bone conduction. BAHA is used to help people with chronic ear infections, congenital external auditory canal atresia and single sided deafness who cannot benefit from conventional hearing aids. The last generation of hearing aid for sensorineural hearing loss is cochlear implant. Bimodal amplification improves binaural hearing. Hearing aids alone do not make listening easier in all situations. The things that can interfere with listening are background noises, distance from a sound and reverberation or echo. The device used most often today is the Frequency Modulated (FM system.

  4. A geomagnetically induced current warning system: model development and validation

    Science.gov (United States)

    McKay, A.; Clarke, E.; Reay, S.; Thomson, A.

    Geomagnetically Induced Currents (GIC), which can flow in technological systems at the Earth's surface, are a consequence of magnetic storms and Space Weather. A well-documented practical problem for the power transmission industry is that GIC can affect the lifetime and performance of transformers within the power grid. Operational mitigation is widely considered to be one of the best strategies to manage the Space Weather and GIC risk. Therefore in the UK a magnetic storm warning and GIC monitoring and analysis programme has been under development by the British Geological Survey and Scottish Power plc (the power grid operator for Central Scotland) since 1999. Under the auspices of the European Space Agency's service development activities BGS is developing the capability to meet two key user needs that have been identified. These needs are, firstly, the development of a near real-time solar wind shock/ geomagnetic storm warning, based on L1 solar wind data and, secondly, the development of an integrated surface geo-electric field and power grid network model that should allow prediction of GIC throughout the power grid in near real time. While the final goal is a `seamless package', the components of the package utilise diverse scientific techniques. We review progress to date with particular regard to the validation of the individual components of the package. The Scottish power grid response to the October 2003 magnetic storms is also discussed and model and validation data are presented.

  5. The Motivational Knowledge Management Model: proposal to apply it in the library sector

    Directory of Open Access Journals (Sweden)

    Daniel López-Fernández

    2016-12-01

    Full Text Available In professional environments, attention paid to aspects such as supervisory styles, interpersonal relationships and workers eagerness can have a positive impact on employee motivation and, consequently, on their performance and well-being. To achieve this, knowledge management models such as those presented here can be applied. This model generates diagnoses of motivation and recommendations for improvement, both systematically and scientifically. Consequently, it is especially useful for managers and human resource departments. The proposed model can be adapted to different kinds of professional groups, including those in library and documentation services. The suitability, reliability and usefulness of the proposed model have been empirically checked through case studies with 92 students and 166 professionals. The positive results allow us to conclude that the model is effective and useful for assessing and improving motivation.

  6. Proposed SPAR Modeling Method for Quantifying Time Dependent Station Blackout Cut Sets

    Energy Technology Data Exchange (ETDEWEB)

    John A. Schroeder

    2010-06-01

    Abstract: The U.S. Nuclear Regulatory Commission’s (USNRC’s) Standardized Plant Analysis Risk (SPAR) models and industry risk models take similar approaches to analyzing the risk associated with loss of offsite power and station blackout (LOOP/SBO) events at nuclear reactor plants. In both SPAR models and industry models, core damage risk resulting from a LOOP/SBO event is analyzed using a combination of event trees and fault trees that produce cut sets that are, in turn, quantified to obtain a numerical estimate of the resulting core damage risk. A proposed SPAR method for quantifying the time-dependent cut sets is sometimes referred to as a convolution method. The SPAR method reflects assumptions about the timing of emergency diesel failures, the timing of subsequent attempts at emergency diesel repair, and the timing of core damage that may be different than those often used in industry models. This paper describes the proposed SPAR method.

  7. Combining estimates of interest in prognostic modelling studies after multiple imputation: current practice and guidelines

    Directory of Open Access Journals (Sweden)

    Holder Roger L

    2009-07-01

    Full Text Available Abstract Background Multiple imputation (MI provides an effective approach to handle missing covariate data within prognostic modelling studies, as it can properly account for the missing data uncertainty. The multiply imputed datasets are each analysed using standard prognostic modelling techniques to obtain the estimates of interest. The estimates from each imputed dataset are then combined into one overall estimate and variance, incorporating both the within and between imputation variability. Rubin's rules for combining these multiply imputed estimates are based on asymptotic theory. The resulting combined estimates may be more accurate if the posterior distribution of the population parameter of interest is better approximated by the normal distribution. However, the normality assumption may not be appropriate for all the parameters of interest when analysing prognostic modelling studies, such as predicted survival probabilities and model performance measures. Methods Guidelines for combining the estimates of interest when analysing prognostic modelling studies are provided. A literature review is performed to identify current practice for combining such estimates in prognostic modelling studies. Results Methods for combining all reported estimates after MI were not well reported in the current literature. Rubin's rules without applying any transformations were the standard approach used, when any method was stated. Conclusion The proposed simple guidelines for combining estimates after MI may lead to a wider and more appropriate use of MI in future prognostic modelling studies.

  8. Proposing a two-level stochastic model for epileptic seizure genesis.

    Science.gov (United States)

    Shayegh, F; Sadri, S; Amirfattahi, R; Ansari-Asl, K

    2014-02-01

    By assuming the brain as a multi-stable system, different scenarios have been introduced for transition from normal to epileptic state. But, the path through which this transition occurs is under debate. In this paper a stochastic model for seizure genesis is presented that is consistent with all scenarios: a two-level spontaneous seizure generation model is proposed in which, in its first level the behavior of physiological parameters is modeled with a stochastic process. The focus is on some physiological parameters that are essential in simulating different activities of ElectroEncephaloGram (EEG), i.e., excitatory and inhibitory synaptic gains of neuronal populations. There are many depth-EEG models in which excitatory and inhibitory synaptic gains are the adjustable parameters. Using one of these models at the second level, our proposed seizure generator is complete. The suggested stochastic model of first level is a hidden Markov process whose transition matrices are obtained through analyzing the real parameter sequences of a seizure onset area. These real parameter sequences are estimated from real depth-EEG signals via applying a parameter identification algorithm. In this paper both short-term and long-term validations of the proposed model are done. The long-term synthetic depth-EEG signals simulated by this model can be taken as a suitable tool for comparing different seizure prediction algorithms.

  9. Effect of Upward Internal Flow on Dynamics of Riser Model Subject to Shear Current

    Institute of Scientific and Technical Information of China (English)

    CHEN Zheng-shou; KIM Wu-joan; XIONG Cong-bo

    2012-01-01

    Numerical study about vortex-induced vibration (VIV) related to a flexible riser model in consideration of internal flow progressing inside has been performed.The main objective of this work is to investigate the coupled fluid-structure interaction (FSI) taking place between tensioned riser model,external shear current and upward-progressing internal flow (from ocean bottom to surface).A CAE technology behind the current research which combines structural softwàre with the CFD technology has been proposed.According to the result from dynamic analysis,it has been found that the existence of upward-progressing internal flow does play an important role in determining the vibration mode (/dominant frequency),vibration intensity and the magnitude of instantaneous vibration amplitude,when the velocity ratio of internal flow against external current is relatively high.As a rule,the larger the velocity of internal flow is,the more it contributes to the dynamic vibration response of the flexible riser model.In addition,multi-modal vibration phenomenon has been widely observed,for asymmetric curvature along the riser span emerges in the case of external shear current being imposed.

  10. Dust Composition in Climate Models: Current Status and Prospects

    Science.gov (United States)

    Pérez García-Pando, C.; Miller, R. L.; Perlwitz, J. P.; Kok, J. F.; Scanza, R.; Mahowald, N. M.

    2015-12-01

    Mineral dust created by wind erosion of soil particles is the dominant aerosol by mass in the atmosphere. It exerts significant effects on radiative fluxes, clouds, ocean biogeochemistry, and human health. Models that predict the lifecycle of mineral dust aerosols generally assume a globally uniform mineral composition. However, this simplification limits our understanding of the role of dust in the Earth system, since the effects of dust strongly depend on the particles' physical and chemical properties, which vary with their mineral composition. Hence, not only a detailed understanding of the processes determining the dust emission flux is needed, but also information about its size dependent mineral composition. Determining the mineral composition of dust aerosols is complicated. The largest uncertainty derives from the current atlases of soil mineral composition. These atlases provide global estimates of soil mineral fractions, but they are based upon massive extrapolation of a limited number of soil samples assuming that mineral composition is related to soil type. This disregards the potentially large variability of soil properties within each defined soil type. In addition, the analysis of these soil samples is based on wet sieving, a technique that breaks the aggregates found in the undisturbed parent soil. During wind erosion, these aggregates are subject to partial fragmentation, which generates differences on the size distribution and composition between the undisturbed parent soil and the emitted dust aerosols. We review recent progress on the representation of the mineral and chemical composition of dust in climate models. We discuss extensions of brittle fragmentation theory to prescribe the emitted size-resolved dust composition, and we identify key processes and uncertainties based upon model simulations and an unprecedented compilation of observations.

  11. Lessons from the Current Japanese Triple Helix Model

    Directory of Open Access Journals (Sweden)

    Mitsuaki Hosono

    2013-01-01

    Full Text Available Since mid-1990s, the Japanese government has encouraged university-industry collaboration to foster innovations for economic growth. Learning from the American licensing model of technology transfer, Japanese Bay-Dole Act and TLO (Technology Licensing Organization Act were enacted in late 1990s. In addition, the corporatization of Japanese National Universities (JNUs in 2004 spurred their technology-transfer activities to obtain external funds. As a result, more than 50 TLOs has been established since FY1998, and also the number of patent application and licensed patents were increased at JUNs rapidly after FY2004. However, the licensing income has been stayed poor and some of TLOs were abolished. There are few evidences that the introduction of licensing model of technology transfer into Japan could contribute to innovation properly. Therefore, this study will try to clarify if licensing model of technology transfer work in Japan by analyzing the Japanese National University (JNU patent. There are 20,485 applied patent, which invented by JNU’s researcher(s from FY2004 to 2007. 38% of them were applied by solely by JNUs and 52% were by JNU and Private Firms etc. In the Japanese Patent Act, jointly applied patents are not licensed to the third party without the consent of co-applicant(s. Hence, more than half of the patent invented by JNU researchers is not basically used for patent licensing. Consequently, JNUs and TLOs face difficulties in patent licensing under the current Patent Act. Keywords: Technology Transfer, TLO, University Patent, Japan

  12. A Summary of Proposed Changes to the Current ICARTT Format Standards and their Implications to Future Airborne Studies

    Science.gov (United States)

    Northup, Emily; Benson Early, Amanda; Beach, Aubrey; Wang, Dali; Kusterer, John; Quam, Brandi; Chen, Gao

    2015-01-01

    The Atmospheric Science Data Center (ASDC) at NASA Langley Research Center is responsible for the ingest, archive, and distribution of NASA Earth Science data in the areas of radiation budget, clouds, aerosols, and tropospheric chemistry. The ASDC specializes in atmospheric data that is important to understanding the causes and processes of global climate change and the consequences of human activities on the climate. The ASDC currently supports more than 44 projects and has over 1,700 archived data sets, which increase daily. ASDC customers include scientists, researchers, federal, state, and local governments, academia, industry, and application users, the remote sensing community, and the general public.

  13. A Self-Report Measure for the ICD-11 Dimensional Trait Model Proposal: The Personality Inventory for ICD-11.

    Science.gov (United States)

    Oltmanns, Joshua R; Widiger, Thomas A

    2017-02-23

    Proposed for the 11th edition of the World Health Organization's International Classification of Diseases (ICD-11) is a dimensional trait model for the classification of personality disorder (Tyrer, Reed, & Crawford, 2015). The ICD-11 proposal consists of 5 broad domains: negative affective, detachment, dissocial, disinhibition, and anankastic (Mulder, Horwood, Tyrer, Carter, & Joyce, 2016). Several field trials have examined this proposal, yet none has included a direct measure of the trait model. The purpose of the current study was to develop and provide initial validation for the Personality Inventory for ICD-11 (PiCD), a self-report measure of this proposed 5-domain maladaptive trait model. Item selection and scale construction proceeded through 3 initial data collections assessing potential item performance. Two subsequent studies were conducted for scale validation. In Study 1, the PiCD was evaluated in a sample of 259 MTurk participants (who were or had been receiving mental health treatment) with respect to 2 measures of general personality structure: The Eysenck Personality Questionnaire-Revised and the 5-Dimensional Personality Test. In Study 2, the PiCD was evaluated in an additional sample of 285 participants with respect to 2 measures of maladaptive personality traits: The Personality Inventory for DSM-5 and the Computerized Adaptive Test for Personality Disorders. Study 3 provides an item-level exploratory structural equation model with the combined samples from Studies 1 and 2. The results are discussed with respect to the validity of the measure and the potential benefits for future research in having a direct, self-report measure of the ICD-11 trait proposal. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  14. Great expectations: using an analysis of current practices to propose a framework for the undergraduate inorganic curriculum.

    Science.gov (United States)

    Reisner, Barbara A; Smith, Sheila R; Stewart, Joanne L; Raker, Jeffrey R; Crane, Johanna L; Sobel, Sabrina G; Pesterfield, Lester L

    2015-09-21

    The undergraduate inorganic chemistry curriculum in the United States mirrors the broad diversity of the inorganic research community and poses a challenge for the development of a coherent curriculum that is thorough, rigorous, and engaging. A recent large survey of the inorganic community has provided information about the current organization and content of the inorganic curriculum from an institutional level. The data reveal shared "core" concepts that are broadly taught, with tremendous variation in content coverage beyond these central ideas. The data provide an opportunity for a community-driven discussion about how the American Chemical Society's Committee on Professional Training's vision of a foundation and in-depth course for each of the five subdisciplines maps onto an inorganic chemistry curriculum that is consistent in its coverage of the core inorganic concepts, yet reflects the diversity and creativity of the inorganic community. The goal of this Viewpoint is to present the current state of the diverse undergraduate curriculum and lay a framework for an effective and engaging curriculum that illustrates the essential role inorganic chemistry plays within the chemistry community.

  15. Proposal for the Award of a Contract for the Supply of High Precision 120A dc Current Transducersfor Power Converters

    CERN Document Server

    2002-01-01

    This document concerns the award of a contract for the supply of 2430 high precision 120A DC current transducers for LHC power converters. Following a market survey carried out among 117 firms in seventeen Member States, a call for tenders (IT-2912/SL/LHC) was sent on 30 May 2002 to three firms, in three Member States. By the closing date, CERN had received three tenders from three firms in three Member States. The Finance Committee is invited to agree to the negotiation of a contract with KG RITZ MESSWANDLER (DE), the lowest bidder, for the supply of 2430 high precision 120A DC current transducers for LHC power converters for a total amount of 727 495 euros (1 069 200 Swiss francs), not subject to revision, with an option for up to 250 spare units for an additional amount of 79 609 euros (117 000 Swiss francs), not subject to revision, bringing the total amount to 807 104 euros (1 186 200 Swiss francs), not subject to revision. The rate of exchange used is that stipulated in the tender. The firm has indicate...

  16. Improving the Goodness-of-Fits Associated with the Current and Proposed Combat Active Replacement Factors (CARF) Methodology

    Science.gov (United States)

    2012-03-01

    Likelihood Observations (or Sum Wgts) = 84 Whole Model Test L-R Model -Loglikelihood ChiSquare OF Prob>ChiSq Difference 0.17655182 0.3531 3 0.9498...Full 13.874747 Reduced Goodness Of Fit Statistic Pearson Deviance AICc 36.2558 14.0512988 ChiSquare 1.1301 1.1236 Effect Tests Source...AAO_TOTAL BEST_COST AAO_ TOTAL*BEST _COST Parameter Estimates OF Prob>ChiSq 80 1.0000 80 1.0000 L-R OF ChiSquare Prob>ChiSq 0.1814729 0.6701

  17. Blended learning in anesthesia education: current state and future model.

    Science.gov (United States)

    Kannan, Jaya; Kurup, Viji

    2012-12-01

    Educators in anesthesia residency programs across the country are facing a number of challenges as they attempt to integrate blended learning techniques in their curriculum. Compared with the rest of higher education, which has made advances to varying degrees in the adoption of online learning anesthesiology education has been sporadic in the active integration of blended learning. The purpose of this review is to discuss the challenges in anesthesiology education and relevance of the Universal Design for Learning framework in addressing them. There is a wide chasm between student demand for online education and the availability of trained faculty to teach. The design of the learning interface is important and will significantly affect the learning experience for the student. This review examines recent literature pertaining to this field, both in the realm of higher education in general and medical education in particular, and proposes the application of a comprehensive learning model that is new to anesthesiology education and relevant to its goals of promoting self-directed learning.

  18. Proposed Hydrodynamic Model Improves Resolution of Species-Specific Responses to Drought and Disturbance

    Science.gov (United States)

    Matheny, A. M.; Bohrer, G.; Fiorella, R.; Mirfenderesgi, G.

    2015-12-01

    Plant functional types in land surface models (LSMs) are broadly defined, and often represent species with different physiologies within the same category. For example, trees of opposing hydraulic strategies and traits are commonly grouped together, as is the case of red oak and red maple. As a result, LSMs generate typical patterns of errors in predictions of transpiration and production. We studied sap flux, stem water storage, stomatal conductance, photosynthesis, rooting depth, and bole growth of these species at disturbed and undisturbed field sites in Michigan. Species-specific differences significantly impact temporal patterns of stomatal conductance and overall transpiration responses to both drought and disturbance. During drought, maples relied heavily on stem-stored water, while oaks did not. After disturbance, oaks increased stomatal conductance while maple conductance declined. Isotopic analysis of xylem water revealed that oak roots can access a deep groundwater source, which maple roots cannot. This deep rooting strategy permits transpiration and growth to continue in oaks during periods of water limitation, even when maples cease transpiration. Using 16 years of bole growth data, we show that maple growth is strongly correlated with mean annual precipitation, yet oak growth is not. We propose a framework to incorporate these species-specific differences into LSMs using the Finite-Element Tree-Crown Hydrodynamics model version 2 (FETCH2) that resolves the fast dynamics and diurnal hysteresis of stomatal conductance at the tree level. FETCH2 uses atmospheric and biological forcings from the LSM, simulates water movement through trees as flow through a system of porous media conduits, and calculates realistic hydraulic restrictions to stomatal conductance. This model replaces the current, non-physical link which empirically connects soil moisture to stomatal conductance in LSMs. FETCH2 resolved transpiration is then easily scaled to the plot level

  19. Stable explicit coupling of the Yee scheme with a linear current model in fluctuating magnetized plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Filipe da, E-mail: tanatos@ipfn.ist.utl.pt [Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa (Portugal); Pinto, Martin Campos, E-mail: campos@ann.jussieu.fr [CNRS, UMR 7598, Laboratoire Jacques-Louis Lions, F-75005, Paris (France); Sorbonne Universités, UPMC Univ Paris 06, UMR 7598, Laboratoire Jacques-Louis Lions, F-75005, Paris (France); Després, Bruno, E-mail: despres@ann.jussieu.fr [Sorbonne Universités, UPMC Univ Paris 06, UMR 7598, Laboratoire Jacques-Louis Lions, F-75005, Paris (France); CNRS, UMR 7598, Laboratoire Jacques-Louis Lions, F-75005, Paris (France); Heuraux, Stéphane, E-mail: stephane.heuraux@univ-lorraine.fr [Institut Jean Lamour, UMR 7198, CNRS – University Lorraine, Vandoeuvre (France)

    2015-08-15

    This work analyzes the stability of the Yee scheme for non-stationary Maxwell's equations coupled with a linear current model with density fluctuations. We show that the usual procedure may yield unstable scheme for physical situations that correspond to strongly magnetized plasmas in X-mode (TE) polarization. We propose to use first order clustered discretization of the vectorial product that gives back a stable coupling. We validate the schemes on some test cases representative of direct numerical simulations of X-mode in a magnetic fusion plasma including turbulence.

  20. Model Predictive Current Control for High-Power Grid-Connected Converters with Output LCL Filter

    DEFF Research Database (Denmark)

    Delpino, Hernan Anres Miranda; Teodorescu, Remus; Rodriguez, Pedro

    2009-01-01

    A model predictive control strategy for a highpower, grid connected 3-level neutral clamped point converter is presented. Power losses constraints set a limit on commutation losses so reduced switching frequency is required, thus producing low frequency current harmonics. To reduce these harmonics...... an LCL filter is used. The proposed control strategy allows control of the active and reactive power fed into the grid, reduce the switching frequency within acceptable operational margins and keep balance of the DC-link capacitor voltages while avoiding excitation of the filter resonance frequencies....

  1. Human Missions to Near-Earth Asteroids: An Update on NASA's Current Status and Proposed Activities for Small Body Exploration

    Science.gov (United States)

    Abell, P. A.; Mazanek, D. D.; Barbee, B. W.; Mink, R. G.; Landis, R. R.; Adamo, D. R.; Johnson, L. N.; Yeomans, D. K.; Reeves, D. M.; Larman, K. T.; Drake, B. G.; Friedensen, V. P.

    2012-01-01

    Over the past several years, much attention has been focused on the human exploration of near-Earth asteroids (NEAs). Two independent NASA studies examined the feasibility of sending piloted missions to NEAs, and in 2009, the Augustine Commission identified NEAs as high profile destinations for human exploration missions beyond the Earth-Moon system as part of the Flexible Path. More recently the current U.S. presidential administration directed NASA to include NEAs as destinations for future human exploration with the goal of sending astronauts to a NEA in the mid to late 2020s. This directive became part of the official National Space Policy of the United States of America as of June 28, 2010.

  2. Applying the Many-Facet Rasch Measurement Model to Explore Reviewer Ratings of Conference Proposals.

    Science.gov (United States)

    Bradley, Kelly D; Peabody, Michael R; Mensah, Richard K

    For academic conferences, when proposals are submit they are often judged using a rating scale on identified criterion by reviewers who have a shared interest and expertise in the area under consideration. Given the multiple and varied reviewers, an analysis of psychometric properties like rater severity and consistency are important. However, many of the problems that plague the conference proposal selection process are the same issues that plague survey research: rater bias/severity, misuse of rating scale, and the use of raw scores as measures. We propose the use of the many-facet Rasch measurement model (MFRM) to combat these shortcomings and improve the quality of the conference proposal selection process. A set of American Educational Research Association (AERA) Special Interest Group (SIG) proposals is used as an example. The results identify proposals that were accepted based on calculating the mean of summed raw scores, but when MFRM is applied to adjust for judge severity the rank order of the proposals is substantially altered.

  3. Proposal of a Model for effective Management and Development of virtual Teams

    Directory of Open Access Journals (Sweden)

    Petr Skyrik

    2010-10-01

    Full Text Available The main aim of this paper is to present a pilot proposal of a model of “Virtual Development Management System” (ViDeMaS which will facilitate more effective management and development of virtual teams. Management and development of virtual teams is not a simple concept. It comprises a body of knowledge from a number of fields and scientific disciplines. The complexity of the concept may not be simplified as it is absolutely essential for full understanding of its nature. In order to gain better orientation in the concept, different perspectives will be used in the description of the model, which will enable us to achieve the goal of the work and to present the main results of the work (creation of a model for Virtual Development Management System. The present paper thus describes from different perspectives the proposal of a sufficiently detailed and complex model that may be utilized both on theoretical and application level.

  4. A Fractional-Flow Based Compressible Multiphase Flow Model with Newly Proposed Constitutive Retentions

    Science.gov (United States)

    Tsai, C.; Yeh, G.

    2011-12-01

    In this investigation, newly proposed constitutive retentions are implemented to a fractional-flow based compressible multiphase-phase flow model. With the new model, a compressible three-phase (water, non-aqueous phase liquid (NAPL) and air) flow problem is simulated. In fractional-flow approaches, the three mass balance equations written in terms of three phase pressures are transformed to those in terms of the total pressure, saturation of water, and saturation of total liquid. These three governing equations are discretized with the Galerkin finite element method (FEM). The resulted matrix equation is solved with Bi-CGSTAB. Several numerical experiments are presented to examine the accuracy and robustness of the proposed model. The results show the presented fractional-flow based multiphase flow model is feasible and yields physically realistic solutions for compressible three-phase flow problems in porous media.

  5. Modeling And Simulation of Speed and flux Estimator Based on Current & voltage Model

    Directory of Open Access Journals (Sweden)

    Dinesh Chandra Jain

    2011-10-01

    Full Text Available This paper introduce a estimator based on and current & voltage model used in induction motor (IM drive. The rotor speed estimation is based on the model reference adaptive system (MRAS approach. The closed loop control mechanism is based on the voltage and current model. The control and estimation algorithms utilize the synchronous coordinates as a frame of reference. A speed sensor less induction motor (IM drive with Robust control characteristics is introduced. First, a speed observation system, which is insensitive to the variations of motor parameters.

  6. Drought Duration Biases in Current Global Climate Models

    Science.gov (United States)

    Moon, Heewon; Gudmundsson, Lukas; Seneviratne, Sonia

    2016-04-01

    Several droughts in the recent past are characterized by their increased duration and intensity. In particular, substantially prolonged droughts have brought major societal and economic losses in certain regions, yet climate change projections of such droughts in terms of duration is subject to large uncertainties. This study analyzes the biases of drought duration in state-of-the-art global climate model (GCM) simulations from the 5th phase of Coupled Model Intercomparison Project (CMIP5). Drought durations are defined as negative precipitation anomalies and evaluated with three observation-based datasets in the period of 1901-2010. Large spread in biases of GCMs is commonly found in all regions, with particular strong biases in North East Brazil, Africa, Northern Australia, Central America, Central and Northern Europe, Sahel and Asia. Also in most regions, the interquartile range of bias lies below 0, meaning that the GCMs tend to underestimate drought durations. Meanwhile in some regions such as Western South America, the Amazon, Sahel, West and South Africa, and Asia, considerable inconsistency among the three observation-based datasets were found. These results indicate substantial uncertainties and errors in current GCMs for simulating drought durations as well as a large spread in observation-based datasets, both of which are found to be particularly strong in those regions that are often considered to be hot spots of projected future drying. The underlying sources of these uncertainties need to be identified in further study and will be applied to constrain GCM-based drought projections under climate change.

  7. DEVELOPING AND PROPOSING A CONCEPTUAL MODEL OF THE FLOW EXPERIENCE DURING ONLINE INFORMATION SEARCH

    Directory of Open Access Journals (Sweden)

    Lazoc Alina

    2012-07-01

    Full Text Available Information search is an essential part of the consumer`s decision making process. The online medium offers new opportunities and challenges for information search activities (in and outside the marketing context. We are interested in the way human information experiences and behaviors are affected by this. Very often online games and social web activities are perceived as challenging, engaging and enjoyable, while online information search is far below this evaluation. Our research proposal implies that using the online medium for information search may provoke enjoyable experiences through the flow state, which may in turn positively influence an individual`s exploratory information behavior and encourage his/her pro-active market behavior. The present study sets out to improve the understanding of the online medium`s impact on human`s exploratory behavior. We hypothesize that the inclusion of the online flow experience in our research model will better explain exploratory information search behaviors. A 11-component conceptual framework is proposed to explain the manifestations of flow, its personal and technological determinants and its behavioral consequence in the context of online information search. Our research has the primary purpose to present an integrated online flow model. Its secondary objective is to stimulate extended research in the area of informational behaviors in the digital age. The paper is organized in three sections. In the first section we briefly report the analysis results of the most relevant online flow theory literature and, drawing on it, we are trying to identify variables and relationships among these. In the second part we propose a research model and use prior flow models to specify a range of testable hypothesis. Drawing on the conceptual model developed, the last section of our study presents the final conclusions and proposes further steps in evaluating the model`s validity. Future research directions

  8. Consumer’s trust in Internet shopping: a modelling proposal based on the standard learning hierarchy

    OpenAIRE

    MARIO PÉREZ RONCHEL; Francisco J. Martínez López; MANUEL ORTIGUEIRA SÁNCHEZ

    2006-01-01

    This paper is placed on the framework of studies focused on analyzing the consumers’ buying behaviour on the Internet. We have based on adapting the hierarchy-of-effects model (standard learning hierarchy), in order to theoretically propose a conceptual model explaining how consumers’ beliefs —i.e. design, interaction speed, social benefits, and privacy— and attitudes toward the Internet as a communication medium can be plausible determinants of trusting in Internet shopping. Furthermore, our...

  9. The New Digital Media Value Network: Proposing an Interactive Model of Digital Media Value Activities

    Directory of Open Access Journals (Sweden)

    Sylvia Chan-Olmsted

    2016-07-01

    Full Text Available This study models the dynamic nature of today’s media markets using the framework of value-adding activities in the provision and consumption of media products. The proposed user-centric approach introduces the notion that the actions of external users, social media, and interfaces affect the internal value activities of media firms via a feedback loop, and therefore should themselves be considered value activities. The model also suggests a more comprehensive list of indicators for value assessment.

  10. Reliability of Current Biokinetic and Dosimetric Models for Radionuclides: A Pilot Study

    Energy Technology Data Exchange (ETDEWEB)

    Leggett, Richard Wayne [ORNL; Eckerman, Keith F [ORNL; Meck, Robert A. [U.S. Nuclear Regulatory Commission

    2008-10-01

    This report describes the results of a pilot study of the reliability of the biokinetic and dosimetric models currently used by the U.S. Nuclear Regulatory Commission (NRC) as predictors of dose per unit internal or external exposure to radionuclides. The study examines the feasibility of critically evaluating the accuracy of these models for a comprehensive set of radionuclides of concern to the NRC. Each critical evaluation would include: identification of discrepancies between the models and current databases; characterization of uncertainties in model predictions of dose per unit intake or unit external exposure; characterization of variability in dose per unit intake or unit external exposure; and evaluation of prospects for development of more accurate models. Uncertainty refers here to the level of knowledge of a central value for a population, and variability refers to quantitative differences between different members of a population. This pilot study provides a critical assessment of models for selected radionuclides representing different levels of knowledge of dose per unit exposure. The main conclusions of this study are as follows: (1) To optimize the use of available NRC resources, the full study should focus on radionuclides most frequently encountered in the workplace or environment. A list of 50 radionuclides is proposed. (2) The reliability of a dose coefficient for inhalation or ingestion of a radionuclide (i.e., an estimate of dose per unit intake) may depend strongly on the specific application. Multiple characterizations of the uncertainty in a dose coefficient for inhalation or ingestion of a radionuclide may be needed for different forms of the radionuclide and different levels of information of that form available to the dose analyst. (3) A meaningful characterization of variability in dose per unit intake of a radionuclide requires detailed information on the biokinetics of the radionuclide and hence is not feasible for many infrequently

  11. Dopamine Surface Modification of Trititanate Nanotubes: Proposed In-Situ Structure Models.

    Science.gov (United States)

    Liu, Ruochen; Fu, Xuejian; Wang, Congyi; Dawson, Graham

    2016-04-18

    Two models for self-assembled dopamine on the surface of trititanate nanotubes are proposed: individual monomer units linked by π-π stacking of the aromatic regions and mono-attached units interacting through hydrogen bonds. This was investigated with solid state NMR spectroscopy studies and powder X-ray diffraction.

  12. Catapult current sheet relaxation model confirmed by THEMIS observations

    Science.gov (United States)

    Machida, S.; Miyashita, Y.; Ieda, A.; Nose, M.; Angelopoulos, V.; McFadden, J. P.

    2014-12-01

    In this study, we show the result of superposed epoch analysis on the THEMIS probe data during the period from November, 2007 to April, 2009 by setting the origin of time axis to the substorm onset determined by Nishimura with THEMIS all sky imager (THEMS/ASI) data (http://www.atmos.ucla.edu/~toshi/files/paper/Toshi_THEMIS_GBO_list_distribution.xls). We confirmed the presence of earthward flows which can be associated with north-south auroral streamers during the substorm growth phase. At around X = -12 Earth radii (Re), the northward magnetic field and its elevation angle decreased markedly approximately 4 min before substorm onset. A northward magnetic-field increase associated with pre-onset earthward flows was found at around X = -17Re. This variation indicates the occurrence of the local depolarization. Interestingly, in the region earthwards of X = -18Re, earthward flows in the central plasma sheet (CPS) reduced significantly about 3min before substorm onset. However, the earthward flows enhanced again at t = -60 sec in the region around X = -14 Re, and they moved toward the Earth. At t = 0, the dipolarization of the magnetic field started at X ~ -10 Re, and simultaneously the magnetic reconnection started at X ~ -20 Re. Synthesizing these results, we can confirm the validity of our catapult current sheet relaxation model.

  13. Geomagnetically induced currents in Uruguay: Sensitivity to modelling parameters

    Science.gov (United States)

    Caraballo, R.

    2016-11-01

    According to the traditional wisdom, geomagnetically induced currents (GIC) should occur rarely at mid-to-low latitudes, but in the last decades a growing number of reports have addressed their effects on high-voltage (HV) power grids at mid-to-low latitudes. The growing trend to interconnect national power grids to meet regional integration objectives, may lead to an increase in the size of the present energy transmission networks to form a sort of super-grid at continental scale. Such a broad and heterogeneous super-grid can be exposed to the effects of large GIC if appropriate mitigation actions are not taken into consideration. In the present study, we present GIC estimates for the Uruguayan HV power grid during severe magnetic storm conditions. The GIC intensities are strongly dependent on the rate of variation of the geomagnetic field, conductivity of the ground, power grid resistances and configuration. Calculated GIC are analysed as functions of these parameters. The results show a reasonable agreement with measured data in Brazil and Argentina, thus confirming the reliability of the model. The expansion of the grid leads to a strong increase in GIC intensities in almost all substations. The power grid response to changes in ground conductivity and resistances shows similar results in a minor extent. This leads us to consider GIC as a non-negligible phenomenon in South America. Consequently, GIC must be taken into account in mid-to-low latitude power grids as well.

  14. Comparison of two analytical models of blanking and proposal of a new model

    NARCIS (Netherlands)

    Klingenberg, W; Singh, UP

    With the development of accurate Finite Element models of the punching/blanking process by the present authors and other researchers, important possibilities emerged to model and analyse the process in a research environment. However, Finite Element models are less well suited for use in a

  15. Comparison of two analytical models of blanking and proposal of a new model

    NARCIS (Netherlands)

    Klingenberg, W; Singh, UP

    2005-01-01

    With the development of accurate Finite Element models of the punching/blanking process by the present authors and other researchers, important possibilities emerged to model and analyse the process in a research environment. However, Finite Element models are less well suited for use in a productio

  16. [Current indications for invasive prenatal diagnosis. New proposals based on the experience of Institute Nacional de Perinatología].

    Science.gov (United States)

    Fernández-Hernández, Liliana; Domínguez-Castro, Mauricio; Ibañez-Salvador, Juan Carlos; Grether-González, Patricia; Aguinaga-Ríos, Mónica

    2013-08-01

    Invasive prenatal diagnosis (IPD) allows identification of fetal diseases, mainly aneuploidy. With the addition of first-trimester prenatal screening and structural ultrasound, IPD indications have changed. To describe the current indications for IPD in pregnant patients at INPer. Descriptive and retrospective study. We reviewed medical records of patients in which IPD was performed during a period of 2.5 years. A total of 339 studies were performed: 81% by amniocentesis (AC), 13% by chorionic villus sampling (CVS) and 6% by cordocentesis or somatocentesis. The most common indications for AC were: advanced maternal age (AMA) (43%), fetuses with multiple defects by ultrasonido (23%) and presence of soft markers for aneuploidies (9%). For CVS were: cystic hygroma (24%). Increased nuchal translucency (NT) (24%), and AMA (18%). When the indication was only AMA, 1.5% of fetus presented aneuploidy. In women under 38 years and normal ultrasoud, chromosomal abnormalities were not detected. The increased NT in women 35 years it increased to 33%. We observed that the group who had normal translucencia nucal and AMA presented a low risk of chromosomal abnormalities. In the presence of an increased NT, 33% of fetuses were affected, so that measuring TN is considered the best non invasive PD tool. The average age with cytogenetic abnormalities was above 38 years, so we suggest to offer IPD in women above 38 years-old.

  17. District heating and cogeneration in the EU-28: Current situation, potential and proposed energy strategy for its generalisation

    Directory of Open Access Journals (Sweden)

    Enrique Rosales-Asensio

    2016-10-01

    Full Text Available Yearly, EU-28 conventional thermal generating plants reject a greater amount of energy than what ultimately is utilised by residential and commercial loads for heating and hot water. If this waste heat were to be used through district heating networks, given a previous energy valorisation, there would be a noticeable decrease in imported fossil fuels for heating. As a consequence, benefits in the form of an energy efficiency increase, an energy security improvement, and a minimisation of emitted greenhouse gases would occur. Given that it is not expected for heat demand to decrease significantly in the medium term, district heating networks show the greatest potential for the development of cogeneration. However, to make this happen, some barriers that are far from being technological but are mostly institutional and financial need to be removed. The purpose of this review is to provide information on the potential of using waste heat from conventional thermal power plants (subsequently converted into cogeneration plants in district heating networks located in the EU-28. For this, a preliminary assessment is conducted in order to show an estimate of the cost of adopting an energy strategy in which district heating networks are a major player of the energy mix. From this assessment, it is possible to see that even though the energy strategy proposed in this paper, which is based on a dramatic increase in the joint use of district heating networks and cogeneration, is capital-intensive and would require an annual investment of roughly 300 billion euros, its adoption would result in a reduction of yearly fuel expenses in the order of 100 billion euros and a shortening of about 15% of the total final energy consumption, which makes it of paramount interest as an enabler of the legal basis of the “Secure, Clean and Efficient Energy” future enacted by the EU-28 Horizon 2020.

  18. Modelling Monsoons: Understanding and Predicting Current and Future Behaviour

    Energy Technology Data Exchange (ETDEWEB)

    Turner, A; Sperber, K R; Slingo, J M; Meehl, G A; Mechoso, C R; Kimoto, M; Giannini, A

    2008-09-16

    including, but not limited to, the Mei-Yu/Baiu sudden onset and withdrawal, low-level jet orientation and variability, and orographic forced rainfall. Under anthropogenic climate change many competing factors complicate making robust projections of monsoon changes. Without aerosol effects, increased land-sea temperature contrast suggests strengthened monsoon circulation due to climate change. However, increased aerosol emissions will reflect more solar radiation back to space, which may temper or even reduce the strength of monsoon circulations compared to the present day. A more comprehensive assessment is needed of the impact of black carbon aerosols, which may modulate that of other anthropogenic greenhouse gases. Precipitation may behave independently from the circulation under warming conditions in which an increased atmospheric moisture loading, based purely on thermodynamic considerations, could result in increased monsoon rainfall under climate change. The challenge to improve model parameterizations and include more complex processes and feedbacks pushes computing resources to their limit, thus requiring continuous upgrades of computational infrastructure to ensure progress in understanding and predicting the current and future behavior of monsoons.

  19. Light-front model of the kaon electromagnetic current

    CERN Document Server

    Pacheco-Bicudo-Cabral de Melo, J; Frederico, T; Tomio, Lauro

    2003-01-01

    The electromagnetic form factor is extracted from both components of the electromagnetic current: J(plus) and J(minus) with a pseudo-scalar coupling of the quarks to the kaon. In the case of J(plus) there is no pair term contribution in the Drell-Yan frame. However, J(minus) component of the electromagnetic current the pair term contribution is different from zero and is necessary include it to preserve the rotational symmetry of the current.

  20. Discrete time domain modelling and analysis of dc-dc converters with continuous and discontinuous inductor current

    Science.gov (United States)

    Iwens, R. P.; Lee, F. C.; Triner, J. E.

    1977-01-01

    Using discrete time state variable representation, a generalized computer-aided modeling and analysis of dc-dc converters is presented. The methodology provides exact modeling and is applicable to all types of power stages and duty-cycle control, including continuous and discontinuous inductor current operation. Converter stability, transient behavior and audio susceptibility can be analytically evaluated and predicted. The generalized theory of the proposed approach to converter modeling and analysis is presented first, followed by a demonstrative example applying the theory to a constant frequency buck converter operating in continuous and discontinuous inductor current mode. Excellent agreement with laboratory test data has been observed.

  1. Discrete time domain modelling and analysis of dc-dc converters with continuous and discontinuous inductor current

    Science.gov (United States)

    Iwens, R. P.; Lee, F. C.; Triner, J. E.

    1977-01-01

    Using discrete time state variable representation, a generalized computer-aided modeling and analysis of dc-dc converters is presented. The methodology provides exact modeling and is applicable to all types of power stages and duty-cycle control, including continuous and discontinuous inductor current operation. Converter stability, transient behavior and audio susceptibility can be analytically evaluated and predicted. The generalized theory of the proposed approach to converter modeling and analysis is presented first, followed by a demonstrative example applying the theory to a constant frequency buck converter operating in continuous and discontinuous inductor current mode. Excellent agreement with laboratory test data has been observed.

  2. Results of the 2016 UT modeling benchmark proposed by the French Atomic Energy Commission (CEA) obtained with models implemented in CIVA software

    Science.gov (United States)

    Toullelan, Gwénaël; Chatillon, Sylvain; Raillon, Raphaële; Mahaut, Steve; Lonné, Sébastien; Bannouf, Souad

    2017-02-01

    For several years, the World Federation of NDE Centers, WFNDEC, proposes benchmark studies in which simulated results (in either ultrasonic, X-rays or eddy current NDT configurations) obtained with various models are compared to experiments. This year the proposed UT benchmark proposed by CEA concerns inspection configurations with multi-skips echoes i.e. the incident beam undergoes several skips on the surface and bottom of the specimen before interacting with the defect. This technique is commonly used to inspect thin specimen and/or in case of limited access inspection. This technique relies on the use of T45° mode in order to avoid mode conversion and to facilitate the interpretation of the echoes. The inspections were carried out with two probes of different aperture working at 5MHz.

  3. Gastric tubes and airway management in patients at risk of aspiration: history, current concepts, and proposal of an algorithm.

    Science.gov (United States)

    Salem, M Ramez; Khorasani, Arjang; Saatee, Siavosh; Crystal, George J; El-Orbany, Mohammad

    2014-03-01

    Rapid sequence induction and intubation (RSII) and awake tracheal intubation are commonly used anesthetic techniques in patients at risk of pulmonary aspiration of gastric or esophageal contents. Some of these patients may have a gastric tube (GT) placed preoperatively. Currently, there are no guidelines regarding which patient should have a GT placed before anesthetic induction. Furthermore, clinicians are not in agreement as to whether to keep a GT in situ, or to partially or completely withdraw it before anesthetic induction. In this review we provide a historical perspective of the use of GTs during anesthetic induction in patients at risk of pulmonary aspiration. Before the introduction of cricoid pressure (CP) in 1961, various techniques were used including RSII combined with a head-up tilt. Sellick initially recommended the withdrawal of the GT before anesthetic induction. He hypothesized that a GT increases the risk of regurgitation and interferes with the compression of the upper esophagus during CP. He later modified his view and emphasized the safety of CP in the presence of a GT. Despite subsequent studies supporting the effectiveness of CP in occluding the esophagus around a GT, Sellick's early view has been perpetuated by investigators who recommend partial or complete withdrawal of the GT. On the basis of available information, we have formulated an algorithm for airway management in patients at risk of aspiration of gastric or esophageal contents. The approach in an individual patient depends on: the procedure; type and severity of the underlying pathology; state of consciousness; likelihood of difficult airway; whether or not the GT is in place; contraindications to the use of RSII or CP. The algorithm calls for the preanesthetic use of a large-bore GT to remove undigested food particles and awake intubation in patients with achalasia, and emptying the pouch by external pressure and avoidance of a GT in patients with Zenker diverticulum. It also

  4. Modelling the electric field and the current density generated by cerebellar transcranial DC stimulation in humans.

    Science.gov (United States)

    Parazzini, Marta; Rossi, Elena; Ferrucci, Roberta; Liorni, Ilaria; Priori, Alberto; Ravazzani, Paolo

    2014-03-01

    Transcranial Direct Current Stimulation (tDCS) over the cerebellum (or cerebellar tDCS) modulates working memory, changes cerebello-brain interaction, and affects locomotion in humans. Also, the use of tDCS has been proposed for the treatment of disorders characterized by cerebellar dysfunction. Nonetheless, the electric field (E) and current density (J) spatial distributions generated by cerebellar tDCS are unknown. This work aimed to estimate E and J distributions during cerebellar tDCS. Computational electromagnetics techniques were applied in three human realistic models of different ages and gender. The stronger E and J occurred mainly in the cerebellar cortex, with some spread (up to 4%) toward the occipital cortex. Also, changes by ±1cm in the position of the active electrode resulted in a small effect (up to 4%) in the E and J spatial distribution in the cerebellum. Finally, the E and J spreads to the brainstem and the heart were negligible, thus further supporting the safety of this technique. Despite inter-individual differences, our modeling study confirms that the cerebellum is the structure mainly involved by cerebellar tDCS. Modeling approach reveals that during cerebellar tDCS the current spread to other structures outside the cerebellum is unlike to produce functional effects. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  5. Consumer’s trust in Internet shopping: a modelling proposal based on the standard learning hierarchy

    Directory of Open Access Journals (Sweden)

    MARIO PÉREZ RONCHEL

    2006-12-01

    Full Text Available This paper is placed on the framework of studies focused on analyzing the consumers’ buying behaviour on the Internet. We have based on adapting the hierarchy-of-effects model (standard learning hierarchy, in order to theoretically propose a conceptual model explaining how consumers’ beliefs —i.e. design, interaction speed, social benefits, and privacy— and attitudes toward the Internet as a communication medium can be plausible determinants of trusting in Internet shopping. Furthermore, our model poses that consumers’ overall opinions regarding with in-home shopping might also exert an influence on their evaluations about the Internet as a communication medium and, specially, as a shopping medium. The proposed conceptual model is supported by a deep and specific literature review. The relationships contained in the model have been estimated by means of structural equation modelling. Results confirm that this approach based on the cognitive information processing is valid to model consumers’ shopping behaviour on the Internet.Finally, several academic reflections, as well as a set of managerial implications based on the questions analyzed, are put forward..

  6. Proposal for initial collection efficiency models for direct granular upflow filtration

    Directory of Open Access Journals (Sweden)

    Alexandre Botari

    2015-05-01

    Full Text Available Mathematical models of the filtration process are based on the mass balance in the filter bed. Models of the filtration phenomenon describe the mass balance in bed filtration in terms of particle removal mechanisms, and allow for the determination of global particle removal efficiencies. This phenomenon is defined in terms of the geometry and the characteristic elements of granule collectors, particles and fluid, and the composition of the balance of forces that act in the particle collector system. This type of resolution is well known as the trajectory analysis theory. Particle trajectory analysis by mathematical correlation of the dimensionless numbers that represent fluid and particle characteristics is considered the main approach for mathematically modeling the initial collection efficiency of particle removal in water filtration. The existing initial collection efficiency models are designed for downflow filtration. This study analyzes initial collection efficiency models, and proposes an adaptation of these models to direct upflow filtration in a granular bed of coarse sand and gravel, taking into account the contribution of the gravitational factor of the settling removal efficiency in the proposal of initial collection efficiency models.

  7. Individualized model predicts brain current flow during transcranial direct-current stimulation treatment in responsive stroke patient.

    Science.gov (United States)

    Datta, Abhishek; Baker, Julie M; Bikson, Marom; Fridriksson, Julius

    2011-07-01

    Although numerous published reports have demonstrated the beneficial effects of transcranial direct-current stimulation (tDCS) on task performance, fundamental questions remain regarding the optimal electrode configuration on the scalp. Moreover, it is expected that lesioned brain tissue will influence current flow and should therefore be considered (and perhaps leveraged) in the design of individualized tDCS therapies for stroke. The current report demonstrates how different electrode configurations influence the flow of electrical current through brain tissue in a patient who responded positively to a tDCS treatment targeting aphasia. The patient, a 60-year-old man, sustained a left hemisphere ischemic stroke (lesion size = 87.42 mL) 64 months before his participation. In this study, we present results from the first high-resolution (1 mm(3)) model of tDCS in a brain with considerable stroke-related damage; the model was individualized for the patient who received anodal tDCS to his left frontal cortex with the reference cathode electrode placed on his right shoulder. We modeled the resulting brain current flow and also considered three additional reference electrode positions: right mastoid, right orbitofrontal cortex, and a "mirror" configuration with the anode over the undamaged right cortex. Our results demonstrate the profound effect of lesioned tissue on resulting current flow and the ability to modulate current pattern through the brain, including perilesional regions, through electrode montage design. The complexity of brain current flow modulation by detailed normal and pathologic anatomy suggest: (1) That computational models are critical for the rational interpretation and design of individualized tDCS stroke-therapy; and (2) These models must accurately reproduce head anatomy as shown here.

  8. A proposed Fast algorithm to construct the system matrices for a reduced-order groundwater model

    Science.gov (United States)

    Ushijima, Timothy T.; Yeh, William W.-G.

    2017-04-01

    Past research has demonstrated that a reduced-order model (ROM) can be two-to-three orders of magnitude smaller than the original model and run considerably faster with acceptable error. A standard method to construct the system matrices for a ROM is Proper Orthogonal Decomposition (POD), which projects the system matrices from the full model space onto a subspace whose range spans the full model space but has a much smaller dimension than the full model space. This projection can be prohibitively expensive to compute if it must be done repeatedly, as with a Monte Carlo simulation. We propose a Fast Algorithm to reduce the computational burden of constructing the system matrices for a parameterized, reduced-order groundwater model (i.e. one whose parameters are represented by zones or interpolation functions). The proposed algorithm decomposes the expensive system matrix projection into a set of simple scalar-matrix multiplications. This allows the algorithm to efficiently construct the system matrices of a POD reduced-order model at a significantly reduced computational cost compared with the standard projection-based method. The developed algorithm is applied to three test cases for demonstration purposes. The first test case is a small, two-dimensional, zoned-parameter, finite-difference model; the second test case is a small, two-dimensional, interpolated-parameter, finite-difference model; and the third test case is a realistically-scaled, two-dimensional, zoned-parameter, finite-element model. In each case, the algorithm is able to accurately and efficiently construct the system matrices of the reduced-order model.

  9. Marketing information systems in units of business information: a proposed model

    Directory of Open Access Journals (Sweden)

    Ana Maria Pereira

    2016-04-01

    Full Text Available Introduction: It proposes a theoretical model of marketing information system, which provides qualitiy attributes informations, such as: accuracy, economy, flexibility, reliability, relevance, simplicity and verifiability to the decision-makers of business organizations, based on the systemic vision and marketing theories. Objective: Present a model of marketing information system for business units, identifying the requirements, skills and abilities that the market demands of the librarian and his or hers integration. Methodology: Literature review that enabled the theoretic knowledge to propose the model. Results: The proposed model consists of five stages and constituent of subsystems that were not identified in existing marketing information systems, where it is confirmed that the organization of information is necessary for the development of the organization. Conclusions: It was identified that the librarian is an active agent, a mediator of information in marketing information systems in business units, must be present at all levels of the process and provide the administrators a greater credibility in the decisions taken.

  10. Technical support document for proposed revision of the model energy code thermal envelope requirements

    Energy Technology Data Exchange (ETDEWEB)

    Conner, C.C.; Lucas, R.G.

    1993-02-01

    This report documents the development of the proposed revision of the council of American Building Officials' (CABO) 1993 supplement to the 1992 Model Energy Code (MEC) (referred to as the 1993 MEC) building thermal envelope requirements for single-family and low-rise multifamily residences. The goal of this analysis was to develop revised guidelines based on an objective methodology that determined the most cost-effective (least total life-cycle cost [LCC]) combination of energy conservation measures (ECMs) for residences in different locations. The ECMs with the lowest LCC were used as a basis for proposing revised MEC maximum U[sub o]-value (thermal transmittance) curves in the MEC format. The changes proposed here affect the requirements for group R'' residences. The group R residences are detached one- and two-family dwellings (referred to as single-family) and all other residential buildings three stories or less (referred to as multifamily).

  11. Technical support document for proposed revision of the model energy code thermal envelope requirements

    Energy Technology Data Exchange (ETDEWEB)

    Conner, C.C.; Lucas, R.G.

    1993-02-01

    This report documents the development of the proposed revision of the council of American Building Officials` (CABO) 1993 supplement to the 1992 Model Energy Code (MEC) (referred to as the 1993 MEC) building thermal envelope requirements for single-family and low-rise multifamily residences. The goal of this analysis was to develop revised guidelines based on an objective methodology that determined the most cost-effective (least total life-cycle cost [LCC]) combination of energy conservation measures (ECMs) for residences in different locations. The ECMs with the lowest LCC were used as a basis for proposing revised MEC maximum U{sub o}-value (thermal transmittance) curves in the MEC format. The changes proposed here affect the requirements for ``group R`` residences. The group R residences are detached one- and two-family dwellings (referred to as single-family) and all other residential buildings three stories or less (referred to as multifamily).

  12. Effect of microscopic modeling of skin in electrical and thermal analysis of transcranial direct current stimulation

    Science.gov (United States)

    Gomez-Tames, Jose; Sugiyama, Yukiya; Laakso, Ilkka; Tanaka, Satoshi; Koyama, Soichiro; Sadato, Norihiro; Hirata, Akimasa

    2016-12-01

    Transcranial direct current stimulation (tDCS) is a neuromodulation scheme where a small current is delivered to the brain via two electrodes attached to the scalp. The electrode design is an important topic, not only as regards efficacy, but also from a safety perspective, as tDCS may be related to skin lesions that are sometimes observed after stimulation. Previous computational models of tDCS have omitted the effects of microscopic structures in the skin, and the different soak conditions of the electrodes, and model validation has been limited. In this study, multiphysics and multiscale analysis are proposed to demonstrate the importance of microscopic modeling of the skin, in order to clarify the effects of the internal electric field, and to examine temperature elevation around the electrodes. This novel microscopic model of the skin layer took into consideration the effect of saline/water penetration in hair follicles and sweat ducts on the field distribution around the electrodes. The temperature elevation in the skin was then computed by solving the bioheat equation. Also, a multiscale model was introduced to account for macroscopic and microscopic tissues of the head and skin, which was validated by measurement of the head resistance during tDCS. As a result, the electric field in the microscopic model of the skin was less localized when the follicles/ducts were filled with saline instead of hair or tap water. Temperature elevation was also lessened with saline, in comparison with other substances. Saline, which may penetrate the hair follicles and sweat ducts, suppressed the field concentration around the electrodes. For conventional magnitudes of current injection, and a head resistance of less than 10 kΩ, the temperature elevation in the skin when using saline-soaked electrodes was low, less than 0.1 °C, and unlikely to cause adverse thermal effects.

  13. Measuring the Quality of Travel Agencies E - Service Application: Proposed A Model

    Directory of Open Access Journals (Sweden)

    Ali Turan Bayram

    2015-09-01

    Full Text Available This study has been handled to a two dimensional e-service quality measurements, based on e-service quality measurement models in the literatüre, according to changing consumer demands. E-service quality models has been composed from two factors and seven sub-factors belong to these two factors, in mind to be associated with perceived quality on pre-puchase and post-purchase process. The aim of this study has been identified as developing a two dimensional model for travel agencies by putting out e- service quality dimensions. With the context of study questionnaire form was experimentedto 163 people and factor analysis was made with the aim of identifying sub-dimensions and in this factors. At the result of study, a model has been proposed a model for measuring the quality of travel agencies’ e-service application

  14. THE PROPOSED MODEL OF COLLABORATIVE VIRTUAL LEARNING ENVIRONMENT FOR INTRODUCTORY PROGRAMMING COURSE

    Directory of Open Access Journals (Sweden)

    Mahfudzah OTHMAN

    2012-01-01

    Full Text Available This paper discusses the proposed model of the collaborative virtual learning system for the introductory computer programming course which uses one of the collaborative learning techniques known as the “Think-Pair-Share”. The main objective of this study is to design a model for an online learning system that facilitates the collaborative learning activities in a virtual environment such as online communications and pair or small group discussions. In order to model the virtual learning environment, the RUP methodology has been used where it involves the data collection phase and the analysis and design phase. Fifty respondents have been randomly selected to participate in the data collection phase to investigate the students’ interest and learning styles as well as their learning preferences. The results have shown the needs for the development of online small group discussions that can be used as an alternative learning style for programming courses. The proposed design of the virtual learning system named as the Online Collaborative Learning System or OCLS is being depicted using the object-oriented models which are the use-case model and class diagram in order to show the concise processes of virtual “Think-Pair-Share” collaborative activities. The “Think-Pair-Share” collaborative learning technique that is being used in this model has been chosen because of its simplicity and relatively low-risk. This paper also presents the proposed model of the system’s architecture that will become the guidelines for the physical development of OCLS using the web-based applications.

  15. Efficient non-hydrostatic modelling of 3D wave-induced currents using a subgrid approach

    Science.gov (United States)

    Rijnsdorp, Dirk P.; Smit, Pieter B.; Zijlema, Marcel; Reniers, Ad J. H. M.

    2017-08-01

    Wave-induced currents are an ubiquitous feature in coastal waters that can spread material over the surf zone and the inner shelf. These currents are typically under resolved in non-hydrostatic wave-flow models due to computational constraints. Specifically, the low vertical resolutions adequate to describe the wave dynamics - and required to feasibly compute at the scales of a field site - are too coarse to account for the relevant details of the three-dimensional (3D) flow field. To describe the relevant dynamics of both wave and currents, while retaining a model framework that can be applied at field scales, we propose a two grid approach to solve the governing equations. With this approach, the vertical accelerations and non-hydrostatic pressures are resolved on a relatively coarse vertical grid (which is sufficient to accurately resolve the wave dynamics), whereas the horizontal velocities and turbulent stresses are resolved on a much finer subgrid (of which the resolution is dictated by the vertical scale of the mean flows). This approach ensures that the discrete pressure Poisson equation - the solution of which dominates the computational effort - is evaluated on the coarse grid scale, thereby greatly improving efficiency, while providing a fine vertical resolution to resolve the vertical variation of the mean flow. This work presents the general methodology, and discusses the numerical implementation in the SWASH wave-flow model. Model predictions are compared with observations of three flume experiments to demonstrate that the subgrid approach captures both the nearshore evolution of the waves, and the wave-induced flows like the undertow profile and longshore current. The accuracy of the subgrid predictions is comparable to fully resolved 3D simulations - but at much reduced computational costs. The findings of this work thereby demonstrate that the subgrid approach has the potential to make 3D non-hydrostatic simulations feasible at the scale of a

  16. Covariance of Light-Front Models Pair Current

    CERN Document Server

    Pacheco-Bicudo-Cabral de Melo, J; Naus, H W L; Sauer, P U

    1999-01-01

    We compute the "+" component of the electromagnetic current of a composite spin-one two-fermion system for vanishing momentum transfer component $q^+=q^0+q^3$. In particular, we extract the nonvanishing pair production amplitude on the light-front. It is a consequence of the longitudinal zero momentum mode, contributing to the light-front current in the Breit-frame. The covariance of the current is violated, if such pair terms are not included in its matrix elements. We illustrate our discussion with some numerical examples.

  17. The break of shielding current at pulsed field magnetization of a superconducting annulus (experiment and model simulation)

    Science.gov (United States)

    Korotkov, V. S.; Krasnoperov, E. P.; Kartamyshev, A. A.

    2017-09-01

    During the pulsed field magnetization of a high-T c annulus in liquid nitrogen the shielding current drops abruptly, providing rapid penetration of the magnetic flux into the hole of the superconductor. After the break of current the trapped field in the hole is small and negative although the body of the annulus remains highly magnetized. In the present work the current breaking effect is investigated both experimentally and numerically. The influence of the pulse parameter on the shielding current evolution during the break is researched. A simple model for the qualitative description of this process is proposed. The model shows the development of heating localized on the inhomogeneity of the high-temperature superconductor annulus providing the formation of a high resistive channel with temperature near to T c. The appearance of this hot channel leads to the rapid reduction of the shielding current and presents a new scenario of flux jump at high temperature.

  18. Modeling and Control of High-Voltage Direct-Current Transmission Systems: From Theory to Practice and Back

    OpenAIRE

    2014-01-01

    The problem of modeling and control of multi-terminal high-voltage direct-current transmission systems is addressed in this paper, which contains five main contributions. First, to propose a unified, physically motivated, modeling framework - based on port-Hamiltonian representations - of the various network topologies used in this application. Second, to prove that the system can be globally asymptotically stabilized with a decentralized PI control, that exploits its passivity properties. Cl...

  19. Revised model of thermally stimulated current in MOS capacitors

    Energy Technology Data Exchange (ETDEWEB)

    Fleetwood, D.M.

    1997-06-01

    It is shown analytically and experimentally that thermally stimulated current (TSC) measurements at negative bias incompletely describe oxide-trap charge in SIMOX and bipolar base oxides irradiated at 0 V. Positive-bias TSC is also required.

  20. A proposed theoretical model to explain relative age effects in sport.

    Science.gov (United States)

    Hancock, David J; Adler, Ashley L; Côté, Jean

    2013-01-01

    Exemplary scientific methods describe concepts and provide theories for further testing. For the field of relative age effects (RAEs) in sport, the scientific method appears to be limited to description. The purpose of this paper is to provide a theoretical model to explain RAEs in sport, which researchers can use to test the effects, as well as to generate new hypotheses and recommendations. Herein, we argue that social agents have the largest influence on RAEs. Specifically, we propose that parents influence RAEs through Matthew effects, coaches influence RAEs through Pygmalion effects and athletes influence RAEs through Galatea effects. Integrating these three theories, we propose a model that explains RAEs through these various social agents. This paper provides a theoretical foundation from which researchers can further understand, explain and eventually use to create policies aimed at limiting the negative effect of relative age in sport.

  1. Analytical Modeling Of The Steinmetz Coefficient For Single-Phase Transformer Eddy Current Loss Prediction

    Directory of Open Access Journals (Sweden)

    T. Aly Saandy

    2015-08-01

    Full Text Available Abstract This article presents to an analytical calculation methodology of the Steinmetz coefficient applied to the prediction of Eddy current loss in a single-phase transformer. Based on the electrical circuit theory the active power consumed by the core is expressed analytically in function of the electrical parameters as resistivity and the geometrical dimensions of the core. The proposed modeling approach is established with the duality parallel series. The required coefficient is identified from the empirical Steinmetz data based on the experimented active power expression. To verify the relevance of the model validations both by simulations with two in two different frequencies and measurements were carried out. The obtained results are in good agreement with the theoretical approach and the practical results.

  2. The Model Proposal Which Aims to build up a Balanced Scorecard in Thermal Tourism Businesses

    OpenAIRE

    GENÇAY, İ. Cemal

    2014-01-01

    According to the Balanced Scorecard named as “corporate performance scorecard”, corporate performance, finance, customer, internal processes, learning and development must be evaluated with dimensions. Balanced Scorecard proposes that businesses are supposed to be managed with a strategic management system mainly based on measurement and evaluation. This study aims to present the model objectives, criteria and the process that guides about how to build up the corporate performance (Bala...

  3. Sustainable Agroforestry Models for Proposed Food Production in Post-Mined Land Sites of South Sumatera

    Directory of Open Access Journals (Sweden)

    Bandi Hermawan

    2016-04-01

    Full Text Available The reclamation areas of the opencast coal mining in South Sumatera are predominantly compact and nutrient-poor, marginal sites, but have a high potential for cultivation of fast-growing trees and agricultural crops.  This paper aims to promote several models of agroforestry in the post-mined land in South Sumatera as a new strategy in reclaiming degraded soil properties for both enviroment and economic purposes.  About 5,000 ha of coal mining areas were observed to characterize the landscape and soil properties in the area, then overlaid with the landuse maps of post-mining plans issued by the company.  Results showed that about 1,730 ha of the reclamation areas was suitable for agroforestry while the rest was for utilities, camping ground, water pond and grassland.  Three models were proposed for the agroforestry areas, including (i agrisilviculture model (1,190 ha, (ii silvihorticulture model (203 ha, and (iii local-species collection model for agrihortisilviculture (337 ha.  Prior to the agroforestry establishment, all reclamation sites were subjected to the revegetation with fast-growing trees and other rejuvenation treatments in order to restore favour soil and microclimate conditions.  The proposed components for each model were as follows: for agrisilviculture model were cultivation on the alley cropping system of trees and food crops, for silvihorticulture model were the plantation of fruit trees in the bench of water pond, and for local-species collection model for agrihortisilviculture were the cultivation of local forest and food crop species.

  4. Enhancing Information Systems Security in Educational Organizations in KSA through proposing security model

    Directory of Open Access Journals (Sweden)

    Hussain A.H. Awad

    2011-09-01

    Full Text Available It is well known that technology utilization is not restricted for one sector than the other anymore, Educational organizations share many parts of their information systems with commercial organizations. In this paper we will try to identify the main characteristics of information systems in educational organizations, then we will propose a model of two parts to enhance the information systems security, the first part of the model will handle the policy and laws of the information system, the second part will provide a technical approach on how to audit and subsequently maintain the security of information system.

  5. Cognitive-Existential Family Therapy: A Proposed Theoretical Integration Model for Pastoral Counselors.

    Science.gov (United States)

    Saunders, James A

    2015-03-01

    Fundamental Christianity and psychology are frequently viewed as incompatible pursuits. However, proponents of the integrationist movement posit that pastoral counselors can utilize principles from psychology if they adopt the premise that all truth is God's truth. Assuming this perspective, Cognitive-Existential Family Therapy (CEFT) - a theoretical integration model compatible with Christian fundamentalism - is proposed. The philosophical assumptions and models of personality, health, and abnormality are explored. Additionally, the article provides an overview of the therapeutic process. © The Author(s) 2015 Reprints and permissions:sagepub.co.uk/journalsPermissions.nav.

  6. The proposal and realization on more exact modeling of COIL performance

    Institute of Scientific and Technical Information of China (English)

    Shouxian; Li; Xiaojian; Shu; Yanyi; Du; Hua; Su; Yan; Li; Zhen; Yu

    2013-01-01

    The chemical oxygen–iodine laser(COIL)is the shortest-wavelength high-power chemical laser that has been demonstrated.The characteristics,such as good atmospheric propagation,short wavelength and excellent transmission through optical fibers,make the COIL a good candidate for high-power laser application.To model the complete COIL lasing interaction,a three-dimensional formulation of the fluid dynamics,species continuity and radiation transport equations is necessary.The computational effort to calculate the flow field over the entire nozzle bank with a grid fine enough to resolve the injection holes is so large as to preclude doing the calculation.The approach to modeling chemical lasers then has been to reduce the complexity of the model to correspond to the available computational capability,adding details as computing power increased.The modeling of lasing in the COIL medium is proposed,which is coupling with the effects induced by transverse injection of secondary gases,non-equilibrium chemical reactions,nozzle tail flow and boundary layer.The coupled steady solutions of the fluid dynamics and optics in a COIL complex three-dimensional cavity flow field are obtained following the proposal.The modeling results show that these effects have some influence on the lasing properties.A feasible methodology and a theoretical tool are offered to predict the beam quality for large-scale COIL devices.

  7. Land use change modelling: current practice and research priorities

    NARCIS (Netherlands)

    Verburg, P.H.; Schot, P.; Dijst, M.J.; Veldkamp, A.

    2004-01-01

    Land use change models are tools to support the analysis of the causes and consequences of land use dynamics. Scenario analysis with land use models can support land use planning and policy. Numerous land use models are available, developed from different disciplinary backgrounds. This paper reviews

  8. Energetic models: a proposal of integrated planning; Modelos energeticos: uma proposta de planejamento integrado

    Energy Technology Data Exchange (ETDEWEB)

    Pereira Junior, Amaro Olimpio; Soares, Jeferson Borghetti; Araujo, Mauro Almeida [Empresa de Pesquisa Energetica (EPE), Brasilia, DF (Brazil)]. E-mails: amaro.pereira@epe.gov.br; jeferson.soares@epe.gov.br; mauro.almeida@epe.gov.br; La Rovere, Emilio Lebre [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-Graduacao de Engenharia. Programa de Planejamento Estrategico]. E-mail: emilio@ppe.ufrj.br; Costa, Ricardo Cunha da [Banco Nacional de Desenvolvimento Economico e Social (BNDES), Rio de Janeiro, RJ (Brazil)]. E-mail: rcco@bndes.gov.br

    2006-07-01

    Top-down, bottom-up and hybrid models for representing energy system are often used in energy planning. However, in developing countries some of their assumptions do not apply: markets are not developed and not competitive; informal economies are representative; there are huge social inequalities; regulatory changes are not completed; there exist constraints to capital flow; etc. All theses problems need to be well represented in order to have energy analysis more consistent. In this work, it is proposed a multi-sector dynamic recursive model that incorporates consumer behaviors, energy policies, technical progress and factors of production substitution. The static result feeds detailed energy models that provide updated values for the next step equilibrium. This approach takes advantages not only in terms of computation but also in terms of the consistence between economy and energy modeling. (author)

  9. Carbonado: Physical and chemical properties, a critical evaluation of proposed origins, and a revised genetic model

    Science.gov (United States)

    Haggerty, Stephen E.

    2014-03-01

    Carbonado-diamond is the most controversial of all diamond types and is found only in Brazil, and the Central African Republic (Bangui). Neither an affinity to Earth's mantle, nor an origin in the crust can be unequivocally established. Carbonado-diamond is at least 3.8 Ga old, an age about 0.5 Ga older than the oldest diamonds yet reported in kimberlites and lamproites on Earth. Derived from Neo- to Mid-Proterozoic meta-conglomerates, the primary magmatic host rock has not been identified. Discovered in 1841, the material is polycrystalline, robust and coke-like, and is best described as a strongly bonded micro-diamond ceramic. It is characteristically porous, which precludes an origin at high pressures and high temperatures in Earth's deep interior, yet it is also typically patinated, with a glass-like surface that resembles melting. With exotic inclusions of highly reduced metals, carbides, and nitrides the origin of carbonado-diamond is made even more challenging. But the challenge is important because a new diamondiferous host rock may be involved, and the development of a new physical process for generating diamond is possibly assured. The combination of micro-crystals and random crystal orientation leads to extreme mechanical toughness, and a predicable super-hardness. The physical and chemical properties of carbonado are described with a view to the development of a mimetic strategy to synthesize carbonado and to duplicate its extreme toughness and super-hardness. Textural variations are described with an emphasis on melt-like surface features, not previously discussed in the literature, but having a very clear bearing on the history and genesis of carbonado. Selected physical properties are presented and the proposed origins, diverse in character and imaginatively novel, are critically reviewed. From our present knowledge of the dynamic Earth, all indications are that carbonado is unlikely to be of terrestrial origin. A revised model for the origin of

  10. Survey of current situation in radiation belt modeling

    Science.gov (United States)

    Fung, Shing F.

    2004-01-01

    The study of Earth's radiation belts is one of the oldest subjects in space physics. Despite the tremendous progress made in the last four decades, we still lack a complete understanding of the radiation belts in terms of their configurations, dynamics, and detailed physical accounts of their sources and sinks. The static nature of early empirical trapped radiation models, for examples, the NASA AP-8 and AE-8 models, renders those models inappropriate for predicting short-term radiation belt behaviors associated with geomagnetic storms and substorms. Due to incomplete data coverage, these models are also inaccurate at low altitudes (e.g., radiation data from modern space missions and advancement in physical modeling and data management techniques have now allowed the development of new empirical and physical radiation belt models. In this paper, we will review the status of modern radiation belt modeling. Published by Elsevier Ltd on behalf of COSPAR.

  11. Modeling Current Transfer from PV Modules Based on Meteorological Data

    Energy Technology Data Exchange (ETDEWEB)

    Hacke, Peter; Smith, Ryan; Kurtz, Sarah; Jordan, Dirk; Wohlgemuth, John

    2016-11-21

    Current transferred from the active cell circuit to ground in modules undergoing potential-induced degradation (PID) stress is analyzed with respect to meteorological data. Duration and coulombs transferred as a function of whether the module is wet (from dew or rain) or the extent of uncondensed surface humidity are quantified based on meteorological indicators. With this, functions predicting the mode and rate of coulomb transfer are developed for use in estimating the relative PID stress associated with temperature, moisture, and system voltage in any climate. Current transfer in a framed crystalline silicon module is relatively high when there is no condensed water on the module, whereas current transfer in a thin-film module held by edge clips is not, and displays a greater fraction of coulombs transferred when wet compared to the framed module in the natural environment.

  12. Mitigation of turbidity currents in reservoirs with passive retention systems: validation of CFD modeling

    Science.gov (United States)

    Ferreira, E.; Alves, E.; Ferreira, R. M. L.

    2012-04-01

    Sediment deposition by continuous turbidity currents may affect eco-environmental river dynamics in natural reservoirs and hinder the maneuverability of bottom discharge gates in dam reservoirs. In recent years, innovative techniques have been proposed to enforce the deposition of turbidity further upstream in the reservoir (and away from the dam), namely, the use of solid and permeable obstacles such as water jet screens , geotextile screens, etc.. The main objective of this study is to validate a computational fluid dynamics (CFD) code applied to the simulation of the interaction between a turbidity current and a passive retention system, designed to induce sediment deposition. To accomplish the proposed objective, laboratory tests were conducted where a simple obstacle configuration was subjected to the passage of currents with different initial sediment concentrations. The experimental data was used to build benchmark cases to validate the 3D CFD software ANSYS-CFX. Sensitivity tests of mesh design, turbulence models and discretization requirements were performed. The validation consisted in comparing experimental and numerical results, involving instantaneous and time-averaged sediment concentrations and velocities. In general, a good agreement between the numerical and the experimental values is achieved when: i) realistic outlet conditions are specified, ii) channel roughness is properly calibrated, iii) two equation k - ɛ models are employed iv) a fine mesh is employed near the bottom boundary. Acknowledgements This study was funded by the Portuguese Foundation for Science and Technology through the project PTDC/ECM/099485/2008. The first author thanks the assistance of Professor Moitinho de Almeida from ICIST and to all members of the project and of the Fluvial Hydraulics group of CEHIDRO.

  13. Erosion Control of Scour during Construction. Report 7. Current--A Wave-Induced Current Model.

    Science.gov (United States)

    1984-09-01

    a part of the Ash Wednesday storm of March 1962 was simulated. The numerical results obtained for this case appeared to be reasonable , and the...case, the model yields results that appear to be reasonable . 34 _ _ ~ ~ . . -,.-.-- - ~ n r~ - -r r ~ rn- ~ - .--.--- n- ---- n---. -.- o-" - PART V...4 4 4 4A 44 4 4 4 8 . 4 4 J A 4) 0 AA.. * ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 00 A. N 4VPW))440 444444Nii1))iiIIii)1))))i I& . ’a AWIbIAIA lb ’ CIDP ’a44V

  14. System analysis with improved thermo-mechanical fuel rod models for modeling current and advanced LWR materials in accident scenarios

    Science.gov (United States)

    Porter, Ian Edward

    A nuclear reactor systems code has the ability to model the system response in an accident scenario based on known initial conditions at the onset of the transient. However, there has been a tendency for these codes to lack the detailed thermo-mechanical fuel rod response models needed for accurate prediction of fuel rod failure. This proposed work will couple today's most widely used steady-state (FRAPCON) and transient (FRAPTRAN) fuel rod models with a systems code TRACE for best-estimate modeling of system response in accident scenarios such as a loss of coolant accident (LOCA). In doing so, code modifications will be made to model gamma heating in LWRs during steady-state and accident conditions and to improve fuel rod thermal/mechanical analysis by allowing axial nodalization of burnup-dependent phenomena such as swelling, cladding creep and oxidation. With the ability to model both burnup-dependent parameters and transient fuel rod response, a fuel dispersal study will be conducted using a hypothetical accident scenario under both PWR and BWR conditions to determine the amount of fuel dispersed under varying conditions. Due to the fuel fragmentation size and internal rod pressure both being dependent on burnup, this analysis will be conducted at beginning, middle and end of cycle to examine the effects that cycle time can play on fuel rod failure and dispersal. Current fuel rod and system codes used by the Nuclear Regulatory Commission (NRC) are compilations of legacy codes with only commonly used light water reactor materials, Uranium Dioxide (UO2), Mixed Oxide (U/PuO 2) and zirconium alloys. However, the events at Fukushima Daiichi and Three Mile Island accident have shown the need for exploration into advanced materials possessing improved accident tolerance. This work looks to further modify the NRC codes to include silicon carbide (SiC), an advanced cladding material proposed by current DOE funded research on accident tolerant fuels (ATF). Several

  15. Phenomenological Models of Holographic Superconductors and Hall currents

    CERN Document Server

    Aprile, Francesco; Rodriguez-Gomez, Diego; Russo, Jorge G

    2010-01-01

    We study general models of holographic superconductivity parametrized by four arbitrary functions of a neutral scalar field of the bulk theory. The models can accommodate several features of real superconductors, like arbitrary critical temperatures and critical exponents in a certain range, and perhaps impurities, boundary or thickness effects. We find analytical expressions for the critical exponents of the general model and show that they satisfy the Rushbrooke identity. An important subclass of models exhibits second order phase transitions. A study of the specific heat shows that general models can also describe holographic superconductors undergoing first, second and third (or higher) order phase transitions. We discuss how small deformations of the HHH model lead to the appearance of resonance peaks in the conductivity, which become narrower as the temperature is gradually decreased, without the need for tuning mass of the scalar to be close to the Breitenlohner-Freedman bound. Finally, we investigate ...

  16. Model of vertical plasma motion during the current quench

    Science.gov (United States)

    Kiramov, D. I.; Breizman, B. N.

    2017-10-01

    Tokamak disruptions impair plasma position control, which allows the plasma column to move and hit the wall. These detrimental events enhance thermal and mechanical loads due to halo currents and runaway electron losses. Their fundamental understanding and prevention is one of the high-priority items for ITER.

  17. Covariance of light-front models: pair current

    NARCIS (Netherlands)

    Melo, J.P.B.C. de; Frederico, T.; Naus, H.W.L.; Sauer, P.U.

    1999-01-01

    We compute the + component, i.e., j+ = j0 + j3, of the electromagnetic current of a composite spin-one two-fermion system for vanishing momentum transfer component q+ = q0 + q3. In particular, we extract the nonvanishing pair production amplitude on the light-front. It is a consequence of the longit

  18. Hybrid Models of Alternative Current Filter for Hvdc

    Directory of Open Access Journals (Sweden)

    Ufa Ruslan A.

    2017-01-01

    Full Text Available Based on a hybrid simulation concept of HVDC, the developed hybrid AC filter models, providing the sufficiently full and adequate modeling of all single continuous spectrum of quasi-steady-state and transient processes in the filter, are presented. The obtained results suggest that usage of the hybrid simulation approach is carried out a methodically accurate with guaranteed instrumental error solution of differential equation systems of mathematical models of HVDC.

  19. Building ambidextrous organizations through intellectual capital: a proposal for a multilevel model

    Directory of Open Access Journals (Sweden)

    Susana Fernández-Pérez de la Lastra

    2017-08-01

    Full Text Available Purpose: This paper proposes an alternative theoretical model to describe, from a multilevel perspective, the way in which ambidexterity is built across different organizational levels, through specific combinations of the facets of intellectual capital—human, social and organizational capital. Design/methodology/approach: In this study, main arguments from intellectual capital, strategic human resource management (SHRM and multilevel literature are integrated. The intellectual capital literature provides our model with the input (human capital, mechanisms (social capital and the infrastructure (organizational capital required to create ambidextrous capabilities; the multilevel perspective reveals the context in which ambidexterity is reached, and the strategic human resource management literature provides the model with the specific mechanisms (policies and practices and conditions required by ambidexterity (HRM flexibility and horizontal fit. Findings: Although the literature widely recognizes ambidexterity as a potential source of sustainable competitive advantage, the processes by which organizations complement exploration and exploitation activities still remain unclear. This study sheds some light on the analysis of these complex dynamics, explaining how ambidextrous capabilities can arise from different alternative combinations of human, social and organizational capital. Originality/value: The paper expands the extant literature in the field, describing different paths to achieving organizational ambidexterity. The configurational approach adopted adds value to the proposed model, as it helps to explaining alternative synergistic mixes of ambidextrous intellectual capital at different organizational levels.

  20. Thermal Dissipation Modelling and Design of ITER PF Converter Alternating Current Busbar

    Science.gov (United States)

    Guo, Bin; Song, Zhiquan; Fu, Peng; Jiang, Li; Li, Jinchao; Wang, Min; Dong, Lin

    2016-10-01

    Because the larger metallic surrounds are heated by the eddy current, which is generated by the AC current flowing through the AC busbar in the International Thermonuclear Experimental Reactor (ITER) poloidal field (PF) converter system, shielding of the AC busbar is required to decrease the temperature rise of the surrounds to satisfy the design requirement. Three special types of AC busbar with natural cooling, air cooling and water cooling busbar structure have been proposed and investigated in this paper. For each cooling scheme, a 3D finite model based on the proposed structure has been developed to perform the electromagnetic and thermal analysis to predict their operation behavior. Comparing the analysis results of the three different cooling patterns, water cooling has more advantages than the other patterns and it is selected to be the thermal dissipation pattern for the AC busbar of ITER PF converter unit. The approach to qualify the suitable cooling scheme in this paper can be provided as a reference on the thermal dissipation design of AC busbar in the converter system. supported by National Natural Science Foundation of China (No. 51407179)

  1. The NRC's SPAR Models: Current Status, Future Development, and Modeling Issues

    Energy Technology Data Exchange (ETDEWEB)

    Robert F. Buell

    2008-09-01

    Probabilistic risk assessments (PRAs) play an increasingly important role in the regulatory framework of the U.S. nuclear power industry. The Nuclear Regulatory Commission (NRC) relies on a set of plant-specific Standardized Plant Analysis Risk (SPAR) models to provide critical risk-based input to the regulatory process. The Significance Determination Process (SDP), Management Directive 8.3 - NRC Incident Investigation Program, Accident Sequence Precursor (ASP) and Mitigating Systems Performance Index (MSPI) programs are among the regulatory initiatives that receive significant input from the SPAR models. Other uses of the SPAR models include: Screening & Resolution of Generic Safety Issues, License Amendment reviews and Notice of Enforcement Discretion (NOEDs). This paper presents the current status of SPAR model development activities, future development objectives, and issues related to the development, verification and maintenance of the SPAR models.

  2. Analytical modeling of drain current and RF performance for double-gate fully depleted nanoscale SOI MOSFETs

    Institute of Scientific and Technical Information of China (English)

    Rajiv Sharma; Sujata Pandey; Shail Bala Jain

    2012-01-01

    A new 2D analytical drain current model is presented for symmetric double-gate fully depleted nanoscale SOI MOSFETs.Investigation of device parameters like transconductance for double-gate fully depleted nanoscale SOI MOSFETs is also carried out.Finally this work is concluded by modeling the cut-off frequency,which is one of the main figures of merit for analog/RF performance for double-gate fully depleted nanoscale SOI MOSFETs.The results of the modeling are compared with those obtained by a 2D ATLAS device simulator to verify the accuracy of the proposed model.

  3. Proposed model structures for Upper Freeport and Lewiston-Stockton vitrinites

    Energy Technology Data Exchange (ETDEWEB)

    Mathews, J.P.; Hatcher, P.G.; Scaroni, A.W. [Pennsylvania State University, University Park, PA (USA). Energy Institute and the Department of Energy and GeoEnvironmental Engineering

    2001-08-01

    Molecular models of vitrinite (obtained from obvious tree remains) from the Upper Freeport and Lewiston-Stockton coal seams are presented. Utilizing pure telocollinite reduced the complexity of the model and resulted in more realistic molecular structures than from whole coal analyses. The structures presented are in agreement with experimentally determined bulk chemical parameters. These were easily achieved with current software and computational expense. However, it was more difficult to produce model structures which have calculated physical parameters (of the global minimum structure determined from molecular mechanics and dynamics) in agreement with experimentally determined parameters. For these bituminous vitrinites, the addition of physical parameters severely constrained the type of model structures that could be produced. The molecular structures presented are covalently linked aromatic and hydroaromatic structures with a distribution of cross-link densities. Despite being very close in maturation (as determined from vitrinite reflectance) the structural differences have a significant impact on behavior. The current models are not yet consistent with some behavioral aspects such as solvent swelling. It is suggested that a greater molecular scale is needed before multiple facets of coals behavior can be explained. 60 refs., 7 figs., 3 tabs.

  4. Emerging identities: A proposed model for an interactive science curriculum for First Nations students

    Science.gov (United States)

    Sable, Trudy

    Mi'kmaw students face a complexity of personal, cultural, and social conditions within contemporary educational systems that affect their continued participation in the educational process offered within Atlantic Canada. Despite a variety of approaches developed by educators to address the high drop out rate and lack of interest in science, the statistics remain largely unchanged. Aboriginal educators are calling for a "new story" in education that better meets the needs of Aboriginal students. This study attempts to identify the conditions and contexts necessary to bridge the gap that currently exists for Aboriginal students in science studies. The research investigates the basic relationship between learning in general and the meaning-making processes engaged in by students of a Grade 7/8 class within a Mi'kmaw reserve school. It leads to a proposal for an alternative pedagogy, or a new narrative, for teaching science to Aboriginal students and the foundations for a culturally interactive science curriculum. For educators to understand the complexity of issues affecting Mi'kmaw student achievement in science requires a theoretical framework that allows the students' lived experience to emerge. Toward this end, the research includes both phenomenological and ethnographic approaches to understanding the lived experiences and cultural narratives based on interviews with the students, a field trip within the community, and a trial chemistry lesson. I examined how these students perceive themselves in different contexts and how their sense of identity establishes the meaningfulness of particular educational content. I also assessed how person, community/cultural and social contexts affect the students' learning. Part of creating this new narrative requires recognizing knowledge, including science, as a cultural product Taking this cultural view of scientific knowledge allows us to view learning as a process of identity formation and culture as a system of symbols

  5. Conceptual model of iCAL4LA: Proposing the components using comparative analysis

    Science.gov (United States)

    Ahmad, Siti Zulaiha; Mutalib, Ariffin Abdul

    2016-08-01

    This paper discusses an on-going study that initiates an initial process in determining the common components for a conceptual model of interactive computer-assisted learning that is specifically designed for low achieving children. This group of children needs a specific learning support that can be used as an alternative learning material in their learning environment. In order to develop the conceptual model, this study extracts the common components from 15 strongly justified computer assisted learning studies. A comparative analysis has been conducted to determine the most appropriate components by using a set of specific indication classification to prioritize the applicability. The results of the extraction process reveal 17 common components for consideration. Later, based on scientific justifications, 16 of them were selected as the proposed components for the model.

  6. Optimizing full scope of practice for nurse practitioners in primary care: A proposed conceptual model.

    Science.gov (United States)

    Poghosyan, Lusine; Boyd, Donald R; Clarke, Sean P

    2016-01-01

    Nurse practitioners (NPs), if utilized to their optimal potential, could play a key role in meeting the growing demand for primary care. The purpose of this study was to propose a comprehensive model for maximizing NP contributions to primary care which includes the factors affecting NP care and patient outcomes and explains their interrelated impact. We synthesized the results of the published literature to develop a model, which emphasizes NP scope of practice regulations, institutional policies, NP practice environment, and NP workforce outcomes as determinants of NP care and patient outcomes. Our model provides a framework to help explain how variations in scope of practice regulations at the state-level and institutional policies within organizations directly and indirectly influence the practice environment of NPs, NP workforce outcomes, and patient care and outcomes. Aligning policy change, organizational innovations, and future research are critical to NP optimal utilization and patient care and outcomes. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. The Proposed Blended-MDA for Software Modeling in Architecture Phase

    Directory of Open Access Journals (Sweden)

    Sidra Sultana

    2016-08-01

    Full Text Available The Model Driven Architecture is the modeling approach that ensures the re-usability, portability and inter-operability of the software. For the structuring of the system it provides basic guidelines to be modeled. Separating the architecture from the design is one of the main aim of MDA. Functional requirements of the system are being analyzed by the detailed design of the system (for instance, use cases and for non-functional requirements, the infrastructure is provided by the architecture of the software ensuring performance, reliability, scalability etc. In this research paper, some case studies are extensively analyzed in the domain of web applications. Functional and non-functional aspects are analyzed in the comparative analysis table. Finally, the Blended-MDA Framework is proposed for the case study entitled as Online Event Manager.

  8. A Proposed Analytical Model for Integrated Pick-and-Sort Systems

    Directory of Open Access Journals (Sweden)

    Recep KIZILASLAN

    2013-11-01

    Full Text Available In this study we present an analytical approach for integration of order picking and sortation operations which are the most important, labour intensive and costly activity for warehouses. Main aim is to investigate order picking and sorting efficiencies under different design issues as a function of order wave size. Integrated analytical model is proposed to estimate the optimum order picking and order sortation efficiency. The model, which has been tested by simulations with different illustrative examples, calculates the optimum wave size that solves the trade-off between picking and sorting operations and makes the order picking and sortations efficiency maximum. Our model also allow system designer to predict the order picking and sorting capacity for different system configurations. This study presents an innovative approach for integrated warehouse operations.

  9. Model of Current Threshold for Perception in Testing Electrical Safety Performance

    Institute of Scientific and Technical Information of China (English)

    王晓飞; 张朝晖; 李东; 刘国忠; 赵旭

    2010-01-01

    A generalized mathematical model of human body current threshold for perception was established and the current flowing through human body could be arbitrary cyclical waveforms.The relationship between human body current threshold for perception and current frequency, true root mean square(RMS) value and influence factor was described.A test system was established based on electroencephalogram(EEG) to study the relationship between human body current threshold for perception and current waveform, frequency ...

  10. Dynamic modelling and robust current control of wind-turbine driven DFIG during external AC voltage dip

    Institute of Scientific and Technical Information of China (English)

    HU Jia-bing; HE Yi-kang

    2006-01-01

    Doubly-FedInduction Generator (DFIG), with vector control applied, is widely used in Variable-Speed ConstantFrequency (VSCF) windenergy generation system and shows good performance in maximum wind energy capture. But in two traditional vector control schemes, the equivalent stator magnetizing current is considered invariant in order to simplify the rotor current inner-loop controller. The two schemes can perform very well when the grid is in normal condition. However, when grid disturbance such as grid voltage dip or swell fault occurs, the control performance worsens, the rotor over current occurs and the Fault Ride-Through (FRT) capability of the DFIG wind energy generation system gets seriously deteriorated. An accurate DFIG model was used to deeply investigate the deficiency of the traditional vector control. The improved control schemes of two typical traditional vector control schemes used in DFIG were proposed, and simulation study of the proposed and traditional control schemes, with robust rotor current control using Internal Model Control (IMC) method, was carried out. The validity of the proposed modified schemes to control the rotor current and to improve the FRT capability of the DFIG wind energy generation system was proved by the comparison study.

  11. Organizational intellectual capital and the role of the nurse manager: A proposed conceptual model.

    Science.gov (United States)

    Gilbert, Jason H; Von Ah, Diane; Broome, Marion E

    2017-04-19

    Nurse managers must leverage both the human capital and social capital of the teams they lead in order to produce quality outcomes. Little is known about the relationship between human capital and social capital and how these concepts may work together to produce organizational outcomes through leadership of nurses. The purpose of this article was to explore the concepts of human capital and social capital as they relate to nursing leadership in health care organizations. Specific aims included (a) to synthesize the literature related to human capital and social capital in leadership, (b) to refine the conceptual definitions of human capital and social capital with associated conceptual antecedents and consequences, and (c) to propose a synthesized conceptual model guiding further empirical research of social capital and human capital in nursing leadership. A systematic integrative review of leadership literature using criteria informed by Whittemore and Knafl (2005) was completed. CINAHL Plus with Full Text, Academic Search Premier, Business Source Premier, Health Business FullTEXT, MEDLINE, and PsychINFO databases were searched for the years 1995 to 2016 using terms "human capital," "social capital," and "management." Analysis of conceptual definitions, theoretical and conceptual models, antecedents and consequences, propositions or hypotheses, and empirical support for 37 articles fitting review criteria resulted in the synthesis of the proposed Gilbert Conceptual Model of Organizational Intellectual Capital. The Gilbert Conceptual Model of Organizational Intellectual Capital advances the propositions of human capital theory and social capital theory and is the first model to conceptualize the direct and moderating effects that nurse leaders have on the human capital and social capital of the teams they lead. This model provides a framework for further empirical study and may have implications for practice, organizational policy, and education related to nursing

  12. Data Assimilation and Model Simulations in the California Current

    Science.gov (United States)

    2016-06-07

    regions in order to improve our scientific understanding of the structure and dynamics of such regions. OBJECTIVES The broad objective of this research...analysis, and to apply the method to several quasi-synoptic hydrographic data sets from the California Current and the Alboran Sea. WORK COMPLETED During...5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Naval Postgraduate School,Department of Meteorology (MR/Hy),589 Dyer Rd

  13. Wave-current interactions: model development and preliminary results

    Science.gov (United States)

    Mayet, Clement; Lyard, Florent; Ardhuin, Fabrice

    2013-04-01

    The coastal area concentrates many uses that require integrated management based on diagnostic and predictive tools to understand and anticipate the future of pollution from land or sea, and learn more about natural hazards at sea or activity on the coast. The realistic modelling of coastal hydrodynamics needs to take into account various processes which interact, including tides, surges, and sea state (Wolf [2008]). These processes act at different spatial scales. Unstructured-grid models have shown the ability to satisfy these needs, given that a good mesh resolution criterion is used. We worked on adding a sea state forcing in a hydrodynamic circulation model. The sea state model is the unstructured version of WAVEWATCH III c (Tolman [2008]) (which version is developed at IFREMER, Brest (Ardhuin et al. [2010]) ), and the hydrodynamic model is the 2D barotropic module of the unstructured-grid finite element model T-UGOm (Le Bars et al. [2010]). We chose to use the radiation stress approach (Longuet-Higgins and Stewart [1964]) to represent the effect of surface waves (wind waves and swell) in the barotropic model, as previously done by Mastenbroek et al. [1993]and others. We present here some validation of the model against academic cases : a 2D plane beach (Haas and Warner [2009]) and a simple bathymetric step with analytic solution for waves (Ardhuin et al. [2008]). In a second part we present realistic application in the Ushant Sea during extreme event. References Ardhuin, F., N. Rascle, and K. Belibassakis, Explicit wave-averaged primitive equations using a generalized Lagrangian mean, Ocean Modelling, 20 (1), 35-60, doi:10.1016/j.ocemod.2007.07.001, 2008. Ardhuin, F., et al., Semiempirical Dissipation Source Functions for Ocean Waves. Part I: Definition, Calibration, and Validation, J. Phys. Oceanogr., 40 (9), 1917-1941, doi:10.1175/2010JPO4324.1, 2010. Haas, K. A., and J. C. Warner, Comparing a quasi-3D to a full 3D nearshore circulation model: SHORECIRC and

  14. THE PROPOSED QUADRUPLE SYSTEM SZ HERCULIS: REVISED LITE MODEL AND ORBITAL STABILITY STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Hinse, Tobias Cornelius; Lee, Jae Woo; Lee, Chung-Uk [Advanced Astronomy and Space Science Division, Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of); Gozdziewski, Krzysztof [Nicolaus Copernicus University, Torun Centre for Astronomy, PL-87-100 Torun (Poland); Haghighipour, Nader, E-mail: tchinse@gmail.com [Institute for Astronomy and NASA Astrobiology Institute, University of Hawaii, 96822 HI (United States)

    2012-08-15

    In a recent study, Lee et al. presented new photometric follow-up timing observations of the semidetached binary system SZ Herculis and proposed the existence of two hierarchical cirumbinary companions. Based on the light-travel time effect, the two low-mass M-dwarf companions are found to orbit the binary pair on moderate to high eccentric orbits. The derived periods of these two companions are close to a 2:1 mean-motion orbital resonance. We have studied the stability of the system using the osculating orbital elements as presented by Lee et al. Results indicate an orbit-crossing architecture exhibiting short-term dynamical instabilities leading to the escape of one of the proposed companions. We have examined the system's underlying model parameter space by following a Monte Carlo approach and found an improved fit to the timing data. A study of the stability of our best-fitting orbits also indicates that the proposed system is generally unstable. If the observed anomalous timing variations of the binary period is due to additional circumbinary companions, then the resulting system should exhibit a long-term stable orbital configuration much different from the orbits suggested by Lee et al. We, therefore, suggest that based on Newtonian-dynamical considerations, the proposed quadruple system cannot exist. To uncover the true nature of the observed period variations of this system, we recommend future photometric follow-up observations that could further constrain eclipse-timing variations and/or refine light-travel time models.

  15. Testing Benjamin Graham’s net current asset value model

    Directory of Open Access Journals (Sweden)

    Chongsoo An

    2015-02-01

    Full Text Available The objective of this paper is to empirically test one of Graham’s investment methods based on the net current asset value (NCAV. The NCAV is truly unique, and conservative, and commonly known as the net-net method.  The ratio of the net current asset value to market value (NCAV/MV was employed in this study to test a stock’s performance comparing to the performance of S&P 500 as the market index. We used all stocks in Portfolio123 whose raw data were supplied by Compustat, Standard & Poors, Capital IQ, and Reuters for the period of January 2, 1999 to August 31, 2012. The overall results show that the firms with high net current asset values outperform the market. These results are strong in the up market. It can be argued that the firms with a high NCAV/MV ratio are likely to move toward their fundamental value and generate high excess return because its stock prices are now undervalued. The implications of the study are: (a a positive NCAV/MV ratio may be a good indicator of the underpriced security; (b investing in the growth period and avoiding the downturn period leads investors to earn much higher returns from the firms with a high NCAV/MV ratio; and (c The NCAV/MV strategy requires a longer holding period of the portfolio in order to generate excess returns.

  16. The equatorial electrojet current modelling from SWARM satellite data

    Science.gov (United States)

    Benaissa, Mahfoud

    2016-07-01

    Equatorial ElectroJet (EEJ) is an intense eastward electric current circulating in the ionospheric magnetic equator band between 100 and 130 km of altitude in E region. These currents vary by day, by season, by solar activity, and also with the main magnetic field of internal origin. The irregularity of the ionosphere has a major impact on the performance of communication systems and navigation (GPS), industry.... Then it becomes necessary study the characteristics of EEJ. In this paper, we present a study of the equatorial electrojet (EEJ) phenomenon along one year (2014) period. In addition, the satellite data used in this study are obtained with SWARM satellite scalar magnetometer data respecting magnetically quiet days with KP < 2. In this paper, we process to separate and extract the electrojet intensity signal from other recorded signal-sources interfering with the main signal and reduce considerably the signal to noise ratio during the SWARM measurements. This pre-processing step allows removing all external contributions in regard to EEJ intensity value. Key words: Ionosphere (Equatorial ionosphere; Electric fields and currents; Equatorial electrojet (EEJ)); SWARM.

  17. Current advancements and challenges in soil-root interactions modelling

    Science.gov (United States)

    Schnepf, Andrea; Huber, Katrin; Abesha, Betiglu; Meunier, Felicien; Leitner, Daniel; Roose, Tiina; Javaux, Mathieu; Vanderborght, Jan; Vereecken, Harry

    2015-04-01

    Roots change their surrounding soil chemically, physically and biologically. This includes changes in soil moisture and solute concentration, the exudation of organic substances into the rhizosphere, increased growth of soil microorganisms, or changes in soil structure. The fate of water and solutes in the root zone is highly determined by these root-soil interactions. Mathematical models of soil-root systems in combination with non-invasive techniques able to characterize root systems are a promising tool to understand and predict the behaviour of water and solutes in the root zone. With respect to different fields of applications, predictive mathematical models can contribute to the solution of optimal control problems in plant recourse efficiency. This may result in significant gains in productivity, efficiency and environmental sustainability in various land use activities. Major challenges include the coupling of model parameters of the relevant processes with the surrounding environment such as temperature, nutrient concentration or soil water content. A further challenge is the mathematical description of the different spatial and temporal scales involved. This includes in particular the branched structures formed by root systems or the external mycelium of mycorrhizal fungi. Here, reducing complexity as well as bridging between spatial scales is required. Furthermore, the combination of experimental and mathematical techniques may advance the field enormously. Here, the use of root system, soil and rhizosphere models is presented through a number of modelling case studies, including image based modelling of phosphate uptake by a root with hairs, model-based optimization of root architecture for phosphate uptake from soil, upscaling of rhizosphere models, modelling root growth in structured soil, and the effect of root hydraulic architecture on plant water uptake efficiency and drought resistance.

  18. Modeling of the influences of multiple modulated electron cyclotron current drive on NTMs in rotating plasma

    Science.gov (United States)

    Long, Chen; Jinyuan, Liu; Ping, Duan; Guangrui, Liu; Xingyu, Bian

    2017-02-01

    In this work, physical models of neoclassical tearing modes (NTMs) including bootstrap current and multiple modulated electron cyclotron current drive model are applied. Based on the specific physical problems during the suppression of NTMs by driven current, this work compares the efficiency of continuous and modulated driven currents, and simulates the physical processes of multiple modulated driven currents on suppressing rotating magnetic island. It is found that when island rotates along the poloidal direction, the suppression ability of continuous driven current can be massively reduced due to current deposition outside the island separatrix and reverse deposition direction at the X point, which can be avoided by current drive modulation. Multiple current drive has a better suppressing effect than single current drive. This work gives realistic numerical simulations by optimizing the model and parameters based on the experiments, which could provide references for successful suppression of NTMs in future advanced tokamak such as international thermonuclear experimental reactor.

  19. A Statistical Model of Current Loops and Magnetic Monopoles

    Energy Technology Data Exchange (ETDEWEB)

    Ayyer, Arvind, E-mail: arvind@math.iisc.ernet.in [Indian Institute of Science, Department of Mathematics (India)

    2015-12-15

    We formulate a natural model of loops and isolated vertices for arbitrary planar graphs, which we call the monopole-dimer model. We show that the partition function of this model can be expressed as a determinant. We then extend the method of Kasteleyn and Temperley-Fisher to calculate the partition function exactly in the case of rectangular grids. This partition function turns out to be a square of a polynomial with positive integer coefficients when the grid lengths are even. Finally, we analyse this formula in the infinite volume limit and show that the local monopole density, free energy and entropy can be expressed in terms of well-known elliptic functions. Our technique is a novel determinantal formula for the partition function of a model of isolated vertices and loops for arbitrary graphs.

  20. Mobile Education-proposing a Mobile Learning Model for Designing an Institutional Mobile Scenario

    Directory of Open Access Journals (Sweden)

    Ouiame Filali Marzouki

    2014-05-01

    Full Text Available Inspired by the theory of activity, the context model and previous researches, this paper proposes a model bringing together the key concepts of a mobile learning environment based on the concept of contextualization, major advantage of mobile learning. It details the learning mobile environment, its main components, its characteristics and the different interactions between them. The proposed model meets the constraint of mobile learning complementarity, allowing flexibility in its integration with classroom learning such as e-learning or blended learning. It mainly improves upon conventional learning methods and advocates others such as situated, interactive and connectivist learning. Indeed, research several that mobile learning enhances the educational program and reinstates it into the daily lives of learners through their own mobile technologies. Properly implemented, Mobile Learning can make learning activities as fun, as beneficial and certainly more motivating for learners and educators especially in the mobile era where traditional learning methods don’t meet all learners’ needs. Mobiles, connected and in constant social interaction, learners require learning systems more adapted to their communicative and interactive nature. This paper is an early implementation of this concept in learning systems. It aims to help educators to integrate mobile technologies into their learning activities without alternating their educational goals.

  1. Alternative models of disorders of traumatic stress based on the new ICD-11 proposals.

    Science.gov (United States)

    Shevlin, M; Hyland, P; Karatzias, T; Fyvie, C; Roberts, N; Bisson, J I; Brewin, C R; Cloitre, M

    2017-05-01

    Although there is emerging evidence for the factorial validity of the distinction between post-traumatic stress disorder (PTSD) and complex PTSD (CPTSD) proposed in ICD-11, such evidence has been predominantly based on using selected items from individual scales that describe these factors. We have attempted to address this gap in the literature by testing a range of alternative models of disorders of traumatic stress using a broader range of symptoms and standardized measures. Participants in this cross-sectional study were a sample of individuals who were referred for psychological therapy to a National Health Service (NHS) trauma centre in Scotland (N = 195). Participants were recruited over a period of 18 months and completed measures of stressful life events, DSM-5 PTSD, emotion dysregulation, self-esteem and interpersonal difficulties. Overall, results indicate that a structural model incorporating six first-order factors (re-experiencing, avoidance of traumatic reminders, sense of threat, affective dysregulation, negative self-concept and disturbances in relationships) and two second-order factors (PTSD and disturbances in self-organization [DSO]) was the best fitting. The model presented with good concurrent validity. Childhood trauma was found to be more strongly associated with DSO than with PTSD. Our results are in support of the ICD-11 proposals for PTSD and CPTSD. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. Current Scientific Evidence for a Polarized Cardiovascular Endurance Training Model.

    Science.gov (United States)

    Hydren, Jay R; Cohen, Bruce S

    2015-12-01

    Recent publications have provided new scientific evidence for a modern aerobic or cardiovascular endurance exercise prescription that optimizes the periodization cycle and maximizes potential endurance performance gains in highly trained individuals. The traditional threshold, high volume, and high-intensity training models have displayed limited improvement in actual race pace in (highly) trained individuals while frequently resulting in overreaching or overtraining (physical injury and psychological burnout). A review of evidence for replacing these models with the proven polarized training model seems warranted. This review provides a short history of the training models, summarizes 5 key studies, and provides example training programs for both the pre- and in-season periods. A polarized training program is characterized by an undulating nonlinear periodization model with nearly all the training time spent at a "light" (≤13) and "very hard" (≥17) pace with very limited time at "hard" (14-16) or race pace (6-20 Rating of Perceived Exertion [RPE] scale). To accomplish this, the polarization training model has specific high-intensity workouts separated by one or more long slow distance workouts, with the exercise intensity remaining below ventilatory threshold (VT) 1 and/or blood lactate of less than 2 mM (A.K.A. below race pace). Effect sizes for increasing aerobic endurance performance for the polarized training model are consistently superior to that of the threshold training model. Performing a polarized training program may be best accomplished by: going easy on long slow distance workouts, avoiding "race pace" and getting after it during interval workouts.

  3. Current approaches to model extracellular electrical neural microstimulation

    Directory of Open Access Journals (Sweden)

    Sébastien eJoucla

    2014-02-01

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

  4. Development and current status of the "Cambridge" loudness models.

    Science.gov (United States)

    Moore, Brian C J

    2014-10-13

    This article reviews the evolution of a series of models of loudness developed in Cambridge, UK. The first model, applicable to stationary sounds, was based on modifications of the model developed by Zwicker, including the introduction of a filter to allow for the effects of transfer of sound through the outer and middle ear prior to the calculation of an excitation pattern, and changes in the way that the excitation pattern was calculated. Later, modifications were introduced to the assumed middle-ear transfer function and to the way that specific loudness was calculated from excitation level. These modifications led to a finite calculated loudness at absolute threshold, which made it possible to predict accurately the absolute thresholds of broadband and narrowband sounds, based on the assumption that the absolute threshold corresponds to a fixed small loudness. The model was also modified to give predictions of partial loudness-the loudness of one sound in the presence of another. This allowed predictions of masked thresholds based on the assumption that the masked threshold corresponds to a fixed small partial loudness. Versions of the model for time-varying sounds were developed, which allowed prediction of the masked threshold of any sound in a background of any other sound. More recent extensions incorporate binaural processing to account for the summation of loudness across ears. In parallel, versions of the model for predicting loudness for hearing-impaired ears have been developed and have been applied to the development of methods for fitting multichannel compression hearing aids.

  5. Proposed Core Competencies and Empirical Validation Procedure in Competency Modeling: Confirmation and Classification.

    Science.gov (United States)

    Baczyńska, Anna K; Rowiński, Tomasz; Cybis, Natalia

    2016-01-01

    Competency models provide insight into key skills which are common to many positions in an organization. Moreover, there is a range of competencies that is used by many companies. Researchers have developed core competency terminology to underline their cross-organizational value. The article presents a theoretical model of core competencies consisting of two main higher-order competencies called performance and entrepreneurship. Each of them consists of three elements: the performance competency includes cooperation, organization of work and goal orientation, while entrepreneurship includes innovativeness, calculated risk-taking and pro-activeness. However, there is lack of empirical validation of competency concepts in organizations and this would seem crucial for obtaining reliable results from organizational research. We propose a two-step empirical validation procedure: (1) confirmation factor analysis, and (2) classification of employees. The sample consisted of 636 respondents (M = 44.5; SD = 15.1). Participants were administered a questionnaire developed for the study purpose. The reliability, measured by Cronbach's alpha, ranged from 0.60 to 0.83 for six scales. Next, we tested the model using a confirmatory factor analysis. The two separate, single models of performance and entrepreneurial orientations fit quite well to the data, while a complex model based on the two single concepts needs further research. In the classification of employees based on the two higher order competencies we obtained four main groups of employees. Their profiles relate to those found in the literature, including so-called niche finders and top performers. Some proposal for organizations is discussed.

  6. Proposed realization of the Dicke-model quantum phase transition in an optical cavity QED system

    CERN Document Server

    Dimer, F; Estienne, B; Parkins, A S

    2006-01-01

    The Dicke model consisting of an ensemble of two-state atoms interacting with a single quantized mode of the electromagnetic field exhibits a zero-temperature phase transition at a critical value of the dipole coupling strength. We propose a scheme based on multilevel atoms and cavity-mediated Raman transitions to realise an effective Dicke system operating in the phase transition regime. Output light from the cavity carries signatures of the critical behavior which is analyzed for the thermodynamic limit where the number of atoms is very large.

  7. Maximizing Return on Investment (ROI of Enterprise Resource Planning Systems (ERP for Nonprofit Organizations: Proposed Model

    Directory of Open Access Journals (Sweden)

    Hussain A.H. Awad

    2013-08-01

    Full Text Available ERP are the core business application for many companies; and it’s very apparent that organization spending on those systems is in a continuous rise, on the other hand this also raised the issue of how can ERP systems pay those spending; and when that investment can reach ROI point. In this study the researcher will attempt to propose a model that contains guide line phases for nonprofit organizations in order to speed up the stage in which ERP system can reach ROI, the researcher opted for universities since they are one of the main nonprofit organizations that employ ERP in their processes.

  8. Proposal for a Model of Co-Management for the Small Community Water Supplies in Colombia

    Directory of Open Access Journals (Sweden)

    Andrea Bernal

    2014-01-01

    Full Text Available This paper reviews the conceptual evolution of Community Based Monitoring (CBM from different approaches : social capital, common pool resources and co-management or collaborative management, and presents the main co-management strategies applied to water supply at small scale: local and community driven development (LCDD and sustainable services at scale (SSS. Supported by this theoretical background, and in order to improve access to drinking water in rural communities in Colombia, the authors propose a co-management model for small and community water supplies.

  9. Modeling of stored charge in metallized biaxially oriented polypropylene film capacitors based on charging current measurement

    Science.gov (United States)

    Li, Hua; Wang, Bowen; Li, Zhiwei; Liu, De; Lin, Fuchang; Dai, Ling; Zhang, Qin; Chen, Yaohong

    2013-10-01

    Metallized biaxially oriented polypropylene film (BOPP) capacitors are widely used in pulsed power systems. When the capacitor is used as the energy storage equipment under high electric field, more charges should be provided to maintain the voltage of the capacitor. This should be ascribed to the completion of the slow polarization which may take several hours or even longer. This paper focuses on the stored charge in metallized BOPP film capacitors. The modeling of the stored charge by the equivalent conversion of circuits is conducted to analyse the slow polarization in the BOPP film. The 3-RC network is proposed to represent the time-dependent charge stored in the capacitor. A charging current measurement system is established to investigate the charge storage property of the capacitor. The measurement system can measure the long time charging current with a sampling rate of 300Hz. The total charge calculated by the charging current indicates that the stored charge in the capacitor under the electric field of 400 V/μm is 13.5% larger than the product of the voltage and the capacitance measured by the AC bridge. The nonlinear effect of the electric field on the slow polarization charge is also demonstrated. And the simulation of charge storage based on the 3-RC network can match well with the trend of the stored charge increasing with the time.

  10. Hyperpolarization-Activated Current, I f, in Mathematical Models of Rabbit Sinoatrial Node Pacemaker Cells

    Science.gov (United States)

    Verkerk, Arie O.

    2013-01-01

    A typical feature of sinoatrial (SA) node pacemaker cells is the presence of an ionic current that activates upon hyperpolarization. The role of this hyperpolarization-activated current, I f, which is also known as the “funny current” or “pacemaker current,” in the spontaneous pacemaker activity of SA nodal cells remains a matter of intense debate. Whereas some conclude that I f plays a fundamental role in the generation of pacemaker activity and its rate control, others conclude that the role of I f is limited to a modest contribution to rate control. The ongoing debate is often accompanied with arguments from computer simulations, either to support one's personal view or to invalidate that of the antagonist. In the present paper, we review the various mathematical descriptions of I f that have been used in computer simulations and compare their strikingly different characteristics with our experimental data. We identify caveats and propose a novel model for I f based on our experimental data. PMID:23936852

  11. A proposed study on the transplacental transport of parabens in the human placental perfusion model

    DEFF Research Database (Denmark)

    Mathiesen, Line; Zuri, Giuseppina; Andersen, Maria H

    2013-01-01

    Human exposure to parabens as a preservative used in personal care products is of increasing concern, as there is evidence from in vivo and in vitro studies of hormone disruption in association with exposure to parabens. Transport across the placenta could be critical for risk assessment......, but the available data are sparse. The aim is to develop a method for estimating fetal exposure, via the placenta, to the most commonly-used parabens, by using a human placental perfusion model. The use of human tissue is vital for determining human fetal exposure, because animal studies are of little relevance......, since the placenta exhibits significant interspecies variation. An HPLC model is currently being established to simultaneously quantify four different parabens, namely, methylparaben, ethylparaben, propylparaben and butylparaben, and their main metabolite, p-hydroxybenzoic acid. With this model, we aim...

  12. A current circuit model of pulsar radio emission

    CERN Document Server

    Kunzl, T A; Jessner, A; Kunzl, Th.

    2002-01-01

    We present the outline of a new model for the coherent radio emission of pulsars that succeeds in reproducing the energetics and brightness temperatures of the observed radio emission from the observationally deduced distances of 50-100 pulsar radii above the neutron star in a narrow region. The restrictions imposed by energy conservation, plasma dynamics of the coherent radiation process and propagation effects are used to apply the action of a plasma process like coherent inverse Compton scattering (CICS) (see Benford, 1992). In accordance with our findings (Kunzl et al. 1998a) this process requires Lorentz factors of about 10 which are lower than in most other radio emission models. This implies that no significant pair production can take place near the surface and we expect charge densities close to the Goldreich-Julian value (Goldreich & Julian (1969)). To fulfill the energetic and electrodynamic constraints the model requires constant re-acceleration in dissipation regions which can be interpreted ...

  13. Toward a new model of scientific publishing: Discussion and a proposal

    Directory of Open Access Journals (Sweden)

    Dwight eKravitz

    2011-12-01

    Full Text Available The current system of publishing in the neurosciences, is notable for its redundancy, inconsistency, sluggishness, and opacity. These problems persist, and grow worse, because of a continuing failure to fully leverage new technology. Online access has eliminated space limits within peer-reviewed journals, yet we continue to deny publication. Each submission of a rejected manuscript requires the entire machinery of peer review to creak to life. This redundancy causes delays, inconsistency, and increases the burden on authors, reviewers, and editors. Further, reviewers serve a key role in the process but their performance is not tracked; yet alone rewarded. This misalignment of incentives contributes to the inconsistency and sluggishness that pervades peer review. The current system also interferes with the primary purpose of modern journals, providing a quick way of prioritizing the literature. Reviews are written to gauge publication rather than scientific merit and there is no guarantee that the journal’s criteria agree with those of an individual researcher, making any prioritization opaque and noisy at best.The focus of this special issue is the future form of post-publication reception, and the development of a marketplace where a paper rises and falls based on its reception from the field. However, the information that accompanies a paper into the marketplace is as important as the marketplace’s mechanics. Beyond suggestions as to the mechanisms of reception, we propose an update to the system of publishing in which publication is guaranteed, but pre-publication peer review still occurs, giving the authors the opportunity to revise their work following a mini pre-reception from the field. This step also provides a consistent set of rankings and reviews to the marketplace, allowing for early prioritization and stabilizing its early dynamics. We further propose to improve the general quality of reviewing by providing tangible rewards to

  14. Theoretical Modeling of Internal Hydraulic Jump in Density Currents

    CERN Document Server

    Firoozabadi, Bahar; Aryanfar, Asghar; Afshin, Hossein

    2013-01-01

    In this paper, we propose an analytical framework for internal hydraulic jumps. Density jumps or internal hydraulic jumps occur when a supper critical flow of water discharges into a stagnant layer of water with slightly different density. The approach used here is control volume method which is also used to analyze ordinary hydraulic jumps. The important difference here is that entrainment is taken into account. Using conservation equations with the aid of some simplifying assumptions we come to an equation that gives jump downstream height as function of jump upstream characteristics and the entrainment. To determine the magnitude of downstream height we use an experimental equation for calculating the entrainment. Finally we verify our framework by comparing the height that we gain from the derived equation with some experimental data.

  15. The double-temperature ratchet model and current reversal of coupled Brownian motors

    CERN Document Server

    Li, Chen-pu; Zheng, Zhi-gang

    2016-01-01

    Based on the transport features and experimental phenomena observed in studies of molecular motors, we proposed the double-temperature ratchet model of coupled motors to reveal the dynamical mechanism of cooperative transport of motors with two heads, where the interactions and the asynchronous between two motor heads are taken into account. We investigated the collective unidirectional transport of coupled system, and find that the direction of motion can be inversed under certain conditions. Inverse motion can be achieved by modulating the coupling strength, the coupling free length and the asymmetric efficient of the periodic potential, which is understood in terms of the effective-potential theory. The dependence of directed current on various parameters is studied systematically. Directed transport of coupled Brownian motors can be manipulated and optimized by adjusting pulsating period or the phase shift of the pulsating temperature.

  16. An adaptive attitude algorithm based on a current statistical model for maneuvering acceleration

    Directory of Open Access Journals (Sweden)

    Menglong Wang

    2017-02-01

    Full Text Available A current statistical model for maneuvering acceleration using an adaptive extended Kalman filter (CS-MAEKF algorithm is proposed to solve problems existing in conventional extended Kalman filters such as large estimation error and divergent tendencies in the presence of continuous maneuvering acceleration. A membership function is introduced in this algorithm to adaptively modify the upper and lower limits of loitering vehicles’ maneuvering acceleration and for real-time adjustment of maneuvering acceleration variance. This allows the algorithm to have superior static and dynamic performance for loitering vehicles undergoing different maneuvers. Digital simulations and dynamic flight testing show that the yaw angle accuracy of the algorithm is 30% better than conventional algorithms, and pitch and roll angle calculation precision is improved by 60%. The mean square deviation of heading and attitude angle error during dynamic flight is less than 3.05°. Experimental results show that CS-MAEKF meets the application requirements of miniature loitering vehicles.

  17. Angular velocity estimation based on star vector with improved current statistical model Kalman filter.

    Science.gov (United States)

    Zhang, Hao; Niu, Yanxiong; Lu, Jiazhen; Zhang, He

    2016-11-20

    Angular velocity information is a requisite for a spacecraft guidance, navigation, and control system. In this paper, an approach for angular velocity estimation based merely on star vector measurement with an improved current statistical model Kalman filter is proposed. High-precision angular velocity estimation can be achieved under dynamic conditions. The amount of calculation is also reduced compared to a Kalman filter. Different trajectories are simulated to test this approach, and experiments with real starry sky observation are implemented for further confirmation. The estimation accuracy is proved to be better than 10-4  rad/s under various conditions. Both the simulation and the experiment demonstrate that the described approach is effective and shows an excellent performance under both static and dynamic conditions.

  18. Current Status of cosmological models with mixed dark matter

    CERN Document Server

    Mikheeva, E V

    2000-01-01

    An analysis of cosmological mixed dark matter models in spatially flat Friedmann Universe with zero $\\Lambda$-term is presented. We argue that the introduction of cosmic gravity waves helps to satisfy observational constraints. The analysis of models is based on the confrontation with the mass function of clusters of galaxies and the CMB anisotropy. The implication of Press-Schechter formalism allowed to constrain $\\sigma_8=0.52 \\pm 0.01$. This normalisation of the spectrum of density perturbations has been used to calculate numerically the value of the large scale CMB anisotropy and the relative contribution of cosmological gravitational waves, T/S. We found that increasing $\\Omega_\

  19. The Proposed Quadruple System SZ Herculis: Revised LITE Model and Orbital Stability Study

    CERN Document Server

    Hinse, T C; Lee, J W; Haghighipour, N; Lee, C -U

    2012-01-01

    In a recent study, Lee et al. presented new photometric follow-up timing observations of the semi-detached binary system SZ Herculis and proposed the existence of two hierarchical cirumbinary companions. Based on the light-travel time effect, the two low-mass M-dwarf companions are found to orbit the binary pair on moderate to high eccentric orbits. The derived periods of these two companions are close to a 2:1 mean-motion orbital resonance. We have studied the stability of the system using the osculating orbital elements as presented by Lee et al. Results indicate an orbit-crossing architecture exhibiting short-term dynamical instabilities leading to the escape of one of the proposed companions. We have examined the system's underlying model parameter-space by following a Monte Carlo approach and found an improved fit to the timing data. A study of the stability of our best-fitting orbits also indicates that the proposed system is generally unstable. If the observed anomalous timing variations of the binary ...

  20. From representing to modelling knowledge: Proposing a two-step training for excellence in concept mapping

    Directory of Open Access Journals (Sweden)

    Joana G. Aguiar

    2017-09-01

    Full Text Available Training users in the concept mapping technique is critical for ensuring a high-quality concept map in terms of graphical structure and content accuracy. However, assessing excellence in concept mapping through structural and content features is a complex task. This paper proposes a two-step sequential training in concept mapping. The first step requires the fulfilment of low-order cognitive objectives (remember, understand and apply to facilitate novices’ development into good Cmappers by honing their knowledge representation skills. The second step requires the fulfilment of high-order cognitive objectives (analyse, evaluate and create to grow good Cmappers into excellent ones through the development of knowledge modelling skills. Based on Bloom’s revised taxonomy and cognitive load theory, this paper presents theoretical accounts to (1 identify the criteria distinguishing good and excellent concept maps, (2 inform instructional tasks for concept map elaboration and (3 propose a prototype for training users on concept mapping combining online and face-to-face activities. The proposed training application and the institutional certification are the next steps for the mature use of concept maps for educational as well as business purposes.

  1. Model-based Optimization and Feedback Control of the Current Density Profile Evolution in NSTX-U

    Science.gov (United States)

    Ilhan, Zeki Okan

    Nuclear fusion research is a highly challenging, multidisciplinary field seeking contributions from both plasma physics and multiple engineering areas. As an application of plasma control engineering, this dissertation mainly explores methods to control the current density profile evolution within the National Spherical Torus eXperiment-Upgrade (NSTX-U), which is a substantial upgrade based on the NSTX device, which is located in Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ. Active control of the toroidal current density profile is among those plasma control milestones that the NSTX-U program must achieve to realize its next-step operational goals, which are characterized by high-performance, long-pulse, MHD-stable plasma operation with neutral beam heating. Therefore, the aim of this work is to develop model-based, feedforward and feedback controllers that can enable time regulation of the current density profile in NSTX-U by actuating the total plasma current, electron density, and the powers of the individual neutral beam injectors. Motivated by the coupled, nonlinear, multivariable, distributed-parameter plasma dynamics, the first step towards control design is the development of a physics-based, control-oriented model for the current profile evolution in NSTX-U in response to non-inductive current drives and heating systems. Numerical simulations of the proposed control-oriented model show qualitative agreement with the high-fidelity physics code TRANSP. The next step is to utilize the proposed control-oriented model to design an open-loop actuator trajectory optimizer. Given a desired operating state, the optimizer produces the actuator trajectories that can steer the plasma to such state. The objective of the feedforward control design is to provide a more systematic approach to advanced scenario planning in NSTX-U since the development of such scenarios is conventionally carried out experimentally by modifying the tokamak's actuator

  2. A model proposal concerning balance scorecard application integrated with resource consumption accounting in enterprise performance management

    Directory of Open Access Journals (Sweden)

    ORHAN ELMACI

    2014-06-01

    Full Text Available The present study intended to investigate the “Balance Scorecard (BSC model integrated with Resource Consumption Accounting (RCA” which helps to evaluate the enterprise as matrix structure in its all parts. It aims to measure how much tangible and intangible values (assets of enterprises contribute to the enterprises. In other words, it measures how effectively, actively, and efficiently these values (assets are used. In short, it aims to measure sustainable competency of enterprises. As expressing the effect of tangible and intangible values (assets of the enterprise on the performance in mathematical and statistical methods is insufficient, it is targeted that RCA Method integrated with BSC model is based on matrix structure and control models. The effects of all complex factors in the enterprise on the performance (productivity and efficiency estimated algorithmically with cause and effect diagram. The contributions of matrix structures for reaching the management functional targets of the enterprises that operate in market competitive environment increasing day to day, is discussed. So in the context of modern management theories, as a contribution to BSC approach which is in the foreground in today’s administrative science of enterprises in matrix organizational structures, multidimensional performance evaluation model -RCA integrated with BSC Model proposal- is presented as strategic planning and strategic evaluation instrument.

  3. Statistical model and error analysis of a proposed audio fingerprinting algorithm

    Science.gov (United States)

    McCarthy, E. P.; Balado, F.; Silvestre, G. C. M.; Hurley, N. J.

    2006-01-01

    In this paper we present a statistical analysis of a particular audio fingerprinting method proposed by Haitsma et al.1 Due to the excellent robustness and synchronisation properties of this particular fingerprinting method, we would like to examine its performance for varying values of the parameters involved in the computation and ascertain its capabilities. For this reason, we pursue a statistical model of the fingerprint (also known as a hash, message digest or label). Initially we follow the work of a previous attempt made by Doets and Lagendijk 2-4 to obtain such a statistical model. By reformulating the representation of the fingerprint as a quadratic form, we present a model in which the parameters derived by Doets and Lagendijk may be obtained more easily. Furthermore, our model allows further insight into certain aspects of the behaviour of the fingerprinting algorithm not previously examined. Using our model, we then analyse the probability of error (P e) of the hash. We identify two particular error scenarios and obtain an expression for the probability of error in each case. We present three methods of varying accuracy to approximate P e following Gaussian noise addition to the signal of interest. We then analyse the probability of error following desynchronisation of the signal at the input of the hashing system and provide an approximation to P e for different parameters of the algorithm under varying degrees of desynchronisation.

  4. A Proposed Digital Forensics Business Model to Support Cybercrime Investigation in Indonesia

    Directory of Open Access Journals (Sweden)

    Yudi Prayudi

    2015-10-01

    Full Text Available Digital forensics will always include at least human as the one who performs activities, digital evidence as the main object, and process as a reference for the activities followed. The existing framework has not provided a description of the interaction between human, interaction between human and digital evidence, as well as interaction between human and the process itself. A business model approach can be done to provide the idea regarding the interaction in question. In this case, what has been generated by the author in the previous study through a business model of the digital chain of custody becomes the first step in constructing a business model of a digital forensics. In principle, the proposed business model already accommodates major components of digital forensics (human, digital evidence, process and also considers the interactions among the components. The business model suggested has contained several basic principles as described in The Regulation of Chief of Indonesian National Police (Perkap No 10/2010. This will give support to law enforcement to deal with cybercrime cases that are more frequent and more sophisticated, and can be a reference for each institution and organization to implement digital forensics activities.

  5. A Proposed Model for Measuring Performance of the University-Industry Collaboration in Open Innovation

    Directory of Open Access Journals (Sweden)

    Anca Draghici

    2017-06-01

    Full Text Available The paper aims to present a scientific approach to the creation, testing and validation of a model for performance measurement for university-industry collaboration (UIC. The main idea of the design process is to capitalize on existing success factors, facilitators and opportunities (motivation factors, knowledge transfer channels and identified benefits and to diminish or avoid potential threats and barriers that might interfere with such collaborations. The main purpose of the applied methodology is to identify solutions and measures to overcome the disadvantages, conflicts or risk issues and to facilitate the open innovation of industrial companies and universities. The methodology adopted was differentiated by two perspectives: (1 a business model reflecting the university perspective along with an inventory of key performance indicators (KPIs; (2 a performance measurement model (including performance criteria and indicators and an associated methodology (assimilated to an audit that could help companies increase collaboration with universities in the context of open innovation. In addition, in order to operationalize the proposed model (facilitating practical implementation, an Excel tool has been created to help identifying potential sources of innovation. The main contributions of the research concern the expansion of UICs knowledge to enhance open innovation and to define an effective performance measurement model and instrument (tested and validated by a case study for companies.

  6. Taenia solium: current understanding of laboratory animal models of taeniosis.

    Science.gov (United States)

    Flisser, A; Avila, G; Maravilla, P; Mendlovic, F; León-Cabrera, S; Cruz-Rivera, M; Garza, A; Gómez, B; Aguilar, L; Terán, N; Velasco, S; Benítez, M; Jimenez-Gonzalez, D E

    2010-03-01

    Neurocysticercosis is a public health problem in many developing countries and is the most frequent parasitic disease of the brain. The human tapeworm carrier is the main risk factor for acquiring neurocysticercosis. Since the parasite lodges only in the human intestine, experimental models of Taenia solium taeniosis have been explored. Macaques, pigs, dogs, cats and rabbits are unsuccessful hosts even in immunodepressed status. By contrast, rodents are adequate hosts since tapeworms with mature, pregravid and, in some cases, gravid proglottids develop after infection. In this review, information that has been generated with experimental models of taeniosis due to T. solium is discussed. Initially, the use of the model for immunodiagnosis of human taeniosis and evaluation of intervention measures is summarized. Next, descriptions of tapeworms and comparison of hamsters, gerbils and other mammals as experimental models are discussed, as well as data on the humoral immune response, the inflammatory reaction and the production of cytokines associated to Th1 and Th2 responses in the intestinal mucosa. Finally, evaluation of protection induced against the development of tapeworms by recombinant T. solium calreticulin in hamsters is summarized and compared to other studies.

  7. Business model innovation: Past research, current debates, and future directions

    DEFF Research Database (Denmark)

    Hossain, Mokter

    2017-01-01

    Purpose – The purpose of this paper is to provide state-of-the-art knowledge about business model innovation (BMI) and suggest avenues for future research. Design/methodology/approach – A systematic literature review approach was adopted with thematic analysis being conducted on 92 articles...

  8. Current Status of Superheat Spray Modeling With NCC

    Science.gov (United States)

    Raju, M. S.; Bulzan, Dan L.

    2012-01-01

    An understanding of liquid fuel behavior at superheat conditions is identified to be a topic of importance in the design of modern supersonic engines. As a part of the NASA's supersonics project office initiative on high altitude emissions, we have undertaken an effort to assess the accuracy of various existing CFD models used in the modeling of superheated sprays. As a part of this investigation, we have completed the implementation of a modeling approach into the national combustion code (NCC), and then applied it to investigate the following three cases: (1) the validation of a flashing jet generated by the sudden release of pressurized R134A from a cylindrical nozzle, (2) the differences between two superheat vaporization models were studied based on both hot and cold flow calculations of a Parker-Hannifin pressure swirl atomizer, (3) the spray characteristics generated by a single-element LDI (Lean Direct Injector) experiment were studied to investigate the differences between superheat and non-superheat conditions. Further details can be found in the paper.

  9. Proposal for the Quantum Simulation of the CP(2) Model on Optical Lattices

    CERN Document Server

    Laflamme, Catherine; Dalmonte, Marcello; Gerber, Urs; Mejía-Díaz, Héctor; Bietenholz, Wolfgang; Wiese, Uwe-Jens; Zoller, Peter

    2015-01-01

    The 2d CP(N-1) models share a number of features with QCD, like asymptotic freedom, a dynamically generated mass gap and topological sectors. They have been formulated and analysed successfully in the framework of the so-called D-theory, which provides a smooth access to the continuum limit. In that framework, we propose an experimental set-up for the quantum simulation of the CP(2) model. It is based on ultra-cold Alkaline-Earth Atoms (AEAs) located on the sites of an optical lattice, where the nuclear spins represent the relevant degrees of freedom. We present numerical results for the correlation length and for the real time decay of a false vacuum, to be compared with such a future experiment. The latter could also enable the exploration of theta-vacua and of the phase diagram at finite chemical potentials, since it does not suffer from any sign problem.

  10. T helper 17 cells may drive neuroprogression in major depressive disorder: Proposal of an integrative model.

    Science.gov (United States)

    Slyepchenko, Anastasiya; Maes, Michael; Köhler, Cristiano A; Anderson, George; Quevedo, João; Alves, Gilberto S; Berk, Michael; Fernandes, Brisa S; Carvalho, André F

    2016-05-01

    The exact pathophysiology of major depressive disorder (MDD) remains elusive. The monoamine theory, which hypothesizes that MDD emerges as a result of dysfunctional serotonergic, dopaminergic and noradrenergic pathways, has guided the therapy of this illness for several decades. More recently, the involvement of activated immune, oxidative and nitrosative stress pathways and of decreased levels of neurotrophic factors has provided emerging insights regarding the pathophysiology of MDD, leading to integrated theories emphasizing the complex interplay of these mechanisms that could lead to neuroprogression. In this review, we propose an integrative model suggesting that T helper 17 (Th17) cells play a pivotal role in the pathophysiology of MDD through (i) microglial activation, (ii) interactions with oxidative and nitrosative stress, (iii) increases of autoantibody production and the propensity for autoimmunity, (iv) disruption of the blood-brain barrier, and (v) dysregulation of the gut mucosa and microbiota. The clinical and research implications of this model are discussed.

  11. A Biogeographic Assessment of the Stellwagen Bank National Marine Sanctuary - Surface Current Model Outputs

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Surface and sub-surface current model outputs were obtained from researchers at the University of Massachusetts-Boston to examine spatial and temporal current...

  12. A Biogeographic Assessment of the Stellwagen Bank National Marine Sanctuary - Subsurface Current Model Outputs

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Surface and sub-surface current model outputs were obtained from researchers at the University of Massachusetts-Boston to examine spatial and temporal current...

  13. On the current-driven model in the classical electrodynamics of continuous media.

    Science.gov (United States)

    Markel, Vadim A

    2010-12-01

    The current-driven model in which a continuous medium is excited by a pre-determined current which overlaps with the medium in all points in space but is not subject to constitutive relations is critically analyzed.

  14. Model of convection mass transfer in titanium alloy at low energy high current electron beam action

    Science.gov (United States)

    Sarychev, V. D.; Granovskii, A. Yu; Nevskii, S. A.; Konovalov, S. V.; Gromov, V. E.

    2017-01-01

    The convection mixing model is proposed for low-energy high-current electron beam treatment of titanium alloys, pre-processed by heterogeneous plasma flows generated via explosion of carbon tape and powder TiB2. The model is based on the assumption vortices in the molten layer are formed due to the treatment by concentrated energy flows. These vortices evolve as the result of thermocapillary convection, arising because of the temperature gradient. The calculation of temperature gradient and penetration depth required solution of the heat problem with taking into account the surface evaporation. However, instead of the direct heat source the boundary conditions in phase transitions were changed in the thermal conductivity equation, assuming the evaporated material takes part in the heat exchange. The data on the penetration depth and temperature distribution are used for the thermocapillary model. The thermocapillary model embraces Navier-Stocks and convection heat transfer equations, as well as the boundary conditions with the outflow of evaporated material included. The solution of these equations by finite elements methods pointed at formation of a multi-vortices structure when electron-beam treatment and its expansion over new zones of material. As the result, strengthening particles are found at the depth exceeding manifold their penetration depth in terms of the diffusion mechanism.

  15. Current reinforcement model reproduces center-in-center vein trajectory of Physarum polycephalum.

    Science.gov (United States)

    Akita, Dai; Schenz, Daniel; Kuroda, Shigeru; Sato, Katsuhiko; Ueda, Kei-Ichi; Nakagaki, Toshiyuki

    2017-06-01

    Vein networks span the whole body of the amoeboid organism in the plasmodial slime mould Physarum polycephalum, and the network topology is rearranged within an hour in response to spatio-temporal variations of the environment. It has been reported that this tube morphogenesis is capable of solving mazes, and a mathematical model, named the 'current reinforcement rule', was proposed based on the adaptability of the veins. Although it is known that this model works well for reproducing some key characters of the organism's maze-solving behaviour, one important issue is still open: In the real organism, the thick veins tend to trace the shortest possible route by cutting the corners at the turn of corridors, following a center-in-center trajectory, but it has not yet been examined whether this feature also appears in the mathematical model, using corridors of finite width. In this report, we confirm that the mathematical model reproduces the center-in-center trajectory of veins around corners observed in the maze-solving experiment. © 2017 Japanese Society of Developmental Biologists.

  16. Proposed Model for Integrating RAMS Method in the Design Process in Construction

    Directory of Open Access Journals (Sweden)

    Saad Al-Jibouri

    2010-05-01

    Full Text Available There is a growing trend in the Netherlands for outsourcing public construction activities to the private sector through the use of integrated contracts. There is also an increasing emphasis from public clients on the use of RAMS and life cycle costing (LCC in the design process of infrastructural projects to improve the performance of designed systems and optimize the project cost. RAMS is an acronym for `reliability, availability, maintainability and safety' and represents a collection of techniques to provide predictions of the performance targets of the required system. Increasingly, RAMS targets are being specified in invitation to tender or contract documents and the parties responsible for the design are required to provide evidence of its application in their design. Recent evidence from practice, complemented with a literature study, has shown that the knowledge and application of RAMS in infrastructural designs are in their infancy compared with other industrial sectors and many designers in construction do not have the necessary knowledge and experience to apply it. This paper describes a proposed model for the integration of RAMS and LCC into the design process in construction. A variation of the model for the application of RAMS in `design, build, finance and maintain' (DBFM contracts that include maintenance requirements is also proposed. The two models involve providing guidelines to simplify the application of RAMs by the designers. The model has been validated for its practicality and usefulness during a workshop by experienced designers. DOI: 10.3763/aedm.2008.0100 Published in the Journal AEDM - Volume 5, Number 4, 2009 , pp. 179-192(14

  17. Proposal of a function for modelling the hourly frequency distributions of photosynthetically active radiation

    Science.gov (United States)

    Tovar-Pescador, J.; Pozo-Vazquez, D.; Batlles, J.; López, G.; Muñoz-Vicente, D.

    2004-10-01

    Solar irradiance is a key factor in the physiological processes of living beings. To obtain simple correlations for the estimation of the performance of biological systems, which transform the solar energy by photosynthesis, and to generate synthetic data, it is necessary to know the frequency distributions of photosynthetically active radiation (PAR). In this work we carried out an analysis of the properties of hourly values of PAR data, using 9 years of data collected in southern Spain. In particularly, its dependence on the optical mass, for all type of skies including cloudy skies, is studied. Results shows that, for a given value of the optical mass, the PAR density distributions are not symmetrical and have a certain degree of bimodality. The increment in the optical mass value has two effects on the PAR distributions, the first one is a shift toward lower values of the maximum and the second one is a decrease in the range of PAR values. Finally, a model of the frequency distribution of PAR values, based on a new kind of functions related to the Boltzmann’s statistic, is proposed. The parameters of these functions depend just on the optical mass. Results show a very good agreement between the data and the model proposed.

  18. Developing a primary care research agenda through collaborative efforts - a proposed "6E" model.

    Science.gov (United States)

    Tan, Ngiap Chuan; Ng, Chirk Jenn; Rosemary, Mitchell; Wahid, Khan; Goh, Lee Gan

    2014-01-01

    Primary care research is at a crossroad in South Pacific. A steering committee comprising a member of WONCA Asia Pacific Regional (APR) council and the President of Fiji College of General Practitioners garnered sponsorship from Fiji Ministry of Health, WONCA APR and pharmaceutical agencies to organize the event in October 2013. This paper describes the processes needed to set up a national primary research agenda through the collaborative efforts of local stakeholders and external facilitators using a test case in South Pacific. The setting was a 2-day primary care research workshop in Fiji. The steering committee invited a team of three external facilitators from the Asia-Pacific region to organize and operationalize the workshop. The eventual participants were 3 external facilitators, 6 local facilitators, and 29 local primary care physicians, academics, and local medical leaders from Fiji and South Pacific Islands. Pre-workshop and main workshop programs were drawn up by the external facilitators, using participants' input of research topics relating to their local clinical issues of interest. Course notes were prepared and distributed before the workshop. In the workshop, proposed research topics were shortlisted by group discussion and consensus. Study designs were proposed, scrutinized, and adopted for further research development. The facilitators reviewed the processes in setting the research agenda after the workshop and conceived the proposed 6E model. These processes can be grouped for easy reference, comprising the pre-workshop stages of "entreat", "enlist", "engage", and the workshop stages of "educe", "empower", and "encapsulate". The 6E model to establish a research agenda is conceptually logical. Its feasibility can be further tested in its application in other situation where research agenda setting is the critical step to improve the quality of primary care.

  19. An extended Kundu-Eckhaus equation for modeling dynamics of rogue waves in a chaotic wave-current field

    CERN Document Server

    Bayindir, Cihan

    2016-01-01

    In this paper we propose an extended Kundu-Eckhaus equation (KEE) for modeling the dynamics of skewed rogue waves emerging in the vicinity of a wave blocking point due to opposing current. The equation we propose is a KEE with an additional potential term therefore the results presented in this paper can easily be generalized to study the quantum tunneling properties of the rogue waves and ultrashort (femtosecond) pulses of the KEE. In the frame of the extended KEE, we numerically show that the chaotic perturbations of the ocean current trigger the occurrence of the rogue waves on the ocean surface. We propose and implement a split-step scheme and show that the extended KEE that we propose is unstable against random chaotic perturbations in the current profile. These perturbations transform the monochromatic wave field into a chaotic sea state with many peaks. We numerically show that the shapes of rogue waves due to perturbations in the current profile closely follow the form of rational rogue wave solutions...

  20. Comparison of bootstrap current and plasma conductivity models applied in a self-consistent equilibrium calculation for Tokamak plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Maria Celia Ramos; Ludwig, Gerson Otto [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil). Lab. Associado de Plasma]. E-mail: mcr@plasma.inpe.br

    2004-07-01

    Different bootstrap current formulations are implemented in a self-consistent equilibrium calculation obtained from a direct variational technique in fixed boundary tokamak plasmas. The total plasma current profile is supposed to have contributions of the diamagnetic, Pfirsch-Schlueter, and the neoclassical Ohmic and bootstrap currents. The Ohmic component is calculated in terms of the neoclassical conductivity, compared here among different expressions, and the loop voltage determined consistently in order to give the prescribed value of the total plasma current. A comparison among several bootstrap current models for different viscosity coefficient calculations and distinct forms for the Coulomb collision operator is performed for a variety of plasma parameters of the small aspect ratio tokamak ETE (Experimento Tokamak Esferico) at the Associated Plasma Laboratory of INPE, in Brazil. We have performed this comparison for the ETE tokamak so that the differences among all the models reported here, mainly regarding plasma collisionality, can be better illustrated. The dependence of the bootstrap current ratio upon some plasma parameters in the frame of the self-consistent calculation is also analysed. We emphasize in this paper what we call the Hirshman-Sigmar/Shaing model, valid for all collisionality regimes and aspect ratios, and a fitted formulation proposed by Sauter, which has the same range of validity but is faster to compute than the previous one. The advantages or possible limitations of all these different formulations for the bootstrap current estimate are analysed throughout this work. (author)

  1. Modeling and control of the output current of a Reformed Methanol Fuel Cell system

    DEFF Research Database (Denmark)

    Justesen, Kristian Kjær; Andreasen, Søren Juhl; Pasupathi, Sivakumar

    2015-01-01

    In this work, a dynamic Matlab SIMULINK model of the relationship between the fuel cell current set point of a Reformed Methanol Fuel Cell system and the output current of the system is developed. The model contains an estimated fuel cell model, based on a polarization curve and assumed first order...

  2. Is it appropriate to model turbidity currents with the Three-Equation Model?

    CERN Document Server

    Hu, Peng; He, Zhiguo

    2015-01-01

    The Three-Equation Model (TEM) was developed in the 1980s to model turbidity currents (TCs) and has been widely used ever since. However, its physical justification was questioned because self-accelerating TCs simulated with the steady TEM seemed to violate the turbulent kinetic energy balance. This violation was considered as a result of very strong sediment erosion that consumes more turbulent kinetic energy than is produced. To confine bed erosion and thus remedy this issue, the Four-Equation Model (FEM) was introduced by assuming a proportionality between the bed shear stress and the turbulent kinetic energy. Here we analytically proof that self-accelerating TCs simulated with the original steady TEM actually never violate the turbulent kinetic energy balance, provided that the bed drag coefficient is not unrealistically low. We find that stronger bed erosion, surprisingly, leads to more production of turbulent kinetic energy due to conversion of potential energy of eroded material into kinetic energy of ...

  3. Neutral-point current modeling and control for Neutral-Point Clamped three-level converter drive with small DC-link capacitors

    DEFF Research Database (Denmark)

    Maheshwari, Ram Krishan; Munk-Nielsen, Stig; Busquets-Monge, Sergio

    2011-01-01

    -point current. A new simplified model of the neutral-point voltage dynamics is derived for the proposed modulation strategy. This model shows that the neutral-point current is proportional to the power drawn from the converter and it enables the use of well established classical control theory for neutral......-point voltage controller design. A PI controller is used for neutral-point voltage balance. The implementation of the proposed modulation strategy and controller is simple. It does not require any information about the output phase currents. The controller is implemented in a 7.5 kW induction machine based...

  4. Fault Modeling and Testing for Analog Circuits in Complex Space Based on Supply Current and Output Voltage

    Directory of Open Access Journals (Sweden)

    Hongzhi Hu

    2015-01-01

    Full Text Available This paper deals with the modeling of fault for analog circuits. A two-dimensional (2D fault model is first proposed based on collaborative analysis of supply current and output voltage. This model is a family of circle loci on the complex plane, and it simplifies greatly the algorithms for test point selection and potential fault simulations, which are primary difficulties in fault diagnosis of analog circuits. Furthermore, in order to reduce the difficulty of fault location, an improved fault model in three-dimensional (3D complex space is proposed, which achieves a far better fault detection ratio (FDR against measurement error and parametric tolerance. To address the problem of fault masking in both 2D and 3D fault models, this paper proposes an effective design for testability (DFT method. By adding redundant bypassing-components in the circuit under test (CUT, this method achieves excellent fault isolation ratio (FIR in ambiguity group isolation. The efficacy of the proposed model and testing method is validated through experimental results provided in this paper.

  5. A mathematical modeling proposal for a Multiple Tasks Periodic Capacitated Arc Routing Problem

    Directory of Open Access Journals (Sweden)

    Cleverson Gonçalves dos Santos

    2015-12-01

    Full Text Available The countless accidents and incidents occurred at dams at the last years, propelled the development of politics related with dams safety. One of the strategies is related to the plan for instrumentation and monitoring of dams. The monitoring demands from the technical team the reading of the auscultation data, in order to periodically monitor the dam. The monitoring plan of the dam can be modeled as a problem of mathematical program of the periodical capacitated arcs routing program (PCARP. The PCARP is considered as a generalization of the classic problem of routing in capacitated arcs (CARP due to two characteristics: 1 Planning period larger than a time unity, as that vehicle make several travels and; 2 frequency of associated visits to the arcs to be serviced over the planning horizon. For the dam's monitoring problem studied in this work, the frequent visits, along the time horizon, it is not associated to the arc, but to the instrument with which is intended to collect the data. Shows a new problem of Multiple tasks Periodic Capacitated Arc Routing Problem and its elaboration as an exact mathematical model. The new main characteristics presented are: multiple tasks to be performed on each edge or edges; different frequencies to accomplish each of the tasks; heterogeneous fleet; and flexibility for more than one vehicle passing through the same edge at the same day. The mathematical model was implemented and examples were generated randomly for the proposed model's validation.

  6. Transcranial Direct Current Stimulation and behavioral models of smoking addiction

    Directory of Open Access Journals (Sweden)

    Paige eFraser

    2012-08-01

    Full Text Available While few studies have applied transcranial direct current stimulation (tDCS to smoking addiction, existing work suggests that the intervention holds promise for altering the complex system by which environmental cues interact with cravings to drive behavior. Imaging and repetitive transcranial magnetic stimulation (rTMS studies suggest that increased dorsolateral prefrontal cortex (DLPFC activation and integrity may be associated with increased resistance to smoking cues. Anodal tDCS of the DLPFC, believed to boost activation, reduces cravings in response to these cues. The finding that noninvasive stimulation modifies cue induced cravings has profound implications for understanding the processes underlying addiction and relapse. TDCS can also be applied to probe mechanisms underlying and supporting nicotine addiction, as was done in a pharmacologic study that applied nicotine, tDCS, and TMS paired associative stimulation to find that stopping nicotine after chronic use induces a reduction in plasticity, causing difficulty in breaking free from association between cues and cravings. This mini-review will place studies that apply tDCS to smokers in the context of research involving the neural substrates of nicotine addiction.

  7. The Current Status of Kinematic Solar Dynamo Models

    Indian Academy of Sciences (India)

    Arnab Rai Choudhuri

    2000-09-01

    This review provides a historical overview of how research in kinematic solar dynamo modeling evolved during the last few decades and assesses the present state of research. The early pioneering papers assumed the dynamo to operate in the convection zone. It was suggested in the 1980s that the dynamo operates in a thin layer at the bottom of the convection zone. Some researchers in recent years are arguing that the poloidal field is produced near the surface—an idea that goes back to Babcock (1961) and Leighton (1969).

  8. Projected current density comparison in tDCS block and smooth FE modeling.

    Science.gov (United States)

    Indahlastari, Aprinda; Chauhan, Munish; Sadleir, Rosalind J

    2016-08-01

    Current density distribution and projected current density calculation following transcranial direct current stimulation (tDCS) forward model in a human head were compared between two modeling pipelines: block and smooth. Block model was directly constructed from MRI voxel resolution and simulated in C. Smooth models underwent a boundary smoothing process by applying recursive Gaussian filters and simulated in COMSOL. Three smoothing levels were added to determine their effects on current density distribution compared to block models. Median current density percentage differences were calculated in anterior superior temporal gyrus (ASTG), hippocampus (HIP), inferior frontal gyrus (IFG), occipital lobes (OCC) and precentral gyrus (PRC) and normalized against a baseline value. A maximum of + 20% difference in median current density was found for three standard electrode montages: F3-RS, T7-T8 and Cz-Oz. Furthermore, median current density percentage differences in each montage target brain structures were found to be within + 7%. Higher levels of smoothing increased median current density percentage differences in T7-T8 and Cz-Oz target structures. However, while demonstrating similar trends in each montage, additional smoothing levels showed no clear relationship between their smoothing effects and calculated median current density in the five cortical structures. Finally, relative L2 error in reconstructed projected current density was found to be 17% and 21% for block and smooth pipelines, respectively. Overall, a block model workflow may be a more attractive alternative for simulating tDCS stimulation because involves a shorter modeling time and independence from commercial modeling platforms.

  9. Numerical modelling of the proposed WFIRST-AFTA coronagraphs and their predicted optical performances

    CERN Document Server

    Krist, John; Mennesson, Bertrand

    2015-01-01

    The WFIRST-AFTA 2.4 m telescope will provide in the next decade the opportunity to host a coronagraph for the imaging and spectroscopy of planets and disks. The telescope, however, is not ideal, given its obscured aperture. Only recently have coronagraph designs been thoroughly investigated that can efficiently work with this configuration. Three coronagraph designs, the hybrid Lyot, the shaped pupil, and the phase-induced amplitude-apodization complex mask coronagraph (PIAA-CMC) have been selected for further development by the AFTA project. Real-world testbed demonstrations of these have just begun, so for now the most reliable means of evaluating their potential performance comes from numerical modeling incorporating diffraction propagation, realistic system models, and simulated wavefront sensing and control. Here we present the methods of performance evaluation and results for the current coronagraph designs.

  10. Enamel remineralization by fluoride-releasing materials: proposal of a pH-cycling model.

    Science.gov (United States)

    Rodrigues, Eliana; Delbem, Alberto Carlos Botazzo; Pedrini, Denise; Cavassan, Luciana

    2010-01-01

    This study proposes a pH-cycling model for verifying the dose-response relationship in fluoride-releasing materials on remineralization in vitro. Sixty bovine enamel blocks were selected for the surface microhardness test (SMH1). Artificial caries lesions were induced and surface microhardness test (SMH2) was performed. Forty-eight specimens were prepared with Z 100, Fluroshield, Vitremer and Vitremer ¼ diluted - powder/liquid, and subjected to a pH-cycling model to promote remineralization. After pH-cycling, final surface microhardness (SMH3) was assessed to calculate percent recovery of surface microhardness (%SMHR). Fluoride present in enamel (μg F/mm3) and in the pH-cycling solutions (μg F) was measured. Cross-sectional microhardness was used to calculate mineral content (∆Z). There was no significant difference between Z 100 and control groups on analysis performed on - %SMHR, ∆Z, μg F and mg F/mm3 (p>0.05). Results showed a positive correlation between %SMHR and μg F/mm3 (r=0.9770; p=0.004), %SMHR and μg F (r=0.9939; p=0.0000001), ∆ and μg F/mm3 (r=0.9853; p=0.0002), ∆ and μg F (r=0.9975; p=0.0000001) and between μg F/mm3 and μg F (r=0.9819; p=0.001). The pH-cycling model proposed was able to verify in vitro dose-response relationship of fluoride-releasing materials on remineralization.

  11. Modeling evaluation of integrated strategies to meet proposed dissolved oxygen standards for the Chicago waterway system.

    Science.gov (United States)

    Melching, Charles S; Ao, Yaping; Alp, Emre

    2013-02-15

    The Chicago Waterway System (CWS) is a 113.8 km branching network of navigable waterways controlled by hydraulic structures in which the majority of flow is treated sewage effluent and there are periods of substantial combined sewer overflow. The Illinois Pollution Control Board (IPCB) designated the majority of the CWS as Secondary Contact and Indigenous Aquatic Life Use waters in the 1970s and made small alterations to these designations in 1988. Between 1988 and 2002 substantial improvements in the pollution control and water-quality management facilities were made in the Chicago area. The results of a Use Attainability Analysis led the Illinois Environmental Protection Agency (IEPA) to propose the division of the CWS into two new aquatic life use classes with appropriate dissolved oxygen (DO) standards. To aid the IPCB in their deliberations regarding the appropriate water use classifications and DO standards for the CWS, the DUFLOW model that is capable of simulating hydraulics and water-quality processes under unsteady-flow conditions was used to evaluate integrated strategies of water-quality improvement facilities that could meet the proposed DO standards during representative wet (2001) and dry (2003) years. A total of 28 new supplementary aeration stations with a maximum DO load of 80 or 100 g/s and aerated flow transfers at three locations in the CWS would be needed to achieve the IEPA proposed DO standards 100% of the time for both years. A much simpler and less costly (≈one tenth of the cost) system of facilities would be needed to meet the IEPA proposed DO standards 90% of the time. In theory, the combinations of flow augmentation and new supplemental aeration stations can achieve 100% compliance with the IEPA proposed DO standards, however, 100% compliance will be hard to achieve in practice because of-(1) difficulties in determining when to turn on the aeration stations and (2) localized heavy loads of pollutants during storms that may yield

  12. Current Methods of Natural Hazards Communication used within Catastrophe Modelling

    Science.gov (United States)

    Dawber, C.; Latchman, S.

    2012-04-01

    In the field of catastrophe modelling, natural hazards need to be explained every day to (re)insurance professionals so that they may understand estimates of the loss potential of their portfolio. The effective communication of natural hazards to city professionals requires different strategies to be taken depending on the audience, their prior knowledge and respective backgrounds. It is best to have at least three sets of tools in your arsenal for a specific topic, 1) an illustration/animation, 2) a mathematical formula and 3) a real world case study example. This multi-faceted approach will be effective for those that learn best by pictorial means, mathematical means or anecdotal means. To show this we will use a set of real examples employed in the insurance industry of how different aspects of natural hazards and the uncertainty around them are explained to city professionals. For example, explaining the different modules within a catastrophe model such as the hazard, vulnerability and loss modules. We highlight how recent technology such as 3d plots, video recording and Google Earth maps, when used properly can help explain concepts quickly and easily. Finally we also examine the pitfalls of using overly-complicated visualisations and in general how counter-intuitive deductions may be made.

  13. A debate on current eating disorder diagnoses in light of neurobiological findings: is it time for a spectrum model?

    Directory of Open Access Journals (Sweden)

    Brooks Samantha

    2012-07-01

    Full Text Available Abstract Background Sixty percent of eating disorders do not meet criteria for anorexia- or bulimia nervosa, as defined by the Diagnostic and Statistical Manual version 4 (DSM-IV. Instead they are diagnosed as ‘eating disorders not otherwise specified’ (EDNOS. Discrepancies between criteria and clinical reality currently hampering eating disorder diagnoses in the DSM-IV will be addressed by the forthcoming DSM-V. However, future diagnoses for eating disorders will rely on current advances in the fields of neuroimaging and genetics for classification of symptoms that will ultimately improve treatment. Discussion Here we debate the classification issues, and discuss how brain imaging and genetic discoveries might be interwoven into a model of eating disorders to provide better classification and treatment. The debate concerns: a current issues in the classification of eating disorders in the DSM-IV, b changes proposed for DSM-V, c neuroimaging eating disorder research and d genetic eating disorder research. Summary We outline a novel evidence-based ‘impulse control’ spectrum model of eating disorders. A model of eating disorders is proposed that will aid future diagnosis of symptoms, coinciding with contemporary suggestions by clinicians and the proposed changes due to be published in the DSM-V.

  14. Short-run and Current Analysis Model in Statistics

    Directory of Open Access Journals (Sweden)

    Constantin Anghelache

    2006-01-01

    Full Text Available Using the short-run statistic indicators is a compulsory requirement implied in the current analysis. Therefore, there is a system of EUROSTAT indicators on short run which has been set up in this respect, being recommended for utilization by the member-countries. On the basis of these indicators, there are regular, usually monthly, analysis being achieved in respect of: the production dynamic determination; the evaluation of the short-run investment volume; the development of the turnover; the wage evolution: the employment; the price indexes and the consumer price index (inflation; the volume of exports and imports and the extent to which the imports are covered by the exports and the sold of trade balance. The EUROSTAT system of indicators of conjuncture is conceived as an open system, so that it can be, at any moment extended or restricted, allowing indicators to be amended or even removed, depending on the domestic users requirements as well as on the specific requirements of the harmonization and integration. For the short-run analysis, there is also the World Bank system of indicators of conjuncture, which is utilized, relying on the data sources offered by the World Bank, The World Institute for Resources or other international organizations statistics. The system comprises indicators of the social and economic development and focuses on the indicators for the following three fields: human resources, environment and economic performances. At the end of the paper, there is a case study on the situation of Romania, for which we used all these indicators.

  15. Short-run and Current Analysis Model in Statistics

    Directory of Open Access Journals (Sweden)

    Constantin Mitrut

    2006-03-01

    Full Text Available Using the short-run statistic indicators is a compulsory requirement implied in the current analysis. Therefore, there is a system of EUROSTAT indicators on short run which has been set up in this respect, being recommended for utilization by the member-countries. On the basis of these indicators, there are regular, usually monthly, analysis being achieved in respect of: the production dynamic determination; the evaluation of the short-run investment volume; the development of the turnover; the wage evolution: the employment; the price indexes and the consumer price index (inflation; the volume of exports and imports and the extent to which the imports are covered by the exports and the sold of trade balance. The EUROSTAT system of indicators of conjuncture is conceived as an open system, so that it can be, at any moment extended or restricted, allowing indicators to be amended or even removed, depending on the domestic users requirements as well as on the specific requirements of the harmonization and integration. For the short-run analysis, there is also the World Bank system of indicators of conjuncture, which is utilized, relying on the data sources offered by the World Bank, The World Institute for Resources or other international organizations statistics. The system comprises indicators of the social and economic development and focuses on the indicators for the following three fields: human resources, environment and economic performances. At the end of the paper, there is a case study on the situation of Romania, for which we used all these indicators.

  16. Socio-economic vulnerability to natural hazards - proposal for an indicator-based model

    Science.gov (United States)

    Eidsvig, U.; McLean, A.; Vangelsten, B. V.; Kalsnes, B.; Ciurean, R. L.; Argyroudis, S.; Winter, M.; Corominas, J.; Mavrouli, O. C.; Fotopoulou, S.; Pitilakis, K.; Baills, A.; Malet, J. P.

    2012-04-01

    Vulnerability assessment, with respect to natural hazards, is a complex process that must consider multiple dimensions of vulnerability, including both physical and social factors. Physical vulnerability refers to conditions of physical assets, and may be modeled by the intensity and magnitude of the hazard, the degree of physical protection provided by the natural and built environment, and the physical robustness of the exposed elements. Social vulnerability refers to the underlying factors leading to the inability of people, organizations, and societies to withstand impacts from the natural hazards. Social vulnerability models can be used in combination with physical vulnerability models to estimate both direct losses, i.e. losses that occur during and immediately after the impact, as well as indirect losses, i.e. long-term effects of the event. Direct impact of a landslide typically includes casualties and damages to buildings and infrastructure while indirect losses may e.g. include business closures or limitations in public services. The direct losses are often assessed using physical vulnerability indicators (e.g. construction material, height of buildings), while indirect losses are mainly assessed using social indicators (e.g. economical resources, demographic conditions). Within the EC-FP7 SafeLand research project, an indicator-based method was proposed to assess relative socio-economic vulnerability to landslides. The indicators represent the underlying factors which influence a community's ability to prepare for, deal with, and recover from the damage associated with landslides. The proposed model includes indicators representing demographic, economic and social characteristics as well as indicators representing the degree of preparedness and recovery capacity. Although the model focuses primarily on the indirect losses, it could easily be extended to include more physical indicators which account for the direct losses. Each indicator is individually

  17. Proposal of a model for the analysis of a text as a communicative event Proposal of a model for the analysis of a text as a communicative event

    Directory of Open Access Journals (Sweden)

    Bolaños Cuéllar Sergio

    1995-06-01

    Full Text Available

    An attempt has been made to present a model for the analysis of a text as a communicative event. The presupposition underlying this task is that it is actually possible - and to some extent desirable - to construct a 'model' as a descriptive device, powerful enough to account for the text as the linguistic unit of the communicative interaction. The different components of the model (Sender, Receiver, Text, Text Levels, Competences, Socio-Psychological characterization of participants, and Context are described, as well as their functioning and interaction. Then the model is applied for the analysis of a text ('a sticky problem', and some conclusions are drawn on the model as a whole, its advantages and shortcomings.

    An attempt has been made to present a model for the analysis of a text as a communicative evento The presupposition underlying this task is that it is actually possible and to some extent desirable - to construct a 'model'as a descriptive device, powerful enough to account for the text as the linguistic unit of the communicative interaction. The different components of the model (Sender, Receiver, Text, Text Levels, Competences, Socio-Psychological characterization of participants, and Context are described, as well as their functioning and interaction. Then the model is applied for the analysis of a text ('A Sticky Problem', and some conclusions are drawn on the model as a whole, its advantages and shortcomings.

  18. A proposed centralised distribution model for the South African automotive component industry

    Directory of Open Access Journals (Sweden)

    Micheline J. Naude

    2009-12-01

    Full Text Available Purpose: This article explores the possibility of developing a distribution model, similar to the model developed and implemented by the South African pharmaceutical industry, which could be implemented by automotive component manufacturers for supply to independent retailers. Problem Investigated: The South African automotive components distribution chain is extensive with a number of players of varying sizes, from the larger spares distribution groups to a number of independent retailers. Distributing to the smaller independent retailers is costly for the automotive component manufacturers. Methodology: This study is based on a preliminary study of an explorative nature. Interviews were conducted with a senior staff member from a leading automotive component manufacturer in KwaZulu Natal and nine participants at a senior management level at five of their main customers (aftermarket retailers. Findings: The findings from the empirical study suggest that the aftermarket component industry is mature with the role players well established. The distribution chain to the independent retailer is expensive in terms of transaction and distribution costs for the automotive component manufacturer. A proposed centralised distribution model for supply to independent retailers has been developed which should reduce distribution costs for the automotive component manufacturer in terms of (1 the lowest possible freight rate; (2 timely and controlled delivery; and (3 reduced congestion at the customer's receiving dock. Originality: This research is original in that it explores the possibility of implementing a centralised distribution model for independent retailers in the automotive component industry. Furthermore, there is a dearth of published research on the South African automotive component industry particularly addressing distribution issues. Conclusion: The distribution model as suggested is a practical one and should deliver added value to automotive

  19. A Proposed Model for Assessing Organisational Culture Towards Achieving Business Objectives

    Directory of Open Access Journals (Sweden)

    Hafez Salleh

    2011-09-01

    Full Text Available Most of the traditional business performances measures are based on productivity and process criteria, which mainly focus on method of investment appraisal such as payback method, return on investment (ROI, cost-benefits analysis (CBA, net present value (NPV, internal rate of return (IRR. However, the measurement scales of business performance are not limited to those measures. One element that has strong correlation to the business performances is ‘organisational culture’. Many studies proved that one of the significant criteria for achieving desired business objectives is the right organisational culture within workplace. Basically, the measurement of organisational culture is reflecting on two distinct elements: organisational culture and business objectives. In broader perspective, an organisation is considered effective if it meets its business objectives. This paper aims to present and discuss the preliminary culture model to indicate the culture performance within organisational. The model has been developed through literature review, expert opinion and experience which is anticipated of being able to potentially measure the culture capability of organisations across industries to “successfully achieve business objectives”. The model is composed of six progressive stages of maturity that an organisation can achieve its culture performance. For each maturity stage, the model describes a set of characteristics that must be in place for the company to achieve each stage. The validity of the proposed model will be tested by a few case studies. The idea is to provide managers with a qualitative measurement tools to enable them to identify where culture improvements are required within their organisations and to indicate their readiness for achieving business objectives.

  20. Global model of zenith tropospheric delay proposed based on EOF analysis

    Science.gov (United States)

    Sun, Langlang; Chen, Peng; Wei, Erhu; Li, Qinzheng

    2017-07-01

    Tropospheric delay is one of the main error budgets in Global Navigation Satellite System (GNSS) measurements. Many empirical correction models have been developed to compensate this delay, and models which do not require meteorological parameters have received the most attention. This study established a global troposphere zenith total delay (ZTD) model, called Global Empirical Orthogonal Function Troposphere (GEOFT), based on the empirical orthogonal function (EOF, also known as geographically weighted PCAs) analysis method and the Global Geodetic Observing System (GGOS) Atmosphere data from 2012 to 2015. The results showed that ZTD variation could be well represented by the characteristics of the EOF base function Ek and associated coefficients Pk. Here, E1 mainly signifies the equatorial anomaly; E2 represents north-south asymmetry, and E3 and E4 reflects regional variation. Moreover, P1 mainly reflects annual and semiannual variation components; P2 and P3 mainly contains annual variation components, and P4 displays semiannual variation components. We validated the proposed GEOFT model using tropospheric delay data of GGOS ZTD grid data and the tropospheric product of the International GNSS Service (IGS) over the year 2016. The results showed that GEOFT model has high accuracy with bias and RMS of -0.3 and 3.9 cm, respectively, with respect to the GGOS ZTD data, and of -0.8 and 4.1 cm, respectively, with respect to the global IGS tropospheric product. The accuracy of GEOFT demonstrating that the use of the EOF analysis method to characterize ZTD variation is reasonable.

  1. MODEL REQUEST FOR PROPOSALS TO PROVIDE ENERGY AND OTHER ATTRIBUTES FROM AN OFFSHORE WIND POWER PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    Jeremy Firestone; Dawn Kurtz Crompton

    2011-10-22

    This document provides a model RFP for new generation. The 'base' RFP is for a single-source offshore wind RFP. Required modifications are noted should a state or utility seek multi-source bids (e.g., all renewables or all sources). The model is premised on proposals meeting threshold requirements (e.g., a MW range of generating capacity and a range in terms of years), RFP issuer preferences (e.g., likelihood of commercial operation by a date certain, price certainty, and reduction in congestion), and evaluation criteria, along with a series of plans (e.g., site, environmental effects, construction, community outreach, interconnection, etc.). The Model RFP places the most weight on project risk (45%), followed by project economics (35%), and environmental and social considerations (20%). However, if a multi-source RFP is put forward, the sponsor would need to either add per-MWh technology-specific, life-cycle climate (CO2), environmental and health impact costs to bid prices under the 'Project Economics' category or it should increase the weight given to the 'Environmental and Social Considerations' category.

  2. A proposed model for assessing service quality in small machining and industrial maintenance companies

    Directory of Open Access Journals (Sweden)

    Morvam dos Santos Netto

    2014-11-01

    Full Text Available Machining and industrial maintenance services include repair (corrective maintenance of equipments, activities involving the assembly-disassembly of equipments, fault diagnosis, machining operations, forming operations, welding processes, assembly and test of equipments. This article proposes a model for assessing the quality of services provided by small machining and industrial maintenance companies, since there is a gap in the literature regarding this issue and because the importance of small service companies in socio-economic development of the country. The model is an adaptation of the SERVQUAL instrument and the criteria determining the quality of services are designed according to the service cycle of a typical small machining and industrial maintenance company. In this sense, the Moments of Truth have been considered in the preparation of two separate questionnaires. The first questionnaire contains 24 statements that reflect the expectations of customers, and the second one contains 24 statements that measure perceptions of service performance. An additional item was included in each questionnaire to assess, respectively, the overall expectation about the services and the overall company performance. Therefore, it is a model that considers the interfaces of the client/supplier relationship, the peculiarities of the machining and industrial maintenance service sector and the company size.

  3. MODEL REQUEST FOR PROPOSALS TO PROVIDE ENERGY AND OTHER ATTRIBUTES FROM AN OFFSHORE WIND POWER PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    Jeremy Firestone; Dawn Kurtz Crompton

    2011-10-22

    This document provides a model RFP for new generation. The 'base' RFP is for a single-source offshore wind RFP. Required modifications are noted should a state or utility seek multi-source bids (e.g., all renewables or all sources). The model is premised on proposals meeting threshold requirements (e.g., a MW range of generating capacity and a range in terms of years), RFP issuer preferences (e.g., likelihood of commercial operation by a date certain, price certainty, and reduction in congestion), and evaluation criteria, along with a series of plans (e.g., site, environmental effects, construction, community outreach, interconnection, etc.). The Model RFP places the most weight on project risk (45%), followed by project economics (35%), and environmental and social considerations (20%). However, if a multi-source RFP is put forward, the sponsor would need to either add per-MWh technology-specific, life-cycle climate (CO2), environmental and health impact costs to bid prices under the 'Project Economics' category or it should increase the weight given to the 'Environmental and Social Considerations' category.

  4. A Proposed Model for Infant and Child Oral Health Promotion in India

    Science.gov (United States)

    Jawdekar, Ashwin Muralidhar

    2013-01-01

    Dental caries is an increasing burden in the developing countries. A proper budgetary allocation for treating dental diseases in an enormous population such as India is impractical, where resources are inadequate for major health challenges such as malnutrition and gastrointestinal and respiratory infections in children. An integrated, directed population approach targeting children is much needed. The existing machinery of successful public health campaigns such as the “Pulse Polio” and the “Mid-Day-Meals Scheme” of the Government of India can be used for oral health promotion for children. India has about 300 dental colleges and countrywide branches of the Indian Dental Association that can provide manpower for the program. An innovative, large-scale “Fit for School” program in Philippines is a model for an integrated approach for children's health and has proved to be cost-effective and viable. A model for oral health promotion in infants and children of India, combining age-specific initiatives for health education, nutrition, hygiene, and fluoride use, is proposed. The model could be implemented to evaluate the oral health status of children, knowledge and knowledge gain of the community health workers, and acceptability and sustainability of the preventive programs (fluoride varnish and preschool and school tooth brushing) pragmatically. PMID:24288533

  5. A Proposed Model for Infant and Child Oral Health Promotion in India

    Directory of Open Access Journals (Sweden)

    Ashwin Muralidhar Jawdekar

    2013-01-01

    Full Text Available Dental caries is an increasing burden in the developing countries. A proper budgetary allocation for treating dental diseases in an enormous population such as India is impractical, where resources are inadequate for major health challenges such as malnutrition and gastrointestinal and respiratory infections in children. An integrated, directed population approach targeting children is much needed. The existing machinery of successful public health campaigns such as the “Pulse Polio” and the “Mid-Day-Meals Scheme” of the Government of India can be used for oral health promotion for children. India has about 300 dental colleges and countrywide branches of the Indian Dental Association that can provide manpower for the program. An innovative, large-scale “Fit for School” program in Philippines is a model for an integrated approach for children’s health and has proved to be cost-effective and viable. A model for oral health promotion in infants and children of India, combining age-specific initiatives for health education, nutrition, hygiene, and fluoride use, is proposed. The model could be implemented to evaluate the oral health status of children, knowledge and knowledge gain of the community health workers, and acceptability and sustainability of the preventive programs (fluoride varnish and preschool and school tooth brushing pragmatically.

  6. Proposed Reference Model for Guiding Teachers to Perform Ward Round Teaching

    Directory of Open Access Journals (Sweden)

    Luís Alberto Corona Martínez

    2014-06-01

    Full Text Available Ward round teaching is an essential professional medical activity as an organizational form of teaching in undergraduate medical education. Its great importance for shaping a professional "personality" is well recognized by the faculty; as well as its extremely complex implementation and development of the necessary skills. The problem to be solved in this paper is related to the need to help younger clinical teachers in undergraduate medical education to develop the skills to conduct ward round teaching; which would be achieved through appropriate guidance on how to perform this activity. Based on this, the teaching staff in the Department of Clinical Sciences of the Dr. Raúl Dorticós Torrado Faculty of Medical Sciences in Cienfuegos has designed a model or representation of ward round teaching to be used as a guide. The main results include the development of a model with two variants, according to the care provided to a recently admitted patient or an already known patient; and the definition of conditions, both in practical and educational areas, which should be considered for the proper implementation of the activity. The model is not a complete representation of the ward round teaching, thus the proposal is open to review and improvement; and its use is based on its adaptation to the particularities of the different disciplines and learning scenarios.

  7. Progress and Current Challenges in Modeling Large RNAs.

    Science.gov (United States)

    Somarowthu, Srinivas

    2016-02-27

    Recent breakthroughs in next-generation sequencing technologies have led to the discovery of several classes of non-coding RNAs (ncRNAs). It is now apparent that RNA molecules are not only just carriers of genetic information but also key players in many cellular processes. While there has been a rapid increase in the number of ncRNA sequences deposited in various databases over the past decade, the biological functions of these ncRNAs are largely not well understood. Similar to proteins, RNA molecules carry out a function by forming specific three-dimensional structures. Understanding the function of a particular RNA therefore requires a detailed knowledge of its structure. However, determining experimental structures of RNA is extremely challenging. In fact, RNA-only structures represent just 1% of the total structures deposited in the PDB. Thus, computational methods that predict three-dimensional RNA structures are in high demand. Computational models can provide valuable insights into structure-function relationships in ncRNAs and can aid in the development of functional hypotheses and experimental designs. In recent years, a set of diverse RNA structure prediction tools have become available, which differ in computational time, input data and accuracy. This review discusses the recent progress and challenges in RNA structure prediction methods.

  8. Proton currents constrain structural models of voltage sensor activation

    Science.gov (United States)

    Randolph, Aaron L; Mokrab, Younes; Bennett, Ashley L; Sansom, Mark SP; Ramsey, Ian Scott

    2016-01-01

    The Hv1 proton channel is evidently unique among voltage sensor domain proteins in mediating an intrinsic ‘aqueous’ H+ conductance (GAQ). Mutation of a highly conserved ‘gating charge’ residue in the S4 helix (R1H) confers a resting-state H+ ‘shuttle’ conductance (GSH) in VGCs and Ci VSP, and we now report that R1H is sufficient to reconstitute GSH in Hv1 without abrogating GAQ. Second-site mutations in S3 (D185A/H) and S4 (N4R) experimentally separate GSH and GAQ gating, which report thermodynamically distinct initial and final steps, respectively, in the Hv1 activation pathway. The effects of Hv1 mutations on GSH and GAQ are used to constrain the positions of key side chains in resting- and activated-state VS model structures, providing new insights into the structural basis of VS activation and H+ transfer mechanisms in Hv1. DOI: http://dx.doi.org/10.7554/eLife.18017.001 PMID:27572256

  9. Current understanding of divertor detachment: experiments and modelling

    Energy Technology Data Exchange (ETDEWEB)

    Wischmeier, W; Groth, M; Kallenbach, A; Chankin, A; Coster, D; Dux, R; Herrmann, A; Muller, H; Pugno, R; Reiter, D; Scarabosio, A; Watkins, J; Team, T D; Team, A U

    2008-05-23

    A qualitative as well as quantitative evaluation of experimentally observed plasma parameters in the detached regime proves to be difficult for several tokamaks. A series of ohmic discharges have been performed in ASDEX Upgrade and DIII-D at similar as possible plasma parameters and at different line averaged densities, {bar n}{sub e}. The experimental data represent a set of well diagnosed discharges against which numerical simulations are compared. For the numerical modeling the fluid-code B2.5 coupled to the Monte Carlo neutrals transport code EIRENE is used. Only the combined enhancement of effects, such as geometry, drift terms, neutral conductance, increased radial transport and divertor target composition, explains a significant fraction of the experimentally observed asymmetries of the ion fluxes as a function of {bar n}{sub e} to the inner and outer target plates in ASDEX Upgrade. The relative importance of the mechanisms leading to detachment are different in DIII-D and ASDEX Upgrade.

  10. Ovarian aging and menopause: current theories, hypotheses, and research models.

    Science.gov (United States)

    Wu, Julie M; Zelinski, Mary B; Ingram, Donald K; Ottinger, Mary Ann

    2005-12-01

    Aging of the reproductive system has been studied in numerous vertebrate species. Although there are wide variations in reproductive strategies and hormone cycle components, many of the fundamental changes that occur during aging are similar. Evolutionary hypotheses attempt to explain why menopause occurs, whereas cellular hypotheses attempt to explain how it occurs. It is commonly believed that a disruption in the hypothalamic-pituitary-gonadal axis is responsible for the onset of menopause. Data exist to demonstrate that the first signs of menopause occur at the level of the brain or the ovary. Thus, finding an appropriate and representative animal model is especially important for the advancement of menopause research. In primates, there is a gradual decline in the function of the hypothalamic-pituitary-gonadal (HPG) axis ultimately resulting in irregularities in menstrual cycles and increasingly sporadic incidence of ovulation. Rodents also exhibit a progressive deterioration in HPG axis function; however, they also experience a period of constant estrus accompanied by intermittent ovulations, reduced progesterone levels, and elevated circulating estradiol levels. It is remarkable to observe that females of other classes also demonstrate deterioration in HPG axis function and ovarian failure. Comparisons of aging in various taxa provide insight into fundamental biological mechanisms of aging that could underlie reproductive decline.

  11. The role of tourism public-private partnerships in regional development: a conceptual model proposal

    Directory of Open Access Journals (Sweden)

    Mário Franco

    Full Text Available Tourism is characterized as being a sector that stands out as one of the business activities with the greatest potential for worldwide expansion, and as an engine for economic growth. If at the national level, the appeal of tourism is significant, on the local level this sector presents itself as an essential tool in regional development, as a means to avoid regional desertification and stagnation, stimulating the potential of more undeveloped regions. In such a competitive sector as tourism, companies should develop synergies and achieve competitive advantage. In this context, public-private partnerships play an important role in regional development. The aim of this paper is to present a theoretical context that combines different concepts and elements to explain and understand the public-private partnership phenomenon in tourism. A conceptual model of the role of public-private partnerships will be proposed in order to contribute to successful regional development.

  12. Computational Approaches to Modeling Artificial Emotion -– An overview of the Proposed Solutions

    Directory of Open Access Journals (Sweden)

    Zdzislaw eKOWALCZUK

    2016-04-01

    Full Text Available Cybernetic approach to modeling artificial emotion through the use of different theories of psychology is considered in this paper, presenting a review of twelve proposed solutions: ActAffAct, FLAME, EMA, ParleE, FearNot!, FAtiMA, WASABI, Cathexis, KARO, MAMID, FCM, and xEmotion. The main motivation for this study is founded on the hypothesis that emotions can play a definite utility role of scheduling variables in the construction of intelligent autonomous systems, agents and mobile robots. In this review we also include an innovative and panoptical, comprehensive system, referred to as the Intelligent System of Decision-making (ISD, which has been employed in practical applications of various autonomous units, and which applies as its part the xEmotion, taking into consideration the personal aspects of emotions, affects (short term emotions and mood (principally, long term emotions.

  13. An integrated ethical approach to bioethical decision-making: A proposed model for ministers

    Directory of Open Access Journals (Sweden)

    Magdalena C. de Lange

    2012-09-01

    Full Text Available This article outlined a model for guidance in ‘doing’ bioethics in a Reformed context. The proposed model suggested that in order to arrive at responsible ethical decisions, one must refer to both contextual elements and theory. The theoretical grounding for this model was based on the integration of a deontological and virtue ethics approach, arguing that virtue enables persons to know and desire the right moral ends and motivates them to carry out appropriate action toward achieving these ends. An integrative model opens up the possibility whereby bioethics as a systematic tool provides the individual decision-maker with the critical-reflective skills and justification for the ultimate choice that is lacking in the general decision-making processes. This could lead to clearer thinking and increased confidence in the justification of decisions within the Reformed tradition. The proposed hermeneutical perspective on ethical decision-making represents a shift in views about the nature of knowledge and the process of how we come to know. The key to this hermeneutical approach is to acknowledge the dialectic between the universal and the subjectivity of human relations. Working in specific religious communities, one needs to take cognisance of the fact that knowledge is situated in the context of human relationships in which the interpreter participates when articulating the meaning of bioethical experiences. Another aspect that is anticipated lies in the realisation that people struggling with bioethical dilemmas should not be viewed as isolated individuals, but as members of a broader faith community.‘n Geïntegreerde etiese benadering tot bioetiese besluitneming: Voorgestelde model vir predikante. Hierdie artikel het ‘n model geskets wat moontlike riglyne aantoon vir die  beoefening  van  bioetiek  binne  ‘n  Gereformeerde  konteks.  Die  voorgestelde  model argumenteer dat verwysing na beide kontekstuele elemente en teorie

  14. Simulation modeling of the impact of proposed new simultaneous liver and kidney transplantation policies.

    Science.gov (United States)

    Chang, Yaojen; Gallon, Lorenzo; Shetty, Kirti; Chang, Yuchia; Jay, Colleen; Levitsky, Josh; Ho, Bing; Baker, Talia; Ladner, Daniela; Friedewald, John; Abecassis, Michael; Hazen, Gordon; Skaro, Anton I

    2015-02-01

    Increasing use of kidney grafts for simultaneous liver and kidney (SLK) transplants is causing concern about the most effective utilization of scarce kidney graft resources. This study evaluated the impact of implementing the proposed United Network for Organ Sharing SLK transplant policy on outcomes for end-stage liver disease (ESLD) and end-stage renal disease (ESRD) patients awaiting transplant. A Markov model was constructed to simulate a hypothetical cohort of ESLD patients over a 30-year time horizon starting from age 50. The model applies the different criteria being considered in the United Network for Organ Sharing policy and tallies outcomes, including numbers of procedures and life years after liver transplant alone (LTA) or SLK transplant. When 1-week pretransplant dialysis duration is required, the numbers of SLK transplants and LTAs would be 648 and 9,065, respectively. If the pretransplant dialysis duration is extended to 12 weeks, there would be 240 SLK transplants and 9,426 LTAs. This change results in a decrease of 6,483 life years among SLK transplant recipients and an increase of 4,971 life years among LTA recipients. However, by increasing the dialysis duration to 12 weeks from 1 week, 408 kidney grafts would be released to the kidney waitlist because of the decline in SLK transplants; this yields 796 additional life years gained among ESRD patients. Implementation of the proposed SLK transplant policy could restore access to kidney transplants for patients with ESRD albeit at the detriment of patients with ESLD and renal impairment.

  15. Growth instability due to lattice-induced topological currents in limited-mobility epitaxial growth models.

    Science.gov (United States)

    Kanjanaput, Wittawat; Limkumnerd, Surachate; Chatraphorn, Patcha

    2010-10-01

    The energetically driven Ehrlich-Schwoebel barrier had been generally accepted as the primary cause of the growth instability in the form of quasiregular moundlike structures observed on the surface of thin film grown via molecular-beam epitaxy (MBE) technique. Recently the second mechanism of mound formation was proposed in terms of a topologically induced flux of particles originating from the line tension of the step edges which form the contour lines around a mound. Through large-scale simulations of MBE growth on a variety of crystalline lattice planes using limited-mobility, solid-on-solid models introduced by Wolf-Villain and Das Sarma-Tamborenea in 2+1 dimensions, we show that there exists a topological uphill particle current with strong dependence on specific lattice crystalline structure. Without any energetically induced barriers, our simulations produce spectacular mounds very similar, in some cases, to what have been observed in many recent MBE experiments. On a lattice where these currents cease to exist, the surface appears to be scale invariant, statistically rough as predicted by the conventional continuum growth equation.

  16. Is it appropriate to model turbidity currents with the three-equation model?

    Science.gov (United States)

    Hu, Peng; Pähtz, Thomas; He, Zhiguo

    2015-07-01

    The three-equation model (TEM) was developed in the 1980s to model turbidity currents (TCs) and has been widely used ever since. However, its physical justification was questioned because self-accelerating TCs simulated with the steady TEM seemed to violate the turbulent kinetic energy balance. This violation was considered as a result of very strong sediment erosion that consumes more turbulent kinetic energy than is produced. To confine bed erosion and thus remedy this issue, the four-equation model (FEM) was introduced by assuming a proportionality between the bed shear stress and the turbulent kinetic energy. Here we analytically proof that self-accelerating TCs simulated with the original steady TEM actually never violate the turbulent kinetic energy balance, provided that the bed drag coefficient is not unrealistically low. We find that stronger bed erosion, surprisingly, leads to more production of turbulent kinetic energy due to conversion of potential energy of eroded material into kinetic energy of the current. Furthermore, we analytically show that, for asymptotically supercritical flow conditions, the original steady TEM always produces self-accelerating TCs if the upstream boundary conditions ("ignition" values) are chosen appropriately, while it never does so for asymptotically subcritical flow conditions. We numerically show that our novel method to obtain the ignition values even works for Richardson numbers very near to unity. Our study also includes a comparison of the TEM and FEM closures for the bed shear stress to simulation data of a coupled Large Eddy and Discrete Element Model of sediment transport in water, which suggests that the TEM closure might be more realistic than the FEM closure.

  17. Space-charge-controlled field emission model of current conduction through Al2O3 films

    Science.gov (United States)

    Hiraiwa, Atsushi; Matsumura, Daisuke; Kawarada, Hiroshi

    2016-02-01

    This study proposes a model for current conduction in metal-insulator-semiconductor (MIS) capacitors, assuming the presence of two sheets of charge in the insulator, and derives analytical formulae of field emission (FE) currents under both negative and positive bias. Since it is affected by the space charge in the insulator, this particular FE differs from the conventional FE and is accordingly named the space-charge-controlled (SCC) FE. The gate insulator of this study was a stack of atomic-layer-deposition Al2O3 and underlying chemical SiO2 formed on Si substrates. The current-voltage (I-V) characteristics simulated using the SCC-FE formulae quantitatively reproduced the experimental results obtained by measuring Au- and Al-gated Al2O3/SiO2 MIS capacitors under both biases. The two sheets of charge in the Al2O3 films were estimated to be positive and located at a depth of greater than 4 nm from the Al2O3/SiO2 interface and less than 2 nm from the gate. The density of the former is approximately 1 × 1013 cm-2 in units of electronic charge, regardless of the type of capacitor. The latter forms a sheet of dipoles together with image charges in the gate and hence causes potential jumps of 0.4 V and 1.1 V in the Au- and Al-gated capacitors, respectively. Within a margin of error, this sheet of dipoles is ideally located at the gate/Al2O3 interface and effectively reduces the work function of the gate by the magnitude of the potential jumps mentioned above. These facts indicate that the currents in the Al2O3/SiO2 MIS capacitors are enhanced as compared to those in ideal capacitors and that the currents in the Al-gated capacitors under negative bias (electron emission from the gate) are more markedly enhanced than those in the Au-gated capacitors. The larger number of gate-side dipoles in the Al-gated capacitors is possibly caused by the reaction between the Al and Al2O3, and therefore gate materials that do not react with underlying gate insulators should be chosen

  18. Proposal of a Novel Approach to Developing Material Models for Micro-scale Composites Based on Testing and Modeling of Macro-scale Composites

    Energy Technology Data Exchange (ETDEWEB)

    Siranosian, Antranik Antonio [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Schembri, Philip Edward [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Luscher, Darby Jon [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-04-20

    The Los Alamos National Laboratory's Weapon Systems Engineering division's Advanced Engineering Analysis group employs material constitutive models of composites for use in simulations of components and assemblies of interest. Experimental characterization, modeling and prediction of the macro-scale (i.e. continuum) behaviors of these composite materials is generally difficult because they exhibit nonlinear behaviors on the meso- (e.g. micro-) and macro-scales. Furthermore, it can be difficult to measure and model the mechanical responses of the individual constituents and constituent interactions in the composites of interest. Current efforts to model such composite materials rely on semi-empirical models in which meso-scale properties are inferred from continuum level testing and modeling. The proposed approach involves removing the difficulties of interrogating and characterizing micro-scale behaviors by scaling-up the problem to work with macro-scale composites, with the intention of developing testing and modeling capabilities that will be applicable to the mesoscale. This approach assumes that the physical mechanisms governing the responses of the composites on the meso-scale are reproducible on the macro-scale. Working on the macro-scale simplifies the quantification of composite constituents and constituent interactions so that efforts can be focused on developing material models and the testing techniques needed for calibration and validation. Other benefits to working with macro-scale composites include the ability to engineer and manufacture—potentially using additive manufacturing techniques—composites that will support the application of advanced measurement techniques such as digital volume correlation and three-dimensional computed tomography imaging, which would aid in observing and quantifying complex behaviors that are exhibited in the macro-scale composites of interest. Ultimately, the goal of this new approach is to develop a meso

  19. Group Offending in Mass Atrocities: Proposing a Group Violence Strategies Model for International Crimes

    Directory of Open Access Journals (Sweden)

    Regina Elisabeth Rauxloh

    2016-12-01

    Full Text Available Most research in mass atrocities, especially genocide, is conducted at the macro level exploring how mass violence is instigated, planned and orchestrated at the level of the state. This paper on the other hand suggests that more research of the individual perpetrator is needed to complement the understanding of mass atrocities. The author develops therefore a new model, the group violence strategies model. This model combines various traditional criminological models of group offending and proposes a three stage analysis, looking at the individual aggressor, the actions within the offender group and the actions between offender group and victim group to understand better the phenomenon that ordinary people commit unspeakable crimes. La mayor parte de las investigaciones sobre atrocidades en masa, especialmente genocidio, se desarrollan a nivel macro, analizando cómo se instiga, planea y orquestra la violencia de masas a nivel de estado. Este artículo, sin embargo, sugiere que es necesaria una mayor investigación del criminal individual, para complementar la comprensión de las atrocidades en masa. Así, se desarrolla un nuevo modelo, el modelo de estrategias de violencia en grupo. Este modelo combina diversos modelos criminológicos tradicionales de violencia en grupo y propone tres etapas de análisis, mirando al agresor individual, las acciones dentro del grupo criminal y las acciones entre el grupo criminal y el grupo de víctimas, para entender mejor este fenómeno por el que personas corrientes cometen crímenes atroces. DOWNLOAD THIS PAPER FROM SSRN: https://ssrn.com/abstract=2875712

  20. A proposed study on the transplacental transport of parabens in the human placental perfusion model.

    Science.gov (United States)

    Mathiesen, Line; Zuri, Giuseppina; Andersen, Maria H; Knudsen, Lisbeth E

    2013-12-01

    Human exposure to parabens as a preservative used in personal care products is of increasing concern, as there is evidence from in vivo and in vitro studies of hormone disruption in association with exposure to parabens. Transport across the placenta could be critical for risk assessment, but the available data are sparse. The aim is to develop a method for estimating fetal exposure, via the placenta, to the most commonly-used parabens, by using a human placental perfusion model. The use of human tissue is vital for determining human fetal exposure, because animal studies are of little relevance, since the placenta exhibits significant interspecies variation. An HPLC model is currently being established to simultaneously quantify four different parabens, namely, methylparaben, ethylparaben, propylparaben and butylparaben, and their main metabolite, p-hydroxybenzoic acid. With this model, we aim to determine the transport kinetics of these parabens across the human placenta, and to investigate placental metabolism, including differences in transport due to molecular characteristics. This will facilitate assessment of the risks associated with the use of paraben-containing products during pregnancy. 2013 FRAME.

  1. Shallow water models as tool for tsunami current predictions in ports and harbors. Validation with Tohoku 2011 field data

    Science.gov (United States)

    Gonzalez Vida, J. M., Sr.; Macias Sanchez, J.; Castro, M. J.; Ortega, S.

    2015-12-01

    Model ability to compute and predict tsunami flow velocities is of importance in risk assessment and hazard mitigation. Substantial damage can be produced by high velocity flows, particularly in harbors and bays, even when the wave height is small. Besides, an accurate simulation of tsunami flow velocities and accelerations is fundamental for advancing in the study of tsunami sediment transport. These considerations made the National Tsunami Hazard Mitigation Program (NTHMP) proposing a benchmark exercise focused on modeling and simulating tsunami currents. Until recently, few direct measurements of tsunami velocities were available to compare and to validate model results. After Tohoku 2011 many current meters measurement were made, mainly in harbors and channels. In this work we present a part of the contribution made by the EDANYA group from the University of Malaga to the NTHMP workshop organized at Portland (USA), 9-10 of February 2015. We have selected three out of the five proposed benchmark problems. Two of them consist in real observed data from the Tohoku 2011 event, one at Hilo Habour (Hawaii) and the other at Tauranga Bay (New Zealand). The third one consists in laboratory experimental data for the inundation of Seaside City in Oregon. For this model validation the Tsunami-HySEA model, developed by EDANYA group, was used. The overall conclusion that we could extract from this validation exercise was that the Tsunami-HySEA model performed well in all benchmark problems proposed. The greater spatial variability in tsunami velocity than wave height makes it more difficult its precise numerical representation. The larger variability in velocities is likely a result of the behaviour of the flow as it is channelized and as it flows around bathymetric highs and structures. In the other hand wave height do not respond as strongly to chanelized flow as current velocity.

  2. Analysis of Fast-Scale Bifurcation in Peak Current Controlled Buck-Boost Inverter Based on Unified Averaged Model

    Science.gov (United States)

    Zhang, Hao; Dong, Shuai; Guan, Weimin; Liu, Ye

    In this paper, a unified averaged modeling method is proposed to investigate the fast-scale period-doubling bifurcation of a full-bridge integrated buck-boost inverter with peak current control. In order to increase the resolution of the conventional classic averaged model to half the switching frequency, sample-and-hold effect of inductor current is absorbed into the averaged model, i.e. the proposed unified averaged model can capture the high-frequency dynamical characteristics of the buck-boost inverter, which is both an extension and a modification of conventional averaged model. Based on the unified mode, fast-scale bifurcation is identified, and the corresponding bifurcation point is predicted with the help of the locus movement of all the poles, and their underlying mechanisms are revealed. Detailed analysis shows that the occurrence of high-frequency oscillation means fast-scale bifurcation, while the occurrence of low-frequency oscillation leads to slow-scale bifurcation. Finally, it is demonstrated that the unified averaged model can provide not only a general method to investigate both the slow- and fast-scale bifurcations in a unified framework but also a quite straightforward design-oriented method which can be directly applicable.

  3. A proposed model of factors influencing hydrogen fuel cell vehicle acceptance

    Science.gov (United States)

    Imanina, N. H. Noor; Kwe Lu, Tan; Fadhilah, A. R.

    2016-03-01

    Issues such as environmental problem and energy insecurity keep worsening as a result of energy use from household to huge industries including automotive industry. Recently, a new type of zero emission vehicle, hydrogen fuel cell vehicle (HFCV) has received attention. Although there are argues on the feasibility of hydrogen as the future fuel, there is another important issue, which is the acceptance of HFCV. The study of technology acceptance in the early stage is a vital key for a successful introduction and penetration of a technology. This paper proposes a model of factors influencing green vehicle acceptance, specifically HFCV. This model is built base on two technology acceptance theories and other empirical studies of vehicle acceptance. It aims to provide a base for finding the key factors influencing new sustainable energy fuelled vehicle, HFCV acceptance which is achieved by explaining intention to accept HFCV. Intention is influenced by attitude, subjective norm and perceived behavioural control from Theory of Planned Behaviour and personal norm from Norm Activation Theory. In the framework, attitude is influenced by perceptions of benefits and risks, and social trust. Perceived behavioural control is influenced by government interventions. Personal norm is influenced by outcome efficacy and problem awareness.

  4. ACCREDITATION OF DEN TAL CARE SERVICES – A PROPOSAL FOR A LOG ICAL MODEL

    Directory of Open Access Journals (Sweden)

    Rosangela Simonelli Gavi

    2013-05-01

    Full Text Available The National Accreditation Organization has published the Brazilian Manual of Accreditation forHealthcareServiceProvidersin 2010and thismanual provides the guidelines for the developmentof an accreditation process for healthcare providers; however, it does not provide standards for adental accreditation process. The aim of this study was to conceptualize the accreditation of dentalcare services and present a logical model that can anchor the development of a tool for accreditationof dental care services in Brazil. The Brazilian Manual of Accreditationsupported by thehealthcare services of the National Accreditation Organization (ONA provides guidelines for thedevelopment of the accreditation process in health care institutions; however, it does not providestandards for the dental accreditation process. The model proposed has three foci of analysis, sixdescribed sections and thirteen described subsections, all considering relevant aspects concerninghigh quality providers of dental care services.It waspossible to conceptualizethe accreditationandpresent a logicalmodel thatwas designed for the accreditation of UnitsProvidingDental CareServices (UPDCS-(UPSAO in Portuguese and ComplexesProvidingDental Care Services(CPDCS-(CPSAO in Portuguese

  5. A Proposal of Ecologic Taxes Based on Thermo-Economic Performance of Heat Engine Models

    Directory of Open Access Journals (Sweden)

    Fernando Angulo-Brown

    2009-11-01

    Full Text Available Within the context of Finite-Time Thermodynamics (FTT a simplified thermal power plant model (the so-called Novikov engine is analyzed under economical criteria by means of the concepts of profit function and the costs involved in the performance of the power plant. In this study, two different heat transfer laws are used, the so called Newton’s law of cooling and the Dulong-Petit’s law of cooling. Two FTT optimization criteria for the performance analysis are used: the maximum power regime (MP and the so-called ecological criterion. This last criterion leads the engine model towards a mode of performance that appreciably diminishes the engine’s wasted energy. In this work, it is shown that the energy-unit price produced under maximum power conditions is cheaper than that produced under maximum ecological (ME conditions. This was accomplished by using a typical definition of profits function stemming from economics. The MP-regime produces considerably more wasted energy toward the environment, thus the MP energy-unit price is subsidized by nature. Due to this fact, an ecological tax is proposed, which could be a certain function of the price difference between the MP and ME modes of power production.

  6. A proposal of ecologic taxes based on thermo-economic performance of heat engine models

    Energy Technology Data Exchange (ETDEWEB)

    Barranco-Jimenez, M. A. [Departamento de Ciencias Basicas, Escuela Superior de Computo del IPN, Av. Miguel Bernal Esq. Juan de Dios Batiz U.P. Zacatenco CP 07738, D.F. (Mexico); Ramos-Gayosso, I. [Unidad de Administracion de Riesgos, Banco de Mexico, 5 de Mayo, Centro, D.F. (Mexico); Rosales, M. A. [Departamento de Fisica y Matematicas, Universidad de las Americas, Puebla Exhacienda Sta. Catarina Martir, Cholula 72820, Puebla (Mexico); Angulo-Brown, F. [Departamento de Fisica, Escuela Superior de Fisica y Matematicas del IPN, Edif. 9 U.P. Zacatenco CP 07738, D.F. (Mexico)

    2009-07-01

    Within the context of Finite-Time Thermodynamics (FTT) a simplified thermal power plant model (the so-called Novikov engine) is analyzed under economical criteria by means of the concepts of profit function and the costs involved in the performance of the power plant. In this study, two different heat transfer laws are used, the so called Newton's law of cooling and the Dulong-Petit's law of cooling. Two FTT optimization criteria for the performance analysis are used: the maximum power regime (MP) and the so-called ecological criterion. This last criterion leads the engine model towards a mode of performance that appreciably diminishes the engine's wasted energy. In this work, it is shown that the energy-unit price produced under maximum power conditions is cheaper than that produced under maximum ecological (ME) conditions. This was accomplished by using a typical definition of profits function stemming from economics. The MP-regime produces considerably more wasted energy toward the environment, thus the MP energy-unit price is subsidized by nature. Due to this fact, an ecological tax is proposed, which could be a certain function of the price difference between the MP and ME modes of power production. (author)

  7. A proposed monitoring and evaluation curriculum based on a model that institutionalises monitoring and evaluation

    Directory of Open Access Journals (Sweden)

    Kambidima Wotela

    2017-04-01

    Full Text Available Background: African politicians, bureaucrats and technocrats have thrown their weight in support of monitoring and evaluation (M&E. This weight has compelled training institutions to add M&E to their offerings. Most often at the end of these training programmes, attendees know what they have learnt but seem not to internalise it and, worse, they hardly ever put their newly acquired knowledge into practice. This allegation has led to what we term ‘monitoring and evaluation training hopping’ where participants move from one training to another hoping that they will eventually fully comprehend the skill and apply it to their work. This rarely happens and as such participants often blame themselves and yet the problem is with the training institutions that are teaching the middle-third tier (how to monitor and evaluate as well as the bottom-third tier (data and information management. However, the top-third tier that links M&E to ‘the what’ and ‘the how’ as well as ‘the why’ in the development intervention and public policy landscape is missing.Objectives: To propose a M&E curriculum that institutionalises M&E within implementation and management of development interventions.Method: We use systems thinking to derive the key themes of our discussion and then apply summative thematic content analysis to interrogate M&E and related literature. Firstly, we present and describe a model that situates M&E within development and public policy. This model ‘idealises or realises’ an institutionalised M&E by systematically linking the contextual as well as key terms prominent in established descriptions of M&E. Secondly, we briefly describe M&E from a systems thinking approach by pointing out its components, processes, established facts, as well as issues and debates. Lastly, we use this model and the systems thinking description of M&E to propose an institutionalised M&E curriculum.Results: Our results show that for an explicit

  8. Ground-state entanglement in a three-spin transverse Ising model with energy current

    Institute of Scientific and Technical Information of China (English)

    Zhang Yong; Liu Dan; Long Gui-Lu

    2007-01-01

    The ground-state entanglement associated with a three-spin transverse Ising model is studied. By introducing an energy current into the system, a quantum phase transition to energy-current phase may be presented with the variation of external magnetic field; and the ground-state entanglement varies suddenly at the critical point of quantum phase transition. In our model, the introduction of energy current makes the entanglement between any two qubits become maximally robust.

  9. Modeling studies of the coastal/littoral current system off Southern Australia

    OpenAIRE

    Miller, Henry A.

    2006-01-01

    Both theoretical and numerical modeling studies of the current system off western and southern Australia are conducted to characterize the features of the current system, their temporal variability, and their impact on the sound speed structure. The theoretical study examines why boundary current separation occurs off Cape Leeuwin creating an area of enhanced eddy generation. It is shown that the beta effect, vortex stretching, and streamline curvature all act to decelerate the current a...

  10. Automatic parameter extraction technique for gate leakage current modeling in double gate MOSFET

    Science.gov (United States)

    Darbandy, Ghader; Gneiting, Thomas; Alius, Heidrun; Alvarado, Joaquín; Cerdeira, Antonio; Iñiguez, Benjamin

    2013-11-01

    Direct Tunneling (DT) and Trap Assisted Tunneling (TAT) gate leakage current parameters have been extracted and verified considering automatic parameter extraction approach. The industry standard package IC-CAP is used to extract our leakage current model parameters. The model is coded in Verilog-A and the comparison between the model and measured data allows to obtain the model parameter values and parameters correlations/relations. The model and parameter extraction techniques have been used to study the impact of parameters in the gate leakage current based on the extracted parameter values. It is shown that the gate leakage current depends on the interfacial barrier height more strongly than the barrier height of the dielectric layer. There is almost the same scenario with respect to the carrier effective masses into the interfacial layer and the dielectric layer. The comparison between the simulated results and available measured gate leakage current transistor characteristics of Trigate MOSFETs shows good agreement.

  11. Voltage-clamp predictions by gompertz kinetics model relating squid-axon Na+-gating and ionic currents.

    Science.gov (United States)

    Easton, Dexter M

    2005-10-01

    Gompertz kinetics is a simple, realistic, accurate, and computationally parsimonious alternative for prediction of macroscopic changes in Na+ conductance during voltage clamp. Conductance delay and time course depend on initial amplitudes and decay rates of surrogates for the macroscopic gating currents. The model is tested by the fit to published data of other authors. The proposed physical basis for the model is that membrane potential perturbation triggers motion of charged "gating" components of the axon membrane at rapid (activating) and at slow (inactivating) rates. The resulting distortion increases and more slowly diminishes the probability that conduction channels will be open.

  12. Dynamics of turbulent western-boundary currents at low latitude in a shallow-water model

    Science.gov (United States)

    Akuetevi, C. Q. C.; Wirth, A.

    2015-06-01

    The dynamics of low latitude turbulent western-boundary currents (WBCs) crossing the Equator are considered using numerical results from integrations of a reduced-gravity shallow-water model. For viscosity values of 1000 m2 s-1 and greater, the boundary layer dynamics compares well to the analytical Munk-layer solution. When the viscosity is reduced, the boundary layer becomes turbulent and coherent structures in the form of anticyclonic eddies, bursts (violent detachments of the viscous sub-layer, VSL) and dipoles appear. Three distinct boundary layers emerge, the VSL, the advective boundary layer and the extended boundary layer. The first is characterized by a dominant vorticity balance between the viscous transport and the advective transport of vorticity; the second by a balance between the advection of planetary vorticity and the advective transport of relative vorticity. The extended boundary layer is the area to which turbulent motion from the boundary extends. The scaling of the three boundary layer thicknesses with viscosity is evaluated. Characteristic scales of the dynamics and dissipation are determined. A pragmatic approach to determine the eddy viscosity diagnostically for coarse-resolution numerical models is proposed.

  13. Modeling Water and Carbon Budgets in Current and Future Agricultural Land Use

    Science.gov (United States)

    Drewniak, B.; Song, J.; Prell, J.; Kotamarthi, R.; Jacob, R.

    2008-12-01

    Biofuels are a key component of renewable energy mix proposed as a substitute to fossil fuels. Biofuels are suggested as both economical and having potential for reducing atmospheric emissions of carbon from the transportation sector, by building up soil carbon levels when planted on lands where these levels have been reduced by intensive tillage. The purpose of this research is to develop a carbon-nitrogen based crop module (CNC) for the community land model (CLM) and to improve the characterization of the below and above ground carbon sequestration for bioenergy crops. The CNC simulates planting, growing, maturing and harvesting stages for three major crops: maize, soybean and wheat. In addition, dynamic root module is implemented to simulate fine root distribution and development based on relative availability of soil water and nitrogen in the root zone. Coupled CLM-CNC models is used to study crop yields, geographic locations for bioenergy crop production and soil carbon changes. Bioenergy crop cultivation is based on current crop cultivation and future land use change dataset. Soil carbon change has been simulated based on carbon input to the soil from the leaf, stem and root, and carbon emission from soil carbon decomposition. Simulated water and carbon fluxes have been compared with field observations and soil carbon content has been examined under different harvest practices.

  14. Dynamics of turbulent western boundary currents at low latitude in a shallow water model

    Directory of Open Access Journals (Sweden)

    C. Q. C. Akuetevi

    2014-11-01

    Full Text Available The dynamics of low latitude turbulent western boundary currents crossing the equator is considered using numerical results from integrations of a reduced gravity shallow-water model. For viscosity values of 1000 m2 s−1 and more, the boundary layer dynamics compares well to the analytical Munk-layer solution. When the viscosity is reduced, the boundary layer becomes turbulent and coherent structures in form of anticyclonic eddies, bursts (violent detachments of the viscous sub-layer and dipoles appear. Three distinct boundary layers emerge, the viscous sub-layer, the advective boundary layer and the extended boundary layer. The first is characterized by a dominant vorticity balance between the viscous transport and the advective transport of vorticity. The second by a balance between the advection of planetary vorticity and the advective transport of relative vorticity. The extended boundary layer is the area to which turbulent motion from the boundary extends. The scaling of the three boundary layer thicknesses with viscosity is evaluated. Characteristic scales of the dynamics and dissipation are determined. A pragmatic approach to determine the eddy viscosity diagnostically for coarse resolution numerical models is proposed.

  15. Dynamics of turbulent western boundary currents at low latitude in a shallow water model

    Directory of Open Access Journals (Sweden)

    C. Q. C. Akuetevi

    2014-03-01

    Full Text Available The dynamics of low latitude turbulent western boundary currents, subject to two different types of idealized wind forcing, Monsoon Wind and Trade Wind, is considered using numerical results from integrations of a reduced gravity shallow-water model. For viscosity values of 1000 m2 s−1 and above, the boundary layer dynamics compares well to the analytical solutions of the Munk-layer and the inertial-layer, derived from quasigeostrophic theory. Modifications due to variations in the layer thickness (vortex stretching are only important close to the boundary. When the viscosity is reduced the boundary layer becomes turbulent and coherent structures in form of anticyclonic eddies, bursts (violent detachments of the viscous sub-layer and dipoles appear. Three distinct boundary layers emerge, the viscous sub-layer, the advective boundary layer and the extended boundary layer. The first is characterized by a dominant vorticity balance between the viscous transport and the advective transport of vorticity. The second by a balance between the advection of planetary vorticity and the advective transport of relative vorticity. The extended boundary layer is the area to which turbulent motion from the boundary extends. The scaling of the three boundary layer thicknesses with viscosity is evaluated. A pragmatic approach to determine the eddy viscosity diagnostically for coarse resolution numerical models is proposed.

  16. Analytical model for Transient Current Technique (TCT) signal prediction and analysis for thin interface characterization

    Science.gov (United States)

    Bronuzzi, J.; Mapelli, A.; Sallese, J. M.

    2016-12-01

    A silicon wafer bonding technique has been recently proposed for the fabrication of monolithic silicon radiation detectors. This new process would enable direct bonding of a read-out electronic chip wafer on a highly resistive silicon substrate wafer. Therefore, monolithic silicon detectors could be fabricated in this way which would allow the free choice of electronic chips and high resistive silicon bulk, even from different providers. Moreover, a monolithic detector with a high resistive bulk would also be available. Electrical properties of the bonded interface are then critical for this application. Indeed, mobile charges generated by radiation inside the bonded bulk are expected to transit through the interface to be collected by the read-out electronics. In order to characterize this interface, the concept of Transient Current Technique (TCT) has been explored by means of numerical simulations combined with a physics based analytical model. In this work, the analytical model giving insight into the physics behind the TCT dependence upon interface traps is validated using both TCAD simulations and experimental measurements.

  17. Evaluating the osseointegration of nanostructured titanium implants in animal models: Current experimental methods and perspectives (Review).

    Science.gov (United States)

    Babuska, Vaclav; Moztarzadeh, Omid; Kubikova, Tereza; Moztarzadeh, Amin; Hrusak, Daniel; Tonar, Zbynek

    2016-09-15

    The aim of this paper is to review the experimental methods currently being used to evaluate the osseointegration of nanostructured titanium implants using animal models. The material modifications are linked to the biocompatibility of various types of oral implants, such as laser-treated, acid-etched, plasma-coated, and sand-blasted surface modifications. The types of implants are reviewed according to their implantation site (endoosseous, subperiosteal, and transosseous implants). The animal species and target bones used in experimental implantology are carefully compared in terms of the ratio of compact to spongy bone. The surgical technique in animal experiments is briefly described, and all phases of the histological evaluation of osseointegration are described in detail, including harvesting tissue samples, processing undemineralized ground sections, and qualitative and quantitative histological assessment of the bone-implant interface. The results of histological staining methods used in implantology are illustrated and compared. A standardized and reproducible technique for stereological quantification of bone-implant contact is proposed and demonstrated. In conclusion, histological evaluation of the experimental osseointegration of dental implants requires careful selection of the experimental animals, bones, and implantation sites. It is also advisable to use larger animal models and older animals with a slower growth rate rather than small or growing experimental animals. Bones with a similar ratio of compact to spongy bone, such as the human maxilla and mandible, are preferred. A number of practical recommendations for the experimental procedures, harvesting of samples, tissue processing, and quantitative histological evaluations are provided.

  18. A Proposed Model for Assessing Defendant Competence to Self-Represent.

    Science.gov (United States)

    White, Mitzi M S; Gutheil, Thomas G

    2016-12-01

    The increasing number of criminal defendants who are choosing to self-represent poses special challenges for legal systems with regard to the types of limits that should be placed on a defendant's basic human right to defend himself without the assistance of counsel. While courts strive to respect the dignity and autonomy of the defendant that are encompassed in this right, they also want to ensure that justice is delivered and the dignity of the courtroom is maintained. The Supreme Court of the United States, in its opinion in Indiana v. Edwards (2008), held that while the right to self-represent recognized in Faretta v. California (1975) remains, states and trial judges can place limits on a defendant's right to self-representation when a defendant lacks the mental capacities needed to prepare and conduct an adequate defense. Following the court's lead, we first examine the types and range of tasks that a defendant who chooses to self-represent must perform. Based on this analysis, we propose a five-part model that forensic practitioners can use as a conceptual framework for assessing whether a defendant has deficits that would affect his competence to perform critical self-representation tasks. The five areas that the model recommends practitioners assess are whether a defendant can engage in goal-directed behaviors, has sufficient communication skills, can engage in constructive social intercourse, can control his emotions in an adversarial arena, and has the cognitive abilities needed to argue his case adequately. It is recommended that practitioners use the model in their testimony to provide the trier of fact with a comprehensive report of the areas in which a defendant has deficits that will prevent him from protecting his interests in receiving a fair and equitable trial. © 2016 American Academy of Psychiatry and the Law.

  19. Proposed best modeling practices for assessing the effects of ecosystem restoration on fish

    Science.gov (United States)

    Rose, Kenneth A; Sable, Shaye; DeAngelis, Donald L.; Yurek, Simeon; Trexler, Joel C.; Graf, William L.; Reed, Denise J.

    2015-01-01

    Large-scale aquatic ecosystem restoration is increasing and is often controversial because of the economic costs involved, with the focus of the controversies gravitating to the modeling of fish responses. We present a scheme for best practices in selecting, implementing, interpreting, and reporting of fish modeling designed to assess the effects of restoration actions on fish populations and aquatic food webs. Previous best practice schemes that tended to be more general are summarized, and they form the foundation for our scheme that is specifically tailored for fish and restoration. We then present a 31-step scheme, with supporting text and narrative for each step, which goes from understanding how the results will be used through post-auditing to ensure the approach is used effectively in subsequent applications. We also describe 13 concepts that need to be considered in parallel to these best practice steps. Examples of these concepts include: life cycles and strategies; variability and uncertainty; nonequilibrium theory; biological, temporal, and spatial scaling; explicit versus implicit representation of processes; and model validation. These concepts are often not considered or not explicitly stated and casual treatment of them leads to mis-communication and mis-understandings, which in turn, often underlie the resulting controversies. We illustrate a subset of these steps, and their associated concepts, using the three case studies of Glen Canyon Dam on the Colorado River, the wetlands of coastal Louisiana, and the Everglades. Use of our proposed scheme will require investment of additional time and effort (and dollars) to be done effectively. We argue that such an investment is well worth it and will more than pay back in the long run in effective and efficient restoration actions and likely avoided controversies and legal proceedings.

  20. Incorporating the user perspective into a proposed model for assessing success of SHS implementations

    Directory of Open Access Journals (Sweden)

    Hans Holtorf

    2015-10-01

    Full Text Available Modern energy can contribute to development in multiple ways while approximately 20% of world's populations do not yet have access to electricity. Solar Home Systems (SHSs consists of a PV module, a charge controller and a battery supply in the range of 100 Wh/d in Sunbelt countries. The question addressed in this paper is how SHS users approach success of their systems and how these user's views can be integrated in to an existing model of success. Information was obtained on the user's approach to their SHSs by participatory observation, interviews with users and by self-observation undertaken by the lead author while residing under SHS electricity supply conditions. It was found that success of SHSs from the users' point of view is related to the ability of these systems to reduce the burdens of supplying energy services to homesteads. SHSs can alleviate some energy supply burdens, and they can improve living conditions by enabling communication on multiple levels and by addressing convenience and safety concerns. However, SHSs do not contribute to the energy services which are indispensable for survival, nor to the thermal energy services required and desired in dwellings of Sunbelt countries. The elements of three of the four components of our previously proposed model of success have been verified and found to be appropriate, namely the user's self-set goals, their importance and SHSs' success factors. The locally appropriate, and scientifically satisfactory, measurement of the level of achievement of self-set goals, the fourth component of our model of success, remains an interesting area for future research.

  1. Creep stability of the proposed AIDA mission target 65803 Didymos: I. Discrete cohesionless granular physics model

    Science.gov (United States)

    Zhang, Yun; Richardson, Derek C.; Barnouin, Olivier S.; Maurel, Clara; Michel, Patrick; Schwartz, Stephen R.; Ballouz, Ronald-Louis; Benner, Lance A. M.; Naidu, Shantanu P.; Li, Junfeng

    2017-09-01

    As the target of the proposed Asteroid Impact & Deflection Assessment (AIDA) mission, the near-Earth binary asteroid 65803 Didymos represents a special class of binary asteroids, those whose primaries are at risk of rotational disruption. To gain a better understanding of these binary systems and to support the AIDA mission, this paper investigates the creep stability of the Didymos primary by representing it as a cohesionless self-gravitating granular aggregate subject to rotational acceleration. To achieve this goal, a soft-sphere discrete element model (SSDEM) capable of simulating granular systems in quasi-static states is implemented and a quasi-static spin-up procedure is carried out. We devise three critical spin limits for the simulated aggregates to indicate their critical states triggered by reshaping and surface shedding, internal structural deformation, and shear failure, respectively. The failure condition and mode, and shear strength of an aggregate can all be inferred from the three critical spin limits. The effects of arrangement and size distribution of constituent particles, bulk density, spin-up path, and interparticle friction are numerically explored. The results show that the shear strength of a spinning self-gravitating aggregate depends strongly on both its internal configuration and material parameters, while its failure mode and mechanism are mainly affected by its internal configuration. Additionally, this study provides some constraints on the possible physical properties of the Didymos primary based on observational data and proposes a plausible formation mechanism for this binary system. With a bulk density consistent with observational uncertainty and close to the maximum density allowed for the asteroid, the Didymos primary in certain configurations can remain geo-statically stable without requiring cohesion.

  2. A self-discharge model of Lithium-Sulfur batteries based on direct shuttle current measurement

    DEFF Research Database (Denmark)

    Knap, Vaclav; Stroe, Daniel Loan; Swierczynski, Maciej Jozef

    2016-01-01

    . A simple but comprehensive mathematical model of the Li-S battery cell self-discharge based on the shuttle current was developed and is presented. The shuttle current values for the model parameterization were obtained from the direct shuttle current measurements. Furthermore, the battery cell depth......-of-discharge values were recomputed in order to account for the influence of the self-discharge and provide a higher accuracy of the model. Finally, the derived model was successfully validated against laboratory experiments at various conditions....

  3. A Galvanostatic Modeling for Preparation of Electrodeposited Nanocrystalline Coatings by Control of Current Density

    Institute of Scientific and Technical Information of China (English)

    Ali Mohammad Rashidi

    2012-01-01

    The correlation between the grain size of electrodeposited coatings and the current densities was modeled by considering galvanostatic conditions. In order to test the model by experimental results, nanocrystalline (NC) nickel samples were deposited at different current densities using a Watts bath. The grain size of the deposits was evaluated by X-ray diffraction (XRD) technique. Model predictions were validated by finding a curve being the best-fit to the experimental results which were gathered from literature for different NC coatings in addition to those data measured in this research for NC nickel coatings. According to our model, the variation of grain size with the reciprocal of the current density follows a power law. A good agreement between the experimental results and model predictions was observed which indicated that the derived analytical model is applicable for producting the nanocrystalline electrodeposits with the desired grain size by controling current density.

  4. Numerical simulation of suspended sediment concentration by 3D coupled wave-current model in the Oujiang River Estuary, China

    Science.gov (United States)

    Xu, Ting; You, Xue-yi

    2017-04-01

    A 3D sediment transport model based on the modified environmental fluid dynamics code (EFDC) and the nearshore waves simulation model (SWAN) is developed to study the change of suspended sediment concentration and bottom shear stress under the actions of pure current and wave-current. After being validated by the field measured data, the proposed sediment transport model is applied in the Oujiang River Estuary, China. The results show that the ratios of both bottom shear stress and suspended sediment concentration of pure current to those of wave-current show a gradually increase from shallow nearshore water to deep open sea. The results also show that the proportion of wave contributions on bottom shear stress and sediment concentration are above 60%, approximately 20-30% and less than 10% for the water depth of less than 5 m, 5-10 m and more than 20 m, respectively. For the waters among islands, the proportion of wave contribution to bottom shear stress and sediment concentration is reduced to 10-20% for -5 m water depth and this is more obvious for the waves of large amplitude. The bottom stress and suspended sediment concentration between islands are mainly controlled by tidal current, and the effect of wave is not significant.

  5. The Tsushima Warm Current from a High Resolution Ocean Prediction Model, HYCOM

    Directory of Open Access Journals (Sweden)

    Seongbong Seo

    2013-06-01

    Full Text Available This study investigates the characteristic of the Tsushima Warm Current from an assimilated high resolution global ocean prediction model, 1/12o Global HYbrid Coordiate Ocean Model (HYCOM. The model results were verified through a comparison with current measurements obtained by acoustic Doppler current profiler (ADCP mounted on the passenger ferryboat between Busan, Korea, and Hakata, Japan. The annual mean transport of the Tsushima Warm Current was 2.56 Sverdrup (Sv (1 Sv = 106 m3s−1, which is similar to those from previous studies (Takikawa et al. 1999; Teague et al. 2002. The volume transport time series of the Tsushima Warm Current from HYCOM correlates to a high degree with that from the ADCP observation (the correlation coefficient between the two is 0.82. The spatiotemporal structures of the currents as well as temperature and salinity from HYCOM are comparable to the observed ones.

  6. Modeling the dark current histogram induced by gold contamination in complementary-metal-oxide-semiconductor image sensors

    Science.gov (United States)

    Domengie, F.; Morin, P.; Bauza, D.

    2015-07-01

    We propose a model for dark current induced by metallic contamination in a CMOS image sensor. Based on Shockley-Read-Hall kinetics, the expression of dark current proposed accounts for the electric field enhanced emission factor due to the Poole-Frenkel barrier lowering and phonon-assisted tunneling mechanisms. To that aim, we considered the distribution of the electric field magnitude and metal atoms in the depth of the pixel. Poisson statistics were used to estimate the random distribution of metal atoms in each pixel for a given contamination dose. Then, we performed a Monte-Carlo-based simulation for each pixel to set the number of metal atoms the pixel contained and the enhancement factor each atom underwent, and obtained a histogram of the number of pixels versus dark current for the full sensor. Excellent agreement with the dark current histogram measured on an ion-implanted gold-contaminated imager has been achieved, in particular, for the description of the distribution tails due to the pixel regions in which the contaminant atoms undergo a large electric field. The agreement remains very good when increasing the temperature by 15 °C. We demonstrated that the amplification of the dark current generated for the typical electric fields encountered in the CMOS image sensors, which depends on the nature of the metal contaminant, may become very large at high electric field. The electron and hole emissions and the resulting enhancement factor are described as a function of the trap characteristics, electric field, and temperature.

  7. Finite-elements numerical model of the current-sheet movement and shaping in coaxial discharges

    Energy Technology Data Exchange (ETDEWEB)

    Casanova, Federico [CNEA-CONICET and Universidad Nacional del Centro, 7000 Tandil (Argentina); Moreno, Cesar [INFIP-PLADEMA, Universidad de Buenos Aires, 1428 Buenos Aires (Argentina); Clausse, Alejandro [CNEA-CONICET and Universidad Nacional del Centro, 7000 Tandil (Argentina)

    2005-08-01

    The movement and shaping of the current sheath in coaxial plasma guns is numerically modelled by means of a dynamic finite-elements representation. Numerical instabilities are avoided by a reshaping algorithm applied during the tracking of the current sheath acceleration. Improving upon older versions of the algorithm, the present model includes a delay model to treat the dielectric breakdown. Comparison against experimental measurements showed very good performances in representing the arrival times of the shock front at different filling pressures.

  8. A first proposal for a general description model of forensic traces

    Science.gov (United States)

    Lindauer, Ina; Schäler, Martin; Vielhauer, Claus; Saake, Gunter; Hildebrandt, Mario

    2012-06-01

    In recent years, the amount of digitally captured traces at crime scenes increased rapidly. There are various kinds of such traces, like pick marks on locks, latent fingerprints on various surfaces as well as different micro traces. Those traces are different from each other not only in kind but also in which information they provide. Every kind of trace has its own properties (e.g., minutiae for fingerprints, or raking traces for locks) but there are also large amounts of metadata which all traces have in common like location, time and other additional information in relation to crime scenes. For selected types of crime scene traces, type-specific databases already exist, such as the ViCLAS for sexual offences, the IBIS for ballistic forensics or the AFIS for fingerprints. These existing forensic databases strongly differ in the trace description models. For forensic experts it would be beneficial to work with only one database capable of handling all possible forensic traces acquired at a crime scene. This is especially the case when different kinds of traces are interrelated (e.g., fingerprints and ballistic marks on a bullet casing). Unfortunately, current research on interrelated traces as well as general forensic data models and structures is not mature enough to build such an encompassing forensic database. Nevertheless, recent advances in the field of contact-less scanning make it possible to acquire different kinds of traces with the same device. Therefore the data of these traces is structured similarly what simplifies the design of a general forensic data model for different kinds of traces. In this paper we introduce a first common description model for different forensic trace types. Furthermore, we apply for selected trace types from the well established database schema development process the phases of transferring expert knowledge in the corresponding forensic fields into an extendible, database-driven, generalised forensic description model. The

  9. Magnetic mapping and Birkeland currents in the Toffoletto-Hill and Tsyganenko magnetosphere models

    Science.gov (United States)

    Ding, Cheng; Hill, T. W.; Toffoletto, F. R.

    1994-01-01

    We investigate the mapping of magnetic flux tubes between the high-latitude ionosphere and the equatorial magnetosphere, using the Toffoletto and Hill (1989) theoretical model and the Tsyganenko (1987, 1989) empirical models. In all models, strong distortion of flux tubes occurs near the magnetopause and in the distant tail. These effects are illustrated for various interplanetary magnetic field directions in the Toffoletto and Hill (1989) model and for various Kp values in the Tsyganenko (1987, 1989) model. We calculate the Birkeland current that is actually present in each model (from Ampere's law), as well as the Birkeland current that would be implied if the model were in magnetostatic equilibrium with isotropic plasma pressure (from the Vasyliunas equation). Comparison of the actual and implied Birkeland currents indicates that no physically significant Birkeland current is included in any of the models tested. Each model contains a 'noise' component of Birkeland current that is, however, much smaller in magnitude than the 'real' Birkeland currents that remain to be included.

  10. Rectal Adenocarcinoma: Proposal for a Model Based on Pretreatment Prognostic Factors

    Science.gov (United States)

    Cabanillas, Fernando; Freire, Viviana; Nieves-Plaza, Mariely; Quevedo, Gerardo; Echenique, Ignacio A.

    2012-01-01

    Objective Currently the choice of chemotherapy regimen in rectal cancer is made prior to surgery in contrast to colon cancer where it is made postoperatively after the pathological stage has been determined. If we could identify which are the important pretreatment prognostic factors in rectal cancer, we could then target those patients with unfavorable features to investigate potentially more effective preoperative chemotherapy regimens aimed at those with unfavorable features. The present study aims to determine pre-treatment prognostic factors that are associated with an unfavorable outcome. Methods A retrospective review of 99 rectal cancer patients operated at the Hospital Auxilio Mutuo and Hospital San Pablo was done. Sociodemographic characteristics, clinical and treatment data was collected. Results 54% were males. The mean ± sd age was 62.2 ± 10.4. In age-adjusted Cox model, male gender [HR (95%CI): 3.32 (1.09–10.13)], mucinous carcinoma [HR (95%CI): 3.67 (1.25–10.77)], and clinical stages II & III [HR (95%CI): 8.19 (1.08–62.08)] were predictors of poor prognosis. In multivariate age-adjusted analysis, a tendency towards a poorer prognosis was observed for male patients [HR: 2.60] CEA level ≥ 5ng/ml [HR: 2.55], mucinous carcinoma [HR:2.96], and clinical stages II & III [HR:4.96], although results were not statistically significant (p>0.05), Conclusion Although current therapeutic results are relatively favorable with preoperative 5-Fluorouracil (5FU) and radiotherapy, future clinical trials should address the management of those cases with adverse pretreatment prognostic factors so that they can be treated with potentially more effective albeit more toxic chemotherapy regimens. PMID:22783696

  11. Early maternal deprivation in rats: a proposed animal model for the study of developmental neuroimmunoendocrine interactions.

    Science.gov (United States)

    De la Fuente, M; Llorente, R; Baeza, I; De Castro, N M; Arranz, L; Cruces, J; Viveros, M P

    2009-02-01

    Adult animals that had been subjected to a single prolonged episode of maternal deprivation (MD) [24 h, postnatal day (PND) 9-10] show long-term behavioral alterations that resemble specific symptoms of schizophrenia. Moreover, at adolescence MD rats showed depressive-like behavior and altered motor responses. According to the neurodevelopmental hypothesis, certain behavioral abnormalities observed in MD animals may be related to altered neurodevelopmental processes triggered by MD-induced elevated glucocorticoids in relevant specific brain regions. We review here these neuroendocrine effects and show new data indicating that the MD procedure induces diverse detrimental effects on the immune system that are already revealed in the short term (PND 13) and persist into adulthood. These long-lasting effects might be related to altered hypothalamus-pituitary-adrenal axis activity and to social as well as nutrition-related factors. In fact, MD induces long-lasting decreases in body weight. In view of our findings we propose the present MD procedure as a potentially useful model to analyze developmental interactions between early psychophysiological stress and immunodeficient states.

  12. The Brazilian Unified National Health System: Proposal of a Cost-effectiveness Evaluation Model

    Directory of Open Access Journals (Sweden)

    Lilian Ribeiro de Oliveira

    2016-04-01

    Full Text Available The Brazilian Unified National Health System (Sistema Único de Saúde [SUS] is in a prominent position compared to the existing social policies. One of the new tools used by SUS is known as Performance Index of the Unified Health System (Índice de Desempenho do Sistema Único de Saúde [IDSUS], which is intended to measure the performance of each municipality. Therefore, the aim of this study was to propose a model of cost-effectiveness to compare IDSUS performance against total revenues achieved in Homogeneous Group 2, consisting of 94 municipalities and analysed using data from IDSUS and the System Information of the Public Budget for Health Care (Sistema de Informação do Orçamento Público em Saúde [SIOPS] for the year 2011. After structuring this data, we carried out descriptive statistical and cluster analysis in order to group similar municipalities in accordance with established variables: IDSUS performance, population and total revenue in health per capita. Even with the division of municipalities into homogeneous groups and after using variables such as population and revenue to regroup them, the results showed there are municipalities with heterogeneous characteristics. Another finding is in the use and intersection of two distinct databases (IDSUS and SIOPS, which allowed for visualizing the impact of health care revenue on the municipalities performance.

  13. [Proposed difficult airway teaching methodology. Presentation of an interactive fresh frozen cadaver model].

    Science.gov (United States)

    Catalá Bauset, J C; de Andres Ibañez, J A; Valverde Navarro, A; Martinez Soriano, F

    2014-04-01

    The aim of this paper is to present a methodology based on the use of fresh-frozen cadavers for training in the management of the airway, and to evaluate the degree of satisfaction among learning physicians. About 6 fresh-frozen cadavers and 14 workstations were prepared where participants were trained in the different skills needed for airway management. The details of preparation of the cadavers are described. The level of satisfaction of the participant was determined using a Likert rating scale of 5 points, at each of the 14 stations, as well as the overall assessment and clinical usefulness of the course. The mean overall evaluation of the course and its usefulness was 4.75 and 4.9, out of 5, respectively. All parts of the course were rated above 4 out of 5. The high level of satisfaction of the course remained homogeneous in the 2 editions analysed. The overall satisfaction of the course was not finally and uniquely determined by any of its particular parts. The fresh cadaver model for training physicians in techniques of airway management is a proposal satisfactory to the participant, and with a realism that approaches the live patient. Copyright © 2013 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Published by Elsevier España. All rights reserved.

  14. The effects of patient weight and sex on nurses' perceptions: a proposed model of nurse withdrawal.

    Science.gov (United States)

    Peternelj-Taylor, C A

    1989-09-01

    This investigation challenged the premise that nurses adhere to affective neutrality in their practice of nursing, and examined the effect of patient weight and sex on evaluations, attributions and care delivery decisions formed by nurses. The phenomenon of mutual withdrawal originally identified by Tudor in psychiatric nursing was adapted to the general nursing milieu and served as the conceptual framework. Emphasis in this study was given to the phenomenon of nurse withdrawal. A volunteer sample of 100 senior female baccalaureate students was randomly assigned to one of four conditions in a 2 X 2 factorial design with the following factors: (a) weight of the stimulus patient (normal versus obese); and (b) sex of the stimulus patient (male versus female). These independent variables were presented through descriptive vignettes and visual stimuli to participants completing a self-administered questionnaire. Dependent variables included evaluation, attribution and care delivery. Analysis of the questionnaire demonstrated that obese patients were evaluated more negatively than normal weight patients, F = 2.82, P less than 0.05, but were not held more responsible for an alleged transgression, nor did nurses indicate withdrawal. The phenomenon of social attractiveness was identified as an intervening variable lending support to the proposed model of nurse withdrawal. This finding is examined within the context of affective neutrality in the nurse-patient relationship. Implications for nursing practice, theory and research are discussed.

  15. A Proposed mHealth Model for Improving the Quality Care in Hospitals

    Directory of Open Access Journals (Sweden)

    Hussain Abu-Dalbouh

    2014-02-01

    Full Text Available As the hospitals face increasing demands to participate in a wide range of quality improvement activities, the role and influence of physicians and nurses in these efforts is also increasing. The growing population has led to increase the number of patients in hospital. Therefore, healthcare workers have to see more patients and do more with each patient than ever before. Thus, Hospitals confront challenges with regard tracking patient condition, share information about the patient and difficulty follow up all patients with the lack of the number of specialist physician at all levels. This marks mobile devices an important opportunity for the next generation healthcare delivery. This study proposed a mobile health model that could support hospitals in tracking patient’s progress and improve the quality care in hospitals. It allows physicians and nurses to track the patients’ conditions more efficiently and easily. It also able to assist in crucial clinical decisions 24/7 and available on call wherever physicians to manage their care process from start to finish and from inside and outside the hospital.

  16. Assessing the risk of attack in the management of asthma: a review and proposal for revision of the current control-centred paradigm.

    Science.gov (United States)

    Blakey, John D; Woolnough, Kerry; Fellows, Jodie; Walker, Samantha; Thomas, Mike; Pavord, Ian D

    2013-09-01

    Asthma guidelines focus on day-to-day control of symptoms. However, asthma attacks remain common. They continue to cause mortality and considerable morbidity, and are a major financial burden to the UK National Health Service (NHS) and the wider community. Asthma attacks have chronic consequences, being associated with loss of lung function and significant psychological morbidity. In this article we argue that addressing daily symptom control is only one aspect of asthma treatment, and that there should be a more explicit focus on reducing the risk of asthma attacks. Management of future risk by general practitioners is already central to other conditions such as ischaemic heart disease and chronic renal impairment. We therefore propose a revised approach that separately considers the related domains of daily control and future risk of asthma attack. We believe this approach will have advantages over the current 'stepwise' approach to asthma management. It should encourage individualised treatment, including non-pharmacological measures, and thus may lead to more efficacious and less harmful management strategies. We speculate that this type of approach has the potential to reduce morbidity and healthcare costs related to asthma attacks.

  17. Current radiography and tomography applications at Necsa and an envisaged upgrade towards a proposed South African national centre for radiography and tomography (SANCRAT)

    Energy Technology Data Exchange (ETDEWEB)

    Radebe, M.J.; De Beer, F.C. [Necsa - South African Nuclear Energy Corporation Limited, P. O.Box 582, Pretoria, 0001 (South Africa)

    2008-07-01

    An upgrade of the current Radiography and Tomography Research facilities is envisaged to enhance the group's support for Necsa's mission to undertake and support nuclear research and utilize penetrating radiation for the benefit of mankind. It is envisage that the SANCRAT will host neutron-, X-ray- and gamma ray penetrating radiation imaging infrastructures that can be utilized by researchers from industry as well as post graduate students from higher educational institutions. Modelling for the upgrade to a multifunctional neutron radiography and tomography facility has been underway. Upgrade plans and implementation has also begun for a 250 kV X-ray radiography set-up, that will exist independent from the neutron facility. Future expansion entails catering for a micro-focus X-ray -, and gamma ray radiography and tomography facilities. The current facilities available consist of one infrastructure facility based on two sources of penetrating radiation, i.e. SAFARI-1 research nuclear reactor as thermal neutron source and a 100 kV X-ray generator. This facility, which hosts the only operational neutron tomography R and D facility in the Southern Hemisphere and in Africa, are being extensively utilized by post graduate students and industry. The facility sees application in a wide range of scientific and engineering disciplines, amongst which is nuclear, geosciences, palaeontology, civil, mechanical, chemical, etc. This paper focus on case studies engaged at the current radiography and tomography facilities over the past 2 years as well as describing the envisaged upgrade initiatives to a fully equipped national centre. (authors)

  18. Modified model of gate leakage currents in AlGaN/GaN HEMTs

    Science.gov (United States)

    Wang, Yuan-Gang; Feng, Zhi-Hong; Lv, Yuan-Jie; Tan, Xin; Dun, Shao-Bo; Fang, Yu-Long; Cai, Shu-Jun

    2016-10-01

    It has been reported that the gate leakage currents are described by the Frenkel-Poole emission (FPE) model, at temperatures higher than 250 K. However, the gate leakage currents of our passivated devices do not accord with the FPE model. Therefore, a modified FPE model is developed in which an additional leakage current, besides the gate (I II), is added. Based on the samples with different passivations, the I II caused by a large number of surface traps is separated from total gate currents, and is found to be linear with respect to (φ B-V g)0.5. Compared with these from the FPE model, the calculated results from the modified model agree well with the I g-V g measurements at temperatures ranging from 295 K to 475 K. Project supported by the National Natural Science Foundation of China (Grant No. 61306113).

  19. Equidistance of branch structure in capacitively coupled Josephson junctions model with diffusion current

    Energy Technology Data Exchange (ETDEWEB)

    Shukrinov, Yu.M. [BLTP, JINR, Dubna, Moscow Region, 141980 (Russian Federation) and Physical Technical Institute, Dushanbe 734063 (Tajikistan)]. E-mail: shukrinv@theor.jinr.ru; Mahfouzi, F. [Institute for Advanced Studies in Basic Sciences, P.O. Box 45195-1159, Zanjan (Iran, Islamic Republic of); Seidel, P. [Institut fuer Festkorperphysik, Friedrich-Schiller-Universitaet Jena, D-07743 Jena (Germany)

    2006-11-01

    Branch structure in current-voltage characteristics of intrinsic Josephson junctions of HTSC is studied in the framework of two models: capacitively coupled Josephson junctions (CCJJ) model and CCJJ model with diffusion current (CCJJ + DC). We investigate the coupling dependence of the branch's slopes and demonstrate that the equidistance of the branch structure in CCJJ model is broken at enough small values of coupling parameter (at {alpha} << 1). We show that the inclusion of diffusion in the tunneling current through intrinsic Josephson junctions might restore the equidistance of the branch structure. Change of the current-voltage characteristics in CCJJ + DC model under variation of the coupling and McCumber parameters and effect of boundary conditions on the branch structure is analyzed.

  20. Equidistance of branch structure in capacitively coupled Josephson junctions model with diffusion current

    Science.gov (United States)

    Shukrinov, Yu. M.; Mahfouzi, F.; Seidel, P.

    2006-11-01

    Branch structure in current-voltage characteristics of intrinsic Josephson junctions of HTSC is studied in the framework of two models: capacitively coupled Josephson junctions (CCJJ) model and CCJJ model with diffusion current (CCJJ + DC). We investigate the coupling dependence of the branch’s slopes and demonstrate that the equidistance of the branch structure in CCJJ model is broken at enough small values of coupling parameter (at α ≪ 1). We show that the inclusion of diffusion in the tunneling current through intrinsic Josephson junctions might restore the equidistance of the branch structure. Change of the current-voltage characteristics in CCJJ + DC model under variation of the coupling and McCumber parameters and effect of boundary conditions on the branch structure is analyzed.