WorldWideScience

Sample records for dynamic system doctor

  1. How many doctors should we train for Sri Lanka? System dynamics modelling for training needs

    Science.gov (United States)

    De Silva, D

    2017-12-26

    Over the years, Sri Lanka has achieved remarkable health gains for the money spent on health. Currently about 1450 doctors enter the health system annually. While some advocate opening up of new medical schools to address an apparent shortage of doctors in the country, others argue against it. To identify the number of doctors Sri Lanka need. System dynamics, an analytical modelling approach and a methodology for studying complex feedback systems was used. Two sub models of “need” and “supply” were developed and simulated for a period of 15 years from 2017 to 2032 At present the doctor to population ratio is 1:671 and 91% of the need has been met. This study shows that currently there is a shortage of doctors in the country. However, the supply will match the need by 2025/26. Increasing the number of doctors, will result in oversupply of doctors towards the latter part of the next decade. There is no acute necessity to open up new Medical Schools. However comprehensive health workforce analysis needs to be done once in 5 years and the number of doctors to be trained, decided accordingly.

  2. Development and application of the dynamic system doctor to nuclear reactor probabilistic risk assessments.

    Energy Technology Data Exchange (ETDEWEB)

    Kunsman, David Marvin; Aldemir, Tunc (Ohio State University); Rutt, Benjamin (Ohio State University); Metzroth, Kyle (Ohio State University); Catalyurek, Umit (Ohio State University); Denning, Richard (Ohio State University); Hakobyan, Aram (Ohio State University); Dunagan, Sean C.

    2008-05-01

    This LDRD project has produced a tool that makes probabilistic risk assessments (PRAs) of nuclear reactors - analyses which are very resource intensive - more efficient. PRAs of nuclear reactors are being increasingly relied on by the United States Nuclear Regulatory Commission (U.S.N.R.C.) for licensing decisions for current and advanced reactors. Yet, PRAs are produced much as they were 20 years ago. The work here applied a modern systems analysis technique to the accident progression analysis portion of the PRA; the technique was a system-independent multi-task computer driver routine. Initially, the objective of the work was to fuse the accident progression event tree (APET) portion of a PRA to the dynamic system doctor (DSD) created by Ohio State University. Instead, during the initial efforts, it was found that the DSD could be linked directly to a detailed accident progression phenomenological simulation code - the type on which APET construction and analysis relies, albeit indirectly - and thereby directly create and analyze the APET. The expanded DSD computational architecture and infrastructure that was created during this effort is called ADAPT (Analysis of Dynamic Accident Progression Trees). ADAPT is a system software infrastructure that supports execution and analysis of multiple dynamic event-tree simulations on distributed environments. A simulator abstraction layer was developed, and a generic driver was implemented for executing simulators on a distributed environment. As a demonstration of the use of the methodological tool, ADAPT was applied to quantify the likelihood of competing accident progression pathways occurring for a particular accident scenario in a particular reactor type using MELCOR, an integrated severe accident analysis code developed at Sandia. (ADAPT was intentionally created with flexibility, however, and is not limited to interacting with only one code. With minor coding changes to input files, ADAPT can be linked to other

  3. Learning Dynamics in Doctoral Supervision

    DEFF Research Database (Denmark)

    Kobayashi, Sofie

    This doctoral research explores doctoral supervision within life science research in a Danish university. From one angle it investigates doctoral students’ experiences with strengthening the relationship with their supervisors through a structured meeting with the supervisor, prepared as part...... investigates learning opportunities in supervision with multiple supervisors. This was investigated through observations and recording of supervision, and subsequent analysis of transcripts. The analyses used different perspectives on learning; learning as participation, positioning theory and variation theory....... The research illuminates how learning opportunities are created in the interaction through the scientific discussions. It also shows how multiple supervisors can contribute to supervision by providing new perspectives and opinions that have a potential for creating new understandings. The combination...

  4. Healthcare system design and parttime working doctors

    NARCIS (Netherlands)

    Molema, J. J. W.; Groothuis, S.; Baars, I. J.; Kleinschiphorst, M.; Leers, E. G. E.; Hasman, A.; van Merode, G. G.

    2007-01-01

    More doctors would like to work parttime. Since research on fitting healthcare system design with the structure of parttime jobs is lacking, we studied how parttime work for medical doctors could be enabled from a system design perspective. A theoretical analysis was performed, illustrated by two

  5. The system of licensing doctors in China.

    Science.gov (United States)

    Jianyi, Ge

    2008-06-01

    This article gives an overview of the history and current system of licensing doctors in China. It first reviews the progress of medical legislation since 1949 and then explains reforms in the regulation of the medical practice of licensed doctors and their registration for entrance into the profession. In order to explore a way to adapt the system of licensing doctors presently in use in China to an international standard, the author proposes five strategies to reform policy, including internationalization based on the Chinese situation. Equal importance is to be placed on general practitioners and specialists, optimizing administration at different levels and in different categories, improving the quality of countryside doctors, and establishing a promotion system based on accreditation. The author concludes that for reference China should introduce the international standard of medical education and experience in medical training to raise the quality of doctors, regularize medical administration, develop a balanced professional force of general practitioners and specialists, and involve China in the global system of recognition of doctors.

  6. Contextual dynamics in clinical workplaces: learning from doctor-doctor consultations.

    Science.gov (United States)

    Pimmer, Christoph; Pachler, Norbert; Genewein, Urs

    2013-05-01

    Some studies have explored the role of learning context in clerkships and in clinical teams. Very little is known, however, about the relationship between context and competence development in more loosely framed, day-to-day practices such as doctor-doctor consultations, although such interactions are frequent and typical in clinical work. To address this gap in the literature, a study was conducted using semi-structured interviews in four different hospitals and participant observation at one site. Inductive content analysis was used to develop a framework. Special reference was made to the principles of situated cognition. The framework illustrates how different situational, personal and organisational factors interact in every learning situation. The interplay manifests in three different roles that doctors assume in highly dynamic ways: doctors learn as 'actors' (being responsible), as 'participants' (being involved) and as 'students' (being taught); contextual influences also impact on the quality of learning within these roles. The findings add to the current literature on clinical workplace learning and to the conceptualisation of context in the field of education. The practical contribution of the research lies in disentangling the complex dynamics of learning in clinical environments and in helping doctors and medical educators to increase their responsiveness to contextual factors. © Blackwell Publishing Ltd 2013.

  7. Dynamical systems

    CERN Document Server

    Sternberg, Shlomo

    2010-01-01

    Celebrated mathematician Shlomo Sternberg, a pioneer in the field of dynamical systems, created this modern one-semester introduction to the subject for his classes at Harvard University. Its wide-ranging treatment covers one-dimensional dynamics, differential equations, random walks, iterated function systems, symbolic dynamics, and Markov chains. Supplementary materials offer a variety of online components, including PowerPoint lecture slides for professors and MATLAB exercises.""Even though there are many dynamical systems books on the market, this book is bound to become a classic. The the

  8. Which Doctor to Trust: A Recommender System for Identifying the Right Doctors.

    Science.gov (United States)

    Guo, Li; Jin, Bo; Yao, Cuili; Yang, Haoyu; Huang, Degen; Wang, Fei

    2016-07-07

    Key opinion leaders (KOLs) are people who can influence public opinion on a certain subject matter. In the field of medical and health informatics, it is critical to identify KOLs on various disease conditions. However, there have been very few studies on this topic. We aimed to develop a recommender system for identifying KOLs for any specific disease with health care data mining. We exploited an unsupervised aggregation approach for integrating various ranking features to identify doctors who have the potential to be KOLs on a range of diseases. We introduce the design, implementation, and deployment details of the recommender system. This system collects the professional footprints of doctors, such as papers in scientific journals, presentation activities, patient advocacy, and media exposure, and uses them as ranking features to identify KOLs. We collected the information of 2,381,750 doctors in China from 3,657,797 medical journal papers they published, together with their profiles, academic publications, and funding. The empirical results demonstrated that our system outperformed several benchmark systems by a significant margin. Moreover, we conducted a case study in a real-world system to verify the applicability of our proposed method. Our results show that doctors' profiles and their academic publications are key data sources for identifying KOLs in the field of medical and health informatics. Moreover, we deployed the recommender system and applied the data service to a recommender system of the China-based Internet technology company NetEase. Patients can obtain authority ranking lists of doctors with this system on any given disease.

  9. Dynamical systems

    CERN Document Server

    Birkhoff, George D

    1927-01-01

    His research in dynamics constitutes the middle period of Birkhoff's scientific career, that of maturity and greatest power. -Yearbook of the American Philosophical Society The author's great book€¦is well known to all, and the diverse active modern developments in mathematics which have been inspired by this volume bear the most eloquent testimony to its quality and influence. -Zentralblatt MATH In 1927, G. D. Birkhoff wrote a remarkable treatise on the theory of dynamical systems that would inspire many later mathematicians to do great work. To a large extent, Birkhoff was writing about his o

  10. Impact of doctors' resistance on success of drug utilization review system.

    Science.gov (United States)

    Choi, Jong Soo; Yun, Seong Hyeon; Kim, Dongsoo; Park, Seung Woo

    2014-04-01

    The drug utilization review (DUR) system, which checks any conflict event of medications, contributes to improve patient safety. One of the important barriers in its adoption is doctors' resistance. This study aimed to analyze the impacts of doctors' resistance on the success of the DUR system. This study adopted an augmented the DeLone and McLean Information System (D&M IS) Success Model (2003), which used doctors' resistance as a socio-technological measure. This study framework is the same as that of the D&M IS Success Model in that it is based on qualities, such as system, information, and services. The major difference is that this study excluded the variable 'use' because it was not statistically significant for mandatory systems. A survey of doctors who used computers to enter prescriptions was conducted at a Korean tertiary hospital in February 2012. This study is very meaningful in that it is the first study to explore the success factors of the DUR system associated with doctors' resistance. Doctors' resistance to the DUR system was not statistically associated with user usefulness, whereas it affected user satisfaction. The results indicate that doctors still complain of discomfort in using the DUR system in the outpatient clinical setting, even though they admit that it contributes to patient safety. To mitigate doctors' resistance and raise user satisfaction, more opinions from doctors regarding the DUR system have to be considered and have to be reflected in the system.

  11. Planar dynamical systems selected classical problems

    CERN Document Server

    Liu, Yirong; Huang, Wentao

    2014-01-01

    This book presents in an elementary way the recent significant developments in the qualitative theory of planar dynamical systems. The subjects are covered as follows: the studies of center and isochronous center problems, multiple Hopf bifurcations and local and global bifurcations of the equivariant planar vector fields which concern with Hilbert's 16th problem. This book is intended for graduate students, post-doctors and researchers in the area of theories and applications of dynamical systems. For all engineers who are interested the theory of dynamical systems, it is also a reasona

  12. Dynamic Interactive Learning Systems

    Science.gov (United States)

    Sabry, Khaled; Barker, Jeff

    2009-01-01

    This paper reviews and discusses the notions of interactivity and dynamicity of learning systems in relation to information technologies and design principles that can contribute to interactive and dynamic learning. It explores the concept of dynamic interactive learning systems based on the emerging generation of information as part of a…

  13. [Awareness survey of Healthcare Number System pros and cons according to medical doctors in Japan].

    Science.gov (United States)

    Takahashi, Yoshimitsu; Uryuhara, Yoko; Inoue, Machiko; Okamoto, Shigeru; Kashihara, Hidenori; Kito, Kumiko; Shinohara, Keiko; Mandai, Marie; Morioka, Miho; Tanaka, Shiro; Kawakami, Koji; Nakayama, Takeo

    2015-01-01

    After bills to launch the Social Security and Tax Number System were enacted in 2013, health and political officials have considered the Healthcare Number System (the System). However, little is known about doctors' awareness and concerns about the System. This study aimed to measure how many doctors disagree with the System, examine the doctors' characteristics, and analyze the benefits and harms of the System that they identified. A cross-sectional survey was conducted of doctors via the Internet. The participants were selected from a convenience sample of a panel of doctors based on stratified sampling including four groups: working at a hospital and harms were analyzed using qualitative content analysis. There were 562 respondents (68%). By group, 16/143 (11%), 25/138 (18%), 31/132 (23%), and 43/149 (29%) doctors, respectively, thought that the System was unnecessary. The variables that correlated with the main outcome were age (per 5 years; odds ratio [95% confidence interval], 1.14 [1.01-1.29]) and type of medical facility (working at a clinic; 1.99 [1.30-3.08]). The doctors identified that unifying information could decrease administrative duties, facilitate inter-facility collaboration, and prevent inappropriate medical consultations. This could result in decreased healthcare costs and personalized healthcare. However, the doctors also identified that integrating information and dealing with big data could increase information leakage and information management, cause over-monitoring of doctors, and enable the inappropriate use of integrated information. This could result in deteriorating healthcare. Since some information should not be integrated, the System raises ethical considerations about privacy. Among the doctors surveyed here, 10-30% thought the System was unnecessary. These respondents tended to be older and work at a clinic. The System could decrease the cost of healthcare and enable personalized healthcare but could also increase information

  14. Spaces of Dynamical Systems

    CERN Document Server

    Pilyugin, Sergei Yu

    2012-01-01

    Dynamical systems are abundant in theoretical physics and engineering. Their understanding, with sufficient mathematical rigor, is vital to solving many problems. This work conveys the modern theory of dynamical systems in a didactically developed fashion.In addition to topological dynamics, structural stability and chaotic dynamics, also generic properties and pseudotrajectories are covered, as well as nonlinearity. The author is an experienced book writer and his work is based on years of teaching.

  15. Dynamical Systems Conference

    CERN Document Server

    Gils, S; Hoveijn, I; Takens, F; Nonlinear Dynamical Systems and Chaos

    1996-01-01

    Symmetries in dynamical systems, "KAM theory and other perturbation theories", "Infinite dimensional systems", "Time series analysis" and "Numerical continuation and bifurcation analysis" were the main topics of the December 1995 Dynamical Systems Conference held in Groningen in honour of Johann Bernoulli. They now form the core of this work which seeks to present the state of the art in various branches of the theory of dynamical systems. A number of articles have a survey character whereas others deal with recent results in current research. It contains interesting material for all members of the dynamical systems community, ranging from geometric and analytic aspects from a mathematical point of view to applications in various sciences.

  16. PROBLEM OF FORMATION OF THE SYSTEMIC PHILOSOPHY OF THE DOCTOR

    Directory of Open Access Journals (Sweden)

    T. V. Novikova

    2014-01-01

    Full Text Available he problem is to translate medical knowledge into the philosophy of the specialist so that he has learned to see mentally not only the thinnest biological structures, but also to feel their displays in scales of a holistic organism. To achieve such effect, special translators are required. For their creation the biomedical knowledge is considered from the viewpoint of sciences about systems: cybernetics, synergetics, nonlinear dynamics, management theory. Examples: model of homeostasis support in terms of the management theory, the adaptation as a series of recombinations of functional systems in the space of compensatory-adaptive reactions, notion of an information resource of adaptive behavior, understanding of structural disorganization of a membrane of the red blood cells as of a universal model of reaction of a holistic organism. For substantiation the possibility to solve the task representation systemic world outlook and systems thinking are introduced, model of self-organization in the system of specialist knowledge and psychology of creative thinking have been involved.

  17. Achieving change and altering behaviour through direct doctor use of a hospital information system for order communications.

    Science.gov (United States)

    Soar, J; Ayres, D; Van der Weegen, L

    1993-01-01

    Direct use of hospital information systems, and particularly of order communications systems by doctors, is central to the anticipated benefits from hospital information systems in Australia and other countries. There is an expectation that doctors will accept this technology and that the benefits will flow from their use. Concord Repatriation General Hospital in Sydney is one of very few hospitals in the world where doctors directly use a hospital information system to access patient information, place orders for diagnostic services and retrieve results. This paper reports on research which explored the nature of the direct doctor use of the hospital information system at Concord Hospital, and the changing attitudes of the doctors there.

  18. Development of village doctors in China: financial compensation and health system support.

    Science.gov (United States)

    Hu, Dan; Zhu, Weiming; Fu, Yaqun; Zhang, Minmin; Zhao, Yang; Hanson, Kara; Martinez-Alvarez, Melisa; Liu, Xiaoyun

    2017-07-01

    Since 1968, China has trained about 1.5 million barefoot doctors in a few years' time to provide basic health services to 0.8 billion rural population. China's Ministry of Health stopped using the term of barefoot doctor in 1985, and changed policy to develop village doctors. Since then, village doctors have kept on playing an irreplaceable role in China's rural health, even though the number of village doctors has fluctuated over the years and they face serious challenges. United Nations declared Sustainable Development Goals in 2015 to achieve universal health coverage by 2030. Under this context, development of Community Health workers (CHWs) has become an emerging policy priority in many resource-poor developing countries. China's experiences and lessons learnt in developing and maintaining village doctors may be useful for these developing countries. This paper aims to synthesis lessons learnt from the Chinese CHW experiences. It summarizes China's experiences in exploring and using strategic partnership between the community and the formal health system to develop CHWs in the two stages, the barefoot doctor stage (1968 -1985) and the village doctor stage (1985-now). Chinese and English literature were searched from PubMed, CNKI and Wanfang. The information extracted from the selected articles were synthesized according to the four partnership strategies for communities and health system to support CHW development, namely 1) joint ownership and design of CHW programmes; 2) collaborative supervision and constructive feedback; 3) a balanced package of incentives, both financial and non-financial; and 4) a practical monitoring system incorporating data from the health system and community. The study found that the townships and villages provided an institutional basis for barefoot doctor policy, while the formal health system, including urban hospitals, county health schools, township health centers, and mobile medical teams provided training to the barefoot

  19. Systems With Emergent Dynamics

    Science.gov (United States)

    Stewart, Ian

    2002-09-01

    Evolutionary biologists often reject deterministic models of evolutionary processes because they equate `deterministic' with `goal-seeking', and have learned the hard way not to trust goal-seeking explanations of evolutionary adaptations. On the other hand, the general theory of dynamical systems potentially has much to offer for evolutionary biology— for example, as a resolution of the conflict between gradualism and punctuated equilibrium. The concept of a system with emergent dynamics retains the deterministic nature of dynamical systems, while eliminating any goal-seeking interpretation. Define an emergent property of a complex system to be a property whose computation from the entity-level rules of the system is intractable (in some reasonable sense). Say that a dynamical system has emergent dynamics if the computation of trajectories is intractable. Then systems with emergent dynamics are deterministic but not goal-seeking. As such, they offer a sensible way to use dynamical systems as models for evolutionary processes in biology, and in other areas. We discuss these issues and examine a few simple aspects of emergence in dynamical systems.

  20. Dynamic Systems and Control Engineering

    International Nuclear Information System (INIS)

    Kim, Jong Seok

    1994-02-01

    This book deals with introduction of dynamic system and control engineering, frequency domain modeling of dynamic system, temporal modeling of dynamic system, typical dynamic system and automatic control device, performance and stability of control system, root locus analysis, analysis of frequency domain dynamic system, design of frequency domain dynamic system, design and analysis of space, space of control system and digital control system such as control system design of direct digital and digitalization of consecutive control system.

  1. Stability of dynamical systems

    CERN Document Server

    Liao, Xiaoxin; Yu, P 0

    2007-01-01

    The main purpose of developing stability theory is to examine dynamic responses of a system to disturbances as the time approaches infinity. It has been and still is the object of intense investigations due to its intrinsic interest and its relevance to all practical systems in engineering, finance, natural science and social science. This monograph provides some state-of-the-art expositions of major advances in fundamental stability theories and methods for dynamic systems of ODE and DDE types and in limit cycle, normal form and Hopf bifurcation control of nonlinear dynamic systems.ʺ Presents

  2. Dynamics of unstable systems

    International Nuclear Information System (INIS)

    Posch, H.A.; Narnhofer, H.; Thirring, W.

    1990-01-01

    We study the dynamics of classical particles interacting with attractive Gaussian potentials. This system is thermodynamically not stable and exhibits negative specific heat. The results of the computer simulation of the dynamics are discussed in comparison with various theories. In particular, we find that the condensed phase is a stationary solution of the Vlasov equation, but the Vlasov dynamics cannot describe the collapse. 14 refs., 1 tab., 11 figs. (Authors)

  3. Shadowing in dynamical systems

    CERN Document Server

    Pilyugin, Sergei Yu

    1999-01-01

    This book is an introduction to the theory of shadowing of approximate trajectories in dynamical systems by exact ones. This is the first book completely devoted to the theory of shadowing. It shows the importance of shadowing theory for both the qualitative theory of dynamical systems and the theory of numerical methods. Shadowing Methods allow us to estimate differences between exact and approximate solutions on infinite time intervals and to understand the influence of error terms. The book is intended for specialists in dynamical systems, for researchers and graduate students in the theory of numerical methods.

  4. Invitation to dynamical systems

    CERN Document Server

    Scheinerman, Edward R

    2012-01-01

    This text is designed for those who wish to study mathematics beyond linear algebra but are unready for abstract material. Rather than a theorem-proof-corollary exposition, it stresses geometry, intuition, and dynamical systems. 1996 edition.

  5. Functional System Dynamics

    NARCIS (Netherlands)

    Ligterink, N.E.

    2007-01-01

    Functional system dynamics is the analysis, modelling, and simulation of continuous systems usually described by partial differential equations. From the infinite degrees of freedom of such systems only a finite number of relevant variables have to be chosen for a practical model description. The

  6. Nesting doctoral students in collaborative North–South partnerships for health systems research

    Directory of Open Access Journals (Sweden)

    Svetla Loukanova

    2014-07-01

    Full Text Available Background: The European Union (EU supports North–South Partnerships and collaborative research projects through its Framework Programmes and Horizon 2020. There is limited research on how such projects can be harnessed to provide a structured platform for doctoral level studies as a way of strengthening health system research capacity in sub-Saharan Africa (SSA. Objective: The aim of this study was to explore the challenges of, and facilitating factors for, ‘nesting’ doctoral students in North–South collaborative research projects. The term nesting refers to the embedding of the processes of recruiting, supervising, and coordinating doctoral students in the overall research plan and processes. Design: This cross-sectional qualitative study was undertaken by the EU-funded QUALMAT Project. A questionnaire was implemented with doctoral students, supervisors, and country principal investigators (PIs, and content analysis was undertaken. Results: Completed questionnaires were received from nine doctoral students, six supervisors, and three country PIs (86% responses rate. The doctoral students from SSA described high expectations about the input they would receive (administrative support, equipment, training, supervision. This contrasted with the expectations of the supervisors for proactivity and self-management on the part of the students. The rationale for candidate selection, and understandings of the purpose of the doctoral students in the project were areas of considerable divergence. There were some challenges associated with the use of the country PIs as co-supervisors. Doctoral student progress was at times impeded by delays in the release of funding instalments from the EU. The paper provides a checklist of essential requirements and a set of recommendations for effective nesting of doctoral students in joint North–South projects. Conclusion: There are considerable challenges to the effective nesting of doctoral students within

  7. Nesting doctoral students in collaborative North–South partnerships for health systems research

    Science.gov (United States)

    Loukanova, Svetla; Prytherch, Helen; Blank, Antje; Duysburgh, Els; Tomson, Göran; Gustafsson, Lars L.; Sié, Ali; Williams, John; Leshabari, Melkizedeck; Haefeli, Walter E.; Sauerborn, Rainer; Fonn, Sharon

    2014-01-01

    Background The European Union (EU) supports North–South Partnerships and collaborative research projects through its Framework Programmes and Horizon 2020. There is limited research on how such projects can be harnessed to provide a structured platform for doctoral level studies as a way of strengthening health system research capacity in sub-Saharan Africa (SSA). Objective The aim of this study was to explore the challenges of, and facilitating factors for, ‘nesting’ doctoral students in North–South collaborative research projects. The term nesting refers to the embedding of the processes of recruiting, supervising, and coordinating doctoral students in the overall research plan and processes. Design This cross-sectional qualitative study was undertaken by the EU-funded QUALMAT Project. A questionnaire was implemented with doctoral students, supervisors, and country principal investigators (PIs), and content analysis was undertaken. Results Completed questionnaires were received from nine doctoral students, six supervisors, and three country PIs (86% responses rate). The doctoral students from SSA described high expectations about the input they would receive (administrative support, equipment, training, supervision). This contrasted with the expectations of the supervisors for proactivity and self-management on the part of the students. The rationale for candidate selection, and understandings of the purpose of the doctoral students in the project were areas of considerable divergence. There were some challenges associated with the use of the country PIs as co-supervisors. Doctoral student progress was at times impeded by delays in the release of funding instalments from the EU. The paper provides a checklist of essential requirements and a set of recommendations for effective nesting of doctoral students in joint North–South projects. Conclusion There are considerable challenges to the effective nesting of doctoral students within major collaborative

  8. Dynamics of Information Systems

    CERN Document Server

    Hirsch, Michael J; Murphey, Robert

    2010-01-01

    Our understanding of information and information dynamics has outgrown classical information theory. This book presents the research explaining the importance of information in the evolution of a distributed or networked system. It presents techniques for measuring the value or significance of information within the context of a system

  9. Children and their parents assessing the doctor-patient interaction: a rating system for doctors' communication skills.

    Science.gov (United States)

    Crossley, Jim; Eiser, Christine; Davies, Helena A

    2005-08-01

    Only a patient and his or her family can judge many of the most important aspects of the doctor-patient interaction. This study evaluates the feasibility and reliability of children and their families assessing the quality of paediatricians' interactions using a rating instrument developed specifically for this purpose. A reliability analysis using generalisability theory on the ratings from 352 doctor-patient interactions across different speciality clinics. Ratings were normally distributed. They were highest for 'overall' performance, and lowest for giving time to discuss the families' agenda. An appropriate sample of adults' ratings provided a reliable score (G = 0.7 with 15 raters), but children's ratings were too idiosyncratic to be reproducible (G = 0.36 with 15 raters). CONCLUSIONS AND FURTHER WORK: Accompanying adults can provide reliable ratings of doctors' interactions with children. Because an adult is usually present at the consultation their ratings provide a highly feasible and authentic approach. Sampling doctors' interactions from different clinics and with patients of both genders provides a universal picture of performance. The method is ideal to measure performance for in-training assessment or revalidation. Further work is in progress to evaluate the educational impact of feeding ratings back to the doctors being assessed, and their use in a range of clinical contexts.

  10. Complexity in Dynamical Systems

    Science.gov (United States)

    Moore, Cristopher David

    The study of chaos has shown us that deterministic systems can have a kind of unpredictability, based on a limited knowledge of their initial conditions; after a finite time, the motion appears essentially random. This observation has inspired a general interest in the subject of unpredictability, and more generally, complexity; how can we characterize how "complex" a dynamical system is?. In this thesis, we attempt to answer this question with a paradigm of complexity that comes from computer science, we extract sets of symbol sequences, or languages, from a dynamical system using standard methods of symbolic dynamics; we then ask what kinds of grammars or automata are needed a generate these languages. This places them in the Chomsky heirarchy, which in turn tells us something about how subtle and complex the dynamical system's behavior is. This gives us insight into the question of unpredictability, since these automata can also be thought of as computers attempting to predict the system. In the culmination of the thesis, we find a class of smooth, two-dimensional maps which are equivalent to the highest class in the Chomsky heirarchy, the turning machine; they are capable of universal computation. Therefore, these systems possess a kind of unpredictability qualitatively different from the usual "chaos": even if the initial conditions are known exactly, questions about the system's long-term dynamics are undecidable. No algorithm exists to answer them. Although this kind of unpredictability has been discussed in the context of distributed, many-degree-of -freedom systems (for instance, cellular automata) we believe this is the first example of such phenomena in a smooth, finite-degree-of-freedom system.

  11. System dynamics with interaction discontinuity

    CERN Document Server

    Luo, Albert C J

    2015-01-01

    This book describes system dynamics with discontinuity caused by system interactions and presents the theory of flow singularity and switchability at the boundary in discontinuous dynamical systems. Based on such a theory, the authors address dynamics and motion mechanism of engineering discontinuous systems due to interaction. Stability and bifurcations of fixed points in nonlinear discrete dynamical systems are presented, and mapping dynamics are developed for analytical predictions of periodic motions in engineering discontinuous dynamical systems. Ultimately, the book provides an alternative way to discuss the periodic and chaotic behaviors in discontinuous dynamical systems.

  12. Turbulence and Dynamical Systems.

    Science.gov (United States)

    1984-12-31

    Dynamical Systems 16. ASBTRACT (Continue on reverse if nemcry and idinitiy by block number) Abstract enclosed. See page 7. iyD, C FILE COZY ... 20... mysterious long-time f behavior of the Euler equation in fluid mechanics. The talk Final Report - APOSR page 2 of C. Schwarz on liquid helium showed to

  13. Controlling Uncertain Dynamical Systems

    Indian Academy of Sciences (India)

    ... Mid Year Meetings · Discussion Meetings · Public Lectures · Lecture Workshops · Refresher Courses · Symposia · Live Streaming. Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 9. Controlling Uncertain Dynamical Systems - Basic Ideas of Adaptive Control. N Ananthkrishnan Rashi Bansal.

  14. Butschli Dynamic Droplet System

    DEFF Research Database (Denmark)

    Armstrong, R.; Hanczyc, M.

    2013-01-01

    Dynamical oil-water systems such as droplets display lifelike properties and may lend themselves to chemical programming to perform useful work, specifically with respect to the built environment. We present Butschli water-in-oil droplets as a model for further investigation into the development ...

  15. Emergence in Dynamical Systems

    Directory of Open Access Journals (Sweden)

    John Collier

    2013-12-01

    Full Text Available Emergence is a term used in many contexts in current science; it has become fashionable. It has a traditional usage in philosophy that started in 1875 and was expanded by J. S. Mill (earlier, under a different term and C. D. Broad. It is this form of emergence that I am concerned with here. I distinguish it from uses like ‘computational emergence,’ which can be reduced to combinations of program steps, or its application to merely surprising new features that appear in complex combinations of parts. I will be concerned specifically with ontological emergence that has the logical properties required by Mill and Broad (though there might be some quibbling about the details of their views. I restrict myself to dynamical systems that are embodied in processes. Everything that we can interact with through sensation or action is either dynamical or can be understood in dynamical terms, so this covers all comprehensible forms of emergence in the strong (nonreducible sense I use. I will give general dynamical conditions that underlie the logical conditions traditionally assigned to emergence in nature.The advantage of this is that, though we cannot test logical conditions directly, we can test dynamical conditions. This gives us an empirical and realistic form of emergence, contrary those who say it is a matter of perspective.

  16. Interactive Dynamic-System Simulation

    CERN Document Server

    Korn, Granino A

    2010-01-01

    Showing you how to use personal computers for modeling and simulation, Interactive Dynamic-System Simulation, Second Edition provides a practical tutorial on interactive dynamic-system modeling and simulation. It discusses how to effectively simulate dynamical systems, such as aerospace vehicles, power plants, chemical processes, control systems, and physiological systems. Written by a pioneer in simulation, the book introduces dynamic-system models and explains how software for solving differential equations works. After demonstrating real simulation programs with simple examples, the author

  17. Solar System Dynamics

    Science.gov (United States)

    Wisdom, Jack

    2002-01-01

    In these 18 years, the research has touched every major dynamical problem in the solar system, including: the effect of chaotic zones on the distribution of asteroids, the delivery of meteorites along chaotic pathways, the chaotic motion of Pluto, the chaotic motion of the outer planets and that of the whole solar system, the delivery of short period comets from the Kuiper belt, the tidal evolution of the Uranian arid Galilean satellites, the chaotic tumbling of Hyperion and other irregular satellites, the large chaotic variations of the obliquity of Mars, the evolution of the Earth-Moon system, and the resonant core- mantle dynamics of Earth and Venus. It has introduced new analytical and numerical tools that are in widespread use. Today, nearly every long-term integration of our solar system, its subsystems, and other solar systems uses algorithms that was invented. This research has all been primarily Supported by this sequence of PGG NASA grants. During this period published major investigations of tidal evolution of the Earth-Moon system and of the passage of the Earth and Venus through non-linear core-mantle resonances were completed. It has published a major innovation in symplectic algorithms: the symplectic corrector. A paper was completed on non-perturbative hydrostatic equilibrium.

  18. A template-based computerized instruction entry system helps the comunication between doctors and nurses.

    Science.gov (United States)

    Takeda, Toshihiro; Mihara, Naoki; Nakagawa, Rie; Manabe, Shiro; Shimai, Yoshie; Teramoto, Kei; Matsumura, Yasushi

    2015-01-01

    In a hospital, doctors and nurses shares roles in treating admitted patients. Communication between them is necessary and communication errors become the problem in medical safety. In Japan, verbal instruction is prohibited and doctors write their instruction on paper instruction slips. However, because it is difficult to ascertain revision history and the active instructions on instruction slips, human errors can occur. We developed template-based computerized instruction entry system to reduce ward workloads and contribute to medical safety. Templates enable us to input the instructions easily and standardize the descriptions of instructions. By standardizing and combine the instruction into one template for one instruction item, the systems could prevent instructions overlap. We created sets of templates (e.g., admission set, preoperative set), so that doctors could enter their instructions easily. Instructions entered via any of the sets can be subdivided into separate items by the system before being submitted, and can also be changed on a per-item basis. The instructions were displayed as calendar form. Calendar form represents the instruction shift and current active instructions. We prepared 382 standardized instruction templates. In our system, 66% of instructions were entered via templates, and 34% were entered as free-text comments. Our system prevents communication errors between medical staff.

  19. The Impact of Doctoral Study on Educational Leaders' Work for Students' Participation in Education Systems and Society

    Science.gov (United States)

    Taysum, Alison

    2013-01-01

    This paper examines ways educational leaders engaging with doctoral research have worked for students' participation in education systems. Twenty-four interviews were conducted with educational leaders of schools, colleges, and districts in England and the US doing doctoral research. The findings reveal that the leaders identify US and English…

  20. [Loading, volumes, kinds and structure of work of doctors-dental-surgeons working in system of obligatory medical insurance].

    Science.gov (United States)

    Boĭkov, V I

    2011-01-01

    The message concerns problems of calculation of loading of doctors-dental-surgeons, their structures of work. "The Korolevskaya dental polyclinic" is offered to carry out on example STPE the analysis of loading, volumes, kinds and structure of work of the doctors-dental-surgeons working in system OMI.

  1. Cost incentives for doctors

    DEFF Research Database (Denmark)

    Schottmüller, Christoph

    2013-01-01

    If doctors take the costs of treatment into account when prescribing medication, their objectives differ from their patients' objectives because the patients are insured. This misalignment of interests hampers communication between patient and doctor. Giving cost incentives to doctors increases...... welfare if (i) the doctor's examination technology is sufficiently good or (ii) (marginal) costs of treatment are high enough. If the planner can costlessly choose the extent to which doctors take costs into account, he will opt for less than 100%. Optimal health care systems should implement different...... degrees of cost incentives depending on type of disease and/or doctor....

  2. Promoting Interdisciplinary Education: The Vienna Doctoral Programme on Water Resource Systems

    Science.gov (United States)

    Blöschl, Günter; Bucher, Christian; Carr, Gemma; Farnleitner, Andreas; Rechberger, Helmut; Wagner, Wolfgang; Zessner, Matthias

    2010-05-01

    An interdisciplinary approach is often described as a valuable strategy to assist in overcoming the existing and emerging challenges to water resource management. The development of educational approaches to instil a culture of interdisciplinarity in the future generation of water resource professionals will help to meet this strategic need. The Vienna Doctoral Programme on Water Resource Systems demonstrates how the adoption of an interdisciplinary education framework has been applied to a graduate programme in the water sciences. The interdisciplinary approach aims to provide doctoral research students with an understanding of the wide spectrum of processes relevant to water resource systems. This will enable them to bring together a range of ideas, strategies and methods to their current research and future careers. The education programme also aims to teach the softer skills required for successful interdisciplinary work such as the ability to communicate clearly with non-specialist professionals and the capacity to listen to and accommodate suggestions from experts in different disciplines, which have often not traditionally been grouped together. The Vienna Doctoral Programme achieves these aims through teaching an appreciation for a wide variety of approaches including laboratory analysis, field studies and numerical methods across the fields of hydrology, remote sensing, hydrogeology, structural mechanics, microbiology, water quality and resource management. Teaching takes the form of a detailed study programme on topics such as socio-economic concepts, resource and river basin management, modelling and simulation methods, health related water quality targets, urban water management, spatial data from remote sensing and basics for stochastic mechanics. Courses are also held by internationally recognised top scientists, and a guest scientist seminar series allows doctoral researchers to profit from the expertise of senior researchers from around the world

  3. Cosmological dynamical systems

    CERN Document Server

    Leon, Genly

    2011-01-01

    In this book are studied, from the perspective of the dynamical systems, several Universe models. In chapter 1 we give a bird's eye view on cosmology and cosmological problems. Chapter 2 is devoted to a brief review on some results and useful tools from the qualitative theory of dynamical systems. They provide the theoretical basis for the qualitative study of concrete cosmological models. Chapters 1 and 2 are a review of well-known results. Chapters 3, 4, 5 and 6 are devoted to our main results. In these chapters are extended and settled in a substantially different, more strict mathematical language, several results obtained by one of us in arXiv:0812.1013 [gr-qc]; arXiv:1009.0689 [gr-qc]; arXiv:0904.1577[gr-qc]; and arXiv:0909.3571 [hep-th]. In chapter 6, we provide a different approach to the subject discussed in astro-ph/0503478. Additionally, we perform a Poincar\\'e compactification process allowing to construct a global phase space containing all the cosmological information in both finite and infinite...

  4. Dynamics of stochastic systems

    CERN Document Server

    Klyatskin, Valery I

    2005-01-01

    Fluctuating parameters appear in a variety of physical systems and phenomena. They typically come either as random forces/sources, or advecting velocities, or media (material) parameters, like refraction index, conductivity, diffusivity, etc. The well known example of Brownian particle suspended in fluid and subjected to random molecular bombardment laid the foundation for modern stochastic calculus and statistical physics. Other important examples include turbulent transport and diffusion of particle-tracers (pollutants), or continuous densities (''''oil slicks''''), wave propagation and scattering in randomly inhomogeneous media, for instance light or sound propagating in the turbulent atmosphere.Such models naturally render to statistical description, where the input parameters and solutions are expressed by random processes and fields.The fundamental problem of stochastic dynamics is to identify the essential characteristics of system (its state and evolution), and relate those to the input parameters of ...

  5. A pay-for-performance system for civil service doctors: the Indonesian experiment.

    Science.gov (United States)

    Chernichovsky, D; Bayulken, C

    1995-07-01

    In 1980 the Government of Indonesia proposed the introduction of a pay-for-performance system, the Functional Position System (FPS), for certain occupational categories of civil servants to provide a career development path and stimulate productivity (Government of Indonesia. Government Ordinance No. 3, 1980 Concerning Appointment to Civil Service Rank. Jakarta, 1980). The FPS, a bold pay concept in the civil service, links pay to skills and performance. In 1987, instructions were issued for doctors to be included in the system (Government of Indonesia, Credit Scores for Doctors. Circular Issued by the Ministry of Health and the Agency for Administration of the Civil Service No. 614/MENKES/E/VIII/1987 and No. 16/SE/1987). In this paper we evaluate how well the system-which in principle could be applicable to both developed and developing economies--can meet its stated objectives for Indonesian doctors working in the community, and for Indonesian health policy objectives as stated in the country's last five-year development plan "Repelita V" (Government of Indonesia. The Fifth Five-year Development Plan (Repelita V) 1989-1994. Jakarta, Indonesia, 1989). The FPS is particularly innovative in the Indonesian environment where wages are low and comparatively uniform, reflecting a philosophy of 'shared poverty', and vary primarily by seniority. The FPS has, however, several conceptual and practical shortcomings. The design of the reward system disregards effort or time inputs, as well as other inputs needed per unit of reward. Consequently, the FPS can not be used as an effective incentive system promoting professional excellence and health policy objectives. Practically, the system hardly provides an effective alternative for career development among community physicians.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. 2nd International Doctoral Symposium on Applied Computation and Security Systems

    CERN Document Server

    Cortesi, Agostino; Saeed, Khalid; Chaki, Nabendu

    2016-01-01

    The book contains the extended version of the works that have been presented and discussed in the Second International Doctoral Symposium on Applied Computation and Security Systems (ACSS 2015) held during May 23-25, 2015 in Kolkata, India. The symposium has been jointly organized by the AGH University of Science & Technology, Cracow, Poland; Ca’ Foscari University, Venice, Italy and University of Calcutta, India. The book is divided into volumes and presents dissertation works in the areas of Image Processing, Biometrics-based Authentication, Soft Computing, Data Mining, Next Generation Networking and Network Security, Remote Healthcare, Communications, Embedded Systems, Software Engineering and Service Engineering.

  7. A Substantive Medical Education System for Students and Doctors in Collaboration with Obstetricians and Gynecologist, and Pediatricians

    OpenAIRE

    金子, 政時; Masatoki, KANEKO; 宮崎大学医学部医学教育改革推進センター,産婦人科; Department of Obstetrics and Gynecology, Center for Medical Education, Faculty of Medicine, University of Miyazaki

    2008-01-01

    A substantive medical education system is very important for training young and talented doctors in order to avoid shortage of specialists in the field of obstetrics and gynecology. Before the establishment of a substantive medical education system in Miyazaki prefecture, the prefecture had the highest perinatal mortality rate in Japan. In order to overcome this situation, we began to educate the young and talented doctors who specialized in obstetrics and gynecology. As a result of this prog...

  8. Burnout and Doctors: Prevalence, Prevention and Intervention

    Directory of Open Access Journals (Sweden)

    Shailesh Kumar

    2016-06-01

    Full Text Available Doctors are exposed to high levels of stress in the course of their profession and are particularly susceptible to experiencing burnout. Burnout has far-reaching implications on doctors; patients and the healthcare system. Doctors experiencing burnout are reported to be at a higher risk of making poor decisions; display hostile attitude toward patients; make more medical errors; and have difficult relationships with co-workers. Burnout among doctors also increases risk of depression; anxiety; sleep disturbances; fatigue; alcohol and drug misuse; marital dysfunction; premature retirement and perhaps most seriously suicide. Sources of stress in medical practice may range from the emotions arising in the context of patient care to the environment in which doctors practice. The extent of burnout may vary depending on the practice setting; speciality and changing work environment. Understanding dynamic risk factors associated with burnout may help us develop strategies for preventing and treating burnout. Some of these strategies will be reviewed in this paper.

  9. Burnout and Doctors: Prevalence, Prevention and Intervention.

    Science.gov (United States)

    Kumar, Shailesh

    2016-06-30

    Doctors are exposed to high levels of stress in the course of their profession and are particularly susceptible to experiencing burnout. Burnout has far-reaching implications on doctors; patients and the healthcare system. Doctors experiencing burnout are reported to be at a higher risk of making poor decisions; display hostile attitude toward patients; make more medical errors; and have difficult relationships with co-workers. Burnout among doctors also increases risk of depression; anxiety; sleep disturbances; fatigue; alcohol and drug misuse; marital dysfunction; premature retirement and perhaps most seriously suicide. Sources of stress in medical practice may range from the emotions arising in the context of patient care to the environment in which doctors practice. The extent of burnout may vary depending on the practice setting; speciality and changing work environment. Understanding dynamic risk factors associated with burnout may help us develop strategies for preventing and treating burnout. Some of these strategies will be reviewed in this paper.

  10. Synchronization dynamics of two different dynamical systems

    International Nuclear Information System (INIS)

    Luo, Albert C.J.; Min Fuhong

    2011-01-01

    Highlights: → Synchronization dynamics of two distinct dynamical systems. → Synchronization, de-synchronization and instantaneous synchronization. → A controlled pendulum synchronizing with the Duffing oscillator. → Synchronization invariant set. → Synchronization parameter map. - Abstract: In this paper, synchronization dynamics of two different dynamical systems is investigated through the theory of discontinuous dynamical systems. The necessary and sufficient conditions for the synchronization, de-synchronization and instantaneous synchronization (penetration or grazing) are presented. Using such a synchronization theory, the synchronization of a controlled pendulum with the Duffing oscillator is systematically discussed as a sampled problem, and the corresponding analytical conditions for the synchronization are presented. The synchronization parameter study is carried out for a better understanding of synchronization characteristics of the controlled pendulum and the Duffing oscillator. Finally, the partial and full synchronizations of the controlled pendulum with periodic and chaotic motions are presented to illustrate the analytical conditions. The synchronization of the Duffing oscillator and pendulum are investigated in order to show the usefulness and efficiency of the methodology in this paper. The synchronization invariant domain is obtained. The technique presented in this paper should have a wide spectrum of applications in engineering. For example, this technique can be applied to the maneuvering target tracking, and the others.

  11. Algebraic Structure of Dynamical Systems

    Science.gov (United States)

    2017-05-22

    dynamical system is a function based upon a finite window size of a sequence. Suppose we have a function ϕ which we know is a symmetry of a system (X...this finite window , we can determine what ϕ(x)i is. Example 4.3. Let (X, T ) be a symbolic dynamical system . Let x = . . . 011011110001 . . .. Suppose...the centralizer of any dynamical system is a group with the operation of composition. Given a dynamical system (X, T ) acted on by Z we say that the

  12. Dynamic Modeling of ALS Systems

    Science.gov (United States)

    Jones, Harry

    2002-01-01

    The purpose of dynamic modeling and simulation of Advanced Life Support (ALS) systems is to help design them. Static steady state systems analysis provides basic information and is necessary to guide dynamic modeling, but static analysis is not sufficient to design and compare systems. ALS systems must respond to external input variations and internal off-nominal behavior. Buffer sizing, resupply scheduling, failure response, and control system design are aspects of dynamic system design. We develop two dynamic mass flow models and use them in simulations to evaluate systems issues, optimize designs, and make system design trades. One model is of nitrogen leakage in the space station, the other is of a waste processor failure in a regenerative life support system. Most systems analyses are concerned with optimizing the cost/benefit of a system at its nominal steady-state operating point. ALS analysis must go beyond the static steady state to include dynamic system design. All life support systems exhibit behavior that varies over time. ALS systems must respond to equipment operating cycles, repair schedules, and occasional off-nominal behavior or malfunctions. Biological components, such as bioreactors, composters, and food plant growth chambers, usually have operating cycles or other complex time behavior. Buffer sizes, material stocks, and resupply rates determine dynamic system behavior and directly affect system mass and cost. Dynamic simulation is needed to avoid the extremes of costly over-design of buffers and material reserves or system failure due to insufficient buffers and lack of stored material.

  13. Chaos for Discrete Dynamical System

    Directory of Open Access Journals (Sweden)

    Lidong Wang

    2013-01-01

    Full Text Available We prove that a dynamical system is chaotic in the sense of Martelli and Wiggins, when it is a transitive distributively chaotic in a sequence. Then, we give a sufficient condition for the dynamical system to be chaotic in the strong sense of Li-Yorke. We also prove that a dynamical system is distributively chaotic in a sequence, when it is chaotic in the strong sense of Li-Yorke.

  14. Promoting interdisciplinary education - the Vienna Doctoral Programme on Water Resource Systems

    Science.gov (United States)

    Blöschl, G.; Carr, G.; Bucher, C.; Farnleitner, A. H.; Rechberger, H.; Wagner, W.; Zessner, M.

    2012-02-01

    The Vienna Doctoral Programme on Water Resource Systems (DK-WRS) is a programme that aims to educate students in interdisciplinary water science through cutting edge research at an international level. It is funded by the Austrian Science Fund and designed to run over a period of 12 yr during which 80 doctoral students are anticipated to graduate. This paper reports on our experiences of setting up and implementing the Programme. We identify three challenges: integrating the disciplines, maintaining depth in an interdisciplinary programme, and teaching subjects remote to each student's core expertise. To address these challenges we adopt a number of approaches. We use three levels of instruments to foster integration across the disciplines: joint groups (e.g. a joint study programme), joint science questions (e.g. developed in annual symposia), and joint study sites. To maintain depth we apply a system of quality control including regular feedback sessions, theses by journal publications and international study exchange. For simultaneously teaching students from civil and environmental engineering, biology, geology, chemistry, mathematics we use visually explicit teaching, learning by doing, extra mentoring and by cross relating associated subjects. Our initial assessment of the Programme shows some very positive outcomes. Joint science questions formed between students from various disciplines indicate integration is being achieved. The number of successful publications in top journals suggests that depth is maintained. Positive feedback from the students on the variety and clarity of the courses indicates the teaching strategy is working well. Our experiences have shown that implementing and running an interdisciplinary doctoral programme has its challenges and is demanding in terms of time and human resources but seeing interactions progress and watching people grow and develop their way of thinking in an interdisciplinary environment is a valuable reward.

  15. Promoting interdisciplinary education − the Vienna Doctoral Programme on Water Resource Systems

    Directory of Open Access Journals (Sweden)

    W. Wagner

    2012-02-01

    Full Text Available The Vienna Doctoral Programme on Water Resource Systems (DK-WRS is a programme that aims to educate students in interdisciplinary water science through cutting edge research at an international level. It is funded by the Austrian Science Fund and designed to run over a period of 12 yr during which 80 doctoral students are anticipated to graduate. This paper reports on our experiences of setting up and implementing the Programme. We identify three challenges: integrating the disciplines, maintaining depth in an interdisciplinary programme, and teaching subjects remote to each student's core expertise. To address these challenges we adopt a number of approaches. We use three levels of instruments to foster integration across the disciplines: joint groups (e.g. a joint study programme, joint science questions (e.g. developed in annual symposia, and joint study sites. To maintain depth we apply a system of quality control including regular feedback sessions, theses by journal publications and international study exchange. For simultaneously teaching students from civil and environmental engineering, biology, geology, chemistry, mathematics we use visually explicit teaching, learning by doing, extra mentoring and by cross relating associated subjects. Our initial assessment of the Programme shows some very positive outcomes. Joint science questions formed between students from various disciplines indicate integration is being achieved. The number of successful publications in top journals suggests that depth is maintained. Positive feedback from the students on the variety and clarity of the courses indicates the teaching strategy is working well. Our experiences have shown that implementing and running an interdisciplinary doctoral programme has its challenges and is demanding in terms of time and human resources but seeing interactions progress and watching people grow and develop their way of thinking in an interdisciplinary environment is a

  16. The implementation of a call-back system reduces the doctor's workload, and improves accessibility by telephone in general practice

    OpenAIRE

    de Groot, R.A.; de Haan, J.; Bosveld, H.E.P.; Nijland, Albert; Meyboom-de Jong, B.

    2002-01-01

    Background. In a general practice in The Netherlands, the demand for direct telephone consultation with the doctor became extreme, which resulted in poorly managed consultations, and poor telephone access due to busy lines. A call- back telephone appointment system was therefore introduced: all calls are answered and, when possible, managed by the practice assistant. If the assistant feels incapable, or if the patient prefers to speak to the doctor, a telephone appointment is scheduled, at wh...

  17. Improved interobserver variation after training of doctors in the Neer system. A randomised trial

    DEFF Research Database (Denmark)

    Brorson, S; Bagger, J; Sylvest, A

    2002-01-01

    We investigated whether training doctors to classify proximal fractures of the humerus according to the Neer system could improve interobserver agreement. Fourteen doctors were randomised to two training sessions, or to no training, and asked to categorise 42 unselected pairs of plain radiographs...... of fractures of the proximal humerus according to the Neer system. The mean kappa difference between the training and control groups was 0.30 (95% CI 0.10 to 0.50, p = 0.006). In the training group the mean kappa value for interobserver variation improved from 0.27 (95% CI 0.24 to 0.31) to 0.62 (95% CI 0.......57 to 0.67). The improvement was particularly notable for specialists in whom kappa increased from 0.30 (95% CI 0.23 to 0.37) to 0.79 (95% CI 0.70 to 0.88). These results suggest that formal training in the Neer system is a prerequisite for its use in clinical practice and research....

  18. Management of complex dynamical systems

    Science.gov (United States)

    MacKay, R. S.

    2018-02-01

    Complex dynamical systems are systems with many interdependent components which evolve in time. One might wish to control their trajectories, but a more practical alternative is to control just their statistical behaviour. In many contexts this would be both sufficient and a more realistic goal, e.g. climate and socio-economic systems. I refer to it as ‘management’ of complex dynamical systems. In this paper, some mathematics for management of complex dynamical systems is developed in the weakly dependent regime, and questions are posed for the strongly dependent regime.

  19. Controlling Uncertain Dynamical Systems

    Indian Academy of Sciences (India)

    Author Affiliations. N Ananthkrishnan1 Rashi Bansal2. Head, CAE Analysis & Design Zeus Numerix Pvt Ltd. M-03, SINE, IIT Bombay Powai Mumbai 400076, India. MTech (Aerospace Engineering) with specialization in Dynamics & Control from IIT Bombay.

  20. 3rd International Doctoral Symposium on Applied Computation and Security Systems

    CERN Document Server

    Saeed, Khalid; Cortesi, Agostino; Chaki, Nabendu

    2017-01-01

    This book presents extended versions of papers originally presented and discussed at the 3rd International Doctoral Symposium on Applied Computation and Security Systems (ACSS 2016) held from August 12 to 14, 2016 in Kolkata, India. The symposium was jointly organized by the AGH University of Science & Technology, Cracow, Poland; Ca’ Foscari University, Venice, Italy; and the University of Calcutta, India. The book is divided into two volumes, Volumes 3 and 4, and presents dissertation works in the areas of Image Processing, Biometrics-based Authentication, Soft Computing, Data Mining, Next-Generation Networking and Network Security, Remote Healthcare, Communications, Embedded Systems, Software Engineering and Service Engineering. The first two volumes of the book published the works presented at the ACSS 2015, which was held from May 23 to 25, 2015 in Kolkata, India.

  1. Ergodic theory and dynamical systems

    CERN Document Server

    Coudène, Yves

    2016-01-01

    This textbook is a self-contained and easy-to-read introduction to ergodic theory and the theory of dynamical systems, with a particular emphasis on chaotic dynamics. This book contains a broad selection of topics and explores the fundamental ideas of the subject. Starting with basic notions such as ergodicity, mixing, and isomorphisms of dynamical systems, the book then focuses on several chaotic transformations with hyperbolic dynamics, before moving on to topics such as entropy, information theory, ergodic decomposition and measurable partitions. Detailed explanations are accompanied by numerous examples, including interval maps, Bernoulli shifts, toral endomorphisms, geodesic flow on negatively curved manifolds, Morse-Smale systems, rational maps on the Riemann sphere and strange attractors. Ergodic Theory and Dynamical Systems will appeal to graduate students as well as researchers looking for an introduction to the subject. While gentle on the beginning student, the book also contains a number of commen...

  2. Dynamical systems in classical mechanics

    CERN Document Server

    Kozlov, V V

    1995-01-01

    This book shows that the phenomenon of integrability is related not only to Hamiltonian systems, but also to a wider variety of systems having invariant measures that often arise in nonholonomic mechanics. Each paper presents unique ideas and original approaches to various mathematical problems related to integrability, stability, and chaos in classical dynamics. Topics include… the inverse Lyapunov theorem on stability of equilibria geometrical aspects of Hamiltonian mechanics from a hydrodynamic perspective current unsolved problems in the dynamical systems approach to classical mechanics

  3. Reasoning about Dynamic Normative Systems

    NARCIS (Netherlands)

    Knobbout, Max; Dastani, Mehdi; Meyer, John-Jules Charles

    2014-01-01

    The use of normative systems is widely accepted as an effective approach to control and regulate the behaviour of agents in multiagent systems. When norms are added to a normative system, the behaviour of such a system changes. As of yet, there is no clear formal methodology to model the dynamics of

  4. Dynamic Systems and Software

    DEFF Research Database (Denmark)

    Thomsen, Per Grove

    1996-01-01

    A one-dimensional model with axial discretization of engine components has been formulated using tha balance equations for mass energy and momentum and the ideal gas equation of state. ODE's that govern the dynamic behaviour of the regenerator matrix temperatures are included in the model. Known...

  5. Development of a Probabilistic Technique for On-line Parameter and State Estimation in Non-linear Dynamic Systems

    International Nuclear Information System (INIS)

    Tunc Aldemir; Miller, Don W.; Hajek, Brian K.; Peng Wang

    2002-01-01

    The DSD (Dynamic System Doctor) is a system-independent, interactive software under development for on-line state/parameter estimation in dynamic systems (1), partially supported through a Nuclear Engineering Education (NEER) grant during 1998-2001. This paper summarizes the recent accomplishments in improving the user-friendliness and computational capability of DSD

  6. Health system reforms, violence against doctors and job satisfaction in the medical profession: a cross-sectional survey in Zhejiang Province, Eastern China.

    Science.gov (United States)

    Wu, Dan; Wang, Yun; Lam, Kwok Fai; Hesketh, Therese

    2014-12-31

    To explore the factors influencing doctors' job satisfaction and morale in China, in the context of the ongoing health system reforms and the deteriorating doctor-patient relationship. Cross-sectional survey using self-completion questionnaires. The survey was conducted from March to May 2012 among doctors at the provincial, county and primary care levels in Zhejiang Province, China. The questionnaire was completed by 202 doctors. Factors which contributed most to low job satisfaction were low income and long working hours. Provincial level doctors were most dissatisfied while primary care doctors were the least dissatisfied. Three per cent of doctors at high-level hospitals and 27% of those in primary care were satisfied with the salary. Only 7% at high-level hospitals were satisfied with the work hours, compared to 43% in primary care. Less than 10% at high levels were satisfied with the amount of paid vacation time (3%) and paid sick leave (5%), compared with 38% and 41%, respectively, in primary care. Overall, 87% reported that patients were more likely to sue and that patient violence against doctors was increasing. Only 4.5% wanted their children to be doctors. Of those 125 who provided a reason, 34% said poor pay, 17% said it was a high-risk profession, and 9% expressed concerns about personal insecurity or patient violence. Doctors have low job satisfaction overall. Recruitment and retention of doctors have become major challenges for the Chinese health system. Measures must be taken to address this, in order to ensure recruitment and retention of doctors in the future. These measures must first include reduction of doctors' workload, especially at provincial hospitals, partly through incentivisation of appropriate utilisation of primary care, increase in doctors' salary and more effective measures to tackle patient violence against doctors. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence

  7. Permutation Complexity in Dynamical Systems

    CERN Document Server

    Amigo, Jose

    2010-01-01

    The study of permutation complexity can be envisioned as a new kind of symbolic dynamics whose basic blocks are ordinal patterns, that is, permutations defined by the order relations among points in the orbits of dynamical systems. Since its inception in 2002 the concept of permutation entropy has sparked a new branch of research in particular regarding the time series analysis of dynamical systems that capitalizes on the order structure of the state space. Indeed, on one hand ordinal patterns and periodic points are closely related, yet ordinal patterns are amenable to numerical methods, while periodicity is not. Another interesting feature is that since it can be shown that random (unconstrained) dynamics has no forbidden patterns with probability one, their existence can be used as a fingerprint to identify any deterministic origin of orbit generation. This book is primarily addressed to researchers working in the field of nonlinear dynamics and complex systems, yet will also be suitable for graduate stude...

  8. Improving doctor-patient communication: content validity examination of a novel urinary system-simulating physical model.

    Science.gov (United States)

    Hu, WenGang; Song, YaJun; Zhong, Xiao; Feng, JiaYu; Wang, PingXian; Huang, ChiBing

    2016-01-01

    Effective doctor-patient communication is essential for establishing a successful doctor-patient relationship and implementing high-quality health care. In this study, a novel urinary system-simulating physical model was designed and fabricated, and its content validity for improving doctor-patient communication was examined by conducting a randomized controlled trial in which this system was compared with photographs. A total of 240 inpatients were randomly selected and assigned to six doctors for treatment. After primary diagnosis and treatment had been determined, these patients were randomly divided into the experimental group and the control group. Patients in the experimental group participated in model-based doctor-patient communication, whereas control group patients received picture-based communication. Within 30 min after this communication, a Demographic Information Survey Scale and a Medical Interview Satisfaction Scale (MISS) were distributed to investigate patients' demographic characteristics and their assessments of total satisfaction, distress relief, communication comfort, rapport, and compliance intent. The study results demonstrated that the individual groups were comparable with respect to demographic variables but that relative to patients in the picture-based communication group, patients in the model-based communication group had significantly higher total satisfaction scores and higher ratings for distress relief, communication comfort, rapport, and compliance intent. These results indicate that the physical model is more effective than the pictures at improving doctor-patient communication and patient outcomes. The application of the physical model in doctor-patient communication is helpful and valuable and therefore merits widespread clinical popularization.

  9. MADNESS AND METHOD: THE SYSTEM OF DOCTOR TARR AND PROFESSOR FETHER

    Directory of Open Access Journals (Sweden)

    Luciane Alves Santos

    2014-12-01

    Full Text Available The present study aims to discuss the theme of madness, comparing the narrator’s perspective in “The System of Doctor Tarr and Professor Fether” (1845 and another short stories by Edgar Allan Poe. The analysis illustrates that science in the 19th century aims to remove the fear of the unknown, dominating the natural world and its laws; and that fiction, the presumptive opposite, represents an extension of the same logic under another name. Some writers denied any obligation of loyalty to scientific rationalism and tried to decipher this problem through the dream and the supernatural. Fantastic works of Gothic fiction – Hoffmann’s novels and some of Poe’s stories – illuminate these points. Poe reinterprets the Gothic in the Victorian Age, with an unnamed and often unreliable narrator that insists on his rationality. The comic and grotesque horror result of the psychology of his characters often descended into madness. 

  10. Dynamic Systems and Software

    DEFF Research Database (Denmark)

    Thomsen, Per Grove

    1996-01-01

    A one-dimensional model with axial discretization of engine components has been formulated using tha balance equations for mass energy and momentum and the ideal gas equation of state. ODE's that govern the dynamic behaviour of the regenerator matrix temperatures are included in the model. Known ...... loss mechanisms are coupled directly into the governing equations instead of applying losses as corrections to simulation results from an idealised model....

  11. Lectures on chaotic dynamical systems

    CERN Document Server

    Afraimovich, Valentin

    2002-01-01

    This book is devoted to chaotic nonlinear dynamics. It presents a consistent, up-to-date introduction to the field of strange attractors, hyperbolic repellers, and nonlocal bifurcations. The authors keep the highest possible level of "physical" intuition while staying mathematically rigorous. In addition, they explain a variety of important nonstandard algorithms and problems involving the computation of chaotic dynamics. The book will help readers who are not familiar with nonlinear dynamics to understand and appreciate sophisticated modern dynamical systems and chaos. Intended for courses in either mathematics, physics, or engineering, prerequisites are calculus, differential equations, and functional analysis.

  12. Dynamic Ocean Track System Plus -

    Data.gov (United States)

    Department of Transportation — Dynamic Ocean Track System Plus (DOTS Plus) is a planning tool implemented at the ZOA, ZAN, and ZNY ARTCCs. It is utilized by Traffic Management Unit (TMU) personnel...

  13. Distinguishing the preparation and roles of Doctor of Philosophy and Doctor of Nursing Practice graduates: national implications for academic curricula and health care systems.

    Science.gov (United States)

    Melnyk, Bernadette Mazurek

    2013-08-01

    Although the American Association of Colleges of Nursing was clear in defining the role of individuals with the Doctor of Nursing Practice (DNP) degree when it endorsed the DNP as the single-entry degree for advanced practice nurses in 2004, confusion about educational curricula to prepare DNPs continues to exist in academic programs throughout the United States. Further, health care systems are unsure about the role DNP graduates should fulfill in comparison with PhD-prepared individuals. This article discusses the importance of DNP- and PhD-prepared individuals in improving the quality of health care and the health of Americans, how best to resolve the confusion in preparation of DNP and PhD students, and the various roles DNP and PhD graduates should fulfill in real-world settings. A national call to action and future implications for research, academia, and health care settings are highlighted. Copyright 2013, SLACK Incorporated.

  14. Dynamical systems in population biology

    CERN Document Server

    Zhao, Xiao-Qiang

    2017-01-01

    This research monograph provides an introduction to the theory of nonautonomous semiflows with applications to population dynamics. It develops dynamical system approaches to various evolutionary equations such as difference, ordinary, functional, and partial differential equations, and pays more attention to periodic and almost periodic phenomena. The presentation includes persistence theory, monotone dynamics, periodic and almost periodic semiflows, basic reproduction ratios, traveling waves, and global analysis of prototypical population models in ecology and epidemiology. Research mathematicians working with nonlinear dynamics, particularly those interested in applications to biology, will find this book useful. It may also be used as a textbook or as supplementary reading for a graduate special topics course on the theory and applications of dynamical systems. Dr. Xiao-Qiang Zhao is a University Research Professor at Memorial University of Newfoundland, Canada. His main research interests involve applied...

  15. Employability Development in the Context of Doctoral Studies: Systemic Tensions and the Views of Key Stakeholders

    Science.gov (United States)

    Golovushkina, Elena; Milligan, Colin

    2013-01-01

    Although the employability of doctoral candidates has been a topic of much discussion, the views of key institutional stakeholders on the subject are little understood. In order to address this gap, this study explores the perceptions of doctoral candidates, supervisors and researcher developers through semi-structured interviews. This small-scale…

  16. Doctoral surplus?

    Science.gov (United States)

    Universities in the United States are producing about 25% more doctorates in science and engineering than the U.S. economy can absorb, according to a new study by the Rand Corporation and Stanford University's Institute for Higher Education Research. The study looked at 13 science and engineering fields, covering 210 doctorate-granting institutions and more than 1,000 educational institutions that employ people with doctorates. The study was done by Stanford Professor William Massy and Charles Goldman of Rand, with graduate students Marc Chun and Beryle Hsiao.The researchers found that supply and demand do not work in the usual way to regulate the employment market for doctoral candidates. In labor markets, when job opportunities decrease, fewer people usually seek to enter the field. In the case of Ph.D.s, however, the researchers found that neither departments nor prospective doctoral students take close accounting of the doctorate employment gap.

  17. Dynamics of control systems

    Science.gov (United States)

    Zubov, V. I.

    Papers are presented on mathematical methods for the analysis of control systems for technical plants and manufacturing processes. Particular attention is given to the mechanics of controlled space flight, the design of automatic control systems, flexible automated complexes, control applications in biomedical research, and chemical technology for the production of new types of materials.

  18. Alternative approaches for econometric analysis of panel count data using dynamic latent class models (with application to doctor visits data).

    Science.gov (United States)

    Hyppolite, Judex; Trivedi, Pravin

    2012-06-01

    Cross-sectional latent class regression models, also known as switching regressions or hidden Markov models, cannot identify transitions between classes that may occur over time. This limitation can potentially be overcome when panel data are available. For such data, we develop a sequence of models that combine features of the static cross-sectional latent class (finite mixture) models with those of hidden Markov models. We model the probability of movement between categories in terms of a Markovian structure, which links the current state with a previous state, where state may refer to the category of an individual. This article presents a suite of mixture models of varying degree of complexity and flexibility for use in a panel count data setting, beginning with a baseline model which is a two-component mixture of Poisson distribution in which latent classes are fixed and permanent. Sequentially, we extend this framework (i) to allow the mixing proportions to be smoothly varying continuous functions of time-varying covariates, (ii) to add time dependence to the benchmark model by modeling the class-indicator variable as a first-order Markov chain and (iii) to extend item (i) by making it dynamic and introducing covariate dependence in the transition probabilities. We develop and implement estimation algorithms for these models and provide an empirical illustration using 1995-1999 panel data on the number of doctor visits derived from the German Socio-Economic Panel. Copyright © 2012 John Wiley & Sons, Ltd.

  19. Self-supervised dynamical systems

    International Nuclear Information System (INIS)

    Zak, Michail

    2004-01-01

    A new type of dynamical systems which capture the interactions via information flows typical for active multi-agent systems is introduced. The mathematical formalism is based upon coupling the classical dynamical system (with random components caused by uncertainties in initial conditions as well as by Langevin forces) with the corresponding Liouville or the Fokker-Planck equations describing evolution of these uncertainties in terms of probability density. The coupling is implemented by information-based supervising forces which fundamentally change the patterns of probability evolution. It is demonstrated that the probability density can approach prescribed attractors while exhibiting such patterns as shock waves, solitons and chaos in probability space. Applications of these phenomena to information-based neural nets, expectation-based cooperation, self-programmed systems, control chaos using terminal attractors as well as to games with incomplete information, are addressed. A formal similarity between the mathematical structure of the introduced dynamical systems and quantum mechanics is discussed

  20. Nonlinear dynamics in biological systems

    CERN Document Server

    Carballido-Landeira, Jorge

    2016-01-01

    This book presents recent research results relating to applications of nonlinear dynamics, focusing specifically on four topics of wide interest: heart dynamics, DNA/RNA, cell mobility, and proteins. The book derives from the First BCAM Workshop on Nonlinear Dynamics in Biological Systems, held in June 2014 at the Basque Center of Applied Mathematics (BCAM). At this international meeting, researchers from different but complementary backgrounds, including molecular dynamics, physical chemistry, bio-informatics and biophysics, presented their most recent results and discussed the future direction of their studies using theoretical, mathematical modeling and experimental approaches. Such was the level of interest stimulated that the decision was taken to produce this publication, with the organizers of the event acting as editors. All of the contributing authors are researchers working on diverse biological problems that can be approached using nonlinear dynamics. The book will appeal especially to applied math...

  1. The implementation of a call-back system reduces the doctor's workload, and improves accessibility by telephone in general practice

    NARCIS (Netherlands)

    de Groot, R.A.; de Haan, J.; Bosveld, H.E.P.; Nijland, Albert; Meyboom-de Jong, B.

    2002-01-01

    Background. In a general practice in The Netherlands, the demand for direct telephone consultation with the doctor became extreme, which resulted in poorly managed consultations, and poor telephone access due to busy lines. A call- back telephone appointment system was therefore introduced: all

  2. Doctor-patient communication in different European health care systems: relevance and performance from the patients' perspective.

    NARCIS (Netherlands)

    Brink-Muinen, A. van den; Verhaak, P.F.M.; Bensing, J.M.; Bahrs, O.; Deveugele, M.; Gask, L.; Leiva, F.; Mead, N.; Messerli, V.; Oppizzi, L.; Peltenburg, M.; Perez, A.

    2000-01-01

    Our aim is to investigate differences between European health care systems in the importance attached by patients to different aspects of doctor-patient communication and the GPs' performance of these aspects, both being from the patients' perspective. 3658 patients of 190 GPs in six European

  3. Dynamically reconfigurable photovoltaic system

    Science.gov (United States)

    Okandan, Murat; Nielson, Gregory N.

    2016-05-31

    A PV system composed of sub-arrays, each having a group of PV cells that are electrically connected to each other. A power management circuit for each sub-array has a communications interface and serves to connect or disconnect the sub-array to a programmable power grid. The power grid has bus rows and bus columns. A bus management circuit is positioned at a respective junction of a bus column and a bus row and is programmable through its communication interface to connect or disconnect a power path in the grid. As a result, selected sub-arrays are connected by selected power paths to be in parallel so as to produce a low system voltage, and, alternately in series so as to produce a high system voltage that is greater than the low voltage by at least a factor of ten.

  4. Nonnegative and Compartmental Dynamical Systems

    CERN Document Server

    Haddad, Wassim M; Hui, Qing

    2010-01-01

    This comprehensive book provides the first unified framework for stability and dissipativity analysis and control design for nonnegative and compartmental dynamical systems, which play a key role in a wide range of fields, including engineering, thermal sciences, biology, ecology, economics, genetics, chemistry, medicine, and sociology. Using the highest standards of exposition and rigor, the authors explain these systems and advance the state of the art in their analysis and active control design. Nonnegative and Compartmental Dynamical Systems presents the most complete treatment available o

  5. Dynamic probabilistic systems

    CERN Document Server

    Howard, Ronald A

    2007-01-01

    This book is an integrated work published in two volumes. The first volume treats the basic Markov process and its variants; the second, semi-Markov and decision processes. Its intent is to equip readers to formulate, analyze, and evaluate simple and advanced Markov models of systems, ranging from genetics and space engineering to marketing. More than a collection of techniques, it constitutes a guide to the consistent application of the fundamental principles of probability and linear system theory.Author Ronald A. Howard, Professor of Management Science and Engineering at Stanford University

  6. Controlling dynamics in diatomic systems

    Indian Academy of Sciences (India)

    Keywords. Iterative method; optimal control theory; diatomic systems; quantum control. Abstract. Controlling molecular energetics using laser pulses is exemplified for nuclear motion in two different diatomic systems. The problem of finding the optimized field for maximizing a desired quantum dynamical target is formulated ...

  7. Parametric Resonance in Dynamical Systems

    CERN Document Server

    Nijmeijer, Henk

    2012-01-01

    Parametric Resonance in Dynamical Systems discusses the phenomenon of parametric resonance and its occurrence in mechanical systems,vehicles, motorcycles, aircraft and marine craft, and micro-electro-mechanical systems. The contributors provide an introduction to the root causes of this phenomenon and its mathematical equivalent, the Mathieu-Hill equation. Also included is a discussion of how parametric resonance occurs on ships and offshore systems and its frequency in mechanical and electrical systems. This book also: Presents the theory and principles behind parametric resonance Provides a unique collection of the different fields where parametric resonance appears including ships and offshore structures, automotive vehicles and mechanical systems Discusses ways to combat, cope with and prevent parametric resonance including passive design measures and active control methods Parametric Resonance in Dynamical Systems is ideal for researchers and mechanical engineers working in application fields such as MEM...

  8. Does an activity based remuneration system attract young doctors to general practice?

    Science.gov (United States)

    Abelsen, Birgit; Olsen, Jan Abel

    2012-03-20

    The use of increasingly complex payment schemes in primary care may represent a barrier to recruiting general practitioners (GP). The existing Norwegian remuneration system is fully activity based - 2/3 fee-for-service and 1/3 capitation. Given that the system has been designed and revised in close collaborations with the medical association, it is likely to correspond - at least to some degree - with the preferences of current GPs (men in majority). The objective of this paper was to study which preferences that young doctors (women in majority), who are the potential entrants to general practice have for activity based vs. salary based payment systems. In November-December 2010 all last year medical students and all interns in Norway (n = 1.562) were invited to participate in an online survey. The respondents were asked their opinion on systems of remuneration for GPs; inclination to work as a GP; risk attitude; income preferences; work pace tolerance. The data was analysed using one-way ANOVA and multinomial logistic regression analysis. A total of 831 (53%) responded. Nearly half the sample (47%) did not consider the remuneration system to be important for their inclination to work as GP; 36% considered the current system to make general practice more attractive, while 17% considered it to make general practice less attractive. Those who are attracted by the existing system were men and those who think high income is important, while those who are deterred by the system are risk averse and less happy with a high work pace. On the question of preferred remuneration system, half the sample preferred a mix of salary and activity based remuneration (the median respondent would prefer a 50/50 mix). Only 20% preferred a fully activity based system like the existing one. A salary system was preferred by women, and those less concerned with high income, while a fully activity based system was preferred by men, and those happy with a high work pace. Given a concern

  9. Dynamic simulation of LMFBR systems

    International Nuclear Information System (INIS)

    Agrawal, A.K.; Khatib-Rahbar, M.

    1980-01-01

    This review article focuses on the dynamic analysis of liquid-metal-cooled fast breeder reactor systems in the context of protected transients. Following a brief discussion on various design and simulation approaches, a critical review of various models for in-reactor components, intermediate heat exchangers, heat transport systems and the steam generating system is presented. A brief discussion on choice of fuels as well as core and blanket system designs is also included. Numerical considerations for obtaining system-wide steady-state and transient solutions are discussed, and examples of various system transients are presented. Another area of major interest is verification of phenomenological models. Various steps involved in the code and model verification are briefly outlined. The review concludes by posing some further areas of interest in fast reactor dynamics and safety. (author)

  10. Relationships of work characteristics to job satisfaction, turnover intention, and burnout among doctors in the district public-private mixed health system of Bangladesh.

    Science.gov (United States)

    Roy, Ashim; van der Weijden, Trudy; de Vries, Nanne

    2017-06-20

    Work design integrates work characteristics having organizational, social and job components which influence employees' welfare and also organizational goals. We investigated the effects of work characteristics and other predictors to job satisfaction, turnover intention, and burnout in doctors of the public primary, public secondary and private facilities of the district health system of Bangladesh. A quantitative study using a self-administered questionnaire containing mostly structured items was conducted among the public and private doctors with a sample size of 384 from 29 out of a total 64 districts of Bangladesh during October and November 2015. All variables including work characteristics and outcomes of interest were based on literature and measured on 5-point Likert scale. Multivariate analysis of variance, bivariate correlation, and multiple regression were the models operated through SPSS version-21. A total of 354 doctors responded. No significant differences were found between public primary and secondary level doctors on combined work characteristics and outcomes variables, which however differed significantly between the public and private doctors. Organizational support was the strongest predictor adversely affecting job satisfaction, turnover intention and burnout of both the public and private doctors; private doctors' experienced more support. The effects of health-professional politics on the public doctors were alarming. Work design of the Bangladesh's health system is in need of ample development. Doing so, improvement in organizational supports is crucial; however, other work characteristics components are also important for enhancing doctors' welfare and health system productivity.

  11. Should doctors strike?

    Science.gov (United States)

    Park, John J; Murray, Scott A

    2014-05-01

    Last year in June, British doctors went on strike for the first time since 1975. Amidst a global economic downturn and with many health systems struggling with reduced finances, around the world the issue of public health workers going on strike is a very real one. Almost all doctors will agree that we should always follow the law, but often the law is unclear or does not cover a particular case. Here we must appeal to ethical discussion. The General Medical Council, in its key guidance document for practising doctors, Good Medical Practice, claims that 'Good doctors make the care of their patients their first concern'. Is this true? And if so, how is this relevant to the issue of striking? One year on since the events, we carefully reflect and argue whether it was right for doctors to pursue strike action, and call for greater discussion of ethical issues such as the recent strikes, particularly among younger members of the profession.

  12. Dynamics of Variable Mass Systems

    Science.gov (United States)

    Eke, Fidelis O.

    1998-01-01

    This report presents the results of an investigation of the effects of mass loss on the attitude behavior of spinning bodies in flight. The principal goal is to determine whether there are circumstances under which the motion of variable mass systems can become unstable in the sense that their transverse angular velocities become unbounded. Obviously, results from a study of this kind would find immediate application in the aerospace field. The first part of this study features a complete and mathematically rigorous derivation of a set of equations that govern both the translational and rotational motions of general variable mass systems. The remainder of the study is then devoted to the application of the equations obtained to a systematic investigation of the effect of various mass loss scenarios on the dynamics of increasingly complex models of variable mass systems. It is found that mass loss can have a major impact on the dynamics of mechanical systems, including a possible change in the systems stability picture. Factors such as nozzle geometry, combustion chamber geometry, propellant's initial shape, size and relative mass, and propellant location can all have important influences on the system's dynamic behavior. The relative importance of these parameters on-system motion are quantified in a way that is useful for design purposes.

  13. Kinetic Theory of Dynamical Systems

    NARCIS (Netherlands)

    Zon, R. van; Beijeren, H. van; Dorfman, J.R.

    1999-01-01

    It is generally believed that the dynamics of simple fluids can be considered to be chaotic, at least to the extent that they can be modeled as classical systems of particles interacting with short range, repulsive forces. Here we give a brief introduction to those parts of chaos theory that are

  14. Collective dynamics of multicellular systems

    Indian Academy of Sciences (India)

    simple model study reveals that cell–cell communication, system size and intrinsic cellular dynamics can lead to ... population/tissue interact, the ensemble can show a unified collective behaviour, which is not just a 'sum of the ..... Authors thank the anonymous referee for critical comments, and the Department of Science.

  15. Mass properties measurement system dynamics

    Science.gov (United States)

    Doty, Keith L.

    1993-01-01

    The MPMS mechanism possess two revolute degrees-of-freedom and allows the user to measure the mass, center of gravity, and the inertia tensor of an unknown mass. The dynamics of the Mass Properties Measurement System (MPMS) from the Lagrangian approach to illustrate the dependency of the motion on the unknown parameters.

  16. Adaptive, dynamic, and resilient systems

    CERN Document Server

    Suri, Niranjan

    2015-01-01

    As the complexity of today's networked computer systems grows, they become increasingly difficult to understand, predict, and control. Addressing these challenges requires new approaches to building these systems. Adaptive, Dynamic, and Resilient Systems supplies readers with various perspectives of the critical infrastructure that systems of networked computers rely on. It introduces the key issues, describes their interrelationships, and presents new research in support of these areas.The book presents the insights of a different group of international experts in each chapter. Reporting on r

  17. Advanced dynamics of mechanical systems

    CERN Document Server

    Cheli, Federico

    2015-01-01

    This book introduces a general approach for schematization of mechanical systems with rigid and deformable bodies. It proposes a systems approach to reproduce the interaction of the mechanical system with different force fields such as those due to the action of fluids or contact forces between bodies, i.e., with forces dependent on the system states, introducing the concepts of the stability of motion. In the first part of the text mechanical systems with one or more degrees of freedom with large motion and subsequently perturbed in the neighborhood of the steady state position are analyzed. Both discrete and continuous systems (modal approach, finite elements) are analyzed. The second part is devoted to the study of mechanical systems subject to force fields, the rotor dynamics, techniques of experimental identification of the parameters, and random excitations. The book will be especially valuable for students of engineering courses in Mechanical Systems, Aerospace, Automation, and Energy but will also b...

  18. Doctors Today

    LENUS (Irish Health Repository)

    Murphy, JFA

    2012-03-01

    Doctors’ relationship with patients and their role in society is changing. Until the 1960s doctors concentrated on the welfare of patients with less emphasis placed on patients’ rights1. Over recent decades there has been increasing empowerment of the individual across all facets of society including health care. Doctors continue to be perceived as having expertise and authority over medical science. Patients, however, now hold sway over questions of values or preferences. We all must be aware of this change in the doctor- patient interaction. We need to be more aware of the outcomes that patients view as important. The concept of shared decision-making with the patient is now widely appreciated. The process involves a change in mind set particularly for doctors who trained in an earlier era.

  19. Dynamical systems probabilistic risk assessment

    Energy Technology Data Exchange (ETDEWEB)

    Denman, Matthew R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ames, Arlo Leroy [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-03-01

    Probabilistic Risk Assessment (PRA) is the primary tool used to risk-inform nuclear power regulatory and licensing activities. Risk-informed regulations are intended to reduce inherent conservatism in regulatory metrics (e.g., allowable operating conditions and technical specifications) which are built into the regulatory framework by quantifying both the total risk profile as well as the change in the risk profile caused by an event or action (e.g., in-service inspection procedures or power uprates). Dynamical Systems (DS) analysis has been used to understand unintended time-dependent feedbacks in both industrial and organizational settings. In dynamical systems analysis, feedback loops can be characterized and studied as a function of time to describe the changes to the reliability of plant Structures, Systems and Components (SSCs). While DS has been used in many subject areas, some even within the PRA community, it has not been applied toward creating long-time horizon, dynamic PRAs (with time scales ranging between days and decades depending upon the analysis). Understanding slowly developing dynamic effects, such as wear-out, on SSC reliabilities may be instrumental in ensuring a safely and reliably operating nuclear fleet. Improving the estimation of a plant's continuously changing risk profile will allow for more meaningful risk insights, greater stakeholder confidence in risk insights, and increased operational flexibility.

  20. Dynamics of immune system vulnerabilities

    Science.gov (United States)

    Stromberg, Sean P.

    The adaptive immune system can be viewed as a complex system, which adapts, over time, to reflect the history of infections experienced by the organism. Understanding its operation requires viewing it in terms of tradeoffs under constraints and evolutionary history. It typically displays "robust, yet fragile" behavior, meaning common tasks are robust to small changes but novel threats or changes in environment can have dire consequences. In this dissertation we use mechanistic models to study several biological processes: the immune response, the homeostasis of cells in the lymphatic system, and the process that normally prevents autoreactive cells from entering the lymphatic system. Using these models we then study the effects of these processes interacting. We show that the mechanisms that regulate the numbers of cells in the immune system, in conjunction with the immune response, can act to suppress autoreactive cells from proliferating, thus showing quantitatively how pathogenic infections can suppress autoimmune disease. We also show that over long periods of time this same effect can thin the repertoire of cells that defend against novel threats, leading to an age correlated vulnerability. This vulnerability is shown to be a consequence of system dynamics, not due to degradation of immune system components with age. Finally, modeling a specific tolerance mechanism that normally prevents autoimmune disease, in conjunction with models of the immune response and homeostasis we look at the consequences of the immune system mistakenly incorporating pathogenic molecules into its tolerizing mechanisms. The signature of this dynamic matches closely that of the dengue virus system.

  1. Spin doctoring

    OpenAIRE

    Vozková, Markéta

    2011-01-01

    1 ABSTRACT The aim of this text is to provide an analysis of the phenomenon of spin doctoring in the Euro-Atlantic area. Spin doctors are educated people in the fields of semiotics, cultural studies, public relations, political communication and especially familiar with the infrastructure and the functioning of the media industry. Critical reflection of manipulative communication techniques puts spin phenomenon in historical perspective and traces its practical use in today's social communica...

  2. Use of multimedia messaging system (MMS) by junior doctors for scan image transmission in neurosurgery.

    Science.gov (United States)

    Ling, Ji Min; Lim, Kim Zhuan; Ng, Wai Hoe

    2012-02-01

    Multimedia Messaging Service (MMS) is used by neurosurgical residents to transmit scan images to the attending neurosurgeon in conjunction with telephone consultation. This service has been well received by the attending neurosurgeons, who felt that after viewing scan images on their phones, they felt increased confidence in clinical decision making and that it reduced the need for recall to the hospital. The use of MMS can be extended to junior doctors making referrals from regional hospitals with no neurosurgical cover. This study aims to validate the competency of non-neurosurgically trained junior doctors in selecting optimal images to transmit via MMS to the attending neurosurgeon on call. Ten junior doctors with no formal neurosurgical training and five neurosurgical residents were interviewed. They were shown the full complement of images together with relevant clinical history and assessment. They were then asked to make the radiological diagnosis and then select two images for MMS transmission to the attending neurosurgeon that they thought would best aid the neurosurgeon in clinical decision making. The attending neurosurgeon was asked to comment, on each image, whether his management plan would differ if he was shown the entire series of the images. All the images chosen are deemed appropriate, and the decision made based on the MMS images would be similar if the entire series of images were available to the neurosurgeon. However, 7 of 10 junior doctors were unable to read magnetic resonance images of lumbar spine. There was no significant difference in the images chosen by the neurosurgical residents and the junior doctors. It is feasible and safe for junior doctors to utilize MMS to transmit computed tomographic images to a neurosurgeon while making an urgent referral. The images selected are representative of the disease pathology and facilitate clinical decision making. Copyright © 2012 Elsevier Inc. All rights reserved.

  3. Simulation and sequential dynamical systems

    Energy Technology Data Exchange (ETDEWEB)

    Mortveit, H.S.; Reidys, C.M.

    1999-06-01

    Computer simulations have a generic structure. Motivated by this the authors present a new class of discrete dynamical systems that captures this structure in a mathematically precise way. This class of systems consists of (1) a loopfree graph {Upsilon} with vertex set {l_brace}1,2,{hor_ellipsis},n{r_brace} where each vertex has a binary state, (2) a vertex labeled set of functions (F{sub i,{Upsilon}}:F{sub 2}{sup n} {yields} F{sub 2}{sup n}){sub i} and (3) a permutation {pi} {element_of} S{sub n}. The function F{sub i,{Upsilon}} updates the state of vertex i as a function of the states of vertex i and its {Upsilon}-neighbors and leaves the states of all other vertices fixed. The permutation {pi} represents the update ordering, i.e., the order in which the functions F{sub i,{Upsilon}} are applied. By composing the functions F{sub i,{Upsilon}} in the order given by {pi} one obtains the dynamical system (equation given in paper), which the authors refer to as a sequential dynamical system, or SDS for short. The authors will present bounds for the number of functionally different systems and for the number of nonisomorphic digraphs {Gamma}[F{sub {Upsilon}},{pi}] that can be obtained by varying the update order and applications of these to specific graphs and graph classes.

  4. Issues and challenges in international doctoral education in nursing.

    Science.gov (United States)

    Ketefian, Shaké; Davidson, Patricia; Daly, John; Chang, Esther; Srisuphan, Wichit

    2005-09-01

    Education is a driving force in improving the health and welfare of communities globally. Doctoral education of nurses has been identified as a critical factor for provision of leadership in practice, scholarship, research, policy and education. Since the genesis of doctoral education in nursing in the USA in the 1930s, this movement has burgeoned to over 273 doctoral programs in over 30 countries globally. The present article seeks to identify the issues and challenges in nursing doctoral education globally, and those encountered by doctoral program graduates in meeting the challenges of contemporary health care systems. Information was derived from a comprehensive literature review. Electronic databases and the Internet, using the Google search engine, were searched using the key words "doctoral education"; "nursing"; "International Network for Doctoral Education in Nursing"; "global health"; "international research collaboration". Doctoral education has been a critical force in developing nurse leaders in education, management, policy and research domains. An absence of consensus in terminology and of accurate minimum data sets precludes comparison and debate across programs. The complexity and dynamism of contemporary globalized communities render significant challenges in the conduct of doctoral programs. Addressing funding issues and faculty shortages are key issues for doctoral programs, especially those in developing countries, to achieve an identity uniquely their own. These challenges can also afford considerable opportunities for discussion, debate and the formulation of innovative and collaborative solutions to advance nursing knowledge and scholarship. In spite of discrete differences between countries and regions, the similarities in the issues facing the development of doctoral programs internationally are more striking than the differences. The harnessing of a global collective to address these issues will likely serve to not only forge the future

  5. Synchronization of nonautonomous dynamical systems

    Directory of Open Access Journals (Sweden)

    Peter E. Kloeden

    2003-04-01

    Full Text Available The synchronization of two nonautonomous dynamical systems is considered, where the systems are described in terms of a skew-product formalism, i. e., in which an inputed autonomous driving system governs the evolution of the vector field of a differential equation with the passage of time. It is shown that the coupled trajectories converge to each other as time increases for sufficiently large coupling coefficient and also that the component sets of the pullback attractor of the coupled system converges upper semi continuously as the coupling parameter increases to the diagonal of the product of the corresponding component sets of the pullback attractor of a system generated by the average of the vector fields of the original uncoupled systems.

  6. Dynamical Systems and Motion Vision.

    Science.gov (United States)

    1988-04-01

    TASK Artificial Inteligence Laboratory AREA I WORK UNIT NUMBERS 545 Technology Square . Cambridge, MA 02139 C\\ II. CONTROLLING OFFICE NAME ANO0 ADDRESS...INSTITUTE OF TECHNOLOGY ARTIFICIAL INTELLIGENCE LABORATORY A.I.Memo No. 1037 April, 1988 Dynamical Systems and Motion Vision Joachim Heel Abstract: In this... Artificial Intelligence L3 Laboratory of the Massachusetts Institute of Technology. Support for the Laboratory’s [1 Artificial Intelligence Research is

  7. On Rank Driven Dynamical Systems

    Science.gov (United States)

    Veerman, J. J. P.; Prieto, F. J.

    2014-08-01

    We investigate a class of models related to the Bak-Sneppen (BS) model, initially proposed to study evolution. The BS model is extremely simple and yet captures some forms of "complex behavior" such as self-organized criticality that is often observed in physical and biological systems. In this model, random fitnesses in are associated to agents located at the vertices of a graph . Their fitnesses are ranked from worst (0) to best (1). At every time-step the agent with the worst fitness and some others with a priori given rank probabilities are replaced by new agents with random fitnesses. We consider two cases: The exogenous case where the new fitnesses are taken from an a priori fixed distribution, and the endogenous case where the new fitnesses are taken from the current distribution as it evolves. We approximate the dynamics by making a simplifying independence assumption. We use Order Statistics and Dynamical Systems to define a rank-driven dynamical system that approximates the evolution of the distribution of the fitnesses in these rank-driven models, as well as in the BS model. For this simplified model we can find the limiting marginal distribution as a function of the initial conditions. Agreement with experimental results of the BS model is excellent.

  8. Experimental Modeling of Dynamic Systems

    DEFF Research Database (Denmark)

    Knudsen, Morten Haack

    2006-01-01

    An engineering course, Simulation and Experimental Modeling, has been developed that is based on a method for direct estimation of physical parameters in dynamic systems. Compared with classical system identification, the method appears to be easier to understand, apply, and combine with physical...... insight. It is based on a sensitivity approach that is useful for choice of model structure, for experiment design, and for accuracy verification. The method is implemented in the Matlab toolkit Senstools. The method and the presentation have been developed with generally preferred learning styles in mind...

  9. An introduction to dynamical systems.

    Science.gov (United States)

    Sobie, Eric A

    2011-09-13

    This Teaching Resource provides lecture notes, slides, and a problem set that can assist in teaching concepts related to dynamical systems tools for the analysis of ordinary differential equation (ODE)-based models. The concepts are applied to familiar biological problems, and the material is appropriate for graduate students or advanced undergraduates. The lecture explains how equations describing biochemical signaling networks can be derived from diagrams that illustrate the reactions in graphical form. Because such reactions are most frequently described using systems of ODEs, the lecture discusses and illustrates the principles underlying the numerical solution of ODEs. Methods for determining the stability of steady-state solutions of one or two-dimensional ODE systems are covered and illustrated using standard graphical methods. The concept of a bifurcation, a condition at which a system's behavior changes qualitatively, is also introduced. A problem set is included that (i) requires students to implement an ODE model of biochemical reactions using MATLAB and (ii) allows them to explore dynamical systems concepts.

  10. Substitution dynamical systems spectral analysis

    CERN Document Server

    Queffélec, Martine

    2010-01-01

    This volume mainly deals with the dynamics of finitely valued sequences, and more specifically, of sequences generated by substitutions and automata. Those sequences demonstrate fairly simple combinatorical and arithmetical properties and naturally appear in various domains. As the title suggests, the aim of the initial version of this book was the spectral study of the associated dynamical systems: the first chapters consisted in a detailed introduction to the mathematical notions involved, and the description of the spectral invariants followed in the closing chapters. This approach, combined with new material added to the new edition, results in a nearly self-contained book on the subject. New tools - which have also proven helpful in other contexts - had to be developed for this study. Moreover, its findings can be concretely applied, the method providing an algorithm to exhibit the spectral measures and the spectral multiplicity, as is demonstrated in several examples. Beyond this advanced analysis, many...

  11. Dynamical System Approaches to Combinatorial Optimization

    DEFF Research Database (Denmark)

    Starke, Jens

    2013-01-01

    Several dynamical system approaches to combinatorial optimization problems are described and compared. These include dynamical systems derived from penalty methods; the approach of Hopfield and Tank; self-organizing maps, that is, Kohonen networks; coupled selection equations; and hybrid methods...

  12. Doctor patient communication-a vital yet neglected entity in Indian medical education system.

    Science.gov (United States)

    Agarwal, Akhilesh; Agarwal, Anshu; Nag, Kushal; Chakraborty, Saurav; Ali, Kamran

    2011-06-01

    Doctor patient communication is the most important and an integral part of any treatment regimen. Properly carried out it has been shown to have a therapeutic effect equivalent to drugs. Despite being so important part of treatment it is more than often taken and carried out casually. Apart from apathy towards this practice, its omission in the medical study curriculum is an important factor. This study was carried in amongst the surgical residents of surgical departments of various medical colleges to assess the attitude of surgical residents towards patient doctor communication. A questionnaire was forwarded by mail and email and the response was assessed: The responses of the surgical residents from various residents from different medical colleges were similar. Most of the residents prefer inclusion of communication skill in medical education curriculum.

  13. System dynamics in hydropower plants

    Energy Technology Data Exchange (ETDEWEB)

    Stuksrud, Dag Birger

    1998-12-31

    The main purpose of this thesis on system dynamics in hydropower plants was to establish new models of a hydropower system where the turbine/conduits and the electricity supply and generation are connected together as one unit such that possible interactions between the two power regimes can be studied. In order to describe the system dynamics as well as possible, a previously developed analytic model of high-head Francis turbines is improved. The model includes the acceleration resistance in the turbine runner and the draft tube. Expressions for the loss coefficients in the model are derived in order to obtain a purely analytic model. The necessity of taking the hydraulic inertia into account is shown by means of simulations. Unstable behaviour and a higher transient turbine speed than expected may occur for turbines with steep characteristics or large draft tubes. The turbine model was verified previously with respect to a high-head Francis turbine; the thesis performs an experimental verification on a low-head Francis turbine and compares the measurements with simulations from the improved turbine model. It is found that the dynamic turbine model is, after adjustment, capable of describing low-head machines as well with satisfying results. The thesis applies a method called the ``Limited zero-pole method`` to obtain new rational approximations of the elastic behaviour in the conduits with frictional damping included. These approximations are used to provide an accurate state space formulation of a hydropower plant. Simulations performed with the new computer programs show that hydraulic transients such as water-hammer and mass oscillations are reflected in the electric grid. Unstable governing performance in the electric and hydraulic parts also interact. This emphasizes the need for analysing the whole power system as a unit. 63 refs., 149 figs., 4 tabs.

  14. Power system dynamics and control

    CERN Document Server

    Kwatny, Harry G

    2016-01-01

    This monograph explores a consistent modeling and analytic framework that provides the tools for an improved understanding of the behavior and the building of efficient models of power systems. It covers the essential concepts for the study of static and dynamic network stability, reviews the structure and design of basic voltage and load-frequency regulators, and offers an introduction to power system optimal control with reliability constraints. A set of Mathematica tutorial notebooks providing detailed solutions of the examples worked-out in the text, as well as a package that will enable readers to work out their own examples and problems, supplements the text. A key premise of the book is that the design of successful control systems requires a deep understanding of the processes to be controlled; as such, the technical discussion begins with a concise review of the physical foundations of electricity and magnetism. This is followed by an overview of nonlinear circuits that include resistors, inductors, ...

  15. Classification of Dynamic Vehicle Routing Systems

    DEFF Research Database (Denmark)

    Larsen, Allan; Madsen, Oli B.G.; Solomon, Marius M.

    2007-01-01

    This chapter discusses important characteristics seen within dynamic vehicle routing problems. We discuss the differences between the traditional static vehicle routing problems and its dynamic counterparts. We give an in-depth introduction to the degree of dynamism measure which can be used...... to classify dynamic vehicle routing systems. Methods for evaluation of the performance of algorithms that solve on-line routing problems are discussed and we list some of the most important issues to include in the system objective. Finally, we provide a three-echelon classification of dynamic vehicle routing...... systems based on their degree of dynamism and the system objective....

  16. Doctor Down

    Directory of Open Access Journals (Sweden)

    N.V. Nagornaya

    2013-09-01

    Full Text Available The article presents the biographical data of John Langdon Down, his invaluable contribution to the development of rehabilitation programs for children with Down syndrome. The basis of these programs was the socialization of people with intellectual disabilities. In doctor Down’s rehabilitation center there were used methods, including health care, education, physical education, the formation of correct behavior.

  17. On some dynamical chameleon systems

    Science.gov (United States)

    Burkin, I. M.; Kuznetsova, O. I.

    2018-03-01

    It is now well known that dynamical systems can be categorized into systems with self-excited attractors and systems with hidden attractors. A self-excited attractor has a basin of attraction that is associated with an unstable equilibrium, while a hidden attractor has a basin of attraction that does not intersect with small neighborhoods of any equilibrium points. Hidden attractors play the important role in engineering applications because they allow unexpected and potentially disastrous responses to perturbations in a structure like a bridge or an airplane wing. In addition, complex behaviors of chaotic systems have been applied in various areas from image watermarking, audio encryption scheme, asymmetric color pathological image encryption, chaotic masking communication to random number generator. Recently, researchers have discovered the so-called “chameleon systems”. These systems were so named because they demonstrate self-excited or hidden oscillations depending on the value of parameters. The present paper offers a simple algorithm of synthesizing one-parameter chameleon systems. The authors trace the evolution of Lyapunov exponents and the Kaplan-Yorke dimension of such systems which occur when parameters change.

  18. Musashi dynamic image processing system

    International Nuclear Information System (INIS)

    Murata, Yutaka; Mochiki, Koh-ichi; Taguchi, Akira

    1992-01-01

    In order to produce transmitted neutron dynamic images using neutron radiography, a real time system called Musashi dynamic image processing system (MDIPS) was developed to collect, process, display and record image data. The block diagram of the MDIPS is shown. The system consists of a highly sensitive, high resolution TV camera driven by a custom-made scanner, a TV camera deflection controller for optimal scanning, which adjusts to the luminous intensity and the moving speed of an object, a real-time corrector to perform the real time correction of dark current, shading distortion and field intensity fluctuation, a real time filter for increasing the image signal to noise ratio, a video recording unit and a pseudocolor monitor to realize recording in commercially available products and monitoring by means of the CRTs in standard TV scanning, respectively. The TV camera and the TV camera deflection controller utilized for producing still images can be applied to this case. The block diagram of the real-time corrector is shown. Its performance is explained. Linear filters and ranked order filters were developed. (K.I.)

  19. System dynamics for mechanical engineers

    CERN Document Server

    Davies, Matthew

    2015-01-01

    This textbook is ideal for mechanical engineering students preparing to enter the workforce during a time of rapidly accelerating technology, where they will be challenged to join interdisciplinary teams. It explains system dynamics using analogies familiar to the mechanical engineer while introducing new content in an intuitive fashion. The fundamentals provided in this book prepare the mechanical engineer to adapt to continuous technological advances with topics outside traditional mechanical engineering curricula by preparing them to apply basic principles and established approaches to new problems. This book also: ·         Reinforces the connection between the subject matter and engineering reality ·         Includes an instructor pack with the online publication that describes in-class experiments with minimal preparation requirements ·         Provides content dedicated to the modeling of modern interdisciplinary technological subjects, including opto-mechanical systems, high...

  20. Dynamics of complex quantum systems

    CERN Document Server

    Akulin, Vladimir M

    2014-01-01

    This book gathers together a range of similar problems that can be encountered in different fields of modern quantum physics and that have common features with regard to multilevel quantum systems. The main motivation was to examine from a uniform standpoint various models and approaches that have been developed in atomic, molecular, condensed matter, chemical, laser and nuclear physics in various contexts. The book should help senior-level undergraduate, graduate students and researchers putting particular problems in these fields into a broader scientific context and thereby taking advantage of well-established techniques used in adjacent fields. This second edition has been expanded to include substantial new material (e.g. new sections on Dynamic Localization and on Euclidean Random Matrices and new chapters on Entanglement, Open Quantum Systems, and Coherence Protection). It is based on the author’s lectures at the Moscow Institute of Physics and Technology, at the CNRS Aimé Cotton Laboratory, and on ...

  1. KIDMAP, a web based system for gathering patients' feedback on their doctors

    Directory of Open Access Journals (Sweden)

    Lin Ching-Yih

    2009-06-01

    Full Text Available Abstract Background The gathering of feedback on doctors from patients after consultations is an important part of patient involvement and participation. This study first assesses the 23-item Patient Feedback Questionnaire (PFQ designed by the Picker Institute, Europe, to determine whether these items form a single latent trait. Then, an Internet module with visual representation is developed to gather patient views about their doctors; this program then distributes the individualized results by email. Methods A total of 450 patients were randomly recruited from a 1300-bed-size medical center in Taiwan. The Rasch rating scale model was used to examine the data-fit. Differential item functioning (DIF analysis was conducted to verify construct equivalence across the groups. An Internet module with visual representation was developed to provide doctors with the patient's online feedback. Results Twenty-one of the 23 items met the model's expectation, namely that they constitute a single construct. The test reliability was 0.94. DIF was found between ages and different kinds of disease, but not between genders and education levels. The visual approach of the KIDMAP module on the WWW seemed to be an effective approach to the assessment of patient feedback in a clinical setting. Conclusion The revised 21-item PFQ measures a single construct. Our work supports the hypothesis that the revised PFQ online version is both valid and reliable, and that the KIDMAP module is good at its designated task. Further research is needed to confirm data congruence for patients with chronic diseases.

  2. Description and outcomes of the DoctorQuality incident reporting system used at Baylor Medical Center at Grapevine.

    Science.gov (United States)

    Atherton, Traci

    2002-04-01

    To improve error reporting so as to increase patient safety in a health care environment in which many barriers to reporting exist. Baylor Medical Center at Grapevine, a 104-bed hospital in Northeast Tarrant County that is part of the Baylor Health Care System. Partnering with DoctorQuality to provide a consolidated, Web-based form for error reporting, online education, and a risk analyzer, complemented by efforts toward cultural change including staff training, encouragement of feedback, and the use of financial and non-financial incentives to report errors. After implementing the system, the number of events reported increased 250% to 500% costs for data collection, analysis, and management decreased by dollar 25,000 to dollar 35,000 annually; and the time required to track errors and make improvements was reduced 25% to 50%. Further, managers and staff were very satisfied with the system, ranking it >4 on a 5-point scale. The institution's partnership with DoctorQuality to create a single Web-based form for error reporting was successful in improving efficiency and ease of access in reporting. Further, the institution was successful in creating a new organizational culture around errors. The success was due in part to strong leadership, collaboration of multi-disciplinary staff, the ease of use of the system itself, and the effective educational, motivational, and communication mechanisms used.

  3. Topics in Extended Dynamical Systems

    Science.gov (United States)

    Bhagavatula, Ravi S.

    This thesis consists of three chapters. Each chapter is self-contained and is devoted to the investigation of a particular topic in extended dynamical systems. In the first chapter, an approach based on Langevin equations is implemented to understand the non-Gaussian nature of the probability distribution function (PDF) of local diffusive variables in extended dynamical systems, e.g., a passive scalar advected by turbulent velocity fluctuations. Two mechanisms are proposed for the origin of non-Gaussian tails: One relies on the nature of temporal correlations of the fluctuations that couple additively to the diffusive field, leading to exponential and stretched exponential tails in the PDF; the other depends on multiplicative coupling between the diffusive field and the fluctuations, producing algebraic tails in the PDF. The mechanisms are illustrated using models for a passive scalar and also a current driven Josephson junction array. This study indicates that shapes of local PDFs in turbulent states are non-universal and crucially depend on local couplings and time scales. The second chapter establishes the existence of a class of locally conserving chaotic (deterministic) systems that exhibit Generic Scale Invariance--algebraic decay of spatial and temporal correlations without tuning parameters. This study also reveals the similarity between noise and chaos in extended systems as far as long-wavelength and long -time behavior is concerned. Specifically, a two dimensional coupled-map lattice model with a conserved density is numerically shown to exhibit, in agreement with heuristic arguments, algebraic decay of spatio-temporal correlations in chaotic states with simple predictable exponents. The third chapter investigates scaling behavior of earthquakes in seismic zone models in which an earthquake is modeled by a quasi-static description that ignores short -time dynamics during an earthquake. The models incorporate the essential feature of long-ranged stress

  4. Doctoral Education

    DEFF Research Database (Denmark)

    Ridder, Hanne Mette Ochsner

    2015-01-01

    Doctoral education covers the “third cycle” of degrees following the bachelor’s and the master’s degree. The education of researchers is necessary for developing music therapy as a scientific discipline and calls for a certain research culture that not only brings knowledge on research, but invol......, multicultural identity and the ongoing and emerging needs of a discipline. The book is an unparalleled resource for academic advisors, prospective and current educators, clinical supervisors, clinicians and students of music therapy.......Doctoral education covers the “third cycle” of degrees following the bachelor’s and the master’s degree. The education of researchers is necessary for developing music therapy as a scientific discipline and calls for a certain research culture that not only brings knowledge on research...... with an integration of science and practice. This leads to a description of the principles of problem-based learning as a social constructive approach, problematization, self-directed learning and learning community. The chapter is concluded with an example of a model of doctoral education, the Aalborg model, where...

  5. Agency doctorates

    International Nuclear Information System (INIS)

    1970-01-01

    Staff members of the Agency working at the Seibersdorf laboratory are continuing to achieve high academic distinction. Two more - both Austrian - have now been awarded the degree of Doctor of Agriculture. Joachim Kramer, who is 26, graduated from the Hochschule fur Bodenkultur in 1967 with the degree of Diplom-Ingenieur and then started work in the plant breeding and genetics section of the laboratory under the direction of Dr. Knut Mikaelsen. The results of the research work he carried out were accepted as the subject of a thesis for which he has now been granted his doctorate. The doctoral promotion took place on 30 June, at a ceremony attended by Dr. Andre Finkelstein, Deputy Director General for Research and Isotopes. The subject of Dr. Kramer's thesis was a comprehensive study of the mutagenic effects of fast neutrons and gamma rays, and the influence of various modifying factors such as water content, oxygen and metabolic state of seeds at the time of irradiation. This work has contributed significantly to the understanding of the mechanisms by which these two types of ionizing radiation produce mutations in seeds. The knowledge gained will be of great importance in the efficient use of ionizing radiation in practical plant breeding. Paul Wassermann, who is 33 years old, joined the Agency in 1965. He, too, graduated from the Hochschule fur Bodenkultur as Diplom-Ingenieur in agriculture, having graduated with honours previously from the agricultural secondary school at Raumberg, Austria, in 1958. Dr. Wassermann's own words may be used to explain how he came to gain his doctorate. 'In October, 1966, I completed my studies at the Hochschule,' he writes. 'I was employed at the Agency laboratories in Seibersdorf, working in the plant and soils group. Encouraged by the interesting research which was performed there, a thesis entitled 'the Fate of Nitrogen in Submerged Rice Soils' was started, which finally led to the doctor's degree in Agriculture in June this year

  6. A System Dynamic Model of Leader Emergence

    Science.gov (United States)

    2008-03-01

    Judge, 2004; Judge, Bono, Ilies, & Gerhardt, 2002; Eagly, Johanneses-Schmidt, & Van Engen , 2003; Taggar, Hackett, & Saha, 1999; Stogdill, 1948...System dynamics emerged from the study of electrical control systems, and when generalized found many useful applications in natural systems outside...of the electrical world (Forrester, 1992). Whereas correlations describe cause and effect relationships in a linear equation, system dynamics

  7. Dynamical systems of algebraic origin

    CERN Document Server

    Schmidt, Klaus

    1995-01-01

    Although much of classical ergodic theory is concerned with single transformations and one-parameter flows, the subject inherits from statistical mechanics not only its name, but also an obligation to analyze spatially extended systems with multidimensional symmetry groups. However, the wealth of concrete and natural examples which has contributed so much to the appeal and development of classical dynamics, is noticeably absent in this more general theory. The purpose of this book is to help remedy this scarcity of explicit examples by introducing a class of continuous Zd-actions diverse enough to exhibit many of the new phenomena encountered in the transition from Z to Zd, but which nevertheless lends itself to systematic study: the Zd-actions by automorphisms of compact, abelian groups. One aspect of these actions, not surprising in itself but quite striking in its extent and depth nonetheless, is the connection with commutative algebra and arithmetical algebraic geometry. The algebraic framework resulting...

  8. Biofluid Dynamics in Cardiovascular System

    Science.gov (United States)

    Chung, Hansol; Yoo, Su Jung; Kyung, Richard

    2011-11-01

    Biofluid dynamics is characterized by the study of fluids in biological systems. Common biofluid systems include blood flow in the cardiovascular system and airflow in the lungs. The mathematical modeling of blood flow through the complex geometry of a prosthetic heart valve is a difficult task. In such a problem the complex geometries of the valve must be modeled properly so that they can be studied numerically. The present analysis is performed on a disk-type prosthetic heart valve. The valve is assumed to be in the aortic position and observed the structure of the valve cage influence the flow field near an aortic valve. For the purpose of mathematical modeling, the laminar incompressible two-dimensional steady flow of a homogeneous Newtonian fluid with constant viscosity is assumed. The flow is considered during the greater part of systole when the valve is fully open. Convergent numerical solutions are obtained for Reynolds numbers of 30, 180, 900 and 4500. Stream function, horizontal velocity, vertical velocity and shear stress solutions are computed at every grid point.

  9. Dynamical Signatures of Living Systems

    Science.gov (United States)

    Zak, M.

    1999-01-01

    One of the main challenges in modeling living systems is to distinguish a random walk of physical origin (for instance, Brownian motions) from those of biological origin and that will constitute the starting point of the proposed approach. As conjectured, the biological random walk must be nonlinear. Indeed, any stochastic Markov process can be described by linear Fokker-Planck equation (or its discretized version), only that type of process has been observed in the inanimate world. However, all such processes always converge to a stable (ergodic or periodic) state, i.e., to the states of a lower complexity and high entropy. At the same time, the evolution of living systems directed toward a higher level of complexity if complexity is associated with a number of structural variations. The simplest way to mimic such a tendency is to incorporate a nonlinearity into the random walk; then the probability evolution will attain the features of diffusion equation: the formation and dissipation of shock waves initiated by small shallow wave disturbances. As a result, the evolution never "dies:" it produces new different configurations which are accompanied by an increase or decrease of entropy (the decrease takes place during formation of shock waves, the increase-during their dissipation). In other words, the evolution can be directed "against the second law of thermodynamics" by forming patterns outside of equilibrium in the probability space. Due to that, a specie is not locked up in a certain pattern of behavior: it still can perform a variety of motions, and only the statistics of these motions is constrained by this pattern. It should be emphasized that such a "twist" is based upon the concept of reflection, i.e., the existence of the self-image (adopted from psychology). The model consists of a generator of stochastic processes which represents the motor dynamics in the form of nonlinear random walks, and a simulator of the nonlinear version of the diffusion

  10. Revisiting current "barefoot doctors" in border areas of China: system of services, financial issue and clinical practice prior to introducing integrated management of childhood illness (IMCI).

    Science.gov (United States)

    Li, Xiuyun; Chongsuvivatwong, Virasakdi; Xia, Xiaoling; Sangsupawanich, Pasuree; Zheng, Wenjing; Ma, Keling

    2012-08-07

    Under-5-years child mortality remains high in rural China. Integrated management of childhood illness (IMCI) was introduced to China in 1998, but only a few rural areas have been included. This study aimed at assessing the current situation of the health system of rural health care and evaluating the clinical competency of village doctors in management of childhood illnesses prior to implementing IMCI programme in remote border rural areas. The study was carried out in the border areas of Puer prefecture of Yunnan province. There were 182 village doctors in the list of the health bureau in these border areas. Of these, 154 (84.6%) were recruited into the study. The local health system components were investigated using a qualitative approach and analyzed with triangulation of information from different sources. The clinical component was assessed objectively and quantitatively presented using descriptive statistics. The study found that the New Rural Cooperative Medical Scheme (NRCMS) coordinated the health insurance system and the provider service through 3 tiers: village doctor, township and county hospitals. The 30 RMB per person per year premium did not cover the referral cost, and thereby decreased the number of referrals. In contrast to available treatment facilities and drug supply, the level of basic medical education of village doctors and township doctors was low. Discontent among village doctors was common, especially concerning low rates of return from the service, exceptions being procedures such as injections, which in fact may create moral hazards to the patients. Direct observation on the assessment and management of paediatric patients by village doctors revealed inadequate history taking and physical examination, inability to detect potentially serious complications, overprescription of injection and antibiotics, and underprescription of oral rehydration salts and poor quality of counseling. There is a need to improve health finance and clinical

  11. Hybrid nonnegative and computational dynamical systems

    Directory of Open Access Journals (Sweden)

    Wassim M. Haddad

    2002-01-01

    Full Text Available Nonnegative and Compartmental dynamical systems are governed by conservation laws and are comprised of homogeneous compartments which exchange variable nonnegative quantities of material via intercompartmental flow laws. These systems typically possess hierarchical (and possibly hybrid structures and are remarkably effective in capturing the phenomenological features of many biological and physiological dynamical systems. In this paper we develop several results on stability and dissipativity of hybrid nonnegative and Compartmental dynamical systems. Specifically, using linear Lyapunov functions we develop sufficient conditions for Lyapunov and asymptotic stability for hybrid nonnegative dynamical systems. In addition, using linear and nonlinear storage functions with linear hybrid supply rates we develop new notions of dissipativity theory for hybrid nonnegative dynamical systems. Finally, these results are used to develop general stability criteria for feedback interconnections of hybrid nonnegative dynamical systems.

  12. Building doctoral ecologies

    DEFF Research Database (Denmark)

    Bengtsen, Søren Smedegaard

    2018-01-01

    heavily from the support from informal and extra-curricular researcher communities and non-formal support systems even beyond the institution in the private and societal lifeworlds. The chapter describes and analyses such forms of organizational and existential darkness within doctoral education......During the recent years doctoral education has ultimately left its seclusion within the disciplines and become part of national and global policy agendas, claimed to ensure societal welfare and financial growth. As a consequence more resources have been allocated to the formalization...

  13. Robust dissipativity for uncertain impulsive dynamical systems

    Directory of Open Access Journals (Sweden)

    Liu Bin

    2003-01-01

    Full Text Available We discuss the robust dissipativity with respect to the quadratic supply rate for uncertain impulsive dynamical systems. By employing the Hamilton-Jacobi inequality approach, some sufficient conditions of robust dissipativity for this kind of system are established. Finally, we specialize the obtained results to the case of uncertain linear impulsive dynamical systems.

  14. An Axiomatic Representation of System Dynamics

    CERN Document Server

    Baianu, I

    2004-01-01

    An axiomatic representation of system dynamics is introduced in terms of categories, functors, organismal supercategories, limits and colimits of diagrams. Specific examples are considered in Complex Systems Biology, such as ribosome biogenesis and Hormonal Control in human subjects. "Fuzzy" Relational Structures are also proposed for flexible representations of biological system dynamics and organization.

  15. [A comparative study on Koii (public doctor) system and its effect on public health in colonial Taiwan and Korea].

    Science.gov (United States)

    Moon, Myungki

    2014-08-01

    Koii(Public Doctor) System introduced into Taiwan in 1896 for the purpose of filling up medical vacuum of rural area and therefore spreading modern medical system all over Taiwan, was transplanted in 1913 into Colonial Korea for the same purpose. In terms of system itself Koii system in both areas were almost the same, but quite different in practices. First, Koiis in Taiwan was forced to write concrete medical report every month on the medical situation in the area under jurisdiction, whereas to those in Korea writing monthly report was not so compulsory. This difference resulted in some gaps in the quality of medical statistics of the two areas. Second, Unlike their counterparts in Korea, Koiis in Taiwan organized their own associations both locally and nationally and it helped to build up their own networks and share informations on medical situation including informations on infectious diseases. Third, Koiis in Taiwan formed more harmonious relationship between Taiwanese Police than their counterparts in Korea, which helped them to execute various medical activities in more comfortable environment. Taiwanese People went to medical institutions a lot more frequently than Korean People, and this difference was basically derived from the quite different density of Koii assignment in both areas. Korean People had to spend more time and money to utilize modern medical institutions than Taiwanese People did. The different density of Koii assignment also affected the results of prevention and eradication of infectious diseases; in Taiwan plague and small-pox has been successfully controled, whereas Chosun Government general was not so successful in controling infectious diseases including small-pox. Small-pox infected in Korea was about 6 times to Taiwan, and the number of death by small-pox was 9 times to Taiwan. One of the keys to this difference is the different role of Koiis. In Korea, Koiis could do little thing about infectious diseases mainly because of

  16. Hybrid Dynamical Systems Modeling, Stability, and Robustness

    CERN Document Server

    Goebel, Rafal; Teel, Andrew R

    2012-01-01

    Hybrid dynamical systems exhibit continuous and instantaneous changes, having features of continuous-time and discrete-time dynamical systems. Filled with a wealth of examples to illustrate concepts, this book presents a complete theory of robust asymptotic stability for hybrid dynamical systems that is applicable to the design of hybrid control algorithms--algorithms that feature logic, timers, or combinations of digital and analog components. With the tools of modern mathematical analysis, Hybrid Dynamical Systems unifies and generalizes earlier developments in continuous-time and discret

  17. Inequality and Doctoral Education: Exploring the "Rules" of Doctoral Study through Bourdieu's Notion of Field

    Science.gov (United States)

    Gopaul, Bryan

    2015-01-01

    While studies have examined a myriad of issues in doctoral study, much of this research has not employed the tools of major social and cultural thinkers to the dynamics of doctoral education. This paper explores the use of Bourdieu's notion of field to render visible the practices and contexts of doctoral education that produce inequalities across…

  18. Educational program in Japan for Dementia Support Doctors who support medical and care systems as liaisons for demented older adults in the community.

    Science.gov (United States)

    Washimi, Yukihiko; Horibe, Kentaro; Takeda, Akinori; Abe, Takashi; Toba, Kenji

    2014-04-01

    Now that the number of elderly people has increased and the number of dementia patients is rapidly increasing, dementia might be regarded as a common disease. Under these circumstances, the establishment of systems to support the elderly with dementia from the early stages, and to provide primary care doctors and care workers with necessary education is an urgent issue. Up to the end of 2012, a total of 2680 doctors had been certified as Dementia Support Doctors (DSD). The DSD's function and roles are: (i) to support primary care doctors and care specialists involved in the medical care, and general care of dementia patients; (ii) to facilitate multidisciplinary cooperation led by a Community General Support Center; and (iii) to give lectures about dementia to primary care doctors and educate people in the community. DSD are more skilled than primary care doctors in the following functions: differential diagnosis; outpatient services to deal with behavioral and psychological symptoms of dementia; community liaison; and home care. © 2014 Japan Geriatrics Society.

  19. Attachment is a dynamic system

    Directory of Open Access Journals (Sweden)

    Zlatka Cugmas

    2003-04-01

    Full Text Available On the basis of the study of recent scientific literature about the development of attachment, the author answers the following questions: which are the postulates the theory of attachment has about the stability of the patterns of attachment, which level of stability in the patterns of attachment from infancy to adulthood these studies illuminate and which factors significantly influence the (instability of the patterns of attachment in time. The theory of attachment assumes that normal circumstances elicit stability. Changes, however, can be the result of important events influencing the sensitivity of the object of attachment. Agreement has not yet been reached regarding the percentage of stability in the patterns of attachment. There is more agreement regarding attachment in adulthood than that in childhood. The results depend on the size and characteristics of the subjects of the research, the measuring instruments, type of data analysis etc. The author concludes that attachment is a dynamic system influenced by significant changes in life (the cognitive development of the child, external care, parents' divorce, different stressful situations. As the influence of stressful events on the individual person' s quality of attachment is examined, it is necessary to consider also his/her temperamental characteristics, role of other people in their lives, etc.

  20. Dissipative control for singular impulsive dynamical systems

    Directory of Open Access Journals (Sweden)

    Li Yang

    2012-04-01

    Full Text Available The aim of this work is to study the dissipative control problem for singular impulsive dynamical systems. We start by introducing the impulse to the singular systems, and give the definition of the dissipation for singular impulsive dynamical systems. Then we discuss the dissipation of singular impulsive dynamical systems, we obtain some sufficient and necessary conditions for dissipation of these systems by solving some linear matrix inequalities (LMIs. By using this method, we design a state feedback controller to make the closed-loop system dissipative. At last, we testify the feasibility of the method by a numerical example.

  1. Dynamical systems generated by linear maps

    CERN Document Server

    Dolićanin, Ćemal B

    2014-01-01

    The book deals with dynamical systems, generated by linear mappings of finite dimensional spaces and their applications. These systems have a relatively simple structure from the point of view of the modern dynamical systems theory. However, for the dynamical systems of this sort, it is possible to obtain explicit answers to specific questions being useful in applications. The considered problems are natural and look rather simple, but in reality in the course of investigation, they confront users with plenty of subtle questions, and their detailed analysis needs a substantial effort. The problems arising are related to linear algebra and dynamical systems theory, and therefore, the book can be considered as a natural amplification, refinement and supplement to linear algebra and dynamical systems theory textbooks.

  2. Multibody system dynamics, robotics and control

    CERN Document Server

    Gerstmayr, Johannes

    2013-01-01

    The volume contains 19 contributions by international experts in the field of multibody system dynamics, robotics and control. The book aims to bridge the gap between the modeling of mechanical systems by means of multibody dynamics formulations and robotics. In the classical approach, a multibody dynamics model contains a very high level of detail, however, the application of such models to robotics or control is usually limited. The papers aim to connect the different scientific communities in multibody dynamics, robotics and control. Main topics are flexible multibody systems, humanoid robots, elastic robots, nonlinear control, optimal path planning, and identification.

  3. Nonautonomous dynamical systems in the life sciences

    CERN Document Server

    Pötzsche, Christian

    2013-01-01

    Nonautonomous dynamics describes the qualitative behavior of evolutionary differential and difference equations, whose right-hand side is explicitly time dependent. Over recent years, the theory of such systems has developed into a highly active field related to, yet recognizably distinct from that of classical autonomous dynamical systems. This development was motivated by problems of applied mathematics, in particular in the life sciences where genuinely nonautonomous systems abound. The purpose of this monograph is to indicate through selected, representative examples how often nonautonomous systems occur in the life sciences and to outline the new concepts and tools from the theory of nonautonomous dynamical systems that are now available for their investigation.

  4. Dynamical entropy for infinite quantum systems

    International Nuclear Information System (INIS)

    Hudetz, T.

    1990-01-01

    We review the recent physical application of the so-called Connes-Narnhofer-Thirring entropy, which is the successful quantum mechanical generalization of the classical Kolmogorov-Sinai entropy and, by its very conception, is a dynamical entropy for infinite quantum systems. We thus comparingly review also the physical applications of the classical dynamical entropy for infinite classical systems. 41 refs. (Author)

  5. Narcissistic group dynamics of multiparty systems

    NARCIS (Netherlands)

    Schruijer, S.G.L.

    2015-01-01

    Purpose – This paper aims to introduce and illustrate the notion of narcissistic group dynamics. It is claimed that narcissism does not simply reside within individuals but can be characteristic of groups and social systems. In this case, the focus is on narcissistic dynamics in multiparty systems.

  6. Trust dynamics in a large system implementation

    DEFF Research Database (Denmark)

    Schlichter, Bjarne Rerup; Rose, Jeremy

    2013-01-01

    outcomes, but largely ignored the dynamics of trust relations. Giddens, as part of his study of modernity, theorises trust dynamics in relation to abstract social systems, though without focusing on information systems. We use Giddens’ concepts to investigate evolving trust relationships in a longitudinal...

  7. Trust Dynamics in a Large System Implementation

    DEFF Research Database (Denmark)

    Schlichter, Bjarne Rerup; Rose, Jeremy

    2013-01-01

    the dynamics of trust relations. Giddens, as part of his study of modernity, theorises trust dynamics in relation to abstract social systems, though without focusing on information systems. We use Gid-dens’ concepts to investigate evolving trust relationships in a longitudinal case analysis of a large...

  8. Logical entropy of quantum dynamical systems

    Directory of Open Access Journals (Sweden)

    Ebrahimzadeh Abolfazl

    2016-01-01

    Full Text Available This paper introduces the concepts of logical entropy and conditional logical entropy of hnite partitions on a quantum logic. Some of their ergodic properties are presented. Also logical entropy of a quantum dynamical system is dehned and ergodic properties of dynamical systems on a quantum logic are investigated. Finally, the version of Kolmogorov-Sinai theorem is proved.

  9. The dynamical systems approach to numerical integration

    Science.gov (United States)

    Wisdom, Jack

    2018-03-01

    The dynamical systems approach to numerical integration is reviewed and extended. The new method is compared to some alternative methods based on the Lie series approach. The test problem is the motion of the outer planets. The algorithms developed using the dynamical systems approach perform well.

  10. System dynamics modelling of situation awareness

    CSIR Research Space (South Africa)

    Oosthuizen, R

    2015-11-01

    Full Text Available . The feedback loops and delays in the Command and Control system also contribute to the complex dynamic behavior. This paper will build on existing situation awareness models to develop a System Dynamics model to support a qualitative investigation through...

  11. Partial dynamical systems, fell bundles and applications

    CERN Document Server

    Exel, Ruy

    2017-01-01

    Partial dynamical systems, originally developed as a tool to study algebras of operators in Hilbert spaces, has recently become an important branch of algebra. Its most powerful results allow for understanding structural properties of algebras, both in the purely algebraic and in the C*-contexts, in terms of the dynamical properties of certain systems which are often hiding behind algebraic structures. The first indication that the study of an algebra using partial dynamical systems may be helpful is the presence of a grading. While the usual theory of graded algebras often requires gradings to be saturated, the theory of partial dynamical systems is especially well suited to treat nonsaturated graded algebras which are in fact the source of the notion of "partiality". One of the main results of the book states that every graded algebra satisfying suitable conditions may be reconstructed from a partial dynamical system via a process called the partial crossed product. Running in parallel with partial dynamica...

  12. Dynamical systems on 2- and 3-manifolds

    CERN Document Server

    Grines, Viacheslav Z; Pochinka, Olga V

    2016-01-01

    This book provides an introduction to the topological classification of smooth structurally stable diffeomorphisms on closed orientable 2- and 3-manifolds.The topological classification is one of the main problems of the theory of dynamical systems and the results presented in this book are mostly for dynamical systems satisfying Smale's Axiom A. The main results on the topological classification of discrete dynamical systems are widely scattered among many papers and surveys. This book presents these results fluidly, systematically, and for the first time in one publication. Additionally, this book discusses the recent results on the topological classification of Axiom A diffeomorphisms focusing on the nontrivial effects of the dynamical systems on 2- and 3-manifolds. The classical methods and approaches which are considered to be promising for the further research are also discussed. < The reader needs to be familiar with the basic concepts of the qualitative theory of dynamical systems which are present...

  13. Dynamics of vehicle-road coupled system

    CERN Document Server

    Yang, Shaopu; Li, Shaohua

    2015-01-01

    Vehicle dynamics and road dynamics are usually considered to be two largely independent subjects. In vehicle dynamics, road surface roughness is generally regarded as random excitation of the vehicle, while in road dynamics, the vehicle is generally regarded as a moving load acting on the pavement. This book suggests a new research concept to integrate the vehicle and the road system with the help of a tire model, and establishes a cross-subject research framework dubbed vehicle-pavement coupled system dynamics. In this context, the dynamics of the vehicle, road and the vehicle-road coupled system are investigated by means of theoretical analysis, numerical simulations and field tests. This book will be a valuable resource for university professors, graduate students and engineers majoring in automotive design, mechanical engineering, highway engineering and other related areas. Shaopu Yang is a professor and deputy president of Shijiazhuang Tiedao University, China; Liqun Chen is a professor at Shanghai Univ...

  14. Transcribing the balanced scorecard into system dynamics

    DEFF Research Database (Denmark)

    Nielsen, Steen; Nielsen, Erland Hejn

    2013-01-01

    The purpose of this paper is to show how a System Dynamics Modelling approach can be integrated into the Balanced Scorecard (BSC) for a case company with special focus on the handling of causality in a dynamic perspective. The BSC model includes five perspectives and a number of financial and non-financial...... the cause-and-effect relationships of an integrated BSC model. Including dynamic aspects of BSCs into the discussion is only in its infancy, so the aim of our work is also to contribute to both scholars’ and practitioners’ general understanding of how such delayed dynamic effects propagate through system...

  15. Interdisciplinary research and education in the Vienna Doctoral Programme on Water Resource Systems: a framework for evaluation

    Science.gov (United States)

    Bloeschl, G.; Carr, G.; Loucks, D. P.

    2017-12-01

    Greater understanding of how interdisciplinary research and education evolves is critical for identifying and implementing appropriate programme management strategies. We propose a program evaluation framework that is based on social learning processes (individual learning, interdisciplinary research practices, and interaction between researchers with different backgrounds); social capital outcomes (ability to interact, interpersonal connectivity, and shared understanding); and knowledge and human capital outcomes (new knowledge that integrates multiple research fields). The framework is tested on established case study doctoral program: the Vienna Doctoral Program on Water Resource Systems. Data are collected via mixed qualitative/quantitative methods that include semi-structured interviews, publication co-author analysis, analysis of research proposals, categorisation of the interdisciplinarity of publications and graduate analysis. Through the evaluation and analysis, several interesting findings about how interdisciplinary research evolves and can be supported are identified. Firstly, different aspects of individual learning seem to contribute to a researcher's ability to interact with researchers from other research fields and work collaboratively. These include learning new material from different research fields, learning how to learn new material and learning how to integrate different material. Secondly, shared interdisciplinary research practices can be identified that may be common to other programs and support interaction and shared understanding between different researchers. They include clarification and questioning, harnessing differences and setting defensible research boundaries. Thirdly, intensive interaction between researchers from different backgrounds support connectivity between the researchers, further enabling cross-disciplinary collaborative work. The case study data suggest that social learning processes and social capital outcomes

  16. Information Processing Capacity of Dynamical Systems

    Science.gov (United States)

    Dambre, Joni; Verstraeten, David; Schrauwen, Benjamin; Massar, Serge

    2012-07-01

    Many dynamical systems, both natural and artificial, are stimulated by time dependent external signals, somehow processing the information contained therein. We demonstrate how to quantify the different modes in which information can be processed by such systems and combine them to define the computational capacity of a dynamical system. This is bounded by the number of linearly independent state variables of the dynamical system, equaling it if the system obeys the fading memory condition. It can be interpreted as the total number of linearly independent functions of its stimuli the system can compute. Our theory combines concepts from machine learning (reservoir computing), system modeling, stochastic processes, and functional analysis. We illustrate our theory by numerical simulations for the logistic map, a recurrent neural network, and a two-dimensional reaction diffusion system, uncovering universal trade-offs between the non-linearity of the computation and the system's short-term memory.

  17. Stochastic Thermodynamics: A Dynamical Systems Approach

    Directory of Open Access Journals (Sweden)

    Tanmay Rajpurohit

    2017-12-01

    Full Text Available In this paper, we develop an energy-based, large-scale dynamical system model driven by Markov diffusion processes to present a unified framework for statistical thermodynamics predicated on a stochastic dynamical systems formalism. Specifically, using a stochastic state space formulation, we develop a nonlinear stochastic compartmental dynamical system model characterized by energy conservation laws that is consistent with statistical thermodynamic principles. In particular, we show that the difference between the average supplied system energy and the average stored system energy for our stochastic thermodynamic model is a martingale with respect to the system filtration. In addition, we show that the average stored system energy is equal to the mean energy that can be extracted from the system and the mean energy that can be delivered to the system in order to transfer it from a zero energy level to an arbitrary nonempty subset in the state space over a finite stopping time.

  18. Information Processing Capacity of Dynamical Systems

    Science.gov (United States)

    Dambre, Joni; Verstraeten, David; Schrauwen, Benjamin; Massar, Serge

    2012-01-01

    Many dynamical systems, both natural and artificial, are stimulated by time dependent external signals, somehow processing the information contained therein. We demonstrate how to quantify the different modes in which information can be processed by such systems and combine them to define the computational capacity of a dynamical system. This is bounded by the number of linearly independent state variables of the dynamical system, equaling it if the system obeys the fading memory condition. It can be interpreted as the total number of linearly independent functions of its stimuli the system can compute. Our theory combines concepts from machine learning (reservoir computing), system modeling, stochastic processes, and functional analysis. We illustrate our theory by numerical simulations for the logistic map, a recurrent neural network, and a two-dimensional reaction diffusion system, uncovering universal trade-offs between the non-linearity of the computation and the system's short-term memory. PMID:22816038

  19. Talking to Your Doctor

    Medline Plus

    Full Text Available ... communication. Remember that nurses and pharmacists are also good sources of information. How to Talk to your Doctor Talking With Your Doctor , NIH News in Health Español Talking to Your Doctor , National Eye Institute ( ...

  20. Session 6: Dynamic Modeling and Systems Analysis

    Science.gov (United States)

    Csank, Jeffrey; Chapman, Jeffryes; May, Ryan

    2013-01-01

    These presentations cover some of the ongoing work in dynamic modeling and dynamic systems analysis. The first presentation discusses dynamic systems analysis and how to integrate dynamic performance information into the systems analysis. The ability to evaluate the dynamic performance of an engine design may allow tradeoffs between the dynamic performance and operability of a design resulting in a more efficient engine design. The second presentation discusses the Toolbox for Modeling and Analysis of Thermodynamic Systems (T-MATS). T-MATS is a Simulation system with a library containing the basic building blocks that can be used to create dynamic Thermodynamic Systems. Some of the key features include Turbo machinery components, such as turbines, compressors, etc., and basic control system blocks. T-MAT is written in the Matlab-Simulink environment and is open source software. The third presentation focuses on getting additional performance from the engine by allowing the limit regulators only to be active when a limit is danger of being violated. Typical aircraft engine control architecture is based on MINMAX scheme, which is designed to keep engine operating within prescribed mechanical/operational safety limits. Using a conditionally active min-max limit regulator scheme, additional performance can be gained by disabling non-relevant limit regulators

  1. A matter of degrees: the introduction of clinical doctorates to the Saudi higher education system and a comparative prospective from the American model.

    Science.gov (United States)

    Sayed, M Gary; Al-Shehri, Mohammad Y

    2012-01-01

    Recent unprecedented growth in Saudi population challenged its infrastructure and intensified demand for higher education and healthcare. In response, both the government and the private sector founded numerous colleges and universities, increasing the overall number from 8 to 49 institutions of higher education. A significant portion of the expansion has been in the health professions higher education, which also included the establishment of new teaching hospitals and other medical training facilities. As part of this growth, practice (clinical) doctorates have conspicuously made their presence felt in Saudi Arabia. The doctor of pharmacy is the first clinical doctorate that has been formally adopted as the terminal professional degree in the field. Others are in the works. Results are presented using descriptive methods. Data were collected from reviews of the literature and individual institutional websites of Saudi colleges, universities and salient governmental regulatory and national accrediting agencies. This article will introduce clinical doctorates, their status and state of implementation in the American health professions higher education system as a possible model. The article will review the current status of clinical doctorates' implementation in Saudi Arabia. It will conclude with a recommendation for concerned stake holders, including policy makers, educators, and practitioners.

  2. Fault diagnosis for dynamic power system

    International Nuclear Information System (INIS)

    Thabet, A.; Abdelkrim, M.N.; Boutayeb, M.; Didier, G.; Chniba, S.

    2011-01-01

    The fault diagnosis problem for dynamic power systems is treated, the nonlinear dynamic model based on a differential algebraic equations is transformed with reduced index to a simple dynamic model. Two nonlinear observers are used for generating the fault signals for comparison purposes, one of them being an extended Kalman estimator and the other a new extended kalman filter with moving horizon with a study of convergence based on the choice of matrix of covariance of the noises of system and measurements. The paper illustrates a simulation study applied on IEEE 3 buses test system.

  3. SIAM conference on applications of dynamical systems

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    A conference (Oct.15--19, 1992, Snowbird, Utah; sponsored by SIAM (Society for Industrial and Applied Mathematics) Activity Group on Dynamical Systems) was held that highlighted recent developments in applied dynamical systems. The main lectures and minisymposia covered theory about chaotic motion, applications in high energy physics and heart fibrillations, turbulent motion, Henon map and attractor, integrable problems in classical physics, pattern formation in chemical reactions, etc. The conference fostered an exchange between mathematicians working on theoretical issues of modern dynamical systems and applied scientists. This two-part document contains abstracts, conference program, and an author index.

  4. Collective Dynamics of Nonlinear and Disordered Systems

    CERN Document Server

    Radons, G; Just, W

    2005-01-01

    Phase transitions in disordered systems and related dynamical phenomena are a topic of intrinsically high interest in theoretical and experimental physics. This book presents a unified view, adopting concepts from each of the disjoint fields of disordered systems and nonlinear dynamics. Special attention is paid to the glass transition, from both experimental and theoretical viewpoints, to modern concepts of pattern formation, and to the application of the concepts of dynamical systems for understanding equilibrium and nonequilibrium properties of fluids and solids. The content is accessible to graduate students, but will also be of benefit to specialists, since the presentation extends as far as the topics of ongoing research work.

  5. Dynamics of mechanical systems with variable mass

    CERN Document Server

    Belyaev, Alexander

    2014-01-01

    The book presents up-to-date and unifying formulations for treating dynamics of different types of mechanical systems with variable mass. The starting point is overview of the continuum mechanics relations of balance and jump for open systems from which extended Lagrange and Hamiltonian formulations are derived. Corresponding approaches are stated at the level of analytical mechanics with emphasis on systems with a position-dependent mass and at the level of structural mechanics. Special emphasis is laid upon axially moving structures like belts and chains, and on pipes with an axial flow of fluid. Constitutive relations in the dynamics of systems with variable mass are studied with particular reference to modeling of multi-component mixtures. The dynamics of machines with a variable mass are treated in detail and conservation laws and the stability of motion will be analyzed. Novel finite element formulations for open systems in coupled fluid and structural dynamics are presented.

  6. Constraint Embedding for Multibody System Dynamics

    Science.gov (United States)

    Jain, Abhinandan

    2009-01-01

    This paper describes a constraint embedding approach for the handling of local closure constraints in multibody system dynamics. The approach uses spatial operator techniques to eliminate local-loop constraints from the system and effectively convert the system into tree-topology systems. This approach allows the direct derivation of recursive O(N) techniques for solving the system dynamics and avoiding the expensive steps that would otherwise be required for handling the closedchain dynamics. The approach is very effective for systems where the constraints are confined to small-subgraphs within the system topology. The paper provides background on the spatial operator O(N) algorithms, the extensions for handling embedded constraints, and concludes with some examples of such constraints.

  7. Understanding and Modeling Teams As Dynamical Systems

    Directory of Open Access Journals (Sweden)

    Jamie C. Gorman

    2017-07-01

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

  8. Quantum dynamics of dynamically unstable, integrable few-mode systems

    Science.gov (United States)

    Mathew, Ranchu; Tiesinga, Eite

    2017-04-01

    Recently, quenches in isolated ultra-cold atomic quantum systems have become a subject of intense study. We consider quantum few-mode systems that are integrable in their classical mean-field limit and become dynamically unstable after a quench of a system parameter. Specifically, we study the cases of a Bose-Einstein condensate (BEC) in a double-well potential and of an antiferromagnetic F = 1 spinor BEC constrained to a single spatial mode. First, we study the time dynamics of a coherent state after the quench within the truncated Wigner approximation and find that due to phase-space mixing the systems relax to a steady state. Using action-angle formalism and guided by insights from the related pendulum system, we obtain analytical expressions for the time evolution of expectation values of observables and their long-time values. We also study the full quantum dynamics of the systems. Comparing their results with the TWA results, we find agreement in the long-time expectation value of the observables. The relaxation time scales, however, are different.

  9. Solved problems in dynamical systems and control

    CERN Document Server

    Tenreiro-Machado, J; Valério, Duarte; Galhano, Alexandra M

    2016-01-01

    This book presents a collection of exercises on dynamical systems, modelling and control. Each topic covered includes a summary of the theoretical background, problems with solutions, and further exercises.

  10. FDA Adverse Event Reporting System: Recruiting Doctors to Make Surveillance a Little Less Passive.

    Science.gov (United States)

    Mann, Justin M

    2015-01-01

    Within the last few decades, a shift has taken place in FDA's approach to drug development, with greater emphasis put on postmarketing data collection and less on the traditional premarketing scheme. The FDA Adverse Event Reporting System (FAERS) is the primary system for collecting Adverse Events, but has been criticized for years for the low reporting rate into the system and the poor quality of the information submitted. This paper argues that physicians need to be required to submit adverse event reports to FAERS, because such a requirement (1) would produce a greater number of the high quality reports necessary to better determine causality; (2) is merely an extension of physicians' ethical obligations; and (3) aligns with the approach in the Vaccine Adverse Event Reporting System (VAERS). Furthermore, advances in electronic health records can aid in reporting efficiency.

  11. Attractors and basins of dynamical systems

    Directory of Open Access Journals (Sweden)

    Attila Dénes

    2011-03-01

    Full Text Available There are several programs for studying dynamical systems, but none of them is very useful for investigating basins and attractors of higher dimensional systems. Our goal in this paper is to show a new algorithm for finding even chaotic attractors and their basins for these systems. We present an implementation and examples for the use of this program.

  12. Healers, deities, saints and doctors: elements for the analysis of medical systems.

    Science.gov (United States)

    Pedersen, D; Baruffati, V

    1989-01-01

    This article provides the basic elements for the discussion and analysis of medical systems and their inter-dependency, with special reference to Latin America and, in particular, to the Andean countries. In a culturally diverse and socially stratified population, such as in contemporary Latin America, medical systems constitute a social representation resulting from the historical relationship between autochtonous medical cultures and those from other latitudes. The impregnation of scientific and popular knowledge results not only in the incorporation (and often expropriation) of folk in professional or scientific medicine, but also in the increasing 'medicalisation' of popular and traditional therapeutic practices. The emergent 'popular' medical system draws from both the professional and folk models, and in its actual practice, integrates both popular beliefs and materia medica with elements drawn from popular religions and pre-Hispanic deities. The degree of competitiveness, co-operation or 'integration' among medical systems depends mainly on the asymmetrical distribution of power and resources, and is conditioned by the population's behaviour in the management of disease. Existing pluralist systems of health care reveal a valuable array of survival strategies, which far outreach the proposals for integration called for by official sectors. On the other hand, knowledge derived from traditional medicine can contribute to the development of new models of clinical practice and to the expansion of the conventional epidemiological model.

  13. Dynamic Double Curvature Mould System

    DEFF Research Database (Denmark)

    Jepsen, Christian Raun; Kristensen, Mathias Kræmmergaard; Kirkegaard, Poul Henning

    2011-01-01

    The present paper describes a concept for a reconfigurable mould surface which is designed to fit the needs of contemporary architecture. The core of the concept presented is a dynamic surface manipulated into a given shape using a digital signal created directly from the CAD drawing of the design....... This happens fast, automatic and without production of waste, and the manipulated surface is fair and robust, eliminating the need for additional, manual treatment. Limitations to the possibilities of the flexible form are limited curvature and limited level of detail, making it especially suited for larger...

  14. Reinventing The Doctor

    Directory of Open Access Journals (Sweden)

    Moyez Jiwa

    2011-07-01

    Full Text Available There has been a seismic shift in the lives of people because of technology. People are far better informed than they were in the 1980s and 1990s. Much of this information is available through the media but even more is available and archived on the internet. The forces pushing the internet into health and health care are strong and unstoppable, ensuring that the internet and the choices it offers must be part of the design of our future health care system. We are no longer content to wait in queues as we live at a faster pace than earlier generations — we don’t not have time to wait for appointments months, weeks or even days in advance. The internet offers the prospect of online consultations in the comfort of your own home. The physical examination will change as new devices are developed to allow the necessary sounds and signals emitted by our malfunctioning bodies to be recorded, interpreted and captured at a remote location. Meanwhile, for those who prefer to see a health care practitioner in person the options to consult practitioners other than doctors who can advise on our health is expanding. The reality is we can’t afford to train or pay for all the doctors we need under the current “doctor-knows-best” system of health care. Patients no longer believe the rhetoric and are already voting with their feet. Pharmacists, nurses and other allied health professionals are beginning to play a much greater role in offering relief from symptoms and monitoring of chronic diseases. Of course, the doctor of the future will still need to offer face-to-face consultations to some people most of the time or most people some of the time. The social role doctors play will continue to be important as humans will always need other humans to personally respond to their distress. As doctors reinvent themselves, the internet and the value of time with patients will be the driving forces that move us into a more sustainable future in health care.

  15. Dynamics and control of technical systems

    CERN Document Server

    Balthazar, José M; Kaczmarczyk, Stefan

    2014-01-01

    The main topics of this Special Issue are linear and, mainly, nonlinear dynamics, chaos and control of systems and structures and their applications in different field of science and engineering. According to the goal of the Special Issue, the selected contributions are divided into three major parts: ""Vibration Problems in Vertical Transportation Systems"", ""Nonlinear Dynamics, Chaos and Control of Elastic Structures"" and ""New Strategies and Challenges for Aerospace and Ocean Structures Dynamics and Control"". The discussion of real problems in aerospace and how these problems can be unde

  16. The structure and process of workers' compensation systems and the role of doctors: A comparison of Ontario and Québec.

    Science.gov (United States)

    Lippel, Katherine; Eakin, Joan M; Holness, D Linn; Howse, Dana

    2016-12-01

    This study sought to identify impacts of compensation system characteristics on doctors in Québec and Ontario. (i) Legal analysis; (ii) Qualitative methods applied to documentation and individual and group interviews with doctors (34) and other system participants (31); and (iii) Inter-jurisdictional transdisciplinary analysis involving cross-disciplinary comparative and integrative analysis of policy contexts, qualitative data, and the relationship between the two. In both jurisdictions the compensation board controlled decisions on work-relatedness and doctors perceived the bureaucratic process negatively. Gatekeeping roles differed between jurisdictions both in initial adjudication and in dispute processes. Québec legislation gives greater weight to the opinion of the treating physician. These differences affected doctors' experiences. Policy-makers should contextualize the sources of the "evidence" they rely on from intervention research because findings may reflect a system rather than an intervention effect. Researchers should consider policy contexts to both adequately design a study and interpret their results. Am. J. Ind. Med. 59:1070-1086, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  17. Dynamical systems examples of complex behaviour

    CERN Document Server

    Jost, Jürgen

    2005-01-01

    Our aim is to introduce, explain, and discuss the fundamental problems, ideas, concepts, results, and methods of the theory of dynamical systems and to show how they can be used in speci?c examples. We do not intend to give a comprehensive overview of the present state of research in the theory of dynamical systems, nor a detailed historical account of its development. We try to explain the important results, often neglecting technical re?nements 1 and, usually, we do not provide proofs. One of the basic questions in studying dynamical systems, i.e. systems that evolve in time, is the construction of invariants that allow us to classify qualitative types of dynamical evolution, to distinguish between qualitatively di?erent dynamics, and to studytransitions between di?erent types. Itis also important to ?nd out when a certain dynamic behavior is stable under small perturbations, as well as to understand the various scenarios of instability. Finally, an essential aspect of a dynamic evolution is the transformat...

  18. Dynamic Modeling of Solar Dynamic Components and Systems

    Science.gov (United States)

    Hochstein, John I.; Korakianitis, T.

    1992-01-01

    The purpose of this grant was to support NASA in modeling efforts to predict the transient dynamic and thermodynamic response of the space station solar dynamic power generation system. In order to meet the initial schedule requirement of providing results in time to support installation of the system as part of the initial phase of space station, early efforts were executed with alacrity and often in parallel. Initially, methods to predict the transient response of a Rankine as well as a Brayton cycle were developed. Review of preliminary design concepts led NASA to select a regenerative gas-turbine cycle using a helium-xenon mixture as the working fluid and, from that point forward, the modeling effort focused exclusively on that system. Although initial project planning called for a three year period of performance, revised NASA schedules moved system installation to later and later phases of station deployment. Eventually, NASA selected to halt development of the solar dynamic power generation system for space station and to reduce support for this project to two-thirds of the original level.

  19. Introduction to Chaotic Dynamical Systems

    Science.gov (United States)

    1992-12-01

    differential equations to first order systems see Borrelli - Coleman (Ref. 2]. 4 The general form of a linear system of differential equations is x,’ at...pendulum. The process of finding the ex- plicit solution to this system of differential equations is described in Borrelli - Coleman [Ref. 2]. 9 0...independent eigenvectors. The details can be found in Borrelli - Coleman [Ref. 2] and Boyce-DiPrima [Ref. 5]. The c, are determined once an initial

  20. Doctors' opinion on the contribution of coordination mechanisms to improving clinical coordination between primary and outpatient secondary care in the Catalan national health system.

    Science.gov (United States)

    Aller, Marta-Beatriz; Vargas, Ingrid; Coderch, Jordi; Vázquez, Maria-Luisa

    2017-12-22

    Clinical coordination is considered a health policy priority as its absence can lead to poor quality of care and inefficiency. A key challenge is to identify which strategies should be implemented to improve coordination. The aim is to analyse doctors' opinions on the contribution of mechanisms to improving clinical coordination between primary and outpatient secondary care and the factors influencing their use. A qualitative descriptive study in three healthcare networks of the Catalan national health system. A two-stage theoretical sample was designed: in the first stage, networks with different management models were selected; in the second, primary care (n = 26) and secondary care (n = 24) doctors. Data were collected using semi-structured interviews. Final sample size was reached by saturation. A thematic content analysis was conducted, segmented by network and care level. With few differences across networks, doctors identified similar mechanisms contributing to clinical coordination: 1) shared EMR facilitating clinical information transfer and uptake; 2) mechanisms enabling problem-solving communication and agreement on clinical approaches, which varied across networks (joint clinical case conferences, which also promote mutual knowledge and training of primary care doctors; virtual consultations through EMR and email); and 3) referral protocols and use of the telephone facilitating access to secondary care after referrals. Doctors identified organizational (insufficient time, incompatible timetables, design of mechanisms) and professional factors (knowing each other, attitude towards collaboration, concerns over misdiagnosis) that influence the use of mechanisms. Mechanisms that most contribute to clinical coordination are feedback mechanisms, that is those based on mutual adjustment, that allow doctors to exchange information and communicate. Their use might be enhanced by focusing on adequate working conditions, mechanism design and creating

  1. System dynamics an introduction for mechanical engineers

    CERN Document Server

    Seeler, Karl A

    2014-01-01

    This essential textbook takes the student from the initial steps in modeling a dynamic system through development of the mathematical models needed for feedback control.  The generously-illustrated, student-friendly text focuses on fundamental theoretical development rather than the application of commercial software.  Practical details of machine design are included to motivate the non-mathematically inclined student. This book also: Emphasizes the linear graph method for modeling dynamic systems Offers a systematic approach for creating an engineering model, extracting information, and formulating mathematical analyses Adopts a unifying theme of power flow as the dynamic agent that eases analysis of hybrid systems, such as machinery Presents differential equations as dynamic operators and stresses input/output relationships Introduces Mathcad and programming in MATLAB Allows for use of Open Source Computational Software (R or C) Features over 1000 illustrations

  2. Doctors' involvement in torture.

    Science.gov (United States)

    Jesper, Sonntag

    2008-01-01

    Doctors from both non-democratic and democratic countries are involved in torture. The majority of doctors involved in torture are doctors at risk. Doctors at risk might compromise their ethical duty towards patients for the following possible reasons: individual factors (such as career, economic or ideological reasons), threats, orders from a higher ranking officer, political initiatives, working in atrocity-producing situations or dual loyalty. In dual loyalty conflicts, factors that might compromise doctors' ethical obligations towards detainees/patients are: ideological totalitarianism, moral disengagement, victim blame, patriotism, individual factors or threats. Another important reason why doctors are involved in torture is that not all doctors are trained in addressing human rights issues of detainees. Torture survivors report that they have experienced doctors' involvement in torture and doctors themselves report that they have been involved in torture. Testimonies from both torture survivors and doctors demonstrate that the most common way doctors are involved is in the diagnosis/medical examination of torture survivors/prisoners. And it is common before, during and after torture. Both torture survivors and doctors state that doctors are involved during torture by treatment and direct participation. Doctors also falsify journals, certificates and reports. When doctors are involved in torture it has devastating consequences for both torture survivors and doctors. The consequences for the survivors can be mistrust of doctors, avoidance of seeking doctors' help and nightmares involving doctors. Mistrust and avoidance of doctors could be especially fatal to the survivor, as it could mean a survivor who is ill may not seek medical attention. When the unambiguous role of the doctor as the protector and helper of people is questioned, it affects the medical profession all over the world.

  3. System crash as dynamics of complex networks.

    Science.gov (United States)

    Yu, Yi; Xiao, Gaoxi; Zhou, Jie; Wang, Yubo; Wang, Zhen; Kurths, Jürgen; Schellnhuber, Hans Joachim

    2016-10-18

    Complex systems, from animal herds to human nations, sometimes crash drastically. Although the growth and evolution of systems have been extensively studied, our understanding of how systems crash is still limited. It remains rather puzzling why some systems, appearing to be doomed to fail, manage to survive for a long time whereas some other systems, which seem to be too big or too strong to fail, crash rapidly. In this contribution, we propose a network-based system dynamics model, where individual actions based on the local information accessible in their respective system structures may lead to the "peculiar" dynamics of system crash mentioned above. Extensive simulations are carried out on synthetic and real-life networks, which further reveal the interesting system evolution leading to the final crash. Applications and possible extensions of the proposed model are discussed.

  4. Controlling dynamics in diatomic systems

    Indian Academy of Sciences (India)

    WINTEC

    2Center for Computational Natural Sciences and Bioinformatics,. International Institute of Information Technology, Hyderabad 500 032 ..... journal.34. 3. The control system. We have chosen two diatomic systems for studying the vibrational excitations from an initial state to a target state in a Morse potential of the HF and OH.

  5. Dynamics of the solar system

    International Nuclear Information System (INIS)

    Sidlichovsky, M.

    1987-01-01

    The conference proceedings contains a total of 31 papers of which 7 have not been incorporated in INIS. The papers mainly discuss the mathematical methods of calculating the movement of planets, their satellites and asteroids in the solar system and the mathematical modelling of the past development of the solar system. Great attention is also devoted to resonance in the solar system and to the study of many celestial bodies. Four papers are devoted to planetary rings and three to modern astrometry. (M.D.). 63 figs., 10 tabs., 520 refs

  6. Hybrid dynamical systems observation and control

    CERN Document Server

    Defoort, Michael

    2015-01-01

    This book is a collection of contributions defining the state of current knowledge and new trends in hybrid systemssystems involving both continuous dynamics and discrete events – as described by the work of several well-known groups of researchers. Hybrid Dynamical Systems presents theoretical advances in such areas as diagnosability, observability and stabilization for various classes of system. Continuous and discrete state estimation and self-triggering control of nonlinear systems are advanced. The text employs various methods, among them, high-order sliding modes, Takagi–Sugeno representation and sampled-data switching to achieve its ends. The many applications of hybrid systems from power converters to computer science are not forgotten; studies of flexible-joint robotic arms and – as representative biological systems – the behaviour of the human heart and vasculature, demonstrate the wide-ranging practical significance of control in hybrid systems. The cross-disciplinary origins of study ...

  7. Topological theory of dynamical systems recent advances

    CERN Document Server

    Aoki, N

    1994-01-01

    This monograph aims to provide an advanced account of some aspects of dynamical systems in the framework of general topology, and is intended for use by interested graduate students and working mathematicians. Although some of the topics discussed are relatively new, others are not: this book is not a collection of research papers, but a textbook to present recent developments of the theory that could be the foundations for future developments. This book contains a new theory developed by the authors to deal with problems occurring in diffentiable dynamics that are within the scope of general topology. To follow it, the book provides an adequate foundation for topological theory of dynamical systems, and contains tools which are sufficiently powerful throughout the book. Graduate students (and some undergraduates) with sufficient knowledge of basic general topology, basic topological dynamics, and basic algebraic topology will find little difficulty in reading this book.

  8. Controllable Subspaces of Open Quantum Dynamical Systems

    International Nuclear Information System (INIS)

    Zhang Ming; Gong Erling; Xie Hongwei; Hu Dewen; Dai Hongyi

    2008-01-01

    This paper discusses the concept of controllable subspace for open quantum dynamical systems. It is constructively demonstrated that combining structural features of decoherence-free subspaces with the ability to perform open-loop coherent control on open quantum systems will allow decoherence-free subspaces to be controllable. This is in contrast to the observation that open quantum dynamical systems are not open-loop controllable. To a certain extent, this paper gives an alternative control theoretical interpretation on why decoherence-free subspaces can be useful for quantum computation.

  9. Biomechanics of posterior dynamic stabilization systems.

    Science.gov (United States)

    Erbulut, D U; Zafarparandeh, I; Ozer, A F; Goel, V K

    2013-01-01

    Spinal rigid instrumentations have been used to fuse and stabilize spinal segments as a surgical treatment for various spinal disorders to date. This technology provides immediate stability after surgery until the natural fusion mass develops. At present, rigid fixation is the current gold standard in surgical treatment of chronic back pain spinal disorders. However, such systems have several drawbacks such as higher mechanical stress on the adjacent segment, leading to long-term degenerative changes and hypermobility that often necessitate additional fusion surgery. Dynamic stabilization systems have been suggested to address adjacent segment degeneration, which is considered to be a fusion-associated phenomenon. Dynamic stabilization systems are designed to preserve segmental stability, to keep the treated segment mobile, and to reduce or eliminate degenerative effects on adjacent segments. This paper aimed to describe the biomechanical aspect of dynamic stabilization systems as an alternative treatment to fusion for certain patients.

  10. Biomechanics of Posterior Dynamic Stabilization Systems

    Directory of Open Access Journals (Sweden)

    D. U. Erbulut

    2013-01-01

    Full Text Available Spinal rigid instrumentations have been used to fuse and stabilize spinal segments as a surgical treatment for various spinal disorders to date. This technology provides immediate stability after surgery until the natural fusion mass develops. At present, rigid fixation is the current gold standard in surgical treatment of chronic back pain spinal disorders. However, such systems have several drawbacks such as higher mechanical stress on the adjacent segment, leading to long-term degenerative changes and hypermobility that often necessitate additional fusion surgery. Dynamic stabilization systems have been suggested to address adjacent segment degeneration, which is considered to be a fusion-associated phenomenon. Dynamic stabilization systems are designed to preserve segmental stability, to keep the treated segment mobile, and to reduce or eliminate degenerative effects on adjacent segments. This paper aimed to describe the biomechanical aspect of dynamic stabilization systems as an alternative treatment to fusion for certain patients.

  11. Dynamic Properties of Impulse Measuring Systems

    DEFF Research Database (Denmark)

    Pedersen, A.; Lausen, P.

    1971-01-01

    After some basic considerations the dynamic properties of the measuring system are subjected to a general examination based on a number of responses, characteristic of the system. It is demonstrated that an impulse circuit has an internal impedance different from zero, for which reason...

  12. Dynamic Systems Theory and Team Sport Coaching

    Science.gov (United States)

    Gréhaigne, Jean-Francis; Godbout, Paul

    2014-01-01

    This article examines the theory of dynamic systems and its use in the domains of the study and coaching of team sports. The two teams involved in a match are looked at as two interacting systems in movement, where opposition is paramount. A key element for the observation of game play is the notion of configuration of play and its ever-changing…

  13. Chaotic dynamics in N-body systems

    NARCIS (Netherlands)

    Boekholt, Tjarda Coenraad Nico

    2015-01-01

    Ever since Isaac Newton in 1687 posed the N-body problem, astronomers have been looking for its solutions in order to understand the evolution of dynamical systems, such as our own solar system, star clusters and galaxies. The main difficulty is that small errors grow exponentially, so that

  14. Bifurcation methods of dynamical systems for generalized ...

    Indian Academy of Sciences (India)

    Compacton solution; periodic wave solution; periodic cusp wave solution; generalized KP-BBM equation. Abstract. By applying the bifurcation theory of dynamical system to the generalized KP-BBM equation, the phase portraits of the travelling wave system are obtained. It can be shown that singular straight line in the ...

  15. Reaction dynamics in polyatomic molecular systems

    Energy Technology Data Exchange (ETDEWEB)

    Miller, W.H. [Lawrence Berkeley Laboratory, CA (United States)

    1993-12-01

    The goal of this program is the development of theoretical methods and models for describing the dynamics of chemical reactions, with specific interest for application to polyatomic molecular systems of special interest and relevance. There is interest in developing the most rigorous possible theoretical approaches and also in more approximate treatments that are more readily applicable to complex systems.

  16. Dynamic modeling of the INAPRO aquaponic system

    NARCIS (Netherlands)

    Karimanzira, Divas; Keesman, Karel J.; Kloas, Werner; Baganz, Daniela; Rauschenbach, Thomas

    2016-01-01

    The use of modeling techniques to analyze aquaponics systems is demonstrated with an example of dynamic modeling for the production of Nile tilapia (Oreochromis niloticus) and tomatoes (Solanum lycopersicon) using the innovative double recirculating aquaponic system ASTAF-PRO. For the management

  17. Dynamic Ultrasonography in Musculoskeletal System -Upper Extremity

    Energy Technology Data Exchange (ETDEWEB)

    Rho, Byung Hak; Lee, Sung Moon [Keimyung University School of Medicine, Daegu (Korea, Republic of)

    2009-03-15

    With technical advances, ultrasonography of musculoskeletal system has been an important imaging modality in variable disorders and has been popular. Real-time imaging and possible dynamic motion study are special advantages of ultrasonography, and particularly helpful in evaluation of tendon or ligament injury. The purpose of this article is to review the basic technique and disorders that dynamic ultrasonography is helpful or essential in diagnosis in upper extremity

  18. Coherent regimes of globally coupled dynamical systems

    DEFF Research Database (Denmark)

    de Monte, Silvia; D'ovidio, Francesco; Mosekilde, Erik

    2003-01-01

    This Letter presents a method by which the mean field dynamics of a population of dynamical systems with parameter diversity and global coupling can be described in terms of a few macroscopic degrees of freedom. The method applies to populations of any size and functional form in the region of co...... of oscillator death and the route to full locking are examined for chaotic oscillators with time scale mismatch....

  19. Solar dynamic power system definition study

    Science.gov (United States)

    Wallin, Wayne E.; Friefeld, Jerry M.

    1988-01-01

    The solar dynamic power system design and analysis study compared Brayton, alkali-metal Rankine, and free-piston Stirling cycles with silicon planar and GaAs concentrator photovoltaic power systems for application to missions beyond the Phase 2 Space Station level of technology for all power systems. Conceptual designs for Brayton and Stirling power systems were developed for 35 kWe and 7 kWe power levels. All power systems were designed for 7-year end-of-life conditions in low Earth orbit. LiF was selected for thermal energy storage for the solar dynamic systems. Results indicate that the Stirling cycle systems have the highest performance (lowest weight and area) followed by the Brayton cycle, with photovoltaic systems considerably lower in performance. For example, based on the performance assumptions used, the planar silicon power system weight was 55 to 75 percent higher than for the Stirling system. A technology program was developed to address areas wherein significant performance improvements could be realized relative to the current state-of-the-art as represented by Space Station. In addition, a preliminary evaluation of hardenability potential found that solar dynamic systems can be hardened beyond the hardness inherent in the conceptual designs of this study.

  20. Dynamic Systems Modeling in Educational System Design & Policy

    Science.gov (United States)

    Groff, Jennifer Sterling

    2013-01-01

    Over the last several hundred years, local and national educational systems have evolved from relatively simple systems to incredibly complex, interdependent, policy-laden structures, to which many question their value, effectiveness, and direction they are headed. System Dynamics is a field of analysis used to guide policy and system design in…

  1. On Doctoral Student Development: Exploring Faculty Mentoring in the Shaping of African American Doctoral Student Success

    Science.gov (United States)

    Felder, Pamela

    2010-01-01

    This study examines the influence of faculty mentorship in the shaping of African American doctoral student success. A case analysis framework is used to investigate the belief systems that doctoral students held about their doctoral experience. Data collection involved a one-phase semi-structured interview protocol used to gather information…

  2. Discrete dynamics of complex systems

    Directory of Open Access Journals (Sweden)

    Hermann Haken

    1997-01-01

    Full Text Available This article extends the slaving principle of synergetics to processes with discrete time steps. Starting point is a set of nonlinear difference equations which contain multiplicative noise and which refer to multidimensional state vectors. The system depends on a control parameter. When its value is changed beyond a critical value, an instability of the solution occurs. The stability analysis allows us to divide the system into stable and unstable modes. The original equations can be transformed to a set of difference equations for the unstable and stable modes. The extension of the slaving principle to the time-discrete case then states that all the stable modes can be explicitly expressed by the unstable modes or so-called order-parameters.

  3. Coaching doctoral students

    DEFF Research Database (Denmark)

    Godskesen, Mirjam Irene; Kobayashi, Sofie

    2016-01-01

    In this paper we focus on individual coaching carried out by an external coach as a new pedagogical element that can impact doctoral students’ sense of progress in doctoral education. The study used a mixed methods approach in that we draw on quantitative and qualitative data from the evaluation...... of a project on coaching doctoral students. We explore how coaching can contribute to the doctoral students’ development of a broad set of personal competences and suggest that coaching could work as a means to engender self-management and improve relational competences. The analysis of the participants’ self......-reported gains from coaching show that doctoral students experience coaching as an effective method to support the doctoral study process. This study also provides preliminary empirical evidence that coaching of doctoral students can facilitate the doctoral study process so that the doctoral students experience...

  4. Geometric theory of discrete nonautonomous dynamical systems

    CERN Document Server

    Pötzsche, Christian

    2010-01-01

    Nonautonomous dynamical systems provide a mathematical framework for temporally changing phenomena, where the law of evolution varies in time due to seasonal, modulation, controlling or even random effects. Our goal is to provide an approach to the corresponding geometric theory of nonautonomous discrete dynamical systems in infinite-dimensional spaces by virtue of 2-parameter semigroups (processes). These dynamical systems are generated by implicit difference equations, which explicitly depend on time. Compactness and dissipativity conditions are provided for such problems in order to have attractors using the natural concept of pullback convergence. Concerning a necessary linear theory, our hyperbolicity concept is based on exponential dichotomies and splittings. This concept is in turn used to construct nonautonomous invariant manifolds, so-called fiber bundles, and deduce linearization theorems. The results are illustrated using temporal and full discretizations of evolutionary differential equations.

  5. A DYNAMIC SIMULATION OF REVERSE OSMOSIS SYSTEMS

    OpenAIRE

    Armijo C., J.; Departamento Académico de Operaciones Unitarias, Facultad de Q. e Ing. Química, Universidad Nacional Mayor de San Marcos Lima, Perú; Condorhuamán C., C.; Departamento Académico de Operaciones Unitarias, Facultad de Q. e Ing. Química Universidad Nacional Mayor de San Marcos Lima, Perú

    2014-01-01

    This paper develops a mathematical model to simulate dynamically a reverse osmosis system. The model is formed from materials balances macroscopic unsteady state combined with the model membrane transport: diffusion-solution. In this first part, we solve the system of differential equations assuming a completely mixed flow pattern in the reverse osmosis module (module polarization = 1). The system of equations is solved simultaneously by the Runge-Kutta-Fehlberg method. The results indicate t...

  6. New slip control system considering actuator dynamics

    OpenAIRE

    Soltani, Amirmasoud; Assadian, Francis

    2015-01-01

    A new control strategy for wheel slip control, considering the complete dynamics of the electro-hydraulic brake (EHB) system, is developed and experimentally validated in Cranfield University's HiL system. The control system is based on closed loop shaping Youla-parameterization method. The plant model is linearized about the nominal operating point, a Youla parameter is defined for all stabilizing feedback controller and control performance is achieved by employing closed loop shaping techni...

  7. Connecting micro dynamics and population distributions in system dynamics models.

    Science.gov (United States)

    Fallah-Fini, Saeideh; Rahmandad, Hazhir; Chen, Hsin-Jen; Xue, Hong; Wang, Youfa

    2013-01-01

    Researchers use system dynamics models to capture the mean behavior of groups of indistinguishable population elements (e.g., people) aggregated in stock variables. Yet, many modeling problems require capturing the heterogeneity across elements with respect to some attribute(s) (e.g., body weight). This paper presents a new method to connect the micro-level dynamics associated with elements in a population with the macro-level population distribution along an attribute of interest without the need to explicitly model every element. We apply the proposed method to model the distribution of Body Mass Index and its changes over time in a sample population of American women obtained from the U.S. National Health and Nutrition Examination Survey. Comparing the results with those obtained from an individual-based model that captures the same phenomena shows that our proposed method delivers accurate results with less computation than the individual-based model.

  8. Connecting micro dynamics and population distributions in system dynamics models

    Science.gov (United States)

    Rahmandad, Hazhir; Chen, Hsin-Jen; Xue, Hong; Wang, Youfa

    2014-01-01

    Researchers use system dynamics models to capture the mean behavior of groups of indistinguishable population elements (e.g., people) aggregated in stock variables. Yet, many modeling problems require capturing the heterogeneity across elements with respect to some attribute(s) (e.g., body weight). This paper presents a new method to connect the micro-level dynamics associated with elements in a population with the macro-level population distribution along an attribute of interest without the need to explicitly model every element. We apply the proposed method to model the distribution of Body Mass Index and its changes over time in a sample population of American women obtained from the U.S. National Health and Nutrition Examination Survey. Comparing the results with those obtained from an individual-based model that captures the same phenomena shows that our proposed method delivers accurate results with less computation than the individual-based model. PMID:25620842

  9. Nonlinear Dynamics, Chaotic and Complex Systems

    Science.gov (United States)

    Infeld, E.; Zelazny, R.; Galkowski, A.

    2011-04-01

    Part I. Dynamic Systems Bifurcation Theory and Chaos: 1. Chaos in random dynamical systems V. M. Gunldach; 2. Controlling chaos using embedded unstable periodic orbits: the problem of optimal periodic orbits B. R. Hunt and E. Ott; 3. Chaotic tracer dynamics in open hydrodynamical flows G. Karolyi, A. Pentek, T. Tel and Z. Toroczkai; 4. Homoclinic chaos L. P. Shilnikov; Part II. Spatially Extended Systems: 5. Hydrodynamics of relativistic probability flows I. Bialynicki-Birula; 6. Waves in ionic reaction-diffusion-migration systems P. Hasal, V. Nevoral, I. Schreiber, H. Sevcikova, D. Snita, and M. Marek; 7. Anomalous scaling in turbulence: a field theoretical approach V. Lvov and I. Procaccia; 8. Abelian sandpile cellular automata M. Markosova; 9. Transport in an incompletely chaotic magnetic field F. Spineanu; Part III. Dynamical Chaos Quantum Physics and Foundations Of Statistical Mechanics: 10. Non-equilibrium statistical mechanics and ergodic theory L. A. Bunimovich; 11. Pseudochaos in statistical physics B. Chirikov; 12. Foundations of non-equilibrium statistical mechanics J. P. Dougherty; 13. Thermomechanical particle simulations W. G. Hoover, H. A. Posch, C. H. Dellago, O. Kum, C. G. Hoover, A. J. De Groot and B. L. Holian; 14. Quantum dynamics on a Markov background and irreversibility B. Pavlov; 15. Time chaos and the laws of nature I. Prigogine and D. J. Driebe; 16. Evolutionary Q and cognitive systems: dynamic entropies and predictability of evolutionary processes W. Ebeling; 17. Spatiotemporal chaos information processing in neural networks H. Szu; 18. Phase transitions and learning in neural networks C. Van den Broeck; 19. Synthesis of chaos A. Vanecek and S. Celikovsky; 20. Computational complexity of continuous problems H. Wozniakowski; Part IV. Complex Systems As An Interface Between Natural Sciences and Environmental Social and Economic Sciences: 21. Stochastic differential geometry in finance studies V. G. Makhankov; Part V. Conference Banquet

  10. EXTRAP as a dynamic system

    International Nuclear Information System (INIS)

    Tendler, M.

    1986-04-01

    The behaviour of the plasma in the EXTRAP device was found to differ drastically from the conventional Z-pinch discharges. The comparative discussion on the properties of these two configurations is presented. It is shown that the energy mechanism is responsible for the arising difference between them. Given the lack of experimental data on the confinement of the peripheral plasma, in the present study we suggest a scaling for the net energy loss with plasma density and temperature. Using self-similar methods, we show that strongly non-linear damped oscillations arise as a result of our scaling. Some preliminary results on the stability of this system are reported. Finally, some technical recommendations for the design of the toroidal device EXTRAP T1 are put forward. In particular the scheme, allowing the extension of the pulse duration, which is rather limited in the present version, is suggested. (Author)

  11. Canadian family doctors' roles and responsibilities toward outbound medical tourists: "Our true role is ... within the confines of our system".

    Science.gov (United States)

    Johnston, Rory; Crooks, Valorie A; Snyder, Jeremy; Dharamsi, Shafik

    2013-12-01

    To explore how Canadian family doctors understand their roles and responsibilities toward patients who seek health care abroad. Six focus groups were held with family doctors across British Columbia to explore their experiences with and perspectives on outbound medical tourism. Focus groups were digitally recorded, transcribed, and subsequently thematically coded to discover common issues and themes across the entire data set. Focus groups were held with family doctors in 6 cities in British Columbia that provided representation from all provincial health authorities and a range of urban contexts. A total of 22 currently practising family doctors participated across the 6 focus groups, with groups ranging in size from 2 to 6 participants (average 4 participants). Thematic analysis of the transcripts identified cross-cutting themes that emerged across the 6 focus groups. Participants reported that medical tourism threatened patients' continuity of care. Informational continuity is disrupted before patients go abroad because patients regularly omit family doctors from preoperative planning and upon return home when patients lack complete or translated medical reports. Participants believed that their responsibilities to patients resumed once the patients had returned home from care abroad, but were worried about not being able to provide adequate follow-up care. Participants were also concerned about bearing legal liability toward patients should they be asked to clinically support treatments started abroad. Medical tourism poses challenges to Canadian family doctors when trying to reconcile their traditional roles and responsibilities with the novel demands of private out-of-country care pursued by their patients. Guidance from professional bodies regarding physicians' responsibilities to Canadian medical tourists is currently lacking. Developing these supports would help address challenges faced in clinical practice.

  12. Beyond Proximity: Consequentialist Ethics and System Dynamics

    OpenAIRE

    Palmer, Erika

    2017-01-01

    Consequentialism is a moral philosophy that maintains that the moral worth of an action is determined by the consequences it has for the welfare of a society. Consequences of model design are a part of the model lifecycle that is often neglected. This paper investigates the issue using system dynamics modeling as an example. Since a system dynamics model is a product of the modeler’s design decisions, the modeler should consider the life cycle consequences of using the model. Seen from a cons...

  13. Dynamics of shuttle based flexible antenna system

    Science.gov (United States)

    Moch, M.; Kirk, C. L.

    1992-01-01

    The Lagrangian approach was used to model a complex flexible antenna/astromast system. In order to keep the open and closed loop dynamic models to a reasonable size a reduced model with four degrees of freedom was selected. The possibility of using the DC servomotor in a closed loop system, to damp the oscillations produced by the step function motors' torque (required for acceleration and deceleration), was investigated. Using the dynamical model, an open loop pitching maneuver was simulated, eigenvalue analysis was applied, and residual oscillations at the end of the maneuver were damped out by the DC servomotor using closed loop feedback control.

  14. Topological equivalence of nonlinear autonomous dynamical systems

    International Nuclear Information System (INIS)

    Nguyen Huynh Phan; Tran Van Nhung

    1995-12-01

    We show in this paper that the autonomous nonlinear dynamical system Σ(A,B,F): x' = Ax+Bu+F(x) is topologically equivalent to the linear dynamical system Σ(A,B,O): x' = Ax+Bu if the projection of A on the complement in R n of the controllable vectorial subspace is hyperbolic and if lipschitz constant of F is sufficiently small ( * ) and F(x) = 0 when parallel x parallel is sufficiently large ( ** ). In particular, if Σ(A,B,O) is controllable, it is topologically equivalent to Σ(A,B,F) when it is only that F satisfy ( ** ). (author). 18 refs

  15. Very Large System Dynamics Models - Lessons Learned

    Energy Technology Data Exchange (ETDEWEB)

    Jacob J. Jacobson; Leonard Malczynski

    2008-10-01

    This paper provides lessons learned from developing several large system dynamics (SD) models. System dynamics modeling practice emphasize the need to keep models small so that they are manageable and understandable. This practice is generally reasonable and prudent; however, there are times that large SD models are necessary. This paper outlines two large SD projects that were done at two Department of Energy National Laboratories, the Idaho National Laboratory and Sandia National Laboratories. This paper summarizes the models and then discusses some of the valuable lessons learned during these two modeling efforts.

  16. Doctoral Women: Managing Emotions, Managing Doctoral Studies

    Science.gov (United States)

    Aitchison, Claire; Mowbray, Susan

    2013-01-01

    This paper explores the experiences of women doctoral students and the role of emotion during doctoral candidature. The paper draws on the concept of emotional labour to examine the two sites of emotional investment students experienced and managed during their studies: writing and family relationships. Emotion is perceived by many dominant…

  17. Complex and Adaptive Dynamical Systems A Primer

    CERN Document Server

    Gros, Claudius

    2011-01-01

    We are living in an ever more complex world, an epoch where human actions can accordingly acquire far-reaching potentialities. Complex and adaptive dynamical systems are ubiquitous in the world surrounding us and require us to adapt to new realities and the way of dealing with them. This primer has been developed with the aim of conveying a wide range of "commons-sense" knowledge in the field of quantitative complex system science at an introductory level, providing an entry point to this both fascinating and vitally important subject. The approach is modular and phenomenology driven. Examples of emerging phenomena of generic importance treated in this book are: -- The small world phenomenon in social and scale-free networks. -- Phase transitions and self-organized criticality in adaptive systems. -- Life at the edge of chaos and coevolutionary avalanches resulting from the unfolding of all living. -- The concept of living dynamical systems and emotional diffusive control within cognitive system theory. Techn...

  18. Complex and adaptive dynamical systems a primer

    CERN Document Server

    Gros, Claudius

    2007-01-01

    We are living in an ever more complex world, an epoch where human actions can accordingly acquire far-reaching potentialities. Complex and adaptive dynamical systems are ubiquitous in the world surrounding us and require us to adapt to new realities and the way of dealing with them. This primer has been developed with the aim of conveying a wide range of "commons-sense" knowledge in the field of quantitative complex system science at an introductory level, providing an entry point to this both fascinating and vitally important subject. The approach is modular and phenomenology driven. Examples of emerging phenomena of generic importance treated in this book are: -- The small world phenomenon in social and scale-free networks. -- Phase transitions and self-organized criticality in adaptive systems. -- Life at the edge of chaos and coevolutionary avalanches resulting from the unfolding of all living. -- The concept of living dynamical systems and emotional diffusive control within cognitive system theory. Techn...

  19. Constraint Embedding Technique for Multibody System Dynamics

    Science.gov (United States)

    Woo, Simon S.; Cheng, Michael K.

    2011-01-01

    Multibody dynamics play a critical role in simulation testbeds for space missions. There has been a considerable interest in the development of efficient computational algorithms for solving the dynamics of multibody systems. Mass matrix factorization and inversion techniques and the O(N) class of forward dynamics algorithms developed using a spatial operator algebra stand out as important breakthrough on this front. Techniques such as these provide the efficient algorithms and methods for the application and implementation of such multibody dynamics models. However, these methods are limited only to tree-topology multibody systems. Closed-chain topology systems require different techniques that are not as efficient or as broad as those for tree-topology systems. The closed-chain forward dynamics approach consists of treating the closed-chain topology as a tree-topology system subject to additional closure constraints. The resulting forward dynamics solution consists of: (a) ignoring the closure constraints and using the O(N) algorithm to solve for the free unconstrained accelerations for the system; (b) using the tree-topology solution to compute a correction force to enforce the closure constraints; and (c) correcting the unconstrained accelerations with correction accelerations resulting from the correction forces. This constraint-embedding technique shows how to use direct embedding to eliminate local closure-loops in the system and effectively convert the system back to a tree-topology system. At this point, standard tree-topology techniques can be brought to bear on the problem. The approach uses a spatial operator algebra approach to formulating the equations of motion. The operators are block-partitioned around the local body subgroups to convert them into aggregate bodies. Mass matrix operator factorization and inversion techniques are applied to the reformulated tree-topology system. Thus in essence, the new technique allows conversion of a system with

  20. Cardea: Dynamic Access Control in Distributed Systems

    Science.gov (United States)

    Lepro, Rebekah

    2004-01-01

    Modern authorization systems span domains of administration, rely on many different authentication sources, and manage complex attributes as part of the authorization process. This . paper presents Cardea, a distributed system that facilitates dynamic access control, as a valuable piece of an inter-operable authorization framework. First, the authorization model employed in Cardea and its functionality goals are examined. Next, critical features of the system architecture and its handling of the authorization process are then examined. Then the S A M L and XACML standards, as incorporated into the system, are analyzed. Finally, the future directions of this project are outlined and connection points with general components of an authorization system are highlighted.

  1. DYNAMICS OF FRACTIONAL ORDER CHAOTIC SYSTEM

    Directory of Open Access Journals (Sweden)

    M. Jana

    2017-02-01

    Full Text Available This paper deals with the dynamics of chaos and synchronization for fractional order chaotic system. For fractional order derivative Captuo definition is used here and numerical simulations are done using Predictor-Correctors scheme by Diethlm based on the Adams-Baseforth-Moulton algorithm. Stability analysis is discussed here for non linear fractional order chaotic system and synchronization is achieved between two non identical fractional order chaotic systems: Finance chaotic system(driving systemand Lorenz system(response systemvia active control.Numerical simulations are performed to show the effectiveness of these approaches.

  2. Solar dynamic power systems for space station

    Science.gov (United States)

    Irvine, Thomas B.; Nall, Marsha M.; Seidel, Robert C.

    1986-01-01

    The Parabolic Offset Linearly Actuated Reflector (POLAR) solar dynamic module was selected as the baseline design for a solar dynamic power system aboard the space station. The POLAR concept was chosen over other candidate designs after extensive trade studies. The primary advantages of the POLAR concept are the low mass moment of inertia of the module about the transverse boom and the compactness of the stowed module which enables packaging of two complete modules in the Shuttle orbiter payload bay. The fine pointing control system required for the solar dynamic module has been studied and initial results indicate that if disturbances from the station are allowed to back drive the rotary alpha joint, pointing errors caused by transient loads on the space station can be minimized. This would allow pointing controls to operate in bandwidths near system structural frequencies. The incorporation of the fine pointing control system into the solar dynamic module is fairly straightforward for the three strut concentrator support structure. However, results of structural analyses indicate that this three strut support is not optimum. Incorporation of a vernier pointing system into the proposed six strut support structure is being studied.

  3. Operationalizing sustainability in urban coastal systems: a system dynamics analysis.

    Science.gov (United States)

    Mavrommati, Georgia; Bithas, Kostas; Panayiotidis, Panayiotis

    2013-12-15

    We propose a system dynamics approach for Ecologically Sustainable Development (ESD) in urban coastal systems. A systematic analysis based on theoretical considerations, policy analysis and experts' knowledge is followed in order to define the concept of ESD. The principles underlying ESD feed the development of a System Dynamics Model (SDM) that connects the pollutant loads produced by urban systems' socioeconomic activities with the ecological condition of the coastal ecosystem that it is delineated in operational terms through key biological elements defined by the EU Water Framework Directive. The receiving waters of the Athens Metropolitan area, which bears the elements of typical high population density Mediterranean coastal city but which currently has also new dynamics induced by the ongoing financial crisis, are used as an experimental system for testing a system dynamics approach to apply the concept of ESD. Systems' thinking is employed to represent the complex relationships among the components of the system. Interconnections and dependencies that determine the potentials for achieving ESD are revealed. The proposed system dynamics analysis can facilitate decision makers to define paths of development that comply with the principles of ESD. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Systemic banking crisis early warning systems using dynamic bayesian networks

    CSIR Research Space (South Africa)

    Dabrowski, JJ

    2016-11-01

    Full Text Available For decades, the literature on banking crisis early-warning systems has been dominated by two methods, namely, the signal extraction and the logit model methods. However, these methods, do not model the dynamics of the systemic banking system...

  5. Integrability of dynamical systems algebra and analysis

    CERN Document Server

    Zhang, Xiang

    2017-01-01

    This is the first book to systematically state the fundamental theory of integrability and its development of ordinary differential equations with emphasis on the Darboux theory of integrability and local integrability together with their applications. It summarizes the classical results of Darboux integrability and its modern development together with their related Darboux polynomials and their applications in the reduction of Liouville and elementary integrabilty and in the center—focus problem, the weakened Hilbert 16th problem on algebraic limit cycles and the global dynamical analysis of some realistic models in fields such as physics, mechanics and biology. Although it can be used as a textbook for graduate students in dynamical systems, it is intended as supplementary reading for graduate students from mathematics, physics, mechanics and engineering in courses related to the qualitative theory, bifurcation theory and the theory of integrability of dynamical systems.

  6. Brand Equity Evolution: a System Dynamics Model

    Directory of Open Access Journals (Sweden)

    Edson Crescitelli

    2009-04-01

    Full Text Available One of the greatest challenges in brand management lies in monitoring brand equity over time. This paper aimsto present a simulation model able to represent this evolution. The model was drawn on brand equity concepts developed by Aaker and Joachimsthaler (2000, using the system dynamics methodology. The use ofcomputational dynamic models aims to create new sources of information able to sensitize academics and managers alike to the dynamic implications of their brand management. As a result, an easily implementable model was generated, capable of executing continuous scenario simulations by surveying casual relations among the variables that explain brand equity. Moreover, the existence of a number of system modeling tools will allow extensive application of the concepts used in this study in practical situations, both in professional and educational settings

  7. Choosing a Family Doctor

    Science.gov (United States)

    ... and Birth Control Sex and Sexuality Birth Control Family Health Infants and Toddlers Kids and Teens Pregnancy ... Home Prevention and Wellness Staying Healthy Choosing a Family Doctor Choosing a Family Doctor Share Print What ...

  8. Invariant of dynamical systems: A generalized entropy

    International Nuclear Information System (INIS)

    Meson, A.M.; Vericat, F.

    1996-01-01

    In this work the concept of entropy of a dynamical system, as given by Kolmogorov, is generalized in the sense of Tsallis. It is shown that this entropy is an isomorphism invariant, being complete for Bernoulli schemes. copyright 1996 American Institute of Physics

  9. State dynamics of a double sandbar system

    NARCIS (Netherlands)

    Price, T.D.; Ruessink, B.G.

    2011-01-01

    A 9.3-year dataset of low-tide time-exposure images from Surfers Paradise, Northern Gold Coast, Australia was used to characterise the state dynamics of a double sandbar system. The morphology of the nearshore sandbars was described by means of the sequential bar state classification scheme of

  10. Dynamic control system voor verlengen kwaliteit

    NARCIS (Netherlands)

    Peppelenbos, H.W.

    2005-01-01

    Op het instituut Agrotechnology & Food Innovations van de universiteit Wageningen wordt onderzoek gedaan naar de beste condities waarbij producten vers blijven. Bijvoorbeeld bij Nederlandse appels: ze hebben één oogstmoment maar zijn dankzij het uitgekiende bewaarsysteem Dynamic Control System

  11. Induced topological pressure for topological dynamical systems

    International Nuclear Information System (INIS)

    Xing, Zhitao; Chen, Ercai

    2015-01-01

    In this paper, inspired by the article [J. Jaerisch et al., Stochastics Dyn. 14, 1350016, pp. 1-30 (2014)], we introduce the induced topological pressure for a topological dynamical system. In particular, we prove a variational principle for the induced topological pressure

  12. Improving homogeneity by dynamic speed limit systems.

    NARCIS (Netherlands)

    Nes, N. van Brandenberg, S. & Twisk, D.A.M.

    2010-01-01

    Homogeneity of driving speeds is an important variable in determining road safety; more homogeneous driving speeds increase road safety. This study investigates the effect of introducing dynamic speed limit systems on homogeneity of driving speeds. A total of 46 subjects twice drove a route along 12

  13. The Self as a Complex Dynamic System

    Science.gov (United States)

    Mercer, Sarah

    2011-01-01

    This article explores the potential offered by complexity theories for understanding language learners' sense of self and attempts to show how the self might usefully be conceived of as a complex dynamic system. Rather than presenting empirical findings, the article discusses existent research on the self and aims at outlining a conceptual…

  14. Stochastic properties of the Friedman dynamical system

    International Nuclear Information System (INIS)

    Szydlowski, M.; Heller, M.; Golda, Z.

    1985-01-01

    Some mathematical aspects of the stochastic cosmology are discussed in the corresponding ordinary Friedman world models. In particulare, it is shown that if the strong and Lorentz energy conditions are known, or the potential function is given, or a stochastic measure is suitably defined then the structure of the phase plane of the Friedman dynamical system is determined. 11 refs., 2 figs. (author)

  15. Geometric analysis of nondeterminacy in dynamical systems

    DEFF Research Database (Denmark)

    Wisniewski, Rafal; Raussen, Martin Hubert

    2007-01-01

    This article intends to provide some new insights into concurrency using ideas from the theory of dynamical systems. Inherently discrete concurrency corresponds to a parallel continuous concept: a discrete state space corresponds to a differential manifold, an execution path corresponds to a flow...

  16. Dynamic cellular manufacturing system design considering ...

    Indian Academy of Sciences (India)

    Kamal Deep

    tradeoff in a dynamic cellular manufacturing system is proposed in consideration with multiple part process route. This paper puts emphasize on the .... limited number of distinct paths considering resource capacity. The best routing is ..... all the other methods considered such as bond energy algorithm, direct clustering ...

  17. The dynamics of antilock brake systems

    Science.gov (United States)

    Denny, Mark

    2005-11-01

    The nonlinear dynamics of automobile braking are investigated. Nonlinearity arises because of the manner in which the friction coefficient between vehicle tyres and road surface depends upon vehicle speed and wheel angular speed. We show how antilock brake systems approach optimum braking performance.

  18. Abstraction of Dynamical Systems by Timed Automata

    DEFF Research Database (Denmark)

    Wisniewski, Rafael; Sloth, Christoffer

    2011-01-01

    To enable formal verification of a dynamical system, given by a set of differential equations, it is abstracted by a finite state model. This allows for application of methods for model checking. Consequently, it opens the possibility of carrying out the verification of reachability and timing re...

  19. Partial dynamical symmetry in a fermion system

    Science.gov (United States)

    Escher; Leviatan

    2000-02-28

    The relevance of the partial dynamical symmetry concept for an interacting fermion system is demonstrated. Hamiltonians with partial SU(3) symmetry are presented in the framework of the symplectic shell model of nuclei and shown to be closely related to the quadrupole-quadrupole interaction. Implications are discussed for the deformed light nucleus 20Ne.

  20. Learning Dynamics in Doctoral Supervision

    DEFF Research Database (Denmark)

    Kobayashi, Sofie

    investigates learning opportunities in supervision with multiple supervisors. This was investigated through observations and recording of supervision, and subsequent analysis of transcripts. The analyses used different perspectives on learning; learning as participation, positioning theory and variation theory....... The research illuminates how learning opportunities are created in the interaction through the scientific discussions. It also shows how multiple supervisors can contribute to supervision by providing new perspectives and opinions that have a potential for creating new understandings. The combination...... of different theoretical frameworks from the perspectives of learning as individual acquisition and a sociocultural perspective on learning contributed to a nuanced illustration of the otherwise implicit practices of supervision....

  1. Dynamics of quasi-stable dissipative systems

    CERN Document Server

    Chueshov, Igor

    2015-01-01

    This book is  devoted to background material and recently developed mathematical methods in the study of infinite-dimensional dissipative systems. The theory of such systems is motivated by the long-term goal to establish rigorous mathematical models for turbulent and chaotic phenomena. The aim here is to offer general methods and abstract results pertaining to fundamental dynamical systems properties related to dissipative long-time behavior. The book systematically presents, develops and uses the quasi-stability method while substantially extending it by including for consideration new classes of models and PDE systems arising in Continuum Mechanics. The book can be used as a textbook in dissipative dynamics at the graduate level.   Igor Chueshov is a Professor of Mathematics at Karazin Kharkov National University in Kharkov, Ukraine.

  2. A dynamically reconfigurable data stream processing system

    Energy Technology Data Exchange (ETDEWEB)

    Nogiec, J.M.; Trombly-Freytag, K.; /Fermilab

    2004-11-01

    This paper describes a component-based framework for data stream processing that allows for configuration, tailoring, and runtime system reconfiguration. The system's architecture is based on a pipes and filters pattern, where data is passed through routes between components. A network of pipes and filters can be dynamically reconfigured in response to a preplanned sequence of processing steps, operator intervention, or a change in one or more data streams. This framework provides several mechanisms supporting dynamic reconfiguration and can be used to build static data stream processing applications such as monitoring or data acquisition systems, as well as self-adjusting systems that can adapt their processing algorithm, presentation layer, or data persistency layer in response to changes in input data streams.

  3. Limitations of dynamic beam delivery systems

    International Nuclear Information System (INIS)

    Chu, W.T.; Kuenning, R.W.

    1987-01-01

    The heavy charged-particle beams which have been extracted from the accelerator and channeled to the treatment rooms are usually small in diameter compared to the target volumes. Many different methods have been devised to spread out the beams in order to cover the entire target volume with a uniform dose. When using the double-scattering beam delivery method, the entire target volume is irradiated simultaneously; whereas, in the other beam delivery methods, such as the wobbler system or the raster scanning system, a relatively small beam spot is moved around to cover the entire target volume with a uniform dose and only a part of the target volume is irradiated at a time. The latter methods are therefore called dynamic beam delivery methods, and the double scattering method is called a passive beam delivery method. In this note, the dose uniformities achievable using the dynamic beam delivery systems are analyzed, and the requirements placed on the systems specifications are discussed

  4. Design tools for complex dynamic security systems.

    Energy Technology Data Exchange (ETDEWEB)

    Byrne, Raymond Harry; Rigdon, James Brian; Rohrer, Brandon Robinson; Laguna, Glenn A.; Robinett, Rush D. III (.; ); Groom, Kenneth Neal; Wilson, David Gerald; Bickerstaff, Robert J.; Harrington, John J.

    2007-01-01

    The development of tools for complex dynamic security systems is not a straight forward engineering task but, rather, a scientific task where discovery of new scientific principles and math is necessary. For years, scientists have observed complex behavior but have had difficulty understanding it. Prominent examples include: insect colony organization, the stock market, molecular interactions, fractals, and emergent behavior. Engineering such systems will be an even greater challenge. This report explores four tools for engineered complex dynamic security systems: Partially Observable Markov Decision Process, Percolation Theory, Graph Theory, and Exergy/Entropy Theory. Additionally, enabling hardware technology for next generation security systems are described: a 100 node wireless sensor network, unmanned ground vehicle and unmanned aerial vehicle.

  5. Classical and quantum discrete dynamical systems

    Science.gov (United States)

    Kornyak, V. V.

    2013-01-01

    We study deterministic and quantum dynamics from a constructive "finite" point of view, since the introduction of the continuum or other actual infinities in physics poses severe conceptual and technical difficulties, and while all of these concepts are not really needed in physics, which is in fact an empirical science. Particular attention is paid to the symmetry properties of discrete systems. For a consistent description of the symmetries of dynamical systems at different time instants and the symmetries of various parts of such systems, we introduce discrete analogs of gauge connections. These gauge structures are particularly important to describe the quantum behavior. The symmetries govern the fundamental properties of the behavior of dynamical systems. In particular, we can show that the moving soliton-like structures are inevitable in a deterministic (classical) dynamical system, whose symmetry group breaks the set of states into a finite number of orbits of the group. We demonstrate that the quantum behavior is a natural consequence of symmetries of dynamical systems. This behavior is a result of the fundamental inability to trace the identity of indistinguish-able objects during their evolution. Information is only available on invariant statements and values related with such objects. Using general mathematical arguments, any quantum dynamics can be shown to reduce to a sequence of permutations. The quantum interferences occur in the invariant subspaces of permutation representations of the symmetry groups of dynamical systems. The observables can be expressed in terms of permutation invariants. We also show that in order to describe quantum phenomena it is sufficient to use cyclotomic fields—the minimal extensions of natural numbers suitable for quantum mechanics, instead of a non-constructive number system—the field of complex numbers. The finite groups of symmetries play the central role in this review. In physics there is an additional reason

  6. Coherence and chaos in extended dynamical systems

    International Nuclear Information System (INIS)

    Bishop, A.R.

    1994-01-01

    Coherence, chaos, and pattern formation are characteristic elements of the nonequilibrium statistical mechanics controlling mesoscopic order and disorder in many-degree-of-freedom nonlinear dynamical systems. Competing length scales and/or time scales are the underlying microscopic driving forces for many of these aspects of ''complexity.'' We illustrate the basic concepts with some model examples of classical and quantum, ordered and disordered, nonlinear systems

  7. Integrability and nonintegrability of dynamical systems

    CERN Document Server

    Goriely, Alain

    2001-01-01

    This invaluable book examines qualitative and quantitative methods for nonlinear differential equations, as well as integrability and nonintegrability theory. Starting from the idea of a constant of motion for simple systems of differential equations, it investigates the essence of integrability, its geometrical relevance and dynamical consequences. Integrability theory is approached from different perspectives, first in terms of differential algebra, then in terms of complex time singularities and finally from the viewpoint of phase geometry (for both Hamiltonian and non-Hamiltonian systems).

  8. Automated design of complex dynamic systems.

    Directory of Open Access Journals (Sweden)

    Michiel Hermans

    Full Text Available Several fields of study are concerned with uniting the concept of computation with that of the design of physical systems. For example, a recent trend in robotics is to design robots in such a way that they require a minimal control effort. Another example is found in the domain of photonics, where recent efforts try to benefit directly from the complex nonlinear dynamics to achieve more efficient signal processing. The underlying goal of these and similar research efforts is to internalize a large part of the necessary computations within the physical system itself by exploiting its inherent non-linear dynamics. This, however, often requires the optimization of large numbers of system parameters, related to both the system's structure as well as its material properties. In addition, many of these parameters are subject to fabrication variability or to variations through time. In this paper we apply a machine learning algorithm to optimize physical dynamic systems. We show that such algorithms, which are normally applied on abstract computational entities, can be extended to the field of differential equations and used to optimize an associated set of parameters which determine their behavior. We show that machine learning training methodologies are highly useful in designing robust systems, and we provide a set of both simple and complex examples using models of physical dynamical systems. Interestingly, the derived optimization method is intimately related to direct collocation a method known in the field of optimal control. Our work suggests that the application domains of both machine learning and optimal control have a largely unexplored overlapping area which envelopes a novel design methodology of smart and highly complex physical systems.

  9. Some problems of dynamical systems on three dimensional manifolds

    International Nuclear Information System (INIS)

    Dong Zhenxie.

    1985-08-01

    It is important to study the dynamical systems on 3-dimensional manifolds, its importance is showing up in its close relation with our life. Because of the complication of topological structure of Dynamical systems on 3-dimensional manifolds, generally speaking, the search for 3-dynamical systems is not easier than 2-dynamical systems. This paper is a summary of the partial result of dynamical systems on 3-dimensional manifolds. (author)

  10. Setting up a surveillance system for sexually transmitted diseases in the general population with prospective data collection from private-practice and public-practice doctors in Hong Kong

    Directory of Open Access Journals (Sweden)

    Tsui Hi

    2011-04-01

    Full Text Available Abstract Background Existing surveillance systems for sexually transmitted diseases (STD and reproductive tract infections (RTI are important but often ineffective, as they tend to omit cases diagnosed by private-practice doctors Methods During a 15-day study period, 277 private-practice doctors and all public-practice doctors of all the eight local Social Hygiene Clinics (SHC in Hong Kong filled out daily a standard log-form, recording the number of patients diagnosed with particular types of STD/RTI. Projections for all local private-practice and public-practice doctors were made by the stratification method. Results Data showed that 0.75% of private patients and 40.92% of public patients presented the listed STD/RTI syndromes. It is projected that 12,504 adults were diagnosed with such syndromes by all local private-practice (10,204 or public-practice doctors (2,300; 0.22% (male: 0.26%; female: 0.18% of the local adult population would fall into this category. The ratio of STD/RTI cases, diagnosed by private-practice versus public-practice doctors, was 4:1. Of the participating private-practice doctors, 96% found the process easy to administer and 75% believed that it was feasible for such a STD/RTI surveillance system to be implemented annually. Conclusions Surveillance of STD/RTI based only on data obtained from the public health system is inadequate. Data obtained from public-practice and private-practice doctors are very different and the majority of the patients presented their STD/RTI syndromes to private-practice doctors. The proposed, improved surveillance system is feasible and has the strengths of involving both private-practice and public-practice medical practitioners and being well accepted by private-practice doctors.

  11. Talking to Your Doctor

    Medline Plus

    Full Text Available ... to Your Doctor , National Eye Institute (NEI) Español Aging Planning Your Doctor Visit , NIHSeniorHealth.gov Videos: Talking ... A Guide for Older People , National Institute on Aging (NIA) Talking With Your Doctor Presentation Toolkit , National ...

  12. Nonlinear dynamical system approaches towards neural prosthesis

    International Nuclear Information System (INIS)

    Torikai, Hiroyuki; Hashimoto, Sho

    2011-01-01

    An asynchronous discrete-state spiking neurons is a wired system of shift registers that can mimic nonlinear dynamics of an ODE-based neuron model. The control parameter of the neuron is the wiring pattern among the registers and thus they are suitable for on-chip learning. In this paper an asynchronous discrete-state spiking neuron is introduced and its typical nonlinear phenomena are demonstrated. Also, a learning algorithm for a set of neurons is presented and it is demonstrated that the algorithm enables the set of neurons to reconstruct nonlinear dynamics of another set of neurons with unknown parameter values. The learning function is validated by FPGA experiments.

  13. Complex Dynamical System for Toda Lattice

    Science.gov (United States)

    Konno, Kimiaki

    1988-11-01

    Extending an independent variable into complex and introducing an auxiliary function, we investigate nonlinear interactions between solitons for the Toda lattice by observing behavior of zeros of the function. The Newton’s method calculating them is identified with a complex dynamical system. We present numerical results of the Fatou set on the dynamics. According to motion of solitons, the set changes surprisingly. Since soliton solutions include the exponential function, the Fatou set is different from that of the polynomial and the rational functions.

  14. Scalable Molecular Dynamics for Large Biomolecular Systems

    Directory of Open Access Journals (Sweden)

    Robert K. Brunner

    2000-01-01

    Full Text Available We present an optimized parallelization scheme for molecular dynamics simulations of large biomolecular systems, implemented in the production-quality molecular dynamics program NAMD. With an object-based hybrid force and spatial decomposition scheme, and an aggressive measurement-based predictive load balancing framework, we have attained speeds and speedups that are much higher than any reported in literature so far. The paper first summarizes the broad methodology we are pursuing, and the basic parallelization scheme we used. It then describes the optimizations that were instrumental in increasing performance, and presents performance results on benchmark simulations.

  15. Structural dynamics of electronic and photonic systems

    CERN Document Server

    Suhir, Ephraim; Steinberg, David S

    2011-01-01

    The proposed book will offer comprehensive and versatile methodologies and recommendations on how to determine dynamic characteristics of typical micro- and opto-electronic structural elements (printed circuit boards, solder joints, heavy devices, etc.) and how to design a viable and reliable structure that would be able to withstand high-level dynamic loading. Particular attention will be given to portable devices and systems designed for operation in harsh environments (such as automotive, aerospace, military, etc.)  In-depth discussion from a mechanical engineer's viewpoint will be conducte

  16. On sequential dynamical systems and simulation

    Energy Technology Data Exchange (ETDEWEB)

    Barrett, C.L.; Mortveit, H.S.; Reidys, C.M.

    1999-06-01

    The generic structure of computer simulations motivates a new class of discrete dynamical systems that captures this structure in a mathematically precise way. This class of systems consists of (1) a loopfree graph {Upsilon} with vertex set {l_brace}1,2,{hor_ellipsis},n{r_brace} where each vertex has a binary state, (2) a vertex labeled set of functions (F{sub i,{Upsilon}}:F{sub 2}{sup n} {r_arrow} F{sub 2}{sup n}){sub i} and (3) a permutation {pi} {element_of} S{sub n}. The function F{sub i,{Upsilon}} updates the state of vertex i as a function of the states of vertex i and its {Upsilon}-neighbors and leaves the states of all other vertices fixed. The permutation {pi} represents the update ordering, i.e., the order in which the functions F{sub i,{Upsilon}} are applied. By composing the functions F{sub i,{Upsilon}} in the order given by {pi} one obtains the dynamical system (equation given in paper) which the authors refer to as a sequential dynamical system, or SDS for short. The authors will present bounds for the number of functionally different systems and for the number of nonisomorphic digraphs {Gamma}[F{sub {Upsilon}},{pi}] that can be obtained by varying the update order and applications of these to specific graphs and graph classes. This will be done using both combinatorial/algebraic techniques and probabilistic techniques. Finally the authors give results on dynamical system properties for some special systems.

  17. Dynamical systems with applications using Maple

    CERN Document Server

    Lynch, Stephen

    2001-01-01

    "The text treats a remarkable spectrum of topics and has a little for everyone. It can serve as an introduction to many of the topics of dynamical systems, and will help even the most jaded reader, such as this reviewer, enjoy some of the interactive aspects of studying dynamics using Maple." —UK Nonlinear News (Review of First Edition) "The book will be useful for all kinds of dynamical systems courses…. [It] shows the power of using a computer algebra program to study dynamical systems, and, by giving so many worked examples, provides ample opportunity for experiments. … [It] is well written and a pleasure to read, which is helped by its attention to historical background." —Mathematical Reviews (Review of First Edition) Since the first edition of this book was published in 2001, Maple™ has evolved from Maple V into Maple 13. Accordingly, this new edition has been thoroughly updated and expanded to include more applications, examples, and exercises, all with solutions; two new chapters on neural n...

  18. Geometric phases in discrete dynamical systems

    Energy Technology Data Exchange (ETDEWEB)

    Cartwright, Julyan H.E., E-mail: julyan.cartwright@csic.es [Instituto Andaluz de Ciencias de la Tierra, CSIC–Universidad de Granada, E-18100 Armilla, Granada (Spain); Instituto Carlos I de Física Teórica y Computacional, Universidad de Granada, E-18071 Granada (Spain); Piro, Nicolas, E-mail: nicolas.piro@epfl.ch [École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne (Switzerland); Piro, Oreste, E-mail: piro@imedea.uib-csic.es [Departamento de Física, Universitat de les Illes Balears, E-07122 Palma de Mallorca (Spain); Tuval, Idan, E-mail: ituval@imedea.uib-csic.es [Mediterranean Institute for Advanced Studies, CSIC–Universitat de les Illes Balears, E-07190 Mallorca (Spain)

    2016-10-14

    In order to study the behaviour of discrete dynamical systems under adiabatic cyclic variations of their parameters, we consider discrete versions of adiabatically-rotated rotators. Parallelling the studies in continuous systems, we generalize the concept of geometric phase to discrete dynamics and investigate its presence in these rotators. For the rotated sine circle map, we demonstrate an analytical relationship between the geometric phase and the rotation number of the system. For the discrete version of the rotated rotator considered by Berry, the rotated standard map, we further explore this connection as well as the role of the geometric phase at the onset of chaos. Further into the chaotic regime, we show that the geometric phase is also related to the diffusive behaviour of the dynamical variables and the Lyapunov exponent. - Highlights: • We extend the concept of geometric phase to maps. • For the rotated sine circle map, we demonstrate an analytical relationship between the geometric phase and the rotation number. • For the rotated standard map, we explore the role of the geometric phase at the onset of chaos. • We show that the geometric phase is related to the diffusive behaviour of the dynamical variables and the Lyapunov exponent.

  19. Geometry and dynamics of integrable systems

    CERN Document Server

    Matveev, Vladimir

    2016-01-01

    Based on lectures given at an advanced course on integrable systems at the Centre de Recerca Matemàtica in Barcelona, these lecture notes address three major aspects of integrable systems: obstructions to integrability from differential Galois theory; the description of singularities of integrable systems on the basis of their relation to bi-Hamiltonian systems; and the generalization of integrable systems to the non-Hamiltonian settings. All three sections were written by top experts in their respective fields. Native to actual problem-solving challenges in mechanics, the topic of integrable systems is currently at the crossroads of several disciplines in pure and applied mathematics, and also has important interactions with physics. The study of integrable systems also actively employs methods from differential geometry. Moreover, it is extremely important in symplectic geometry and Hamiltonian dynamics, and has strong correlations with mathematical physics, Lie theory and algebraic geometry (including mir...

  20. Dynamical systems on networks a tutorial

    CERN Document Server

    Porter, Mason A

    2016-01-01

    This volume is a tutorial for the study of dynamical systems on networks. It discusses both methodology and models, including spreading models for social and biological contagions. The authors focus especially on “simple” situations that are analytically tractable, because they are insightful and provide useful springboards for the study of more complicated scenarios. This tutorial, which also includes key pointers to the literature, should be helpful for junior and senior undergraduate students, graduate students, and researchers from mathematics, physics, and engineering who seek to study dynamical systems on networks but who may not have prior experience with graph theory or networks. Mason A. Porter is Professor of Nonlinear and Complex Systems at the Oxford Centre for Industrial and Applied Mathematics, Mathematical Institute, University of Oxford, UK. He is also a member of the CABDyN Complexity Centre and a Tutorial Fellow of Somerville College. James P. Gleeson is Professor of Industrial and Appli...

  1. Lunar dynamics and observational coordinate systems

    Science.gov (United States)

    Mulholland, J. D.

    1973-01-01

    The state of the art in lunar dynamics studies is summarized by a partial review of papers presented at a recent COSPAR meeting. The following general conclusions are made from the papers: (1) a comprehensive system of fundamental lunar craters is now feasible. Its coordinates can be determined by combining spacecraft, laser, and radar data. The quality of this system is well in par with those of systems based on earth-based observations. (2) Progress toward very high-precision ephemeris measurements has been very impressive, with fitting errors reduced to a few meters. Physical libration modeling techniques, a major obstacle to further improvement, are in the process of refinement. The lunar figure and planetary attraction were found to influence librations. (3) A combination of new techniques and revolutionized old techniques has a potential for achieving a still higher precision in lunar dynamics studies.

  2. Epidemic Dynamics in Open Quantum Spin Systems

    Science.gov (United States)

    Pérez-Espigares, Carlos; Marcuzzi, Matteo; Gutiérrez, Ricardo; Lesanovsky, Igor

    2017-10-01

    We explore the nonequilibrium evolution and stationary states of an open many-body system that displays epidemic spreading dynamics in a classical and a quantum regime. Our study is motivated by recent experiments conducted in strongly interacting gases of highly excited Rydberg atoms where the facilitated excitation of Rydberg states competes with radiative decay. These systems approximately implement open quantum versions of models for population dynamics or disease spreading where species can be in a healthy, infected or immune state. We show that in a two-dimensional lattice, depending on the dominance of either classical or quantum effects, the system may display a different kind of nonequilibrium phase transition. We moreover discuss the observability of our findings in laser driven Rydberg gases with particular focus on the role of long-range interactions.

  3. Dynamic graph system for a semantic database

    Science.gov (United States)

    Mizell, David

    2015-01-27

    A method and system in a computer system for dynamically providing a graphical representation of a data store of entries via a matrix interface is disclosed. A dynamic graph system provides a matrix interface that exposes to an application program a graphical representation of data stored in a data store such as a semantic database storing triples. To the application program, the matrix interface represents the graph as a sparse adjacency matrix that is stored in compressed form. Each entry of the data store is considered to represent a link between nodes of the graph. Each entry has a first field and a second field identifying the nodes connected by the link and a third field with a value for the link that connects the identified nodes. The first, second, and third fields represent the rows, column, and elements of the adjacency matrix.

  4. Nonlinear PDEs a dynamical systems approach

    CERN Document Server

    Schneider, Guido

    2017-01-01

    This is an introductory textbook about nonlinear dynamics of PDEs, with a focus on problems over unbounded domains and modulation equations. The presentation is example-oriented, and new mathematical tools are developed step by step, giving insight into some important classes of nonlinear PDEs and nonlinear dynamics phenomena which may occur in PDEs. The book consists of four parts. Parts I and II are introductions to finite- and infinite-dimensional dynamics defined by ODEs and by PDEs over bounded domains, respectively, including the basics of bifurcation and attractor theory. Part III introduces PDEs on the real line, including the Korteweg-de Vries equation, the Nonlinear Schrödinger equation and the Ginzburg-Landau equation. These examples often occur as simplest possible models, namely as amplitude or modulation equations, for some real world phenomena such as nonlinear waves and pattern formation. Part IV explores in more detail the connections between such complicated physical systems and the reduced...

  5. Controlling Chemistry in Dynamic Nanoscale Systems

    DEFF Research Database (Denmark)

    Jesorka, Aldo; Lizana, Ludvig; Konkoli, Zoran

    2011-01-01

    of the concept. Controlled release of chol-DNA molecules from SU-8 surfaces gives the possibility to dynamically change surface and/or solution properties in micro and nanoreactor applications, opening access to stable 2D chemistry on surface-based devices with potential for easy interfacing with conventional......Spatial organization and shape dynamics are inherent properties of biological cells and cell interiors. There are strong indications that these features are important for the in vivo control of reaction parameters in biochemical transformations. Nanofluidic model devices founded on surfactant....... The important interplay between chemical reactions and geometry has been conceptualized within a theoretical framework for ultra-small volumes and tested on a number of experimental systems, opening pathways to more complex, dynamically compartmentalized ultra-small volume reactors, or artificial model cells...

  6. The dynamical crossover in attractive colloidal systems

    International Nuclear Information System (INIS)

    Mallamace, Francesco; Corsaro, Carmelo; Stanley, H. Eugene; Mallamace, Domenico; Chen, Sow-Hsin

    2013-01-01

    We study the dynamical arrest in an adhesive hard-sphere colloidal system. We examine a micellar suspension of the Pluronic-L64 surfactant in the temperature (T) and volume fraction (ϕ) phase diagram. According to mode-coupling theory (MCT), this system is characterized by a cusp-like singularity and two glassy phases: an attractive glass (AG) phase and a repulsive glass (RG) phase. The T − ϕ phase diagram of this system as confirmed by a previous series of scattering data also exhibits a Percolation Threshold (PT) line, a reentrant behavior (AG-liquid-RG), and a glass-to-glass transition. The AG phase can be generated out of the liquid phase by using T and ϕ as control parameters. We utilize viscosity and nuclear magnetic resonance (NMR) techniques. NMR data confirm all the characteristic properties of the colloidal system phase diagram and give evidence of the onset of a fractal-like percolating structure at a precise threshold. The MCT scaling laws used to study the shear viscosity as a function of ϕ and T show in both cases a fragile-to-strong liquid glass-forming dynamic crossover (FSC) located near the percolation threshold where the clustering process is fully developed. These results suggest a larger thermodynamic generality for this phenomenon, which is usually studied only as a function of the temperature. We also find that the critical values of the control parameters, coincident with the PT line, define the locus of the FSC. In the region between the FSC and the glass transition lines the system dynamics are dominated by clustering effects. We thus demonstrate that it is possible, using the conceptual framework provided by extended mode-coupling theory, to describe the way a system approaches dynamic arrest, taking into account both cage and hopping effects

  7. The dynamical crossover in attractive colloidal systems

    Energy Technology Data Exchange (ETDEWEB)

    Mallamace, Francesco [Dipartimento di Fisica e Scienze della Terra, Università di Messina and CNISM, I-98168 Messina (Italy); Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Corsaro, Carmelo [Dipartimento di Fisica e Scienze della Terra, Università di Messina and CNISM, I-98168 Messina (Italy); Stanley, H. Eugene [Center for Polymer Studies and Department of Physics, Boston University, Boston, Massachusetts 02215 (United States); Mallamace, Domenico [Dipartimento di Scienze dell’Ambiente, della Sicurezza, del Territorio, degli Alimenti e della Salute, Università di Messina, I-98166 Messina (Italy); Chen, Sow-Hsin [Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2013-12-07

    We study the dynamical arrest in an adhesive hard-sphere colloidal system. We examine a micellar suspension of the Pluronic-L64 surfactant in the temperature (T) and volume fraction (ϕ) phase diagram. According to mode-coupling theory (MCT), this system is characterized by a cusp-like singularity and two glassy phases: an attractive glass (AG) phase and a repulsive glass (RG) phase. The T − ϕ phase diagram of this system as confirmed by a previous series of scattering data also exhibits a Percolation Threshold (PT) line, a reentrant behavior (AG-liquid-RG), and a glass-to-glass transition. The AG phase can be generated out of the liquid phase by using T and ϕ as control parameters. We utilize viscosity and nuclear magnetic resonance (NMR) techniques. NMR data confirm all the characteristic properties of the colloidal system phase diagram and give evidence of the onset of a fractal-like percolating structure at a precise threshold. The MCT scaling laws used to study the shear viscosity as a function of ϕ and T show in both cases a fragile-to-strong liquid glass-forming dynamic crossover (FSC) located near the percolation threshold where the clustering process is fully developed. These results suggest a larger thermodynamic generality for this phenomenon, which is usually studied only as a function of the temperature. We also find that the critical values of the control parameters, coincident with the PT line, define the locus of the FSC. In the region between the FSC and the glass transition lines the system dynamics are dominated by clustering effects. We thus demonstrate that it is possible, using the conceptual framework provided by extended mode-coupling theory, to describe the way a system approaches dynamic arrest, taking into account both cage and hopping effects.

  8. Control theory of digitally networked dynamic systems

    CERN Document Server

    Lunze, Jan

    2013-01-01

    The book gives an introduction to networked control systems and describes new modeling paradigms, analysis methods for event-driven, digitally networked systems, and design methods for distributed estimation and control. Networked model predictive control is developed as a means to tolerate time delays and packet loss brought about by the communication network. In event-based control the traditional periodic sampling is replaced by state-dependent triggering schemes. Novel methods for multi-agent systems ensure complete or clustered synchrony of agents with identical or with individual dynamic

  9. Classical dynamics of particles and systems

    CERN Document Server

    Marion, Jerry B

    1965-01-01

    Classical Dynamics of Particles and Systems presents a modern and reasonably complete account of the classical mechanics of particles, systems of particles, and rigid bodies for physics students at the advanced undergraduate level. The book aims to present a modern treatment of classical mechanical systems in such a way that the transition to the quantum theory of physics can be made with the least possible difficulty; to acquaint the student with new mathematical techniques and provide sufficient practice in solving problems; and to impart to the student some degree of sophistication in handl

  10. Modelling and parameter estimation of dynamic systems

    CERN Document Server

    Raol, JR; Singh, J

    2004-01-01

    Parameter estimation is the process of using observations from a system to develop mathematical models that adequately represent the system dynamics. The assumed model consists of a finite set of parameters, the values of which are calculated using estimation techniques. Most of the techniques that exist are based on least-square minimization of error between the model response and actual system response. However, with the proliferation of high speed digital computers, elegant and innovative techniques like filter error method, H-infinity and Artificial Neural Networks are finding more and mor

  11. Doctors in Balzac's work.

    Science.gov (United States)

    Moulin, Thierry

    2013-01-01

    Balzac wrote his novels during a time of great literary and scientific change. Romanticism gave way to the school of realism, of which Balzac could be considered the founder. It was via realism, where both the positive and negative aspects of life were depicted, that doctors naturally gained a much more active role in novels. In conjunction with this was the development of science and medicine, which fascinated Balzac, also leading to the significant and prevalent role of doctors in his works. His fascination with the sciences led to him to gain many acquaintances and much knowledge in the medical domain, especially in neuropsychiatry and physiology. His fictional doctors, such as Desplein and Bianchon, thus demonstrate considerable knowledge of pathology, physiology, and neuropsychiatry. The doctors in Balzac's novels can be grouped into four categories: provincial doctors, Parisian doctors, country doctors, and military doctors. They were most often fictitious representations of real individuals (e.g. Guillaume Dupuytren), and often symbolize schools of thought which were in vogue at the time. In addition to the accurate scientific depiction of doctors, it must be noted that his doctors not only played an active role in clinically assessing their patients, but also had a sociological role in assessing society; it is through his doctors that Balzac gave his opinion of the world in which he lived. Copyright © 2013 S. Karger AG, Basel.

  12. Q-deformed systems and constrained dynamics

    International Nuclear Information System (INIS)

    Shabanov, S.V.

    1993-01-01

    It is shown that quantum theories of the q-deformed harmonic oscillator and one-dimensional free q-particle (a free particle on the 'quantum' line) can be obtained by the canonical quantization of classical Hamiltonian systems with commutative phase-space variables and a non-trivial symplectic structure. In the framework of this approach, classical dynamics of a particle on the q-line coincides with the one of a free particle with friction. It is argued that q-deformed systems can be treated as ordinary mechanical systems with the second-class constraints. In particular, second-class constrained systems corresponding to the q-oscillator and q-particle are given. A possibility of formulating q-deformed systems via gauge theories (first-class constrained systems) is briefly discussed. (orig.)

  13. Using system dynamics simulation for assessment of hydropower system safety

    Science.gov (United States)

    King, L. M.; Simonovic, S. P.; Hartford, D. N. D.

    2017-08-01

    Hydropower infrastructure systems are complex, high consequence structures which must be operated safely to avoid catastrophic impacts to human life, the environment, and the economy. Dam safety practitioners must have an in-depth understanding of how these systems function under various operating conditions in order to ensure the appropriate measures are taken to reduce system vulnerability. Simulation of system operating conditions allows modelers to investigate system performance from the beginning of an undesirable event to full system recovery. System dynamics simulation facilitates the modeling of dynamic interactions among complex arrangements of system components, providing outputs of system performance that can be used to quantify safety. This paper presents the framework for a modeling approach that can be used to simulate a range of potential operating conditions for a hydropower infrastructure system. Details of the generic hydropower infrastructure system simulation model are provided. A case study is used to evaluate system outcomes in response to a particular earthquake scenario, with two system safety performance measures shown. Results indicate that the simulation model is able to estimate potential measures of system safety which relate to flow conveyance and flow retention. A comparison of operational and upgrade strategies is shown to demonstrate the utility of the model for comparing various operational response strategies, capital upgrade alternatives, and maintenance regimes. Results show that seismic upgrades to the spillway gates provide the largest improvement in system performance for the system and scenario of interest.

  14. Network Physiology: How Organ Systems Dynamically Interact.

    Science.gov (United States)

    Bartsch, Ronny P; Liu, Kang K L; Bashan, Amir; Ivanov, Plamen Ch

    2015-01-01

    We systematically study how diverse physiologic systems in the human organism dynamically interact and collectively behave to produce distinct physiologic states and functions. This is a fundamental question in the new interdisciplinary field of Network Physiology, and has not been previously explored. Introducing the novel concept of Time Delay Stability (TDS), we develop a computational approach to identify and quantify networks of physiologic interactions from long-term continuous, multi-channel physiological recordings. We also develop a physiologically-motivated visualization framework to map networks of dynamical organ interactions to graphical objects encoded with information about the coupling strength of network links quantified using the TDS measure. Applying a system-wide integrative approach, we identify distinct patterns in the network structure of organ interactions, as well as the frequency bands through which these interactions are mediated. We establish first maps representing physiologic organ network interactions and discover basic rules underlying the complex hierarchical reorganization in physiologic networks with transitions across physiologic states. Our findings demonstrate a direct association between network topology and physiologic function, and provide new insights into understanding how health and distinct physiologic states emerge from networked interactions among nonlinear multi-component complex systems. The presented here investigations are initial steps in building a first atlas of dynamic interactions among organ systems.

  15. International Conference on Dynamical Systems : Theory and Applications

    CERN Document Server

    2016-01-01

    The book is a collection of contributions devoted to analytical, numerical and experimental techniques of dynamical systems, presented at the international conference "Dynamical Systems: Theory and Applications," held in Lódz, Poland on December 7-10, 2015. The studies give deep insight into new perspectives in analysis, simulation, and optimization of dynamical systems, emphasizing directions for future research. Broadly outlined topics covered include: bifurcation and chaos in dynamical systems, asymptotic methods in nonlinear dynamics, dynamics in life sciences and bioengineering, original numerical methods of vibration analysis, control in dynamical systems, stability of dynamical systems, vibrations of lumped and continuous sytems, non-smooth systems, engineering systems and differential equations, mathematical approaches to dynamical systems, and mechatronics.

  16. International Conference on Dynamical Systems : Theory and Applications

    CERN Document Server

    2016-01-01

    The book is the second volume of a collection of contributions devoted to analytical, numerical and experimental techniques of dynamical systems, presented at the international conference "Dynamical Systems: Theory and Applications," held in Lódz, Poland on December 7-10, 2015. The studies give deep insight into new perspectives in analysis, simulation, and optimization of dynamical systems, emphasizing directions for future research. Broadly outlined topics covered include: bifurcation and chaos in dynamical systems, asymptotic methods in nonlinear dynamics, dynamics in life sciences and bioengineering, original numerical methods of vibration analysis, control in dynamical systems, stability of dynamical systems, vibrations of lumped and continuous sytems, non-smooth systems, engineering systems and differential equations, mathematical approaches to dynamical systems, and mechatronics.

  17. Emulation tool of dynamic systems via internet

    Directory of Open Access Journals (Sweden)

    Daniel Ruiz Olaya

    2015-11-01

    Full Text Available The experimentation laboratories for the studies of control system courses can become expensive, either in its acquisition, operation or maintenance. An alternative resource have been the remote laboratories. However, not always is possible to get complex systems. A solution to this matter are the remote emulation laboratories. In this paper describes the development of a Web application for the emulation of dynamic systems using a free-distribution software tool of rapid control prototyping based on Linux/RTAI. This application is focused especially for the experimentation with dynamic systems that are not available easily in a laboratory where the model have been configured by the user. The design of the front-end and the back-end are presented. The latency times of the real-time operating system and the ability of the system to reproduce similar signals to a real system from an emulated model were verified. An example, to test the functionality of the application the model of an evaporator was used. One of the advantages of the application is the work methodology which is based on the development of blocks in Scicos. This allows the user to reuse those parameters and the code that was implemented to build a block on the Scicos toolbox with the Linux/RTAI/ScicosLab environment. Moreover, only a web-browser and the Java Virtual Machine are required.

  18. Women who doctor shop for prescription drugs.

    Science.gov (United States)

    Worley, Julie; Thomas, Sandra P

    2014-04-01

    Doctor shopping is a term used to describe a form of diversion of prescription drugs when patients visit numerous prescribers to obtain controlled drugs for illicit use. Gender differences exist in regard to prescription drug abuse and methods of diversion. The purpose of this phenomenological study guided by the existential philosophy of Merleau-Ponty was to understand the lived experience of female doctor shoppers. Interviews were conducted with 14 women, which were recorded, transcribed, and analyzed. Included in the findings are figural aspects of the participants' experience of doctor shopping related to the existential grounds of world, time, body, and others. Four themes emerged from the data: (a) feeding the addiction, (b) networking with addicts, (c) playing the system, and (d) baiting the doctors. The findings suggest several measures that nurses can take to reduce the incidence of doctor shopping and to provide better care for female doctor shoppers.

  19. DYNAMIC MAGNIFICATION OF BIOMECHANICAL SYSTEM MOTION

    Directory of Open Access Journals (Sweden)

    A. E. Pokatilov

    2017-01-01

    Full Text Available Methods for estimation of dynamic magnification pertaining to motion in biomechanics have been developed and approbаted in the paper. It has been ascertained that widely-used characteristics for evaluation of motion influence on mechanisms and machinery such as a dynamic coefficient and acceleration capacity factor become irrelevant while investigating human locomotion under elastic support conditions. The reason is an impossibility to compare human motion in case when there is a contact with elastic and rigid supports because while changing rigidity of the support exercise performing technique is also changing. In this case the technique still depends on a current state of a specific sportsman. Such situation is observed in sports gymnastics. Structure of kinematic and dynamic models for human motion has been investigated in the paper. It has been established that properties of an elastic support are reflected in models within two aspects: in an explicit form, when models have parameters of dynamic deformation for a gymnastic apparatus, and in an implicit form, when we have numerically changed parameters of human motion. The first part can be evaluated quantitatively while making comparison with calculations made in accordance with complete models. For this reason notions of selected and complete models have been introduced in the paper. It has been proposed to specify models for support and models of biomechanical system that represent models pertaining only to human locomotor system. It has been revealed that the selected models of support in kinematics and dynamics have structural difference. Kinematics specifies only parameters of elastic support deformation and dynamics specifies support parameters in an explicit form and additionally in models of human motion in an explicit form as well. Quantitative estimation of a dynamic motion magnification in kinematics and dynamics models has been given while using computing experiment for grand

  20. Joint development of evidence-based medical record by doctors and patients through integrated Chinese and Western medicine on digestive system diseases.

    Science.gov (United States)

    Li, Bo; Gao, Hong-yang; Gao, Rui; Zhao, Ying-pan; Li, Qing-na; Zhao, Yang; Tang, Xu-dong; Shang, Hong-cai

    2016-02-01

    Building the clinical therapeutic evaluation system by combing the evaluation given by doctors and patients can form a more comprehensive and objective evaluation system. A literature search on the practice of evidence-based evaluation was conducted in key biomedical databases, i.e. PubMed, Excerpt Medica Database, China Biology Medicine disc and China National Knowledge Infrastructure. However, no relevant study on the subjects of interest was identified. Therefore, drawing on the principles of narrative medicine and expert opinion from systems of Chinese medicine and Western medicine, we propose to develop and pilot-test a novel evidence-based medical record format that captures the perspectives of both patients and doctors in a clinical trial. Further, we seek to evaluate a strategic therapeutic approach that integrates the wisdom of Chinese medicine with the scientific basis of Western medicine in the treatment of digestive system disorders. Evaluation of therapeutic efficacy of remedies under the system of Chinese medicine is an imperative ongoing research. The present study intends to identify a novel approach to assess the synergistic benefits achievable from an integrated therapeutic approach combining Chinese and Western system of medicine to treat digestive system disorders.

  1. The dynamic state monitoring of bearings system

    Directory of Open Access Journals (Sweden)

    Marek Krynke

    2015-03-01

    Full Text Available The article discusses the methods of dynamic state monitoring of bearings system. A vibration signal contains important technical information about the machine condition and is currently the most frequently used in diagnostic bearings systems. One of the main ad-vantages of machine condition monitoring is identifying the cause of failure of the bearings and taking preventative measures, otherwise the operation of such a machine will lead to frequent replacement of the bearings. Monitoring changes in the course of the operation of machin-ery repair strategies allows keeping the conditioned state of dynamic failure conditioned preventive repairs and repairs after-failure time. In addition, the paper also presents the fundamental causes of bearing failure and identifies mechanisms related to the creation of any type of damage.

  2. Dynamically variable spot size laser system

    Science.gov (United States)

    Gradl, Paul R. (Inventor); Hurst, John F. (Inventor); Middleton, James R. (Inventor)

    2012-01-01

    A Dynamically Variable Spot Size (DVSS) laser system for bonding metal components includes an elongated housing containing a light entry aperture coupled to a laser beam transmission cable and a light exit aperture. A plurality of lenses contained within the housing focus a laser beam from the light entry aperture through the light exit aperture. The lenses may be dynamically adjusted to vary the spot size of the laser. A plurality of interoperable safety devices, including a manually depressible interlock switch, an internal proximity sensor, a remotely operated potentiometer, a remotely activated toggle and a power supply interlock, prevent activation of the laser and DVSS laser system if each safety device does not provide a closed circuit. The remotely operated potentiometer also provides continuous variability in laser energy output.

  3. A Type System for Dynamic Web Documents

    DEFF Research Database (Denmark)

    Schwartzbach, Michael Ignatieff; Sandholm, Anders

    2000-01-01

    Many interactive Web services use the CGI interface for communication with clients. They will dynamically create HTML documents that are presented to the client who then resumes the interaction by submitting data through incorporated form fields. This protocol is difficult to statically type......-check if the dynamic documents are created by arbitrary script code using printf-like statements. Previous proposals have suggested using static document templates which trades flexibility for safety. We propose a notion of typed, higher-order templates that simultaneously achieve flexibility and safety. Our type...... system is based on a flow analysis of which we prove soundness. We present an efficient runtime implementation that respects the semantics of only well-typed programs. This work is fully implemented as part of the system for defining interactive Web services....

  4. Dynamical systems with applications using MATLAB

    CERN Document Server

    Lynch, Stephen

    2014-01-01

    This textbook, now in its second edition, provides a broad introduction to both continuous and discrete dynamical systems, the theory of which is motivated by examples from a wide range of disciplines. It emphasizes applications and simulation utilizing MATLAB®, Simulink®, the Image Processing Toolbox™, and the Symbolic Math Toolbox™, including MuPAD. Features new to the second edition include, sections on series solutions of ordinary differential equations, perturbation methods, normal forms, Gröbner bases, and chaos synchronization; chapters on image processing and binary oscillator computing; hundreds of new illustrations, examples, and exercises with solutions; and over eighty up-to-date MATLAB® program files and Simulink model files available online. These files were voted MATLAB® Central Pick of the Week in July 2013.  The hands-on approach of Dynamical Systems with Applications using MATLAB®, Second Edition, has minimal prerequisites, only requiring familiarity with ordinary differential equ...

  5. Introduction to turbulent dynamical systems in complex systems

    CERN Document Server

    Majda, Andrew J

    2016-01-01

    This volume is a research expository article on the applied mathematics of turbulent dynamical systems through the paradigm of modern applied mathematics. It involves the blending of rigorous mathematical theory, qualitative and quantitative modeling, and novel numerical procedures driven by the goal of understanding physical phenomena which are of central importance to the field. The contents cover general framework, concrete examples, and instructive qualitative models. Accessible open problems are mentioned throughout. Topics covered include: · Geophysical flows with rotation, topography, deterministic and random forcing · New statistical energy principles for general turbulent dynamical systems, with applications · Linear statistical response theory combined with information theory to cope with model errors · Reduced low order models · Recent mathematical strategies for online data assimilation of turbulent dynamical systems as well as rigorous results for finite ensemble Kalman filters The volume wi...

  6. Trichotomy for dynamical systems in Banach spaces.

    Science.gov (United States)

    Stoica, Codruţa

    2013-01-01

    We construct a framework for the study of dynamical systems that describe phenomena from physics and engineering in infinite dimensions and whose state evolution is set out by skew-evolution semiflows. Therefore, we introduce the concept of ω-trichotomy. Characterizations in a uniform setting are proved, using techniques from the domain of nonautonomous evolution equations with unbounded coefficients, and connections with the classic notion of trichotomy are given. The statements are sustained by several examples.

  7. Nested observer for linear hybrid dynamical systems

    International Nuclear Information System (INIS)

    Abdi, M.; Bensalah, H.; Cherki, B.

    2009-01-01

    The synthesis of observers for linear hybrid dynamical systems ''HDS,'' is significant from the point of view of the applications (control, diagnoses...); it is still, largely open. We proposed a new approach inspired from a new method of identification, where we could obtain better results with respect to discrimination between the discrete states in conflicts and time necessary to this latter. The results of the suggested technique proved to be satisfactory.

  8. Structure and dynamics of disordered systems

    International Nuclear Information System (INIS)

    Price, D.L.

    1989-01-01

    Neutron scattering has proved to be a powerful tool in the study of glasses and liquids: structures are investigated by neutron diffraction, and dynamics by inelastic neutron scattering. Evidence of current interest in this field is provided by the new instruments for diffraction from amorphous systems being constructed at IPNS, ISIS and the R2-reactor at Studsvik, in addition to existing instruments such as the D4B diffractometer at ILL. 14 refs., 9 figs

  9. High Performance Interactive System Dynamics Visualization

    Energy Technology Data Exchange (ETDEWEB)

    Bush, Brian W [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Brunhart-Lupo, Nicholas J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Gruchalla, Kenny M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Duckworth, Jonathan C [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-14

    This brochure describes a system dynamics simulation (SD) framework that supports an end-to-end analysis workflow that is optimized for deployment on ESIF facilities(Peregrine and the Insight Center). It includes (I) parallel and distributed simulation of SD models, (ii) real-time 3D visualization of running simulations, and (iii) comprehensive database-oriented persistence of simulation metadata, inputs, and outputs.

  10. High Performance Interactive System Dynamics Visualization

    Energy Technology Data Exchange (ETDEWEB)

    Bush, Brian W [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Brunhart-Lupo, Nicholas J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Gruchalla, Kenny M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Duckworth, Jonathan C [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-14

    This presentation describes a system dynamics simulation (SD) framework that supports an end-to-end analysis workflow that is optimized for deployment on ESIF facilities(Peregrine and the Insight Center). It includes (I) parallel and distributed simulation of SD models, (ii) real-time 3D visualization of running simulations, and (iii) comprehensive database-oriented persistence of simulation metadata, inputs, and outputs.

  11. Second International Colloquium on Dynamical Systems

    CERN Document Server

    Seade, José; Verjovski, Alberto

    1988-01-01

    The objective of the meeting was to have together leading specialists in the field of Holomorphic Dynamical Systems in order to present their current reseach in the field. The scope was to cover iteration theory of holomorphic mappings (i.e. rational maps), holomorphic differential equations and foliations. Many of the conferences and articles included in the volume contain open problems of current interest. The volume contains only research articles.

  12. Systemic risk: the dynamics of model banking systems.

    Science.gov (United States)

    May, Robert M; Arinaminpathy, Nimalan

    2010-05-06

    The recent banking crises have made it clear that increasingly complex strategies for managing risk in individual banks have not been matched by corresponding attention to overall systemic risks. We explore some simple mathematical caricatures for 'banking ecosystems', with emphasis on the interplay between the characteristics of individual banks (capital reserves in relation to total assets, etc.) and the overall dynamical behaviour of the system. The results are discussed in relation to potential regulations aimed at reducing systemic risk.

  13. Complex and adaptive dynamical systems a primer

    CERN Document Server

    Gros, Claudius

    2013-01-01

    Complex system theory is rapidly developing and gaining importance, providing tools and concepts central to our modern understanding of emergent phenomena. This primer offers an introduction to this area together with detailed coverage of the mathematics involved. All calculations are presented step by step and are straightforward to follow. This new third edition comes with new material, figures and exercises. Network theory, dynamical systems and information theory, the core of modern complex system sciences, are developed in the first three chapters, covering basic concepts and phenomena like small-world networks, bifurcation theory and information entropy. Further chapters use a modular approach to address the most important concepts in complex system sciences, with the emergence and self-organization playing a central role. Prominent examples are self-organized criticality in adaptive systems, life at the edge of chaos, hypercycles and coevolutionary avalanches, synchronization phenomena, absorbing phase...

  14. Dynamic mode decomposition for compressive system identification

    Science.gov (United States)

    Bai, Zhe; Kaiser, Eurika; Proctor, Joshua L.; Kutz, J. Nathan; Brunton, Steven L.

    2017-11-01

    Dynamic mode decomposition has emerged as a leading technique to identify spatiotemporal coherent structures from high-dimensional data. In this work, we integrate and unify two recent innovations that extend DMD to systems with actuation and systems with heavily subsampled measurements. When combined, these methods yield a novel framework for compressive system identification, where it is possible to identify a low-order model from limited input-output data and reconstruct the associated full-state dynamic modes with compressed sensing, providing interpretability of the state of the reduced-order model. When full-state data is available, it is possible to dramatically accelerate downstream computations by first compressing the data. We demonstrate this unified framework on simulated data of fluid flow past a pitching airfoil, investigating the effects of sensor noise, different types of measurements (e.g., point sensors, Gaussian random projections, etc.), compression ratios, and different choices of actuation (e.g., localized, broadband, etc.). This example provides a challenging and realistic test-case for the proposed method, and results indicate that the dominant coherent structures and dynamics are well characterized even with heavily subsampled data.

  15. Doctors and pharmaceutical industry.

    Science.gov (United States)

    Beran, Roy G

    2009-09-01

    The pharmaceutical industry is seen as seducing doctors by providing expensive gifts, subsidising travel and underwriting practice expenses in return for those doctors prescribing products that otherwise they would not use. This paints doctors in a very negative light; suggests doctors are available to the highest bidder; implies doctors do not adequately act as independent agents; and that doctors are driven more by self-interest than by patient needs. Similar practices, in other industries, are accepted as normal business behaviour but it is automatically assumed to be improper if the pharmaceutical industry supports doctors. Should the pharmaceutical industry withdraw educational grants then there would be: fewer scientific meetings; reduced attendance at conferences; limited post graduate education; and a depreciated level of maintenance of professional standards. To suggest that doctors prescribe inappropriately in return for largesse maligns their integrity but where there is no scientific reason to choose between different treatments then there can be little argument against selecting the product manufactured by a company that has invested in the doctor and the question arises as to whether this represents bad medicine? This paper will examine what constitutes non-professional conduct in response to inducements by the pharmaceutical industry. It will review: conflict of interest; relationships between doctors and pharma and the consequences for patients; and the need for critical appraisal before automatically decrying this relationship while accepting that there remain those who do not practice ethical medicine.

  16. Optimization of multi-response dynamic systems integrating multiple ...

    African Journals Online (AJOL)

    Optimization of multi-response dynamic systems integrating multiple regression and Taguchi's dynamic signal-to-noise ratio concept. ... Assuming a linear association exists between the response and signal variables, Taguchi offered a two-stage route for optimizing a dynamic system: maximize the dynamic signal-to noise ...

  17. Dynamical properties of unconventional magnetic systems

    International Nuclear Information System (INIS)

    Helgesen, G.

    1997-05-01

    The Advanced Study Institute addressed the current experimental and theoretical knowledge of the dynamical properties of unconventional magnetic systems including low-dimensional and mesoscopic magnetism, unconventional ground state, quantum magnets and soft matter. The main approach in this Advanced Study Institute was to obtain basic understanding of co-operative phenomena, fluctuations and excitations in the wide range unconventional magnetic systems now being fabricated or envisioned. The report contains abstracts for lectures, invited seminars and posters, together with a list of the 95 participants from 24 countries with e-mail addresses

  18. Testing relativity with solar system dynamics

    Science.gov (United States)

    Hellings, R. W.

    1984-01-01

    A major breakthrough is described in the accuracy of Solar System dynamical tests of relativistic gravity. The breakthrough was achieved by factoring in ranging data from Viking Landers 1 and 2 from the surface of Mars. Other key data sources included optical transit circle observations, lunar laser ranging, planetary radar, and spacecraft (Mariner 9 to Mars and Mariner 10 to Mercury). The Solar System model which is used to fit the data and the process by which such fits are performed are explained and results are discussed. The results are fully consistent with the predictions of General Relativity.

  19. Literature Review on Dynamic Cellular Manufacturing System

    Science.gov (United States)

    Nouri Houshyar, A.; Leman, Z.; Pakzad Moghadam, H.; Ariffin, M. K. A. M.; Ismail, N.; Iranmanesh, H.

    2014-06-01

    In previous decades, manufacturers faced a lot of challenges because of globalization and high competition in markets. These problems arise from shortening product life cycle, rapid variation in demand of products, and also rapid changes in manufcaturing technologies. Nowadays most manufacturing companies expend considerable attention for improving flexibility and responsiveness in order to overcome these kinds of problems and also meet customer's needs. By considering the trend toward the shorter product life cycle, the manufacturing environment is towards manufacturing a wide variety of parts in small batches [1]. One of the major techniques which are applied for improving manufacturing competitiveness is Cellular Manufacturing System (CMS). CMS is type of manufacturing system which tries to combine flexibility of job shop and also productivity of flow shop. In addition, Dynamic cellular manufacturing system which considers different time periods for the manufacturing system becomes an important topic and attracts a lot of attention to itself. Therefore, this paper made attempt to have a brief review on this issue and focused on all published paper on this subject. Although, this topic gains a lot of attention to itself during these years, none of previous researchers focused on reviewing the literature of that which can be helpful and useful for other researchers who intend to do the research on this topic. Therefore, this paper is the first study which has focused and reviewed the literature of dynamic cellular manufacturing system.

  20. Robustness of dynamic systems with parameter uncertainties

    CERN Document Server

    Balemi, S; Truöl, W

    1992-01-01

    Robust Control is one of the fastest growing and promising areas of research today. In many practical systems there exist uncertainties which have to be considered in the analysis and design of control systems. In the last decade methods were developed for dealing with dynamic systems with unstructured uncertainties such as HOO_ and £I-optimal control. For systems with parameter uncertainties, the seminal paper of V. L. Kharitonov has triggered a large amount of very promising research. An international workshop dealing with all aspects of robust control was successfully organized by S. P. Bhattacharyya and L. H. Keel in San Antonio, Texas, USA in March 1991. We organized the second international workshop in this area in Ascona, Switzer­ land in April 1992. However, this second workshop was restricted to robust control of dynamic systems with parameter uncertainties with the objective to concentrate on some aspects of robust control. This book contains a collection of papers presented at the International W...

  1. Introduction to Dynamical Systems and Geometric Mechanics

    Science.gov (United States)

    Maruskin, Jared M.

    2012-01-01

    Introduction to Dynamical Systems and Geometric Mechanics provides a comprehensive tour of two fields that are intimately entwined: dynamical systems is the study of the behavior of physical systems that may be described by a set of nonlinear first-order ordinary differential equations in Euclidean space, whereas geometric mechanics explores similar systems that instead evolve on differentiable manifolds. In the study of geometric mechanics, however, additional geometric structures are often present, since such systems arise from the laws of nature that govern the motions of particles, bodies, and even galaxies. In the first part of the text, we discuss linearization and stability of trajectories and fixed points, invariant manifold theory, periodic orbits, Poincaré maps, Floquet theory, the Poincaré-Bendixson theorem, bifurcations, and chaos. The second part of the text begins with a self-contained chapter on differential geometry that introduces notions of manifolds, mappings, vector fields, the Jacobi-Lie bracket, and differential forms. The final chapters cover Lagrangian and Hamiltonian mechanics from a modern geometric perspective, mechanics on Lie groups, and nonholonomic mechanics via both moving frames and fiber bundle decompositions. The text can be reasonably digested in a single-semester introductory graduate-level course. Each chapter concludes with an application that can serve as a springboard project for further investigation or in-class discussion.

  2. Complex and adaptive dynamical systems a primer

    CERN Document Server

    Gros, Claudius

    2015-01-01

    This primer offers readers an introduction to the central concepts that form our modern understanding of complex and emergent behavior, together with detailed coverage of accompanying mathematical methods. All calculations are presented step by step and are easy to follow. This new fourth edition has been fully reorganized and includes new chapters, figures and exercises. The core aspects of modern complex system sciences are presented in the first chapters, covering network theory, dynamical systems, bifurcation and catastrophe theory, chaos and adaptive processes, together with the principle of self-organization in reaction-diffusion systems and social animals. Modern information theoretical principles are treated in further chapters, together with the concept of self-organized criticality, gene regulation networks, hypercycles and coevolutionary avalanches, synchronization phenomena, absorbing phase transitions and the cognitive system approach to the brain. Technical course prerequisites are the standard ...

  3. Dynamically programmable electronic pill dispenser system.

    Science.gov (United States)

    Boquete, Luciano; Rodriguez-Ascariz, Jose Manuel; Artacho, Irene; Cantos-Frontela, Joaquin; Peixoto, Nathalia

    2010-06-01

    Compliance in medicine dispensation has proven critical for dosage control, diagnosis, and treatment. We have designed, manufactured, and characterized a novel dynamically programmable e-pill dispensing system. Our system is initially programmed remotely through a cell phone. After programming, the system may be reconfigured in order to adapt pill dispensation to new conditions. In this paper we describe the mechanics, electronics, control, and communication protocols implemented. Our dyn-e-pill devices can be actuated for over 350 h with two pill retrievals per hour. We challenged the charging circuit and demonstrated that the system has a lifetime longer than 6 h with a 30 min charging cycle, while it lasts for 14 h of uninterrupted use with a full charge.

  4. Dynamical Systems Theory: Application to Pedagogy

    Science.gov (United States)

    Abraham, Jane L.

    Theories of learning affect how cognition is viewed, and this subsequently leads to the style of pedagogical practice that is used in education. Traditionally, educators have relied on a variety of theories on which to base pedagogy. Behavioral learning theories influenced the teaching/learning process for over 50 years. In the 1960s, the information processing approach brought the mind back into the learning process. The current emphasis on constructivism integrates the views of Piaget, Vygotsky, and cognitive psychology. Additionally, recent scientific advances have allowed researchers to shift attention to biological processes in cognition. The problem is that these theories do not provide an integrated approach to understanding principles responsible for differences among students in cognitive development and learning ability. Dynamical systems theory offers a unifying theoretical framework to explain the wider context in which learning takes place and the processes involved in individual learning. This paper describes how principles of Dynamic Systems Theory can be applied to cognitive processes of students, the classroom community, motivation to learn, and the teaching/learning dynamic giving educational psychologists a framework for research and pedagogy.

  5. Computation in Dynamically Bounded Asymmetric Systems

    Science.gov (United States)

    Rutishauser, Ueli; Slotine, Jean-Jacques; Douglas, Rodney

    2015-01-01

    Previous explanations of computations performed by recurrent networks have focused on symmetrically connected saturating neurons and their convergence toward attractors. Here we analyze the behavior of asymmetrical connected networks of linear threshold neurons, whose positive response is unbounded. We show that, for a wide range of parameters, this asymmetry brings interesting and computationally useful dynamical properties. When driven by input, the network explores potential solutions through highly unstable ‘expansion’ dynamics. This expansion is steered and constrained by negative divergence of the dynamics, which ensures that the dimensionality of the solution space continues to reduce until an acceptable solution manifold is reached. Then the system contracts stably on this manifold towards its final solution trajectory. The unstable positive feedback and cross inhibition that underlie expansion and divergence are common motifs in molecular and neuronal networks. Therefore we propose that very simple organizational constraints that combine these motifs can lead to spontaneous computation and so to the spontaneous modification of entropy that is characteristic of living systems. PMID:25617645

  6. Geometric methods for discrete dynamical systems

    CERN Document Server

    Easton, Robert W

    1998-01-01

    This book looks at dynamics as an iteration process where the output of a function is fed back as an input to determine the evolution of an initial state over time. The theory examines errors which arise from round-off in numerical simulations, from the inexactness of mathematical models used to describe physical processes, and from the effects of external controls. The author provides an introduction accessible to beginning graduate students and emphasizing geometric aspects of the theory. Conley''s ideas about rough orbits and chain-recurrence play a central role in the treatment. The book will be a useful reference for mathematicians, scientists, and engineers studying this field, and an ideal text for graduate courses in dynamical systems.

  7. Resetting dynamic behaviour of pipework systems

    International Nuclear Information System (INIS)

    Gaudin, M.

    1997-01-01

    Resetting models is applied to electricity generating plant pipework systems. A frequency approach to the problem is made in an original way thanks to the use of precise dynamic rigidity matrices. The method assumes two kinds of unknown: the usually processed mechanical characteristics (Young's Modulus, density etc.) and new resetting parameters acting on the dynamic behaviour of unknown connections. As the latter have a very wide range of possible variation, they benefit from a change of variable which allows the assumptions formulated to be complied with. The minimized cost function is based on a error in load. The frequencies required for building it are automatically selected thanks to different tests on measurements. Minimization uses a sensitivity technique linked with a method of least standard squares. The method has been programmed in Fortran 90 within the CIRCUS code and tried out on various examples which were simulated and sound effects cases as well as an actual case. (author)

  8. System and mathematical modeling of quadrotor dynamics

    Science.gov (United States)

    Goodman, Jacob M.; Kim, Jinho; Gadsden, S. Andrew; Wilkerson, Stephen A.

    2015-05-01

    Unmanned aerial systems (UAS) are becoming increasingly visible in our daily lives; and range in operation from search and rescue, monitoring hazardous environments, and to the delivery of goods. One of the most popular UAS are based on a quad-rotor design. These are typically small devices that rely on four propellers for lift and movement. Quad-rotors are inherently unstable, and rely on advanced control methodologies to keep them operating safely and behaving in a predictable and desirable manner. The control of these devices can be enhanced and improved by making use of an accurate dynamic model. In this paper, we examine a simple quadrotor model, and note some of the additional dynamic considerations that were left out. We then compare simulation results of the simple model with that of another comprehensive model.

  9. Dynamical systems with applications using Mathematica

    CERN Document Server

    Lynch, Stephen

    2017-01-01

    This textbook, now in its second edition, provides a broad introduction to the theory and practice of both continuous and discrete dynamical systems with the aid of the Mathematica software suite. Taking a hands-on approach, the reader is guided from basic concepts to modern research topics. Emphasized throughout are numerous applications to biology, chemical kinetics, economics, electronics, epidemiology, nonlinear optics, mechanics, population dynamics, and neural networks. The book begins with an efficient tutorial introduction to Mathematica, enabling new users to become familiar with the program, while providing a good reference source for experts. Working Mathematica notebooks will be available at: http://library.wolfram.com/infocenter/Books/9563/ The author has focused on breadth of coverage rather than fine detail, with theorems and proofs being kept to a minimum, though references are included for the inquisitive reader. The book is intended for senior undergraduate and graduate students as well as w...

  10. On potential kernels associated with random dynamical systems

    Directory of Open Access Journals (Sweden)

    Mohamed Hmissi

    2015-01-01

    In particular, we provide a constructive method for global Lyapunov functions for gradient-like random dynamical systems. This result generalizes an analogous theorem known for deterministic dynamical systems.

  11. Modeling the Dynamic Digestive System Microbiome

    Directory of Open Access Journals (Sweden)

    Anne M. Estes

    2015-08-01

    Full Text Available “Modeling the Dynamic Digestive System Microbiome” is a hands-on activity designed to demonstrate the dynamics of microbiome ecology using dried pasta and beans to model disturbance events in the human digestive system microbiome. This exercise demonstrates how microbiome diversity is influenced by: 1 niche availability and habitat space and 2 a major disturbance event, such as antibiotic use. Students use a pictorial key to examine prepared models of digestive system microbiomes to determine what the person with the microbiome “ate.” Students then model the effect of taking antibiotics by removing certain “antibiotic sensitive” pasta. Finally, they add in “environmental microbes” or “native microbes” to recolonize the digestive system, determine how resilient their model microbome community is to disturbance, and discuss the implications. Throughout the exercise, students discuss differences in the habitat space available and microbiome community diversity. This exercise can be modified to discuss changes in the microbiome due to diet shifts and the emergence of antibiotic resistance in more depth.

  12. Modelling the crop: from system dynamics to systems biology

    NARCIS (Netherlands)

    Yin, X.; Struik, P.C.

    2010-01-01

    There is strong interplant competition in a crop stand for various limiting resources, resulting in complex compensation and regulation mechanisms along the developmental cascade of the whole crop. Despite decades-long use of principles in system dynamics (e.g. feedback control), current crop models

  13. Dynamic loads on the primary system

    International Nuclear Information System (INIS)

    Rohde, J.

    1980-01-01

    As a result of pipe breaks f.ex. in the primary system of a PWR-plant dynamic forces act on the components of the system as well as on their support-structures and internals. The design basis must guarantee that LOCA or system-transient generated loads cannot produce deformations or fractures that endanger the coolability of the reactor, the emergency feedwater supply to the core-region and a safe shut-down of the reactor. In this lecture the first part of a LOCA will be discussed, where the highest dynamic loads on the primary system are expected. In this connection comments are given on the main assumptions and boundary conditions, the related regulations and guide-lines, as well as the possible consequences of an accident. Next, a review is presented of the analytical methods being used for the determination of thermohydraulic generated loads. The stress-calculations on the basis of these load-functions are discussed in the following lectures. The application of the analytical methods, i.e. the different computer codes, and the verification on the basis of the experimental results are described together with a discussion of the theoretical results. In addition a survey will be given of the research work done in connection with the problems of the dynamic loads under accident conditions. Finally, the problems of the fluid-structure interaction will be explained and comments made on computer code development now under way regarding this problem. A short film will be presented to provide a better understanding of fast transient phenomena. (orig./RW)

  14. Description of the grout system dynamic simulation

    International Nuclear Information System (INIS)

    Zimmerman, B.D.

    1993-07-01

    The grout system dynamic computer simulation was created to allow investigation of the ability of the grouting system to meet established milestones, for various assumed system configurations and parameters. The simulation simulates the movement of tank waste through the system versus time, from initial storage tanks, through feed tanks and the grout plant, then finally to a grout vault. The simulation properly accounts for the following (1) time required to perform various actions or processes, (2) delays involved in gaining regulatory approval, (3) random system component failures, (4) limitations on equipment capacities, (5) available parallel components, and (6) different possible strategies for vault filling. The user is allowed to set a variety of system parameters for each simulation run. Currently, the output of a run primarily consists of a plot of projected grouting campaigns completed versus time, for comparison with milestones. Other outputs involving any model component can also be quickly created or deleted as desired. In particular, sensitivity runs where the effect of varying a model parameter (flow rates, delay times, number of feed tanks available, etc.) on the ability of the system to meet milestones can be made easily. The grout system simulation was implemented using the ITHINK* simulation language for Macintosh** computers

  15. Dynamic Analysis of Power System Voltage Stability.

    Science.gov (United States)

    Gebreselassie, Assefa

    This thesis investigates the effects of loads and voltage regulators on the dynamic voltage stability of power systems. The analysis focuses on the interactions of machine flux dynamics with loads and voltage control devices. The results are based on eigenvalue analysis of the linearized models and time simulation of the nonlinear models, using models from the Power System Toolbox, a Matlab -based package for the simulation and small signal analysis of nonlinear power systems. The voltage stability analysis results are developed using a single machine single load system with typical machine and network parameters and the NPCC 10-machine system. Dynamic models for generators, exciters and loads are used. The generator is modeled with a pair of poles and one damper circuit in both the d-axis and the q-axis. Saturation effects are included in the model. The IEEE Type DC1 DC commutator exciter model is used for all the exciters. Five different types of loads: constant impedance, constant current, constant power, a first order induction motor model (slip model) and a third order induction motor model (slip-flux model) are considered. The modes of instability and the stability limits of the different representation of loads are examined for two different operating modes of the exciters. The first, when all the exciters are on automatic control and the second when some exciters are on manual control. Modal participation factors are used to determine the characteristics of the critical modes. The characteristics of the unstable modes are verified by performing time simulation of the nonlinear models. Oscillatory and non-oscillatory instabilities are experienced by load buses when all the exciters are on automatic control and some exciters are on manual control respectively, for loads which are predominantly constant power and induction motors. It is concluded that the mode of instability does not depend on the type of loads but on the operating condition of the exciters

  16. Extensions to Dynamic System Simulation of Fissile Solution Systems

    Energy Technology Data Exchange (ETDEWEB)

    Klein, Steven Karl [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bernardin, John David [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kimpland, Robert Herbert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Spernjak, Dusan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-08-24

    Previous reports have documented the results of applying dynamic system simulation (DSS) techniques to model a variety of fissile solution systems. The SUPO (Super Power) aqueous homogeneous reactor (AHR) was chosen as the benchmark for comparison of model results to experimental data for steadystate operation.1 Subsequently, DSS was applied to additional AHR to verify results obtained for SUPO and extend modeling to prompt critical excursions, ramp reactivity insertions of various magnitudes and rate, and boiling operations in SILENE and KEWB (Kinetic Experiment Water Boiler).2 Additional models for pressurized cores (HRE: Homogeneous Reactor Experiment), annular core geometries, and accelerator-driven subcritical systems (ADAHR) were developed and results reported.3 The focus of each of these models is core dynamics; neutron kinetics, thermal hydraulics, radiolytic gas generation and transport are coupled to examine the time-based evolution of these systems from start-up through transition to steady-state. A common characteristic of these models is the assumption that (a) core cooling system inlet temperature and flow and (b) plenum gas inlet pressure and flow are held constant; no external (to core) component operations that may result in dynamic change to these parameters are considered. This report discusses extension of models to include explicit reference to cooling structures and radiolytic gas handling. The accelerator-driven subcritical generic system model described in References 3 and 4 is used as a basis for this extension.

  17. Dynamic Systems Analysis for Turbine Based Aero Propulsion Systems

    Science.gov (United States)

    Csank, Jeffrey T.

    2016-01-01

    The aircraft engine design process seeks to optimize the overall system-level performance, weight, and cost for a given concept. Steady-state simulations and data are used to identify trade-offs that should be balanced to optimize the system in a process known as systems analysis. These systems analysis simulations and data may not adequately capture the true performance trade-offs that exist during transient operation. Dynamic systems analysis provides the capability for assessing the dynamic tradeoffs at an earlier stage of the engine design process. The dynamic systems analysis concept, developed tools, and potential benefit are presented in this paper. To provide this capability, the Tool for Turbine Engine Closed-loop Transient Analysis (TTECTrA) was developed to provide the user with an estimate of the closed-loop performance (response time) and operability (high pressure compressor surge margin) for a given engine design and set of control design requirements. TTECTrA along with engine deterioration information, can be used to develop a more generic relationship between performance and operability that can impact the engine design constraints and potentially lead to a more efficient engine.

  18. Solar Dynamic Power System Fault Diagnosis

    Science.gov (United States)

    Momoh, James A.; Dias, Lakshman G.

    1996-01-01

    The objective of this research is to conduct various fault simulation studies for diagnosing the type and location of faults in the power distribution system. Different types of faults are simulated at different locations within the distribution system and the faulted waveforms are monitored at measurable nodes such as at the output of the DDCU's. These fault signatures are processed using feature extractors such as FFT and wavelet transforms. The extracted features are fed to a clustering based neural network for training and subsequent testing using previously unseen data. Different load models consisting of constant impedance and constant power are used for the loads. Open circuit faults and short circuit faults are studied. It is concluded from present studies that using features extracted from wavelet transforms give better success rates during ANN testing. The trained ANN's are capable of diagnosing fault types and approximate locations in the solar dynamic power distribution system.

  19. Kawasaki Dynamics on Bidimensional Spin Systems

    Science.gov (United States)

    Resende, Denilson C.; Cacüador, Felipe C.; Dantas, Sócrates O.

    Under the influence of an external field many systems exhibit slow relaxations processes. In that sense, we study the Physics of this behavior/process in the early stages of its evolution on bidimensional Ising systems using Monte Carlo simulations at a broad range of temperature and spins up concentration. The Monte Carlo simulations were done up to second neighbors interactions shown a more stable dynamic regime than first neighbors interactions, when the systems energy is considered. The behavior of relative energy/spin and the relative perimeter (the line between spin up and spin down regions) are monitored against Monte Carlo steps. Also, our findings show that the stretching index (a2) exhibit values below the borderline (1) in a broad range of concentration below 50% and temperature from 0.5 ≤T ≤ 4.5 (in units of J/kB , where J is the ferromagnetic constant and kB is the Boltzmann constant).

  20. Systems approaches to study root architecture dynamics

    Directory of Open Access Journals (Sweden)

    Candela eCuesta

    2013-12-01

    Full Text Available The plant root system is essential for providing anchorage to the soil, supplying minerals and water, and synthesizing metabolites. It is a dynamic organ modulated by external cues such as environmental signals, water and nutrients availability, salinity and others. Lateral roots are initiated from the primary root post-embryonically, after which they progress through discrete developmental stages which can be independently controlled, providing a high level of plasticity during root system formation.Within this review, main contributions are presented, from the classical forward genetic screens to the more recent high-throughput approaches, combined with computer model predictions, dissecting how lateral roots and thereby root system architecture is established and developed.

  1. Structural system identification: Structural dynamics model validation

    Energy Technology Data Exchange (ETDEWEB)

    Red-Horse, J.R.

    1997-04-01

    Structural system identification is concerned with the development of systematic procedures and tools for developing predictive analytical models based on a physical structure`s dynamic response characteristics. It is a multidisciplinary process that involves the ability (1) to define high fidelity physics-based analysis models, (2) to acquire accurate test-derived information for physical specimens using diagnostic experiments, (3) to validate the numerical simulation model by reconciling differences that inevitably exist between the analysis model and the experimental data, and (4) to quantify uncertainties in the final system models and subsequent numerical simulations. The goal of this project was to develop structural system identification techniques and software suitable for both research and production applications in code and model validation.

  2. Dynamics of coupled human-landscape systems

    Science.gov (United States)

    Werner, B. T.; McNamara, D. E.

    2007-11-01

    A preliminary dynamical analysis of landscapes and humans as hierarchical complex systems suggests that strong coupling between the two that spreads to become regionally or globally pervasive should be focused at multi-year to decadal time scales. At these scales, landscape dynamics is dominated by water, sediment and biological routing mediated by fluvial, oceanic, atmospheric processes and human dynamics is dominated by simplifying, profit-maximizing market forces and political action based on projection of economic effect. Also at these scales, landscapes impact humans through patterns of natural disasters and trends such as sea level rise; humans impact landscapes by the effect of economic activity and changes meant to mitigate natural disasters and longer term trends. Based on this analysis, human-landscape coupled systems can be modeled using heterogeneous agents employing prediction models to determine actions to represent the nonlinear behavior of economic and political systems and rule-based routing algorithms to represent landscape processes. A cellular model for the development of New Orleans illustrates this approach, with routing algorithms for river and hurricane-storm surge determining flood extent, five markets (home, labor, hotel, tourism and port services) connecting seven types of economic agents (home buyers/laborers, home developers, hotel owners/ employers, hotel developers, tourists, port services developer and port services owners/employers), building of levees or a river spillway by political agents and damage to homes, hotels or port services within cells determined by the passage or depth of flood waters. The model reproduces historical aspects of New Orleans economic development and levee construction and the filtering of frequent small-scale floods at the expense of large disasters.

  3. Delay differential systems for tick population dynamics.

    Science.gov (United States)

    Fan, Guihong; Thieme, Horst R; Zhu, Huaiping

    2015-11-01

    Ticks play a critical role as vectors in the transmission and spread of Lyme disease, an emerging infectious disease which can cause severe illness in humans or animals. To understand the transmission dynamics of Lyme disease and other tick-borne diseases, it is necessary to investigate the population dynamics of ticks. Here, we formulate a system of delay differential equations which models the stage structure of the tick population. Temperature can alter the length of time delays in each developmental stage, and so the time delays can vary geographically (and seasonally which we do not consider). We define the basic reproduction number [Formula: see text] of stage structured tick populations. The tick population is uniformly persistent if [Formula: see text] and dies out if [Formula: see text]. We present sufficient conditions under which the unique positive equilibrium point is globally asymptotically stable. In general, the positive equilibrium can be unstable and the system show oscillatory behavior. These oscillations are primarily due to negative feedback within the tick system, but can be enhanced by the time delays of the different developmental stages.

  4. Reliability of dynamic systems under limited information.

    Energy Technology Data Exchange (ETDEWEB)

    Field, Richard V., Jr. (.,; .); Grigoriu, Mircea

    2006-09-01

    A method is developed for reliability analysis of dynamic systems under limited information. The available information includes one or more samples of the system output; any known information on features of the output can be used if available. The method is based on the theory of non-Gaussian translation processes and is shown to be particularly suitable for problems of practical interest. For illustration, we apply the proposed method to a series of simple example problems and compare with results given by traditional statistical estimators in order to establish the accuracy of the method. It is demonstrated that the method delivers accurate results for the case of linear and nonlinear dynamic systems, and can be applied to analyze experimental data and/or mathematical model outputs. Two complex applications of direct interest to Sandia are also considered. First, we apply the proposed method to assess design reliability of a MEMS inertial switch. Second, we consider re-entry body (RB) component vibration response during normal re-entry, where the objective is to estimate the time-dependent probability of component failure. This last application is directly relevant to re-entry random vibration analysis at Sandia, and may provide insights on test-based and/or model-based qualification of weapon components for random vibration environments.

  5. Dynamical instabilities in spherical stellar systems

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, J.; Hut, P.; Goodman, J.

    1986-01-01

    The first numerical examples of spherical stellar systems in equilibrium, which are unstable on a dynamical time scale, were found by Henon using N-body code with enforced spherical symmetry. Henon's models have been reexamined using a code which includes nonradical forces to quadrupole order; the key results have been checked using a direct-summation Aarseth code. The radial instability reported by Henon is confirmed; in addition, two nonradial instabilities have been found. In the first kind, seen in models with predominantly radial orbits, the system permanently loses spherical symmetry and settles into a strongly triaxial ellipsoid. In the second kind, which appears in models with nearly circular orbits, the mass distribution exhibits quadrupole-mode oscillations. Analytic estimates and physical interpretations are presented for all three instabilities. The nonradial instabilities are found even in cases where the distribution function decreases with energy, suggesting that dynamical instabilities may be more common in spherical systems than had been previously thought. 25 references.

  6. The self as a complex dynamic system

    Directory of Open Access Journals (Sweden)

    Sarah Mercer

    2011-04-01

    Full Text Available This article explores the potential offered by complexity theories for understanding language learners’ sense of self and attempts to show how the self might usefully be conceived of as a complex dynamic system. Rather than presenting empirical findings, the article discusses existent research on the self and aims at outlining a conceptual perspective that may inform future studies into the self and possibly other individual learner differences. The article concludes by critically considering the merits of a complexity perspective but also reflecting on the challenges it poses for research.

  7. Dynamic system evolution and markov chain approximation

    Directory of Open Access Journals (Sweden)

    Roderick V. Nicholas Melnik

    1998-01-01

    Full Text Available In this paper computational aspects of the mathematical modelling of dynamic system evolution have been considered as a problem in information theory. The construction of mathematical models is treated as a decision making process with limited available information.The solution of the problem is associated with a computational model based on heuristics of a Markov Chain in a discrete space–time of events. A stable approximation of the chain has been derived and the limiting cases are discussed. An intrinsic interconnection of constructive, sequential, and evolutionary approaches in related optimization problems provides new challenges for future work.

  8. Correlated Levy Noise in Linear Dynamical Systems

    International Nuclear Information System (INIS)

    Srokowski, T.

    2011-01-01

    Linear dynamical systems, driven by a non-white noise which has the Levy distribution, are analysed. Noise is modelled by a specific stochastic process which is defined by the Langevin equation with a linear force and the Levy distributed symmetric white noise. Correlation properties of the process are discussed. The Fokker-Planck equation driven by that noise is solved. Distributions have the Levy shape and their width, for a given time, is smaller than for processes in the white noise limit. Applicability of the adiabatic approximation in the case of the linear force is discussed. (author)

  9. Electron dynamics inside short-coherence systems

    International Nuclear Information System (INIS)

    Ferrari, Giulio; Bordone, Paolo; Jacoboni, Carlo

    2006-01-01

    We present theoretical results on electron dynamics inside nanometric systems, where the coherence of the electron ensemble is maintained in a very short region. The contacts are supposed to spoil such a coherence, therefore the interference processes between the carrier wavefunction and the internal potential profile can be affected by the proximity of the contacts. The problem has been analysed by using the Wigner-function formalism. For very short devices, transport properties, such as tunnelling through potential barriers, are significantly influenced by the distance between the contacts

  10. Advances in dynamical systems and control

    CERN Document Server

    Zgurovsky, Mikhail

    2016-01-01

    Focused on recent advances, this book covers theoretical foundations as well as various applications. It presents modern mathematical modeling approaches to the qualitative and numerical analysis of solutions for complex engineering problems in physics, mechanics, biochemistry, geophysics, biology and climatology. Contributions by an international team of respected authors bridge the gap between abstract mathematical approaches, such as applied methods of modern analysis, algebra, fundamental and computational mechanics, nonautonomous and stochastic dynamical systems on the one hand, and practical applications in nonlinear mechanics, optimization, decision making theory and control theory on the other. As such, the book will be of interest to mathematicians and engineers working at the interface of these fields. .

  11. Management of Mass Casualties Using Doctor Helicopters and Doctor Cars.

    Science.gov (United States)

    Ohsaka, Hiromichi; Ishikawa, Kouhei; Omori, Kazuhiko; Jitsuiki, Kei; Yoshizawa, Toshihiko; Yanagawa, Youichi

    At approximately 10 o'clock in September 2015, a minibus carrying 18 people accidentally slid backwards because of a malfunctioning brake system while climbing a steep incline on Togasayama Mountain, colliding with a van (Toyota HiAce wagon) carrying 11 people that was situated behind the minibus. Togasayama Mountain is located 1 hour by car and 10 minutes by helicopter from our hospital. The minibus slid off a roadside cliff at a height of 0.5 m and rolled over after colliding with the van. There were 7 victims with yellow tags and 22 with green tags. Two Doctor Helicopters and 1 Doctor Car cooperated with the fire departments by providing medical treatments, selection of medical facilities, and dispersion transportation. In this mass casualty event, there were no mortalities, and all of the victims recovered without sequelae. The coordinated and combined use of Doctor Helicopters and Doctor Cars in addition to the activities of the fire department in response to a mass casualty event resulted in appropriate triage, medical treatments, selection of medical facilities, and dispersion transportation. Copyright © 2017 Air Medical Journal Associates. Published by Elsevier Inc. All rights reserved.

  12. The doctoral learning penumbra

    DEFF Research Database (Denmark)

    Bengtsen, Søren Smedegaard; Robinson, Gill; Wisker, Gina

    This paper presents our cross-national research into what we term the ‘doctoral learning penumbra’, which covers the diverse, unnoticed, and often unrecognised forms of help and support that doctoral students draw from during their PhD, and which are vital for completion. Our aim is to better und...

  13. Talking to Your Doctor

    Medline Plus

    Full Text Available ... Discovery Into Health ® Impact of NIH Research Science, Health, and Public Trust You are here Home » Institutes at NIH » ... Access Talking to Your Doctor Plain Language Science, Health, and Public Trust Talking to Your Doctor Part I: Preparing ...

  14. Talking to Your Doctor

    Medline Plus

    Full Text Available ... Your Medical Provider (3:51) Part III: Understanding Diagnosis and Treatment (3:57) More Resources from NIH ... Your Doctor , National Eye Institute (NEI) Español Aging Planning Your Doctor Visit , NIHSeniorHealth.gov Videos: Talking with ...

  15. Talking to Your Doctor

    Medline Plus

    Full Text Available ... NIH Website NIH Employee Intranet Staff Directory En Español Site Menu Home Health Information Health Info Lines ... Talking With Your Doctor , NIH News in Health Español Talking to Your Doctor , National Eye Institute (NEI) ...

  16. Scalable persistent identifier systems for dynamic datasets

    Science.gov (United States)

    Golodoniuc, P.; Cox, S. J. D.; Klump, J. F.

    2016-12-01

    Reliable and persistent identification of objects, whether tangible or not, is essential in information management. Many Internet-based systems have been developed to identify digital data objects, e.g., PURL, LSID, Handle, ARK. These were largely designed for identification of static digital objects. The amount of data made available online has grown exponentially over the last two decades and fine-grained identification of dynamically generated data objects within large datasets using conventional systems (e.g., PURL) has become impractical. We have compared capabilities of various technological solutions to enable resolvability of data objects in dynamic datasets, and developed a dataset-centric approach to resolution of identifiers. This is particularly important in Semantic Linked Data environments where dynamic frequently changing data is delivered live via web services, so registration of individual data objects to obtain identifiers is impractical. We use identifier patterns and pattern hierarchies for identification of data objects, which allows relationships between identifiers to be expressed, and also provides means for resolving a single identifier into multiple forms (i.e. views or representations of an object). The latter can be implemented through (a) HTTP content negotiation, or (b) use of URI querystring parameters. The pattern and hierarchy approach has been implemented in the Linked Data API supporting the United Nations Spatial Data Infrastructure (UNSDI) initiative and later in the implementation of geoscientific data delivery for the Capricorn Distal Footprints project using International Geo Sample Numbers (IGSN). This enables flexible resolution of multi-view persistent identifiers and provides a scalable solution for large heterogeneous datasets.

  17. Major Depression as a Complex Dynamic System.

    Directory of Open Access Journals (Sweden)

    Angélique O J Cramer

    Full Text Available In this paper, we characterize major depression (MD as a complex dynamic system in which symptoms (e.g., insomnia and fatigue are directly connected to one another in a network structure. We hypothesize that individuals can be characterized by their own network with unique architecture and resulting dynamics. With respect to architecture, we show that individuals vulnerable to developing MD are those with strong connections between symptoms: e.g., only one night of poor sleep suffices to make a particular person feel tired. Such vulnerable networks, when pushed by forces external to the system such as stress, are more likely to end up in a depressed state; whereas networks with weaker connections tend to remain in or return to a non-depressed state. We show this with a simulation in which we model the probability of a symptom becoming 'active' as a logistic function of the activity of its neighboring symptoms. Additionally, we show that this model potentially explains some well-known empirical phenomena such as spontaneous recovery as well as accommodates existing theories about the various subtypes of MD. To our knowledge, we offer the first intra-individual, symptom-based, process model with the potential to explain the pathogenesis and maintenance of major depression.

  18. Adding Dynamic Innovation to Environmental Management Systems

    DEFF Research Database (Denmark)

    Schmidt, Kirsten

    Over the last two decades, a number of organizations have implemented Environmental Management Systems (EMS) to assure a systematic approach and continuous improvements. Such systems include a number of “rules” for specific actions to be taken by members of the organization in given situations....... While such procedures may ensure a certain level of environmental effort they also tend to favor a learning style in the organization based on optimization of already known actions. This is among other things due to the fact that a certified EMS should include regular audits, and to the people...... to the ongoing development of the organization? Based on a case study in a global, but Danish based production company, the paper discusses the development of more dynamic, yet still systematic, environmental effort in organizations by introducing a matrix structure of the environmental management. In the matrix...

  19. Cultural initiation of medical doctors.

    Science.gov (United States)

    Zsinkó-Szabó, Zoltán; Lázár, Imre

    2013-12-01

    Eighteen years experience of teaching medical anthropology at a Hungarian medical school offers insight into the dynamics of interference between the rationalist epistemological tradition of biomedicine as one of the central paradigms of modernism and the cultural relativism of medical anthropology, as cultural anthropology is considered to be one of the generators of postmodern thinking. Tracing back the informal "prehistory" of our Institute, we can reveal its psychosomatic, humanistic commitment and critical basis as having represented a kind of counterculture compared with the technocrats of state-socialist Hungary's health ideology. The historical change and socio-cultural transition in Hungary after 1989 was accompanied by changes in the medical system as well as in philosophy and in the structure of the teaching of social sciences. The developing pluralism in the medical system together with the pluralism of social ideologies allowed the substitution of the dogmatic Marxist-Leninist framework with the more pragmatic and empiricist behavioral sciences including medical sociology and medical anthropology. The conflict between the initiation function of the hard preclinical training of the first two years, and the reflective, relativistic and critical narrative on "biomedicine as culture bound entity" constructed by medical anthropology during the second year of medical training is discussed. We also submit our fieldwork data gained as a result of a two year investigation period focusing on diverse initiation types of "would be" physicians. The main proportion of our data derives from individual semi structured deep interviews together with focus group interviews carried out with medical students of upper years. Finally, the role of medical anthropology in the "rite of passage" of becoming a medical doctor is summarized, paying attention to their field work reports and the risks and gains in this process.

  20. On Dynamic Systems with Piecewise Linear Feature

    Directory of Open Access Journals (Sweden)

    Amalia Ţîrdea

    2010-10-01

    Full Text Available Impact dynamics is considered to be one of the most important problems which arise in vibrating systems. Such impact oscillator occurs in the motion with amplitude constraining stop. In the past years, this simple model has been found rich phenomena and given benefit for understanding of impact systems. Different types of impacting response, such as periodic and non-periodic oscillations, can be predicted by using bifurcation diagrams. Many mechanical systems in engineering applications represent systems which are driven in some way and which undergo intermittent or a continuous sequence of contacts with limiting motion by constraints. For example, the principles of the operation of vibration hammers, impact dampers, inertial shakers, milling and forming machines etc, are based on the impact action for moving bodies. With other equipment, machines with clearances, heat exchangers, steam generator tubes, fuel rods in nuclear power plants, rolling railway wheel sets, piping systems, gear transmissions and so on, impacts also occur, but they are undesirable as they bring about failures, strains, and increased noise levels.

  1. Dynamical evolution of spherical stellar systems

    International Nuclear Information System (INIS)

    Lee, H.M.

    1986-01-01

    The dynamical effect of heavy mass stars formed out of successive mergers among tidally captured binaries of evolution of spherical stellar systems is investigated. To maximize such effect assumed all tidally captured systems become mergers. Stellar evolution is simulated by computing mean age of mass group and applying death rate as function of mean age. For stellar systems with N = 10 5-6 , combined effect of three body binary heating among heavy mass stars and stellar evolution provides energy to drive post collapse expansion; long-term evolution is dominated by stellar evolution. Long-term behavior of clusters is similar to tidally captured binaries assuming no merger. Observed chemical inhomogeneities among stars in globular clusters may also be explained by stellar mergers. Three-body heating is important in small-N systems, while stellar evolution dominates evolution of large N systems. The effect of primordial degenerate stars is investigated in the second study. Very hard binaries composed of degenerate-normal pair form via tidal capture process and moderately hard degenerate-degenerate binaries form via three-body process. If initial degenerate population is large, initial core-collapse phase may be approximated as collapse of degenerate star. Three-body binaries among degenerate stars eventually provide enough energy to stop collapse and cause reexpansion

  2. Dynamics of human respiratory system mycoflora

    Directory of Open Access Journals (Sweden)

    Anna Biedunkiewicz

    2014-08-01

    Full Text Available The study aimed at determing the prevalence of individual species of fungi in the respiratory systems of women and men, analysis of the dynamics of the fungi in individual sections of the respiratory system as concerns their quantity and identification of phenology of the isolated fungi coupled with an attempt at identifying their possible preferences for appearing during specific seasons of thc year. During 10 years of studies (1989- 1998. 29 species of fungi belonging: Candida, Geolrichum, Saccharomyces, Saccharomycopsis, Schizosaccharomyces, Torulopsis, Trichosporon and Aspergillus were isolated from the ontocenoses of the respiratory systems of patients at the Independent Public Center for Pulmonology and Oncology in Olsztyn. Candida albicans was a clearly dominating fungus. Individual species appeared individually, in twos or threes in a single patient, they were isolated more frequently in the spring and autumn, less frequently during the winter and summer. The largest number of fungi species were isolated from sputum (29 species, bronchoscopic material (23 species and pharyngeal swabs (15 species. Sacchoromycopsis capsularis and Trichosporon beigelii should be treated as new for the respiratory system. Biodiversity of fungi, their numbers and continous fluctuations in frequency indicate that the respiratory system ontocenose offers the optimum conditions for growth and development of the majority of the majority of yeasts - like fungi.

  3. Response and Reliability Problems of Dynamic Systems

    DEFF Research Database (Denmark)

    Nielsen, Søren R. K.

    The present thesis consists of selected parts of the work performed by the author on stochastic dynamics and reliability theory of dynamically excited structures primarily during the period 1986-1996.......The present thesis consists of selected parts of the work performed by the author on stochastic dynamics and reliability theory of dynamically excited structures primarily during the period 1986-1996....

  4. A Dynamic Systems Theory approach to second language acquisition

    NARCIS (Netherlands)

    de Bot, K.; Lowie, W.M.; Verspoor, M.H.

    In this article it is argued that language can be seen as a dynamic system, i.e. a set of variables that interact over time, and that language development can be seen as a dynamic process. Language development shows some of the core characteristics of dynamic systems: sensitive dependence on initial

  5. Range use and dynamics in the agropastoral system of ...

    African Journals Online (AJOL)

    Occurrence of equilibrium and non equilibrium system dynamics in semiarid environments present serious management challenges. In these areas, resource management strategies are increasingly based on equilibrium rather than non equilibrium dynamics that assume simple system dynamics and strong coupling of ...

  6. A Dynamic Systems Approach to Internationalization of Higher Education

    Science.gov (United States)

    Zhou, Jiangyuan

    2016-01-01

    Research shows that internationalization of higher education is a process rather than an end product. This paper applies the Dynamic Systems Theory to examine the nature and development of internationalization of higher education, and proposes that internationalization of higher education is a dynamic system. A dynamic framework of…

  7. Dynamics of the Yellowstone hydrothermal system

    Science.gov (United States)

    Hurwitz, Shaul; Lowenstern, Jacob B.

    2014-01-01

    The Yellowstone Plateau Volcanic Field is characterized by extensive seismicity, episodes of uplift and subsidence, and a hydrothermal system that comprises more than 10,000 thermal features, including geysers, fumaroles, mud pots, thermal springs, and hydrothermal explosion craters. The diverse chemical and isotopic compositions of waters and gases derive from mantle, crustal, and meteoric sources and extensive water-gas-rock interaction at variable pressures and temperatures. The thermal features are host to all domains of life that utilize diverse inorganic sources of energy for metabolism. The unique and exceptional features of the hydrothermal system have attracted numerous researchers to Yellowstone beginning with the Washburn and Hayden expeditions in the 1870s. Since a seminal review published a quarter of a century ago, research in many fields has greatly advanced our understanding of the many coupled processes operating in and on the hydrothermal system. Specific advances include more refined geophysical images of the magmatic system, better constraints on the time scale of magmatic processes, characterization of fluid sources and water-rock interactions, quantitative estimates of heat and magmatic volatile fluxes, discovering and quantifying the role of thermophile microorganisms in the geochemical cycle, defining the chronology of hydrothermal explosions and their relation to glacial cycles, defining possible links between hydrothermal activity, deformation, and seismicity; quantifying geyser dynamics; and the discovery of extensive hydrothermal activity in Yellowstone Lake. Discussion of these many advances forms the basis of this review.

  8. Logic-Dynamic Approach to Fault Diagnosis in Mechatronic Systems

    Directory of Open Access Journals (Sweden)

    V. F. Filaretov

    2006-12-01

    Full Text Available This paper presents a problem of fault detection and isolation (FDI in mechatronic systems described by nonlinear dynamic models with such types of no differentiable nonlinearities as saturation, Coulomb friction, backlash, and hysteresis. To solve this problem, so-called logic-dynamic approach is suggested. This approach consists of three main steps: replacing the initial nonlinear system by certain linear logic-dynamic system, obtaining the bank of linear logic-dynamic observers, and transforming these observes into the nonlinear ones. Logic-dynamic approach allows one to use the linear FDI methods for diagnosis in nonlinear mechatronic systems.

  9. Dynamic Parameter-Control Chaotic System.

    Science.gov (United States)

    Hua, Zhongyun; Zhou, Yicong

    2016-12-01

    This paper proposes a general framework of 1-D chaotic maps called the dynamic parameter-control chaotic system (DPCCS). It has a simple but effective structure that uses the outputs of a chaotic map (control map) to dynamically control the parameter of another chaotic map (seed map). Using any existing 1-D chaotic map as the control/seed map (or both), DPCCS is able to produce a huge number of new chaotic maps. Evaluations and comparisons show that chaotic maps generated by DPCCS are very sensitive to their initial states, and have wider chaotic ranges, better unpredictability and more complex chaotic behaviors than their seed maps. Using a chaotic map of DPCCS as an example, we provide a field-programmable gate array design of this chaotic map to show the simplicity of DPCCS in hardware implementation, and introduce a new pseudo-random number generator (PRNG) to investigate the applications of DPCCS. Analysis and testing results demonstrate the excellent randomness of the proposed PRNG.

  10. Advances in dynamic network modeling in complex transportation systems

    CERN Document Server

    Ukkusuri, Satish V

    2013-01-01

    This book focuses on the latest in dynamic network modeling, including route guidance and traffic control in transportation systems and other complex infrastructure networks. Covers dynamic traffic assignment, flow modeling, mobile sensor deployment and more.

  11. Dynamic management of sustainable development methods for large technical systems

    CERN Document Server

    Krishans, Zigurds; Merkuryev, Yuri; Oleinikova, Irina

    2014-01-01

    Dynamic Management of Sustainable Development presents a concise summary of the authors' research in dynamic methods analysis of technical systems development. The text illustrates mathematical methods, with a focus on practical realization and applications.

  12. [The happy doctor].

    Science.gov (United States)

    van Dongen, Christel M P; van der Graaf, Yolanda

    2012-01-01

    Descriptive, questionnaire-based. To study what makes doctors and medical students happy: Descriptive, questionnaire-based. Descriptive, questionnaire-based. For the purposes of this study, doctors and medical students completed an online questionnaire in the summer of 2012. They were presented with questions enquiring into general characteristics and into happiness. We asked them to define happiness, and to describe their happiest moments. The results were interpreted with the aid of simple statistics. 401 doctors, registrars and medical students took part in the study. 41% of the respondents were male and 59% female. Average age was 40 years. Students, GPs, anaesthesiologists and internists were the best represented. On average, the participants gave their 'happiness' a score of 7.6. The younger doctors ( 48 years (7.8), which also explains the relatively low scores for students (7.1). GPs were the happiest, with an average score of 7.9, closely followed by the 'other doctors', with an average score of 7.8, and the medical specialists (7.6). Within the specialties, bearing in mind that the low numbers means that results should be interpreted with some caution, the doctors with 'minority specialties' were the happiest, followed by internists and the supporting specialties. Psychiatrists and surgical colleagues can be found at the bottom of the list. The determinants 'love and relationships' and 'family' contribute the most to feeling happy. Older doctors are happier than younger doctors and GPs are generally happier than medical specialists. The determinants 'love and relationships' and family' are the most important for doctors' happiness.

  13. AUSTRALIAN COMPETITION AND CONSUMER COMMISSION v ACN 117 372 915: SHOULD CONSUMER LAW REGULATE DOCTOR-PATIENT RELATIONS IN A CORPORATISED HEALTH CARE SYSTEM?

    Science.gov (United States)

    Wallace, Jessica; Pyman, Ella; Faunce, Thomas

    2015-09-01

    In April 2015, North J of the Federal Court of Australia made a finding of unconscionable conduct against Advanced Medical Institute, a promoter and provider of erectile dysfunction treatment, in a case concerning unfair contract terms (Australian Competition and Consumer Commission vACN 117 372 915 Pty Ltd (in liq) (formerly Advanced Medical Institute Pty Ltd) [2015] FCA 368). The contract required a minimum 12-month commitment, with costs exceeding treatments available from general practitioners, and made refunds available only after all possible treatment plans were exhausted which included penile injections. This column analyses that case, particularly in respect to the consumer law standards of practice under which it was litigated. Those standards refer to patients as "consumers" yet North J made extensive reference to the Good Medical Practice: A Code of Conduct for Doctors in Australia, a text which refers to "patients", as evidence of what constitutes appropriate professional conduct or practice for the health profession. This column considers whether legislative and judicial categorisation of patients (a class of people presumptively suffering, sick and vulnerable) as "consumers" undermines the formal and informal protections accorded to patients under normative systems of medical ethics such as those represented by the Code. The case, it is argued, also illuminates the contemporary tensions between the ethical, legal and human rights standards required of doctors in their treatment of patients and the commercial interests of businesses.

  14. Dynamic Response of Wall Backfill Retaining System

    Directory of Open Access Journals (Sweden)

    Sreenivas Alampalli

    1997-01-01

    Full Text Available An in situ full-scale test is conducted to measure the dynamic response of a long cantilever wall that retains backfill soil. The recorded modal parameters of this retaining wall exhibited significant similarity to those of a clamped cantilever plate (rather than those of a cantilever beam or plane-strain analysis. Such a three-dimensional (3-D response pattern is not accounted for by current analysis procedures. A simple 3-D finite element model is employed to further analyze the observed resonant configurations. The results indicate that such configurations play an important role in the seismic response of wall backfill soil systems of variable height, such as wing walls supporting highway approach ramps.

  15. Dynamical system analysis of interacting models

    Science.gov (United States)

    Carneiro, S.; Borges, H. A.

    2018-01-01

    We perform a dynamical system analysis of a cosmological model with linear dependence between the vacuum density and the Hubble parameter, with constant-rate creation of dark matter. We show that the de Sitter spacetime is an asymptotically stable critical point, future limit of any expanding solution. Our analysis also shows that the Minkowski spacetime is an unstable critical point, which eventually collapses to a singularity. In this way, such a prescription for the vacuum decay not only predicts the correct future de Sitter limit, but also forbids the existence of a stable Minkowski universe. We also study the effect of matter creation on the growth of structures and their peculiar velocities, showing that it is inside the current errors of redshift space distortions observations.

  16. Dynamical Systems, Cytokine Storms, and Blood Filtration

    Science.gov (United States)

    Foster, Glenn; Hubler, Alfred

    2008-03-01

    Various infections and non-infectious diseases can trigger immune cells and the proteins (cytokines) the cells use to communicate with each other to be caught in a positive feedback loop; this ``cytokine storm'' is frequently fatal. By examining the network of cytokine-immune cell interactions we will illustrate why anti-mediator drugs have been generally ineffective in stopping this feedback. A more effective approach may be to try and reduce interactions by dampening many signals at once by filtering the cytokines out of the blood directly (think dialysis). We will argue that feedback on an out of control nonlinear dynamical system is easier to understand than its normal healthy state and apply filtration to a toy model of immune response.

  17. Dynamics of delayed piecewise linear systems

    Directory of Open Access Journals (Sweden)

    Laszlo E. Kollar

    2003-02-01

    Full Text Available In this paper the dynamics of the controlled pendulum is investigated assuming backlash and time delays. The upper equilibrium of the pendulum is stabilized by a piecewise constant control force which is the linear combination of the sampled values of the angle and the angular velocity of the pendulum. The control force is provided by a motor which drives one of the wheels of the cart through an elastic teeth belt. The contact between the teeth of the gear (rigid and the belt (elastic introduces a nonlinearity known as ``backlash" and causes the oscillation of the controlled pendulum around its upper equilibrium. The processing and sampling delays in the determination of the control force tend to destabilize the controlled system as well. We obtain conditions guaranteeing that the pendulum remains in the neighborhood of the upper equilibrium. Experimental findings obtained on a computer controlled inverted pendulum cart structure are also presented showing good agreement with the simulation results.

  18. Transport and Dynamics in Toroidal Fusion Systems

    International Nuclear Information System (INIS)

    Sovinec, Carl

    2016-01-01

    The study entitled, 'Transport and Dynamics in Toroidal Fusion Systems,' (TDTFS) applied analytical theory and numerical computation to investigate topics of importance to confining plasma, the fourth state of matter, with magnetic fields. A central focus of the work is how non-thermal components of the ion particle distribution affect the 'sawtooth' collective oscillation in the core of the tokamak magnetic configuration. Previous experimental and analytical research had shown and described how the oscillation frequency decreases and amplitude increases, leading to 'monster' or 'giant' sawteeth, when the non-thermal component is increased by injecting particle beams or by exciting ions with imposed electromagnetic waves. The TDTFS study applied numerical computation to self-consistently simulate the interaction between macroscopic collective plasma dynamics and the non-thermal particles. The modeling used the NIMROD code [Sovinec, Glasser, Gianakon, et al., J. Comput. Phys. 195, 355 (2004)] with the energetic component represented by simulation particles [Kim, Parker, Sovinec, and the NIMROD Team, Comput. Phys. Commun. 164, 448 (2004)]. The computations found decreasing growth rates for the instability that drives the oscillations, but they were ultimately limited from achieving experimentally relevant parameters due to computational practicalities. Nonetheless, this effort provided valuable lessons for integrated simulation of macroscopic plasma dynamics. It also motivated an investigation of the applicability of fluid-based modeling to the ion temperature gradient instability, leading to the journal publication [Schnack, Cheng, Barnes, and Parker, Phys. Plasmas 20, 062106 (2013)]. Apart from the tokamak-specific topics, the TDTFS study also addressed topics in the basic physics of magnetized plasma and in the dynamics of the reversed-field pinch (RFP) configuration. The basic physics work contributed to a study of two

  19. Transport and Dynamics in Toroidal Fusion Systems

    Energy Technology Data Exchange (ETDEWEB)

    Sovinec, Carl [Univ. of Wisconsin, Madison, WI (United States)

    2016-09-07

    The study entitled, "Transport and Dynamics in Toroidal Fusion Systems," (TDTFS) applied analytical theory and numerical computation to investigate topics of importance to confining plasma, the fourth state of matter, with magnetic fields. A central focus of the work is how non-thermal components of the ion particle distribution affect the "sawtooth" collective oscillation in the core of the tokamak magnetic configuration. Previous experimental and analytical research had shown and described how the oscillation frequency decreases and amplitude increases, leading to "monster" or "giant" sawteeth, when the non-thermal component is increased by injecting particle beams or by exciting ions with imposed electromagnetic waves. The TDTFS study applied numerical computation to self-consistently simulate the interaction between macroscopic collective plasma dynamics and the non-thermal particles. The modeling used the NIMROD code [Sovinec, Glasser, Gianakon, et al., J. Comput. Phys. 195, 355 (2004)] with the energetic component represented by simulation particles [Kim, Parker, Sovinec, and the NIMROD Team, Comput. Phys. Commun. 164, 448 (2004)]. The computations found decreasing growth rates for the instability that drives the oscillations, but they were ultimately limited from achieving experimentally relevant parameters due to computational practicalities. Nonetheless, this effort provided valuable lessons for integrated simulation of macroscopic plasma dynamics. It also motivated an investigation of the applicability of fluid-based modeling to the ion temperature gradient instability, leading to the journal publication [Schnack, Cheng, Barnes, and Parker, Phys. Plasmas 20, 062106 (2013)]. Apart from the tokamak-specific topics, the TDTFS study also addressed topics in the basic physics of magnetized plasma and in the dynamics of the reversed-field pinch (RFP) configuration. The basic physics work contributed to a study of two-fluid effects on interchange dynamics, where

  20. Towards a doctoral thesis through published works.

    Science.gov (United States)

    Breimer, L H; Mikhailidis, D P

    1993-01-01

    Doctoral theses submitted in medical schools under a system dependent on publications (Sweden) and one which was not (UK) were compared. A subset consisting of UK theses containing papers (about 1/3 of all UK theses) was used. The publication-based theses gave candidates a significantly higher (P thesis despite no requirement of publication. A publication-based doctorate should be introduced on trial in parallel with the existing systems to ensure efficiency and international comparability.

  1. RAPID DYNAMICAL CHAOS IN AN EXOPLANETARY SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Deck, Katherine M.; Winn, Joshua N. [Department of Physics and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Holman, Matthew J.; Carter, Joshua A.; Ragozzine, Darin [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Agol, Eric [Department of Astronomy, Box 351580, University of Washington, Seattle, WA 98195 (United States); Lissauer, Jack J. [NASA Ames Research Center, Moffet Field, CA 94035 (United States)

    2012-08-10

    We report on the long-term dynamical evolution of the two-planet Kepler-36 system, which consists of a super-Earth and a sub-Neptune in a tightly packed orbital configuration. The orbits of the planets, which we studied through numerical integrations of initial conditions that are consistent with observations of the system, are chaotic with a Lyapunov time of only {approx}10 years. The chaos is a consequence of a particular set of orbital resonances, with the inner planet orbiting 34 times for every 29 orbits of the outer planet. The rapidity of the chaos is due to the interaction of the 29:34 resonance with the nearby first-order 6:7 resonance, in contrast to the usual case in which secular terms in the Hamiltonian play a dominant role. Only one contiguous region of phase space, accounting for {approx}4.5% of the sample of initial conditions studied, corresponds to planetary orbits that do not show large-scale orbital instabilities on the timescale of our integrations ({approx}200 million years). Restricting the orbits to this long-lived region allows a refinement of estimates of the masses and radii of the planets. We find that the long-lived region consists of the initial conditions that satisfy the Hill stability criterion by the largest margin. Any successful theory for the formation of this system will need to account for why its current state is so close to unstable regions of phase space.

  2. Coupled dynamic systems and Le Chatelier's principle in noise control

    Science.gov (United States)

    Maidanik, G.; Becker, K. J.

    2004-05-01

    Investigation of coupling an externally driven dynamic system-a master dynamic system-to a passive one-an adjunct dynamic system-reveals that the response of the adjunct dynamic system affects the precoupled response of the master dynamic system. The responses, in the two dynamic systems when coupled, are estimated by the stored energies (Es) and (E0), respectively. Since the adjunct dynamic system, prior to coupling, was with zero (0) stored energy, E0s=0, the precoupled stored energy (E00) in the master dynamic system is expected to be reduced to (E0) when coupling is instituted; i.e., one expects E0dynamic system would result from the coupling. It is argued that the change in the disposition of the stored energies as just described may not be the only change. The coupling may influence the external input power into the master dynamic system which may interfere with the expected noise control. Indeed, the coupling may influence the external input power such that the expected beneficial noise control may not materialize. Examples of these kinds of noise control reversals are cited.

  3. Avoiding irreversible dynamics in quantum systems

    Science.gov (United States)

    Karasik, Raisa Iosifovna

    2009-10-01

    Devices that exploit laws of quantum physics offer revolutionary advances in computation and communication. However, building such devices presents an enormous challenge, since it would require technologies that go far beyond current capabilities. One of the main obstacles to building a quantum computer and devices needed for quantum communication is decoherence or noise that originates from the interaction between a quantum system and its environment, and which leads to the destruction of the fragile quantum information. Encoding into decoherence-free subspaces (DFS) provides an important strategy for combating decoherence effects in quantum systems and constitutes the focus of my dissertation. The theory of DFS relies on the existence of certain symmetries in the decoherence process, which allow some states of a quantum system to be completely decoupled from the environment and thus to experience no decoherence. In this thesis I describe various approaches to DFS that are developed in the current literature. Although the general idea behind various approaches to DFS is the same, I show that different mathematical definitions of DFS actually have different physical meaning. I provide a rigorous definition of DFS for every approach, explaining its physical meaning and relation to other definitions. I also examine the theory of DFS for Markovian systems. These are systems for which the environment has no memory, i.e., any change in the environment affects the quantum system instantaneously. Examples of such systems include many systems in quantum optics that have been proposed for implementation of a quantum computer, such as atomic and molecular gases, trapped ions, and quantum dots. Here I develop a rigorous theory that provides necessary and sufficient conditions for the existence of DFS. This theory allows us to identify a special new class of DFS that was not known before. Under particular circumstances, dynamics of a quantum system can connive together with

  4. Talking to Your Doctor

    Medline Plus

    Full Text Available ... can play an active role in your health care by talking to your doctor. Clear and honest ... Institute on Aging (NIA) Cancer Communication in Cancer Care , National Cancer Institute (NCI) Español Complementary and Integrative ...

  5. Talking to Your Doctor

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    Full Text Available ... Trials and You Talking to Your Doctor Science Education Resources Community Resources Clear Health A–Z Publications ... in Health NIH Research Matters NIH Record Research & Training Medical Research Initiatives Science Highlights Science Education Research ...

  6. Talking to Your Doctor

    Science.gov (United States)

    ... Vision Education Program Hispanic/Latino Program Vision and Aging Program African American Program ... Talking to Your Doctor Today, patients take an active role in their health care. You and your ...

  7. Talking to Your Doctor

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    Full Text Available ... concerns before your appointment. Consider bringing a close friend or family member with you. Take notes about what the doctor says, or ask a friend or family member to take notes for you. ...

  8. Talking to Your Doctor

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  9. Talking to Your Doctor

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  13. Finding the Right Doctor

    Science.gov (United States)

    ... you meet someone that doesn’t match your communication style, you should switch,” Dr. Krumholz said. Another part ... for looking around: When you feel that the communication style is not matching your own If your doctor ...

  14. Talking to Your Doctor

    Medline Plus

    Full Text Available ... Research Trials and You Talking to Your Doctor Science Education Resources Community Resources Clear Health A–Z Publications ... Record Research & Training Medical Research Initiatives Science Highlights Science Education Research in NIH Labs & Clinics Training Opportunities Library ...

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  17. Talking to Your Doctor

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    Full Text Available ... your appointment. Consider bringing a close friend or family member with you. Take notes about what the doctor says, or ask a friend or family member to take notes for you. Learn how ...

  18. Talking to Your Doctor

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  19. Talking to Your Doctor

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    Full Text Available ... Research Trials and You Talking to Your Doctor Science Education Resources Community Resources Clear Health A–Z ... Matters NIH Record Research & Training Medical Research Initiatives Science Highlights Science Education Research in NIH Labs & Clinics ...

  20. Direct adaptive control for nonlinear uncertain dynamical systems

    Science.gov (United States)

    Hayakawa, Tomohisa

    In light of the complex and highly uncertain nature of dynamical systems requiring controls, it is not surprising that reliable system models for many high performance engineering and life science applications are unavailable. In the face of such high levels of system uncertainty, robust controllers may unnecessarily sacrifice system performance whereas adaptive controllers are clearly appropriate since they can tolerate far greater system uncertainty levels to improve system performance. In this dissertation, we develop a Lyapunov-based direct adaptive and neural adaptive control framework that addresses parametric uncertainty, unstructured uncertainty, disturbance rejection, amplitude and rate saturation constraints, and digital implementation issues. Specifically, we consider the following research topics; direct adaptive control for nonlinear uncertain systems with exogenous disturbances; robust adaptive control for nonlinear uncertain systems; adaptive control for nonlinear uncertain systems with actuator amplitude and rate saturation constraints; adaptive reduced-order dynamic compensation for nonlinear uncertain systems; direct adaptive control for nonlinear matrix second-order dynamical systems with state-dependent uncertainty; adaptive control for nonnegative and compartmental dynamical systems with applications to general anesthesia; direct adaptive control of nonnegative and compartmental dynamical systems with time delay; adaptive control for nonlinear nonnegative and compartmental dynamical systems with applications to clinical pharmacology; neural network adaptive control for nonlinear nonnegative dynamical systems; passivity-based neural network adaptive output feedback control for nonlinear nonnegative dynamical systems; neural network adaptive dynamic output feedback control for nonlinear nonnegative systems using tapped delay memory units; Lyapunov-based adaptive control framework for discrete-time nonlinear systems with exogenous disturbances

  1. Female physicist doctoral experiences

    OpenAIRE

    Katherine P. Dabney; Robert H. Tai

    2013-01-01

    The underrepresentation of women in physics doctorate programs and in tenured academic positions indicates a need to evaluate what may influence their career choice and persistence. This qualitative paper examines eleven females in physics doctoral programs and professional science positions in order to provide a more thorough understanding of why and how women make career choices based on aspects both inside and outside of school and their subsequent interaction. Results indicate that female...

  2. Dynamics of Planetary Systems in Star Clusters

    Science.gov (United States)

    Spurzem, R.; Giersz, M.; Heggie, D. C.; Lin, D. N. C.

    2009-05-01

    At least 10%-15% of nearby Sunlike stars have known Jupiter-mass planets. In contrast, very few planets are found in mature open and globular clusters such as the Hyades and 47 Tuc. We explore here the possibility that this dichotomy is due to the postformation disruption of planetary systems associated with the stellar encounters in long-lived clusters. One supporting piece of evidence for this scenario is the discovery of freely floating low-mass objects in star forming regions. We use two independent numerical approaches, a hybrid Monte Carlo and a direct N-body method, to simulate the impact of the encounters. We show that the results of numerical simulations are in reasonable agreement with analytical determinations in the adiabatic and impulsive limits. They indicate that distant stellar encounters generally do not significantly modify the compact and nearly circular orbits. However, moderately close stellar encounters, which are likely to occur in dense clusters, can excite planets' orbital eccentricity and induce dynamical instability in systems that are closely packed with multiple planets. The disruption of planetary systems occurs primarily through occasional nearly parabolic, nonadiabatic encounters, though eccentricity of the planets evolves through repeated hyperbolic adiabatic encounters that accumulate small-amplitude changes. The detached planets are generally retained by the potential of their host clusters as free floaters in young stellar clusters such as σ Orionis. We compute effective cross sections for the dissolution of planetary systems and show that, for all initial eccentricities, dissolution occurs on timescales that are longer than the dispersion of small stellar associations, but shorter than the age of typical open and globular clusters. Although it is much more difficult to disrupt short-period planets, close encounters can excite modest eccentricity among them, such that subsequent tidal dissipation leads to orbital decay, tidal

  3. Celestial dynamics chaoticity and dynamics of celestial systems

    CERN Document Server

    Dvorak, Rudolf

    2013-01-01

    Written by an internationally renowned expert author and researcher, this monograph fills the need for a book conveying the sophisticated tools needed to calculate exo-planet motion and interplanetary space flight. It is unique in considering the critical problems of dynamics and stability, making use of the software Mathematica, including supplements for practical use of the formulae.A must-have for astronomers and applied mathematicians alike.

  4. Dynamics of dissipative systems and computational physics

    International Nuclear Information System (INIS)

    Adam, Gh.; Scutaru, H.; Ixaru, L.; Adam, S.; Rizea, M.; Stefanescu, E.; Mihalache, D.; Mazilu, D.; Crasovan, L.

    2002-01-01

    During the first year of research activity in the frame of this project there have been investigated two main topics: I. Dynamics of systems of fermions in complex dissipative media; II. Solitons with topologic charge in dissipative systems. An essential problem of the quantum information systems is the controllability and observability of the quantum states, generally described by Lindblad's master equation with phenomenological coefficients. In its usual form, this equation describes a decay of the mean-values, but not necessarily the expected decaying transitions. The basic and very difficult problem of a dissipative quantum theory is to project the evolution of the total system (the system of interest + the environment) on the space of the system of interest. In this case, one obtains a quantum master equation where the system evolution is described by two terms: 1) a Hamiltonian term for the processes with energy conservation, and 2) a non-Hamiltonian term with coefficients depending on the dissipative coupling. That means that a master equation is based on some approximations enabling the replacement of the operators of the dissipative environment with average value coefficients. It is often assumed that the evolution operators of the dissipative system define a semigroup, not a group as in the case of an isolated system. In this framework, Lindblad obtained a quantum master equation in agreement with all the quantum-mechanical principles. However, the Lindblad master equation was unable to secure a correct description of the decaying states. To do that, one has to take into account the transition operators between the system eigenstates with appropriate coefficients. Within this investigation, we have obtained an equation obeying to this requirement, giving the ρ(t) time derivative in terms of creation-annihilation operators of the single-particle states |i>, and λ ij , representing the dissipative coefficients, the microscopic expressions of which are

  5. Adequate doctor - patient communication

    Directory of Open Access Journals (Sweden)

    Janković Slobodan

    2013-01-01

    Full Text Available Communication process gives to physician necessary information for establishing diagnosis and prescribing therapy, and helps to a patient to gain confidence in his doctor and the prescribed treatment. The communication between doctor and his patient is enhanced by the following: openness and conscientiousness of the physician, serious approach to the patient, participation of the patient in decision-making, advanced age and higher education of the patient. On the other hand, communication is less efficient if the doctor has longer employment status, if he/her avoids disclosure of all relevant information to the patient, if he/her is emotionally separated from the patient, if the time for an encounter is limited, if the patient is passive and with unrealistic expectations, and if the doctor is expressing himself/herself unclearly. In order to improve communication with patients, doctors should follow these recommendations: keeping eye contact with a patient, releasing tension from his/her body language, taking detailed patient history with active listening and without interrupting of a patient, speaking clearly and slowly, using language understandable to a patient, treating patients with equality, disclosing all relevant information to the patient and sharing decisionmaking with the patient. Adequate communication between doctor and patient always brings better treatment outcomes.

  6. Dynamical systems theory for the Gardner equation

    Science.gov (United States)

    Saha, Aparna; Talukdar, B.; Chatterjee, Supriya

    2014-02-01

    The Gardner equation ut+auux+bu2ux+μuxxx=0 is a generic mathematical model for weakly nonlinear and weakly dispersive wave propagation when the effects of higher-order nonlinearity become significant. Using the so-called traveling wave ansatz u (x,t)=φ(ξ), ξ =x-vt (where v is the velocity of the wave) we convert the (1+1)-dimensional partial differential equation to a second-order ordinary differential equation in ϕ with an arbitrary constant and treat the latter equation by the methods of the dynamical systems theory. With some special attention on the equilibrium points of the equation, we derive an analytical constraint for admissible values of the parameters a, b, and μ. From the Hamiltonian form of the system we confirm that, in addition to the usual bright soliton solution, the equation can be used to generate three different varieties of internal waves of which one is a dark soliton recently observed in water [A. Chabchoub et al., Phys. Rev. Lett. 110, 124101 (2013), 10.1103/PhysRevLett.110.124101].

  7. Integrable topological billiards and equivalent dynamical systems

    Science.gov (United States)

    Vedyushkina, V. V.; Fomenko, A. T.

    2017-08-01

    We consider several topological integrable billiards and prove that they are Liouville equivalent to many systems of rigid body dynamics. The proof uses the Fomenko-Zieschang theory of invariants of integrable systems. We study billiards bounded by arcs of confocal quadrics and their generalizations, generalized billiards, where the motion occurs on a locally planar surface obtained by gluing several planar domains isometrically along their boundaries, which are arcs of confocal quadrics. We describe two new classes of integrable billiards bounded by arcs of confocal quadrics, namely, non-compact billiards and generalized billiards obtained by gluing planar billiards along non-convex parts of their boundaries. We completely classify non-compact billiards bounded by arcs of confocal quadrics and study their topology using the Fomenko invariants that describe the bifurcations of singular leaves of the additional integral. We study the topology of isoenergy surfaces for some non-convex generalized billiards. It turns out that they possess exotic Liouville foliations: the integral trajectories of the billiard that lie on some singular leaves admit no continuous extension. Such billiards appear to be leafwise equivalent to billiards bounded by arcs of confocal quadrics in the Minkowski metric.

  8. Impact of anticipation in dynamical systems

    Science.gov (United States)

    Gerlee, P.; Tunstrøm, K.; Lundh, T.; Wennberg, B.

    2017-12-01

    Many animals, including humans, have predictive capabilities and, presumably, base their behavioral decisions—at least partially—upon an anticipated state of their environment. We explore a minimal version of this idea in the context of particles that interact according to a pairwise potential. Anticipation enters the picture by calculating the interparticle forces from linear extrapolations of the particle positions some time τ in the future. Simulations show that for intermediate values of τ , compared to a transient time scale defined by the potential and the initial conditions, the particles form rotating clusters in which the particles are arranged in a hexagonal pattern. Analysis of the system shows that anticipation induces energy dissipation and we show that the kinetic energy asymptotically decays as 1 /t . Furthermore, we show that the angular momentum is not necessarily conserved for τ >0 , and that asymmetries in the initial condition therefore can cause rotational movement. These results suggest that anticipation could play an important role in collective behavior, since it may induce pattern formation and stabilizes the dynamics of the system.

  9. System dynamics in complex psychiatric treatment organizations.

    Science.gov (United States)

    Rosenheck, R

    1988-05-01

    One of the major challenges facing contemporary psychiatry is the coordination of diverse services through organizational integration. With increasing frequency, psychiatric treatment takes place in complex treatment systems composed of multiple inpatient and outpatient programs. Particularly in public health care systems serving the chronically ill, contemporary practice demands a broad spectrum of programs, often geographically dispersed, that include crisis intervention teams, day treatment programs, substance abuse units, social rehabilitation programs and halfway houses (Bachrach 1983; Turner and TenHoor 1978). Individualized treatment planning often requires that a particular patient participate in two or more specialized programs either simultaneously or in a specified sequence. As a consequence of this specialization, treatment fragmentation has emerged as a significant clinical problem, and continuity of care has been highlighted as a valuable but elusive ingredient of optimal treatment. This paper will describe the dynamic interactions that result when several such programs are united under a common organizational roof. Using a large VA Psychiatry Service as an example, I will outline the hierarchical structure characteristic of such an organization, as well as the persistent pulls toward both integration and fragmentation that influence its operation.

  10. Conceptualizing Teacher Identity as a Complex Dynamic System: The Inner Dynamics of Transformations during a Practicum

    Science.gov (United States)

    Henry, Alastair

    2016-01-01

    Currently, the inner dynamics of teacher identity transformations remain a "black box." Conceptualizing preservice teacher identity as a complex dynamic system, and the notion of "being someone who teaches" in dialogical terms as involving shifts between different teacher voices, the study investigates the dynamical processes…

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

    Science.gov (United States)

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

    2012-01-01

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

  12. Chaos of discrete dynamical systems in complete metric spaces

    International Nuclear Information System (INIS)

    Shi Yuming; Chen Guanrong

    2004-01-01

    This paper is concerned with chaos of discrete dynamical systems in complete metric spaces. Discrete dynamical systems governed by continuous maps in general complete metric spaces are first discussed, and two criteria of chaos are then established. As a special case, two corresponding criteria of chaos for discrete dynamical systems in compact subsets of metric spaces are obtained. These results have extended and improved the existing relevant results of chaos in finite-dimensional Euclidean spaces

  13. University strategy for doctoral training: the Ghent University Doctoral Schools.

    Science.gov (United States)

    Bracke, N; Moens, L

    2010-01-01

    The Doctoral Schools at Ghent University have a three-fold mission: (1) to provide support to doctoral students during their doctoral research, (2) to foster a quality culture in (doctoral) research, (3) to promote the international and social stature and prestige of the doctorate vis-a-vis potential researchers and the potential labour market. The Doctoral Schools offer top-level specialized courses and transferable skills training to doctoral students as part of their doctoral training programme. They establish mechanisms of quality assurance in doctoral research. The Doctoral Schools initialize and support initiatives of internationalization. They also organize information sessions, promotional events and interaction with the labour market, and as such keep a finger on the pulse of external stakeholders.

  14. Dynamic Object Oriented Requirements System (DOORS) System Test Plan

    International Nuclear Information System (INIS)

    JOHNSON, A.L.

    2000-01-01

    The U. S. Department of Energy, Office of River Protection (ORP) will use the Dynamic Object Oriented Requirements System (DOORS) as a tool to assist in identifying, capturing, and maintaining the necessary and sufficient set of requirements for accomplishing the ORP mission. By managing requirements as one integrated set, the ORP will be able to carry out its mission more efficiently and effectively. DOORS is a Commercial-Off-The-Shelf (COTS) requirements management tool. The tool has not been customized for the use of the PIO, at this time

  15. Dimensionless study on dynamics of pressure controlled mechanical ventilation system

    International Nuclear Information System (INIS)

    Shi, Yan; Niu, Jinglong; Cai, Maolin; Xu, Weiqing

    2015-01-01

    Dynamics of mechanical ventilation system can be referred in pulmonary diagnostics and treatments. In this paper, to conveniently grasp the essential characteristics of mechanical ventilation system, a dimensionless model of mechanical ventilation system is presented. For the validation of the mathematical model, a prototype mechanical ventilation system of a lung simulator is proposed. Through the simulation and experimental studies on the dimensionless dynamics of the mechanical ventilation system, firstly, the mathematical model is proved to be authentic and reliable. Secondly, the dimensionless dynamics of the mechanical ventilation system are obtained. Last, the influences of key parameters on the dimensionless dynamics of the mechanical ventilation system are illustrated. The study provides a novel method to study the dynamic of mechanical ventilation system, which can be referred in the respiratory diagnostics and treatment.

  16. Primary care in Brazil, and the Mais Médicos (More Doctors) Program in the Unified Health System: achievements and limits.

    Science.gov (United States)

    Campos, Gastão Wagner de Sousa; Pereira, Nilton

    2016-09-01

    An historical analysis of Brazil's policies in Primary Healthcare, with emphasis on the Family Health Strategy (FHS), and the Mais Médicos Program (PMM). Studies were made of documents and secondary official data, and the bibliography that has been produced on this theme. It was found that primary healthcare has been established and successfully consolidated as an option in healthcare for a great part of the population of Brazil. There have, however, been structural hurdles, which have tended to compromise the effectiveness and sustainability of this policy. It was identified that these obstacles arise principally from insufficient financing and from inefficient modes of planning and management. The Mais Médicos Program has widened care coverage and made the distribution of primary healthcare doctors more equitable, although it has not resolved the structural problems of the public system.

  17. Applied dynamics with applications to multibody and mechatronic systems

    CERN Document Server

    Moon, Francis C

    1998-01-01

    Applied Dynamics provides a modern and thorough examination of dynamics with specific emphasis on physical examples and applications such as: robotic systems, magnetic bearings, aerospace dynamics, and microelectromagnetic machines. Also includes the development of the method of virtual velocities based on the principle of virtual power

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

    National Research Council Canada - National Science Library

    Ya, Nong

    2001-01-01

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

  19. Dynamical critical phenomena in driven-dissipative systems.

    Science.gov (United States)

    Sieberer, L M; Huber, S D; Altman, E; Diehl, S

    2013-05-10

    We explore the nature of the Bose condensation transition in driven open quantum systems, such as exciton-polariton condensates. Using a functional renormalization group approach formulated in the Keldysh framework, we characterize the dynamical critical behavior that governs decoherence and an effective thermalization of the low frequency dynamics. We identify a critical exponent special to the driven system, showing that it defines a new dynamical universality class. Hence critical points in driven systems lie beyond the standard classification of equilibrium dynamical phase transitions. We show how the new critical exponent can be probed in experiments with driven cold atomic systems and exciton-polariton condensates.

  20. Handbook of electrical power system dynamics modeling, stability, and control

    CERN Document Server

    Eremia, Mircea

    2013-01-01

    Complete guidance for understanding electrical power system dynamics and blackouts This handbook offers a comprehensive and up-to-date treatment of power system dynamics. Addressing the full range of topics, from the fundamentals to the latest technologies in modeling, stability, and control, Handbook of Electrical Power System Dynamics provides engineers with hands-on guidance for understanding the phenomena leading to blackouts so they can design the most appropriate solutions for a cost-effective and reliable operation. Focusing on system dynamics, the book details

  1. Competitive assessment of aerospace systems using system dynamics

    Science.gov (United States)

    Pfaender, Jens Holger

    Aircraft design has recently experienced a trend away from performance centric design towards a more balanced approach with increased emphasis on engineering an economically successful system. This approach focuses on bringing forward a comprehensive economic and life-cycle cost analysis. Since the success of any system also depends on many external factors outside of the control of the designer, this traditionally has been modeled as noise affecting the uncertainty of the design. However, this approach is currently lacking a strategic treatment of necessary early decisions affecting the probability of success of a given concept in a dynamic environment. This suggests that the introduction of a dynamic method into a life-cycle cost analysis should allow the analysis of the future attractiveness of such a concept in the presence of uncertainty. One way of addressing this is through the use of a competitive market model. However, existing market models do not focus on the dynamics of the market. Instead, they focus on modeling and predicting market share through logit regression models. The resulting models exhibit relatively poor predictive capabilities. The method proposed here focuses on a top-down approach that integrates a competitive model based on work in the field of system dynamics into the aircraft design process. Demonstrating such integration is one of the primary contributions of this work, which previously has not been demonstrated. This integration is achieved through the use of surrogate models, in this case neural networks. This enabled not only the practical integration of analysis techniques, but also reduced the computational requirements so that interactive exploration as envisioned was actually possible. The example demonstration of this integration is built on the competition in the 250 seat large commercial aircraft market exemplified by the Boeing 767-400ER and the Airbus A330-200. Both aircraft models were calibrated to existing performance

  2. Dynamic systems of regional economy management optimization

    Science.gov (United States)

    Trofimov, S.; Kudzh, S.

    One of the most actual problems of the Russian economic life is a regional economic systems formation. The hierarchy of economic and branch priorities should follow from the general idea of an industrial policy. The matter is that the concept of an industrial policy is defined by the system of priorities mainly incorporated in it. The problem of priorities is not solved yet neither on federal, nor at a regional level. It is necessary to recognize, that a substantiation of this or that variant of priorities - objectively a challenge. Such substantiation can be received with the help of dynamic structural modeling and management technology. At formation of the regional industrial policy program the special attention is given to creation of modern type commercial structures. In regions there are headquarters and branches of many largest corporations, holdings and banks. Besides it, many regional enterprises already became inter-regional or even the transnational companies. In this connection an assistance of transformation of the industrial enterprises and their groups in vertically integrated companies and modern type holdings can become a prominent aspect of an industrial policy. Regional economic structures should be reconstructed gradually on the general model of the world class competitive companies. Assistance to creation of new corporational control systems, the organization of headquarters and the central services work - all this can be included into the sphere of regional administration industrial policy. The special attention should be turned on necessity of development of own system of the corporate structures, capable to provide to the region an independent participation in use of the natural resources and industrial-technological potential, at the stage of a regional industrial policy program formation. Transformation of the industrial enterprises and their groups into modern type vertically-integrated companies and holdings can become one of the major

  3. Ostwald ripening: an approach with dynamical systems

    Directory of Open Access Journals (Sweden)

    Lameiras F.S.

    1999-01-01

    Full Text Available This approach assumes three functions independently acting on a set of microparticles. The first one, w1, concerns re-distribution of mass to decrease the surface energy. The second one, w2, concerns re-distribution of mass to increase the entropy of the microparticle set. The third one, w3, is a further re-distribution of mass that vanishes a microparticle. Once vanished, its mass is distributed among its neighbors. w1 and w3 release energy, whereas w2 absorbs energy. Part of the energy released should be available to sustain w2. The action frequency of w1, w2, and w3, the amount of mass exchanged in each iteraction, the fraction of released energy available to sustain w2, and the size of a vanishing microparticle can be varied. As the dynamical system formed by w1, w2, and w3 act on an initial microparticle set, it is observed an evolution resembling the Ostwald ripening concerning steady-state size distribution and microparticle growth.

  4. Dynamic cell culture system (7-IML-1)

    Science.gov (United States)

    Cogoli, Augusto

    1992-01-01

    This experiment is one of the Biorack experiments being flown on the International Microgravity Laboratory 1 (MIL-1) mission as part of an investigation studying cell proliferation and performance in space. One of the objectives of this investigation is to assess the potential benefits of bioprocessing in space with the ultimate goal of developing a bioreactor for continuous cell cultures in space. This experiment will test the operation of an automated culture chamber that was designed for use in a Bioreactor in space. The device to be tested is called the Dynamic Cell Culture System (DCCS). It is a simple device in which media are renewed or chemicals are injected automatically, by means of osmotic pumps. This experiment uses four Type I/O experiment containers. One DCCS unit, which contains a culture chamber with renewal of medium and a second chamber without a medium supply fits in each container. Two DCCS units are maintained under zero gravity conditions during the on-orbit period. The other two units are maintained under 1 gh conditions in a 1 g centrifuge. The schedule for incubator transfer is given.

  5. Glassy dynamics in randomly pinned particle systems

    Science.gov (United States)

    Phan, Anh; Schweizer, Kenneth

    We generalize the force-level, microscopic Elastically Collective Nonlinear Langevin Equation theory of activated relaxation in bulk hard sphere and thermal liquids to address the role of internal quenched disorder. So-called neutral confinement is considered where a subset of particles are randomly pinned and there is no change of equilibrium pair structure. As the pinned fraction grows, the cage scale dynamical constraints are intensified, resulting in the mobile particles becoming more localized, a larger glassy shear modulus, and an enhanced cage scale barrier. However, based on an approximate analysis of how quenched disorder modifies collective elastic field fluctuations, random pinning is predicted to effectively screen or localize the strain field associated with the longer range elastic component of the activation barrier, leading to an overall reduction of it with pinning fraction. The different response of the cage and elastic barriers to quenched disorder results in subtle predictions for how the alpha relaxation time varies with pinning fraction and system volume fraction. A semi-quantitative comparison with recent simulations of a pinned-mobile water model are consistent with the theory. Predictions are made for thermal molecular liquids.

  6. [Murder of the doctor].

    Science.gov (United States)

    Lorettu, Liliana; Falchi, Lorenzo; Nivoli, Fabrizia L; Milia, Paolo; Nivoli, Giancarlo; Nivoli, Alessandra M

    2015-01-01

    To examine possible risk factors for the doctor to be killed by the patient in the clinical practice by examining a series of murders that involved physicians. This aim has been achieved through a retrospective review on clinical cases of doctors killed by patients within the period between 1988 and 2013, in Italy. In this period 18 Italian doctors have been killed in the workplace, with a rate of 0.3/100,000. In 7 cases, the murder resulted in the context of doctor-dissatisfaction; in 7 cases the murder was committed by a psychiatric patient; 1 case in the context of a stalking; 3 cases occurred in a workplace which was not safe enough. Four categories of at-risk contexts have been identified. One category includes a murder in the context of a doctor-dissatisfaction, perceived by patient. The second category concerns murders committed by patients suffering from mental illness. A third category includes homicides in a workplace which is not safe. The last category comprises the murder in the context of stalking. These categories identify specific dangerous situations for physicians, in which are highlighted elements that have played a crucial role in the murder and for which special precautions are suggested preventive.

  7. The dynamics of general developmental mechanisms : From Piaget and Vygotsky to dynamic systems models

    NARCIS (Netherlands)

    van Geert, P

    Dynamic systems theory conceives of development as a self-organizational process. Both complexity and order emerge as a product of elementary principles of interaction between components involved in the developmental process. This article presents a dynamic systems model based on a general dual

  8. Second Language Developmental Dynamics: How Dynamic Systems Theory Accounts for Issues in Second Language Learning

    Science.gov (United States)

    Rosmawati

    2014-01-01

    Dynamic systems theory (DST) is presented in this article as a suitable approach to research the acquisition of second language (L2) because of its close alignment with the process of second language learning. Through a process of identifying and comparing the characteristics of a dynamic system with the process of L2 learning, this article…

  9. Dynamic management of integrated residential energy systems

    Science.gov (United States)

    Muratori, Matteo

    dissertation presents a bottom-up highly resolved model of a generic residential energy eco-system in the United States. The model is able to capture the entire energy footprint of an individual household, to include all appliances, space conditioning systems, in-home charging of plug-in electric vehicles, and any other energy needs, viewing residential and transportation energy needs as an integrated continuum. The residential energy eco-system model is based on a novel bottom-up approach that quantifies consumer energy use behavior. The incorporation of stochastic consumer behaviors allows capturing the electricity consumption of each residential specific end-use, providing an accurate estimation of the actual amount of available controllable resources, and for a better understanding of the potential of residential demand response programs. A dynamic energy management framework is then proposed to manage electricity consumption inside each residential energy eco-system. Objective of the dynamic energy management framework is to optimize the scheduling of all the controllable appliances and in-home charging of plug-in electric vehicles to minimize cost. Such an automated energy management framework is used to simulate residential demand response programs, and evaluate their impact on the electric power infrastructure. For instance, time-varying electricity pricing might lead to synchronization of the individual residential demands, creating pronounced rebound peaks in the aggregate demand that are higher and steeper than the original demand peaks that the time-varying electricity pricing structure intended to eliminate. The modeling tools developed in this study can serve as a virtual laboratory for investigating fundamental economic and policy-related questions regarding the interplay of individual consumers with energy use. The models developed allow for evaluating the impact of different energy policies, technology adoption, and electricity price structures on the total

  10. Advances in analysis and control of timedelayed dynamical systems

    CERN Document Server

    Sun, Jianqiao

    2013-01-01

    Analysis and control of timedelayed systems have been applied in a wide range of applications, ranging from mechanical, control, economic, to biological systems. Over the years, there has been a steady stream of interest in timedelayed dynamic systems, this book takes a snap shot of recent research from the world leading experts in analysis and control of dynamic systems with time delay to provide a bird's eye view of its development. The topics covered in this book include solution methods, stability analysis and control of periodic dynamic systems with time delay, bifurcations, stochastic dy

  11. PREFACE: Dynamics of low-dimensional systems Dynamics of low-dimensional systems

    Science.gov (United States)

    Bernasconi, M.; Miret-Artés, S.; Toennies, J. P.

    2012-03-01

    With the development of techniques for high-resolution inelastic helium atom scattering (HAS), electron scattering (EELS) and neutron spin echo spectroscopy, it has become possible, within approximately the last thirty years, to measure the dispersion curves of surface phonons in insulators, semiconductors and metals. In recent years, the advent of new experimental techniques such as 3He spin-echo spectroscopy, scanning inelastic electron tunnel spectroscopy, inelastic x-ray scattering spectroscopy and inelastic photoemission have extended surface phonon spectroscopy to a variety of systems. These include ultra-thin metal films, adsorbates at surface and elementary processes where surface phonons play an important role. Other important directions have been actively pursued in the past decade: the dynamics of stepped surfaces and clusters grown on metal surfaces, due to their relevance in many dynamical and chemical processes at surfaces, including heterogeneous catalysis; clusters; diffusion etc. The role of surface effects in these processes has been conjectured since the early days of surface dynamics, although only now is the availability of ab initio approaches providing those conjectures with a microscopic basis. Last but not least, the investigation of non-adiabatic effects, originating for instance from the hybridization (avoided crossing) of the surface phonons branches with the quasi 1D electron-hole excitation branch, is also a challenging new direction. Furthermore, other elementary oscillations such as surface plasmons are being actively investigated. The aforementioned experimental breakthroughs have been accompanied by advances in the theoretical study of atom-surface interaction. In particular, in the past decade first principles calculations based on density functional perturbation theory have boosted the theoretical study of the dynamics of low-dimensional systems. Phonon dispersion relations of clean surfaces, the dynamics of adsorbates, and the

  12. Dynamical Systems and Jung, with a Note on Language

    Science.gov (United States)

    Barrett, Bruce E.

    2011-01-01

    Comments on the original article "Rethinking intractable conflict: The perspective of dynamical systems," by R. R. Vallacher, P. T. Coleman, A. Nowak, and L. Bui-Wrzosinska. Vallacher et al presented an intriguing description of dynamical systems theory as applied to the understanding of intractable conflicts ranging from the intrapsychic to the…

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

    CERN Document Server

    Krause, Ulrich

    2015-01-01

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

  14. Making System Dynamics Cool IV : Teaching & Testing with Cases & Quizzes

    NARCIS (Netherlands)

    Pruyt, E.

    2012-01-01

    This follow-up paper presents cases and multiple choice questions for teaching and testing System Dynamics modeling. These cases and multiple choice questions were developed and used between January 2012 and April 2012 a large System Dynamics course (250+ 2nd year BSc and 40+ MSc students per year)

  15. Making System Dynamics Cool? Using Hot Testing & Teaching Cases

    NARCIS (Netherlands)

    Pruyt, E.

    2009-01-01

    This paper deals with the use of ‘hot’ real-world cases for both testing and teaching purposes such as in the Introductory System Dynamics course at Delft University of Technology in the Netherlands. The paper starts with a brief overview of the System Dynamics curriculum. Then the problem-oriented

  16. Making System Dynamics Cool III : New Hot Teaching & Testing Cases

    NARCIS (Netherlands)

    Pruyt, E.

    2011-01-01

    This follow-up paper presents seven actual cases for testing and teaching System Dynamics developed and used between January 2010 and January 2011 for one of the largest System Dynamics courses (250+ students per year) at Delft University of Technology in the Netherlands. The cases presented in this

  17. System Dynamics in Medical Education: A Tool for Life

    Science.gov (United States)

    Rubin, David M.; Richards, Christopher L.; Keene, Penelope A. C.; Paiker, Janice E.; Gray, A. Rosemary T.; Herron, Robyn F. R.; Russell, Megan J.; Wigdorowitz, Brian

    2012-01-01

    A course in system dynamics has been included in the first year of our university's six-year medical curriculum. System Dynamics is a discipline that facilitates the modelling, simulation and analysis of a wide range of problems in terms of two fundamental concepts viz. rates and levels. Many topics encountered in the medical school curriculum,…

  18. Understanding Digital Learning from the Perspective of Systems Dynamics

    Science.gov (United States)

    Kok, Ayse

    2009-01-01

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

  19. On the Connectedness of Attractors for Dynamical Systems

    Science.gov (United States)

    Gobbino, Massimo; Sardella, Mirko

    1997-01-01

    For a dynamical system on a connected metric spaceX, the global attractor (when it exists) is connected provided that either the semigroup is time-continuous orXis locally connected. Moreover, there exists an example of a dynamical system on a connected metric space which admits a disconnected global attractor.

  20. Energy conservation in molecular dynamics simulations of classical systems

    DEFF Research Database (Denmark)

    Toxværd, Søren; Heilmann, Ole; Dyre, J. C.

    2012-01-01

    Classical Newtonian dynamics is analytic and the energy of an isolated system is conserved. The energy of such a system, obtained by the discrete “Verlet” algorithm commonly used in molecular dynamics simulations, fluctuates but is conserved in the mean. This is explained by the existence...

  1. Dynamics of slow and fast systems on complex networks

    Indian Academy of Sciences (India)

    In this study, we present the emergent collective behavior in a network of nonlinear dynamical systems, where the heterogeneity arises only from the difference in the time scales of nodal dynamics. To make this a spe- cific feature and bring out effects of time-scale mismatch of connected systems, we consider an otherwise ...

  2. Modeling Adaptive Dynamical Systems to Analyze Eating Regulation Disorders

    NARCIS (Netherlands)

    Bosse, T.; Delfos, M.F.; Jonker, C.M.; Treur, J.

    2006-01-01

    To analyze the disorders of their patients, psychotherapists often have to get insight in adaptive dynamical systems. Analysis of dynamical systems usually is performed using mathematical techniques. Such an analysis is not precisely the type of reasoning performed in psychotherapy practice. In this

  3. Implementation of Keystroke Dynamics for Authentication in Computer Systems

    Directory of Open Access Journals (Sweden)

    S. V. Skuratov

    2010-06-01

    Full Text Available Implementation of keystroke dynamics in multifactor authentication systems is described in the article. Original access control system based on totality of matchers is presented. Testing results and useful recommendations are also adduced.

  4. Simulation of dynamic systems with Matlab and Simulink

    CERN Document Server

    Klee, Harold

    2011-01-01

    Mathematical ModelingDerivation of a Mathematical ModelDifference EquationsFirst Look at Discrete-Time SystemsCase Study: Population Dynamics (Single Species)Continuous-Time SystemsFirst-Order SystemsSecond-Order SystemsSimulation DiagramsHigher-Order SystemsState VariablesNonlinear SystemsCase Study: Submarine Depth Control SystemElementary Numerical IntegrationDiscrete-Time System Approximation of a Continuous-

  5. Conceptualising Doctoral Writing as an Affective-political Practice

    Directory of Open Access Journals (Sweden)

    James Burford

    2017-03-01

    Full Text Available Aim/Purpose: This article offers a conceptual summary and critique of existing literature on doctoral writing and emotion. The article seeks to intervene in current debates about doctoral writing by re-positioning it as an affective-political practice Background: Over recent decades public interest in the doctorate has expanded as it has become re-framed as a key component of national success in the global knowledge economy. It is within this context that the practice of doctoral writing has crystallised as an object of interest. While researchers have examined the increased regulation, surveillance, and intensification of doctoral writing, often this work is motivated to develop pedagogies that support students to meet these new expectations. At this point, there has been limited attention to what broad changes to the meanings and practices of doctoral writing feel like for students. Methodology: The paper offers a conceptual review that examines the ways in which doctoral writing tends to be understood. A review of literature in the areas of doctoral writing, doctoral emotion, and critical studies of academic labour was undertaken in order to produce a more comprehensive understanding of the political and emotional dynamics of doctoral writing. Contribution: It is intended that this conceptual research paper help researchers attend to the emotional context of doctoral writing in the current university context. Critical studies of academic work and life are identified as a possible platform for the development of future doctoral education research, and the conceptual tool of “affective-politics” is advanced as a novel frame for approaching doctoral writing research.

  6. Theory of hybrid dynamical systems and its applications to biological and medical systems.

    Science.gov (United States)

    Aihara, Kazuyuki; Suzuki, Hideyuki

    2010-11-13

    In this introductory article, we survey the contents of this Theme Issue. This Theme Issue deals with a fertile region of hybrid dynamical systems that are characterized by the coexistence of continuous and discrete dynamics. It is now well known that there exist many hybrid dynamical systems with discontinuities such as impact, switching, friction and sliding. The first aim of this Issue is to discuss recent developments in understanding nonlinear dynamics of hybrid dynamical systems in the two main theoretical fields of dynamical systems theory and control systems theory. A combined study of the hybrid systems dynamics in the two theoretical fields might contribute to a more comprehensive understanding of hybrid dynamical systems. In addition, mathematical modelling by hybrid dynamical systems is particularly important for understanding the nonlinear dynamics of biological and medical systems as they have many discontinuities such as threshold-triggered firing in neurons, on-off switching of gene expression by a transcription factor, division in cells and certain types of chronotherapy for prostate cancer. Hence, the second aim is to discuss recent applications of hybrid dynamical systems in biology and medicine. Thus, this Issue is not only general to serve as a survey of recent progress in hybrid systems theory but also specific to introduce interesting and stimulating applications of hybrid systems in biology and medicine. As the introduction to the topics in this Theme Issue, we provide a brief history of nonlinear dynamics and mathematical modelling, different mathematical models of hybrid dynamical systems, the relationship between dynamical systems theory and control systems theory, examples of complex behaviour in a simple neuron model and its variants, applications of hybrid dynamical systems in biology and medicine as a road map of articles in this Theme Issue and future directions of hybrid systems modelling.

  7. Impulsive and hybrid dynamical systems stability, dissipativity, and control

    CERN Document Server

    Haddad, Wassim M; Nersesov, Sergey G

    2014-01-01

    This book develops a general analysis and synthesis framework for impulsive and hybrid dynamical systems. Such a framework is imperative for modern complex engineering systems that involve interacting continuous-time and discrete-time dynamics with multiple modes of operation that place stringent demands on controller design and require implementation of increasing complexity--whether advanced high-performance tactical fighter aircraft and space vehicles, variable-cycle gas turbine engines, or air and ground transportation systems. Impulsive and Hybrid Dynamical Systems goes beyond similar

  8. Talking to Your Doctor

    Medline Plus

    Full Text Available ... You can play an active role in your health care by talking to your doctor. Clear and honest ... Español Complementary and Integrative Health Talking With Your Health Care Providers About Complementary Health Approaches , National Center for ...

  9. Talking to Your Doctor

    Medline Plus

    Full Text Available ... Employee Intranet Staff Directory En Español Site Menu Home Health Information Health Info Lines Health Services Locator HealthCare.gov NIH Clinical Research Trials and You Talking to Your Doctor Science Education Resources Community Resources Clear Health A–Z Publications ...

  10. Talking to Your Doctor

    Medline Plus

    Full Text Available ... Info Lines Health Services Locator HealthCare.gov NIH Clinical Research Trials and You Talking to Your Doctor Science ... Labs & Clinics Training Opportunities Library Resources Research Resources Clinical Research Resources Safety, Regulation and Guidance More » Quick Links ...

  11. The Doctor and Society*

    African Journals Online (AJOL)

    The doctor, no less than any other scientist, is a member of society. His situation, however, is unique, inasmuch as in an age of technocracy he must remain human. Despite the pressure of his own discipline he should be an edu- cated person in the general meaning of the word. The necessary attributes of this state are ...

  12. Talking to Your Doctor

    Medline Plus

    Full Text Available ... Staff Directory En Español Site Menu Home Health Information Health Info Lines Health Services Locator HealthCare.gov NIH Clinical Research Trials and You Talking to Your Doctor Science Education Resources Community Resources Clear Health A–Z ...

  13. Talking to Your Doctor

    Medline Plus

    Full Text Available ... Info Lines Health Services Locator HealthCare.gov NIH Clinical Research Trials and You Talking to Your Doctor Science Education ... Labs & Clinics Training Opportunities Library Resources Research Resources Clinical Research Resources Safety, Regulation and Guidance More ... Blueprint for Neuroscience Research ...

  14. Talking to Your Doctor

    Medline Plus

    Full Text Available ... Services Search the NIH Website NIH Employee Intranet Staff Directory En Español Site Menu Home Health Information Health Info Lines Health Services Locator HealthCare.gov NIH Clinical Research Trials and You Talking to Your Doctor Science Education ...

  15. Providing protection for doctors.

    Science.gov (United States)

    Hegan, T

    2003-03-01

    Over the last decade the number of negligence cases brought against doctors, dentists and other healthcare professional has increased significantly in many countries around the world. In addition, the proliferation of the pathways of accountability in many countries means that doctors are feeling undervalued and vulnerable and are therefore seeking assistance and protection more than ever. The effect of a claim or complaint on a doctor can be devastating both personally and professionally. The relationship with the patient is damaged and an increase in defensive practice ultimately causes an increase in healthcare costs. Patient expectations have increased. Patients are more knowledgeable than they were five years ago and the demands on the professions are increasing daily. Unfortunately because of the long delays that are seen between an incident and a claim it is very difficult to predict what reserves are required in the future. We have seen a number of organisations pull out of the business over the last year and it highlights the importance of having an understanding of the needs of the professions and the ability to track trends in litigation in order to set appropriate subscription rates. Doctors and other healthcare professionals require more than just financial protection. They need support from their colleagues and assistance from experienced lawyers in order to help restore their confidence and ensure that they can continue to practice for the benefit of their patients in the future.

  16. Fourth Doctoral Student Assembly

    CERN Multimedia

    Ingrid Haug

    2016-01-01

    On 10 May, over 130 PhD students and their supervisors, from both CERN and partner universities, gathered for the 4th Doctoral Student Assembly in the Council Chamber.   The assembly was followed by a poster session, at which eighteen doctoral students presented the outcome of their scientific work. The CERN Doctoral Student Programme currently hosts just over 200 students in applied physics, engineering, computing and science communication/education. The programme has been in place since 1985. It enables students to do their research at CERN for a maximum of three years and to work on a PhD thesis, which they defend at their University. The programme is steered by the TSC committee, which holds two selection committees per year, in June and December. The Doctoral Student Assembly was opened by the Director-General, Fabiola Gianotti, who stressed the importance of the programme in the scientific environment at CERN, emphasising that there is no more rewarding activity than lear...

  17. Dynamic screening and electron dynamics in low-dimensional metal systems

    International Nuclear Information System (INIS)

    Silkin, V.M.; Quijada, M.; Vergniory, M.G.; Alducin, M.; Borisov, A.G.; Diez Muino, R.; Juaristi, J.I.; Sanchez-Portal, D.; Chulkov, E.V.; Echenique, P.M.

    2007-01-01

    Recent advances in the theoretical description of dynamic screening and electron dynamics in metallic media are reviewed. The time-dependent building-up of screening in different situations is addressed. Perturbative and non-perturbative theories are used to study electron dynamics in low-dimensional systems, such as metal clusters, image states, surface states and quantum wells. Modification of the electronic lifetimes due to confinement effects is analyzed as well

  18. Generic solar photovoltaic system dynamic simulation model specification

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, Abraham [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Behnke, Michael Robert [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Elliott, Ryan Thomas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2013-10-01

    This document is intended to serve as a specification for generic solar photovoltaic (PV) system positive-sequence dynamic models to be implemented by software developers and approved by the WECC MVWG for use in bulk system dynamic simulations in accordance with NERC MOD standards. Two specific dynamic models are included in the scope of this document. The first, a Central Station PV System model, is intended to capture the most important dynamic characteristics of large scale (> 10 MW) PV systems with a central Point of Interconnection (POI) at the transmission level. The second, a Distributed PV System model, is intended to represent an aggregation of smaller, distribution-connected systems that comprise a portion of a composite load that might be modeled at a transmission load bus.

  19. Vibroimpact Dynamics of a Tethered Satellite System

    Directory of Open Access Journals (Sweden)

    B. S. Yu

    2017-01-01

    Full Text Available This paper presents the vibroimpact dynamics of an in-plane tethered subsatellite caused by sudden braking during deployment or retrieval. The full dynamics of the subsatellite are composed of its free-flight and the instantaneous impacts. At the moment of impact, the reflective angle of the subsatellite is envisioned to be equal to its incident angle such that the impact law is obtained. Then, the stability of the periodic vibroimpacts is analyzed using the composite Poincaré map. Further, the vibroimpact responses that do not exceed a specified region are numerically determined via the cell mapping method.

  20. Navigating towards Decoupled Aquaponic Systems: A System Dynamics Design Approach

    Directory of Open Access Journals (Sweden)

    Simon Goddek

    2016-07-01

    Full Text Available The classical working principle of aquaponics is to provide nutrient-rich aquacultural water to a hydroponic plant culture unit, which in turn depurates the water that is returned to the aquaculture tanks. A known drawback is that a compromise away from optimal growing conditions for plants and fish must be achieved to produce both crops and fish in the same environmental conditions. The objective of this study was to develop a theoretical concept of a decoupled aquaponic system (DAPS, and predict water, nutrient (N and P, fish, sludge, and plant levels. This has been approached by developing a dynamic aquaponic system model, using inputs from data found in literature covering the fields of aquaculture, hydroponics, and sludge treatment. The outputs from the model showed the dependency of aquacultural water quality on the hydroponic evapotranspiration rate. This result can be explained by the fact that DAPS is based on one-way flows. These one-way flows results in accumulations of remineralized nutrients in the hydroponic component ensuring optimal conditions for the plants. The study also suggests to size the cultivation area based on P availability in the hydroponic component as P is an exhaustible resource and has been identified one of the main limiting factors for plant growth.

  1. Research on Collaborative Knowledge Innovation Based on System Dynamics

    OpenAIRE

    Wang Xiuhong

    2012-01-01

    Constructing the rational knowledge network is an effective means of cooperative innovation organization. But collaborative innovation organization system is relatively complicated, and knowledge itself is latent and unexpected, knowledge network is not comprehensive and accurate. This paper analyzes deeply knowledge network of organization cooperative innovation, and builds a system dynamics model about knowledge network of collaborative innovation by using the system dynamics model and func...

  2. Dynamics and Thermodynamics of Many Particle Cold Atom Systems

    Science.gov (United States)

    2016-05-05

    AFRL-AFOSR-VA-TR-2016-0219 Dynamics and Thermodynamics of Many Particle Cold Atom Systems Anatoli Polkovnikov TRUSTEES OF BOSTON UNIVERSITY Final...TITLE AND SUBTITLE Dynamics and Thermodynamics of Many Particle Cold Atom Systems 5a. CONTRACT NUMBER 5b. GRANT NUMBER FA9550-13-1-0039 5c. PROGRAM...largely to cold atoms . All goals stated in the proposal were addressed. In addition two conceptually new ideas have emerged (Floquet systems and

  3. On the Theory of Nonlinear Dynamics and its Applications in Vehicle Systems Dynamics

    DEFF Research Database (Denmark)

    True, Hans

    1999-01-01

    We present a brief outline of nonlinear dynamics and its applications to vehicle systems dynamics problems. The concept of a phase space is introduced in order to illustrate the dynamics of nonlinear systems in a way that is easy to perceive. Various equilibrium states are defined...... of nonlinear dynamics in vehicle simulations is discussed, and it is argued that it is necessary to know the equilibrium states of the full nonlinear system before the simulation calculations are performed......., and the important case of multiple equilibrium states and their dependence on a parameter is discussed. It is argued that the analysis of nonlinear dynamic problems always should start with an analysis of the equilibrium states of the full nonlinear problem whereby great care must be taken in the choice...

  4. Quantum dynamics in open quantum-classical systems.

    Science.gov (United States)

    Kapral, Raymond

    2015-02-25

    Often quantum systems are not isolated and interactions with their environments must be taken into account. In such open quantum systems these environmental interactions can lead to decoherence and dissipation, which have a marked influence on the properties of the quantum system. In many instances the environment is well-approximated by classical mechanics, so that one is led to consider the dynamics of open quantum-classical systems. Since a full quantum dynamical description of large many-body systems is not currently feasible, mixed quantum-classical methods can provide accurate and computationally tractable ways to follow the dynamics of both the system and its environment. This review focuses on quantum-classical Liouville dynamics, one of several quantum-classical descriptions, and discusses the problems that arise when one attempts to combine quantum and classical mechanics, coherence and decoherence in quantum-classical systems, nonadiabatic dynamics, surface-hopping and mean-field theories and their relation to quantum-classical Liouville dynamics, as well as methods for simulating the dynamics.

  5. From the doctor's workshop to the iron cage? Evolving modes of physician control in US health systems.

    Science.gov (United States)

    Kitchener, Martin; Caronna, Carol A; Shortell, Stephen M

    2005-03-01

    As national health systems pursue the common goals of containing expenditure growth and improving quality, many have sought to replace autonomous modes (systems) of physician control that rely on initial professional training and subsequent peer review. A common approach has involved extending bureaucratic modes of physician control that employ techniques such as hierarchical coordination and salaried positions. This paper applies concepts from studies of professional work to frame an empirical analysis of emergent bureaucratic modes of physician control in US hospital-based systems. Conceptually, we draw from recent studies to update Scott's (Health Services Res. 17(3) (1982) 213) typology to specify three bureaucratic modes of physician control: heteronomous, conjoint, and custodial. Empirically, we use case study evidence from eight US hospital-based systems to illustrate the heterogeneity of bureaucratic modes of physician control that span each of the ideal types. The findings indicate that some influential analysts perpetuate a caricature of bureaucratic organization which underplays its capacity to provide multiple modes of physician control that maintain professional autonomy over the content of work, and present opportunities for aligning practice with social goals.

  6. Satisfaction Levels and Factors Influencing Satisfaction With Use of a Social App for Neonatal and Pediatric Patient Transfer Information Systems: A Questionnaire Study Among Doctors.

    Science.gov (United States)

    Choi, Iee; Kim, Jin Kyu; Kim, Sun Jun; Cho, Soo Chul; Kim, Il Nyeo

    2016-08-04

    The treatment of neonatal and pediatric patients is limited to certain medical institutions depending on treatment difficulty. Effective patient transfers are necessary in situations where there are limited medical resources. In South Korea, the government has made a considerable effort to establish patient transfer systems using various means, such as websites, telephone, and so forth. However, in reality, the effort has not yet been effective. In this study, we ran a patient transfer information system using a social app for effective patient transfer. We analyzed the results, satisfaction levels, and the factors influencing satisfaction. Naver Band is a social app and mobile community application which in Korea is more popular than Facebook. It facilitates group communication. Using Naver Band, two systems were created: one by the Neonatal Intensive Care Unit and the other by the Department of Pediatrics at Chonbuk National University Children's Hospital, South Korea. The information necessary for patient transfers was provided to participating obstetricians (n=51) and pediatricians (n=90). We conducted a survey to evaluate the systems and reviewed the results retrospectively. The number of patients transferred was reported to increase by 65% (26/40) obstetricians and 40% (23/57) pediatricians. The time taken for transfers was reported to decrease by 72% (29/40) obstetricians and 59% (34/57) pediatricians. Satisfaction was indicated by 83% (33/40) obstetricians and 89% (51/57) pediatricians. Regarding factors influencing satisfaction, the obstetricians reported communication with doctors in charge (P=.03) and time reduction during transfers (P=.02), whereas the pediatricians indicated review of the diagnosis and treatment of transferred patients (P=.01) and the time reduction during transfers (P=.007). The users were highly satisfied and different users indicated different factors of satisfaction. This finding implies that users' requirements should be

  7. Validating specifications of dynamic systems using automated reasoning techniques

    NARCIS (Netherlands)

    Feenstra, Remco; Bioch, J.C.; Wieringa, Roelf J.; Tan, Y.H

    In this paper, we propose a new approach to validating formal specifications of observable behavior of discrete dynamic systems. By observable behavior we mean system behavior as observed by users or other systems in the environment of the system. Validation of a formal specification of an informal

  8. Solar Dynamic Power System Stability Analysis and Control

    Science.gov (United States)

    Momoh, James A.; Wang, Yanchun

    1996-01-01

    The objective of this research is to conduct dynamic analysis, control design, and control performance test of solar power system. Solar power system consists of generation system and distribution network system. A bench mark system is used in this research, which includes a generator with excitation system and governor, an ac/dc converter, six DDCU's and forty-eight loads. A detailed model is used for modeling generator. Excitation system is represented by a third order model. DDCU is represented by a seventh order system. The load is modeled by the combination of constant power and constant impedance. Eigen-analysis and eigen-sensitivity analysis are used for system dynamic analysis. The effects of excitation system, governor, ac/dc converter control, and the type of load on system stability are discussed. In order to improve system transient stability, nonlinear ac/dc converter control is introduced. The direct linearization method is used for control design. The dynamic analysis results show that these controls affect system stability in different ways. The parameter coordination of controllers are recommended based on the dynamic analysis. It is concluded from the present studies that system stability is improved by the coordination of control parameters and the nonlinear ac/dc converter control stabilize system oscillation caused by the load change and system fault efficiently.

  9. Steering Dynamics in the Dutch Education System

    Science.gov (United States)

    Waslander, Sietske; Hooge, Edith; Drewes, Tineke

    2016-01-01

    Based on detailed empirical analyses, we paint a layered picture of emerging steering dynamics. Inspired by Foucault, we put the focus on roles stakeholders define both for themselves and others, how they give sense to policy, how they work together in policy elaboration and implementation, and the subtle and sometimes deceitful function of soft…

  10. Dynamical systems of proper characteristic 0

    International Nuclear Information System (INIS)

    Ahmad, K.H.; Hamoui, A.

    1991-07-01

    Flows with orbits of proper characteristics 0 exhibit recurrent behaviour, a feature of basic importance in the description of their dynamics. Here, we analyze flows with such orbits relating them with recurrent flows and with flows that exhibit orbital, Poisson or Lagrange stability. (author). 11 refs

  11. Stability of interconnected dynamical systems described on Banach spaces

    Science.gov (United States)

    Rasmussen, R. D.; Michel, A. N.

    1976-01-01

    New stability results for a large class of interconnected dynamical systems (also called composite systems or large scale systems) described on Banach spaces are established. In the present approach, the objective is always the same: to analyze large scale systems in terms of their lower order and simpler subsystems and in terms of their interconnecting structure. The present results provide a systematic procedure of analyzing hybrid dynamical systems (i.e., systems that are described by a mixture of different types of equations). To demonstrate the method of analysis advanced, two specific examples are considered.

  12. Mathematical Modeling and Dimension Reduction in Dynamical Systems

    DEFF Research Database (Denmark)

    Elmegård, Michael

    Processes that change in time are in mathematics typically described by differential equations. These may be applied to model everything from weather forecasting, brain patterns, reaction kinetics, water waves, finance, social dynamics, structural dynamics and electrodynamics to name only a few....... These systems are generically nonlinear and the studies of them often become enormously complex. The framework in which such systems are best understood is via the theory of dynamical systems, where the critical behavior is systematically analyzed by performing bifurcation theory. In that context the current...

  13. Bridging developmental systems theory and evolutionary psychology using dynamic optimization.

    Science.gov (United States)

    Frankenhuis, Willem E; Panchanathan, Karthik; Clark Barrett, H

    2013-07-01

    Interactions between evolutionary psychologists and developmental systems theorists have been largely antagonistic. This is unfortunate because potential synergies between the two approaches remain unexplored. This article presents a method that may help to bridge the divide, and that has proven fruitful in biology: dynamic optimization. Dynamic optimization integrates developmental systems theorists' focus on dynamics and contingency with the 'design stance' of evolutionary psychology. It provides a theoretical framework as well as a set of tools for exploring the properties of developmental systems that natural selection might favor, given particular evolutionary ecologies. We also discuss limitations of the approach. © 2013 Blackwell Publishing Ltd.

  14. Rapid Prototyping of Social Group Dynamics in Multiagent Systems

    DEFF Research Database (Denmark)

    Rehm, Matthias; Endrass, Birgit

    2009-01-01

    In this article we present an engineering approach for the integration of social group dynamics in the behavior modeling of multiagent systems. To this end, a toolbox was created that brings together several theories from the social sciences, each focusing on different aspects of group dynamics. ...

  15. XXIII International Conference on Nonlinear Dynamics of Electronic Systems

    CERN Document Server

    Stoop, Ruedi; Stramaglia, Sebastiano

    2017-01-01

    This book collects contributions to the XXIII international conference “Nonlinear dynamics of electronic systems”. Topics range from non-linearity in electronic circuits to synchronisation effects in complex networks to biological systems, neural dynamics and the complex organisation of the brain. Resting on a solid mathematical basis, these investigations address highly interdisciplinary problems in physics, engineering, biology and biochemistry.

  16. Bifurcation and chaos in simple jerk dynamical systems

    Indian Academy of Sciences (India)

    - ferential equation, named as jerk equation, represents an interesting sub-class of dynam- ical systems that can exhibit many major features of the regular and chaotic motion. In this paper, we investigate the global dynamics of a special family ...

  17. Dynamic Observers for Fault Diagnosis of Timed Systems

    OpenAIRE

    Cassez, Franck

    2010-01-01

    In this paper we extend the work on \\emph{dynamic ob\\-servers} for fault diagnosis to timed automata. We study sensor minimization problems with static observers and then address the problem of computing the most permissive dynamic observer for a system given by a timed automaton.

  18. Fractal differential equations and fractal-time dynamical systems

    Indian Academy of Sciences (India)

    equations. Hence the latter can be used to model fractal-time processes or sublinear dynamical systems. ... for the treatment of diffusion, heat conduction, waves, etc., on self-similar fractals [25–28]. Harmonic ... differential equations offer possibilities of modeling dynamical behaviours naturally for which ordinary differential ...

  19. The haemtrack home therapy reporting system: Design, implementation, strengths and weaknesses: A report from UK Haemophilia Centre Doctors Organisation.

    Science.gov (United States)

    Hay, C R M; Xiang, H; Scott, M; Collins, P W; Liesner, R; Dolan, G; Hollingsworth, R

    2017-09-01

    Haemtrack is an electronic home treatment diary for patients with inherited bleeding disorders, introduced in 2008. It aimed to improve the timeliness and completeness of patient-reported treatment records, to facilitate analysis of treatment and outcome trends. The system is easy to use, responsive and accessible. The software uses Microsoft technologies with a SQL Server database and an ASP.net website front-end, running on personal computers, android and I-phones. Haemtrack interfaces with the UK Haemophilia Centre Information System and the National Haemophilia Database (NHD). Data are validated locally by Haemophilia Centres and centrally by NHD. Data collected include as follows: treatment brand, dose and batch number, time/date of bleed onset and drug administration, reasons for treatment (prophylaxis, bleed, follow-up), bleed site, severity, pain-score and outcome. Haemtrack was used by 90% of haemophilia treatment centres (HTCs) in 2015, registering 2683 patients using home therapy of whom 1923 used Haemtrack, entering >17 000 treatments per month. This included 68% of all UK patients with severe haemophilia A. Reporting compliance varied and 55% of patients reported ≥75% of potential usage. Centres had a median 78% compliance overall. A strategy for progressively improving compliance is in place. Age distribution and treatment intensity were similar in Haemtrack users/non-users with severe haemophilia treated prophylactically. The Haemtrack system is a valuable tool that may improve treatment compliance and optimize treatment regimen. Analysis of national treatment trends and large-scale longitudinal, within-patient analysis of changes in regimen and/or product will provide valuable insights that will guide future clinical practice. © 2017 John Wiley & Sons Ltd.

  20. Analysis and control of complex dynamical systems robust bifurcation, dynamic attractors, and network complexity

    CERN Document Server

    Imura, Jun-ichi; Ueta, Tetsushi

    2015-01-01

    This book is the first to report on theoretical breakthroughs on control of complex dynamical systems developed by collaborative researchers in the two fields of dynamical systems theory and control theory. As well, its basic point of view is of three kinds of complexity: bifurcation phenomena subject to model uncertainty, complex behavior including periodic/quasi-periodic orbits as well as chaotic orbits, and network complexity emerging from dynamical interactions between subsystems. Analysis and Control of Complex Dynamical Systems offers a valuable resource for mathematicians, physicists, and biophysicists, as well as for researchers in nonlinear science and control engineering, allowing them to develop a better fundamental understanding of the analysis and control synthesis of such complex systems.

  1. The investigation of tethered satellite system dynamics

    Science.gov (United States)

    Lorenzini, E. C.

    1986-01-01

    The analysis of the rotational dynamics of the satellite was focused on the rotational amplitude increase of the satellite, with respect to the tether, during retrieval. The dependence of the rotational amplitude upon the tether tension variation to the power 1/4 was thoroughly investigated. The damping of rotational oscillations achievable by reel control was also quantified while an alternative solution that makes use of a lever arm attached with a universal joint to the satellite was proposed. Comparison simulations between the Smithsonian Astrophysical Observatory and the Martin Marietta (MMA) computer code of reteival maneuvers were also carried out. The agreement between the two, completely independent, codes was extremely close, demonstrating the reliability of the models. The slack tether dynamics during reel jams was analytically investigated in order to identify the limits of applicability of the SLACK3 computer code to this particular case. Test runs with SLACK3 were also carried out.

  2. Quantum systems that follow classical dynamics

    CERN Document Server

    Manfredi, G; Feix, M R

    1993-01-01

    For a special class of potentials, the dynamical evolution of any quantum wavepacket is entirely determined by the laws of classical mechanics. Here, the properties of this class are investigated both from the viewpoint of the Ehrenfest theorem (which provides the evolution of the average position and momentum), and the Wigner representation (which expresses quantum mechanics in a phase space formalism). Finally, these results are extended to the case of a charged particle in a uniform magnetic field. (author)

  3. Partial dynamical symmetries in quantum systems

    International Nuclear Information System (INIS)

    Leviatan, A

    2012-01-01

    We discuss the the notion of a partial dynamical symmetry (PDS), for which a prescribed symmetry is obeyed by only a subset of solvable eigenstates, while other eigenstates are strongly mixed. We present an explicit construction of Hamiltonians with this property, including higher-order terms, and portray their significance for spectroscopy and shape-phase transitions in nuclei. The occurrence of both a single PDS, relevant to stable structures, and of several PDSs, relevant to coexistence phenomena, are considered.

  4. Fluid and structural-dynamic piping system analysis

    International Nuclear Information System (INIS)

    Korthauer, H.J.; Lange, H.; Rychlik, G.

    1993-01-01

    By means of the fluid and structural-dynamic analyses conducted, the cooling system was qualified for all fluid-dynamic processes in normal and anomalous operation and in case of accidents. The boundary conditions assumed by us for the fluid and structural-dynamic analyses were confirmed by the forces and movements measured time for some operating conditions as a function of time. Expensive hardware measures such as additional supports or replacement of Tees were not necessary as we combined the fluid and structural-dynamic analyses and then demonstrated safety of the supports, connected components and some of the piping elements as such. (author)

  5. Leveraging natural dynamical structures to explore multi-body systems

    Science.gov (United States)

    Bosanac, Natasha

    Multi-body systems have become the target of an increasing number of mission concepts and observations, supplying further information about the composition, origin and dynamical environment of bodies within the solar system and beyond. In many of these scenarios, identification and characterization of the particular solutions that exist in a circular restricted three-body model is valuable. This insight into the underlying natural dynamical structures is achieved via the application of dynamical systems techniques. One application of such analysis is trajectory design for CubeSats, which are intended to explore cislunar space and other planetary systems. These increasingly complex mission objectives necessitate innovative trajectory design strategies for spacecraft within our solar system, as well as the capability for rapid and well-informed redesign. Accordingly, a trajectory design framework is constructed using dynamical systems techniques and demonstrated for the Lunar IceCube mission. An additional application explored in this investigation involves the motion of an exoplanet near a binary star system. Due to the strong gravitational field near a binary star, physicists have previously leveraged these systems as testbeds for examining the validity of gravitational and relativistic theories. In this investigation, a preliminary analysis into the effect of an additional three-body interaction on the dynamical environment near a large mass ratio binary system is conducted. As demonstrated through both of these sample applications, identification and characterization of the natural particular solutions that exist within a multi-body system supports a well-informed and guided analysis.

  6. Experimental analyses of dynamical systems involving shape memory alloys

    DEFF Research Database (Denmark)

    Enemark, Søren; Savi, Marcelo A.; Santos, Ilmar F.

    2015-01-01

    The use of shape memory alloys (SMAs) in dynamical systems has an increasing importance in engineering especially due to their capacity to provide vibration reductions. In this regard, experimental tests are essential in order to show all potentialities of this kind of systems. In this work, SMA...... springs are incorporated in a dynamical system that consists of a one degree of freedom oscillator connected to a linear spring and a mass, which is also connected to the SMA spring. Two types of springs are investigated defming two distinct systems: a pseudoelastic and a shape memory system....... The characterisation of the springs is evaluated by considering differential calorimetry scanning tests and also force-displacement tests at different temperatures. Free and forced vibration experiments are made in order to investigate the dynamical behaviour of the systems. For both systems, it is observed...

  7. The development of online doctor reviews in China: an analysis of the largest online doctor review website in China.

    Science.gov (United States)

    Hao, Haijing

    2015-06-01

    Since the time of Web 2.0, more and more consumers have used online doctor reviews to rate their doctors or to look for a doctor. This phenomenon has received health care researchers' attention worldwide, and many studies have been conducted on online doctor reviews in the United States and Europe. But no study has yet been done in China. Also, in China, without a mature primary care physician recommendation system, more and more Chinese consumers seek online doctor reviews to look for a good doctor for their health care concerns. This study sought to examine the online doctor review practice in China, including addressing the following questions: (1) How many doctors and specialty areas are available for online review? (2) How many online reviews are there on those doctors? (3) What specialty area doctors are more likely to be reviewed or receive more reviews? (4) Are those reviews positive or negative? This study explores an empirical dataset from Good Doctor website, haodf.com—the earliest and largest online doctor review and online health care community website in China—from 2006 to 2014, to examine the stated research questions by using descriptive statistics, binary logistic regression, and multivariate linear regression. The dataset from the Good Doctor website contained 314,624 doctors across China and among them, 112,873 doctors received 731,543 quantitative reviews and 772,979 qualitative reviews as of April 11, 2014. On average, 37% of the doctors had been reviewed on the Good Doctor website. Gynecology-obstetrics-pediatrics doctors were most likely to be reviewed, with an odds ratio (OR) of 1.497 (95% CI 1.461-1.535), and internal medicine doctors were less likely to be reviewed, with an OR of 0.94 (95% CI 0.921-0.960), relative to the combined small specialty areas. Both traditional Chinese medicine doctors and surgeons were more likely to be reviewed than the combined small specialty areas, with an OR of 1.483 (95% CI 1.442-1.525) and an OR of 1

  8. Distributed Coordination of Fractional Dynamical Systems with Exogenous Disturbances

    Directory of Open Access Journals (Sweden)

    Hongyong Yang

    2014-01-01

    Full Text Available Distributed coordination of fractional multiagent systems with external disturbances is studied. The state observer of fractional dynamical system is presented, and an adaptive pinning controller is designed for a little part of agents in multiagent systems without disturbances. This adaptive pinning controller with the state observer can ensure multiple agents' states reaching an expected reference tracking. Based on disturbance observers, the controllers are composited with the pinning controller and the state observer. By applying the stability theory of fractional order dynamical systems, the distributed coordination of fractional multiagent systems with external disturbances can be reached asymptotically.

  9. Electric Vehicle (EV) Charging Management with Dynamic Distribution System Tariff

    DEFF Research Database (Denmark)

    O'Connell, Niamh; Wu, Qiuwei; Østergaard, Jacob

    2011-01-01

    An electric vehicle (EV) charging schedule algorithm was proposed in this paper in order to charge EVs to meet EV users’ driving needs with the minimum EV charging cost and respect the local distribution system constraints. A day-ahead dynamic distribution system tariff scheme was proposed to avoid...... congestions in local distribution systems from the day-ahead planning perspective. Locational marginal pricing method was used to determine the dynamic distribution system tariff based on predicted day-ahead spot prices and predicted charging behaviors. Distribution grids of the Bornholm power system were...... used to carry out case studies to illustrate the proposed EV charging schedule algorithm....

  10. Applications of Nonlinear Dynamics Model and Design of Complex Systems

    CERN Document Server

    In, Visarath; Palacios, Antonio

    2009-01-01

    This edited book is aimed at interdisciplinary, device-oriented, applications of nonlinear science theory and methods in complex systems. In particular, applications directed to nonlinear phenomena with space and time characteristics. Examples include: complex networks of magnetic sensor systems, coupled nano-mechanical oscillators, nano-detectors, microscale devices, stochastic resonance in multi-dimensional chaotic systems, biosensors, and stochastic signal quantization. "applications of nonlinear dynamics: model and design of complex systems" brings together the work of scientists and engineers that are applying ideas and methods from nonlinear dynamics to design and fabricate complex systems.

  11. Dynamic flow control strategies of vehicle SCR Urea Dosing System

    Science.gov (United States)

    Lin, Wei; Zhang, Youtong; Asif, Malik

    2015-03-01

    Selective Catalyst Reduction(SCR) Urea Dosing System(UDS) directly affects the system accuracy and the dynamic response performance of a vehicle. However, the UDS dynamic response is hard to keep up with the changes of the engine's operating conditions. That will lead to low NO X conversion efficiency or NH3 slip. In order to optimize the injection accuracy and the response speed of the UDS in dynamic conditions, an advanced control strategy based on an air-assisted volumetric UDS is presented. It covers the methods of flow compensation and switching working conditions. The strategy is authenticated on an UDS and tested in different dynamic conditions. The result shows that the control strategy discussed results in higher dynamic accuracy and faster dynamic response speed of UDS. The inject deviation range is improved from being between -8% and 10% to -4% and 2% and became more stable than before, and the dynamic response time was shortened from 200 ms to 150 ms. The ETC cycle result shows that after using the new strategy the NH3 emission is reduced by 60%, and the NO X emission remains almost unchanged. The trade-off between NO X conversion efficiency and NH3 slip is mitigated. The studied flow compensation and switching working conditions can improve the dynamic performance of the UDS significantly and make the UDS dynamic response keep up with the changes of the engine's operating conditions quickly.

  12. Dynamic Radioisotope Power System Development for Space Explorations

    Energy Technology Data Exchange (ETDEWEB)

    Qualls, A L [ORNL

    2017-01-01

    Dynamic power conversion offers the potential to produce radioisotope power systems (RPS) that generate higher power outputs and utilize the Pu-238 radioisotope more efficiently than Radioisotope Thermoelectric Generators (RTG). Additionally, dynamic systems also offer the potential of producing generators with significantly reduced power degradation over the course of deep space missions so that more power will be available at the end of the mission when it is needed for both powering the science and transmitting the results. The development of dynamic generators involves addressing technical issues not typically associated with traditional thermoelectric generators. Developing long-life, robust and reliable dynamic conversion technology is challenging yet essential to building a suitable generator. Considerations include working within existing handling infrastructure where possible so that development costs can be kept low and integrating dynamic generators into spacecraft, which may be more complex than integration of static systems. Methods of interfacing to and controlling a dynamic generator must be considered and new potential failure modes must be taken into account. This paper will address some of the key issues of dynamic RPS design, development and adaption.Dynamic power conversion offers the potential to produce Radioisotope Power Systems (RPS) that generate higher power outputs and utilize the available heat source plutonium fuel more efficiently than Radioisotope Thermoelectric Generators. Additionally, dynamic systems offer the potential of producing generators with significantly reduced power degradation over the course of deep space missions so that more power would be available at the end of the mission, when it is needed most for both powering science instruments and transmitting the resulting data. The development of dynamic generators involves addressing technical issues not typically associated with traditional thermoelectric generators

  13. [Albert Schwietzer's doctoral thesis].

    Science.gov (United States)

    Gorn, M F

    1993-06-01

    A review on Albert Schweitzer's doctoral thesis "The psychiatric study on Jesus" and his analysis of the delirium of persecution, megalomania and hallucination in order to refuse different authors hypothesis about the Jesus, psychosis or paranoia. The author highlights the symbolism of Schweitzer's decision for studying medicine and dedicating his life and efforts to the full of need men of Africa so the importance of his philosophic studies on the western culture.

  14. Professional and Personal Development in Contemporary Gerontology Doctoral Education

    Science.gov (United States)

    Ewen, Heidi H.; Rowles, Graham D.; Watkins, John F.

    2012-01-01

    This article reports on the Gerontology Doctoral Student Assessment Model (GDSAM), a comprehensive web-based system premised on developing an evaluation mechanism attuned to the special requirements of advanced graduate education at the doctoral level. The system focuses on longitudinal tracking of selected dimensions of intellectual,…

  15. Volume Dynamics Propulsion System Modeling for Supersonics Vehicle Research

    Science.gov (United States)

    Kopasakis, George; Connolly, Joseph W.; Paxson, Daniel E.; Ma, Peter

    2010-01-01

    Under the NASA Fundamental Aeronautics Program the Supersonics Project is working to overcome the obstacles to supersonic commercial flight. The proposed vehicles are long slim body aircraft with pronounced aero-servo-elastic modes. These modes can potentially couple with propulsion system dynamics; leading to performance challenges such as aircraft ride quality and stability. Other disturbances upstream of the engine generated from atmospheric wind gusts, angle of attack, and yaw can have similar effects. In addition, for optimal propulsion system performance, normal inlet-engine operations are required to be closer to compressor stall and inlet unstart. To study these phenomena an integrated model is needed that includes both airframe structural dynamics as well as the propulsion system dynamics. This paper covers the propulsion system component volume dynamics modeling of a turbojet engine that will be used for an integrated vehicle Aero-Propulso-Servo-Elastic model and for propulsion efficiency studies.

  16. Simulation of noisy dynamical system by Deep Learning

    Science.gov (United States)

    Yeo, Kyongmin

    2017-11-01

    Deep learning has attracted huge attention due to its powerful representation capability. However, most of the studies on deep learning have been focused on visual analytics or language modeling and the capability of the deep learning in modeling dynamical systems is not well understood. In this study, we use a recurrent neural network to model noisy nonlinear dynamical systems. In particular, we use a long short-term memory (LSTM) network, which constructs internal nonlinear dynamics systems. We propose a cross-entropy loss with spatial ridge regularization to learn a non-stationary conditional probability distribution from a noisy nonlinear dynamical system. A Monte Carlo procedure to perform time-marching simulations by using the LSTM is presented. The behavior of the LSTM is studied by using noisy, forced Van der Pol oscillator and Ikeda equation.

  17. Synthesis of recurrent neural networks for dynamical system simulation.

    Science.gov (United States)

    Trischler, Adam P; D'Eleuterio, Gabriele M T

    2016-08-01

    We review several of the most widely used techniques for training recurrent neural networks to approximate dynamical systems, then describe a novel algorithm for this task. The algorithm is based on an earlier theoretical result that guarantees the quality of the network approximation. We show that a feedforward neural network can be trained on the vector-field representation of a given dynamical system using backpropagation, then recast it as a recurrent network that replicates the original system's dynamics. After detailing this algorithm and its relation to earlier approaches, we present numerical examples that demonstrate its capabilities. One of the distinguishing features of our approach is that both the original dynamical systems and the recurrent networks that simulate them operate in continuous time. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. SYSTEM DYNAMICS OF MANAGEMENT OF "UNFORESEEN CIRCUMSTANCES" OF THE PROJECT

    Directory of Open Access Journals (Sweden)

    Богдан Владимирович ГАЙДАБРУС

    2015-05-01

    Full Text Available Approaches for project contingency management through risk management and influence of stakeholders. Proposed system dynamic contingency project management model. The model describes the effects of various factors on the phase of project management through contingency.

  19. A unifying definition of synchronization for dynamical systems

    OpenAIRE

    Brown, Reggie; Kocarev, Ljupco

    1998-01-01

    We propose a unified definition for synchronization. By example we show that the synchronization phenomena discussed in the dynamical systems literature can be described within the framework of this definition.

  20. Cognitive Models for Learning to Control Dynamic Systems

    National Research Council Canada - National Science Library

    Eberhart, Russ; Hu, Xiaohui; Chen, Yaobin

    2008-01-01

    Report developed under STTR contract for topic "Cognitive models for learning to control dynamic systems" demonstrated a swarm intelligence learning algorithm and its application in unmanned aerial vehicle (UAV) mission planning...

  1. THE DYNAMICS OF THREE-PLANET SYSTEMS: AN APPROACH FROM A DYNAMICAL SYSTEM

    International Nuclear Information System (INIS)

    Shikita, Bungo; Yamada, Shoichi; Koyama, Hiroko

    2010-01-01

    We study in detail the motions of three planets interacting with each other under the influence of a central star. It is known that the system with more than two planets becomes unstable after remaining quasi-stable for long times, leading to highly eccentric orbital motions or ejections of some of the planets. In this paper, we are concerned with the underlying physics for this quasi-stability as well as the subsequent instability and advocate the so-called stagnant motion in the phase space, which has been explored in the field of a dynamical system. We employ the Lyapunov exponent, the power spectra of orbital elements, and the distribution of the durations of quasi-stable motions to analyze the phase-space structure of the three-planet system, the simplest and hopefully representative one that shows the instability. We find from the Lyapunov exponent that the system is almost non-chaotic in the initial quasi-stable state whereas it becomes intermittently chaotic thereafter. The non-chaotic motions produce the horizontal dense band in the action-angle plot whereas the voids correspond to the chaotic motions. We obtain power laws for the power spectra of orbital eccentricities. Power-law distributions are also found for the durations of quasi-stable states. With all these results combined together, we may reach the following picture: the phase space consists of the so-called KAM tori surrounded by satellite tori and imbedded in the chaotic sea. The satellite tori have a self-similar distribution and are responsible for the scale-free power-law distributions of the duration times. The system is trapped around one of the KAM torus and the satellites for a long time (the stagnant motion) and moves to another KAM torus with its own satellites from time to time, corresponding to the intermittent chaotic behaviors.

  2. The dynamics of surge in compression systems

    Indian Academy of Sciences (India)

    In air-compression systems, instabilities occur during operation close to their peak pressure-rise capability. However, the peak efficiency of a compression system lies close to this region of instability. A surge is a violent mode of instability where there is total breakdown of flow in the system and pressure-rise capability is lost ...

  3. Dynamic stabilization of regular linear systems

    NARCIS (Netherlands)

    Weiss, G; Curtain, RF

    We consider a general class of infinite-dimensional linear systems, called regular linear systems, for which convenient representations are known to exist both in time and in frequency domain, For this class of systems, we investigate the concepts of stabilizability and detectability, in particular,

  4. Temporal logic runtime verification of dynamic systems

    CSIR Research Space (South Africa)

    Seotsanyana, M

    2010-07-01

    Full Text Available Robotic computer systems are increasingly ubiquitous in everyday life and this has led to a need to develop safe and reliable systems. To ensure safety and reliability of these systems, the following three main verification techniques are usually...

  5. [Development of Audio Indicator System for Respiratory Dynamic CT Imaging].

    Science.gov (United States)

    Muramatsu, Shun; Moriya, Hiroshi; Tsukagoshi, Shinsuke; Yamada, Norikazu

    We created the device, which can conduct a radiological technologist's voice to a subject during CT scanning. For 149 lung cancer, dynamic respiratory CT were performed. 92 cases were performed using this device, the others were without this device. The respiratory cycle and respiratory amplitude were analyzed from the lung density. A stable respirating cycle was obtained by using the audio indicator system. The audio indicator system is useful for respiratory dynamic CT.

  6. Sequencing dynamic storage systems with multiple lifts and shuttles

    NARCIS (Netherlands)

    Carlo, Hector J.; Vis, Iris F. A.

    2012-01-01

    New types of Automated Storage and Retrieval Systems (AS/RS) able to achieve high throughput are continuously being developed and require new control polices to take full advantage of the developed system. In this paper, a dynamic storage system has been studied as developed by Vanderlande

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

    Science.gov (United States)

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

  8. Nambu-Poisson reformulation of the finite dimensional dynamical systems

    International Nuclear Information System (INIS)

    Baleanu, D.; Makhaldiani, N.

    1998-01-01

    A system of nonlinear ordinary differential equations which in a particular case reduces to Volterra's system is introduced. We found in two simplest cases the complete sets of the integrals of motion using Nambu-Poisson reformulation of the Hamiltonian dynamics. In these cases we have solved the systems by quadratures

  9. A Pathophysiological Model-Driven Communication for Dynamic Distributed Medical Best Practice Guidance Systems.

    Science.gov (United States)

    Hosseini, Mohammad; Jiang, Yu; Wu, Poliang; Berlin, Richard B; Ren, Shangping; Sha, Lui

    2016-11-01

    There is a great divide between rural and urban areas, particularly in medical emergency care. Although medical best practice guidelines exist and are in hospital handbooks, they are often lengthy and difficult to apply clinically. The challenges are exaggerated for doctors in rural areas and emergency medical technicians (EMT) during patient transport. In this paper, we propose the concept of distributed executable medical best practice guidance systems to assist adherence to best practice from the time that a patient first presents at a rural hospital, through diagnosis and ambulance transfer to arrival and treatment at a regional tertiary hospital center. We codify complex medical knowledge in the form of simplified distributed executable disease automata, from the thin automata at rural hospitals to the rich automata in the regional center hospitals. However, a main challenge is how to efficiently and safely synchronize distributed best practice models as the communication among medical facilities, devices, and professionals generates a large number of messages. This complex problem of patient diagnosis and transport from rural to center facility is also fraught with many uncertainties and changes resulting in a high degree of dynamism. A critically ill patient's medical conditions can change abruptly in addition to changes in the wireless bandwidth during the ambulance transfer. Such dynamics have yet to be addressed in existing literature on telemedicine. To address this situation, we propose a pathophysiological model-driven message exchange communication architecture that ensures the real-time and dynamic requirements of synchronization among distributed emergency best practice models are met in a reliable and safe manner. Taking the signs, symptoms, and progress of stroke patients transported across a geographically distributed healthcare network as the motivating use case, we implement our communication system and apply it to our developed best practice

  10. A review of dynamic characteristics of magnetically levitated vehicle systems

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Y.; Chen, S.S.

    1995-11-01

    The dynamic response of magnetically levitated (maglev) ground transportation systems has important consequences for safety and ride quality, guideway design, and system costs. Ride quality is determined by vehicle response and by environmental factors such as humidity and noise. The dynamic response of the vehicles is the key element in determining ride quality, while vehicle stability is an important safety-related element. To design a guideway that provides acceptable ride quality in the stable region, vehicle dynamics must be understood. Furthermore, the trade-off between guideway smoothness and levitation and control systems must be considered if maglev systems are to be economically feasible. The link between the guideway and the other maglev components is vehicle dynamics. For a commercial maglev system, vehicle dynamics must be analyzed and tested in detail. This report, which reviews various aspects of the dynamic characteristics, experiments and analysis, and design guidelines for maglev systems, discusses vehicle stability, motion dependent magnetic force components, guideway characteristics, vehicle/ guideway interaction, ride quality, suspension control laws, aerodynamic loads and other excitations, and research needs.

  11. Tips for Talking to Your Doctor

    Science.gov (United States)

    ... doctor is explaining, ask him or her to draw a picture of it. Or ask your doctor ... information on this subject. Featured ContentFamily Doctor vs. Quick-care ClinicRead Article >>Family Doctor vs. Quick-care ...

  12. Dynamic Calibration and Verification Device of Measurement System for Dynamic Characteristic Coefficients of Sliding Bearing

    Science.gov (United States)

    Chen, Runlin; Wei, Yangyang; Shi, Zhaoyang; Yuan, Xiaoyang

    2016-01-01

    The identification accuracy of dynamic characteristics coefficients is difficult to guarantee because of the errors of the measurement system itself. A novel dynamic calibration method of measurement system for dynamic characteristics coefficients is proposed in this paper to eliminate the errors of the measurement system itself. Compared with the calibration method of suspension quality, this novel calibration method is different because the verification device is a spring-mass system, which can simulate the dynamic characteristics of sliding bearing. The verification device is built, and the calibration experiment is implemented in a wide frequency range, in which the bearing stiffness is simulated by the disc springs. The experimental results show that the amplitude errors of this measurement system are small in the frequency range of 10 Hz–100 Hz, and the phase errors increase along with the increasing of frequency. It is preliminarily verified by the simulated experiment of dynamic characteristics coefficients identification in the frequency range of 10 Hz–30 Hz that the calibration data in this frequency range can support the dynamic characteristics test of sliding bearing in this frequency range well. The bearing experiments in greater frequency ranges need higher manufacturing and installation precision of calibration device. Besides, the processes of calibration experiments should be improved. PMID:27483283

  13. Formal First Integrals of General Dynamical Systems

    Directory of Open Access Journals (Sweden)

    Jia Jiao

    2016-01-01

    Full Text Available The goal of this paper is trying to make a complete study on the integrability for general analytic nonlinear systems by first integrals. We will firstly give an exhaustive discussion on analytic planar systems. Then a class of higher dimensional systems with invariant manifolds will be considered; we will develop several criteria for existence of formal integrals and give some applications to illustrate our results at last.

  14. Social tipping points and Earth systems dynamics

    Directory of Open Access Journals (Sweden)

    R. Alexander eBentley

    2014-08-01

    Full Text Available Recently, Early Warning Signals (EWS have been developed to predict tipping points in Earth Systems. This discussion highlights the potential to apply EWS to human social and economic systems, which may also undergo similar critical transitions. Social tipping points are particularly difficult to predict, however, and the current formulation of EWS, based on a physical system analogy, may be insufficient. As an alternative set of EWS for social systems, we join with other authors encouraging a focus on heterogeneity, connectivity through social networks and individual thresholds to change.

  15. Multibody system dynamics and mechatronics. Plenary lecture

    Energy Technology Data Exchange (ETDEWEB)

    Hiller, M.H.; Hirsch, K. [Duisburg-Essen Univ., Duisburg (Germany). Faculty of Engineering

    2006-02-15

    Mechatronics as an interdisciplinary combination of domains of mechanical engineering, electrical engineering, electronics, and computer science has developed in industry and universities since the eighties of the last century, and it is meanwhile fully established in many technical areas. The main focus of the mechatronic approach is to extend and to complete the design process of mechanical and more general engineering systems by incorporating from the very beginning sensors and controllers - which includes also the required information processing - and thus being able to generate partly intelligent products. The components and modules of such systems originate from mechanical engineering, from electrical engineering or from other engineering domains. Methods for describing and designing these components and modules are based in the fields of applied mechanics, electrical engineering, system theory, control and automation theory, and information processing. In particular, in mechatronic systems like robots, manipulation systems, machine tools, or all kinds of vehicles, the multibody systems approach offers a powerful tool to model the mechanical properties of the system in an appropriate manner. In this paper, methodologies for the development of formalisms and software for modeling and simulation of multibody and mechatronic systems will be presented and illustrated by examples from automotive systems and robotics. (orig.)

  16. The System Dynamics Model User Sustainability Explorer (SD-MUSE): a user-friendly tool for interpreting system dynamic models

    Science.gov (United States)

    System Dynamics (SD) models are useful for holistic integration of data to evaluate indirect and cumulative effects and inform decisions. Complex SD models can provide key insights into how decisions affect the three interconnected pillars of sustainability. However, the complexi...

  17. Energy flow theory of nonlinear dynamical systems with applications

    CERN Document Server

    Xing, Jing Tang

    2015-01-01

    This monograph develops a generalised energy flow theory to investigate non-linear dynamical systems governed by ordinary differential equations in phase space and often met in various science and engineering fields. Important nonlinear phenomena such as, stabilities, periodical orbits, bifurcations and chaos are tack-led and the corresponding energy flow behaviors are revealed using the proposed energy flow approach. As examples, the common interested nonlinear dynamical systems, such as, Duffing’s oscillator, Van der Pol’s equation, Lorenz attractor, Rössler one and SD oscillator, etc, are discussed. This monograph lights a new energy flow research direction for nonlinear dynamics. A generalised Matlab code with User Manuel is provided for readers to conduct the energy flow analysis of their nonlinear dynamical systems. Throughout the monograph the author continuously returns to some examples in each chapter to illustrate the applications of the discussed theory and approaches. The book can be used as ...

  18. Differential equations, dynamical systems, and an introduction to chaos

    CERN Document Server

    Smale, Stephen; Devaney, Robert L

    2003-01-01

    Thirty years in the making, this revised text by three of the world''s leading mathematicians covers the dynamical aspects of ordinary differential equations. it explores the relations between dynamical systems and certain fields outside pure mathematics, and has become the standard textbook for graduate courses in this area. The Second Edition now brings students to the brink of contemporary research, starting from a background that includes only calculus and elementary linear algebra.The authors are tops in the field of advanced mathematics, including Steve Smale who is a recipient of the Field''s Medal for his work in dynamical systems.* Developed by award-winning researchers and authors* Provides a rigorous yet accessible introduction to differential equations and dynamical systems* Includes bifurcation theory throughout* Contains numerous explorations for students to embark uponNEW IN THIS EDITION* New contemporary material and updated applications* Revisions throughout the text, including simplification...

  19. Entanglement dynamics in itinerant fermionic and bosonic systems

    Science.gov (United States)

    Pillarishetty, Durganandini

    2017-04-01

    The concept of quantum entanglement of identical particles is fundamental in a wide variety of quantum information contexts involving composite quantum systems. However, the role played by particle indistinguishabilty in entanglement determination is being still debated. In this work, we study, theoretically, the entanglement dynamics in some itinerant bosonic and fermionic systems. We show that the dynamical behaviour of particle entanglement and spatial or mode entanglement are in general different. We also discuss the effect of fermionic and bosonic statistics on the dynamical behaviour. We suggest that the different dynamical behaviour can be used to distinguish between particle and mode entanglement in identical particle systems and discuss possible experimental realizations for such studies. I acknowledge financial support from DST, India through research Grant.

  20. Dynamic system simulation of small satellite projects

    NARCIS (Netherlands)

    Raif, M.; Walter, U.; Bouwmeester, R.

    2009-01-01

    A prerequisite to accomplish a system simulation is to have a system model holding all necessary project information in a centralized repository that can be accessed and edited by all parties involved. At the Institute of Astronautics of the Technische Universitaet Muenchen a modular approach for