WorldWideScience

Sample records for coupling heterogeneous knowledge

  1. Employees and Creativity: Social Ties and Access to Heterogeneous Knowledge

    Science.gov (United States)

    Huang, Chiung-En; Liu, Chih-Hsing Sam

    2015-01-01

    This study dealt with employee social ties, knowledge heterogeneity contacts, and the generation of creativity. Although prior studies demonstrated a relationship between network position and creativity, inadequate attention has been paid to network ties and heterogeneity knowledge contacts. This study considered the social interaction processes…

  2. Employees and Creativity: Social Ties and Access to Heterogeneous Knowledge

    Science.gov (United States)

    Huang, Chiung-En; Liu, Chih-Hsing Sam

    2015-01-01

    This study dealt with employee social ties, knowledge heterogeneity contacts, and the generation of creativity. Although prior studies demonstrated a relationship between network position and creativity, inadequate attention has been paid to network ties and heterogeneity knowledge contacts. This study considered the social interaction processes…

  3. Erosion of synchronization: Coupling heterogeneity and network structure

    Science.gov (United States)

    Skardal, Per Sebastian; Taylor, Dane; Sun, Jie; Arenas, Alex

    2016-06-01

    We study the dynamics of network-coupled phase oscillators in the presence of coupling frustration. It was recently demonstrated that in heterogeneous network topologies, the presence of coupling frustration causes perfect phase synchronization to become unattainable even in the limit of infinite coupling strength. Here, we consider the important case of heterogeneous coupling functions and extend previous results by deriving analytical predictions for the total erosion of synchronization. Our analytical results are given in terms of basic quantities related to the network structure and coupling frustration. In addition to fully heterogeneous coupling, where each individual interaction is allowed to be distinct, we also consider partially heterogeneous coupling and homogeneous coupling in which the coupling functions are either unique to each oscillator or identical for all network interactions, respectively. We demonstrate the validity of our theory with numerical simulations of multiple network models, and highlight the interesting effects that various coupling choices and network models have on the total erosion of synchronization. Finally, we consider some special network structures with well-known spectral properties, which allows us to derive further analytical results.

  4. Two coupled queues with heterogeneous traffic

    NARCIS (Netherlands)

    Borst, S.C.; Boxma, O.J.; Uitert, M.J.G. van

    2001-01-01

    We consider a system with two heterogeneous traffic classes, one having light-tailed characteristics, the other one exhibiting heavy-tailed properties. When both classes are backlogged, the two corresponding queues are each served at a certain nominal rate. However, when one queue empties, the servi

  5. Managing heterogeneous knowledge: A Theory of External Knowledge Integration

    NARCIS (Netherlands)

    Kraaijenbrink, Jeroen; Wijnhoven, Alphonsus B.J.M.

    2008-01-01

    Knowledge integration has been theorised at the levels of organisations and inter-organisational dyads. However, no theory exists yet of the integration of knowledge from an organisation's environment. This paper addresses this void in the literature by presenting a theory of external knowledge

  6. Knowledge-based adaptive polarimetric detection in heterogeneous clutter

    Institute of Scientific and Technical Information of China (English)

    Yinan Zhao,Fengcong Li,; Xiaolin Qiao

    2014-01-01

    The detection performance and the constant false alarm rate behavior of the conventional adaptive detectors are severely degraded in heterogeneous clutter. This paper designs and analy-ses a knowledge-based (KB) adaptive polarimetric detector in het-erogeneous clutter. The proposed detection scheme is composed of a data selector using polarization knowledge and an adaptive polarization detector using training data. A polarization data se-lector based on the maximum likelihood estimation is proposed to remove outliers from the heterogeneous training data. This selector can remove outliers effectively, thus the training data is purified for estimating the clutter covariance matrix. Consequently, the performance of the adaptive detector is improved. We assess the performance of the KB adaptive polarimetric detector and the adaptive polarimetric detector without a data selector using sim-ulated data and IPIX radar data. The results show that the KB adaptive polarization detector outperforms its non-KB counter-parts.

  7. Multiscale Universal Interface: A concurrent framework for coupling heterogeneous solvers

    Science.gov (United States)

    Tang, Yu-Hang; Kudo, Shuhei; Bian, Xin; Li, Zhen; Karniadakis, George Em

    2015-09-01

    Concurrently coupled numerical simulations using heterogeneous solvers are powerful tools for modeling multiscale phenomena. However, major modifications to existing codes are often required to enable such simulations, posing significant difficulties in practice. In this paper we present a C++ library, i.e. the Multiscale Universal Interface (MUI), which is capable of facilitating the coupling effort for a wide range of multiscale simulations. The library adopts a header-only form with minimal external dependency and hence can be easily dropped into existing codes. A data sampler concept is introduced, combined with a hybrid dynamic/static typing mechanism, to create an easily customizable framework for solver-independent data interpretation. The library integrates MPI MPMD support and an asynchronous communication protocol to handle inter-solver information exchange irrespective of the solvers' own MPI awareness. Template metaprogramming is heavily employed to simultaneously improve runtime performance and code flexibility. We validated the library by solving three different multiscale problems, which also serve to demonstrate the flexibility of the framework in handling heterogeneous models and solvers. In the first example, a Couette flow was simulated using two concurrently coupled Smoothed Particle Hydrodynamics (SPH) simulations of different spatial resolutions. In the second example, we coupled the deterministic SPH method with the stochastic Dissipative Particle Dynamics (DPD) method to study the effect of surface grafting on the hydrodynamics properties on the surface. In the third example, we consider conjugate heat transfer between a solid domain and a fluid domain by coupling the particle-based energy-conserving DPD (eDPD) method with the Finite Element Method (FEM).

  8. Multiscale Universal Interface: A concurrent framework for coupling heterogeneous solvers

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Yu-Hang, E-mail: yuhang_tang@brown.edu [Division of Applied Mathematics, Brown University, Providence, RI (United States); Kudo, Shuhei, E-mail: shuhei-kudo@outlook.jp [Graduate School of System Informatics, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, 657-8501 (Japan); Bian, Xin, E-mail: xin_bian@brown.edu [Division of Applied Mathematics, Brown University, Providence, RI (United States); Li, Zhen, E-mail: zhen_li@brown.edu [Division of Applied Mathematics, Brown University, Providence, RI (United States); Karniadakis, George Em, E-mail: george_karniadakis@brown.edu [Division of Applied Mathematics, Brown University, Providence, RI (United States); Collaboratory on Mathematics for Mesoscopic Modeling of Materials, Pacific Northwest National Laboratory, Richland, WA 99354 (United States)

    2015-09-15

    Graphical abstract: - Abstract: Concurrently coupled numerical simulations using heterogeneous solvers are powerful tools for modeling multiscale phenomena. However, major modifications to existing codes are often required to enable such simulations, posing significant difficulties in practice. In this paper we present a C++ library, i.e. the Multiscale Universal Interface (MUI), which is capable of facilitating the coupling effort for a wide range of multiscale simulations. The library adopts a header-only form with minimal external dependency and hence can be easily dropped into existing codes. A data sampler concept is introduced, combined with a hybrid dynamic/static typing mechanism, to create an easily customizable framework for solver-independent data interpretation. The library integrates MPI MPMD support and an asynchronous communication protocol to handle inter-solver information exchange irrespective of the solvers' own MPI awareness. Template metaprogramming is heavily employed to simultaneously improve runtime performance and code flexibility. We validated the library by solving three different multiscale problems, which also serve to demonstrate the flexibility of the framework in handling heterogeneous models and solvers. In the first example, a Couette flow was simulated using two concurrently coupled Smoothed Particle Hydrodynamics (SPH) simulations of different spatial resolutions. In the second example, we coupled the deterministic SPH method with the stochastic Dissipative Particle Dynamics (DPD) method to study the effect of surface grafting on the hydrodynamics properties on the surface. In the third example, we consider conjugate heat transfer between a solid domain and a fluid domain by coupling the particle-based energy-conserving DPD (eDPD) method with the Finite Element Method (FEM)

  9. Multiscale Universal Interface: A Concurrent Framework for Coupling Heterogeneous Solvers

    CERN Document Server

    Tang, Yu-Hang; Bian, Xin; Li, Zhen; Karniadakis, George E

    2014-01-01

    Concurrently coupled numerical simulations using heterogeneous solvers are powerful tools for modeling multiscale phenomena. However, major modifications to existing codes are often required to enable such simulations, posing significant difficulties in practice. In this paper we present a C++ library, i.e. the Multiscale Universal Interface (MUI), which is capable of facilitating the coupling effort for a wide range of multiscale simulations. The library adopts a header-only form with minimal external dependency and hence can be easily dropped into existing codes. A data sampler concept is introduced, combined with a hybrid dynamic/static typing mechanism, to create an easily customizable framework for solver-independent data interpretation. The library integrates MPI MPMD support and an asynchronous communication protocol to handle inter-solver information exchange irrespective of the solvers' own MPI awareness. Template metaprogramming is heavily employed to simultaneously improve runtime performance and c...

  10. Modeling the oxidative coupling of methane:Heterogeneous chemistry coupled with 3D flow field simulation

    Institute of Scientific and Technical Information of China (English)

    Yaghobi Nakisa; Ghoreishy Mir Hamid Reza

    2009-01-01

    The oxidative coupling of methane (OCM) over titanate perovskite catalyst has been developed by three-dimensional numerical simulations of flow field coupled with heat transfer as well as heterogeneous kinetic model.The reaction was assumed to take place both in the gas phase and on the catalytic surface.Kinetic rate constants were experimentally obtained using a ten step kinetic model.The simulation results agree quite well with the data of OCM experiments,which were used to investigate the effect of temperature on the selectivity and conversion obtained in the methane oxidative coupling process.The conversion of methane linearly increased with temperature and the selectivity of C2 was practically constant in the temperature range of 973-1073 K.The study shows that CFD tools make it possible to implement the heterogeneous kinetic model even for high exothermic reaction such as OCM.

  11. Semantic Health Knowledge Graph: Semantic Integration of Heterogeneous Medical Knowledge and Services

    Directory of Open Access Journals (Sweden)

    Longxiang Shi

    2017-01-01

    Full Text Available With the explosion of healthcare information, there has been a tremendous amount of heterogeneous textual medical knowledge (TMK, which plays an essential role in healthcare information systems. Existing works for integrating and utilizing the TMK mainly focus on straightforward connections establishment and pay less attention to make computers interpret and retrieve knowledge correctly and quickly. In this paper, we explore a novel model to organize and integrate the TMK into conceptual graphs. We then employ a framework to automatically retrieve knowledge in knowledge graphs with a high precision. In order to perform reasonable inference on knowledge graphs, we propose a contextual inference pruning algorithm to achieve efficient chain inference. Our algorithm achieves a better inference result with precision and recall of 92% and 96%, respectively, which can avoid most of the meaningless inferences. In addition, we implement two prototypes and provide services, and the results show our approach is practical and effective.

  12. Mapping QoS Classes in Loose Coupling Heterogeneous Networks

    Directory of Open Access Journals (Sweden)

    Firas Ousta

    2014-10-01

    Full Text Available One of the main objectives of Heterogeneous Wireless Access Networks (HWAN is to integrate the different wireless access technologies, such as Universal Mobile Telecommunication System (UMTS, Worldwide Interoperability for Microwave Access (WiMAX and Wireless Local Area Network (WLAN, with a common IP-based network in order to offer mobile users continuous and unified service in a transparent way. However, one of the major issues is to support end-to-end Quality of Service (QoS across all these technologies at all stages of the service from set-up to handoff. We present, in this study, a novel method of mapping QoS of UMTS and WiMAX over a loose coupling environment across Internet Protocol/Differentiated Service (IP/DiffServ network.

  13. Model of coupled gas flow and deformation process in heterogeneous coal seams and its application

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chun-hui; ZHAO Quan-sheng; YU Yong-jiang

    2011-01-01

    The heterogeneity of coal was studied by mechanical tests. Probability plots of experimental data show that the mechanical parameters of heterogeneous coal follow a Weibull distribution. Based on elasto-plastic mechanics and gas dynamics, the model of coupled gas flow and deformation process of heterogeneous coal was presented and the effects of heterogeneity of coal on gas flow and failure of coal were investigated. Major findings include: The effect of the heterogeneity of coal on gas flow and mechanical failure of coal can be considered by the model in this paper. Failure of coal has a great effect on gas flow.

  14. Heterogeneous Coupling between Interdependent Lattices Promotes the Cooperation in the Prisoner's Dilemma Game.

    Science.gov (United States)

    Xia, Cheng-Yi; Meng, Xiao-Kun; Wang, Zhen

    2015-01-01

    In the research realm of game theory, interdependent networks have extended the content of spatial reciprocity, which needs the suitable coupling between networks. However, thus far, the vast majority of existing works just assume that the coupling strength between networks is symmetric. This hypothesis, to some extent, seems inconsistent with the ubiquitous observation of heterogeneity. Here, we study how the heterogeneous coupling strength, which characterizes the interdependency of utility between corresponding players of both networks, affects the evolution of cooperation in the prisoner's dilemma game with two types of coupling schemes (symmetric and asymmetric ones). Compared with the traditional case, we show that heterogeneous coupling greatly promotes the collective cooperation. The symmetric scheme seems much better than the asymmetric case. Moreover, the role of varying amplitude of coupling strength is also studied on these two interdependent ways. Current findings are helpful for us to understand the evolution of cooperation within many real-world systems, in particular for the interconnected and interrelated systems.

  15. Integration of Heterogeneous Information Sources into a Knowledge Resource Management System for Lifelong Learning

    NARCIS (Netherlands)

    Demidova, Elena; Ternier, Stefaan; Olmedilla, Daniel; Duval, Erik; Dicerto, Michele; Stefanov, Krassen; Sacristán, Naiara

    2007-01-01

    Demidova, E., Ternier, S., Olmedilla, D., Duval, E., Dicerto, M., Stefanov, K., et al. (2007). Integration of Heterogeneous Information Sources into a Knowledge Resource Management System for Lifelong. TENCompetence Workshop on Service Oriented Approaches and Lifelong Competence Development Infrastr

  16. —Impact of Customer Knowledge Heterogeneity on Bundling Strategy

    OpenAIRE

    Amiya Basu; Padmal Vitharana

    2009-01-01

    We consider a marketer of components who can select one of three alternative pricing strategies: (1) a pure component strategy (i.e., the customer can only buy the components individually), (2) a pure bundling strategy (i.e., the components must be purchased together), or (3) a mixed bundling strategy (i.e., the customer may buy a component individually, or buy the bundle). We consider a market where customer knowledge of components varies and propose that a high-knowledge customer can determ...

  17. Quantitative, qualitative, and collaborative methods: approaching indigenous ecological knowledge heterogeneity

    Directory of Open Access Journals (Sweden)

    Jeremy Spoon

    2014-09-01

    Full Text Available I discuss the use of quantitative, qualitative, and collaborative methods to document and operationalize Indigenous ecological knowledge, using case studies from the Nepalese Himalaya and Great Basin. Both case studies applied results to natural and cultural resource management and interpretation for the public. These approaches attempt to reposition the interview subjects to serve as active contributors to the research and its outcomes. I argue that the study of any body of Indigenous knowledge requires a context-specific methodology and mutually agreed upon processes and outcomes. In the Nepalese Himalaya, I utilized linked quantitative and qualitative methods to understand how tourism influenced Sherpa place-based spiritual concepts, species, and landscape knowledge inside Sagarmatha (Mount Everest National Park and Buffer Zone. In this method, Sherpa collaborated in the development of the research questions, the design, and in the review of results. The research in the Great Basin employed collaborative qualitative methods to document Numic (Southern Paiute and Western Shoshone ecological knowledge of federal lands within their ancestral territory and attempted to piece together fragmented and contested histories of place. In this method, Numic peoples collaborated on the development of research questions and design; however they also conducted most of the interviews. In both cases, I selected particular suites of methods depending on the context and created forums for the translation of this information to applied outcomes. The methods were also improved and innovated through praxis.

  18. Using conceptual spaces to fuse knowledge from heterogeneous robot platforms

    Science.gov (United States)

    Kira, Zsolt

    2010-04-01

    As robots become more common, it becomes increasingly useful for many applications to use them in teams that sense the world in a distributed manner. In such situations, the robots or a central control center must communicate and fuse information received from multiple sources. A key challenge for this problem is perceptual heterogeneity, where the sensors, perceptual representations, and training instances used by the robots differ dramatically. In this paper, we use Gärdenfors' conceptual spaces, a geometric representation with strong roots in cognitive science and psychology, in order to represent the appearance of objects and show how the problem of heterogeneity can be intuitively explored by looking at the situation where multiple robots differ in their conceptual spaces at different levels. To bridge low-level sensory differences, we abstract raw sensory data into properties (such as color or texture categories), represented as Gaussian Mixture Models, and demonstrate that this facilitates both individual learning and the fusion of concepts between robots. Concepts (e.g. objects) are represented as a fuzzy mixture of these properties. We then treat the problem where the conceptual spaces of two robots differ and they only share a subset of these properties. In this case, we use joint interaction and statistical metrics to determine which properties are shared. Finally, we show how conceptual spaces can handle the combination of such missing properties when fusing concepts received from different robots. We demonstrate the fusion of information in real-robot experiments with a Mobile Robots Amigobot and Pioneer 2DX with significantly different cameras and (on one robot) a SICK lidar.ÿÿÿÿ

  19. Heterogeneous Palladium Chloride Catalyzed Ligand-free Suzuki-Miyaura Coupling Reactions at Ambient Temperature

    Institute of Scientific and Technical Information of China (English)

    WANG Min; WANG Lei

    2008-01-01

    A mild and efficient ligand-free Suzuki-Miyaura coupling reaction catalyzed by heterogeneous palladium chloride was developed at room temperature in a short reaction time under air atmosphere.Various phenyl iodides,bromides and activated chlorides were coupled with sodium tetraphenylborate or phenylboronic acids efficiently to afford the corresponding cross-coupled products in good to excellent yields.Furthermore,the catalyst could be recycled up to four times without loss of its activity.

  20. Effect of Transmurally Heterogeneous Myocyte Excitation-Contraction Coupling on Left Ventricular Electromechanics

    OpenAIRE

    2009-01-01

    The excitation-contraction coupling properties of cardiac myocytes isolated from different regions of the mammalian left ventricular wall have been shown to vary considerably, with uncertain effects on ventricular function. We embedded a cell-level excitation-contraction coupling model with region-dependent parameters within a simple finite element model of left ventricular geometry to study effects of electromechanical heterogeneity on local myocardial mechanics and global hemodynamics. This...

  1. Heterogeneous Coupling between Interdependent Lattices Promotes the Cooperation in the Prisoner's Dilemma Game.

    Directory of Open Access Journals (Sweden)

    Cheng-Yi Xia

    Full Text Available In the research realm of game theory, interdependent networks have extended the content of spatial reciprocity, which needs the suitable coupling between networks. However, thus far, the vast majority of existing works just assume that the coupling strength between networks is symmetric. This hypothesis, to some extent, seems inconsistent with the ubiquitous observation of heterogeneity. Here, we study how the heterogeneous coupling strength, which characterizes the interdependency of utility between corresponding players of both networks, affects the evolution of cooperation in the prisoner's dilemma game with two types of coupling schemes (symmetric and asymmetric ones. Compared with the traditional case, we show that heterogeneous coupling greatly promotes the collective cooperation. The symmetric scheme seems much better than the asymmetric case. Moreover, the role of varying amplitude of coupling strength is also studied on these two interdependent ways. Current findings are helpful for us to understand the evolution of cooperation within many real-world systems, in particular for the interconnected and interrelated systems.

  2. Modular Approach to Heterogenous Catalysis. Manipulation of Cross-Coupling Catalyst Activity.

    Science.gov (United States)

    Stibingerova, Iva; Voltrova, Svatava; Kocova, Sarka; Lindale, Matthew; Srogl, Jiri

    2016-01-15

    A new type of robust, heterogeneous, modular Pd catalyst with metal embedded in the gel matrix is presented. The regulatory element of its catalytic activity has been introduced via chemical changes in the gel. The concept is illustrated in a series of Suzuki-Miyaura cross-coupling reactions. The demonstrated catalyst activity variations depend on the structure of the gel.

  3. Ontology-based data integration from heterogeneous urban systems: A knowledge representation framework for smart cities

    NARCIS (Netherlands)

    Psyllidis, A.

    2015-01-01

    This paper presents a novel knowledge representation framework for smart city planning and management that enables the semantic integration of heterogeneous urban data from diverse sources. Currently, the combination of information across city agencies is cumbersome, as the increasingly available da

  4. Using Heterogeneous Linguistic Knowledge in Local Coherence Identification for Information Retrieval.

    Science.gov (United States)

    Chan, Samuel W. K.

    2000-01-01

    Discusses natural language processing and proposes a novel approach to automatic text segmentation using heterogeneous linguistic knowledge and cluster algorithms. Represents the diversity of textual relations in a discourse network in order to analyze the linguistic bonds and determine the degree of coherence that a text may exhibit. (Author/LRW)

  5. Chaos suppression and desynchronization phenomena in periodically coupled pendula subjected to localized heterogeneous forces

    Energy Technology Data Exchange (ETDEWEB)

    Chacon, R. [Departamento de Fisica Aplicada, Escuela de Ingenierias Industriales, Universidad de Extremadura, Apartado Postal 382, E-06071 Badajoz (Spain)], E-mail: rchacon@unex.es; Martinez, P.J. [Departamento de Fisica Aplicada, E.U.I.T.I., Universidad de Zaragoza, Spain and Instituto de Ciencia de Materiales de Aragon, CSIC-Universidad de Zaragoza, E-50009 Zaragoza (Spain); Martinez, J.A. [Departamento de Ingenieria Electrica, Electronica y Automatica, E.P.S., Universidad de Castilla-La Mancha, E-02071 Albacete (Spain); Lenci, S. [Dipartimento di Architettura, Costruzioni e Strutture, Universita Politecnica delle Marche, via Brecce Bianche, 60131 Ancona (Italy)

    2009-11-30

    The suppressory effects of localized heterogeneous periodic pulses on the chaotic behaviour of sinusoidally coupled nonlinear pendula are studied. We assume that when the pendula are driven synchronously, i.e., all driving pulses have the same waveform, the chains display chaotic dynamics. It is shown that decreasing the impulse transmitted by the pulses of a minimal number of pendula results in regularization with the whole array exhibiting frequency synchronization over a wide range of coupling periods. These findings demonstrate that decreasing the impulse transmitted by localized external forces can tame chaos and lead to frequency-locked states in networks of periodically coupled dissipative systems.

  6. Chimera and chimera-like states in populations of nonlocally coupled homogeneous and heterogeneous chemical oscillators

    Science.gov (United States)

    Nkomo, Simbarashe; Tinsley, Mark R.; Showalter, Kenneth

    2016-09-01

    Chimera and chimera-like states are characterized in populations of photochemically coupled Belousov-Zhabotinsky (BZ) oscillators. Simple chimeras and chimera states with multiple and traveling phase clusters, phase-slip behavior, and chimera-like states with phase waves are described. Simulations with a realistic model of the discrete BZ system of populations of homogeneous and heterogeneous oscillators are compared with each other and with experimental behavior.

  7. Explicit Analytical Solutions of Coupled Fluid Flow Transfer Equation in Heterogeneous Porous Media

    Institute of Scientific and Technical Information of China (English)

    张娜; 蔡睿贤

    2002-01-01

    Explicit analytical solutions are presented for the coupled fluid flow transfer equation in heterogeneous porous media. These analytical solutions are useful for their description of actual flow fields and as benchmark solutions to check the rapidly developing numerical calculations and to study various computational methods such as the discrete approximations of the governing equations and grid generation methods. In addition, some novel mathematical methods are used in the analyses.

  8. Knowledge, attitude, and practices of infertility among Saudi couples

    Directory of Open Access Journals (Sweden)

    Abolfotouh MA

    2013-07-01

    Full Text Available Mostafa A Abolfotouh,1 Abdullah A Alabdrabalnabi,2 Rehab B Albacker,3 Umar A Al-Jughaiman,4 Samar N Hassan5 1King Abdullah International Medical Research Center (KAIMRC, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia; 2University of Dammam, College of Medicine, Dammam, Saudi Arabia; 3King Saud University, College of Medicine, Riyadh, Saudi Arabia; 4King Faisal University, College of Medicine, Dammam, Saudi Arabia; 5Division of Reproductive Medicine, Department of Obstetrics and Gynecology, King Abdulaziz Medical City, Riyadh, Saudi Arabia Introduction: Infertility places a huge psychological burden on infertile couples, especially for women. Greater knowledge of the factors affecting fertility may help to decrease the incidence of infertility by allowing couples to avoid certain risk factors. The aim of our study was (1 to assess the knowledge and attitudes of infertile and fertile Saudi participants on infertility, possible risk factors, and social consequences; and (2 to determine the practices of infertile Saudi couples to promote their fertility before having them attend an in vitro fertilization (IVF clinic. Methods and materials: We conducted a cross-sectional study on 277 fertile participants from outpatient clinics and 104 infertile patients from the IVF clinic at King Abdulaziz Medical City between June 24, 2012 and July 4, 2012, using a previously validated interview questionnaire. Descriptive and analytical statistics were applied with a significance threshold of P ≤ 0.05. Results: A generally poor level of knowledge (59% and a neutral attitude (76% toward infertility were reported by participants. Mistaken beliefs commonly held by the study participants regarding the causes of infertility were Djinns and supernatural causes (58.8%, black magic (67.5%, intrauterine devices (71.3%, and contraceptive pills (42.9%. The healer/Sheikh was reported as the primary and secondary preference for infertility

  9. Supporting and Enhancing Development of Heterogeneous Ecological Knowledge among Resource Users in a Kenyan Seascape

    Directory of Open Access Journals (Sweden)

    Beatrice Irene. Crona

    2006-06-01

    Full Text Available The heterogeneous nature of even small communities has been acknowledged, yet how such heterogeneity is reflected in local ecological knowledge (LEK among groups of resource users in a community is poorly studied. This study examines the ecological knowledge held by fisher groups using differing gear and operating in different subsystems of a coastal seascape in south Kenya. Knowledge is compared to that of nonfishing groups and is analyzed with respect to the scales of ecological processes and disturbances affecting the ecosystem to identify mismatches of scale between local knowledge and ecological processes, as well as points of convergence upon which emerging scientific and local community information exchange can build and develop. Results reveal significant differences in the level and content of ecological knowledge among occupational categories with respect to the scale and nature of ecological interactions in the seascape. Nonfishing related groups were marked by consistently low levels of knowledge and understanding of all seascape components and processes. Gear-defined fisher groups appeared linked, through fishing methods, to specific functional groups defined by trophic level, although acknowledgment among users of trophic links and ecosystem effects were not always apparent. Knowledge appeared to be largely related to maximization of resource extraction rather than reflecting deep understanding of ecological processes and causal links. Demographic changes and erosion of traditional management systems may partly explain this. Based on the results it is suggested that future investments geared at enhancing socioeconomic standards, e.g., through investment in improved gear, run the risk of further propelling the system down the poverty trap through habitat degradation and stock depletion, if not simultaneously combined with support for development and enhancement of existing LEK.

  10. A Semantic-based Clustering Method to Build Domain Ontology from Multiple Heterogeneous Knowledge Sources

    Institute of Scientific and Technical Information of China (English)

    LING Ling; HU Yu-jin; WANG Xue-lin; LI Cheng-gang

    2006-01-01

    In order to improve the efficiency of ontology construction from heterogeneous knowledge sources, a semantic-based approach is presented. The ontology will be constructed with the application of cluster technique in an incremental way.Firstly, terms will be extracted from knowledge sources and congregate a term set after pretreat-ment. Then the concept set will be built via semantic-based clustering according to semanteme of terms provided by WordNet. Next, a concept tree is constructed in terms of mapping rules between semanteme relationships and concept relationships. The semi-automatic approach can avoid non-consistence due to knowledge engineers having different understanding of the same concept and the obtained ontology is easily to be expanded.

  11. Transmural Heterogeneity and Remodeling of Ventricular Excitation-Contraction Coupling in Human Heart Failure

    Science.gov (United States)

    Lou, Qing; Fedorov, Vadim V.; Glukhov, Alexey V.; Moazami, Nader; Fast, Vladimir G.; Efimov, Igor R.

    2011-01-01

    Background Excitation-contraction (EC) coupling is altered in the end-stage heart failure (HF). However, spatial heterogeneity of this remodeling has not been established at the tissue level in failing human heart. The objective is to study functional remodeling of EC coupling and calcium handling in failing and nonfailing human hearts. Methods and Results We simultaneously optically mapped action potentials (AP) and calcium transients (CaT) in coronary-perfused left ventricular wedge preparations from nonfailing (n = 6) and failing (n = 5) human hearts. Our major findings are: (1) CaT duration minus AP duration was longer at sub-endocardium in failing compared to nonfailing hearts during bradycardia (40 beats/min). (2) The transmural gradient of CaT duration was significantly smaller in failing hearts compared with nonfailing hearts at fast pacing rates (100 beats/min). (3) CaT in failing hearts had a flattened plateau at the midmyocardium; and exhibited a “two-component” slow rise at sub-endocardium in three failing hearts. (4) CaT relaxation was slower at sub-endocardium than that at sub-epicardium in both groups. Protein expression of sarcoplasmic reticulum Ca2+-ATPase 2a (SERCA2a) was lower at sub-endocardium than that at sub-epicardium in both nonfailing and failing hearts. SERCA2a protein expression at sub-endocardium was lower in hearts with ischemic cardiomyopathy compared with nonischemic cardiomyopathy. Conclusions For the first time, we present direct experimental evidence of transmural heterogeneity of EC coupling and calcium handling in human hearts. End-stage HF is associated with the heterogeneous remodeling of EC coupling and calcium handling. PMID:21502574

  12. Heterogeneity and weak coupling may explain the synchronization characteristics of cells in the arterial wall.

    Science.gov (United States)

    Jacobsen, Jens Christian Brings; Aalkjaer, Christian; Matchkov, Vladimir V; Nilsson, Holger; Freiberg, Jacob J; Holstein-Rathlou, Niels-Henrik

    2008-10-13

    Vascular smooth muscle cells (SMCs) exhibit different types of calcium dynamics. Static vascular tone is associated with unsynchronized calcium waves and the developed force depends on the number of recruited cells. Global calcium transients synchronized among a large number of cells cause rhythmic development of force known as vasomotion. We present experimental data showing a considerable heterogeneity in cellular calcium dynamics in the vascular wall. In stimulated vessels, some SMCs remain quiescent, whereas others display waves of variable frequency. At the onset of vasomotion, all SMCs are enrolled into synchronized oscillation. Simulations of coupled SMCs show that the experimentally observed cellular recruitment, the presence of quiescent cells and the variation in oscillation frequency may arise if the cell population is phenotypically heterogeneous. In this case, quiescent cells can be entrained at the onset of vasomotion by the collective driving force from the synchronized oscillations in the membrane potential of the surrounding cells. Partial synchronization arises with an increase in the concentration of cyclic guanosine monophosphate, but in a heterogeneous cell population complete synchronization also requires a high-conductance pathway that provides strong coupling between the cells.

  13. What drives developmental change in adolescent disclosure and maternal knowledge? Heterogeneity in within-family processes.

    Science.gov (United States)

    Keijsers, Loes; Voelkle, Manuel C; Maciejewski, Dominique; Branje, Susan; Koot, Hans; Hiemstra, Marieke; Meeus, Wim

    2016-12-01

    This study aimed to gain a better understanding of the normative declines in adolescent disclosure and maternal knowledge over the course of adolescence, by assessing the underlying monitoring processes. Multilevel structural equation models were applied to 15 assessments among 479 families across 5 years (13 years at T1, 57% boys, 11% low socioeconomic status). Developmental declines in mother-perceived disclosure and knowledge were observed, which were partially explained by processes operating at the level of the family unit. On average, mothers were more knowledgeable in weeks with more disclosure and more solicitation, and adolescent disclosure was higher in weeks with more maternal solicitation and less control. The effect sizes and even the directions of these within-family correlations varied between families, however. This heterogeneity was partially explained by the level of maternal control and adolescent disclosure, and by the families' socioeconomic status. Within-family fluctuations in knowledge and disclosure were also correlated with fluctuations in relationship quality and adolescent and mother mood. Overall, these within-family processes explained up to 14% of the normative developmental decline in disclosure and 19% of the decline in knowledge. This study thus suggests that a wide variety in monitoring processes may drive normative declines in adolescent disclosure and maternal knowledge. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  14. Heterogeneous ice nucleation controlled by the coupling of surface crystallinity and surface hydrophilicity

    CERN Document Server

    Bi, Yuanfei; Li, Tianshu

    2015-01-01

    The microscopic mechanisms controlling heterogeneous ice nucleation are complex and remain poorly understood. Although good ice nucleators are generally believed to match ice lattice and to bind water, counter examples are often identified. Here we show, by advanced molecular simulations, that the heterogeneous nucleation of ice on graphitic surface is controlled by the coupling of surface crystallinity and surface hydrophilicity. Molecular level analysis reveals that the crystalline graphitic lattice with an appropriate hydrophilicity may indeed template ice basal plane by forming a strained ice layer, thus significantly enhancing its ice nucleation efficiency. Remarkably, the templating effect is found to transit from within the first contact layer of water to the second as the hydrophilicity increases, yielding an oscillating distinction between the crystalline and amorphous graphitic surfaces in their ice nucleation efficiencies. Our study sheds new light on the long-standing question of what constitutes ...

  15. Relational Network for Knowledge Discovery through Heterogeneous Biomedical and Clinical Features

    Science.gov (United States)

    Chen, Huaidong; Chen, Wei; Liu, Chenglin; Zhang, Le; Su, Jing; Zhou, Xiaobo

    2016-07-01

    Biomedical big data, as a whole, covers numerous features, while each dataset specifically delineates part of them. “Full feature spectrum” knowledge discovery across heterogeneous data sources remains a major challenge. We developed a method called bootstrapping for unified feature association measurement (BUFAM) for pairwise association analysis, and relational dependency network (RDN) modeling for global module detection on features across breast cancer cohorts. Discovered knowledge was cross-validated using data from Wake Forest Baptist Medical Center’s electronic medical records and annotated with BioCarta signaling signatures. The clinical potential of the discovered modules was exhibited by stratifying patients for drug responses. A series of discovered associations provided new insights into breast cancer, such as the effects of patient’s cultural background on preferences for surgical procedure. We also discovered two groups of highly associated features, the HER2 and the ER modules, each of which described how phenotypes were associated with molecular signatures, diagnostic features, and clinical decisions. The discovered “ER module”, which was dominated by cancer immunity, was used as an example for patient stratification and prediction of drug responses to tamoxifen and chemotherapy. BUFAM-derived RDN modeling demonstrated unique ability to discover clinically meaningful and actionable knowledge across highly heterogeneous biomedical big data sets.

  16. Relational Network for Knowledge Discovery through Heterogeneous Biomedical and Clinical Features.

    Science.gov (United States)

    Chen, Huaidong; Chen, Wei; Liu, Chenglin; Zhang, Le; Su, Jing; Zhou, Xiaobo

    2016-07-18

    Biomedical big data, as a whole, covers numerous features, while each dataset specifically delineates part of them. "Full feature spectrum" knowledge discovery across heterogeneous data sources remains a major challenge. We developed a method called bootstrapping for unified feature association measurement (BUFAM) for pairwise association analysis, and relational dependency network (RDN) modeling for global module detection on features across breast cancer cohorts. Discovered knowledge was cross-validated using data from Wake Forest Baptist Medical Center's electronic medical records and annotated with BioCarta signaling signatures. The clinical potential of the discovered modules was exhibited by stratifying patients for drug responses. A series of discovered associations provided new insights into breast cancer, such as the effects of patient's cultural background on preferences for surgical procedure. We also discovered two groups of highly associated features, the HER2 and the ER modules, each of which described how phenotypes were associated with molecular signatures, diagnostic features, and clinical decisions. The discovered "ER module", which was dominated by cancer immunity, was used as an example for patient stratification and prediction of drug responses to tamoxifen and chemotherapy. BUFAM-derived RDN modeling demonstrated unique ability to discover clinically meaningful and actionable knowledge across highly heterogeneous biomedical big data sets.

  17. Open access to large scale datasets is needed to translate knowledge of cancer heterogeneity into better patient outcomes.

    Directory of Open Access Journals (Sweden)

    Andrew H Beck

    2015-02-01

    Full Text Available In this guest editorial, Andrew Beck discusses the importance of open access to big data for translating knowledge of cancer heterogeneity into better outcomes for cancer patients.

  18. On the Representation of Heterogeneity in Land-Surface-Atmosphere Coupling

    Science.gov (United States)

    de Vrese, Philipp; Schulz, Jan-Peter; Hagemann, Stefan

    2016-07-01

    A realistic representation of processes that are not resolved by the model grid is one of the key challenges in Earth-system modelling. In particular, the non-linear nature of processes involved makes a representation of the link between the atmosphere and the land surface difficult. This is especially so when the land surface is horizontally strongly heterogeneous. In the majority of present day Earth system models two strategies are pursued to couple the land surface and the atmosphere. In the first approach, surface heterogeneity is not explicitly accounted for, instead effective parameters are used to represent the entirety of the land surface in a model's grid box (parameter-aggregation). In the second approach, subgrid-scale variability at the surface is explicitly represented, but it is assumed that the blending height is located below the lowest atmospheric model level (simple flux-aggregation). Thus, in both approaches the state of the atmosphere is treated as being horizontally homogeneous within a given grid box. Based upon the blending height concept, an approach is proposed that allows for a land-surface-atmosphere coupling in which horizontal heterogeneity is considered not only at the surface, but also within the lowest layers of the atmosphere (the VERTEX scheme). Below the blending height, the scheme refines the turbulent mixing process with respect to atmospheric subgrid fractions, which correspond to different surface features. These subgrid fractions are not treated independently of each other, since an explicit horizontal component is integrated into the turbulent mixing process. The scheme was implemented into the JSBACH model, the land component of the Max Planck Institute for Meteorology's Earth-system model, when coupled to the atmospheric general circulation model ECHAM. The single-column version of the Earth system model is used in two example cases in order to demonstrate how the effects of surface heterogeneity are transferred into the

  19. Heterogeneity and weak coupling may explain the synchronization characteristics of cells in the arterial wall

    DEFF Research Database (Denmark)

    Jacobsen, Jens Christian Brings; Aalkjær, Christian; Matchkov, Vladimir

    2008-01-01

    Vascular smooth muscle cells (SMCs) exhibit different types of calcium dynamics. Static vascular tone is associated with unsynchronized calcium waves and the developed force depends on the number of recruited cells. Global calcium transients synchronized among a large number of cells cause rhythmic...... are enrolled into synchronized oscillation.Simulations of coupled SMCs show that the experimentally observed cellular recruitment, the presence of quiescent cells and the variation in oscillation frequency may arise if the cell population is phenotypically heterogeneous. In this case, quiescent cells can...

  20. Synchronization in interacting populations of heterogeneous oscillators with time-varying coupling.

    Science.gov (United States)

    So, Paul; Cotton, Bernard C; Barreto, Ernest

    2008-09-01

    In many networks of interest (including technological, biological, and social networks), the connectivity between the interacting elements is not static, but changes in time. Furthermore, the elements themselves are often not identical, but rather display a variety of behaviors, and may come in different classes. Here, we investigate the dynamics of such systems. Specifically, we study a network of two large interacting heterogeneous populations of limit-cycle oscillators whose connectivity switches between two fixed arrangements at a particular frequency. We show that for sufficiently high switching frequency, this system behaves as if the connectivity were static and equal to the time average of the switching connectivity. We also examine the mechanisms by which this fast-switching limit is approached in several nonintuitive cases. The results illuminate novel mechanisms by which synchronization can arise or be thwarted in large populations of coupled oscillators with nonstatic coupling.

  1. Coupling knowledge and action in the management context

    DEFF Research Database (Denmark)

    Mazza, Carmelo; Strandgaard Pedersen, Jesper; Alvarez, José Luis

    2003-01-01

    In the last decade, scholarly interest has been mainly attracted on the nature of knowledge,mechanisms of knowledge production and the transformation of the institutions diffusingknowledge. Most of these studies share the underlying hypotheses that management knowledge`travels', as a package, from...... to outline the process of knowledge consumption. Wedescribe how sources of knowledge are selected, knowledge is acquired and consumed by assumingthat managers are active consumer of management knowledge. Then, we construct the processlinking the flows of management knowledge in organizations and the flows...

  2. Heterogeneous response of different tumor cell lines to methotrexate-coupled nanoparticles in presence of hyperthermia.

    Science.gov (United States)

    Stapf, Marcus; Pömpner, Nadine; Teichgräber, Ulf; Hilger, Ingrid

    2016-01-01

    Today, the therapeutic efficacy of cancer is restricted by the heterogeneity of the response of tumor cells to chemotherapeutic drugs. Since those therapies are also associated with severe side effects in nontarget organs, the application of drugs in combination with nanocarriers for targeted therapy has been suggested. Here, we sought to assess whether the coupling of methotrexate (MTX) to magnetic nanoparticles (MNP) could serve as a valuable tool to circumvent the heterogeneity of tumor cell response to MTX by the combined treatment with hyperthermia. To this end, we investigated five breast cancer cell lines of different origin and with different mutational statuses, as well as a bladder cancer cell line in terms of their response to exposure to MTX as a free drug or after its coupling to MNP as well as in presence/absence of hyperthermia. We also assessed whether the effects could be connected to the cell line-specific expression of proteins related to the uptake and efflux of MTX and MNP. Our results revealed a very heterogeneous and cell line-dependent response to an exposure with MTX-coupled MNP (MTX-MNP), which was almost comparable to the efficacy of free MTX in the same cell line. Moreover, a cell line-specific and preferential uptake of MTX-MNP compared with MNP alone was found (probably by receptor-mediated endocytosis), agreeing with the observed cytotoxic effects. Opposed to this, the expression pattern of several cell membrane transport proteins noted for MTX uptake and efflux was only by tendency in agreement with the cellular toxicity of MTX-MNP in different cell lines. Higher cytotoxic effects were achieved by exposing cells to a combination of MTX-MNP and hyperthermal treatment, compared with MTX or thermo-therapy alone. However, the heterogeneity in the response of the tumor cell lines to MTX could not be completely abolished - even after its combination with MNP and/or hyperthermia - and the application of higher thermal dosages might be

  3. Quorum Sensing in Populations of Spatially Extended Chaotic Oscillators Coupled Indirectly via a Heterogeneous Environment

    Science.gov (United States)

    Li, Bing-Wei; Cao, Xiao-Zhi; Fu, Chenbo

    2017-05-01

    Many biological and chemical systems could be modeled by a population of oscillators coupled indirectly via a dynamical environment. Essentially, the environment by which the individual element communicates with each other is heterogeneous. Nevertheless, most of previous works considered the homogeneous case only. Here we investigated the dynamical behaviors in a population of spatially distributed chaotic oscillators immersed in a heterogeneous environment. Various dynamical synchronization states (such as oscillation death, phase synchronization, and complete synchronized oscillation) as well as their transitions were explored. In particular, we uncovered a non-traditional quorum sensing transition: increasing the population density leaded to a transition from oscillation death to synchronized oscillation at first, but further increasing the density resulted in degeneration from complete synchronization to phase synchronization or even from phase synchronization to desynchronization. The underlying mechanism of this finding was attributed to the dual roles played by the population density. What's more, by treating the environment as another component of the oscillator, the full system was then effectively equivalent to a locally coupled system. This fact allowed us to utilize the master stability functions approach to predict the occurrence of complete synchronization oscillation, which agreed with that from the direct numerical integration of the system. The potential candidates for the experimental realization of our model were also discussed.

  4. Heterogeneous interplate coupling along the Nankai Trough, Japan, detected by GPS-acoustic seafloor geodetic observation

    Science.gov (United States)

    Yokota, Yusuke; Ishikawa, Tadashi; Sato, Mariko; Watanabe, Shun-ichi; Saito, Hiroaki; Ujihara, Naoto; Matsumoto, Yoshihiro; Toyama, Shin-ichi; Fujita, Masayuki; Yabuki, Tetsuichiro; Mochizuki, Masashi; Asada, Akira

    2015-12-01

    The recurring devastating earthquake that occurs in the Nankai Trough subduction zone between the Philippine Sea plate and the Eurasian plate has the potential to cause an extremely dangerous natural disaster in the foreseeable future. Many previous studies have assumed interplate-coupling ratios for this region along the trench axis using onshore geodetic data in order to understand this recursive event. However, the offshore region that has the potential to drive a devastating tsunami cannot be resolved sufficiently because the observation network is biased to the land area. Therefore, the Hydrographic and Oceanographic Department of Japan constructed a geodetic observation network on the seafloor along the Nankai Trough using a GPS-acoustic combination technique and has used it to observe seafloor crustal movements directly above the Nankai Trough subduction zone. We have set six seafloor sites and cumulated enough data to determine the displacement rate from 2006 to January 2011. Our seafloor geodetic observations at these sites revealed a heterogeneous interplate coupling that has three particular features. The fast displacement rates observed in the easternmost area indicate strong interplate coupling (>75%) around not only the future Tokai earthquake source region but also the Paleo-Zenisu ridge. The slow displacement rates near the trench axis in the Kumano-nada Sea, a shallow part of the 1944 Tonankai earthquake source region, show a lower coupling ratio (50% to 75%). The slow displacement rate observed in the area shallower than the 1946 Nankaido earthquake source region off Cape Muroto-zaki reflects weakening interplate coupling (about 50%) probably due to a subducting seamount. Our observations above the subducting ridge and seamount indicate that the effect of a subducting seamount on an interplate-coupling region depends on various conditions such as the geometry of the seamount and the friction parameters on the plate boundary.

  5. Coupling knowledge and action in the management context

    DEFF Research Database (Denmark)

    Mazza, Carmelo; Strandgaard Pedersen, Jesper; Alvarez, José Luis

    2003-01-01

    . First, a framework is proposed to describe managementknowledge consumption. Second, we outline the process linking consumed knowledge with actualmanagerial action. Third, the impact of this perspective on the structure of the institutions diffusingknowledge and on the idea of what is needed to make...... to outline the process of knowledge consumption. Wedescribe how sources of knowledge are selected, knowledge is acquired and consumed by assumingthat managers are active consumer of management knowledge. Then, we construct the processlinking the flows of management knowledge in organizations and the flows...... or routines (e.g. abudgetary procedure, an organizational process, etc.). So, to re-embed knowledge in new contexts,managers have to mobilize resources and build consensus on the specific courses of action.By assuming this process, two consequences are derived: first, the dis...

  6. Uncertainty Updating in the Description of Coupled Heat and Moisture Transport in Heterogeneous Materials

    CERN Document Server

    Kucerova, Anna

    2011-01-01

    To assess the durability of structures, heat and moisture transport need to be analyzed. To provide a reliable estimation of heat and moisture distribution in a certain structure, one needs to include all available information about the loading conditions and material parameters. Moreover, the information should be accompanied by a corresponding evaluation of its credibility. Here, the Bayesian inference is applied to combine different sources of information, so as to provide a more accurate estimation of heat and moisture fields [1]. The procedure is demonstrated on the probabilistic description of heterogeneous material where the uncertainties consist of a particular value of individual material characteristic and spatial fluctuations. As for the heat and moisture transfer, it is modelled in coupled setting [2].

  7. Localization in covariance matrices of coupled heterogenous Ornstein-Uhlenbeck processes.

    Science.gov (United States)

    Barucca, Paolo

    2014-12-01

    We define a random-matrix ensemble given by the infinite-time covariance matrices of Ornstein-Uhlenbeck processes at different temperatures coupled by a Gaussian symmetric matrix. The spectral properties of this ensemble are shown to be in qualitative agreement with some stylized facts of financial markets. Through the presented model formulas are given for the analysis of heterogeneous time series. Furthermore evidence for a localization transition in eigenvectors related to small and large eigenvalues in cross-correlations analysis of this model is found, and a simple explanation of localization phenomena in financial time series is provided. Finally we identify both in our model and in real financial data an inverted-bell effect in correlation between localized components and their local temperature: high- and low-temperature components are the most localized ones.

  8. Thermochemical flows couple the Earth's inner core growth to mantle heterogeneity.

    Science.gov (United States)

    Aubert, Julien; Amit, Hagay; Hulot, Gauthier; Olson, Peter

    2008-08-07

    Seismic waves sampling the top 100 km of the Earth's inner core reveal that the eastern hemisphere (40 degrees E-180 degrees E) is seismically faster, more isotropic and more attenuating than the western hemisphere. The origin of this hemispherical dichotomy is a challenging problem for our understanding of the Earth as a system of dynamically coupled layers. Previously, laboratory experiments have established that thermal control from the lower mantle can drastically affect fluid flow in the outer core, which in turn can induce textural heterogeneity on the inner core solidification front. The resulting texture should be consistent with other expected manifestations of thermal mantle control on the geodynamo, specifically magnetic flux concentrations in the time-average palaeomagnetic field over the past 5 Myr, and preferred eddy locations in flows imaged below the core-mantle boundary by the analysis of historical geomagnetic secular variation. Here we show that a single model of thermochemical convection and dynamo action can account for all these effects by producing a large-scale, long-term outer core flow that couples the heterogeneity of the inner core with that of the lower mantle. The main feature of this thermochemical 'wind' is a cyclonic circulation below Asia, which concentrates magnetic field on the core-mantle boundary at the observed location and locally agrees with core flow images. This wind also causes anomalously high rates of light element release in the eastern hemisphere of the inner core boundary, suggesting that lateral seismic anomalies at the top of the inner core result from mantle-induced variations in its freezing rate.

  9. Heterogeneity in Ethnoecological Knowledge and Management of Medicinal Plants in the Himalayas of Nepal: Implications for Conservation

    Directory of Open Access Journals (Sweden)

    Yildiz Aumeeruddy-Thomas

    2004-12-01

    Full Text Available The importance accorded to ethnoecological knowledge for suggesting new paths in scientific research, understanding ecological processes, and designing sustainable management of natural resources has grown in recent years. However, variation in knowledge and practices, both within and across cultures, has not been given much attention in resource management nor in developing scientific understanding of the ecological status of key resources. In this paper, we discuss the heterogeneity and complexity of local ecological knowledge in relation to its practical and institutional context with respect to management of Himalayan medicinal plants. We show factors affecting this variation, and discuss how knowledge is put into action. We assessed variation in knowledge relating to the diversity of medicinal plant species, their distribution, medicinal uses, biological traits, ecology, and management within and between two culturally different social groups living in villages located in the Shey-Phoksundo National Park and its buffer zone in northwestern Nepal. Heterogeneity in levels of knowledge and in practices both within and between these groups corresponds to differences in level of specialization in relation to medicinal plants, to socio-cultural and institutional contexts, and to extra-local factors that govern people's activities. We argue that understanding the heterogeneity of knowledge and practices within a given area is crucial to design management practices that build on the intricate links between knowledge, practices, and institutional context. It is also important to develop ecological studies that will best inform management.

  10. [Patient education: between complex knowledge, educators, heterogeneous learners and multiple contexts].

    Science.gov (United States)

    Balcou-Debussche, Maryvette

    2012-09-01

    Therapeutic patient education questions the links between medical and social sciences through epistemological, praxeological, and ethical issues. Its development in France and abroad necessary invites to consider the complexity of the particularities and variations of numerous contexts. The present contribution examines the theoretical foundations and the conditions required for the development of integrative learning situations, which involve both persons with chronic diseases and educators who have beneficiated from diverse socialisations. These learning situations have been worked out across three distinct stages: prerequisite analysis of specific knowledge at stake and of learners' representations preceding the thorough design of procedures that can yield results with heterogeneous individuals of various cultural and social origins. More than ten thousands persons have beneficiated from these learning situations courses. Results underline the development of emerging social dynamics and organisations beyond the learning process. These analysis invite to the reflection on social and contextual dimensions of learning, on the access to knowledge for persons with chronic diseases and the opportunities to develop the approach by diverse educators and trainers from various areas.

  11. In situ generated hypoiodous acid in an efficient and heterogeneous catalytic system for the homo-oxidative coupling of thiols

    Directory of Open Access Journals (Sweden)

    Ghorbani-Choghamarani Arash

    2013-01-01

    Full Text Available Supported hydrogen peroxide on polyvinylpolypyrrolidone (PVPH2O2, silica sulfuric acid (SiO2-OSO3H and catalytic amounts of potassium iodide (KI has been developed as a heterogeneous medium for the rapid oxidative coupling of thiols into symmetrical homodisulfides. This oxidizing system proceeds under extremely mild conditions and gives no other oxidized side products.

  12. Information Technology and Knowledge Processes : - an Uneasy Couple?

    DEFF Research Database (Denmark)

    Brøndsted, J.; Christiansen, N.; Nicolajsen, Hanne Westh

    2001-01-01

    -technical perspective taking the interconnected relationship between knowledge and knowing into account. We explore the role of IT in knowledge processes by studying three different practices. These practices are a pre-defense of a Ph.D. dissertation using a video conferencing system in the area of geophysics......, a pharmaceutical development process and a practice of system testing in the telecommunication industry. Through the analysis we are showing that IT is an integrated part of those practices and IT can take on at least three different and intertwined types of role which are mediating communication, repository...

  13. Survey the Effect of Pre-marriage Counseling on Knowledge and Attitudes Couple in Yazd

    Directory of Open Access Journals (Sweden)

    ss Mazloomi mahmodabad

    2016-07-01

    Full Text Available Abstract Introduction : Holding true premarital counseling courses helps to couples to acquire the necessary knowledge in the field of reproductive health issues. The aim of this study was determination of effect of pre-marriage counseling on knowledge and attitudes couple in Yazd. Methods: This was an semi experimental and pre and post study In which 200 couples participating in premarital counseling courses were selected randomly. Finally, the data were analysed by SPSS18 software and t-test and ANOVA statistical tests. Results: The data showen that  couples before attending in counseling courses have acquired respectively 37.6%  and 48.1%  and after training respectively 65.1% and 57.6% from knowledge and attitude scores. Also mean score of knowledge and attitude according to sex, education level and occupation were statistically significant (P≤0.05. Conclusion: Considering to small change of attitude couples, it is suggested after counseling classes are given the opportunity into couple that express your questions privately. Also to achieve a relatively stable behavior in young couples and promoting their health levels, must besides holding training courses before marriage, pay more attention to the quality of these courses. 

  14. Homogenization of heterogeneously coupled bistable ODE's - applied to excitation waves in pancreatic islets of Langerhans

    DEFF Research Database (Denmark)

    Pedersen, Morten Gram

    2004-01-01

    We consider a lattice of coupled identical differential equations. The coupling is between nearest neighbors and of resistance type, but the strength of coupling varies from site to site. Such a lattice can, for example, model an islet of Langerhans, where the sites in the lattice model individua...

  15. Homogenization of heterogeneously coupled bistable ODE's - applied to excitation waves in pancreatic islets of Langerhans

    DEFF Research Database (Denmark)

    Pedersen, Morten Gram

    2004-01-01

    We consider a lattice of coupled identical differential equations. The coupling is between nearest neighbors and of resistance type, but the strength of coupling varies from site to site. Such a lattice can, for example, model an islet of Langerhans, where the sites in the lattice model individua...

  16. The EDEN-IW ontology model for sharing knowledge and water quality data between heterogenous databases

    DEFF Research Database (Denmark)

    Stjernholm, M.; Poslad, S.; Zuo, L.;

    2004-01-01

    The Environmental Data Exchange Network for Inland Water (EDEN-IW) project's main aim is to develop a system for making disparate and heterogeneous databases of Inland Water quality more accessible to users. The core technology is based upon a combination of: ontological model to represent a Sema...

  17. Quantifying impacts of coupled chemical and physical heterogeneity on water quality evolution during Aquifer Storage and Recovery

    Science.gov (United States)

    Deng, H.; Descourvieres, C.; Seibert, S.; Harris, B.; Atteia, O.; Siade, A. J.; Prommer, H.

    2014-12-01

    Aquifer storage and recovery (ASR) is an important water management option in water-scarce regions. During wet periods surplus water is injected into suitable aquifers for storage and later recovery. ASR sites are, however, also ideal natural laboratories that provide opportunities for studying coupled physical and geochemical processes and water quality evolution at field-scale under well-controlled hydrological conditions. In this study, we use reactive transport modelling to assess the impacts of physical and chemical heterogeneities on the water quality evolution during the injection of oxic surface water into the anoxic, pyrite-bearing Leederville aquifer in Perth, Western Australia. Physical heterogeneity was identified from geophysical well logs and time lapse temperature logs. Those data were used to define the spatial, depth-varying alternation of three lithofacies (sandstone, siltstone and clay). Chemical heterogeneity was incorporated through distinct chemical zones, based on data derived from a comprehensive pre-trial geochemical characterization and from dedicated laboratory respirometer experiments. Calibration of flow and conservative transport parameters was constrained by the spatially varying measured chloride breakthrough behavior. Subsequent reactive transport modeling discerned the key geochemical processes that affected the water quality evolution during ASR. Clearly identified processes included oxidation of pyrite, mineralization of sedimentary organic carbon, ion exchange, dissolution of calcite and precipitation of ferrihydrite and siderite. We use the calibrated model to analyze the individual and the combined effects of the physical and chemical heterogeneities on the chemical composition of the recovered water during ASR.

  18. Knowledge of HIV serodiscordance, transmission, and prevention among couples in Durban, South Africa.

    Directory of Open Access Journals (Sweden)

    William Kilembe

    Full Text Available Couples' voluntary HIV counseling and testing (CVCT significantly decreases HIV transmission within couples, the largest risk group in sub-Saharan Africa, but it is not currently offered in most HIV testing facilities. To roll out such an intervention, understanding locale-specific knowledge barriers is critical. In this study, we measured knowledge of HIV serodiscordance, transmission, and prevention before and after receipt of CVCT services in Durban.Pre- and post-CVCT knowledge surveys were administered to a selection of individuals seeking CVCT services.Changes in knowledge scores were assessed with McNemar Chi-square tests for balanced data and generalized estimating equation methods for unbalanced data.The survey included 317 heterosexual black couples (634 individuals who were primarily Zulu (87%, unemployed (47%, and had at least a secondary level education (78%. 28% of couples proved to be discordant. Only 30% of individuals thought serodiscordance between couples was possible pre-CVCT compared to 95% post-CVCT. One-third thought there was at least one benefit of CVCT pre-CVCT, increasing to 96% post-CVCT. Overall, there were positive changes in knowledge about HIV transmission and prevention. However, many respondents thought all HIV positive mothers give birth to babies with AIDS (64% pre-CVCT, 59% post-CVCT and that male circumcision does not protect negative men against HIV (70% pre-CVCT, 67% post-CVCT.CVCT was well received and was followed by improvements in understanding of discordance, the benefits of joint testing, and HIV transmission. Country-level health messaging would benefit from targeting gaps in knowledge about serodiscordance, vertical transmission, and male circumcision.

  19. Regional seismic wavefield computation on a 3-D heterogeneous Earth model by means of coupled traveling wave synthesis

    Science.gov (United States)

    Pollitz, F.F.

    2002-01-01

    I present a new algorithm for calculating seismic wave propagation through a three-dimensional heterogeneous medium using the framework of mode coupling theory originally developed to perform very low frequency (f seismic wavefield computation. It is a Greens function approach for multiple scattering within a defined volume and employs a truncated traveling wave basis set using the locked mode approximation. Interactions between incident and scattered wavefields are prescribed by mode coupling theory and account for the coupling among surface waves, body waves, and evanescent waves. The described algorithm is, in principle, applicable to global and regional wave propagation problems, but I focus on higher frequency (typically f ??????0.25 Hz) applications at regional and local distances where the locked mode approximation is best utilized and which involve wavefields strongly shaped by propagation through a highly heterogeneous crust. Synthetic examples are shown for P-SV-wave propagation through a semi-ellipsoidal basin and SH-wave propagation through a fault zone.

  20. Sources of inter-firm heterogeneity in accessing knowledge-creation benefits within technology clusters

    NARCIS (Netherlands)

    Arikan, A.; Knoben, J.

    2014-01-01

    We build on recent literature to highlight the distinction between knowledge-diffusion and knowledge-creation benefits of technology clustering and argue that firms located in technology clusters will have differential access to the latter. To explain the antecedents of such differential access, we

  1. Dynamics of coupled contaminant and microbial transport in heterogeneous porous media. 1997 annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Ginn, T.R.; Boone, D.R.; Fletcher, M.M.; Friedrich, D.M.; Murphy, E.M.

    1997-06-01

    'Dynamic microbial attachment/detachment occurs in subsurface systems in response to changing environmental conditions caused by contaminant movement and degradation. Understanding the environmental conditions and mechanisms by which anaerobic bacteria partition between aqueous and solid phases is a critical requirement for designing and evaluating in situ bioremediation efforts. This interdisciplinary research project will provide fundamental information on the attachment/detachment dynamics of anaerobic bacteria in heterogeneous porous media under growth and growth-limiting conditions. Experiments will provide information on passive and active attachment/detachment mechanisms used by growing anaerobes capable of reductive dechlorination. Theoretical representations of these attachment/detachment mechanisms will be incorporated into existing groundwater flow and contaminant transport models that incorporate heterogeneity effects and can be used to predict behavior at field scales. These mechanistic-based models will be tested against experimental data provided through controlled laboratory experiments in heterogeneous porous media in large (meter-scale) 2-D flow cells. In addition to a mechanistic-based predictive model, this research will lead to new theories for the transient spatial distribution of microbial populations and contaminant plumes in heterogeneous porous media, improving the capability for designing staged remediation strategies for dealing with mixed contaminants.'

  2. Extracting heterogeneous compliance of a single fracture from seismic scattering coupled with perturbation theory

    NARCIS (Netherlands)

    Minato, S.; Ghose, R.

    2013-01-01

    We have presented a new methodology to model the scattered wavefield due to a heterogeneous distribution of compliance along a single fracture and then to invert this compliance distribution or its power spectral density (PSD) from the scattered seismic response. We illustrate the validity through n

  3. Heterogeneity and weak coupling may explain the synchronization characteristics of cells in the arterial wall

    DEFF Research Database (Denmark)

    Jacobsen, Jens Christian Brings; Aalkjær, Christian; Matchkov, Vladimir V

    2008-01-01

    be entrained at the onset of vasomotion by the collective driving force from the synchronized oscillations in the membrane potential of the surrounding cells. Partial synchronization arises with an increase in the concentration of cyclic guanosine monophosphate, but in a heterogeneous cell population complete...

  4. Epidemic modeling in metapopulation systems with heterogeneous coupling pattern: theory and simulations

    CERN Document Server

    Colizza, Vittoria

    2007-01-01

    The spatial structure of populations is a key element in the understanding of the large scale spreading of epidemics. Motivated by the recent empirical evidence on the heterogeneous properties of transportation and commuting patterns among urban areas, we present a thorough analysis of the behavior of infectious diseases in metapopulation models characterized by heterogeneous connectivity and mobility patterns. We derive the basic reaction-diffusion equation describing the metapopulation system at the mechanistic level and derive an early stage dynamics approximation for the subpopulation invasion dynamics. The analytical description uses degree block variables that allows us to take into account arbitrary degree distribution of the metapopulation network. We show that along with the usual single population epidemic threshold the metapopulation network exhibits a global threshold for the subpopulation invasion. We find an explicit analytic expression for the invasion threshold that determines the minimum numb...

  5. The EDEN-IW ontology model for sharing knowledge and water quality data between heterogenous databases

    DEFF Research Database (Denmark)

    Stjernholm, M.; Poslad, S.; Zuo, L.

    2004-01-01

    The Environmental Data Exchange Network for Inland Water (EDEN-IW) project's main aim is to develop a system for making disparate and heterogeneous databases of Inland Water quality more accessible to users. The core technology is based upon a combination of: ontological model to represent...... successfully demonstrated the use of our systems to semantically integrate two main database resources from IOW and NERI - these are available on-line. We are in the process of adding further databases and sup-porting a wider variety of user queries such as Decision Support System queries....

  6. Dynamics of Coupled Contaminant and Microbial Transport in Heterogeneous Porous Media: Purdue Component

    Energy Technology Data Exchange (ETDEWEB)

    Cushman, J.H.; Madilyn Fletcher

    2000-06-01

    Dynamic microbial attachment/detachment occurs in subsurface systems in response to changing environmental conditions caused by contaminant movement and degradation. Understanding the environmental conditions and mechanisms by which anaerobic bacteria partition between aqueous and solid phases is a critical requirement for designing and evaluating in situ bioremediation efforts. This interdisciplinary research project, of which we report only the Purdue contribution, provides fundamental information on the attachment/detachment dynamics of bacteria in heterogeneous porous media. Fundamental results from the Purdue collaboration are: (a) development of a matched-index method for obtaining 3-D Lagrangian trajectories of microbial sized particles transporting within porous media or microflow cells, (b) application of advanced numerical methods to optimally design a microflow cell for studying anaerobic bacterial attachment/detachment phenomena, (c) development of two types of models for simulating bacterial movement and attachment/detachment in microflow cells and natural porous media, (d) application of stochastic analysis to upscale pore scale microbial attachment/detachment models to natural heterogeneous porous media, and (e) evaluation of the role nonlocality plays in microbial dynamics in heterogeneous porous media

  7. Dynamics of Coupled Contaminant and Microbial Transport in Heterogeneous Porous Media: Purdue Component

    Energy Technology Data Exchange (ETDEWEB)

    Cushman, J.H.

    2000-06-01

    Dynamic microbial attachment/detachment occurs in subsurface systems in response to changing environmental conditions caused by contaminant movement and degradation. Understanding the environmental conditions and mechanisms by which anaerobic bacteria partition between aqueous and solid phases is a critical requirement for designing and evaluating in situ bioremediation efforts. This interdisciplinary research project, of which we report only the Purdue contribution, provides fundamental information on the attachment/detachment dynamics of bacteria in heterogeneous porous media. Fundamental results from the Purdue collaboration are: (a) development of a matched-index method for obtaining 3-D Lagrangian trajectories of microbial sized particles transporting within porous media or microflow cells, (b) application of advanced numerical methods to optimally design a microflow cell for studying anaerobic bacterial attachment/detachment phenomena, (c) development of two types of models for simulating bacterial movement and attachment/detachment in microflow cells and natural porous media, (d) application of stochastic analysis to upscale pore scale microbial attachment/detachment models to natural heterogeneous porous media, and (e) evaluation of the role nonlocality plays in microbial dynamics in heterogeneous porous media.

  8. Tracer travel and residence time distributions in highly heterogeneous aquifers: Coupled effect of flow variability and mass transfer

    Science.gov (United States)

    Cvetkovic, V.; Fiori, A.; Dagan, G.

    2016-12-01

    The driving mechanism of tracer transport in aquifers is groundwater flow which is controlled by the heterogeneity of hydraulic properties. We show how hydrodynamics and mass transfer are coupled in a general analytical manner to derive a physically-based (or process-based) residence time distribution for a given integral scale of the hydraulic conductivity; the result can be applied for a broad class of linear mass transfer processes. The derived tracer residence time distribution is a transfer function with parameters to be inferred from combined field and laboratory measurements. It is scalable relative to the correlation length and applicable for an arbitrary statistical distribution of the hydraulic conductivity. Based on the derived residence time distribution, the coefficient of variation and skewness of residence time are illustrated assuming a log-normal hydraulic conductivity field and first-order mass transfer. We show that for a low Damkohler number the coefficient of variation is more strongly influenced by mass transfer than by heterogeneity, whereas skewness is more strongly influenced by heterogeneity.

  9. Modeling multicomponent ionic transport in groundwater with IPhreeqc coupling: Electrostatic interactions and geochemical reactions in homogeneous and heterogeneous domains

    Science.gov (United States)

    Muniruzzaman, Muhammad; Rolle, Massimo

    2016-12-01

    The key role of small-scale processes like molecular diffusion and electrochemical migration has been increasingly recognized in multicomponent reactive transport in saturated porous media. In this study, we propose a two-dimensional multicomponent reactive transport model taking into account the electrostatic interactions during transport of charged ions in physically and chemically heterogeneous porous media. The modeling approach is based on the local charge balance and on the description of compound-specific and spatially variable diffusive/dispersive fluxes. The multicomponent ionic transport code is coupled with the geochemical code PHREEQC-3 by utilizing the IPhreeqc module, thus enabling to perform the geochemical calculations included in the PHREEQC's reaction package. The multicomponent reactive transport code is benchmarked with different 1-D and 2-D transport problems. Successively, conservative and reactive transport examples are presented to demonstrate the capability of the proposed model to simulate transport of charged species in heterogeneous porous media with spatially variable physical and chemical properties. The results reveal that the Coulombic cross-coupling between dispersive fluxes can significantly influence conservative as well as reactive transport of charged species both at the laboratory and at the field scale.

  10. Contraception knowledge status of marriage applicants couples in the Van city

    Directory of Open Access Journals (Sweden)

    Ahmet Yılmaz

    2013-09-01

    Full Text Available This study was performed to determine ofcontraception knowledge levels and planning contraceptionmethods after marriage that couples have applied tofamily planning center in the Van city.Methods: Study has planned as descriptive manner. Thisstudy was performed on 255 couples who have appliedfor official wedding procedure to Van maternal and childhealth and family planning center between September2010 - January 2011. Participants were determined on avoluntary basis. Questionnaires were filled out by familymedicine face to face with couples.Results: Totally, 21.3% percent of women, 23.5% percentof men have primary school degree. 18% of women,93.4% of men have a profession. 12.1% percent of womenand 12.9% percent of men does not have any knowledgeabout contraceptive and 43% of couples do not consideruse any contraceptive method after marriage. The resultshas shown that when evaluate the couples, in terms ofthe distribution of contraception information, the coupleshave more information about condoms, pills, coil, injectionand withdraw methods then tube ligation, implants,spermicides, vasectomy and the calendar methodsConclusion: Van region has a low socio-economic status.The couples should be informed about family planningbefore marriage, to talk about advantages of collaborationbetween the couples about birth control methodchoice.Key words: Reproductive health, family planning, contraception

  11. Knowledge, use, and concerns about contraceptive methods among sero-discordant couples in Rwanda and Zambia.

    Science.gov (United States)

    Grabbe, Kristina; Stephenson, Rob; Vwalika, Bellington; Ahmed, Yusuf; Vwalika, Cheswa; Chomba, Elwyn; Karita, Etienne; Kayitenkore, Kayitesi; Tichacek, Amanda; Allen, Susan

    2009-09-01

    The unique needs of sero-discordant couples are largely missing from many current family planning efforts, which focus on the prevention of pregnancies in absence of the reduction of the risk of human immunodeficiency virus (HIV) and other sexually transmitted infections (STIs). Conversely, HIV testing and programs focus exclusively on condom use without discussion of more effective contraceptive methods. In order to provide information to inform the development of family planning services tailored to the unique needs of sero-discordant couples, this study examined the contraceptive knowledge, use, and concerns among sero-discordant couples in urban Rwanda and Zambia. This article presents a comparison of family planning knowledge, use, and concerns about contraception among two cohorts of HIV sero-discordant study participants in Rwanda and Zambia. The results reveal an interesting profile of contraceptive knowledge and use among sero-discordant couples; in both settings, despite high levels of knowledge of contraception, use of contraceptive methods remains relatively low. There is a clear gender difference in both the reporting of knowledge and use of contraceptive methods, and there is evidence of clandestine contraceptive use by women. Including information on family planning in voluntary counseling and testing (VCT) services in addition to tailoring the delivery of family planning information to meet to needs and concerns of HIV-positive women or those with HIV positive partners is an essential step in the delivery of services and prevention efforts to reduce the transmission of HIV. Family planning and HIV prevention programs should integrate counseling on "dual method use," combining condoms for HIV/STI prevention with a long-acting contraceptive for added protection against unplanned pregnancy.

  12. KNOWLEDGE AND PRACTICE OF CONTRACEPTIVE USE AMONG THE ELIGIBLE COUPLES IN AN URBAN SLUM OF SAMBALPUR

    Directory of Open Access Journals (Sweden)

    Mamatarani

    2015-09-01

    Full Text Available BACKGROUND: In spite of implementation of various programs and policies to curb the population of India, the population growth of India continues to be high in the count of large size of population (58% of total population in the reproductive age group and high fertilit y rate due to unmet need for contraception. OBJECTIVES: To know the knowledge and practice of various contraceptives among the eligible couples. MATERIALS AND METHOD S: A cross sectional study was conducted in the field practice area of UHTC, Gaudapali whic h is an urban slum, Sambalpur. The data was collected by interview of the female partners of the eligible couple by house to house visit using a predesigned questionnaire. RESULTS: Total of 212 marries women of the reproductive age group participated in th e study, most of the couples (96% had knowledge about some contraceptive. Majority of them (69% considered those methods to be quite safe & effective and easy to use. Major source of information (39% was from health care workers. Only 62% of the couples had practiced the contraceptive method. CONCLUSION: The increased use of contraceptive requires IEC activity and continuous motivation among the male partner of the couple

  13. The formation of share market prices under heterogeneous beliefs and common knowledge

    CERN Document Server

    Biondi, Yuri; Galam, Serge

    2011-01-01

    Financial economic models often assume that investors know (or agree on) the fundamental value of the shares of the firm, easing the passage from the individual to the collective dimension of the financial system generated by the Share Exchange over time. Our model relaxes that heroic assumption of one unique "true value" and deals with the formation of share market prices through the dynamic formation of individual and social opinions (or beliefs) based upon a fundamental signal of economic performance and position of the firm, the forecast revision by heterogeneous individual investors, and their social mood or sentiment about the ongoing state of the market pricing process. Market clearing price formation is then featured by individual and group dynamics that make its collective dimension irreducible to its individual level. This dynamic holistic approach can be applied to better understand the market exuberance generated by the Share Exchange over time.

  14. Formation of share market prices under heterogeneous beliefs and common knowledge

    Science.gov (United States)

    Biondi, Yuri; Giannoccolo, Pierpaolo; Galam, Serge

    2012-11-01

    Financial economic models often assume that investors know (or agree on) the fundamental value of the shares of the firm, easing the passage from the individual to the collective dimension of the financial system generated by the Share Exchange over time. Our model relaxes that heroic assumption of one unique “true value” and deals with the formation of share market prices through the dynamic formation of individual and social opinions (or beliefs) based upon a fundamental signal of economic performance and position of the firm, the forecast revision by heterogeneous individual investors, and their social mood or sentiment about the ongoing state of the market pricing process. Market clearing price formation is then featured by individual and group dynamics that make its collective dimension irreducible to its individual level. This dynamic holistic approach can be applied to better understand the market exuberance generated by the Share Exchange over time.

  15. Drug Distribution: A Guided-Inquiry Laboratory Experiment in Coupled Homogeneous and Heterogeneous Equilibria

    Science.gov (United States)

    Hein, John; Jeannot, Michael

    2001-02-01

    A simple and inexpensive experiment for the study of simultaneous homogeneous and heterogeneous equilibria is described using a common antihistamine drug, diphenhydramine. This experiment gives students an opportunity to study the distribution of a drug in a two-phase system by measuring the concentrations of two chemical species and predicting the others by considering charge balance, mass balance, and equilibrium constant expressions. Furthermore, the acid-dissociation constant and aqueous-organic distribution coefficient can be calculated. The experiment is attractive to students because it represents a simplified model for something experienced in everyday life, namely, drug distribution in the human body. Students also gain experience with two very important analytical techniques, gas chromatography and pH measurement with a glass electrode.

  16. A global method for coupling transport with chemistry in heterogeneous porous media

    CERN Document Server

    Laila, Amir; 10.1007/s10596-009-9162-x

    2009-01-01

    Modeling reactive transport in porous media, using a local chemical equilibrium assumption, leads to a system of advection-diffusion PDE's coupled with algebraic equations. When solving this coupled system, the algebraic equations have to be solved at each grid point for each chemical species and at each time step. This leads to a coupled non-linear system. In this paper a global solution approach that enables to keep the software codes for transport and chemistry distinct is proposed. The method applies the Newton-Krylov framework to the formulation for reactive transport used in operator splitting. The method is formulated in terms of total mobile and total fixed concentrations and uses the chemical solver as a black box, as it only requires that on be able to solve chemical equilibrium problems (and compute derivatives), without having to know the solution method. An additional advantage of the Newton-Krylov method is that the Jacobian is only needed as an operator in a Jacobian matrix times vector product...

  17. Fuzzy-Based Knowledge Discovery from Heterogeneous Data in Planting Systems for Elderly LOHAS

    Institute of Scientific and Technical Information of China (English)

    Hung-Chih Hsueh; Jung-Yi Jiang; Jen-Sheng Tsai; Wen-Hao Tsai; Kuan-Rong Lee; Yau-Hwang Kuo

    2015-01-01

    Abstract⎯In this paper, we propose a knowledge discovery method based on the fuzzy set theory to help elders with plant cultivation. Initially, the fuzzy sets are constructed by using the feature selection and statistical interval estimation. The min-max inference and the center of gravity defuzzification method are then used to output a candidate pattern set. Finally, a pattern discovery is adopted to obtain the patterns from the candidate set for the cultivation suggestions by considering the frequency weight and user’s experience. In order to demonstrate the performance of our method in planting systems, we conduct a clicks-and-mortar cultivation platform, namely Eden Garden, for the elderly lifestyles of health and sustainability (LOHAS). The experimental results show that the accuracy rate of our knowledge discovery method can reach up to 85%. Moreover, the results of the LOHAS index scale table present that the happiness of the elders is increasing while the elders are using our proposed method.

  18. Ferromagnetic resonance of an heterogeneous multilayer system with interlayer exchange coupling: an accessible model

    Science.gov (United States)

    Franco, A. F.; Landeros, P.

    2016-09-01

    We present a general model for the coupled magnetic resonances of an exchange interacting multilayer system, which can be implemented without complex analytical calculations or numerical simulations. The model allows one to study the spin wave modes of a multilayer structure with any number of layers, accounting for individual uniaxial and cubic anisotropies, and (static and dynamic) demagnetizing and external fields as well, assuming that only the interlayer exchange coupling mechanism is relevant between such magnetic layers. This scheme is applied to recent measurements of a NiFe/CoFe bilayer, and to studying the influence of the strength of ferromagnetic and antiferromagnetic exchange interactions and the applied field orientation on the spin wave modes and intensities of the ferromagnetic resonance response. We find that the acoustic oscillation mode tends to stabilize in frequency if the magnetizations of the layers are parallel to each other, while the optical mode stabilizes when the magnetizations are antiparallel. Furthermore, we find that each oscillation mode is governed by either the NiFe or the CoFe. The modes swap the governing layer as the perpendicular field increases, inducing a gap between their frequencies, which appears to be proportional to the exchange coupling. Finally, we find that the field linewidth of the bilayer due to Gilbert damping has a dependence on the frequency very similar to the linear dependence of the linewidth in single layers. The theoretical scheme presented here can be further used to explore magnetization dynamics in different multilayer architectures—such as exchange springs, structures with perpendicular magnetic anisotropy, and complex compositions of layer stacks—and can be useful as a basis to study multilayers with chiral and dipolar interactions.

  19. Emergence of localized patterns in globally coupled networks of relaxation oscillators with heterogeneous connectivity

    Science.gov (United States)

    Leiser, Randolph J.; Rotstein, Horacio G.

    2017-08-01

    Oscillations in far-from-equilibrium systems (e.g., chemical, biochemical, biological) are generated by the nonlinear interplay of positive and negative feedback effects operating at different time scales. Relaxation oscillations emerge when the time scales between the activators and the inhibitors are well separated. In addition to the large-amplitude oscillations (LAOs) or relaxation type, these systems exhibit small-amplitude oscillations (SAOs) as well as abrupt transitions between them (canard phenomenon). Localized cluster patterns in networks of relaxation oscillators consist of one cluster oscillating in the LAO regime or exhibiting mixed-mode oscillations (LAOs interspersed with SAOs), while the other oscillates in the SAO regime. Because the individual oscillators are monostable, localized patterns are a network phenomenon that involves the interplay of the connectivity and the intrinsic dynamic properties of the individual nodes. Motivated by experimental and theoretical results on the Belousov-Zhabotinsky reaction, we investigate the mechanisms underlying the generation of localized patterns in globally coupled networks of piecewise-linear relaxation oscillators where the global feedback term affects the rate of change of the activator (fast variable) and depends on the weighted sum of the inhibitor (slow variable) at any given time. We also investigate whether these patterns are affected by the presence of a diffusive type of coupling whose synchronizing effects compete with the symmetry-breaking global feedback effects.

  20. Noniterative Multireference Coupled Cluster Methods on Heterogeneous CPU-GPU Systems.

    Science.gov (United States)

    Bhaskaran-Nair, Kiran; Ma, Wenjing; Krishnamoorthy, Sriram; Villa, Oreste; van Dam, Hubertus J J; Aprà, Edoardo; Kowalski, Karol

    2013-04-09

    A novel parallel algorithm for noniterative multireference coupled cluster (MRCC) theories, which merges recently introduced reference-level parallelism (RLP) [Bhaskaran-Nair, K.; Brabec, J.; Aprà, E.; van Dam, H. J. J.; Pittner, J.; Kowalski, K. J. Chem. Phys.2012, 137, 094112] with the possibility of accelerating numerical calculations using graphics processing units (GPUs) is presented. We discuss the performance of this approach applied to the MRCCSD(T) method (iterative singles and doubles and perturbative triples), where the corrections due to triples are added to the diagonal elements of the MRCCSD effective Hamiltonian matrix. The performance of the combined RLP/GPU algorithm is illustrated on the example of the Brillouin-Wigner (BW) and Mukherjee (Mk) state-specific MRCCSD(T) formulations.

  1. Lakeshore zoning has heterogeneous ecological effects: an application of a coupled economic-ecological model.

    Science.gov (United States)

    Butsic, Van; Lewis, David J; Radeloff, Volker C

    2010-04-01

    Housing growth has been widely shown to be negatively correlated with wildlife populations, avian richness, anadromous fish, and exotic invasion. Zoning is the most frequently used public policy to manage housing development and is often motivated by a desire to protect the environment. Zoning is also pervasive, taking place in all 50 states. One relevant question that has received little research concerns the effectiveness of zoning to meet ecological goals. In this paper, we examined whether minimum frontage zoning policies have made a positive impact on the lakes they were aimed to protect in Vilas County, Wisconsin, U.S.A. We used an economic model that estimated when a given lot will be subdivided and how many new lots will be created as a function of zoning. Using the economic model, we simulated the effects of multiple zoning scenarios on lakeshore development. The simulated development patterns were then input to ecological models that predicted the amount of coarse woody debris (CWD) and the growth rate of bluegills as a function of residential density. Comparison of the ecological outcomes under different simulated zoning scenarios quantified the effect of zoning policies on residential density, CWD, and bluegill growth rates. Our results showed that zoning significantly affected residential density, CWD counts, and bluegill growth rates across our study area, although the effect was less clear at the scale of individual lake. Our results suggest that homogeneous zoning (i.e., for a county) is likely to have mixed results when applied to a heterogeneous landscape. Further, our results suggest that zoning regimes with a higher minimum shoreline frontage are likely to have larger ecological effects when applied to lakes that are less developed.

  2. Salicylic acid degradation by advanced oxidation processes. Coupling of solar photoelectro-Fenton and solar heterogeneous photocatalysis.

    Science.gov (United States)

    Garza-Campos, Benjamin; Brillas, Enric; Hernández-Ramírez, Aracely; El-Ghenymy, Abdellatif; Guzmán-Mar, Jorge Luis; Ruiz-Ruiz, Edgar J

    2016-12-05

    A 3.0 L solar flow plant with a Pt/air-diffusion (anode/cathode) cell, a solar photoreactor and a photocatalytic photoreactor filled with TiO2-coated glass spheres has been utilized to couple solar photoelectro-Fenton (SPEF) and solar heterogeneous photocatalysis (SPC) for treating a 165mgL(-1) salicylic acid solution of pH 3.0. Organics were destroyed by OH radicals formed on the TiO2 photocatalyst and at the Pt anode during water oxidation and in the bulk from Fenton's reaction between added Fe(2+) and cathodically generated H2O2, along with the photolytic action of sunlight. Poor salicylic acid removal and mineralization were attained using SPC, anodic oxidation with electrogenerated H2O2 (AO-H2O2) and coupled AO-H2O2-SPC. The electro-Fenton process accelerated the substrate decay, but with low mineralization by the formation of byproducts that are hardly destroyed by OH. The mineralization was strongly increased by SPEF due to the photolysis of products by sunlight, being enhanced by coupled SPEF-SPC due to the additional oxidation by OH at the TiO2 surface. The effect of current density on the performance of both processes was examined. The most potent SPEF-SPC process at 150mAcm(-2) yielded 87% mineralization and 13% current efficiency after consuming 6.0AhL(-1). Maleic, fumaric and oxalic acids detected as final carboxylic acids were completely removed by SPEF and SPEF-SPC.

  3. Knowledge evolution in physics research: An analysis of bibliographic coupling networks.

    Science.gov (United States)

    Liu, Wenyuan; Nanetti, Andrea; Cheong, Siew Ann

    2017-01-01

    Even as we advance the frontiers of physics knowledge, our understanding of how this knowledge evolves remains at the descriptive levels of Popper and Kuhn. Using the American Physical Society (APS) publications data sets, we ask in this paper how new knowledge is built upon old knowledge. We do so by constructing year-to-year bibliographic coupling networks, and identify in them validated communities that represent different research fields. We then visualize their evolutionary relationships in the form of alluvial diagrams, and show how they remain intact through APS journal splits. Quantitatively, we see that most fields undergo weak Popperian mixing, and it is rare for a field to remain isolated/undergo strong mixing. The sizes of fields obey a simple linear growth with recombination. We can also reliably predict the merging between two fields, but not for the considerably more complex splitting. Finally, we report a case study of two fields that underwent repeated merging and splitting around 1995, and how these Kuhnian events are correlated with breakthroughs on Bose-Einstein condensation (BEC), quantum teleportation, and slow light. This impact showed up quantitatively in the citations of the BEC field as a larger proportion of references from during and shortly after these events.

  4. Translation-coupled violation of Parity Rule 2 in human genes is not the cause of heterogeneity of the DNA G+C content of third codon position.

    Science.gov (United States)

    Sueoka, N

    1999-09-30

    The genome of higher eukaryotes consists of genes having a widely heterogeneous base composition at the third codon position. Ubiquitous variability of the DNA base composition has the following two aspects: intragenomic heterogeneity of the G+C content and the amino-acid-specific translation-coupled biases from the Parity Rule 2 (PR2). PR2 is an intrastrand rule where A = T and G = C are expected if there is no bias in mutation and selection between the two complementary strands of DNA. To examine whether or not the biases from PR2 are responsible for the wide heterogeneity of the DNA G+C content in human, the third codon position of 846 human genes was analyzed. Genes were separated into six groups according to their G+C content of the third codon position, and each group was examined for the translation-coupled PR2 biases in the nucleotide composition of the third codon position for two- and four-codon amino acids. The results show that genes in the different G+C content groups have similar PR2 biases, indicating that the intragenomic heterogeneity of the G+C content is not correlated with translation-coupled biases from the PR2. Therefore, the heterogeneity of the G+C content is likely to be determined by some other mechanism (e.g. locally variable directional mutation pressures) than amino-acid-specific selections for the codon preference.

  5. A coupled remote sensing and the Surface Energy Balance with Topography Algorithm (SEBTA to estimate actual evapotranspiration over heterogeneous terrain

    Directory of Open Access Journals (Sweden)

    Z. Q. Gao

    2011-01-01

    Full Text Available Evapotranspiration (ET may be used as an ecological indicator to address the ecosystem complexity. The accurate measurement of ET is of great significance for studying environmental sustainability, global climate changes, and biodiversity. Remote sensing technologies are capable of monitoring both energy and water fluxes on the surface of the Earth. With this advancement, existing models, such as SEBAL, S_SEBI and SEBS, enable us to estimate the regional ET with limited temporal and spatial coverage in the study areas. This paper extends the existing modeling efforts with the inclusion of new components for ET estimation at different temporal and spatial scales under heterogeneous terrain with varying elevations, slopes and aspects. Following a coupled remote sensing and surface energy balance approach, this study emphasizes the structure and function of the Surface Energy Balance with Topography Algorithm (SEBTA. With the aid of the elevation and landscape information, such as slope and aspect parameters derived from the digital elevation model (DEM, and the vegetation cover derived from satellite images, the SEBTA can account for the dynamic impacts of heterogeneous terrain and changing land cover with some varying kinetic parameters (i.e., roughness and zero-plane displacement. Besides, the dry and wet pixels can be recognized automatically and dynamically in image processing thereby making the SEBTA more sensitive to derive the sensible heat flux for ET estimation. To prove the application potential, the SEBTA was carried out to present the robust estimates of 24 h solar radiation over time, which leads to the smooth simulation of the ET over seasons in northern China where the regional climate and vegetation cover in different seasons compound the ET calculations. The SEBTA was validated by the measured data at the ground level. During validation, it shows that the consistency index reached 0.92 and the correlation coefficient was 0.87.

  6. A coupled remote sensing and the Surface Energy Balance with Topography Algorithm (SEBTA) to estimate actual evapotranspiration over heterogeneous terrain

    Science.gov (United States)

    Gao, Z. Q.; Liu, C. S.; Gao, W.; Chang, N.-B.

    2011-01-01

    Evapotranspiration (ET) may be used as an ecological indicator to address the ecosystem complexity. The accurate measurement of ET is of great significance for studying environmental sustainability, global climate changes, and biodiversity. Remote sensing technologies are capable of monitoring both energy and water fluxes on the surface of the Earth. With this advancement, existing models, such as SEBAL, S_SEBI and SEBS, enable us to estimate the regional ET with limited temporal and spatial coverage in the study areas. This paper extends the existing modeling efforts with the inclusion of new components for ET estimation at different temporal and spatial scales under heterogeneous terrain with varying elevations, slopes and aspects. Following a coupled remote sensing and surface energy balance approach, this study emphasizes the structure and function of the Surface Energy Balance with Topography Algorithm (SEBTA). With the aid of the elevation and landscape information, such as slope and aspect parameters derived from the digital elevation model (DEM), and the vegetation cover derived from satellite images, the SEBTA can account for the dynamic impacts of heterogeneous terrain and changing land cover with some varying kinetic parameters (i.e., roughness and zero-plane displacement). Besides, the dry and wet pixels can be recognized automatically and dynamically in image processing thereby making the SEBTA more sensitive to derive the sensible heat flux for ET estimation. To prove the application potential, the SEBTA was carried out to present the robust estimates of 24 h solar radiation over time, which leads to the smooth simulation of the ET over seasons in northern China where the regional climate and vegetation cover in different seasons compound the ET calculations. The SEBTA was validated by the measured data at the ground level. During validation, it shows that the consistency index reached 0.92 and the correlation coefficient was 0.87.

  7. Stochastic analysis of the efficiency of coupled hydraulic-physical barriers to contain solute plumes in highly heterogeneous aquifers

    Science.gov (United States)

    Pedretti, Daniele; Masetti, Marco; Beretta, Giovanni Pietro

    2017-10-01

    The expected long-term efficiency of vertical cutoff walls coupled to pump-and-treat technologies to contain solute plumes in highly heterogeneous aquifers was analyzed. A well-characterized case study in Italy, with a hydrogeological database of 471 results from hydraulic tests performed on the aquifer and the surrounding 2-km-long cement-bentonite (CB) walls, was used to build a conceptual model and assess a representative remediation site adopting coupled technologies. In the studied area, the aquifer hydraulic conductivity Ka [m/d] is log-normally distributed with mean E (Ya) = 0.32 , variance σYa2 = 6.36 (Ya = lnKa) and spatial correlation well described by an exponential isotropic variogram with integral scale less than 1/12 the domain size. The hardened CB wall's hydraulic conductivity, Kw [m/d], displayed strong scaling effects and a lognormal distribution with mean E (Yw) = - 3.43 and σYw2 = 0.53 (Yw =log10Kw). No spatial correlation of Kw was detected. Using this information, conservative transport was simulated across a CB wall in spatially correlated 1-D random Ya fields within a numerical Monte Carlo framework. Multiple scenarios representing different Kw values were tested. A continuous solute source with known concentration and deterministic drains' discharge rates were assumed. The efficiency of the confining system was measured by the probability of exceedance of concentration over a threshold (C∗) at a control section 10 years after the initial solute release. It was found that the stronger the aquifer heterogeneity, the higher the expected efficiency of the confinement system and the lower the likelihood of aquifer pollution. This behavior can be explained because, for the analyzed aquifer conditions, a lower Ka generates more pronounced drawdown in the water table in the proximity of the drain and consequently a higher advective flux towards the confined area, which counteracts diffusive fluxes across the walls. Thus, a higher σYa2 results

  8. Communication, knowledge, social network and family planning utilization among couples in Mwanza, Tanzania.

    Science.gov (United States)

    Mosha, Idda H; Ruben, Ruerd

    2013-09-01

    Family planning utilization in Tanzania is low. This study was cross sectional. It examined family planning use and socio demographic variables, social networks, knowledge and communication among the couples, whereby a stratified sample of 440 women of reproductive age (18-49), married or cohabiting was studied in Mwanza, Tanzania. A structured questionnaire with questions on knowledge, communication among the couples and practice of family planning was used. Descriptive statistics and Logistic regression were used to identify factors associated with family planning (FP) use at four levels. The findings showed that majority (73.2%) of respondents have not used family planning. Wealth was positive related to FP use (p=.000, OR = 3.696, and 95% C.I = 1.936 lower and upper 7.055). Religion was associated with FP use (p=.002, OR =2.802, 95% C.I = 1.476 lower and 5.321 upper), communication and FP use were significantly associated, (p=.000, OR = 0.323 and 95% C.I = 0.215) lower and upper = 0.483), social network and FP use (p=.000, OR = 2.162 and 95% C.I = 1.495 lower and upper =3.125) and knowledge and FP use(p=.000, OR = 2.224 and 95% C.I = 1.509 lower and upper =3.278). Wealth showed a significant association with FP use (p=.001, OR = 1.897, 95% C.I = 0.817 lower and 4.404).Urban area was positively associated with FP use (p= .000, OR = 0.008 and 95% C.I = 0.001 lower and upper =0.09), semi urban was significant at (p= .004, OR = 3.733 and C.I = 1.513 lower and upper =9.211). Information, education and communication materials and to promote family planning in Tanzania should designed and promoted.

  9. Intraclade heterogeneity in nitrogen utilization by marine prokaryotes revealed using stable isotope probing coupled with tag sequencing (Tag-SIP

    Directory of Open Access Journals (Sweden)

    Michael Morando

    2016-12-01

    Full Text Available Nitrogen can greatly influence the structure and productivity of microbial communities through its relative availability and form. However, roles of specific organisms in the uptake of different nitrogen species remain poorly characterized. Most studies seeking to identify agents of assimilation have been correlative, indirectly linking activity measurements (e.g., nitrate uptake with the presence or absence of biological markers, particularly functional genes and their transcripts. Evidence is accumulating of previously underappreciated functional diversity in major microbial subpopulations, which may confer physiological advantages under certain environmental conditions leading to ecotype divergence. This microdiversity further complicates our view of genetic variation in environmental samples requiring the development of more targeted approaches. Here, next-generation tag sequencing was successfully coupled with stable isotope probing (Tag-SIP to assess the ability of individual phylotypes to assimilate a particular N source. Our results provide the first direct evidence of nitrate utilization by organisms thought to lack the genes required for this process including the heterotrophic clades SAR11 and the Archaeal Marine Group II (MG-II. We also provide new direct evidence of in situ nitrate utilization by the cyanobacterium Prochlorococcus in support of recent findings. Furthermore, these results revealed widespread functional heterogeneity, i.e. different levels of N assimilation within clades, likely reflecting niche partitioning by ecotypes. The addition of nitrate utilization to ecosystem and ecosystem models by these globally dominant clades will likely improve the mechanistic accuracy of these models.

  10. Family planning knowledge, attitude and practice among married couples in Jimma Zone, Ethiopia.

    Directory of Open Access Journals (Sweden)

    Tizta Tilahun

    Full Text Available BACKGROUND: Understanding why people do not use family planning is critical to address unmet needs and to increase contraceptive use. According to the Ethiopian Demographic and Health Survey 2011, most women and men had knowledge on some family planning methods but only about 29% of married women were using contraceptives. 20% women had an unmet need for family planning. We examined knowledge, attitudes and contraceptive practice as well as factors related to contraceptive use in Jimma zone, Ethiopia. METHODS: Data were collected from March to May 2010 among 854 married couples using a multi-stage sampling design. Quantitative data based on semi-structured questionnaires was triangulated with qualitative data collected during focus group discussions. We compared proportions and performed logistic regression analysis. RESULT: The concept of family planning was well known in the studied population. Sex-stratified analysis showed pills and injectables were commonly known by both sexes, while long-term contraceptive methods were better known by women, and traditional methods as well as emergency contraception by men. Formal education was the most important factor associated with better knowledge about contraceptive methods (aOR = 2.07, p<0.001, in particular among women (aOR(women = 2.77 vs. aOR(men = 1.49; p<0.001. In general only 4 out of 811 men ever used contraception, while 64% and 43% females ever used and were currently using contraception respectively. CONCLUSION: The high knowledge on contraceptives did not match with the high contraceptive practice in the study area. The study demonstrates that mere physical access (proximity to clinics for family planning and awareness of contraceptives are not sufficient to ensure that contraceptive needs are met. Thus, projects aiming at increasing contraceptive use should contemplate and establish better counseling about contraceptive side effects and method switch. Furthermore in all family planning

  11. Research on the Relationship between Knowledge Heterogeneity and the Knowledge Innovation Performance:Based on the R&D Team%知识异质性与知识创新绩效的关系研究

    Institute of Scientific and Technical Information of China (English)

    王颖; 彭灿

    2012-01-01

    Based on the analyses and discussions on the concept of knowledge heterogeneity and knowledge innovation performance , the article discusses the relationship hypothesis between knowledge heterogeneity and knowledge innovation performance,based on literature review. Then, certain hypotheses are brought forward and investigation questionnaires for the case verification are obtained by visiting 142 group members with group work experiences in R&-D teams. The study finds that the heterogeneity of education background has negative influence on the knowledge innovation performance, the knowledge skills and professional experience heterogeneity has positive influence on the knowledge innovation performance. In the last part,the results of the research are discussed,and relevant countermeasures are put forward.%在界定知识异质性和知识创新绩效概念的基础上,基于相关研究文献,提出了知识异质性与知识创新绩效的关系假设,以企业研发团队为例,通过对有研发团队工作经验的142名员工进行问卷调查,并对获得的有关数据进行了分析.研究结果显示:团队成员的教育背景异质性对知识创新绩效产生负面影响;知识技能与职业经验并质性对研发团队知识创新绩效均有积极显著影响,藉此进行了实证分析,进而提出了对策建议.

  12. On the estimate of the transpiration in Mediterranean heterogeneous ecosystems with the coupled use of eddy covariance and sap flow techniques.

    Science.gov (United States)

    Corona, Roberto; Curreli, Matteo; Montaldo, Nicola; Oren, Ram

    2013-04-01

    Mediterranean ecosystems are commonly heterogeneous savanna-like ecosystems, with contrasting plant functional types (PFT) competing for the water use. Mediterranean regions suffer water scarcity due to the dry climate conditions. In semi-arid regions evapotranspiration (ET) is the leading loss term of the root-zone water budget with a yearly magnitude that may be roughly equal to the precipitation. Despite the attention these ecosystems are receiving, a general lack of knowledge persists about the estimate of ET and the relationship between ET and the plant survival strategies for the different PFTs under water stress. During the dry summers these water-limited heterogeneous ecosystems are mainly characterized by a simple dual PFT-landscapes with strong-resistant woody vegetation and bare soil since grass died. In these conditions due to the low signal of the land surface fluxes captured by the sonic anemometer and gas analyzer the widely used eddy covariance may fail and its ET estimate is not robust enough. In these conditions the use of the sap flow technique may have a key role, because theoretically it provides a direct estimate of the woody vegetation transpiration. Through the coupled use of the sap flow sensor observations, a 2D foot print model of the eddy covariance tower and high resolution satellite images for the estimate of the foot print land cover map, the eddy covariance measurements can be correctly interpreted, and ET components (bare soil evaporation and woody vegetation transpiration) can be separated. The case study is at the Orroli site in Sardinia (Italy). The site landscape is a mixture of Mediterranean patchy vegetation types: trees, including wild olives and cork oaks, different shrubs and herbaceous species. An extensive field campaign started in 2004. Land-surface fluxes and CO2 fluxes are estimated by an eddy covariance technique based micrometeorological tower. Soil moisture profiles were also continuously estimated using water

  13. 异质知识网络相关度算法研究%Research on Relatedness Algorithms in Heterogeneous Knowledge Network

    Institute of Scientific and Technical Information of China (English)

    裘江南; 秦璇; 仲秋雁

    2011-01-01

    异质知识网络是Web2.0的基础,其中的相关度算法是实现通过信息检索人、资源或通过人检索信息、资源的关键.然而目前的相关度算法研究大多局限于同质知识网络,忽略了在异质知识网络中的研究.因此,本文结合异质知识网络所具有的特性,明确异质知识网络相关度的定义,进而对现有的相关度算法分析的基础上,总结并归纳适用于异质知识网络的相关度算法,并根据Web2.0环境下产生的社会性信息检索需求,进一步说明其未来的发展趋势.%Heterogeneous knowledge network is the foundation of Web 2.0. Relatedness algorithms in those networks are critical for retrieving people, resources through information or retrieving information through people, resources. But the current research is limited to homogeneous knowledge networks and ignores that in heterogeneous knowledge networks. For the above, this paper puts forward the definition of the relatedness of heterogeneous knowledge network, summarizes the relatedness algorithms for heterogeneous knowledge networks, and shows its future trends, based on the analysis of existing relatedness algorithms and social information search requirements caused by Web 2.0.

  14. Evaluation Study on Collaborative Effectiveness of Heterogeneity Knowledge Team%异质性知识团队协同效能评价研究

    Institute of Scientific and Technical Information of China (English)

    李丽艳; 杨文彩; 王瑞杰; 陈立畅

    2011-01-01

    For evaluation collaborative effectiveness of heterogeneity knowledge team, firstly this paper defines the concepts of heterogeneity knowledge team and team collaborative effectiveness, and the features of heterogeneity knowledge team collaborative effectiveness are researched deeply. Then, one grade evaluation index of team collaborative effectiveness is researched in Delphi method, and obtained 5 indexes:quantity and quality of results, collaborative satisfaction of team members, enhancement degree, future viability of team, rational use of funds. Lastly, an index of evaluation grade two of team collaborative effectiveness is designed.%针对异质性知识团队协同效能评价的问题,首先界定了异质性知识团队和团队协同效能的概念,并对异质性知识团队协同效能的特点进行了深入研究;然后,运用Dephi法对团队协同效能一级评价指标进行研究,得出5个一级指标:成果数量和质量、成员协作满意度、能力提升度、团队未来生存力、经费使用合理性;最后设计出团队协同效能的二级评价指标.

  15. Aggregate-scale spatial heterogeneity in reductive transformation of ferrihydrite resulting from coupled biogeochemical and physical processes

    Science.gov (United States)

    Pallud, C.; Masue-Slowey, Y.; Fendorf, S.

    2010-05-01

    Iron (hydr)oxides are ubiquitous in soils and sediments and play a dominant role in the geochemistry of surface and subsurface environments. Their fate depends on local environmental conditions, which in structured soils may vary significantly over short distances due to mass-transfer limitations on solute delivery and metabolite removal. In the present study, artificial soil aggregates were used to investigate the coupling of physical and biogeochemical processes affecting the spatial distribution of iron (Fe) phases resulting from reductive transformation of ferrihydrite. Spherical aggregates made of ferrihydrite-coated sand were inoculated with the dissimilatory Fe-reducing bacterium Shewanella putrefaciens strain CN-32, and placed into a flow reactor, the reaction cell simulates a diffusion-dominated soil aggregate surrounded by an advective flow domain. The spatial and temporal evolution of secondary mineralization products resulting from dissimilatory Fe reduction of ferrihydrite were followed within the aggregates in response to a range of flow rates and lactate concentrations. Strong radial variations in the distribution of secondary phases were observed owing to diffusively controlled delivery of lactate and efflux of Fe(II) and bicarbonate. In the aggregate cortex, only limited formation of secondary Fe phases were observed over 30 d of reaction, despite high rates of ferrihydrite reduction. Under all flow conditions tested, ferrihydrite transformation was limited in the cortex (70-85 mol.% Fe remained as ferrihydrite) because metabolites such as Fe(II) and bicarbonate were efficiently removed in outflow solutes. In contrast, within the inner fractions of the aggregate, limited mass-transfer results in metabolite (Fe(II) and bicarbonate) build-up and the consummate transformation of ferrihydrite - only 15-40 mol.% Fe remained as ferrihydrite after 30 d of reaction. Goethite/lepidocrocite, and minor amounts of magnetite, formed in the aggregate mid

  16. Knowledge and perceived risks in couples undergoing genetic testing after recurrent miscarriage or for poor semen quality

    NARCIS (Netherlands)

    Vansenne, F.; Goddijn, M.; Redeker, B.; Snijder, S.; Gerssen-Schoorl, K.; Lemmink, H.; Leschot, N. J.; van der Veen, F.; Bossuyt, P. M. M.; de Borgie, C. A. J. M.

    2011-01-01

    Couples with recurrent miscarriage (RM) and men with poor semen quality may undergo genetic testing as part of the diagnostic work-up. This study explored their knowledge and perception of genetic testing, evaluated psychological wellbeing and identified associated variables. A prospective questionn

  17. Community based study on married couples' family planning knowledge, attitude and practice in rural and urban Gambia.

    Science.gov (United States)

    Jammeh, Sulayman S S; Liu, Chieh-Yu; Cheng, Su-Fen; Lee-Hsieh, Jane

    2014-06-01

    Family planning services have been free of charge and available in all the health facilities in the Gambia since 1975 yet contraceptive prevalence is only 17.5% and even 6% in some areas. Since the last census in 2003, there existed no available data on married couples' contraception status. To explore married couples' family planning knowledge, attitudes, and practices in rural and urban Gambia and to analyze what factors may affect such knowledge, attitudes and practices. Quantitative cross-sectional study design was used. Through convenience sampling, 176 men and 235 women representing a total of 176 couples participated. A structured questionnaire was used for data collection. The mean scores of the married couples family planning knowledge, attitudes, and practices were 19.00 ± 6.11(ranging from 0 to 64), 6.90 ± 3.08 (0 to 14) and 4.69 ± 3.3 (0 to 19) respectively. Urban residents had higher scores on family planning practice than rural residents (pplanning knowledge, attitude and practice in Gambia", as well as suggesting broader health intervention programs in health education and promotion.

  18. Knowledge and perceptions of couples' voluntary counseling and testing in urban Rwanda and Zambia: a cross-sectional household survey.

    Directory of Open Access Journals (Sweden)

    April L Kelley

    Full Text Available BACKGROUND: Most incident HIV infections in sub-Saharan Africa occur between cohabiting, discordant, heterosexual couples. Though couples' voluntary HIV counseling and testing (CVCT is an effective, well-studied intervention in Africa, <1% of couples have been jointly tested. METHODS: We conducted cross-sectional household surveys in Kigali, Rwanda (n = 600 and Lusaka, Zambia (n = 603 to ascertain knowledge, perceptions, and barriers to use of CVCT. RESULTS: Compared to Lusaka, Kigali respondents were significantly more aware of HIV testing sites (79% vs. 56%; had greater knowledge of HIV serodiscordance between couples (83% vs. 43%; believed CVCT is good (96% vs. 72%; and were willing to test jointly (91% vs. 47%. Stigma, fear of partner reaction, and distance/cost/logistics were CVCT barriers. CONCLUSIONS: Though most respondents had positive attitudes toward CVCT, the majority were unaware that serodiscordance between cohabiting couples is possible. Future messages should target gaps in knowledge about serodiscordance, provide logistical information about CVCT services, and aim to reduce stigma and fear.

  19. Survey of HIV care providers on management of HIV serodiscordant couples - assessment of attitudes, knowledge, and practices.

    Science.gov (United States)

    Scherer, Matthew L; Douglas, Nataki C; Churnet, Bethlehem H; Grossman, Lisa C; Kline, Melissa; Yin, Michael T; Sauer, Mark V; Olender, Susan A

    2014-01-01

    Human immunodeficiency virus (HIV) serodiscordant couples are at risk of sexual transmission of HIV between the infected and uninfected partner. We assessed New York area care providers for people living with HIV regarding attitudes, knowledge, and practice patterns toward fertility and conception in serodiscordant couples. Data were collected via a survey distributed in October 2013. Seventeen percent of respondents reported prescribing antiretroviral preexposure prophylaxis (PrEP) for a woman in a serodiscordant couple, and 38% percent of respondents reported having counseled serodiscordant couples on timed, unprotected intercourse without PrEP. Respondents who reported being "very" familiar with the data on HIV transmission in serodiscordant couples were more likely to report counseling their patients in timed, unprotected intercourse compared with those who reported less familiarity with the data (41% vs. 8%, p = 0.001). Although only 20% reported being "very" or "somewhat" familiar with the data on the safety of sperm washing with intrauterine insemination, those who did were more likely to have reported referring a patient for assisted reproductive technology (61% vs. 32%, p = 0.006). Effective patient counseling and referral for appropriate reproductive options were associated with knowledge of the literature pertaining to these options. This emphasizes the need for further provider education on reproductive options and appropriate counseling for serodiscordant couples.

  20. Requirements and ontology for a G protein-coupled receptor oligomerization knowledge base

    Directory of Open Access Journals (Sweden)

    Parmentier Marc

    2007-05-01

    Full Text Available Abstract Background G Protein-Coupled Receptors (GPCRs are a large and diverse family of membrane proteins whose members participate in the regulation of most cellular and physiological processes and therefore represent key pharmacological targets. Although several bioinformatics resources support research on GPCRs, most of these have been designed based on the traditional assumption that monomeric GPCRs constitute the functional receptor unit. The increase in the frequency and number of reports about GPCR dimerization/oligomerization and the implication of oligomerization in receptor function makes necessary the ability to store and access information about GPCR dimers/oligomers electronically. Results We present here the requirements and ontology (the information scheme to describe oligomers and associated concepts and their relationships for an information system that can manage the elements of information needed to describe comprehensively the phenomena of both homo- and hetero-oligomerization of GPCRs. The comprehensive information management scheme that we plan to use for the development of an intuitive and user-friendly GPCR-Oligomerization Knowledge Base (GPCR-OKB is the result of a community dialog involving experimental and computational colleagues working on GPCRs. Conclusion Our long term goal is to disseminate to the scientific community organized, curated, and detailed information about GPCR dimerization/oligomerization and its related structural context. This information will be reported as close to the data as possible so the user can make his own judgment on the conclusions drawn for a particular study. The requirements and ontology described here will facilitate the development of future information systems for GPCR oligomers that contain both computational and experimental information about GPCR oligomerization. This information is freely accessible at http://www.gpcr-okb.org.

  1. KNOWLEDGE MANAGEMENT AND INTELLECTUAL CAPITAL MANAGEMENT COUPLED TO QUALITY MANAGEMENT SYSTEM LEAD TO BUSINESS SUCCESS

    Directory of Open Access Journals (Sweden)

    Stevan Živojinović

    2009-03-01

    Full Text Available From the vantage point of contemporary management paradigm shift and new knowledge-based economy, we underscore the importance of relations and support of quality management system - QMS (according to ISO 9001 standard for management of knowledge and intellectual capital. QMS implementation, documenting, application, maintenance and continuous improvement, as a catalyst of effective organization management, provides a foundation for effective knowledge management and intellectual capital enlargement, via knowledge, skills, management systems, procedures, information and product flow, culture, inovation, relations with customers and other stakeholders. Simultaneous implementation and dynamic interaction of these advanced management concepts intended to attain competitive advantage can result in synergic effects and improved performance. From the perspective of knowledge, as a central unifying notion, organizational behavior based on learning influences long-term business success, process effectiveness and customer satisfaction.

  2. Modeling multicomponent ionic transport in groundwater with IPhreeqc coupling: Electrostatic interactions and geochemical reactions in homogeneous and heterogeneous domains

    DEFF Research Database (Denmark)

    Muniruzzaman, Muhammad; Rolle, Massimo

    2016-01-01

    The key role of small-scale processes like molecular diffusion and electrochemical migration has been increasingly recognized in multicomponent reactive transport in saturated porous media. In this study, we propose a two-dimensional multicomponent reactive transport model taking into account...... the electrostatic interactions during transport of charged ions in physically and chemically heterogeneous porous media. The modeling approach is based on the local charge balance and on the description of compound-specific and spatially variable diffusive/dispersive fluxes. The multicomponent ionic transport code...

  3. Debye potentials, electromagnetic reciprocity and impedance boundary conditions for efficient analytic approximation of coupling impedances in complex heterogeneous accelerator pipes

    Energy Technology Data Exchange (ETDEWEB)

    Petracca, S. [Salerno Univ. (Italy)

    1996-08-01

    Debye potentials, the Lorentz reciprocity theorem, and (extended) Leontovich boundary conditions can be used to obtain simple and accurate analytic estimates of the longitudinal and transverse coupling impedances of (piecewise longitudinally uniform) multi-layered pipes with non simple transverse geometry and/or (spatially inhomogeneous) boundary conditions. (author)

  4. Coupling of solar photoelectro-Fenton with a BDD anode and solar heterogeneous photocatalysis for the mineralization of the herbicide atrazine.

    Science.gov (United States)

    Garza-Campos, Benjamín R; Guzmán-Mar, Jorge Luis; Reyes, Laura Hinojosa; Brillas, Enric; Hernández-Ramírez, Aracely; Ruiz-Ruiz, Edgar J

    2014-02-01

    Here, the synergetic effect of coupling solar photoelectro-Fenton (SPEF) and solar heterogeneous photocatalysis (SPC) on the mineralization of 200mL of a 20mg L(-1) atrazine solution, prepared from the commercial herbicide Gesaprim, at pH 3.0 was studied. Uniform, homogeneous and adherent anatase-TiO2 films onto glass spheres of 5mm diameter were prepared by the sol-gel dip-coating method and used as catalyst for SPC. However, this procedure yielded a poor removal of the substrate because of the low oxidation ability of positive holes and OH formed at the catalyst surface to destroy it. Atrazine decay was improved using anodic oxidation (AO), electro-Fenton (EF), SPEF and coupled SPEF-SPC at 100mA. The electrolytic cell contained a boron-doped diamond (BDD) anode and H2O2 was generated at a BDD cathode fed with an air flow. The removal and mineralization of atrazine increased when more oxidizing agents were generated in the sequence AOatrazine was inhibited by the production of cyanuric acid, which was the main byproduct detected at the end of the coupled SPEF-SPC process.

  5. Coupling Knowledge with GIS Operations: The Benefits of Extended Operation Descriptions

    Directory of Open Access Journals (Sweden)

    Barbara Hofer

    2017-02-01

    Full Text Available The automated development of spatial analysis workflows is one of the envisioned benefits of Web services that provide geoprocessing functionality. Automated workflow development requires the means to translate a user objective into a series of geographic information system (GIS operations and to evaluate the match between data and operations. Even though full automation is yet out of reach, users benefit from formalized knowledge about operations that is available during workflow development. This article presents user support during workflow development based on a recent approach to extended operation descriptions. User support thereby focuses on the discovery of operations across GIS tools and the validation of chains of spatial analysis operations. The required knowledge about operations is stored in a knowledge base, which builds on an approach called geooperators and extends the geooperator approach with a data-type ontology for describing the interfaces of geooperators and for expressing constraints of geooperator inputs. The advantages of the knowledge base are demonstrated for the construction of a multi-criteria decision making workflow. This workflow contains a set of pre-processing tasks for the input datasets and eventually the calculation of a cost distance raster. A critical discussion of the complexity of the knowledge base and a comparison with existing approaches complement this contribution.

  6. Knowledges

    DEFF Research Database (Denmark)

    Berling, Trine Villumsen

    2012-01-01

    and reflectivism. Bourdieu, on the contrary, lets the challenge to the theory/reality distinction spill over into a challenge to the theory/practice distinction by thrusting the scientist in the foreground as not just a factor (discourse/genre) but as an actor. In this way, studies of IR need to include a focus......Scientific knowledge in international relations has generally focused on an epistemological distinction between rationalism and reflectivism over the last 25 years. This chapter argues that this distinction has created a double distinction between theory/reality and theory/practice, which works...... as a ghost distinction structuring IR research. While reflectivist studies have emphasised the impossibility of detached, objective knowledge production through a dissolution of the theory/reality distinction, the theory/practice distinction has been left largely untouched by both rationalism...

  7. Coupling visualization and data analysis for knowledge discovery from multi-dimensional scientific data.

    Science.gov (United States)

    Rübel, Oliver; Ahern, Sean; Bethel, E Wes; Biggin, Mark D; Childs, Hank; Cormier-Michel, Estelle; Depace, Angela; Eisen, Michael B; Fowlkes, Charless C; Geddes, Cameron G R; Hagen, Hans; Hamann, Bernd; Huang, Min-Yu; Keränen, Soile V E; Knowles, David W; Hendriks, Cris L Luengo; Malik, Jitendra; Meredith, Jeremy; Messmer, Peter; Prabhat; Ushizima, Daniela; Weber, Gunther H; Wu, Kesheng

    2010-05-01

    Knowledge discovery from large and complex scientific data is a challenging task. With the ability to measure and simulate more processes at increasingly finer spatial and temporal scales, the growing number of data dimensions and data objects presents tremendous challenges for effective data analysis and data exploration methods and tools. The combination and close integration of methods from scientific visualization, information visualization, automated data analysis, and other enabling technologies -such as efficient data management- supports knowledge discovery from multi-dimensional scientific data. This paper surveys two distinct applications in developmental biology and accelerator physics, illustrating the effectiveness of the described approach.

  8. Coupling Visualization and Data Analysis for Knowledge Discovery from Multi-dimensional Scientific Data

    Energy Technology Data Exchange (ETDEWEB)

    Rubel, Oliver; Ahern, Sean; Bethel, E. Wes; Biggin, Mark D.; Childs, Hank; Cormier-Michel, Estelle; DePace, Angela; Eisen, Michael B.; Fowlkes, Charless C.; Geddes, Cameron G. R.; Hagen, Hans; Hamann, Bernd; Huang, Min-Yu; Keranen, Soile V. E.; Knowles, David W.; Hendriks, Chris L. Luengo; Malik, Jitendra; Meredith, Jeremy; Messmer, Peter; Prabhat,; Ushizima, Daniela; Weber, Gunther H.; Wu, Kesheng

    2010-06-08

    Knowledge discovery from large and complex scientific data is a challenging task. With the ability to measure and simulate more processes at increasingly finer spatial and temporal scales, the growing number of data dimensions and data objects presents tremendous challenges for effective data analysis and data exploration methods and tools. The combination and close integration of methods from scientific visualization, information visualization, automated data analysis, and other enabling technologies"such as efficient data management" supports knowledge discovery from multi-dimensional scientific data. This paper surveys two distinct applications in developmental biology and accelerator physics, illustrating the effectiveness of the described approach.

  9. Laboratory of alternative energies and hydrogen in ESPOL. Coupling needs and knowledge

    Energy Technology Data Exchange (ETDEWEB)

    Mendieta, E. [Escuela Superior Politecnica del Litoral, Campus Gustavo Galindo, Guayaquil (Ecuador)

    2009-07-01

    The Ecuadorian problems with electricity and oil for the near future are shortly assessed in this paper. The main Ecuadorian universities contribution towards a real solution is also mentioned here. Projected Knowledge Park of ESPOL (PARCON) and its 7 integrated research centers is presented briefly. The integration of multidisciplinary research being developed in ESPOL is one foundation for this Knowledge Park. The results of previous researches like the Hydrogen project will be used to set the first stage database for future R and D initiatives. The University of Applied Science of Stralsund is one formal partner for ESPOL in Alternative Energies and Hydrogen utilization. (orig.)

  10. Coupling visualization and data analysis for knowledge discovery from multi-dimensional scientific data

    Science.gov (United States)

    Rübel, Oliver; Ahern, Sean; Bethel, E. Wes; Biggin, Mark D.; Childs, Hank; Cormier-Michel, Estelle; DePace, Angela; Eisen, Michael B.; Fowlkes, Charless C.; Geddes, Cameron G. R.; Hagen, Hans; Hamann, Bernd; Huang, Min-Yu; Keränen, Soile V. E.; Knowles, David W.; Hendriks, Cris L. Luengo; Malik, Jitendra; Meredith, Jeremy; Messmer, Peter; Prabhat; Ushizima, Daniela; Weber, Gunther H.; Wu, Kesheng

    2013-01-01

    Knowledge discovery from large and complex scientific data is a challenging task. With the ability to measure and simulate more processes at increasingly finer spatial and temporal scales, the growing number of data dimensions and data objects presents tremendous challenges for effective data analysis and data exploration methods and tools. The combination and close integration of methods from scientific visualization, information visualization, automated data analysis, and other enabling technologies —such as efficient data management— supports knowledge discovery from multi-dimensional scientific data. This paper surveys two distinct applications in developmental biology and accelerator physics, illustrating the effectiveness of the described approach. PMID:23762211

  11. Stochastic Resonance in an Array of Locally-Coupled McCulloch-Pitts Neurons with Population Heterogeneity

    Science.gov (United States)

    Utagawa, Akira; Sahashi, Tohru; Asai, Tetsuya; Amemiya, Yoshihito

    We found a new class of stochastic resonance (SR) in a simple neural network that consists of i) photoreceptors generating nonuniform outputs for common inputs with random offsets, ii) an ensemble of noisy McCulloch-Pitts (MP) neurons each of which has random threshold values in the temporal domain, iii) local coupling connections between the photoreceptors and the MP neurons with variable receptive fields (RFs), iv) output cells, and v) local coupling connections between the MP neurons and the output cells. We calculated correlation values between the inputs and the outputs as a function of the RF size and intensities of the random components in photoreceptors and the MP neurons. We show the existence of “optimal noise intensities” of the MP neurons under the nonidentical photoreceptors and “nonzero optimal RF sizes, ” which indicated that optimal correlation values of this SR model were determined by two critical parameters; noise intensities (well-known) and RF sizes as a new parameter.

  12. Au3+/Au0 Supported on Chromium(III Terephthalate Metal Organic Framework (MIL-101 as an Efficient Heterogeneous Catalystfor Three-Component Coupling Synthesis of Propargylamines

    Directory of Open Access Journals (Sweden)

    Lili Liu

    2017-01-01

    Full Text Available Post-synthesis modification is a useful method for the functionalization of metal–organic frameworks (MOFs. A novel catalyst Au@MIL-101-ED-SA (ED = ethylenediamine, SA = salicylaldehyde, containing coexisting Au3+ ions and Au0 nanoparticles, was prepared successfully by post-synthesis modification with ethylenediamine, salicylaldehyde and gold. Gold nanoparticles supported on MIL-101 (Au@MIL-101 were prepared successfully by the impregnation method. Au@MIL-101-ED-SA and Au@MIL-101 were characterized by N2 adsorption–desorption, X-ray diffraction, infrared spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy, and inductively coupled plasma-optical emission spectrometry. Au@MIL-101-ED-SA and Au@MIL-101 were applied as environmentally friendly catalysts in the three-component coupling reaction of aldehydes, amines, and alkynes for the preparation of diverse propargylamines. Au@MIL-101-ED-SA contained a fraction of cationic gold (Au3+/Au0 = 0.9 and showed higher catalytic activity than Au@MIL-101, which was prepared by the impregnation method. Furthermore, the reactions were performed under heterogeneous conditions and the novel catalyst was successfully recycled for four consecutive runs.

  13. Au3+/Au0 Supported on Chromium(III) Terephthalate Metal Organic Framework (MIL-101) as an Efficient Heterogeneous Catalystfor Three-Component Coupling Synthesis of Propargylamines

    Science.gov (United States)

    Liu, Lili; Tai, Xishi; Zhou, Xiaojing

    2017-01-01

    Post-synthesis modification is a useful method for the functionalization of metal–organic frameworks (MOFs). A novel catalyst Au@MIL-101-ED-SA (ED = ethylenediamine, SA = salicylaldehyde), containing coexisting Au3+ ions and Au0 nanoparticles, was prepared successfully by post-synthesis modification with ethylenediamine, salicylaldehyde and gold. Gold nanoparticles supported on MIL-101 (Au@MIL-101) were prepared successfully by the impregnation method. Au@MIL-101-ED-SA and Au@MIL-101 were characterized by N2 adsorption–desorption, X-ray diffraction, infrared spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy, and inductively coupled plasma-optical emission spectrometry. Au@MIL-101-ED-SA and Au@MIL-101 were applied as environmentally friendly catalysts in the three-component coupling reaction of aldehydes, amines, and alkynes for the preparation of diverse propargylamines. Au@MIL-101-ED-SA contained a fraction of cationic gold (Au3+/Au0 = 0.9) and showed higher catalytic activity than Au@MIL-101, which was prepared by the impregnation method. Furthermore, the reactions were performed under heterogeneous conditions and the novel catalyst was successfully recycled for four consecutive runs. PMID:28772462

  14. Au(3+)/Au⁰ Supported on Chromium(III) Terephthalate Metal Organic Framework (MIL-101) as an Efficient Heterogeneous Catalystfor Three-Component Coupling Synthesis of Propargylamines.

    Science.gov (United States)

    Liu, Lili; Tai, Xishi; Zhou, Xiaojing

    2017-01-25

    Post-synthesis modification is a useful method for the functionalization of metal-organic frameworks (MOFs). A novel catalyst Au@MIL-101-ED-SA (ED = ethylenediamine, SA = salicylaldehyde), containing coexisting Au(3+) ions and Au⁰ nanoparticles, was prepared successfully by post-synthesis modification with ethylenediamine, salicylaldehyde and gold. Gold nanoparticles supported on MIL-101 (Au@MIL-101) were prepared successfully by the impregnation method. Au@MIL-101-ED-SA and Au@MIL-101 were characterized by N₂ adsorption-desorption, X-ray diffraction, infrared spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy, and inductively coupled plasma-optical emission spectrometry. Au@MIL-101-ED-SA and Au@MIL-101 were applied as environmentally friendly catalysts in the three-component coupling reaction of aldehydes, amines, and alkynes for the preparation of diverse propargylamines. Au@MIL-101-ED-SA contained a fraction of cationic gold (Au(3+)/Au⁰ = 0.9) and showed higher catalytic activity than Au@MIL-101, which was prepared by the impregnation method. Furthermore, the reactions were performed under heterogeneous conditions and the novel catalyst was successfully recycled for four consecutive runs.

  15. 跨学科创新团队知识异质性与绩效关系研究%The relationship between the knowledge heterogeneity and innovation performances of the interdisciplinary teams

    Institute of Scientific and Technical Information of China (English)

    王兴元; 姬志恒

    2013-01-01

    Based on the theses, the heterogeneity of team knowledge is divided into explicit knowledge heterogeneity, the pseudo tacit knowledge heterogeneity, and the true tacit knowledge heterogeneity. And the relationship between team interaction and the team' s innovation performance is studied. Empirical results show that team explicit knowledge heterogeneity is insignificant to the innovation performance; the pseudo tacit knowledge heterogeneity has a significant positive influence on team communication, team knowledge sharing, work conflict, teamwork, and ultimately promoting the innovation team performance; the true tacit knowledge heterogeneity impedes knowledge sharing, leading to the team interpersonal conflicts, and hindering the team innovation. Regulating variable analysis shows that the team trust is able to significantly adjust the impact relationship between the team communication, knowledge sharing, interpersonal conflict, work conflict, teamwork, and innovation performance.%论文把团队知识异质性分为团队显性知识异质性、团队伪隐性知识异质性、团队真隐性知识异质性,研究了其通过团队互动与团队创新绩效的关系.实证结果表明团队显性知识异质性通过团队互动最终影响团队创新绩效的作用并不显著;团队伪隐性知识的异质性对于团队沟通、团队知识共享、工作冲突、团队协作有显著的正向影响,且最终促进了团队创新绩效;团队真隐性知识异质性阻碍了知识共享,引发了团队人际冲突,这些都阻碍了团队创新.调节变量作用分析结果表明,团队信任能够显著调节团队沟通、知识共享、人际冲突、工作冲突、团队协作对创新绩效的影响关系.

  16. Quantifying the effects of three-dimensional subsurface heterogeneity on Hortonian runoff processes using a fully-coupled numerical, stochastic approach.

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, R M; Kollet, S J

    2007-08-23

    The impact of three-dimensional subsurface heterogeneity on hillslope runoff generated by excess infiltration (so called Hortonian runoff) is examined. A fully-coupled, parallel subsurface overland flow model is used to simulate runoff from an idealized hillslope. Ensembles of correlated, Gaussian random fields of saturated hydraulic conductivity are used to create uncertainty and variability (i.e. structure) due to subsurface heterogeneity. A large number of cases are simulated in a parametric manner with variance of the hydraulic conductivity varied over two orders of magnitude. These cases include rainfall rates above, equal and below the geometric mean of the hydraulic conductivity distribution. These cases are also compared to theoretical considerations of runoff production based on simple assumptions regarding (1) the rainfall rate and the value of hydraulic conductivity in the surface cell using a spatially-indiscriminant approach; and (2) a percolation-theory type approach to incorporate so-called runon. Simulations to test the ergodicity of hydraulic conductivity on hillslope runoff are also performed. Results show three-dimensional features (particularly in the vertical dimension) in the hydraulic conductivity distributions that create shallow perching, which has an important effect on runoff behavior that is fundamentally different in character than previous two dimensional analyses. The simple theories are shown to be very poor predictors of the saturated area that might runoff due to excess infiltration. It is also shown that ergodicity is reached only for a large number of integral scales ({approx}30) and not for cases where the rainfall rate is less than the geometric mean of the saturated hydraulic conductivity.

  17. On the coupled use of sapflow and eddy covariance measurements: environmental impacts on the evapotranspiration of an heterogeneous - wild olives based - Sardinian ecosystem.

    Science.gov (United States)

    Curreli, Matteo; Corona, Roberto; Montaldo, Nicola; Oren, Ram

    2015-04-01

    Sapflow and eddy covariance techniques are attractive methods for evapotranspiration (ET) estimates. We demonstrated that in Mediterranean ecosystems, characterized by an heterogeneous spatial distribution of different plant functional types (PFT) such as grass and trees, the combined use of these techniques becomes essential for the actual ET estimates. Indeed, during the dry summers these water-limited heterogeneous ecosystems are typically characterized by a simple dual PFT system with strong-resistant woody vegetation and bare soil, since grass died. An eddy covariance - micrometeorological tower has been installed over an heterogeneous ecosystem at the Orroli site in Sardinia (Italy) from 2003. The site landscape is a mixture of Mediterranean patchy vegetation types: wild olives, different shrubs and herbaceous species, which died during the summer. Where patchy land cover leads and the surface fluxes from different cover are largely different, ET evaluation may be not robust enough and eddy covariance method hypothesis are not anymore preserved. In these conditions the sapflow measurements, performed by thermodissipation probes, provide robust estimates of the transpiration from woody vegetation. Through the coupled use of the sapflow sensor observations, a 2D footprint model of the eddy covariance tower and high resolution satellite images for the estimate of the foot print land cover map, the eddy covariance measurements can be correctly interpreted, and ET components (bare soil evaporation and woody vegetation transpiration) can be separated. Based on the Granier technique, 33 thermo-dissipation probes have been built and 6 power regulators have been assembled to provide a constant current of 3V to the sensors. The sensors have been installed at the Orroli site into 15 wild olives clumps with different characteristics in terms of tree size, exposition to wind and solar radiation and soil depth. The sap flow sensors outputs are analyzed to estimate

  18. The Mechanisms of Knowledge Heterogeneity on Creativity of Knowledge Teams:An Interactive Cognition Perspective%知识异质性对知识型团队创造力的影响机制:基于互动认知的视角

    Institute of Scientific and Technical Information of China (English)

    吕洁; 张钢

    2015-01-01

    知识型团队的创造力不仅受到团队知识异质性和成员创造力的影响,同时还取决于团队成员之间的认知互动过程。通过391份知识型团队的领导与成员的配对问卷调查,从互动认知的视角,采用多层线性模型分析了认知冲突和任务知识协调对知识异质性与团队及其成员创造力之间关系的影响。研究结果表明,认知冲突在知识异质性和团队及其成员创造力之间有着显著的中介作用;任务知识协调则调节了知识异质性对团队及其成员创造力的影响。当任务知识协调水平高时,知识异质性与团队及其成员的创造力之间的关系均正向显著;当任务知识协调水平低时,知识异质性与团队创造力之间呈倒U型关系,但与个体成员创造力之间的关系并不显著。%In the current era of knowledge economy, organizations are increasingly dependent on knowledge teams to develop creative solutions and respond to the rapidly changing environment. Knowledge teams integrate the unique knowledge and skills of their members and thus have access to alternative perspectives when seeking solutions to problems. Because of this, knowledge heterogeneity is a typical characteristic of knowledge teams, and is considered by many researchers as an important factor that inspires team creativity. However, we are also led to believe that knowledge heterogeneity does not always impact positively on team creativity, as it may limit the effective knowledge sharing among team members and create a lot of negative issues. Currently, little is known about the complexity of the mechanisms through which knowledge heterogeneity works on team creativity. This study contributes to the existing literature by investigating such a complexity. In our study, we posit that the creativity of knowledge teams is not only influenced by knowledge heterogeneity and individual team member creativity, but also depends critically on

  19. A Knowledge integrated Research Based on Team Knowledge Heterogeneity Structure%基于团队知识异质性结构的知识整合研究

    Institute of Scientific and Technical Information of China (English)

    李夏楠; 倪旭东

    2012-01-01

    Knowledge sharing and knowledge conflict are becoming more and more important in a team work. The occurrence of knowledge sharing and knowledge conflict is contributed to team members' different knowledge. Generally speaking, knowledge sharing and knowledge conflict are positively related to knowledge differences , but when the difference of knowledge is too big, knowledge sharing might be reduced instead and knowledge conflict may be changed into relationship conflicts. Some features such as age are also affecting knowledge sharing and knowledge conflict in degree size.%根源于团队成员知识异质性的知识共享和知识冲突是知识管理中两个重要的要素,它们对团队乃至整个组织的运作结果有着较大的影响,这就要求构建一个能解释知识差异和知识共享以及知识冲突之间内在关系的知识整合框架.通过分析团队成员知识异质性的程度分布结构和团队异质性特征互动结构两个方面,建立导致知识共享和知识冲突程度大小的理论模型.

  20. Deriving Accurate Interproton Distances from ROESY Spectra with Limited Knowledge of Scalar Coupling Constants via the CARNIVAL Algorithm. An Iterative Complete-Relaxation-Matrix Approach

    Science.gov (United States)

    Liu, H.; Banville, D. L.; Basus, V. J.; James, T. L.

    A method (termed CARNIVAL) for accurately determining distances from proton homonuclear rotating-frame Overhauser effect spectroscopy (ROESY) is described. The method entails an iterative calculation of the relaxation matrix using methodology introduced with the MARDIGRAS algorithm for analysis of two-dimensional nuclear Overhauser effect spectra (B. A. Borgias and T. L. James, J. Magn. Reson.87, 475, 1990). The situation is complicated in the case of ROESY as spectral peak intensities are influenced by resonance offset and contributions from homonuclear Hartmann-Hahn (HOHAHA) transfer if the nuclear spins are related by scalar coupling. The effects of spin-locking field strength on distance determinations and the ensuing distance errors incurred when HOHAHA corrections are made with limited knowledge of scalar ( J) coupling information have been evaluated using simulated ROESY intensities with a model peptide structure. It has been demonstrated that accurate distances can be obtained with little or no explicit knowledge of the homonuclear coupling constants over a moderate range of spin-locking field strengths. The CARNIVAL algorithm has been utilized to determine distances in a decapeptide using experimental ROESY data without measured coupling constants.

  1. Heterogeneity in breast cancer.

    Science.gov (United States)

    Polyak, Kornelia

    2011-10-01

    Breast cancer is a heterogeneous disease. There is a high degree of diversity between and within tumors as well as among cancer-bearing individuals, and all of these factors together determine the risk of disease progression and therapeutic resistance. Advances in technologies such as whole-genome sequencing and functional viability screens now allow us to analyze tumors at unprecedented depths. However, translating this increasing knowledge into clinical practice remains a challenge in part due to tumor evolution driven by the diversity of cancer cell populations and their microenvironment. The articles in this Review series discuss recent advances in our understanding of breast tumor heterogeneity, therapies tailored based on this knowledge, and future ways of assessing and treating heterogeneous tumors.

  2. Investigating the Impact of Surface Heterogeneity on the Convective Boundary Layer Over Urban Areas Through Coupled Large-Eddy Simulation and Remote Sensing

    Science.gov (United States)

    Dominguez, Anthony; Kleissl, Jan P.; Luvall, Jeffrey C.

    2011-01-01

    Large-eddy Simulation (LES) was used to study convective boundary layer (CBL) flow through suburban regions with both large and small scale heterogeneities in surface temperature. Constant remotely sensed surface temperatures were applied at the surface boundary at resolutions of 10 m, 90 m, 200 m, and 1 km. Increasing the surface resolution from 1 km to 200 m had the most significant impact on the mean and turbulent flow characteristics as the larger scale heterogeneities became resolved. While previous studies concluded that scales of heterogeneity much smaller than the CBL inversion height have little impact on the CBL characteristics, we found that further increasing the surface resolution (resolving smaller scale heterogeneities) results in an increase in mean surface heat flux, thermal blending height, and potential temperature profile. The results of this study will help to better inform sub-grid parameterization for meso-scale meteorological models. The simulation tool developed through this study (combining LES and high resolution remotely sensed surface conditions) is a significant step towards future studies on the micro-scale meteorology in urban areas.

  3. Integrated design of RMS based on coupling modeling and knowledge flow%基于耦合建模与知识流的RMS一体化设计

    Institute of Scientific and Technical Information of China (English)

    徐永成; 李岳; 陈循

    2013-01-01

    针对国内外研究热点和难点——装备可靠性、维修性、保障性(reliability,maintainability and supportability,RMS)一体化设计,提出其中的瓶颈是RMS之间的强耦合机制及其设计知识流动控制问题.为此,分析、论证并提出了一种装备RMS一体化设计的创新研究方案:首先采用具有严格数学基础的图论方法——分层加权有向图进行RMS建模,以系统、科学、客观地刻画RMS强耦合关系;引入图书情报、管理工程中的知识流理论以实现RMS耦合设计知识的流动控制;采用模糊粗糙集理论以解决RMS不确定知识问题.可为装备RMS一体化设计理论的发展提供一种创新的、可行的参考思路.%The integrated design of reliability,maintainability and supportability (RMS) is one of key technical challenges and research hot spots in the engineering and academic field at home and abroad.Although achievements have been attained in the individual engineering of reliability,maintainability and supportability,the problem of strong-coupling between RMS and control of design knowledge has not been resolved up to now.The strong-coupling between RMS characteristic parameters and their logic relations results in the intersectant design processes and knowledge of RMS,which affects the real integration of RMS data and design tools.In this paper one research solution of RMS integrated design is presented.Firstly,the layered weighted digraphs method is introduced to model and decouple this strong-coupling relationship scientifically and impersonally because the graph theory has the strict foundation of mathematics.Then,the knowledge flow theory of library and management science is introduced to lead the scientific flow of design knowledge between the RMS coupling fields.Finally,the fuzzy rough sets theory is adopted to study the problems of uncertain knowledge and case data missing under coupling RMS case.This research solution can provide one new idea and

  4. Research on the Influence Mechanism of Heterogeneity to Knowledge Transfer Process in Design -type Knowledge Work%团队异质性影响企业内部知识转移过程机制研究--以设计型知识工作团队为例

    Institute of Scientific and Technical Information of China (English)

    余呈先

    2016-01-01

    以“团队异质性—交互记忆系统—知识转移过程”的研究思路,通过问卷调查法和结构方程模型分析,探索设计型知识工作团队异质性影响内部知识转移的机理。研究发现:高工作相关异质性显著影响交互记忆系统;交互记忆系统正向影响知识转移过程;团队异质性与知识转移过程之间存在显著相关关系;高工作相关异质性与知识转移表现出 U 型相关;低工作相关异质性与知识转移是负向相关;交互记忆系统在团队异质性和知识转移过程中具有完全中介作用。研究从交互记忆系统形成角度提出优化知识转移的策略:优化团队知识结构;构建知识地图;不断维护团队的交互记忆系统;营造团队内部交流互动的良好氛围,构建知识转移的有利手段。%Through the questionnaire survey and the structure equation model analysis,this paper explores the mechanism of heterogeneity on the influence of internal knowledge transfer within design -type knowledge work team.Its research route follows "Team Heterogeneity—Transactive Memory System—Knowledge Transfer Process".The study finds that the het-erogeneity is significantly influential on transactive memory systems;transactive memory system has positive impact on the knowledge transfer process;there is a significant relevant relations between word team heterogeneity and knowledge transfer process;high team work heterogeneity and the knowledge transfer process have inverted u -shaped curve relationship;low team work related heterogeneity is negative correlated with the process of knowledge transfer;transactive memory system plays a partial mediating role between the high heterogeneity and process of knowledge transfer.Finally,it puts forward the optimization strategy of knowledge transfer,including optimizing team structure,constructing knowledge map,maintaining team's transactive memory system,creating atmosphere of team

  5. A knowledge-based system for discovering ecological interactions in biodiversity data-stores of heterogeneous specimen-records: a case-study of flower-visiting ecology

    CSIR Research Space (South Africa)

    Coetzer, W

    2014-11-01

    Full Text Available and modeling approach are potentially of general use in representing knowledge of animal behavior and ecological interactions, and in engineering semantic interoperability between data-stores containing behavioral ecology data....

  6. Advanced techniques for the storage and use of very large, heterogeneous spatial databases. The representation of geographic knowledge: Toward a universal framework. [relations (mathematics)

    Science.gov (United States)

    Peuquet, Donna J.

    1987-01-01

    A new approach to building geographic data models that is based on the fundamental characteristics of the data is presented. An overall theoretical framework for representing geographic data is proposed. An example of utilizing this framework in a Geographic Information System (GIS) context by combining artificial intelligence techniques with recent developments in spatial data processing techniques is given. Elements of data representation discussed include hierarchical structure, separation of locational and conceptual views, and the ability to store knowledge at variable levels of completeness and precision.

  7. Heterogeneous Catalysts

    NARCIS (Netherlands)

    Dakka, J.; Sheldon, R.A.; Sanderson, W.A.

    1997-01-01

    Abstract of GB 2309655 (A) Heterogeneous catalysts comprising one or more metal compounds selected from the group consisting of tin, molybdenum, tungsten, zirconium and selenium compounds deposited on the surface of a silicalite are provided. Preferably Sn(IV) and/or Mo(VI) are employed. The cat

  8. A Copper-Based Metal-Organic Framework as an Efficient and Reusable Heterogeneous Catalyst for Ullmann and Goldberg Type C–N Coupling Reactions

    Directory of Open Access Journals (Sweden)

    Wei Long

    2015-11-01

    Full Text Available A highly porous metal-organic framework (Cu-TDPAT, constructed from a paddle-wheel type dinuclear copper cluster and 2,4,6-tris(3,5-dicarboxylphenylamino-1,3,5-triazine (H6TDPAT, has been tested in Ullmann and Goldberg type C–N coupling reactions of a wide range of primary and secondary amines with halobenzenes, affording the corresponding N-arylation compounds in moderate to excellent yields. The Cu-TDPAT catalyst could be easily separated from the reaction mixtures by simple filtration, and could be reused at least five times without any significant degradation in catalytic activity.

  9. Coupling of acrylic dyeing wastewater treatment by heterogeneous Fenton oxidation in a continuous stirred tank reactor with biological degradation in a sequential batch reactor.

    Science.gov (United States)

    Esteves, Bruno M; Rodrigues, Carmen S D; Boaventura, Rui A R; Maldonado-Hódar, F J; Madeira, Luís M

    2016-01-15

    This work deals with the treatment of a recalcitrant effluent, from the dyeing stage of acrylic fibres, by combination of the heterogeneous Fenton's process in a continuous stirred tank reactor (CSTR) with biological degradation in a sequential batch reactor (SBR). Three different catalysts (a commercial Fe/ZSM-5 zeolite and two distinct Fe-containing activated carbons - ACs - prepared by wet impregnation of iron acetate and iron nitrate) were employed on the Fenton's process, and afterwards a parametric study was carried out to determine the effect of the main operating conditions, namely the hydrogen peroxide feed concentration, temperature and contact time. Under the best operating conditions found, using the activated carbon impregnated with iron nitrate, 62.7% of discolouration and 39.9% of total organic carbon (TOC) reduction were achieved, at steady-state. Furthermore, a considerable increase in the effluent's biodegradability was attained (BOD5:COD ratio increased from <0.001 to 0.27 and SOUR - specific oxygen uptake rate - from <0.2 to 11.1 mg O2/(gVSS·h)), alongside a major decrease in its toxicity (from 92.1 to 94.0% of Vibrio fischeri inhibition down to 6.9-9.9%). This allowed the application of the subsequent biological degradation stage. The combination of the two processes provided a treated effluent that clearly complies with the legislated discharge limits. It was also found that the iron leaching from the three catalysts tested was very small in all runs, a crucial factor for the stability and long-term use of such materials.

  10. Impact of static and dynamic A-form heterogeneity on the determination of RNA global structural dynamics using NMR residual dipolar couplings

    Energy Technology Data Exchange (ETDEWEB)

    Musselman, Catherine [University of Michigan, Department of Chemistry, Biophysics Research Division, and Program in Bioinformatics (United States); Pitt, Stephen W. [Johnson and Johnson Inc (United States); Gulati, Kush; Foster, Lesley L.; Andricioaei, Ioan; Al-Hashimi, Hashim M. [University of Michigan, Department of Chemistry, Biophysics Research Division, and Program in Bioinformatics (United States)], E-mail: hashimi@umich.edu

    2006-12-15

    We examined how static and dynamic deviations from the idealized A-form helix propagate into errors in the principal order tensor parameters determined using residual dipolar couplings (rdcs). A 20-ns molecular dynamics (MD) simulation of the HIV-1 transactivation response element (TAR) RNA together with a survey of spin relaxation studies of RNA dynamics reveals that pico-to-nanosecond local motions in non-terminal Watson-Crick base-pairs will uniformly attenuate base and sugar one bond rdcs by {approx}7%. Gaussian distributions were generated for base and sugar torsion angles through statistical comparison of 40 RNA X-ray structures solved to <3.0 A resolution. For a typical number ({>=}11) of one bond C-H base and sugar rdcs, these structural deviations together with rdc uncertainty (1.5 Hz) lead to average errors in the magnitude and orientation of the principal axis of order that are <9% and <4 deg., respectively. The errors decrease to <5% and <4 deg. for {>=}17 rdcs. A protocol that allows for estimation of error in A-form order tensors due to both angular deviations and rdc uncertainty (Aform-RDC) is validated using theoretical simulations and used to analyze rdcs measured previously in TAR in the free state and bound to four distinct ligands. Results confirm earlier findings that the two TAR helices undergo large changes in both their mean relative orientation and dynamics upon binding to different targets.

  11. Heterogeneity of monoclonal antibodies.

    Science.gov (United States)

    Liu, Hongcheng; Gaza-Bulseco, Georgeen; Faldu, Dinesh; Chumsae, Chris; Sun, Joanne

    2008-07-01

    Heterogeneity of monoclonal antibodies is common due to the various modifications introduced over the lifespan of the molecules from the point of synthesis to the point of complete clearance from the subjects. The vast number of modifications presents great challenge to the thorough characterization of the molecules. This article reviews the current knowledge of enzymatic and nonenzymatic modifications of monoclonal antibodies including the common ones such as incomplete disulfide bond formation, glycosylation, N-terminal pyroglutamine cyclization, C-terminal lysine processing, deamidation, isomerization, and oxidation, and less common ones such as modification of the N-terminal amino acids by maleuric acid and amidation of the C-terminal amino acid. In addition, noncovalent associations with other molecules, conformational diversity and aggregation of monoclonal antibodies are also discussed. Through a complete understanding of the heterogeneity of monoclonal antibodies, strategies can be employed to better identify the potential modifications and thoroughly characterize the molecules.

  12. Floodplain heterogeneity and meander migration

    Science.gov (United States)

    The impact of horizontal heterogeneity of floodplain soils on rates and patterns of meander migration is analyzed with a Ikeda et al. (1981)-type model for hydrodynamics and bed morphodynamics, coupled with a physically-based bank erosion model according to the approach developed by Motta et al. (20...

  13. Viewpoint – Water Variability, Soil Nutrient Heterogeneity and Market Volatility – Why Sub-Saharan Africa’s Green Revolution Will Be Location-Specific and Knowledge-Intensive

    Directory of Open Access Journals (Sweden)

    Pieter van der Zaag

    2010-02-01

    Full Text Available In his interesting Viewpoint article in Water Alternatives, Bruce Lankford suggests that an African Green Revolution cannot come about without irrigation. But he does not convincingly explain why irrigated areas expand only very slowly. This viewpoint article argues that grain yields have remained stagnant in Africa because of high temporal rainfall variability, significant spatial soil nutrient heterogeneity, and weak and volatile markets. This combination calls for location-specific interventions that are aimed at enhancing farmers’ capacity to buffer water variations and address nutrient deficits. This finding is consistent with what Lankford dismisses as an "atomised" approach, but which would preferably be called a farmer-centred approach. Thus a massive investment in African agriculture is indeed required, primarily focused on the creation of knowledge that does justice to the local variation in water and nutrient availability. It should aim to empower farmers to experiment and be innovative, and remake agricultural extension and agricultural engineering exciting with cutting-edge disciplines. Irrigation may then emerge as the right thing to do.

  14. Synthesizing Knowledge on Internet of Things (IoT)

    DEFF Research Database (Denmark)

    Liu, Fei; Tan, Chee-Wee; Lim, Eric T. K.

    2016-01-01

    Research on Internet of Things (IoT) has been booming for past couple of years due to technological advances and its potential for application. Nonetheless, the rapid growth of IoT articles as well as the heterogeneous nature of IoT pose challenges in synthesizing prior research on the phenomenon...... of knowledge on IoT and pinpointing the most influential ideas to-date on the topic....

  15. Modelling Configuration Knowledge in Heterogeneous Product Families

    DEFF Research Database (Denmark)

    Queva, Matthieu Stéphane Benoit; Männistö, Tomi; Ricci, Laurent

    2011-01-01

    Product configuration systems play an important role in the development of Mass Customisation. The configuration of complex product families may nowadays involve multiple design disciplines, e.g. hardware, software and services. In this paper, we present a conceptual approach for modelling the va...

  16. Chimera states in two populations with heterogeneous phase-lag

    OpenAIRE

    Martens, Erik Andreas; Bick, Christian; Panaggio, Mark J.

    2016-01-01

    The simplest network of coupled phase-oscillators exhibiting chimera states is given by two populations with disparate intra- and inter-population coupling strengths. We explore the effects of heterogeneous coupling phase-lags between the two populations. Such heterogeneity arises naturally in various settings, for example as an approximation to transmission delays, excitatory-inhibitory interactions, or as amplitude and phase responses of oscillators with electrical or mechanical coupling. W...

  17. Heterogeneity and Microeconometrics Modelling

    DEFF Research Database (Denmark)

    Browning, Martin; Carro, Jesus

    Presented at the 2005 Econometric Society World Congress Plenary Session on "Modelling Heterogeneity". We survey the treatment of heterogeneity in applied microeconometrics analyses. There are three themes. First, there is usually much more heterogeneity than empirical researchers allow for. Seco...

  18. Information flow in heterogeneously interacting systems.

    Science.gov (United States)

    Yamaguti, Yutaka; Tsuda, Ichiro; Takahashi, Yoichiro

    2014-02-01

    Motivated by studies on the dynamics of heterogeneously interacting systems in neocortical neural networks, we studied heterogeneously-coupled chaotic systems. We used information-theoretic measures to investigate directions of information flow in heterogeneously coupled Rössler systems, which we selected as a typical chaotic system. In bi-directionally coupled systems, spontaneous and irregular switchings of the phase difference between two chaotic oscillators were observed. The direction of information transmission spontaneously switched in an intermittent manner, depending on the phase difference between the two systems. When two further oscillatory inputs are added to the coupled systems, this system dynamically selects one of the two inputs by synchronizing, selection depending on the internal phase differences between the two systems. These results indicate that the effective direction of information transmission dynamically changes, induced by a switching of phase differences between the two systems.

  19. Temperature chaos and quenched heterogeneities

    Science.gov (United States)

    Barucca, Paolo; Parisi, Giorgio; Rizzo, Tommaso

    2014-03-01

    We present a treatable generalization of the Sherrington-Kirkpatrick (SK) model which introduces correlations in the elements of the coupling matrix through multiplicative disorder on the single variables and investigate the consequences on the phase diagram. We define a generalized qEA parameter and test the structural stability of the SK results in this correlated case evaluating the de Almeida-Thouless line of the model. As a main result we demonstrate the increase of temperature chaos effects due to heterogeneities.

  20. 基于知识耦合的平面设计信息编码研究%Study on Information Decoding of Graphic Design Based on Knowledge Coupling

    Institute of Scientific and Technical Information of China (English)

    杜鹤民; 张淑梅

    2012-01-01

    分析了平面设计的信息特征,讨论了平面设计过程中的信息编码与平面设计作品解读中的信息解码关系。研究指出,平面设计作品成败的关键在于其信息传达的效率,即信息编码的优劣。在分析信息编码的基础上,从认知的角度提出了知识耦合的概念,指出实现头脑中知识与外部知识的耦合,即隐性知识与显性知识的匹配是实现信息理想传达的有效方法。最后通过标志设计的优秀案例验证了成功的平面设计作品中存在的知识耦合关系。%It analyzed the information characteristics of the graphic design, discussed the information decoding relationship between the information coding and graphic design work in the processing of graphic design. It pointed out, the key of success or failure for graphic design work was due to the efficiency of information communication, namely information decoding quality. Based on the analysis of the information encoding, it put forward the concept of knowledge coupling from the cognitive perspective, and pointed out that realizing the couple of brain' s knowledge and external knowledge (namely the matching of implicit knowledge and explicit knowledge) was a effective method which could realize the effective information transfer(namely ideal communication). Finally, it proved that there was the relationship of knowledge coupling in the successful graphic design work through analyzing the logo design case.

  1. Coupling strength versus coupling impact in nonidentical bidirectionally coupled dynamics

    Science.gov (United States)

    Laiou, Petroula; Andrzejak, Ralph G.

    2017-01-01

    The understanding of interacting dynamics is important for the characterization of real-world networks. In general, real-world networks are heterogeneous in the sense that each node of the network is a dynamics with different properties. For coupled nonidentical dynamics symmetric interactions are not straightforwardly defined from the coupling strength values. Thus, a challenging issue is whether we can define a symmetric interaction in this asymmetric setting. To address this problem we introduce the notion of the coupling impact. The coupling impact considers not only the coupling strength but also the energy of the individual dynamics, which is conveyed via the coupling. To illustrate this concept, we follow a data-driven approach by analyzing signals from pairs of coupled model dynamics using two different connectivity measures. We find that the coupling impact, but not the coupling strength, correctly detects a symmetric interaction between pairs of coupled dynamics regardless of their degree of asymmetry. Therefore, this approach allows us to reveal the real impact that one dynamics has on the other and hence to define symmetric interactions in pairs of nonidentical dynamics.

  2. Design of Multi-attribute Knowledge Base Based on Hybrid Knowledge Representation

    Institute of Scientific and Technical Information of China (English)

    TANG Zhi-jie; YANG Bao-an; ZHANG Ke-jing

    2006-01-01

    Based on the knowledge representation and knowledge reasoning, this paper addresses the creation of the multiattribute knowledge base on the basis of hybrid knowledge representation, with the help of object-oriented programming language and relational database. Compared with general knowledge base, multi-attribute knowledge base can enhance the ability of knowledge processing and application;integrate the heterogeneous knowledge, such as model,symbol, case-based sample knowledge; and support the whole decision process by integrated reasoning.

  3. Transfers in heterogeneous environments; Transferts en milieux heterogenes

    Energy Technology Data Exchange (ETDEWEB)

    Flesselles, J.M. [Saint-Gobain Recherche, 93 - Aubervilliers (France); Gouesbet, G.; Mees, L.; Roze, C.; Girasole, Th.; Grehan, G. [Laboratoire d' Electromagnetisme et Systemes Particulaires (LESP), UMR CNRS 6614, CORIA. Universite de Rouen et INSA de Rouen, 76 - Saint-Etienne du Rouvray (France); Goyheneche, J.M.; Vignoles, G.; Coindreau, O. [Laboratoire des Composites Thermostructuraux (LCTS), UMR 5801, 33 - Pessac (France); Moyne, Ch. [LEMTA (UMR 7563) CNRS-INPL-UHP, 54 - Vandoeuvre les Nancy (France); Coussy, O. [Institut Navier - ENPC, 77 - Marne-la-Vallee (France); Lassabatere, Th. [Electricite de France Les Renardieres, Dept. Materiaux Mecanique des Composants, 77 - Moret sur Loing (France); Tadrist, L. [IUSTI - UMR 6595, 13 - Marseille (France)

    2004-07-01

    This document gathers the articles and transparencies of the invited talks given at the 2004 French congress of thermal engineering about transfers in heterogeneous environment. Content: transfer phenomena in industrial glass furnaces; simple and multiple scattering diagnosis by femto-second pulsed laser: application to particulate diagnoses; thermal modeling of thermo-structural composites; hybrid mixtures theory, average volumic measurement, periodical or stochastic homogenization: advance in scale change processes; thermo-hydro-chemical-mechanical coupling in porous medium: application to young concrete structures and to clay barriers of disposal facilities; transfers and flows in fluidization: recent advances and future challenges. (J.S.)

  4. Effects of arrangement of heterogeneous neurons on frequency synchronization of a ring-coupled neuronal network%异质神经元的排列对环形耦合神经元网络频率同步的影响

    Institute of Scientific and Technical Information of China (English)

    孙晓娟; 杨白桦; 吴晔; 肖井华

    2014-01-01

    In this paper, we discuss the effects of heterogeneous neuron arrangement on the frequency synchronization of a ring-coupled FitzHugh-Nagumo neuronal network. The obtained numerical results reveal that the threshold of coupling strength for frequency synchronization may be different for different arrangements of the heterogeneous neurons on a ring. On average, the closer to each other the neurons which are less heterogeneous on a ring, the larger the critical coupling strength needed for neuronal network to achieve frequency synchronization is; the closer to each other the neurons which are more heterogeneous, the smaller the critical coupling strength needed for neuronal network to achieve frequency synchronization is. Furthermore, we give the underlined mechanism for this phenomenon by analyzing the process of frequency synchronization.%以一维环形耦合的非全同FitzHugh-Nagumo 神经元网络为研究对象,讨论这种异质神经元在环上的不同排列对其频率同步的影响。研究结果显示,异质神经元的排列不同,对应的神经元网络达到频率同步所需的临界耦合强度也不完全相同。在平均意义下,异质性较小的神经元在环上的距离越近,神经元网络达到频率同步所需的临界耦合强度越大;相反,异质性较大的神经元在环上的距离越近,神经元网络达到同步所需的临界耦合强度越小。通过对频率同步过程的分析,进一步给出了产生这一现象的动力学机理。

  5. Knowledge Heterogeneity and Team Creativity-The Moderating Roles of Creative Efficacy and Psychological Safety%知识异质性与团队创造力--创意效能感与心理安全感的调节作用

    Institute of Scientific and Technical Information of China (English)

    武朝艳; 王端旭; 洪雁

    2014-01-01

    文章基于信息多样化观点和社会认同理论对知识异质性影响团队创造力的不同解释,探讨了两种互补的团队共同信念--创意效能感和心理安全感对两者关系的调节作用。研究采用问卷调查方式,以194名企业员工为研究对象,采用层级回归的数据分析方法。结果发现:团队创意效能感调节知识异质性与团队创造力之间的关系;团队心理安全感也调节知识异质性与团队创造力之间的关系。%Based on different interpretations of the impact of knowledge heterogeneity on team creativity from both diversified in-formation viewpoint and social identity theory,the paper examines the moderating roles of team creative efficacy and team psy-chological safety, which are the two complementary team shared belief, on the relationship between knowledge heterogeneity and team creativity. The research applies the investigation method of questionnaire,collects data from 194 employees and uses the hierarchical regression data analysis method. The results show that both team creative efficacy and team psychological safety moderate the relationship between knowledge heterogeneity and team creativity.

  6. Modeling heterogeneous chemical processes on aerosol surface

    Institute of Scientific and Technical Information of China (English)

    Junjun Deng; Tijian Wang; Li Liu; Fei Jiang

    2010-01-01

    To explore the possible impact of heterogeneous chemical processes on atmospheric trace components,a coupled box model including gas-phase chemical processes,aerosol thermodynamic equilibrium processes,and heterogeneous chemical processes on the surface of dust,black carbon(BC)and sea salt is set up to simulate the effects of heterogeneous chemistry on the aerosol surface,and analyze the primary factors affecting the heterogeneous processes.Results indicate that heterogeneous chemical processes on the aerosol surface in the atmosphere will affect the concentrations of trace gases such as H2O2,HO2,O3,NO2,NO3,HNO3 and SO2,and aerosols such as SO42-,NO3-and NH4+.Sensitivity tests suggest that the magnitude of the impact of heterogeneous processes strongly depends on aerosol concentration and the surface uptake coefficients used in the box model.However,the impact of temperature on heterogeneous chemical processes is considerably less.The"renoxification"of HNO3 will affect the components of the troposphere such as nitrogen oxide and ozone.

  7. Sensitivity of the power distribution in large heterogeneous LMFBR designs

    Energy Technology Data Exchange (ETDEWEB)

    Tzanos, C.P.; Barthold, W.P.

    1977-01-01

    In heterogeneous LMFBR designs consisting of consecutive core and blanket zones, the power distribution is very sensitive to enrichment distribution changes in the core zones. The purpose of the paper is to analyze this sensitivity in heterogeneous LMFBR designs of different degrees of coupling among the core zones.

  8. Knowledge management

    OpenAIRE

    Jarošová, Milena

    2008-01-01

    Theoretical part: Basic terms of knowledge management, knowledge worker, knowledge creation and conversion process, prerequisites and benefits of knowledge management. Knowledge management and it's connection to organizational culture and structure, result measurements of knowledge management, learning organization and it's connection to knowledge management. Tacit knowledge management tools -- stories -- types, how to create, practical use, communities, coaching. Value Based Organization. Pr...

  9. 基于知识势差与耦合的产学研协同创新模型构建研究%Research of Model Building of I -U-R Collaborative Innovation on Knowledge Potential Difference and Knowledge Coupling

    Institute of Scientific and Technical Information of China (English)

    李永周; 贺海涛; 刘旸

    2014-01-01

    产学研协同创新是提升区域创新能力的重要途径。通过知识、技术等创新要素的共享与扩散,实现资源的互补与优化配置,产生创新的非线性效应。本文在阐述协同创新理论发展的基础上,分析产学研知识资源的特性,提出知识势差是知识转移的内生动力,知识耦合是知识创造的自然基础,构建以知识资源匹配、知识转移与创造、知识协同创新为主要阶段的过程模型。%Collaborative innovation of I-U-R is an important way to enhance regional innovation capability . Through innovative elements of sharing and diffusion such as knowledge and technology , it will achieve acomplementarity and optimal configuration of re-sources , then produce nonlinear effects of innovation . This paper is going to introduce the theory of collaborative innovation and reveal the characteristics of the knowledge resource . By this way , we put forward that knowledge potential difference is the inner motivation of knowl-edge transfer and knowledge coupling is the natural foundation of knowledge creation . As a result , we will build a process model to de-scribe the process of resource matching , transfer and creation , and collaborative innovation of knowledge .

  10. Magnetohydrodynamics on Heterogeneous architectures: a performance comparison

    CERN Document Server

    Pang, Bijia; Perrone, Michael

    2010-01-01

    We present magneto-hydrodynamic simulation results for heterogeneous systems. Heterogeneous architectures combine high floating point performance many-core units hosted in conventional server nodes. Examples include Graphics Processing Units (GPU's) and Cell. They have potentially large gains in performance, at modest power and monetary cost. We implemented a magneto-hydrodynamic (MHD) simulation code on a variety of heterogeneous and multi-core architectures --- multi-core x86, Cell, Nvidia and ATI GPU --- in different languages, FORTRAN, C, Cell, CUDA and OpenCL. We present initial performance results for these systems. To our knowledge, this is the widest comparison of heterogeneous systems for MHD simulations. We review the different challenges faced in each architecture, and potential bottlenecks. We conclude that substantial gains in performance over traditional systems are possible, and in particular that is possible to extract a greater percentage of peak theoretical performance from some systems when...

  11. The influence of fisher knowledge on the susceptibility of reef fish aggregations to fishing.

    Directory of Open Access Journals (Sweden)

    Jan Robinson

    Full Text Available Reef fishes that exhibit predictable aggregating behaviour are often considered vulnerable to overexploitation. However, fisher knowledge of this behaviour is often heterogeneous and, coupled with socioeconomic factors that constrain demand for or access to aggregated fish, will influence susceptibility to fishing. At two case study locations in Papua New Guinea, Ahus and Karkar islands, we conducted interview-based surveys to examine how local context influenced heterogeneity in knowledge of fish aggregations. We then explored the role of fisher knowledge in conferring susceptibility to fishing relative to socioeconomic drivers of fishing effort. Local heterogeneity in knowledge of aggregating behaviour differed between our case studies. At Ahus, variable access rights among fishers and genders to the main habitats were sources of heterogeneity in knowledge. By contrast, knowledge was more homogenous at Karkar and the sole source of variation was gear type. Differences between locations in the susceptibility of aggregations to fishing depended primarily on socioeconomic drivers of fishing effort rather than catchability. While Ahus fishers were knowledgeable of fish aggregations and used more selective gears, Karkar fishers were less constrained by tenure in their access to aggregation habitat. However, fishing effort was greater at Ahus and likely related to high dependency on fishing, greater access to provincial capital markets than Karkar and a weakening of customary management. Moreover, highly efficient fishing techniques have emerged at Ahus to exploit the non-reproductive aggregating behaviour of target species. Understanding how knowledge is structured within fishing communities and its relation to socioeconomic drivers of fishing effort is important if customary practices for conservation, such as tambu areas, are to be supported. The findings of this study call for a holistic approach to assessing the risks posed to reef fish

  12. The influence of fisher knowledge on the susceptibility of reef fish aggregations to fishing.

    Science.gov (United States)

    Robinson, Jan; Cinner, Joshua E; Graham, Nicholas A J

    2014-01-01

    Reef fishes that exhibit predictable aggregating behaviour are often considered vulnerable to overexploitation. However, fisher knowledge of this behaviour is often heterogeneous and, coupled with socioeconomic factors that constrain demand for or access to aggregated fish, will influence susceptibility to fishing. At two case study locations in Papua New Guinea, Ahus and Karkar islands, we conducted interview-based surveys to examine how local context influenced heterogeneity in knowledge of fish aggregations. We then explored the role of fisher knowledge in conferring susceptibility to fishing relative to socioeconomic drivers of fishing effort. Local heterogeneity in knowledge of aggregating behaviour differed between our case studies. At Ahus, variable access rights among fishers and genders to the main habitats were sources of heterogeneity in knowledge. By contrast, knowledge was more homogenous at Karkar and the sole source of variation was gear type. Differences between locations in the susceptibility of aggregations to fishing depended primarily on socioeconomic drivers of fishing effort rather than catchability. While Ahus fishers were knowledgeable of fish aggregations and used more selective gears, Karkar fishers were less constrained by tenure in their access to aggregation habitat. However, fishing effort was greater at Ahus and likely related to high dependency on fishing, greater access to provincial capital markets than Karkar and a weakening of customary management. Moreover, highly efficient fishing techniques have emerged at Ahus to exploit the non-reproductive aggregating behaviour of target species. Understanding how knowledge is structured within fishing communities and its relation to socioeconomic drivers of fishing effort is important if customary practices for conservation, such as tambu areas, are to be supported. The findings of this study call for a holistic approach to assessing the risks posed to reef fish aggregations by fishing

  13. Landscape evaluation of heterogeneous areas using fuzzy sets

    Directory of Open Access Journals (Sweden)

    Ralf-Uwe Syrbe

    1998-02-01

    Full Text Available Landscape evaluation is an interesting field for fuzzy approaches, because it happens on the transition line between natural and social systems. Both are very complex. Therefore, transformation of scientific results to politically significant statements on environmental problems demands intelligent support. Particularly landscape planners need methods to gather natural facts of an area and assess them in consideration of its meaning to society as a whole. Since each land unit is heterogeneous, a special methodology is necessary. Such an evaluation technique was developed within a Geographical Information System (ARC/INFO. The methodology combines several known methods with fuzzy approaches to catch the intrinsic fuzziness of ecological systems as well as the heterogeneity of landscape. Additionally, a way will be discussed to vary the fuzzy inference in order to consider spatial relations of various landscape elements. Fuzzy logic is used to process the data uncertainty, to simulate the vagueness of knowledge about ecological functionality, and to model the spatial structure of landscape. Fuzzy sets describe the attributes of thematically defined land units and their assessment results. In this way, the available information will be preserved in their full diversity. The fuzzy operations are executed by AML-programs (ARC/INFO Macro Language. With such a tight coupling, it is possible to use the geographical functions (neighbourhoods, distances, etc. of GIS within the fuzzy system directly.

  14. Reconstruction of moving acoustic sources in heterogeneous elastic solid

    Science.gov (United States)

    Lloyd, Stephen F.; Jeong, Chanseok

    2016-04-01

    A novel computational framework for reconstructing spatial and temporal profiles of moving acoustic sources from wave responses measured at sparsely distributes sensors is introduced in this paper. This method can be applied to a broad range of acoustic-source inversion (ASI) problems for heterogeneous, complex-shaped coupled dynamic systems. The finite element method (FEM) is used to obtain wave response solutions due guessed moving sources. An adjoint-gradient based optimization technique iteratively improves the guesses so that the guessed moving sources converge on the actual moving sources. To reconstruct acoustic source profiles without a-priori knowledge of sources, we will employ high-resolution discretization of source functions in space and time. Because of such dense discretization, the order of magnitude of number of inversion parameters could range from millions to billions. Numerical experiments prove the robustness of this method by reconstructing spatial and temporal profiles of multiple dynamic moving body forces in a one-dimensional heterogeneous solid bar. The sources create stress waves propagating through the bar. The guessed source functions are spatially discretized by using linear shape functions with an element size of 1m at discrete times with a time step of 0.001s. Thus, the total number of control parameters in this example is 100,000 (i.e., 100 (in space) by 1000 (in time)). The convergence toward the target in the numerical examples is excellent, reconstructing the spatial and temporal footprints of the sources.

  15. Heterogeneous network architectures

    DEFF Research Database (Denmark)

    Christiansen, Henrik Lehrmann

    2006-01-01

    Future networks will be heterogeneous! Due to the sheer size of networks (e.g., the Internet) upgrades cannot be instantaneous and thus heterogeneity appears. This means that instead of trying to find the olution, networks hould be designed as being heterogeneous. One of the key equirements here...... is flexibility. This thesis investigates such heterogeneous network architectures and how to make them flexible. A survey of algorithms for network design is presented, and it is described how using heuristics can increase the speed. A hierarchical, MPLS based network architecture is described...... and it is discussed that it is advantageous to heterogeneous networks and illustrated by a number of examples. Modeling and simulation is a well-known way of doing performance evaluation. An approach to event-driven simulation of communication networks is presented and mixed complexity modeling, which can simplify...

  16. Staff Knowledge Absorption of Business Model Innovation Effect--With Employee Social Network Heterogeneity for Regulating Variable%员工知识吸收对商业模式创新的影响--以员工的社会网络异质性为调节变量

    Institute of Scientific and Technical Information of China (English)

    丁浩; 王炳成

    2013-01-01

      商业模式创新将会是未来企业获取竞争优势的重要手段,但驱动商业模式创新的因素却很少被研究.本文运用结构方程模型,探讨了员工知识吸收对商业模式创新的影响,及员工的社会网络异质性在员工知识吸收与商业模式创新的关系中的调节作用.研究过程中,采用利克特五点量表对员工知识吸收和商业模式创新进行测量,运用自我中心网络对员工的社会网络异质性进行了测量.在108有效问卷的基础上,运用AMOS7.0软件,检验了相关的假设.研究结果表明,员工知识吸收对商业模式创新的影响达到显著水平,员工社会网络异质性对商业模式创新的作用未达到显著水平,但员工社会网络异质性会在员工知识吸收与商业模式创新关系中起到调节作用.最后,论文给出了相关的建议.%Business model innovation will be an important means for the future enterprises to gain competitive advantage, but the factors driving business model innovation have rarely been studied. This paper uses the method of structural equation model to explore the direct effect of employees' knowledge absorptive capacity on business model innovation, and the moderating effects of employees' social network heterogeneity between employees' knowledge absorptive capacity and business model innovation. In the process of this study, we use Likert five-point scale to measure employees' knowledge absorptive capacity and business model innovation, and use ego-centered network to measure employees' social network heterogeneity. Based on 108 valid questionnaires, we uses AMOS7.0 to test the hypothesis. The result shows, employees' knowledge absorption capacity will significantly affect business model innovation, while employees' social network heterogeneity has limited direct influence on business model innovation, but employees' social network heterogeneity has significant moderate effect on the

  17. Heterogeneous cellular networks

    CERN Document Server

    Hu, Rose Qingyang

    2013-01-01

    A timely publication providing coverage of radio resource management, mobility management and standardization in heterogeneous cellular networks The topic of heterogeneous cellular networks has gained momentum in industry and the research community, attracting the attention of standardization bodies such as 3GPP LTE and IEEE 802.16j, whose objectives are looking into increasing the capacity and coverage of the cellular networks. This book focuses on recent progresses,  covering the related topics including scenarios of heterogeneous network deployment, interference management i

  18. Teaching Heterogeneous Classes.

    Science.gov (United States)

    Millrood, Radislav

    2002-01-01

    Discusses an approach to teaching heterogeneous English-as-a-Second/Foreign-Language classes. Draws on classroom research data to describe the features of a success-building lesson context. (Author/VWL)

  19. Survey on preconception health care knowledge and attitude among newly married couples in a district of Shanghai%上海某区新婚夫妇孕前保健相关知识和态度调查

    Institute of Scientific and Technical Information of China (English)

    汤振宇; 陆亦琼; 许薇

    2015-01-01

    目的:了解上海市新婚夫妇的孕前保健态度及其知识水平。方法采用问卷调查的方法,了解1025名新婚夫妇对孕前保健的知晓和态度情况,以及对应孕前保健知识的水平。结果在受访对象中98.5%有兴趣接受孕前保健服务,真正了解免费孕前保健服务者占61.8%。受访者的67.8%愿意为孕前保健服务支付500元以下的费用,最受欢迎的获取知识的来源是妇产科医生,占受访者的56.1%。在孕前保健知识方面,男女之间知识水平得分比较差异有统计学意义(t=5.385,P<0.05)。不同年龄组、不同文化程度、不同收入之间受访者保健知识得分比较差异均有统计学意义( F值分别为3.108、3.878、8.346,均P<0.05),而不同职业之间比较差异无统计学意义(P>0.05)。结论目前孕前保健的接受度较高,但孕前保健优生知识不全面,可以根据不同对象提供个性化的服务和全面的优生知识,从而提高孕前保健服务效率。%Objective To investigate the preconception health care attitude and knowledge level of newly married couples in Shanghai. Methods Questionnaire survey was conducted among 1 025 couples on preconception health care awareness and attitudes as well as the corresponding preconception health knowledge.Results Among respondents 98.5% had interest in accepting preconception health care services, and 61.8%truly understood the free preconception care services.There were 67.8%of the respondents willing to pay less than 500 Yuan for preconception health care services.The most popular source of preconception knowledge was obstetrician, occupying 56.1%. The knowledge of male and female in preconception health care was significantly different (t=5.385,P0.05).Conclusion The acceptance of preconception health care is relatively high at present, but the existing preconception care knowledge is insufficient

  20. Impact of Aquifer Heterogeneities on Autotrophic Denitrification.

    Science.gov (United States)

    McCarthy, A.; Roques, C.; Selker, J. S.; Istok, J. D.; Pett-Ridge, J. C.

    2015-12-01

    Nitrate contamination in groundwater is a big challenge that will need to be addressed by hydrogeologists throughout the world. With a drinking water standard of 10mg/L of NO3-, innovative techniques will need to be pursued to ensure a decrease in drinking water nitrate concentration. At the pumping site scale, the influence and relationship between heterogeneous flow, mixing, and reactivity is not well understood. The purpose of this project is to incorporate both physical and chemical modeling techniques to better understand the effect of aquifer heterogeneities on autotrophic denitrification. We will investigate the link between heterogeneous hydraulic properties, transport, and the rate of autotrophic denitrification. Data collected in previous studies in laboratory experiments and pumping site scale experiments will be used to validate the models. The ultimate objective of this project is to develop a model in which such coupled processes are better understood resulting in best management practices of groundwater.

  1. Seismoelectric effects due to mesoscopic heterogeneities

    CERN Document Server

    Jougnot, D; Carbajal, M Rosas; Linde, N; Holliger, K

    2014-01-01

    While the seismic effects of wave-induced fluid flow due to mesoscopic heterogeneities have been studied for several decades, the role played by these types of heterogeneities on seismoelectric phenomena is largely unexplored. To address this issue, we have developed a novel methodological framework which allows for the coupling of wave-induced fluid flow, as inferred through numerical oscillatory compressibility tests, with the pertinent seismoelectric conversion mechanisms. Simulating the corresponding response of a water-saturated sandstone sample containing mesoscopic fractures, we demonstrate for the first time that these kinds of heterogeneities can produce measurable seismoelectric signals under typical laboratory conditions. Given that this phenomenon is sensitive to key hydraulic and mechanical properties, we expect that the results of this pilot study will stimulate further exploration on this topic in several domains of the Earth, environmental, and engineering sciences.

  2. Application of an Online-Coupled Regional Climate Model, WRF-CAM5, over East Asia for Examination of Ice Nucleation Schemes: Part II. Sensitivity to Heterogeneous Ice Nucleation Parameterizations and Dust Emissions

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yang; Chen, Ying; Fan, Jiwen; Leung, Lai-Yung

    2015-09-01

    Aerosol particles can affect cloud microphysical properties by serving as ice nuclei (IN). Large uncertainties exist in the ice nucleation parameterizations (INPs) used in current climate models. In this Part II paper, to examine the sensitivity of the model predictions to different heterogeneous INPs, WRF-CAM5 simulation using the INP of Niemand et al. (N12) [1] is conducted over East Asia for two full years, 2006 and 2011, and compared with simulation using the INP of Meyers et al. (M92) [2], which is the original INP used in CAM5. M92 calculates the nucleated ice particle concentration as a function of ice supersaturation, while N12 represents the nucleated ice particle concentration as a function of temperature and the number concentrations and surface areas of dust particles. Compared to M92, the WRF-CAM5 simulation with N12 produces significantly higher nucleated ice crystal number concentrations (ICNCs) in the northern domain where dust sources are located, leading to significantly higher cloud ice number and mass concentrations and ice water path, but the opposite is true in the southern domain where temperatures and moistures play a more important role in ice formation. Overall, the simulation with N12 gives lower downward shortwave radiation but higher downward longwave radiation, cloud liquid water path, cloud droplet number concentrations, and cloud optical depth. The increase in cloud optical depth and the decrease in downward solar flux result in a stronger shortwave and longwave cloud forcing, and decreases temperature at 2-m and precipitation. Changes in temperature and radiation lower surface concentrations of OH, O3, SO42-, and PM2.5, but increase surface concentrations of CO, NO2, and SO2 over most of the domain. By acting as cloud condensation nuclei (CCN) and IN, dust particles have different impacts on cloud water and ice number concentrations, radiation, and temperature at 2-m and

  3. Coupled transfers; Transferts couples

    Energy Technology Data Exchange (ETDEWEB)

    Nicolas, X.; Lauriat, G.; Jimenez-Rondan, J. [Universite de Marne-la-Vallee, Lab. d' Etudes des Transferts d' Energie et de Matiere (LETEM), 77 (France); Bouali, H.; Mezrhab, A. [Faculte des Sciences, Dept. de Physique, Lab. de Mecanique et Energetique, Oujda (Morocco); Abid, C. [Ecole Polytechnique Universitaire de Marseille, IUSTI UMR 6595, 13 Marseille (France); Stoian, M.; Rebay, M.; Lachi, M.; Padet, J. [Faculte des Sciences, Lab. de Thermomecanique, UTAP, 51 - Reims (France); Mladin, E.C. [Universitaire Polytechnique Bucarest, Faculte de Genie Mecanique, Bucarest (Romania); Mezrhab, A. [Faculte des Sciences, Lab. de Mecanique et Energetique, Dept. de Physique, Oujda (Morocco); Abid, C.; Papini, F. [Ecole Polytechnique, IUSTI, 13 - Marseille (France); Lorrette, C.; Goyheneche, J.M.; Boechat, C.; Pailler, R. [Laboratoire des Composites ThermoStructuraux, UMR 5801, 33 - Pessac (France); Ben Salah, M.; Askri, F.; Jemni, A.; Ben Nasrallah, S. [Ecole Nationale d' Ingenieurs de Monastir, Lab. d' Etudes des Systemes Thermiques et Energetiques (Tunisia); Grine, A.; Desmons, J.Y.; Harmand, S. [Laboratoire de Mecanique et d' Energetique, 59 - Valenciennes (France); Radenac, E.; Gressier, J.; Millan, P. [ONERA, 31 - Toulouse (France); Giovannini, A. [Institut de Mecanique des Fluides de Toulouse, 31 (France)

    2005-07-01

    This session about coupled transfers gathers 30 articles dealing with: numerical study of coupled heat transfers inside an alveolar wall; natural convection/radiant heat transfer coupling inside a plugged and ventilated chimney; finite-volume modeling of the convection-conduction coupling in non-stationary regime; numerical study of the natural convection/radiant heat transfer coupling inside a partitioned cavity; modeling of the thermal conductivity of textile reinforced composites: finite element homogenization on a full periodical pattern; application of the control volume method based on non-structured finite elements to the problems of axisymmetrical radiant heat transfers in any geometries; modeling of convective transfers in transient regime on a flat plate; a conservative method for the non-stationary coupling of aero-thermal engineering codes; measurement of coupled heat transfers (forced convection/radiant transfer) inside an horizontal duct; numerical simulation of the combustion of a water-oil emulsion droplet; numerical simulation study of heat and mass transfers inside a reactor for nano-powders synthesis; reduction of a combustion and heat transfer model of a direct injection diesel engine; modeling of heat transfers inside a knocking operated spark ignition engine; heat loss inside an internal combustion engine, thermodynamical and flamelet model, composition effects of CH{sub 4}H{sub 2} mixtures; experimental study and modeling of the evolution of a flame on a solid fuel; heat transfer for laminar subsonic jet of oxygen plasma impacting an obstacle; hydrogen transport through a A-Si:H layer submitted to an hydrogen plasma: temperature effects; thermal modeling of the CO{sub 2} laser welding of a magnesium alloy; radiant heat transfer inside a 3-D environment: application of the finite volume method in association with the CK model; optimization of the infrared baking of two types of powder paints; optimization of the emission power of an infrared

  4. Knowledge Sharing is Knowledge Creation

    DEFF Research Database (Denmark)

    Greve, Linda

    2015-01-01

    Knowledge sharing and knowledge transfer are important to knowledge communication. However when groups of knowledge workers engage in knowledge communication activities, it easily turns into mere mechanical information processing despite other ambitions. This article relates literature of knowledge...... reducing complexity and dividing knowledge into to dichotomies or hierarchies, knowledge workers should be enabled to use different strategies for knowledge sharing, -transfer and –creation depending on the task and the nature of the knowledge. However if the ambition is to have a strategy for sharing...

  5. Green heterogeneous wireless networks

    CERN Document Server

    Ismail, Muhammad; Nee, Hans-Peter; Qaraqe, Khalid A; Serpedin, Erchin

    2016-01-01

    This book focuses on the emerging research topic "green (energy efficient) wireless networks" which has drawn huge attention recently from both academia and industry. This topic is highly motivated due to important environmental, financial, and quality-of-experience (QoE) considerations. Specifically, the high energy consumption of the wireless networks manifests in approximately 2% of all CO2 emissions worldwide. This book presents the authors’ visions and solutions for deployment of energy efficient (green) heterogeneous wireless communication networks. The book consists of three major parts. The first part provides an introduction to the "green networks" concept, the second part targets the green multi-homing resource allocation problem, and the third chapter presents a novel deployment of device-to-device (D2D) communications and its successful integration in Heterogeneous Networks (HetNets). The book is novel in that it specifically targets green networking in a heterogeneous wireless medium, which re...

  6. Isotopes in heterogeneous catalysis

    CERN Document Server

    Hargreaves, Justin SJ

    2006-01-01

    The purpose of this book is to review the current, state-of-the-art application of isotopic methods to the field of heterogeneous catalysis. Isotopic studies are arguably the ultimate technique in in situ methods for heterogeneous catalysis. In this review volume, chapters have been contributed by experts in the field and the coverage includes both the application of specific isotopes - Deuterium, Tritium, Carbon-14, Sulfur-35 and Oxygen-18 - as well as isotopic techniques - determination of surface mobility, steady state transient isotope kinetic analysis, and positron emission profiling.

  7. Heterogeneity of the intrahepatic biliary epithelium

    Institute of Scientific and Technical Information of China (English)

    Shannon Glaser; Heather Francis; Sharon DeMorrow; Gene LeSage; Giammarco Fava; Marco Marzioni; Julie Venter; Gianfranco Alpini

    2006-01-01

    The objectives of this review are to outline the recent findings related to the morphological heterogeneity of the biliary epithelium and the heterogeneous pathophysiological responses of different sized bile ducts to liver gastrointestinal hormones and peptides and liver injury/toxins with changes in apoptotic, proliferative and secretory activities. The knowledge of biliary function is rapidly increasing because of the recognition that biliary epithelial cells (cholangiocytes) are the targets of human cholangiopathies, which are characterized by proliferation/damage of bile ducts within a small range of sizes. The unique anatomy, morphology, innervation and vascularization of the biliary epithelium are consistent with function of cholangiocytes within different regions of the biliary tree. The in vivo models [e.g., bile duct ligation (BDL), partial hepatectomy, feeding of bile acids,carbon tetrachloride (CCl4) or α-naphthylisothiocyanate (ANIT)] and the in vivo experimental tools [e.g., freshly isolated small and large cholangiocytes or intrahepatic bile duct units (IBDU) and primary cultures of small and large murine cholangiocytes] have allowed us to demonstrate the morphological and functional heterogeneity of the intrahepatic biliary epithelium.These models demonstrated the differential secretory activities and the heterogeneous apoptotic and proliferative responses of different sized ducts. Similar to animal models of cholangiocyte proliferation/injury restricted to specific sized ducts, in human liver diseases bile duct damage predominates specific sized bile ducts.Future studies related to the functional heterogeneity of the intrahepatic biliary epithelium may disclose new pathophysiological treatments for patients with cholangiopathies.

  8. Innovation through Knowledge Transfer 2012

    CERN Document Server

    Gabrys, Bogdan; Musial-Gabrys, Katarzyna; Roach, Jim; Innovation through Knowledge Transfer InnovationKT-2012

    2013-01-01

    Across the world there is growing awareness of the importance of innovation and knowledge transfer.  Innovation in the sense of generating new knowledge and making better use of existing knowledge, coupled with knowledge transfer and sharing paradigms, have never been more relevant to the universities, industry, commerce and the third sector.  This volume represents the proceedings of the Innovation through Knowledge Transfer 2012 Conference which formed an excellent opportunity to disseminate, share and discuss the impact of innovation, knowledge sharing, enterprise and entrepreneurship.  The volume contains papers presented at a Workshop on ‘The Meta Transfer of Knowledge: Challenges in the Transfer of Knowledge in Industry’, others from thematic sessions on ‘Next-Practice in University Based Open Innovation’,  ‘Social Innovation and Related Paradigms’, ‘Engagement with Industry and Commerce’ and ‘Knowledge Exchange’.  All papers were thoroughly reviewed by referees knowledgeable in...

  9. KNOWLEDGE TRANSFER THROUGH NETWORKS

    Directory of Open Access Journals (Sweden)

    GYÖRGY ATTILA

    2012-06-01

    Full Text Available Knowledge is a vital intangible asset for any organization and cannot be valued exactly due its special form of materialization. Although we have this drawback, a scientifically established value should be used in order to measure the performance of knowledge holders. A correct valuation helps to know the worth of assets offered in exploitation. Exploitation of this resource could be done in several different ways, but integration in knowledge networks seems to generate best efficiency ratio. Networks offer the possibility to change information, to obtain new information, to build further ideas arose from network partners or to develop together new ideas. Thus, networks assure conditions to optimize the members’ knowledge portfolios. Optimization of knowledge usage creates benefits for network members. These benefits could be profits (if members are private companies or social welfare (if members are looking after collective purposes. Taxonomy of knowledge networks is diverse, permitting an adaptation to the needs of members. Networks permit a large scale of heterogeneity. Since an important part of new knowledge creating costs is covered from public budgetary resources, a special development is recorded at those networks which are exclusively or partly organized in the public sector or benefit by participation from the public sector.

  10. Heterogeneous Uncertainty Management

    Science.gov (United States)

    2008-03-08

    probabilistic ( HTP ) agents, the concept of probabilistic version of XML and RDF, and probabilistic methods to reason about collections of moving objects. S...heterogeneous temporal probabilistic ( HTP ) agents, the concept of probabilistic version of XML and RDF, and probabilistic methods to reason about...temporal probabilistic ( HTP ) agent. HTP agents can build temporal probabilistic reasoning capabilities on top of multiple databases and software

  11. Heterogeneous Computing in Economics

    DEFF Research Database (Denmark)

    Dziubinski, M.P.; Grassi, S.

    2014-01-01

    This paper shows the potential of heterogeneous computing in solving dynamic equilibrium models in economics. We illustrate the power and simplicity of C++ Accelerated Massive Parallelism (C++ AMP) recently introduced by Microsoft. Starting from the same exercise as Aldrich et al. (J Econ Dyn...

  12. Heterogeneity of Intellectual Assets

    DEFF Research Database (Denmark)

    Dahlgren, Johan Henrich; Lund Jensen, Rasmus; Valentin, Finn

    2004-01-01

    This paper deals with methodological issues of assessing the composition and level ofheterogeneity of firms' intellectual assets. It develops an original metric - referred to asthe H-index - for measuring heterogeneity using data extracted from patent documents.The main purpose is to improve...

  13. Heterogeneous chromium catalysts

    NARCIS (Netherlands)

    2005-01-01

    The present invention relates to a heterogeneous chromium catalyst system for the polymerisation of ethylene and/or alpha olefins prepared by the steps of: (a) providing a silica-containing support, (b) treating the silica-containing support with a chromium compound to form a chromium-based silica-c

  14. Information and Heterogeneous Beliefs

    DEFF Research Database (Denmark)

    Christensen, Peter Ove; Qin, Zhenjiang

    2014-01-01

    In an incomplete market with heterogeneous prior beliefs, we show public information can have a substantial impact on the ex ante cost of capital, trading volume, and investor welfare. The Pareto effcient public information system is the system enjoying the maximum ex ante cost of capital and the...

  15. Heterogeneity of Dutch rainfall

    NARCIS (Netherlands)

    Witter, J.V.

    1984-01-01

    Rainfall data for the Netherlands have been used in this study to investigate aspects of heterogeneity of rainfall, in particular local differences in rainfall levels, time trends in rainfall, and local differences in rainfall trend. The possible effect of urbanization and industrialization on the

  16. Receiver Heterogeneity Helps

    DEFF Research Database (Denmark)

    Kovács, Erika R.; Pedersen, Morten Videbæk; Roetter, Daniel Enrique Lucani;

    2014-01-01

    Heterogeneity amongst devices and desired service are commonly seen as a source of additional challenges for setting up an efficient multi-layer multicast service. In particular, devices requiring only the base layer can become a key bottleneck to the performance for other devices. This paper...

  17. "Tacit Knowledge" versus "Explicit Knowledge"

    DEFF Research Database (Denmark)

    Sanchez, Ron

    2004-01-01

    This paper explains two fundamental approaches to knowledge management. The tacitknowledge approach emphasizes understanding the kinds of knowledge that individualsin an organization have, moving people to transfer knowledge within an organization,and managing key individuals as knowledge creators...... and carriers. By contrast, theexplicit knowledge approach emphasizes processes for articulating knowledge held byindividuals, the design of organizational approaches for creating new knowledge, andthe development of systems (including information systems) to disseminate articulatedknowledge within...... an organization. The relative advantages and disadvantages of bothapproaches to knowledge management are summarized. A synthesis of tacit andknowledge management approaches is recommended to create a hybrid design for theknowledge management practices in a given organization....

  18. Knowledge Management

    CERN Document Server

    Gerami, Mohsen

    2010-01-01

    This paper discusses the important process of knowledge and its management, and differences between tacit and explicit knowledge and understanding the culture as a key issue for the successful implementation of knowledge management, in addition to, this paper is concerned with the four-stage model for the evolution of information technology (IT) support for knowledge management in law firms.

  19. Screening of heterogeneous surfaces: charge renormalization of Janus particles.

    Science.gov (United States)

    Boon, N; Carvajal Gallardo, E; Zheng, S; Eggen, E; Dijkstra, M; van Roij, R

    2010-03-17

    Nonlinear ionic screening theory for heterogeneously charged spheres is developed in terms of a mode decomposition of the surface charge. A far-field analysis of the resulting electrostatic potential leads to a natural generalization of charge renormalization from purely monopolar to dipolar, quadrupolar, etc, including 'mode couplings'. Our novel scheme is generally applicable to large classes of surface heterogeneities, and is explicitly applied here to Janus spheres with differently charged upper and lower hemispheres, revealing strong renormalization effects for all multipoles.

  20. Communications Solutions for Heterogeneous Systems Based on SOA

    Science.gov (United States)

    Wei, Xianmin

    In order to address the gaps which widely used in business application architecture and problems of heterogeneous system communication, this paper provides a standardized framework of SOA, built in the application of a loose coupling between systems "server + proxy" data exchange platform, to achieve heterogeneous data exchange and data sharing, and developed a business based on Web services platform, making full use of the Web service, which makes the system has good scalability and maintainability, to solve the problem of heterogeneous system communication and widely used to make up for the current architecture lack of business applications.

  1. Transfer Printed Nanomembranes for Heterogeneously Integrated Membrane Photonics

    Directory of Open Access Journals (Sweden)

    Hongjun Yang

    2015-11-01

    Full Text Available Heterogeneous crystalline semiconductor nanomembrane (NM integration is investigated for single-layer and double-layer Silicon (Si NM photonics, III-V/Si NM lasers, and graphene/Si NM total absorption devices. Both homogeneous and heterogeneous integration are realized by the versatile transfer printing technique. The performance of these integrated membrane devices shows, not only intact optical and electrical characteristics as their bulk counterparts, but also the unique light and matter interactions, such as Fano resonance, slow light, and critical coupling in photonic crystal cavities. Such a heterogeneous integration approach offers tremendous practical application potentials on unconventional, Si CMOS compatible, and high performance optoelectronic systems.

  2. Unsupervised Spectral Mesh Segmentation Driven by Heterogeneous Graphs.

    Science.gov (United States)

    Theologou, Panagiotis; Pratikakis, Ioannis; Theoharis, Theoharis

    2017-02-01

    A fully automatic mesh segmentation scheme using heterogeneous graphs is presented. We introduce a spectral framework where local geometry affinities are coupled with surface patch affinities. A heterogeneous graph is constructed combining two distinct graphs: a weighted graph based on adjacency of patches of an initial over-segmentation, and the weighted dual mesh graph. The partitioning relies on processing each eigenvector of the heterogeneous graph Laplacian individually, taking into account the nodal set and nodal domain theory. Experiments on standard datasets show that the proposed unsupervised approach outperforms the state-of-the-art unsupervised methodologies and is comparable to the best supervised approaches.

  3. Coupled lasers: phase versus chaos synchronization.

    Science.gov (United States)

    Reidler, I; Nixon, M; Aviad, Y; Guberman, S; Friesem, A A; Rosenbluh, M; Davidson, N; Kanter, I

    2013-10-15

    The synchronization of chaotic lasers and the optical phase synchronization of light originating in multiple coupled lasers have both been extensively studied. However, the interplay between these two phenomena, especially at the network level, is unexplored. Here, we experimentally compare these phenomena by controlling the heterogeneity of the coupling delay times of two lasers. While chaotic lasers exhibit deterioration in synchronization as the time delay heterogeneity increases, phase synchronization is found to be independent of heterogeneity. The experimental results are found to be in agreement with numerical simulations for semiconductor lasers.

  4. Knowledge Sharing

    DEFF Research Database (Denmark)

    Holdt Christensen, Peter

    The concept of knowledge management has, indeed, become a buzzword that every single organization is expected to practice and live by. Knowledge management is about managing the organization's knowledge for the common good of the organization -but practicing knowledge management is not as simple...... as that. This article focuses on knowledge sharing as the process seeking to reduce the resources spent on reinventing the wheel.The article introduces the concept of time sensitiveness; i.e. that knowledge is either urgently needed, or not that urgently needed. Furthermore, knowledge sharing...... is considered as either a push or pull system. Four strategies for sharing knowledge - help, post-it, manuals and meeting, and advice are introduced. Each strategy requires different channels for sharing knowledge. An empirical analysis in a production facility highlights how the strategies can be practiced....

  5. Knowledge Technologies

    CERN Document Server

    Milton, Nick

    2008-01-01

    Several technologies are emerging that provide new ways to capture, store, present and use knowledge. This book is the first to provide a comprehensive introduction to five of the most important of these technologies: Knowledge Engineering, Knowledge Based Engineering, Knowledge Webs, Ontologies and Semantic Webs. For each of these, answers are given to a number of key questions (What is it? How does it operate? How is a system developed? What can it be used for? What tools are available? What are the main issues?). The book is aimed at students, researchers and practitioners interested in Knowledge Management, Artificial Intelligence, Design Engineering and Web Technologies. During the 1990s, Nick worked at the University of Nottingham on the application of AI techniques to knowledge management and on various knowledge acquisition projects to develop expert systems for military applications. In 1999, he joined Epistemics where he worked on numerous knowledge projects and helped establish knowledge management...

  6. A Probabilistic Approach to Knowledge Translation

    OpenAIRE

    Jiang, Shangpu; Lowd, Daniel; Dou, Dejing

    2015-01-01

    In this paper, we focus on a novel knowledge reuse scenario where the knowledge in the source schema needs to be translated to a semantically heterogeneous target schema. We refer to this task as "knowledge translation" (KT). Unlike data translation and transfer learning, KT does not require any data from the source or target schema. We adopt a probabilistic approach to KT by representing the knowledge in the source schema, the mapping between the source and target schemas, and the resulting ...

  7. Heterogeneous Voter Models

    CERN Document Server

    Masuda, Naoki; Redner, S

    2010-01-01

    We introduce the heterogeneous voter model (HVM), in which each agent has its own intrinsic rate to change state, reflective of the heterogeneity of real people, and the partisan voter model (PVM), in which each agent has an innate and fixed preference for one of two possible opinion states. For the HVM, the time until consensus is reached is much longer than in the classic voter model. For the PVM in the mean-field limit, a population evolves to a "selfish" state, where each agent tends to be aligned with its internal preference. For finite populations, discrete fluctuations ultimately lead to consensus being reached in a time that scales exponentially with population size.

  8. Information and Heterogeneous Beliefs

    DEFF Research Database (Denmark)

    Christensen, Peter Ove; Qin, Zhenjiang

    2014-01-01

    In an incomplete market with heterogeneous prior beliefs, we show public information can have a substantial impact on the ex ante cost of capital, trading volume, and investor welfare. The Pareto effcient public information system is the system enjoying the maximum ex ante cost of capital...... ante risk premium is unaffected by the informativeness of the public information system. Similar results are obtained in a production economy, but the impact on the ex ante cost of capital is dampened compared to the exchange economy due to welfare improving reductions in real investments to smooth...... and the maximum expected abnormal trading volume. Imperfect public information increases the gains-to-trade based on heterogeneously updated posterior beliefs. In an exchange economy, this leads to higher growth in the investors' certainty equivalents and, thus, a higher equilibrium interest rate, whereas the ex...

  9. Role of Knowledge Based Communities in Knowledge Process

    Directory of Open Access Journals (Sweden)

    Sebastian Ion CEPTUREANU

    2015-12-01

    Full Text Available In the new economy, knowledge is an essential component of economic and social systems. The organizational focus has to be on building knowledge-based management, development of human resource and building intellectual capital capabilities. Knowledge-based management is defined, at company level, by economic processes that emphasize creation, selling, buying, learning, storing, developing, sharing and protection of knowledge as a decisive condition for profit and long-term sustainability of the company. Hence, knowledge is, concurently, according to a majoritiy of specialists, raw material, capital, product and an essential input. Knowledge-based communities are one of the main constituent elements of a framework for knowledge based management. These are peer networks consisting of practitioners within an organization, supporting each other to perform better through the exchange and sharing of knowledge. Some large companies have contributed or supported the establishment of numerous communities of practice, some of which may have several thousand members. They operate in different ways, are of different sizes, have different areas of interest and addresses knowledge at different levels of its maturity. This article examines the role of knowledge-based communities from the perspective of knowledge based management, given that the arrangements for organizational learning, creating, sharing, use of knowledge within organizations become more heterogeneous and take forms more difficult to predict by managers and specialists.

  10. Micromechanics of heterogeneous materials

    CERN Document Server

    Buryachenko, Valeriy

    2007-01-01

    Here is an accurate and timely account of micromechanics, which spans materials science, mechanical engineering, applied mathematics, technical physics, geophysics, and biology. The book features rigorous and unified theoretical methods of applied mathematics and statistical physics in the material science of microheterogeneous media. Uniquely, it offers a useful demonstration of the systematic and fundamental research of the microstructure of the wide class of heterogeneous materials of natural and synthetic nature.

  11. Electrokinetics of heterogeneous interfaces.

    Science.gov (United States)

    Zembala, Maria

    2004-12-31

    The influence of surface heterogeneity of various types on electrokinetic parameters is reviewed. The scope of the paper covers classical electrokinetic phenomena characterized by linear dependence of electrokinetic parameters vs. related driving forces. Neither non-linear effects nor the effects of non-equilibrium electric double layer are considered. A historical description of hydrodynamic aspect of electrokinetic phenomena exploiting the slip plane idea is briefly outlined. Attempts to estimate the slip plane location by comparing the diffuse layer and zeta potential values for some model systems are presented. The surface heterogeneity was divided into three categories. Heterogeneity of the first type was related to geometrical morphology of an interfacial region characterized by a considerable surface development producing a three-dimensional interfacial region. The effects of solid roughness, hairy surface, dense polymer layers and gel-like layers are discussed here. The very high surface conductivity detected for such interfaces seems to be a good indicator of the presence of structured layers of this type. Heterogeneous interfaces of the second class cover systems exhibiting non-uniform distribution of surface charge. The non-uniform surface charge distribution can be either of a molecular (discrete charges) or of a microscale (two-dimensional micropatches or three-dimensional structures formed by polyelectrolyte multilayers). The last class of systems examined includes interfaces composed of charged substrate covered by charged bulky objects (particles). In comparison to the homogeneous surfaces, adsorbed charged particles modify both hydrodynamic flow and the electrostatic field significantly altering the electrokinetic parameters. The new description of electrokinetics of composed interfaces presented here takes into account both hydrodynamic and electric field modification and is free of the previously assumed slip plane shift caused by adsorbed

  12. Dynamic heterogeneity in life histories

    DEFF Research Database (Denmark)

    Tuljapurkar, Shripad; Steiner, Uli; Orzack, Steven Hecht

    2009-01-01

    generate dynamic heterogeneity: life-history differences produced by stochastic stratum dynamics. We characterize dynamic heterogeneity in a range of species across taxa by properties of the Markov chain: the entropy, which describes the extent of heterogeneity, and the subdominant eigenvalue, which...... distributions of lifetime reproductive success. Dynamic heterogeneity contrasts with fixed heterogeneity: unobserved differences that generate variation between life histories. We show by an example that observed distributions of lifetime reproductive success are often consistent with the claim that little...... or no fixed heterogeneity influences this trait. We propose that dynamic heterogeneity provides a 'neutral' model for assessing the possible role of unobserved 'quality' differences between individuals. We discuss fitness for dynamic life histories, and the implications of dynamic heterogeneity...

  13. Artisanal knowledge

    Directory of Open Access Journals (Sweden)

    Raven, Diederick

    2013-03-01

    Full Text Available This essay is about the ensuing problem that in general it is nothelpful to talk about non-standard knowledge practices as modeled after our Western ideas of what knowledge is. It negotiates this problem by arguing that artisanal knowledge is an independent and self-contained mode of knowledge and is arranged in three parts. In the first part an outline is given of the key assumptions of the interactionist conception of knowledge that needs to be put in place as an alternative to the basically Kantian mixture of empiricist and rationalist assumptions of the folk model of Western academic thinking about knowledge. In this interactionist conception of knowledgeartisanal knowledge gets center stage. In the second part, the notion of craftknowledge is opened up as much as possible. The third and final part takes upthe question whether craft knowledge is a cultural universal.

  14. Accessible Knowledge - Knowledge on Accessibility

    DEFF Research Database (Denmark)

    Kirkeby, Inge Mette

    2015-01-01

    Although serious efforts are made internationally and nationally, it is a slow process to make our physical environment accessible. In the actual design process, architects play a major role. But what kinds of knowledge, including research-based knowledge, do practicing architects make use of when...... designing accessible environments? The answer to the question is crucially important since it affects how knowledge is distributed and how accessibility can be ensured. In order to get first-hand knowledge about the design process and the sources from which they gain knowledge, 11 qualitative interviews...... were conducted with architects with experience of designing for accessibility. The analysis draws on two theoretical distinctions. The first is research-based knowledge versus knowledge used by architects. The second is context-independent knowledge versus context-dependent knowledge. The practitioners...

  15. Conformations of Macromolecules and their Complexes from Heterogeneous Datasets

    CERN Document Server

    Schwander, P; Ourmazd, A

    2014-01-01

    We describe a new generation of algorithms capable of mapping the structure and conformations of macromolecules and their complexes from large ensembles of heterogeneous snapshots, and demonstrate the feasibility of determining both discrete and continuous macromolecular conformational spectra. These algorithms naturally incorporate conformational heterogeneity without resort to sorting and classification, or prior knowledge of the type of heterogeneity present. They are applicable to single-particle diffraction and image datasets produced by X-ray lasers and cryo-electron microscopy, respectively, and particularly suitable for systems not easily amenable to purification or crystallization.

  16. Multilanguage parallel programming of heterogeneous machines

    Energy Technology Data Exchange (ETDEWEB)

    Bisiani, R.; Forin, A.

    1988-08-01

    The authors designed and implemented a system, Agora, that supports the development of multilanguage parallel applications for heterogeneous machines. Agora hinges on two ideas: the first one is that shared memory can be a suitable abstraction to program concurrent, multilanguage modules running on heterogeneous machines. The second one is that a shared memory abstraction can efficiently supported across different computer architectures that are not connected by a physical shared memory, for example local are network workstations or ensemble machines. Agora has been in use for more than a year. This paper describes the Agora shared memory and its software implementation on both tightly and loosely coupled architectures. Measurements of the current implementation are also included.

  17. Large epidemic thresholds emerge in heterogeneous networks of heterogeneous nodes

    CERN Document Server

    Yang, Hui; Gross, Thilo

    2015-01-01

    One of the famous results of network science states that networks with heterogeneous connectivity are more susceptible to epidemic spreading than their more homogeneous counterparts. In particular, in networks of identical nodes it has been shown that heterogeneity can lower the epidemic threshold at which epidemics can invade the system. Network heterogeneity can thus allow diseases with lower transmission probabilities to persist and spread. Here, we point out that for real world applications, this result should not be regarded independently of the intra-individual heterogeneity between people. Our results show that, if heterogeneity among people is taken into account, networks that are more heterogeneous in connectivity can be more resistant to epidemic spreading. We study a susceptible-infected-susceptible model with adaptive disease avoidance. Results from this model suggest that this reversal of the effect of network heterogeneity is likely to occur in populations in which the individuals are aware of t...

  18. Heterogeneity and Scaling in Geologic Media

    Energy Technology Data Exchange (ETDEWEB)

    Gregory N. Boitnott; Gilles Y. Bussod; Paul N. Hagin; Stephen R. Brown

    2005-04-18

    The accurate characterization and remediation of contaminated subsurface environments requires the detailed knowledge of subsurface structures and flow paths. Enormous resources are invested in scoping and characterizing sites using core sampling, 3-D geophysical surveys, well tests, etc.... Unfortunately, much of the information acquired is lost to compromises and simplifications made in constructing numerical grids for the simulators used to predict flow and transport from the contaminated area to the accessible environment. In rocks and soils, the bulk geophysical and transport properties of the matrix and of fracture systems are determined by the juxtaposition of geometric features at many length scales. In the interest of computational efficiency, recognized heterogeneities are simplified, averaged out, or entirely ignored in spite of recent studies that recognize that: (1) Structural and lithologic heterogeneities exist on all scales in rocks. (2) Small heterogeneities influence, and can control the physical and chemical properties of rocks. In this work we propose a physically based approach for the description and treatment of heterogeneities, that highlights the use of laboratory equipment designed to measure the effect on physical properties of fine scale heterogeneities observed in rocks and soils. We then discuss the development of an integration methodology that uses these measurements to develop and upscale flow and transport models. Predictive simulations are 'calibrated' to the measured heterogeneity data, and subsequently upscaled in a way that is consistent with the transport physics and the efficient use of environmental geophysics. This methodology provides a more accurate interpretation and representation of the subsurface for both environmental engineering and remediation. We show through examples, (i) the important influence of even subtle heterogeneity in the interpreting of geophysical data, and (ii) how physically based upscaling

  19. Knowledge spaces

    CERN Document Server

    Doignon, Jean-Paul

    1999-01-01

    Knowledge spaces offer a rigorous mathematical foundation for various practical systems of knowledge assessment. An example is offered by the ALEKS system (Assessment and LEarning in Knowledge Spaces), a software for the assessment of mathematical knowledge. From a mathematical standpoint, knowledge spaces generalize partially ordered sets. They are investigated both from a combinatorial and a stochastic viewpoint. The results are applied to real and simulated data. The book gives a systematic presentation of research and extends the results to new situations. It is of interest to mathematically oriented readers in education, computer science and combinatorics at research and graduate levels. The text contains numerous examples and exercises and an extensive bibliography.

  20. Entrepreneurial Couples

    DEFF Research Database (Denmark)

    Dahl, Michael S.; Van Praag, Mirjam; Thompson, Peter

    2015-01-01

    We study motivations for and outcomes of couples starting up a joint firm, using a sample of 1,069 Danish couples that established a joint enterprise between 2001 and 2010, while comparing them to a set of comparable firms and couples. The main motivation for joint entrepreneurship is to create...

  1. Integrating order and distance relationships from heterogeneous maps.

    Science.gov (United States)

    Graves, M

    1993-01-01

    There is no automatic mechanism to integrate information between heterogeneous genome maps. Currently, integration is a difficult, manual process. We have developed a process for knowledge base design, and we use this to integrate order and distance relationships between genetic linkage, radiation hybrid, and physical maps. Until now, the only way to develop a persistent, knowledge-intensive application was to either develop a new knowledge base from scratch or coerce the application to fit an existing knowledge base. This was not from lack of interest by the knowledge base or database community, but merely from a lack of theoretical tools powerful enough to tackle the problem. We import formalisms from knowledge representation, natural language semantics, programming language research, and databases. These form a strong, theoretical foundation for knowledge base design upon which we have implemented the knowledge base design tool called WEAVE.

  2. Knowledge Management

    Science.gov (United States)

    Shariq, Syed Z.; Kutler, Paul (Technical Monitor)

    1997-01-01

    The emergence of rapidly expanding technologies for distribution and dissemination of information and knowledge has brought to focus the opportunities for development of knowledge-based networks, knowledge dissemination and knowledge management technologies and their potential applications for enhancing productivity of knowledge work. The challenging and complex problems of the future can be best addressed by developing the knowledge management as a new discipline based on an integrative synthesis of hard and soft sciences. A knowledge management professional society can provide a framework for catalyzing the development of proposed synthesis as well as serve as a focal point for coordination of professional activities in the strategic areas of education, research and technology development. Preliminary concepts for the development of the knowledge management discipline and the professional society are explored. Within this context of knowledge management discipline and the professional society, potential opportunities for application of information technologies for more effectively delivering or transferring information and knowledge (i.e., resulting from the NASA's Mission to Planet Earth) for the development of policy options in critical areas of national and global importance (i.e., policy decisions in economic and environmental areas) can be explored, particularly for those policy areas where a global collaborative knowledge network is likely to be critical to the acceptance of the policies.

  3. Soil Lysimeter Excavation for Coupled Hydrological, Geochemical, and Microbiological Investigations.

    Science.gov (United States)

    Sengupta, Aditi; Wang, Yadi; Meira Neto, Antonio A; Matos, Katarena A; Dontsova, Katerina; Root, Rob; Neilson, Julie W; Maier, Raina M; Chorover, Jon; Troch, Peter A

    2016-09-11

    Studying co-evolution of hydrological and biogeochemical processes in the subsurface of natural landscapes can enhance the understanding of coupled Earth-system processes. Such knowledge is imperative in improving predictions of hydro-biogeochemical cycles, especially under climate change scenarios. We present an experimental method, designed to capture sub-surface heterogeneity of an initially homogeneous soil system. This method is based on destructive sampling of a soil lysimeter designed to simulate a small-scale hillslope. A weighing lysimeter of one cubic meter capacity was divided into sections (voxels) and was excavated layer-by-layer, with sub samples being collected from each voxel. The excavation procedure was aimed at detecting the incipient heterogeneity of the system by focusing on the spatial assessment of hydrological, geochemical, and microbiological properties of the soil. Representative results of a few physicochemical variables tested show the development of heterogeneity. Additional work to test interactions between hydrological, geochemical, and microbiological signatures is planned to interpret the observed patterns. Our study also demonstrates the possibility of carrying out similar excavations in order to observe and quantify different aspects of soil-development under varying environmental conditions and scale.

  4. Voltage-dependent K+ currents contribute to heterogeneity of olfactory ensheathing cells

    Science.gov (United States)

    Rela, Lorena; Piantanida, Ana Paula; Bordey, Angelique; Greer, Charles A.

    2015-01-01

    The olfactory nerve is permissive for axon growth throughout life. This has been attributed in part to the olfactory ensheathing glial cells that encompass the olfactory sensory neuron fascicles. Olfactory ensheathing cells also promote axon growth in vitro and when transplanted in vivo to sites of injury. The mechanisms involved remain largely unidentified owing in part to the limited knowledge of the physiological properties of ensheathing cells. Glial cells rely for many functions on the properties of the potassium channels expressed; however, those expressed in ensheathing cells are unknown. Here we show that olfactory ensheathing cells express voltage-dependent potassium currents compatible with inward rectifier (Kir) and delayed rectifier (KDR) channels. Together with gap junction coupling, these contribute to the heterogeneity of membrane properties observed in olfactory ensheathing cells. The relevance of K+ currents expressed by ensheathing cells is discussed in relation to plasticity of the olfactory nerve. PMID:25856239

  5. Characterization and modeling tools for light management in heterogeneous thin film layers

    Science.gov (United States)

    Le Rouzo, J.; Duché, D.; Ruiz, C. M.; Thierry, F.; Carlberg, M.; Berginc, G.; Pasquinelli, M.; Simon, J.-J.; Escoubas, L.; Flory, F.

    2016-09-01

    The extraordinary progresses in the design and realization of structures in inorganic or organic thin films, whether or not including nanoparticles, make it possible to develop devices with very specific properties. Mastering the links between the macroscopic optical properties and the opto-geometrical parameters of these heterogeneous layers is thus a crucial issue. We propose to present the tools used to characterize and to model thin film layers, from an optical point of view, highlighting the interest of coupling both experimental and simulation studies for improving our knowledge on the optical response of the structure. Different examples of studies are presented on CIGS, Perovskite, P3HT:ZnO, PC70BM, organic layer containing metallic nanoparticles and colored solar cells.

  6. Heterogeneity of Intellectual Assets

    DEFF Research Database (Denmark)

    Dahlgren, Johan Henrich; Lund Jensen, Rasmus; Valentin, Finn

    2004-01-01

    This paper deals with methodological issues of assessing the composition and level ofheterogeneity of firms' intellectual assets. It develops an original metric - referred to asthe H-index - for measuring heterogeneity using data extracted from patent documents.The main purpose is to improve...... the characterisation of research activities within firmsin the biotechnology sector. Although the H-index grew out of research on biotechfirms, the metric carries broader relevance for all patent-intensive industries. Themeasurement and calculation of the H-index is illustrated using some empiricalexamples from our...

  7. Knowledge Work and Knowledge Creation

    DEFF Research Database (Denmark)

    Dau, Susanne

    2016-01-01

    The purpose of this paper is to address how instruction influences the creative knowledge work. Based on different perspectives on instructions and the actions followed, this paper reveal how educators, having different competencies of ICT-instructions, influence students’ creative knowledge work......, and students’ knowledge creation....

  8. Knowledge cycle and strategic knowledge within company

    OpenAIRE

    Ovidiu NICOLESCU

    2007-01-01

    In the knowledge-based economy, a company performs a set of activities focused on knowledge: identifying necessary knowledge, buying knowledge, learning, acquiring knowledge, creating knowledge, storing knowledge, sharing knowledge, using knowledge, protection of knowledge, capitalizing knowledge. As a result, a new function emerge: the knowledge function. In the knowledge-based companies, not every knowledge has the same impact. The analysis of the actual situations in the most developed an...

  9. Knowledge Management

    Directory of Open Access Journals (Sweden)

    Ravi Kiran

    2013-04-01

    Full Text Available The present study covers the knowledge management (KM in institutions of higher technical education (IHTEs from the perspective of thought leaders and junior academia to identify whether there is a difference of opinion regarding KM strategies, including knowledge technologies, knowledge acquisition, knowledge storage, knowledge dissemination, and KM-based framework for research and curriculum development (CD. Data have been collected through structured questionnaire from 141 respondents covering 30 higher educational institutions in India, including national- and state-level institutions—Designations of the targeted respondents in the IHTEs have been categorized into (a senior academia, that is, professors, heads, and associate professors occupying senior management positions, considered to be the institute overseers and thought leaders of KM and (b junior academia consisting of assistant professors and lecturers who are using and also contributing to the KM system. ANOVA has been used to see whether there is a significant difference of opinion among the two groups of knowledge users. The results of the study highlight a significant difference among the two groups regarding knowledge technologies, knowledge acquisition, knowledge storage, and knowledge dissemination. But, there is a consensus regarding KM-based framework for research and CD.

  10. Knowledge Sharing is Knowledge Creation

    DEFF Research Database (Denmark)

    Greve, Linda

    2015-01-01

    communication and knowledge creation to an intervention study in a large Danish food production company. For some time a specific group of employees uttered a wish for knowledge sharing, but it never really happened. The group was observed and submitted to metaphor analysis as well as analysis of co......-creation strategies. Confronted with the results, the group completely altered their approach to knowledge sharing and let it become knowledge co-creation. The conclusions are, that knowledge is and can only be a diverse and differentiated concept, and that groups are able to embrace this complexity. Thus rather than...

  11. Heterogeneous photonic integrated circuits

    Science.gov (United States)

    Fang, Alexander W.; Fish, Gregory; Hall, Eric

    2012-01-01

    Photonic Integrated Circuits (PICs) have been dichotomized into circuits with high passive content (silica and silicon PLCs) and high active content (InP tunable lasers and transceivers) due to the trade-off in material characteristics used within these two classes. This has led to restrictions in the adoption of PICs to systems in which only one of the two classes of circuits are required to be made on a singular chip. Much work has been done to create convergence in these two classes by either engineering the materials to achieve the functionality of both device types on a single platform, or in epitaxial growth techniques to transfer one material to the next, but have yet to demonstrate performance equal to that of components fabricated in their native substrates. Advances in waferbonding techniques have led to a new class of heterogeneously integrated photonic circuits that allow for the concurrent use of active and passive materials within a photonic circuit, realizing components on a transferred substrate that have equivalent performance as their native substrate. In this talk, we review and compare advances made in heterogeneous integration along with demonstrations of components and circuits enabled by this technology.

  12. Heterogenous Couples in Heterosexual Marriages: Gay Men and Straight Women.

    Science.gov (United States)

    Bozett, Frederick W.

    1982-01-01

    Focuses on the spousal relationship of gay men who had been married. Describes the man's disclosure of his homosexuality, the wife's response, and the interactional effects on the marriage relationship. Suggests the wife appeared to be an enabler of his transition to a homosexual life-style. (Author/JAC)

  13. Heterogenous Couples in Heterosexual Marriages: Gay Men and Straight Women.

    Science.gov (United States)

    Bozett, Frederick W.

    1982-01-01

    Focuses on the spousal relationship of gay men who had been married. Describes the man's disclosure of his homosexuality, the wife's response, and the interactional effects on the marriage relationship. Suggests the wife appeared to be an enabler of his transition to a homosexual life-style. (Author/JAC)

  14. The heterogeneous oxidation of SO2 on aerosol surface

    Institute of Scientific and Technical Information of China (English)

    高会旺; 黄美元; 徐华英

    1997-01-01

    A heterogeneous chemical model is developed by coupling aerosol, gas-phase and liquid-phase chemical model. SO2 oxidation rates on the aerosol surface are calculated and the influence of some factors is discussed. Model simulations indicate that SO2 heterogeneous oxidation rates are sensitive to the mass concentration and chemical composition of aerosols, relative humidity, initial values of SO2 and H2O2. The heterogeneous chemical model is coupled with a Eulerian deposition model. Model results show that oxidation of SO2 on the aerosol surface is found to reduce SO2 levels by 5%-33%, to increase SO2-4 concentrations by 8%-50% in the surface layer.

  15. High Content Analysis of Compositional Heterogeneities to Study GPCR Oligomerization

    DEFF Research Database (Denmark)

    Walsh, Samuel McEwen

    In this thesis I demonstrate how the natural compositional heterogeneities of synthetic and living cell model systems can be used to quantitate the mechanics of G-protein coupled receptor (GPCR) oligomerization with Förster resonance energy transfer (FRET). The thesis is structured around three a...

  16. High Content Analysis of Compositional Heterogeneities to Study GPCR Oligomerization

    DEFF Research Database (Denmark)

    Walsh, Samuel McEwen

    In this thesis I demonstrate how the natural compositional heterogeneities of synthetic and living cell model systems can be used to quantitate the mechanics of G-protein coupled receptor (GPCR) oligomerization with Förster resonance energy transfer (FRET). The thesis is structured around three a...

  17. KNOWLEDGE CYCLE AND STRATEGIC KNOWLEDGE WITHIN COMPANY

    Directory of Open Access Journals (Sweden)

    Ovidiu NICOLESCU

    2007-01-01

    Full Text Available In the knowledge-based economy, a company performs a set of activities focused on knowledge: identifying necessary knowledge, buying knowledge, learning, acquiring knowledge, creating knowledge, storing knowledge, sharing knowledge, using knowledge, protection of knowledge, capitalizing knowledge. As a result, a new function emerge: the knowledge function. In the knowledge-based companies, not every knowledge has the same impact. The analysis of the actual situations in the most developed and highly performing companies - based in knowledge, outlines the occurrence of a new category of knowledge – strategic knowledge. Generating this category of knowledge is a new category of challenge for the scientific system.

  18. Knowledge management

    DEFF Research Database (Denmark)

    Foss, Nicolai Juul; Mahnke, Volker

    2003-01-01

    Knowledge management has emerged as a very successful organization practice and has beenextensively treated in a large body of academic work. Surprisingly, however, organizationaleconomics (i.e., transaction cost economics, agency theory, team theory and property rightstheory) has played no role...... in the development of knowledge management. We argue thatorganizational economics insights can further the theory and practice of knowledge managementin several ways. Specifically, we apply notions of contracting, team production,complementaries, hold-up, etc. to knowledge management issues (i.e., creating...

  19. Knowledge management

    DEFF Research Database (Denmark)

    Foss, Nicolai Juul; Mahnke, Volker

    2003-01-01

    in the development of knowledge management. We argue thatorganizational economics insights can further the theory and practice of knowledge managementin several ways. Specifically, we apply notions of contracting, team production,complementaries, hold-up, etc. to knowledge management issues (i.e., creating......Knowledge management has emerged as a very successful organization practice and has beenextensively treated in a large body of academic work. Surprisingly, however, organizationaleconomics (i.e., transaction cost economics, agency theory, team theory and property rightstheory) has played no role...

  20. Knowledge Economy

    OpenAIRE

    Kerr, Aphra; O'Riain, Sean

    2009-01-01

    We examine a number of key questions regarding this knowledge economy. First, we look at the origin of the concept as well as early attempts to define and map the knowledge economy empirically. Second, we examine a variety of perspectives on the socio-spatial organisation of the knowledge economy and approaches which link techno-economic change and social-spatial organisation. Building on a critique of these perspectives, we then go on to develop a view of a knowledge economy that is conteste...

  1. Disordered hyperuniform heterogeneous materials

    Science.gov (United States)

    Torquato, Salvatore

    2016-10-01

    Disordered hyperuniform many-body systems are distinguishable states of matter that lie between a crystal and liquid: they are like perfect crystals in the way they suppress large-scale density fluctuations and yet are like liquids or glasses in that they are statistically isotropic with no Bragg peaks. These systems play a vital role in a number of fundamental and applied problems: glass formation, jamming, rigidity, photonic and electronic band structure, localization of waves and excitations, self-organization, fluid dynamics, quantum systems, and pure mathematics. Much of what we know theoretically about disordered hyperuniform states of matter involves many-particle systems. In this paper, we derive new rigorous criteria that disordered hyperuniform two-phase heterogeneous materials must obey and explore their consequences. Two-phase heterogeneous media are ubiquitous; examples include composites and porous media, biological media, foams, polymer blends, granular media, cellular solids, and colloids. We begin by obtaining some results that apply to hyperuniform two-phase media in which one phase is a sphere packing in d-dimensional Euclidean space {{{R}}d} . Among other results, we rigorously establish the requirements for packings of spheres of different sizes to be ‘multihyperuniform’. We then consider hyperuniformity for general two-phase media in {{{R}}d} . Here we apply realizability conditions for an autocovariance function and its associated spectral density of a two-phase medium, and then incorporate hyperuniformity as a constraint in order to derive new conditions. We show that some functional forms can immediately be eliminated from consideration and identify other forms that are allowable. Specific examples and counterexamples are described. Contact is made with well-known microstructural models (e.g. overlapping spheres and checkerboards) as well as irregular phase-separation and Turing-type patterns. We also ascertain a family of

  2. Vertical Handoff In Wlan-Wimax-Lte Heterogeneous Networks Through Gateway Relocation

    Directory of Open Access Journals (Sweden)

    L. Nithyanandan

    2012-09-01

    Full Text Available In wireless communication new technologies emerges regularly with faster data rates and larger coverage area. Therefore the forthcoming challenge is to make the best possible use of the available heterogeneous network. For connecting mobile between heterogeneous networks vertical handoff is mandatory. IP Multimedia Subsystem is an emerging architecture for interworking of heterogeneous networks. In this paper we used WLAN/WiMAX/LTE heterogeneous networks. Coupling architectures such as tight coupling and loose coupling are considered. In order to reduce the latency two mechanisms such as neighbour bandwidth reservation and gateway relocation are employed. The parameters such as vertical handoff delay, Mobile scanning interval activity, neighbouring advertisement received are obtained. From the simulation it is inferred that tight coupling with gateway relocation is performingbetter from handover point of view.

  3. Impact of Land Surface Heterogeneity on Mesoscale Atmospheric Dispersion

    Science.gov (United States)

    Wu, Yuling; Nair, Udaysankar S.; Pielke, Roger A., Sr.; McNider, Richard T.; Christopher, Sundar A.; Anantharaj, Valentine G.

    2009-01-01

    Prior numerical modelling studies show that atmospheric dispersion is sensitive to surface heterogeneities, but past studies do not consider the impact of a realistic distribution of surface heterogeneities on mesoscale atmospheric dispersion. While these focussed on dispersion in the convective boundary layer, the present work also considers dispersion in the nocturnal boundary layer and above. Using a Lagrangian particle dispersion model (LPDM) coupled to the Eulerian Regional Atmospheric Modeling System (RAMS), the impact of topographic, vegetation, and soil moisture heterogeneities on daytime and nighttime atmospheric dispersion is examined. In addition, the sensitivity to the use of Moderate Resolution Imaging Spectroradiometer (MODIS)-derived spatial distributions of vegetation characteristics on atmospheric dispersion is also studied. The impact of vegetation and terrain heterogeneities on atmospheric dispersion is strongly modulated by soil moisture, with the nature of dispersion switching from non-Gaussian to near- Gaussian behaviour for wetter soils (fraction of saturation soil moisture content exceeding 40%). For drier soil moisture conditions, vegetation heterogeneity produces differential heating and the formation of mesoscale circulation patterns that are primarily responsible for non-Gaussian dispersion patterns. Nighttime dispersion is very sensitive to topographic, vegetation, soil moisture, and soil type heterogeneity and is distinctly non-Gaussian for heterogeneous land-surface conditions. Sensitivity studies show that soil type and vegetation heterogeneities have the most dramatic impact on atmospheric dispersion. To provide more skillful dispersion calculations, we recommend the utilisation of satellite-derived vegetation characteristics coupled with data assimilation techniques that constrain soil-vegetation-atmosphere transfer (SVAT) models to generate realistic spatial distributions of surface energy fluxes.

  4. Heterogenous networks and services

    DEFF Research Database (Denmark)

    Tan, Su-En

    the existing generation of technology and presents new technological performance breakthroughs. It is difficult to predict which radical technologies or innovations will result in a market disruption early on in their life cycles. Based on Clayton Christensen’s (Christensen 1997) definition of a disruptive...... of the market. If mainstream technology firms do not address the disruption, it is likely they will fail and the new disruptive firm will grow in size and importance in the industry. As we move to 3G (3rd Generation Mobile Services) and beyond 3G, one of the biggest challenges is to bridge network heterogeneity...... products and services. Schumpeter described the motor of development as the innovation itself. However, business and financial aspects must also be considered as they provide the bottom line for firms in the industry. Standardisation is increasingly required due to the number of different technologies...

  5. Heterogeneous logics of competition

    DEFF Research Database (Denmark)

    Mossin, Christiane

    2015-01-01

    The purpose of the article is to demonstrate that in order to understand competition as a socially organizing phenomenon, we should not examine competition in isolation, but as constellations of heterogeneous logics. More precisely, the article is based on two main theoretical points: (1) Logics...... of competition are only realized as particular forms of social organization by virtue of interplaying with other kinds of logics, like legal logics. (2) Competition logics enjoy a peculiar status in-between constructedness and givenness; although competition depends on laws and mechanisms of socialization, we...... still experience competition as an expression of spontaneous human activities. On the basis of these perspectives, a study of fundamental rights of EU law, springing from the principle of ‘free movement of people’, is conducted. The first part of the empirical analysis seeks to detect the presence...

  6. Heterogeneous logics of competition

    DEFF Research Database (Denmark)

    Mossin, Christiane

    2015-01-01

    The purpose of the article is to demonstrate that in order to understand competition as a socially organizing phenomenon, we should not examine competition in isolation, but as constellations of heterogeneous logics. More precisely, the article is based on two main theoretical points: (1) Logics...... still experience competition as an expression of spontaneous human activities. On the basis of these perspectives, a study of fundamental rights of EU law, springing from the principle of ‘free movement of people’, is conducted. The first part of the empirical analysis seeks to detect the presence...... of a presumed logic of competition within EU law, whereas the second part focuses on particular legal logics. In this respect, the so-called ‘real link criterion’ (determining the access to transnational social rights for certain groups of unemployed people) is given special attention. What is particularly...

  7. Noise and Neuronal Heterogeneity

    CERN Document Server

    Barber, Michael J

    2010-01-01

    We consider signal transaction in a simple neuronal model featuring intrinsic noise. The presence of noise limits the precision of neural responses and impacts the quality of neural signal transduction. We assess the signal transduction quality in relation to the level of noise, and show it to be maximized by a non-zero level of noise, analogous to the stochastic resonance effect. The quality enhancement occurs for a finite range of stimuli to a single neuron; we show how to construct networks of neurons that extend the range. The range increases more rapidly with network size when we make use of heterogeneous populations of neurons with a variety of thresholds, rather than homogeneous populations of neurons all with the same threshold. The limited precision of neural responses thus can have a direct effect on the optimal network structure, with diverse functional properties of the constituent neurons supporting an economical information processing strategy that reduces the metabolic costs of handling a broad...

  8. Coordinated Energy Management in Heterogeneous Processors

    Directory of Open Access Journals (Sweden)

    Indrani Paul

    2014-01-01

    Full Text Available This paper examines energy management in a heterogeneous processor consisting of an integrated CPU–GPU for high-performance computing (HPC applications. Energy management for HPC applications is challenged by their uncompromising performance requirements and complicated by the need for coordinating energy management across distinct core types – a new and less understood problem. We examine the intra-node CPU–GPU frequency sensitivity of HPC applications on tightly coupled CPU–GPU architectures as the first step in understanding power and performance optimization for a heterogeneous multi-node HPC system. The insights from this analysis form the basis of a coordinated energy management scheme, called DynaCo, for integrated CPU–GPU architectures. We implement DynaCo on a modern heterogeneous processor and compare its performance to a state-of-the-art power- and performance-management algorithm. DynaCo improves measured average energy-delay squared (ED2 product by up to 30% with less than 2% average performance loss across several exascale and other HPC workloads.

  9. Entrepreneurial Couples

    DEFF Research Database (Denmark)

    Dahl, Michael S.; Van Praag, Mirjam; Thompson, Peter

    We study possible motivations for co-entrepenurial couples to start up a joint firm, using a sample of 1,069 Danish couples that established a joint enterprise between 2001 and 2010. We compare their pre-entry characteristics, firm performance and postdissolution private and financial outcomes...... with a selected set of comparable firms and couples. We find evidence that couples often establish a business together because one spouse – most commonly the female – has limited outside opportunities in the labor market. However, the financial benefits for each of the spouses, and especially the female...

  10. Entrepreneurial Couples

    DEFF Research Database (Denmark)

    Dahl, Michael S.; Van Praag, Mirjam; Thompson, Peter

    2015-01-01

    We study possible motivations for co-entreprenurial couples to start up a joint firm, using a sample of 1,069 Danish couples that established a joint enterprise between 2001 and 2010. We compare their pre-entry characteristics, firm performance and post-dissolution private and financial outcomes...... with a selected set of comparable firms and couples. We find evidence that couples often establish a business together because one spouse – most commonly the female – has limited outside opportunities in the labor market. However, the financial benefits for each of the spouses, and especially the female...

  11. Entrepreneurial Couples

    DEFF Research Database (Denmark)

    Dahl, Michael S.; Van Praag, Mirjam; Thompson, Peter

    We study possible motivations for co-entrepenurial couples to start up a joint firm, us-ing a sample of 1,069 Danish couples that established a joint enterprise between 2001 and 2010. We compare their pre-entry characteristics, firm performance and post-dissolution private and financial outcomes...... with a selected set of comparable firms and couples. We find evidence that couples often establish a business together because one spouse - most commonly the female - has limited outside opportunities in the labor market. However, the financial benefits for each of the spouses, and especially the female...

  12. Disappearing knowledge

    Directory of Open Access Journals (Sweden)

    Nišavić Ivan

    2016-01-01

    Full Text Available Following the exposition of the basic standpoints of contextualism in relation to invariantistic position, which takes the concept of knowledge in its rigorous and fixed meaning, the text continues to deal with the analysis of the concept of knowledge offered by David Lewis, with a goal to solve common epistemological problems, one of those being the lottery paradox. Accepting fallibilism as the only plausible option regarding the possibility of acquiring knowledge, Lewis claims that, with the postulated rules that allow us to properly eliminate alternative possibilities, it is possible to resolve the previously mentioned paradox. If we want to base knowledge on probability, and not on certainty, and to directly stipulate it with the context in which it is being imposed or expressed, than it is obvious that knowledge will depend on whether the requirements for knowledge are high or low. Thus, in one case it might occur that we have knowledge, and in the other that we do not, even though nothing is changed except the conversational conditions that are already ”in the game”. Such, elusive knowledge, that gets lost, De Rose labels ”now you know it, now you don’t” and considers it to be a direct consequence of Lewis’s analysis. As such, the analysis should not be accepted.

  13. Heterogeneity in recombinant protein production

    DEFF Research Database (Denmark)

    Schalén, Martin; Johanson, Ted; Lundin, Luisa;

    2012-01-01

    contribute to make a population in a fermenter heterogeneous, resulting in cell-to-cell variation in physiological parameters of the microbial culture. Our study aims at investigating how population heterogeneity and recombinant protein production is affected by environmental gradients in bioreactors...... are simulated in small bioreactors and the population heterogeneity can be visualised by analysing single cells with flow cytometry. This can give new insights to cell physiology and recombinant protein production at the industrial scale....

  14. Knowledge brokering

    DEFF Research Database (Denmark)

    Bergenholtz, Carsten

    2011-01-01

    Purpose – The purpose of this paper is to examine how the spanning of inter-organizational weak ties and technological boundaries influences knowledge brokering. Design/methodology/approach – The paper is based on original fieldwork and employs a case study research design, investigating a Danish...... HTSF’s inter-organizational activities. Findings – The findings show how an inter-organizational search that crosses technological boundaries and is based on a network structure of weak ties can imply a reduced risk of unwanted knowledge spill-over. Research limitations/implications – By not engaging...... in strong tie collaborations a knowledge brokering organization can reduce the risk of unwanted knowledge spill-over. The risks and opportunities of knowledge spill-over furthermore rely on the nature of the technology involved and to what extent technological boundaries are crossed. Practical implications...

  15. Space Qualified Heterogeneous Processing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Space Micro proposes to develop a radiation hardened, monolithic, heterogeneous processor for space imaging and radar systems. High performance processors are needed...

  16. Mechanical heterogeneities and lithospheric extension

    Science.gov (United States)

    Duretz, Thibault; Petri, Benoit; Mohn, Geoffroy; Schenker, Filippo L.; Schmalholz, Stefan

    2016-04-01

    Detailed geological and geophysical studies of passive margins have highlighted the multi-stage and depth-dependent aspect of lithospheric thinning. Lithospheric thinning involves a variety of structures (normal faults, low angle detachments, extensional shear zones, extraction faults) and leads to a complex architecture of passive margins (with e.g. necking zone, mantle exhumation, continental allochthons). The processes controlling the generation and evolution of these structures as well as the impact of pre-rift inheritance are so far incompletely understood. In this study, we investigate the impact of pre-rift inheritance on the development of rifted margins using two-dimensional thermo-mechanical models of lithospheric thinning. To first order, we represent the pre-rift mechanical heterogeneities with lithological layering. The rheologies are kept simple (visco-plastic) and do not involve any strain softening mechanism. Our models show that mechanical layering causes multi-stage and depth-dependent extension. In the initial rifting phase, lithospheric extension is decoupled: as the crust undergoes thinning by brittle (frictional-plastic) faults, the lithospheric mantle accommodates extension by symmetric ductile necking. In a second rifting phase, deformation in the crust and lithospheric mantle is coupled and marks the beginning of an asymmetric extension stage. Low angle extensional shear zones develop across the lithosphere and exhume subcontinental mantle. Furthemore, crustal allochthons and adjacent basins develop coevally. We describe as well the thermal evolution predicted by the numerical models and discuss the first-order implications of our results in the context of the Alpine geological history.

  17. Synchronization and entrainment of coupled circadian oscillators

    CERN Document Server

    Komin, Niko; Hernandez-Garcia, Emilio; Toral, Raul

    2010-01-01

    Circadian rhythms in mammals are controlled by the neurons located in the suprachiasmatic nucleus of the hypothalamus. In physiological conditions, the system of neurons is very efficiently entrained by the 24-hour light-dark cycle. Most of the studies carried out so far emphasize the crucial role of the periodicity imposed by the light dark cycle in neuronal synchronization. Nevertheless, heterogeneity as a natural and permanent ingredient of these cellular interactions is seemingly to play a major role in these biochemical processes. In this paper we use a model that considers the neurons of the suprachiasmatic nucleus as chemically-coupled modified Goodwin oscillators, and introduce non-negligible heterogeneity in the periods of all neurons in the form of quenched noise. The system response to the light-dark cycle periodicity is studied as a function of the interneuronal coupling strength, external forcing amplitude and neuronal heterogeneity. Our results indicate that the right amount of heterogeneity hel...

  18. Chimera States in Two Populations with Heterogeneous Phase-lag

    DEFF Research Database (Denmark)

    Martens, Erik Andreas; Bick, Christian; Panaggio, Mark

    2016-01-01

    The simplest network of coupled phase-oscillators exhibiting chimera states is given by two populations with disparate intra- and inter-population coupling strengths. We explore the effects of heterogeneous coupling phase-lags between the two populations. Such heterogeneity arises naturally......-uniform synchronization, including in-phase and anti-phase synchrony, full incoherence (splay state), chimera states with phase separation of 0 or π between populations, and states where both populations remain desynchronized. These desynchronized states exhibit stable, oscillatory, and even chaotic dynamics. Moreover......, we identify the bifurcations through which chimera and desynchronized states emerge. Stable chimera states and desynchronized solutions, which do not arise for homogeneous phase-lag parameters, emerge as a result of competition between synchronized in-phase, anti-phase equilibria, and fully...

  19. Study of vehicular interactions in heterogeneous traffic

    Energy Technology Data Exchange (ETDEWEB)

    Arasan, V.T.; Krishnamurthy, K. [Indian Inst. of Technology, Madras, Chennai (India). Dept. of Civil Engineering

    2007-07-01

    In planning, design and operation of road systems, knowledge of traffic flow characteristics and the associated analytical techniques is necessary. Traffic flow represents the traffic load on the road and the interaction between these loadings and the facility capacity determines the operational performance of the system. This paper presented the results of a study that examined the basic characteristics of heterogeneous traffic flow on Indian city roads through extensive traffic surveys; revalidated the indigenously developed simulation model of heterogeneous traffic flow on mid block sections of urban roads for application of the model to study the interaction between vehicles over a wide range of traffic flow conditions; and, quantified the vehicular interactions in terms of Passenger Car Units (PCU) by applying the validated simulation model for a wide range of traffic flow conditions. The paper provided some background information on road traffic in India and discussed the simulation model and input variables. It also discussed model validation and application. It was concluded that the simulation model of heterogeneous traffic, when validated, replicated the field observed traffic flow to a satisfactory extent and that the Passenger Car Unit value of different types of vehicles varied significantly with variation in traffic volume. 9 refs., 6 tabs., 9 figs.

  20. Heterogeneous Catalysis with Renewed Attention: Principles, Theories, and Concepts

    Science.gov (United States)

    Dumeignil, Franck; Paul, Jean-Francois; Paul, Sebastien

    2017-01-01

    With the development of a strong bioeconomy sector related to the creation of next-generation biorefineries, heterogeneous catalysis is receiving renewed attention. Indeed, catalysis is at the core of biorefinery design, and many new catalysts and catalytic processes are being developed. On the one hand, they are based on knowledge acquired during…

  1. Knowledge Blogging

    DEFF Research Database (Denmark)

    Agerdal-Hjermind, Annette

    The rise of social media and web 2.0 technologies over the last few years has impacted many communication functions. One influence is organizational bloggers as knowledge mediators on government agency practices. The ways in which these organizational bloggers in their roles as experts are able...... to change, facilitate, and enable communication about a broad range of specialized knowledge areas, in a more open interactional institutional communication environment than traditional media typically offer, give rise to a set of new implications as regards the mediation of expert knowledge to the target...

  2. Interoperability of heterogeneous distributed systems

    Science.gov (United States)

    Zaschke, C.; Essendorfer, B.; Kerth, C.

    2016-05-01

    To achieve knowledge superiority in today's operations interoperability is the key. Budget restrictions as well as the complexity and multiplicity of threats combined with the fact that not single nations but whole areas are subject to attacks force nations to collaborate and share information as appropriate. Multiple data and information sources produce different kinds of data, real time and non-real time, in different formats that are disseminated to the respective command and control level for further distribution. The data is most of the time highly sensitive and restricted in terms of sharing. The question is how to make this data available to the right people at the right time with the right granularity. The Coalition Shared Data concept aims to provide a solution to these questions. It has been developed within several multinational projects and evolved over time. A continuous improvement process was established and resulted in the adaptation of the architecture as well as the technical solution and the processes it supports. Coming from the idea of making use of existing standards and basing the concept on sharing of data through standardized interfaces and formats and enabling metadata based query the concept merged with a more sophisticated service based approach. The paper addresses concepts for information sharing to facilitate interoperability between heterogeneous distributed systems. It introduces the methods that were used and the challenges that had to be overcome. Furthermore, the paper gives a perspective how the concept could be used in the future and what measures have to be taken to successfully bring it into operations.

  3. EMP coupling to ships

    Energy Technology Data Exchange (ETDEWEB)

    Deadrick, F.J.; Cabayan, H.S.; Kunz, K.F.; Bevensee, R.M.; Martin, L.C.; Egbert, R.W.

    1980-01-01

    Scale-model tests were conducted to establish the adequacy and limitations of model measurements as tools for predicting electromagnetic pulse (EMP) coupling voltages and currents to the critical antennas, cables, and metallic structures on ships. The scale-model predictions are compared with the results of the full-scale EMP simulation test of the Canadian ASW ship, HMCS Huron. (The EMP coupling predictions in this report were made without prior knowledge of the results of the data from the HMCS Huron tests.) This report establishes that the scale-model tests in conjunction with the data base from EMP coupling modules provides the necessary information for source model development and permits effective, low-cost study of particular system configurations. 184 figures, 9 tables.

  4. Placing knowledge

    DEFF Research Database (Denmark)

    Adriansen, Hanne Kirstine; Valentin, Karen; Nielsen, Gritt B.

    Internationalisation of higher education is premised by a seeming paradox: On the one hand, academic knowledge strives to be universal in the sense that it claims to produce generalizable, valid and reliable knowledge that can be used, critiqued, and redeveloped by academics from all over the world......; on the other hand, the rationale for strengthening mobility through internationalisation is based on an imagination of the potentials of particular locations (academic institutions). Intrigued by this tension between universality and particularity in academic knowledge production, this paper presents...... preliminary findings from a project that study internationalisation of higher education as an agent in the interrelated processes of place-making and knowledge-making. The project is based on three case-studies. In this paper, focus is on PhD students’ change of research environment. This is used as a case...

  5. Knowledge Fascism

    DEFF Research Database (Denmark)

    Hendricks, Vincent Fella

    2013-01-01

    Knowledge is not democratic, it is a regime. That is the clear message from Professor Vincent Hendricks. But do not be discouraged, through hard work and diligence everyone can achieve enlightenment and insight...

  6. Knowledge Test

    DEFF Research Database (Denmark)

    Sørensen, Ole Henning

    1998-01-01

    The knowledge test is about competing temporal and spatial expressions of the politics of technological development and national prosperity in contemporary society. The discussion is based on literature of national systems of innovation and industrial networks of various sorts. Similarities...

  7. Knowledge Test

    DEFF Research Database (Denmark)

    Sørensen, Ole Henning

    1998-01-01

    The knowledge test is about competing temporal and spatial expressions of the politics of technological development and national prosperity in contemporary society. The discussion is based on literature of national systems of innovation and industrial networks of various sorts. Similarities...

  8. Query Expansion Using Heterogeneous Thesauri.

    Science.gov (United States)

    Mandala, Rila; Tokunaga, Takenobu; Tanaka, Hozumi

    2000-01-01

    Proposes a method to improve the performance of information retrieval systems by expanding queries using heterogeneous thesauri. Experiments show that using heterogeneous thesauri with an appropriate weighting method results in better retrieval performance than using only one type of thesaurus. (Author/LRW)

  9. Fiscal Consolidations and Heterogeneous Expectations

    NARCIS (Netherlands)

    C. Hommes; J. Lustenhouwer; K. Mavromatis

    2015-01-01

    We analyze fiscal consolidations using a New Keynesian model where agents have heterogeneous expectations and are uncertain about the composition of consoidations. Heterogeneity in expectations may amplify expansions, stabilizing thus the debt-to-GDP ratio faster under tax based consolidations, in t

  10. Coordination Frictions and Job Heterogeneity

    DEFF Research Database (Denmark)

    Kennes, John; le Maire, Christian Daniel

    This paper develops and extends a dynamic, discrete time, job to worker matching model in which jobs are heterogeneous in equilibrium. The key assumptions of this economic environment are (i) matching is directed and (ii) coordination frictions lead to heterogeneous local labor markets. We de- rive...

  11. Query Expansion Using Heterogeneous Thesauri.

    Science.gov (United States)

    Mandala, Rila; Tokunaga, Takenobu; Tanaka, Hozumi

    2000-01-01

    Proposes a method to improve the performance of information retrieval systems by expanding queries using heterogeneous thesauri. Experiments show that using heterogeneous thesauri with an appropriate weighting method results in better retrieval performance than using only one type of thesaurus. (Author/LRW)

  12. Knowledge Gaps

    DEFF Research Database (Denmark)

    Lyles, Marjorie; Pedersen, Torben; Petersen, Bent

    2003-01-01

    The study explores what factors influence the reduction of managers' perceivedknowledge gaps in the context of the environments of foreign markets. Potentialdeterminants are derived from traditional internationalization theory as well asorganizational learning theory, including the concept......, assimilating, and utilizing knowledge - are crucial determinants ofknowledge gap elimination. In contrast, the two factors deemed essential in traditionalinternationalization process theory - elapsed time of operations and experientiallearning - are found to have no or limited effect.Key words......: Internationalization, knowledge gap, absorptive capacity, learning box....

  13. Conventionalized knowledge

    DEFF Research Database (Denmark)

    Buus, Niels

    2006-01-01

    Mental health nurses routinely hand over clinical knowledge at intershift reports. In the present study, field descriptions from prolonged fieldwork and transcripts of audio recordings of handovers were analysed discursively drawing on ethnomethodology and conversation analysis. The analysis iden...... exact clinical situations. Handing over caused a silencing of the least powerful nurses' voices, generated uncertainty, and promoted knowledge about the patients' clinical situation that was not necessarily precise or up-to-date....

  14. Knowledge Fascism

    DEFF Research Database (Denmark)

    Hendricks, Vincent Fella

    2013-01-01

    Knowledge is not democratic, it is a regime. That is the clear message from Professor Vincent Hendricks. But do not be discouraged, through hard work and diligence everyone can achieve enlightenment and insight......Knowledge is not democratic, it is a regime. That is the clear message from Professor Vincent Hendricks. But do not be discouraged, through hard work and diligence everyone can achieve enlightenment and insight...

  15. Vocabulary knowledge

    Institute of Scientific and Technical Information of China (English)

    严爽

    2016-01-01

    Knowing a word refers to more than just a matter of knowing its form, meaning, pronunciation and spelling. It also refers to one's knowledge of the relationships the word is involved in, such as its collocations, semantic associations and so on. Words are not isolated entities. This paper focuses on vocabulary knowledge and helps us get an idea of what needs to be learned and the process of English vocabulary learning.

  16. Knowledge Management

    DEFF Research Database (Denmark)

    Hald Nielsen, Bo; Nicolajsen, Katrine

    For Økonomistyrelsen opstilles en teoretisk model over forudsætningerne for, at mmah er kan anvende knowledge management. Praksis vurderes dernæst i forhold til denne model.......For Økonomistyrelsen opstilles en teoretisk model over forudsætningerne for, at mmah er kan anvende knowledge management. Praksis vurderes dernæst i forhold til denne model....

  17. Knowledge Management

    DEFF Research Database (Denmark)

    Hald Nielsen, Bo; Nicolajsen, Katrine

    For Økonomistyrelsen opstilles en teoretisk model over forudsætningerne for, at mmah er kan anvende knowledge management. Praksis vurderes dernæst i forhold til denne model.......For Økonomistyrelsen opstilles en teoretisk model over forudsætningerne for, at mmah er kan anvende knowledge management. Praksis vurderes dernæst i forhold til denne model....

  18. Aqueous reactive species induced by a surface air discharge: Heterogeneous mass transfer and liquid chemistry pathways.

    Science.gov (United States)

    Liu, D X; Liu, Z C; Chen, C; Yang, A J; Li, D; Rong, M Z; Chen, H L; Kong, M G

    2016-04-01

    Plasma-liquid interaction is a critical area of plasma science and a knowledge bottleneck for many promising applications. In this paper, the interaction between a surface air discharge and its downstream sample of deionized water is studied with a system-level computational model, which has previously reached good agreement with experimental results. Our computational results reveal that the plasma-induced aqueous species are mainly H(+), nitrate, nitrite, H2O2 and O3. In addition, various short-lived aqueous species are also induced, regardless whether they are generated in the gas phase first. The production/loss pathways for aqueous species are quantified for an air gap width ranging from 0.1 to 2 cm, of which heterogeneous mass transfer and liquid chemistry are found to play a dominant role. The short-lived reactive oxygen species (ROS) and reactive nitrogen species (RNS) are strongly coupled in liquid-phase reactions: NO3 is an important precursor for short-lived ROS, and in turn OH, O2(-) and HO2 play a crucial role for the production of short-lived RNS. Also, heterogeneous mass transfer depends strongly on the air gap width, resulting in two distinct scenarios separated by a critical air gap of 0.5 cm. The liquid chemistry is significantly different in these two scenarios.

  19. Aqueous reactive species induced by a surface air discharge: Heterogeneous mass transfer and liquid chemistry pathways

    Science.gov (United States)

    Liu, D. X.; Liu, Z. C.; Chen, C.; Yang, A. J.; Li, D.; Rong, M. Z.; Chen, H. L.; Kong, M. G.

    2016-01-01

    Plasma-liquid interaction is a critical area of plasma science and a knowledge bottleneck for many promising applications. In this paper, the interaction between a surface air discharge and its downstream sample of deionized water is studied with a system-level computational model, which has previously reached good agreement with experimental results. Our computational results reveal that the plasma-induced aqueous species are mainly H+, nitrate, nitrite, H2O2 and O3. In addition, various short-lived aqueous species are also induced, regardless whether they are generated in the gas phase first. The production/loss pathways for aqueous species are quantified for an air gap width ranging from 0.1 to 2 cm, of which heterogeneous mass transfer and liquid chemistry are found to play a dominant role. The short-lived reactive oxygen species (ROS) and reactive nitrogen species (RNS) are strongly coupled in liquid-phase reactions: NO3 is an important precursor for short-lived ROS, and in turn OH, O2− and HO2 play a crucial role for the production of short-lived RNS. Also, heterogeneous mass transfer depends strongly on the air gap width, resulting in two distinct scenarios separated by a critical air gap of 0.5 cm. The liquid chemistry is significantly different in these two scenarios. PMID:27033381

  20. Modeling mechanical response of heterogeneous materials

    Science.gov (United States)

    Pal, Siladitya

    Heterogeneous materials are ubiquitous in nature and as synthetic materials. These materials provide unique combination of desirable mechanical properties emerging from its heterogeneities at different length scales. Future structural and technological applications will require the development of advanced light weight materials with superior strength and toughness. Cost effective design of the advanced high performance synthetic materials by tailoring their microstructure is the challenge facing the materials design community. Prior knowledge of structure-property relationships for these materials is imperative for optimal design. Thus, understanding such relationships for heterogeneous materials is of primary interest. Furthermore, computational burden is becoming critical concern in several areas of heterogeneous materials design. Therefore, computationally efficient and accurate predictive tools are highly essential. In the present study, we mainly focus on mechanical behavior of soft cellular materials and tough biological material such as mussel byssus thread. Cellular materials exhibit microstructural heterogeneity by interconnected network of same material phase. However, mussel byssus thread comprises of two distinct material phases. A robust numerical framework is developed to investigate the micromechanisms behind the macroscopic response of both of these materials. Using this framework, effect of microstuctural parameters has been addressed on the stress state of cellular specimens during split Hopkinson pressure bar test. A voronoi tessellation based algorithm has been developed to simulate the cellular microstructure. Micromechanisms (microinertia, microbuckling and microbending) governing macroscopic behavior of cellular solids are investigated thoroughly with respect to various microstructural and loading parameters. To understand the origin of high toughness of mussel byssus thread, a Genetic Algorithm (GA) based optimization framework has been

  1. Heterogeneity: multilingualism and democracy

    Directory of Open Access Journals (Sweden)

    Hans-Jürgen Krumm

    2004-01-01

    Full Text Available Linguistic diversity and multilingualism on the part of individuals are aprerequisite and a constitutive condition of enabling people to live togetherin a world of growing heterogeneity. Foreign language teaching plays animportant part in democratic education because it can be seen as a trainingin respecting otherness and developing an intercultural, non-ethnocentricperception and attitude. This is all the more important because of the neces-sity of integrating children from migrant families into school life.My article argues that language education policy has to take this per-spective into account, i.e., of establishing a planned diversification so thatpupils (and their parents will not feel satisfied with learning English only,but also become motivated to learn languages of their own neighbourhood,such as migrant and minority languages. However, in order to make use ofthe linguistic resources in the classroom, relating it to the democratic impetusof foreign language education, it is necessary to revise existing languagepolicies and to develop a multilingual perspective for all educational institutions.

  2. Heterogeneous recording media

    Science.gov (United States)

    Sukhanov, Vitaly I.

    1991-02-01

    The paper summarizes the results of investigations performed to obtain deep 3-D holograms with 102 i0 mkm physical thickness allowing the postexposure amplification and the a posteriori changing of the grating parameters. This aim has been achieved by developing heterogeneous systems on the basis of porous glass with light-sensitive compositions introduced into it. 1. INTRODUCTION. LIGHT-SENSITIVE MEDIA FOR 3-D HOLOGRAMS RECORDING. The 3-D holograms have many useful properties: very high diffraction efficiency angular and spectral selectivity but low level of noise. It shoud be noted that in this case deep 3-D holograms are dealt with whose physical thickness is as high as 102 -i mkm. Such hologram recording is usually done using homogeneous light-sensitive media for example dyed acid-halide and electrooptical crystals photochrome glass photostructurized polimer compositions and so on. The nature of photophisical and photochemical processes responsible for the light sensitivity of these materials exclude the possibility of post-exposure treatment. This does not allow to enhance the recorded holograms and considerably hampers their fixing or makes it practically impossible. The object of our work is to create the media which are quite suitable for two-stage processes of the deep hologram formation with post-exposure processing. Such material must satisfy the following requirements: a)they must have high permeability for the developing substances in order to make the development duration suitable for practical applications b)they must be shrinkproof to prevent deformation of the

  3. Parsing Heterogeneous Striatal Activity

    Directory of Open Access Journals (Sweden)

    Kae Nakamura

    2017-05-01

    Full Text Available The striatum is an input channel of the basal ganglia and is well known to be involved in reward-based decision making and learning. At the macroscopic level, the striatum has been postulated to contain parallel functional modules, each of which includes neurons that perform similar computations to support selection of appropriate actions for different task contexts. At the single-neuron level, however, recent studies in monkeys and rodents have revealed heterogeneity in neuronal activity even within restricted modules of the striatum. Looking for generality in the complex striatal activity patterns, here we briefly survey several types of striatal activity, focusing on their usefulness for mediating behaviors. In particular, we focus on two types of behavioral tasks: reward-based tasks that use salient sensory cues and manipulate outcomes associated with the cues; and perceptual decision tasks that manipulate the quality of noisy sensory cues and associate all correct decisions with the same outcome. Guided by previous insights on the modular organization and general selection-related functions of the basal ganglia, we relate striatal activity patterns on these tasks to two types of computations: implementation of selection and evaluation. We suggest that a parsing with the selection/evaluation categories encourages a focus on the functional commonalities revealed by studies with different animal models and behavioral tasks, instead of a focus on aspects of striatal activity that may be specific to a particular task setting. We then highlight several questions in the selection-evaluation framework for future explorations.

  4. "I don't know if this is right … but this is what I'm offering": healthcare provider knowledge, practice, and attitudes towards safer conception for HIV-affected couples in the context of Southern African guidelines.

    Science.gov (United States)

    West, Nora; Schwartz, Sheree; Phofa, Rebecca; Yende, Nompumelelo; Bassett, Jean; Sanne, Ian; Van Rie, Annelies

    2016-01-01

    The 2011 guidelines for safer conception for HIV-affected individuals and couples were adopted by the South African Department of Health in December 2012. We assessed implementation gaps and facilitators and barriers to delivering safer conception services through examining patient and healthcare provider (HCP) experiences. At Witkoppen Health and Welfare Centre, a primary care clinic in Johannesburg, we conducted in-depth interviews (IDIs) with nine HCPs (doctors, nurses, and counselors) and IDIs and focus group discussions with 42 HIV-affected men and women interested in having a child. Data were analyzed using a grounded theory approach. HCPs were supportive of fertility intentions of HIV-affected couples and demonstrated some knowledge of safer conception methods, especially ART initiation to suppress viral load in infected partners. Unfortunately, HCPs did not follow the key recommendation that HCPs initiate conversations on fertility intentions with HIV-affected men and women. Providers and clients reported that conversations about conception only occur when client-initiated, placing the onus on HIV-affected individuals. Important barriers underlying this were the misconception held by some HCPs that uninfected partners in serodiscordant partnerships are "latently" infected and the desire by most HCPs to protect or control knowledge around fertility and safer conception methods out of concern over what clients will do with this knowledge before they are virally suppressed or ready to conceive. Almost all participants who had conceived or attempted conception did so without safer conception methods knowledge. HCP concern over conception readiness, perception of what clients will do with safer conception knowledge, and gaps in safer conception knowledge prevent HCPs from initiating conversations with HIV-affected patients on the issue of childbearing. Examining these findings in the context of existing South African guidelines illuminates areas that need to be

  5. DEVELOPMENT OF HETEROGENEITY INDEX FOR ASSESSMENT OF RELATIONSHIP BETWEEN LAND USE PATTERN AND TRAFFIC CONGESTION

    Directory of Open Access Journals (Sweden)

    Alok Bhushan Mukherjee

    2014-12-01

    Full Text Available The present study was carried out to determine the effects of the heterogeneity in land use distribution pattern on the traffic congestion in rapidly urbanizing Ranchi city, capital of Jharkhand state, India. Traditionally, researchers have used the landscape metrics to determine the heterogeneity in the land use and land cover distribution pattern in both urban and non-urban areas. In the present study, we have introduced a new index: Heterogeneity Index to quantify the distribution pattern of the land use categories present along the various road segments whereas traffic congestion was determined through the Congestion Index Value. Based on the dominant land use categories existing in the study area, four heterogeneity indices were developed such as Residential Heterogeneity Index, Commercial Heterogeneity Index, Industrial Heterogeneity Index and Urban Services Heterogeneity Index, respectively. Finally, a Cumulative Heterogeneity Index was developed to determine the aggregate effect of the heterogeneity of the various land use categories present in the individual roads. Analytical Hierarchical Processing and knowledge-based weighting were used to rank the importance of different heterogeneity indices. The results of the investigation showed positive relationship between the degree of heterogeneity of the land use pattern and traffic congestion.

  6. The Membrane: Transertion as an organizing principle in membrane heterogeneity

    Directory of Open Access Journals (Sweden)

    Kouji eMatsumoto

    2015-06-01

    Full Text Available The bacterial membrane exhibits a significantly heterogeneous distribution of lipids and proteins. This heterogeneity results mainly from lipid-lipid, protein-protein and lipid-protein associations which are orchestrated by the coupled transcription, translation and insertion of nascent proteins into and through membrane (transertion. Transertion is central not only to the individual assembly and disassembly of large physically linked groups of macromolecules (alias hyperstructures but also to the interactions between these hyperstructures. We review here these interactions in the context of the processes in Bacillus subtilis and Escherichia coli of nutrient sensing, membrane synthesis, cytoskeletal dynamics, DNA replication, chromosome segregation and cell division.

  7. PRAGMATIC KNOWLEDGE OR NOBLE KNOWLEDGE?

    Directory of Open Access Journals (Sweden)

    Marian MANOLESCU

    2015-11-01

    Full Text Available Disputes about the opportunity to introduce competence-based education are increasingly present in terms of educational policies and strategies. Obviously, in the last decade and a half, several countries have introduced competence based education. Although specific knowledge acquisition should be an essential component of student learning, assessing such knowledge in adult life depends largely on the individual purchase of more general concepts and skills. The article discusses pragmatic knowledge and noble knowledge. This is a collective dilemma, to the extent that the education system lives in the tension between the two logics. The two positions or divergent attitudes can coexist as long ast hey do not become extremist. Educational dilemma is especially now a priority.

  8. Knowledge Model: Project Knowledge Management

    DEFF Research Database (Denmark)

    Durao, Frederico; Dolog, Peter; Grolin, Daniel

    2009-01-01

    The Knowledge model for project management serves several goals:Introducing relevant concepts of project management area for software development (Section 1). Reviewing and understanding the real case requirements from the industrial perspective. (Section 2). Giving some preliminary suggestions f...

  9. Knowledge Model: Project Knowledge Management

    DEFF Research Database (Denmark)

    Durao, Frederico; Dolog, Peter; Grolin, Daniel

    2009-01-01

    The Knowledge model for project management serves several goals:Introducing relevant concepts of project management area for software development (Section 1). Reviewing and understanding the real case requirements from the industrial perspective. (Section 2). Giving some preliminary suggestions...

  10. Nonadiabatic Coupling

    Science.gov (United States)

    Kryachko, Eugene S.

    The general features of the nonadiabatic coupling and its relation to molecular properties are surveyed. Some consequences of the [`]equation of motion', formally expressing a [`]smoothness' of a given molecular property within the diabatic basis, are demonstrated. A particular emphasis is made on the relation between a [`]smoothness' of the electronic dipole moment and the generalized Mulliken-Hush formula for the diabatic electronic coupling.

  11. Integration Of Data From Heterogeneous Sources Using Etl Technology.

    Directory of Open Access Journals (Sweden)

    Marek Macura

    2014-01-01

    Full Text Available Data integration is a crucial issue in environments of heterogeneous data sources. At present mentioned heterogeneity is becoming widespread. Whenever, based on various data sources, we want to gain useful information and knowledge we must solve data integration problem in order to apply appropriate analytical methods on comprehensive and uniform data. Such activity is known as knowledge discovery from data process. Therefore approaches to data integration problem are very interesting and bring us closer to the "age of information". The paper presents an architecture, which implements knowledge discovery from data process. The solution combines ETL technology and wrapper layer known from mediated systems. It also provides semantic integration through connections mechanism between data elements. The solution allows for integration of any data sources and implementation of analytical methods in one environment. The proposed environment is verified by applying it to data sources on the foundry industry.

  12. Lifelong Transfer Learning for Heterogeneous Teams of Agents in Sequential Decision Processes

    Science.gov (United States)

    2016-06-01

    LIFELONG TRANSFER LEARNING FOR HETEROGENEOUS TEAMS OF AGENTS IN SEQUENTIAL DECISION PROCESSES WASHINGTON STATE UNIVERSITY JUNE...TRANSFER LEARNING FOR HETEROGENEOUS TEAMS OF AGENTS IN SEQUENTIAL DECISION PROCESSES 5a. CONTRACT NUMBER N/A 5b. GRANT NUMBER FA8750-14-1-0069 5c...continually build upon and refine our knowledge. Recent work on transfer in machine learning for autonomous systems has demonstrated that knowledge

  13. Knowledge brokering:

    DEFF Research Database (Denmark)

    Bergenholtz, Carsten

    2010-01-01

    In the recent years a number of studies have explored different inter-organizational search strategies in relation to knowledge brokering and innovation performance. So far there has been very limited research that involves a crossing of both organizational and technological boundaries that also......-organizational search strategy that spans technological boundaries and involves the formation and search among weak ties. The findings show how knowledge brokering is influenced by the make-up of the technology involved, the technological distance between the two parties and why weak ties are less likely to collaborate...... on such an opportunity, than a strong tie would be. Furthermore, a number of organizational enablers for this open inter-organizational search and knowledge brokering strategy are identified. The main arguments point to the role of a general technological competence and the R&D department being the networking department....

  14. Knowledge Gaps

    DEFF Research Database (Denmark)

    Lyles, Marjorie; Pedersen, Torben; Petersen, Bent

    2003-01-01

    of absorptive capacity. Building onthese literature streams a conceptual model is developed and tested on a set of primarydata of Danish firms and their foreign market operations. The empirical study suggeststhat the factors that pertain to the absorptive capacity concept - capabilities ofrecognizing......, assimilating, and utilizing knowledge - are crucial determinants ofknowledge gap elimination. In contrast, the two factors deemed essential in traditionalinternationalization process theory - elapsed time of operations and experientiallearning - are found to have no or limited effect.Key words......: Internationalization, knowledge gap, absorptive capacity, learning box....

  15. Knowledge Granularity and Representation of Knowledge: Towards Knowledge Grid

    OpenAIRE

    Mach, Maria A.; Owoc, Mieczyslaw L.

    2010-01-01

    International audience; Knowledge granularity, usually identified with the size of knowledge granules, seems to be real challenge for knowledge consumers as well as for knowledge creators. In this paper, relationships between knowledge granularity as a result of different ways of a knowledge representation are considered. The paper deals with the problem of developing knowledge grid in the context of encapsulation of knowledge including different dimensions and measures. The origin of the pro...

  16. Knowledge Blogging

    DEFF Research Database (Denmark)

    Agerdal-Hjermind, Annette

    The rise of social media and web 2.0 technologies over the last few years has impacted many communication functions. One influence is organizational bloggers as knowledge mediators on government agency practices. The ways in which these organizational bloggers in their roles as experts are able t...

  17. Solid knowledge

    DEFF Research Database (Denmark)

    Brix, Anders

    2008-01-01

    The great icons of industrial and architectural design are cornerstones of our material culture. They are referred to again and again in education, research and cultural debate, and as such they have become nodal points of human discourse. The knowledge embedded in such artefacts has often been...... referred to as ‘silent knowledge’....

  18. Homogeneous, Heterogeneous, and Enzymatic Catalysis.

    Science.gov (United States)

    Oyama, S. Ted; Somorjai, Gabor A.

    1988-01-01

    Discusses three areas of catalysis: homegeneous, heterogeneous, and enzymatic. Explains fundamentals and economic impact of catalysis. Lists and discusses common industrial catalysts. Provides a list of 107 references. (MVL)

  19. Heterogeneity, correlations and financial contagion

    OpenAIRE

    FABIO CACCIOLI; Thomas A. Catanach; J Doyne Farmer

    2011-01-01

    We consider a model of contagion in financial networks recently introduced in Gai, P. and Kapadia, S. [Contagion in financial networks, Proc. R. Soc. A 466(2120) (2010) 2401–2423], and we characterize the effect of a few features empirically observed in real networks on the stability of the system. Notably, we consider the effect of heterogeneous degree distributions, heterogeneous balance sheet size and degree correlations between banks. We study the probability of contagion conditional on t...

  20. How landscape heterogeneity frames optimal diffusivity in searching processes.

    Directory of Open Access Journals (Sweden)

    E P Raposo

    2011-11-01

    Full Text Available Theoretical and empirical investigations of search strategies typically have failed to distinguish the distinct roles played by density versus patchiness of resources. It is well known that motility and diffusivity of organisms often increase in environments with low density of resources, but thus far there has been little progress in understanding the specific role of landscape heterogeneity and disorder on random, non-oriented motility. Here we address the general question of how the landscape heterogeneity affects the efficiency of encounter interactions under global constant density of scarce resources. We unveil the key mechanism coupling the landscape structure with optimal search diffusivity. In particular, our main result leads to an empirically testable prediction: enhanced diffusivity (including superdiffusive searches, with shift in the diffusion exponent, favors the success of target encounters in heterogeneous landscapes.

  1. Mixing, spreading and reaction in heterogeneous media: a brief review.

    Science.gov (United States)

    Dentz, Marco; Le Borgne, Tanguy; Englert, Andreas; Bijeljic, Branko

    2011-03-01

    Geological media exhibit heterogeneities in their hydraulic and chemical properties, which can lead to enhanced spreading and mixing of the transported species and induce an effective reaction behavior that is different from the one for a homogeneous medium. Chemical heterogeneities such as spatially varying adsorption properties and specific reactive surface areas can act directly on the chemical reaction dynamics and lead to different effective reaction laws. Physical heterogeneities affect mixing-limited chemical reactions in an indirect way by their impact on spreading and mixing of dissolved species. To understand and model large-scale reactive transport the interactions of these coupled processes need to be understood and quantified. This paper provides a brief review on approaches of non-reactive and reactive transport modeling in geological media.

  2. Thermal Maps of Gases in Heterogeneous Reactions

    CERN Document Server

    Jarenwattananon, Nanette N; Otto, Trenton; Melkonian, Arek; Morris, William; Burt, Scott R; Yaghi, Omar M; Bouchard, Louis-S

    2015-01-01

    Over 85% of all chemical industry products are made using catalysts, with the overwhelming majority of these employing heterogeneous catalysts functioning at the gas-solid interface. Consequently, optimizing catalytic reactor design attracts much effort. Such optimization relies on heat transfer and fluid dynamics modeling coupled to surface reaction kinetics. The complexity of these systems demands many approximations, which can only be tested with experimental observations of quantities such as temperature, pressure, concentrations, flow rates, etc. One essential measurement is a map of the spatial variation in temperature throughout the catalyst bed. We present here the first non-invasive maps of gas temperatures in catalyst-filled reactors, including high spatial resolution maps in microreactors enabled by parahydrogen. The thermal maps reveal energy flux patterns whose length scale correlates with the catalyst packing. By exploiting the motional averaging under a weak applied magnetic-field gradient, the...

  3. Probing Electrode Heterogeneity Using Fourier-Transformed Alternating Current Voltammetry: Application to a Dual-Electrode Configuration.

    Science.gov (United States)

    Tan, Sze-Yin; Unwin, Patrick R; Macpherson, Julie V; Zhang, Jie; Bond, Alan M

    2017-03-07

    Quantitative studies of electron transfer processes at electrode/electrolyte interfaces, originally developed for homogeneous liquid mercury or metallic electrodes, are difficult to adapt to the spatially heterogeneous nanostructured electrode materials that are now commonly used in modern electrochemistry. In this study, the impact of surface heterogeneity on Fourier-transformed alternating current voltammetry (FTACV) has been investigated theoretically under the simplest possible conditions where no overlap of diffusion layers occurs and where numerical simulations based on a 1D diffusion model are sufficient to describe the mass transport problem. Experimental data that meet these requirements can be obtained with the aqueous [Ru(NH3)6](3+/2+) redox process at a dual-electrode system comprised of electrically coupled but well-separated glassy carbon (GC) and boron-doped diamond (BDD) electrodes. Simulated and experimental FTACV data obtained with this electrode configuration, and where distinctly different heterogeneous charge transfer rate constants (k(0) values) apply at the individual GC and BDD electrode surfaces, are in excellent agreement. Principally, because of the far greater dependence of the AC current magnitude on k(0), it is straightforward with the FTACV method to resolve electrochemical heterogeneities that are ∼1-2 orders of magnitude apart, as applies in the [Ru(NH3)6](3+/2+) dual-electrode configuration experiments, without prior knowledge of the individual kinetic parameters (k(0)1 and k(0)2) or the electrode size ratio (θ1:θ2). In direct current voltammetry, a difference in k(0) of >3 orders of magnitude is required to make this distinction.

  4. Sanctioning Knowledge

    Directory of Open Access Journals (Sweden)

    Brentjes, Sonja

    2014-06-01

    Full Text Available In this paper, I discuss stories about rulers and princes of three dynasties - Abbasid, Norman and Timurid – and their narrative representation as prime knowers of the mathematical sciences, geography and history. I argue that they constitute one set of positive forms of sanctioning or contesting knowledge in those societies by prescribing hierarchies of knowledge forms and hierarchies of people and institutions that decide about the veracity of knowledge. I suggest that these stories share their origin and meaning in an environment of legitimizing propaganda for the various rulers and princes. I also claim that the value and position of scientific knowledge in these stories differ, starting from what apparently were personal interests of a ruler and leading to its integration into what was considered necessary for the education of a prince and the cultured behaviour of a ruler. Hence, these stories about knowledge and rulers present images of knowledge that delineate the status of scholars in those three societies and thus define possibilities and set boundaries for learning and practicing scholarly fields.En este artículo se estudian historias sobre gobernantes y príncipes de tres dinastías - ‛abbāsí, normanda y timurí – y su representación narrativa como conocedores de las ciencias matemáticas, la geografía y la historia. Se argumenta que constituyen un conjunto de formas positivas de aprobar o impugnar el conocimiento en esas sociedades, prescribiendo jerarquías de formas de conocimiento y jerarquías de gentes e instituciones que deciden acerca de la veracidad del conocimiento. Se sugiere que esas historias comparten su origen y significado en un contexto de propaganda legitimadora para varios gobernantes y príncipes. También se afirma que el valor y la posición del conocimiento científico en esas historias difieren, empezando por lo que en apariencia eran los intereses personales de un gobernante hasta su integraci

  5. Heterogeneity of Calcium Channel/cAMP-Dependent Transcriptional Activation.

    Science.gov (United States)

    Kobrinsky, Evgeny

    2015-01-01

    The major function of the voltage-gated calcium channels is to provide the Ca(2+) flux into the cell. L-type voltage-gated calcium channels (Cav1) serve as voltage sensors that couple membrane depolarization to many intracellular processes. Electrical activity in excitable cells affects gene expression through signaling pathways involved in the excitation-transcription (E-T) coupling. E-T coupling starts with activation of the Cav1 channel and results in initiation of the cAMP-response element binding protein (CREB)-dependent transcription. In this review we discuss the new quantitative approaches to measuring E-T signaling events. We describe the use of wavelet transform to detect heterogeneity of transcriptional activation in nuclei. Furthermore, we discuss the properties of discovered microdomains of nuclear signaling associated with the E-T coupling and the basis of the frequency-dependent transcriptional regulation.

  6. Dynamics of phase oscillators with generalized frequency-weighted coupling

    Science.gov (United States)

    Xu, Can; Gao, Jian; Xiang, Hairong; Jia, Wenjing; Guan, Shuguang; Zheng, Zhigang

    2016-12-01

    Heterogeneous coupling patterns among interacting elements are ubiquitous in real systems ranging from physics, chemistry to biology communities, which have attracted much attention during recent years. In this paper, we extend the Kuramoto model by considering a particular heterogeneous coupling scheme in an ensemble of phase oscillators, where each oscillator pair interacts with different coupling strength that is weighted by a general function of the natural frequency. The Kuramoto theory for the transition to synchronization can be explicitly generalized, such as the expression for the critical coupling strength. Also, a self-consistency approach is developed to predict the stationary states in the thermodynamic limit. Moreover, Landau damping effects are further revealed by means of linear stability analysis and resonance poles theory below the critical threshold, which turns to be far more generic. Our theoretical analysis and numerical results are consistent with each other, which can help us understand the synchronization transition in general networks with heterogenous couplings.

  7. Practical knowledge

    DEFF Research Database (Denmark)

    2006-01-01

    The chapter aims to develop conceptions of practical knowledge, relevant to skills and Bildung in engineering science. The starting point is Francis Bacon’s ideas of new science, developed 400 years ago. It is argued that Bacon’s vision has become dogmatized during the course of history, whereas...... his critical attitude has become superseded. A critical discussion on the heritage from Bacon leads to a focus on the concepts of truth, utility, and goodness. Unification of skills and Bildung, it is stated, should imply the ability to deal explicitly with these concepts and their interrelations....... Furthermore, and still with reference to truth, utility, and goodness, it is claimed that unification of skills and Bildung should include the ability to deal with complexity. A second-order complexity challenges the search for adequacy between; a) the complexity of knowledge-creation; and b) the complexity...

  8. Knowledge brokering:

    DEFF Research Database (Denmark)

    Bergenholtz, Carsten

    2010-01-01

    In the recent years a number of studies have explored different inter-organizational search strategies in relation to knowledge brokering and innovation performance. So far there has been very limited research that involves a crossing of both organizational and technological boundaries that also...... includes a perspective on the strength of the organizational relation. In this paper, an in-depth case study of a High-Tech-Small-Firm (HTSF) is presented. By combining the literature on inter-organizational search and social networks, the study contributes by showing the implications of an inter......-organizational search strategy that spans technological boundaries and involves the formation and search among weak ties. The findings show how knowledge brokering is influenced by the make-up of the technology involved, the technological distance between the two parties and why weak ties are less likely to collaborate...

  9. Post-seismic relaxation theory on laterally heterogeneous viscoelastic model

    Science.gov (United States)

    Pollitz, F.F.

    2003-01-01

    Investigation was carried out into the problem of relaxation of a laterally heterogeneous viscoelastic Earth following an impulsive moment release event. The formal solution utilizes a semi-analytic solution for post-seismic deformation on a laterally homogeneous Earth constructed from viscoelastic normal modes, followed by application of mode coupling theory to derive the response on the aspherical Earth. The solution is constructed in the Laplace transform domain using the correspondence principle and is valid for any linear constitutive relationship between stress and strain. The specific implementation described in this paper is a semi-analytic discretization method which assumes isotropic elastic structure and a Maxwell constitutive relation. It accounts for viscoelastic-gravitational coupling under lateral variations in elastic parameters and viscosity. For a given viscoelastic structure and minimum wavelength scale, the computational effort involved with the numerical algorithm is proportional to the volume of the laterally heterogeneous region. Examples are presented of the calculation of post-seismic relaxation with a shallow, laterally heterogeneous volume following synthetic impulsive seismic events, and they illustrate the potentially large effect of regional 3-D heterogeneities on regional deformation patterns.

  10. Impact of Degree Heterogeneity on Attack Vulnerability of Interdependent Networks

    Science.gov (United States)

    Sun, Shiwen; Wu, Yafang; Ma, Yilin; Wang, Li; Gao, Zhongke; Xia, Chengyi

    2016-09-01

    The study of interdependent networks has become a new research focus in recent years. We focus on one fundamental property of interdependent networks: vulnerability. Previous studies mainly focused on the impact of topological properties upon interdependent networks under random attacks, the effect of degree heterogeneity on structural vulnerability of interdependent networks under intentional attacks, however, is still unexplored. In order to deeply understand the role of degree distribution and in particular degree heterogeneity, we construct an interdependent system model which consists of two networks whose extent of degree heterogeneity can be controlled simultaneously by a tuning parameter. Meanwhile, a new quantity, which can better measure the performance of interdependent networks after attack, is proposed. Numerical simulation results demonstrate that degree heterogeneity can significantly increase the vulnerability of both single and interdependent networks. Moreover, it is found that interdependent links between two networks make the entire system much more fragile to attacks. Enhancing coupling strength between networks can greatly increase the fragility of both networks against targeted attacks, which is most evident under the case of max-max assortative coupling. Current results can help to deepen the understanding of structural complexity of complex real-world systems.

  11. Chimera states in two populations with heterogeneous phase-lag

    Science.gov (United States)

    Martens, Erik A.; Bick, Christian; Panaggio, Mark J.

    2016-09-01

    The simplest network of coupled phase-oscillators exhibiting chimera states is given by two populations with disparate intra- and inter-population coupling strengths. We explore the effects of heterogeneous coupling phase-lags between the two populations. Such heterogeneity arises naturally in various settings, for example, as an approximation to transmission delays, excitatory-inhibitory interactions, or as amplitude and phase responses of oscillators with electrical or mechanical coupling. We find that breaking the phase-lag symmetry results in a variety of states with uniform and non-uniform synchronization, including in-phase and anti-phase synchrony, full incoherence (splay state), chimera states with phase separation of 0 or π between populations, and states where both populations remain desynchronized. These desynchronized states exhibit stable, oscillatory, and even chaotic dynamics. Moreover, we identify the bifurcations through which chimeras emerge. Stable chimera states and desynchronized solutions, which do not arise for homogeneous phase-lag parameters, emerge as a result of competition between synchronized in-phase, anti-phase equilibria, and fully incoherent states when the phase-lags are near ± /π 2 (cosine coupling). These findings elucidate previous experimental results involving a network of mechanical oscillators and provide further insight into the breakdown of synchrony in biological systems.

  12. Chimera states in two populations with heterogeneous phase-lag.

    Science.gov (United States)

    Martens, Erik A; Bick, Christian; Panaggio, Mark J

    2016-09-01

    The simplest network of coupled phase-oscillators exhibiting chimera states is given by two populations with disparate intra- and inter-population coupling strengths. We explore the effects of heterogeneous coupling phase-lags between the two populations. Such heterogeneity arises naturally in various settings, for example, as an approximation to transmission delays, excitatory-inhibitory interactions, or as amplitude and phase responses of oscillators with electrical or mechanical coupling. We find that breaking the phase-lag symmetry results in a variety of states with uniform and non-uniform synchronization, including in-phase and anti-phase synchrony, full incoherence (splay state), chimera states with phase separation of 0 or π between populations, and states where both populations remain desynchronized. These desynchronized states exhibit stable, oscillatory, and even chaotic dynamics. Moreover, we identify the bifurcations through which chimeras emerge. Stable chimera states and desynchronized solutions, which do not arise for homogeneous phase-lag parameters, emerge as a result of competition between synchronized in-phase, anti-phase equilibria, and fully incoherent states when the phase-lags are near ±π2 (cosine coupling). These findings elucidate previous experimental results involving a network of mechanical oscillators and provide further insight into the breakdown of synchrony in biological systems.

  13. Anomalous drift of spiral waves in heterogeneous excitable media

    CERN Document Server

    Sridhar, S; Panfilov, Alexander V

    2009-01-01

    We study the drift of spiral waves in a simple model of heterogeneous excitable medium, having gradients in local excitability or cellular coupling. For the first time, we report the anomalous drift of spiral waves towards regions having higher excitability, in contrast to all earlier observations in reaction-diffusion models of excitable media. Such anomalous drift can promote the onset of complex spatio-temporal patterns, e.g., those responsible for life-threatening arrhythmias in the heart.

  14. Dealing with spatial heterogeneity

    Science.gov (United States)

    Marsily, Gh.; Delay, F.; Gonçalvès, J.; Renard, Ph.; Teles, V.; Violette, S.

    2005-03-01

    Heterogeneity can be dealt with by defining homogeneous equivalent properties, known as averaging, or by trying to describe the spatial variability of the rock properties from geologic observations and local measurements. The techniques available for these descriptions are mostly continuous Geostatistical models, or discontinuous facies models such as the Boolean, Indicator or Gaussian-Threshold models and the Markov chain model. These facies models are better suited to treating issues of rock strata connectivity, e.g. buried high permeability channels or low permeability barriers, which greatly affect flow and, above all, transport in aquifers. Genetic models provide new ways to incorporate more geology into the facies description, an approach that has been well developed in the oil industry, but not enough in hydrogeology. The conclusion is that future work should be focused on improving the facies models, comparing them, and designing new in situ testing procedures (including geophysics) that would help identify the facies geometry and properties. A world-wide catalog of aquifer facies geometry and properties, which could combine site genesis and description with methods used to assess the system, would be of great value for practical applications. On peut aborder le problème de l'hétérogénéité en s'efforçant de définir une perméabilité équivalente homogène, par prise de moyenne, ou au contraire en décrivant la variation dans l'espace des propriétés des roches à partir des observations géologiques et des mesures locales. Les techniques disponibles pour une telle description sont soit continues, comme l'approche Géostatistique, soit discontinues, comme les modèles de faciès, Booléens, ou bien par Indicatrices ou Gaussiennes Seuillées, ou enfin Markoviens. Ces modèles de faciès sont mieux capables de prendre en compte la connectivité des strates géologiques, telles que les chenaux enfouis à forte perméabilité, ou au contraire les faci

  15. Semantic Information Retrieval from Distributed Heterogeneous Data Sources

    CERN Document Server

    Munir, K; McClatchey, R; Khan, S; Habib, I

    2007-01-01

    Information retrieval from distributed heterogeneous data sources remains a challenging issue. As the number of data sources increases more intelligent retrieval techniques, focusing on information content and semantics, are required. Currently ontologies are being widely used for managing semantic knowledge, especially in the field of bioinformatics. In this paper we describe an ontology assisted system that allows users to query distributed heterogeneous data sources by hiding details like location, information structure, access pattern and semantic structure of the data. Our goal is to provide an integrated view on biomedical information sources for the Health-e-Child project with the aim to overcome the lack of sufficient semantic-based reformulation techniques for querying distributed data sources. In particular, this paper examines the problem of query reformulation across biomedical data sources, based on merged ontologies and the underlying heterogeneous descriptions of the respective data sources.

  16. Effect of Upper Mantle Heterogeneities on Lithosphere Stresses and Topography

    Science.gov (United States)

    Osei Tutu, A.; Steinberger, B.; Rogozhina, I.; Sobolev, S. V.

    2016-12-01

    The orientation and magnitude of lithosphere stresses give us knowledge about most of the processes within the Earth that are not easy to observe. It has been established (Steinberger, Schmeling, and Marquart 2001) that large contribution of the forces producing lithosphere stresses have their source origination from the buoyancies of both the upper and lower mantle acting beneath the lithosphere. The contribution of the crustal thickness to the stresses has been estimated to be less than 10% (Steinberger et al. 2001) in most region and increases in areas with high gravitational potential energy like the Himalayas. In most of these studies, the effect of the crust was determined separately by computing the gravitational potential energy from the crust (Ghosh et al. 2013) and applied as correction. (Artyushkov 1973) showed that the inhomogeneous nature of the crust contribute to the stresses observed as against using constant lithosphere thickness in most studies, due to the complexities for implementing a variable lithosphere. We seek extend the approach of Ghosh et al. (2013) by coupling the Crust 1.0 (Laske et al. 2013) to a varaible lithosphere thickness in our numerical method. Using a 3D global lithosphere-asthenosphere model (Popov and Sobolev 2008) with visco-elasto-plastic rheology, coupled at 300 km depth to a mantle modeled with a spectral technique (Hager and O'Connell, 1981), we compute lithosphere stresses and topography. we compare our model with observations; the World Stress Map, Global Strain Rate Map and the observed topgraphy. We use S40RTS seismic tomography below 300 km depth, with radial viscosity distribution (Steinberger et al 2006). To account for all the heterogeneities in the upper mantle (300 km) we used different 3D temperatures models setups. The first model is the thermal lithosphere model (Artemieva and Mooney, 2001) in continental regions and assumes half-space cooling of sea floor with age (Müller et al. 2008) for oceans. For the

  17. Imaging plants dynamics in heterogenic environments.

    Science.gov (United States)

    Fiorani, Fabio; Rascher, Uwe; Jahnke, Siegfried; Schurr, Ulrich

    2012-04-01

    Noninvasive imaging sensors and computer vision approaches are key technologies to quantify plant structure, physiological status, and performance. Today, imaging sensors exploit a wide range of the electromagnetic spectrum, and they can be deployed to measure a growing number of traits, also in heterogenic environments. Recent advances include the possibility to acquire high-resolution spectra by imaging spectroscopy and classify signatures that might be informative of plant development, nutrition, health, and disease. Three-dimensional (3D) reconstruction of surfaces and volume is of particular interest, enabling functional and mechanistic analyses. While taking pictures is relatively easy, quantitative interpretation often remains challenging and requires integrating knowledge of sensor physics, image analysis, and complex traits characterizing plant phenotypes.

  18. Organizational heterogeneity of vertebrate genomes.

    Directory of Open Access Journals (Sweden)

    Svetlana Frenkel

    Full Text Available Genomes of higher eukaryotes are mosaics of segments with various structural, functional, and evolutionary properties. The availability of whole-genome sequences allows the investigation of their structure as "texts" using different statistical and computational methods. One such method, referred to as Compositional Spectra (CS analysis, is based on scoring the occurrences of fixed-length oligonucleotides (k-mers in the target DNA sequence. CS analysis allows generating species- or region-specific characteristics of the genome, regardless of their length and the presence of coding DNA. In this study, we consider the heterogeneity of vertebrate genomes as a joint effect of regional variation in sequence organization superimposed on the differences in nucleotide composition. We estimated compositional and organizational heterogeneity of genome and chromosome sequences separately and found that both heterogeneity types vary widely among genomes as well as among chromosomes in all investigated taxonomic groups. The high correspondence of heterogeneity scores obtained on three genome fractions, coding, repetitive, and the remaining part of the noncoding DNA (the genome dark matter--GDM allows the assumption that CS-heterogeneity may have functional relevance to genome regulation. Of special interest for such interpretation is the fact that natural GDM sequences display the highest deviation from the corresponding reshuffled sequences.

  19. Organizational heterogeneity of vertebrate genomes.

    Science.gov (United States)

    Frenkel, Svetlana; Kirzhner, Valery; Korol, Abraham

    2012-01-01

    Genomes of higher eukaryotes are mosaics of segments with various structural, functional, and evolutionary properties. The availability of whole-genome sequences allows the investigation of their structure as "texts" using different statistical and computational methods. One such method, referred to as Compositional Spectra (CS) analysis, is based on scoring the occurrences of fixed-length oligonucleotides (k-mers) in the target DNA sequence. CS analysis allows generating species- or region-specific characteristics of the genome, regardless of their length and the presence of coding DNA. In this study, we consider the heterogeneity of vertebrate genomes as a joint effect of regional variation in sequence organization superimposed on the differences in nucleotide composition. We estimated compositional and organizational heterogeneity of genome and chromosome sequences separately and found that both heterogeneity types vary widely among genomes as well as among chromosomes in all investigated taxonomic groups. The high correspondence of heterogeneity scores obtained on three genome fractions, coding, repetitive, and the remaining part of the noncoding DNA (the genome dark matter--GDM) allows the assumption that CS-heterogeneity may have functional relevance to genome regulation. Of special interest for such interpretation is the fact that natural GDM sequences display the highest deviation from the corresponding reshuffled sequences.

  20. Reaction Selectivity in Heterogeneous Catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Somorjai, Gabor A.; Kliewer, Christopher J.

    2009-02-02

    The understanding of selectivity in heterogeneous catalysis is of paramount importance to our society today. In this review we outline the current state of the art in research on selectivity in heterogeneous catalysis. Current in-situ surface science techniques have revealed several important features of catalytic selectivity. Sum frequency generation vibrational spectroscopy has shown us the importance of understanding the reaction intermediates and mechanism of a heterogeneous reaction, and can readily yield information as to the effect of temperature, pressure, catalyst geometry, surface promoters, and catalyst composition on the reaction mechanism. DFT calculations are quickly approaching the ability to assist in the interpretation of observed surface spectra, thereby making surface spectroscopy an even more powerful tool. HP-STM has revealed three vitally important parameters in heterogeneous selectivity: adsorbate mobility, catalyst mobility, and selective site-blocking. The development of size controlled nanoparticles from 0.8 to 10 nm, of controlled shape, and of controlled bimetallic composition has revealed several important variables for catalytic selectivity. Lastly, DFT calculations may be paving the way to guiding the composition choice for multi-metallic heterogeneous catalysis for the intelligent design of catalysts incorporating the many factors of selectivity we have learned.

  1. Micro-heterogeneity metrics for diffusion in soft matter.

    Science.gov (United States)

    Mellnik, John; Vasquez, Paula A; McKinley, Scott A; Witten, Jacob; Hill, David B; Forest, M Gregory

    2014-10-21

    Passive particle tracking of diffusive paths in soft matter, coupled with analysis of the path data, is firmly established as a fundamental methodology for characterization of both diffusive transport properties (the focus here) and linear viscoelasticity. For either focus, particle time series are typically analyzed by ensemble averaging over paths, a perfectly natural protocol for homogeneous materials or for applications where mean properties are sufficient. Many biological materials, however, are heterogeneous over length scales above the probe diameter, and the implications of heterogeneity for biologically relevant transport properties (e.g. diffusive passage times through a complex fluid layer) motivate this paper. Our goals are three-fold: first, to detect heterogeneity as reflected by the ensemble path data; second, to further decompose the ensemble of particle paths into statistically distinct clusters; and third, to fit the path data in each cluster to a model for the underlying stochastic process. After reviewing current best practices for detection and assessment of heterogeneity in diffusive processes, we introduce our strategy toward the first two goals with methods from the statistics and machine learning literature that have not found application thus far to passive particle tracking data. We apply an analysis based solely on the path data that detects heterogeneity and yields a decomposition of particle paths into statistically distinct clusters. After these two goals are achieved, one can then pursue model-fitting. We illustrate these heterogeneity metrics on diverse datasets: for numerically generated and experimental particle paths, with tunable and unknown heterogeneity, on numerical models for simple diffusion and anomalous sub-diffusion, and experimentally on sucrose, hyaluronic acid, agarose, and human lung culture mucus solutions.

  2. Sound knowledge

    DEFF Research Database (Denmark)

    Kauffmann, Lene Teglhus

    at different bureaucratic levels and among researchers in university departments and research institutes. Researchers had a range of disciplinary backgrounds, in anthropology, sociology, public health, education and health economy, all bringing different ideas about the construction of knowledge to health...... promotion. These actors shared a working style formed by ‘reflexivity’, implying thoughtful considerations on a broad range of factors relevant for decisions in policymaking as well as in research. I suggest that this reflexivity is based in an academic culture that has crept into policymaking as a result...

  3. Heterogeneous Baylis-Hillman using a polystyrene-bound 4-(N-benzyl-N-methylamino)pyridine as reusable catalyst.

    Science.gov (United States)

    Corma, Avelino; García, Hermenegildo; Leyva, Antonio

    2003-11-21

    An insoluble Merrifield type resin having 4-aminopyridine units is a suitable and reusable heterogeneous catalyst for the Baylis-Hillman coupling of aromatic aldehydes and alpha,beta-unsaturated ketones.

  4. Heterogeneity in Preferences and Productivity

    DEFF Research Database (Denmark)

    Gørtz, Mette

    choices of expenditure, household production and leisure for people in and around retirement. The unobserved individual heterogeneity factor is isolated by comparing cross-sectional evidence and panel data estimates of the effects of retirement on consumption and time allocation. Based on cross......-section data, we can identify a difference in consumption due to retirement status, but when the panel nature of the data is exploited, the effect of retirement on consumption is small and insignificant. Moreover, the analyses point at a large positive effect of retirement on household production. Our results......This paper discusses the determinants of the retirement decision and the implications of retirement on economic well-being. The main contribution of the paper is to formulate the role of individual heterogeneity explicitly. We argue that individual heterogeneity in 1) productivity of market work...

  5. A multilingual programming model for coupled systems.

    Energy Technology Data Exchange (ETDEWEB)

    Ong, E. T.; Larson, J. W.; Norris, B.; Tobis, M.; Steder, M.; Jacob, R. L.; Mathematics and Computer Science; Univ. of Wisconsin; Univ. of Chicago; The Australian National Univ.

    2008-01-01

    Multiphysics and multiscale simulation systems share a common software requirement-infrastructure to implement data exchanges between their constituent parts-often called the coupling problem. On distributed-memory parallel platforms, the coupling problem is complicated by the need to describe, transfer, and transform distributed data, known as the parallel coupling problem. Parallel coupling is emerging as a new grand challenge in computational science as scientists attempt to build multiscale and multiphysics systems on parallel platforms. An additional coupling problem in these systems is language interoperability between their constituent codes. We have created a multilingual parallel coupling programming model based on a successful open-source parallel coupling library, the Model Coupling Toolkit (MCT). This programming model's capabilities reach beyond MCT's native Fortran implementation to include bindings for the C++ and Python programming languages. We describe the method used to generate the interlanguage bindings. This approach enables an object-based programming model for implementing parallel couplings in non-Fortran coupled systems and in systems with language heterogeneity. We describe the C++ and Python versions of the MCT programming model and provide short examples. We report preliminary performance results for the MCT interpolation benchmark. We describe a major Python application that uses the MCT Python bindings, a Python implementation of the control and coupling infrastructure for the community climate system model. We conclude with a discussion of the significance of this work to productivity computing in multidisciplinary computational science.

  6. Dynamic fracture of heterogeneous materials

    Energy Technology Data Exchange (ETDEWEB)

    Stout, M.G.; Liu, C.; Addessio, F.L.; Williams, T.O.; Bennett, J.G.; Haberman, K.S.; Asay, B.W.

    1998-12-31

    This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The objective of this project was to investigate the fundamental aspects of the process of dynamic fracture propagation in heterogeneous materials. The work focused on three important, but poorly understood, aspects of dynamic fracture for materials with a heterogeneous microstructure. These were: the appropriateness of using a single-parameter asymptotic analysis to describe dynamic crack-tip deformation fields, the temperature rises at the tip and on the flanks of a running crack, and the constitutive modeling of damage initiation and accumulation.

  7. Job Heterogeneity and Coordination Frictions

    DEFF Research Database (Denmark)

    Kennes, John; le Maire, Daniel

    the job ladder, how the identification of assortative matching is fundamentally different in directed and undirected search models, how our theory accounts for business cycle facts related to inter-temporal changes in job offer distributions, and how our model could also be used to identify......We develop a new directed search model of a frictional labor market with a continuum of heterogenous workers and firms. We estimate two versions of the model - auction and price posting - using Danish data on wages and productivities. Assuming heterogenous workers with no comparative advantage, we...

  8. Feedbacks between hydrological heterogeneity and bioremediation induced biogeochemical transformations

    Energy Technology Data Exchange (ETDEWEB)

    Englert, A.; Hubbard, S.S.; Williams, K.H.; Li, L.; Steefel, C.I.

    2009-04-15

    For guiding optimal design and interpretation of in-situ treatments that strongly perturb subsurface systems, knowledge about the spatial and temporal patterns of mass transport and reaction intensities are important. Here, a procedure was developed and applied to time-lapse concentrations of a conservative tracer (bromide), an injected amendment (acetate) and reactive species (iron(II), uranium(VI) and sulfate) associated with two field scale biostimulation experiments, which were conducted successively at the same field location over two years. The procedure is based on a temporal moment analysis approach that relies on a streamtube approximation. The study shows that biostimulated reactions can be considerably influenced by subsurface hydrological and geochemical heterogeneities: the delivery of bromide and acetate and the intensity of the sulfate reduction is interpreted to be predominantly driven by the hydrological heterogeneity, while the intensity of the iron reduction is interpreted to be primarily controlled by the geochemical heterogeneity. The intensity of the uranium(VI) reduction appears to be impacted by both the hydrological and geochemical heterogeneity. Finally, the study documents the existence of feedbacks between hydrological heterogeneity and remediation-induced biogeochemical transformations at the field scale, particularly the development of precipitates that may cause clogging and flow rerouting.

  9. A knowledge discovery object model API for Java

    Directory of Open Access Journals (Sweden)

    Jones Steven JM

    2003-10-01

    Full Text Available Abstract Background Biological data resources have become heterogeneous and derive from multiple sources. This introduces challenges in the management and utilization of this data in software development. Although efforts are underway to create a standard format for the transmission and storage of biological data, this objective has yet to be fully realized. Results This work describes an application programming interface (API that provides a framework for developing an effective biological knowledge ontology for Java-based software projects. The API provides a robust framework for the data acquisition and management needs of an ontology implementation. In addition, the API contains classes to assist in creating GUIs to represent this data visually. Conclusions The Knowledge Discovery Object Model (KDOM API is particularly useful for medium to large applications, or for a number of smaller software projects with common characteristics or objectives. KDOM can be coupled effectively with other biologically relevant APIs and classes. Source code, libraries, documentation and examples are available at http://www.bcgsc.ca/bioinfo/software.

  10. Knowledge Technology Applications for Knowledge Management

    OpenAIRE

    Andersson, Kent

    2000-01-01

    We investigate how the knowledge in knowledge technology applications for knowledge management can be represented to let the user directly manage the knowledge content of the applications. In paper I we design a representation of diagnosis knowledge that allows the user to add new components and inspect the function of the device. The representation allows an integration of model based knowledge with compiled and heuristic knowledge so that the device and its function can be represented a sui...

  11. Knowledge in Context

    Directory of Open Access Journals (Sweden)

    Nikola Kompa

    2014-04-01

    Full Text Available My aim in this paper is to motivate and defend a version of epistemic contextualism; a version, that is, of what came to be called attributor or ascriber contextualism. I will begin by outlining, in the first part, what I take to be the basic idea of and motivation behind the version of epistemic contextualism that I favor. In the second part, a couple of examples will be presented in order to illustrate the contextualist point. Since epistemic (ascriber contextualists commonly claim that knowledge ascriptions are context-sensitive, the third part of the paper will be concerned with the phenomenon of context-sensitivity at a more general level. A more detailed inquiry into the context-sensitivity natural language expressions exhibit will prove helpful in order to counter the objection that postulating context-sensitivity in the case of knowledge ascriptions is an ad-hoc-maneuver. Given that epistemic contextualism is partly an epistemological thesis, party a linguistic thesis, the remainder of the paper will be devoted to the question of how to semantically model the kind of context-sensitivity exhibited by knowledge ascriptions. The upshot will be that there are two differ-ent ways of semantically accommodating the context-sensitivity at issue. Both call for a more or less drastic departure from epistemological and semantic orthodoxy.

  12. Constructing Knowledge

    Science.gov (United States)

    Blanton, Patricia

    2003-02-01

    Schools are expected to lay the foundation upon which knowledge can be built and equip students with the tools necessary to accomplish the construction. The role of the teacher in this building process is crucial to the type of structure the student can build. Whether you call it constructivism, discussion teaching, project-based learning, inquiry learning, or any of the other names given to the instructional strategies being suggested by education researchers, the key is getting students to become active participants in the process. While some students may be able to learn from eloquently delivered lectures and dynamic demonstrations, the majority of students cannot effectively retain and apply ideas communicated in this manner.

  13. Wireless Internet on Heterogeneous Networks

    NARCIS (Netherlands)

    Wu, G.

    2001-01-01

    The wide proliferation of wireless systems and the use of software radio technologies enable the employment of a heterogeneous network. In this concept services are delivered via the network that is most efficient for that service. The solution is based on a common core network that interconnects ac

  14. Communicating to heterogeneous target groups

    DEFF Research Database (Denmark)

    Pedersen, Karsten

    very often have to communicate to rather heterogeneous target groups that have little more in common than a certain geographical habitat. That goes against most schoolbook teaching in the field of communication, but is none the less the terms with which that kind of communication has to live...

  15. Dynamic heterogeneity and life histories

    DEFF Research Database (Denmark)

    Tuljapurkar, Shripad; Steiner, Uli

    2010-01-01

    of the variation among individual characteristics that is generated by dynamic heterogeneity. We conclude by discussing our ongoing and planned work on animals and humans. We also discuss the connections between our work and recent work on human mortality, disability and health, and life course theory....

  16. Social Capital and Community Heterogeneity

    Science.gov (United States)

    Coffe, Hilde

    2009-01-01

    Recent findings indicate that more pronounced community heterogeneity is associated with lower levels of social capital. These studies, however, concentrate on specific aspects in which people differ (such as income inequality or ethnic diversity). In the present paper, we introduce the number of parties in the local party system as a more…

  17. Social capital and community heterogeneity

    NARCIS (Netherlands)

    Coffé, Hilde R.

    2009-01-01

    Abstract Recent findings indicate that more pronounced community heterogeneity is associated with lower levels of social capital. These studies, however, concentrate on specific aspects in which people differ (such as income inequality or ethnic diversity). In the present paper, we introduce the

  18. Prices and heterogeneous search costs

    NARCIS (Netherlands)

    Luis Moraga-Gonzalez, Jose; Sandor, Zsolt; Wildenbeest, Matthijs R.

    2017-01-01

    We study price formation in a model of consumer search for differentiated products in which consumers have heterogeneous search costs. We provide conditions under which a pure-strategy symmetric Nash equilibrium exists and is unique. Search costs affect two margins-the intensive search margin (or se

  19. Formation of Rationally Heterogeneous Expectations

    NARCIS (Netherlands)

    Pfajfar, D.

    2012-01-01

    Abstract: This paper models expectation formation by taking into account that agents produce heterogeneous expectations due to model uncertainty, informational frictions and different capacities for processing information. We show that there are two general classes of steady states within this frame

  20. Heterogeneous catalysis through microcontact printing

    NARCIS (Netherlands)

    Spruell, Jason M.; Sheriff, Bonnie A.; Rozkiewicz, D.I.; Dichtel, William R.; Rohde, Rosemary D.; Reinhoudt, David; Stoddart, Fraser; Heath, James R.

    2008-01-01

    Minting a Stamp: The preparation of copper metal-coated elastomeric stamps and their use in catalyzing the Cu-catalyzed azide-alkyne cycloaddition reaction heterogeneously through microcontact printing is described. This StampCat process is compared to other conventional surface-functionalization te

  1. REPLIKASI UNIDIRECTIONAL PADA HETEROGEN DATABASE

    Directory of Open Access Journals (Sweden)

    Hendro Nindito

    2013-11-01

    where development can be done quickly and testing of working models of the interaction process is done through repeated. From this research it is obtained that the database replication technology using Oracle Golden Gate can be applied in heterogeneous environments in real time as well.

  2. Surface science of heterogeneous reactions.

    Science.gov (United States)

    White, J M

    1982-10-29

    Some of the present and future directions for surface science as a growing and naturally interdisciplinary subject are reviewed. Particular attention is given to surface reaction chemistry as it is related to heterogenous catalysis, a subject area where there are abundant opportunities for detailed measurements of structure and dynamics at the molecular level.

  3. Measuring and predicting heterogeneous recessions

    NARCIS (Netherlands)

    C. Cakmakli; R. Paap; D. van Dijk

    2011-01-01

    This paper conducts an empirical analysis of the heterogeneity of recessions in monthly U.S. coincident and leading indicator variables. Univariate Markovswitching models indicate that it is appropriate to allow for two distinct recession regimes, corresponding with ‘mild’ and ‘severe’ recessions. A

  4. Palladium-catalyzed coupling reactions

    CERN Document Server

    Molnár, Árpád

    2013-01-01

    This handbook and ready reference brings together all significant issues of practical importance for interested readers in one single volume. While covering homogeneous and heterogeneous catalysis, the text is unique in focusing on such important aspects as using different reaction media, microwave techniques or catalyst recycling. It also provides a comprehensive treatment of modern-day coupling reactions and emphasizes those topics that show potential for future development, such as continuous flow systems, water as a reaction medium, and catalyst immobilization, among others. With i

  5. Heterogeneous Photocatalytic Oxidation of Atmospheric Trace Contaminants

    Science.gov (United States)

    Ollis, David F.

    1996-01-01

    Heterogeneous photocatalysis involves the use of a light-activated catalyst at room temperature in order to carry out a desired reaction. In the presence of molecular oxygen, illumination of the n-type semiconductor oxide titanium dioxide (TiO2) provides for production of highly active forms of oxygen, such as hydroxyl radicals, which are able to carry out the complete oxidative destruction of simple hydrocarbons such as methane, ethane, ethylene, propylene, and carbon monoxide. This broad oxidation potential, coupled with the ability with sufficient residence time to achieve complete oxidation of simple hydrocarbon contaminants to carbon dioxide and water, indicated that heterogeneous photocatalysis should be examined for its potential for purification of spacecraft air. If a successful catalyst and photoreactor could be demonstrated at the laboratory level, such results would allow consideration of photocatalysts as a partial or complete replacement of adsorption systems, thereby allowing for reduction in lift-off weight of a portion of the life support system for the spacecraft, or other related application such as a space station or a conventional commercial aircraft. The present research was undertaken to explore this potential through achievement of the following plan of work: (a) ascertain the intrinsic kinetics of conversion of pollutants of interest in spacecraft, (b) ascertain the expected lifetime of catalysts through examination of most likely routes of catalyst deactivation and regeneration (c) model and explore experimentally the low pressure drop catalytic monolith, a commercial configuration for automotive exhaust control (d) examine the kinetics of multicomponent conversions. In the recent course of this work, we have also discovered how to increase catalyst activity via halide promotion which has allowed us to achieve approximately 100% conversion of an aromatic contaminant (toluene) in a very short residence time of 5-6 milliseconds.

  6. An exploration of knowledge integration problems in interdisciplinary research teams

    NARCIS (Netherlands)

    Bayerl, P.S.; Steinheider, B.

    2009-01-01

    The integration of function-specific expertise into a shared knowledge base is a crucial, but complex process for success in interdisciplinary teams. This paper presents an empirically derived typology of knowledge integration problems and links their occurrence to degree of heterogeneity and presen

  7. Optimizing working memory with heterogeneity of recurrent cortical excitation.

    Science.gov (United States)

    Kilpatrick, Zachary P; Ermentrout, Bard; Doiron, Brent

    2013-11-27

    A neural correlate of parametric working memory is a stimulus-specific rise in neuron firing rate that persists long after the stimulus is removed. Network models with local excitation and broad inhibition support persistent neural activity, linking network architecture and parametric working memory. Cortical neurons receive noisy input fluctuations that cause persistent activity to diffusively wander about the network, degrading memory over time. We explore how cortical architecture that supports parametric working memory affects the diffusion of persistent neural activity. Studying both a spiking network and a simplified potential well model, we show that spatially heterogeneous excitatory coupling stabilizes a discrete number of persistent states, reducing the diffusion of persistent activity over the network. However, heterogeneous coupling also coarse-grains the stimulus representation space, limiting the storage capacity of parametric working memory. The storage errors due to coarse-graining and diffusion trade off so that information transfer between the initial and recalled stimulus is optimized at a fixed network heterogeneity. For sufficiently long delay times, the optimal number of attractors is less than the number of possible stimuli, suggesting that memory networks can under-represent stimulus space to optimize performance. Our results clearly demonstrate the combined effects of network architecture and stochastic fluctuations on parametric memory storage.

  8. Modeling meander morphodynamics over self-formed heterogeneous floodplains

    Science.gov (United States)

    Bogoni, Manuel; Putti, Mario; Lanzoni, Stefano

    2017-06-01

    This work addresses the signatures embedded in the planform geometry of meandering rivers consequent to the formation of floodplain heterogeneities as the river bends migrate. Two geomorphic features are specifically considered: scroll bars produced by lateral accretion of point bars at convex banks and oxbow lake fills consequent to neck cutoffs. The sedimentary architecture of these geomorphic units depends on the type and amount of sediment, and controls bank erodibility as the river impinges on them, favoring or contrasting the river migration. The geometry of numerically generated planforms obtained for different scenarios of floodplain heterogeneity is compared to that of natural meandering paths. Half meander metrics and spatial distribution of channel curvatures are used to disclose the complexity embedded in meandering geometry. Fourier Analysis, Principal Component Analysis, Singular Spectrum Analysis and Multivariate Singular Spectrum Analysis are used to emphasize the subtle but crucial differences which may emerge between apparently similar configurations. A closer similarity between observed and simulated planforms is attained when fully coupling flow and sediment dynamics (fully-coupled models) and when considering self-formed heterogeneities that are less erodible than the surrounding floodplain.

  9. Knowledge Management: An Introduction.

    Science.gov (United States)

    Mac Morrow, Noreen

    2001-01-01

    Discusses issues related to knowledge management and organizational knowledge. Highlights include types of knowledge; the knowledge economy; intellectual capital; knowledge and learning organizations; knowledge management strategies and processes; organizational culture; the role of technology; measuring knowledge; and the role of the information…

  10. Preliminary Investigations of Challenges in Dynamic Integration of Heterogeneous Services

    Directory of Open Access Journals (Sweden)

    Makaziwe Makamba

    2016-02-01

    Full Text Available The progress of technology prompted the proliferation of services. Services are distinct, loosely coupled units of functionalities that are self-contained. These services are however developed by various vendors without following appropriate standards. However, the need for interoperability and reusability prompts the need for service integration. Service integration is not a new arena but emphasis is mostly on homogeneous services. However, the challenge lies on the integration of heterogeneous services to enforce reusability and maximize Total Cost of Deployment (TCD and Total Cost of Ownership (TCO at organization level. The issue of service integration has become critical, due to the increase of these diverse services as they have different platforms, architecture and use different programming languages. The current methods of integrating heterogeneous services are manual integration methods. Therefore, the challenge with the current methods is time consumption, lack of flexibility, cost (TCO and TCD, total time to development, because the process is manual. In this paper, we explore the challenges regarding dynamic integration of heterogeneous services and identify key issues that need to be addressed, in order to develop a successful mechanism that will enable dynamic integration of heterogeneous services.

  11. Homogeneous and heterogenized iridium water oxidation catalysts

    Science.gov (United States)

    Macchioni, Alceo

    2014-10-01

    The development of an efficient catalyst for the oxidative splitting of water into molecular oxygen, protons and electrons is of key importance for producing solar fuels through artificial photosynthesis. We are facing the problem by means of a rational approach aimed at understanding how catalytic performance may be optimized by the knowledge of the reaction mechanism of water oxidation and the fate of the catalytic site under the inevitably harsh oxidative conditions. For the purposes of our study we selected iridium water oxidation catalysts, exhibiting remarkable performance (TOF > 5 s-1 and TON > 20000). In particular, we recently focused our attention on [Cp*Ir(N,O)X] (N,O = 2-pyridincarboxylate; X = Cl or NO3) and [IrCl(Hedta)]Na water oxidation catalysts. The former exhibited a remarkable TOF whereas the latter showed a very high TON. Furthermore, [IrCl(Hedta)]Na was heterogenized onto TiO2 taking advantage of the presence of a dandling -COOH functionality. The heterogenized catalyst maintained approximately the same catalytic activity of the homogeneous analogous with the advantage that could be reused many times. Mechanistic studies were performed in order to shed some light on the rate-determining step and the transformation of catalysts when exposed to "oxidative stress". It was found that the last oxidative step, preceding oxygen liberation, is the rate-determining step when a small excess of sacrificial oxidant is used. In addition, several intermediates of the oxidative transformation of the catalyst were intercepted and characterized by NMR, X-Ray diffractometry and ESI-MS.

  12. Replikasi Unidirectional pada Heterogen Database

    Directory of Open Access Journals (Sweden)

    Hendro Nindito

    2013-12-01

    Full Text Available The use of diverse database technology in enterprise today can not be avoided. Thus, technology is needed to generate information in real time. The purpose of this research is to discuss a database replication technology that can be applied in heterogeneous database environments. In this study we use Windows-based MS SQL Server database to Linux-based Oracle database as the goal. The research method used is prototyping where development can be done quickly and testing of working models of the interaction process is done through repeated. From this research it is obtained that the database replication technolgy using Oracle Golden Gate can be applied in heterogeneous environments in real time as well.

  13. Seepage Anisotropy of Heterogeneous Body

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Ore dumps are heterogeneous bodies with anisotropic seepage characteristics because of the ore segregation.In an indoor experiment, a dump was constructed with three strata, where the horizontal and vertical seepage experiments were carried out.Horizontals flow are regarded as phreatic plan flows without penetration.Its seepage law satifies the Dupuit equation.With parallel lay seepage model, the equivalent seepage coefficient in the horizontal flow was obtained and was equivalent to the weighted mean of the seepage coefficient of each stratum.An unsaturated flow appeared in the vertical experiment, with a hydraulic gradient of 1.The vertical flow was equivalent to the seepage model that moved in vertical bedding; its equivalent seepage coefficient depended on the stratum with the minimum seepage coefficient.That the experiment showed clear anisotropy in a heterogeneous body was obvious with an anisotropic coefficient between 63 and 155, which is 25 to 100 times larger than that of a homogeneous body.

  14. Biodiesel production using heterogeneous catalysts.

    Science.gov (United States)

    Semwal, Surbhi; Arora, Ajay K; Badoni, Rajendra P; Tuli, Deepak K

    2011-02-01

    The production and use of biodiesel has seen a quantum jump in the recent past due to benefits associated with its ability to mitigate greenhouse gas (GHG). There are large number of commercial plants producing biodiesel by transesterification of vegetable oils and fats based on base catalyzed (caustic) homogeneous transesterification of oils. However, homogeneous process needs steps of glycerol separation, washings, very stringent and extremely low limits of Na, K, glycerides and moisture limits in biodiesel. Heterogeneous catalyzed production of biodiesel has emerged as a preferred route as it is environmentally benign needs no water washing and product separation is much easier. The present report is review of the progress made in development of heterogeneous catalysts suitable for biodiesel production. This review shall help in selection of suitable catalysts and the optimum conditions for biodiesel production.

  15. DATABASE REPLICATION IN HETEROGENOUS PLATFORM

    Directory of Open Access Journals (Sweden)

    Hendro Nindito

    2014-01-01

    Full Text Available The application of diverse database technologies in enterprises today is increasingly a common practice. To provide high availability and survavibality of real-time information, a database replication technology that has capability to replicate databases under heterogenous platforms is required. The purpose of this research is to find the technology with such capability. In this research, the data source is stored in MSSQL database server running on Windows. The data will be replicated to MySQL running on Linux as the destination. The method applied in this research is prototyping in which the processes of development and testing can be done interactively and repeatedly. The key result of this research is that the replication technology applied, which is called Oracle GoldenGate, can successfully manage to do its task in replicating data in real-time and heterogeneous platforms.

  16. Harvesting geographic features from heterogeneous raster maps

    Science.gov (United States)

    Chiang, Yao-Yi

    2010-11-01

    Raster maps offer a great deal of geospatial information and are easily accessible compared to other geospatial data. However, harvesting geographic features locked in heterogeneous raster maps to obtain the geospatial information is challenging. This is because of the varying image quality of raster maps (e.g., scanned maps with poor image quality and computer-generated maps with good image quality), the overlapping geographic features in maps, and the typical lack of metadata (e.g., map geocoordinates, map source, and original vector data). Previous work on map processing is typically limited to a specific type of map and often relies on intensive manual work. In contrast, this thesis investigates a general approach that does not rely on any prior knowledge and requires minimal user effort to process heterogeneous raster maps. This approach includes automatic and supervised techniques to process raster maps for separating individual layers of geographic features from the maps and recognizing geographic features in the separated layers (i.e., detecting road intersections, generating and vectorizing road geometry, and recognizing text labels). The automatic technique eliminates user intervention by exploiting common map properties of how road lines and text labels are drawn in raster maps. For example, the road lines are elongated linear objects and the characters are small connected-objects. The supervised technique utilizes labels of road and text areas to handle complex raster maps, or maps with poor image quality, and can process a variety of raster maps with minimal user input. The results show that the general approach can handle raster maps with varying map complexity, color usage, and image quality. By matching extracted road intersections to another geospatial dataset, we can identify the geocoordinates of a raster map and further align the raster map, separated feature layers from the map, and recognized features from the layers with the geospatial

  17. Temporal fate mapping reveals age-linked heterogeneity in naive T lymphocytes in mice

    OpenAIRE

    Hogan, T.; Gossel, G.; Yates, A. J.; Seddon, B

    2015-01-01

    Understanding how our T-cell compartments are maintained requires knowledge of their population dynamics, which are typically quantified over days to weeks using the administration of labels incorporated into the DNA of dividing cells. These studies present snapshots of homeostatic dynamics and have suggested that lymphocyte populations are heterogeneous with respect to rates of division and/or death, although resolving the details of such heterogeneity is problematic. Here we present a metho...

  18. Surface fluxes in heterogeneous landscape

    Energy Technology Data Exchange (ETDEWEB)

    Bay Hasager, C.

    1997-01-01

    The surface fluxes in homogeneous landscapes are calculated by similarity scaling principles. The methodology is well establish. In heterogeneous landscapes with spatial changes in the micro scale range, i e from 100 m to 10 km, advective effects are significant. The present work focus on these effects in an agricultural countryside typical for the midlatitudes. Meteorological and satellite data from a highly heterogeneous landscape in the Rhine Valley, Germany was collected in the large-scale field experiment TRACT (Transport of pollutants over complex terrain) in 1992. Classified satellite images, Landsat TM and ERS SAR, are used as basis for roughness maps. The roughnesses were measured at meteorological masts in the various cover classes and assigned pixel by pixel to the images. The roughness maps are aggregated, i e spatially averaged, into so-called effective roughness lengths. This calculation is performed by a micro scale aggregation model. The model solves the linearized atmospheric flow equations by a numerical (Fast Fourier Transform) method. This model also calculate maps of friction velocity and momentum flux pixel wise in heterogeneous landscapes. It is indicated how the aggregation methodology can be used to calculate the heat fluxes based on the relevant satellite data i e temperature and soil moisture information. (au) 10 tabs., 49 ills., 223 refs.

  19. Analyzing and modeling heterogeneous behavior

    Science.gov (United States)

    Lin, Zhiting; Wu, Xiaoqing; He, Dongyue; Zhu, Qiang; Ni, Jixiang

    2016-05-01

    Recently, it was pointed out that the non-Poisson statistics with heavy tail existed in many scenarios of human behaviors. But most of these studies claimed that power-law characterized diverse aspects of human mobility patterns. In this paper, we suggest that human behavior may not be driven by identical mechanisms and can be modeled as a Semi-Markov Modulated Process. To verify our suggestion and model, we analyzed a total of 1,619,934 records of library visitations (including undergraduate and graduate students). It is found that the distribution of visitation intervals is well fitted with three sections of lines instead of the traditional power law distribution in log-log scale. The results confirm that some human behaviors cannot be simply expressed as power law or any other simple functions. At the same time, we divided the data into groups and extracted period bursty events. Through careful analysis in different groups, we drew a conclusion that aggregate behavior might be composed of heterogeneous behaviors, and even the behaviors of the same type tended to be different in different period. The aggregate behavior is supposed to be formed by "heterogeneous groups". We performed a series of experiments. Simulation results showed that we just needed to set up two states Semi-Markov Modulated Process to construct proper representation of heterogeneous behavior.

  20. Heterogeneity in the multiple myeloma tumor clone

    NARCIS (Netherlands)

    Guikema, JEJ; Hovenga, S; Vellenga, E; Bos, NA

    2004-01-01

    Multiple Myeloma ( MM) is a plasma cell malignancy which is characterized by a very heterogeneous disease outcome. Heterogeneity in plasma cell characteristics, including morphology, maturation status, immunophenotype and genetic abnormalities partly account for the variable disease outcome. Althoug

  1. Heterogeneity in the multiple myeloma tumor clone

    NARCIS (Netherlands)

    Guikema, JEJ; Hovenga, S; Vellenga, E; Bos, NA

    Multiple Myeloma ( MM) is a plasma cell malignancy which is characterized by a very heterogeneous disease outcome. Heterogeneity in plasma cell characteristics, including morphology, maturation status, immunophenotype and genetic abnormalities partly account for the variable disease outcome.

  2. The Migration and Entrapment of DNAPLs in Physically and Chemically Heterogeneous Porous Media - Final Report - 09/15/1996 - 09/15/2000

    Energy Technology Data Exchange (ETDEWEB)

    Abriola, L. M.; Demond, A. H.

    2000-09-15

    Hazardous dense nonaqueous phase liquids (DNAPLs), such as chlorinated solvents, are slightly water soluble and pose a serious threat to soil and groundwater supplies in many portions of the United States. The migration and entrapment of DNAPLs in the subsurface environment is typically believed to be controlled by physical heterogeneities; i.e, layers and lenses of contrasting soil texture. The rationale for this assumption is that capillarity, as determined by the soil texture, is the dominant transport mechanism. Capillarity also depends on interfacial tension and medium wettability. Interfacial tension and medium wettability may be spatially and temporally dependent due to variations in aqueous phase chemistry, contaminant aging, and/or variations in mineralogy and organic matter distributions. Such chemical heterogeneities have largely been ignored to date, even though they are known to have dramatic effects on the hydraulic property relations. Numerical multiphase flow and transport models typically assume that solids are water-wet and that interfacial tension is constant. The primary objective of this research is to investigate the influence of coupled physical and chemical heterogeneities on the migration and entrapment of DNAPLs. This objective will be accomplished through a combination of laboratory and numerical experiments. Laboratory experiments will be conducted to examine: (i) aqueous phase chemistry effects on medium wettability and interfacial tension; and (ii) relative permeability-saturation-capillary pressure relations for chemically heterogeneous systems. An important objective of this research is to modify a two-dimensional multiphase flow and transport model to account for chemically and physically heterogeneous systems. This numerical simulator will be used in conjunction with independently measured parameters to simulate two-dimensional DNAPL infiltration experiments. Comparisons of simulated and laboratory data will provide a means to

  3. Molecular heterogeneity in glioblastoma: potential clinical implications

    Directory of Open Access Journals (Sweden)

    Nicole Renee Parker

    2015-03-01

    Full Text Available Glioblastomas, (grade 4 astrocytomas, are aggressive primary brain tumors characterized by histopathological heterogeneity. High resolution sequencing technologies have shown that these tumors also feature significant inter-tumoral molecular heterogeneity. Molecular subtyping of these tumors has revealed several predictive and prognostic biomarkers. However, intra-tumoral heterogeneity may undermine the use of single biopsy analysis for determining tumor genotype and has implications for potential targeted therapies. The clinical relevance and theories of tumoral molecular heterogeneity in glioblastoma are discussed.

  4. Knowledge Sharing in Knowledge-Intensive Firms

    DEFF Research Database (Denmark)

    Gupta, Akshey; Michailova, Snejina

    2004-01-01

    This paper is a study of the knowledge-sharing difficulties experienced by three departments in a knowledge-intensive firm. The case organization is a global consulting firm that has been on the forefront of knowledge management and has won several knowledge management related international accla...

  5. A Cellular Automaton Model for Heterogeneous and Incosistent Driver Behavior in Urban Traffic

    Institute of Scientific and Technical Information of China (English)

    LIUMing-Zhe; ZHAO Shi-Bo; WANG Rui-Li

    2012-01-01

    In this paper a cellular automaton model is proposed to describe driver behavior at a single-lane urban roundabout. Driver behavior has been considered as heterogeneous and inconsistent. Most traffic papers in the literature just discussed heterogeneous driver behavior, to our best knowledge. Two truncated Caussian distributions are used to model heterogeneous and inconsistent driver behavior, respectively. The physical meanings of two truncated distributions are indicated. This method may help enhance a better understanding of driver behavior at roundabout traffic, and even possibly provide references for roundabout design and management.

  6. Passive ventricular remodeling in cardiac disease: Focus on heterogeneity

    Directory of Open Access Journals (Sweden)

    Elise L Kessler

    2014-12-01

    Full Text Available Passive ventricular remodeling is defined by the process of molecular ventricular adaptation to different forms of cardiac pathophysiology. It includes changes in tissue architecture, such as hypertrophy, fiber disarray, alterations in cell size and fibrosis. Besides that, it also includes molecular remodeling of gap junctions, especially those composed by Connexin43 proteins (Cx43 in the ventricles that affect cell-to-cell propagation of the electrical impulse, and changes in the sodium channels that modify excitability. All those alterations appear mainly in a heterogeneous manner, creating irregular and inhomogeneous electrical and mechanical coupling throughout the heart. This can predispose to reentry arrhythmias and adds to a further deterioration into heart failure. In this review, passive ventricular remodeling is described in Hypertrophic Cardiomyopathy (HCM, Dilated Cardiomyopathy (DCM, Ischemic Cardiomyopathy (ICM, and Arrhythmogenic Cardiomyopathy (ACM, with a main focus on the heterogeneity of those alterations mentioned above.

  7. Automated liquid operation method for microfluidic heterogeneous immunoassay.

    Science.gov (United States)

    Yi, Hui; Pan, Jian-Zhang; Shi, Xiao-Tong; Fang, Qun

    2013-02-15

    In this work, an automated liquid operation method for multistep heterogeneous immunoassay toward point of care testing (POCT) was proposed. A miniaturized peristaltic pump was developed to control the flow direction, flow time and flow rate in the microliter range according to a program. The peristaltic pump has the advantages of simple structure, small size, low cost, and easy to build and use. By coupling the peristaltic pump with an antibody-coated capillary and a reagent-preloaded cartridge, the complicated liquid handling operation for heterogeneous immunoassay, including sample metering and introduction, multistep reagent introduction and rinsing, could be triggered by an action and accomplished automatically in 12 min. The analytical performance of the present immunoassay system was demonstrated in the measurement of human IgG with fluorescence detection. A detection limit of 0.68 μg/mL IgG and a dynamic range of 2-300 μg/mL were obtained.

  8. Multiscale Analysis of Heterogeneous Media in the Peridynamic Formulation

    CERN Document Server

    Alali, Bacim

    2010-01-01

    A methodology is presented for investigating the dynamics of heterogeneous media using the nonlocal continuum model given by the peridynamic formulation. The approach presented here provides the ability to model the macroscopic dynamics while at the same time resolving the dynamics at the length scales of the microstructure. Central to the methodology is a novel two-scale evolution equation. The rescaled solution of this equation is shown to provide a strong approximation to the actual deformation inside the peridynamic material. The two scale evolution can be split into a microscopic component tracking the dynamics at the length scale of the heterogeneities and a macroscopic component tracking the volume averaged (homogenized) dynamics. The interplay between the microscopic and macroscopic dynamics is given by a coupled system of evolution equations. The equations show that the forces generated by the homogenized deformation inside the medium are related to the homogenized deformation through a history depen...

  9. On Knowledge Workers in the Knowledge Society

    Institute of Scientific and Technical Information of China (English)

    DU Yu-wei; WANG Shu-hong

    2004-01-01

    The paper makes a study on our present knowledge society and knowledge workers. After analyzing the reason that knowledge workers are the newly emerging dominant group in this knowledge society, it gets to the point that the real leadership in the age of knowledge are knowledge workers. Yet, they have to actively organize and learn together, otherwise, they would be same as the workers of industrial model. Only through organizational learning can knowledge workers turn into a very innovative learning organization dancing with the unexpected.

  10. Tumor Heterogeneity: Mechanisms and Bases for a Reliable Application of Molecular Marker Design

    Science.gov (United States)

    Diaz-Cano, Salvador J.

    2012-01-01

    Tumor heterogeneity is a confusing finding in the assessment of neoplasms, potentially resulting in inaccurate diagnostic, prognostic and predictive tests. This tumor heterogeneity is not always a random and unpredictable phenomenon, whose knowledge helps designing better tests. The biologic reasons for this intratumoral heterogeneity would then be important to understand both the natural history of neoplasms and the selection of test samples for reliable analysis. The main factors contributing to intratumoral heterogeneity inducing gene abnormalities or modifying its expression include: the gradient ischemic level within neoplasms, the action of tumor microenvironment (bidirectional interaction between tumor cells and stroma), mechanisms of intercellular transference of genetic information (exosomes), and differential mechanisms of sequence-independent modifications of genetic material and proteins. The intratumoral heterogeneity is at the origin of tumor progression and it is also the byproduct of the selection process during progression. Any analysis of heterogeneity mechanisms must be integrated within the process of segregation of genetic changes in tumor cells during the clonal expansion and progression of neoplasms. The evaluation of these mechanisms must also consider the redundancy and pleiotropism of molecular pathways, for which appropriate surrogate markers would support the presence or not of heterogeneous genetics and the main mechanisms responsible. This knowledge would constitute a solid scientific background for future therapeutic planning. PMID:22408433

  11. Tumor Heterogeneity: Mechanisms and Bases for a Reliable Application of Molecular Marker Design

    Directory of Open Access Journals (Sweden)

    Salvador J. Diaz-Cano

    2012-02-01

    Full Text Available Tumor heterogeneity is a confusing finding in the assessment of neoplasms, potentially resulting in inaccurate diagnostic, prognostic and predictive tests. This tumor heterogeneity is not always a random and unpredictable phenomenon, whose knowledge helps designing better tests. The biologic reasons for this intratumoral heterogeneity would then be important to understand both the natural history of neoplasms and the selection of test samples for reliable analysis. The main factors contributing to intratumoral heterogeneity inducing gene abnormalities or modifying its expression include: the gradient ischemic level within neoplasms, the action of tumor microenvironment (bidirectional interaction between tumor cells and stroma, mechanisms of intercellular transference of genetic information (exosomes, and differential mechanisms of sequence-independent modifications of genetic material and proteins. The intratumoral heterogeneity is at the origin of tumor progression and it is also the byproduct of the selection process during progression. Any analysis of heterogeneity mechanisms must be integrated within the process of segregation of genetic changes in tumor cells during the clonal expansion and progression of neoplasms. The evaluation of these mechanisms must also consider the redundancy and pleiotropism of molecular pathways, for which appropriate surrogate markers would support the presence or not of heterogeneous genetics and the main mechanisms responsible. This knowledge would constitute a solid scientific background for future therapeutic planning.

  12. The Digital Space Shuttle, 3D Graphics, and Knowledge Management

    Science.gov (United States)

    Gomez, Julian E.; Keller, Paul J.

    2003-01-01

    The Digital Shuttle is a knowledge management project that seeks to define symbiotic relationships between 3D graphics and formal knowledge representations (ontologies). 3D graphics provides geometric and visual content, in 2D and 3D CAD forms, and the capability to display systems knowledge. Because the data is so heterogeneous, and the interrelated data structures are complex, 3D graphics combined with ontologies provides mechanisms for navigating the data and visualizing relationships.

  13. The Digital Space Shuttle, 3D Graphics, and Knowledge Management

    Science.gov (United States)

    Gomez, Julian E.; Keller, Paul J.

    2003-01-01

    The Digital Shuttle is a knowledge management project that seeks to define symbiotic relationships between 3D graphics and formal knowledge representations (ontologies). 3D graphics provides geometric and visual content, in 2D and 3D CAD forms, and the capability to display systems knowledge. Because the data is so heterogeneous, and the interrelated data structures are complex, 3D graphics combined with ontologies provides mechanisms for navigating the data and visualizing relationships.

  14. Integrative self-knowledge and marital satisfaction.

    Science.gov (United States)

    Ghorbani, Nima; Watson, P J; Fayyaz, Fatemeh; Chen, Zhuo

    2015-01-01

    Married Iranian couples (N = 210) responded to the Integrative Self-Knowledge Scale along with a measure of marital satisfaction, the International Personality Item Pool (IPIP) Big Five, and an index of interpersonal problems. Integrative self-knowledge correlated positively with marital satisfaction, positively with all but the extraversion Big Five traits, and negatively with three indices of interpersonal problems. Integrative self-knowledge also mediated a number of personality relationships with marital satisfaction. Spouse-ratings of personality confirmed the adaptive implications of integrative self-knowledge for marriage. Linkages with questionnaire response styles supported the description of integrative self-knowledge as a measure of both self-insight and self-development. Results confirmed the potential of integrative self-knowledge for studying self-regulatory processes and suggested that the enhancement of self-knowledge may be a useful goal in efforts to strengthen marriages.

  15. Comment on the frozen QCD coupling

    CERN Document Server

    Ermolaev, B I; Troyan, S I

    2012-01-01

    The frozen QCD coupling is a parameter often used as an effective fixed coupling. It is supposed to mimic both the running coupling effects and the lack of knowledge of alpha_s in the infrared region. Usually the value of the frozen coupling is fixed from the analysis of the experimental data. We present a novel way to define such coupling(s) independently of the experiments. We argue that there are different frozen couplings which are used in the double- and single- logarithmic approximations. We introduce three kinds of the frozen couplings: the coupling used in DLA with a time-like argument (i.e. the coupling present in the non-singlet scattering amplitudes and DIS structure functions) which we find 0.24 approximately; the DLA coupling with a space-like argument (in e+e- -annihilation, in DY processes and in any scattering amplitude in the hard or backward kinematics) which is a factor two larger, namely 0.48. We also show that the frozen coupling in the single-logarithmic evolution equations like BFKL has...

  16. Adaptive heterogeneous multi-robot teams

    Energy Technology Data Exchange (ETDEWEB)

    Parker, L.E.

    1998-11-01

    This research addresses the problem of achieving fault tolerant cooperation within small- to medium-sized teams of heterogeneous mobile robots. The author describes a novel behavior-based, fully distributed architecture, called ALLIANCE, that utilizes adaptive action selection to achieve fault tolerant cooperative control in robot missions involving loosely coupled, largely independent tasks. The robots in this architecture possess a variety of high-level functions that they can perform during a mission, and must at all times select an appropriate action based on the requirements of the mission, the activities of other robots, the current environmental conditions, and their own internal states. Since such cooperative teams often work in dynamic and unpredictable environments, the software architecture allows the team members to respond robustly and reliably to unexpected environmental changes and modifications in the robot team that may occur due to mechanical failure, the learning of new skills, or the addition or removal of robots from the team by human intervention. After presenting ALLIANCE, the author describes in detail the experimental results of an implementation of this architecture on a team of physical mobile robots performing a cooperative box pushing demonstration. These experiments illustrate the ability of ALLIANCE to achieve adaptive, fault-tolerant cooperative control amidst dynamic changes in the capabilities of the robot team.

  17. Developing Higher-Order Materials Knowledge Systems

    Science.gov (United States)

    Fast, Anthony Nathan

    2011-12-01

    Advances in computational materials science and novel characterization techniques have allowed scientists to probe deeply into a diverse range of materials phenomena. These activities are producing enormous amounts of information regarding the roles of various hierarchical material features in the overall performance characteristics displayed by the material. Connecting the hierarchical information over disparate domains is at the crux of multiscale modeling. The inherent challenge of performing multiscale simulations is developing scale bridging relationships to couple material information between well separated length scales. Much progress has been made in the development of homogenization relationships which replace heterogeneous material features with effective homogenous descriptions. These relationships facilitate the flow of information from lower length scales to higher length scales. Meanwhile, most localization relationships that link the information from a from a higher length scale to a lower length scale are plagued by computationally intensive techniques which are not readily integrated into multiscale simulations. The challenge of executing fully coupled multiscale simulations is augmented by the need to incorporate the evolution of the material structure that may occur under conditions such as material processing. To address these challenges with multiscale simulation, a novel framework called the Materials Knowledge System (MKS) has been developed. This methodology efficiently extracts, stores, and recalls microstructure-property-processing localization relationships. This approach is built on the statistical continuum theories developed by Kroner that express the localization of the response field at the microscale using a series of highly complex convolution integrals, which have historically been evaluated analytically. The MKS approach dramatically improves the accuracy of these expressions by calibrating the convolution kernels in these

  18. A Reinforcement Sensor Embedded Vertical Handoff Controller for Vehicular Heterogeneous Wireless Networks

    Directory of Open Access Journals (Sweden)

    Lin Ma

    2013-11-01

    Full Text Available Vehicular communication platforms that provide real-time access to wireless networks have drawn more and more attention in recent years. IEEE 802.11p is the main radio access technology that supports communication for high mobility terminals, however, due to its limited coverage, IEEE 802.11p is usually deployed by coupling with cellular networks to achieve seamless mobility. In a heterogeneous cellular/802.11p network, vehicular communication is characterized by its short time span in association with a wireless local area network (WLAN. Moreover, for the media access control (MAC scheme used for WLAN, the network throughput dramatically decreases with increasing user quantity. In response to these compelling problems, we propose a reinforcement sensor (RFS embedded vertical handoff control strategy to support mobility management. The RFS has online learning capability and can provide optimal handoff decisions in an adaptive fashion without prior knowledge. The algorithm integrates considerations including vehicular mobility, traffic load, handoff latency, and network status. Simulation results verify that the proposed algorithm can adaptively adjust the handoff strategy, allowing users to stay connected to the best network. Furthermore, the algorithm can ensure that RSUs are adequate, thereby guaranteeing a high quality user experience.

  19. A reinforcement sensor embedded vertical handoff controller for vehicular heterogeneous wireless networks.

    Science.gov (United States)

    Li, Limin; Xu, Yubin; Soong, Boon-Hee; Ma, Lin

    2013-11-04

    Vehicular communication platforms that provide real-time access to wireless networks have drawn more and more attention in recent years. IEEE 802.11p is the main radio access technology that supports communication for high mobility terminals, however, due to its limited coverage, IEEE 802.11p is usually deployed by coupling with cellular networks to achieve seamless mobility. In a heterogeneous cellular/802.11p network, vehicular communication is characterized by its short time span in association with a wireless local area network (WLAN). Moreover, for the media access control (MAC) scheme used for WLAN, the network throughput dramatically decreases with increasing user quantity. In response to these compelling problems, we propose a reinforcement sensor (RFS) embedded vertical handoff control strategy to support mobility management. The RFS has online learning capability and can provide optimal handoff decisions in an adaptive fashion without prior knowledge. The algorithm integrates considerations including vehicular mobility, traffic load, handoff latency, and network status. Simulation results verify that the proposed algorithm can adaptively adjust the handoff strategy, allowing users to stay connected to the best network. Furthermore, the algorithm can ensure that RSUs are adequate, thereby guaranteeing a high quality user experience.

  20. Hydrological model coupling with ANNs

    Science.gov (United States)

    Kamp, R. G.; Savenije, H. H. G.

    2006-12-01

    Model coupling in general is necessary but complicated. Scientists develop and improve conceptual models to represent physical processes occurring in nature. The next step is to translate these concepts into a mathematical model and finally into a computer model. Problems may appear if the knowledge, encapsulated in a computer model and software program is needed for another purpose. In integrated water management this is often the case when connections between hydrological, hydraulic or ecological models are required. Coupling is difficult for many reasons, related to data formats, compatibility of scales, ability to modify source codes, etc. Hence, there is a need for an efficient and cost effective approach to model-coupling. One solution for model coupling is the use of Artificial Neural Networks (ANNs). The ANN can be used as a fast and effective model simulator which can connect different models. In this paper ANNs are used to couple four different models: a rainfall runoff model, a river channel routing model, an estuarine salt intrusion model, and an ecological model. The coupling as such has proven to be feasible and efficient. However the salt intrusion model appeared difficult to model accurately in an ANN. The ANN has difficulty to represent both short term (tidal) and long term (hydrological) processes.

  1. Cellular heterogeneity and molecular evolution in cancer.

    Science.gov (United States)

    Almendro, Vanessa; Marusyk, Andriy; Polyak, Kornelia

    2013-01-24

    Intratumor heterogeneity represents a major obstacle to effective cancer treatment and personalized medicine. However, investigators are now elucidating intratumor heterogeneity at the single-cell level due to improvements in technologies. Better understanding of the composition of tumors, and monitoring changes in cell populations during disease progression and treatment, will improve cancer diagnosis and therapeutic design. Measurements of intratumor heterogeneity may also be used as biomarkers to predict the risk of progression and therapeutic resistance. We summarize important considerations related to intratumor heterogeneity during tumor evolution. We also discuss experimental approaches that are commonly used to infer intratumor heterogeneity and describe how these methodologies can be translated into clinical practice.

  2. Personalized heterogeneous deformable model for fast volumetric registration.

    Science.gov (United States)

    Si, Weixin; Liao, Xiangyun; Wang, Qiong; Heng, Pheng Ann

    2017-02-20

    Biomechanical deformable volumetric registration can help improve safety of surgical interventions by ensuring the operations are extremely precise. However, this technique has been limited by the accuracy and the computational efficiency of patient-specific modeling. This study presents a tissue-tissue coupling strategy based on penalty method to model the heterogeneous behavior of deformable body, and estimate the personalized tissue-tissue coupling parameters in a data-driven way. Moreover, considering that the computational efficiency of biomechanical model is highly dependent on the mechanical resolution, a practical coarse-to-fine scheme is proposed to increase runtime efficiency. Particularly, a detail enrichment database is established in an offline fashion to represent the mapping relationship between the deformation results of high-resolution hexahedral mesh extracted from the raw medical data and a newly constructed low-resolution hexahedral mesh. At runtime, the mechanical behavior of human organ under interactions is simulated with this low-resolution hexahedral mesh, then the microstructures are synthesized in virtue of the detail enrichment database. The proposed method is validated by volumetric registration in an abdominal phantom compression experiments. Our personalized heterogeneous deformable model can well describe the coupling effects between different tissues of the phantom. Compared with high-resolution heterogeneous deformable model, the low-resolution deformable model with our detail enrichment database can achieve 9.4× faster, and the average target registration error is 3.42 mm, which demonstrates that the proposed method shows better volumetric registration performance than state-of-the-art. Our framework can well balance the precision and efficiency, and has great potential to be adopted in the practical augmented reality image-guided robotic systems.

  3. The QCD running coupling

    Science.gov (United States)

    Deur, Alexandre; Brodsky, Stanley J.; de Téramond, Guy F.

    2016-09-01

    We review the present theoretical and empirical knowledge for αs, the fundamental coupling underlying the interactions of quarks and gluons in Quantum Chromodynamics (QCD). The dependence of αs(Q2) on momentum transfer Q encodes the underlying dynamics of hadron physics-from color confinement in the infrared domain to asymptotic freedom at short distances. We review constraints on αs(Q2) at high Q2, as predicted by perturbative QCD, and its analytic behavior at small Q2, based on models of nonperturbative dynamics. In the introductory part of this review, we explain the phenomenological meaning of the coupling, the reason for its running, and the challenges facing a complete understanding of its analytic behavior in the infrared domain. In the second, more technical, part of the review, we discuss the behavior of αs(Q2) in the high momentum transfer domain of QCD. We review how αs is defined, including its renormalization scheme dependence, the definition of its renormalization scale, the utility of effective charges, as well as "Commensurate Scale Relations" which connect the various definitions of the QCD coupling without renormalization-scale ambiguity. We also report recent significant measurements and advanced theoretical analyses which have led to precise QCD predictions at high energy. As an example of an important optimization procedure, we discuss the "Principle of Maximum Conformality", which enhances QCD's predictive power by removing the dependence of the predictions for physical observables on the choice of theoretical conventions such as the renormalization scheme. In the last part of the review, we discuss the challenge of understanding the analytic behavior αs(Q2) in the low momentum transfer domain. We survey various theoretical models for the nonperturbative strongly coupled regime, such as the light-front holographic approach to QCD. This new framework predicts the form of the quark-confinement potential underlying hadron spectroscopy and

  4. Cognitive heterogeneity in Williams syndrome.

    Science.gov (United States)

    Porter, Melanie A; Coltheart, Max

    2005-01-01

    This study used the Woodcock-Johnson Tests of Cognitive Ability-Revised to investigate a wide range of cognitive abilities in people with Williams syndrome (WS). It involved a comparatively large sample of 31 people with WS, but took a case-series approach. The study addressed the widespread claims of a characteristic "WS cognitive profile" by looking for heterogeneity rather than homogeneity. People with WS showed a variety of preserved (significantly above mental age [MA]), expected (at MA), and significantly impaired (significantly below MA) levels of functioning. Such results provide clear evidence for heterogeneity in cognitive functions within WS. We found the most homogeneity on a test of phonological processing and a test of phonological short-term memory, with half of the WS sample performing at MA levels on these tests. Interestingly, no WS individual showed a weakness on a test of nonverbal reasoning, and only one WS individual showed a weakness on a test of verbal comprehension. In addition, we found that strengths on analysis-synthesis and verbal analogies occurred only for WS individuals with an MA less than 5.5 years (our sample median MA); people with an MA greater than 5.5 years performed at MA level on these 2 tests. Results also provided preliminary evidence for distinct subgroups of WS people based on their cognitive strengths and weaknesses on a broad range of cognitive functions. On the basis of the findings, caution should be made in declaring a single cognitive profile that is characteristic of all individuals with WS. Just as there is heterogeneity in genetic and physical anomalies within WS, not all WS individuals share the same cognitive strengths and weaknesses. Also, not all WS individuals show the profile of a strength in verbal abilities and a weakness in spatial functions.

  5. Fundamental concepts in heterogeneous catalysis

    CERN Document Server

    Norskov, Jens K; Abild-Pedersen, Frank; Bligaard, Thomas

    2014-01-01

    This book is based on a graduate course and suitable as a primer for any newcomer to the field, this book is a detailed introduction to the experimental and computational methods that are used to study how solid surfaces act as catalysts.   Features include:First comprehensive description of modern theory of heterogeneous catalysisBasis for understanding and designing experiments in the field   Allows reader to understand catalyst design principlesIntroduction to important elements of energy transformation technologyTest driven at Stanford University over several semesters

  6. Heterogeneous photocatalysts in organic synthesis

    Science.gov (United States)

    Cherevatskaya, M.; König, B.

    2014-03-01

    The review deals with the application of inorganic semiconductors in organic synthesis. Although the majority of reported reactions still aim at the photocatalytic decomposition of organic compounds, the number of examples in synthetic applications is growing. The principal mechanisms of heterogeneous semiconductor photocatalysis are considered and examples illustrating the use of inorganic semiconductors in organic synthesis are given. The discussion is arranged according to the required excitation wavelength (UV or visible light) and to the new bond that is formed (carbon-carbon or carbon-heteroatom bond). The bibliography includes 47 references.

  7. Kinetics of heterogeneous catalytic reactions

    CERN Document Server

    Boudart, Michel

    2014-01-01

    This book is a critical account of the principles of the kinetics of heterogeneous catalytic reactions in the light of recent developments in surface science and catalysis science. Originally published in 1984. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These paperback editions preserve the original texts of these important books while presenting them in durable paperback editions. The goal of the Princeton Legacy Library is to vastly increase acc

  8. Lifetime of Sensor Network by Exploiting Heterogeneity- A Survey

    Directory of Open Access Journals (Sweden)

    Ritesh Kumar Singh

    2014-07-01

    Full Text Available Wireless sensor networks (WSN are emerging in various fields. A large number of sensors in these applications are unattended and work autonomously. Lifetime is an important parameter which is critical for different algorithms for data transfer. Moreover it is responsible for the throughput and the failure of the network. Heterogeneous wireless sensor network, on top of clustering technique, has evolved as the major parameter to increase the lifetime of the Sensor network, data transfer, energy consumption and the scalability of the sensor network. This paper surveys the different clustering algorithm and dependencies for heterogeneous wireless sensor network. This paper is for scholars to gain sufficient knowledge of wireless sensor network (WSN, its important characteristics, and performance metrics with factors responsible for a WSN system. It can help a scholar to start a quick research by understanding all the respective parameters and energy oriented strategies in WSN.

  9. Photoacoustic image reconstruction: material detection and acoustical heterogeneities

    Science.gov (United States)

    Schoeder, S.; Kronbichler, M.; Wall, W. A.

    2017-05-01

    The correct consideration of acoustical heterogeneities in the context of photoacoustic image reconstruction is an open topic. In this publication a physically motivated algorithm is proposed that reconstructs the optical absorption and diffusion coefficients using a gradient-based scheme. The simultaneous reconstruction of both material properties allows for a subsequent material identification and an accordant update of the acoustical material properties. The algorithm is general in terms of illumination scenarios, detection geometries and applications. No prior knowledge on material distributions needs to be provided, only expected materials have to be specified. Numerical experiments are performed to gain insight into the complex inverse problem and to validate the proposed method. Results show that acoustical heterogeneities are correctly detected improving the optical images.

  10. Heterogeneity of Pre-diabetes and Type 2 Diabetes

    DEFF Research Database (Denmark)

    Faerch, Kristine; Hulmán, Adam; Solomon, Thomas P J

    2016-01-01

    glycaemic markers of diabetes risk can provide additional information to the established diagnostic criteria. A better understanding of the underlying mechanisms responsible for elevated fasting versus postprandial glucose concentration, as well as knowledge about the expected responsiveness to treatment......Type 2 diabetes is a heterogeneous disease with large variation in the relative contributions of insulin resistance and beta cell dysfunction between subgroups and individuals. Some of these differences are reflected in the way people are diagnosed. However, differences in glucose regulation exist...... among individuals even in those with comparable diagnostic glucose levels. In this review we address the heterogeneity of pre-diabetes and type 2 diabetes with special emphasis on differences in the pathophysiology and treatment responses related to the diagnostic criteria. We also discuss whether novel...

  11. Heterogeneity of pre-diabetes and type 2 diabetes

    DEFF Research Database (Denmark)

    Faerch, Kristine; Hulman, Adam; Solomon, Thomas

    2016-01-01

    glycaemic markers of diabetes risk can provide additional information to the established diagnostic criteria. A better understanding of the underlying mechanisms responsible for elevated fasting versus postprandial glucose concentration, as well as knowledge about the expected responsiveness to treatment......Type 2 diabetes is a heterogeneous disease with large variation in the relative contributions of insulin resistance and beta cell dysfunction between subtypes and individuals. Some of these differences are reflected in the way people are diagnosed. However, differences in glucose regulation exist...... among individuals even in those with comparable diagnostic glucose levels. In this review we address the heterogeneity of pre-diabetes and type 2 diabetes with special emphasis on differences in the pathophysiology and treatment responses related to the diagnostic criteria. We also discuss whether novel...

  12. Computer Aided Design Modeling for Heterogeneous Objects

    CERN Document Server

    Gupta, Vikas; Tandon, Puneet

    2010-01-01

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

  13. The Three-Dimensional Combustion of Heterogeneous Propellants

    Science.gov (United States)

    Massa, L.; Jackson, T. L.; Buckmaster, J.; Campbell, M.

    2002-01-01

    A numerical framework is described which permits the calculation of the 3-D combustion field supported by a heterogeneous propellant, allowing for complete coupling between the condensed phase physics, the gas-phase physics, and the unsteady, uneven, regressing surface. A random packing algorithm is used to construct models of ammonium-perchlorate in hydroxyl-terminated-polybutadiene propellants which mimic experimental propellants designed by R. Miller, and these are numerically burnt. Mean burning rates are compared with experimental data for four packs, over a pressure range of 7-200atm.

  14. John Bowlby and couple psychotherapy.

    Science.gov (United States)

    Clulow, Christopher

    2007-12-01

    The centenary of John Bowlby's birth provides a context for considering the policy, research and practice legacies that he left for practitioners working in many different fields supporting couples and families. Part historical, and part forwardlooking, this paper considers the links between attachment in the infant-parent dyad that was at the heart of Bowlby's concern and the nature of the affective ties that bind couples together in adult romantic relationships. An overview of the influence of his theory on family policy and adult attachment research is followed by an appreciation of its significance for the practice of couple psychotherapy. The paper concludes with a comment on the implications of current neuroscience knowledge for therapeutic technique.

  15. Metaphors for Knowledge in Knowledge Intensive Groups

    DEFF Research Database (Denmark)

    Greve, Linda

    2016-01-01

    We live in a knowledge society. This fact places certain demands on education, cooperation, knowledge sharing, knowledge transfer, knowledge workers, knowledge communication and on management. However it also places demands on our perception of knowledge. Theory would suggest a number of differen...... using metaphors as tools for understanding employees and their attitude and feelings in e.g. change processes and strategy work. Thus the perspective is dual. Metaphors in organizational development and management can act as both tools for communication and tools for understanding...

  16. Link prediction via generalized coupled tensor factorisation

    DEFF Research Database (Denmark)

    Ermiş, Beyza; Evrim, Acar Ataman; Taylan Cemgil, A.

    2012-01-01

    This study deals with the missing link prediction problem: the problem of predicting the existence of missing connections between entities of interest. We address link prediction using coupled analysis of relational datasets represented as heterogeneous data, i.e., datasets in the form of matrices...... different loss functions. Numerical experiments demonstrate that joint analysis of data from multiple sources via coupled factorisation improves the link prediction performance and the selection of right loss function and tensor model is crucial for accurately predicting missing links....

  17. Analysis on smoking behavior, tobacco control knowledge and willingness of smoke-free wedding among 740 prospective couples%740名准新人吸烟行为、控烟知识及无烟婚礼意愿调查分析

    Institute of Scientific and Technical Information of China (English)

    郭妤洁; 吴青青; 徐水洋; 徐越; 王磊; 朱大方

    2012-01-01

    Objective To understand status of smoking behaviors, knowledge and attitudes of tobacco control among prospective couples, and provide evidence for tobacco control intervention. Methods With convenience sampling, a questionnaire survey about tobacco control knowledge and willingness of smoking-free wedding were conducted among 740 pro-spective couples in Hangzhou. Results The smoking rate was 13. 51% among the prospective couples. 65. 54% of the family members were smoking, and most smokers had their father. 54. 74% of them took first tobacco when they were 18 to 22 years. The awareness rate of "stroke" and "heart disease" caused by smoking were 41. 35% and 53. 24% , respectively. The awareness rate of "secondhand smoke could cause heart disease" was 59. 19%. 85. 95% of them supported tobacco control in public places. 62. 16% of them were willing to hold a smoke-free wedding. Conclusion The awareness rates of smoking and second smoking could cause diseases among prospective couples were low, and their willingness of smoke-free wedding were also low, while the smoking rate of their family members was high. It was suggested that government should further strengthen knowledge dissemination of tobacco health hazard, implement indoor smoke-free environment policy, and advocate the healthy custom of no cigarette to raise the self-protection awareness of the public and reduce the harm of tobacco.%目的 了解准新人的吸烟行为、烟草控制知识和态度现状,为实施控烟干预提供依据.方法 采用方便抽样的方法,对杭州市740名准新人的控烟知识及举办无烟婚礼意愿进行调查分析.结果 准新人现在吸烟率为13.51%;65.54%准新人的家庭成员吸烟,且吸烟者大多有父亲;54.74%现在吸烟的准新人吸第一支烟的年龄在18~22岁;准新人对吸烟引起中风和心脏病的知晓率分别为41.35%和53.24%,对二手烟雾引起成人心脏疾病的知晓率为59.19%;85.95%的准新人

  18. Reintegration Difficulty of Military Couples Following Deployment

    Science.gov (United States)

    2016-07-01

    data from a fairly large and geographically dispersed cohort, but it prevented us from probing people’s answers. Interview procedures such as the ones...2010), then our data may understate the issues military couples face during their first deployment. Future work should seek more heterogeneous ...Valdez, Geena Wakeley, and Lauren Whalley for their help with recruitment and coding. Funding This research was supported by a seed grant from the

  19. Theory for electrochemical impedance spectroscopy of heterogeneous electrode with distributed capacitance and charge transfer resistance

    Indian Academy of Sciences (India)

    SHWETA DHILLON; RAMA KANT

    2017-08-01

    Randles-Ershler admittance model is extensively used in the modeling of batteries, fuel cells, sensors etc. It is also used in understanding response of the fundamental systems with coupled processes like charge transfer, diffusion, electric double layer charging and uncompensated solution resistance. Wegeneralize phenomenological theory for the Randles-Ershler admittance at the electrode with double layer capacitance and charge transfer heterogeneity, viz., non-uniform double layer capacitance and charge transfer resistance (c d and R CT). Electrode heterogeneity is modeled through distribution functions of R CT and c d, viz., log-normal distribution function. High frequency region captures influence of electric double layer while intermediate frequency region captures influence from the charge transfer resistance of heterogeneous electrode. A heterogeneous electrode with mean charge transfer resistance $\\bar{R CT}$ shows faster charge transfer kinetics over a electrode with uniform charge transfer resistance ($\\bar{R CT}$). It is also observed that a heterogeneous electrode having high mean with large variance in the R CT and c d can behave same as an electrode having low mean with small variance in the R CT and c d. The origin of coupling of uncompensated solution resistance (between working and reference electrode) with the charge transfer kinetics is explained. Finally, our model provides a simple route to understand the effect of spatial heterogeneity.

  20. Evaluation of an educational program on deciphering heterogeneity for medical coverage decisions.

    Science.gov (United States)

    Warholak, Terri L; Hilgaertner, Jianhua W; Dean, Joni L; Taylor, Ann M; Hines, Lisa E; Hurwitz, Jason; Brown, Mary; Malone, Daniel C

    2014-06-01

    It is increasingly important for decision makers, such as medical and pharmacy managers (or pharmacy therapeutics committee members and staff), to understand the variation and diversity in treatment response as decisions shift from an individual patient perspective to optimizing care for populations of patients. To assess the effectiveness of an instructional program on heterogeneity designed for medical and pharmacy managers. A live educational program was offered to members of the Academy of Managed Care Pharmacy at the fall 2012 educational meeting and also to medical directors and managers attending a national payer roundtable meeting in October 2012. Participants completed a retrospective pretest-posttest assessment of their knowledge, attitudes, and self-efficacy immediately following the program. Participants were offered the opportunity to participate in a follow-up assessment 6 months later. Willing participants for the follow-up assessment were contacted via e-mail and telephone. Rasch rating scale models were used to compare pre- and postscores measuring participants' knowledge about and attitude towards heterogeneity. A total of 49 individuals completed the retrospective pretest-posttest assessment and agreed to be a part of the program evaluation. Fifty percent (n = 25) of participants had heard of the phrase "heterogeneity of treatment effect," and 36 (72%) were familiar with the phrase "individualized treatment effect" prior to the live program. Participants reported a significant improvement in knowledge of heterogeneity (P  less than  0.01) and attitudes about heterogeneity (P  less than  0.01) immediately after attending the program. At the time of the educational program, participants had either never considered heterogeneity (26%) or reported not knowing (28%) whether their organizations considered it when determining basic coverage. Participants were more likely to report "sometimes" considering heterogeneity for determining

  1. Heterogeneous Transmutation Sodium Fast Reactor

    Energy Technology Data Exchange (ETDEWEB)

    S. E. Bays

    2007-09-01

    The threshold-fission (fertile) nature of Am-241 is used to destroy this minor actinide by capitalizing upon neutron capture instead of fission within a sodium fast reactor. This neutron-capture and its subsequent decay chain leads to the breeding of even neutron number plutonium isotopes. A slightly moderated target design is proposed for breeding plutonium in an axial blanket located above the active “fast reactor” driver fuel region. A parametric study on the core height and fuel pin diameter-to-pitch ratio is used to explore the reactor and fuel cycle aspects of this design. This study resulted in both non-flattened and flattened core geometries. Both of these designs demonstrated a high capacity for removing americium from the fuel cycle. A reactivity coefficient analysis revealed that this heterogeneous design will have comparable safety aspects to a homogeneous reactor of comparable size. A mass balance analysis revealed that the heterogeneous design may reduce the number of fast reactors needed to close the current once-through light water reactor fuel cycle.

  2. Immunophenotype Heterogeneity in Nasal Glomangiopericytoma

    Directory of Open Access Journals (Sweden)

    Adriana Handra-Luca

    2015-01-01

    Full Text Available Nasal glomangiopericytoma is rare. The immunophenotype is heterogeneous, more frequently smooth-muscle-actin and CD34-positive. We report expression patterns for several vascular-related proteins such as CD99, CD146, Bcl2, and WT1 as well as for treatment-related proteins such as mTOR and EGFR in a nasal glomangiopericytoma. The patient (woman, 86 years presented with a left nasal tumefaction. The resected specimen (1.5-cm showed a glomangiopericytoma. Tumor cells expressed smooth-muscle-actin, CD31, CD34, and progesterone receptor. They also expressed the vascular-cell-related proteins Bcl2, CD99, CD146, and WT1, as well as mTOR and EGFR. Nasal glomangiopericytomas show immunohistochemical heterogeneity for vascular-related markers, suggesting a possible extensive pericytic differentiation. The expression of potential targets for drug treatments such as mTOR and EGFR may impact on the clinical follow-up of these tumors occurring at advanced ages, which may require complex surgery.

  3. Knowledge Management as Attention

    DEFF Research Database (Denmark)

    Kreiner, Kristian

    2004-01-01

    This article explores the case of product development for insights into the potential role of knowledge management. Current literature on knowledge management entertains the notion that knowledge management is a specific set of practices - separate enough to allow specialization of responsibility....... By common standard, the proclaimed responsibility of knowledge management is shared knowledge, saved learning costs and coordinated action in an organization. The significance of the practices of knowledge management is the intention of shared knowledge, saved learning costs and coordinated action....

  4. Knowledge transfer between small manufacturing enterprises

    OpenAIRE

    Skandalakis, Alexandros

    1999-01-01

    This thesis illustrates that didactic and gnostic practices, identified through a structured Knowledge Transfer Framework, can effect business improvement in Small and Medium-sized Enterprises. Small and Medium-sized Enterprises form a significant heterogeneous economic force. They strengthen the capacity of a country to generate employment and wealth for the general benefit of regional and national economies. The importance of SMEs in the prosperity of a society and their c...

  5. Serving Diverse Knowledge Systems in Academia

    Directory of Open Access Journals (Sweden)

    William F. Birdsall

    2009-06-01

    Full Text Available Libraries and academic disciplines are experiencing a major transformation to the digital era. A challenge for libraries is to adapt and coordinate their transformation with differing rates and types of changes in teaching, research, and scholarly communication among the disciplines they serve. This paper argues libraries need to acknowledge the diversity of knowledge systems and adopt a strategy that requires collaboration between libraries and multiple communities of knowing in the development and provision of heterogeneous services.

  6. Knowledge management: organizing nursing care knowledge.

    Science.gov (United States)

    Anderson, Jane A; Willson, Pamela

    2009-01-01

    Almost everything we do in nursing is based on our knowledge. In 1984, Benner (From Novice to Expert: Excellence and Power in Clinical Nursing Practice. Menlo Park, CA: Addison-Wesley; 1984) described nursing knowledge as the culmination of practical experience and evidence from research, which over time becomes the "know-how" of clinical experience. This "know-how" knowledge asset is dynamic and initially develops in the novice critical care nurse, expands within competent and proficient nurses, and is actualized in the expert intensive care nurse. Collectively, practical "know-how" and investigational (evidence-based) knowledge culminate into the "knowledge of caring" that defines the profession of nursing. The purpose of this article is to examine the concept of knowledge management as a framework for identifying, organizing, analyzing, and translating nursing knowledge into daily practice. Knowledge management is described in a model case and implemented in a nursing research project.

  7. Overcoming knowledge stickiness in scientific knowledge transfer.

    Science.gov (United States)

    Blackman, Deborah; Benson, Angela M

    2012-07-01

    This paper explores the transfer and dissemination of knowledge between scientists, the volunteers who collect the knowledge and the communities which learn from it in order to implement change. The role of knowledge "stickiness" in the reduction of knowledge transfer is outlined. The characteristics of the knowledge and the situation combine to develop a range of factors, "stickiness predictors," which can deter knowledge transfer. These stickiness predictors are used to analyse data gathered from three qualitative cases, which were developed from both participant observation and semi-structured interviews studying the interactions between the scientists, volunteers and organisations. A reconsideration of the way that knowledge and knowledge transfer are being conceptualised by scientists is proposed, in order to enable "stickiness" factors to be recognised and managed, thereby increasing the potential for scientific literacy. A move towards a more broadly constituted community of practice is proposed.

  8. Knowledge Based Strategies for Knowledge Based Organizations

    National Research Council Canada - National Science Library

    Madalina Cristina Tocan

    2012-01-01

    In the present, we can observe that a new economy is arising. It is an economy based on knowledge and ideas, in which the key factor for prosperity and for creation of the new jobs is the knowledge capitalization...

  9. Changes in porosity, permeability and surface area during rock dissolution: effects of mineralogical heterogeneity

    CERN Document Server

    Min, Ting; Chen, Li; Kang, Qinjun; Tao, Wen-Quan

    2015-01-01

    Effects of heterogeneity of mineral distribution and reaction rate on the rock dissolution process are investigated using a pore-scale reactive transport model based on the lattice Boltzmann method. Coupled fluid flow, species transport, chemical reaction and solid structure alternation due to dissolution are simulated. Effects of mineral distributions and chemical heterogeneity on the dissolution behaviors and evolutions of hydrologic properties are studied under different reactive transport conditions. Simulation results show that the coupling between advection, diffusion and reaction as well as the mineralogical heterogeneity leads to complex reactive transport behaviors and complicated temporal evolutions of hydrologic properties including porosity, permeability and reactive surface. Diverse relationships between surface area and volume are predicted, which cannot be described by simple models such as the spherical-grain model. Porosity-permeability relationships also differ under different mineral distri...

  10. Incorporating systems dynamics and spatial heterogeneity in integrated assessment of agricultural production systems

    NARCIS (Netherlands)

    Antle, J.M.; Stoorvogel, J.J.

    2006-01-01

    Agricultural systems are complex and dynamic, being made up of interacting bio-physical and human sub-systems. Moreover, agricultural systems are remarkably diverse, both within geographic regions and across regions. Accordingly, this paper focuses on dynamics and heterogeneity in coupled, multi-dis

  11. Knowledge spillover processes as complex networks

    Science.gov (United States)

    Konno, Tomohiko

    2016-11-01

    We introduce the model of knowledge spillover on networks. Knowledge spillover is a major source of economic growth; and is a representative externality in economic phenomena. We show that the model has the following four characteristics: (1) the long-run growth rate is not relevant to the mean degree, but is determined by the mean degree of the nearest neighbors; (2) the productivity level of a firm is proportional to the degree of the firm; (3) the long-run growth rate increases with the increasing heterogeneity of the network; and (4) of three representative networks, the largest growth rate is in scale-free networks and the least in regular networks.

  12. Knowledge service decision making in business incubators based on the supernetwork model

    Science.gov (United States)

    Zhao, Liming; Zhang, Haihong; Wu, Wenqing

    2017-08-01

    As valuable resources for incubating firms, knowledge resources have received gradually increasing attention from all types of business incubators, and business incubators use a variety of knowledge services to stimulate rapid growth in incubating firms. Based on previous research, we generalize the knowledge transfer and knowledge networking services of two main forms of knowledge services and further divide knowledge transfer services into knowledge depth services and knowledge breadth services. Then, we construct the business incubators' knowledge supernetwork model, describe the evolution mechanism among heterogeneous agents and utilize a simulation to explore the performance variance of different business incubators' knowledge services. The simulation results show that knowledge stock increases faster when business incubators are able to provide knowledge services to more incubating firms and that the degree of discrepancy in the knowledge stock increases during the process of knowledge growth. Further, knowledge transfer services lead to greater differences in the knowledge structure, while knowledge networking services lead to smaller differences. Regarding the two types of knowledge transfer services, knowledge depth services are more conducive to knowledge growth than knowledge breadth services, but knowledge depth services lead to greater gaps in knowledge stocks and greater differences in knowledge structures. Overall, it is optimal for business incubators to select a single knowledge service or portfolio strategy based on the amount of time and energy expended on the two types of knowledge services.

  13. Knowledge Based Strategies for Knowledge Based Organizations

    OpenAIRE

    2012-01-01

    In the present, we can observe that a new economy is arising. It is an economy based on knowledge and ideas, in which the key factor for prosperity and for creation of the new jobs is the knowledge capitalization. Knowledge capitalization, intellectual capital, obtaining prosperity in the market economy imposes a new terminology, new managerial methods and techniques, new technologies and also new strategies. In other words, knowledge based economy, as a new type of economy; impose a new type...

  14. Inferential knowledge, externalism and self-knowledge.

    OpenAIRE

    R G Ford

    2004-01-01

    Privileged self-knowledge says, roughly, that we have non-empirical knowledge of our own thoughts. Externalism about mental content says, roughly, that our mental states are determined at least in part by our environment. It has been alleged that jointly assuming externalism about mental content and privileged self-knowledge are true has the consequence that any subject can have non-empirical knowledge of her own environment and this is intuitively absurd. The thesis investigates in various w...

  15. Integrable Couplings of the Coupled Burgers Hierarchy

    Institute of Scientific and Technical Information of China (English)

    XIATie-Cheng; CHENXiao-Hong; CHENDeng-Yuan; ZHANGYu-Feng

    2004-01-01

    In this letter, a new loop algebra G is constructed, from which a new isospectral problem is established. It follows that integrable couplings of the well-known coupled Burgers hierarchy are obtained.

  16. Knowledge Management, Codification and Tacit Knowledge

    Science.gov (United States)

    Kimble, Chris

    2013-01-01

    Introduction: This article returns to a theme addressed in Vol. 8(1) October 2002 of the journal: knowledge management and the problem of managing tacit knowledge. Method: The article is primarily a review and analysis of the literature associated with the management of knowledge. In particular, it focuses on the works of a group of economists who…

  17. Teaching Chinese in heterogeneous classrooms: strategies and practices

    Directory of Open Access Journals (Sweden)

    Rong Zhang Fernandez

    2014-12-01

    Full Text Available The heterogeneous nature of the Chinese classroom is a reality in the teaching of Chinese in France, both in secondary and higher education. This heterogeneity is due to several reasons: different levels of language knowledge, different origins and backgrounds of the students, different teaching/learning objectives, different cultural and family background, and social factors. Our research has been conducted in  a final-year LIE college class (langue inter-établissement; in a French secondary school. In our study, the following questions have been posed: How to best adapt the teaching of Chinese to fit the needs of all students? Would differentiated instruction be a solution? What would be the best strategies and practices, in view of the CEFR requirements related to teaching content, to tasks and to assessment? Taking into account a detailed analysis of the class in question in terms of the type of students, the differences in their knowledge of language, and their learning goals, , we adopt  the theory of differentiated instruction –  its main ideas strategies, its overall methodology and practical techniques to address the difficulties ensuing from classroom heterogeneity. The differentiation is implemented at the level of content, task selection, course structure and evaluation. Are there any limitations to differentiated instruction? Strong discrepancies in the levels of students’ knowledge is potentially a problem, and differences in their work pace as well as the teachers’ increased workload can also present difficulties. New ways of organizing language classes such as grouping students on the basis of their various language skills could help solve these issues.

  18. Identifying the influential aquifer heterogeneity factor on nitrate reduction processes by numerical simulation

    Science.gov (United States)

    Jang, E.; He, W.; Savoy, H.; Dietrich, P.; Kolditz, O.; Rubin, Y.; Schüth, C.; Kalbacher, T.

    2017-01-01

    Nitrate reduction reactions in groundwater systems are strongly influenced by various aquifer heterogeneity factors that affect the transport of chemical species, spatial distribution of redox reactive substances and, as a result, the overall nitrate reduction efficiency. In this study, we investigated the influence of physical and chemical aquifer heterogeneity, with a focus on nitrate transport and redox transformation processes. A numerical modeling study for simulating coupled hydrological-geochemical aquifer heterogeneity was conducted in order to improve our understanding of the influence of the aquifer heterogeneity on the nitrate reduction reactions and to identify the most influential aquifer heterogeneity factors throughout the simulation. Results show that the most influential aquifer heterogeneity factors could change over time. With abundant presence of electron donors in the high permeable zones (initial stage), physical aquifer heterogeneity significantly influences the nitrate reduction since it enables the preferential transport of nitrate to these zones and enhances mixing of reactive partners. Chemical aquifer heterogeneity plays a comparatively minor role. Increasing the spatial variability of the hydraulic conductivity also increases the nitrate removal efficiency of the system. However, ignoring chemical aquifer heterogeneity can lead to an underestimation of nitrate removals in long-term behavior. With the increase of the spatial variability of the electron donor, i.e. chemical heterogeneity, the number of the "hot spots" i.e. zones with comparably higher reactivity, should also increase. Hence, nitrate removal efficiencies will also be spatially variable but overall removal efficiency will be sustained if longer time scales are considered and nitrate fronts reach these high reactivity zones.

  19. Embedding Data within Knowledge Spaces

    CERN Document Server

    Myers, James D; Gaynor, Jeff; Plutchak, Joel; Bajcsy, Peter; Kastner, Jason; Kotwani, Kailash; Lee, Jong Sung; Marini, Luigi; Kooper, Rob; McGrath, Robert E; McLaren, Terry; Rodriguez, Alejandro; Liu, Yong

    2009-01-01

    The promise of e-Science will only be realized when data is discoverable, accessible, and comprehensible within distributed teams, across disciplines, and over the long-term--without reliance on out-of-band (non-digital) means. We have developed the open-source Tupelo semantic content management framework and are employing it to manage a wide range of e-Science entities (including data, documents, workflows, people, and projects) and a broad range of metadata (including provenance, social networks, geospatial relationships, temporal relations, and domain descriptions). Tupelo couples the use of global identifiers and resource description framework (RDF) statements with an aggregatable content repository model to provide a unified space for securely managing distributed heterogeneous content and relationships.

  20. Surfkin: A program to solve transient and steady state heterogeneous reaction kinetics

    Energy Technology Data Exchange (ETDEWEB)

    COLTRIN,MICHAEL E.; WIXOM,RYAN R.; DANDY,DAVID S.

    2000-05-01

    Heterogeneous chemical reactions occurring at a gas/surface interface are fundamental in a variety of important applications, such as combustion, catalysis, chemical vapor deposition and plasma processing. Detailed simulation of these processes may involve complex, coupled fluid flow, heat transfer, gas-phase chemistry, in addition to heterogeneous reaction chemistry. This report documents the Surfkin program, which simulates the kinetics of heterogeneous chemical reactions. The program is designed for use with the Chemkin and Surface Chemkin (heterogeneous chemistry) programs. It calculates time-dependent or steady state surface site fractions and bulk-species production/destruction rates. The surface temperature may be specified as a function of time to simulate a temperature-programmed desorption experiment, for example. This report serves as a user's manual for the program, explaining the required input and format of the output. Two detailed example problems are included to further illustrate the use of this program.

  1. Development of wire drawing textures in Cu Fe: the influence of macroscopic and microscopic heterogeneities

    Science.gov (United States)

    Bolmaro, R. E.; Fourty, A.; Signorelli, J. W.; Brokmeier, H.-G.

    2006-01-01

    The current paper presents a comparison of the influence over texture development of different heterogeneity levels of deformation. A viscoplastic self-consistent (VPSC) micromechanical model is coupled with a finite element method (FEM) to simulate wire drawing texture development in a two-phase Cu-Fe material. VPSC models are capable of simulating grain-to-grain heterogeneity, and FEM models can accomplish the task of simulating the macroscopic variation of velocity gradient due to geometrical constraints during wire drawing. Intra-grain heterogeneities are empirically built in the VPSC model by enforcing a common spin between closest neighbour grains. The results are contrasted and validated by neutron diffraction experimental textures. Different levels of heterogeneity are simulated, and the results are assessed and compared against Taylor based simulations. The 'curling' problem is also addressed by allowing the grains to interact through the co-spin model and the ellipsoid axes orientations to evolve independently.

  2. Coupling coefficients for coupled-cavity lasers

    Energy Technology Data Exchange (ETDEWEB)

    Lang, R.J.; Yariv, A.

    1987-03-01

    The authors derive simple, analytic formulas for the field coupling coefficients in a two-section coupled-cavity laser using a local field rate equation treatment. They show that there is a correction to the heuristic formulas based on power flow calculated by Marcuse; the correction is in agreement with numerical calculations from a coupled-mode approach.

  3. Dispersion of a solute in peristaltic motion of a couple stress fluid through a porous medium

    National Research Council Canada - National Science Library

    G. Radhakrishnamacharya; Habtu Alemayehu

    2012-01-01

    The paper presents an analytical solution for dispersion of a solute in the peristaltic motion of a couple stress fluid through a porous medium in the presence of both homogeneous and heterogeneous chemical reactions...

  4. Numerical Study of Critical Role of Rock Heterogeneity in Hydraulic Fracture Propagation

    Energy Technology Data Exchange (ETDEWEB)

    J. Zhou; H. Huang; M. Deo

    2016-03-01

    Log and seismic data indicate that most shale formations have strong heterogeneity. Conventional analytical and semi-analytical fracture models are not enough to simulate the complex fracture propagation in these highly heterogeneous formation. Without considering the intrinsic heterogeneity, predicted morphology of hydraulic fracture may be biased and misleading in optimizing the completion strategy. In this paper, a fully coupling fluid flow and geomechanics hydraulic fracture simulator based on dual-lattice Discrete Element Method (DEM) is used to predict the hydraulic fracture propagation in heterogeneous reservoir. The heterogeneity of rock is simulated by assigning different material force constant and critical strain to different particles and is adjusted by conditioning to the measured data and observed geological features. Based on proposed model, the effects of heterogeneity at different scale on micromechanical behavior and induced macroscopic fractures are examined. From the numerical results, the microcrack will be more inclined to form at the grain weaker interface. The conventional simulator with homogeneous assumption is not applicable for highly heterogeneous shale formation.

  5. Harvesting Information from Heterogeneous Sources

    DEFF Research Database (Denmark)

    2011-01-01

    The abundance of information regarding any topic makes the Internet a very good resource. Even though searching the Internet is very easy, what remains difficult is to automate the process of information extraction from the available online information due to the lack of structure and the diversity...... in the sharing methods. Most of the times, information is stored in different proprietary formats, complying with different standards and protocols which makes tasks like data mining and information harvesting very difficult. In this paper, an information harvesting tool (heteroHarvest) is presented...... with objectives to address these problems by filtering the useful information and then normalizing the information in a singular non hypertext format. We also discuss state of the art tools along with the shortcomings and present the results of an analysis carried out over different heterogeneous formats along...

  6. Emerging heterogeneities in Italian customs

    CERN Document Server

    Agliari, Elena; Galluzzi, Andrea; Javarone, Marco Alberto; Pizzoferrato, Andrea; Tantari, Daniele

    2015-01-01

    Since its unification, more than a century ago, Italy has experienced strong social and economical diversities between its southern and northern regions. In the last decades, Italy has undergone a severe economical and political crisis reflecting corruption at various levels of social stratification as well as a poor involvement of its population in the number of elections that occurred. This might be explained by a lack of confidence, or interest in the country as a whole, as if the primary social and political focus of its citizens could still lay at smaller regional scales, possibly evidencing the persistence of different cultural heritages. In order to shed lights on the possible existence of such heterogeneities, we perform a statistical-mechanics-driven analysis focusing on key social quantifiers, namely the evolution of autochthonous marriages (as family still plays as a fundamental brick in the edification of social aggregates) and of mixed marriages, namely those involving a foreign-born and a native...

  7. Heterogeneous Reburning By Mixed Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Anderson Hall

    2009-03-31

    Recent studies of heterogeneous reburning, i.e., reburning involving a coal-derived char, have elucidated its variables, kinetics and mechanisms that are valuable to the development of a highly efficient reburning process. Young lignite chars contain catalysts that not only reduce NO, but they also reduce HCN that is an important intermediate that recycles to NO in the burnout zone. Gaseous CO scavenges the surface oxides that are formed during NO reduction, regenerating the active sites on the char surface. Based on this mechanistic information, cost-effective mixed fuels containing these multiple features has been designed and tested in a simulated reburning apparatus. Remarkably high reduction of NO and HCN has been observed and it is anticipated that mixed fuel will remove 85% of NO in a three-stage reburning process.

  8. HETEROGENEOUS REBURNING BY MIXED FUELS

    Energy Technology Data Exchange (ETDEWEB)

    Wei-Yin Chen; Benson B. Gathitu

    2005-01-14

    Recent studies of heterogeneous reburning, i.e., reburning involving a coal-derived char, have elucidated its variables, kinetics and mechanisms that are valuable to the development of a highly efficient reburning process. Young lignite chars contain catalysts that not only reduce NO, but they also reduce HCN that is an important intermediate that recycles to NO in the burnout zone. Gaseous CO scavenges the surface oxides that are formed during NO reduction, regenerating the active sites on the char surface. Based on this mechanistic information, cost-effective mixed fuels containing these multiple features has been designed and tested in a simulated reburning apparatus. Remarkably high reduction of NO and HCN has been observed and it is anticipated that mixed fuel will remove 85% of NO in a three-stage reburning process.

  9. Heterogeneous fuel for hybrid rocket

    Science.gov (United States)

    Stickler, David B. (Inventor)

    1996-01-01

    Heterogeneous fuel compositions suitable for use in hybrid rocket engines and solid-fuel ramjet engines, The compositions include mixtures of a continuous phase, which forms a solid matrix, and a dispersed phase permanently distributed therein. The dispersed phase or the matrix vaporizes (or melts) and disperses into the gas flow much more rapidly than the other, creating depressions, voids and bumps within and on the surface of the remaining bulk material that continuously roughen its surface, This effect substantially enhances heat transfer from the combusting gas flow to the fuel surface, producing a correspondingly high burning rate, The dispersed phase may include solid particles, entrained liquid droplets, or gas-phase voids having dimensions roughly similar to the displacement scale height of the gas-flow boundary layer generated during combustion.

  10. Mesoscale poroelasticity of heterogeneous media

    Science.gov (United States)

    Monfared, Siavash; Laubie, Hadrien; Radjai, Farhang; Pellenq, Roland; Ulm, Franz-Josef

    Poroelastic behavior of heterogeneous media is revisited. Lattice Element Method (LEM) is used to model interaction between solid constituents due to a pressurized pore space. Exploring beyond mean-field based theories in continuum microporomechanics, local textural variations and its contribution to the global anisotropic poroelastic behavior of real multiphase porous media are captured. To this end, statistical distributions of mesoscale poroelastic coefficients from numerical simulations on X-ray microscopy scans of two different organic-rich shales with different microtextures are presented. The results are compared with predictions using mean-field based tools of continuum micromechanics. The textural dependency of strain localization and stress chain formation captured in this framework promises a powerful tool for modeling poroelastic response of complex porous composites and a path to incorporate local textural and elastic variations into a continuum description. Visiting Scientist, CNRS-MIT, MIT.

  11. Genetic heterogeneity of hepatocellular carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Unsal, H.; Isselbacher, K.J. (Massachusetts General Hospital Cancer Center, Charlestown, MA (United States)); Yakicier, C.; Marcais, C.; Ozturk, M. (Institut National de la Sante et de la Recherche Medicale, Lyon (France)); Kew, M. (Univ. of Witwatersrand, Johannesburg (South Africa)); Volkmann, M. (Univ. of Heidelberg (Germany)); Zentgraf, H. (Deutsches Krebsforschungszentrum, Heidelberg (Germany))

    1994-01-18

    The authors studied 80 hepatocellular carcinomas from three continents for p53 gene (TP53) mutations and hepatitis B virus (HBV) sequences. p53 mutations were frequent in tumors from Mozambique but not in tumors from South Africa, China, and Germany. Independent of geographic origin, most tumors were positive for HBV sequences. X gene coding sequences of HBV were detected in 78% of tumors, whereas viral sequences in the surface antigen- and core antigen-encoding regions were present in less than 35% of tumors. These observations indicate that hepatocellular carcinomas are genetically heterogeneous. Mozambican-types of hepatocellular carcinomas are characterized by a high incidence of p53 mutations related to aflatoxins. In other tumors, the rarity of p53 mutations combined with the frequent presence of viral X gene coding sequences suggests a possible interference of HBV with the wild-type p53 function.

  12. Operando research in heterogeneous catalysis

    CERN Document Server

    Groot, Irene

    2017-01-01

    This book is devoted to the emerging field of techniques for visualizing atomic-scale properties of active catalysts under actual working conditions, i.e. high gas pressures and high temperatures. It explains how to understand these observations in terms of the surface structures and dynamics and their detailed interplay with the gas phase. This provides an important new link between fundamental surface physics and chemistry, and applied catalysis. The book explains the motivation and the necessity of operando studies, and positions these with respect to the more traditional low-pressure investigations on the one hand and the reality of industrial catalysis on the other. The last decade has witnessed a rapid development of new experimental and theoretical tools for operando studies of heterogeneous catalysis. The book has a strong emphasis on the new techniques and illustrates how the challenges introduced by the harsh, operando conditions are faced for each of these new tools. Therefore, one can also read th...

  13. Heterogeneity in Preferences and Productivity

    DEFF Research Database (Denmark)

    Gørtz, Mette

    versus housework, 2) preferences for leisure compared to consumption, and 3) marginal utility of wealth, is correlated with the retirement decision. Based on US consumption and time use data for 2001 and 2003 from the Consumptions and Activities Mail Survey (CAMS), we study the patterns of individual...... choices of expenditure, household production and leisure for people in and around retirement. The unobserved individual heterogeneity factor is isolated by comparing cross-sectional evidence and panel data estimates of the effects of retirement on consumption and time allocation. Based on cross......-section data, we can identify a difference in consumption due to retirement status, but when the panel nature of the data is exploited, the effect of retirement on consumption is small and insignificant. Moreover, the analyses point at a large positive effect of retirement on household production. Our results...

  14. [Heterogenous expression of antimicrobial peptides].

    Science.gov (United States)

    Song, Shanshan; Hu, Guobin; Dong, Xianzhi

    2009-12-01

    Antimicrobial peptides (AMPs), a class of short proteins with a broad spectrum of antibacterial activities, are isolated from a wide variety of animals, both vertebrates and invertebrates, and plants as well as from bacteria and fungi. They are a key component of the innate immune response in most multicellular organisms. Owing to their potent, broad-spectrum antibacterial activities and uneasy developing of drug resistance, these peptides are of great clinical significance. However, preparation of AMPs at a large scale is a severe challenge to the development of the commercial products. Undoubtedly, construction of high-level biological expression systems for the production of AMPs is the key in its clinical application process. Herein, we summarize the progress in researches on heterogenous expression of AMPs in prokaryotic expression systems and eukaryotic expression systems.

  15. Spatial heterogeneity of ocean surface boundary conditions under sea ice

    Science.gov (United States)

    Barthélemy, Antoine; Fichefet, Thierry; Goosse, Hugues

    2016-06-01

    The high heterogeneity of sea ice properties implies that its effects on the ocean are spatially variable at horizontal scales as small as a few meters. Previous studies have shown that taking this variability into account in models could be required to simulate adequately mixed layer processes and the upper ocean temperature and salinity structures. Although many advanced sea ice models include a subgrid-scale ice thickness distribution, potentially providing heterogeneous surface boundary conditions, the information is lost in the coupling with a unique ocean grid cell underneath. The present paper provides a thorough examination of boundary conditions at the ocean surface in the NEMO-LIM model, which can be used as a guideline for studies implementing subgrid-scale ocean vertical mixing schemes. Freshwater, salt, solar heat and non-solar heat fluxes are examined, as well as the norm of the surface stress. All of the thermohaline fluxes vary considerably between the open water and ice fractions of grid cells. To a lesser extent, this is also the case for the surface stress. Moreover, the salt fluxes in both hemispheres and the solar heat fluxes in the Arctic show a dependence on the ice thickness category, with more intense fluxes for thinner ice, which promotes further subgrid-scale heterogeneity. Our analysis also points out biases in the simulated open water fraction and in the ice thickness distribution, which should be investigated in more details in order to ensure that the latter is used to the best advantage.

  16. Intelligent Classification in Huge Heterogeneous Data Sets

    Science.gov (United States)

    2015-06-01

    INTELLIGENT CLASSIFICATION IN HUGE HETEROGENEOUS DATA SETS JUNE 2015 FINAL TECHNICAL REPORT APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED...To) JUL 2013 – APR 2015 4. TITLE AND SUBTITLE INTELLIGENT CLASSIFICATION IN HUGE HETEROGENEOUS DATA SETS 5a. CONTRACT NUMBER IN-HOUSE 5b. GRANT...signals and through data dimension reduction, and to develop and tailor algorithms for the extraction of intelligence from several huge heterogeneous

  17. In-situ characterization of heterogeneous catalysts

    CERN Document Server

    Rodriguez, Jose A; Chupas, Peter J

    2013-01-01

    Helps researchers develop new catalysts for sustainable fuel and chemical production Reviewing the latest developments in the field, this book explores the in-situ characterization of heterogeneous catalysts, enabling readers to take full advantage of the sophisticated techniques used to study heterogeneous catalysts and reaction mechanisms. In using these techniques, readers can learn to improve the selectivity and the performance of catalysts and how to prepare catalysts as efficiently as possible, with minimum waste. In-situ Characterization of Heterogeneous Catalysts feat

  18. Demographic heterogeneity, cohort selection, and population growth

    OpenAIRE

    Bruce E. Kendall; Fox, Gordon A.; Fujiwara, Masami; Nogeire, Theresa M.

    2011-01-01

    Demographic heterogeneity—variation among individuals in survival and reproduction—is ubiquitous in natural populations. Structured population models address heterogeneity due to age, size, or major developmental stages. However, other important sources of demographic heterogeneity, such as genetic variation, spatial heterogeneity in the environment, maternal effects, and differential exposure to stressors, are often not easily measured and hence are modeled as stochasticity. Recent research ...

  19. Response function theories that account for size distribution effects - A review. [mathematical models concerning composite propellant heterogeneity effects on combustion instability

    Science.gov (United States)

    Cohen, N. S.

    1980-01-01

    The paper presents theoretical models developed to account for the heterogeneity of composite propellants in expressing the pressure-coupled combustion response function. It is noted that the model of Lengelle and Williams (1968) furnishes a viable basis to explain the effects of heterogeneity.

  20. From Knowledge to Action

    DEFF Research Database (Denmark)

    Hjelmar, Ulf; Møller, Anne Mette

    2016-01-01

    of a greater process of bringing knowledge to action, encompassing the social and organisational contexts of research utilisation. The article concludes by stating that knowledge portals have the potential to be effective instruments in knowledge-to-action processes. The two main challenges, however......In recent years, focus has been on the utilisation of research-based knowledge and evidence in social work policy and practice in order to make it more effective. A part of this process has been the launch of knowledge portals to make use of knowledge from research. In this article, we investigate...... how knowledge portals about vulnerable children and youth present knowledge and evidence, and how they try to work as ?knowledge brokers? or intermediaries of evidence. We argue that knowledge portals are not merely channels for dissemination of knowledge. Knowledge portals could be considered as part...

  1. Fixed export cost heterogeneity, trade and welfare

    DEFF Research Database (Denmark)

    Jørgensen, Jan Guldager; Schröder, Philipp J.H.

    2008-01-01

    -country intra-industry trade model where firms are of two different marginal costs types and where fixed export costs are heterogeneous across firms. This model traces many of the stylized facts of international trade. However, we find that with heterogeneous fixed export costs there exists a positive bilateral......Recent literature on the workhorse model of intra-industry trade has explored heterogeneous cost structures at the firm level. These approaches have proven to add realism and predictive power. This paper presents a new and simple heterogeneous-firms specification. We develop a symmetric two...

  2. Does Knowledge Sharing Pay?

    DEFF Research Database (Denmark)

    Mahnke, Volker; Pedersen, Torben; Venzin, Markus

    This empirical paper explores knowledge outflow from MNC subsidiaries and its impact on the MNC performance. We develop and test hypotheses derived from literature on MNC knowledge flows integrated with the perspective of knowledge-creating, self-interested MNC subsidiaries. The hypotheses are de...... between knowledge outflows and subsidiary performance. Our findings suggest that knowledge outflows increase a subsidiary's performance only up to a certain point and that too much knowledge sharing may be detrimental to the contributing subsidiary's performance....

  3. Heterogeneous reactions of epoxides in acidic media.

    Science.gov (United States)

    Lal, Vinita; Khalizov, Alexei F; Lin, Yun; Galvan, Maria D; Connell, Brian T; Zhang, Renyi

    2012-06-21

    Epoxides have recently been identified as important intermediates in the gas phase oxidation of hydrocarbons, and their hydrolysis products have been observed in ambient aerosols. To evaluate the role of epoxides in the formation of secondary organic aerosols (SOA), the kinetics and mechanism of heterogeneous reactions of two model epoxides, isoprene oxide and α-pinene oxide, with sulfuric acid, ammonium bisulfate, and ammonium sulfate have been investigated using complementary experimental techniques. Kinetic experiments using a fast flow reactor coupled to an ion drift-chemical ionization mass spectrometer (ID-CIMS) show a fast irreversible loss of the epoxides with the uptake coefficients (γ) of (1.7 ± 0.1) × 10(-2) and (4.6 ± 0.3) × 10(-2) for isoprene oxide and α-pinene oxide, respectively, for 90 wt % H(2)SO(4) and at room temperature. Experiments using attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) reveal that diols are the major products in ammonium bisulfate and dilute H(2)SO(4) (65 wt %), acetals are formed from isoprene oxide, whereas organosulfates are produced from α-pinene oxide. The reaction of the epoxides with ammonium sulfate is slow and no products are observed. The epoxide reactions using bulk samples and Nuclear Magnetic Resonance (NMR) spectroscopy reveal the presence of diols as the major products for isoprene oxide, accompanied by aldehyde formation. For α-pinene oxide, organosulfate formation is observed with a yield increasing with the acidity. Large yields of organosulfates in all NMR experiments with α-pinene oxide are attributed to the kinetic isotope effect (KIE) from the use of deuterated sulfuric acid and water. Our results suggest that acid-catalyzed hydrolysis of epoxides results in the formation of a wide range of products, and some of the products have low volatility and contribute to SOA growth under ambient conditions prevailing in the urban atmosphere.

  4. Fast Heterogeneous Relaxation Near The Glass Transition

    Science.gov (United States)

    Russina, Margarita

    2000-03-01

    More than a decade ago inelastic neutron scattering studies revealed a surprising characteristic feature in the atomic dynamics near the glass transition, which was often called the betta-process, with reference to predictions of the mode coupling theory (MCT). This process appears on the ps time scale, i.e. fast compared to the ordinary flow viscosity governed relaxation and slow compared to usual atomic vibrations, and its nature remained a puzzle over the years. Although inelastic neutron scattering is ideally suited to observe dynamics on microscopic time and length scales, experimental difficulties due to strong multiple scattering effects prevented the exploration of the spatial character of this process. By a new experimental approach to correct for these spurious contributions with a high precision, we were now able to extend the spatial domain of our observations from just about nearest neighbor atomic distances by close to an order of magnitude larger ones, which length scale includes that of the intermediate range order, which can be expected to reveal most sensitively collective, as opposed to the local, behavior. Our results in the fragile glass forming liquid Ca-K-NO3 show, that the betta-process is a first fast step of the structural relaxation, which confirms a most fundamental prediction of MCT. Furthermore, by investigating the Debye-Waller factor associated with this process, we found that its geometrical nature corresponds to quasi-rigid, correlated displacement of mobile groups of atoms, which move much faster than the ordinary flow of the bulk of the supercooled liquid. This is the first direct experimental evidence for the existence of heterogeneous fast flow processes similar to the string-flow motion recently observed in molecular dynamic simulations of model liquids close to the glass transition.

  5. Thermal maps of gases in heterogeneous reactions

    Science.gov (United States)

    Jarenwattananon, Nanette N.; Glöggler, Stefan; Otto, Trenton; Melkonian, Arek; Morris, William; Burt, Scott R.; Yaghi, Omar M.; Bouchard, Louis-S.

    2013-10-01

    More than 85 per cent of all chemical industry products are made using catalysts, the overwhelming majority of which are heterogeneous catalysts that function at the gas-solid interface. Consequently, much effort is invested in optimizing the design of catalytic reactors, usually by modelling the coupling between heat transfer, fluid dynamics and surface reaction kinetics. The complexity involved requires a calibration of model approximations against experimental observations, with temperature maps being particularly valuable because temperature control is often essential for optimal operation and because temperature gradients contain information about the energetics of a reaction. However, it is challenging to probe the behaviour of a gas inside a reactor without disturbing its flow, particularly when trying also to map the physical parameters and gradients that dictate heat and mass flow and catalytic efficiency. Although optical techniques and sensors have been used for that purpose, the former perform poorly in opaque media and the latter perturb the flow. NMR thermometry can measure temperature non-invasively, but traditional approaches applied to gases produce signals that depend only weakly on temperature are rapidly attenuated by diffusion or require contrast agents that may interfere with reactions. Here we present a new NMR thermometry technique that circumvents these problems by exploiting the inverse relationship between NMR linewidths and temperature caused by motional averaging in a weak magnetic field gradient. We demonstrate the concept by non-invasively mapping gas temperatures during the hydrogenation of propylene in reactors packed with metal nanoparticles and metal-organic framework catalysts, with measurement errors of less than four per cent of the absolute temperature. These results establish our technique as a non-invasive tool for locating hot and cold spots in catalyst-packed gas-solid reactors, with unprecedented capabilities for testing

  6. Thermal maps of gases in heterogeneous reactions.

    Science.gov (United States)

    Jarenwattananon, Nanette N; Glöggler, Stefan; Otto, Trenton; Melkonian, Arek; Morris, William; Burt, Scott R; Yaghi, Omar M; Bouchard, Louis-S

    2013-10-24

    More than 85 per cent of all chemical industry products are made using catalysts, the overwhelming majority of which are heterogeneous catalysts that function at the gas-solid interface. Consequently, much effort is invested in optimizing the design of catalytic reactors, usually by modelling the coupling between heat transfer, fluid dynamics and surface reaction kinetics. The complexity involved requires a calibration of model approximations against experimental observations, with temperature maps being particularly valuable because temperature control is often essential for optimal operation and because temperature gradients contain information about the energetics of a reaction. However, it is challenging to probe the behaviour of a gas inside a reactor without disturbing its flow, particularly when trying also to map the physical parameters and gradients that dictate heat and mass flow and catalytic efficiency. Although optical techniques and sensors have been used for that purpose, the former perform poorly in opaque media and the latter perturb the flow. NMR thermometry can measure temperature non-invasively, but traditional approaches applied to gases produce signals that depend only weakly on temperature are rapidly attenuated by diffusion or require contrast agents that may interfere with reactions. Here we present a new NMR thermometry technique that circumvents these problems by exploiting the inverse relationship between NMR linewidths and temperature caused by motional averaging in a weak magnetic field gradient. We demonstrate the concept by non-invasively mapping gas temperatures during the hydrogenation of propylene in reactors packed with metal nanoparticles and metal-organic framework catalysts, with measurement errors of less than four per cent of the absolute temperature. These results establish our technique as a non-invasive tool for locating hot and cold spots in catalyst-packed gas-solid reactors, with unprecedented capabilities for testing

  7. Representing Topological Relationships Among Heterogeneous Geometry-Collection Features

    Institute of Scientific and Technical Information of China (English)

    Zhi-Nong Zhong; Ning Jing; Luo Chen; Qiu-Yun Wu

    2004-01-01

    Topological relationships between two spatial features represent important knowledge in Geographical Information Systems (GIS). In the last few years, many models that represent topological relationships have been proposed. But these models cannot represent the topological relationships between heterogeneous geometrycollection features, which are composed of different dimensional geometries. In this paper, the formal definition of regular heterogeneous geometrycollection and regularization rules are given. Based on the spatial model, two methods for representing topological relationships between these complex features are proposed. The first method is Dimensionally Extended Nine-Intersection Model Based on Components (DE-9IMBC) that extends Dimensionally Extended Nine-Intersection Model (DE-9IM) and takes into account the topological relationships between components of these complex features. The advantage of DE-9IMBC is that a large number of different topological relationships can be checked. The second method extends the definitions of topological relationships in Open Geodata Interoperability Specification (OpenGIS), and redefines the seven named topological relationships:{Disjoint, Touches, Within, Crosses, Overlaps, Contains and Equal}, to represent the topological relationships between heterogeneous geometrycollection features. It is proven that the seven extended topological relationships are complete and mutually exclusive, and they are suitable for being embedded in spatial query languages.

  8. Representing Topological Relationships Among Heterogeneous Geometry-Collection Features

    Institute of Scientific and Technical Information of China (English)

    Zhi-NongZhong[; NingJing; LuoChen; Qiu-YunWu

    2004-01-01

    Topological relationships between two spatial features represent important knowledge in Geographical Information Systems (GIS). In the last few years, many models that represent topological relationships have been proposed. But these models cannot represent the topological relationships between heterogeneous geometrycollection features, which are composed of different dimensional geometries. In this paper, the formal definition of regular heterogeneous geometrycollection and regularization rules are given. Based on the spatial model, two methods for representing topological relationships between these complex features are proposed. The first method is Dimensionally Extended Nine-Intersection Model Based on Components (DE-9IMBC) that extends Dimensionally Extended Nine-Intersection Model (DE-9IM) and takes into account the topological relationships between components of these complex features. The advantage of DE-9IMBC is that a large number of different topological relationships can be checked. The second method extends the definitions of topological relationships in Open Geodata Interoperability Specification (OpenGIS), and redefines the seven named topological relationships: {Disjoint, Touches, Within, Crosses, Overlaps, Contains and Equal}, to represent the topological relationships between heterogeneous geometrycollection features. It is proven that the seven extended topological relationships are complete and mutually exclusive, and they are suitable for being embedded in spatial query languages.

  9. Metal Catalysts Recycling and Heterogeneous/Homogeneous Catalysis

    Directory of Open Access Journals (Sweden)

    Masahiko Arai

    2015-05-01

    Full Text Available Heterogeneous metal catalysts rather than homogeneous ones are recommended for industrial applications after considering their performance in activity, separation, and recycling [1]. The recycling of metal catalysts is important from economic and environmental points of view. When supported and bulk metal catalysts are used in liquid-phase organic reactions, there is a possibility that active metal species are leaching away into the liquid phases [2,3]. The metal leaching would make it difficult for the catalysts to maintain their desired initial performance for repeated batch reactions and during continuous ones. The metal leaching would also cause some undesired contamination of products by the metal species dissolved in the reaction mixture, and the separation of the metal contaminants would be required to purify the products. Therefore, various novel methods have been proposed so far to immobilize/stabilize the active metal species and to separate/collect/reuse the dissolved metal species [4]. In addition, knowledge on the heterogeneous and homogeneous natures of organic reactions using heterogeneous catalysts is important to discuss their reaction mechanisms and catalytically working active species. [...

  10. Pine invasions in treeless environments: dispersal overruns microsite heterogeneity.

    Science.gov (United States)

    Pauchard, Aníbal; Escudero, Adrián; García, Rafael A; de la Cruz, Marcelino; Langdon, Bárbara; Cavieres, Lohengrin A; Esquivel, Jocelyn

    2016-01-01

    Understanding biological invasions patterns and mechanisms is highly needed for forecasting and managing these processes and their negative impacts. At small scales, ecological processes driving plant invasions are expected to produce a spatially explicit pattern driven by propagule pressure and local ground heterogeneity. Our aim was to determine the interplay between the intensity of seed rain, using distance to a mature plantation as a proxy, and microsite heterogeneity in the spreading of Pinus contorta in the treeless Patagonian steppe. Three one-hectare plots were located under different degrees of P. contorta invasion (Coyhaique Alto, 45° 30'S and 71° 42'W). We fitted three types of inhomogeneous Poisson models to each pine plot in an attempt for describing the observed pattern as accurately as possible: the "dispersal" models, "local ground heterogeneity" models, and "combined" models, using both types of covariates. To include the temporal axis in the invasion process, we analyzed both the pattern of young and old recruits and also of all recruits together. As hypothesized, the spatial patterns of recruited pines showed coarse scale heterogeneity. Early pine invasion spatial patterns in our Patagonian steppe site is not different from expectations of inhomogeneous Poisson processes taking into consideration a linear and negative dependency of pine recruit intensity on the distance to afforestations. Models including ground-cover predictors were able to describe the point pattern process only in a couple of cases but never better than dispersal models. This finding concurs with the idea that early invasions depend more on seed pressure than on the biotic and abiotic relationships seed and seedlings establish at the microsite scale. Our results show that without a timely and active management, P. contorta will invade the Patagonian steppe independently of the local ground-cover conditions.

  11. Synchronization for heterogeneous networks of introspective right-invertible agents with uniform constant communication delay

    NARCIS (Netherlands)

    Wang, Xu; Saberi, Ali; Stoorvogel, Anton A.; Grip, H°avard Fjær; Yang, Tao

    2013-01-01

    This paper studies output synchronization and regulation problem for heterogeneous networks of introspective right-invertible agents with uniform constant communication delay. A decentralized design based on shaping the agent dynamics using their self-knowledge and structural properties is developed

  12. Chemistry, spectroscopy and the role of supported vanadium oxides in heterogeneous catalysis

    NARCIS (Netherlands)

    Weckhuysen, B.M.; Keller, D.E.

    2003-01-01

    Supported vanadium oxide catalysts are active in a wide range of applications. In this review, an overview is given of the current knowledge available about vanadium oxide-based catalysts. The review starts with the importance of vanadium in heterogeneous catalysis, a discussion of the molecular str

  13. Impact of Pathogen Population Heterogeneity and Stress-Resistant Variants on Food Safety

    NARCIS (Netherlands)

    Abee, T.; Koomen, J.; Metselaar, K.I.; Zwietering, M.H.; Besten, Den H.M.W.

    2016-01-01

    This review elucidates the state-of-the-art knowledge about pathogen population heterogeneity and describes the genotypic and phenotypic analyses of persister subpopulations and stress-resistant variants. The molecular mechanisms underlying the generation of persister phenotypes and genetic varia

  14. Synthesizing Knowledge on Internet of Things (IoT)

    DEFF Research Database (Denmark)

    Liu, Fei; Tan, Chee-Wee; Lim, Eric T. K.

    2016-01-01

    Research on Internet of Things (IoT) has been booming for past couple of years due to technological advances and its potential for application. Nonetheless, the rapid growth of IoT articles as well as the heterogeneous nature of IoT pose challenges in synthesizing prior research on the phenomenon...

  15. One knowledge base or many knowledge pools?

    DEFF Research Database (Denmark)

    Lundvall, Bengt-Åke

    It is increasingly realized that knowledge is the most important resource and that learning is the most important process in the economy. Sometimes this is expressed by coining the current era as characterised by a ‘knowledge based economy'. But this concept might be misleading by indicating...... that there is one common knowledge base on which economic activities can be built. In this paper we argue that it is more appropriate to see the economy as connecting to different ‘pools of knowledge'. The argument is built upon a conceptual framework where we make distinctions between private/public, local....../global, individual/collective and tacit/codified knowledge. The purpose is both ‘academic' and practical. Our analysis demonstrates the limits of a narrowly economic perspective on knowledge and we show that these distinctions have important implications both for innovation policy and for management of innovation....

  16. Direct optimization of heterogeneous systems in electrical engineering; Optimisation directe de systemes heterogenes en Genie electrique

    Energy Technology Data Exchange (ETDEWEB)

    Fefermann, Y.

    2002-12-15

    Today, a global viewpoint in the design of devices called 'system approach', is imposed by couplings between physical fields and multiple interactions between sub-systems. Indeed, concerning static and electromechanical converters, or control systems, numerous issues of design are more and more mastered when each element is separately conceived. However, as soon as designing an heterogeneous system seen as a 'complex of elements in interaction' is at stake, arises the problem of the global optimization with respect to multiple criteria which characterize the quality of its behavior. The works realized in this thesis concern the multi-criteria optimization of systems by direct methods not related to the analytical calculation of the gradient. These techniques are applied to a typical electrical vehicle. We propose for each of the sub-systems a modeling adapted to the problem. In particular, an original method based on variations by similarity was elaborated for the design procedure of the PMSM machine. The parameters (DC supply voltage, geometrical parameters,...) can be fitted to all the system levels. They optimize performance criteria: minimization of the losses, of the embedded mass,... The methods of optimization used to resolve this non-linear problem are the Nelder and Mead's Simplex and Hooke and Jeeves algorithm. The constraints of the problem are treated by penalties (exact and quadratic) and a simple heuristic is proposed allowing a constraints normalization and a better algorithm convergence. The optimization results enable to underline the couplings between the various sub-systems, a significant point of the analysis. They have also shown the interest of a global approach in the design and the study of electric systems. (author)

  17. The effects of physical and geochemical heterogeneities on hydro-geochemical transport and effective reaction rates.

    Science.gov (United States)

    Atchley, Adam L; Navarre-Sitchler, Alexis K; Maxwell, Reed M

    2014-09-01

    The role of coupled physical and geochemical heterogeneities in hydro-geochemical transport is investigated by simulating three-dimensional transport in a heterogeneous system with kinetic mineral reactions. Ensembles of 100 physically heterogeneous realizations were simulated for three geochemical conditions: 1) spatially homogeneous reactive mineral surface area, 2) reactive surface area positively correlated to hydraulic heterogeneity, and 3) reactive surface area negatively correlated to hydraulic heterogeneity. Groundwater chemistry and the corresponding effective reaction rates were calculated at three transverse planes to quantify differences in plume evolution due to heterogeneity in mineral reaction rates and solute residence time (τ). The model is based on a hypothetical CO2 intrusion into groundwater from a carbon capture utilization and storage (CCUS) operation where CO2 dissolution and formation of carbonic acid created geochemical dis-equilibrium between fluids and the mineral galena that resulted in increased aqueous lead (Pb(2+)) concentrations. Calcite dissolution buffered the pH change and created conditions of galena oversaturation, which then reduced lead concentrations along the flow path. Near the leak kinetic geochemical reactions control the release of solutes into the fluid, but further along the flow path mineral solubility controls solute concentrations. Simulation results demonstrate the impact of heterogeneous distribution of geochemical reactive surface area in coordination with physical heterogeneity on the effective reaction rate (Krxn,eff) and Pb(2+) concentrations within the plume. Dissimilarities between ensemble Pb(2+) concentration and Krxn,eff are attributed to how geochemical heterogeneity affects the time (τeq) and therefore advection distance (Leq) required for the system to re-establish geochemical equilibrium. Only after geochemical equilibrium is re-established, Krxn,eff and Pb(2+) concentrations are the same for all

  18. Knowledge Repository for Fmea Related Knowledge

    Science.gov (United States)

    Cândea, Gabriela Simona; Kifor, Claudiu Vasile; Cândea, Ciprian

    2014-11-01

    This paper presents innovative usage of knowledge system into Failure Mode and Effects Analysis (FMEA) process using the ontology to represent the knowledge. Knowledge system is built to serve multi-projects work that nowadays are in place in any manufacturing or services provider, and knowledge must be retained and reused at the company level and not only at project level. The system is following the FMEA methodology and the validation of the concept is compliant with the automotive industry standards published by Automotive Industry Action Group, and not only. Collaboration is assured trough web-based GUI that supports multiple users access at any time

  19. One knowledge base or many knowledge pools?

    DEFF Research Database (Denmark)

    Lundvall, Bengt-Åke

    /global, individual/collective and tacit/codified knowledge. The purpose is both ‘academic' and practical. Our analysis demonstrates the limits of a narrowly economic perspective on knowledge and we show that these distinctions have important implications both for innovation policy and for management of innovation.......It is increasingly realized that knowledge is the most important resource and that learning is the most important process in the economy. Sometimes this is expressed by coining the current era as characterised by a ‘knowledge based economy'. But this concept might be misleading by indicating...

  20. Ontology-based knowledge discovery in pharmacogenomics.

    Science.gov (United States)

    Coulet, Adrien; Smaïl-Tabbone, Malika; Napoli, Amedeo; Devignes, Marie-Dominique

    2011-01-01

    One current challenge in biomedicine is to analyze large amounts of complex biological data for extracting domain knowledge. This work holds on the use of knowledge-based techniques such as knowledge discovery (KD) and knowledge representation (KR) in pharmacogenomics, where knowledge units represent genotype-phenotype relationships in the context of a given treatment. An objective is to design knowledge base (KB, here also mentioned as an ontology) and then to use it in the KD process itself. A method is proposed for dealing with two main tasks: (1) building a KB from heterogeneous data related to genotype, phenotype, and treatment, and (2) applying KD techniques on knowledge assertions for extracting genotype-phenotype relationships. An application was carried out on a clinical trial concerned with the variability of drug response to montelukast treatment. Genotype-genotype and genotype-phenotype associations were retrieved together with new associations, allowing the extension of the initial KB. This experiment shows the potential of KR and KD processes, especially for designing KB, checking KB consistency, and reasoning for problem solving.

  1. Purchasing Power Parity and Heterogeneous Mean Reversion

    NARCIS (Netherlands)

    C.G. Koedijk (Kees); B. Tims (Ben); M.A. van Dijk (Mathijs)

    2005-01-01

    textabstractThis paper analyzes the properties of multivariate tests of purchasing power parity (PPP) that fail to take heterogeneity in the speed of mean reversion across real exchange rates into account. We compare the performance of homogeneous and heterogeneous unit root testing methodologies.

  2. Fixed export cost heterogeneity, trade and welfare

    DEFF Research Database (Denmark)

    Jørgensen, Jan Guldager; Schröder, Philipp J.H.

    2008-01-01

    Recent literature on the workhorse model of intra-industry trade has explored heterogeneous cost structures at the firm level. These approaches have proven to add realism and predictive power. This paper presents a new and simple heterogeneous-firms specification. We develop a symmetric two...

  3. Hybrid Interconnect Design for Heterogeneous Hardware Accelerators

    NARCIS (Netherlands)

    Pham-Quoc Cuong, P.

    2015-01-01

    Heterogeneous multicore systems are becoming increasingly important as the need for computation power grows, especially when we are entering into the big data era. As one of the main trends in heterogeneous multicore, hardware accelerator systems provide application specific hardware circuits and

  4. Modelling income processes with lots of heterogeneity

    DEFF Research Database (Denmark)

    Browning, Martin; Ejrnæs, Mette; Alvarez, Javier

    2010-01-01

    this observable homogeneity, we find more latent heterogeneity than previous investigators. We show that allowance for heterogeneity makes substantial differences to estimates of model parameters and to outcomes of interest. Additionally, we find strong evidence against the hypothesis that any worker has a unit...

  5. Characterizing heterogeneous cellular responses to perturbations.

    Science.gov (United States)

    Slack, Michael D; Martinez, Elisabeth D; Wu, Lani F; Altschuler, Steven J

    2008-12-01

    Cellular populations have been widely observed to respond heterogeneously to perturbation. However, interpreting the observed heterogeneity is an extremely challenging problem because of the complexity of possible cellular phenotypes, the large dimension of potential perturbations, and the lack of methods for separating meaningful biological information from noise. Here, we develop an image-based approach to characterize cellular phenotypes based on patterns of signaling marker colocalization. Heterogeneous cellular populations are characterized as mixtures of phenotypically distinct subpopulations, and responses to perturbations are summarized succinctly as probabilistic redistributions of these mixtures. We apply our method to characterize the heterogeneous responses of cancer cells to a panel of drugs. We find that cells treated with drugs of (dis-)similar mechanism exhibit (dis-)similar patterns of heterogeneity. Despite the observed phenotypic diversity of cells observed within our data, low-complexity models of heterogeneity were sufficient to distinguish most classes of drug mechanism. Our approach offers a computational framework for assessing the complexity of cellular heterogeneity, investigating the degree to which perturbations induce redistributions of a limited, but nontrivial, repertoire of underlying states and revealing functional significance contained within distinct patterns of heterogeneous responses.

  6. Bandwidth sharing with heterogeneous service requirements

    NARCIS (Netherlands)

    Borst, S.C.; Núñez Queija, R.; Zwart, A.P.

    2003-01-01

    We consider a system with two heterogeneous traffic classes. The users from both classes randomly generate service requests, one class having light-tailed properties, the other one exhibiting heavy-tailed characteristics. The heterogeneity in service requirements reflects the extreme variability in

  7. The composition of heterogeneous control laws

    Science.gov (United States)

    Kuipers, Benjamin; Astrom, Karl

    1991-01-01

    The fuzzy control literature and industrial practice provide certain nonlinear methods for combining heterogeneous control laws, but these methods have been very difficult to analyze theoretically. An alternate formulation and extension of this approach is presented that has several practical and theoretical benefits. An example of heterogeneous control is given and two alternate analysis methods are presented.

  8. Surface temperature excess in heterogeneous catalysis

    NARCIS (Netherlands)

    Zhu, L.

    2005-01-01

    In this dissertation we study the surface temperature excess in heterogeneous catalysis. For heterogeneous reactions, such as gas-solid catalytic reactions, the reactions take place at the interfaces between the two phases: the gas and the solid catalyst. Large amount of reaction heats are released

  9. Optimization of Hierarchically Scheduled Heterogeneous Embedded Systems

    DEFF Research Database (Denmark)

    Pop, Traian; Pop, Paul; Eles, Petru;

    2005-01-01

    We present an approach to the analysis and optimization of heterogeneous distributed embedded systems. The systems are heterogeneous not only in terms of hardware components, but also in terms of communication protocols and scheduling policies. When several scheduling policies share a resource...

  10. Hybrid Interconnect Design for Heterogeneous Hardware Accelerators

    NARCIS (Netherlands)

    Pham-Quoc Cuong, P.

    2015-01-01

    Heterogeneous multicore systems are becoming increasingly important as the need for computation power grows, especially when we are entering into the big data era. As one of the main trends in heterogeneous multicore, hardware accelerator systems provide application specific hardware circuits and ar

  11. Heterogeneity in Health Care Computing Environments

    OpenAIRE

    Sengupta, Soumitra

    1989-01-01

    This paper discusses issues of heterogeneity in computer systems, networks, databases, and presentation techniques, and the problems it creates in developing integrated medical information systems. The need for institutional, comprehensive goals are emphasized. Using the Columbia-Presbyterian Medical Center's computing environment as the case study, various steps to solve the heterogeneity problem are presented.

  12. Understanding the Executive Functioning Heterogeneity in Schizophrenia

    Science.gov (United States)

    Raffard, Stephane; Bayard, Sophie

    2012-01-01

    Schizophrenia is characterized by heterogeneous brain abnormalities involving cerebral regions implied in the executive functioning. The dysexecutive syndrome is one of the most prominent and functionally cognitive features of schizophrenia. Nevertheless, it is not clear to what extend executive deficits are heterogeneous in schizophrenia…

  13. Towards an Organizational Economics of Heterogeneous Capabilities

    DEFF Research Database (Denmark)

    Foss, Nicolai Juul

    The notion of “capability” has long been influential in management research as an approach to address firm-level heterogeneity and heterogeneity in competitive outcomes. I discuss how recent advances in economics may allow for a more rigorous understanding and measurement of capability that take...

  14. Surface temperature excess in heterogeneous catalysis

    NARCIS (Netherlands)

    Zhu, L.

    2005-01-01

    In this dissertation we study the surface temperature excess in heterogeneous catalysis. For heterogeneous reactions, such as gas-solid catalytic reactions, the reactions take place at the interfaces between the two phases: the gas and the solid catalyst. Large amount of reaction heats are released

  15. Functional Heterogeneity and Senior Management Team Effectiveness

    Science.gov (United States)

    Benoliel, Pascale; Somech, Anit

    2016-01-01

    Purpose: There has been an increasing trend toward the creation of senior management teams (SMTs) which are characterized by a high degree of functional heterogeneity. Although such teams may create better linkages to information, along with the benefits of functional heterogeneity comes the potential for conflicts that stem from the value…

  16. Understanding the Executive Functioning Heterogeneity in Schizophrenia

    Science.gov (United States)

    Raffard, Stephane; Bayard, Sophie

    2012-01-01

    Schizophrenia is characterized by heterogeneous brain abnormalities involving cerebral regions implied in the executive functioning. The dysexecutive syndrome is one of the most prominent and functionally cognitive features of schizophrenia. Nevertheless, it is not clear to what extend executive deficits are heterogeneous in schizophrenia…

  17. Monetary policy, banking and heterogeneous agents

    NARCIS (Netherlands)

    Wolski, M.

    2012-01-01

    The influence of heterogeneous expectations on monetary policy performance has gained a lot of attention in the recent years. It proved to be an important factor that, under some circumstances, may even destabilize the economy (Massaro, 2012). This paper investigates the phenomenon of heterogeneous

  18. Monetary policy, banking and heterogeneous agents

    NARCIS (Netherlands)

    Wolski, M.

    2012-01-01

    The influence of heterogeneous expectations on monetary policy performance has gained a lot of attention in the recent years. It proved to be an important factor that, under some circumstances, may even destabilize the economy (Massaro, 2012). This paper investigates the phenomenon of heterogeneous

  19. Knowledge and Its Enemies

    Science.gov (United States)

    Kruk, Miroslav

    2007-01-01

    As libraries are the physical manifestations of knowledge, some refection about the concept of knowledge would not be unjustified. In modern societies, knowledge plays such a central role that it requires some effort and imagination to understand on what grounds knowledge could be rejected. Karl Popper wrote about the open society and its enemies.…

  20. Knowledge at Work.

    Science.gov (United States)

    Scribner, Sylvia

    1985-01-01

    Activity theory posits that culturally organized actions guide the acquisition and organization of knowledge. This theory was applied to the organization of knowledge within a large milk processing plant. The dairy was found to be organized by social knowledge, yet individuals creatively synthesized several domains of knowledge to organize their…

  1. The Heterogeneity of Juvenile Myositis

    Science.gov (United States)

    Rider, Lisa G.

    2007-01-01

    Juvenile myositis is a heterogeneous group of systemic autoimmune diseases, in which clinical and serologic subgroups result in subsets of patients with distinct clinical manifestations, disease courses, immunogenetic associations, responses to therapy, and prognoses. A newly identified autoantibody of unknown specificity, anti-p155, is myositis-associated and seen in up to 20 – 30% of juvenile and adult DM patients. HLA DRB1*0301 and its linked allele DQA1*0501 have been identified as the major immunogenetic risk factor for juvenile and adult DM in both European- and African- American patients, and DQA1*0301 is an additional risk factor in European American patients. Several DQA1 alleles also are protective for juvenile DM. Environmental risk factors are poorly understood, but growing evidence suggests a role for infectious agents and ultraviolet radiation. The current therapy of juvenile DM consists of corticosteroids and other immunosuppressive agents, with the adjunctive treatment of cutaneous manifestations and rehabilitation. Therapeutic trials of biologic agents, including anti-TNFα and anti-CD20, may aid in developing promising new therapies for these disorders. PMID:17317616

  2. Collective foraging in heterogeneous landscapes

    CERN Document Server

    Bhattacharya, Kunal

    2013-01-01

    Animals foraging alone are hypothesized to optimize the encounter rates with resources through L\\'evy walks. However, the issue of how the interactions between multiple foragers influence their search efficiency is still not completely understood. To address this, we consider a model to study the optimal strategy for a group of foragers searching for targets distributed heterogeneously. In our model foragers move on a square lattice containing immobile but regenerative targets. At any instant a forager is able to detect only those targets that happen to be in the same site. However, we allow the foragers to have information about the state of other foragers. A forager who has not detected any target walks towards the nearest location, where another forager has detected a target, with probability $\\exp{\\left(-\\alpha d\\right)}$, where $d$ is the distance and $\\alpha$ is a parameter. The model reveals that neither overcrowding ($\\alpha\\to 0$) nor independent searching ($\\alpha\\to\\infty$) is beneficial for the gr...

  3. Operating a heterogeneous telescope network

    Science.gov (United States)

    Allan, Alasdair; Bischoff, Karsten; Burgdorf, Martin; Cavanagh, Brad; Christian, Damien; Clay, Neil; Dickens, Rob; Economou, Frossie; Fadavi, Mehri; Frazer, Stephen; Granzer, Thomas; Grosvenor, Sandy; Hessman, Frederic V.; Jenness, Tim; Koratkar, Anuradha; Lehner, Matthew; Mottram, Chris; Naylor, Tim; Saunders, Eric S.; Solomos, Nikolaos; Steele, Iain A.; Tuparev, Georg; Vestrand, W. Thomas; White, Robert R.; Yost, Sarah

    2006-06-01

    In the last few years the ubiquitous availability of high bandwidth networks has changed the way both robotic and non-robotic telescopes operate, with single isolated telescopes being integrated into expanding "smart" telescope networks that can span continents and respond to transient events in seconds. The Heterogeneous Telescope Networks (HTN)* Consortium represents a number of major research groups in the field of robotic telescopes, and together we are proposing a standards based approach to providing interoperability between the existing proprietary telescope networks. We further propose standards for interoperability, and integration with, the emerging Virtual Observatory. We present the results of the first interoperability meeting held last year and discuss the protocol and transport standards agreed at the meeting, which deals with the complex issue of how to optimally schedule observations on geographically distributed resources. We discuss a free market approach to this scheduling problem, which must initially be based on ad-hoc agreements between the participants in the network, but which may eventually expand into a electronic market for the exchange of telescope time.

  4. Topology Optimisation for Coupled Convection Problems

    DEFF Research Database (Denmark)

    Alexandersen, Joe; Andreasen, Casper Schousboe; Aage, Niels

    conduction governs in the solid parts of the design domain and couples to convection-dominated heat transfer to a surrounding fluid. Both loosely coupled and tightly coupled problems are considered. The loosely coupled problems are convection-diffusion problems, based on an advective velocity field from......The work focuses on applying topology optimisation to forced and natural convection problems in fluid dynamics and conjugate (fluid-structure) heat transfer. To the authors' knowledge, topology optimisation has not yet been applied to natural convection flow problems in the published literature...... and the current work is thus seen as contributing new results to the field. In the literature, most works on the topology optimisation of weakly coupled convection-diffusion problems focus on the temperature distribution of the fluid, but a selection of notable exceptions also focusing on the temperature...

  5. Heterogeneity assessment of functional T cell avidity

    Science.gov (United States)

    Ioannidou, Kalliopi; Baumgaertner, Petra; Gannon, Philippe O.; Speiser, Michel F.; Allard, Mathilde; Hebeisen, Michael; Rufer, Nathalie; Speiser, Daniel E.

    2017-01-01

    The potency of cellular immune responses strongly depends on T cell avidity to antigen. Yet, functional avidity measurements are rarely performed in patients, mainly due to the technical challenges of characterizing heterogeneous T cells. The mean functional T cell avidity can be determined by the IFN-γ Elispot assay, with titrated amounts of peptide. Using this assay, we developed a method revealing the heterogeneity of functional avidity, represented by the steepness/hillslope of the peptide titration curve, documented by proof of principle experiments and mathematical modeling. Our data show that not only natural polyclonal CD8 T cell populations from cancer patients, but also monoclonal T cells differ strongly in their heterogeneity of functional avidity. Interestingly, clones and polyclonal cells displayed comparable ranges of heterogeneity. We conclude that besides the mean functional avidity, it is feasible and useful to determine its heterogeneity (hillslope) for characterizing T cell responses in basic research and patient investigation. PMID:28287160

  6. Design Technology for Heterogeneous Embedded Systems

    CERN Document Server

    O'Connor, Ian; Piguet, Christian

    2012-01-01

    Designing technology to address the problem of heterogeneous embedded systems, while remaining compatible with standard “More Moore” flows, i.e. capable of handling simultaneously both silicon complexity and system complexity, represents one of the most important challenges facing the semiconductor industry today. While the micro-electronics industry has built its own specific design methods to focus mainly on the management of complexity through the establishment of abstraction levels, the emergence of device heterogeneity requires new approaches enabling the satisfactory design of physically heterogeneous embedded systems for the widespread deployment of such systems. This book, compiled largely from a set of contributions from participants of past editions of the Winter School on Heterogeneous Embedded Systems Design Technology (FETCH), proposes a broad and holistic overview of design techniques used to tackle the various facets of heterogeneity in terms of technology and opportunities at the physical ...

  7. Heterogeneity in isogenic populations of microorganisms

    DEFF Research Database (Denmark)

    Pedersen, Anne Egholm

    values for quantifiable variables are used. The reproducibility of an experiment could thus be affected by the presence of subpopulations or high levels of phenotypic variations. Ole Maaløe and colleagues did in the late 1950’ties observe that the growth rate, RNA, DNA and protein synthesis and cell...... of heterogeneity was slightly higher at intermediate inducer concentrations. Additionally, the effect of thermal stress on phenotypic heterogeneity was addressed by inflicting a heat stress to the B. subtilis GFP reporter strain. The increase in incubation temperature transient increased population heterogeneity....... Heterogeneity was investigated on a population level using a quantitative analysis of phenotypic variation in methicillin-resistant Staphylococcus aureus (MRSA). The results obtained showed that the physiological state of the culture used for the analysis affected the phenotypic variation, as heterogeneity...

  8. RDF SKETCH MAPS - KNOWLEDGE COMPLEXITY REDUCTION FOR PRECISION MEDICINE ANALYTICS.

    Science.gov (United States)

    Thanintorn, Nattapon; Wang, Juexin; Ersoy, Ilker; Al-Taie, Zainab; Jiang, Yuexu; Wang, Duolin; Verma, Megha; Joshi, Trupti; Hammer, Richard; Xu, Dong; Shin, Dmitriy

    2016-01-01

    Realization of precision medicine ideas requires significant research effort to be able to spot subtle differences in complex diseases at the molecular level to develop personalized therapies. It is especially important in many cases of highly heterogeneous cancers. Precision diagnostics and therapeutics of such diseases demands interrogation of vast amounts of biological knowledge coupled with novel analytic methodologies. For instance, pathway-based approaches can shed light on the way tumorigenesis takes place in individual patient cases and pinpoint to novel drug targets. However, comprehensive analysis of hundreds of pathways and thousands of genes creates a combinatorial explosion, that is challenging for medical practitioners to handle at the point of care. Here we extend our previous work on mapping clinical omics data to curated Resource Description Framework (RDF) knowledge bases to derive influence diagrams of interrelationships of biomarker proteins, diseases and signal transduction pathways for personalized theranostics. We present RDF Sketch Maps - a computational method to reduce knowledge complexity for precision medicine analytics. The method of RDF Sketch Maps is inspired by the way a sketch artist conveys only important visual information and discards other unnecessary details. In our case, we compute and retain only so-called RDF Edges - places with highly important diagnostic and therapeutic information. To do this we utilize 35 maps of human signal transduction pathways by transforming 300 KEGG maps into highly processable RDF knowledge base. We have demonstrated potential clinical utility of RDF Sketch Maps in hematopoietic cancers, including analysis of pathways associated with Hairy Cell Leukemia (HCL) and Chronic Myeloid Leukemia (CML) where we achieved up to 20-fold reduction in the number of biological entities to be analyzed, while retaining most likely important entities. In experiments with pathways associated with HCL a generated RDF

  9. Knowledge, perception and attitude of infertile women in Benin City ...

    African Journals Online (AJOL)

    Knowledge, perception and attitude of infertile women in Benin City, Nigeria to the ... has revolutionalized the management of couples with long standing infertility. ... METHODS: This was a questionnaire based survey of 178 infertile patients ...

  10. Exploring Knowledge Governance

    DEFF Research Database (Denmark)

    Foss, Nicolai Juul; Mahoney, Joseph T

    Knowledge governance is characterized as a distinctive research subject, the understanding of which cuts across diverse fields in management. In particular, it represents an intersection of knowledge management, strategic management, and theories of the firm. Knowledge governance considers how...... deployment of governance mechanisms influences knowledge processes: sharing, retaining, and creating knowledge. We survey the papers in this volume of the special issue, and discuss the remaining research challenges....

  11. Knowledge Management and Innovation

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The 21 st century is an era of knowledge, know le dge is said to be particularly important. Knowledge and information have become the economy's primary raw material and its most important outcome. Under increas ingly competitive pressure, many enterprises are examining how they can better m anage their knowledge. During the last years, another concept has gained increas ing interest: knowledge management. The emerging field of knowledge management a ddresses the broad processes of locating, organizing, ...

  12. Knowledge Service Engineering Handbook

    CERN Document Server

    Kantola, Jussi

    2012-01-01

    Covering the emerging field of knowledge service engineering, this groundbreaking handbook outlines how to acquire and utilize knowledge in the 21st century. Drawn on the expertise of the founding faculty member of the world's first university knowledge engineering service department, this book describes what knowledge services engineering means and how it is different from service engineering and service production. Presenting multiple cultural aspects including US, Finnish, and Korean, this handbook provides engineering, systemic, industry, and consumer use viewpoints to knowledge service sy

  13. Action potential duration heterogeneity of cardiac tissue can be evaluated from cell properties using Gaussian Green's function approach.

    Directory of Open Access Journals (Sweden)

    Arne Defauw

    Full Text Available Action potential duration (APD heterogeneity of cardiac tissue is one of the most important factors underlying initiation of deadly cardiac arrhythmias. In many cases such heterogeneity can be measured at tissue level only, while it originates from differences between the individual cardiac cells. The extent of heterogeneity at tissue and single cell level can differ substantially and in many cases it is important to know the relation between them. Here we study effects from cell coupling on APD heterogeneity in cardiac tissue in numerical simulations using the ionic TP06 model for human cardiac tissue. We show that the effect of cell coupling on APD heterogeneity can be described mathematically using a Gaussian Green's function approach. This relates the problem of electrotonic interactions to a wide range of classical problems in physics, chemistry and biology, for which robust methods exist. We show that, both for determining effects of tissue heterogeneity from cell heterogeneity (forward problem as well as for determining cell properties from tissue level measurements (inverse problem, this approach is promising. We illustrate the solution of the forward and inverse problem on several examples of 1D and 2D systems.

  14. Why Explicit Knowledge Cannot Become Implicit Knowledge

    Science.gov (United States)

    VanPatten, Bill

    2016-01-01

    In this essay, I review one of the conclusions in Lindseth (2016) published in "Foreign Language Annals." That conclusion suggests that explicit learning and practice (what she called form-focused instruction) somehow help the development of implicit knowledge (or might even become implicit knowledge). I argue for a different…

  15. Inner magnetosphere coupling: Recent advances

    Science.gov (United States)

    Usanova, M. E.; Shprits, Y. Y.

    2017-01-01

    The dynamics of the inner magnetosphere is strongly governed by the interactions between different plasma populations that are coupled through large-scale electric and magnetic fields, currents, and wave-particle interactions. Inner magnetospheric plasma undergoes self-consistent interactions with global electric and magnetic fields. Waves excited in the inner magnetosphere from unstable particle distributions can provide energy exchange between different particle populations in the inner magnetosphere and affect the ring current and radiation belt dynamics. The ionosphere serves as an energy sink and feeds the magnetosphere back through the cold plasma outflow. The precipitating inner magnetospheric particles influence the ionosphere and upper atmospheric chemistry and affect climate. Satellite measurements and theoretical studies have advanced our understanding of the dynamics of various plasma populations in the inner magnetosphere. However, our knowledge of the coupling processes among the plasmasphere, ring current, radiation belts, global magnetic and electric fields, and plasma waves generated within these systems is still incomplete. This special issue incorporates extended papers presented at the Inner Magnetosphere Coupling III conference held 23-27 March 2015 in Los Angeles, California, USA, and includes modeling and observational contributions addressing interactions within different plasma populations in the inner magnetosphere (plasmasphere, ring current, and radiation belts), coupling between fields and plasma populations, as well as effects of the inner magnetosphere on the ionosphere and atmosphere.

  16. The impact of population heterogeneity on risk estimation in genetic counseling

    Directory of Open Access Journals (Sweden)

    Shaffer Michele L

    2004-06-01

    Full Text Available Abstract Background Genetic counseling has been an important tool for evaluating and communicating disease susceptibility for decades, and it has been applied to predict risks for a wide class of hereditary disorders. Most diseases are complex in nature and are affected by multiple genes and environmental conditions; it is highly likely that DNA tests alone do not define all the genetic factors responsible for a disease, so that persons classified into the same risk group by DNA testing actually could have different disease susceptibilities. Ignorance of population heterogeneity may lead to biased risk estimates, whereas additional information on population heterogeneity may improve the precision of such estimates. Methods Although DNA tests are widely used, few studies have investigated the accuracy of the predicted risks. We examined the impact of population heterogeneity on predicted disease risks by simulation of three different heterogeneity scenarios and studied the precision and accuracy of the risks estimated from a logistic regression model that ignored population heterogeneity. Moreover, we also incorporated information about population heterogeneity into our original model and investigated the resulting improvement in the accuracy of risk estimation. Results We found that heterogeneity in one or more categories could lead to biased estimates not only in the "contaminated" categories but also in other homogeneous categories. Incorporating information about population heterogeneity into the original model greatly improved the accuracy of risk estimation. Conclusions Our findings imply that without thorough knowledge about genetic basis of the disease, risks estimated from DNA tests may be misleading. Caution should be taken when evaluating the predicted risks obtained from genetic counseling. On the other hand, the improved accuracy of risk estimates after incorporating population heterogeneity information into the model did point out a

  17. Finite-time Consensus of Heterogeneous Multi-agent Systems with Linear and Nonlinear Dynamics

    Institute of Scientific and Technical Information of China (English)

    ZHU Ya-Kun; GUAN Xin-Ping; LUO Xiao-Yuan

    2014-01-01

    In this paper, the finite-time consensus problems of heterogeneous multi-agent systems composed of both linear and nonlinear dynamics agents are investigated. Nonlinear consensus protocols are proposed for the heterogeneous multi-agent systems. Some sufficient conditions for the finite-time consensus are established in the leaderless and leader-following cases. The results are also extended to the case where the communication topology is directed and satisfies a detailed balance condition on coupling weights. At last, some simulation results are given to illustrate the effectiveness of the obtained theoretical results.

  18. Decomposing the dynamics of heterogeneous delayed networks with applications to connected vehicle systems.

    Science.gov (United States)

    Szalai, Róbert; Orosz, Gábor

    2013-10-01

    Delay-coupled networks are investigated with nonidentical delay times and the effects of such heterogeneity on the emergent dynamics of complex systems are characterized. A simple decomposition method is presented that decouples the dynamics of the network into node-size modal equations in the vicinity of equilibria. The resulting independent components contain distributed delays that map the spatiotemporal complexity of the system to the time domain. We demonstrate that this approach can be used to reveal physical phenomena in heterogenous vehicular traffic when vehicles are linked via vehicle-to-vehicle communication.

  19. The QCD Running Coupling

    CERN Document Server

    Deur, A; de Teramond, G F

    2016-01-01

    We review the present knowledge for $\\alpha_s$, the fundamental coupling underlying the interactions of quarks and gluons in QCD. The dependence of $\\alpha_s(Q^2)$ on momentum transfer $Q$ encodes the underlying dynamics of hadron physics -from color confinement in the infrared domain to asymptotic freedom at short distances. We review constraints on $\\alpha_s(Q^2)$ at high $Q^2$, as predicted by perturbative QCD, and its analytic behavior at small $Q^2$, based on models of nonperturbative dynamics. In the introductory part of this review, we explain the phenomenological meaning of $\\alpha_s$, the reason for its running, and the challenges facing a complete understanding of its analytic behavior in the infrared domain. In the second, more technical, part of the review, we discuss the behavior of $\\alpha_s(Q^2)$ in the high $Q^2$ domain of QCD. We review how $\\alpha_s$ is defined, including its renormalization scheme dependence, the definition of its renormalization scale, the utility of effective charges, as ...

  20. Molecular modeling of heterogeneous catalysis

    Science.gov (United States)

    Gislason, Jason Joseph

    A novel method for modeling heterogeneous catalysis was developed to further facilitate the understanding of catalytic reactor mechanisms. The method employs molecular dynamics simulations, statistical mechanical, and Unity Bond Index - Quadratic Exponential Potential (UBI-QEP) calculations to calculate the rate constants for reactions on metal surfaces. The primary difficulty of molecular dynamics simulations on metal surfaces has been the lack of reliable reactive potential energy surfaces. We have overcome this through the development of the Normalized Bond Index - Reactive Potential Function (NBI-RPF), which can accurately describe the reaction of adsorbates on metal surfaces. The first calculations of rate constants for a reaction on a metal surface using molecular dynamics simulations are presented. This method is applied to the determination of the mechanism for selective hydrogenation of acetylene in an ethylene rich flow. It was determined that the selectivity for acetylene hydrogenation is attributable to the higher reactivity of acetylene versus ethylene with respect to hydrogenation by molecular hydrogen. It was shown that hydrogen transfer from the carbonaceous layer to acetylene or ethylene is insignificant in the hydrogenation process. Molecular dynamics simulations and molecular mechanics calculations were used to determine the diffusion rate constants for dimethylnaphthalene isomers is mordenite. 2,6-dimethylnaphthalene and 2,7-dimethylnaphthalene were found to have similar diffusion rate constants. Grand canonical Monte Carlo calculations were performed on the competitive adsorption of 2,6-dimethylnaphthalene and 2,7-dimethylnaphthalene in type X zeolites exchanged individually with barium, calcium, potassium, and rubidium ions, calcium exchanged MCM-22, and hydrogen form mordenite (MOR), X zeolite, Y zeolite, hypBEB, ZSM- 12, and MCM-22. These calculations showed that barium exchanged X zeolite was the most selective toward 2

  1. Towards Tuning the Mechanical Properties of Three-Dimensional Collagen Scaffolds Using a Coupled Fiber-Matrix Model

    Directory of Open Access Journals (Sweden)

    Shengmao Lin

    2015-08-01

    Full Text Available Scaffold mechanical properties are essential in regulating the microenvironment of three-dimensional cell culture. A coupled fiber-matrix numerical model was developed in this work for predicting the mechanical response of collagen scaffolds subjected to various levels of non-enzymatic glycation and collagen concentrations. The scaffold was simulated by a Voronoi network embedded in a matrix. The computational model was validated using published experimental data. Results indicate that both non-enzymatic glycation-induced matrix stiffening and fiber network density, as regulated by collagen concentration, influence scaffold behavior. The heterogeneous stress patterns of the scaffold were induced by the interfacial mechanics between the collagen fiber network and the matrix. The knowledge obtained in this work could help to fine-tune the mechanical properties of collagen scaffolds for improved tissue regeneration applications.

  2. Reduction zero-knowledge

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yunlei; DENG Xiaotie; LEE C. H.; ZHU Hong

    2004-01-01

    The nature of zero-knowledge is re-examined and the evidence for the following belief is shown:the classic simulation based definitions of zero-knowledge(simulation zero-knowledge)may be somewhat too strong to include some "nice" protocols in which the malicious verifier seems to learn nothing but we do not know how to construct a zero-knowledge simulator for it.To overcome this problem a new relaxation of zero-knowledge,reduction zero-knowledge,is introduced.It is shown that reduction zero-knowledge just lies between simulation zero-knowledge and witness indistinguishability.Under the assumption of existence of one-way permutations a 4-round public-coin reduction zero-knowledge proof system for NP is presented and in practice this protocol works in 3 rounds since the first verifier's message can be fixed once and for all.

  3. On Granular Knowledge Structures

    CERN Document Server

    Zeng, Yi

    2008-01-01

    Knowledge plays a central role in human and artificial intelligence. One of the key characteristics of knowledge is its structured organization. Knowledge can be and should be presented in multiple levels and multiple views to meet people's needs in different levels of granularities and from different perspectives. In this paper, we stand on the view point of granular computing and provide our understanding on multi-level and multi-view of knowledge through granular knowledge structures (GKS). Representation of granular knowledge structures, operations for building granular knowledge structures and how to use them are investigated. As an illustration, we provide some examples through results from an analysis of proceeding papers. Results show that granular knowledge structures could help users get better understanding of the knowledge source from set theoretical, logical and visual point of views. One may consider using them to meet specific needs or solve certain kinds of problems.

  4. The Knowledge Governance Approach

    DEFF Research Database (Denmark)

    Foss, Nicolai

    2005-01-01

    An attempt is made to characterize a `knowledge governance approach' as a distinctive, emerging field that cuts across the fields of knowledge management, organisation studies, strategy and human resource management. Knowledge governance is taken up with how the deployment of administrative...... apparatus influences knowledge processes, such as sharing, retaining and creating knowledge. It insists on clear behavioural foundations, adopts an economizing perspective and examines efficient alignment between knowledge transactions with diverse characteristics and governance structures and mechanisms...... with diverse capabilities of handling these transactions. Various open research issues that a knowledge governance approach may illuminate are sketched. Although knowledge governance draws clear inspiration from organizational economics and `rational' organization theory, it recognizes that knowledge...

  5. Stochastic population growth in spatially heterogeneous environments.

    Science.gov (United States)

    Evans, Steven N; Ralph, Peter L; Schreiber, Sebastian J; Sen, Arnab

    2013-02-01

    stochastic growth rate, we derive an explicit expression for the stochastic growth rate for populations living in two patches, determine which choices of the dispersal matrix D produce the maximal stochastic growth rate for a freely dispersing population, derive an analytic approximation of the stochastic growth rate for dispersal limited populations, and use group theoretic techniques to approximate the stochastic growth rate for populations living in multi-scale landscapes (e.g. insects on plants in meadows on islands). Our results provide fundamental insights into "ideal free" movement in the face of uncertainty, the persistence of coupled sink populations, the evolution of dispersal rates, and the single large or several small (SLOSS) debate in conservation biology. For example, our analysis implies that even in the absence of density-dependent feedbacks, ideal-free dispersers occupy multiple patches in spatially heterogeneous environments provided environmental fluctuations are sufficiently strong and sufficiently weakly correlated across space. In contrast, for diffusively dispersing populations living in similar environments, intermediate dispersal rates maximize their stochastic growth rate.

  6. Spatial Heterogeneity of Vegetation in China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The spatial heterogeneity and ecological characteristics of 74 vegetation types and the lack of vegetation type within the 9.6 million km2 of Chinese territory were studied using data from the China vegetation map. The analysis used 877 large quadrats 10 mm×10 mm (actual size 100 km×100 km), which covered about 8.77 million km2. Each large-quadrat was divided into four small 5 mm×5 mm quadrats (actual size 50 km×50 km). The frequency of occurrence of all vegetation types was recorded in each small quadrat.The survey using the Shiyomi method of vegetation analysis based on the beta-binomial distribution was adopted to describe the frequency of occurrence and spatial heterogeneity for each kind of vegetation. The weighted average heterogeneity of all the vegetation types in the landscape provides a measure of the landscape level heterogeneity which describes the spatial intricacy of the existing vegetation composition.The maximum spatial vegetation heterogeneity was 0.8620 in the frigid-temperate coniferous forest of Larix(V1), which dominates cold moist northeast China. The minimum spatial heterogeneity with a low occurrence was the Caragana tibetica in the gravel desert in the western Yellow River Hetao area. The minimum occurrence with a low spatial heterogeneity was the Monsoon rainforest on rock in Guangxi and Yunnan Provinces. The vegetation types on the Qing-Zang Plateau were found to be representative of Chinese vegetation because of the very high occurrence and spatial heterogeneity of these vegetation types. The weighted average of the heterogeneity was 0.677, while the vegetation diversity index was 3.29.

  7. Reliable knowledge discovery

    CERN Document Server

    Dai, Honghua; Smirnov, Evgueni

    2012-01-01

    Reliable Knowledge Discovery focuses on theory, methods, and techniques for RKDD, a new sub-field of KDD. It studies the theory and methods to assure the reliability and trustworthiness of discovered knowledge and to maintain the stability and consistency of knowledge discovery processes. RKDD has a broad spectrum of applications, especially in critical domains like medicine, finance, and military. Reliable Knowledge Discovery also presents methods and techniques for designing robust knowledge-discovery processes. Approaches to assessing the reliability of the discovered knowledge are introduc

  8. The tourism knowledge system

    DEFF Research Database (Denmark)

    Tribe, John; Liburd, Janne J.

    2016-01-01

    This conceptual study addresses the significant need for every mature field of knowledge to understand itself. It builds upon previous studies of the epistemology and ontology of tourism by critiquing, synthesising, discarding, re-ordering and adding material. Its contribution is an original...... reconceptualisation of the structure, systems, processes and outcomes that define the field of tourism. These are explained by the creation of a model and detailed analysis that examines knowledge space, the knowledge force-field, knowledge networks, four key domains in knowledge creation and their interrelationships....... Finally the model is used to examine some of the key challenges and consequences that the knowledge system reveals for tourism and its research....

  9. Organising knowledge taxonomies, knowledge and organisational effectiveness

    CERN Document Server

    Lambe, Patrick

    2007-01-01

    Taxonomies are often thought to play a niche role within content-oriented knowledge management projects. They are thought to be 'nice to have' but not essential. In this ground-breaking book, Patrick Lambe shows how they play an integral role in helping organizations coordinate and communicate effectively. Through a series of case studies, he demonstrates the range of ways in which taxonomies can help organizations to leverage and articulate their knowledge. A step-by-step guide in the book to running a taxonomy project is full of practical advice for knowledge managers and business owners ali

  10. Control DHT maintenance costs with session heterogeneity

    Institute of Scientific and Technical Information of China (English)

    ZOU Fu-tai; WU Zeng-de; ZHANG Liang; MA Fan-yuan

    2005-01-01

    The maintaining overheads of Distributed Hash Table (DHT) topology have recently received considerable attention.This paper presents a novel SHT (Session Heterogeneity Topology) model, in which DHT is reconstructed with session heterogeneity. SHT clusters nodes by means of session heterogeneity among nodes and selects the stable nodes as the participants of DHT. With an evolving process, this model gradually makes DHT stable and reliable. Therefore the high maintaining overheads for DHT are effectively controlled. Simulation with real traces of session distribution showed that the maintaining overheads are reduced dramatically and that the data availability is greatly improved.

  11. Adsorption of gases on heterogeneous surfaces

    CERN Document Server

    Rudzinski, W

    1991-01-01

    All real solid surfaces are heterogeneous to a greater or lesser extent and this book provides a broad yet detailed survey of the present state of gas adsorption. Coverage is comprehensive and extends from basic principles to computer simulation of adsorption. Underlying concepts are clarified and the strengths and weaknesses of the various methods described are discussed.Key Features* Adsorption isotherm equations for various types of heterogeneous solid surfaces* Methods of determining the nature of surface heterogeneity and porosity from experimental data* Studies of pha

  12. IMPROVING CO2 EFFICIENCY FOR RECOVERING OIL IN HETEROGENEOUS RESERVOIRS

    Energy Technology Data Exchange (ETDEWEB)

    Reid B. Grigg; Robert K. Svec

    2002-12-20

    This document is the First Annual Report for the U.S. Department of Energy under contract No., a three-year contract entitled: ''Improving CO{sub 2} Efficiency for Recovering Oil in Heterogeneous Reservoirs.'' The research improved our knowledge and understanding of CO{sub 2} flooding and includes work in the areas of injectivity and mobility control. The bulk of this work has been performed by the New Mexico Petroleum Recovery Research Center, a research division of New Mexico Institute of Mining and Technology. This report covers the reporting period of September 28, 2001 and September 27, 2002. Injectivity continues to be a concern to the industry. During this period we have contacted most of the CO{sub 2} operators in the Permian Basin and talked again about their problems in this area. This report has a summary of what we found. It is a given that carbonate mineral dissolution and deposition occur in a formation in geologic time and are expected to some degree in carbon dioxide (CO{sub 2}) floods. Water-alternating-gas (WAG) core flood experiments conducted on limestone and dolomite core plugs confirm that these processes can occur over relatively short time periods (hours to days) and in close proximity to each other. Results from laboratory CO{sub 2}-brine flow experiments performed in rock core were used to calibrate a reactive transport simulator. The calibrated model is being used to estimate in situ effects of a range of possible sequestration options in depleted oil/gas reservoirs. The code applied in this study is a combination of the well known TOUGH2 simulator, for coupled groundwater/brine and heat flow, with the chemistry code TRANS for chemically reactive transport. Variability in response among rock types suggests that CO{sub 2} injection will induce ranges of transient and spatially dependent changes in intrinsic rock permeability and porosity. Determining the effect of matrix changes on CO{sub 2} mobility is crucial in

  13. Optimization of a catchment-scale coupled surface-subsurface hydrological model using pilot points

    Science.gov (United States)

    Danapour, Mehrdis; Stisen, Simon; Lajer Højberg, Anker

    2016-04-01

    Transient coupled surface-subsurface models are usually complex and contain a large amount of spatio-temporal information. In the traditional calibration approach, model parameters are adjusted against only few spatially aggregated observations of discharge or individual point observations of groundwater head. However, this approach doesn't enable an assessment of spatially explicit predictive model capabilities at the intermediate scale relevant for many applications. The overall objectives of this project is to develop a new model calibration and evaluation framework by combining distributed model parameterization and regularization with new types of objective functions focusing on optimizing spatial patterns rather than individual points or catchment scale features. Inclusion of detailed observed spatial patterns of hydraulic head gradients or relevant information obtained from remote sensing data in the calibration process could allow for a better representation of spatial variability of hydraulic properties. Pilot Points as an alternative to classical parameterization approaches, introduce great flexibility when calibrating heterogeneous systems without neglecting expert knowledge (Doherty, 2003). A highly parameterized optimization of complex distributed hydrological models at catchment scale is challenging due to the computational burden that comes with it. In this study the physically-based coupled surface-subsurface model MIKE SHE is calibrated for the 8,500 km2 area of central Jylland (Denmark) that is characterized by heterogeneous geology and considerable groundwater flow across topographical catchment boundaries. The calibration of the distributed conductivity fields is carried out with a pilot point-based approach, implemented using the PEST parameter estimation tool. To reduce the high number of calibration parameters, PEST's advanced singular value decomposition combined with regularization was utilized and a reduction of the model's complexity was

  14. Computational Mechanics for Heterogeneous Materials

    Energy Technology Data Exchange (ETDEWEB)

    Lechman, Jeremy B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Baczewski, Andrew David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bond, Stephen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Erikson, William W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lehoucq, Richard B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Mondy, Lisa Ann [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Noble, David R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Pierce, Flint [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Roberts, Christine [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); van Swol, Frank B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Yarrington, Cole [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2013-11-01

    The subject of this work is the development of models for the numerical simulation of matter, momentum, and energy balance in heterogeneous materials. These are materials that consist of multiple phases or species or that are structured on some (perhaps many) scale(s). By computational mechanics we mean to refer generally to the standard type of modeling that is done at the level of macroscopic balance laws (mass, momentum, energy). We will refer to the flow or flux of these quantities in a generalized sense as transport. At issue here are the forms of the governing equations in these complex materials which are potentially strongly inhomogeneous below some correlation length scale and are yet homogeneous on larger length scales. The question then becomes one of how to model this behavior and what are the proper multi-scale equations to capture the transport mechanisms across scales. To address this we look to the area of generalized stochastic process that underlie the transport processes in homogeneous materials. The archetypal example being the relationship between a random walk or Brownian motion stochastic processes and the associated Fokker-Planck or diffusion equation. Here we are interested in how this classical setting changes when inhomogeneities or correlations in structure are introduced into the problem. Aspects of non-classical behavior need to be addressed, such as non-Fickian behavior of the mean-squared-displacement (MSD) and non-Gaussian behavior of the underlying probability distribution of jumps. We present an experimental technique and apparatus built to investigate some of these issues. We also discuss diffusive processes in inhomogeneous systems, and the role of the chemical potential in diffusion of hard spheres is considered. Also, the relevance to liquid metal solutions is considered. Finally we present an example of how inhomogeneities in material microstructure introduce fluctuations at the meso-scale for a thermal conduction problem

  15. Nickel/magnesium-lanthanum mixed oxide catalyst in the Kumada-coupling.

    Science.gov (United States)

    Kiss, Arpád; Hell, Zoltán; Bálint, Mária

    2010-01-21

    A new, heterogeneous, magnesium-lanthanum mixed oxide solid base-supported nickel(ii) catalyst was developed. The catalyst was used successfully in the Kumada coupling of aryl halides, especially aryl bromides. The optimal reaction conditions of the coupling were determined.

  16. Engineering Knowledge Management

    DEFF Research Database (Denmark)

    Wallace, Ken M.; Ahmed, Saeema; Bracewell, Rob

    2005-01-01

    The need to improve engineering knowledge management is driven by the current challenges facing manufacturing organisations in the emerging global economy and, in particular by the important role knowledge plays in the engineering design process. Industrial organisations are facing increasing...

  17. Does Knowledge Sharing Pay?

    DEFF Research Database (Denmark)

    Mahnke, Volker; Pedersen, Torben; Venzin, Markus

    This empirical paper explores knowledge outflow from MNC subsidiaries and its impact on the MNC performance. We develop and test hypotheses derived from literature on MNC knowledge flows integrated with the perspective of knowledge-creating, self-interested MNC subsidiaries. The hypotheses...... are developed using a simultaneous equation model applied to a unique dataset encompassing a German MNC, HeidelbergCement. Enablers and impediments of knowledge outflows are assessed in order to explain why subsidiaries share their knowledge with other MNC units. Implications are examined by studying the link...... between knowledge outflows and subsidiary performance. Our findings suggest that knowledge outflows increase a subsidiary's performance only up to a certain point and that too much knowledge sharing may be detrimental to the contributing subsidiary's performance....

  18. Stop the Knowledge Flow

    DEFF Research Database (Denmark)

    de Faria, Pedro; Sofka, Wolfgang; Shehu, Edlira

    Recent research has given special attention to international knowledge spillovers. Yet, multinational companies (MNCs) subsidiaries are generally treated as passive actors by most studies. We challenge this assumption by investigating the drivers of knowledge protection intensity of MNC...

  19. The Knowledge Explosion

    Science.gov (United States)

    Boulding, Kenneth E.

    1970-01-01

    Although human knowledge has expanded rapidly, especially during the scientific era, man is far from the limits of knowledge about the human learning process itself. Greatly increased effort in this area of inquiry is required for survival. (JH)

  20. Control of coupled oscillator networks with application to microgrid technologies.

    Science.gov (United States)

    Skardal, Per Sebastian; Arenas, Alex

    2015-08-01

    The control of complex systems and network-coupled dynamical systems is a topic of vital theoretical importance in mathematics and physics with a wide range of applications in engineering and various other sciences. Motivated by recent research into smart grid technologies, we study the control of synchronization and consider the important case of networks of coupled phase oscillators with nonlinear interactions-a paradigmatic example that has guided our understanding of self-organization for decades. We develop a method for control based on identifying and stabilizing problematic oscillators, resulting in a stable spectrum of eigenvalues, and in turn a linearly stable synchronized state. The amount of control, that is, number of oscillators, required to stabilize the network is primarily dictated by the coupling strength, dynamical heterogeneity, and mean degree of the network, and depends little on the structural heterogeneity of the network itself.