Analytical investigation of bidirectional ductile diaphragms in multi-span bridges

Science.gov (United States)

Wei, Xiaone; Bruneau, Michel

2018-04-01

In the AASHTO Guide Specifications for Seismic Bridge Design Provisions, ductile diaphragms are identified as Permissible Earthquake-Resisting Elements (EREs), designed to help resist seismic loads applied in the transverse direction of bridges. When adding longitudinal ductile diaphragms, a bidirectional ductile diaphragm system is created that can address seismic excitations acting along both the bridge's longitudinal and transverse axes. This paper investigates bidirectional ductile diaphragms with Buckling Restrained Braces (BRBs) in straight multi-span bridge with simply supported floating spans. The flexibility of the substructures in the transverse and longitudinal direction of the bridge is considered. Design procedures for the bidirectional ductile diaphragms are first proposed. An analytical model of the example bridge with bidirectional ductile diaphragms, designed based on the proposed methodology, is then built in SAP2000. Pushover and nonlinear time history analyses are performed on the bridge model, and corresponding results are presented. The effect of changing the longitudinal stiffness of the bidirectional ductile diaphragms in the end spans connecting to the abutment is also investigated, in order to better understand the impact on the bridge's dynamic performance.

ABOUT HYBRID BIDIRECTIONAL ASSOCIATIVE MEMORY NEURAL NETWORKS WITH DISCRETE DELAYS

Institute of Scientific and Technical Information of China (English)

无

2010-01-01

In this paper, hybrid bidirectional associative memory neural networks with discrete delays is considered. By ingeniously importing real parameters di > 0(i = 1,2,···,n) which can be adjusted, we establish some new sufficient conditions for the dynamical characteristics of hybrid bidirectional associative memory neural networks with discrete delays by the method of variation of parameters and some analysis techniques. Our results generalize and improve the related results in [10,11]. Our work is significant...

Concerning the dynamic instability of actin homolog ParM

International Nuclear Information System (INIS)

Popp, David; Yamamoto, Akihiro; Iwasa, Mitsusada; Narita, Akihiro; Maeda, Kayo; Maeda, Yuichiro

2007-01-01

Using in vitro TIRF- and electron-microscopy, we reinvestigated the dynamics of native ParM, a prokaryotic DNA segregation protein and actin homolog. In contrast to a previous study, which used a cysteine ParM mutant, we find that the polymerization process of wild type ATP-ParM filaments consists of a polymerization phase and a subsequent steady state phase, which is dynamically unstable, like that of microtubules. We find that the apparent bidirectional polymerization of ParM, is not due to the intrinsic nature of this filament, but results from ParM forming randomly oriented bundles in the presence of crowding agents. Our results imply, that in the bacterium, ParM filaments spontaneously form bipolar bundles. Due to their intrinsic dynamic instability, ParM bundles can efficiently 'search' the cytoplasmic lumen for DNA, bind it equally well at the bipolar ends and segregate it approximately symmetrically, by the insertion of ParM subunits at either end

The dynamic multisite interactions between two intrinsically disordered proteins

KAUST Repository

Wu, Shaowen

2017-05-11

Protein interactions involving intrinsically disordered proteins (IDPs) comprise a variety of binding modes, from the well characterized folding upon binding to dynamic fuzzy complex. To date, most studies concern the binding of an IDP to a structured protein, while the Interaction between two IDPs is poorly understood. In this study, we combined NMR, smFRET, and molecular dynamics (MD) simulation to characterize the interaction between two IDPs, the C-terminal domain (CTD) of protein 4.1G and the nuclear mitotic apparatus (NuMA) protein. It is revealed that CTD and NuMA form a fuzzy complex with remaining structural disorder. Multiple binding sites on both proteins were identified by MD and mutagenesis studies. Our study provides an atomic scenario in which two IDPs bearing multiple binding sites interact with each other in dynamic equilibrium. The combined approach employed here could be widely applicable for investigating IDPs and their dynamic interactions.

State-dependent intrinsic predictability of cortical network dynamics.

Directory of Open Access Journals (Sweden)

Leila Fakhraei

Full Text Available The information encoded in cortical circuit dynamics is fleeting, changing from moment to moment as new input arrives and ongoing intracortical interactions progress. A combination of deterministic and stochastic biophysical mechanisms governs how cortical dynamics at one moment evolve from cortical dynamics in recently preceding moments. Such temporal continuity of cortical dynamics is fundamental to many aspects of cortex function but is not well understood. Here we study temporal continuity by attempting to predict cortical population dynamics (multisite local field potential based on its own recent history in somatosensory cortex of anesthetized rats and in a computational network-level model. We found that the intrinsic predictability of cortical dynamics was dependent on multiple factors including cortical state, synaptic inhibition, and how far into the future the prediction extends. By pharmacologically tuning synaptic inhibition, we obtained a continuum of cortical states with asynchronous population activity at one extreme and stronger, spatially extended synchrony at the other extreme. Intermediate between these extremes we observed evidence for a special regime of population dynamics called criticality. Predictability of the near future (10-100 ms increased as the cortical state was tuned from asynchronous to synchronous. Predictability of the more distant future (>1 s was generally poor, but, surprisingly, was higher for asynchronous states compared to synchronous states. These experimental results were confirmed in a computational network model of spiking excitatory and inhibitory neurons. Our findings demonstrate that determinism and predictability of network dynamics depend on cortical state and the time-scale of the dynamics.

Intrinsic and Extrinsic Reading Motivation as Predictors of Reading Literacy: A Longitudinal Study

Science.gov (United States)

Becker, Michael; McElvany, Nele; Kortenbruck, Marthe

2010-01-01

The purpose in this study was to examine the longitudinal relationships of intrinsic and extrinsic motivation with reading literacy development. In particular, the authors (a) investigated reading amount as mediator between motivation and reading literacy and (b) probed for bidirectional relationships between reading motivation and reading…

The intrinsically disordered RNR inhibitor Sml1 is a dynamic dimer

DEFF Research Database (Denmark)

Danielsson, Jens; Liljedahl, Leena; Ba´ra´ny-Wallje, Elsa

2008-01-01

. Sml1 belongs to the class of intrinsically disordered proteins with a high degree of dynamics and very little stable structure. Earlier suggestions for a dimeric structure of Sml1 were confirmed, and from translation diffusion NMR measurements, a dimerization dissociation constant of 0.1 mM at 4...... natively disordered proteins....

High-frequency intrinsic dynamics of the electrocaloric effect from direct atomistic simulations

Science.gov (United States)

Lisenkov, S.; Ponomareva, I.

2018-05-01

We propose a computational methodology capable of harvesting isothermal heat and entropy change in molecular dynamics simulations. The methodology is applied to study high-frequency dynamics of the electrocaloric effect (ECE) in ferroelectric PbTiO3. ECE is associated with a reversible change in temperature under adiabatic application of electric field or with a reversible change in entropy under isothermal application of the electric field. Accurate assessment of electrocaloric performance requires the knowledge of three quantities: isothermal heat, isothermal entropy change, and adiabatic temperature change. Our methodology allows computations of all these quantities directly, that is, without restoring to the reversible thermodynamical models. Consequently, it captures both reversible and irreversible effects, which is critical for ECE simulations. The approach is well suited to address the dynamics of the ECE, which so far remains underexplored. We report the following basic features of the intrinsic dynamics of ECE: (i) the ECE is independent of the electric field frequency, rate of application, or field profile; (ii) the effect persists up to the frequencies associated with the onset of dielectric losses and deteriorates from there due to the creation of irreversible entropy; and (iii) in the vicinity of the phase transition and in the paraelectric phase the onset of irreversible dynamics occurs at lower frequency as compared to the ferroelectric phase. The latter is attributed to lower intrinsic soft-mode frequencies and and larger losses in the paraelectric phase.

Dominance dynamics of competition between intrinsic and extrinsic grouping cues.

Science.gov (United States)

Luna, Dolores; Villalba-García, Cristina; Montoro, Pedro R; Hinojosa, José A

2016-10-01

In the present study we examined the dominance dynamics of perceptual grouping cues. We used a paradigm in which participants selectively attended to perceptual groups based on several grouping cues in different blocks of trials. In each block, single and competing grouping cues were presented under different exposure durations (50, 150 or 350ms). Using this procedure, intrinsic vs. intrinsic cues (i.e. proximity and shape similarity) were compared in Experiment 1; extrinsic vs. extrinsic cues (i.e. common region and connectedness) in Experiment 2; and intrinsic vs. extrinsic cues (i.e. common region and shape similarity) in Experiment 3. The results showed that in Experiment 1, no dominance of any grouping cue was found: shape similarity and proximity grouping cues showed similar reaction times (RTs) and interference effects. In contrast, in Experiments 2 and 3, common region dominated processing: (i) RTs to common region were shorter than those to connectedness (Exp. 2) or shape similarity (Exp. 3); and (ii) when the grouping cues competed, common region interfered with connectedness (Exp. 2) and shape similarity (Exp. 3) more than vice versa. The results showed that the exposure duration of stimuli only affected the connectedness grouping cue. An important result of our experiments indicates that when two grouping cues compete, both the non-attended intrinsic cue in Experiment 1, and the non-dominant extrinsic cue in Experiments 2 and 3, are still perceived and they are not completely lost. Copyright © 2016 Elsevier B.V. All rights reserved.

Bimanual coordination and musical experience : The role of intrinsic dynamics and behavioral information

NARCIS (Netherlands)

Verheul, M.H.G.; Geuze, RH

Rhythmic interlimb coordination arises from the interaction of intrinsic dynamics and behavioral information, that is, intention, memory, or external information specifying the required coordination pattern. This study investigates the influence of the content of memorized behavioral information on

Deciphering the Dynamic Interaction Profile of an Intrinsically Disordered Protein by NMR Exchange Spectroscopy.

Science.gov (United States)

Delaforge, Elise; Kragelj, Jaka; Tengo, Laura; Palencia, Andrés; Milles, Sigrid; Bouvignies, Guillaume; Salvi, Nicola; Blackledge, Martin; Jensen, Malene Ringkjøbing

2018-01-24

Intrinsically disordered proteins (IDPs) display a large number of interaction modes including folding-upon-binding, binding without major structural transitions, or binding through highly dynamic, so-called fuzzy, complexes. The vast majority of experimental information about IDP binding modes have been inferred from crystal structures of proteins in complex with short peptides of IDPs. However, crystal structures provide a mainly static view of the complexes and do not give information about the conformational dynamics experienced by the IDP in the bound state. Knowledge of the dynamics of IDP complexes is of fundamental importance to understand how IDPs engage in highly specific interactions without concomitantly high binding affinity. Here, we combine rotating-frame R 1ρ , Carr-Purcell-Meiboom Gill relaxation dispersion as well as chemical exchange saturation transfer to decipher the dynamic interaction profile of an IDP in complex with its partner. We apply the approach to the dynamic signaling complex formed between the mitogen-activated protein kinase (MAPK) p38α and the intrinsically disordered regulatory domain of the MAPK kinase MKK4. Our study demonstrates that MKK4 employs a subtle combination of interaction modes in order to bind to p38α, leading to a complex displaying significantly different dynamics across the bound regions.

Theta rhythm-like bidirectional cycling dynamics of living neuronal networks in vitro.

Science.gov (United States)

Gladkov, Arseniy; Grinchuk, Oleg; Pigareva, Yana; Mukhina, Irina; Kazantsev, Victor; Pimashkin, Alexey

2018-01-01

The phenomena of synchronization, rhythmogenesis and coherence observed in brain networks are believed to be a dynamic substrate for cognitive functions such as learning and memory. However, researchers are still debating whether the rhythmic activity emerges from the network morphology that developed during neurogenesis or as a result of neuronal dynamics achieved under certain conditions. In the present study, we observed self-organized spiking activity that converged to long, complex and rhythmically repeated superbursts in neural networks formed by mature hippocampal cultures with a high cellular density. The superburst lasted for tens of seconds and consisted of hundreds of short (50-100 ms) small bursts with a high spiking rate of 139.0 ± 78.6 Hz that is associated with high-frequency oscillations in the hippocampus. In turn, the bursting frequency represents a theta rhythm (11.2 ± 1.5 Hz). The distribution of spikes within the bursts was non-random, representing a set of well-defined spatio-temporal base patterns or motifs. The long superburst was classified into two types. Each type was associated with a unique direction of spike propagation and, hence, was encoded by a binary sequence with random switching between the two "functional" states. The precisely structured bidirectional rhythmic activity that developed in self-organizing cultured networks was quite similar to the activity observed in the in vivo experiments.

Theta rhythm-like bidirectional cycling dynamics of living neuronal networks in vitro.

Directory of Open Access Journals (Sweden)

Arseniy Gladkov

Full Text Available The phenomena of synchronization, rhythmogenesis and coherence observed in brain networks are believed to be a dynamic substrate for cognitive functions such as learning and memory. However, researchers are still debating whether the rhythmic activity emerges from the network morphology that developed during neurogenesis or as a result of neuronal dynamics achieved under certain conditions. In the present study, we observed self-organized spiking activity that converged to long, complex and rhythmically repeated superbursts in neural networks formed by mature hippocampal cultures with a high cellular density. The superburst lasted for tens of seconds and consisted of hundreds of short (50-100 ms small bursts with a high spiking rate of 139.0 ± 78.6 Hz that is associated with high-frequency oscillations in the hippocampus. In turn, the bursting frequency represents a theta rhythm (11.2 ± 1.5 Hz. The distribution of spikes within the bursts was non-random, representing a set of well-defined spatio-temporal base patterns or motifs. The long superburst was classified into two types. Each type was associated with a unique direction of spike propagation and, hence, was encoded by a binary sequence with random switching between the two "functional" states. The precisely structured bidirectional rhythmic activity that developed in self-organizing cultured networks was quite similar to the activity observed in the in vivo experiments.

Bidirectional dynamics of materialism and loneliness : Not just a vicious cycle

NARCIS (Netherlands)

Pieters, R.

2013-01-01

This research is the first to test the hypothesis that consumers face a “material trap” in which materialism fosters social isolation which in turn reinforces materialism. It provides evidence that materialism and loneliness are engaged in bidirectional relationships over time. Importantly, it finds

Design of PI Controlled Non Isolated Bidirectional DC to DC Converter for Electric Vehicle Application

Science.gov (United States)

Geetha, A.; Subramani, C.; Thamizh Thentral, T. M.; Krithika, V.; Usha, S.

2018-04-01

Non isolated Bidirectional DC-DC Converter (NIBDDC) is a good interface between DC source and inverter Fed induction motor drive. This paper deals with comparison between open loop and PI controlled Bidirectional DC to DC Converter Inverter System (BDDCIS). The modelling and control of BDDC is becomes an important issue. Open loop BDDCIS and closed loop PI controlled BDDCIS are designed, modelled and simulated using Matlab- simulink and their results are presented. The investigations indicate superior performance of PI controlled BDDCIS. The proposed BDDCIS has advantages like bidirectional power transfer ability, reduced hardware count and improved dynamic response.

Bi-directional electrons in the near-Earth plasma sheet

Directory of Open Access Journals (Sweden)

K. Shiokawa

2003-07-01

Full Text Available We have studied the occurrence characteristics of bi-directional electron pitch angle anisotropy (enhanced flux in field-aligned directions, F^ /F|| > 1.5 at energies of 0.1–30 keV using plasma and magnetic field data from the AMPTE/IRM satellite in the near-Earth plasma sheet. The occurrence rate increases in the tailward direction from XGSM = - 9 RE to - 19 RE . The occurrence rate is also enhanced in the midnight sector, and furthermore, whenever the elevation angle of the magnetic field is large while the magnetic field intensity is small, B ~ 15 nT. From these facts, we conclude that the bi-directional electrons in the central plasma sheet are produced mainly in the vicinity of the neutral sheet and that the contribution from ionospheric electrons is minor. A high occurrence is also found after earthward high-speed ion flows, suggesting Fermi-type field-aligned electron acceleration in the neutral sheet. Occurrence characteristics of bi-directional electrons in the plasma sheet boundary layer are also discussed.Key words. Magnetospheric physics (magnetospheric configuration and dynamics; magnetotail; plasma sheet

A Statistical Theory of Bidirectionality

Science.gov (United States)

DeLoach, Richard; Ulbrich, Norbert

2013-01-01

Original concepts related to the quantification and assessment of bidirectionality in strain-gage balances were introduced by Ulbrich in 2012. These concepts are extended here in three ways: 1) the metric originally proposed by Ulbrich is normalized, 2) a categorical variable is introduced in the regression analysis to account for load polarity, and 3) the uncertainty in both normalized and non-normalized bidirectionality metrics is quantified. These extensions are applied to four representative balances to assess the bidirectionality characteristics of each. The paper is tutorial in nature, featuring reviews of certain elements of regression and formal inference. Principal findings are that bidirectionality appears to be a common characteristic of most balance outputs and that unless it is taken into account, it is likely to consume the entire error budget of a typical balance calibration experiment. Data volume and correlation among calibration loads are shown to have a significant impact on the precision with which bidirectionality metrics can be assessed.

Dynamic high-resolution ultrasound of intrinsic and extrinsic ligaments of the wrist: How to make it simple

International Nuclear Information System (INIS)

Gitto, Salvatore; Messina, Carmelo; Mauri, Giovanni; Aliprandi, Alberto; Sardanelli, Francesco; Sconfienza, Luca Maria

2017-01-01

Highlights: • US allows for rapid, cost-effective, and non-invasive assessment of wrist ligaments. • Knowledge of landmarks and dynamic manoeuvres is basic for a systematic examination. • A sequential approach is effective, timesaving and feasible in clinical practice. - Abstract: Wrist ligaments are crucial structures for the maintenance of carpal stability. They are classified into extrinsic ligaments, connecting the carpus with the forearm bones or distal radioulnar ligaments, and intrinsic ligaments, entirely situated within the carpus. Lesions of intrinsic and extrinsic ligaments of the wrist have been demonstrated to occur largely, mostly in patients with history of trauma and carpal instability, or rheumatoid arthritis. Ultrasound allows for rapid, cost-effective, non-invasive and dynamic evaluation of the wrist, and may represent a valuable diagnostic tool. Although promising results have been published, ultrasound of wrist ligaments is not performed in routine clinical practice, maybe due to its technical feasibility regarded as quite complex. This review article aims to enlighten readers about the normal sonographic appearance of intrinsic and extrinsic carpal ligaments, and describe a systematic approach for their sonographic assessment with detailed anatomic landmarks, dynamic manoeuvres and scanning technique.

Dynamic high-resolution ultrasound of intrinsic and extrinsic ligaments of the wrist: How to make it simple

Energy Technology Data Exchange (ETDEWEB)

Gitto, Salvatore, E-mail: sal.gitto@gmail.com [Scuola di Specializzazione in Radiodiagnostica, Università degli Studi di Milano, Via Festa del Perdono 7, 20122 Milano (Italy); Messina, Carmelo [Scuola di Specializzazione in Radiodiagnostica, Università degli Studi di Milano, Via Festa del Perdono 7, 20122 Milano (Italy); Mauri, Giovanni [Servizio di Radiologia, IRCCS Policlinico San Donato, Via Morandi 30, 20097 San Donato Milanese (Italy); Dipartimento di Radiologia Interventistica, Istituto Europeo di Oncologia, Via Ripamonti 435, 20141 Milano (Italy); Aliprandi, Alberto [Servizio di Radiologia, IRCCS Policlinico San Donato, Via Morandi 30, 20097 San Donato Milanese (Italy); Sardanelli, Francesco [Servizio di Radiologia, IRCCS Policlinico San Donato, Via Morandi 30, 20097 San Donato Milanese (Italy); Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, Via Pascal 36, 20133 Milano (Italy); Sconfienza, Luca Maria [Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, Via Pascal 36, 20133 Milano (Italy); Unità Operativa di Radiologia/Diagnostica per Immagini con Servizio di Radiologia Interventistica, IRCCS Istituto Ortopedico Galeazzi, Via Riccardo Galeazzi 4, 20161 Milano (Italy)

2017-02-15

Highlights: • US allows for rapid, cost-effective, and non-invasive assessment of wrist ligaments. • Knowledge of landmarks and dynamic manoeuvres is basic for a systematic examination. • A sequential approach is effective, timesaving and feasible in clinical practice. - Abstract: Wrist ligaments are crucial structures for the maintenance of carpal stability. They are classified into extrinsic ligaments, connecting the carpus with the forearm bones or distal radioulnar ligaments, and intrinsic ligaments, entirely situated within the carpus. Lesions of intrinsic and extrinsic ligaments of the wrist have been demonstrated to occur largely, mostly in patients with history of trauma and carpal instability, or rheumatoid arthritis. Ultrasound allows for rapid, cost-effective, non-invasive and dynamic evaluation of the wrist, and may represent a valuable diagnostic tool. Although promising results have been published, ultrasound of wrist ligaments is not performed in routine clinical practice, maybe due to its technical feasibility regarded as quite complex. This review article aims to enlighten readers about the normal sonographic appearance of intrinsic and extrinsic carpal ligaments, and describe a systematic approach for their sonographic assessment with detailed anatomic landmarks, dynamic manoeuvres and scanning technique.

Intramolecular three-colour single pair FRET of intrinsically disordered proteins with increased dynamic range.

Science.gov (United States)

Milles, Sigrid; Koehler, Christine; Gambin, Yann; Deniz, Ashok A; Lemke, Edward A

2012-10-01

Single molecule observation of fluorescence resonance energy transfer can be used to provide insight into the structure and dynamics of proteins. Using a straightforward triple-colour labelling strategy, we present a measurement and analysis scheme that can simultaneously study multiple regions within single intrinsically disordered proteins.

Dynamic high-resolution ultrasound of intrinsic and extrinsic ligaments of the wrist: How to make it simple.

Science.gov (United States)

Gitto, Salvatore; Messina, Carmelo; Mauri, Giovanni; Aliprandi, Alberto; Sardanelli, Francesco; Sconfienza, Luca Maria

2017-02-01

Wrist ligaments are crucial structures for the maintenance of carpal stability. They are classified into extrinsic ligaments, connecting the carpus with the forearm bones or distal radioulnar ligaments, and intrinsic ligaments, entirely situated within the carpus. Lesions of intrinsic and extrinsic ligaments of the wrist have been demonstrated to occur largely, mostly in patients with history of trauma and carpal instability, or rheumatoid arthritis. Ultrasound allows for rapid, cost-effective, non-invasive and dynamic evaluation of the wrist, and may represent a valuable diagnostic tool. Although promising results have been published, ultrasound of wrist ligaments is not performed in routine clinical practice, maybe due to its technical feasibility regarded as quite complex. This review article aims to enlighten readers about the normal sonographic appearance of intrinsic and extrinsic carpal ligaments, and describe a systematic approach for their sonographic assessment with detailed anatomic landmarks, dynamic manoeuvres and scanning technique. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

MicroRNA-Mediated Dynamic Bidirectional Shift between the Subclasses of Glioblastoma Stem-like Cells

Directory of Open Access Journals (Sweden)

Arun K. Rooj

2017-06-01

Full Text Available Large-scale transcriptomic profiling of glioblastoma (GBM into subtypes has provided remarkable insight into the pathobiology and heterogeneous nature of this disease. The mechanisms of speciation and inter-subtype transitions of these molecular subtypes require better characterization to facilitate the development of subtype-specific targeting strategies. The deregulation of microRNA expression among GBM subtypes and their subtype-specific targeting mechanisms are poorly understood. To reveal the underlying basis of microRNA-driven complex subpopulation dynamics within the heterogeneous intra-tumoral ecosystem, we characterized the expression of the subtype-enriched microRNA-128 (miR-128 in transcriptionally and phenotypically diverse subpopulations of patient-derived glioblastoma stem-like cells. Because microRNAs are capable of re-arranging the molecular landscape in a cell-type-specific manner, we argue that alterations in miR-128 levels are a potent mechanism of bidirectional transitions between GBM subpopulations, resulting in intermediate hybrid stages and emphasizing highly intricate intra-tumoral networking.

Personalized recommendation based on preferential bidirectional mass diffusion

Science.gov (United States)

Chen, Guilin; Gao, Tianrun; Zhu, Xuzhen; Tian, Hui; Yang, Zhao

2017-03-01

Recommendation system provides a promising way to alleviate the dilemma of information overload. In physical dynamics, mass diffusion has been used to design effective recommendation algorithms on bipartite network. However, most of the previous studies focus overwhelmingly on unidirectional mass diffusion from collected objects to uncollected objects, while overlooking the opposite direction, leading to the risk of similarity estimation deviation and performance degradation. In addition, they are biased towards recommending popular objects which will not necessarily promote the accuracy but make the recommendation lack diversity and novelty that indeed contribute to the vitality of the system. To overcome the aforementioned disadvantages, we propose a preferential bidirectional mass diffusion (PBMD) algorithm by penalizing the weight of popular objects in bidirectional diffusion. Experiments are evaluated on three benchmark datasets (Movielens, Netflix and Amazon) by 10-fold cross validation, and results indicate that PBMD remarkably outperforms the mainstream methods in accuracy, diversity and novelty.

Dynamic analysis of stochastic bidirectional associative memory neural networks with delays

International Nuclear Information System (INIS)

Zhao Hongyong; Ding Nan

2007-01-01

In this paper, stochastic bidirectional associative memory neural networks model with delays is considered. By constructing Lyapunov functionals, and using stochastic analysis method and inequality technique, we give some sufficient criteria ensuring almost sure exponential stability, pth exponential stability and mean value exponential stability. The obtained criteria can be used as theoretic guidance to stabilize neural networks in practical applications when stochastic noise is taken into consideration

Firing rate dynamics in recurrent spiking neural networks with intrinsic and network heterogeneity.

Science.gov (United States)

Ly, Cheng

2015-12-01

Heterogeneity of neural attributes has recently gained a lot of attention and is increasing recognized as a crucial feature in neural processing. Despite its importance, this physiological feature has traditionally been neglected in theoretical studies of cortical neural networks. Thus, there is still a lot unknown about the consequences of cellular and circuit heterogeneity in spiking neural networks. In particular, combining network or synaptic heterogeneity and intrinsic heterogeneity has yet to be considered systematically despite the fact that both are known to exist and likely have significant roles in neural network dynamics. In a canonical recurrent spiking neural network model, we study how these two forms of heterogeneity lead to different distributions of excitatory firing rates. To analytically characterize how these types of heterogeneities affect the network, we employ a dimension reduction method that relies on a combination of Monte Carlo simulations and probability density function equations. We find that the relationship between intrinsic and network heterogeneity has a strong effect on the overall level of heterogeneity of the firing rates. Specifically, this relationship can lead to amplification or attenuation of firing rate heterogeneity, and these effects depend on whether the recurrent network is firing asynchronously or rhythmically firing. These observations are captured with the aforementioned reduction method, and furthermore simpler analytic descriptions based on this dimension reduction method are developed. The final analytic descriptions provide compact and descriptive formulas for how the relationship between intrinsic and network heterogeneity determines the firing rate heterogeneity dynamics in various settings.

Dynamic stress of impeller blade of shaft extension tubular pump device based on bidirectional fluid-structure interaction

Energy Technology Data Exchange (ETDEWEB)

Kan, Kan; Liu, Huiwen; Yang, Chunxia [Hohai University, Nanjing (China); Zheng, Yuan [National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety, Nanjing (China); Fu, Shifeng; Zhang, Xin [Power China Huadong Engineering Corporation, Hangzhou (China)

2017-04-15

Current research on the stability of tubular pumps is mainly concerned with the transient hydrodynamic characteristics. However, the structural response under the influence of fluid-structure interaction hasn't been taken fully into consideration. The instability of the structure can cause vibration and cracks, which may threaten the safety of the unit. We used bidirectional fluid-structure interaction to comprehensively analyze the dynamic stress characteristics of the impeller blades of the shaft extension tubular pump device. Furthermore, dynamic stress of impeller blade of shaft extension tubular pump device was solved under different lift conditions of 0° blade angle. Based on Reynolds-average N-S equation and SST k-ω turbulence model, numerical simulation was carried out for three-dimensional unsteady incompressible turbulent flow field of the pump device whole flow passage. Meanwhile, the finite element method was used to calculate dynamic characteristics of the blade structure. The blade dynamic stress distribution was obtained on the basis of fourth strength theory. The research results indicate that the maximum blade dynamic stress appears at the joint between root of inlet side of the blade suction surface and the axis. Considering the influence of gravity, the fluctuation of the blade dynamic stress increases initially and decreases afterwards within a rotation period. In the meantime, the dynamic stress in the middle part of inlet edge presents larger relative fluctuation amplitude. Finally, a prediction method for dynamic stress distribution of tubular pump considering fluid-structure interaction and gravity effect was proposed. This method can be used in the design stage of tubular pump to predict dynamic stress distribution of the structure under different operating conditions, improve the reliability of pump impeller and analyze the impeller fatigue life.

Combining short- and long-range fluorescence reporters with simulations to explore the intramolecular dynamics of an intrinsically disordered protein

Science.gov (United States)

Zosel, Franziska; Haenni, Dominik; Soranno, Andrea; Nettels, Daniel; Schuler, Benjamin

2017-10-01

Intrinsically disordered proteins (IDPs) are increasingly recognized as a class of molecules that can exert essential biological functions even in the absence of a well-defined three-dimensional structure. Understanding the conformational distributions and dynamics of these highly flexible proteins is thus essential for explaining the molecular mechanisms underlying their function. Single-molecule fluorescence spectroscopy in combination with Förster resonance energy transfer (FRET) is a powerful tool for probing intramolecular distances and the rapid long-range distance dynamics in IDPs. To complement the information from FRET, we combine it with photoinduced electron transfer (PET) quenching to monitor local loop-closure kinetics at the same time and in the same molecule. Here we employed this combination to investigate the intrinsically disordered N-terminal domain of HIV-1 integrase. The results show that both long-range dynamics and loop closure kinetics on the sub-microsecond time scale can be obtained reliably from a single set of measurements by the analysis with a comprehensive model of the underlying photon statistics including both FRET and PET. A more detailed molecular interpretation of the results is enabled by direct comparison with a recent extensive atomistic molecular dynamics simulation of integrase. The simulations are in good agreement with experiment and can explain the deviation from simple models of chain dynamics by the formation of persistent local secondary structure. The results illustrate the power of a close combination of single-molecule spectroscopy and simulations for advancing our understanding of the dynamics and detailed mechanisms in unfolded and intrinsically disordered proteins.

Bidirectional optical rotation of cells

Directory of Open Access Journals (Sweden)

Jiyi Wu

2017-08-01

Full Text Available Precise and controlled rotation manipulation of cells is extremely important in biological applications and biomedical studies. Particularly, bidirectional rotation manipulation of a single or multiple cells is a challenge for cell tomography and analysis. In this paper, we report an optical method that is capable of bidirectional rotation manipulation of a single or multiple cells. By launching a laser beam at 980 nm into dual-beam tapered fibers, a single or multiple cells in solutions can be trapped and rotated bidirectionally under the action of optical forces. Moreover, the rotational behavior can be controlled by altering the relative distance between the two fibers and the input optical power. Experimental results were interpreted by numerical simulations.

Formation mechanism of a basin of attraction for passive dynamic walking induced by intrinsic hyperbolicity

Science.gov (United States)

Aoi, Shinya; Tsuchiya, Kazuo; Kokubu, Hiroshi

2016-01-01

Passive dynamic walking is a useful model for investigating the mechanical functions of the body that produce energy-efficient walking. The basin of attraction is very small and thin, and it has a fractal-like shape; this explains the difficulty in producing stable passive dynamic walking. The underlying mechanism that produces these geometric characteristics was not known. In this paper, we consider this from the viewpoint of dynamical systems theory, and we use the simplest walking model to clarify the mechanism that forms the basin of attraction for passive dynamic walking. We show that the intrinsic saddle-type hyperbolicity of the upright equilibrium point in the governing dynamics plays an important role in the geometrical characteristics of the basin of attraction; this contributes to our understanding of the stability mechanism of bipedal walking. PMID:27436971

Evaluation of complex gonioapparent samples using a bidirectional spectrometer.

Science.gov (United States)

Rogelj, Nina; Penttinen, Niko; Gunde, Marta Klanjšek

2015-08-24

Many applications use gonioapparent targets whose appearance depends on irradiation and viewing angles; the strongest effects are provided by light diffraction. These targets, optically variable devices (OVDs), are used in both security and authentication applications. This study introduces a bidirectional spectrometer, which enables to analyze samples with most complex angular and spectral properties. In our work, the spectrometer is evaluated with samples having very different types of reflection, concerning spectral and angular distributions. Furthermore, an OVD containing several different grating patches is evaluated. The device uses automatically adjusting exposure time to provide maximum signal dynamics and is capable of doing steps as small as 0.01°. However, even 2° steps for the detector movement showed that this device is more than capable of characterizing even the most complex reflecting surfaces. This study presents sRGB visualizations, discussion of bidirectional reflection, and accurate grating period calculations for all of the grating samples used.

Comparative analyses of bidirectional promoters in vertebrates

Directory of Open Access Journals (Sweden)

Taylor James

2008-05-01

Full Text Available Abstract Background Orthologous genes with deep phylogenetic histories are likely to retain similar regulatory features. In this report we utilize orthology assignments for pairs of genes co-regulated by bidirectional promoters to map the ancestral history of the promoter regions. Results Our mapping of bidirectional promoters from humans to fish shows that many such promoters emerged after the divergence of chickens and fish. Furthermore, annotations of promoters in deep phylogenies enable detection of missing data or assembly problems present in higher vertebrates. The functional importance of bidirectional promoters is indicated by selective pressure to maintain the arrangement of genes regulated by the promoter over long evolutionary time spans. Characteristics unique to bidirectional promoters are further elucidated using a technique for unsupervised classification, known as ESPERR. Conclusion Results of these analyses will aid in our understanding of the evolution of bidirectional promoters, including whether the regulation of two genes evolved as a consequence of their proximity or if function dictated their co-regulation.

The Independent and Shared Mechanisms of Intrinsic Brain Dynamics: Insights From Bistable Perception

Directory of Open Access Journals (Sweden)

Teng Cao

2018-04-01

Full Text Available In bistable perception, constant input leads to alternating perception. The dynamics of the changing perception reflects the intrinsic dynamic properties of the “unconscious inferential” process in the brain. Under the same condition, individuals differ in how fast they experience the perceptual alternation. In this study, testing many forms of bistable perception in a large number of observers, we investigated the key question of whether there is a general and common mechanism or multiple and independent mechanisms that control the dynamics of the inferential brain. Bistable phenomena tested include binocular rivalry, vase-face, Necker cube, moving plaid, motion induced blindness, biological motion, spinning dancer, rotating cylinder, Lissajous-figure, rolling wheel, and translating diamond. Switching dynamics for each bistable percept was measured in 100 observers. Results show that the switching rates of subsets of bistable percept are highly correlated. The clustering of dynamic properties of some bistable phenomena but not an overall general control of switching dynamics implies that the brain’s inferential processes are both shared and independent – faster in constructing 3D structure from motion does not mean faster in integrating components into an objects.

Ankle Joint Intrinsic Dynamics is More Complex than a Mass-Spring-Damper Model.

Science.gov (United States)

Sobhani Tehrani, Ehsan; Jalaleddini, Kian; Kearney, Robert E

2017-09-01

This paper describes a new small signal parametric model of ankle joint intrinsic mechanics in normal subjects. We found that intrinsic ankle mechanics is a third-order system and the second-order mass-spring-damper model, referred to as IBK, used by many researchers in the literature cannot adequately represent ankle dynamics at all frequencies in a number of important tasks. This was demonstrated using experimental data from five healthy subjects with no voluntary muscle contraction and at seven ankle positions covering the range of motion. We showed that the difference between the new third-order model and the conventional IBK model increased from dorsi to plantarflexed position. The new model was obtained using a multi-step identification procedure applied to experimental input/output data of the ankle joint. The procedure first identifies a non-parametric model of intrinsic joint stiffness where ankle position is the input and torque is the output. Then, in several steps, the model is converted into a continuous-time transfer function of ankle compliance, which is the inverse of stiffness. Finally, we showed that the third-order model is indeed structurally consistent with agonist-antagonist musculoskeletal structure of human ankle, which is not the case for the IBK model.

Data sets for modeling: A retrospective collection of Bidirectional Reflectance and Forest Ecosystems Dynamics Multisensor Aircraft Campaign data sets

Energy Technology Data Exchange (ETDEWEB)

Walthall, C.L.; Kim, M. (Univ. of Maryland, College Park, MD (United States). Dept. of Geography); Williams, D.L.; Meeson, B.W.; Agbu, P.A.; Newcomer, J.A.; Levine, E.R.

1993-12-01

The Biospheric Sciences Branch, within the Laboratory for Terrestrial Physics at NASA's Goddard Space Flight Center, has assembled two data sets for free dissemination to the remote sensing research community. One data set, referred to as the Retrospective Bidirectional Reflectance Distribution Function (BRDF) Data Collection, is a collection of bidirectional reflectance and supporting biophysical measurements of surfaces ranging in diversity from bare soil to heavily forested canopies. The other data collection, resulting from measurements made in association with the Forest Ecosystems Dynamic Multisensor Aircraft Campaign (FED MAC), contains data that are relevant to ecosystem process models, particularly those which have been modified to incorporate remotely sensed data. Both of these collections are being made available to the science community at large in order to facilitate model development, validation, and usage. These data collections are subsets which have been compiled and consolidated from individual researcher or from several large data set collections including: the First International Satellite Land Surface Climatology Project (ISLSCP) Field Experiment (FIFE); FED MAC; the Superior National Forest Project (SNF); the Geologic Remote Sensing Field Experiment (GRSFE); and Agricultural Inventories through Space Applications of Remote Sensing (AgriStars). The complete, stand-along FED MAC Data Collection contains atmospheric, vegetation, and soils data acquired during field measurement campaigns conducted at international Papers' Northern Experimental Forest located approximately 40 km north of Bangor, Maine. Reflectance measurements at the canopy, branch, and needle level are available, along with the detailed canopy architectural measurements.

[Differences of bi-directional regulative effects between acu-moxibustion and Chinese materia medica interventions].

Science.gov (United States)

Cao, Xin; Yu, Zhi; Xu, Bin

2012-10-01

Bi-directional regulation is referred to a balancing effect of both acu-moxibustion and Chinese materia medica interventions when the human body is experiencing a hyperactivity or hypoactivity due to abnormal intrinsic or external factors. In the present paper, the authors analyze their identical and different characteristics from: 1) definition; 2) characters of regulative effects of acu-moxibustion therapy: A) differentiation of meridian and zangfu-organs being the basis of treatment, B) four factors (acupoint-location, body's functional state, acupoint-formula and needle-manipulation techniques) dependant, C) entirety regulation, and D) centrotaxis modulation; 3) characters of Chinese materia medica intervention: including a) correspondence between the drug property and the syndrome being the basis of the regulative effect, b) multi-factors [components (antagonist and agonist), combination, dosages and processing quality of Chinese materia medica, and functional state of the human body] dependant, c) entirety regulation, and d) both centrotaxis and deviation adjustment. In one word, the bi-directional regulation effect is one of the basic characteristics of both acu-moxibustion and Chinese materia medica in clinical practice, but their basis and modes for inducing effects are different.

Numerical Simulation Bidirectional Chaotic Synchronization of Spiegel-Moore Circuit and Its Application for Secure Communication

Science.gov (United States)

Sanjaya, W. S. M.; Anggraeni, D.; Denya, R.; Ismail, N.

2017-03-01

Spiegel-Moore is a dynamical chaotic system which shows irregular variability in the luminosity of stars. In this paper present the performed the design and numerical simulation of the synchronization Spiegel-Moore circuit and applied to security system for communication. The initial study in this paper is to analyze the eigenvalue structures, various attractors, Bifurcation diagram, and Lyapunov exponent analysis. We have studied the dynamic behavior of the system in the case of the bidirectional coupling via a linear resistor. Both experimental and simulation results have shown that chaotic synchronization is possible. Finally, the effectiveness of the bidirectional coupling scheme between two identical Spiegel-Moore circuits in a secure communication system is presented in details. Integration of theoretical electronic circuit, the numerical simulation by using MATLAB®, as well as the implementation of circuit simulations by using Multisim® has been performed in this study.

Bidirectional waveguide coupling with plasmonic Fano nanoantennas

Energy Technology Data Exchange (ETDEWEB)

Guo, Rui; Decker, Manuel, E-mail: manuel.decker@anu.edu.au; Staude, Isabelle; Neshev, Dragomir N.; Kivshar, Yuri S. [Nonlinear Physics Centre and Centre for Ultrahigh Bandwidth Devices for Optical Systems (CUDOS), Research School of Physics and Engineering, The Australian National University, Canberra ACT 0200 (Australia)

2014-08-04

We introduce the concept of a bidirectional, compact single-element Fano nanoantenna that allows for directional coupling of light in opposite directions of a high-index dielectric waveguide for two different operation wavelengths. We utilize a Fano resonance to tailor the radiation phases of a gold nanodisk and a nanoslit that is inscribed into the nanodisk to realize bidirectional scattering. We show that this Fano nanoantenna operates as a bidirectional waveguide coupler at telecommunication wavelengths and, thus, is ideally suitable for integrated wavelength-selective light demultiplexing.

Evaluation of a bi-directional aluminum honeycomb impact limiter design

International Nuclear Information System (INIS)

Doman, M.J.

1995-01-01

A 120 Ton shipping cask is being developed for the on-site shipment of dry spent fuel at the Idaho National Engineering Laboratory. Impact limiters were incorporated in the cask design to limit the inertial load of the package and its contents during the hypothetical 9-meter (30-foot) drop accident required by 10CFR71. The design process included: (1) a series of static and dynamic tests to determine the crush characteristics of the bi-directional aluminum honeycomb impact limiter material, (2) the development of an analytical model to predict the cask deceleration force as a function of impact limiter crush, and (3) a series of quarter scale model drop tests to qualify the analytical model. The scale model testing, performed at Sandia National Laboratory in Albuquerque, New Mexico, revealed several design aspects which should be considered in developing bi-directional aluminum honeycomb impact limiters and several other design aspects which should be considered for impact limiter designs in general

Nonlinear stochastic exclusion financial dynamics modeling and time-dependent intrinsic detrended cross-correlation

Science.gov (United States)

Zhang, Wei; Wang, Jun

2017-09-01

In attempt to reproduce price dynamics of financial markets, a stochastic agent-based financial price model is proposed and investigated by stochastic exclusion process. The exclusion process, one of interacting particle systems, is usually thought of as modeling particle motion (with the conserved number of particles) in a continuous time Markov process. In this work, the process is utilized to imitate the trading interactions among the investing agents, in order to explain some stylized facts found in financial time series dynamics. To better understand the correlation behaviors of the proposed model, a new time-dependent intrinsic detrended cross-correlation (TDI-DCC) is introduced and performed, also, the autocorrelation analyses are applied in the empirical research. Furthermore, to verify the rationality of the financial price model, the actual return series are also considered to be comparatively studied with the simulation ones. The comparison results of return behaviors reveal that this financial price dynamics model can reproduce some correlation features of actual stock markets.

Generalized model of a bidirectional DC-DC converter

Science.gov (United States)

Hinov, Nikolay; Arnaudov, Dimitar; Penev, Dimitar

2017-12-01

The following paperwork presents models of bidirectional converters. A classic bidirectional converter and a new bidirectional circuit based on a ZCS resonant converter are investigated and compared. The developed models of these converters allow comparison between their characteristics showing their advantages and disadvantages. The models allow precise models of energy storage elements to be implemented as well, which is useful for examination of energy storage systems.

Bidirectional Modulation of Intrinsic Excitability in Rat Prelimbic Cortex Neuronal Ensembles and Non-Ensembles after Operant Learning.

Science.gov (United States)

Whitaker, Leslie R; Warren, Brandon L; Venniro, Marco; Harte, Tyler C; McPherson, Kylie B; Beidel, Jennifer; Bossert, Jennifer M; Shaham, Yavin; Bonci, Antonello; Hope, Bruce T

2017-09-06

Learned associations between environmental stimuli and rewards drive goal-directed learning and motivated behavior. These memories are thought to be encoded by alterations within specific patterns of sparsely distributed neurons called neuronal ensembles that are activated selectively by reward-predictive stimuli. Here, we use the Fos promoter to identify strongly activated neuronal ensembles in rat prelimbic cortex (PLC) and assess altered intrinsic excitability after 10 d of operant food self-administration training (1 h/d). First, we used the Daun02 inactivation procedure in male FosLacZ-transgenic rats to ablate selectively Fos-expressing PLC neurons that were active during operant food self-administration. Selective ablation of these neurons decreased food seeking. We then used male FosGFP-transgenic rats to assess selective alterations of intrinsic excitability in Fos-expressing neuronal ensembles (FosGFP + ) that were activated during food self-administration and compared these with alterations in less activated non-ensemble neurons (FosGFP - ). Using whole-cell recordings of layer V pyramidal neurons in an ex vivo brain slice preparation, we found that operant self-administration increased excitability of FosGFP + neurons and decreased excitability of FosGFP - neurons. Increased excitability of FosGFP + neurons was driven by increased steady-state input resistance. Decreased excitability of FosGFP - neurons was driven by increased contribution of small-conductance calcium-activated potassium (SK) channels. Injections of the specific SK channel antagonist apamin into PLC increased Fos expression but had no effect on food seeking. Overall, operant learning increased intrinsic excitability of PLC Fos-expressing neuronal ensembles that play a role in food seeking but decreased intrinsic excitability of Fos - non-ensembles. SIGNIFICANCE STATEMENT Prefrontal cortex activity plays a critical role in operant learning, but the underlying cellular mechanisms are

Intrinsic and Extrinsic Neuromodulation of Olfactory Processing.

Science.gov (United States)

Lizbinski, Kristyn M; Dacks, Andrew M

2017-01-01

Neuromodulation is a ubiquitous feature of neural systems, allowing flexible, context specific control over network dynamics. Neuromodulation was first described in invertebrate motor systems and early work established a basic dichotomy for neuromodulation as having either an intrinsic origin (i.e., neurons that participate in network coding) or an extrinsic origin (i.e., neurons from independent networks). In this conceptual dichotomy, intrinsic sources of neuromodulation provide a "memory" by adjusting network dynamics based upon previous and ongoing activation of the network itself, while extrinsic neuromodulators provide the context of ongoing activity of other neural networks. Although this dichotomy has been thoroughly considered in motor systems, it has received far less attention in sensory systems. In this review, we discuss intrinsic and extrinsic modulation in the context of olfactory processing in invertebrate and vertebrate model systems. We begin by discussing presynaptic modulation of olfactory sensory neurons by local interneurons (LNs) as a mechanism for gain control based on ongoing network activation. We then discuss the cell-class specific effects of serotonergic centrifugal neurons on olfactory processing. Finally, we briefly discuss the integration of intrinsic and extrinsic neuromodulation (metamodulation) as an effective mechanism for exerting global control over olfactory network dynamics. The heterogeneous nature of neuromodulation is a recurring theme throughout this review as the effects of both intrinsic and extrinsic modulation are generally non-uniform.

Method of Obtaining High Resolution Intrinsic Wire Boom Damping Parameters for Multi-Body Dynamics Simulations

Science.gov (United States)

Yew, Alvin G.; Chai, Dean J.; Olney, David J.

2010-01-01

The goal of NASA's Magnetospheric MultiScale (MMS) mission is to understand magnetic reconnection with sensor measurements from four spinning satellites flown in a tight tetrahedron formation. Four of the six electric field sensors on each satellite are located at the end of 60- meter wire booms to increase measurement sensitivity in the spin plane and to minimize motion coupling from perturbations on the main body. A propulsion burn however, might induce boom oscillations that could impact science measurements if oscillations do not damp to values on the order of 0.1 degree in a timely fashion. Large damping time constants could also adversely affect flight dynamics and attitude control performance. In this paper, we will discuss the implementation of a high resolution method for calculating the boom's intrinsic damping, which was used in multi-body dynamics simulations. In summary, experimental data was obtained with a scaled-down boom, which was suspended as a pendulum in vacuum. Optical techniques were designed to accurately measure the natural decay of angular position and subsequently, data processing algorithms resulted in excellent spatial and temporal resolutions. This method was repeated in a parametric study for various lengths, root tensions and vacuum levels. For all data sets, regression models for damping were applied, including: nonlinear viscous, frequency-independent hysteretic, coulomb and some combination of them. Our data analysis and dynamics models have shown that the intrinsic damping for the baseline boom is insufficient, thereby forcing project management to explore mitigation strategies.

Bidirectional optical scattering facility

Data.gov (United States)

Federal Laboratory Consortium — Goniometric optical scatter instrument (GOSI)The bidirectional reflectance distribution function (BRDF) quantifies the angular distribution of light scattered from a...

Slow-oscillatory transcranial direct current stimulation can induce bidirectional shifts in motor cortical excitability in awake humans

DEFF Research Database (Denmark)

Groppa, S; Bergmann, T O; Siems, C

2010-01-01

Constant transcranial direct stimulation (c-tDCS) of the primary motor hand area (M1(HAND)) can induce bidirectional shifts in motor cortical excitability depending on the polarity of tDCS. Recently, anodal slow oscillation stimulation at a frequency of 0.75 Hz has been shown to augment intrinsic...... slow oscillations during sleep and theta oscillations during wakefulness. To embed this new type of stimulation into the existing tDCS literature, we aimed to characterize the after effects of slowly oscillating stimulation (so-tDCS) on M1(HAND) excitability and to compare them to those of c-tDCS. Here...

A bidirectional Optimality Theoretic analysis of multiple negative ...

African Journals Online (AJOL)

IT

6 All examples in this paper are colloquial Afrikaans unless otherwise ...... and bidirectional optimisation over these form-meaning pairs results in the selection of one or ..... Imperfective and perfective habituals in Polish: A bi-directional.

Advances in Support of the CMAQ Bidirectional Science Option for the Estimation of Ammonia Flux from Agricultural cropland

Science.gov (United States)

Proposed Session: Emissions Inventories, Models and processes: Last year a new CMAQ bidirectional option for the estimation of ammonia flux (emission and deposition) was released. This option essentially replaces NEI crop ammonia emissions with emissions calculated dynamically...

Kinematical tests for the intrinsic shapes of galaxies

International Nuclear Information System (INIS)

Capaccioli, M.; Fasano, G.

1984-01-01

Determining the intrinsic shape of elliptical galaxies has been an illusive enterprise, but one fundamental to the understanding of their internal dynamics and formation. Here the problem is approached dynamically; noting that the velocity dispersion is largest when sighted down the longest axis, the correlations are derived of velocity dispersion with observed eccentricity expected, after the known trend of velocity dispersion with luminosity is removed. Using a compilation of published data, the relation between luminosity and velocity dispersion is determined more accurately. The residuals are examined as a function of axis ratio in order to construct a test for the intrinsic shape of galaxies. The effects of projection are modelled and possible intrinsic variations are examined. (author)

MECHANICAL AND THERMO–MECHANICAL PROPERTIES OF BI-DIRECTIONAL AND SHORT CARBON FIBER REINFORCED EPOXY COMPOSITES

Directory of Open Access Journals (Sweden)

G. AGARWAL

2014-10-01

Full Text Available This paper based on bidirectional and short carbon fiber reinforced epoxy composites reports the effect of fiber loading on physical, mechanical and thermo-mechanical properties respectively. The five different fiber loading, i.e., 10wt. %, 20wt. %, 30wt. %, 40wt. % and 50wt. % were taken for evaluating the above said properties. The physical and mechanical properties, i.e., hardness, tensile strength, flexural strength, inter-laminar shear strength and impact strength are determined to represent the behaviour of composite structures with that of fiber loading. Thermo-mechanical properties of the material are measured with the help of Dynamic Mechanical Analyser to measure the damping capacity of the material that is used to reduce the vibrations. The effect of storage modulus, loss modulus and tan delta with temperature are determined. Finally, Cole–Cole analysis is performed on both bidirectional and short carbon fiber reinforced epoxy composites to distinguish the material properties of either homogeneous or heterogeneous materials. The results show that with the increase in fiber loading the mechanical properties of bidirectional carbon fiber reinforced epoxy composites increases as compared to short carbon fiber reinforced epoxy composites except in case of hardness, short carbon fiber reinforced composites shows better results. Similarly, as far as Loss modulus, storage modulus is concerned bidirectional carbon fiber shows better damping behaviour than short carbon fiber reinforced composites.

Image Captioning with Deep Bidirectional LSTMs

OpenAIRE

Wang, Cheng; Yang, Haojin; Bartz, Christian; Meinel, Christoph

2016-01-01

This work presents an end-to-end trainable deep bidirectional LSTM (Long-Short Term Memory) model for image captioning. Our model builds on a deep convolutional neural network (CNN) and two separate LSTM networks. It is capable of learning long term visual-language interactions by making use of history and future context information at high level semantic space. Two novel deep bidirectional variant models, in which we increase the depth of nonlinearity transition in different way, are propose...

The robustness in dynamics of out of equilibrium bidirectional transport systems with constrained entrances

Science.gov (United States)

Sharma, Natasha; Verma, Atul Kumar; Gupta, Arvind Kumar

2018-05-01

Macroscopic and microscopic long-distance bidirectional transfer depends on connections between entrances and exits of various transport mediums. Persuaded by the associations, we introduce a small system module of Totally Asymmetric Simple Exclusion Process including oppositely directed species of particles moving on two parallel channels with constrained entrances. The dynamical rules which characterize the system obey symmetry between the two species and are identical for both the channels. The model displays a rich steady-state behavior, including symmetry breaking phenomenon. The phase diagram is analyzed theoretically within the mean-field approximation and substantiated with Monte Carlo simulations. Relevant mean-field calculations are also presented. We further compared the phase segregation with those observed in previous works, and it is examined that the structure of phase separation in proposed model is distinguished from earlier ones. Interestingly, for phases with broken symmetry, symmetry with respect to channels has been observed as the distinct particles behave differently while the similar type of particles exhibits the same conduct in the system. For symmetric phases, significant properties including currents and densities in the channels are identical for both types of particles. The effect of symmetry breaking occurrence on the Monte Carlo simulation results has also been examined based on particle density histograms. Finally, phase properties of the system having strong size dependency have been explored based on simulations findings.

The role of intrinsic disorder and dynamics in the assembly and function of the type II secretion system.

Science.gov (United States)

Gu, Shuang; Shevchik, Vladimir E; Shaw, Rosie; Pickersgill, Richard W; Garnett, James A

2017-10-01

Many Gram-negative commensal and pathogenic bacteria use a type II secretion system (T2SS) to transport proteins out of the cell. These exported proteins or substrates play a major role in toxin delivery, maintaining biofilms, replication in the host and subversion of host immune responses to infection. We review the current structural and functional work on this system and argue that intrinsically disordered regions and protein dynamics are central for assembly, exo-protein recognition, and secretion competence of the T2SS. The central role of intrinsic disorder-order transitions in these processes may be a particular feature of type II secretion. Copyright © 2017 Elsevier B.V. All rights reserved.

Intrinsic motivation, curiosity, and learning: Theory and applications in educational technologies.

Science.gov (United States)

Oudeyer, P-Y; Gottlieb, J; Lopes, M

2016-01-01

This chapter studies the bidirectional causal interactions between curiosity and learning and discusses how understanding these interactions can be leveraged in educational technology applications. First, we review recent results showing how state curiosity, and more generally the experience of novelty and surprise, can enhance learning and memory retention. Then, we discuss how psychology and neuroscience have conceptualized curiosity and intrinsic motivation, studying how the brain can be intrinsically rewarded by novelty, complexity, or other measures of information. We explain how the framework of computational reinforcement learning can be used to model such mechanisms of curiosity. Then, we discuss the learning progress (LP) hypothesis, which posits a positive feedback loop between curiosity and learning. We outline experiments with robots that show how LP-driven attention and exploration can self-organize a developmental learning curriculum scaffolding efficient acquisition of multiple skills/tasks. Finally, we discuss recent work exploiting these conceptual and computational models in educational technologies, showing in particular how intelligent tutoring systems can be designed to foster curiosity and learning. © 2016 Elsevier B.V. All rights reserved.

Bidirectional ventricular tachycardia of unknown etiology

International Nuclear Information System (INIS)

Ali, M.; Khan, J.A.; Masood, T.; Shamsi, F.; Dero, M.H.; Khan, S.

2013-01-01

A 45 years old male presented to the emergency department with palpitations, headache and apprehension. His electrocardiogram revealed bidirectional ventricular tachycardia. He remained vitally stable and responded to intravenous beta-blocker. Initially digitalis toxicity was suspected but history was negative for digitalis intake. The cause remained unidentified in patient despite detailed investigations. During a short follow-up (of 6 months) he remained asymptomatic and no cause was further identified during this period. Some other unseen causes of bidirectional ventricular tachycardia need to be explored. (author)

Global asymptotic stability analysis of bidirectional associative memory neural networks with distributed delays and impulse

International Nuclear Information System (INIS)

Huang Zaitang; Luo Xiaoshu; Yang Qigui

2007-01-01

Many systems existing in physics, chemistry, biology, engineering and information science can be characterized by impulsive dynamics caused by abrupt jumps at certain instants during the process. These complex dynamical behaviors can be model by impulsive differential system or impulsive neural networks. This paper formulates and studies a new model of impulsive bidirectional associative memory (BAM) networks with finite distributed delays. Several fundamental issues, such as global asymptotic stability and existence and uniqueness of such BAM neural networks with impulse and distributed delays, are established

Symmetry evaluation for an interferometric fiber optic gyro coil utilizing a bidirectional distributed polarization measurement system.

Science.gov (United States)

Peng, Feng; Li, Chuang; Yang, Jun; Hou, Chengcheng; Zhang, Haoliang; Yu, Zhangjun; Yuan, Yonggui; Li, Hanyang; Yuan, Libo

2017-07-10

We propose a dual-channel measurement system for evaluating the optical path symmetry of an interferometric fiber optic gyro (IFOG) coil. Utilizing a bidirectional distributed polarization measurement system, the forward and backward transmission performances of an IFOG coil are characterized simultaneously by just a one-time measurement. The simple but practical configuration is composed of a bidirectional Mach-Zehnder interferometer and multichannel transmission devices connected to the IFOG coil under test. The static and dynamic temperature results of the IFOG coil reveal that its polarization-related symmetric properties can be effectively obtained with high accuracy. The optical path symmetry investigation is highly beneficial in monitoring and improving the winding technology of an IFOG coil and reducing the nonreciprocal effect of an IFOG.

Intrinsic periodic and aperiodic stochastic resonance in an electrochemical cell

Science.gov (United States)

Tiwari, Ishant; Phogat, Richa; Parmananda, P.; Ocampo-Espindola, J. L.; Rivera, M.

2016-08-01

In this paper we show the interaction of a composite of a periodic or aperiodic signal and intrinsic electrochemical noise with the nonlinear dynamics of an electrochemical cell configured to study the corrosion of iron in an acidic media. The anodic voltage setpoint (V0) in the cell is chosen such that the anodic current (I ) exhibits excitable fixed point behavior in the absence of noise. The subthreshold periodic (aperiodic) signal consists of a train of rectangular pulses with a fixed amplitude and width, separated by regular (irregular) time intervals. The irregular time intervals chosen are of deterministic and stochastic origins. The amplitude of the intrinsic internal noise, regulated by the concentration of chloride ions, is then monotonically increased, and the provoked dynamics are analyzed. The signal to noise ratio and the cross-correlation coefficient versus the chloride ions' concentration curves have a unimodal shape indicating the emergence of an intrinsic periodic or aperiodic stochastic resonance. The abscissa for the maxima of these unimodal curves correspond to the optimum value of intrinsic noise where maximum regularity of the invoked dynamics is observed. In the particular case of the intrinsic periodic stochastic resonance, the scanning electron microscope images for the electrode metal surfaces are shown for certain values of chloride ions' concentrations. These images, qualitatively, corroborate the emergence of order as a result of the interaction between the nonlinear dynamics and the composite signal.

Self-oscillating Galvanic Isolated Bidirectional Very High Frequency DC-DC Converter

DEFF Research Database (Denmark)

Pedersen, Jeppe Arnsdorf; Madsen, Mickey Pierre; Knott, Arnold

2015-01-01

This paper describes a galvanic isolated bidirectional Very High Frequency (VHF = 30 MHz - 300MHz) ClassE converter. The reason for increasing the switching frequency is to minimize the passive components in the converter. To make the converter topology bidirectional the rectifier has to be synch......This paper describes a galvanic isolated bidirectional Very High Frequency (VHF = 30 MHz - 300MHz) ClassE converter. The reason for increasing the switching frequency is to minimize the passive components in the converter. To make the converter topology bidirectional the rectifier has...

Bidirectional reachability-based modules

CSIR Research Space (South Africa)

Nortje, R

2011-07-01

Full Text Available The authors introduce an algorithm for MinA extraction in EL based on bidirectional reachability. They obtain a significant reduction in the size of modules extracted at almost no additional cost to that of extracting standard reachability...

Symmetric reconfigurable capacity assignment in a bidirectional DWDM access network.

Science.gov (United States)

Ortega, Beatriz; Mora, José; Puerto, Gustavo; Capmany, José

2007-12-10

This paper presents a novel architecture for DWDM bidirectional access networks providing symmetric dynamic capacity allocation for both downlink and uplink signals. A foldback arrayed waveguide grating incorporating an optical switch enables the experimental demonstration of flexible assignment of multiservice capacity. Different analog and digital services, such as CATV, 10 GHz-tone, 155Mb/s PRBS and UMTS signals have been transmitted in order to successfully test the system performance under different scenarios of total capacity distribution from the Central Station to different Base Stations with two reconfigurable extra channels for each down and upstream direction.

Socio-Hydrology: Conceptual and Methodological Challenges in the Bidirectional Coupling of Human and Water Systems

Science.gov (United States)

Scott, C. A.

2014-12-01

This presentation reviews conceptual advances in the emerging field of socio-hydrology that focuses on coupled human and water systems. An important current challenge is how to better couple the bidirectional influences between human and water systems, which lead to emergent dynamics. The interactions among (1) the structure and dynamics of systems with (2) human values and norms lead to (3) outcomes, which in turn influence subsequent interactions. Human influences on hydrological systems are relatively well understood, chiefly resulting from developments in the field of water resources. The ecosystem-service concept of cultural value has expanded understanding of decision-making beyond economic rationality criteria. Hydrological impacts on social processes are less well developed conceptually, but this is changing with growing attention to vulnerability, adaptation, and resilience, particularly in the face of climate change. Methodological limitations, especially in characterizing the range of human responses to hydrological events and drivers, still pose challenges to modeling bidirectional human-water influences. Evidence from multiple case studies, synthesized in more broadly generic syndromes, helps surmount these methodological limitations and offers the potential to improve characterization and quantification of socio-hydrological systems.

Piezoelectric power converter with bi-directional power transfer

DEFF Research Database (Denmark)

2014-01-01

The present invention relates to a bi-directional piezoelectric power converter com¬ prising a piezoelectric transformer. The piezoelectric transformer comprises an input electrode electrically coupled to a primary section of the piezoelectric transformer and an output electrode electrically...... coupled to an output section of the piezoelectric transformer to provide a transformer output signal. A bi-directional switching circuit is coupled between the output electrode and a DC or AC output voltage of the power converter. Forward and reverse current conducting periods of the bi......, a reverse current is conducted through the bi-directional switching circuit from the DC or AC output voltage to the output electrode to discharge the DC or AC output voltage and return power to the primary section of the piezoelectric transformer....

Integrable hydrodynamics of Calogero-Sutherland model: bidirectional Benjamin-Ono equation

International Nuclear Information System (INIS)

Abanov, Alexander G; Bettelheim, Eldad; Wiegmann, Paul

2009-01-01

We develop a hydrodynamic description of the classical Calogero-Sutherland liquid: a Calogero-Sutherland model with an infinite number of particles and a non-vanishing density of particles. The hydrodynamic equations, being written for the density and velocity fields of the liquid, are shown to be a bidirectional analog of the Benjamin-Ono equation. The latter is known to describe internal waves of deep stratified fluids. We show that the bidirectional Benjamin-Ono equation appears as a real reduction of the modified KP hierarchy. We derive the chiral nonlinear equation which appears as a chiral reduction of the bidirectional equation. The conventional Benjamin-Ono equation is a degeneration of the chiral nonlinear equation at large density. We construct multi-phase solutions of the bidirectional Benjamin-Ono equations and of the chiral nonlinear equations

Bidirectional Associations Between Newlyweds' Marital Satisfaction and Marital Problems over Time.

Science.gov (United States)

Lavner, Justin A; Karney, Benjamin R; Williamson, Hannah C; Bradbury, Thomas N

2017-12-01

Prevailing views of marital functioning generally adopt the view that marital problems predict decreases in marital satisfaction, but alternative theoretical perspectives raise the possibility that lowered satisfaction can also predict increases in problems. The current study sought to integrate and compare these perspectives by examining the bidirectional cross-lagged associations between newlyweds' reports of their marital satisfaction and marital problems over the first 4 years of marriage. Using annual assessments from 483 heterosexual newlywed couples, we find evidence for problem-to-satisfaction linkages as well as satisfaction-to-problem linkages. Satisfaction was a stronger predictor of marital problems early in marriage but not as time passed; by Year 4 only problem-to-satisfaction linkages remained significant. These findings are consistent with the idea that couples with more problems go on to report lower levels of satisfaction and couples with lower levels of satisfaction go on to report more marital problems. This dynamic interplay between global judgments about relationship satisfaction and ongoing specific relationship difficulties highlights the value of examining bidirectional effects to better understand marital functioning over time. © 2016 Family Process Institute.

Parametric amplification and bidirectional invisibility in PT -symmetric time-Floquet systems

Science.gov (United States)

Koutserimpas, Theodoros T.; Alù, Andrea; Fleury, Romain

2018-01-01

Parity-time (PT )-symmetric wave devices, which exploit balanced interactions between material gain and loss, exhibit extraordinary properties, including lasing and flux-conserving scattering processes. In a seemingly different research field, periodically driven systems, also known as time-Floquet systems, have been widely studied as a relevant platform for reconfigurable active wave control and manipulation. In this article, we explore the connection between PT -symmetry and parametric time-Floquet systems. Instead of relying on material gain, we use parametric amplification by considering a time-periodic modulation of the refractive index at a frequency equal to twice the incident signal frequency. We show that the scattering from a simple parametric slab, whose dynamics follows the Mathieu equation, can be described by a PT -symmetric scattering matrix, whose PT -breaking threshold corresponds to the Mathieu instability threshold. By combining different parametric slabs modulated out of phase, we create PT -symmetric time-Floquet systems that feature exceptional scattering properties, such as coherent perfect absorption (CPA)-laser operation and bidirectional invisibility. These bidirectional properties, rare for regular PT -symmetric systems, are related to a compensation of parametric amplification due to multiple scattering between two parametric systems modulated with a phase difference.

Improving protein disorder prediction by deep bidirectional long short-term memory recurrent neural networks.

Science.gov (United States)

Hanson, Jack; Yang, Yuedong; Paliwal, Kuldip; Zhou, Yaoqi

2017-03-01

Capturing long-range interactions between structural but not sequence neighbors of proteins is a long-standing challenging problem in bioinformatics. Recently, long short-term memory (LSTM) networks have significantly improved the accuracy of speech and image classification problems by remembering useful past information in long sequential events. Here, we have implemented deep bidirectional LSTM recurrent neural networks in the problem of protein intrinsic disorder prediction. The new method, named SPOT-Disorder, has steadily improved over a similar method using a traditional, window-based neural network (SPINE-D) in all datasets tested without separate training on short and long disordered regions. Independent tests on four other datasets including the datasets from critical assessment of structure prediction (CASP) techniques and >10 000 annotated proteins from MobiDB, confirmed SPOT-Disorder as one of the best methods in disorder prediction. Moreover, initial studies indicate that the method is more accurate in predicting functional sites in disordered regions. These results highlight the usefulness combining LSTM with deep bidirectional recurrent neural networks in capturing non-local, long-range interactions for bioinformatics applications. SPOT-disorder is available as a web server and as a standalone program at: http://sparks-lab.org/server/SPOT-disorder/index.php . j.hanson@griffith.edu.au or yuedong.yang@griffith.edu.au or yaoqi.zhou@griffith.edu.au. Supplementary data is available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

A TTC upgrade proposal using bidirectional 10G-PON FTTH technology

Science.gov (United States)

Kolotouros, D. M.; Baron, S.; Soos, C.; Vasey, F.

2015-04-01

A new generation FPGA-based Timing-Trigger and Control (TTC) system based on emerging Passive Optical Network (PON) technology is being proposed to replace the existing off-detector TTC system used by the LHC experiments. High split ratio, dynamic software partitioning, low and deterministic latency, as well as low jitter are required. Exploiting the latest available technologies allows delivering higher capacity together with bidirectionality, a feature absent from the legacy TTC system. This article focuses on the features and capabilities of the latest TTC-PON prototype based on 10G-PON FTTH components along with some metrics characterizing its performance.

A TTC upgrade proposal using bidirectional 10G-PON FTTH technology

International Nuclear Information System (INIS)

Kolotouros, D.M.; Baron, S.; Soos, C.; Vasey, F.

2015-01-01

A new generation FPGA-based Timing-Trigger and Control (TTC) system based on emerging Passive Optical Network (PON) technology is being proposed to replace the existing off-detector TTC system used by the LHC experiments. High split ratio, dynamic software partitioning, low and deterministic latency, as well as low jitter are required. Exploiting the latest available technologies allows delivering higher capacity together with bidirectionality, a feature absent from the legacy TTC system. This article focuses on the features and capabilities of the latest TTC-PON prototype based on 10G-PON FTTH components along with some metrics characterizing its performance

The internal flow pattern analysis of a tidal power turbine operating on bidirectional generation-pumping

International Nuclear Information System (INIS)

Luo, Y Y; Xiao, Y X; Wang, Z W

2013-01-01

Using tidal energy can reduce environment pollution, save conventional energy and improve energy structure, hence it presents great advantage and is developing potential. Influenced by flood tide and low tide, a fully functional tidal power station needs to experience six operating modes, including bidirectional generation, pumping and sluice; the internal unsteady flow pattern and dynamic characters are very complicated. Based on a bidirectional tidal generator unit, three-dimensional unsteady flows in the flow path were calculated for four typical operating conditions with the pressure pulsation characteristics analyzed. According to the numerical results, the internal flow characteristics in the flow path were discussed. The influence of gravity to the hydraulic performance and flow characteristics were analysed. The results provide a theoretical analysis method of the hydraulic optimization design of the same type unit as well as a direction for stable operation and optimal scheduling of existing tidal power unit

The intrinsic stochasticity of near-integrable Hamiltonian systems

Energy Technology Data Exchange (ETDEWEB)

Krlin, L [Ceskoslovenska Akademie Ved, Prague (Czechoslovakia). Ustav Fyziky Plazmatu

1989-09-01

Under certain conditions, the dynamics of near-integrable Hamiltonian systems appears to be stochastic. This stochasticity (intrinsic stochasticity, or deterministic chaos) is closely related to the Kolmogorov-Arnold-Moser (KAM) theorem of the stability of near-integrable multiperiodic Hamiltonian systems. The effect of the intrinsic stochasticity attracts still growing attention both in theory and in various applications in contemporary physics. The paper discusses the relation of the intrinsic stochasticity to the modern ergodic theory and to the KAM theorem, and describes some numerical experiments on related astrophysical and high-temperature plasma problems. Some open questions are mentioned in conclusion. (author).

Beyond the evoked/intrinsic neural process dichotomy

Directory of Open Access Journals (Sweden)

Taylor Bolt

2018-03-01

Full Text Available Contemporary functional neuroimaging research has increasingly focused on characterization of intrinsic or “spontaneous” brain activity. Analysis of intrinsic activity is often contrasted with analysis of task-evoked activity that has traditionally been the focus of cognitive neuroscience. But does this evoked/intrinsic dichotomy adequately characterize human brain function? Based on empirical data demonstrating a close functional interdependence between intrinsic and task-evoked activity, we argue that the dichotomy between intrinsic and task-evoked activity as unobserved contributions to brain activity is artificial. We present an alternative picture of brain function in which the brain’s spatiotemporal dynamics do not consist of separable intrinsic and task-evoked components, but reflect the enaction of a system of mutual constraints to move the brain into and out of task-appropriate functional configurations. According to this alternative picture, cognitive neuroscientists are tasked with describing both the temporal trajectory of brain activity patterns across time, and the modulation of this trajectory by task states, without separating this process into intrinsic and task-evoked components. We argue that this alternative picture of brain function is best captured in a novel explanatory framework called enabling constraint. Overall, these insights call for a reconceptualization of functional brain activity, and should drive future methodological and empirical efforts.

The Topologies Research of a Soft Switching Bidirectional DC/DC Converter

DEFF Research Database (Denmark)

Zhang, Qi; Zhang, Yongping; Sun, Xiangdong

2017-01-01

A soft-switching solution implemented to the traditional bidirectional DC/DC converter is developed. The soft-switching cell, which composed of three auxiliary switches, one resonant capacitor and one resonant inductor, is equipped in the traditional bidirectional DC/DC converter to realize circuit...... circle. And the proposed topology of bidirectional soft-switching dc-dc converter(TASBC) performs ideal soft switching at boost operations. The characteristics of the proposed converter has been verified by MATLAB simulations and experimental results....

Impurity flux collection at the plasma edge of the tokamak MT-1

International Nuclear Information System (INIS)

Hildebrandt, D.; Bakos, J.S.; Petravich, G.

1989-09-01

Fluxes of intrinsic and injected impurities and background plasma ions were collected using a bidirectional probe at the plasma edge of the tokamak MT-1. The directional and radial dependences of injected impurities and plasma ions were very similar indicating a strong coupling of the impurity transport to the dynamics of the background plasma. The measured intrinsic concentration of about 10 -4 for Mo at the plasma edge is derived. (author) 17 refs.; 5 figs

Conceptualizing a Dynamic Fall Risk Model Including Intrinsic Risks and Exposures.

Science.gov (United States)

Klenk, Jochen; Becker, Clemens; Palumbo, Pierpaolo; Schwickert, Lars; Rapp, Kilan; Helbostad, Jorunn L; Todd, Chris; Lord, Stephen R; Kerse, Ngaire

2017-11-01

Falls are a major cause of injury and disability in older people, leading to serious health and social consequences including fractures, poor quality of life, loss of independence, and institutionalization. To design and provide adequate prevention measures, accurate understanding and identification of person's individual fall risk is important. However, to date, the performance of fall risk models is weak compared with models estimating, for example, cardiovascular risk. This deficiency may result from 2 factors. First, current models consider risk factors to be stable for each person and not change over time, an assumption that does not reflect real-life experience. Second, current models do not consider the interplay of individual exposure including type of activity (eg, walking, undertaking transfers) and environmental risks (eg, lighting, floor conditions) in which activity is performed. Therefore, we posit a dynamic fall risk model consisting of intrinsic risk factors that vary over time and exposure (activity in context). eHealth sensor technology (eg, smartphones) begins to enable the continuous measurement of both the above factors. We illustrate our model with examples of real-world falls from the FARSEEING database. This dynamic framework for fall risk adds important aspects that may improve understanding of fall mechanisms, fall risk models, and the development of fall prevention interventions. Copyright © 2017 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

Fluxons in long and annular intrinsic Josephson junction stacks

CERN Document Server

Clauss, T; Moessle, M; Müller, A; Weber, A; Kölle, D; Kleiner, R

2002-01-01

A promising approach towards a THz oscillator based on intrinsic Josephson junctions in high-temperature superconductors is based on the collective motion of Josephson fluxons, which are predicted to form various configurations ranging from a triangular to a quadratic lattice. Not only for this reason, but certainly also for the sake of basic physics, several experimental and theoretical investigations have been done on the subject of collective fluxon dynamics in stacked intrinsic Josephson junctions. In this paper we will present some experimental results on the fluxon dynamics of long intrinsic Josephson junction stacks made of Bi sub 2 Sr sub 2 CaCu sub 2 O sub 8. The stacks were formed either in an open or in an annular geometry, and clear resonant fluxon modes were observed. Experiments discussed include measurements of current-voltage characteristics in external magnetic fields and in external microwave fields.

A bidirectional shape memory alloy folding actuator

International Nuclear Information System (INIS)

Paik, Jamie K; Wood, Robert J

2012-01-01

This paper presents a low-profile bidirectional folding actuator based on annealed shape memory alloy sheets applicable for meso- and microscale systems. Despite the advantages of shape memory alloys—high strain, silent operation, and mechanical simplicity—their application is often limited to unidirectional operation. We present a bidirectional folding actuator that produces two opposing 180° motions. A laser-patterned nickel alloy (Inconel 600) heater localizes actuation to the folding sections. The actuator has a thin ( < 1 mm) profile, making it appropriate for use in robotic origami. Various design parameters and fabrication variants are described and experimentally explored in the actuator prototype. (paper)

A new low threshold bi-directional wind vane and its potential impact on unplanned atmospheric release prediction

International Nuclear Information System (INIS)

Parker, M.J.

1996-01-01

At the Savannah River Site, the Environmental Transport Group (ETG) maintains and develops a comprehensive meteorological monitoring program which employs bi-directional wind vanes (bivanes) for the measurement of horizontal and vertical wind direction and turbulence. Wind data collected near and below instrument starting thresholds under stable nighttime conditions with these bivanes can result in artificially large standard deviations of horizontal wind direction (σA). In one hypothetical case, downwind concentrations could be underestimated by a factor of 40 by using artificially high σA data in a Gaussian dispersion model. In an effort to improve low wind speed measurements of wind direction, a Cooperative Research and Development Agreement (CRADA) between Met One Instruments and the Westinghouse Savannah River Company (WSRC) has been created to improve the dynamic performance of the Met One Model 1585 Bi-Directional Wind Vane

The Contribution of Red Blood Cell Dynamics to Intrinsic Viscosity and Functional ATP Release

Science.gov (United States)

Forsyth, Alison; Abkarian, Manouk; Wan, Jiandi; Stone, Howard

2010-11-01

In shear flow, red blood cells (RBCs) exhibit a variety of behaviors such as rouleaux formation, tumbling, swinging, and tank-treading. The physiological consequences of these dynamic behaviors are not understood. In vivo, ATP is known to signal vasodilation; however, to our knowledge, no one has deciphered the relevance of RBC microrheology to the functional release of ATP. Previously, we correlated RBC deformation and ATP release in microfluidic constrictions (Wan et al., 2008). In this work, a cone-plate rheometer is used to shear a low hematocrit solution of RBCs at varying viscosity ratios (λ) between the inner cytoplasmic hemoglobin and the outer medium, to determine the intrinsic viscosity of the suspension. Further, using a luciferin-luciferase enzymatic reaction, we report the relative ATP release at varying shear rates. Results indicate that for λ = 1.6, 3.8 and 11.1, ATP release is constant up to 500 s-1, which suggests that the tumbling-tanktreading transition does not alter ATP release in pure shear. For lower viscosity ratios, λ = 1.6 and 3.8, at 500 s-1 a change in slope occurs in the intrinsic viscosity data and is marked by an increase in ATP release. Based on microfluidic observations, this simultaneous change in viscosity and ATP release occurs within the tank-treading regime.

Incremental Learning of Skill Collections based on Intrinsic Motivation

Directory of Open Access Journals (Sweden)

Jan Hendrik Metzen

2013-07-01

Full Text Available Life-long learning of reusable, versatile skills is a key prerequisite forembodied agents that act in a complex, dynamic environment and are faced withdifferent tasks over their lifetime. We address the question of how an agentcan learn useful skills efficiently during a developmental period,i.e., when no task is imposed on him and no external reward signal is provided.Learning of skills in a developmental period needs to be incremental andself-motivated. We propose a new incremental, task-independent skill discoveryapproach that is suited for continuous domains. Furthermore, the agent learnsspecific skills based on intrinsic motivation mechanisms thatdetermine on which skills learning is focused at a given point in time. Weevaluate the approach in a reinforcement learning setup in two continuousdomains with complex dynamics. We show that an intrinsically motivated, skilllearning agent outperforms an agent which learns task solutions from scratch.Furthermore, we compare different intrinsic motivation mechanisms and howefficiently they make use of the agent's developmental period.

Bidirectional uncompressed HD video distribution over fiber employing VCSELs

DEFF Research Database (Denmark)

Estaran Tolosa, Jose Manuel; Vegas Olmos, Juan José; Rodes, G. A.

2012-01-01

We report on a bidirectional system in which VCSELs are simultaneously modulated with two uncompressed HD video signals. The results show a large power budget and a negligible penalty over 10 km long transmission links.......We report on a bidirectional system in which VCSELs are simultaneously modulated with two uncompressed HD video signals. The results show a large power budget and a negligible penalty over 10 km long transmission links....

Ethnic Stigma, Academic Anxiety, and Intrinsic Motivation in Middle Childhood

Science.gov (United States)

Gillen-O’Neel, Cari; Ruble, Diane N.; Fuligni, Andrew J.

2011-01-01

Previous research addressing the dynamics of stigma and academics has focused on African-American adolescents and adults. The present study examined stigma awareness, academic anxiety, and intrinsic motivation among 451 young (ages 6–11) and diverse (African-American, Chinese, Dominican, Russian, and European-American) students. Results indicated that ethnic-minority children reported higher stigma awareness than European-American children. For all children, stigma awareness was associated with higher academic anxiety and lower intrinsic motivation. Despite these associations, ethnic-minority children reported higher levels of intrinsic motivation than their European-American peers. A significant portion of the higher intrinsic motivation among Dominican students was associated with their higher levels of school belonging, suggesting that supportive school environments may be important sources of intrinsic motivation among some ethnic-minority children. PMID:21883152

Activity-Dependent Bidirectional Regulation of GAD Expression in a Homeostatic Fashion Is Mediated by BDNF-Dependent and Independent Pathways

Science.gov (United States)

Hanno-Iijima, Yoko; Tanaka, Masami; Iijima, Takatoshi

2015-01-01

Homeostatic synaptic plasticity, or synaptic scaling, is a mechanism that tunes neuronal transmission to compensate for prolonged, excessive changes in neuronal activity. Both excitatory and inhibitory neurons undergo homeostatic changes based on synaptic transmission strength, which could effectively contribute to a fine-tuning of circuit activity. However, gene regulation that underlies homeostatic synaptic plasticity in GABAergic (GABA, gamma aminobutyric) neurons is still poorly understood. The present study demonstrated activity-dependent dynamic scaling in which NMDA-R (N-methyl-D-aspartic acid receptor) activity regulated the expression of GABA synthetic enzymes: glutamic acid decarboxylase 65 and 67 (GAD65 and GAD67). Results revealed that activity-regulated BDNF (brain-derived neurotrophic factor) release is necessary, but not sufficient, for activity-dependent up-scaling of these GAD isoforms. Bidirectional forms of activity-dependent GAD expression require both BDNF-dependent and BDNF-independent pathways, both triggered by NMDA-R activity. Additional results indicated that these two GAD genes differ in their responsiveness to chronic changes in neuronal activity, which could be partially caused by differential dependence on BDNF. In parallel to activity-dependent bidirectional scaling in GAD expression, the present study further observed that a chronic change in neuronal activity leads to an alteration in neurotransmitter release from GABAergic neurons in a homeostatic, bidirectional fashion. Therefore, the differential expression of GAD65 and 67 during prolonged changes in neuronal activity may be implicated in some aspects of bidirectional homeostatic plasticity within mature GABAergic presynapses. PMID:26241953

Global evaluation of ammonia bidirectional exchange and livestock diurnal variation schemes

Science.gov (United States)

Bidirectional air–surface exchange of ammonia (NH3) has been neglected in many air quality models. In this study, we implement the bidirectional exchange of NH3 in the GEOS-Chem global chemical transport model. We also introduce an updated diurnal variability scheme for NH3...

Bidirectional semantic associations between social power and weight.

Science.gov (United States)

He, Xiaoling; Chen, Jun; Li, Jianan

2018-02-01

Two experiments were conducted to examine bidirectional semantic associations between power and weight using a priming paradigm. Bidirectionality in the relationship between power and weight was demonstrated, utilising tasks that were identical except that the orders in which the stimuli were presented were reversed. In Experiment 1, an empty scale leaning either leftward or rightward was used as a priming stimulus, and a scale that appeared in equilibrium with a pair of power words was used as a target stimulus. In Experiment 2, a scale with a pair of words that appeared in equilibrium was used as a priming stimulus, and an empty scale leaning either leftward or rightward was used as a target stimulus. We identified interaction effects between power and weight in both experiments. Associations between power and weight provide evidence for both conceptual metaphor views and evolutionary theory. The bidirectionality of metaphorical effects is in line with the strong version of metaphoric structuring. Both language and experiential correlations play important roles in the development of the mapping between power and weight. © 2016 International Union of Psychological Science.

Performance and cavitation characteristics of bi-directional hydrofoils

Science.gov (United States)

Nedyalkov, Ivaylo; Wosnik, Martin

2013-11-01

Tidal turbines extract energy from flows which reverse direction. One way to address this bi-directionality in horizontal axis turbines that avoid the use of complex and maintenance-intensive yaw or blade pitch mechanisms, is to design bi-directional blades which perform (equally) well in either flow direction. A large number of proposed hydrofoil designs were investigated using numerical simulations. Selected candidate foils were also tested (at various speeds and angles of attack) in the High-Speed Cavitation Tunnel (HICaT) at the University of New Hampshire. Lift and drag were measured using a force balance, and cavitation inception and desinence were recorded. Experimental and numerical results were compared, and the foils were compared to each other and to reference foils. Bi-directional hydrofoils may provide a feasible solution to the problem of reversing flow direction, when their performance and cavitation characteristics are comparable to those for unidirectional foils, and the penalty in decreased energy production is outweighed by the cost reduction due to lower complexity and respectively lower installation and maintenance costs.

A psychophysically validated metric for bidirectional texture data reduction

Czech Academy of Sciences Publication Activity Database

Filip, Jiří; Chantler, M.J.; Green, P.R.; Haindl, Michal

2008-01-01

Roč. 27, č. 5 (2008), s. 138:1-138:11 ISSN 0730-0301 R&D Projects: GA AV ČR 1ET400750407; GA ČR GA102/08/0593 Institutional research plan: CEZ:AV0Z10750506 Keywords : Bidirectional Texture Functions * texture compression Subject RIV: BD - Theory of Information Impact factor: 3.383, year: 2008 http://library.utia.cas.cz/separaty/2008/RO/haindl-a psychophysically validated metric for bidirectional texture data reduction.pdf

Framewise phoneme classification with bidirectional LSTM and other neural network architectures.

Science.gov (United States)

Graves, Alex; Schmidhuber, Jürgen

2005-01-01

In this paper, we present bidirectional Long Short Term Memory (LSTM) networks, and a modified, full gradient version of the LSTM learning algorithm. We evaluate Bidirectional LSTM (BLSTM) and several other network architectures on the benchmark task of framewise phoneme classification, using the TIMIT database. Our main findings are that bidirectional networks outperform unidirectional ones, and Long Short Term Memory (LSTM) is much faster and also more accurate than both standard Recurrent Neural Nets (RNNs) and time-windowed Multilayer Perceptrons (MLPs). Our results support the view that contextual information is crucial to speech processing, and suggest that BLSTM is an effective architecture with which to exploit it.

Constrained bidirectional propagation and stroke segmentation

Energy Technology Data Exchange (ETDEWEB)

Mori, S; Gillespie, W; Suen, C Y

1983-03-01

A new method for decomposing a complex figure into its constituent strokes is described. This method, based on constrained bidirectional propagation, is suitable for parallel processing. Examples of its application to the segmentation of Chinese characters are presented. 9 references.

An Integrative Dynamical Systems Perspective on Emotions

NARCIS (Netherlands)

Treur, J.

2013-01-01

Within cognitive, affective and social neuroscience more and more mechanisms are found that suggest how emotions relate in a bidirectional manner to many other mental processes and behaviour. Based on this, in this paper a neurologically inspired dynamical systems approach on the dynamics and

Incremental learning of skill collections based on intrinsic motivation

Science.gov (United States)

Metzen, Jan H.; Kirchner, Frank

2013-01-01

Life-long learning of reusable, versatile skills is a key prerequisite for embodied agents that act in a complex, dynamic environment and are faced with different tasks over their lifetime. We address the question of how an agent can learn useful skills efficiently during a developmental period, i.e., when no task is imposed on him and no external reward signal is provided. Learning of skills in a developmental period needs to be incremental and self-motivated. We propose a new incremental, task-independent skill discovery approach that is suited for continuous domains. Furthermore, the agent learns specific skills based on intrinsic motivation mechanisms that determine on which skills learning is focused at a given point in time. We evaluate the approach in a reinforcement learning setup in two continuous domains with complex dynamics. We show that an intrinsically motivated, skill learning agent outperforms an agent which learns task solutions from scratch. Furthermore, we compare different intrinsic motivation mechanisms and how efficiently they make use of the agent's developmental period. PMID:23898265

Outpatient blood pressure monitoring using bi-directional text messaging.

Science.gov (United States)

Anthony, Chris A; Polgreen, Linnea A; Chounramany, James; Foster, Eric D; Goerdt, Christopher J; Miller, Michelle L; Suneja, Manish; Segre, Alberto M; Carter, Barry L; Polgreen, Philip M

2015-05-01

To diagnose hypertension, multiple blood pressure (BP) measurements are recommended. We randomized patients into three groups: EMR-only (patients recorded BP measurements in an electronic medical record [EMR] web portal), EMR + reminders (patients were sent text message reminders to record their BP measurements in the EMR), and bi-directional text messaging (patients were sent a text message asking them to respond with their current BP). Subjects were asked to complete 14 measurements. Automated messages were sent to each patient in the bi-directional text messaging and EMR + reminder groups twice daily. Among 121 patients, those in the bi-directional text messaging group reported the full 14 measurements more often than both the EMR-only group (P text messaging is an effective way to gather patient BP data. Text-message-based reminders alone are an effective way to encourage patients to record BP measurements. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

A programme for bidirectional phonology and phonetics and their acquisition and evolution

NARCIS (Netherlands)

Boersma, P.; Benz, A.; Mattausch, J.

2011-01-01

This paper summarizes an existing bidirectional six-level model of phonology and phonetics (and a bit of morphology). Bidirectionality in this case refers to the modelling of both the speaking process (production) and the listening process (comprehension). The elements of the grammar (the

Intrinsic Dynamics of Quantum-Dash Lasers

KAUST Repository

Chen, Cheng; Djie, Hery Susanto; Hwang, James C. M.; Koch, Thomas L.; Lester, Luke F.; Ooi, Boon S.; Wang, Yang

2011-01-01

Temperature-dependent intrinsic modulation response of InAs/InAlGaAs quantum-dash lasers was investigated by using pulse optical injection modulation to minimize the effects of parasitics and self-heating. Compared to typical quantum-well lasers, the quantum-dash lasers were found to have comparable differential gain but approximately twice the gain compression factor, probably due to carrier heating by free-carrier absorption, as opposed to stimulated transition. Therefore, the narrower modulation bandwidth of the quantum-dash lasers than that of quantum-well lasers was attributed to their higher gain compression factor. In addition, as expected, quantum-dash lasers with relatively long and uniform dashes exhibit higher temperature stability than quantum-well lasers. However, the lasers with relatively short and nonuniform dashes exhibit stronger temperature dependence, probably due to their higher surface-to-volume ratio and nonuniform dash sizes. © 2011 IEEE.

Intrinsic Dynamics of Quantum-Dash Lasers

KAUST Repository

Chen, Cheng

2011-10-01

Temperature-dependent intrinsic modulation response of InAs/InAlGaAs quantum-dash lasers was investigated by using pulse optical injection modulation to minimize the effects of parasitics and self-heating. Compared to typical quantum-well lasers, the quantum-dash lasers were found to have comparable differential gain but approximately twice the gain compression factor, probably due to carrier heating by free-carrier absorption, as opposed to stimulated transition. Therefore, the narrower modulation bandwidth of the quantum-dash lasers than that of quantum-well lasers was attributed to their higher gain compression factor. In addition, as expected, quantum-dash lasers with relatively long and uniform dashes exhibit higher temperature stability than quantum-well lasers. However, the lasers with relatively short and nonuniform dashes exhibit stronger temperature dependence, probably due to their higher surface-to-volume ratio and nonuniform dash sizes. © 2011 IEEE.

Network Coding in the Bidirectional Cross

DEFF Research Database (Denmark)

Ertli, Gergö; Paramanathan, Achuthan; Rein, Stephan Alexander

2013-01-01

This paper presents a detailed performance evaluation of inter-session network coding in wireless meshed networks in terms of throughput and energy consumption. A full analytical model is given for three different communication approaches for the bidirectional cross topology using an IEEE 802.11 ...

A New Bi-Directional Projection Model Based on Pythagorean Uncertain Linguistic Variable

Directory of Open Access Journals (Sweden)

Huidong Wang

2018-04-01

Full Text Available To solve the multi-attribute decision making (MADM problems with Pythagorean uncertain linguistic variable, an extended bi-directional projection method is proposed. First, we utilize the linguistic scale function to convert uncertain linguistic variable and provide a new projection model, subsequently. Then, to depict the bi-directional projection method, the formative vectors of alternatives and ideal alternatives are defined. Furthermore, a comparative analysis with projection model is conducted to show the superiority of bi-directional projection method. Finally, an example of graduate’s job option is given to demonstrate the effectiveness and feasibility of the proposed method.

Model based feasibility study on bidirectional check valves in wave energy converters

DEFF Research Database (Denmark)

Hansen, Anders Hedegaard; Pedersen, Henrik C.; Andersen, Torben Ole

2014-01-01

Discrete fluid power force systems have been proposed as the primary stage for Wave Energy Converters (WEC’s) when converting ocean waves into electricity, this to improve the overall efficiency of wave energy devices. This paper presents a model based feasibility study of using bidirectional check....../Off and bidirectional check valves. Based on the analysis it is found that the energy production may be slightly improved by using bidirectional check valves as compared to on/off valves, due to a decrease in switching losses. Furthermore a reduction in high flow peaks are realised. The downside being increased...

Featurized Bidirectional GAN: Adversarial Defense via Adversarially Learned Semantic Inference

OpenAIRE

Bao, Ruying; Liang, Sihang; Wang, Qingcan

2018-01-01

Deep neural networks have been demonstrated to be vulnerable to adversarial attacks, where small perturbations are intentionally added to the original inputs to fool the classifier. In this paper, we propose a defense method, Featurized Bidirectional Generative Adversarial Networks (FBGAN), to capture the semantic features of the input and filter the non-semantic perturbation. FBGAN is pre-trained on the clean dataset in an unsupervised manner, adversarially learning a bidirectional mapping b...

Bilateral Coordination Strategy of Supply Chain with Bidirectional Option Contracts under Inflation

Directory of Open Access Journals (Sweden)

Nana Wan

2015-01-01

Full Text Available As far as the price increase and the demand contraction caused by inflation are concerned, we establish a Stackelberg game model that incorporates bidirectional option contracts and the effect of inflation and derive the optimal ordering and production policies on a one-period two-stage supply chain composed of one supplier and one retailer. Through using the model of wholesale price contracts as the benchmark, we find that the introduction of bidirectional option contracts can benefit both the supplier and the retailer under inflation scenarios. Based on the conclusions drawn above, we design the bilateral coordination mechanism from the different perspective of two members involved and discuss how bidirectional option contracts should be set to achieve channel coordination under inflation scenarios. Through the sensitivity analysis, we illustrate the effect of inflation on the optimal decision variables and the optimal expected profits of the two parties with bidirectional option contracts.

Video Super-Resolution via Bidirectional Recurrent Convolutional Networks.

Science.gov (United States)

Huang, Yan; Wang, Wei; Wang, Liang

2018-04-01

Super resolving a low-resolution video, namely video super-resolution (SR), is usually handled by either single-image SR or multi-frame SR. Single-Image SR deals with each video frame independently, and ignores intrinsic temporal dependency of video frames which actually plays a very important role in video SR. Multi-Frame SR generally extracts motion information, e.g., optical flow, to model the temporal dependency, but often shows high computational cost. Considering that recurrent neural networks (RNNs) can model long-term temporal dependency of video sequences well, we propose a fully convolutional RNN named bidirectional recurrent convolutional network for efficient multi-frame SR. Different from vanilla RNNs, 1) the commonly-used full feedforward and recurrent connections are replaced with weight-sharing convolutional connections. So they can greatly reduce the large number of network parameters and well model the temporal dependency in a finer level, i.e., patch-based rather than frame-based, and 2) connections from input layers at previous timesteps to the current hidden layer are added by 3D feedforward convolutions, which aim to capture discriminate spatio-temporal patterns for short-term fast-varying motions in local adjacent frames. Due to the cheap convolutional operations, our model has a low computational complexity and runs orders of magnitude faster than other multi-frame SR methods. With the powerful temporal dependency modeling, our model can super resolve videos with complex motions and achieve well performance.

A high-damping magnetorheological elastomer with bi-directional magnetic-control modulus for potential application in seismology

Energy Technology Data Exchange (ETDEWEB)

Yu, Miao, E-mail: yumiao@cqu.edu.cn; Qi, Song; Fu, Jie; Zhu, Mi [Key Lab for Optoelectronic Technology and Systems, Ministry of Education, College of Optoelectronic Engineering, Chongqing University, Chongqing 400044 (China)

2015-09-14

A high-damping magnetorheological elastomer (MRE) with bi-directional magnetic-control modulus is developed. This MRE was synthesized by filling NdFeB particles into polyurethane (PU)/ epoxy (EP) interpenetrating network (IPN) structure. The anisotropic samples were prepared in a permanent magnetic field and magnetized in an electromagnetic field of 1 T. Dynamic mechanical responses of the MRE to applied magnetic fields are investigated through magneto-rheometer, and morphology of MREs is observed via scanning electron microscope (SEM). Test result indicates that when the test field orientation is parallel to that of the sample's magnetization, the shear modulus of sample increases. On the other hand, when the orientation is opposite to that of the sample's magnetization, shear modulus decreases. In addition, this PU/EP IPN matrix based MRE has a high-damping property, with high loss factor and can be controlled by applying magnetic field. It is expected that the high damping property and the ability of bi-directional magnetic-control modulus of this MRE offer promising advantages in seismologic application.

Energy-efficient three-phase bidirectional converter for grid-connected storage applications

International Nuclear Information System (INIS)

Colmenar-Santos, Antonio; Linares-Mena, Ana-Rosa; Velázquez, Jesús Fernández; Borge-Diez, David

2016-01-01

Highlights: • Storage control system developed based on AC DC three phase bidirectional converter. • Bidirectional AC DC converter for storage integration into distribution grids. • Efficiencies over 98% for values over 30% of the bidirectional converter rated power. • Sensitivity analysis of the parameters set by the transmission system operator. • Low-cost option for control and integration of new grid-connected storage systems. - Abstract: Grid connected energy storage systems are expected to play an essential role in the development of Smart Grids, providing, among other benefits, ancillary services to power grids. It is therefore crucial to design and develop control and conversion systems that represent the key instrument where intelligence for decision-making is applied, in order to validate and ensure its optimal operation as part and parcel of the electrical system. The present research describes the design and development of a battery energy storage system based on an AC-DC three-phase bidirectional converter capable of operating either in charge mode to store electrical energy, or in discharge mode to supply load demands. The design is modelled with MATLAB® Simulink® environment in order to evaluate the performance during load variations. Moreover, the assessment is complemented by a global sensitivity analysis for variations in the operating parameters set by the transmission system operator. The effectiveness of the simulation is confirmed by implementing the system and carrying out grid connection tests, obtaining efficiencies over 98% for values over the 30% of the bidirectional converter rated power.

Exact bidirectional X -wave solutions in fiber Bragg gratings

Science.gov (United States)

Efremidis, Nikolaos K.; Nye, Nicholas S.; Christodoulides, Demetrios N.

2017-10-01

We find exact solutions describing bidirectional pulses propagating in fiber Bragg gratings. They are derived by solving the coupled-mode theory equations and are expressed in terms of products of modified Bessel functions with algebraic functions. Depending on the values of the two free parameters, the general bidirectional X -wave solution can also take the form of a unidirectional pulse. We analyze the symmetries and the asymptotic properties of the solutions and also discuss additional waveforms that are obtained by interference of more than one solution. Depending on their parameters, such pulses can create a sharp focus with high contrast.

Mitochondrial Dynamics Mediated by Mitofusin 1 Is Required for POMC Neuron Glucose-Sensing and Insulin Release Control.

Science.gov (United States)

Ramírez, Sara; Gómez-Valadés, Alicia G; Schneeberger, Marc; Varela, Luis; Haddad-Tóvolli, Roberta; Altirriba, Jordi; Noguera, Eduard; Drougard, Anne; Flores-Martínez, Álvaro; Imbernón, Mónica; Chivite, Iñigo; Pozo, Macarena; Vidal-Itriago, Andrés; Garcia, Ainhoa; Cervantes, Sara; Gasa, Rosa; Nogueiras, Ruben; Gama-Pérez, Pau; Garcia-Roves, Pablo M; Cano, David A; Knauf, Claude; Servitja, Joan-Marc; Horvath, Tamas L; Gomis, Ramon; Zorzano, Antonio; Claret, Marc

2017-06-06

Proopiomelanocortin (POMC) neurons are critical sensors of nutrient availability implicated in energy balance and glucose metabolism control. However, the precise mechanisms underlying nutrient sensing in POMC neurons remain incompletely understood. We show that mitochondrial dynamics mediated by Mitofusin 1 (MFN1) in POMC neurons couple nutrient sensing with systemic glucose metabolism. Mice lacking MFN1 in POMC neurons exhibited defective mitochondrial architecture remodeling and attenuated hypothalamic gene expression programs during the fast-to-fed transition. This loss of mitochondrial flexibility in POMC neurons bidirectionally altered glucose sensing, causing abnormal glucose homeostasis due to defective insulin secretion by pancreatic β cells. Fed mice lacking MFN1 in POMC neurons displayed enhanced hypothalamic mitochondrial oxygen flux and reactive oxygen species generation. Central delivery of antioxidants was able to normalize the phenotype. Collectively, our data posit MFN1-mediated mitochondrial dynamics in POMC neurons as an intrinsic nutrient-sensing mechanism and unveil an unrecognized link between this subset of neurons and insulin release. Copyright © 2017 Elsevier Inc. All rights reserved.

Intrinsic disorder here, there, and everywhere, and nowhere to escape from it.

Science.gov (United States)

Uversky, Vladimir N

2017-09-01

The concept of protein intrinsic disorder persistently penetrates into all areas of modern protein science. It cannot be ignored anymore, and cannot be shrugged off, as it represents a vital feature (or, more correctly, a broad spectrum of important features), which, when added to and mixed with features arising from the well established protein structure-function paradigm, complete the picture of a functioning protein. The field of protein intrinsic disorder is very dynamic and fast developing. This Multi-Author Review represents a snapshot of this field by introducing some recent advances. Articles assembled in this Multi-Author Review introduce some of the new aspects of intrinsic disorder, outline some fascinating ideas related to the intrinsically disordered proteins, their structure, and functionality, and show challenges related to the analysis of proteins carrying intrinsic disorder.

Analysis of bi-directional piezoelectric-based converters for zero-voltage switching operation

DEFF Research Database (Denmark)

Ekhtiari, Marzieh; Zhang, Zhe; Andersen, Michael A. E.

2016-01-01

This paper deals with a thorough analysis of zerovoltage switching especially for bi-directional, inductorless, piezoelectric transformer-based switch-mode power supplies with a half-bridge topology. Practically, obtaining zero-voltage switching for all of the switches in a bi-directional piezoel......This paper deals with a thorough analysis of zerovoltage switching especially for bi-directional, inductorless, piezoelectric transformer-based switch-mode power supplies with a half-bridge topology. Practically, obtaining zero-voltage switching for all of the switches in a bi......-directional piezoelectric power converter is a difficult task. However, the analysis in this work will be convenient for overcoming this challenge. The analysis defines the zero-voltage region indicating the operating points whether or not soft switching can be met over the switching frequency and load range. For the first...... time, a comprehensive analysis is provided, which can be used as a design guideline for applying control techniques in order to drive switches in piezoelectric transformer-based converters. This study further conveys the proposed method to the region where all the switches can obtain soft switching...

Bidirectional communication in an HF hybrid organic/solution-processed metal-oxide RFID tag

NARCIS (Netherlands)

Myny, K.; Rockelé, M.; Chasin, A.; Pham, D.V.; Steiger, J.; Botnaras, S.; Weber, D.; Herold, B.; Ficker, J.; Van Putten, B.D.; Gelinck, G.H.; Genoe, J.; Dehaene, W.; Heremans, P.

2014-01-01

A bidirectional communication protocol allows radio-frequency identification (RFID) tags to have readout of multiple tags in the RF field without collision of data. In this paper, we realized bidirectional communication between a reader system and thin-film RFID tag by introducing a novel protocol

Uncertainties in the Bidirectional Biodiesel Supply Chain

NARCIS (Netherlands)

Bot, Pieter; van Donk, Dirk Pieter; Pennink, Bartjan; Simatupang, Togar M.

2015-01-01

For remote areas, small-scale local biodiesel production is particularly attractive if producers and consumers are the same. Such supply chains are labeled as bidirectional. However, little is known on how raw material supply, transportation, logistics, production and operations uncertainties impact

On Training Bi-directional Neural Network Language Model with Noise Contrastive Estimation

OpenAIRE

He, Tianxing; Zhang, Yu; Droppo, Jasha; Yu, Kai

2016-01-01

We propose to train bi-directional neural network language model(NNLM) with noise contrastive estimation(NCE). Experiments are conducted on a rescore task on the PTB data set. It is shown that NCE-trained bi-directional NNLM outperformed the one trained by conventional maximum likelihood training. But still(regretfully), it did not out-perform the baseline uni-directional NNLM.

Bidirectional Thermo-Mechanical Properties of Foam Core Materials Using DIC

DEFF Research Database (Denmark)

Taher, Siavash Talebi; Thomsen, Ole Thybo; M Dulieu-Barton, Janice

2011-01-01

mechanical properties at room and at elevated temperatures. The MAF enables the realization of pure compression or high compression to shear bidirectional loading conditions that is not possible with conventional Arcan fixtures. The MAF is attached to a standard universal test machine equiped...... with an environmental chamber using specially designed grips that allow the specimen to rotate, and hence reduces paristic effects due to misalignment. The objective is to measure the unidirectional and bidirectional mechanical properties of PVC foam materials at elevated tempreature using digital image correlation...

Dynamic analysis of suspension cable based on vector form intrinsic finite element method

Science.gov (United States)

Qin, Jian; Qiao, Liang; Wan, Jiancheng; Jiang, Ming; Xia, Yongjun

2017-10-01

A vector finite element method is presented for the dynamic analysis of cable structures based on the vector form intrinsic finite element (VFIFE) and mechanical properties of suspension cable. Firstly, the suspension cable is discretized into different elements by space points, the mass and external forces of suspension cable are transformed into space points. The structural form of cable is described by the space points at different time. The equations of motion for the space points are established according to the Newton’s second law. Then, the element internal forces between the space points are derived from the flexible truss structure. Finally, the motion equations of space points are solved by the central difference method with reasonable time integration step. The tangential tension of the bearing rope in a test ropeway with the moving concentrated loads is calculated and compared with the experimental data. The results show that the tangential tension of suspension cable with moving loads is consistent with the experimental data. This method has high calculated precision and meets the requirements of engineering application.

Dynamics of intrinsic electrophysiological properties in spinal cord neurones

DEFF Research Database (Denmark)

Russo, R E; Hounsgaard, J

1999-01-01

The spinal cord is engaged in a wide variety of functions including generation of motor acts, coding of sensory information and autonomic control. The intrinsic electrophysiological properties of spinal neurones represent a fundamental building block of the spinal circuits executing these tasks. ....... Specialised, cell specific electrophysiological phenotypes gradually differentiate during development and are continuously adjusted in the adult animal by metabotropic synaptic interactions and activity-dependent plasticity to meet a broad range of functional demands....

Implantable neurotechnologies: bidirectional neural interfaces--applications and VLSI circuit implementations.

Science.gov (United States)

Greenwald, Elliot; Masters, Matthew R; Thakor, Nitish V

2016-01-01

A bidirectional neural interface is a device that transfers information into and out of the nervous system. This class of devices has potential to improve treatment and therapy in several patient populations. Progress in very large-scale integration has advanced the design of complex integrated circuits. System-on-chip devices are capable of recording neural electrical activity and altering natural activity with electrical stimulation. Often, these devices include wireless powering and telemetry functions. This review presents the state of the art of bidirectional circuits as applied to neuroprosthetic, neurorepair, and neurotherapeutic systems.

A Novel PPFHB Bidirectional DC-DC Converter for Supercapacitor Application

DEFF Research Database (Denmark)

Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael Andreas E.

2009-01-01

This paper presents a novel bidirectional DC-DC converter for the supercapacitor application. In the proposed converter, push-pull forward with half bridge (PPFHB) voltage doubler structure is used to reduce the number of the power switches and get higher voltage gain. Based on phase-shift modula......This paper presents a novel bidirectional DC-DC converter for the supercapacitor application. In the proposed converter, push-pull forward with half bridge (PPFHB) voltage doubler structure is used to reduce the number of the power switches and get higher voltage gain. Based on phase...

Bidirectional optimization of the melting spinning process.

Science.gov (United States)

Liang, Xiao; Ding, Yongsheng; Wang, Zidong; Hao, Kuangrong; Hone, Kate; Wang, Huaping

2014-02-01

A bidirectional optimizing approach for the melting spinning process based on an immune-enhanced neural network is proposed. The proposed bidirectional model can not only reveal the internal nonlinear relationship between the process configuration and the quality indices of the fibers as final product, but also provide a tool for engineers to develop new fiber products with expected quality specifications. A neural network is taken as the basis for the bidirectional model, and an immune component is introduced to enlarge the searching scope of the solution field so that the neural network has a larger possibility to find the appropriate and reasonable solution, and the error of prediction can therefore be eliminated. The proposed intelligent model can also help to determine what kind of process configuration should be made in order to produce satisfactory fiber products. To make the proposed model practical to the manufacturing, a software platform is developed. Simulation results show that the proposed model can eliminate the approximation error raised by the neural network-based optimizing model, which is due to the extension of focusing scope by the artificial immune mechanism. Meanwhile, the proposed model with the corresponding software can conduct optimization in two directions, namely, the process optimization and category development, and the corresponding results outperform those with an ordinary neural network-based intelligent model. It is also proved that the proposed model has the potential to act as a valuable tool from which the engineers and decision makers of the spinning process could benefit.

Bidirectional ventricular tachycardia of unusual etiology

Directory of Open Access Journals (Sweden)

Praloy Chakraborty

2015-11-01

Full Text Available Bidirectional ventricular tachycardia (BDVT is a rare form of ventricular arrhythmia, characterized by changing QRS axis of 180 degrees. Digitalis toxicity is considered as commonest cause of BDVT; other causes include aconite toxicity, myocarditis, myocardial infarction, metastatic cardiac tumour and cardiac channelopathies. We describe a case of BDVT in a patient with Anderson-Tawil syndrome.

Bi-directional interhemispheric inhibition during unimanual sustained contractions

Directory of Open Access Journals (Sweden)

Ni Zhen

2009-04-01

Full Text Available Abstract Background The interaction between homologous muscle representations in the right and left primary motor cortex was studied using a paired-pulse transcranial magnetic stimulation (TMS protocol known to evoke interhemispheric inhibition (IHI. The timecourse and magnitude of IHI was studied in fifteen healthy right-handed adults at several interstimulus intervals between the conditioning stimulus and test stimulus (6, 8, 10, 12, 30, 40, 50 ms. IHI was studied in the motor dominant to non-dominant direction and vice versa while the right or left hand was at rest, performing isometric contraction of the first dorsal interosseous (FDI muscle, and isometric contraction of the FDI muscle in the context of holding a pen. Results Compared with rest, IHI was reduced at all ISIs during contraction of either type (with or without the context of pen. IHI was reduced bi-directionally without evidence of hemispheric dominance. Further, contraction of the hand contralateral to the conditioning and test pulse yielded similar reductions in IHI. Conclusion These data provide evidence for bi-directional reduction of IHI during unimanual contractions. During unimanual, sustained contractions of the hand, the contralateral and ipsilateral motor cortices demonstrate reduced inhibition. The data suggest that unimanual movement decreases inhibition bi-directionally across motor hemispheres and offer one explanation for the observation of ipsilateral M1 activity during hand movements.

Family of multiport bidirectional DC-DC converters

NARCIS (Netherlands)

Tao, H.; Kotsopoulos, A.; Duarte, J.L.; Hendrix, M.A.M.

2006-01-01

Multiport DC-DC converters are of potential interest in applications such as generation systems utilising multiple sustainable energy sources. A family of multiport bidirectional DC-DC converters derived from a general topology is presented. The topology shows a combination of DC-link and magnetic

Stochastic synchronization of neuronal populations with intrinsic and extrinsic noise.

KAUST Repository

Bressloff, Paul C; Lai, Yi Ming

2011-01-01

We extend the theory of noise-induced phase synchronization to the case of a neural master equation describing the stochastic dynamics of an ensemble of uncoupled neuronal population oscillators with intrinsic and extrinsic noise. The master

Bi-directional Multi Dimension CAP Transmission for Smart Grid Communication Services

DEFF Research Database (Denmark)

Zhang, Xu; Binti Othman, Maisara; Pang, Xiaodan

2012-01-01

We experimentally demonstrate bi-directional multi dimension carrierless amplitude and phase (CAP) transmission for smart grid communication services based on optical fiber networks. The proposed system is able to support multi-Gb/s transmission with high spectral efficiency.......We experimentally demonstrate bi-directional multi dimension carrierless amplitude and phase (CAP) transmission for smart grid communication services based on optical fiber networks. The proposed system is able to support multi-Gb/s transmission with high spectral efficiency....

Bi-directional magnetic resonance based wireless power transfer for electronic devices

International Nuclear Information System (INIS)

Kar, Durga P.; Nayak, Praveen P.; Bhuyan, Satyanarayan; Mishra, Debasish

2015-01-01

In order to power or charge electronic devices wirelessly, a bi-directional wireless power transfer method has been proposed and experimentally investigated. In the proposed design, two receiving coils are used on both sides of a transmitting coil along its central axis to receive the power wirelessly from the generated magnetic fields through strongly coupled magnetic resonance. It has been observed experimentally that the maximum power transfer occurs at the operating resonant frequency for optimum electric load connected across the receiving coils on both side. The optimum wireless power transfer efficiency is 88% for the bi-directional power transfer technique compared 84% in the one side receiver system. By adopting the developed bi-directional power transfer method, two electronic devices can be powered up or charged simultaneously instead of a single device through usual one side receiver system without affecting the optimum power transfer efficiency

Bi-directional magnetic resonance based wireless power transfer for electronic devices

Energy Technology Data Exchange (ETDEWEB)

Kar, Durga P.; Nayak, Praveen P.; Bhuyan, Satyanarayan; Mishra, Debasish [Department of Electronics and Instrumentation Engineering, Institute of Technical Education and Research, Siksha ‘O’ Anushandhan University, Bhubaneswar 751030 (India)

2015-09-28

In order to power or charge electronic devices wirelessly, a bi-directional wireless power transfer method has been proposed and experimentally investigated. In the proposed design, two receiving coils are used on both sides of a transmitting coil along its central axis to receive the power wirelessly from the generated magnetic fields through strongly coupled magnetic resonance. It has been observed experimentally that the maximum power transfer occurs at the operating resonant frequency for optimum electric load connected across the receiving coils on both side. The optimum wireless power transfer efficiency is 88% for the bi-directional power transfer technique compared 84% in the one side receiver system. By adopting the developed bi-directional power transfer method, two electronic devices can be powered up or charged simultaneously instead of a single device through usual one side receiver system without affecting the optimum power transfer efficiency.

Silent and Efficient Supersonic Bi-Directional Flying Wing

Data.gov (United States)

National Aeronautics and Space Administration — We propose a Phase I study for a novel concept of a supersonic bi-directional (SBiDir) flying wing (FW) that has the potential to revolutionize supersonic flight...

A bidirectional brain-machine interface algorithm that approximates arbitrary force-fields.

Directory of Open Access Journals (Sweden)

Alessandro Vato

Full Text Available We examine bidirectional brain-machine interfaces that control external devices in a closed loop by decoding motor cortical activity to command the device and by encoding the state of the device by delivering electrical stimuli to sensory areas. Although it is possible to design this artificial sensory-motor interaction while maintaining two independent channels of communication, here we propose a rule that closes the loop between flows of sensory and motor information in a way that approximates a desired dynamical policy expressed as a field of forces acting upon the controlled external device. We previously developed a first implementation of this approach based on linear decoding of neural activity recorded from the motor cortex into a set of forces (a force field applied to a point mass, and on encoding of position of the point mass into patterns of electrical stimuli delivered to somatosensory areas. However, this previous algorithm had the limitation that it only worked in situations when the position-to-force map to be implemented is invertible. Here we overcome this limitation by developing a new non-linear form of the bidirectional interface that can approximate a virtually unlimited family of continuous fields. The new algorithm bases both the encoding of position information and the decoding of motor cortical activity on an explicit map between spike trains and the state space of the device computed with Multi-Dimensional-Scaling. We present a detailed computational analysis of the performance of the interface and a validation of its robustness by using synthetic neural responses in a simulated sensory-motor loop.

Bidirectional communication using delay coupled chaotic directly ...

Indian Academy of Sciences (India)

A symmetric bidirectional coupling is identified as a suitable method for isochronal synchronization of such lasers. The optimum values of coupling and feedback strength that can provide maximum quality of synchronization are identified. This method is successfully employed for encoding/decoding both analog and digital ...

Intrinsically-generated fluctuating activity in excitatory-inhibitory networks

Science.gov (United States)

Mastrogiuseppe, Francesca; Ostojic, Srdjan

2017-01-01

Recurrent networks of non-linear units display a variety of dynamical regimes depending on the structure of their synaptic connectivity. A particularly remarkable phenomenon is the appearance of strongly fluctuating, chaotic activity in networks of deterministic, but randomly connected rate units. How this type of intrinsically generated fluctuations appears in more realistic networks of spiking neurons has been a long standing question. To ease the comparison between rate and spiking networks, recent works investigated the dynamical regimes of randomly-connected rate networks with segregated excitatory and inhibitory populations, and firing rates constrained to be positive. These works derived general dynamical mean field (DMF) equations describing the fluctuating dynamics, but solved these equations only in the case of purely inhibitory networks. Using a simplified excitatory-inhibitory architecture in which DMF equations are more easily tractable, here we show that the presence of excitation qualitatively modifies the fluctuating activity compared to purely inhibitory networks. In presence of excitation, intrinsically generated fluctuations induce a strong increase in mean firing rates, a phenomenon that is much weaker in purely inhibitory networks. Excitation moreover induces two different fluctuating regimes: for moderate overall coupling, recurrent inhibition is sufficient to stabilize fluctuations; for strong coupling, firing rates are stabilized solely by the upper bound imposed on activity, even if inhibition is stronger than excitation. These results extend to more general network architectures, and to rate networks receiving noisy inputs mimicking spiking activity. Finally, we show that signatures of the second dynamical regime appear in networks of integrate-and-fire neurons. PMID:28437436

Block-classified bidirectional motion compensation scheme for wavelet-decomposed digital video

Energy Technology Data Exchange (ETDEWEB)

Zafar, S. [Argonne National Lab., IL (United States). Mathematics and Computer Science Div.; Zhang, Y.Q. [David Sarnoff Research Center, Princeton, NJ (United States); Jabbari, B. [George Mason Univ., Fairfax, VA (United States)

1997-08-01

In this paper the authors introduce a block-classified bidirectional motion compensation scheme for the previously developed wavelet-based video codec, where multiresolution motion estimation is performed in the wavelet domain. The frame classification structure described in this paper is similar to that used in the MPEG standard. Specifically, the I-frames are intraframe coded, the P-frames are interpolated from a previous I- or a P-frame, and the B-frames are bidirectional interpolated frames. They apply this frame classification structure to the wavelet domain with variable block sizes and multiresolution representation. They use a symmetric bidirectional scheme for the B-frames and classify the motion blocks as intraframe, compensated either from the preceding or the following frame, or bidirectional (i.e., compensated based on which type yields the minimum energy). They also introduce the concept of F-frames, which are analogous to P-frames but are predicted from the following frame only. This improves the overall quality of the reconstruction in a group of pictures (GOP) but at the expense of extra buffering. They also study the effect of quantization of the I-frames on the reconstruction of a GOP, and they provide intuitive explanation for the results. In addition, the authors study a variety of wavelet filter-banks to be used in a multiresolution motion-compensated hierarchical video codec.

Bidirectional relations between work-related stress, sleep quality and perseverative cognition.

Science.gov (United States)

Van Laethem, Michelle; Beckers, Debby G J; Kompier, Michiel A J; Kecklund, Göran; van den Bossche, Seth N J; Geurts, Sabine A E

2015-11-01

In this longitudinal two-wave study, bidirectional relations between work-related stress and sleep quality were examined. Moreover, it was investigated whether perseverative cognition is a potential underlying mechanism in this association, related to both work-related stress and sleep quality. A randomly selected sample of Dutch employees received an online survey in 2012 and 2013. Of all invited employees, 877 participated in both waves. Structural equation modeling was performed to analyze the data. We found evidence for reversed relations between work-related stress and sleep quality. Specifically, when controlling for perseverative cognition, work-related stress was not directly related to subsequent sleep quality, but low sleep quality was associated with an increase in work-related stress over time. Moreover, negative bidirectional associations over time were found between perseverative cognition and sleep quality, and positive bidirectional associations were found between work-related stress and perseverative cognition. Lastly, a mediation analysis showed that perseverative cognition fully mediated the relationship between work-related stress and sleep quality. The study findings suggest that perseverative cognition could be an important underlying mechanism in the association between work-related stress and sleep quality. The bidirectionality of the studied relationships could be an indication of a vicious cycle, in which work-related stress, perseverative cognition, and sleep quality mutually influence each other over time. Copyright © 2015 Elsevier Inc. All rights reserved.

Personalized recommendation based on heat bidirectional transfer

Science.gov (United States)

Ma, Wenping; Feng, Xiang; Wang, Shanfeng; Gong, Maoguo

2016-02-01

Personalized recommendation has become an increasing popular research topic, which aims to find future likes and interests based on users' past preferences. Traditional recommendation algorithms pay more attention to forecast accuracy by calculating first-order relevance, while ignore the importance of diversity and novelty that provide comfortable experiences for customers. There are some levels of contradictions between these three metrics, so an algorithm based on bidirectional transfer is proposed in this paper to solve this dilemma. In this paper, we agree that an object that is associated with history records or has been purchased by similar users should be introduced to the specified user and recommendation approach based on heat bidirectional transfer is proposed. Compared with the state-of-the-art approaches based on bipartite network, experiments on two benchmark data sets, Movielens and Netflix, demonstrate that our algorithm has better performance on accuracy, diversity and novelty. Moreover, this method does better in exploiting long-tail commodities and cold-start problem.

Spatial separation and bidirectional trafficking of proteins using a multi-functional reporter

Directory of Open Access Journals (Sweden)

Klaubert Dieter H

2008-04-01

Full Text Available Abstract Background The ability to specifically label proteins within living cells can provide information about their dynamics and function. To study a membrane protein, we fused a multi-functional reporter protein, HaloTag®, to the extracellular domain of a truncated integrin. Results Using the HaloTag technology, we could study the localization, trafficking and processing of an integrin-HaloTag fusion, which we showed had cellular dynamics consistent with native integrins. By labeling live cells with different fluorescent impermeable and permeable ligands, we showed spatial separation of plasma membrane and internal pools of the integrin-HaloTag fusion, and followed these protein pools over time to study bi-directional trafficking. In addition to combining the HaloTag reporter protein with different fluorophores, we also employed an affinity tag to achieve cell capture. Conclusion The HaloTag technology was used successfully to study expression, trafficking, spatial separation and real-time translocation of an integrin-HaloTag fusion, thereby demonstrating that this technology can be a powerful tool to investigate membrane protein biology in live cells.

Synchronization and bidirectional communication without delay line using strong mutually coupled semiconductor lasers

Science.gov (United States)

Li, Guang-Hui; Wang, An-Bang; Feng, Ye; Wang, Yang

2010-07-01

This paper numerically demonstrates synchronization and bidirectional communication without delay line by using two semiconductor lasers with strong mutual injection in a face-to-face configuration. These results show that both of the two lasers' outputs synchronize with their input chaotic carriers. In addition, simulations demonstrate that this kind of synchronization can be used to realize bidirectional communications without delay line. Further studies indicate that within a small deviation in message amplitudes of two sides (±6%), the message can be extracted with signal-noise-ratio more than 10 dB; and the signal-noise-ratio is extremely sensitive to the message rates mismatch of two sides, which may be used as a key of bidirectional communication.

Synchronization and bidirectional communication without delay line using strong mutually coupled semiconductor lasers

International Nuclear Information System (INIS)

Guang-Hui, Li; An-Bang, Wang; Ye, Feng; Yang, Wang

2010-01-01

This paper numerically demonstrates synchronization and bidirectional communication without delay line by using two semiconductor lasers with strong mutual injection in a face-to-face configuration. These results show that both of the two lasers' outputs synchronize with their input chaotic carriers. In addition, simulations demonstrate that this kind of synchronization can be used to realize bidirectional communications without delay line. Further studies indicate that within a small deviation in message amplitudes of two sides (±6%), the message can be extracted with signal-noise-ratio more than 10 dB; and the signal-noise-ratio is extremely sensitive to the message rates mismatch of two sides, which may be used as a key of bidirectional communication. (general)

A Bidirectional Multi-Port DC-DC Converter Integrating Voltage Equalizer

DEFF Research Database (Denmark)

Chen, Jianfei; Hou, Shiying; Deng, Fujin

2015-01-01

A novel bidirectional multi-port dc-dc converter integrating voltage equalizer based on switched-capacitor voltage accumulator (SCVA) is proposed. It has two operating modes of charging and discharging for battery modules. All battery modules are connected in series indirectly and can be equalize...... battery modules with different voltages. Simulation results has shown the feasibility of the proposed converter.......A novel bidirectional multi-port dc-dc converter integrating voltage equalizer based on switched-capacitor voltage accumulator (SCVA) is proposed. It has two operating modes of charging and discharging for battery modules. All battery modules are connected in series indirectly and can be equalized...

A New Bi-Directional Projection Model Based on Pythagorean Uncertain Linguistic Variable

OpenAIRE

Huidong Wang; Shifan He; Xiaohong Pan

2018-01-01

To solve the multi-attribute decision making (MADM) problems with Pythagorean uncertain linguistic variable, an extended bi-directional projection method is proposed. First, we utilize the linguistic scale function to convert uncertain linguistic variable and provide a new projection model, subsequently. Then, to depict the bi-directional projection method, the formative vectors of alternatives and ideal alternatives are defined. Furthermore, a comparative analysis with projection model is co...

Nanotechnology to rescue bacterial bidirectional extracellular electron transfer in bioelectrochemical systems

KAUST Repository

Kalathil, Shafeer

2016-03-17

An electrically active bacterium transports its metabolically generated electrons to insoluble substrates such as electrodes via a process known as extracellular electron transport (EET). Bacterial EET is a crucial process in the geochemical cycling of metals, bioremediation and bioenergy devices such as microbial fuel cells (MFCs). Recently, it has been found that electroactive bacteria can reverse their respiratory pathways by accepting electrons from a negatively poised electrode to produce high-value chemicals such as ethanol in a process termed as microbial electrosynthesis (MES). A poor electrical connection between bacteria and the electrode hinders the EET and MES processes significantly. Also, the bidirectional EET process is sluggish and needs to be improved drastically to extend its practical applications. Several attempts have been undertaken to improve the bidirectional EET by employing various advanced nanostructured materials such as carbon nanotubes and graphene. This review covers the recent progress in the bacterial bidirectional EET processes using advanced nanostructures in the light of current understandings of bacteria–nanomaterial interactions.

Bidirectional User Throughput Maximization Based on Feedback Reduction in LiFi Networks

OpenAIRE

Soltani, Mohammad Dehghani; Wu, Xiping; Safari, Majid; Haas, Harald

2017-01-01

Channel adaptive signalling, which is based on feedback, can result in almost any performance metric enhancement. Unlike the radio frequency (RF) channel, the optical wireless communications (OWCs) channel is fairly static. This feature enables a potential improvement of the bidirectional user throughput by reducing the amount of feedback. Light-Fidelity (LiFi) is a subset of OWCs, and it is a bidirectional, high-speed and fully networked wireless communication technology where visible light ...

Dynamic reciprocity in bio-inspired supramolecular materials

NARCIS (Netherlands)

Bastings, M.M.C.

2012-01-01

Dynamic reciprocity, the spatio-temporal bidirectional process between evolving partners in a functional system is not only found in nature, but also applies to supramolecularly assembling architectures. In this thesis, the focus was on the understanding of nature-inspired supramolecular

Bidirectional pulser made from pulse lines for linear induction accelerators

International Nuclear Information System (INIS)

Hotta, E.; Mori, T.; Kobayashi, T.; Okino, A.; Haginomori, E.; Ko, K.C.

1996-01-01

In order to obtain high-current charged particle beams, linear induction accelerators (LIA's) of two types have been already constructed. Conventional LIA's adopt a unidirectional pulse injected from an external pulser. The other LIA's, one of which has been proposed and constructed by Pavlovskii et al., have accelerating cavities made from pulse forming lines (PFL's). In this case, no magnetic core loaded in the cavity is necessary. However, the injected pulse must be a bidirectional one. Since a part of the voltage pulse with reversed polarity is used to accelerate a beam, it is possible to make the time integral of the output voltage zero. Thus the final magnetic energy stored in the cavity can be made zero at the end of the pulse, and the pulser-accelerator system attains the energy transfer efficiency of 100%. Accelerators of this type can be divided into two kinds, one of which has cavities with internal energy storage, and the other has cavities with energy injected from external bidirectional pulsers. The accelerator of latter type has been first proposed by Smith, but it has not been realized. Several bidirectional pulsers, which consist of three individual PFL's with arbitrary impedances and a closing switch, are analyzed. Output voltages are analytically calculated by using the method proposed by Dommel for digital computations of electromagnetic transients in networks, and conditions for attaining the maximum efficiency of energy transfer from the pulser to the beam are derived. Thus, 4 bidirectional pulsers of internal energy storage type and 2 of external pulse injection type with energy transfer efficiency of 100% are obtained, including the pulsers already reported by other authors

Bidirectional electric communication between the inferior occipital gyrus and the amygdala during face processing.

Science.gov (United States)

Sato, Wataru; Kochiyama, Takanori; Uono, Shota; Matsuda, Kazumi; Usui, Keiko; Usui, Naotaka; Inoue, Yushi; Toichi, Motomi

2017-09-01

Faces contain multifaceted information that is important for human communication. Neuroimaging studies have revealed face-specific activation in multiple brain regions, including the inferior occipital gyrus (IOG) and amygdala; it is often assumed that these regions constitute the neural network responsible for the processing of faces. However, it remains unknown whether and how these brain regions transmit information during face processing. This study investigated these questions by applying dynamic causal modeling of induced responses to human intracranial electroencephalography data recorded from the IOG and amygdala during the observation of faces, mosaics, and houses in upright and inverted orientations. Model comparisons assessing the experimental effects of upright faces versus upright houses and upright faces versus upright mosaics consistently indicated that the model having face-specific bidirectional modulatory effects between the IOG and amygdala was the most probable. The experimental effect between upright versus inverted faces also favored the model with bidirectional modulatory effects between the IOG and amygdala. The spectral profiles of modulatory effects revealed both same-frequency (e.g., gamma-gamma) and cross-frequency (e.g., theta-gamma) couplings. These results suggest that the IOG and amygdala communicate rapidly with each other using various types of oscillations for the efficient processing of faces. Hum Brain Mapp 38:4511-4524, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Comparative Study on Uni- and Bi-Directional Fluid Structure Coupling of Wind Turbine Blades

Directory of Open Access Journals (Sweden)

Mesfin Belayneh Ageze

2017-09-01

Full Text Available The current trends of wind turbine blade designs are geared towards a longer and slender blade with high flexibility, exhibiting complex aeroelastic loadings and instability issues, including flutter; in this regard, fluid-structure interaction (FSI plays a significant role. The present article will conduct a comparative study between uni-directional and bi-directional fluid-structural coupling models for a horizontal axis wind turbine. A full-scale, geometric copy of the NREL 5MW blade with simplified material distribution is considered for simulation. Analytical formulations of the governing relations with appropriate approximation are highlighted, including turbulence model, i.e., Shear Stress Transport (SST k-ω. These analytical relations are implemented using Multiphysics package ANSYS employing Fluent module (Computational Fluid Dynamics (CFD-based solver for the fluid domain and Transient Structural module (Finite Element Analysis-based solver for the structural domain. ANSYS system coupling module also is configured to model the two fluid-structure coupling methods. The rated operational condition of the blade for a full cycle rotation is considered as a comparison domain. In the bi-directional coupling model, the structural deformation alters the angle of attack from the designed values, and by extension the flow pattern along the blade span; furthermore, the tip deflection keeps fluctuating whilst it tends to stabilize in the uni-directional coupling model.

Strong electron bidirectional anisotropies in the distant tail: ISEE 3 observations of polar rain

International Nuclear Information System (INIS)

Baker, D.N.; Bame, S.J.; Feldman, W.C.; Gosling, J.T.; Zwickl, R.D.; Slavin, J.A.; Smith, E.J.

1986-01-01

A detailed observational treatment of bidirectional electrons (--50 to 50 eV)in the distant magnetotail (rapprox. >100 R/sub E/) is presented. It is found that electrons in this energy range commonly exhibit strong, field-aligned anisotropies in the tail lobes. Because of large tail motions, the ISEE 3 data provide extensive sampling of both the north and south lobes in rapid succession. These data demonstrate directly the strong asymmetries that exist between the north and south lobes at any one time. The bidirectional fluxes are found to occur predominantly in the lobe directly connected to the sunward interplanetary magnetic field in the open magnetosphere model (north lobe for away sectors and south lobe for toward sectors). Electron anisotropy and magnetic field data are presented which show the transition from unidirectional (sheath) electron populations to bidirectional (lobe) populations. Thus we demonstrate the open nature of the distant magnetopause and show that the source of the higher-energy, bidirectional lobe electrons is the tailward directed electron heat flux population in the distant magnetosheath. Taken together, the present evidence suggests that the bidirectional electrons that we observe in the distant tail are closely related to the polar rain electrons observed previously at lower altitudes. Furthermore, these data provide strong evidence that the distant tail is composed largely of open magnetic field lines in contradistinction to some recently advanced models

5W1H Information Extraction with CNN-Bidirectional LSTM

Science.gov (United States)

Nurdin, A.; Maulidevi, N. U.

2018-03-01

In this work, information about who, did what, when, where, why, and how on Indonesian news articles were extracted by combining Convolutional Neural Network and Bidirectional Long Short-Term Memory. Convolutional Neural Network can learn semantically meaningful representations of sentences. Bidirectional LSTM can analyze the relations among words in the sequence. We also use word embedding word2vec for word representation. By combining these algorithms, we obtained F-measure 0.808. Our experiments show that CNN-BLSTM outperforms other shallow methods, namely IBk, C4.5, and Naïve Bayes with the F-measure 0.655, 0.645, and 0.595, respectively.

Bidirectional electron anisotropies in the distant tail: ISEE-3 observations of polar rain

International Nuclear Information System (INIS)

Baker, D.N.; Bame, S.J.; Feldman, W.C.; Gosling, J.T.; Zwickl, R.D.; Slavin, J.A.; Smith, E.J.

1985-01-01

A detailed observational treatment of bidirectional electrons (50 approx.500 eV) in the distant magnetotail (r greater than or equal to 100 R/sub E/) is presented. It is found that electrons in this energy range commonly exhibit strong, field-aligned anisotropies in the tail lobes. Because of large tail motions, the ISEE-3 data provide extensive sampling of both the north and south lobes in rapid succession, demonstrating directly the strong asymmetries that exist between the north and south lobes at any one time. The bidirectional fluxes are found to occur predominantly in the lobe directly connected to the sunward IMF in the open magnetosphere model (north lobe for away sectors and south lobe for toward sectors). Electron anisotropy and magnetic field data are presented which show the transition from unidirectional (sheath) electron populations to bidirectional (lobe) populations. Taken together, the present evidence suggests that the bidirectional electrons that we observe in the distant tail are closely related to the polar rain electrons observed previously at lower altitudes. Furthermore, these data provide strong evidence that the distant tail is comprised largely of open magnetic field lines in contradistinction to some recently advanced models

Analysis of intrinsic and extrinsic factors influencing the dynamics of bovine Eimeria spp. from central-eastern Poland.

Science.gov (United States)

Tomczuk, Krzysztof; Grzybek, Maciej; Szczepaniak, Klaudiusz; Studzińska, Maria; Demkowska-Kutrzepa, Marta; Roczeń-Karczmarz, Monika; Klockiewicz, Maciej

2015-11-30

Eimeria infections are common in cattle worldwide, however, little is known about the invasion dynamics of this unicellular parasite. Therefore, the aim of this study was to analyze intrinsic (host age) and extrinsic (herd size and management system) factors influencing the dynamics of Eimeria spp. found in calves from CE Poland. Fecal samples were collected from 356 calves from different types of management systems and from different herd sizes. Flotation and McMaster method were used for parasitological investigation. Oocysts were differentiated on the basis of morphological criteria. Eight Eimeria species were identified and mean species richness (MSR) was significantly affected by host age. The highest MSR was noted for middle age animals. There was an association between species, with a highly significant co-occurrence of Eimeria bovis with Eimeria zuernii. The presence of E. bovis significantly increased the percentage of individuals carrying E. zuernii. The presence of E. bovis significantly increased the percentage of individuals carrying Eimeria canadensis. The overall prevalence of Eimeria spp. reached 52.8% and was significantly affected by the age of cows, with the highest prevalence in animals between 5-10 months old. The most prevalent species were E. bovis (37.4%), E. zuernii (19.9%) and E. canadensis (12.1%). The prevalence of E. bovis was affected by host age (the highest prevalence in age class 2 animals) and management type (the highest prevalence in individuals raised in groups). The prevalence of E. zuernii was affected by age (the lowest prevalence was noted in the oldest individuals) and herd size (individuals infected were present only in the middle and large size herds), whereas the prevalence of E. canadensis was affected by all three factors. Overall, mean OPG of the combined Eimeria spp. was 458.84 (37.93) and differed significantly between age classes. Mean OPGs were generally low for young and mature animals but high for middle age

Bidirectional soliton spectral tunneling effects in the regime of optical event horizon

DEFF Research Database (Denmark)

Gu, Jie; Guo, Hairun; Wang, Shaofei

2015-01-01

We study the cross-phase-modulation-induced soliton spectral shifting in the regime of the optical event horizon. The perturbed soliton to either red-shifting or blue-shifting is controllable, which could evoke bidirectional soliton spectral tunneling effects.......We study the cross-phase-modulation-induced soliton spectral shifting in the regime of the optical event horizon. The perturbed soliton to either red-shifting or blue-shifting is controllable, which could evoke bidirectional soliton spectral tunneling effects....

Bidirectional Relationship between Cognitive Function and Pneumonia

Science.gov (United States)

Shah, Faraaz Ali; Pike, Francis; Alvarez, Karina; Angus, Derek; Newman, Anne B.; Lopez, Oscar; Tate, Judith; Kapur, Vishesh; Wilsdon, Anthony; Krishnan, Jerry A.; Hansel, Nadia; Au, David; Avdalovic, Mark; Fan, Vincent S.; Barr, R. Graham

2013-01-01

Rationale: Relationships between chronic health conditions and acute infections remain poorly understood. Preclinical studies suggest crosstalk between nervous and immune systems. Objectives: To determine bidirectional relationships between cognition and pneumonia. Methods: We conducted longitudinal analyses of a population-based cohort over 10 years. We determined whether changes in cognition increase risk of pneumonia hospitalization by trajectory analyses and joint modeling. We then determined whether pneumonia hospitalization increased risk of subsequent dementia using a Cox model with pneumonia as a time-varying covariate. Measurements and Main Results: Of the 5,888 participants, 639 (10.9%) were hospitalized with pneumonia at least once. Most participants had normal cognition before pneumonia. Three cognition trajectories were identified: no, minimal, and severe rapid decline. A greater proportion of participants hospitalized with pneumonia were on trajectories of minimal or severe decline before occurrence of pneumonia compared with those never hospitalized with pneumonia (proportion with no, minimal, and severe decline were 67.1%, 22.8%, and 10.0% vs. 76.0%, 19.3%, and 4.6% for participants with and without pneumonia, respectively; P pneumonia, even in those with normal cognition and physical function before pneumonia (β = −0.02; P pneumonia were subsequently at an increased risk of dementia (hazard ratio, 2.24 [95% confidence interval, 1.62–3.11]; P = 0.01). Associations were independent of demographics, health behaviors, other chronic conditions, and physical function. Bidirectional relationship did not vary based on severity of disease, and similar associations were noted for those with severe sepsis and other infections. Conclusions: A bidirectional relationship exists between pneumonia and cognition and may explain how a single episode of infection in well-appearing older individuals accelerates decline in chronic health conditions and loss of

Spatiotemporal neural network dynamics for the processing of dynamic facial expressions

Science.gov (United States)

Sato, Wataru; Kochiyama, Takanori; Uono, Shota

2015-01-01

The dynamic facial expressions of emotion automatically elicit multifaceted psychological activities; however, the temporal profiles and dynamic interaction patterns of brain activities remain unknown. We investigated these issues using magnetoencephalography. Participants passively observed dynamic facial expressions of fear and happiness, or dynamic mosaics. Source-reconstruction analyses utilizing functional magnetic-resonance imaging data revealed higher activation in broad regions of the bilateral occipital and temporal cortices in response to dynamic facial expressions than in response to dynamic mosaics at 150–200 ms and some later time points. The right inferior frontal gyrus exhibited higher activity for dynamic faces versus mosaics at 300–350 ms. Dynamic causal-modeling analyses revealed that dynamic faces activated the dual visual routes and visual–motor route. Superior influences of feedforward and feedback connections were identified before and after 200 ms, respectively. These results indicate that hierarchical, bidirectional neural network dynamics within a few hundred milliseconds implement the processing of dynamic facial expressions. PMID:26206708

Spatiotemporal neural network dynamics for the processing of dynamic facial expressions.

Science.gov (United States)

Sato, Wataru; Kochiyama, Takanori; Uono, Shota

2015-07-24

The dynamic facial expressions of emotion automatically elicit multifaceted psychological activities; however, the temporal profiles and dynamic interaction patterns of brain activities remain unknown. We investigated these issues using magnetoencephalography. Participants passively observed dynamic facial expressions of fear and happiness, or dynamic mosaics. Source-reconstruction analyses utilizing functional magnetic-resonance imaging data revealed higher activation in broad regions of the bilateral occipital and temporal cortices in response to dynamic facial expressions than in response to dynamic mosaics at 150-200 ms and some later time points. The right inferior frontal gyrus exhibited higher activity for dynamic faces versus mosaics at 300-350 ms. Dynamic causal-modeling analyses revealed that dynamic faces activated the dual visual routes and visual-motor route. Superior influences of feedforward and feedback connections were identified before and after 200 ms, respectively. These results indicate that hierarchical, bidirectional neural network dynamics within a few hundred milliseconds implement the processing of dynamic facial expressions.

A New Control Method for a Bi-Directional Phase-Shift-Controlled DC-DC Converter with an Extended Load Range

Directory of Open Access Journals (Sweden)

Wenzheng Xu

2017-10-01

Full Text Available Phase-shifted converters are practically important to provide high conversion efficiencies through soft-switching techniques. However, the limitation on a resonant inductor current in the converters often leads to a non-fulfillment of the requirement of minimum load current. This paper presents a new power electronics control technique to enable the dual features of bi-directional power flow and an extended load range for soft-switching in phase-shift-controlled DC-DC converters. The proposed technique utilizes two identical full bridge converters and inverters in conjunction with a new control logic for gate-driving signals to facilitate both Zero Current Switching (ZCS and Zero Voltage Switching (ZVS in a single phase-shift-controlled DC-DC converter. The additional ZCS is designed for light load conditions at which the minimum load current cannot be attained. The bi-directional phase-shift-controlled DC-DC converter can implement the function of synchronous rectification. Its fast dynamic response allows for quick energy recovery during the regenerative braking of traction systems in electrified trains.

Parenting and children's externalizing behavior: Bidirectionality during toddlerhood

NARCIS (Netherlands)

Verhoeven, Marjolein; Junger, Marianne; van Aken, Chantal; Dekovic, Maja; van Aken, Marcel A.G.

2010-01-01

This study examined the bidirectional relationship between parenting and boys' externalizing behaviors in a four-wave longitudinal study of toddlers. Participants were 104 intact two-parent families with toddler sons. When their sons were 17, 23, 29, and 35 months of age, mothers and fathers

A Current-Fed Isolated Bidirectional DC-DC Converter

DEFF Research Database (Denmark)

Sun, Xiaofeng; Wu, Xiaoying; Shen, Yanfeng

2017-01-01

This paper proposes a current-fed isolated bidirectional DC-DC converter (CF-IBDC) which has the advantages of wide input voltage range, low input current ripple, low conduction losses, and soft switching over the full operating range. Compared with conventional CF-IBDCs, the voltage spikes...

Role of "intrinsic charm" in semileptonic B-meson decays

CERN Document Server

Breidenbach, C; Mannel, T; Turczyk, S

2008-01-01

We discuss the role of so-called "intrinsic-charm" operators in semi-leptonic B-meson decays, which appear first at order 1/m_b^3 in the heavy quark expansion. We show by explicit calculation that -- at scales mu <= m_c -- the contributions from "intrinsic-charm" effects can be absorbed into short-distance coefficient functions multiplying, for instance, the Darwin term. Then, the only remnant of "intrinsic charm" are logarithms of the form ln(m_c^2/m_b^2), which can be resummed by using renormalization-group techniques. As long as the dynamics at the charm-quark scale is perturbative, alpha_s(m_c) << 1, this implies that no additional non-perturbative matrix elements aside from the Darwin and the spin-orbit term have to be introduced at order 1/m_b^3. Hence, no sources for additional hadronic uncertainties have to be taken into account. Similar arguments may be made for higher orders in the 1/m_b expansion.

Evolution of bidirectional sex change and gonochorism in fishes of the gobiid genera Trimma, Priolepis, and Trimmatom

Science.gov (United States)

Sunobe, Tomoki; Sado, Tetsuya; Hagiwara, Kiyoshi; Manabe, Hisaya; Suzuki, Toshiyuki; Kobayashi, Yasuhisa; Sakurai, Makoto; Dewa, Shin-ichi; Matsuoka, Midori; Shinomiya, Akihiko; Fukuda, Kazuya; Miya, Masaki

2017-04-01

Size-advantage and low-density models have been used to explain how mating systems favor hermaphroditism or gonochorism. However, these models do not indicate historical transitions in sexuality. Here, we investigate the evolution of bidirectional sex change and gonochorism by phylogenetic analysis using the mitochondrial gene of the gobiids Trimma (31 species), Priolepis (eight species), and Trimmatom (two species). Trimma and Priolepis formed a clade within the sister group Trimmatom. Gonadal histology and rearing experiments revealed that Trimma marinae, Trimma nasa, and Trimmatom spp. were gonochoric, whereas all other Trimma and Priolepis spp. were bidirectional sex changers or inferred ones. A maximum-likelihood reconstruction analysis demonstrated that the common ancestor of the three genera was gonochoristic. Bidirectional sex change probably evolved from gonochorism in a common ancestor of Trimma and Priolepis. As the gonads of bidirectional sex changers simultaneously contain mature ovarian and immature testicular components or vice versa, individuals are always potentially capable of functioning as females or males, respectively. Monogamy under low-density conditions may have been the ecological condition for the evolution of bidirectional sex change in a common ancestor. As T. marinae and T. nasa are a monophyletic group, gonochorism should have evolved from bidirectional sex change in a common ancestor.

Microsecond molecular dynamics simulations of intrinsically disordered proteins involved in the oxidative stress response.

Directory of Open Access Journals (Sweden)

Elio A Cino

Full Text Available Intrinsically disordered proteins (IDPs are abundant in cells and have central roles in protein-protein interaction networks. Interactions between the IDP Prothymosin alpha (ProTα and the Neh2 domain of Nuclear factor erythroid 2-related factor 2 (Nrf2, with a common binding partner, Kelch-like ECH-associated protein 1(Keap1, are essential for regulating cellular response to oxidative stress. Misregulation of this pathway can lead to neurodegenerative diseases, premature aging and cancer. In order to understand the mechanisms these two disordered proteins employ to bind to Keap1, we performed extensive 0.5-1.0 microsecond atomistic molecular dynamics (MD simulations and isothermal titration calorimetry experiments to investigate the structure/dynamics of free-state ProTα and Neh2 and their thermodynamics of bindings. The results show that in their free states, both ProTα and Neh2 have propensities to form bound-state-like β-turn structures but to different extents. We also found that, for both proteins, residues outside the Keap1-binding motifs may play important roles in stabilizing the bound-state-like structures. Based on our findings, we propose that the binding of disordered ProTα and Neh2 to Keap1 occurs synergistically via preformed structural elements (PSEs and coupled folding and binding, with a heavy bias towards PSEs, particularly for Neh2. Our results provide insights into the molecular mechanisms Neh2 and ProTα bind to Keap1, information that is useful for developing therapeutics to enhance the oxidative stress response.

Dynamics of neural cryptography.

Science.gov (United States)

Ruttor, Andreas; Kinzel, Wolfgang; Kanter, Ido

2007-05-01

Synchronization of neural networks has been used for public channel protocols in cryptography. In the case of tree parity machines the dynamics of both bidirectional synchronization and unidirectional learning is driven by attractive and repulsive stochastic forces. Thus it can be described well by a random walk model for the overlap between participating neural networks. For that purpose transition probabilities and scaling laws for the step sizes are derived analytically. Both these calculations as well as numerical simulations show that bidirectional interaction leads to full synchronization on average. In contrast, successful learning is only possible by means of fluctuations. Consequently, synchronization is much faster than learning, which is essential for the security of the neural key-exchange protocol. However, this qualitative difference between bidirectional and unidirectional interaction vanishes if tree parity machines with more than three hidden units are used, so that those neural networks are not suitable for neural cryptography. In addition, the effective number of keys which can be generated by the neural key-exchange protocol is calculated using the entropy of the weight distribution. As this quantity increases exponentially with the system size, brute-force attacks on neural cryptography can easily be made unfeasible.

Dynamics of neural cryptography

International Nuclear Information System (INIS)

Ruttor, Andreas; Kinzel, Wolfgang; Kanter, Ido

2007-01-01

Synchronization of neural networks has been used for public channel protocols in cryptography. In the case of tree parity machines the dynamics of both bidirectional synchronization and unidirectional learning is driven by attractive and repulsive stochastic forces. Thus it can be described well by a random walk model for the overlap between participating neural networks. For that purpose transition probabilities and scaling laws for the step sizes are derived analytically. Both these calculations as well as numerical simulations show that bidirectional interaction leads to full synchronization on average. In contrast, successful learning is only possible by means of fluctuations. Consequently, synchronization is much faster than learning, which is essential for the security of the neural key-exchange protocol. However, this qualitative difference between bidirectional and unidirectional interaction vanishes if tree parity machines with more than three hidden units are used, so that those neural networks are not suitable for neural cryptography. In addition, the effective number of keys which can be generated by the neural key-exchange protocol is calculated using the entropy of the weight distribution. As this quantity increases exponentially with the system size, brute-force attacks on neural cryptography can easily be made unfeasible

Dynamics of neural cryptography

Science.gov (United States)

Ruttor, Andreas; Kinzel, Wolfgang; Kanter, Ido

2007-05-01

Synchronization of neural networks has been used for public channel protocols in cryptography. In the case of tree parity machines the dynamics of both bidirectional synchronization and unidirectional learning is driven by attractive and repulsive stochastic forces. Thus it can be described well by a random walk model for the overlap between participating neural networks. For that purpose transition probabilities and scaling laws for the step sizes are derived analytically. Both these calculations as well as numerical simulations show that bidirectional interaction leads to full synchronization on average. In contrast, successful learning is only possible by means of fluctuations. Consequently, synchronization is much faster than learning, which is essential for the security of the neural key-exchange protocol. However, this qualitative difference between bidirectional and unidirectional interaction vanishes if tree parity machines with more than three hidden units are used, so that those neural networks are not suitable for neural cryptography. In addition, the effective number of keys which can be generated by the neural key-exchange protocol is calculated using the entropy of the weight distribution. As this quantity increases exponentially with the system size, brute-force attacks on neural cryptography can easily be made unfeasible.

Optimization Control of Bidirectional Cascaded DC-AC Converter Systems

DEFF Research Database (Denmark)

Tian, Yanjun

in bidirectional cascaded converter. This research work analyses the control strategies based on the topology of dual active bridges converter cascaded with a three phase inverter. It firstly proposed a dc link voltage and active power coordinative control method for this cascaded topology, and it can reduce dc....... The connections of the renewable energy sources to the power system are mostly through the power electronic converters. Moreover, for high controllability and flexibility, power electronic devices are gradually acting as the interface between different networks in power systems, promoting conventional power...... the bidirectional power flow in the distribution level of power systems. Therefore direct contact of converters introduces significant uncertainties to power system, especially for the stability and reliability. This dissertation studies the optimization control of the two stages directly connected converters...

Bidirectional selection between two classes in complex social networks.

Science.gov (United States)

Zhou, Bin; He, Zhe; Jiang, Luo-Luo; Wang, Nian-Xin; Wang, Bing-Hong

2014-12-19

The bidirectional selection between two classes widely emerges in various social lives, such as commercial trading and mate choosing. Until now, the discussions on bidirectional selection in structured human society are quite limited. We demonstrated theoretically that the rate of successfully matching is affected greatly by individuals' neighborhoods in social networks, regardless of the type of networks. Furthermore, it is found that the high average degree of networks contributes to increasing rates of successful matches. The matching performance in different types of networks has been quantitatively investigated, revealing that the small-world networks reinforces the matching rate more than scale-free networks at given average degree. In addition, our analysis is consistent with the modeling result, which provides the theoretical understanding of underlying mechanisms of matching in complex networks.

Engineering controllable bidirectional molecular motors based on myosin

Science.gov (United States)

Chen, Lu; Nakamura, Muneaki; Schindler, Tony D.; Parker, David; Bryant, Zev

2012-01-01

Cytoskeletal motors drive the transport of organelles and molecular cargoes within cells1, and have potential applications in molecular detection and diagnostic devices2,3. Engineering molecular motors with dynamically controllable properties will allow selective perturbation of mechanical processes in living cells, and yield optimized device components for complex tasks such as molecular sorting and directed assembly3. Biological motors have previously been modified by introducing activation/deactivation switches that respond to metal ions4,5 and other signals6. Here we show that myosin motors can be engineered to reversibly change their direction of motion in response to a calcium signal. Building on previous protein engineering studies7–11 and guided by a structural model12 for the redirected power stroke of myosin VI, we constructed bidirectional myosins through the rigid recombination of structural modules. The performance of the motors was confirmed using gliding filament assays and single fluorophore tracking. Our general strategy, in which external signals trigger changes in the geometry and mechanics of myosin lever arms, should enable spatiotemporal control over a range of motor properties including processivity, stride size13, and branchpoint turning14. PMID:22343382

Learning to Monitor Machine Health with Convolutional Bi-Directional LSTM Networks.

Science.gov (United States)

Zhao, Rui; Yan, Ruqiang; Wang, Jinjiang; Mao, Kezhi

2017-01-30

In modern manufacturing systems and industries, more and more research efforts have been made in developing effective machine health monitoring systems. Among various machine health monitoring approaches, data-driven methods are gaining in popularity due to the development of advanced sensing and data analytic techniques. However, considering the noise, varying length and irregular sampling behind sensory data, this kind of sequential data cannot be fed into classification and regression models directly. Therefore, previous work focuses on feature extraction/fusion methods requiring expensive human labor and high quality expert knowledge. With the development of deep learning methods in the last few years, which redefine representation learning from raw data, a deep neural network structure named Convolutional Bi-directional Long Short-Term Memory networks (CBLSTM) has been designed here to address raw sensory data. CBLSTM firstly uses CNN to extract local features that are robust and informative from the sequential input. Then, bi-directional LSTM is introduced to encode temporal information. Long Short-Term Memory networks(LSTMs) are able to capture long-term dependencies and model sequential data, and the bi-directional structure enables the capture of past and future contexts. Stacked, fully-connected layers and the linear regression layer are built on top of bi-directional LSTMs to predict the target value. Here, a real-life tool wear test is introduced, and our proposed CBLSTM is able to predict the actual tool wear based on raw sensory data. The experimental results have shown that our model is able to outperform several state-of-the-art baseline methods.

Learning to Monitor Machine Health with Convolutional Bi-Directional LSTM Networks

Directory of Open Access Journals (Sweden)

Rui Zhao

2017-01-01

Full Text Available In modern manufacturing systems and industries, more and more research efforts have been made in developing effective machine health monitoring systems. Among various machine health monitoring approaches, data-driven methods are gaining in popularity due to the development of advanced sensing and data analytic techniques. However, considering the noise, varying length and irregular sampling behind sensory data, this kind of sequential data cannot be fed into classification and regression models directly. Therefore, previous work focuses on feature extraction/fusion methods requiring expensive human labor and high quality expert knowledge. With the development of deep learning methods in the last few years, which redefine representation learning from raw data, a deep neural network structure named Convolutional Bi-directional Long Short-Term Memory networks (CBLSTM has been designed here to address raw sensory data. CBLSTM firstly uses CNN to extract local features that are robust and informative from the sequential input. Then, bi-directional LSTM is introduced to encode temporal information. Long Short-Term Memory networks(LSTMs are able to capture long-term dependencies and model sequential data, and the bi-directional structure enables the capture of past and future contexts. Stacked, fully-connected layers and the linear regression layer are built on top of bi-directional LSTMs to predict the target value. Here, a real-life tool wear test is introduced, and our proposed CBLSTM is able to predict the actual tool wear based on raw sensory data. The experimental results have shown that our model is able to outperform several state-of-the-art baseline methods.

Intrinsic functional brain mapping in reconstructed 4D magnetic susceptibility (χ) data space.

Science.gov (United States)

Chen, Zikuan; Calhoun, Vince

2015-02-15

By solving an inverse problem of T2*-weighted magnetic resonance imaging for a dynamic fMRI study, we reconstruct a 4D magnetic susceptibility source (χ) data space for intrinsic functional mapping. A 4D phase dataset is calculated from a 4D complex fMRI dataset. The background field and phase wrapping effect are removed by a Laplacian technique. A 3D χ source map is reconstructed from a 3D phase image by a computed inverse MRI (CIMRI) scheme. A 4D χ data space is reconstructed by repeating the 3D χ source reconstruction for each time point. A functional map is calculated by a temporal correlation between voxel signals in the 4D χ space and the timecourse of the task paradigm. With a finger-tapping experiment, we obtain two 3D functional mappings in the 4D magnitude data space and in the reconstructed 4D χ data space. We find that the χ-based functional mapping reveals co-occurrence of bidirectional responses in a 3D activation map that is different from the conventional magnitude-based mapping. The χ-based functional mapping can also be achieved by a 3D deconvolution of a phase activation map. Based on a subject experimental comparison, we show that the 4D χ tomography method could produce a similar χ activation map as obtained by the 3D deconvolution method. By removing the dipole effect and other fMRI technological contaminations, 4D χ tomography provides a 4D χ data space that allows a more direct and truthful functional mapping of a brain activity. Published by Elsevier B.V.

Encoding Strategy for Maximum Noise Tolerance Bidirectional Associative Memory

National Research Council Canada - National Science Library

Shen, Dan

2003-01-01

In this paper, the Basic Bidirectional Associative Memory (BAM) is extended by choosing weights in the correlation matrix, for a given set of training pairs, which result in a maximum noise tolerance set for BAM...

Aimed manipulation of fluxon dynamics in stacks of intrinsic Josephson-junctions out of Bi2Sr2CaCu2O8+x

International Nuclear Information System (INIS)

Oehmichen, V.

2007-01-01

Goal of this thesis was to extend the knowledge of fluxon dynamics in intrinsic Josephson junctions out of BSCCO and to manipulate this dynamics in a purposeful way. New approaches to create ThZ-radiation were investigated. Step stacks out of BSCCO have been prepared with dimensions of 1-3 μm (width) and 3-10 μm (length). The necessary fabrication process was established based on Wang's double-sided technique. Transport measurements without and with magnetic field were realised on the so produced samples. The magnetic field of some Tesla was oriented parallel to the CuO 2 -double layers. Collective plasma resonances were observed. Those were more stable than the resonances in mesa-structures. The resonances in the low current range can be assigned to an out-of-phase configuration, whereas in the high current range there are some possible configurations. Flux-flow-oscillations measured at these step stacks support the arrangement of the fluxons in an out-of-phase configuration. The in-phase configuration couldn't be observed clearly, so two approaches were followed to manipulate aimingly the fluxon dynamics to create THz-radiation: * control current * geometric manipulation: width-modulated stack For electronic manipulation an additional current line (control current line) was prepared along the stack's bottom. During transport measurements in zero field a current of 0-30 μA was sent through this control current line. The so created inhomogeneity should have provoked fluxons without the help of a magnetic field. A visible effect couldn't be measured. Geometric manipulation of fluxon dynamics to reach in-phase configuration relys on modulation of the stack's width: it has periodic necks (comb structure). First measurements on comb structures prepared in double-side technique show promising hints, that manipulation on purpose of fluxon dynamics is possible using width-modulation. Simulations were performed for different depths of modulation, small and large stacks

Ethnic Stigma, Academic Anxiety, and Intrinsic Motivation in Middle Childhood

Science.gov (United States)

Gillen-O'Neel, Cari; Ruble, Diane N.; Fuligni, Andrew J.

2011-01-01

Previous research addressing the dynamics of stigma and academics has focused on African American adolescents and adults. The present study examined stigma awareness, academic anxiety, and intrinsic motivation among 451 young (ages 6-11) and diverse (African American, Chinese, Dominican, Russian, and European American) students. Results indicated…

Stationary oscillation for nonautonomous bidirectional associative memory neural networks with impulse

International Nuclear Information System (INIS)

Zhang Yinping

2009-01-01

In this paper, we study the existence, uniqueness and global stability of periodic solution (i.e. stationary oscillation) for general bidirectional associative memory neural networks with impulses. Some sufficient conditions are obtained for stationary oscillation of the nonautonomous bidirectional associative memory neural networks with impulses. It is derived by using a new method which is different from those of previous literatures, and a assumption in previous results does not required. The model considered is more general and some previous results are extended and improved. An illustrative example is given to demonstrate the effectiveness and less conservativeness of the obtained results.

Colours sometimes count: awareness and bidirectionality in grapheme-colour synaesthesia.

Science.gov (United States)

Johnson, Addie; Jepma, Marieke; de Jong, Ritske

2007-10-01

Three experiments were conducted with 10 grapheme-colour synaesthetes and 10 matched controls to investigate (a) whether awareness of the inducer grapheme is necessary for synaesthetic colour induction and (b) whether grapheme-colour synaesthesia may be bidirectional in the sense that not only do graphemes induce colours, but that colours influence the processing of graphemes. Using attentional blink and Stroop paradigms with digit targets, we found that some synaesthetes did report "seeing" synaesthetic colours even when they were not able to report the inducing digit. Moreover, congruency effects (effects of matching the colour of digit presentation with the synaesthetic colour associated with that digit) suggested that grapheme-colour synaesthesia can be bidirectional, at least for some synaesthetes.

Bidirectional dc-to-dc Power Converter

Science.gov (United States)

Griesbach, C. R.

1986-01-01

Solid-state, series-resonant converter uses high-voltage thyristors. Converter used either to convert high-voltage, low-current dc power to lowvoltage, high current power or reverse. Taking advantage of newly-available high-voltage thyristors to provide better reliability and efficiency than traditional converters that use vacuum tubes as power switches. New converter essentially maintenance free and provides greatly increased mean time between failures. Attractive in industrial applications whether or not bidirectional capability is required.

Empirical intrinsic geometry for nonlinear modeling and time series filtering.

Science.gov (United States)

Talmon, Ronen; Coifman, Ronald R

2013-07-30

In this paper, we present a method for time series analysis based on empirical intrinsic geometry (EIG). EIG enables one to reveal the low-dimensional parametric manifold as well as to infer the underlying dynamics of high-dimensional time series. By incorporating concepts of information geometry, this method extends existing geometric analysis tools to support stochastic settings and parametrizes the geometry of empirical distributions. However, the statistical models are not required as priors; hence, EIG may be applied to a wide range of real signals without existing definitive models. We show that the inferred model is noise-resilient and invariant under different observation and instrumental modalities. In addition, we show that it can be extended efficiently to newly acquired measurements in a sequential manner. These two advantages enable us to revisit the Bayesian approach and incorporate empirical dynamics and intrinsic geometry into a nonlinear filtering framework. We show applications to nonlinear and non-Gaussian tracking problems as well as to acoustic signal localization.

Exact complexity: The spectral decomposition of intrinsic computation

International Nuclear Information System (INIS)

Crutchfield, James P.; Ellison, Christopher J.; Riechers, Paul M.

2016-01-01

We give exact formulae for a wide family of complexity measures that capture the organization of hidden nonlinear processes. The spectral decomposition of operator-valued functions leads to closed-form expressions involving the full eigenvalue spectrum of the mixed-state presentation of a process's ϵ-machine causal-state dynamic. Measures include correlation functions, power spectra, past-future mutual information, transient and synchronization informations, and many others. As a result, a direct and complete analysis of intrinsic computation is now available for the temporal organization of finitary hidden Markov models and nonlinear dynamical systems with generating partitions and for the spatial organization in one-dimensional systems, including spin systems, cellular automata, and complex materials via chaotic crystallography. - Highlights: • We provide exact, closed-form expressions for a hidden stationary process' intrinsic computation. • These include information measures such as the excess entropy, transient information, and synchronization information and the entropy-rate finite-length approximations. • The method uses an epsilon-machine's mixed-state presentation. • The spectral decomposition of the mixed-state presentation relies on the recent development of meromorphic functional calculus for nondiagonalizable operators.

Intrinsic Noise Profoundly Alters the Dynamics and Steady State of Morphogen-Controlled Bistable Genetic Switches.

Directory of Open Access Journals (Sweden)

Ruben Perez-Carrasco

2016-10-01

Full Text Available During tissue development, patterns of gene expression determine the spatial arrangement of cell types. In many cases, gradients of secreted signalling molecules-morphogens-guide this process by controlling downstream transcriptional networks. A mechanism commonly used in these networks to convert the continuous information provided by the gradient into discrete transitions between adjacent cell types is the genetic toggle switch, composed of cross-repressing transcriptional determinants. Previous analyses have emphasised the steady state output of these mechanisms. Here, we explore the dynamics of the toggle switch and use exact numerical simulations of the kinetic reactions, the corresponding Chemical Langevin Equation, and Minimum Action Path theory to establish a framework for studying the effect of gene expression noise on patterning time and boundary position. This provides insight into the time scale, gene expression trajectories and directionality of stochastic switching events between cell states. Taking gene expression noise into account predicts that the final boundary position of a morphogen-induced toggle switch, although robust to changes in the details of the noise, is distinct from that of the deterministic system. Moreover, the dramatic increase in patterning time close to the boundary predicted from the deterministic case is substantially reduced. The resulting stochastic switching introduces differences in patterning time along the morphogen gradient that result in a patterning wave propagating away from the morphogen source with a velocity determined by the intrinsic noise. The wave sharpens and slows as it advances and may never reach steady state in a biologically relevant time. This could explain experimentally observed dynamics of pattern formation. Together the analysis reveals the importance of dynamical transients for understanding morphogen-driven transcriptional networks and indicates that gene expression noise can

Intrinsic Noise Profoundly Alters the Dynamics and Steady State of Morphogen-Controlled Bistable Genetic Switches

Science.gov (United States)

Page, Karen M.

2016-01-01

During tissue development, patterns of gene expression determine the spatial arrangement of cell types. In many cases, gradients of secreted signalling molecules—morphogens—guide this process by controlling downstream transcriptional networks. A mechanism commonly used in these networks to convert the continuous information provided by the gradient into discrete transitions between adjacent cell types is the genetic toggle switch, composed of cross-repressing transcriptional determinants. Previous analyses have emphasised the steady state output of these mechanisms. Here, we explore the dynamics of the toggle switch and use exact numerical simulations of the kinetic reactions, the corresponding Chemical Langevin Equation, and Minimum Action Path theory to establish a framework for studying the effect of gene expression noise on patterning time and boundary position. This provides insight into the time scale, gene expression trajectories and directionality of stochastic switching events between cell states. Taking gene expression noise into account predicts that the final boundary position of a morphogen-induced toggle switch, although robust to changes in the details of the noise, is distinct from that of the deterministic system. Moreover, the dramatic increase in patterning time close to the boundary predicted from the deterministic case is substantially reduced. The resulting stochastic switching introduces differences in patterning time along the morphogen gradient that result in a patterning wave propagating away from the morphogen source with a velocity determined by the intrinsic noise. The wave sharpens and slows as it advances and may never reach steady state in a biologically relevant time. This could explain experimentally observed dynamics of pattern formation. Together the analysis reveals the importance of dynamical transients for understanding morphogen-driven transcriptional networks and indicates that gene expression noise can qualitatively

Quantum synchronization effects in intrinsic Josephson junctions

International Nuclear Information System (INIS)

Machida, M.; Kano, T.; Yamada, S.; Okumura, M.; Imamura, T.; Koyama, T.

2008-01-01

We investigate quantum dynamics of the superconducting phase in intrinsic Josephson junctions of layered high-T c superconductors motivated by a recent experimental observation for the switching rate enhancement in the low temperature quantum regime. We pay attention to only the capacitive coupling between neighboring junctions and perform large-scale simulations for the Schroedinger equation derived from the Hamiltonian considering the capacitive coupling alone. The simulation focuses on an issue whether the switching of a junction induces those of the other junctions or not. The results reveal that the superconducting phase dynamics show synchronous behavior with increasing the quantum character, e.g., decreasing the junction plane area and effectively the temperature. This is qualitatively consistent with the experimental result

Linearly and nonlinearly bidirectionally coupled synchronization of hyperchaotic systems

International Nuclear Information System (INIS)

Zhou Jin; Lu Junan; Wu Xiaoqun

2007-01-01

To date, there have been many results about unidirectionally coupled synchronization of chaotic systems. However, much less work is reported on bidirectionally-coupled synchronization. In this paper, we investigate the synchronization of two bidirectionally coupled Chen hyperchaotic systems, which are coupled linearly and nonlinearly respectively. Firstly, linearly coupled synchronization of two hyperchaotic Chen systems is investigated, and a theorem on how to choose the coupling coefficients are developed to guarantee the global asymptotical synchronization of two coupled hyperchaotic systems. Analysis shows that the choice of the coupling coefficients relies on the bound of the chaotic system. Secondly, the nonlinearly coupled synchronization is studied; a sufficient condition for the locally asymptotical synchronization is derived, which is independent of the bound of the hyperchaotic system. Finally, numerical simulations are included to verify the effectiveness and feasibility of the developed theorems

A deterministic mathematical model for bidirectional excluded flow with Langmuir kinetics.

Science.gov (United States)

Zarai, Yoram; Margaliot, Michael; Tuller, Tamir

2017-01-01

In many important cellular processes, including mRNA translation, gene transcription, phosphotransfer, and intracellular transport, biological "particles" move along some kind of "tracks". The motion of these particles can be modeled as a one-dimensional movement along an ordered sequence of sites. The biological particles (e.g., ribosomes or RNAPs) have volume and cannot surpass one another. In some cases, there is a preferred direction of movement along the track, but in general the movement may be bidirectional, and furthermore the particles may attach or detach from various regions along the tracks. We derive a new deterministic mathematical model for such transport phenomena that may be interpreted as a dynamic mean-field approximation of an important model from mechanical statistics called the asymmetric simple exclusion process (ASEP) with Langmuir kinetics. Using tools from the theory of monotone dynamical systems and contraction theory we show that the model admits a unique steady-state, and that every solution converges to this steady-state. Furthermore, we show that the model entrains (or phase locks) to periodic excitations in any of its forward, backward, attachment, or detachment rates. We demonstrate an application of this phenomenological transport model for analyzing ribosome drop off in mRNA translation.

Dynamic viscosity of polymer solutions

Energy Technology Data Exchange (ETDEWEB)

Peterlin, A

1982-03-01

The dynamic viscosity investigation of solutions of long chain polymers in very viscous solvents has definitely shown the existence of the low and high frequency plateau with the gradual transition between them. In both extreme cases the extrapolation of the measured Newtonian viscosities of the plateaus to the infinite dilution yields the limiting intrinsic viscosities. Such a behavior is expected from the dynamic intrinsic viscosity of the necklace model of the linear polymer with finite internal viscosity. The plateau at low frequency shows up in any model of polymer solution. This work shows the constant dynamic intrinsic viscosity in both extreme cases is well reproducible by the necklace model with the internal viscosity acting only between the beads on the same link. 20 references.

Compiling a Bidirectional Dictionary Bridging English and the Sotho ...

African Journals Online (AJOL)

rbr

bi-directional Sesotho sa Leboa ↔ Sesotho, Sesotho sa Leboa ↔ Setswana and ... example, the 100 most frequently used words in Sesotho sa Leboa in ranking .... Consider in this regard a selection of such mutual lexical items with high.

10 Gb/s bidirectional single fibre long reach PON link with distributed Raman amplification

DEFF Research Database (Denmark)

Tafur Monroy, Idelfonso; Kjær, Rasmus; Jeppesen, Palle

2006-01-01

We report operation of a single fibre bidirectional 80 km long reach PON link with symmetric up- and-downstream data rate of 10 Gb/s supported by distributed Raman fibre amplification only.......We report operation of a single fibre bidirectional 80 km long reach PON link with symmetric up- and-downstream data rate of 10 Gb/s supported by distributed Raman fibre amplification only....

Günther Tulip inferior vena cava filter retrieval using a bidirectional loop-snare technique.

Science.gov (United States)

Ross, Jordan; Allison, Stephen; Vaidya, Sandeep; Monroe, Eric

2016-01-01

Many advanced techniques have been reported in the literature for difficult Günther Tulip filter removal. This report describes a bidirectional loop-snare technique in the setting of a fibrin scar formation around the filter leg anchors. The bidirectional loop-snare technique allows for maximal axial tension and alignment for stripping fibrin scar from the filter legs, a commonly encountered complication of prolonged dwell times.

Strong intrinsic motivation

OpenAIRE

Dessi, Roberta; Rustichini, Aldo

2015-01-01

A large literature in psychology, and more recently in economics, has argued that monetary rewards can reduce intrinsic motivation. We investigate whether the negative impact persists when intrinsic motivation is strong, and test this hypothesis experimentally focusing on the motivation to undertake interesting and challenging tasks, informative about individual ability. We find that this type of task can generate strong intrinsic motivation, that is impervious to the effect of monetary incen...

Extrinsic relative to intrinsic goal pursuits and peer dynamics: selection and influence processes among adolescents.

Science.gov (United States)

Duriez, Bart; Giletta, Matteo; Kuppens, Peter; Vansteenkiste, Maarten

2013-10-01

Self-Determination Theory discerns goals and values in terms of whether they are intrinsic or extrinsic in nature. Although research substantiates the importance of goal preferences for a host of outcomes, few studies examined how such preferences develop, and studies that did pay attention to this focused on parental influence processes. The present study focuses on the role of peers. Social network analyses on longitudinal data gathered among senior high-school students (N = 695) confirm that peer similarity in goal pursuit exists, and that, although this similarity partly originates from adolescents selecting friends on the basis of perceived goal pursuit similarity, it also results from peers actively influencing each other. Hence, friends tend to become more alike in terms of goal pursuit over time. Data also suggest that, although changes in goal pursuit at this age can be predicted from peer dynamics, they cannot be attributed to parental goal promotion efforts. Copyright © 2013 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Use of asymmetric bidirectional catheters with different curvature radius for catheter ablation of cardiac arrhythmias.

Science.gov (United States)

Mantziari, Lilian; Suman-Horduna, Irina; Gujic, Marko; Jones, David G; Wong, Tom; Markides, Vias; Foran, John P; Ernst, Sabine

2013-06-01

The impact of recently introduced asymmetric bidirectional ablation catheters on procedural parameters and acute success rates of ablation procedures is unknown. We retrospectively analyzed data regarding ablations using a novel bidirectional catheter in a tertiary cardiac center and compared these in 1:5 ratio with a control group of procedures matched for age, gender, operator, and ablation type. A total of 50 cases and 250 controls of median age 60 (50-68) years were studied. Structural heart disease was equally prevalent in both groups (39%) while history of previous ablations was more common in the study arm (54% vs 30%, P = 0.001). Most of the ablation cases were for atrial fibrillation (46%), followed by atrial tachycardia (28%), supraventricular tachycardia (12%), and ventricular tachycardia (14%). Median procedure duration was 128 (52-147) minutes with the bidirectional, versus 143 (105-200) minutes with the conventional catheter (P = 0.232), and median fluoroscopy time was 17 (10-34) minutes versus 23 (12-39) minutes, respectively (P = 0.988). There was a trend toward a lower procedure duration for the atrial tachycardia ablations, 89 (52-147) minutes versus 130 (100-210) minutes, P = 0.064. The procedure was successfully completed in 96% of the bidirectional versus 84% of the control cases (P = 0.151). A negative correlation was observed between the relative fluoroscopy duration and the case number (r = -0.312, P = 0.028), reflecting the learning curve for the bidirectional catheter. The introduction of the bidirectional catheter resulted in no prolongation of procedure parameters and similar success rates, while there was a trend toward a lower procedure duration for atrial tachycardia ablations. ©2013, The Authors. Journal compilation ©2013 Wiley Periodicals, Inc.

Symplectic Structure of Intrinsic Time Gravity

Directory of Open Access Journals (Sweden)

Eyo Eyo Ita

2016-08-01

Full Text Available The Poisson structure of intrinsic time gravity is analysed. With the starting point comprising a unimodular three-metric with traceless momentum, a trace-induced anomaly results upon quantization. This leads to a revision of the choice of momentum variable to the (mixed index traceless momentric. This latter choice unitarily implements the fundamental commutation relations, which now take on the form of an affine algebra with SU(3 Lie algebra amongst the momentric variables. The resulting relations unitarily implement tracelessness upon quantization. The associated Poisson brackets and Hamiltonian dynamics are studied.

State-Dependent Decoding Algorithms Improve the Performance of a Bidirectional BMI in Anesthetized Rats

Directory of Open Access Journals (Sweden)

Vito De Feo

2017-05-01

Full Text Available Brain-machine interfaces (BMIs promise to improve the quality of life of patients suffering from sensory and motor disabilities by creating a direct communication channel between the brain and the external world. Yet, their performance is currently limited by the relatively small amount of information that can be decoded from neural activity recorded form the brain. We have recently proposed that such decoding performance may be improved when using state-dependent decoding algorithms that predict and discount the large component of the trial-to-trial variability of neural activity which is due to the dependence of neural responses on the network's current internal state. Here we tested this idea by using a bidirectional BMI to investigate the gain in performance arising from using a state-dependent decoding algorithm. This BMI, implemented in anesthetized rats, controlled the movement of a dynamical system using neural activity decoded from motor cortex and fed back to the brain the dynamical system's position by electrically microstimulating somatosensory cortex. We found that using state-dependent algorithms that tracked the dynamics of ongoing activity led to an increase in the amount of information extracted form neural activity by 22%, with a consequently increase in all of the indices measuring the BMI's performance in controlling the dynamical system. This suggests that state-dependent decoding algorithms may be used to enhance BMIs at moderate computational cost.

State-Dependent Decoding Algorithms Improve the Performance of a Bidirectional BMI in Anesthetized Rats.

Science.gov (United States)

De Feo, Vito; Boi, Fabio; Safaai, Houman; Onken, Arno; Panzeri, Stefano; Vato, Alessandro

2017-01-01

Brain-machine interfaces (BMIs) promise to improve the quality of life of patients suffering from sensory and motor disabilities by creating a direct communication channel between the brain and the external world. Yet, their performance is currently limited by the relatively small amount of information that can be decoded from neural activity recorded form the brain. We have recently proposed that such decoding performance may be improved when using state-dependent decoding algorithms that predict and discount the large component of the trial-to-trial variability of neural activity which is due to the dependence of neural responses on the network's current internal state. Here we tested this idea by using a bidirectional BMI to investigate the gain in performance arising from using a state-dependent decoding algorithm. This BMI, implemented in anesthetized rats, controlled the movement of a dynamical system using neural activity decoded from motor cortex and fed back to the brain the dynamical system's position by electrically microstimulating somatosensory cortex. We found that using state-dependent algorithms that tracked the dynamics of ongoing activity led to an increase in the amount of information extracted form neural activity by 22%, with a consequently increase in all of the indices measuring the BMI's performance in controlling the dynamical system. This suggests that state-dependent decoding algorithms may be used to enhance BMIs at moderate computational cost.

Intrinsic Motivation.

Science.gov (United States)

Deci, Edward L.

The paper draws together a wide variety of research which relates to the topic of intrinsic motivation; intrinsically motivated activities are defined as those which a person does for no apparent reward except the activity itself or the feelings which result from the activity. Most of this research was not originally reported within the framework…

Generalized Synchronization in AN Array of Nonlinear Dynamic Systems with Applications to Chaotic Cnn

Science.gov (United States)

Min, Lequan; Chen, Guanrong

This paper establishes some generalized synchronization (GS) theorems for a coupled discrete array of difference systems (CDADS) and a coupled continuous array of differential systems (CCADS). These constructive theorems provide general representations of GS in CDADS and CCADS. Based on these theorems, one can design GS-driven CDADS and CCADS via appropriate (invertible) transformations. As applications, the results are applied to autonomous and nonautonomous coupled Chen cellular neural network (CNN) CDADS and CCADS, discrete bidirectional Lorenz CNN CDADS, nonautonomous bidirectional Chua CNN CCADS, and nonautonomously bidirectional Chen CNN CDADS and CCADS, respectively. Extensive numerical simulations show their complex dynamic behaviors. These theorems provide new means for understanding the GS phenomena of complex discrete and continuously differentiable networks.

Parenting and Children's Externalizing Behavior: Bidirectionality during Toddlerhood

Science.gov (United States)

Verhoeven, Marjolein; Junger, Marianne; van Aken, Chantal; Dekovic, Maja; van Aken, Marcel A. G.

2010-01-01

This study examined the bidirectional relationship between parenting and boys' externalizing behaviors in a four-wave longitudinal study of toddlers. Participants were 104 intact two-parent families with toddler sons. When their sons were 17, 23, 29, and 35 months of age, mothers and fathers reported on a broad range of parenting dimensions…

Intrinsic contractures of the hand.

Science.gov (United States)

Paksima, Nader; Besh, Basil R

2012-02-01

Contractures of the intrinsic muscles of the fingers disrupt the delicate and complex balance of intrinsic and extrinsic muscles, which allows the hand to be so versatile and functional. The loss of muscle function primarily affects the interphalangeal joints but also may affect etacarpophalangeal joints. The resulting clinical picture is often termed, intrinsic contracture or intrinsic-plus hand. Disruption of the balance between intrinsic and extrinsic muscles has many causes and may be secondary to changes within the intrinsic musculature or the tendon unit. This article reviews diagnosis, etiology, and treatment algorithms in the management of intrinsic contractures of the fingers. Copyright © 2012 Elsevier Inc. All rights reserved.

Bifurcation Analysis of a DC-DC Bidirectional Power Converter Operating with Constant Power Loads

Science.gov (United States)

Cristiano, Rony; Pagano, Daniel J.; Benadero, Luis; Ponce, Enrique

Direct current (DC) microgrids (MGs) are an emergent option to satisfy new demands for power quality and integration of renewable resources in electrical distribution systems. This work addresses the large-signal stability analysis of a DC-DC bidirectional converter (DBC) connected to a storage device in an islanding MG. This converter is responsible for controlling the balance of power (load demand and generation) under constant power loads (CPLs). In order to control the DC bus voltage through a DBC, we propose a robust sliding mode control (SMC) based on a washout filter. Dynamical systems techniques are exploited to assess the quality of this switching control strategy. In this sense, a bifurcation analysis is performed to study the nonlinear stability of a reduced model of this system. The appearance of different bifurcations when load parameters and control gains are changed is studied in detail. In the specific case of Teixeira Singularity (TS) bifurcation, some experimental results are provided, confirming the mathematical predictions. Both a deeper insight in the dynamic behavior of the controlled system and valuable design criteria are obtained.

Cellular Mechanisms Underlying Behavioral State-Dependent Bidirectional Modulation of Motor Cortex Output

Directory of Open Access Journals (Sweden)

Julia Schiemann

2015-05-01

Full Text Available Neuronal activity in primary motor cortex (M1 correlates with behavioral state, but the cellular mechanisms underpinning behavioral state-dependent modulation of M1 output remain largely unresolved. Here, we performed in vivo patch-clamp recordings from layer 5B (L5B pyramidal neurons in awake mice during quiet wakefulness and self-paced, voluntary movement. We show that L5B output neurons display bidirectional (i.e., enhanced or suppressed firing rate changes during movement, mediated via two opposing subthreshold mechanisms: (1 a global decrease in membrane potential variability that reduced L5B firing rates (L5Bsuppressed neurons, and (2 a coincident noradrenaline-mediated increase in excitatory drive to a subpopulation of L5B neurons (L5Benhanced neurons that elevated firing rates. Blocking noradrenergic receptors in forelimb M1 abolished the bidirectional modulation of M1 output during movement and selectively impaired contralateral forelimb motor coordination. Together, our results provide a mechanism for how noradrenergic neuromodulation and network-driven input changes bidirectionally modulate M1 output during motor behavior.

Bi-directional Reflectance of Icy Surface Analogs: A Dual Approach

Science.gov (United States)

Quinones, Juan Manuel; Vides, Christina; Nelson, Robert M.; Boryta, Mark; Mannat, Ken s.

2018-01-01

Bi-directional reflectance measurements of analogs for planetary regolith have provided insight into the surface properties of planetary satellites and small bodies. Because Aluminum Oxide (Al2O3) and water ice share a similar hexagonal crystalline structure, the former has been used in laboratory experiments to simulate the regolith of both icy and dusty planetary bodies. By measuring various sizes of well sorted size fractions of Al2O3, the reflectance phase curve and porosity of a planetary regolith can be determined. We have designed an experiment to test the laboratory measurements produced by Nelson et al. (2000). Additionally, we made reflectance measurements for other alkali-halide compounds that could be used for applications beyond astronomy and planetary science.In order to provide an independent check on the Nelson et al. data, we designed an instrument with a different configuration. While both instruments take bidirectional reflectance measurements, our instrument, the Rigid Photometric Goniometer (RPG), is fixed at a phase angle of 5° and detects the scattered light with a photomultiplier tube (PMT). The PMT current is then measured with an electrometer. Following the example of Nelson et al., we measured the bidirectional reflectance of Al2O3 particulate size fractions between 0.1sizes from 20size that provided optimal, or maximum, reflectance for each compound. Our conclusions bring confirmation and clarity to photometric sciences.

Performance Analysis of Video PHY Controller Using Unidirection and Bi-directional IO Standard via 7 Series FPGA

DEFF Research Database (Denmark)

Das, Bhagwan; Abdullah, M F L; Hussain, Dil muhammed Akbar

2017-01-01

graphics consumes more power, this creates a need of designing the low power design for Video PHY controller. In this paper, the performance of Video PHY controller is analyzed by comparing the power consumption of unidirectional and bi-directional IO Standard over 7 series FPGA. It is determined...... that total on-chip power is reduced for unidirectional IO Standard based Video PHY controller compared to bidirectional IO Standard based Video PHY controller. The most significant achievement of this work is that it is concluded that unidirectional IO Standard based Video PHY controller consume least...... standby power compared to bidirectional IO Standard based Video PHY controller. It is defined that for 6 GHz operated frequency Video PHY controller, the 32% total on-chip power is reduced using unidirectional IO Standard based Video PHY controller is less compared to bidirectional IO Standard based Video...

Bidirectional Barbed Sutures for Wound Closure: Evolution and Applications

Science.gov (United States)

Paul, Malcolm D.

2009-01-01

Traditionally, wound closure sutures have in common the need to tie knots with the inherent risk of extrusion, palpability, microinfarcts, breakage, and slippage. Bidirectional barbed sutures have barbs arrayed in a helical fashion in opposing directions on either side of an unbarbed midsegment. This suture is inserted at the midpoint of a wound and pulled through till resistance is encountered from the opposing barbs; each half of the suture is then advanced to the lateral ends of the wound. This design provides a method of evenly distributing tension along the incision line, a faster suture placement and closure time with no need to tie knots, and the possibility of improved cosmesis. Bidirectional barbed sutures, which are available in both absorbable and nonabsorbable forms, can be used for simple closures, multilayered closures, and closure of high-tension wounds in a variety of surgical settings. PMID:24527114

Bidirectional fiber-wireless and fiber-VLLC transmission system based on an OEO-based BLS and a RSOA.

Science.gov (United States)

Lu, Hai-Han; Li, Chung-Yi; Lu, Ting-Chien; Wu, Chang-Jen; Chu, Chien-An; Shiva, Ajay; Mochii, Takao

2016-02-01

A bidirectional fiber-wireless and fiber-visible-laser-light-communication (VLLC) transmission system based on an optoelectronic oscillator (OEO)-based broadband light source (BLS) and a reflective semiconductor optical amplifier (RSOA) is proposed and experimentally demonstrated. Through an in-depth observation of such bidirectional fiber-wireless and fiber-VLLC transmission systems, good bit error rate performances are obtained over a 40 km single-mode fiber and a 10 m RF/optical wireless transport. Such a bidirectional fiber-wireless and fiber-VLLC transmission system is an attractive option for providing broadband integrated services.

Combating Weapons of Mass Destruction: Models, Complexity, and Algorithms in Complex Dynamic and Evolving Networks

Science.gov (United States)

2015-11-01

Gholamreza, and Ester, Martin. “Modeling the Temporal Dynamics of Social Rating Networks Using Bidirectional Effects of Social Relations and Rating...1.1.2 β-disruptor Problems Besides the homogeneous network model consisting of uniform nodes and bidirectional links, the heterogeneous network model... neural and metabolic networks .” Biological Cybernetics 90 (2004): 311–317. 10.1007/s00422-004-0479-1. URL http://dx.doi.org/10.1007/s00422-004-0479-1 [51

Intrinsic and extrinsic mortality reunited

DEFF Research Database (Denmark)

Koopman, Jacob J E; Wensink, Maarten J; Rozing, Maarten P

2015-01-01

Intrinsic and extrinsic mortality are often separated in order to understand and measure aging. Intrinsic mortality is assumed to be a result of aging and to increase over age, whereas extrinsic mortality is assumed to be a result of environmental hazards and be constant over age. However......, allegedly intrinsic and extrinsic mortality have an exponentially increasing age pattern in common. Theories of aging assert that a combination of intrinsic and extrinsic stressors underlies the increasing risk of death. Epidemiological and biological data support that the control of intrinsic as well...... as extrinsic stressors can alleviate the aging process. We argue that aging and death can be better explained by the interaction of intrinsic and extrinsic stressors than by classifying mortality itself as being either intrinsic or extrinsic. Recognition of the tight interaction between intrinsic and extrinsic...

Primary Parallel Isolated Boost Converter with Bidirectional Operation

DEFF Research Database (Denmark)

Hernandez Botella, Juan Carlos; Mira Albert, Maria del Carmen; Sen, Gökhan

2012-01-01

This paper presents a bidirectional dc/dc converter operated with batteries both in the input and output. Primary parallel isolated boost converter (PPIBC) with transformer series connection on the high voltage side is preferred due to its ability to handle high currents in the low voltage side. ...... and output battery banks with a defined ramp....

Experimentally observed evolution between dynamic patterns and intrinsic localized modes in a driven nonlinear electrical cyclic lattice

Science.gov (United States)

Shige, S.; Miyasaka, K.; Shi, W.; Soga, Y.; Sato, M.; Sievers, A. J.

2018-02-01

Locked intrinsic localized modes (ILMs) and large amplitude lattice spatial modes (LSMs) have been experimentally measured for a driven 1-D nonlinear cyclic electric transmission line, where the nonlinear element is a saturable capacitor. Depending on the number of cells and electrical lattice damping an LSM of fixed shape can be tuned across the modal spectrum. Interestingly, by tuning the driver frequency away from this spectrum the LSM can be continuously converted into ILMs and vice versa. The differences in pattern formation between simulations and experimental findings are due to a low concentration of impurities. Through this novel nonlinear excitation and switching channel in cyclic lattices either energy balanced or unbalanced LSMs and ILMs may occur. Because of the general nature of these dynamical results for nonintegrable lattices applications are to be expected. The ultimate stability of driven aero machinery containing nonlinear periodic structures may be one example.

Bidirectional Relationships Between Parenting Processes and Deviance in a Sample of Inner-City African American Youth

Science.gov (United States)

Harris, Charlene; Vazsonyi, Alexander T.; Bolland, John M.

2016-01-01

The current study assessed for bidirectional relationships among supportive parenting (knowledge), negative parenting (permissiveness), and deviance in a sample (N = 5,325) of poor, inner-city African American youth from the Mobile Youth Survey (MYS) over 4 years. Cross-lagged path analysis provided evidence of significant bidirectional paths among parenting processes (knowledge and permissiveness) and deviance over time. Follow-up multigroup tests provided only modest evidence of dissimilar relationships by sex and by developmental periods. The findings improve our understanding of developmental changes between parenting behaviors and deviance during adolescence and extended current research of the bidirectionality of parent and child relationships among inner-city African American youth. PMID:28316460

Analysis of Bi-directional Effects on the Response of a Seismic Base Isolation System

International Nuclear Information System (INIS)

Park, Hyung-Kui; Kim, Jung-Han; Kim, Min Kyu; Choi, In-Kil

2014-01-01

The floor response spectrum depends on the height of the floor of the structure. Also FRS depends on the characteristics of the seismic base isolation system such as the natural frequency, damping ratio. In the previous study, the floor response spectrum of the base isolated structure was calculated for each axis without considering bi-directional effect. However, the shear behavior of the seismic base isolation system of two horizontal directions are correlated each other by the bi-directional effects. If the shear behavior of the seismic isolation system changes, it can influence the floor response spectrum and displacement response of isolators. In this study, the analysis of a bi-directional effect on the floor response spectrum was performed. In this study, the response of the seismic base isolation system based on the bi-directional effects was analyzed. By analyzing the time history result, while there is no alteration in the maximum shear force of seismic base isolation system, it is confirmed that the shear force is generally more decreased in a one-directional that in a two-directional in most parts. Due to the overall decreased shear force, the floor response spectrum is more reduced in a two-directional than in a one-directional

Correcting Bidirectional Effects in Remote Sensing Reflectance from Coastal Waters

Science.gov (United States)

Stamnes, K. H.; Fan, Y.; Li, W.; Voss, K. J.; Gatebe, C. K.

2016-02-01

Understanding bidirectional effects including sunglint is important for GEO-CAPE for several reasons: (i) correct interpretation of ocean color data; (ii) comparing consistency of spectral radiance data derived from space observations with a single instrument for a variety of illumination and viewing conditions; (iii) merging data collected by different instruments operating simultaneously. We present a new neural network (NN) method to correct bidirectional effects in water-leaving radiance for both Case 1 and Case 2 waters. We also discuss a new BRDF and 2D sun-glint model that was validated by comparing simulated surface reflectances with Cloud Absorption Radiometer (CAR) data. Finally, we present an extension of our marine bio-optical model to the UV range that accounts for the seasonal dependence of the inherent optical properties (IOPs).

A new setup to measure bidirectional reflectance distribution functions

NARCIS (Netherlands)

Roosjen, P.P.J.; Clevers, J.G.P.W.; Bartholomeus, H.

2012-01-01

The Plant Facility, a new laboratory goniometer system, built by the Wageningen University has been tested in order to take bidirectional reflectance distribution function (BRDF) measurements. An ASD FieldSpec 3 spectroradiometer mounted on an industrial robot arm is able to measure small targets

Optical properties (bidirectional reflectance distribution function) of shot fabric

NARCIS (Netherlands)

Lu, Rong; Koenderink, Jan J.; Kappers, Astrid M L

2000-01-01

To study the optical properties of materials, one needs a complete set of the angular distribution functions of surface scattering from the materials. Here we present a convenient method for collecting a large set of bidirectional reflectance distribution function (BRDF) samples in the hemispherical

Bidirectional current-voltage converters based on magnetostrictive/piezoelectric composites

NARCIS (Netherlands)

Jia, Y.; Or, S.W.; Chan, H.L.W.; Jiao, J.; Luo, H.; Van der Zwaag, S.

2009-01-01

We report a power supply-free, bidirectional electric current-voltage converter based on a coil-wound laminated composite of magnetostrictive alloy and piezoelectric crystal. An electric current applied to the coil induces a magnetic field, resulting in an electric voltage from the composite due to

Isolated Bidirectional DC–DC Converter for SuperCapacitor Applications

DEFF Research Database (Denmark)

Dehnavi, Sayed M. D.; Sen, Gökhan; Thomsen, Ole Cornelius

2011-01-01

This paper proposes a new bidirectional DC/DC converter for supercapacitor applications. The proposed converter has a parallel structure in supercapacitor side (where voltage is low and current is high) and a series structure in the other side. This structure increases efficiency of the converter...

Spin relaxation dynamics of holes in intrinsic GaAs quantum wells studied by transient circular dichromatic absorption spectroscopy at room temperature.

Science.gov (United States)

Fang, Shaoyin; Zhu, Ruidan; Lai, Tianshu

2017-03-21

Spin relaxation dynamics of holes in intrinsic GaAs quantum wells is studied using time-resolved circular dichromatic absorption spectroscopy at room temperature. It is found that ultrafast dynamics is dominated by the cooperative contributions of band filling and many-body effects. The relative contribution of the two effects is opposite in strength for electrons and holes. As a result, transient circular dichromatic differential transmission (TCD-DT) with co- and cross-circularly polarized pump and probe presents different strength at several picosecond delay time. Ultrafast spin relaxation dynamics of excited holes is sensitively reflected in TCD-DT with cross-circularly polarized pump and probe. A model, including coherent artifact, thermalization of nonthermal carriers and the cooperative contribution of band filling and many-body effects, is developed, and used to fit TCD-DT with cross-circularly polarized pump and probe. Spin relaxation time of holes is achieved as a function of excited hole density for the first time at room temperature, and increases with hole density, which disagrees with a theoretical prediction based on EY spin relaxation mechanism, implying that EY mechanism may be not dominant hole spin relaxation mechanism at room temperature, but DP mechanism is dominant possibly.

Deadbeat control of power leveling unit with bidirectional buck/boost DC/DC converter

OpenAIRE

Hamasaki, Shin-ichi; Mukai, Ryosuke; Yano, Yoshihiro; Tsuji, Mineo

2014-01-01

As a distributed generation system increases, a stable power supply becomes difficult. Thus control of power leveling (PL) unit is required to maintain the balance of power flow for irregular power generation. The unit is required to respond to change of voltage and bidirectional power flow. So the bidirectional buck/boost DC/DC converter is applied for the control of PL unit in this research. The PL unit with Electric double-layer capacitor (EDLC) is able to absorb change of power, and it is...

Finite-Time Stability for Fractional-Order Bidirectional Associative Memory Neural Networks with Time Delays

International Nuclear Information System (INIS)

Xu Chang-Jin; Li Pei-Luan; Pang Yi-Cheng

2017-01-01

This paper is concerned with fractional-order bidirectional associative memory (BAM) neural networks with time delays. Applying Laplace transform, the generalized Gronwall inequality and estimates of Mittag–Leffler functions, some sufficient conditions which ensure the finite-time stability of fractional-order bidirectional associative memory neural networks with time delays are obtained. Two examples with their simulations are given to illustrate the theoretical findings. Our results are new and complement previously known results. (paper)

Protein remote homology detection based on bidirectional long short-term memory.

Science.gov (United States)

Li, Shumin; Chen, Junjie; Liu, Bin

2017-10-10

Protein remote homology detection plays a vital role in studies of protein structures and functions. Almost all of the traditional machine leaning methods require fixed length features to represent the protein sequences. However, it is never an easy task to extract the discriminative features with limited knowledge of proteins. On the other hand, deep learning technique has demonstrated its advantage in automatically learning representations. It is worthwhile to explore the applications of deep learning techniques to the protein remote homology detection. In this study, we employ the Bidirectional Long Short-Term Memory (BLSTM) to learn effective features from pseudo proteins, also propose a predictor called ProDec-BLSTM: it includes input layer, bidirectional LSTM, time distributed dense layer and output layer. This neural network can automatically extract the discriminative features by using bidirectional LSTM and the time distributed dense layer. Experimental results on a widely-used benchmark dataset show that ProDec-BLSTM outperforms other related methods in terms of both the mean ROC and mean ROC50 scores. This promising result shows that ProDec-BLSTM is a useful tool for protein remote homology detection. Furthermore, the hidden patterns learnt by ProDec-BLSTM can be interpreted and visualized, and therefore, additional useful information can be obtained.

Intrinsic and extrinsic mortality reunited.

Science.gov (United States)

Koopman, Jacob J E; Wensink, Maarten J; Rozing, Maarten P; van Bodegom, David; Westendorp, Rudi G J

2015-07-01

Intrinsic and extrinsic mortality are often separated in order to understand and measure aging. Intrinsic mortality is assumed to be a result of aging and to increase over age, whereas extrinsic mortality is assumed to be a result of environmental hazards and be constant over age. However, allegedly intrinsic and extrinsic mortality have an exponentially increasing age pattern in common. Theories of aging assert that a combination of intrinsic and extrinsic stressors underlies the increasing risk of death. Epidemiological and biological data support that the control of intrinsic as well as extrinsic stressors can alleviate the aging process. We argue that aging and death can be better explained by the interaction of intrinsic and extrinsic stressors than by classifying mortality itself as being either intrinsic or extrinsic. Recognition of the tight interaction between intrinsic and extrinsic stressors in the causation of aging leads to the recognition that aging is not inevitable, but malleable through the environment. Copyright © 2015 Elsevier Inc. All rights reserved.

Effect of particle nonsphericity on bidirectional reflectance of cirrus clouds

Energy Technology Data Exchange (ETDEWEB)

Mishchenko, M.I.; Rossow, W.B.; Macke, A.; Lacis, A.A. [Goddard Institute for Space Studies, New York, NY (United States)

1996-04-01

This paper describes the use of the fractal ice particle method to study the differences in bidirectional reflectance caused by the differences in the single scattering phase functions of spherical water droplets and nonspherical ice crystals.

Longitudinal Bidirectional Relations between Adolescents' Sympathy and Prosocial Behavior

Science.gov (United States)

Carlo, Gustavo; Padilla-Walker, Laura M.; Nielson, Matthew G.

2015-01-01

Despite the importance of understanding sympathy and prosocial behaviors, research on the development of these tendencies in adolescence remains relatively sparse. In the present study, we examined age trends and bidirectional longitudinal relations in sympathy and prosocial behaviors across early to middle adolescents. Participants were 500…

A Bidirectional Relationship between Conceptual Organization and Word Learning

Directory of Open Access Journals (Sweden)

Tanya Kaefer

2013-01-01

Full Text Available This study explores the relationship between word learning and conceptual organization for preschool-aged children. We proposed a bidirectional model in which increases in word learning lead to increases in taxonomic organization, which, in turn, leads to further increases in word learning. In order to examine this model, we recruited 104 4-year olds from Head Start classrooms; 52 children participated in a two-week training program, and 52 children were in a control group. Results indicated that children in the training program learned more words and were more likely to sort taxonomically than children in the control condition. Furthermore, the number of words learned over the training period predicted the extent to which children categorized taxonomically. Additionally, this ability to categorize taxonomically predicted the number of words learned outside the training program, over and above the number of words learned in the program. These results suggest a bi-directional relationship between conceptual organization and word learning.

Dynamic pricing based on a cloud computing framework to support the integration of renewable energy sources

OpenAIRE

Rajeev Thankappan Nair; Ashok Sankar

2014-01-01

Integration of renewable energy sources into the electric grid in the domestic sector results in bidirectional energy flow from the supply side of the consumer to the grid. Traditional pricing methods are difficult to implement in such a situation of bidirectional energy flow and they face operational challenges on the application of price-based demand side management programme because of the intermittent characteristics of renewable energy sources. In this study, a dynamic pricing method usi...

Bidirectional magnetic microactuators for uTAS

Science.gov (United States)

Hilbich, Daniel D.; Khosla, Ajit; Gray, Bonnie L.; Shannon, Lesley

2011-02-01

We present the design, fabrication and characterization of a novel bidirectional magnetic microactuator. The actuator has a planar structure and is easily fabricated using processes based on laser micromachining and soft lithography, allowing it to be readily integrated into microfluidic, microelectromechanical systems (MEMS) and lab-on-a-chip (LOC) designs. The new microactuator is a thin magnetic membrane with a central magnet feature. The membrane and magnet are both composed of a magnetic nanocomposite polymer (M-NCP) material that is fabricated by embedding magnetic powder in a polydimethysiloxane (PDMS) polymer matrix. The magnetic powder (MQP-12-5) has the chemical composition of (Nd0.7Ce0.3)10.5Fe83.9B5.6, and contains grains that are 5-6 microns in size. The powder is uniformly dispersed at a weight percentage of 75 wt-% in the PDMS matrix, and micropatterned using soft lithography micromolding to realize magnetic microstructures, which sit on a thinner magnetic PDMS membrane of the same material. The molds are fabricated by laser-etching into Poly (methyl methacrylate) (PMMA) using a Universal Laser System's VersaLASERlaser ablation system. The PDMS-based M-NCP is then poured and spun over the mold patterns, producing a thin polymer membrane to which the polymer micromagnets are attached, forming a one-piece actuator. The M-NCP is initially un-magnetized, but is then magnetized by placing it in a 2.5T magnetic field to produce permanent bidirectional magnetization that is polarized in the specified direction. To characterize the bidirectional actuators, a uniform magnetic field is established via a Helmholtz coil pair, and is characterized by applying varying currents. The magnetic field (and thus the actuator deflection) is controlled by regulating the current in the Helmholtz pair. Using this apparatus, deflection versus field characteristics are obtained, with maximum deflections varying as a function of actuator dimensions and the applied magnetic

Quantifying the topography of the intrinsic energy landscape of flexible biomolecular recognition

Science.gov (United States)

Chu, Xiakun; Gan, Linfeng; Wang, Erkang; Wang, Jin

2013-01-01

Biomolecular functions are determined by their interactions with other molecules. Biomolecular recognition is often flexible and associated with large conformational changes involving both binding and folding. However, the global and physical understanding for the process is still challenging. Here, we quantified the intrinsic energy landscapes of flexible biomolecular recognition in terms of binding–folding dynamics for 15 homodimers by exploring the underlying density of states, using a structure-based model both with and without considering energetic roughness. By quantifying three individual effective intrinsic energy landscapes (one for interfacial binding, two for monomeric folding), the association mechanisms for flexible recognition of 15 homodimers can be classified into two-state cooperative “coupled binding–folding” and three-state noncooperative “folding prior to binding” scenarios. We found that the association mechanism of flexible biomolecular recognition relies on the interplay between the underlying effective intrinsic binding and folding energy landscapes. By quantifying the whole global intrinsic binding–folding energy landscapes, we found strong correlations between the landscape topography measure Λ (dimensionless ratio of energy gap versus roughness modulated by the configurational entropy) and the ratio of the thermodynamic stable temperature versus trapping temperature, as well as between Λ and binding kinetics. Therefore, the global energy landscape topography determines the binding–folding thermodynamics and kinetics, crucial for the feasibility and efficiency of realizing biomolecular function. We also found “U-shape” temperature-dependent kinetic behavior and a dynamical cross-over temperature for dividing exponential and nonexponential kinetics for two-state homodimers. Our study provides a unique way to bridge the gap between theory and experiments. PMID:23754431

Bidirectional effects between parenting and aggressive child behavior in the context of a preventive intervention

OpenAIRE

Brinke, L.W. te; Dekovic, M.; Stoltz, S.E.M.J.; Cillessen, A.H.N.

2017-01-01

Over time, developmental theories and empirical studies have gradually started to adopt a bidirectional viewpoint. The area of intervention research is, however, lagging behind in this respect. This longitudinal study examined whether bidirectional associations between (changes in) parenting and (changes in) aggressive child behavior over time differed in three conditions: a child intervention condition, a child + parent intervention condition and a control condition. Participants were 267 ch...

Intrinsic-density functionals

International Nuclear Information System (INIS)

Engel, J.

2007-01-01

The Hohenberg-Kohn theorem and Kohn-Sham procedure are extended to functionals of the localized intrinsic density of a self-bound system such as a nucleus. After defining the intrinsic-density functional, we modify the usual Kohn-Sham procedure slightly to evaluate the mean-field approximation to the functional, and carefully describe the construction of the leading corrections for a system of fermions in one dimension with a spin-degeneracy equal to the number of particles N. Despite the fact that the corrections are complicated and nonlocal, we are able to construct a local Skyrme-like intrinsic-density functional that, while different from the exact functional, shares with it a minimum value equal to the exact ground-state energy at the exact ground-state intrinsic density, to next-to-leading order in 1/N. We briefly discuss implications for real Skyrme functionals

Bidirectional Telemetry Controller for Neuroprosthetic Devices

Science.gov (United States)

Sharma, Vishnu; McCreery, Douglas B.; Han, Martin; Pikov, Victor

2010-01-01

We present versatile multifunctional programmable controller with bidirectional data telemetry, implemented using existing commercial microchips and standard Bluetooth protocol, which adds convenience, reliability, and ease-of-use to neuroprosthetic devices. Controller, weighing 190 g, is placed on animal's back and provides bidirectional sustained telemetry rate of 500 kb/s, allowing real-time control of stimulation parameters and viewing of acquired data. In continuously-active state, controller consumes ∼420 mW and operates without recharge for 8 h. It features independent 16-channel current-controlled stimulation, allowing current steering; customizable stimulus current waveforms; recording of stimulus voltage waveforms and evoked neuronal responses with stimulus artifact blanking circuitry. Flexibility, scalability, cost-efficiency, and a user-friendly computer interface of this device allow use in animal testing for variety of neuroprosthetic applications. Initial testing of the controller has been done in a feline model of brainstem auditory prosthesis. In this model, the electrical stimulation is applied to the array of microelectrodes implanted in the ventral cochlear nucleus, while the evoked neuronal activity was recorded with the electrode implanted in the contralateral inferior colliculus. Stimulus voltage waveforms to monitor the access impedance of the electrodes were acquired at the rate of 312 kilosamples/s. Evoked neuronal activity in the inferior colliculus was recorded after the blanking (transient silencing) of the recording amplifier during the stimulus pulse, allowing the detection of neuronal responses within 100 μs after the end of the stimulus pulse applied in the cochlear nucleus. PMID:19933010

Bidirectional telemetry controller for neuroprosthetic devices.

Science.gov (United States)

Sharma, Vishnu; McCreery, Douglas B; Han, Martin; Pikov, Victor

2010-02-01

We present versatile multifunctional programmable controller with bidirectional data telemetry, implemented using existing commercial microchips and standard Bluetooth protocol, which adds convenience, reliability, and ease-of-use to neuroprosthetic devices. Controller, weighing 190 g, is placed on animal's back and provides bidirectional sustained telemetry rate of 500 kb/s , allowing real-time control of stimulation parameters and viewing of acquired data. In continuously-active state, controller consumes approximately 420 mW and operates without recharge for 8 h . It features independent 16-channel current-controlled stimulation, allowing current steering; customizable stimulus current waveforms; recording of stimulus voltage waveforms and evoked neuronal responses with stimulus artifact blanking circuitry. Flexibility, scalability, cost-efficiency, and a user-friendly computer interface of this device allow use in animal testing for variety of neuroprosthetic applications. Initial testing of the controller has been done in a feline model of brainstem auditory prosthesis. In this model, the electrical stimulation is applied to the array of microelectrodes implanted in the ventral cochlear nucleus, while the evoked neuronal activity was recorded with the electrode implanted in the contralateral inferior colliculus. Stimulus voltage waveforms to monitor the access impedance of the electrodes were acquired at the rate of 312 kilosamples/s. Evoked neuronal activity in the inferior colliculus was recorded after the blanking (transient silencing) of the recording amplifier during the stimulus pulse, allowing the detection of neuronal responses within 100 mus after the end of the stimulus pulse applied in the cochlear nucleus.

Bidirectional Prospective Associations between Cardiac Autonomic Activity and Inflammatory Markers

NARCIS (Netherlands)

Hu, Mandy X; Lamers, Femke; Neijts, Melanie; Willemsen, Gonneke; de Geus, Eco J C; Penninx, Brenda W J H

2018-01-01

OBJECTIVE: Autonomic nervous system (ANS) imbalance has been cross-sectionally associated with inflammatory processes. Longitudinal studies are needed to shed light on the nature of this relationship. We examined cross-sectional and bidirectional prospective associations between cardiac autonomic

Transmission probability-based dynamic power control for multi-radio mesh networks

CSIR Research Space (South Africa)

Olwal, TO

2008-09-01

Full Text Available This paper presents an analytical model for the selection of the transmission power based on the bi-directional medium access information. Most of dynamic transmission power control algorithms are based on the single directional channel...

Diversification dynamics and transoceanic Eurasian-Australian disjunction in the genus Picris (Compositae) induced by the interplay of shifts in intrinsic/extrinsic traits and paleoclimatic oscillations.

Science.gov (United States)

Slovák, Marek; Kučera, Jaromír; Lack, Hans Walter; Ziffer-Berger, Jotham; Melicharková, Andrea; Záveská, Eliška; Vďačný, Peter

2018-02-01

Understanding transcontinental biogeographic patterns has been one of the main foci of the field of biogeography. While multiple explanations for transcontinental disjunctions have been proposed, little is still known about the relative importance of intrinsic and extrinsic traits for the diversification dynamics of disjunct taxa. Here, we study the evolutionary history of the genus Picris L. (Compositae), a great model for investigating the diversification dynamics of transoceanic bipolar disjunct organisms. Ancestral state reconstructions indicate that the most recent common ancestor (MRCA) of Picris was a semelparous and heterocarpic herb that lived in unpredictable environments of North Africa and West Asia. Diversification analyses suggest a significant shift in speciation ca. 1 million years ago, likely associated with the onset of the mid-Pleistocene revolution. Longevity characters are correlated with the evolution of particular fruit types and with environmental conditions. Heterocarpic species are mostly semelparous herbs strongly linked with unpredictable habitats, while homocarpic taxa are mostly iteroparous plants occurring in predictable environments. Binary-state speciation and extinction analyses suggest that homocarpy, iteroparity, and habitats predictability accelerate diversification. Although the combination of homocarpy and iteroparity evolved in several lineages, only members of the P. hieracioides group were able to colonise Eurasia and expand to Australia by transoceanic dispersal. Those findings indicate that large-scale colonisation events depend on a complex interplay of intrinsic and extrinsic factors. Copyright © 2017 Elsevier Inc. All rights reserved.

Bidirectional Associations Between Adolescents' Sexual Behaviors and Psychological Well-Being

NARCIS (Netherlands)

Nogueira Avelar e Silva, Raquel; van de Bongardt, Daphne; Baams, Laura; Raat, Hein

Purpose: Assessing bidirectional longitudinal associations between early sexual behaviors (≤16.0 years) and psychological well-being (global self-esteem, physical self-esteem, depression) among 716 adolescents, and the direct and buffering effect of parent-adolescent relationship quality. Methods:

Robust stability of interval bidirectional associative memory neural network with time delays.

Science.gov (United States)

Liao, Xiaofeng; Wong, Kwok-wo

2004-04-01

In this paper, the conventional bidirectional associative memory (BAM) neural network with signal transmission delay is intervalized in order to study the bounded effect of deviations in network parameters and external perturbations. The resultant model is referred to as a novel interval dynamic BAM (IDBAM) model. By combining a number of different Lyapunov functionals with the Razumikhin technique, some sufficient conditions for the existence of unique equilibrium and robust stability are derived. These results are fairly general and can be verified easily. To go further, we extend our investigation to the time-varying delay case. Some robust stability criteria for BAM with perturbations of time-varying delays are derived. Besides, our approach for the analysis allows us to consider several different types of activation functions, including piecewise linear sigmoids with bounded activations as well as the usual C1-smooth sigmoids. We believe that the results obtained have leading significance in the design and application of BAM neural networks.

5 kW bidirectional grid-connected drive using silicon-carbide switches: Control

DEFF Research Database (Denmark)

Kouchaki, Alireza; Lazar, Radu; Pedersen, Jacob Lykke

2017-01-01

his paper presents a controller design for a fully silicon-carbide (SiC) based bidirectional three-phase grid-connected PWM drive. For drive applications, controller must be robust and fast to be able to provide power flow in both directions. In this paper, proportional resonance (PR) current con...... magnet motor. Different tests will be conducted to evaluate the performance of the controllers in both generative and regenerative mode. It is shown that the controller can provide a good dynamic response to load changes for both direction of power flow.......-phase rectifier with switching frequency of 45 kHz will be tested. The test is done by connecting it to a grid simulator and the load is a resistive load. In the second test the rectifier will be connected to the grid via an auto-transformer and load is a 7.5kW SiC based drive which is connected to a permanent...

Intrinsic to extrinsic phonon lifetime transition in a GaAs–AlAs superlattice

International Nuclear Information System (INIS)

Hofmann, F; Garg, J; Chen, G; Maznev, A A; Nelson, K A; Jandl, A; Bulsara, M; Fitzgerald, E A

2013-01-01

We have measured the lifetimes of two zone-center longitudinal acoustic phonon modes, at 320 and 640 GHz, in a 14 nm GaAs/2 nm AlAs superlattice structure. By comparing measurements at 296 and 79 K we separate the intrinsic contribution to phonon lifetime determined by phonon–phonon scattering from the extrinsic contribution due to defects and interface roughness. At 296 K, the 320 GHz phonon lifetime has approximately equal contributions from intrinsic and extrinsic scattering, whilst at 640 GHz it is dominated by extrinsic effects. These measurements are compared with intrinsic and extrinsic scattering rates in the superlattice obtained from first-principles lattice dynamics calculations. The calculated room-temperature intrinsic lifetime of longitudinal phonons at 320 GHz is in agreement with the experimentally measured value of 0.9 ns. The model correctly predicts the transition from predominantly intrinsic to predominantly extrinsic scattering; however the predicted transition occurs at higher frequencies. Our analysis indicates that the ‘interfacial atomic disorder’ model is not entirely adequate and that the observed frequency dependence of the extrinsic scattering rate is likely to be determined by a finite correlation length of interface roughness. (paper)

Intrinsic to extrinsic phonon lifetime transition in a GaAs-AlAs superlattice.

Science.gov (United States)

Hofmann, F; Garg, J; Maznev, A A; Jandl, A; Bulsara, M; Fitzgerald, E A; Chen, G; Nelson, K A

2013-07-24

We have measured the lifetimes of two zone-center longitudinal acoustic phonon modes, at 320 and 640 GHz, in a 14 nm GaAs/2 nm AlAs superlattice structure. By comparing measurements at 296 and 79 K we separate the intrinsic contribution to phonon lifetime determined by phonon-phonon scattering from the extrinsic contribution due to defects and interface roughness. At 296 K, the 320 GHz phonon lifetime has approximately equal contributions from intrinsic and extrinsic scattering, whilst at 640 GHz it is dominated by extrinsic effects. These measurements are compared with intrinsic and extrinsic scattering rates in the superlattice obtained from first-principles lattice dynamics calculations. The calculated room-temperature intrinsic lifetime of longitudinal phonons at 320 GHz is in agreement with the experimentally measured value of 0.9 ns. The model correctly predicts the transition from predominantly intrinsic to predominantly extrinsic scattering; however the predicted transition occurs at higher frequencies. Our analysis indicates that the 'interfacial atomic disorder' model is not entirely adequate and that the observed frequency dependence of the extrinsic scattering rate is likely to be determined by a finite correlation length of interface roughness.

Intrinsic Rotation and Momentum Transport in Reversed Shear Plasmas with Internal Transport Barriers

Science.gov (United States)

Jhang, Hogun; Kim, S. S.; Diamond, P. H.

2010-11-01

The intrinsic rotation in fusion plasmas is believed to be generated via the residual stress without external momentum input. The physical mechanism responsible for the generation and transport of intrinsic rotation in L- and H-mode tokamak plasmas has been studied extensively. However, it is noted that the physics of intrinsic rotation generation and its relationship to the formation of internal transport barriers (ITBs) in reversed shear (RS) tokamak plasmas have not been explored in detail, which is the main subject in the present work. A global gyrofluid code TRB is used for this study. It is found that the large intrinsic rotation (˜10-30% of the ion sound speed depending on ITB characteristics) is generated near the ITB region and propagates into the core. The intrinsic rotation increases linearly as the temperature gradient at ITB position increases, albeit not indefinitely. Key parameters related to the symmetry breaking, such as turbulent intensity and its gradient, the flux surface averaged parallel wavenumber are evaluated dynamically during the ITB formation. The role of reversed shear and the q-profile curvature is presented in relation to the symmetry breaking mechanism in RS plasmas.

Comparing Intrinsic Connectivity Models for the Primary Auditory Cortices

Science.gov (United States)

Hamid, Khairiah Abdul; Yusoff, Ahmad Nazlim; Mohamad, Mazlyfarina; Hamid, Aini Ismafairus Abd; Manan, Hanani Abd

2010-07-01

This fMRI study is about modeling the intrinsic connectivity between Heschl' gyrus (HG) and superior temporal gyrus (STG) in human primary auditory cortices. Ten healthy male subjects participated and required to listen to white noise stimulus during the fMRI scans. Two intrinsic connectivity models comprising bilateral HG and STG were constructed using statistical parametric mapping (SPM) and dynamic causal modeling (DCM). Group Bayes factor (GBF), positive evidence ratio (PER) and Bayesian model selection (BMS) for group studies were used in model comparison. Group results indicated significant bilateral asymmetrical activation (puncorr < 0.001) in HG and STG. Comparison results showed strong evidence of Model 2 as the preferred model (STG as the input center) with GBF value of 5.77 × 1073 The model is preferred by 6 out of 10 subjects. The results were supported by BMS results for group studies. One-sample t-test on connection values obtained from Model 2 indicates unidirectional parallel connections from STG to bilateral HG (p<0.05). Model 2 was determined to be the most probable intrinsic connectivity model between bilateral HG and STG when listening to white noise.

Cross-species mapping of bidirectional promoters enables prediction of unannotated 5' UTRs and identification of species-specific transcripts

Directory of Open Access Journals (Sweden)

Lewin Harris A

2009-04-01

Full Text Available Abstract Background Bidirectional promoters are shared regulatory regions that influence the expression of two oppositely oriented genes. This type of regulatory architecture is found more frequently than expected by chance in the human genome, yet many specifics underlying the regulatory design are unknown. Given that the function of most orthologous genes is similar across species, we hypothesized that the architecture and regulation of bidirectional promoters might also be similar across species, representing a core regulatory structure and enabling annotation of these regions in additional mammalian genomes. Results By mapping the intergenic distances of genes in human, chimpanzee, bovine, murine, and rat, we show an enrichment for pairs of genes equal to or less than 1,000 bp between their adjacent 5' ends ("head-to-head" compared to pairs of genes that fall in the same orientation ("head-to-tail" or whose 3' ends are side-by-side ("tail-to-tail". A representative set of 1,369 human bidirectional promoters was mapped to orthologous sequences in other mammals. We confirmed predictions for 5' UTRs in nine of ten manual picks in bovine based on comparison to the orthologous human promoter set and in six of seven predictions in human based on comparison to the bovine dataset. The two predictions that did not have orthology as bidirectional promoters in the other species resulted from unique events that initiated transcription in the opposite direction in only those species. We found evidence supporting the independent emergence of bidirectional promoters from the family of five RecQ helicase genes, which gained their bidirectional promoters and partner genes independently rather than through a duplication process. Furthermore, by expanding our comparisons from pairwise to multispecies analyses we developed a map representing a core set of bidirectional promoters in mammals. Conclusion We show that the orthologous positions of bidirectional

Intrinsic frame transport for a model of nematic liquid crystal

Science.gov (United States)

Cozzini, S.; Rull, L. F.; Ciccotti, G.; Paolini, G. V.

1997-02-01

We present a computer simulation study of the dynamical properties of a nematic liquid crystal model. The diffusional motion of the nematic director is taken into account in our calculations in order to give a proper estimate of the transport coefficients. Differently from other groups we do not attempt to stabilize the director through rigid constraints or applied external fields. We instead define an intrinsic frame which moves along with the director at each step of the simulation. The transport coefficients computed in the intrinsic frame are then compared against the ones calculated in the fixed laboratory frame, to show the inadequacy of the latter for systems with less than 500 molecules. Using this general scheme on the Gay-Berne liquid crystal model, we evidence the natural motion of the director and attempt to quantify its intrinsic time scale and size dependence. Through extended simulations of systems of different size we calculate the diffusion and viscosity coefficients of this model and compare our results with values previously obtained with fixed director.

Mechanical and abrasive wear characterization of bidirectional and chopped E-glass fiber reinforced composite materials

International Nuclear Information System (INIS)

Siddhartha,; Gupta, Kuldeep

2012-01-01

Highlights: ► Bi-directional and chopped E-glass fiber reinforced epoxy composites are fabricated. ► Three body abrasive wear behavior of fabricated composites has been assessed. ► Results are validated against existing microscopic models of Lancaster and Wang. ► Tensile strength of bi-directional E-glass fiber reinforced composites increases. ► Chopped glass fiber composites are found better in abrasive wear situations. -- Abstract: Bi-directional and chopped E-glass fiber reinforced epoxy composites are fabricated in five different (15, 20, 25, 30 and 35) wt% in an epoxy resin matrix. The mechanical characterization of these composites is performed. The three body abrasive wear behavior of fabricated composites has been assessed under different operating conditions. Abrasive wear characteristics of these composites are successfully analysed using Taguchi’s experimental design scheme and analysis of variance (ANOVA). The results obtained from these experiments are also validated against existing microscopic models of Ratner-Lancaster and Wang. It is observed that quite good linear relationships is held between specific wear rate and reciprocal of ultimate strength and strain at tensile fracture of these composites which is an indicative that the experimental results are in fair agreement with these existing models. Out of all composites fabricated it is found that tensile strength of bi-directional E-glass fiber reinforced composites increases because of interface strength enhancement. Chopped glass fiber reinforced composites are observed to perform better than bi-directional glass fiber reinforced composites under abrasive wear situations. The morphology of worn composite specimens has been examined by scanning electron microscopy (SEM) to understand about dominant wear mechanisms.

Bidirectional Associations Between Externalizing Behavior Problems and Maladaptive Parenting Within Parent-Son Dyads Across Childhood.

Science.gov (United States)

Besemer, Sytske; Loeber, Rolf; Hinshaw, Stephen P; Pardini, Dustin A

2016-10-01

Coercive parent-child interaction models posit that an escalating cycle of negative, bidirectional interchanges influences the development of boys' externalizing problems and caregivers' maladaptive parenting over time. However, longitudinal studies examining this hypothesis have been unable to rule out the possibility that between-individual factors account for bidirectional associations between child externalizing problems and maladaptive parenting. Using a longitudinal sample of boys (N = 503) repeatedly assessed eight times across 6-month intervals in childhood (in a range between 6 and 13 years), the current study is the first to use novel within-individual change (fixed effects) models to examine whether parents tend to increase their use of maladaptive parenting strategies following an increase in their son's externalizing problems, or vice versa. These bidirectional associations were examined using multiple facets of externalizing problems (i.e., interpersonal callousness, conduct and oppositional defiant problems, hyperactivity/impulsivity) and parenting behaviors (i.e., physical punishment, involvement, parent-child communication). Analyses failed to support the notion that when boys increase their typical level of problem behaviors, their parents show an increase in their typical level of maladaptive parenting across the subsequent 6 month period, and vice versa. Instead, across 6-month intervals, within parent-son dyads, changes in maladaptive parenting and child externalizing problems waxed and waned in concert. Fixed effects models to address the topic of bidirectional relations between parent and child behavior are severely underrepresented. We recommend that other researchers who have found significant bidirectional parent-child associations using rank-order change models reexamine their data to determine whether these findings hold when examining changes within parent-child dyads.

Reward-timing-dependent bidirectional modulation of cortical microcircuits during optical single-neuron operant conditioning.

Science.gov (United States)

Hira, Riichiro; Ohkubo, Fuki; Masamizu, Yoshito; Ohkura, Masamichi; Nakai, Junichi; Okada, Takashi; Matsuzaki, Masanori

2014-11-24

Animals rapidly adapt to environmental change. To reveal how cortical microcircuits are rapidly reorganized when an animal recognizes novel reward contingency, we conduct two-photon calcium imaging of layer 2/3 motor cortex neurons in mice and simultaneously reinforce the activity of a single cortical neuron with water delivery. Here we show that when the target neuron is not relevant to a pre-trained forelimb movement, the mouse increases the target neuron activity and the number of rewards delivered during 15-min operant conditioning without changing forelimb movement behaviour. The reinforcement bidirectionally modulates the activity of subsets of non-target neurons, independent of distance from the target neuron. The bidirectional modulation depends on the relative timing between the reward delivery and the neuronal activity, and is recreated by pairing reward delivery and photoactivation of a subset of neurons. Reward-timing-dependent bidirectional modulation may be one of the fundamental processes in microcircuit reorganization for rapid adaptation.

Bidirectional automatic release of reserve for low voltage network made with low capacity PLCs

Science.gov (United States)

Popa, I.; Popa, G. N.; Diniş, C. M.; Deaconu, S. I.

2018-01-01

The article presents the design of a bidirectional automatic release of reserve made on two types low capacity programmable logic controllers: PS-3 from Klöckner-Moeller and Zelio from Schneider. It analyses the electronic timing circuits that can be used for making the bidirectional automatic release of reserve: time-on delay circuit and time-off delay circuit (two types). In the paper are present the sequences code for timing performed on the PS-3 PLC, the logical functions for the bidirectional automatic release of reserve, the classical control electrical diagram (with contacts, relays, and time relays), the electronic control diagram (with logical gates and timing circuits), the code (in IL language) made for the PS-3 PLC, and the code (in FBD language) made for Zelio PLC. A comparative analysis will be carried out on the use of the two types of PLC and will be present the advantages of using PLCs.

Studi Komparasi Fungsi Keanggotaan Fuzzy sebagai Kontroler Bidirectional DC-DC Converter pada Sistem Penyimpan Energi

Directory of Open Access Journals (Sweden)

Eka Prasetyono

2015-09-01

Full Text Available Bidirectional DC-DC converter is needed in the energy storage system. The converter topology used in this paper was a non-isolated bidirectional DC-DC buck-boost converter. This converter worked in two ways, which the charging mode stored energy into battery when load current was less than nominal main DC current (set point and discharging mode transferred energy from battery to the load when its current exceeded set point value. Both of these modes worked automatically according to the load current. The charging and discharging currents were controlled by fuzzy logic controller which was implemented on microcontroller ARM Cortex-M4F STM32F407VG. This paper compares two types of fuzzy membership function (triangular and sigmoid in controlling bidirectional DC-DC converter. The results showed that fuzzy logic controller with triangle membership function and sigmoid as control bidirectional DC-DC converter had no significant different response, both had an average error for charging and discharging process under 4% with ripple current on the main DC bus around 0.5%. The computing time of program for fuzzy logic controller with triangular membership functions had 19.01% faster than sigmoid, and fuzzy logic computation time on a microcontroller with hardware floating point was 60% faster than software floating point.

A novel bidirectional expression system for simultaneous expression of both the protein-coding genes and short hairpin RNAs in mammalian cells

International Nuclear Information System (INIS)

Hung, C.-F.; Cheng, T.-L.; Wu, R.-H.; Teng, C.-F.; Chang, W.-T.

2006-01-01

RNA interference (RNAi) is an extremely powerful and widely used gene silencing approach for reverse functional genomics and molecular therapeutics. In mammals, the conserved poly(ADP-ribose) polymerase 2 (PARP-2)/RNase P bidirectional control promoter simultaneously expresses both the PARP-2 protein and RNase P RNA by RNA polymerase II- and III-dependent mechanisms, respectively. To explore this unique bidirectional control system in RNAi-mediated gene silencing strategy, we have constructed two novel bidirectional expression vectors, pbiHsH1 and pbiMmH1, which contained the PARP-2/RNase P bidirectional control promoters from human and mouse, for simultaneous expression of both the protein-coding genes and short hairpin RNAs. Analyses of the dual transcriptional activities indicated that these two bidirectional expression vectors could not only express enhanced green fluorescent protein as a functional reporter but also simultaneously transcribe shLuc for inhibiting the firefly luciferase expression. In addition, to extend its utility for the establishment of inherited stable clones, we have also reconstructed this bidirectional expression system with the blasticidin S deaminase gene, an effective dominant drug resistance selectable marker, and examined both the selection and inhibition efficiencies in drug resistance and gene expression. Moreover, we have further demonstrated that this bidirectional expression system could efficiently co-regulate the functionally important genes, such as overexpression of tumor suppressor protein p53 and inhibition of anti-apoptotic protein Bcl-2 at the same time. In summary, the bidirectional expression vectors, pbiHsH1 and pbiMmH1, should provide a simple, convenient, and efficient novel tool for manipulating the gene function in mammalian cells

Integrating high dimensional bi-directional parsing models for gene mention tagging.

Science.gov (United States)

Hsu, Chun-Nan; Chang, Yu-Ming; Kuo, Cheng-Ju; Lin, Yu-Shi; Huang, Han-Shen; Chung, I-Fang

2008-07-01

Tagging gene and gene product mentions in scientific text is an important initial step of literature mining. In this article, we describe in detail our gene mention tagger participated in BioCreative 2 challenge and analyze what contributes to its good performance. Our tagger is based on the conditional random fields model (CRF), the most prevailing method for the gene mention tagging task in BioCreative 2. Our tagger is interesting because it accomplished the highest F-scores among CRF-based methods and second over all. Moreover, we obtained our results by mostly applying open source packages, making it easy to duplicate our results. We first describe in detail how we developed our CRF-based tagger. We designed a very high dimensional feature set that includes most of information that may be relevant. We trained bi-directional CRF models with the same set of features, one applies forward parsing and the other backward, and integrated two models based on the output scores and dictionary filtering. One of the most prominent factors that contributes to the good performance of our tagger is the integration of an additional backward parsing model. However, from the definition of CRF, it appears that a CRF model is symmetric and bi-directional parsing models will produce the same results. We show that due to different feature settings, a CRF model can be asymmetric and the feature setting for our tagger in BioCreative 2 not only produces different results but also gives backward parsing models slight but constant advantage over forward parsing model. To fully explore the potential of integrating bi-directional parsing models, we applied different asymmetric feature settings to generate many bi-directional parsing models and integrate them based on the output scores. Experimental results show that this integrated model can achieve even higher F-score solely based on the training corpus for gene mention tagging. Data sets, programs and an on-line service of our gene

Intrinsic information carriers in combinatorial dynamical systems

Science.gov (United States)

Harmer, Russ; Danos, Vincent; Feret, Jérôme; Krivine, Jean; Fontana, Walter

2010-09-01

Many proteins are composed of structural and chemical features—"sites" for short—characterized by definite interaction capabilities, such as noncovalent binding or covalent modification of other proteins. This modularity allows for varying degrees of independence, as the behavior of a site might be controlled by the state of some but not all sites of the ambient protein. Independence quickly generates a startling combinatorial complexity that shapes most biological networks, such as mammalian signaling systems, and effectively prevents their study in terms of kinetic equations—unless the complexity is radically trimmed. Yet, if combinatorial complexity is key to the system's behavior, eliminating it will prevent, not facilitate, understanding. A more adequate representation of a combinatorial system is provided by a graph-based framework of rewrite rules where each rule specifies only the information that an interaction mechanism depends on. Unlike reactions, which deal with molecular species, rules deal with patterns, i.e., multisets of molecular species. Although the stochastic dynamics induced by a collection of rules on a mixture of molecules can be simulated, it appears useful to capture the system's average or deterministic behavior by means of differential equations. However, expansion of the rules into kinetic equations at the level of molecular species is not only impractical, but conceptually indefensible. If rules describe bona fide patterns of interaction, molecular species are unlikely to constitute appropriate units of dynamics. Rather, we must seek aggregate variables reflective of the causal structure laid down by the rules. We call these variables "fragments" and the process of identifying them "fragmentation." Ideally, fragments are aspects of the system's microscopic population that the set of rules can actually distinguish on average; in practice, it may only be feasible to identify an approximation to this. Most importantly, fragments are

Intrinsic information carriers in combinatorial dynamical systems.

Science.gov (United States)

Harmer, Russ; Danos, Vincent; Feret, Jérôme; Krivine, Jean; Fontana, Walter

2010-09-01

Many proteins are composed of structural and chemical features--"sites" for short--characterized by definite interaction capabilities, such as noncovalent binding or covalent modification of other proteins. This modularity allows for varying degrees of independence, as the behavior of a site might be controlled by the state of some but not all sites of the ambient protein. Independence quickly generates a startling combinatorial complexity that shapes most biological networks, such as mammalian signaling systems, and effectively prevents their study in terms of kinetic equations-unless the complexity is radically trimmed. Yet, if combinatorial complexity is key to the system's behavior, eliminating it will prevent, not facilitate, understanding. A more adequate representation of a combinatorial system is provided by a graph-based framework of rewrite rules where each rule specifies only the information that an interaction mechanism depends on. Unlike reactions, which deal with molecular species, rules deal with patterns, i.e., multisets of molecular species. Although the stochastic dynamics induced by a collection of rules on a mixture of molecules can be simulated, it appears useful to capture the system's average or deterministic behavior by means of differential equations. However, expansion of the rules into kinetic equations at the level of molecular species is not only impractical, but conceptually indefensible. If rules describe bona fide patterns of interaction, molecular species are unlikely to constitute appropriate units of dynamics. Rather, we must seek aggregate variables reflective of the causal structure laid down by the rules. We call these variables "fragments" and the process of identifying them "fragmentation." Ideally, fragments are aspects of the system's microscopic population that the set of rules can actually distinguish on average; in practice, it may only be feasible to identify an approximation to this. Most importantly, fragments are

Control of parallel-connected bidirectional AC-DC converters in stationary frame for microgrid application

DEFF Research Database (Denmark)

Lu, Xiaonan; Guerrero, Josep M.; Teodorescu, Remus

2011-01-01

With the penetration of renewable energy in modern power system, microgrid has become a popular application worldwide. In this paper, parallel-connected bidirectional converters for AC and DC hybrid microgrid application are proposed as an efficient interface. To reach the goal of bidirectional...... power conversion, both rectifier and inverter modes are analyzed. In order to achieve high performance operation, hierarchical control system is accomplished. The control system is designed in stationary frame, with harmonic compensation in parallel and no coupled terms between axes. In this control...

Intrinsic periodicity: the forgotten lesson of quantum mechanics

International Nuclear Information System (INIS)

Dolce, Donatello

2013-01-01

Wave-particle duality, together with the concept of elementary particles, was introduced by de Broglie in terms of intrinsically periodic phenomena. However, after nearly 90 years, the physical origin of such undulatory mechanics remains unrevealed. We propose a natural realization of the de Broglie periodic phenomenon in terms of harmonic vibrational modes associated to space-time periodicities. In this way we find that, similarly to a vibrating string or a particle in a box, the intrinsic recurrence imposed as a constraint to elementary particles represents a fully consistent quantization condition. The resulting cyclic dynamics formally match ordinary relativistic Quantum Mechanics in both the canonical and Feynman formulations. Interactions are introduced in a geometrodynamical way, similarly to general relativity, by simply considering that variations of kinematical state can be equivalently described in terms of modulations of space-time recurrences, as known from undulatory mechanics. We present this novel quantization prescription from an historical prospective.

Colours sometimes count : Awareness and bidirectionality in grapheme-colour synaesthesia

NARCIS (Netherlands)

Johnson, Addie; Jepma, Marieke; de Jong, Ritske

2007-01-01

Three experiments were conducted with 10 grapheme-colour synaesthetes and 10 matched controls to investigate (a) whether awareness of the inducer grapheme is necessary for synaesthetic colour induction and (b) whether grapheme-colour synaesthesia may be bidirectional in the sense that not only do

Bidirectional electrostatic linear shuffle motor with two degrees of freedom

NARCIS (Netherlands)

Sarajlic, Edin; Berenschot, Johan W.; Fujita, H.; Krijnen, Gijsbertus J.M.; Elwenspoek, Michael Curt

2005-01-01

We report on an electrostatic linear inchworm micromotor with two translational degrees-of-freedom. The motor employs built-in mechanical leverage to convert normal deflection of a flexible cross-plate into a small in-plane step and four electrostatic clamps to enable bidirectional inchworm motion

Magnetically actuated bi-directional microactuators with permalloy and Fe/Pt hard magnet

International Nuclear Information System (INIS)

Pan, C.T.; Shen, S.C.

2005-01-01

Bi-directional polyimide (PI) electromagnetic microactuator with different geometries are designed, fabricated and tested. Fabrication of the electromagnetic microactuator consists of 10 μm thick Ni/Fe (80/20) permalloy deposition on the PI diaphragm by electroplating, high aspect ratio electroplating of copper planar coil with 10 μm in thickness, bulk micromachining, and excimer laser selective ablation. They were fabricated by a novel concept avoiding the etching selectivity and residual stress problems during wafer etching. A mathematical model is created by ANSYS software to analyze the microactuator. The external magnetic field intensity (H ext ) generated by the planar coil is simulated by ANSYS software. ANSYS software is used to predict the deflection angle of the microactuator. Besides, to provide bi-directional and large deflection angle of microactuator, hard magnet Fe/Pt is deposited at a low temperature of 300 deg. C by sputtering onto the PI diaphragm to produce a perpendicular magnetic anisotropic field. This magnetic field can enhance the interaction with H ext to induce attractive and repulsive bi-directional force to provide large displacement. The results of magnetic microactuator with and without hard magnets are compared and discussed. The preliminary result reveals that the electromagnetic microactuator with hard magnet shows a greater deflection angle than that without one

Entropy squeezing for a two-level atom in two-mode Raman coupled model with intrinsic decoherence

Institute of Scientific and Technical Information of China (English)

Zhang Jian; Shao Bin; Zou Jian

2009-01-01

In this paper,we investigate the entropy squeezing for a two-level atom interacting with two quantized fields through Raman coupling.We obtain the dynamical evolution of the total system under the influence of intrinsic decoherence when the two quantized fields are prepared in a two-mode squeezing vacuum state initially.The effects of the field squeezing factor,the two-level atomic transition frequency,the second field frequency and the intrinsic decoherence on the entropy squeezing are discussed.Without intrinsic decoherence,the increase of field squeezing factor can break the entropy squeezing.The two-level atomic transition frequency changes only the period of oscillation but not the strength of entropy squeezing.The influence of the second field frequency is complicated.With the intrinsic decoherence taken into consideration,the results show that the stronger the intrinsic decoherence is,the more quickly the entropy squeezing will disappear.The increase of the atomic transition frequency can hasten the disappearance of entropy squeezing.

Entropy squeezing for a two-level atom in two-mode Raman coupled model with intrinsic decoherence

International Nuclear Information System (INIS)

Jian, Zhang; Bin, Shao; Jian, Zou

2009-01-01

In this paper, we investigate the entropy squeezing for a two-level atom interacting with two quantized fields through Raman coupling. We obtain the dynamical evolution of the total system under the influence of intrinsic decoherence when the two quantized fields are prepared in a two-mode squeezing vacuum state initially. The effects of the field squeezing factor, the two-level atomic transition frequency, the second field frequency and the intrinsic decoherence on the entropy squeezing are discussed. Without intrinsic decoherence, the increase of field squeezing factor can break the entropy squeezing. The two-level atomic transition frequency changes only the period of oscillation but not the strength of entropy squeezing. The influence of the second field frequency is complicated. With the intrinsic decoherence taken into consideration, the results show that the stronger the intrinsic decoherence is, the more quickly the entropy squeezing will disappear. The increase of the atomic transition frequency can hasten the disappearance of entropy squeezing. (classical areas of phenomenology)

Interplanetary magnetic field orientations associated with bidirectional electron heat fluxes detected at ISEE 3

International Nuclear Information System (INIS)

Stansberry, J.A.; Gosling, J.T.; Thomsen, M.F.; Bame, S.J.; Smith, E.J.

1988-01-01

A statistical survey of interplanetary magnetic field orientations associated with bidirectional electron heat fluxes observed at ISEE 3 in orbit about the Sunward Lagrange point indicates that magnetic connection of the spacecraft to the Earth's bow shock was frequently the source of the bidirectionality. When the interplanetary magnetic field was oriented within 5 0 of the Earth-spacecraft line, backstreaming electrons from the bow shock were clearly observed approximately 18% of the time, and connections apparently occurred for angles as large as ∼30 0 --35 0 . copyright American Geophysical Union 1988

Complex-Dynamic Cosmology and Emergent World Structure

OpenAIRE

Kirilyuk, Andrei P.

2004-01-01

Universe structure emerges in the unreduced, complex-dynamic interaction process with the simplest initial configuration (two attracting homogeneous fields, quant-ph/9902015). The unreduced interaction analysis gives intrinsically creative cosmology, describing the real, explicitly emerging world structure with dynamic randomness on each scale. Without imposing any postulates or entities, we obtain physically real space, time, elementary particles with their detailed structure and intrinsic p...

Dynamic Correlations between Intrinsic Connectivity and Extrinsic Connectivity of the Auditory Cortex in Humans.

Science.gov (United States)

Cui, Zhuang; Wang, Qian; Gao, Yayue; Wang, Jing; Wang, Mengyang; Teng, Pengfei; Guan, Yuguang; Zhou, Jian; Li, Tianfu; Luan, Guoming; Li, Liang

2017-01-01

The arrival of sound signals in the auditory cortex (AC) triggers both local and inter-regional signal propagations over time up to hundreds of milliseconds and builds up both intrinsic functional connectivity (iFC) and extrinsic functional connectivity (eFC) of the AC. However, interactions between iFC and eFC are largely unknown. Using intracranial stereo-electroencephalographic recordings in people with drug-refractory epilepsy, this study mainly investigated the temporal dynamic of the relationships between iFC and eFC of the AC. The results showed that a Gaussian wideband-noise burst markedly elicited potentials in both the AC and numerous higher-order cortical regions outside the AC (non-auditory cortices). Granger causality analyses revealed that in the earlier time window, iFC of the AC was positively correlated with both eFC from the AC to the inferior temporal gyrus and that to the inferior parietal lobule. While in later periods, the iFC of the AC was positively correlated with eFC from the precentral gyrus to the AC and that from the insula to the AC. In conclusion, dual-directional interactions occur between iFC and eFC of the AC at different time windows following the sound stimulation and may form the foundation underlying various central auditory processes, including auditory sensory memory, object formation, integrations between sensory, perceptional, attentional, motor, emotional, and executive processes.

Bidirectional Relations between Authoritative Parenting and Adolescents' Prosocial Behaviors

Science.gov (United States)

Padilla-Walker, Laura M.; Carlo, Gustavo; Christensen, Katherine J.; Yorgason, Jeremy B.

2012-01-01

This study examined the bidirectional relations between authoritative parenting and adolescents' prosocial behavior over a 1-year time period. Data were taken from Time 2 and 3 of the Flourishing Families Project, and included reports from 319 two-parent families with an adolescent child (M age of child at Time 2 = 12.34, SD = 1.06, 52% girls).…

Bidirectional Tachycardia after an Acute Intravenous Administration of Digitalis for a Suicidal Gesture

Directory of Open Access Journals (Sweden)

Diletta Sabatini

2014-01-01

Full Text Available Acute digoxin intoxication is a life-threating condition associated with severe cardiotoxicity. Female gender, age, low lean body mass, hypertension, and renal insufficiency may worsen the prognosis. Arrhythmias caused by digitalis glycosides are characterized by an increased automaticity coupled with concomitant conduction delay. Bidirectional tachycardia is pathognomonic of digoxin intoxication, but it is rarely observed. An 83-year-old woman was admitted to the Emergency Department after self-administration of 5 mg of digoxin i.v. for suicidal purpose. Her digoxin serum concentration was 17.4 ng/mL. The patient developed a bidirectional tachycardia and the Poison Control Center of the hospital provided digoxin immune fab. Bidirectional tachycardia quickly reversed and the patient remained stable throughout the hospital stay. This case shows that a multiple disciplinary approach, involving cardiologists and toxicologists, is essential for the management of digoxin intoxication. The optimal treatment of this rare event depends on the clinical conditions and on the serum drug concentration of the patient. Digoxin immune fab represents a safe, effective, and specific method for rapidly reversing digitalis cardiotoxicity and should be started as soon as the diagnosis is defined.

Bidirectional Associations between Peer Relations and Attention Problems from 9 to 16 Years.

Science.gov (United States)

Ji, Linqin; Pan, Bin; Zhang, Wenxin; Zhang, Liang; Chen, Liang; Deater-Deckard, Kirby

2018-05-12

We examined the bidirectional relations between peer relations and attention problems from middle childhood through adolescence. Using data from the Longitudinal Study of Chinese Children and Adolescents (LSCCA, N = 2157, 51.9% male), three key aspects of peer relations (acceptance, rejection, and victimization) were assessed annually from 9 to 16 years of age. Attention problems were assessed at 9 and 15 years. Latent growth modeling indicated that greater attention problems at age 9 were linked with a lower intercept for peer acceptance, and higher intercepts for rejection and victimization. Also, prior lower acceptance and greater rejection and victimization, along with a higher increase over time in rejection and lower decrease over time in victimization, predicted attention problems at age 15. Cross-lagged analysis showed that attention problems were associated with less subsequent peer acceptance and greater subsequent rejection and victimization. Only peer rejection (but neither victimization nor acceptance) predicted more subsequent attention problems. Findings point to bidirectional associations between attention problems and peer relations in the developmental transition across adolescence. Evidence for differential bidirectionality of attention problems with the multiple peer experience (group versus dyadic; good versus bad) emerged, and future replications are needed.

Bidirectional composition on lie groups for gradient-based image alignment.

Science.gov (United States)

Mégret, Rémi; Authesserre, Jean-Baptiste; Berthoumieu, Yannick

2010-09-01

In this paper, a new formulation based on bidirectional composition on Lie groups (BCL) for parametric gradient-based image alignment is presented. Contrary to the conventional approaches, the BCL method takes advantage of the gradients of both template and current image without combining them a priori. Based on this bidirectional formulation, two methods are proposed and their relationship with state-of-the-art gradient based approaches is fully discussed. The first one, i.e., the BCL method, relies on the compositional framework to provide the minimization of the compensated error with respect to an augmented parameter vector. The second one, the projected BCL (PBCL), corresponds to a close approximation of the BCL approach. A comparative study is carried out dealing with computational complexity, convergence rate and frequence of convergence. Numerical experiments using a conventional benchmark show the performance improvement especially for asymmetric levels of noise, which is also discussed from a theoretical point of view.

Bidirectional Retroviral Integration Site PCR Methodology and Quantitative Data Analysis Workflow.

Science.gov (United States)

Suryawanshi, Gajendra W; Xu, Song; Xie, Yiming; Chou, Tom; Kim, Namshin; Chen, Irvin S Y; Kim, Sanggu

2017-06-14

Integration Site (IS) assays are a critical component of the study of retroviral integration sites and their biological significance. In recent retroviral gene therapy studies, IS assays, in combination with next-generation sequencing, have been used as a cell-tracking tool to characterize clonal stem cell populations sharing the same IS. For the accurate comparison of repopulating stem cell clones within and across different samples, the detection sensitivity, data reproducibility, and high-throughput capacity of the assay are among the most important assay qualities. This work provides a detailed protocol and data analysis workflow for bidirectional IS analysis. The bidirectional assay can simultaneously sequence both upstream and downstream vector-host junctions. Compared to conventional unidirectional IS sequencing approaches, the bidirectional approach significantly improves IS detection rates and the characterization of integration events at both ends of the target DNA. The data analysis pipeline described here accurately identifies and enumerates identical IS sequences through multiple steps of comparison that map IS sequences onto the reference genome and determine sequencing errors. Using an optimized assay procedure, we have recently published the detailed repopulation patterns of thousands of Hematopoietic Stem Cell (HSC) clones following transplant in rhesus macaques, demonstrating for the first time the precise time point of HSC repopulation and the functional heterogeneity of HSCs in the primate system. The following protocol describes the step-by-step experimental procedure and data analysis workflow that accurately identifies and quantifies identical IS sequences.

Bidirectional Microglia-Neuron Communication in the Healthy Brain

Directory of Open Access Journals (Sweden)

Ukpong B. Eyo

2013-01-01

Full Text Available Unlike other resident neural cells that are of neuroectodermal origin, microglia are resident neural cells of mesodermal origin. Traditionally recognized for their immune functions during disease, new roles are being attributed to these cells in the development and maintenance of the central nervous system (CNS including specific communication with neurons. In this review, we highlight some of the recent findings on the bidirectional interaction between neurons and microglia. We discuss these interactions along two lines. First, we review data that suggest that microglial activity is modulated by neuronal signals, focusing on evidence that (i neurons are capable of regulating microglial activation state and influence basal microglial activities; (ii classic neurotransmitters affect microglial behavior; (iii chemotactic signals attract microglia during acute neuronal injury. Next, we discuss some of the recent data on how microglia signal to neurons. Signaling mechanisms include (i direct physical contact of microglial processes with neuronal elements; (ii microglial regulation of neuronal synapse and circuit by fractalkine, complement, and DAP12 signaling. In addition, we discuss the use of microglial depletion strategies in studying the role of microglia in neuronal development and synaptic physiology. Deciphering the mechanisms of bidirectional microglial-neuronal communication provides novel insights in understanding microglial function in both the healthy and diseased brain.

Performance analysis and comparison of a minimum interconnections direct storage model with traditional neural bidirectional memories.

Science.gov (United States)

Bhatti, A Aziz

2009-12-01

This study proposes an efficient and improved model of a direct storage bidirectional memory, improved bidirectional associative memory (IBAM), and emphasises the use of nanotechnology for efficient implementation of such large-scale neural network structures at a considerable lower cost reduced complexity, and less area required for implementation. This memory model directly stores the X and Y associated sets of M bipolar binary vectors in the form of (MxN(x)) and (MxN(y)) memory matrices, requires O(N) or about 30% of interconnections with weight strength ranging between +/-1, and is computationally very efficient as compared to sequential, intraconnected and other bidirectional associative memory (BAM) models of outer-product type that require O(N(2)) complex interconnections with weight strength ranging between +/-M. It is shown that it is functionally equivalent to and possesses all attributes of a BAM of outer-product type, and yet it is simple and robust in structure, very large scale integration (VLSI), optical and nanotechnology realisable, modular and expandable neural network bidirectional associative memory model in which the addition or deletion of a pair of vectors does not require changes in the strength of interconnections of the entire memory matrix. The analysis of retrieval process, signal-to-noise ratio, storage capacity and stability of the proposed model as well as of the traditional BAM has been carried out. Constraints on and characteristics of unipolar and bipolar binaries for improved storage and retrieval are discussed. The simulation results show that it has log(e) N times higher storage capacity, superior performance, faster convergence and retrieval time, when compared to traditional sequential and intraconnected bidirectional memories.

Intramolecular interactions stabilizing compact conformations of the intrinsically disordered kinase-inhibitor domain of Sic1: a molecular dynamics investigation.

Directory of Open Access Journals (Sweden)

Matteo eLambrughi

2012-11-01

Full Text Available Cyclin-dependent kinase inhibitors (CKIs are key regulatory proteins of the eukaryotic cell cycle, which modulate cyclin-dependent kinase (Cdk activity. CKIs perform their inhibitory effect by the formation of ternary complexes with a target kinase and its cognate cyclin. These regulators generally belong to the class of intrinsically disordered proteins (IDPs, which lack a well-defined and organized three-dimensional structure in their free state, undergoing folding upon binding to specific partners. Unbound IDPs are not merely random-coil structures, but can present intrinsically folded structural units (IFSUs and collapsed conformations. These structural features can be relevant to protein function in vivo.The yeast CKI Sic1 is a 284-amino acid IDP that binds to Cdk1 in complex with the Clb5,6 cyclins, preventing phosphorylation of G1 substrates and, therefore, entrance to the S phase. Sic1 degradation, triggered by multiple phosphorylation events, promotes cell-cycle progression. Previous experimental studies pointed out a propensity of Sic1 and its isolated domains to populate both extended and compact conformations. The present contribution provides models of the compact conformations of the Sic1 kinase-inhibitory domain (KID by all-atom molecular-dynamics simulations in explicit solvent and in the absence of interactors. The results are integrated by spectroscopic and spectrometric data. Helical IFSUs are identified, along with networks of intramolecular interactions. The results identify a group of hub residues and electrostatic interactions which are likely to be involved in the stabilization of globular states.

Restoring natural sensory feedback in real-time bidirectional hand prostheses

DEFF Research Database (Denmark)

Raspopovic, Stanisa; Capogrosso, Marco; Petrini, Francesco Maria

2014-01-01

Hand loss is a highly disabling event that markedly affects the quality of life. To achieve a close to natural replacement for the lost hand, the user should be provided with the rich sensations that we naturally perceive when grasping or manipulating an object. Ideal bidirectional hand prosthese...

Bidirectional converter interface for a battery energy storage test bench

DEFF Research Database (Denmark)

Trintis, Ionut; Thomas, Stephan; Blank, Tobias

2011-01-01

This paper presents the bidirectional converter interface for a 6 kV battery energy storage test bench. The power electronic interface consists a two stage converter topology having a low voltage dc-ac grid connected converter and a new dual active bridge dc-dc converter with high transformation...

High-power three-port three-phase bidirectional DC-DC converter

NARCIS (Netherlands)

Tao, H.; Duarte, J.L.; Hendrix, M.A.M.

2007-01-01

This paper proposes a three-port three-phase bidirectional dc-dc converter suitable for high-power applications. The converter combines a slow primary source and a fast storage to power a common load (e.g., an inverter). Since this type of system is gaining popularity in sustainable energy

Impact of Interference in Coexisting Wireless Networks with Applications to Arbitrarily Varying Bidirectional Broadcast Channels

Directory of Open Access Journals (Sweden)

Holger Boche

2012-08-01

Full Text Available The paradigm shift from an exclusive allocation of frequency bands, one for each system, to a shared use of frequencies comes along with the need of new concepts since interference will be an ubiquitous phenomenon. In this paper, we use the concept of arbitrarily varying channels to model the impact of unknown interference caused by coexisting wireless systems which operate on the same frequencies. Within this framework, capacity can be zero if pre-specified encoders and decoders are used. This necessitates the use of more sophisticated coordination schemes where the choice of encoders and decoders is additionally coordinated based on common randomness. As an application we study the arbitrarily varying bidirectional broadcast channel and derive the capacity regions for different coordination strategies. This problem is motivated by decode-and-forward bidirectional or two-way relaying, where a relay establishes a bidirectional communication between two other nodes while sharing the resources with other coexisting wireless networks.

Bidirectional reflectance distribution function modeling of one-dimensional rough surface in the microwave band

International Nuclear Information System (INIS)

Guo Li-Xin; Gou Xue-Yin; Zhang Lian-Bo

2014-01-01

In this study, the bidirectional reflectance distribution function (BRDF) of a one-dimensional conducting rough surface and a dielectric rough surface are calculated with different frequencies and roughness values in the microwave band by using the method of moments, and the relationship between the bistatic scattering coefficient and the BRDF of a rough surface is expressed. From the theory of the parameters of the rough surface BRDF, the parameters of the BRDF are obtained using a genetic algorithm. The BRDF of a rough surface is calculated using the obtained parameter values. Further, the fitting values and theoretical calculations of the BRDF are compared, and the optimization results are in agreement with the theoretical calculation results. Finally, a reference for BRDF modeling of a Gaussian rough surface in the microwave band is provided by the proposed method. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

Bidirectional relations between work-related stress, sleep quality and perseverative cognition

NARCIS (Netherlands)

Laethem, M. van; Beckers, D.G.J.; Kompier, M.A.J.; Kecklund, L.G.; Bossche, S.N.J. van den; Geurts, S.A.E.

2015-01-01

Objective In this longitudinal two-wave study, bidirectional relations between work-related stress and sleep quality were examined. Moreover, it was investigated whether perseverative cognition is a potential underlying mechanism in this association, related to both work-related stress and sleep

Optimized Free Energies from Bidirectional Single-Molecule Force Spectroscopy

Science.gov (United States)

Minh, David D. L.; Adib, Artur B.

2008-05-01

An optimized method for estimating path-ensemble averages using data from processes driven in opposite directions is presented. Based on this estimator, bidirectional expressions for reconstructing free energies and potentials of mean force from single-molecule force spectroscopy—valid for biasing potentials of arbitrary stiffness—are developed. Numerical simulations on a model potential indicate that these methods perform better than unidirectional strategies.

Bidirectional Associations among Sensitive Parenting, Language Development, and Social Competence

Science.gov (United States)

Barnett, Melissa A.; Gustafsson, Hanna; Deng, Min; Mills-Koonce, W. Roger; Cox, Martha

2012-01-01

Rapid changes in language skills and social competence, both of which are linked to sensitive parenting, characterize early childhood. The present study examines bidirectional associations among mothers' sensitive parenting and children's language skills and social competence from 24 to 36?months in a community sample of 174 families. In addition,…

"Figuring" Bidirectional Home and School Connections along the Biliteracy Continuum

Science.gov (United States)

Fránquiz, María E.; Leija, María G.; Garza, Irene

2015-01-01

This article centers on the significant practices identified by bilingual teachers who participated in Proyecto Bilingüe, a specialized master's degree program. The notion of bidirectional theory of bilingual pedagogy and the theoretical construct of the continua of biliteracy are utilized to illustrate how the teachers centered home and school…

TOOL ASSEMBLY WITH BI-DIRECTIONAL BEARING

Science.gov (United States)

Longhurst, G.E.

1961-07-11

A two-direction motion bearing which is incorporated in a refueling nuclear fuel element trsnsfer tool assembly is described. A plurality of bi- directional bearing assembliesare fixed equi-distantly about the circumference of the transfer tool assembly to provide the tool assembly with a bearing surface- for both axial and rotational motion. Each bi-directional bearing assembly contains a plurality of circumferentially bulged rollers mounted in a unique arrangement which will provide a bearing surface for rotational movement of the tool assembly within a bore. The bi-direc tional bearing assembly itself is capable of rational motion and thus provides for longitudinal movement of the tool assembly.

Genome-Wide Prediction of Intrinsic Disorder; Sequence Alignment of Intrinsically Disordered Proteins

Science.gov (United States)

Midic, Uros

2012-01-01

Intrinsic disorder (ID) is defined as a lack of stable tertiary and/or secondary structure under physiological conditions in vitro. Intrinsically disordered proteins (IDPs) are highly abundant in nature. IDPs possess a number of crucial biological functions, being involved in regulation, recognition, signaling and control, e.g. their functional…

Magnetic Alignment of Block Copolymer Microdomains by Intrinsic Chain Anisotropy.

Science.gov (United States)

Rokhlenko, Yekaterina; Gopinadhan, Manesh; Osuji, Chinedum O; Zhang, Kai; O'Hern, Corey S; Larson, Steven R; Gopalan, Padma; Majewski, Paweł W; Yager, Kevin G

2015-12-18

We examine the role of intrinsic chain susceptibility anisotropy in magnetic field directed self-assembly of a block copolymer using in situ x-ray scattering. Alignment of a lamellar mesophase is observed on cooling across the disorder-order transition with the resulting orientational order inversely proportional to the cooling rate. We discuss the origin of the susceptibility anisotropy, Δχ, that drives alignment and calculate its magnitude using coarse-grained molecular dynamics to sample conformations of surface-tethered chains, finding Δχ≈2×10^{-8}. From field-dependent scattering data, we estimate that grains of ≈1.2  μm are present during alignment. These results demonstrate that intrinsic anisotropy is sufficient to support strong field-induced mesophase alignment and suggest a versatile strategy for field control of orientational order in block copolymers.

Bi-directional gene set enrichment and canonical correlation analysis identify key diet-sensitive pathways and biomarkers of metabolic syndrome

Directory of Open Access Journals (Sweden)

Gaora Peadar Ó

2010-10-01

Full Text Available Abstract Background Currently, a number of bioinformatics methods are available to generate appropriate lists of genes from a microarray experiment. While these lists represent an accurate primary analysis of the data, fewer options exist to contextualise those lists. The development and validation of such methods is crucial to the wider application of microarray technology in the clinical setting. Two key challenges in clinical bioinformatics involve appropriate statistical modelling of dynamic transcriptomic changes, and extraction of clinically relevant meaning from very large datasets. Results Here, we apply an approach to gene set enrichment analysis that allows for detection of bi-directional enrichment within a gene set. Furthermore, we apply canonical correlation analysis and Fisher's exact test, using plasma marker data with known clinical relevance to aid identification of the most important gene and pathway changes in our transcriptomic dataset. After a 28-day dietary intervention with high-CLA beef, a range of plasma markers indicated a marked improvement in the metabolic health of genetically obese mice. Tissue transcriptomic profiles indicated that the effects were most dramatic in liver (1270 genes significantly changed; p Conclusion Bi-directional gene set enrichment analysis more accurately reflects dynamic regulatory behaviour in biochemical pathways, and as such highlighted biologically relevant changes that were not detected using a traditional approach. In such cases where transcriptomic response to treatment is exceptionally large, canonical correlation analysis in conjunction with Fisher's exact test highlights the subset of pathways showing strongest correlation with the clinical markers of interest. In this case, we have identified selenoamino acid metabolism and steroid biosynthesis as key pathways mediating the observed relationship between metabolic health and high-CLA beef. These results indicate that this type of

Investigations of bi-directional flow behaviour of a large vertical opening in containment

International Nuclear Information System (INIS)

Sharma, Pavan K.; Markandeya, S.G.; Ghosh, A.K.; Kushwaha, H.S.

2002-01-01

Full text: In the complex codes developed for fire analysis and for containment thermal hydraulic analysis. The junction in the multi-compartment geometries are often modeled as uni-directional junctions. However, certain large size junctions are known to depict bi-directional flow behaviour under specific circumstances. Detailed investigations have been carried out to understand the bi-directionality of a junction by analyzing an earlier reported case study of fire in an enclosure. A computer code FDS was used for the analysis. The paper presents the details of the analysis, the results obtained and further studies required to be conducted so that the findings can be applied to the fire/containment thermal hydraulics analysis codes successfully

A Bidirectional Generalized Synchronization Theorem-Based Chaotic Pseudo-random Number Generator

Directory of Open Access Journals (Sweden)

Han Shuangshuang

2013-07-01

Full Text Available Based on a bidirectional generalized synchronization theorem for discrete chaos system, this paper introduces a new 5-dimensional bidirectional generalized chaos synchronization system (BGCSDS, whose prototype is a novel chaotic system introduced in [12]. Numerical simulation showed that two pair variables of the BGCSDS achieve generalized chaos synchronization via a transform H.A chaos-based pseudo-random number generator (CPNG was designed by the new BGCSDS. Using the FIPS-140-2 tests issued by the National Institute of Standard and Technology (NIST verified the randomness of the 1000 binary number sequences generated via the CPNG and the RC4 algorithm respectively. The results showed that all the tested sequences passed the FIPS-140-2 tests. The confidence interval analysis showed the statistical properties of the randomness of the sequences generated via the CPNG and the RC4 algorithm do not have significant differences.

Superior vena cava syndrome after pulsatile bidirectional Glenn shunt procedure: Perioperative implications

Directory of Open Access Journals (Sweden)

Neema Praveen

2009-01-01

Full Text Available Bidirectional superior cavopulmonary shunt (bidirectional Glenn shunt is generally performed in many congenital cardiac anomalies where complete two ventricle circulations cannot be easily achieved. The advantages of BDG shunt are achieved by partially separating the pulmonary and systemic venous circuits, and include reduced ventricular preload and long-term preservation of myocardium. The benefits of additional pulsatile pulmonary blood flow include the potential growth of pulmonary arteries, possible improvement in arterial oxygen saturation, and possible prevention of development of pulmonary arteriovenous malformations. However, increase in the systemic venous pressure after BDG with additional pulsatile blood flow is known. We describe the peri-operative implications of severe flow reversal in the superior vena cava after pulsatile BDG shunt construction in a child who presented for surgical interruption of the main pulmonary artery.

Coherent Detection for 1550 nm, 5 Gbit/s VCSEL Based 40 km Bidirectional PON Transmission

DEFF Research Database (Denmark)

Jensen, Jesper Bevensee; Rodes Lopez, Roberto; Zibar, Darko

2011-01-01

Coherent detection of directly modulated 1550nm VCSELs in 5Gbit/s bidirectional 40km SSMF PON-links is presented. Receiver sensitivity of –37.3dBm after transmission is achieved with 30dB system margin, corresponding to 1:1024 passive powersplitting.......Coherent detection of directly modulated 1550nm VCSELs in 5Gbit/s bidirectional 40km SSMF PON-links is presented. Receiver sensitivity of –37.3dBm after transmission is achieved with 30dB system margin, corresponding to 1:1024 passive powersplitting....

Bi-directional relationship between pregnancy and periodontal disease.

Science.gov (United States)

Armitage, Gary C

2013-02-01

During pregnancy profound perturbations in innate and adaptive immunity impact the clinical course of a number of infectious diseases, including those affecting periodontal tissues. Conversely, it has been suggested that periodontal infections may increase the risk of adverse pregnancy outcomes. In this review, a summary of the literature associated with the bidirectional relationship between pregnancy and periodontal disease as well as the possible mechanisms behind this interaction were examined. © 2013 John Wiley & Sons A/S.

Bi-directional vibration control of offshore wind turbines using a 3D pendulum tuned mass damper

Science.gov (United States)

Sun, C.; Jahangiri, V.

2018-05-01

Offshore wind turbines suffer from excessive bi-directional vibrations due to wind-wave misalignment and vortex induced vibrations. However, most of existing research focus on unidirectional vibration attenuation which is inadequate for real applications. The present paper proposes a three dimensional pendulum tuned mass damper (3d-PTMD) to mitigate the tower and nacelle dynamic response in the fore-aft and side-side directions. An analytical model of the wind turbine coupled with the 3d-PTMD is established wherein the interaction between the blades, the tower and the 3d-PTMD is modeled. Aerodynamic loading is computed using the Blade Element Momentum method where the Prandtls tip loss factor and the Glauert correction are considered. JONSWAP spectrum is adopted to generate wave data. Wave loading is computed using Morisons equation in collaboration with the strip theory. Via a numerical search approach, the design formula of the 3d-PTMD is obtained and examined on a National Renewable Energy Lab (NREL) monopile 5 MW baseline wind turbine model under misaligned wind, wave and seismic loading. Dual linear tuned mass dampers (TMDs) deployed in the fore-aft and side-side directions are utilized for comparison. It is found that the 3d-PTMD with a mass ratio of 2 % can improve the mitigation of the root mean square and peak response by around 10 % when compared with the dual linear TMDs in controlling the bi-directional vibration of the offshore wind turbines under misaligned wind, wave and seismic loading.

An Improved Multidimensional MPA Procedure for Bidirectional Earthquake Excitations

OpenAIRE

Wang, Feng; Sun, Jian-Gang; Zhang, Ning

2014-01-01

Presently, the modal pushover analysis procedure is extended to multidimensional analysis of structures subjected to multidimensional earthquake excitations. an improved multidimensional modal pushover analysis (IMMPA) method is presented in the paper in order to estimate the response demands of structures subjected to bidirectional earthquake excitations, in which the unidirectional earthquake excitation applied on equivalent SDOF system is replaced by the direct superposition of two compone...

Dynamic Correlations between Intrinsic Connectivity and Extrinsic Connectivity of the Auditory Cortex in Humans

Directory of Open Access Journals (Sweden)

Zhuang Cui

2017-08-01

Full Text Available The arrival of sound signals in the auditory cortex (AC triggers both local and inter-regional signal propagations over time up to hundreds of milliseconds and builds up both intrinsic functional connectivity (iFC and extrinsic functional connectivity (eFC of the AC. However, interactions between iFC and eFC are largely unknown. Using intracranial stereo-electroencephalographic recordings in people with drug-refractory epilepsy, this study mainly investigated the temporal dynamic of the relationships between iFC and eFC of the AC. The results showed that a Gaussian wideband-noise burst markedly elicited potentials in both the AC and numerous higher-order cortical regions outside the AC (non-auditory cortices. Granger causality analyses revealed that in the earlier time window, iFC of the AC was positively correlated with both eFC from the AC to the inferior temporal gyrus and that to the inferior parietal lobule. While in later periods, the iFC of the AC was positively correlated with eFC from the precentral gyrus to the AC and that from the insula to the AC. In conclusion, dual-directional interactions occur between iFC and eFC of the AC at different time windows following the sound stimulation and may form the foundation underlying various central auditory processes, including auditory sensory memory, object formation, integrations between sensory, perceptional, attentional, motor, emotional, and executive processes.

Does Intrinsic Habit Formation Actually Resolve the Equity Premium Puzzle?

OpenAIRE

David A. Chapman

2002-01-01

Constantinides (1990) describes a simple model of intrinsic habit formation that appears to resolve the "equity premium puzzle" of Mehra and Prescott (1985). This finding is particularly important, since it has motivated a broader consideration of the implications of habit formation preferences in dynamic equilibrium models. However, consumption growth actually behaves very differently pre- and post-1948, and the explanatory power of the habit formation model is driven by the pre-1948 data. U...

A bidirectional brain-machine interface featuring a neuromorphic hardware decoder

Directory of Open Access Journals (Sweden)

Fabio Boi

2016-12-01

Full Text Available Bidirectional brain-machine interfaces (BMIs establish a two-way direct communication link4 between the brain and the external world. A decoder translates recorded neural activity into motor5 commands and an encoder delivers sensory information collected from the environment directly6 to the brain creating a closed-loop system. These two modules are typically integrated in bulky7 external devices. However, the clinical support of patients with severe motor and sensory deficits8 requires compact, low-power, and fully implantable systems that can decode neural signals to9 control external devices. As a first step toward this goal, we developed a modular bidirectional BMI10 setup that uses a compact neuromorphic processor as a decoder. On this chip we implemented11 a network of spiking neurons built using its ultra-low-power mixed-signal analog/digital circuits.12 On-chip on-line spike-timing-dependent plasticity synapse circuits enabled the network to learn13 to decode neural signals recorded from the brain into motor outputs controlling the movements14 of an external device. The modularity of the BMI allowed us to tune the individual components15 of the setup without modifying the whole system. In this paper we present the features of16 this modular BMI, and describe how we configured the network of spiking neuron circuits to17 implement the decoder and to coordinate it with the encoder in an experimental BMI paradigm18 that connects bidirectionally the brain of an anesthetized rat with an external object. We show that19 the chip learned the decoding task correctly, allowing the interfaced brain to control the object’s20 trajectories robustly. Based on our demonstration, we propose that neuromorphic technology is21 mature enough for the development of BMI modules that are sufficiently low-power and compact,22 while being highly computationally powerful and adaptive.

A Bidirectional Brain-Machine Interface Featuring a Neuromorphic Hardware Decoder.

Science.gov (United States)

Boi, Fabio; Moraitis, Timoleon; De Feo, Vito; Diotalevi, Francesco; Bartolozzi, Chiara; Indiveri, Giacomo; Vato, Alessandro

2016-01-01

Bidirectional brain-machine interfaces (BMIs) establish a two-way direct communication link between the brain and the external world. A decoder translates recorded neural activity into motor commands and an encoder delivers sensory information collected from the environment directly to the brain creating a closed-loop system. These two modules are typically integrated in bulky external devices. However, the clinical support of patients with severe motor and sensory deficits requires compact, low-power, and fully implantable systems that can decode neural signals to control external devices. As a first step toward this goal, we developed a modular bidirectional BMI setup that uses a compact neuromorphic processor as a decoder. On this chip we implemented a network of spiking neurons built using its ultra-low-power mixed-signal analog/digital circuits. On-chip on-line spike-timing-dependent plasticity synapse circuits enabled the network to learn to decode neural signals recorded from the brain into motor outputs controlling the movements of an external device. The modularity of the BMI allowed us to tune the individual components of the setup without modifying the whole system. In this paper, we present the features of this modular BMI and describe how we configured the network of spiking neuron circuits to implement the decoder and to coordinate it with the encoder in an experimental BMI paradigm that connects bidirectionally the brain of an anesthetized rat with an external object. We show that the chip learned the decoding task correctly, allowing the interfaced brain to control the object's trajectories robustly. Based on our demonstration, we propose that neuromorphic technology is mature enough for the development of BMI modules that are sufficiently low-power and compact, while being highly computationally powerful and adaptive.

Gyrofluid Simulations of Intrinsic Rotation Generation in Reversed Shear Plasmas with Internal Transport Barriers

Science.gov (United States)

Jhang, Hogun; Kim, S. S.; Kwon, J. M.; Terzolo, L.; Kim, J. Y.; Diamond, P. H.

2010-11-01

It is accepted that the intrinsic rotation is generated via the residual stress, which is non-diffusive components of the turbulent Reynolds stress, without external momentum input. The physics leading to the onset of intrinsic rotation in L- and H- mode plasmas have been elucidated elsewhere. However, the physics responsible for the generation and transport of the intrinsic rotation and its relationship to the formation of internal transport barriers (ITBs) in reversed shear (RS) plasmas have not been explored in detail, which is the main subject in the present work. The revised version of the global gyrofluid code TRB is used for this study. It is found that the large intrinsic rotation (˜10-30% of the ion sound speed depending on ITB characteristics) is generated near the ITB region and propagates into the core. The intrinsic rotation increases linearly as the temperature gradient at ITB position increases, albeit not indefinitely. Key parameters related to the symmetry breaking, such as turbulent intensity and its gradient, the flux surface averaged parallel wavenumber are evaluated dynamically during the ITB formation. In particular, the role of reversed shear and the q-profile curvature is presented in relation to the symmetry breaking in RS plasmas.

Bidirectional fiber-wireless and fiber-IVLLC integrated system based on polarization-orthogonal modulation scheme.

Science.gov (United States)

Lu, Hai-Han; Li, Chung-Yi; Chen, Hwan-Wei; Ho, Chun-Ming; Cheng, Ming-Te; Huang, Sheng-Jhe; Yang, Zih-Yi; Lin, Xin-Yao

2016-07-25

A bidirectional fiber-wireless and fiber-invisible laser light communication (IVLLC) integrated system that employs polarization-orthogonal modulation scheme for hybrid cable television (CATV)/microwave (MW)/millimeter-wave (MMW)/baseband (BB) signal transmission is proposed and demonstrated. To our knowledge, it is the first one that adopts a polarization-orthogonal modulation scheme in a bidirectional fiber-wireless and fiber-IVLLC integrated system with hybrid CATV/MW/MMW/BB signal. For downlink transmission, carrier-to-noise ratio (CNR), composite second-order (CSO), composite triple-beat (CTB), and bit error rate (BER) perform well over 40-km single-mode fiber (SMF) and 10-m RF/50-m optical wireless transport scenarios. For uplink transmission, good BER performance is obtained over 40-km SMF and 50-m optical wireless transport scenario. Such a bidirectional fiber-wireless and fiber-IVLLC integrated system for hybrid CATV/MW/MMW/BB signal transmission will be an attractive alternative for providing broadband integrated services, including CATV, Internet, and telecommunication services. It is shown to be a prominent one to present the advancements for the convergence of fiber backbone and RF/optical wireless feeder.

Development of a bi-directional standing wave linear piezoelectric actuator with four driving feet.

Science.gov (United States)

Liu, Yingxiang; Shi, Shengjun; Li, Chunhong; Chen, Weishan; Wang, Liang; Liu, Junkao

2018-03-01

A bi-directional standing wave linear piezoelectric ultrasonic actuator with four driving feet is proposed in this work. Two sandwich type transducers operated in longitudinal-bending hybrid modes are set parallelly. The working mode of the transducer is not simple hybrid vibrations of a longitudinal one and a bending one, but a special coupling vibration mode contained both longitudinal and bending components. Two transducers with the same structure and unsymmetrical boundary conditions are set parallelly to accomplish the bi-directional driving: the first transducer can push the runner forward, while the other one produces the backward driving. In the experiments, two voltages with different amplitudes are applied on the two transducers, respectively: the one with higher voltage serves as the actuator, whereas the other one applied with lower voltage is used to reduce the frictional force. The prototype achieves maximum no-load speed and thrust force of 244 mm/s and 9.8 N. This work gives a new idea for the construction of standing wave piezoelectric ultrasonic actuator with bi-directional driving ability. Copyright © 2017 Elsevier B.V. All rights reserved.

Bidirectional Relations between Temperament and Parenting Styles in Chinese Children

Science.gov (United States)

Lee, Erica H.; Zhou, Qing; Eisenberg, Nancy; Wang, Yun

2012-01-01

The present study examined bidirectional relations between child temperament and parenting styles in a sample (n = 425) of Chinese children during elementary school period (age range = 6 to 9 years at Wave 1). Using two waves (3.8 years apart) of longitudinal data, we tested two hypotheses: (1) whether child temperament (effortful control and anger/frustration) at Wave 1 predicts parenting styles (authoritative and authoritarian parenting) at Wave 2, controlling for Wave 1 parenting; and (2) whether parenting styles at Wave 1 predict Wave 2 temperament, controlling for Wave 1 temperament. We found support for bidirectional relations between temperament and authoritarian parenting, such that higher effortful control and lower anger/frustration were associated with higher authoritarian parenting across time and in both directions. There were no significant cross-time associations between children’s temperament and authoritative parenting. These findings extend the previous tests of transactional relations between child temperament and parenting in Chinese children and are consistent with the cultural values toward effortful control and control of anger/frustration in Chinese society. PMID:23482684

Bidirectional Relations between Temperament and Parenting Styles in Chinese Children.

Science.gov (United States)

Lee, Erica H; Zhou, Qing; Eisenberg, Nancy; Wang, Yun

2013-01-01

The present study examined bidirectional relations between child temperament and parenting styles in a sample ( n = 425) of Chinese children during elementary school period (age range = 6 to 9 years at Wave 1). Using two waves (3.8 years apart) of longitudinal data, we tested two hypotheses: (1) whether child temperament (effortful control and anger/frustration) at Wave 1 predicts parenting styles (authoritative and authoritarian parenting) at Wave 2, controlling for Wave 1 parenting; and (2) whether parenting styles at Wave 1 predict Wave 2 temperament, controlling for Wave 1 temperament. We found support for bidirectional relations between temperament and authoritarian parenting, such that higher effortful control and lower anger/frustration were associated with higher authoritarian parenting across time and in both directions. There were no significant cross-time associations between children's temperament and authoritative parenting. These findings extend the previous tests of transactional relations between child temperament and parenting in Chinese children and are consistent with the cultural values toward effortful control and control of anger/frustration in Chinese society.

Hormone response to bidirectional selection on social behavior.

Science.gov (United States)

Amdam, Gro V; Page, Robert E; Fondrk, M Kim; Brent, Colin S

2010-01-01

Behavior is a quantitative trait determined by multiple genes. Some of these genes may have effects from early development and onward by influencing hormonal systems that are active during different life-stages leading to complex associations, or suites, of traits. Honey bees (Apis mellifera) have been used extensively in experiments on the genetic and hormonal control of complex social behavior, but the relationships between their early developmental processes and adult behavioral variation are not well understood. Bidirectional selective breeding on social food-storage behavior produced two honey bee strains, each with several sublines, that differ in an associated suite of anatomical, physiological, and behavioral traits found in unselected wild type bees. Using these genotypes, we document strain-specific changes during larval, pupal, and early adult life-stages for the central insect hormones juvenile hormone (JH) and ecdysteroids. Strain differences correlate with variation in female reproductive anatomy (ovary size), which can be influenced by JH during development, and with secretion rates of ecdysteroid from the ovaries of adults. Ovary size was previously assigned to the suite of traits of honey bee food-storage behavior. Our findings support that bidirectional selection on honey bee social behavior acted on pleiotropic gene networks. These networks may bias a bee's adult phenotype by endocrine effects on early developmental processes that regulate variation in reproductive traits. © 2010 Wiley Periodicals, Inc.

Microsecond molecular dynamics simulations of intrinsically disordered proteins involved in the oxidative stress response

NARCIS (Netherlands)

Cino, E.A.; Wong-ekkabut, J.; Karttunen, M.E.J.; Choy, W.-Y.

2011-01-01

Intrinsically disordered proteins (IDPs) are abundant in cells and have central roles in protein-protein interaction networks. Interactions between the IDP Prothymosin alpha (ProTa) and the Neh2 domain of Nuclear factor erythroid 2-related factor 2 (Nrf2), with a common binding partner, Kelch-like

Color coded multiple access scheme for bidirectional multiuser visible light communications in smart home technologies

Science.gov (United States)

Tiwari, Samrat Vikramaditya; Sewaiwar, Atul; Chung, Yeon-Ho

2015-10-01

In optical wireless communications, multiple channel transmission is an attractive solution to enhancing capacity and system performance. A new modulation scheme called color coded multiple access (CCMA) for bidirectional multiuser visible light communications (VLC) is presented for smart home applications. The proposed scheme uses red, green and blue (RGB) light emitting diodes (LED) for downlink and phosphor based white LED (P-LED) for uplink to establish a bidirectional VLC and also employs orthogonal codes to support multiple users and devices. The downlink transmission for data user devices and smart home devices is provided using red and green colors from the RGB LEDs, respectively, while uplink transmission from both types of devices is performed using the blue color from P-LEDs. Simulations are conducted to verify the performance of the proposed scheme. It is found that the proposed bidirectional multiuser scheme is efficient in terms of data rate and performance. In addition, since the proposed scheme uses RGB signals for downlink data transmission, it provides flicker-free illumination that would lend itself to multiuser VLC system for smart home applications.

Robust state estimation for uncertain fuzzy bidirectional associative memory networks with time-varying delays

Science.gov (United States)

Vadivel, P.; Sakthivel, R.; Mathiyalagan, K.; Arunkumar, A.

2013-09-01

This paper addresses the issue of robust state estimation for a class of fuzzy bidirectional associative memory (BAM) neural networks with time-varying delays and parameter uncertainties. By constructing the Lyapunov-Krasovskii functional, which contains the triple-integral term and using the free-weighting matrix technique, a set of sufficient conditions are derived in terms of linear matrix inequalities (LMIs) to estimate the neuron states through available output measurements such that the dynamics of the estimation error system is robustly asymptotically stable. In particular, we consider a generalized activation function in which the traditional assumptions on the boundedness, monotony and differentiability of the activation functions are removed. More precisely, the design of the state estimator for such BAM neural networks can be obtained by solving some LMIs, which are dependent on the size of the time derivative of the time-varying delays. Finally, a numerical example with simulation result is given to illustrate the obtained theoretical results.

Robust state estimation for uncertain fuzzy bidirectional associative memory networks with time-varying delays

International Nuclear Information System (INIS)

Vadivel, P; Sakthivel, R; Mathiyalagan, K; Arunkumar, A

2013-01-01

This paper addresses the issue of robust state estimation for a class of fuzzy bidirectional associative memory (BAM) neural networks with time-varying delays and parameter uncertainties. By constructing the Lyapunov–Krasovskii functional, which contains the triple-integral term and using the free-weighting matrix technique, a set of sufficient conditions are derived in terms of linear matrix inequalities (LMIs) to estimate the neuron states through available output measurements such that the dynamics of the estimation error system is robustly asymptotically stable. In particular, we consider a generalized activation function in which the traditional assumptions on the boundedness, monotony and differentiability of the activation functions are removed. More precisely, the design of the state estimator for such BAM neural networks can be obtained by solving some LMIs, which are dependent on the size of the time derivative of the time-varying delays. Finally, a numerical example with simulation result is given to illustrate the obtained theoretical results. (paper)

Distributed fiber Raman amplification in long reach PON bidirectional access links

DEFF Research Database (Denmark)

Tafur Monroy, Idelfonso; Kjær, Rasmus; Öhman, Filip

2008-01-01

Distributed Raman fiber amplification is proposed and experimentally demonstrated to support long reach passive optical network (PON) links. An 80 km, bidirectional, single fiber link is demonstrated using both standard intensity optical modulators at 10 Gb/s and up to 7.5 Gb/s using novel...

Comparative evaluation of soft-switching, bidirectional, isolated AC/DC converter topologies

NARCIS (Netherlands)

Everts, J.; Krismer, F.; Van den Keybus, J.; Driesen, Johan; Kolar, J.W.

2012-01-01

For realizing bidirectional and isolated AC/DC converters, soft-switching techniques/topologies seem to be a favourable choice as they enable a further loss and volume reduction of the system. Contrary to the traditional dual-stage approach, using a power factor corrector (PFC) stage in series with

Do sensitive parents foster kind children, or vice versa? Bidirectional influences between children's prosocial behavior and parental sensitivity.

Science.gov (United States)

Newton, Emily K; Laible, Deborah; Carlo, Gustavo; Steele, Joel S; McGinley, Meredith

2014-06-01

Bidirectional theories of social development have been around for over 40 years (Bell, 1968), yet they have been applied primarily to the study of antisocial development. In the present study, the reciprocal relationship between parenting behavior and children's socially competent behaviors were examined. Using the National Institute of Child Health and Development Study of Early Child Care data set (NICHD Early Child Care Research Network, 2005), bidirectional relationships between parental sensitivity and children's prosocial behavior were modeled using latent variables in structural equation modeling for mothers and fathers, separately. Children and their parents engaged in structured interactions when children were 54-month-olds, 3rd graders, and 5th graders, and these interactions were coded for parental sensitivity. At 3rd, 5th, and 6th grades, teachers and parents reported on children's prosocial behavior. Parental education and child gender were entered as covariates in the models. The results provide support for a bidirectional relationship between children's prosocial behavior and maternal sensitivity (but not paternal sensitivity) in middle childhood. The importance of using a bidirectional approach to examine the development of social competence is emphasized. PsycINFO Database Record (c) 2014 APA, all rights reserved.

A Novel User Created Message Application Service Design for Bidirectional TPEG

Science.gov (United States)

Lee, Sang-Hee; Jo, Kang-Hyun

The T-DMB (Terrestrial-Digital Multimedia Broadcasting) is the national service, currently successful in use in Korea since 2008. Among other services, TPEG (Transport Protocol Experts Group) service has been spotlighted in the aspects of creating earnings. At present, TPEG service is not so popular as it fails to satisfy the user’s demands on various aspects. Thus, the variety of services including bidirectional service is necessary in stage of DMB2.0. In this paper, the limitations of existing TPEG-POI (Point of Interest) application service using the wireless communication network are indicated. To overcome such limitations, we propose a business model for TPEG-UCM (User Created Message) application service which uses individual bidirectional media. The experiment shown in this paper proves the usability and operability of the proposed method, suggesting that the implementation of the proposed method would be overcome a lack of variety and unidirectional of existing TPEG application.

Bidirectional neural interface: Closed-loop feedback control for hybrid neural systems.

Science.gov (United States)

Chou, Zane; Lim, Jeffrey; Brown, Sophie; Keller, Melissa; Bugbee, Joseph; Broccard, Frédéric D; Khraiche, Massoud L; Silva, Gabriel A; Cauwenberghs, Gert

2015-01-01

Closed-loop neural prostheses enable bidirectional communication between the biological and artificial components of a hybrid system. However, a major challenge in this field is the limited understanding of how these components, the two separate neural networks, interact with each other. In this paper, we propose an in vitro model of a closed-loop system that allows for easy experimental testing and modification of both biological and artificial network parameters. The interface closes the system loop in real time by stimulating each network based on recorded activity of the other network, within preset parameters. As a proof of concept we demonstrate that the bidirectional interface is able to establish and control network properties, such as synchrony, in a hybrid system of two neural networks more significantly more effectively than the same system without the interface or with unidirectional alternatives. This success holds promise for the application of closed-loop systems in neural prostheses, brain-machine interfaces, and drug testing.

A bidirectional association between cognitive ability in young adulthood and epilepsy

DEFF Research Database (Denmark)

Osler, Merete; Mortensen, Erik L; Christensen, Kaare

2018-01-01

Aim: To investigate the bidirectional association between cognitive ability in young adulthood and epilepsy. Methods: This cohort study included 1 159 076 men enrolled in the mandatory conscription board examination from the Danish Conscription Database (DCD; 658 465 men examined 1957-84), the Da......Aim: To investigate the bidirectional association between cognitive ability in young adulthood and epilepsy. Methods: This cohort study included 1 159 076 men enrolled in the mandatory conscription board examination from the Danish Conscription Database (DCD; 658 465 men examined 1957...... with epilepsy before conscription, and they had about 0.25 standard deviation (SD) lower cognitive scores than men without epilepsy. The largest difference in cognition was seen for those with the largest number of hospital contacts. A total of 22 364 (1.9%) men developed epilepsy, and cognitive ability......: The cognitive impairment seen in adults with epilepsy seems to reflect combined effects of epileptic processes and lower premorbid cognitive ability....

Reconstructed phase spaces of intrinsic mode functions. Application to postural stability analysis.

Science.gov (United States)

Snoussi, Hichem; Amoud, Hassan; Doussot, Michel; Hewson, David; Duchêne, Jacques

2006-01-01

In this contribution, we propose an efficient nonlinear analysis method characterizing postural steadiness. The analyzed signal is the displacement of the centre of pressure (COP) collected from a force plate used for measuring postural sway. The proposed method consists of analyzing the nonlinear dynamics of the intrinsic mode functions (IMF) of the COP signal. The nonlinear properties are assessed through the reconstructed phase spaces of the different IMFs. This study shows some specific geometries of the attractors of some intrinsic modes. Moreover, the volume spanned by the geometric attractors in the reconstructed phase space represents an efficient indicator of the postural stability of the subject. Experiments results corroborate the effectiveness of the method to blindly discriminate young subjects, elderly subjects and subjects presenting a risk of falling.

pth moment exponential stability of stochastic memristor-based bidirectional associative memory (BAM) neural networks with time delays.

Science.gov (United States)

Wang, Fen; Chen, Yuanlong; Liu, Meichun

2018-02-01

Stochastic memristor-based bidirectional associative memory (BAM) neural networks with time delays play an increasingly important role in the design and implementation of neural network systems. Under the framework of Filippov solutions, the issues of the pth moment exponential stability of stochastic memristor-based BAM neural networks are investigated. By using the stochastic stability theory, Itô's differential formula and Young inequality, the criteria are derived. Meanwhile, with Lyapunov approach and Cauchy-Schwarz inequality, we derive some sufficient conditions for the mean square exponential stability of the above systems. The obtained results improve and extend previous works on memristor-based or usual neural networks dynamical systems. Four numerical examples are provided to illustrate the effectiveness of the proposed results. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sliding Mode Control of a Bidirectional Buck/Boost DC-DC Converter with Constant Switching Frequency

Directory of Open Access Journals (Sweden)

A. Safari

2018-03-01

Full Text Available In this paper, sliding mode control (SMC for a bidirectional buck/boost DC-DC converter (BDC with constant frequency in continuous conduction mode (CCM is discussed. Since the converter is a high-order converter, the reduced-order sliding manifold is exploited. Because of right-half-plan zero (RHPZ in the converter’s duty ratio to output voltage transfer function, sliding mode current controller is used. This controller benefits from various advantages such as fast dynamic response, robustness, stable and small variation of the settling time over a wide range of operation conditions. Because the converter operates in both step-down and step-up modes, two sliding manifold is derived for each mode. The existence and stability conditions are analyzed for both SMC in step-down and step-up modes. Finally, Simulation results are also provided to justify the feasibility of the controller using MATLAB/Simulink.

Aplikasi Bidirectional Assosiatif Memori (BAM) Network pada Pengenalan Model

OpenAIRE

Iskandar, Iskhaq

2001-01-01

Penelitian ini bertujuan untuk menyusun suatu simulasi komputer yang dapat dipergunakan untuk menguji kemampuan memori komputer dalam mengenali suatu model tertentu berdasarkan algoritma Bidirectional Assosiatif Memori Neural Network. Model yang digunakan dalam penelitian dalam penelitian ini adalah huruf-huruf abjad yang dinyatakan dalam kode polar –1 dan +1 dalam bentuk matrik [5x3]. Hasil yang didapat dalam penelitian ini menunjukkan bahwa rancangan network yang disusun mampu mengenali mod...

Predistortion of a Bidirectional Cuk Audio Amplifier

DEFF Research Database (Denmark)

Birch, Thomas Hagen; Nielsen, Dennis; Knott, Arnold

2014-01-01

Some non-linear amplifier topologies are capable of providing a larger voltage gain than one from a DC source, which could make them suitable for various applications. However, the non-linearities introduce a significant amount of harmonic distortion (THD). Some of this distortion could be reduced...... using predistortion. This paper suggests linearizing a nonlinear bidirectional Cuk audio amplifier using an analog predistortion approach. A prototype power stage was built and results show that a voltage gain of up to 9 dB and reduction in THD from 6% down to 3% was obtainable using this approach....

Multistability in bidirectional associative memory neural networks

International Nuclear Information System (INIS)

Huang Gan; Cao Jinde

2008-01-01

In this Letter, the multistability issue is studied for Bidirectional Associative Memory (BAM) neural networks. Based on the existence and stability analysis of the neural networks with or without delay, it is found that the 2n-dimensional networks can have 3 n equilibria and 2 n equilibria of them are locally exponentially stable, where each layer of the BAM network has n neurons. Furthermore, the results has been extended to (n+m)-dimensional BAM neural networks, where there are n and m neurons on the two layers respectively. Finally, two numerical examples are presented to illustrate the validity of our results

Multistability in bidirectional associative memory neural networks

Science.gov (United States)

Huang, Gan; Cao, Jinde

2008-04-01

In this Letter, the multistability issue is studied for Bidirectional Associative Memory (BAM) neural networks. Based on the existence and stability analysis of the neural networks with or without delay, it is found that the 2 n-dimensional networks can have 3 equilibria and 2 equilibria of them are locally exponentially stable, where each layer of the BAM network has n neurons. Furthermore, the results has been extended to (n+m)-dimensional BAM neural networks, where there are n and m neurons on the two layers respectively. Finally, two numerical examples are presented to illustrate the validity of our results.

Intrinsic non-inductive current driven by ETG turbulence in tokamaks

Science.gov (United States)

Singh, Rameswar; Kaw, P. K.; Singh, R.; Gürcan, Ã.-. D.

2017-10-01

Motivated by observations and physics understanding of the phenomenon of intrinsic rotation, it is suggested that similar considerations for electron dynamics may result in intrinsic current in tokamaks. We have investigated the possibility of intrinsic non-inductive current in the turbulent plasma of tokamaks. Ohm's law is generalized to include the effect of turbulent fluctuations in the mean field approach. This clearly leads to the identification of sources and the mechanisms of non-inductive current drive by electron temperature gradient turbulence. It is found that a mean parallel electro-motive force and hence a mean parallel current can be generated by (1) the divergence of residual current flux density and (2) a non-flux like turbulent source from the density and parallel electric field correlations. Both residual flux and the non-flux source require parallel wave-number k∥ symmetry breaking for their survival which can be supplied by various means like mean E × B shear, turbulence intensity gradient, etc. Estimates of turbulence driven current are compared with the background bootstrap current in the pedestal region. It is found that turbulence driven current is nearly 10% of the bootstrap current and hence can have a significant influence on the equilibrium current density profiles and current shear driven modes.

Intrinsic Chevrolets at the SSC

International Nuclear Information System (INIS)

Brodsky, S.J.; Collins, J.C.; Ellis, S.D.; Gunion, J.F.; Mueller, A.H.

1984-01-01

The possibility of the production at high energy of heavy quarks, supersymmetric particles and other large mass colored systems via the intrinsic twist-six components in the proton wave function is discussed. While the existing data do not rule out the possible relevance of intrinsic charm production at present energies, the extrapolation of such intrinsic contributions to very high masses and energies suggests that they will not play an important role at the SSC

Multi-user bidirectional communication using isochronal synchronisation of array of chaotic directly modulated semiconductor lasers

International Nuclear Information System (INIS)

Krishna, Bindu M.; John, Manu P.; Nandakumaran, V.M.

2010-01-01

Isochronal synchronisation between the elements of an array of three mutually coupled directly modulated semiconductor lasers is utilized for the purpose of simultaneous bidirectional secure communication. Chaotic synchronisation is achieved by adding the coupling signal to the self feedback signal provided to each element of the array. A symmetric coupling is effective in inducing synchronisation between the elements of the array. This coupling scheme provides a direct link between every pair of elements thus making the method suitable for simultaneous bidirectional communication between them. Both analog and digital messages are successfully encrypted and decrypted simultaneously by each element of the array.

Efficient parallel and out of core algorithms for constructing large bi-directed de Bruijn graphs

Directory of Open Access Journals (Sweden)

Vaughn Matthew

2010-11-01

Full Text Available Abstract Background Assembling genomic sequences from a set of overlapping reads is one of the most fundamental problems in computational biology. Algorithms addressing the assembly problem fall into two broad categories - based on the data structures which they employ. The first class uses an overlap/string graph and the second type uses a de Bruijn graph. However with the recent advances in short read sequencing technology, de Bruijn graph based algorithms seem to play a vital role in practice. Efficient algorithms for building these massive de Bruijn graphs are very essential in large sequencing projects based on short reads. In an earlier work, an O(n/p time parallel algorithm has been given for this problem. Here n is the size of the input and p is the number of processors. This algorithm enumerates all possible bi-directed edges which can overlap with a node and ends up generating Θ(nΣ messages (Σ being the size of the alphabet. Results In this paper we present a Θ(n/p time parallel algorithm with a communication complexity that is equal to that of parallel sorting and is not sensitive to Σ. The generality of our algorithm makes it very easy to extend it even to the out-of-core model and in this case it has an optimal I/O complexity of Θ(nlog(n/BBlog(M/B (M being the main memory size and B being the size of the disk block. We demonstrate the scalability of our parallel algorithm on a SGI/Altix computer. A comparison of our algorithm with the previous approaches reveals that our algorithm is faster - both asymptotically and practically. We demonstrate the scalability of our sequential out-of-core algorithm by comparing it with the algorithm used by VELVET to build the bi-directed de Bruijn graph. Our experiments reveal that our algorithm can build the graph with a constant amount of memory, which clearly outperforms VELVET. We also provide efficient algorithms for the bi-directed chain compaction problem. Conclusions The bi-directed

Efficient parallel and out of core algorithms for constructing large bi-directed de Bruijn graphs.

Science.gov (United States)

Kundeti, Vamsi K; Rajasekaran, Sanguthevar; Dinh, Hieu; Vaughn, Matthew; Thapar, Vishal

2010-11-15

Assembling genomic sequences from a set of overlapping reads is one of the most fundamental problems in computational biology. Algorithms addressing the assembly problem fall into two broad categories - based on the data structures which they employ. The first class uses an overlap/string graph and the second type uses a de Bruijn graph. However with the recent advances in short read sequencing technology, de Bruijn graph based algorithms seem to play a vital role in practice. Efficient algorithms for building these massive de Bruijn graphs are very essential in large sequencing projects based on short reads. In an earlier work, an O(n/p) time parallel algorithm has been given for this problem. Here n is the size of the input and p is the number of processors. This algorithm enumerates all possible bi-directed edges which can overlap with a node and ends up generating Θ(nΣ) messages (Σ being the size of the alphabet). In this paper we present a Θ(n/p) time parallel algorithm with a communication complexity that is equal to that of parallel sorting and is not sensitive to Σ. The generality of our algorithm makes it very easy to extend it even to the out-of-core model and in this case it has an optimal I/O complexity of Θ(nlog(n/B)Blog(M/B)) (M being the main memory size and B being the size of the disk block). We demonstrate the scalability of our parallel algorithm on a SGI/Altix computer. A comparison of our algorithm with the previous approaches reveals that our algorithm is faster--both asymptotically and practically. We demonstrate the scalability of our sequential out-of-core algorithm by comparing it with the algorithm used by VELVET to build the bi-directed de Bruijn graph. Our experiments reveal that our algorithm can build the graph with a constant amount of memory, which clearly outperforms VELVET. We also provide efficient algorithms for the bi-directed chain compaction problem. The bi-directed de Bruijn graph is a fundamental data structure for

Partner Effects and Bi-Directional Parent-Child Effects in Family Alcohol Use

NARCIS (Netherlands)

Otten, R.; van der Zwaluw, C.S.; Vorst, H.; Engels, R.C.M.E.

2008-01-01

Introduction: The current study investigated partner effects and bidirectional parent-child effects in family alcohol use. Methods: A full family, longitudinal design was used to test the hypotheses. Participants were 428 families, including mothers, fathers, and 2 children. Associations were

Intrinsic and extrinsic drivers of source-sink dynamics

Science.gov (United States)

1. Many factors affect the presence and exchange of individuals among subpopulations and influence not only the emergence, but the strength of ensuing source-sink dynamics within metapopulations, yet their relative contributions remain largely unexplored. 2. To help identify the...

Intrinsic work function of molecular films

International Nuclear Information System (INIS)

Ivančo, Ján

2012-01-01

The electronic properties of molecular films are analysed with the consideration of the molecular orientation. The study demonstrates that surfaces of electroactive oligomeric molecular films can be classified—analogously to the elemental surfaces—by their intrinsic work functions. The intrinsic work function of molecular films is correlated with their ionisation energies; again, the behaviour is analogous to the correlation existing between the first ionisation energy of elements and the work function of the corresponding elemental surfaces. The proposed intrinsic work-function concept suggests that the mechanism for the energy-level alignment at the interfaces associated with molecular films is virtually controlled by work functions of materials brought into the contact. - Highlights: ► Molecular films exhibit their own (intrinsic) work function. ► Intrinsic work function is correlated with ionisation energy of molecular films. ► Intrinsic work function determines dipole at interface with a particular surface. ► Surface vacuum-level change upon film growth does not relate to interfacial dipole.

Helical solutions of the bidirectional vortex in a cylindrical cyclone: Beltramian and Trkalian motions

International Nuclear Information System (INIS)

Majdalani, Joseph

2012-01-01

In this work, two families of helical motions are investigated as prospective candidates for describing the bidirectional vortex field in a right-cylindrical chamber. These basic solutions are relevant to cyclone separators and to idealized representations of vortex-fired liquid and hybrid rocket engines in which bidirectional vortex motion is established. To begin, the bulk fluid motion is taken to be isentropic along streamlines, with no concern for reactions, heat transfer, viscosity, compressibility or unsteadiness. Then using the Bragg–Hawthorne equation for steady, inviscid, axisymmetric motion, two families of Euler solutions are derived. Among the characteristics of the newly developed solutions one may note the axial dependence of the swirl velocity, the Trkalian and Beltramian types of the helical motions, the sensitivity of the solutions to the outlet radius, the alternate locations of the mantle, and the increased axial and radial velocity magnitudes, including the rate of mass transfer across the mantle, for which explicit approximations are obtained. Our results are compared to an existing, complex lamellar model of the bidirectional vortex in which the swirl velocity reduces to a free vortex. In this vein, we find the strictly Beltramian flows to share virtually identical pressure variations and radial pressure gradients with those associated with the complex lamellar motion. Furthermore, both families warrant an asymptotic treatment to overcome their endpoint limitations caused by their omission of viscous stresses. From a broader perspective, the work delineates a logical framework through which self-similar, axisymmetric solutions to bidirectional and multidirectional vortex motions may be pursued. It also illustrates the manner through which different formulations may be arrived at depending on the types of wall boundary conditions. For example, both the slip condition at the sidewall and the inlet flow pattern at the headwall may be enforced

Helical solutions of the bidirectional vortex in a cylindrical cyclone: Beltramian and Trkalian motions

Energy Technology Data Exchange (ETDEWEB)

Majdalani, Joseph, E-mail: joe.majdalani@gmail.com [Department of Mechanical, Aerospace and Biomedical Engineering, University of Tennessee Space Institute (UTSI), 411 B. H. Goethert Parkway, Tullahoma, TN 37388 (United States)

2012-10-15

In this work, two families of helical motions are investigated as prospective candidates for describing the bidirectional vortex field in a right-cylindrical chamber. These basic solutions are relevant to cyclone separators and to idealized representations of vortex-fired liquid and hybrid rocket engines in which bidirectional vortex motion is established. To begin, the bulk fluid motion is taken to be isentropic along streamlines, with no concern for reactions, heat transfer, viscosity, compressibility or unsteadiness. Then using the Bragg-Hawthorne equation for steady, inviscid, axisymmetric motion, two families of Euler solutions are derived. Among the characteristics of the newly developed solutions one may note the axial dependence of the swirl velocity, the Trkalian and Beltramian types of the helical motions, the sensitivity of the solutions to the outlet radius, the alternate locations of the mantle, and the increased axial and radial velocity magnitudes, including the rate of mass transfer across the mantle, for which explicit approximations are obtained. Our results are compared to an existing, complex lamellar model of the bidirectional vortex in which the swirl velocity reduces to a free vortex. In this vein, we find the strictly Beltramian flows to share virtually identical pressure variations and radial pressure gradients with those associated with the complex lamellar motion. Furthermore, both families warrant an asymptotic treatment to overcome their endpoint limitations caused by their omission of viscous stresses. From a broader perspective, the work delineates a logical framework through which self-similar, axisymmetric solutions to bidirectional and multidirectional vortex motions may be pursued. It also illustrates the manner through which different formulations may be arrived at depending on the types of wall boundary conditions. For example, both the slip condition at the sidewall and the inlet flow pattern at the headwall may be enforced or

An Improved Multidimensional MPA Procedure for Bidirectional Earthquake Excitations

Directory of Open Access Journals (Sweden)

Feng Wang

2014-01-01

Full Text Available Presently, the modal pushover analysis procedure is extended to multidimensional analysis of structures subjected to multidimensional earthquake excitations. an improved multidimensional modal pushover analysis (IMMPA method is presented in the paper in order to estimate the response demands of structures subjected to bidirectional earthquake excitations, in which the unidirectional earthquake excitation applied on equivalent SDOF system is replaced by the direct superposition of two components earthquake excitations, and independent analysis in each direction is not required and the application of simplified superposition formulas is avoided. The strength reduction factor spectra based on superposition of earthquake excitations are discussed and compared with the traditional strength reduction factor spectra. The step-by-step procedure is proposed to estimate seismic demands of structures. Two examples are implemented to verify the accuracy of the method, and the results of the examples show that (1 the IMMPA method can be used to estimate the responses of structure subjected to bidirectional earthquake excitations. (2 Along with increase of peak of earthquake acceleration, structural response deviation estimated with the IMMPA method may also increase. (3 Along with increase of the number of total floors of structures, structural response deviation estimated with the IMMPA method may also increase.

The Chaotic-Based Control of Three-Port Isolated Bidirectional DC/DC Converters for Electric and Hybrid Vehicles

Directory of Open Access Journals (Sweden)

Zheng Wang

2016-01-01

Full Text Available Three-port isolated (TPI bidirectional DC/DC converters have three energy ports and offer advantages of large voltage gain, galvanic isolation ability and high power density. For this reason this kind of converters are suitable to connect different energy sources and loads in electric and hybrid vehicles. The purpose of this paper is to propose chaotic modulation and the related control scheme for TPI bidirectional DC/DC converters, in such a way that the switching harmonic peaks can be suppressed in spectrum and the conducted electromagnetic interference (EMI is reduced. Two chaotic modulation strategies, namely the continuously chaotic modulation and the discretely chaotic modulation are presented. These two chaotic modulation strategies are applied for TPI bidirectional DC/DC converters with shifted-phase angle based control and phase-shifted PWM control. Both simulation and experiments are given to verify the validity of the proposed chaotic modulation-based control schemes.

Mechanical analysis of non-uniform bi-directional functionally graded intelligent micro-beams using modified couple stress theory

Science.gov (United States)

Bakhshi Khaniki, Hossein; Rajasekaran, Sundaramoorthy

2018-05-01

This study develops a comprehensive investigation on mechanical behavior of non-uniform bi-directional functionally graded beam sensors in the framework of modified couple stress theory. Material variation is modelled through both length and thickness directions using power-law, sigmoid and exponential functions. Moreover, beam is assumed with linear, exponential and parabolic cross-section variation through the length using power-law and sigmoid varying functions. Using these assumptions, a general model for microbeams is presented and formulated by employing Hamilton’s principle. Governing equations are solved using a mixed finite element method with Lagrangian interpolation technique, Gaussian quadrature method and Wilson’s Lagrangian multiplier method. It is shown that by using bi-directional functionally graded materials in nonuniform microbeams, mechanical behavior of such structures could be affected noticeably and scale parameter has a significant effect in changing the rigidity of nonuniform bi-directional functionally graded beams.

Bidirectional Partner Violence among Homeless Young Adults: Risk Factors and Outcomes

Science.gov (United States)

Tyler, Kimberly A.; Melander, Lisa A.; Noel, HarmoniJoie

2009-01-01

One of the most prevalent forms of violence in contemporary society is the victimization of intimate partners. Although it has been established that homeless young people experience high levels of victimization on the street, little is known about partner violence (PV) experiences among this group, especially bidirectional violence. As such, the…

High performance bidirectional electrostatic inchworm motor fabricated by trench isolation technology

NARCIS (Netherlands)

Sarajlic, Edin; Berenschot, Johan W.; Tas, Niels Roelof; Fujita, H.; Krijnen, Gijsbertus J.M.; Elwenspoek, Michael Curt

We report on an electrostatic linear micromotor, which employs built-in mechanical leverage to convert normal deflection of a flexible plate into a small in-plane step and two clamps to enable bidirectional inchworm motion. The motor, measuring 412 /spl mu/m /spl times/ 286 /spl mu/m, is fabricated

Hopf bifurcation of an (n + 1) -neuron bidirectional associative memory neural network model with delays.

Science.gov (United States)

Xiao, Min; Zheng, Wei Xing; Cao, Jinde

2013-01-01

Recent studies on Hopf bifurcations of neural networks with delays are confined to simplified neural network models consisting of only two, three, four, five, or six neurons. It is well known that neural networks are complex and large-scale nonlinear dynamical systems, so the dynamics of the delayed neural networks are very rich and complicated. Although discussing the dynamics of networks with a few neurons may help us to understand large-scale networks, there are inevitably some complicated problems that may be overlooked if simplified networks are carried over to large-scale networks. In this paper, a general delayed bidirectional associative memory neural network model with n + 1 neurons is considered. By analyzing the associated characteristic equation, the local stability of the trivial steady state is examined, and then the existence of the Hopf bifurcation at the trivial steady state is established. By applying the normal form theory and the center manifold reduction, explicit formulae are derived to determine the direction and stability of the bifurcating periodic solution. Furthermore, the paper highlights situations where the Hopf bifurcations are particularly critical, in the sense that the amplitude and the period of oscillations are very sensitive to errors due to tolerances in the implementation of neuron interconnections. It is shown that the sensitivity is crucially dependent on the delay and also significantly influenced by the feature of the number of neurons. Numerical simulations are carried out to illustrate the main results.

Bidirectional reflectance distribution function measurements and analysis of retroreflective materials.

Science.gov (United States)

Belcour, Laurent; Pacanowski, Romain; Delahaie, Marion; Laville-Geay, Aude; Eupherte, Laure

2014-12-01

We compare the performance of various analytical retroreflecting bidirectional reflectance distribution function (BRDF) models to assess how they reproduce accurately measured data of retroreflecting materials. We introduce a new parametrization, the back vector parametrization, to analyze retroreflecting data, and we show that this parametrization better preserves the isotropy of data. Furthermore, we update existing BRDF models to improve the representation of retroreflective data.

Effect of solvent-controlled aggregation on the intrinsic emission properties of PAMAM dendrimers

International Nuclear Information System (INIS)

Jasmine, Maria J.; Kavitha, Manniledam; Prasad, Edamana

2009-01-01

Solvent-induced aggregation and its effect on the intrinsic emission properties of amine, hydroxy and carboxylate terminated, poly(amidoamine) (PAMAM) dendrimers have been investigated in glycerol, ethylene glycol, methanol, ethylene diamine and water. Altering the solvent medium induces remarkable changes in the intrinsic emission properties of the PAMAM dendrimers at identical concentration. Upon excitation at 370 nm, amine terminated PAMAM dendrimer exhibits an intense emission at 470 nm in glycerol, ethylene glycol as well as glycerol-water mixtures. Conversely, weak luminescence is observed for hydroxy and carboxylate terminated PAMAM dendrimers in the same solvent systems. When the solvent is changed to ethylene diamine, hydroxy terminated PAMAM exhibits intense blue emission at 425 nm. While the emission intensity is varied when the solvent milieu is changed, excited state lifetime values of PAMAM dendrimers remain independent of the solvent used. UV-visible absorption and dynamic light scattering (DLS) experiments confirm the formation of solvent-controlled dendrimer aggregates in the systems. Comparison of the fluorescence and DLS data reveals that the size distribution of the dendrimer aggregates in each solvent system is distinct, which control the intrinsic emission intensity from PAMAM dendrimers. The experimental results suggest that intrinsic emission intensity from PAMAM dendrimers can be regulated by proper selection of solvents at neutral conditions and room temperature

Perceptions of the activity, the social climate, and the self during group exercise classes regulate intrinsic satisfaction.

Science.gov (United States)

Maher, Jaclyn P; Gottschall, Jinger S; Conroy, David E

2015-01-01

Engaging in regular physical activity is a challenging task for many adults. Intrinsic satisfaction with exercise classes is thought to promote adherence to physical activity. This study examined the characteristics of exercise classes that impact within-person changes in intrinsic satisfaction over the course of an extended group exercise program. A 30-week physical activity trial was conducted with assessments at the end of each class. Community-living adults (n = 29) were instructed to complete at least six group exercise classes each week and, following each exercise class, complete a questionnaire asking about the characteristics of the class and the participant's evaluation of the class. Intrinsic satisfaction was high, on average, but varied as much within-person from class-to-class as it did between exercisers. Participants reported the greatest intrinsic satisfaction when classes placed greater emphasis on exercisers' involvement with the group task, feelings of competence, and encouragement from the instructor. For the most part, exercise classes that were more intense than usual were perceived by exercisers as less intrinsically satisfying. Some overall characteristics of the exercise classes were also associated with intrinsic satisfaction. The social and motivational characteristics of group exercise classes contribute to exercisers' intrinsic satisfaction with classes and attention to those dynamics, as well as the intensity of the exercise, may improve adherence for exercise regimens.

Bidirectional Cardio-Respiratory Interactions in Heart Failure.

Science.gov (United States)

Radovanović, Nikola N; Pavlović, Siniša U; Milašinović, Goran; Kirćanski, Bratislav; Platiša, Mirjana M

2018-01-01

We investigated cardio-respiratory coupling in patients with heart failure by quantification of bidirectional interactions between cardiac (RR intervals) and respiratory signals with complementary measures of time series analysis. Heart failure patients were divided into three groups of twenty, age and gender matched, subjects: with sinus rhythm (HF-Sin), with sinus rhythm and ventricular extrasystoles (HF-VES), and with permanent atrial fibrillation (HF-AF). We included patients with indication for implantation of implantable cardioverter defibrillator or cardiac resynchronization therapy device. ECG and respiratory signals were simultaneously acquired during 20 min in supine position at spontaneous breathing frequency in 20 healthy control subjects and in patients before device implantation. We used coherence, Granger causality and cross-sample entropy analysis as complementary measures of bidirectional interactions between RR intervals and respiratory rhythm. In heart failure patients with arrhythmias (HF-VES and HF-AF) there is no coherence between signals ( p respiratory signal in HF-VES. Cross-sample entropy analysis revealed the strongest synchrony between respiratory and RR signal in HF-VES group. Beside respiratory sinus arrhythmia there is another type of cardio-respiratory interaction based on the synchrony between cardiac and respiratory rhythm. Both of them are altered in heart failure patients. Respiratory sinus arrhythmia is reduced in HF-Sin patients and vanished in heart failure patients with arrhythmias. Contrary, in HF-Sin and HF-VES groups, synchrony increased, probably as consequence of some dominant neural compensatory mechanisms. The coupling of cardiac and respiratory rhythm in heart failure patients varies depending on the presence of atrial/ventricular arrhythmias and it could be revealed by complementary methods of time series analysis.

Salience network dynamics underlying successful resistance of temptation

Science.gov (United States)

Nomi, Jason S; Calhoun, Vince D; Stelzel, Christine; Paschke, Lena M; Gaschler, Robert; Goschke, Thomas; Walter, Henrik; Uddin, Lucina Q

2017-01-01

Abstract Self-control and the ability to resist temptation are critical for successful completion of long-term goals. Contemporary models in cognitive neuroscience emphasize the primary role of prefrontal cognitive control networks in aligning behavior with such goals. Here, we use gaze pattern analysis and dynamic functional connectivity fMRI data to explore how individual differences in the ability to resist temptation are related to intrinsic brain dynamics of the cognitive control and salience networks. Behaviorally, individuals exhibit greater gaze distance from target location (e.g. higher distractibility) during presentation of tempting erotic images compared with neutral images. Individuals whose intrinsic dynamic functional connectivity patterns gravitate toward configurations in which salience detection systems are less strongly coupled with visual systems resist tempting distractors more effectively. The ability to resist tempting distractors was not significantly related to intrinsic dynamics of the cognitive control network. These results suggest that susceptibility to temptation is governed in part by individual differences in salience network dynamics and provide novel evidence for involvement of brain systems outside canonical cognitive control networks in contributing to individual differences in self-control. PMID:29048582

Robust stability of bidirectional associative memory neural networks with time delays

Science.gov (United States)

Park, Ju H.

2006-01-01

Based on the Lyapunov Krasovskii functionals combined with linear matrix inequality approach, a novel stability criterion is proposed for asymptotic stability of bidirectional associative memory neural networks with time delays. A novel delay-dependent stability criterion is given in terms of linear matrix inequalities, which can be solved easily by various optimization algorithms.

Robust stability of bidirectional associative memory neural networks with time delays

International Nuclear Information System (INIS)

Park, Ju H.

2006-01-01

Based on the Lyapunov-Krasovskii functionals combined with linear matrix inequality approach, a novel stability criterion is proposed for asymptotic stability of bidirectional associative memory neural networks with time delays. A novel delay-dependent stability criterion is given in terms of linear matrix inequalities, which can be solved easily by various optimization algorithms

Anomalous intrinsic viscosity of octadecylamine-functionalised carbon nanotubes in suspension.

Science.gov (United States)

Donovan, K J; Scott, K

2013-06-28

Single walled carbon nanotubes, SWCNTs, are used as a model cylinder of nanoscopic dimensions for testing rheological theories of how addition of cylindrical particles affects the viscosity of a suspension of such particles. Using the rate of growth of the accompanying induced linear dichroism following application of an applied electric field, the dynamics of carbon nanotube alignment is studied in suspensions of octadecylamine functionalised single walled carbon nanotubes, ODA-SWCNTs, in 1,2 dichloroethane. From such measurements the viscosity of the suspension is measured as the concentration of the suspension is varied. While working within the dilute limit the viscosity is found to increase linearly with concentration and the intrinsic viscosity of the suspension is found to be 8000. This anomalously high intrinsic viscosity is compared with the predictions of various models for a rigid cylinder and found to be incompatible with any of the current models. Some suggestions are made as to the way this ODA-SWCNT result may be eventually accommodated within other models.

Characterization of the Intrinsic Water Wettability of Graphite Using Contact Angle Measurements: Effect of Defects on Static and Dynamic Contact Angles.

Science.gov (United States)

Kozbial, Andrew; Trouba, Charlie; Liu, Haitao; Li, Lei

2017-01-31

Elucidating the intrinsic water wettability of the graphitic surface has increasingly attracted research interests, triggered by the recent finding that the well-established hydrophobicity of graphitic surfaces actually results from airborne hydrocarbon contamination. Currently, static water contact angle (WCA) is often used to characterize the intrinsic water wettability of graphitic surfaces. In the current paper, we show that because of the existence of defects, static WCA does not necessarily characterize the intrinsic water wettability. Freshly exfoliated graphite of varying qualities, characterized using atomic force microscopy and Raman spectroscopy, was studied using static, advancing, and receding WCA measurements. The results showed that graphite of different qualities (i.e., defect density) always has a similar advancing WCA, but it could have very different static and receding WCAs. This finding indicates that defects play an important role in contact angle measurements, and the static contact angle does not always represent the intrinsic water wettability of pristine graphite. On the basis of the experimental results, a qualitative model is proposed to explain the effect of defects on static, advancing, and receding contact angles. The model suggests that the advancing WCA reflects the intrinsic water wettability of pristine (defect-free) graphite. Our results showed that the advancing WCA for pristine graphite is 68.6°, which indicates that graphitic carbon is intrinsically mildly hydrophilic.

Symmetries of collective models in intrinsic frame

International Nuclear Information System (INIS)

Gozdz, A.; Pedrak, A.; Szulerecka, A.; Dobrowolski, A.; Dudek, J.

2013-01-01

In the paper a very general definition of intrinsic frame, by means of group theoretical methods, is introduced. It allows to analyze nuclear properties which are invariant in respect to the group which defines the intrinsic frame. For example, nuclear shape is a well determined feature in the intrinsic frame defined by the Euclidean group. It is shown that using of intrinsic frame gives an opportunity to consider intrinsic nuclear symmetries which are independent of symmetries observed in the laboratory frame. An importance of the notion of partial symmetries is emphasized. (author)

Intrinsic shapes of discy and boxy ellipticals

International Nuclear Information System (INIS)

Fasano, Giovanni

1991-01-01

Statistical tests for intrinsic shapes of elliptical galaxies have given so far inconclusive and sometimes contradictory results. These failures have been often charged to the fact that classical tests consider only the two axisymmetric shapes (oblate versus prolate), while ellipticals are truly triaxial bodies. On the other hand, recent analyses indicate that the class of elliptical galaxies could be a mixture of (at least) two families having different morphology and dynamical behaviour: (i) a family of fast-rotating, disc-like ellipticals (discy); (ii) a family of slow-rotating, box-shaped ellipticals (boxy). In this paper we review the tests for instrinsic shapes of elliptical galaxies using data of better quality (CCD) with respect to previous applications. (author)

Investigations of bi-directional flow behaviour in presence of a large vertical opening in a fire compartment

International Nuclear Information System (INIS)

Sharma, Pavan K.; Gera, B.

2011-01-01

In the complex thermal hydraulics codes developed for fire, reactor and containment safety the junctions in the multi-compartment geometries are often modeled as uni-directional junctions and some construct of flow coefficient. However, certain large size junctions are known to depict bi-directional flow behaviour under specific circumstances. The CFD based computer code FDS was used for an earlier reported study of fire in an enclosure on the bidirectional flow behaviour in present of a wall opening. Numerical simulation is directed to monitor the entrainment of the fresh air from outside to the fire compartment and resulting plume deflection due to presence of a big opening. The paper presents the details of the analysis, the results obtained, and comparison with the reported experimental data in terms of plume deflection, entrainment. Detailed investigations have been carried out to understand the bi-directionality of a junction by analyzing studying the outgoing hot air flow and incoming cold air. (orig.)

Chaos synchronization communication using extremely unsymmetrical bidirectional injections.

Science.gov (United States)

Zhang, Wei Li; Pan, Wei; Luo, Bin; Zou, Xi Hua; Wang, Meng Yao; Zhou, Zhi

2008-02-01

Chaos synchronization and message transmission between two semiconductor lasers with extremely unsymmetrical bidirectional injections (EUBIs) are discussed. By using EUBIs, synchronization is realized through injection locking. Numerical results show that if the laser subjected to strong injection serves as the receiver, chaos pass filtering (CPF) of the system is similar to that of unidirectional coupled systems. Moreover, if the other laser serves as the receiver, a stronger CPF can be obtained. Finally, we demonstrate that messages can be extracted successfully from either of the two transmission directions of the system.

Applying deep bidirectional LSTM and mixture density network for basketball trajectory prediction

NARCIS (Netherlands)

Zhao, Yu; Yang, Rennong; Chevalier, Guillaume; Shah, Rajiv C.; Romijnders, Rob

2018-01-01

Data analytics helps basketball teams to create tactics. However, manual data collection and analytics are costly and ineffective. Therefore, we applied a deep bidirectional long short-term memory (BLSTM) and mixture density network (MDN) approach. This model is not only capable of predicting a

Branching in current-voltage characteristics of intrinsic Josephson junctions

International Nuclear Information System (INIS)

Shukrinov, Yu M; Mahfouzi, F

2007-01-01

We study branching in the current-voltage characteristics of the intrinsic Josephson junctions of high-temperature superconductors in the framework of the capacitively coupled Josephson junction model with diffusion current. A system of dynamical equations for the gauge-invariant phase differences between superconducting layers for a stack of ten intrinsic junctions has been numerically solved. We have obtained a total branch structure in the current-voltage characteristics. We demonstrate the existence of a 'breakpoint region' on the current-voltage characteristics and explain it as a result of resonance between Josephson and plasma oscillations. The effect of the boundary conditions is investigated. The existence of two outermost branches and correspondingly two breakpoint regions for the periodic boundary conditions is shown. One branch, which is observed only at periodic boundary conditions, corresponds to the propagating of the plasma mode. The second one corresponds to the situation when the charge oscillations on the superconducting layers are absent, excluding the breakpoint. A time dependence of the charge oscillations at breakpoints is presented

Brain intrinsic network connectivity in individuals with frequent tanning behavior.

Science.gov (United States)

Ketcherside, Ariel; Filbey, Francesca M; Aubert, Pamela M; Seibyl, John P; Price, Julianne L; Adinoff, Bryon

2018-05-01

Emergent studies suggest a bidirectional relationship between brain functioning and the skin. This neurocutaneous connection may be responsible for the reward response to tanning and, thus, may contribute to excessive tanning behavior. To date, however, this association has not yet been examined. To explore whether intrinsic brain functional connectivity within the default mode network (DMN) is related to indoor tanning behavior. Resting state functional connectivity (rsFC) was obtained in twenty adults (16 females) with a history of indoor tanning. Using a seed-based [(posterior cingulate cortex (PCC)] approach, the relationship between tanning severity and FC strength was assessed. Tanning severity was measured with symptom count from the Structured Clinical Interview for Tanning Abuse and Dependence (SITAD) and tanning intensity (lifetime indoor tanning episodes/years tanning). rsFC strength between the PCC and other DMN regions (left globus pallidus, left medial frontal gyrus, left superior frontal gyrus) is positively correlated with tanning symptom count. rsFC strength between the PCC and salience network regions (right anterior cingulate cortex, left inferior parietal lobe, left inferior temporal gyrus) is correlated with tanning intensity. Greater connectivity between tanning severity and DMN and salience network connectivity suggests that heightened self-awareness of salient stimuli may be a mechanism that underlies frequent tanning behavior. These findings add to the growing evidence of brain-skin connection and reflect dysregulation in the reward processing networks in those with frequent tanning.

Observations of a bi-directional lightning leader producing an M-component

Science.gov (United States)

Kotovsky, D. A.; Uman, M. A.; Wilkes, R.; Carvalho, F. L.; Jordan, D. M.

2017-12-01

Lightning discharges to ground often exhibit millisecond-scale surges in the continuing currents following return strokes, called M-components. Relatively little is known regarding the source of M-component charge and the mechanisms by which that charge is transferred to ground. In this work, we seek to directly address these questions by presenting correlated high-speed video and Lightning Mapping Array (LMA) observations of a bi-directional leader that resulted in an M-component occurring in a rocket-and-wire triggered lightning flash. The observed leader initiated in the decayed remnants of a positive leader channel that had traversed virgin air approximately 90 msec prior. Three-dimensional locations and speeds of the photographed bi-directional leader and M-component processes are calculated by mapping video images to the observed LMA channel geometry. Both ends of the bi-directional leader exhibited speeds on the order of 2 x106 m sec-1 over 570 meters of the visible channel. Propagation of the luminosity wave from the in-cloud leader to ground ( 8.8 km channel length) exhibited appreciable dispersion, with rise-times (10-90%) increasing from 330 to 410 μsec and pulse-widths (half-maximum) increasing from 380 to 810 μsec - the M-component current pulse measured at ground-level exhibited a rise-time of 290 μsec and a pulse-width of 770 μsec. Group velocities of the luminosity wave have been calculated as a function of frequency, increasing from 2 x107 to 6 x107 m sec-1 over the dominant signal bandwidth (DC to 2 kHz). Additionally, multiple waves of luminosity are observed within the in-cloud channel, indicating nuanced wave phenomena possibly associated with reflection from the end of the leader channel and attachment with the main lightning channel carrying continuing current to ground.

Automatic Detection of Respiratory Events During Sleep Using Bidirectional LSTM Networks

DEFF Research Database (Denmark)

Jacobsen, K. P.; Olesen, Alexander Neergaard; Trap, L.

2018-01-01

seconds overlap. Two models were developed based on bidirectional long short-term memory (bLSTM) neural networks: 1)a two-class model for classification of windows as “normal” or “event”, and 2)a four-class model for classification as “normal”, “obstructive”, “central”, or “mixed”. 1882 subjects were used...

Developmental trajectories of irritability and bidirectional associations with maternal depression.

Science.gov (United States)

Wiggins, Jillian Lee; Mitchell, Colter; Stringaris, Argyris; Leibenluft, Ellen

2014-11-01

Irritability is a dimensional trait in typical development and a common presenting symptom in many psychiatric disorders, including depression. However, little is known about the developmental trajectory of irritability or how child irritability interacts with maternal depression. The present study identifies classes of irritability trajectories from toddlerhood to middle childhood; characterizes maternal depression and other family, social environment, and child variables within each irritability trajectory class; and, as a more exploratory analysis, examines bidirectional associations between maternal depression and child irritability. A total of 4,898 families from the Fragile Families and Child Wellbeing Study reported on irritability symptoms at ages 3, 5, and 9 years, assessed with items from the Child Behavior Checklist. Parental major depressive episode was assessed using the Composite International Diagnostic Interview-Short Form at child ages 1, 3, 5, and 9 years. A latent class growth analysis identified 5 irritability classes: low decreasing; moderate decreasing; high steady; initially very high, then decreasing; and high increasing. Children with more severe irritability trajectories are more likely to have mothers with recurrent depression, and, with the exception of the most severe (high increasing irritability) class, were more likely to have mothers who were exposed to violence. Moreover, paternal depression and alcohol abuse, as well as maternal drug and alcohol abuse, were also risk factors for membership in the more severe irritability classes. A latent auto-regressive cross-lag model showed that child irritability at ages 3 and 5 years is associated with increased mother depression at ages 5 and 9, respectively. Conversely, mother depression at child ages 1 and 3 years is associated with increased child irritability at 3 and 5. Irritability development across toddlerhood and middle childhood has 5 main trajectory types, which differ on maternal

Intraparticulate Metal Speciation Analysis of Soft Complexing Nanoparticles. The Intrinsic Chemical Heterogeneity of Metal-Humic Acid Complexes

DEFF Research Database (Denmark)

Town, R. M.; van Leeuwen, Herman P.

2016-01-01

ion condensation potential for higher valency counterions within the intraparticulate double layer zone of the soft NP. The approach offers new insights into the intrinsic heterogeneity of the HA. complexes, as revealed by the intraparticulate speciation as a function of the true degree of inner......-sphere complexation, theta(M). The ensuing intrinsic heterogeneity parameters, Gamma, for CdHA and CuHA complexes are in very good agreement with those obtained from dynamic electrochemical stripping chronopotentiometric measurements. The overall intraparticulate metal ion speciation is found to depend on theta...

A global first integral for certain dynamical systems and related remarks

International Nuclear Information System (INIS)

Gonzalez-Gascon, F.

1977-01-01

A global first integral for certain dynamical systems and the related remarks are presented. In particular, it is shown that for these dynamical systems by introducing the (intrinsic) definition of the divergence of a vector field defined on an orientable differentiable manifold, the first integral, i.e. the (intrinsic) divergence of a vector field is now, automatically, a global first integral. (author)

Bi-directional triplexer with butterfly MMI coupler using SU-8 polymer waveguides

Science.gov (United States)

Mareš, David; Jeřábek, Vítězslav; Prajzler, Václav

2015-01-01

We report about a design of a bi-directional planar optical multiplex/demultiplex filter (triplexer) for the optical part of planar hybrid WDM bi-directional transceiver in fiber-to-the-home (FTTH) PON applications. The triplex lightwave circuit is based on the Epoxy Novolak Resin SU-8 waveguides on the silica-on-silicon substrate with Polymethylmethacrylate cladding layer. The triplexer is comprised of a linear butterfly concept of multimode interference (MMI) coupler separating downstream optical signals of 1490 nm and 1550 nm. For the upstream channel of 1310 nm, an additional directional coupler (DC) is used to add optical signal of 1310 nm propagating in opposite direction. The optical triplexer was designed and optimized using beam propagation method. The insertion losses, crosstalk attenuation, and extinction ratio for all three inputs/outputs were investigated. The intended triplexer was designed using the parameters of the separated DC and MMI filter to approximate the idealized direct connection of both devices.

Cost-effective bidirectional digitized radio-over-fiber systems employing sigma delta modulation

Science.gov (United States)

Lee, Kyung Woon; Jung, HyunDo; Park, Jung Ho

2016-11-01

We propose a cost effective digitized radio-over-fiber (D-RoF) system employing a sigma delta modulation (SDM) and a bidirectional transmission technique using phase modulated downlink and intensity modulated uplink. SDM is transparent to different radio access technologies and modulation formats, and more suitable for a downlink of wireless system because a digital to analog converter (DAC) can be avoided at the base station (BS). Also, Central station and BS share the same light source by using a phase modulation for the downlink and an intensity modulation for the uplink transmission. Avoiding DACs and light sources have advantages in terms of cost reduction, power consumption, and compatibility with conventional wireless network structure. We have designed a cost effective bidirectional D-RoF system using a low pass SDM and measured the downlink and uplink transmission performance in terms of error vector magnitude, signal spectra, and constellations, which are based on the 10MHz LTE 64-QAM standard.

Stochastic synchronization of neuronal populations with intrinsic and extrinsic noise.

KAUST Repository

Bressloff, Paul C

2011-05-03

We extend the theory of noise-induced phase synchronization to the case of a neural master equation describing the stochastic dynamics of an ensemble of uncoupled neuronal population oscillators with intrinsic and extrinsic noise. The master equation formulation of stochastic neurodynamics represents the state of each population by the number of currently active neurons, and the state transitions are chosen so that deterministic Wilson-Cowan rate equations are recovered in the mean-field limit. We apply phase reduction and averaging methods to a corresponding Langevin approximation of the master equation in order to determine how intrinsic noise disrupts synchronization of the population oscillators driven by a common extrinsic noise source. We illustrate our analysis by considering one of the simplest networks known to generate limit cycle oscillations at the population level, namely, a pair of mutually coupled excitatory (E) and inhibitory (I) subpopulations. We show how the combination of intrinsic independent noise and extrinsic common noise can lead to clustering of the population oscillators due to the multiplicative nature of both noise sources under the Langevin approximation. Finally, we show how a similar analysis can be carried out for another simple population model that exhibits limit cycle oscillations in the deterministic limit, namely, a recurrent excitatory network with synaptic depression; inclusion of synaptic depression into the neural master equation now generates a stochastic hybrid system.

The Role of PTSD in Bi-directional Intimate Partner Violence in Military and Veteran Populations: A Research Review

Directory of Open Access Journals (Sweden)

Gabriela Misca

2017-08-01

Full Text Available Evidence supporting the higher prevalence of PTSD linked to combat-related trauma in military personnel and veteran populations is well-established. Consequently, much research has explored the effects that combat related trauma and the subsequent PTSD may have on different aspects of relationship functioning and adjustment. In particular, PTSD in military and veterans has been linked with perpetrating intimate partner violence (IPV. New research and theoretical perspectives suggest that in order to respond effectively to IPV, a more accurate understanding of the direction of the violence experienced within each relationship is critical. In both civilian and military populations, research that has examined the direction of IPV's, bi-directional violence have been found to be highly prevalent. Evidence is also emerging as to how these bi-directional violence differ in relation to severity, motivation, physical and psychological consequences and risk factors. Of particular importance within military IPV research is the need to deepen understanding about the role of PTSD in bi-directional IPV not only as a risk factor for perpetration but also as a vulnerability risk factor for victimization, as findings from recent research suggest. This paper provides a timely, critical review of emergent literature to disentangle what is known about bi-directional IPV patterns in military and veteran populations and the roles that military or veterans' PTSD may play within these patterns. Although, this review aimed to identify global research on the topic, the majority of research meeting the inclusion criteria was from US, with only one study identified from outside, from Canada. Strengths and limitations in the extant research are identified. Directions for future research are proposed with a particular focus on the kinds of instruments and designs needed to better capture the complex interplay of PTSD and bi-directional IPV in military populations and

Assessment of a Bidirectional Reflectance Distribution Correction of Above-Water and Satellite Water-Leaving Radiance in Coastal Waters

Science.gov (United States)

Hlaing, Soe; Gilerson, Alexander; Harmal, Tristan; Tonizzo, Alberto; Weidemann, Alan; Arnone, Robert; Ahmed, Samir

2012-01-01

Water-leaving radiances, retrieved from in situ or satellite measurements, need to be corrected for the bidirectional properties of the measured light in order to standardize the data and make them comparable with each other. The current operational algorithm for the correction of bidirectional effects from the satellite ocean color data is optimized for typical oceanic waters. However, versions of bidirectional reflectance correction algorithms specifically tuned for typical coastal waters and other case 2 conditions are particularly needed to improve the overall quality of those data. In order to analyze the bidirectional reflectance distribution function (BRDF) of case 2 waters, a dataset of typical remote sensing reflectances was generated through radiative transfer simulations for a large range of viewing and illumination geometries. Based on this simulated dataset, a case 2 water focused remote sensing reflectance model is proposed to correct above-water and satellite water-leaving radiance data for bidirectional effects. The proposed model is first validated with a one year time series of in situ above-water measurements acquired by collocated multispectral and hyperspectral radiometers, which have different viewing geometries installed at the Long Island Sound Coastal Observatory (LISCO). Match-ups and intercomparisons performed on these concurrent measurements show that the proposed algorithm outperforms the algorithm currently in use at all wavelengths, with average improvement of 2.4% over the spectral range. LISCO's time series data have also been used to evaluate improvements in match-up comparisons of Moderate Resolution Imaging Spectroradiometer satellite data when the proposed BRDF correction is used in lieu of the current algorithm. It is shown that the discrepancies between coincident in-situ sea-based and satellite data decreased by 3.15% with the use of the proposed algorithm.

Evolutionary Pseudo-Relaxation Learning Algorithm for Bidirectional Associative Memory

Institute of Scientific and Technical Information of China (English)

Sheng-Zhi Du; Zeng-Qiang Chen; Zhu-Zhi Yuan

2005-01-01

This paper analyzes the sensitivity to noise in BAM (Bidirectional Associative Memory), and then proves the noise immunity of BAM relates not only to the minimum absolute value of net inputs (MAV) but also to the variance of weights associated with synapse connections. In fact, it is a positive monotonically increasing function of the quotient of MAV divided by the variance of weights. Besides, the performance of pseudo-relaxation method depends on learning parameters (λ and ζ), but the relation of them is not linear. So it is hard to find a best combination of λ and ζ which leads to the best BAM performance. And it is obvious that pseudo-relaxation is a kind of local optimization method, so it cannot guarantee to get the global optimal solution. In this paper, a novel learning algorithm EPRBAM (evolutionary psendo-relaxation learning algorithm for bidirectional association memory) employing genetic algorithm and pseudo-relaxation method is proposed to get feasible solution of BAM weight matrix. This algorithm uses the quotient as the fitness of each individual and employs pseudo-relaxation method to adjust individual solution when it does not satisfy constraining condition any more after genetic operation. Experimental results show this algorithm improves noise immunity of BAM greatly. At the same time, EPRBAM does not depend on learning parameters and can get global optimal solution.

The Bidirectional Relationship between Sleep and Immunity against Infections

Directory of Open Access Journals (Sweden)

Elizabeth G. Ibarra-Coronado

2015-01-01

Full Text Available Sleep is considered an important modulator of the immune response. Thus, a lack of sleep can weaken immunity, increasing organism susceptibility to infection. For instance, shorter sleep durations are associated with a rise in suffering from the common cold. The function of sleep in altering immune responses must be determined to understand how sleep deprivation increases the susceptibility to viral, bacterial, and parasitic infections. There are several explanations for greater susceptibility to infections after reduced sleep, such as impaired mitogenic proliferation of lymphocytes, decreased HLA-DR expression, the upregulation of CD14+, and variations in CD4+ and CD8+ T lymphocytes, which have been observed during partial sleep deprivation. Also, steroid hormones, in addition to regulating sexual behavior, influence sleep. Thus, we hypothesize that sleep and the immune-endocrine system have a bidirectional relationship in governing various physiological processes, including immunity to infections. This review discusses the evidence on the bidirectional effects of the immune response against viral, bacterial, and parasitic infections on sleep patterns and how the lack of sleep affects the immune response against such agents. Because sleep is essential in the maintenance of homeostasis, these situations must be adapted to elicit changes in sleep patterns and other physiological parameters during the immune response to infections to which the organism is continuously exposed.

Determination of Intrinsic Magnetic Response from Local Measurements of Fringing Fields

OpenAIRE

Wen, Bo; Millis, Andrew J.; Pardo, Enric; Subedi, Pradeep; Kent, Andrew D.; Yeshurun, Yosi; Sarachik, Myriam P.

2014-01-01

Micron-sized Hall bars and micro-SQUIDs are now used routinely to measure the local static and dynamic magnetic response with micron-scale spatial resolution. While this provides a powerful new tool, determining the intrinsic magnetization presents new challenges, as it requires correcting for demagnetization fields that vary widely with position on a sample. In this paper we develop a method to correct for the demagnetization effect at local points of a rectangular prism shaped sample using ...

Intrinsic Time Quantum Geometrodynamics

OpenAIRE

Ita III, Eyo Eyo; Soo, Chopin; Yu, Hoi-Lai

2015-01-01

Quantum Geometrodynamics with intrinsic time development and momentric variables is presented. An underlying SU(3) group structure at each spatial point regulates the theory. The intrinsic time behavior of the theory is analyzed, together with its ground state and primordial quantum fluctuations. Cotton-York potential dominates at early times when the universe was small; the ground state naturally resolves Penrose's Weyl Curvature Hypothesis, and thermodynamic and gravitational `arrows of tim...

A Markovian Approach Applied to Reliability Modeling of Bidirectional DC-DC Converters Used in PHEVs and Smart Grids

Directory of Open Access Journals (Sweden)

M. Khalilzadeh

2016-12-01

Full Text Available In this paper, a stochastic approach is proposed for reliability assessment of bidirectional DC-DC converters, including the fault-tolerant ones. This type of converters can be used in a smart DC grid, feeding DC loads such as home appliances and plug-in hybrid electric vehicles (PHEVs. The reliability of bidirectional DC-DC converters is of such an importance, due to the key role of the expected increasingly utilization of DC grids in modern Smart Grid. Markov processes are suggested for reliability modeling and consequently calculating the expected effective lifetime of bidirectional converters. A three-leg bidirectional interleaved converter using data of Toyota Prius 2012 hybrid electric vehicle is used as a case study. Besides, the influence of environment and ambient temperature on converter lifetime is studied. The impact of modeling the reliability of the converter and adding reliability constraints on the technical design procedure of the converter is also investigated. In order to investigate the effect of leg increase on the lifetime of the converter, single leg to five-leg interleave DC-DC converters are studied considering economical aspect and the results are extrapolated for six and seven-leg converters. The proposed method could be generalized so that the number of legs and input and output capacitors could be an arbitrary number.

Automatic Detection of Cortical Arousals in Sleep using Bi-direction LSTM Networks

DEFF Research Database (Denmark)

Brink-Kjaer, A.; Olesen, Alexander Neergaard; Jespersen, C. A.

2018-01-01

) and chin electromyography (EMG) to compute a probability of arousals through a bi-directional long short-term memory neural network. The study used a dataset of 233 nocturnal PSGs of population-based samples from Wisconsin Sleep Cohort (WSC) and 30 nocturnal PSGs of clinical samples from the Stanford Sleep...

Bidirectional Associations Between Psychosocial Well-being and Body Mass Index in European Children

DEFF Research Database (Denmark)

Hunsberger, Monica; Lehtinen-Jacks, Susanna; Mehlig, Kirsten

2016-01-01

Background: The negative impact of childhood overweight on psychosocial well-being has been demonstrated in a number of studies. There is also evidence that psychosocial well-being may influence future overweight. We examined the bidirectional association between childhood overweight and psychoso...

Periodontal disease and non-communicable diseases. Strength of bidirectional associations

OpenAIRE

Kassier, SM

2016-01-01

Periodontal disease (PD), along with cardiovascular and circulatory disease, diabetes mellitus, chronic respiratory disease and obesity, are globally regarded as some of the major non-communicable diseases (NCDs). The association between PD and these systemic illnesses is described as bidirectional. Gaining an understanding of the strength of the proposed associations between these diseases is important, as it will enable health professionals to identify common risk factors that will allow fo...

Bidirectional cross metathesis and ring-closing metathesis/ring opening of a C2-symmetric building block: a strategy for the synthesis of decanolide natural products

Directory of Open Access Journals (Sweden)

Bernd Schmidt

2013-11-01

Full Text Available Starting from the conveniently available ex-chiral pool building block (R,R-hexa-1,5-diene-3,4-diol, the ten-membered ring lactones stagonolide E and curvulide A were synthesized using a bidirectional olefin-metathesis functionalization of the terminal double bonds. Key steps are (i a site-selective cross metathesis, (ii a highly diastereoselective extended tethered RCM to furnish a (Z,E-configured dienyl carboxylic acid and (iii a Ru–lipase-catalyzed dynamic kinetic resolution to establish the desired configuration at C9. Ring closure was accomplished by macrolactonization. Curvulide A was synthesized from stagonolide E through Sharpless epoxidation.

Bidirectional cross metathesis and ring-closing metathesis/ring opening of a C 2-symmetric building block: a strategy for the synthesis of decanolide natural products.

Science.gov (United States)

Schmidt, Bernd; Kunz, Oliver

2013-01-01

Starting from the conveniently available ex-chiral pool building block (R,R)-hexa-1,5-diene-3,4-diol, the ten-membered ring lactones stagonolide E and curvulide A were synthesized using a bidirectional olefin-metathesis functionalization of the terminal double bonds. Key steps are (i) a site-selective cross metathesis, (ii) a highly diastereoselective extended tethered RCM to furnish a (Z,E)-configured dienyl carboxylic acid and (iii) a Ru-lipase-catalyzed dynamic kinetic resolution to establish the desired configuration at C9. Ring closure was accomplished by macrolactonization. Curvulide A was synthesized from stagonolide E through Sharpless epoxidation.

Bidirectional Cardio-Respiratory Interactions in Heart Failure

Directory of Open Access Journals (Sweden)

Nikola N. Radovanović

2018-03-01

Full Text Available We investigated cardio-respiratory coupling in patients with heart failure by quantification of bidirectional interactions between cardiac (RR intervals and respiratory signals with complementary measures of time series analysis. Heart failure patients were divided into three groups of twenty, age and gender matched, subjects: with sinus rhythm (HF-Sin, with sinus rhythm and ventricular extrasystoles (HF-VES, and with permanent atrial fibrillation (HF-AF. We included patients with indication for implantation of implantable cardioverter defibrillator or cardiac resynchronization therapy device. ECG and respiratory signals were simultaneously acquired during 20 min in supine position at spontaneous breathing frequency in 20 healthy control subjects and in patients before device implantation. We used coherence, Granger causality and cross-sample entropy analysis as complementary measures of bidirectional interactions between RR intervals and respiratory rhythm. In heart failure patients with arrhythmias (HF-VES and HF-AF there is no coherence between signals (p < 0.01, while in HF-Sin it is reduced (p < 0.05, compared with control subjects. In all heart failure groups causality between signals is diminished, but with significantly stronger causality of RR signal in respiratory signal in HF-VES. Cross-sample entropy analysis revealed the strongest synchrony between respiratory and RR signal in HF-VES group. Beside respiratory sinus arrhythmia there is another type of cardio-respiratory interaction based on the synchrony between cardiac and respiratory rhythm. Both of them are altered in heart failure patients. Respiratory sinus arrhythmia is reduced in HF-Sin patients and vanished in heart failure patients with arrhythmias. Contrary, in HF-Sin and HF-VES groups, synchrony increased, probably as consequence of some dominant neural compensatory mechanisms. The coupling of cardiac and respiratory rhythm in heart failure patients varies depending on the

BiPOD Arthroscopic Acromioclavicular Repair Restores Bidirectional Stability.

Science.gov (United States)

De Beer, Joe; Schaer, Michael; Latendresse, Kim; Raniga, Sumit; Moor, Beat K; Zumstein, Matthias A

2017-01-01

Stabilizing the acromioclavicular joint in the vertical and horizontal planes is challenging, and most current techniques do not reliably achieve this goal. The BiPOD repair is an arthroscopically assisted procedure performed with image intensifier guidance that reconstructs the coracoclavicular ligaments as well as the acromioclavicular ligaments to achieve bidirectional stability. Repair is achieved with a combination of 2-mm FiberTape (Arthrex, Naples, Florida) and 20-mm Poly-Tape (Neoligaments, Leeds, England) to achieve rigid repair, prevent bone abrasion, and promote tissue ingrowth. This study is a prospective review of the first 6 patients treated for high-grade acute acromioclavicular injury with the BiPOD technique. The study included 6 men who were 21 to 36 years old (mean, 27 years). At 6-month follow-up, complications were recorded and radiographic analysis was used to determine the coracoclavicular distance for vertical reduction and the amount of acromioclavicular translation on the Alexander axillary view was used to determine horizontal reduction. One patient had a superficial infection over the tape knot. The difference in coracoclavicular distance between the operated side and the uninvolved side was 9±2 mm preoperatively and 0.3±2 mm at 6-month follow-up. On Alexander axillary view, all 6 patients showed stable reduction, which is defined as a clavicle that is in line with the acromion. The findings show that BiPOD acromioclavicular reconstruction restores bidirectional stability of the acromioclavicular joint at 6 months. [Orthopedics. 2017; 40(1):e35-e43.]. Copyright 2016, SLACK Incorporated.

SDN-controlled topology-reconfigurable optical mobile fronthaul architecture for bidirectional CoMP and low latency inter-cell D2D in the 5G mobile era.

Science.gov (United States)

Cvijetic, Neda; Tanaka, Akihiro; Kanonakis, Konstantinos; Wang, Ting

2014-08-25

We demonstrate the first SDN-controlled optical topology-reconfigurable mobile fronthaul (MFH) architecture for bidirectional coordinated multipoint (CoMP) and low latency inter-cell device-to-device (D2D) connectivity in the 5G mobile networking era. SDN-based OpenFlow control is used to dynamically instantiate the CoMP and inter-cell D2D features as match/action combinations in control plane flow tables of software-defined optical and electrical switching elements. Dynamic re-configurability is thereby introduced into the optical MFH topology, while maintaining back-compatibility with legacy fiber deployments. 10 Gb/s peak rates with <7 μs back-to-back transmission latency and 29.6 dB total power budget are experimentally demonstrated, confirming the attractiveness of the new approach for optical MFH of future 5G mobile systems.

An Analysis of Intrinsic and Extrinsic Hand Muscle EMG for Improved Pattern Recognition Control.

Science.gov (United States)

Adewuyi, Adenike A; Hargrove, Levi J; Kuiken, Todd A

2016-04-01

Pattern recognition control combined with surface electromyography (EMG) from the extrinsic hand muscles has shown great promise for control of multiple prosthetic functions for transradial amputees. There is, however, a need to adapt this control method when implemented for partial-hand amputees, who possess both a functional wrist and information-rich residual intrinsic hand muscles. We demonstrate that combining EMG data from both intrinsic and extrinsic hand muscles to classify hand grasps and finger motions allows up to 19 classes of hand grasps and individual finger motions to be decoded, with an accuracy of 96% for non-amputees and 85% for partial-hand amputees. We evaluated real-time pattern recognition control of three hand motions in seven different wrist positions. We found that a system trained with both intrinsic and extrinsic muscle EMG data, collected while statically and dynamically varying wrist position increased completion rates from 73% to 96% for partial-hand amputees and from 88% to 100% for non-amputees when compared to a system trained with only extrinsic muscle EMG data collected in a neutral wrist position. Our study shows that incorporating intrinsic muscle EMG data and wrist motion can significantly improve the robustness of pattern recognition control for application to partial-hand prosthetic control.

Temporal dynamics of sand dune bidirectional reflectance characteristics for absolute radiometric calibration of optical remote sensing data

Science.gov (United States)

Coburn, Craig A.; Logie, Gordon S. J.

2018-01-01

Attempts to use pseudoinvariant calibration sites (PICS) for establishing absolute radiometric calibration of Earth observation (EO) satellites requires high-quality information about the nature of the bidirectional reflectance distribution function (BRDF) of the surfaces used for these calibrations. Past studies have shown that the PICS method is useful for evaluating the trend of sensors over time or for the intercalibration of sensors. The PICS method was not considered until recently for deriving absolute radiometric calibration. This paper presents BRDF data collected by a high-performance portable goniometer system to develop a temporal BRDF model for the Algodones Dunes in California. By sampling the BRDF of the sand surface at similar solar zenith angles to those normally encountered by EO satellites, additional information on the changing nature of the surface can improve models used to provide absolute radiometric correction. The results demonstrated that the BRDF of a reasonably simple sand surface was complex with changes in anisotropy taking place in response to changing solar zenith angles. For the majority of observation and illumination angles, the spectral reflectance anisotropy observed varied between 1% and 5% in patterns that repeat around solar noon.

Bi-directional charger for swiss2G - Annual report; Bi-directional charger for swiss2G - Jahresbericht

Energy Technology Data Exchange (ETDEWEB)

Schwab, M.; Baumann, P.

2010-11-15

This short annual report for 2010 for the Swiss Federal Office of Energy (SFOE) takes a look at a bi-directional charger that can be used in intelligent 'Smart Grid' applications. The idea is based on being able to use electric vehicles as a source of electricity to help meet peak demand for mains electricity. The swiss2G project aims to produce an electric car battery-charger that also functions as an inverter to convert the car's DC battery voltage to mains electricity. The project was started in September 2010. The report describes the aims of the project and reports on initial work done in the areas of safety, switching electronics and AC/DC conversion. National and international co-operation is noted and prospects for further work are discussed.

Intrinsic nonlinearity and method of disturbed observations in inverse problems of celestial mechanics

Science.gov (United States)

Avdyushev, Victor A.

2017-12-01

Orbit determination from a small sample of observations over a very short observed orbital arc is a strongly nonlinear inverse problem. In such problems an evaluation of orbital uncertainty due to random observation errors is greatly complicated, since linear estimations conventionally used are no longer acceptable for describing the uncertainty even as a rough approximation. Nevertheless, if an inverse problem is weakly intrinsically nonlinear, then one can resort to the so-called method of disturbed observations (aka observational Monte Carlo). Previously, we showed that the weaker the intrinsic nonlinearity, the more efficient the method, i.e. the more accurate it enables one to simulate stochastically the orbital uncertainty, while it is strictly exact only when the problem is intrinsically linear. However, as we ascertained experimentally, its efficiency was found to be higher than that of other stochastic methods widely applied in practice. In the present paper we investigate the intrinsic nonlinearity in complicated inverse problems of Celestial Mechanics when orbits are determined from little informative samples of observations, which typically occurs for recently discovered asteroids. To inquire into the question, we introduce an index of intrinsic nonlinearity. In asteroid problems it evinces that the intrinsic nonlinearity can be strong enough to affect appreciably probabilistic estimates, especially at the very short observed orbital arcs that the asteroids travel on for about a hundredth of their orbital periods and less. As it is known from regression analysis, the source of intrinsic nonlinearity is the nonflatness of the estimation subspace specified by a dynamical model in the observation space. Our numerical results indicate that when determining asteroid orbits it is actually very slight. However, in the parametric space the effect of intrinsic nonlinearity is exaggerated mainly by the ill-conditioning of the inverse problem. Even so, as for the

Bi-Directional DC-DC Converter for PHEV Applications

Energy Technology Data Exchange (ETDEWEB)

Abas Goodarzi

2011-01-31

Plug-In Hybrid Electric Vehicles (PHEV) require high power density energy storage system (ESS) for hybrid operation and high energy density ESS for Electric Vehicle (EV) mode range. However, ESS technologies to maximize power density and energy density simultaneously are not commercially feasible. The use of bi-directional DC-DC converter allows use of multiple energy storage, and the flexible DC-link voltages can enhance the system efficiency and reduce component sizing. This will improve fuel consumption, increase the EV mode range, reduce the total weight, reduce battery initial and life cycle cost, and provide flexibility in system design.

The intrinsic resistome of bacterial pathogens.

Science.gov (United States)

Olivares, Jorge; Bernardini, Alejandra; Garcia-Leon, Guillermo; Corona, Fernando; B Sanchez, Maria; Martinez, Jose L

2013-01-01

Intrinsically resistant bacteria have emerged as a relevant health problem in the last years. Those bacterial species, several of them with an environmental origin, present naturally low-level susceptibility to several drugs. It has been proposed that intrinsic resistance is mainly the consequence of the impermeability of cellular envelopes, the activity of multidrug efflux pumps or the lack of appropriate targets for a given family of drugs. However, recently published articles indicate that the characteristic phenotype of susceptibility to antibiotics of a given bacterial species depends on the concerted activity of several elements, what has been named as intrinsic resistome. These determinants comprise not just classical resistance genes. Other elements, several of them involved in basic bacterial metabolic processes, are of relevance for the intrinsic resistance of bacterial pathogens. In the present review we analyze recent publications on the intrinsic resistomes of Escherichia coli and Pseudomonas aeruginosa. We present as well information on the role that global regulators of bacterial metabolism, as Crc from P. aeruginosa, may have on modulating bacterial susceptibility to antibiotics. Finally, we discuss the possibility of searching inhibitors of the intrinsic resistome in the aim of improving the activity of drugs currently in use for clinical practice.

The intrinsic resistome of bacterial pathogens

Directory of Open Access Journals (Sweden)

Jorge Andrés Olivares Pacheco

2013-04-01

Full Text Available Intrinsically resistant bacteria have emerged as a relevant health problem in the last years. Those bacterial species, several of them with an environmental origin, present naturally a low-level susceptibility to several drugs. It has been proposed that intrinsic resistance is mainly the consequence of the impermeability of cellular envelopes, the activity of multidrug efflux pumps or the lack of appropriate targets for a given family of drugs. However, recently published articles indicate that the characteristic phenotype of susceptibility to antibiotics of a given bacterial species depends on the concerted activity of several elements, what has been named as intrinsic resistome. These determinants comprise not just classical resistance genes. Other elements, several of them involved in basic bacterial metabolic processes, are of relevance for the intrinsic resistance of bacterial pathogens. In the present review we analyse recent publications on the intrinsic resistomes of Escherichia coli and Pseudomonas aeruginosa. We present as well information on the role that global regulators of bacterial metabolism, as Crc from P. aeruginosa, may have on modulating bacterial susceptibility to antibiotics. Finally, we discuss the possibility of searching inhibitors of the intrinsic resistome in the aim of improving the activity of drugs currently in use for clinical practice.

Incentives and intrinsic motivation in healthcare.

Science.gov (United States)

Berdud, Mikel; Cabasés, Juan M; Nieto, Jorge

It has been established in the literature that workers within public organisations are intrinsically motivated. This paper is an empirical study of the healthcare sector using methods of qualitative analysis research, which aims to answer the following hypotheses: 1) doctors are intrinsically motivated; 2) economic incentives and control policies may undermine doctors' intrinsic motivation; and 3) well-designed incentives may encourage doctors' intrinsic motivation. We conducted semi-structured interviews à-la-Bewley with 16 doctors from Navarre's Healthcare Service (Servicio Navarro de Salud-Osasunbidea), Spain. The questions were based on current theories of intrinsic motivation and incentives to test the hypotheses. Interviewees were allowed to respond openly without time constraints. Relevant information was selected, quantified and analysed by using the qualitative concepts of saturation and codification. The results seem to confirm the hypotheses. Evidence supporting hypotheses 1 and 2 was gathered from all interviewees, as well as indications of the validity of hypothesis 3 based on interviewees' proposals of incentives. The conclusions could act as a guide to support the optimal design of incentive policies and schemes within health organisations when healthcare professionals are intrinsically motivated. Copyright © 2016 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

Poor School Bonding and Delinquency over Time: Bidirectional Effects and Sex Differences

Science.gov (United States)

Liljeberg, Jenny Freidenfelt; Eklund, Jenny M.; Fritz, Marie Vafors; Klinteberg, Britt af

2011-01-01

The association between poor school bonding and delinquency has only been partly addressed in earlier research. Using a longitudinal design, the objective of our study was to investigate possible bidirectional effects and sex differences between adolescents' experienced school bonding and self-rated delinquency over time. A total of 788…

DEVELOPMENT AND DEMONSTRATION OF A BIDIRECTIONAL ADVECTIVE FLUX METER FOR SEDIMENT-WATER INTERFACE

Science.gov (United States)

A bidirectional advective flux meter for measuring water transport across the sediment-water interface has been successfully developed and field tested. The flow sensor employs a heat-pulse technique combined with a flow collection funnel for the flow measurement. Because the dir...

SiC-based High Efficiency Bidirectional Battery Converter for Smart PV Residential Systems

DEFF Research Database (Denmark)

Pham, Cam; Biris, Valeriu-Ciprian; Teodorescu, Remus

2013-01-01

Smart PV inverters are essential components of future grids. Beside conventional functionalities they can communicate with the grid, supports the grid with reactive power and with active power from internal battery storage. To maximize internal consumption, a high efficiency bidirectional DC-DC c...

Three-port bidirectional converter for electric vehicles : focus on high-frequency coaxial transformer

NARCIS (Netherlands)

Waltrich, G.; Duarte, J.L.; Hendrix, M.A.M.; Paulides, J.J.H.

2010-01-01

A bi-directional multi-port converter can accommodate various energy storages and sources. Therefore, a multiport converter will be a good candidate for application as a future universal converter for (hybrid) electrical vehicles or local distribution systems. The main design challenge of the

Bidirectional Text Messaging to Improve Adherence to Recommended Lipid Testing.

Science.gov (United States)

Baldwin, Laura-Mae; Morrison, Caitlin; Griffin, Jonathan; Anderson, Nick; Edwards, Kelly; Green, Jeff; Waldren, Cleary; Reiter, William

2017-01-01

Synergies between technology and health care in the United States are accelerating, increasing opportunities to leverage these technologies to improve patient care. This study was a collaboration between an academic study team, a rural primary care clinic, and a local nonprofit informatics company developing tools to improve patient care through population management. Our team created a text messaging management tool, then developed methods for and tested the feasibility of bidirectional text messaging to remind eligible patients about the need for lipid testing. We measured patient response to the text messages, then interviewed 8 patients to explore their text messaging experience. Of the 129 patients the clinic was able to contact by phone, 29.4% had no cell phone or text-messaging capabilities. An additional 20% refused to participate. Two thirds of the 28 patients who participated in the text messaging intervention (67.9%) responded to at least 1 of the up to 3 messages. Seven of 8 interviewed patients had a positive text-messaging experience. Bidirectional text messaging is a feasible and largely acceptable form of communication for test reminders that has the potential to reach large numbers of patients in clinical care. © Copyright 2017 by the American Board of Family Medicine.

Bidirectional modulation of goal-directed actions by prefrontal cortical dopamine.

Science.gov (United States)

Hitchcott, Paul K; Quinn, Jennifer J; Taylor, Jane R

2007-12-01

Instrumental actions are a vital cognitive asset that endows an organism with sensitivity to the consequences of its behavior. Response-outcome feedback allows responding to be shaped in order to maximize beneficial, and minimize detrimental, outcomes. Lesions of the medial prefrontal cortex (mPFC) result in behavior that is insensitive to changes in outcome value in animals and compulsive behavior in several human psychopathologies. Such insensitivity to changes in outcome value is a defining characteristic of instrumental habits: responses that are controlled by antecedent stimuli rather than goal expectancy. Little is known regarding the neurochemical substrates mediating this sensitivity. The present experiments used sensitivity to posttraining outcome devaluation to index the action-habit status of instrumental responding. Infusions of dopamine into the ventral mPFC (vmPFC), but not dorsal mPFC, restored outcome sensitivity bidirectionally-decreasing responding following outcome devaluation and increasing responding when the outcome was not devalued. This bidirectionality makes the possibility that these infusions nonspecifically dysregulated vmPFC dopamine transmission unlikely. VmPFC dopamine promoted instrumental responding appropriate to outcome value. Reinforcer consumption data indicated that this was not a consequence of altered sensitivity to the reinforcer itself. We suggest that vmPFC dopamine reengages attentional processes underlying goal-directed behavior.

Determinant and impacts of dynamic inflation in Ethiopia

OpenAIRE

Biresaw, Temesgen Tezera

2014-01-01

This thesis uses quarterly data for the period 1998-2010 to investigate the determinant and impacts of dynamic inflation in Ethiopia. By using Granger causality model approach four testable hypotheses are investigated: (1) does the money supply growth Granger-cause inflation? (2) Does currency devaluation Granger cause inflation? (3) Does inflation affect economic growth? And (4) Does oil price Granger cause of inflation? The empirical results suggest that there existed a bi-directional ...

The signaling role for chloride in the bidirectional communication between neurons and astrocytes.

Science.gov (United States)

Wilson, Corinne S; Mongin, Alexander A

2018-01-09

It is well known that the electrical signaling in neuronal networks is modulated by chloride (Cl - ) fluxes via the inhibitory GABA A and glycine receptors. Here, we discuss the putative contribution of Cl - fluxes and intracellular Cl - to other forms of information transfer in the CNS, namely the bidirectional communication between neurons and astrocytes. The manuscript (i) summarizes the generic functions of Cl - in cellular physiology, (ii) recaps molecular identities and properties of Cl - transporters and channels in neurons and astrocytes, and (iii) analyzes emerging studies implicating Cl - in the modulation of neuroglial communication. The existing literature suggests that neurons can alter astrocytic Cl - levels in a number of ways; via (a) the release of neurotransmitters and activation of glial transporters that have intrinsic Cl - conductance, (b) the metabotropic receptor-driven changes in activity of the electroneutral cation-Cl - cotransporter NKCC1, and (c) the transient, activity-dependent changes in glial cell volume which open the volume-regulated Cl - /anion channel VRAC. Reciprocally, astrocytes are thought to alter neuronal [Cl - ] i through either (a) VRAC-mediated release of the inhibitory gliotransmitters, GABA and taurine, which open neuronal GABA A and glycine receptor/Cl - channels, or (b) the gliotransmitter-driven stimulation of NKCC1. The most important recent developments in this area are the identification of the molecular composition and functional heterogeneity of brain VRAC channels, and the discovery of a new cytosolic [Cl - ] sensor - the Wnk family protein kinases. With new work in the field, our understanding of the role of Cl - in information processing within the CNS is expected to be significantly updated. Copyright © 2018 Elsevier B.V. All rights reserved.

Periodic bidirectional associative memory neural networks with distributed delays

Science.gov (United States)

Chen, Anping; Huang, Lihong; Liu, Zhigang; Cao, Jinde

2006-05-01

Some sufficient conditions are obtained for the existence and global exponential stability of a periodic solution to the general bidirectional associative memory (BAM) neural networks with distributed delays by using the continuation theorem of Mawhin's coincidence degree theory and the Lyapunov functional method and the Young's inequality technique. These results are helpful for designing a globally exponentially stable and periodic oscillatory BAM neural network, and the conditions can be easily verified and be applied in practice. An example is also given to illustrate our results.

The Neuroscience of Growth Mindset and Intrinsic Motivation.

Science.gov (United States)

Ng, Betsy

2018-01-26

Our actions can be triggered by intentions, incentives or intrinsic values. Recent neuroscientific research has yielded some results about the growth mindset and intrinsic motivation. With the advances in neuroscience and motivational studies, there is a global need to utilize this information to inform educational practice and research. Yet, little is known about the neuroscientific interplay between growth mindset and intrinsic motivation. This paper attempts to draw on the theories of growth mindset and intrinsic motivation, together with contemporary ideas in neuroscience, outline the potential for neuroscientific research in education. It aims to shed light on the relationship between growth mindset and intrinsic motivation in terms of supporting a growth mindset to facilitate intrinsic motivation through neural responses. Recent empirical research from the educational neuroscience perspective that provides insights into the interplay between growth mindset and intrinsic motivation will also be discussed.

Bidirectional Texture Function Compression Based on Multi-Level Vector Quantization

Czech Academy of Sciences Publication Activity Database

Havran, V.; Filip, Jiří; Myszkowski, K.

2010-01-01

Roč. 29, č. 1 (2010), s. 175-190 ISSN 0167-7055 R&D Projects: GA MŠk 1M0572; GA ČR GA102/08/0593 Grant - others:EC Marie Curie ERG(CZ) 239294 Institutional research plan: CEZ:AV0Z10750506 Keywords : bidirectional texture function * BRDF * compression * SSIM Subject RIV: BD - Theory of Information Impact factor: 1.455, year: 2010 http://library.utia.cas.cz/separaty/2010/RO/filip-0338804.pdf

Intrinsic line shape of electromagnetic radiation from a stack of intrinsic Josephson junctions synchronized by an internal cavity resonance

Science.gov (United States)

Koshelev, Alexei

2013-03-01

Stacks of intrinsic Josephson-junctions are realized in mesas fabricated out of layered superconducting single crystals, such as Bi2Sr2CaCu2O8 (BSCCO). Synchronization of phase oscillations in different junctions can be facilitated by the coupling to the internal cavity mode leading to powerful and coherent electromagnetic radiation in the terahertz frequency range. An important characteristic of this radiation is the shape of the emission line. A finite line width appears due to different noise sources leading to phase diffusion. We investigated the intrinsic line shape caused by the thermal noise for a mesa fabricated on the top of a BSCCO single crystal. In the ideal case of fully synchronized stack the finite line width is coming from two main contributions, the quasiparticle-current noise inside the mesa and the fluctuating radiation in the base crystal. We compute both contributions and conclude that for realistic mesa's parameters the second mechanism typically dominates. The role of the cavity quality factor in the emission line spectrum is clarified. Analytical results were verified by numerical simulations. In real mesa structures part of the stack may not be synchronized and chaotic dynamics of unsynchronized junctions may determine the real line width. Work supported by UChicago Argonne, LLC, under contract No. DE-AC02-06CH11357.

Extrinsic and Intrinsic Responses to Environmental Change: Insights from Terrestrial Paleoecological Archives

Science.gov (United States)

Seddon, A. W. R.; Mackay, A. W.

2015-12-01

Current understanding of ecological behaviour indicates that systems can experience sudden and abrupt changes in state, driven either by a large external change in environmental conditions (extrinsically forced), or the result of a set local feedbacks and site-specific interactions (intrinsically mediated responses). Responses mediated by intrinsic processes are notoriously diffi- cult to predict, they can occur as slow environmental variables gradually erode the resilience of the system eventually resulting in threshold transitions between alternative stable states. Finding ways to identify, model and predict such complex ecosystem behavior has been identified as a priority research challenge for both ecology and paleoecology. The paleoecological record can play a role in understanding the processes behind abrupt ecological change because it enables the reconstruction of processes occurring over decadal-centennial timescales or longer. Therefore, paleoecological data can be used to identify the existence of ecological thresholds and to investigate the environmental processes that can lead to loss of resilience and abrupt transitions between alternate states. In addition, incidences of abrupt vegetation changes in the past can serve as palaeoecological model systems; analogues of abrupt dynamics which can be used to test theories surrounding ecological responses to climate change. Here, I present examples from a range of terrestrial ecosystems (Holocene environmental changes from a coastal lagoon in the Galapagos Islands; Northern European vegetation changes since the last deglaciation; the North American hemlock decline) demonstrating evidence of abrupt ecosystem change. For each system I present a set of statistical techniques tailored to distin- guish between extrinsic versus intrinsically mediated ecological responses. Examples are provided from both single sites (i.e. landscape scale) and multiple sites (regional-continental scale). These techniques provide a

Intrinsic, Functional, and Structural Properties of β-Thymosins and β-Thymosin/WH2 Domains in the Regulation and Coordination of Actin Self-Assembly Dynamics and Cytoskeleton Remodeling.

Science.gov (United States)

Renault, L

2016-01-01

β-Thymosins are a family of heat-stable multifunctional polypeptides that are expressed as small proteins of about 5kDa (~45 amino acids) almost exclusively in multicellular animals. They were first isolated from the thymus. As full-length or truncated polypeptides, they appear to stimulate a broad range of extracellular activities in various signaling pathways, including tissue repair and regeneration, inflammation, cell migration, and immune defense. However, their cell surface receptors and structural mechanisms of regulations in these multiple pathways remain still poorly understood. Besides their extracellular activities, they belong to a larger family of small, intrinsically disordered actin-binding domains called WH2/β-thymosin domains that have been identified in more than 1800 multidomain proteins found in different taxonomic domains of life and involved in various actin-based motile processes including cell morphogenesis, motility, adhesions, tissue development, intracellular trafficking, or pathogen infections. This review briefly surveys the main recent findings to understand how these small, intrinsically disordered but functional domains can interact with many unrelated partners and can thus integrate and coordinate various intracellular activities in actin self-assembly dynamics and cell signaling pathways linked to their cytoskeleton remodeling. © 2016 Elsevier Inc. All rights reserved.

Bidirectional 3.125 Gbps downstream / 2 Gbps upstream impulse radio ultrawide-band (UWB) over combined fiber and wireless link

DEFF Research Database (Denmark)

Jensen, Jesper Bevensee; Gibbon, Timothy Braidwood; Yu, Xianbin

2010-01-01

We demonstrate bidirectional fiber and wireless transmission of impulse radio ultra-wideband at 3.125 Gbps downstream and 2 Gbps upstream. After transmission over 50 km fiber and 1.85 m wireless link both signals are recovered without errors.......We demonstrate bidirectional fiber and wireless transmission of impulse radio ultra-wideband at 3.125 Gbps downstream and 2 Gbps upstream. After transmission over 50 km fiber and 1.85 m wireless link both signals are recovered without errors....

Diffusion of intrinsic localized modes by attractor hopping

International Nuclear Information System (INIS)

Meister, Matthias; Vazquez, Luis

2003-01-01

Propagating intrinsic localized modes exist in the damped-driven discrete sine-Gordon chain as attractors of the dynamics. The equations of motion of the system are augmented with Gaussian white noise in order to model the effects of temperature on the system. The noise induces random transitions between attracting configurations corresponding to opposite signs of the propagation velocity of the mode, which leads to a diffusive motion of the excitation. The Heun method is used to numerically generate the stochastic time-evolution of the configuration. We also present a theoretical model for the diffusion which contains two parameters, a transition probability θ and a delay time τ A . The mean value and the variance of the position of the intrinsic localized mode, obtained from simulations, can be fitted well with the predictions of our model, θ and τ A being used as parameters in the fit. After a transition period following the switching on of the noise, the variance shows a linear behaviour as a function of time and the mean value remains constant. An increase in the strength of the noise lowers the variance, leads to an increase in θ, a decrease in τ A and reduces the average distance a mode travels during the transition period

Diffusion of intrinsic localized modes by attractor hopping

Energy Technology Data Exchange (ETDEWEB)

Meister, Matthias [Dpto FIsica de la Materia Condensada, Facultad de Ciencias, Universidad de Zaragoza, 50009 Zaragoza (Spain); Instituto de Biocomputacion y FIsica de Sistemas Complejos, Universidad de Zaragoza, 50009 Zaragoza (Spain); Vazquez, Luis [Dpto Matematica Aplicada, Facultad de Informatica, Universidad Complutense de Madrid, 28040 Madrid (Spain); Centro de AstrobiologIa (CSIC-INTA), 28850 Torrejon de Ardoz (Spain)

2003-11-28

Propagating intrinsic localized modes exist in the damped-driven discrete sine-Gordon chain as attractors of the dynamics. The equations of motion of the system are augmented with Gaussian white noise in order to model the effects of temperature on the system. The noise induces random transitions between attracting configurations corresponding to opposite signs of the propagation velocity of the mode, which leads to a diffusive motion of the excitation. The Heun method is used to numerically generate the stochastic time-evolution of the configuration. We also present a theoretical model for the diffusion which contains two parameters, a transition probability {theta} and a delay time {tau}{sub A}. The mean value and the variance of the position of the intrinsic localized mode, obtained from simulations, can be fitted well with the predictions of our model, {theta} and {tau}{sub A} being used as parameters in the fit. After a transition period following the switching on of the noise, the variance shows a linear behaviour as a function of time and the mean value remains constant. An increase in the strength of the noise lowers the variance, leads to an increase in {theta}, a decrease in {tau}{sub A} and reduces the average distance a mode travels during the transition period.

The Neuroscience of Growth Mindset and Intrinsic Motivation

Directory of Open Access Journals (Sweden)

Betsy Ng

2018-01-01

Full Text Available Our actions can be triggered by intentions, incentives or intrinsic values. Recent neuroscientific research has yielded some results about the growth mindset and intrinsic motivation. With the advances in neuroscience and motivational studies, there is a global need to utilize this information to inform educational practice and research. Yet, little is known about the neuroscientific interplay between growth mindset and intrinsic motivation. This paper attempts to draw on the theories of growth mindset and intrinsic motivation, together with contemporary ideas in neuroscience, outline the potential for neuroscientific research in education. It aims to shed light on the relationship between growth mindset and intrinsic motivation in terms of supporting a growth mindset to facilitate intrinsic motivation through neural responses. Recent empirical research from the educational neuroscience perspective that provides insights into the interplay between growth mindset and intrinsic motivation will also be discussed.

Acoustic resonance spectroscopy intrinsic seals

International Nuclear Information System (INIS)

Olinger, C.T.; Burr, T.; Vnuk, D.R.

1994-01-01

We have begun to quantify the ability of acoustic resonance spectroscopy (ARS) to detect the removal and replacement of the lid of a simulated special nuclear materials drum. Conceptually, the acoustic spectrum of a container establishcs a baseline fingerprint, which we refer to as an intrinsic seal, for the container. Simply removing and replacing the lid changes some of the resonant frequencies because it is impossible to exactly duplicate all of the stress patterns between the lid and container. Preliminary qualitative results suggested that the ARS intrinsic seal could discriminate between cases where a lid has or has not been removed. The present work is directed at quantifying the utility of the ARS intrinsic seal technique, including the technique's sensitivity to ''nuisance'' effects, such as temperature swings, movement of the container, and placement of the transducers. These early quantitative tests support the potential of the ARS intrinsic seal application, but also reveal a possible sensitivity to nuisance effects that could limit environments or conditions under which the technique is effective

Comparative assessment of intrinsic mechanical stimuli on knee cartilage and compressed agarose constructs.

Science.gov (United States)

Completo, A; Bandeiras, C; Fonseca, F

2017-06-01

A well-established cue for improving the properties of tissue-engineered cartilage is mechanical stimulation. However, the explicit ranges of mechanical stimuli that correspond to favorable metabolic outcomes are elusive. Usually, these outcomes have only been associated with the applied strain and frequency, an oversimplification that can hide the fundamental relationship between the intrinsic mechanical stimuli and the metabolic outcomes. This highlights two important key issues: the firstly is related to the evaluation of the intrinsic mechanical stimuli of native cartilage; the second, assuming that the intrinsic mechanical stimuli will be important, deals with the ability to replicate them on the tissue-engineered constructs. This study quantifies and compares the volume of cartilage and agarose subjected to a given magnitude range of each intrinsic mechanical stimulus, through a numerical simulation of a patient-specific knee model coupled with experimental data of contact during the stance phase of gait, and agarose constructs under direct-dynamic compression. The results suggest that direct compression loading needs to be parameterized with time-dependence during the initial culture period in order to better reproduce each one of the intrinsic mechanical stimuli developed in the patient-specific cartilage. A loading regime which combines time periods of low compressive strain (5%) and frequency (0.5Hz), in order to approach the maximal principal strain and fluid velocity stimulus of the patient-specific cartilage, with time periods of high compressive strain (20%) and frequency (3Hz), in order to approach the pore pressure values, may be advantageous relatively to a single loading regime throughout the full culture period. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

Abundance of intrinsic structural disorder in the histone H1 subtypes.

Science.gov (United States)

Kowalski, Andrzej

2015-12-01

The intrinsically disordered proteins consist of partially structured regions linked to the unstructured stretches, which consequently form the transient and dynamic conformational ensembles. They undergo disorder to order transition upon binding their partners. Intrinsic disorder is attributed to histones H1, perceived as assemblers of chromatin structure and the regulators of DNA and proteins activity. In this work, the comparison of intrinsic disorder abundance in the histone H1 subtypes was performed both by the analysis of their amino acid composition and by the prediction of disordered stretches, as well as by identifying molecular recognition features (MoRFs) and ANCHOR protein binding regions (APBR) that are responsible for recognition and binding. Both human and model organisms-animals, plants, fungi and protists-have H1 histone subtypes with the properties typical of disordered state. They possess a significantly higher content of hydrophilic and charged amino acid residues, arranged in the long regions, covering over half of the whole amino acid residues in chain. Almost complete disorder corresponds to histone H1 terminal domains, including MoRFs and ANCHOR. Those motifs were also identified in a more ordered histone H1 globular domain. Compared to the control (globular and fibrous) proteins, H1 histones demonstrate the increased folding rate and a higher proportion of low-complexity segments. The results of this work indicate that intrinsic disorder is an inherent structural property of histone H1 subtypes and it is essential for establishing a protein conformation which defines functional outcomes affecting on DNA- and/or partner protein-dependent cell processes. Copyright © 2015 Elsevier Ltd. All rights reserved.

Bidirectional modulation of taste aversion extinction by insular cortex LTP and LTD.

Science.gov (United States)

Rodríguez-Durán, Luis F; Martínez-Moreno, Araceli; Escobar, Martha L

2017-07-01

The history of activity of a given neuron has been proposed to bidirectionally influence its future response to synaptic inputs. In particular, induction of synaptic plasticity expressions such as long-term potentiation (LTP) and long-term depression (LTD) modifies the performance of several behavioral tasks. Our previous studies in the insular cortex (IC), a neocortical region that has been related to acquisition and retention of conditioned taste aversion (CTA), have demonstrated that induction of LTP in the basolateral amygdaloid nucleus (Bla)-IC pathway before CTA training enhances the retention of this task. In addition, we reported that CTA training triggers a persistent impairment in the ability to induce in vivo LTP in the IC. The aim of the present study was to investigate whether LTD can be induced in the Bla-IC projection in vivo, as well as, whether the extinction of CTA is bidirectionally modified by previous synaptic plasticity induction in this pathway. Thus, rats received 900 train pulses (five 250μs pulses at 250Hz) delivered at 1Hz in the Bla-IC projection in order to induce LTD or 10 trains of 100Hz/1s with an intertrain interval of 20s in order to induce LTP. Seven days after surgery, rats were trained in the CTA task including the extinction trials. Our results show that the Bla-IC pathway is able to express in vivo LTD in an N-Methyl-D-aspartate (NMDA) receptor-dependent manner. Induction of LTD in the Bla-IC projection previous to CTA training facilitates the extinction of this task. Conversely, LTP induction enhances CTA retention. The present results show the bidirectional modulation of CTA extinction in response to IC-LTP and LTD, providing evidence of the homeostatic adaptation of taste learning. Copyright © 2016 Elsevier Inc. All rights reserved.

Optimal Design of a Push-Pull-Forward Half-Bridge (PPFHB) Bidirectional DC–DC Converter With Variable Input Voltage

DEFF Research Database (Denmark)

Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael A. E.

2012-01-01

This paper presents a low-cost bidirectional isolated dc–dc converte, derived from dual-active-bridge converter for the power sources with variable output voltage like supercapacitors. The proposed converter consists of push-pull-forward circuit half-bridge circuit (PPFHB) and a high-frequency tr......This paper presents a low-cost bidirectional isolated dc–dc converte, derived from dual-active-bridge converter for the power sources with variable output voltage like supercapacitors. The proposed converter consists of push-pull-forward circuit half-bridge circuit (PPFHB) and a high...

Bidirectional Associations between Parenting Practices and Conduct Problems in Boys from Childhood to Adolescence: The Moderating Effect of Age and African-American Ethnicity

Science.gov (United States)

Pardini, Dustin A.; Fite, Paula J.; Burke, Jeffrey D.

2008-01-01

This study examined the bidirectional relationship between parent and teacher reported conduct problems in youth and parenting practices using a longitudinal sample of boys assessed from 6 to 16 years of age. Analyses tested whether these bidirectional associations changed across development and whether the nature of these associations varied…

Optimization of Bi-Directional Flyback Converter for a High Voltage Capacitor Charging Application

DEFF Research Database (Denmark)

Thummala, Prasanth; Schneider, Henrik; Zhang, Zhe

2014-01-01

This paper presents an optimization technique for a flyback converter with a bidirectional energy transfer. The main goal is to optimize the converter for driving an incremental dielectric electro active polymer actuator, which must be charged and discharged from 0 V to 2500 V DC, supplied from...

Finite-Time Stability for Fractional-Order Bidirectional Associative Memory Neural Networks with Time Delays

Science.gov (United States)

Xu, Chang-Jin; Li, Pei-Luan; Pang, Yi-Cheng

2017-02-01

This paper is concerned with fractional-order bidirectional associative memory (BAM) neural networks with time delays. Applying Laplace transform, the generalized Gronwall inequality and estimates of Mittag-Leffler functions, some sufficient conditions which ensure the finite-time stability of fractional-order bidirectional associative memory neural networks with time delays are obtained. Two examples with their simulations are given to illustrate the theoretical findings. Our results are new and complement previously known results. Supported by National Natural Science Foundation of China under Grant Nos.~61673008, 11261010, 11101126, Project of High-Level Innovative Talents of Guizhou Province ([2016]5651), Natural Science and Technology Foundation of Guizhou Province (J[2015]2025 and J[2015]2026), 125 Special Major Science and Technology of Department of Education of Guizhou Province ([2012]011) and Natural Science Foundation of the Education Department of Guizhou Province (KY[2015]482)

Bidirectional associations between activity-related parenting practices, and child physical activity, sedentary screen-based behavior and body mass index: a longitudinal analysis.

Science.gov (United States)

Sleddens, Ester F C; Gubbels, Jessica S; Kremers, Stef P J; van der Plas, Eline; Thijs, Carel

2017-07-06

of physical activity and child physical activity. Bidirectional parent-child interaction should be considered in future research in order to properly inform parenting-related intervention programs aimed at preventing or treating childhood overweight or obesity. System dynamic methods to explore the existence of reinforcing or balancing loops are needed in this regard.

Bidirectional Texture Function Modeling: State of the Art Survey

Czech Academy of Sciences Publication Activity Database

Filip, Jiří; Haindl, Michal

2009-01-01

Roč. 31, č. 11 (2009), s. 1921-1940 ISSN 0162-8828 R&D Projects: GA MŠk 1M0572; GA ČR GA102/08/0593; GA AV ČR 1ET400750407 Grant - others:EC Marie Curie(BE) 41358; GA MŠk(CZ) 2C06019 Institutional research plan: CEZ:AV0Z10750506 Keywords : BTF * surface texture * 3D texture Subject RIV: BD - Theory of Information Impact factor: 4.378, year: 2009 http://library.utia.cas.cz/separaty/2009/RO/filip-bidirectional texture function modeling state of the art survey.pdf

Soft switching bidirectional DC-DC converter for ultracapacitor-batteries interface

International Nuclear Information System (INIS)

Adib, Ehsan; Farzanehfard, Hosein

2009-01-01

In this paper a new soft switching bidirectional DC-DC converter is introduced which can be applied as the interface circuit between ultracapacitors and batteries or fuel cells. All semiconductor devices in the proposed converter are soft switched while the control circuit remains PWM. Due to achieved soft switching condition, the energy conversion through the proposed converter is highly efficient. The proposed converter is analyzed and a prototype converter is implemented. The presented experimental results confirm the theoretical analysis.

Bi-directional LSTM Recurrent Neural Network for Chinese Word Segmentation

OpenAIRE

Yao, Yushi; Huang, Zheng

2016-01-01

Recurrent neural network(RNN) has been broadly applied to natural language processing(NLP) problems. This kind of neural network is designed for modeling sequential data and has been testified to be quite efficient in sequential tagging tasks. In this paper, we propose to use bi-directional RNN with long short-term memory(LSTM) units for Chinese word segmentation, which is a crucial preprocess task for modeling Chinese sentences and articles. Classical methods focus on designing and combining...

Bidirectional Relations between Temperament and Parenting Styles in Chinese Children

OpenAIRE

Lee, Erica H.; Zhou, Qing; Eisenberg, Nancy; Wang, Yun

2012-01-01

The present study examined bidirectional relations between child temperament and parenting styles in a sample (n = 425) of Chinese children during elementary school period (age range = 6 to 9 years at Wave 1). Using two waves (3.8 years apart) of longitudinal data, we tested two hypotheses: (1) whether child temperament (effortful control and anger/frustration) at Wave 1 predicts parenting styles (authoritative and authoritarian parenting) at Wave 2, controlling for Wave 1 parenting; and (2) ...

Convergence analysis of stochastic hybrid bidirectional associative memory neural networks with delays

International Nuclear Information System (INIS)

Wan Li; Zhou Qinghua

2007-01-01

The stability property of stochastic hybrid bidirectional associate memory (BAM) neural networks with discrete delays is considered. Without assuming the symmetry of synaptic connection weights and the monotonicity and differentiability of activation functions, the delay-independent sufficient conditions to guarantee the exponential stability of the equilibrium solution for such networks are given by using the nonnegative semimartingale convergence theorem

Convergence analysis of stochastic hybrid bidirectional associative memory neural networks with delays

Science.gov (United States)

Wan, Li; Zhou, Qinghua

2007-10-01

The stability property of stochastic hybrid bidirectional associate memory (BAM) neural networks with discrete delays is considered. Without assuming the symmetry of synaptic connection weights and the monotonicity and differentiability of activation functions, the delay-independent sufficient conditions to guarantee the exponential stability of the equilibrium solution for such networks are given by using the nonnegative semimartingale convergence theorem.

Dynamic pricing based on a cloud computing framework to support the integration of renewable energy sources

Directory of Open Access Journals (Sweden)

Rajeev Thankappan Nair

2014-12-01

Full Text Available Integration of renewable energy sources into the electric grid in the domestic sector results in bidirectional energy flow from the supply side of the consumer to the grid. Traditional pricing methods are difficult to implement in such a situation of bidirectional energy flow and they face operational challenges on the application of price-based demand side management programme because of the intermittent characteristics of renewable energy sources. In this study, a dynamic pricing method using real-time data based on a cloud computing framework is proposed to address the aforementioned issues. The case study indicates that the dynamic pricing captures the variation of energy flow in the household. The dynamic renewable factor introduced in the model supports consumer oriented pricing. A new method is presented in this study to determine the appropriate level of photovoltaic (PV penetration in the distribution system based on voltage stability aspect. The load flow study result for the electric grid in Kerala, India, indicates that the overvoltage caused by various PV penetration levels up to 33% is within the voltage limits defined for distribution feeders. The result justifies the selected level of penetration.

Clustering of Nuclei in Multinucleated Hyphae Is Prevented by Dynein-Driven Bidirectional Nuclear Movements and Microtubule Growth Control in Ashbya gossypii ▿ †

Science.gov (United States)

Grava, Sandrine; Keller, Miyako; Voegeli, Sylvia; Seger, Shanon; Lang, Claudia; Philippsen, Peter

2011-01-01

During filamentous fungus development, multinucleated hyphae employ a system for long-range nuclear migration to maintain an equal nuclear density. A decade ago the microtubule motor dynein was shown to play a central role in this process. Previous studies with Ashbya gossypii revealed extensive bidirectional movements and bypassings of nuclei, an autonomous cytoplasmic microtubule (cMT) cytoskeleton emanating from each nucleus, and pulling of nuclei by sliding of cMTs along the cortex. Here, we show that dynein is the sole motor for bidirectional movements and bypassing because these movements are concomitantly decreased in mutants carrying truncations of the dynein heavy-chain DYN1 promoter. The dynactin component Jnm1, the accessory proteins Dyn2 and Ndl1, and the potential dynein cortical anchor Num1 are also involved in the dynamic distribution of nuclei. In their absence, nuclei aggregate to different degrees, whereby the mutants with dense nuclear clusters grow extremely long cMTs. As in budding yeast, we found that dynein is delivered to cMT plus ends, and its activity or processivity is probably controlled by dynactin and Num1. Together with its role in powering nuclear movements, we propose that dynein also plays (directly or indirectly) a role in the control of cMT length. Those combined dynein actions prevent nuclear clustering in A. gossypii and thus reveal a novel cellular role for dynein. PMID:21642510

Crowding out intrinsic motivation in the public sector

OpenAIRE

Georgellis, Y; Iossa, E; Tabvuma, V

2011-01-01

Employing intrinsically motivated individuals has been proposed as a means of improving public sector performance. In this article, we investigate whether intrinsic motivation affects the sorting of employees between the private and the public sectors, paying particular attention to whether extrinsic rewards crowd out intrinsic motivation. Using British longitudinal data, we find that individuals are attracted to the public sector by the intrinsic rather than the extrinsic rewards that the se...

Dynamical calculation of nuclear temperature

International Nuclear Information System (INIS)

Zheng Yuming

1998-01-01

A new dynamical approach for measuring the temperature of a Hamiltonian dynamical system in the microcanonical ensemble of thermodynamics is presented. It shows that under the hypothesis of ergodicity the temperature can be computed as a time average of a function on the energy surface. This method not only yields an efficient computational approach for determining the temperature, but also provides an intrinsic link between dynamical system theory and the statistical mechanics of Hamiltonian system

Detailed validation of the bidirectional effect in various Case 1 waters for application to ocean color imagery

Directory of Open Access Journals (Sweden)

K. J. Voss

2007-09-01

Full Text Available The radiance viewed from the ocean depends on the illumination and viewing geometry along with the water properties, and this variation is called the bidirectional effect. This bidirectional effect depends on the inherent optical properties of the water, including the volume scattering function, and is important when comparing data from different satellite sensors. The current model of f/Q, which contains the bidirectional effect, by Morel et al. (2002 depends on modeled, not measured, water parameters, thus must be carefully validated. In this paper we combined upwelling radiance distribution data from several cruises, in varied water types and with a wide range of solar zenith angles. We compared modeled and measured L_view/L_nadir and found that the average difference between the model and data was less than 0.01, while the RMS difference between the model and data was on the order of 0.02–0.03. This is well within the statistical noise of the data, which was on the order of 0.04–0.05, due to environmental noise sources such as wave focusing.

Intrinsic Versus Extrinsic Goal Contents in Self-Determination Theory: Another Look at the Quality of Academic Motivation

Science.gov (United States)

Vansteenkiste, Maarten; Lens, Willy; Deci, Edward L.

2006-01-01

Examination of motivational dynamics in academic contexts within self-determination theory has centered primarily around both the motives (initially intrinsic vs. extrinsic, later autonomous vs. controlled) that regulate learners' study behavior and the contexts that promote or hinder these regulations. Less attention has been paid to the goal…

Bi-directionally protective communication between neurons and astrocytes under ischemia.

Science.gov (United States)

Wu, Xiao-Mei; Qian, Christopher; Zhou, Yu-Fu; Yan, Yick-Chun; Luo, Qian-Qian; Yung, Wing-Ho; Zhang, Fa-Li; Jiang, Li-Rong; Qian, Zhong Ming; Ke, Ya

2017-10-01

The extensive existing knowledge on bi-directional communication between astrocytes and neurons led us to hypothesize that not only ischemia-preconditioned (IP) astrocytes can protect neurons but also IP neurons protect astrocytes from lethal ischemic injury. Here, we demonstrated for the first time that neurons have a significant role in protecting astrocytes from ischemic injury. The cultured medium from IP neurons (IPcNCM) induced a remarkable reduction in LDH and an increase in cell viability in ischemic astrocytes in vitro. Selective neuronal loss by kainic acid injection induced a significant increase in apoptotic astrocyte numbers in the brain of ischemic rats in vivo. Furthermore, TUNEL analysis, DNA ladder assay, and the measurements of ROS, GSH, pro- and anti-apoptotic factors, anti-oxidant enzymes and signal molecules in vitro and/or in vivo demonstrated that IP neurons protect astrocytes by an EPO-mediated inhibition of pro-apoptotic signals, activation of anti-apoptotic proteins via the P13K/ERK/STAT5 pathways and activation of anti-oxidant proteins via up-regulation of anti-oxidant enzymes. We demonstrated the existence of astro-protection by IP neurons under ischemia and proposed that the bi-directionally protective communications between cells might be a common activity in the brain or peripheral organs under most if not all pathological conditions. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Bi-directionally protective communication between neurons and astrocytes under ischemia

Directory of Open Access Journals (Sweden)

Xiao-Mei Wu

2017-10-01

Full Text Available The extensive existing knowledge on bi-directional communication between astrocytes and neurons led us to hypothesize that not only ischemia-preconditioned (IP astrocytes can protect neurons but also IP neurons protect astrocytes from lethal ischemic injury. Here, we demonstrated for the first time that neurons have a significant role in protecting astrocytes from ischemic injury. The cultured medium from IP neurons (IPcNCM induced a remarkable reduction in LDH and an increase in cell viability in ischemic astrocytes in vitro. Selective neuronal loss by kainic acid injection induced a significant increase in apoptotic astrocyte numbers in the brain of ischemic rats in vivo. Furthermore, TUNEL analysis, DNA ladder assay, and the measurements of ROS, GSH, pro- and anti-apoptotic factors, anti-oxidant enzymes and signal molecules in vitro and/or in vivo demonstrated that IP neurons protect astrocytes by an EPO-mediated inhibition of pro-apoptotic signals, activation of anti-apoptotic proteins via the P13K/ERK/STAT5 pathways and activation of anti-oxidant proteins via up-regulation of anti-oxidant enzymes. We demonstrated the existence of astro-protection by IP neurons under ischemia and proposed that the bi-directionally protective communications between cells might be a common activity in the brain or peripheral organs under most if not all pathological conditions.

Bidirectional psychoneuroimmune interactions in the early postpartum period influence risk of postpartum depression.

Science.gov (United States)

Corwin, Elizabeth J; Pajer, Kathleen; Paul, Sudeshna; Lowe, Nancy; Weber, Mary; McCarthy, Donna O

2015-10-01

More than 500,000 U.S. women develop postpartum depression (PPD) annually. Although psychosocial risks are known, the underlying biology remains unclear. Dysregulation of the immune inflammatory response and the hypothalamic-pituitary-adrenal (HPA) axis are associated with depression in other populations. While significant research on the contribution of these systems to the development of PPD has been conducted, results have been inconclusive. This is partly because few studies have focused on whether disruption in the bidirectional and dynamic interaction between the inflammatory response and the HPA axis together influence PPD. In this study, we tested the hypothesis that disruption in the inflammatory-HPA axis bidirectional relationship would increase the risk of PPD. Plasma pro- and anti-inflammatory cytokines were measured in women during the 3rd trimester of pregnancy and on Days 7 and 14, and Months 1, 2, 3, and 6 after childbirth. Saliva was collected 5 times the day preceding blood draws for determination of cortisol area under the curve (AUC) and depressive symptoms were measured using the Edinburgh Postpartum Depression Survey (EPDS). Of the 152 women who completed the EPDS, 18% were depressed according to EDPS criteria within the 6months postpartum. Cortisol AUC was higher in symptomatic women on Day 14 (p=.017). To consider the combined effects of cytokines and cortisol on predicting symptoms of PPD, a multiple logistic regression model was developed that included predictors identified in bivariate analyses to have an effect on depressive symptoms. Results indicated that family history of depression, day 14 cortisol AUC, and the day 14 IL8/IL10 ratio were significant predictors of PPD symptoms. One unit increase each in the IL8/IL10 ratio and cortisol AUC resulted in 1.50 (p=0.06) and 2.16 (p=0.02) fold increases respectively in the development of PPD. Overall, this model correctly classified 84.2% of individuals in their respective groups. Findings

Opposing Effects of Intrinsic Conductance and Correlated Synaptic Input on V-Fluctuations during Network Activity

DEFF Research Database (Denmark)

Kolind, Jens; Hounsgaard, Jørn Dybkjær; Berg, Rune W

2012-01-01

Neurons often receive massive concurrent bombardment of synaptic inhibition and excitation during functional network activity. This increases membrane conductance and causes fluctuations in membrane potential (V(m)) and spike timing. The conductance increase is commonly attributed to synaptic....... If the spikes arrive at random times the changes in synaptic conductance are therefore stochastic and rapid during intense network activity. In comparison, sub-threshold intrinsic conductances vary smoothly in time. In the present study this discrepancy is investigated using two conductance-based models: a (1...... conductance, but also includes the intrinsic conductances recruited during network activity. These two sources of conductance have contrasting dynamic properties at sub-threshold membrane potentials. Synaptic transmitter gated conductance changes abruptly and briefly with each presynaptic action potential...

Three-port bi-directional converter for electric vehicles: focus on high-frequency coaxial transformer

NARCIS (Netherlands)

Waltrich, G.; Duarte, J.L.; Hendrix, M.A.M.; Paulides, J.J.H.

2010-01-01

A bi-directional multi-port converter can accommodate various energy storages and sources. Therefore, a multiport converter will be a good candidate for application as a future universal converter for (hybrid) electrical vehicles or local distribution systems. The main design challenge of the

Coordinated Operation of the Electricity and Natural Gas Systems with Bi-directional Energy Conversion

DEFF Research Database (Denmark)

Zeng, Qing; Zhang, Baohua; Fang, Jiakun

2017-01-01

A coordinated operation of the natural gas and electricity network with bi-directional energy conversion is expected to accommodate high penetration levels of renewables. This work focuses on the unified optimal operation of the integrated natural gas and electricity system considering the network...

Soft switching bidirectional DC-DC converter for ultracapacitor-batteries interface

Energy Technology Data Exchange (ETDEWEB)

Adib, Ehsan; Farzanehfard, Hosein [Dept. of Electrical and Computer Engineering, Isfahan Univ. of Technology (Iran)

2009-12-15

In this paper a new soft switching bidirectional DC-DC converter is introduced which can be applied as the interface circuit between ultracapacitors and batteries or fuel cells. All semiconductor devices in the proposed converter are soft switched while the control circuit remains PWM. Due to achieved soft switching condition, the energy conversion through the proposed converter is highly efficient. The proposed converter is analyzed and a prototype converter is implemented. The presented experimental results confirm the theoretical analysis. (author)

On uniform resampling and gaze analysis of bidirectional texture functions

Czech Academy of Sciences Publication Activity Database

Filip, Jiří; Chantler, M.J.; Haindl, Michal

2009-01-01

Roč. 6, č. 3 (2009), s. 1-15 ISSN 1544-3558 R&D Projects: GA MŠk 1M0572; GA ČR GA102/08/0593 Grant - others:EC Marie Curie(BE) 41358 Institutional research plan: CEZ:AV0Z10750506 Keywords : BTF * texture * eye tracking Subject RIV: BD - Theory of Information Impact factor: 1.447, year: 2009 http://library.utia.cas.cz/separaty/2009/RO/haindl-on uniform resampling and gaze analysis of bidirectional texture functions.pdf

Bidirectional Relations of Impulsive Personality and Alcohol Use Across Three Waves of Data Collection.

Science.gov (United States)

Kaiser, Alison J; Davis, Heather A; Milich, Richard; Smith, Gregory T; Charnigo, Richard

2018-06-11

To explore the bidirectional relations between alcohol use and three impulsive personality traits, to advance understanding of risk processes. 525 college students (mean age = 18.95 years) recruited in August 2008 and 2009 and followed up annually for three years. Personality and past/current substance use were assessed. T2 sensation seeking mediated the predictive relationship between T1 and T3 alcohol use, and T2 alcohol use mediated the predictive relationship between T1 and T3 sensation seeking. In addition, T2 alcohol problems mediated the predictive relationship between T1 alcohol use and T3 negative urgency. Findings support a bidirectional relationship between sensation seeking and alcohol use, and drinking anticipates drinking problems, which predict increases in negative urgency. For some individuals, there appears to be an ongoing process of increased risk in the form of increases in both drinking and high-risk personality traits.

Defining intrinsic vs. extrinsic atopic dermatitis.

Science.gov (United States)

Karimkhani, Chante; Silverberg, Jonathan I; Dellavalle, Robert P

2015-06-16

Atopic dermatitis (AD) is a chronic, relapsing inflammatory skin condition characterized by eczematous lesions, i.e. ill-demarcated erythematous patches and plaques. AD is commonly associated with elevated immunoglobulin E (IgE) and atopic disorders, such as asthma, hay fever, and food allergies. Rackemann and Mallory were some of the first to distinguish between asthma based on the presence ("extrinsic") or absence ("intrinsic") of allergy. This distinction has subsequently been applied to AD based on the presence ("extrinsic") or absence ("intrinsic") of increased IgE and atopic disease. Although the distinction between intrinsic and extrinsic AD is widely used, it remains controversial.

Intrinsic Tunneling in Phase Separated Manganites

Science.gov (United States)

Singh-Bhalla, G.; Selcuk, S.; Dhakal, T.; Biswas, A.; Hebard, A. F.

2009-02-01

We present evidence of direct electron tunneling across intrinsic insulating regions in submicrometer wide bridges of the phase-separated ferromagnet (La,Pr,Ca)MnO3. Upon cooling below the Curie temperature, a predominantly ferromagnetic supercooled state persists where tunneling across the intrinsic tunnel barriers (ITBs) results in metastable, temperature-independent, high-resistance plateaus over a large range of temperatures. Upon application of a magnetic field, our data reveal that the ITBs are extinguished resulting in sharp, colossal, low-field resistance drops. Our results compare well to theoretical predictions of magnetic domain walls coinciding with the intrinsic insulating phase.

Intrinsic-extrinsic factors in sport motivation.

Science.gov (United States)

Pedersen, Darhl M

2002-10-01

Participants were 83 students (36 men and 47 women). 10 intrinsic-extrinsic factors involved in sport motivation were obtained. The factors were generated from items obtained from the participants rather than items from the experimenter. This was done to avoid the possible influence of preconceptions on the part of the experimenter regarding what the final dimensions may be. Obtained motivational factors were Social Reinforcement, Fringe Benefits, Fame and Fortune, External Forces, Proving Oneself, Social Benefits, Mental Enrichment, Expression of Self, Sense of Accomplishment, and Self-enhancement. Each factor was referred to an intrinsic-extrinsic dimension to describe its relative position on that dimension. The order of the factors as listed indicates increasing intrinsic motivation. i.e., the first four factors were rated in the extrinsic range, whereas the remaining six were rated to be in the intrinsic range. Next, the participants rated the extent to which each of the various factors was involved in their decision to participate in sport activities. The pattern of use of the motivational factors was the same for both sexes except that men indicated greater use of the Fringe Benefits factor. Overall, the more intrinsic a sport motivation factor was rated, the more likely it was to be rated as a factor in actual sport participation.

High Efficient Bidirectional Battery Converter for residential PV Systems

DEFF Research Database (Denmark)

Pham, Cam; Kerekes, Tamas; Teodorescu, Remus

2012-01-01

Photovoltaic (PV) installation is suited for the residential environment and the generation pattern follows the distribution of residential power consumption in daylight hours. In the cases of unbalance between generation and demand, the Smart PV with its battery storage can absorb or inject...... the power to balance it. High efficient bidirectional converter for the battery storage is required due high system cost and because the power is processed twice. A 1.5kW prototype is designed and built with CoolMOS and SiC diodes, >;95% efficiency has been obtained with 200 kHz hard switching....

Bidirectional Quantum Secure Direct Communication Network Protocol with Hyperentanglement

International Nuclear Information System (INIS)

Gu Bin; Chen Yulin; Huang Yugai; Fang Xia

2011-01-01

We propose a bidirectional quantum secure direct communication (QSDC) network protocol with the hyperentanglment in both the spatial-mode ad the polarization degrees of freedom of photon pairs which can in principle be produced with a beta barium borate crystal. The secret message can be encoded on the photon pairs with unitary operations in these two degrees of freedom independently. Compared with other QSDC network protocols, our QSDC network protocol has a higher capacity as each photon pair can carry 4 bits of information. Also, we discuss the security of our QSDC network protocol and its feasibility with current techniques. (general)

Bidirectional relationship between time preference and adolescent smoking and alcohol use: Evidence from longitudinal data.

Science.gov (United States)

Do, Young Kyung; Shin, Eunhae

2017-07-01

Scholarly interest in time preference as a potential predictor of risky health behaviors in adolescents has increased in recent years. However, most of the existing literature is limited due to the exclusive reliance on cross-sectional data, precluding the possibility of establishing the direction of causality. Using longitudinal data from the Korea Youth Panel Survey (2003-7), which followed up a nationally representative sample of 3449 adolescents aged 14years for five years, this study examines a bidirectional relationship between time preference and smoking and drinking behaviors among adolescents. We used discrete time hazard models of smoking and drinking initiation as a function of time preference measured at the baseline and fixed-effects ordered logit model of time preference, respectively. Our measure of time preference was derived from the survey question on a hypothetical choice between immediate enjoyment today and likely higher scores on an exam tomorrow. The overall results provide evidence on the bidirectional relationship; that is, higher time discounting (i.e., greater relative preference for present utility over future utility) results in an increased risk of engaging in smoking and drinking, and conversely, adopting such behaviors leads to a higher discount rate. The bidirectional relationship may function as a mechanism for adolescents to engage in increased smoking and drinking or additional negative health behaviors via gateway effects, strengthening the case for preventing the initiation of risky health behaviors among adolescents. Copyright © 2017 Elsevier Ltd. All rights reserved.

Experiences matter: Positive emotions facilitate intrinsic motivation

OpenAIRE

Løvoll, Helga Synnevåg; Røysamb, Espen; Vittersø, Joar

2017-01-01

This paper has two major aims. First, to investigate how positive emotions and intrinsic motivation affect each other over time. Second, to test the effect of positive emotions and intrinsic motivation on subsequent educational choices. Through two ordinary study semesters, 64 sport students in Norway reported on their intrinsic motivation for outdoor activities (twice) as well as positive emotions after two three-day outdoor events (four times). Next autumn, students study choice was collect...

Experiences matter: Positive emotions facilitate intrinsic motivation

OpenAIRE

Løvoll, Helga Synnevåg; Røysamb, Espen; Vittersø, Joar

2017-01-01

https://doi.org/10.1080/23311908.2017.1340083 This paper has two major aims. First, to investigate how positive emotions and intrinsic motivation affect each other over time. Second, to test the effect of positive emotions and intrinsic motivation on subsequent educational choices. Through two ordinary study semesters, 64 sport students in Norway reported on their intrinsic motivation for outdoor activities (twice) as well as positive emotions after two three-day outdoor e...

Intrinsic and extrinsic geometry of random surfaces

International Nuclear Information System (INIS)

Jonsson, T.

1992-01-01

We prove that the extrinsic Hausdorff dimension is always greater than or equal to the intrinsic Hausdorff dimension in models of triangulated random surfaces with action which is quadratic in the separation of vertices. We furthermore derive a few naive scaling relations which relate the intrinsic Hausdorff dimension to other critical exponents. These relations suggest that the intrinsic Hausdorff dimension is infinite if the susceptibility does not diverge at the critical point. (orig.)

Bidirectional-Convolutional LSTM Based Spectral-Spatial Feature Learning for Hyperspectral Image Classification

Directory of Open Access Journals (Sweden)

Qingshan Liu

2017-12-01

Full Text Available This paper proposes a novel deep learning framework named bidirectional-convolutional long short term memory (Bi-CLSTM network to automatically learn the spectral-spatial features from hyperspectral images (HSIs. In the network, the issue of spectral feature extraction is considered as a sequence learning problem, and a recurrent connection operator across the spectral domain is used to address it. Meanwhile, inspired from the widely used convolutional neural network (CNN, a convolution operator across the spatial domain is incorporated into the network to extract the spatial feature. In addition, to sufficiently capture the spectral information, a bidirectional recurrent connection is proposed. In the classification phase, the learned features are concatenated into a vector and fed to a Softmax classifier via a fully-connected operator. To validate the effectiveness of the proposed Bi-CLSTM framework, we compare it with six state-of-the-art methods, including the popular 3D-CNN model, on three widely used HSIs (i.e., Indian Pines, Pavia University, and Kennedy Space Center. The obtained results show that Bi-CLSTM can improve the classification performance by almost 1.5 % as compared to 3D-CNN.

Intrinsic Motivation: An Overlooked Component for Student Success

Science.gov (United States)

Augustyniak, Robert A.; Ables, Adrienne Z.; Guilford, Philip; Lujan, Heidi L.; Cortright, Ronald N.; DiCarlo, Stephen E.

2016-01-01

Intrinsic motivation to learn involves engaging in learning opportunities because they are seen as enjoyable, interesting, or relevant to meeting one's core psychological needs. As a result, intrinsic motivation is associated with high levels of effort and task performance. Students with greater levels of intrinsic motivation demonstrate strong…

The value of nature: Economic, intrinsic, or both?

Science.gov (United States)

There has been a long standing argument that ecosystems have intrinsic value and therefore there is no need to put a price tag on Mother Nature. The concept of intrinsic value reflects the perspective that nature has value in its own right, independent of human uses. Intrinsic va...

Nuclear intrinsic vorticity and its coupling to global rotations

International Nuclear Information System (INIS)

Mikhailov, I.N.; Quentin, P.; Samsoen, D.

1997-01-01

Important collective modes which are generally neglected within current descriptions of nuclear excitations in terms of fluid dynamics, are studied here. The intrinsic vortical modes are defined in a general way from which a specific mode, both simple and versatile enough, is particularly discussed. In this paper the main emphasis is made on the coupling of the chosen intrinsic mode to the rotation of the nuclear principal axes frame with respect to the laboratory system. A semi-quantal description of such excitations is proposed which is a generalization of the so-called routhian approach of global rotations. The results of a semiclassical treatment of the corresponding variational problem are presented. A simple mean field approach where the one-body potential is mocked up by a harmonic oscillator is discussed in a somewhat detailed fashion. The broad range of validity of a quadratic approximation for the collective energy in terms of the relevant angular velocities, is hinted from the previous simple model approach. Some general consequences of the latter are then drawn which have bearing on some possible fingerprints for the existence of such excitations, as the staggering phenomenon observed in gamma transition energies in some superdeformed states and the occurrence of identical rotational bands in neighbouring nuclei. (orig.)

Changing the Environment Based on Empowerment as Intrinsic Motivation

Directory of Open Access Journals (Sweden)

Christoph Salge

2014-05-01

Full Text Available One aspect of intelligence is the ability to restructure your own environment so that the world you live in becomes more beneficial to you. In this paper we investigate how the information-theoretic measure of agent empowerment can provide a task-independent, intrinsic motivation to restructure the world. We show how changes in embodiment and in the environment change the resulting behaviour of the agent and the artefacts left in the world. For this purpose, we introduce an approximation of the established empowerment formalism based on sparse sampling, which is simpler and significantly faster to compute for deterministic dynamics. Sparse sampling also introduces a degree of randomness into the decision making process, which turns out to beneficial for some cases. We then utilize the measure to generate agent behaviour for different agent embodiments in a Minecraft-inspired three dimensional block world. The paradigmatic results demonstrate that empowerment can be used as a suitable generic intrinsic motivation to not only generate actions in given static environments, as shown in the past, but also to modify existing environmental conditions. In doing so, the emerging strategies to modify an agent’s environment turn out to be meaningful to the specific agent capabilities, i.e., de facto to its embodiment.

Genetic recombination is associated with intrinsic disorder in plant proteomes.

Science.gov (United States)

Yruela, Inmaculada; Contreras-Moreira, Bruno

2013-11-09

Intrinsically disordered proteins, found in all living organisms, are essential for basic cellular functions and complement the function of ordered proteins. It has been shown that protein disorder is linked to the G + C content of the genome. Furthermore, recent investigations have suggested that the evolutionary dynamics of the plant nucleus adds disordered segments to open reading frames alike, and these segments are not necessarily conserved among orthologous genes. In the present work the distribution of intrinsically disordered proteins along the chromosomes of several representative plants was analyzed. The reported results support a non-random distribution of disordered proteins along the chromosomes of Arabidopsis thaliana and Oryza sativa, two model eudicot and monocot plant species, respectively. In fact, for most chromosomes positive correlations between the frequency of disordered segments of 30+ amino acids and both recombination rates and G + C content were observed. These analyses demonstrate that the presence of disordered segments among plant proteins is associated with the rates of genetic recombination of their encoding genes. Altogether, these findings suggest that high recombination rates, as well as chromosomal rearrangements, could induce disordered segments in proteins during evolution.

Canopy bidirectional reflectance calculation based on Adding method and SAIL formalism: AddingS / AddingSD

NARCIS (Netherlands)

Kallel, A.; Verhoef, W.; Hegarat-Mascle, Le S.; Ottle, C.; Hubert-Moy, L.

2008-01-01

The SAIL model (proposed by Verhoef) is largely used in the remote sensing community to calculate the canopy Bidirectional Reflectance Distribution Function. The simulation results appear acceptable compared to observations especially for not very dense planophile vegetation. However, for

Stability of dynamical systems

CERN Document Server

Liao, Xiaoxin; Yu, P 0

2007-01-01

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

Intrinsic and extrinsic motivation for smoking cessation.

Science.gov (United States)

Curry, S; Wagner, E H; Grothaus, L C

1990-06-01

An intrinsic-extrinsic model of motivation for smoking cessation was evaluated with 2 samples (ns = 1.217 and 151) of smokers who requested self-help materials for smoking cessation. Exploratory and confirmatory principal components analysis on a 36-item Reasons for Quitting (RFQ) scale supported the intrinsic-extrinsic motivation distinction. A 4-factor model, with 2 intrinsic dimensions (concerns about health and desire for self-control) and 2 extrinsic dimensions (immediate reinforcement and social influence), was defined by 20 of the 36 RFQ items. The 20-item measure demonstrated moderate to high levels of internal consistency and convergent and discriminant validity. Logistic regression analyses indicated that smokers with higher levels of intrinsic relative to extrinsic motivation were more likely to achieve abstinence from smoking.

Deuterium NMR, induced and intrinsic cholesteric lyomesophases

International Nuclear Information System (INIS)

Alcantara, M.R.

1982-01-01

Induced and intrinsic cholesteric lyotropic mesophases were studied. Induced cholesteric lyomesophases based on potassium laurate (KL) system, with small amounts of cholesterol added, were studied by deuterium NMR and by polarizing microscopy. Order profiles obtained from deuterium NMR of KL perdenderated chains in both induced cholesteric and normal mesophases were compared. The intrinsic cholesteric lyotropic mesophases were based on the amphiphile potassium N-lauroyl serinate (KLNS) in the resolved levo form. The study of the type I intrinsic cholesteric mesophase was made by optical microscopy under polarized light and the type II intrinsic cholesteric lyomesophase was characterized by deuterium NMR. The new texture was explained by the use of the theory of disclinations developed for thermotropic liquid crystals, specially for cholesteric type. (M.J.C.) [pt

A Four-Phase High Voltage Conversion Ratio Bidirectional DC-DC Converter for Battery Applications

Directory of Open Access Journals (Sweden)

Li-Kun Xue

2015-06-01

Full Text Available This study presents a four-phase interleaved high voltage conversion ratio bidirectional DC-DC converter circuit based on coupled inductors and switched capacitors, which can eliminate the defects of conventional high voltage conversion ratio bidirectional DC-DC converters in terms of high-voltage/current stress, less efficiency and low-power limitation. Parallel channels are used to reduce current stress at the low-voltage side and series connected switched capacitors are used to enlarge voltage conversion ratio, reduce voltage stress and achieve auto current sharing. This paper proposes the operation principle, feature analysis and optimization design considerations. On this basis the objectives of high voltage conversion ratio, low voltage/current stress, high power density, high efficiency and high-power applications can be achieved. Some experimental results based on a 500 W prototype converter (24 V to 48 V at low-voltage side, 400 V at high-voltage side are given to verify the theoretical analysis and the effectiveness of the proposed converter.

Intrinsic bioremediation of landfills interim report

International Nuclear Information System (INIS)

Brigmon, R.L.; Fliermans, C.B.

1997-01-01

Intrinsic bioremediation is a risk management option that relies on natural biological and physical processes to contain the spread of contamination from a source. Evidence is presented in this report that intrinsic bioremediation is occurring at the Sanitary Landfill is fundamental to support incorportion into a Corrective Action Plan (CAP)

Intrinsic bioremediation of landfills interim report

Energy Technology Data Exchange (ETDEWEB)

Brigmon, R.L. [Westinghouse Savannah River Company, Aiken, SC (United States); Fliermans, C.B.

1997-07-14

Intrinsic bioremediation is a risk management option that relies on natural biological and physical processes to contain the spread of contamination from a source. Evidence is presented in this report that intrinsic bioremediation is occurring at the Sanitary Landfill is fundamental to support incorportion into a Corrective Action Plan (CAP).

Expressing intrinsic volumes as rotational integrals

DEFF Research Database (Denmark)

Auneau, Jeremy Michel; Jensen, Eva Bjørn Vedel

2010-01-01

A new rotational formula of Crofton type is derived for intrinsic volumes of a compact subset of positive reach. The formula provides a functional defined on the section of X with a j-dimensional linear subspace with rotational average equal to the intrinsic volumes of X. Simplified forms of the ...

Using super-capacitors in combination with Bi-directional DC/DC converters for active load management in residential fuel cell applications

Energy Technology Data Exchange (ETDEWEB)

Cacciato, M.; Giulii Capponi, F. [Rome Univ., ' La Sapienza' , Dept. of Electrical Engineering (Italy)

2004-07-01

Among innovative conversion systems for alternative energy, Fuel Cells (FCs) are ideal in applications as distributed power generation or automotive. The connection of FCs to domestic or industrial loads requires a DC/AC converter also acting as a energy buffer to match the different dynamics of FCs and loads. In the last years, a new type of electrolytic capacitors called Super- Capacitors (SCs), has been designed using double layers technology. Such components are able to store more energy than electrolytic capacitors maintaining the capability to swap it at high power levels. Firstly, different solution used to connect SCs to a FC based conversion system are considered. Then, a comparison of bi-directional DC/DC converters designed to manage SCs energy is performed. Finally, the converter design and a laboratory prototype of the adopted solution are reported. (authors)

Analysis of snow bidirectional reflectance from ARCTAS Spring-2008 Campaign

Directory of Open Access Journals (Sweden)

A. Lyapustin

2010-05-01

Full Text Available The spring 2008 Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS experiment was one of major intensive field campaigns of the International Polar Year aimed at detailed characterization of atmospheric physical and chemical processes in the Arctic region. A part of this campaign was a unique snow bidirectional reflectance experiment on the NASA P-3B aircraft conducted on 7 and 15 April by the Cloud Absorption Radiometer (CAR jointly with airborne Ames Airborne Tracking Sunphotometer (AATS and ground-based Aerosol Robotic Network (AERONET sunphotometers. The CAR data were atmospherically corrected to derive snow bidirectional reflectance at high 1° angular resolution in view zenith and azimuthal angles along with surface albedo. The derived albedo was generally in good agreement with ground albedo measurements collected on 15 April. The CAR snow bidirectional reflectance factor (BRF was used to study the accuracy of analytical Ross-Thick Li-Sparse (RTLS, Modified Rahman-Pinty-Verstraete (MRPV and Asymptotic Analytical Radiative Transfer (AART BRF models. Except for the glint region (azimuthal angles φ<40°, the best fit MRPV and RTLS models fit snow BRF to within ±0.05. The plane-parallel radiative transfer (PPRT solution was also analyzed with the models of spheres, spheroids, randomly oriented fractal crystals, and with a synthetic phase function. The latter merged the model of spheroids for the forward scattering angles with the fractal model in the backscattering direction. The PPRT solution with synthetic phase function provided the best fit to measured BRF in the full range of angles. Regardless of the snow grain shape, the PPRT model significantly over-/underestimated snow BRF in the glint/backscattering regions, respectively, which agrees with other studies. To improve agreement with experiment, we introduced a model of macroscopic snow surface roughness by averaging the PPRT solution over the

Analysis of Snow Bidirectional Reflectance from ARCTAS Spring-2008 Campaign

Science.gov (United States)

Lyapustin, A.; Gatebe, C. K.; Redemann, J.; Kahn, R.; Brandt, R.; Russell, P.; King, M. D.; Pedersen, C. A.; Gerland, S.; Poudyal, R.;

Design and implementation of a bidirectional current-controlled voltage-regulated DC-DC switched-mode converter

CSIR Research Space (South Africa)

Coetzer, A

2016-01-01

Full Text Available The design and implementation of a bidirectional current-controlled voltage-regulated DC-DC converter is presented. The converter is required to connect a battery of electrochemical cells (the battery) to an asynchronous motor-drive unit via a...

The Bidirectional Relationship between Diabetes and Depression: A Literature Review.

Science.gov (United States)

Alzoubi, Abdallah; Abunaser, Rnad; Khassawneh, Adi; Alfaqih, Mahmoud; Khasawneh, Aws; Abdo, Nour

2018-05-01

Diabetes is a major public health problem worldwide. Depression is a serious mental condition that decreases mental and physical functioning and reduces the quality of life. Several lines of evidence suggest a bidirectional relationship between diabetes and depression: diabetes patients are twice as likely to experience depression than nondiabetic individuals. In contrast, depression increases the risk of diabetes and interferes with its daily self-management. Diabetes patients with depression have poor glycemic control, reduced quality of life, and an increased risk of diabetes complications, consequently having an increased mortality rate. Conflicting evidence exists on the potential role of factors that may account for or modulate the relationship between diabetes and depression. Therefore, this review aims to highlight the most notable body of literature that dissects the various facets of the bidirectional relationship between diabetes and depression. A focused discussion of the proposed mechanisms underlying this relationship is also provided. We systematically reviewed the relevant literature in the PubMed database, using the keywords "Diabetes AND Depression". After exclusion of duplicate and irrelevant material, literature eligible for inclusion in this review was based on meta-analysis studies, clinical trials with large sample sizes (n≥1,000), randomized clinical trials, and comprehensive national and cross-country clinical studies. The evidence we present in this review supports the pressing need for long, outcome-oriented, randomized clinical trials to determine whether the identification and treatment of patients with these comorbid conditions will improve their medical outcomes and quality of life.

Identifying the neural substrates of intrinsic motivation during task performance.

Science.gov (United States)

Lee, Woogul; Reeve, Johnmarshall

2017-10-01

Intrinsic motivation is the inherent tendency to seek out novelty and challenge, to explore and investigate, and to stretch and extend one's capacities. When people imagine performing intrinsically motivating tasks, they show heightened anterior insular cortex (AIC) activity. To fully explain the neural system of intrinsic motivation, however, requires assessing neural activity while people actually perform intrinsically motivating tasks (i.e., while answering curiosity-inducing questions or solving competence-enabling anagrams). Using event-related functional magnetic resonance imaging, we found that the neural system of intrinsic motivation involves not only AIC activity, but also striatum activity and, further, AIC-striatum functional interactions. These findings suggest that subjective feelings of intrinsic satisfaction (associated with AIC activations), reward processing (associated with striatum activations), and their interactions underlie the actual experience of intrinsic motivation. These neural findings are consistent with the conceptualization of intrinsic motivation as the pursuit and satisfaction of subjective feelings (interest and enjoyment) as intrinsic rewards.

Refining the intrinsic chimera flap: a review.

Science.gov (United States)

Agarwal, Jayant P; Agarwal, Shailesh; Adler, Neta; Gottlieb, Lawrence J

2009-10-01

Reconstruction of complex tissue deficiencies in which each missing component is in a different spatial relationship to each other can be particularly challenging, especially in patients with limited recipient vessels. The chimera flap design is uniquely suited to reconstruct these deformities. Chimera flaps have been previously defined in many ways with 2 main categories: prefabricated or intrinsic. Herein we attempt to clarify the definition of a true intrinsic chimeric flap and provide examples of how these constructs provide a method for reconstruction of complex defects. The versatility of the intrinsic chimera flap and its procurement from 7 different vascular systems is described. A clarification of the definition of a true intrinsic chimera flap is described. In addition, construction of flaps from the lateral femoral circumflex, deep circumflex iliac, inferior gluteal, peroneal, subscapular, thoracodorsal, and radial arterial systems is described to showcase the versatility of these chimera flaps. A true intrinsic chimera flap must consist of more than a single tissue type. Each of the tissue components receives its blood flow from separate vascular branches or perforators that are connected to a single vascular source. These vascular branches must be of appropriate length to allow for insetting with 3-dimensional spatial freedom. There are a multitude of sites from which true intrinsic chimera flaps may be harvested.

Stability Switches, Hopf Bifurcations, and Spatio-temporal Patterns in a Delayed Neural Model with Bidirectional Coupling

Science.gov (United States)

Song, Yongli; Zhang, Tonghua; Tadé, Moses O.

2009-12-01

The dynamical behavior of a delayed neural network with bi-directional coupling is investigated by taking the delay as the bifurcating parameter. Some parameter regions are given for conditional/absolute stability and Hopf bifurcations by using the theory of functional differential equations. As the propagation time delay in the coupling varies, stability switches for the trivial solution are found. Conditions ensuring the stability and direction of the Hopf bifurcation are determined by applying the normal form theory and the center manifold theorem. We also discuss the spatio-temporal patterns of bifurcating periodic oscillations by using the symmetric bifurcation theory of delay differential equations combined with representation theory of Lie groups. In particular, we obtain that the spatio-temporal patterns of bifurcating periodic oscillations will alternate according to the change of the propagation time delay in the coupling, i.e., different ranges of delays correspond to different patterns of neural activities. Numerical simulations are given to illustrate the obtained results and show the existence of bursts in some interval of the time for large enough delay.

Intrinsically Disordered Side of the Zika Virus Proteome

Directory of Open Access Journals (Sweden)

Rajanish Giri

2016-11-01

Full Text Available Over the last few decades, concepts of protein intrinsic disorder have been implicated in different biological processes. Recent studies have suggested that intrinsically disordered proteins (IDPs provide structural plasticity and functional diversity to viral proteins that are involved in rapid replication and immune evasion in host cells. In case of Zika virus, the roles of protein intrinsic disorder in mechanisms of pathogenesis are not completely understood. In this study, we have analyzed the prevalence of intrinsic disorder in Zika virus proteome (strain MR 766. Our analyses revealed that Zika virus polyprotein is enriched with intrinsically disordered protein regions (IDPRs and this finding is consistent with previous reports on the involvement of IDPs in shell formation and virulence of the Flaviviridae family. We found abundant IDPRs in Capsid, NS2B, NS3, NS4A, and NS5 proteins that are involved in mature particle formation and replication. In our view, the intrinsic disorder-focused analysis of ZIKV proteins could be important for the development of new disorder-based drugs.

Bidirectional Four-Wave Mixing in Semiconductor Optical Amplifiers: Theory and Experiment

DEFF Research Database (Denmark)

Bischoff, Svend; Buxens, Alvaro A.; Poulsen, Henrik Nørskov

1999-01-01

) is theoretically predicted for bit rates of 10, 20 and 40 Gb/s and is shown to be in agreement with measurements performed at 10 and 20 Gb/s. Measurements of the clear/drop functionality using the bidirectional technique show excellent performance for a 4 x 10 Gb/s signal and is again in good agreement...... with simulations. The clear/drop functionality is also simulated for 4 x 20 Gb/s and 4 x 40 Gb/s signals....

An assay for serum vitamin-B12 and for intrinsic factor antibody type I by means of hog intrinsic factor

International Nuclear Information System (INIS)

Hudak, J.; Berger, Z.; Varga, L.

1980-01-01

A new radioassay method was elaborated for the determination of the plasma level of vitamin B 12 and of the intrinsic factor antibody type I. The assay applies vitamin-B 12 labelled with 58 Co, but replaces human intrinsic factor by hog intrinsic factor. 124 cases were investigated by both the original and this modified method, and the results were in very good agreement. (L.E.)

Discrete-time bidirectional associative memory neural networks with variable delays

International Nuclear Information System (INIS)

Liang Jinling; Cao Jinde; Ho, Daniel W.C.

2005-01-01

Based on the linear matrix inequality (LMI), some sufficient conditions are presented in this Letter for the existence, uniqueness and global exponential stability of the equilibrium point of discrete-time bidirectional associative memory (BAM) neural networks with variable delays. Some of the stability criteria obtained in this Letter are delay-dependent, and some of them are delay-independent, they are less conservative than the ones reported so far in the literature. Furthermore, the results provide one more set of easily verified criteria for determining the exponential stability of discrete-time BAM neural networks

Discrete-time bidirectional associative memory neural networks with variable delays

Science.gov (United States)

Liang, variable delays [rapid communication] J.; Cao, J.; Ho, D. W. C.

2005-02-01

Based on the linear matrix inequality (LMI), some sufficient conditions are presented in this Letter for the existence, uniqueness and global exponential stability of the equilibrium point of discrete-time bidirectional associative memory (BAM) neural networks with variable delays. Some of the stability criteria obtained in this Letter are delay-dependent, and some of them are delay-independent, they are less conservative than the ones reported so far in the literature. Furthermore, the results provide one more set of easily verified criteria for determining the exponential stability of discrete-time BAM neural networks.

Comparison of the bidirectional reflectance distribution function of various surfaces

International Nuclear Information System (INIS)

Fernandez, R.; Seasholtz, R.G.; Oberle, L.G.; Kadambi, J.R.

1989-01-01

This paper describes the development and use of a system to measure the bidirectional reflectance distribution function (BRDF) of various surfaces. The BRDF measurements are to be used in the analysis and design of optical measurement systems such as laser anemometers. An Ar-ion laser (514 nm) was the light source. Preliminary results are presented for eight samples: two glossy black paints, two flat black paints, black glass, sand-blasted Al, unworked Al, and a white paint. A BaSO4 white reflectance standard was used as the reference sample throughout the tests. 8 refs

Flavor Structure of Intrinsic Nucleon Sea

International Nuclear Information System (INIS)

Peng, Jen-Chieh; Chang, Wen-Chen; Cheng, Hai-Yang; Liu, Keh-Fei

2015-01-01

The concept of intrinsic charm suggested by Brodsky et al. is extended to lighter quarks. Extraction of the intrinsic ū, d-macron, and s-macron seas is obtained from an analysis of the d-macron − ū, s + s-macron, and ū + d-macron − s −s-macron distributions. The connection between the intrinsic/extrinsic seas and the connected/disconnected seas in lattice QCD is also examined. It is shown that the connected and disconnected components for the ū(x) + d-macron(x) sea can be separated. The striking x-dependence of the [s(x) + s-macron(x)]/[ū(x) + d-macron(x)] ratio is interpreted as an interplay between the connected and disconnected seas. (author)

Intrinsically Disordered Proteins in a Physics-Based World

Directory of Open Access Journals (Sweden)

Jianhan Chen

2010-12-01

Full Text Available Intrinsically disordered proteins (IDPs are a newly recognized class of functional proteins that rely on a lack of stable structure for function. They are highly prevalent in biology, play fundamental roles, and are extensively involved in human diseases. For signaling and regulation, IDPs often fold into stable structures upon binding to specific targets. The mechanisms of these coupled binding and folding processes are of significant importance because they underlie the organization of regulatory networks that dictate various aspects of cellular decision-making. This review first discusses the challenge in detailed experimental characterization of these heterogeneous and dynamics proteins and the unique and exciting opportunity for physics-based modeling to make crucial contributions, and then summarizes key lessons from recent de novo simulations of the structure and interactions of several regulatory IDPs.

Hamiltonian reductions in plasma physics about intrinsic gyrokinetic

International Nuclear Information System (INIS)

Guillebon de Resnes, L. de

2013-01-01

Gyrokinetic is a key model for plasma micro-turbulence, commonly used for fusion plasmas or small-scale astrophysical turbulence, for instance. The model still suffers from several issues, which could imply to reconsider the equations. This thesis dissertation clarifies three of them. First, one of the coordinates caused questions, both from a physical and from a mathematical point of view; a suitable constrained coordinate is introduced, which removes the issues from the theory and explains the intrinsic structures underlying the questions. Second, the perturbative coordinate transformation for gyrokinetic was computed only at lowest orders; explicit induction relations are obtained to go arbitrary order in the expansion. Third, the introduction of the coupling between the plasma and the electromagnetic field was not completely satisfactory; using the Hamiltonian structure of the dynamics, it is implemented in a more appropriate way, with strong consequences on the gyrokinetic equations, especially about their Hamiltonian structure. In order to address these three main points, several other results are obtained, for instance about the origin of the guiding-center adiabatic invariant, about a very efficient minimal guiding center transformation, or about an intermediate Hamiltonian model between Vlasov-Maxwell and gyrokinetic, where the characteristics include both the slow guiding-center dynamics and the fast gyro-angle dynamics. In addition, various reduction methods are used, introduced or developed, e.g. a Lie-transform of the equations of motion, a lifting method to transfer particle reductions to the corresponding Hamiltonian field dynamics, or a truncation method related both to Dirac's theory of constraints and to a projection onto a Lie-subalgebra. Besides gyrokinetic, this is useful to clarify other Hamiltonian reductions in plasma physics, for instance for incompressible or electrostatic dynamics, for magnetohydrodynamics, or for fluid closures including

Bidirectional regulation of bakuchiol, an estrogenic-like compound, on catecholamine secretion

International Nuclear Information System (INIS)

Mao, Haoping; Wang, Hong; Ma, Shangwei; Xu, Yantong; Zhang, Han; Wang, Yuefei; Niu, Zichang; Fan, Guanwei; Zhu, Yan; Gao, Xiu Mei

2014-01-01

Excess or deficiency of catecholamine (CA) secretion was related with several diseases. Recently, estrogen and phytoestrogens were reported to regulate the activity of CA system. Bakuchiol is a phytoestrogen isolated from the seeds of Psoralea corylifolia L. (Leguminosae) which has been used in Traditional Chinese medicine as a tonic or aphrodisiac. In the present study, bovine adrenal medullary cells were employed to investigate the effects and mechanisms of bakuchiol on the regulation of CA secretion. Further, its anti-depressant like and anti-stress effects were evaluated by using behavioral despair and chronic immobilization stress models. Our results indicated that bakuchiol showed bidirectional regulation on CA secretion. It stimulated basal CA secretion in a concentration dependent manner (p + (p + induced CA secretion was related with reduction of intracellular calcium rise. In vivo experiments, we found that bakuchiol significantly reduced immobilization time in behavioral despair mouse (p < 0.05 or 0.01), and plasma epinephrine (E) and norepinephrine (NE) levels in chronic immobilization stress (p < 0.05). Overall, these results present a bidirectional regulation of bakuchiol on CA secretion which indicated that bakuchiol may exert anti-stress and the potential anti-depressant-like effects. - Highlights: • Bakuchiol stimulated basal catecholamine secretion. • Bakuchiol inhibited various secretagogues induced catecholamine secretion. • Bakuchiol may have anti-stress and the potential anti-depression-like effects

Dynamics in international market segmentation of new product growth

NARCIS (Netherlands)

Lemmens, A.; Croux, C.; Stremersch, S.

2012-01-01

Prior international segmentation studies have been static in that they have identified segments that remain stable over time. This paper shows that country segments in new product growth are intrinsically dynamic. We propose a semiparametric hidden Markov model to dynamically segment countries based

Deep learning the dynamic appearance and shape of facial action units

OpenAIRE

Jaiswal, Shashank; Valstar, Michel F.

2016-01-01

Spontaneous facial expression recognition under uncontrolled conditions is a hard task. It depends on multiple factors including shape, appearance and dynamics of the facial features, all of which are adversely affected by environmental noise and low intensity signals typical of such conditions. In this work, we present a novel approach to Facial Action Unit detection using a combination of Convolutional and Bi-directional Long Short-Term Memory Neural Networks (CNN-BLSTM), which jointly lear...

Intrinsic activity in the fly brain gates visual information during behavioral choices.

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Shiming Tang

2010-12-01

Full Text Available The small insect brain is often described as an input/output system that executes reflex-like behaviors. It can also initiate neural activity and behaviors intrinsically, seen as spontaneous behaviors, different arousal states and sleep. However, less is known about how intrinsic activity in neural circuits affects sensory information processing in the insect brain and variability in behavior. Here, by simultaneously monitoring Drosophila's behavioral choices and brain activity in a flight simulator system, we identify intrinsic activity that is associated with the act of selecting between visual stimuli. We recorded neural output (multiunit action potentials and local field potentials in the left and right optic lobes of a tethered flying Drosophila, while its attempts to follow visual motion (yaw torque were measured by a torque meter. We show that when facing competing motion stimuli on its left and right, Drosophila typically generate large torque responses that flip from side to side. The delayed onset (0.1-1 s and spontaneous switch-like dynamics of these responses, and the fact that the flies sometimes oppose the stimuli by flying straight, make this behavior different from the classic steering reflexes. Drosophila, thus, seem to choose one stimulus at a time and attempt to rotate toward its direction. With this behavior, the neural output of the optic lobes alternates; being augmented on the side chosen for body rotation and suppressed on the opposite side, even though the visual input to the fly eyes stays the same. Thus, the flow of information from the fly eyes is gated intrinsically. Such modulation can be noise-induced or intentional; with one possibility being that the fly brain highlights chosen information while ignoring the irrelevant, similar to what we know to occur in higher animals.

Intrinsic neuromodulation: altering neuronal circuits from within.

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Katz, P S; Frost, W N

1996-02-01

There are two sources of neuromodulation for neuronal circuits: extrinsic inputs and intrinsic components of the circuits themselves. Extrinsic neuromodulation is known to be pervasive in nervous systems, but intrinsic neuromodulation is less recognized, despite the fact that it has now been demonstrated in sensory and neuromuscular circuits and in central pattern generators. By its nature, intrinsic neuromodulation produces local changes in neuronal computation, whereas extrinsic neuromodulation can cause global changes, often affecting many circuits simultaneously. Studies in a number of systems are defining the different properties of these two forms of neuromodulation.

Single-stage three-phase AC to DC conversion with isolation and Bi-directional power flow

NARCIS (Netherlands)

Vermulst, B.J.D.; Duarte, J.L.; Wijnands, C.G.E.; Lomonova, E.A.

2014-01-01

An approach for three-phase AC to DC conversion is proposed, which consists of a single-stage while offering galvanic isolation, soft-switching, bi-directional power flow and a significant reduction of inductive and capacitive energy storage. Two elements enable this approach, namely a neutral

The existence of generalized synchronisation of three bidirectionally coupled chaotic systems

International Nuclear Information System (INIS)

Ai-Hua, Hu; Zhen-Yuan, Xu; Liu-Xiao, Guo

2010-01-01

The existence of two types of generalized synchronisation is studied. The model considered here includes three bidirectionally coupled chaotic systems, and two of them denote the driving systems, while the rest stands for the response system. Under certain conditions, the existence of generalised synchronisation can be turned to a problem of compression fixed point in the family of Lipschitz functions. In addition, theoretical proofs are proposed to the exponential attractive property of generalised synchronisation manifold. Numerical simulations validate the theory. (general)

Concepts of intrinsic safety

International Nuclear Information System (INIS)

Anon.

1985-01-01

A newly introduced Japanese reactor concept, ISER (Intrinsically Safe and Economical Reactor), is intended to be a reference intrinsically safe light water reactor. ISER is designed similarly to PIUS but with greater economy in mind such that any utility in any country can choose it for its power system. Social assimilation and acceptability in the Asia Pacific Region including the United States are the keys to the ISER with the hope of dramatic reductions of social costs due to safeguards, reliability, financiability, and infrastructure building, particularly in the third world, as well as reactor safety itself. In this respect and others, the ISER proposal is different from other vendor-proposed reactor concepts and is unique

Longitudinal Relations among Parenting, Best Friends, and Early Adolescent Problem Behavior: Testing Bidirectional Effects

Science.gov (United States)

Reitz, Ellen; Dekovic, Maja; Meijer, Anne Marie; Engels, Rutger C. M. E.

2006-01-01

In this longitudinal study, the bidirectional relations between parenting and friends' deviance, on one hand, and early adolescent externalizing and internalizing problem behavior, on the other hand, are examined. Of the 650 adolescents (13- to 14-year-olds) who filled out the Youth Self-Report and questionnaires about their parents at two times…

Bidirectional Interference between Speech and Nonspeech Tasks in Younger, Middle-Aged, and Older Adults

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Bailey, Dallin J.; Dromey, Christopher

2015-01-01

Purpose: The purpose of this study was to examine divided attention over a large age range by looking at the effects of 3 nonspeech tasks on concurrent speech motor performance. The nonspeech tasks were designed to facilitate measurement of bidirectional interference, allowing examination of their sensitivity to speech activity. A cross-sectional…

Size-Dependent Axonal Bouton Dynamics following Visual Deprivation In Vivo

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Rosanna P. Sammons

2018-01-01

Full Text Available Persistent synapses are thought to underpin the storage of sensory experience, yet little is known about their structural plasticity in vivo. We investigated how persistent presynaptic structures respond to the loss of primary sensory input. Using in vivo two-photon (2P imaging, we measured fluctuations in the size of excitatory axonal boutons in L2/3 of adult mouse visual cortex after monocular enucleation. The average size of boutons did not change after deprivation, but the range of bouton sizes was reduced. Large boutons decreased, and small boutons increased. Reduced bouton variance was accompanied by a reduced range of correlated calcium-mediated neural activity in L2/3 of awake animals. Network simulations predicted that size-dependent plasticity may promote conditions of greater bidirectional plasticity. These predictions were supported by electrophysiological measures of short- and long-term plasticity. We propose size-dependent dynamics facilitate cortical reorganization by maximizing the potential for bidirectional plasticity.

Elements of the Competitive Situation That Affect Intrinsic Motivation.

Science.gov (United States)

Reeve, Johnmarshall; Deci, Edward L.

1996-01-01

Explores the effects of three elements of the competitive situation (competitive set, competitive outcome, and interpersonal context) on intrinsic motivation in a sample of college students (n=100). Competitive outcome and interpersonal context affected intrinsic motivation: winning increased intrinsic motivation, while pressured interpersonal…

Bidirectional interplay of HSF1 degradation and UPR activation promotes tau hyperphosphorylation.

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Eunhee Kim

2017-07-01

Full Text Available The unfolded protein response (UPR in the endoplasmic reticulum (ER and the cytoplasmic heat stress response are two major stress response systems necessary for maintaining proteostasis for cellular health. Failure of either of these systems, such as in sustained UPR activation or in insufficient heat shock response activation, can lead to the development of neurodegeneration. Alleviation of ER stress and enhancement of heat shock response through heat shock factor 1 (HSF1 activation have previously been considered as attractive potential therapeutic targets for Alzheimer's disease (AD-a prevalent and devastating tauopathy. Understanding the interplay of the two aforementioned systems and their cooperative role in AD remain elusive. Here we report studies in human brain and tau pathogenic mouse models (rTg4510, PS19, and rTg21221, identifying HSF1 degradation and UPR activation as precursors of aberrant tau pathogenesis. We demonstrate that chemical ER stress inducers caused autophagy-lysosomal HSF1 degradation, resulting in tau hyperphosphorylation in rat primary neurons. In addition, permanent HSF1 loss reversely causes chronic UPR activation, leading to aberrant tau phosphorylation and aggregation in the hippocampus of aged HSF1 heterozygous knock-out mice. The deleterious interplay of UPR activation and HSF1 loss is exacerbated in N2a cells stably overexpressing a pro-aggregation mutant TauRD ΔK280 (N2a-TauRD ΔK280. We provide evidence of how these two stress response systems are intrinsically interweaved by showing that the gene encoding C/EBP-homologous protein (CHOP activation in the UPR apoptotic pathway facilitates HSF1 degradation, which likely further contributes to prolonged UPR via ER chaperone HSP70 a5 (BiP/GRP78 suppression. Upregulating HSF1 relieves the tau toxicity in N2a-TauRD ΔK280 by reducing CHOP and increasing HSP70 a5 (BiP/GRP78. Our work reveals how the bidirectional crosstalk between the two stress response systems

Classical emergence of intrinsic spin-orbit interaction of light at the nanoscale

Science.gov (United States)

Vázquez-Lozano, J. Enrique; Martínez, Alejandro

2018-03-01

Traditionally, in macroscopic geometrical optics intrinsic polarization and spatial degrees of freedom of light can be treated independently. However, at the subwavelength scale these properties appear to be coupled together, giving rise to the spin-orbit interaction (SOI) of light. In this work we address theoretically the classical emergence of the optical SOI at the nanoscale. By means of a full-vector analysis involving spherical vector waves we show that the spin-orbit factorizability condition, accounting for the mutual influence between the amplitude (spin) and phase (orbit), is fulfilled only in the far-field limit. On the other side, in the near-field region, an additional relative phase introduces an extra term that hinders the factorization and reveals an intricate dynamical behavior according to the SOI regime. As a result, we find a suitable theoretical framework able to capture analytically the main features of intrinsic SOI of light. Besides allowing for a better understanding into the mechanism leading to its classical emergence at the nanoscale, our approach may be useful to design experimental setups that enhance the response of SOI-based effects.

Bidirectional asymmetry in the neurovisceral communication for the cardiovascular control: New insights

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Prieto I

2017-07-01

Full Text Available The cardiovascular control involves a bidirectional functional connection between the brain and heart. We hypothesize that this connection could be extended to other organs using endocrine and autonomic nervous systems (ANS as communication pathways. This implies a neuroendocrine interaction controlling particularly the cardiovascular function where the enzymatic cascade of the renin-angiotensin system (RAS plays an essential role. It acts not only through its classic endocrine connection but also the ANS. In addition, the brain is functionally, anatomically, and neurochemically asymmetric. Moreover, this asymmetry goes even beyond the brain and it includes both sides of the peripheral nervous and neuroendocrine systems. We revised the available information and analyze the asymmetrical neuroendocrine bidirectional interaction for the cardiovascular control. Negative and positive correlations involving the RAS have been observed between brain, heart, kidney, gut, and plasma in physiologic and pathologic conditions. The central role of the peptides and enzymes of the RAS within this neurovisceral communication, as well as the importance of the asymmetrical distribution of the various RAS components in the pathologies involving this connection, are particularly discussed. In conclusion, there are numerous evidences supporting the existence of a neurovisceral connection with multiorgan involvement that controls, among others, the cardiovascular function. This connection is asymmetrically organized.

Moral judgment modulation by disgust is bi-directionally moderated by individual sensitivity

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How Hwee eOng

2014-03-01

Full Text Available Modern theories of moral judgment predict that both conscious reasoning and unconscious emotional influences affect the way people decide about right and wrong. In a series of experiments, we tested the effect of subliminal and conscious priming of disgust facial expressions on moral dilemmas. Trolley-car-type scenarios were used, with subjects rating how acceptable they found the utilitarian course of action to be. On average, subliminal priming of disgust facial expressions resulted in higher rates of utilitarian judgments compared to neutral facial expressions. Further, in replication, we found that individual change in moral acceptability ratings due to disgust priming was modulated by individual sensitivity to disgust, revealing a bi-directional function. Our second replication extended this result to show that the function held for both subliminally and consciously presented stimuli. Combined across these experiments, we show a reliable bi-directional function, with presentation of disgust expression primes to individuals with higher disgust sensitivity resulting in more utilitarian judgments (i.e., number-based and presentations to individuals with lower sensitivity resulting in more deontological judgments (i.e., rules-based. Our results may reconcile previous conflicting reports of disgust modulation of moral judgment by modeling how individual sensitivity to disgust determines the direction and degree of this effect.

Moral judgment modulation by disgust is bi-directionally moderated by individual sensitivity

Science.gov (United States)

Ong, How Hwee; Mullette-Gillman, O’Dhaniel A.; Kwok, Kenneth; Lim, Julian

2014-01-01

Modern theories of moral judgment predict that both conscious reasoning and unconscious emotional influences affect the way people decide about right and wrong. In a series of experiments, we tested the effect of subliminal and conscious priming of disgust facial expressions on moral dilemmas. “Trolley-car”-type scenarios were used, with subjects rating how acceptable they found the utilitarian course of action to be. On average, subliminal priming of disgust facial expressions resulted in higher rates of utilitarian judgments compared to neutral facial expressions. Further, in replication, we found that individual change in moral acceptability ratings due to disgust priming was modulated by individual sensitivity to disgust, revealing a bi-directional function. Our second replication extended this result to show that the function held for both subliminally and consciously presented stimuli. Combined across these experiments, we show a reliable bi-directional function, with presentation of disgust expression primes to individuals with higher disgust sensitivity resulting in more utilitarian judgments (i.e., number-based) and presentations to individuals with lower sensitivity resulting in more deontological judgments (i.e., rules-based). Our results may reconcile previous conflicting reports of disgust modulation of moral judgment by modeling how individual sensitivity to disgust determines the direction and degree of this effect. PMID:24639665

Intrinsic interactive reinforcement learning - Using error-related potentials for real world human-robot interaction.

Science.gov (United States)

Kim, Su Kyoung; Kirchner, Elsa Andrea; Stefes, Arne; Kirchner, Frank

2017-12-14

Reinforcement learning (RL) enables robots to learn its optimal behavioral strategy in dynamic environments based on feedback. Explicit human feedback during robot RL is advantageous, since an explicit reward function can be easily adapted. However, it is very demanding and tiresome for a human to continuously and explicitly generate feedback. Therefore, the development of implicit approaches is of high relevance. In this paper, we used an error-related potential (ErrP), an event-related activity in the human electroencephalogram (EEG), as an intrinsically generated implicit feedback (rewards) for RL. Initially we validated our approach with seven subjects in a simulated robot learning scenario. ErrPs were detected online in single trial with a balanced accuracy (bACC) of 91%, which was sufficient to learn to recognize gestures and the correct mapping between human gestures and robot actions in parallel. Finally, we validated our approach in a real robot scenario, in which seven subjects freely chose gestures and the real robot correctly learned the mapping between gestures and actions (ErrP detection (90% bACC)). In this paper, we demonstrated that intrinsically generated EEG-based human feedback in RL can successfully be used to implicitly improve gesture-based robot control during human-robot interaction. We call our approach intrinsic interactive RL.

A radioisotope dilution assay for unlabelled vitamin B12-intrinsic factor complex employing the binding intrinsic factor antibody: probable evidence for two types of binding antibody

International Nuclear Information System (INIS)

Jacob, E.; O'Brien, H.A.W.; Mollin, D.L.

1977-01-01

A new radioisotope dilution assay for vitamin B 12 -intrinsic factor complex is described. The method is based on the use of the binding type intrinsic antibody (the binding reagent), which when combined with the intrinsic factor-vitamin B 12 complex (labelled ligand), is quantitatively adsorbed onto zirconium phosphate gel pH 6.25. The new assay has been shown to provide a measure of intrinsic factor comparable with other intrinsic factor assays, but it has the important advantage of being able to measure the unlabelled vitamin B 12 -intrinsic factor complex (unlabelled ligand), and will, therefore, be valuable in the study of physiological events in the gastrointestinal tract. During the study, it was found that there is some evidence for at least two types of binding intrinsic factor antibody: One which combines preferentially with the intrinsic factor-vitamin B 12 complex and one which combines equally well with this complex or with free intrinsic factor. (author)

Intrinsically disordered regions may lower the hydration free energy in proteins: a case study of nudix hydrolase in the bacterium Deinococcus radiodurans.

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Omar Awile

Full Text Available The proteome of the radiation- and desiccation-resistant bacterium D. radiodurans features a group of proteins that contain significant intrinsically disordered regions that are not present in non-extremophile homologues. Interestingly, this group includes a number of housekeeping and repair proteins such as DNA polymerase III, nudix hydrolase and rotamase. Here, we focus on a member of the nudix hydrolase family from D. radiodurans possessing low-complexity N- and C-terminal tails, which exhibit sequence signatures of intrinsic disorder and have unknown function. The enzyme catalyzes the hydrolysis of oxidatively damaged and mutagenic nucleotides, and it is thought to play an important role in D. radiodurans during the recovery phase after exposure to ionizing radiation or desiccation. We use molecular dynamics simulations to study the dynamics of the protein, and study its hydration free energy using the GB/SA formalism. We show that the presence of disordered tails significantly decreases the hydration free energy of the whole protein. We hypothesize that the tails increase the chances of the protein to be located in the remaining water patches in the desiccated cell, where it is protected from the desiccation effects and can function normally. We extrapolate this to other intrinsically disordered regions in proteins, and propose a novel function for them: intrinsically disordered regions increase the "surface-properties" of the folded domains they are attached to, making them on the whole more hydrophilic and potentially influencing, in this way, their localization and cellular activity.

Modelling the role of intrinsic electric fields in microtubules as an additional control mechanism of bi-directional intracellular transport.

Science.gov (United States)

Sataric, M V; Budinski-Petkovic, L; Loncarevic, I; Tuszynski, J A

2008-01-01

Active transport is essential for cellular function, while impaired transport has been linked to diseases such as neuronal degeneration. Much long distance transport in cells uses opposite polarity molecular motors of the kinesin and dynein families to move cargos along microtubules. It is clear that many types of cargo are moved by both sets of motors, and frequently in a reverse direction. The general question of how the direction of transport is regulated is still open. The mechanism of the cell's differential control of diverse cargos within the same cytoplasmic background is still unclear as is the answer to the question how endosomes and mitochondria move to different locations within the same cell. To answer these questions we postulate the existence of a local signaling mechanism used by the cell to specifically control different cargos. In particular, we propose an additional physical mechanism that works through the use of constant and alternating intrinsic (endogenous) electric fields as a means of controlling the speed and direction of microtubule-based transport. A specific model is proposed and analyzed in this paper. The model involves the rotational degrees of freedom of the C-termini of tubulin, their interactions and the coupling between elastic and dielectric degrees of freedom. Viscosity of the solution is also included and the resultant equation of motion is found as a nonlinear elliptic equation with dissipation. A particular analytical solution of this equation is obtained in the form of a kink whose properties are analyzed. It is concluded that this solution can be modulated by the presence of electric fields and hence may correspond to the observed behavior of motor protein transport along microtubules.